diff --git a/AUTHORS b/AUTHORS index 48ce71f4cc6..95d3158d204 100644 --- a/AUTHORS +++ b/AUTHORS @@ -41,7 +41,7 @@ Aeneas Rekkas (arekkas) Afanasev Stanislav Agis Anastasopoulos Agniva De Sarker -Ahmed Wahed +Ahmed W. Mones Ahmet Soormally Ahmy Yulrizka Aiden Scandella diff --git a/CONTRIBUTORS b/CONTRIBUTORS index 6c7262adb1f..1984d44c537 100644 --- a/CONTRIBUTORS +++ b/CONTRIBUTORS @@ -33,6 +33,7 @@ Aaron Jacobs Aaron Jensen Aaron Kemp Aaron Patterson +Aaron Sheah Aaron Stein Aaron Torres Aaron Zinman @@ -47,6 +48,7 @@ Adam Harvey Adam Kisala Adam Langley Adam Medzinski +Adam Mitha Adam Shannon Adam Shelton Adam Sindelar @@ -54,6 +56,8 @@ Adam Thomason Adam Williams Adam Woodbeck Adarsh Ravichandran +Adel Rodríguez +Adin Scannell Aditya Harindar Aditya Mukerjee Adrian Hesketh @@ -67,7 +71,8 @@ Aeneas Rekkas (arekkas) Afanasev Stanislav Agis Anastasopoulos Agniva De Sarker -Ahmed Wahed +Ahmed W. Mones +Ahmet Aktürk Ahmet Alp Balkan Ahmet Soormally Ahmy Yulrizka @@ -92,11 +97,13 @@ Alberto Bertogli Alberto Donizetti Alberto García Hierro Alec Benzer +Alejandro García Montoro Aleksa Sarai Aleksandar Dezelin Aleksandr Lukinykh Aleksandr Razumov Alekseev Artem +Aleksei Tirman Alessandro Arzilli Alessandro Baffa Alex A Skinner @@ -165,6 +172,7 @@ Ali Rizvi-Santiago Aliaksandr Valialkin Alice Merrick Alif Rachmawadi +Allan Guwatudde Allan Simon Allen Li Alok Menghrajani @@ -172,6 +180,7 @@ Alwin Doss Aman Gupta Amarjeet Anand Amir Mohammad Saied +Amit Kumar Amr Mohammed Amrut Joshi An Long @@ -185,6 +194,7 @@ André Carvalho André Martins Andre Nathan Andrea Nodari +Andrea Simonini Andrea Spadaccini Andreas Auernhammer Andreas Jellinghaus @@ -244,6 +254,7 @@ Andy Pan Andy Walker Andy Wang Andy Williams +Andy Zhao Andzej Maciusovic Anfernee Yongkun Gui Angelo Bulfone @@ -269,6 +280,7 @@ Anton Kuklin Antonin Amand Antonio Antelo Antonio Bibiano +Antonio Garcia Antonio Huete Jimenez Antonio Murdaca Antonio Troina @@ -292,8 +304,10 @@ Artem Khvastunov Artem Kolin Arthur Fabre Arthur Khashaev +Artur M. Wolff Artyom Pervukhin Arvindh Rajesh Tamilmani +Ashish Bhate Ashish Gandhi Asim Shankar Assel Meher @@ -325,6 +339,7 @@ Baokun Lee Barnaby Keene Bartosz Grzybowski Bartosz Oler +Bassam Ojeil Bastian Ike Ben Burkert Ben Cartwright-Cox @@ -332,6 +347,7 @@ Ben Eitzen Ben Fried Ben Haines Ben Hoyt +Ben Hutchings Ben Kraft Ben Laurie Ben Lubar @@ -430,6 +446,7 @@ Carl Henrik Lunde Carl Jackson Carl Johnson Carl Mastrangelo +Carl Menezes Carl Shapiro Carlisia Campos Carlo Alberto Ferraris @@ -443,6 +460,7 @@ Carlos Iriarte Carlos Souza Carolyn Van Slyck Carrie Bynon +Carson Hoffman Cary Hull Case Nelson Casey Callendrello @@ -462,6 +480,7 @@ Charles Kenney Charles L. Dorian Charles Lee Charles Weill +Charlie Moog Charlotte Brandhorst-Satzkorn Chauncy Cullitan Chen Zhidong @@ -516,6 +535,7 @@ Christopher Nelson Christopher Nielsen Christopher Redden Christopher Swenson +Christopher Thomas <53317512+chrisssthomas@users.noreply.github.com> Christopher Wedgwood Christos Zoulas Christy Perez @@ -541,6 +561,8 @@ Cosmos Nicolaou Costin Chirvasuta Craig Citro Cristian Staretu +Cristo García +cui fliter Cuihtlauac ALVARADO Cuong Manh Le Curtis La Graff @@ -560,6 +582,7 @@ Dan Callahan Dan Harrington Dan Jacques Dan Johnson +Dan McArdle Dan Peterson Dan Pupius Dan Scales @@ -611,6 +634,7 @@ Dave Russell David Anderson David Barnett David Benjamin +David Black David Bond David Brophy David Bürgin <676c7473@gmail.com> @@ -654,6 +678,7 @@ Davor Kapsa Dean Eigenmann <7621705+decanus@users.noreply.github.com> Dean Prichard Deepak Jois +Deepak S Denis Bernard Denis Brandolini Denis Isaev @@ -676,8 +701,10 @@ Dhiru Kholia Dhruvdutt Jadhav Di Xiao Didier Spezia +Diego Medina Diego Siqueira Dieter Plaetinck +Dilyn Corner Dimitri Sokolyuk Dimitri Tcaciuc Dina Garmash @@ -714,6 +741,7 @@ Doug Fawley Douglas Danger Manley Drew Flower Drew Hintz +Drew Richardson Duco van Amstel Duncan Holm Dustin Carlino @@ -735,6 +763,7 @@ Egon Elbre Ehren Kret Eitan Adler Eivind Uggedal +El Mostafa Idrassi Elbert Fliek Eldar Rakhimberdin Elena Grahovac @@ -742,6 +771,7 @@ Eli Bendersky Elias Naur Elliot Morrison-Reed Ellison Leão +Elvina Yakubova Emerson Lin Emil Bektimirov Emil Hessman @@ -767,6 +797,7 @@ Eric Rescorla Eric Roshan-Eisner Eric Rutherford Eric Rykwalder +Eric Wang Erick Tryzelaar Erik Aigner Erik Dubbelboer @@ -778,6 +809,7 @@ Ernest Chiang Erwin Oegema Esko Luontola Ethan Burns +Ethan Hur Ethan Miller Euan Kemp Eugene Formanenko @@ -818,6 +850,7 @@ Felix Cornelius <9767036+fcornelius@users.noreply.github.com> Felix Geisendörfer Felix Kollmann Ferenc Szabo +Fernandez Ludovic Filip Gruszczyński Filip Haglund Filip Stanis @@ -858,6 +891,7 @@ Gabriel Nelle Gabriel Nicolas Avellaneda Gabriel Rosenhouse Gabriel Russell +Gabriel Vasile Gareth Paul Jones Garret Kelly Garrick Evans @@ -891,6 +925,8 @@ Gianguido Sora` Gideon Jan-Wessel Redelinghuys Giles Lean Giovanni Bajo +GitHub User @180909 (70465953) <734461790@qq.com> +GitHub User @6543 (24977596) <6543@obermui.de> GitHub User @aca (50316549) GitHub User @ajnirp (1688456) GitHub User @ajz01 (4744634) @@ -904,10 +940,12 @@ GitHub User @bontequero (2674999) GitHub User @cch123 (384546) GitHub User @chainhelen (7046329) GitHub User @chanxuehong (3416908) +GitHub User @Cluas (10056928) GitHub User @cncal (23520240) GitHub User @DQNEO (188741) GitHub User @Dreamacro (8615343) GitHub User @dupoxy (1143957) +GitHub User @EndlessCheng (7086966) GitHub User @erifan (31343225) GitHub User @esell (9735165) GitHub User @fatedier (7346661) @@ -916,12 +954,15 @@ GitHub User @geedchin (11672310) GitHub User @GrigoriyMikhalkin (3637857) GitHub User @hengwu0 (41297446) <41297446+hengwu0@users.noreply.github.com> GitHub User @hitzhangjie (3725760) +GitHub User @hqpko (13887251) GitHub User @itchyny (375258) GitHub User @jinmiaoluo (39730824) GitHub User @jopbrown (6345470) GitHub User @kazyshr (30496953) GitHub User @kc1212 (1093806) +GitHub User @komisan19 (18901496) GitHub User @Kropekk (13366453) +GitHub User @lhl2617 (33488131) GitHub User @linguohua (3434367) GitHub User @LotusFenn (13775899) GitHub User @ly303550688 (11519839) @@ -936,10 +977,14 @@ GitHub User @OlgaVlPetrova (44112727) GitHub User @pityonline (438222) GitHub User @po3rin (29445112) GitHub User @pokutuna (57545) +GitHub User @povsister (11040951) GitHub User @pytimer (17105586) +GitHub User @qcrao (7698088) GitHub User @ramenjuniti (32011829) GitHub User @saitarunreddy (21041941) +GitHub User @SataQiu (9354727) GitHub User @shogo-ma (9860598) +GitHub User @sivchari (55221074) GitHub User @skanehira (7888591) GitHub User @soolaugust (10558124) GitHub User @surechen (7249331) @@ -947,9 +992,12 @@ GitHub User @tatsumack (4510569) GitHub User @tell-k (26263) GitHub User @tennashi (10219626) GitHub User @uhei (2116845) +GitHub User @uji (49834542) +GitHub User @unbyte (5772358) GitHub User @uropek (39370426) GitHub User @utkarsh-extc (53217283) GitHub User @witchard (4994659) +GitHub User @wolf1996 (5901874) GitHub User @yah01 (12216890) GitHub User @yuanhh (1298735) GitHub User @zikaeroh (48577114) @@ -962,6 +1010,7 @@ Glenn Brown Glenn Lewis Gordon Klaus Gordon Tyler +Grace Han Graham King Graham Miller Grant Griffiths @@ -977,10 +1026,12 @@ Guilherme Caruso Guilherme Garnier Guilherme Goncalves Guilherme Rezende +Guilherme Souza <32180229+gqgs@users.noreply.github.com> Guillaume J. Charmes Guillaume Sottas Günther Noack Guobiao Mei +Guodong Li Guoliang Wang Gustav Paul Gustav Westling @@ -995,6 +1046,7 @@ HAMANO Tsukasa Han-Wen Nienhuys Hang Qian Hanjun Kim +Hanlin He Hanlin Shi Haoran Luo Haosdent Huang @@ -1026,18 +1078,19 @@ Herbie Ong Heschi Kreinick Hidetatsu Yaginuma Hilko Bengen +Himanshu Kishna Srivastava <28himanshu@gmail.com> Hiroaki Nakamura Hiromichi Ema Hironao OTSUBO Hiroshi Ioka Hitoshi Mitake Holden Huang -Songlin Jiang Hong Ruiqi Hongfei Tan Horacio Duran Horst Rutter Hossein Sheikh Attar +Hossein Zolfi Howard Zhang Hsin Tsao Hsin-Ho Yeh @@ -1054,11 +1107,14 @@ Ian Haken Ian Kent Ian Lance Taylor Ian Leue +Ian Mckay Ian Tay +Ian Woolf Ian Zapolsky Ibrahim AshShohail Icarus Sparry Iccha Sethi +Ichinose Shogo Idora Shinatose Ignacio Hagopian Igor Bernstein @@ -1068,6 +1124,7 @@ Igor Vashyst Igor Zhilianin Ikko Ashimine Illya Yalovyy +Ilya Chukov <56119080+Elias506@users.noreply.github.com> Ilya Sinelnikov Ilya Tocar INADA Naoki @@ -1122,6 +1179,7 @@ James Cowgill James Craig Burley James David Chalfant James Eady +James Fennell James Fysh James Gray James Hartig @@ -1178,6 +1236,7 @@ Jason Wangsadinata Javier Kohen Javier Revillas Javier Segura +Jay Chen Jay Conrod Jay Lee Jay Taylor @@ -1200,6 +1259,7 @@ Jeff Johnson Jeff R. Allen Jeff Sickel Jeff Wendling +Jeff Widman Jeffrey H Jelte Fennema Jens Frederich @@ -1210,6 +1270,7 @@ Jeremy Faller Jeremy Jackins Jeremy Jay Jeremy Schlatter +Jero Bado Jeroen Bobbeldijk Jeroen Simonetti Jérôme Doucet @@ -1251,6 +1312,8 @@ Joe Richey Joe Shaw Joe Sylve Joe Tsai +Joel Courtney +Joel Ferrier Joel Sing Joël Stemmer Joel Stemmer @@ -1260,7 +1323,9 @@ Johan Euphrosine Johan Jansson Johan Knutzen Johan Sageryd +Johannes Huning John Asmuth +John Bampton John Beisley John C Barstow John DeNero @@ -1269,6 +1334,7 @@ John Gibb John Gilik John Graham-Cumming John Howard Palevich +John Jago John Jeffery John Jenkins John Leidegren @@ -1320,6 +1386,7 @@ Josa Gesell Jose Luis Vázquez González Joseph Bonneau Joseph Holsten +Joseph Morag Josh Baum Josh Bleecher Snyder Josh Chorlton @@ -1327,12 +1394,14 @@ Josh Deprez Josh Goebel Josh Hoak Josh Holland +Josh Rickmar Josh Roppo Josh Varga Joshua Bezaleel Abednego Joshua Boelter Joshua Chase Joshua Crowgey +Joshua Harshman Joshua M. Clulow Joshua Rubin Josselin Costanzi @@ -1353,6 +1422,7 @@ Julie Qiu Julien Kauffmann Julien Salleyron Julien Schmidt +Julien Tant Julio Montes Jun Zhang Junchen Li @@ -1419,10 +1489,12 @@ Kenta Mori Kerollos Magdy Ketan Parmar Kevan Swanberg +Kevin Albertson Kevin Ballard Kevin Burke Kévin Dunglas Kevin Gillette +Kevin Herro Kevin Kirsche Kevin Klues Kevin Malachowski @@ -1457,6 +1529,7 @@ Koya IWAMURA Kris Kwiatkowski Kris Nova Kris Rousey +Krishna Birla Kristopher Watts Krzysztof Dąbrowski Kshitij Saraogi @@ -1480,6 +1553,7 @@ Lajos Papp Lakshay Garg Lann Martin Lanre Adelowo +Lapo Luchini Larry Clapp Larry Hosken Lars Jeppesen @@ -1496,6 +1570,7 @@ Leigh McCulloch Leo Antunes Leo Rudberg Leon Klingele +Leonard Wang Leonardo Comelli Leonel Quinteros Lev Shamardin @@ -1506,7 +1581,9 @@ Lily Chung Lingchao Xin Lion Yang Liz Rice +Lize Cai Lloyd Dewolf +Lluís Batlle i Rossell Lorenz Bauer Lorenz Brun Lorenz Nickel @@ -1531,6 +1608,7 @@ Lukasz Milewski Luke Champine Luke Curley Luke Granger-Brown +Luke Shumaker Luke Young Luna Duclos Luuk van Dijk @@ -1550,6 +1628,7 @@ Mal Curtis Manfred Touron Manigandan Dharmalingam Manish Goregaokar +Manlio Perillo Manoj Dayaram Mansour Rahimi Manu Garg @@ -1646,6 +1725,8 @@ Matt Joiner Matt Jones Matt Juran Matt Layher +Matt Masurka +Matt Pearring Matt Reiferson Matt Robenolt Matt Strong @@ -1659,9 +1740,12 @@ Matthew Denton Matthew Holt Matthew Horsnell Matthew Waters +Matthias Frei Matthieu Hauglustaine Matthieu Olivier Matthijs Kooijman +Mattias Appelgren +Mauricio Alvarado Max Drosdo.www Max Riveiro Max Schmitt @@ -1677,9 +1761,11 @@ Máximo Cuadros Ortiz Maxwell Krohn Maya Rashish Mayank Kumar +Mehrad Sadeghi <2012.linkinpark@gmail.com> Meir Fischer Meng Zhuo Mhd Sulhan +Mia Zhu Micah Stetson Michael Anthony Knyszek Michael Brandenburg @@ -1730,8 +1816,10 @@ Michal Franc Michał Łowicki Michal Pristas Michal Rostecki +Michal Stokluska Michalis Kargakis Michel Lespinasse +Michel Levieux Michele Di Pede Mickael Kerjean Mickey Reiss @@ -1790,7 +1878,9 @@ Muir Manders Mukesh Sharma Mura Li Mykhailo Lesyk +Nahum Shalman Naman Aggarwal +Naman Gera Nan Deng Nao Yonashiro Naoki Kanatani @@ -1818,6 +1908,7 @@ Neven Sajko Nevins Bartolomeo Niall Sheridan Nic Day +Nicholas Asimov Nicholas Katsaros Nicholas Maniscalco Nicholas Ng @@ -1847,6 +1938,7 @@ Nik Nyby Nikhil Benesch Nikita Gillmann Nikita Kryuchkov +Nikita Melekhin Nikita Vanyasin Niklas Schnelle Niko Dziemba @@ -1858,6 +1950,7 @@ Niranjan Godbole Nishanth Shanmugham Noah Campbell Noah Goldman +Noah Santschi-Cooney Noble Johnson Nodir Turakulov Noel Georgi @@ -1894,6 +1987,7 @@ Pablo Rozas Larraondo Pablo Santiago Blum de Aguiar Padraig Kitterick Pallat Anchaleechamaikorn +Pan Chenglong <1004907659@qq.com> Panos Georgiadis Pantelis Sampaziotis Paolo Giarrusso @@ -1947,6 +2041,7 @@ Paulo Casaretto Paulo Flabiano Smorigo Paulo Gomes Pavel Paulau +Pavel Watson Pavel Zinovkin Pavlo Sumkin Pawel Knap @@ -1954,6 +2049,8 @@ Pawel Szczur Paweł Szulik Pei Xian Chee Pei-Ming Wu +Pen Tree +Peng Gao Percy Wegmann Perry Abbott Petar Dambovaliev @@ -1992,6 +2089,7 @@ Philip Brown Philip Hofer Philip K. Warren Philip Nelson +Philipp Sauter Philipp Stephani Phillip Campbell <15082+phillc@users.noreply.github.com> Pierre Carru @@ -2007,6 +2105,7 @@ Poh Zi How Polina Osadcha Pontus Leitzler Povilas Versockas +Prajwal Koirala <16564273+Prajwal-Koirala@users.noreply.github.com> Prasanga Siripala Prasanna Swaminathan Prashant Agrawal @@ -2027,11 +2126,13 @@ Quim Muntal Quinn Slack Quinten Yearsley Quoc-Viet Nguyen +Rabin Gaire Radek Simko Radek Sohlich Radu Berinde Rafal Jeczalik Raghavendra Nagaraj +Rahul Bajaj Rahul Chaudhry Rahul Wadhwani Raif S. Naffah @@ -2041,12 +2142,14 @@ Rajender Reddy Kompally Ralph Corderoy Ramazan AYYILDIZ Ramesh Dharan +Randy Reddig Raph Levien Raphael Geronimi Raul Silvera Ravil Bikbulatov RaviTeja Pothana Ray Tung +Ray Wu Raymond Kazlauskas Rebecca Stambler Reilly Watson @@ -2066,6 +2169,7 @@ Richard Eric Gavaletz Richard Gibson Richard Miller Richard Musiol +Richard Pickering Richard Ulmer Richard Wilkes Rick Arnold @@ -2124,6 +2228,7 @@ Rowan Worth Rudi Kramer Rui Ueyama Ruixin Bao +Ruslan Andreev Ruslan Nigmatullin Russ Cox Russell Haering @@ -2141,6 +2246,7 @@ Ryan Seys Ryan Slade Ryan Zhang Ryoichi KATO +Ryoya Sekino Ryuji Iwata Ryuma Yoshida Ryuzo Yamamoto @@ -2176,8 +2282,10 @@ Sardorbek Pulatov Sascha Brawer Sasha Lionheart Sasha Sobol +Satoru Kitaguchi Scott Barron Scott Bell +Scott Cotton Scott Crunkleton Scott Ferguson Scott Lawrence @@ -2191,6 +2299,7 @@ Sean Chittenden Sean Christopherson Sean Dolphin Sean Harger +Sean Harrington Sean Hildebrand Sean Liao Sean Rees @@ -2212,6 +2321,7 @@ Sergey Dobrodey Sergey Frolov Sergey Glushchenko Sergey Ivanov +Sergey Kacheev Sergey Lukjanov Sergey Mishin Sergey Mudrik @@ -2223,6 +2333,7 @@ Serhat Giydiren Serhii Aheienko Seth Hoenig Seth Vargo +Shaba Abhiram Shahar Kohanim Shailesh Suryawanshi Shamil Garatuev @@ -2250,9 +2361,13 @@ Shivakumar GN Shivani Singhal Shivansh Rai Shivashis Padhi +Shoshin Nikita +Shota Sugiura Shubham Sharma +Shuhei Takahashi Shun Fan Silvan Jegen +Simão Gomes Viana Simarpreet Singh Simon Drake Simon Ferquel @@ -2267,13 +2382,16 @@ Sina Siadat Sjoerd Siebinga Sokolov Yura Song Gao +Song Lim Songjiayang +Songlin Jiang Soojin Nam Søren L. Hansen Sparrow Li Spencer Kocot Spencer Nelson Spencer Tung +Spenser Black Spring Mc Srdjan Petrovic Sridhar Venkatakrishnan @@ -2324,6 +2442,7 @@ Suyash Suzy Mueller Sven Almgren Sven Blumenstein +Sven Lee Sven Taute Sylvain Zimmer Syohei YOSHIDA @@ -2406,12 +2525,14 @@ Tiwei Bie Tobias Assarsson Tobias Columbus Tobias Klauser +Tobias Kohlbau Toby Burress Todd Kulesza Todd Neal Todd Wang Tom Anthony Tom Bergan +Tom Freudenberg Tom Heng Tom Lanyon Tom Levy @@ -2440,6 +2561,7 @@ Toshiki Shima Totoro W Travis Bischel Travis Cline +Trevor Dixon Trevor Strohman Trey Lawrence Trey Roessig @@ -2463,6 +2585,7 @@ Tzach Shabtay Tzu-Chiao Yeh Tzu-Jung Lee Udalov Max +Uddeshya Singh Ugorji Nwoke Ulf Holm Nielsen Ulrich Kunitz @@ -2475,6 +2598,7 @@ Vadim Grek Vadim Vygonets Val Polouchkine Valentin Vidic +Vaughn Iverson Vee Zhang Vega Garcia Luis Alfonso Venil Noronha @@ -2491,6 +2615,7 @@ Vincent Batts Vincent Vanackere Vinu Rajashekhar Vish Subramanian +Vishal Dalwadi Vishvananda Ishaya Visweswara R Vitaly Zdanevich @@ -2542,6 +2667,7 @@ Willem van der Schyff William Chan William Chang William Josephson +William Langford William Orr William Poussier Wisdom Omuya @@ -2550,6 +2676,7 @@ Xi Ruoyao Xia Bin Xiangdong Ji Xiaodong Liu +Xing Gao <18340825824@163.com> Xing Xing Xingqang Bai Xu Fei @@ -2571,6 +2698,7 @@ Yasha Bubnov Yasser Abdolmaleki Yasuharu Goto Yasuhiro Matsumoto +Yasutaka Shinzaki Yasuyuki Oka Yazen Shunnar Yestin Sun @@ -2583,14 +2711,18 @@ Yorman Arias Yoshiyuki Kanno Yoshiyuki Mineo Yosuke Akatsuka +Youfu Zhang Yu Heng Zhang Yu Xuan Zhang +Yu, Li-Yu Yuichi Kishimoto Yuichi Nishiwaki Yuji Yaginuma +Yuki Ito Yuki OKUSHI Yuki Yugui Sonoda Yukihiro Nishinaka <6elpinal@gmail.com> +YunQiang Su Yury Smolsky Yusuke Kagiwada Yuusei Kuwana @@ -2599,6 +2731,7 @@ Yves Junqueira Zac Bergquist Zach Bintliff Zach Gershman +Zach Hoffman Zach Jones Zachary Amsden Zachary Gershman @@ -2617,6 +2750,7 @@ Zhou Peng Ziad Hatahet Ziheng Liu Zorion Arrizabalaga +Zvonimir Pavlinovic Zyad A. Ali Максадбек Ахмедов Максим Федосеев diff --git a/api/go1.17.txt b/api/go1.17.txt new file mode 100644 index 00000000000..48505381f1e --- /dev/null +++ b/api/go1.17.txt @@ -0,0 +1,195 @@ +pkg archive/zip, method (*File) OpenRaw() (io.Reader, error) +pkg archive/zip, method (*Writer) Copy(*File) error +pkg archive/zip, method (*Writer) CreateRaw(*FileHeader) (io.Writer, error) +pkg compress/lzw, method (*Reader) Close() error +pkg compress/lzw, method (*Reader) Read([]uint8) (int, error) +pkg compress/lzw, method (*Reader) Reset(io.Reader, Order, int) +pkg compress/lzw, method (*Writer) Close() error +pkg compress/lzw, method (*Writer) Reset(io.Writer, Order, int) +pkg compress/lzw, method (*Writer) Write([]uint8) (int, error) +pkg compress/lzw, type Reader struct +pkg compress/lzw, type Writer struct +pkg crypto/tls, method (*CertificateRequestInfo) Context() context.Context +pkg crypto/tls, method (*ClientHelloInfo) Context() context.Context +pkg crypto/tls, method (*Conn) HandshakeContext(context.Context) error +pkg database/sql, method (*NullByte) Scan(interface{}) error +pkg database/sql, method (*NullInt16) Scan(interface{}) error +pkg database/sql, method (NullByte) Value() (driver.Value, error) +pkg database/sql, method (NullInt16) Value() (driver.Value, error) +pkg database/sql, type NullByte struct +pkg database/sql, type NullByte struct, Byte uint8 +pkg database/sql, type NullByte struct, Valid bool +pkg database/sql, type NullInt16 struct +pkg database/sql, type NullInt16 struct, Int16 int16 +pkg database/sql, type NullInt16 struct, Valid bool +pkg debug/elf, const SHT_MIPS_ABIFLAGS = 1879048234 +pkg debug/elf, const SHT_MIPS_ABIFLAGS SectionType +pkg encoding/csv, method (*Reader) FieldPos(int) (int, int) +pkg go/build, type Context struct, ToolTags []string +pkg go/parser, const SkipObjectResolution = 64 +pkg go/parser, const SkipObjectResolution Mode +pkg image, method (*Alpha) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Alpha) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*Alpha16) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Alpha16) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*CMYK) RGBA64At(int, int) color.RGBA64 +pkg image, method (*CMYK) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*Gray) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Gray) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*Gray16) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Gray16) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*NRGBA) RGBA64At(int, int) color.RGBA64 +pkg image, method (*NRGBA) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*NRGBA64) RGBA64At(int, int) color.RGBA64 +pkg image, method (*NRGBA64) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*NYCbCrA) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Paletted) RGBA64At(int, int) color.RGBA64 +pkg image, method (*Paletted) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*RGBA) RGBA64At(int, int) color.RGBA64 +pkg image, method (*RGBA) SetRGBA64(int, int, color.RGBA64) +pkg image, method (*Uniform) RGBA64At(int, int) color.RGBA64 +pkg image, method (*YCbCr) RGBA64At(int, int) color.RGBA64 +pkg image, method (Rectangle) RGBA64At(int, int) color.RGBA64 +pkg image, type RGBA64Image interface { At, Bounds, ColorModel, RGBA64At } +pkg image, type RGBA64Image interface, At(int, int) color.Color +pkg image, type RGBA64Image interface, Bounds() Rectangle +pkg image, type RGBA64Image interface, ColorModel() color.Model +pkg image, type RGBA64Image interface, RGBA64At(int, int) color.RGBA64 +pkg image/draw, type RGBA64Image interface { At, Bounds, ColorModel, RGBA64At, Set, SetRGBA64 } +pkg image/draw, type RGBA64Image interface, At(int, int) color.Color +pkg image/draw, type RGBA64Image interface, Bounds() image.Rectangle +pkg image/draw, type RGBA64Image interface, ColorModel() color.Model +pkg image/draw, type RGBA64Image interface, RGBA64At(int, int) color.RGBA64 +pkg image/draw, type RGBA64Image interface, Set(int, int, color.Color) +pkg image/draw, type RGBA64Image interface, SetRGBA64(int, int, color.RGBA64) +pkg io/fs, func FileInfoToDirEntry(FileInfo) DirEntry +pkg math, const MaxFloat64 = 1.79769e+308 // 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368 +pkg math, const MaxInt = 9223372036854775807 +pkg math, const MaxInt ideal-int +pkg math, const MaxUint = 18446744073709551615 +pkg math, const MaxUint ideal-int +pkg math, const MinInt = -9223372036854775808 +pkg math, const MinInt ideal-int +pkg math, const SmallestNonzeroFloat32 = 1.4013e-45 // 1/713623846352979940529142984724747568191373312 +pkg math, const SmallestNonzeroFloat64 = 4.94066e-324 // 1/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784 +pkg net, method (*ParseError) Temporary() bool +pkg net, method (*ParseError) Timeout() bool +pkg net, method (IP) IsPrivate() bool +pkg net/http, func AllowQuerySemicolons(Handler) Handler +pkg net/url, method (Values) Has(string) bool +pkg reflect, func VisibleFields(Type) []StructField +pkg reflect, method (Method) IsExported() bool +pkg reflect, method (StructField) IsExported() bool +pkg reflect, method (Value) CanConvert(Type) bool +pkg runtime/cgo (darwin-amd64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (darwin-amd64-cgo), method (Handle) Delete() +pkg runtime/cgo (darwin-amd64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (darwin-amd64-cgo), type Handle uintptr +pkg runtime/cgo (freebsd-386-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (freebsd-386-cgo), method (Handle) Delete() +pkg runtime/cgo (freebsd-386-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (freebsd-386-cgo), type Handle uintptr +pkg runtime/cgo (freebsd-amd64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (freebsd-amd64-cgo), method (Handle) Delete() +pkg runtime/cgo (freebsd-amd64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (freebsd-amd64-cgo), type Handle uintptr +pkg runtime/cgo (freebsd-arm-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (freebsd-arm-cgo), method (Handle) Delete() +pkg runtime/cgo (freebsd-arm-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (freebsd-arm-cgo), type Handle uintptr +pkg runtime/cgo (linux-386-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (linux-386-cgo), method (Handle) Delete() +pkg runtime/cgo (linux-386-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (linux-386-cgo), type Handle uintptr +pkg runtime/cgo (linux-amd64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (linux-amd64-cgo), method (Handle) Delete() +pkg runtime/cgo (linux-amd64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (linux-amd64-cgo), type Handle uintptr +pkg runtime/cgo (linux-arm-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (linux-arm-cgo), method (Handle) Delete() +pkg runtime/cgo (linux-arm-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (linux-arm-cgo), type Handle uintptr +pkg runtime/cgo (netbsd-386-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (netbsd-386-cgo), method (Handle) Delete() +pkg runtime/cgo (netbsd-386-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (netbsd-386-cgo), type Handle uintptr +pkg runtime/cgo (netbsd-amd64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (netbsd-amd64-cgo), method (Handle) Delete() +pkg runtime/cgo (netbsd-amd64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (netbsd-amd64-cgo), type Handle uintptr +pkg runtime/cgo (netbsd-arm-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (netbsd-arm-cgo), method (Handle) Delete() +pkg runtime/cgo (netbsd-arm-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (netbsd-arm-cgo), type Handle uintptr +pkg runtime/cgo (netbsd-arm64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (netbsd-arm64-cgo), method (Handle) Delete() +pkg runtime/cgo (netbsd-arm64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (netbsd-arm64-cgo), type Handle uintptr +pkg runtime/cgo (openbsd-386-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (openbsd-386-cgo), method (Handle) Delete() +pkg runtime/cgo (openbsd-386-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (openbsd-386-cgo), type Handle uintptr +pkg runtime/cgo (openbsd-amd64-cgo), func NewHandle(interface{}) Handle +pkg runtime/cgo (openbsd-amd64-cgo), method (Handle) Delete() +pkg runtime/cgo (openbsd-amd64-cgo), method (Handle) Value() interface{} +pkg runtime/cgo (openbsd-amd64-cgo), type Handle uintptr +pkg strconv, func QuotedPrefix(string) (string, error) +pkg sync/atomic, method (*Value) CompareAndSwap(interface{}, interface{}) bool +pkg sync/atomic, method (*Value) Swap(interface{}) interface{} +pkg syscall (netbsd-386), const SYS_WAIT6 = 481 +pkg syscall (netbsd-386), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-386), const WEXITED = 32 +pkg syscall (netbsd-386), const WEXITED ideal-int +pkg syscall (netbsd-386-cgo), const SYS_WAIT6 = 481 +pkg syscall (netbsd-386-cgo), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-386-cgo), const WEXITED = 32 +pkg syscall (netbsd-386-cgo), const WEXITED ideal-int +pkg syscall (netbsd-amd64), const SYS_WAIT6 = 481 +pkg syscall (netbsd-amd64), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-amd64), const WEXITED = 32 +pkg syscall (netbsd-amd64), const WEXITED ideal-int +pkg syscall (netbsd-amd64-cgo), const SYS_WAIT6 = 481 +pkg syscall (netbsd-amd64-cgo), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-amd64-cgo), const WEXITED = 32 +pkg syscall (netbsd-amd64-cgo), const WEXITED ideal-int +pkg syscall (netbsd-arm), const SYS_WAIT6 = 481 +pkg syscall (netbsd-arm), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-arm), const WEXITED = 32 +pkg syscall (netbsd-arm), const WEXITED ideal-int +pkg syscall (netbsd-arm-cgo), const SYS_WAIT6 = 481 +pkg syscall (netbsd-arm-cgo), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-arm-cgo), const WEXITED = 32 +pkg syscall (netbsd-arm-cgo), const WEXITED ideal-int +pkg syscall (netbsd-arm64), const SYS_WAIT6 = 481 +pkg syscall (netbsd-arm64), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-arm64), const WEXITED = 32 +pkg syscall (netbsd-arm64), const WEXITED ideal-int +pkg syscall (netbsd-arm64-cgo), const SYS_WAIT6 = 481 +pkg syscall (netbsd-arm64-cgo), const SYS_WAIT6 ideal-int +pkg syscall (netbsd-arm64-cgo), const WEXITED = 32 +pkg syscall (netbsd-arm64-cgo), const WEXITED ideal-int +pkg syscall (openbsd-386), const MSG_CMSG_CLOEXEC = 2048 +pkg syscall (openbsd-386), const MSG_CMSG_CLOEXEC ideal-int +pkg syscall (openbsd-386-cgo), const MSG_CMSG_CLOEXEC = 2048 +pkg syscall (openbsd-386-cgo), const MSG_CMSG_CLOEXEC ideal-int +pkg syscall (openbsd-amd64), const MSG_CMSG_CLOEXEC = 2048 +pkg syscall (openbsd-amd64), const MSG_CMSG_CLOEXEC ideal-int +pkg syscall (openbsd-amd64-cgo), const MSG_CMSG_CLOEXEC = 2048 +pkg syscall (openbsd-amd64-cgo), const MSG_CMSG_CLOEXEC ideal-int +pkg syscall (windows-386), type SysProcAttr struct, AdditionalInheritedHandles []Handle +pkg syscall (windows-386), type SysProcAttr struct, ParentProcess Handle +pkg syscall (windows-amd64), type SysProcAttr struct, AdditionalInheritedHandles []Handle +pkg syscall (windows-amd64), type SysProcAttr struct, ParentProcess Handle +pkg testing, method (*B) Setenv(string, string) +pkg testing, method (*T) Setenv(string, string) +pkg testing, type TB interface, Setenv(string, string) +pkg text/template/parse, const SkipFuncCheck = 2 +pkg text/template/parse, const SkipFuncCheck Mode +pkg time, const Layout = "01/02 03:04:05PM '06 -0700" +pkg time, const Layout ideal-string +pkg time, func UnixMicro(int64) Time +pkg time, func UnixMilli(int64) Time +pkg time, method (Time) GoString() string +pkg time, method (Time) IsDST() bool +pkg time, method (Time) UnixMicro() int64 +pkg time, method (Time) UnixMilli() int64 diff --git a/api/next.txt b/api/next.txt index 9e996005c62..e69de29bb2d 100644 --- a/api/next.txt +++ b/api/next.txt @@ -1,99 +0,0 @@ -pkg compress/lzw, method (*Reader) Close() error -pkg compress/lzw, method (*Reader) Read([]uint8) (int, error) -pkg compress/lzw, method (*Reader) Reset(io.Reader, Order, int) -pkg compress/lzw, method (*Writer) Close() error -pkg compress/lzw, method (*Writer) Reset(io.Writer, Order, int) -pkg compress/lzw, method (*Writer) Write([]uint8) (int, error) -pkg compress/lzw, type Reader struct -pkg compress/lzw, type Writer struct -pkg crypto/tls, method (*CertificateRequestInfo) Context() context.Context -pkg crypto/tls, method (*ClientHelloInfo) Context() context.Context -pkg crypto/tls, method (*Conn) HandshakeContext(context.Context) error -pkg debug/elf, const SHT_MIPS_ABIFLAGS = 1879048234 -pkg debug/elf, const SHT_MIPS_ABIFLAGS SectionType -pkg encoding/csv, method (*Reader) FieldPos(int) (int, int) -pkg go/ast, method (*FuncDecl) IsMethod() bool -pkg go/build, type Context struct, ToolTags []string -pkg go/parser, const SkipObjectResolution = 64 -pkg go/parser, const SkipObjectResolution Mode -pkg go/types, type Config struct, GoVersion string -pkg io/fs, func FileInfoToDirEntry(FileInfo) DirEntry -pkg net, method (*ParseError) Temporary() bool -pkg net, method (*ParseError) Timeout() bool -pkg net, method (IP) IsPrivate() bool -pkg reflect, func VisibleFields(Type) []StructField -pkg reflect, method (Method) IsExported() bool -pkg reflect, method (StructField) IsExported() bool -pkg runtime/cgo (darwin-amd64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (darwin-amd64-cgo), method (Handle) Delete() -pkg runtime/cgo (darwin-amd64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (darwin-amd64-cgo), type Handle uintptr -pkg runtime/cgo (freebsd-386-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (freebsd-386-cgo), method (Handle) Delete() -pkg runtime/cgo (freebsd-386-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (freebsd-386-cgo), type Handle uintptr -pkg runtime/cgo (freebsd-amd64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (freebsd-amd64-cgo), method (Handle) Delete() -pkg runtime/cgo (freebsd-amd64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (freebsd-amd64-cgo), type Handle uintptr -pkg runtime/cgo (freebsd-arm-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (freebsd-arm-cgo), method (Handle) Delete() -pkg runtime/cgo (freebsd-arm-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (freebsd-arm-cgo), type Handle uintptr -pkg runtime/cgo (linux-386-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (linux-386-cgo), method (Handle) Delete() -pkg runtime/cgo (linux-386-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (linux-386-cgo), type Handle uintptr -pkg runtime/cgo (linux-amd64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (linux-amd64-cgo), method (Handle) Delete() -pkg runtime/cgo (linux-amd64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (linux-amd64-cgo), type Handle uintptr -pkg runtime/cgo (linux-arm-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (linux-arm-cgo), method (Handle) Delete() -pkg runtime/cgo (linux-arm-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (linux-arm-cgo), type Handle uintptr -pkg runtime/cgo (netbsd-386-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (netbsd-386-cgo), method (Handle) Delete() -pkg runtime/cgo (netbsd-386-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (netbsd-386-cgo), type Handle uintptr -pkg runtime/cgo (netbsd-amd64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (netbsd-amd64-cgo), method (Handle) Delete() -pkg runtime/cgo (netbsd-amd64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (netbsd-amd64-cgo), type Handle uintptr -pkg runtime/cgo (netbsd-arm-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (netbsd-arm-cgo), method (Handle) Delete() -pkg runtime/cgo (netbsd-arm-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (netbsd-arm-cgo), type Handle uintptr -pkg runtime/cgo (netbsd-arm64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (netbsd-arm64-cgo), method (Handle) Delete() -pkg runtime/cgo (netbsd-arm64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (netbsd-arm64-cgo), type Handle uintptr -pkg runtime/cgo (openbsd-386-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (openbsd-386-cgo), method (Handle) Delete() -pkg runtime/cgo (openbsd-386-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (openbsd-386-cgo), type Handle uintptr -pkg runtime/cgo (openbsd-amd64-cgo), func NewHandle(interface{}) Handle -pkg runtime/cgo (openbsd-amd64-cgo), method (Handle) Delete() -pkg runtime/cgo (openbsd-amd64-cgo), method (Handle) Value() interface{} -pkg runtime/cgo (openbsd-amd64-cgo), type Handle uintptr -pkg syscall (openbsd-386), const MSG_CMSG_CLOEXEC = 2048 -pkg syscall (openbsd-386), const MSG_CMSG_CLOEXEC ideal-int -pkg syscall (openbsd-386-cgo), const MSG_CMSG_CLOEXEC = 2048 -pkg syscall (openbsd-386-cgo), const MSG_CMSG_CLOEXEC ideal-int -pkg syscall (openbsd-amd64), const MSG_CMSG_CLOEXEC = 2048 -pkg syscall (openbsd-amd64), const MSG_CMSG_CLOEXEC ideal-int -pkg syscall (openbsd-amd64-cgo), const MSG_CMSG_CLOEXEC = 2048 -pkg syscall (openbsd-amd64-cgo), const MSG_CMSG_CLOEXEC ideal-int -pkg syscall (windows-386), type SysProcAttr struct, AdditionalInheritedHandles []Handle -pkg syscall (windows-386), type SysProcAttr struct, ParentProcess Handle -pkg syscall (windows-amd64), type SysProcAttr struct, AdditionalInheritedHandles []Handle -pkg syscall (windows-amd64), type SysProcAttr struct, ParentProcess Handle -pkg testing, method (*B) Setenv(string, string) -pkg testing, method (*T) Setenv(string, string) -pkg text/template/parse, const SkipFuncCheck = 2 -pkg text/template/parse, const SkipFuncCheck Mode -pkg time, func UnixMicro(int64) Time -pkg time, func UnixMilli(int64) Time -pkg time, method (*Time) IsDST() bool -pkg time, method (Time) UnixMicro() int64 -pkg time, method (Time) UnixMilli() int64 diff --git a/doc/asm.html b/doc/asm.html index 7173d9bd514..51f85eb9482 100644 --- a/doc/asm.html +++ b/doc/asm.html @@ -166,7 +166,7 @@ jumps and branches.
  • -SP: Stack pointer: top of stack. +SP: Stack pointer: the highest address within the local stack frame.
    • @@ -216,7 +216,7 @@ If a Go prototype does not name its result, the expected assembly name is The SP pseudo-register is a virtual stack pointer used to refer to frame-local variables and the arguments being prepared for function calls. -It points to the top of the local stack frame, so references should use negative offsets +It points to the highest address within the local stack frame, so references should use negative offsets in the range [−framesize, 0): x-8(SP), y-4(SP), and so on.

    @@ -409,7 +409,7 @@ The linker will choose one of the duplicates to use. (For TEXT items.) Don't insert the preamble to check if the stack must be split. The frame for the routine, plus anything it calls, must fit in the -spare space at the top of the stack segment. +spare space remaining in the current stack segment. Used to protect routines such as the stack splitting code itself.
  • @@ -460,7 +460,7 @@ Only valid on functions that declare a frame size of 0. TOPFRAME = 2048
    (For TEXT items.) -Function is the top of the call stack. Traceback should stop at this function. +Function is the outermost frame of the call stack. Traceback should stop at this function.
    • @@ -827,10 +827,6 @@ The other codes are -> (arithmetic right shift),

    ARM64

    -

    -The ARM64 port is in an experimental state. -

    -

    R18 is the "platform register", reserved on the Apple platform. To prevent accidental misuse, the register is named R18_PLATFORM. diff --git a/doc/go1.17.html b/doc/go1.17.html index cf856a1e735..c1b5ab3f6fb 100644 --- a/doc/go1.17.html +++ b/doc/go1.17.html @@ -14,23 +14,65 @@ Do not send CLs removing the interior tags from such phrases. main ul li { margin: 0.5em 0; } -

    DRAFT RELEASE NOTES — Introduction to Go 1.17

    +

    Introduction to Go 1.17

    - - Go 1.17 is not yet released. These are work-in-progress - release notes. Go 1.17 is expected to be released in August 2021. - + The latest Go release, version 1.17, arrives six months after Go 1.16. + Most of its changes are in the implementation of the toolchain, runtime, and libraries. + As always, the release maintains the Go 1 promise of compatibility. + We expect almost all Go programs to continue to compile and run as before.

    Changes to the language

    -

    - TODO: https://golang.org/cl/216424: allow conversion from slice to array ptr +

    + Go 1.17 includes three small enhancements to the language.

    -

    - TODO: https://golang.org/cl/312212: add unsafe.Add and unsafe.Slice +

      +
    • + Conversions + from slice to array pointer: An expression s of + type []T may now be converted to array pointer type + *[N]T. If a is the result of such a + conversion, then corresponding indices that are in range refer to + the same underlying elements: &a[i] == &s[i] + for 0 <= i < N. The conversion panics if + len(s) is less than N. +
      • + +
    • + unsafe.Add: + unsafe.Add(ptr, len) adds len + to ptr and returns the updated pointer + unsafe.Pointer(uintptr(ptr) + uintptr(len)). +
      • + +
    • + unsafe.Slice: + For expression ptr of type *T, + unsafe.Slice(ptr, len) returns a slice of + type []T whose underlying array starts + at ptr and whose length and capacity + are len. +
      • +
    + +

    + The package unsafe enhancements were added to simplify writing code that conforms + to unsafe.Pointer's safety + rules, but the rules remain unchanged. In particular, existing + programs that correctly use unsafe.Pointer remain + valid, and new programs must still follow the rules when + using unsafe.Add or unsafe.Slice. +

    + + +

    + Note that the new conversion from slice to array pointer is the + first case in which a type conversion can panic at run time. + Analysis tools that assume type conversions can never panic + should be updated to consider this possibility.

    Ports

    @@ -43,44 +85,145 @@ Do not send CLs removing the interior tags from such phrases. for previous versions has been discontinued.

    -

    - TODO: complete the Ports section +

    Windows

    + +

    + Go 1.17 adds support of 64-bit ARM architecture on Windows (the + windows/arm64 port). This port supports cgo. +

    + +

    OpenBSD

    + +

    + The 64-bit MIPS architecture on OpenBSD (the openbsd/mips64 + port) now supports cgo. +

    + +

    + In Go 1.16, on the 64-bit x86 and 64-bit ARM architectures on + OpenBSD (the openbsd/amd64 and openbsd/arm64 + ports) system calls are made through libc, instead + of directly using machine instructions. In Go 1.17, this is also + done on the 32-bit x86 and 32-bit ARM architectures on OpenBSD + (the openbsd/386 and openbsd/arm ports). + This ensures compatibility with OpenBSD 6.9 onwards, which require + system calls to be made through libc for non-static + Go binaries. +

    + +

    ARM64

    + +

    + Go programs now maintain stack frame pointers on the 64-bit ARM + architecture on all operating systems. Previously it maintained + stack frame pointers only on Linux, macOS, and iOS. +

    + +

    loong64 GOARCH value reserved

    + +

    + The main Go compiler does not yet support the LoongArch + architecture, but we've reserved the GOARCH value + "loong64". + This means that Go files named *_loong64.go will now + be ignored by Go + tools except when that GOARCH value is being used.

    Tools

    -

    - TODO: complete the Tools section -

    -

    Go command

    -

    Lazy module loading

    + +

    Pruned module graphs in go 1.17 modules

    - If a module specifies go 1.17 or higher in its - go.mod file, its transitive requirements are now loaded lazily, - avoding the need to download or read go.mod files for - otherwise-irrelevant dependencies. To support lazy loading, in Go 1.17 modules - the go command maintains explicit requirements in - the go.mod file for every dependency that provides any package - transitively imported by any package or test within the module. - See the design - document for more detail. - + If a module specifies go 1.17 or higher, the module + graph includes only the immediate dependencies of + other go 1.17 modules, not their full transitive + dependencies. (See Module graph pruning + for more detail.)

    -

    To facilitate the upgrade to lazy loading, - the go mod tidy subcommand now supports - a -go flag to set or change the go version in - the go.mod file. To enable lazy loading for an existing module - without changing the selected versions of its dependencies, run: +

    + For the go command to correctly resolve transitive imports using + the pruned module graph, the go.mod file for each module needs to + include more detail about the transitive dependencies relevant to that module. + If a module specifies go 1.17 or higher in its + go.mod file, its go.mod file now contains an + explicit require + directive for every module that provides a transitively-imported package. + (In previous versions, the go.mod file typically only included + explicit requirements for directly-imported packages.) +

    + +

    + Since the expanded go.mod file needed for module graph pruning + includes all of the dependencies needed to load the imports of any package in + the main module, if the main module specifies + go 1.17 or higher the go tool no longer + reads (or even downloads) go.mod files for dependencies if they + are not needed in order to complete the requested command. + (See Lazy loading.) +

    + +

    + Because the number of explicit requirements may be substantially larger in an + expanded Go 1.17 go.mod file, the newly-added requirements + on indirect dependencies in a go 1.17 + module are maintained in a separate require block from the block + containing direct dependencies. +

    + +

    + To facilitate the upgrade to Go 1.17 pruned module graphs, the + go mod tidy + subcommand now supports a -go flag to set or change + the go version in the go.mod file. To convert + the go.mod file for an existing module to Go 1.17 without + changing the selected versions of its dependencies, run: 

       go mod tidy -go=1.17
    +

    + By default, go mod tidy verifies that + the selected versions of dependencies relevant to the main module are the same + versions that would be used by the prior Go release (Go 1.16 for a module that + specifies go 1.17), and preserves + the go.sum entries needed by that release even for dependencies + that are not normally needed by other commands. +

    + +

    + The -compat flag allows that version to be overridden to support + older (or only newer) versions, up to the version specified by + the go directive in the go.mod file. To tidy + a go 1.17 module for Go 1.17 only, without saving + checksums for (or checking for consistency with) Go 1.16: +

    + +
    +  go mod tidy -compat=1.17
+
    + +

    + Note that even if the main module is tidied with -compat=1.17, + users who require the module from a + go 1.16 or earlier module will still be able to + use it, provided that the packages use only compatible language and library + features. +

    + +

    + The go mod graph + subcommand also supports the -go flag, which causes it to report + the graph as seen by the indicated Go version, showing dependencies that may + otherwise be pruned out. +

    +

    Module deprecation comments

    @@ -108,6 +251,16 @@ Do not send CLs removing the interior tags from such phrases. environment for details.

    +

    + go get prints a deprecation warning when installing + commands outside the main module (without the -d flag). + go install cmd@version should be used + instead to install a command at a specific version, using a suffix like + @latest or @v1.2.3. In Go 1.18, the -d + flag will always be enabled, and go get will only + be used to change dependencies in go.mod. +

    +

    go.mod files missing go directives

    @@ -136,7 +289,8 @@ Do not send CLs removing the interior tags from such phrases.

    If the main module specifies go 1.17 or higher, - go mod vendor now annotates + go mod vendor + now annotates vendor/modules.txt with the go version indicated by each vendored module in its own go.mod file. The annotated version is used when building the module's packages from vendored source code. @@ -161,72 +315,190 @@ Do not send CLs removing the interior tags from such phrases. password-protected SSH keys.

    -

    - TODO: https://golang.org/cl/249759: cmd/cover: replace code using optimized golang.org/x/tools/cover +

    go mod download

    + +

    + When go mod download is invoked without + arguments, it will no longer save sums for downloaded module content to + go.sum. It may still make changes to go.mod and + go.sum needed to load the build list. This is the same as the + behavior in Go 1.15. To save sums for all modules, use go + mod download all. +

    + +

    //go:build lines

    + +

    + The go command now understands //go:build lines + and prefers them over // +build lines. The new syntax uses + boolean expressions, just like Go, and should be less error-prone. + As of this release, the new syntax is fully supported, and all Go files + should be updated to have both forms with the same meaning. To aid in + migration, gofmt now automatically + synchronizes the two forms. For more details on the syntax and migration plan, + see + https://golang.org/design/draft-gobuild. +

    + +

    go run

    + +

    + go run now accepts arguments with version suffixes + (for example, go run + example.com/cmd@v1.0.0). This causes go + run to build and run packages in module-aware mode, ignoring the + go.mod file in the current directory or any parent directory, if + there is one. This is useful for running executables without installing them or + without changing dependencies of the current module. +

    + +

    Gofmt

    + +

    + gofmt (and go fmt) now synchronizes + //go:build lines with // +build lines. If a file + only has // +build lines, they will be moved to the appropriate + location in the file, and matching //go:build lines will be + added. Otherwise, // +build lines will be overwritten based on + any existing //go:build lines. For more information, see + https://golang.org/design/draft-gobuild.

    Vet

    +

    New warning for mismatched //go:build and // +build lines

    + +

    + The vet tool now verifies that //go:build and + // +build lines are in the correct part of the file and + synchronized with each other. If they aren't, + gofmt can be used to fix them. For more + information, see + https://golang.org/design/draft-gobuild. +

    + +

    New warning for calling signal.Notify on unbuffered channels

    +

    - TODO: https://golang.org/cl/299532: cmd/vet: bring in sigchanyzer to report unbuffered channels to signal.Notify + The vet tool now warns about calls to signal.Notify + with incoming signals being sent to an unbuffered channel. Using an unbuffered channel + risks missing signals sent on them as signal.Notify does not block when + sending to a channel. For example:

    +
    +c := make(chan os.Signal)
+// signals are sent on c before the channel is read from.
+// This signal may be dropped as c is unbuffered.
+signal.Notify(c, os.Interrupt)
+
    +

    - TODO: complete the Vet section + Users of signal.Notify should use channels with sufficient buffer space to keep up with the + expected signal rate.

    -

    Runtime

    +

    New warnings for Is, As and Unwrap methods

    -

    - TODO: https://golang.org/cl/304470: cmd/compile, runtime: add metadata for argument printing in traceback +

    + The vet tool now warns about methods named As, Is or Unwrap + on types implementing the error interface that have a different signature than the + one expected by the errors package. The errors.{As,Is,Unwrap} functions + expect such methods to implement either Is(error) bool, + As(interface{}) bool, or Unwrap() error + respectively. The functions errors.{As,Is,Unwrap} will ignore methods with the same + names but a different signature. For example:

    -

    - TODO: complete the Runtime section +

    +type MyError struct { hint string }
+func (m MyError) Error() string { ... } // MyError implements error.
+func (MyError) Is(target interface{}) bool { ... } // target is interface{} instead of error.
+func Foo() bool {
+	x, y := MyError{"A"}, MyError{"B"}
+	return errors.Is(x, y) // returns false as x != y and MyError does not have an `Is(error) bool` function.
+}
+
    + +

    Cover

    + +

    + The cover tool now uses an optimized parser + from golang.org/x/tools/cover, which may be noticeably faster + when parsing large coverage profiles.

    Compiler

    -

    - TODO: complete the Compiler section, or delete if not needed +

    + Go 1.17 implements a new way of passing function arguments and results using + registers instead of the stack. + Benchmarks for a representative set of Go packages and programs show + performance improvements of about 5%, and a typical reduction in + binary size of about 2%. + This is currently enabled for Linux, macOS, and Windows on the + 64-bit x86 architecture (the linux/amd64, + darwin/amd64, and windows/amd64 ports).

    -

    Linker

    -

    - TODO: complete the Linker section, or delete if not needed + This change does not affect the functionality of any safe Go code + and is designed to have no impact on most assembly code. + It may affect code that violates + the unsafe.Pointer + rules when accessing function arguments, or that depends on + undocumented behavior involving comparing function code pointers. + To maintain compatibility with existing assembly functions, the + compiler generates adapter functions that convert between the new + register-based calling convention and the previous stack-based + calling convention. + These adapters are typically invisible to users, except that taking + the address of a Go function in assembly code or taking the address + of an assembly function in Go code + using reflect.ValueOf(fn).Pointer() + or unsafe.Pointer will now return the address of the + adapter. + Code that depends on the value of these code pointers may no longer + behave as expected. + Adapters also may cause a very small performance overhead in two + cases: calling an assembly function indirectly from Go via + a func value, and calling Go functions from assembly. +

    + +

    + The format of stack traces from the runtime (printed when an uncaught panic + occurs, or when runtime.Stack is called) is improved. Previously, + the function arguments were printed as hexadecimal words based on the memory + layout. Now each argument in the source code is printed separately, separated + by commas. Aggregate-typed (struct, array, string, slice, interface, and complex) + arguments are delimited by curly braces. A caveat is that the value of an + argument that only lives in a register and is not stored to memory may be + inaccurate. Function return values (which were usually inaccurate) are no longer + printed. +

    + +

    + Functions containing closures can now be inlined. + One effect of this change is that a function with a closure may + produce a distinct closure code pointer for each place that the + function is inlined. + Go function values are not directly comparable, but this change + could reveal bugs in code that uses reflect + or unsafe.Pointer to bypass this language restriction + and compare functions by code pointer. +

    + + + +

    + When the linker uses external linking mode, which is the default + when linking a program that uses cgo, and the linker is invoked + with a -I option, the option will now be passed to the + external linker as a -Wl,--dynamic-linker option.

    Core library

    -

    - TODO: complete the Core library section -

    - -

    crypto/tls

    - -

    - (*Conn).HandshakeContext was added to - allow the user to control cancellation of an in-progress TLS Handshake. - The context provided is propagated into the - ClientHelloInfo - and CertificateRequestInfo - structs and accessible through the new - (*ClientHelloInfo).Context - and - - (*CertificateRequestInfo).Context - methods respectively. Canceling the context after the handshake has finished - has no effect. -

    - -

    - When Config.NextProtos is set, servers now - enforce that there is an overlap between the configured protocols and the protocols - advertised by the client, if any. If there is no overlap the connection is closed - with the no_application_protocol alert, as required by RFC 7301. -

    -

    Cgo

    @@ -236,6 +508,67 @@ Do not send CLs removing the interior tags from such phrases. runtime/cgo.Handle for more information.

    +

    URL query parsing

    + + +

    + The net/url and net/http packages used to accept + ";" (semicolon) as a setting separator in URL queries, in + addition to "&" (ampersand). Now, settings with non-percent-encoded + semicolons are rejected and net/http servers will log a warning to + Server.ErrorLog + when encountering one in a request URL. +

    + +

    + For example, before Go 1.17 the Query + method of the URL example?a=1;b=2&c=3 would have returned + map[a:[1] b:[2] c:[3]], while now it returns map[c:[3]]. +

    + +

    + When encountering such a query string, + URL.Query + and + Request.FormValue + ignore any settings that contain a semicolon, + ParseQuery + returns the remaining settings and an error, and + Request.ParseForm + and + Request.ParseMultipartForm + return an error but still set Request fields based on the + remaining settings. +

    + +

    + net/http users can restore the original behavior by using the new + AllowQuerySemicolons + handler wrapper. This will also suppress the ErrorLog warning. + Note that accepting semicolons as query separators can lead to security issues + if different systems interpret cache keys differently. + See issue 25192 for more information. +

    + +

    TLS strict ALPN

    + + +

    + When Config.NextProtos + is set, servers now enforce that there is an overlap between the configured + protocols and the ALPN protocols advertised by the client, if any. If there is + no mutually supported protocol, the connection is closed with the + no_application_protocol alert, as required by RFC 7301. This + helps mitigate the ALPACA cross-protocol attack. +

    + +

    + As an exception, when the value "h2" is included in the server's + Config.NextProtos, HTTP/1.1 clients will be allowed to connect as + if they didn't support ALPN. + See issue 46310 for more information. +

    +

    Minor changes to the library

    @@ -247,7 +580,7 @@ Do not send CLs removing the interior tags from such phrases.

    archive/zip

    - TODO: https://golang.org/cl/312310: add File.OpenRaw, Writer.CreateRaw, Writer.Copy + The new methods File.OpenRaw, Writer.CreateRaw, Writer.Copy provide support for cases where performance is a primary concern.

    @@ -275,35 +608,170 @@ Do not send CLs removing the interior tags from such phrases.
    compress/lzw

    - The new - Reader.Reset - and - Writer.Reset - methods allow reuse of a Reader or Writer. + The NewReader + function is guaranteed to return a value of the new + type Reader, + and similarly NewWriter + is guaranteed to return a value of the new + type Writer. + These new types both implement a Reset method + (Reader.Reset, + Writer.Reset) + that allows reuse of the Reader or Writer.

    -
    crypto/rsa
    +
    crypto/ed25519
    -

    - TODO: https://golang.org/cl/302230: fix salt length calculation with PSSSaltLengthAuto +

    + The crypto/ed25519 package has been rewritten, and all + operations are now approximately twice as fast on amd64 and arm64. + The observable behavior has not otherwise changed.

    -
    +
    + +
    crypto/elliptic
    +
    +

    + CurveParams + methods now automatically invoke faster and safer dedicated + implementations for known curves (P-224, P-256, and P-521) when + available. Note that this is a best-effort approach and applications + should avoid using the generic, not constant-time CurveParams + methods and instead use dedicated + Curve implementations + such as P256. +

    + +

    + The P521 curve + implementation has been rewritten using code generated by the + fiat-crypto project, + which is based on a formally-verified model of the arithmetic + operations. It is now constant-time and three times faster on amd64 and + arm64. The observable behavior has not otherwise changed. +

    +
    +
    + +
    crypto/rand
    +
    +

    + The crypto/rand package now uses the getentropy + syscall on macOS and the getrandom syscall on Solaris, + Illumos, and DragonFlyBSD. +

    +
    +
    + +
    crypto/tls
    +
    +

    + The new Conn.HandshakeContext + method allows the user to control cancellation of an in-progress TLS + handshake. The provided context is accessible from various callbacks through the new + ClientHelloInfo.Context and + CertificateRequestInfo.Context + methods. Canceling the context after the handshake has finished has no effect. +

    + +

    + Cipher suite ordering is now handled entirely by the + crypto/tls package. Currently, cipher suites are sorted based + on their security, performance, and hardware support taking into account + both the local and peer's hardware. The order of the + Config.CipherSuites + field is now ignored, as well as the + Config.PreferServerCipherSuites + field. Note that Config.CipherSuites still allows + applications to choose what TLS 1.0–1.2 cipher suites to enable. +

    + +

    + The 3DES cipher suites have been moved to + InsecureCipherSuites + due to fundamental block size-related + weakness. They are still enabled by default but only as a last resort, + thanks to the cipher suite ordering change above. +

    + +

    + Beginning in the next release, Go 1.18, the + Config.MinVersion + for crypto/tls clients will default to TLS 1.2, disabling TLS 1.0 + and TLS 1.1 by default. Applications will be able to override the change by + explicitly setting Config.MinVersion. + This will not affect crypto/tls servers. +

    +
    +
    + +
    crypto/x509
    +
    +

    + CreateCertificate + now returns an error if the provided private key doesn't match the + parent's public key, if any. The resulting certificate would have failed + to verify. +

    + +

    + The temporary GODEBUG=x509ignoreCN=0 flag has been removed. +

    + +

    + ParseCertificate + has been rewritten, and now consumes ~70% fewer resources. The observable + behavior has not otherwise changed, except for error messages. +

    + +

    + On BSD systems, /etc/ssl/certs is now searched for trusted + roots. This adds support for the new system trusted certificate store in + FreeBSD 12.2+. +

    + +

    + Beginning in the next release, Go 1.18, crypto/x509 will + reject certificates signed with the SHA-1 hash function. This doesn't + apply to self-signed root certificates. Practical attacks against SHA-1 + have been demonstrated in 2017 and publicly + trusted Certificate Authorities have not issued SHA-1 certificates since 2015. +

    +
    +
    database/sql

    - TODO: https://golang.org/cl/258360: close driver.Connector if it implements io.Closer + The DB.Close method now closes + the connector field if the type in this field implements the + io.Closer interface.

    - TODO: https://golang.org/cl/311572: add NullInt16 and NullByte + The new + NullInt16 + and + NullByte + structs represent the int16 and byte values that may be null. These can be used as + destinations of the Scan method, + similar to NullString.

    +
    debug/elf
    +
    +

    + The SHT_MIPS_ABIFLAGS + constant has been added. +

    +
    +
    +
    encoding/binary

    @@ -315,18 +783,96 @@ Do not send CLs removing the interior tags from such phrases.

    +
    encoding/csv
    +
    +

    + The new + Reader.FieldPos + method returns the line and column corresponding to the start of + a given field in the record most recently returned by + Read. +

    +
    +
    + +
    encoding/xml
    +
    +

    + When a comment appears within a + Directive, it is now replaced + with a single space instead of being completely elided. +

    + +

    + Invalid element or attribute names with leading, trailing, or multiple + colons are now stored unmodified into the + Name.Local field. +

    +
    +
    +
    flag

    - TODO: https://golang.org/cl/271788: panic if flag name begins with - or contains = + Flag declarations now panic if an invalid name is specified.

    +
    go/build
    +
    +

    + The new + Context.ToolTags + field holds the build tags appropriate to the current Go + toolchain configuration. +

    +
    +
    + +
    go/format
    +
    +

    + The Source and + Node functions now + synchronize //go:build lines with // +build + lines. If a file only has // +build lines, they will be + moved to the appropriate location in the file, and matching + //go:build lines will be added. Otherwise, + // +build lines will be overwritten based on any existing + //go:build lines. For more information, see + https://golang.org/design/draft-gobuild. +

    +
    +
    + +
    go/parser
    +
    +

    + The new SkipObjectResolution + Mode value instructs the parser not to resolve identifiers to + their declaration. This may improve parsing speed. +

    +
    +
    + +
    image
    +
    +

    + The concrete image types (RGBA, Gray16 and so on) + now implement a new RGBA64Image + interface. The concrete types that previously implemented + draw.Image now also implement + draw.RGBA64Image, a + new interface in the image/draw package. +

    +
    +
    +
    io/fs

    - TODO: https://golang.org/cl/293649: implement FileInfoToDirEntry + The new FileInfoToDirEntry function converts a FileInfo to a DirEntry.

    @@ -334,7 +880,9 @@ Do not send CLs removing the interior tags from such phrases.
    math

    - TODO: https://golang.org/cl/247058: add MaxUint, MinInt, MaxInt + The math package now defines three more constants: MaxUint, MaxInt and MinInt. + For 32-bit systems their values are 2^32 - 1, 2^31 - 1 and -2^31, respectively. + For 64-bit systems their values are 2^64 - 1, 2^63 - 1 and -2^63, respectively.

    @@ -342,23 +890,54 @@ Do not send CLs removing the interior tags from such phrases.
    mime

    - TODO: https://golang.org/cl/305230: support reading shared mime-info database on unix systems + On Unix systems, the table of MIME types is now read from the local system's + Shared MIME-info Database + when available.

    +
    mime/multipart
    +
    +

    + Part.FileName + now applies + filepath.Base to the + return value. This mitigates potential path traversal vulnerabilities in + applications that accept multipart messages, such as net/http + servers that call + Request.FormFile. +

    +
    +
    +
    net

    - TODO: https://golang.org/cl/272668: add IP.IsPrivate + The new method IP.IsPrivate reports whether an address is + a private IPv4 address according to RFC 1918 + or a local IPv6 address according RFC 4193.

    - TODO: https://golang.org/cl/301709: make go resolver aware of network parameter + The Go DNS resolver now only sends one DNS query when resolving an address for an IPv4-only or IPv6-only network, + rather than querying for both address families.

    - TODO: https://golang.org/cl/307030: make ErrClosed and ParseError implement net.Error + The ErrClosed sentinel error and + ParseError error type now implement + the net.Error interface. +

    + +

    + The ParseIP and ParseCIDR + functions now reject IPv4 addresses which contain decimal components with leading zeros. + + These components were always interpreted as decimal, but some operating systems treat them as octal. + This mismatch could hypothetically lead to security issues if a Go application was used to validate IP addresses + which were then used in their original form with non-Go applications which interpreted components as octal. Generally, + it is advisable to always re-encode values after validation, which avoids this class of parser misalignment issues.

    @@ -373,11 +952,37 @@ Do not send CLs removing the interior tags from such phrases.

    - TODO: https://golang.org/cl/235437: add to deadlines only when positive + Setting the Server + ReadTimeout or WriteTimeout fields to a negative value now indicates no timeout + rather than an immediate timeout.

    - TODO: https://golang.org/cl/308952: make ReadRequest return an error when requests have multiple Host headers + The ReadRequest function + now returns an error when the request has multiple Host headers. +

    + +

    + When producing a redirect to the cleaned version of a URL, + ServeMux now always + uses relative URLs in the Location header. Previously it + would echo the full URL of the request, which could lead to unintended + redirects if the client could be made to send an absolute request URL. +

    + +

    + When interpreting certain HTTP headers handled by net/http, + non-ASCII characters are now ignored or rejected. +

    + +

    + If + Request.ParseForm + returns an error when called by + Request.ParseMultipartForm, + the latter now continues populating + Request.MultipartForm + before returning it.

    @@ -385,7 +990,10 @@ Do not send CLs removing the interior tags from such phrases.
    net/http/httptest

    - TODO: https://golang.org/cl/308950: panic on non-3 digit (XXX) status code in Recorder.WriteHeader + ResponseRecorder.WriteHeader + now panics when the provided code is not a valid three-digit HTTP status code. + This matches the behavior of ResponseWriter + implementations in the net/http package.

    @@ -393,7 +1001,8 @@ Do not send CLs removing the interior tags from such phrases.
    net/url

    - TODO: https://golang.org/cl/314850: add Values.Has + The new method Values.Has + reports whether a query parameter is set.

    @@ -401,13 +1010,26 @@ Do not send CLs removing the interior tags from such phrases.
    os

    - TODO: https://golang.org/cl/268020: avoid allocation in File.WriteString + The File.WriteString method + has been optimized to not make a copy of the input string.

    reflect
    +

    + The new + Value.CanConvert + method reports whether a value can be converted to a type. + This may be used to avoid a panic when converting a slice to an + array pointer type if the slice is too short. + Previously it was sufficient to use + Type.ConvertibleTo + for this, but the newly permitted conversion from slice to array + pointer type can panic even if the types are convertible. +

    +

    The new StructField.IsExported @@ -419,23 +1041,49 @@ Do not send CLs removing the interior tags from such phrases.

    - TODO: https://golang.org/cl/281233: add VisibleFields function + The new VisibleFields function + returns all the visible fields in a struct type, including fields inside anonymous struct members.

    - TODO: https://golang.org/cl/284136: panic if ArrayOf is called with negative length + The ArrayOf function now panics when + called with a negative length. +

    + +

    + Checking the Type.ConvertibleTo method + is no longer sufficient to guarantee that a call to + Value.Convert will not panic. + It may panic when converting `[]T` to `*[N]T` if the slice's length is less than N. + See the language changes section above.

    +
    runtime/metrics
    +
    +

    + New metrics were added that track total bytes and objects allocated and freed. + A new metric tracking the distribution of goroutine scheduling latencies was + also added. +

    +
    +
    + +
    runtime/pprof
    +
    +

    + Block profiles are no longer biased to favor infrequent long events over + frequent short events. +

    +
    +
    +
    strconv
    -

    - TODO: https://golang.org/cl/170079: implement Ryū-like algorithm for fixed precision ftoa -

    - -

    - TODO: https://golang.org/cl/170080: Implement Ryū algorithm for ftoa shortest mode +

    + The strconv package now uses Ulf Adams's Ryū algorithm for formatting floating-point numbers. + This algorithm improves performance on most inputs and is more than 99% faster on worst-case inputs.

    @@ -460,7 +1108,9 @@ Do not send CLs removing the interior tags from such phrases.

    sync/atomic

    - TODO: https://golang.org/cl/241678: add (*Value).Swap and (*Value).CompareAndSwap + atomic.Value now has Swap and + CompareAndSwap methods that provide + additional atomic operations.

    @@ -468,11 +1118,38 @@ Do not send CLs removing the interior tags from such phrases.
    syscall

    - TODO: https://golang.org/cl/295371: do not overflow key memory in GetQueuedCompletionStatus +

    + The GetQueuedCompletionStatus and + PostQueuedCompletionStatus + functions are now deprecated. These functions have incorrect signatures and are superseded by + equivalents in the golang.org/x/sys/windows package.

    - TODO: https://golang.org/cl/313653: restore signal mask after setting foreground process group + On Unix-like systems, the process group of a child process is now set with signals blocked. + This avoids sending a SIGTTOU to the child when the parent is in a background process group. +

    + +

    + The Windows version of + SysProcAttr + has two new fields. AdditionalInheritedHandles is + a list of additional handles to be inherited by the new child + process. ParentProcess permits specifying the + parent process of the new process. + +

    + The constant MSG_CMSG_CLOEXEC is now defined on + DragonFly and all OpenBSD systems (it was already defined on + some OpenBSD systems and all FreeBSD, NetBSD, and Linux systems). +

    + +

    + The constants SYS_WAIT6 and WEXITED + are now defined on NetBSD systems (SYS_WAIT6 was + already defined on DragonFly and FreeBSD systems; + WEXITED was already defined on Darwin, DragonFly, + FreeBSD, Linux, and Solaris systems).

    @@ -480,7 +1157,14 @@ Do not send CLs removing the interior tags from such phrases.
    testing

    - TODO: https://golang.org/cl/310033: add -shuffle=off|on|N to alter the execution order of tests and benchmarks + Added a new testing flag -shuffle which controls the execution order of tests and benchmarks. +

    +

    + The new + T.Setenv + and B.Setenv + methods support setting an environment variable for the duration + of the test or benchmark.

    @@ -488,7 +1172,8 @@ Do not send CLs removing the interior tags from such phrases.
    text/template/parse

    - TODO: https://golang.org/cl/301493: add a mode to skip func-check on parsing + The new SkipFuncCheck Mode + value changes the template parser to not verify that functions are defined.

    @@ -496,21 +1181,41 @@ Do not send CLs removing the interior tags from such phrases.
    time

    - time.Time now has a GoString - method that will return a more useful value for times when printed with - the "%#v" format specifier in the fmt package. + The Time type now has a + GoString method that + will return a more useful value for times when printed with the + %#v format specifier in the fmt package.

    - TODO: https://golang.org/cl/264077: add Time.IsDST() to check if its Location is in Daylight Savings Time + The new Time.IsDST method can be used to check whether the time + is in Daylight Savings Time in its configured location.

    - TODO: https://golang.org/cl/293349: add Time.Unix{Milli,Micro} and to-Time helpers UnixMicro, UnixMilli + The new Time.UnixMilli and + Time.UnixMicro + methods return the number of milliseconds and microseconds elapsed since + January 1, 1970 UTC respectively. +
    + The new UnixMilli and + UnixMicro functions + return the local Time corresponding to the given Unix time.

    - TODO: https://golang.org/cl/300996: support "," as separator for fractional seconds + The package now accepts comma "," as a separator for fractional seconds when parsing and formatting time. + For example, the following time layouts are now accepted: +

      +
    • 2006-01-02 15:04:05,999999999 -0700 MST
      • +
    • Mon Jan _2 15:04:05,000000 2006
      • +
    • Monday, January 2 15:04:05,000 2006
      • +
    +

    + +

    + The new constant Layout + defines the reference time.

    diff --git a/doc/go_spec.html b/doc/go_spec.html index e59b3554f28..fd5fee46eb2 100644 --- a/doc/go_spec.html +++ b/doc/go_spec.html @@ -1,6 +1,6 @@ @@ -490,8 +490,8 @@ After a backslash, certain single-character escapes represent special values: \n U+000A line feed or newline \r U+000D carriage return \t U+0009 horizontal tab -\v U+000b vertical tab -\\ U+005c backslash +\v U+000B vertical tab +\\ U+005C backslash \' U+0027 single quote (valid escape only within rune literals) \" U+0022 double quote (valid escape only within string literals) @@ -4329,12 +4329,16 @@ a run-time panic occurs. 
     s := make([]byte, 2, 4)
 s0 := (*[0]byte)(s)      // s0 != nil
+s1 := (*[1]byte)(s[1:])  // &s1[0] == &s[1]
 s2 := (*[2]byte)(s)      // &s2[0] == &s[0]
 s4 := (*[4]byte)(s)      // panics: len([4]byte) > len(s)
 
 var t []string
 t0 := (*[0]string)(t)    // t0 == nil
-t1 := (*[1]string)(t)    // panics: len([1]string) > len(s)
+t1 := (*[1]string)(t)    // panics: len([1]string) > len(t)
+
+u := make([]byte, 0)
+u0 = (*[0]byte)(u)       // u0 != nil

    Constant expressions

    @@ -4670,7 +4674,7 @@ The following built-in functions are not permitted in statement context: 
     append cap complex imag len make new real
-unsafe.Alignof unsafe.Offsetof unsafe.Sizeof
+unsafe.Add unsafe.Alignof unsafe.Offsetof unsafe.Sizeof unsafe.Slice
 
    @@ -4909,7 +4913,7 @@ if x := f(); x < y {
 
 
    
 "Switch" statements provide multi-way execution.
-An expression or type specifier is compared to the "cases"
+An expression or type is compared to the "cases"
 inside the "switch" to determine which branch
 to execute.
 
    
@@ -5020,7 +5024,7 @@ floating point, or string constants in case expressions.
 A type switch compares types rather than values. It is otherwise similar
 to an expression switch. It is marked by a special switch expression that
 has the form of a type assertion
-using the reserved word type rather than an actual type:
+using the keyword type rather than an actual type:
 
    
 
 
    @@ -6782,18 +6786,26 @@ The rules for valid uses of Pointer
 The function Slice returns a slice whose underlying array starts at ptr
-and whose length and capacity are len:
+and whose length and capacity are len.
+Slice(ptr, len) is equivalent to
 
    
 
 
     (*[len]ArbitraryType)(unsafe.Pointer(ptr))[:]
 
    
 
+
    
+except that, as a special case, if ptr
+is nil and len is zero,
+Slice returns nil.
+
    
+
 
    
 The len argument must be of integer type or an untyped constant.
 A constant len argument must be non-negative and representable by a value of type int;
 if it is an untyped constant it is given type int.
-If ptr is nil or len is negative at run time,
+At run time, if len is negative,
+or if ptr is nil and len is not zero,
 a run-time panic occurs.
 
    
 
diff --git a/lib/time/README b/lib/time/README
index aab4daa7e2d..0de06df13b9 100644
--- a/lib/time/README
+++ b/lib/time/README
@@ -4,7 +4,7 @@ The IANA asserts that the database is in the public domain.
 
 For more information, see
 https://www.iana.org/time-zones
-ftp://ftp.iana.org/tz/code/tz-link.htm
-http://tools.ietf.org/html/rfc6557
+ftp://ftp.iana.org/tz/code/tz-link.html
+https://datatracker.ietf.org/doc/html/rfc6557
 
 To rebuild the archive, read and run update.bash.
diff --git a/misc/android/go_android_exec.go b/misc/android/go_android_exec.go
index 3af2bee5839..168ebe88a22 100644
--- a/misc/android/go_android_exec.go
+++ b/misc/android/go_android_exec.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 // This program can be used as go_android_GOARCH_exec by the Go tool.
diff --git a/misc/cgo/errors/errors_test.go b/misc/cgo/errors/errors_test.go
index a077b594786..68a30a44fe4 100644
--- a/misc/cgo/errors/errors_test.go
+++ b/misc/cgo/errors/errors_test.go
@@ -40,7 +40,8 @@ func check(t *testing.T, file string) {
 			if len(frags) == 1 {
 				continue
 			}
-			re, err := regexp.Compile(string(frags[1]))
+			frag := fmt.Sprintf(":%d:.*%s", i+1, frags[1])
+			re, err := regexp.Compile(frag)
 			if err != nil {
 				t.Errorf("Invalid regexp after `ERROR HERE: `: %#q", frags[1])
 				continue
diff --git a/misc/cgo/errors/testdata/err2.go b/misc/cgo/errors/testdata/err2.go
index 1d22401aee5..aa941584c3c 100644
--- a/misc/cgo/errors/testdata/err2.go
+++ b/misc/cgo/errors/testdata/err2.go
@@ -40,15 +40,15 @@ func main() {
 	C.foop = x // ERROR HERE
 
 	// issue 13129: used to output error about C.unsignedshort with CC=clang
-	var x C.ushort
-	x = int(0) // ERROR HERE: C\.ushort
+	var x1 C.ushort
+	x1 = int(0) // ERROR HERE: C\.ushort
 
 	// issue 13423
 	_ = C.fopen() // ERROR HERE
 
 	// issue 13467
-	var x rune = '✈'
-	var _ rune = C.transform(x) // ERROR HERE: C\.int
+	var x2 rune = '✈'
+	var _ rune = C.transform(x2) // ERROR HERE: C\.int
 
 	// issue 13635: used to output error about C.unsignedchar.
 	// This test tests all such types.
@@ -91,10 +91,18 @@ func main() {
 
 	// issue 26745
 	_ = func(i int) int {
-		return C.i + 1 // ERROR HERE: :13
+		// typecheck reports at column 14 ('+'), but types2 reports at
+		// column 10 ('C').
+		// TODO(mdempsky): Investigate why, and see if types2 can be
+		// updated to match typecheck behavior.
+		return C.i + 1 // ERROR HERE: \b(10|14)\b
 	}
 	_ = func(i int) {
-		C.fi(i) // ERROR HERE: :6
+		// typecheck reports at column 7 ('('), but types2 reports at
+		// column 8 ('i'). The types2 position is more correct, but
+		// updating typecheck here is fundamentally challenging because of
+		// IR limitations.
+		C.fi(i) // ERROR HERE: \b(7|8)\b
 	}
 
 	C.fi = C.fi // ERROR HERE
diff --git a/misc/cgo/gmp/fib.go b/misc/cgo/gmp/fib.go
index f1091b1c54f..f453fcf1843 100644
--- a/misc/cgo/gmp/fib.go
+++ b/misc/cgo/gmp/fib.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 // Compute Fibonacci numbers with two goroutines
diff --git a/misc/cgo/gmp/pi.go b/misc/cgo/gmp/pi.go
index d5851e8e6bd..5ea034900a9 100644
--- a/misc/cgo/gmp/pi.go
+++ b/misc/cgo/gmp/pi.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/misc/cgo/test/cgo_thread_lock.go b/misc/cgo/test/cgo_thread_lock.go
index b1050685182..3b9ac845493 100644
--- a/misc/cgo/test/cgo_thread_lock.go
+++ b/misc/cgo/test/cgo_thread_lock.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && freebsd && openbsd
 // +build linux,freebsd,openbsd
 
 package cgotest
diff --git a/misc/cgo/test/cgo_unix_test.go b/misc/cgo/test/cgo_unix_test.go
index e3d59166498..a324503a22f 100644
--- a/misc/cgo/test/cgo_unix_test.go
+++ b/misc/cgo/test/cgo_unix_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 package cgotest
diff --git a/misc/cgo/test/issue1435.go b/misc/cgo/test/issue1435.go
index cf34ce8db6c..91db155c90b 100644
--- a/misc/cgo/test/issue1435.go
+++ b/misc/cgo/test/issue1435.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && cgo
 // +build linux,cgo
 
 package cgotest
@@ -9,6 +10,7 @@ package cgotest
 import (
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 	"syscall"
 	"testing"
@@ -105,11 +107,23 @@ func compareStatus(filter, expect string) error {
 				// "Pid:\t".
 			}
 			if strings.HasPrefix(line, filter) {
-				if line != expected {
-					return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc)
+				if line == expected {
+					foundAThread = true
+					break
 				}
-				foundAThread = true
-				break
+				if filter == "Groups:" && strings.HasPrefix(line, "Groups:\t") {
+					// https://github.com/golang/go/issues/46145
+					// Containers don't reliably output this line in sorted order so manually sort and compare that.
+					a := strings.Split(line[8:], " ")
+					sort.Strings(a)
+					got := strings.Join(a, " ")
+					if got == expected[8:] {
+						foundAThread = true
+						break
+					}
+
+				}
+				return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc)
 			}
 		}
 	}
diff --git a/misc/cgo/test/issue18146.go b/misc/cgo/test/issue18146.go
index f92d6c7f939..e50f9ae5301 100644
--- a/misc/cgo/test/issue18146.go
+++ b/misc/cgo/test/issue18146.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 // Issue 18146: pthread_create failure during syscall.Exec.
diff --git a/misc/cgo/test/issue21897.go b/misc/cgo/test/issue21897.go
index d13246bd84a..8f39252e688 100644
--- a/misc/cgo/test/issue21897.go
+++ b/misc/cgo/test/issue21897.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && cgo && !internal
 // +build darwin,cgo,!internal
 
 package cgotest
diff --git a/misc/cgo/test/issue21897b.go b/misc/cgo/test/issue21897b.go
index 08b5f4d808e..50aece35289 100644
--- a/misc/cgo/test/issue21897b.go
+++ b/misc/cgo/test/issue21897b.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !darwin || !cgo || internal
 // +build !darwin !cgo internal
 
 package cgotest
diff --git a/misc/cgo/test/issue4029.go b/misc/cgo/test/issue4029.go
index b2d131833a9..90ca08cbfb7 100644
--- a/misc/cgo/test/issue4029.go
+++ b/misc/cgo/test/issue4029.go
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !windows,!static
+//go:build !windows && !static && (!darwin || (!internal_pie && !arm64))
+// +build !windows
+// +build !static
 // +build !darwin !internal_pie,!arm64
 
 // Excluded in darwin internal linking PIE mode, as dynamic export is not
diff --git a/misc/cgo/test/issue4029w.go b/misc/cgo/test/issue4029w.go
index b969bdd0fe8..c2f59485e49 100644
--- a/misc/cgo/test/issue4029w.go
+++ b/misc/cgo/test/issue4029w.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows || static || (darwin && internal_pie) || (darwin && arm64)
 // +build windows static darwin,internal_pie darwin,arm64
 
 package cgotest
diff --git a/misc/cgo/test/issue6997_linux.go b/misc/cgo/test/issue6997_linux.go
index f19afb8b7ad..4acc8c1a070 100644
--- a/misc/cgo/test/issue6997_linux.go
+++ b/misc/cgo/test/issue6997_linux.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !android
 // +build !android
 
 // Test that pthread_cancel works as expected
diff --git a/misc/cgo/test/issue8517.go b/misc/cgo/test/issue8517.go
index 4e431df921d..7316ab0335d 100644
--- a/misc/cgo/test/issue8517.go
+++ b/misc/cgo/test/issue8517.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 package cgotest
diff --git a/misc/cgo/test/issue8694.go b/misc/cgo/test/issue8694.go
index 89be7ea0907..19071ce1595 100644
--- a/misc/cgo/test/issue8694.go
+++ b/misc/cgo/test/issue8694.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !android
 // +build !android
 
 package cgotest
diff --git a/misc/cgo/test/sigaltstack.go b/misc/cgo/test/sigaltstack.go
index 034cc4b3719..6b371897a73 100644
--- a/misc/cgo/test/sigaltstack.go
+++ b/misc/cgo/test/sigaltstack.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows && !android
 // +build !windows,!android
 
 // Test that the Go runtime still works if C code changes the signal stack.
diff --git a/misc/cgo/test/sigprocmask.go b/misc/cgo/test/sigprocmask.go
index e2b939f05e2..983734cc7b6 100644
--- a/misc/cgo/test/sigprocmask.go
+++ b/misc/cgo/test/sigprocmask.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 package cgotest
diff --git a/misc/cgo/test/test_unix.go b/misc/cgo/test/test_unix.go
index 4a234469dbc..831b9ca625a 100644
--- a/misc/cgo/test/test_unix.go
+++ b/misc/cgo/test/test_unix.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 package cgotest
diff --git a/misc/cgo/testcshared/cshared_test.go b/misc/cgo/testcshared/cshared_test.go
index 90d8c365e6d..19ad8c76a83 100644
--- a/misc/cgo/testcshared/cshared_test.go
+++ b/misc/cgo/testcshared/cshared_test.go
@@ -292,11 +292,60 @@ func createHeaders() error {
 		"-installsuffix", "testcshared",
 		"-o", libgoname,
 		filepath.Join(".", "libgo", "libgo.go")}
+	if GOOS == "windows" && strings.HasSuffix(args[6], ".a") {
+		args[6] = strings.TrimSuffix(args[6], ".a") + ".dll"
+	}
 	cmd = exec.Command(args[0], args[1:]...)
 	out, err = cmd.CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("command failed: %v\n%v\n%s\n", args, err, out)
 	}
+	if GOOS == "windows" {
+		// We can't simply pass -Wl,--out-implib, because this relies on having imports from multiple packages,
+		// which results in the linkers output implib getting overwritten at each step. So instead build the
+		// import library the traditional way, using a def file.
+		err = os.WriteFile("libgo.def",
+			[]byte("LIBRARY libgo.dll\nEXPORTS\n\tDidInitRun\n\tDidMainRun\n\tDivu\n\tFromPkg\n\t_cgo_dummy_export\n"),
+			0644)
+		if err != nil {
+			return fmt.Errorf("unable to write def file: %v", err)
+		}
+		out, err = exec.Command(cc[0], append(cc[1:], "-print-prog-name=dlltool")...).CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("unable to find dlltool path: %v\n%s\n", err, out)
+		}
+		args := []string{strings.TrimSpace(string(out)), "-D", args[6], "-l", libgoname, "-d", "libgo.def"}
+
+		// This is an unfortunate workaround for https://github.com/mstorsjo/llvm-mingw/issues/205 in which
+		// we basically reimplement the contents of the dlltool.sh wrapper: https://git.io/JZFlU
+		dlltoolContents, err := os.ReadFile(args[0])
+		if err != nil {
+			return fmt.Errorf("unable to read dlltool: %v\n", err)
+		}
+		if bytes.HasPrefix(dlltoolContents, []byte("#!/bin/sh")) && bytes.Contains(dlltoolContents, []byte("llvm-dlltool")) {
+			base, name := filepath.Split(args[0])
+			args[0] = filepath.Join(base, "llvm-dlltool")
+			var machine string
+			switch strings.SplitN(name, "-", 2)[0] {
+			case "i686":
+				machine = "i386"
+			case "x86_64":
+				machine = "i386:x86-64"
+			case "armv7":
+				machine = "arm"
+			case "aarch64":
+				machine = "arm64"
+			}
+			if len(machine) > 0 {
+				args = append(args, "-m", machine)
+			}
+		}
+
+		out, err = exec.Command(args[0], args[1:]...).CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("unable to run dlltool to create import library: %v\n%s\n", err, out)
+		}
+	}
 
 	if runtime.GOOS != GOOS && GOOS == "android" {
 		args = append(adbCmd(), "push", libgoname, fmt.Sprintf("%s/%s", androiddir, libgoname))
@@ -400,7 +449,7 @@ func main() {
 	defer f.Close()
 	section := f.Section(".edata")
 	if section == nil {
-		t.Fatalf(".edata section is not present")
+		t.Skip(".edata section is not present")
 	}
 
 	// TODO: deduplicate this struct from cmd/link/internal/ld/pe.go
@@ -749,7 +798,12 @@ func TestGo2C2Go(t *testing.T) {
 	defer os.RemoveAll(tmpdir)
 
 	lib := filepath.Join(tmpdir, "libtestgo2c2go."+libSuffix)
-	run(t, nil, "go", "build", "-buildmode=c-shared", "-o", lib, "./go2c2go/go")
+	var env []string
+	if GOOS == "windows" && strings.HasSuffix(lib, ".a") {
+		env = append(env, "CGO_LDFLAGS=-Wl,--out-implib,"+lib, "CGO_LDFLAGS_ALLOW=.*")
+		lib = strings.TrimSuffix(lib, ".a") + ".dll"
+	}
+	run(t, env, "go", "build", "-buildmode=c-shared", "-o", lib, "./go2c2go/go")
 
 	cgoCflags := os.Getenv("CGO_CFLAGS")
 	if cgoCflags != "" {
diff --git a/misc/cgo/testplugin/plugin_test.go b/misc/cgo/testplugin/plugin_test.go
index 28a8c669c07..9697dbf7a78 100644
--- a/misc/cgo/testplugin/plugin_test.go
+++ b/misc/cgo/testplugin/plugin_test.go
@@ -263,6 +263,17 @@ func TestIssue25756(t *testing.T) {
 	}
 }
 
+// Test with main using -buildmode=pie with plugin for issue #43228
+func TestIssue25756pie(t *testing.T) {
+	if os.Getenv("GO_BUILDER_NAME") == "darwin-arm64-11_0-toothrot" {
+		t.Skip("broken on darwin/arm64 builder in sharded mode; see issue 46239")
+	}
+
+	goCmd(t, "build", "-buildmode=plugin", "-o", "life.so", "./issue25756/plugin")
+	goCmd(t, "build", "-buildmode=pie", "-o", "issue25756pie.exe", "./issue25756/main.go")
+	run(t, "./issue25756pie.exe")
+}
+
 func TestMethod(t *testing.T) {
 	// Exported symbol's method must be live.
 	goCmd(t, "build", "-buildmode=plugin", "-o", "plugin.so", "./method/plugin.go")
diff --git a/misc/cgo/testsanitizers/msan_test.go b/misc/cgo/testsanitizers/msan_test.go
index 2a3494fbfc1..5ee9947a585 100644
--- a/misc/cgo/testsanitizers/msan_test.go
+++ b/misc/cgo/testsanitizers/msan_test.go
@@ -42,6 +42,7 @@ func TestMSAN(t *testing.T) {
 		{src: "msan5.go"},
 		{src: "msan6.go"},
 		{src: "msan7.go"},
+		{src: "msan8.go"},
 		{src: "msan_fail.go", wantErr: true},
 	}
 	for _, tc := range cases {
diff --git a/misc/cgo/testsanitizers/testdata/msan8.go b/misc/cgo/testsanitizers/testdata/msan8.go
new file mode 100644
index 00000000000..1cb5c5677fa
--- /dev/null
+++ b/misc/cgo/testsanitizers/testdata/msan8.go
@@ -0,0 +1,109 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+/*
+#include 
+#include 
+#include 
+
+#include 
+
+// cgoTracebackArg is the type of the argument passed to msanGoTraceback.
+struct cgoTracebackArg {
+	uintptr_t context;
+	uintptr_t sigContext;
+	uintptr_t* buf;
+	uintptr_t max;
+};
+
+// msanGoTraceback is registered as the cgo traceback function.
+// This will be called when a signal occurs.
+void msanGoTraceback(void* parg) {
+	struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
+        arg->buf[0] = 0;
+}
+
+// msanGoWait will be called with all registers undefined as far as
+// msan is concerned. It just waits for a signal.
+// Because the registers are msan-undefined, the signal handler will
+// be invoked with all registers msan-undefined.
+__attribute__((noinline))
+void msanGoWait(unsigned long a1, unsigned long a2, unsigned long a3, unsigned long a4, unsigned long a5, unsigned long a6) {
+	sigset_t mask;
+
+	sigemptyset(&mask);
+        sigsuspend(&mask);
+}
+
+// msanGoSignalThread is the thread ID of the msanGoLoop thread.
+static pthread_t msanGoSignalThread;
+
+// msanGoSignalThreadSet is used to record that msanGoSignalThread
+// has been initialized. This is accessed atomically.
+static int32_t msanGoSignalThreadSet;
+
+// uninit is explicitly poisoned, so that we can make all registers
+// undefined by calling msanGoWait.
+static unsigned long uninit;
+
+// msanGoLoop loops calling msanGoWait, with the arguments passed
+// such that msan thinks that they are undefined. msan permits
+// undefined values to be used as long as they are not used to
+// for conditionals or for memory access.
+void msanGoLoop() {
+	int i;
+
+	msanGoSignalThread = pthread_self();
+        __atomic_store_n(&msanGoSignalThreadSet, 1, __ATOMIC_SEQ_CST);
+
+	// Force uninit to be undefined for msan.
+	__msan_poison(&uninit, sizeof uninit);
+	for (i = 0; i < 100; i++) {
+		msanGoWait(uninit, uninit, uninit, uninit, uninit, uninit);
+        }
+}
+
+// msanGoReady returns whether msanGoSignalThread is set.
+int msanGoReady() {
+	return __atomic_load_n(&msanGoSignalThreadSet, __ATOMIC_SEQ_CST) != 0;
+}
+
+// msanGoSendSignal sends a signal to the msanGoLoop thread.
+void msanGoSendSignal() {
+	pthread_kill(msanGoSignalThread, SIGWINCH);
+}
+*/
+import "C"
+
+import (
+	"runtime"
+	"time"
+)
+
+func main() {
+	runtime.SetCgoTraceback(0, C.msanGoTraceback, nil, nil)
+
+	c := make(chan bool)
+	go func() {
+		defer func() { c <- true }()
+		C.msanGoLoop()
+	}()
+
+	for C.msanGoReady() == 0 {
+		time.Sleep(time.Microsecond)
+	}
+
+loop:
+	for {
+		select {
+		case <-c:
+			break loop
+		default:
+			C.msanGoSendSignal()
+			time.Sleep(time.Microsecond)
+		}
+	}
+}
diff --git a/misc/cgo/testso/noso_test.go b/misc/cgo/testso/noso_test.go
index c88aebfb02a..1014534d62c 100644
--- a/misc/cgo/testso/noso_test.go
+++ b/misc/cgo/testso/noso_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !cgo
 // +build !cgo
 
 package so_test
diff --git a/misc/cgo/testso/so_test.go b/misc/cgo/testso/so_test.go
index 2023c51f113..6d14e32dc6c 100644
--- a/misc/cgo/testso/so_test.go
+++ b/misc/cgo/testso/so_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
 // +build cgo
 
 package so_test
diff --git a/misc/cgo/testsovar/noso_test.go b/misc/cgo/testsovar/noso_test.go
index c88aebfb02a..1014534d62c 100644
--- a/misc/cgo/testsovar/noso_test.go
+++ b/misc/cgo/testsovar/noso_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !cgo
 // +build !cgo
 
 package so_test
diff --git a/misc/cgo/testsovar/so_test.go b/misc/cgo/testsovar/so_test.go
index 2023c51f113..6d14e32dc6c 100644
--- a/misc/cgo/testsovar/so_test.go
+++ b/misc/cgo/testsovar/so_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
 // +build cgo
 
 package so_test
diff --git a/misc/cgo/testtls/tls_test.go b/misc/cgo/testtls/tls_test.go
index 3076c2d5943..a3b67c00441 100644
--- a/misc/cgo/testtls/tls_test.go
+++ b/misc/cgo/testtls/tls_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 package cgotlstest
diff --git a/misc/ios/detect.go b/misc/ios/detect.go
index cde57238923..1cb8ae5ff71 100644
--- a/misc/ios/detect.go
+++ b/misc/ios/detect.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 // detect attempts to autodetect the correct
diff --git a/misc/reboot/experiment_toolid_test.go b/misc/reboot/experiment_toolid_test.go
index 4f40284d80f..87a828e32f7 100644
--- a/misc/reboot/experiment_toolid_test.go
+++ b/misc/reboot/experiment_toolid_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build explicit
 // +build explicit
 
 // Package experiment_toolid_test verifies that GOEXPERIMENT settings built
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
index 3e41e628ef9..231185a123e 100644
--- a/misc/wasm/wasm_exec.js
+++ b/misc/wasm/wasm_exec.js
@@ -401,6 +401,7 @@
 							storeValue(sp + 56, result);
 							this.mem.setUint8(sp + 64, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 56, err);
 							this.mem.setUint8(sp + 64, 0);
 						}
@@ -417,6 +418,7 @@
 							storeValue(sp + 40, result);
 							this.mem.setUint8(sp + 48, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 40, err);
 							this.mem.setUint8(sp + 48, 0);
 						}
@@ -433,6 +435,7 @@
 							storeValue(sp + 40, result);
 							this.mem.setUint8(sp + 48, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 40, err);
 							this.mem.setUint8(sp + 48, 0);
 						}
diff --git a/src/archive/zip/reader.go b/src/archive/zip/reader.go
index 808cf274cad..2d53f4c7231 100644
--- a/src/archive/zip/reader.go
+++ b/src/archive/zip/reader.go
@@ -96,7 +96,15 @@ func (z *Reader) init(r io.ReaderAt, size int64) error {
 		return err
 	}
 	z.r = r
-	z.File = make([]*File, 0, end.directoryRecords)
+	// Since the number of directory records is not validated, it is not
+	// safe to preallocate z.File without first checking that the specified
+	// number of files is reasonable, since a malformed archive may
+	// indicate it contains up to 1 << 128 - 1 files. Since each file has a
+	// header which will be _at least_ 30 bytes we can safely preallocate
+	// if (data size / 30) >= end.directoryRecords.
+	if (uint64(size)-end.directorySize)/30 >= end.directoryRecords {
+		z.File = make([]*File, 0, end.directoryRecords)
+	}
 	z.Comment = end.comment
 	rs := io.NewSectionReader(r, 0, size)
 	if _, err = rs.Seek(int64(end.directoryOffset), io.SeekStart); err != nil {
diff --git a/src/archive/zip/reader_test.go b/src/archive/zip/reader_test.go
index 35e681ec699..37dafe6c8e7 100644
--- a/src/archive/zip/reader_test.go
+++ b/src/archive/zip/reader_test.go
@@ -1325,3 +1325,62 @@ func TestReadDataDescriptor(t *testing.T) {
 		})
 	}
 }
+
+func TestCVE202133196(t *testing.T) {
+	// Archive that indicates it has 1 << 128 -1 files,
+	// this would previously cause a panic due to attempting
+	// to allocate a slice with 1 << 128 -1 elements.
+	data := []byte{
+		0x50, 0x4b, 0x03, 0x04, 0x14, 0x00, 0x08, 0x08,
+		0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x01, 0x02,
+		0x03, 0x62, 0x61, 0x65, 0x03, 0x04, 0x00, 0x00,
+		0xff, 0xff, 0x50, 0x4b, 0x07, 0x08, 0xbe, 0x20,
+		0x5c, 0x6c, 0x09, 0x00, 0x00, 0x00, 0x03, 0x00,
+		0x00, 0x00, 0x50, 0x4b, 0x01, 0x02, 0x14, 0x00,
+		0x14, 0x00, 0x08, 0x08, 0x08, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0xbe, 0x20, 0x5c, 0x6c, 0x09, 0x00,
+		0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x03, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x01, 0x02, 0x03, 0x50, 0x4b, 0x06, 0x06, 0x2c,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2d,
+		0x00, 0x2d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff,
+		0xff, 0xff, 0xff, 0x31, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x3a, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x50, 0x4b, 0x06, 0x07, 0x00,
+		0x00, 0x00, 0x00, 0x6b, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x50,
+		0x4b, 0x05, 0x06, 0x00, 0x00, 0x00, 0x00, 0xff,
+		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+		0xff, 0xff, 0xff, 0x00, 0x00,
+	}
+	_, err := NewReader(bytes.NewReader(data), int64(len(data)))
+	if err != ErrFormat {
+		t.Fatalf("unexpected error, got: %v, want: %v", err, ErrFormat)
+	}
+
+	// Also check that an archive containing a handful of empty
+	// files doesn't cause an issue
+	b := bytes.NewBuffer(nil)
+	w := NewWriter(b)
+	for i := 0; i < 5; i++ {
+		_, err := w.Create("")
+		if err != nil {
+			t.Fatalf("Writer.Create failed: %s", err)
+		}
+	}
+	if err := w.Close(); err != nil {
+		t.Fatalf("Writer.Close failed: %s", err)
+	}
+	r, err := NewReader(bytes.NewReader(b.Bytes()), int64(b.Len()))
+	if err != nil {
+		t.Fatalf("NewReader failed: %s", err)
+	}
+	if len(r.File) != 5 {
+		t.Errorf("Archive has unexpected number of files, got %d, want 5", len(r.File))
+	}
+}
diff --git a/src/cmd/asm/internal/asm/parse.go b/src/cmd/asm/internal/asm/parse.go
index ab48632a44b..4cddcf48a46 100644
--- a/src/cmd/asm/internal/asm/parse.go
+++ b/src/cmd/asm/internal/asm/parse.go
@@ -1003,7 +1003,8 @@ func (p *Parser) registerIndirect(a *obj.Addr, prefix rune) {
 				p.errorf("unimplemented two-register form")
 			}
 			a.Index = r1
-			if scale != 0 && p.arch.Family == sys.ARM64 {
+			if scale != 0 && scale != 1 && p.arch.Family == sys.ARM64 {
+				// Support (R1)(R2) (no scaling) and (R1)(R2*1).
 				p.errorf("arm64 doesn't support scaled register format")
 			} else {
 				a.Scale = int16(scale)
diff --git a/src/cmd/asm/internal/asm/testdata/arm64.s b/src/cmd/asm/internal/asm/testdata/arm64.s
index 1146c1a7898..d8a20edfc13 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64.s
@@ -89,7 +89,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	CMP	R1<<33, R2
 	CMP	R22.SXTX, RSP                    // ffe336eb
 	CMP	$0x22220000, RSP                 // CMP $572653568, RSP   // 5b44a4d2ff633beb
-	CMPW	$0x22220000, RSP                 // CMPW $572653568, RSP  // 5b44a452ff633b6b
+	CMPW	$0x22220000, RSP                 // CMPW $572653568, RSP  // 5b44a452ff433b6b
 	CCMN	MI, ZR, R1, $4	                 // e44341ba
 	// MADD Rn,Rm,Ra,Rd
 	MADD	R1, R2, R3, R4                   // 6408019b
@@ -377,6 +377,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	MOVD	$0x1000100010001000, RSP      // MOVD	$1152939097061330944, RSP   // ff8304b2
 	MOVW	$0x10001000, RSP              // MOVW	$268439552, RSP             // ff830432
 	ADDW	$0x10001000, R1               // ADDW	$268439552, R1              // fb83043221001b0b
+	ADDW	$0x22220000, RSP, R3          // ADDW	$572653568, RSP, R3         // 5b44a452e3433b0b
 
 // move a large constant to a Vd.
 	VMOVS	$0x80402010, V11                                      // VMOVS	$2151686160, V11
@@ -547,6 +548,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 // shifted or extended register offset.
 	MOVD	(R2)(R6.SXTW), R4               // 44c866f8
 	MOVD	(R3)(R6), R5                    // 656866f8
+	MOVD	(R3)(R6*1), R5                  // 656866f8
 	MOVD	(R2)(R6), R4                    // 446866f8
 	MOVWU	(R19)(R20<<2), R20              // 747a74b8
 	MOVD	(R2)(R6<<3), R4                 // 447866f8
@@ -579,6 +581,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	MOVB	R4, (R2)(R6.SXTX)               // 44e82638
 	MOVB	R8, (R3)(R9.UXTW)               // 68482938
 	MOVB	R10, (R5)(R8)                   // aa682838
+	MOVB	R10, (R5)(R8*1)                 // aa682838
 	MOVH	R11, (R2)(R7.SXTW<<1)           // 4bd82778
 	MOVH	R5, (R1)(R2<<1)                 // 25782278
 	MOVH	R7, (R2)(R5.SXTX<<1)            // 47f82578
diff --git a/src/cmd/asm/internal/asm/testdata/arm64error.s b/src/cmd/asm/internal/asm/testdata/arm64error.s
index 66fc9107594..cf57179e430 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64error.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64error.s
@@ -52,6 +52,16 @@ TEXT errors(SB),$0
 	NEGSW	R7@>2, R5                                        // ERROR "unsupported shift operator"
 	CINC	CS, R2, R3, R4                                   // ERROR "illegal combination"
 	CSEL	LT, R1, R2                                       // ERROR "illegal combination"
+	CINC	AL, R2, R3                                       // ERROR "invalid condition"
+	CINC	NV, R2, R3                                       // ERROR "invalid condition"
+	CINVW	AL, R2, R3                                       // ERROR "invalid condition"
+	CINV	NV, R2, R3                                       // ERROR "invalid condition"
+	CNEG	AL, R2, R3                                       // ERROR "invalid condition"
+	CNEGW	NV, R2, R3                                       // ERROR "invalid condition"
+	CSET	AL, R2                                           // ERROR "invalid condition"
+	CSET	NV, R2                                           // ERROR "invalid condition"
+	CSETMW	AL, R2                                           // ERROR "invalid condition"
+	CSETM	NV, R2                                           // ERROR "invalid condition"
 	LDP.P	8(R2), (R2, R3)                                  // ERROR "constrained unpredictable behavior"
 	LDP.W	8(R3), (R2, R3)                                  // ERROR "constrained unpredictable behavior"
 	LDP	(R1), (R2, R2)                                   // ERROR "constrained unpredictable behavior"
diff --git a/src/cmd/asm/internal/asm/testdata/ppc64.s b/src/cmd/asm/internal/asm/testdata/ppc64.s
index 1bd4b1e1c89..b6c0aa5035c 100644
--- a/src/cmd/asm/internal/asm/testdata/ppc64.s
+++ b/src/cmd/asm/internal/asm/testdata/ppc64.s
@@ -41,8 +41,8 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	MOVDBR (R3)(R4), R5             // 7ca41c28
 	MOVWBR (R3)(R4), R5             // 7ca41c2c
 	MOVHBR (R3)(R4), R5             // 7ca41e2c
-	MOVD $foo+4009806848(FP), R5    // 3fe1ef0138bfcc20
-	MOVD $foo(SB), R5               // 3fe0000038bf0000
+	MOVD $foo+4009806848(FP), R5    // 3ca1ef0138a5cc20
+	MOVD $foo(SB), R5               // 3ca0000038a50000
 
 	MOVDU 8(R3), R4                 // e8830009
 	MOVDU (R3)(R4), R5              // 7ca4186a
diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go
index ae61725bc75..a73e998877a 100644
--- a/src/cmd/cgo/gcc.go
+++ b/src/cmd/cgo/gcc.go
@@ -1638,6 +1638,8 @@ func (p *Package) gccCmd() []string {
 		c = append(c, "-maix64")
 		c = append(c, "-mcmodel=large")
 	}
+	// disable LTO so we get an object whose symbols we can read
+	c = append(c, "-fno-lto")
 	c = append(c, "-") //read input from standard input
 	return c
 }
diff --git a/src/cmd/cgo/main.go b/src/cmd/cgo/main.go
index 03a662e689d..c6a0c525e64 100644
--- a/src/cmd/cgo/main.go
+++ b/src/cmd/cgo/main.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Cgo; see gmp.go for an overview.
+// Cgo; see doc.go for an overview.
 
 // TODO(rsc):
 //	Emit correct line number annotations.
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index 8c31d5b7941..94152f4278c 100644
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -168,8 +168,18 @@ func (p *Package) writeDefs() {
 			if *gccgo {
 				fmt.Fprintf(fc, "extern byte *%s;\n", n.C)
 			} else {
-				fmt.Fprintf(fm, "extern char %s[];\n", n.C)
-				fmt.Fprintf(fm, "void *_cgohack_%s = %s;\n\n", n.C, n.C)
+				// Force a reference to all symbols so that
+				// the external linker will add DT_NEEDED
+				// entries as needed on ELF systems.
+				// Treat function variables differently
+				// to avoid type confict errors from LTO
+				// (Link Time Optimization).
+				if n.Kind == "fpvar" {
+					fmt.Fprintf(fm, "extern void %s();\n", n.C)
+				} else {
+					fmt.Fprintf(fm, "extern char %s[];\n", n.C)
+					fmt.Fprintf(fm, "void *_cgohack_%s = %s;\n\n", n.C, n.C)
+				}
 				fmt.Fprintf(fgo2, "//go:linkname __cgo_%s %s\n", n.C, n.C)
 				fmt.Fprintf(fgo2, "//go:cgo_import_static %s\n", n.C)
 				fmt.Fprintf(fgo2, "var __cgo_%s byte\n", n.C)
@@ -1042,7 +1052,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
 		// This unpacks the argument struct above and calls the Go function.
 		fmt.Fprintf(fgo2, "func _cgoexp%s_%s(a *%s) {\n", cPrefix, exp.ExpName, gotype)
 
-		fmt.Fprintf(fm, "int _cgoexp%s_%s;\n", cPrefix, exp.ExpName)
+		fmt.Fprintf(fm, "void _cgoexp%s_%s(void* p){}\n", cPrefix, exp.ExpName)
 
 		if gccResult != "void" {
 			// Write results back to frame.
diff --git a/src/cmd/compile/abi-internal.md b/src/cmd/compile/abi-internal.md
index f901e707be3..3619aea4aa2 100644
--- a/src/cmd/compile/abi-internal.md
+++ b/src/cmd/compile/abi-internal.md
@@ -233,7 +233,7 @@ stack frame is laid out in the following sequence:
     r1.x    uintptr
     r1.y    [2]uintptr
     a1Spill uint8
-    a2Spill uint8
+    a3Spill uint8
     _       [6]uint8  // alignment padding
 
 In the stack frame, only the `a2` field is initialized on entry; the
@@ -402,7 +402,7 @@ without corrupting arguments or results.
 Special-purpose registers are as follows:
 
 | Register | Call meaning | Return meaning | Body meaning |
-| --- | --- | --- |
+| --- | --- | --- | --- |
 | RSP | Stack pointer | Same | Same |
 | RBP | Frame pointer | Same | Same |
 | RDX | Closure context pointer | Scratch | Scratch |
@@ -505,6 +505,128 @@ control bits specified by the ELF AMD64 ABI.
 
 The x87 floating-point control word is not used by Go on amd64.
 
+### arm64 architecture
+
+The arm64 architecture uses R0 – R15 for integer arguments and results.
+
+It uses F0 – F15 for floating-point arguments and results.
+
+*Rationale*: 16 integer registers and 16 floating-point registers are
+more than enough for passing arguments and results for practically all
+functions (see Appendix). While there are more registers available,
+using more registers provides little benefit. Additionally, it will add
+overhead on code paths where the number of arguments are not statically
+known (e.g. reflect call), and will consume more stack space when there
+is only limited stack space available to fit in the nosplit limit.
+
+Registers R16 and R17 are permanent scratch registers. They are also
+used as scratch registers by the linker (Go linker and external
+linker) in trampolines.
+
+Register R18 is reserved and never used. It is reserved for the OS
+on some platforms (e.g. macOS).
+
+Registers R19 – R25 are permanent scratch registers. In addition,
+R27 is a permanent scratch register used by the assembler when
+expanding instructions.
+
+Floating-point registers F16 – F31 are also permanent scratch
+registers.
+
+Special-purpose registers are as follows:
+
+| Register | Call meaning | Return meaning | Body meaning |
+| --- | --- | --- | --- |
+| RSP | Stack pointer | Same | Same |
+| R30 | Link register | Same | Scratch (non-leaf functions) |
+| R29 | Frame pointer | Same | Same |
+| R28 | Current goroutine | Same | Same |
+| R27 | Scratch | Scratch | Scratch |
+| R26 | Closure context pointer | Scratch | Scratch |
+| R18 | Reserved (not used) | Same | Same |
+| ZR  | Zero value | Same | Same |
+
+*Rationale*: These register meanings are compatible with Go’s
+stack-based calling convention.
+
+*Rationale*: The link register, R30, holds the function return
+address at the function entry. For functions that have frames
+(including most non-leaf functions), R30 is saved to stack in the
+function prologue and restored in the epilogue. Within the function
+body, R30 can be used as a scratch register.
+
+*Implementation note*: Registers with fixed meaning at calls but not
+in function bodies must be initialized by "injected" calls such as
+signal-based panics.
+
+#### Stack layout
+
+The stack pointer, RSP, grows down and is always aligned to 16 bytes.
+
+*Rationale*: The arm64 architecture requires the stack pointer to be
+16-byte aligned.
+
+A function's stack frame, after the frame is created, is laid out as
+follows:
+
+    +------------------------------+
+    | ... locals ...               |
+    | ... outgoing arguments ...   |
+    | return PC                    | ← RSP points to
+    | frame pointer on entry       |
+    +------------------------------+ ↓ lower addresses
+
+The "return PC" is loaded to the link register, R30, as part of the
+arm64 `CALL` operation.
+
+On entry, a function subtracts from RSP to open its stack frame, and
+saves the values of R30 and R29 at the bottom of the frame.
+Specifically, R30 is saved at 0(RSP) and R29 is saved at -8(RSP),
+after RSP is updated.
+
+A leaf function that does not require any stack space may omit the
+saved R30 and R29.
+
+The Go ABI's use of R29 as a frame pointer register is compatible with
+arm64 architecture requirement so that Go can inter-operate with platform
+debuggers and profilers.
+
+This stack layout is used by both register-based (ABIInternal) and
+stack-based (ABI0) calling conventions.
+
+#### Flags
+
+The arithmetic status flags (NZCV) are treated like scratch registers
+and not preserved across calls.
+All other bits in PSTATE are system flags and are not modified by Go.
+
+The floating-point status register (FPSR) is treated like scratch
+registers and not preserved across calls.
+
+At calls, the floating-point control register (FPCR) bits are always
+set as follows:
+
+| Flag | Bit | Value | Meaning |
+| --- | --- | --- | --- |
+| DN  | 25 | 0 | Propagate NaN operands |
+| FZ  | 24 | 0 | Do not flush to zero |
+| RC  | 23/22 | 0 (RN) | Round to nearest, choose even if tied |
+| IDE | 15 | 0 | Denormal operations trap disabled |
+| IXE | 12 | 0 | Inexact trap disabled |
+| UFE | 11 | 0 | Underflow trap disabled |
+| OFE | 10 | 0 | Overflow trap disabled |
+| DZE | 9 | 0 | Divide-by-zero trap disabled |
+| IOE | 8 | 0 | Invalid operations trap disabled |
+| NEP | 2 | 0 | Scalar operations do not affect higher elements in vector registers |
+| AH  | 1 | 0 | No alternate handling of de-normal inputs |
+| FIZ | 0 | 0 | Do not zero de-normals |
+
+*Rationale*: Having a fixed FPCR control configuration allows Go
+functions to use floating-point and vector (SIMD) operations without
+modifying or saving the FPCR.
+Functions are allowed to modify it between calls (as long as they
+restore it), but as of this writing Go code never does.
+
 ## Future directions
 
 ### Spill path improvements
diff --git a/src/cmd/compile/internal/abi/abiutils.go b/src/cmd/compile/internal/abi/abiutils.go
index cb8e9d7b0fe..d657ddc867b 100644
--- a/src/cmd/compile/internal/abi/abiutils.go
+++ b/src/cmd/compile/internal/abi/abiutils.go
@@ -446,35 +446,20 @@ func (config *ABIConfig) ABIAnalyze(t *types.Type, setNname bool) *ABIParamResul
 	return result
 }
 
-// parameterUpdateMu protects the Offset field of function/method parameters (a subset of structure Fields)
-var parameterUpdateMu sync.Mutex
-
-// FieldOffsetOf returns a concurency-safe version of f.Offset
-func FieldOffsetOf(f *types.Field) int64 {
-	parameterUpdateMu.Lock()
-	defer parameterUpdateMu.Unlock()
-	return f.Offset
-}
-
 func (config *ABIConfig) updateOffset(result *ABIParamResultInfo, f *types.Field, a ABIParamAssignment, isReturn, setNname bool) {
 	// Everything except return values in registers has either a frame home (if not in a register) or a frame spill location.
 	if !isReturn || len(a.Registers) == 0 {
 		// The type frame offset DOES NOT show effects of minimum frame size.
 		// Getting this wrong breaks stackmaps, see liveness/plive.go:WriteFuncMap and typebits/typebits.go:Set
-		parameterUpdateMu.Lock()
-		defer parameterUpdateMu.Unlock()
 		off := a.FrameOffset(result)
 		fOffset := f.Offset
 		if fOffset == types.BOGUS_FUNARG_OFFSET {
-			// Set the Offset the first time. After that, we may recompute it, but it should never change.
-			f.Offset = off
-			if f.Nname != nil {
-				// always set it in this case.
+			if setNname && f.Nname != nil {
 				f.Nname.(*ir.Name).SetFrameOffset(off)
 				f.Nname.(*ir.Name).SetIsOutputParamInRegisters(false)
 			}
-		} else if fOffset != off {
-			base.Fatalf("offset for %s at %s changed from %d to %d", f.Sym.Name, base.FmtPos(f.Pos), fOffset, off)
+		} else {
+			base.Fatalf("field offset for %s at %s has been set to %d", f.Sym.Name, base.FmtPos(f.Pos), fOffset)
 		}
 	} else {
 		if setNname && f.Nname != nil {
diff --git a/src/cmd/compile/internal/amd64/galign.go b/src/cmd/compile/internal/amd64/galign.go
index 2785aa03368..ca44263afc4 100644
--- a/src/cmd/compile/internal/amd64/galign.go
+++ b/src/cmd/compile/internal/amd64/galign.go
@@ -18,11 +18,10 @@ func Init(arch *ssagen.ArchInfo) {
 
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue
 	arch.SSAGenBlock = ssaGenBlock
-	arch.LoadRegResults = loadRegResults
+	arch.LoadRegResult = loadRegResult
 	arch.SpillArgReg = spillArgReg
 }
diff --git a/src/cmd/compile/internal/amd64/ggen.go b/src/cmd/compile/internal/amd64/ggen.go
index 1484ad5404b..b8dce81a92d 100644
--- a/src/cmd/compile/internal/amd64/ggen.go
+++ b/src/cmd/compile/internal/amd64/ggen.go
@@ -57,7 +57,6 @@ func dzDI(b int64) int64 {
 func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, state *uint32) *obj.Prog {
 	const (
 		r13 = 1 << iota // if R13 is already zeroed.
-		x15             // if X15 is already zeroed. Note: in new ABI, X15 is always zero.
 	)
 
 	if cnt == 0 {
@@ -85,11 +84,6 @@ func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, state *uint32) *obj.
 		}
 		p = pp.Append(p, x86.AMOVQ, obj.TYPE_REG, x86.REG_R13, 0, obj.TYPE_MEM, x86.REG_SP, off)
 	} else if !isPlan9 && cnt <= int64(8*types.RegSize) {
-		if !buildcfg.Experiment.RegabiG && *state&x15 == 0 {
-			p = pp.Append(p, x86.AXORPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_REG, x86.REG_X15, 0)
-			*state |= x15
-		}
-
 		for i := int64(0); i < cnt/16; i++ {
 			p = pp.Append(p, x86.AMOVUPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_MEM, x86.REG_SP, off+i*16)
 		}
@@ -98,10 +92,6 @@ func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, state *uint32) *obj.
 			p = pp.Append(p, x86.AMOVUPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_MEM, x86.REG_SP, off+cnt-int64(16))
 		}
 	} else if !isPlan9 && (cnt <= int64(128*types.RegSize)) {
-		if !buildcfg.Experiment.RegabiG && *state&x15 == 0 {
-			p = pp.Append(p, x86.AXORPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_REG, x86.REG_X15, 0)
-			*state |= x15
-		}
 		// Save DI to r12. With the amd64 Go register abi, DI can contain
 		// an incoming parameter, whereas R12 is always scratch.
 		p = pp.Append(p, x86.AMOVQ, obj.TYPE_REG, x86.REG_DI, 0, obj.TYPE_REG, x86.REG_R12, 0)
diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index ca5f36e7759..30dba057d01 100644
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -823,7 +823,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Reg = v.Args[0].Reg()
 		ssagen.AddAux2(&p.To, v, sc.Off64())
 	case ssa.OpAMD64MOVOstorezero:
-		if !buildcfg.Experiment.RegabiG || s.ABI != obj.ABIInternal {
+		if s.ABI != obj.ABIInternal {
 			// zero X15 manually
 			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
 		}
@@ -914,7 +914,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg()
 	case ssa.OpAMD64DUFFZERO:
-		if !buildcfg.Experiment.RegabiG || s.ABI != obj.ABIInternal {
+		if s.ABI != obj.ABIInternal {
 			// zero X15 manually
 			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
 		}
@@ -997,22 +997,26 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		// Closure pointer is DX.
 		ssagen.CheckLoweredGetClosurePtr(v)
 	case ssa.OpAMD64LoweredGetG:
-		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABIInternal {
+		if s.ABI == obj.ABIInternal {
 			v.Fatalf("LoweredGetG should not appear in ABIInternal")
 		}
 		r := v.Reg()
 		getgFromTLS(s, r)
 	case ssa.OpAMD64CALLstatic:
-		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
+		if s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
 		s.Call(v)
-		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
+		if s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
@@ -1304,9 +1308,11 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 	case ssa.BlockRet:
 		s.Prog(obj.ARET)
 	case ssa.BlockRetJmp:
-		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
+		if s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
@@ -1348,20 +1354,15 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 	}
 }
 
-func loadRegResults(s *ssagen.State, f *ssa.Func) {
-	for _, o := range f.OwnAux.ABIInfo().OutParams() {
-		n := o.Name.(*ir.Name)
-		rts, offs := o.RegisterTypesAndOffsets()
-		for i := range o.Registers {
-			p := s.Prog(loadByType(rts[i]))
-			p.From.Type = obj.TYPE_MEM
-			p.From.Name = obj.NAME_AUTO
-			p.From.Sym = n.Linksym()
-			p.From.Offset = n.FrameOffset() + offs[i]
-			p.To.Type = obj.TYPE_REG
-			p.To.Reg = ssa.ObjRegForAbiReg(o.Registers[i], f.Config)
-		}
-	}
+func loadRegResult(s *ssagen.State, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
+	p := s.Prog(loadByType(t))
+	p.From.Type = obj.TYPE_MEM
+	p.From.Name = obj.NAME_AUTO
+	p.From.Sym = n.Linksym()
+	p.From.Offset = n.FrameOffset() + off
+	p.To.Type = obj.TYPE_REG
+	p.To.Reg = reg
+	return p
 }
 
 func spillArgReg(pp *objw.Progs, p *obj.Prog, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
diff --git a/src/cmd/compile/internal/arm/galign.go b/src/cmd/compile/internal/arm/galign.go
index d68500280d0..23e52bacbf2 100644
--- a/src/cmd/compile/internal/arm/galign.go
+++ b/src/cmd/compile/internal/arm/galign.go
@@ -18,7 +18,6 @@ func Init(arch *ssagen.ArchInfo) {
 	arch.SoftFloat = buildcfg.GOARM == 5
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *ssagen.State, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue
diff --git a/src/cmd/compile/internal/arm64/galign.go b/src/cmd/compile/internal/arm64/galign.go
index d3db37e16f4..3ebd860de8f 100644
--- a/src/cmd/compile/internal/arm64/galign.go
+++ b/src/cmd/compile/internal/arm64/galign.go
@@ -18,9 +18,10 @@ func Init(arch *ssagen.ArchInfo) {
 	arch.PadFrame = padframe
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *ssagen.State, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue
 	arch.SSAGenBlock = ssaGenBlock
+	arch.LoadRegResult = loadRegResult
+	arch.SpillArgReg = spillArgReg
 }
diff --git a/src/cmd/compile/internal/arm64/ssa.go b/src/cmd/compile/internal/arm64/ssa.go
index 0c997bc4b3e..c3319f94912 100644
--- a/src/cmd/compile/internal/arm64/ssa.go
+++ b/src/cmd/compile/internal/arm64/ssa.go
@@ -10,6 +10,7 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/logopt"
+	"cmd/compile/internal/objw"
 	"cmd/compile/internal/ssa"
 	"cmd/compile/internal/ssagen"
 	"cmd/compile/internal/types"
@@ -161,6 +162,18 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[0].Reg()
 		ssagen.AddrAuto(&p.To, v)
+	case ssa.OpArgIntReg, ssa.OpArgFloatReg:
+		// The assembler needs to wrap the entry safepoint/stack growth code with spill/unspill
+		// The loop only runs once.
+		for _, a := range v.Block.Func.RegArgs {
+			// Pass the spill/unspill information along to the assembler, offset by size of
+			// the saved LR slot.
+			addr := ssagen.SpillSlotAddr(a, arm64.REGSP, base.Ctxt.FixedFrameSize())
+			s.FuncInfo().AddSpill(
+				obj.RegSpill{Reg: a.Reg, Addr: addr, Unspill: loadByType(a.Type), Spill: storeByType(a.Type)})
+		}
+		v.Block.Func.RegArgs = nil
+		ssagen.CheckArgReg(v)
 	case ssa.OpARM64ADD,
 		ssa.OpARM64SUB,
 		ssa.OpARM64AND,
@@ -1101,8 +1114,34 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		v.Fatalf("FlagConstant op should never make it to codegen %v", v.LongString())
 	case ssa.OpARM64InvertFlags:
 		v.Fatalf("InvertFlags should never make it to codegen %v", v.LongString())
-	case ssa.OpClobber, ssa.OpClobberReg:
-		// TODO: implement for clobberdead experiment. Nop is ok for now.
+	case ssa.OpClobber:
+		// MOVW	$0xdeaddead, REGTMP
+		// MOVW	REGTMP, (slot)
+		// MOVW	REGTMP, 4(slot)
+		p := s.Prog(arm64.AMOVW)
+		p.From.Type = obj.TYPE_CONST
+		p.From.Offset = 0xdeaddead
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = arm64.REGTMP
+		p = s.Prog(arm64.AMOVW)
+		p.From.Type = obj.TYPE_REG
+		p.From.Reg = arm64.REGTMP
+		p.To.Type = obj.TYPE_MEM
+		p.To.Reg = arm64.REGSP
+		ssagen.AddAux(&p.To, v)
+		p = s.Prog(arm64.AMOVW)
+		p.From.Type = obj.TYPE_REG
+		p.From.Reg = arm64.REGTMP
+		p.To.Type = obj.TYPE_MEM
+		p.To.Reg = arm64.REGSP
+		ssagen.AddAux2(&p.To, v, v.AuxInt+4)
+	case ssa.OpClobberReg:
+		x := uint64(0xdeaddeaddeaddead)
+		p := s.Prog(arm64.AMOVD)
+		p.From.Type = obj.TYPE_CONST
+		p.From.Offset = int64(x)
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = v.Reg()
 	default:
 		v.Fatalf("genValue not implemented: %s", v.LongString())
 	}
@@ -1266,3 +1305,22 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 		b.Fatalf("branch not implemented: %s", b.LongString())
 	}
 }
+
+func loadRegResult(s *ssagen.State, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
+	p := s.Prog(loadByType(t))
+	p.From.Type = obj.TYPE_MEM
+	p.From.Name = obj.NAME_AUTO
+	p.From.Sym = n.Linksym()
+	p.From.Offset = n.FrameOffset() + off
+	p.To.Type = obj.TYPE_REG
+	p.To.Reg = reg
+	return p
+}
+
+func spillArgReg(pp *objw.Progs, p *obj.Prog, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
+	p = pp.Append(p, storeByType(t), obj.TYPE_REG, reg, 0, obj.TYPE_MEM, 0, n.FrameOffset()+off)
+	p.To.Name = obj.NAME_PARAM
+	p.To.Sym = n.Linksym()
+	p.Pos = p.Pos.WithNotStmt()
+	return p
+}
diff --git a/src/cmd/compile/internal/base/bootstrap_false.go b/src/cmd/compile/internal/base/bootstrap_false.go
new file mode 100644
index 00000000000..c77fcd73081
--- /dev/null
+++ b/src/cmd/compile/internal/base/bootstrap_false.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !compiler_bootstrap
+// +build !compiler_bootstrap
+
+package base
+
+// CompilerBootstrap reports whether the current compiler binary was
+// built with -tags=compiler_bootstrap.
+const CompilerBootstrap = false
diff --git a/src/cmd/compile/internal/base/bootstrap_true.go b/src/cmd/compile/internal/base/bootstrap_true.go
new file mode 100644
index 00000000000..1eb58b2f9dc
--- /dev/null
+++ b/src/cmd/compile/internal/base/bootstrap_true.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build compiler_bootstrap
+// +build compiler_bootstrap
+
+package base
+
+// CompilerBootstrap reports whether the current compiler binary was
+// built with -tags=compiler_bootstrap.
+const CompilerBootstrap = true
diff --git a/src/cmd/compile/internal/base/debug.go b/src/cmd/compile/internal/base/debug.go
index 71712ab1a56..e2245e1c26e 100644
--- a/src/cmd/compile/internal/base/debug.go
+++ b/src/cmd/compile/internal/base/debug.go
@@ -44,8 +44,11 @@ type DebugFlags struct {
 	Panic                int    `help:"show all compiler panics"`
 	Slice                int    `help:"print information about slice compilation"`
 	SoftFloat            int    `help:"force compiler to emit soft-float code"`
+	SyncFrames           int    `help:"how many writer stack frames to include at sync points in unified export data"`
 	TypeAssert           int    `help:"print information about type assertion inlining"`
 	TypecheckInl         int    `help:"eager typechecking of inline function bodies"`
+	Unified              int    `help:"enable unified IR construction"`
+	UnifiedQuirks        int    `help:"enable unified IR construction's quirks mode"`
 	WB                   int    `help:"print information about write barriers"`
 	ABIWrap              int    `help:"print information about ABI wrapper generation"`
 
diff --git a/src/cmd/compile/internal/base/flag.go b/src/cmd/compile/internal/base/flag.go
index 42c0c1b94b5..b8b205f4127 100644
--- a/src/cmd/compile/internal/base/flag.go
+++ b/src/cmd/compile/internal/base/flag.go
@@ -159,7 +159,11 @@ func ParseFlags() {
 	Flag.LinkShared = &Ctxt.Flag_linkshared
 	Flag.Shared = &Ctxt.Flag_shared
 	Flag.WB = true
+
 	Debug.InlFuncsWithClosures = 1
+	if buildcfg.Experiment.Unified {
+		Debug.Unified = 1
+	}
 
 	Debug.Checkptr = -1 // so we can tell whether it is set explicitly
 
diff --git a/src/cmd/compile/internal/typecheck/mapfile_mmap.go b/src/cmd/compile/internal/base/mapfile_mmap.go
similarity index 93%
rename from src/cmd/compile/internal/typecheck/mapfile_mmap.go
rename to src/cmd/compile/internal/base/mapfile_mmap.go
index 298b385bcb0..c1616db8e9d 100644
--- a/src/cmd/compile/internal/typecheck/mapfile_mmap.go
+++ b/src/cmd/compile/internal/base/mapfile_mmap.go
@@ -5,7 +5,7 @@
 //go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd
 // +build darwin dragonfly freebsd linux netbsd openbsd
 
-package typecheck
+package base
 
 import (
 	"os"
@@ -19,7 +19,7 @@ import (
 
 // mapFile returns length bytes from the file starting at the
 // specified offset as a string.
-func mapFile(f *os.File, offset, length int64) (string, error) {
+func MapFile(f *os.File, offset, length int64) (string, error) {
 	// POSIX mmap: "The implementation may require that off is a
 	// multiple of the page size."
 	x := offset & int64(os.Getpagesize()-1)
diff --git a/src/cmd/compile/internal/typecheck/mapfile_read.go b/src/cmd/compile/internal/base/mapfile_read.go
similarity index 85%
rename from src/cmd/compile/internal/typecheck/mapfile_read.go
rename to src/cmd/compile/internal/base/mapfile_read.go
index 9637ab97abe..01796a9bab7 100644
--- a/src/cmd/compile/internal/typecheck/mapfile_read.go
+++ b/src/cmd/compile/internal/base/mapfile_read.go
@@ -5,14 +5,14 @@
 //go:build !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd
 // +build !darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd
 
-package typecheck
+package base
 
 import (
 	"io"
 	"os"
 )
 
-func mapFile(f *os.File, offset, length int64) (string, error) {
+func MapFile(f *os.File, offset, length int64) (string, error) {
 	buf := make([]byte, length)
 	_, err := io.ReadFull(io.NewSectionReader(f, offset, length), buf)
 	if err != nil {
diff --git a/src/cmd/compile/internal/base/print.go b/src/cmd/compile/internal/base/print.go
index b095fd704da..4afe2eb9eea 100644
--- a/src/cmd/compile/internal/base/print.go
+++ b/src/cmd/compile/internal/base/print.go
@@ -233,6 +233,27 @@ func FatalfAt(pos src.XPos, format string, args ...interface{}) {
 	ErrorExit()
 }
 
+// Assert reports "assertion failed" with Fatalf, unless b is true.
+func Assert(b bool) {
+	if !b {
+		Fatalf("assertion failed")
+	}
+}
+
+// Assertf reports a fatal error with Fatalf, unless b is true.
+func Assertf(b bool, format string, args ...interface{}) {
+	if !b {
+		Fatalf(format, args...)
+	}
+}
+
+// AssertfAt reports a fatal error with FatalfAt, unless b is true.
+func AssertfAt(b bool, pos src.XPos, format string, args ...interface{}) {
+	if !b {
+		FatalfAt(pos, format, args...)
+	}
+}
+
 // hcrash crashes the compiler when -h is set, to find out where a message is generated.
 func hcrash() {
 	if Flag.LowerH != 0 {
diff --git a/src/cmd/compile/internal/dwarfgen/dwarf.go b/src/cmd/compile/internal/dwarfgen/dwarf.go
index 422c7e66c47..0e22b61bc3f 100644
--- a/src/cmd/compile/internal/dwarfgen/dwarf.go
+++ b/src/cmd/compile/internal/dwarfgen/dwarf.go
@@ -222,9 +222,64 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 		fnsym.Func().RecordAutoType(reflectdata.TypeLinksym(n.Type()))
 	}
 
+	// Sort decls and vars.
+	sortDeclsAndVars(fn, decls, vars)
+
 	return decls, vars
 }
 
+// sortDeclsAndVars sorts the decl and dwarf var lists according to
+// parameter declaration order, so as to insure that when a subprogram
+// DIE is emitted, its parameter children appear in declaration order.
+// Prior to the advent of the register ABI, sorting by frame offset
+// would achieve this; with the register we now need to go back to the
+// original function signature.
+func sortDeclsAndVars(fn *ir.Func, decls []*ir.Name, vars []*dwarf.Var) {
+	paramOrder := make(map[*ir.Name]int)
+	idx := 1
+	for _, selfn := range types.RecvsParamsResults {
+		fsl := selfn(fn.Type()).FieldSlice()
+		for _, f := range fsl {
+			if n, ok := f.Nname.(*ir.Name); ok {
+				paramOrder[n] = idx
+				idx++
+			}
+		}
+	}
+	sort.Stable(varsAndDecls{decls, vars, paramOrder})
+}
+
+type varsAndDecls struct {
+	decls      []*ir.Name
+	vars       []*dwarf.Var
+	paramOrder map[*ir.Name]int
+}
+
+func (v varsAndDecls) Len() int {
+	return len(v.decls)
+}
+
+func (v varsAndDecls) Less(i, j int) bool {
+	nameLT := func(ni, nj *ir.Name) bool {
+		oi, foundi := v.paramOrder[ni]
+		oj, foundj := v.paramOrder[nj]
+		if foundi {
+			if foundj {
+				return oi < oj
+			} else {
+				return true
+			}
+		}
+		return false
+	}
+	return nameLT(v.decls[i], v.decls[j])
+}
+
+func (v varsAndDecls) Swap(i, j int) {
+	v.vars[i], v.vars[j] = v.vars[j], v.vars[i]
+	v.decls[i], v.decls[j] = v.decls[j], v.decls[i]
+}
+
 // Given a function that was inlined at some point during the
 // compilation, return a sorted list of nodes corresponding to the
 // autos/locals in that function prior to inlining. If this is a
@@ -476,6 +531,14 @@ func RecordFlags(flags ...string) {
 		fmt.Fprintf(&cmd, " -%s=%v", f.Name, getter.Get())
 	}
 
+	// Adds flag to producer string singalling whether regabi is turned on or
+	// off.
+	// Once regabi is turned on across the board and the relative GOEXPERIMENT
+	// knobs no longer exist this code should be removed.
+	if buildcfg.Experiment.RegabiArgs {
+		cmd.Write([]byte(" regabi"))
+	}
+
 	if cmd.Len() == 0 {
 		return
 	}
diff --git a/src/cmd/compile/internal/escape/assign.go b/src/cmd/compile/internal/escape/assign.go
new file mode 100644
index 00000000000..80697bf37b3
--- /dev/null
+++ b/src/cmd/compile/internal/escape/assign.go
@@ -0,0 +1,120 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+)
+
+// addr evaluates an addressable expression n and returns a hole
+// that represents storing into the represented location.
+func (e *escape) addr(n ir.Node) hole {
+	if n == nil || ir.IsBlank(n) {
+		// Can happen in select case, range, maybe others.
+		return e.discardHole()
+	}
+
+	k := e.heapHole()
+
+	switch n.Op() {
+	default:
+		base.Fatalf("unexpected addr: %v", n)
+	case ir.ONAME:
+		n := n.(*ir.Name)
+		if n.Class == ir.PEXTERN {
+			break
+		}
+		k = e.oldLoc(n).asHole()
+	case ir.OLINKSYMOFFSET:
+		break
+	case ir.ODOT:
+		n := n.(*ir.SelectorExpr)
+		k = e.addr(n.X)
+	case ir.OINDEX:
+		n := n.(*ir.IndexExpr)
+		e.discard(n.Index)
+		if n.X.Type().IsArray() {
+			k = e.addr(n.X)
+		} else {
+			e.discard(n.X)
+		}
+	case ir.ODEREF, ir.ODOTPTR:
+		e.discard(n)
+	case ir.OINDEXMAP:
+		n := n.(*ir.IndexExpr)
+		e.discard(n.X)
+		e.assignHeap(n.Index, "key of map put", n)
+	}
+
+	return k
+}
+
+func (e *escape) addrs(l ir.Nodes) []hole {
+	var ks []hole
+	for _, n := range l {
+		ks = append(ks, e.addr(n))
+	}
+	return ks
+}
+
+func (e *escape) assignHeap(src ir.Node, why string, where ir.Node) {
+	e.expr(e.heapHole().note(where, why), src)
+}
+
+// assignList evaluates the assignment dsts... = srcs....
+func (e *escape) assignList(dsts, srcs []ir.Node, why string, where ir.Node) {
+	ks := e.addrs(dsts)
+	for i, k := range ks {
+		var src ir.Node
+		if i < len(srcs) {
+			src = srcs[i]
+		}
+
+		if dst := dsts[i]; dst != nil {
+			// Detect implicit conversion of uintptr to unsafe.Pointer when
+			// storing into reflect.{Slice,String}Header.
+			if dst.Op() == ir.ODOTPTR && ir.IsReflectHeaderDataField(dst) {
+				e.unsafeValue(e.heapHole().note(where, why), src)
+				continue
+			}
+
+			// Filter out some no-op assignments for escape analysis.
+			if src != nil && isSelfAssign(dst, src) {
+				if base.Flag.LowerM != 0 {
+					base.WarnfAt(where.Pos(), "%v ignoring self-assignment in %v", e.curfn, where)
+				}
+				k = e.discardHole()
+			}
+		}
+
+		e.expr(k.note(where, why), src)
+	}
+
+	e.reassigned(ks, where)
+}
+
+// reassigned marks the locations associated with the given holes as
+// reassigned, unless the location represents a variable declared and
+// assigned exactly once by where.
+func (e *escape) reassigned(ks []hole, where ir.Node) {
+	if as, ok := where.(*ir.AssignStmt); ok && as.Op() == ir.OAS && as.Y == nil {
+		if dst, ok := as.X.(*ir.Name); ok && dst.Op() == ir.ONAME && dst.Defn == nil {
+			// Zero-value assignment for variable declared without an
+			// explicit initial value. Assume this is its initialization
+			// statement.
+			return
+		}
+	}
+
+	for _, k := range ks {
+		loc := k.dst
+		// Variables declared by range statements are assigned on every iteration.
+		if n, ok := loc.n.(*ir.Name); ok && n.Defn == where && where.Op() != ir.ORANGE {
+			continue
+		}
+		loc.reassigned = true
+	}
+}
diff --git a/src/cmd/compile/internal/escape/call.go b/src/cmd/compile/internal/escape/call.go
new file mode 100644
index 00000000000..9e5abed5914
--- /dev/null
+++ b/src/cmd/compile/internal/escape/call.go
@@ -0,0 +1,428 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/typecheck"
+	"cmd/compile/internal/types"
+	"cmd/internal/src"
+)
+
+// call evaluates a call expressions, including builtin calls. ks
+// should contain the holes representing where the function callee's
+// results flows.
+func (e *escape) call(ks []hole, call ir.Node) {
+	var init ir.Nodes
+	e.callCommon(ks, call, &init, nil)
+	if len(init) != 0 {
+		call.(*ir.CallExpr).PtrInit().Append(init...)
+	}
+}
+
+func (e *escape) callCommon(ks []hole, call ir.Node, init *ir.Nodes, wrapper *ir.Func) {
+
+	// argumentPragma handles escape analysis of argument *argp to the
+	// given hole. If the function callee is known, pragma is the
+	// function's pragma flags; otherwise 0.
+	argumentFunc := func(fn *ir.Name, k hole, argp *ir.Node) {
+		e.rewriteArgument(argp, init, call, fn, wrapper)
+
+		e.expr(k.note(call, "call parameter"), *argp)
+	}
+
+	argument := func(k hole, argp *ir.Node) {
+		argumentFunc(nil, k, argp)
+	}
+
+	switch call.Op() {
+	default:
+		ir.Dump("esc", call)
+		base.Fatalf("unexpected call op: %v", call.Op())
+
+	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER:
+		call := call.(*ir.CallExpr)
+		typecheck.FixVariadicCall(call)
+		typecheck.FixMethodCall(call)
+
+		// Pick out the function callee, if statically known.
+		//
+		// TODO(mdempsky): Change fn from *ir.Name to *ir.Func, but some
+		// functions (e.g., runtime builtins, method wrappers, generated
+		// eq/hash functions) don't have it set. Investigate whether
+		// that's a concern.
+		var fn *ir.Name
+		switch call.Op() {
+		case ir.OCALLFUNC:
+			// If we have a direct call to a closure (not just one we were
+			// able to statically resolve with ir.StaticValue), mark it as
+			// such so batch.outlives can optimize the flow results.
+			if call.X.Op() == ir.OCLOSURE {
+				call.X.(*ir.ClosureExpr).Func.SetClosureCalled(true)
+			}
+
+			switch v := ir.StaticValue(call.X); v.Op() {
+			case ir.ONAME:
+				if v := v.(*ir.Name); v.Class == ir.PFUNC {
+					fn = v
+				}
+			case ir.OCLOSURE:
+				fn = v.(*ir.ClosureExpr).Func.Nname
+			case ir.OMETHEXPR:
+				fn = ir.MethodExprName(v)
+			}
+		case ir.OCALLMETH:
+			base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck")
+		}
+
+		fntype := call.X.Type()
+		if fn != nil {
+			fntype = fn.Type()
+		}
+
+		if ks != nil && fn != nil && e.inMutualBatch(fn) {
+			for i, result := range fn.Type().Results().FieldSlice() {
+				e.expr(ks[i], ir.AsNode(result.Nname))
+			}
+		}
+
+		var recvp *ir.Node
+		if call.Op() == ir.OCALLFUNC {
+			// Evaluate callee function expression.
+			//
+			// Note: We use argument and not argumentFunc, because while
+			// call.X here may be an argument to runtime.{new,defer}proc,
+			// it's not an argument to fn itself.
+			argument(e.discardHole(), &call.X)
+		} else {
+			recvp = &call.X.(*ir.SelectorExpr).X
+		}
+
+		args := call.Args
+		if recv := fntype.Recv(); recv != nil {
+			if recvp == nil {
+				// Function call using method expression. Recevier argument is
+				// at the front of the regular arguments list.
+				recvp = &args[0]
+				args = args[1:]
+			}
+
+			argumentFunc(fn, e.tagHole(ks, fn, recv), recvp)
+		}
+
+		for i, param := range fntype.Params().FieldSlice() {
+			argumentFunc(fn, e.tagHole(ks, fn, param), &args[i])
+		}
+
+	case ir.OINLCALL:
+		call := call.(*ir.InlinedCallExpr)
+		e.stmts(call.Body)
+		for i, result := range call.ReturnVars {
+			k := e.discardHole()
+			if ks != nil {
+				k = ks[i]
+			}
+			e.expr(k, result)
+		}
+
+	case ir.OAPPEND:
+		call := call.(*ir.CallExpr)
+		args := call.Args
+
+		// Appendee slice may flow directly to the result, if
+		// it has enough capacity. Alternatively, a new heap
+		// slice might be allocated, and all slice elements
+		// might flow to heap.
+		appendeeK := ks[0]
+		if args[0].Type().Elem().HasPointers() {
+			appendeeK = e.teeHole(appendeeK, e.heapHole().deref(call, "appendee slice"))
+		}
+		argument(appendeeK, &args[0])
+
+		if call.IsDDD {
+			appendedK := e.discardHole()
+			if args[1].Type().IsSlice() && args[1].Type().Elem().HasPointers() {
+				appendedK = e.heapHole().deref(call, "appended slice...")
+			}
+			argument(appendedK, &args[1])
+		} else {
+			for i := 1; i < len(args); i++ {
+				argument(e.heapHole(), &args[i])
+			}
+		}
+
+	case ir.OCOPY:
+		call := call.(*ir.BinaryExpr)
+		argument(e.discardHole(), &call.X)
+
+		copiedK := e.discardHole()
+		if call.Y.Type().IsSlice() && call.Y.Type().Elem().HasPointers() {
+			copiedK = e.heapHole().deref(call, "copied slice")
+		}
+		argument(copiedK, &call.Y)
+
+	case ir.OPANIC:
+		call := call.(*ir.UnaryExpr)
+		argument(e.heapHole(), &call.X)
+
+	case ir.OCOMPLEX:
+		call := call.(*ir.BinaryExpr)
+		argument(e.discardHole(), &call.X)
+		argument(e.discardHole(), &call.Y)
+
+	case ir.ODELETE, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
+		call := call.(*ir.CallExpr)
+		fixRecoverCall(call)
+		for i := range call.Args {
+			argument(e.discardHole(), &call.Args[i])
+		}
+
+	case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE:
+		call := call.(*ir.UnaryExpr)
+		argument(e.discardHole(), &call.X)
+
+	case ir.OUNSAFEADD, ir.OUNSAFESLICE:
+		call := call.(*ir.BinaryExpr)
+		argument(ks[0], &call.X)
+		argument(e.discardHole(), &call.Y)
+	}
+}
+
+// goDeferStmt analyzes a "go" or "defer" statement.
+//
+// In the process, it also normalizes the statement to always use a
+// simple function call with no arguments and no results. For example,
+// it rewrites:
+//
+//	defer f(x, y)
+//
+// into:
+//
+//	x1, y1 := x, y
+//	defer func() { f(x1, y1) }()
+func (e *escape) goDeferStmt(n *ir.GoDeferStmt) {
+	k := e.heapHole()
+	if n.Op() == ir.ODEFER && e.loopDepth == 1 {
+		// Top-level defer arguments don't escape to the heap,
+		// but they do need to last until they're invoked.
+		k = e.later(e.discardHole())
+
+		// force stack allocation of defer record, unless
+		// open-coded defers are used (see ssa.go)
+		n.SetEsc(ir.EscNever)
+	}
+
+	call := n.Call
+
+	init := n.PtrInit()
+	init.Append(ir.TakeInit(call)...)
+	e.stmts(*init)
+
+	// If the function is already a zero argument/result function call,
+	// just escape analyze it normally.
+	if call, ok := call.(*ir.CallExpr); ok && call.Op() == ir.OCALLFUNC {
+		if sig := call.X.Type(); sig.NumParams()+sig.NumResults() == 0 {
+			if clo, ok := call.X.(*ir.ClosureExpr); ok && n.Op() == ir.OGO {
+				clo.IsGoWrap = true
+			}
+			e.expr(k, call.X)
+			return
+		}
+	}
+
+	// Create a new no-argument function that we'll hand off to defer.
+	fn := ir.NewClosureFunc(n.Pos(), true)
+	fn.SetWrapper(true)
+	fn.Nname.SetType(types.NewSignature(types.LocalPkg, nil, nil, nil, nil))
+	fn.Body = []ir.Node{call}
+
+	clo := fn.OClosure
+	if n.Op() == ir.OGO {
+		clo.IsGoWrap = true
+	}
+
+	e.callCommon(nil, call, init, fn)
+	e.closures = append(e.closures, closure{e.spill(k, clo), clo})
+
+	// Create new top level call to closure.
+	n.Call = ir.NewCallExpr(call.Pos(), ir.OCALL, clo, nil)
+	ir.WithFunc(e.curfn, func() {
+		typecheck.Stmt(n.Call)
+	})
+}
+
+// rewriteArgument rewrites the argument *argp of the given call expression.
+// fn is the static callee function, if known.
+// wrapper is the go/defer wrapper function for call, if any.
+func (e *escape) rewriteArgument(argp *ir.Node, init *ir.Nodes, call ir.Node, fn *ir.Name, wrapper *ir.Func) {
+	var pragma ir.PragmaFlag
+	if fn != nil && fn.Func != nil {
+		pragma = fn.Func.Pragma
+	}
+
+	// unsafeUintptr rewrites "uintptr(ptr)" arguments to syscall-like
+	// functions, so that ptr is kept alive and/or escaped as
+	// appropriate. unsafeUintptr also reports whether it modified arg0.
+	unsafeUintptr := func(arg0 ir.Node) bool {
+		if pragma&(ir.UintptrKeepAlive|ir.UintptrEscapes) == 0 {
+			return false
+		}
+
+		// If the argument is really a pointer being converted to uintptr,
+		// arrange for the pointer to be kept alive until the call returns,
+		// by copying it into a temp and marking that temp
+		// still alive when we pop the temp stack.
+		if arg0.Op() != ir.OCONVNOP || !arg0.Type().IsUintptr() {
+			return false
+		}
+		arg := arg0.(*ir.ConvExpr)
+
+		if !arg.X.Type().IsUnsafePtr() {
+			return false
+		}
+
+		// Create and declare a new pointer-typed temp variable.
+		tmp := e.wrapExpr(arg.Pos(), &arg.X, init, call, wrapper)
+
+		if pragma&ir.UintptrEscapes != 0 {
+			e.flow(e.heapHole().note(arg, "//go:uintptrescapes"), e.oldLoc(tmp))
+		}
+
+		if pragma&ir.UintptrKeepAlive != 0 {
+			call := call.(*ir.CallExpr)
+
+			// SSA implements CallExpr.KeepAlive using OpVarLive, which
+			// doesn't support PAUTOHEAP variables. I tried changing it to
+			// use OpKeepAlive, but that ran into issues of its own.
+			// For now, the easy solution is to explicitly copy to (yet
+			// another) new temporary variable.
+			keep := tmp
+			if keep.Class == ir.PAUTOHEAP {
+				keep = e.copyExpr(arg.Pos(), tmp, call.PtrInit(), wrapper, false)
+			}
+
+			keep.SetAddrtaken(true) // ensure SSA keeps the tmp variable
+			call.KeepAlive = append(call.KeepAlive, keep)
+		}
+
+		return true
+	}
+
+	visit := func(pos src.XPos, argp *ir.Node) {
+		// Optimize a few common constant expressions. By leaving these
+		// untouched in the call expression, we let the wrapper handle
+		// evaluating them, rather than taking up closure context space.
+		switch arg := *argp; arg.Op() {
+		case ir.OLITERAL, ir.ONIL, ir.OMETHEXPR:
+			return
+		case ir.ONAME:
+			if arg.(*ir.Name).Class == ir.PFUNC {
+				return
+			}
+		}
+
+		if unsafeUintptr(*argp) {
+			return
+		}
+
+		if wrapper != nil {
+			e.wrapExpr(pos, argp, init, call, wrapper)
+		}
+	}
+
+	// Peel away any slice lits.
+	if arg := *argp; arg.Op() == ir.OSLICELIT {
+		list := arg.(*ir.CompLitExpr).List
+		for i := range list {
+			visit(arg.Pos(), &list[i])
+		}
+	} else {
+		visit(call.Pos(), argp)
+	}
+}
+
+// wrapExpr replaces *exprp with a temporary variable copy. If wrapper
+// is non-nil, the variable will be captured for use within that
+// function.
+func (e *escape) wrapExpr(pos src.XPos, exprp *ir.Node, init *ir.Nodes, call ir.Node, wrapper *ir.Func) *ir.Name {
+	tmp := e.copyExpr(pos, *exprp, init, e.curfn, true)
+
+	if wrapper != nil {
+		// Currently for "defer i.M()" if i is nil it panics at the point
+		// of defer statement, not when deferred function is called.  We
+		// need to do the nil check outside of the wrapper.
+		if call.Op() == ir.OCALLINTER && exprp == &call.(*ir.CallExpr).X.(*ir.SelectorExpr).X {
+			check := ir.NewUnaryExpr(pos, ir.OCHECKNIL, ir.NewUnaryExpr(pos, ir.OITAB, tmp))
+			init.Append(typecheck.Stmt(check))
+		}
+
+		e.oldLoc(tmp).captured = true
+
+		tmp = ir.NewClosureVar(pos, wrapper, tmp)
+	}
+
+	*exprp = tmp
+	return tmp
+}
+
+// copyExpr creates and returns a new temporary variable within fn;
+// appends statements to init to declare and initialize it to expr;
+// and escape analyzes the data flow if analyze is true.
+func (e *escape) copyExpr(pos src.XPos, expr ir.Node, init *ir.Nodes, fn *ir.Func, analyze bool) *ir.Name {
+	if ir.HasUniquePos(expr) {
+		pos = expr.Pos()
+	}
+
+	tmp := typecheck.TempAt(pos, fn, expr.Type())
+
+	stmts := []ir.Node{
+		ir.NewDecl(pos, ir.ODCL, tmp),
+		ir.NewAssignStmt(pos, tmp, expr),
+	}
+	typecheck.Stmts(stmts)
+	init.Append(stmts...)
+
+	if analyze {
+		e.newLoc(tmp, false)
+		e.stmts(stmts)
+	}
+
+	return tmp
+}
+
+// tagHole returns a hole for evaluating an argument passed to param.
+// ks should contain the holes representing where the function
+// callee's results flows. fn is the statically-known callee function,
+// if any.
+func (e *escape) tagHole(ks []hole, fn *ir.Name, param *types.Field) hole {
+	// If this is a dynamic call, we can't rely on param.Note.
+	if fn == nil {
+		return e.heapHole()
+	}
+
+	if e.inMutualBatch(fn) {
+		return e.addr(ir.AsNode(param.Nname))
+	}
+
+	// Call to previously tagged function.
+
+	var tagKs []hole
+
+	esc := parseLeaks(param.Note)
+	if x := esc.Heap(); x >= 0 {
+		tagKs = append(tagKs, e.heapHole().shift(x))
+	}
+
+	if ks != nil {
+		for i := 0; i < numEscResults; i++ {
+			if x := esc.Result(i); x >= 0 {
+				tagKs = append(tagKs, ks[i].shift(x))
+			}
+		}
+	}
+
+	return e.teeHole(tagKs...)
+}
diff --git a/src/cmd/compile/internal/escape/desugar.go b/src/cmd/compile/internal/escape/desugar.go
new file mode 100644
index 00000000000..8b3cc25cf9a
--- /dev/null
+++ b/src/cmd/compile/internal/escape/desugar.go
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/typecheck"
+	"cmd/compile/internal/types"
+)
+
+// TODO(mdempsky): Desugaring doesn't belong during escape analysis,
+// but for now it's the most convenient place for some rewrites.
+
+// fixRecoverCall rewrites an ORECOVER call into ORECOVERFP,
+// adding an explicit frame pointer argument.
+// If call is not an ORECOVER call, it's left unmodified.
+func fixRecoverCall(call *ir.CallExpr) {
+	if call.Op() != ir.ORECOVER {
+		return
+	}
+
+	pos := call.Pos()
+
+	// FP is equal to caller's SP plus FixedFrameSize().
+	var fp ir.Node = ir.NewCallExpr(pos, ir.OGETCALLERSP, nil, nil)
+	if off := base.Ctxt.FixedFrameSize(); off != 0 {
+		fp = ir.NewBinaryExpr(fp.Pos(), ir.OADD, fp, ir.NewInt(off))
+	}
+	// TODO(mdempsky): Replace *int32 with unsafe.Pointer, without upsetting checkptr.
+	fp = ir.NewConvExpr(pos, ir.OCONVNOP, types.NewPtr(types.Types[types.TINT32]), fp)
+
+	call.SetOp(ir.ORECOVERFP)
+	call.Args = []ir.Node{typecheck.Expr(fp)}
+}
diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go
index 3ac7ff1ebe1..61e0121a40a 100644
--- a/src/cmd/compile/internal/escape/escape.go
+++ b/src/cmd/compile/internal/escape/escape.go
@@ -6,15 +6,11 @@ package escape
 
 import (
 	"fmt"
-	"math"
-	"strings"
 
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/logopt"
-	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
-	"cmd/internal/src"
 )
 
 // Escape analysis.
@@ -118,90 +114,8 @@ type escape struct {
 	loopDepth int
 }
 
-// An location represents an abstract location that stores a Go
-// variable.
-type location struct {
-	n         ir.Node  // represented variable or expression, if any
-	curfn     *ir.Func // enclosing function
-	edges     []edge   // incoming edges
-	loopDepth int      // loopDepth at declaration
-
-	// resultIndex records the tuple index (starting at 1) for
-	// PPARAMOUT variables within their function's result type.
-	// For non-PPARAMOUT variables it's 0.
-	resultIndex int
-
-	// derefs and walkgen are used during walkOne to track the
-	// minimal dereferences from the walk root.
-	derefs  int // >= -1
-	walkgen uint32
-
-	// dst and dstEdgeindex track the next immediate assignment
-	// destination location during walkone, along with the index
-	// of the edge pointing back to this location.
-	dst        *location
-	dstEdgeIdx int
-
-	// queued is used by walkAll to track whether this location is
-	// in the walk queue.
-	queued bool
-
-	// escapes reports whether the represented variable's address
-	// escapes; that is, whether the variable must be heap
-	// allocated.
-	escapes bool
-
-	// transient reports whether the represented expression's
-	// address does not outlive the statement; that is, whether
-	// its storage can be immediately reused.
-	transient bool
-
-	// paramEsc records the represented parameter's leak set.
-	paramEsc leaks
-
-	captured   bool // has a closure captured this variable?
-	reassigned bool // has this variable been reassigned?
-	addrtaken  bool // has this variable's address been taken?
-}
-
-// An edge represents an assignment edge between two Go variables.
-type edge struct {
-	src    *location
-	derefs int // >= -1
-	notes  *note
-}
-
-// Fmt is called from node printing to print information about escape analysis results.
-func Fmt(n ir.Node) string {
-	text := ""
-	switch n.Esc() {
-	case ir.EscUnknown:
-		break
-
-	case ir.EscHeap:
-		text = "esc(h)"
-
-	case ir.EscNone:
-		text = "esc(no)"
-
-	case ir.EscNever:
-		text = "esc(N)"
-
-	default:
-		text = fmt.Sprintf("esc(%d)", n.Esc())
-	}
-
-	if n.Op() == ir.ONAME {
-		n := n.(*ir.Name)
-		if loc, ok := n.Opt.(*location); ok && loc.loopDepth != 0 {
-			if text != "" {
-				text += " "
-			}
-			text += fmt.Sprintf("ld(%d)", loc.loopDepth)
-		}
-	}
-
-	return text
+func Funcs(all []ir.Node) {
+	ir.VisitFuncsBottomUp(all, Batch)
 }
 
 // Batch performs escape analysis on a minimal batch of
@@ -269,8 +183,14 @@ func (b *batch) initFunc(fn *ir.Func) {
 
 	// Allocate locations for local variables.
 	for _, n := range fn.Dcl {
-		if n.Op() == ir.ONAME {
-			e.newLoc(n, false)
+		e.newLoc(n, false)
+	}
+
+	// Also for hidden parameters (e.g., the ".this" parameter to a
+	// method value wrapper).
+	if fn.OClosure == nil {
+		for _, n := range fn.ClosureVars {
+			e.newLoc(n.Canonical(), false)
 		}
 	}
 
@@ -342,1316 +262,6 @@ func (b *batch) flowClosure(k hole, clo *ir.ClosureExpr) {
 	}
 }
 
-// Below we implement the methods for walking the AST and recording
-// data flow edges. Note that because a sub-expression might have
-// side-effects, it's important to always visit the entire AST.
-//
-// For example, write either:
-//
-//     if x {
-//         e.discard(n.Left)
-//     } else {
-//         e.value(k, n.Left)
-//     }
-//
-// or
-//
-//     if x {
-//         k = e.discardHole()
-//     }
-//     e.value(k, n.Left)
-//
-// Do NOT write:
-//
-//    // BAD: possibly loses side-effects within n.Left
-//    if !x {
-//        e.value(k, n.Left)
-//    }
-
-// stmt evaluates a single Go statement.
-func (e *escape) stmt(n ir.Node) {
-	if n == nil {
-		return
-	}
-
-	lno := ir.SetPos(n)
-	defer func() {
-		base.Pos = lno
-	}()
-
-	if base.Flag.LowerM > 2 {
-		fmt.Printf("%v:[%d] %v stmt: %v\n", base.FmtPos(base.Pos), e.loopDepth, e.curfn, n)
-	}
-
-	e.stmts(n.Init())
-
-	switch n.Op() {
-	default:
-		base.Fatalf("unexpected stmt: %v", n)
-
-	case ir.ODCLCONST, ir.ODCLTYPE, ir.OFALL, ir.OINLMARK:
-		// nop
-
-	case ir.OBREAK, ir.OCONTINUE, ir.OGOTO:
-		// TODO(mdempsky): Handle dead code?
-
-	case ir.OBLOCK:
-		n := n.(*ir.BlockStmt)
-		e.stmts(n.List)
-
-	case ir.ODCL:
-		// Record loop depth at declaration.
-		n := n.(*ir.Decl)
-		if !ir.IsBlank(n.X) {
-			e.dcl(n.X)
-		}
-
-	case ir.OLABEL:
-		n := n.(*ir.LabelStmt)
-		switch e.labels[n.Label] {
-		case nonlooping:
-			if base.Flag.LowerM > 2 {
-				fmt.Printf("%v:%v non-looping label\n", base.FmtPos(base.Pos), n)
-			}
-		case looping:
-			if base.Flag.LowerM > 2 {
-				fmt.Printf("%v: %v looping label\n", base.FmtPos(base.Pos), n)
-			}
-			e.loopDepth++
-		default:
-			base.Fatalf("label missing tag")
-		}
-		delete(e.labels, n.Label)
-
-	case ir.OIF:
-		n := n.(*ir.IfStmt)
-		e.discard(n.Cond)
-		e.block(n.Body)
-		e.block(n.Else)
-
-	case ir.OFOR, ir.OFORUNTIL:
-		n := n.(*ir.ForStmt)
-		e.loopDepth++
-		e.discard(n.Cond)
-		e.stmt(n.Post)
-		e.block(n.Body)
-		e.loopDepth--
-
-	case ir.ORANGE:
-		// for Key, Value = range X { Body }
-		n := n.(*ir.RangeStmt)
-
-		// X is evaluated outside the loop.
-		tmp := e.newLoc(nil, false)
-		e.expr(tmp.asHole(), n.X)
-
-		e.loopDepth++
-		ks := e.addrs([]ir.Node{n.Key, n.Value})
-		if n.X.Type().IsArray() {
-			e.flow(ks[1].note(n, "range"), tmp)
-		} else {
-			e.flow(ks[1].deref(n, "range-deref"), tmp)
-		}
-		e.reassigned(ks, n)
-
-		e.block(n.Body)
-		e.loopDepth--
-
-	case ir.OSWITCH:
-		n := n.(*ir.SwitchStmt)
-
-		if guard, ok := n.Tag.(*ir.TypeSwitchGuard); ok {
-			var ks []hole
-			if guard.Tag != nil {
-				for _, cas := range n.Cases {
-					cv := cas.Var
-					k := e.dcl(cv) // type switch variables have no ODCL.
-					if cv.Type().HasPointers() {
-						ks = append(ks, k.dotType(cv.Type(), cas, "switch case"))
-					}
-				}
-			}
-			e.expr(e.teeHole(ks...), n.Tag.(*ir.TypeSwitchGuard).X)
-		} else {
-			e.discard(n.Tag)
-		}
-
-		for _, cas := range n.Cases {
-			e.discards(cas.List)
-			e.block(cas.Body)
-		}
-
-	case ir.OSELECT:
-		n := n.(*ir.SelectStmt)
-		for _, cas := range n.Cases {
-			e.stmt(cas.Comm)
-			e.block(cas.Body)
-		}
-	case ir.ORECV:
-		// TODO(mdempsky): Consider e.discard(n.Left).
-		n := n.(*ir.UnaryExpr)
-		e.exprSkipInit(e.discardHole(), n) // already visited n.Ninit
-	case ir.OSEND:
-		n := n.(*ir.SendStmt)
-		e.discard(n.Chan)
-		e.assignHeap(n.Value, "send", n)
-
-	case ir.OAS:
-		n := n.(*ir.AssignStmt)
-		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
-	case ir.OASOP:
-		n := n.(*ir.AssignOpStmt)
-		// TODO(mdempsky): Worry about OLSH/ORSH?
-		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
-	case ir.OAS2:
-		n := n.(*ir.AssignListStmt)
-		e.assignList(n.Lhs, n.Rhs, "assign-pair", n)
-
-	case ir.OAS2DOTTYPE: // v, ok = x.(type)
-		n := n.(*ir.AssignListStmt)
-		e.assignList(n.Lhs, n.Rhs, "assign-pair-dot-type", n)
-	case ir.OAS2MAPR: // v, ok = m[k]
-		n := n.(*ir.AssignListStmt)
-		e.assignList(n.Lhs, n.Rhs, "assign-pair-mapr", n)
-	case ir.OAS2RECV, ir.OSELRECV2: // v, ok = <-ch
-		n := n.(*ir.AssignListStmt)
-		e.assignList(n.Lhs, n.Rhs, "assign-pair-receive", n)
-
-	case ir.OAS2FUNC:
-		n := n.(*ir.AssignListStmt)
-		e.stmts(n.Rhs[0].Init())
-		ks := e.addrs(n.Lhs)
-		e.call(ks, n.Rhs[0], nil)
-		e.reassigned(ks, n)
-	case ir.ORETURN:
-		n := n.(*ir.ReturnStmt)
-		results := e.curfn.Type().Results().FieldSlice()
-		dsts := make([]ir.Node, len(results))
-		for i, res := range results {
-			dsts[i] = res.Nname.(*ir.Name)
-		}
-		e.assignList(dsts, n.Results, "return", n)
-	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
-		e.call(nil, n, nil)
-	case ir.OGO, ir.ODEFER:
-		n := n.(*ir.GoDeferStmt)
-		e.stmts(n.Call.Init())
-		e.call(nil, n.Call, n)
-
-	case ir.OTAILCALL:
-		// TODO(mdempsky): Treat like a normal call? esc.go used to just ignore it.
-	}
-}
-
-func (e *escape) stmts(l ir.Nodes) {
-	for _, n := range l {
-		e.stmt(n)
-	}
-}
-
-// block is like stmts, but preserves loopDepth.
-func (e *escape) block(l ir.Nodes) {
-	old := e.loopDepth
-	e.stmts(l)
-	e.loopDepth = old
-}
-
-// expr models evaluating an expression n and flowing the result into
-// hole k.
-func (e *escape) expr(k hole, n ir.Node) {
-	if n == nil {
-		return
-	}
-	e.stmts(n.Init())
-	e.exprSkipInit(k, n)
-}
-
-func (e *escape) exprSkipInit(k hole, n ir.Node) {
-	if n == nil {
-		return
-	}
-
-	lno := ir.SetPos(n)
-	defer func() {
-		base.Pos = lno
-	}()
-
-	uintptrEscapesHack := k.uintptrEscapesHack
-	k.uintptrEscapesHack = false
-
-	if uintptrEscapesHack && n.Op() == ir.OCONVNOP && n.(*ir.ConvExpr).X.Type().IsUnsafePtr() {
-		// nop
-	} else if k.derefs >= 0 && !n.Type().HasPointers() {
-		k.dst = &e.blankLoc
-	}
-
-	switch n.Op() {
-	default:
-		base.Fatalf("unexpected expr: %s %v", n.Op().String(), n)
-
-	case ir.OLITERAL, ir.ONIL, ir.OGETG, ir.OTYPE, ir.OMETHEXPR, ir.OLINKSYMOFFSET:
-		// nop
-
-	case ir.ONAME:
-		n := n.(*ir.Name)
-		if n.Class == ir.PFUNC || n.Class == ir.PEXTERN {
-			return
-		}
-		if n.IsClosureVar() && n.Defn == nil {
-			return // ".this" from method value wrapper
-		}
-		e.flow(k, e.oldLoc(n))
-
-	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT:
-		n := n.(*ir.UnaryExpr)
-		e.discard(n.X)
-	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.ODIV, ir.OMOD, ir.OLSH, ir.ORSH, ir.OAND, ir.OANDNOT, ir.OEQ, ir.ONE, ir.OLT, ir.OLE, ir.OGT, ir.OGE:
-		n := n.(*ir.BinaryExpr)
-		e.discard(n.X)
-		e.discard(n.Y)
-	case ir.OANDAND, ir.OOROR:
-		n := n.(*ir.LogicalExpr)
-		e.discard(n.X)
-		e.discard(n.Y)
-	case ir.OADDR:
-		n := n.(*ir.AddrExpr)
-		e.expr(k.addr(n, "address-of"), n.X) // "address-of"
-	case ir.ODEREF:
-		n := n.(*ir.StarExpr)
-		e.expr(k.deref(n, "indirection"), n.X) // "indirection"
-	case ir.ODOT, ir.ODOTMETH, ir.ODOTINTER:
-		n := n.(*ir.SelectorExpr)
-		e.expr(k.note(n, "dot"), n.X)
-	case ir.ODOTPTR:
-		n := n.(*ir.SelectorExpr)
-		e.expr(k.deref(n, "dot of pointer"), n.X) // "dot of pointer"
-	case ir.ODOTTYPE, ir.ODOTTYPE2:
-		n := n.(*ir.TypeAssertExpr)
-		e.expr(k.dotType(n.Type(), n, "dot"), n.X)
-	case ir.OINDEX:
-		n := n.(*ir.IndexExpr)
-		if n.X.Type().IsArray() {
-			e.expr(k.note(n, "fixed-array-index-of"), n.X)
-		} else {
-			// TODO(mdempsky): Fix why reason text.
-			e.expr(k.deref(n, "dot of pointer"), n.X)
-		}
-		e.discard(n.Index)
-	case ir.OINDEXMAP:
-		n := n.(*ir.IndexExpr)
-		e.discard(n.X)
-		e.discard(n.Index)
-	case ir.OSLICE, ir.OSLICEARR, ir.OSLICE3, ir.OSLICE3ARR, ir.OSLICESTR:
-		n := n.(*ir.SliceExpr)
-		e.expr(k.note(n, "slice"), n.X)
-		e.discard(n.Low)
-		e.discard(n.High)
-		e.discard(n.Max)
-
-	case ir.OCONV, ir.OCONVNOP:
-		n := n.(*ir.ConvExpr)
-		if ir.ShouldCheckPtr(e.curfn, 2) && n.Type().IsUnsafePtr() && n.X.Type().IsPtr() {
-			// When -d=checkptr=2 is enabled, treat
-			// conversions to unsafe.Pointer as an
-			// escaping operation. This allows better
-			// runtime instrumentation, since we can more
-			// easily detect object boundaries on the heap
-			// than the stack.
-			e.assignHeap(n.X, "conversion to unsafe.Pointer", n)
-		} else if n.Type().IsUnsafePtr() && n.X.Type().IsUintptr() {
-			e.unsafeValue(k, n.X)
-		} else {
-			e.expr(k, n.X)
-		}
-	case ir.OCONVIFACE:
-		n := n.(*ir.ConvExpr)
-		if !n.X.Type().IsInterface() && !types.IsDirectIface(n.X.Type()) {
-			k = e.spill(k, n)
-		}
-		e.expr(k.note(n, "interface-converted"), n.X)
-	case ir.OSLICE2ARRPTR:
-		// the slice pointer flows directly to the result
-		n := n.(*ir.ConvExpr)
-		e.expr(k, n.X)
-	case ir.ORECV:
-		n := n.(*ir.UnaryExpr)
-		e.discard(n.X)
-
-	case ir.OCALLMETH, ir.OCALLFUNC, ir.OCALLINTER, ir.OLEN, ir.OCAP, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY, ir.OUNSAFEADD, ir.OUNSAFESLICE:
-		e.call([]hole{k}, n, nil)
-
-	case ir.ONEW:
-		n := n.(*ir.UnaryExpr)
-		e.spill(k, n)
-
-	case ir.OMAKESLICE:
-		n := n.(*ir.MakeExpr)
-		e.spill(k, n)
-		e.discard(n.Len)
-		e.discard(n.Cap)
-	case ir.OMAKECHAN:
-		n := n.(*ir.MakeExpr)
-		e.discard(n.Len)
-	case ir.OMAKEMAP:
-		n := n.(*ir.MakeExpr)
-		e.spill(k, n)
-		e.discard(n.Len)
-
-	case ir.ORECOVER:
-		// nop
-
-	case ir.OCALLPART:
-		// Flow the receiver argument to both the closure and
-		// to the receiver parameter.
-
-		n := n.(*ir.SelectorExpr)
-		closureK := e.spill(k, n)
-
-		m := n.Selection
-
-		// We don't know how the method value will be called
-		// later, so conservatively assume the result
-		// parameters all flow to the heap.
-		//
-		// TODO(mdempsky): Change ks into a callback, so that
-		// we don't have to create this slice?
-		var ks []hole
-		for i := m.Type.NumResults(); i > 0; i-- {
-			ks = append(ks, e.heapHole())
-		}
-		name, _ := m.Nname.(*ir.Name)
-		paramK := e.tagHole(ks, name, m.Type.Recv())
-
-		e.expr(e.teeHole(paramK, closureK), n.X)
-
-	case ir.OPTRLIT:
-		n := n.(*ir.AddrExpr)
-		e.expr(e.spill(k, n), n.X)
-
-	case ir.OARRAYLIT:
-		n := n.(*ir.CompLitExpr)
-		for _, elt := range n.List {
-			if elt.Op() == ir.OKEY {
-				elt = elt.(*ir.KeyExpr).Value
-			}
-			e.expr(k.note(n, "array literal element"), elt)
-		}
-
-	case ir.OSLICELIT:
-		n := n.(*ir.CompLitExpr)
-		k = e.spill(k, n)
-		k.uintptrEscapesHack = uintptrEscapesHack // for ...uintptr parameters
-
-		for _, elt := range n.List {
-			if elt.Op() == ir.OKEY {
-				elt = elt.(*ir.KeyExpr).Value
-			}
-			e.expr(k.note(n, "slice-literal-element"), elt)
-		}
-
-	case ir.OSTRUCTLIT:
-		n := n.(*ir.CompLitExpr)
-		for _, elt := range n.List {
-			e.expr(k.note(n, "struct literal element"), elt.(*ir.StructKeyExpr).Value)
-		}
-
-	case ir.OMAPLIT:
-		n := n.(*ir.CompLitExpr)
-		e.spill(k, n)
-
-		// Map keys and values are always stored in the heap.
-		for _, elt := range n.List {
-			elt := elt.(*ir.KeyExpr)
-			e.assignHeap(elt.Key, "map literal key", n)
-			e.assignHeap(elt.Value, "map literal value", n)
-		}
-
-	case ir.OCLOSURE:
-		n := n.(*ir.ClosureExpr)
-		k = e.spill(k, n)
-		e.closures = append(e.closures, closure{k, n})
-
-		if fn := n.Func; fn.IsHiddenClosure() {
-			for _, cv := range fn.ClosureVars {
-				if loc := e.oldLoc(cv); !loc.captured {
-					loc.captured = true
-
-					// Ignore reassignments to the variable in straightline code
-					// preceding the first capture by a closure.
-					if loc.loopDepth == e.loopDepth {
-						loc.reassigned = false
-					}
-				}
-			}
-
-			for _, n := range fn.Dcl {
-				// Add locations for local variables of the
-				// closure, if needed, in case we're not including
-				// the closure func in the batch for escape
-				// analysis (happens for escape analysis called
-				// from reflectdata.methodWrapper)
-				if n.Op() == ir.ONAME && n.Opt == nil {
-					e.with(fn).newLoc(n, false)
-				}
-			}
-			e.walkFunc(fn)
-		}
-
-	case ir.ORUNES2STR, ir.OBYTES2STR, ir.OSTR2RUNES, ir.OSTR2BYTES, ir.ORUNESTR:
-		n := n.(*ir.ConvExpr)
-		e.spill(k, n)
-		e.discard(n.X)
-
-	case ir.OADDSTR:
-		n := n.(*ir.AddStringExpr)
-		e.spill(k, n)
-
-		// Arguments of OADDSTR never escape;
-		// runtime.concatstrings makes sure of that.
-		e.discards(n.List)
-	}
-}
-
-// unsafeValue evaluates a uintptr-typed arithmetic expression looking
-// for conversions from an unsafe.Pointer.
-func (e *escape) unsafeValue(k hole, n ir.Node) {
-	if n.Type().Kind() != types.TUINTPTR {
-		base.Fatalf("unexpected type %v for %v", n.Type(), n)
-	}
-	if k.addrtaken {
-		base.Fatalf("unexpected addrtaken")
-	}
-
-	e.stmts(n.Init())
-
-	switch n.Op() {
-	case ir.OCONV, ir.OCONVNOP:
-		n := n.(*ir.ConvExpr)
-		if n.X.Type().IsUnsafePtr() {
-			e.expr(k, n.X)
-		} else {
-			e.discard(n.X)
-		}
-	case ir.ODOTPTR:
-		n := n.(*ir.SelectorExpr)
-		if ir.IsReflectHeaderDataField(n) {
-			e.expr(k.deref(n, "reflect.Header.Data"), n.X)
-		} else {
-			e.discard(n.X)
-		}
-	case ir.OPLUS, ir.ONEG, ir.OBITNOT:
-		n := n.(*ir.UnaryExpr)
-		e.unsafeValue(k, n.X)
-	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.ODIV, ir.OMOD, ir.OAND, ir.OANDNOT:
-		n := n.(*ir.BinaryExpr)
-		e.unsafeValue(k, n.X)
-		e.unsafeValue(k, n.Y)
-	case ir.OLSH, ir.ORSH:
-		n := n.(*ir.BinaryExpr)
-		e.unsafeValue(k, n.X)
-		// RHS need not be uintptr-typed (#32959) and can't meaningfully
-		// flow pointers anyway.
-		e.discard(n.Y)
-	default:
-		e.exprSkipInit(e.discardHole(), n)
-	}
-}
-
-// discard evaluates an expression n for side-effects, but discards
-// its value.
-func (e *escape) discard(n ir.Node) {
-	e.expr(e.discardHole(), n)
-}
-
-func (e *escape) discards(l ir.Nodes) {
-	for _, n := range l {
-		e.discard(n)
-	}
-}
-
-// addr evaluates an addressable expression n and returns a hole
-// that represents storing into the represented location.
-func (e *escape) addr(n ir.Node) hole {
-	if n == nil || ir.IsBlank(n) {
-		// Can happen in select case, range, maybe others.
-		return e.discardHole()
-	}
-
-	k := e.heapHole()
-
-	switch n.Op() {
-	default:
-		base.Fatalf("unexpected addr: %v", n)
-	case ir.ONAME:
-		n := n.(*ir.Name)
-		if n.Class == ir.PEXTERN {
-			break
-		}
-		k = e.oldLoc(n).asHole()
-	case ir.OLINKSYMOFFSET:
-		break
-	case ir.ODOT:
-		n := n.(*ir.SelectorExpr)
-		k = e.addr(n.X)
-	case ir.OINDEX:
-		n := n.(*ir.IndexExpr)
-		e.discard(n.Index)
-		if n.X.Type().IsArray() {
-			k = e.addr(n.X)
-		} else {
-			e.discard(n.X)
-		}
-	case ir.ODEREF, ir.ODOTPTR:
-		e.discard(n)
-	case ir.OINDEXMAP:
-		n := n.(*ir.IndexExpr)
-		e.discard(n.X)
-		e.assignHeap(n.Index, "key of map put", n)
-	}
-
-	return k
-}
-
-func (e *escape) addrs(l ir.Nodes) []hole {
-	var ks []hole
-	for _, n := range l {
-		ks = append(ks, e.addr(n))
-	}
-	return ks
-}
-
-// reassigned marks the locations associated with the given holes as
-// reassigned, unless the location represents a variable declared and
-// assigned exactly once by where.
-func (e *escape) reassigned(ks []hole, where ir.Node) {
-	if as, ok := where.(*ir.AssignStmt); ok && as.Op() == ir.OAS && as.Y == nil {
-		if dst, ok := as.X.(*ir.Name); ok && dst.Op() == ir.ONAME && dst.Defn == nil {
-			// Zero-value assignment for variable declared without an
-			// explicit initial value. Assume this is its initialization
-			// statement.
-			return
-		}
-	}
-
-	for _, k := range ks {
-		loc := k.dst
-		// Variables declared by range statements are assigned on every iteration.
-		if n, ok := loc.n.(*ir.Name); ok && n.Defn == where && where.Op() != ir.ORANGE {
-			continue
-		}
-		loc.reassigned = true
-	}
-}
-
-// assignList evaluates the assignment dsts... = srcs....
-func (e *escape) assignList(dsts, srcs []ir.Node, why string, where ir.Node) {
-	ks := e.addrs(dsts)
-	for i, k := range ks {
-		var src ir.Node
-		if i < len(srcs) {
-			src = srcs[i]
-		}
-
-		if dst := dsts[i]; dst != nil {
-			// Detect implicit conversion of uintptr to unsafe.Pointer when
-			// storing into reflect.{Slice,String}Header.
-			if dst.Op() == ir.ODOTPTR && ir.IsReflectHeaderDataField(dst) {
-				e.unsafeValue(e.heapHole().note(where, why), src)
-				continue
-			}
-
-			// Filter out some no-op assignments for escape analysis.
-			if src != nil && isSelfAssign(dst, src) {
-				if base.Flag.LowerM != 0 {
-					base.WarnfAt(where.Pos(), "%v ignoring self-assignment in %v", e.curfn, where)
-				}
-				k = e.discardHole()
-			}
-		}
-
-		e.expr(k.note(where, why), src)
-	}
-
-	e.reassigned(ks, where)
-}
-
-func (e *escape) assignHeap(src ir.Node, why string, where ir.Node) {
-	e.expr(e.heapHole().note(where, why), src)
-}
-
-// call evaluates a call expressions, including builtin calls. ks
-// should contain the holes representing where the function callee's
-// results flows; where is the OGO/ODEFER context of the call, if any.
-func (e *escape) call(ks []hole, call, where ir.Node) {
-	topLevelDefer := where != nil && where.Op() == ir.ODEFER && e.loopDepth == 1
-	if topLevelDefer {
-		// force stack allocation of defer record, unless
-		// open-coded defers are used (see ssa.go)
-		where.SetEsc(ir.EscNever)
-	}
-
-	argument := func(k hole, arg ir.Node) {
-		if topLevelDefer {
-			// Top level defers arguments don't escape to
-			// heap, but they do need to last until end of
-			// function.
-			k = e.later(k)
-		} else if where != nil {
-			k = e.heapHole()
-		}
-
-		e.expr(k.note(call, "call parameter"), arg)
-	}
-
-	switch call.Op() {
-	default:
-		ir.Dump("esc", call)
-		base.Fatalf("unexpected call op: %v", call.Op())
-
-	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER:
-		call := call.(*ir.CallExpr)
-		typecheck.FixVariadicCall(call)
-
-		// Pick out the function callee, if statically known.
-		var fn *ir.Name
-		switch call.Op() {
-		case ir.OCALLFUNC:
-			switch v := ir.StaticValue(call.X); {
-			case v.Op() == ir.ONAME && v.(*ir.Name).Class == ir.PFUNC:
-				fn = v.(*ir.Name)
-			case v.Op() == ir.OCLOSURE:
-				fn = v.(*ir.ClosureExpr).Func.Nname
-			}
-		case ir.OCALLMETH:
-			fn = ir.MethodExprName(call.X)
-		}
-
-		fntype := call.X.Type()
-		if fn != nil {
-			fntype = fn.Type()
-		}
-
-		if ks != nil && fn != nil && e.inMutualBatch(fn) {
-			for i, result := range fn.Type().Results().FieldSlice() {
-				e.expr(ks[i], ir.AsNode(result.Nname))
-			}
-		}
-
-		if r := fntype.Recv(); r != nil {
-			argument(e.tagHole(ks, fn, r), call.X.(*ir.SelectorExpr).X)
-		} else {
-			// Evaluate callee function expression.
-			argument(e.discardHole(), call.X)
-		}
-
-		args := call.Args
-		for i, param := range fntype.Params().FieldSlice() {
-			argument(e.tagHole(ks, fn, param), args[i])
-		}
-
-	case ir.OAPPEND:
-		call := call.(*ir.CallExpr)
-		args := call.Args
-
-		// Appendee slice may flow directly to the result, if
-		// it has enough capacity. Alternatively, a new heap
-		// slice might be allocated, and all slice elements
-		// might flow to heap.
-		appendeeK := ks[0]
-		if args[0].Type().Elem().HasPointers() {
-			appendeeK = e.teeHole(appendeeK, e.heapHole().deref(call, "appendee slice"))
-		}
-		argument(appendeeK, args[0])
-
-		if call.IsDDD {
-			appendedK := e.discardHole()
-			if args[1].Type().IsSlice() && args[1].Type().Elem().HasPointers() {
-				appendedK = e.heapHole().deref(call, "appended slice...")
-			}
-			argument(appendedK, args[1])
-		} else {
-			for _, arg := range args[1:] {
-				argument(e.heapHole(), arg)
-			}
-		}
-
-	case ir.OCOPY:
-		call := call.(*ir.BinaryExpr)
-		argument(e.discardHole(), call.X)
-
-		copiedK := e.discardHole()
-		if call.Y.Type().IsSlice() && call.Y.Type().Elem().HasPointers() {
-			copiedK = e.heapHole().deref(call, "copied slice")
-		}
-		argument(copiedK, call.Y)
-
-	case ir.OPANIC:
-		call := call.(*ir.UnaryExpr)
-		argument(e.heapHole(), call.X)
-
-	case ir.OCOMPLEX:
-		call := call.(*ir.BinaryExpr)
-		argument(e.discardHole(), call.X)
-		argument(e.discardHole(), call.Y)
-	case ir.ODELETE, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
-		call := call.(*ir.CallExpr)
-		for _, arg := range call.Args {
-			argument(e.discardHole(), arg)
-		}
-	case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE:
-		call := call.(*ir.UnaryExpr)
-		argument(e.discardHole(), call.X)
-
-	case ir.OUNSAFEADD, ir.OUNSAFESLICE:
-		call := call.(*ir.BinaryExpr)
-		argument(ks[0], call.X)
-		argument(e.discardHole(), call.Y)
-	}
-}
-
-// tagHole returns a hole for evaluating an argument passed to param.
-// ks should contain the holes representing where the function
-// callee's results flows. fn is the statically-known callee function,
-// if any.
-func (e *escape) tagHole(ks []hole, fn *ir.Name, param *types.Field) hole {
-	// If this is a dynamic call, we can't rely on param.Note.
-	if fn == nil {
-		return e.heapHole()
-	}
-
-	if e.inMutualBatch(fn) {
-		return e.addr(ir.AsNode(param.Nname))
-	}
-
-	// Call to previously tagged function.
-
-	if param.Note == UintptrEscapesNote {
-		k := e.heapHole()
-		k.uintptrEscapesHack = true
-		return k
-	}
-
-	var tagKs []hole
-
-	esc := parseLeaks(param.Note)
-	if x := esc.Heap(); x >= 0 {
-		tagKs = append(tagKs, e.heapHole().shift(x))
-	}
-
-	if ks != nil {
-		for i := 0; i < numEscResults; i++ {
-			if x := esc.Result(i); x >= 0 {
-				tagKs = append(tagKs, ks[i].shift(x))
-			}
-		}
-	}
-
-	return e.teeHole(tagKs...)
-}
-
-// inMutualBatch reports whether function fn is in the batch of
-// mutually recursive functions being analyzed. When this is true,
-// fn has not yet been analyzed, so its parameters and results
-// should be incorporated directly into the flow graph instead of
-// relying on its escape analysis tagging.
-func (e *escape) inMutualBatch(fn *ir.Name) bool {
-	if fn.Defn != nil && fn.Defn.Esc() < escFuncTagged {
-		if fn.Defn.Esc() == escFuncUnknown {
-			base.Fatalf("graph inconsistency: %v", fn)
-		}
-		return true
-	}
-	return false
-}
-
-// An hole represents a context for evaluation a Go
-// expression. E.g., when evaluating p in "x = **p", we'd have a hole
-// with dst==x and derefs==2.
-type hole struct {
-	dst    *location
-	derefs int // >= -1
-	notes  *note
-
-	// addrtaken indicates whether this context is taking the address of
-	// the expression, independent of whether the address will actually
-	// be stored into a variable.
-	addrtaken bool
-
-	// uintptrEscapesHack indicates this context is evaluating an
-	// argument for a //go:uintptrescapes function.
-	uintptrEscapesHack bool
-}
-
-type note struct {
-	next  *note
-	where ir.Node
-	why   string
-}
-
-func (k hole) note(where ir.Node, why string) hole {
-	if where == nil || why == "" {
-		base.Fatalf("note: missing where/why")
-	}
-	if base.Flag.LowerM >= 2 || logopt.Enabled() {
-		k.notes = ¬e{
-			next:  k.notes,
-			where: where,
-			why:   why,
-		}
-	}
-	return k
-}
-
-func (k hole) shift(delta int) hole {
-	k.derefs += delta
-	if k.derefs < -1 {
-		base.Fatalf("derefs underflow: %v", k.derefs)
-	}
-	k.addrtaken = delta < 0
-	return k
-}
-
-func (k hole) deref(where ir.Node, why string) hole { return k.shift(1).note(where, why) }
-func (k hole) addr(where ir.Node, why string) hole  { return k.shift(-1).note(where, why) }
-
-func (k hole) dotType(t *types.Type, where ir.Node, why string) hole {
-	if !t.IsInterface() && !types.IsDirectIface(t) {
-		k = k.shift(1)
-	}
-	return k.note(where, why)
-}
-
-// teeHole returns a new hole that flows into each hole of ks,
-// similar to the Unix tee(1) command.
-func (e *escape) teeHole(ks ...hole) hole {
-	if len(ks) == 0 {
-		return e.discardHole()
-	}
-	if len(ks) == 1 {
-		return ks[0]
-	}
-	// TODO(mdempsky): Optimize if there's only one non-discard hole?
-
-	// Given holes "l1 = _", "l2 = **_", "l3 = *_", ..., create a
-	// new temporary location ltmp, wire it into place, and return
-	// a hole for "ltmp = _".
-	loc := e.newLoc(nil, true)
-	for _, k := range ks {
-		// N.B., "p = &q" and "p = &tmp; tmp = q" are not
-		// semantically equivalent. To combine holes like "l1
-		// = _" and "l2 = &_", we'd need to wire them as "l1 =
-		// *ltmp" and "l2 = ltmp" and return "ltmp = &_"
-		// instead.
-		if k.derefs < 0 {
-			base.Fatalf("teeHole: negative derefs")
-		}
-
-		e.flow(k, loc)
-	}
-	return loc.asHole()
-}
-
-func (e *escape) dcl(n *ir.Name) hole {
-	if n.Curfn != e.curfn || n.IsClosureVar() {
-		base.Fatalf("bad declaration of %v", n)
-	}
-	loc := e.oldLoc(n)
-	loc.loopDepth = e.loopDepth
-	return loc.asHole()
-}
-
-// spill allocates a new location associated with expression n, flows
-// its address to k, and returns a hole that flows values to it. It's
-// intended for use with most expressions that allocate storage.
-func (e *escape) spill(k hole, n ir.Node) hole {
-	loc := e.newLoc(n, true)
-	e.flow(k.addr(n, "spill"), loc)
-	return loc.asHole()
-}
-
-// later returns a new hole that flows into k, but some time later.
-// Its main effect is to prevent immediate reuse of temporary
-// variables introduced during Order.
-func (e *escape) later(k hole) hole {
-	loc := e.newLoc(nil, false)
-	e.flow(k, loc)
-	return loc.asHole()
-}
-
-func (e *escape) newLoc(n ir.Node, transient bool) *location {
-	if e.curfn == nil {
-		base.Fatalf("e.curfn isn't set")
-	}
-	if n != nil && n.Type() != nil && n.Type().NotInHeap() {
-		base.ErrorfAt(n.Pos(), "%v is incomplete (or unallocatable); stack allocation disallowed", n.Type())
-	}
-
-	if n != nil && n.Op() == ir.ONAME {
-		n = n.(*ir.Name).Canonical()
-	}
-	loc := &location{
-		n:         n,
-		curfn:     e.curfn,
-		loopDepth: e.loopDepth,
-		transient: transient,
-	}
-	e.allLocs = append(e.allLocs, loc)
-	if n != nil {
-		if n.Op() == ir.ONAME {
-			n := n.(*ir.Name)
-			if n.Curfn != e.curfn {
-				base.Fatalf("curfn mismatch: %v != %v for %v", n.Curfn, e.curfn, n)
-			}
-
-			if n.Opt != nil {
-				base.Fatalf("%v already has a location", n)
-			}
-			n.Opt = loc
-		}
-	}
-	return loc
-}
-
-func (b *batch) oldLoc(n *ir.Name) *location {
-	if n.Canonical().Opt == nil {
-		base.Fatalf("%v has no location", n)
-	}
-	return n.Canonical().Opt.(*location)
-}
-
-func (l *location) asHole() hole {
-	return hole{dst: l}
-}
-
-func (b *batch) flow(k hole, src *location) {
-	if k.addrtaken {
-		src.addrtaken = true
-	}
-
-	dst := k.dst
-	if dst == &b.blankLoc {
-		return
-	}
-	if dst == src && k.derefs >= 0 { // dst = dst, dst = *dst, ...
-		return
-	}
-	if dst.escapes && k.derefs < 0 { // dst = &src
-		if base.Flag.LowerM >= 2 || logopt.Enabled() {
-			pos := base.FmtPos(src.n.Pos())
-			if base.Flag.LowerM >= 2 {
-				fmt.Printf("%s: %v escapes to heap:\n", pos, src.n)
-			}
-			explanation := b.explainFlow(pos, dst, src, k.derefs, k.notes, []*logopt.LoggedOpt{})
-			if logopt.Enabled() {
-				var e_curfn *ir.Func // TODO(mdempsky): Fix.
-				logopt.LogOpt(src.n.Pos(), "escapes", "escape", ir.FuncName(e_curfn), fmt.Sprintf("%v escapes to heap", src.n), explanation)
-			}
-
-		}
-		src.escapes = true
-		return
-	}
-
-	// TODO(mdempsky): Deduplicate edges?
-	dst.edges = append(dst.edges, edge{src: src, derefs: k.derefs, notes: k.notes})
-}
-
-func (b *batch) heapHole() hole    { return b.heapLoc.asHole() }
-func (b *batch) discardHole() hole { return b.blankLoc.asHole() }
-
-// walkAll computes the minimal dereferences between all pairs of
-// locations.
-func (b *batch) walkAll() {
-	// We use a work queue to keep track of locations that we need
-	// to visit, and repeatedly walk until we reach a fixed point.
-	//
-	// We walk once from each location (including the heap), and
-	// then re-enqueue each location on its transition from
-	// transient->!transient and !escapes->escapes, which can each
-	// happen at most once. So we take Θ(len(e.allLocs)) walks.
-
-	// LIFO queue, has enough room for e.allLocs and e.heapLoc.
-	todo := make([]*location, 0, len(b.allLocs)+1)
-	enqueue := func(loc *location) {
-		if !loc.queued {
-			todo = append(todo, loc)
-			loc.queued = true
-		}
-	}
-
-	for _, loc := range b.allLocs {
-		enqueue(loc)
-	}
-	enqueue(&b.heapLoc)
-
-	var walkgen uint32
-	for len(todo) > 0 {
-		root := todo[len(todo)-1]
-		todo = todo[:len(todo)-1]
-		root.queued = false
-
-		walkgen++
-		b.walkOne(root, walkgen, enqueue)
-	}
-}
-
-// walkOne computes the minimal number of dereferences from root to
-// all other locations.
-func (b *batch) walkOne(root *location, walkgen uint32, enqueue func(*location)) {
-	// The data flow graph has negative edges (from addressing
-	// operations), so we use the Bellman-Ford algorithm. However,
-	// we don't have to worry about infinite negative cycles since
-	// we bound intermediate dereference counts to 0.
-
-	root.walkgen = walkgen
-	root.derefs = 0
-	root.dst = nil
-
-	todo := []*location{root} // LIFO queue
-	for len(todo) > 0 {
-		l := todo[len(todo)-1]
-		todo = todo[:len(todo)-1]
-
-		derefs := l.derefs
-
-		// If l.derefs < 0, then l's address flows to root.
-		addressOf := derefs < 0
-		if addressOf {
-			// For a flow path like "root = &l; l = x",
-			// l's address flows to root, but x's does
-			// not. We recognize this by lower bounding
-			// derefs at 0.
-			derefs = 0
-
-			// If l's address flows to a non-transient
-			// location, then l can't be transiently
-			// allocated.
-			if !root.transient && l.transient {
-				l.transient = false
-				enqueue(l)
-			}
-		}
-
-		if b.outlives(root, l) {
-			// l's value flows to root. If l is a function
-			// parameter and root is the heap or a
-			// corresponding result parameter, then record
-			// that value flow for tagging the function
-			// later.
-			if l.isName(ir.PPARAM) {
-				if (logopt.Enabled() || base.Flag.LowerM >= 2) && !l.escapes {
-					if base.Flag.LowerM >= 2 {
-						fmt.Printf("%s: parameter %v leaks to %s with derefs=%d:\n", base.FmtPos(l.n.Pos()), l.n, b.explainLoc(root), derefs)
-					}
-					explanation := b.explainPath(root, l)
-					if logopt.Enabled() {
-						var e_curfn *ir.Func // TODO(mdempsky): Fix.
-						logopt.LogOpt(l.n.Pos(), "leak", "escape", ir.FuncName(e_curfn),
-							fmt.Sprintf("parameter %v leaks to %s with derefs=%d", l.n, b.explainLoc(root), derefs), explanation)
-					}
-				}
-				l.leakTo(root, derefs)
-			}
-
-			// If l's address flows somewhere that
-			// outlives it, then l needs to be heap
-			// allocated.
-			if addressOf && !l.escapes {
-				if logopt.Enabled() || base.Flag.LowerM >= 2 {
-					if base.Flag.LowerM >= 2 {
-						fmt.Printf("%s: %v escapes to heap:\n", base.FmtPos(l.n.Pos()), l.n)
-					}
-					explanation := b.explainPath(root, l)
-					if logopt.Enabled() {
-						var e_curfn *ir.Func // TODO(mdempsky): Fix.
-						logopt.LogOpt(l.n.Pos(), "escape", "escape", ir.FuncName(e_curfn), fmt.Sprintf("%v escapes to heap", l.n), explanation)
-					}
-				}
-				l.escapes = true
-				enqueue(l)
-				continue
-			}
-		}
-
-		for i, edge := range l.edges {
-			if edge.src.escapes {
-				continue
-			}
-			d := derefs + edge.derefs
-			if edge.src.walkgen != walkgen || edge.src.derefs > d {
-				edge.src.walkgen = walkgen
-				edge.src.derefs = d
-				edge.src.dst = l
-				edge.src.dstEdgeIdx = i
-				todo = append(todo, edge.src)
-			}
-		}
-	}
-}
-
-// explainPath prints an explanation of how src flows to the walk root.
-func (b *batch) explainPath(root, src *location) []*logopt.LoggedOpt {
-	visited := make(map[*location]bool)
-	pos := base.FmtPos(src.n.Pos())
-	var explanation []*logopt.LoggedOpt
-	for {
-		// Prevent infinite loop.
-		if visited[src] {
-			if base.Flag.LowerM >= 2 {
-				fmt.Printf("%s:   warning: truncated explanation due to assignment cycle; see golang.org/issue/35518\n", pos)
-			}
-			break
-		}
-		visited[src] = true
-		dst := src.dst
-		edge := &dst.edges[src.dstEdgeIdx]
-		if edge.src != src {
-			base.Fatalf("path inconsistency: %v != %v", edge.src, src)
-		}
-
-		explanation = b.explainFlow(pos, dst, src, edge.derefs, edge.notes, explanation)
-
-		if dst == root {
-			break
-		}
-		src = dst
-	}
-
-	return explanation
-}
-
-func (b *batch) explainFlow(pos string, dst, srcloc *location, derefs int, notes *note, explanation []*logopt.LoggedOpt) []*logopt.LoggedOpt {
-	ops := "&"
-	if derefs >= 0 {
-		ops = strings.Repeat("*", derefs)
-	}
-	print := base.Flag.LowerM >= 2
-
-	flow := fmt.Sprintf("   flow: %s = %s%v:", b.explainLoc(dst), ops, b.explainLoc(srcloc))
-	if print {
-		fmt.Printf("%s:%s\n", pos, flow)
-	}
-	if logopt.Enabled() {
-		var epos src.XPos
-		if notes != nil {
-			epos = notes.where.Pos()
-		} else if srcloc != nil && srcloc.n != nil {
-			epos = srcloc.n.Pos()
-		}
-		var e_curfn *ir.Func // TODO(mdempsky): Fix.
-		explanation = append(explanation, logopt.NewLoggedOpt(epos, "escflow", "escape", ir.FuncName(e_curfn), flow))
-	}
-
-	for note := notes; note != nil; note = note.next {
-		if print {
-			fmt.Printf("%s:     from %v (%v) at %s\n", pos, note.where, note.why, base.FmtPos(note.where.Pos()))
-		}
-		if logopt.Enabled() {
-			var e_curfn *ir.Func // TODO(mdempsky): Fix.
-			explanation = append(explanation, logopt.NewLoggedOpt(note.where.Pos(), "escflow", "escape", ir.FuncName(e_curfn),
-				fmt.Sprintf("     from %v (%v)", note.where, note.why)))
-		}
-	}
-	return explanation
-}
-
-func (b *batch) explainLoc(l *location) string {
-	if l == &b.heapLoc {
-		return "{heap}"
-	}
-	if l.n == nil {
-		// TODO(mdempsky): Omit entirely.
-		return "{temp}"
-	}
-	if l.n.Op() == ir.ONAME {
-		return fmt.Sprintf("%v", l.n)
-	}
-	return fmt.Sprintf("{storage for %v}", l.n)
-}
-
-// outlives reports whether values stored in l may survive beyond
-// other's lifetime if stack allocated.
-func (b *batch) outlives(l, other *location) bool {
-	// The heap outlives everything.
-	if l.escapes {
-		return true
-	}
-
-	// We don't know what callers do with returned values, so
-	// pessimistically we need to assume they flow to the heap and
-	// outlive everything too.
-	if l.isName(ir.PPARAMOUT) {
-		// Exception: Directly called closures can return
-		// locations allocated outside of them without forcing
-		// them to the heap. For example:
-		//
-		//    var u int  // okay to stack allocate
-		//    *(func() *int { return &u }()) = 42
-		if containsClosure(other.curfn, l.curfn) && l.curfn.ClosureCalled() {
-			return false
-		}
-
-		return true
-	}
-
-	// If l and other are within the same function, then l
-	// outlives other if it was declared outside other's loop
-	// scope. For example:
-	//
-	//    var l *int
-	//    for {
-	//        l = new(int)
-	//    }
-	if l.curfn == other.curfn && l.loopDepth < other.loopDepth {
-		return true
-	}
-
-	// If other is declared within a child closure of where l is
-	// declared, then l outlives it. For example:
-	//
-	//    var l *int
-	//    func() {
-	//        l = new(int)
-	//    }
-	if containsClosure(l.curfn, other.curfn) {
-		return true
-	}
-
-	return false
-}
-
-// containsClosure reports whether c is a closure contained within f.
-func containsClosure(f, c *ir.Func) bool {
-	// Common case.
-	if f == c {
-		return false
-	}
-
-	// Closures within function Foo are named like "Foo.funcN..."
-	// TODO(mdempsky): Better way to recognize this.
-	fn := f.Sym().Name
-	cn := c.Sym().Name
-	return len(cn) > len(fn) && cn[:len(fn)] == fn && cn[len(fn)] == '.'
-}
-
-// leak records that parameter l leaks to sink.
-func (l *location) leakTo(sink *location, derefs int) {
-	// If sink is a result parameter that doesn't escape (#44614)
-	// and we can fit return bits into the escape analysis tag,
-	// then record as a result leak.
-	if !sink.escapes && sink.isName(ir.PPARAMOUT) && sink.curfn == l.curfn {
-		ri := sink.resultIndex - 1
-		if ri < numEscResults {
-			// Leak to result parameter.
-			l.paramEsc.AddResult(ri, derefs)
-			return
-		}
-	}
-
-	// Otherwise, record as heap leak.
-	l.paramEsc.AddHeap(derefs)
-}
-
 func (b *batch) finish(fns []*ir.Func) {
 	// Record parameter tags for package export data.
 	for _, fn := range fns {
@@ -1678,6 +288,11 @@ func (b *batch) finish(fns []*ir.Func) {
 
 		// Update n.Esc based on escape analysis results.
 
+		// Omit escape diagnostics for go/defer wrappers, at least for now.
+		// Historically, we haven't printed them, and test cases don't expect them.
+		// TODO(mdempsky): Update tests to expect this.
+		goDeferWrapper := n.Op() == ir.OCLOSURE && n.(*ir.ClosureExpr).Func.Wrapper()
+
 		if loc.escapes {
 			if n.Op() == ir.ONAME {
 				if base.Flag.CompilingRuntime {
@@ -1687,7 +302,7 @@ func (b *batch) finish(fns []*ir.Func) {
 					base.WarnfAt(n.Pos(), "moved to heap: %v", n)
 				}
 			} else {
-				if base.Flag.LowerM != 0 {
+				if base.Flag.LowerM != 0 && !goDeferWrapper {
 					base.WarnfAt(n.Pos(), "%v escapes to heap", n)
 				}
 				if logopt.Enabled() {
@@ -1697,7 +312,7 @@ func (b *batch) finish(fns []*ir.Func) {
 			}
 			n.SetEsc(ir.EscHeap)
 		} else {
-			if base.Flag.LowerM != 0 && n.Op() != ir.ONAME {
+			if base.Flag.LowerM != 0 && n.Op() != ir.ONAME && !goDeferWrapper {
 				base.WarnfAt(n.Pos(), "%v does not escape", n)
 			}
 			n.SetEsc(ir.EscNone)
@@ -1706,7 +321,7 @@ func (b *batch) finish(fns []*ir.Func) {
 				case ir.OCLOSURE:
 					n := n.(*ir.ClosureExpr)
 					n.SetTransient(true)
-				case ir.OCALLPART:
+				case ir.OMETHVALUE:
 					n := n.(*ir.SelectorExpr)
 					n.SetTransient(true)
 				case ir.OSLICELIT:
@@ -1718,107 +333,19 @@ func (b *batch) finish(fns []*ir.Func) {
 	}
 }
 
-func (l *location) isName(c ir.Class) bool {
-	return l.n != nil && l.n.Op() == ir.ONAME && l.n.(*ir.Name).Class == c
-}
-
-const numEscResults = 7
-
-// An leaks represents a set of assignment flows from a parameter
-// to the heap or to any of its function's (first numEscResults)
-// result parameters.
-type leaks [1 + numEscResults]uint8
-
-// Empty reports whether l is an empty set (i.e., no assignment flows).
-func (l leaks) Empty() bool { return l == leaks{} }
-
-// Heap returns the minimum deref count of any assignment flow from l
-// to the heap. If no such flows exist, Heap returns -1.
-func (l leaks) Heap() int { return l.get(0) }
-
-// Result returns the minimum deref count of any assignment flow from
-// l to its function's i'th result parameter. If no such flows exist,
-// Result returns -1.
-func (l leaks) Result(i int) int { return l.get(1 + i) }
-
-// AddHeap adds an assignment flow from l to the heap.
-func (l *leaks) AddHeap(derefs int) { l.add(0, derefs) }
-
-// AddResult adds an assignment flow from l to its function's i'th
-// result parameter.
-func (l *leaks) AddResult(i, derefs int) { l.add(1+i, derefs) }
-
-func (l *leaks) setResult(i, derefs int) { l.set(1+i, derefs) }
-
-func (l leaks) get(i int) int { return int(l[i]) - 1 }
-
-func (l *leaks) add(i, derefs int) {
-	if old := l.get(i); old < 0 || derefs < old {
-		l.set(i, derefs)
-	}
-}
-
-func (l *leaks) set(i, derefs int) {
-	v := derefs + 1
-	if v < 0 {
-		base.Fatalf("invalid derefs count: %v", derefs)
-	}
-	if v > math.MaxUint8 {
-		v = math.MaxUint8
-	}
-
-	l[i] = uint8(v)
-}
-
-// Optimize removes result flow paths that are equal in length or
-// longer than the shortest heap flow path.
-func (l *leaks) Optimize() {
-	// If we have a path to the heap, then there's no use in
-	// keeping equal or longer paths elsewhere.
-	if x := l.Heap(); x >= 0 {
-		for i := 0; i < numEscResults; i++ {
-			if l.Result(i) >= x {
-				l.setResult(i, -1)
-			}
+// inMutualBatch reports whether function fn is in the batch of
+// mutually recursive functions being analyzed. When this is true,
+// fn has not yet been analyzed, so its parameters and results
+// should be incorporated directly into the flow graph instead of
+// relying on its escape analysis tagging.
+func (e *escape) inMutualBatch(fn *ir.Name) bool {
+	if fn.Defn != nil && fn.Defn.Esc() < escFuncTagged {
+		if fn.Defn.Esc() == escFuncUnknown {
+			base.Fatalf("graph inconsistency: %v", fn)
 		}
+		return true
 	}
-}
-
-var leakTagCache = map[leaks]string{}
-
-// Encode converts l into a binary string for export data.
-func (l leaks) Encode() string {
-	if l.Heap() == 0 {
-		// Space optimization: empty string encodes more
-		// efficiently in export data.
-		return ""
-	}
-	if s, ok := leakTagCache[l]; ok {
-		return s
-	}
-
-	n := len(l)
-	for n > 0 && l[n-1] == 0 {
-		n--
-	}
-	s := "esc:" + string(l[:n])
-	leakTagCache[l] = s
-	return s
-}
-
-// parseLeaks parses a binary string representing a leaks
-func parseLeaks(s string) leaks {
-	var l leaks
-	if !strings.HasPrefix(s, "esc:") {
-		l.AddHeap(0)
-		return l
-	}
-	copy(l[:], s[4:])
-	return l
-}
-
-func Funcs(all []ir.Node) {
-	ir.VisitFuncsBottomUp(all, Batch)
+	return false
 }
 
 const (
@@ -1836,220 +363,6 @@ const (
 	nonlooping
 )
 
-func isSliceSelfAssign(dst, src ir.Node) bool {
-	// Detect the following special case.
-	//
-	//	func (b *Buffer) Foo() {
-	//		n, m := ...
-	//		b.buf = b.buf[n:m]
-	//	}
-	//
-	// This assignment is a no-op for escape analysis,
-	// it does not store any new pointers into b that were not already there.
-	// However, without this special case b will escape, because we assign to OIND/ODOTPTR.
-	// Here we assume that the statement will not contain calls,
-	// that is, that order will move any calls to init.
-	// Otherwise base ONAME value could change between the moments
-	// when we evaluate it for dst and for src.
-
-	// dst is ONAME dereference.
-	var dstX ir.Node
-	switch dst.Op() {
-	default:
-		return false
-	case ir.ODEREF:
-		dst := dst.(*ir.StarExpr)
-		dstX = dst.X
-	case ir.ODOTPTR:
-		dst := dst.(*ir.SelectorExpr)
-		dstX = dst.X
-	}
-	if dstX.Op() != ir.ONAME {
-		return false
-	}
-	// src is a slice operation.
-	switch src.Op() {
-	case ir.OSLICE, ir.OSLICE3, ir.OSLICESTR:
-		// OK.
-	case ir.OSLICEARR, ir.OSLICE3ARR:
-		// Since arrays are embedded into containing object,
-		// slice of non-pointer array will introduce a new pointer into b that was not already there
-		// (pointer to b itself). After such assignment, if b contents escape,
-		// b escapes as well. If we ignore such OSLICEARR, we will conclude
-		// that b does not escape when b contents do.
-		//
-		// Pointer to an array is OK since it's not stored inside b directly.
-		// For slicing an array (not pointer to array), there is an implicit OADDR.
-		// We check that to determine non-pointer array slicing.
-		src := src.(*ir.SliceExpr)
-		if src.X.Op() == ir.OADDR {
-			return false
-		}
-	default:
-		return false
-	}
-	// slice is applied to ONAME dereference.
-	var baseX ir.Node
-	switch base := src.(*ir.SliceExpr).X; base.Op() {
-	default:
-		return false
-	case ir.ODEREF:
-		base := base.(*ir.StarExpr)
-		baseX = base.X
-	case ir.ODOTPTR:
-		base := base.(*ir.SelectorExpr)
-		baseX = base.X
-	}
-	if baseX.Op() != ir.ONAME {
-		return false
-	}
-	// dst and src reference the same base ONAME.
-	return dstX.(*ir.Name) == baseX.(*ir.Name)
-}
-
-// isSelfAssign reports whether assignment from src to dst can
-// be ignored by the escape analysis as it's effectively a self-assignment.
-func isSelfAssign(dst, src ir.Node) bool {
-	if isSliceSelfAssign(dst, src) {
-		return true
-	}
-
-	// Detect trivial assignments that assign back to the same object.
-	//
-	// It covers these cases:
-	//	val.x = val.y
-	//	val.x[i] = val.y[j]
-	//	val.x1.x2 = val.x1.y2
-	//	... etc
-	//
-	// These assignments do not change assigned object lifetime.
-
-	if dst == nil || src == nil || dst.Op() != src.Op() {
-		return false
-	}
-
-	// The expression prefix must be both "safe" and identical.
-	switch dst.Op() {
-	case ir.ODOT, ir.ODOTPTR:
-		// Safe trailing accessors that are permitted to differ.
-		dst := dst.(*ir.SelectorExpr)
-		src := src.(*ir.SelectorExpr)
-		return ir.SameSafeExpr(dst.X, src.X)
-	case ir.OINDEX:
-		dst := dst.(*ir.IndexExpr)
-		src := src.(*ir.IndexExpr)
-		if mayAffectMemory(dst.Index) || mayAffectMemory(src.Index) {
-			return false
-		}
-		return ir.SameSafeExpr(dst.X, src.X)
-	default:
-		return false
-	}
-}
-
-// mayAffectMemory reports whether evaluation of n may affect the program's
-// memory state. If the expression can't affect memory state, then it can be
-// safely ignored by the escape analysis.
-func mayAffectMemory(n ir.Node) bool {
-	// We may want to use a list of "memory safe" ops instead of generally
-	// "side-effect free", which would include all calls and other ops that can
-	// allocate or change global state. For now, it's safer to start with the latter.
-	//
-	// We're ignoring things like division by zero, index out of range,
-	// and nil pointer dereference here.
-
-	// TODO(rsc): It seems like it should be possible to replace this with
-	// an ir.Any looking for any op that's not the ones in the case statement.
-	// But that produces changes in the compiled output detected by buildall.
-	switch n.Op() {
-	case ir.ONAME, ir.OLITERAL, ir.ONIL:
-		return false
-
-	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.OLSH, ir.ORSH, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OMOD:
-		n := n.(*ir.BinaryExpr)
-		return mayAffectMemory(n.X) || mayAffectMemory(n.Y)
-
-	case ir.OINDEX:
-		n := n.(*ir.IndexExpr)
-		return mayAffectMemory(n.X) || mayAffectMemory(n.Index)
-
-	case ir.OCONVNOP, ir.OCONV:
-		n := n.(*ir.ConvExpr)
-		return mayAffectMemory(n.X)
-
-	case ir.OLEN, ir.OCAP, ir.ONOT, ir.OBITNOT, ir.OPLUS, ir.ONEG, ir.OALIGNOF, ir.OOFFSETOF, ir.OSIZEOF:
-		n := n.(*ir.UnaryExpr)
-		return mayAffectMemory(n.X)
-
-	case ir.ODOT, ir.ODOTPTR:
-		n := n.(*ir.SelectorExpr)
-		return mayAffectMemory(n.X)
-
-	case ir.ODEREF:
-		n := n.(*ir.StarExpr)
-		return mayAffectMemory(n.X)
-
-	default:
-		return true
-	}
-}
-
-// HeapAllocReason returns the reason the given Node must be heap
-// allocated, or the empty string if it doesn't.
-func HeapAllocReason(n ir.Node) string {
-	if n == nil || n.Type() == nil {
-		return ""
-	}
-
-	// Parameters are always passed via the stack.
-	if n.Op() == ir.ONAME {
-		n := n.(*ir.Name)
-		if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
-			return ""
-		}
-	}
-
-	if n.Type().Width > ir.MaxStackVarSize {
-		return "too large for stack"
-	}
-
-	if (n.Op() == ir.ONEW || n.Op() == ir.OPTRLIT) && n.Type().Elem().Width >= ir.MaxImplicitStackVarSize {
-		return "too large for stack"
-	}
-
-	if n.Op() == ir.OCLOSURE && typecheck.ClosureType(n.(*ir.ClosureExpr)).Size() >= ir.MaxImplicitStackVarSize {
-		return "too large for stack"
-	}
-	if n.Op() == ir.OCALLPART && typecheck.PartialCallType(n.(*ir.SelectorExpr)).Size() >= ir.MaxImplicitStackVarSize {
-		return "too large for stack"
-	}
-
-	if n.Op() == ir.OMAKESLICE {
-		n := n.(*ir.MakeExpr)
-		r := n.Cap
-		if r == nil {
-			r = n.Len
-		}
-		if !ir.IsSmallIntConst(r) {
-			return "non-constant size"
-		}
-		if t := n.Type(); t.Elem().Width != 0 && ir.Int64Val(r) >= ir.MaxImplicitStackVarSize/t.Elem().Width {
-			return "too large for stack"
-		}
-	}
-
-	return ""
-}
-
-// This special tag is applied to uintptr variables
-// that we believe may hold unsafe.Pointers for
-// calls into assembly functions.
-const UnsafeUintptrNote = "unsafe-uintptr"
-
-// This special tag is applied to uintptr parameters of functions
-// marked go:uintptrescapes.
-const UintptrEscapesNote = "uintptr-escapes"
-
 func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 	name := func() string {
 		if f.Sym != nil {
@@ -2058,6 +371,11 @@ func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 		return fmt.Sprintf("arg#%d", narg)
 	}
 
+	// Only report diagnostics for user code;
+	// not for wrappers generated around them.
+	// TODO(mdempsky): Generalize this.
+	diagnose := base.Flag.LowerM != 0 && !(fn.Wrapper() || fn.Dupok())
+
 	if len(fn.Body) == 0 {
 		// Assume that uintptr arguments must be held live across the call.
 		// This is most important for syscall.Syscall.
@@ -2065,11 +383,13 @@ func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 		// This really doesn't have much to do with escape analysis per se,
 		// but we are reusing the ability to annotate an individual function
 		// argument and pass those annotations along to importing code.
+		fn.Pragma |= ir.UintptrKeepAlive
+
 		if f.Type.IsUintptr() {
-			if base.Flag.LowerM != 0 {
+			if diagnose {
 				base.WarnfAt(f.Pos, "assuming %v is unsafe uintptr", name())
 			}
-			return UnsafeUintptrNote
+			return ""
 		}
 
 		if !f.Type.HasPointers() { // don't bother tagging for scalars
@@ -2081,11 +401,11 @@ func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 		// External functions are assumed unsafe, unless
 		// //go:noescape is given before the declaration.
 		if fn.Pragma&ir.Noescape != 0 {
-			if base.Flag.LowerM != 0 && f.Sym != nil {
+			if diagnose && f.Sym != nil {
 				base.WarnfAt(f.Pos, "%v does not escape", name())
 			}
 		} else {
-			if base.Flag.LowerM != 0 && f.Sym != nil {
+			if diagnose && f.Sym != nil {
 				base.WarnfAt(f.Pos, "leaking param: %v", name())
 			}
 			esc.AddHeap(0)
@@ -2095,18 +415,20 @@ func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 	}
 
 	if fn.Pragma&ir.UintptrEscapes != 0 {
+		fn.Pragma |= ir.UintptrKeepAlive
+
 		if f.Type.IsUintptr() {
-			if base.Flag.LowerM != 0 {
+			if diagnose {
 				base.WarnfAt(f.Pos, "marking %v as escaping uintptr", name())
 			}
-			return UintptrEscapesNote
+			return ""
 		}
 		if f.IsDDD() && f.Type.Elem().IsUintptr() {
 			// final argument is ...uintptr.
-			if base.Flag.LowerM != 0 {
+			if diagnose {
 				base.WarnfAt(f.Pos, "marking %v as escaping ...uintptr", name())
 			}
-			return UintptrEscapesNote
+			return ""
 		}
 	}
 
@@ -2125,7 +447,7 @@ func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 	esc := loc.paramEsc
 	esc.Optimize()
 
-	if base.Flag.LowerM != 0 && !loc.escapes {
+	if diagnose && !loc.escapes {
 		if esc.Empty() {
 			base.WarnfAt(f.Pos, "%v does not escape", name())
 		}
diff --git a/src/cmd/compile/internal/escape/expr.go b/src/cmd/compile/internal/escape/expr.go
new file mode 100644
index 00000000000..62afb5b9288
--- /dev/null
+++ b/src/cmd/compile/internal/escape/expr.go
@@ -0,0 +1,335 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/types"
+)
+
+// expr models evaluating an expression n and flowing the result into
+// hole k.
+func (e *escape) expr(k hole, n ir.Node) {
+	if n == nil {
+		return
+	}
+	e.stmts(n.Init())
+	e.exprSkipInit(k, n)
+}
+
+func (e *escape) exprSkipInit(k hole, n ir.Node) {
+	if n == nil {
+		return
+	}
+
+	lno := ir.SetPos(n)
+	defer func() {
+		base.Pos = lno
+	}()
+
+	if k.derefs >= 0 && !n.Type().HasPointers() {
+		k.dst = &e.blankLoc
+	}
+
+	switch n.Op() {
+	default:
+		base.Fatalf("unexpected expr: %s %v", n.Op().String(), n)
+
+	case ir.OLITERAL, ir.ONIL, ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP, ir.OTYPE, ir.OMETHEXPR, ir.OLINKSYMOFFSET:
+		// nop
+
+	case ir.ONAME:
+		n := n.(*ir.Name)
+		if n.Class == ir.PFUNC || n.Class == ir.PEXTERN {
+			return
+		}
+		e.flow(k, e.oldLoc(n))
+
+	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT:
+		n := n.(*ir.UnaryExpr)
+		e.discard(n.X)
+	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.ODIV, ir.OMOD, ir.OLSH, ir.ORSH, ir.OAND, ir.OANDNOT, ir.OEQ, ir.ONE, ir.OLT, ir.OLE, ir.OGT, ir.OGE:
+		n := n.(*ir.BinaryExpr)
+		e.discard(n.X)
+		e.discard(n.Y)
+	case ir.OANDAND, ir.OOROR:
+		n := n.(*ir.LogicalExpr)
+		e.discard(n.X)
+		e.discard(n.Y)
+	case ir.OADDR:
+		n := n.(*ir.AddrExpr)
+		e.expr(k.addr(n, "address-of"), n.X) // "address-of"
+	case ir.ODEREF:
+		n := n.(*ir.StarExpr)
+		e.expr(k.deref(n, "indirection"), n.X) // "indirection"
+	case ir.ODOT, ir.ODOTMETH, ir.ODOTINTER:
+		n := n.(*ir.SelectorExpr)
+		e.expr(k.note(n, "dot"), n.X)
+	case ir.ODOTPTR:
+		n := n.(*ir.SelectorExpr)
+		e.expr(k.deref(n, "dot of pointer"), n.X) // "dot of pointer"
+	case ir.ODOTTYPE, ir.ODOTTYPE2:
+		n := n.(*ir.TypeAssertExpr)
+		e.expr(k.dotType(n.Type(), n, "dot"), n.X)
+	case ir.ODYNAMICDOTTYPE, ir.ODYNAMICDOTTYPE2:
+		n := n.(*ir.DynamicTypeAssertExpr)
+		e.expr(k.dotType(n.Type(), n, "dot"), n.X)
+		// n.T doesn't need to be tracked; it always points to read-only storage.
+	case ir.OINDEX:
+		n := n.(*ir.IndexExpr)
+		if n.X.Type().IsArray() {
+			e.expr(k.note(n, "fixed-array-index-of"), n.X)
+		} else {
+			// TODO(mdempsky): Fix why reason text.
+			e.expr(k.deref(n, "dot of pointer"), n.X)
+		}
+		e.discard(n.Index)
+	case ir.OINDEXMAP:
+		n := n.(*ir.IndexExpr)
+		e.discard(n.X)
+		e.discard(n.Index)
+	case ir.OSLICE, ir.OSLICEARR, ir.OSLICE3, ir.OSLICE3ARR, ir.OSLICESTR:
+		n := n.(*ir.SliceExpr)
+		e.expr(k.note(n, "slice"), n.X)
+		e.discard(n.Low)
+		e.discard(n.High)
+		e.discard(n.Max)
+
+	case ir.OCONV, ir.OCONVNOP:
+		n := n.(*ir.ConvExpr)
+		if ir.ShouldCheckPtr(e.curfn, 2) && n.Type().IsUnsafePtr() && n.X.Type().IsPtr() {
+			// When -d=checkptr=2 is enabled, treat
+			// conversions to unsafe.Pointer as an
+			// escaping operation. This allows better
+			// runtime instrumentation, since we can more
+			// easily detect object boundaries on the heap
+			// than the stack.
+			e.assignHeap(n.X, "conversion to unsafe.Pointer", n)
+		} else if n.Type().IsUnsafePtr() && n.X.Type().IsUintptr() {
+			e.unsafeValue(k, n.X)
+		} else {
+			e.expr(k, n.X)
+		}
+	case ir.OCONVIFACE, ir.OCONVIDATA:
+		n := n.(*ir.ConvExpr)
+		if !n.X.Type().IsInterface() && !types.IsDirectIface(n.X.Type()) {
+			k = e.spill(k, n)
+		}
+		e.expr(k.note(n, "interface-converted"), n.X)
+	case ir.OEFACE:
+		n := n.(*ir.BinaryExpr)
+		// Note: n.X is not needed because it can never point to memory that might escape.
+		e.expr(k, n.Y)
+	case ir.OIDATA, ir.OSPTR:
+		n := n.(*ir.UnaryExpr)
+		e.expr(k, n.X)
+	case ir.OSLICE2ARRPTR:
+		// the slice pointer flows directly to the result
+		n := n.(*ir.ConvExpr)
+		e.expr(k, n.X)
+	case ir.ORECV:
+		n := n.(*ir.UnaryExpr)
+		e.discard(n.X)
+
+	case ir.OCALLMETH, ir.OCALLFUNC, ir.OCALLINTER, ir.OINLCALL, ir.OLEN, ir.OCAP, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY, ir.ORECOVER, ir.OUNSAFEADD, ir.OUNSAFESLICE:
+		e.call([]hole{k}, n)
+
+	case ir.ONEW:
+		n := n.(*ir.UnaryExpr)
+		e.spill(k, n)
+
+	case ir.OMAKESLICE:
+		n := n.(*ir.MakeExpr)
+		e.spill(k, n)
+		e.discard(n.Len)
+		e.discard(n.Cap)
+	case ir.OMAKECHAN:
+		n := n.(*ir.MakeExpr)
+		e.discard(n.Len)
+	case ir.OMAKEMAP:
+		n := n.(*ir.MakeExpr)
+		e.spill(k, n)
+		e.discard(n.Len)
+
+	case ir.OMETHVALUE:
+		// Flow the receiver argument to both the closure and
+		// to the receiver parameter.
+
+		n := n.(*ir.SelectorExpr)
+		closureK := e.spill(k, n)
+
+		m := n.Selection
+
+		// We don't know how the method value will be called
+		// later, so conservatively assume the result
+		// parameters all flow to the heap.
+		//
+		// TODO(mdempsky): Change ks into a callback, so that
+		// we don't have to create this slice?
+		var ks []hole
+		for i := m.Type.NumResults(); i > 0; i-- {
+			ks = append(ks, e.heapHole())
+		}
+		name, _ := m.Nname.(*ir.Name)
+		paramK := e.tagHole(ks, name, m.Type.Recv())
+
+		e.expr(e.teeHole(paramK, closureK), n.X)
+
+	case ir.OPTRLIT:
+		n := n.(*ir.AddrExpr)
+		e.expr(e.spill(k, n), n.X)
+
+	case ir.OARRAYLIT:
+		n := n.(*ir.CompLitExpr)
+		for _, elt := range n.List {
+			if elt.Op() == ir.OKEY {
+				elt = elt.(*ir.KeyExpr).Value
+			}
+			e.expr(k.note(n, "array literal element"), elt)
+		}
+
+	case ir.OSLICELIT:
+		n := n.(*ir.CompLitExpr)
+		k = e.spill(k, n)
+
+		for _, elt := range n.List {
+			if elt.Op() == ir.OKEY {
+				elt = elt.(*ir.KeyExpr).Value
+			}
+			e.expr(k.note(n, "slice-literal-element"), elt)
+		}
+
+	case ir.OSTRUCTLIT:
+		n := n.(*ir.CompLitExpr)
+		for _, elt := range n.List {
+			e.expr(k.note(n, "struct literal element"), elt.(*ir.StructKeyExpr).Value)
+		}
+
+	case ir.OMAPLIT:
+		n := n.(*ir.CompLitExpr)
+		e.spill(k, n)
+
+		// Map keys and values are always stored in the heap.
+		for _, elt := range n.List {
+			elt := elt.(*ir.KeyExpr)
+			e.assignHeap(elt.Key, "map literal key", n)
+			e.assignHeap(elt.Value, "map literal value", n)
+		}
+
+	case ir.OCLOSURE:
+		n := n.(*ir.ClosureExpr)
+		k = e.spill(k, n)
+		e.closures = append(e.closures, closure{k, n})
+
+		if fn := n.Func; fn.IsHiddenClosure() {
+			for _, cv := range fn.ClosureVars {
+				if loc := e.oldLoc(cv); !loc.captured {
+					loc.captured = true
+
+					// Ignore reassignments to the variable in straightline code
+					// preceding the first capture by a closure.
+					if loc.loopDepth == e.loopDepth {
+						loc.reassigned = false
+					}
+				}
+			}
+
+			for _, n := range fn.Dcl {
+				// Add locations for local variables of the
+				// closure, if needed, in case we're not including
+				// the closure func in the batch for escape
+				// analysis (happens for escape analysis called
+				// from reflectdata.methodWrapper)
+				if n.Op() == ir.ONAME && n.Opt == nil {
+					e.with(fn).newLoc(n, false)
+				}
+			}
+			e.walkFunc(fn)
+		}
+
+	case ir.ORUNES2STR, ir.OBYTES2STR, ir.OSTR2RUNES, ir.OSTR2BYTES, ir.ORUNESTR:
+		n := n.(*ir.ConvExpr)
+		e.spill(k, n)
+		e.discard(n.X)
+
+	case ir.OADDSTR:
+		n := n.(*ir.AddStringExpr)
+		e.spill(k, n)
+
+		// Arguments of OADDSTR never escape;
+		// runtime.concatstrings makes sure of that.
+		e.discards(n.List)
+
+	case ir.ODYNAMICTYPE:
+		// Nothing to do - argument is a *runtime._type (+ maybe a *runtime.itab) pointing to static data section
+	}
+}
+
+// unsafeValue evaluates a uintptr-typed arithmetic expression looking
+// for conversions from an unsafe.Pointer.
+func (e *escape) unsafeValue(k hole, n ir.Node) {
+	if n.Type().Kind() != types.TUINTPTR {
+		base.Fatalf("unexpected type %v for %v", n.Type(), n)
+	}
+	if k.addrtaken {
+		base.Fatalf("unexpected addrtaken")
+	}
+
+	e.stmts(n.Init())
+
+	switch n.Op() {
+	case ir.OCONV, ir.OCONVNOP:
+		n := n.(*ir.ConvExpr)
+		if n.X.Type().IsUnsafePtr() {
+			e.expr(k, n.X)
+		} else {
+			e.discard(n.X)
+		}
+	case ir.ODOTPTR:
+		n := n.(*ir.SelectorExpr)
+		if ir.IsReflectHeaderDataField(n) {
+			e.expr(k.deref(n, "reflect.Header.Data"), n.X)
+		} else {
+			e.discard(n.X)
+		}
+	case ir.OPLUS, ir.ONEG, ir.OBITNOT:
+		n := n.(*ir.UnaryExpr)
+		e.unsafeValue(k, n.X)
+	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.ODIV, ir.OMOD, ir.OAND, ir.OANDNOT:
+		n := n.(*ir.BinaryExpr)
+		e.unsafeValue(k, n.X)
+		e.unsafeValue(k, n.Y)
+	case ir.OLSH, ir.ORSH:
+		n := n.(*ir.BinaryExpr)
+		e.unsafeValue(k, n.X)
+		// RHS need not be uintptr-typed (#32959) and can't meaningfully
+		// flow pointers anyway.
+		e.discard(n.Y)
+	default:
+		e.exprSkipInit(e.discardHole(), n)
+	}
+}
+
+// discard evaluates an expression n for side-effects, but discards
+// its value.
+func (e *escape) discard(n ir.Node) {
+	e.expr(e.discardHole(), n)
+}
+
+func (e *escape) discards(l ir.Nodes) {
+	for _, n := range l {
+		e.discard(n)
+	}
+}
+
+// spill allocates a new location associated with expression n, flows
+// its address to k, and returns a hole that flows values to it. It's
+// intended for use with most expressions that allocate storage.
+func (e *escape) spill(k hole, n ir.Node) hole {
+	loc := e.newLoc(n, true)
+	e.flow(k.addr(n, "spill"), loc)
+	return loc.asHole()
+}
diff --git a/src/cmd/compile/internal/escape/graph.go b/src/cmd/compile/internal/escape/graph.go
new file mode 100644
index 00000000000..d3ae1da693e
--- /dev/null
+++ b/src/cmd/compile/internal/escape/graph.go
@@ -0,0 +1,324 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/logopt"
+	"cmd/compile/internal/types"
+	"fmt"
+)
+
+// Below we implement the methods for walking the AST and recording
+// data flow edges. Note that because a sub-expression might have
+// side-effects, it's important to always visit the entire AST.
+//
+// For example, write either:
+//
+//     if x {
+//         e.discard(n.Left)
+//     } else {
+//         e.value(k, n.Left)
+//     }
+//
+// or
+//
+//     if x {
+//         k = e.discardHole()
+//     }
+//     e.value(k, n.Left)
+//
+// Do NOT write:
+//
+//    // BAD: possibly loses side-effects within n.Left
+//    if !x {
+//        e.value(k, n.Left)
+//    }
+
+// An location represents an abstract location that stores a Go
+// variable.
+type location struct {
+	n         ir.Node  // represented variable or expression, if any
+	curfn     *ir.Func // enclosing function
+	edges     []edge   // incoming edges
+	loopDepth int      // loopDepth at declaration
+
+	// resultIndex records the tuple index (starting at 1) for
+	// PPARAMOUT variables within their function's result type.
+	// For non-PPARAMOUT variables it's 0.
+	resultIndex int
+
+	// derefs and walkgen are used during walkOne to track the
+	// minimal dereferences from the walk root.
+	derefs  int // >= -1
+	walkgen uint32
+
+	// dst and dstEdgeindex track the next immediate assignment
+	// destination location during walkone, along with the index
+	// of the edge pointing back to this location.
+	dst        *location
+	dstEdgeIdx int
+
+	// queued is used by walkAll to track whether this location is
+	// in the walk queue.
+	queued bool
+
+	// escapes reports whether the represented variable's address
+	// escapes; that is, whether the variable must be heap
+	// allocated.
+	escapes bool
+
+	// transient reports whether the represented expression's
+	// address does not outlive the statement; that is, whether
+	// its storage can be immediately reused.
+	transient bool
+
+	// paramEsc records the represented parameter's leak set.
+	paramEsc leaks
+
+	captured   bool // has a closure captured this variable?
+	reassigned bool // has this variable been reassigned?
+	addrtaken  bool // has this variable's address been taken?
+}
+
+// An edge represents an assignment edge between two Go variables.
+type edge struct {
+	src    *location
+	derefs int // >= -1
+	notes  *note
+}
+
+func (l *location) asHole() hole {
+	return hole{dst: l}
+}
+
+// leak records that parameter l leaks to sink.
+func (l *location) leakTo(sink *location, derefs int) {
+	// If sink is a result parameter that doesn't escape (#44614)
+	// and we can fit return bits into the escape analysis tag,
+	// then record as a result leak.
+	if !sink.escapes && sink.isName(ir.PPARAMOUT) && sink.curfn == l.curfn {
+		ri := sink.resultIndex - 1
+		if ri < numEscResults {
+			// Leak to result parameter.
+			l.paramEsc.AddResult(ri, derefs)
+			return
+		}
+	}
+
+	// Otherwise, record as heap leak.
+	l.paramEsc.AddHeap(derefs)
+}
+
+func (l *location) isName(c ir.Class) bool {
+	return l.n != nil && l.n.Op() == ir.ONAME && l.n.(*ir.Name).Class == c
+}
+
+// An hole represents a context for evaluation a Go
+// expression. E.g., when evaluating p in "x = **p", we'd have a hole
+// with dst==x and derefs==2.
+type hole struct {
+	dst    *location
+	derefs int // >= -1
+	notes  *note
+
+	// addrtaken indicates whether this context is taking the address of
+	// the expression, independent of whether the address will actually
+	// be stored into a variable.
+	addrtaken bool
+}
+
+type note struct {
+	next  *note
+	where ir.Node
+	why   string
+}
+
+func (k hole) note(where ir.Node, why string) hole {
+	if where == nil || why == "" {
+		base.Fatalf("note: missing where/why")
+	}
+	if base.Flag.LowerM >= 2 || logopt.Enabled() {
+		k.notes = ¬e{
+			next:  k.notes,
+			where: where,
+			why:   why,
+		}
+	}
+	return k
+}
+
+func (k hole) shift(delta int) hole {
+	k.derefs += delta
+	if k.derefs < -1 {
+		base.Fatalf("derefs underflow: %v", k.derefs)
+	}
+	k.addrtaken = delta < 0
+	return k
+}
+
+func (k hole) deref(where ir.Node, why string) hole { return k.shift(1).note(where, why) }
+func (k hole) addr(where ir.Node, why string) hole  { return k.shift(-1).note(where, why) }
+
+func (k hole) dotType(t *types.Type, where ir.Node, why string) hole {
+	if !t.IsInterface() && !types.IsDirectIface(t) {
+		k = k.shift(1)
+	}
+	return k.note(where, why)
+}
+
+func (b *batch) flow(k hole, src *location) {
+	if k.addrtaken {
+		src.addrtaken = true
+	}
+
+	dst := k.dst
+	if dst == &b.blankLoc {
+		return
+	}
+	if dst == src && k.derefs >= 0 { // dst = dst, dst = *dst, ...
+		return
+	}
+	if dst.escapes && k.derefs < 0 { // dst = &src
+		if base.Flag.LowerM >= 2 || logopt.Enabled() {
+			pos := base.FmtPos(src.n.Pos())
+			if base.Flag.LowerM >= 2 {
+				fmt.Printf("%s: %v escapes to heap:\n", pos, src.n)
+			}
+			explanation := b.explainFlow(pos, dst, src, k.derefs, k.notes, []*logopt.LoggedOpt{})
+			if logopt.Enabled() {
+				var e_curfn *ir.Func // TODO(mdempsky): Fix.
+				logopt.LogOpt(src.n.Pos(), "escapes", "escape", ir.FuncName(e_curfn), fmt.Sprintf("%v escapes to heap", src.n), explanation)
+			}
+
+		}
+		src.escapes = true
+		return
+	}
+
+	// TODO(mdempsky): Deduplicate edges?
+	dst.edges = append(dst.edges, edge{src: src, derefs: k.derefs, notes: k.notes})
+}
+
+func (b *batch) heapHole() hole    { return b.heapLoc.asHole() }
+func (b *batch) discardHole() hole { return b.blankLoc.asHole() }
+
+func (b *batch) oldLoc(n *ir.Name) *location {
+	if n.Canonical().Opt == nil {
+		base.Fatalf("%v has no location", n)
+	}
+	return n.Canonical().Opt.(*location)
+}
+
+func (e *escape) newLoc(n ir.Node, transient bool) *location {
+	if e.curfn == nil {
+		base.Fatalf("e.curfn isn't set")
+	}
+	if n != nil && n.Type() != nil && n.Type().NotInHeap() {
+		base.ErrorfAt(n.Pos(), "%v is incomplete (or unallocatable); stack allocation disallowed", n.Type())
+	}
+
+	if n != nil && n.Op() == ir.ONAME {
+		if canon := n.(*ir.Name).Canonical(); n != canon {
+			base.Fatalf("newLoc on non-canonical %v (canonical is %v)", n, canon)
+		}
+	}
+	loc := &location{
+		n:         n,
+		curfn:     e.curfn,
+		loopDepth: e.loopDepth,
+		transient: transient,
+	}
+	e.allLocs = append(e.allLocs, loc)
+	if n != nil {
+		if n.Op() == ir.ONAME {
+			n := n.(*ir.Name)
+			if n.Class == ir.PPARAM && n.Curfn == nil {
+				// ok; hidden parameter
+			} else if n.Curfn != e.curfn {
+				base.Fatalf("curfn mismatch: %v != %v for %v", n.Curfn, e.curfn, n)
+			}
+
+			if n.Opt != nil {
+				base.Fatalf("%v already has a location", n)
+			}
+			n.Opt = loc
+		}
+	}
+	return loc
+}
+
+// teeHole returns a new hole that flows into each hole of ks,
+// similar to the Unix tee(1) command.
+func (e *escape) teeHole(ks ...hole) hole {
+	if len(ks) == 0 {
+		return e.discardHole()
+	}
+	if len(ks) == 1 {
+		return ks[0]
+	}
+	// TODO(mdempsky): Optimize if there's only one non-discard hole?
+
+	// Given holes "l1 = _", "l2 = **_", "l3 = *_", ..., create a
+	// new temporary location ltmp, wire it into place, and return
+	// a hole for "ltmp = _".
+	loc := e.newLoc(nil, true)
+	for _, k := range ks {
+		// N.B., "p = &q" and "p = &tmp; tmp = q" are not
+		// semantically equivalent. To combine holes like "l1
+		// = _" and "l2 = &_", we'd need to wire them as "l1 =
+		// *ltmp" and "l2 = ltmp" and return "ltmp = &_"
+		// instead.
+		if k.derefs < 0 {
+			base.Fatalf("teeHole: negative derefs")
+		}
+
+		e.flow(k, loc)
+	}
+	return loc.asHole()
+}
+
+// later returns a new hole that flows into k, but some time later.
+// Its main effect is to prevent immediate reuse of temporary
+// variables introduced during Order.
+func (e *escape) later(k hole) hole {
+	loc := e.newLoc(nil, false)
+	e.flow(k, loc)
+	return loc.asHole()
+}
+
+// Fmt is called from node printing to print information about escape analysis results.
+func Fmt(n ir.Node) string {
+	text := ""
+	switch n.Esc() {
+	case ir.EscUnknown:
+		break
+
+	case ir.EscHeap:
+		text = "esc(h)"
+
+	case ir.EscNone:
+		text = "esc(no)"
+
+	case ir.EscNever:
+		text = "esc(N)"
+
+	default:
+		text = fmt.Sprintf("esc(%d)", n.Esc())
+	}
+
+	if n.Op() == ir.ONAME {
+		n := n.(*ir.Name)
+		if loc, ok := n.Opt.(*location); ok && loc.loopDepth != 0 {
+			if text != "" {
+				text += " "
+			}
+			text += fmt.Sprintf("ld(%d)", loc.loopDepth)
+		}
+	}
+
+	return text
+}
diff --git a/src/cmd/compile/internal/escape/leaks.go b/src/cmd/compile/internal/escape/leaks.go
new file mode 100644
index 00000000000..4c848a5ee78
--- /dev/null
+++ b/src/cmd/compile/internal/escape/leaks.go
@@ -0,0 +1,106 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"math"
+	"strings"
+)
+
+const numEscResults = 7
+
+// An leaks represents a set of assignment flows from a parameter
+// to the heap or to any of its function's (first numEscResults)
+// result parameters.
+type leaks [1 + numEscResults]uint8
+
+// Empty reports whether l is an empty set (i.e., no assignment flows).
+func (l leaks) Empty() bool { return l == leaks{} }
+
+// Heap returns the minimum deref count of any assignment flow from l
+// to the heap. If no such flows exist, Heap returns -1.
+func (l leaks) Heap() int { return l.get(0) }
+
+// Result returns the minimum deref count of any assignment flow from
+// l to its function's i'th result parameter. If no such flows exist,
+// Result returns -1.
+func (l leaks) Result(i int) int { return l.get(1 + i) }
+
+// AddHeap adds an assignment flow from l to the heap.
+func (l *leaks) AddHeap(derefs int) { l.add(0, derefs) }
+
+// AddResult adds an assignment flow from l to its function's i'th
+// result parameter.
+func (l *leaks) AddResult(i, derefs int) { l.add(1+i, derefs) }
+
+func (l *leaks) setResult(i, derefs int) { l.set(1+i, derefs) }
+
+func (l leaks) get(i int) int { return int(l[i]) - 1 }
+
+func (l *leaks) add(i, derefs int) {
+	if old := l.get(i); old < 0 || derefs < old {
+		l.set(i, derefs)
+	}
+}
+
+func (l *leaks) set(i, derefs int) {
+	v := derefs + 1
+	if v < 0 {
+		base.Fatalf("invalid derefs count: %v", derefs)
+	}
+	if v > math.MaxUint8 {
+		v = math.MaxUint8
+	}
+
+	l[i] = uint8(v)
+}
+
+// Optimize removes result flow paths that are equal in length or
+// longer than the shortest heap flow path.
+func (l *leaks) Optimize() {
+	// If we have a path to the heap, then there's no use in
+	// keeping equal or longer paths elsewhere.
+	if x := l.Heap(); x >= 0 {
+		for i := 0; i < numEscResults; i++ {
+			if l.Result(i) >= x {
+				l.setResult(i, -1)
+			}
+		}
+	}
+}
+
+var leakTagCache = map[leaks]string{}
+
+// Encode converts l into a binary string for export data.
+func (l leaks) Encode() string {
+	if l.Heap() == 0 {
+		// Space optimization: empty string encodes more
+		// efficiently in export data.
+		return ""
+	}
+	if s, ok := leakTagCache[l]; ok {
+		return s
+	}
+
+	n := len(l)
+	for n > 0 && l[n-1] == 0 {
+		n--
+	}
+	s := "esc:" + string(l[:n])
+	leakTagCache[l] = s
+	return s
+}
+
+// parseLeaks parses a binary string representing a leaks
+func parseLeaks(s string) leaks {
+	var l leaks
+	if !strings.HasPrefix(s, "esc:") {
+		l.AddHeap(0)
+		return l
+	}
+	copy(l[:], s[4:])
+	return l
+}
diff --git a/src/cmd/compile/internal/escape/solve.go b/src/cmd/compile/internal/escape/solve.go
new file mode 100644
index 00000000000..77d6b27dd75
--- /dev/null
+++ b/src/cmd/compile/internal/escape/solve.go
@@ -0,0 +1,289 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/logopt"
+	"cmd/internal/src"
+	"fmt"
+	"strings"
+)
+
+// walkAll computes the minimal dereferences between all pairs of
+// locations.
+func (b *batch) walkAll() {
+	// We use a work queue to keep track of locations that we need
+	// to visit, and repeatedly walk until we reach a fixed point.
+	//
+	// We walk once from each location (including the heap), and
+	// then re-enqueue each location on its transition from
+	// transient->!transient and !escapes->escapes, which can each
+	// happen at most once. So we take Θ(len(e.allLocs)) walks.
+
+	// LIFO queue, has enough room for e.allLocs and e.heapLoc.
+	todo := make([]*location, 0, len(b.allLocs)+1)
+	enqueue := func(loc *location) {
+		if !loc.queued {
+			todo = append(todo, loc)
+			loc.queued = true
+		}
+	}
+
+	for _, loc := range b.allLocs {
+		enqueue(loc)
+	}
+	enqueue(&b.heapLoc)
+
+	var walkgen uint32
+	for len(todo) > 0 {
+		root := todo[len(todo)-1]
+		todo = todo[:len(todo)-1]
+		root.queued = false
+
+		walkgen++
+		b.walkOne(root, walkgen, enqueue)
+	}
+}
+
+// walkOne computes the minimal number of dereferences from root to
+// all other locations.
+func (b *batch) walkOne(root *location, walkgen uint32, enqueue func(*location)) {
+	// The data flow graph has negative edges (from addressing
+	// operations), so we use the Bellman-Ford algorithm. However,
+	// we don't have to worry about infinite negative cycles since
+	// we bound intermediate dereference counts to 0.
+
+	root.walkgen = walkgen
+	root.derefs = 0
+	root.dst = nil
+
+	todo := []*location{root} // LIFO queue
+	for len(todo) > 0 {
+		l := todo[len(todo)-1]
+		todo = todo[:len(todo)-1]
+
+		derefs := l.derefs
+
+		// If l.derefs < 0, then l's address flows to root.
+		addressOf := derefs < 0
+		if addressOf {
+			// For a flow path like "root = &l; l = x",
+			// l's address flows to root, but x's does
+			// not. We recognize this by lower bounding
+			// derefs at 0.
+			derefs = 0
+
+			// If l's address flows to a non-transient
+			// location, then l can't be transiently
+			// allocated.
+			if !root.transient && l.transient {
+				l.transient = false
+				enqueue(l)
+			}
+		}
+
+		if b.outlives(root, l) {
+			// l's value flows to root. If l is a function
+			// parameter and root is the heap or a
+			// corresponding result parameter, then record
+			// that value flow for tagging the function
+			// later.
+			if l.isName(ir.PPARAM) {
+				if (logopt.Enabled() || base.Flag.LowerM >= 2) && !l.escapes {
+					if base.Flag.LowerM >= 2 {
+						fmt.Printf("%s: parameter %v leaks to %s with derefs=%d:\n", base.FmtPos(l.n.Pos()), l.n, b.explainLoc(root), derefs)
+					}
+					explanation := b.explainPath(root, l)
+					if logopt.Enabled() {
+						var e_curfn *ir.Func // TODO(mdempsky): Fix.
+						logopt.LogOpt(l.n.Pos(), "leak", "escape", ir.FuncName(e_curfn),
+							fmt.Sprintf("parameter %v leaks to %s with derefs=%d", l.n, b.explainLoc(root), derefs), explanation)
+					}
+				}
+				l.leakTo(root, derefs)
+			}
+
+			// If l's address flows somewhere that
+			// outlives it, then l needs to be heap
+			// allocated.
+			if addressOf && !l.escapes {
+				if logopt.Enabled() || base.Flag.LowerM >= 2 {
+					if base.Flag.LowerM >= 2 {
+						fmt.Printf("%s: %v escapes to heap:\n", base.FmtPos(l.n.Pos()), l.n)
+					}
+					explanation := b.explainPath(root, l)
+					if logopt.Enabled() {
+						var e_curfn *ir.Func // TODO(mdempsky): Fix.
+						logopt.LogOpt(l.n.Pos(), "escape", "escape", ir.FuncName(e_curfn), fmt.Sprintf("%v escapes to heap", l.n), explanation)
+					}
+				}
+				l.escapes = true
+				enqueue(l)
+				continue
+			}
+		}
+
+		for i, edge := range l.edges {
+			if edge.src.escapes {
+				continue
+			}
+			d := derefs + edge.derefs
+			if edge.src.walkgen != walkgen || edge.src.derefs > d {
+				edge.src.walkgen = walkgen
+				edge.src.derefs = d
+				edge.src.dst = l
+				edge.src.dstEdgeIdx = i
+				todo = append(todo, edge.src)
+			}
+		}
+	}
+}
+
+// explainPath prints an explanation of how src flows to the walk root.
+func (b *batch) explainPath(root, src *location) []*logopt.LoggedOpt {
+	visited := make(map[*location]bool)
+	pos := base.FmtPos(src.n.Pos())
+	var explanation []*logopt.LoggedOpt
+	for {
+		// Prevent infinite loop.
+		if visited[src] {
+			if base.Flag.LowerM >= 2 {
+				fmt.Printf("%s:   warning: truncated explanation due to assignment cycle; see golang.org/issue/35518\n", pos)
+			}
+			break
+		}
+		visited[src] = true
+		dst := src.dst
+		edge := &dst.edges[src.dstEdgeIdx]
+		if edge.src != src {
+			base.Fatalf("path inconsistency: %v != %v", edge.src, src)
+		}
+
+		explanation = b.explainFlow(pos, dst, src, edge.derefs, edge.notes, explanation)
+
+		if dst == root {
+			break
+		}
+		src = dst
+	}
+
+	return explanation
+}
+
+func (b *batch) explainFlow(pos string, dst, srcloc *location, derefs int, notes *note, explanation []*logopt.LoggedOpt) []*logopt.LoggedOpt {
+	ops := "&"
+	if derefs >= 0 {
+		ops = strings.Repeat("*", derefs)
+	}
+	print := base.Flag.LowerM >= 2
+
+	flow := fmt.Sprintf("   flow: %s = %s%v:", b.explainLoc(dst), ops, b.explainLoc(srcloc))
+	if print {
+		fmt.Printf("%s:%s\n", pos, flow)
+	}
+	if logopt.Enabled() {
+		var epos src.XPos
+		if notes != nil {
+			epos = notes.where.Pos()
+		} else if srcloc != nil && srcloc.n != nil {
+			epos = srcloc.n.Pos()
+		}
+		var e_curfn *ir.Func // TODO(mdempsky): Fix.
+		explanation = append(explanation, logopt.NewLoggedOpt(epos, "escflow", "escape", ir.FuncName(e_curfn), flow))
+	}
+
+	for note := notes; note != nil; note = note.next {
+		if print {
+			fmt.Printf("%s:     from %v (%v) at %s\n", pos, note.where, note.why, base.FmtPos(note.where.Pos()))
+		}
+		if logopt.Enabled() {
+			var e_curfn *ir.Func // TODO(mdempsky): Fix.
+			explanation = append(explanation, logopt.NewLoggedOpt(note.where.Pos(), "escflow", "escape", ir.FuncName(e_curfn),
+				fmt.Sprintf("     from %v (%v)", note.where, note.why)))
+		}
+	}
+	return explanation
+}
+
+func (b *batch) explainLoc(l *location) string {
+	if l == &b.heapLoc {
+		return "{heap}"
+	}
+	if l.n == nil {
+		// TODO(mdempsky): Omit entirely.
+		return "{temp}"
+	}
+	if l.n.Op() == ir.ONAME {
+		return fmt.Sprintf("%v", l.n)
+	}
+	return fmt.Sprintf("{storage for %v}", l.n)
+}
+
+// outlives reports whether values stored in l may survive beyond
+// other's lifetime if stack allocated.
+func (b *batch) outlives(l, other *location) bool {
+	// The heap outlives everything.
+	if l.escapes {
+		return true
+	}
+
+	// We don't know what callers do with returned values, so
+	// pessimistically we need to assume they flow to the heap and
+	// outlive everything too.
+	if l.isName(ir.PPARAMOUT) {
+		// Exception: Directly called closures can return
+		// locations allocated outside of them without forcing
+		// them to the heap. For example:
+		//
+		//    var u int  // okay to stack allocate
+		//    *(func() *int { return &u }()) = 42
+		if containsClosure(other.curfn, l.curfn) && l.curfn.ClosureCalled() {
+			return false
+		}
+
+		return true
+	}
+
+	// If l and other are within the same function, then l
+	// outlives other if it was declared outside other's loop
+	// scope. For example:
+	//
+	//    var l *int
+	//    for {
+	//        l = new(int)
+	//    }
+	if l.curfn == other.curfn && l.loopDepth < other.loopDepth {
+		return true
+	}
+
+	// If other is declared within a child closure of where l is
+	// declared, then l outlives it. For example:
+	//
+	//    var l *int
+	//    func() {
+	//        l = new(int)
+	//    }
+	if containsClosure(l.curfn, other.curfn) {
+		return true
+	}
+
+	return false
+}
+
+// containsClosure reports whether c is a closure contained within f.
+func containsClosure(f, c *ir.Func) bool {
+	// Common case.
+	if f == c {
+		return false
+	}
+
+	// Closures within function Foo are named like "Foo.funcN..."
+	// TODO(mdempsky): Better way to recognize this.
+	fn := f.Sym().Name
+	cn := c.Sym().Name
+	return len(cn) > len(fn) && cn[:len(fn)] == fn && cn[len(fn)] == '.'
+}
diff --git a/src/cmd/compile/internal/escape/stmt.go b/src/cmd/compile/internal/escape/stmt.go
new file mode 100644
index 00000000000..c71848b8a1c
--- /dev/null
+++ b/src/cmd/compile/internal/escape/stmt.go
@@ -0,0 +1,207 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"fmt"
+)
+
+// stmt evaluates a single Go statement.
+func (e *escape) stmt(n ir.Node) {
+	if n == nil {
+		return
+	}
+
+	lno := ir.SetPos(n)
+	defer func() {
+		base.Pos = lno
+	}()
+
+	if base.Flag.LowerM > 2 {
+		fmt.Printf("%v:[%d] %v stmt: %v\n", base.FmtPos(base.Pos), e.loopDepth, e.curfn, n)
+	}
+
+	e.stmts(n.Init())
+
+	switch n.Op() {
+	default:
+		base.Fatalf("unexpected stmt: %v", n)
+
+	case ir.ODCLCONST, ir.ODCLTYPE, ir.OFALL, ir.OINLMARK:
+		// nop
+
+	case ir.OBREAK, ir.OCONTINUE, ir.OGOTO:
+		// TODO(mdempsky): Handle dead code?
+
+	case ir.OBLOCK:
+		n := n.(*ir.BlockStmt)
+		e.stmts(n.List)
+
+	case ir.ODCL:
+		// Record loop depth at declaration.
+		n := n.(*ir.Decl)
+		if !ir.IsBlank(n.X) {
+			e.dcl(n.X)
+		}
+
+	case ir.OLABEL:
+		n := n.(*ir.LabelStmt)
+		switch e.labels[n.Label] {
+		case nonlooping:
+			if base.Flag.LowerM > 2 {
+				fmt.Printf("%v:%v non-looping label\n", base.FmtPos(base.Pos), n)
+			}
+		case looping:
+			if base.Flag.LowerM > 2 {
+				fmt.Printf("%v: %v looping label\n", base.FmtPos(base.Pos), n)
+			}
+			e.loopDepth++
+		default:
+			base.Fatalf("label missing tag")
+		}
+		delete(e.labels, n.Label)
+
+	case ir.OIF:
+		n := n.(*ir.IfStmt)
+		e.discard(n.Cond)
+		e.block(n.Body)
+		e.block(n.Else)
+
+	case ir.OFOR, ir.OFORUNTIL:
+		n := n.(*ir.ForStmt)
+		e.loopDepth++
+		e.discard(n.Cond)
+		e.stmt(n.Post)
+		e.block(n.Body)
+		e.loopDepth--
+
+	case ir.ORANGE:
+		// for Key, Value = range X { Body }
+		n := n.(*ir.RangeStmt)
+
+		// X is evaluated outside the loop.
+		tmp := e.newLoc(nil, false)
+		e.expr(tmp.asHole(), n.X)
+
+		e.loopDepth++
+		ks := e.addrs([]ir.Node{n.Key, n.Value})
+		if n.X.Type().IsArray() {
+			e.flow(ks[1].note(n, "range"), tmp)
+		} else {
+			e.flow(ks[1].deref(n, "range-deref"), tmp)
+		}
+		e.reassigned(ks, n)
+
+		e.block(n.Body)
+		e.loopDepth--
+
+	case ir.OSWITCH:
+		n := n.(*ir.SwitchStmt)
+
+		if guard, ok := n.Tag.(*ir.TypeSwitchGuard); ok {
+			var ks []hole
+			if guard.Tag != nil {
+				for _, cas := range n.Cases {
+					cv := cas.Var
+					k := e.dcl(cv) // type switch variables have no ODCL.
+					if cv.Type().HasPointers() {
+						ks = append(ks, k.dotType(cv.Type(), cas, "switch case"))
+					}
+				}
+			}
+			e.expr(e.teeHole(ks...), n.Tag.(*ir.TypeSwitchGuard).X)
+		} else {
+			e.discard(n.Tag)
+		}
+
+		for _, cas := range n.Cases {
+			e.discards(cas.List)
+			e.block(cas.Body)
+		}
+
+	case ir.OSELECT:
+		n := n.(*ir.SelectStmt)
+		for _, cas := range n.Cases {
+			e.stmt(cas.Comm)
+			e.block(cas.Body)
+		}
+	case ir.ORECV:
+		// TODO(mdempsky): Consider e.discard(n.Left).
+		n := n.(*ir.UnaryExpr)
+		e.exprSkipInit(e.discardHole(), n) // already visited n.Ninit
+	case ir.OSEND:
+		n := n.(*ir.SendStmt)
+		e.discard(n.Chan)
+		e.assignHeap(n.Value, "send", n)
+
+	case ir.OAS:
+		n := n.(*ir.AssignStmt)
+		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
+	case ir.OASOP:
+		n := n.(*ir.AssignOpStmt)
+		// TODO(mdempsky): Worry about OLSH/ORSH?
+		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
+	case ir.OAS2:
+		n := n.(*ir.AssignListStmt)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair", n)
+
+	case ir.OAS2DOTTYPE: // v, ok = x.(type)
+		n := n.(*ir.AssignListStmt)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-dot-type", n)
+	case ir.OAS2MAPR: // v, ok = m[k]
+		n := n.(*ir.AssignListStmt)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-mapr", n)
+	case ir.OAS2RECV, ir.OSELRECV2: // v, ok = <-ch
+		n := n.(*ir.AssignListStmt)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-receive", n)
+
+	case ir.OAS2FUNC:
+		n := n.(*ir.AssignListStmt)
+		e.stmts(n.Rhs[0].Init())
+		ks := e.addrs(n.Lhs)
+		e.call(ks, n.Rhs[0])
+		e.reassigned(ks, n)
+	case ir.ORETURN:
+		n := n.(*ir.ReturnStmt)
+		results := e.curfn.Type().Results().FieldSlice()
+		dsts := make([]ir.Node, len(results))
+		for i, res := range results {
+			dsts[i] = res.Nname.(*ir.Name)
+		}
+		e.assignList(dsts, n.Results, "return", n)
+	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OINLCALL, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
+		e.call(nil, n)
+	case ir.OGO, ir.ODEFER:
+		n := n.(*ir.GoDeferStmt)
+		e.goDeferStmt(n)
+
+	case ir.OTAILCALL:
+		// TODO(mdempsky): Treat like a normal call? esc.go used to just ignore it.
+	}
+}
+
+func (e *escape) stmts(l ir.Nodes) {
+	for _, n := range l {
+		e.stmt(n)
+	}
+}
+
+// block is like stmts, but preserves loopDepth.
+func (e *escape) block(l ir.Nodes) {
+	old := e.loopDepth
+	e.stmts(l)
+	e.loopDepth = old
+}
+
+func (e *escape) dcl(n *ir.Name) hole {
+	if n.Curfn != e.curfn || n.IsClosureVar() {
+		base.Fatalf("bad declaration of %v", n)
+	}
+	loc := e.oldLoc(n)
+	loc.loopDepth = e.loopDepth
+	return loc.asHole()
+}
diff --git a/src/cmd/compile/internal/escape/utils.go b/src/cmd/compile/internal/escape/utils.go
new file mode 100644
index 00000000000..5f462ef570f
--- /dev/null
+++ b/src/cmd/compile/internal/escape/utils.go
@@ -0,0 +1,215 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package escape
+
+import (
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/typecheck"
+)
+
+func isSliceSelfAssign(dst, src ir.Node) bool {
+	// Detect the following special case.
+	//
+	//	func (b *Buffer) Foo() {
+	//		n, m := ...
+	//		b.buf = b.buf[n:m]
+	//	}
+	//
+	// This assignment is a no-op for escape analysis,
+	// it does not store any new pointers into b that were not already there.
+	// However, without this special case b will escape, because we assign to OIND/ODOTPTR.
+	// Here we assume that the statement will not contain calls,
+	// that is, that order will move any calls to init.
+	// Otherwise base ONAME value could change between the moments
+	// when we evaluate it for dst and for src.
+
+	// dst is ONAME dereference.
+	var dstX ir.Node
+	switch dst.Op() {
+	default:
+		return false
+	case ir.ODEREF:
+		dst := dst.(*ir.StarExpr)
+		dstX = dst.X
+	case ir.ODOTPTR:
+		dst := dst.(*ir.SelectorExpr)
+		dstX = dst.X
+	}
+	if dstX.Op() != ir.ONAME {
+		return false
+	}
+	// src is a slice operation.
+	switch src.Op() {
+	case ir.OSLICE, ir.OSLICE3, ir.OSLICESTR:
+		// OK.
+	case ir.OSLICEARR, ir.OSLICE3ARR:
+		// Since arrays are embedded into containing object,
+		// slice of non-pointer array will introduce a new pointer into b that was not already there
+		// (pointer to b itself). After such assignment, if b contents escape,
+		// b escapes as well. If we ignore such OSLICEARR, we will conclude
+		// that b does not escape when b contents do.
+		//
+		// Pointer to an array is OK since it's not stored inside b directly.
+		// For slicing an array (not pointer to array), there is an implicit OADDR.
+		// We check that to determine non-pointer array slicing.
+		src := src.(*ir.SliceExpr)
+		if src.X.Op() == ir.OADDR {
+			return false
+		}
+	default:
+		return false
+	}
+	// slice is applied to ONAME dereference.
+	var baseX ir.Node
+	switch base := src.(*ir.SliceExpr).X; base.Op() {
+	default:
+		return false
+	case ir.ODEREF:
+		base := base.(*ir.StarExpr)
+		baseX = base.X
+	case ir.ODOTPTR:
+		base := base.(*ir.SelectorExpr)
+		baseX = base.X
+	}
+	if baseX.Op() != ir.ONAME {
+		return false
+	}
+	// dst and src reference the same base ONAME.
+	return dstX.(*ir.Name) == baseX.(*ir.Name)
+}
+
+// isSelfAssign reports whether assignment from src to dst can
+// be ignored by the escape analysis as it's effectively a self-assignment.
+func isSelfAssign(dst, src ir.Node) bool {
+	if isSliceSelfAssign(dst, src) {
+		return true
+	}
+
+	// Detect trivial assignments that assign back to the same object.
+	//
+	// It covers these cases:
+	//	val.x = val.y
+	//	val.x[i] = val.y[j]
+	//	val.x1.x2 = val.x1.y2
+	//	... etc
+	//
+	// These assignments do not change assigned object lifetime.
+
+	if dst == nil || src == nil || dst.Op() != src.Op() {
+		return false
+	}
+
+	// The expression prefix must be both "safe" and identical.
+	switch dst.Op() {
+	case ir.ODOT, ir.ODOTPTR:
+		// Safe trailing accessors that are permitted to differ.
+		dst := dst.(*ir.SelectorExpr)
+		src := src.(*ir.SelectorExpr)
+		return ir.SameSafeExpr(dst.X, src.X)
+	case ir.OINDEX:
+		dst := dst.(*ir.IndexExpr)
+		src := src.(*ir.IndexExpr)
+		if mayAffectMemory(dst.Index) || mayAffectMemory(src.Index) {
+			return false
+		}
+		return ir.SameSafeExpr(dst.X, src.X)
+	default:
+		return false
+	}
+}
+
+// mayAffectMemory reports whether evaluation of n may affect the program's
+// memory state. If the expression can't affect memory state, then it can be
+// safely ignored by the escape analysis.
+func mayAffectMemory(n ir.Node) bool {
+	// We may want to use a list of "memory safe" ops instead of generally
+	// "side-effect free", which would include all calls and other ops that can
+	// allocate or change global state. For now, it's safer to start with the latter.
+	//
+	// We're ignoring things like division by zero, index out of range,
+	// and nil pointer dereference here.
+
+	// TODO(rsc): It seems like it should be possible to replace this with
+	// an ir.Any looking for any op that's not the ones in the case statement.
+	// But that produces changes in the compiled output detected by buildall.
+	switch n.Op() {
+	case ir.ONAME, ir.OLITERAL, ir.ONIL:
+		return false
+
+	case ir.OADD, ir.OSUB, ir.OOR, ir.OXOR, ir.OMUL, ir.OLSH, ir.ORSH, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OMOD:
+		n := n.(*ir.BinaryExpr)
+		return mayAffectMemory(n.X) || mayAffectMemory(n.Y)
+
+	case ir.OINDEX:
+		n := n.(*ir.IndexExpr)
+		return mayAffectMemory(n.X) || mayAffectMemory(n.Index)
+
+	case ir.OCONVNOP, ir.OCONV:
+		n := n.(*ir.ConvExpr)
+		return mayAffectMemory(n.X)
+
+	case ir.OLEN, ir.OCAP, ir.ONOT, ir.OBITNOT, ir.OPLUS, ir.ONEG, ir.OALIGNOF, ir.OOFFSETOF, ir.OSIZEOF:
+		n := n.(*ir.UnaryExpr)
+		return mayAffectMemory(n.X)
+
+	case ir.ODOT, ir.ODOTPTR:
+		n := n.(*ir.SelectorExpr)
+		return mayAffectMemory(n.X)
+
+	case ir.ODEREF:
+		n := n.(*ir.StarExpr)
+		return mayAffectMemory(n.X)
+
+	default:
+		return true
+	}
+}
+
+// HeapAllocReason returns the reason the given Node must be heap
+// allocated, or the empty string if it doesn't.
+func HeapAllocReason(n ir.Node) string {
+	if n == nil || n.Type() == nil {
+		return ""
+	}
+
+	// Parameters are always passed via the stack.
+	if n.Op() == ir.ONAME {
+		n := n.(*ir.Name)
+		if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
+			return ""
+		}
+	}
+
+	if n.Type().Width > ir.MaxStackVarSize {
+		return "too large for stack"
+	}
+
+	if (n.Op() == ir.ONEW || n.Op() == ir.OPTRLIT) && n.Type().Elem().Width > ir.MaxImplicitStackVarSize {
+		return "too large for stack"
+	}
+
+	if n.Op() == ir.OCLOSURE && typecheck.ClosureType(n.(*ir.ClosureExpr)).Size() > ir.MaxImplicitStackVarSize {
+		return "too large for stack"
+	}
+	if n.Op() == ir.OMETHVALUE && typecheck.MethodValueType(n.(*ir.SelectorExpr)).Size() > ir.MaxImplicitStackVarSize {
+		return "too large for stack"
+	}
+
+	if n.Op() == ir.OMAKESLICE {
+		n := n.(*ir.MakeExpr)
+		r := n.Cap
+		if r == nil {
+			r = n.Len
+		}
+		if !ir.IsSmallIntConst(r) {
+			return "non-constant size"
+		}
+		if t := n.Type(); t.Elem().Width != 0 && ir.Int64Val(r) > ir.MaxImplicitStackVarSize/t.Elem().Width {
+			return "too large for stack"
+		}
+	}
+
+	return ""
+}
diff --git a/src/cmd/compile/internal/gc/compile.go b/src/cmd/compile/internal/gc/compile.go
index a7380510d12..00504451a88 100644
--- a/src/cmd/compile/internal/gc/compile.go
+++ b/src/cmd/compile/internal/gc/compile.go
@@ -119,38 +119,51 @@ func compileFunctions() {
 		})
 	}
 
-	// We queue up a goroutine per function that needs to be
-	// compiled, but require them to grab an available worker ID
-	// before doing any substantial work to limit parallelism.
-	workerIDs := make(chan int, base.Flag.LowerC)
-	for i := 0; i < base.Flag.LowerC; i++ {
-		workerIDs <- i
+	// By default, we perform work right away on the current goroutine
+	// as the solo worker.
+	queue := func(work func(int)) {
+		work(0)
+	}
+
+	if nWorkers := base.Flag.LowerC; nWorkers > 1 {
+		// For concurrent builds, we create a goroutine per task, but
+		// require them to hold a unique worker ID while performing work
+		// to limit parallelism.
+		workerIDs := make(chan int, nWorkers)
+		for i := 0; i < nWorkers; i++ {
+			workerIDs <- i
+		}
+
+		queue = func(work func(int)) {
+			go func() {
+				worker := <-workerIDs
+				work(worker)
+				workerIDs <- worker
+			}()
+		}
 	}
 
 	var wg sync.WaitGroup
-	var asyncCompile func(*ir.Func)
-	asyncCompile = func(fn *ir.Func) {
-		wg.Add(1)
-		go func() {
-			worker := <-workerIDs
-			ssagen.Compile(fn, worker)
-			workerIDs <- worker
-
-			// Done compiling fn. Schedule it's closures for compilation.
-			for _, closure := range fn.Closures {
-				asyncCompile(closure)
-			}
-			wg.Done()
-		}()
+	var compile func([]*ir.Func)
+	compile = func(fns []*ir.Func) {
+		wg.Add(len(fns))
+		for _, fn := range fns {
+			fn := fn
+			queue(func(worker int) {
+				ssagen.Compile(fn, worker)
+				compile(fn.Closures)
+				wg.Done()
+			})
+		}
 	}
 
 	types.CalcSizeDisabled = true // not safe to calculate sizes concurrently
 	base.Ctxt.InParallel = true
-	for _, fn := range compilequeue {
-		asyncCompile(fn)
-	}
+
+	compile(compilequeue)
 	compilequeue = nil
 	wg.Wait()
+
 	base.Ctxt.InParallel = false
 	types.CalcSizeDisabled = false
 }
diff --git a/src/cmd/compile/internal/gc/export.go b/src/cmd/compile/internal/gc/export.go
index 2137f1d1961..9bf3c7240ac 100644
--- a/src/cmd/compile/internal/gc/export.go
+++ b/src/cmd/compile/internal/gc/export.go
@@ -5,46 +5,16 @@
 package gc
 
 import (
+	"fmt"
+	"go/constant"
+
 	"cmd/compile/internal/base"
-	"cmd/compile/internal/inline"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/internal/bio"
-	"fmt"
-	"go/constant"
 )
 
-func exportf(bout *bio.Writer, format string, args ...interface{}) {
-	fmt.Fprintf(bout, format, args...)
-	if base.Debug.Export != 0 {
-		fmt.Printf(format, args...)
-	}
-}
-
-func dumpexport(bout *bio.Writer) {
-	p := &exporter{marked: make(map[*types.Type]bool)}
-	for _, n := range typecheck.Target.Exports {
-		// Must catch it here rather than Export(), because the type can be
-		// not fully set (still TFORW) when Export() is called.
-		if n.Type() != nil && n.Type().HasTParam() {
-			base.Fatalf("Cannot (yet) export a generic type: %v", n)
-		}
-		p.markObject(n)
-	}
-
-	// The linker also looks for the $$ marker - use char after $$ to distinguish format.
-	exportf(bout, "\n$$B\n") // indicate binary export format
-	off := bout.Offset()
-	typecheck.WriteExports(bout.Writer)
-	size := bout.Offset() - off
-	exportf(bout, "\n$$\n")
-
-	if base.Debug.Export != 0 {
-		fmt.Printf("BenchmarkExportSize:%s 1 %d bytes\n", base.Ctxt.Pkgpath, size)
-	}
-}
-
 func dumpasmhdr() {
 	b, err := bio.Create(base.Flag.AsmHdr)
 	if err != nil {
@@ -79,83 +49,3 @@ func dumpasmhdr() {
 
 	b.Close()
 }
-
-type exporter struct {
-	marked map[*types.Type]bool // types already seen by markType
-}
-
-// markObject visits a reachable object.
-func (p *exporter) markObject(n ir.Node) {
-	if n.Op() == ir.ONAME {
-		n := n.(*ir.Name)
-		if n.Class == ir.PFUNC {
-			inline.Inline_Flood(n, typecheck.Export)
-		}
-	}
-
-	p.markType(n.Type())
-}
-
-// markType recursively visits types reachable from t to identify
-// functions whose inline bodies may be needed.
-func (p *exporter) markType(t *types.Type) {
-	if p.marked[t] {
-		return
-	}
-	p.marked[t] = true
-
-	// If this is a named type, mark all of its associated
-	// methods. Skip interface types because t.Methods contains
-	// only their unexpanded method set (i.e., exclusive of
-	// interface embeddings), and the switch statement below
-	// handles their full method set.
-	if t.Sym() != nil && t.Kind() != types.TINTER {
-		for _, m := range t.Methods().Slice() {
-			if types.IsExported(m.Sym.Name) {
-				p.markObject(ir.AsNode(m.Nname))
-			}
-		}
-	}
-
-	// Recursively mark any types that can be produced given a
-	// value of type t: dereferencing a pointer; indexing or
-	// iterating over an array, slice, or map; receiving from a
-	// channel; accessing a struct field or interface method; or
-	// calling a function.
-	//
-	// Notably, we don't mark function parameter types, because
-	// the user already needs some way to construct values of
-	// those types.
-	switch t.Kind() {
-	case types.TPTR, types.TARRAY, types.TSLICE:
-		p.markType(t.Elem())
-
-	case types.TCHAN:
-		if t.ChanDir().CanRecv() {
-			p.markType(t.Elem())
-		}
-
-	case types.TMAP:
-		p.markType(t.Key())
-		p.markType(t.Elem())
-
-	case types.TSTRUCT:
-		for _, f := range t.FieldSlice() {
-			if types.IsExported(f.Sym.Name) || f.Embedded != 0 {
-				p.markType(f.Type)
-			}
-		}
-
-	case types.TFUNC:
-		for _, f := range t.Results().FieldSlice() {
-			p.markType(f.Type)
-		}
-
-	case types.TINTER:
-		for _, f := range t.AllMethods().Slice() {
-			if types.IsExported(f.Sym.Name) {
-				p.markType(f.Type)
-			}
-		}
-	}
-}
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index ce50cbb4c2e..6a373ce33d7 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -32,6 +32,7 @@ import (
 	"log"
 	"os"
 	"runtime"
+	"sort"
 )
 
 func hidePanic() {
@@ -159,9 +160,6 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 		dwarf.EnableLogging(base.Debug.DwarfInl != 0)
 	}
 	if base.Debug.SoftFloat != 0 {
-		if buildcfg.Experiment.RegabiArgs {
-			log.Fatalf("softfloat mode with GOEXPERIMENT=regabiargs not implemented ")
-		}
 		ssagen.Arch.SoftFloat = true
 	}
 
@@ -181,23 +179,41 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	typecheck.Target = new(ir.Package)
 
-	typecheck.NeedITab = func(t, iface *types.Type) { reflectdata.ITabAddr(t, iface) }
 	typecheck.NeedRuntimeType = reflectdata.NeedRuntimeType // TODO(rsc): TypeSym for lock?
 
 	base.AutogeneratedPos = makePos(src.NewFileBase("", ""), 1, 0)
 
 	typecheck.InitUniverse()
+	typecheck.InitRuntime()
 
 	// Parse and typecheck input.
 	noder.LoadPackage(flag.Args())
 
 	dwarfgen.RecordPackageName()
 
+	// Prepare for backend processing. This must happen before pkginit,
+	// because it generates itabs for initializing global variables.
+	ssagen.InitConfig()
+
 	// Build init task.
 	if initTask := pkginit.Task(); initTask != nil {
 		typecheck.Export(initTask)
 	}
 
+	// Stability quirk: sort top-level declarations, so we're not
+	// sensitive to the order that functions are added. In particular,
+	// the order that noder+typecheck add function closures is very
+	// subtle, and not important to reproduce.
+	//
+	// Note: This needs to happen after pkginit.Task, otherwise it risks
+	// changing the order in which top-level variables are initialized.
+	if base.Debug.UnifiedQuirks != 0 {
+		s := typecheck.Target.Decls
+		sort.SliceStable(s, func(i, j int) bool {
+			return s[i].Pos().Before(s[j].Pos())
+		})
+	}
+
 	// Eliminate some obviously dead code.
 	// Must happen after typechecking.
 	for _, n := range typecheck.Target.Decls {
@@ -252,6 +268,11 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	base.Timer.Start("fe", "escapes")
 	escape.Funcs(typecheck.Target.Decls)
 
+	// TODO(mdempsky): This is a hack. We need a proper, global work
+	// queue for scheduling function compilation so components don't
+	// need to adjust their behavior depending on when they're called.
+	reflectdata.AfterGlobalEscapeAnalysis = true
+
 	// Collect information for go:nowritebarrierrec
 	// checking. This must happen before transforming closures during Walk
 	// We'll do the final check after write barriers are
@@ -260,17 +281,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 		ssagen.EnableNoWriteBarrierRecCheck()
 	}
 
-	// Prepare for SSA compilation.
-	// This must be before CompileITabs, because CompileITabs
-	// can trigger function compilation.
-	typecheck.InitRuntime()
-	ssagen.InitConfig()
-
-	// Just before compilation, compile itabs found on
-	// the right side of OCONVIFACE so that methods
-	// can be de-virtualized during compilation.
 	ir.CurFunc = nil
-	reflectdata.CompileITabs()
 
 	// Compile top level functions.
 	// Don't use range--walk can add functions to Target.Decls.
diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index 0b10cb8a9e1..c86bf5f0847 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -7,6 +7,7 @@ package gc
 import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
+	"cmd/compile/internal/noder"
 	"cmd/compile/internal/objw"
 	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/staticdata"
@@ -103,7 +104,7 @@ func finishArchiveEntry(bout *bio.Writer, start int64, name string) {
 
 func dumpCompilerObj(bout *bio.Writer) {
 	printObjHeader(bout)
-	dumpexport(bout)
+	noder.WriteExports(bout)
 }
 
 func dumpdata() {
@@ -116,7 +117,7 @@ func dumpdata() {
 	addsignats(typecheck.Target.Externs)
 	reflectdata.WriteRuntimeTypes()
 	reflectdata.WriteTabs()
-	numPTabs, numITabs := reflectdata.CountTabs()
+	numPTabs := reflectdata.CountPTabs()
 	reflectdata.WriteImportStrings()
 	reflectdata.WriteBasicTypes()
 	dumpembeds()
@@ -148,6 +149,7 @@ func dumpdata() {
 	if reflectdata.ZeroSize > 0 {
 		zero := base.PkgLinksym("go.map", "zero", obj.ABI0)
 		objw.Global(zero, int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
+		zero.Set(obj.AttrStatic, true)
 	}
 
 	staticdata.WriteFuncSyms()
@@ -156,13 +158,10 @@ func dumpdata() {
 	if numExports != len(typecheck.Target.Exports) {
 		base.Fatalf("Target.Exports changed after compile functions loop")
 	}
-	newNumPTabs, newNumITabs := reflectdata.CountTabs()
+	newNumPTabs := reflectdata.CountPTabs()
 	if newNumPTabs != numPTabs {
 		base.Fatalf("ptabs changed after compile functions loop")
 	}
-	if newNumITabs != numITabs {
-		base.Fatalf("itabs changed after compile functions loop")
-	}
 }
 
 func dumpLinkerObj(bout *bio.Writer) {
diff --git a/src/cmd/compile/internal/importer/exportdata.go b/src/cmd/compile/internal/importer/exportdata.go
index 3925a64314e..6a672be9c1b 100644
--- a/src/cmd/compile/internal/importer/exportdata.go
+++ b/src/cmd/compile/internal/importer/exportdata.go
@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/compile/internal/importer/gcimporter.go b/src/cmd/compile/internal/importer/gcimporter.go
index feb18cf2c9a..ff40be65bbe 100644
--- a/src/cmd/compile/internal/importer/gcimporter.go
+++ b/src/cmd/compile/internal/importer/gcimporter.go
@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
@@ -156,7 +155,7 @@ func Import(packages map[string]*types2.Package, path, srcDir string, lookup fun
 		// binary export format starts with a 'c', 'd', or 'v'
 		// (from "version"). Select appropriate importer.
 		if len(data) > 0 && data[0] == 'i' {
-			_, pkg, err = iImportData(packages, data[1:], id)
+			pkg, err = ImportData(packages, string(data[1:]), id)
 		} else {
 			err = fmt.Errorf("import %q: old binary export format no longer supported (recompile library)", path)
 		}
diff --git a/src/cmd/compile/internal/importer/gcimporter_test.go b/src/cmd/compile/internal/importer/gcimporter_test.go
index 7fb8fed59cf..44c5e06cd67 100644
--- a/src/cmd/compile/internal/importer/gcimporter_test.go
+++ b/src/cmd/compile/internal/importer/gcimporter_test.go
@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
@@ -10,7 +9,6 @@ import (
 	"cmd/compile/internal/types2"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -64,7 +62,7 @@ const maxTime = 30 * time.Second
 
 func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
 	dirname := filepath.Join(runtime.GOROOT(), "pkg", runtime.GOOS+"_"+runtime.GOARCH, dir)
-	list, err := ioutil.ReadDir(dirname)
+	list, err := os.ReadDir(dirname)
 	if err != nil {
 		t.Fatalf("testDir(%s): %s", dirname, err)
 	}
@@ -92,7 +90,7 @@ func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
 }
 
 func mktmpdir(t *testing.T) string {
-	tmpdir, err := ioutil.TempDir("", "gcimporter_test")
+	tmpdir, err := os.MkdirTemp("", "gcimporter_test")
 	if err != nil {
 		t.Fatal("mktmpdir:", err)
 	}
@@ -142,7 +140,7 @@ func TestVersionHandling(t *testing.T) {
 	}
 
 	const dir = "./testdata/versions"
-	list, err := ioutil.ReadDir(dir)
+	list, err := os.ReadDir(dir)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -195,7 +193,7 @@ func TestVersionHandling(t *testing.T) {
 
 		// create file with corrupted export data
 		// 1) read file
-		data, err := ioutil.ReadFile(filepath.Join(dir, name))
+		data, err := os.ReadFile(filepath.Join(dir, name))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -212,7 +210,7 @@ func TestVersionHandling(t *testing.T) {
 		// 4) write the file
 		pkgpath += "_corrupted"
 		filename := filepath.Join(corruptdir, pkgpath) + ".a"
-		ioutil.WriteFile(filename, data, 0666)
+		os.WriteFile(filename, data, 0666)
 
 		// test that importing the corrupted file results in an error
 		_, err = Import(make(map[string]*types2.Package), pkgpath, corruptdir, nil)
@@ -261,8 +259,7 @@ var importedObjectTests = []struct {
 	{"io.Reader", "type Reader interface{Read(p []byte) (n int, err error)}"},
 	{"io.ReadWriter", "type ReadWriter interface{Reader; Writer}"},
 	{"go/ast.Node", "type Node interface{End() go/token.Pos; Pos() go/token.Pos}"},
-	// go/types.Type has grown much larger - excluded for now
-	// {"go/types.Type", "type Type interface{String() string; Underlying() Type}"},
+	{"go/types.Type", "type Type interface{String() string; Underlying() Type}"},
 }
 
 func TestImportedTypes(t *testing.T) {
@@ -457,17 +454,17 @@ func TestIssue13898(t *testing.T) {
 		t.Fatal("go/types not found")
 	}
 
-	// look for go/types2.Object type
+	// look for go/types.Object type
 	obj := lookupObj(t, goTypesPkg.Scope(), "Object")
 	typ, ok := obj.Type().(*types2.Named)
 	if !ok {
-		t.Fatalf("go/types2.Object type is %v; wanted named type", typ)
+		t.Fatalf("go/types.Object type is %v; wanted named type", typ)
 	}
 
-	// lookup go/types2.Object.Pkg method
+	// lookup go/types.Object.Pkg method
 	m, index, indirect := types2.LookupFieldOrMethod(typ, false, nil, "Pkg")
 	if m == nil {
-		t.Fatalf("go/types2.Object.Pkg not found (index = %v, indirect = %v)", index, indirect)
+		t.Fatalf("go/types.Object.Pkg not found (index = %v, indirect = %v)", index, indirect)
 	}
 
 	// the method must belong to go/types
diff --git a/src/cmd/compile/internal/importer/iimport.go b/src/cmd/compile/internal/importer/iimport.go
index 8ab0b7b9896..a317dfc34ad 100644
--- a/src/cmd/compile/internal/importer/iimport.go
+++ b/src/cmd/compile/internal/importer/iimport.go
@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
@@ -9,7 +8,6 @@
 package importer
 
 import (
-	"bytes"
 	"cmd/compile/internal/syntax"
 	"cmd/compile/internal/types2"
 	"encoding/binary"
@@ -19,10 +17,11 @@ import (
 	"io"
 	"math/big"
 	"sort"
+	"strings"
 )
 
 type intReader struct {
-	*bytes.Reader
+	*strings.Reader
 	path string
 }
 
@@ -42,6 +41,21 @@ func (r *intReader) uint64() uint64 {
 	return i
 }
 
+// Keep this in sync with constants in iexport.go.
+const (
+	iexportVersionGo1_11 = 0
+	iexportVersionPosCol = 1
+	// TODO: before release, change this back to 2.
+	iexportVersionGenerics = iexportVersionPosCol
+
+	iexportVersionCurrent = iexportVersionGenerics
+)
+
+type ident struct {
+	pkg  string
+	name string
+}
+
 const predeclReserved = 32
 
 type itag uint64
@@ -57,6 +71,9 @@ const (
 	signatureType
 	structType
 	interfaceType
+	typeParamType
+	instType
+	unionType
 )
 
 const io_SeekCurrent = 1 // io.SeekCurrent (not defined in Go 1.4)
@@ -65,8 +82,8 @@ const io_SeekCurrent = 1 // io.SeekCurrent (not defined in Go 1.4)
 // and returns the number of bytes consumed and a reference to the package.
 // If the export data version is not recognized or the format is otherwise
 // compromised, an error is returned.
-func iImportData(imports map[string]*types2.Package, data []byte, path string) (_ int, pkg *types2.Package, err error) {
-	const currentVersion = 1
+func ImportData(imports map[string]*types2.Package, data, path string) (pkg *types2.Package, err error) {
+	const currentVersion = iexportVersionCurrent
 	version := int64(-1)
 	defer func() {
 		if e := recover(); e != nil {
@@ -78,13 +95,17 @@ func iImportData(imports map[string]*types2.Package, data []byte, path string) (
 		}
 	}()
 
-	r := &intReader{bytes.NewReader(data), path}
+	r := &intReader{strings.NewReader(data), path}
 
 	version = int64(r.uint64())
 	switch version {
-	case currentVersion, 0:
+	case /* iexportVersionGenerics, */ iexportVersionPosCol, iexportVersionGo1_11:
 	default:
-		errorf("unknown iexport format version %d", version)
+		if version > iexportVersionGenerics {
+			errorf("unstable iexport format version %d, just rebuild compiler and std library", version)
+		} else {
+			errorf("unknown iexport format version %d", version)
+		}
 	}
 
 	sLen := int64(r.uint64())
@@ -96,16 +117,20 @@ func iImportData(imports map[string]*types2.Package, data []byte, path string) (
 	r.Seek(sLen+dLen, io_SeekCurrent)
 
 	p := iimporter{
-		ipath:   path,
-		version: int(version),
+		exportVersion: version,
+		ipath:         path,
+		version:       int(version),
 
-		stringData:  stringData,
-		stringCache: make(map[uint64]string),
-		pkgCache:    make(map[uint64]*types2.Package),
+		stringData:   stringData,
+		pkgCache:     make(map[uint64]*types2.Package),
+		posBaseCache: make(map[uint64]*syntax.PosBase),
 
 		declData: declData,
 		pkgIndex: make(map[*types2.Package]map[string]uint64),
 		typCache: make(map[uint64]types2.Type),
+		// Separate map for typeparams, keyed by their package and unique
+		// name (name with subscript).
+		tparamIndex: make(map[ident]types2.Type),
 	}
 
 	for i, pt := range predeclared {
@@ -117,17 +142,22 @@ func iImportData(imports map[string]*types2.Package, data []byte, path string) (
 		pkgPathOff := r.uint64()
 		pkgPath := p.stringAt(pkgPathOff)
 		pkgName := p.stringAt(r.uint64())
-		_ = r.uint64() // package height; unused by go/types
+		pkgHeight := int(r.uint64())
 
 		if pkgPath == "" {
 			pkgPath = path
 		}
 		pkg := imports[pkgPath]
 		if pkg == nil {
-			pkg = types2.NewPackage(pkgPath, pkgName)
+			pkg = types2.NewPackageHeight(pkgPath, pkgName, pkgHeight)
 			imports[pkgPath] = pkg
-		} else if pkg.Name() != pkgName {
-			errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
+		} else {
+			if pkg.Name() != pkgName {
+				errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
+			}
+			if pkg.Height() != pkgHeight {
+				errorf("conflicting heights %v and %v for package %q", pkg.Height(), pkgHeight, path)
+			}
 		}
 
 		p.pkgCache[pkgPathOff] = pkg
@@ -153,10 +183,6 @@ func iImportData(imports map[string]*types2.Package, data []byte, path string) (
 		p.doDecl(localpkg, name)
 	}
 
-	for _, typ := range p.interfaceList {
-		typ.Complete()
-	}
-
 	// record all referenced packages as imports
 	list := append(([]*types2.Package)(nil), pkgList[1:]...)
 	sort.Sort(byPath(list))
@@ -165,21 +191,22 @@ func iImportData(imports map[string]*types2.Package, data []byte, path string) (
 	// package was imported completely and without errors
 	localpkg.MarkComplete()
 
-	consumed, _ := r.Seek(0, io_SeekCurrent)
-	return int(consumed), localpkg, nil
+	return localpkg, nil
 }
 
 type iimporter struct {
-	ipath   string
-	version int
+	exportVersion int64
+	ipath         string
+	version       int
 
-	stringData  []byte
-	stringCache map[uint64]string
-	pkgCache    map[uint64]*types2.Package
+	stringData   string
+	pkgCache     map[uint64]*types2.Package
+	posBaseCache map[uint64]*syntax.PosBase
 
-	declData []byte
-	pkgIndex map[*types2.Package]map[string]uint64
-	typCache map[uint64]types2.Type
+	declData    string
+	pkgIndex    map[*types2.Package]map[string]uint64
+	typCache    map[uint64]types2.Type
+	tparamIndex map[ident]types2.Type
 
 	interfaceList []*types2.Interface
 }
@@ -199,24 +226,21 @@ func (p *iimporter) doDecl(pkg *types2.Package, name string) {
 	// Reader.Reset is not available in Go 1.4.
 	// Use bytes.NewReader for now.
 	// r.declReader.Reset(p.declData[off:])
-	r.declReader = *bytes.NewReader(p.declData[off:])
+	r.declReader = *strings.NewReader(p.declData[off:])
 
 	r.obj(name)
 }
 
 func (p *iimporter) stringAt(off uint64) string {
-	if s, ok := p.stringCache[off]; ok {
-		return s
-	}
+	var x [binary.MaxVarintLen64]byte
+	n := copy(x[:], p.stringData[off:])
 
-	slen, n := binary.Uvarint(p.stringData[off:])
+	slen, n := binary.Uvarint(x[:n])
 	if n <= 0 {
 		errorf("varint failed")
 	}
 	spos := off + uint64(n)
-	s := string(p.stringData[spos : spos+slen])
-	p.stringCache[off] = s
-	return s
+	return p.stringData[spos : spos+slen]
 }
 
 func (p *iimporter) pkgAt(off uint64) *types2.Package {
@@ -228,6 +252,16 @@ func (p *iimporter) pkgAt(off uint64) *types2.Package {
 	return nil
 }
 
+func (p *iimporter) posBaseAt(off uint64) *syntax.PosBase {
+	if posBase, ok := p.posBaseCache[off]; ok {
+		return posBase
+	}
+	filename := p.stringAt(off)
+	posBase := syntax.NewFileBase(filename)
+	p.posBaseCache[off] = posBase
+	return posBase
+}
+
 func (p *iimporter) typAt(off uint64, base *types2.Named) types2.Type {
 	if t, ok := p.typCache[off]; ok && (base == nil || !isInterface(t)) {
 		return t
@@ -241,7 +275,7 @@ func (p *iimporter) typAt(off uint64, base *types2.Named) types2.Type {
 	// Reader.Reset is not available in Go 1.4.
 	// Use bytes.NewReader for now.
 	// r.declReader.Reset(p.declData[off-predeclReserved:])
-	r.declReader = *bytes.NewReader(p.declData[off-predeclReserved:])
+	r.declReader = *strings.NewReader(p.declData[off-predeclReserved:])
 	t := r.doType(base)
 
 	if base == nil || !isInterface(t) {
@@ -251,12 +285,12 @@ func (p *iimporter) typAt(off uint64, base *types2.Named) types2.Type {
 }
 
 type importReader struct {
-	p          *iimporter
-	declReader bytes.Reader
-	currPkg    *types2.Package
-	prevFile   string
-	prevLine   int64
-	prevColumn int64
+	p           *iimporter
+	declReader  strings.Reader
+	currPkg     *types2.Package
+	prevPosBase *syntax.PosBase
+	prevLine    int64
+	prevColumn  int64
 }
 
 func (r *importReader) obj(name string) {
@@ -274,16 +308,28 @@ func (r *importReader) obj(name string) {
 
 		r.declare(types2.NewConst(pos, r.currPkg, name, typ, val))
 
-	case 'F':
+	case 'F', 'G':
+		var tparams []*types2.TypeName
+		if tag == 'G' {
+			tparams = r.tparamList()
+		}
 		sig := r.signature(nil)
-
+		sig.SetTParams(tparams)
 		r.declare(types2.NewFunc(pos, r.currPkg, name, sig))
 
-	case 'T':
+	case 'T', 'U':
+		var tparams []*types2.TypeName
+		if tag == 'U' {
+			tparams = r.tparamList()
+		}
+
 		// Types can be recursive. We need to setup a stub
 		// declaration before recursing.
 		obj := types2.NewTypeName(pos, r.currPkg, name, nil)
 		named := types2.NewNamed(obj, nil, nil)
+		if tag == 'U' {
+			named.SetTParams(tparams)
+		}
 		r.declare(obj)
 
 		underlying := r.p.typAt(r.uint64(), named).Underlying()
@@ -296,10 +342,43 @@ func (r *importReader) obj(name string) {
 				recv := r.param()
 				msig := r.signature(recv)
 
+				// If the receiver has any targs, set those as the
+				// rparams of the method (since those are the
+				// typeparams being used in the method sig/body).
+				targs := baseType(msig.Recv().Type()).TArgs()
+				if len(targs) > 0 {
+					rparams := make([]*types2.TypeName, len(targs))
+					for i, targ := range targs {
+						rparams[i] = types2.AsTypeParam(targ).Obj()
+					}
+					msig.SetRParams(rparams)
+				}
+
 				named.AddMethod(types2.NewFunc(mpos, r.currPkg, mname, msig))
 			}
 		}
 
+	case 'P':
+		// We need to "declare" a typeparam in order to have a name that
+		// can be referenced recursively (if needed) in the type param's
+		// bound.
+		if r.p.exportVersion < iexportVersionGenerics {
+			errorf("unexpected type param type")
+		}
+		name0, sub := parseSubscript(name)
+		tn := types2.NewTypeName(pos, r.currPkg, name0, nil)
+		t := (*types2.Checker)(nil).NewTypeParam(tn, nil)
+		if sub == 0 {
+			errorf("missing subscript")
+		}
+		t.SetId(sub)
+		// To handle recursive references to the typeparam within its
+		// bound, save the partial type in tparamIndex before reading the bounds.
+		id := ident{r.currPkg.Name(), name}
+		r.p.tparamIndex[id] = t
+
+		t.SetConstraint(r.typ())
+
 	case 'V':
 		typ := r.typ()
 
@@ -439,12 +518,11 @@ func (r *importReader) pos() syntax.Pos {
 		r.posv0()
 	}
 
-	if r.prevFile == "" && r.prevLine == 0 && r.prevColumn == 0 {
+	if (r.prevPosBase == nil || r.prevPosBase.Filename() == "") && r.prevLine == 0 && r.prevColumn == 0 {
 		return syntax.Pos{}
 	}
-	// TODO(gri) fix this
-	// return r.p.fake.pos(r.prevFile, int(r.prevLine), int(r.prevColumn))
-	return syntax.Pos{}
+
+	return syntax.MakePos(r.prevPosBase, uint(r.prevLine), uint(r.prevColumn))
 }
 
 func (r *importReader) posv0() {
@@ -454,7 +532,7 @@ func (r *importReader) posv0() {
 	} else if l := r.int64(); l == -1 {
 		r.prevLine += deltaNewFile
 	} else {
-		r.prevFile = r.string()
+		r.prevPosBase = r.posBase()
 		r.prevLine = l
 	}
 }
@@ -466,7 +544,7 @@ func (r *importReader) posv1() {
 		delta = r.int64()
 		r.prevLine += delta >> 1
 		if delta&1 != 0 {
-			r.prevFile = r.string()
+			r.prevPosBase = r.posBase()
 		}
 	}
 }
@@ -480,8 +558,9 @@ func isInterface(t types2.Type) bool {
 	return ok
 }
 
-func (r *importReader) pkg() *types2.Package { return r.p.pkgAt(r.uint64()) }
-func (r *importReader) string() string       { return r.p.stringAt(r.uint64()) }
+func (r *importReader) pkg() *types2.Package     { return r.p.pkgAt(r.uint64()) }
+func (r *importReader) string() string           { return r.p.stringAt(r.uint64()) }
+func (r *importReader) posBase() *syntax.PosBase { return r.p.posBaseAt(r.uint64()) }
 
 func (r *importReader) doType(base *types2.Named) types2.Type {
 	switch k := r.kind(); k {
@@ -554,6 +633,47 @@ func (r *importReader) doType(base *types2.Named) types2.Type {
 		typ := types2.NewInterfaceType(methods, embeddeds)
 		r.p.interfaceList = append(r.p.interfaceList, typ)
 		return typ
+
+	case typeParamType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			errorf("unexpected type param type")
+		}
+		pkg, name := r.qualifiedIdent()
+		id := ident{pkg.Name(), name}
+		if t, ok := r.p.tparamIndex[id]; ok {
+			// We're already in the process of importing this typeparam.
+			return t
+		}
+		// Otherwise, import the definition of the typeparam now.
+		r.p.doDecl(pkg, name)
+		return r.p.tparamIndex[id]
+
+	case instType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			errorf("unexpected instantiation type")
+		}
+		pos := r.pos()
+		len := r.uint64()
+		targs := make([]types2.Type, len)
+		for i := range targs {
+			targs[i] = r.typ()
+		}
+		baseType := r.typ()
+		// The imported instantiated type doesn't include any methods, so
+		// we must always use the methods of the base (orig) type.
+		var check *types2.Checker // TODO provide a non-nil *Checker
+		t := check.Instantiate(pos, baseType, targs, nil, false)
+		return t
+
+	case unionType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			errorf("unexpected instantiation type")
+		}
+		terms := make([]*types2.Term, r.uint64())
+		for i := range terms {
+			terms[i] = types2.NewTerm(r.bool(), r.typ())
+		}
+		return types2.NewUnion(terms)
 	}
 }
 
@@ -568,6 +688,19 @@ func (r *importReader) signature(recv *types2.Var) *types2.Signature {
 	return types2.NewSignature(recv, params, results, variadic)
 }
 
+func (r *importReader) tparamList() []*types2.TypeName {
+	n := r.uint64()
+	if n == 0 {
+		return nil
+	}
+	xs := make([]*types2.TypeName, n)
+	for i := range xs {
+		typ := r.typ()
+		xs[i] = types2.AsTypeParam(typ).Obj()
+	}
+	return xs
+}
+
 func (r *importReader) paramList() *types2.Tuple {
 	xs := make([]*types2.Var, r.uint64())
 	for i := range xs {
@@ -610,3 +743,33 @@ func (r *importReader) byte() byte {
 	}
 	return x
 }
+
+func baseType(typ types2.Type) *types2.Named {
+	// pointer receivers are never types2.Named types
+	if p, _ := typ.(*types2.Pointer); p != nil {
+		typ = p.Elem()
+	}
+	// receiver base types are always (possibly generic) types2.Named types
+	n, _ := typ.(*types2.Named)
+	return n
+}
+
+func parseSubscript(name string) (string, uint64) {
+	// Extract the subscript value from the type param name. We export
+	// and import the subscript value, so that all type params have
+	// unique names.
+	sub := uint64(0)
+	startsub := -1
+	for i, r := range name {
+		if '₀' <= r && r < '₀'+10 {
+			if startsub == -1 {
+				startsub = i
+			}
+			sub = sub*10 + uint64(r-'₀')
+		}
+	}
+	if startsub >= 0 {
+		name = name[:startsub]
+	}
+	return name, sub
+}
diff --git a/src/cmd/compile/internal/importer/support.go b/src/cmd/compile/internal/importer/support.go
index 40b9c7c9583..6ceb413601f 100644
--- a/src/cmd/compile/internal/importer/support.go
+++ b/src/cmd/compile/internal/importer/support.go
@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
@@ -120,6 +119,9 @@ var predeclared = []types2.Type{
 
 	// used internally by gc; never used by this package or in .a files
 	anyType{},
+
+	// comparable
+	types2.Universe.Lookup("comparable").Type(),
 }
 
 type anyType struct{}
diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index a6829e9835f..45a533fcafc 100644
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -179,6 +179,8 @@ func CanInline(fn *ir.Func) {
 		Cost: inlineMaxBudget - visitor.budget,
 		Dcl:  pruneUnusedAutos(n.Defn.(*ir.Func).Dcl, &visitor),
 		Body: inlcopylist(fn.Body),
+
+		CanDelayResults: canDelayResults(fn),
 	}
 
 	if base.Flag.LowerM > 1 {
@@ -191,60 +193,36 @@ func CanInline(fn *ir.Func) {
 	}
 }
 
-// Inline_Flood marks n's inline body for export and recursively ensures
-// all called functions are marked too.
-func Inline_Flood(n *ir.Name, exportsym func(*ir.Name)) {
-	if n == nil {
-		return
-	}
-	if n.Op() != ir.ONAME || n.Class != ir.PFUNC {
-		base.Fatalf("Inline_Flood: unexpected %v, %v, %v", n, n.Op(), n.Class)
-	}
-	fn := n.Func
-	if fn == nil {
-		base.Fatalf("Inline_Flood: missing Func on %v", n)
-	}
-	if fn.Inl == nil {
-		return
-	}
+// canDelayResults reports whether inlined calls to fn can delay
+// declaring the result parameter until the "return" statement.
+func canDelayResults(fn *ir.Func) bool {
+	// We can delay declaring+initializing result parameters if:
+	// (1) there's exactly one "return" statement in the inlined function;
+	// (2) it's not an empty return statement (#44355); and
+	// (3) the result parameters aren't named.
 
-	if fn.ExportInline() {
-		return
-	}
-	fn.SetExportInline(true)
-
-	typecheck.ImportedBody(fn)
-
-	var doFlood func(n ir.Node)
-	doFlood = func(n ir.Node) {
-		switch n.Op() {
-		case ir.OMETHEXPR, ir.ODOTMETH:
-			Inline_Flood(ir.MethodExprName(n), exportsym)
-
-		case ir.ONAME:
-			n := n.(*ir.Name)
-			switch n.Class {
-			case ir.PFUNC:
-				Inline_Flood(n, exportsym)
-				exportsym(n)
-			case ir.PEXTERN:
-				exportsym(n)
+	nreturns := 0
+	ir.VisitList(fn.Body, func(n ir.Node) {
+		if n, ok := n.(*ir.ReturnStmt); ok {
+			nreturns++
+			if len(n.Results) == 0 {
+				nreturns++ // empty return statement (case 2)
 			}
+		}
+	})
 
-		case ir.OCALLPART:
-			// Okay, because we don't yet inline indirect
-			// calls to method values.
-		case ir.OCLOSURE:
-			// VisitList doesn't visit closure bodies, so force a
-			// recursive call to VisitList on the body of the closure.
-			ir.VisitList(n.(*ir.ClosureExpr).Func.Body, doFlood)
+	if nreturns != 1 {
+		return false // not exactly one return statement (case 1)
+	}
+
+	// temporaries for return values.
+	for _, param := range fn.Type().Results().FieldSlice() {
+		if sym := types.OrigSym(param.Sym); sym != nil && !sym.IsBlank() {
+			return false // found a named result parameter (case 3)
 		}
 	}
 
-	// Recursively identify all referenced functions for
-	// reexport. We want to include even non-called functions,
-	// because after inlining they might be callable.
-	ir.VisitList(ir.Nodes(fn.Inl.Body), doFlood)
+	return true
 }
 
 // hairyVisitor visits a function body to determine its inlining
@@ -295,6 +273,19 @@ func (v *hairyVisitor) doNode(n ir.Node) bool {
 				}
 			}
 		}
+		if n.X.Op() == ir.OMETHEXPR {
+			if meth := ir.MethodExprName(n.X); meth != nil {
+				fn := meth.Func
+				if fn != nil && types.IsRuntimePkg(fn.Sym().Pkg) && fn.Sym().Name == "heapBits.nextArena" {
+					// Special case: explicitly allow
+					// mid-stack inlining of
+					// runtime.heapBits.next even though
+					// it calls slow-path
+					// runtime.heapBits.nextArena.
+					break
+				}
+			}
+		}
 
 		if ir.IsIntrinsicCall(n) {
 			// Treat like any other node.
@@ -309,28 +300,8 @@ func (v *hairyVisitor) doNode(n ir.Node) bool {
 		// Call cost for non-leaf inlining.
 		v.budget -= v.extraCallCost
 
-	// Call is okay if inlinable and we have the budget for the body.
 	case ir.OCALLMETH:
-		n := n.(*ir.CallExpr)
-		t := n.X.Type()
-		if t == nil {
-			base.Fatalf("no function type for [%p] %+v\n", n.X, n.X)
-		}
-		fn := ir.MethodExprName(n.X).Func
-		if types.IsRuntimePkg(fn.Sym().Pkg) && fn.Sym().Name == "heapBits.nextArena" {
-			// Special case: explicitly allow
-			// mid-stack inlining of
-			// runtime.heapBits.next even though
-			// it calls slow-path
-			// runtime.heapBits.nextArena.
-			break
-		}
-		if fn.Inl != nil {
-			v.budget -= fn.Inl.Cost
-			break
-		}
-		// Call cost for non-leaf inlining.
-		v.budget -= v.extraCallCost
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
 
 	// Things that are too hairy, irrespective of the budget
 	case ir.OCALL, ir.OCALLINTER:
@@ -445,7 +416,7 @@ func (v *hairyVisitor) doNode(n ir.Node) bool {
 		// and don't charge for the OBLOCK itself. The ++ undoes the -- below.
 		v.budget++
 
-	case ir.OCALLPART, ir.OSLICELIT:
+	case ir.OMETHVALUE, ir.OSLICELIT:
 		v.budget-- // Hack for toolstash -cmp.
 
 	case ir.OMETHEXPR:
@@ -499,9 +470,6 @@ func inlcopy(n ir.Node) ir.Node {
 			// x.Func.Body for iexport and local inlining.
 			oldfn := x.Func
 			newfn := ir.NewFunc(oldfn.Pos())
-			if oldfn.ClosureCalled() {
-				newfn.SetClosureCalled(true)
-			}
 			m.(*ir.ClosureExpr).Func = newfn
 			newfn.Nname = ir.NewNameAt(oldfn.Nname.Pos(), oldfn.Nname.Sym())
 			// XXX OK to share fn.Type() ??
@@ -544,37 +512,6 @@ func InlineCalls(fn *ir.Func) {
 	ir.CurFunc = savefn
 }
 
-// Turn an OINLCALL into a statement.
-func inlconv2stmt(inlcall *ir.InlinedCallExpr) ir.Node {
-	n := ir.NewBlockStmt(inlcall.Pos(), nil)
-	n.List = inlcall.Init()
-	n.List.Append(inlcall.Body.Take()...)
-	return n
-}
-
-// Turn an OINLCALL into a single valued expression.
-// The result of inlconv2expr MUST be assigned back to n, e.g.
-// 	n.Left = inlconv2expr(n.Left)
-func inlconv2expr(n *ir.InlinedCallExpr) ir.Node {
-	r := n.ReturnVars[0]
-	return ir.InitExpr(append(n.Init(), n.Body...), r)
-}
-
-// Turn the rlist (with the return values) of the OINLCALL in
-// n into an expression list lumping the ninit and body
-// containing the inlined statements on the first list element so
-// order will be preserved. Used in return, oas2func and call
-// statements.
-func inlconv2list(n *ir.InlinedCallExpr) []ir.Node {
-	if n.Op() != ir.OINLCALL || len(n.ReturnVars) == 0 {
-		base.Fatalf("inlconv2list %+v\n", n)
-	}
-
-	s := n.ReturnVars
-	s[0] = ir.InitExpr(append(n.Init(), n.Body...), s[0])
-	return s
-}
-
 // inlnode recurses over the tree to find inlineable calls, which will
 // be turned into OINLCALLs by mkinlcall. When the recursion comes
 // back up will examine left, right, list, rlist, ninit, ntest, nincr,
@@ -597,7 +534,9 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool, edit func(ir.No
 	case ir.ODEFER, ir.OGO:
 		n := n.(*ir.GoDeferStmt)
 		switch call := n.Call; call.Op() {
-		case ir.OCALLFUNC, ir.OCALLMETH:
+		case ir.OCALLMETH:
+			base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck")
+		case ir.OCALLFUNC:
 			call := call.(*ir.CallExpr)
 			call.NoInline = true
 		}
@@ -607,11 +546,18 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool, edit func(ir.No
 	case ir.OCLOSURE:
 		return n
 	case ir.OCALLMETH:
-		// Prevent inlining some reflect.Value methods when using checkptr,
-		// even when package reflect was compiled without it (#35073).
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
+	case ir.OCALLFUNC:
 		n := n.(*ir.CallExpr)
-		if s := ir.MethodExprName(n.X).Sym(); base.Debug.Checkptr != 0 && types.IsReflectPkg(s.Pkg) && (s.Name == "Value.UnsafeAddr" || s.Name == "Value.Pointer") {
-			return n
+		if n.X.Op() == ir.OMETHEXPR {
+			// Prevent inlining some reflect.Value methods when using checkptr,
+			// even when package reflect was compiled without it (#35073).
+			if meth := ir.MethodExprName(n.X); meth != nil {
+				s := meth.Sym()
+				if base.Debug.Checkptr != 0 && types.IsReflectPkg(s.Pkg) && (s.Name == "Value.UnsafeAddr" || s.Name == "Value.Pointer") {
+					return n
+				}
+			}
 		}
 	}
 
@@ -619,31 +565,18 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool, edit func(ir.No
 
 	ir.EditChildren(n, edit)
 
-	if as := n; as.Op() == ir.OAS2FUNC {
-		as := as.(*ir.AssignListStmt)
-		if as.Rhs[0].Op() == ir.OINLCALL {
-			as.Rhs = inlconv2list(as.Rhs[0].(*ir.InlinedCallExpr))
-			as.SetOp(ir.OAS2)
-			as.SetTypecheck(0)
-			n = typecheck.Stmt(as)
-		}
-	}
-
 	// with all the branches out of the way, it is now time to
 	// transmogrify this node itself unless inhibited by the
 	// switch at the top of this function.
 	switch n.Op() {
-	case ir.OCALLFUNC, ir.OCALLMETH:
-		n := n.(*ir.CallExpr)
-		if n.NoInline {
-			return n
-		}
-	}
+	case ir.OCALLMETH:
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
 
-	var call *ir.CallExpr
-	switch n.Op() {
 	case ir.OCALLFUNC:
-		call = n.(*ir.CallExpr)
+		call := n.(*ir.CallExpr)
+		if call.NoInline {
+			break
+		}
 		if base.Flag.LowerM > 3 {
 			fmt.Printf("%v:call to func %+v\n", ir.Line(n), call.X)
 		}
@@ -653,38 +586,10 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool, edit func(ir.No
 		if fn := inlCallee(call.X); fn != nil && fn.Inl != nil {
 			n = mkinlcall(call, fn, maxCost, inlMap, edit)
 		}
-
-	case ir.OCALLMETH:
-		call = n.(*ir.CallExpr)
-		if base.Flag.LowerM > 3 {
-			fmt.Printf("%v:call to meth %v\n", ir.Line(n), call.X.(*ir.SelectorExpr).Sel)
-		}
-
-		// typecheck should have resolved ODOTMETH->type, whose nname points to the actual function.
-		if call.X.Type() == nil {
-			base.Fatalf("no function type for [%p] %+v\n", call.X, call.X)
-		}
-
-		n = mkinlcall(call, ir.MethodExprName(call.X).Func, maxCost, inlMap, edit)
 	}
 
 	base.Pos = lno
 
-	if n.Op() == ir.OINLCALL {
-		ic := n.(*ir.InlinedCallExpr)
-		switch call.Use {
-		default:
-			ir.Dump("call", call)
-			base.Fatalf("call missing use")
-		case ir.CallUseExpr:
-			n = inlconv2expr(ic)
-		case ir.CallUseStmt:
-			n = inlconv2stmt(ic)
-		case ir.CallUseList:
-			// leave for caller to convert
-		}
-	}
-
 	return n
 }
 
@@ -740,7 +645,12 @@ var inlgen int
 // when producing output for debugging the compiler itself.
 var SSADumpInline = func(*ir.Func) {}
 
-// If n is a call node (OCALLFUNC or OCALLMETH), and fn is an ONAME node for a
+// NewInline allows the inliner implementation to be overridden.
+// If it returns nil, the legacy inliner will handle this call
+// instead.
+var NewInline = func(call *ir.CallExpr, fn *ir.Func, inlIndex int) *ir.InlinedCallExpr { return nil }
+
+// If n is a OCALLFUNC node, and fn is an ONAME node for a
 // function with an inlinable body, return an OINLCALL node that can replace n.
 // The returned node's Ninit has the parameter assignments, the Nbody is the
 // inlined function body, and (List, Rlist) contain the (input, output)
@@ -793,38 +703,90 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	defer func() {
 		inlMap[fn] = false
 	}()
-	if base.Debug.TypecheckInl == 0 {
-		typecheck.ImportedBody(fn)
+
+	typecheck.FixVariadicCall(n)
+
+	parent := base.Ctxt.PosTable.Pos(n.Pos()).Base().InliningIndex()
+
+	sym := fn.Linksym()
+	inlIndex := base.Ctxt.InlTree.Add(parent, n.Pos(), sym)
+
+	if base.Flag.GenDwarfInl > 0 {
+		if !sym.WasInlined() {
+			base.Ctxt.DwFixups.SetPrecursorFunc(sym, fn)
+			sym.Set(obj.AttrWasInlined, true)
+		}
 	}
 
-	// We have a function node, and it has an inlineable body.
-	if base.Flag.LowerM > 1 {
-		fmt.Printf("%v: inlining call to %v %v { %v }\n", ir.Line(n), fn.Sym(), fn.Type(), ir.Nodes(fn.Inl.Body))
-	} else if base.Flag.LowerM != 0 {
+	if base.Flag.LowerM != 0 {
 		fmt.Printf("%v: inlining call to %v\n", ir.Line(n), fn)
 	}
 	if base.Flag.LowerM > 2 {
 		fmt.Printf("%v: Before inlining: %+v\n", ir.Line(n), n)
 	}
 
+	res := NewInline(n, fn, inlIndex)
+	if res == nil {
+		res = oldInline(n, fn, inlIndex)
+	}
+
+	// transitive inlining
+	// might be nice to do this before exporting the body,
+	// but can't emit the body with inlining expanded.
+	// instead we emit the things that the body needs
+	// and each use must redo the inlining.
+	// luckily these are small.
+	ir.EditChildren(res, edit)
+
+	if base.Flag.LowerM > 2 {
+		fmt.Printf("%v: After inlining %+v\n\n", ir.Line(res), res)
+	}
+
+	return res
+}
+
+// CalleeEffects appends any side effects from evaluating callee to init.
+func CalleeEffects(init *ir.Nodes, callee ir.Node) {
+	for {
+		switch callee.Op() {
+		case ir.ONAME, ir.OCLOSURE, ir.OMETHEXPR:
+			return // done
+
+		case ir.OCONVNOP:
+			conv := callee.(*ir.ConvExpr)
+			init.Append(ir.TakeInit(conv)...)
+			callee = conv.X
+
+		case ir.OINLCALL:
+			ic := callee.(*ir.InlinedCallExpr)
+			init.Append(ir.TakeInit(ic)...)
+			init.Append(ic.Body.Take()...)
+			callee = ic.SingleResult()
+
+		default:
+			base.FatalfAt(callee.Pos(), "unexpected callee expression: %v", callee)
+		}
+	}
+}
+
+// oldInline creates an InlinedCallExpr to replace the given call
+// expression. fn is the callee function to be inlined. inlIndex is
+// the inlining tree position index, for use with src.NewInliningBase
+// when rewriting positions.
+func oldInline(call *ir.CallExpr, fn *ir.Func, inlIndex int) *ir.InlinedCallExpr {
+	if base.Debug.TypecheckInl == 0 {
+		typecheck.ImportedBody(fn)
+	}
+
 	SSADumpInline(fn)
 
-	ninit := n.Init()
+	ninit := call.Init()
 
 	// For normal function calls, the function callee expression
-	// may contain side effects (e.g., added by addinit during
-	// inlconv2expr or inlconv2list). Make sure to preserve these,
+	// may contain side effects. Make sure to preserve these,
 	// if necessary (#42703).
-	if n.Op() == ir.OCALLFUNC {
-		callee := n.X
-		for callee.Op() == ir.OCONVNOP {
-			conv := callee.(*ir.ConvExpr)
-			ninit.Append(ir.TakeInit(conv)...)
-			callee = conv.X
-		}
-		if callee.Op() != ir.ONAME && callee.Op() != ir.OCLOSURE && callee.Op() != ir.OMETHEXPR {
-			base.Fatalf("unexpected callee expression: %v", callee)
-		}
+	if call.Op() == ir.OCALLFUNC {
+		CalleeEffects(&ninit, call.X)
 	}
 
 	// Make temp names to use instead of the originals.
@@ -854,25 +816,6 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	}
 
 	// We can delay declaring+initializing result parameters if:
-	// (1) there's exactly one "return" statement in the inlined function;
-	// (2) it's not an empty return statement (#44355); and
-	// (3) the result parameters aren't named.
-	delayretvars := true
-
-	nreturns := 0
-	ir.VisitList(ir.Nodes(fn.Inl.Body), func(n ir.Node) {
-		if n, ok := n.(*ir.ReturnStmt); ok {
-			nreturns++
-			if len(n.Results) == 0 {
-				delayretvars = false // empty return statement (case 2)
-			}
-		}
-	})
-
-	if nreturns != 1 {
-		delayretvars = false // not exactly one return statement (case 1)
-	}
-
 	// temporaries for return values.
 	var retvars []ir.Node
 	for i, t := range fn.Type().Results().Fields().Slice() {
@@ -882,7 +825,6 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 			m = inlvar(n)
 			m = typecheck.Expr(m).(*ir.Name)
 			inlvars[n] = m
-			delayretvars = false // found a named result parameter (case 3)
 		} else {
 			// anonymous return values, synthesize names for use in assignment that replaces return
 			m = retvar(t, i)
@@ -905,61 +847,23 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	// Assign arguments to the parameters' temp names.
 	as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil)
 	as.Def = true
-	if n.Op() == ir.OCALLMETH {
-		sel := n.X.(*ir.SelectorExpr)
-		if sel.X == nil {
-			base.Fatalf("method call without receiver: %+v", n)
-		}
-		as.Rhs.Append(sel.X)
+	if call.Op() == ir.OCALLMETH {
+		base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck")
 	}
-	as.Rhs.Append(n.Args...)
-
-	// For non-dotted calls to variadic functions, we assign the
-	// variadic parameter's temp name separately.
-	var vas *ir.AssignStmt
+	as.Rhs.Append(call.Args...)
 
 	if recv := fn.Type().Recv(); recv != nil {
 		as.Lhs.Append(inlParam(recv, as, inlvars))
 	}
 	for _, param := range fn.Type().Params().Fields().Slice() {
-		// For ordinary parameters or variadic parameters in
-		// dotted calls, just add the variable to the
-		// assignment list, and we're done.
-		if !param.IsDDD() || n.IsDDD {
-			as.Lhs.Append(inlParam(param, as, inlvars))
-			continue
-		}
-
-		// Otherwise, we need to collect the remaining values
-		// to pass as a slice.
-
-		x := len(as.Lhs)
-		for len(as.Lhs) < len(as.Rhs) {
-			as.Lhs.Append(argvar(param.Type, len(as.Lhs)))
-		}
-		varargs := as.Lhs[x:]
-
-		vas = ir.NewAssignStmt(base.Pos, nil, nil)
-		vas.X = inlParam(param, vas, inlvars)
-		if len(varargs) == 0 {
-			vas.Y = typecheck.NodNil()
-			vas.Y.SetType(param.Type)
-		} else {
-			lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(param.Type), nil)
-			lit.List = varargs
-			vas.Y = lit
-		}
+		as.Lhs.Append(inlParam(param, as, inlvars))
 	}
 
 	if len(as.Rhs) != 0 {
 		ninit.Append(typecheck.Stmt(as))
 	}
 
-	if vas != nil {
-		ninit.Append(typecheck.Stmt(vas))
-	}
-
-	if !delayretvars {
+	if !fn.Inl.CanDelayResults {
 		// Zero the return parameters.
 		for _, n := range retvars {
 			ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name)))
@@ -972,40 +876,21 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 
 	inlgen++
 
-	parent := -1
-	if b := base.Ctxt.PosTable.Pos(n.Pos()).Base(); b != nil {
-		parent = b.InliningIndex()
-	}
-
-	sym := fn.Linksym()
-	newIndex := base.Ctxt.InlTree.Add(parent, n.Pos(), sym)
-
 	// Add an inline mark just before the inlined body.
 	// This mark is inline in the code so that it's a reasonable spot
 	// to put a breakpoint. Not sure if that's really necessary or not
 	// (in which case it could go at the end of the function instead).
 	// Note issue 28603.
-	inlMark := ir.NewInlineMarkStmt(base.Pos, types.BADWIDTH)
-	inlMark.SetPos(n.Pos().WithIsStmt())
-	inlMark.Index = int64(newIndex)
-	ninit.Append(inlMark)
-
-	if base.Flag.GenDwarfInl > 0 {
-		if !sym.WasInlined() {
-			base.Ctxt.DwFixups.SetPrecursorFunc(sym, fn)
-			sym.Set(obj.AttrWasInlined, true)
-		}
-	}
+	ninit.Append(ir.NewInlineMarkStmt(call.Pos().WithIsStmt(), int64(inlIndex)))
 
 	subst := inlsubst{
-		retlabel:     retlabel,
-		retvars:      retvars,
-		delayretvars: delayretvars,
-		inlvars:      inlvars,
-		defnMarker:   ir.NilExpr{},
-		bases:        make(map[*src.PosBase]*src.PosBase),
-		newInlIndex:  newIndex,
-		fn:           fn,
+		retlabel:    retlabel,
+		retvars:     retvars,
+		inlvars:     inlvars,
+		defnMarker:  ir.NilExpr{},
+		bases:       make(map[*src.PosBase]*src.PosBase),
+		newInlIndex: inlIndex,
+		fn:          fn,
 	}
 	subst.edit = subst.node
 
@@ -1026,26 +911,11 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 
 	//dumplist("ninit post", ninit);
 
-	call := ir.NewInlinedCallExpr(base.Pos, nil, nil)
-	*call.PtrInit() = ninit
-	call.Body = body
-	call.ReturnVars = retvars
-	call.SetType(n.Type())
-	call.SetTypecheck(1)
-
-	// transitive inlining
-	// might be nice to do this before exporting the body,
-	// but can't emit the body with inlining expanded.
-	// instead we emit the things that the body needs
-	// and each use must redo the inlining.
-	// luckily these are small.
-	ir.EditChildren(call, edit)
-
-	if base.Flag.LowerM > 2 {
-		fmt.Printf("%v: After inlining %+v\n\n", ir.Line(call), call)
-	}
-
-	return call
+	res := ir.NewInlinedCallExpr(base.Pos, body, retvars)
+	res.SetInit(ninit)
+	res.SetType(call.Type())
+	res.SetTypecheck(1)
+	return res
 }
 
 // Every time we expand a function we generate a new set of tmpnames,
@@ -1058,8 +928,10 @@ func inlvar(var_ *ir.Name) *ir.Name {
 
 	n := typecheck.NewName(var_.Sym())
 	n.SetType(var_.Type())
+	n.SetTypecheck(1)
 	n.Class = ir.PAUTO
 	n.SetUsed(true)
+	n.SetAutoTemp(var_.AutoTemp())
 	n.Curfn = ir.CurFunc // the calling function, not the called one
 	n.SetAddrtaken(var_.Addrtaken())
 
@@ -1071,18 +943,7 @@ func inlvar(var_ *ir.Name) *ir.Name {
 func retvar(t *types.Field, i int) *ir.Name {
 	n := typecheck.NewName(typecheck.LookupNum("~R", i))
 	n.SetType(t.Type)
-	n.Class = ir.PAUTO
-	n.SetUsed(true)
-	n.Curfn = ir.CurFunc // the calling function, not the called one
-	ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n)
-	return n
-}
-
-// Synthesize a variable to store the inlined function's arguments
-// when they come from a multiple return call.
-func argvar(t *types.Type, i int) ir.Node {
-	n := typecheck.NewName(typecheck.LookupNum("~arg", i))
-	n.SetType(t.Elem())
+	n.SetTypecheck(1)
 	n.Class = ir.PAUTO
 	n.SetUsed(true)
 	n.Curfn = ir.CurFunc // the calling function, not the called one
@@ -1099,10 +960,6 @@ type inlsubst struct {
 	// Temporary result variables.
 	retvars []ir.Node
 
-	// Whether result variables should be initialized at the
-	// "return" statement.
-	delayretvars bool
-
 	inlvars map[*ir.Name]*ir.Name
 	// defnMarker is used to mark a Node for reassignment.
 	// inlsubst.clovar set this during creating new ONAME.
@@ -1124,6 +981,10 @@ type inlsubst struct {
 	newclofn *ir.Func
 
 	fn *ir.Func // For debug -- the func that is being inlined
+
+	// If true, then don't update source positions during substitution
+	// (retain old source positions).
+	noPosUpdate bool
 }
 
 // list inlines a list of nodes.
@@ -1153,17 +1014,21 @@ func (subst *inlsubst) fields(oldt *types.Type) []*types.Field {
 // clovar creates a new ONAME node for a local variable or param of a closure
 // inside a function being inlined.
 func (subst *inlsubst) clovar(n *ir.Name) *ir.Name {
-	// TODO(danscales): want to get rid of this shallow copy, with code like the
-	// following, but it is hard to copy all the necessary flags in a maintainable way.
-	// m := ir.NewNameAt(n.Pos(), n.Sym())
-	// m.Class = n.Class
-	// m.SetType(n.Type())
-	// m.SetTypecheck(1)
-	//if n.IsClosureVar() {
-	//	m.SetIsClosureVar(true)
-	//}
-	m := &ir.Name{}
-	*m = *n
+	m := ir.NewNameAt(n.Pos(), n.Sym())
+	m.Class = n.Class
+	m.SetType(n.Type())
+	m.SetTypecheck(1)
+	if n.IsClosureVar() {
+		m.SetIsClosureVar(true)
+	}
+	if n.Addrtaken() {
+		m.SetAddrtaken(true)
+	}
+	if n.Used() {
+		m.SetUsed(true)
+	}
+	m.Defn = n.Defn
+
 	m.Curfn = subst.newclofn
 
 	switch defn := n.Defn.(type) {
@@ -1218,31 +1083,23 @@ func (subst *inlsubst) clovar(n *ir.Name) *ir.Name {
 // closure does the necessary substitions for a ClosureExpr n and returns the new
 // closure node.
 func (subst *inlsubst) closure(n *ir.ClosureExpr) ir.Node {
-	m := ir.Copy(n)
-	m.SetPos(subst.updatedPos(m.Pos()))
-	ir.EditChildren(m, subst.edit)
+	// Prior to the subst edit, set a flag in the inlsubst to
+	// indicated that we don't want to update the source positions in
+	// the new closure. If we do this, it will appear that the closure
+	// itself has things inlined into it, which is not the case. See
+	// issue #46234 for more details.
+	defer func(prev bool) { subst.noPosUpdate = prev }(subst.noPosUpdate)
+	subst.noPosUpdate = true
 
 	//fmt.Printf("Inlining func %v with closure into %v\n", subst.fn, ir.FuncName(ir.CurFunc))
 
-	// The following is similar to funcLit
 	oldfn := n.Func
-	newfn := ir.NewFunc(oldfn.Pos())
-	// These three lines are not strictly necessary, but just to be clear
-	// that new function needs to redo typechecking and inlinability.
-	newfn.SetTypecheck(0)
-	newfn.SetInlinabilityChecked(false)
-	newfn.Inl = nil
-	newfn.SetIsHiddenClosure(true)
-	newfn.Nname = ir.NewNameAt(n.Pos(), ir.BlankNode.Sym())
-	newfn.Nname.Func = newfn
+	newfn := ir.NewClosureFunc(oldfn.Pos(), true)
+
 	// Ntype can be nil for -G=3 mode.
 	if oldfn.Nname.Ntype != nil {
 		newfn.Nname.Ntype = subst.node(oldfn.Nname.Ntype).(ir.Ntype)
 	}
-	newfn.Nname.Defn = newfn
-
-	m.(*ir.ClosureExpr).Func = newfn
-	newfn.OClosure = m.(*ir.ClosureExpr)
 
 	if subst.newclofn != nil {
 		//fmt.Printf("Inlining a closure with a nested closure\n")
@@ -1292,13 +1149,9 @@ func (subst *inlsubst) closure(n *ir.ClosureExpr) ir.Node {
 
 	// Actually create the named function for the closure, now that
 	// the closure is inlined in a specific function.
-	m.SetTypecheck(0)
-	if oldfn.ClosureCalled() {
-		typecheck.Callee(m)
-	} else {
-		typecheck.Expr(m)
-	}
-	return m
+	newclo := newfn.OClosure
+	newclo.SetInit(subst.list(n.Init()))
+	return typecheck.Expr(newclo)
 }
 
 // node recursively copies a node from the saved pristine body of the
@@ -1380,7 +1233,7 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 			}
 			as.Rhs = subst.list(n.Results)
 
-			if subst.delayretvars {
+			if subst.fn.Inl.CanDelayResults {
 				for _, n := range as.Lhs {
 					as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name)))
 					n.Name().Defn = as
@@ -1445,6 +1298,9 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 }
 
 func (subst *inlsubst) updatedPos(xpos src.XPos) src.XPos {
+	if subst.noPosUpdate {
+		return xpos
+	}
 	pos := base.Ctxt.PosTable.Pos(xpos)
 	oldbase := pos.Base() // can be nil
 	newbase := subst.bases[oldbase]
diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index f70645f0791..dc28483907a 100644
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -142,28 +142,15 @@ func (n *BinaryExpr) SetOp(op Op) {
 	}
 }
 
-// A CallUse records how the result of the call is used:
-type CallUse byte
-
-const (
-	_ CallUse = iota
-
-	CallUseExpr // single expression result is used
-	CallUseList // list of results are used
-	CallUseStmt // results not used - call is a statement
-)
-
 // A CallExpr is a function call X(Args).
 type CallExpr struct {
 	miniExpr
 	origNode
-	X               Node
-	Args            Nodes
-	KeepAlive       []*Name // vars to be kept alive until call returns
-	IsDDD           bool
-	Use             CallUse
-	NoInline        bool
-	PreserveClosure bool // disable directClosureCall for this call
+	X         Node
+	Args      Nodes
+	KeepAlive []*Name // vars to be kept alive until call returns
+	IsDDD     bool
+	NoInline  bool
 }
 
 func NewCallExpr(pos src.XPos, op Op, fun Node, args []Node) *CallExpr {
@@ -181,8 +168,12 @@ func (n *CallExpr) SetOp(op Op) {
 	switch op {
 	default:
 		panic(n.no("SetOp " + op.String()))
-	case OCALL, OCALLFUNC, OCALLINTER, OCALLMETH,
-		OAPPEND, ODELETE, OGETG, OMAKE, OPRINT, OPRINTN, ORECOVER:
+	case OAPPEND,
+		OCALL, OCALLFUNC, OCALLINTER, OCALLMETH,
+		ODELETE,
+		OGETG, OGETCALLERPC, OGETCALLERSP,
+		OMAKE, OPRINT, OPRINTN,
+		ORECOVER, ORECOVERFP:
 		n.op = op
 	}
 }
@@ -192,8 +183,10 @@ type ClosureExpr struct {
 	miniExpr
 	Func     *Func `mknode:"-"`
 	Prealloc *Name
+	IsGoWrap bool // whether this is wrapper closure of a go statement
 }
 
+// Deprecated: Use NewClosureFunc instead.
 func NewClosureExpr(pos src.XPos, fn *Func) *ClosureExpr {
 	n := &ClosureExpr{Func: fn}
 	n.op = OCLOSURE
@@ -277,7 +270,7 @@ func (n *ConvExpr) SetOp(op Op) {
 	switch op {
 	default:
 		panic(n.no("SetOp " + op.String()))
-	case OCONV, OCONVIFACE, OCONVNOP, OBYTES2STR, OBYTES2STRTMP, ORUNES2STR, OSTR2BYTES, OSTR2BYTESTMP, OSTR2RUNES, ORUNESTR, OSLICE2ARRPTR:
+	case OCONV, OCONVIFACE, OCONVIDATA, OCONVNOP, OBYTES2STR, OBYTES2STRTMP, ORUNES2STR, OSTR2BYTES, OSTR2BYTESTMP, OSTR2RUNES, ORUNESTR, OSLICE2ARRPTR:
 		n.op = op
 	}
 }
@@ -323,26 +316,24 @@ func NewKeyExpr(pos src.XPos, key, value Node) *KeyExpr {
 // A StructKeyExpr is an Field: Value composite literal key.
 type StructKeyExpr struct {
 	miniExpr
-	Field  *types.Sym
-	Value  Node
-	Offset int64
+	Field *types.Field
+	Value Node
 }
 
-func NewStructKeyExpr(pos src.XPos, field *types.Sym, value Node) *StructKeyExpr {
+func NewStructKeyExpr(pos src.XPos, field *types.Field, value Node) *StructKeyExpr {
 	n := &StructKeyExpr{Field: field, Value: value}
 	n.pos = pos
 	n.op = OSTRUCTKEY
-	n.Offset = types.BADWIDTH
 	return n
 }
 
-func (n *StructKeyExpr) Sym() *types.Sym { return n.Field }
+func (n *StructKeyExpr) Sym() *types.Sym { return n.Field.Sym }
 
 // An InlinedCallExpr is an inlined function call.
 type InlinedCallExpr struct {
 	miniExpr
 	Body       Nodes
-	ReturnVars Nodes
+	ReturnVars Nodes // must be side-effect free
 }
 
 func NewInlinedCallExpr(pos src.XPos, body, retvars []Node) *InlinedCallExpr {
@@ -354,6 +345,21 @@ func NewInlinedCallExpr(pos src.XPos, body, retvars []Node) *InlinedCallExpr {
 	return n
 }
 
+func (n *InlinedCallExpr) SingleResult() Node {
+	if have := len(n.ReturnVars); have != 1 {
+		base.FatalfAt(n.Pos(), "inlined call has %v results, expected 1", have)
+	}
+	if !n.Type().HasShape() && n.ReturnVars[0].Type().HasShape() {
+		// If the type of the call is not a shape, but the type of the return value
+		// is a shape, we need to do an implicit conversion, so the real type
+		// of n is maintained.
+		r := NewConvExpr(n.Pos(), OCONVNOP, n.Type(), n.ReturnVars[0])
+		r.SetTypecheck(1)
+		return r
+	}
+	return n.ReturnVars[0]
+}
+
 // A LogicalExpr is a expression X Op Y where Op is && or ||.
 // It is separate from BinaryExpr to make room for statements
 // that must be executed before Y but after X.
@@ -448,6 +454,20 @@ func (n *ParenExpr) SetOTYPE(t *types.Type) {
 	t.SetNod(n)
 }
 
+// A RawOrigExpr represents an arbitrary Go expression as a string value.
+// When printed in diagnostics, the string value is written out exactly as-is.
+type RawOrigExpr struct {
+	miniExpr
+	Raw string
+}
+
+func NewRawOrigExpr(pos src.XPos, op Op, raw string) *RawOrigExpr {
+	n := &RawOrigExpr{Raw: raw}
+	n.pos = pos
+	n.op = op
+	return n
+}
+
 // A ResultExpr represents a direct access to a result.
 type ResultExpr struct {
 	miniExpr
@@ -494,10 +514,15 @@ func NewNameOffsetExpr(pos src.XPos, name *Name, offset int64, typ *types.Type)
 // A SelectorExpr is a selector expression X.Sel.
 type SelectorExpr struct {
 	miniExpr
-	X         Node
-	Sel       *types.Sym
+	X Node
+	// Sel is the name of the field or method being selected, without (in the
+	// case of methods) any preceding type specifier. If the field/method is
+	// exported, than the Sym uses the local package regardless of the package
+	// of the containing type.
+	Sel *types.Sym
+	// The actual selected field - may not be filled in until typechecking.
 	Selection *types.Field
-	Prealloc  *Name // preallocated storage for OCALLPART, if any
+	Prealloc  *Name // preallocated storage for OMETHVALUE, if any
 }
 
 func NewSelectorExpr(pos src.XPos, op Op, x Node, sel *types.Sym) *SelectorExpr {
@@ -511,7 +536,7 @@ func (n *SelectorExpr) SetOp(op Op) {
 	switch op {
 	default:
 		panic(n.no("SetOp " + op.String()))
-	case OXDOT, ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OCALLPART, OMETHEXPR:
+	case OXDOT, ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OMETHVALUE, OMETHEXPR:
 		n.op = op
 	}
 }
@@ -652,6 +677,38 @@ func (n *TypeAssertExpr) SetOp(op Op) {
 	}
 }
 
+// A DynamicTypeAssertExpr asserts that X is of dynamic type T.
+type DynamicTypeAssertExpr struct {
+	miniExpr
+	X Node
+	// N = not an interface
+	// E = empty interface
+	// I = nonempty interface
+	// For E->N, T is a *runtime.type for N
+	// For I->N, T is a *runtime.itab for N+I
+	// For E->I, T is a *runtime.type for I
+	// For I->I, ditto
+	// For I->E, T is a *runtime.type for interface{} (unnecessary, but just to fill in the slot)
+	// For E->E, ditto
+	T Node
+}
+
+func NewDynamicTypeAssertExpr(pos src.XPos, op Op, x, t Node) *DynamicTypeAssertExpr {
+	n := &DynamicTypeAssertExpr{X: x, T: t}
+	n.pos = pos
+	n.op = op
+	return n
+}
+
+func (n *DynamicTypeAssertExpr) SetOp(op Op) {
+	switch op {
+	default:
+		panic(n.no("SetOp " + op.String()))
+	case ODYNAMICDOTTYPE, ODYNAMICDOTTYPE2:
+		n.op = op
+	}
+}
+
 // A UnaryExpr is a unary expression Op X,
 // or Op(X) for a builtin function that does not end up being a call.
 type UnaryExpr struct {
@@ -678,6 +735,11 @@ func (n *UnaryExpr) SetOp(op Op) {
 	}
 }
 
+// Probably temporary: using Implicit() flag to mark generic function nodes that
+// are called to make getGfInfo analysis easier in one pre-order pass.
+func (n *InstExpr) Implicit() bool     { return n.flags&miniExprImplicit != 0 }
+func (n *InstExpr) SetImplicit(b bool) { n.flags.set(miniExprImplicit, b) }
+
 // An InstExpr is a generic function or type instantiation.
 type InstExpr struct {
 	miniExpr
@@ -773,6 +835,11 @@ func StaticValue(n Node) Node {
 			continue
 		}
 
+		if n.Op() == OINLCALL {
+			n = n.(*InlinedCallExpr).SingleResult()
+			continue
+		}
+
 		n1 := staticValue1(n)
 		if n1 == nil {
 			return n
@@ -1071,7 +1138,7 @@ func MethodExprName(n Node) *Name {
 // MethodExprFunc is like MethodExprName, but returns the types.Field instead.
 func MethodExprFunc(n Node) *types.Field {
 	switch n.Op() {
-	case ODOTMETH, OMETHEXPR, OCALLPART:
+	case ODOTMETH, OMETHEXPR, OMETHVALUE:
 		return n.(*SelectorExpr).Selection
 	}
 	base.Fatalf("unexpected node: %v (%v)", n, n.Op())
diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index f2ae0f7606e..d19fe453efc 100644
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -185,6 +185,7 @@ var OpPrec = []int{
 	OCLOSE:         8,
 	OCOMPLIT:       8,
 	OCONVIFACE:     8,
+	OCONVIDATA:     8,
 	OCONVNOP:       8,
 	OCONV:          8,
 	OCOPY:          8,
@@ -237,7 +238,7 @@ var OpPrec = []int{
 	ODOTTYPE:       8,
 	ODOT:           8,
 	OXDOT:          8,
-	OCALLPART:      8,
+	OMETHVALUE:     8,
 	OMETHEXPR:      8,
 	OPLUS:          7,
 	ONOT:           7,
@@ -546,7 +547,7 @@ func exprFmt(n Node, s fmt.State, prec int) {
 				n = nn.X
 				continue
 			}
-		case OCONV, OCONVNOP, OCONVIFACE:
+		case OCONV, OCONVNOP, OCONVIFACE, OCONVIDATA:
 			nn := nn.(*ConvExpr)
 			if nn.Implicit() {
 				n = nn.X
@@ -567,6 +568,11 @@ func exprFmt(n Node, s fmt.State, prec int) {
 		return
 	}
 
+	if n, ok := n.(*RawOrigExpr); ok {
+		fmt.Fprint(s, n.Raw)
+		return
+	}
+
 	switch n.Op() {
 	case OPAREN:
 		n := n.(*ParenExpr)
@@ -709,6 +715,10 @@ func exprFmt(n Node, s fmt.State, prec int) {
 				fmt.Fprintf(s, "... argument")
 				return
 			}
+			if typ := n.Type(); typ != nil {
+				fmt.Fprintf(s, "%v{%s}", typ, ellipsisIf(len(n.List) != 0))
+				return
+			}
 			if n.Ntype != nil {
 				fmt.Fprintf(s, "%v{%s}", n.Ntype, ellipsisIf(len(n.List) != 0))
 				return
@@ -752,7 +762,7 @@ func exprFmt(n Node, s fmt.State, prec int) {
 		n := n.(*StructKeyExpr)
 		fmt.Fprintf(s, "%v:%v", n.Field, n.Value)
 
-	case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH, OCALLPART, OMETHEXPR:
+	case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH, OMETHVALUE, OMETHEXPR:
 		n := n.(*SelectorExpr)
 		exprFmt(n.X, s, nprec)
 		if n.Sel == nil {
@@ -804,6 +814,7 @@ func exprFmt(n Node, s fmt.State, prec int) {
 
 	case OCONV,
 		OCONVIFACE,
+		OCONVIDATA,
 		OCONVNOP,
 		OBYTES2STR,
 		ORUNES2STR,
@@ -854,6 +865,15 @@ func exprFmt(n Node, s fmt.State, prec int) {
 		}
 		fmt.Fprintf(s, "(%.v)", n.Args)
 
+	case OINLCALL:
+		n := n.(*InlinedCallExpr)
+		// TODO(mdempsky): Print Init and/or Body?
+		if len(n.ReturnVars) == 1 {
+			fmt.Fprintf(s, "%v", n.ReturnVars[0])
+			return
+		}
+		fmt.Fprintf(s, "(.%v)", n.ReturnVars)
+
 	case OMAKEMAP, OMAKECHAN, OMAKESLICE:
 		n := n.(*MakeExpr)
 		if n.Cap != nil {
@@ -986,7 +1006,7 @@ func (l Nodes) Format(s fmt.State, verb rune) {
 
 // Dump prints the message s followed by a debug dump of n.
 func Dump(s string, n Node) {
-	fmt.Printf("%s [%p]%+v\n", s, n, n)
+	fmt.Printf("%s%+v\n", s, n)
 }
 
 // DumpList prints the message s followed by a debug dump of each node in the list.
@@ -1114,16 +1134,21 @@ func dumpNodeHeader(w io.Writer, n Node) {
 	}
 
 	if n.Pos().IsKnown() {
-		pfx := ""
+		fmt.Fprint(w, " # ")
 		switch n.Pos().IsStmt() {
 		case src.PosNotStmt:
-			pfx = "_" // "-" would be confusing
+			fmt.Fprint(w, "_") // "-" would be confusing
 		case src.PosIsStmt:
-			pfx = "+"
+			fmt.Fprint(w, "+")
+		}
+		for i, pos := range base.Ctxt.AllPos(n.Pos(), nil) {
+			if i > 0 {
+				fmt.Fprint(w, ",")
+			}
+			// TODO(mdempsky): Print line pragma details too.
+			file := filepath.Base(pos.Filename())
+			fmt.Fprintf(w, "%s:%d:%d", file, pos.Line(), pos.Col())
 		}
-		pos := base.Ctxt.PosTable.Pos(n.Pos())
-		file := filepath.Base(pos.Filename())
-		fmt.Fprintf(w, " # %s%s:%d", pfx, file, pos.Line())
 	}
 }
 
diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 20fe965711d..269b6f14ec1 100644
--- a/src/cmd/compile/internal/ir/func.go
+++ b/src/cmd/compile/internal/ir/func.go
@@ -9,6 +9,7 @@ import (
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
 	"cmd/internal/src"
+	"fmt"
 )
 
 // A Func corresponds to a single function in a Go program
@@ -39,14 +40,14 @@ import (
 // constructs a fresh node.
 //
 // A method value (t.M) is represented by ODOTMETH/ODOTINTER
-// when it is called directly and by OCALLPART otherwise.
+// when it is called directly and by OMETHVALUE otherwise.
 // These are like method expressions, except that for ODOTMETH/ODOTINTER,
 // the method name is stored in Sym instead of Right.
-// Each OCALLPART ends up being implemented as a new
+// Each OMETHVALUE ends up being implemented as a new
 // function, a bit like a closure, with its own ODCLFUNC.
-// The OCALLPART uses n.Func to record the linkage to
+// The OMETHVALUE uses n.Func to record the linkage to
 // the generated ODCLFUNC, but there is no
-// pointer from the Func back to the OCALLPART.
+// pointer from the Func back to the OMETHVALUE.
 type Func struct {
 	miniNode
 	Body Nodes
@@ -166,6 +167,11 @@ type Inline struct {
 	// another package is imported.
 	Dcl  []*Name
 	Body []Node
+
+	// CanDelayResults reports whether it's safe for the inliner to delay
+	// initializing the result parameters until immediately before the
+	// "return" statement.
+	CanDelayResults bool
 }
 
 // A Mark represents a scope boundary.
@@ -196,7 +202,7 @@ const (
 	funcExportInline             // include inline body in export data
 	funcInstrumentBody           // add race/msan instrumentation during SSA construction
 	funcOpenCodedDeferDisallowed // can't do open-coded defers
-	funcClosureCalled            // closure is only immediately called
+	funcClosureCalled            // closure is only immediately called; used by escape analysis
 )
 
 type SymAndPos struct {
@@ -272,6 +278,17 @@ func PkgFuncName(f *Func) string {
 
 var CurFunc *Func
 
+// WithFunc invokes do with CurFunc and base.Pos set to curfn and
+// curfn.Pos(), respectively, and then restores their previous values
+// before returning.
+func WithFunc(curfn *Func, do func()) {
+	oldfn, oldpos := CurFunc, base.Pos
+	defer func() { CurFunc, base.Pos = oldfn, oldpos }()
+
+	CurFunc, base.Pos = curfn, curfn.Pos()
+	do()
+}
+
 func FuncSymName(s *types.Sym) string {
 	return s.Name + "·f"
 }
@@ -279,7 +296,7 @@ func FuncSymName(s *types.Sym) string {
 // MarkFunc marks a node as a function.
 func MarkFunc(n *Name) {
 	if n.Op() != ONAME || n.Class != Pxxx {
-		base.Fatalf("expected ONAME/Pxxx node, got %v", n)
+		base.FatalfAt(n.Pos(), "expected ONAME/Pxxx node, got %v (%v/%v)", n, n.Op(), n.Class)
 	}
 
 	n.Class = PFUNC
@@ -296,8 +313,8 @@ func ClosureDebugRuntimeCheck(clo *ClosureExpr) {
 			base.WarnfAt(clo.Pos(), "stack closure, captured vars = %v", clo.Func.ClosureVars)
 		}
 	}
-	if base.Flag.CompilingRuntime && clo.Esc() == EscHeap {
-		base.ErrorfAt(clo.Pos(), "heap-allocated closure, not allowed in runtime")
+	if base.Flag.CompilingRuntime && clo.Esc() == EscHeap && !clo.IsGoWrap {
+		base.ErrorfAt(clo.Pos(), "heap-allocated closure %s, not allowed in runtime", FuncName(clo.Func))
 	}
 }
 
@@ -306,3 +323,109 @@ func ClosureDebugRuntimeCheck(clo *ClosureExpr) {
 func IsTrivialClosure(clo *ClosureExpr) bool {
 	return len(clo.Func.ClosureVars) == 0
 }
+
+// globClosgen is like Func.Closgen, but for the global scope.
+var globClosgen int32
+
+// closureName generates a new unique name for a closure within outerfn.
+func closureName(outerfn *Func) *types.Sym {
+	pkg := types.LocalPkg
+	outer := "glob."
+	prefix := "func"
+	gen := &globClosgen
+
+	if outerfn != nil {
+		if outerfn.OClosure != nil {
+			prefix = ""
+		}
+
+		pkg = outerfn.Sym().Pkg
+		outer = FuncName(outerfn)
+
+		// There may be multiple functions named "_". In those
+		// cases, we can't use their individual Closgens as it
+		// would lead to name clashes.
+		if !IsBlank(outerfn.Nname) {
+			gen = &outerfn.Closgen
+		}
+	}
+
+	*gen++
+	return pkg.Lookup(fmt.Sprintf("%s.%s%d", outer, prefix, *gen))
+}
+
+// NewClosureFunc creates a new Func to represent a function literal.
+// If hidden is true, then the closure is marked hidden (i.e., as a
+// function literal contained within another function, rather than a
+// package-scope variable initialization expression).
+func NewClosureFunc(pos src.XPos, hidden bool) *Func {
+	fn := NewFunc(pos)
+	fn.SetIsHiddenClosure(hidden)
+
+	fn.Nname = NewNameAt(pos, BlankNode.Sym())
+	fn.Nname.Func = fn
+	fn.Nname.Defn = fn
+
+	fn.OClosure = NewClosureExpr(pos, fn)
+
+	return fn
+}
+
+// NameClosure generates a unique for the given function literal,
+// which must have appeared within outerfn.
+func NameClosure(clo *ClosureExpr, outerfn *Func) {
+	fn := clo.Func
+	if fn.IsHiddenClosure() != (outerfn != nil) {
+		base.FatalfAt(clo.Pos(), "closure naming inconsistency: hidden %v, but outer %v", fn.IsHiddenClosure(), outerfn)
+	}
+
+	name := fn.Nname
+	if !IsBlank(name) {
+		base.FatalfAt(clo.Pos(), "closure already named: %v", name)
+	}
+
+	name.SetSym(closureName(outerfn))
+	MarkFunc(name)
+}
+
+// UseClosure checks that the ginen function literal has been setup
+// correctly, and then returns it as an expression.
+// It must be called after clo.Func.ClosureVars has been set.
+func UseClosure(clo *ClosureExpr, pkg *Package) Node {
+	fn := clo.Func
+	name := fn.Nname
+
+	if IsBlank(name) {
+		base.FatalfAt(fn.Pos(), "unnamed closure func: %v", fn)
+	}
+	// Caution: clo.Typecheck() is still 0 when UseClosure is called by
+	// tcClosure.
+	if fn.Typecheck() != 1 || name.Typecheck() != 1 {
+		base.FatalfAt(fn.Pos(), "missed typecheck: %v", fn)
+	}
+	if clo.Type() == nil || name.Type() == nil {
+		base.FatalfAt(fn.Pos(), "missing types: %v", fn)
+	}
+	if !types.Identical(clo.Type(), name.Type()) {
+		base.FatalfAt(fn.Pos(), "mismatched types: %v", fn)
+	}
+
+	if base.Flag.W > 1 {
+		s := fmt.Sprintf("new closure func: %v", fn)
+		Dump(s, fn)
+	}
+
+	if pkg != nil {
+		pkg.Decls = append(pkg.Decls, fn)
+	}
+
+	if false && IsTrivialClosure(clo) {
+		// TODO(mdempsky): Investigate if we can/should optimize this
+		// case. walkClosure already handles it later, but it could be
+		// useful to recognize earlier (e.g., it might allow multiple
+		// inlined calls to a function to share a common trivial closure
+		// func, rather than cloning it for each inlined call).
+	}
+
+	return clo
+}
diff --git a/src/cmd/compile/internal/ir/name.go b/src/cmd/compile/internal/ir/name.go
index b6c68bc5e01..a2eec05013e 100644
--- a/src/cmd/compile/internal/ir/name.go
+++ b/src/cmd/compile/internal/ir/name.go
@@ -358,39 +358,74 @@ func (n *Name) Byval() bool {
 	return n.Canonical().flags&nameByval != 0
 }
 
+// NewClosureVar returns a new closure variable for fn to refer to
+// outer variable n.
+func NewClosureVar(pos src.XPos, fn *Func, n *Name) *Name {
+	c := NewNameAt(pos, n.Sym())
+	c.Curfn = fn
+	c.Class = PAUTOHEAP
+	c.SetIsClosureVar(true)
+	c.Defn = n.Canonical()
+	c.Outer = n
+
+	c.SetType(n.Type())
+	c.SetTypecheck(n.Typecheck())
+
+	fn.ClosureVars = append(fn.ClosureVars, c)
+
+	return c
+}
+
+// NewHiddenParam returns a new hidden parameter for fn with the given
+// name and type.
+func NewHiddenParam(pos src.XPos, fn *Func, sym *types.Sym, typ *types.Type) *Name {
+	if fn.OClosure != nil {
+		base.FatalfAt(fn.Pos(), "cannot add hidden parameters to closures")
+	}
+
+	fn.SetNeedctxt(true)
+
+	// Create a fake parameter, disassociated from any real function, to
+	// pretend to capture.
+	fake := NewNameAt(pos, sym)
+	fake.Class = PPARAM
+	fake.SetType(typ)
+	fake.SetByval(true)
+
+	return NewClosureVar(pos, fn, fake)
+}
+
 // CaptureName returns a Name suitable for referring to n from within function
 // fn or from the package block if fn is nil. If n is a free variable declared
-// within a function that encloses fn, then CaptureName returns a closure
-// variable that refers to n and adds it to fn.ClosureVars. Otherwise, it simply
-// returns n.
+// within a function that encloses fn, then CaptureName returns the closure
+// variable that refers to n within fn, creating it if necessary.
+// Otherwise, it simply returns n.
 func CaptureName(pos src.XPos, fn *Func, n *Name) *Name {
+	if n.Op() != ONAME || n.Curfn == nil {
+		return n // okay to use directly
+	}
 	if n.IsClosureVar() {
 		base.FatalfAt(pos, "misuse of CaptureName on closure variable: %v", n)
 	}
-	if n.Op() != ONAME || n.Curfn == nil || n.Curfn == fn {
-		return n // okay to use directly
+
+	c := n.Innermost
+	if c == nil {
+		c = n
 	}
+	if c.Curfn == fn {
+		return c
+	}
+
 	if fn == nil {
 		base.FatalfAt(pos, "package-block reference to %v, declared in %v", n, n.Curfn)
 	}
 
-	c := n.Innermost
-	if c != nil && c.Curfn == fn {
-		return c
-	}
-
 	// Do not have a closure var for the active closure yet; make one.
-	c = NewNameAt(pos, n.Sym())
-	c.Curfn = fn
-	c.Class = PAUTOHEAP
-	c.SetIsClosureVar(true)
-	c.Defn = n
+	c = NewClosureVar(pos, fn, c)
 
 	// Link into list of active closure variables.
 	// Popped from list in FinishCaptureNames.
-	c.Outer = n.Innermost
 	n.Innermost = c
-	fn.ClosureVars = append(fn.ClosureVars, c)
 
 	return c
 }
diff --git a/src/cmd/compile/internal/ir/node.go b/src/cmd/compile/internal/ir/node.go
index af559cc0820..f071cb78ce5 100644
--- a/src/cmd/compile/internal/ir/node.go
+++ b/src/cmd/compile/internal/ir/node.go
@@ -159,7 +159,6 @@ const (
 	OCALLFUNC  // X(Args) (function call f(args))
 	OCALLMETH  // X(Args) (direct method call x.Method(args))
 	OCALLINTER // X(Args) (interface method call x.Method(args))
-	OCALLPART  // X.Sel (method expression x.Method, not called)
 	OCAP       // cap(X)
 	OCLOSE     // close(X)
 	OCLOSURE   // func Type { Func.Closure.Body } (func literal)
@@ -171,6 +170,7 @@ const (
 	OPTRLIT    // &X (X is composite literal)
 	OCONV      // Type(X) (type conversion)
 	OCONVIFACE // Type(X) (type conversion, to interface)
+	OCONVIDATA // Builds a data word to store X in an interface. Equivalent to IDATA(CONVIFACE(X)). Is an ir.ConvExpr.
 	OCONVNOP   // Type(X) (type conversion, no effect)
 	OCOPY      // copy(X, Y)
 	ODCL       // var X (declares X of type X.Type)
@@ -237,6 +237,7 @@ const (
 	OSLICE3ARR   // X[Low : High : Max] (X is pointer to array)
 	OSLICEHEADER // sliceheader{Ptr, Len, Cap} (Ptr is unsafe.Pointer, Len is length, Cap is capacity)
 	ORECOVER     // recover()
+	ORECOVERFP   // recover(Args) w/ explicit FP argument
 	ORECV        // <-X
 	ORUNESTR     // Type(X) (Type is string, X is rune)
 	OSELRECV2    // like OAS2: Lhs = Rhs where len(Lhs)=2, len(Rhs)=1, Rhs[0].Op = ORECV (appears as .Var of OCASE)
@@ -249,14 +250,16 @@ const (
 	OSIZEOF      // unsafe.Sizeof(X)
 	OUNSAFEADD   // unsafe.Add(X, Y)
 	OUNSAFESLICE // unsafe.Slice(X, Y)
-	OMETHEXPR    // method expression
+	OMETHEXPR    // X(Args) (method expression T.Method(args), first argument is the method receiver)
+	OMETHVALUE   // X.Sel   (method expression t.Method, not called)
 
 	// statements
 	OBLOCK // { List } (block of code)
 	OBREAK // break [Label]
 	// OCASE:  case List: Body (List==nil means default)
 	//   For OTYPESW, List is a OTYPE node for the specified type (or OLITERAL
-	//   for nil), and, if a type-switch variable is specified, Rlist is an
+	//   for nil) or an ODYNAMICTYPE indicating a runtime type for generics.
+	//   If a type-switch variable is specified, Var is an
 	//   ONAME for the version of the type-switch variable with the specified
 	//   type.
 	OCASE
@@ -317,9 +320,16 @@ const (
 	OINLMARK       // start of an inlined body, with file/line of caller. Xoffset is an index into the inline tree.
 	OLINKSYMOFFSET // offset within a name
 
+	// opcodes for generics
+	ODYNAMICDOTTYPE  // x = i.(T) where T is a type parameter (or derived from a type parameter)
+	ODYNAMICDOTTYPE2 // x, ok = i.(T) where T is a type parameter (or derived from a type parameter)
+	ODYNAMICTYPE     // a type node for type switches (represents a dynamic target type for a type switch)
+
 	// arch-specific opcodes
-	OTAILCALL // tail call to another function
-	OGETG     // runtime.getg() (read g pointer)
+	OTAILCALL    // tail call to another function
+	OGETG        // runtime.getg() (read g pointer)
+	OGETCALLERPC // runtime.getcallerpc() (continuation PC in caller frame)
+	OGETCALLERSP // runtime.getcallersp() (stack pointer in caller frame)
 
 	OEND
 )
@@ -436,18 +446,19 @@ func (s NameSet) Sorted(less func(*Name, *Name) bool) []*Name {
 	return res
 }
 
-type PragmaFlag int16
+type PragmaFlag uint16
 
 const (
 	// Func pragmas.
-	Nointerface    PragmaFlag = 1 << iota
-	Noescape                  // func parameters don't escape
-	Norace                    // func must not have race detector annotations
-	Nosplit                   // func should not execute on separate stack
-	Noinline                  // func should not be inlined
-	NoCheckPtr                // func should not be instrumented by checkptr
-	CgoUnsafeArgs             // treat a pointer to one arg as a pointer to them all
-	UintptrEscapes            // pointers converted to uintptr escape
+	Nointerface      PragmaFlag = 1 << iota
+	Noescape                    // func parameters don't escape
+	Norace                      // func must not have race detector annotations
+	Nosplit                     // func should not execute on separate stack
+	Noinline                    // func should not be inlined
+	NoCheckPtr                  // func should not be instrumented by checkptr
+	CgoUnsafeArgs               // treat a pointer to one arg as a pointer to them all
+	UintptrKeepAlive            // pointers converted to uintptr must be kept alive (compiler internal only)
+	UintptrEscapes              // pointers converted to uintptr escape
 
 	// Runtime-only func pragmas.
 	// See ../../../../runtime/README.md for detailed descriptions.
@@ -563,7 +574,7 @@ func OuterValue(n Node) Node {
 	for {
 		switch nn := n; nn.Op() {
 		case OXDOT:
-			base.Fatalf("OXDOT in walk")
+			base.FatalfAt(n.Pos(), "OXDOT in walk: %v", n)
 		case ODOT:
 			nn := nn.(*SelectorExpr)
 			n = nn.X
diff --git a/src/cmd/compile/internal/ir/node_gen.go b/src/cmd/compile/internal/ir/node_gen.go
index 22855d7163f..aa41c03beb9 100644
--- a/src/cmd/compile/internal/ir/node_gen.go
+++ b/src/cmd/compile/internal/ir/node_gen.go
@@ -463,6 +463,62 @@ func (n *Decl) editChildren(edit func(Node) Node) {
 	}
 }
 
+func (n *DynamicType) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
+func (n *DynamicType) copy() Node {
+	c := *n
+	c.init = copyNodes(c.init)
+	return &c
+}
+func (n *DynamicType) doChildren(do func(Node) bool) bool {
+	if doNodes(n.init, do) {
+		return true
+	}
+	if n.X != nil && do(n.X) {
+		return true
+	}
+	if n.ITab != nil && do(n.ITab) {
+		return true
+	}
+	return false
+}
+func (n *DynamicType) editChildren(edit func(Node) Node) {
+	editNodes(n.init, edit)
+	if n.X != nil {
+		n.X = edit(n.X).(Node)
+	}
+	if n.ITab != nil {
+		n.ITab = edit(n.ITab).(Node)
+	}
+}
+
+func (n *DynamicTypeAssertExpr) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
+func (n *DynamicTypeAssertExpr) copy() Node {
+	c := *n
+	c.init = copyNodes(c.init)
+	return &c
+}
+func (n *DynamicTypeAssertExpr) doChildren(do func(Node) bool) bool {
+	if doNodes(n.init, do) {
+		return true
+	}
+	if n.X != nil && do(n.X) {
+		return true
+	}
+	if n.T != nil && do(n.T) {
+		return true
+	}
+	return false
+}
+func (n *DynamicTypeAssertExpr) editChildren(edit func(Node) Node) {
+	editNodes(n.init, edit)
+	if n.X != nil {
+		n.X = edit(n.X).(Node)
+	}
+	if n.T != nil {
+		n.T = edit(n.T).(Node)
+	}
+}
+
 func (n *ForStmt) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
 func (n *ForStmt) copy() Node {
 	c := *n
@@ -947,6 +1003,22 @@ func (n *RangeStmt) editChildren(edit func(Node) Node) {
 	}
 }
 
+func (n *RawOrigExpr) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
+func (n *RawOrigExpr) copy() Node {
+	c := *n
+	c.init = copyNodes(c.init)
+	return &c
+}
+func (n *RawOrigExpr) doChildren(do func(Node) bool) bool {
+	if doNodes(n.init, do) {
+		return true
+	}
+	return false
+}
+func (n *RawOrigExpr) editChildren(edit func(Node) Node) {
+	editNodes(n.init, edit)
+}
+
 func (n *ResultExpr) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
 func (n *ResultExpr) copy() Node {
 	c := *n
diff --git a/src/cmd/compile/internal/ir/op_string.go b/src/cmd/compile/internal/ir/op_string.go
index 405a0c6b3c9..b8cee718182 100644
--- a/src/cmd/compile/internal/ir/op_string.go
+++ b/src/cmd/compile/internal/ir/op_string.go
@@ -41,18 +41,18 @@ func _() {
 	_ = x[OCALLFUNC-30]
 	_ = x[OCALLMETH-31]
 	_ = x[OCALLINTER-32]
-	_ = x[OCALLPART-33]
-	_ = x[OCAP-34]
-	_ = x[OCLOSE-35]
-	_ = x[OCLOSURE-36]
-	_ = x[OCOMPLIT-37]
-	_ = x[OMAPLIT-38]
-	_ = x[OSTRUCTLIT-39]
-	_ = x[OARRAYLIT-40]
-	_ = x[OSLICELIT-41]
-	_ = x[OPTRLIT-42]
-	_ = x[OCONV-43]
-	_ = x[OCONVIFACE-44]
+	_ = x[OCAP-33]
+	_ = x[OCLOSE-34]
+	_ = x[OCLOSURE-35]
+	_ = x[OCOMPLIT-36]
+	_ = x[OMAPLIT-37]
+	_ = x[OSTRUCTLIT-38]
+	_ = x[OARRAYLIT-39]
+	_ = x[OSLICELIT-40]
+	_ = x[OPTRLIT-41]
+	_ = x[OCONV-42]
+	_ = x[OCONVIFACE-43]
+	_ = x[OCONVIDATA-44]
 	_ = x[OCONVNOP-45]
 	_ = x[OCOPY-46]
 	_ = x[ODCL-47]
@@ -109,65 +109,72 @@ func _() {
 	_ = x[OSLICE3ARR-98]
 	_ = x[OSLICEHEADER-99]
 	_ = x[ORECOVER-100]
-	_ = x[ORECV-101]
-	_ = x[ORUNESTR-102]
-	_ = x[OSELRECV2-103]
-	_ = x[OIOTA-104]
-	_ = x[OREAL-105]
-	_ = x[OIMAG-106]
-	_ = x[OCOMPLEX-107]
-	_ = x[OALIGNOF-108]
-	_ = x[OOFFSETOF-109]
-	_ = x[OSIZEOF-110]
-	_ = x[OUNSAFEADD-111]
-	_ = x[OUNSAFESLICE-112]
-	_ = x[OMETHEXPR-113]
-	_ = x[OBLOCK-114]
-	_ = x[OBREAK-115]
-	_ = x[OCASE-116]
-	_ = x[OCONTINUE-117]
-	_ = x[ODEFER-118]
-	_ = x[OFALL-119]
-	_ = x[OFOR-120]
-	_ = x[OFORUNTIL-121]
-	_ = x[OGOTO-122]
-	_ = x[OIF-123]
-	_ = x[OLABEL-124]
-	_ = x[OGO-125]
-	_ = x[ORANGE-126]
-	_ = x[ORETURN-127]
-	_ = x[OSELECT-128]
-	_ = x[OSWITCH-129]
-	_ = x[OTYPESW-130]
-	_ = x[OFUNCINST-131]
-	_ = x[OTCHAN-132]
-	_ = x[OTMAP-133]
-	_ = x[OTSTRUCT-134]
-	_ = x[OTINTER-135]
-	_ = x[OTFUNC-136]
-	_ = x[OTARRAY-137]
-	_ = x[OTSLICE-138]
-	_ = x[OINLCALL-139]
-	_ = x[OEFACE-140]
-	_ = x[OITAB-141]
-	_ = x[OIDATA-142]
-	_ = x[OSPTR-143]
-	_ = x[OCFUNC-144]
-	_ = x[OCHECKNIL-145]
-	_ = x[OVARDEF-146]
-	_ = x[OVARKILL-147]
-	_ = x[OVARLIVE-148]
-	_ = x[ORESULT-149]
-	_ = x[OINLMARK-150]
-	_ = x[OLINKSYMOFFSET-151]
-	_ = x[OTAILCALL-152]
-	_ = x[OGETG-153]
-	_ = x[OEND-154]
+	_ = x[ORECOVERFP-101]
+	_ = x[ORECV-102]
+	_ = x[ORUNESTR-103]
+	_ = x[OSELRECV2-104]
+	_ = x[OIOTA-105]
+	_ = x[OREAL-106]
+	_ = x[OIMAG-107]
+	_ = x[OCOMPLEX-108]
+	_ = x[OALIGNOF-109]
+	_ = x[OOFFSETOF-110]
+	_ = x[OSIZEOF-111]
+	_ = x[OUNSAFEADD-112]
+	_ = x[OUNSAFESLICE-113]
+	_ = x[OMETHEXPR-114]
+	_ = x[OMETHVALUE-115]
+	_ = x[OBLOCK-116]
+	_ = x[OBREAK-117]
+	_ = x[OCASE-118]
+	_ = x[OCONTINUE-119]
+	_ = x[ODEFER-120]
+	_ = x[OFALL-121]
+	_ = x[OFOR-122]
+	_ = x[OFORUNTIL-123]
+	_ = x[OGOTO-124]
+	_ = x[OIF-125]
+	_ = x[OLABEL-126]
+	_ = x[OGO-127]
+	_ = x[ORANGE-128]
+	_ = x[ORETURN-129]
+	_ = x[OSELECT-130]
+	_ = x[OSWITCH-131]
+	_ = x[OTYPESW-132]
+	_ = x[OFUNCINST-133]
+	_ = x[OTCHAN-134]
+	_ = x[OTMAP-135]
+	_ = x[OTSTRUCT-136]
+	_ = x[OTINTER-137]
+	_ = x[OTFUNC-138]
+	_ = x[OTARRAY-139]
+	_ = x[OTSLICE-140]
+	_ = x[OINLCALL-141]
+	_ = x[OEFACE-142]
+	_ = x[OITAB-143]
+	_ = x[OIDATA-144]
+	_ = x[OSPTR-145]
+	_ = x[OCFUNC-146]
+	_ = x[OCHECKNIL-147]
+	_ = x[OVARDEF-148]
+	_ = x[OVARKILL-149]
+	_ = x[OVARLIVE-150]
+	_ = x[ORESULT-151]
+	_ = x[OINLMARK-152]
+	_ = x[OLINKSYMOFFSET-153]
+	_ = x[ODYNAMICDOTTYPE-154]
+	_ = x[ODYNAMICDOTTYPE2-155]
+	_ = x[ODYNAMICTYPE-156]
+	_ = x[OTAILCALL-157]
+	_ = x[OGETG-158]
+	_ = x[OGETCALLERPC-159]
+	_ = x[OGETCALLERSP-160]
+	_ = x[OEND-161]
 }
 
-const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
+const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
 
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 213, 216, 221, 228, 235, 241, 250, 258, 266, 272, 276, 285, 292, 296, 299, 306, 314, 321, 327, 330, 336, 343, 351, 355, 362, 370, 372, 374, 376, 378, 380, 382, 387, 392, 400, 403, 412, 415, 419, 427, 434, 443, 456, 459, 462, 465, 468, 471, 474, 480, 483, 486, 492, 496, 499, 503, 508, 513, 519, 524, 528, 533, 541, 549, 555, 564, 575, 582, 586, 593, 601, 605, 609, 613, 620, 627, 635, 641, 650, 661, 669, 674, 679, 683, 691, 696, 700, 703, 711, 715, 717, 722, 724, 729, 735, 741, 747, 753, 761, 766, 770, 777, 783, 788, 794, 800, 807, 812, 816, 821, 825, 830, 838, 844, 851, 858, 864, 871, 884, 892, 896, 899}
+var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 208, 213, 220, 227, 233, 242, 250, 258, 264, 268, 277, 286, 293, 297, 300, 307, 315, 322, 328, 331, 337, 344, 352, 356, 363, 371, 373, 375, 377, 379, 381, 383, 388, 393, 401, 404, 413, 416, 420, 428, 435, 444, 457, 460, 463, 466, 469, 472, 475, 481, 484, 487, 493, 497, 500, 504, 509, 514, 520, 525, 529, 534, 542, 550, 556, 565, 576, 583, 592, 596, 603, 611, 615, 619, 623, 630, 637, 645, 651, 660, 671, 679, 688, 693, 698, 702, 710, 715, 719, 722, 730, 734, 736, 741, 743, 748, 754, 760, 766, 772, 780, 785, 789, 796, 802, 807, 813, 819, 826, 831, 835, 840, 844, 849, 857, 863, 870, 877, 883, 890, 903, 917, 932, 943, 951, 955, 966, 977, 980}
 
 func (i Op) String() string {
 	if i >= Op(len(_Op_index)-1) {
diff --git a/src/cmd/compile/internal/ir/package.go b/src/cmd/compile/internal/ir/package.go
index e4b93d113ed..3896e2b91b1 100644
--- a/src/cmd/compile/internal/ir/package.go
+++ b/src/cmd/compile/internal/ir/package.go
@@ -32,7 +32,4 @@ type Package struct {
 
 	// Exported (or re-exported) symbols.
 	Exports []*Name
-
-	// Map from function names of stencils to already-created stencils.
-	Stencils map[*types.Sym]*Func
 }
diff --git a/src/cmd/compile/internal/ir/scc.go b/src/cmd/compile/internal/ir/scc.go
index 83c6074170b..2cfceaa1f62 100644
--- a/src/cmd/compile/internal/ir/scc.go
+++ b/src/cmd/compile/internal/ir/scc.go
@@ -90,7 +90,7 @@ func (v *bottomUpVisitor) visit(n *Func) uint32 {
 			if n := n.(*Name); n.Class == PFUNC {
 				do(n.Defn)
 			}
-		case ODOTMETH, OCALLPART, OMETHEXPR:
+		case ODOTMETH, OMETHVALUE, OMETHEXPR:
 			if fn := MethodExprName(n); fn != nil {
 				do(fn.Defn)
 			}
diff --git a/src/cmd/compile/internal/ir/type.go b/src/cmd/compile/internal/ir/type.go
index a903ea8cd45..63dd673dcdf 100644
--- a/src/cmd/compile/internal/ir/type.go
+++ b/src/cmd/compile/internal/ir/type.go
@@ -300,11 +300,36 @@ func (n *typeNode) CanBeNtype()       {}
 
 // TypeNode returns the Node representing the type t.
 func TypeNode(t *types.Type) Ntype {
+	return TypeNodeAt(src.NoXPos, t)
+}
+
+// TypeNodeAt is like TypeNode, but allows specifying the position
+// information if a new OTYPE needs to be constructed.
+//
+// Deprecated: Use TypeNode instead. For typical use, the position for
+// an anonymous OTYPE node should not matter. However, TypeNodeAt is
+// available for use with toolstash -cmp to refactor existing code
+// that is sensitive to OTYPE position.
+func TypeNodeAt(pos src.XPos, t *types.Type) Ntype {
 	if n := t.Obj(); n != nil {
 		if n.Type() != t {
 			base.Fatalf("type skew: %v has type %v, but expected %v", n, n.Type(), t)
 		}
 		return n.(Ntype)
 	}
-	return newTypeNode(src.NoXPos, t)
+	return newTypeNode(pos, t)
+}
+
+// A DynamicType represents the target type in a type switch.
+type DynamicType struct {
+	miniExpr
+	X    Node // a *runtime._type for the targeted type
+	ITab Node // for type switches from nonempty interfaces to non-interfaces, this is the itab for that pair.
+}
+
+func NewDynamicType(pos src.XPos, x Node) *DynamicType {
+	n := &DynamicType{X: x}
+	n.pos = pos
+	n.op = ODYNAMICTYPE
+	return n
 }
diff --git a/src/cmd/compile/internal/ir/val.go b/src/cmd/compile/internal/ir/val.go
index 03c320e205d..bfe7d2bb436 100644
--- a/src/cmd/compile/internal/ir/val.go
+++ b/src/cmd/compile/internal/ir/val.go
@@ -66,7 +66,7 @@ func Float64Val(v constant.Value) float64 {
 
 func AssertValidTypeForConst(t *types.Type, v constant.Value) {
 	if !ValidTypeForConst(t, v) {
-		base.Fatalf("%v does not represent %v", t, v)
+		base.Fatalf("%v (%v) does not represent %v (%v)", t, t.Kind(), v, v.Kind())
 	}
 }
 
diff --git a/src/cmd/compile/internal/liveness/plive.go b/src/cmd/compile/internal/liveness/plive.go
index f5c2ef7709e..2705eac4f7b 100644
--- a/src/cmd/compile/internal/liveness/plive.go
+++ b/src/cmd/compile/internal/liveness/plive.go
@@ -1082,6 +1082,10 @@ func (lv *liveness) showlive(v *ssa.Value, live bitvec.BitVec) {
 	if base.Flag.Live == 0 || ir.FuncName(lv.fn) == "init" || strings.HasPrefix(ir.FuncName(lv.fn), ".") {
 		return
 	}
+	if lv.fn.Wrapper() || lv.fn.Dupok() {
+		// Skip reporting liveness information for compiler-generated wrappers.
+		return
+	}
 	if !(v == nil || v.Op.IsCall()) {
 		// Historically we only printed this information at
 		// calls. Keep doing so.
diff --git a/src/cmd/compile/internal/logopt/logopt_test.go b/src/cmd/compile/internal/logopt/logopt_test.go
index 71976174b03..902cbc8091f 100644
--- a/src/cmd/compile/internal/logopt/logopt_test.go
+++ b/src/cmd/compile/internal/logopt/logopt_test.go
@@ -209,7 +209,7 @@ func s15a8(x *[15]int64) [15]int64 {
 		want(t, slogged, `{"range":{"start":{"line":11,"character":6},"end":{"line":11,"character":6}},"severity":3,"code":"isInBounds","source":"go compiler","message":""}`)
 		want(t, slogged, `{"range":{"start":{"line":7,"character":6},"end":{"line":7,"character":6}},"severity":3,"code":"canInlineFunction","source":"go compiler","message":"cost: 35"}`)
 		// escape analysis explanation
-		want(t, slogged, `{"range":{"start":{"line":7,"character":13},"end":{"line":7,"character":13}},"severity":3,"code":"leak","source":"go compiler","message":"parameter z leaks to ~r2 with derefs=0",`+
+		want(t, slogged, `{"range":{"start":{"line":7,"character":13},"end":{"line":7,"character":13}},"severity":3,"code":"leak","source":"go compiler","message":"parameter z leaks to ~r0 with derefs=0",`+
 			`"relatedInformation":[`+
 			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":13},"end":{"line":9,"character":13}}},"message":"escflow:    flow: y = z:"},`+
 			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":13},"end":{"line":9,"character":13}}},"message":"escflow:      from y := z (assign-pair)"},`+
@@ -220,8 +220,8 @@ func s15a8(x *[15]int64) [15]int64 {
 			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":13},"end":{"line":9,"character":13}}},"message":"escflow:      from \u0026y.b (address-of)"},`+
 			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":4,"character":9},"end":{"line":4,"character":9}}},"message":"inlineLoc"},`+
 			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":13},"end":{"line":9,"character":13}}},"message":"escflow:      from ~R0 = \u0026y.b (assign-pair)"},`+
-			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":3},"end":{"line":9,"character":3}}},"message":"escflow:    flow: ~r2 = ~R0:"},`+
-			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":3},"end":{"line":9,"character":3}}},"message":"escflow:      from return (*int)(~R0) (return)"}]}`)
+			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":3},"end":{"line":9,"character":3}}},"message":"escflow:    flow: ~r0 = ~R0:"},`+
+			`{"location":{"uri":"file://tmpdir/file.go","range":{"start":{"line":9,"character":3},"end":{"line":9,"character":3}}},"message":"escflow:      from return ~R0 (return)"}]}`)
 	})
 }
 
diff --git a/src/cmd/compile/internal/mips/galign.go b/src/cmd/compile/internal/mips/galign.go
index f892923ba03..4e6897042ec 100644
--- a/src/cmd/compile/internal/mips/galign.go
+++ b/src/cmd/compile/internal/mips/galign.go
@@ -21,7 +21,6 @@ func Init(arch *ssagen.ArchInfo) {
 	arch.SoftFloat = (buildcfg.GOMIPS == "softfloat")
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 	arch.SSAMarkMoves = func(s *ssagen.State, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue
 	arch.SSAGenBlock = ssaGenBlock
diff --git a/src/cmd/compile/internal/mips64/galign.go b/src/cmd/compile/internal/mips64/galign.go
index af81366e51b..412bc71aab2 100644
--- a/src/cmd/compile/internal/mips64/galign.go
+++ b/src/cmd/compile/internal/mips64/galign.go
@@ -21,7 +21,6 @@ func Init(arch *ssagen.ArchInfo) {
 	arch.SoftFloat = buildcfg.GOMIPS64 == "softfloat"
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *ssagen.State, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue
diff --git a/src/cmd/compile/internal/noder/codes.go b/src/cmd/compile/internal/noder/codes.go
new file mode 100644
index 00000000000..f8cb7729acc
--- /dev/null
+++ b/src/cmd/compile/internal/noder/codes.go
@@ -0,0 +1,124 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+type code interface {
+	marker() syncMarker
+	value() int
+}
+
+type codeVal int
+
+func (c codeVal) marker() syncMarker { return syncVal }
+func (c codeVal) value() int         { return int(c) }
+
+const (
+	valBool codeVal = iota
+	valString
+	valInt64
+	valBigInt
+	valBigRat
+	valBigFloat
+)
+
+type codeType int
+
+func (c codeType) marker() syncMarker { return syncType }
+func (c codeType) value() int         { return int(c) }
+
+const (
+	typeBasic codeType = iota
+	typeNamed
+	typePointer
+	typeSlice
+	typeArray
+	typeChan
+	typeMap
+	typeSignature
+	typeStruct
+	typeInterface
+	typeUnion
+	typeTypeParam
+)
+
+type codeObj int
+
+func (c codeObj) marker() syncMarker { return syncCodeObj }
+func (c codeObj) value() int         { return int(c) }
+
+const (
+	objAlias codeObj = iota
+	objConst
+	objType
+	objFunc
+	objVar
+	objStub
+)
+
+type codeStmt int
+
+func (c codeStmt) marker() syncMarker { return syncStmt1 }
+func (c codeStmt) value() int         { return int(c) }
+
+const (
+	stmtEnd codeStmt = iota
+	stmtLabel
+	stmtBlock
+	stmtExpr
+	stmtSend
+	stmtAssign
+	stmtAssignOp
+	stmtIncDec
+	stmtBranch
+	stmtCall
+	stmtReturn
+	stmtIf
+	stmtFor
+	stmtSwitch
+	stmtSelect
+
+	// TODO(mdempsky): Remove after we don't care about toolstash -cmp.
+	stmtTypeDeclHack
+)
+
+type codeExpr int
+
+func (c codeExpr) marker() syncMarker { return syncExpr }
+func (c codeExpr) value() int         { return int(c) }
+
+// TODO(mdempsky): Split expr into addr, for lvalues.
+const (
+	exprNone codeExpr = iota
+	exprConst
+	exprType  // type expression
+	exprLocal // local variable
+	exprName  // global variable or function
+	exprBlank
+	exprCompLit
+	exprFuncLit
+	exprSelector
+	exprIndex
+	exprSlice
+	exprAssert
+	exprUnaryOp
+	exprBinaryOp
+	exprCall
+	exprConvert
+)
+
+type codeDecl int
+
+func (c codeDecl) marker() syncMarker { return syncDecl }
+func (c codeDecl) value() int         { return int(c) }
+
+const (
+	declEnd codeDecl = iota
+	declFunc
+	declMethod
+	declVar
+	declOther
+)
diff --git a/src/cmd/compile/internal/noder/decl.go b/src/cmd/compile/internal/noder/decl.go
index 4ca2eb4740a..429c8a14c8a 100644
--- a/src/cmd/compile/internal/noder/decl.go
+++ b/src/cmd/compile/internal/noder/decl.go
@@ -41,20 +41,27 @@ func (g *irgen) decls(decls []syntax.Decl) []ir.Node {
 }
 
 func (g *irgen) importDecl(p *noder, decl *syntax.ImportDecl) {
-	// TODO(mdempsky): Merge with gcimports so we don't have to import
-	// packages twice.
-
 	g.pragmaFlags(decl.Pragma, 0)
 
-	ipkg := importfile(decl)
-	if ipkg == ir.Pkgs.Unsafe {
+	// Get the imported package's path, as resolved already by types2
+	// and gcimporter. This is the same path as would be computed by
+	// parseImportPath.
+	switch pkgNameOf(g.info, decl).Imported().Path() {
+	case "unsafe":
 		p.importedUnsafe = true
-	}
-	if ipkg.Path == "embed" {
+	case "embed":
 		p.importedEmbed = true
 	}
 }
 
+// pkgNameOf returns the PkgName associated with the given ImportDecl.
+func pkgNameOf(info *types2.Info, decl *syntax.ImportDecl) *types2.PkgName {
+	if name := decl.LocalPkgName; name != nil {
+		return info.Defs[name].(*types2.PkgName)
+	}
+	return info.Implicits[decl].(*types2.PkgName)
+}
+
 func (g *irgen) constDecl(out *ir.Nodes, decl *syntax.ConstDecl) {
 	g.pragmaFlags(decl.Pragma, 0)
 
@@ -95,7 +102,21 @@ func (g *irgen) funcDecl(out *ir.Nodes, decl *syntax.FuncDecl) {
 		g.target.Inits = append(g.target.Inits, fn)
 	}
 
+	if fn.Type().HasTParam() {
+		g.topFuncIsGeneric = true
+	}
 	g.funcBody(fn, decl.Recv, decl.Type, decl.Body)
+	g.topFuncIsGeneric = false
+	if fn.Type().HasTParam() && fn.Body != nil {
+		// Set pointers to the dcls/body of a generic function/method in
+		// the Inl struct, so it is marked for export, is available for
+		// stenciling, and works with Inline_Flood().
+		fn.Inl = &ir.Inline{
+			Cost: 1,
+			Dcl:  fn.Dcl,
+			Body: fn.Body,
+		}
+	}
 
 	out.Append(fn)
 }
@@ -104,13 +125,7 @@ func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
 	if decl.Alias {
 		name, _ := g.def(decl.Name)
 		g.pragmaFlags(decl.Pragma, 0)
-
-		// TODO(mdempsky): This matches how typecheckdef marks aliases for
-		// export, but this won't generalize to exporting function-scoped
-		// type aliases. We should maybe just use n.Alias() instead.
-		if ir.CurFunc == nil {
-			name.Sym().Def = ir.TypeNode(name.Type())
-		}
+		assert(name.Alias()) // should be set by irgen.obj
 
 		out.Append(ir.NewDecl(g.pos(decl), ir.ODCLTYPE, name))
 		return
@@ -154,11 +169,15 @@ func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
 	// [mdempsky: Subtleties like these are why I always vehemently
 	// object to new type pragmas.]
 	ntyp.SetUnderlying(g.typeExpr(decl.Type))
-	if len(decl.TParamList) > 0 {
-		// Set HasTParam if there are any tparams, even if no tparams are
-		// used in the type itself (e.g., if it is an empty struct, or no
-		// fields in the struct use the tparam).
-		ntyp.SetHasTParam(true)
+
+	tparams := otyp.(*types2.Named).TParams()
+	if n := tparams.Len(); n > 0 {
+		rparams := make([]*types.Type, n)
+		for i := range rparams {
+			rparams[i] = g.typ(tparams.At(i).Type())
+		}
+		// This will set hasTParam flag if any rparams are not concrete types.
+		ntyp.SetRParams(rparams)
 	}
 	types.ResumeCheckSize()
 
diff --git a/src/cmd/compile/internal/noder/decoder.go b/src/cmd/compile/internal/noder/decoder.go
new file mode 100644
index 00000000000..3dc61c6a692
--- /dev/null
+++ b/src/cmd/compile/internal/noder/decoder.go
@@ -0,0 +1,301 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"encoding/binary"
+	"fmt"
+	"go/constant"
+	"go/token"
+	"math/big"
+	"os"
+	"runtime"
+	"strings"
+
+	"cmd/compile/internal/base"
+)
+
+type pkgDecoder struct {
+	pkgPath string
+
+	elemEndsEnds [numRelocs]uint32
+	elemEnds     []uint32
+	elemData     string
+}
+
+func newPkgDecoder(pkgPath, input string) pkgDecoder {
+	pr := pkgDecoder{
+		pkgPath: pkgPath,
+	}
+
+	// TODO(mdempsky): Implement direct indexing of input string to
+	// avoid copying the position information.
+
+	r := strings.NewReader(input)
+
+	assert(binary.Read(r, binary.LittleEndian, pr.elemEndsEnds[:]) == nil)
+
+	pr.elemEnds = make([]uint32, pr.elemEndsEnds[len(pr.elemEndsEnds)-1])
+	assert(binary.Read(r, binary.LittleEndian, pr.elemEnds[:]) == nil)
+
+	pos, err := r.Seek(0, os.SEEK_CUR)
+	assert(err == nil)
+
+	pr.elemData = input[pos:]
+	assert(len(pr.elemData) == int(pr.elemEnds[len(pr.elemEnds)-1]))
+
+	return pr
+}
+
+func (pr *pkgDecoder) numElems(k reloc) int {
+	count := int(pr.elemEndsEnds[k])
+	if k > 0 {
+		count -= int(pr.elemEndsEnds[k-1])
+	}
+	return count
+}
+
+func (pr *pkgDecoder) totalElems() int {
+	return len(pr.elemEnds)
+}
+
+func (pr *pkgDecoder) absIdx(k reloc, idx int) int {
+	absIdx := idx
+	if k > 0 {
+		absIdx += int(pr.elemEndsEnds[k-1])
+	}
+	if absIdx >= int(pr.elemEndsEnds[k]) {
+		base.Fatalf("%v:%v is out of bounds; %v", k, idx, pr.elemEndsEnds)
+	}
+	return absIdx
+}
+
+func (pr *pkgDecoder) dataIdx(k reloc, idx int) string {
+	absIdx := pr.absIdx(k, idx)
+
+	var start uint32
+	if absIdx > 0 {
+		start = pr.elemEnds[absIdx-1]
+	}
+	end := pr.elemEnds[absIdx]
+
+	return pr.elemData[start:end]
+}
+
+func (pr *pkgDecoder) stringIdx(idx int) string {
+	return pr.dataIdx(relocString, idx)
+}
+
+func (pr *pkgDecoder) newDecoder(k reloc, idx int, marker syncMarker) decoder {
+	r := pr.newDecoderRaw(k, idx)
+	r.sync(marker)
+	return r
+}
+
+func (pr *pkgDecoder) newDecoderRaw(k reloc, idx int) decoder {
+	r := decoder{
+		common: pr,
+		k:      k,
+		idx:    idx,
+	}
+
+	// TODO(mdempsky) r.data.Reset(...) after #44505 is resolved.
+	r.data = *strings.NewReader(pr.dataIdx(k, idx))
+
+	r.sync(syncRelocs)
+	r.relocs = make([]relocEnt, r.len())
+	for i := range r.relocs {
+		r.sync(syncReloc)
+		r.relocs[i] = relocEnt{reloc(r.len()), r.len()}
+	}
+
+	return r
+}
+
+type decoder struct {
+	common *pkgDecoder
+
+	relocs []relocEnt
+	data   strings.Reader
+
+	k   reloc
+	idx int
+}
+
+func (r *decoder) checkErr(err error) {
+	if err != nil {
+		base.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func (r *decoder) rawUvarint() uint64 {
+	x, err := binary.ReadUvarint(&r.data)
+	r.checkErr(err)
+	return x
+}
+
+func (r *decoder) rawVarint() int64 {
+	ux := r.rawUvarint()
+
+	// Zig-zag decode.
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x
+}
+
+func (r *decoder) rawReloc(k reloc, idx int) int {
+	e := r.relocs[idx]
+	assert(e.kind == k)
+	return e.idx
+}
+
+func (r *decoder) sync(mWant syncMarker) {
+	if !enableSync {
+		return
+	}
+
+	pos, _ := r.data.Seek(0, os.SEEK_CUR) // TODO(mdempsky): io.SeekCurrent after #44505 is resolved
+	mHave := syncMarker(r.rawUvarint())
+	writerPCs := make([]int, r.rawUvarint())
+	for i := range writerPCs {
+		writerPCs[i] = int(r.rawUvarint())
+	}
+
+	if mHave == mWant {
+		return
+	}
+
+	// There's some tension here between printing:
+	//
+	// (1) full file paths that tools can recognize (e.g., so emacs
+	//     hyperlinks the "file:line" text for easy navigation), or
+	//
+	// (2) short file paths that are easier for humans to read (e.g., by
+	//     omitting redundant or irrelevant details, so it's easier to
+	//     focus on the useful bits that remain).
+	//
+	// The current formatting favors the former, as it seems more
+	// helpful in practice. But perhaps the formatting could be improved
+	// to better address both concerns. For example, use relative file
+	// paths if they would be shorter, or rewrite file paths to contain
+	// "$GOROOT" (like objabi.AbsFile does) if tools can be taught how
+	// to reliably expand that again.
+
+	fmt.Printf("export data desync: package %q, section %v, index %v, offset %v\n", r.common.pkgPath, r.k, r.idx, pos)
+
+	fmt.Printf("\nfound %v, written at:\n", mHave)
+	if len(writerPCs) == 0 {
+		fmt.Printf("\t[stack trace unavailable; recompile package %q with -d=syncframes]\n", r.common.pkgPath)
+	}
+	for _, pc := range writerPCs {
+		fmt.Printf("\t%s\n", r.common.stringIdx(r.rawReloc(relocString, pc)))
+	}
+
+	fmt.Printf("\nexpected %v, reading at:\n", mWant)
+	var readerPCs [32]uintptr // TODO(mdempsky): Dynamically size?
+	n := runtime.Callers(2, readerPCs[:])
+	for _, pc := range fmtFrames(readerPCs[:n]...) {
+		fmt.Printf("\t%s\n", pc)
+	}
+
+	// We already printed a stack trace for the reader, so now we can
+	// simply exit. Printing a second one with panic or base.Fatalf
+	// would just be noise.
+	os.Exit(1)
+}
+
+func (r *decoder) bool() bool {
+	r.sync(syncBool)
+	x, err := r.data.ReadByte()
+	r.checkErr(err)
+	assert(x < 2)
+	return x != 0
+}
+
+func (r *decoder) int64() int64 {
+	r.sync(syncInt64)
+	return r.rawVarint()
+}
+
+func (r *decoder) uint64() uint64 {
+	r.sync(syncUint64)
+	return r.rawUvarint()
+}
+
+func (r *decoder) len() int   { x := r.uint64(); v := int(x); assert(uint64(v) == x); return v }
+func (r *decoder) int() int   { x := r.int64(); v := int(x); assert(int64(v) == x); return v }
+func (r *decoder) uint() uint { x := r.uint64(); v := uint(x); assert(uint64(v) == x); return v }
+
+func (r *decoder) code(mark syncMarker) int {
+	r.sync(mark)
+	return r.len()
+}
+
+func (r *decoder) reloc(k reloc) int {
+	r.sync(syncUseReloc)
+	return r.rawReloc(k, r.len())
+}
+
+func (r *decoder) string() string {
+	r.sync(syncString)
+	return r.common.stringIdx(r.reloc(relocString))
+}
+
+func (r *decoder) strings() []string {
+	res := make([]string, r.len())
+	for i := range res {
+		res[i] = r.string()
+	}
+	return res
+}
+
+func (r *decoder) rawValue() constant.Value {
+	isComplex := r.bool()
+	val := r.scalar()
+	if isComplex {
+		val = constant.BinaryOp(val, token.ADD, constant.MakeImag(r.scalar()))
+	}
+	return val
+}
+
+func (r *decoder) scalar() constant.Value {
+	switch tag := codeVal(r.code(syncVal)); tag {
+	default:
+		panic(fmt.Sprintf("unexpected scalar tag: %v", tag))
+
+	case valBool:
+		return constant.MakeBool(r.bool())
+	case valString:
+		return constant.MakeString(r.string())
+	case valInt64:
+		return constant.MakeInt64(r.int64())
+	case valBigInt:
+		return constant.Make(r.bigInt())
+	case valBigRat:
+		num := r.bigInt()
+		denom := r.bigInt()
+		return constant.Make(new(big.Rat).SetFrac(num, denom))
+	case valBigFloat:
+		return constant.Make(r.bigFloat())
+	}
+}
+
+func (r *decoder) bigInt() *big.Int {
+	v := new(big.Int).SetBytes([]byte(r.string()))
+	if r.bool() {
+		v.Neg(v)
+	}
+	return v
+}
+
+func (r *decoder) bigFloat() *big.Float {
+	v := new(big.Float).SetPrec(512)
+	assert(v.UnmarshalText([]byte(r.string())) == nil)
+	return v
+}
diff --git a/src/cmd/compile/internal/noder/encoder.go b/src/cmd/compile/internal/noder/encoder.go
new file mode 100644
index 00000000000..d8ab0f6255d
--- /dev/null
+++ b/src/cmd/compile/internal/noder/encoder.go
@@ -0,0 +1,284 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"go/constant"
+	"io"
+	"math/big"
+	"runtime"
+
+	"cmd/compile/internal/base"
+)
+
+type pkgEncoder struct {
+	elems [numRelocs][]string
+
+	stringsIdx map[string]int
+}
+
+func newPkgEncoder() pkgEncoder {
+	return pkgEncoder{
+		stringsIdx: make(map[string]int),
+	}
+}
+
+func (pw *pkgEncoder) dump(out io.Writer) {
+	writeUint32 := func(x uint32) {
+		assert(binary.Write(out, binary.LittleEndian, x) == nil)
+	}
+
+	var sum uint32
+	for _, elems := range &pw.elems {
+		sum += uint32(len(elems))
+		writeUint32(sum)
+	}
+
+	sum = 0
+	for _, elems := range &pw.elems {
+		for _, elem := range elems {
+			sum += uint32(len(elem))
+			writeUint32(sum)
+		}
+	}
+
+	for _, elems := range &pw.elems {
+		for _, elem := range elems {
+			_, err := io.WriteString(out, elem)
+			assert(err == nil)
+		}
+	}
+}
+
+func (pw *pkgEncoder) stringIdx(s string) int {
+	if idx, ok := pw.stringsIdx[s]; ok {
+		assert(pw.elems[relocString][idx] == s)
+		return idx
+	}
+
+	idx := len(pw.elems[relocString])
+	pw.elems[relocString] = append(pw.elems[relocString], s)
+	pw.stringsIdx[s] = idx
+	return idx
+}
+
+func (pw *pkgEncoder) newEncoder(k reloc, marker syncMarker) encoder {
+	e := pw.newEncoderRaw(k)
+	e.sync(marker)
+	return e
+}
+
+func (pw *pkgEncoder) newEncoderRaw(k reloc) encoder {
+	idx := len(pw.elems[k])
+	pw.elems[k] = append(pw.elems[k], "") // placeholder
+
+	return encoder{
+		p:   pw,
+		k:   k,
+		idx: idx,
+	}
+}
+
+// Encoders
+
+type encoder struct {
+	p *pkgEncoder
+
+	relocs []relocEnt
+	data   bytes.Buffer
+
+	encodingRelocHeader bool
+
+	k   reloc
+	idx int
+}
+
+func (w *encoder) flush() int {
+	var sb bytes.Buffer // TODO(mdempsky): strings.Builder after #44505 is resolved
+
+	// Backup the data so we write the relocations at the front.
+	var tmp bytes.Buffer
+	io.Copy(&tmp, &w.data)
+
+	// TODO(mdempsky): Consider writing these out separately so they're
+	// easier to strip, along with function bodies, so that we can prune
+	// down to just the data that's relevant to go/types.
+	if w.encodingRelocHeader {
+		base.Fatalf("encodingRelocHeader already true; recursive flush?")
+	}
+	w.encodingRelocHeader = true
+	w.sync(syncRelocs)
+	w.len(len(w.relocs))
+	for _, rent := range w.relocs {
+		w.sync(syncReloc)
+		w.len(int(rent.kind))
+		w.len(rent.idx)
+	}
+
+	io.Copy(&sb, &w.data)
+	io.Copy(&sb, &tmp)
+	w.p.elems[w.k][w.idx] = sb.String()
+
+	return w.idx
+}
+
+func (w *encoder) checkErr(err error) {
+	if err != nil {
+		base.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func (w *encoder) rawUvarint(x uint64) {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutUvarint(buf[:], x)
+	_, err := w.data.Write(buf[:n])
+	w.checkErr(err)
+}
+
+func (w *encoder) rawVarint(x int64) {
+	// Zig-zag encode.
+	ux := uint64(x) << 1
+	if x < 0 {
+		ux = ^ux
+	}
+
+	w.rawUvarint(ux)
+}
+
+func (w *encoder) rawReloc(r reloc, idx int) int {
+	// TODO(mdempsky): Use map for lookup.
+	for i, rent := range w.relocs {
+		if rent.kind == r && rent.idx == idx {
+			return i
+		}
+	}
+
+	i := len(w.relocs)
+	w.relocs = append(w.relocs, relocEnt{r, idx})
+	return i
+}
+
+func (w *encoder) sync(m syncMarker) {
+	if !enableSync {
+		return
+	}
+
+	// Writing out stack frame string references requires working
+	// relocations, but writing out the relocations themselves involves
+	// sync markers. To prevent infinite recursion, we simply trim the
+	// stack frame for sync markers within the relocation header.
+	var frames []string
+	if !w.encodingRelocHeader && base.Debug.SyncFrames > 0 {
+		pcs := make([]uintptr, base.Debug.SyncFrames)
+		n := runtime.Callers(2, pcs)
+		frames = fmtFrames(pcs[:n]...)
+	}
+
+	// TODO(mdempsky): Save space by writing out stack frames as a
+	// linked list so we can share common stack frames.
+	w.rawUvarint(uint64(m))
+	w.rawUvarint(uint64(len(frames)))
+	for _, frame := range frames {
+		w.rawUvarint(uint64(w.rawReloc(relocString, w.p.stringIdx(frame))))
+	}
+}
+
+func (w *encoder) bool(b bool) bool {
+	w.sync(syncBool)
+	var x byte
+	if b {
+		x = 1
+	}
+	err := w.data.WriteByte(x)
+	w.checkErr(err)
+	return b
+}
+
+func (w *encoder) int64(x int64) {
+	w.sync(syncInt64)
+	w.rawVarint(x)
+}
+
+func (w *encoder) uint64(x uint64) {
+	w.sync(syncUint64)
+	w.rawUvarint(x)
+}
+
+func (w *encoder) len(x int)   { assert(x >= 0); w.uint64(uint64(x)) }
+func (w *encoder) int(x int)   { w.int64(int64(x)) }
+func (w *encoder) uint(x uint) { w.uint64(uint64(x)) }
+
+func (w *encoder) reloc(r reloc, idx int) {
+	w.sync(syncUseReloc)
+	w.len(w.rawReloc(r, idx))
+}
+
+func (w *encoder) code(c code) {
+	w.sync(c.marker())
+	w.len(c.value())
+}
+
+func (w *encoder) string(s string) {
+	w.sync(syncString)
+	w.reloc(relocString, w.p.stringIdx(s))
+}
+
+func (w *encoder) strings(ss []string) {
+	w.len(len(ss))
+	for _, s := range ss {
+		w.string(s)
+	}
+}
+
+func (w *encoder) rawValue(val constant.Value) {
+	if w.bool(val.Kind() == constant.Complex) {
+		w.scalar(constant.Real(val))
+		w.scalar(constant.Imag(val))
+	} else {
+		w.scalar(val)
+	}
+}
+
+func (w *encoder) scalar(val constant.Value) {
+	switch v := constant.Val(val).(type) {
+	default:
+		panic(fmt.Sprintf("unhandled %v (%v)", val, val.Kind()))
+	case bool:
+		w.code(valBool)
+		w.bool(v)
+	case string:
+		w.code(valString)
+		w.string(v)
+	case int64:
+		w.code(valInt64)
+		w.int64(v)
+	case *big.Int:
+		w.code(valBigInt)
+		w.bigInt(v)
+	case *big.Rat:
+		w.code(valBigRat)
+		w.bigInt(v.Num())
+		w.bigInt(v.Denom())
+	case *big.Float:
+		w.code(valBigFloat)
+		w.bigFloat(v)
+	}
+}
+
+func (w *encoder) bigInt(v *big.Int) {
+	b := v.Bytes()
+	w.string(string(b)) // TODO: More efficient encoding.
+	w.bool(v.Sign() < 0)
+}
+
+func (w *encoder) bigFloat(v *big.Float) {
+	b := v.Append(nil, 'p', -1)
+	w.string(string(b)) // TODO: More efficient encoding.
+}
diff --git a/src/cmd/compile/internal/noder/export.go b/src/cmd/compile/internal/noder/export.go
new file mode 100644
index 00000000000..1a296e22c84
--- /dev/null
+++ b/src/cmd/compile/internal/noder/export.go
@@ -0,0 +1,65 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/typecheck"
+	"cmd/internal/bio"
+)
+
+// writeNewExportFunc is a hook that can be added to append extra
+// export data after the normal export data section. It allows
+// experimenting with new export data format designs without requiring
+// immediate support in the go/internal or x/tools importers.
+var writeNewExportFunc func(out io.Writer)
+
+func WriteExports(out *bio.Writer) {
+	// When unified IR exports are enable, we simply append it to the
+	// end of the normal export data (with compiler extensions
+	// disabled), and write an extra header giving its size.
+	//
+	// If the compiler sees this header, it knows to read the new data
+	// instead; meanwhile the go/types importers will silently ignore it
+	// and continue processing the old export instead.
+	//
+	// This allows us to experiment with changes to the new export data
+	// format without needing to update the go/internal/gcimporter or
+	// (worse) x/tools/go/gcexportdata.
+
+	useNewExport := writeNewExportFunc != nil
+
+	var old, new bytes.Buffer
+
+	typecheck.WriteExports(&old, !useNewExport)
+
+	if useNewExport {
+		writeNewExportFunc(&new)
+	}
+
+	oldLen := old.Len()
+	newLen := new.Len()
+
+	if useNewExport {
+		fmt.Fprintf(out, "\nnewexportsize %v\n", newLen)
+	}
+
+	// The linker also looks for the $$ marker - use char after $$ to distinguish format.
+	out.WriteString("\n$$B\n") // indicate binary export format
+	io.Copy(out, &old)
+	out.WriteString("\n$$\n")
+	io.Copy(out, &new)
+
+	if base.Debug.Export != 0 {
+		fmt.Printf("BenchmarkExportSize:%s 1 %d bytes\n", base.Ctxt.Pkgpath, oldLen)
+		if useNewExport {
+			fmt.Printf("BenchmarkNewExportSize:%s 1 %d bytes\n", base.Ctxt.Pkgpath, newLen)
+		}
+	}
+}
diff --git a/src/cmd/compile/internal/noder/expr.go b/src/cmd/compile/internal/noder/expr.go
index c7695ed9204..3e3c352a32f 100644
--- a/src/cmd/compile/internal/noder/expr.go
+++ b/src/cmd/compile/internal/noder/expr.go
@@ -5,6 +5,8 @@
 package noder
 
 import (
+	"fmt"
+
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/syntax"
@@ -15,6 +17,8 @@ import (
 )
 
 func (g *irgen) expr(expr syntax.Expr) ir.Node {
+	expr = unparen(expr) // skip parens; unneeded after parse+typecheck
+
 	if expr == nil {
 		return nil
 	}
@@ -67,14 +71,16 @@ func (g *irgen) expr(expr syntax.Expr) ir.Node {
 
 	// Constant expression.
 	if tv.Value != nil {
-		return Const(g.pos(expr), g.typ(typ), tv.Value)
+		typ := g.typ(typ)
+		value := FixValue(typ, tv.Value)
+		return OrigConst(g.pos(expr), typ, value, constExprOp(expr), syntax.String(expr))
 	}
 
 	n := g.expr0(typ, expr)
 	if n.Typecheck() != 1 && n.Typecheck() != 3 {
 		base.FatalfAt(g.pos(expr), "missed typecheck: %+v", n)
 	}
-	if !g.match(n.Type(), typ, tv.HasOk()) {
+	if n.Op() != ir.OFUNCINST && !g.match(n.Type(), typ, tv.HasOk()) {
 		base.FatalfAt(g.pos(expr), "expected %L to have type %v", n, typ)
 	}
 	return n
@@ -82,6 +88,11 @@ func (g *irgen) expr(expr syntax.Expr) ir.Node {
 
 func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 	pos := g.pos(expr)
+	assert(pos.IsKnown())
+
+	// Set base.Pos for transformation code that still uses base.Pos, rather than
+	// the pos of the node being converted.
+	base.Pos = pos
 
 	switch expr := expr.(type) {
 	case *syntax.Name:
@@ -105,23 +116,30 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 		// The key for the Inferred map is the CallExpr (if inferring
 		// types required the function arguments) or the IndexExpr below
 		// (if types could be inferred without the function arguments).
-		if inferred, ok := g.info.Inferred[expr]; ok && len(inferred.Targs) > 0 {
+		if inferred, ok := g.info.Inferred[expr]; ok && len(inferred.TArgs) > 0 {
 			// This is the case where inferring types required the
 			// types of the function arguments.
-			targs := make([]ir.Node, len(inferred.Targs))
-			for i, targ := range inferred.Targs {
+			targs := make([]ir.Node, len(inferred.TArgs))
+			for i, targ := range inferred.TArgs {
 				targs[i] = ir.TypeNode(g.typ(targ))
 			}
 			if fun.Op() == ir.OFUNCINST {
 				// Replace explicit type args with the full list that
-				// includes the additional inferred type args
+				// includes the additional inferred type args.
+				// Substitute the type args for the type params in
+				// the generic function's type.
 				fun.(*ir.InstExpr).Targs = targs
+				newt := g.substType(fun.Type(), fun.Type().TParams(), targs)
+				typed(newt, fun)
 			} else {
-				// Create a function instantiation here, given
-				// there are only inferred type args (e.g.
-				// min(5,6), where min is a generic function)
+				// Create a function instantiation here, given there
+				// are only inferred type args (e.g. min(5,6), where
+				// min is a generic function). Substitute the type
+				// args for the type params in the generic function's
+				// type.
 				inst := ir.NewInstExpr(pos, ir.OFUNCINST, fun, targs)
-				typed(fun.Type(), inst)
+				newt := g.substType(fun.Type(), fun.Type().TParams(), targs)
+				typed(newt, inst)
 				fun = inst
 			}
 
@@ -131,12 +149,12 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 	case *syntax.IndexExpr:
 		var targs []ir.Node
 
-		if inferred, ok := g.info.Inferred[expr]; ok && len(inferred.Targs) > 0 {
+		if inferred, ok := g.info.Inferred[expr]; ok && len(inferred.TArgs) > 0 {
 			// This is the partial type inference case where the types
 			// can be inferred from other type arguments without using
 			// the types of the function arguments.
-			targs = make([]ir.Node, len(inferred.Targs))
-			for i, targ := range inferred.Targs {
+			targs = make([]ir.Node, len(inferred.TArgs))
+			for i, targ := range inferred.TArgs {
 				targs[i] = ir.TypeNode(g.typ(targ))
 			}
 		} else if _, ok := expr.Index.(*syntax.ListExpr); ok {
@@ -158,12 +176,16 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 			panic("Incorrect argument for generic func instantiation")
 		}
 		n := ir.NewInstExpr(pos, ir.OFUNCINST, x, targs)
-		typed(g.typ(typ), n)
+		newt := g.typ(typ)
+		// Substitute the type args for the type params in the uninstantiated
+		// function's type. If there aren't enough type args, then the rest
+		// will be inferred at the call node, so don't try the substitution yet.
+		if x.Type().TParams().NumFields() == len(targs) {
+			newt = g.substType(g.typ(typ), x.Type().TParams(), targs)
+		}
+		typed(newt, n)
 		return n
 
-	case *syntax.ParenExpr:
-		return g.expr(expr.X) // skip parens; unneeded after parse+typecheck
-
 	case *syntax.SelectorExpr:
 		// Qualified identifier.
 		if name, ok := expr.X.(*syntax.Name); ok {
@@ -193,7 +215,29 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 	}
 }
 
-// selectorExpr resolves the choice of ODOT, ODOTPTR, OCALLPART (eventually
+// substType does a normal type substition, but tparams is in the form of a field
+// list, and targs is in terms of a slice of type nodes. substType records any newly
+// instantiated types into g.instTypeList.
+func (g *irgen) substType(typ *types.Type, tparams *types.Type, targs []ir.Node) *types.Type {
+	fields := tparams.FieldSlice()
+	tparams1 := make([]*types.Type, len(fields))
+	for i, f := range fields {
+		tparams1[i] = f.Type
+	}
+	targs1 := make([]*types.Type, len(targs))
+	for i, n := range targs {
+		targs1[i] = n.Type()
+	}
+	ts := typecheck.Tsubster{
+		Tparams: tparams1,
+		Targs:   targs1,
+	}
+	newt := ts.Typ(typ)
+	g.instTypeList = append(g.instTypeList, ts.InstTypeList...)
+	return newt
+}
+
+// selectorExpr resolves the choice of ODOT, ODOTPTR, OMETHVALUE (eventually
 // ODOTMETH & ODOTINTER), and OMETHEXPR and deals with embedded fields here rather
 // than in typecheck.go.
 func (g *irgen) selectorExpr(pos src.XPos, typ types2.Type, expr *syntax.SelectorExpr) ir.Node {
@@ -203,6 +247,44 @@ func (g *irgen) selectorExpr(pos src.XPos, typ types2.Type, expr *syntax.Selecto
 		// only be fully transformed once it has an instantiated type.
 		n := ir.NewSelectorExpr(pos, ir.OXDOT, x, typecheck.Lookup(expr.Sel.Value))
 		typed(g.typ(typ), n)
+
+		// Fill in n.Selection for a generic method reference or a bound
+		// interface method, even though we won't use it directly, since it
+		// is useful for analysis. Specifically do not fill in for fields or
+		// other interfaces methods (method call on an interface value), so
+		// n.Selection being non-nil means a method reference for a generic
+		// type or a method reference due to a bound.
+		obj2 := g.info.Selections[expr].Obj()
+		sig := types2.AsSignature(obj2.Type())
+		if sig == nil || sig.Recv() == nil {
+			return n
+		}
+		index := g.info.Selections[expr].Index()
+		last := index[len(index)-1]
+		// recvType is the receiver of the method being called.  Because of the
+		// way methods are imported, g.obj(obj2) doesn't work across
+		// packages, so we have to lookup the method via the receiver type.
+		recvType := deref2(sig.Recv().Type())
+		if types2.AsInterface(recvType.Underlying()) != nil {
+			fieldType := n.X.Type()
+			for _, ix := range index[:len(index)-1] {
+				fieldType = fieldType.Field(ix).Type
+			}
+			if fieldType.Kind() == types.TTYPEPARAM {
+				n.Selection = fieldType.Bound().AllMethods().Index(last)
+				//fmt.Printf(">>>>> %v: Bound call %v\n", base.FmtPos(pos), n.Sel)
+			} else {
+				assert(fieldType.Kind() == types.TINTER)
+				//fmt.Printf(">>>>> %v: Interface call %v\n", base.FmtPos(pos), n.Sel)
+			}
+			return n
+		}
+
+		recvObj := types2.AsNamed(recvType).Obj()
+		recv := g.pkg(recvObj.Pkg()).Lookup(recvObj.Name()).Def
+		n.Selection = recv.Type().Methods().Index(last)
+		//fmt.Printf(">>>>> %v: Method call %v\n", base.FmtPos(pos), n.Sel)
+
 		return n
 	}
 
@@ -259,14 +341,18 @@ func (g *irgen) selectorExpr(pos src.XPos, typ types2.Type, expr *syntax.Selecto
 			if wantPtr {
 				recvType2Base = types2.AsPointer(recvType2).Elem()
 			}
-			if len(types2.AsNamed(recvType2Base).TParams()) > 0 {
+			if types2.AsNamed(recvType2Base).TParams().Len() > 0 {
 				// recvType2 is the original generic type that is
 				// instantiated for this method call.
 				// selinfo.Recv() is the instantiated type
 				recvType2 = recvType2Base
-				// method is the generic method associated with the gen type
-				method := g.obj(types2.AsNamed(recvType2).Method(last))
-				n = ir.NewSelectorExpr(pos, ir.OCALLPART, x, method.Sym())
+				recvTypeSym := g.pkg(method2.Pkg()).Lookup(recvType2.(*types2.Named).Obj().Name())
+				recvType := recvTypeSym.Def.(*ir.Name).Type()
+				// method is the generic method associated with
+				// the base generic type. The instantiated type may not
+				// have method bodies filled in, if it was imported.
+				method := recvType.Methods().Index(last).Nname.(*ir.Name)
+				n = ir.NewSelectorExpr(pos, ir.OMETHVALUE, x, typecheck.Lookup(expr.Sel.Value))
 				n.(*ir.SelectorExpr).Selection = types.NewField(pos, method.Sym(), method.Type())
 				n.(*ir.SelectorExpr).Selection.Nname = method
 				typed(method.Type(), n)
@@ -301,10 +387,7 @@ func (g *irgen) selectorExpr(pos src.XPos, typ types2.Type, expr *syntax.Selecto
 
 // getTargs gets the targs associated with the receiver of a selected method
 func getTargs(selinfo *types2.Selection) []types2.Type {
-	r := selinfo.Recv()
-	if p := types2.AsPointer(r); p != nil {
-		r = p.Elem()
-	}
+	r := deref2(selinfo.Recv())
 	n := types2.AsNamed(r)
 	if n == nil {
 		base.Fatalf("Incorrect type for selinfo %v", selinfo)
@@ -313,13 +396,17 @@ func getTargs(selinfo *types2.Selection) []types2.Type {
 }
 
 func (g *irgen) exprList(expr syntax.Expr) []ir.Node {
+	return g.exprs(unpackListExpr(expr))
+}
+
+func unpackListExpr(expr syntax.Expr) []syntax.Expr {
 	switch expr := expr.(type) {
 	case nil:
 		return nil
 	case *syntax.ListExpr:
-		return g.exprs(expr.ElemList)
+		return expr.ElemList
 	default:
-		return []ir.Node{g.expr(expr)}
+		return []syntax.Expr{expr}
 	}
 }
 
@@ -344,11 +431,13 @@ func (g *irgen) compLit(typ types2.Type, lit *syntax.CompositeLit) ir.Node {
 	for i, elem := range lit.ElemList {
 		switch elem := elem.(type) {
 		case *syntax.KeyValueExpr:
+			var key ir.Node
 			if isStruct {
-				exprs[i] = ir.NewStructKeyExpr(g.pos(elem), g.name(elem.Key.(*syntax.Name)), g.expr(elem.Value))
+				key = ir.NewIdent(g.pos(elem.Key), g.name(elem.Key.(*syntax.Name)))
 			} else {
-				exprs[i] = ir.NewKeyExpr(g.pos(elem), g.expr(elem.Key), g.expr(elem.Value))
+				key = g.expr(elem.Key)
 			}
+			exprs[i] = ir.NewKeyExpr(g.pos(elem), key, g.expr(elem.Value))
 		default:
 			exprs[i] = g.expr(elem)
 		}
@@ -360,19 +449,13 @@ func (g *irgen) compLit(typ types2.Type, lit *syntax.CompositeLit) ir.Node {
 }
 
 func (g *irgen) funcLit(typ2 types2.Type, expr *syntax.FuncLit) ir.Node {
-	fn := ir.NewFunc(g.pos(expr))
-	fn.SetIsHiddenClosure(ir.CurFunc != nil)
+	fn := ir.NewClosureFunc(g.pos(expr), ir.CurFunc != nil)
+	ir.NameClosure(fn.OClosure, ir.CurFunc)
 
-	fn.Nname = ir.NewNameAt(g.pos(expr), typecheck.ClosureName(ir.CurFunc))
-	ir.MarkFunc(fn.Nname)
 	typ := g.typ(typ2)
-	fn.Nname.Func = fn
-	fn.Nname.Defn = fn
 	typed(typ, fn.Nname)
-	fn.SetTypecheck(1)
-
-	fn.OClosure = ir.NewClosureExpr(g.pos(expr), fn)
 	typed(typ, fn.OClosure)
+	fn.SetTypecheck(1)
 
 	g.funcBody(fn, nil, expr.Type, expr.Body)
 
@@ -386,9 +469,14 @@ func (g *irgen) funcLit(typ2 types2.Type, expr *syntax.FuncLit) ir.Node {
 		cv.SetWalkdef(1)
 	}
 
-	g.target.Decls = append(g.target.Decls, fn)
-
-	return fn.OClosure
+	if g.topFuncIsGeneric {
+		// Don't add any closure inside a generic function/method to the
+		// g.target.Decls list, even though it may not be generic itself.
+		// See issue #47514.
+		return ir.UseClosure(fn.OClosure, nil)
+	} else {
+		return ir.UseClosure(fn.OClosure, g.target)
+	}
 }
 
 func (g *irgen) typeExpr(typ syntax.Expr) *types.Type {
@@ -398,3 +486,35 @@ func (g *irgen) typeExpr(typ syntax.Expr) *types.Type {
 	}
 	return n.Type()
 }
+
+// constExprOp returns an ir.Op that represents the outermost
+// operation of the given constant expression. It's intended for use
+// with ir.RawOrigExpr.
+func constExprOp(expr syntax.Expr) ir.Op {
+	switch expr := expr.(type) {
+	default:
+		panic(fmt.Sprintf("%s: unexpected expression: %T", expr.Pos(), expr))
+
+	case *syntax.BasicLit:
+		return ir.OLITERAL
+	case *syntax.Name, *syntax.SelectorExpr:
+		return ir.ONAME
+	case *syntax.CallExpr:
+		return ir.OCALL
+	case *syntax.Operation:
+		if expr.Y == nil {
+			return unOps[expr.Op]
+		}
+		return binOps[expr.Op]
+	}
+}
+
+func unparen(expr syntax.Expr) syntax.Expr {
+	for {
+		paren, ok := expr.(*syntax.ParenExpr)
+		if !ok {
+			return expr
+		}
+		expr = paren.X
+	}
+}
diff --git a/src/cmd/compile/internal/noder/frames_go1.go b/src/cmd/compile/internal/noder/frames_go1.go
new file mode 100644
index 00000000000..d00e0f51f9f
--- /dev/null
+++ b/src/cmd/compile/internal/noder/frames_go1.go
@@ -0,0 +1,21 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.7
+// +build !go1.7
+
+// TODO(mdempsky): Remove after #44505 is resolved
+
+package noder
+
+import "runtime"
+
+func walkFrames(pcs []uintptr, visit frameVisitor) {
+	for _, pc := range pcs {
+		fn := runtime.FuncForPC(pc)
+		file, line := fn.FileLine(pc)
+
+		visit(file, line, fn.Name(), pc-fn.Entry())
+	}
+}
diff --git a/src/cmd/compile/internal/noder/frames_go17.go b/src/cmd/compile/internal/noder/frames_go17.go
new file mode 100644
index 00000000000..48d77625b41
--- /dev/null
+++ b/src/cmd/compile/internal/noder/frames_go17.go
@@ -0,0 +1,25 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.7
+// +build go1.7
+
+package noder
+
+import "runtime"
+
+func walkFrames(pcs []uintptr, visit frameVisitor) {
+	if len(pcs) == 0 {
+		return
+	}
+
+	frames := runtime.CallersFrames(pcs)
+	for {
+		frame, more := frames.Next()
+		visit(frame.File, frame.Line, frame.Function, frame.PC-frame.Entry)
+		if !more {
+			return
+		}
+	}
+}
diff --git a/src/cmd/compile/internal/noder/helpers.go b/src/cmd/compile/internal/noder/helpers.go
index 9da0e493007..b9dbd030af1 100644
--- a/src/cmd/compile/internal/noder/helpers.go
+++ b/src/cmd/compile/internal/noder/helpers.go
@@ -43,6 +43,32 @@ func Const(pos src.XPos, typ *types.Type, val constant.Value) ir.Node {
 	return typed(typ, ir.NewBasicLit(pos, val))
 }
 
+func OrigConst(pos src.XPos, typ *types.Type, val constant.Value, op ir.Op, raw string) ir.Node {
+	orig := ir.NewRawOrigExpr(pos, op, raw)
+	return ir.NewConstExpr(val, typed(typ, orig))
+}
+
+// FixValue returns val after converting and truncating it as
+// appropriate for typ.
+func FixValue(typ *types.Type, val constant.Value) constant.Value {
+	assert(typ.Kind() != types.TFORW)
+	switch {
+	case typ.IsInteger():
+		val = constant.ToInt(val)
+	case typ.IsFloat():
+		val = constant.ToFloat(val)
+	case typ.IsComplex():
+		val = constant.ToComplex(val)
+	}
+	if !typ.IsUntyped() {
+		val = typecheck.DefaultLit(ir.NewBasicLit(src.NoXPos, val), typ).Val()
+	}
+	if !typ.IsTypeParam() {
+		ir.AssertValidTypeForConst(typ, val)
+	}
+	return val
+}
+
 func Nil(pos src.XPos, typ *types.Type) ir.Node {
 	return typed(typ, ir.NewNilExpr(pos))
 }
@@ -87,15 +113,15 @@ func Binary(pos src.XPos, op ir.Op, typ *types.Type, x, y ir.Node) ir.Node {
 func Call(pos src.XPos, typ *types.Type, fun ir.Node, args []ir.Node, dots bool) ir.Node {
 	n := ir.NewCallExpr(pos, ir.OCALL, fun, args)
 	n.IsDDD = dots
-	// n.Use will be changed to ir.CallUseStmt in g.stmt() if this call is
-	// just a statement (any return values are ignored).
-	n.Use = ir.CallUseExpr
 
 	if fun.Op() == ir.OTYPE {
 		// Actually a type conversion, not a function call.
-		if fun.Type().HasTParam() || args[0].Type().HasTParam() {
-			// For type params, don't typecheck until we actually know
-			// the type.
+		if !fun.Type().IsInterface() &&
+			(fun.Type().HasTParam() || args[0].Type().HasTParam()) {
+			// For type params, we can transform if fun.Type() is known
+			// to be an interface (in which case a CONVIFACE node will be
+			// inserted). Otherwise, don't typecheck until we actually
+			// know the type.
 			return typed(typ, n)
 		}
 		typed(typ, n)
@@ -103,22 +129,17 @@ func Call(pos src.XPos, typ *types.Type, fun ir.Node, args []ir.Node, dots bool)
 	}
 
 	if fun, ok := fun.(*ir.Name); ok && fun.BuiltinOp != 0 {
-		// For Builtin ops, we currently stay with using the old
-		// typechecker to transform the call to a more specific expression
-		// and possibly use more specific ops. However, for a bunch of the
-		// ops, we delay doing the old typechecker if any of the args have
-		// type params, for a variety of reasons:
+		// For most Builtin ops, we delay doing transformBuiltin if any of the
+		// args have type params, for a variety of reasons:
 		//
-		// OMAKE: hard to choose specific ops OMAKESLICE, etc. until arg type is known
-		// OREAL/OIMAG: can't determine type float32/float64 until arg type know
-		// OLEN/OCAP: old typechecker will complain if arg is not obviously a slice/array.
-		// OAPPEND: old typechecker will complain if arg is not obviously slice, etc.
-		//
-		// We will eventually break out the transforming functionality
-		// needed for builtin's, and call it here or during stenciling, as
-		// appropriate.
+		// OMAKE: transformMake can't choose specific ops OMAKESLICE, etc.
+		//    until arg type is known
+		// OREAL/OIMAG: transformRealImag can't determine type float32/float64
+		//    until arg type known
+		// OAPPEND: transformAppend requires that the arg is a slice
+		// ODELETE: transformDelete requires that the arg is a map
 		switch fun.BuiltinOp {
-		case ir.OMAKE, ir.OREAL, ir.OIMAG, ir.OLEN, ir.OCAP, ir.OAPPEND:
+		case ir.OMAKE, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.ODELETE:
 			hasTParam := false
 			for _, arg := range args {
 				if arg.Type().HasTParam() {
@@ -137,10 +158,8 @@ func Call(pos src.XPos, typ *types.Type, fun ir.Node, args []ir.Node, dots bool)
 
 	// Add information, now that we know that fun is actually being called.
 	switch fun := fun.(type) {
-	case *ir.ClosureExpr:
-		fun.Func.SetClosureCalled(true)
 	case *ir.SelectorExpr:
-		if fun.Op() == ir.OCALLPART {
+		if fun.Op() == ir.OMETHVALUE {
 			op := ir.ODOTMETH
 			if fun.X.Type().IsInterface() {
 				op = ir.ODOTINTER
@@ -152,46 +171,52 @@ func Call(pos src.XPos, typ *types.Type, fun ir.Node, args []ir.Node, dots bool)
 		}
 	}
 
-	if fun.Type().HasTParam() {
-		// If the fun arg is or has a type param, don't do any extra
+	if fun.Type().HasTParam() || fun.Op() == ir.OXDOT || fun.Op() == ir.OFUNCINST {
+		// If the fun arg is or has a type param, we can't do all the
 		// transformations, since we may not have needed properties yet
-		// (e.g. number of return values, etc). The type param is probably
-		// described by a structural constraint that requires it to be a
-		// certain function type, etc., but we don't want to analyze that.
+		// (e.g. number of return values, etc). The same applies if a fun
+		// which is an XDOT could not be transformed yet because of a generic
+		// type in the X of the selector expression.
+		//
+		// A function instantiation (even if fully concrete) shouldn't be
+		// transformed yet, because we need to add the dictionary during the
+		// transformation.
+		//
+		// However, if we have a function type (even though it is
+		// parameterized), then we can add in any needed CONVIFACE nodes via
+		// typecheckaste(). We need to call transformArgs() to deal first
+		// with the f(g(()) case where g returns multiple return values. We
+		// can't do anything if fun is a type param (which is probably
+		// described by a structural constraint)
+		if fun.Type().Kind() == types.TFUNC {
+			transformArgs(n)
+			typecheckaste(ir.OCALL, fun, n.IsDDD, fun.Type().Params(), n.Args, true)
+		}
 		return typed(typ, n)
 	}
 
-	if fun.Op() == ir.OXDOT {
-		if !fun.(*ir.SelectorExpr).X.Type().HasTParam() {
-			base.FatalfAt(pos, "Expecting type param receiver in %v", fun)
-		}
-		// For methods called in a generic function, don't do any extra
-		// transformations. We will do those later when we create the
-		// instantiated function and have the correct receiver type.
-		typed(typ, n)
-		return n
-	}
-	if fun.Op() != ir.OFUNCINST {
-		// If no type params, do the normal call transformations. This
-		// will convert OCALL to OCALLFUNC.
-		typed(typ, n)
-		transformCall(n)
-		return n
-	}
-
-	// Leave the op as OCALL, which indicates the call still needs typechecking.
+	// If no type params, do the normal call transformations. This
+	// will convert OCALL to OCALLFUNC.
 	typed(typ, n)
+	transformCall(n)
 	return n
 }
 
 func Compare(pos src.XPos, typ *types.Type, op ir.Op, x, y ir.Node) ir.Node {
 	n := ir.NewBinaryExpr(pos, op, x, y)
 	if x.Type().HasTParam() || y.Type().HasTParam() {
-		// Delay transformCompare() if either arg has a type param, since
-		// it needs to know the exact types to decide on any needed conversions.
-		n.SetType(typ)
-		n.SetTypecheck(3)
-		return n
+		xIsInt := x.Type().IsInterface()
+		yIsInt := y.Type().IsInterface()
+		if !(xIsInt && !yIsInt || !xIsInt && yIsInt) {
+			// If either arg is a type param, then we can still do the
+			// transformCompare() if we know that one arg is an interface
+			// and the other is not. Otherwise, we delay
+			// transformCompare(), since it needs to know the exact types
+			// to decide on any needed conversions.
+			n.SetType(typ)
+			n.SetTypecheck(3)
+			return n
+		}
 	}
 	typed(typ, n)
 	transformCompare(n)
@@ -225,7 +250,7 @@ func DotMethod(pos src.XPos, x ir.Node, index int) *ir.SelectorExpr {
 
 	// Method value.
 	typ := typecheck.NewMethodType(method.Type, nil)
-	return dot(pos, typ, ir.OCALLPART, x, method)
+	return dot(pos, typ, ir.OMETHVALUE, x, method)
 }
 
 // MethodExpr returns a OMETHEXPR node with the indicated index into the methods
@@ -321,5 +346,15 @@ var one = constant.MakeInt64(1)
 
 func IncDec(pos src.XPos, op ir.Op, x ir.Node) *ir.AssignOpStmt {
 	assert(x.Type() != nil)
-	return ir.NewAssignOpStmt(pos, op, x, typecheck.DefaultLit(ir.NewBasicLit(pos, one), x.Type()))
+	bl := ir.NewBasicLit(pos, one)
+	if x.Type().HasTParam() {
+		// If the operand is generic, then types2 will have proved it must be
+		// a type that fits with increment/decrement, so just set the type of
+		// "one" to n.Type(). This works even for types that are eventually
+		// float or complex.
+		typed(x.Type(), bl)
+	} else {
+		bl = typecheck.DefaultLit(bl, x.Type())
+	}
+	return ir.NewAssignOpStmt(pos, op, x, bl)
 }
diff --git a/src/cmd/compile/internal/noder/import.go b/src/cmd/compile/internal/noder/import.go
index 701e9001c85..48f0e480284 100644
--- a/src/cmd/compile/internal/noder/import.go
+++ b/src/cmd/compile/internal/noder/import.go
@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"internal/buildcfg"
-	"io"
 	"os"
 	pathpkg "path"
 	"runtime"
@@ -32,8 +31,24 @@ import (
 	"cmd/internal/src"
 )
 
-// Temporary import helper to get type2-based type-checking going.
+// haveLegacyImports records whether we've imported any packages
+// without a new export data section. This is useful for experimenting
+// with new export data format designs, when you need to support
+// existing tests that manually compile files with inconsistent
+// compiler flags.
+var haveLegacyImports = false
+
+// newReadImportFunc is an extension hook for experimenting with new
+// export data formats. If a new export data payload was written out
+// for an imported package by overloading writeNewExportFunc, then
+// that payload will be mapped into memory and passed to
+// newReadImportFunc.
+var newReadImportFunc = func(data string, pkg1 *types.Pkg, check *types2.Checker, packages map[string]*types2.Package) (pkg2 *types2.Package, err error) {
+	panic("unexpected new export data payload")
+}
+
 type gcimports struct {
+	check    *types2.Checker
 	packages map[string]*types2.Package
 }
 
@@ -46,13 +61,8 @@ func (m *gcimports) ImportFrom(path, srcDir string, mode types2.ImportMode) (*ty
 		panic("mode must be 0")
 	}
 
-	path, err := resolveImportPath(path)
-	if err != nil {
-		return nil, err
-	}
-
-	lookup := func(path string) (io.ReadCloser, error) { return openPackage(path) }
-	return importer.Import(m.packages, path, srcDir, lookup)
+	_, pkg, err := readImportFile(path, typecheck.Target, m.check, m.packages)
+	return pkg, err
 }
 
 func isDriveLetter(b byte) bool {
@@ -175,160 +185,242 @@ func resolveImportPath(path string) (string, error) {
 	return path, nil
 }
 
-// TODO(mdempsky): Return an error instead.
 func importfile(decl *syntax.ImportDecl) *types.Pkg {
-	if decl.Path.Kind != syntax.StringLit {
-		base.Errorf("import path must be a string")
-		return nil
-	}
-
-	path, err := strconv.Unquote(decl.Path.Value)
-	if err != nil {
-		base.Errorf("import path must be a string")
-		return nil
-	}
-
-	if err := checkImportPath(path, false); err != nil {
-		base.Errorf("%s", err.Error())
-		return nil
-	}
-
-	path, err = resolveImportPath(path)
+	path, err := parseImportPath(decl.Path)
 	if err != nil {
 		base.Errorf("%s", err)
 		return nil
 	}
 
-	importpkg := types.NewPkg(path, "")
-	if importpkg.Direct {
-		return importpkg // already fully loaded
+	pkg, _, err := readImportFile(path, typecheck.Target, nil, nil)
+	if err != nil {
+		base.Errorf("%s", err)
+		return nil
+	}
+
+	if pkg != ir.Pkgs.Unsafe && pkg.Height >= myheight {
+		myheight = pkg.Height + 1
+	}
+	return pkg
+}
+
+func parseImportPath(pathLit *syntax.BasicLit) (string, error) {
+	if pathLit.Kind != syntax.StringLit {
+		return "", errors.New("import path must be a string")
+	}
+
+	path, err := strconv.Unquote(pathLit.Value)
+	if err != nil {
+		return "", errors.New("import path must be a string")
+	}
+
+	if err := checkImportPath(path, false); err != nil {
+		return "", err
+	}
+
+	return path, err
+}
+
+// readImportFile reads the import file for the given package path and
+// returns its types.Pkg representation. If packages is non-nil, the
+// types2.Package representation is also returned.
+func readImportFile(path string, target *ir.Package, check *types2.Checker, packages map[string]*types2.Package) (pkg1 *types.Pkg, pkg2 *types2.Package, err error) {
+	path, err = resolveImportPath(path)
+	if err != nil {
+		return
 	}
-	importpkg.Direct = true
-	typecheck.Target.Imports = append(typecheck.Target.Imports, importpkg)
 
 	if path == "unsafe" {
-		return importpkg // initialized with universe
+		pkg1, pkg2 = ir.Pkgs.Unsafe, types2.Unsafe
+
+		// TODO(mdempsky): Investigate if this actually matters. Why would
+		// the linker or runtime care whether a package imported unsafe?
+		if !pkg1.Direct {
+			pkg1.Direct = true
+			target.Imports = append(target.Imports, pkg1)
+		}
+
+		return
 	}
 
+	pkg1 = types.NewPkg(path, "")
+	if packages != nil {
+		pkg2 = packages[path]
+		assert(pkg1.Direct == (pkg2 != nil && pkg2.Complete()))
+	}
+
+	if pkg1.Direct {
+		return
+	}
+	pkg1.Direct = true
+	target.Imports = append(target.Imports, pkg1)
+
 	f, err := openPackage(path)
 	if err != nil {
-		base.Errorf("could not import %q: %v", path, err)
-		base.ErrorExit()
+		return
 	}
-	imp := bio.NewReader(f)
-	defer imp.Close()
-	file := f.Name()
+	defer f.Close()
 
-	// check object header
-	p, err := imp.ReadString('\n')
+	r, end, newsize, err := findExportData(f)
 	if err != nil {
-		base.Errorf("import %s: reading input: %v", file, err)
-		base.ErrorExit()
+		return
 	}
 
-	if p == "!\n" { // package archive
-		// package export block should be first
-		sz := archive.ReadHeader(imp.Reader, "__.PKGDEF")
-		if sz <= 0 {
-			base.Errorf("import %s: not a package file", file)
-			base.ErrorExit()
-		}
-		p, err = imp.ReadString('\n')
+	if base.Debug.Export != 0 {
+		fmt.Printf("importing %s (%s)\n", path, f.Name())
+	}
+
+	if newsize != 0 {
+		// We have unified IR data. Map it, and feed to the importers.
+		end -= newsize
+		var data string
+		data, err = base.MapFile(r.File(), end, newsize)
 		if err != nil {
-			base.Errorf("import %s: reading input: %v", file, err)
-			base.ErrorExit()
+			return
 		}
-	}
 
-	if !strings.HasPrefix(p, "go object ") {
-		base.Errorf("import %s: not a go object file: %s", file, p)
-		base.ErrorExit()
-	}
-	q := objabi.HeaderString()
-	if p != q {
-		base.Errorf("import %s: object is [%s] expected [%s]", file, p, q)
-		base.ErrorExit()
-	}
+		pkg2, err = newReadImportFunc(data, pkg1, check, packages)
+	} else {
+		// We only have old data. Oh well, fall back to the legacy importers.
+		haveLegacyImports = true
 
-	// process header lines
-	for {
-		p, err = imp.ReadString('\n')
+		var c byte
+		switch c, err = r.ReadByte(); {
+		case err != nil:
+			return
+
+		case c != 'i':
+			// Indexed format is distinguished by an 'i' byte,
+			// whereas previous export formats started with 'c', 'd', or 'v'.
+			err = fmt.Errorf("unexpected package format byte: %v", c)
+			return
+		}
+
+		pos := r.Offset()
+
+		// Map string (and data) section into memory as a single large
+		// string. This reduces heap fragmentation and allows
+		// returning individual substrings very efficiently.
+		var data string
+		data, err = base.MapFile(r.File(), pos, end-pos)
 		if err != nil {
-			base.Errorf("import %s: reading input: %v", file, err)
-			base.ErrorExit()
+			return
 		}
-		if p == "\n" {
-			break // header ends with blank line
-		}
-	}
 
-	// Expect $$B\n to signal binary import format.
+		typecheck.ReadImports(pkg1, data)
 
-	// look for $$
-	var c byte
-	for {
-		c, err = imp.ReadByte()
-		if err != nil {
-			break
-		}
-		if c == '$' {
-			c, err = imp.ReadByte()
-			if c == '$' || err != nil {
-				break
+		if packages != nil {
+			pkg2, err = importer.ImportData(packages, data, path)
+			if err != nil {
+				return
 			}
 		}
 	}
 
-	// get character after $$
-	if err == nil {
-		c, _ = imp.ReadByte()
+	err = addFingerprint(path, f, end)
+	return
+}
+
+// findExportData returns a *bio.Reader positioned at the start of the
+// binary export data section, and a file offset for where to stop
+// reading.
+func findExportData(f *os.File) (r *bio.Reader, end, newsize int64, err error) {
+	r = bio.NewReader(f)
+
+	// check object header
+	line, err := r.ReadString('\n')
+	if err != nil {
+		return
 	}
 
-	var fingerprint goobj.FingerprintType
-	switch c {
-	case '\n':
-		base.Errorf("cannot import %s: old export format no longer supported (recompile library)", path)
-		return nil
-
-	case 'B':
-		if base.Debug.Export != 0 {
-			fmt.Printf("importing %s (%s)\n", path, file)
+	if line == "!\n" { // package archive
+		// package export block should be first
+		sz := int64(archive.ReadHeader(r.Reader, "__.PKGDEF"))
+		if sz <= 0 {
+			err = errors.New("not a package file")
+			return
 		}
-		imp.ReadByte() // skip \n after $$B
-
-		c, err = imp.ReadByte()
+		end = r.Offset() + sz
+		line, err = r.ReadString('\n')
 		if err != nil {
-			base.Errorf("import %s: reading input: %v", file, err)
-			base.ErrorExit()
+			return
 		}
-
-		// Indexed format is distinguished by an 'i' byte,
-		// whereas previous export formats started with 'c', 'd', or 'v'.
-		if c != 'i' {
-			base.Errorf("import %s: unexpected package format byte: %v", file, c)
-			base.ErrorExit()
+	} else {
+		// Not an archive; provide end of file instead.
+		// TODO(mdempsky): I don't think this happens anymore.
+		var fi os.FileInfo
+		fi, err = f.Stat()
+		if err != nil {
+			return
 		}
-		fingerprint = typecheck.ReadImports(importpkg, imp)
-
-	default:
-		base.Errorf("no import in %q", path)
-		base.ErrorExit()
+		end = fi.Size()
 	}
 
+	if !strings.HasPrefix(line, "go object ") {
+		err = fmt.Errorf("not a go object file: %s", line)
+		return
+	}
+	if expect := objabi.HeaderString(); line != expect {
+		err = fmt.Errorf("object is [%s] expected [%s]", line, expect)
+		return
+	}
+
+	// process header lines
+	for !strings.HasPrefix(line, "$$") {
+		if strings.HasPrefix(line, "newexportsize ") {
+			fields := strings.Fields(line)
+			newsize, err = strconv.ParseInt(fields[1], 10, 64)
+			if err != nil {
+				return
+			}
+		}
+
+		line, err = r.ReadString('\n')
+		if err != nil {
+			return
+		}
+	}
+
+	// Expect $$B\n to signal binary import format.
+	if line != "$$B\n" {
+		err = errors.New("old export format no longer supported (recompile library)")
+		return
+	}
+
+	return
+}
+
+// addFingerprint reads the linker fingerprint included at the end of
+// the exportdata.
+func addFingerprint(path string, f *os.File, end int64) error {
+	const eom = "\n$$\n"
+	var fingerprint goobj.FingerprintType
+
+	var buf [len(fingerprint) + len(eom)]byte
+	if _, err := f.ReadAt(buf[:], end-int64(len(buf))); err != nil {
+		return err
+	}
+
+	// Caller should have given us the end position of the export data,
+	// which should end with the "\n$$\n" marker. As a consistency check
+	// to make sure we're reading at the right offset, make sure we
+	// found the marker.
+	if s := string(buf[len(fingerprint):]); s != eom {
+		return fmt.Errorf("expected $$ marker, but found %q", s)
+	}
+
+	copy(fingerprint[:], buf[:])
+
 	// assume files move (get installed) so don't record the full path
 	if base.Flag.Cfg.PackageFile != nil {
 		// If using a packageFile map, assume path_ can be recorded directly.
 		base.Ctxt.AddImport(path, fingerprint)
 	} else {
 		// For file "/Users/foo/go/pkg/darwin_amd64/math.a" record "math.a".
+		file := f.Name()
 		base.Ctxt.AddImport(file[len(file)-len(path)-len(".a"):], fingerprint)
 	}
-
-	if importpkg.Height >= myheight {
-		myheight = importpkg.Height + 1
-	}
-
-	return importpkg
+	return nil
 }
 
 // The linker uses the magic symbol prefixes "go." and "type."
@@ -431,7 +523,7 @@ func clearImports() {
 			s.Def = nil
 			continue
 		}
-		if types.IsDotAlias(s) {
+		if s.Def != nil && s.Def.Sym() != s {
 			// throw away top-level name left over
 			// from previous import . "x"
 			// We'll report errors after type checking in CheckDotImports.
diff --git a/src/cmd/compile/internal/noder/irgen.go b/src/cmd/compile/internal/noder/irgen.go
index 3e0d3285ab9..7bc8a6bcc32 100644
--- a/src/cmd/compile/internal/noder/irgen.go
+++ b/src/cmd/compile/internal/noder/irgen.go
@@ -18,9 +18,9 @@ import (
 	"cmd/internal/src"
 )
 
-// check2 type checks a Go package using types2, and then generates IR
-// using the results.
-func check2(noders []*noder) {
+// checkFiles configures and runs the types2 checker on the given
+// parsed source files and then returns the result.
+func checkFiles(noders []*noder) (posMap, *types2.Package, *types2.Info) {
 	if base.SyntaxErrors() != 0 {
 		base.ErrorExit()
 	}
@@ -34,20 +34,22 @@ func check2(noders []*noder) {
 	}
 
 	// typechecking
+	importer := gcimports{
+		packages: make(map[string]*types2.Package),
+	}
 	conf := types2.Config{
 		GoVersion:             base.Flag.Lang,
 		IgnoreLabels:          true, // parser already checked via syntax.CheckBranches mode
 		CompilerErrorMessages: true, // use error strings matching existing compiler errors
+		AllowTypeLists:        true, // remove this line once all tests use type set syntax
 		Error: func(err error) {
 			terr := err.(types2.Error)
 			base.ErrorfAt(m.makeXPos(terr.Pos), "%s", terr.Msg)
 		},
-		Importer: &gcimports{
-			packages: make(map[string]*types2.Package),
-		},
-		Sizes: &gcSizes{},
+		Importer: &importer,
+		Sizes:    &gcSizes{},
 	}
-	info := types2.Info{
+	info := &types2.Info{
 		Types:      make(map[syntax.Expr]types2.TypeAndValue),
 		Defs:       make(map[*syntax.Name]types2.Object),
 		Uses:       make(map[*syntax.Name]types2.Object),
@@ -57,12 +59,24 @@ func check2(noders []*noder) {
 		Inferred:   make(map[syntax.Expr]types2.Inferred),
 		// expand as needed
 	}
-	pkg, err := conf.Check(base.Ctxt.Pkgpath, files, &info)
-	files = nil
+
+	pkg := types2.NewPackage(base.Ctxt.Pkgpath, "")
+	importer.check = types2.NewChecker(&conf, pkg, info)
+	err := importer.check.Files(files)
+
 	base.ExitIfErrors()
 	if err != nil {
 		base.FatalfAt(src.NoXPos, "conf.Check error: %v", err)
 	}
+
+	return m, pkg, info
+}
+
+// check2 type checks a Go package using types2, and then generates IR
+// using the results.
+func check2(noders []*noder) {
+	m, pkg, info := checkFiles(noders)
+
 	if base.Flag.G < 2 {
 		os.Exit(0)
 	}
@@ -70,7 +84,7 @@ func check2(noders []*noder) {
 	g := irgen{
 		target: typecheck.Target,
 		self:   pkg,
-		info:   &info,
+		info:   info,
 		posMap: m,
 		objs:   make(map[types2.Object]*ir.Name),
 		typs:   make(map[types2.Type]*types.Type),
@@ -82,6 +96,41 @@ func check2(noders []*noder) {
 	}
 }
 
+// gfInfo is information gathered on a generic function.
+type gfInfo struct {
+	tparams      []*types.Type
+	derivedTypes []*types.Type
+	// Nodes in generic function that requires a subdictionary. Includes
+	// method and function calls (OCALL), function values (OFUNCINST), method
+	// values/expressions (OXDOT).
+	subDictCalls []ir.Node
+	// Nodes in generic functions that are a conversion from a typeparam/derived
+	// type to a specific interface.
+	itabConvs []ir.Node
+	// For type switches on nonempty interfaces, a map from OTYPE entries of
+	// HasTParam type, to the interface type we're switching from.
+	// TODO: what if the type we're switching from is a shape type?
+	type2switchType map[ir.Node]*types.Type
+}
+
+// instInfo is information gathered on an gcshape (or fully concrete)
+// instantiation of a function.
+type instInfo struct {
+	fun       *ir.Func // The instantiated function (with body)
+	dictParam *ir.Name // The node inside fun that refers to the dictionary param
+
+	gf     *ir.Name // The associated generic function
+	gfInfo *gfInfo
+
+	startSubDict  int // Start of dict entries for subdictionaries
+	startItabConv int // Start of dict entries for itab conversions
+	dictLen       int // Total number of entries in dictionary
+
+	// Map from nodes in instantiated fun (OCALL, OCALLMETHOD, OFUNCINST, and
+	// OMETHEXPR) to the associated dictionary entry for a sub-dictionary
+	dictEntryMap map[ir.Node]int
+}
+
 type irgen struct {
 	target *ir.Package
 	self   *types2.Package
@@ -94,10 +143,38 @@ type irgen struct {
 
 	// Fully-instantiated generic types whose methods should be instantiated
 	instTypeList []*types.Type
+
+	dnum int // for generating unique dictionary variables
+
+	// Map from generic function to information about its type params, derived
+	// types, and subdictionaries.
+	gfInfoMap map[*types.Sym]*gfInfo
+
+	// Map from a name of function that been instantiated to information about
+	// its instantiated function, associated generic function/method, and the
+	// mapping from IR nodes to dictionary entries.
+	instInfoMap map[*types.Sym]*instInfo
+
+	// dictionary syms which we need to finish, by writing out any itabconv
+	// entries.
+	dictSymsToFinalize []*delayInfo
+
+	// True when we are compiling a top-level generic function or method. Use to
+	// avoid adding closures of generic functions/methods to the target.Decls
+	// list.
+	topFuncIsGeneric bool
+}
+
+type delayInfo struct {
+	gf    *ir.Name
+	targs []*types.Type
+	sym   *types.Sym
+	off   int
 }
 
 func (g *irgen) generate(noders []*noder) {
 	types.LocalPkg.Name = g.self.Name()
+	types.LocalPkg.Height = g.self.Height()
 	typecheck.TypecheckAllowed = true
 
 	// Prevent size calculations until we set the underlying type
@@ -132,7 +209,6 @@ Outer:
 			}
 		}
 	}
-	types.LocalPkg.Height = myheight
 
 	// 2. Process all package-block type declarations. As with imports,
 	// we need to make sure all types are properly instantiated before
@@ -167,6 +243,10 @@ Outer:
 		}
 	}
 
+	// Check for unusual case where noder2 encounters a type error that types2
+	// doesn't check for (e.g. notinheap incompatibility).
+	base.ExitIfErrors()
+
 	typecheck.DeclareUniverse()
 
 	for _, p := range noders {
@@ -175,7 +255,7 @@ Outer:
 
 		// Double check for any type-checking inconsistencies. This can be
 		// removed once we're confident in IR generation results.
-		syntax.Walk(p.file, func(n syntax.Node) bool {
+		syntax.Crawl(p.file, func(n syntax.Node) bool {
 			g.validate(n)
 			return false
 		})
@@ -184,9 +264,9 @@ Outer:
 	// Create any needed stencils of generic functions
 	g.stencil()
 
-	// For now, remove all generic functions from g.target.Decl, since they
-	// have been used for stenciling, but don't compile. TODO: We will
-	// eventually export any exportable generic functions.
+	// Remove all generic functions from g.target.Decl, since they have been
+	// used for stenciling, but don't compile. Generic functions will already
+	// have been marked for export as appropriate.
 	j := 0
 	for i, decl := range g.target.Decls {
 		if decl.Op() != ir.ODCLFUNC || !decl.Type().HasTParam() {
diff --git a/src/cmd/compile/internal/noder/linker.go b/src/cmd/compile/internal/noder/linker.go
new file mode 100644
index 00000000000..2bc7f7c608e
--- /dev/null
+++ b/src/cmd/compile/internal/noder/linker.go
@@ -0,0 +1,296 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"io"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/reflectdata"
+	"cmd/compile/internal/types"
+	"cmd/internal/goobj"
+	"cmd/internal/obj"
+)
+
+// This file implements the unified IR linker, which combines the
+// local package's stub data with imported package data to produce a
+// complete export data file. It also rewrites the compiler's
+// extension data sections based on the results of compilation (e.g.,
+// the function inlining cost and linker symbol index assignments).
+//
+// TODO(mdempsky): Using the name "linker" here is confusing, because
+// readers are likely to mistake references to it for cmd/link. But
+// there's a shortage of good names for "something that combines
+// multiple parts into a cohesive whole"... e.g., "assembler" and
+// "compiler" are also already taken.
+
+type linker struct {
+	pw pkgEncoder
+
+	pkgs  map[string]int
+	decls map[*types.Sym]int
+}
+
+func (l *linker) relocAll(pr *pkgReader, relocs []relocEnt) []relocEnt {
+	res := make([]relocEnt, len(relocs))
+	for i, rent := range relocs {
+		rent.idx = l.relocIdx(pr, rent.kind, rent.idx)
+		res[i] = rent
+	}
+	return res
+}
+
+func (l *linker) relocIdx(pr *pkgReader, k reloc, idx int) int {
+	assert(pr != nil)
+
+	absIdx := pr.absIdx(k, idx)
+
+	if newidx := pr.newindex[absIdx]; newidx != 0 {
+		return ^newidx
+	}
+
+	var newidx int
+	switch k {
+	case relocString:
+		newidx = l.relocString(pr, idx)
+	case relocPkg:
+		newidx = l.relocPkg(pr, idx)
+	case relocObj:
+		newidx = l.relocObj(pr, idx)
+
+	default:
+		// Generic relocations.
+		//
+		// TODO(mdempsky): Deduplicate more sections? In fact, I think
+		// every section could be deduplicated. This would also be easier
+		// if we do external relocations.
+
+		w := l.pw.newEncoderRaw(k)
+		l.relocCommon(pr, &w, k, idx)
+		newidx = w.idx
+	}
+
+	pr.newindex[absIdx] = ^newidx
+
+	return newidx
+}
+
+func (l *linker) relocString(pr *pkgReader, idx int) int {
+	return l.pw.stringIdx(pr.stringIdx(idx))
+}
+
+func (l *linker) relocPkg(pr *pkgReader, idx int) int {
+	path := pr.peekPkgPath(idx)
+
+	if newidx, ok := l.pkgs[path]; ok {
+		return newidx
+	}
+
+	r := pr.newDecoder(relocPkg, idx, syncPkgDef)
+	w := l.pw.newEncoder(relocPkg, syncPkgDef)
+	l.pkgs[path] = w.idx
+
+	// TODO(mdempsky): We end up leaving an empty string reference here
+	// from when the package was originally written as "". Probably not
+	// a big deal, but a little annoying. Maybe relocating
+	// cross-references in place is the way to go after all.
+	w.relocs = l.relocAll(pr, r.relocs)
+
+	_ = r.string() // original path
+	w.string(path)
+
+	io.Copy(&w.data, &r.data)
+
+	return w.flush()
+}
+
+func (l *linker) relocObj(pr *pkgReader, idx int) int {
+	path, name, tag := pr.peekObj(idx)
+	sym := types.NewPkg(path, "").Lookup(name)
+
+	if newidx, ok := l.decls[sym]; ok {
+		return newidx
+	}
+
+	if tag == objStub && path != "builtin" && path != "unsafe" {
+		pri, ok := objReader[sym]
+		if !ok {
+			base.Fatalf("missing reader for %q.%v", path, name)
+		}
+		assert(ok)
+
+		pr = pri.pr
+		idx = pri.idx
+
+		path2, name2, tag2 := pr.peekObj(idx)
+		sym2 := types.NewPkg(path2, "").Lookup(name2)
+		assert(sym == sym2)
+		assert(tag2 != objStub)
+	}
+
+	w := l.pw.newEncoderRaw(relocObj)
+	wext := l.pw.newEncoderRaw(relocObjExt)
+	wname := l.pw.newEncoderRaw(relocName)
+	wdict := l.pw.newEncoderRaw(relocObjDict)
+
+	l.decls[sym] = w.idx
+	assert(wext.idx == w.idx)
+	assert(wname.idx == w.idx)
+	assert(wdict.idx == w.idx)
+
+	l.relocCommon(pr, &w, relocObj, idx)
+	l.relocCommon(pr, &wname, relocName, idx)
+	l.relocCommon(pr, &wdict, relocObjDict, idx)
+
+	var obj *ir.Name
+	if path == "" {
+		var ok bool
+		obj, ok = sym.Def.(*ir.Name)
+
+		// Generic types and functions and declared constraint types won't
+		// have definitions.
+		// For now, just generically copy their extension data.
+		// TODO(mdempsky): Restore assertion.
+		if !ok && false {
+			base.Fatalf("missing definition for %v", sym)
+		}
+	}
+
+	if obj != nil {
+		wext.sync(syncObject1)
+		switch tag {
+		case objFunc:
+			l.relocFuncExt(&wext, obj)
+		case objType:
+			l.relocTypeExt(&wext, obj)
+		case objVar:
+			l.relocVarExt(&wext, obj)
+		}
+		wext.flush()
+	} else {
+		l.relocCommon(pr, &wext, relocObjExt, idx)
+	}
+
+	return w.idx
+}
+
+func (l *linker) relocCommon(pr *pkgReader, w *encoder, k reloc, idx int) {
+	r := pr.newDecoderRaw(k, idx)
+	w.relocs = l.relocAll(pr, r.relocs)
+	io.Copy(&w.data, &r.data)
+	w.flush()
+}
+
+func (l *linker) pragmaFlag(w *encoder, pragma ir.PragmaFlag) {
+	w.sync(syncPragma)
+	w.int(int(pragma))
+}
+
+func (l *linker) relocFuncExt(w *encoder, name *ir.Name) {
+	w.sync(syncFuncExt)
+
+	l.pragmaFlag(w, name.Func.Pragma)
+	l.linkname(w, name)
+
+	// Relocated extension data.
+	w.bool(true)
+
+	// Record definition ABI so cross-ABI calls can be direct.
+	// This is important for the performance of calling some
+	// common functions implemented in assembly (e.g., bytealg).
+	w.uint64(uint64(name.Func.ABI))
+
+	// Escape analysis.
+	for _, fs := range &types.RecvsParams {
+		for _, f := range fs(name.Type()).FieldSlice() {
+			w.string(f.Note)
+		}
+	}
+
+	if inl := name.Func.Inl; w.bool(inl != nil) {
+		w.len(int(inl.Cost))
+		w.bool(inl.CanDelayResults)
+
+		pri, ok := bodyReader[name.Func]
+		assert(ok)
+		w.reloc(relocBody, l.relocIdx(pri.pr, relocBody, pri.idx))
+	}
+
+	w.sync(syncEOF)
+}
+
+func (l *linker) relocTypeExt(w *encoder, name *ir.Name) {
+	w.sync(syncTypeExt)
+
+	typ := name.Type()
+
+	l.pragmaFlag(w, name.Pragma())
+
+	// For type T, export the index of type descriptor symbols of T and *T.
+	l.lsymIdx(w, "", reflectdata.TypeLinksym(typ))
+	l.lsymIdx(w, "", reflectdata.TypeLinksym(typ.PtrTo()))
+
+	if typ.Kind() != types.TINTER {
+		for _, method := range typ.Methods().Slice() {
+			l.relocFuncExt(w, method.Nname.(*ir.Name))
+		}
+	}
+}
+
+func (l *linker) relocVarExt(w *encoder, name *ir.Name) {
+	w.sync(syncVarExt)
+	l.linkname(w, name)
+}
+
+func (l *linker) linkname(w *encoder, name *ir.Name) {
+	w.sync(syncLinkname)
+
+	linkname := name.Sym().Linkname
+	if !l.lsymIdx(w, linkname, name.Linksym()) {
+		w.string(linkname)
+	}
+}
+
+func (l *linker) lsymIdx(w *encoder, linkname string, lsym *obj.LSym) bool {
+	if lsym.PkgIdx > goobj.PkgIdxSelf || (lsym.PkgIdx == goobj.PkgIdxInvalid && !lsym.Indexed()) || linkname != "" {
+		w.int64(-1)
+		return false
+	}
+
+	// For a defined symbol, export its index.
+	// For re-exporting an imported symbol, pass its index through.
+	w.int64(int64(lsym.SymIdx))
+	return true
+}
+
+// @@@ Helpers
+
+// TODO(mdempsky): These should probably be removed. I think they're a
+// smell that the export data format is not yet quite right.
+
+func (pr *pkgDecoder) peekPkgPath(idx int) string {
+	r := pr.newDecoder(relocPkg, idx, syncPkgDef)
+	path := r.string()
+	if path == "" {
+		path = pr.pkgPath
+	}
+	return path
+}
+
+func (pr *pkgDecoder) peekObj(idx int) (string, string, codeObj) {
+	r := pr.newDecoder(relocName, idx, syncObject1)
+	r.sync(syncSym)
+	r.sync(syncPkg)
+	path := pr.peekPkgPath(r.reloc(relocPkg))
+	name := r.string()
+	assert(name != "")
+
+	tag := codeObj(r.code(syncCodeObj))
+
+	return path, name, tag
+}
diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index 4c7c9fc322f..6a2aacd3fea 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/src/cmd/compile/internal/noder/noder.go
@@ -5,9 +5,11 @@
 package noder
 
 import (
+	"errors"
 	"fmt"
 	"go/constant"
 	"go/token"
+	"internal/buildcfg"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -29,8 +31,11 @@ import (
 func LoadPackage(filenames []string) {
 	base.Timer.Start("fe", "parse")
 
+	// -G=3 and unified expect generics syntax, but -G=0 does not.
+	supportsGenerics := base.Flag.G != 0 || buildcfg.Experiment.Unified
+
 	mode := syntax.CheckBranches
-	if base.Flag.G != 0 {
+	if supportsGenerics && types.AllowsGoVersion(types.LocalPkg, 1, 18) {
 		mode |= syntax.AllowGenerics
 	}
 
@@ -75,6 +80,11 @@ func LoadPackage(filenames []string) {
 	}
 	base.Timer.AddEvent(int64(lines), "lines")
 
+	if base.Debug.Unified != 0 {
+		unified(noders)
+		return
+	}
+
 	if base.Flag.G != 0 {
 		// Use types2 to type-check and possibly generate IR.
 		check2(noders)
@@ -109,25 +119,35 @@ func LoadPackage(filenames []string) {
 	//   We also defer type alias declarations until phase 2
 	//   to avoid cycles like #18640.
 	//   TODO(gri) Remove this again once we have a fix for #25838.
-
-	// Don't use range--typecheck can add closures to Target.Decls.
-	base.Timer.Start("fe", "typecheck", "top1")
-	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		n := typecheck.Target.Decls[i]
-		if op := n.Op(); op != ir.ODCL && op != ir.OAS && op != ir.OAS2 && (op != ir.ODCLTYPE || !n.(*ir.Decl).X.Alias()) {
-			typecheck.Target.Decls[i] = typecheck.Stmt(n)
-		}
-	}
-
+	//
 	// Phase 2: Variable assignments.
 	//   To check interface assignments, depends on phase 1.
 
 	// Don't use range--typecheck can add closures to Target.Decls.
-	base.Timer.Start("fe", "typecheck", "top2")
-	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		n := typecheck.Target.Decls[i]
-		if op := n.Op(); op == ir.ODCL || op == ir.OAS || op == ir.OAS2 || op == ir.ODCLTYPE && n.(*ir.Decl).X.Alias() {
-			typecheck.Target.Decls[i] = typecheck.Stmt(n)
+	for phase, name := range []string{"top1", "top2"} {
+		base.Timer.Start("fe", "typecheck", name)
+		for i := 0; i < len(typecheck.Target.Decls); i++ {
+			n := typecheck.Target.Decls[i]
+			op := n.Op()
+
+			// Closure function declarations are typechecked as part of the
+			// closure expression.
+			if fn, ok := n.(*ir.Func); ok && fn.OClosure != nil {
+				continue
+			}
+
+			// We don't actually add ir.ODCL nodes to Target.Decls. Make sure of that.
+			if op == ir.ODCL {
+				base.FatalfAt(n.Pos(), "unexpected top declaration: %v", op)
+			}
+
+			// Identify declarations that should be deferred to the second
+			// iteration.
+			late := op == ir.OAS || op == ir.OAS2 || op == ir.ODCLTYPE && n.(*ir.Decl).X.Alias()
+
+			if late == (phase == 1) {
+				typecheck.Target.Decls[i] = typecheck.Stmt(n)
+			}
 		}
 	}
 
@@ -136,16 +156,15 @@ func LoadPackage(filenames []string) {
 	base.Timer.Start("fe", "typecheck", "func")
 	var fcount int64
 	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		n := typecheck.Target.Decls[i]
-		if n.Op() == ir.ODCLFUNC {
+		if fn, ok := typecheck.Target.Decls[i].(*ir.Func); ok {
 			if base.Flag.W > 1 {
-				s := fmt.Sprintf("\nbefore typecheck %v", n)
-				ir.Dump(s, n)
+				s := fmt.Sprintf("\nbefore typecheck %v", fn)
+				ir.Dump(s, fn)
 			}
-			typecheck.FuncBody(n.(*ir.Func))
+			typecheck.FuncBody(fn)
 			if base.Flag.W > 1 {
-				s := fmt.Sprintf("\nafter typecheck %v", n)
-				ir.Dump(s, n)
+				s := fmt.Sprintf("\nafter typecheck %v", fn)
+				ir.Dump(s, fn)
 			}
 			fcount++
 		}
@@ -449,7 +468,7 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []ir.Node {
 type constState struct {
 	group  *syntax.Group
 	typ    ir.Ntype
-	values []ir.Node
+	values syntax.Expr
 	iota   int64
 }
 
@@ -467,16 +486,15 @@ func (p *noder) constDecl(decl *syntax.ConstDecl, cs *constState) []ir.Node {
 	names := p.declNames(ir.OLITERAL, decl.NameList)
 	typ := p.typeExprOrNil(decl.Type)
 
-	var values []ir.Node
 	if decl.Values != nil {
-		values = p.exprList(decl.Values)
-		cs.typ, cs.values = typ, values
+		cs.typ, cs.values = typ, decl.Values
 	} else {
 		if typ != nil {
 			base.Errorf("const declaration cannot have type without expression")
 		}
-		typ, values = cs.typ, cs.values
+		typ = cs.typ
 	}
+	values := p.exprList(cs.values)
 
 	nn := make([]ir.Node, 0, len(names))
 	for i, n := range names {
@@ -484,10 +502,16 @@ func (p *noder) constDecl(decl *syntax.ConstDecl, cs *constState) []ir.Node {
 			base.Errorf("missing value in const declaration")
 			break
 		}
+
 		v := values[i]
 		if decl.Values == nil {
-			v = ir.DeepCopy(n.Pos(), v)
+			ir.Visit(v, func(v ir.Node) {
+				if ir.HasUniquePos(v) {
+					v.SetPos(n.Pos())
+				}
+			})
 		}
+
 		typecheck.Declare(n, typecheck.DeclContext)
 
 		n.Ntype = typ
@@ -625,6 +649,9 @@ func (p *noder) params(params []*syntax.Field, dddOk bool) []*ir.Field {
 	for i, param := range params {
 		p.setlineno(param)
 		nodes = append(nodes, p.param(param, dddOk, i+1 == len(params)))
+		if i > 0 && params[i].Type == params[i-1].Type {
+			nodes[i].Ntype = nodes[i-1].Ntype
+		}
 	}
 	return nodes
 }
@@ -882,9 +909,6 @@ func (p *noder) typeExpr(typ syntax.Expr) ir.Ntype {
 	if n == nil {
 		return nil
 	}
-	if _, ok := n.(ir.Ntype); !ok {
-		ir.Dump("NOT NTYPE", n)
-	}
 	return n.(ir.Ntype)
 }
 
@@ -917,6 +941,9 @@ func (p *noder) structType(expr *syntax.StructType) ir.Node {
 		} else {
 			n = ir.NewField(p.pos(field), p.name(field.Name), p.typeExpr(field.Type), nil)
 		}
+		if i > 0 && expr.FieldList[i].Type == expr.FieldList[i-1].Type {
+			n.Ntype = l[i-1].Ntype
+		}
 		if i < len(expr.TagList) && expr.TagList[i] != nil {
 			n.Note = constant.StringVal(p.basicLit(expr.TagList[i]))
 		}
@@ -980,6 +1007,8 @@ func (p *noder) packname(expr syntax.Expr) *types.Sym {
 }
 
 func (p *noder) embedded(typ syntax.Expr) *ir.Field {
+	pos := p.pos(syntax.StartPos(typ))
+
 	op, isStar := typ.(*syntax.Operation)
 	if isStar {
 		if op.Op != syntax.Mul || op.Y != nil {
@@ -989,11 +1018,11 @@ func (p *noder) embedded(typ syntax.Expr) *ir.Field {
 	}
 
 	sym := p.packname(typ)
-	n := ir.NewField(p.pos(typ), typecheck.Lookup(sym.Name), importName(sym).(ir.Ntype), nil)
+	n := ir.NewField(pos, typecheck.Lookup(sym.Name), importName(sym).(ir.Ntype), nil)
 	n.Embedded = true
 
 	if isStar {
-		n.Ntype = ir.NewStarExpr(p.pos(op), n.Ntype)
+		n.Ntype = ir.NewStarExpr(pos, n.Ntype)
 	}
 	return n
 }
@@ -1783,24 +1812,14 @@ func fakeRecv() *ir.Field {
 }
 
 func (p *noder) funcLit(expr *syntax.FuncLit) ir.Node {
-	xtype := p.typeExpr(expr.Type)
-
-	fn := ir.NewFunc(p.pos(expr))
-	fn.SetIsHiddenClosure(ir.CurFunc != nil)
-
-	fn.Nname = ir.NewNameAt(p.pos(expr), ir.BlankNode.Sym()) // filled in by tcClosure
-	fn.Nname.Func = fn
-	fn.Nname.Ntype = xtype
-	fn.Nname.Defn = fn
-
-	clo := ir.NewClosureExpr(p.pos(expr), fn)
-	fn.OClosure = clo
+	fn := ir.NewClosureFunc(p.pos(expr), ir.CurFunc != nil)
+	fn.Nname.Ntype = p.typeExpr(expr.Type)
 
 	p.funcBody(fn, expr.Body)
 
 	ir.FinishCaptureNames(base.Pos, ir.CurFunc, fn)
 
-	return clo
+	return fn.OClosure
 }
 
 // A function named init is a special case.
@@ -1844,33 +1863,14 @@ func oldname(s *types.Sym) ir.Node {
 }
 
 func varEmbed(makeXPos func(syntax.Pos) src.XPos, name *ir.Name, decl *syntax.VarDecl, pragma *pragmas, haveEmbed bool) {
-	if pragma.Embeds == nil {
-		return
-	}
-
 	pragmaEmbeds := pragma.Embeds
 	pragma.Embeds = nil
-	pos := makeXPos(pragmaEmbeds[0].Pos)
+	if len(pragmaEmbeds) == 0 {
+		return
+	}
 
-	if !haveEmbed {
-		base.ErrorfAt(pos, "go:embed only allowed in Go files that import \"embed\"")
-		return
-	}
-	if len(decl.NameList) > 1 {
-		base.ErrorfAt(pos, "go:embed cannot apply to multiple vars")
-		return
-	}
-	if decl.Values != nil {
-		base.ErrorfAt(pos, "go:embed cannot apply to var with initializer")
-		return
-	}
-	if decl.Type == nil {
-		// Should not happen, since Values == nil now.
-		base.ErrorfAt(pos, "go:embed cannot apply to var without type")
-		return
-	}
-	if typecheck.DeclContext != ir.PEXTERN {
-		base.ErrorfAt(pos, "go:embed cannot apply to var inside func")
+	if err := checkEmbed(decl, haveEmbed, typecheck.DeclContext != ir.PEXTERN); err != nil {
+		base.ErrorfAt(makeXPos(pragmaEmbeds[0].Pos), "%s", err)
 		return
 	}
 
@@ -1881,3 +1881,24 @@ func varEmbed(makeXPos func(syntax.Pos) src.XPos, name *ir.Name, decl *syntax.Va
 	typecheck.Target.Embeds = append(typecheck.Target.Embeds, name)
 	name.Embed = &embeds
 }
+
+func checkEmbed(decl *syntax.VarDecl, haveEmbed, withinFunc bool) error {
+	switch {
+	case !haveEmbed:
+		return errors.New("go:embed only allowed in Go files that import \"embed\"")
+	case len(decl.NameList) > 1:
+		return errors.New("go:embed cannot apply to multiple vars")
+	case decl.Values != nil:
+		return errors.New("go:embed cannot apply to var with initializer")
+	case decl.Type == nil:
+		// Should not happen, since Values == nil now.
+		return errors.New("go:embed cannot apply to var without type")
+	case withinFunc:
+		return errors.New("go:embed cannot apply to var inside func")
+	case !types.AllowsGoVersion(types.LocalPkg, 1, 16):
+		return fmt.Errorf("go:embed requires go1.16 or later (-lang was set to %s; check go.mod)", base.Flag.Lang)
+
+	default:
+		return nil
+	}
+}
diff --git a/src/cmd/compile/internal/noder/object.go b/src/cmd/compile/internal/noder/object.go
index 82cce1ace0f..40c0b9cf422 100644
--- a/src/cmd/compile/internal/noder/object.go
+++ b/src/cmd/compile/internal/noder/object.go
@@ -29,7 +29,7 @@ func (g *irgen) use(name *syntax.Name) *ir.Name {
 	if !ok {
 		base.FatalfAt(g.pos(name), "unknown name %v", name)
 	}
-	obj := ir.CaptureName(g.pos(obj2), ir.CurFunc, g.obj(obj2))
+	obj := ir.CaptureName(g.pos(name), ir.CurFunc, g.obj(obj2))
 	if obj.Defn != nil && obj.Defn.Op() == ir.ONAME {
 		// If CaptureName created a closure variable, then transfer the
 		// type of the captured name to the new closure variable.
@@ -49,6 +49,11 @@ func (g *irgen) obj(obj types2.Object) *ir.Name {
 	// For imported objects, we use iimport directly instead of mapping
 	// the types2 representation.
 	if obj.Pkg() != g.self {
+		if sig, ok := obj.Type().(*types2.Signature); ok && sig.Recv() != nil {
+			// We can't import a method by name - must import the type
+			// and access the method from it.
+			base.FatalfAt(g.pos(obj), "tried to import a method directly")
+		}
 		sym := g.sym(obj)
 		if sym.Def != nil {
 			return sym.Def.(*ir.Name)
@@ -101,25 +106,28 @@ func (g *irgen) obj(obj types2.Object) *ir.Name {
 	case *types2.TypeName:
 		if obj.IsAlias() {
 			name = g.objCommon(pos, ir.OTYPE, g.sym(obj), class, g.typ(obj.Type()))
+			name.SetAlias(true)
 		} else {
 			name = ir.NewDeclNameAt(pos, ir.OTYPE, g.sym(obj))
 			g.objFinish(name, class, types.NewNamed(name))
 		}
 
 	case *types2.Var:
-		var sym *types.Sym
-		if class == ir.PPARAMOUT {
+		sym := g.sym(obj)
+		if class == ir.PPARAMOUT && (sym == nil || sym.IsBlank()) {
 			// Backend needs names for result parameters,
 			// even if they're anonymous or blank.
-			switch obj.Name() {
-			case "":
-				sym = typecheck.LookupNum("~r", len(ir.CurFunc.Dcl)) // 'r' for "result"
-			case "_":
-				sym = typecheck.LookupNum("~b", len(ir.CurFunc.Dcl)) // 'b' for "blank"
+			nresults := 0
+			for _, n := range ir.CurFunc.Dcl {
+				if n.Class == ir.PPARAMOUT {
+					nresults++
+				}
+			}
+			if sym == nil {
+				sym = typecheck.LookupNum("~r", nresults) // 'r' for "result"
+			} else {
+				sym = typecheck.LookupNum("~b", nresults) // 'b' for "blank"
 			}
-		}
-		if sym == nil {
-			sym = g.sym(obj)
 		}
 		name = g.objCommon(pos, ir.ONAME, sym, class, g.typ(obj.Type()))
 
@@ -164,9 +172,8 @@ func (g *irgen) objFinish(name *ir.Name, class ir.Class, typ *types.Type) {
 			break // methods are exported with their receiver type
 		}
 		if types.IsExported(sym.Name) {
-			if name.Class == ir.PFUNC && name.Type().NumTParams() > 0 {
-				base.FatalfAt(name.Pos(), "Cannot export a generic function (yet): %v", name)
-			}
+			// Generic functions can be marked for export here, even
+			// though they will not be compiled until instantiated.
 			typecheck.Export(name)
 		}
 		if base.Flag.AsmHdr != "" && !name.Sym().Asm() {
diff --git a/src/cmd/compile/internal/noder/quirks.go b/src/cmd/compile/internal/noder/quirks.go
new file mode 100644
index 00000000000..914c5d2bd71
--- /dev/null
+++ b/src/cmd/compile/internal/noder/quirks.go
@@ -0,0 +1,450 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"fmt"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/syntax"
+	"cmd/compile/internal/types2"
+	"cmd/internal/src"
+)
+
+// This file defines helper functions useful for satisfying toolstash
+// -cmp when compared against the legacy frontend behavior, but can be
+// removed after that's no longer a concern.
+
+// quirksMode controls whether behavior specific to satisfying
+// toolstash -cmp is used.
+func quirksMode() bool {
+	return base.Debug.UnifiedQuirks != 0
+}
+
+// posBasesOf returns all of the position bases in the source files,
+// as seen in a straightforward traversal.
+//
+// This is necessary to ensure position bases (and thus file names)
+// get registered in the same order as noder would visit them.
+func posBasesOf(noders []*noder) []*syntax.PosBase {
+	seen := make(map[*syntax.PosBase]bool)
+	var bases []*syntax.PosBase
+
+	for _, p := range noders {
+		syntax.Crawl(p.file, func(n syntax.Node) bool {
+			if b := n.Pos().Base(); !seen[b] {
+				bases = append(bases, b)
+				seen[b] = true
+			}
+			return false
+		})
+	}
+
+	return bases
+}
+
+// importedObjsOf returns the imported objects (i.e., referenced
+// objects not declared by curpkg) from the parsed source files, in
+// the order that typecheck used to load their definitions.
+//
+// This is needed because loading the definitions for imported objects
+// can also add file names.
+func importedObjsOf(curpkg *types2.Package, info *types2.Info, noders []*noder) []types2.Object {
+	// This code is complex because it matches the precise order that
+	// typecheck recursively and repeatedly traverses the IR. It's meant
+	// to be thrown away eventually anyway.
+
+	seen := make(map[types2.Object]bool)
+	var objs []types2.Object
+
+	var phase int
+
+	decls := make(map[types2.Object]syntax.Decl)
+	assoc := func(decl syntax.Decl, names ...*syntax.Name) {
+		for _, name := range names {
+			obj, ok := info.Defs[name]
+			assert(ok)
+			decls[obj] = decl
+		}
+	}
+
+	for _, p := range noders {
+		syntax.Crawl(p.file, func(n syntax.Node) bool {
+			switch n := n.(type) {
+			case *syntax.ConstDecl:
+				assoc(n, n.NameList...)
+			case *syntax.FuncDecl:
+				assoc(n, n.Name)
+			case *syntax.TypeDecl:
+				assoc(n, n.Name)
+			case *syntax.VarDecl:
+				assoc(n, n.NameList...)
+			case *syntax.BlockStmt:
+				return true
+			}
+			return false
+		})
+	}
+
+	var visited map[syntax.Decl]bool
+
+	var resolveDecl func(n syntax.Decl)
+	var resolveNode func(n syntax.Node, top bool)
+
+	resolveDecl = func(n syntax.Decl) {
+		if visited[n] {
+			return
+		}
+		visited[n] = true
+
+		switch n := n.(type) {
+		case *syntax.ConstDecl:
+			resolveNode(n.Type, true)
+			resolveNode(n.Values, true)
+
+		case *syntax.FuncDecl:
+			if n.Recv != nil {
+				resolveNode(n.Recv, true)
+			}
+			resolveNode(n.Type, true)
+
+		case *syntax.TypeDecl:
+			resolveNode(n.Type, true)
+
+		case *syntax.VarDecl:
+			if n.Type != nil {
+				resolveNode(n.Type, true)
+			} else {
+				resolveNode(n.Values, true)
+			}
+		}
+	}
+
+	resolveObj := func(pos syntax.Pos, obj types2.Object) {
+		switch obj.Pkg() {
+		case nil:
+			// builtin; nothing to do
+
+		case curpkg:
+			if decl, ok := decls[obj]; ok {
+				resolveDecl(decl)
+			}
+
+		default:
+			if obj.Parent() == obj.Pkg().Scope() && !seen[obj] {
+				seen[obj] = true
+				objs = append(objs, obj)
+			}
+		}
+	}
+
+	checkdefat := func(pos syntax.Pos, n *syntax.Name) {
+		if n.Value == "_" {
+			return
+		}
+		obj, ok := info.Uses[n]
+		if !ok {
+			obj, ok = info.Defs[n]
+			if !ok {
+				return
+			}
+		}
+		if obj == nil {
+			return
+		}
+		resolveObj(pos, obj)
+	}
+	checkdef := func(n *syntax.Name) { checkdefat(n.Pos(), n) }
+
+	var later []syntax.Node
+
+	resolveNode = func(n syntax.Node, top bool) {
+		if n == nil {
+			return
+		}
+		syntax.Crawl(n, func(n syntax.Node) bool {
+			switch n := n.(type) {
+			case *syntax.Name:
+				checkdef(n)
+
+			case *syntax.SelectorExpr:
+				if name, ok := n.X.(*syntax.Name); ok {
+					if _, isPkg := info.Uses[name].(*types2.PkgName); isPkg {
+						checkdefat(n.X.Pos(), n.Sel)
+						return true
+					}
+				}
+
+			case *syntax.AssignStmt:
+				resolveNode(n.Rhs, top)
+				resolveNode(n.Lhs, top)
+				return true
+
+			case *syntax.VarDecl:
+				resolveNode(n.Values, top)
+
+			case *syntax.FuncLit:
+				if top {
+					resolveNode(n.Type, top)
+					later = append(later, n.Body)
+					return true
+				}
+
+			case *syntax.BlockStmt:
+				if phase >= 3 {
+					for _, stmt := range n.List {
+						resolveNode(stmt, false)
+					}
+				}
+				return true
+			}
+
+			return false
+		})
+	}
+
+	for phase = 1; phase <= 5; phase++ {
+		visited = map[syntax.Decl]bool{}
+
+		for _, p := range noders {
+			for _, decl := range p.file.DeclList {
+				switch decl := decl.(type) {
+				case *syntax.ConstDecl:
+					resolveDecl(decl)
+
+				case *syntax.FuncDecl:
+					resolveDecl(decl)
+					if phase >= 3 && decl.Body != nil {
+						resolveNode(decl.Body, true)
+					}
+
+				case *syntax.TypeDecl:
+					if !decl.Alias || phase >= 2 {
+						resolveDecl(decl)
+					}
+
+				case *syntax.VarDecl:
+					if phase >= 2 {
+						resolveNode(decl.Values, true)
+						resolveDecl(decl)
+					}
+				}
+			}
+
+			if phase >= 5 {
+				syntax.Crawl(p.file, func(n syntax.Node) bool {
+					if name, ok := n.(*syntax.Name); ok {
+						if obj, ok := info.Uses[name]; ok {
+							resolveObj(name.Pos(), obj)
+						}
+					}
+					return false
+				})
+			}
+		}
+
+		for i := 0; i < len(later); i++ {
+			resolveNode(later[i], true)
+		}
+		later = nil
+	}
+
+	return objs
+}
+
+// typeExprEndPos returns the position that noder would leave base.Pos
+// after parsing the given type expression.
+func typeExprEndPos(expr0 syntax.Expr) syntax.Pos {
+	for {
+		switch expr := expr0.(type) {
+		case *syntax.Name:
+			return expr.Pos()
+		case *syntax.SelectorExpr:
+			return expr.X.Pos()
+
+		case *syntax.ParenExpr:
+			expr0 = expr.X
+
+		case *syntax.Operation:
+			assert(expr.Op == syntax.Mul)
+			assert(expr.Y == nil)
+			expr0 = expr.X
+
+		case *syntax.ArrayType:
+			expr0 = expr.Elem
+		case *syntax.ChanType:
+			expr0 = expr.Elem
+		case *syntax.DotsType:
+			expr0 = expr.Elem
+		case *syntax.MapType:
+			expr0 = expr.Value
+		case *syntax.SliceType:
+			expr0 = expr.Elem
+
+		case *syntax.StructType:
+			return expr.Pos()
+
+		case *syntax.InterfaceType:
+			expr0 = lastFieldType(expr.MethodList)
+			if expr0 == nil {
+				return expr.Pos()
+			}
+
+		case *syntax.FuncType:
+			expr0 = lastFieldType(expr.ResultList)
+			if expr0 == nil {
+				expr0 = lastFieldType(expr.ParamList)
+				if expr0 == nil {
+					return expr.Pos()
+				}
+			}
+
+		case *syntax.IndexExpr: // explicit type instantiation
+			targs := unpackListExpr(expr.Index)
+			expr0 = targs[len(targs)-1]
+
+		default:
+			panic(fmt.Sprintf("%s: unexpected type expression %v", expr.Pos(), syntax.String(expr)))
+		}
+	}
+}
+
+func lastFieldType(fields []*syntax.Field) syntax.Expr {
+	if len(fields) == 0 {
+		return nil
+	}
+	return fields[len(fields)-1].Type
+}
+
+// sumPos returns the position that noder.sum would produce for
+// constant expression x.
+func sumPos(x syntax.Expr) syntax.Pos {
+	orig := x
+	for {
+		switch x1 := x.(type) {
+		case *syntax.BasicLit:
+			assert(x1.Kind == syntax.StringLit)
+			return x1.Pos()
+		case *syntax.Operation:
+			assert(x1.Op == syntax.Add && x1.Y != nil)
+			if r, ok := x1.Y.(*syntax.BasicLit); ok {
+				assert(r.Kind == syntax.StringLit)
+				x = x1.X
+				continue
+			}
+		}
+		return orig.Pos()
+	}
+}
+
+// funcParamsEndPos returns the value of base.Pos left by noder after
+// processing a function signature.
+func funcParamsEndPos(fn *ir.Func) src.XPos {
+	sig := fn.Nname.Type()
+
+	fields := sig.Results().FieldSlice()
+	if len(fields) == 0 {
+		fields = sig.Params().FieldSlice()
+		if len(fields) == 0 {
+			fields = sig.Recvs().FieldSlice()
+			if len(fields) == 0 {
+				if fn.OClosure != nil {
+					return fn.Nname.Ntype.Pos()
+				}
+				return fn.Pos()
+			}
+		}
+	}
+
+	return fields[len(fields)-1].Pos
+}
+
+type dupTypes struct {
+	origs map[types2.Type]types2.Type
+}
+
+func (d *dupTypes) orig(t types2.Type) types2.Type {
+	if orig, ok := d.origs[t]; ok {
+		return orig
+	}
+	return t
+}
+
+func (d *dupTypes) add(t, orig types2.Type) {
+	if t == orig {
+		return
+	}
+
+	if d.origs == nil {
+		d.origs = make(map[types2.Type]types2.Type)
+	}
+	assert(d.origs[t] == nil)
+	d.origs[t] = orig
+
+	switch t := t.(type) {
+	case *types2.Pointer:
+		orig := orig.(*types2.Pointer)
+		d.add(t.Elem(), orig.Elem())
+
+	case *types2.Slice:
+		orig := orig.(*types2.Slice)
+		d.add(t.Elem(), orig.Elem())
+
+	case *types2.Map:
+		orig := orig.(*types2.Map)
+		d.add(t.Key(), orig.Key())
+		d.add(t.Elem(), orig.Elem())
+
+	case *types2.Array:
+		orig := orig.(*types2.Array)
+		assert(t.Len() == orig.Len())
+		d.add(t.Elem(), orig.Elem())
+
+	case *types2.Chan:
+		orig := orig.(*types2.Chan)
+		assert(t.Dir() == orig.Dir())
+		d.add(t.Elem(), orig.Elem())
+
+	case *types2.Struct:
+		orig := orig.(*types2.Struct)
+		assert(t.NumFields() == orig.NumFields())
+		for i := 0; i < t.NumFields(); i++ {
+			d.add(t.Field(i).Type(), orig.Field(i).Type())
+		}
+
+	case *types2.Interface:
+		orig := orig.(*types2.Interface)
+		assert(t.NumExplicitMethods() == orig.NumExplicitMethods())
+		assert(t.NumEmbeddeds() == orig.NumEmbeddeds())
+		for i := 0; i < t.NumExplicitMethods(); i++ {
+			d.add(t.ExplicitMethod(i).Type(), orig.ExplicitMethod(i).Type())
+		}
+		for i := 0; i < t.NumEmbeddeds(); i++ {
+			d.add(t.EmbeddedType(i), orig.EmbeddedType(i))
+		}
+
+	case *types2.Signature:
+		orig := orig.(*types2.Signature)
+		assert((t.Recv() == nil) == (orig.Recv() == nil))
+		if t.Recv() != nil {
+			d.add(t.Recv().Type(), orig.Recv().Type())
+		}
+		d.add(t.Params(), orig.Params())
+		d.add(t.Results(), orig.Results())
+
+	case *types2.Tuple:
+		orig := orig.(*types2.Tuple)
+		assert(t.Len() == orig.Len())
+		for i := 0; i < t.Len(); i++ {
+			d.add(t.At(i).Type(), orig.At(i).Type())
+		}
+
+	default:
+		assert(types2.Identical(t, orig))
+	}
+}
diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go
new file mode 100644
index 00000000000..5481812b18d
--- /dev/null
+++ b/src/cmd/compile/internal/noder/reader.go
@@ -0,0 +1,2390 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"bytes"
+	"fmt"
+	"go/constant"
+	"strings"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/deadcode"
+	"cmd/compile/internal/dwarfgen"
+	"cmd/compile/internal/inline"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/reflectdata"
+	"cmd/compile/internal/typecheck"
+	"cmd/compile/internal/types"
+	"cmd/internal/obj"
+	"cmd/internal/src"
+)
+
+// TODO(mdempsky): Suppress duplicate type/const errors that can arise
+// during typecheck due to naive type substitution (e.g., see #42758).
+// I anticipate these will be handled as a consequence of adding
+// dictionaries support, so it's probably not important to focus on
+// this until after that's done.
+
+type pkgReader struct {
+	pkgDecoder
+
+	posBases []*src.PosBase
+	pkgs     []*types.Pkg
+	typs     []*types.Type
+
+	// offset for rewriting the given index into the output,
+	// but bitwise inverted so we can detect if we're missing the entry or not.
+	newindex []int
+}
+
+func newPkgReader(pr pkgDecoder) *pkgReader {
+	return &pkgReader{
+		pkgDecoder: pr,
+
+		posBases: make([]*src.PosBase, pr.numElems(relocPosBase)),
+		pkgs:     make([]*types.Pkg, pr.numElems(relocPkg)),
+		typs:     make([]*types.Type, pr.numElems(relocType)),
+
+		newindex: make([]int, pr.totalElems()),
+	}
+}
+
+type pkgReaderIndex struct {
+	pr   *pkgReader
+	idx  int
+	dict *readerDict
+}
+
+func (pri pkgReaderIndex) asReader(k reloc, marker syncMarker) *reader {
+	r := pri.pr.newReader(k, pri.idx, marker)
+	r.dict = pri.dict
+	return r
+}
+
+func (pr *pkgReader) newReader(k reloc, idx int, marker syncMarker) *reader {
+	return &reader{
+		decoder: pr.newDecoder(k, idx, marker),
+		p:       pr,
+	}
+}
+
+type reader struct {
+	decoder
+
+	p *pkgReader
+
+	ext *reader
+
+	dict *readerDict
+
+	// TODO(mdempsky): The state below is all specific to reading
+	// function bodies. It probably makes sense to split it out
+	// separately so that it doesn't take up space in every reader
+	// instance.
+
+	curfn       *ir.Func
+	locals      []*ir.Name
+	closureVars []*ir.Name
+
+	funarghack bool
+
+	// scopeVars is a stack tracking the number of variables declared in
+	// the current function at the moment each open scope was opened.
+	scopeVars         []int
+	marker            dwarfgen.ScopeMarker
+	lastCloseScopePos src.XPos
+
+	// === details for handling inline body expansion ===
+
+	// If we're reading in a function body because of inlining, this is
+	// the call that we're inlining for.
+	inlCaller    *ir.Func
+	inlCall      *ir.CallExpr
+	inlFunc      *ir.Func
+	inlTreeIndex int
+	inlPosBases  map[*src.PosBase]*src.PosBase
+
+	delayResults bool
+
+	// Label to return to.
+	retlabel *types.Sym
+
+	inlvars, retvars ir.Nodes
+}
+
+type readerDict struct {
+	// targs holds the implicit and explicit type arguments in use for
+	// reading the current object. For example:
+	//
+	//	func F[T any]() {
+	//		type X[U any] struct { t T; u U }
+	//		var _ X[string]
+	//	}
+	//
+	//	var _ = F[int]
+	//
+	// While instantiating F[int], we need to in turn instantiate
+	// X[string]. [int] and [string] are explicit type arguments for F
+	// and X, respectively; but [int] is also the implicit type
+	// arguments for X.
+	//
+	// (As an analogy to function literals, explicits are the function
+	// literal's formal parameters, while implicits are variables
+	// captured by the function literal.)
+	targs []*types.Type
+
+	// implicits counts how many of types within targs are implicit type
+	// arguments; the rest are explicit.
+	implicits int
+
+	derived      []derivedInfo // reloc index of the derived type's descriptor
+	derivedTypes []*types.Type // slice of previously computed derived types
+
+	funcs    []objInfo
+	funcsObj []ir.Node
+}
+
+func (r *reader) setType(n ir.Node, typ *types.Type) {
+	n.SetType(typ)
+	n.SetTypecheck(1)
+
+	if name, ok := n.(*ir.Name); ok {
+		name.SetWalkdef(1)
+		name.Ntype = ir.TypeNode(name.Type())
+	}
+}
+
+func (r *reader) setValue(name *ir.Name, val constant.Value) {
+	name.SetVal(val)
+	name.Defn = nil
+}
+
+// @@@ Positions
+
+func (r *reader) pos() src.XPos {
+	return base.Ctxt.PosTable.XPos(r.pos0())
+}
+
+func (r *reader) pos0() src.Pos {
+	r.sync(syncPos)
+	if !r.bool() {
+		return src.NoPos
+	}
+
+	posBase := r.posBase()
+	line := r.uint()
+	col := r.uint()
+	return src.MakePos(posBase, line, col)
+}
+
+func (r *reader) posBase() *src.PosBase {
+	return r.inlPosBase(r.p.posBaseIdx(r.reloc(relocPosBase)))
+}
+
+func (pr *pkgReader) posBaseIdx(idx int) *src.PosBase {
+	if b := pr.posBases[idx]; b != nil {
+		return b
+	}
+
+	r := pr.newReader(relocPosBase, idx, syncPosBase)
+	var b *src.PosBase
+
+	fn := r.string()
+	absfn := r.string()
+
+	if r.bool() {
+		b = src.NewFileBase(fn, absfn)
+	} else {
+		pos := r.pos0()
+		line := r.uint()
+		col := r.uint()
+		b = src.NewLinePragmaBase(pos, fn, absfn, line, col)
+	}
+
+	pr.posBases[idx] = b
+	return b
+}
+
+func (r *reader) inlPosBase(oldBase *src.PosBase) *src.PosBase {
+	if r.inlCall == nil {
+		return oldBase
+	}
+
+	if newBase, ok := r.inlPosBases[oldBase]; ok {
+		return newBase
+	}
+
+	newBase := src.NewInliningBase(oldBase, r.inlTreeIndex)
+	r.inlPosBases[oldBase] = newBase
+	return newBase
+}
+
+func (r *reader) updatePos(xpos src.XPos) src.XPos {
+	pos := base.Ctxt.PosTable.Pos(xpos)
+	pos.SetBase(r.inlPosBase(pos.Base()))
+	return base.Ctxt.PosTable.XPos(pos)
+}
+
+func (r *reader) origPos(xpos src.XPos) src.XPos {
+	if r.inlCall == nil {
+		return xpos
+	}
+
+	pos := base.Ctxt.PosTable.Pos(xpos)
+	for old, new := range r.inlPosBases {
+		if pos.Base() == new {
+			pos.SetBase(old)
+			return base.Ctxt.PosTable.XPos(pos)
+		}
+	}
+
+	base.FatalfAt(xpos, "pos base missing from inlPosBases")
+	panic("unreachable")
+}
+
+// @@@ Packages
+
+func (r *reader) pkg() *types.Pkg {
+	r.sync(syncPkg)
+	return r.p.pkgIdx(r.reloc(relocPkg))
+}
+
+func (pr *pkgReader) pkgIdx(idx int) *types.Pkg {
+	if pkg := pr.pkgs[idx]; pkg != nil {
+		return pkg
+	}
+
+	pkg := pr.newReader(relocPkg, idx, syncPkgDef).doPkg()
+	pr.pkgs[idx] = pkg
+	return pkg
+}
+
+func (r *reader) doPkg() *types.Pkg {
+	path := r.string()
+	if path == "builtin" {
+		return types.BuiltinPkg
+	}
+	if path == "" {
+		path = r.p.pkgPath
+	}
+
+	name := r.string()
+	height := r.len()
+
+	pkg := types.NewPkg(path, "")
+
+	if pkg.Name == "" {
+		pkg.Name = name
+	} else {
+		assert(pkg.Name == name)
+	}
+
+	if pkg.Height == 0 {
+		pkg.Height = height
+	} else {
+		assert(pkg.Height == height)
+	}
+
+	return pkg
+}
+
+// @@@ Types
+
+func (r *reader) typ() *types.Type {
+	return r.p.typIdx(r.typInfo(), r.dict)
+}
+
+func (r *reader) typInfo() typeInfo {
+	r.sync(syncType)
+	if r.bool() {
+		return typeInfo{idx: r.len(), derived: true}
+	}
+	return typeInfo{idx: r.reloc(relocType), derived: false}
+}
+
+func (pr *pkgReader) typIdx(info typeInfo, dict *readerDict) *types.Type {
+	idx := info.idx
+	var where **types.Type
+	if info.derived {
+		where = &dict.derivedTypes[idx]
+		idx = dict.derived[idx].idx
+	} else {
+		where = &pr.typs[idx]
+	}
+
+	if typ := *where; typ != nil {
+		return typ
+	}
+
+	r := pr.newReader(relocType, idx, syncTypeIdx)
+	r.dict = dict
+
+	typ := r.doTyp()
+	assert(typ != nil)
+
+	// For recursive type declarations involving interfaces and aliases,
+	// above r.doTyp() call may have already set pr.typs[idx], so just
+	// double check and return the type.
+	//
+	// Example:
+	//
+	//     type F = func(I)
+	//
+	//     type I interface {
+	//         m(F)
+	//     }
+	//
+	// The writer writes data types in following index order:
+	//
+	//     0: func(I)
+	//     1: I
+	//     2: interface{m(func(I))}
+	//
+	// The reader resolves it in following index order:
+	//
+	//     0 -> 1 -> 2 -> 0 -> 1
+	//
+	// and can divide in logically 2 steps:
+	//
+	//  - 0 -> 1     : first time the reader reach type I,
+	//                 it creates new named type with symbol I.
+	//
+	//  - 2 -> 0 -> 1: the reader ends up reaching symbol I again,
+	//                 now the symbol I was setup in above step, so
+	//                 the reader just return the named type.
+	//
+	// Now, the functions called return, the pr.typs looks like below:
+	//
+	//  - 0 -> 1 -> 2 -> 0 : [ I ]
+	//  - 0 -> 1 -> 2      : [func(I) I ]
+	//  - 0 -> 1           : [func(I) I interface { "".m(func("".I)) }]
+	//
+	// The idx 1, corresponding with type I was resolved successfully
+	// after r.doTyp() call.
+
+	if prev := *where; prev != nil {
+		return prev
+	}
+
+	*where = typ
+
+	if !typ.IsUntyped() {
+		types.CheckSize(typ)
+	}
+
+	return typ
+}
+
+func (r *reader) doTyp() *types.Type {
+	switch tag := codeType(r.code(syncType)); tag {
+	default:
+		panic(fmt.Sprintf("unexpected type: %v", tag))
+
+	case typeBasic:
+		return *basics[r.len()]
+
+	case typeNamed:
+		obj := r.obj()
+		assert(obj.Op() == ir.OTYPE)
+		return obj.Type()
+
+	case typeTypeParam:
+		return r.dict.targs[r.len()]
+
+	case typeArray:
+		len := int64(r.uint64())
+		return types.NewArray(r.typ(), len)
+	case typeChan:
+		dir := dirs[r.len()]
+		return types.NewChan(r.typ(), dir)
+	case typeMap:
+		return types.NewMap(r.typ(), r.typ())
+	case typePointer:
+		return types.NewPtr(r.typ())
+	case typeSignature:
+		return r.signature(types.LocalPkg, nil)
+	case typeSlice:
+		return types.NewSlice(r.typ())
+	case typeStruct:
+		return r.structType()
+	case typeInterface:
+		return r.interfaceType()
+	}
+}
+
+func (r *reader) interfaceType() *types.Type {
+	tpkg := types.LocalPkg // TODO(mdempsky): Remove after iexport is gone.
+
+	nmethods, nembeddeds := r.len(), r.len()
+
+	fields := make([]*types.Field, nmethods+nembeddeds)
+	methods, embeddeds := fields[:nmethods], fields[nmethods:]
+
+	for i := range methods {
+		pos := r.pos()
+		pkg, sym := r.selector()
+		tpkg = pkg
+		mtyp := r.signature(pkg, typecheck.FakeRecv())
+		methods[i] = types.NewField(pos, sym, mtyp)
+	}
+	for i := range embeddeds {
+		embeddeds[i] = types.NewField(src.NoXPos, nil, r.typ())
+	}
+
+	if len(fields) == 0 {
+		return types.Types[types.TINTER] // empty interface
+	}
+	return r.needWrapper(types.NewInterface(tpkg, fields))
+}
+
+func (r *reader) structType() *types.Type {
+	tpkg := types.LocalPkg // TODO(mdempsky): Remove after iexport is gone.
+	fields := make([]*types.Field, r.len())
+	for i := range fields {
+		pos := r.pos()
+		pkg, sym := r.selector()
+		tpkg = pkg
+		ftyp := r.typ()
+		tag := r.string()
+		embedded := r.bool()
+
+		f := types.NewField(pos, sym, ftyp)
+		f.Note = tag
+		if embedded {
+			f.Embedded = 1
+		}
+		fields[i] = f
+	}
+	return r.needWrapper(types.NewStruct(tpkg, fields))
+}
+
+func (r *reader) signature(tpkg *types.Pkg, recv *types.Field) *types.Type {
+	r.sync(syncSignature)
+
+	params := r.params(&tpkg)
+	results := r.params(&tpkg)
+	if r.bool() { // variadic
+		params[len(params)-1].SetIsDDD(true)
+	}
+
+	return types.NewSignature(tpkg, recv, nil, params, results)
+}
+
+func (r *reader) params(tpkg **types.Pkg) []*types.Field {
+	r.sync(syncParams)
+	fields := make([]*types.Field, r.len())
+	for i := range fields {
+		*tpkg, fields[i] = r.param()
+	}
+	return fields
+}
+
+func (r *reader) param() (*types.Pkg, *types.Field) {
+	r.sync(syncParam)
+
+	pos := r.pos()
+	pkg, sym := r.localIdent()
+	typ := r.typ()
+
+	return pkg, types.NewField(pos, sym, typ)
+}
+
+// @@@ Objects
+
+var objReader = map[*types.Sym]pkgReaderIndex{}
+
+func (r *reader) obj() ir.Node {
+	r.sync(syncObject)
+
+	if r.bool() {
+		idx := r.len()
+		obj := r.dict.funcsObj[idx]
+		if obj == nil {
+			fn := r.dict.funcs[idx]
+			targs := make([]*types.Type, len(fn.explicits))
+			for i, targ := range fn.explicits {
+				targs[i] = r.p.typIdx(targ, r.dict)
+			}
+
+			obj = r.p.objIdx(fn.idx, nil, targs)
+			assert(r.dict.funcsObj[idx] == nil)
+			r.dict.funcsObj[idx] = obj
+		}
+		return obj
+	}
+
+	idx := r.reloc(relocObj)
+
+	explicits := make([]*types.Type, r.len())
+	for i := range explicits {
+		explicits[i] = r.typ()
+	}
+
+	var implicits []*types.Type
+	if r.dict != nil {
+		implicits = r.dict.targs
+	}
+
+	return r.p.objIdx(idx, implicits, explicits)
+}
+
+func (pr *pkgReader) objIdx(idx int, implicits, explicits []*types.Type) ir.Node {
+	rname := pr.newReader(relocName, idx, syncObject1)
+	_, sym := rname.qualifiedIdent()
+	tag := codeObj(rname.code(syncCodeObj))
+
+	if tag == objStub {
+		assert(!sym.IsBlank())
+		switch sym.Pkg {
+		case types.BuiltinPkg, ir.Pkgs.Unsafe:
+			return sym.Def.(ir.Node)
+		}
+		if pri, ok := objReader[sym]; ok {
+			return pri.pr.objIdx(pri.idx, nil, explicits)
+		}
+		if haveLegacyImports {
+			assert(len(explicits) == 0)
+			return typecheck.Resolve(ir.NewIdent(src.NoXPos, sym))
+		}
+		base.Fatalf("unresolved stub: %v", sym)
+	}
+
+	dict := pr.objDictIdx(sym, idx, implicits, explicits)
+
+	r := pr.newReader(relocObj, idx, syncObject1)
+	r.ext = pr.newReader(relocObjExt, idx, syncObject1)
+
+	r.dict = dict
+	r.ext.dict = dict
+
+	sym = r.mangle(sym)
+	if !sym.IsBlank() && sym.Def != nil {
+		return sym.Def.(*ir.Name)
+	}
+
+	do := func(op ir.Op, hasTParams bool) *ir.Name {
+		pos := r.pos()
+		if hasTParams {
+			r.typeParamNames()
+		}
+
+		name := ir.NewDeclNameAt(pos, op, sym)
+		name.Class = ir.PEXTERN // may be overridden later
+		if !sym.IsBlank() {
+			if sym.Def != nil {
+				base.FatalfAt(name.Pos(), "already have a definition for %v", name)
+			}
+			assert(sym.Def == nil)
+			sym.Def = name
+		}
+		return name
+	}
+
+	switch tag {
+	default:
+		panic("unexpected object")
+
+	case objAlias:
+		name := do(ir.OTYPE, false)
+		r.setType(name, r.typ())
+		name.SetAlias(true)
+		return name
+
+	case objConst:
+		name := do(ir.OLITERAL, false)
+		typ, val := r.value()
+		r.setType(name, typ)
+		r.setValue(name, val)
+		return name
+
+	case objFunc:
+		if sym.Name == "init" {
+			sym = renameinit()
+		}
+		name := do(ir.ONAME, true)
+		r.setType(name, r.signature(sym.Pkg, nil))
+
+		name.Func = ir.NewFunc(r.pos())
+		name.Func.Nname = name
+
+		r.ext.funcExt(name)
+		return name
+
+	case objType:
+		name := do(ir.OTYPE, true)
+		typ := types.NewNamed(name)
+		r.setType(name, typ)
+
+		// Important: We need to do this before SetUnderlying.
+		r.ext.typeExt(name)
+
+		// We need to defer CheckSize until we've called SetUnderlying to
+		// handle recursive types.
+		types.DeferCheckSize()
+		typ.SetUnderlying(r.typ())
+		types.ResumeCheckSize()
+
+		methods := make([]*types.Field, r.len())
+		for i := range methods {
+			methods[i] = r.method()
+		}
+		if len(methods) != 0 {
+			typ.Methods().Set(methods)
+		}
+
+		if !typ.IsPtr() {
+			r.needWrapper(typ)
+		}
+
+		return name
+
+	case objVar:
+		name := do(ir.ONAME, false)
+		r.setType(name, r.typ())
+		r.ext.varExt(name)
+		return name
+	}
+}
+
+func (r *reader) mangle(sym *types.Sym) *types.Sym {
+	if !r.hasTypeParams() {
+		return sym
+	}
+
+	var buf bytes.Buffer
+	buf.WriteString(sym.Name)
+	buf.WriteByte('[')
+	for i, targ := range r.dict.targs {
+		if i > 0 {
+			if i == r.dict.implicits {
+				buf.WriteByte(';')
+			} else {
+				buf.WriteByte(',')
+			}
+		}
+		buf.WriteString(targ.LinkString())
+	}
+	buf.WriteByte(']')
+	return sym.Pkg.Lookup(buf.String())
+}
+
+func (pr *pkgReader) objDictIdx(sym *types.Sym, idx int, implicits, explicits []*types.Type) *readerDict {
+	r := pr.newReader(relocObjDict, idx, syncObject1)
+
+	var dict readerDict
+
+	nimplicits := r.len()
+	nexplicits := r.len()
+
+	if nimplicits > len(implicits) || nexplicits != len(explicits) {
+		base.Fatalf("%v has %v+%v params, but instantiated with %v+%v args", sym, nimplicits, nexplicits, len(implicits), len(explicits))
+	}
+
+	dict.targs = append(implicits[:nimplicits:nimplicits], explicits...)
+	dict.implicits = nimplicits
+
+	// For stenciling, we can just skip over the type parameters.
+	for range dict.targs[dict.implicits:] {
+		// Skip past bounds without actually evaluating them.
+		r.sync(syncType)
+		if r.bool() {
+			r.len()
+		} else {
+			r.reloc(relocType)
+		}
+	}
+
+	dict.derived = make([]derivedInfo, r.len())
+	dict.derivedTypes = make([]*types.Type, len(dict.derived))
+	for i := range dict.derived {
+		dict.derived[i] = derivedInfo{r.reloc(relocType), r.bool()}
+	}
+
+	dict.funcs = make([]objInfo, r.len())
+	dict.funcsObj = make([]ir.Node, len(dict.funcs))
+	for i := range dict.funcs {
+		objIdx := r.reloc(relocObj)
+		targs := make([]typeInfo, r.len())
+		for j := range targs {
+			targs[j] = r.typInfo()
+		}
+		dict.funcs[i] = objInfo{idx: objIdx, explicits: targs}
+	}
+
+	return &dict
+}
+
+func (r *reader) typeParamNames() {
+	r.sync(syncTypeParamNames)
+
+	for range r.dict.targs[r.dict.implicits:] {
+		r.pos()
+		r.localIdent()
+	}
+}
+
+func (r *reader) value() (*types.Type, constant.Value) {
+	r.sync(syncValue)
+	typ := r.typ()
+	return typ, FixValue(typ, r.rawValue())
+}
+
+func (r *reader) method() *types.Field {
+	r.sync(syncMethod)
+	pos := r.pos()
+	pkg, sym := r.selector()
+	r.typeParamNames()
+	_, recv := r.param()
+	typ := r.signature(pkg, recv)
+
+	fnsym := sym
+	fnsym = ir.MethodSym(recv.Type, fnsym)
+	name := ir.NewNameAt(pos, fnsym)
+	r.setType(name, typ)
+
+	name.Func = ir.NewFunc(r.pos())
+	name.Func.Nname = name
+
+	r.ext.funcExt(name)
+
+	meth := types.NewField(name.Func.Pos(), sym, typ)
+	meth.Nname = name
+	meth.SetNointerface(name.Func.Pragma&ir.Nointerface != 0)
+
+	return meth
+}
+
+func (r *reader) qualifiedIdent() (pkg *types.Pkg, sym *types.Sym) {
+	r.sync(syncSym)
+	pkg = r.pkg()
+	if name := r.string(); name != "" {
+		sym = pkg.Lookup(name)
+	}
+	return
+}
+
+func (r *reader) localIdent() (pkg *types.Pkg, sym *types.Sym) {
+	r.sync(syncLocalIdent)
+	pkg = r.pkg()
+	if name := r.string(); name != "" {
+		sym = pkg.Lookup(name)
+	}
+	return
+}
+
+func (r *reader) selector() (origPkg *types.Pkg, sym *types.Sym) {
+	r.sync(syncSelector)
+	origPkg = r.pkg()
+	name := r.string()
+	pkg := origPkg
+	if types.IsExported(name) {
+		pkg = types.LocalPkg
+	}
+	sym = pkg.Lookup(name)
+	return
+}
+
+func (r *reader) hasTypeParams() bool {
+	return r.dict.hasTypeParams()
+}
+
+func (dict *readerDict) hasTypeParams() bool {
+	return dict != nil && len(dict.targs) != 0
+}
+
+// @@@ Compiler extensions
+
+func (r *reader) funcExt(name *ir.Name) {
+	r.sync(syncFuncExt)
+
+	name.Class = 0 // so MarkFunc doesn't complain
+	ir.MarkFunc(name)
+
+	fn := name.Func
+
+	// XXX: Workaround because linker doesn't know how to copy Pos.
+	if !fn.Pos().IsKnown() {
+		fn.SetPos(name.Pos())
+	}
+
+	// Normally, we only compile local functions, which saves redundant compilation work.
+	// n.Defn is not nil for local functions, and is nil for imported function. But for
+	// generic functions, we might have an instantiation that no other package has seen before.
+	// So we need to be conservative and compile it again.
+	//
+	// That's why name.Defn is set here, so ir.VisitFuncsBottomUp can analyze function.
+	// TODO(mdempsky,cuonglm): find a cleaner way to handle this.
+	if name.Sym().Pkg == types.LocalPkg || r.hasTypeParams() {
+		name.Defn = fn
+	}
+
+	fn.Pragma = r.pragmaFlag()
+	r.linkname(name)
+
+	typecheck.Func(fn)
+
+	if r.bool() {
+		fn.ABI = obj.ABI(r.uint64())
+
+		// Escape analysis.
+		for _, fs := range &types.RecvsParams {
+			for _, f := range fs(name.Type()).FieldSlice() {
+				f.Note = r.string()
+			}
+		}
+
+		if r.bool() {
+			fn.Inl = &ir.Inline{
+				Cost:            int32(r.len()),
+				CanDelayResults: r.bool(),
+			}
+			r.addBody(name.Func)
+		}
+	} else {
+		r.addBody(name.Func)
+	}
+	r.sync(syncEOF)
+}
+
+func (r *reader) typeExt(name *ir.Name) {
+	r.sync(syncTypeExt)
+
+	typ := name.Type()
+
+	if r.hasTypeParams() {
+		// Set "RParams" (really type arguments here, not parameters) so
+		// this type is treated as "fully instantiated". This ensures the
+		// type descriptor is written out as DUPOK and method wrappers are
+		// generated even for imported types.
+		var targs []*types.Type
+		targs = append(targs, r.dict.targs...)
+		typ.SetRParams(targs)
+	}
+
+	name.SetPragma(r.pragmaFlag())
+	if name.Pragma()&ir.NotInHeap != 0 {
+		typ.SetNotInHeap(true)
+	}
+
+	typecheck.SetBaseTypeIndex(typ, r.int64(), r.int64())
+}
+
+func (r *reader) varExt(name *ir.Name) {
+	r.sync(syncVarExt)
+	r.linkname(name)
+}
+
+func (r *reader) linkname(name *ir.Name) {
+	assert(name.Op() == ir.ONAME)
+	r.sync(syncLinkname)
+
+	if idx := r.int64(); idx >= 0 {
+		lsym := name.Linksym()
+		lsym.SymIdx = int32(idx)
+		lsym.Set(obj.AttrIndexed, true)
+	} else {
+		name.Sym().Linkname = r.string()
+	}
+}
+
+func (r *reader) pragmaFlag() ir.PragmaFlag {
+	r.sync(syncPragma)
+	return ir.PragmaFlag(r.int())
+}
+
+// @@@ Function bodies
+
+// bodyReader tracks where the serialized IR for a function's body can
+// be found.
+var bodyReader = map[*ir.Func]pkgReaderIndex{}
+
+// todoBodies holds the list of function bodies that still need to be
+// constructed.
+var todoBodies []*ir.Func
+
+func (r *reader) addBody(fn *ir.Func) {
+	pri := pkgReaderIndex{r.p, r.reloc(relocBody), r.dict}
+	bodyReader[fn] = pri
+
+	if r.curfn == nil {
+		todoBodies = append(todoBodies, fn)
+		return
+	}
+
+	pri.funcBody(fn)
+}
+
+func (pri pkgReaderIndex) funcBody(fn *ir.Func) {
+	r := pri.asReader(relocBody, syncFuncBody)
+	r.funcBody(fn)
+}
+
+func (r *reader) funcBody(fn *ir.Func) {
+	r.curfn = fn
+	r.closureVars = fn.ClosureVars
+
+	ir.WithFunc(fn, func() {
+		r.funcargs(fn)
+
+		if !r.bool() {
+			return
+		}
+
+		body := r.stmts()
+		if body == nil {
+			pos := src.NoXPos
+			if quirksMode() {
+				pos = funcParamsEndPos(fn)
+			}
+			body = []ir.Node{typecheck.Stmt(ir.NewBlockStmt(pos, nil))}
+		}
+		fn.Body = body
+		fn.Endlineno = r.pos()
+	})
+
+	r.marker.WriteTo(fn)
+}
+
+func (r *reader) funcargs(fn *ir.Func) {
+	sig := fn.Nname.Type()
+
+	if recv := sig.Recv(); recv != nil {
+		r.funcarg(recv, recv.Sym, ir.PPARAM)
+	}
+	for _, param := range sig.Params().FieldSlice() {
+		r.funcarg(param, param.Sym, ir.PPARAM)
+	}
+
+	for i, param := range sig.Results().FieldSlice() {
+		sym := types.OrigSym(param.Sym)
+
+		if sym == nil || sym.IsBlank() {
+			prefix := "~r"
+			if r.inlCall != nil {
+				prefix = "~R"
+			} else if sym != nil {
+				prefix = "~b"
+			}
+			sym = typecheck.LookupNum(prefix, i)
+		}
+
+		r.funcarg(param, sym, ir.PPARAMOUT)
+	}
+}
+
+func (r *reader) funcarg(param *types.Field, sym *types.Sym, ctxt ir.Class) {
+	if sym == nil {
+		assert(ctxt == ir.PPARAM)
+		if r.inlCall != nil {
+			r.inlvars.Append(ir.BlankNode)
+		}
+		return
+	}
+
+	name := ir.NewNameAt(r.updatePos(param.Pos), sym)
+	r.setType(name, param.Type)
+	r.addLocal(name, ctxt)
+
+	if r.inlCall == nil {
+		if !r.funarghack {
+			param.Sym = sym
+			param.Nname = name
+		}
+	} else {
+		if ctxt == ir.PPARAMOUT {
+			r.retvars.Append(name)
+		} else {
+			r.inlvars.Append(name)
+		}
+	}
+}
+
+func (r *reader) addLocal(name *ir.Name, ctxt ir.Class) {
+	assert(ctxt == ir.PAUTO || ctxt == ir.PPARAM || ctxt == ir.PPARAMOUT)
+
+	r.sync(syncAddLocal)
+	if enableSync {
+		want := r.int()
+		if have := len(r.locals); have != want {
+			base.FatalfAt(name.Pos(), "locals table has desynced")
+		}
+	}
+
+	name.SetUsed(true)
+	r.locals = append(r.locals, name)
+
+	// TODO(mdempsky): Move earlier.
+	if ir.IsBlank(name) {
+		return
+	}
+
+	if r.inlCall != nil {
+		if ctxt == ir.PAUTO {
+			name.SetInlLocal(true)
+		} else {
+			name.SetInlFormal(true)
+			ctxt = ir.PAUTO
+		}
+
+		// TODO(mdempsky): Rethink this hack.
+		if strings.HasPrefix(name.Sym().Name, "~") || base.Flag.GenDwarfInl == 0 {
+			name.SetPos(r.inlCall.Pos())
+			name.SetInlFormal(false)
+			name.SetInlLocal(false)
+		}
+	}
+
+	name.Class = ctxt
+	name.Curfn = r.curfn
+
+	r.curfn.Dcl = append(r.curfn.Dcl, name)
+
+	if ctxt == ir.PAUTO {
+		name.SetFrameOffset(0)
+	}
+}
+
+func (r *reader) useLocal() *ir.Name {
+	r.sync(syncUseObjLocal)
+	if r.bool() {
+		return r.locals[r.len()]
+	}
+	return r.closureVars[r.len()]
+}
+
+func (r *reader) openScope() {
+	r.sync(syncOpenScope)
+	pos := r.pos()
+
+	if base.Flag.Dwarf {
+		r.scopeVars = append(r.scopeVars, len(r.curfn.Dcl))
+		r.marker.Push(pos)
+	}
+}
+
+func (r *reader) closeScope() {
+	r.sync(syncCloseScope)
+	r.lastCloseScopePos = r.pos()
+
+	r.closeAnotherScope()
+}
+
+// closeAnotherScope is like closeScope, but it reuses the same mark
+// position as the last closeScope call. This is useful for "for" and
+// "if" statements, as their implicit blocks always end at the same
+// position as an explicit block.
+func (r *reader) closeAnotherScope() {
+	r.sync(syncCloseAnotherScope)
+
+	if base.Flag.Dwarf {
+		scopeVars := r.scopeVars[len(r.scopeVars)-1]
+		r.scopeVars = r.scopeVars[:len(r.scopeVars)-1]
+
+		// Quirkish: noder decides which scopes to keep before
+		// typechecking, whereas incremental typechecking during IR
+		// construction can result in new autotemps being allocated. To
+		// produce identical output, we ignore autotemps here for the
+		// purpose of deciding whether to retract the scope.
+		//
+		// This is important for net/http/fcgi, because it contains:
+		//
+		//	var body io.ReadCloser
+		//	if len(content) > 0 {
+		//		body, req.pw = io.Pipe()
+		//	} else { … }
+		//
+		// Notably, io.Pipe is inlinable, and inlining it introduces a ~R0
+		// variable at the call site.
+		//
+		// Noder does not preserve the scope where the io.Pipe() call
+		// resides, because it doesn't contain any declared variables in
+		// source. So the ~R0 variable ends up being assigned to the
+		// enclosing scope instead.
+		//
+		// However, typechecking this assignment also introduces
+		// autotemps, because io.Pipe's results need conversion before
+		// they can be assigned to their respective destination variables.
+		//
+		// TODO(mdempsky): We should probably just keep all scopes, and
+		// let dwarfgen take care of pruning them instead.
+		retract := true
+		for _, n := range r.curfn.Dcl[scopeVars:] {
+			if !n.AutoTemp() {
+				retract = false
+				break
+			}
+		}
+
+		if retract {
+			// no variables were declared in this scope, so we can retract it.
+			r.marker.Unpush()
+		} else {
+			r.marker.Pop(r.lastCloseScopePos)
+		}
+	}
+}
+
+// @@@ Statements
+
+func (r *reader) stmt() ir.Node {
+	switch stmts := r.stmts(); len(stmts) {
+	case 0:
+		return nil
+	case 1:
+		return stmts[0]
+	default:
+		return ir.NewBlockStmt(stmts[0].Pos(), stmts)
+	}
+}
+
+func (r *reader) stmts() []ir.Node {
+	assert(ir.CurFunc == r.curfn)
+	var res ir.Nodes
+
+	r.sync(syncStmts)
+	for {
+		tag := codeStmt(r.code(syncStmt1))
+		if tag == stmtEnd {
+			r.sync(syncStmtsEnd)
+			return res
+		}
+
+		if n := r.stmt1(tag, &res); n != nil {
+			res.Append(typecheck.Stmt(n))
+		}
+	}
+}
+
+func (r *reader) stmt1(tag codeStmt, out *ir.Nodes) ir.Node {
+	var label *types.Sym
+	if n := len(*out); n > 0 {
+		if ls, ok := (*out)[n-1].(*ir.LabelStmt); ok {
+			label = ls.Label
+		}
+	}
+
+	switch tag {
+	default:
+		panic("unexpected statement")
+
+	case stmtAssign:
+		pos := r.pos()
+
+		// TODO(mdempsky): After quirks mode is gone, swap these
+		// statements so we visit LHS before RHS again.
+		rhs := r.exprList()
+		names, lhs := r.assignList()
+
+		if len(rhs) == 0 {
+			for _, name := range names {
+				as := ir.NewAssignStmt(pos, name, nil)
+				as.PtrInit().Append(ir.NewDecl(pos, ir.ODCL, name))
+				out.Append(typecheck.Stmt(as))
+			}
+			return nil
+		}
+
+		if len(lhs) == 1 && len(rhs) == 1 {
+			n := ir.NewAssignStmt(pos, lhs[0], rhs[0])
+			n.Def = r.initDefn(n, names)
+			return n
+		}
+
+		n := ir.NewAssignListStmt(pos, ir.OAS2, lhs, rhs)
+		n.Def = r.initDefn(n, names)
+		return n
+
+	case stmtAssignOp:
+		op := r.op()
+		lhs := r.expr()
+		pos := r.pos()
+		rhs := r.expr()
+		return ir.NewAssignOpStmt(pos, op, lhs, rhs)
+
+	case stmtIncDec:
+		op := r.op()
+		lhs := r.expr()
+		pos := r.pos()
+		n := ir.NewAssignOpStmt(pos, op, lhs, ir.NewBasicLit(pos, one))
+		n.IncDec = true
+		return n
+
+	case stmtBlock:
+		out.Append(r.blockStmt()...)
+		return nil
+
+	case stmtBranch:
+		pos := r.pos()
+		op := r.op()
+		sym := r.optLabel()
+		return ir.NewBranchStmt(pos, op, sym)
+
+	case stmtCall:
+		pos := r.pos()
+		op := r.op()
+		call := r.expr()
+		return ir.NewGoDeferStmt(pos, op, call)
+
+	case stmtExpr:
+		return r.expr()
+
+	case stmtFor:
+		return r.forStmt(label)
+
+	case stmtIf:
+		return r.ifStmt()
+
+	case stmtLabel:
+		pos := r.pos()
+		sym := r.label()
+		return ir.NewLabelStmt(pos, sym)
+
+	case stmtReturn:
+		pos := r.pos()
+		results := r.exprList()
+		return ir.NewReturnStmt(pos, results)
+
+	case stmtSelect:
+		return r.selectStmt(label)
+
+	case stmtSend:
+		pos := r.pos()
+		ch := r.expr()
+		value := r.expr()
+		return ir.NewSendStmt(pos, ch, value)
+
+	case stmtSwitch:
+		return r.switchStmt(label)
+
+	case stmtTypeDeclHack:
+		// fake "type _ = int" declaration to prevent inlining in quirks mode.
+		assert(quirksMode())
+
+		name := ir.NewDeclNameAt(src.NoXPos, ir.OTYPE, ir.BlankNode.Sym())
+		name.SetAlias(true)
+		r.setType(name, types.Types[types.TINT])
+
+		n := ir.NewDecl(src.NoXPos, ir.ODCLTYPE, name)
+		n.SetTypecheck(1)
+		return n
+	}
+}
+
+func (r *reader) assignList() ([]*ir.Name, []ir.Node) {
+	lhs := make([]ir.Node, r.len())
+	var names []*ir.Name
+
+	for i := range lhs {
+		if r.bool() {
+			pos := r.pos()
+			_, sym := r.localIdent()
+			typ := r.typ()
+
+			name := ir.NewNameAt(pos, sym)
+			lhs[i] = name
+			names = append(names, name)
+			r.setType(name, typ)
+			r.addLocal(name, ir.PAUTO)
+			continue
+		}
+
+		lhs[i] = r.expr()
+	}
+
+	return names, lhs
+}
+
+func (r *reader) blockStmt() []ir.Node {
+	r.sync(syncBlockStmt)
+	r.openScope()
+	stmts := r.stmts()
+	r.closeScope()
+	return stmts
+}
+
+func (r *reader) forStmt(label *types.Sym) ir.Node {
+	r.sync(syncForStmt)
+
+	r.openScope()
+
+	if r.bool() {
+		pos := r.pos()
+
+		// TODO(mdempsky): After quirks mode is gone, swap these
+		// statements so we read LHS before X again.
+		x := r.expr()
+		names, lhs := r.assignList()
+
+		body := r.blockStmt()
+		r.closeAnotherScope()
+
+		rang := ir.NewRangeStmt(pos, nil, nil, x, body)
+		if len(lhs) >= 1 {
+			rang.Key = lhs[0]
+			if len(lhs) >= 2 {
+				rang.Value = lhs[1]
+			}
+		}
+		rang.Def = r.initDefn(rang, names)
+		rang.Label = label
+		return rang
+	}
+
+	pos := r.pos()
+	init := r.stmt()
+	cond := r.expr()
+	post := r.stmt()
+	body := r.blockStmt()
+	r.closeAnotherScope()
+
+	stmt := ir.NewForStmt(pos, init, cond, post, body)
+	stmt.Label = label
+	return stmt
+}
+
+func (r *reader) ifStmt() ir.Node {
+	r.sync(syncIfStmt)
+	r.openScope()
+	pos := r.pos()
+	init := r.stmts()
+	cond := r.expr()
+	then := r.blockStmt()
+	els := r.stmts()
+	n := ir.NewIfStmt(pos, cond, then, els)
+	n.SetInit(init)
+	r.closeAnotherScope()
+	return n
+}
+
+func (r *reader) selectStmt(label *types.Sym) ir.Node {
+	r.sync(syncSelectStmt)
+
+	pos := r.pos()
+	clauses := make([]*ir.CommClause, r.len())
+	for i := range clauses {
+		if i > 0 {
+			r.closeScope()
+		}
+		r.openScope()
+
+		pos := r.pos()
+		comm := r.stmt()
+		body := r.stmts()
+
+		clauses[i] = ir.NewCommStmt(pos, comm, body)
+	}
+	if len(clauses) > 0 {
+		r.closeScope()
+	}
+	n := ir.NewSelectStmt(pos, clauses)
+	n.Label = label
+	return n
+}
+
+func (r *reader) switchStmt(label *types.Sym) ir.Node {
+	r.sync(syncSwitchStmt)
+
+	r.openScope()
+	pos := r.pos()
+	init := r.stmt()
+
+	var tag ir.Node
+	if r.bool() {
+		pos := r.pos()
+		var ident *ir.Ident
+		if r.bool() {
+			pos := r.pos()
+			sym := typecheck.Lookup(r.string())
+			ident = ir.NewIdent(pos, sym)
+		}
+		x := r.expr()
+		tag = ir.NewTypeSwitchGuard(pos, ident, x)
+	} else {
+		tag = r.expr()
+	}
+
+	tswitch, ok := tag.(*ir.TypeSwitchGuard)
+	if ok && tswitch.Tag == nil {
+		tswitch = nil
+	}
+
+	clauses := make([]*ir.CaseClause, r.len())
+	for i := range clauses {
+		if i > 0 {
+			r.closeScope()
+		}
+		r.openScope()
+
+		pos := r.pos()
+		cases := r.exprList()
+
+		clause := ir.NewCaseStmt(pos, cases, nil)
+		if tswitch != nil {
+			pos := r.pos()
+			typ := r.typ()
+
+			name := ir.NewNameAt(pos, tswitch.Tag.Sym())
+			r.setType(name, typ)
+			r.addLocal(name, ir.PAUTO)
+			clause.Var = name
+			name.Defn = tswitch
+		}
+
+		clause.Body = r.stmts()
+		clauses[i] = clause
+	}
+	if len(clauses) > 0 {
+		r.closeScope()
+	}
+	r.closeScope()
+
+	n := ir.NewSwitchStmt(pos, tag, clauses)
+	n.Label = label
+	if init != nil {
+		n.SetInit([]ir.Node{init})
+	}
+	return n
+}
+
+func (r *reader) label() *types.Sym {
+	r.sync(syncLabel)
+	name := r.string()
+	if r.inlCall != nil {
+		name = fmt.Sprintf("~%s·%d", name, inlgen)
+	}
+	return typecheck.Lookup(name)
+}
+
+func (r *reader) optLabel() *types.Sym {
+	r.sync(syncOptLabel)
+	if r.bool() {
+		return r.label()
+	}
+	return nil
+}
+
+// initDefn marks the given names as declared by defn and populates
+// its Init field with ODCL nodes. It then reports whether any names
+// were so declared, which can be used to initialize defn.Def.
+func (r *reader) initDefn(defn ir.InitNode, names []*ir.Name) bool {
+	if len(names) == 0 {
+		return false
+	}
+
+	init := make([]ir.Node, len(names))
+	for i, name := range names {
+		name.Defn = defn
+		init[i] = ir.NewDecl(name.Pos(), ir.ODCL, name)
+	}
+	defn.SetInit(init)
+	return true
+}
+
+// @@@ Expressions
+
+// expr reads and returns a typechecked expression.
+func (r *reader) expr() (res ir.Node) {
+	defer func() {
+		if res != nil && res.Typecheck() == 0 {
+			base.FatalfAt(res.Pos(), "%v missed typecheck", res)
+		}
+	}()
+
+	switch tag := codeExpr(r.code(syncExpr)); tag {
+	default:
+		panic("unhandled expression")
+
+	case exprNone:
+		return nil
+
+	case exprBlank:
+		// blank only allowed in LHS of assignments
+		// TODO(mdempsky): Handle directly in assignList instead?
+		return typecheck.AssignExpr(ir.BlankNode)
+
+	case exprLocal:
+		return typecheck.Expr(r.useLocal())
+
+	case exprName:
+		// Callee instead of Expr allows builtins
+		// TODO(mdempsky): Handle builtins directly in exprCall, like method calls?
+		return typecheck.Callee(r.obj())
+
+	case exprType:
+		// TODO(mdempsky): ir.TypeNode should probably return a typecheck'd node.
+		n := ir.TypeNode(r.typ())
+		n.SetTypecheck(1)
+		return n
+
+	case exprConst:
+		pos := r.pos()
+		typ, val := r.value()
+		op := r.op()
+		orig := r.string()
+		return typecheck.Expr(OrigConst(pos, typ, val, op, orig))
+
+	case exprCompLit:
+		return r.compLit()
+
+	case exprFuncLit:
+		return r.funcLit()
+
+	case exprSelector:
+		x := r.expr()
+		pos := r.pos()
+		_, sym := r.selector()
+		return typecheck.Expr(ir.NewSelectorExpr(pos, ir.OXDOT, x, sym))
+
+	case exprIndex:
+		x := r.expr()
+		pos := r.pos()
+		index := r.expr()
+		return typecheck.Expr(ir.NewIndexExpr(pos, x, index))
+
+	case exprSlice:
+		x := r.expr()
+		pos := r.pos()
+		var index [3]ir.Node
+		for i := range index {
+			index[i] = r.expr()
+		}
+		op := ir.OSLICE
+		if index[2] != nil {
+			op = ir.OSLICE3
+		}
+		return typecheck.Expr(ir.NewSliceExpr(pos, op, x, index[0], index[1], index[2]))
+
+	case exprAssert:
+		x := r.expr()
+		pos := r.pos()
+		typ := r.expr().(ir.Ntype)
+		return typecheck.Expr(ir.NewTypeAssertExpr(pos, x, typ))
+
+	case exprUnaryOp:
+		op := r.op()
+		pos := r.pos()
+		x := r.expr()
+
+		switch op {
+		case ir.OADDR:
+			return typecheck.Expr(typecheck.NodAddrAt(pos, x))
+		case ir.ODEREF:
+			return typecheck.Expr(ir.NewStarExpr(pos, x))
+		}
+		return typecheck.Expr(ir.NewUnaryExpr(pos, op, x))
+
+	case exprBinaryOp:
+		op := r.op()
+		x := r.expr()
+		pos := r.pos()
+		y := r.expr()
+
+		switch op {
+		case ir.OANDAND, ir.OOROR:
+			return typecheck.Expr(ir.NewLogicalExpr(pos, op, x, y))
+		}
+		return typecheck.Expr(ir.NewBinaryExpr(pos, op, x, y))
+
+	case exprCall:
+		fun := r.expr()
+		if r.bool() { // method call
+			pos := r.pos()
+			_, sym := r.selector()
+			fun = typecheck.Callee(ir.NewSelectorExpr(pos, ir.OXDOT, fun, sym))
+		}
+		pos := r.pos()
+		args := r.exprs()
+		dots := r.bool()
+		return typecheck.Call(pos, fun, args, dots)
+
+	case exprConvert:
+		typ := r.typ()
+		pos := r.pos()
+		x := r.expr()
+		return typecheck.Expr(ir.NewConvExpr(pos, ir.OCONV, typ, x))
+	}
+}
+
+func (r *reader) compLit() ir.Node {
+	r.sync(syncCompLit)
+	pos := r.pos()
+	typ0 := r.typ()
+
+	typ := typ0
+	if typ.IsPtr() {
+		typ = typ.Elem()
+	}
+	if typ.Kind() == types.TFORW {
+		base.FatalfAt(pos, "unresolved composite literal type: %v", typ)
+	}
+	isStruct := typ.Kind() == types.TSTRUCT
+
+	elems := make([]ir.Node, r.len())
+	for i := range elems {
+		elemp := &elems[i]
+
+		if isStruct {
+			sk := ir.NewStructKeyExpr(r.pos(), typ.Field(r.len()), nil)
+			*elemp, elemp = sk, &sk.Value
+		} else if r.bool() {
+			kv := ir.NewKeyExpr(r.pos(), r.expr(), nil)
+			*elemp, elemp = kv, &kv.Value
+		}
+
+		*elemp = wrapName(r.pos(), r.expr())
+	}
+
+	lit := typecheck.Expr(ir.NewCompLitExpr(pos, ir.OCOMPLIT, ir.TypeNode(typ), elems))
+	if typ0.IsPtr() {
+		lit = typecheck.Expr(typecheck.NodAddrAt(pos, lit))
+		lit.SetType(typ0)
+	}
+	return lit
+}
+
+func wrapName(pos src.XPos, x ir.Node) ir.Node {
+	// These nodes do not carry line numbers.
+	// Introduce a wrapper node to give them the correct line.
+	switch ir.Orig(x).Op() {
+	case ir.OTYPE, ir.OLITERAL:
+		if x.Sym() == nil {
+			break
+		}
+		fallthrough
+	case ir.ONAME, ir.ONONAME, ir.OPACK, ir.ONIL:
+		p := ir.NewParenExpr(pos, x)
+		p.SetImplicit(true)
+		return p
+	}
+	return x
+}
+
+func (r *reader) funcLit() ir.Node {
+	r.sync(syncFuncLit)
+
+	pos := r.pos()
+	typPos := r.pos()
+	xtype2 := r.signature(types.LocalPkg, nil)
+
+	opos := pos
+	if quirksMode() {
+		opos = r.origPos(pos)
+	}
+
+	fn := ir.NewClosureFunc(opos, r.curfn != nil)
+	clo := fn.OClosure
+	ir.NameClosure(clo, r.curfn)
+
+	r.setType(fn.Nname, xtype2)
+	if quirksMode() {
+		fn.Nname.Ntype = ir.TypeNodeAt(typPos, xtype2)
+	}
+	typecheck.Func(fn)
+	r.setType(clo, fn.Type())
+
+	fn.ClosureVars = make([]*ir.Name, 0, r.len())
+	for len(fn.ClosureVars) < cap(fn.ClosureVars) {
+		ir.NewClosureVar(r.pos(), fn, r.useLocal())
+	}
+
+	r.addBody(fn)
+
+	// TODO(mdempsky): Remove hard-coding of typecheck.Target.
+	return ir.UseClosure(clo, typecheck.Target)
+}
+
+func (r *reader) exprList() []ir.Node {
+	r.sync(syncExprList)
+	return r.exprs()
+}
+
+func (r *reader) exprs() []ir.Node {
+	r.sync(syncExprs)
+	nodes := make([]ir.Node, r.len())
+	if len(nodes) == 0 {
+		return nil // TODO(mdempsky): Unclear if this matters.
+	}
+	for i := range nodes {
+		nodes[i] = r.expr()
+	}
+	return nodes
+}
+
+func (r *reader) op() ir.Op {
+	r.sync(syncOp)
+	return ir.Op(r.len())
+}
+
+// @@@ Package initialization
+
+func (r *reader) pkgInit(self *types.Pkg, target *ir.Package) {
+	if quirksMode() {
+		for i, n := 0, r.len(); i < n; i++ {
+			// Eagerly register position bases, so their filenames are
+			// assigned stable indices.
+			posBase := r.posBase()
+			_ = base.Ctxt.PosTable.XPos(src.MakePos(posBase, 0, 0))
+		}
+
+		for i, n := 0, r.len(); i < n; i++ {
+			// Eagerly resolve imported objects, so any filenames registered
+			// in the process are assigned stable indices too.
+			_, sym := r.qualifiedIdent()
+			typecheck.Resolve(ir.NewIdent(src.NoXPos, sym))
+			assert(sym.Def != nil)
+		}
+	}
+
+	cgoPragmas := make([][]string, r.len())
+	for i := range cgoPragmas {
+		cgoPragmas[i] = r.strings()
+	}
+	target.CgoPragmas = cgoPragmas
+
+	r.pkgDecls(target)
+
+	r.sync(syncEOF)
+}
+
+func (r *reader) pkgDecls(target *ir.Package) {
+	r.sync(syncDecls)
+	for {
+		switch code := codeDecl(r.code(syncDecl)); code {
+		default:
+			panic(fmt.Sprintf("unhandled decl: %v", code))
+
+		case declEnd:
+			return
+
+		case declFunc:
+			names := r.pkgObjs(target)
+			assert(len(names) == 1)
+			target.Decls = append(target.Decls, names[0].Func)
+
+		case declMethod:
+			typ := r.typ()
+			_, sym := r.selector()
+
+			method := typecheck.Lookdot1(nil, sym, typ, typ.Methods(), 0)
+			target.Decls = append(target.Decls, method.Nname.(*ir.Name).Func)
+
+		case declVar:
+			pos := r.pos()
+			names := r.pkgObjs(target)
+			values := r.exprList()
+
+			if len(names) > 1 && len(values) == 1 {
+				as := ir.NewAssignListStmt(pos, ir.OAS2, nil, values)
+				for _, name := range names {
+					as.Lhs.Append(name)
+					name.Defn = as
+				}
+				target.Decls = append(target.Decls, as)
+			} else {
+				for i, name := range names {
+					as := ir.NewAssignStmt(pos, name, nil)
+					if i < len(values) {
+						as.Y = values[i]
+					}
+					name.Defn = as
+					target.Decls = append(target.Decls, as)
+				}
+			}
+
+			if n := r.len(); n > 0 {
+				assert(len(names) == 1)
+				embeds := make([]ir.Embed, n)
+				for i := range embeds {
+					embeds[i] = ir.Embed{Pos: r.pos(), Patterns: r.strings()}
+				}
+				names[0].Embed = &embeds
+				target.Embeds = append(target.Embeds, names[0])
+			}
+
+		case declOther:
+			r.pkgObjs(target)
+		}
+	}
+}
+
+func (r *reader) pkgObjs(target *ir.Package) []*ir.Name {
+	r.sync(syncDeclNames)
+	nodes := make([]*ir.Name, r.len())
+	for i := range nodes {
+		r.sync(syncDeclName)
+
+		name := r.obj().(*ir.Name)
+		nodes[i] = name
+
+		sym := name.Sym()
+		if sym.IsBlank() {
+			continue
+		}
+
+		switch name.Class {
+		default:
+			base.FatalfAt(name.Pos(), "unexpected class: %v", name.Class)
+
+		case ir.PEXTERN:
+			target.Externs = append(target.Externs, name)
+
+		case ir.PFUNC:
+			assert(name.Type().Recv() == nil)
+
+			// TODO(mdempsky): Cleaner way to recognize init?
+			if strings.HasPrefix(sym.Name, "init.") {
+				target.Inits = append(target.Inits, name.Func)
+			}
+		}
+
+		if types.IsExported(sym.Name) {
+			assert(!sym.OnExportList())
+			target.Exports = append(target.Exports, name)
+			sym.SetOnExportList(true)
+		}
+
+		if base.Flag.AsmHdr != "" {
+			assert(!sym.Asm())
+			target.Asms = append(target.Asms, name)
+			sym.SetAsm(true)
+		}
+	}
+
+	return nodes
+}
+
+// @@@ Inlining
+
+var inlgen = 0
+
+func InlineCall(call *ir.CallExpr, fn *ir.Func, inlIndex int) *ir.InlinedCallExpr {
+	// TODO(mdempsky): Turn callerfn into an explicit parameter.
+	callerfn := ir.CurFunc
+
+	pri, ok := bodyReader[fn]
+	if !ok {
+		// Assume it's an imported function or something that we don't
+		// have access to in quirks mode.
+		if haveLegacyImports {
+			return nil
+		}
+
+		base.FatalfAt(call.Pos(), "missing function body for call to %v", fn)
+	}
+
+	if fn.Inl.Body == nil {
+		expandInline(fn, pri)
+	}
+
+	r := pri.asReader(relocBody, syncFuncBody)
+
+	// TODO(mdempsky): This still feels clumsy. Can we do better?
+	tmpfn := ir.NewFunc(fn.Pos())
+	tmpfn.Nname = ir.NewNameAt(fn.Nname.Pos(), callerfn.Sym())
+	tmpfn.Closgen = callerfn.Closgen
+	defer func() { callerfn.Closgen = tmpfn.Closgen }()
+
+	r.setType(tmpfn.Nname, fn.Type())
+	r.curfn = tmpfn
+
+	r.inlCaller = callerfn
+	r.inlCall = call
+	r.inlFunc = fn
+	r.inlTreeIndex = inlIndex
+	r.inlPosBases = make(map[*src.PosBase]*src.PosBase)
+
+	r.closureVars = make([]*ir.Name, len(r.inlFunc.ClosureVars))
+	for i, cv := range r.inlFunc.ClosureVars {
+		r.closureVars[i] = cv.Outer
+	}
+
+	r.funcargs(fn)
+
+	assert(r.bool()) // have body
+	r.delayResults = fn.Inl.CanDelayResults
+
+	r.retlabel = typecheck.AutoLabel(".i")
+	inlgen++
+
+	init := ir.TakeInit(call)
+
+	// For normal function calls, the function callee expression
+	// may contain side effects. Make sure to preserve these,
+	// if necessary (#42703).
+	if call.Op() == ir.OCALLFUNC {
+		inline.CalleeEffects(&init, call.X)
+	}
+
+	var args ir.Nodes
+	if call.Op() == ir.OCALLMETH {
+		base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck")
+	}
+	args.Append(call.Args...)
+
+	// Create assignment to declare and initialize inlvars.
+	as2 := ir.NewAssignListStmt(call.Pos(), ir.OAS2, r.inlvars, args)
+	as2.Def = true
+	var as2init ir.Nodes
+	for _, name := range r.inlvars {
+		if ir.IsBlank(name) {
+			continue
+		}
+		// TODO(mdempsky): Use inlined position of name.Pos() instead?
+		name := name.(*ir.Name)
+		as2init.Append(ir.NewDecl(call.Pos(), ir.ODCL, name))
+		name.Defn = as2
+	}
+	as2.SetInit(as2init)
+	init.Append(typecheck.Stmt(as2))
+
+	if !r.delayResults {
+		// If not delaying retvars, declare and zero initialize the
+		// result variables now.
+		for _, name := range r.retvars {
+			// TODO(mdempsky): Use inlined position of name.Pos() instead?
+			name := name.(*ir.Name)
+			init.Append(ir.NewDecl(call.Pos(), ir.ODCL, name))
+			ras := ir.NewAssignStmt(call.Pos(), name, nil)
+			init.Append(typecheck.Stmt(ras))
+		}
+	}
+
+	// Add an inline mark just before the inlined body.
+	// This mark is inline in the code so that it's a reasonable spot
+	// to put a breakpoint. Not sure if that's really necessary or not
+	// (in which case it could go at the end of the function instead).
+	// Note issue 28603.
+	init.Append(ir.NewInlineMarkStmt(call.Pos().WithIsStmt(), int64(r.inlTreeIndex)))
+
+	nparams := len(r.curfn.Dcl)
+
+	ir.WithFunc(r.curfn, func() {
+		r.curfn.Body = r.stmts()
+		r.curfn.Endlineno = r.pos()
+
+		deadcode.Func(r.curfn)
+
+		// Replace any "return" statements within the function body.
+		var edit func(ir.Node) ir.Node
+		edit = func(n ir.Node) ir.Node {
+			if ret, ok := n.(*ir.ReturnStmt); ok {
+				n = typecheck.Stmt(r.inlReturn(ret))
+			}
+			ir.EditChildren(n, edit)
+			return n
+		}
+		edit(r.curfn)
+	})
+
+	body := ir.Nodes(r.curfn.Body)
+
+	// Quirk: If deadcode elimination turned a non-empty function into
+	// an empty one, we need to set the position for the empty block
+	// left behind to the the inlined position for src.NoXPos, so that
+	// an empty string gets added into the DWARF file name listing at
+	// the appropriate index.
+	if quirksMode() && len(body) == 1 {
+		if block, ok := body[0].(*ir.BlockStmt); ok && len(block.List) == 0 {
+			block.SetPos(r.updatePos(src.NoXPos))
+		}
+	}
+
+	// Quirkish: We need to eagerly prune variables added during
+	// inlining, but removed by deadcode.FuncBody above. Unused
+	// variables will get removed during stack frame layout anyway, but
+	// len(fn.Dcl) ends up influencing things like autotmp naming.
+
+	used := usedLocals(body)
+
+	for i, name := range r.curfn.Dcl {
+		if i < nparams || used.Has(name) {
+			name.Curfn = callerfn
+			callerfn.Dcl = append(callerfn.Dcl, name)
+
+			// Quirkish. TODO(mdempsky): Document why.
+			if name.AutoTemp() {
+				name.SetEsc(ir.EscUnknown)
+
+				if base.Flag.GenDwarfInl != 0 {
+					name.SetInlLocal(true)
+				} else {
+					name.SetPos(r.inlCall.Pos())
+				}
+			}
+		}
+	}
+
+	body.Append(ir.NewLabelStmt(call.Pos(), r.retlabel))
+
+	res := ir.NewInlinedCallExpr(call.Pos(), body, append([]ir.Node(nil), r.retvars...))
+	res.SetInit(init)
+	res.SetType(call.Type())
+	res.SetTypecheck(1)
+
+	// Inlining shouldn't add any functions to todoBodies.
+	assert(len(todoBodies) == 0)
+
+	return res
+}
+
+// inlReturn returns a statement that can substitute for the given
+// return statement when inlining.
+func (r *reader) inlReturn(ret *ir.ReturnStmt) *ir.BlockStmt {
+	pos := r.inlCall.Pos()
+
+	block := ir.TakeInit(ret)
+
+	if results := ret.Results; len(results) != 0 {
+		assert(len(r.retvars) == len(results))
+
+		as2 := ir.NewAssignListStmt(pos, ir.OAS2, append([]ir.Node(nil), r.retvars...), ret.Results)
+
+		if r.delayResults {
+			for _, name := range r.retvars {
+				// TODO(mdempsky): Use inlined position of name.Pos() instead?
+				name := name.(*ir.Name)
+				block.Append(ir.NewDecl(pos, ir.ODCL, name))
+				name.Defn = as2
+			}
+		}
+
+		block.Append(as2)
+	}
+
+	block.Append(ir.NewBranchStmt(pos, ir.OGOTO, r.retlabel))
+	return ir.NewBlockStmt(pos, block)
+}
+
+// expandInline reads in an extra copy of IR to populate
+// fn.Inl.{Dcl,Body}.
+func expandInline(fn *ir.Func, pri pkgReaderIndex) {
+	// TODO(mdempsky): Remove this function. It's currently needed by
+	// dwarfgen/dwarf.go:preInliningDcls, which requires fn.Inl.Dcl to
+	// create abstract function DIEs. But we should be able to provide it
+	// with the same information some other way.
+
+	fndcls := len(fn.Dcl)
+	topdcls := len(typecheck.Target.Decls)
+
+	tmpfn := ir.NewFunc(fn.Pos())
+	tmpfn.Nname = ir.NewNameAt(fn.Nname.Pos(), fn.Sym())
+	tmpfn.ClosureVars = fn.ClosureVars
+
+	{
+		r := pri.asReader(relocBody, syncFuncBody)
+		r.setType(tmpfn.Nname, fn.Type())
+
+		// Don't change parameter's Sym/Nname fields.
+		r.funarghack = true
+
+		r.funcBody(tmpfn)
+
+		ir.WithFunc(tmpfn, func() {
+			deadcode.Func(tmpfn)
+		})
+	}
+
+	used := usedLocals(tmpfn.Body)
+
+	for _, name := range tmpfn.Dcl {
+		if name.Class != ir.PAUTO || used.Has(name) {
+			name.Curfn = fn
+			fn.Inl.Dcl = append(fn.Inl.Dcl, name)
+		}
+	}
+	fn.Inl.Body = tmpfn.Body
+
+	// Double check that we didn't change fn.Dcl by accident.
+	assert(fndcls == len(fn.Dcl))
+
+	// typecheck.Stmts may have added function literals to
+	// typecheck.Target.Decls. Remove them again so we don't risk trying
+	// to compile them multiple times.
+	typecheck.Target.Decls = typecheck.Target.Decls[:topdcls]
+}
+
+// usedLocals returns a set of local variables that are used within body.
+func usedLocals(body []ir.Node) ir.NameSet {
+	var used ir.NameSet
+	ir.VisitList(body, func(n ir.Node) {
+		if n, ok := n.(*ir.Name); ok && n.Op() == ir.ONAME && n.Class == ir.PAUTO {
+			used.Add(n)
+		}
+	})
+	return used
+}
+
+// @@@ Method wrappers
+
+// needWrapperTypes lists types for which we may need to generate
+// method wrappers.
+var needWrapperTypes []*types.Type
+
+// haveWrapperTypes lists types for which we know we already have
+// method wrappers, because we found the type in an imported package.
+var haveWrapperTypes []*types.Type
+
+func (r *reader) needWrapper(typ *types.Type) *types.Type {
+	if typ.IsPtr() {
+		base.Fatalf("bad pointer type: %v", typ)
+	}
+
+	// If a type was found in an imported package, then we can assume
+	// that package (or one of its transitive dependencies) already
+	// generated method wrappers for it.
+	//
+	// Exception: If we're instantiating an imported generic type or
+	// function, we might be instantiating it with type arguments not
+	// previously seen before.
+	//
+	// TODO(mdempsky): Distinguish when a generic function or type was
+	// instantiated in an imported package so that we can add types to
+	// haveWrapperTypes instead.
+	if r.p != localPkgReader && !r.hasTypeParams() {
+		haveWrapperTypes = append(haveWrapperTypes, typ)
+	} else {
+		needWrapperTypes = append(needWrapperTypes, typ)
+	}
+
+	return typ
+}
+
+func (r *reader) wrapTypes(target *ir.Package) {
+	// always generate a wrapper for error.Error (#29304)
+	r.needWrapper(types.ErrorType)
+
+	seen := make(map[string]*types.Type)
+	addType := func(typ *types.Type) bool {
+		if typ.Sym() != nil {
+			return true
+		}
+
+		key := typ.LinkString()
+		if prev := seen[key]; prev != nil {
+			if !types.Identical(typ, prev) {
+				base.Fatalf("collision: types %v and %v have short string %q", typ, prev, key)
+			}
+			return false
+		}
+
+		seen[key] = typ
+		return true
+	}
+
+	for _, typ := range haveWrapperTypes {
+		addType(typ)
+	}
+	haveWrapperTypes = nil
+
+	for _, typ := range needWrapperTypes {
+		if addType(typ) {
+			r.wrapType(typ, target)
+		}
+	}
+	needWrapperTypes = nil
+}
+
+func (r *reader) wrapType(typ *types.Type, target *ir.Package) {
+	if !typ.IsInterface() {
+		typecheck.CalcMethods(typ)
+	}
+	for _, meth := range typ.AllMethods().Slice() {
+		if meth.Sym.IsBlank() || !meth.IsMethod() {
+			base.FatalfAt(meth.Pos, "invalid method: %v", meth)
+		}
+
+		r.methodValueWrapper(typ, meth, target)
+
+		r.methodWrapper(0, typ, meth, target)
+
+		// For non-interface types, we also want *T wrappers.
+		if !typ.IsInterface() {
+			r.methodWrapper(1, typ, meth, target)
+
+			// For not-in-heap types, *T is a scalar, not pointer shaped,
+			// so the interface wrappers use **T.
+			if typ.NotInHeap() {
+				r.methodWrapper(2, typ, meth, target)
+			}
+		}
+	}
+}
+
+func (r *reader) methodWrapper(derefs int, tbase *types.Type, method *types.Field, target *ir.Package) {
+	wrapper := tbase
+	for i := 0; i < derefs; i++ {
+		wrapper = types.NewPtr(wrapper)
+	}
+
+	sym := ir.MethodSym(wrapper, method.Sym)
+	assert(!sym.Siggen())
+	sym.SetSiggen(true)
+
+	wrappee := method.Type.Recv().Type
+	if types.Identical(wrapper, wrappee) ||
+		!types.IsMethodApplicable(wrapper, method) ||
+		!reflectdata.NeedEmit(tbase) {
+		return
+	}
+
+	// TODO(mdempsky): Use method.Pos instead?
+	pos := base.AutogeneratedPos
+
+	fn := r.newWrapperFunc(pos, sym, wrapper, method)
+
+	var recv ir.Node = fn.Nname.Type().Recv().Nname.(*ir.Name)
+
+	// For simple *T wrappers around T methods, panicwrap produces a
+	// nicer panic message.
+	if wrapper.IsPtr() && types.Identical(wrapper.Elem(), wrappee) {
+		cond := ir.NewBinaryExpr(pos, ir.OEQ, recv, types.BuiltinPkg.Lookup("nil").Def.(ir.Node))
+		then := []ir.Node{ir.NewCallExpr(pos, ir.OCALL, typecheck.LookupRuntime("panicwrap"), nil)}
+		fn.Body.Append(ir.NewIfStmt(pos, cond, then, nil))
+	}
+
+	// typecheck will add one implicit deref, if necessary,
+	// but not-in-heap types require more for their **T wrappers.
+	for i := 1; i < derefs; i++ {
+		recv = Implicit(ir.NewStarExpr(pos, recv))
+	}
+
+	addTailCall(pos, fn, recv, method)
+
+	r.finishWrapperFunc(fn, target)
+}
+
+func (r *reader) methodValueWrapper(tbase *types.Type, method *types.Field, target *ir.Package) {
+	recvType := tbase
+	if !tbase.IsInterface() {
+		recvType = method.Type.Recv().Type
+		if !types.Identical(tbase, types.ReceiverBaseType(recvType)) {
+			return
+		}
+	}
+
+	sym := ir.MethodSymSuffix(recvType, method.Sym, "-fm")
+	assert(!sym.Uniq())
+	sym.SetUniq(true)
+
+	// TODO(mdempsky): Use method.Pos instead?
+	pos := base.AutogeneratedPos
+
+	fn := r.newWrapperFunc(pos, sym, nil, method)
+	sym.Def = fn.Nname
+
+	// Declare and initialize variable holding receiver.
+	recv := ir.NewHiddenParam(pos, fn, typecheck.Lookup(".this"), recvType)
+
+	if !reflectdata.NeedEmit(tbase) {
+		typecheck.Func(fn)
+		return
+	}
+
+	addTailCall(pos, fn, recv, method)
+
+	r.finishWrapperFunc(fn, target)
+}
+
+func (r *reader) newWrapperFunc(pos src.XPos, sym *types.Sym, wrapper *types.Type, method *types.Field) *ir.Func {
+	fn := ir.NewFunc(pos)
+	fn.SetDupok(true) // TODO(mdempsky): Leave unset for local, non-generic wrappers?
+
+	name := ir.NewNameAt(pos, sym)
+	ir.MarkFunc(name)
+	name.Func = fn
+	name.Defn = fn
+	fn.Nname = name
+
+	sig := newWrapperType(wrapper, method)
+	r.setType(name, sig)
+
+	// TODO(mdempsky): De-duplicate with similar logic in funcargs.
+	defParams := func(class ir.Class, params *types.Type) {
+		for _, param := range params.FieldSlice() {
+			name := ir.NewNameAt(param.Pos, param.Sym)
+			name.Class = class
+			r.setType(name, param.Type)
+
+			name.Curfn = fn
+			fn.Dcl = append(fn.Dcl, name)
+
+			param.Nname = name
+		}
+	}
+
+	defParams(ir.PPARAM, sig.Recvs())
+	defParams(ir.PPARAM, sig.Params())
+	defParams(ir.PPARAMOUT, sig.Results())
+
+	return fn
+}
+
+func (r *reader) finishWrapperFunc(fn *ir.Func, target *ir.Package) {
+	typecheck.Func(fn)
+
+	ir.WithFunc(fn, func() {
+		typecheck.Stmts(fn.Body)
+	})
+
+	target.Decls = append(target.Decls, fn)
+}
+
+// newWrapperType returns a copy of the given signature type, but with
+// the receiver parameter type substituted with recvType.
+// If recvType is nil, newWrapperType returns a signature
+// without a receiver parameter.
+func newWrapperType(recvType *types.Type, method *types.Field) *types.Type {
+	clone := func(params []*types.Field) []*types.Field {
+		res := make([]*types.Field, len(params))
+		for i, param := range params {
+			sym := param.Sym
+			if sym == nil || sym.Name == "_" {
+				sym = typecheck.LookupNum(".anon", i)
+			}
+			res[i] = types.NewField(param.Pos, sym, param.Type)
+			res[i].SetIsDDD(param.IsDDD())
+		}
+		return res
+	}
+
+	sig := method.Type
+
+	var recv *types.Field
+	if recvType != nil {
+		recv = types.NewField(sig.Recv().Pos, typecheck.Lookup(".this"), recvType)
+	}
+	params := clone(sig.Params().FieldSlice())
+	results := clone(sig.Results().FieldSlice())
+
+	return types.NewSignature(types.NoPkg, recv, nil, params, results)
+}
+
+func addTailCall(pos src.XPos, fn *ir.Func, recv ir.Node, method *types.Field) {
+	sig := fn.Nname.Type()
+	args := make([]ir.Node, sig.NumParams())
+	for i, param := range sig.Params().FieldSlice() {
+		args[i] = param.Nname.(*ir.Name)
+	}
+
+	// TODO(mdempsky): Support creating OTAILCALL, when possible. See reflectdata.methodWrapper.
+	// Not urgent though, because tail calls are currently incompatible with regabi anyway.
+
+	fn.SetWrapper(true) // TODO(mdempsky): Leave unset for tail calls?
+
+	dot := ir.NewSelectorExpr(pos, ir.OXDOT, recv, method.Sym)
+	call := typecheck.Call(pos, dot, args, method.Type.IsVariadic()).(*ir.CallExpr)
+
+	if method.Type.NumResults() == 0 {
+		fn.Body.Append(call)
+		return
+	}
+
+	ret := ir.NewReturnStmt(pos, nil)
+	ret.Results = []ir.Node{call}
+	fn.Body.Append(ret)
+}
diff --git a/src/cmd/compile/internal/noder/reader2.go b/src/cmd/compile/internal/noder/reader2.go
new file mode 100644
index 00000000000..97ea4fcb76d
--- /dev/null
+++ b/src/cmd/compile/internal/noder/reader2.go
@@ -0,0 +1,510 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"go/constant"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/syntax"
+	"cmd/compile/internal/types2"
+	"cmd/internal/src"
+)
+
+type pkgReader2 struct {
+	pkgDecoder
+
+	check   *types2.Checker
+	imports map[string]*types2.Package
+
+	posBases []*syntax.PosBase
+	pkgs     []*types2.Package
+	typs     []types2.Type
+}
+
+func readPackage2(check *types2.Checker, imports map[string]*types2.Package, input pkgDecoder) *types2.Package {
+	pr := pkgReader2{
+		pkgDecoder: input,
+
+		check:   check,
+		imports: imports,
+
+		posBases: make([]*syntax.PosBase, input.numElems(relocPosBase)),
+		pkgs:     make([]*types2.Package, input.numElems(relocPkg)),
+		typs:     make([]types2.Type, input.numElems(relocType)),
+	}
+
+	r := pr.newReader(relocMeta, publicRootIdx, syncPublic)
+	pkg := r.pkg()
+	r.bool() // has init
+
+	for i, n := 0, r.len(); i < n; i++ {
+		r.obj()
+	}
+
+	r.sync(syncEOF)
+
+	pkg.MarkComplete()
+	return pkg
+}
+
+type reader2 struct {
+	decoder
+
+	p *pkgReader2
+
+	dict *reader2Dict
+}
+
+type reader2Dict struct {
+	bounds []typeInfo
+
+	tparams []*types2.TypeParam
+
+	derived      []derivedInfo
+	derivedTypes []types2.Type
+}
+
+type reader2TypeBound struct {
+	derived  bool
+	boundIdx int
+}
+
+func (pr *pkgReader2) newReader(k reloc, idx int, marker syncMarker) *reader2 {
+	return &reader2{
+		decoder: pr.newDecoder(k, idx, marker),
+		p:       pr,
+	}
+}
+
+// @@@ Positions
+
+func (r *reader2) pos() syntax.Pos {
+	r.sync(syncPos)
+	if !r.bool() {
+		return syntax.Pos{}
+	}
+
+	// TODO(mdempsky): Delta encoding.
+	posBase := r.posBase()
+	line := r.uint()
+	col := r.uint()
+	return syntax.MakePos(posBase, line, col)
+}
+
+func (r *reader2) posBase() *syntax.PosBase {
+	return r.p.posBaseIdx(r.reloc(relocPosBase))
+}
+
+func (pr *pkgReader2) posBaseIdx(idx int) *syntax.PosBase {
+	if b := pr.posBases[idx]; b != nil {
+		return b
+	}
+
+	r := pr.newReader(relocPosBase, idx, syncPosBase)
+	var b *syntax.PosBase
+
+	filename := r.string()
+	_ = r.string() // absolute file name
+
+	if r.bool() {
+		b = syntax.NewFileBase(filename)
+	} else {
+		pos := r.pos()
+		line := r.uint()
+		col := r.uint()
+		b = syntax.NewLineBase(pos, filename, line, col)
+	}
+
+	pr.posBases[idx] = b
+	return b
+}
+
+// @@@ Packages
+
+func (r *reader2) pkg() *types2.Package {
+	r.sync(syncPkg)
+	return r.p.pkgIdx(r.reloc(relocPkg))
+}
+
+func (pr *pkgReader2) pkgIdx(idx int) *types2.Package {
+	// TODO(mdempsky): Consider using some non-nil pointer to indicate
+	// the universe scope, so we don't need to keep re-reading it.
+	if pkg := pr.pkgs[idx]; pkg != nil {
+		return pkg
+	}
+
+	pkg := pr.newReader(relocPkg, idx, syncPkgDef).doPkg()
+	pr.pkgs[idx] = pkg
+	return pkg
+}
+
+func (r *reader2) doPkg() *types2.Package {
+	path := r.string()
+	if path == "builtin" {
+		return nil // universe
+	}
+	if path == "" {
+		path = r.p.pkgPath
+	}
+
+	if pkg := r.p.imports[path]; pkg != nil {
+		return pkg
+	}
+
+	name := r.string()
+	height := r.len()
+
+	pkg := types2.NewPackageHeight(path, name, height)
+	r.p.imports[path] = pkg
+
+	// TODO(mdempsky): The list of imported packages is important for
+	// go/types, but we could probably skip populating it for types2.
+	imports := make([]*types2.Package, r.len())
+	for i := range imports {
+		imports[i] = r.pkg()
+	}
+	pkg.SetImports(imports)
+
+	return pkg
+}
+
+// @@@ Types
+
+func (r *reader2) typ() types2.Type {
+	return r.p.typIdx(r.typInfo(), r.dict)
+}
+
+func (r *reader2) typInfo() typeInfo {
+	r.sync(syncType)
+	if r.bool() {
+		return typeInfo{idx: r.len(), derived: true}
+	}
+	return typeInfo{idx: r.reloc(relocType), derived: false}
+}
+
+func (pr *pkgReader2) typIdx(info typeInfo, dict *reader2Dict) types2.Type {
+	idx := info.idx
+	var where *types2.Type
+	if info.derived {
+		where = &dict.derivedTypes[idx]
+		idx = dict.derived[idx].idx
+	} else {
+		where = &pr.typs[idx]
+	}
+
+	if typ := *where; typ != nil {
+		return typ
+	}
+
+	r := pr.newReader(relocType, idx, syncTypeIdx)
+	r.dict = dict
+
+	typ := r.doTyp()
+	assert(typ != nil)
+
+	// See comment in pkgReader.typIdx explaining how this happens.
+	if prev := *where; prev != nil {
+		return prev
+	}
+
+	*where = typ
+	return typ
+}
+
+func (r *reader2) doTyp() (res types2.Type) {
+	switch tag := codeType(r.code(syncType)); tag {
+	default:
+		base.FatalfAt(src.NoXPos, "unhandled type tag: %v", tag)
+		panic("unreachable")
+
+	case typeBasic:
+		return types2.Typ[r.len()]
+
+	case typeNamed:
+		obj, targs := r.obj()
+		name := obj.(*types2.TypeName)
+		if len(targs) != 0 {
+			return r.p.check.Instantiate(syntax.Pos{}, name.Type(), targs, nil, false)
+		}
+		return name.Type()
+
+	case typeTypeParam:
+		return r.dict.tparams[r.len()]
+
+	case typeArray:
+		len := int64(r.uint64())
+		return types2.NewArray(r.typ(), len)
+	case typeChan:
+		dir := types2.ChanDir(r.len())
+		return types2.NewChan(dir, r.typ())
+	case typeMap:
+		return types2.NewMap(r.typ(), r.typ())
+	case typePointer:
+		return types2.NewPointer(r.typ())
+	case typeSignature:
+		return r.signature(nil)
+	case typeSlice:
+		return types2.NewSlice(r.typ())
+	case typeStruct:
+		return r.structType()
+	case typeInterface:
+		return r.interfaceType()
+	case typeUnion:
+		return r.unionType()
+	}
+}
+
+func (r *reader2) structType() *types2.Struct {
+	fields := make([]*types2.Var, r.len())
+	var tags []string
+	for i := range fields {
+		pos := r.pos()
+		pkg, name := r.selector()
+		ftyp := r.typ()
+		tag := r.string()
+		embedded := r.bool()
+
+		fields[i] = types2.NewField(pos, pkg, name, ftyp, embedded)
+		if tag != "" {
+			for len(tags) < i {
+				tags = append(tags, "")
+			}
+			tags = append(tags, tag)
+		}
+	}
+	return types2.NewStruct(fields, tags)
+}
+
+func (r *reader2) unionType() *types2.Union {
+	terms := make([]*types2.Term, r.len())
+	for i := range terms {
+		terms[i] = types2.NewTerm(r.bool(), r.typ())
+	}
+	return types2.NewUnion(terms)
+}
+
+func (r *reader2) interfaceType() *types2.Interface {
+	methods := make([]*types2.Func, r.len())
+	embeddeds := make([]types2.Type, r.len())
+
+	for i := range methods {
+		pos := r.pos()
+		pkg, name := r.selector()
+		mtyp := r.signature(nil)
+		methods[i] = types2.NewFunc(pos, pkg, name, mtyp)
+	}
+
+	for i := range embeddeds {
+		embeddeds[i] = r.typ()
+	}
+
+	return types2.NewInterfaceType(methods, embeddeds)
+}
+
+func (r *reader2) signature(recv *types2.Var) *types2.Signature {
+	r.sync(syncSignature)
+
+	params := r.params()
+	results := r.params()
+	variadic := r.bool()
+
+	return types2.NewSignature(recv, params, results, variadic)
+}
+
+func (r *reader2) params() *types2.Tuple {
+	r.sync(syncParams)
+	params := make([]*types2.Var, r.len())
+	for i := range params {
+		params[i] = r.param()
+	}
+	return types2.NewTuple(params...)
+}
+
+func (r *reader2) param() *types2.Var {
+	r.sync(syncParam)
+
+	pos := r.pos()
+	pkg, name := r.localIdent()
+	typ := r.typ()
+
+	return types2.NewParam(pos, pkg, name, typ)
+}
+
+// @@@ Objects
+
+func (r *reader2) obj() (types2.Object, []types2.Type) {
+	r.sync(syncObject)
+
+	assert(!r.bool())
+
+	pkg, name := r.p.objIdx(r.reloc(relocObj))
+	obj := pkg.Scope().Lookup(name)
+
+	targs := make([]types2.Type, r.len())
+	for i := range targs {
+		targs[i] = r.typ()
+	}
+
+	return obj, targs
+}
+
+func (pr *pkgReader2) objIdx(idx int) (*types2.Package, string) {
+	rname := pr.newReader(relocName, idx, syncObject1)
+
+	objPkg, objName := rname.qualifiedIdent()
+	assert(objName != "")
+
+	tag := codeObj(rname.code(syncCodeObj))
+
+	if tag == objStub {
+		assert(objPkg == nil)
+		return objPkg, objName
+	}
+
+	dict := pr.objDictIdx(idx)
+
+	r := pr.newReader(relocObj, idx, syncObject1)
+	r.dict = dict
+
+	objPkg.Scope().InsertLazy(objName, func() types2.Object {
+		switch tag {
+		default:
+			panic("weird")
+
+		case objAlias:
+			pos := r.pos()
+			typ := r.typ()
+			return types2.NewTypeName(pos, objPkg, objName, typ)
+
+		case objConst:
+			pos := r.pos()
+			typ, val := r.value()
+			return types2.NewConst(pos, objPkg, objName, typ, val)
+
+		case objFunc:
+			pos := r.pos()
+			tparams := r.typeParamNames()
+			sig := r.signature(nil)
+			sig.SetTParams(tparams)
+			return types2.NewFunc(pos, objPkg, objName, sig)
+
+		case objType:
+			pos := r.pos()
+
+			return types2.NewTypeNameLazy(pos, objPkg, objName, func(named *types2.Named) (tparams []*types2.TypeName, underlying types2.Type, methods []*types2.Func) {
+				tparams = r.typeParamNames()
+
+				// TODO(mdempsky): Rewrite receiver types to underlying is an
+				// Interface? The go/types importer does this (I think because
+				// unit tests expected that), but cmd/compile doesn't care
+				// about it, so maybe we can avoid worrying about that here.
+				underlying = r.typ().Underlying()
+
+				methods = make([]*types2.Func, r.len())
+				for i := range methods {
+					methods[i] = r.method()
+				}
+
+				return
+			})
+
+		case objVar:
+			pos := r.pos()
+			typ := r.typ()
+			return types2.NewVar(pos, objPkg, objName, typ)
+		}
+	})
+
+	return objPkg, objName
+}
+
+func (r *reader2) value() (types2.Type, constant.Value) {
+	r.sync(syncValue)
+	return r.typ(), r.rawValue()
+}
+
+func (pr *pkgReader2) objDictIdx(idx int) *reader2Dict {
+	r := pr.newReader(relocObjDict, idx, syncObject1)
+
+	var dict reader2Dict
+
+	if implicits := r.len(); implicits != 0 {
+		base.Fatalf("unexpected object with %v implicit type parameter(s)", implicits)
+	}
+
+	dict.bounds = make([]typeInfo, r.len())
+	for i := range dict.bounds {
+		dict.bounds[i] = r.typInfo()
+	}
+
+	dict.derived = make([]derivedInfo, r.len())
+	dict.derivedTypes = make([]types2.Type, len(dict.derived))
+	for i := range dict.derived {
+		dict.derived[i] = derivedInfo{r.reloc(relocType), r.bool()}
+	}
+
+	// function references follow, but reader2 doesn't need those
+
+	return &dict
+}
+
+func (r *reader2) typeParamNames() []*types2.TypeName {
+	r.sync(syncTypeParamNames)
+
+	// Note: This code assumes it only processes objects without
+	// implement type parameters. This is currently fine, because
+	// reader2 is only used to read in exported declarations, which are
+	// always package scoped.
+
+	if len(r.dict.bounds) == 0 {
+		return nil
+	}
+
+	// Careful: Type parameter lists may have cycles. To allow for this,
+	// we construct the type parameter list in two passes: first we
+	// create all the TypeNames and TypeParams, then we construct and
+	// set the bound type.
+
+	names := make([]*types2.TypeName, len(r.dict.bounds))
+	r.dict.tparams = make([]*types2.TypeParam, len(r.dict.bounds))
+	for i := range r.dict.bounds {
+		pos := r.pos()
+		pkg, name := r.localIdent()
+
+		names[i] = types2.NewTypeName(pos, pkg, name, nil)
+		r.dict.tparams[i] = r.p.check.NewTypeParam(names[i], nil)
+	}
+
+	for i, bound := range r.dict.bounds {
+		r.dict.tparams[i].SetConstraint(r.p.typIdx(bound, r.dict))
+	}
+
+	return names
+}
+
+func (r *reader2) method() *types2.Func {
+	r.sync(syncMethod)
+	pos := r.pos()
+	pkg, name := r.selector()
+
+	rparams := r.typeParamNames()
+	sig := r.signature(r.param())
+	sig.SetRParams(rparams)
+
+	_ = r.pos() // TODO(mdempsky): Remove; this is a hacker for linker.go.
+	return types2.NewFunc(pos, pkg, name, sig)
+}
+
+func (r *reader2) qualifiedIdent() (*types2.Package, string) { return r.ident(syncSym) }
+func (r *reader2) localIdent() (*types2.Package, string)     { return r.ident(syncLocalIdent) }
+func (r *reader2) selector() (*types2.Package, string)       { return r.ident(syncSelector) }
+
+func (r *reader2) ident(marker syncMarker) (*types2.Package, string) {
+	r.sync(marker)
+	return r.pkg(), r.string()
+}
diff --git a/src/cmd/compile/internal/noder/reloc.go b/src/cmd/compile/internal/noder/reloc.go
new file mode 100644
index 00000000000..669a6182e62
--- /dev/null
+++ b/src/cmd/compile/internal/noder/reloc.go
@@ -0,0 +1,42 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+// A reloc indicates a particular section within a unified IR export.
+//
+// TODO(mdempsky): Rename to "section" or something similar?
+type reloc int
+
+// A relocEnt (relocation entry) is an entry in an atom's local
+// reference table.
+//
+// TODO(mdempsky): Rename this too.
+type relocEnt struct {
+	kind reloc
+	idx  int
+}
+
+// Reserved indices within the meta relocation section.
+const (
+	publicRootIdx  = 0
+	privateRootIdx = 1
+)
+
+const (
+	relocString reloc = iota
+	relocMeta
+	relocPosBase
+	relocPkg
+	relocName
+	relocType
+	relocObj
+	relocObjExt
+	relocObjDict
+	relocBody
+
+	numRelocs = iota
+)
diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go
index 3ebc8dff6d8..6736f128e31 100644
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -8,21 +8,32 @@
 package noder
 
 import (
-	"bytes"
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
+	"cmd/compile/internal/objw"
+	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
+	"cmd/internal/obj"
 	"cmd/internal/src"
 	"fmt"
-	"strings"
+	"go/constant"
 )
 
-// For catching problems as we add more features
-// TODO(danscales): remove assertions or replace with base.FatalfAt()
+// Enable extra consistency checks.
+const doubleCheck = true
+
 func assert(p bool) {
-	if !p {
-		panic("assertion failed")
+	base.Assert(p)
+}
+
+// Temporary - for outputting information on derived types, dictionaries, sub-dictionaries.
+// Turn off when running tests.
+var infoPrintMode = false
+
+func infoPrint(format string, a ...interface{}) {
+	if infoPrintMode {
+		fmt.Printf(format, a...)
 	}
 }
 
@@ -32,7 +43,8 @@ func assert(p bool) {
 // encountered already or new ones that are encountered during the stenciling
 // process.
 func (g *irgen) stencil() {
-	g.target.Stencils = make(map[*types.Sym]*ir.Func)
+	g.instInfoMap = make(map[*types.Sym]*instInfo)
+	g.gfInfoMap = make(map[*types.Sym]*gfInfo)
 
 	// Instantiate the methods of instantiated generic types that we have seen so far.
 	g.instantiateMethods()
@@ -72,56 +84,138 @@ func (g *irgen) stencil() {
 		// instantiated function if it hasn't been created yet, and change
 		// to calling that function directly.
 		modified := false
-		foundFuncInst := false
+		closureRequired := false
+		// declInfo will be non-nil exactly if we are scanning an instantiated function
+		declInfo := g.instInfoMap[decl.Sym()]
+
 		ir.Visit(decl, func(n ir.Node) {
 			if n.Op() == ir.OFUNCINST {
-				// We found a function instantiation that is not
-				// immediately called.
-				foundFuncInst = true
+				// generic F, not immediately called
+				closureRequired = true
 			}
-			if n.Op() != ir.OCALL || n.(*ir.CallExpr).X.Op() != ir.OFUNCINST {
-				return
+			if (n.Op() == ir.OMETHEXPR || n.Op() == ir.OMETHVALUE) && len(deref(n.(*ir.SelectorExpr).X.Type()).RParams()) > 0 && !types.IsInterfaceMethod(n.(*ir.SelectorExpr).Selection.Type) {
+				// T.M or x.M, where T or x is generic, but not immediately
+				// called. Not necessary if the method selected is
+				// actually for an embedded interface field.
+				closureRequired = true
 			}
-			// We have found a function call using a generic function
-			// instantiation.
-			call := n.(*ir.CallExpr)
-			inst := call.X.(*ir.InstExpr)
-			st := g.getInstantiationForNode(inst)
-			// Replace the OFUNCINST with a direct reference to the
-			// new stenciled function
-			call.X = st.Nname
-			if inst.X.Op() == ir.OCALLPART {
-				// When we create an instantiation of a method
-				// call, we make it a function. So, move the
-				// receiver to be the first arg of the function
-				// call.
-				withRecv := make([]ir.Node, len(call.Args)+1)
-				dot := inst.X.(*ir.SelectorExpr)
-				withRecv[0] = dot.X
-				copy(withRecv[1:], call.Args)
-				call.Args = withRecv
+			if n.Op() == ir.OCALL && n.(*ir.CallExpr).X.Op() == ir.OFUNCINST {
+				// We have found a function call using a generic function
+				// instantiation.
+				call := n.(*ir.CallExpr)
+				inst := call.X.(*ir.InstExpr)
+				nameNode, isMeth := g.getInstNameNode(inst)
+				targs := typecheck.TypesOf(inst.Targs)
+				st := g.getInstantiation(nameNode, targs, isMeth)
+				dictValue, usingSubdict := g.getDictOrSubdict(declInfo, n, nameNode, targs, isMeth)
+				if infoPrintMode {
+					dictkind := "Main dictionary"
+					if usingSubdict {
+						dictkind = "Sub-dictionary"
+					}
+					if inst.X.Op() == ir.OMETHVALUE {
+						fmt.Printf("%s in %v at generic method call: %v - %v\n", dictkind, decl, inst.X, call)
+					} else {
+						fmt.Printf("%s in %v at generic function call: %v - %v\n", dictkind, decl, inst.X, call)
+					}
+				}
+
+				// Transform the Call now, which changes OCALL to
+				// OCALLFUNC and does typecheckaste/assignconvfn. Do
+				// it before installing the instantiation, so we are
+				// checking against non-shape param types in
+				// typecheckaste.
+				transformCall(call)
+
+				// Replace the OFUNCINST with a direct reference to the
+				// new stenciled function
+				call.X = st.Nname
+				if inst.X.Op() == ir.OMETHVALUE {
+					// When we create an instantiation of a method
+					// call, we make it a function. So, move the
+					// receiver to be the first arg of the function
+					// call.
+					call.Args.Prepend(inst.X.(*ir.SelectorExpr).X)
+				}
+
+				// Add dictionary to argument list.
+				call.Args.Prepend(dictValue)
+				modified = true
+			}
+			if n.Op() == ir.OCALLMETH && n.(*ir.CallExpr).X.Op() == ir.ODOTMETH && len(deref(n.(*ir.CallExpr).X.Type().Recv().Type).RParams()) > 0 {
+				// Method call on a generic type, which was instantiated by stenciling.
+				// Method calls on explicitly instantiated types will have an OFUNCINST
+				// and are handled above.
+				call := n.(*ir.CallExpr)
+				meth := call.X.(*ir.SelectorExpr)
+				targs := deref(meth.Type().Recv().Type).RParams()
+
+				t := meth.X.Type()
+				baseSym := deref(t).OrigSym
+				baseType := baseSym.Def.(*ir.Name).Type()
+				var gf *ir.Name
+				for _, m := range baseType.Methods().Slice() {
+					if meth.Sel == m.Sym {
+						gf = m.Nname.(*ir.Name)
+						break
+					}
+				}
+
+				// Transform the Call now, which changes OCALL
+				// to OCALLFUNC and does typecheckaste/assignconvfn.
+				transformCall(call)
+
+				st := g.getInstantiation(gf, targs, true)
+				dictValue, usingSubdict := g.getDictOrSubdict(declInfo, n, gf, targs, true)
+				// We have to be using a subdictionary, since this is
+				// a generic method call.
+				assert(usingSubdict)
+
+				// Transform to a function call, by appending the
+				// dictionary and the receiver to the args.
+				call.SetOp(ir.OCALLFUNC)
+				call.X = st.Nname
+				call.Args.Prepend(dictValue, meth.X)
+				modified = true
 			}
-			// Transform the Call now, which changes OCALL
-			// to OCALLFUNC and does typecheckaste/assignconvfn.
-			transformCall(call)
-			modified = true
 		})
 
-		// If we found an OFUNCINST without a corresponding call in the
-		// above decl, then traverse the nodes of decl again (with
+		// If we found a reference to a generic instantiation that wasn't an
+		// immediate call, then traverse the nodes of decl again (with
 		// EditChildren rather than Visit), where we actually change the
-		// OFUNCINST node to an ONAME for the instantiated function.
+		// reference to the instantiation to a closure that captures the
+		// dictionary, then does a direct call.
 		// EditChildren is more expensive than Visit, so we only do this
-		// in the infrequent case of an OFUNCINSt without a corresponding
+		// in the infrequent case of an OFUNCINST without a corresponding
 		// call.
-		if foundFuncInst {
+		if closureRequired {
+			modified = true
 			var edit func(ir.Node) ir.Node
+			var outer *ir.Func
+			if f, ok := decl.(*ir.Func); ok {
+				outer = f
+			}
 			edit = func(x ir.Node) ir.Node {
 				if x.Op() == ir.OFUNCINST {
-					st := g.getInstantiationForNode(x.(*ir.InstExpr))
-					return st.Nname
+					child := x.(*ir.InstExpr).X
+					if child.Op() == ir.OMETHEXPR || child.Op() == ir.OMETHVALUE {
+						// Call EditChildren on child (x.X),
+						// not x, so that we don't do
+						// buildClosure() on the
+						// METHEXPR/METHVALUE nodes as well.
+						ir.EditChildren(child, edit)
+						return g.buildClosure(outer, x)
+					}
 				}
 				ir.EditChildren(x, edit)
+				switch {
+				case x.Op() == ir.OFUNCINST:
+					return g.buildClosure(outer, x)
+				case (x.Op() == ir.OMETHEXPR || x.Op() == ir.OMETHVALUE) &&
+					len(deref(x.(*ir.SelectorExpr).X.Type()).RParams()) > 0 &&
+					!types.IsInterfaceMethod(x.(*ir.SelectorExpr).Selection.Type):
+					return g.buildClosure(outer, x)
+				}
 				return x
 			}
 			edit(decl)
@@ -137,104 +231,384 @@ func (g *irgen) stencil() {
 		g.instantiateMethods()
 	}
 
+	g.finalizeSyms()
 }
 
-// instantiateMethods instantiates all the methods of all fully-instantiated
-// generic types that have been added to g.instTypeList.
+// buildClosure makes a closure to implement x, a OFUNCINST or OMETHEXPR
+// of generic type. outer is the containing function (or nil if closure is
+// in a global assignment instead of a function).
+func (g *irgen) buildClosure(outer *ir.Func, x ir.Node) ir.Node {
+	pos := x.Pos()
+	var target *ir.Func   // target instantiated function/method
+	var dictValue ir.Node // dictionary to use
+	var rcvrValue ir.Node // receiver, if a method value
+	typ := x.Type()       // type of the closure
+	var outerInfo *instInfo
+	if outer != nil {
+		outerInfo = g.instInfoMap[outer.Sym()]
+	}
+	usingSubdict := false
+	valueMethod := false
+	if x.Op() == ir.OFUNCINST {
+		inst := x.(*ir.InstExpr)
+
+		// Type arguments we're instantiating with.
+		targs := typecheck.TypesOf(inst.Targs)
+
+		// Find the generic function/method.
+		var gf *ir.Name
+		if inst.X.Op() == ir.ONAME {
+			// Instantiating a generic function call.
+			gf = inst.X.(*ir.Name)
+		} else if inst.X.Op() == ir.OMETHVALUE {
+			// Instantiating a method value x.M.
+			se := inst.X.(*ir.SelectorExpr)
+			rcvrValue = se.X
+			gf = se.Selection.Nname.(*ir.Name)
+		} else {
+			panic("unhandled")
+		}
+
+		// target is the instantiated function we're trying to call.
+		// For functions, the target expects a dictionary as its first argument.
+		// For method values, the target expects a dictionary and the receiver
+		// as its first two arguments.
+		// dictValue is the value to use for the dictionary argument.
+		target = g.getInstantiation(gf, targs, rcvrValue != nil)
+		dictValue, usingSubdict = g.getDictOrSubdict(outerInfo, x, gf, targs, rcvrValue != nil)
+		if infoPrintMode {
+			dictkind := "Main dictionary"
+			if usingSubdict {
+				dictkind = "Sub-dictionary"
+			}
+			if rcvrValue == nil {
+				fmt.Printf("%s in %v for generic function value %v\n", dictkind, outer, inst.X)
+			} else {
+				fmt.Printf("%s in %v for generic method value %v\n", dictkind, outer, inst.X)
+			}
+		}
+	} else { // ir.OMETHEXPR or ir.METHVALUE
+		// Method expression T.M where T is a generic type.
+		se := x.(*ir.SelectorExpr)
+		targs := deref(se.X.Type()).RParams()
+		if len(targs) == 0 {
+			panic("bad")
+		}
+		if x.Op() == ir.OMETHVALUE {
+			rcvrValue = se.X
+		}
+
+		// se.X.Type() is the top-level type of the method expression. To
+		// correctly handle method expressions involving embedded fields,
+		// look up the generic method below using the type of the receiver
+		// of se.Selection, since that will be the type that actually has
+		// the method.
+		recv := deref(se.Selection.Type.Recv().Type)
+		baseType := recv.OrigSym.Def.Type()
+		var gf *ir.Name
+		for _, m := range baseType.Methods().Slice() {
+			if se.Sel == m.Sym {
+				gf = m.Nname.(*ir.Name)
+				break
+			}
+		}
+		if !gf.Type().Recv().Type.IsPtr() {
+			// Remember if value method, so we can detect (*T).M case.
+			valueMethod = true
+		}
+		target = g.getInstantiation(gf, targs, true)
+		dictValue, usingSubdict = g.getDictOrSubdict(outerInfo, x, gf, targs, true)
+		if infoPrintMode {
+			dictkind := "Main dictionary"
+			if usingSubdict {
+				dictkind = "Sub-dictionary"
+			}
+			fmt.Printf("%s in %v for method expression %v\n", dictkind, outer, x)
+		}
+	}
+
+	// Build a closure to implement a function instantiation.
+	//
+	//   func f[T any] (int, int) (int, int) { ...whatever... }
+	//
+	// Then any reference to f[int] not directly called gets rewritten to
+	//
+	//   .dictN := ... dictionary to use ...
+	//   func(a0, a1 int) (r0, r1 int) {
+	//     return .inst.f[int](.dictN, a0, a1)
+	//   }
+	//
+	// Similarly for method expressions,
+	//
+	//   type g[T any] ....
+	//   func (rcvr g[T]) f(a0, a1 int) (r0, r1 int) { ... }
+	//
+	// Any reference to g[int].f not directly called gets rewritten to
+	//
+	//   .dictN := ... dictionary to use ...
+	//   func(rcvr g[int], a0, a1 int) (r0, r1 int) {
+	//     return .inst.g[int].f(.dictN, rcvr, a0, a1)
+	//   }
+	//
+	// Also method values
+	//
+	//   var x g[int]
+	//
+	// Any reference to x.f not directly called gets rewritten to
+	//
+	//   .dictN := ... dictionary to use ...
+	//   x2 := x
+	//   func(a0, a1 int) (r0, r1 int) {
+	//     return .inst.g[int].f(.dictN, x2, a0, a1)
+	//   }
+
+	// Make a new internal function.
+	fn, formalParams, formalResults := startClosure(pos, outer, typ)
+
+	// This is the dictionary we want to use.
+	// It may be a constant, or it may be a dictionary acquired from the outer function's dictionary.
+	// For the latter, dictVar is a variable in the outer function's scope, set to the subdictionary
+	// read from the outer function's dictionary.
+	var dictVar *ir.Name
+	var dictAssign *ir.AssignStmt
+	if outer != nil {
+		// Note: for now this is a compile-time constant, so we don't really need a closure
+		// to capture it (a wrapper function would work just as well). But eventually it
+		// will be a read of a subdictionary from the parent dictionary.
+		dictVar = ir.NewNameAt(pos, typecheck.LookupNum(".dict", g.dnum))
+		g.dnum++
+		dictVar.Class = ir.PAUTO
+		typed(types.Types[types.TUINTPTR], dictVar)
+		dictVar.Curfn = outer
+		dictAssign = ir.NewAssignStmt(pos, dictVar, dictValue)
+		dictAssign.SetTypecheck(1)
+		dictVar.Defn = dictAssign
+		outer.Dcl = append(outer.Dcl, dictVar)
+	}
+	// assign the receiver to a temporary.
+	var rcvrVar *ir.Name
+	var rcvrAssign ir.Node
+	if rcvrValue != nil {
+		rcvrVar = ir.NewNameAt(pos, typecheck.LookupNum(".rcvr", g.dnum))
+		g.dnum++
+		rcvrVar.Class = ir.PAUTO
+		typed(rcvrValue.Type(), rcvrVar)
+		rcvrVar.Curfn = outer
+		rcvrAssign = ir.NewAssignStmt(pos, rcvrVar, rcvrValue)
+		rcvrAssign.SetTypecheck(1)
+		rcvrVar.Defn = rcvrAssign
+		outer.Dcl = append(outer.Dcl, rcvrVar)
+	}
+
+	// Build body of closure. This involves just calling the wrapped function directly
+	// with the additional dictionary argument.
+
+	// First, figure out the dictionary argument.
+	var dict2Var ir.Node
+	if usingSubdict {
+		// Capture sub-dictionary calculated in the outer function
+		dict2Var = ir.CaptureName(pos, fn, dictVar)
+		typed(types.Types[types.TUINTPTR], dict2Var)
+	} else {
+		// Static dictionary, so can be used directly in the closure
+		dict2Var = dictValue
+	}
+	// Also capture the receiver variable.
+	var rcvr2Var *ir.Name
+	if rcvrValue != nil {
+		rcvr2Var = ir.CaptureName(pos, fn, rcvrVar)
+	}
+
+	// Build arguments to call inside the closure.
+	var args []ir.Node
+
+	// First the dictionary argument.
+	args = append(args, dict2Var)
+	// Then the receiver.
+	if rcvrValue != nil {
+		args = append(args, rcvr2Var)
+	}
+	// Then all the other arguments (including receiver for method expressions).
+	for i := 0; i < typ.NumParams(); i++ {
+		if x.Op() == ir.OMETHEXPR && i == 0 {
+			// If we are doing a method expression, we need to
+			// explicitly traverse any embedded fields in the receiver
+			// argument in order to call the method instantiation.
+			arg0 := formalParams[0].Nname.(ir.Node)
+			arg0 = typecheck.AddImplicitDots(ir.NewSelectorExpr(base.Pos, ir.OXDOT, arg0, x.(*ir.SelectorExpr).Sel)).X
+			if valueMethod && arg0.Type().IsPtr() {
+				// For handling the (*T).M case: if we have a pointer
+				// receiver after following all the embedded fields,
+				// but it's a value method, add a star operator.
+				arg0 = ir.NewStarExpr(arg0.Pos(), arg0)
+			}
+			args = append(args, arg0)
+		} else {
+			args = append(args, formalParams[i].Nname.(*ir.Name))
+		}
+	}
+
+	// Build call itself.
+	var innerCall ir.Node = ir.NewCallExpr(pos, ir.OCALL, target.Nname, args)
+	if len(formalResults) > 0 {
+		innerCall = ir.NewReturnStmt(pos, []ir.Node{innerCall})
+	}
+	// Finish building body of closure.
+	ir.CurFunc = fn
+	// TODO: set types directly here instead of using typecheck.Stmt
+	typecheck.Stmt(innerCall)
+	ir.CurFunc = nil
+	fn.Body = []ir.Node{innerCall}
+
+	// We're all done with the captured dictionary (and receiver, for method values).
+	ir.FinishCaptureNames(pos, outer, fn)
+
+	// Make a closure referencing our new internal function.
+	c := ir.UseClosure(fn.OClosure, g.target)
+	var init []ir.Node
+	if outer != nil {
+		init = append(init, dictAssign)
+	}
+	if rcvrValue != nil {
+		init = append(init, rcvrAssign)
+	}
+	return ir.InitExpr(init, c)
+}
+
+// instantiateMethods instantiates all the methods (and associated dictionaries) of
+// all fully-instantiated generic types that have been added to g.instTypeList.
 func (g *irgen) instantiateMethods() {
 	for i := 0; i < len(g.instTypeList); i++ {
 		typ := g.instTypeList[i]
-		// Get the base generic type by looking up the symbol of the
-		// generic (uninstantiated) name.
-		baseSym := typ.Sym().Pkg.Lookup(genericTypeName(typ.Sym()))
+		assert(!typ.HasShape())
+		// Mark runtime type as needed, since this ensures that the
+		// compiler puts out the needed DWARF symbols, when this
+		// instantiated type has a different package from the local
+		// package.
+		typecheck.NeedRuntimeType(typ)
+		// Lookup the method on the base generic type, since methods may
+		// not be set on imported instantiated types.
+		baseSym := typ.OrigSym
 		baseType := baseSym.Def.(*ir.Name).Type()
-		for j, m := range typ.Methods().Slice() {
-			name := m.Nname.(*ir.Name)
-			targs := make([]ir.Node, len(typ.RParams()))
-			for k, targ := range typ.RParams() {
-				targs[k] = ir.TypeNode(targ)
-			}
+		for j, _ := range typ.Methods().Slice() {
 			baseNname := baseType.Methods().Slice()[j].Nname.(*ir.Name)
-			name.Func = g.getInstantiation(baseNname, targs, true)
+			// Eagerly generate the instantiations and dictionaries that implement these methods.
+			// We don't use the instantiations here, just generate them (and any
+			// further instantiations those generate, etc.).
+			// Note that we don't set the Func for any methods on instantiated
+			// types. Their signatures don't match so that would be confusing.
+			// Direct method calls go directly to the instantiations, implemented above.
+			// Indirect method calls use wrappers generated in reflectcall. Those wrappers
+			// will use these instantiations if they are needed (for interface tables or reflection).
+			_ = g.getInstantiation(baseNname, typ.RParams(), true)
+			_ = g.getDictionarySym(baseNname, typ.RParams(), true)
 		}
 	}
 	g.instTypeList = nil
 
 }
 
-// genericSym returns the name of the base generic type for the type named by
-// sym. It simply returns the name obtained by removing everything after the
-// first bracket ("[").
-func genericTypeName(sym *types.Sym) string {
-	return sym.Name[0:strings.Index(sym.Name, "[")]
-}
-
-// getInstantiationForNode returns the function/method instantiation for a
-// InstExpr node inst.
-func (g *irgen) getInstantiationForNode(inst *ir.InstExpr) *ir.Func {
+// getInstNameNode returns the name node for the method or function being instantiated, and a bool which is true if a method is being instantiated.
+func (g *irgen) getInstNameNode(inst *ir.InstExpr) (*ir.Name, bool) {
 	if meth, ok := inst.X.(*ir.SelectorExpr); ok {
-		return g.getInstantiation(meth.Selection.Nname.(*ir.Name), inst.Targs, true)
+		return meth.Selection.Nname.(*ir.Name), true
 	} else {
-		return g.getInstantiation(inst.X.(*ir.Name), inst.Targs, false)
+		return inst.X.(*ir.Name), false
 	}
 }
 
-// getInstantiation gets the instantiantion of the function or method nameNode
-// with the type arguments targs. If the instantiated function is not already
+// getDictOrSubdict returns, for a method/function call or reference (node n) in an
+// instantiation (described by instInfo), a node which is accessing a sub-dictionary
+// or main/static dictionary, as needed, and also returns a boolean indicating if a
+// sub-dictionary was accessed. nameNode is the particular function or method being
+// called/referenced, and targs are the type arguments.
+func (g *irgen) getDictOrSubdict(declInfo *instInfo, n ir.Node, nameNode *ir.Name, targs []*types.Type, isMeth bool) (ir.Node, bool) {
+	var dict ir.Node
+	usingSubdict := false
+	if declInfo != nil {
+		// Get the dictionary arg via sub-dictionary reference
+		entry, ok := declInfo.dictEntryMap[n]
+		// If the entry is not found, it may be that this node did not have
+		// any type args that depend on type params, so we need a main
+		// dictionary, not a sub-dictionary.
+		if ok {
+			dict = getDictionaryEntry(n.Pos(), declInfo.dictParam, entry, declInfo.dictLen)
+			usingSubdict = true
+		}
+	}
+	if !usingSubdict {
+		dict = g.getDictionaryValue(nameNode, targs, isMeth)
+	}
+	return dict, usingSubdict
+}
+
+// checkFetchBody checks if a generic body can be fetched, but hasn't been loaded
+// yet. If so, it imports the body.
+func checkFetchBody(nameNode *ir.Name) {
+	if nameNode.Func.Body == nil && nameNode.Func.Inl != nil {
+		// If there is no body yet but Func.Inl exists, then we can can
+		// import the whole generic body.
+		assert(nameNode.Func.Inl.Cost == 1 && nameNode.Sym().Pkg != types.LocalPkg)
+		typecheck.ImportBody(nameNode.Func)
+		assert(nameNode.Func.Inl.Body != nil)
+		nameNode.Func.Body = nameNode.Func.Inl.Body
+		nameNode.Func.Dcl = nameNode.Func.Inl.Dcl
+	}
+}
+
+// getInstantiation gets the instantiantion and dictionary of the function or method nameNode
+// with the type arguments shapes. If the instantiated function is not already
 // cached, then it calls genericSubst to create the new instantiation.
-func (g *irgen) getInstantiation(nameNode *ir.Name, targs []ir.Node, isMeth bool) *ir.Func {
-	sym := makeInstName(nameNode.Sym(), targs, isMeth)
-	st := g.target.Stencils[sym]
-	if st == nil {
+func (g *irgen) getInstantiation(nameNode *ir.Name, shapes []*types.Type, isMeth bool) *ir.Func {
+	checkFetchBody(nameNode)
+
+	// Convert any non-shape type arguments to their shape, so we can reduce the
+	// number of instantiations we have to generate. You can actually have a mix
+	// of shape and non-shape arguments, because of inferred or explicitly
+	// specified concrete type args.
+	var s1 []*types.Type
+	for i, t := range shapes {
+		if !t.HasShape() {
+			if s1 == nil {
+				s1 = make([]*types.Type, len(shapes))
+				copy(s1[0:i], shapes[0:i])
+			}
+			s1[i] = typecheck.Shapify(t)
+		} else if s1 != nil {
+			s1[i] = shapes[i]
+		}
+	}
+	if s1 != nil {
+		shapes = s1
+	}
+
+	sym := typecheck.MakeInstName(nameNode.Sym(), shapes, isMeth)
+	info := g.instInfoMap[sym]
+	if info == nil {
 		// If instantiation doesn't exist yet, create it and add
 		// to the list of decls.
-		st = g.genericSubst(sym, nameNode, targs, isMeth)
-		g.target.Stencils[sym] = st
+		gfInfo := g.getGfInfo(nameNode)
+		info = &instInfo{
+			gf:            nameNode,
+			gfInfo:        gfInfo,
+			startSubDict:  len(shapes) + len(gfInfo.derivedTypes),
+			startItabConv: len(shapes) + len(gfInfo.derivedTypes) + len(gfInfo.subDictCalls),
+			dictLen:       len(shapes) + len(gfInfo.derivedTypes) + len(gfInfo.subDictCalls) + len(gfInfo.itabConvs),
+			dictEntryMap:  make(map[ir.Node]int),
+		}
+		// genericSubst fills in info.dictParam and info.dictEntryMap.
+		st := g.genericSubst(sym, nameNode, shapes, isMeth, info)
+		info.fun = st
+		g.instInfoMap[sym] = info
+		// This ensures that the linker drops duplicates of this instantiation.
+		// All just works!
+		st.SetDupok(true)
 		g.target.Decls = append(g.target.Decls, st)
 		if base.Flag.W > 1 {
 			ir.Dump(fmt.Sprintf("\nstenciled %v", st), st)
 		}
 	}
-	return st
-}
-
-// makeInstName makes the unique name for a stenciled generic function or method,
-// based on the name of the function fy=nsym and the targs. It replaces any
-// existing bracket type list in the name. makeInstName asserts that fnsym has
-// brackets in its name if and only if hasBrackets is true.
-// TODO(danscales): remove the assertions and the hasBrackets argument later.
-//
-// Names of declared generic functions have no brackets originally, so hasBrackets
-// should be false. Names of generic methods already have brackets, since the new
-// type parameter is specified in the generic type of the receiver (e.g. func
-// (func (v *value[T]).set(...) { ... } has the original name (*value[T]).set.
-//
-// The standard naming is something like: 'genFn[int,bool]' for functions and
-// '(*genType[int,bool]).methodName' for methods
-func makeInstName(fnsym *types.Sym, targs []ir.Node, hasBrackets bool) *types.Sym {
-	b := bytes.NewBufferString("")
-	name := fnsym.Name
-	i := strings.Index(name, "[")
-	assert(hasBrackets == (i >= 0))
-	if i >= 0 {
-		b.WriteString(name[0:i])
-	} else {
-		b.WriteString(name)
-	}
-	b.WriteString("[")
-	for i, targ := range targs {
-		if i > 0 {
-			b.WriteString(",")
-		}
-		b.WriteString(targ.Type().String())
-	}
-	b.WriteString("]")
-	if i >= 0 {
-		i2 := strings.Index(name[i:], "]")
-		assert(i2 >= 0)
-		b.WriteString(name[i+i2+1:])
-	}
-	return typecheck.Lookup(b.String())
+	return info.fun
 }
 
 // Struct containing info needed for doing the substitution as we create the
@@ -243,32 +617,30 @@ type subster struct {
 	g        *irgen
 	isMethod bool     // If a method is being instantiated
 	newf     *ir.Func // Func node for the new stenciled function
-	tparams  []*types.Field
-	targs    []ir.Node
-	// The substitution map from name nodes in the generic function to the
-	// name nodes in the new stenciled function.
-	vars map[*ir.Name]*ir.Name
+	ts       typecheck.Tsubster
+	info     *instInfo // Place to put extra info in the instantiation
 }
 
 // genericSubst returns a new function with name newsym. The function is an
 // instantiation of a generic function or method specified by namedNode with type
-// args targs. For a method with a generic receiver, it returns an instantiated
-// function type where the receiver becomes the first parameter. Otherwise the
-// instantiated method would still need to be transformed by later compiler
-// phases.
-func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []ir.Node, isMethod bool) *ir.Func {
-	var tparams []*types.Field
+// args shapes. For a method with a generic receiver, it returns an instantiated
+// function type where the receiver becomes the first parameter. For either a generic
+// method or function, a dictionary parameter is the added as the very first
+// parameter. genericSubst fills in info.dictParam and info.dictEntryMap.
+func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, shapes []*types.Type, isMethod bool, info *instInfo) *ir.Func {
+	var tparams []*types.Type
 	if isMethod {
 		// Get the type params from the method receiver (after skipping
 		// over any pointer)
 		recvType := nameNode.Type().Recv().Type
 		recvType = deref(recvType)
-		tparams = make([]*types.Field, len(recvType.RParams()))
-		for i, rparam := range recvType.RParams() {
-			tparams[i] = types.NewField(src.NoXPos, nil, rparam)
-		}
+		tparams = recvType.RParams()
 	} else {
-		tparams = nameNode.Type().TParams().Fields().Slice()
+		fields := nameNode.Type().TParams().Fields().Slice()
+		tparams = make([]*types.Type, len(fields))
+		for i, f := range fields {
+			tparams[i] = f.Type
+		}
 	}
 	gf := nameNode.Func
 	// Pos of the instantiated function is same as the generic function
@@ -283,78 +655,214 @@ func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []ir.No
 	// depend on ir.CurFunc being set.
 	ir.CurFunc = newf
 
-	assert(len(tparams) == len(targs))
+	assert(len(tparams) == len(shapes))
 
 	subst := &subster{
 		g:        g,
 		isMethod: isMethod,
 		newf:     newf,
-		tparams:  tparams,
-		targs:    targs,
-		vars:     make(map[*ir.Name]*ir.Name),
+		info:     info,
+		ts: typecheck.Tsubster{
+			Tparams: tparams,
+			Targs:   shapes,
+			Vars:    make(map[*ir.Name]*ir.Name),
+		},
 	}
 
-	newf.Dcl = make([]*ir.Name, len(gf.Dcl))
-	for i, n := range gf.Dcl {
-		newf.Dcl[i] = subst.node(n).(*ir.Name)
-	}
+	newf.Dcl = make([]*ir.Name, 0, len(gf.Dcl)+1)
 
-	// Ugly: we have to insert the Name nodes of the parameters/results into
+	// Create the needed dictionary param
+	dictionarySym := newsym.Pkg.Lookup(".dict")
+	dictionaryType := types.Types[types.TUINTPTR]
+	dictionaryName := ir.NewNameAt(gf.Pos(), dictionarySym)
+	typed(dictionaryType, dictionaryName)
+	dictionaryName.Class = ir.PPARAM
+	dictionaryName.Curfn = newf
+	newf.Dcl = append(newf.Dcl, dictionaryName)
+	for _, n := range gf.Dcl {
+		if n.Sym().Name == ".dict" {
+			panic("already has dictionary")
+		}
+		newf.Dcl = append(newf.Dcl, subst.localvar(n))
+	}
+	dictionaryArg := types.NewField(gf.Pos(), dictionarySym, dictionaryType)
+	dictionaryArg.Nname = dictionaryName
+	info.dictParam = dictionaryName
+
+	// We add the dictionary as the first parameter in the function signature.
+	// We also transform a method type to the corresponding function type
+	// (make the receiver be the next parameter after the dictionary).
+	oldt := nameNode.Type()
+	var args []*types.Field
+	args = append(args, dictionaryArg)
+	args = append(args, oldt.Recvs().FieldSlice()...)
+	args = append(args, oldt.Params().FieldSlice()...)
+
+	// Replace the types in the function signature via subst.fields.
+	// Ugly: also, we have to insert the Name nodes of the parameters/results into
 	// the function type. The current function type has no Nname fields set,
 	// because it came via conversion from the types2 type.
-	oldt := nameNode.Type()
-	// We also transform a generic method type to the corresponding
-	// instantiated function type where the receiver is the first parameter.
 	newt := types.NewSignature(oldt.Pkg(), nil, nil,
-		subst.fields(ir.PPARAM, append(oldt.Recvs().FieldSlice(), oldt.Params().FieldSlice()...), newf.Dcl),
+		subst.fields(ir.PPARAM, args, newf.Dcl),
 		subst.fields(ir.PPARAMOUT, oldt.Results().FieldSlice(), newf.Dcl))
 
-	newf.Nname.SetType(newt)
+	typed(newt, newf.Nname)
 	ir.MarkFunc(newf.Nname)
 	newf.SetTypecheck(1)
-	newf.Nname.SetTypecheck(1)
 
 	// Make sure name/type of newf is set before substituting the body.
 	newf.Body = subst.list(gf.Body)
+
+	// Add code to check that the dictionary is correct.
+	// TODO: must be adjusted to deal with shapes, but will go away soon when we move
+	// to many->1 shape to concrete mapping.
+	// newf.Body.Prepend(subst.checkDictionary(dictionaryName, shapes)...)
+
 	ir.CurFunc = savef
+	// Add any new, fully instantiated types seen during the substitution to
+	// g.instTypeList.
+	g.instTypeList = append(g.instTypeList, subst.ts.InstTypeList...)
+
+	if doubleCheck {
+		okConvs := map[ir.Node]bool{}
+		ir.Visit(newf, func(n ir.Node) {
+			if n.Op() == ir.OIDATA {
+				// IDATA(OCONVIFACE(x)) is ok, as we don't use the type of x.
+				// TODO: use some other op besides OCONVIFACE. ONEW might work
+				// (with appropriate direct vs. indirect interface cases).
+				okConvs[n.(*ir.UnaryExpr).X] = true
+			}
+			if n.Op() == ir.OCONVIFACE && !okConvs[n] {
+				c := n.(*ir.ConvExpr)
+				if c.X.Type().HasShape() {
+					ir.Dump("BAD FUNCTION", newf)
+					ir.Dump("BAD CONVERSION", c)
+					base.Fatalf("converting shape type to interface")
+				}
+			}
+		})
+	}
 
 	return newf
 }
 
-// node is like DeepCopy(), but creates distinct ONAME nodes, and also descends
-// into closures. It substitutes type arguments for type parameters in all the new
-// nodes.
+// localvar creates a new name node for the specified local variable and enters it
+// in subst.vars. It substitutes type arguments for type parameters in the type of
+// name as needed.
+func (subst *subster) localvar(name *ir.Name) *ir.Name {
+	m := ir.NewNameAt(name.Pos(), name.Sym())
+	if name.IsClosureVar() {
+		m.SetIsClosureVar(true)
+	}
+	m.SetType(subst.ts.Typ(name.Type()))
+	m.BuiltinOp = name.BuiltinOp
+	m.Curfn = subst.newf
+	m.Class = name.Class
+	assert(name.Class != ir.PEXTERN && name.Class != ir.PFUNC)
+	m.Func = name.Func
+	subst.ts.Vars[name] = m
+	m.SetTypecheck(1)
+	return m
+}
+
+// checkDictionary returns code that does runtime consistency checks
+// between the dictionary and the types it should contain.
+func (subst *subster) checkDictionary(name *ir.Name, targs []*types.Type) (code []ir.Node) {
+	if false {
+		return // checking turned off
+	}
+	// TODO: when moving to GCshape, this test will become harder. Call into
+	// runtime to check the expected shape is correct?
+	pos := name.Pos()
+	// Convert dictionary to *[N]uintptr
+	d := ir.NewConvExpr(pos, ir.OCONVNOP, types.Types[types.TUNSAFEPTR], name)
+	d.SetTypecheck(1)
+	d = ir.NewConvExpr(pos, ir.OCONVNOP, types.NewArray(types.Types[types.TUINTPTR], int64(len(targs))).PtrTo(), d)
+	d.SetTypecheck(1)
+	types.CheckSize(d.Type().Elem())
+
+	// Check that each type entry in the dictionary is correct.
+	for i, t := range targs {
+		if t.HasShape() {
+			// Check the concrete type, not the shape type.
+			base.Fatalf("shape type in dictionary %s %+v\n", name.Sym().Name, t)
+		}
+		want := reflectdata.TypePtr(t)
+		typed(types.Types[types.TUINTPTR], want)
+		deref := ir.NewStarExpr(pos, d)
+		typed(d.Type().Elem(), deref)
+		idx := ir.NewConstExpr(constant.MakeUint64(uint64(i)), name) // TODO: what to set orig to?
+		typed(types.Types[types.TUINTPTR], idx)
+		got := ir.NewIndexExpr(pos, deref, idx)
+		typed(types.Types[types.TUINTPTR], got)
+		cond := ir.NewBinaryExpr(pos, ir.ONE, want, got)
+		typed(types.Types[types.TBOOL], cond)
+		panicArg := ir.NewNilExpr(pos)
+		typed(types.NewInterface(types.LocalPkg, nil), panicArg)
+		then := ir.NewUnaryExpr(pos, ir.OPANIC, panicArg)
+		then.SetTypecheck(1)
+		x := ir.NewIfStmt(pos, cond, []ir.Node{then}, nil)
+		x.SetTypecheck(1)
+		code = append(code, x)
+	}
+	return
+}
+
+// getDictionaryEntry gets the i'th entry in the dictionary dict.
+func getDictionaryEntry(pos src.XPos, dict *ir.Name, i int, size int) ir.Node {
+	// Convert dictionary to *[N]uintptr
+	// All entries in the dictionary are pointers. They all point to static data, though, so we
+	// treat them as uintptrs so the GC doesn't need to keep track of them.
+	d := ir.NewConvExpr(pos, ir.OCONVNOP, types.Types[types.TUNSAFEPTR], dict)
+	d.SetTypecheck(1)
+	d = ir.NewConvExpr(pos, ir.OCONVNOP, types.NewArray(types.Types[types.TUINTPTR], int64(size)).PtrTo(), d)
+	d.SetTypecheck(1)
+	types.CheckSize(d.Type().Elem())
+
+	// Load entry i out of the dictionary.
+	deref := ir.NewStarExpr(pos, d)
+	typed(d.Type().Elem(), deref)
+	idx := ir.NewConstExpr(constant.MakeUint64(uint64(i)), dict) // TODO: what to set orig to?
+	typed(types.Types[types.TUINTPTR], idx)
+	r := ir.NewIndexExpr(pos, deref, idx)
+	typed(types.Types[types.TUINTPTR], r)
+	return r
+}
+
+// getDictionaryType returns a *runtime._type from the dictionary entry i (which
+// refers to a type param or a derived type that uses type params). It uses the
+// specified dictionary dictParam, rather than the one in info.dictParam.
+func getDictionaryType(info *instInfo, dictParam *ir.Name, pos src.XPos, i int) ir.Node {
+	if i < 0 || i >= info.startSubDict {
+		base.Fatalf(fmt.Sprintf("bad dict index %d", i))
+	}
+
+	r := getDictionaryEntry(pos, info.dictParam, i, info.startSubDict)
+	// change type of retrieved dictionary entry to *byte, which is the
+	// standard typing of a *runtime._type in the compiler
+	typed(types.Types[types.TUINT8].PtrTo(), r)
+	return r
+}
+
+// node is like DeepCopy(), but substitutes ONAME nodes based on subst.ts.vars, and
+// also descends into closures. It substitutes type arguments for type parameters
+// in all the new nodes.
 func (subst *subster) node(n ir.Node) ir.Node {
 	// Use closure to capture all state needed by the ir.EditChildren argument.
 	var edit func(ir.Node) ir.Node
 	edit = func(x ir.Node) ir.Node {
 		switch x.Op() {
 		case ir.OTYPE:
-			return ir.TypeNode(subst.typ(x.Type()))
+			return ir.TypeNode(subst.ts.Typ(x.Type()))
 
 		case ir.ONAME:
-			name := x.(*ir.Name)
-			if v := subst.vars[name]; v != nil {
+			if v := subst.ts.Vars[x.(*ir.Name)]; v != nil {
 				return v
 			}
-			m := ir.NewNameAt(name.Pos(), name.Sym())
-			if name.IsClosureVar() {
-				m.SetIsClosureVar(true)
-			}
-			t := x.Type()
-			if t == nil {
-				assert(name.BuiltinOp != 0)
-			} else {
-				newt := subst.typ(t)
-				m.SetType(newt)
-			}
-			m.BuiltinOp = name.BuiltinOp
-			m.Curfn = subst.newf
-			m.Class = name.Class
-			m.Func = name.Func
-			subst.vars[name] = m
-			m.SetTypecheck(1)
-			return m
+			return x
+		case ir.ONONAME:
+			// This handles the identifier in a type switch guard
+			fallthrough
 		case ir.OLITERAL, ir.ONIL:
 			if x.Sym() != nil {
 				return x
@@ -369,55 +877,66 @@ func (subst *subster) node(n ir.Node) ir.Node {
 				// an error.
 				_, isCallExpr := m.(*ir.CallExpr)
 				_, isStructKeyExpr := m.(*ir.StructKeyExpr)
-				if !isCallExpr && !isStructKeyExpr && x.Op() != ir.OPANIC &&
+				_, isKeyExpr := m.(*ir.KeyExpr)
+				if !isCallExpr && !isStructKeyExpr && !isKeyExpr && x.Op() != ir.OPANIC &&
 					x.Op() != ir.OCLOSE {
 					base.Fatalf(fmt.Sprintf("Nil type for %v", x))
 				}
 			} else if x.Op() != ir.OCLOSURE {
-				m.SetType(subst.typ(x.Type()))
+				m.SetType(subst.ts.Typ(x.Type()))
 			}
 		}
+
+		for i, de := range subst.info.gfInfo.subDictCalls {
+			if de == x {
+				// Remember the dictionary entry associated with this
+				// node in the instantiated function
+				// TODO: make sure this remains correct with respect to the
+				// transformations below.
+				subst.info.dictEntryMap[m] = subst.info.startSubDict + i
+				break
+			}
+		}
+
 		ir.EditChildren(m, edit)
 
-		if x.Typecheck() == 3 {
-			// These are nodes whose transforms were delayed until
-			// their instantiated type was known.
-			m.SetTypecheck(1)
-			if typecheck.IsCmp(x.Op()) {
-				transformCompare(m.(*ir.BinaryExpr))
-			} else {
-				switch x.Op() {
-				case ir.OSLICE, ir.OSLICE3:
-					transformSlice(m.(*ir.SliceExpr))
+		m.SetTypecheck(1)
+		if typecheck.IsCmp(x.Op()) {
+			transformCompare(m.(*ir.BinaryExpr))
+		} else {
+			switch x.Op() {
+			case ir.OSLICE, ir.OSLICE3:
+				transformSlice(m.(*ir.SliceExpr))
 
-				case ir.OADD:
-					m = transformAdd(m.(*ir.BinaryExpr))
+			case ir.OADD:
+				m = transformAdd(m.(*ir.BinaryExpr))
 
-				case ir.OINDEX:
-					transformIndex(m.(*ir.IndexExpr))
+			case ir.OINDEX:
+				transformIndex(m.(*ir.IndexExpr))
 
-				case ir.OAS2:
-					as2 := m.(*ir.AssignListStmt)
-					transformAssign(as2, as2.Lhs, as2.Rhs)
+			case ir.OAS2:
+				as2 := m.(*ir.AssignListStmt)
+				transformAssign(as2, as2.Lhs, as2.Rhs)
 
-				case ir.OAS:
-					as := m.(*ir.AssignStmt)
+			case ir.OAS:
+				as := m.(*ir.AssignStmt)
+				if as.Y != nil {
+					// transformAssign doesn't handle the case
+					// of zeroing assignment of a dcl (rhs[0] is nil).
 					lhs, rhs := []ir.Node{as.X}, []ir.Node{as.Y}
 					transformAssign(as, lhs, rhs)
-
-				case ir.OASOP:
-					as := m.(*ir.AssignOpStmt)
-					transformCheckAssign(as, as.X)
-
-				case ir.ORETURN:
-					transformReturn(m.(*ir.ReturnStmt))
-
-				case ir.OSEND:
-					transformSend(m.(*ir.SendStmt))
-
-				default:
-					base.Fatalf("Unexpected node with Typecheck() == 3")
 				}
+
+			case ir.OASOP:
+				as := m.(*ir.AssignOpStmt)
+				transformCheckAssign(as, as.X)
+
+			case ir.ORETURN:
+				transformReturn(m.(*ir.ReturnStmt))
+
+			case ir.OSEND:
+				transformSend(m.(*ir.SendStmt))
+
 			}
 		}
 
@@ -445,11 +964,40 @@ func (subst *subster) node(n ir.Node) ir.Node {
 			// instantiated receiver type. We need to do this now,
 			// since the access/selection to the method for the real
 			// type is very different from the selection for the type
-			// param. m will be transformed to an OCALLPART node. It
+			// param. m will be transformed to an OMETHVALUE node. It
 			// will be transformed to an ODOTMETH or ODOTINTER node if
 			// we find in the OCALL case below that the method value
 			// is actually called.
-			transformDot(m.(*ir.SelectorExpr), false)
+			mse := m.(*ir.SelectorExpr)
+			if src := mse.X.Type(); src.IsShape() {
+				// The only dot on a shape type value are methods.
+				if mse.X.Op() == ir.OTYPE {
+					// Method expression T.M
+					m = subst.g.buildClosure2(subst, m, x)
+					// No need for transformDot - buildClosure2 has already
+					// transformed to OCALLINTER/ODOTINTER.
+				} else {
+					// Implement x.M as a conversion-to-bound-interface
+					//  1) convert x to the bound interface
+					//  2) call M on that interface
+					gsrc := x.(*ir.SelectorExpr).X.Type()
+					bound := gsrc.Bound()
+					dst := bound
+					if dst.HasTParam() {
+						dst = subst.ts.Typ(dst)
+					}
+					if src.IsInterface() {
+						// If type arg is an interface (unusual case),
+						// we do a type assert to the type bound.
+						mse.X = assertToBound(subst.info, subst.info.dictParam, m.Pos(), mse.X, bound, dst)
+					} else {
+						mse.X = convertUsingDictionary(subst.info, subst.info.dictParam, m.Pos(), mse.X, x, dst, gsrc)
+					}
+					transformDot(mse, false)
+				}
+			} else {
+				transformDot(mse, false)
+			}
 			m.SetTypecheck(1)
 
 		case ir.OCALL:
@@ -458,9 +1006,11 @@ func (subst *subster) node(n ir.Node) ir.Node {
 			case ir.OTYPE:
 				// Transform the conversion, now that we know the
 				// type argument.
-				m = transformConvCall(m.(*ir.CallExpr))
+				m = transformConvCall(call)
+				// CONVIFACE transformation was already done in node2
+				assert(m.Op() != ir.OCONVIFACE)
 
-			case ir.OCALLPART:
+			case ir.OMETHVALUE, ir.OMETHEXPR:
 				// Redo the transformation of OXDOT, now that we
 				// know the method value is being called. Then
 				// transform the call.
@@ -479,7 +1029,7 @@ func (subst *subster) node(n ir.Node) ir.Node {
 				name := call.X.Name()
 				if name.BuiltinOp != ir.OXXX {
 					switch name.BuiltinOp {
-					case ir.OMAKE, ir.OREAL, ir.OIMAG, ir.OLEN, ir.OCAP, ir.OAPPEND:
+					case ir.OMAKE, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.ODELETE:
 						// Transform these builtins now that we
 						// know the type of the args.
 						m = transformBuiltin(call)
@@ -506,41 +1056,127 @@ func (subst *subster) node(n ir.Node) ir.Node {
 			}
 
 		case ir.OCLOSURE:
+			// We're going to create a new closure from scratch, so clear m
+			// to avoid using the ir.Copy by accident until we reassign it.
+			m = nil
+
 			x := x.(*ir.ClosureExpr)
 			// Need to duplicate x.Func.Nname, x.Func.Dcl, x.Func.ClosureVars, and
 			// x.Func.Body.
 			oldfn := x.Func
-			newfn := ir.NewFunc(oldfn.Pos())
-			if oldfn.ClosureCalled() {
-				newfn.SetClosureCalled(true)
-			}
-			newfn.SetIsHiddenClosure(true)
-			m.(*ir.ClosureExpr).Func = newfn
-			// Closure name can already have brackets, if it derives
-			// from a generic method
-			newsym := makeInstName(oldfn.Nname.Sym(), subst.targs, subst.isMethod)
-			newfn.Nname = ir.NewNameAt(oldfn.Nname.Pos(), newsym)
-			newfn.Nname.Func = newfn
-			newfn.Nname.Defn = newfn
-			ir.MarkFunc(newfn.Nname)
-			newfn.OClosure = m.(*ir.ClosureExpr)
+			newfn := ir.NewClosureFunc(oldfn.Pos(), subst.newf != nil)
+			ir.NameClosure(newfn.OClosure, subst.newf)
 
 			saveNewf := subst.newf
 			ir.CurFunc = newfn
 			subst.newf = newfn
 			newfn.Dcl = subst.namelist(oldfn.Dcl)
-			newfn.ClosureVars = subst.namelist(oldfn.ClosureVars)
 
-			typed(subst.typ(oldfn.Nname.Type()), newfn.Nname)
-			typed(newfn.Nname.Type(), m)
+			// Make a closure variable for the dictionary of the
+			// containing function.
+			cdict := ir.CaptureName(oldfn.Pos(), newfn, subst.info.dictParam)
+			typed(types.Types[types.TUINTPTR], cdict)
+			ir.FinishCaptureNames(oldfn.Pos(), saveNewf, newfn)
+			newfn.ClosureVars = append(newfn.ClosureVars, subst.namelist(oldfn.ClosureVars)...)
+
+			// Create inst info for the instantiated closure. The dict
+			// param is the closure variable for the dictionary of the
+			// outer function. Since the dictionary is shared, use the
+			// same entries for startSubDict, dictLen, dictEntryMap.
+			cinfo := &instInfo{
+				fun:           newfn,
+				dictParam:     cdict,
+				gf:            subst.info.gf,
+				gfInfo:        subst.info.gfInfo,
+				startSubDict:  subst.info.startSubDict,
+				startItabConv: subst.info.startItabConv,
+				dictLen:       subst.info.dictLen,
+				dictEntryMap:  subst.info.dictEntryMap,
+			}
+			subst.g.instInfoMap[newfn.Nname.Sym()] = cinfo
+
+			typed(subst.ts.Typ(oldfn.Nname.Type()), newfn.Nname)
+			typed(newfn.Nname.Type(), newfn.OClosure)
 			newfn.SetTypecheck(1)
 
+			outerinfo := subst.info
+			subst.info = cinfo
 			// Make sure type of closure function is set before doing body.
 			newfn.Body = subst.list(oldfn.Body)
+			subst.info = outerinfo
 			subst.newf = saveNewf
 			ir.CurFunc = saveNewf
 
-			subst.g.target.Decls = append(subst.g.target.Decls, newfn)
+			m = ir.UseClosure(newfn.OClosure, subst.g.target)
+			m.(*ir.ClosureExpr).SetInit(subst.list(x.Init()))
+
+		case ir.OCONVIFACE:
+			x := x.(*ir.ConvExpr)
+			// Note: x's argument is still typed as a type parameter.
+			// m's argument now has an instantiated type.
+			if x.X.Type().HasTParam() {
+				m = convertUsingDictionary(subst.info, subst.info.dictParam, m.Pos(), m.(*ir.ConvExpr).X, x, m.Type(), x.X.Type())
+			}
+		case ir.ODOTTYPE, ir.ODOTTYPE2:
+			dt := m.(*ir.TypeAssertExpr)
+			var rt ir.Node
+			if dt.Type().IsInterface() || dt.X.Type().IsEmptyInterface() {
+				ix := findDictType(subst.info, x.Type())
+				assert(ix >= 0)
+				rt = getDictionaryType(subst.info, subst.info.dictParam, dt.Pos(), ix)
+			} else {
+				// nonempty interface to noninterface. Need an itab.
+				ix := -1
+				for i, ic := range subst.info.gfInfo.itabConvs {
+					if ic == x {
+						ix = subst.info.startItabConv + i
+						break
+					}
+				}
+				assert(ix >= 0)
+				rt = getDictionaryEntry(dt.Pos(), subst.info.dictParam, ix, subst.info.dictLen)
+			}
+			op := ir.ODYNAMICDOTTYPE
+			if x.Op() == ir.ODOTTYPE2 {
+				op = ir.ODYNAMICDOTTYPE2
+			}
+			m = ir.NewDynamicTypeAssertExpr(dt.Pos(), op, dt.X, rt)
+			m.SetType(dt.Type())
+			m.SetTypecheck(1)
+		case ir.OCASE:
+			if _, ok := x.(*ir.CommClause); ok {
+				// This is not a type switch. TODO: Should we use an OSWITCH case here instead of OCASE?
+				break
+			}
+			x := x.(*ir.CaseClause)
+			m := m.(*ir.CaseClause)
+			for i, c := range x.List {
+				if c.Op() == ir.OTYPE && c.Type().HasTParam() {
+					// Use a *runtime._type for the dynamic type.
+					ix := findDictType(subst.info, c.Type())
+					assert(ix >= 0)
+					dt := ir.NewDynamicType(c.Pos(), getDictionaryEntry(c.Pos(), subst.info.dictParam, ix, subst.info.dictLen))
+
+					// For type switch from nonempty interfaces to non-interfaces, we need an itab as well.
+					if !m.List[i].Type().IsInterface() {
+						if _, ok := subst.info.gfInfo.type2switchType[c]; ok {
+							// Type switch from nonempty interface. We need a *runtime.itab
+							// for the dynamic type.
+							ix := -1
+							for i, ic := range subst.info.gfInfo.itabConvs {
+								if ic == c {
+									ix = subst.info.startItabConv + i
+									break
+								}
+							}
+							assert(ix >= 0)
+							dt.ITab = getDictionaryEntry(c.Pos(), subst.info.dictParam, ix, subst.info.dictLen)
+						}
+					}
+					typed(m.List[i].Type(), dt)
+					m.List[i] = dt
+				}
+			}
 		}
 		return m
 	}
@@ -548,10 +1184,73 @@ func (subst *subster) node(n ir.Node) ir.Node {
 	return edit(n)
 }
 
+// findDictType looks for type t in the typeparams or derived types in the generic
+// function info.gfInfo. This will indicate the dictionary entry with the
+// correct concrete type for the associated instantiated function.
+func findDictType(info *instInfo, t *types.Type) int {
+	for i, dt := range info.gfInfo.tparams {
+		if dt == t {
+			return i
+		}
+	}
+	for i, dt := range info.gfInfo.derivedTypes {
+		if types.Identical(dt, t) {
+			return i + len(info.gfInfo.tparams)
+		}
+	}
+	return -1
+}
+
+// convertUsingDictionary converts value v from instantiated type src to an interface
+// type dst, by returning a new set of nodes that make use of a dictionary entry. src
+// is the generic (not shape) type, and gn is the original generic node of the
+// CONVIFACE node or XDOT node (for a bound method call) that is causing the
+// conversion.
+func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v ir.Node, gn ir.Node, dst, src *types.Type) ir.Node {
+	assert(src.HasTParam())
+	assert(dst.IsInterface())
+
+	var rt ir.Node
+	if !dst.IsEmptyInterface() {
+		// We should have an itab entry in the dictionary. Using this itab
+		// will be more efficient than converting to an empty interface first
+		// and then type asserting to dst.
+		ix := -1
+		for i, ic := range info.gfInfo.itabConvs {
+			if ic == gn {
+				ix = info.startItabConv + i
+				break
+			}
+		}
+		assert(ix >= 0)
+		rt = getDictionaryEntry(pos, dictParam, ix, info.dictLen)
+	} else {
+		ix := findDictType(info, src)
+		assert(ix >= 0)
+		// Load the actual runtime._type of the type parameter from the dictionary.
+		rt = getDictionaryType(info, dictParam, pos, ix)
+	}
+
+	// Figure out what the data field of the interface will be.
+	var data ir.Node
+	if v.Type().IsInterface() {
+		data = ir.NewUnaryExpr(pos, ir.OIDATA, v)
+	} else {
+		data = ir.NewConvExpr(pos, ir.OCONVIDATA, nil, v)
+	}
+	typed(types.Types[types.TUNSAFEPTR], data)
+
+	// Build an interface from the type and data parts.
+	var i ir.Node = ir.NewBinaryExpr(pos, ir.OEFACE, rt, data)
+	typed(dst, i)
+	return i
+
+}
+
 func (subst *subster) namelist(l []*ir.Name) []*ir.Name {
 	s := make([]*ir.Name, len(l))
 	for i, n := range l {
-		s[i] = subst.node(n).(*ir.Name)
+		s[i] = subst.localvar(n)
 		if n.Defn != nil {
 			s[i].Defn = subst.node(n.Defn)
 		}
@@ -570,302 +1269,6 @@ func (subst *subster) list(l []ir.Node) []ir.Node {
 	return s
 }
 
-// tstruct substitutes type params in types of the fields of a structure type. For
-// each field, if Nname is set, tstruct also translates the Nname using
-// subst.vars, if Nname is in subst.vars. To always force the creation of a new
-// (top-level) struct, regardless of whether anything changed with the types or
-// names of the struct's fields, set force to true.
-func (subst *subster) tstruct(t *types.Type, force bool) *types.Type {
-	if t.NumFields() == 0 {
-		if t.HasTParam() {
-			// For an empty struct, we need to return a new type,
-			// since it may now be fully instantiated (HasTParam
-			// becomes false).
-			return types.NewStruct(t.Pkg(), nil)
-		}
-		return t
-	}
-	var newfields []*types.Field
-	if force {
-		newfields = make([]*types.Field, t.NumFields())
-	}
-	for i, f := range t.Fields().Slice() {
-		t2 := subst.typ(f.Type)
-		if (t2 != f.Type || f.Nname != nil) && newfields == nil {
-			newfields = make([]*types.Field, t.NumFields())
-			for j := 0; j < i; j++ {
-				newfields[j] = t.Field(j)
-			}
-		}
-		if newfields != nil {
-			// TODO(danscales): make sure this works for the field
-			// names of embedded types (which should keep the name of
-			// the type param, not the instantiated type).
-			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
-			if f.Nname != nil {
-				// f.Nname may not be in subst.vars[] if this is
-				// a function name or a function instantiation type
-				// that we are translating
-				v := subst.vars[f.Nname.(*ir.Name)]
-				// Be careful not to put a nil var into Nname,
-				// since Nname is an interface, so it would be a
-				// non-nil interface.
-				if v != nil {
-					newfields[i].Nname = v
-				}
-			}
-		}
-	}
-	if newfields != nil {
-		return types.NewStruct(t.Pkg(), newfields)
-	}
-	return t
-
-}
-
-// tinter substitutes type params in types of the methods of an interface type.
-func (subst *subster) tinter(t *types.Type) *types.Type {
-	if t.Methods().Len() == 0 {
-		return t
-	}
-	var newfields []*types.Field
-	for i, f := range t.Methods().Slice() {
-		t2 := subst.typ(f.Type)
-		if (t2 != f.Type || f.Nname != nil) && newfields == nil {
-			newfields = make([]*types.Field, t.Methods().Len())
-			for j := 0; j < i; j++ {
-				newfields[j] = t.Methods().Index(j)
-			}
-		}
-		if newfields != nil {
-			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
-		}
-	}
-	if newfields != nil {
-		return types.NewInterface(t.Pkg(), newfields)
-	}
-	return t
-}
-
-// instTypeName creates a name for an instantiated type, based on the name of the
-// generic type and the type args
-func instTypeName(name string, targs []*types.Type) string {
-	b := bytes.NewBufferString(name)
-	b.WriteByte('[')
-	for i, targ := range targs {
-		if i > 0 {
-			b.WriteByte(',')
-		}
-		b.WriteString(targ.String())
-	}
-	b.WriteByte(']')
-	return b.String()
-}
-
-// typ computes the type obtained by substituting any type parameter in t with the
-// corresponding type argument in subst. If t contains no type parameters, the
-// result is t; otherwise the result is a new type. It deals with recursive types
-// by using TFORW types and finding partially or fully created types via sym.Def.
-func (subst *subster) typ(t *types.Type) *types.Type {
-	if !t.HasTParam() && t.Kind() != types.TFUNC {
-		// Note: function types need to be copied regardless, as the
-		// types of closures may contain declarations that need
-		// to be copied. See #45738.
-		return t
-	}
-
-	if t.Kind() == types.TTYPEPARAM {
-		for i, tp := range subst.tparams {
-			if tp.Type == t {
-				return subst.targs[i].Type()
-			}
-		}
-		// If t is a simple typeparam T, then t has the name/symbol 'T'
-		// and t.Underlying() == t.
-		//
-		// However, consider the type definition: 'type P[T any] T'. We
-		// might use this definition so we can have a variant of type T
-		// that we can add new methods to. Suppose t is a reference to
-		// P[T]. t has the name 'P[T]', but its kind is TTYPEPARAM,
-		// because P[T] is defined as T. If we look at t.Underlying(), it
-		// is different, because the name of t.Underlying() is 'T' rather
-		// than 'P[T]'. But the kind of t.Underlying() is also TTYPEPARAM.
-		// In this case, we do the needed recursive substitution in the
-		// case statement below.
-		if t.Underlying() == t {
-			// t is a simple typeparam that didn't match anything in tparam
-			return t
-		}
-		// t is a more complex typeparam (e.g. P[T], as above, whose
-		// definition is just T).
-		assert(t.Sym() != nil)
-	}
-
-	var newsym *types.Sym
-	var neededTargs []*types.Type
-	var forw *types.Type
-
-	if t.Sym() != nil {
-		// Translate the type params for this type according to
-		// the tparam/targs mapping from subst.
-		neededTargs = make([]*types.Type, len(t.RParams()))
-		for i, rparam := range t.RParams() {
-			neededTargs[i] = subst.typ(rparam)
-		}
-		// For a named (defined) type, we have to change the name of the
-		// type as well. We do this first, so we can look up if we've
-		// already seen this type during this substitution or other
-		// definitions/substitutions.
-		genName := genericTypeName(t.Sym())
-		newsym = t.Sym().Pkg.Lookup(instTypeName(genName, neededTargs))
-		if newsym.Def != nil {
-			// We've already created this instantiated defined type.
-			return newsym.Def.Type()
-		}
-
-		// In order to deal with recursive generic types, create a TFORW
-		// type initially and set the Def field of its sym, so it can be
-		// found if this type appears recursively within the type.
-		forw = newIncompleteNamedType(t.Pos(), newsym)
-		//println("Creating new type by sub", newsym.Name, forw.HasTParam())
-		forw.SetRParams(neededTargs)
-	}
-
-	var newt *types.Type
-
-	switch t.Kind() {
-	case types.TTYPEPARAM:
-		if t.Sym() == newsym {
-			// The substitution did not change the type.
-			return t
-		}
-		// Substitute the underlying typeparam (e.g. T in P[T], see
-		// the example describing type P[T] above).
-		newt = subst.typ(t.Underlying())
-		assert(newt != t)
-
-	case types.TARRAY:
-		elem := t.Elem()
-		newelem := subst.typ(elem)
-		if newelem != elem {
-			newt = types.NewArray(newelem, t.NumElem())
-		}
-
-	case types.TPTR:
-		elem := t.Elem()
-		newelem := subst.typ(elem)
-		if newelem != elem {
-			newt = types.NewPtr(newelem)
-		}
-
-	case types.TSLICE:
-		elem := t.Elem()
-		newelem := subst.typ(elem)
-		if newelem != elem {
-			newt = types.NewSlice(newelem)
-		}
-
-	case types.TSTRUCT:
-		newt = subst.tstruct(t, false)
-		if newt == t {
-			newt = nil
-		}
-
-	case types.TFUNC:
-		newrecvs := subst.tstruct(t.Recvs(), false)
-		newparams := subst.tstruct(t.Params(), false)
-		newresults := subst.tstruct(t.Results(), false)
-		if newrecvs != t.Recvs() || newparams != t.Params() || newresults != t.Results() {
-			// If any types have changed, then the all the fields of
-			// of recv, params, and results must be copied, because they have
-			// offset fields that are dependent, and so must have an
-			// independent copy for each new signature.
-			var newrecv *types.Field
-			if newrecvs.NumFields() > 0 {
-				if newrecvs == t.Recvs() {
-					newrecvs = subst.tstruct(t.Recvs(), true)
-				}
-				newrecv = newrecvs.Field(0)
-			}
-			if newparams == t.Params() {
-				newparams = subst.tstruct(t.Params(), true)
-			}
-			if newresults == t.Results() {
-				newresults = subst.tstruct(t.Results(), true)
-			}
-			newt = types.NewSignature(t.Pkg(), newrecv, t.TParams().FieldSlice(), newparams.FieldSlice(), newresults.FieldSlice())
-		}
-
-	case types.TINTER:
-		newt = subst.tinter(t)
-		if newt == t {
-			newt = nil
-		}
-
-	case types.TMAP:
-		newkey := subst.typ(t.Key())
-		newval := subst.typ(t.Elem())
-		if newkey != t.Key() || newval != t.Elem() {
-			newt = types.NewMap(newkey, newval)
-		}
-
-	case types.TCHAN:
-		elem := t.Elem()
-		newelem := subst.typ(elem)
-		if newelem != elem {
-			newt = types.NewChan(newelem, t.ChanDir())
-			if !newt.HasTParam() {
-				// TODO(danscales): not sure why I have to do this
-				// only for channels.....
-				types.CheckSize(newt)
-			}
-		}
-	}
-	if newt == nil {
-		// Even though there were typeparams in the type, there may be no
-		// change if this is a function type for a function call (which will
-		// have its own tparams/targs in the function instantiation).
-		return t
-	}
-
-	if t.Sym() == nil {
-		// Not a named type, so there was no forwarding type and there are
-		// no methods to substitute.
-		assert(t.Methods().Len() == 0)
-		return newt
-	}
-
-	forw.SetUnderlying(newt)
-	newt = forw
-
-	if t.Kind() != types.TINTER && t.Methods().Len() > 0 {
-		// Fill in the method info for the new type.
-		var newfields []*types.Field
-		newfields = make([]*types.Field, t.Methods().Len())
-		for i, f := range t.Methods().Slice() {
-			t2 := subst.typ(f.Type)
-			oldsym := f.Nname.Sym()
-			newsym := makeInstName(oldsym, subst.targs, true)
-			var nname *ir.Name
-			if newsym.Def != nil {
-				nname = newsym.Def.(*ir.Name)
-			} else {
-				nname = ir.NewNameAt(f.Pos, newsym)
-				nname.SetType(t2)
-				newsym.Def = nname
-			}
-			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
-			newfields[i].Nname = nname
-		}
-		newt.Methods().Set(newfields)
-		if !newt.HasTParam() {
-			// Generate all the methods for a new fully-instantiated type.
-			subst.g.instTypeList = append(subst.g.instTypeList, newt)
-		}
-	}
-	return newt
-}
-
 // fields sets the Nname field for the Field nodes inside a type signature, based
 // on the corresponding in/out parameters in dcl. It depends on the in and out
 // parameters being in order in dcl.
@@ -885,12 +1288,15 @@ func (subst *subster) fields(class ir.Class, oldfields []*types.Field, dcl []*ir
 	newfields := make([]*types.Field, len(oldfields))
 	for j := range oldfields {
 		newfields[j] = oldfields[j].Copy()
-		newfields[j].Type = subst.typ(oldfields[j].Type)
-		// A param field will be missing from dcl if its name is
+		newfields[j].Type = subst.ts.Typ(oldfields[j].Type)
+		// A PPARAM field will be missing from dcl if its name is
 		// unspecified or specified as "_". So, we compare the dcl sym
-		// with the field sym. If they don't match, this dcl (if there is
-		// one left) must apply to a later field.
-		if i < len(dcl) && dcl[i].Sym() == oldfields[j].Sym {
+		// with the field sym (or sym of the field's Nname node). (Unnamed
+		// results still have a name like ~r2 in their Nname node.) If
+		// they don't match, this dcl (if there is one left) must apply to
+		// a later field.
+		if i < len(dcl) && (dcl[i].Sym() == oldfields[j].Sym ||
+			(oldfields[j].Nname != nil && dcl[i].Sym() == oldfields[j].Nname.Sym())) {
 			newfields[j].Nname = dcl[i]
 			i++
 		}
@@ -898,7 +1304,7 @@ func (subst *subster) fields(class ir.Class, oldfields []*types.Field, dcl []*ir
 	return newfields
 }
 
-// defer does a single defer of type t, if it is a pointer type.
+// deref does a single deref of type t, if it is a pointer type.
 func deref(t *types.Type) *types.Type {
 	if t.IsPtr() {
 		return t.Elem()
@@ -906,12 +1312,658 @@ func deref(t *types.Type) *types.Type {
 	return t
 }
 
-// newIncompleteNamedType returns a TFORW type t with name specified by sym, such
-// that t.nod and sym.Def are set correctly.
-func newIncompleteNamedType(pos src.XPos, sym *types.Sym) *types.Type {
-	name := ir.NewDeclNameAt(pos, ir.OTYPE, sym)
-	forw := types.NewNamed(name)
-	name.SetType(forw)
-	sym.Def = name
-	return forw
+// markTypeUsed marks type t as used in order to help avoid dead-code elimination of
+// needed methods.
+func markTypeUsed(t *types.Type, lsym *obj.LSym) {
+	if t.IsInterface() {
+		// Mark all the methods of the interface as used.
+		// TODO: we should really only mark the interface methods
+		// that are actually called in the application.
+		for i, _ := range t.AllMethods().Slice() {
+			reflectdata.MarkUsedIfaceMethodIndex(lsym, t, i)
+		}
+	} else {
+		// TODO: This is somewhat overkill, we really only need it
+		// for types that are put into interfaces.
+		reflectdata.MarkTypeUsedInInterface(t, lsym)
+	}
+}
+
+// getDictionarySym returns the dictionary for the named generic function gf, which
+// is instantiated with the type arguments targs.
+func (g *irgen) getDictionarySym(gf *ir.Name, targs []*types.Type, isMeth bool) *types.Sym {
+	if len(targs) == 0 {
+		base.Fatalf("%s should have type arguments", gf.Sym().Name)
+	}
+
+	// Enforce that only concrete types can make it to here.
+	for _, t := range targs {
+		if t.HasShape() {
+			panic(fmt.Sprintf("shape %+v in dictionary for %s", t, gf.Sym().Name))
+		}
+	}
+
+	// Get a symbol representing the dictionary.
+	sym := typecheck.MakeDictName(gf.Sym(), targs, isMeth)
+
+	// Initialize the dictionary, if we haven't yet already.
+	lsym := sym.Linksym()
+	if len(lsym.P) > 0 {
+		// We already started creating this dictionary and its lsym.
+		return sym
+	}
+
+	info := g.getGfInfo(gf)
+
+	infoPrint("=== Creating dictionary %v\n", sym.Name)
+	off := 0
+	// Emit an entry for each targ (concrete type or gcshape).
+	for _, t := range targs {
+		infoPrint(" * %v\n", t)
+		s := reflectdata.TypeLinksym(t)
+		off = objw.SymPtr(lsym, off, s, 0)
+		markTypeUsed(t, lsym)
+	}
+	subst := typecheck.Tsubster{
+		Tparams: info.tparams,
+		Targs:   targs,
+	}
+	// Emit an entry for each derived type (after substituting targs)
+	for _, t := range info.derivedTypes {
+		ts := subst.Typ(t)
+		infoPrint(" - %v\n", ts)
+		s := reflectdata.TypeLinksym(ts)
+		off = objw.SymPtr(lsym, off, s, 0)
+		markTypeUsed(ts, lsym)
+	}
+	// Emit an entry for each subdictionary (after substituting targs)
+	for _, n := range info.subDictCalls {
+		var sym *types.Sym
+		switch n.Op() {
+		case ir.OCALL:
+			call := n.(*ir.CallExpr)
+			if call.X.Op() == ir.OXDOT {
+				var nameNode *ir.Name
+				se := call.X.(*ir.SelectorExpr)
+				if types.IsInterfaceMethod(se.Selection.Type) {
+					// This is a method call enabled by a type bound.
+					tmpse := ir.NewSelectorExpr(base.Pos, ir.OXDOT, se.X, se.Sel)
+					tmpse = typecheck.AddImplicitDots(tmpse)
+					tparam := tmpse.X.Type()
+					assert(tparam.IsTypeParam())
+					recvType := targs[tparam.Index()]
+					if recvType.IsInterface() || len(recvType.RParams()) == 0 {
+						// No sub-dictionary entry is
+						// actually needed, since the
+						// type arg is not an
+						// instantiated type that
+						// will have generic methods.
+						break
+					}
+					// This is a method call for an
+					// instantiated type, so we need a
+					// sub-dictionary.
+					targs := recvType.RParams()
+					genRecvType := recvType.OrigSym.Def.Type()
+					nameNode = typecheck.Lookdot1(call.X, se.Sel, genRecvType, genRecvType.Methods(), 1).Nname.(*ir.Name)
+					sym = g.getDictionarySym(nameNode, targs, true)
+				} else {
+					// This is the case of a normal
+					// method call on a generic type.
+					nameNode = call.X.(*ir.SelectorExpr).Selection.Nname.(*ir.Name)
+					subtargs := deref(call.X.(*ir.SelectorExpr).X.Type()).RParams()
+					s2targs := make([]*types.Type, len(subtargs))
+					for i, t := range subtargs {
+						s2targs[i] = subst.Typ(t)
+					}
+					sym = g.getDictionarySym(nameNode, s2targs, true)
+				}
+			} else {
+				inst := call.X.(*ir.InstExpr)
+				var nameNode *ir.Name
+				var meth *ir.SelectorExpr
+				var isMeth bool
+				if meth, isMeth = inst.X.(*ir.SelectorExpr); isMeth {
+					nameNode = meth.Selection.Nname.(*ir.Name)
+				} else {
+					nameNode = inst.X.(*ir.Name)
+				}
+				subtargs := typecheck.TypesOf(inst.Targs)
+				for i, t := range subtargs {
+					subtargs[i] = subst.Typ(t)
+				}
+				sym = g.getDictionarySym(nameNode, subtargs, isMeth)
+			}
+
+		case ir.OFUNCINST:
+			inst := n.(*ir.InstExpr)
+			nameNode := inst.X.(*ir.Name)
+			subtargs := typecheck.TypesOf(inst.Targs)
+			for i, t := range subtargs {
+				subtargs[i] = subst.Typ(t)
+			}
+			sym = g.getDictionarySym(nameNode, subtargs, false)
+
+		case ir.OXDOT:
+			selExpr := n.(*ir.SelectorExpr)
+			subtargs := deref(selExpr.X.Type()).RParams()
+			s2targs := make([]*types.Type, len(subtargs))
+			for i, t := range subtargs {
+				s2targs[i] = subst.Typ(t)
+			}
+			nameNode := selExpr.Selection.Nname.(*ir.Name)
+			sym = g.getDictionarySym(nameNode, s2targs, true)
+
+		default:
+			assert(false)
+		}
+
+		if sym == nil {
+			// Unused sub-dictionary entry, just emit 0.
+			off = objw.Uintptr(lsym, off, 0)
+			infoPrint(" - Unused subdict entry\n")
+		} else {
+			off = objw.SymPtr(lsym, off, sym.Linksym(), 0)
+			infoPrint(" - Subdict %v\n", sym.Name)
+		}
+	}
+
+	delay := &delayInfo{
+		gf:    gf,
+		targs: targs,
+		sym:   sym,
+		off:   off,
+	}
+	g.dictSymsToFinalize = append(g.dictSymsToFinalize, delay)
+	g.instTypeList = append(g.instTypeList, subst.InstTypeList...)
+	return sym
+}
+
+// finalizeSyms finishes up all dictionaries on g.dictSymsToFinalize, by writing out
+// any needed LSyms for itabs. The itab lsyms create wrappers which need various
+// dictionaries and method instantiations to be complete, so, to avoid recursive
+// dependencies, we finalize the itab lsyms only after all dictionaries syms and
+// instantiations have been created.
+func (g *irgen) finalizeSyms() {
+	for _, d := range g.dictSymsToFinalize {
+		infoPrint("=== Finalizing dictionary %s\n", d.sym.Name)
+
+		lsym := d.sym.Linksym()
+		info := g.getGfInfo(d.gf)
+
+		subst := typecheck.Tsubster{
+			Tparams: info.tparams,
+			Targs:   d.targs,
+		}
+
+		// Emit an entry for each itab
+		for _, n := range info.itabConvs {
+			var srctype, dsttype *types.Type
+			switch n.Op() {
+			case ir.OXDOT:
+				se := n.(*ir.SelectorExpr)
+				srctype = subst.Typ(se.X.Type())
+				dsttype = subst.Typ(se.X.Type().Bound())
+				found := false
+				for i, m := range dsttype.AllMethods().Slice() {
+					if se.Sel == m.Sym {
+						// Mark that this method se.Sel is
+						// used for the dsttype interface, so
+						// it won't get deadcoded.
+						reflectdata.MarkUsedIfaceMethodIndex(lsym, dsttype, i)
+						found = true
+						break
+					}
+				}
+				assert(found)
+			case ir.ODOTTYPE, ir.ODOTTYPE2:
+				srctype = subst.Typ(n.(*ir.TypeAssertExpr).Type())
+				dsttype = subst.Typ(n.(*ir.TypeAssertExpr).X.Type())
+			case ir.OCONVIFACE:
+				srctype = subst.Typ(n.(*ir.ConvExpr).X.Type())
+				dsttype = subst.Typ(n.Type())
+			case ir.OTYPE:
+				srctype = subst.Typ(n.Type())
+				dsttype = subst.Typ(info.type2switchType[n])
+			default:
+				base.Fatalf("itab entry with unknown op %s", n.Op())
+			}
+			if srctype.IsInterface() {
+				// No itab is wanted if src type is an interface. We
+				// will use a type assert instead.
+				d.off = objw.Uintptr(lsym, d.off, 0)
+				infoPrint(" + Unused itab entry for %v\n", srctype)
+			} else {
+				itabLsym := reflectdata.ITabLsym(srctype, dsttype)
+				d.off = objw.SymPtr(lsym, d.off, itabLsym, 0)
+				infoPrint(" + Itab for (%v,%v)\n", srctype, dsttype)
+			}
+		}
+
+		objw.Global(lsym, int32(d.off), obj.DUPOK|obj.RODATA)
+		infoPrint("=== Finalized dictionary %s\n", d.sym.Name)
+
+		g.instTypeList = append(g.instTypeList, subst.InstTypeList...)
+	}
+	g.dictSymsToFinalize = nil
+}
+
+func (g *irgen) getDictionaryValue(gf *ir.Name, targs []*types.Type, isMeth bool) ir.Node {
+	sym := g.getDictionarySym(gf, targs, isMeth)
+
+	// Make a node referencing the dictionary symbol.
+	n := typecheck.NewName(sym)
+	n.SetType(types.Types[types.TUINTPTR]) // should probably be [...]uintptr, but doesn't really matter
+	n.SetTypecheck(1)
+	n.Class = ir.PEXTERN
+	sym.Def = n
+
+	// Return the address of the dictionary.
+	np := typecheck.NodAddr(n)
+	// Note: treat dictionary pointers as uintptrs, so they aren't pointers
+	// with respect to GC. That saves on stack scanning work, write barriers, etc.
+	// We can get away with it because dictionaries are global variables.
+	// TODO: use a cast, or is typing directly ok?
+	np.SetType(types.Types[types.TUINTPTR])
+	np.SetTypecheck(1)
+	return np
+}
+
+// hasTParamNodes returns true if the type of any node in targs has a typeparam.
+func hasTParamNodes(targs []ir.Node) bool {
+	for _, n := range targs {
+		if n.Type().HasTParam() {
+			return true
+		}
+	}
+	return false
+}
+
+// hasTParamNodes returns true if any type in targs has a typeparam.
+func hasTParamTypes(targs []*types.Type) bool {
+	for _, t := range targs {
+		if t.HasTParam() {
+			return true
+		}
+	}
+	return false
+}
+
+// getGfInfo get information for a generic function - type params, derived generic
+// types, and subdictionaries.
+func (g *irgen) getGfInfo(gn *ir.Name) *gfInfo {
+	infop := g.gfInfoMap[gn.Sym()]
+	if infop != nil {
+		return infop
+	}
+
+	checkFetchBody(gn)
+	var info gfInfo
+	gf := gn.Func
+	recv := gf.Type().Recv()
+	if recv != nil {
+		info.tparams = deref(recv.Type).RParams()
+	} else {
+		tparams := gn.Type().TParams().FieldSlice()
+		info.tparams = make([]*types.Type, len(tparams))
+		for i, f := range tparams {
+			info.tparams[i] = f.Type
+		}
+	}
+
+	for _, t := range info.tparams {
+		b := t.Bound()
+		if b.HasTParam() {
+			// If a type bound is parameterized (unusual case), then we
+			// may need its derived type to do a type assert when doing a
+			// bound call for a type arg that is an interface.
+			addType(&info, nil, b)
+		}
+	}
+
+	for _, n := range gf.Dcl {
+		addType(&info, n, n.Type())
+	}
+
+	if infoPrintMode {
+		fmt.Printf(">>> GfInfo for %v\n", gn)
+		for _, t := range info.tparams {
+			fmt.Printf("  Typeparam %v\n", t)
+		}
+	}
+
+	var visitFunc func(ir.Node)
+	visitFunc = func(n ir.Node) {
+		if n.Op() == ir.OFUNCINST && !n.(*ir.InstExpr).Implicit() {
+			if hasTParamNodes(n.(*ir.InstExpr).Targs) {
+				infoPrint("  Closure&subdictionary required at generic function value %v\n", n.(*ir.InstExpr).X)
+				info.subDictCalls = append(info.subDictCalls, n)
+			}
+		} else if n.Op() == ir.OXDOT && !n.(*ir.SelectorExpr).Implicit() &&
+			n.(*ir.SelectorExpr).Selection != nil &&
+			len(deref(n.(*ir.SelectorExpr).X.Type()).RParams()) > 0 {
+			if hasTParamTypes(deref(n.(*ir.SelectorExpr).X.Type()).RParams()) {
+				if n.(*ir.SelectorExpr).X.Op() == ir.OTYPE {
+					infoPrint("  Closure&subdictionary required at generic meth expr %v\n", n)
+				} else {
+					infoPrint("  Closure&subdictionary required at generic meth value %v\n", n)
+				}
+				info.subDictCalls = append(info.subDictCalls, n)
+			}
+		}
+		if n.Op() == ir.OCALL && n.(*ir.CallExpr).X.Op() == ir.OFUNCINST {
+			n.(*ir.CallExpr).X.(*ir.InstExpr).SetImplicit(true)
+			if hasTParamNodes(n.(*ir.CallExpr).X.(*ir.InstExpr).Targs) {
+				infoPrint("  Subdictionary at generic function/method call: %v - %v\n", n.(*ir.CallExpr).X.(*ir.InstExpr).X, n)
+				info.subDictCalls = append(info.subDictCalls, n)
+			}
+		}
+		if n.Op() == ir.OCALL && n.(*ir.CallExpr).X.Op() == ir.OXDOT &&
+			n.(*ir.CallExpr).X.(*ir.SelectorExpr).Selection != nil &&
+			len(deref(n.(*ir.CallExpr).X.(*ir.SelectorExpr).X.Type()).RParams()) > 0 {
+			n.(*ir.CallExpr).X.(*ir.SelectorExpr).SetImplicit(true)
+			if hasTParamTypes(deref(n.(*ir.CallExpr).X.(*ir.SelectorExpr).X.Type()).RParams()) {
+				infoPrint("  Subdictionary at generic method call: %v\n", n)
+				info.subDictCalls = append(info.subDictCalls, n)
+			}
+		}
+		if n.Op() == ir.OCALL && n.(*ir.CallExpr).X.Op() == ir.OXDOT &&
+			n.(*ir.CallExpr).X.(*ir.SelectorExpr).Selection != nil &&
+			deref(n.(*ir.CallExpr).X.(*ir.SelectorExpr).X.Type()).IsTypeParam() {
+			n.(*ir.CallExpr).X.(*ir.SelectorExpr).SetImplicit(true)
+			infoPrint("  Optional subdictionary at generic bound call: %v\n", n)
+			info.subDictCalls = append(info.subDictCalls, n)
+		}
+		if n.Op() == ir.OCONVIFACE && n.Type().IsInterface() &&
+			!n.Type().IsEmptyInterface() &&
+			n.(*ir.ConvExpr).X.Type().HasTParam() {
+			infoPrint("  Itab for interface conv: %v\n", n)
+			info.itabConvs = append(info.itabConvs, n)
+		}
+		if n.Op() == ir.OXDOT && n.(*ir.SelectorExpr).X.Type().IsTypeParam() {
+			infoPrint("  Itab for bound call: %v\n", n)
+			info.itabConvs = append(info.itabConvs, n)
+		}
+		if (n.Op() == ir.ODOTTYPE || n.Op() == ir.ODOTTYPE2) && !n.(*ir.TypeAssertExpr).Type().IsInterface() && !n.(*ir.TypeAssertExpr).X.Type().IsEmptyInterface() {
+			infoPrint("  Itab for dot type: %v\n", n)
+			info.itabConvs = append(info.itabConvs, n)
+		}
+		if n.Op() == ir.OCLOSURE {
+			// Visit the closure body and add all relevant entries to the
+			// dictionary of the outer function (closure will just use
+			// the dictionary of the outer function).
+			for _, n1 := range n.(*ir.ClosureExpr).Func.Body {
+				ir.Visit(n1, visitFunc)
+			}
+		}
+		if n.Op() == ir.OSWITCH && n.(*ir.SwitchStmt).Tag != nil && n.(*ir.SwitchStmt).Tag.Op() == ir.OTYPESW && !n.(*ir.SwitchStmt).Tag.(*ir.TypeSwitchGuard).X.Type().IsEmptyInterface() {
+			for _, cc := range n.(*ir.SwitchStmt).Cases {
+				for _, c := range cc.List {
+					if c.Op() == ir.OTYPE && c.Type().HasTParam() {
+						// Type switch from a non-empty interface - might need an itab.
+						infoPrint("  Itab for type switch: %v\n", c)
+						info.itabConvs = append(info.itabConvs, c)
+						if info.type2switchType == nil {
+							info.type2switchType = map[ir.Node]*types.Type{}
+						}
+						info.type2switchType[c] = n.(*ir.SwitchStmt).Tag.(*ir.TypeSwitchGuard).X.Type()
+					}
+				}
+			}
+		}
+		addType(&info, n, n.Type())
+	}
+
+	for _, stmt := range gf.Body {
+		ir.Visit(stmt, visitFunc)
+	}
+	if infoPrintMode {
+		for _, t := range info.derivedTypes {
+			fmt.Printf("  Derived type %v\n", t)
+		}
+		fmt.Printf(">>> Done Gfinfo\n")
+	}
+	g.gfInfoMap[gn.Sym()] = &info
+	return &info
+}
+
+// addType adds t to info.derivedTypes if it is parameterized type (which is not
+// just a simple type param) that is different from any existing type on
+// info.derivedTypes.
+func addType(info *gfInfo, n ir.Node, t *types.Type) {
+	if t == nil || !t.HasTParam() {
+		return
+	}
+	if t.IsTypeParam() && t.Underlying() == t {
+		return
+	}
+	if t.Kind() == types.TFUNC && n != nil &&
+		(t.Recv() != nil ||
+			n.Op() == ir.ONAME && n.Name().Class == ir.PFUNC) {
+		// Don't use the type of a named generic function or method,
+		// since that is parameterized by other typeparams.
+		// (They all come from arguments of a FUNCINST node.)
+		return
+	}
+	if doubleCheck && !parameterizedBy(t, info.tparams) {
+		base.Fatalf("adding type with invalid parameters %+v", t)
+	}
+	if t.Kind() == types.TSTRUCT && t.IsFuncArgStruct() {
+		// Multiple return values are not a relevant new type (?).
+		return
+	}
+	// Ignore a derived type we've already added.
+	for _, et := range info.derivedTypes {
+		if types.Identical(t, et) {
+			return
+		}
+	}
+	info.derivedTypes = append(info.derivedTypes, t)
+}
+
+// parameterizedBy returns true if t is parameterized by (at most) params.
+func parameterizedBy(t *types.Type, params []*types.Type) bool {
+	return parameterizedBy1(t, params, map[*types.Type]bool{})
+}
+func parameterizedBy1(t *types.Type, params []*types.Type, visited map[*types.Type]bool) bool {
+	if visited[t] {
+		return true
+	}
+	visited[t] = true
+
+	if t.Sym() != nil && len(t.RParams()) > 0 {
+		// This defined type is instantiated. Check the instantiating types.
+		for _, r := range t.RParams() {
+			if !parameterizedBy1(r, params, visited) {
+				return false
+			}
+		}
+		return true
+	}
+	switch t.Kind() {
+	case types.TTYPEPARAM:
+		// Check if t is one of the allowed parameters in scope.
+		for _, p := range params {
+			if p == t {
+				return true
+			}
+		}
+		// Couldn't find t in the list of allowed parameters.
+		return false
+
+	case types.TARRAY, types.TPTR, types.TSLICE, types.TCHAN:
+		return parameterizedBy1(t.Elem(), params, visited)
+
+	case types.TMAP:
+		return parameterizedBy1(t.Key(), params, visited) && parameterizedBy1(t.Elem(), params, visited)
+
+	case types.TFUNC:
+		return parameterizedBy1(t.TParams(), params, visited) && parameterizedBy1(t.Recvs(), params, visited) && parameterizedBy1(t.Params(), params, visited) && parameterizedBy1(t.Results(), params, visited)
+
+	case types.TSTRUCT:
+		for _, f := range t.Fields().Slice() {
+			if !parameterizedBy1(f.Type, params, visited) {
+				return false
+			}
+		}
+		return true
+
+	case types.TINTER:
+		for _, f := range t.Methods().Slice() {
+			if !parameterizedBy1(f.Type, params, visited) {
+				return false
+			}
+		}
+		return true
+
+	case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64,
+		types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64,
+		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128:
+		return true
+
+	case types.TUNION:
+		for i := 0; i < t.NumTerms(); i++ {
+			tt, _ := t.Term(i)
+			if !parameterizedBy1(tt, params, visited) {
+				return false
+			}
+		}
+		return true
+
+	default:
+		base.Fatalf("bad type kind %+v", t)
+		return true
+	}
+}
+
+// startClosures starts creation of a closure that has the function type typ. It
+// creates all the formal params and results according to the type typ. On return,
+// the body and closure variables of the closure must still be filled in, and
+// ir.UseClosure() called.
+func startClosure(pos src.XPos, outer *ir.Func, typ *types.Type) (*ir.Func, []*types.Field, []*types.Field) {
+	// Make a new internal function.
+	fn := ir.NewClosureFunc(pos, outer != nil)
+	ir.NameClosure(fn.OClosure, outer)
+
+	// Build formal argument and return lists.
+	var formalParams []*types.Field  // arguments of closure
+	var formalResults []*types.Field // returns of closure
+	for i := 0; i < typ.NumParams(); i++ {
+		t := typ.Params().Field(i).Type
+		arg := ir.NewNameAt(pos, typecheck.LookupNum("a", i))
+		arg.Class = ir.PPARAM
+		typed(t, arg)
+		arg.Curfn = fn
+		fn.Dcl = append(fn.Dcl, arg)
+		f := types.NewField(pos, arg.Sym(), t)
+		f.Nname = arg
+		formalParams = append(formalParams, f)
+	}
+	for i := 0; i < typ.NumResults(); i++ {
+		t := typ.Results().Field(i).Type
+		result := ir.NewNameAt(pos, typecheck.LookupNum("r", i)) // TODO: names not needed?
+		result.Class = ir.PPARAMOUT
+		typed(t, result)
+		result.Curfn = fn
+		fn.Dcl = append(fn.Dcl, result)
+		f := types.NewField(pos, result.Sym(), t)
+		f.Nname = result
+		formalResults = append(formalResults, f)
+	}
+
+	// Build an internal function with the right signature.
+	closureType := types.NewSignature(typ.Pkg(), nil, nil, formalParams, formalResults)
+	typed(closureType, fn.Nname)
+	typed(typ, fn.OClosure)
+	fn.SetTypecheck(1)
+	return fn, formalParams, formalResults
+
+}
+
+// assertToBound returns a new node that converts a node rcvr with interface type to
+// the 'dst' interface type.  bound is the unsubstituted form of dst.
+func assertToBound(info *instInfo, dictVar *ir.Name, pos src.XPos, rcvr ir.Node, bound, dst *types.Type) ir.Node {
+	if bound.HasTParam() {
+		ix := findDictType(info, bound)
+		assert(ix >= 0)
+		rt := getDictionaryType(info, dictVar, pos, ix)
+		rcvr = ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, rcvr, rt)
+		typed(dst, rcvr)
+	} else {
+		rcvr = ir.NewTypeAssertExpr(pos, rcvr, nil)
+		typed(bound, rcvr)
+	}
+	return rcvr
+}
+
+// buildClosure2 makes a closure to implement a method expression m (generic form x)
+// which has a shape type as receiver. If the receiver is exactly a shape (i.e. from
+// a typeparam), then the body of the closure converts m.X (the receiver) to the
+// interface bound type, and makes an interface call with the remaining arguments.
+//
+// The returned closure is fully substituted and has already had any needed
+// transformations done.
+func (g *irgen) buildClosure2(subst *subster, m, x ir.Node) ir.Node {
+	outer := subst.newf
+	info := subst.info
+	pos := m.Pos()
+	typ := m.Type() // type of the closure
+
+	fn, formalParams, formalResults := startClosure(pos, outer, typ)
+
+	// Capture dictionary calculated in the outer function
+	dictVar := ir.CaptureName(pos, fn, info.dictParam)
+	typed(types.Types[types.TUINTPTR], dictVar)
+
+	// Build arguments to call inside the closure.
+	var args []ir.Node
+	for i := 0; i < typ.NumParams(); i++ {
+		args = append(args, formalParams[i].Nname.(*ir.Name))
+	}
+
+	// Build call itself. This involves converting the first argument to the
+	// bound type (an interface) using the dictionary, and then making an
+	// interface call with the remaining arguments.
+	var innerCall ir.Node
+	rcvr := args[0]
+	args = args[1:]
+	assert(m.(*ir.SelectorExpr).X.Type().IsShape())
+	gsrc := x.(*ir.SelectorExpr).X.Type()
+	bound := gsrc.Bound()
+	dst := bound
+	if dst.HasTParam() {
+		dst = subst.ts.Typ(bound)
+	}
+	if m.(*ir.SelectorExpr).X.Type().IsInterface() {
+		// If type arg is an interface (unusual case), we do a type assert to
+		// the type bound.
+		rcvr = assertToBound(info, dictVar, pos, rcvr, bound, dst)
+	} else {
+		rcvr = convertUsingDictionary(info, dictVar, pos, rcvr, x, dst, gsrc)
+	}
+	dot := ir.NewSelectorExpr(pos, ir.ODOTINTER, rcvr, x.(*ir.SelectorExpr).Sel)
+	dot.Selection = typecheck.Lookdot1(dot, dot.Sel, dot.X.Type(), dot.X.Type().AllMethods(), 1)
+
+	// Do a type substitution on the generic bound, in case it is parameterized.
+	typed(subst.ts.Typ(x.(*ir.SelectorExpr).Selection.Type), dot)
+	innerCall = ir.NewCallExpr(pos, ir.OCALLINTER, dot, args)
+	t := m.Type()
+	if t.NumResults() == 0 {
+		innerCall.SetTypecheck(1)
+	} else if t.NumResults() == 1 {
+		typed(t.Results().Field(0).Type, innerCall)
+	} else {
+		typed(t.Results(), innerCall)
+	}
+	if len(formalResults) > 0 {
+		innerCall = ir.NewReturnStmt(pos, []ir.Node{innerCall})
+		innerCall.SetTypecheck(1)
+	}
+	fn.Body = []ir.Node{innerCall}
+
+	// We're all done with the captured dictionary
+	ir.FinishCaptureNames(pos, outer, fn)
+
+	// Do final checks on closure and return it.
+	return ir.UseClosure(fn.OClosure, g.target)
 }
diff --git a/src/cmd/compile/internal/noder/stmt.go b/src/cmd/compile/internal/noder/stmt.go
index 32a1483b4aa..1949f56095f 100644
--- a/src/cmd/compile/internal/noder/stmt.go
+++ b/src/cmd/compile/internal/noder/stmt.go
@@ -35,11 +35,7 @@ func (g *irgen) stmt(stmt syntax.Stmt) ir.Node {
 	case *syntax.BlockStmt:
 		return ir.NewBlockStmt(g.pos(stmt), g.blockStmt(stmt))
 	case *syntax.ExprStmt:
-		x := g.expr(stmt.X)
-		if call, ok := x.(*ir.CallExpr); ok {
-			call.Use = ir.CallUseStmt
-		}
-		return x
+		return g.expr(stmt.X)
 	case *syntax.SendStmt:
 		n := ir.NewSendStmt(g.pos(stmt), g.expr(stmt.Chan), g.expr(stmt.Value))
 		if n.Chan.Type().HasTParam() || n.Value.Type().HasTParam() {
@@ -61,7 +57,10 @@ func (g *irgen) stmt(stmt syntax.Stmt) ir.Node {
 			if stmt.Rhs == nil {
 				n = IncDec(g.pos(stmt), op, g.expr(stmt.Lhs))
 			} else {
-				n = ir.NewAssignOpStmt(g.pos(stmt), op, g.expr(stmt.Lhs), g.expr(stmt.Rhs))
+				// Eval rhs before lhs, for compatibility with noder1
+				rhs := g.expr(stmt.Rhs)
+				lhs := g.expr(stmt.Lhs)
+				n = ir.NewAssignOpStmt(g.pos(stmt), op, lhs, rhs)
 			}
 			if n.X.Typecheck() == 3 {
 				n.SetTypecheck(3)
@@ -72,8 +71,9 @@ func (g *irgen) stmt(stmt syntax.Stmt) ir.Node {
 			return n
 		}
 
-		names, lhs := g.assignList(stmt.Lhs, stmt.Op == syntax.Def)
+		// Eval rhs before lhs, for compatibility with noder1
 		rhs := g.exprList(stmt.Rhs)
+		names, lhs := g.assignList(stmt.Lhs, stmt.Op == syntax.Def)
 
 		// We must delay transforming the assign statement if any of the
 		// lhs or rhs nodes are also delayed, since transformAssign needs
@@ -128,6 +128,12 @@ func (g *irgen) stmt(stmt syntax.Stmt) ir.Node {
 			if e.Type().HasTParam() {
 				// Delay transforming the return statement if any of the
 				// return values have a type param.
+				if !ir.HasNamedResults(ir.CurFunc) {
+					transformArgs(n)
+					// But add CONVIFACE nodes where needed if
+					// any of the return values have interface type.
+					typecheckaste(ir.ORETURN, nil, false, ir.CurFunc.Type().Results(), n.Results, true)
+				}
 				n.SetTypecheck(3)
 				return n
 			}
@@ -266,6 +272,12 @@ func (g *irgen) forStmt(stmt *syntax.ForStmt) ir.Node {
 		key, value := unpackTwo(lhs)
 		n := ir.NewRangeStmt(g.pos(r), key, value, g.expr(r.X), g.blockStmt(stmt.Body))
 		n.Def = initDefn(n, names)
+		if key != nil {
+			transformCheckAssign(n, key)
+		}
+		if value != nil {
+			transformCheckAssign(n, value)
+		}
 		return n
 	}
 
diff --git a/src/cmd/compile/internal/noder/sync.go b/src/cmd/compile/internal/noder/sync.go
new file mode 100644
index 00000000000..7af558f8b20
--- /dev/null
+++ b/src/cmd/compile/internal/noder/sync.go
@@ -0,0 +1,187 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"fmt"
+	"strings"
+)
+
+// enableSync controls whether sync markers are written into unified
+// IR's export data format and also whether they're expected when
+// reading them back in. They're inessential to the correct
+// functioning of unified IR, but are helpful during development to
+// detect mistakes.
+//
+// When sync is enabled, writer stack frames will also be included in
+// the export data. Currently, a fixed number of frames are included,
+// controlled by -d=syncframes (default 0).
+const enableSync = true
+
+// fmtFrames formats a backtrace for reporting reader/writer desyncs.
+func fmtFrames(pcs ...uintptr) []string {
+	res := make([]string, 0, len(pcs))
+	walkFrames(pcs, func(file string, line int, name string, offset uintptr) {
+		// Trim package from function name. It's just redundant noise.
+		name = strings.TrimPrefix(name, "cmd/compile/internal/noder.")
+
+		res = append(res, fmt.Sprintf("%s:%v: %s +0x%v", file, line, name, offset))
+	})
+	return res
+}
+
+type frameVisitor func(file string, line int, name string, offset uintptr)
+
+// syncMarker is an enum type that represents markers that may be
+// written to export data to ensure the reader and writer stay
+// synchronized.
+type syncMarker int
+
+//go:generate stringer -type=syncMarker -trimprefix=sync
+
+// TODO(mdempsky): Cleanup unneeded sync markers.
+
+// TODO(mdempsky): Split these markers into public/stable markers, and
+// private ones. Also, trim unused ones.
+const (
+	_ syncMarker = iota
+	syncNode
+	syncBool
+	syncInt64
+	syncUint64
+	syncString
+	syncPos
+	syncPkg
+	syncSym
+	syncSelector
+	syncKind
+	syncType
+	syncTypePkg
+	syncSignature
+	syncParam
+	syncOp
+	syncObject
+	syncExpr
+	syncStmt
+	syncDecl
+	syncConstDecl
+	syncFuncDecl
+	syncTypeDecl
+	syncVarDecl
+	syncPragma
+	syncValue
+	syncEOF
+	syncMethod
+	syncFuncBody
+	syncUse
+	syncUseObj
+	syncObjectIdx
+	syncTypeIdx
+	syncBOF
+	syncEntry
+	syncOpenScope
+	syncCloseScope
+	syncGlobal
+	syncLocal
+	syncDefine
+	syncDefLocal
+	syncUseLocal
+	syncDefGlobal
+	syncUseGlobal
+	syncTypeParams
+	syncUseLabel
+	syncDefLabel
+	syncFuncLit
+	syncCommonFunc
+	syncBodyRef
+	syncLinksymExt
+	syncHack
+	syncSetlineno
+	syncName
+	syncImportDecl
+	syncDeclNames
+	syncDeclName
+	syncExprList
+	syncExprs
+	syncWrapname
+	syncTypeExpr
+	syncTypeExprOrNil
+	syncChanDir
+	syncParams
+	syncCloseAnotherScope
+	syncSum
+	syncUnOp
+	syncBinOp
+	syncStructType
+	syncInterfaceType
+	syncPackname
+	syncEmbedded
+	syncStmts
+	syncStmtsFall
+	syncStmtFall
+	syncBlockStmt
+	syncIfStmt
+	syncForStmt
+	syncSwitchStmt
+	syncRangeStmt
+	syncCaseClause
+	syncCommClause
+	syncSelectStmt
+	syncDecls
+	syncLabeledStmt
+	syncCompLit
+
+	sync1
+	sync2
+	sync3
+	sync4
+
+	syncN
+	syncDefImplicit
+	syncUseName
+	syncUseObjLocal
+	syncAddLocal
+	syncBothSignature
+	syncSetUnderlying
+	syncLinkname
+	syncStmt1
+	syncStmtsEnd
+	syncDeclare
+	syncTopDecls
+	syncTopConstDecl
+	syncTopFuncDecl
+	syncTopTypeDecl
+	syncTopVarDecl
+	syncObject1
+	syncAddBody
+	syncLabel
+	syncFuncExt
+	syncMethExt
+	syncOptLabel
+	syncScalar
+	syncStmtDecls
+	syncDeclLocal
+	syncObjLocal
+	syncObjLocal1
+	syncDeclareLocal
+	syncPublic
+	syncPrivate
+	syncRelocs
+	syncReloc
+	syncUseReloc
+	syncVarExt
+	syncPkgDef
+	syncTypeExt
+	syncVal
+	syncCodeObj
+	syncPosBase
+	syncLocalIdent
+	syncTypeParamNames
+	syncTypeParamBounds
+	syncImplicitTypes
+	syncObjectName
+)
diff --git a/src/cmd/compile/internal/noder/syncmarker_string.go b/src/cmd/compile/internal/noder/syncmarker_string.go
new file mode 100644
index 00000000000..14747b7c106
--- /dev/null
+++ b/src/cmd/compile/internal/noder/syncmarker_string.go
@@ -0,0 +1,155 @@
+// Code generated by "stringer -type=syncMarker -trimprefix=sync"; DO NOT EDIT.
+
+package noder
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[syncNode-1]
+	_ = x[syncBool-2]
+	_ = x[syncInt64-3]
+	_ = x[syncUint64-4]
+	_ = x[syncString-5]
+	_ = x[syncPos-6]
+	_ = x[syncPkg-7]
+	_ = x[syncSym-8]
+	_ = x[syncSelector-9]
+	_ = x[syncKind-10]
+	_ = x[syncType-11]
+	_ = x[syncTypePkg-12]
+	_ = x[syncSignature-13]
+	_ = x[syncParam-14]
+	_ = x[syncOp-15]
+	_ = x[syncObject-16]
+	_ = x[syncExpr-17]
+	_ = x[syncStmt-18]
+	_ = x[syncDecl-19]
+	_ = x[syncConstDecl-20]
+	_ = x[syncFuncDecl-21]
+	_ = x[syncTypeDecl-22]
+	_ = x[syncVarDecl-23]
+	_ = x[syncPragma-24]
+	_ = x[syncValue-25]
+	_ = x[syncEOF-26]
+	_ = x[syncMethod-27]
+	_ = x[syncFuncBody-28]
+	_ = x[syncUse-29]
+	_ = x[syncUseObj-30]
+	_ = x[syncObjectIdx-31]
+	_ = x[syncTypeIdx-32]
+	_ = x[syncBOF-33]
+	_ = x[syncEntry-34]
+	_ = x[syncOpenScope-35]
+	_ = x[syncCloseScope-36]
+	_ = x[syncGlobal-37]
+	_ = x[syncLocal-38]
+	_ = x[syncDefine-39]
+	_ = x[syncDefLocal-40]
+	_ = x[syncUseLocal-41]
+	_ = x[syncDefGlobal-42]
+	_ = x[syncUseGlobal-43]
+	_ = x[syncTypeParams-44]
+	_ = x[syncUseLabel-45]
+	_ = x[syncDefLabel-46]
+	_ = x[syncFuncLit-47]
+	_ = x[syncCommonFunc-48]
+	_ = x[syncBodyRef-49]
+	_ = x[syncLinksymExt-50]
+	_ = x[syncHack-51]
+	_ = x[syncSetlineno-52]
+	_ = x[syncName-53]
+	_ = x[syncImportDecl-54]
+	_ = x[syncDeclNames-55]
+	_ = x[syncDeclName-56]
+	_ = x[syncExprList-57]
+	_ = x[syncExprs-58]
+	_ = x[syncWrapname-59]
+	_ = x[syncTypeExpr-60]
+	_ = x[syncTypeExprOrNil-61]
+	_ = x[syncChanDir-62]
+	_ = x[syncParams-63]
+	_ = x[syncCloseAnotherScope-64]
+	_ = x[syncSum-65]
+	_ = x[syncUnOp-66]
+	_ = x[syncBinOp-67]
+	_ = x[syncStructType-68]
+	_ = x[syncInterfaceType-69]
+	_ = x[syncPackname-70]
+	_ = x[syncEmbedded-71]
+	_ = x[syncStmts-72]
+	_ = x[syncStmtsFall-73]
+	_ = x[syncStmtFall-74]
+	_ = x[syncBlockStmt-75]
+	_ = x[syncIfStmt-76]
+	_ = x[syncForStmt-77]
+	_ = x[syncSwitchStmt-78]
+	_ = x[syncRangeStmt-79]
+	_ = x[syncCaseClause-80]
+	_ = x[syncCommClause-81]
+	_ = x[syncSelectStmt-82]
+	_ = x[syncDecls-83]
+	_ = x[syncLabeledStmt-84]
+	_ = x[syncCompLit-85]
+	_ = x[sync1-86]
+	_ = x[sync2-87]
+	_ = x[sync3-88]
+	_ = x[sync4-89]
+	_ = x[syncN-90]
+	_ = x[syncDefImplicit-91]
+	_ = x[syncUseName-92]
+	_ = x[syncUseObjLocal-93]
+	_ = x[syncAddLocal-94]
+	_ = x[syncBothSignature-95]
+	_ = x[syncSetUnderlying-96]
+	_ = x[syncLinkname-97]
+	_ = x[syncStmt1-98]
+	_ = x[syncStmtsEnd-99]
+	_ = x[syncDeclare-100]
+	_ = x[syncTopDecls-101]
+	_ = x[syncTopConstDecl-102]
+	_ = x[syncTopFuncDecl-103]
+	_ = x[syncTopTypeDecl-104]
+	_ = x[syncTopVarDecl-105]
+	_ = x[syncObject1-106]
+	_ = x[syncAddBody-107]
+	_ = x[syncLabel-108]
+	_ = x[syncFuncExt-109]
+	_ = x[syncMethExt-110]
+	_ = x[syncOptLabel-111]
+	_ = x[syncScalar-112]
+	_ = x[syncStmtDecls-113]
+	_ = x[syncDeclLocal-114]
+	_ = x[syncObjLocal-115]
+	_ = x[syncObjLocal1-116]
+	_ = x[syncDeclareLocal-117]
+	_ = x[syncPublic-118]
+	_ = x[syncPrivate-119]
+	_ = x[syncRelocs-120]
+	_ = x[syncReloc-121]
+	_ = x[syncUseReloc-122]
+	_ = x[syncVarExt-123]
+	_ = x[syncPkgDef-124]
+	_ = x[syncTypeExt-125]
+	_ = x[syncVal-126]
+	_ = x[syncCodeObj-127]
+	_ = x[syncPosBase-128]
+	_ = x[syncLocalIdent-129]
+	_ = x[syncTypeParamNames-130]
+	_ = x[syncTypeParamBounds-131]
+	_ = x[syncImplicitTypes-132]
+}
+
+const _syncMarker_name = "NodeBoolInt64Uint64StringPosPkgSymSelectorKindTypeTypePkgSignatureParamOpObjectExprStmtDeclConstDeclFuncDeclTypeDeclVarDeclPragmaValueEOFMethodFuncBodyUseUseObjObjectIdxTypeIdxBOFEntryOpenScopeCloseScopeGlobalLocalDefineDefLocalUseLocalDefGlobalUseGlobalTypeParamsUseLabelDefLabelFuncLitCommonFuncBodyRefLinksymExtHackSetlinenoNameImportDeclDeclNamesDeclNameExprListExprsWrapnameTypeExprTypeExprOrNilChanDirParamsCloseAnotherScopeSumUnOpBinOpStructTypeInterfaceTypePacknameEmbeddedStmtsStmtsFallStmtFallBlockStmtIfStmtForStmtSwitchStmtRangeStmtCaseClauseCommClauseSelectStmtDeclsLabeledStmtCompLit1234NDefImplicitUseNameUseObjLocalAddLocalBothSignatureSetUnderlyingLinknameStmt1StmtsEndDeclareTopDeclsTopConstDeclTopFuncDeclTopTypeDeclTopVarDeclObject1AddBodyLabelFuncExtMethExtOptLabelScalarStmtDeclsDeclLocalObjLocalObjLocal1DeclareLocalPublicPrivateRelocsRelocUseRelocVarExtPkgDefTypeExtValCodeObjPosBaseLocalIdentTypeParamNamesTypeParamBoundsImplicitTypes"
+
+var _syncMarker_index = [...]uint16{0, 4, 8, 13, 19, 25, 28, 31, 34, 42, 46, 50, 57, 66, 71, 73, 79, 83, 87, 91, 100, 108, 116, 123, 129, 134, 137, 143, 151, 154, 160, 169, 176, 179, 184, 193, 203, 209, 214, 220, 228, 236, 245, 254, 264, 272, 280, 287, 297, 304, 314, 318, 327, 331, 341, 350, 358, 366, 371, 379, 387, 400, 407, 413, 430, 433, 437, 442, 452, 465, 473, 481, 486, 495, 503, 512, 518, 525, 535, 544, 554, 564, 574, 579, 590, 597, 598, 599, 600, 601, 602, 613, 620, 631, 639, 652, 665, 673, 678, 686, 693, 701, 713, 724, 735, 745, 752, 759, 764, 771, 778, 786, 792, 801, 810, 818, 827, 839, 845, 852, 858, 863, 871, 877, 883, 890, 893, 900, 907, 917, 931, 946, 959}
+
+func (i syncMarker) String() string {
+	i -= 1
+	if i < 0 || i >= syncMarker(len(_syncMarker_index)-1) {
+		return "syncMarker(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	}
+	return _syncMarker_name[_syncMarker_index[i]:_syncMarker_index[i+1]]
+}
diff --git a/src/cmd/compile/internal/noder/transform.go b/src/cmd/compile/internal/noder/transform.go
index 2859089e69b..e1eeb8e7394 100644
--- a/src/cmd/compile/internal/noder/transform.go
+++ b/src/cmd/compile/internal/noder/transform.go
@@ -85,7 +85,15 @@ func stringtoruneslit(n *ir.ConvExpr) ir.Node {
 // etc.  Corresponds to typecheck.tcConv.
 func transformConv(n *ir.ConvExpr) ir.Node {
 	t := n.X.Type()
-	op, _ := typecheck.Convertop(n.X.Op() == ir.OLITERAL, t, n.Type())
+	op, why := typecheck.Convertop(n.X.Op() == ir.OLITERAL, t, n.Type())
+	if op == ir.OXXX {
+		// types2 currently ignores pragmas, so a 'notinheap' mismatch is the
+		// one type-related error that it does not catch. This error will be
+		// caught here by Convertop (see two checks near beginning of
+		// Convertop) and reported at the end of noding.
+		base.ErrorfAt(n.Pos(), "cannot convert %L to type %v%s", n.X, n.Type(), why)
+		return n
+	}
 	n.SetOp(op)
 	switch n.Op() {
 	case ir.OCONVNOP:
@@ -122,7 +130,8 @@ func transformConvCall(n *ir.CallExpr) ir.Node {
 }
 
 // transformCall transforms a normal function/method call. Corresponds to last half
-// (non-conversion, non-builtin part) of typecheck.tcCall.
+// (non-conversion, non-builtin part) of typecheck.tcCall. This code should work even
+// in the case of OCALL/OFUNCINST.
 func transformCall(n *ir.CallExpr) {
 	// n.Type() can be nil for calls with no return value
 	assert(n.Typecheck() == 1)
@@ -148,10 +157,11 @@ func transformCall(n *ir.CallExpr) {
 		n.SetOp(ir.OCALLFUNC)
 	}
 
-	typecheckaste(ir.OCALL, n.X, n.IsDDD, t.Params(), n.Args)
+	typecheckaste(ir.OCALL, n.X, n.IsDDD, t.Params(), n.Args, false)
+	if l.Op() == ir.ODOTMETH && len(deref(n.X.Type().Recv().Type).RParams()) == 0 {
+		typecheck.FixMethodCall(n)
+	}
 	if t.NumResults() == 1 {
-		n.SetType(l.Type().Results().Field(0).Type)
-
 		if n.Op() == ir.OCALLFUNC && n.X.Op() == ir.ONAME {
 			if sym := n.X.(*ir.Name).Sym(); types.IsRuntimePkg(sym.Pkg) && sym.Name == "getg" {
 				// Emit code for runtime.getg() directly instead of calling function.
@@ -185,7 +195,7 @@ func transformCompare(n *ir.BinaryExpr) {
 			aop, _ := typecheck.Assignop(lt, rt)
 			if aop != ir.OXXX {
 				types.CalcSize(lt)
-				if rt.IsInterface() == lt.IsInterface() || lt.Width >= 1<<16 {
+				if lt.HasTParam() || rt.IsInterface() == lt.IsInterface() || lt.Width >= 1<<16 {
 					l = ir.NewConvExpr(base.Pos, aop, rt, l)
 					l.SetTypecheck(1)
 				}
@@ -198,7 +208,7 @@ func transformCompare(n *ir.BinaryExpr) {
 			aop, _ := typecheck.Assignop(rt, lt)
 			if aop != ir.OXXX {
 				types.CalcSize(rt)
-				if rt.IsInterface() == lt.IsInterface() || rt.Width >= 1<<16 {
+				if rt.HasTParam() || rt.IsInterface() == lt.IsInterface() || rt.Width >= 1<<16 {
 					r = ir.NewConvExpr(base.Pos, aop, lt, r)
 					r.SetTypecheck(1)
 				}
@@ -303,6 +313,10 @@ assignOK:
 			r := r.(*ir.TypeAssertExpr)
 			stmt.SetOp(ir.OAS2DOTTYPE)
 			r.SetOp(ir.ODOTTYPE2)
+		case ir.ODYNAMICDOTTYPE:
+			r := r.(*ir.DynamicTypeAssertExpr)
+			stmt.SetOp(ir.OAS2DOTTYPE)
+			r.SetOp(ir.ODYNAMICDOTTYPE2)
 		default:
 			break assignOK
 		}
@@ -323,11 +337,22 @@ assignOK:
 		stmt := stmt.(*ir.AssignListStmt)
 		stmt.SetOp(ir.OAS2FUNC)
 		r := rhs[0].(*ir.CallExpr)
-		r.Use = ir.CallUseList
 		rtyp := r.Type()
 
+		mismatched := false
+		failed := false
 		for i := range lhs {
-			checkLHS(i, rtyp.Field(i).Type)
+			result := rtyp.Field(i).Type
+			checkLHS(i, result)
+
+			if lhs[i].Type() == nil || result == nil {
+				failed = true
+			} else if lhs[i] != ir.BlankNode && !types.Identical(lhs[i].Type(), result) {
+				mismatched = true
+			}
+		}
+		if mismatched && !failed {
+			typecheck.RewriteMultiValueCall(stmt, r)
 		}
 		return
 	}
@@ -340,12 +365,12 @@ assignOK:
 	}
 }
 
-// Corresponds to typecheck.typecheckargs.
+// Corresponds to typecheck.typecheckargs.  Really just deals with multi-value calls.
 func transformArgs(n ir.InitNode) {
 	var list []ir.Node
 	switch n := n.(type) {
 	default:
-		base.Fatalf("typecheckargs %+v", n.Op())
+		base.Fatalf("transformArgs %+v", n.Op())
 	case *ir.CallExpr:
 		list = n.Args
 		if n.IsDDD {
@@ -363,46 +388,13 @@ func transformArgs(n ir.InitNode) {
 		return
 	}
 
-	// Rewrite f(g()) into t1, t2, ... = g(); f(t1, t2, ...).
-
 	// Save n as n.Orig for fmt.go.
 	if ir.Orig(n) == n {
 		n.(ir.OrigNode).SetOrig(ir.SepCopy(n))
 	}
 
-	as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil)
-	as.Rhs.Append(list...)
-
-	// If we're outside of function context, then this call will
-	// be executed during the generated init function. However,
-	// init.go hasn't yet created it. Instead, associate the
-	// temporary variables with  InitTodoFunc for now, and init.go
-	// will reassociate them later when it's appropriate.
-	static := ir.CurFunc == nil
-	if static {
-		ir.CurFunc = typecheck.InitTodoFunc
-	}
-	list = nil
-	for _, f := range t.FieldSlice() {
-		t := typecheck.Temp(f.Type)
-		as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, t))
-		as.Lhs.Append(t)
-		list = append(list, t)
-	}
-	if static {
-		ir.CurFunc = nil
-	}
-
-	switch n := n.(type) {
-	case *ir.CallExpr:
-		n.Args = list
-	case *ir.ReturnStmt:
-		n.Results = list
-	}
-
-	transformAssign(as, as.Lhs, as.Rhs)
-	as.SetTypecheck(1)
-	n.PtrInit().Append(as)
+	// Rewrite f(g()) into t1, t2, ... = g(); f(t1, t2, ...).
+	typecheck.RewriteMultiValueCall(n, list[0])
 }
 
 // assignconvfn converts node n for assignment to type t. Corresponds to
@@ -416,7 +408,10 @@ func assignconvfn(n ir.Node, t *types.Type) ir.Node {
 		return n
 	}
 
-	op, _ := typecheck.Assignop(n.Type(), t)
+	op, why := typecheck.Assignop(n.Type(), t)
+	if op == ir.OXXX {
+		base.Fatalf("found illegal assignment %+v -> %+v; %s", n.Type(), t, why)
+	}
 
 	r := ir.NewConvExpr(base.Pos, op, t, n)
 	r.SetTypecheck(1)
@@ -424,8 +419,11 @@ func assignconvfn(n ir.Node, t *types.Type) ir.Node {
 	return r
 }
 
-// Corresponds to typecheck.typecheckaste.
-func typecheckaste(op ir.Op, call ir.Node, isddd bool, tstruct *types.Type, nl ir.Nodes) {
+// Corresponds to typecheck.typecheckaste, but we add an extra flag convifaceOnly
+// only. If convifaceOnly is true, we only do interface conversion. We use this to do
+// early insertion of CONVIFACE nodes during noder2, when the function or args may
+// have typeparams.
+func typecheckaste(op ir.Op, call ir.Node, isddd bool, tstruct *types.Type, nl ir.Nodes, convifaceOnly bool) {
 	var t *types.Type
 	var i int
 
@@ -444,7 +442,7 @@ func typecheckaste(op ir.Op, call ir.Node, isddd bool, tstruct *types.Type, nl i
 			if isddd {
 				n = nl[i]
 				ir.SetPos(n)
-				if n.Type() != nil {
+				if n.Type() != nil && (!convifaceOnly || t.IsInterface()) {
 					nl[i] = assignconvfn(n, t)
 				}
 				return
@@ -454,7 +452,7 @@ func typecheckaste(op ir.Op, call ir.Node, isddd bool, tstruct *types.Type, nl i
 			for ; i < len(nl); i++ {
 				n = nl[i]
 				ir.SetPos(n)
-				if n.Type() != nil {
+				if n.Type() != nil && (!convifaceOnly || t.IsInterface()) {
 					nl[i] = assignconvfn(n, t.Elem())
 				}
 			}
@@ -463,7 +461,7 @@ func typecheckaste(op ir.Op, call ir.Node, isddd bool, tstruct *types.Type, nl i
 
 		n = nl[i]
 		ir.SetPos(n)
-		if n.Type() != nil {
+		if n.Type() != nil && (!convifaceOnly || t.IsInterface()) {
 			nl[i] = assignconvfn(n, t)
 		}
 		i++
@@ -485,7 +483,7 @@ func transformReturn(rs *ir.ReturnStmt) {
 		return
 	}
 
-	typecheckaste(ir.ORETURN, nil, false, ir.CurFunc.Type().Results(), nl)
+	typecheckaste(ir.ORETURN, nil, false, ir.CurFunc.Type().Results(), nl, false)
 }
 
 // transformSelect transforms a select node, creating an assignment list as needed
@@ -537,13 +535,31 @@ func transformAsOp(n *ir.AssignOpStmt) {
 }
 
 // transformDot transforms an OXDOT (or ODOT) or ODOT, ODOTPTR, ODOTMETH,
-// ODOTINTER, or OCALLPART, as appropriate. It adds in extra nodes as needed to
+// ODOTINTER, or OMETHVALUE, as appropriate. It adds in extra nodes as needed to
 // access embedded fields. Corresponds to typecheck.tcDot.
 func transformDot(n *ir.SelectorExpr, isCall bool) ir.Node {
 	assert(n.Type() != nil && n.Typecheck() == 1)
 	if n.Op() == ir.OXDOT {
 		n = typecheck.AddImplicitDots(n)
 		n.SetOp(ir.ODOT)
+
+		// Set the Selection field and typecheck flag for any new ODOT nodes
+		// added by AddImplicitDots(), and also transform to ODOTPTR if
+		// needed. Equivalent to 'n.X = typecheck(n.X, ctxExpr|ctxType)' in
+		// tcDot.
+		for n1 := n; n1.X.Op() == ir.ODOT; {
+			n1 = n1.X.(*ir.SelectorExpr)
+			if !n1.Implicit() {
+				break
+			}
+			t1 := n1.X.Type()
+			if t1.IsPtr() && !t1.Elem().IsInterface() {
+				t1 = t1.Elem()
+				n1.SetOp(ir.ODOTPTR)
+			}
+			typecheck.Lookdot(n1, t1, 0)
+			n1.SetTypecheck(1)
+		}
 	}
 
 	t := n.X.Type()
@@ -561,8 +577,13 @@ func transformDot(n *ir.SelectorExpr, isCall bool) ir.Node {
 	assert(f != nil)
 
 	if (n.Op() == ir.ODOTINTER || n.Op() == ir.ODOTMETH) && !isCall {
-		n.SetOp(ir.OCALLPART)
-		n.SetType(typecheck.MethodValueWrapper(n).Type())
+		n.SetOp(ir.OMETHVALUE)
+		if len(n.X.Type().RParams()) > 0 || n.X.Type().IsPtr() && len(n.X.Type().Elem().RParams()) > 0 {
+			// TODO: MethodValueWrapper needed for generics?
+			// Or did we successfully desugar all that at stencil time?
+			return n
+		}
+		n.SetType(typecheck.NewMethodType(n.Type(), nil))
 	}
 	return n
 }
@@ -594,7 +615,11 @@ func transformMethodExpr(n *ir.SelectorExpr) (res ir.Node) {
 
 	s := n.Sel
 	m := typecheck.Lookdot1(n, s, t, ms, 0)
-	assert(m != nil)
+	if !t.HasShape() {
+		// It's OK to not find the method if t is instantiated by shape types,
+		// because we will use the methods on the generic type anyway.
+		assert(m != nil)
+	}
 
 	n.SetOp(ir.OMETHEXPR)
 	n.Selection = m
@@ -911,9 +936,7 @@ func transformCompLit(n *ir.CompLitExpr) (res ir.Node) {
 
 				f := t.Field(i)
 				n1 = assignconvfn(n1, f.Type)
-				sk := ir.NewStructKeyExpr(base.Pos, f.Sym, n1)
-				sk.Offset = f.Offset
-				ls[i] = sk
+				ls[i] = ir.NewStructKeyExpr(base.Pos, f, n1)
 			}
 			assert(len(ls) >= t.NumFields())
 		} else {
@@ -922,33 +945,26 @@ func transformCompLit(n *ir.CompLitExpr) (res ir.Node) {
 			for i, l := range ls {
 				ir.SetPos(l)
 
-				if l.Op() == ir.OKEY {
-					kv := l.(*ir.KeyExpr)
-					key := kv.Key
+				kv := l.(*ir.KeyExpr)
+				key := kv.Key
 
-					// Sym might have resolved to name in other top-level
-					// package, because of import dot. Redirect to correct sym
-					// before we do the lookup.
-					s := key.Sym()
-					if id, ok := key.(*ir.Ident); ok && typecheck.DotImportRefs[id] != nil {
-						s = typecheck.Lookup(s.Name)
-					}
-
-					// An OXDOT uses the Sym field to hold
-					// the field to the right of the dot,
-					// so s will be non-nil, but an OXDOT
-					// is never a valid struct literal key.
-					assert(!(s == nil || s.Pkg != types.LocalPkg || key.Op() == ir.OXDOT || s.IsBlank()))
-
-					l = ir.NewStructKeyExpr(l.Pos(), s, kv.Value)
-					ls[i] = l
+				// Sym might have resolved to name in other top-level
+				// package, because of import dot. Redirect to correct sym
+				// before we do the lookup.
+				s := key.Sym()
+				if id, ok := key.(*ir.Ident); ok && typecheck.DotImportRefs[id] != nil {
+					s = typecheck.Lookup(s.Name)
 				}
 
-				assert(l.Op() == ir.OSTRUCTKEY)
-				l := l.(*ir.StructKeyExpr)
+				// An OXDOT uses the Sym field to hold
+				// the field to the right of the dot,
+				// so s will be non-nil, but an OXDOT
+				// is never a valid struct literal key.
+				assert(!(s == nil || s.Pkg != types.LocalPkg || key.Op() == ir.OXDOT || s.IsBlank()))
 
-				f := typecheck.Lookdot1(nil, l.Field, t, t.Fields(), 0)
-				l.Offset = f.Offset
+				f := typecheck.Lookdot1(nil, s, t, t.Fields(), 0)
+				l := ir.NewStructKeyExpr(l.Pos(), f, kv.Value)
+				ls[i] = l
 
 				l.Value = assignconvfn(l.Value, f.Type)
 			}
diff --git a/src/cmd/compile/internal/noder/types.go b/src/cmd/compile/internal/noder/types.go
index 8680559a412..8d596e599ed 100644
--- a/src/cmd/compile/internal/noder/types.go
+++ b/src/cmd/compile/internal/noder/types.go
@@ -39,6 +39,11 @@ func (g *irgen) typ(typ types2.Type) *types.Type {
 	// recursive types have been fully constructed before we call CheckSize.
 	if res != nil && !res.IsUntyped() && !res.IsFuncArgStruct() && !res.HasTParam() {
 		types.CheckSize(res)
+		if res.IsPtr() {
+			// Pointers always have their size set, even though their element
+			// may not have its size set.
+			types.CheckSize(res.Elem())
+		}
 	}
 	return res
 }
@@ -68,8 +73,10 @@ func instTypeName2(name string, targs []types2.Type) string {
 		if i > 0 {
 			b.WriteByte(',')
 		}
+		// Include package names for all types, including typeparams, to
+		// make sure type arguments are uniquely specified.
 		tname := types2.TypeString(targ,
-			func(*types2.Package) string { return "" })
+			func(pkg *types2.Package) string { return pkg.Name() })
 		if strings.Index(tname, ", ") >= 0 {
 			// types2.TypeString puts spaces after a comma in a type
 			// list, but we don't want spaces in our actual type names
@@ -89,50 +96,49 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 	case *types2.Basic:
 		return g.basic(typ)
 	case *types2.Named:
-		if typ.TParams() != nil {
+		// If tparams is set, but targs is not, typ is a base generic
+		// type. typ is appearing as part of the source type of an alias,
+		// since that is the only use of a generic type that doesn't
+		// involve instantiation. We just translate the named type in the
+		// normal way below using g.obj().
+		if typ.TParams() != nil && typ.TArgs() != nil {
 			// typ is an instantiation of a defined (named) generic type.
 			// This instantiation should also be a defined (named) type.
 			// types2 gives us the substituted type in t.Underlying()
 			// The substituted type may or may not still have type
 			// params. We might, for example, be substituting one type
 			// param for another type param.
-
-			if typ.TArgs() == nil {
-				base.Fatalf("In typ0, Targs should be set if TParams is set")
-			}
-
-			// When converted to types.Type, typ must have a name,
-			// based on the names of the type arguments. We need a
-			// name to deal with recursive generic types (and it also
-			// looks better when printing types).
+			//
+			// When converted to types.Type, typ has a unique name,
+			// based on the names of the type arguments.
 			instName := instTypeName2(typ.Obj().Name(), typ.TArgs())
 			s := g.pkg(typ.Obj().Pkg()).Lookup(instName)
 			if s.Def != nil {
-				// We have already encountered this instantiation,
-				// so use the type we previously created, since there
+				// We have already encountered this instantiation.
+				// Use the type we previously created, since there
 				// must be exactly one instance of a defined type.
 				return s.Def.Type()
 			}
 
 			// Create a forwarding type first and put it in the g.typs
-			// map, in order to deal with recursive generic types.
-			// Fully set up the extra ntyp information (Def, RParams,
-			// which may set HasTParam) before translating the
-			// underlying type itself, so we handle recursion
-			// correctly, including via method signatures.
-			ntyp := newIncompleteNamedType(g.pos(typ.Obj().Pos()), s)
+			// map, in order to deal with recursive generic types
+			// (including via method signatures).. Set up the extra
+			// ntyp information (Def, RParams, which may set
+			// HasTParam) before translating the underlying type
+			// itself, so we handle recursion correctly.
+			ntyp := typecheck.NewIncompleteNamedType(g.pos(typ.Obj().Pos()), s)
 			g.typs[typ] = ntyp
 
 			// If ntyp still has type params, then we must be
 			// referencing something like 'value[T2]', as when
-			// specifying the generic receiver of a method,
-			// where value was defined as "type value[T any]
-			// ...". Save the type args, which will now be the
-			// new type  of the current type.
+			// specifying the generic receiver of a method, where
+			// value was defined as "type value[T any] ...". Save the
+			// type args, which will now be the new typeparams of the
+			// current type.
 			//
 			// If ntyp does not have type params, we are saving the
-			// concrete types used to instantiate this type. We'll use
-			// these when instantiating the methods of the
+			// non-generic types used to instantiate this type. We'll
+			// use these when instantiating the methods of the
 			// instantiated type.
 			rparams := make([]*types.Type, len(typ.TArgs()))
 			for i, targ := range typ.TArgs() {
@@ -143,6 +149,8 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 
 			ntyp.SetUnderlying(g.typ1(typ.Underlying()))
 			g.fillinMethods(typ, ntyp)
+			// Save the symbol for the base generic type.
+			ntyp.OrigSym = g.pkg(typ.Obj().Pkg()).Lookup(typ.Obj().Name())
 			return ntyp
 		}
 		obj := g.obj(typ.Obj())
@@ -183,12 +191,9 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 		for i := range embeddeds {
 			// TODO(mdempsky): Get embedding position.
 			e := typ.EmbeddedType(i)
-			if t := types2.AsInterface(e); t != nil && t.IsComparable() {
-				// Ignore predefined type 'comparable', since it
-				// doesn't resolve and it doesn't have any
-				// relevant methods.
-				continue
-			}
+
+			// With Go 1.18, an embedded element can be any type, not
+			// just an interface.
 			embeddeds[j] = types.NewField(src.NoXPos, nil, g.typ1(e))
 			j++
 		}
@@ -204,20 +209,39 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 		return types.NewInterface(g.tpkg(typ), append(embeddeds, methods...))
 
 	case *types2.TypeParam:
-		tp := types.NewTypeParam(g.tpkg(typ))
 		// Save the name of the type parameter in the sym of the type.
 		// Include the types2 subscript in the sym name
-		sym := g.pkg(typ.Obj().Pkg()).Lookup(types2.TypeString(typ, func(*types2.Package) string { return "" }))
-		tp.SetSym(sym)
+		pkg := g.tpkg(typ)
+		sym := pkg.Lookup(types2.TypeString(typ, func(*types2.Package) string { return "" }))
+		if sym.Def != nil {
+			// Make sure we use the same type param type for the same
+			// name, whether it is created during types1-import or
+			// this types2-to-types1 translation.
+			return sym.Def.Type()
+		}
+		tp := types.NewTypeParam(sym, typ.Index())
+		nname := ir.NewDeclNameAt(g.pos(typ.Obj().Pos()), ir.OTYPE, sym)
+		sym.Def = nname
+		nname.SetType(tp)
+		tp.SetNod(nname)
 		// Set g.typs[typ] in case the bound methods reference typ.
 		g.typs[typ] = tp
 
-		// TODO(danscales): we don't currently need to use the bounds
-		// anywhere, so eventually we can probably remove.
-		bound := g.typ1(typ.Bound())
-		*tp.Methods() = *bound.Methods()
+		bound := g.typ1(typ.Constraint())
+		tp.SetBound(bound)
 		return tp
 
+	case *types2.Union:
+		nt := typ.Len()
+		tlist := make([]*types.Type, nt)
+		tildes := make([]bool, nt)
+		for i := range tlist {
+			t := typ.Term(i)
+			tlist[i] = g.typ1(t.Type())
+			tildes[i] = t.Tilde()
+		}
+		return types.NewUnion(tlist, tildes)
+
 	case *types2.Tuple:
 		// Tuples are used for the type of a function call (i.e. the
 		// return value of the function).
@@ -243,19 +267,23 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 // and for actually generating the methods for instantiated types.
 func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
 	if typ.NumMethods() != 0 {
-		targs := make([]ir.Node, len(typ.TArgs()))
+		targs := make([]*types.Type, len(typ.TArgs()))
 		for i, targ := range typ.TArgs() {
-			targs[i] = ir.TypeNode(g.typ1(targ))
+			targs[i] = g.typ1(targ)
 		}
 
 		methods := make([]*types.Field, typ.NumMethods())
 		for i := range methods {
 			m := typ.Method(i)
-			meth := g.obj(m)
-			recvType := types2.AsSignature(m.Type()).Recv().Type()
-			ptr := types2.AsPointer(recvType)
-			if ptr != nil {
-				recvType = ptr.Elem()
+			recvType := deref2(types2.AsSignature(m.Type()).Recv().Type())
+			var meth *ir.Name
+			if m.Pkg() != g.self {
+				// Imported methods cannot be loaded by name (what
+				// g.obj() does) - they must be loaded via their
+				// type.
+				meth = g.obj(recvType.(*types2.Named).Obj()).Type().Methods().Index(i).Nname.(*ir.Name)
+			} else {
+				meth = g.obj(m)
 			}
 			if recvType != types2.Type(typ) {
 				// Unfortunately, meth is the type of the method of the
@@ -276,18 +304,21 @@ func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
 				} else {
 					meth2 = ir.NewNameAt(meth.Pos(), newsym)
 					rparams := types2.AsSignature(m.Type()).RParams()
-					tparams := make([]*types.Field, len(rparams))
-					for i, rparam := range rparams {
-						tparams[i] = types.NewField(src.NoXPos, nil, g.typ1(rparam.Type()))
+					tparams := make([]*types.Type, rparams.Len())
+					for i := range tparams {
+						tparams[i] = g.typ1(rparams.At(i).Type())
 					}
 					assert(len(tparams) == len(targs))
-					subst := &subster{
-						g:       g,
-						tparams: tparams,
-						targs:   targs,
+					ts := typecheck.Tsubster{
+						Tparams: tparams,
+						Targs:   targs,
 					}
 					// Do the substitution of the type
-					meth2.SetType(subst.typ(meth.Type()))
+					meth2.SetType(ts.Typ(meth.Type()))
+					// Add any new fully instantiated types
+					// seen during the substitution to
+					// g.instTypeList.
+					g.instTypeList = append(g.instTypeList, ts.InstTypeList...)
 					newsym.Def = meth2
 				}
 				meth = meth2
@@ -296,7 +327,7 @@ func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
 			methods[i].Nname = meth
 		}
 		ntyp.Methods().Set(methods)
-		if !ntyp.HasTParam() {
+		if !ntyp.HasTParam() && !ntyp.HasShape() {
 			// Generate all the methods for a new fully-instantiated type.
 			g.instTypeList = append(g.instTypeList, ntyp)
 		}
@@ -305,9 +336,9 @@ func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
 
 func (g *irgen) signature(recv *types.Field, sig *types2.Signature) *types.Type {
 	tparams2 := sig.TParams()
-	tparams := make([]*types.Field, len(tparams2))
+	tparams := make([]*types.Field, tparams2.Len())
 	for i := range tparams {
-		tp := tparams2[i]
+		tp := tparams2.At(i)
 		tparams[i] = types.NewField(g.pos(tp), g.sym(tp), g.typ1(tp.Type()))
 	}
 
@@ -346,7 +377,7 @@ func (g *irgen) selector(obj types2.Object) *types.Sym {
 	return pkg.Lookup(name)
 }
 
-// tpkg returns the package that a function, interface, or struct type
+// tpkg returns the package that a function, interface, struct, or typeparam type
 // expression appeared in.
 //
 // Caveat: For the degenerate types "func()", "interface{}", and
@@ -356,36 +387,39 @@ func (g *irgen) selector(obj types2.Object) *types.Sym {
 // particular types is because go/types does *not* report it for
 // them. So in practice this limitation is probably moot.
 func (g *irgen) tpkg(typ types2.Type) *types.Pkg {
-	anyObj := func() types2.Object {
-		switch typ := typ.(type) {
-		case *types2.Signature:
-			if recv := typ.Recv(); recv != nil {
-				return recv
-			}
-			if params := typ.Params(); params.Len() > 0 {
-				return params.At(0)
-			}
-			if results := typ.Results(); results.Len() > 0 {
-				return results.At(0)
-			}
-		case *types2.Struct:
-			if typ.NumFields() > 0 {
-				return typ.Field(0)
-			}
-		case *types2.Interface:
-			if typ.NumExplicitMethods() > 0 {
-				return typ.ExplicitMethod(0)
-			}
-		}
-		return nil
-	}
-
-	if obj := anyObj(); obj != nil {
+	if obj := anyObj(typ); obj != nil {
 		return g.pkg(obj.Pkg())
 	}
 	return types.LocalPkg
 }
 
+// anyObj returns some object accessible from typ, if any.
+func anyObj(typ types2.Type) types2.Object {
+	switch typ := typ.(type) {
+	case *types2.Signature:
+		if recv := typ.Recv(); recv != nil {
+			return recv
+		}
+		if params := typ.Params(); params.Len() > 0 {
+			return params.At(0)
+		}
+		if results := typ.Results(); results.Len() > 0 {
+			return results.At(0)
+		}
+	case *types2.Struct:
+		if typ.NumFields() > 0 {
+			return typ.Field(0)
+		}
+	case *types2.Interface:
+		if typ.NumExplicitMethods() > 0 {
+			return typ.ExplicitMethod(0)
+		}
+	case *types2.TypeParam:
+		return typ.Obj()
+	}
+	return nil
+}
+
 func (g *irgen) basic(typ *types2.Basic) *types.Type {
 	switch typ.Name() {
 	case "byte":
@@ -430,3 +464,11 @@ var dirs = [...]types.ChanDir{
 	types2.SendOnly: types.Csend,
 	types2.RecvOnly: types.Crecv,
 }
+
+// deref2 does a single deref of types2 type t, if it is a pointer type.
+func deref2(t types2.Type) types2.Type {
+	if ptr := types2.AsPointer(t); ptr != nil {
+		t = ptr.Elem()
+	}
+	return t
+}
diff --git a/src/cmd/compile/internal/noder/unified.go b/src/cmd/compile/internal/noder/unified.go
new file mode 100644
index 00000000000..9f80ca000de
--- /dev/null
+++ b/src/cmd/compile/internal/noder/unified.go
@@ -0,0 +1,340 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"bytes"
+	"fmt"
+	"internal/goversion"
+	"io"
+	"runtime"
+	"sort"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/inline"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/typecheck"
+	"cmd/compile/internal/types"
+	"cmd/compile/internal/types2"
+	"cmd/internal/src"
+)
+
+// localPkgReader holds the package reader used for reading the local
+// package. It exists so the unified IR linker can refer back to it
+// later.
+var localPkgReader *pkgReader
+
+// unified construct the local package's IR from syntax's AST.
+//
+// The pipeline contains 2 steps:
+//
+// (1) Generate package export data "stub".
+//
+// (2) Generate package IR from package export data.
+//
+// The package data "stub" at step (1) contains everything from the local package,
+// but nothing that have been imported. When we're actually writing out export data
+// to the output files (see writeNewExport function), we run the "linker", which does
+// a few things:
+//
+// + Updates compiler extensions data (e.g., inlining cost, escape analysis results).
+//
+// + Handles re-exporting any transitive dependencies.
+//
+// + Prunes out any unnecessary details (e.g., non-inlineable functions, because any
+//   downstream importers only care about inlinable functions).
+//
+// The source files are typechecked twice, once before writing export data
+// using types2 checker, once after read export data using gc/typecheck.
+// This duplication of work will go away once we always use types2 checker,
+// we can remove the gc/typecheck pass. The reason it is still here:
+//
+// + It reduces engineering costs in maintaining a fork of typecheck
+//   (e.g., no need to backport fixes like CL 327651).
+//
+// + It makes it easier to pass toolstash -cmp.
+//
+// + Historically, we would always re-run the typechecker after import, even though
+//   we know the imported data is valid. It's not ideal, but also not causing any
+//   problem either.
+//
+// + There's still transformation that being done during gc/typecheck, like rewriting
+//   multi-valued function call, or transform ir.OINDEX -> ir.OINDEXMAP.
+//
+// Using syntax+types2 tree, which already has a complete representation of generics,
+// the unified IR has the full typed AST for doing introspection during step (1).
+// In other words, we have all necessary information to build the generic IR form
+// (see writer.captureVars for an example).
+func unified(noders []*noder) {
+	inline.NewInline = InlineCall
+
+	if !quirksMode() {
+		writeNewExportFunc = writeNewExport
+	} else if base.Flag.G != 0 {
+		base.Errorf("cannot use -G and -d=quirksmode together")
+	}
+
+	newReadImportFunc = func(data string, pkg1 *types.Pkg, check *types2.Checker, packages map[string]*types2.Package) (pkg2 *types2.Package, err error) {
+		pr := newPkgDecoder(pkg1.Path, data)
+
+		// Read package descriptors for both types2 and compiler backend.
+		readPackage(newPkgReader(pr), pkg1)
+		pkg2 = readPackage2(check, packages, pr)
+		return
+	}
+
+	data := writePkgStub(noders)
+
+	// We already passed base.Flag.Lang to types2 to handle validating
+	// the user's source code. Bump it up now to the current version and
+	// re-parse, so typecheck doesn't complain if we construct IR that
+	// utilizes newer Go features.
+	base.Flag.Lang = fmt.Sprintf("go1.%d", goversion.Version)
+	types.ParseLangFlag()
+
+	assert(types.LocalPkg.Path == "")
+	types.LocalPkg.Height = 0 // reset so pkgReader.pkgIdx doesn't complain
+	target := typecheck.Target
+
+	typecheck.TypecheckAllowed = true
+
+	localPkgReader = newPkgReader(newPkgDecoder(types.LocalPkg.Path, data))
+	readPackage(localPkgReader, types.LocalPkg)
+
+	r := localPkgReader.newReader(relocMeta, privateRootIdx, syncPrivate)
+	r.ext = r
+	r.pkgInit(types.LocalPkg, target)
+
+	// Type-check any top-level assignments. We ignore non-assignments
+	// here because other declarations are typechecked as they're
+	// constructed.
+	for i, ndecls := 0, len(target.Decls); i < ndecls; i++ {
+		switch n := target.Decls[i]; n.Op() {
+		case ir.OAS, ir.OAS2:
+			target.Decls[i] = typecheck.Stmt(n)
+		}
+	}
+
+	// Don't use range--bodyIdx can add closures to todoBodies.
+	for len(todoBodies) > 0 {
+		// The order we expand bodies doesn't matter, so pop from the end
+		// to reduce todoBodies reallocations if it grows further.
+		fn := todoBodies[len(todoBodies)-1]
+		todoBodies = todoBodies[:len(todoBodies)-1]
+
+		pri, ok := bodyReader[fn]
+		assert(ok)
+		pri.funcBody(fn)
+
+		// Instantiated generic function: add to Decls for typechecking
+		// and compilation.
+		if fn.OClosure == nil && len(pri.dict.targs) != 0 {
+			target.Decls = append(target.Decls, fn)
+		}
+	}
+	todoBodies = nil
+
+	if !quirksMode() {
+		// TODO(mdempsky): Investigate generating wrappers in quirks mode too.
+		r.wrapTypes(target)
+	}
+
+	// Check that nothing snuck past typechecking.
+	for _, n := range target.Decls {
+		if n.Typecheck() == 0 {
+			base.FatalfAt(n.Pos(), "missed typecheck: %v", n)
+		}
+
+		// For functions, check that at least their first statement (if
+		// any) was typechecked too.
+		if fn, ok := n.(*ir.Func); ok && len(fn.Body) != 0 {
+			if stmt := fn.Body[0]; stmt.Typecheck() == 0 {
+				base.FatalfAt(stmt.Pos(), "missed typecheck: %v", stmt)
+			}
+		}
+	}
+
+	base.ExitIfErrors() // just in case
+}
+
+// writePkgStub type checks the given parsed source files,
+// writes an export data package stub representing them,
+// and returns the result.
+func writePkgStub(noders []*noder) string {
+	m, pkg, info := checkFiles(noders)
+
+	pw := newPkgWriter(m, pkg, info)
+
+	pw.collectDecls(noders)
+
+	publicRootWriter := pw.newWriter(relocMeta, syncPublic)
+	privateRootWriter := pw.newWriter(relocMeta, syncPrivate)
+
+	assert(publicRootWriter.idx == publicRootIdx)
+	assert(privateRootWriter.idx == privateRootIdx)
+
+	{
+		w := publicRootWriter
+		w.pkg(pkg)
+		w.bool(false) // has init; XXX
+
+		scope := pkg.Scope()
+		names := scope.Names()
+		w.len(len(names))
+		for _, name := range scope.Names() {
+			w.obj(scope.Lookup(name), nil)
+		}
+
+		w.sync(syncEOF)
+		w.flush()
+	}
+
+	{
+		w := privateRootWriter
+		w.ext = w
+		w.pkgInit(noders)
+		w.flush()
+	}
+
+	var sb bytes.Buffer // TODO(mdempsky): strings.Builder after #44505 is resolved
+	pw.dump(&sb)
+
+	// At this point, we're done with types2. Make sure the package is
+	// garbage collected.
+	freePackage(pkg)
+
+	return sb.String()
+}
+
+// freePackage ensures the given package is garbage collected.
+func freePackage(pkg *types2.Package) {
+	// The GC test below relies on a precise GC that runs finalizers as
+	// soon as objects are unreachable. Our implementation provides
+	// this, but other/older implementations may not (e.g., Go 1.4 does
+	// not because of #22350). To avoid imposing unnecessary
+	// restrictions on the GOROOT_BOOTSTRAP toolchain, we skip the test
+	// during bootstrapping.
+	if base.CompilerBootstrap {
+		return
+	}
+
+	// Set a finalizer on pkg so we can detect if/when it's collected.
+	done := make(chan struct{})
+	runtime.SetFinalizer(pkg, func(*types2.Package) { close(done) })
+
+	// Important: objects involved in cycles are not finalized, so zero
+	// out pkg to break its cycles and allow the finalizer to run.
+	*pkg = types2.Package{}
+
+	// It typically takes just 1 or 2 cycles to release pkg, but it
+	// doesn't hurt to try a few more times.
+	for i := 0; i < 10; i++ {
+		select {
+		case <-done:
+			return
+		default:
+			runtime.GC()
+		}
+	}
+
+	base.Fatalf("package never finalized")
+}
+
+func readPackage(pr *pkgReader, importpkg *types.Pkg) {
+	r := pr.newReader(relocMeta, publicRootIdx, syncPublic)
+
+	pkg := r.pkg()
+	assert(pkg == importpkg)
+
+	if r.bool() {
+		sym := pkg.Lookup(".inittask")
+		task := ir.NewNameAt(src.NoXPos, sym)
+		task.Class = ir.PEXTERN
+		sym.Def = task
+	}
+
+	for i, n := 0, r.len(); i < n; i++ {
+		r.sync(syncObject)
+		assert(!r.bool())
+		idx := r.reloc(relocObj)
+		assert(r.len() == 0)
+
+		path, name, code := r.p.peekObj(idx)
+		if code != objStub {
+			objReader[types.NewPkg(path, "").Lookup(name)] = pkgReaderIndex{pr, idx, nil}
+		}
+	}
+}
+
+func writeNewExport(out io.Writer) {
+	l := linker{
+		pw: newPkgEncoder(),
+
+		pkgs:  make(map[string]int),
+		decls: make(map[*types.Sym]int),
+	}
+
+	publicRootWriter := l.pw.newEncoder(relocMeta, syncPublic)
+	assert(publicRootWriter.idx == publicRootIdx)
+
+	var selfPkgIdx int
+
+	{
+		pr := localPkgReader
+		r := pr.newDecoder(relocMeta, publicRootIdx, syncPublic)
+
+		r.sync(syncPkg)
+		selfPkgIdx = l.relocIdx(pr, relocPkg, r.reloc(relocPkg))
+
+		r.bool() // has init
+
+		for i, n := 0, r.len(); i < n; i++ {
+			r.sync(syncObject)
+			assert(!r.bool())
+			idx := r.reloc(relocObj)
+			assert(r.len() == 0)
+
+			xpath, xname, xtag := pr.peekObj(idx)
+			assert(xpath == pr.pkgPath)
+			assert(xtag != objStub)
+
+			if types.IsExported(xname) {
+				l.relocIdx(pr, relocObj, idx)
+			}
+		}
+
+		r.sync(syncEOF)
+	}
+
+	{
+		var idxs []int
+		for _, idx := range l.decls {
+			idxs = append(idxs, idx)
+		}
+		sort.Ints(idxs)
+
+		w := publicRootWriter
+
+		w.sync(syncPkg)
+		w.reloc(relocPkg, selfPkgIdx)
+
+		w.bool(typecheck.Lookup(".inittask").Def != nil)
+
+		w.len(len(idxs))
+		for _, idx := range idxs {
+			w.sync(syncObject)
+			w.bool(false)
+			w.reloc(relocObj, idx)
+			w.len(0)
+		}
+
+		w.sync(syncEOF)
+		w.flush()
+	}
+
+	l.pw.dump(out)
+}
diff --git a/src/cmd/compile/internal/noder/unified_test.go b/src/cmd/compile/internal/noder/unified_test.go
new file mode 100644
index 00000000000..96cc66f775d
--- /dev/null
+++ b/src/cmd/compile/internal/noder/unified_test.go
@@ -0,0 +1,153 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder_test
+
+import (
+	"encoding/json"
+	"flag"
+	exec "internal/execabs"
+	"os"
+	"reflect"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+var (
+	flagPkgs     = flag.String("pkgs", "std", "list of packages to compare (ignored in -short mode)")
+	flagAll      = flag.Bool("all", false, "enable testing of all GOOS/GOARCH targets")
+	flagParallel = flag.Bool("parallel", false, "test GOOS/GOARCH targets in parallel")
+)
+
+// TestUnifiedCompare implements a test similar to running:
+//
+//	$ go build -toolexec="toolstash -cmp" std
+//
+// The -pkgs flag controls the list of packages tested.
+//
+// By default, only the native GOOS/GOARCH target is enabled. The -all
+// flag enables testing of non-native targets. The -parallel flag
+// additionally enables testing of targets in parallel.
+//
+// Caution: Testing all targets is very resource intensive! On an IBM
+// P920 (dual Intel Xeon Gold 6154 CPUs; 36 cores, 192GB RAM), testing
+// all targets in parallel takes about 5 minutes. Using the 'go test'
+// command's -run flag for subtest matching is recommended for less
+// powerful machines.
+func TestUnifiedCompare(t *testing.T) {
+	targets, err := exec.Command("go", "tool", "dist", "list").Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, target := range strings.Fields(string(targets)) {
+		t.Run(target, func(t *testing.T) {
+			parts := strings.Split(target, "/")
+			goos, goarch := parts[0], parts[1]
+
+			if !(*flagAll || goos == runtime.GOOS && goarch == runtime.GOARCH) {
+				t.Skip("skipping non-native target (use -all to enable)")
+			}
+			if *flagParallel {
+				t.Parallel()
+			}
+
+			pkgs1 := loadPackages(t, goos, goarch, "-d=unified=0 -d=inlfuncswithclosures=0 -d=unifiedquirks=1 -G=0")
+			pkgs2 := loadPackages(t, goos, goarch, "-d=unified=1 -d=inlfuncswithclosures=0 -d=unifiedquirks=1 -G=0")
+
+			if len(pkgs1) != len(pkgs2) {
+				t.Fatalf("length mismatch: %v != %v", len(pkgs1), len(pkgs2))
+			}
+
+			for i := range pkgs1 {
+				pkg1 := pkgs1[i]
+				pkg2 := pkgs2[i]
+
+				path := pkg1.ImportPath
+				if path != pkg2.ImportPath {
+					t.Fatalf("mismatched paths: %q != %q", path, pkg2.ImportPath)
+				}
+
+				// Packages that don't have any source files (e.g., packages
+				// unsafe, embed/internal/embedtest, and cmd/internal/moddeps).
+				if pkg1.Export == "" && pkg2.Export == "" {
+					continue
+				}
+
+				if pkg1.BuildID == pkg2.BuildID {
+					t.Errorf("package %q: build IDs unexpectedly matched", path)
+				}
+
+				// Unlike toolstash -cmp, we're comparing the same compiler
+				// binary against itself, just with different flags. So we
+				// don't need to worry about skipping over mismatched version
+				// strings, but we do need to account for differing build IDs.
+				//
+				// Fortunately, build IDs are cryptographic 256-bit hashes,
+				// and cmd/go provides us with them up front. So we can just
+				// use them as delimeters to split the files, and then check
+				// that the substrings are all equal.
+				file1 := strings.Split(readFile(t, pkg1.Export), pkg1.BuildID)
+				file2 := strings.Split(readFile(t, pkg2.Export), pkg2.BuildID)
+				if !reflect.DeepEqual(file1, file2) {
+					t.Errorf("package %q: compile output differs", path)
+				}
+			}
+		})
+	}
+}
+
+type pkg struct {
+	ImportPath string
+	Export     string
+	BuildID    string
+	Incomplete bool
+}
+
+func loadPackages(t *testing.T, goos, goarch, gcflags string) []pkg {
+	args := []string{"list", "-e", "-export", "-json", "-gcflags=all=" + gcflags, "--"}
+	if testing.Short() {
+		t.Log("short testing mode; only testing package runtime")
+		args = append(args, "runtime")
+	} else {
+		args = append(args, strings.Fields(*flagPkgs)...)
+	}
+
+	cmd := exec.Command("go", args...)
+	cmd.Env = append(os.Environ(), "GOOS="+goos, "GOARCH="+goarch)
+	cmd.Stderr = os.Stderr
+	t.Logf("running %v", cmd)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	var res []pkg
+	for dec := json.NewDecoder(stdout); dec.More(); {
+		var pkg pkg
+		if err := dec.Decode(&pkg); err != nil {
+			t.Fatal(err)
+		}
+		if pkg.Incomplete {
+			t.Fatalf("incomplete package: %q", pkg.ImportPath)
+		}
+		res = append(res, pkg)
+	}
+	if err := cmd.Wait(); err != nil {
+		t.Fatal(err)
+	}
+	return res
+}
+
+func readFile(t *testing.T, name string) string {
+	buf, err := os.ReadFile(name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(buf)
+}
diff --git a/src/cmd/compile/internal/noder/validate.go b/src/cmd/compile/internal/noder/validate.go
index b926222c89c..68a059b96f4 100644
--- a/src/cmd/compile/internal/noder/validate.go
+++ b/src/cmd/compile/internal/noder/validate.go
@@ -55,7 +55,15 @@ func (g *irgen) validate(n syntax.Node) {
 	case *syntax.CallExpr:
 		tv := g.info.Types[n.Fun]
 		if tv.IsBuiltin() {
-			switch builtin := n.Fun.(type) {
+			fun := n.Fun
+			for {
+				builtin, ok := fun.(*syntax.ParenExpr)
+				if !ok {
+					break
+				}
+				fun = builtin.X
+			}
+			switch builtin := fun.(type) {
 			case *syntax.Name:
 				g.validateBuiltin(builtin.Value, n)
 			case *syntax.SelectorExpr:
diff --git a/src/cmd/compile/internal/noder/writer.go b/src/cmd/compile/internal/noder/writer.go
new file mode 100644
index 00000000000..d971bd0d164
--- /dev/null
+++ b/src/cmd/compile/internal/noder/writer.go
@@ -0,0 +1,1885 @@
+// UNREVIEWED
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package noder
+
+import (
+	"fmt"
+	"go/constant"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/syntax"
+	"cmd/compile/internal/types2"
+)
+
+type pkgWriter struct {
+	pkgEncoder
+
+	m      posMap
+	curpkg *types2.Package
+	info   *types2.Info
+
+	posBasesIdx map[*syntax.PosBase]int
+	pkgsIdx     map[*types2.Package]int
+	typsIdx     map[types2.Type]int
+	globalsIdx  map[types2.Object]int
+
+	funDecls map[*types2.Func]*syntax.FuncDecl
+	typDecls map[*types2.TypeName]typeDeclGen
+
+	linknames  map[types2.Object]string
+	cgoPragmas [][]string
+
+	dups dupTypes
+}
+
+func newPkgWriter(m posMap, pkg *types2.Package, info *types2.Info) *pkgWriter {
+	return &pkgWriter{
+		pkgEncoder: newPkgEncoder(),
+
+		m:      m,
+		curpkg: pkg,
+		info:   info,
+
+		pkgsIdx:    make(map[*types2.Package]int),
+		globalsIdx: make(map[types2.Object]int),
+		typsIdx:    make(map[types2.Type]int),
+
+		posBasesIdx: make(map[*syntax.PosBase]int),
+
+		funDecls: make(map[*types2.Func]*syntax.FuncDecl),
+		typDecls: make(map[*types2.TypeName]typeDeclGen),
+
+		linknames: make(map[types2.Object]string),
+	}
+}
+
+func (pw *pkgWriter) errorf(p poser, msg string, args ...interface{}) {
+	base.ErrorfAt(pw.m.pos(p), msg, args...)
+}
+
+func (pw *pkgWriter) fatalf(p poser, msg string, args ...interface{}) {
+	base.FatalfAt(pw.m.pos(p), msg, args...)
+}
+
+func (pw *pkgWriter) unexpected(what string, p poser) {
+	pw.fatalf(p, "unexpected %s: %v (%T)", what, p, p)
+}
+
+type writer struct {
+	p *pkgWriter
+
+	encoder
+
+	// For writing out object descriptions, ext points to the extension
+	// writer for where we can write the compiler's private extension
+	// details for the object.
+	//
+	// TODO(mdempsky): This is a little hacky, but works easiest with
+	// the way things are currently.
+	ext *writer
+
+	// TODO(mdempsky): We should be able to prune localsIdx whenever a
+	// scope closes, and then maybe we can just use the same map for
+	// storing the TypeParams too (as their TypeName instead).
+
+	// variables declared within this function
+	localsIdx map[*types2.Var]int
+
+	closureVars    []posObj
+	closureVarsIdx map[*types2.Var]int
+
+	dict    *writerDict
+	derived bool
+}
+
+// A writerDict tracks types and objects that are used by a declaration.
+type writerDict struct {
+	implicits []*types2.TypeName
+
+	// derived is a slice of type indices for computing derived types
+	// (i.e., types that depend on the declaration's type parameters).
+	derived []derivedInfo
+
+	// derivedIdx maps a Type to its corresponding index within the
+	// derived slice, if present.
+	derivedIdx map[types2.Type]int
+
+	// funcs lists references to generic functions that were
+	// instantiated with derived types (i.e., that require
+	// sub-dictionaries when called at run time).
+	funcs []objInfo
+}
+
+type derivedInfo struct {
+	idx    int
+	needed bool
+}
+
+type typeInfo struct {
+	idx     int
+	derived bool
+}
+
+type objInfo struct {
+	idx       int        // index for the generic function declaration
+	explicits []typeInfo // info for the type arguments
+}
+
+func (info objInfo) anyDerived() bool {
+	for _, explicit := range info.explicits {
+		if explicit.derived {
+			return true
+		}
+	}
+	return false
+}
+
+func (info objInfo) equals(other objInfo) bool {
+	if info.idx != other.idx {
+		return false
+	}
+	assert(len(info.explicits) == len(other.explicits))
+	for i, targ := range info.explicits {
+		if targ != other.explicits[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func (pw *pkgWriter) newWriter(k reloc, marker syncMarker) *writer {
+	return &writer{
+		encoder: pw.newEncoder(k, marker),
+		p:       pw,
+	}
+}
+
+// @@@ Positions
+
+func (w *writer) pos(p poser) {
+	w.sync(syncPos)
+	pos := p.Pos()
+
+	// TODO(mdempsky): Track down the remaining cases here and fix them.
+	if !w.bool(pos.IsKnown()) {
+		return
+	}
+
+	// TODO(mdempsky): Delta encoding. Also, if there's a b-side, update
+	// its position base too (but not vice versa!).
+	w.posBase(pos.Base())
+	w.uint(pos.Line())
+	w.uint(pos.Col())
+}
+
+func (w *writer) posBase(b *syntax.PosBase) {
+	w.reloc(relocPosBase, w.p.posBaseIdx(b))
+}
+
+func (pw *pkgWriter) posBaseIdx(b *syntax.PosBase) int {
+	if idx, ok := pw.posBasesIdx[b]; ok {
+		return idx
+	}
+
+	w := pw.newWriter(relocPosBase, syncPosBase)
+	w.p.posBasesIdx[b] = w.idx
+
+	// TODO(mdempsky): What exactly does "fileh" do anyway? Is writing
+	// out both of these strings really the right thing to do here?
+	fn := b.Filename()
+	w.string(fn)
+	w.string(fileh(fn))
+
+	if !w.bool(b.IsFileBase()) {
+		w.pos(b)
+		w.uint(b.Line())
+		w.uint(b.Col())
+	}
+
+	return w.flush()
+}
+
+// @@@ Packages
+
+func (w *writer) pkg(pkg *types2.Package) {
+	w.sync(syncPkg)
+	w.reloc(relocPkg, w.p.pkgIdx(pkg))
+}
+
+func (pw *pkgWriter) pkgIdx(pkg *types2.Package) int {
+	if idx, ok := pw.pkgsIdx[pkg]; ok {
+		return idx
+	}
+
+	w := pw.newWriter(relocPkg, syncPkgDef)
+	pw.pkgsIdx[pkg] = w.idx
+
+	if pkg == nil {
+		w.string("builtin")
+	} else {
+		var path string
+		if pkg != w.p.curpkg {
+			path = pkg.Path()
+		}
+		w.string(path)
+		w.string(pkg.Name())
+		w.len(pkg.Height())
+
+		w.len(len(pkg.Imports()))
+		for _, imp := range pkg.Imports() {
+			w.pkg(imp)
+		}
+	}
+
+	return w.flush()
+}
+
+// @@@ Types
+
+func (w *writer) typ(typ types2.Type) {
+	w.typInfo(w.p.typIdx(typ, w.dict))
+}
+
+func (w *writer) typInfo(info typeInfo) {
+	w.sync(syncType)
+	if w.bool(info.derived) {
+		w.len(info.idx)
+		w.derived = true
+	} else {
+		w.reloc(relocType, info.idx)
+	}
+}
+
+// typIdx returns the index where the export data description of type
+// can be read back in. If no such index exists yet, it's created.
+//
+// typIdx also reports whether typ is a derived type; that is, whether
+// its identity depends on type parameters.
+func (pw *pkgWriter) typIdx(typ types2.Type, dict *writerDict) typeInfo {
+	if quirksMode() {
+		typ = pw.dups.orig(typ)
+	}
+
+	if idx, ok := pw.typsIdx[typ]; ok {
+		return typeInfo{idx: idx, derived: false}
+	}
+	if dict != nil {
+		if idx, ok := dict.derivedIdx[typ]; ok {
+			return typeInfo{idx: idx, derived: true}
+		}
+	}
+
+	w := pw.newWriter(relocType, syncTypeIdx)
+	w.dict = dict
+
+	switch typ := typ.(type) {
+	default:
+		base.Fatalf("unexpected type: %v (%T)", typ, typ)
+
+	case *types2.Basic:
+		switch kind := typ.Kind(); {
+		case kind == types2.Invalid:
+			base.Fatalf("unexpected types2.Invalid")
+
+		case types2.Typ[kind] == typ:
+			w.code(typeBasic)
+			w.len(int(kind))
+
+		default:
+			// Handle "byte" and "rune" as references to their TypeName.
+			obj := types2.Universe.Lookup(typ.Name())
+			assert(obj.Type() == typ)
+
+			w.code(typeNamed)
+			w.obj(obj, nil)
+		}
+
+	case *types2.Named:
+		// Type aliases can refer to uninstantiated generic types, so we
+		// might see len(TParams) != 0 && len(TArgs) == 0 here.
+		// TODO(mdempsky): Revisit after #46477 is resolved.
+		assert(typ.TParams().Len() == len(typ.TArgs()) || len(typ.TArgs()) == 0)
+
+		// TODO(mdempsky): Why do we need to loop here?
+		orig := typ
+		for orig.TArgs() != nil {
+			orig = orig.Orig()
+		}
+
+		w.code(typeNamed)
+		w.obj(orig.Obj(), typ.TArgs())
+
+	case *types2.TypeParam:
+		index := func() int {
+			for idx, name := range w.dict.implicits {
+				if name.Type().(*types2.TypeParam) == typ {
+					return idx
+				}
+			}
+
+			return len(w.dict.implicits) + typ.Index()
+		}()
+
+		w.derived = true
+		w.code(typeTypeParam)
+		w.len(index)
+
+	case *types2.Array:
+		w.code(typeArray)
+		w.uint64(uint64(typ.Len()))
+		w.typ(typ.Elem())
+
+	case *types2.Chan:
+		w.code(typeChan)
+		w.len(int(typ.Dir()))
+		w.typ(typ.Elem())
+
+	case *types2.Map:
+		w.code(typeMap)
+		w.typ(typ.Key())
+		w.typ(typ.Elem())
+
+	case *types2.Pointer:
+		w.code(typePointer)
+		w.typ(typ.Elem())
+
+	case *types2.Signature:
+		assert(typ.TParams() == nil)
+		w.code(typeSignature)
+		w.signature(typ)
+
+	case *types2.Slice:
+		w.code(typeSlice)
+		w.typ(typ.Elem())
+
+	case *types2.Struct:
+		w.code(typeStruct)
+		w.structType(typ)
+
+	case *types2.Interface:
+		w.code(typeInterface)
+		w.interfaceType(typ)
+
+	case *types2.Union:
+		w.code(typeUnion)
+		w.unionType(typ)
+	}
+
+	if w.derived {
+		idx := len(dict.derived)
+		dict.derived = append(dict.derived, derivedInfo{idx: w.flush()})
+		dict.derivedIdx[typ] = idx
+		return typeInfo{idx: idx, derived: true}
+	}
+
+	pw.typsIdx[typ] = w.idx
+	return typeInfo{idx: w.flush(), derived: false}
+}
+
+func (w *writer) structType(typ *types2.Struct) {
+	w.len(typ.NumFields())
+	for i := 0; i < typ.NumFields(); i++ {
+		f := typ.Field(i)
+		w.pos(f)
+		w.selector(f)
+		w.typ(f.Type())
+		w.string(typ.Tag(i))
+		w.bool(f.Embedded())
+	}
+}
+
+func (w *writer) unionType(typ *types2.Union) {
+	w.len(typ.Len())
+	for i := 0; i < typ.Len(); i++ {
+		t := typ.Term(i)
+		w.bool(t.Tilde())
+		w.typ(t.Type())
+	}
+}
+
+func (w *writer) interfaceType(typ *types2.Interface) {
+	w.len(typ.NumExplicitMethods())
+	w.len(typ.NumEmbeddeds())
+
+	for i := 0; i < typ.NumExplicitMethods(); i++ {
+		m := typ.ExplicitMethod(i)
+		sig := m.Type().(*types2.Signature)
+		assert(sig.TParams() == nil)
+
+		w.pos(m)
+		w.selector(m)
+		w.signature(sig)
+	}
+
+	for i := 0; i < typ.NumEmbeddeds(); i++ {
+		w.typ(typ.EmbeddedType(i))
+	}
+}
+
+func (w *writer) signature(sig *types2.Signature) {
+	w.sync(syncSignature)
+	w.params(sig.Params())
+	w.params(sig.Results())
+	w.bool(sig.Variadic())
+}
+
+func (w *writer) params(typ *types2.Tuple) {
+	w.sync(syncParams)
+	w.len(typ.Len())
+	for i := 0; i < typ.Len(); i++ {
+		w.param(typ.At(i))
+	}
+}
+
+func (w *writer) param(param *types2.Var) {
+	w.sync(syncParam)
+	w.pos(param)
+	w.localIdent(param)
+	w.typ(param.Type())
+}
+
+// @@@ Objects
+
+func (w *writer) obj(obj types2.Object, explicits []types2.Type) {
+	explicitInfos := make([]typeInfo, len(explicits))
+	for i, explicit := range explicits {
+		explicitInfos[i] = w.p.typIdx(explicit, w.dict)
+	}
+	info := objInfo{idx: w.p.objIdx(obj), explicits: explicitInfos}
+
+	if _, ok := obj.(*types2.Func); ok && info.anyDerived() {
+		idx := -1
+		for i, prev := range w.dict.funcs {
+			if prev.equals(info) {
+				idx = i
+			}
+		}
+		if idx < 0 {
+			idx = len(w.dict.funcs)
+			w.dict.funcs = append(w.dict.funcs, info)
+		}
+
+		// TODO(mdempsky): Push up into expr; this shouldn't appear
+		// outside of expression context.
+		w.sync(syncObject)
+		w.bool(true)
+		w.len(idx)
+		return
+	}
+
+	// TODO(mdempsky): Push up into typIdx; this shouldn't be needed
+	// except while writing out types.
+	if isDefinedType(obj) && obj.Pkg() == w.p.curpkg {
+		decl, ok := w.p.typDecls[obj.(*types2.TypeName)]
+		assert(ok)
+		if len(decl.implicits) != 0 {
+			w.derived = true
+		}
+	}
+
+	w.sync(syncObject)
+	w.bool(false)
+	w.reloc(relocObj, info.idx)
+
+	w.len(len(info.explicits))
+	for _, info := range info.explicits {
+		w.typInfo(info)
+	}
+}
+
+func (pw *pkgWriter) objIdx(obj types2.Object) int {
+	if idx, ok := pw.globalsIdx[obj]; ok {
+		return idx
+	}
+
+	dict := &writerDict{
+		derivedIdx: make(map[types2.Type]int),
+	}
+
+	if isDefinedType(obj) && obj.Pkg() == pw.curpkg {
+		decl, ok := pw.typDecls[obj.(*types2.TypeName)]
+		assert(ok)
+		dict.implicits = decl.implicits
+	}
+
+	w := pw.newWriter(relocObj, syncObject1)
+	w.ext = pw.newWriter(relocObjExt, syncObject1)
+	wname := pw.newWriter(relocName, syncObject1)
+	wdict := pw.newWriter(relocObjDict, syncObject1)
+
+	pw.globalsIdx[obj] = w.idx // break cycles
+	assert(w.ext.idx == w.idx)
+	assert(wname.idx == w.idx)
+	assert(wdict.idx == w.idx)
+
+	w.dict = dict
+	w.ext.dict = dict
+
+	code := w.doObj(obj)
+	w.flush()
+	w.ext.flush()
+
+	wname.qualifiedIdent(obj)
+	wname.code(code)
+	wname.flush()
+
+	wdict.objDict(obj, w.dict)
+	wdict.flush()
+
+	return w.idx
+}
+
+func (w *writer) doObj(obj types2.Object) codeObj {
+	if obj.Pkg() != w.p.curpkg {
+		return objStub
+	}
+
+	switch obj := obj.(type) {
+	default:
+		w.p.unexpected("object", obj)
+		panic("unreachable")
+
+	case *types2.Const:
+		w.pos(obj)
+		w.value(obj.Type(), obj.Val())
+		return objConst
+
+	case *types2.Func:
+		decl, ok := w.p.funDecls[obj]
+		assert(ok)
+		sig := obj.Type().(*types2.Signature)
+
+		w.pos(obj)
+		w.typeParamNames(sig.TParams())
+		w.signature(sig)
+		w.pos(decl)
+		w.ext.funcExt(obj)
+		return objFunc
+
+	case *types2.TypeName:
+		decl, ok := w.p.typDecls[obj]
+		assert(ok)
+
+		if obj.IsAlias() {
+			w.pos(obj)
+			w.typ(obj.Type())
+			return objAlias
+		}
+
+		named := obj.Type().(*types2.Named)
+		assert(named.TArgs() == nil)
+
+		w.pos(obj)
+		w.typeParamNames(named.TParams())
+		w.ext.typeExt(obj)
+		w.typExpr(decl.Type)
+
+		w.len(named.NumMethods())
+		for i := 0; i < named.NumMethods(); i++ {
+			w.method(named.Method(i))
+		}
+
+		return objType
+
+	case *types2.Var:
+		w.pos(obj)
+		w.typ(obj.Type())
+		w.ext.varExt(obj)
+		return objVar
+	}
+}
+
+// typExpr writes the type represented by the given expression.
+func (w *writer) typExpr(expr syntax.Expr) {
+	tv, ok := w.p.info.Types[expr]
+	assert(ok)
+	assert(tv.IsType())
+	w.typ(tv.Type)
+}
+
+func (w *writer) value(typ types2.Type, val constant.Value) {
+	w.sync(syncValue)
+	w.typ(typ)
+	w.rawValue(val)
+}
+
+// objDict writes the dictionary needed for reading the given object.
+func (w *writer) objDict(obj types2.Object, dict *writerDict) {
+	// TODO(mdempsky): Split objDict into multiple entries? reader.go
+	// doesn't care about the type parameter bounds, and reader2.go
+	// doesn't care about referenced functions.
+
+	w.dict = dict // TODO(mdempsky): This is a bit sketchy.
+
+	w.len(len(dict.implicits))
+
+	tparams := objTypeParams(obj)
+	ntparams := tparams.Len()
+	w.len(ntparams)
+	for i := 0; i < ntparams; i++ {
+		w.typ(tparams.At(i).Type().(*types2.TypeParam).Constraint())
+	}
+
+	nderived := len(dict.derived)
+	w.len(nderived)
+	for _, typ := range dict.derived {
+		w.reloc(relocType, typ.idx)
+		w.bool(typ.needed)
+	}
+
+	nfuncs := len(dict.funcs)
+	w.len(nfuncs)
+	for _, fn := range dict.funcs {
+		w.reloc(relocObj, fn.idx)
+		w.len(len(fn.explicits))
+		for _, targ := range fn.explicits {
+			w.typInfo(targ)
+		}
+	}
+
+	assert(len(dict.derived) == nderived)
+	assert(len(dict.funcs) == nfuncs)
+}
+
+func (w *writer) typeParamNames(tparams *types2.TParamList) {
+	w.sync(syncTypeParamNames)
+
+	ntparams := tparams.Len()
+	for i := 0; i < ntparams; i++ {
+		tparam := tparams.At(i)
+		w.pos(tparam)
+		w.localIdent(tparam)
+	}
+}
+
+func (w *writer) method(meth *types2.Func) {
+	decl, ok := w.p.funDecls[meth]
+	assert(ok)
+	sig := meth.Type().(*types2.Signature)
+
+	w.sync(syncMethod)
+	w.pos(meth)
+	w.selector(meth)
+	w.typeParamNames(sig.RParams())
+	w.param(sig.Recv())
+	w.signature(sig)
+
+	w.pos(decl) // XXX: Hack to workaround linker limitations.
+	w.ext.funcExt(meth)
+}
+
+// qualifiedIdent writes out the name of an object declared at package
+// scope. (For now, it's also used to refer to local defined types.)
+func (w *writer) qualifiedIdent(obj types2.Object) {
+	w.sync(syncSym)
+
+	name := obj.Name()
+	if isDefinedType(obj) && obj.Pkg() == w.p.curpkg {
+		decl, ok := w.p.typDecls[obj.(*types2.TypeName)]
+		assert(ok)
+		if decl.gen != 0 {
+			// TODO(mdempsky): Find a better solution than embedding middle
+			// dot in the symbol name; this is terrible.
+			name = fmt.Sprintf("%s·%v", name, decl.gen)
+		}
+	}
+
+	w.pkg(obj.Pkg())
+	w.string(name)
+}
+
+// TODO(mdempsky): We should be able to omit pkg from both localIdent
+// and selector, because they should always be known from context.
+// However, past frustrations with this optimization in iexport make
+// me a little nervous to try it again.
+
+// localIdent writes the name of a locally declared object (i.e.,
+// objects that can only be accessed by name, within the context of a
+// particular function).
+func (w *writer) localIdent(obj types2.Object) {
+	assert(!isGlobal(obj))
+	w.sync(syncLocalIdent)
+	w.pkg(obj.Pkg())
+	w.string(obj.Name())
+}
+
+// selector writes the name of a field or method (i.e., objects that
+// can only be accessed using selector expressions).
+func (w *writer) selector(obj types2.Object) {
+	w.sync(syncSelector)
+	w.pkg(obj.Pkg())
+	w.string(obj.Name())
+}
+
+// @@@ Compiler extensions
+
+func (w *writer) funcExt(obj *types2.Func) {
+	decl, ok := w.p.funDecls[obj]
+	assert(ok)
+
+	// TODO(mdempsky): Extend these pragma validation flags to account
+	// for generics. E.g., linkname probably doesn't make sense at
+	// least.
+
+	pragma := asPragmaFlag(decl.Pragma)
+	if pragma&ir.Systemstack != 0 && pragma&ir.Nosplit != 0 {
+		w.p.errorf(decl, "go:nosplit and go:systemstack cannot be combined")
+	}
+
+	if decl.Body != nil {
+		if pragma&ir.Noescape != 0 {
+			w.p.errorf(decl, "can only use //go:noescape with external func implementations")
+		}
+	} else {
+		if base.Flag.Complete || decl.Name.Value == "init" {
+			// Linknamed functions are allowed to have no body. Hopefully
+			// the linkname target has a body. See issue 23311.
+			if _, ok := w.p.linknames[obj]; !ok {
+				w.p.errorf(decl, "missing function body")
+			}
+		}
+	}
+
+	sig, block := obj.Type().(*types2.Signature), decl.Body
+	body, closureVars := w.p.bodyIdx(w.p.curpkg, sig, block, w.dict)
+	assert(len(closureVars) == 0)
+
+	w.sync(syncFuncExt)
+	w.pragmaFlag(pragma)
+	w.linkname(obj)
+	w.bool(false) // stub extension
+	w.reloc(relocBody, body)
+	w.sync(syncEOF)
+}
+
+func (w *writer) typeExt(obj *types2.TypeName) {
+	decl, ok := w.p.typDecls[obj]
+	assert(ok)
+
+	w.sync(syncTypeExt)
+
+	w.pragmaFlag(asPragmaFlag(decl.Pragma))
+
+	// No LSym.SymIdx info yet.
+	w.int64(-1)
+	w.int64(-1)
+}
+
+func (w *writer) varExt(obj *types2.Var) {
+	w.sync(syncVarExt)
+	w.linkname(obj)
+}
+
+func (w *writer) linkname(obj types2.Object) {
+	w.sync(syncLinkname)
+	w.int64(-1)
+	w.string(w.p.linknames[obj])
+}
+
+func (w *writer) pragmaFlag(p ir.PragmaFlag) {
+	w.sync(syncPragma)
+	w.int(int(p))
+}
+
+// @@@ Function bodies
+
+func (pw *pkgWriter) bodyIdx(pkg *types2.Package, sig *types2.Signature, block *syntax.BlockStmt, dict *writerDict) (idx int, closureVars []posObj) {
+	w := pw.newWriter(relocBody, syncFuncBody)
+	w.dict = dict
+
+	w.funcargs(sig)
+	if w.bool(block != nil) {
+		w.stmts(block.List)
+		w.pos(block.Rbrace)
+	}
+
+	return w.flush(), w.closureVars
+}
+
+func (w *writer) funcargs(sig *types2.Signature) {
+	do := func(params *types2.Tuple, result bool) {
+		for i := 0; i < params.Len(); i++ {
+			w.funcarg(params.At(i), result)
+		}
+	}
+
+	if recv := sig.Recv(); recv != nil {
+		w.funcarg(recv, false)
+	}
+	do(sig.Params(), false)
+	do(sig.Results(), true)
+}
+
+func (w *writer) funcarg(param *types2.Var, result bool) {
+	if param.Name() != "" || result {
+		w.addLocal(param)
+	}
+}
+
+func (w *writer) addLocal(obj *types2.Var) {
+	w.sync(syncAddLocal)
+	idx := len(w.localsIdx)
+	if enableSync {
+		w.int(idx)
+	}
+	if w.localsIdx == nil {
+		w.localsIdx = make(map[*types2.Var]int)
+	}
+	w.localsIdx[obj] = idx
+}
+
+func (w *writer) useLocal(pos syntax.Pos, obj *types2.Var) {
+	w.sync(syncUseObjLocal)
+
+	if idx, ok := w.localsIdx[obj]; w.bool(ok) {
+		w.len(idx)
+		return
+	}
+
+	idx, ok := w.closureVarsIdx[obj]
+	if !ok {
+		if w.closureVarsIdx == nil {
+			w.closureVarsIdx = make(map[*types2.Var]int)
+		}
+		idx = len(w.closureVars)
+		w.closureVars = append(w.closureVars, posObj{pos, obj})
+		w.closureVarsIdx[obj] = idx
+	}
+	w.len(idx)
+}
+
+func (w *writer) openScope(pos syntax.Pos) {
+	w.sync(syncOpenScope)
+	w.pos(pos)
+}
+
+func (w *writer) closeScope(pos syntax.Pos) {
+	w.sync(syncCloseScope)
+	w.pos(pos)
+	w.closeAnotherScope()
+}
+
+func (w *writer) closeAnotherScope() {
+	w.sync(syncCloseAnotherScope)
+}
+
+// @@@ Statements
+
+func (w *writer) stmt(stmt syntax.Stmt) {
+	var stmts []syntax.Stmt
+	if stmt != nil {
+		stmts = []syntax.Stmt{stmt}
+	}
+	w.stmts(stmts)
+}
+
+func (w *writer) stmts(stmts []syntax.Stmt) {
+	w.sync(syncStmts)
+	for _, stmt := range stmts {
+		w.stmt1(stmt)
+	}
+	w.code(stmtEnd)
+	w.sync(syncStmtsEnd)
+}
+
+func (w *writer) stmt1(stmt syntax.Stmt) {
+	switch stmt := stmt.(type) {
+	default:
+		w.p.unexpected("statement", stmt)
+
+	case nil, *syntax.EmptyStmt:
+		return
+
+	case *syntax.AssignStmt:
+		switch {
+		case stmt.Rhs == nil:
+			w.code(stmtIncDec)
+			w.op(binOps[stmt.Op])
+			w.expr(stmt.Lhs)
+			w.pos(stmt)
+
+		case stmt.Op != 0 && stmt.Op != syntax.Def:
+			w.code(stmtAssignOp)
+			w.op(binOps[stmt.Op])
+			w.expr(stmt.Lhs)
+			w.pos(stmt)
+			w.expr(stmt.Rhs)
+
+		default:
+			w.code(stmtAssign)
+			w.pos(stmt)
+			w.exprList(stmt.Rhs)
+			w.assignList(stmt.Lhs)
+		}
+
+	case *syntax.BlockStmt:
+		w.code(stmtBlock)
+		w.blockStmt(stmt)
+
+	case *syntax.BranchStmt:
+		w.code(stmtBranch)
+		w.pos(stmt)
+		w.op(branchOps[stmt.Tok])
+		w.optLabel(stmt.Label)
+
+	case *syntax.CallStmt:
+		w.code(stmtCall)
+		w.pos(stmt)
+		w.op(callOps[stmt.Tok])
+		w.expr(stmt.Call)
+
+	case *syntax.DeclStmt:
+		for _, decl := range stmt.DeclList {
+			w.declStmt(decl)
+		}
+
+	case *syntax.ExprStmt:
+		w.code(stmtExpr)
+		w.expr(stmt.X)
+
+	case *syntax.ForStmt:
+		w.code(stmtFor)
+		w.forStmt(stmt)
+
+	case *syntax.IfStmt:
+		w.code(stmtIf)
+		w.ifStmt(stmt)
+
+	case *syntax.LabeledStmt:
+		w.code(stmtLabel)
+		w.pos(stmt)
+		w.label(stmt.Label)
+		w.stmt1(stmt.Stmt)
+
+	case *syntax.ReturnStmt:
+		w.code(stmtReturn)
+		w.pos(stmt)
+		w.exprList(stmt.Results)
+
+	case *syntax.SelectStmt:
+		w.code(stmtSelect)
+		w.selectStmt(stmt)
+
+	case *syntax.SendStmt:
+		w.code(stmtSend)
+		w.pos(stmt)
+		w.expr(stmt.Chan)
+		w.expr(stmt.Value)
+
+	case *syntax.SwitchStmt:
+		w.code(stmtSwitch)
+		w.switchStmt(stmt)
+	}
+}
+
+func (w *writer) assignList(expr syntax.Expr) {
+	exprs := unpackListExpr(expr)
+	w.len(len(exprs))
+
+	for _, expr := range exprs {
+		if name, ok := expr.(*syntax.Name); ok && name.Value != "_" {
+			if obj, ok := w.p.info.Defs[name]; ok {
+				obj := obj.(*types2.Var)
+
+				w.bool(true)
+				w.pos(obj)
+				w.localIdent(obj)
+				w.typ(obj.Type())
+
+				// TODO(mdempsky): Minimize locals index size by deferring
+				// this until the variables actually come into scope.
+				w.addLocal(obj)
+				continue
+			}
+		}
+
+		w.bool(false)
+		w.expr(expr)
+	}
+}
+
+func (w *writer) declStmt(decl syntax.Decl) {
+	switch decl := decl.(type) {
+	default:
+		w.p.unexpected("declaration", decl)
+
+	case *syntax.ConstDecl:
+
+	case *syntax.TypeDecl:
+		// Quirk: The legacy inliner doesn't support inlining functions
+		// with type declarations. Unified IR doesn't have any need to
+		// write out type declarations explicitly (they're always looked
+		// up via global index tables instead), so we just write out a
+		// marker so the reader knows to synthesize a fake declaration to
+		// prevent inlining.
+		if quirksMode() {
+			w.code(stmtTypeDeclHack)
+		}
+
+	case *syntax.VarDecl:
+		values := unpackListExpr(decl.Values)
+
+		// Quirk: When N variables are declared with N initialization
+		// values, we need to decompose that into N interleaved
+		// declarations+initializations, because it leads to different
+		// (albeit semantically equivalent) code generation.
+		if quirksMode() && len(decl.NameList) == len(values) {
+			for i, name := range decl.NameList {
+				w.code(stmtAssign)
+				w.pos(decl)
+				w.exprList(values[i])
+				w.assignList(name)
+			}
+			break
+		}
+
+		w.code(stmtAssign)
+		w.pos(decl)
+		w.exprList(decl.Values)
+		w.assignList(namesAsExpr(decl.NameList))
+	}
+}
+
+func (w *writer) blockStmt(stmt *syntax.BlockStmt) {
+	w.sync(syncBlockStmt)
+	w.openScope(stmt.Pos())
+	w.stmts(stmt.List)
+	w.closeScope(stmt.Rbrace)
+}
+
+func (w *writer) forStmt(stmt *syntax.ForStmt) {
+	w.sync(syncForStmt)
+	w.openScope(stmt.Pos())
+
+	if rang, ok := stmt.Init.(*syntax.RangeClause); w.bool(ok) {
+		w.pos(rang)
+		w.expr(rang.X)
+		w.assignList(rang.Lhs)
+	} else {
+		w.pos(stmt)
+		w.stmt(stmt.Init)
+		w.expr(stmt.Cond)
+		w.stmt(stmt.Post)
+	}
+
+	w.blockStmt(stmt.Body)
+	w.closeAnotherScope()
+}
+
+func (w *writer) ifStmt(stmt *syntax.IfStmt) {
+	w.sync(syncIfStmt)
+	w.openScope(stmt.Pos())
+	w.pos(stmt)
+	w.stmt(stmt.Init)
+	w.expr(stmt.Cond)
+	w.blockStmt(stmt.Then)
+	w.stmt(stmt.Else)
+	w.closeAnotherScope()
+}
+
+func (w *writer) selectStmt(stmt *syntax.SelectStmt) {
+	w.sync(syncSelectStmt)
+
+	w.pos(stmt)
+	w.len(len(stmt.Body))
+	for i, clause := range stmt.Body {
+		if i > 0 {
+			w.closeScope(clause.Pos())
+		}
+		w.openScope(clause.Pos())
+
+		w.pos(clause)
+		w.stmt(clause.Comm)
+		w.stmts(clause.Body)
+	}
+	if len(stmt.Body) > 0 {
+		w.closeScope(stmt.Rbrace)
+	}
+}
+
+func (w *writer) switchStmt(stmt *syntax.SwitchStmt) {
+	w.sync(syncSwitchStmt)
+
+	w.openScope(stmt.Pos())
+	w.pos(stmt)
+	w.stmt(stmt.Init)
+
+	if guard, ok := stmt.Tag.(*syntax.TypeSwitchGuard); w.bool(ok) {
+		w.pos(guard)
+		if tag := guard.Lhs; w.bool(tag != nil) {
+			w.pos(tag)
+			w.string(tag.Value)
+		}
+		w.expr(guard.X)
+	} else {
+		w.expr(stmt.Tag)
+	}
+
+	w.len(len(stmt.Body))
+	for i, clause := range stmt.Body {
+		if i > 0 {
+			w.closeScope(clause.Pos())
+		}
+		w.openScope(clause.Pos())
+
+		w.pos(clause)
+		w.exprList(clause.Cases)
+
+		if obj, ok := w.p.info.Implicits[clause]; ok {
+			// TODO(mdempsky): These pos details are quirkish, but also
+			// necessary so the variable's position is correct for DWARF
+			// scope assignment later. It would probably be better for us to
+			// instead just set the variable's DWARF scoping info earlier so
+			// we can give it the correct position information.
+			pos := clause.Pos()
+			if typs := unpackListExpr(clause.Cases); len(typs) != 0 {
+				pos = typeExprEndPos(typs[len(typs)-1])
+			}
+			w.pos(pos)
+
+			obj := obj.(*types2.Var)
+			w.typ(obj.Type())
+			w.addLocal(obj)
+		}
+
+		w.stmts(clause.Body)
+	}
+	if len(stmt.Body) > 0 {
+		w.closeScope(stmt.Rbrace)
+	}
+
+	w.closeScope(stmt.Rbrace)
+}
+
+func (w *writer) label(label *syntax.Name) {
+	w.sync(syncLabel)
+
+	// TODO(mdempsky): Replace label strings with dense indices.
+	w.string(label.Value)
+}
+
+func (w *writer) optLabel(label *syntax.Name) {
+	w.sync(syncOptLabel)
+	if w.bool(label != nil) {
+		w.label(label)
+	}
+}
+
+// @@@ Expressions
+
+func (w *writer) expr(expr syntax.Expr) {
+	expr = unparen(expr) // skip parens; unneeded after typecheck
+
+	obj, targs := lookupObj(w.p.info, expr)
+
+	if tv, ok := w.p.info.Types[expr]; ok {
+		// TODO(mdempsky): Be more judicious about which types are marked as "needed".
+		w.needType(tv.Type)
+
+		if tv.IsType() {
+			w.code(exprType)
+			w.typ(tv.Type)
+			return
+		}
+
+		if tv.Value != nil {
+			pos := expr.Pos()
+			if quirksMode() {
+				if obj != nil {
+					// Quirk: IR (and thus iexport) doesn't track position
+					// information for uses of declared objects.
+					pos = syntax.Pos{}
+				} else if tv.Value.Kind() == constant.String {
+					// Quirk: noder.sum picks a particular position for certain
+					// string concatenations.
+					pos = sumPos(expr)
+				}
+			}
+
+			w.code(exprConst)
+			w.pos(pos)
+			w.value(tv.Type, tv.Value)
+
+			// TODO(mdempsky): These details are only important for backend
+			// diagnostics. Explore writing them out separately.
+			w.op(constExprOp(expr))
+			w.string(syntax.String(expr))
+			return
+		}
+	}
+
+	if obj != nil {
+		if isGlobal(obj) {
+			w.code(exprName)
+			w.obj(obj, targs)
+			return
+		}
+
+		obj := obj.(*types2.Var)
+		assert(len(targs) == 0)
+
+		w.code(exprLocal)
+		w.useLocal(expr.Pos(), obj)
+		return
+	}
+
+	switch expr := expr.(type) {
+	default:
+		w.p.unexpected("expression", expr)
+
+	case nil: // absent slice index, for condition, or switch tag
+		w.code(exprNone)
+
+	case *syntax.Name:
+		assert(expr.Value == "_")
+		w.code(exprBlank)
+
+	case *syntax.CompositeLit:
+		w.code(exprCompLit)
+		w.compLit(expr)
+
+	case *syntax.FuncLit:
+		w.code(exprFuncLit)
+		w.funcLit(expr)
+
+	case *syntax.SelectorExpr:
+		sel, ok := w.p.info.Selections[expr]
+		assert(ok)
+
+		w.code(exprSelector)
+		w.expr(expr.X)
+		w.pos(expr)
+		w.selector(sel.Obj())
+
+	case *syntax.IndexExpr:
+		tv, ok := w.p.info.Types[expr.Index]
+		assert(ok && tv.IsValue())
+
+		w.code(exprIndex)
+		w.expr(expr.X)
+		w.pos(expr)
+		w.expr(expr.Index)
+
+	case *syntax.SliceExpr:
+		w.code(exprSlice)
+		w.expr(expr.X)
+		w.pos(expr)
+		for _, n := range &expr.Index {
+			w.expr(n)
+		}
+
+	case *syntax.AssertExpr:
+		w.code(exprAssert)
+		w.expr(expr.X)
+		w.pos(expr)
+		w.expr(expr.Type)
+
+	case *syntax.Operation:
+		if expr.Y == nil {
+			w.code(exprUnaryOp)
+			w.op(unOps[expr.Op])
+			w.pos(expr)
+			w.expr(expr.X)
+			break
+		}
+
+		w.code(exprBinaryOp)
+		w.op(binOps[expr.Op])
+		w.expr(expr.X)
+		w.pos(expr)
+		w.expr(expr.Y)
+
+	case *syntax.CallExpr:
+		tv, ok := w.p.info.Types[expr.Fun]
+		assert(ok)
+		if tv.IsType() {
+			assert(len(expr.ArgList) == 1)
+			assert(!expr.HasDots)
+
+			w.code(exprConvert)
+			w.typ(tv.Type)
+			w.pos(expr)
+			w.expr(expr.ArgList[0])
+			break
+		}
+
+		writeFunExpr := func() {
+			if selector, ok := unparen(expr.Fun).(*syntax.SelectorExpr); ok {
+				if sel, ok := w.p.info.Selections[selector]; ok && sel.Kind() == types2.MethodVal {
+					w.expr(selector.X)
+					w.bool(true) // method call
+					w.pos(selector)
+					w.selector(sel.Obj())
+					return
+				}
+			}
+
+			if inf, ok := w.p.info.Inferred[expr]; ok {
+				obj, _ := lookupObj(w.p.info, expr.Fun)
+				assert(obj != nil)
+
+				// As if w.expr(expr.Fun), but using inf.TArgs instead.
+				w.code(exprName)
+				w.obj(obj, inf.TArgs)
+			} else {
+				w.expr(expr.Fun)
+			}
+			w.bool(false) // not a method call (i.e., normal function call)
+		}
+
+		w.code(exprCall)
+		writeFunExpr()
+		w.pos(expr)
+		w.exprs(expr.ArgList)
+		w.bool(expr.HasDots)
+	}
+}
+
+func (w *writer) compLit(lit *syntax.CompositeLit) {
+	tv, ok := w.p.info.Types[lit]
+	assert(ok)
+
+	w.sync(syncCompLit)
+	w.pos(lit)
+	w.typ(tv.Type)
+
+	typ := tv.Type
+	if ptr, ok := typ.Underlying().(*types2.Pointer); ok {
+		typ = ptr.Elem()
+	}
+	str, isStruct := typ.Underlying().(*types2.Struct)
+
+	w.len(len(lit.ElemList))
+	for i, elem := range lit.ElemList {
+		if isStruct {
+			if kv, ok := elem.(*syntax.KeyValueExpr); ok {
+				// use position of expr.Key rather than of elem (which has position of ':')
+				w.pos(kv.Key)
+				w.len(fieldIndex(w.p.info, str, kv.Key.(*syntax.Name)))
+				elem = kv.Value
+			} else {
+				w.pos(elem)
+				w.len(i)
+			}
+		} else {
+			if kv, ok := elem.(*syntax.KeyValueExpr); w.bool(ok) {
+				// use position of expr.Key rather than of elem (which has position of ':')
+				w.pos(kv.Key)
+				w.expr(kv.Key)
+				elem = kv.Value
+			}
+		}
+		w.pos(elem)
+		w.expr(elem)
+	}
+}
+
+func (w *writer) funcLit(expr *syntax.FuncLit) {
+	tv, ok := w.p.info.Types[expr]
+	assert(ok)
+	sig := tv.Type.(*types2.Signature)
+
+	body, closureVars := w.p.bodyIdx(w.p.curpkg, sig, expr.Body, w.dict)
+
+	w.sync(syncFuncLit)
+	w.pos(expr)
+	w.pos(expr.Type) // for QuirksMode
+	w.signature(sig)
+
+	w.len(len(closureVars))
+	for _, cv := range closureVars {
+		w.pos(cv.pos)
+		if quirksMode() {
+			cv.pos = expr.Body.Rbrace
+		}
+		w.useLocal(cv.pos, cv.obj)
+	}
+
+	w.reloc(relocBody, body)
+}
+
+type posObj struct {
+	pos syntax.Pos
+	obj *types2.Var
+}
+
+func (w *writer) exprList(expr syntax.Expr) {
+	w.sync(syncExprList)
+	w.exprs(unpackListExpr(expr))
+}
+
+func (w *writer) exprs(exprs []syntax.Expr) {
+	if len(exprs) == 0 {
+		assert(exprs == nil)
+	}
+
+	w.sync(syncExprs)
+	w.len(len(exprs))
+	for _, expr := range exprs {
+		w.expr(expr)
+	}
+}
+
+func (w *writer) op(op ir.Op) {
+	// TODO(mdempsky): Remove in favor of explicit codes? Would make
+	// export data more stable against internal refactorings, but low
+	// priority at the moment.
+	assert(op != 0)
+	w.sync(syncOp)
+	w.len(int(op))
+}
+
+func (w *writer) needType(typ types2.Type) {
+	// Decompose tuple into component element types.
+	if typ, ok := typ.(*types2.Tuple); ok {
+		for i := 0; i < typ.Len(); i++ {
+			w.needType(typ.At(i).Type())
+		}
+		return
+	}
+
+	if info := w.p.typIdx(typ, w.dict); info.derived {
+		w.dict.derived[info.idx].needed = true
+	}
+}
+
+// @@@ Package initialization
+
+// Caution: This code is still clumsy, because toolstash -cmp is
+// particularly sensitive to it.
+
+type typeDeclGen struct {
+	*syntax.TypeDecl
+	gen int
+
+	// Implicit type parameters in scope at this type declaration.
+	implicits []*types2.TypeName
+}
+
+type fileImports struct {
+	importedEmbed, importedUnsafe bool
+}
+
+type declCollector struct {
+	pw         *pkgWriter
+	typegen    *int
+	file       *fileImports
+	withinFunc bool
+	implicits  []*types2.TypeName
+}
+
+func (c *declCollector) withTParams(obj types2.Object) *declCollector {
+	tparams := objTypeParams(obj)
+	n := tparams.Len()
+	if n == 0 {
+		return c
+	}
+
+	copy := *c
+	copy.implicits = copy.implicits[:len(copy.implicits):len(copy.implicits)]
+	for i := 0; i < n; i++ {
+		copy.implicits = append(copy.implicits, tparams.At(i))
+	}
+	return ©
+}
+
+func (c *declCollector) Visit(n syntax.Node) syntax.Visitor {
+	pw := c.pw
+
+	switch n := n.(type) {
+	case *syntax.File:
+		pw.checkPragmas(n.Pragma, ir.GoBuildPragma, false)
+
+	case *syntax.ImportDecl:
+		pw.checkPragmas(n.Pragma, 0, false)
+
+		switch pkgNameOf(pw.info, n).Imported().Path() {
+		case "embed":
+			c.file.importedEmbed = true
+		case "unsafe":
+			c.file.importedUnsafe = true
+		}
+
+	case *syntax.ConstDecl:
+		pw.checkPragmas(n.Pragma, 0, false)
+
+	case *syntax.FuncDecl:
+		pw.checkPragmas(n.Pragma, funcPragmas, false)
+
+		obj := pw.info.Defs[n.Name].(*types2.Func)
+		pw.funDecls[obj] = n
+
+		return c.withTParams(obj)
+
+	case *syntax.TypeDecl:
+		obj := pw.info.Defs[n.Name].(*types2.TypeName)
+		d := typeDeclGen{TypeDecl: n, implicits: c.implicits}
+
+		if n.Alias {
+			pw.checkPragmas(n.Pragma, 0, false)
+		} else {
+			pw.checkPragmas(n.Pragma, typePragmas, false)
+
+			// Assign a unique ID to function-scoped defined types.
+			if c.withinFunc {
+				*c.typegen++
+				d.gen = *c.typegen
+			}
+		}
+
+		pw.typDecls[obj] = d
+
+		// TODO(mdempsky): Omit? Not strictly necessary; only matters for
+		// type declarations within function literals within parameterized
+		// type declarations, but types2 the function literals will be
+		// constant folded away.
+		return c.withTParams(obj)
+
+	case *syntax.VarDecl:
+		pw.checkPragmas(n.Pragma, 0, true)
+
+		if p, ok := n.Pragma.(*pragmas); ok && len(p.Embeds) > 0 {
+			if err := checkEmbed(n, c.file.importedEmbed, c.withinFunc); err != nil {
+				pw.errorf(p.Embeds[0].Pos, "%s", err)
+			}
+		}
+
+		// Workaround for #46208. For variable declarations that
+		// declare multiple variables and have an explicit type
+		// expression, the type expression is evaluated multiple
+		// times. This affects toolstash -cmp, because iexport is
+		// sensitive to *types.Type pointer identity.
+		if quirksMode() && n.Type != nil {
+			tv, ok := pw.info.Types[n.Type]
+			assert(ok)
+			assert(tv.IsType())
+			for _, name := range n.NameList {
+				obj := pw.info.Defs[name].(*types2.Var)
+				pw.dups.add(obj.Type(), tv.Type)
+			}
+		}
+
+	case *syntax.BlockStmt:
+		if !c.withinFunc {
+			copy := *c
+			copy.withinFunc = true
+			return ©
+		}
+	}
+
+	return c
+}
+
+func (pw *pkgWriter) collectDecls(noders []*noder) {
+	var typegen int
+	for _, p := range noders {
+		var file fileImports
+
+		syntax.Walk(p.file, &declCollector{
+			pw:      pw,
+			typegen: &typegen,
+			file:    &file,
+		})
+
+		pw.cgoPragmas = append(pw.cgoPragmas, p.pragcgobuf...)
+
+		for _, l := range p.linknames {
+			if !file.importedUnsafe {
+				pw.errorf(l.pos, "//go:linkname only allowed in Go files that import \"unsafe\"")
+				continue
+			}
+
+			switch obj := pw.curpkg.Scope().Lookup(l.local).(type) {
+			case *types2.Func, *types2.Var:
+				if _, ok := pw.linknames[obj]; !ok {
+					pw.linknames[obj] = l.remote
+				} else {
+					pw.errorf(l.pos, "duplicate //go:linkname for %s", l.local)
+				}
+
+			default:
+				// TODO(mdempsky): Enable after #42938 is fixed.
+				if false {
+					pw.errorf(l.pos, "//go:linkname must refer to declared function or variable")
+				}
+			}
+		}
+	}
+}
+
+func (pw *pkgWriter) checkPragmas(p syntax.Pragma, allowed ir.PragmaFlag, embedOK bool) {
+	if p == nil {
+		return
+	}
+	pragma := p.(*pragmas)
+
+	for _, pos := range pragma.Pos {
+		if pos.Flag&^allowed != 0 {
+			pw.errorf(pos.Pos, "misplaced compiler directive")
+		}
+	}
+
+	if !embedOK {
+		for _, e := range pragma.Embeds {
+			pw.errorf(e.Pos, "misplaced go:embed directive")
+		}
+	}
+}
+
+func (w *writer) pkgInit(noders []*noder) {
+	if quirksMode() {
+		posBases := posBasesOf(noders)
+		w.len(len(posBases))
+		for _, posBase := range posBases {
+			w.posBase(posBase)
+		}
+
+		objs := importedObjsOf(w.p.curpkg, w.p.info, noders)
+		w.len(len(objs))
+		for _, obj := range objs {
+			w.qualifiedIdent(obj)
+		}
+	}
+
+	w.len(len(w.p.cgoPragmas))
+	for _, cgoPragma := range w.p.cgoPragmas {
+		w.strings(cgoPragma)
+	}
+
+	w.sync(syncDecls)
+	for _, p := range noders {
+		for _, decl := range p.file.DeclList {
+			w.pkgDecl(decl)
+		}
+	}
+	w.code(declEnd)
+
+	w.sync(syncEOF)
+}
+
+func (w *writer) pkgDecl(decl syntax.Decl) {
+	switch decl := decl.(type) {
+	default:
+		w.p.unexpected("declaration", decl)
+
+	case *syntax.ImportDecl:
+
+	case *syntax.ConstDecl:
+		w.code(declOther)
+		w.pkgObjs(decl.NameList...)
+
+	case *syntax.FuncDecl:
+		if decl.Name.Value == "_" {
+			break // skip blank functions
+		}
+
+		obj := w.p.info.Defs[decl.Name].(*types2.Func)
+		sig := obj.Type().(*types2.Signature)
+
+		if sig.RParams() != nil || sig.TParams() != nil {
+			break // skip generic functions
+		}
+
+		if recv := sig.Recv(); recv != nil {
+			w.code(declMethod)
+			w.typ(recvBase(recv))
+			w.selector(obj)
+			break
+		}
+
+		w.code(declFunc)
+		w.pkgObjs(decl.Name)
+
+	case *syntax.TypeDecl:
+		if len(decl.TParamList) != 0 {
+			break // skip generic type decls
+		}
+
+		if decl.Name.Value == "_" {
+			break // skip blank type decls
+		}
+
+		name := w.p.info.Defs[decl.Name].(*types2.TypeName)
+		// Skip type declarations for interfaces that are only usable as
+		// type parameter bounds.
+		if iface, ok := name.Type().Underlying().(*types2.Interface); ok && iface.IsConstraint() {
+			break
+		}
+
+		// Skip aliases to uninstantiated generic types.
+		// TODO(mdempsky): Revisit after #46477 is resolved.
+		if name.IsAlias() {
+			named, ok := name.Type().(*types2.Named)
+			if ok && named.TParams().Len() != 0 && len(named.TArgs()) == 0 {
+				break
+			}
+		}
+
+		w.code(declOther)
+		w.pkgObjs(decl.Name)
+
+	case *syntax.VarDecl:
+		w.code(declVar)
+		w.pos(decl)
+		w.pkgObjs(decl.NameList...)
+		w.exprList(decl.Values)
+
+		var embeds []pragmaEmbed
+		if p, ok := decl.Pragma.(*pragmas); ok {
+			embeds = p.Embeds
+		}
+		w.len(len(embeds))
+		for _, embed := range embeds {
+			w.pos(embed.Pos)
+			w.strings(embed.Patterns)
+		}
+	}
+}
+
+func (w *writer) pkgObjs(names ...*syntax.Name) {
+	w.sync(syncDeclNames)
+	w.len(len(names))
+
+	for _, name := range names {
+		obj, ok := w.p.info.Defs[name]
+		assert(ok)
+
+		w.sync(syncDeclName)
+		w.obj(obj, nil)
+	}
+}
+
+// @@@ Helpers
+
+// isDefinedType reports whether obj is a defined type.
+func isDefinedType(obj types2.Object) bool {
+	if obj, ok := obj.(*types2.TypeName); ok {
+		return !obj.IsAlias()
+	}
+	return false
+}
+
+// isGlobal reports whether obj was declared at package scope.
+//
+// Caveat: blank objects are not declared.
+func isGlobal(obj types2.Object) bool {
+	return obj.Parent() == obj.Pkg().Scope()
+}
+
+// lookupObj returns the object that expr refers to, if any. If expr
+// is an explicit instantiation of a generic object, then the type
+// arguments are returned as well.
+func lookupObj(info *types2.Info, expr syntax.Expr) (obj types2.Object, targs []types2.Type) {
+	if index, ok := expr.(*syntax.IndexExpr); ok {
+		if inf, ok := info.Inferred[index]; ok {
+			targs = inf.TArgs
+		} else {
+			args := unpackListExpr(index.Index)
+
+			if len(args) == 1 {
+				tv, ok := info.Types[args[0]]
+				assert(ok)
+				if tv.IsValue() {
+					return // normal index expression
+				}
+			}
+
+			targs = make([]types2.Type, len(args))
+			for i, arg := range args {
+				tv, ok := info.Types[arg]
+				assert(ok)
+				assert(tv.IsType())
+				targs[i] = tv.Type
+			}
+		}
+
+		expr = index.X
+	}
+
+	// Strip package qualifier, if present.
+	if sel, ok := expr.(*syntax.SelectorExpr); ok {
+		if !isPkgQual(info, sel) {
+			return // normal selector expression
+		}
+		expr = sel.Sel
+	}
+
+	if name, ok := expr.(*syntax.Name); ok {
+		obj, _ = info.Uses[name]
+	}
+	return
+}
+
+// isPkgQual reports whether the given selector expression is a
+// package-qualified identifier.
+func isPkgQual(info *types2.Info, sel *syntax.SelectorExpr) bool {
+	if name, ok := sel.X.(*syntax.Name); ok {
+		_, isPkgName := info.Uses[name].(*types2.PkgName)
+		return isPkgName
+	}
+	return false
+}
+
+// recvBase returns the base type for the given receiver parameter.
+func recvBase(recv *types2.Var) *types2.Named {
+	typ := recv.Type()
+	if ptr, ok := typ.(*types2.Pointer); ok {
+		typ = ptr.Elem()
+	}
+	return typ.(*types2.Named)
+}
+
+// namesAsExpr returns a list of names as a syntax.Expr.
+func namesAsExpr(names []*syntax.Name) syntax.Expr {
+	if len(names) == 1 {
+		return names[0]
+	}
+
+	exprs := make([]syntax.Expr, len(names))
+	for i, name := range names {
+		exprs[i] = name
+	}
+	return &syntax.ListExpr{ElemList: exprs}
+}
+
+// fieldIndex returns the index of the struct field named by key.
+func fieldIndex(info *types2.Info, str *types2.Struct, key *syntax.Name) int {
+	field := info.Uses[key].(*types2.Var)
+
+	for i := 0; i < str.NumFields(); i++ {
+		if str.Field(i) == field {
+			return i
+		}
+	}
+
+	panic(fmt.Sprintf("%s: %v is not a field of %v", key.Pos(), field, str))
+}
+
+// objTypeParams returns the type parameters on the given object.
+func objTypeParams(obj types2.Object) *types2.TParamList {
+	switch obj := obj.(type) {
+	case *types2.Func:
+		sig := obj.Type().(*types2.Signature)
+		if sig.Recv() != nil {
+			return sig.RParams()
+		}
+		return sig.TParams()
+	case *types2.TypeName:
+		if !obj.IsAlias() {
+			return obj.Type().(*types2.Named).TParams()
+		}
+	}
+	return nil
+}
+
+func asPragmaFlag(p syntax.Pragma) ir.PragmaFlag {
+	if p == nil {
+		return 0
+	}
+	return p.(*pragmas).Flag
+}
diff --git a/src/cmd/compile/internal/pkginit/initorder.go b/src/cmd/compile/internal/pkginit/initorder.go
index 97d69629fba..0aad63a69f6 100644
--- a/src/cmd/compile/internal/pkginit/initorder.go
+++ b/src/cmd/compile/internal/pkginit/initorder.go
@@ -304,7 +304,7 @@ func (d *initDeps) visit(n ir.Node) {
 		n := n.(*ir.ClosureExpr)
 		d.inspectList(n.Func.Body)
 
-	case ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
+	case ir.ODOTMETH, ir.OMETHVALUE, ir.OMETHEXPR:
 		d.foundDep(ir.MethodExprName(n))
 	}
 }
diff --git a/src/cmd/compile/internal/ppc64/galign.go b/src/cmd/compile/internal/ppc64/galign.go
index 590290fa371..bff3e38f42d 100644
--- a/src/cmd/compile/internal/ppc64/galign.go
+++ b/src/cmd/compile/internal/ppc64/galign.go
@@ -20,7 +20,6 @@ func Init(arch *ssagen.ArchInfo) {
 
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnopdefer
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue
diff --git a/src/cmd/compile/internal/ppc64/ggen.go b/src/cmd/compile/internal/ppc64/ggen.go
index c76962cfb81..3ae6422bf9e 100644
--- a/src/cmd/compile/internal/ppc64/ggen.go
+++ b/src/cmd/compile/internal/ppc64/ggen.go
@@ -53,30 +53,3 @@ func ginsnop(pp *objw.Progs) *obj.Prog {
 	p.To.Reg = ppc64.REG_R0
 	return p
 }
-
-func ginsnopdefer(pp *objw.Progs) *obj.Prog {
-	// On PPC64 two nops are required in the defer case.
-	//
-	// (see gc/cgen.go, gc/plive.go -- copy of comment below)
-	//
-	// On ppc64, when compiling Go into position
-	// independent code on ppc64le we insert an
-	// instruction to reload the TOC pointer from the
-	// stack as well. See the long comment near
-	// jmpdefer in runtime/asm_ppc64.s for why.
-	// If the MOVD is not needed, insert a hardware NOP
-	// so that the same number of instructions are used
-	// on ppc64 in both shared and non-shared modes.
-
-	ginsnop(pp)
-	if base.Ctxt.Flag_shared {
-		p := pp.Prog(ppc64.AMOVD)
-		p.From.Type = obj.TYPE_MEM
-		p.From.Offset = 24
-		p.From.Reg = ppc64.REGSP
-		p.To.Type = obj.TYPE_REG
-		p.To.Reg = ppc64.REG_R2
-		return p
-	}
-	return ginsnop(pp)
-}
diff --git a/src/cmd/compile/internal/reflectdata/alg.go b/src/cmd/compile/internal/reflectdata/alg.go
index d12d9ca0a7d..36ad389647f 100644
--- a/src/cmd/compile/internal/reflectdata/alg.go
+++ b/src/cmd/compile/internal/reflectdata/alg.go
@@ -6,6 +6,7 @@ package reflectdata
 
 import (
 	"fmt"
+	"math/bits"
 	"sort"
 
 	"cmd/compile/internal/base"
@@ -47,6 +48,11 @@ func eqCanPanic(t *types.Type) bool {
 func AlgType(t *types.Type) types.AlgKind {
 	a, _ := types.AlgType(t)
 	if a == types.AMEM {
+		if t.Alignment() < int64(base.Ctxt.Arch.Alignment) && t.Alignment() < t.Width {
+			// For example, we can't treat [2]int16 as an int32 if int32s require
+			// 4-byte alignment. See issue 46283.
+			return a
+		}
 		switch t.Width {
 		case 0:
 			return types.AMEM0
@@ -673,8 +679,7 @@ func EqString(s, t ir.Node) (eqlen *ir.BinaryExpr, eqmem *ir.CallExpr) {
 
 	fn := typecheck.LookupRuntime("memequal")
 	fn = typecheck.SubstArgTypes(fn, types.Types[types.TUINT8], types.Types[types.TUINT8])
-	call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, []ir.Node{sptr, tptr, ir.Copy(slen)})
-	typecheck.Call(call)
+	call := typecheck.Call(base.Pos, fn, []ir.Node{sptr, tptr, ir.Copy(slen)}, false).(*ir.CallExpr)
 
 	cmp := ir.NewBinaryExpr(base.Pos, ir.OEQ, slen, tlen)
 	cmp = typecheck.Expr(cmp).(*ir.BinaryExpr)
@@ -710,8 +715,7 @@ func EqInterface(s, t ir.Node) (eqtab *ir.BinaryExpr, eqdata *ir.CallExpr) {
 	sdata.SetTypecheck(1)
 	tdata.SetTypecheck(1)
 
-	call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, []ir.Node{stab, sdata, tdata})
-	typecheck.Call(call)
+	call := typecheck.Call(base.Pos, fn, []ir.Node{stab, sdata, tdata}, false).(*ir.CallExpr)
 
 	cmp := ir.NewBinaryExpr(base.Pos, ir.OEQ, stab, ttab)
 	cmp = typecheck.Expr(cmp).(*ir.BinaryExpr)
@@ -769,6 +773,20 @@ func memrun(t *types.Type, start int) (size int64, next int) {
 		if f := t.Field(next); f.Sym.IsBlank() || !isRegularMemory(f.Type) {
 			break
 		}
+		// For issue 46283, don't combine fields if the resulting load would
+		// require a larger alignment than the component fields.
+		if base.Ctxt.Arch.Alignment > 1 {
+			align := t.Alignment()
+			if off := t.Field(start).Offset; off&(align-1) != 0 {
+				// Offset is less aligned than the containing type.
+				// Use offset to determine alignment.
+				align = 1 << uint(bits.TrailingZeros64(uint64(off)))
+			}
+			size := t.Field(next).End() - t.Field(start).Offset
+			if size > align {
+				break
+			}
+		}
 	}
 	return t.Field(next-1).End() - t.Field(start).Offset, next
 }
diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
index 034a092d6ce..74907fca28c 100644
--- a/src/cmd/compile/internal/reflectdata/reflect.go
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -5,6 +5,7 @@
 package reflectdata
 
 import (
+	"encoding/binary"
 	"fmt"
 	"internal/buildcfg"
 	"os"
@@ -27,23 +28,13 @@ import (
 	"cmd/internal/src"
 )
 
-type itabEntry struct {
-	t, itype *types.Type
-	lsym     *obj.LSym // symbol of the itab itself
-
-	// symbols of each method in
-	// the itab, sorted by byte offset;
-	// filled in by CompileITabs
-	entries []*obj.LSym
-}
-
 type ptabEntry struct {
 	s *types.Sym
 	t *types.Type
 }
 
-func CountTabs() (numPTabs, numITabs int) {
-	return len(ptabs), len(itabs)
+func CountPTabs() int {
+	return len(ptabs)
 }
 
 // runtime interface and reflection data structures
@@ -55,7 +46,6 @@ var (
 	gcsymmu  sync.Mutex // protects gcsymset and gcsymslice
 	gcsymset = make(map[*types.Type]struct{})
 
-	itabs []itabEntry
 	ptabs []*ir.Name
 )
 
@@ -312,6 +302,10 @@ func MapIterType(t *types.Type) *types.Type {
 // methods returns the methods of the non-interface type t, sorted by name.
 // Generates stub functions as needed.
 func methods(t *types.Type) []*typeSig {
+	if t.HasShape() {
+		// Shape types have no methods.
+		return nil
+	}
 	// method type
 	mt := types.ReceiverBaseType(t)
 
@@ -320,13 +314,6 @@ func methods(t *types.Type) []*typeSig {
 	}
 	typecheck.CalcMethods(mt)
 
-	// type stored in interface word
-	it := t
-
-	if !types.IsDirectIface(it) {
-		it = types.NewPtr(t)
-	}
-
 	// make list of methods for t,
 	// generating code if necessary.
 	var ms []*typeSig
@@ -354,8 +341,8 @@ func methods(t *types.Type) []*typeSig {
 
 		sig := &typeSig{
 			name:  f.Sym,
-			isym:  methodWrapper(it, f),
-			tsym:  methodWrapper(t, f),
+			isym:  methodWrapper(t, f, true),
+			tsym:  methodWrapper(t, f, false),
 			type_: typecheck.NewMethodType(f.Type, t),
 			mtype: typecheck.NewMethodType(f.Type, nil),
 		}
@@ -393,7 +380,7 @@ func imethods(t *types.Type) []*typeSig {
 		// IfaceType.Method is not in the reflect data.
 		// Generate the method body, so that compiled
 		// code can refer to it.
-		methodWrapper(t, f)
+		methodWrapper(t, f, false)
 	}
 
 	return methods
@@ -473,21 +460,25 @@ func dnameField(lsym *obj.LSym, ot int, spkg *types.Pkg, ft *types.Field) int {
 
 // dnameData writes the contents of a reflect.name into s at offset ot.
 func dnameData(s *obj.LSym, ot int, name, tag string, pkg *types.Pkg, exported bool) int {
-	if len(name) > 1<<16-1 {
-		base.Fatalf("name too long: %s", name)
+	if len(name) >= 1<<29 {
+		base.Fatalf("name too long: %d %s...", len(name), name[:1024])
 	}
-	if len(tag) > 1<<16-1 {
-		base.Fatalf("tag too long: %s", tag)
+	if len(tag) >= 1<<29 {
+		base.Fatalf("tag too long: %d %s...", len(tag), tag[:1024])
 	}
+	var nameLen [binary.MaxVarintLen64]byte
+	nameLenLen := binary.PutUvarint(nameLen[:], uint64(len(name)))
+	var tagLen [binary.MaxVarintLen64]byte
+	tagLenLen := binary.PutUvarint(tagLen[:], uint64(len(tag)))
 
 	// Encode name and tag. See reflect/type.go for details.
 	var bits byte
-	l := 1 + 2 + len(name)
+	l := 1 + nameLenLen + len(name)
 	if exported {
 		bits |= 1 << 0
 	}
 	if len(tag) > 0 {
-		l += 2 + len(tag)
+		l += tagLenLen + len(tag)
 		bits |= 1 << 1
 	}
 	if pkg != nil {
@@ -495,14 +486,12 @@ func dnameData(s *obj.LSym, ot int, name, tag string, pkg *types.Pkg, exported b
 	}
 	b := make([]byte, l)
 	b[0] = bits
-	b[1] = uint8(len(name) >> 8)
-	b[2] = uint8(len(name))
-	copy(b[3:], name)
+	copy(b[1:], nameLen[:nameLenLen])
+	copy(b[1+nameLenLen:], name)
 	if len(tag) > 0 {
-		tb := b[3+len(name):]
-		tb[0] = uint8(len(tag) >> 8)
-		tb[1] = uint8(len(tag))
-		copy(tb[2:], tag)
+		tb := b[1+nameLenLen+len(name):]
+		copy(tb, tagLen[:tagLenLen])
+		copy(tb[tagLenLen:], tag)
 	}
 
 	ot = int(s.WriteBytes(base.Ctxt, int64(ot), b))
@@ -666,7 +655,7 @@ var kinds = []int{
 // tflag is documented in reflect/type.go.
 //
 // tflag values must be kept in sync with copies in:
-//	cmd/compile/internal/gc/reflect.go
+//	cmd/compile/internal/reflectdata/reflect.go
 //	cmd/link/internal/ld/decodesym.go
 //	reflect/type.go
 //	runtime/type.go
@@ -732,7 +721,7 @@ func dcommontype(lsym *obj.LSym, t *types.Type) int {
 	}
 
 	exported := false
-	p := t.LongString()
+	p := t.NameString()
 	// If we're writing out type T,
 	// we are very likely to write out type *T as well.
 	// Use the string "*T"[1:] for "T", so that the two
@@ -796,11 +785,11 @@ func dcommontype(lsym *obj.LSym, t *types.Type) int {
 // TrackSym returns the symbol for tracking use of field/method f, assumed
 // to be a member of struct/interface type t.
 func TrackSym(t *types.Type, f *types.Field) *obj.LSym {
-	return base.PkgLinksym("go.track", t.ShortString()+"."+f.Sym.Name, obj.ABI0)
+	return base.PkgLinksym("go.track", t.LinkString()+"."+f.Sym.Name, obj.ABI0)
 }
 
 func TypeSymPrefix(prefix string, t *types.Type) *types.Sym {
-	p := prefix + "." + t.ShortString()
+	p := prefix + "." + t.LinkString()
 	s := types.TypeSymLookup(p)
 
 	// This function is for looking up type-related generated functions
@@ -845,16 +834,28 @@ func TypePtr(t *types.Type) *ir.AddrExpr {
 	return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr)
 }
 
-func ITabAddr(t, itype *types.Type) *ir.AddrExpr {
-	if t == nil || (t.IsPtr() && t.Elem() == nil) || t.IsUntyped() || !itype.IsInterface() || itype.IsEmptyInterface() {
-		base.Fatalf("ITabAddr(%v, %v)", t, itype)
-	}
-	s, existed := ir.Pkgs.Itab.LookupOK(t.ShortString() + "," + itype.ShortString())
+// ITabLsym returns the LSym representing the itab for concreate type typ
+// implementing interface iface.
+func ITabLsym(typ, iface *types.Type) *obj.LSym {
+	s, existed := ir.Pkgs.Itab.LookupOK(typ.LinkString() + "," + iface.LinkString())
+	lsym := s.Linksym()
+
 	if !existed {
-		itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: s.Linksym()})
+		writeITab(lsym, typ, iface)
+	}
+	return lsym
+}
+
+// ITabAddr returns an expression representing a pointer to the itab
+// for concrete type typ implementing interface iface.
+func ITabAddr(typ, iface *types.Type) *ir.AddrExpr {
+	s, existed := ir.Pkgs.Itab.LookupOK(typ.LinkString() + "," + iface.LinkString())
+	lsym := s.Linksym()
+
+	if !existed {
+		writeITab(lsym, typ, iface)
 	}
 
-	lsym := s.Linksym()
 	n := ir.NewLinksymExpr(base.Pos, lsym, types.Types[types.TUINT8])
 	return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr)
 }
@@ -942,25 +943,27 @@ func writeType(t *types.Type) *obj.LSym {
 	if t.IsPtr() && t.Sym() == nil && t.Elem().Sym() != nil {
 		tbase = t.Elem()
 	}
+	if tbase.Kind() == types.TFORW {
+		base.Fatalf("unresolved defined type: %v", tbase)
+	}
+
 	dupok := 0
-	if tbase.Sym() == nil {
+	if tbase.Sym() == nil || tbase.HasShape() { // TODO(mdempsky): Probably need DUPOK for instantiated types too.
 		dupok = obj.DUPOK
 	}
 
-	if base.Ctxt.Pkgpath != "runtime" || (tbase != types.Types[tbase.Kind()] && tbase != types.ByteType && tbase != types.RuneType && tbase != types.ErrorType) { // int, float, etc
-		// named types from other files are defined only by those files
-		if tbase.Sym() != nil && tbase.Sym().Pkg != types.LocalPkg {
-			if i := typecheck.BaseTypeIndex(t); i >= 0 {
-				lsym.Pkg = tbase.Sym().Pkg.Prefix
-				lsym.SymIdx = int32(i)
-				lsym.Set(obj.AttrIndexed, true)
-			}
-			return lsym
-		}
-		// TODO(mdempsky): Investigate whether this can happen.
-		if tbase.Kind() == types.TFORW {
-			return lsym
+	if !NeedEmit(tbase) {
+		if i := typecheck.BaseTypeIndex(t); i >= 0 {
+			lsym.Pkg = tbase.Sym().Pkg.Prefix
+			lsym.SymIdx = int32(i)
+			lsym.Set(obj.AttrIndexed, true)
 		}
+
+		// TODO(mdempsky): Investigate whether this still happens.
+		// If we know we don't need to emit code for a type,
+		// we should have a link-symbol index for it.
+		// See also TODO in NeedEmit.
+		return lsym
 	}
 
 	ot := 0
@@ -1109,6 +1112,15 @@ func writeType(t *types.Type) *obj.LSym {
 		}
 		ot = objw.Uint32(lsym, ot, flags)
 		ot = dextratype(lsym, ot, t, 0)
+		if u := t.Underlying(); u != t {
+			// If t is a named map type, also keep the underlying map
+			// type live in the binary. This is important to make sure that
+			// a named map and that same map cast to its underlying type via
+			// reflection, use the same hash function. See issue 37716.
+			r := obj.Addrel(lsym)
+			r.Sym = writeType(u)
+			r.Type = objabi.R_KEEP
+		}
 
 	case types.TPTR:
 		if t.Elem().Kind() == types.TANY {
@@ -1241,88 +1253,11 @@ func InterfaceMethodOffset(ityp *types.Type, i int64) int64 {
 	return int64(commonSize()+4*types.PtrSize+uncommonSize(ityp)) + i*8
 }
 
-// for each itabEntry, gather the methods on
-// the concrete type that implement the interface
-func CompileITabs() {
-	for i := range itabs {
-		tab := &itabs[i]
-		methods := genfun(tab.t, tab.itype)
-		if len(methods) == 0 {
-			continue
-		}
-		tab.entries = methods
-	}
-}
-
-// for the given concrete type and interface
-// type, return the (sorted) set of methods
-// on the concrete type that implement the interface
-func genfun(t, it *types.Type) []*obj.LSym {
-	if t == nil || it == nil {
-		return nil
-	}
-	sigs := imethods(it)
-	methods := methods(t)
-	out := make([]*obj.LSym, 0, len(sigs))
-	// TODO(mdempsky): Short circuit before calling methods(t)?
-	// See discussion on CL 105039.
-	if len(sigs) == 0 {
-		return nil
-	}
-
-	// both sigs and methods are sorted by name,
-	// so we can find the intersect in a single pass
-	for _, m := range methods {
-		if m.name == sigs[0].name {
-			out = append(out, m.isym)
-			sigs = sigs[1:]
-			if len(sigs) == 0 {
-				break
-			}
-		}
-	}
-
-	if len(sigs) != 0 {
-		base.Fatalf("incomplete itab")
-	}
-
-	return out
-}
-
-// ITabSym uses the information gathered in
-// CompileITabs to de-virtualize interface methods.
-// Since this is called by the SSA backend, it shouldn't
-// generate additional Nodes, Syms, etc.
-func ITabSym(it *obj.LSym, offset int64) *obj.LSym {
-	var syms []*obj.LSym
-	if it == nil {
-		return nil
-	}
-
-	for i := range itabs {
-		e := &itabs[i]
-		if e.lsym == it {
-			syms = e.entries
-			break
-		}
-	}
-	if syms == nil {
-		return nil
-	}
-
-	// keep this arithmetic in sync with *itab layout
-	methodnum := int((offset - 2*int64(types.PtrSize) - 8) / int64(types.PtrSize))
-	if methodnum >= len(syms) {
-		return nil
-	}
-	return syms[methodnum]
-}
-
 // NeedRuntimeType ensures that a runtime type descriptor is emitted for t.
 func NeedRuntimeType(t *types.Type) {
 	if t.HasTParam() {
-		// Generic types don't have a runtime type descriptor (but will
-		// have a dictionary)
+		// Generic types don't really exist at run-time and have no runtime
+		// type descriptor.  But we do write out shape types.
 		return
 	}
 	if _, ok := signatset[t]; !ok {
@@ -1364,29 +1299,66 @@ func WriteRuntimeTypes() {
 	}
 }
 
-func WriteTabs() {
-	// process itabs
-	for _, i := range itabs {
-		// dump empty itab symbol into i.sym
-		// type itab struct {
-		//   inter  *interfacetype
-		//   _type  *_type
-		//   hash   uint32
-		//   _      [4]byte
-		//   fun    [1]uintptr // variable sized
-		// }
-		o := objw.SymPtr(i.lsym, 0, writeType(i.itype), 0)
-		o = objw.SymPtr(i.lsym, o, writeType(i.t), 0)
-		o = objw.Uint32(i.lsym, o, types.TypeHash(i.t)) // copy of type hash
-		o += 4                                          // skip unused field
-		for _, fn := range genfun(i.t, i.itype) {
-			o = objw.SymPtrWeak(i.lsym, o, fn, 0) // method pointer for each method
-		}
-		// Nothing writes static itabs, so they are read only.
-		objw.Global(i.lsym, int32(o), int16(obj.DUPOK|obj.RODATA))
-		i.lsym.Set(obj.AttrContentAddressable, true)
+// writeITab writes the itab for concrete type typ implementing
+// interface iface.
+func writeITab(lsym *obj.LSym, typ, iface *types.Type) {
+	// TODO(mdempsky): Fix methodWrapper, geneq, and genhash (and maybe
+	// others) to stop clobbering these.
+	oldpos, oldfn := base.Pos, ir.CurFunc
+	defer func() { base.Pos, ir.CurFunc = oldpos, oldfn }()
+
+	if typ == nil || (typ.IsPtr() && typ.Elem() == nil) || typ.IsUntyped() || iface == nil || !iface.IsInterface() || iface.IsEmptyInterface() {
+		base.Fatalf("writeITab(%v, %v)", typ, iface)
 	}
 
+	sigs := iface.AllMethods().Slice()
+	entries := make([]*obj.LSym, 0, len(sigs))
+
+	// both sigs and methods are sorted by name,
+	// so we can find the intersection in a single pass
+	for _, m := range methods(typ) {
+		if m.name == sigs[0].Sym {
+			entries = append(entries, m.isym)
+			if m.isym == nil {
+				panic("NO ISYM")
+			}
+			sigs = sigs[1:]
+			if len(sigs) == 0 {
+				break
+			}
+		}
+		if sigs[0].Sym.Name == "==" {
+			sigs = sigs[1:]
+			if len(sigs) == 0 {
+				break
+			}
+		}
+	}
+	if len(sigs) != 0 {
+		base.Fatalf("incomplete itab")
+	}
+
+	// dump empty itab symbol into i.sym
+	// type itab struct {
+	//   inter  *interfacetype
+	//   _type  *_type
+	//   hash   uint32
+	//   _      [4]byte
+	//   fun    [1]uintptr // variable sized
+	// }
+	o := objw.SymPtr(lsym, 0, writeType(iface), 0)
+	o = objw.SymPtr(lsym, o, writeType(typ), 0)
+	o = objw.Uint32(lsym, o, types.TypeHash(typ)) // copy of type hash
+	o += 4                                        // skip unused field
+	for _, fn := range entries {
+		o = objw.SymPtrWeak(lsym, o, fn, 0) // method pointer for each method
+	}
+	// Nothing writes static itabs, so they are read only.
+	objw.Global(lsym, int32(o), int16(obj.DUPOK|obj.RODATA))
+	lsym.Set(obj.AttrContentAddressable, true)
+}
+
+func WriteTabs() {
 	// process ptabs
 	if types.LocalPkg.Name == "main" && len(ptabs) > 0 {
 		ot := 0
@@ -1468,7 +1440,7 @@ func WriteBasicTypes() {
 
 type typeAndStr struct {
 	t       *types.Type
-	short   string
+	short   string // "short" here means NameString
 	regular string
 }
 
@@ -1481,8 +1453,13 @@ func (a typesByString) Less(i, j int) bool {
 	}
 	// When the only difference between the types is whether
 	// they refer to byte or uint8, such as **byte vs **uint8,
-	// the types' ShortStrings can be identical.
+	// the types' NameStrings can be identical.
 	// To preserve deterministic sort ordering, sort these by String().
+	//
+	// TODO(mdempsky): This all seems suspect. Using LinkString would
+	// avoid naming collisions, and there shouldn't be a reason to care
+	// about "byte" vs "uint8": they share the same runtime type
+	// descriptor anyway.
 	if a[i].regular != a[j].regular {
 		return a[i].regular < a[j].regular
 	}
@@ -1490,8 +1467,8 @@ func (a typesByString) Less(i, j int) bool {
 	// will be equal for the above checks, but different in DWARF output.
 	// Sort by source position to ensure deterministic order.
 	// See issues 27013 and 30202.
-	if a[i].t.Kind() == types.TINTER && a[i].t.Methods().Len() > 0 {
-		return a[i].t.Methods().Index(0).Pos.Before(a[j].t.Methods().Index(0).Pos)
+	if a[i].t.Kind() == types.TINTER && a[i].t.AllMethods().Len() > 0 {
+		return a[i].t.AllMethods().Index(0).Pos.Before(a[j].t.AllMethods().Index(0).Pos)
 	}
 	return false
 }
@@ -1756,6 +1733,49 @@ func CollectPTabs() {
 	}
 }
 
+// NeedEmit reports whether typ is a type that we need to emit code
+// for (e.g., runtime type descriptors, method wrappers).
+func NeedEmit(typ *types.Type) bool {
+	// TODO(mdempsky): Export data should keep track of which anonymous
+	// and instantiated types were emitted, so at least downstream
+	// packages can skip re-emitting them.
+	//
+	// Perhaps we can just generalize the linker-symbol indexing to
+	// track the index of arbitrary types, not just defined types, and
+	// use its presence to detect this. The same idea would work for
+	// instantiated generic functions too.
+
+	switch sym := typ.Sym(); {
+	case sym == nil:
+		// Anonymous type; possibly never seen before or ever again.
+		// Need to emit to be safe (however, see TODO above).
+		return true
+
+	case sym.Pkg == types.LocalPkg:
+		// Local defined type; our responsibility.
+		return true
+
+	case base.Ctxt.Pkgpath == "runtime" && (sym.Pkg == types.BuiltinPkg || sym.Pkg == ir.Pkgs.Unsafe):
+		// Package runtime is responsible for including code for builtin
+		// types (predeclared and package unsafe).
+		return true
+
+	case typ.IsFullyInstantiated():
+		// Instantiated type; possibly instantiated with unique type arguments.
+		// Need to emit to be safe (however, see TODO above).
+		return true
+
+	case typ.HasShape():
+		// Shape type; need to emit even though it lives in the .shape package.
+		// TODO: make sure the linker deduplicates them (see dupok in writeType above).
+		return true
+
+	default:
+		// Should have been emitted by an imported package.
+		return false
+	}
+}
+
 // Generate a wrapper function to convert from
 // a receiver of type T to a receiver of type U.
 // That is,
@@ -1776,7 +1796,45 @@ func CollectPTabs() {
 //
 //	rcvr - U
 //	method - M func (t T)(), a TFIELD type struct
-func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
+//
+// Also wraps methods on instantiated generic types for use in itab entries.
+// For an instantiated generic type G[int], we generate wrappers like:
+// G[int] pointer shaped:
+//	func (x G[int]) f(arg) {
+//		.inst.G[int].f(dictionary, x, arg)
+// 	}
+// G[int] not pointer shaped:
+//	func (x *G[int]) f(arg) {
+//		.inst.G[int].f(dictionary, *x, arg)
+// 	}
+// These wrappers are always fully stenciled.
+func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSym {
+	orig := rcvr
+	if forItab && !types.IsDirectIface(rcvr) {
+		rcvr = rcvr.PtrTo()
+	}
+
+	generic := false
+	// We don't need a dictionary if we are reaching a method (possibly via an
+	// embedded field) which is an interface method.
+	if !types.IsInterfaceMethod(method.Type) {
+		rcvr1 := rcvr
+		if rcvr1.IsPtr() {
+			rcvr1 = rcvr.Elem()
+		}
+		if len(rcvr1.RParams()) > 0 {
+			// If rcvr has rparams, remember method as generic, which
+			// means we need to add a dictionary to the wrapper.
+			generic = true
+			targs := rcvr1.RParams()
+			for _, t := range targs {
+				if t.HasShape() {
+					base.Fatalf("method on type instantiated with shapes targ:%+v rcvr:%+v", t, rcvr)
+				}
+			}
+		}
+	}
+
 	newnam := ir.MethodSym(rcvr, method.Sym)
 	lsym := newnam.Linksym()
 	if newnam.Siggen() {
@@ -1784,19 +1842,18 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	}
 	newnam.SetSiggen(true)
 
-	if types.Identical(rcvr, method.Type.Recv().Type) {
+	// Except in quirks mode, unified IR creates its own wrappers.
+	if base.Debug.Unified != 0 && base.Debug.UnifiedQuirks == 0 {
 		return lsym
 	}
 
-	// Only generate (*T).M wrappers for T.M in T's own package.
-	if rcvr.IsPtr() && rcvr.Elem() == method.Type.Recv().Type &&
-		rcvr.Elem().Sym() != nil && rcvr.Elem().Sym().Pkg != types.LocalPkg {
+	// For generic methods, we need to generate the wrapper even if the receiver
+	// types are identical, because we want to add the dictionary.
+	if !generic && types.Identical(rcvr, method.Type.Recv().Type) {
 		return lsym
 	}
 
-	// Only generate I.M wrappers for I in I's own package
-	// but keep doing it for error.Error (was issue #29304).
-	if rcvr.IsInterface() && rcvr.Sym() != nil && rcvr.Sym().Pkg != types.LocalPkg && rcvr != types.ErrorType {
+	if !NeedEmit(rcvr) || rcvr.IsPtr() && !NeedEmit(rcvr.Elem()) {
 		return lsym
 	}
 
@@ -1817,9 +1874,10 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	nthis := ir.AsNode(tfn.Type().Recv().Nname)
 
 	methodrcvr := method.Type.Recv().Type
+	indirect := rcvr.IsPtr() && rcvr.Elem() == methodrcvr
 
 	// generate nil pointer check for better error
-	if rcvr.IsPtr() && rcvr.Elem() == methodrcvr {
+	if indirect {
 		// generating wrapper from *T to T.
 		n := ir.NewIfStmt(base.Pos, nil, nil, nil)
 		n.Cond = ir.NewBinaryExpr(base.Pos, ir.OEQ, nthis, typecheck.NodNil())
@@ -1829,7 +1887,6 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	}
 
 	dot := typecheck.AddImplicitDots(ir.NewSelectorExpr(base.Pos, ir.OXDOT, nthis, method.Sym))
-
 	// generate call
 	// It's not possible to use a tail call when dynamic linking on ppc64le. The
 	// bad scenario is when a local call is made to the wrapper: the wrapper will
@@ -1841,7 +1898,7 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	// Disable tailcall for RegabiArgs for now. The IR does not connect the
 	// arguments with the OTAILCALL node, and the arguments are not marshaled
 	// correctly.
-	if !base.Flag.Cfg.Instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !types.IsInterfaceMethod(method.Type) && !(base.Ctxt.Arch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) && !buildcfg.Experiment.RegabiArgs {
+	if !base.Flag.Cfg.Instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !types.IsInterfaceMethod(method.Type) && !(base.Ctxt.Arch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) && !buildcfg.Experiment.RegabiArgs && !generic {
 		// generate tail call: adjust pointer receiver and jump to embedded method.
 		left := dot.X // skip final .M
 		if !left.Type().IsPtr() {
@@ -1852,8 +1909,72 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 		fn.Body.Append(ir.NewTailCallStmt(base.Pos, method.Nname.(*ir.Name)))
 	} else {
 		fn.SetWrapper(true) // ignore frame for panic+recover matching
-		call := ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
-		call.Args = ir.ParamNames(tfn.Type())
+		var call *ir.CallExpr
+
+		if generic && dot.X != nthis {
+			// TODO: for now, we don't try to generate dictionary wrappers for
+			// any methods involving embedded fields, because we're not
+			// generating the needed dictionaries in instantiateMethods.
+			generic = false
+		}
+
+		if generic {
+			var args []ir.Node
+			var targs []*types.Type
+			if rcvr.IsPtr() {
+				targs = rcvr.Elem().RParams()
+			} else {
+				targs = rcvr.RParams()
+			}
+			if strings.HasPrefix(ir.MethodSym(orig, method.Sym).Name, ".inst.") {
+				fmt.Printf("%s\n", ir.MethodSym(orig, method.Sym).Name)
+				panic("multiple .inst.")
+			}
+			// The wrapper for an auto-generated pointer/non-pointer
+			// receiver method should share the same dictionary as the
+			// corresponding original (user-written) method.
+			baseOrig := orig
+			if baseOrig.IsPtr() && !method.Type.Recv().Type.IsPtr() {
+				baseOrig = baseOrig.Elem()
+			} else if !baseOrig.IsPtr() && method.Type.Recv().Type.IsPtr() {
+				baseOrig = types.NewPtr(baseOrig)
+			}
+			args = append(args, getDictionary(ir.MethodSym(baseOrig, method.Sym), targs))
+			if indirect {
+				args = append(args, ir.NewStarExpr(base.Pos, dot.X))
+			} else if methodrcvr.IsPtr() && methodrcvr.Elem() == dot.X.Type() {
+				// Case where method call is via a non-pointer
+				// embedded field with a pointer method.
+				args = append(args, typecheck.NodAddrAt(base.Pos, dot.X))
+			} else {
+				args = append(args, dot.X)
+			}
+			args = append(args, ir.ParamNames(tfn.Type())...)
+
+			// Target method uses shaped names.
+			targs2 := make([]*types.Type, len(targs))
+			for i, t := range targs {
+				targs2[i] = typecheck.Shapify(t)
+			}
+			targs = targs2
+
+			sym := typecheck.MakeInstName(ir.MethodSym(methodrcvr, method.Sym), targs, true)
+			if sym.Def == nil {
+				// Currently we make sure that we have all the instantiations
+				// we need by generating them all in ../noder/stencil.go:instantiateMethods
+				// TODO: maybe there's a better, more incremental way to generate
+				// only the instantiations we need?
+				base.Fatalf("instantiation %s not found", sym.Name)
+			}
+			target := ir.AsNode(sym.Def)
+			call = ir.NewCallExpr(base.Pos, ir.OCALL, target, args)
+			// Fill-in the generic method node that was not filled in
+			// in instantiateMethod.
+			method.Nname = fn.Nname
+		} else {
+			call = ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
+			call.Args = ir.ParamNames(tfn.Type())
+		}
 		call.IsDDD = tfn.Type().IsVariadic()
 		if method.Type.NumResults() > 0 {
 			ret := ir.NewReturnStmt(base.Pos, nil)
@@ -1873,13 +1994,10 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	ir.CurFunc = fn
 	typecheck.Stmts(fn.Body)
 
-	// Inline calls within (*T).M wrappers. This is safe because we only
-	// generate those wrappers within the same compilation unit as (T).M.
-	// TODO(mdempsky): Investigate why we can't enable this more generally.
-	if rcvr.IsPtr() && rcvr.Elem() == method.Type.Recv().Type && rcvr.Elem().Sym() != nil {
+	if AfterGlobalEscapeAnalysis {
 		inline.InlineCalls(fn)
+		escape.Batch([]*ir.Func{fn}, false)
 	}
-	escape.Batch([]*ir.Func{fn}, false)
 
 	ir.CurFunc = nil
 	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
@@ -1887,11 +2005,21 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
 	return lsym
 }
 
+// AfterGlobalEscapeAnalysis tracks whether package gc has already
+// performed the main, global escape analysis pass. If so,
+// methodWrapper takes responsibility for escape analyzing any
+// generated wrappers.
+var AfterGlobalEscapeAnalysis bool
+
 var ZeroSize int64
 
 // MarkTypeUsedInInterface marks that type t is converted to an interface.
 // This information is used in the linker in dead method elimination.
 func MarkTypeUsedInInterface(t *types.Type, from *obj.LSym) {
+	if t.HasShape() {
+		// Shape types shouldn't be put in interfaces, so we shouldn't ever get here.
+		base.Fatalf("shape types have no methods %+v", t)
+	}
 	tsym := TypeLinksym(t)
 	// Emit a marker relocation. The linker will know the type is converted
 	// to an interface if "from" is reachable.
@@ -1912,9 +2040,55 @@ func MarkUsedIfaceMethod(n *ir.CallExpr) {
 	tsym := TypeLinksym(ityp)
 	r := obj.Addrel(ir.CurFunc.LSym)
 	r.Sym = tsym
-	// dot.Xoffset is the method index * PtrSize (the offset of code pointer
+	// dot.Offset() is the method index * PtrSize (the offset of code pointer
 	// in itab).
 	midx := dot.Offset() / int64(types.PtrSize)
 	r.Add = InterfaceMethodOffset(ityp, midx)
 	r.Type = objabi.R_USEIFACEMETHOD
 }
+
+// MarkUsedIfaceMethodIndex marks that that method number ix (in the AllMethods list)
+// of interface type ityp is used, and should be attached to lsym.
+func MarkUsedIfaceMethodIndex(lsym *obj.LSym, ityp *types.Type, ix int) {
+	tsym := TypeLinksym(ityp)
+	r := obj.Addrel(lsym)
+	r.Sym = tsym
+	r.Add = InterfaceMethodOffset(ityp, int64(ix))
+	r.Type = objabi.R_USEIFACEMETHOD
+}
+
+// getDictionary returns the dictionary for the given named generic function
+// or method, with the given type arguments.
+func getDictionary(gf *types.Sym, targs []*types.Type) ir.Node {
+	if len(targs) == 0 {
+		base.Fatalf("%s should have type arguments", gf.Name)
+	}
+	for _, t := range targs {
+		if t.HasShape() {
+			base.Fatalf("dictionary for %s should only use concrete types: %+v", gf.Name, t)
+		}
+	}
+
+	sym := typecheck.MakeDictName(gf, targs, true)
+
+	// Initialize the dictionary, if we haven't yet already.
+	if lsym := sym.Linksym(); len(lsym.P) == 0 {
+		base.Fatalf("Dictionary should have already been generated: %s.%s", sym.Pkg.Path, sym.Name)
+	}
+
+	// Make a node referencing the dictionary symbol.
+	n := typecheck.NewName(sym)
+	n.SetType(types.Types[types.TUINTPTR]) // should probably be [...]uintptr, but doesn't really matter
+	n.SetTypecheck(1)
+	n.Class = ir.PEXTERN
+	sym.Def = n
+
+	// Return the address of the dictionary.
+	np := typecheck.NodAddr(n)
+	// Note: treat dictionary pointers as uintptrs, so they aren't pointers
+	// with respect to GC. That saves on stack scanning work, write barriers, etc.
+	// We can get away with it because dictionaries are global variables.
+	np.SetType(types.Types[types.TUINTPTR])
+	np.SetTypecheck(1)
+	return np
+}
diff --git a/src/cmd/compile/internal/riscv64/galign.go b/src/cmd/compile/internal/riscv64/galign.go
index 338248a7cf2..846ed8fb380 100644
--- a/src/cmd/compile/internal/riscv64/galign.go
+++ b/src/cmd/compile/internal/riscv64/galign.go
@@ -16,7 +16,6 @@ func Init(arch *ssagen.ArchInfo) {
 	arch.MAXWIDTH = 1 << 50
 
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 	arch.ZeroRange = zeroRange
 
 	arch.SSAMarkMoves = ssaMarkMoves
diff --git a/src/cmd/compile/internal/s390x/galign.go b/src/cmd/compile/internal/s390x/galign.go
index b004a2db0a3..d880834c220 100644
--- a/src/cmd/compile/internal/s390x/galign.go
+++ b/src/cmd/compile/internal/s390x/galign.go
@@ -16,7 +16,6 @@ func Init(arch *ssagen.ArchInfo) {
 
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue
diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index 4ffa047096b..32e3a0860e3 100644
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -147,21 +147,8 @@ type Frontend interface {
 
 	// Given the name for a compound type, returns the name we should use
 	// for the parts of that compound type.
-	SplitString(LocalSlot) (LocalSlot, LocalSlot)
-	SplitInterface(LocalSlot) (LocalSlot, LocalSlot)
-	SplitSlice(LocalSlot) (LocalSlot, LocalSlot, LocalSlot)
-	SplitComplex(LocalSlot) (LocalSlot, LocalSlot)
-	SplitStruct(LocalSlot, int) LocalSlot
-	SplitArray(LocalSlot) LocalSlot              // array must be length 1
-	SplitInt64(LocalSlot) (LocalSlot, LocalSlot) // returns (hi, lo)
 	SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot
 
-	// DerefItab dereferences an itab function
-	// entry, given the symbol of the itab and
-	// the byte offset of the function pointer.
-	// It may return nil.
-	DerefItab(sym *obj.LSym, offset int64) *obj.LSym
-
 	// Line returns a string describing the given position.
 	Line(src.XPos) string
 
@@ -184,7 +171,7 @@ type Frontend interface {
 }
 
 // NewConfig returns a new configuration object for the given architecture.
-func NewConfig(arch string, types Types, ctxt *obj.Link, optimize bool) *Config {
+func NewConfig(arch string, types Types, ctxt *obj.Link, optimize, softfloat bool) *Config {
 	c := &Config{arch: arch, Types: types}
 	c.useAvg = true
 	c.useHmul = true
@@ -203,7 +190,7 @@ func NewConfig(arch string, types Types, ctxt *obj.Link, optimize bool) *Config
 		c.floatParamRegs = paramFloatRegAMD64
 		c.FPReg = framepointerRegAMD64
 		c.LinkReg = linkRegAMD64
-		c.hasGReg = buildcfg.Experiment.RegabiG
+		c.hasGReg = true
 	case "386":
 		c.PtrSize = 4
 		c.RegSize = 4
@@ -235,6 +222,8 @@ func NewConfig(arch string, types Types, ctxt *obj.Link, optimize bool) *Config
 		c.registers = registersARM64[:]
 		c.gpRegMask = gpRegMaskARM64
 		c.fpRegMask = fpRegMaskARM64
+		c.intParamRegs = paramIntRegARM64
+		c.floatParamRegs = paramFloatRegARM64
 		c.FPReg = framepointerRegARM64
 		c.LinkReg = linkRegARM64
 		c.hasGReg = true
@@ -331,6 +320,10 @@ func NewConfig(arch string, types Types, ctxt *obj.Link, optimize bool) *Config
 	c.optimize = optimize
 	c.useSSE = true
 	c.UseFMA = true
+	c.SoftFloat = softfloat
+	if softfloat {
+		c.floatParamRegs = nil // no FP registers in softfloat mode
+	}
 
 	c.ABI0 = abi.NewABIConfig(0, 0, ctxt.FixedFrameSize())
 	c.ABI1 = abi.NewABIConfig(len(c.intParamRegs), len(c.floatParamRegs), ctxt.FixedFrameSize())
diff --git a/src/cmd/compile/internal/ssa/copyelim.go b/src/cmd/compile/internal/ssa/copyelim.go
index 5954d3bec8e..17f65127ee0 100644
--- a/src/cmd/compile/internal/ssa/copyelim.go
+++ b/src/cmd/compile/internal/ssa/copyelim.go
@@ -26,7 +26,7 @@ func copyelim(f *Func) {
 
 	// Update named values.
 	for _, name := range f.Names {
-		values := f.NamedValues[name]
+		values := f.NamedValues[*name]
 		for i, v := range values {
 			if v.Op == OpCopy {
 				values[i] = v.Args[0]
diff --git a/src/cmd/compile/internal/ssa/deadcode.go b/src/cmd/compile/internal/ssa/deadcode.go
index 96b552ecf3b..5d10dfe025e 100644
--- a/src/cmd/compile/internal/ssa/deadcode.go
+++ b/src/cmd/compile/internal/ssa/deadcode.go
@@ -223,7 +223,7 @@ func deadcode(f *Func) {
 	for _, name := range f.Names {
 		j := 0
 		s.clear()
-		values := f.NamedValues[name]
+		values := f.NamedValues[*name]
 		for _, v := range values {
 			if live[v.ID] && !s.contains(v.ID) {
 				values[j] = v
@@ -232,19 +232,19 @@ func deadcode(f *Func) {
 			}
 		}
 		if j == 0 {
-			delete(f.NamedValues, name)
+			delete(f.NamedValues, *name)
 		} else {
 			f.Names[i] = name
 			i++
 			for k := len(values) - 1; k >= j; k-- {
 				values[k] = nil
 			}
-			f.NamedValues[name] = values[:j]
+			f.NamedValues[*name] = values[:j]
 		}
 	}
 	clearNames := f.Names[i:]
 	for j := range clearNames {
-		clearNames[j] = LocalSlot{}
+		clearNames[j] = nil
 	}
 	f.Names = f.Names[:i]
 
diff --git a/src/cmd/compile/internal/ssa/debug.go b/src/cmd/compile/internal/ssa/debug.go
index 0ca435e5157..8e2872363b6 100644
--- a/src/cmd/compile/internal/ssa/debug.go
+++ b/src/cmd/compile/internal/ssa/debug.go
@@ -7,10 +7,13 @@ package ssa
 import (
 	"cmd/compile/internal/abi"
 	"cmd/compile/internal/ir"
+	"cmd/compile/internal/types"
 	"cmd/internal/dwarf"
 	"cmd/internal/obj"
+	"cmd/internal/src"
 	"encoding/hex"
 	"fmt"
+	"internal/buildcfg"
 	"math/bits"
 	"sort"
 	"strings"
@@ -335,6 +338,216 @@ func (s *debugState) stateString(state stateAtPC) string {
 	return strings.Join(strs, "")
 }
 
+// slotCanonicalizer is a table used to lookup and canonicalize
+// LocalSlot's in a type insensitive way (e.g. taking into account the
+// base name, offset, and width of the slot, but ignoring the slot
+// type).
+type slotCanonicalizer struct {
+	slmap  map[slotKey]SlKeyIdx
+	slkeys []LocalSlot
+}
+
+func newSlotCanonicalizer() *slotCanonicalizer {
+	return &slotCanonicalizer{
+		slmap:  make(map[slotKey]SlKeyIdx),
+		slkeys: []LocalSlot{LocalSlot{N: nil}},
+	}
+}
+
+type SlKeyIdx uint32
+
+const noSlot = SlKeyIdx(0)
+
+// slotKey is a type-insensitive encapsulation of a LocalSlot; it
+// is used to key a map within slotCanonicalizer.
+type slotKey struct {
+	name        *ir.Name
+	offset      int64
+	width       int64
+	splitOf     SlKeyIdx // idx in slkeys slice in slotCanonicalizer
+	splitOffset int64
+}
+
+// lookup looks up a LocalSlot in the slot canonicalizer "sc", returning
+// a canonical index for the slot, and adding it to the table if need
+// be. Return value is the canonical slot index, and a boolean indicating
+// whether the slot was found in the table already (TRUE => found).
+func (sc *slotCanonicalizer) lookup(ls LocalSlot) (SlKeyIdx, bool) {
+	split := noSlot
+	if ls.SplitOf != nil {
+		split, _ = sc.lookup(*ls.SplitOf)
+	}
+	k := slotKey{
+		name: ls.N, offset: ls.Off, width: ls.Type.Width,
+		splitOf: split, splitOffset: ls.SplitOffset,
+	}
+	if idx, ok := sc.slmap[k]; ok {
+		return idx, true
+	}
+	rv := SlKeyIdx(len(sc.slkeys))
+	sc.slkeys = append(sc.slkeys, ls)
+	sc.slmap[k] = rv
+	return rv, false
+}
+
+func (sc *slotCanonicalizer) canonSlot(idx SlKeyIdx) LocalSlot {
+	return sc.slkeys[idx]
+}
+
+// PopulateABIInRegArgOps examines the entry block of the function
+// and looks for incoming parameters that have missing or partial
+// OpArg{Int,Float}Reg values, inserting additional values in
+// cases where they are missing. Example:
+//
+//      func foo(s string, used int, notused int) int {
+//        return len(s) + used
+//      }
+//
+// In the function above, the incoming parameter "used" is fully live,
+// "notused" is not live, and "s" is partially live (only the length
+// field of the string is used). At the point where debug value
+// analysis runs, we might expect to see an entry block with:
+//
+//   b1:
+//     v4 = ArgIntReg  {s+8} [0] : BX
+//     v5 = ArgIntReg  {used} [0] : CX
+//
+// While this is an accurate picture of the live incoming params,
+// we also want to have debug locations for non-live params (or
+// their non-live pieces), e.g. something like
+//
+//   b1:
+//     v9 = ArgIntReg <*uint8> {s+0} [0] : AX
+//     v4 = ArgIntReg  {s+8} [0] : BX
+//     v5 = ArgIntReg  {used} [0] : CX
+//     v10 = ArgIntReg  {unused} [0] : DI
+//
+// This function examines the live OpArg{Int,Float}Reg values and
+// synthesizes new (dead) values for the non-live params or the
+// non-live pieces of partially live params.
+//
+func PopulateABIInRegArgOps(f *Func) {
+	pri := f.ABISelf.ABIAnalyzeFuncType(f.Type.FuncType())
+
+	// When manufacturing new slots that correspond to splits of
+	// composite parameters, we want to avoid creating a new sub-slot
+	// that differs from some existing sub-slot only by type, since
+	// the debug location analysis will treat that slot as a separate
+	// entity. To achieve this, create a lookup table of existing
+	// slots that is type-insenstitive.
+	sc := newSlotCanonicalizer()
+	for _, sl := range f.Names {
+		sc.lookup(*sl)
+	}
+
+	// Add slot -> value entry to f.NamedValues if not already present.
+	addToNV := func(v *Value, sl LocalSlot) {
+		values, ok := f.NamedValues[sl]
+		if !ok {
+			// Haven't seen this slot yet.
+			sla := f.localSlotAddr(sl)
+			f.Names = append(f.Names, sla)
+		} else {
+			for _, ev := range values {
+				if v == ev {
+					return
+				}
+			}
+		}
+		values = append(values, v)
+		f.NamedValues[sl] = values
+	}
+
+	newValues := []*Value{}
+
+	abiRegIndexToRegister := func(reg abi.RegIndex) int8 {
+		i := f.ABISelf.FloatIndexFor(reg)
+		if i >= 0 { // float PR
+			return f.Config.floatParamRegs[i]
+		} else {
+			return f.Config.intParamRegs[reg]
+		}
+	}
+
+	// Helper to construct a new OpArg{Float,Int}Reg op value.
+	var pos src.XPos
+	if len(f.Entry.Values) != 0 {
+		pos = f.Entry.Values[0].Pos
+	}
+	synthesizeOpIntFloatArg := func(n *ir.Name, t *types.Type, reg abi.RegIndex, sl LocalSlot) *Value {
+		aux := &AuxNameOffset{n, sl.Off}
+		op, auxInt := ArgOpAndRegisterFor(reg, f.ABISelf)
+		v := f.newValueNoBlock(op, t, pos)
+		v.AuxInt = auxInt
+		v.Aux = aux
+		v.Args = nil
+		v.Block = f.Entry
+		newValues = append(newValues, v)
+		addToNV(v, sl)
+		f.setHome(v, &f.Config.registers[abiRegIndexToRegister(reg)])
+		return v
+	}
+
+	// Make a pass through the entry block looking for
+	// OpArg{Int,Float}Reg ops. Record the slots they use in a table
+	// ("sc"). We use a type-insensitive lookup for the slot table,
+	// since the type we get from the ABI analyzer won't always match
+	// what the compiler uses when creating OpArg{Int,Float}Reg ops.
+	for _, v := range f.Entry.Values {
+		if v.Op == OpArgIntReg || v.Op == OpArgFloatReg {
+			aux := v.Aux.(*AuxNameOffset)
+			sl := LocalSlot{N: aux.Name, Type: v.Type, Off: aux.Offset}
+			// install slot in lookup table
+			idx, _ := sc.lookup(sl)
+			// add to f.NamedValues if not already present
+			addToNV(v, sc.canonSlot(idx))
+		} else if v.Op.IsCall() {
+			// if we hit a call, we've gone too far.
+			break
+		}
+	}
+
+	// Now make a pass through the ABI in-params, looking for params
+	// or pieces of params that we didn't encounter in the loop above.
+	for _, inp := range pri.InParams() {
+		if !isNamedRegParam(inp) {
+			continue
+		}
+		n := inp.Name.(*ir.Name)
+
+		// Param is spread across one or more registers. Walk through
+		// each piece to see whether we've seen an arg reg op for it.
+		types, offsets := inp.RegisterTypesAndOffsets()
+		for k, t := range types {
+			// Note: this recipe for creating a LocalSlot is designed
+			// to be compatible with the one used in expand_calls.go
+			// as opposed to decompose.go. The expand calls code just
+			// takes the base name and creates an offset into it,
+			// without using the SplitOf/SplitOffset fields. The code
+			// in decompose.go does the opposite -- it creates a
+			// LocalSlot object with "Off" set to zero, but with
+			// SplitOf pointing to a parent slot, and SplitOffset
+			// holding the offset into the parent object.
+			pieceSlot := LocalSlot{N: n, Type: t, Off: offsets[k]}
+
+			// Look up this piece to see if we've seen a reg op
+			// for it. If not, create one.
+			_, found := sc.lookup(pieceSlot)
+			if !found {
+				// This slot doesn't appear in the map, meaning it
+				// corresponds to an in-param that is not live, or
+				// a portion of an in-param that is not live/used.
+				// Add a new dummy OpArg{Int,Float}Reg for it.
+				synthesizeOpIntFloatArg(n, t, inp.Registers[k],
+					pieceSlot)
+			}
+		}
+	}
+
+	// Insert the new values into the head of the block.
+	f.Entry.Values = append(newValues, f.Entry.Values...)
+}
+
 // BuildFuncDebug returns debug information for f.
 // f must be fully processed, so that each Value is where it will be when
 // machine code is emitted.
@@ -349,6 +562,10 @@ func BuildFuncDebug(ctxt *obj.Link, f *Func, loggingEnabled bool, stackOffset fu
 	state.stackOffset = stackOffset
 	state.ctxt = ctxt
 
+	if buildcfg.Experiment.RegabiArgs {
+		PopulateABIInRegArgOps(f)
+	}
+
 	if state.loggingEnabled {
 		state.logf("Generating location lists for function %q\n", f.Name)
 	}
@@ -367,12 +584,12 @@ func BuildFuncDebug(ctxt *obj.Link, f *Func, loggingEnabled bool, stackOffset fu
 	state.slots = state.slots[:0]
 	state.vars = state.vars[:0]
 	for i, slot := range f.Names {
-		state.slots = append(state.slots, slot)
+		state.slots = append(state.slots, *slot)
 		if ir.IsSynthetic(slot.N) {
 			continue
 		}
 
-		topSlot := &slot
+		topSlot := slot
 		for topSlot.SplitOf != nil {
 			topSlot = topSlot.SplitOf
 		}
@@ -436,7 +653,7 @@ func BuildFuncDebug(ctxt *obj.Link, f *Func, loggingEnabled bool, stackOffset fu
 		if ir.IsSynthetic(slot.N) {
 			continue
 		}
-		for _, value := range f.NamedValues[slot] {
+		for _, value := range f.NamedValues[*slot] {
 			state.valueNames[value.ID] = append(state.valueNames[value.ID], SlotID(i))
 		}
 	}
@@ -898,8 +1115,14 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 			continue
 		}
 
+		mustBeFirst := func(v *Value) bool {
+			return v.Op == OpPhi || v.Op.isLoweredGetClosurePtr() ||
+				v.Op == OpArgIntReg || v.Op == OpArgFloatReg
+		}
+
 		zeroWidthPending := false
-		apcChangedSize := 0 // size of changedVars for leading Args, Phi, ClosurePtr
+		blockPrologComplete := false // set to true at first non-zero-width op
+		apcChangedSize := 0          // size of changedVars for leading Args, Phi, ClosurePtr
 		// expect to see values in pattern (apc)* (zerowidth|real)*
 		for _, v := range b.Values {
 			slots := state.valueNames[v.ID]
@@ -908,16 +1131,16 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 
 			if opcodeTable[v.Op].zeroWidth {
 				if changed {
-					if hasAnyArgOp(v) || v.Op == OpPhi || v.Op.isLoweredGetClosurePtr() {
+					if mustBeFirst(v) || v.Op == OpArg {
 						// These ranges begin at true beginning of block, not after first instruction
-						if zeroWidthPending {
-							panic(fmt.Errorf("Unexpected op '%s' mixed with OpArg/OpPhi/OpLoweredGetClosurePtr at beginning of block %s in %s\n%s", v.LongString(), b, b.Func.Name, b.Func))
+						if blockPrologComplete && mustBeFirst(v) {
+							panic(fmt.Errorf("Unexpected placement of op '%s' appearing after non-pseudo-op at beginning of block %s in %s\n%s", v.LongString(), b, b.Func.Name, b.Func))
 						}
 						apcChangedSize = len(state.changedVars.contents())
+						// Other zero-width ops must wait on a "real" op.
+						zeroWidthPending = true
 						continue
 					}
-					// Other zero-width ops must wait on a "real" op.
-					zeroWidthPending = true
 				}
 				continue
 			}
@@ -928,6 +1151,7 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 			// Not zero-width; i.e., a "real" instruction.
 
 			zeroWidthPending = false
+			blockPrologComplete = true
 			for i, varID := range state.changedVars.contents() {
 				if i < apcChangedSize { // buffered true start-of-block changes
 					state.updateVar(VarID(varID), v.Block, BlockStart)
diff --git a/src/cmd/compile/internal/ssa/decompose.go b/src/cmd/compile/internal/ssa/decompose.go
index ba48b6b3b96..753d69cebcd 100644
--- a/src/cmd/compile/internal/ssa/decompose.go
+++ b/src/cmd/compile/internal/ssa/decompose.go
@@ -36,64 +36,65 @@ func decomposeBuiltIn(f *Func) {
 	// accumulate new LocalSlots in newNames for addition after the iteration.  This decomposition is for
 	// builtin types with leaf components, and thus there is no need to reprocess the newly create LocalSlots.
 	var toDelete []namedVal
-	var newNames []LocalSlot
+	var newNames []*LocalSlot
 	for i, name := range f.Names {
 		t := name.Type
 		switch {
 		case t.IsInteger() && t.Size() > f.Config.RegSize:
-			hiName, loName := f.fe.SplitInt64(name)
-			newNames = append(newNames, hiName, loName)
-			for j, v := range f.NamedValues[name] {
+			hiName, loName := f.SplitInt64(name)
+			newNames = maybeAppend2(f, newNames, hiName, loName)
+			for j, v := range f.NamedValues[*name] {
 				if v.Op != OpInt64Make {
 					continue
 				}
-				f.NamedValues[hiName] = append(f.NamedValues[hiName], v.Args[0])
-				f.NamedValues[loName] = append(f.NamedValues[loName], v.Args[1])
+				f.NamedValues[*hiName] = append(f.NamedValues[*hiName], v.Args[0])
+				f.NamedValues[*loName] = append(f.NamedValues[*loName], v.Args[1])
 				toDelete = append(toDelete, namedVal{i, j})
 			}
 		case t.IsComplex():
-			rName, iName := f.fe.SplitComplex(name)
-			newNames = append(newNames, rName, iName)
-			for j, v := range f.NamedValues[name] {
+			rName, iName := f.SplitComplex(name)
+			newNames = maybeAppend2(f, newNames, rName, iName)
+			for j, v := range f.NamedValues[*name] {
 				if v.Op != OpComplexMake {
 					continue
 				}
-				f.NamedValues[rName] = append(f.NamedValues[rName], v.Args[0])
-				f.NamedValues[iName] = append(f.NamedValues[iName], v.Args[1])
+				f.NamedValues[*rName] = append(f.NamedValues[*rName], v.Args[0])
+				f.NamedValues[*iName] = append(f.NamedValues[*iName], v.Args[1])
 				toDelete = append(toDelete, namedVal{i, j})
 			}
 		case t.IsString():
-			ptrName, lenName := f.fe.SplitString(name)
-			newNames = append(newNames, ptrName, lenName)
-			for j, v := range f.NamedValues[name] {
+			ptrName, lenName := f.SplitString(name)
+			newNames = maybeAppend2(f, newNames, ptrName, lenName)
+			for j, v := range f.NamedValues[*name] {
 				if v.Op != OpStringMake {
 					continue
 				}
-				f.NamedValues[ptrName] = append(f.NamedValues[ptrName], v.Args[0])
-				f.NamedValues[lenName] = append(f.NamedValues[lenName], v.Args[1])
+				f.NamedValues[*ptrName] = append(f.NamedValues[*ptrName], v.Args[0])
+				f.NamedValues[*lenName] = append(f.NamedValues[*lenName], v.Args[1])
 				toDelete = append(toDelete, namedVal{i, j})
 			}
 		case t.IsSlice():
-			ptrName, lenName, capName := f.fe.SplitSlice(name)
-			newNames = append(newNames, ptrName, lenName, capName)
-			for j, v := range f.NamedValues[name] {
+			ptrName, lenName, capName := f.SplitSlice(name)
+			newNames = maybeAppend2(f, newNames, ptrName, lenName)
+			newNames = maybeAppend(f, newNames, capName)
+			for j, v := range f.NamedValues[*name] {
 				if v.Op != OpSliceMake {
 					continue
 				}
-				f.NamedValues[ptrName] = append(f.NamedValues[ptrName], v.Args[0])
-				f.NamedValues[lenName] = append(f.NamedValues[lenName], v.Args[1])
-				f.NamedValues[capName] = append(f.NamedValues[capName], v.Args[2])
+				f.NamedValues[*ptrName] = append(f.NamedValues[*ptrName], v.Args[0])
+				f.NamedValues[*lenName] = append(f.NamedValues[*lenName], v.Args[1])
+				f.NamedValues[*capName] = append(f.NamedValues[*capName], v.Args[2])
 				toDelete = append(toDelete, namedVal{i, j})
 			}
 		case t.IsInterface():
-			typeName, dataName := f.fe.SplitInterface(name)
-			newNames = append(newNames, typeName, dataName)
-			for j, v := range f.NamedValues[name] {
+			typeName, dataName := f.SplitInterface(name)
+			newNames = maybeAppend2(f, newNames, typeName, dataName)
+			for j, v := range f.NamedValues[*name] {
 				if v.Op != OpIMake {
 					continue
 				}
-				f.NamedValues[typeName] = append(f.NamedValues[typeName], v.Args[0])
-				f.NamedValues[dataName] = append(f.NamedValues[dataName], v.Args[1])
+				f.NamedValues[*typeName] = append(f.NamedValues[*typeName], v.Args[0])
+				f.NamedValues[*dataName] = append(f.NamedValues[*dataName], v.Args[1])
 				toDelete = append(toDelete, namedVal{i, j})
 			}
 		case t.IsFloat():
@@ -107,6 +108,18 @@ func decomposeBuiltIn(f *Func) {
 	f.Names = append(f.Names, newNames...)
 }
 
+func maybeAppend(f *Func, ss []*LocalSlot, s *LocalSlot) []*LocalSlot {
+	if _, ok := f.NamedValues[*s]; !ok {
+		f.NamedValues[*s] = nil
+		return append(ss, s)
+	}
+	return ss
+}
+
+func maybeAppend2(f *Func, ss []*LocalSlot, s1, s2 *LocalSlot) []*LocalSlot {
+	return maybeAppend(f, maybeAppend(f, ss, s1), s2)
+}
+
 func decomposeBuiltInPhi(v *Value) {
 	switch {
 	case v.Type.IsInteger() && v.Type.Size() > v.Block.Func.Config.RegSize:
@@ -230,7 +243,7 @@ func decomposeUser(f *Func) {
 	}
 	// Split up named values into their components.
 	i := 0
-	var newNames []LocalSlot
+	var newNames []*LocalSlot
 	for _, name := range f.Names {
 		t := name.Type
 		switch {
@@ -250,7 +263,7 @@ func decomposeUser(f *Func) {
 // decomposeUserArrayInto creates names for the element(s) of arrays referenced
 // by name where possible, and appends those new names to slots, which is then
 // returned.
-func decomposeUserArrayInto(f *Func, name LocalSlot, slots []LocalSlot) []LocalSlot {
+func decomposeUserArrayInto(f *Func, name *LocalSlot, slots []*LocalSlot) []*LocalSlot {
 	t := name.Type
 	if t.NumElem() == 0 {
 		// TODO(khr): Not sure what to do here.  Probably nothing.
@@ -261,20 +274,20 @@ func decomposeUserArrayInto(f *Func, name LocalSlot, slots []LocalSlot) []LocalS
 		// shouldn't get here due to CanSSA
 		f.Fatalf("array not of size 1")
 	}
-	elemName := f.fe.SplitArray(name)
+	elemName := f.SplitArray(name)
 	var keep []*Value
-	for _, v := range f.NamedValues[name] {
+	for _, v := range f.NamedValues[*name] {
 		if v.Op != OpArrayMake1 {
 			keep = append(keep, v)
 			continue
 		}
-		f.NamedValues[elemName] = append(f.NamedValues[elemName], v.Args[0])
+		f.NamedValues[*elemName] = append(f.NamedValues[*elemName], v.Args[0])
 	}
 	if len(keep) == 0 {
 		// delete the name for the array as a whole
-		delete(f.NamedValues, name)
+		delete(f.NamedValues, *name)
 	} else {
-		f.NamedValues[name] = keep
+		f.NamedValues[*name] = keep
 	}
 
 	if t.Elem().IsArray() {
@@ -289,38 +302,38 @@ func decomposeUserArrayInto(f *Func, name LocalSlot, slots []LocalSlot) []LocalS
 // decomposeUserStructInto creates names for the fields(s) of structs referenced
 // by name where possible, and appends those new names to slots, which is then
 // returned.
-func decomposeUserStructInto(f *Func, name LocalSlot, slots []LocalSlot) []LocalSlot {
-	fnames := []LocalSlot{} // slots for struct in name
+func decomposeUserStructInto(f *Func, name *LocalSlot, slots []*LocalSlot) []*LocalSlot {
+	fnames := []*LocalSlot{} // slots for struct in name
 	t := name.Type
 	n := t.NumFields()
 
 	for i := 0; i < n; i++ {
-		fs := f.fe.SplitStruct(name, i)
+		fs := f.SplitStruct(name, i)
 		fnames = append(fnames, fs)
 		// arrays and structs will be decomposed further, so
 		// there's no need to record a name
 		if !fs.Type.IsArray() && !fs.Type.IsStruct() {
-			slots = append(slots, fs)
+			slots = maybeAppend(f, slots, fs)
 		}
 	}
 
 	makeOp := StructMakeOp(n)
 	var keep []*Value
 	// create named values for each struct field
-	for _, v := range f.NamedValues[name] {
+	for _, v := range f.NamedValues[*name] {
 		if v.Op != makeOp {
 			keep = append(keep, v)
 			continue
 		}
 		for i := 0; i < len(fnames); i++ {
-			f.NamedValues[fnames[i]] = append(f.NamedValues[fnames[i]], v.Args[i])
+			f.NamedValues[*fnames[i]] = append(f.NamedValues[*fnames[i]], v.Args[i])
 		}
 	}
 	if len(keep) == 0 {
 		// delete the name for the struct as a whole
-		delete(f.NamedValues, name)
+		delete(f.NamedValues, *name)
 	} else {
-		f.NamedValues[name] = keep
+		f.NamedValues[*name] = keep
 	}
 
 	// now that this f.NamedValues contains values for the struct
@@ -328,10 +341,10 @@ func decomposeUserStructInto(f *Func, name LocalSlot, slots []LocalSlot) []Local
 	for i := 0; i < n; i++ {
 		if name.Type.FieldType(i).IsStruct() {
 			slots = decomposeUserStructInto(f, fnames[i], slots)
-			delete(f.NamedValues, fnames[i])
+			delete(f.NamedValues, *fnames[i])
 		} else if name.Type.FieldType(i).IsArray() {
 			slots = decomposeUserArrayInto(f, fnames[i], slots)
-			delete(f.NamedValues, fnames[i])
+			delete(f.NamedValues, *fnames[i])
 		}
 	}
 	return slots
@@ -416,9 +429,10 @@ type namedVal struct {
 	locIndex, valIndex int // f.NamedValues[f.Names[locIndex]][valIndex] = key
 }
 
-// deleteNamedVals removes particular values with debugger names from f's naming data structures
+// deleteNamedVals removes particular values with debugger names from f's naming data structures,
+// removes all values with OpInvalid, and re-sorts the list of Names.
 func deleteNamedVals(f *Func, toDelete []namedVal) {
-	// Arrange to delete from larger indices to smaller, to ensure swap-with-end deletion does not invalid pending indices.
+	// Arrange to delete from larger indices to smaller, to ensure swap-with-end deletion does not invalidate pending indices.
 	sort.Slice(toDelete, func(i, j int) bool {
 		if toDelete[i].locIndex != toDelete[j].locIndex {
 			return toDelete[i].locIndex > toDelete[j].locIndex
@@ -430,16 +444,36 @@ func deleteNamedVals(f *Func, toDelete []namedVal) {
 	// Get rid of obsolete names
 	for _, d := range toDelete {
 		loc := f.Names[d.locIndex]
-		vals := f.NamedValues[loc]
+		vals := f.NamedValues[*loc]
 		l := len(vals) - 1
 		if l > 0 {
 			vals[d.valIndex] = vals[l]
-			f.NamedValues[loc] = vals[:l]
-		} else {
-			delete(f.NamedValues, loc)
-			l = len(f.Names) - 1
-			f.Names[d.locIndex] = f.Names[l]
-			f.Names = f.Names[:l]
+		}
+		vals[l] = nil
+		f.NamedValues[*loc] = vals[:l]
+	}
+	// Delete locations with no values attached.
+	end := len(f.Names)
+	for i := len(f.Names) - 1; i >= 0; i-- {
+		loc := f.Names[i]
+		vals := f.NamedValues[*loc]
+		last := len(vals)
+		for j := len(vals) - 1; j >= 0; j-- {
+			if vals[j].Op == OpInvalid {
+				last--
+				vals[j] = vals[last]
+				vals[last] = nil
+			}
+		}
+		if last < len(vals) {
+			f.NamedValues[*loc] = vals[:last]
+		}
+		if len(vals) == 0 {
+			delete(f.NamedValues, *loc)
+			end--
+			f.Names[i] = f.Names[end]
+			f.Names[end] = nil
 		}
 	}
+	f.Names = f.Names[:end]
 }
diff --git a/src/cmd/compile/internal/ssa/expand_calls.go b/src/cmd/compile/internal/ssa/expand_calls.go
index 2852753beeb..a8c6c26dadc 100644
--- a/src/cmd/compile/internal/ssa/expand_calls.go
+++ b/src/cmd/compile/internal/ssa/expand_calls.go
@@ -215,7 +215,7 @@ func (x *expandState) isAlreadyExpandedAggregateType(t *types.Type) bool {
 		return false
 	}
 	return t.IsStruct() || t.IsArray() || t.IsComplex() || t.IsInterface() || t.IsString() || t.IsSlice() ||
-		t.Size() > x.regSize && t.IsInteger()
+		(t.Size() > x.regSize && (t.IsInteger() || (x.f.Config.SoftFloat && t.IsFloat())))
 }
 
 // offsetFrom creates an offset from a pointer, simplifying chained offsets and offsets from SP
@@ -243,10 +243,10 @@ func (x *expandState) offsetFrom(b *Block, from *Value, offset int64, pt *types.
 }
 
 // splitSlots splits one "field" (specified by sfx, offset, and ty) out of the LocalSlots in ls and returns the new LocalSlots this generates.
-func (x *expandState) splitSlots(ls []LocalSlot, sfx string, offset int64, ty *types.Type) []LocalSlot {
-	var locs []LocalSlot
+func (x *expandState) splitSlots(ls []*LocalSlot, sfx string, offset int64, ty *types.Type) []*LocalSlot {
+	var locs []*LocalSlot
 	for i := range ls {
-		locs = append(locs, x.f.fe.SplitSlot(&ls[i], sfx, offset, ty))
+		locs = append(locs, x.f.SplitSlot(ls[i], sfx, offset, ty))
 	}
 	return locs
 }
@@ -301,13 +301,13 @@ func (x *expandState) Printf(format string, a ...interface{}) (n int, err error)
 // It emits the code necessary to implement the leaf select operation that leads to the root.
 //
 // TODO when registers really arrive, must also decompose anything split across two registers or registers and memory.
-func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64, regOffset Abi1RO) []LocalSlot {
+func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64, regOffset Abi1RO) []*LocalSlot {
 	if x.debug {
 		x.indent(3)
 		defer x.indent(-3)
 		x.Printf("rewriteSelect(%s; %s; memOff=%d; regOff=%d)\n", leaf.LongString(), selector.LongString(), offset, regOffset)
 	}
-	var locs []LocalSlot
+	var locs []*LocalSlot
 	leafType := leaf.Type
 	if len(selector.Args) > 0 {
 		w := selector.Args[0]
@@ -380,6 +380,12 @@ func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64,
 		// The OpLoad was created to load the single field of the IData
 		// This case removes that StructSelect.
 		if leafType != selector.Type {
+			if x.f.Config.SoftFloat && selector.Type.IsFloat() {
+				if x.debug {
+					x.Printf("---OpLoad, break\n")
+				}
+				break // softfloat pass will take care of that
+			}
 			x.f.Fatalf("Unexpected Load as selector, leaf=%s, selector=%s\n", leaf.LongString(), selector.LongString())
 		}
 		leaf.copyOf(selector)
@@ -477,7 +483,7 @@ func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64,
 
 	case OpStructSelect:
 		w := selector.Args[0]
-		var ls []LocalSlot
+		var ls []*LocalSlot
 		if w.Type.Kind() != types.TSTRUCT { // IData artifact
 			ls = x.rewriteSelect(leaf, w, offset, regOffset)
 		} else {
@@ -485,7 +491,7 @@ func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64,
 			ls = x.rewriteSelect(leaf, w, offset+w.Type.FieldOff(fldi), regOffset+x.regOffset(w.Type, fldi))
 			if w.Op != OpIData {
 				for _, l := range ls {
-					locs = append(locs, x.f.fe.SplitStruct(l, int(selector.AuxInt)))
+					locs = append(locs, x.f.SplitStruct(l, int(selector.AuxInt)))
 				}
 			}
 		}
@@ -525,11 +531,11 @@ func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64,
 
 	case OpComplexReal:
 		ls := x.rewriteSelect(leaf, selector.Args[0], offset, regOffset)
-		locs = x.splitSlots(ls, ".real", 0, leafType)
+		locs = x.splitSlots(ls, ".real", 0, selector.Type)
 
 	case OpComplexImag:
-		ls := x.rewriteSelect(leaf, selector.Args[0], offset+leafType.Width, regOffset+RO_complex_imag) // result is FloatNN, width of result is offset of imaginary part.
-		locs = x.splitSlots(ls, ".imag", leafType.Width, leafType)
+		ls := x.rewriteSelect(leaf, selector.Args[0], offset+selector.Type.Width, regOffset+RO_complex_imag) // result is FloatNN, width of result is offset of imaginary part.
+		locs = x.splitSlots(ls, ".imag", selector.Type.Width, selector.Type)
 
 	case OpStringLen, OpSliceLen:
 		ls := x.rewriteSelect(leaf, selector.Args[0], offset+x.ptrSize, regOffset+RO_slice_len)
@@ -662,7 +668,7 @@ outer:
 func (x *expandState) decomposeArg(pos src.XPos, b *Block, source, mem *Value, t *types.Type, storeOffset int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
 
 	pa := x.prAssignForArg(source)
-	var locs []LocalSlot
+	var locs []*LocalSlot
 	for _, s := range x.namedSelects[source] {
 		locs = append(locs, x.f.Names[s.locIndex])
 	}
@@ -756,12 +762,15 @@ func (x *expandState) decomposeArg(pos src.XPos, b *Block, source, mem *Value, t
 	return nil
 }
 
-func (x *expandState) splitSlotsIntoNames(locs []LocalSlot, suffix string, off int64, rt *types.Type, w *Value) {
+func (x *expandState) splitSlotsIntoNames(locs []*LocalSlot, suffix string, off int64, rt *types.Type, w *Value) {
 	wlocs := x.splitSlots(locs, suffix, off, rt)
 	for _, l := range wlocs {
-		x.f.NamedValues[l] = append(x.f.NamedValues[l], w)
+		old, ok := x.f.NamedValues[*l]
+		x.f.NamedValues[*l] = append(old, w)
+		if !ok {
+			x.f.Names = append(x.f.Names, l)
+		}
 	}
-	x.f.Names = append(x.f.Names, wlocs...)
 }
 
 // decomposeLoad is a helper for storeArgOrLoad.
@@ -826,7 +835,7 @@ func (x *expandState) decomposeLoad(pos src.XPos, b *Block, source, mem *Value,
 // storeOneArg creates a decomposed (one step) arg that is then stored.
 // pos and b locate the store instruction, source is the "base" of the value input,
 // mem is the input mem, t is the type in question, and offArg and offStore are the offsets from the respective bases.
-func storeOneArg(x *expandState, pos src.XPos, b *Block, locs []LocalSlot, suffix string, source, mem *Value, t *types.Type, argOffset, storeOffset int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
+func storeOneArg(x *expandState, pos src.XPos, b *Block, locs []*LocalSlot, suffix string, source, mem *Value, t *types.Type, argOffset, storeOffset int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
 	if x.debug {
 		x.indent(3)
 		defer x.indent(-3)
@@ -848,7 +857,7 @@ func storeOneLoad(x *expandState, pos src.XPos, b *Block, source, mem *Value, t
 	return x.storeArgOrLoad(pos, b, w, mem, t, offStore, loadRegOffset, storeRc)
 }
 
-func storeTwoArg(x *expandState, pos src.XPos, b *Block, locs []LocalSlot, suffix1 string, suffix2 string, source, mem *Value, t1, t2 *types.Type, offArg, offStore int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
+func storeTwoArg(x *expandState, pos src.XPos, b *Block, locs []*LocalSlot, suffix1 string, suffix2 string, source, mem *Value, t1, t2 *types.Type, offArg, offStore int64, loadRegOffset Abi1RO, storeRc registerCursor) *Value {
 	mem = storeOneArg(x, pos, b, locs, suffix1, source, mem, t1, offArg, offStore, loadRegOffset, storeRc.next(t1))
 	pos = pos.WithNotStmt()
 	t1Size := t1.Size()
@@ -1168,7 +1177,7 @@ func expandCalls(f *Func) {
 	for i, name := range f.Names {
 		t := name.Type
 		if x.isAlreadyExpandedAggregateType(t) {
-			for j, v := range f.NamedValues[name] {
+			for j, v := range f.NamedValues[*name] {
 				if v.Op == OpSelectN || v.Op == OpArg && x.isAlreadyExpandedAggregateType(v.Type) {
 					ns := x.namedSelects[v]
 					x.namedSelects[v] = append(ns, namedVal{locIndex: i, valIndex: j})
@@ -1477,10 +1486,10 @@ func expandCalls(f *Func) {
 		// Leaf types may have debug locations
 		if !x.isAlreadyExpandedAggregateType(v.Type) {
 			for _, l := range locs {
-				if _, ok := f.NamedValues[l]; !ok {
+				if _, ok := f.NamedValues[*l]; !ok {
 					f.Names = append(f.Names, l)
 				}
-				f.NamedValues[l] = append(f.NamedValues[l], v)
+				f.NamedValues[*l] = append(f.NamedValues[*l], v)
 			}
 			continue
 		}
@@ -1553,7 +1562,7 @@ func expandCalls(f *Func) {
 	// Step 6: elide any copies introduced.
 	// Update named values.
 	for _, name := range f.Names {
-		values := f.NamedValues[name]
+		values := f.NamedValues[*name]
 		for i, v := range values {
 			if v.Op == OpCopy {
 				a := v.Args[0]
@@ -1714,21 +1723,6 @@ func (x *expandState) newArgToMemOrRegs(baseArg, toReplace *Value, offset int64,
 	} else {
 		w = baseArg.Block.NewValue0IA(pos, op, t, auxInt, aux)
 	}
-	// If we are creating an OpArgIntReg/OpArgFloatReg that
-	// corresponds to an in-param that fits entirely in a register,
-	// then enter it into the name/value table. The LocalSlot
-	// is somewhat fictitious, since there is no incoming live
-	// memory version of the parameter, but we need an entry in
-	// NamedValues in order for ssa debug tracking to include
-	// the value in the tracking analysis.
-	if len(pa.Registers) == 1 {
-		loc := LocalSlot{N: aux.Name, Type: t, Off: 0}
-		values, ok := x.f.NamedValues[loc]
-		if !ok {
-			x.f.Names = append(x.f.Names, loc)
-		}
-		x.f.NamedValues[loc] = append(values, w)
-	}
 	x.commonArgs[key] = w
 	if toReplace != nil {
 		toReplace.copyOf(w)
diff --git a/src/cmd/compile/internal/ssa/export_test.go b/src/cmd/compile/internal/ssa/export_test.go
index 32e6d09d1bc..6d3c0f3ccbd 100644
--- a/src/cmd/compile/internal/ssa/export_test.go
+++ b/src/cmd/compile/internal/ssa/export_test.go
@@ -39,7 +39,7 @@ func testConfigArch(tb testing.TB, arch string) *Conf {
 		tb.Fatal("testTypes is 64-bit only")
 	}
 	c := &Conf{
-		config: NewConfig(arch, testTypes, ctxt, true),
+		config: NewConfig(arch, testTypes, ctxt, true, false),
 		tb:     tb,
 	}
 	return c
@@ -73,36 +73,6 @@ func (TestFrontend) Auto(pos src.XPos, t *types.Type) *ir.Name {
 	n.Class = ir.PAUTO
 	return n
 }
-func (d TestFrontend) SplitString(s LocalSlot) (LocalSlot, LocalSlot) {
-	return LocalSlot{N: s.N, Type: testTypes.BytePtr, Off: s.Off}, LocalSlot{N: s.N, Type: testTypes.Int, Off: s.Off + 8}
-}
-func (d TestFrontend) SplitInterface(s LocalSlot) (LocalSlot, LocalSlot) {
-	return LocalSlot{N: s.N, Type: testTypes.BytePtr, Off: s.Off}, LocalSlot{N: s.N, Type: testTypes.BytePtr, Off: s.Off + 8}
-}
-func (d TestFrontend) SplitSlice(s LocalSlot) (LocalSlot, LocalSlot, LocalSlot) {
-	return LocalSlot{N: s.N, Type: s.Type.Elem().PtrTo(), Off: s.Off},
-		LocalSlot{N: s.N, Type: testTypes.Int, Off: s.Off + 8},
-		LocalSlot{N: s.N, Type: testTypes.Int, Off: s.Off + 16}
-}
-func (d TestFrontend) SplitComplex(s LocalSlot) (LocalSlot, LocalSlot) {
-	if s.Type.Size() == 16 {
-		return LocalSlot{N: s.N, Type: testTypes.Float64, Off: s.Off}, LocalSlot{N: s.N, Type: testTypes.Float64, Off: s.Off + 8}
-	}
-	return LocalSlot{N: s.N, Type: testTypes.Float32, Off: s.Off}, LocalSlot{N: s.N, Type: testTypes.Float32, Off: s.Off + 4}
-}
-func (d TestFrontend) SplitInt64(s LocalSlot) (LocalSlot, LocalSlot) {
-	if s.Type.IsSigned() {
-		return LocalSlot{N: s.N, Type: testTypes.Int32, Off: s.Off + 4}, LocalSlot{N: s.N, Type: testTypes.UInt32, Off: s.Off}
-	}
-	return LocalSlot{N: s.N, Type: testTypes.UInt32, Off: s.Off + 4}, LocalSlot{N: s.N, Type: testTypes.UInt32, Off: s.Off}
-}
-func (d TestFrontend) SplitStruct(s LocalSlot, i int) LocalSlot {
-	return LocalSlot{N: s.N, Type: s.Type.FieldType(i), Off: s.Off + s.Type.FieldOff(i)}
-}
-func (d TestFrontend) SplitArray(s LocalSlot) LocalSlot {
-	return LocalSlot{N: s.N, Type: s.Type.Elem(), Off: s.Off}
-}
-
 func (d TestFrontend) SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot {
 	return LocalSlot{N: parent.N, Type: t, Off: offset}
 }
diff --git a/src/cmd/compile/internal/ssa/flags_amd64_test.s b/src/cmd/compile/internal/ssa/flags_amd64_test.s
index 8bd87019af7..7402f6badb1 100644
--- a/src/cmd/compile/internal/ssa/flags_amd64_test.s
+++ b/src/cmd/compile/internal/ssa/flags_amd64_test.s
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64
-
 #include "textflag.h"
 
 TEXT ·asmAddFlags(SB),NOSPLIT,$0-24
diff --git a/src/cmd/compile/internal/ssa/flags_arm64_test.s b/src/cmd/compile/internal/ssa/flags_arm64_test.s
index f201bcc9943..639d7e3aedc 100644
--- a/src/cmd/compile/internal/ssa/flags_arm64_test.s
+++ b/src/cmd/compile/internal/ssa/flags_arm64_test.s
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build arm64
-
 #include "textflag.h"
 
 TEXT ·asmAddFlags(SB),NOSPLIT,$0-24
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index 378a73a95ac..fac876c23eb 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -6,6 +6,7 @@ package ssa
 
 import (
 	"cmd/compile/internal/abi"
+	"cmd/compile/internal/base"
 	"cmd/compile/internal/types"
 	"cmd/internal/src"
 	"crypto/sha1"
@@ -61,7 +62,11 @@ type Func struct {
 	NamedValues map[LocalSlot][]*Value
 	// Names is a copy of NamedValues.Keys. We keep a separate list
 	// of keys to make iteration order deterministic.
-	Names []LocalSlot
+	Names []*LocalSlot
+	// Canonicalize root/top-level local slots, and canonicalize their pieces.
+	// Because LocalSlot pieces refer to their parents with a pointer, this ensures that equivalent slots really are equal.
+	CanonicalLocalSlots  map[LocalSlot]*LocalSlot
+	CanonicalLocalSplits map[LocalSlotSplitKey]*LocalSlot
 
 	// RegArgs is a slice of register-memory pairs that must be spilled and unspilled in the uncommon path of function entry.
 	RegArgs []Spill
@@ -87,10 +92,16 @@ type Func struct {
 	constants map[int64][]*Value // constants cache, keyed by constant value; users must check value's Op and Type
 }
 
+type LocalSlotSplitKey struct {
+	parent *LocalSlot
+	Off    int64       // offset of slot in N
+	Type   *types.Type // type of slot
+}
+
 // NewFunc returns a new, empty function object.
 // Caller must set f.Config and f.Cache before using f.
 func NewFunc(fe Frontend) *Func {
-	return &Func{fe: fe, NamedValues: make(map[LocalSlot][]*Value)}
+	return &Func{fe: fe, NamedValues: make(map[LocalSlot][]*Value), CanonicalLocalSlots: make(map[LocalSlot]*LocalSlot), CanonicalLocalSplits: make(map[LocalSlotSplitKey]*LocalSlot)}
 }
 
 // NumBlocks returns an integer larger than the id of any Block in the Func.
@@ -193,6 +204,101 @@ func (f *Func) retDeadcodeLiveOrderStmts(liveOrderStmts []*Value) {
 	f.Cache.deadcode.liveOrderStmts = liveOrderStmts
 }
 
+func (f *Func) localSlotAddr(slot LocalSlot) *LocalSlot {
+	a, ok := f.CanonicalLocalSlots[slot]
+	if !ok {
+		a = new(LocalSlot)
+		*a = slot // don't escape slot
+		f.CanonicalLocalSlots[slot] = a
+	}
+	return a
+}
+
+func (f *Func) SplitString(name *LocalSlot) (*LocalSlot, *LocalSlot) {
+	ptrType := types.NewPtr(types.Types[types.TUINT8])
+	lenType := types.Types[types.TINT]
+	// Split this string up into two separate variables.
+	p := f.SplitSlot(name, ".ptr", 0, ptrType)
+	l := f.SplitSlot(name, ".len", ptrType.Size(), lenType)
+	return p, l
+}
+
+func (f *Func) SplitInterface(name *LocalSlot) (*LocalSlot, *LocalSlot) {
+	n := name.N
+	u := types.Types[types.TUINTPTR]
+	t := types.NewPtr(types.Types[types.TUINT8])
+	// Split this interface up into two separate variables.
+	sfx := ".itab"
+	if n.Type().IsEmptyInterface() {
+		sfx = ".type"
+	}
+	c := f.SplitSlot(name, sfx, 0, u) // see comment in typebits.Set
+	d := f.SplitSlot(name, ".data", u.Size(), t)
+	return c, d
+}
+
+func (f *Func) SplitSlice(name *LocalSlot) (*LocalSlot, *LocalSlot, *LocalSlot) {
+	ptrType := types.NewPtr(name.Type.Elem())
+	lenType := types.Types[types.TINT]
+	p := f.SplitSlot(name, ".ptr", 0, ptrType)
+	l := f.SplitSlot(name, ".len", ptrType.Size(), lenType)
+	c := f.SplitSlot(name, ".cap", ptrType.Size()+lenType.Size(), lenType)
+	return p, l, c
+}
+
+func (f *Func) SplitComplex(name *LocalSlot) (*LocalSlot, *LocalSlot) {
+	s := name.Type.Size() / 2
+	var t *types.Type
+	if s == 8 {
+		t = types.Types[types.TFLOAT64]
+	} else {
+		t = types.Types[types.TFLOAT32]
+	}
+	r := f.SplitSlot(name, ".real", 0, t)
+	i := f.SplitSlot(name, ".imag", t.Size(), t)
+	return r, i
+}
+
+func (f *Func) SplitInt64(name *LocalSlot) (*LocalSlot, *LocalSlot) {
+	var t *types.Type
+	if name.Type.IsSigned() {
+		t = types.Types[types.TINT32]
+	} else {
+		t = types.Types[types.TUINT32]
+	}
+	if f.Config.BigEndian {
+		return f.SplitSlot(name, ".hi", 0, t), f.SplitSlot(name, ".lo", t.Size(), types.Types[types.TUINT32])
+	}
+	return f.SplitSlot(name, ".hi", t.Size(), t), f.SplitSlot(name, ".lo", 0, types.Types[types.TUINT32])
+}
+
+func (f *Func) SplitStruct(name *LocalSlot, i int) *LocalSlot {
+	st := name.Type
+	return f.SplitSlot(name, st.FieldName(i), st.FieldOff(i), st.FieldType(i))
+}
+func (f *Func) SplitArray(name *LocalSlot) *LocalSlot {
+	n := name.N
+	at := name.Type
+	if at.NumElem() != 1 {
+		base.FatalfAt(n.Pos(), "bad array size")
+	}
+	et := at.Elem()
+	return f.SplitSlot(name, "[0]", 0, et)
+}
+
+func (f *Func) SplitSlot(name *LocalSlot, sfx string, offset int64, t *types.Type) *LocalSlot {
+	lssk := LocalSlotSplitKey{name, offset, t}
+	if als, ok := f.CanonicalLocalSplits[lssk]; ok {
+		return als
+	}
+	// Note: the _ field may appear several times.  But
+	// have no fear, identically-named but distinct Autos are
+	// ok, albeit maybe confusing for a debugger.
+	ls := f.fe.SplitSlot(name, sfx, offset, t)
+	f.CanonicalLocalSplits[lssk] = &ls
+	return &ls
+}
+
 // newValue allocates a new Value with the given fields and places it at the end of b.Values.
 func (f *Func) newValue(op Op, t *types.Type, b *Block, pos src.XPos) *Value {
 	var v *Value
diff --git a/src/cmd/compile/internal/ssa/gen/386Ops.go b/src/cmd/compile/internal/ssa/gen/386Ops.go
index c4b49fbb230..91f33c83745 100644
--- a/src/cmd/compile/internal/ssa/gen/386Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/386Ops.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index ec91ea1513b..45c02383172 100644
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -460,7 +460,7 @@
 (IsInBounds idx len) => (SETB (CMPQ idx len))
 (IsSliceInBounds idx len) => (SETBE (CMPQ idx len))
 (NilCheck ...) => (LoweredNilCheck ...)
-(GetG mem) && !(buildcfg.Experiment.RegabiG && v.Block.Func.OwnAux.Fn.ABI() == obj.ABIInternal) => (LoweredGetG mem) // only lower in old ABI. in new ABI we have a G register.
+(GetG mem) && v.Block.Func.OwnAux.Fn.ABI() != obj.ABIInternal => (LoweredGetG mem) // only lower in old ABI. in new ABI we have a G register.
 (GetClosurePtr ...) => (LoweredGetClosurePtr ...)
 (GetCallerPC ...) => (LoweredGetCallerPC ...)
 (GetCallerSP ...) => (LoweredGetCallerSP ...)
@@ -2216,3 +2216,22 @@
 (MOVOstore [dstOff] {dstSym} ptr (MOVOload [srcOff] {srcSym} (SB) _) mem) && symIsRO(srcSym) =>
   (MOVQstore [dstOff+8] {dstSym} ptr (MOVQconst [int64(read64(srcSym, int64(srcOff)+8, config.ctxt.Arch.ByteOrder))])
     (MOVQstore [dstOff] {dstSym} ptr (MOVQconst [int64(read64(srcSym, int64(srcOff), config.ctxt.Arch.ByteOrder))]) mem))
+
+// Arch-specific inlining for small or disjoint runtime.memmove
+// Match post-lowering calls, memory version.
+(SelectN [0] call:(CALLstatic {sym} s1:(MOVQstoreconst _ [sc] s2:(MOVQstore _ src s3:(MOVQstore _ dst mem)))))
+	&& sc.Val64() >= 0
+	&& isSameCall(sym, "runtime.memmove")
+	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
+	&& isInlinableMemmove(dst, src, sc.Val64(), config)
+	&& clobber(s1, s2, s3, call)
+	=> (Move [sc.Val64()] dst src mem)
+
+// Match post-lowering calls, register version.
+(SelectN [0] call:(CALLstatic {sym} dst src (MOVQconst [sz]) mem))
+	&& sz >= 0
+	&& isSameCall(sym, "runtime.memmove")
+	&& call.Uses == 1
+	&& isInlinableMemmove(dst, src, sz, config)
+	&& clobber(call)
+	=> (Move [sz] dst src mem)
diff --git a/src/cmd/compile/internal/ssa/gen/ARM64.rules b/src/cmd/compile/internal/ssa/gen/ARM64.rules
index 3d2759493e5..530e48bcb25 100644
--- a/src/cmd/compile/internal/ssa/gen/ARM64.rules
+++ b/src/cmd/compile/internal/ssa/gen/ARM64.rules
@@ -2859,3 +2859,21 @@
 (MOVHUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read16(sym, int64(off), config.ctxt.Arch.ByteOrder))])
 (MOVWUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read32(sym, int64(off), config.ctxt.Arch.ByteOrder))])
 (MOVDload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read64(sym, int64(off), config.ctxt.Arch.ByteOrder))])
+
+// Arch-specific inlining for small or disjoint runtime.memmove
+(SelectN [0] call:(CALLstatic {sym} s1:(MOVDstore _ (MOVDconst [sz]) s2:(MOVDstore  _ src s3:(MOVDstore {t} _ dst mem)))))
+	&& sz >= 0
+	&& isSameCall(sym, "runtime.memmove")
+	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
+	&& isInlinableMemmove(dst, src, sz, config)
+	&& clobber(s1, s2, s3, call)
+	=> (Move [sz] dst src mem)
+
+// Match post-lowering calls, register version.
+(SelectN [0] call:(CALLstatic {sym} dst src (MOVDconst [sz]) mem))
+	&& sz >= 0
+	&& isSameCall(sym, "runtime.memmove")
+	&& call.Uses == 1
+	&& isInlinableMemmove(dst, src, sz, config)
+	&& clobber(call)
+	=> (Move [sz] dst src mem)
diff --git a/src/cmd/compile/internal/ssa/gen/ARM64Ops.go b/src/cmd/compile/internal/ssa/gen/ARM64Ops.go
index 18a5666b40f..5de0b5f0203 100644
--- a/src/cmd/compile/internal/ssa/gen/ARM64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/ARM64Ops.go
@@ -482,9 +482,9 @@ func init() {
 		{name: "CSETM", argLength: 1, reg: readflags, asm: "CSETM", aux: "CCop"}, // auxint(flags) ? -1 : 0
 
 		// function calls
-		{name: "CALLstatic", argLength: 1, reg: regInfo{clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                                               // call static function aux.(*obj.LSym).  arg0=mem, auxint=argsize, returns mem
-		{name: "CALLclosure", argLength: 3, reg: regInfo{inputs: []regMask{gpsp, buildReg("R26"), 0}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true}, // call function via closure.  arg0=codeptr, arg1=closure, arg2=mem, auxint=argsize, returns mem
-		{name: "CALLinter", argLength: 2, reg: regInfo{inputs: []regMask{gp}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                         // call fn by pointer.  arg0=codeptr, arg1=mem, auxint=argsize, returns mem
+		{name: "CALLstatic", argLength: -1, reg: regInfo{clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                                               // call static function aux.(*obj.LSym).  last arg=mem, auxint=argsize, returns mem
+		{name: "CALLclosure", argLength: -1, reg: regInfo{inputs: []regMask{gpsp, buildReg("R26"), 0}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true}, // call function via closure.  arg0=codeptr, arg1=closure, last arg=mem, auxint=argsize, returns mem
+		{name: "CALLinter", argLength: -1, reg: regInfo{inputs: []regMask{gp}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                         // call fn by pointer.  arg0=codeptr, last arg=mem, auxint=argsize, returns mem
 
 		// pseudo-ops
 		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.
@@ -759,15 +759,17 @@ func init() {
 	}
 
 	archs = append(archs, arch{
-		name:            "ARM64",
-		pkg:             "cmd/internal/obj/arm64",
-		genfile:         "../../arm64/ssa.go",
-		ops:             ops,
-		blocks:          blocks,
-		regnames:        regNamesARM64,
-		gpregmask:       gp,
-		fpregmask:       fp,
-		framepointerreg: -1, // not used
-		linkreg:         int8(num["R30"]),
+		name:               "ARM64",
+		pkg:                "cmd/internal/obj/arm64",
+		genfile:            "../../arm64/ssa.go",
+		ops:                ops,
+		blocks:             blocks,
+		regnames:           regNamesARM64,
+		ParamIntRegNames:   "R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15",
+		ParamFloatRegNames: "F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15",
+		gpregmask:          gp,
+		fpregmask:          fp,
+		framepointerreg:    -1, // not used
+		linkreg:            int8(num["R30"]),
 	})
 }
diff --git a/src/cmd/compile/internal/ssa/gen/MIPS64Ops.go b/src/cmd/compile/internal/ssa/gen/MIPS64Ops.go
index 77f251c0d3f..a18cd4289d4 100644
--- a/src/cmd/compile/internal/ssa/gen/MIPS64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/MIPS64Ops.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/MIPSOps.go b/src/cmd/compile/internal/ssa/gen/MIPSOps.go
index b92e8cb9f1e..8177c7e2d17 100644
--- a/src/cmd/compile/internal/ssa/gen/MIPSOps.go
+++ b/src/cmd/compile/internal/ssa/gen/MIPSOps.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/PPC64Ops.go b/src/cmd/compile/internal/ssa/gen/PPC64Ops.go
index f7198b90c32..d7d8a33a0a1 100644
--- a/src/cmd/compile/internal/ssa/gen/PPC64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/PPC64Ops.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/RISCV64Ops.go b/src/cmd/compile/internal/ssa/gen/RISCV64Ops.go
index 0ac9c5f62ad..0774d4c654f 100644
--- a/src/cmd/compile/internal/ssa/gen/RISCV64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/RISCV64Ops.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/S390XOps.go b/src/cmd/compile/internal/ssa/gen/S390XOps.go
index 5b33ba710e9..00fce8e0e58 100644
--- a/src/cmd/compile/internal/ssa/gen/S390XOps.go
+++ b/src/cmd/compile/internal/ssa/gen/S390XOps.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/WasmOps.go b/src/cmd/compile/internal/ssa/gen/WasmOps.go
index c92878ca73b..7f7ae5e8370 100644
--- a/src/cmd/compile/internal/ssa/gen/WasmOps.go
+++ b/src/cmd/compile/internal/ssa/gen/WasmOps.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/dec64Ops.go b/src/cmd/compile/internal/ssa/gen/dec64Ops.go
index 8c5883bc569..78fcea885aa 100644
--- a/src/cmd/compile/internal/ssa/gen/dec64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/dec64Ops.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/decOps.go b/src/cmd/compile/internal/ssa/gen/decOps.go
index b826481c9fb..d5cd79378c7 100644
--- a/src/cmd/compile/internal/ssa/gen/decOps.go
+++ b/src/cmd/compile/internal/ssa/gen/decOps.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ignore
 // +build ignore
 
 package main
diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index aad7600d793..5cbc70cf41d 100644
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -2065,7 +2065,7 @@
 (SelectN [0] call:(StaticCall {sym} s1:(Store _ (Const(64|32) [sz]) s2:(Store  _ src s3:(Store {t} _ dst mem)))))
 	&& sz >= 0
 	&& isSameCall(sym, "runtime.memmove")
-	&& t.IsPtr() // avoids TUINTPTR, see issue 30061
+	&& t.IsPtr() // avoids TUNSAFEPTR, see issue 30061
 	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
 	&& isInlinableMemmove(dst, src, int64(sz), config)
 	&& clobber(s1, s2, s3, call)
@@ -2076,7 +2076,7 @@
 	&& sz >= 0
 	&& call.Uses == 1 // this will exclude all calls with results
 	&& isSameCall(sym, "runtime.memmove")
-	&& dst.Type.IsPtr() // avoids TUINTPTR, see issue 30061
+	&& dst.Type.IsPtr() // avoids TUNSAFEPTR, see issue 30061
 	&& isInlinableMemmove(dst, src, int64(sz), config)
 	&& clobber(call)
 	=> (Move {dst.Type.Elem()} [int64(sz)] dst src mem)
@@ -2086,7 +2086,7 @@
 	&& sz >= 0
 	&& call.Uses == 1 // this will exclude all calls with results
 	&& isSameCall(sym, "runtime.memmove")
-	&& dst.Type.IsPtr() // avoids TUINTPTR, see issue 30061
+	&& dst.Type.IsPtr() // avoids TUNSAFEPTR, see issue 30061
 	&& isInlinableMemmove(dst, src, int64(sz), config)
 	&& clobber(call)
 	=> (Move {dst.Type.Elem()} [int64(sz)] dst src mem)
diff --git a/src/cmd/compile/internal/ssa/layout.go b/src/cmd/compile/internal/ssa/layout.go
index a7fd73aead1..6abdb0d0c92 100644
--- a/src/cmd/compile/internal/ssa/layout.go
+++ b/src/cmd/compile/internal/ssa/layout.go
@@ -12,26 +12,10 @@ func layout(f *Func) {
 }
 
 // Register allocation may use a different order which has constraints
-// imposed by the linear-scan algorithm. Note that f.pass here is
-// regalloc, so the switch is conditional on -d=ssa/regalloc/test=N
+// imposed by the linear-scan algorithm.
 func layoutRegallocOrder(f *Func) []*Block {
-
-	switch f.pass.test {
-	case 0: // layout order
-		return layoutOrder(f)
-	case 1: // existing block order
-		return f.Blocks
-	case 2: // reverse of postorder; legal, but usually not good.
-		po := f.postorder()
-		visitOrder := make([]*Block, len(po))
-		for i, b := range po {
-			j := len(po) - i - 1
-			visitOrder[j] = b
-		}
-		return visitOrder
-	}
-
-	return nil
+	// remnant of an experiment; perhaps there will be another.
+	return layoutOrder(f)
 }
 
 func layoutOrder(f *Func) []*Block {
diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
index 1c37fbe0db4..df15c2edda4 100644
--- a/src/cmd/compile/internal/ssa/opGen.go
+++ b/src/cmd/compile/internal/ssa/opGen.go
@@ -20664,7 +20664,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:         "CALLstatic",
 		auxType:      auxCallOff,
-		argLen:       1,
+		argLen:       -1,
 		clobberFlags: true,
 		call:         true,
 		reg: regInfo{
@@ -20674,7 +20674,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:         "CALLclosure",
 		auxType:      auxCallOff,
-		argLen:       3,
+		argLen:       -1,
 		clobberFlags: true,
 		call:         true,
 		reg: regInfo{
@@ -20688,7 +20688,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:         "CALLinter",
 		auxType:      auxCallOff,
-		argLen:       2,
+		argLen:       -1,
 		clobberFlags: true,
 		call:         true,
 		reg: regInfo{
@@ -36400,8 +36400,8 @@ var registersARM64 = [...]Register{
 	{62, arm64.REG_F31, -1, "F31"},
 	{63, 0, -1, "SB"},
 }
-var paramIntRegARM64 = []int8(nil)
-var paramFloatRegARM64 = []int8(nil)
+var paramIntRegARM64 = []int8{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+var paramFloatRegARM64 = []int8{31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46}
 var gpRegMaskARM64 = regMask(670826495)
 var fpRegMaskARM64 = regMask(9223372034707292160)
 var specialRegMaskARM64 = regMask(0)
diff --git a/src/cmd/compile/internal/ssa/print.go b/src/cmd/compile/internal/ssa/print.go
index 36f09c3ad97..d917183c70f 100644
--- a/src/cmd/compile/internal/ssa/print.go
+++ b/src/cmd/compile/internal/ssa/print.go
@@ -154,6 +154,6 @@ func fprintFunc(p funcPrinter, f *Func) {
 		p.endBlock(b)
 	}
 	for _, name := range f.Names {
-		p.named(name, f.NamedValues[name])
+		p.named(*name, f.NamedValues[*name])
 	}
 }
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go
index c81d5574fe5..3b90b8769c2 100644
--- a/src/cmd/compile/internal/ssa/regalloc.go
+++ b/src/cmd/compile/internal/ssa/regalloc.go
@@ -1882,6 +1882,10 @@ func (s *regAllocState) placeSpills() {
 		phiRegs[b.ID] = m
 	}
 
+	mustBeFirst := func(op Op) bool {
+		return op.isLoweredGetClosurePtr() || op == OpPhi || op == OpArgIntReg || op == OpArgFloatReg
+	}
+
 	// Start maps block IDs to the list of spills
 	// that go at the start of the block (but after any phis).
 	start := map[ID][]*Value{}
@@ -1971,7 +1975,7 @@ func (s *regAllocState) placeSpills() {
 		// Put the spill in the best block we found.
 		spill.Block = best
 		spill.AddArg(bestArg)
-		if best == v.Block && v.Op != OpPhi {
+		if best == v.Block && !mustBeFirst(v.Op) {
 			// Place immediately after v.
 			after[v.ID] = append(after[v.ID], spill)
 		} else {
@@ -1983,15 +1987,15 @@ func (s *regAllocState) placeSpills() {
 	// Insert spill instructions into the block schedules.
 	var oldSched []*Value
 	for _, b := range s.visitOrder {
-		nphi := 0
+		nfirst := 0
 		for _, v := range b.Values {
-			if v.Op != OpPhi {
+			if !mustBeFirst(v.Op) {
 				break
 			}
-			nphi++
+			nfirst++
 		}
-		oldSched = append(oldSched[:0], b.Values[nphi:]...)
-		b.Values = b.Values[:nphi]
+		oldSched = append(oldSched[:0], b.Values[nfirst:]...)
+		b.Values = b.Values[:nfirst]
 		b.Values = append(b.Values, start[b.ID]...)
 		for _, v := range oldSched {
 			b.Values = append(b.Values, v)
diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index 375c4d5a560..115d5639333 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -745,27 +745,21 @@ func uaddOvf(a, b int64) bool {
 	return uint64(a)+uint64(b) < uint64(a)
 }
 
-// de-virtualize an InterCall
-// 'sym' is the symbol for the itab
-func devirt(v *Value, aux Aux, sym Sym, offset int64) *AuxCall {
-	f := v.Block.Func
-	n, ok := sym.(*obj.LSym)
-	if !ok {
+// loadLSymOffset simulates reading a word at an offset into a
+// read-only symbol's runtime memory. If it would read a pointer to
+// another symbol, that symbol is returned. Otherwise, it returns nil.
+func loadLSymOffset(lsym *obj.LSym, offset int64) *obj.LSym {
+	if lsym.Type != objabi.SRODATA {
 		return nil
 	}
-	lsym := f.fe.DerefItab(n, offset)
-	if f.pass.debug > 0 {
-		if lsym != nil {
-			f.Warnl(v.Pos, "de-virtualizing call")
-		} else {
-			f.Warnl(v.Pos, "couldn't de-virtualize call")
+
+	for _, r := range lsym.R {
+		if int64(r.Off) == offset && r.Type&^objabi.R_WEAK == objabi.R_ADDR && r.Add == 0 {
+			return r.Sym
 		}
 	}
-	if lsym == nil {
-		return nil
-	}
-	va := aux.(*AuxCall)
-	return StaticAuxCall(lsym, va.abiInfo)
+
+	return nil
 }
 
 // de-virtualize an InterLECall
@@ -776,18 +770,14 @@ func devirtLESym(v *Value, aux Aux, sym Sym, offset int64) *obj.LSym {
 		return nil
 	}
 
-	f := v.Block.Func
-	lsym := f.fe.DerefItab(n, offset)
-	if f.pass.debug > 0 {
+	lsym := loadLSymOffset(n, offset)
+	if f := v.Block.Func; f.pass.debug > 0 {
 		if lsym != nil {
 			f.Warnl(v.Pos, "de-virtualizing call")
 		} else {
 			f.Warnl(v.Pos, "couldn't de-virtualize call")
 		}
 	}
-	if lsym == nil {
-		return nil
-	}
 	return lsym
 }
 
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index efb5d271451..89d32c06572 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -3,7 +3,6 @@
 
 package ssa
 
-import "internal/buildcfg"
 import "math"
 import "cmd/internal/obj"
 import "cmd/compile/internal/types"
@@ -1038,6 +1037,8 @@ func rewriteValueAMD64(v *Value) bool {
 		return rewriteValueAMD64_OpSelect0(v)
 	case OpSelect1:
 		return rewriteValueAMD64_OpSelect1(v)
+	case OpSelectN:
+		return rewriteValueAMD64_OpSelectN(v)
 	case OpSignExt16to32:
 		v.Op = OpAMD64MOVWQSX
 		return true
@@ -29337,11 +29338,11 @@ func rewriteValueAMD64_OpFloor(v *Value) bool {
 func rewriteValueAMD64_OpGetG(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (GetG mem)
-	// cond: !(buildcfg.Experiment.RegabiG && v.Block.Func.OwnAux.Fn.ABI() == obj.ABIInternal)
+	// cond: v.Block.Func.OwnAux.Fn.ABI() != obj.ABIInternal
 	// result: (LoweredGetG mem)
 	for {
 		mem := v_0
-		if !(!(buildcfg.Experiment.RegabiG && v.Block.Func.OwnAux.Fn.ABI() == obj.ABIInternal)) {
+		if !(v.Block.Func.OwnAux.Fn.ABI() != obj.ABIInternal) {
 			break
 		}
 		v.reset(OpAMD64LoweredGetG)
@@ -32981,6 +32982,78 @@ func rewriteValueAMD64_OpSelect1(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueAMD64_OpSelectN(v *Value) bool {
+	v_0 := v.Args[0]
+	b := v.Block
+	config := b.Func.Config
+	// match: (SelectN [0] call:(CALLstatic {sym} s1:(MOVQstoreconst _ [sc] s2:(MOVQstore _ src s3:(MOVQstore _ dst mem)))))
+	// cond: sc.Val64() >= 0 && isSameCall(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sc.Val64(), config) && clobber(s1, s2, s3, call)
+	// result: (Move [sc.Val64()] dst src mem)
+	for {
+		if auxIntToInt64(v.AuxInt) != 0 {
+			break
+		}
+		call := v_0
+		if call.Op != OpAMD64CALLstatic || len(call.Args) != 1 {
+			break
+		}
+		sym := auxToCall(call.Aux)
+		s1 := call.Args[0]
+		if s1.Op != OpAMD64MOVQstoreconst {
+			break
+		}
+		sc := auxIntToValAndOff(s1.AuxInt)
+		_ = s1.Args[1]
+		s2 := s1.Args[1]
+		if s2.Op != OpAMD64MOVQstore {
+			break
+		}
+		_ = s2.Args[2]
+		src := s2.Args[1]
+		s3 := s2.Args[2]
+		if s3.Op != OpAMD64MOVQstore {
+			break
+		}
+		mem := s3.Args[2]
+		dst := s3.Args[1]
+		if !(sc.Val64() >= 0 && isSameCall(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sc.Val64(), config) && clobber(s1, s2, s3, call)) {
+			break
+		}
+		v.reset(OpMove)
+		v.AuxInt = int64ToAuxInt(sc.Val64())
+		v.AddArg3(dst, src, mem)
+		return true
+	}
+	// match: (SelectN [0] call:(CALLstatic {sym} dst src (MOVQconst [sz]) mem))
+	// cond: sz >= 0 && isSameCall(sym, "runtime.memmove") && call.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(call)
+	// result: (Move [sz] dst src mem)
+	for {
+		if auxIntToInt64(v.AuxInt) != 0 {
+			break
+		}
+		call := v_0
+		if call.Op != OpAMD64CALLstatic || len(call.Args) != 4 {
+			break
+		}
+		sym := auxToCall(call.Aux)
+		mem := call.Args[3]
+		dst := call.Args[0]
+		src := call.Args[1]
+		call_2 := call.Args[2]
+		if call_2.Op != OpAMD64MOVQconst {
+			break
+		}
+		sz := auxIntToInt64(call_2.AuxInt)
+		if !(sz >= 0 && isSameCall(sym, "runtime.memmove") && call.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(call)) {
+			break
+		}
+		v.reset(OpMove)
+		v.AuxInt = int64ToAuxInt(sz)
+		v.AddArg3(dst, src, mem)
+		return true
+	}
+	return false
+}
 func rewriteValueAMD64_OpSlicemask(v *Value) bool {
 	v_0 := v.Args[0]
 	b := v.Block
diff --git a/src/cmd/compile/internal/ssa/rewriteARM64.go b/src/cmd/compile/internal/ssa/rewriteARM64.go
index 0ba3951df57..f7840c55039 100644
--- a/src/cmd/compile/internal/ssa/rewriteARM64.go
+++ b/src/cmd/compile/internal/ssa/rewriteARM64.go
@@ -984,6 +984,8 @@ func rewriteValueARM64(v *Value) bool {
 		return rewriteValueARM64_OpSelect0(v)
 	case OpSelect1:
 		return rewriteValueARM64_OpSelect1(v)
+	case OpSelectN:
+		return rewriteValueARM64_OpSelectN(v)
 	case OpSignExt16to32:
 		v.Op = OpARM64MOVHreg
 		return true
@@ -25983,6 +25985,82 @@ func rewriteValueARM64_OpSelect1(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueARM64_OpSelectN(v *Value) bool {
+	v_0 := v.Args[0]
+	b := v.Block
+	config := b.Func.Config
+	// match: (SelectN [0] call:(CALLstatic {sym} s1:(MOVDstore _ (MOVDconst [sz]) s2:(MOVDstore _ src s3:(MOVDstore {t} _ dst mem)))))
+	// cond: sz >= 0 && isSameCall(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1, s2, s3, call)
+	// result: (Move [sz] dst src mem)
+	for {
+		if auxIntToInt64(v.AuxInt) != 0 {
+			break
+		}
+		call := v_0
+		if call.Op != OpARM64CALLstatic || len(call.Args) != 1 {
+			break
+		}
+		sym := auxToCall(call.Aux)
+		s1 := call.Args[0]
+		if s1.Op != OpARM64MOVDstore {
+			break
+		}
+		_ = s1.Args[2]
+		s1_1 := s1.Args[1]
+		if s1_1.Op != OpARM64MOVDconst {
+			break
+		}
+		sz := auxIntToInt64(s1_1.AuxInt)
+		s2 := s1.Args[2]
+		if s2.Op != OpARM64MOVDstore {
+			break
+		}
+		_ = s2.Args[2]
+		src := s2.Args[1]
+		s3 := s2.Args[2]
+		if s3.Op != OpARM64MOVDstore {
+			break
+		}
+		mem := s3.Args[2]
+		dst := s3.Args[1]
+		if !(sz >= 0 && isSameCall(sym, "runtime.memmove") && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(s1, s2, s3, call)) {
+			break
+		}
+		v.reset(OpMove)
+		v.AuxInt = int64ToAuxInt(sz)
+		v.AddArg3(dst, src, mem)
+		return true
+	}
+	// match: (SelectN [0] call:(CALLstatic {sym} dst src (MOVDconst [sz]) mem))
+	// cond: sz >= 0 && isSameCall(sym, "runtime.memmove") && call.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(call)
+	// result: (Move [sz] dst src mem)
+	for {
+		if auxIntToInt64(v.AuxInt) != 0 {
+			break
+		}
+		call := v_0
+		if call.Op != OpARM64CALLstatic || len(call.Args) != 4 {
+			break
+		}
+		sym := auxToCall(call.Aux)
+		mem := call.Args[3]
+		dst := call.Args[0]
+		src := call.Args[1]
+		call_2 := call.Args[2]
+		if call_2.Op != OpARM64MOVDconst {
+			break
+		}
+		sz := auxIntToInt64(call_2.AuxInt)
+		if !(sz >= 0 && isSameCall(sym, "runtime.memmove") && call.Uses == 1 && isInlinableMemmove(dst, src, sz, config) && clobber(call)) {
+			break
+		}
+		v.reset(OpMove)
+		v.AuxInt = int64ToAuxInt(sz)
+		v.AddArg3(dst, src, mem)
+		return true
+	}
+	return false
+}
 func rewriteValueARM64_OpSlicemask(v *Value) bool {
 	v_0 := v.Args[0]
 	b := v.Block
diff --git a/src/cmd/compile/internal/ssa/schedule.go b/src/cmd/compile/internal/ssa/schedule.go
index 4e3e5e75e35..c5130b2ee50 100644
--- a/src/cmd/compile/internal/ssa/schedule.go
+++ b/src/cmd/compile/internal/ssa/schedule.go
@@ -220,7 +220,7 @@ func schedule(f *Func) {
 			// unless they are phi values (which must be first).
 			// OpArg also goes first -- if it is stack it register allocates
 			// to a LoadReg, if it is register it is from the beginning anyway.
-			if c.Op == OpPhi || c.Op == OpArg {
+			if score[c.ID] == ScorePhi || score[c.ID] == ScoreArg {
 				continue
 			}
 			score[c.ID] = ScoreControl
diff --git a/src/cmd/compile/internal/ssa/softfloat.go b/src/cmd/compile/internal/ssa/softfloat.go
index a8a8f836294..351f824a9f5 100644
--- a/src/cmd/compile/internal/ssa/softfloat.go
+++ b/src/cmd/compile/internal/ssa/softfloat.go
@@ -63,6 +63,7 @@ func softfloat(f *Func) {
 					v.Aux = f.Config.Types.UInt32
 				case 8:
 					v.Aux = f.Config.Types.UInt64
+					newInt64 = true
 				default:
 					v.Fatalf("bad float type with size %d", size)
 				}
diff --git a/src/cmd/compile/internal/ssa/stackalloc.go b/src/cmd/compile/internal/ssa/stackalloc.go
index d9625791226..d41f3996af7 100644
--- a/src/cmd/compile/internal/ssa/stackalloc.go
+++ b/src/cmd/compile/internal/ssa/stackalloc.go
@@ -141,10 +141,11 @@ func (s *stackAllocState) stackalloc() {
 		s.names = make([]LocalSlot, n)
 	}
 	names := s.names
+	empty := LocalSlot{}
 	for _, name := range f.Names {
 		// Note: not "range f.NamedValues" above, because
 		// that would be nondeterministic.
-		for _, v := range f.NamedValues[name] {
+		for _, v := range f.NamedValues[*name] {
 			if v.Op == OpArgIntReg || v.Op == OpArgFloatReg {
 				aux := v.Aux.(*AuxNameOffset)
 				// Never let an arg be bound to a differently named thing.
@@ -162,10 +163,12 @@ func (s *stackAllocState) stackalloc() {
 				continue
 			}
 
-			if f.pass.debug > stackDebug {
-				fmt.Printf("stackalloc value %s to name %s\n", v, name)
+			if names[v.ID] == empty {
+				if f.pass.debug > stackDebug {
+					fmt.Printf("stackalloc value %s to name %s\n", v, *name)
+				}
+				names[v.ID] = *name
 			}
-			names[v.ID] = name
 		}
 	}
 
diff --git a/src/cmd/compile/internal/ssagen/abi.go b/src/cmd/compile/internal/ssagen/abi.go
index e460adaf95d..6d8c53e7225 100644
--- a/src/cmd/compile/internal/ssagen/abi.go
+++ b/src/cmd/compile/internal/ssagen/abi.go
@@ -152,6 +152,9 @@ func (s *SymABIs) GenABIWrappers() {
 		// Apply definitions.
 		defABI, hasDefABI := s.defs[symName]
 		if hasDefABI {
+			if len(fn.Body) != 0 {
+				base.ErrorfAt(fn.Pos(), "%v defined in both Go and assembly", fn)
+			}
 			fn.ABI = defABI
 		}
 
diff --git a/src/cmd/compile/internal/ssagen/arch.go b/src/cmd/compile/internal/ssagen/arch.go
index 7215f42c059..483e45cad43 100644
--- a/src/cmd/compile/internal/ssagen/arch.go
+++ b/src/cmd/compile/internal/ssagen/arch.go
@@ -29,8 +29,7 @@ type ArchInfo struct {
 	// at function entry, and it is ok to clobber registers.
 	ZeroRange func(*objw.Progs, *obj.Prog, int64, int64, *uint32) *obj.Prog
 
-	Ginsnop      func(*objw.Progs) *obj.Prog
-	Ginsnopdefer func(*objw.Progs) *obj.Prog // special ginsnop for deferreturn
+	Ginsnop func(*objw.Progs) *obj.Prog
 
 	// SSAMarkMoves marks any MOVXconst ops that need to avoid clobbering flags.
 	SSAMarkMoves func(*State, *ssa.Block)
@@ -42,10 +41,10 @@ type ArchInfo struct {
 	// for all values in the block before SSAGenBlock.
 	SSAGenBlock func(s *State, b, next *ssa.Block)
 
-	// LoadRegResults emits instructions that loads register-assigned results
-	// into registers. They are already in memory (PPARAMOUT nodes).
-	// Used in open-coded defer return path.
-	LoadRegResults func(s *State, f *ssa.Func)
+	// LoadRegResult emits instructions that loads register-assigned result
+	// at n+off (n is PPARAMOUT) to register reg. The result is already in
+	// memory. Used in open-coded defer return path.
+	LoadRegResult func(s *State, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog
 
 	// SpillArgReg emits instructions that spill reg to n+off.
 	SpillArgReg func(pp *objw.Progs, p *obj.Prog, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog
diff --git a/src/cmd/compile/internal/ssagen/pgen.go b/src/cmd/compile/internal/ssagen/pgen.go
index 62567535d76..93157bfa11b 100644
--- a/src/cmd/compile/internal/ssagen/pgen.go
+++ b/src/cmd/compile/internal/ssagen/pgen.go
@@ -114,7 +114,10 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
 		}
 	}
 
-	sort.Sort(byStackVar(fn.Dcl))
+	// Use sort.Stable instead of sort.Sort so stack layout (and thus
+	// compiler output) is less sensitive to frontend changes that
+	// introduce or remove unused variables.
+	sort.Stable(byStackVar(fn.Dcl))
 
 	// Reassign stack offsets of the locals that are used.
 	lastHasPtr := false
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 2abd70169e6..b0f2585e3ab 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -8,7 +8,6 @@ import (
 	"bufio"
 	"bytes"
 	"cmd/compile/internal/abi"
-	"encoding/binary"
 	"fmt"
 	"go/constant"
 	"html"
@@ -88,8 +87,7 @@ func InitConfig() {
 	_ = types.NewPtr(types.Types[types.TINT64])                             // *int64
 	_ = types.NewPtr(types.ErrorType)                                       // *error
 	types.NewPtrCacheEnabled = false
-	ssaConfig = ssa.NewConfig(base.Ctxt.Arch.Name, *types_, base.Ctxt, base.Flag.N == 0)
-	ssaConfig.SoftFloat = Arch.SoftFloat
+	ssaConfig = ssa.NewConfig(base.Ctxt.Arch.Name, *types_, base.Ctxt, base.Flag.N == 0, Arch.SoftFloat)
 	ssaConfig.Race = base.Flag.Race
 	ssaCaches = make([]ssa.Cache, base.Flag.LowerC)
 
@@ -280,18 +278,6 @@ func regAbiForFuncType(ft *types.Func) bool {
 	return np > 0 && strings.Contains(ft.Params.FieldType(np-1).String(), magicLastTypeName)
 }
 
-// getParam returns the Field of ith param of node n (which is a
-// function/method/interface call), where the receiver of a method call is
-// considered as the 0th parameter. This does not include the receiver of an
-// interface call.
-func getParam(n *ir.CallExpr, i int) *types.Field {
-	t := n.X.Type()
-	if n.Op() == ir.OCALLMETH {
-		base.Fatalf("OCALLMETH missed by walkCall")
-	}
-	return t.Params().Field(i)
-}
-
 // dvarint writes a varint v to the funcdata in symbol x and returns the new offset
 func dvarint(x *obj.LSym, off int, v int64) int {
 	if v < 0 || v > 1e9 {
@@ -325,66 +311,21 @@ func dvarint(x *obj.LSym, off int, v int64) int {
 // for stack variables are specified as the number of bytes below varp (pointer to the
 // top of the local variables) for their starting address. The format is:
 //
-//  - Max total argument size among all the defers
 //  - Offset of the deferBits variable
 //  - Number of defers in the function
 //  - Information about each defer call, in reverse order of appearance in the function:
-//    - Total argument size of the call
 //    - Offset of the closure value to call
-//    - Number of arguments (including interface receiver or method receiver as first arg)
-//    - Information about each argument
-//      - Offset of the stored defer argument in this function's frame
-//      - Size of the argument
-//      - Offset of where argument should be placed in the args frame when making call
 func (s *state) emitOpenDeferInfo() {
 	x := base.Ctxt.Lookup(s.curfn.LSym.Name + ".opendefer")
 	s.curfn.LSym.Func().OpenCodedDeferInfo = x
 	off := 0
-
-	// Compute maxargsize (max size of arguments for all defers)
-	// first, so we can output it first to the funcdata
-	var maxargsize int64
-	for i := len(s.openDefers) - 1; i >= 0; i-- {
-		r := s.openDefers[i]
-		argsize := r.n.X.Type().ArgWidth() // TODO register args: but maybe use of abi0 will make this easy
-		if argsize > maxargsize {
-			maxargsize = argsize
-		}
-	}
-	off = dvarint(x, off, maxargsize)
 	off = dvarint(x, off, -s.deferBitsTemp.FrameOffset())
 	off = dvarint(x, off, int64(len(s.openDefers)))
 
 	// Write in reverse-order, for ease of running in that order at runtime
 	for i := len(s.openDefers) - 1; i >= 0; i-- {
 		r := s.openDefers[i]
-		off = dvarint(x, off, r.n.X.Type().ArgWidth())
 		off = dvarint(x, off, -r.closureNode.FrameOffset())
-		numArgs := len(r.argNodes)
-		if r.rcvrNode != nil {
-			// If there's an interface receiver, treat/place it as the first
-			// arg. (If there is a method receiver, it's already included as
-			// first arg in r.argNodes.)
-			numArgs++
-		}
-		off = dvarint(x, off, int64(numArgs))
-		argAdjust := 0 // presence of receiver offsets the parameter count.
-		if r.rcvrNode != nil {
-			off = dvarint(x, off, -okOffset(r.rcvrNode.FrameOffset()))
-			off = dvarint(x, off, s.config.PtrSize)
-			off = dvarint(x, off, 0) // This is okay because defer records use ABI0 (for now)
-			argAdjust++
-		}
-
-		// TODO(register args) assume abi0 for this?
-		ab := s.f.ABI0
-		pri := ab.ABIAnalyzeFuncType(r.n.X.Type().FuncType())
-		for j, arg := range r.argNodes {
-			f := getParam(r.n, j)
-			off = dvarint(x, off, -okOffset(arg.FrameOffset()))
-			off = dvarint(x, off, f.Type.Size())
-			off = dvarint(x, off, okOffset(pri.InParam(j+argAdjust).FrameOffset(pri)))
-		}
 	}
 }
 
@@ -581,7 +522,7 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 	}
 
 	// Populate closure variables.
-	if !fn.ClosureCalled() {
+	if fn.Needctxt() {
 		clo := s.entryNewValue0(ssa.OpGetClosurePtr, s.f.Config.Types.BytePtr)
 		offset := int64(types.PtrSize) // PtrSize to skip past function entry PC field
 		for _, n := range fn.ClosureVars {
@@ -651,7 +592,6 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 	// it mimics the behavior of the former ABI (everything stored) and because it's not 100%
 	// clear if naming conventions are respected in autogenerated code.
 	// TODO figure out exactly what's unused, don't spill it. Make liveness fine-grained, also.
-	// TODO non-amd64 architectures have link registers etc that may require adjustment here.
 	for _, p := range params.InParams() {
 		typs, offs := p.RegisterTypesAndOffsets()
 		for i, t := range typs {
@@ -866,16 +806,6 @@ type openDeferInfo struct {
 	// function, method, or interface call, to store a closure that panic
 	// processing can use for this defer.
 	closureNode *ir.Name
-	// If defer call is interface call, the address of the argtmp where the
-	// receiver is stored
-	rcvr *ssa.Value
-	// The node representing the argtmp where the receiver is stored
-	rcvrNode *ir.Name
-	// The addresses of the argtmps where the evaluated arguments of the defer
-	// function call are stored.
-	argVals []*ssa.Value
-	// The nodes representing the argtmps where the args of the defer are stored
-	argNodes []*ir.Name
 }
 
 type state struct {
@@ -1297,7 +1227,7 @@ func (s *state) instrumentFields(t *types.Type, addr *ssa.Value, kind instrument
 		if f.Sym.IsBlank() {
 			continue
 		}
-		offptr := s.newValue1I(ssa.OpOffPtr, types.NewPtr(f.Type), abi.FieldOffsetOf(f), addr)
+		offptr := s.newValue1I(ssa.OpOffPtr, types.NewPtr(f.Type), f.Offset, addr)
 		s.instrumentFields(f.Type, offptr, kind)
 	}
 }
@@ -1492,7 +1422,12 @@ func (s *state) stmt(n ir.Node) {
 
 	case ir.OAS2DOTTYPE:
 		n := n.(*ir.AssignListStmt)
-		res, resok := s.dottype(n.Rhs[0].(*ir.TypeAssertExpr), true)
+		var res, resok *ssa.Value
+		if n.Rhs[0].Op() == ir.ODOTTYPE2 {
+			res, resok = s.dottype(n.Rhs[0].(*ir.TypeAssertExpr), true)
+		} else {
+			res, resok = s.dynamicDottype(n.Rhs[0].(*ir.DynamicTypeAssertExpr), true)
+		}
 		deref := false
 		if !TypeOK(n.Rhs[0].Type()) {
 			if res.Op != ssa.OpLoad {
@@ -2749,6 +2684,11 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		res, _ := s.dottype(n, false)
 		return res
 
+	case ir.ODYNAMICDOTTYPE:
+		n := n.(*ir.DynamicTypeAssertExpr)
+		res, _ := s.dynamicDottype(n, false)
+		return res
+
 	// binary ops
 	case ir.OLT, ir.OEQ, ir.ONE, ir.OLE, ir.OGE, ir.OGT:
 		n := n.(*ir.BinaryExpr)
@@ -3175,7 +3115,7 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		arrlen := s.constInt(types.Types[types.TINT], n.Type().Elem().NumElem())
 		cap := s.newValue1(ssa.OpSliceLen, types.Types[types.TINT], v)
 		s.boundsCheck(arrlen, cap, ssa.BoundsConvert, false)
-		return s.newValue1(ssa.OpSlicePtrUnchecked, types.Types[types.TINT], v)
+		return s.newValue1(ssa.OpSlicePtrUnchecked, n.Type(), v)
 
 	case ir.OCALLFUNC:
 		n := n.(*ir.CallExpr)
@@ -3184,7 +3124,7 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		}
 		fallthrough
 
-	case ir.OCALLINTER, ir.OCALLMETH:
+	case ir.OCALLINTER:
 		n := n.(*ir.CallExpr)
 		return s.callResult(n, callNormal)
 
@@ -3192,6 +3132,14 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		n := n.(*ir.CallExpr)
 		return s.newValue1(ssa.OpGetG, n.Type(), s.mem())
 
+	case ir.OGETCALLERPC:
+		n := n.(*ir.CallExpr)
+		return s.newValue0(ssa.OpGetCallerPC, n.Type())
+
+	case ir.OGETCALLERSP:
+		n := n.(*ir.CallExpr)
+		return s.newValue0(ssa.OpGetCallerSP, n.Type())
+
 	case ir.OAPPEND:
 		return s.append(n.(*ir.CallExpr), false)
 
@@ -3704,6 +3652,16 @@ func softfloatInit() {
 // TODO: do not emit sfcall if operation can be optimized to constant in later
 // opt phase
 func (s *state) sfcall(op ssa.Op, args ...*ssa.Value) (*ssa.Value, bool) {
+	f2i := func(t *types.Type) *types.Type {
+		switch t.Kind() {
+		case types.TFLOAT32:
+			return types.Types[types.TUINT32]
+		case types.TFLOAT64:
+			return types.Types[types.TUINT64]
+		}
+		return t
+	}
+
 	if callDef, ok := softFloatOps[op]; ok {
 		switch op {
 		case ssa.OpLess32F,
@@ -3716,7 +3674,19 @@ func (s *state) sfcall(op ssa.Op, args ...*ssa.Value) (*ssa.Value, bool) {
 			args[1] = s.newValue1(s.ssaOp(ir.ONEG, types.Types[callDef.rtype]), args[1].Type, args[1])
 		}
 
-		result := s.rtcall(callDef.rtfn, true, []*types.Type{types.Types[callDef.rtype]}, args...)[0]
+		// runtime functions take uints for floats and returns uints.
+		// Convert to uints so we use the right calling convention.
+		for i, a := range args {
+			if a.Type.IsFloat() {
+				args[i] = s.newValue1(ssa.OpCopy, f2i(a.Type), a)
+			}
+		}
+
+		rt := types.Types[callDef.rtype]
+		result := s.rtcall(callDef.rtfn, true, []*types.Type{f2i(rt)}, args...)[0]
+		if rt.IsFloat() {
+			result = s.newValue1(ssa.OpCopy, rt, result)
+		}
 		if op == ssa.OpNeq32F || op == ssa.OpNeq64F {
 			result = s.newValue1(ssa.OpNot, result.Type, result)
 		}
@@ -4688,17 +4658,14 @@ func (s *state) intrinsicArgs(n *ir.CallExpr) []*ssa.Value {
 	return args
 }
 
-// openDeferRecord adds code to evaluate and store the args for an open-code defer
+// openDeferRecord adds code to evaluate and store the function for an open-code defer
 // call, and records info about the defer, so we can generate proper code on the
 // exit paths. n is the sub-node of the defer node that is the actual function
-// call. We will also record funcdata information on where the args are stored
+// call. We will also record funcdata information on where the function is stored
 // (as well as the deferBits variable), and this will enable us to run the proper
 // defer calls during panics.
 func (s *state) openDeferRecord(n *ir.CallExpr) {
-	var args []*ssa.Value
-	var argNodes []*ir.Name
-
-	if buildcfg.Experiment.RegabiDefer && (len(n.Args) != 0 || n.Op() == ir.OCALLINTER || n.X.Type().NumResults() != 0) {
+	if len(n.Args) != 0 || n.Op() != ir.OCALLFUNC || n.X.Type().NumResults() != 0 {
 		s.Fatalf("defer call with arguments or results: %v", n)
 	}
 
@@ -4706,48 +4673,20 @@ func (s *state) openDeferRecord(n *ir.CallExpr) {
 		n: n,
 	}
 	fn := n.X
-	if n.Op() == ir.OCALLFUNC {
-		// We must always store the function value in a stack slot for the
-		// runtime panic code to use. But in the defer exit code, we will
-		// call the function directly if it is a static function.
-		closureVal := s.expr(fn)
-		closure := s.openDeferSave(nil, fn.Type(), closureVal)
-		opendefer.closureNode = closure.Aux.(*ir.Name)
-		if !(fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC) {
-			opendefer.closure = closure
-		}
-	} else if n.Op() == ir.OCALLMETH {
-		base.Fatalf("OCALLMETH missed by walkCall")
-	} else {
-		if fn.Op() != ir.ODOTINTER {
-			base.Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", fn.Op())
-		}
-		fn := fn.(*ir.SelectorExpr)
-		closure, rcvr := s.getClosureAndRcvr(fn)
-		opendefer.closure = s.openDeferSave(nil, closure.Type, closure)
-		// Important to get the receiver type correct, so it is recognized
-		// as a pointer for GC purposes.
-		opendefer.rcvr = s.openDeferSave(nil, fn.Type().Recv().Type, rcvr)
-		opendefer.closureNode = opendefer.closure.Aux.(*ir.Name)
-		opendefer.rcvrNode = opendefer.rcvr.Aux.(*ir.Name)
+	// We must always store the function value in a stack slot for the
+	// runtime panic code to use. But in the defer exit code, we will
+	// call the function directly if it is a static function.
+	closureVal := s.expr(fn)
+	closure := s.openDeferSave(fn.Type(), closureVal)
+	opendefer.closureNode = closure.Aux.(*ir.Name)
+	if !(fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC) {
+		opendefer.closure = closure
 	}
-	for _, argn := range n.Args {
-		var v *ssa.Value
-		if TypeOK(argn.Type()) {
-			v = s.openDeferSave(nil, argn.Type(), s.expr(argn))
-		} else {
-			v = s.openDeferSave(argn, argn.Type(), nil)
-		}
-		args = append(args, v)
-		argNodes = append(argNodes, v.Aux.(*ir.Name))
-	}
-	opendefer.argVals = args
-	opendefer.argNodes = argNodes
 	index := len(s.openDefers)
 	s.openDefers = append(s.openDefers, opendefer)
 
 	// Update deferBits only after evaluation and storage to stack of
-	// args/receiver/interface is successful.
+	// the function is successful.
 	bitvalue := s.constInt8(types.Types[types.TUINT8], 1< 0 {
-				base.WarnfAt(n.Pos(), "type assertion inlined")
+				base.WarnfAt(pos, "type assertion inlined")
 			}
 
 			// Get itab/type field from input.
@@ -6223,7 +6117,7 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 			// Conversion succeeds iff that field is not nil.
 			cond := s.newValue2(ssa.OpNeqPtr, types.Types[types.TBOOL], itab, s.constNil(byteptr))
 
-			if n.X.Type().IsEmptyInterface() && commaok {
+			if src.IsEmptyInterface() && commaok {
 				// Converting empty interface to empty interface with ,ok is just a nil check.
 				return iface, cond
 			}
@@ -6245,7 +6139,7 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 
 				// On success, return (perhaps modified) input interface.
 				s.startBlock(bOk)
-				if n.X.Type().IsEmptyInterface() {
+				if src.IsEmptyInterface() {
 					res = iface // Use input interface unchanged.
 					return
 				}
@@ -6253,7 +6147,7 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 				off := s.newValue1I(ssa.OpOffPtr, byteptr, int64(types.PtrSize), itab)
 				typ := s.load(byteptr, off)
 				idata := s.newValue1(ssa.OpIData, byteptr, iface)
-				res = s.newValue2(ssa.OpIMake, n.Type(), typ, idata)
+				res = s.newValue2(ssa.OpIMake, dst, typ, idata)
 				return
 			}
 
@@ -6275,62 +6169,62 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 			bFail.AddEdgeTo(bEnd)
 			s.startBlock(bEnd)
 			idata := s.newValue1(ssa.OpIData, byteptr, iface)
-			res = s.newValue2(ssa.OpIMake, n.Type(), s.variable(typVar, byteptr), idata)
+			res = s.newValue2(ssa.OpIMake, dst, s.variable(typVar, byteptr), idata)
 			resok = cond
 			delete(s.vars, typVar)
 			return
 		}
 		// converting to a nonempty interface needs a runtime call.
 		if base.Debug.TypeAssert > 0 {
-			base.WarnfAt(n.Pos(), "type assertion not inlined")
+			base.WarnfAt(pos, "type assertion not inlined")
 		}
 		if !commaok {
 			fn := ir.Syms.AssertI2I
-			if n.X.Type().IsEmptyInterface() {
+			if src.IsEmptyInterface() {
 				fn = ir.Syms.AssertE2I
 			}
 			data := s.newValue1(ssa.OpIData, types.Types[types.TUNSAFEPTR], iface)
 			tab := s.newValue1(ssa.OpITab, byteptr, iface)
 			tab = s.rtcall(fn, true, []*types.Type{byteptr}, target, tab)[0]
-			return s.newValue2(ssa.OpIMake, n.Type(), tab, data), nil
+			return s.newValue2(ssa.OpIMake, dst, tab, data), nil
 		}
 		fn := ir.Syms.AssertI2I2
-		if n.X.Type().IsEmptyInterface() {
+		if src.IsEmptyInterface() {
 			fn = ir.Syms.AssertE2I2
 		}
-		res = s.rtcall(fn, true, []*types.Type{n.Type()}, target, iface)[0]
-		resok = s.newValue2(ssa.OpNeqInter, types.Types[types.TBOOL], res, s.constInterface(n.Type()))
+		res = s.rtcall(fn, true, []*types.Type{dst}, target, iface)[0]
+		resok = s.newValue2(ssa.OpNeqInter, types.Types[types.TBOOL], res, s.constInterface(dst))
 		return
 	}
 
 	if base.Debug.TypeAssert > 0 {
-		base.WarnfAt(n.Pos(), "type assertion inlined")
+		base.WarnfAt(pos, "type assertion inlined")
 	}
 
 	// Converting to a concrete type.
-	direct := types.IsDirectIface(n.Type())
+	direct := types.IsDirectIface(dst)
 	itab := s.newValue1(ssa.OpITab, byteptr, iface) // type word of interface
 	if base.Debug.TypeAssert > 0 {
-		base.WarnfAt(n.Pos(), "type assertion inlined")
+		base.WarnfAt(pos, "type assertion inlined")
 	}
-	var targetITab *ssa.Value
-	if n.X.Type().IsEmptyInterface() {
+	var wantedFirstWord *ssa.Value
+	if src.IsEmptyInterface() {
 		// Looking for pointer to target type.
-		targetITab = target
+		wantedFirstWord = target
 	} else {
 		// Looking for pointer to itab for target type and source interface.
-		targetITab = s.expr(n.Itab)
+		wantedFirstWord = targetItab
 	}
 
 	var tmp ir.Node     // temporary for use with large types
 	var addr *ssa.Value // address of tmp
-	if commaok && !TypeOK(n.Type()) {
+	if commaok && !TypeOK(dst) {
 		// unSSAable type, use temporary.
 		// TODO: get rid of some of these temporaries.
-		tmp, addr = s.temp(n.Pos(), n.Type())
+		tmp, addr = s.temp(pos, dst)
 	}
 
-	cond := s.newValue2(ssa.OpEqPtr, types.Types[types.TBOOL], itab, targetITab)
+	cond := s.newValue2(ssa.OpEqPtr, types.Types[types.TBOOL], itab, wantedFirstWord)
 	b := s.endBlock()
 	b.Kind = ssa.BlockIf
 	b.SetControl(cond)
@@ -6344,8 +6238,8 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 	if !commaok {
 		// on failure, panic by calling panicdottype
 		s.startBlock(bFail)
-		taddr := s.reflectType(n.X.Type())
-		if n.X.Type().IsEmptyInterface() {
+		taddr := s.reflectType(src)
+		if src.IsEmptyInterface() {
 			s.rtcall(ir.Syms.PanicdottypeE, false, nil, itab, target, taddr)
 		} else {
 			s.rtcall(ir.Syms.PanicdottypeI, false, nil, itab, target, taddr)
@@ -6354,10 +6248,10 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 		// on success, return data from interface
 		s.startBlock(bOk)
 		if direct {
-			return s.newValue1(ssa.OpIData, n.Type(), iface), nil
+			return s.newValue1(ssa.OpIData, dst, iface), nil
 		}
-		p := s.newValue1(ssa.OpIData, types.NewPtr(n.Type()), iface)
-		return s.load(n.Type(), p), nil
+		p := s.newValue1(ssa.OpIData, types.NewPtr(dst), iface)
+		return s.load(dst, p), nil
 	}
 
 	// commaok is the more complicated case because we have
@@ -6371,14 +6265,14 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 	s.startBlock(bOk)
 	if tmp == nil {
 		if direct {
-			s.vars[valVar] = s.newValue1(ssa.OpIData, n.Type(), iface)
+			s.vars[valVar] = s.newValue1(ssa.OpIData, dst, iface)
 		} else {
-			p := s.newValue1(ssa.OpIData, types.NewPtr(n.Type()), iface)
-			s.vars[valVar] = s.load(n.Type(), p)
+			p := s.newValue1(ssa.OpIData, types.NewPtr(dst), iface)
+			s.vars[valVar] = s.load(dst, p)
 		}
 	} else {
-		p := s.newValue1(ssa.OpIData, types.NewPtr(n.Type()), iface)
-		s.move(n.Type(), addr, p)
+		p := s.newValue1(ssa.OpIData, types.NewPtr(dst), iface)
+		s.move(dst, addr, p)
 	}
 	s.vars[okVar] = s.constBool(true)
 	s.endBlock()
@@ -6387,9 +6281,9 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 	// type assertion failed
 	s.startBlock(bFail)
 	if tmp == nil {
-		s.vars[valVar] = s.zeroVal(n.Type())
+		s.vars[valVar] = s.zeroVal(dst)
 	} else {
-		s.zero(n.Type(), addr)
+		s.zero(dst, addr)
 	}
 	s.vars[okVar] = s.constBool(false)
 	s.endBlock()
@@ -6398,10 +6292,10 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 	// merge point
 	s.startBlock(bEnd)
 	if tmp == nil {
-		res = s.variable(valVar, n.Type())
+		res = s.variable(valVar, dst)
 		delete(s.vars, valVar)
 	} else {
-		res = s.load(n.Type(), addr)
+		res = s.load(dst, addr)
 		s.vars[memVar] = s.newValue1A(ssa.OpVarKill, types.TypeMem, tmp.(*ir.Name), s.mem())
 	}
 	resok = s.variable(okVar, types.Types[types.TBOOL])
@@ -6463,7 +6357,8 @@ func (s *state) addNamedValue(n *ir.Name, v *ssa.Value) {
 	loc := ssa.LocalSlot{N: n, Type: n.Type(), Off: 0}
 	values, ok := s.f.NamedValues[loc]
 	if !ok {
-		s.f.Names = append(s.f.Names, loc)
+		s.f.Names = append(s.f.Names, &loc)
+		s.f.CanonicalLocalSlots[loc] = &loc
 	}
 	s.f.NamedValues[loc] = append(values, v)
 }
@@ -6598,6 +6493,7 @@ func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
 	x := base.Ctxt.Lookup(fmt.Sprintf("%s.arginfo%d", f.LSym.Name, f.ABI))
 
 	PtrSize := int64(types.PtrSize)
+	uintptrTyp := types.Types[types.TUINTPTR]
 
 	isAggregate := func(t *types.Type) bool {
 		return t.IsStruct() || t.IsArray() || t.IsComplex() || t.IsInterface() || t.IsString() || t.IsSlice()
@@ -6641,12 +6537,8 @@ func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
 	n := 0
 	writebyte := func(o uint8) { wOff = objw.Uint8(x, wOff, o) }
 
-	// Write one non-aggrgate arg/field/element if there is room.
-	// Returns whether to continue.
-	write1 := func(sz, offset int64) bool {
-		if n >= limit {
-			return false
-		}
+	// Write one non-aggrgate arg/field/element.
+	write1 := func(sz, offset int64) {
 		if offset >= _special {
 			writebyte(_offsetTooLarge)
 		} else {
@@ -6654,7 +6546,6 @@ func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
 			writebyte(uint8(sz))
 		}
 		n++
-		return true
 	}
 
 	// Visit t recursively and write it out.
@@ -6662,10 +6553,12 @@ func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
 	var visitType func(baseOffset int64, t *types.Type, depth int) bool
 	visitType = func(baseOffset int64, t *types.Type, depth int) bool {
 		if n >= limit {
+			writebyte(_dotdotdot)
 			return false
 		}
 		if !isAggregate(t) {
-			return write1(t.Size(), baseOffset)
+			write1(t.Size(), baseOffset)
+			return true
 		}
 		writebyte(_startAgg)
 		depth++
@@ -6675,58 +6568,47 @@ func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
 			n++
 			return true
 		}
-		var r bool
 		switch {
 		case t.IsInterface(), t.IsString():
-			r = write1(PtrSize, baseOffset) &&
-				write1(PtrSize, baseOffset+PtrSize)
+			_ = visitType(baseOffset, uintptrTyp, depth) &&
+				visitType(baseOffset+PtrSize, uintptrTyp, depth)
 		case t.IsSlice():
-			r = write1(PtrSize, baseOffset) &&
-				write1(PtrSize, baseOffset+PtrSize) &&
-				write1(PtrSize, baseOffset+PtrSize*2)
+			_ = visitType(baseOffset, uintptrTyp, depth) &&
+				visitType(baseOffset+PtrSize, uintptrTyp, depth) &&
+				visitType(baseOffset+PtrSize*2, uintptrTyp, depth)
 		case t.IsComplex():
-			r = write1(t.Size()/2, baseOffset) &&
-				write1(t.Size()/2, baseOffset+t.Size()/2)
+			_ = visitType(baseOffset, types.FloatForComplex(t), depth) &&
+				visitType(baseOffset+t.Size()/2, types.FloatForComplex(t), depth)
 		case t.IsArray():
-			r = true
 			if t.NumElem() == 0 {
 				n++ // {} counts as a component
 				break
 			}
 			for i := int64(0); i < t.NumElem(); i++ {
 				if !visitType(baseOffset, t.Elem(), depth) {
-					r = false
 					break
 				}
 				baseOffset += t.Elem().Size()
 			}
 		case t.IsStruct():
-			r = true
 			if t.NumFields() == 0 {
 				n++ // {} counts as a component
 				break
 			}
 			for _, field := range t.Fields().Slice() {
 				if !visitType(baseOffset+field.Offset, field.Type, depth) {
-					r = false
 					break
 				}
 			}
 		}
-		if !r {
-			writebyte(_dotdotdot)
-		}
 		writebyte(_endAgg)
-		return r
+		return true
 	}
 
-	c := true
 	for _, a := range abiInfo.InParams() {
-		if !c {
-			writebyte(_dotdotdot)
+		if !visitType(a.FrameOffset(abiInfo), a.Type, 0) {
 			break
 		}
-		c = visitType(a.FrameOffset(abiInfo), a.Type, 0)
 	}
 	writebyte(_endSeq)
 	if wOff > maxLen {
@@ -6931,8 +6813,12 @@ func genssa(f *ssa.Func, pp *objw.Progs) {
 		// recovers a panic, it will return to caller with right results.
 		// The results are already in memory, because they are not SSA'd
 		// when the function has defers (see canSSAName).
-		if f.OwnAux.ABIInfo().OutRegistersUsed() != 0 {
-			Arch.LoadRegResults(&s, f)
+		for _, o := range f.OwnAux.ABIInfo().OutParams() {
+			n := o.Name.(*ir.Name)
+			rts, offs := o.RegisterTypesAndOffsets()
+			for i := range o.Registers {
+				Arch.LoadRegResult(&s, f, rts[i], ssa.ObjRegForAbiReg(o.Registers[i], f.Config), n, offs[i])
+			}
 		}
 
 		pp.Prog(obj.ARET)
@@ -7470,18 +7356,6 @@ func (s *State) PrepareCall(v *ssa.Value) {
 
 	call, ok := v.Aux.(*ssa.AuxCall)
 
-	if ok && call.Fn == ir.Syms.Deferreturn {
-		// Deferred calls will appear to be returning to
-		// the CALL deferreturn(SB) that we are about to emit.
-		// However, the stack trace code will show the line
-		// of the instruction byte before the return PC.
-		// To avoid that being an unrelated instruction,
-		// insert an actual hardware NOP that will have the right line number.
-		// This is different from obj.ANOP, which is a virtual no-op
-		// that doesn't make it into the instruction stream.
-		Arch.Ginsnopdefer(s.pp)
-	}
-
 	if ok {
 		// Record call graph information for nowritebarrierrec
 		// analysis.
@@ -7552,86 +7426,6 @@ func (e *ssafn) Auto(pos src.XPos, t *types.Type) *ir.Name {
 	return typecheck.TempAt(pos, e.curfn, t) // Note: adds new auto to e.curfn.Func.Dcl list
 }
 
-func (e *ssafn) SplitString(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
-	ptrType := types.NewPtr(types.Types[types.TUINT8])
-	lenType := types.Types[types.TINT]
-	// Split this string up into two separate variables.
-	p := e.SplitSlot(&name, ".ptr", 0, ptrType)
-	l := e.SplitSlot(&name, ".len", ptrType.Size(), lenType)
-	return p, l
-}
-
-func (e *ssafn) SplitInterface(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
-	n := name.N
-	u := types.Types[types.TUINTPTR]
-	t := types.NewPtr(types.Types[types.TUINT8])
-	// Split this interface up into two separate variables.
-	f := ".itab"
-	if n.Type().IsEmptyInterface() {
-		f = ".type"
-	}
-	c := e.SplitSlot(&name, f, 0, u) // see comment in typebits.Set
-	d := e.SplitSlot(&name, ".data", u.Size(), t)
-	return c, d
-}
-
-func (e *ssafn) SplitSlice(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot, ssa.LocalSlot) {
-	ptrType := types.NewPtr(name.Type.Elem())
-	lenType := types.Types[types.TINT]
-	p := e.SplitSlot(&name, ".ptr", 0, ptrType)
-	l := e.SplitSlot(&name, ".len", ptrType.Size(), lenType)
-	c := e.SplitSlot(&name, ".cap", ptrType.Size()+lenType.Size(), lenType)
-	return p, l, c
-}
-
-func (e *ssafn) SplitComplex(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
-	s := name.Type.Size() / 2
-	var t *types.Type
-	if s == 8 {
-		t = types.Types[types.TFLOAT64]
-	} else {
-		t = types.Types[types.TFLOAT32]
-	}
-	r := e.SplitSlot(&name, ".real", 0, t)
-	i := e.SplitSlot(&name, ".imag", t.Size(), t)
-	return r, i
-}
-
-func (e *ssafn) SplitInt64(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
-	var t *types.Type
-	if name.Type.IsSigned() {
-		t = types.Types[types.TINT32]
-	} else {
-		t = types.Types[types.TUINT32]
-	}
-	if Arch.LinkArch.ByteOrder == binary.BigEndian {
-		return e.SplitSlot(&name, ".hi", 0, t), e.SplitSlot(&name, ".lo", t.Size(), types.Types[types.TUINT32])
-	}
-	return e.SplitSlot(&name, ".hi", t.Size(), t), e.SplitSlot(&name, ".lo", 0, types.Types[types.TUINT32])
-}
-
-func (e *ssafn) SplitStruct(name ssa.LocalSlot, i int) ssa.LocalSlot {
-	st := name.Type
-	// Note: the _ field may appear several times.  But
-	// have no fear, identically-named but distinct Autos are
-	// ok, albeit maybe confusing for a debugger.
-	return e.SplitSlot(&name, "."+st.FieldName(i), st.FieldOff(i), st.FieldType(i))
-}
-
-func (e *ssafn) SplitArray(name ssa.LocalSlot) ssa.LocalSlot {
-	n := name.N
-	at := name.Type
-	if at.NumElem() != 1 {
-		e.Fatalf(n.Pos(), "bad array size")
-	}
-	et := at.Elem()
-	return e.SplitSlot(&name, "[0]", 0, et)
-}
-
-func (e *ssafn) DerefItab(it *obj.LSym, offset int64) *obj.LSym {
-	return reflectdata.ITabSym(it, offset)
-}
-
 // SplitSlot returns a slot representing the data of parent starting at offset.
 func (e *ssafn) SplitSlot(parent *ssa.LocalSlot, suffix string, offset int64, t *types.Type) ssa.LocalSlot {
 	node := parent.N
@@ -7762,9 +7556,8 @@ func max8(a, b int8) int8 {
 	return b
 }
 
-// deferstruct makes a runtime._defer structure, with additional space for
-// stksize bytes of args.
-func deferstruct(stksize int64) *types.Type {
+// deferstruct makes a runtime._defer structure.
+func deferstruct() *types.Type {
 	makefield := func(name string, typ *types.Type) *types.Field {
 		// Unlike the global makefield function, this one needs to set Pkg
 		// because these types might be compared (in SSA CSE sorting).
@@ -7772,13 +7565,9 @@ func deferstruct(stksize int64) *types.Type {
 		sym := &types.Sym{Name: name, Pkg: types.LocalPkg}
 		return types.NewField(src.NoXPos, sym, typ)
 	}
-	argtype := types.NewArray(types.Types[types.TUINT8], stksize)
-	argtype.Width = stksize
-	argtype.Align = 1
 	// These fields must match the ones in runtime/runtime2.go:_defer and
-	// cmd/compile/internal/gc/ssa.go:(*state).call.
+	// (*state).call above.
 	fields := []*types.Field{
-		makefield("siz", types.Types[types.TUINT32]),
 		makefield("started", types.Types[types.TBOOL]),
 		makefield("heap", types.Types[types.TBOOL]),
 		makefield("openDefer", types.Types[types.TBOOL]),
@@ -7790,10 +7579,9 @@ func deferstruct(stksize int64) *types.Type {
 		makefield("fn", types.Types[types.TUINTPTR]),
 		makefield("_panic", types.Types[types.TUINTPTR]),
 		makefield("link", types.Types[types.TUINTPTR]),
-		makefield("framepc", types.Types[types.TUINTPTR]),
-		makefield("varp", types.Types[types.TUINTPTR]),
 		makefield("fd", types.Types[types.TUINTPTR]),
-		makefield("args", argtype),
+		makefield("varp", types.Types[types.TUINTPTR]),
+		makefield("framepc", types.Types[types.TUINTPTR]),
 	}
 
 	// build struct holding the above fields
diff --git a/src/cmd/compile/internal/staticdata/embed.go b/src/cmd/compile/internal/staticdata/embed.go
index 8936c4f5b44..0730d346b24 100644
--- a/src/cmd/compile/internal/staticdata/embed.go
+++ b/src/cmd/compile/internal/staticdata/embed.go
@@ -108,13 +108,6 @@ func WriteEmbed(v *ir.Name) {
 	// TODO(mdempsky): User errors should be reported by the frontend.
 
 	commentPos := (*v.Embed)[0].Pos
-	if !types.AllowsGoVersion(types.LocalPkg, 1, 16) {
-		prevPos := base.Pos
-		base.Pos = commentPos
-		base.ErrorfVers("go1.16", "go:embed")
-		base.Pos = prevPos
-		return
-	}
 	if base.Flag.Cfg.Embed.Patterns == nil {
 		base.ErrorfAt(commentPos, "invalid go:embed: build system did not supply embed configuration")
 		return
diff --git a/src/cmd/compile/internal/staticinit/sched.go b/src/cmd/compile/internal/staticinit/sched.go
index 0c97b6de747..9329a469899 100644
--- a/src/cmd/compile/internal/staticinit/sched.go
+++ b/src/cmd/compile/internal/staticinit/sched.go
@@ -403,10 +403,10 @@ func (s *Schedule) initplan(n ir.Node) {
 				base.Fatalf("initplan structlit")
 			}
 			a := a.(*ir.StructKeyExpr)
-			if a.Field.IsBlank() {
+			if a.Sym().IsBlank() {
 				continue
 			}
-			s.addvalue(p, a.Offset, a.Value)
+			s.addvalue(p, a.Field.Offset, a.Value)
 		}
 
 	case ir.OMAPLIT:
diff --git a/src/cmd/compile/internal/syntax/parser.go b/src/cmd/compile/internal/syntax/parser.go
index e7b8840b337..4fb6de10a82 100644
--- a/src/cmd/compile/internal/syntax/parser.go
+++ b/src/cmd/compile/internal/syntax/parser.go
@@ -604,7 +604,7 @@ func (p *parser) typeDecl(group *Group) Decl {
 			} else {
 				// x is the array length expression
 				if debug && x == nil {
-					panic("internal error: nil expression")
+					panic("length expression is nil")
 				}
 				d.Type = p.arrayType(pos, x)
 			}
@@ -1049,7 +1049,16 @@ loop:
 			}
 
 			// x[i:...
-			p.want(_Colon)
+			// For better error message, don't simply use p.want(_Colon) here (issue #47704).
+			if !p.got(_Colon) {
+				if p.mode&AllowGenerics == 0 {
+					p.syntaxError("expecting : or ]")
+					p.advance(_Colon, _Rbrack)
+				} else {
+					p.syntaxError("expecting comma, : or ]")
+					p.advance(_Comma, _Colon, _Rbrack)
+				}
+			}
 			p.xnest++
 			t := new(SliceExpr)
 			t.pos = pos
@@ -1100,7 +1109,7 @@ loop:
 					complit_ok = true
 				}
 			case *IndexExpr:
-				if p.xnest >= 0 {
+				if p.xnest >= 0 && !isValue(t) {
 					// x is possibly a composite literal type
 					complit_ok = true
 				}
@@ -1127,6 +1136,21 @@ loop:
 	return x
 }
 
+// isValue reports whether x syntactically must be a value (and not a type) expression.
+func isValue(x Expr) bool {
+	switch x := x.(type) {
+	case *BasicLit, *CompositeLit, *FuncLit, *SliceExpr, *AssertExpr, *TypeSwitchGuard, *CallExpr:
+		return true
+	case *Operation:
+		return x.Op != Mul || x.Y != nil // *T may be a type
+	case *ParenExpr:
+		return isValue(x.X)
+	case *IndexExpr:
+		return isValue(x.X) || isValue(x.Index)
+	}
+	return false
+}
+
 // Element = Expression | LiteralValue .
 func (p *parser) bare_complitexpr() Expr {
 	if trace {
@@ -1443,6 +1467,18 @@ func (p *parser) interfaceType() *InterfaceType {
 				}
 				return false
 			}
+
+		default:
+			if p.mode&AllowGenerics != 0 {
+				pos := p.pos()
+				if t := p.typeOrNil(); t != nil {
+					f := new(Field)
+					f.pos = pos
+					f.Type = t
+					typ.MethodList = append(typ.MethodList, p.embeddedElem(f))
+					return false
+				}
+			}
 		}
 
 		if p.mode&AllowGenerics != 0 {
diff --git a/src/cmd/compile/internal/syntax/positions.go b/src/cmd/compile/internal/syntax/positions.go
index b00f86c67cd..93596559a02 100644
--- a/src/cmd/compile/internal/syntax/positions.go
+++ b/src/cmd/compile/internal/syntax/positions.go
@@ -12,7 +12,7 @@ func StartPos(n Node) Pos {
 	for m := n; ; {
 		switch n := m.(type) {
 		case nil:
-			panic("internal error: nil")
+			panic("nil node")
 
 		// packages
 		case *File:
@@ -124,7 +124,7 @@ func EndPos(n Node) Pos {
 	for m := n; ; {
 		switch n := m.(type) {
 		case nil:
-			panic("internal error: nil")
+			panic("nil node")
 
 		// packages
 		case *File:
diff --git a/src/cmd/compile/internal/syntax/testdata/go2/linalg.go2 b/src/cmd/compile/internal/syntax/testdata/go2/linalg.go2
index 0d27603a583..822d0287e74 100644
--- a/src/cmd/compile/internal/syntax/testdata/go2/linalg.go2
+++ b/src/cmd/compile/internal/syntax/testdata/go2/linalg.go2
@@ -9,10 +9,10 @@ import "math"
 // Numeric is type bound that matches any numeric type.
 // It would likely be in a constraints package in the standard library.
 type Numeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		complex64, complex128
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		float32 | ~float64 |
+		complex64 | ~complex128
 }
 
 func DotProduct[T Numeric](s1, s2 []T) T {
@@ -42,14 +42,14 @@ func AbsDifference[T NumericAbs[T]](a, b T) T {
 
 // OrderedNumeric is a type bound that matches numeric types that support the < operator.
 type OrderedNumeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		float32 | ~float64
 }
 
 // Complex is a type bound that matches the two complex types, which do not have a < operator.
 type Complex interface {
-	type complex64, complex128
+	~complex64 | ~complex128
 }
 
 // OrderedAbs is a helper type that defines an Abs method for
diff --git a/src/cmd/compile/internal/syntax/testdata/go2/smoketest.go2 b/src/cmd/compile/internal/syntax/testdata/go2/smoketest.go2
index e5cfba06125..42efb425275 100644
--- a/src/cmd/compile/internal/syntax/testdata/go2/smoketest.go2
+++ b/src/cmd/compile/internal/syntax/testdata/go2/smoketest.go2
@@ -46,12 +46,12 @@ type _ struct{ T[int] }
 // interfaces
 type _ interface{
 	m()
-	type int
+	~int
 }
 
 type _ interface{
-	type int, float, string
-	type complex128
+	~int | ~float | ~string
+	~complex128
 	underlying(underlying underlying) underlying
 }
 
diff --git a/src/cmd/compile/internal/syntax/testdata/go2/typeinst2.go2 b/src/cmd/compile/internal/syntax/testdata/go2/typeinst2.go2
index 6e2104a5150..f3deb703b67 100644
--- a/src/cmd/compile/internal/syntax/testdata/go2/typeinst2.go2
+++ b/src/cmd/compile/internal/syntax/testdata/go2/typeinst2.go2
@@ -175,12 +175,12 @@ type _ interface {
 // Interface type lists can contain any type, incl. *Named types.
 // Verify that we use the underlying type to compute the operational type.
 type MyInt int
-func add1[T interface{type MyInt}](x T) T {
+func add1[T interface{ ~MyInt }](x T) T {
 	return x + 1
 }
 
 type MyString string
-func double[T interface{type MyInt, MyString}](x T) T {
+func double[T interface{ ~MyInt | ~MyString }](x T) T {
 	return x + x
 }
 
@@ -189,15 +189,15 @@ func double[T interface{type MyInt, MyString}](x T) T {
 // type lists.
 
 type E0 interface {
-	type int, bool, string
+	~int | ~bool | ~string
 }
 
 type E1 interface {
-	type int, float64, string
+	~int | ~float64 | ~string
 }
 
 type E2 interface {
-	type float64
+	~float64
 }
 
 type I0 interface {
diff --git a/src/cmd/compile/internal/syntax/testdata/go2/typeparams.go2 b/src/cmd/compile/internal/syntax/testdata/go2/typeparams.go2
index f78037f0f5d..111f7c10042 100644
--- a/src/cmd/compile/internal/syntax/testdata/go2/typeparams.go2
+++ b/src/cmd/compile/internal/syntax/testdata/go2/typeparams.go2
@@ -48,22 +48,22 @@ func swapswap[A, B any](a A, b B) (A, B) {
 
 type F[A, B any] func(A, B) (B, A)
 
-func min[T interface{ type int }](x, y T) T {
+func min[T interface{ ~int }](x, y T) T {
         if x < y {
                 return x
         }
         return y
 }
 
-func _[T interface{type int, float32}](x, y T) bool { return x < y }
+func _[T interface{ ~int | ~float32 }](x, y T) bool { return x < y }
 func _[T any](x, y T) bool { return x /* ERROR cannot compare */ < y }
-func _[T interface{type int, float32, bool}](x, y T) bool { return x /* ERROR cannot compare */ < y }
+func _[T interface{ ~int | ~float32 | ~bool }](x, y T) bool { return x /* ERROR cannot compare */ < y }
 
 func _[T C1[T]](x, y T) bool { return x /* ERROR cannot compare */ < y }
 func _[T C2[T]](x, y T) bool { return x < y }
 
 type C1[T any] interface{}
-type C2[T any] interface{ type int, float32 }
+type C2[T any] interface{ ~int | ~float32 }
 
 func new[T any]() *T {
         var x T
@@ -91,40 +91,40 @@ var _ = f3[int, rune, bool](1, struct{x rune}{}, nil)
 // indexing
 
 func _[T any] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type int }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type string }] (x T, i int) { _ = x[i] }
-func _[T interface{ type []int }] (x T, i int) { _ = x[i] }
-func _[T interface{ type [10]int, *[20]int, map[string]int }] (x T, i int) { _ = x[i] }
-func _[T interface{ type string, []byte }] (x T, i int) { _ = x[i] }
-func _[T interface{ type []int, [1]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
-func _[T interface{ type string, []rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~int }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~string }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[]int }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[10]int | ~*[20]int | ~map[string]int }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~string | ~[]byte }] (x T, i int) { _ = x[i] }
+func _[T interface{ ~[]int | ~[1]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
+func _[T interface{ ~string | ~[]rune }] (x T, i int) { _ = x /* ERROR "cannot index" */ [i] }
 
 // slicing
 // TODO(gri) implement this
 
-func _[T interface{ type string }] (x T, i, j, k int) { _ = x /* ERROR invalid operation */ [i:j:k] }
+func _[T interface{ ~string }] (x T, i, j, k int) { _ = x /* ERROR invalid operation */ [i:j:k] }
 
 // len/cap built-ins
 
 func _[T any](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string, []byte, int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string }](x T) { _ = len(x) }
-func _[T interface{ type [10]int }](x T) { _ = len(x) }
-func _[T interface{ type []byte }](x T) { _ = len(x) }
-func _[T interface{ type map[int]int }](x T) { _ = len(x) }
-func _[T interface{ type chan int }](x T) { _ = len(x) }
-func _[T interface{ type string, []byte, chan int }](x T) { _ = len(x) }
+func _[T interface{ ~int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string | ~[]byte | ~int }](x T) { _ = len(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string }](x T) { _ = len(x) }
+func _[T interface{ ~[10]int }](x T) { _ = len(x) }
+func _[T interface{ ~[]byte }](x T) { _ = len(x) }
+func _[T interface{ ~map[int]int }](x T) { _ = len(x) }
+func _[T interface{ ~chan int }](x T) { _ = len(x) }
+func _[T interface{ ~string | ~[]byte | ~chan int }](x T) { _ = len(x) }
 
 func _[T any](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string, []byte, int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type string }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type [10]int }](x T) { _ = cap(x) }
-func _[T interface{ type []byte }](x T) { _ = cap(x) }
-func _[T interface{ type map[int]int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
-func _[T interface{ type chan int }](x T) { _ = cap(x) }
-func _[T interface{ type []byte, chan int }](x T) { _ = cap(x) }
+func _[T interface{ ~int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string | ~[]byte | ~int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~string }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~[10]int }](x T) { _ = cap(x) }
+func _[T interface{ ~[]byte }](x T) { _ = cap(x) }
+func _[T interface{ ~map[int]int }](x T) { _ = cap(x /* ERROR invalid argument */ ) }
+func _[T interface{ ~chan int }](x T) { _ = cap(x) }
+func _[T interface{ ~[]byte | ~chan int }](x T) { _ = cap(x) }
 
 // range iteration
 
@@ -132,7 +132,7 @@ func _[T interface{}](x T) {
         for range x /* ERROR cannot range */ {}
 }
 
-func _[T interface{ type string, []string }](x T) {
+func _[T interface{ ~string | ~[]string }](x T) {
         for range x {}
         for i := range x { _ = i }
         for i, _ := range x { _ = i }
@@ -144,23 +144,23 @@ func _[T interface{ type string, []string }](x T) {
 }
 
 
-func _[T interface{ type string, []rune, map[int]rune }](x T) {
+func _[T interface{ ~string | ~[]rune | ~map[int]rune }](x T) {
         for _, e := range x { _ = e }
         for i, e := range x { _ = i; _ = e }
 }
 
-func _[T interface{ type string, []rune, map[string]rune }](x T) {
+func _[T interface{ ~string | ~[]rune | ~map[string]rune }](x T) {
         for _, e := range x { _ = e }
         for i, e := range x /* ERROR must have the same key type */ { _ = e }
 }
 
-func _[T interface{ type string, chan int }](x T) {
+func _[T interface{ ~string | ~chan int }](x T) {
         for range x {}
         for i := range x { _ = i }
         for i, _ := range x { _ = i } // TODO(gri) should get an error here: channels only return one value
 }
 
-func _[T interface{ type string, chan<-int }](x T) {
+func _[T interface{ ~string | ~chan<-int }](x T) {
         for i := range x /* ERROR send-only channel */ { _ = i }
 }
 
@@ -388,7 +388,7 @@ func _[T any](x T) {
 	}
 }
 
-func _[T interface{type int}](x T) {
+func _[T interface{ ~int }](x T) {
 	_ = x /* ERROR not an interface */ .(int)
 	switch x /* ERROR not an interface */ .(type) {
 	}
diff --git a/src/cmd/compile/internal/syntax/testdata/interface.go2 b/src/cmd/compile/internal/syntax/testdata/interface.go2
index a817327a43f..b399d751488 100644
--- a/src/cmd/compile/internal/syntax/testdata/interface.go2
+++ b/src/cmd/compile/internal/syntax/testdata/interface.go2
@@ -25,7 +25,6 @@ type _ interface {
 	~int | ~string
 }
 
-
 type _ interface {
 	m()
 	~int
@@ -34,3 +33,48 @@ type _ interface {
 	~int | ~string
 	type bool, int, float64
 }
+
+type _ interface {
+	int
+	[]byte
+	[10]int
+	struct{}
+	*int
+	func()
+	interface{}
+	map[string]int
+	chan T
+	chan<- T
+	<-chan T
+	T[int]
+}
+
+type _ interface {
+	int | string
+	[]byte | string
+	[10]int | string
+	struct{} | string
+	*int | string
+	func() | string
+	interface{} | string
+	map[string]int | string
+	chan T | string
+	chan<- T | string
+	<-chan T | string
+	T[int] | string
+}
+
+type _ interface {
+	~int | string
+	~[]byte | string
+	~[10]int | string
+	~struct{} | string
+	~*int | string
+	~func() | string
+	~interface{} | string
+	~map[string]int | string
+	~chan T | string
+	~chan<- T | string
+	~<-chan T | string
+	~T[int] | string
+}
diff --git a/src/cmd/compile/internal/syntax/testdata/issue46558.src b/src/cmd/compile/internal/syntax/testdata/issue46558.src
new file mode 100644
index 00000000000..a22b6008258
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/testdata/issue46558.src
@@ -0,0 +1,14 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func F(s string) {
+	switch s[0] {
+	case 'a':
+		case s[2] { // ERROR unexpected {
+		case 'b':
+		}
+	}
+} // ERROR non-declaration statement
diff --git a/src/cmd/compile/internal/syntax/testdata/issue47704.go2 b/src/cmd/compile/internal/syntax/testdata/issue47704.go2
new file mode 100644
index 00000000000..4e65857f3b1
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/testdata/issue47704.go2
@@ -0,0 +1,18 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// error messages for parser in generic mode
+func _() {
+	_ = m[] // ERROR expecting operand
+	_ = m[x,]
+	_ = m[x /* ERROR unexpected a */ a b c d]
+}
+
+// test case from the issue
+func f(m map[int]int) int {
+	return m[0 // ERROR expecting comma, \: or \]
+		]
+}
diff --git a/src/cmd/compile/internal/syntax/testdata/issue47704.src b/src/cmd/compile/internal/syntax/testdata/issue47704.src
new file mode 100644
index 00000000000..0156af7d8d1
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/testdata/issue47704.src
@@ -0,0 +1,18 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// error messages for parser in non-generic mode
+func _() {
+	_ = m[]   // ERROR expecting operand
+	_ = m[x,] // ERROR unexpected comma, expecting \: or \]
+	_ = m[x /* ERROR unexpected a */ a b c d]
+}
+
+// test case from the issue
+func f(m map[int]int) int {
+	return m[0 // ERROR expecting \: or \]
+		]
+}
diff --git a/src/cmd/compile/internal/syntax/walk.go b/src/cmd/compile/internal/syntax/walk.go
index c26e97a0d8f..b0258442048 100644
--- a/src/cmd/compile/internal/syntax/walk.go
+++ b/src/cmd/compile/internal/syntax/walk.go
@@ -8,31 +8,73 @@ package syntax
 
 import "fmt"
 
-// Walk traverses a syntax in pre-order: It starts by calling f(root);
-// root must not be nil. If f returns false (== "continue"), Walk calls
+// Inspect traverses an AST in pre-order: It starts by calling
+// f(node); node must not be nil. If f returns true, Inspect invokes f
+// recursively for each of the non-nil children of node, followed by a
+// call of f(nil).
+//
+// See Walk for caveats about shared nodes.
+func Inspect(root Node, f func(Node) bool) {
+	Walk(root, inspector(f))
+}
+
+type inspector func(Node) bool
+
+func (v inspector) Visit(node Node) Visitor {
+	if v(node) {
+		return v
+	}
+	return nil
+}
+
+// Crawl traverses a syntax in pre-order: It starts by calling f(root);
+// root must not be nil. If f returns false (== "continue"), Crawl calls
 // f recursively for each of the non-nil children of that node; if f
-// returns true (== "stop"), Walk does not traverse the respective node's
+// returns true (== "stop"), Crawl does not traverse the respective node's
 // children.
+//
+// See Walk for caveats about shared nodes.
+//
+// Deprecated: Use Inspect instead.
+func Crawl(root Node, f func(Node) bool) {
+	Inspect(root, func(node Node) bool {
+		return node != nil && !f(node)
+	})
+}
+
+// Walk traverses an AST in pre-order: It starts by calling
+// v.Visit(node); node must not be nil. If the visitor w returned by
+// v.Visit(node) is not nil, Walk is invoked recursively with visitor
+// w for each of the non-nil children of node, followed by a call of
+// w.Visit(nil).
+//
 // Some nodes may be shared among multiple parent nodes (e.g., types in
 // field lists such as type T in "a, b, c T"). Such shared nodes are
 // walked multiple times.
 // TODO(gri) Revisit this design. It may make sense to walk those nodes
 //           only once. A place where this matters is types2.TestResolveIdents.
-func Walk(root Node, f func(Node) bool) {
-	w := walker{f}
-	w.node(root)
+func Walk(root Node, v Visitor) {
+	walker{v}.node(root)
+}
+
+// A Visitor's Visit method is invoked for each node encountered by Walk.
+// If the result visitor w is not nil, Walk visits each of the children
+// of node with the visitor w, followed by a call of w.Visit(nil).
+type Visitor interface {
+	Visit(node Node) (w Visitor)
 }
 
 type walker struct {
-	f func(Node) bool
+	v Visitor
 }
 
-func (w *walker) node(n Node) {
+func (w walker) node(n Node) {
 	if n == nil {
-		panic("invalid syntax tree: nil node")
+		panic("nil node")
 	}
 
-	if w.f(n) {
+	w.v = w.v.Visit(n)
+	if w.v == nil {
 		return
 	}
 
@@ -285,33 +327,35 @@ func (w *walker) node(n Node) {
 	default:
 		panic(fmt.Sprintf("internal error: unknown node type %T", n))
 	}
+
+	w.v.Visit(nil)
 }
 
-func (w *walker) declList(list []Decl) {
+func (w walker) declList(list []Decl) {
 	for _, n := range list {
 		w.node(n)
 	}
 }
 
-func (w *walker) exprList(list []Expr) {
+func (w walker) exprList(list []Expr) {
 	for _, n := range list {
 		w.node(n)
 	}
 }
 
-func (w *walker) stmtList(list []Stmt) {
+func (w walker) stmtList(list []Stmt) {
 	for _, n := range list {
 		w.node(n)
 	}
 }
 
-func (w *walker) nameList(list []*Name) {
+func (w walker) nameList(list []*Name) {
 	for _, n := range list {
 		w.node(n)
 	}
 }
 
-func (w *walker) fieldList(list []*Field) {
+func (w walker) fieldList(list []*Field) {
 	for _, n := range list {
 		w.node(n)
 	}
diff --git a/src/cmd/compile/internal/test/abiutils_test.go b/src/cmd/compile/internal/test/abiutils_test.go
index b752c486126..839546bcb8a 100644
--- a/src/cmd/compile/internal/test/abiutils_test.go
+++ b/src/cmd/compile/internal/test/abiutils_test.go
@@ -33,6 +33,8 @@ func TestMain(m *testing.M) {
 	base.Ctxt.DiagFunc = base.Errorf
 	base.Ctxt.DiagFlush = base.FlushErrors
 	base.Ctxt.Bso = bufio.NewWriter(os.Stdout)
+	types.LocalPkg = types.NewPkg("", "local")
+	types.LocalPkg.Prefix = `""`
 	types.PtrSize = ssagen.Arch.LinkArch.PtrSize
 	types.RegSize = ssagen.Arch.LinkArch.RegSize
 	typecheck.InitUniverse()
@@ -309,8 +311,8 @@ func TestABIUtilsInterfaces(t *testing.T) {
 	ei := types.Types[types.TINTER] // interface{}
 	pei := types.NewPtr(ei)         // *interface{}
 	fldt := mkFuncType(types.FakeRecvType(), []*types.Type{},
-		[]*types.Type{types.UntypedString})
-	field := types.NewField(src.NoXPos, nil, fldt)
+		[]*types.Type{types.Types[types.TSTRING]})
+	field := types.NewField(src.NoXPos, typecheck.Lookup("F"), fldt)
 	nei := types.NewInterface(types.LocalPkg, []*types.Field{field})
 	i16 := types.Types[types.TINT16]
 	tb := types.Types[types.TBOOL]
@@ -322,12 +324,12 @@ func TestABIUtilsInterfaces(t *testing.T) {
         IN 0: R{ I0 I1 I2 } spilloffset: 0 typ: struct { int16; int16; bool }
         IN 1: R{ I3 I4 } spilloffset: 8 typ: interface {}
         IN 2: R{ I5 I6 } spilloffset: 24 typ: interface {}
-        IN 3: R{ I7 I8 } spilloffset: 40 typ: interface { () untyped string }
+        IN 3: R{ I7 I8 } spilloffset: 40 typ: interface { F() string }
         IN 4: R{ } offset: 0 typ: *interface {}
-        IN 5: R{ } offset: 8 typ: interface { () untyped string }
+        IN 5: R{ } offset: 8 typ: interface { F() string }
         IN 6: R{ } offset: 24 typ: int16
         OUT 0: R{ I0 I1 } spilloffset: -1 typ: interface {}
-        OUT 1: R{ I2 I3 } spilloffset: -1 typ: interface { () untyped string }
+        OUT 1: R{ I2 I3 } spilloffset: -1 typ: interface { F() string }
         OUT 2: R{ I4 } spilloffset: -1 typ: *interface {}
         offsetToSpillArea: 32 spillAreaSize: 56
 `)
diff --git a/src/cmd/compile/internal/test/align_test.go b/src/cmd/compile/internal/test/align_test.go
new file mode 100644
index 00000000000..32afc929736
--- /dev/null
+++ b/src/cmd/compile/internal/test/align_test.go
@@ -0,0 +1,96 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test to make sure that equality functions (and hash
+// functions) don't do unaligned reads on architectures
+// that can't do unaligned reads. See issue 46283.
+
+package test
+
+import "testing"
+
+type T1 struct {
+	x          float32
+	a, b, c, d int16 // memequal64
+}
+type T2 struct {
+	x          float32
+	a, b, c, d int32 // memequal128
+}
+
+type A2 [2]byte // eq uses a 2-byte load
+type A4 [4]byte // eq uses a 4-byte load
+type A8 [8]byte // eq uses an 8-byte load
+
+//go:noinline
+func cmpT1(p, q *T1) {
+	if *p != *q {
+		panic("comparison test wrong")
+	}
+}
+
+//go:noinline
+func cmpT2(p, q *T2) {
+	if *p != *q {
+		panic("comparison test wrong")
+	}
+}
+
+//go:noinline
+func cmpA2(p, q *A2) {
+	if *p != *q {
+		panic("comparison test wrong")
+	}
+}
+
+//go:noinline
+func cmpA4(p, q *A4) {
+	if *p != *q {
+		panic("comparison test wrong")
+	}
+}
+
+//go:noinline
+func cmpA8(p, q *A8) {
+	if *p != *q {
+		panic("comparison test wrong")
+	}
+}
+
+func TestAlignEqual(t *testing.T) {
+	cmpT1(&T1{}, &T1{})
+	cmpT2(&T2{}, &T2{})
+
+	m1 := map[T1]bool{}
+	m1[T1{}] = true
+	m1[T1{}] = false
+	if len(m1) != 1 {
+		t.Fatalf("len(m1)=%d, want 1", len(m1))
+	}
+	m2 := map[T2]bool{}
+	m2[T2{}] = true
+	m2[T2{}] = false
+	if len(m2) != 1 {
+		t.Fatalf("len(m2)=%d, want 1", len(m2))
+	}
+
+	type X2 struct {
+		y byte
+		z A2
+	}
+	var x2 X2
+	cmpA2(&x2.z, &A2{})
+	type X4 struct {
+		y byte
+		z A4
+	}
+	var x4 X4
+	cmpA4(&x4.z, &A4{})
+	type X8 struct {
+		y byte
+		z A8
+	}
+	var x8 X8
+	cmpA8(&x8.z, &A8{})
+}
diff --git a/src/cmd/compile/internal/test/inl_test.go b/src/cmd/compile/internal/test/inl_test.go
index 6f100033cf5..bbdbe0c37ca 100644
--- a/src/cmd/compile/internal/test/inl_test.go
+++ b/src/cmd/compile/internal/test/inl_test.go
@@ -42,13 +42,10 @@ func TestIntendedInlining(t *testing.T) {
 			"bucketMask",
 			"bucketShift",
 			"chanbuf",
-			"deferArgs",
-			"deferclass",
 			"evacuated",
 			"fastlog2",
 			"fastrand",
 			"float64bits",
-			"funcPC",
 			"getArgInfoFast",
 			"getm",
 			"getMCache",
@@ -65,7 +62,6 @@ func TestIntendedInlining(t *testing.T) {
 			"subtract1",
 			"subtractb",
 			"tophash",
-			"totaldefersize",
 			"(*bmap).keys",
 			"(*bmap).overflow",
 			"(*waitq).enqueue",
diff --git a/src/cmd/compile/internal/typecheck/bexport.go b/src/cmd/compile/internal/typecheck/bexport.go
index 4a84bb13fa4..cc7f91f9372 100644
--- a/src/cmd/compile/internal/typecheck/bexport.go
+++ b/src/cmd/compile/internal/typecheck/bexport.go
@@ -96,6 +96,9 @@ func predeclared() []*types.Type {
 
 			// any type, for builtin export data
 			types.Types[types.TANY],
+
+			// comparable
+			types.ComparableType,
 		}
 	}
 	return predecl
diff --git a/src/cmd/compile/internal/typecheck/builtin.go b/src/cmd/compile/internal/typecheck/builtin.go
index 67a894c7edd..3f177d91732 100644
--- a/src/cmd/compile/internal/typecheck/builtin.go
+++ b/src/cmd/compile/internal/typecheck/builtin.go
@@ -71,136 +71,135 @@ var runtimeDecls = [...]struct {
 	{"slicecopy", funcTag, 54},
 	{"decoderune", funcTag, 55},
 	{"countrunes", funcTag, 56},
-	{"convI2I", funcTag, 57},
-	{"convT16", funcTag, 59},
-	{"convT32", funcTag, 61},
-	{"convT64", funcTag, 62},
-	{"convTstring", funcTag, 63},
-	{"convTslice", funcTag, 66},
-	{"convT2E", funcTag, 67},
-	{"convT2Enoptr", funcTag, 67},
-	{"convT2I", funcTag, 67},
-	{"convT2Inoptr", funcTag, 67},
-	{"assertE2I", funcTag, 68},
-	{"assertE2I2", funcTag, 57},
-	{"assertI2I", funcTag, 68},
-	{"assertI2I2", funcTag, 57},
-	{"panicdottypeE", funcTag, 69},
-	{"panicdottypeI", funcTag, 69},
-	{"panicnildottype", funcTag, 70},
-	{"ifaceeq", funcTag, 72},
-	{"efaceeq", funcTag, 72},
-	{"fastrand", funcTag, 73},
-	{"makemap64", funcTag, 75},
-	{"makemap", funcTag, 76},
-	{"makemap_small", funcTag, 77},
-	{"mapaccess1", funcTag, 78},
-	{"mapaccess1_fast32", funcTag, 79},
-	{"mapaccess1_fast64", funcTag, 80},
-	{"mapaccess1_faststr", funcTag, 81},
-	{"mapaccess1_fat", funcTag, 82},
-	{"mapaccess2", funcTag, 83},
-	{"mapaccess2_fast32", funcTag, 84},
-	{"mapaccess2_fast64", funcTag, 85},
-	{"mapaccess2_faststr", funcTag, 86},
-	{"mapaccess2_fat", funcTag, 87},
-	{"mapassign", funcTag, 78},
-	{"mapassign_fast32", funcTag, 79},
-	{"mapassign_fast32ptr", funcTag, 88},
-	{"mapassign_fast64", funcTag, 80},
-	{"mapassign_fast64ptr", funcTag, 88},
-	{"mapassign_faststr", funcTag, 81},
-	{"mapiterinit", funcTag, 89},
-	{"mapdelete", funcTag, 89},
-	{"mapdelete_fast32", funcTag, 90},
-	{"mapdelete_fast64", funcTag, 91},
-	{"mapdelete_faststr", funcTag, 92},
-	{"mapiternext", funcTag, 93},
-	{"mapclear", funcTag, 94},
-	{"makechan64", funcTag, 96},
-	{"makechan", funcTag, 97},
-	{"chanrecv1", funcTag, 99},
-	{"chanrecv2", funcTag, 100},
-	{"chansend1", funcTag, 102},
+	{"convI2I", funcTag, 58},
+	{"convT", funcTag, 59},
+	{"convTnoptr", funcTag, 59},
+	{"convT16", funcTag, 61},
+	{"convT32", funcTag, 63},
+	{"convT64", funcTag, 64},
+	{"convTstring", funcTag, 65},
+	{"convTslice", funcTag, 68},
+	{"assertE2I", funcTag, 69},
+	{"assertE2I2", funcTag, 70},
+	{"assertI2I", funcTag, 69},
+	{"assertI2I2", funcTag, 70},
+	{"panicdottypeE", funcTag, 71},
+	{"panicdottypeI", funcTag, 71},
+	{"panicnildottype", funcTag, 72},
+	{"ifaceeq", funcTag, 73},
+	{"efaceeq", funcTag, 73},
+	{"fastrand", funcTag, 74},
+	{"makemap64", funcTag, 76},
+	{"makemap", funcTag, 77},
+	{"makemap_small", funcTag, 78},
+	{"mapaccess1", funcTag, 79},
+	{"mapaccess1_fast32", funcTag, 80},
+	{"mapaccess1_fast64", funcTag, 81},
+	{"mapaccess1_faststr", funcTag, 82},
+	{"mapaccess1_fat", funcTag, 83},
+	{"mapaccess2", funcTag, 84},
+	{"mapaccess2_fast32", funcTag, 85},
+	{"mapaccess2_fast64", funcTag, 86},
+	{"mapaccess2_faststr", funcTag, 87},
+	{"mapaccess2_fat", funcTag, 88},
+	{"mapassign", funcTag, 79},
+	{"mapassign_fast32", funcTag, 80},
+	{"mapassign_fast32ptr", funcTag, 89},
+	{"mapassign_fast64", funcTag, 81},
+	{"mapassign_fast64ptr", funcTag, 89},
+	{"mapassign_faststr", funcTag, 82},
+	{"mapiterinit", funcTag, 90},
+	{"mapdelete", funcTag, 90},
+	{"mapdelete_fast32", funcTag, 91},
+	{"mapdelete_fast64", funcTag, 92},
+	{"mapdelete_faststr", funcTag, 93},
+	{"mapiternext", funcTag, 94},
+	{"mapclear", funcTag, 95},
+	{"makechan64", funcTag, 97},
+	{"makechan", funcTag, 98},
+	{"chanrecv1", funcTag, 100},
+	{"chanrecv2", funcTag, 101},
+	{"chansend1", funcTag, 103},
 	{"closechan", funcTag, 30},
-	{"writeBarrier", varTag, 104},
-	{"typedmemmove", funcTag, 105},
-	{"typedmemclr", funcTag, 106},
-	{"typedslicecopy", funcTag, 107},
-	{"selectnbsend", funcTag, 108},
-	{"selectnbrecv", funcTag, 109},
-	{"selectsetpc", funcTag, 110},
-	{"selectgo", funcTag, 111},
+	{"writeBarrier", varTag, 105},
+	{"typedmemmove", funcTag, 106},
+	{"typedmemclr", funcTag, 107},
+	{"typedslicecopy", funcTag, 108},
+	{"selectnbsend", funcTag, 109},
+	{"selectnbrecv", funcTag, 110},
+	{"selectsetpc", funcTag, 111},
+	{"selectgo", funcTag, 112},
 	{"block", funcTag, 9},
-	{"makeslice", funcTag, 112},
-	{"makeslice64", funcTag, 113},
-	{"makeslicecopy", funcTag, 114},
-	{"growslice", funcTag, 116},
-	{"unsafeslice", funcTag, 117},
-	{"unsafeslice64", funcTag, 118},
-	{"memmove", funcTag, 119},
-	{"memclrNoHeapPointers", funcTag, 120},
-	{"memclrHasPointers", funcTag, 120},
-	{"memequal", funcTag, 121},
-	{"memequal0", funcTag, 122},
-	{"memequal8", funcTag, 122},
-	{"memequal16", funcTag, 122},
-	{"memequal32", funcTag, 122},
-	{"memequal64", funcTag, 122},
-	{"memequal128", funcTag, 122},
-	{"f32equal", funcTag, 123},
-	{"f64equal", funcTag, 123},
-	{"c64equal", funcTag, 123},
-	{"c128equal", funcTag, 123},
-	{"strequal", funcTag, 123},
-	{"interequal", funcTag, 123},
-	{"nilinterequal", funcTag, 123},
-	{"memhash", funcTag, 124},
-	{"memhash0", funcTag, 125},
-	{"memhash8", funcTag, 125},
-	{"memhash16", funcTag, 125},
-	{"memhash32", funcTag, 125},
-	{"memhash64", funcTag, 125},
-	{"memhash128", funcTag, 125},
-	{"f32hash", funcTag, 125},
-	{"f64hash", funcTag, 125},
-	{"c64hash", funcTag, 125},
-	{"c128hash", funcTag, 125},
-	{"strhash", funcTag, 125},
-	{"interhash", funcTag, 125},
-	{"nilinterhash", funcTag, 125},
-	{"int64div", funcTag, 126},
-	{"uint64div", funcTag, 127},
-	{"int64mod", funcTag, 126},
-	{"uint64mod", funcTag, 127},
-	{"float64toint64", funcTag, 128},
-	{"float64touint64", funcTag, 129},
-	{"float64touint32", funcTag, 130},
-	{"int64tofloat64", funcTag, 131},
-	{"uint64tofloat64", funcTag, 132},
-	{"uint32tofloat64", funcTag, 133},
-	{"complex128div", funcTag, 134},
-	{"getcallerpc", funcTag, 135},
-	{"getcallersp", funcTag, 135},
+	{"makeslice", funcTag, 113},
+	{"makeslice64", funcTag, 114},
+	{"makeslicecopy", funcTag, 115},
+	{"growslice", funcTag, 117},
+	{"unsafeslice", funcTag, 118},
+	{"unsafeslice64", funcTag, 119},
+	{"unsafeslicecheckptr", funcTag, 119},
+	{"memmove", funcTag, 120},
+	{"memclrNoHeapPointers", funcTag, 121},
+	{"memclrHasPointers", funcTag, 121},
+	{"memequal", funcTag, 122},
+	{"memequal0", funcTag, 123},
+	{"memequal8", funcTag, 123},
+	{"memequal16", funcTag, 123},
+	{"memequal32", funcTag, 123},
+	{"memequal64", funcTag, 123},
+	{"memequal128", funcTag, 123},
+	{"f32equal", funcTag, 124},
+	{"f64equal", funcTag, 124},
+	{"c64equal", funcTag, 124},
+	{"c128equal", funcTag, 124},
+	{"strequal", funcTag, 124},
+	{"interequal", funcTag, 124},
+	{"nilinterequal", funcTag, 124},
+	{"memhash", funcTag, 125},
+	{"memhash0", funcTag, 126},
+	{"memhash8", funcTag, 126},
+	{"memhash16", funcTag, 126},
+	{"memhash32", funcTag, 126},
+	{"memhash64", funcTag, 126},
+	{"memhash128", funcTag, 126},
+	{"f32hash", funcTag, 126},
+	{"f64hash", funcTag, 126},
+	{"c64hash", funcTag, 126},
+	{"c128hash", funcTag, 126},
+	{"strhash", funcTag, 126},
+	{"interhash", funcTag, 126},
+	{"nilinterhash", funcTag, 126},
+	{"int64div", funcTag, 127},
+	{"uint64div", funcTag, 128},
+	{"int64mod", funcTag, 127},
+	{"uint64mod", funcTag, 128},
+	{"float64toint64", funcTag, 129},
+	{"float64touint64", funcTag, 130},
+	{"float64touint32", funcTag, 131},
+	{"int64tofloat64", funcTag, 132},
+	{"uint64tofloat64", funcTag, 133},
+	{"uint32tofloat64", funcTag, 134},
+	{"complex128div", funcTag, 135},
+	{"getcallerpc", funcTag, 136},
+	{"getcallersp", funcTag, 136},
 	{"racefuncenter", funcTag, 31},
 	{"racefuncexit", funcTag, 9},
 	{"raceread", funcTag, 31},
 	{"racewrite", funcTag, 31},
-	{"racereadrange", funcTag, 136},
-	{"racewriterange", funcTag, 136},
-	{"msanread", funcTag, 136},
-	{"msanwrite", funcTag, 136},
-	{"msanmove", funcTag, 137},
-	{"checkptrAlignment", funcTag, 138},
-	{"checkptrArithmetic", funcTag, 140},
-	{"libfuzzerTraceCmp1", funcTag, 141},
-	{"libfuzzerTraceCmp2", funcTag, 142},
-	{"libfuzzerTraceCmp4", funcTag, 143},
-	{"libfuzzerTraceCmp8", funcTag, 144},
-	{"libfuzzerTraceConstCmp1", funcTag, 141},
-	{"libfuzzerTraceConstCmp2", funcTag, 142},
-	{"libfuzzerTraceConstCmp4", funcTag, 143},
-	{"libfuzzerTraceConstCmp8", funcTag, 144},
+	{"racereadrange", funcTag, 137},
+	{"racewriterange", funcTag, 137},
+	{"msanread", funcTag, 137},
+	{"msanwrite", funcTag, 137},
+	{"msanmove", funcTag, 138},
+	{"checkptrAlignment", funcTag, 139},
+	{"checkptrArithmetic", funcTag, 141},
+	{"libfuzzerTraceCmp1", funcTag, 142},
+	{"libfuzzerTraceCmp2", funcTag, 143},
+	{"libfuzzerTraceCmp4", funcTag, 144},
+	{"libfuzzerTraceCmp8", funcTag, 145},
+	{"libfuzzerTraceConstCmp1", funcTag, 142},
+	{"libfuzzerTraceConstCmp2", funcTag, 143},
+	{"libfuzzerTraceConstCmp4", funcTag, 144},
+	{"libfuzzerTraceConstCmp8", funcTag, 145},
 	{"x86HasPOPCNT", varTag, 6},
 	{"x86HasSSE41", varTag, 6},
 	{"x86HasFMA", varTag, 6},
@@ -223,7 +222,7 @@ func params(tlist ...*types.Type) []*types.Field {
 }
 
 func runtimeTypes() []*types.Type {
-	var typs [145]*types.Type
+	var typs [146]*types.Type
 	typs[0] = types.ByteType
 	typs[1] = types.NewPtr(typs[0])
 	typs[2] = types.Types[types.TANY]
@@ -281,93 +280,94 @@ func runtimeTypes() []*types.Type {
 	typs[54] = newSig(params(typs[3], typs[15], typs[3], typs[15], typs[5]), params(typs[15]))
 	typs[55] = newSig(params(typs[28], typs[15]), params(typs[46], typs[15]))
 	typs[56] = newSig(params(typs[28]), params(typs[15]))
-	typs[57] = newSig(params(typs[1], typs[2]), params(typs[2]))
-	typs[58] = types.Types[types.TUINT16]
-	typs[59] = newSig(params(typs[58]), params(typs[7]))
-	typs[60] = types.Types[types.TUINT32]
+	typs[57] = types.NewPtr(typs[5])
+	typs[58] = newSig(params(typs[1], typs[57]), params(typs[57]))
+	typs[59] = newSig(params(typs[1], typs[3]), params(typs[7]))
+	typs[60] = types.Types[types.TUINT16]
 	typs[61] = newSig(params(typs[60]), params(typs[7]))
-	typs[62] = newSig(params(typs[24]), params(typs[7]))
-	typs[63] = newSig(params(typs[28]), params(typs[7]))
-	typs[64] = types.Types[types.TUINT8]
-	typs[65] = types.NewSlice(typs[64])
-	typs[66] = newSig(params(typs[65]), params(typs[7]))
-	typs[67] = newSig(params(typs[1], typs[3]), params(typs[2]))
-	typs[68] = newSig(params(typs[1], typs[1]), params(typs[1]))
-	typs[69] = newSig(params(typs[1], typs[1], typs[1]), nil)
-	typs[70] = newSig(params(typs[1]), nil)
-	typs[71] = types.NewPtr(typs[5])
-	typs[72] = newSig(params(typs[71], typs[7], typs[7]), params(typs[6]))
-	typs[73] = newSig(nil, params(typs[60]))
-	typs[74] = types.NewMap(typs[2], typs[2])
-	typs[75] = newSig(params(typs[1], typs[22], typs[3]), params(typs[74]))
-	typs[76] = newSig(params(typs[1], typs[15], typs[3]), params(typs[74]))
-	typs[77] = newSig(nil, params(typs[74]))
-	typs[78] = newSig(params(typs[1], typs[74], typs[3]), params(typs[3]))
-	typs[79] = newSig(params(typs[1], typs[74], typs[60]), params(typs[3]))
-	typs[80] = newSig(params(typs[1], typs[74], typs[24]), params(typs[3]))
-	typs[81] = newSig(params(typs[1], typs[74], typs[28]), params(typs[3]))
-	typs[82] = newSig(params(typs[1], typs[74], typs[3], typs[1]), params(typs[3]))
-	typs[83] = newSig(params(typs[1], typs[74], typs[3]), params(typs[3], typs[6]))
-	typs[84] = newSig(params(typs[1], typs[74], typs[60]), params(typs[3], typs[6]))
-	typs[85] = newSig(params(typs[1], typs[74], typs[24]), params(typs[3], typs[6]))
-	typs[86] = newSig(params(typs[1], typs[74], typs[28]), params(typs[3], typs[6]))
-	typs[87] = newSig(params(typs[1], typs[74], typs[3], typs[1]), params(typs[3], typs[6]))
-	typs[88] = newSig(params(typs[1], typs[74], typs[7]), params(typs[3]))
-	typs[89] = newSig(params(typs[1], typs[74], typs[3]), nil)
-	typs[90] = newSig(params(typs[1], typs[74], typs[60]), nil)
-	typs[91] = newSig(params(typs[1], typs[74], typs[24]), nil)
-	typs[92] = newSig(params(typs[1], typs[74], typs[28]), nil)
-	typs[93] = newSig(params(typs[3]), nil)
-	typs[94] = newSig(params(typs[1], typs[74]), nil)
-	typs[95] = types.NewChan(typs[2], types.Cboth)
-	typs[96] = newSig(params(typs[1], typs[22]), params(typs[95]))
-	typs[97] = newSig(params(typs[1], typs[15]), params(typs[95]))
-	typs[98] = types.NewChan(typs[2], types.Crecv)
-	typs[99] = newSig(params(typs[98], typs[3]), nil)
-	typs[100] = newSig(params(typs[98], typs[3]), params(typs[6]))
-	typs[101] = types.NewChan(typs[2], types.Csend)
-	typs[102] = newSig(params(typs[101], typs[3]), nil)
-	typs[103] = types.NewArray(typs[0], 3)
-	typs[104] = types.NewStruct(types.NoPkg, []*types.Field{types.NewField(src.NoXPos, Lookup("enabled"), typs[6]), types.NewField(src.NoXPos, Lookup("pad"), typs[103]), types.NewField(src.NoXPos, Lookup("needed"), typs[6]), types.NewField(src.NoXPos, Lookup("cgo"), typs[6]), types.NewField(src.NoXPos, Lookup("alignme"), typs[24])})
-	typs[105] = newSig(params(typs[1], typs[3], typs[3]), nil)
-	typs[106] = newSig(params(typs[1], typs[3]), nil)
-	typs[107] = newSig(params(typs[1], typs[3], typs[15], typs[3], typs[15]), params(typs[15]))
-	typs[108] = newSig(params(typs[101], typs[3]), params(typs[6]))
-	typs[109] = newSig(params(typs[3], typs[98]), params(typs[6], typs[6]))
-	typs[110] = newSig(params(typs[71]), nil)
-	typs[111] = newSig(params(typs[1], typs[1], typs[71], typs[15], typs[15], typs[6]), params(typs[15], typs[6]))
-	typs[112] = newSig(params(typs[1], typs[15], typs[15]), params(typs[7]))
-	typs[113] = newSig(params(typs[1], typs[22], typs[22]), params(typs[7]))
-	typs[114] = newSig(params(typs[1], typs[15], typs[15], typs[7]), params(typs[7]))
-	typs[115] = types.NewSlice(typs[2])
-	typs[116] = newSig(params(typs[1], typs[115], typs[15]), params(typs[115]))
-	typs[117] = newSig(params(typs[1], typs[15]), nil)
-	typs[118] = newSig(params(typs[1], typs[22]), nil)
-	typs[119] = newSig(params(typs[3], typs[3], typs[5]), nil)
-	typs[120] = newSig(params(typs[7], typs[5]), nil)
-	typs[121] = newSig(params(typs[3], typs[3], typs[5]), params(typs[6]))
-	typs[122] = newSig(params(typs[3], typs[3]), params(typs[6]))
-	typs[123] = newSig(params(typs[7], typs[7]), params(typs[6]))
-	typs[124] = newSig(params(typs[7], typs[5], typs[5]), params(typs[5]))
-	typs[125] = newSig(params(typs[7], typs[5]), params(typs[5]))
-	typs[126] = newSig(params(typs[22], typs[22]), params(typs[22]))
-	typs[127] = newSig(params(typs[24], typs[24]), params(typs[24]))
-	typs[128] = newSig(params(typs[20]), params(typs[22]))
-	typs[129] = newSig(params(typs[20]), params(typs[24]))
-	typs[130] = newSig(params(typs[20]), params(typs[60]))
-	typs[131] = newSig(params(typs[22]), params(typs[20]))
-	typs[132] = newSig(params(typs[24]), params(typs[20]))
-	typs[133] = newSig(params(typs[60]), params(typs[20]))
-	typs[134] = newSig(params(typs[26], typs[26]), params(typs[26]))
-	typs[135] = newSig(nil, params(typs[5]))
-	typs[136] = newSig(params(typs[5], typs[5]), nil)
-	typs[137] = newSig(params(typs[5], typs[5], typs[5]), nil)
-	typs[138] = newSig(params(typs[7], typs[1], typs[5]), nil)
-	typs[139] = types.NewSlice(typs[7])
-	typs[140] = newSig(params(typs[7], typs[139]), nil)
-	typs[141] = newSig(params(typs[64], typs[64]), nil)
-	typs[142] = newSig(params(typs[58], typs[58]), nil)
+	typs[62] = types.Types[types.TUINT32]
+	typs[63] = newSig(params(typs[62]), params(typs[7]))
+	typs[64] = newSig(params(typs[24]), params(typs[7]))
+	typs[65] = newSig(params(typs[28]), params(typs[7]))
+	typs[66] = types.Types[types.TUINT8]
+	typs[67] = types.NewSlice(typs[66])
+	typs[68] = newSig(params(typs[67]), params(typs[7]))
+	typs[69] = newSig(params(typs[1], typs[1]), params(typs[1]))
+	typs[70] = newSig(params(typs[1], typs[2]), params(typs[2]))
+	typs[71] = newSig(params(typs[1], typs[1], typs[1]), nil)
+	typs[72] = newSig(params(typs[1]), nil)
+	typs[73] = newSig(params(typs[57], typs[7], typs[7]), params(typs[6]))
+	typs[74] = newSig(nil, params(typs[62]))
+	typs[75] = types.NewMap(typs[2], typs[2])
+	typs[76] = newSig(params(typs[1], typs[22], typs[3]), params(typs[75]))
+	typs[77] = newSig(params(typs[1], typs[15], typs[3]), params(typs[75]))
+	typs[78] = newSig(nil, params(typs[75]))
+	typs[79] = newSig(params(typs[1], typs[75], typs[3]), params(typs[3]))
+	typs[80] = newSig(params(typs[1], typs[75], typs[62]), params(typs[3]))
+	typs[81] = newSig(params(typs[1], typs[75], typs[24]), params(typs[3]))
+	typs[82] = newSig(params(typs[1], typs[75], typs[28]), params(typs[3]))
+	typs[83] = newSig(params(typs[1], typs[75], typs[3], typs[1]), params(typs[3]))
+	typs[84] = newSig(params(typs[1], typs[75], typs[3]), params(typs[3], typs[6]))
+	typs[85] = newSig(params(typs[1], typs[75], typs[62]), params(typs[3], typs[6]))
+	typs[86] = newSig(params(typs[1], typs[75], typs[24]), params(typs[3], typs[6]))
+	typs[87] = newSig(params(typs[1], typs[75], typs[28]), params(typs[3], typs[6]))
+	typs[88] = newSig(params(typs[1], typs[75], typs[3], typs[1]), params(typs[3], typs[6]))
+	typs[89] = newSig(params(typs[1], typs[75], typs[7]), params(typs[3]))
+	typs[90] = newSig(params(typs[1], typs[75], typs[3]), nil)
+	typs[91] = newSig(params(typs[1], typs[75], typs[62]), nil)
+	typs[92] = newSig(params(typs[1], typs[75], typs[24]), nil)
+	typs[93] = newSig(params(typs[1], typs[75], typs[28]), nil)
+	typs[94] = newSig(params(typs[3]), nil)
+	typs[95] = newSig(params(typs[1], typs[75]), nil)
+	typs[96] = types.NewChan(typs[2], types.Cboth)
+	typs[97] = newSig(params(typs[1], typs[22]), params(typs[96]))
+	typs[98] = newSig(params(typs[1], typs[15]), params(typs[96]))
+	typs[99] = types.NewChan(typs[2], types.Crecv)
+	typs[100] = newSig(params(typs[99], typs[3]), nil)
+	typs[101] = newSig(params(typs[99], typs[3]), params(typs[6]))
+	typs[102] = types.NewChan(typs[2], types.Csend)
+	typs[103] = newSig(params(typs[102], typs[3]), nil)
+	typs[104] = types.NewArray(typs[0], 3)
+	typs[105] = types.NewStruct(types.NoPkg, []*types.Field{types.NewField(src.NoXPos, Lookup("enabled"), typs[6]), types.NewField(src.NoXPos, Lookup("pad"), typs[104]), types.NewField(src.NoXPos, Lookup("needed"), typs[6]), types.NewField(src.NoXPos, Lookup("cgo"), typs[6]), types.NewField(src.NoXPos, Lookup("alignme"), typs[24])})
+	typs[106] = newSig(params(typs[1], typs[3], typs[3]), nil)
+	typs[107] = newSig(params(typs[1], typs[3]), nil)
+	typs[108] = newSig(params(typs[1], typs[3], typs[15], typs[3], typs[15]), params(typs[15]))
+	typs[109] = newSig(params(typs[102], typs[3]), params(typs[6]))
+	typs[110] = newSig(params(typs[3], typs[99]), params(typs[6], typs[6]))
+	typs[111] = newSig(params(typs[57]), nil)
+	typs[112] = newSig(params(typs[1], typs[1], typs[57], typs[15], typs[15], typs[6]), params(typs[15], typs[6]))
+	typs[113] = newSig(params(typs[1], typs[15], typs[15]), params(typs[7]))
+	typs[114] = newSig(params(typs[1], typs[22], typs[22]), params(typs[7]))
+	typs[115] = newSig(params(typs[1], typs[15], typs[15], typs[7]), params(typs[7]))
+	typs[116] = types.NewSlice(typs[2])
+	typs[117] = newSig(params(typs[1], typs[116], typs[15]), params(typs[116]))
+	typs[118] = newSig(params(typs[1], typs[7], typs[15]), nil)
+	typs[119] = newSig(params(typs[1], typs[7], typs[22]), nil)
+	typs[120] = newSig(params(typs[3], typs[3], typs[5]), nil)
+	typs[121] = newSig(params(typs[7], typs[5]), nil)
+	typs[122] = newSig(params(typs[3], typs[3], typs[5]), params(typs[6]))
+	typs[123] = newSig(params(typs[3], typs[3]), params(typs[6]))
+	typs[124] = newSig(params(typs[7], typs[7]), params(typs[6]))
+	typs[125] = newSig(params(typs[7], typs[5], typs[5]), params(typs[5]))
+	typs[126] = newSig(params(typs[7], typs[5]), params(typs[5]))
+	typs[127] = newSig(params(typs[22], typs[22]), params(typs[22]))
+	typs[128] = newSig(params(typs[24], typs[24]), params(typs[24]))
+	typs[129] = newSig(params(typs[20]), params(typs[22]))
+	typs[130] = newSig(params(typs[20]), params(typs[24]))
+	typs[131] = newSig(params(typs[20]), params(typs[62]))
+	typs[132] = newSig(params(typs[22]), params(typs[20]))
+	typs[133] = newSig(params(typs[24]), params(typs[20]))
+	typs[134] = newSig(params(typs[62]), params(typs[20]))
+	typs[135] = newSig(params(typs[26], typs[26]), params(typs[26]))
+	typs[136] = newSig(nil, params(typs[5]))
+	typs[137] = newSig(params(typs[5], typs[5]), nil)
+	typs[138] = newSig(params(typs[5], typs[5], typs[5]), nil)
+	typs[139] = newSig(params(typs[7], typs[1], typs[5]), nil)
+	typs[140] = types.NewSlice(typs[7])
+	typs[141] = newSig(params(typs[7], typs[140]), nil)
+	typs[142] = newSig(params(typs[66], typs[66]), nil)
 	typs[143] = newSig(params(typs[60], typs[60]), nil)
-	typs[144] = newSig(params(typs[24], typs[24]), nil)
+	typs[144] = newSig(params(typs[62], typs[62]), nil)
+	typs[145] = newSig(params(typs[24], typs[24]), nil)
 	return typs[:]
 }
diff --git a/src/cmd/compile/internal/typecheck/builtin/runtime.go b/src/cmd/compile/internal/typecheck/builtin/runtime.go
index ebeaeae79ec..605b9042880 100644
--- a/src/cmd/compile/internal/typecheck/builtin/runtime.go
+++ b/src/cmd/compile/internal/typecheck/builtin/runtime.go
@@ -84,10 +84,15 @@ func decoderune(string, int) (retv rune, retk int)
 func countrunes(string) int
 
 // Non-empty-interface to non-empty-interface conversion.
-func convI2I(typ *byte, elem any) (ret any)
+func convI2I(typ *byte, itab *uintptr) (ret *uintptr)
 
-// Specialized type-to-interface conversion.
-// These return only a data pointer.
+// Convert non-interface type to the data word of a (empty or nonempty) interface.
+func convT(typ *byte, elem *any) unsafe.Pointer
+
+// Same as convT, for types with no pointers in them.
+func convTnoptr(typ *byte, elem *any) unsafe.Pointer
+
+// Specialized versions of convT for specific types.
 // These functions take concrete types in the runtime. But they may
 // be used for a wider range of types, which have the same memory
 // layout as the parameter type. The compiler converts the
@@ -99,14 +104,6 @@ func convT64(val uint64) unsafe.Pointer
 func convTstring(val string) unsafe.Pointer
 func convTslice(val []uint8) unsafe.Pointer
 
-// Type to empty-interface conversion.
-func convT2E(typ *byte, elem *any) (ret any)
-func convT2Enoptr(typ *byte, elem *any) (ret any)
-
-// Type to non-empty-interface conversion.
-func convT2I(tab *byte, elem *any) (ret any)
-func convT2Inoptr(tab *byte, elem *any) (ret any)
-
 // interface type assertions x.(T)
 func assertE2I(inter *byte, typ *byte) *byte
 func assertE2I2(inter *byte, eface any) (ret any)
@@ -183,8 +180,9 @@ func makeslice(typ *byte, len int, cap int) unsafe.Pointer
 func makeslice64(typ *byte, len int64, cap int64) unsafe.Pointer
 func makeslicecopy(typ *byte, tolen int, fromlen int, from unsafe.Pointer) unsafe.Pointer
 func growslice(typ *byte, old []any, cap int) (ary []any)
-func unsafeslice(typ *byte, len int)
-func unsafeslice64(typ *byte, len int64)
+func unsafeslice(typ *byte, ptr unsafe.Pointer, len int)
+func unsafeslice64(typ *byte, ptr unsafe.Pointer, len int64)
+func unsafeslicecheckptr(typ *byte, ptr unsafe.Pointer, len int64)
 
 func memmove(to *any, frm *any, length uintptr)
 func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
diff --git a/src/cmd/compile/internal/typecheck/const.go b/src/cmd/compile/internal/typecheck/const.go
index 5a35eeade9f..f8150d249a6 100644
--- a/src/cmd/compile/internal/typecheck/const.go
+++ b/src/cmd/compile/internal/typecheck/const.go
@@ -633,6 +633,17 @@ func defaultlit2(l ir.Node, r ir.Node, force bool) (ir.Node, ir.Node) {
 	if l.Type() == nil || r.Type() == nil {
 		return l, r
 	}
+
+	if !l.Type().IsInterface() && !r.Type().IsInterface() {
+		// Can't mix bool with non-bool, string with non-string.
+		if l.Type().IsBoolean() != r.Type().IsBoolean() {
+			return l, r
+		}
+		if l.Type().IsString() != r.Type().IsString() {
+			return l, r
+		}
+	}
+
 	if !l.Type().IsUntyped() {
 		r = convlit(r, l.Type())
 		return l, r
@@ -647,17 +658,10 @@ func defaultlit2(l ir.Node, r ir.Node, force bool) (ir.Node, ir.Node) {
 		return l, r
 	}
 
-	// Can't mix bool with non-bool, string with non-string, or nil with anything (untyped).
-	if l.Type().IsBoolean() != r.Type().IsBoolean() {
-		return l, r
-	}
-	if l.Type().IsString() != r.Type().IsString() {
-		return l, r
-	}
+	// Can't mix nil with anything untyped.
 	if ir.IsNil(l) || ir.IsNil(r) {
 		return l, r
 	}
-
 	t := defaultType(mixUntyped(l.Type(), r.Type()))
 	l = convlit(l, t)
 	r = convlit(r, t)
@@ -897,7 +901,7 @@ func evalunsafe(n ir.Node) int64 {
 		switch tsel.Op() {
 		case ir.ODOT, ir.ODOTPTR:
 			break
-		case ir.OCALLPART:
+		case ir.OMETHVALUE:
 			base.Errorf("invalid expression %v: argument is a method value", n)
 			return 0
 		default:
diff --git a/src/cmd/compile/internal/typecheck/crawler.go b/src/cmd/compile/internal/typecheck/crawler.go
new file mode 100644
index 00000000000..9a348b9f374
--- /dev/null
+++ b/src/cmd/compile/internal/typecheck/crawler.go
@@ -0,0 +1,231 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package typecheck
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/types"
+)
+
+// crawlExports crawls the type/object graph rooted at the given list
+// of exported objects. Any functions that are found to be potentially
+// callable by importers are marked with ExportInline so that
+// iexport.go knows to re-export their inline body.
+func crawlExports(exports []*ir.Name) {
+	p := crawler{
+		marked:   make(map[*types.Type]bool),
+		embedded: make(map[*types.Type]bool),
+	}
+	for _, n := range exports {
+		p.markObject(n)
+	}
+}
+
+type crawler struct {
+	marked   map[*types.Type]bool // types already seen by markType
+	embedded map[*types.Type]bool // types already seen by markEmbed
+}
+
+// markObject visits a reachable object.
+func (p *crawler) markObject(n *ir.Name) {
+	if n.Op() == ir.ONAME && n.Class == ir.PFUNC {
+		p.markInlBody(n)
+	}
+
+	// If a declared type name is reachable, users can embed it in their
+	// own types, which makes even its unexported methods reachable.
+	if n.Op() == ir.OTYPE {
+		p.markEmbed(n.Type())
+	}
+
+	p.markType(n.Type())
+}
+
+// markType recursively visits types reachable from t to identify
+// functions whose inline bodies may be needed.
+func (p *crawler) markType(t *types.Type) {
+	if t.IsInstantiatedGeneric() {
+		// Re-instantiated types don't add anything new, so don't follow them.
+		return
+	}
+	if p.marked[t] {
+		return
+	}
+	p.marked[t] = true
+
+	// If this is a defined type, mark all of its associated
+	// methods. Skip interface types because t.Methods contains
+	// only their unexpanded method set (i.e., exclusive of
+	// interface embeddings), and the switch statement below
+	// handles their full method set.
+	if t.Sym() != nil && t.Kind() != types.TINTER {
+		for _, m := range t.Methods().Slice() {
+			if types.IsExported(m.Sym.Name) {
+				p.markObject(m.Nname.(*ir.Name))
+			}
+		}
+	}
+
+	// Recursively mark any types that can be produced given a
+	// value of type t: dereferencing a pointer; indexing or
+	// iterating over an array, slice, or map; receiving from a
+	// channel; accessing a struct field or interface method; or
+	// calling a function.
+	//
+	// Notably, we don't mark function parameter types, because
+	// the user already needs some way to construct values of
+	// those types.
+	switch t.Kind() {
+	case types.TPTR, types.TARRAY, types.TSLICE:
+		p.markType(t.Elem())
+
+	case types.TCHAN:
+		if t.ChanDir().CanRecv() {
+			p.markType(t.Elem())
+		}
+
+	case types.TMAP:
+		p.markType(t.Key())
+		p.markType(t.Elem())
+
+	case types.TSTRUCT:
+		for _, f := range t.FieldSlice() {
+			if types.IsExported(f.Sym.Name) || f.Embedded != 0 {
+				p.markType(f.Type)
+			}
+		}
+
+	case types.TFUNC:
+		for _, f := range t.Results().FieldSlice() {
+			p.markType(f.Type)
+		}
+
+	case types.TINTER:
+		// TODO(danscales) - will have to deal with the types in interface
+		// elements here when implemented in types2 and represented in types1.
+		for _, f := range t.AllMethods().Slice() {
+			if types.IsExported(f.Sym.Name) {
+				p.markType(f.Type)
+			}
+		}
+
+	case types.TTYPEPARAM:
+		// No other type that needs to be followed.
+	}
+}
+
+// markEmbed is similar to markType, but handles finding methods that
+// need to be re-exported because t can be embedded in user code
+// (possibly transitively).
+func (p *crawler) markEmbed(t *types.Type) {
+	if t.IsPtr() {
+		// Defined pointer type; not allowed to embed anyway.
+		if t.Sym() != nil {
+			return
+		}
+		t = t.Elem()
+	}
+
+	if t.IsInstantiatedGeneric() {
+		// Re-instantiated types don't add anything new, so don't follow them.
+		return
+	}
+
+	if p.embedded[t] {
+		return
+	}
+	p.embedded[t] = true
+
+	// If t is a defined type, then re-export all of its methods. Unlike
+	// in markType, we include even unexported methods here, because we
+	// still need to generate wrappers for them, even if the user can't
+	// refer to them directly.
+	if t.Sym() != nil && t.Kind() != types.TINTER {
+		for _, m := range t.Methods().Slice() {
+			p.markObject(m.Nname.(*ir.Name))
+		}
+	}
+
+	// If t is a struct, recursively visit its embedded fields.
+	if t.IsStruct() {
+		for _, f := range t.FieldSlice() {
+			if f.Embedded != 0 {
+				p.markEmbed(f.Type)
+			}
+		}
+	}
+}
+
+// markInlBody marks n's inline body for export and recursively
+// ensures all called functions are marked too.
+func (p *crawler) markInlBody(n *ir.Name) {
+	if n == nil {
+		return
+	}
+	if n.Op() != ir.ONAME || n.Class != ir.PFUNC {
+		base.Fatalf("markInlBody: unexpected %v, %v, %v", n, n.Op(), n.Class)
+	}
+	fn := n.Func
+	if fn == nil {
+		base.Fatalf("markInlBody: missing Func on %v", n)
+	}
+	if fn.Inl == nil {
+		return
+	}
+
+	if fn.ExportInline() {
+		return
+	}
+	fn.SetExportInline(true)
+
+	ImportedBody(fn)
+
+	var doFlood func(n ir.Node)
+	doFlood = func(n ir.Node) {
+		switch n.Op() {
+		case ir.OMETHEXPR, ir.ODOTMETH:
+			p.markInlBody(ir.MethodExprName(n))
+
+		case ir.ONAME:
+			n := n.(*ir.Name)
+			switch n.Class {
+			case ir.PFUNC:
+				p.markInlBody(n)
+				Export(n)
+			case ir.PEXTERN:
+				Export(n)
+			}
+			p.checkGenericType(n.Type())
+		case ir.OTYPE:
+			p.checkGenericType(n.Type())
+		case ir.OMETHVALUE:
+			// Okay, because we don't yet inline indirect
+			// calls to method values.
+		case ir.OCLOSURE:
+			// VisitList doesn't visit closure bodies, so force a
+			// recursive call to VisitList on the body of the closure.
+			ir.VisitList(n.(*ir.ClosureExpr).Func.Body, doFlood)
+		}
+	}
+
+	// Recursively identify all referenced functions for
+	// reexport. We want to include even non-called functions,
+	// because after inlining they might be callable.
+	ir.VisitList(fn.Inl.Body, doFlood)
+}
+
+// checkGenerictype ensures that we call markType() on any base generic type that
+// is written to the export file (even if not explicitly marked
+// for export), so its methods will be available for inlining if needed.
+func (p *crawler) checkGenericType(t *types.Type) {
+	if t != nil && t.HasTParam() {
+		if t.OrigSym != nil {
+			// Convert to the base generic type.
+			t = t.OrigSym.Def.Type()
+		}
+		p.markType(t)
+	}
+}
diff --git a/src/cmd/compile/internal/typecheck/dcl.go b/src/cmd/compile/internal/typecheck/dcl.go
index f3058d8811a..11e20f0f076 100644
--- a/src/cmd/compile/internal/typecheck/dcl.go
+++ b/src/cmd/compile/internal/typecheck/dcl.go
@@ -6,7 +6,7 @@ package typecheck
 
 import (
 	"fmt"
-	"strconv"
+	"sync"
 
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
@@ -106,7 +106,17 @@ func Export(n *ir.Name) {
 // Redeclared emits a diagnostic about symbol s being redeclared at pos.
 func Redeclared(pos src.XPos, s *types.Sym, where string) {
 	if !s.Lastlineno.IsKnown() {
-		pkgName := DotImportRefs[s.Def.(*ir.Ident)]
+		var pkgName *ir.PkgName
+		if s.Def == nil {
+			for id, pkg := range DotImportRefs {
+				if id.Sym().Name == s.Name {
+					pkgName = pkg
+					break
+				}
+			}
+		} else {
+			pkgName = DotImportRefs[s.Def.(*ir.Ident)]
+		}
 		base.ErrorfAt(pos, "%v redeclared %s\n"+
 			"\t%v: previous declaration during import %q", s, where, base.FmtPos(pkgName.Pos()), pkgName.Pkg.Path)
 	} else {
@@ -353,12 +363,10 @@ func funcargs(nt *ir.FuncType) {
 	}
 
 	// declare the out arguments.
-	gen := len(nt.Params)
-	for _, n := range nt.Results {
+	for i, n := range nt.Results {
 		if n.Sym == nil {
 			// Name so that escape analysis can track it. ~r stands for 'result'.
-			n.Sym = LookupNum("~r", gen)
-			gen++
+			n.Sym = LookupNum("~r", i)
 		}
 		if n.Sym.IsBlank() {
 			// Give it a name so we can assign to it during return. ~b stands for 'blank'.
@@ -367,8 +375,7 @@ func funcargs(nt *ir.FuncType) {
 			//	func g() int
 			// f is allowed to use a plain 'return' with no arguments, while g is not.
 			// So the two cases must be distinguished.
-			n.Sym = LookupNum("~b", gen)
-			gen++
+			n.Sym = LookupNum("~b", i)
 		}
 
 		funcarg(n, ir.PPARAMOUT)
@@ -421,6 +428,7 @@ func TempAt(pos src.XPos, curfn *ir.Func, t *types.Type) *ir.Name {
 	n := ir.NewNameAt(pos, s)
 	s.Def = n
 	n.SetType(t)
+	n.SetTypecheck(1)
 	n.Class = ir.PAUTO
 	n.SetEsc(ir.EscNever)
 	n.Curfn = curfn
@@ -433,15 +441,39 @@ func TempAt(pos src.XPos, curfn *ir.Func, t *types.Type) *ir.Name {
 	return n
 }
 
+var (
+	autotmpnamesmu sync.Mutex
+	autotmpnames   []string
+)
+
 // autotmpname returns the name for an autotmp variable numbered n.
 func autotmpname(n int) string {
-	// Give each tmp a different name so that they can be registerized.
-	// Add a preceding . to avoid clashing with legal names.
-	const prefix = ".autotmp_"
-	// Start with a buffer big enough to hold a large n.
-	b := []byte(prefix + "      ")[:len(prefix)]
-	b = strconv.AppendInt(b, int64(n), 10)
-	return types.InternString(b)
+	autotmpnamesmu.Lock()
+	defer autotmpnamesmu.Unlock()
+
+	// Grow autotmpnames, if needed.
+	if n >= len(autotmpnames) {
+		autotmpnames = append(autotmpnames, make([]string, n+1-len(autotmpnames))...)
+		autotmpnames = autotmpnames[:cap(autotmpnames)]
+	}
+
+	s := autotmpnames[n]
+	if s == "" {
+		// Give each tmp a different name so that they can be registerized.
+		// Add a preceding . to avoid clashing with legal names.
+		prefix := ".autotmp_%d"
+
+		// In quirks mode, pad out the number to stabilize variable
+		// sorting. This ensures autotmps 8 and 9 sort the same way even
+		// if they get renumbered to 9 and 10, respectively.
+		if base.Debug.UnifiedQuirks != 0 {
+			prefix = ".autotmp_%06d"
+		}
+
+		s = fmt.Sprintf(prefix, n)
+		autotmpnames[n] = s
+	}
+	return s
 }
 
 // f is method type, with receiver.
diff --git a/src/cmd/compile/internal/typecheck/export.go b/src/cmd/compile/internal/typecheck/export.go
index 63d0a1ec6c6..30726d4327f 100644
--- a/src/cmd/compile/internal/typecheck/export.go
+++ b/src/cmd/compile/internal/typecheck/export.go
@@ -15,22 +15,22 @@ import (
 
 // importalias declares symbol s as an imported type alias with type t.
 // ipkg is the package being imported
-func importalias(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
-	return importobj(ipkg, pos, s, ir.OTYPE, ir.PEXTERN, t)
+func importalias(pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
+	return importobj(pos, s, ir.OTYPE, ir.PEXTERN, t)
 }
 
 // importconst declares symbol s as an imported constant with type t and value val.
 // ipkg is the package being imported
-func importconst(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type, val constant.Value) *ir.Name {
-	n := importobj(ipkg, pos, s, ir.OLITERAL, ir.PEXTERN, t)
+func importconst(pos src.XPos, s *types.Sym, t *types.Type, val constant.Value) *ir.Name {
+	n := importobj(pos, s, ir.OLITERAL, ir.PEXTERN, t)
 	n.SetVal(val)
 	return n
 }
 
 // importfunc declares symbol s as an imported function with type t.
 // ipkg is the package being imported
-func importfunc(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
-	n := importobj(ipkg, pos, s, ir.ONAME, ir.PFUNC, t)
+func importfunc(pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
+	n := importobj(pos, s, ir.ONAME, ir.PFUNC, t)
 	n.Func = ir.NewFunc(pos)
 	n.Func.Nname = n
 	return n
@@ -38,8 +38,8 @@ func importfunc(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type) *ir.
 
 // importobj declares symbol s as an imported object representable by op.
 // ipkg is the package being imported
-func importobj(ipkg *types.Pkg, pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Class, t *types.Type) *ir.Name {
-	n := importsym(ipkg, pos, s, op, ctxt)
+func importobj(pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Class, t *types.Type) *ir.Name {
+	n := importsym(pos, s, op, ctxt)
 	n.SetType(t)
 	if ctxt == ir.PFUNC {
 		n.Sym().SetFunc(true)
@@ -47,7 +47,7 @@ func importobj(ipkg *types.Pkg, pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Cl
 	return n
 }
 
-func importsym(ipkg *types.Pkg, pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Class) *ir.Name {
+func importsym(pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Class) *ir.Name {
 	if n := s.PkgDef(); n != nil {
 		base.Fatalf("importsym of symbol that already exists: %v", n)
 	}
@@ -61,14 +61,14 @@ func importsym(ipkg *types.Pkg, pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Cl
 // importtype returns the named type declared by symbol s.
 // If no such type has been declared yet, a forward declaration is returned.
 // ipkg is the package being imported
-func importtype(ipkg *types.Pkg, pos src.XPos, s *types.Sym) *ir.Name {
-	n := importsym(ipkg, pos, s, ir.OTYPE, ir.PEXTERN)
+func importtype(pos src.XPos, s *types.Sym) *ir.Name {
+	n := importsym(pos, s, ir.OTYPE, ir.PEXTERN)
 	n.SetType(types.NewNamed(n))
 	return n
 }
 
 // importvar declares symbol s as an imported variable with type t.
 // ipkg is the package being imported
-func importvar(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
-	return importobj(ipkg, pos, s, ir.ONAME, ir.PEXTERN, t)
+func importvar(pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
+	return importobj(pos, s, ir.ONAME, ir.PEXTERN, t)
 }
diff --git a/src/cmd/compile/internal/typecheck/expr.go b/src/cmd/compile/internal/typecheck/expr.go
index 24d141e8a2c..7e974dfda86 100644
--- a/src/cmd/compile/internal/typecheck/expr.go
+++ b/src/cmd/compile/internal/typecheck/expr.go
@@ -311,14 +311,23 @@ func tcCompLit(n *ir.CompLitExpr) (res ir.Node) {
 
 				f := t.Field(i)
 				s := f.Sym
-				if s != nil && !types.IsExported(s.Name) && s.Pkg != types.LocalPkg {
-					base.Errorf("implicit assignment of unexported field '%s' in %v literal", s.Name, t)
+
+				// Do the test for assigning to unexported fields.
+				// But if this is an instantiated function, then
+				// the function has already been typechecked. In
+				// that case, don't do the test, since it can fail
+				// for the closure structs created in
+				// walkClosure(), because the instantiated
+				// function is compiled as if in the source
+				// package of the generic function.
+				if !(ir.CurFunc != nil && strings.Index(ir.CurFunc.Nname.Sym().Name, "[") >= 0) {
+					if s != nil && !types.IsExported(s.Name) && s.Pkg != types.LocalPkg {
+						base.Errorf("implicit assignment of unexported field '%s' in %v literal", s.Name, t)
+					}
 				}
 				// No pushtype allowed here. Must name fields for that.
 				n1 = AssignConv(n1, f.Type, "field value")
-				sk := ir.NewStructKeyExpr(base.Pos, f.Sym, n1)
-				sk.Offset = f.Offset
-				ls[i] = sk
+				ls[i] = ir.NewStructKeyExpr(base.Pos, f, n1)
 			}
 			if len(ls) < t.NumFields() {
 				base.Errorf("too few values in %v", n)
@@ -328,77 +337,33 @@ func tcCompLit(n *ir.CompLitExpr) (res ir.Node) {
 
 			// keyed list
 			ls := n.List
-			for i, l := range ls {
-				ir.SetPos(l)
+			for i, n := range ls {
+				ir.SetPos(n)
 
-				if l.Op() == ir.OKEY {
-					kv := l.(*ir.KeyExpr)
-					key := kv.Key
-
-					// Sym might have resolved to name in other top-level
-					// package, because of import dot. Redirect to correct sym
-					// before we do the lookup.
-					s := key.Sym()
-					if id, ok := key.(*ir.Ident); ok && DotImportRefs[id] != nil {
-						s = Lookup(s.Name)
-					}
-
-					// An OXDOT uses the Sym field to hold
-					// the field to the right of the dot,
-					// so s will be non-nil, but an OXDOT
-					// is never a valid struct literal key.
-					if s == nil || s.Pkg != types.LocalPkg || key.Op() == ir.OXDOT || s.IsBlank() {
-						base.Errorf("invalid field name %v in struct initializer", key)
-						continue
-					}
-
-					l = ir.NewStructKeyExpr(l.Pos(), s, kv.Value)
-					ls[i] = l
-				}
-
-				if l.Op() != ir.OSTRUCTKEY {
-					if !errored {
-						base.Errorf("mixture of field:value and value initializers")
-						errored = true
-					}
-					ls[i] = Expr(ls[i])
-					continue
-				}
-				l := l.(*ir.StructKeyExpr)
-
-				f := Lookdot1(nil, l.Field, t, t.Fields(), 0)
-				if f == nil {
-					if ci := Lookdot1(nil, l.Field, t, t.Fields(), 2); ci != nil { // Case-insensitive lookup.
-						if visible(ci.Sym) {
-							base.Errorf("unknown field '%v' in struct literal of type %v (but does have %v)", l.Field, t, ci.Sym)
-						} else if nonexported(l.Field) && l.Field.Name == ci.Sym.Name { // Ensure exactness before the suggestion.
-							base.Errorf("cannot refer to unexported field '%v' in struct literal of type %v", l.Field, t)
-						} else {
-							base.Errorf("unknown field '%v' in struct literal of type %v", l.Field, t)
+				sk, ok := n.(*ir.StructKeyExpr)
+				if !ok {
+					kv, ok := n.(*ir.KeyExpr)
+					if !ok {
+						if !errored {
+							base.Errorf("mixture of field:value and value initializers")
+							errored = true
 						}
+						ls[i] = Expr(n)
 						continue
 					}
-					var f *types.Field
-					p, _ := dotpath(l.Field, t, &f, true)
-					if p == nil || f.IsMethod() {
-						base.Errorf("unknown field '%v' in struct literal of type %v", l.Field, t)
+
+					sk = tcStructLitKey(t, kv)
+					if sk == nil {
 						continue
 					}
-					// dotpath returns the parent embedded types in reverse order.
-					var ep []string
-					for ei := len(p) - 1; ei >= 0; ei-- {
-						ep = append(ep, p[ei].field.Sym.Name)
-					}
-					ep = append(ep, l.Field.Name)
-					base.Errorf("cannot use promoted field %v in struct literal of type %v", strings.Join(ep, "."), t)
-					continue
+
+					fielddup(sk.Sym().Name, hash)
 				}
-				fielddup(f.Sym.Name, hash)
-				l.Offset = f.Offset
 
 				// No pushtype allowed here. Tried and rejected.
-				l.Value = Expr(l.Value)
-				l.Value = AssignConv(l.Value, f.Type, "field value")
+				sk.Value = Expr(sk.Value)
+				sk.Value = AssignConv(sk.Value, sk.Field.Type, "field value")
+				ls[i] = sk
 			}
 		}
 
@@ -409,6 +374,60 @@ func tcCompLit(n *ir.CompLitExpr) (res ir.Node) {
 	return n
 }
 
+// tcStructLitKey typechecks an OKEY node that appeared within a
+// struct literal.
+func tcStructLitKey(typ *types.Type, kv *ir.KeyExpr) *ir.StructKeyExpr {
+	key := kv.Key
+
+	// Sym might have resolved to name in other top-level
+	// package, because of import dot. Redirect to correct sym
+	// before we do the lookup.
+	sym := key.Sym()
+	if id, ok := key.(*ir.Ident); ok && DotImportRefs[id] != nil {
+		sym = Lookup(sym.Name)
+	}
+
+	// An OXDOT uses the Sym field to hold
+	// the field to the right of the dot,
+	// so s will be non-nil, but an OXDOT
+	// is never a valid struct literal key.
+	if sym == nil || sym.Pkg != types.LocalPkg || key.Op() == ir.OXDOT || sym.IsBlank() {
+		base.Errorf("invalid field name %v in struct initializer", key)
+		return nil
+	}
+
+	if f := Lookdot1(nil, sym, typ, typ.Fields(), 0); f != nil {
+		return ir.NewStructKeyExpr(kv.Pos(), f, kv.Value)
+	}
+
+	if ci := Lookdot1(nil, sym, typ, typ.Fields(), 2); ci != nil { // Case-insensitive lookup.
+		if visible(ci.Sym) {
+			base.Errorf("unknown field '%v' in struct literal of type %v (but does have %v)", sym, typ, ci.Sym)
+		} else if nonexported(sym) && sym.Name == ci.Sym.Name { // Ensure exactness before the suggestion.
+			base.Errorf("cannot refer to unexported field '%v' in struct literal of type %v", sym, typ)
+		} else {
+			base.Errorf("unknown field '%v' in struct literal of type %v", sym, typ)
+		}
+		return nil
+	}
+
+	var f *types.Field
+	p, _ := dotpath(sym, typ, &f, true)
+	if p == nil || f.IsMethod() {
+		base.Errorf("unknown field '%v' in struct literal of type %v", sym, typ)
+		return nil
+	}
+
+	// dotpath returns the parent embedded types in reverse order.
+	var ep []string
+	for ei := len(p) - 1; ei >= 0; ei-- {
+		ep = append(ep, p[ei].field.Sym.Name)
+	}
+	ep = append(ep, sym.Name)
+	base.Errorf("cannot use promoted field %v in struct literal of type %v", strings.Join(ep, "."), typ)
+	return nil
+}
+
 // tcConv typechecks an OCONV node.
 func tcConv(n *ir.ConvExpr) ir.Node {
 	types.CheckSize(n.Type()) // ensure width is calculated for backend
@@ -522,8 +541,8 @@ func tcDot(n *ir.SelectorExpr, top int) ir.Node {
 	}
 
 	if (n.Op() == ir.ODOTINTER || n.Op() == ir.ODOTMETH) && top&ctxCallee == 0 {
-		n.SetOp(ir.OCALLPART)
-		n.SetType(MethodValueWrapper(n).Type())
+		n.SetOp(ir.OMETHVALUE)
+		n.SetType(NewMethodType(n.Type(), nil))
 	}
 	return n
 }
diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index f381e1dbdc4..7dec65c1d68 100644
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -8,28 +8,29 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
+	"cmd/internal/src"
 
 	"fmt"
 	"go/constant"
 	"go/token"
 )
 
-// package all the arguments that match a ... T parameter into a []T.
-func MakeDotArgs(typ *types.Type, args []ir.Node) ir.Node {
+// MakeDotArgs package all the arguments that match a ... T parameter into a []T.
+func MakeDotArgs(pos src.XPos, typ *types.Type, args []ir.Node) ir.Node {
 	var n ir.Node
 	if len(args) == 0 {
-		n = NodNil()
+		n = ir.NewNilExpr(pos)
 		n.SetType(typ)
 	} else {
-		lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
-		lit.List.Append(args...)
+		args = append([]ir.Node(nil), args...)
+		lit := ir.NewCompLitExpr(pos, ir.OCOMPLIT, ir.TypeNode(typ), args)
 		lit.SetImplicit(true)
 		n = lit
 	}
 
 	n = Expr(n)
 	if n.Type() == nil {
-		base.Fatalf("mkdotargslice: typecheck failed")
+		base.FatalfAt(pos, "mkdotargslice: typecheck failed")
 	}
 	return n
 }
@@ -47,7 +48,7 @@ func FixVariadicCall(call *ir.CallExpr) {
 
 	args := call.Args
 	extra := args[vi:]
-	slice := MakeDotArgs(vt, extra)
+	slice := MakeDotArgs(call.Pos(), vt, extra)
 	for i := range extra {
 		extra[i] = nil // allow GC
 	}
@@ -56,6 +57,25 @@ func FixVariadicCall(call *ir.CallExpr) {
 	call.IsDDD = true
 }
 
+// FixMethodCall rewrites a method call t.M(...) into a function call T.M(t, ...).
+func FixMethodCall(call *ir.CallExpr) {
+	if call.X.Op() != ir.ODOTMETH {
+		return
+	}
+
+	dot := call.X.(*ir.SelectorExpr)
+
+	fn := Expr(ir.NewSelectorExpr(dot.Pos(), ir.OXDOT, ir.TypeNode(dot.X.Type()), dot.Selection.Sym))
+
+	args := make([]ir.Node, 1+len(call.Args))
+	args[0] = dot.X
+	copy(args[1:], call.Args)
+
+	call.SetOp(ir.OCALLFUNC)
+	call.X = fn
+	call.Args = args
+}
+
 // ClosureType returns the struct type used to hold all the information
 // needed in the closure for clo (clo must be a OCLOSURE node).
 // The address of a variable of the returned type can be cast to a func.
@@ -73,8 +93,25 @@ func ClosureType(clo *ir.ClosureExpr) *types.Type {
 	// The information appears in the binary in the form of type descriptors;
 	// the struct is unnamed so that closures in multiple packages with the
 	// same struct type can share the descriptor.
+
+	// Make sure the .F field is in the same package as the rest of the
+	// fields. This deals with closures in instantiated functions, which are
+	// compiled as if from the source package of the generic function.
+	var pkg *types.Pkg
+	if len(clo.Func.ClosureVars) == 0 {
+		pkg = types.LocalPkg
+	} else {
+		for _, v := range clo.Func.ClosureVars {
+			if pkg == nil {
+				pkg = v.Sym().Pkg
+			} else if pkg != v.Sym().Pkg {
+				base.Fatalf("Closure variables from multiple packages")
+			}
+		}
+	}
+
 	fields := []*types.Field{
-		types.NewField(base.Pos, Lookup(".F"), types.Types[types.TUINTPTR]),
+		types.NewField(base.Pos, pkg.Lookup(".F"), types.Types[types.TUINTPTR]),
 	}
 	for _, v := range clo.Func.ClosureVars {
 		typ := v.Type()
@@ -88,10 +125,10 @@ func ClosureType(clo *ir.ClosureExpr) *types.Type {
 	return typ
 }
 
-// PartialCallType returns the struct type used to hold all the information
-// needed in the closure for n (n must be a OCALLPART node).
-// The address of a variable of the returned type can be cast to a func.
-func PartialCallType(n *ir.SelectorExpr) *types.Type {
+// MethodValueType returns the struct type used to hold all the information
+// needed in the closure for a OMETHVALUE node. The address of a variable of
+// the returned type can be cast to a func.
+func MethodValueType(n *ir.SelectorExpr) *types.Type {
 	t := types.NewStruct(types.NoPkg, []*types.Field{
 		types.NewField(base.Pos, Lookup("F"), types.Types[types.TUINTPTR]),
 		types.NewField(base.Pos, Lookup("R"), n.X.Type()),
@@ -181,153 +218,38 @@ func fnpkg(fn *ir.Name) *types.Pkg {
 	return fn.Sym().Pkg
 }
 
-// ClosureName generates a new unique name for a closure within
-// outerfunc.
-func ClosureName(outerfunc *ir.Func) *types.Sym {
-	outer := "glob."
-	prefix := "func"
-	gen := &globClosgen
-
-	if outerfunc != nil {
-		if outerfunc.OClosure != nil {
-			prefix = ""
-		}
-
-		outer = ir.FuncName(outerfunc)
-
-		// There may be multiple functions named "_". In those
-		// cases, we can't use their individual Closgens as it
-		// would lead to name clashes.
-		if !ir.IsBlank(outerfunc.Nname) {
-			gen = &outerfunc.Closgen
-		}
-	}
-
-	*gen++
-	return Lookup(fmt.Sprintf("%s.%s%d", outer, prefix, *gen))
-}
-
-// globClosgen is like Func.Closgen, but for the global scope.
-var globClosgen int32
-
-// MethodValueWrapper returns the DCLFUNC node representing the
-// wrapper function (*-fm) needed for the given method value. If the
-// wrapper function hasn't already been created yet, it's created and
-// added to Target.Decls.
-//
-// TODO(mdempsky): Move into walk. This isn't part of type checking.
-func MethodValueWrapper(dot *ir.SelectorExpr) *ir.Func {
-	if dot.Op() != ir.OCALLPART {
-		base.Fatalf("MethodValueWrapper: unexpected %v (%v)", dot, dot.Op())
-	}
-
-	t0 := dot.Type()
-	meth := dot.Sel
-	rcvrtype := dot.X.Type()
-	sym := ir.MethodSymSuffix(rcvrtype, meth, "-fm")
-
-	if sym.Uniq() {
-		return sym.Def.(*ir.Func)
-	}
-	sym.SetUniq(true)
-
-	savecurfn := ir.CurFunc
-	saveLineNo := base.Pos
-	ir.CurFunc = nil
-
-	// Set line number equal to the line number where the method is declared.
-	if pos := dot.Selection.Pos; pos.IsKnown() {
-		base.Pos = pos
-	}
-	// Note: !dot.Selection.Pos.IsKnown() happens for method expressions where
-	// the method is implicitly declared. The Error method of the
-	// built-in error type is one such method.  We leave the line
-	// number at the use of the method expression in this
-	// case. See issue 29389.
-
-	tfn := ir.NewFuncType(base.Pos, nil,
-		NewFuncParams(t0.Params(), true),
-		NewFuncParams(t0.Results(), false))
-
-	fn := DeclFunc(sym, tfn)
-	fn.SetDupok(true)
-	fn.SetNeedctxt(true)
-	fn.SetWrapper(true)
-
-	// Declare and initialize variable holding receiver.
-	ptr := ir.NewNameAt(base.Pos, Lookup(".this"))
-	ptr.Class = ir.PAUTOHEAP
-	ptr.SetType(rcvrtype)
-	ptr.Curfn = fn
-	ptr.SetIsClosureVar(true)
-	ptr.SetByval(true)
-	fn.ClosureVars = append(fn.ClosureVars, ptr)
-
-	call := ir.NewCallExpr(base.Pos, ir.OCALL, ir.NewSelectorExpr(base.Pos, ir.OXDOT, ptr, meth), nil)
-	call.Args = ir.ParamNames(tfn.Type())
-	call.IsDDD = tfn.Type().IsVariadic()
-
-	var body ir.Node = call
-	if t0.NumResults() != 0 {
-		ret := ir.NewReturnStmt(base.Pos, nil)
-		ret.Results = []ir.Node{call}
-		body = ret
-	}
-
-	fn.Body = []ir.Node{body}
-	FinishFuncBody()
-
-	Func(fn)
-	// Need to typecheck the body of the just-generated wrapper.
-	// typecheckslice() requires that Curfn is set when processing an ORETURN.
-	ir.CurFunc = fn
-	Stmts(fn.Body)
-	sym.Def = fn
-	Target.Decls = append(Target.Decls, fn)
-	ir.CurFunc = savecurfn
-	base.Pos = saveLineNo
-
-	return fn
-}
-
 // tcClosure typechecks an OCLOSURE node. It also creates the named
 // function associated with the closure.
 // TODO: This creation of the named function should probably really be done in a
 // separate pass from type-checking.
-func tcClosure(clo *ir.ClosureExpr, top int) {
+func tcClosure(clo *ir.ClosureExpr, top int) ir.Node {
 	fn := clo.Func
+
+	// We used to allow IR builders to typecheck the underlying Func
+	// themselves, but that led to too much variety and inconsistency
+	// around who's responsible for naming the function, typechecking
+	// it, or adding it to Target.Decls.
+	//
+	// It's now all or nothing. Callers are still allowed to do these
+	// themselves, but then they assume responsibility for all of them.
+	if fn.Typecheck() == 1 {
+		base.FatalfAt(fn.Pos(), "underlying closure func already typechecked: %v", fn)
+	}
+
 	// Set current associated iota value, so iota can be used inside
 	// function in ConstSpec, see issue #22344
 	if x := getIotaValue(); x >= 0 {
 		fn.Iota = x
 	}
 
-	fn.SetClosureCalled(top&ctxCallee != 0)
-
-	// Do not typecheck fn twice, otherwise, we will end up pushing
-	// fn to Target.Decls multiple times, causing InitLSym called twice.
-	// See #30709
-	if fn.Typecheck() == 1 {
-		clo.SetType(fn.Type())
-		return
-	}
-
-	// Don't give a name and add to Target.Decls if we are typechecking an inlined
-	// body in ImportedBody(), since we only want to create the named function
-	// when the closure is actually inlined (and then we force a typecheck
-	// explicitly in (*inlsubst).node()).
-	if !inTypeCheckInl {
-		fn.Nname.SetSym(ClosureName(ir.CurFunc))
-		ir.MarkFunc(fn.Nname)
-	}
+	ir.NameClosure(clo, ir.CurFunc)
 	Func(fn)
-	clo.SetType(fn.Type())
 
 	// Type check the body now, but only if we're inside a function.
 	// At top level (in a variable initialization: curfn==nil) we're not
 	// ready to type check code yet; we'll check it later, because the
 	// underlying closure function we create is added to Target.Decls.
-	if ir.CurFunc != nil && clo.Type() != nil {
+	if ir.CurFunc != nil {
 		oldfn := ir.CurFunc
 		ir.CurFunc = fn
 		Stmts(fn.Body)
@@ -353,14 +275,17 @@ func tcClosure(clo *ir.ClosureExpr, top int) {
 	}
 	fn.ClosureVars = fn.ClosureVars[:out]
 
-	if base.Flag.W > 1 {
-		s := fmt.Sprintf("New closure func: %s", ir.FuncName(fn))
-		ir.Dump(s, fn)
-	}
-	if !inTypeCheckInl {
-		// Add function to Target.Decls once only when we give it a name
-		Target.Decls = append(Target.Decls, fn)
+	clo.SetType(fn.Type())
+
+	target := Target
+	if inTypeCheckInl {
+		// We're typechecking an imported function, so it's not actually
+		// part of Target. Skip adding it to Target.Decls so we don't
+		// compile it again.
+		target = nil
 	}
+
+	return ir.UseClosure(clo, target)
 }
 
 // type check function definition
@@ -390,10 +315,6 @@ func tcFunc(n *ir.Func) {
 
 // tcCall typechecks an OCALL node.
 func tcCall(n *ir.CallExpr, top int) ir.Node {
-	n.Use = ir.CallUseExpr
-	if top == ctxStmt {
-		n.Use = ir.CallUseStmt
-	}
 	Stmts(n.Init()) // imported rewritten f(g()) calls (#30907)
 	n.X = typecheck(n.X, ctxExpr|ctxType|ctxCallee)
 	if n.X.Diag() {
@@ -509,6 +430,7 @@ func tcCall(n *ir.CallExpr, top int) ir.Node {
 	}
 
 	typecheckaste(ir.OCALL, n.X, n.IsDDD, t.Params(), n.Args, func() string { return fmt.Sprintf("argument to %v", n.X) })
+	FixMethodCall(n)
 	if t.NumResults() == 0 {
 		return n
 	}
@@ -979,8 +901,29 @@ func tcRecover(n *ir.CallExpr) ir.Node {
 	return n
 }
 
+// tcRecoverFP typechecks an ORECOVERFP node.
+func tcRecoverFP(n *ir.CallExpr) ir.Node {
+	if len(n.Args) != 1 {
+		base.FatalfAt(n.Pos(), "wrong number of arguments: %v", n)
+	}
+
+	n.Args[0] = Expr(n.Args[0])
+	if !n.Args[0].Type().IsPtrShaped() {
+		base.FatalfAt(n.Pos(), "%L is not pointer shaped", n.Args[0])
+	}
+
+	n.SetType(types.Types[types.TINTER])
+	return n
+}
+
 // tcUnsafeAdd typechecks an OUNSAFEADD node.
 func tcUnsafeAdd(n *ir.BinaryExpr) *ir.BinaryExpr {
+	if !types.AllowsGoVersion(curpkg(), 1, 17) {
+		base.ErrorfVers("go1.17", "unsafe.Add")
+		n.SetType(nil)
+		return n
+	}
+
 	n.X = AssignConv(Expr(n.X), types.Types[types.TUNSAFEPTR], "argument to unsafe.Add")
 	n.Y = DefaultLit(Expr(n.Y), types.Types[types.TINT])
 	if n.X.Type() == nil || n.Y.Type() == nil {
@@ -997,6 +940,12 @@ func tcUnsafeAdd(n *ir.BinaryExpr) *ir.BinaryExpr {
 
 // tcUnsafeSlice typechecks an OUNSAFESLICE node.
 func tcUnsafeSlice(n *ir.BinaryExpr) *ir.BinaryExpr {
+	if !types.AllowsGoVersion(curpkg(), 1, 17) {
+		base.ErrorfVers("go1.17", "unsafe.Slice")
+		n.SetType(nil)
+		return n
+	}
+
 	n.X = Expr(n.X)
 	n.Y = Expr(n.Y)
 	if n.X.Type() == nil || n.Y.Type() == nil {
@@ -1006,7 +955,14 @@ func tcUnsafeSlice(n *ir.BinaryExpr) *ir.BinaryExpr {
 	t := n.X.Type()
 	if !t.IsPtr() {
 		base.Errorf("first argument to unsafe.Slice must be pointer; have %L", t)
+	} else if t.Elem().NotInHeap() {
+		// TODO(mdempsky): This can be relaxed, but should only affect the
+		// Go runtime itself. End users should only see //go:notinheap
+		// types due to incomplete C structs in cgo, and those types don't
+		// have a meaningful size anyway.
+		base.Errorf("unsafe.Slice of incomplete (or unallocatable) type not allowed")
 	}
+
 	if !checkunsafeslice(&n.Y) {
 		n.SetType(nil)
 		return n
diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go
index 64d68ef6255..75b4931c310 100644
--- a/src/cmd/compile/internal/typecheck/iexport.go
+++ b/src/cmd/compile/internal/typecheck/iexport.go
@@ -173,6 +173,8 @@
 //     }
 //
 //
+//  TODO(danscales): fill in doc for 'type TypeParamType' and 'type InstType'
+//
 //     type Signature struct {
 //         Params   []Param
 //         Results  []Param
@@ -202,7 +204,6 @@
 package typecheck
 
 import (
-	"bufio"
 	"bytes"
 	"crypto/md5"
 	"encoding/binary"
@@ -221,9 +222,18 @@ import (
 )
 
 // Current indexed export format version. Increase with each format change.
-// 1: added column details to Pos
 // 0: Go1.11 encoding
-const iexportVersion = 1
+// 1: added column details to Pos
+// 2: added information for generic function/types (currently unstable)
+const (
+	iexportVersionGo1_11 = 0
+	iexportVersionPosCol = 1
+	// TODO: before release, change this back to 2.  Kept at previous version
+	// for now (for testing).
+	iexportVersionGenerics = iexportVersionPosCol
+
+	iexportVersionCurrent = iexportVersionGenerics
+)
 
 // predeclReserved is the number of type offsets reserved for types
 // implicitly declared in the universe block.
@@ -244,6 +254,9 @@ const (
 	signatureType
 	structType
 	interfaceType
+	typeParamType
+	instType
+	unionType
 )
 
 const (
@@ -251,13 +264,22 @@ const (
 	magic = 0x6742937dc293105
 )
 
-func WriteExports(out *bufio.Writer) {
+// WriteExports writes the indexed export format to out. If extensions
+// is true, then the compiler-only extensions are included.
+func WriteExports(out io.Writer, extensions bool) {
+	if extensions {
+		// If we're exporting inline bodies, invoke the crawler to mark
+		// which bodies to include.
+		crawlExports(Target.Exports)
+	}
+
 	p := iexporter{
 		allPkgs:     map[*types.Pkg]bool{},
 		stringIndex: map[string]uint64{},
 		declIndex:   map[*types.Sym]uint64{},
 		inlineIndex: map[*types.Sym]uint64{},
 		typIndex:    map[*types.Type]uint64{},
+		extensions:  extensions,
 	}
 
 	for i, pt := range predeclared() {
@@ -293,7 +315,7 @@ func WriteExports(out *bufio.Writer) {
 	// Assemble header.
 	var hdr intWriter
 	hdr.WriteByte('i')
-	hdr.uint64(iexportVersion)
+	hdr.uint64(iexportVersionCurrent)
 	hdr.uint64(uint64(p.strings.Len()))
 	hdr.uint64(dataLen)
 
@@ -379,6 +401,8 @@ type iexporter struct {
 	declIndex   map[*types.Sym]uint64
 	inlineIndex map[*types.Sym]uint64
 	typIndex    map[*types.Type]uint64
+
+	extensions bool
 }
 
 // stringOff returns the offset of s within the string section.
@@ -449,7 +473,9 @@ func (p *iexporter) doDecl(n *ir.Name) {
 			w.tag('V')
 			w.pos(n.Pos())
 			w.typ(n.Type())
-			w.varExt(n)
+			if w.p.extensions {
+				w.varExt(n)
+			}
 
 		case ir.PFUNC:
 			if ir.IsMethod(n) {
@@ -457,10 +483,25 @@ func (p *iexporter) doDecl(n *ir.Name) {
 			}
 
 			// Function.
-			w.tag('F')
+			if n.Type().TParams().NumFields() == 0 {
+				w.tag('F')
+			} else {
+				w.tag('G')
+			}
 			w.pos(n.Pos())
+			// The tparam list of the function type is the
+			// declaration of the type params. So, write out the type
+			// params right now. Then those type params will be
+			// referenced via their type offset (via typOff) in all
+			// other places in the signature and function that they
+			// are used.
+			if n.Type().TParams().NumFields() > 0 {
+				w.tparamList(n.Type().TParams().FieldSlice())
+			}
 			w.signature(n.Type())
-			w.funcExt(n)
+			if w.p.extensions {
+				w.funcExt(n)
+			}
 
 		default:
 			base.Fatalf("unexpected class: %v, %v", n, n.Class)
@@ -476,10 +517,25 @@ func (p *iexporter) doDecl(n *ir.Name) {
 		w.tag('C')
 		w.pos(n.Pos())
 		w.value(n.Type(), n.Val())
-		w.constExt(n)
+		if w.p.extensions {
+			w.constExt(n)
+		}
 
 	case ir.OTYPE:
-		if types.IsDotAlias(n.Sym()) {
+		if n.Type().IsTypeParam() && n.Type().Underlying() == n.Type() {
+			// Even though it has local scope, a typeparam requires a
+			// declaration via its package and unique name, because it
+			// may be referenced within its type bound during its own
+			// definition.
+			w.tag('P')
+			// A typeparam has a name, and has a type bound rather
+			// than an underlying type.
+			w.pos(n.Pos())
+			w.typ(n.Type().Bound())
+			break
+		}
+
+		if n.Alias() {
 			// Alias.
 			w.tag('A')
 			w.pos(n.Pos())
@@ -488,9 +544,18 @@ func (p *iexporter) doDecl(n *ir.Name) {
 		}
 
 		// Defined type.
-		w.tag('T')
+		if len(n.Type().RParams()) == 0 {
+			w.tag('T')
+		} else {
+			w.tag('U')
+		}
 		w.pos(n.Pos())
 
+		if len(n.Type().RParams()) > 0 {
+			// Export type parameters, if any, needed for this type
+			w.typeList(n.Type().RParams())
+		}
+
 		underlying := n.Type().Underlying()
 		if underlying == types.ErrorType.Underlying() {
 			// For "type T error", use error as the
@@ -505,22 +570,29 @@ func (p *iexporter) doDecl(n *ir.Name) {
 
 		t := n.Type()
 		if t.IsInterface() {
-			w.typeExt(t)
+			if w.p.extensions {
+				w.typeExt(t)
+			}
 			break
 		}
 
-		ms := t.Methods()
-		w.uint64(uint64(ms.Len()))
-		for _, m := range ms.Slice() {
+		// Sort methods, for consistency with types2.
+		methods := append([]*types.Field(nil), t.Methods().Slice()...)
+		sort.Sort(types.MethodsByName(methods))
+
+		w.uint64(uint64(len(methods)))
+		for _, m := range methods {
 			w.pos(m.Pos)
 			w.selector(m.Sym)
 			w.param(m.Type.Recv())
 			w.signature(m.Type)
 		}
 
-		w.typeExt(t)
-		for _, m := range ms.Slice() {
-			w.methExt(m)
+		if w.p.extensions {
+			w.typeExt(t)
+			for _, m := range methods {
+				w.methExt(m)
+			}
 		}
 
 	default:
@@ -803,8 +875,46 @@ func (w *exportWriter) startType(k itag) {
 }
 
 func (w *exportWriter) doTyp(t *types.Type) {
-	if t.Sym() != nil {
-		if t.Sym().Pkg == types.BuiltinPkg || t.Sym().Pkg == ir.Pkgs.Unsafe {
+	s := t.Sym()
+	if s != nil && t.OrigSym != nil {
+		assert(base.Flag.G > 0)
+		// This is an instantiated type - could be a re-instantiation like
+		// Value[T2] or a full instantiation like Value[int].
+		if strings.Index(s.Name, "[") < 0 {
+			base.Fatalf("incorrect name for instantiated type")
+		}
+		w.startType(instType)
+		w.pos(t.Pos())
+		// Export the type arguments for the instantiated type. The
+		// instantiated type could be in a method header (e.g. "func (v
+		// *Value[T2]) set (...) { ... }"), so the type args are "new"
+		// typeparams. Or the instantiated type could be in a
+		// function/method body, so the type args are either concrete
+		// types or existing typeparams from the function/method header.
+		w.typeList(t.RParams())
+		// Export a reference to the base type.
+		baseType := t.OrigSym.Def.(*ir.Name).Type()
+		w.typ(baseType)
+		return
+	}
+
+	// The 't.Underlying() == t' check is to confirm this is a base typeparam
+	// type, rather than a defined type with typeparam underlying type, like:
+	// type orderedAbs[T any] T
+	if t.IsTypeParam() && t.Underlying() == t {
+		assert(base.Flag.G > 0)
+		if s.Pkg == types.BuiltinPkg || s.Pkg == ir.Pkgs.Unsafe {
+			base.Fatalf("builtin type missing from typIndex: %v", t)
+		}
+		// Write out the first use of a type param as a qualified ident.
+		// This will force a "declaration" of the type param.
+		w.startType(typeParamType)
+		w.qualifiedIdent(t.Obj().(*ir.Name))
+		return
+	}
+
+	if s != nil {
+		if s.Pkg == types.BuiltinPkg || s.Pkg == ir.Pkgs.Unsafe {
 			base.Fatalf("builtin type missing from typIndex: %v", t)
 		}
 
@@ -865,6 +975,12 @@ func (w *exportWriter) doTyp(t *types.Type) {
 			}
 		}
 
+		// Sort methods and embedded types, for consistency with types2.
+		// Note: embedded types may be anonymous, and types2 sorts them
+		// with sort.Stable too.
+		sort.Sort(types.MethodsByName(methods))
+		sort.Stable(types.EmbeddedsByName(embeddeds))
+
 		w.startType(interfaceType)
 		w.setPkg(t.Pkg(), true)
 
@@ -881,6 +997,19 @@ func (w *exportWriter) doTyp(t *types.Type) {
 			w.signature(f.Type)
 		}
 
+	case types.TUNION:
+		assert(base.Flag.G > 0)
+		// TODO(danscales): possibly put out the tilde bools in more
+		// compact form.
+		w.startType(unionType)
+		nt := t.NumTerms()
+		w.uint64(uint64(nt))
+		for i := 0; i < nt; i++ {
+			typ, tilde := t.Term(i)
+			w.bool(tilde)
+			w.typ(typ)
+		}
+
 	default:
 		base.Fatalf("unexpected type: %v", t)
 	}
@@ -906,6 +1035,23 @@ func (w *exportWriter) signature(t *types.Type) {
 	}
 }
 
+func (w *exportWriter) typeList(ts []*types.Type) {
+	w.uint64(uint64(len(ts)))
+	for _, rparam := range ts {
+		w.typ(rparam)
+	}
+}
+
+func (w *exportWriter) tparamList(fs []*types.Field) {
+	w.uint64(uint64(len(fs)))
+	for _, f := range fs {
+		if !f.Type.IsTypeParam() {
+			base.Fatalf("unexpected non-typeparam")
+		}
+		w.typ(f.Type)
+	}
+}
+
 func (w *exportWriter) paramList(fs []*types.Field) {
 	w.uint64(uint64(len(fs)))
 	for _, f := range fs {
@@ -948,26 +1094,50 @@ func constTypeOf(typ *types.Type) constant.Kind {
 }
 
 func (w *exportWriter) value(typ *types.Type, v constant.Value) {
-	ir.AssertValidTypeForConst(typ, v)
 	w.typ(typ)
+	var kind constant.Kind
+	var valType *types.Type
 
-	// Each type has only one admissible constant representation,
-	// so we could type switch directly on v.U here. However,
-	// switching on the type increases symmetry with import logic
-	// and provides a useful consistency check.
+	if typ.IsTypeParam() {
+		// A constant will have a TYPEPARAM type if it appears in a place
+		// where it must match that typeparam type (e.g. in a binary
+		// operation with a variable of that typeparam type). If so, then
+		// we must write out its actual constant kind as well, so its
+		// constant val can be read in properly during import.
+		kind = v.Kind()
+		w.int64(int64(kind))
 
-	switch constTypeOf(typ) {
+		switch kind {
+		case constant.Int:
+			valType = types.Types[types.TINT64]
+		case constant.Float:
+			valType = types.Types[types.TFLOAT64]
+		case constant.Complex:
+			valType = types.Types[types.TCOMPLEX128]
+		}
+	} else {
+		ir.AssertValidTypeForConst(typ, v)
+		kind = constTypeOf(typ)
+		valType = typ
+	}
+
+	// Each type has only one admissible constant representation, so we could
+	// type switch directly on v.Kind() here. However, switching on the type
+	// (in the non-typeparam case) increases symmetry with import logic and
+	// provides a useful consistency check.
+
+	switch kind {
 	case constant.Bool:
 		w.bool(constant.BoolVal(v))
 	case constant.String:
 		w.string(constant.StringVal(v))
 	case constant.Int:
-		w.mpint(v, typ)
+		w.mpint(v, valType)
 	case constant.Float:
-		w.mpfloat(v, typ)
+		w.mpfloat(v, valType)
 	case constant.Complex:
-		w.mpfloat(constant.Real(v), typ)
-		w.mpfloat(constant.Imag(v), typ)
+		w.mpfloat(constant.Real(v), valType)
+		w.mpfloat(constant.Imag(v), valType)
 	}
 }
 
@@ -1185,10 +1355,14 @@ func (w *exportWriter) funcExt(n *ir.Name) {
 		}
 	}
 
-	// Inline body.
+	// Write out inline body or body of a generic function/method.
+	if n.Type().HasTParam() && n.Func.Body != nil && n.Func.Inl == nil {
+		base.FatalfAt(n.Pos(), "generic function is not marked inlineable")
+	}
 	if n.Func.Inl != nil {
 		w.uint64(1 + uint64(n.Func.Inl.Cost))
-		if n.Func.ExportInline() {
+		w.bool(n.Func.Inl.CanDelayResults)
+		if n.Func.ExportInline() || n.Type().HasTParam() {
 			w.p.doInline(n)
 		}
 
@@ -1432,7 +1606,12 @@ func (w *exportWriter) commList(cases []*ir.CommClause) {
 	w.uint64(uint64(len(cases)))
 	for _, cas := range cases {
 		w.pos(cas.Pos())
-		w.node(cas.Comm)
+		defaultCase := cas.Comm == nil
+		w.bool(defaultCase)
+		if !defaultCase {
+			// Only call w.node for non-default cause (cas.Comm is non-nil)
+			w.node(cas.Comm)
+		}
 		w.stmtList(cas.Body)
 	}
 }
@@ -1460,7 +1639,9 @@ func (w *exportWriter) expr(n ir.Node) {
 	// (somewhat closely following the structure of exprfmt in fmt.go)
 	case ir.ONIL:
 		n := n.(*ir.NilExpr)
-		if !n.Type().HasNil() {
+		// If n is a typeparam, it will have already been checked
+		// for proper use by the types2 typechecker.
+		if !n.Type().IsTypeParam() && !n.Type().HasNil() {
 			base.Fatalf("unexpected type for nil: %v", n.Type())
 		}
 		w.op(ir.ONIL)
@@ -1469,7 +1650,11 @@ func (w *exportWriter) expr(n ir.Node) {
 
 	case ir.OLITERAL:
 		w.op(ir.OLITERAL)
-		w.pos(n.Pos())
+		if ir.HasUniquePos(n) {
+			w.pos(n.Pos())
+		} else {
+			w.pos(src.NoXPos)
+		}
 		w.value(n.Type(), n.Val())
 
 	case ir.ONAME:
@@ -1488,6 +1673,16 @@ func (w *exportWriter) expr(n ir.Node) {
 		// We don't need a type here, as the type will be provided at the
 		// declaration of n.
 		w.op(ir.ONAME)
+
+		// This handles the case where we haven't yet transformed a call
+		// to a builtin, so we must write out the builtin as a name in the
+		// builtin package.
+		isBuiltin := n.BuiltinOp != ir.OXXX
+		w.bool(isBuiltin)
+		if isBuiltin {
+			w.string(n.Sym().Name)
+			break
+		}
 		w.localName(n)
 
 	// case OPACK, ONONAME:
@@ -1585,12 +1780,11 @@ func (w *exportWriter) expr(n ir.Node) {
 	// case OSTRUCTKEY:
 	//	unreachable - handled in case OSTRUCTLIT by elemList
 
-	case ir.OXDOT, ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
+	case ir.OXDOT, ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OMETHVALUE, ir.OMETHEXPR:
 		n := n.(*ir.SelectorExpr)
 		if go117ExportTypes {
-			if n.Op() == ir.OXDOT {
-				base.Fatalf("shouldn't encounter XDOT  in new exporter")
-			}
+			// For go117ExportTypes, we usually see all ops except
+			// OXDOT, but we can see OXDOT for generic functions.
 			w.op(n.Op())
 		} else {
 			w.op(ir.OXDOT)
@@ -1600,11 +1794,16 @@ func (w *exportWriter) expr(n ir.Node) {
 		w.exoticSelector(n.Sel)
 		if go117ExportTypes {
 			w.exoticType(n.Type())
-			if n.Op() == ir.ODOT || n.Op() == ir.ODOTPTR || n.Op() == ir.ODOTINTER {
+			if n.Op() == ir.OXDOT {
+				// n.Selection for method references will be
+				// reconstructed during import.
+				w.bool(n.Selection != nil)
+			} else if n.Op() == ir.ODOT || n.Op() == ir.ODOTPTR || n.Op() == ir.ODOTINTER {
 				w.exoticField(n.Selection)
 			}
-			// n.Selection is not required for OMETHEXPR, ODOTMETH, and OCALLPART. It will
-			// be reconstructed during import.
+			// n.Selection is not required for OMETHEXPR, ODOTMETH, and OMETHVALUE. It will
+			// be reconstructed during import.  n.Selection is computed during
+			// transformDot() for OXDOT.
 		}
 
 	case ir.ODOTTYPE, ir.ODOTTYPE2:
@@ -1629,7 +1828,7 @@ func (w *exportWriter) expr(n ir.Node) {
 		w.expr(n.X)
 		w.expr(n.Index)
 		if go117ExportTypes {
-			w.typ(n.Type())
+			w.exoticType(n.Type())
 			if n.Op() == ir.OINDEXMAP {
 				w.bool(n.Assigned)
 			}
@@ -1677,7 +1876,7 @@ func (w *exportWriter) expr(n ir.Node) {
 			w.op(ir.OEND)
 		}
 
-	case ir.OCONV, ir.OCONVIFACE, ir.OCONVNOP, ir.OBYTES2STR, ir.ORUNES2STR, ir.OSTR2BYTES, ir.OSTR2RUNES, ir.ORUNESTR, ir.OSLICE2ARRPTR:
+	case ir.OCONV, ir.OCONVIFACE, ir.OCONVIDATA, ir.OCONVNOP, ir.OBYTES2STR, ir.ORUNES2STR, ir.OSTR2BYTES, ir.OSTR2RUNES, ir.ORUNESTR, ir.OSLICE2ARRPTR:
 		n := n.(*ir.ConvExpr)
 		if go117ExportTypes {
 			w.op(n.Op())
@@ -1732,7 +1931,6 @@ func (w *exportWriter) expr(n ir.Node) {
 		w.bool(n.IsDDD)
 		if go117ExportTypes {
 			w.exoticType(n.Type())
-			w.uint64(uint64(n.Use))
 		}
 
 	case ir.OMAKEMAP, ir.OMAKECHAN, ir.OMAKESLICE:
@@ -1759,8 +1957,16 @@ func (w *exportWriter) expr(n ir.Node) {
 			w.op(ir.OEND)
 		}
 
+	case ir.OLINKSYMOFFSET:
+		n := n.(*ir.LinksymOffsetExpr)
+		w.op(ir.OLINKSYMOFFSET)
+		w.pos(n.Pos())
+		w.string(n.Linksym.Name)
+		w.uint64(uint64(n.Offset_))
+		w.typ(n.Type())
+
 	// unary expressions
-	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.ORECV:
+	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.ORECV, ir.OIDATA:
 		n := n.(*ir.UnaryExpr)
 		w.op(n.Op())
 		w.pos(n.Pos())
@@ -1796,7 +2002,7 @@ func (w *exportWriter) expr(n ir.Node) {
 
 	// binary expressions
 	case ir.OADD, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OEQ, ir.OGE, ir.OGT, ir.OLE, ir.OLT,
-		ir.OLSH, ir.OMOD, ir.OMUL, ir.ONE, ir.OOR, ir.ORSH, ir.OSUB, ir.OXOR:
+		ir.OLSH, ir.OMOD, ir.OMUL, ir.ONE, ir.OOR, ir.ORSH, ir.OSUB, ir.OXOR, ir.OEFACE:
 		n := n.(*ir.BinaryExpr)
 		w.op(n.Op())
 		w.pos(n.Pos())
@@ -1829,6 +2035,26 @@ func (w *exportWriter) expr(n ir.Node) {
 		// if exporting, DCLCONST should just be removed as its usage
 		// has already been replaced with literals
 
+	case ir.OFUNCINST:
+		n := n.(*ir.InstExpr)
+		w.op(ir.OFUNCINST)
+		w.pos(n.Pos())
+		w.expr(n.X)
+		w.uint64(uint64(len(n.Targs)))
+		for _, targ := range n.Targs {
+			w.typ(targ.Type())
+		}
+		if go117ExportTypes {
+			w.typ(n.Type())
+		}
+
+	case ir.OSELRECV2:
+		n := n.(*ir.AssignListStmt)
+		w.op(ir.OSELRECV2)
+		w.pos(n.Pos())
+		w.exprList(n.Lhs)
+		w.exprList(n.Rhs)
+
 	default:
 		base.Fatalf("cannot export %v (%d) node\n"+
 			"\t==> please file an issue and assign to gri@", n.Op(), int(n.Op()))
@@ -1864,11 +2090,8 @@ func (w *exportWriter) fieldList(list ir.Nodes) {
 	for _, n := range list {
 		n := n.(*ir.StructKeyExpr)
 		w.pos(n.Pos())
-		w.selector(n.Field)
+		w.exoticField(n.Field)
 		w.expr(n.Value)
-		if go117ExportTypes {
-			w.uint64(uint64(n.Offset))
-		}
 	}
 }
 
@@ -1902,8 +2125,15 @@ func (w *exportWriter) localIdent(s *types.Sym) {
 		return
 	}
 
-	// TODO(mdempsky): Fix autotmp hack.
-	if i := strings.LastIndex(name, "."); i >= 0 && !strings.HasPrefix(name, ".autotmp_") {
+	// The name of autotmp variables isn't important; they just need to
+	// be unique. To stabilize the export data, simply write out "$" as
+	// a marker and let the importer generate its own unique name.
+	if strings.HasPrefix(name, ".autotmp_") {
+		w.string("$autotmp")
+		return
+	}
+
+	if i := strings.LastIndex(name, "."); i >= 0 && !strings.HasPrefix(name, ".dict") { // TODO: just use autotmp names for dictionaries?
 		base.Fatalf("unexpected dot in identifier: %v", name)
 	}
 
diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index a5ddbb5a74c..2e3fdbc1bc9 100644
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -8,10 +8,10 @@
 package typecheck
 
 import (
+	"bytes"
 	"encoding/binary"
 	"fmt"
 	"go/constant"
-	"io"
 	"math/big"
 	"os"
 	"strings"
@@ -19,8 +19,6 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
-	"cmd/internal/bio"
-	"cmd/internal/goobj"
 	"cmd/internal/obj"
 	"cmd/internal/src"
 )
@@ -94,7 +92,7 @@ func importReaderFor(sym *types.Sym, importers map[*types.Sym]iimporterAndOffset
 }
 
 type intReader struct {
-	*bio.Reader
+	*strings.Reader
 	pkg *types.Pkg
 }
 
@@ -116,33 +114,34 @@ func (r *intReader) uint64() uint64 {
 	return i
 }
 
-func ReadImports(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintType) {
-	ird := &intReader{in, pkg}
+func ReadImports(pkg *types.Pkg, data string) {
+	ird := &intReader{strings.NewReader(data), pkg}
 
 	version := ird.uint64()
-	if version != iexportVersion {
-		base.Errorf("import %q: unknown export format version %d", pkg.Path, version)
+	switch version {
+	case /* iexportVersionGenerics, */ iexportVersionPosCol, iexportVersionGo1_11:
+	default:
+		if version > iexportVersionGenerics {
+			base.Errorf("import %q: unstable export format version %d, just recompile", pkg.Path, version)
+		} else {
+			base.Errorf("import %q: unknown export format version %d", pkg.Path, version)
+		}
 		base.ErrorExit()
 	}
 
-	sLen := ird.uint64()
-	dLen := ird.uint64()
+	sLen := int64(ird.uint64())
+	dLen := int64(ird.uint64())
 
-	// Map string (and data) section into memory as a single large
-	// string. This reduces heap fragmentation and allows
-	// returning individual substrings very efficiently.
-	data, err := mapFile(in.File(), in.Offset(), int64(sLen+dLen))
-	if err != nil {
-		base.Errorf("import %q: mapping input: %v", pkg.Path, err)
-		base.ErrorExit()
-	}
-	stringData := data[:sLen]
-	declData := data[sLen:]
-
-	in.MustSeek(int64(sLen+dLen), os.SEEK_CUR)
+	// TODO(mdempsky): Replace os.SEEK_CUR with io.SeekCurrent after
+	// #44505 is fixed.
+	whence, _ := ird.Seek(0, os.SEEK_CUR)
+	stringData := data[whence : whence+sLen]
+	declData := data[whence+sLen : whence+sLen+dLen]
+	ird.Seek(sLen+dLen, os.SEEK_CUR)
 
 	p := &iimporter{
-		ipkg: pkg,
+		exportVersion: version,
+		ipkg:          pkg,
 
 		pkgCache:     map[uint64]*types.Pkg{},
 		posBaseCache: map[uint64]*src.PosBase{},
@@ -200,18 +199,11 @@ func ReadImports(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintT
 			}
 		}
 	}
-
-	// Fingerprint.
-	_, err = io.ReadFull(in, fingerprint[:])
-	if err != nil {
-		base.Errorf("import %s: error reading fingerprint", pkg.Path)
-		base.ErrorExit()
-	}
-	return fingerprint
 }
 
 type iimporter struct {
-	ipkg *types.Pkg
+	exportVersion uint64
+	ipkg          *types.Pkg
 
 	pkgCache     map[uint64]*types.Pkg
 	posBaseCache map[uint64]*src.PosBase
@@ -273,6 +265,7 @@ type importReader struct {
 	// Slice of all dcls for function, including any interior closures
 	allDcls        []*ir.Name
 	allClosureVars []*ir.Name
+	autotmpgen     int
 }
 
 func (p *iimporter) newReader(off uint64, pkg *types.Pkg) *importReader {
@@ -302,37 +295,53 @@ func (r *importReader) doDecl(sym *types.Sym) *ir.Name {
 	case 'A':
 		typ := r.typ()
 
-		return importalias(r.p.ipkg, pos, sym, typ)
+		return importalias(pos, sym, typ)
 
 	case 'C':
 		typ := r.typ()
 		val := r.value(typ)
 
-		n := importconst(r.p.ipkg, pos, sym, typ, val)
+		n := importconst(pos, sym, typ, val)
 		r.constExt(n)
 		return n
 
-	case 'F':
-		typ := r.signature(nil)
+	case 'F', 'G':
+		var tparams []*types.Field
+		if tag == 'G' {
+			tparams = r.tparamList()
+		}
+		typ := r.signature(nil, tparams)
 
-		n := importfunc(r.p.ipkg, pos, sym, typ)
+		n := importfunc(pos, sym, typ)
 		r.funcExt(n)
 		return n
 
-	case 'T':
+	case 'T', 'U':
+		var rparams []*types.Type
+		if tag == 'U' {
+			rparams = r.typeList()
+		}
+
 		// Types can be recursive. We need to setup a stub
 		// declaration before recursing.
-		n := importtype(r.p.ipkg, pos, sym)
+		n := importtype(pos, sym)
 		t := n.Type()
+		if tag == 'U' {
+			t.SetRParams(rparams)
+		}
 
 		// We also need to defer width calculations until
 		// after the underlying type has been assigned.
 		types.DeferCheckSize()
+		deferDoInst()
 		underlying := r.typ()
 		t.SetUnderlying(underlying)
-		types.ResumeCheckSize()
 
 		if underlying.IsInterface() {
+			// Finish up all type instantiations and CheckSize calls
+			// now that a top-level type is fully constructed.
+			resumeDoInst()
+			types.ResumeCheckSize()
 			r.typeExt(t)
 			return n
 		}
@@ -342,7 +351,7 @@ func (r *importReader) doDecl(sym *types.Sym) *ir.Name {
 			mpos := r.pos()
 			msym := r.selector()
 			recv := r.param()
-			mtyp := r.signature(recv)
+			mtyp := r.signature(recv, nil)
 
 			// MethodSym already marked m.Sym as a function.
 			m := ir.NewNameAt(mpos, ir.MethodSym(recv.Type, msym))
@@ -358,16 +367,43 @@ func (r *importReader) doDecl(sym *types.Sym) *ir.Name {
 		}
 		t.Methods().Set(ms)
 
+		// Finish up all instantiations and CheckSize calls now
+		// that a top-level type is fully constructed.
+		resumeDoInst()
+		types.ResumeCheckSize()
+
 		r.typeExt(t)
 		for _, m := range ms {
 			r.methExt(m)
 		}
 		return n
 
+	case 'P':
+		if r.p.exportVersion < iexportVersionGenerics {
+			base.Fatalf("unexpected type param type")
+		}
+		if sym.Def != nil {
+			// Make sure we use the same type param type for the same
+			// name, whether it is created during types1-import or
+			// this types2-to-types1 translation.
+			return sym.Def.(*ir.Name)
+		}
+		// The typeparam index is set at the point where the containing type
+		// param list is imported.
+		t := types.NewTypeParam(sym, 0)
+		// Nname needed to save the pos.
+		nname := ir.NewDeclNameAt(pos, ir.OTYPE, sym)
+		sym.Def = nname
+		nname.SetType(t)
+		t.SetNod(nname)
+
+		t.SetBound(r.typ())
+		return nname
+
 	case 'V':
 		typ := r.typ()
 
-		n := importvar(r.p.ipkg, pos, sym, typ)
+		n := importvar(pos, sym, typ)
 		r.varExt(n)
 		return n
 
@@ -377,27 +413,47 @@ func (r *importReader) doDecl(sym *types.Sym) *ir.Name {
 	}
 }
 
-func (p *importReader) value(typ *types.Type) constant.Value {
-	switch constTypeOf(typ) {
+func (r *importReader) value(typ *types.Type) constant.Value {
+	var kind constant.Kind
+	var valType *types.Type
+
+	if typ.IsTypeParam() {
+		// If a constant had a typeparam type, then we wrote out its
+		// actual constant kind as well.
+		kind = constant.Kind(r.int64())
+		switch kind {
+		case constant.Int:
+			valType = types.Types[types.TINT64]
+		case constant.Float:
+			valType = types.Types[types.TFLOAT64]
+		case constant.Complex:
+			valType = types.Types[types.TCOMPLEX128]
+		}
+	} else {
+		kind = constTypeOf(typ)
+		valType = typ
+	}
+
+	switch kind {
 	case constant.Bool:
-		return constant.MakeBool(p.bool())
+		return constant.MakeBool(r.bool())
 	case constant.String:
-		return constant.MakeString(p.string())
+		return constant.MakeString(r.string())
 	case constant.Int:
 		var i big.Int
-		p.mpint(&i, typ)
+		r.mpint(&i, valType)
 		return constant.Make(&i)
 	case constant.Float:
-		return p.float(typ)
+		return r.float(valType)
 	case constant.Complex:
-		return makeComplex(p.float(typ), p.float(typ))
+		return makeComplex(r.float(valType), r.float(valType))
 	}
 
 	base.Fatalf("unexpected value type: %v", typ)
 	panic("unreachable")
 }
 
-func (p *importReader) mpint(x *big.Int, typ *types.Type) {
+func (r *importReader) mpint(x *big.Int, typ *types.Type) {
 	signed, maxBytes := intSize(typ)
 
 	maxSmall := 256 - maxBytes
@@ -408,7 +464,7 @@ func (p *importReader) mpint(x *big.Int, typ *types.Type) {
 		maxSmall = 256
 	}
 
-	n, _ := p.ReadByte()
+	n, _ := r.ReadByte()
 	if uint(n) < maxSmall {
 		v := int64(n)
 		if signed {
@@ -429,30 +485,30 @@ func (p *importReader) mpint(x *big.Int, typ *types.Type) {
 		base.Fatalf("weird decoding: %v, %v => %v", n, signed, v)
 	}
 	b := make([]byte, v)
-	p.Read(b)
+	r.Read(b)
 	x.SetBytes(b)
 	if signed && n&1 != 0 {
 		x.Neg(x)
 	}
 }
 
-func (p *importReader) float(typ *types.Type) constant.Value {
+func (r *importReader) float(typ *types.Type) constant.Value {
 	var mant big.Int
-	p.mpint(&mant, typ)
+	r.mpint(&mant, typ)
 	var f big.Float
 	f.SetInt(&mant)
 	if f.Sign() != 0 {
-		f.SetMantExp(&f, int(p.int64()))
+		f.SetMantExp(&f, int(r.int64()))
 	}
 	return constant.Make(&f)
 }
 
-func (p *importReader) mprat(orig constant.Value) constant.Value {
-	if !p.bool() {
+func (r *importReader) mprat(orig constant.Value) constant.Value {
+	if !r.bool() {
 		return orig
 	}
 	var rat big.Rat
-	rat.SetString(p.string())
+	rat.SetString(r.string())
 	return constant.Make(&rat)
 }
 
@@ -462,8 +518,15 @@ func (r *importReader) ident(selector bool) *types.Sym {
 		return nil
 	}
 	pkg := r.currPkg
-	if selector && types.IsExported(name) {
-		pkg = types.LocalPkg
+	if selector {
+		if types.IsExported(name) {
+			pkg = types.LocalPkg
+		}
+	} else {
+		if name == "$autotmp" {
+			name = autotmpname(r.autotmpgen)
+			r.autotmpgen++
+		}
 	}
 	return pkg.Lookup(name)
 }
@@ -503,7 +566,14 @@ func (r *importReader) pos() src.XPos {
 }
 
 func (r *importReader) typ() *types.Type {
-	return r.p.typAt(r.uint64())
+	// If this is a top-level type call, defer type instantiations until the
+	// type is fully constructed.
+	types.DeferCheckSize()
+	deferDoInst()
+	t := r.p.typAt(r.uint64())
+	resumeDoInst()
+	types.ResumeCheckSize()
+	return t
 }
 
 func (r *importReader) exoticType() *types.Type {
@@ -641,7 +711,13 @@ func (p *iimporter) typAt(off uint64) *types.Type {
 		// are pushed to compile queue, then draining from the queue for compiling.
 		// During this process, the size calculation is disabled, so it is not safe for
 		// calculating size during SSA generation anymore. See issue #44732.
-		types.CheckSize(t)
+		//
+		// No need to calc sizes for re-instantiated generic types, and
+		// they are not necessarily resolved until the top-level type is
+		// defined (because of recursive types).
+		if t.OrigSym == nil || !t.HasTParam() {
+			types.CheckSize(t)
+		}
 		p.typCache[off] = t
 	}
 	return t
@@ -680,7 +756,7 @@ func (r *importReader) typ1() *types.Type {
 
 	case signatureType:
 		r.setPkg()
-		return r.signature(nil)
+		return r.signature(nil, nil)
 
 	case structType:
 		r.setPkg()
@@ -718,16 +794,64 @@ func (r *importReader) typ1() *types.Type {
 		for i := range methods {
 			pos := r.pos()
 			sym := r.selector()
-			typ := r.signature(fakeRecvField())
+			typ := r.signature(fakeRecvField(), nil)
 
 			methods[i] = types.NewField(pos, sym, typ)
 		}
 
+		if len(embeddeds)+len(methods) == 0 {
+			return types.Types[types.TINTER]
+		}
+
 		t := types.NewInterface(r.currPkg, append(embeddeds, methods...))
 
 		// Ensure we expand the interface in the frontend (#25055).
 		types.CheckSize(t)
 		return t
+
+	case typeParamType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			base.Fatalf("unexpected type param type")
+		}
+		// Similar to code for defined types, since we "declared"
+		// typeparams to deal with recursion (typeparam is used within its
+		// own type bound).
+		ident := r.qualifiedIdent()
+		if ident.Sym().Def != nil {
+			return ident.Sym().Def.(*ir.Name).Type()
+		}
+		n := expandDecl(ident)
+		if n.Op() != ir.OTYPE {
+			base.Fatalf("expected OTYPE, got %v: %v, %v", n.Op(), n.Sym(), n)
+		}
+		return n.Type()
+
+	case instType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			base.Fatalf("unexpected instantiation type")
+		}
+		pos := r.pos()
+		len := r.uint64()
+		targs := make([]*types.Type, len)
+		for i := range targs {
+			targs[i] = r.typ()
+		}
+		baseType := r.typ()
+		t := Instantiate(pos, baseType, targs)
+		return t
+
+	case unionType:
+		if r.p.exportVersion < iexportVersionGenerics {
+			base.Fatalf("unexpected instantiation type")
+		}
+		nt := int(r.uint64())
+		terms := make([]*types.Type, nt)
+		tildes := make([]bool, nt)
+		for i := range terms {
+			tildes[i] = r.bool()
+			terms[i] = r.typ()
+		}
+		return types.NewUnion(terms, tildes)
 	}
 }
 
@@ -735,13 +859,42 @@ func (r *importReader) kind() itag {
 	return itag(r.uint64())
 }
 
-func (r *importReader) signature(recv *types.Field) *types.Type {
+func (r *importReader) signature(recv *types.Field, tparams []*types.Field) *types.Type {
 	params := r.paramList()
 	results := r.paramList()
 	if n := len(params); n > 0 {
 		params[n-1].SetIsDDD(r.bool())
 	}
-	return types.NewSignature(r.currPkg, recv, nil, params, results)
+	return types.NewSignature(r.currPkg, recv, tparams, params, results)
+}
+
+func (r *importReader) typeList() []*types.Type {
+	n := r.uint64()
+	if n == 0 {
+		return nil
+	}
+	ts := make([]*types.Type, n)
+	for i := range ts {
+		ts[i] = r.typ()
+		if ts[i].IsTypeParam() {
+			ts[i].SetIndex(i)
+		}
+	}
+	return ts
+}
+
+func (r *importReader) tparamList() []*types.Field {
+	n := r.uint64()
+	if n == 0 {
+		return nil
+	}
+	fs := make([]*types.Field, n)
+	for i := range fs {
+		typ := r.typ()
+		typ.SetIndex(i)
+		fs[i] = types.NewField(typ.Pos(), typ.Sym(), typ)
+	}
+	return fs
 }
 
 func (r *importReader) paramList() []*types.Field {
@@ -809,7 +962,9 @@ func (r *importReader) funcExt(n *ir.Name) {
 
 	n.Func.ABI = obj.ABI(r.uint64())
 
-	n.SetPragma(ir.PragmaFlag(r.uint64()))
+	// Make sure //go:noinline pragma is imported (so stenciled functions have
+	// same noinline status as the corresponding generic function.)
+	n.Func.Pragma = ir.PragmaFlag(r.uint64())
 
 	// Escape analysis.
 	for _, fs := range &types.RecvsParams {
@@ -821,7 +976,8 @@ func (r *importReader) funcExt(n *ir.Name) {
 	// Inline body.
 	if u := r.uint64(); u > 0 {
 		n.Func.Inl = &ir.Inline{
-			Cost: int32(u - 1),
+			Cost:            int32(u - 1),
+			CanDelayResults: r.bool(),
 		}
 		n.Func.Endlineno = r.pos()
 	}
@@ -852,7 +1008,13 @@ func (r *importReader) symIdx(s *types.Sym) {
 
 func (r *importReader) typeExt(t *types.Type) {
 	t.SetNotInHeap(r.bool())
-	i, pi := r.int64(), r.int64()
+	SetBaseTypeIndex(t, r.int64(), r.int64())
+}
+
+func SetBaseTypeIndex(t *types.Type, i, pi int64) {
+	if t.Obj() == nil {
+		base.Fatalf("SetBaseTypeIndex on non-defined type %v", t)
+	}
 	if i != -1 && pi != -1 {
 		typeSymIdx[t] = [2]int64{i, pi}
 	}
@@ -860,6 +1022,7 @@ func (r *importReader) typeExt(t *types.Type) {
 
 // Map imported type T to the index of type descriptor symbols of T and *T,
 // so we can use index to reference the symbol.
+// TODO(mdempsky): Store this information directly in the Type's Name.
 var typeSymIdx = make(map[*types.Type][2]int64)
 
 func BaseTypeIndex(t *types.Type) int64 {
@@ -936,6 +1099,10 @@ func (r *importReader) funcBody(fn *ir.Func) {
 	fn.Inl.Body = body
 
 	r.curfn = outerfn
+	if base.Flag.W >= 3 {
+		fmt.Printf("Imported for %v", fn)
+		ir.DumpList("", fn.Inl.Body)
+	}
 }
 
 func (r *importReader) readNames(fn *ir.Func) []*ir.Name {
@@ -1032,7 +1199,13 @@ func (r *importReader) caseList(switchExpr ir.Node) []*ir.CaseClause {
 func (r *importReader) commList() []*ir.CommClause {
 	cases := make([]*ir.CommClause, r.uint64())
 	for i := range cases {
-		cases[i] = ir.NewCommStmt(r.pos(), r.node(), r.stmtList())
+		pos := r.pos()
+		defaultCase := r.bool()
+		var comm ir.Node
+		if !defaultCase {
+			comm = r.node()
+		}
+		cases[i] = ir.NewCommStmt(pos, comm, r.stmtList())
 	}
 	return cases
 }
@@ -1095,6 +1268,10 @@ func (r *importReader) node() ir.Node {
 		return n
 
 	case ir.ONAME:
+		isBuiltin := r.bool()
+		if isBuiltin {
+			return types.BuiltinPkg.Lookup(r.string()).Def.(*ir.Name)
+		}
 		return r.localName()
 
 	// case OPACK, ONONAME:
@@ -1117,28 +1294,18 @@ func (r *importReader) node() ir.Node {
 	case ir.OCLOSURE:
 		//println("Importing CLOSURE")
 		pos := r.pos()
-		typ := r.signature(nil)
+		typ := r.signature(nil, nil)
 
 		// All the remaining code below is similar to (*noder).funcLit(), but
 		// with Dcls and ClosureVars lists already set up
-		fn := ir.NewFunc(pos)
-		fn.SetIsHiddenClosure(true)
-		fn.Nname = ir.NewNameAt(pos, ir.BlankNode.Sym())
-		fn.Nname.Func = fn
-		fn.Nname.Ntype = ir.TypeNode(typ)
-		fn.Nname.Defn = fn
+		fn := ir.NewClosureFunc(pos, true)
 		fn.Nname.SetType(typ)
 
 		cvars := make([]*ir.Name, r.int64())
 		for i := range cvars {
 			cvars[i] = ir.CaptureName(r.pos(), fn, r.localName().Canonical())
-			if go117ExportTypes {
-				if cvars[i].Type() != nil || cvars[i].Defn == nil {
-					base.Fatalf("bad import of closure variable")
-				}
-				// Closure variable should have Defn set, which is its captured
-				// variable, and it gets the same type as the captured variable.
-				cvars[i].SetType(cvars[i].Defn.Type())
+			if go117ExportTypes && cvars[i].Defn == nil {
+				base.Fatalf("bad import of closure variable")
 			}
 		}
 		fn.ClosureVars = cvars
@@ -1159,12 +1326,10 @@ func (r *importReader) node() ir.Node {
 
 		ir.FinishCaptureNames(pos, r.curfn, fn)
 
-		clo := ir.NewClosureExpr(pos, fn)
-		fn.OClosure = clo
+		clo := fn.OClosure
 		if go117ExportTypes {
 			clo.SetType(typ)
 		}
-
 		return clo
 
 	case ir.OSTRUCTLIT:
@@ -1202,35 +1367,54 @@ func (r *importReader) node() ir.Node {
 	// case OSTRUCTKEY:
 	//	unreachable - handled in case OSTRUCTLIT by elemList
 
-	case ir.OXDOT:
-		// see parser.new_dotname
-		if go117ExportTypes {
-			base.Fatalf("shouldn't encounter XDOT in new importer")
-		}
-		return ir.NewSelectorExpr(r.pos(), ir.OXDOT, r.expr(), r.exoticSelector())
-
-	case ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
-		if !go117ExportTypes {
-			// unreachable - mapped to case OXDOT by exporter
+	case ir.OXDOT, ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OMETHVALUE, ir.OMETHEXPR:
+		// For !go117ExportTypes,  we should only see OXDOT.
+		// For go117ExportTypes, we usually see all the other ops, but can see
+		// OXDOT for generic functions.
+		if op != ir.OXDOT && !go117ExportTypes {
 			goto error
 		}
 		pos := r.pos()
 		expr := r.expr()
 		sel := r.exoticSelector()
 		n := ir.NewSelectorExpr(pos, op, expr, sel)
-		n.SetType(r.exoticType())
-		switch op {
-		case ir.ODOT, ir.ODOTPTR, ir.ODOTINTER:
-			n.Selection = r.exoticField()
-		case ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
-			// These require a Lookup to link to the correct declaration.
-			rcvrType := expr.Type()
-			typ := n.Type()
-			n.Selection = Lookdot(n, rcvrType, 1)
-			if op == ir.OCALLPART || op == ir.OMETHEXPR {
-				// Lookdot clobbers the opcode and type, undo that.
-				n.SetOp(op)
-				n.SetType(typ)
+		if go117ExportTypes {
+			n.SetType(r.exoticType())
+			switch op {
+			case ir.OXDOT:
+				hasSelection := r.bool()
+				// We reconstruct n.Selection for method calls on
+				// generic types and method calls due to type param
+				// bounds.  Otherwise, n.Selection is nil.
+				if hasSelection {
+					n1 := ir.NewSelectorExpr(pos, op, expr, sel)
+					AddImplicitDots(n1)
+					var m *types.Field
+					if n1.X.Type().IsTypeParam() {
+						genType := n1.X.Type().Bound()
+						m = Lookdot1(n1, sel, genType, genType.AllMethods(), 1)
+					} else {
+						genType := types.ReceiverBaseType(n1.X.Type())
+						if genType.IsInstantiatedGeneric() {
+							genType = genType.OrigSym.Def.Type()
+						}
+						m = Lookdot1(n1, sel, genType, genType.Methods(), 1)
+					}
+					assert(m != nil)
+					n.Selection = m
+				}
+			case ir.ODOT, ir.ODOTPTR, ir.ODOTINTER:
+				n.Selection = r.exoticField()
+			case ir.ODOTMETH, ir.OMETHVALUE, ir.OMETHEXPR:
+				// These require a Lookup to link to the correct declaration.
+				rcvrType := expr.Type()
+				typ := n.Type()
+				n.Selection = Lookdot(n, rcvrType, 1)
+				if op == ir.OMETHVALUE || op == ir.OMETHEXPR {
+					// Lookdot clobbers the opcode and type, undo that.
+					n.SetOp(op)
+					n.SetType(typ)
+				}
 			}
 		}
 		return n
@@ -1247,7 +1431,7 @@ func (r *importReader) node() ir.Node {
 		n := ir.NewIndexExpr(r.pos(), r.expr(), r.expr())
 		if go117ExportTypes {
 			n.SetOp(op)
-			n.SetType(r.typ())
+			n.SetType(r.exoticType())
 			if op == ir.OINDEXMAP {
 				n.Assigned = r.bool()
 			}
@@ -1267,7 +1451,7 @@ func (r *importReader) node() ir.Node {
 		}
 		return n
 
-	case ir.OCONV, ir.OCONVIFACE, ir.OCONVNOP, ir.OBYTES2STR, ir.ORUNES2STR, ir.OSTR2BYTES, ir.OSTR2RUNES, ir.ORUNESTR, ir.OSLICE2ARRPTR:
+	case ir.OCONV, ir.OCONVIFACE, ir.OCONVIDATA, ir.OCONVNOP, ir.OBYTES2STR, ir.ORUNES2STR, ir.OSTR2BYTES, ir.OSTR2RUNES, ir.ORUNESTR, ir.OSLICE2ARRPTR:
 		if !go117ExportTypes && op != ir.OCONV {
 			// 	unreachable - mapped to OCONV case by exporter
 			goto error
@@ -1318,7 +1502,6 @@ func (r *importReader) node() ir.Node {
 		n.IsDDD = r.bool()
 		if go117ExportTypes {
 			n.SetType(r.exoticType())
-			n.Use = ir.CallUse(r.uint64())
 		}
 		return n
 
@@ -1343,8 +1526,15 @@ func (r *importReader) node() ir.Node {
 		n.Args.Append(r.exprList()...)
 		return n
 
+	case ir.OLINKSYMOFFSET:
+		pos := r.pos()
+		name := r.string()
+		off := r.uint64()
+		typ := r.typ()
+		return ir.NewLinksymOffsetExpr(pos, Lookup(name).Linksym(), int64(off), typ)
+
 	// unary expressions
-	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.ORECV:
+	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.ORECV, ir.OIDATA:
 		n := ir.NewUnaryExpr(r.pos(), op, r.expr())
 		if go117ExportTypes {
 			n.SetType(r.typ())
@@ -1368,7 +1558,7 @@ func (r *importReader) node() ir.Node {
 
 	// binary expressions
 	case ir.OADD, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OEQ, ir.OGE, ir.OGT, ir.OLE, ir.OLT,
-		ir.OLSH, ir.OMOD, ir.OMUL, ir.ONE, ir.OOR, ir.ORSH, ir.OSUB, ir.OXOR:
+		ir.OLSH, ir.OMOD, ir.OMUL, ir.ONE, ir.OOR, ir.ORSH, ir.OSUB, ir.OXOR, ir.OEFACE:
 		n := ir.NewBinaryExpr(r.pos(), op, r.expr(), r.expr())
 		if go117ExportTypes {
 			n.SetType(r.typ())
@@ -1496,6 +1686,26 @@ func (r *importReader) node() ir.Node {
 	case ir.OEND:
 		return nil
 
+	case ir.OFUNCINST:
+		pos := r.pos()
+		x := r.expr()
+		ntargs := r.uint64()
+		var targs []ir.Node
+		if ntargs > 0 {
+			targs = make([]ir.Node, ntargs)
+			for i := range targs {
+				targs[i] = ir.TypeNode(r.typ())
+			}
+		}
+		n := ir.NewInstExpr(pos, ir.OFUNCINST, x, targs)
+		if go117ExportTypes {
+			n.SetType(r.typ())
+		}
+		return n
+
+	case ir.OSELRECV2:
+		return ir.NewAssignListStmt(r.pos(), ir.OSELRECV2, r.exprList(), r.exprList())
+
 	default:
 		base.Fatalf("cannot import %v (%d) node\n"+
 			"\t==> please file an issue and assign to gri@", op, int(op))
@@ -1517,11 +1727,7 @@ func (r *importReader) op() ir.Op {
 func (r *importReader) fieldList() []ir.Node {
 	list := make([]ir.Node, r.uint64())
 	for i := range list {
-		x := ir.NewStructKeyExpr(r.pos(), r.selector(), r.expr())
-		if go117ExportTypes {
-			x.Offset = int64(r.uint64())
-		}
-		list[i] = x
+		list[i] = ir.NewStructKeyExpr(r.pos(), r.exoticField(), r.expr())
 	}
 	return list
 }
@@ -1540,7 +1746,150 @@ func (r *importReader) exprsOrNil() (a, b ir.Node) {
 func builtinCall(pos src.XPos, op ir.Op) *ir.CallExpr {
 	if go117ExportTypes {
 		// These should all be encoded as direct ops, not OCALL.
-		base.Fatalf("builtinCall should not be invoked when types are included in inport/export")
+		base.Fatalf("builtinCall should not be invoked when types are included in import/export")
 	}
 	return ir.NewCallExpr(pos, ir.OCALL, ir.NewIdent(base.Pos, types.BuiltinPkg.Lookup(ir.OpNames[op])), nil)
 }
+
+// InstTypeName creates a name for an instantiated type, based on the name of the
+// generic type and the type args.
+func InstTypeName(name string, targs []*types.Type) string {
+	b := bytes.NewBufferString(name)
+	b.WriteByte('[')
+	for i, targ := range targs {
+		if i > 0 {
+			b.WriteByte(',')
+		}
+		// WriteString() does not include the package name for the local
+		// package, but we want it to make sure type arguments (including
+		// type params) are uniquely specified.
+		if targ.Sym() != nil && targ.Sym().Pkg == types.LocalPkg {
+			b.WriteString(targ.Sym().Pkg.Name)
+			b.WriteByte('.')
+		}
+		// types1 uses "interface {" and types2 uses "interface{" - convert
+		// to consistent types2 format.
+		tstring := targ.String()
+		tstring = strings.Replace(tstring, "interface {", "interface{", -1)
+		b.WriteString(tstring)
+	}
+	b.WriteByte(']')
+	return b.String()
+}
+
+// NewIncompleteNamedType returns a TFORW type t with name specified by sym, such
+// that t.nod and sym.Def are set correctly.
+func NewIncompleteNamedType(pos src.XPos, sym *types.Sym) *types.Type {
+	name := ir.NewDeclNameAt(pos, ir.OTYPE, sym)
+	forw := types.NewNamed(name)
+	name.SetType(forw)
+	sym.Def = name
+	return forw
+}
+
+// Instantiate creates a new named type which is the instantiation of the base
+// named generic type, with the specified type args.
+func Instantiate(pos src.XPos, baseType *types.Type, targs []*types.Type) *types.Type {
+	baseSym := baseType.Sym()
+	if strings.Index(baseSym.Name, "[") >= 0 {
+		base.Fatalf("arg to Instantiate is not a base generic type")
+	}
+	name := InstTypeName(baseSym.Name, targs)
+	instSym := baseSym.Pkg.Lookup(name)
+	if instSym.Def != nil {
+		// May match existing type from previous import or
+		// types2-to-types1 conversion, or from in-progress instantiation
+		// in the current type import stack.
+		return instSym.Def.Type()
+	}
+
+	t := NewIncompleteNamedType(baseType.Pos(), instSym)
+	t.SetRParams(targs)
+	t.OrigSym = baseSym
+
+	// baseType may still be TFORW or its methods may not be fully filled in
+	// (since we are in the middle of importing it). So, delay call to
+	// substInstType until we get back up to the top of the current top-most
+	// type import.
+	deferredInstStack = append(deferredInstStack, t)
+
+	return t
+}
+
+var deferredInstStack []*types.Type
+var deferInst int
+
+// deferDoInst defers substitution on instantiated types until we are at the
+// top-most defined type, so the base types are fully defined.
+func deferDoInst() {
+	deferInst++
+}
+
+func resumeDoInst() {
+	if deferInst == 1 {
+		for len(deferredInstStack) > 0 {
+			t := deferredInstStack[0]
+			deferredInstStack = deferredInstStack[1:]
+			substInstType(t, t.OrigSym.Def.(*ir.Name).Type(), t.RParams())
+		}
+	}
+	deferInst--
+}
+
+// doInst creates a new instantiation type (which will be added to
+// deferredInstStack for completion later) for an incomplete type encountered
+// during a type substitution for an instantiation. This is needed for
+// instantiations of mutually recursive types.
+func doInst(t *types.Type) *types.Type {
+	return Instantiate(t.Pos(), t.OrigSym.Def.(*ir.Name).Type(), t.RParams())
+}
+
+// substInstType completes the instantiation of a generic type by doing a
+// substitution on the underlying type itself and any methods. t is the
+// instantiation being created, baseType is the base generic type, and targs are
+// the type arguments that baseType is being instantiated with.
+func substInstType(t *types.Type, baseType *types.Type, targs []*types.Type) {
+	subst := Tsubster{
+		Tparams:       baseType.RParams(),
+		Targs:         targs,
+		SubstForwFunc: doInst,
+	}
+	t.SetUnderlying(subst.Typ(baseType.Underlying()))
+
+	newfields := make([]*types.Field, baseType.Methods().Len())
+	for i, f := range baseType.Methods().Slice() {
+		if !f.IsMethod() || types.IsInterfaceMethod(f.Type) {
+			// Do a normal substitution if this is a non-method (which
+			// means this must be an interface used as a constraint) or
+			// an interface method.
+			t2 := subst.Typ(f.Type)
+			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
+			continue
+		}
+		recvType := f.Type.Recv().Type
+		if recvType.IsPtr() {
+			recvType = recvType.Elem()
+		}
+		// Substitute in the method using the type params used in the
+		// method (not the type params in the definition of the generic type).
+		msubst := Tsubster{
+			Tparams:       recvType.RParams(),
+			Targs:         targs,
+			SubstForwFunc: doInst,
+		}
+		t2 := msubst.Typ(f.Type)
+		oldsym := f.Nname.Sym()
+		newsym := MakeInstName(oldsym, targs, true)
+		var nname *ir.Name
+		if newsym.Def != nil {
+			nname = newsym.Def.(*ir.Name)
+		} else {
+			nname = ir.NewNameAt(f.Pos, newsym)
+			nname.SetType(t2)
+			newsym.Def = nname
+		}
+		newfields[i] = types.NewField(f.Pos, f.Sym, t2)
+		newfields[i].Nname = nname
+	}
+	t.Methods().Set(newfields)
+}
diff --git a/src/cmd/compile/internal/typecheck/stmt.go b/src/cmd/compile/internal/typecheck/stmt.go
index 175216f279c..c322d490e5b 100644
--- a/src/cmd/compile/internal/typecheck/stmt.go
+++ b/src/cmd/compile/internal/typecheck/stmt.go
@@ -172,6 +172,10 @@ assignOK:
 			r := r.(*ir.TypeAssertExpr)
 			stmt.SetOp(ir.OAS2DOTTYPE)
 			r.SetOp(ir.ODOTTYPE2)
+		case ir.ODYNAMICDOTTYPE:
+			r := r.(*ir.DynamicTypeAssertExpr)
+			stmt.SetOp(ir.OAS2DOTTYPE)
+			r.SetOp(ir.ODYNAMICDOTTYPE2)
 		default:
 			break assignOK
 		}
@@ -201,11 +205,22 @@ assignOK:
 		stmt := stmt.(*ir.AssignListStmt)
 		stmt.SetOp(ir.OAS2FUNC)
 		r := rhs[0].(*ir.CallExpr)
-		r.Use = ir.CallUseList
 		rtyp := r.Type()
 
+		mismatched := false
+		failed := false
 		for i := range lhs {
-			assignType(i, rtyp.Field(i).Type)
+			result := rtyp.Field(i).Type
+			assignType(i, result)
+
+			if lhs[i].Type() == nil || result == nil {
+				failed = true
+			} else if lhs[i] != ir.BlankNode && !types.Identical(lhs[i].Type(), result) {
+				mismatched = true
+			}
+		}
+		if mismatched && !failed {
+			RewriteMultiValueCall(stmt, r)
 		}
 		return
 	}
@@ -225,6 +240,15 @@ func plural(n int) string {
 	return "s"
 }
 
+// tcCheckNil typechecks an OCHECKNIL node.
+func tcCheckNil(n *ir.UnaryExpr) ir.Node {
+	n.X = Expr(n.X)
+	if !n.X.Type().IsPtrShaped() {
+		base.FatalfAt(n.Pos(), "%L is not pointer shaped", n.X)
+	}
+	return n
+}
+
 // tcFor typechecks an OFOR node.
 func tcFor(n *ir.ForStmt) ir.Node {
 	Stmts(n.Init())
@@ -641,29 +665,18 @@ func tcSwitchType(n *ir.SwitchStmt) {
 }
 
 type typeSet struct {
-	m map[string][]typeSetEntry
-}
-
-type typeSetEntry struct {
-	pos src.XPos
-	typ *types.Type
+	m map[string]src.XPos
 }
 
 func (s *typeSet) add(pos src.XPos, typ *types.Type) {
 	if s.m == nil {
-		s.m = make(map[string][]typeSetEntry)
+		s.m = make(map[string]src.XPos)
 	}
 
-	// LongString does not uniquely identify types, so we need to
-	// disambiguate collisions with types.Identical.
-	// TODO(mdempsky): Add a method that *is* unique.
-	ls := typ.LongString()
-	prevs := s.m[ls]
-	for _, prev := range prevs {
-		if types.Identical(typ, prev.typ) {
-			base.ErrorfAt(pos, "duplicate case %v in type switch\n\tprevious case at %s", typ, base.FmtPos(prev.pos))
-			return
-		}
+	ls := typ.LinkString()
+	if prev, ok := s.m[ls]; ok {
+		base.ErrorfAt(pos, "duplicate case %v in type switch\n\tprevious case at %s", typ, base.FmtPos(prev))
+		return
 	}
-	s.m[ls] = append(prevs, typeSetEntry{pos, typ})
+	s.m[ls] = pos
 }
diff --git a/src/cmd/compile/internal/typecheck/subr.go b/src/cmd/compile/internal/typecheck/subr.go
index 9ee7a94b1f2..c7a3718b31c 100644
--- a/src/cmd/compile/internal/typecheck/subr.go
+++ b/src/cmd/compile/internal/typecheck/subr.go
@@ -5,6 +5,7 @@
 package typecheck
 
 import (
+	"bytes"
 	"fmt"
 	"sort"
 	"strconv"
@@ -352,9 +353,10 @@ func Assignop(src, dst *types.Type) (ir.Op, string) {
 		return ir.OCONVNOP, ""
 	}
 
-	// 2. src and dst have identical underlying types
-	// and either src or dst is not a named type or
-	// both are empty interface types.
+	// 2. src and dst have identical underlying types and
+	//   a. either src or dst is not a named type, or
+	//   b. both are empty interface types, or
+	//   c. at least one is a gcshape type.
 	// For assignable but different non-empty interface types,
 	// we want to recompute the itab. Recomputing the itab ensures
 	// that itabs are unique (thus an interface with a compile-time
@@ -371,21 +373,24 @@ func Assignop(src, dst *types.Type) (ir.Op, string) {
 			// which need to have their itab updated.
 			return ir.OCONVNOP, ""
 		}
+		if src.IsShape() || dst.IsShape() {
+			// Conversion between a shape type and one of the types
+			// it represents also needs no conversion.
+			return ir.OCONVNOP, ""
+		}
 	}
 
 	// 3. dst is an interface type and src implements dst.
 	if dst.IsInterface() && src.Kind() != types.TNIL {
 		var missing, have *types.Field
 		var ptr int
+		if src.IsShape() {
+			// Shape types implement things they have already
+			// been typechecked to implement, even if they
+			// don't have the methods for them.
+			return ir.OCONVIFACE, ""
+		}
 		if implements(src, dst, &missing, &have, &ptr) {
-			// Call NeedITab/ITabAddr so that (src, dst)
-			// gets added to itabs early, which allows
-			// us to de-virtualize calls through this
-			// type/interface pair later. See CompileITabs in reflect.go
-			if types.IsDirectIface(src) && !dst.IsEmptyInterface() {
-				NeedITab(src, dst)
-			}
-
 			return ir.OCONVIFACE, ""
 		}
 
@@ -722,13 +727,23 @@ func ifacelookdot(s *types.Sym, t *types.Type, ignorecase bool) (m *types.Field,
 	return m, followptr
 }
 
+// implements reports whether t implements the interface iface. t can be
+// an interface, a type parameter, or a concrete type. If implements returns
+// false, it stores a method of iface that is not implemented in *m. If the
+// method name matches but the type is wrong, it additionally stores the type
+// of the method (on t) in *samename.
 func implements(t, iface *types.Type, m, samename **types.Field, ptr *int) bool {
 	t0 := t
 	if t == nil {
 		return false
 	}
 
-	if t.IsInterface() {
+	if t.IsInterface() || t.IsTypeParam() {
+		if t.IsTypeParam() {
+			// A typeparam satisfies an interface if its type bound
+			// has all the methods of that interface.
+			t = t.Bound()
+		}
 		i := 0
 		tms := t.AllMethods().Slice()
 		for _, im := range iface.AllMethods().Slice() {
@@ -874,3 +889,495 @@ var slist []symlink
 type symlink struct {
 	field *types.Field
 }
+
+// TypesOf converts a list of nodes to a list
+// of types of those nodes.
+func TypesOf(x []ir.Node) []*types.Type {
+	r := make([]*types.Type, len(x))
+	for i, n := range x {
+		r[i] = n.Type()
+	}
+	return r
+}
+
+// makeInstName1 returns the name of the generic function instantiated with the
+// given types, which can have type params or shapes, or be concrete types. name is
+// the name of the generic function or method.
+func makeInstName1(name string, targs []*types.Type, hasBrackets bool) string {
+	b := bytes.NewBufferString("")
+	i := strings.Index(name, "[")
+	assert(hasBrackets == (i >= 0))
+	if i >= 0 {
+		b.WriteString(name[0:i])
+	} else {
+		b.WriteString(name)
+	}
+	b.WriteString("[")
+	for i, targ := range targs {
+		if i > 0 {
+			b.WriteString(",")
+		}
+		// WriteString() does not include the package name for the local
+		// package, but we want it for uniqueness.
+		if targ.Sym() != nil && targ.Sym().Pkg == types.LocalPkg {
+			b.WriteString(targ.Sym().Pkg.Name)
+			b.WriteByte('.')
+		}
+		// types1 uses "interface {" and types2 uses "interface{" - convert
+		// to consistent types2 format.
+		tstring := targ.String()
+		tstring = strings.Replace(tstring, "interface {", "interface{", -1)
+		b.WriteString(tstring)
+	}
+	b.WriteString("]")
+	if i >= 0 {
+		i2 := strings.LastIndex(name[i:], "]")
+		assert(i2 >= 0)
+		b.WriteString(name[i+i2+1:])
+	}
+	if strings.HasPrefix(b.String(), ".inst..inst.") {
+		panic(fmt.Sprintf("multiple .inst. prefix in %s", b.String()))
+	}
+	return b.String()
+}
+
+// MakeInstName makes the unique name for a stenciled generic function or method,
+// based on the name of the function fnsym and the targs. It replaces any
+// existing bracket type list in the name. MakeInstName asserts that fnsym has
+// brackets in its name if and only if hasBrackets is true.
+//
+// Names of declared generic functions have no brackets originally, so hasBrackets
+// should be false. Names of generic methods already have brackets, since the new
+// type parameter is specified in the generic type of the receiver (e.g. func
+// (func (v *value[T]).set(...) { ... } has the original name (*value[T]).set.
+//
+// The standard naming is something like: 'genFn[int,bool]' for functions and
+// '(*genType[int,bool]).methodName' for methods
+func MakeInstName(gf *types.Sym, targs []*types.Type, hasBrackets bool) *types.Sym {
+	return gf.Pkg.Lookup(makeInstName1(gf.Name, targs, hasBrackets))
+}
+
+func MakeDictName(gf *types.Sym, targs []*types.Type, hasBrackets bool) *types.Sym {
+	for _, targ := range targs {
+		if targ.HasTParam() {
+			fmt.Printf("FUNCTION %s\n", gf.Name)
+			for _, targ := range targs {
+				fmt.Printf("  PARAM %+v\n", targ)
+			}
+			panic("dictionary should always have concrete type args")
+		}
+	}
+	name := makeInstName1(gf.Name, targs, hasBrackets)
+	name = ".dict." + name
+	return gf.Pkg.Lookup(name)
+}
+
+func assert(p bool) {
+	base.Assert(p)
+}
+
+// General type substituter, for replacing typeparams with type args.
+type Tsubster struct {
+	Tparams []*types.Type
+	Targs   []*types.Type
+	// If non-nil, the substitution map from name nodes in the generic function to the
+	// name nodes in the new stenciled function.
+	Vars map[*ir.Name]*ir.Name
+	// New fully-instantiated generic types whose methods should be instantiated.
+	InstTypeList []*types.Type
+	// If non-nil, function to substitute an incomplete (TFORW) type.
+	SubstForwFunc func(*types.Type) *types.Type
+}
+
+// Typ computes the type obtained by substituting any type parameter in t with the
+// corresponding type argument in subst. If t contains no type parameters, the
+// result is t; otherwise the result is a new type. It deals with recursive types
+// by using TFORW types and finding partially or fully created types via sym.Def.
+func (ts *Tsubster) Typ(t *types.Type) *types.Type {
+	if !t.HasTParam() && t.Kind() != types.TFUNC {
+		// Note: function types need to be copied regardless, as the
+		// types of closures may contain declarations that need
+		// to be copied. See #45738.
+		return t
+	}
+
+	if t.IsTypeParam() {
+		for i, tp := range ts.Tparams {
+			if tp == t {
+				return ts.Targs[i]
+			}
+		}
+		// If t is a simple typeparam T, then t has the name/symbol 'T'
+		// and t.Underlying() == t.
+		//
+		// However, consider the type definition: 'type P[T any] T'. We
+		// might use this definition so we can have a variant of type T
+		// that we can add new methods to. Suppose t is a reference to
+		// P[T]. t has the name 'P[T]', but its kind is TTYPEPARAM,
+		// because P[T] is defined as T. If we look at t.Underlying(), it
+		// is different, because the name of t.Underlying() is 'T' rather
+		// than 'P[T]'. But the kind of t.Underlying() is also TTYPEPARAM.
+		// In this case, we do the needed recursive substitution in the
+		// case statement below.
+		if t.Underlying() == t {
+			// t is a simple typeparam that didn't match anything in tparam
+			return t
+		}
+		// t is a more complex typeparam (e.g. P[T], as above, whose
+		// definition is just T).
+		assert(t.Sym() != nil)
+	}
+
+	var newsym *types.Sym
+	var neededTargs []*types.Type
+	var targsChanged bool
+	var forw *types.Type
+
+	if t.Sym() != nil {
+		// Translate the type params for this type according to
+		// the tparam/targs mapping from subst.
+		neededTargs = make([]*types.Type, len(t.RParams()))
+		for i, rparam := range t.RParams() {
+			neededTargs[i] = ts.Typ(rparam)
+			if !types.Identical(neededTargs[i], rparam) {
+				targsChanged = true
+			}
+		}
+		// For a named (defined) type, we have to change the name of the
+		// type as well. We do this first, so we can look up if we've
+		// already seen this type during this substitution or other
+		// definitions/substitutions.
+		genName := genericTypeName(t.Sym())
+		newsym = t.Sym().Pkg.Lookup(InstTypeName(genName, neededTargs))
+		if newsym.Def != nil {
+			// We've already created this instantiated defined type.
+			return newsym.Def.Type()
+		}
+
+		// In order to deal with recursive generic types, create a TFORW
+		// type initially and set the Def field of its sym, so it can be
+		// found if this type appears recursively within the type.
+		forw = NewIncompleteNamedType(t.Pos(), newsym)
+		//println("Creating new type by sub", newsym.Name, forw.HasTParam())
+		forw.SetRParams(neededTargs)
+		// Copy the OrigSym from the re-instantiated type (which is the sym of
+		// the base generic type).
+		assert(t.OrigSym != nil)
+		forw.OrigSym = t.OrigSym
+	}
+
+	var newt *types.Type
+
+	switch t.Kind() {
+	case types.TTYPEPARAM:
+		if t.Sym() == newsym && !targsChanged {
+			// The substitution did not change the type.
+			return t
+		}
+		// Substitute the underlying typeparam (e.g. T in P[T], see
+		// the example describing type P[T] above).
+		newt = ts.Typ(t.Underlying())
+		assert(newt != t)
+
+	case types.TARRAY:
+		elem := t.Elem()
+		newelem := ts.Typ(elem)
+		if newelem != elem || targsChanged {
+			newt = types.NewArray(newelem, t.NumElem())
+		}
+
+	case types.TPTR:
+		elem := t.Elem()
+		newelem := ts.Typ(elem)
+		if newelem != elem || targsChanged {
+			newt = types.NewPtr(newelem)
+		}
+
+	case types.TSLICE:
+		elem := t.Elem()
+		newelem := ts.Typ(elem)
+		if newelem != elem || targsChanged {
+			newt = types.NewSlice(newelem)
+		}
+
+	case types.TSTRUCT:
+		newt = ts.tstruct(t, targsChanged)
+		if newt == t {
+			newt = nil
+		}
+
+	case types.TFUNC:
+		newrecvs := ts.tstruct(t.Recvs(), false)
+		newparams := ts.tstruct(t.Params(), false)
+		newresults := ts.tstruct(t.Results(), false)
+		// Translate the tparams of a signature.
+		newtparams := ts.tstruct(t.TParams(), false)
+		if newrecvs != t.Recvs() || newparams != t.Params() ||
+			newresults != t.Results() || newtparams != t.TParams() || targsChanged {
+			// If any types have changed, then the all the fields of
+			// of recv, params, and results must be copied, because they have
+			// offset fields that are dependent, and so must have an
+			// independent copy for each new signature.
+			var newrecv *types.Field
+			if newrecvs.NumFields() > 0 {
+				if newrecvs == t.Recvs() {
+					newrecvs = ts.tstruct(t.Recvs(), true)
+				}
+				newrecv = newrecvs.Field(0)
+			}
+			if newparams == t.Params() {
+				newparams = ts.tstruct(t.Params(), true)
+			}
+			if newresults == t.Results() {
+				newresults = ts.tstruct(t.Results(), true)
+			}
+			var tparamfields []*types.Field
+			if newtparams.HasTParam() {
+				tparamfields = newtparams.FieldSlice()
+			} else {
+				// Completely remove the tparams from the resulting
+				// signature, if the tparams are now concrete types.
+				tparamfields = nil
+			}
+			newt = types.NewSignature(t.Pkg(), newrecv, tparamfields,
+				newparams.FieldSlice(), newresults.FieldSlice())
+		}
+
+	case types.TINTER:
+		newt = ts.tinter(t)
+		if newt == t && !targsChanged {
+			newt = nil
+		}
+
+	case types.TMAP:
+		newkey := ts.Typ(t.Key())
+		newval := ts.Typ(t.Elem())
+		if newkey != t.Key() || newval != t.Elem() || targsChanged {
+			newt = types.NewMap(newkey, newval)
+		}
+
+	case types.TCHAN:
+		elem := t.Elem()
+		newelem := ts.Typ(elem)
+		if newelem != elem || targsChanged {
+			newt = types.NewChan(newelem, t.ChanDir())
+			if !newt.HasTParam() {
+				// TODO(danscales): not sure why I have to do this
+				// only for channels.....
+				types.CheckSize(newt)
+			}
+		}
+	case types.TFORW:
+		if ts.SubstForwFunc != nil {
+			newt = ts.SubstForwFunc(t)
+		} else {
+			assert(false)
+		}
+	case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64,
+		types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64,
+		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128:
+		newt = t.Underlying()
+	case types.TUNION:
+		nt := t.NumTerms()
+		newterms := make([]*types.Type, nt)
+		tildes := make([]bool, nt)
+		changed := false
+		for i := 0; i < nt; i++ {
+			term, tilde := t.Term(i)
+			tildes[i] = tilde
+			newterms[i] = ts.Typ(term)
+			if newterms[i] != term {
+				changed = true
+			}
+		}
+		if changed {
+			newt = types.NewUnion(newterms, tildes)
+		}
+	default:
+		panic(fmt.Sprintf("Bad type in (*TSubster).Typ: %v", t.Kind()))
+	}
+	if newt == nil {
+		// Even though there were typeparams in the type, there may be no
+		// change if this is a function type for a function call (which will
+		// have its own tparams/targs in the function instantiation).
+		return t
+	}
+
+	if t.Sym() == nil && t.Kind() != types.TINTER {
+		// Not a named type or interface type, so there was no forwarding type
+		// and there are no methods to substitute.
+		assert(t.Methods().Len() == 0)
+		return newt
+	}
+
+	if forw != nil {
+		forw.SetUnderlying(newt)
+		newt = forw
+	}
+
+	if t.Kind() != types.TINTER && t.Methods().Len() > 0 {
+		// Fill in the method info for the new type.
+		var newfields []*types.Field
+		newfields = make([]*types.Field, t.Methods().Len())
+		for i, f := range t.Methods().Slice() {
+			t2 := ts.Typ(f.Type)
+			oldsym := f.Nname.Sym()
+			newsym := MakeInstName(oldsym, ts.Targs, true)
+			var nname *ir.Name
+			if newsym.Def != nil {
+				nname = newsym.Def.(*ir.Name)
+			} else {
+				nname = ir.NewNameAt(f.Pos, newsym)
+				nname.SetType(t2)
+				newsym.Def = nname
+			}
+			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
+			newfields[i].Nname = nname
+		}
+		newt.Methods().Set(newfields)
+		if !newt.HasTParam() && !newt.HasShape() {
+			// Generate all the methods for a new fully-instantiated type.
+			ts.InstTypeList = append(ts.InstTypeList, newt)
+		}
+	}
+	return newt
+}
+
+// tstruct substitutes type params in types of the fields of a structure type. For
+// each field, tstruct copies the Nname, and translates it if Nname is in
+// ts.vars. To always force the creation of a new (top-level) struct,
+// regardless of whether anything changed with the types or names of the struct's
+// fields, set force to true.
+func (ts *Tsubster) tstruct(t *types.Type, force bool) *types.Type {
+	if t.NumFields() == 0 {
+		if t.HasTParam() {
+			// For an empty struct, we need to return a new type,
+			// since it may now be fully instantiated (HasTParam
+			// becomes false).
+			return types.NewStruct(t.Pkg(), nil)
+		}
+		return t
+	}
+	var newfields []*types.Field
+	if force {
+		newfields = make([]*types.Field, t.NumFields())
+	}
+	for i, f := range t.Fields().Slice() {
+		t2 := ts.Typ(f.Type)
+		if (t2 != f.Type || f.Nname != nil) && newfields == nil {
+			newfields = make([]*types.Field, t.NumFields())
+			for j := 0; j < i; j++ {
+				newfields[j] = t.Field(j)
+			}
+		}
+		if newfields != nil {
+			// TODO(danscales): make sure this works for the field
+			// names of embedded types (which should keep the name of
+			// the type param, not the instantiated type).
+			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
+			newfields[i].Embedded = f.Embedded
+			if f.IsDDD() {
+				newfields[i].SetIsDDD(true)
+			}
+			if f.Nointerface() {
+				newfields[i].SetNointerface(true)
+			}
+			if f.Nname != nil && ts.Vars != nil {
+				v := ts.Vars[f.Nname.(*ir.Name)]
+				if v != nil {
+					// This is the case where we are
+					// translating the type of the function we
+					// are substituting, so its dcls are in
+					// the subst.ts.vars table, and we want to
+					// change to reference the new dcl.
+					newfields[i].Nname = v
+				} else {
+					// This is the case where we are
+					// translating the type of a function
+					// reference inside the function we are
+					// substituting, so we leave the Nname
+					// value as is.
+					newfields[i].Nname = f.Nname
+				}
+			}
+		}
+	}
+	if newfields != nil {
+		return types.NewStruct(t.Pkg(), newfields)
+	}
+	return t
+
+}
+
+// tinter substitutes type params in types of the methods of an interface type.
+func (ts *Tsubster) tinter(t *types.Type) *types.Type {
+	if t.Methods().Len() == 0 {
+		return t
+	}
+	var newfields []*types.Field
+	for i, f := range t.Methods().Slice() {
+		t2 := ts.Typ(f.Type)
+		if (t2 != f.Type || f.Nname != nil) && newfields == nil {
+			newfields = make([]*types.Field, t.Methods().Len())
+			for j := 0; j < i; j++ {
+				newfields[j] = t.Methods().Index(j)
+			}
+		}
+		if newfields != nil {
+			newfields[i] = types.NewField(f.Pos, f.Sym, t2)
+		}
+	}
+	if newfields != nil {
+		return types.NewInterface(t.Pkg(), newfields)
+	}
+	return t
+}
+
+// genericSym returns the name of the base generic type for the type named by
+// sym. It simply returns the name obtained by removing everything after the
+// first bracket ("[").
+func genericTypeName(sym *types.Sym) string {
+	return sym.Name[0:strings.Index(sym.Name, "[")]
+}
+
+// Shapify takes a concrete type and returns a GCshape type that can
+// be used in place of the input type and still generate identical code.
+// No methods are added - all methods calls directly on a shape should
+// be done by converting to an interface using the dictionary.
+//
+// TODO: this could take the generic function and base its decisions
+// on how that generic function uses this type argument. For instance,
+// if it doesn't use it as a function argument/return value, then
+// we don't need to distinguish int64 and float64 (because they only
+// differ in how they get passed as arguments). For now, we only
+// unify two different types if they are identical in every possible way.
+func Shapify(t *types.Type) *types.Type {
+	assert(!t.HasShape())
+	// Map all types with the same underlying type to the same shape.
+	u := t.Underlying()
+
+	// All pointers have the same shape.
+	// TODO: Make unsafe.Pointer the same shape as normal pointers.
+	if u.Kind() == types.TPTR {
+		u = types.Types[types.TUINT8].PtrTo()
+	}
+
+	if s := shaped[u]; s != nil {
+		return s
+	}
+
+	sym := shapePkg.Lookup(u.LinkString())
+	name := ir.NewDeclNameAt(u.Pos(), ir.OTYPE, sym)
+	s := types.NewNamed(name)
+	s.SetUnderlying(u)
+	s.SetIsShape(true)
+	s.SetHasShape(true)
+	name.SetType(s)
+	name.SetTypecheck(1)
+	shaped[u] = s
+	return s
+}
+
+var shaped = map[*types.Type]*types.Type{}
+
+var shapePkg = types.NewPkg(".shape", ".shape")
diff --git a/src/cmd/compile/internal/typecheck/syms.go b/src/cmd/compile/internal/typecheck/syms.go
index f29af82db2c..ed3aaecc5a2 100644
--- a/src/cmd/compile/internal/typecheck/syms.go
+++ b/src/cmd/compile/internal/typecheck/syms.go
@@ -75,9 +75,9 @@ func InitRuntime() {
 		typ := typs[d.typ]
 		switch d.tag {
 		case funcTag:
-			importfunc(ir.Pkgs.Runtime, src.NoXPos, sym, typ)
+			importfunc(src.NoXPos, sym, typ)
 		case varTag:
-			importvar(ir.Pkgs.Runtime, src.NoXPos, sym, typ)
+			importvar(src.NoXPos, sym, typ)
 		default:
 			base.Fatalf("unhandled declaration tag %v", d.tag)
 		}
diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index 95f7b50259f..db1b11c4cfd 100644
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -13,6 +13,7 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
+	"cmd/internal/src"
 )
 
 // Function collecting autotmps generated during typechecking,
@@ -24,7 +25,6 @@ var inimport bool // set during import
 var TypecheckAllowed bool
 
 var (
-	NeedITab        = func(t, itype *types.Type) {}
 	NeedRuntimeType = func(*types.Type) {}
 )
 
@@ -35,18 +35,10 @@ func Stmt(n ir.Node) ir.Node       { return typecheck(n, ctxStmt) }
 func Exprs(exprs []ir.Node) { typecheckslice(exprs, ctxExpr) }
 func Stmts(stmts []ir.Node) { typecheckslice(stmts, ctxStmt) }
 
-func Call(call *ir.CallExpr) {
-	t := call.X.Type()
-	if t == nil {
-		panic("misuse of Call")
-	}
-	ctx := ctxStmt
-	if t.NumResults() > 0 {
-		ctx = ctxExpr | ctxMultiOK
-	}
-	if typecheck(call, ctx) != call {
-		panic("bad typecheck")
-	}
+func Call(pos src.XPos, callee ir.Node, args []ir.Node, dots bool) ir.Node {
+	call := ir.NewCallExpr(pos, ir.OCALL, callee, args)
+	call.IsDDD = dots
+	return typecheck(call, ctxStmt|ctxExpr)
 }
 
 func Callee(n ir.Node) ir.Node {
@@ -59,8 +51,8 @@ func FuncBody(n *ir.Func) {
 	Stmts(n.Body)
 	CheckUnused(n)
 	CheckReturn(n)
-	if base.Errors() > errorsBefore {
-		n.Body = nil // type errors; do not compile
+	if ir.IsBlank(n.Nname) || base.Errors() > errorsBefore {
+		n.Body = nil // blank function or type errors; do not compile
 	}
 }
 
@@ -777,6 +769,10 @@ func typecheck1(n ir.Node, top int) ir.Node {
 		n := n.(*ir.CallExpr)
 		return tcRecover(n)
 
+	case ir.ORECOVERFP:
+		n := n.(*ir.CallExpr)
+		return tcRecoverFP(n)
+
 	case ir.OUNSAFEADD:
 		n := n.(*ir.BinaryExpr)
 		return tcUnsafeAdd(n)
@@ -787,11 +783,7 @@ func typecheck1(n ir.Node, top int) ir.Node {
 
 	case ir.OCLOSURE:
 		n := n.(*ir.ClosureExpr)
-		tcClosure(n, top)
-		if n.Type() == nil {
-			return n
-		}
-		return n
+		return tcClosure(n, top)
 
 	case ir.OITAB:
 		n := n.(*ir.UnaryExpr)
@@ -814,6 +806,14 @@ func typecheck1(n ir.Node, top int) ir.Node {
 		n.SetType(types.Types[types.TUINTPTR])
 		return n
 
+	case ir.OGETCALLERPC, ir.OGETCALLERSP:
+		n := n.(*ir.CallExpr)
+		if len(n.Args) != 0 {
+			base.FatalfAt(n.Pos(), "unexpected arguments: %v", n)
+		}
+		n.SetType(types.Types[types.TUINTPTR])
+		return n
+
 	case ir.OCONVNOP:
 		n := n.(*ir.ConvExpr)
 		n.X = Expr(n.X)
@@ -881,6 +881,10 @@ func typecheck1(n ir.Node, top int) ir.Node {
 		n := n.(*ir.TailCallStmt)
 		return n
 
+	case ir.OCHECKNIL:
+		n := n.(*ir.UnaryExpr)
+		return tcCheckNil(n)
+
 	case ir.OSELECT:
 		tcSelect(n.(*ir.SelectStmt))
 		return n
@@ -945,16 +949,18 @@ func typecheckargs(n ir.InitNode) {
 		return
 	}
 
-	// Rewrite f(g()) into t1, t2, ... = g(); f(t1, t2, ...).
-
 	// Save n as n.Orig for fmt.go.
 	if ir.Orig(n) == n {
 		n.(ir.OrigNode).SetOrig(ir.SepCopy(n))
 	}
 
-	as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil)
-	as.Rhs.Append(list...)
+	// Rewrite f(g()) into t1, t2, ... = g(); f(t1, t2, ...).
+	RewriteMultiValueCall(n, list[0])
+}
 
+// RewriteMultiValueCall rewrites multi-valued f() to use temporaries,
+// so the backend wouldn't need to worry about tuple-valued expressions.
+func RewriteMultiValueCall(n ir.InitNode, call ir.Node) {
 	// If we're outside of function context, then this call will
 	// be executed during the generated init function. However,
 	// init.go hasn't yet created it. Instead, associate the
@@ -964,25 +970,40 @@ func typecheckargs(n ir.InitNode) {
 	if static {
 		ir.CurFunc = InitTodoFunc
 	}
-	list = nil
-	for _, f := range t.FieldSlice() {
-		t := Temp(f.Type)
-		as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, t))
-		as.Lhs.Append(t)
-		list = append(list, t)
+
+	as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, []ir.Node{call})
+	results := call.Type().FieldSlice()
+	list := make([]ir.Node, len(results))
+	for i, result := range results {
+		tmp := Temp(result.Type)
+		as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, tmp))
+		as.Lhs.Append(tmp)
+		list[i] = tmp
 	}
 	if static {
 		ir.CurFunc = nil
 	}
 
+	n.PtrInit().Append(Stmt(as))
+
 	switch n := n.(type) {
+	default:
+		base.Fatalf("rewriteMultiValueCall %+v", n.Op())
 	case *ir.CallExpr:
 		n.Args = list
 	case *ir.ReturnStmt:
 		n.Results = list
+	case *ir.AssignListStmt:
+		if n.Op() != ir.OAS2FUNC {
+			base.Fatalf("rewriteMultiValueCall: invalid op %v", n.Op())
+		}
+		as.SetOp(ir.OAS2FUNC)
+		n.SetOp(ir.OAS2)
+		n.Rhs = make([]ir.Node, len(list))
+		for i, tmp := range list {
+			n.Rhs[i] = AssignConv(tmp, n.Lhs[i].Type(), "assignment")
+		}
 	}
-
-	n.PtrInit().Append(Stmt(as))
 }
 
 func checksliceindex(l ir.Node, r ir.Node, tp *types.Type) bool {
@@ -1443,15 +1464,22 @@ toomany:
 }
 
 func errorDetails(nl ir.Nodes, tstruct *types.Type, isddd bool) string {
-	// If we don't know any type at a call site, let's suppress any return
-	// message signatures. See Issue https://golang.org/issues/19012.
+	// Suppress any return message signatures if:
+	//
+	// (1) We don't know any type at a call site (see #19012).
+	// (2) Any node has an unknown type.
+	// (3) Invalid type for variadic parameter (see #46957).
 	if tstruct == nil {
-		return ""
+		return "" // case 1
 	}
-	// If any node has an unknown type, suppress it as well
+
+	if isddd && !nl[len(nl)-1].Type().IsSlice() {
+		return "" // case 3
+	}
+
 	for _, n := range nl {
 		if n.Type() == nil {
-			return ""
+			return "" // case 2
 		}
 	}
 	return fmt.Sprintf("\n\thave %s\n\twant %v", fmtSignature(nl, isddd), tstruct)
@@ -1889,11 +1917,6 @@ func typecheckdef(n *ir.Name) {
 					n.SetDiag(true)
 					goto ret
 				}
-				// For package-level type aliases, set n.Sym.Def so we can identify
-				// it as a type alias during export. See also #31959.
-				if n.Curfn == nil {
-					n.Sym().Def = n.Ntype
-				}
 			}
 			break
 		}
diff --git a/src/cmd/compile/internal/typecheck/universe.go b/src/cmd/compile/internal/typecheck/universe.go
index de185ab9447..54f3c89c245 100644
--- a/src/cmd/compile/internal/typecheck/universe.go
+++ b/src/cmd/compile/internal/typecheck/universe.go
@@ -158,6 +158,15 @@ func InitUniverse() {
 	s.Def = n
 	types.CalcSize(types.ErrorType)
 
+	// comparable type (interface)
+	s = types.BuiltinPkg.Lookup("comparable")
+	n = ir.NewDeclNameAt(src.NoXPos, ir.OTYPE, s)
+	types.ComparableType = types.NewNamed(n)
+	types.ComparableType.SetUnderlying(makeComparableInterface())
+	n.SetType(types.ComparableType)
+	s.Def = n
+	types.CalcSize(types.ComparableType)
+
 	types.Types[types.TUNSAFEPTR] = defBasic(types.TUNSAFEPTR, ir.Pkgs.Unsafe, "Pointer")
 
 	// simple aliases
@@ -338,6 +347,12 @@ func makeErrorInterface() *types.Type {
 	return types.NewInterface(types.NoPkg, []*types.Field{method})
 }
 
+func makeComparableInterface() *types.Type {
+	sig := types.NewSignature(types.NoPkg, fakeRecvField(), nil, nil, nil)
+	method := types.NewField(src.NoXPos, Lookup("=="), sig)
+	return types.NewInterface(types.NoPkg, []*types.Field{method})
+}
+
 // DeclareUniverse makes the universe block visible within the current package.
 func DeclareUniverse() {
 	// Operationally, this is similar to a dot import of builtinpkg, except
diff --git a/src/cmd/compile/internal/types/fmt.go b/src/cmd/compile/internal/types/fmt.go
index b538ea80542..0824f6d0936 100644
--- a/src/cmd/compile/internal/types/fmt.go
+++ b/src/cmd/compile/internal/types/fmt.go
@@ -109,14 +109,18 @@ func sconv(s *Sym, verb rune, mode fmtMode) string {
 		return ""
 	}
 
-	if s.Name == "_" {
-		return "_"
+	q := pkgqual(s.Pkg, verb, mode)
+	if q == "" {
+		return s.Name
 	}
+
 	buf := fmtBufferPool.Get().(*bytes.Buffer)
 	buf.Reset()
 	defer fmtBufferPool.Put(buf)
 
-	symfmt(buf, s, verb, mode)
+	buf.WriteString(q)
+	buf.WriteByte('.')
+	buf.WriteString(s.Name)
 	return InternString(buf.Bytes())
 }
 
@@ -128,56 +132,49 @@ func sconv2(b *bytes.Buffer, s *Sym, verb rune, mode fmtMode) {
 		b.WriteString("")
 		return
 	}
-	if s.Name == "_" {
-		b.WriteString("_")
-		return
-	}
 
 	symfmt(b, s, verb, mode)
 }
 
 func symfmt(b *bytes.Buffer, s *Sym, verb rune, mode fmtMode) {
+	if q := pkgqual(s.Pkg, verb, mode); q != "" {
+		b.WriteString(q)
+		b.WriteByte('.')
+	}
+	b.WriteString(s.Name)
+}
+
+// pkgqual returns the qualifier that should be used for printing
+// symbols from the given package in the given mode.
+// If it returns the empty string, no qualification is needed.
+func pkgqual(pkg *Pkg, verb rune, mode fmtMode) string {
 	if verb != 'S' {
 		switch mode {
 		case fmtGo: // This is for the user
-			if s.Pkg == BuiltinPkg || s.Pkg == LocalPkg {
-				b.WriteString(s.Name)
-				return
+			if pkg == BuiltinPkg || pkg == LocalPkg {
+				return ""
 			}
 
 			// If the name was used by multiple packages, display the full path,
-			if s.Pkg.Name != "" && NumImport[s.Pkg.Name] > 1 {
-				fmt.Fprintf(b, "%q.%s", s.Pkg.Path, s.Name)
-				return
+			if pkg.Name != "" && NumImport[pkg.Name] > 1 {
+				return strconv.Quote(pkg.Path)
 			}
-			b.WriteString(s.Pkg.Name)
-			b.WriteByte('.')
-			b.WriteString(s.Name)
-			return
+			return pkg.Name
 
 		case fmtDebug:
-			b.WriteString(s.Pkg.Name)
-			b.WriteByte('.')
-			b.WriteString(s.Name)
-			return
+			return pkg.Name
 
 		case fmtTypeIDName:
 			// dcommontype, typehash
-			b.WriteString(s.Pkg.Name)
-			b.WriteByte('.')
-			b.WriteString(s.Name)
-			return
+			return pkg.Name
 
 		case fmtTypeID:
 			// (methodsym), typesym, weaksym
-			b.WriteString(s.Pkg.Prefix)
-			b.WriteByte('.')
-			b.WriteString(s.Name)
-			return
+			return pkg.Prefix
 		}
 	}
 
-	b.WriteString(s.Name)
+	return ""
 }
 
 // Type
@@ -242,17 +239,37 @@ func (t *Type) String() string {
 	return tconv(t, 0, fmtGo)
 }
 
-// ShortString generates a short description of t.
-// It is used in autogenerated method names, reflection,
-// and itab names.
-func (t *Type) ShortString() string {
+// LinkString returns an unexpanded string description of t, suitable
+// for use in link symbols. "Unexpanded" here means that the
+// description uses `"".` to qualify identifiers from the current
+// package, and "expansion" refers to the renaming step performed by
+// the linker to replace these qualifiers with proper `path/to/pkg.`
+// qualifiers.
+//
+// After expansion, the description corresponds to type identity. That
+// is, for any pair of types t1 and t2, Identical(t1, t2) and
+// expand(t1.LinkString()) == expand(t2.LinkString()) report the same
+// value.
+//
+// Within a single compilation unit, LinkString always returns the
+// same unexpanded description for identical types. Thus it's safe to
+// use as a map key to implement a type-identity-keyed map. However,
+// make sure all LinkString calls used for this purpose happen within
+// the same compile process; the string keys are not stable across
+// multiple processes.
+func (t *Type) LinkString() string {
 	return tconv(t, 0, fmtTypeID)
 }
 
-// LongString generates a complete description of t.
-// It is useful for reflection,
-// or when a unique fingerprint or hash of a type is required.
-func (t *Type) LongString() string {
+// NameString generates a user-readable, mostly unique string
+// description of t. NameString always returns the same description
+// for identical types, even across compilation units.
+//
+// NameString qualifies identifiers by package name, so it has
+// collisions when different packages share the same names and
+// identifiers. It also does not distinguish function-scope defined
+// types from package-scoped defined types or from each other.
+func (t *Type) NameString() string {
 	return tconv(t, 0, fmtTypeIDName)
 }
 
@@ -319,31 +336,34 @@ func tconv2(b *bytes.Buffer, t *Type, verb rune, mode fmtMode, visited map[*Type
 
 	// Unless the 'L' flag was specified, if the type has a name, just print that name.
 	if verb != 'L' && t.Sym() != nil && t != Types[t.Kind()] {
-		switch mode {
-		case fmtTypeID, fmtTypeIDName:
-			if verb == 'S' {
-				if t.Vargen != 0 {
-					sconv2(b, t.Sym(), 'S', mode)
-					fmt.Fprintf(b, "·%d", t.Vargen)
-					return
-				}
-				sconv2(b, t.Sym(), 'S', mode)
-				return
-			}
-
-			if mode == fmtTypeIDName {
-				sconv2(b, t.Sym(), 'v', fmtTypeIDName)
-				return
-			}
-
-			if t.Sym().Pkg == LocalPkg && t.Vargen != 0 {
-				sconv2(b, t.Sym(), 'v', mode)
-				fmt.Fprintf(b, "·%d", t.Vargen)
-				return
-			}
+		// Default to 'v' if verb is invalid.
+		if verb != 'S' {
+			verb = 'v'
 		}
 
-		sconv2(b, t.Sym(), 'v', mode)
+		// In unified IR, function-scope defined types will have a ·N
+		// suffix embedded directly in their Name. Trim this off for
+		// non-fmtTypeID modes.
+		sym := t.Sym()
+		if mode != fmtTypeID {
+			i := len(sym.Name)
+			for i > 0 && sym.Name[i-1] >= '0' && sym.Name[i-1] <= '9' {
+				i--
+			}
+			const dot = "·"
+			if i >= len(dot) && sym.Name[i-len(dot):i] == dot {
+				sym = &Sym{Pkg: sym.Pkg, Name: sym.Name[:i-len(dot)]}
+			}
+		}
+		sconv2(b, sym, verb, mode)
+
+		// TODO(mdempsky): Investigate including Vargen in fmtTypeIDName
+		// output too. It seems like it should, but that mode is currently
+		// used in string representation used by reflection, which is
+		// user-visible and doesn't expect this.
+		if mode == fmtTypeID && t.Vargen != 0 {
+			fmt.Fprintf(b, "·%d", t.Vargen)
+		}
 		return
 	}
 
@@ -570,6 +590,18 @@ func tconv2(b *bytes.Buffer, t *Type, verb rune, mode fmtMode, visited map[*Type
 			b.WriteString(fmt.Sprintf("%p", t))
 		}
 
+	case TUNION:
+		for i := 0; i < t.NumTerms(); i++ {
+			if i > 0 {
+				b.WriteString("|")
+			}
+			elem, tilde := t.Term(i)
+			if tilde {
+				b.WriteString("~")
+			}
+			tconv2(b, elem, 0, mode, visited)
+		}
+
 	case Txxx:
 		b.WriteString("Txxx")
 
@@ -674,7 +706,7 @@ func FmtConst(v constant.Value, sharp bool) string {
 
 // TypeHash computes a hash value for type t to use in type switch statements.
 func TypeHash(t *Type) uint32 {
-	p := t.LongString()
+	p := t.NameString()
 
 	// Using MD5 is overkill, but reduces accidental collisions.
 	h := md5.Sum([]byte(p))
diff --git a/src/cmd/compile/internal/types/identity.go b/src/cmd/compile/internal/types/identity.go
index dde9f518568..2e9e2f4fd84 100644
--- a/src/cmd/compile/internal/types/identity.go
+++ b/src/cmd/compile/internal/types/identity.go
@@ -4,8 +4,11 @@
 
 package types
 
-// Identical reports whether t1 and t2 are identical types, following
-// the spec rules. Receiver parameter types are ignored.
+// Identical reports whether t1 and t2 are identical types, following the spec rules.
+// Receiver parameter types are ignored. Named (defined) types are only equal if they
+// are pointer-equal - i.e. there must be a unique types.Type for each specific named
+// type. Also, a type containing a shape type is considered identical to another type
+// (shape or not) if their underlying types are the same, or they are both pointers.
 func Identical(t1, t2 *Type) bool {
 	return identical(t1, t2, true, nil)
 }
@@ -29,6 +32,14 @@ func identical(t1, t2 *Type, cmpTags bool, assumedEqual map[typePair]struct{}) b
 		return false
 	}
 	if t1.sym != nil || t2.sym != nil {
+		if t1.HasShape() || t2.HasShape() {
+			switch t1.kind {
+			case TINT8, TUINT8, TINT16, TUINT16, TINT32, TUINT32, TINT64, TUINT64, TINT, TUINT, TUINTPTR, TCOMPLEX64, TCOMPLEX128, TFLOAT32, TFLOAT64, TBOOL, TSTRING, TPTR, TUNSAFEPTR:
+				return true
+			}
+			// fall through to unnamed type comparison for complex types.
+			goto cont
+		}
 		// Special case: we keep byte/uint8 and rune/int32
 		// separate for error messages. Treat them as equal.
 		switch t1.kind {
@@ -40,6 +51,7 @@ func identical(t1, t2 *Type, cmpTags bool, assumedEqual map[typePair]struct{}) b
 			return false
 		}
 	}
+cont:
 
 	// Any cyclic type must go through a named type, and if one is
 	// named, it is only identical to the other if they are the
diff --git a/src/cmd/compile/internal/types/kind_string.go b/src/cmd/compile/internal/types/kind_string.go
index ae24a58b921..3e6a8bc064e 100644
--- a/src/cmd/compile/internal/types/kind_string.go
+++ b/src/cmd/compile/internal/types/kind_string.go
@@ -38,20 +38,21 @@ func _() {
 	_ = x[TSTRING-27]
 	_ = x[TUNSAFEPTR-28]
 	_ = x[TTYPEPARAM-29]
-	_ = x[TIDEAL-30]
-	_ = x[TNIL-31]
-	_ = x[TBLANK-32]
-	_ = x[TFUNCARGS-33]
-	_ = x[TCHANARGS-34]
-	_ = x[TSSA-35]
-	_ = x[TTUPLE-36]
-	_ = x[TRESULTS-37]
-	_ = x[NTYPE-38]
+	_ = x[TUNION-30]
+	_ = x[TIDEAL-31]
+	_ = x[TNIL-32]
+	_ = x[TBLANK-33]
+	_ = x[TFUNCARGS-34]
+	_ = x[TCHANARGS-35]
+	_ = x[TSSA-36]
+	_ = x[TTUPLE-37]
+	_ = x[TRESULTS-38]
+	_ = x[NTYPE-39]
 }
 
-const _Kind_name = "xxxINT8UINT8INT16UINT16INT32UINT32INT64UINT64INTUINTUINTPTRCOMPLEX64COMPLEX128FLOAT32FLOAT64BOOLPTRFUNCSLICEARRAYSTRUCTCHANMAPINTERFORWANYSTRINGUNSAFEPTRTYPEPARAMIDEALNILBLANKFUNCARGSCHANARGSSSATUPLERESULTSNTYPE"
+const _Kind_name = "xxxINT8UINT8INT16UINT16INT32UINT32INT64UINT64INTUINTUINTPTRCOMPLEX64COMPLEX128FLOAT32FLOAT64BOOLPTRFUNCSLICEARRAYSTRUCTCHANMAPINTERFORWANYSTRINGUNSAFEPTRTYPEPARAMUNIONIDEALNILBLANKFUNCARGSCHANARGSSSATUPLERESULTSNTYPE"
 
-var _Kind_index = [...]uint8{0, 3, 7, 12, 17, 23, 28, 34, 39, 45, 48, 52, 59, 68, 78, 85, 92, 96, 99, 103, 108, 113, 119, 123, 126, 131, 135, 138, 144, 153, 162, 167, 170, 175, 183, 191, 194, 199, 206, 211}
+var _Kind_index = [...]uint8{0, 3, 7, 12, 17, 23, 28, 34, 39, 45, 48, 52, 59, 68, 78, 85, 92, 96, 99, 103, 108, 113, 119, 123, 126, 131, 135, 138, 144, 153, 162, 167, 172, 175, 180, 188, 196, 199, 204, 211, 216}
 
 func (i Kind) String() string {
 	if i >= Kind(len(_Kind_index)-1) {
diff --git a/src/cmd/compile/internal/types/pkg.go b/src/cmd/compile/internal/types/pkg.go
index a6d2e2007b0..f63a357f0d0 100644
--- a/src/cmd/compile/internal/types/pkg.go
+++ b/src/cmd/compile/internal/types/pkg.go
@@ -137,7 +137,3 @@ func CleanroomDo(f func()) {
 	f()
 	pkgMap = saved
 }
-
-func IsDotAlias(sym *Sym) bool {
-	return sym.Def != nil && sym.Def.Sym() != sym
-}
diff --git a/src/cmd/compile/internal/types/size.go b/src/cmd/compile/internal/types/size.go
index f0e695ab964..89391ade683 100644
--- a/src/cmd/compile/internal/types/size.go
+++ b/src/cmd/compile/internal/types/size.go
@@ -90,6 +90,26 @@ func expandiface(t *Type) {
 		methods = append(methods, m)
 	}
 
+	{
+		methods := t.Methods().Slice()
+		sort.SliceStable(methods, func(i, j int) bool {
+			mi, mj := methods[i], methods[j]
+
+			// Sort embedded types by type name (if any).
+			if mi.Sym == nil && mj.Sym == nil {
+				return mi.Type.Sym().Less(mj.Type.Sym())
+			}
+
+			// Sort methods before embedded types.
+			if mi.Sym == nil || mj.Sym == nil {
+				return mi.Sym != nil
+			}
+
+			// Sort methods by symbol name.
+			return mi.Sym.Less(mj.Sym)
+		})
+	}
+
 	for _, m := range t.Methods().Slice() {
 		if m.Sym == nil {
 			continue
@@ -104,8 +124,17 @@ func expandiface(t *Type) {
 			continue
 		}
 
+		if m.Type.IsUnion() {
+			continue
+		}
+
+		// In 1.18, embedded types can be anything. In Go 1.17, we disallow
+		// embedding anything other than interfaces.
 		if !m.Type.IsInterface() {
-			base.ErrorfAt(m.Pos, "interface contains embedded non-interface %v", m.Type)
+			if AllowsGoVersion(t.Pkg(), 1, 18) {
+				continue
+			}
+			base.ErrorfAt(m.Pos, "interface contains embedded non-interface, non-union %v", m.Type)
 			m.SetBroke(true)
 			t.SetBroke(true)
 			// Add to fields so that error messages
@@ -120,10 +149,15 @@ func expandiface(t *Type) {
 		// (including broken ones, if any) and add to t's
 		// method set.
 		for _, t1 := range m.Type.AllMethods().Slice() {
-			// Use m.Pos rather than t1.Pos to preserve embedding position.
 			f := NewField(m.Pos, t1.Sym, t1.Type)
 			addMethod(f, false)
+
+			// Clear position after typechecking, for consistency with types2.
+			f.Pos = src.NoXPos
 		}
+
+		// Clear position after typechecking, for consistency with types2.
+		m.Pos = src.NoXPos
 	}
 
 	sort.Sort(MethodsByName(methods))
@@ -405,6 +439,12 @@ func CalcSize(t *Type) {
 		t.Align = uint8(PtrSize)
 		expandiface(t)
 
+	case TUNION:
+		// Always part of an interface for now, so size/align don't matter.
+		// Pretend a union is represented like an interface.
+		w = 2 * int64(PtrSize)
+		t.Align = uint8(PtrSize)
+
 	case TCHAN: // implemented as pointer
 		w = int64(PtrSize)
 
diff --git a/src/cmd/compile/internal/types/sizeof_test.go b/src/cmd/compile/internal/types/sizeof_test.go
index 70289387421..7349e52a73e 100644
--- a/src/cmd/compile/internal/types/sizeof_test.go
+++ b/src/cmd/compile/internal/types/sizeof_test.go
@@ -21,7 +21,7 @@ func TestSizeof(t *testing.T) {
 		_64bit uintptr     // size on 64bit platforms
 	}{
 		{Sym{}, 44, 72},
-		{Type{}, 60, 104},
+		{Type{}, 64, 112},
 		{Map{}, 20, 40},
 		{Forward{}, 20, 32},
 		{Func{}, 28, 48},
diff --git a/src/cmd/compile/internal/types/sort.go b/src/cmd/compile/internal/types/sort.go
index dc59b064153..765c070cd94 100644
--- a/src/cmd/compile/internal/types/sort.go
+++ b/src/cmd/compile/internal/types/sort.go
@@ -4,11 +4,16 @@
 
 package types
 
-// MethodsByName sorts methods by symbol.
+// MethodsByName sorts methods by name.
 type MethodsByName []*Field
 
-func (x MethodsByName) Len() int { return len(x) }
-
-func (x MethodsByName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
-
+func (x MethodsByName) Len() int           { return len(x) }
+func (x MethodsByName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 func (x MethodsByName) Less(i, j int) bool { return x[i].Sym.Less(x[j].Sym) }
+
+// EmbeddedsByName sorts embedded types by name.
+type EmbeddedsByName []*Field
+
+func (x EmbeddedsByName) Len() int           { return len(x) }
+func (x EmbeddedsByName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x EmbeddedsByName) Less(i, j int) bool { return x[i].Type.Sym().Less(x[j].Type.Sym()) }
diff --git a/src/cmd/compile/internal/types/sym.go b/src/cmd/compile/internal/types/sym.go
index 534cf7e2376..fb642f52f88 100644
--- a/src/cmd/compile/internal/types/sym.go
+++ b/src/cmd/compile/internal/types/sym.go
@@ -110,6 +110,14 @@ func (a *Sym) Less(b *Sym) bool {
 		return false
 	}
 
+	// Nil before non-nil.
+	if a == nil {
+		return true
+	}
+	if b == nil {
+		return false
+	}
+
 	// Exported symbols before non-exported.
 	ea := IsExported(a.Name)
 	eb := IsExported(b.Name)
diff --git a/src/cmd/compile/internal/types/type.go b/src/cmd/compile/internal/types/type.go
index 1a9aa6916a2..875b0ba82f1 100644
--- a/src/cmd/compile/internal/types/type.go
+++ b/src/cmd/compile/internal/types/type.go
@@ -8,6 +8,7 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/internal/src"
 	"fmt"
+	"strings"
 	"sync"
 )
 
@@ -73,6 +74,7 @@ const (
 	TSTRING
 	TUNSAFEPTR
 	TTYPEPARAM
+	TUNION
 
 	// pseudo-types for literals
 	TIDEAL // untyped numeric constants
@@ -121,6 +123,8 @@ var (
 
 	// Predeclared error interface type.
 	ErrorType *Type
+	// Predeclared comparable interface type.
+	ComparableType *Type
 
 	// Types to represent untyped string and boolean constants.
 	UntypedString = New(TSTRING)
@@ -151,7 +155,7 @@ type Type struct {
 	// TARRAY: *Array
 	// TSLICE: Slice
 	// TSSA: string
-	// TTYPEPARAM:  *Interface (though we may not need to store/use the Interface info)
+	// TTYPEPARAM:  *Typeparam
 	Extra interface{}
 
 	// Width is the width of this Type in bytes.
@@ -182,12 +186,19 @@ type Type struct {
 	flags bitset8
 
 	// For defined (named) generic types, a pointer to the list of type params
-	// (in order) of this type that need to be instantiated. For
-	// fully-instantiated generic types, this is the targs used to instantiate
-	// them (which are used when generating the corresponding instantiated
-	// methods). rparams is only set for named types that are generic or are
-	// fully-instantiated from a generic type, and is otherwise set to nil.
+	// (in order) of this type that need to be instantiated. For instantiated
+	// generic types, this is the targs used to instantiate them. These targs
+	// may be typeparams (for re-instantiated types such as Value[T2]) or
+	// concrete types (for fully instantiated types such as Value[int]).
+	// rparams is only set for named types that are generic or are fully
+	// instantiated from a generic type, and is otherwise set to nil.
+	// TODO(danscales): choose a better name.
 	rparams *[]*Type
+
+	// For an instantiated generic type, the symbol for the base generic type.
+	// This backpointer is useful, because the base type is the type that has
+	// the method bodies.
+	OrigSym *Sym
 }
 
 func (*Type) CanBeAnSSAAux() {}
@@ -199,6 +210,8 @@ const (
 	typeDeferwidth             // width computation has been deferred and type is on deferredTypeStack
 	typeRecur
 	typeHasTParam // there is a typeparam somewhere in the type (generic function or type)
+	typeIsShape   // represents a set of closely related types, for generics
+	typeHasShape  // there is a shape somewhere in the type
 )
 
 func (t *Type) NotInHeap() bool  { return t.flags&typeNotInHeap != 0 }
@@ -207,13 +220,21 @@ func (t *Type) Noalg() bool      { return t.flags&typeNoalg != 0 }
 func (t *Type) Deferwidth() bool { return t.flags&typeDeferwidth != 0 }
 func (t *Type) Recur() bool      { return t.flags&typeRecur != 0 }
 func (t *Type) HasTParam() bool  { return t.flags&typeHasTParam != 0 }
+func (t *Type) IsShape() bool    { return t.flags&typeIsShape != 0 }
+func (t *Type) HasShape() bool   { return t.flags&typeHasShape != 0 }
 
 func (t *Type) SetNotInHeap(b bool)  { t.flags.set(typeNotInHeap, b) }
 func (t *Type) SetBroke(b bool)      { t.flags.set(typeBroke, b) }
 func (t *Type) SetNoalg(b bool)      { t.flags.set(typeNoalg, b) }
 func (t *Type) SetDeferwidth(b bool) { t.flags.set(typeDeferwidth, b) }
 func (t *Type) SetRecur(b bool)      { t.flags.set(typeRecur, b) }
-func (t *Type) SetHasTParam(b bool)  { t.flags.set(typeHasTParam, b) }
+
+// Generic types should never have alg functions.
+func (t *Type) SetHasTParam(b bool) { t.flags.set(typeHasTParam, b); t.flags.set(typeNoalg, b) }
+
+// Should always do SetHasShape(true) when doing SeIsShape(true).
+func (t *Type) SetIsShape(b bool)  { t.flags.set(typeIsShape, b) }
+func (t *Type) SetHasShape(b bool) { t.flags.set(typeHasShape, b) }
 
 // Kind returns the kind of type t.
 func (t *Type) Kind() Kind { return t.kind }
@@ -255,9 +276,6 @@ func (t *Type) SetRParams(rparams []*Type) {
 		base.Fatalf("Setting nil or zero-length rparams")
 	}
 	t.rparams = &rparams
-	if t.HasTParam() {
-		return
-	}
 	// HasTParam should be set if any rparam is or has a type param. This is
 	// to handle the case of a generic type which doesn't reference any of its
 	// type params (e.g. most commonly, an empty struct).
@@ -266,9 +284,33 @@ func (t *Type) SetRParams(rparams []*Type) {
 			t.SetHasTParam(true)
 			break
 		}
+		if rparam.HasShape() {
+			t.SetHasShape(true)
+			break
+		}
 	}
 }
 
+// IsBaseGeneric returns true if t is a generic type (not reinstantiated with
+// another type params or fully instantiated.
+func (t *Type) IsBaseGeneric() bool {
+	return len(t.RParams()) > 0 && strings.Index(t.Sym().Name, "[") < 0
+}
+
+// IsInstantiatedGeneric returns t if t ia generic type that has been
+// reinstantiated with new typeparams (i.e. is not fully instantiated).
+func (t *Type) IsInstantiatedGeneric() bool {
+	return len(t.RParams()) > 0 && strings.Index(t.Sym().Name, "[") >= 0 &&
+		t.HasTParam()
+}
+
+// IsFullyInstantiated reports whether t is a fully instantiated generic type; i.e. an
+// instantiated generic type where all type arguments are non-generic or fully
+// instantiated generic types.
+func (t *Type) IsFullyInstantiated() bool {
+	return len(t.RParams()) > 0 && !t.HasTParam()
+}
+
 // NoPkg is a nil *Pkg value for clarity.
 // It's intended for use when constructing types that aren't exported
 // and thus don't need to be associated with any package.
@@ -377,6 +419,18 @@ type Interface struct {
 	pkg *Pkg
 }
 
+// Typeparam contains Type fields specific to typeparam types.
+type Typeparam struct {
+	index int // type parameter index in source order, starting at 0
+	bound *Type
+}
+
+// Union contains Type fields specific to union types.
+type Union struct {
+	terms  []*Type
+	tildes []bool // whether terms[i] is of form ~T
+}
+
 // Ptr contains Type fields specific to pointer types.
 type Ptr struct {
 	Elem *Type // element type
@@ -558,7 +612,9 @@ func New(et Kind) *Type {
 	case TRESULTS:
 		t.Extra = new(Results)
 	case TTYPEPARAM:
-		t.Extra = new(Interface)
+		t.Extra = new(Typeparam)
+	case TUNION:
+		t.Extra = new(Union)
 	}
 	return t
 }
@@ -574,6 +630,9 @@ func NewArray(elem *Type, bound int64) *Type {
 	if elem.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if elem.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -592,6 +651,9 @@ func NewSlice(elem *Type) *Type {
 	if elem.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if elem.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -604,6 +666,9 @@ func NewChan(elem *Type, dir ChanDir) *Type {
 	if elem.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if elem.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -614,6 +679,9 @@ func NewTuple(t1, t2 *Type) *Type {
 	if t1.HasTParam() || t2.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if t1.HasShape() || t2.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -645,6 +713,9 @@ func NewMap(k, v *Type) *Type {
 	if k.HasTParam() || v.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if k.HasShape() || v.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -669,6 +740,9 @@ func NewPtr(elem *Type) *Type {
 			// when this entry was cached.
 			t.SetHasTParam(true)
 		}
+		if elem.HasShape() {
+			t.SetHasShape(true)
+		}
 		return t
 	}
 
@@ -682,6 +756,9 @@ func NewPtr(elem *Type) *Type {
 	if elem.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if elem.HasShape() {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -825,6 +902,8 @@ func (t *Type) copy() *Type {
 	case TARRAY:
 		x := *t.Extra.(*Array)
 		nt.Extra = &x
+	case TTYPEPARAM:
+		base.Fatalf("typeparam types cannot be copied")
 	case TTUPLE, TSSA, TRESULTS:
 		base.Fatalf("ssa types cannot be copied")
 	}
@@ -925,7 +1004,7 @@ func (t *Type) FuncArgs() *Type {
 	return t.Extra.(FuncArgs).T
 }
 
-// IsFuncArgStruct reports whether t is a struct representing function parameters.
+// IsFuncArgStruct reports whether t is a struct representing function parameters or results.
 func (t *Type) IsFuncArgStruct() bool {
 	return t.kind == TSTRUCT && t.Extra.(*Struct).Funarg != FunargNone
 }
@@ -1436,6 +1515,14 @@ func (t *Type) IsInterface() bool {
 	return t.kind == TINTER
 }
 
+func (t *Type) IsUnion() bool {
+	return t.kind == TUNION
+}
+
+func (t *Type) IsTypeParam() bool {
+	return t.kind == TTYPEPARAM
+}
+
 // IsEmptyInterface reports whether t is an empty interface type.
 func (t *Type) IsEmptyInterface() bool {
 	return t.IsInterface() && t.AllMethods().Len() == 0
@@ -1708,6 +1795,9 @@ func (t *Type) SetUnderlying(underlying *Type) {
 	if underlying.HasTParam() {
 		t.SetHasTParam(true)
 	}
+	if underlying.HasShape() {
+		t.SetHasShape(true)
+	}
 
 	// spec: "The declared type does not inherit any methods bound
 	// to the existing type, but the method set of an interface
@@ -1739,6 +1829,15 @@ func fieldsHasTParam(fields []*Field) bool {
 	return false
 }
 
+func fieldsHasShape(fields []*Field) bool {
+	for _, f := range fields {
+		if f.Type != nil && f.Type.HasShape() {
+			return true
+		}
+	}
+	return false
+}
+
 // NewBasic returns a new basic type of the given kind.
 func NewBasic(kind Kind, obj Object) *Type {
 	t := New(kind)
@@ -1758,6 +1857,10 @@ func NewInterface(pkg *Pkg, methods []*Field) *Type {
 			t.SetHasTParam(true)
 			break
 		}
+		if f.Type != nil && f.Type.HasShape() {
+			t.SetHasShape(true)
+			break
+		}
 	}
 	if anyBroke(methods) {
 		t.SetBroke(true)
@@ -1766,14 +1869,75 @@ func NewInterface(pkg *Pkg, methods []*Field) *Type {
 	return t
 }
 
-// NewTypeParam returns a new type param.
-func NewTypeParam(pkg *Pkg) *Type {
+// NewTypeParam returns a new type param with the specified sym (package and name)
+// and specified index within the typeparam list.
+func NewTypeParam(sym *Sym, index int) *Type {
 	t := New(TTYPEPARAM)
-	t.Extra.(*Interface).pkg = pkg
+	t.sym = sym
+	t.Extra.(*Typeparam).index = index
 	t.SetHasTParam(true)
 	return t
 }
 
+// Index returns the index of the type param within its param list.
+func (t *Type) Index() int {
+	t.wantEtype(TTYPEPARAM)
+	return t.Extra.(*Typeparam).index
+}
+
+// SetIndex sets the index of the type param within its param list.
+func (t *Type) SetIndex(i int) {
+	t.wantEtype(TTYPEPARAM)
+	t.Extra.(*Typeparam).index = i
+}
+
+// SetBound sets the bound of a typeparam.
+func (t *Type) SetBound(bound *Type) {
+	t.wantEtype(TTYPEPARAM)
+	t.Extra.(*Typeparam).bound = bound
+}
+
+// Bound returns the bound of a typeparam.
+func (t *Type) Bound() *Type {
+	t.wantEtype(TTYPEPARAM)
+	return t.Extra.(*Typeparam).bound
+}
+
+// NewUnion returns a new union with the specified set of terms (types). If
+// tildes[i] is true, then terms[i] represents ~T, rather than just T.
+func NewUnion(terms []*Type, tildes []bool) *Type {
+	t := New(TUNION)
+	if len(terms) != len(tildes) {
+		base.Fatalf("Mismatched terms and tildes for NewUnion")
+	}
+	t.Extra.(*Union).terms = terms
+	t.Extra.(*Union).tildes = tildes
+	nt := len(terms)
+	for i := 0; i < nt; i++ {
+		if terms[i].HasTParam() {
+			t.SetHasTParam(true)
+		}
+		if terms[i].HasShape() {
+			t.SetHasShape(true)
+		}
+	}
+	return t
+}
+
+// NumTerms returns the number of terms in a union type.
+func (t *Type) NumTerms() int {
+	t.wantEtype(TUNION)
+	return len(t.Extra.(*Union).terms)
+}
+
+// Term returns ith term of a union type as (term, tilde). If tilde is true, term
+// represents ~T, rather than just T.
+func (t *Type) Term(i int) (*Type, bool) {
+	t.wantEtype(TUNION)
+	u := t.Extra.(*Union)
+	return u.terms[i], u.tildes[i]
+}
+
 const BOGUS_FUNARG_OFFSET = -1000000000
 
 func unzeroFieldOffsets(f []*Field) {
@@ -1817,6 +1981,9 @@ func NewSignature(pkg *Pkg, recv *Field, tparams, params, results []*Field) *Typ
 		fieldsHasTParam(results) {
 		t.SetHasTParam(true)
 	}
+	if fieldsHasShape(recvs) || fieldsHasShape(params) || fieldsHasShape(results) {
+		t.SetHasShape(true)
+	}
 
 	return t
 }
@@ -1832,6 +1999,9 @@ func NewStruct(pkg *Pkg, fields []*Field) *Type {
 	if fieldsHasTParam(fields) {
 		t.SetHasTParam(true)
 	}
+	if fieldsHasShape(fields) {
+		t.SetHasShape(true)
+	}
 	return t
 }
 
@@ -2028,7 +2198,7 @@ func TypeSymLookup(name string) *Sym {
 }
 
 func TypeSymName(t *Type) string {
-	name := t.ShortString()
+	name := t.LinkString()
 	// Use a separate symbol name for Noalg types for #17752.
 	if TypeHasNoAlg(t) {
 		name = "noalg." + name
diff --git a/src/cmd/compile/internal/types2/api.go b/src/cmd/compile/internal/types2/api.go
index 2939dcc0bdf..ae4fb6ad109 100644
--- a/src/cmd/compile/internal/types2/api.go
+++ b/src/cmd/compile/internal/types2/api.go
@@ -125,6 +125,12 @@ type Config struct {
 	// TODO(gri) Consolidate error messages and remove this flag.
 	CompilerErrorMessages bool
 
+	// If AllowTypeLists is set, the type list syntax is permitted
+	// in an interface in addition to the type set syntax.
+	// TODO(gri) Remove once type lists are no longer supported by
+	//           the parser.
+	AllowTypeLists bool
+
 	// If go115UsesCgo is set, the type checker expects the
 	// _cgo_gotypes.go file generated by running cmd/cgo to be
 	// provided as a package source file. Qualified identifiers
@@ -355,7 +361,7 @@ func (tv TypeAndValue) HasOk() bool {
 // Inferred reports the inferred type arguments and signature
 // for a parameterized function call that uses type inference.
 type Inferred struct {
-	Targs []Type
+	TArgs []Type
 	Sig   *Signature
 }
 
@@ -424,11 +430,11 @@ func Implements(V Type, T *Interface) bool {
 // Identical reports whether x and y are identical types.
 // Receivers of Signature types are ignored.
 func Identical(x, y Type) bool {
-	return (*Checker)(nil).identical(x, y)
+	return identical(x, y, true, nil)
 }
 
 // IdenticalIgnoreTags reports whether x and y are identical types if tags are ignored.
 // Receivers of Signature types are ignored.
 func IdenticalIgnoreTags(x, y Type) bool {
-	return (*Checker)(nil).identicalIgnoreTags(x, y)
+	return identical(x, y, false, nil)
 }
diff --git a/src/cmd/compile/internal/types2/api_test.go b/src/cmd/compile/internal/types2/api_test.go
index 873390c1e92..be05d06fd0a 100644
--- a/src/cmd/compile/internal/types2/api_test.go
+++ b/src/cmd/compile/internal/types2/api_test.go
@@ -329,27 +329,26 @@ func TestTypesInfo(t *testing.T) {
 		{brokenPkg + `x5; func _() { var x map[string][...]int; x = map[string][...]int{"": {1,2,3}} }`, `x`, `map[string]invalid type`},
 
 		// parameterized functions
-		{genericPkg + `p0; func f[T any](T); var _ = f[int]`, `f`, `func[T₁ interface{}](T₁)`},
-		{genericPkg + `p1; func f[T any](T); var _ = f[int]`, `f[int]`, `func(int)`},
-		{genericPkg + `p2; func f[T any](T); func _() { f(42) }`, `f`, `func[T₁ interface{}](T₁)`},
-		{genericPkg + `p3; func f[T any](T); func _() { f(42) }`, `f(42)`, `()`},
+		{genericPkg + `p0; func f[T any](T) {}; var _ = f[int]`, `f`, `func[generic_p0.T₁ interface{}](generic_p0.T₁)`},
+		{genericPkg + `p1; func f[T any](T) {}; var _ = f[int]`, `f[int]`, `func(int)`},
+		{genericPkg + `p2; func f[T any](T) {}; func _() { f(42) }`, `f`, `func[generic_p2.T₁ interface{}](generic_p2.T₁)`},
+		{genericPkg + `p3; func f[T any](T) {}; func _() { f(42) }`, `f(42)`, `()`},
 
 		// type parameters
 		{genericPkg + `t0; type t[] int; var _ t`, `t`, `generic_t0.t`}, // t[] is a syntax error that is ignored in this test in favor of t
-		{genericPkg + `t1; type t[P any] int; var _ t[int]`, `t`, `generic_t1.t[P₁ interface{}]`},
-		{genericPkg + `t2; type t[P interface{}] int; var _ t[int]`, `t`, `generic_t2.t[P₁ interface{}]`},
-		{genericPkg + `t3; type t[P, Q interface{}] int; var _ t[int, int]`, `t`, `generic_t3.t[P₁, Q₂ interface{}]`},
-		{brokenPkg + `t4; type t[P, Q interface{ m() }] int; var _ t[int, int]`, `t`, `broken_t4.t[P₁, Q₂ interface{m()}]`},
+		{genericPkg + `t1; type t[P any] int; var _ t[int]`, `t`, `generic_t1.t[generic_t1.P₁ interface{}]`},
+		{genericPkg + `t2; type t[P interface{}] int; var _ t[int]`, `t`, `generic_t2.t[generic_t2.P₁ interface{}]`},
+		{genericPkg + `t3; type t[P, Q interface{}] int; var _ t[int, int]`, `t`, `generic_t3.t[generic_t3.P₁, generic_t3.Q₂ interface{}]`},
+		{brokenPkg + `t4; type t[P, Q interface{ m() }] int; var _ t[int, int]`, `t`, `broken_t4.t[broken_t4.P₁, broken_t4.Q₂ interface{m()}]`},
 
 		// instantiated types must be sanitized
 		{genericPkg + `g0; type t[P any] int; var x struct{ f t[int] }; var _ = x.f`, `x.f`, `generic_g0.t[int]`},
 
 		// issue 45096
-		{genericPkg + `issue45096; func _[T interface{ type int8, int16, int32  }](x T) { _ = x < 0 }`, `0`, `T₁`},
+		{genericPkg + `issue45096; func _[T interface{ ~int8 | ~int16 | ~int32 }](x T) { _ = x < 0 }`, `0`, `generic_issue45096.T₁`},
 	}
 
 	for _, test := range tests {
-		ResetId() // avoid renumbering of type parameter ids when adding tests
 		info := Info{Types: make(map[syntax.Expr]TypeAndValue)}
 		var name string
 		if strings.HasPrefix(test.src, brokenPkg) {
@@ -390,60 +389,60 @@ func TestInferredInfo(t *testing.T) {
 		targs []string
 		sig   string
 	}{
-		{genericPkg + `p0; func f[T any](T); func _() { f(42) }`,
+		{genericPkg + `p0; func f[T any](T) {}; func _() { f(42) }`,
 			`f`,
 			[]string{`int`},
 			`func(int)`,
 		},
-		{genericPkg + `p1; func f[T any](T) T; func _() { f('@') }`,
+		{genericPkg + `p1; func f[T any](T) T { panic(0) }; func _() { f('@') }`,
 			`f`,
 			[]string{`rune`},
 			`func(rune) rune`,
 		},
-		{genericPkg + `p2; func f[T any](...T) T; func _() { f(0i) }`,
+		{genericPkg + `p2; func f[T any](...T) T { panic(0) }; func _() { f(0i) }`,
 			`f`,
 			[]string{`complex128`},
 			`func(...complex128) complex128`,
 		},
-		{genericPkg + `p3; func f[A, B, C any](A, *B, []C); func _() { f(1.2, new(string), []byte{}) }`,
+		{genericPkg + `p3; func f[A, B, C any](A, *B, []C) {}; func _() { f(1.2, new(string), []byte{}) }`,
 			`f`,
 			[]string{`float64`, `string`, `byte`},
 			`func(float64, *string, []byte)`,
 		},
-		{genericPkg + `p4; func f[A, B any](A, *B, ...[]B); func _() { f(1.2, new(byte)) }`,
+		{genericPkg + `p4; func f[A, B any](A, *B, ...[]B) {}; func _() { f(1.2, new(byte)) }`,
 			`f`,
 			[]string{`float64`, `byte`},
 			`func(float64, *byte, ...[]byte)`,
 		},
 
 		// we don't know how to translate these but we can type-check them
-		{genericPkg + `q0; type T struct{}; func (T) m[P any](P); func _(x T) { x.m(42) }`,
+		{genericPkg + `q0; type T struct{}; func (T) m[P any](P) {}; func _(x T) { x.m(42) }`,
 			`x.m`,
 			[]string{`int`},
 			`func(int)`,
 		},
-		{genericPkg + `q1; type T struct{}; func (T) m[P any](P) P; func _(x T) { x.m(42) }`,
+		{genericPkg + `q1; type T struct{}; func (T) m[P any](P) P { panic(0) }; func _(x T) { x.m(42) }`,
 			`x.m`,
 			[]string{`int`},
 			`func(int) int`,
 		},
-		{genericPkg + `q2; type T struct{}; func (T) m[P any](...P) P; func _(x T) { x.m(42) }`,
+		{genericPkg + `q2; type T struct{}; func (T) m[P any](...P) P { panic(0) }; func _(x T) { x.m(42) }`,
 			`x.m`,
 			[]string{`int`},
 			`func(...int) int`,
 		},
-		{genericPkg + `q3; type T struct{}; func (T) m[A, B, C any](A, *B, []C); func _(x T) { x.m(1.2, new(string), []byte{}) }`,
+		{genericPkg + `q3; type T struct{}; func (T) m[A, B, C any](A, *B, []C) {}; func _(x T) { x.m(1.2, new(string), []byte{}) }`,
 			`x.m`,
 			[]string{`float64`, `string`, `byte`},
 			`func(float64, *string, []byte)`,
 		},
-		{genericPkg + `q4; type T struct{}; func (T) m[A, B any](A, *B, ...[]B); func _(x T) { x.m(1.2, new(byte)) }`,
+		{genericPkg + `q4; type T struct{}; func (T) m[A, B any](A, *B, ...[]B) {}; func _(x T) { x.m(1.2, new(byte)) }`,
 			`x.m`,
 			[]string{`float64`, `byte`},
 			`func(float64, *byte, ...[]byte)`,
 		},
 
-		{genericPkg + `r0; type T[P any] struct{}; func (_ T[P]) m[Q any](Q); func _[P any](x T[P]) { x.m(42) }`,
+		{genericPkg + `r0; type T[P any] struct{}; func (_ T[P]) m[Q any](Q) {}; func _[P any](x T[P]) { x.m(42) }`,
 			`x.m`,
 			[]string{`int`},
 			`func(int)`,
@@ -455,38 +454,38 @@ func TestInferredInfo(t *testing.T) {
 		// 	`func(float64)`,
 		// },
 
-		{genericPkg + `s1; func f[T any, P interface{type *T}](x T); func _(x string) { f(x) }`,
+		{genericPkg + `s1; func f[T any, P interface{~*T}](x T) {}; func _(x string) { f(x) }`,
 			`f`,
 			[]string{`string`, `*string`},
 			`func(x string)`,
 		},
-		{genericPkg + `s2; func f[T any, P interface{type *T}](x []T); func _(x []int) { f(x) }`,
+		{genericPkg + `s2; func f[T any, P interface{~*T}](x []T) {}; func _(x []int) { f(x) }`,
 			`f`,
 			[]string{`int`, `*int`},
 			`func(x []int)`,
 		},
-		{genericPkg + `s3; type C[T any] interface{type chan<- T}; func f[T any, P C[T]](x []T); func _(x []int) { f(x) }`,
+		{genericPkg + `s3; type C[T any] interface{~chan<- T}; func f[T any, P C[T]](x []T) {}; func _(x []int) { f(x) }`,
 			`f`,
 			[]string{`int`, `chan<- int`},
 			`func(x []int)`,
 		},
-		{genericPkg + `s4; type C[T any] interface{type chan<- T}; func f[T any, P C[T], Q C[[]*P]](x []T); func _(x []int) { f(x) }`,
+		{genericPkg + `s4; type C[T any] interface{~chan<- T}; func f[T any, P C[T], Q C[[]*P]](x []T) {}; func _(x []int) { f(x) }`,
 			`f`,
 			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
 			`func(x []int)`,
 		},
 
-		{genericPkg + `t1; func f[T any, P interface{type *T}]() T; func _() { _ = f[string] }`,
+		{genericPkg + `t1; func f[T any, P interface{~*T}]() T { panic(0) }; func _() { _ = f[string] }`,
 			`f`,
 			[]string{`string`, `*string`},
 			`func() string`,
 		},
-		{genericPkg + `t2; type C[T any] interface{type chan<- T}; func f[T any, P C[T]]() []T; func _() { _ = f[int] }`,
+		{genericPkg + `t2; type C[T any] interface{~chan<- T}; func f[T any, P C[T]]() []T { return nil }; func _() { _ = f[int] }`,
 			`f`,
 			[]string{`int`, `chan<- int`},
 			`func() []int`,
 		},
-		{genericPkg + `t3; type C[T any] interface{type chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T; func _() { _ = f[int] }`,
+		{genericPkg + `t3; type C[T any] interface{~chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T { return nil }; func _() { _ = f[int] }`,
 			`f`,
 			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
 			`func() []int`,
@@ -515,7 +514,7 @@ func TestInferredInfo(t *testing.T) {
 				panic(fmt.Sprintf("unexpected call expression type %T", call))
 			}
 			if syntax.String(fun) == test.fun {
-				targs = inf.Targs
+				targs = inf.TArgs
 				sig = inf.Sig
 				break
 			}
@@ -1568,6 +1567,14 @@ func F(){
 	}
 }
 
+var nopos syntax.Pos
+
+// newDefined creates a new defined type named T with the given underlying type.
+func newDefined(underlying Type) *Named {
+	tname := NewTypeName(nopos, nil, "T", nil)
+	return NewNamed(tname, underlying, nil)
+}
+
 func TestConvertibleTo(t *testing.T) {
 	for _, test := range []struct {
 		v, t Type
@@ -1847,3 +1854,53 @@ func f(x T) T { return foo.F(x) }
 		}
 	}
 }
+
+func TestInstantiate(t *testing.T) {
+	// eventually we like more tests but this is a start
+	const src = genericPkg + "p; type T[P any] *T[P]"
+	pkg, err := pkgFor(".", src, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// type T should have one type parameter
+	T := pkg.Scope().Lookup("T").Type().(*Named)
+	if n := T.TParams().Len(); n != 1 {
+		t.Fatalf("expected 1 type parameter; found %d", n)
+	}
+
+	// instantiation should succeed (no endless recursion)
+	// even with a nil *Checker
+	var check *Checker
+	res := check.Instantiate(nopos, T, []Type{Typ[Int]}, nil, false)
+
+	// instantiated type should point to itself
+	if p := res.Underlying().(*Pointer).Elem(); p != res {
+		t.Fatalf("unexpected result type: %s points to %s", res, p)
+	}
+}
+
+func TestInstanceIdentity(t *testing.T) {
+	imports := make(testImporter)
+	conf := Config{Importer: imports}
+	makePkg := func(src string) {
+		f, err := parseSrc("", src)
+		if err != nil {
+			t.Fatal(err)
+		}
+		name := f.PkgName.Value
+		pkg, err := conf.Check(name, []*syntax.File{f}, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		imports[name] = pkg
+	}
+	makePkg(genericPkg + `lib; type T[P any] struct{}`)
+	makePkg(genericPkg + `a; import "generic_lib"; var A generic_lib.T[int]`)
+	makePkg(genericPkg + `b; import "generic_lib"; var B generic_lib.T[int]`)
+	a := imports["generic_a"].Scope().Lookup("A")
+	b := imports["generic_b"].Scope().Lookup("B")
+	if !Identical(a.Type(), b.Type()) {
+		t.Errorf("mismatching types: a.A: %s, b.B: %s", a.Type(), b.Type())
+	}
+}
diff --git a/src/cmd/compile/internal/types2/array.go b/src/cmd/compile/internal/types2/array.go
new file mode 100644
index 00000000000..502d49bc257
--- /dev/null
+++ b/src/cmd/compile/internal/types2/array.go
@@ -0,0 +1,25 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// An Array represents an array type.
+type Array struct {
+	len  int64
+	elem Type
+}
+
+// NewArray returns a new array type for the given element type and length.
+// A negative length indicates an unknown length.
+func NewArray(elem Type, len int64) *Array { return &Array{len: len, elem: elem} }
+
+// Len returns the length of array a.
+// A negative result indicates an unknown length.
+func (a *Array) Len() int64 { return a.len }
+
+// Elem returns element type of array a.
+func (a *Array) Elem() Type { return a.elem }
+
+func (a *Array) Underlying() Type { return a }
+func (a *Array) String() string   { return TypeString(a, nil) }
diff --git a/src/cmd/compile/internal/types2/assignments.go b/src/cmd/compile/internal/types2/assignments.go
index 583118c8b23..6184fc2ea50 100644
--- a/src/cmd/compile/internal/types2/assignments.go
+++ b/src/cmd/compile/internal/types2/assignments.go
@@ -68,7 +68,7 @@ func (check *Checker) assignment(x *operand, T Type, context string) {
 	// x.typ is typed
 
 	// A generic (non-instantiated) function value cannot be assigned to a variable.
-	if sig := asSignature(x.typ); sig != nil && len(sig.tparams) > 0 {
+	if sig := asSignature(x.typ); sig != nil && sig.TParams().Len() > 0 {
 		check.errorf(x, "cannot use generic function %s without instantiation in %s", x, context)
 	}
 
diff --git a/src/cmd/compile/internal/types2/basic.go b/src/cmd/compile/internal/types2/basic.go
new file mode 100644
index 00000000000..2fd973cafbc
--- /dev/null
+++ b/src/cmd/compile/internal/types2/basic.go
@@ -0,0 +1,82 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// BasicKind describes the kind of basic type.
+type BasicKind int
+
+const (
+	Invalid BasicKind = iota // type is invalid
+
+	// predeclared types
+	Bool
+	Int
+	Int8
+	Int16
+	Int32
+	Int64
+	Uint
+	Uint8
+	Uint16
+	Uint32
+	Uint64
+	Uintptr
+	Float32
+	Float64
+	Complex64
+	Complex128
+	String
+	UnsafePointer
+
+	// types for untyped values
+	UntypedBool
+	UntypedInt
+	UntypedRune
+	UntypedFloat
+	UntypedComplex
+	UntypedString
+	UntypedNil
+
+	// aliases
+	Byte = Uint8
+	Rune = Int32
+)
+
+// BasicInfo is a set of flags describing properties of a basic type.
+type BasicInfo int
+
+// Properties of basic types.
+const (
+	IsBoolean BasicInfo = 1 << iota
+	IsInteger
+	IsUnsigned
+	IsFloat
+	IsComplex
+	IsString
+	IsUntyped
+
+	IsOrdered   = IsInteger | IsFloat | IsString
+	IsNumeric   = IsInteger | IsFloat | IsComplex
+	IsConstType = IsBoolean | IsNumeric | IsString
+)
+
+// A Basic represents a basic type.
+type Basic struct {
+	kind BasicKind
+	info BasicInfo
+	name string
+}
+
+// Kind returns the kind of basic type b.
+func (b *Basic) Kind() BasicKind { return b.kind }
+
+// Info returns information about properties of basic type b.
+func (b *Basic) Info() BasicInfo { return b.info }
+
+// Name returns the name of basic type b.
+func (b *Basic) Name() string { return b.name }
+
+func (b *Basic) Underlying() Type { return b }
+func (b *Basic) String() string   { return TypeString(b, nil) }
diff --git a/src/cmd/compile/internal/types2/builtins.go b/src/cmd/compile/internal/types2/builtins.go
index b9e178dd576..da2dcf54aa3 100644
--- a/src/cmd/compile/internal/types2/builtins.go
+++ b/src/cmd/compile/internal/types2/builtins.go
@@ -46,7 +46,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 	default:
 		// make argument getter
 		xlist, _ := check.exprList(call.ArgList, false)
-		arg = func(x *operand, i int) { *x = *xlist[i]; x.typ = expand(x.typ) }
+		arg = func(x *operand, i int) { *x = *xlist[i] }
 		nargs = len(xlist)
 		// evaluate first argument, if present
 		if nargs > 0 {
@@ -144,7 +144,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 		mode := invalid
 		var typ Type
 		var val constant.Value
-		switch typ = implicitArrayDeref(optype(x.typ)); t := typ.(type) {
+		switch typ = arrayPtrDeref(under(x.typ)); t := typ.(type) {
 		case *Basic:
 			if isString(t) && id == _Len {
 				if x.mode == constant_ {
@@ -178,9 +178,9 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 				mode = value
 			}
 
-		case *Sum:
-			if t.is(func(t Type) bool {
-				switch t := under(t).(type) {
+		case *TypeParam:
+			if t.underIs(func(t Type) bool {
+				switch t := arrayPtrDeref(t).(type) {
 				case *Basic:
 					if isString(t) && id == _Len {
 						return true
@@ -212,19 +212,23 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 
 	case _Close:
 		// close(c)
-		c := asChan(x.typ)
-		if c == nil {
-			check.errorf(x, invalidArg+"%s is not a channel", x)
+		if !underIs(x.typ, func(u Type) bool {
+			uch, _ := u.(*Chan)
+			if uch == nil {
+				check.errorf(x, invalidOp+"cannot close non-channel %s", x)
+				return false
+			}
+			if uch.dir == RecvOnly {
+				check.errorf(x, invalidOp+"cannot close receive-only channel %s", x)
+				return false
+			}
+			return true
+		}) {
 			return
 		}
-		if c.dir == RecvOnly {
-			check.errorf(x, invalidArg+"%s must not be a receive-only channel", x)
-			return
-		}
-
 		x.mode = novalue
 		if check.Types != nil {
-			check.recordBuiltinType(call.Fun, makeSig(nil, c))
+			check.recordBuiltinType(call.Fun, makeSig(nil, x.typ))
 		}
 
 	case _Complex:
@@ -281,7 +285,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 		}
 
 		// both argument types must be identical
-		if !check.identical(x.typ, y.typ) {
+		if !Identical(x.typ, y.typ) {
 			check.errorf(x, invalidOp+"%v (mismatched types %s and %s)", call, x.typ, y.typ)
 			return
 		}
@@ -332,13 +336,15 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 			return
 		}
 		var src Type
-		switch t := optype(y.typ).(type) {
+		switch t := under(y.typ).(type) {
 		case *Basic:
 			if isString(y.typ) {
 				src = universeByte
 			}
 		case *Slice:
 			src = t.elem
+		case *TypeParam:
+			check.error(x, "copy on generic operands not yet implemented")
 		}
 
 		if dst == nil || src == nil {
@@ -346,7 +352,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 			return
 		}
 
-		if !check.identical(dst, src) {
+		if !Identical(dst, src) {
 			check.errorf(x, invalidArg+"arguments to copy %s and %s have different element types %s and %s", x, &y, dst, src)
 			return
 		}
@@ -358,25 +364,40 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 		x.typ = Typ[Int]
 
 	case _Delete:
-		// delete(m, k)
-		m := asMap(x.typ)
-		if m == nil {
-			check.errorf(x, invalidArg+"%s is not a map", x)
+		// delete(map_, key)
+		// map_ must be a map type or a type parameter describing map types.
+		// The key cannot be a type parameter for now.
+		map_ := x.typ
+		var key Type
+		if !underIs(map_, func(u Type) bool {
+			map_, _ := u.(*Map)
+			if map_ == nil {
+				check.errorf(x, invalidArg+"%s is not a map", x)
+				return false
+			}
+			if key != nil && !Identical(map_.key, key) {
+				check.errorf(x, invalidArg+"maps of %s must have identical key types", x)
+				return false
+			}
+			key = map_.key
+			return true
+		}) {
 			return
 		}
+
 		arg(x, 1) // k
 		if x.mode == invalid {
 			return
 		}
 
-		check.assignment(x, m.key, "argument to delete")
+		check.assignment(x, key, "argument to delete")
 		if x.mode == invalid {
 			return
 		}
 
 		x.mode = novalue
 		if check.Types != nil {
-			check.recordBuiltinType(call.Fun, makeSig(nil, m, m.key))
+			check.recordBuiltinType(call.Fun, makeSig(nil, map_, key))
 		}
 
 	case _Imag, _Real:
@@ -451,39 +472,21 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 			return
 		}
 
-		min, max := -1, 10
-		var valid func(t Type) bool
-		valid = func(t Type) bool {
-			var m int
-			switch t := optype(t).(type) {
-			case *Slice:
-				m = 2
-			case *Map, *Chan:
-				m = 1
-			case *Sum:
-				return t.is(valid)
-			default:
-				return false
-			}
-			if m > min {
-				min = m
-			}
-			if m+1 < max {
-				max = m + 1
-			}
-			return true
-		}
-
-		if !valid(T) {
+		var min int // minimum number of arguments
+		switch optype(T).(type) {
+		case *Slice:
+			min = 2
+		case *Map, *Chan:
+			min = 1
+		case *top:
+			check.errorf(arg0, invalidArg+"cannot make %s; type parameter has no structural type", arg0)
+			return
+		default:
 			check.errorf(arg0, invalidArg+"cannot make %s; type must be slice, map, or channel", arg0)
 			return
 		}
-		if nargs < min || max < nargs {
-			if min == max {
-				check.errorf(call, "%v expects %d arguments; found %d", call, min, nargs)
-			} else {
-				check.errorf(call, "%v expects %d or %d arguments; found %d", call, min, max, nargs)
-			}
+		if nargs < min || min+1 < nargs {
+			check.errorf(call, invalidOp+"%v expects %d or %d arguments; found %d", call, min, min+1, nargs)
 			return
 		}
 
@@ -579,6 +582,11 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 
 	case _Add:
 		// unsafe.Add(ptr unsafe.Pointer, len IntegerType) unsafe.Pointer
+		if !check.allowVersion(check.pkg, 1, 17) {
+			check.error(call.Fun, "unsafe.Add requires go1.17 or later")
+			return
+		}
+
 		check.assignment(x, Typ[UnsafePointer], "argument to unsafe.Add")
 		if x.mode == invalid {
 			return
@@ -598,19 +606,22 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 
 	case _Alignof:
 		// unsafe.Alignof(x T) uintptr
-		if asTypeParam(x.typ) != nil {
-			check.errorf(call, invalidOp+"unsafe.Alignof undefined for %s", x)
-			return
-		}
 		check.assignment(x, nil, "argument to unsafe.Alignof")
 		if x.mode == invalid {
 			return
 		}
 
-		x.mode = constant_
-		x.val = constant.MakeInt64(check.conf.alignof(x.typ))
+		if hasVarSize(x.typ) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], x.typ))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.alignof(x.typ))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Offsetof:
 		// unsafe.Offsetof(x T) uintptr, where x must be a selector
@@ -630,7 +641,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 
 		base := derefStructPtr(x.typ)
 		sel := selx.Sel.Value
-		obj, index, indirect := check.lookupFieldOrMethod(base, false, check.pkg, sel)
+		obj, index, indirect := LookupFieldOrMethod(base, false, check.pkg, sel)
 		switch obj.(type) {
 		case nil:
 			check.errorf(x, invalidArg+"%s has no single field %s", base, sel)
@@ -648,33 +659,51 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 			return
 		}
 
-		// TODO(gri) Should we pass x.typ instead of base (and indirect report if derefStructPtr indirected)?
+		// TODO(gri) Should we pass x.typ instead of base (and have indirect report if derefStructPtr indirected)?
 		check.recordSelection(selx, FieldVal, base, obj, index, false)
 
-		offs := check.conf.offsetof(base, index)
-		x.mode = constant_
-		x.val = constant.MakeInt64(offs)
+		// The field offset is considered a variable even if the field is declared before
+		// the part of the struct which is variable-sized. This makes both the rules
+		// simpler and also permits (or at least doesn't prevent) a compiler from re-
+		// arranging struct fields if it wanted to.
+		if hasVarSize(base) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], obj.Type()))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.offsetof(base, index))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Sizeof:
 		// unsafe.Sizeof(x T) uintptr
-		if asTypeParam(x.typ) != nil {
-			check.errorf(call, invalidOp+"unsafe.Sizeof undefined for %s", x)
-			return
-		}
 		check.assignment(x, nil, "argument to unsafe.Sizeof")
 		if x.mode == invalid {
 			return
 		}
 
-		x.mode = constant_
-		x.val = constant.MakeInt64(check.conf.sizeof(x.typ))
+		if hasVarSize(x.typ) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], x.typ))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.sizeof(x.typ))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Slice:
 		// unsafe.Slice(ptr *T, len IntegerType) []T
+		if !check.allowVersion(check.pkg, 1, 17) {
+			check.error(call.Fun, "unsafe.Slice requires go1.17 or later")
+			return
+		}
+
 		typ := asPointer(x.typ)
 		if typ == nil {
 			check.errorf(x, invalidArg+"%s is not a pointer", x)
@@ -738,6 +767,25 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 	return true
 }
 
+// hasVarSize reports if the size of type t is variable due to type parameters.
+func hasVarSize(t Type) bool {
+	switch t := under(t).(type) {
+	case *Array:
+		return hasVarSize(t.elem)
+	case *Struct:
+		for _, f := range t.fields {
+			if hasVarSize(f.typ) {
+				return true
+			}
+		}
+	case *TypeParam:
+		return true
+	case *Named, *Union, *top:
+		unreachable()
+	}
+	return false
+}
+
 // applyTypeFunc applies f to x. If x is a type parameter,
 // the result is a type parameter constrained by an new
 // interface bound. The type bounds for that interface
@@ -749,10 +797,10 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
 	if tp := asTypeParam(x); tp != nil {
 		// Test if t satisfies the requirements for the argument
 		// type and collect possible result types at the same time.
-		var rtypes []Type
-		if !tp.Bound().is(func(x Type) bool {
-			if r := f(x); r != nil {
-				rtypes = append(rtypes, r)
+		var terms []*Term
+		if !tp.iface().typeSet().is(func(t *term) bool {
+			if r := f(t.typ); r != nil {
+				terms = append(terms, NewTerm(t.tilde, r))
 				return true
 			}
 			return false
@@ -765,11 +813,12 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
 		//           uses of real() where the result is used to
 		//           define type and initialize a variable?
 
-		// construct a suitable new type parameter
-		tpar := NewTypeName(nopos, nil /* = Universe pkg */, "", nil)
-		ptyp := check.NewTypeParam(tpar, 0, &emptyInterface) // assigns type to tpar as a side-effect
-		tsum := NewSum(rtypes)
-		ptyp.bound = &Interface{types: tsum, allMethods: markComplete, allTypes: tsum}
+		// Construct a suitable new type parameter for the sum type. The
+		// type param is placed in the current package so export/import
+		// works as expected.
+		tpar := NewTypeName(nopos, check.pkg, "", nil)
+		ptyp := check.NewTypeParam(tpar, NewInterfaceType(nil, []Type{NewUnion(terms)})) // assigns type to tpar as a side-effect
+		ptyp.index = tp.index
 
 		return ptyp
 	}
@@ -793,10 +842,9 @@ func makeSig(res Type, args ...Type) *Signature {
 	return &Signature{params: params, results: result}
 }
 
-// implicitArrayDeref returns A if typ is of the form *A and A is an array;
+// arrayPtrDeref returns A if typ is of the form *A and A is an array;
 // otherwise it returns typ.
-//
-func implicitArrayDeref(typ Type) Type {
+func arrayPtrDeref(typ Type) Type {
 	if p, ok := typ.(*Pointer); ok {
 		if a := asArray(p.base); a != nil {
 			return a
diff --git a/src/cmd/compile/internal/types2/builtins_test.go b/src/cmd/compile/internal/types2/builtins_test.go
index 82c786b86ea..52dbba1cb98 100644
--- a/src/cmd/compile/internal/types2/builtins_test.go
+++ b/src/cmd/compile/internal/types2/builtins_test.go
@@ -7,6 +7,7 @@ package types2_test
 import (
 	"cmd/compile/internal/syntax"
 	"fmt"
+	"strings"
 	"testing"
 
 	. "cmd/compile/internal/types2"
@@ -111,12 +112,15 @@ var builtinCalls = []struct {
 
 	{"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`},                 // constant
 	{"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
+	{"Alignof", `var x P; _ = unsafe.Alignof(x)`, `func(p.P₁) uintptr`},
 
 	{"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`},           // constant
 	{"Offsetof", `var x struct{_ int; f bool}; _ = unsafe.Offsetof((&x).f)`, `invalid type`}, // constant
+	{"Offsetof", `var x struct{_ int; f P}; _ = unsafe.Offsetof((&x).f)`, `func(p.P₁) uintptr`},
 
 	{"Sizeof", `_ = unsafe.Sizeof(0)`, `invalid type`},                 // constant
 	{"Sizeof", `var x struct{}; _ = unsafe.Sizeof(x)`, `invalid type`}, // constant
+	{"Sizeof", `var x P; _ = unsafe.Sizeof(x)`, `func(p.P₁) uintptr`},
 
 	{"Slice", `var p *int; _ = unsafe.Slice(p, 1)`, `func(*int, int) []int`},
 	{"Slice", `var p *byte; var n uintptr; _ = unsafe.Slice(p, n)`, `func(*byte, uintptr) []byte`},
@@ -149,9 +153,14 @@ func TestBuiltinSignatures(t *testing.T) {
 	}
 }
 
+func parseGenericSrc(path, src string) (*syntax.File, error) {
+	errh := func(error) {} // dummy error handler so that parsing continues in presence of errors
+	return syntax.Parse(syntax.NewFileBase(path), strings.NewReader(src), errh, nil, syntax.AllowGenerics)
+}
+
 func testBuiltinSignature(t *testing.T, name, src0, want string) {
-	src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _() { %s }`, src0)
-	f, err := parseSrc("", src)
+	src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _[P any]() { %s }`, src0)
+	f, err := parseGenericSrc("", src)
 	if err != nil {
 		t.Errorf("%s: %s", src0, err)
 		return
diff --git a/src/cmd/compile/internal/types2/call.go b/src/cmd/compile/internal/types2/call.go
index 6d149340b28..94bcc4870bb 100644
--- a/src/cmd/compile/internal/types2/call.go
+++ b/src/cmd/compile/internal/types2/call.go
@@ -26,7 +26,7 @@ func (check *Checker) funcInst(x *operand, inst *syntax.IndexExpr) {
 
 	// check number of type arguments (got) vs number of type parameters (want)
 	sig := x.typ.(*Signature)
-	got, want := len(targs), len(sig.tparams)
+	got, want := len(targs), sig.TParams().Len()
 	if !useConstraintTypeInference && got != want || got > want {
 		check.errorf(xlist[got-1], "got %d type arguments but want %d", got, want)
 		x.mode = invalid
@@ -37,7 +37,7 @@ func (check *Checker) funcInst(x *operand, inst *syntax.IndexExpr) {
 	// if we don't have enough type arguments, try type inference
 	inferred := false
 	if got < want {
-		targs = check.infer(inst.Pos(), sig.tparams, targs, nil, nil, true)
+		targs = check.infer(inst.Pos(), sig.TParams().list(), targs, nil, nil, true)
 		if targs == nil {
 			// error was already reported
 			x.mode = invalid
@@ -56,8 +56,8 @@ func (check *Checker) funcInst(x *operand, inst *syntax.IndexExpr) {
 	}
 
 	// instantiate function signature
-	res := check.instantiate(x.Pos(), sig, targs, poslist).(*Signature)
-	assert(res.tparams == nil) // signature is not generic anymore
+	res := check.Instantiate(x.Pos(), sig, targs, poslist, true).(*Signature)
+	assert(res.TParams().Len() == 0) // signature is not generic anymore
 	if inferred {
 		check.recordInferred(inst, targs, res)
 	}
@@ -99,7 +99,6 @@ func (check *Checker) callExpr(x *operand, call *syntax.CallExpr) exprKind {
 			check.expr(x, call.ArgList[0])
 			if x.mode != invalid {
 				if t := asInterface(T); t != nil {
-					check.completeInterface(nopos, t)
 					if t.IsConstraint() {
 						check.errorf(call, "cannot use interface %s in conversion (contains type list or is comparable)", T)
 						break
@@ -156,7 +155,7 @@ func (check *Checker) callExpr(x *operand, call *syntax.CallExpr) exprKind {
 		assert(len(targs) == len(xlist))
 
 		// check number of type arguments (got) vs number of type parameters (want)
-		got, want := len(targs), len(sig.tparams)
+		got, want := len(targs), sig.TParams().Len()
 		if got > want {
 			check.errorf(xlist[want], "got %d type arguments but want %d", got, want)
 			check.use(call.ArgList...)
@@ -190,7 +189,7 @@ func (check *Checker) callExpr(x *operand, call *syntax.CallExpr) exprKind {
 
 	// if type inference failed, a parametrized result must be invalidated
 	// (operands cannot have a parametrized type)
-	if x.mode == value && len(sig.tparams) > 0 && isParameterized(sig.tparams, x.typ) {
+	if x.mode == value && sig.TParams().Len() > 0 && isParameterized(sig.TParams().list(), x.typ) {
 		x.mode = invalid
 	}
 
@@ -318,24 +317,24 @@ func (check *Checker) arguments(call *syntax.CallExpr, sig *Signature, targs []T
 	}
 
 	// infer type arguments and instantiate signature if necessary
-	if len(sig.tparams) > 0 {
+	if sig.TParams().Len() > 0 {
 		// TODO(gri) provide position information for targs so we can feed
 		//           it to the instantiate call for better error reporting
-		targs = check.infer(call.Pos(), sig.tparams, targs, sigParams, args, true)
+		targs := check.infer(call.Pos(), sig.TParams().list(), targs, sigParams, args, true)
 		if targs == nil {
 			return // error already reported
 		}
 
 		// compute result signature
-		rsig = check.instantiate(call.Pos(), sig, targs, nil).(*Signature)
-		assert(rsig.tparams == nil) // signature is not generic anymore
+		rsig = check.Instantiate(call.Pos(), sig, targs, nil, true).(*Signature)
+		assert(rsig.TParams().Len() == 0) // signature is not generic anymore
 		check.recordInferred(call, targs, rsig)
 
 		// Optimization: Only if the parameter list was adjusted do we
 		// need to compute it from the adjusted list; otherwise we can
 		// simply use the result signature's parameter list.
 		if adjusted {
-			sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(sig.tparams, targs)).(*Tuple)
+			sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(sig.TParams().list(), targs), nil).(*Tuple)
 		} else {
 			sigParams = rsig.params
 		}
@@ -468,7 +467,7 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 
 	check.instantiatedOperand(x)
 
-	obj, index, indirect = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel)
+	obj, index, indirect = LookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel)
 	if obj == nil {
 		switch {
 		case index != nil:
@@ -480,11 +479,10 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 			var why string
 			if tpar := asTypeParam(x.typ); tpar != nil {
 				// Type parameter bounds don't specify fields, so don't mention "field".
-				switch obj := tpar.Bound().obj.(type) {
-				case nil:
+				if tname := tpar.iface().obj; tname != nil {
+					why = check.sprintf("interface %s has no method %s", tname.name, sel)
+				} else {
 					why = check.sprintf("type bound for %s has no method %s", x.typ, sel)
-				case *TypeName:
-					why = check.sprintf("interface %s has no method %s", obj.name, sel)
 				}
 			} else {
 				why = check.sprintf("type %s has no field or method %s", x.typ, sel)
@@ -498,7 +496,7 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 				} else {
 					changeCase = string(unicode.ToUpper(r)) + sel[1:]
 				}
-				if obj, _, _ = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, changeCase); obj != nil {
+				if obj, _, _ = LookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, changeCase); obj != nil {
 					why += ", but does have " + changeCase
 				}
 			}
@@ -518,7 +516,7 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 		// the signature accordingly.
 		// TODO(gri) factor this code out
 		sig := m.typ.(*Signature)
-		if len(sig.rparams) > 0 {
+		if sig.RParams().Len() > 0 {
 			// For inference to work, we must use the receiver type
 			// matching the receiver in the actual method declaration.
 			// If the method is embedded, the matching receiver is the
@@ -547,7 +545,7 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 			// the receiver type arguments here, the receiver must be be otherwise invalid
 			// and an error has been reported elsewhere.
 			arg := operand{mode: variable, expr: x.expr, typ: recv}
-			targs := check.infer(m.pos, sig.rparams, nil, NewTuple(sig.recv), []*operand{&arg}, false /* no error reporting */)
+			targs := check.infer(m.pos, sig.RParams().list(), nil, NewTuple(sig.recv), []*operand{&arg}, false /* no error reporting */)
 			//check.dump("### inferred targs = %s", targs)
 			if targs == nil {
 				// We may reach here if there were other errors (see issue #40056).
@@ -557,7 +555,7 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 			// (If we modify m, some tests will fail; possibly because the m is in use.)
 			// TODO(gri) investigate and provide a correct explanation here
 			copy := *m
-			copy.typ = check.subst(e.Pos(), m.typ, makeSubstMap(sig.rparams, targs))
+			copy.typ = check.subst(e.Pos(), m.typ, makeSubstMap(sig.RParams().list(), targs), nil)
 			obj = ©
 		}
 		// TODO(gri) we also need to do substitution for parameterized interface methods
@@ -576,17 +574,37 @@ func (check *Checker) selector(x *operand, e *syntax.SelectorExpr) {
 
 		check.recordSelection(e, MethodExpr, x.typ, m, index, indirect)
 
-		// the receiver type becomes the type of the first function
-		// argument of the method expression's function type
-		var params []*Var
 		sig := m.typ.(*Signature)
+		if sig.recv == nil {
+			check.error(e, "illegal cycle in method declaration")
+			goto Error
+		}
+
+		// The receiver type becomes the type of the first function
+		// argument of the method expression's function type.
+		var params []*Var
 		if sig.params != nil {
 			params = sig.params.vars
 		}
+		// Be consistent about named/unnamed parameters. This is not needed
+		// for type-checking, but the newly constructed signature may appear
+		// in an error message and then have mixed named/unnamed parameters.
+		// (An alternative would be to not print parameter names in errors,
+		// but it's useful to see them; this is cheap and method expressions
+		// are rare.)
+		name := ""
+		if len(params) > 0 && params[0].name != "" {
+			// name needed
+			name = sig.recv.name
+			if name == "" {
+				name = "_"
+			}
+		}
+		params = append([]*Var{NewVar(sig.recv.pos, sig.recv.pkg, name, x.typ)}, params...)
 		x.mode = value
 		x.typ = &Signature{
 			tparams:  sig.tparams,
-			params:   NewTuple(append([]*Var{NewVar(nopos, check.pkg, "_", x.typ)}, params...)...),
+			params:   NewTuple(params...),
 			results:  sig.results,
 			variadic: sig.variadic,
 		}
diff --git a/src/cmd/compile/internal/types2/chan.go b/src/cmd/compile/internal/types2/chan.go
new file mode 100644
index 00000000000..77650dfb09d
--- /dev/null
+++ b/src/cmd/compile/internal/types2/chan.go
@@ -0,0 +1,35 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A Chan represents a channel type.
+type Chan struct {
+	dir  ChanDir
+	elem Type
+}
+
+// A ChanDir value indicates a channel direction.
+type ChanDir int
+
+// The direction of a channel is indicated by one of these constants.
+const (
+	SendRecv ChanDir = iota
+	SendOnly
+	RecvOnly
+)
+
+// NewChan returns a new channel type for the given direction and element type.
+func NewChan(dir ChanDir, elem Type) *Chan {
+	return &Chan{dir: dir, elem: elem}
+}
+
+// Dir returns the direction of channel c.
+func (c *Chan) Dir() ChanDir { return c.dir }
+
+// Elem returns the element type of channel c.
+func (c *Chan) Elem() Type { return c.elem }
+
+func (c *Chan) Underlying() Type { return c }
+func (c *Chan) String() string   { return TypeString(c, nil) }
diff --git a/src/cmd/compile/internal/types2/check.go b/src/cmd/compile/internal/types2/check.go
index 8d6cd1edab9..6bc965c4978 100644
--- a/src/cmd/compile/internal/types2/check.go
+++ b/src/cmd/compile/internal/types2/check.go
@@ -71,7 +71,7 @@ type importKey struct {
 // A dotImportKey describes a dot-imported object in the given scope.
 type dotImportKey struct {
 	scope *Scope
-	obj   Object
+	name  string
 }
 
 // A Checker maintains the state of the type checker.
@@ -82,11 +82,11 @@ type Checker struct {
 	conf *Config
 	pkg  *Package
 	*Info
-	version version                     // accepted language version
-	objMap  map[Object]*declInfo        // maps package-level objects and (non-interface) methods to declaration info
-	impMap  map[importKey]*Package      // maps (import path, source directory) to (complete or fake) package
-	posMap  map[*Interface][]syntax.Pos // maps interface types to lists of embedded interface positions
-	typMap  map[string]*Named           // maps an instantiated named type hash to a *Named type
+	version version                // accepted language version
+	nextID  uint64                 // unique Id for type parameters (first valid Id is 1)
+	objMap  map[Object]*declInfo   // maps package-level objects and (non-interface) methods to declaration info
+	impMap  map[importKey]*Package // maps (import path, source directory) to (complete or fake) package
+	typMap  map[string]*Named      // maps an instantiated named type hash to a *Named type
 
 	// pkgPathMap maps package names to the set of distinct import paths we've
 	// seen for that name, anywhere in the import graph. It is used for
@@ -188,7 +188,6 @@ func NewChecker(conf *Config, pkg *Package, info *Info) *Checker {
 		version: version,
 		objMap:  make(map[Object]*declInfo),
 		impMap:  make(map[importKey]*Package),
-		posMap:  make(map[*Interface][]syntax.Pos),
 		typMap:  make(map[string]*Named),
 	}
 }
@@ -283,11 +282,6 @@ func (check *Checker) checkFiles(files []*syntax.File) (err error) {
 	print("== recordUntyped ==")
 	check.recordUntyped()
 
-	if check.Info != nil {
-		print("== sanitizeInfo ==")
-		sanitizeInfo(check.Info)
-	}
-
 	check.pkg.complete = true
 
 	// no longer needed - release memory
diff --git a/src/cmd/compile/internal/types2/conversions.go b/src/cmd/compile/internal/types2/conversions.go
index 30201e2b7f4..6c26a4c4468 100644
--- a/src/cmd/compile/internal/types2/conversions.go
+++ b/src/cmd/compile/internal/types2/conversions.go
@@ -93,7 +93,7 @@ func (x *operand) convertibleTo(check *Checker, T Type) bool {
 	V := x.typ
 	Vu := under(V)
 	Tu := under(T)
-	if check.identicalIgnoreTags(Vu, Tu) {
+	if IdenticalIgnoreTags(Vu, Tu) {
 		return true
 	}
 
@@ -101,7 +101,7 @@ func (x *operand) convertibleTo(check *Checker, T Type) bool {
 	// have identical underlying types if tags are ignored"
 	if V, ok := V.(*Pointer); ok {
 		if T, ok := T.(*Pointer); ok {
-			if check.identicalIgnoreTags(under(V.base), under(T.base)) {
+			if IdenticalIgnoreTags(under(V.base), under(T.base)) {
 				return true
 			}
 		}
@@ -142,7 +142,7 @@ func (x *operand) convertibleTo(check *Checker, T Type) bool {
 	if s := asSlice(V); s != nil {
 		if p := asPointer(T); p != nil {
 			if a := asArray(p.Elem()); a != nil {
-				if check.identical(s.Elem(), a.Elem()) {
+				if Identical(s.Elem(), a.Elem()) {
 					if check == nil || check.allowVersion(check.pkg, 1, 17) {
 						return true
 					}
diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index 1333e4c0eca..aa9710788ad 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -317,6 +317,8 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 		}
 
 	case *Named:
+		t.expand(check.typMap)
+
 		// don't touch the type if it is from a different package or the Universe scope
 		// (doing so would lead to a race condition - was issue #35049)
 		if t.obj.pkg != check.pkg {
@@ -338,7 +340,7 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 			// cycle detected
 			for i, tn := range path {
 				if t.obj.pkg != check.pkg {
-					panic("internal error: type cycle via package-external type")
+					panic("type cycle via package-external type")
 				}
 				if tn == t.obj {
 					check.cycleError(path[i:])
@@ -346,12 +348,9 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 					return t.info
 				}
 			}
-			panic("internal error: cycle start not found")
+			panic("cycle start not found")
 		}
 		return t.info
-
-	case *instance:
-		return check.validType(t.expand(), path)
 	}
 
 	return valid
@@ -515,75 +514,6 @@ func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init syntax.Expr) {
 	check.initVars(lhs, []syntax.Expr{init}, nopos)
 }
 
-// under returns the expanded underlying type of n0; possibly by following
-// forward chains of named types. If an underlying type is found, resolve
-// the chain by setting the underlying type for each defined type in the
-// chain before returning it. If no underlying type is found or a cycle
-// is detected, the result is Typ[Invalid]. If a cycle is detected and
-// n0.check != nil, the cycle is reported.
-func (n0 *Named) under() Type {
-	u := n0.underlying
-	if u == nil {
-		return Typ[Invalid]
-	}
-
-	// If the underlying type of a defined type is not a defined
-	// type, then that is the desired underlying type.
-	n := asNamed(u)
-	if n == nil {
-		return u // common case
-	}
-
-	// Otherwise, follow the forward chain.
-	seen := map[*Named]int{n0: 0}
-	path := []Object{n0.obj}
-	for {
-		u = n.underlying
-		if u == nil {
-			u = Typ[Invalid]
-			break
-		}
-		n1 := asNamed(u)
-		if n1 == nil {
-			break // end of chain
-		}
-
-		seen[n] = len(seen)
-		path = append(path, n.obj)
-		n = n1
-
-		if i, ok := seen[n]; ok {
-			// cycle
-			// TODO(gri) revert this to a method on Checker. Having a possibly
-			// nil Checker on Named and TypeParam is too subtle.
-			if n0.check != nil {
-				n0.check.cycleError(path[i:])
-			}
-			u = Typ[Invalid]
-			break
-		}
-	}
-
-	for n := range seen {
-		// We should never have to update the underlying type of an imported type;
-		// those underlying types should have been resolved during the import.
-		// Also, doing so would lead to a race condition (was issue #31749).
-		// Do this check always, not just in debug more (it's cheap).
-		if n0.check != nil && n.obj.pkg != n0.check.pkg {
-			panic("internal error: imported type with unresolved underlying type")
-		}
-		n.underlying = u
-	}
-
-	return u
-}
-
-func (n *Named) setUnderlying(typ Type) {
-	if n != nil {
-		n.underlying = typ
-	}
-}
-
 func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named) {
 	assert(obj.typ == nil)
 
@@ -599,8 +529,8 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named
 		alias = false
 	}
 
+	// alias declaration
 	if alias {
-		// type alias declaration
 		if !check.allowVersion(check.pkg, 1, 9) {
 			if check.conf.CompilerErrorMessages {
 				check.error(tdecl, "type aliases only supported as of -lang=go1.9")
@@ -611,111 +541,94 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named
 
 		obj.typ = Typ[Invalid]
 		obj.typ = check.anyType(tdecl.Type)
-
-	} else {
-		// defined type declaration
-
-		named := check.newNamed(obj, nil, nil, nil, nil)
-		def.setUnderlying(named)
-
-		if tdecl.TParamList != nil {
-			check.openScope(tdecl, "type parameters")
-			defer check.closeScope()
-			named.tparams = check.collectTypeParams(tdecl.TParamList)
-		}
-
-		// determine underlying type of named
-		named.fromRHS = check.definedType(tdecl.Type, named)
-
-		// The underlying type of named may be itself a named type that is
-		// incomplete:
-		//
-		//	type (
-		//		A B
-		//		B *C
-		//		C A
-		//	)
-		//
-		// The type of C is the (named) type of A which is incomplete,
-		// and which has as its underlying type the named type B.
-		// Determine the (final, unnamed) underlying type by resolving
-		// any forward chain.
-		// TODO(gri) Investigate if we can just use named.fromRHS here
-		//           and rely on lazy computation of the underlying type.
-		named.underlying = under(named)
-	}
-
-}
-
-func (check *Checker) collectTypeParams(list []*syntax.Field) (tparams []*TypeName) {
-	// Type parameter lists should not be empty. The parser will
-	// complain but we still may get an incorrect AST: ignore it.
-	if len(list) == 0 {
 		return
 	}
 
-	// Declare type parameters up-front, with empty interface as type bound.
+	// type definition or generic type declaration
+	named := check.newNamed(obj, nil, nil, nil, nil)
+	def.setUnderlying(named)
+
+	if tdecl.TParamList != nil {
+		check.openScope(tdecl, "type parameters")
+		defer check.closeScope()
+		named.tparams = check.collectTypeParams(tdecl.TParamList)
+	}
+
+	// determine underlying type of named
+	named.fromRHS = check.definedType(tdecl.Type, named)
+	assert(named.fromRHS != nil)
+	// The underlying type of named may be itself a named type that is
+	// incomplete:
+	//
+	//	type (
+	//		A B
+	//		B *C
+	//		C A
+	//	)
+	//
+	// The type of C is the (named) type of A which is incomplete,
+	// and which has as its underlying type the named type B.
+	// Determine the (final, unnamed) underlying type by resolving
+	// any forward chain.
+	// TODO(gri) Investigate if we can just use named.fromRHS here
+	//           and rely on lazy computation of the underlying type.
+	named.underlying = under(named)
+
+	// If the RHS is a type parameter, it must be from this type declaration.
+	if tpar, _ := named.underlying.(*TypeParam); tpar != nil && tparamIndex(named.TParams().list(), tpar) < 0 {
+		check.errorf(tdecl.Type, "cannot use function type parameter %s as RHS in type declaration", tpar)
+		named.underlying = Typ[Invalid]
+	}
+}
+
+func (check *Checker) collectTypeParams(list []*syntax.Field) *TParamList {
+	tparams := make([]*TypeName, len(list))
+
+	// Declare type parameters up-front.
 	// The scope of type parameters starts at the beginning of the type parameter
-	// list (so we can have mutually recursive parameterized interfaces).
-	for _, f := range list {
-		tparams = check.declareTypeParam(tparams, f.Name)
+	// list (so we can have mutually recursive parameterized type bounds).
+	for i, f := range list {
+		tparams[i] = check.declareTypeParam(f.Name)
 	}
 
 	var bound Type
-	for i, j := 0, 0; i < len(list); i = j {
-		f := list[i]
-
-		// determine the range of type parameters list[i:j] with identical type bound
-		// (declared as in (type a, b, c B))
-		j = i + 1
-		for j < len(list) && list[j].Type == f.Type {
-			j++
-		}
-
-		// this should never be the case, but be careful
-		if f.Type == nil {
-			continue
-		}
-
-		// The predeclared identifier "any" is visible only as a constraint
-		// in a type parameter list. Look for it before general constraint
-		// resolution.
-		if tident, _ := unparen(f.Type).(*syntax.Name); tident != nil && tident.Value == "any" && check.lookup("any") == nil {
-			bound = universeAny
-		} else {
-			bound = check.typ(f.Type)
-		}
-
-		// type bound must be an interface
-		// TODO(gri) We should delay the interface check because
-		//           we may not have a complete interface yet:
-		//           type C(type T C) interface {}
-		//           (issue #39724).
-		if _, ok := under(bound).(*Interface); ok {
-			// set the type bounds
-			for i < j {
-				tparams[i].typ.(*TypeParam).bound = bound
-				i++
-			}
-		} else if bound != Typ[Invalid] {
-			check.errorf(f.Type, "%s is not an interface", bound)
+	for i, f := range list {
+		// Optimization: Re-use the previous type bound if it hasn't changed.
+		// This also preserves the grouped output of type parameter lists
+		// when printing type strings.
+		if i == 0 || f.Type != list[i-1].Type {
+			bound = check.boundType(f.Type)
 		}
+		tparams[i].typ.(*TypeParam).bound = bound
 	}
 
-	return
+	return bindTParams(tparams)
 }
 
-func (check *Checker) declareTypeParam(tparams []*TypeName, name *syntax.Name) []*TypeName {
+func (check *Checker) declareTypeParam(name *syntax.Name) *TypeName {
 	tpar := NewTypeName(name.Pos(), check.pkg, name.Value, nil)
-	check.NewTypeParam(tpar, len(tparams), &emptyInterface) // assigns type to tpar as a side-effect
+	check.NewTypeParam(tpar, nil)                           // assigns type to tpar as a side-effect
 	check.declare(check.scope, name, tpar, check.scope.pos) // TODO(gri) check scope position
-	tparams = append(tparams, tpar)
+	return tpar
+}
 
-	if check.conf.Trace {
-		check.trace(name.Pos(), "type param = %v", tparams[len(tparams)-1])
+// boundType type-checks the type expression e and returns its type, or Typ[Invalid].
+// The type must be an interface, including the predeclared type "any".
+func (check *Checker) boundType(e syntax.Expr) Type {
+	// The predeclared identifier "any" is visible only as a type bound in a type parameter list.
+	// If we allow "any" for general use, this if-statement can be removed (issue #33232).
+	if name, _ := unparen(e).(*syntax.Name); name != nil && name.Value == "any" && check.lookup("any") == universeAny {
+		return universeAny.Type()
 	}
 
-	return tparams
+	bound := check.typ(e)
+	check.later(func() {
+		u := under(bound)
+		if _, ok := u.(*Interface); !ok && u != Typ[Invalid] {
+			check.errorf(e, "%s is not an interface", bound)
+		}
+	})
+	return bound
 }
 
 func (check *Checker) collectMethods(obj *TypeName) {
@@ -737,7 +650,8 @@ func (check *Checker) collectMethods(obj *TypeName) {
 	// and field names must be distinct."
 	base := asNamed(obj.typ) // shouldn't fail but be conservative
 	if base != nil {
-		if t, _ := base.underlying.(*Struct); t != nil {
+		u := safeUnderlying(base) // base should be expanded, but use safeUnderlying to be conservative
+		if t, _ := u.(*Struct); t != nil {
 			for _, fld := range t.fields {
 				if fld.name != "_" {
 					assert(mset.insert(fld) == nil)
@@ -779,6 +693,7 @@ func (check *Checker) collectMethods(obj *TypeName) {
 		}
 
 		if base != nil {
+			base.load() // TODO(mdempsky): Probably unnecessary.
 			base.methods = append(base.methods, m)
 		}
 	}
@@ -805,6 +720,10 @@ func (check *Checker) funcDecl(obj *Func, decl *declInfo) {
 	check.funcType(sig, fdecl.Recv, fdecl.TParamList, fdecl.Type)
 	obj.color_ = saved
 
+	if len(fdecl.TParamList) > 0 && fdecl.Body == nil {
+		check.softErrorf(fdecl, "parameterized function is missing function body")
+	}
+
 	// function body must be type-checked after global declarations
 	// (functions implemented elsewhere have no body)
 	if !check.conf.IgnoreFuncBodies && fdecl.Body != nil {
diff --git a/src/cmd/compile/internal/types2/errorcalls_test.go b/src/cmd/compile/internal/types2/errorcalls_test.go
index 28bb33aaffd..80b05f9f0f0 100644
--- a/src/cmd/compile/internal/types2/errorcalls_test.go
+++ b/src/cmd/compile/internal/types2/errorcalls_test.go
@@ -18,7 +18,7 @@ func TestErrorCalls(t *testing.T) {
 	}
 
 	for _, file := range files {
-		syntax.Walk(file, func(n syntax.Node) bool {
+		syntax.Crawl(file, func(n syntax.Node) bool {
 			call, _ := n.(*syntax.CallExpr)
 			if call == nil {
 				return false
diff --git a/src/cmd/compile/internal/types2/errors.go b/src/cmd/compile/internal/types2/errors.go
index af4ecb2300a..a68273271b7 100644
--- a/src/cmd/compile/internal/types2/errors.go
+++ b/src/cmd/compile/internal/types2/errors.go
@@ -88,7 +88,7 @@ func sprintf(qf Qualifier, format string, args ...interface{}) string {
 		case nil:
 			arg = ""
 		case operand:
-			panic("internal error: should always pass *operand")
+			panic("got operand instead of *operand")
 		case *operand:
 			arg = operandString(a, qf)
 		case syntax.Pos:
@@ -111,7 +111,7 @@ func (check *Checker) qualifier(pkg *Package) string {
 		if check.pkgPathMap == nil {
 			check.pkgPathMap = make(map[string]map[string]bool)
 			check.seenPkgMap = make(map[*Package]bool)
-			check.markImports(pkg)
+			check.markImports(check.pkg)
 		}
 		// If the same package name was used by multiple packages, display the full path.
 		if len(check.pkgPathMap[pkg.name]) > 1 {
@@ -148,7 +148,7 @@ func (check *Checker) sprintf(format string, args ...interface{}) string {
 
 func (check *Checker) report(err *error_) {
 	if err.empty() {
-		panic("internal error: reporting no error")
+		panic("no error to report")
 	}
 	check.err(err.pos(), err.msg(check.qualifier), err.soft)
 }
diff --git a/src/cmd/compile/internal/types2/expr.go b/src/cmd/compile/internal/types2/expr.go
index 23b79656bb5..6d8b423714c 100644
--- a/src/cmd/compile/internal/types2/expr.go
+++ b/src/cmd/compile/internal/types2/expr.go
@@ -157,6 +157,14 @@ var op2str2 = [...]string{
 	syntax.Shl: "shift",
 }
 
+func underIs(typ Type, f func(Type) bool) bool {
+	u := under(typ)
+	if tpar, _ := u.(*TypeParam); tpar != nil {
+		return tpar.underIs(f)
+	}
+	return f(u)
+}
+
 func (check *Checker) unary(x *operand, e *syntax.Operation) {
 	check.expr(x, e.X)
 	if x.mode == invalid {
@@ -177,19 +185,29 @@ func (check *Checker) unary(x *operand, e *syntax.Operation) {
 		return
 
 	case syntax.Recv:
-		typ := asChan(x.typ)
-		if typ == nil {
-			check.errorf(x, invalidOp+"cannot receive from non-channel %s", x)
-			x.mode = invalid
-			return
-		}
-		if typ.dir == SendOnly {
-			check.errorf(x, invalidOp+"cannot receive from send-only channel %s", x)
+		var elem Type
+		if !underIs(x.typ, func(u Type) bool {
+			ch, _ := u.(*Chan)
+			if ch == nil {
+				check.errorf(x, invalidOp+"cannot receive from non-channel %s", x)
+				return false
+			}
+			if ch.dir == SendOnly {
+				check.errorf(x, invalidOp+"cannot receive from send-only channel %s", x)
+				return false
+			}
+			if elem != nil && !Identical(ch.elem, elem) {
+				check.errorf(x, invalidOp+"channels of %s must have the same element type", x)
+				return false
+			}
+			elem = ch.elem
+			return true
+		}) {
 			x.mode = invalid
 			return
 		}
 		x.mode = commaok
-		x.typ = typ.elem
+		x.typ = elem
 		check.hasCallOrRecv = true
 		return
 	}
@@ -643,7 +661,7 @@ func (check *Checker) updateExprVal(x syntax.Expr, val constant.Value) {
 func (check *Checker) convertUntyped(x *operand, target Type) {
 	newType, val, code := check.implicitTypeAndValue(x, target)
 	if code != 0 {
-		check.invalidConversion(code, x, target.Underlying())
+		check.invalidConversion(code, x, safeUnderlying(target))
 		x.mode = invalid
 		return
 	}
@@ -664,7 +682,6 @@ func (check *Checker) convertUntyped(x *operand, target Type) {
 // If x is a constant operand, the returned constant.Value will be the
 // representation of x in this context.
 func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, constant.Value, errorCode) {
-	target = expand(target)
 	if x.mode == invalid || isTyped(x.typ) || target == Typ[Invalid] {
 		return x.typ, nil, 0
 	}
@@ -691,7 +708,7 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 		return nil, nil, _InvalidUntypedConversion
 	}
 
-	switch t := optype(target).(type) {
+	switch t := under(target).(type) {
 	case *Basic:
 		if x.mode == constant_ {
 			v, code := check.representation(x, t)
@@ -723,8 +740,8 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 		default:
 			return nil, nil, _InvalidUntypedConversion
 		}
-	case *Sum:
-		ok := t.is(func(t Type) bool {
+	case *TypeParam:
+		ok := t.underIs(func(t Type) bool {
 			target, _, _ := check.implicitTypeAndValue(x, t)
 			return target != nil
 		})
@@ -735,7 +752,6 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 		// Update operand types to the default type rather than the target
 		// (interface) type: values must have concrete dynamic types.
 		// Untyped nil was handled upfront.
-		check.completeInterface(nopos, t)
 		if !t.Empty() {
 			return nil, nil, _InvalidUntypedConversion // cannot assign untyped values to non-empty interfaces
 		}
@@ -972,14 +988,28 @@ func (check *Checker) binary(x *operand, e syntax.Expr, lhs, rhs syntax.Expr, op
 		return
 	}
 
-	check.convertUntyped(x, y.typ)
-	if x.mode == invalid {
-		return
+	canMix := func(x, y *operand) bool {
+		if IsInterface(x.typ) || IsInterface(y.typ) {
+			return true
+		}
+		if isBoolean(x.typ) != isBoolean(y.typ) {
+			return false
+		}
+		if isString(x.typ) != isString(y.typ) {
+			return false
+		}
+		return true
 	}
-	check.convertUntyped(&y, x.typ)
-	if y.mode == invalid {
-		x.mode = invalid
-		return
+	if canMix(x, &y) {
+		check.convertUntyped(x, y.typ)
+		if x.mode == invalid {
+			return
+		}
+		check.convertUntyped(&y, x.typ)
+		if y.mode == invalid {
+			x.mode = invalid
+			return
+		}
 	}
 
 	if isComparison(op) {
@@ -987,7 +1017,7 @@ func (check *Checker) binary(x *operand, e syntax.Expr, lhs, rhs syntax.Expr, op
 		return
 	}
 
-	if !check.identical(x.typ, y.typ) {
+	if !Identical(x.typ, y.typ) {
 		// only report an error if we have valid types
 		// (otherwise we had an error reported elsewhere already)
 		if x.typ != Typ[Invalid] && y.typ != Typ[Invalid] {
@@ -1184,7 +1214,7 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 			goto Error
 		}
 
-		switch utyp := optype(base).(type) {
+		switch utyp := under(base).(type) {
 		case *Struct:
 			if len(e.ElemList) == 0 {
 				break
@@ -1316,7 +1346,7 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 					xkey := keyVal(x.val)
 					if asInterface(utyp.key) != nil {
 						for _, vtyp := range visited[xkey] {
-							if check.identical(vtyp, x.typ) {
+							if Identical(vtyp, x.typ) {
 								duplicate = true
 								break
 							}
@@ -1448,13 +1478,24 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 				case typexpr:
 					x.typ = &Pointer{base: x.typ}
 				default:
-					if typ := asPointer(x.typ); typ != nil {
-						x.mode = variable
-						x.typ = typ.base
-					} else {
-						check.errorf(x, invalidOp+"cannot indirect %s", x)
+					var base Type
+					if !underIs(x.typ, func(u Type) bool {
+						p, _ := u.(*Pointer)
+						if p == nil {
+							check.errorf(x, invalidOp+"cannot indirect %s", x)
+							return false
+						}
+						if base != nil && !Identical(p.base, base) {
+							check.errorf(x, invalidOp+"pointers of %s must have identical base types", x)
+							return false
+						}
+						base = p.base
+						return true
+					}) {
 						goto Error
 					}
+					x.mode = variable
+					x.typ = base
 				}
 				break
 			}
@@ -1537,7 +1578,7 @@ func (check *Checker) typeAssertion(pos syntax.Pos, x *operand, xtyp *Interface,
 	}
 	var msg string
 	if wrongType != nil {
-		if check.identical(method.typ, wrongType.typ) {
+		if Identical(method.typ, wrongType.typ) {
 			msg = fmt.Sprintf("missing method %s (%s has pointer receiver)", method.name, method.name)
 		} else {
 			msg = fmt.Sprintf("wrong type for method %s (have %s, want %s)", method.name, wrongType.typ, method.typ)
diff --git a/src/cmd/compile/internal/types2/index.go b/src/cmd/compile/internal/types2/index.go
index c94017a8fb9..e8755a1a68e 100644
--- a/src/cmd/compile/internal/types2/index.go
+++ b/src/cmd/compile/internal/types2/index.go
@@ -32,7 +32,7 @@ func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst boo
 		return false
 
 	case value:
-		if sig := asSignature(x.typ); sig != nil && len(sig.tparams) > 0 {
+		if sig := asSignature(x.typ); sig != nil && sig.TParams().Len() > 0 {
 			// function instantiation
 			return true
 		}
@@ -41,7 +41,7 @@ func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst boo
 	// ordinary index expression
 	valid := false
 	length := int64(-1) // valid if >= 0
-	switch typ := optype(x.typ).(type) {
+	switch typ := under(x.typ).(type) {
 	case *Basic:
 		if isString(typ) {
 			valid = true
@@ -80,7 +80,7 @@ func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst boo
 		index := check.singleIndex(e)
 		if index == nil {
 			x.mode = invalid
-			return
+			return false
 		}
 		var key operand
 		check.expr(&key, index)
@@ -89,87 +89,80 @@ func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst boo
 		x.mode = mapindex
 		x.typ = typ.elem
 		x.expr = e
-		return
+		return false
 
-	case *Sum:
-		// A sum type can be indexed if all of the sum's types
-		// support indexing and have the same index and element
-		// type. Special rules apply for maps in the sum type.
-		var tkey, telem Type // key is for map types only
-		nmaps := 0           // number of map types in sum type
-		if typ.is(func(t Type) bool {
-			var e Type
-			switch t := under(t).(type) {
+	case *TypeParam:
+		// TODO(gri) report detailed failure cause for better error messages
+		var tkey, telem Type // tkey != nil if we have maps
+		if typ.underIs(func(u Type) bool {
+			var key, elem Type
+			alen := int64(-1) // valid if >= 0
+			switch t := u.(type) {
 			case *Basic:
-				if isString(t) {
-					e = universeByte
-				}
-			case *Array:
-				e = t.elem
-			case *Pointer:
-				if t := asArray(t.base); t != nil {
-					e = t.elem
-				}
-			case *Slice:
-				e = t.elem
-			case *Map:
-				// If there are multiple maps in the sum type,
-				// they must have identical key types.
-				// TODO(gri) We may be able to relax this rule
-				// but it becomes complicated very quickly.
-				if tkey != nil && !Identical(t.key, tkey) {
+				if !isString(t) {
 					return false
 				}
-				tkey = t.key
-				e = t.elem
-				nmaps++
-			case *TypeParam:
-				check.errorf(x, "type of %s contains a type parameter - cannot index (implementation restriction)", x)
-			case *instance:
-				panic("unimplemented")
-			}
-			if e == nil || telem != nil && !Identical(e, telem) {
+				elem = universeByte
+			case *Array:
+				elem = t.elem
+				alen = t.len
+			case *Pointer:
+				a, _ := under(t.base).(*Array)
+				if a == nil {
+					return false
+				}
+				elem = a.elem
+				alen = a.len
+			case *Slice:
+				elem = t.elem
+			case *Map:
+				key = t.key
+				elem = t.elem
+			default:
 				return false
 			}
-			telem = e
+			assert(elem != nil)
+			if telem == nil {
+				// first type
+				tkey, telem = key, elem
+				length = alen
+			} else {
+				// all map keys must be identical (incl. all nil)
+				if !Identical(key, tkey) {
+					return false
+				}
+				// all element types must be identical
+				if !Identical(elem, telem) {
+					return false
+				}
+				tkey, telem = key, elem
+				// track the minimal length for arrays
+				if alen >= 0 && alen < length {
+					length = alen
+				}
+			}
 			return true
 		}) {
-			// If there are maps, the index expression must be assignable
-			// to the map key type (as for simple map index expressions).
-			if nmaps > 0 {
+			// For maps, the index expression must be assignable to the map key type.
+			if tkey != nil {
 				index := check.singleIndex(e)
 				if index == nil {
 					x.mode = invalid
-					return
+					return false
 				}
 				var key operand
 				check.expr(&key, index)
 				check.assignment(&key, tkey, "map index")
 				// ok to continue even if indexing failed - map element type is known
-
-				// If there are only maps, we are done.
-				if nmaps == len(typ.types) {
-					x.mode = mapindex
-					x.typ = telem
-					x.expr = e
-					return
-				}
-
-				// Otherwise we have mix of maps and other types. For
-				// now we require that the map key be an integer type.
-				// TODO(gri) This is probably not good enough.
-				valid = isInteger(tkey)
-				// avoid 2nd indexing error if indexing failed above
-				if !valid && key.mode == invalid {
-					x.mode = invalid
-					return
-				}
-				x.mode = value // map index expressions are not addressable
-			} else {
-				// no maps
-				valid = true
-				x.mode = variable
+				x.mode = mapindex
+				x.typ = telem
+				x.expr = e
+				return false
 			}
+
+			// no maps
+			valid = true
+			x.mode = variable
 			x.typ = telem
 		}
 	}
@@ -177,13 +170,13 @@ func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst boo
 	if !valid {
 		check.errorf(x, invalidOp+"cannot index %s", x)
 		x.mode = invalid
-		return
+		return false
 	}
 
 	index := check.singleIndex(e)
 	if index == nil {
 		x.mode = invalid
-		return
+		return false
 	}
 
 	// In pathological (invalid) cases (e.g.: type T1 [][[]T1{}[0][0]]T0)
@@ -206,7 +199,7 @@ func (check *Checker) sliceExpr(x *operand, e *syntax.SliceExpr) {
 
 	valid := false
 	length := int64(-1) // valid if >= 0
-	switch typ := optype(x.typ).(type) {
+	switch typ := under(x.typ).(type) {
 	case *Basic:
 		if isString(typ) {
 			if e.Full {
@@ -246,7 +239,7 @@ func (check *Checker) sliceExpr(x *operand, e *syntax.SliceExpr) {
 		valid = true
 		// x.typ doesn't change
 
-	case *Sum, *TypeParam:
+	case *TypeParam:
 		check.error(x, "generic slice expressions not yet implemented")
 		x.mode = invalid
 		return
diff --git a/src/cmd/compile/internal/types2/infer.go b/src/cmd/compile/internal/types2/infer.go
index f37d7f6477e..7bf507471d3 100644
--- a/src/cmd/compile/internal/types2/infer.go
+++ b/src/cmd/compile/internal/types2/infer.go
@@ -83,18 +83,18 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeName, targs []Type, p
 
 	// Substitute type arguments for their respective type parameters in params,
 	// if any. Note that nil targs entries are ignored by check.subst.
-	// TODO(gri) Can we avoid this (we're setting known type argumemts below,
+	// TODO(gri) Can we avoid this (we're setting known type arguments below,
 	//           but that doesn't impact the isParameterized check for now).
 	if params.Len() > 0 {
 		smap := makeSubstMap(tparams, targs)
-		params = check.subst(nopos, params, smap).(*Tuple)
+		params = check.subst(nopos, params, smap, nil).(*Tuple)
 	}
 
 	// --- 2 ---
 	// Unify parameter and argument types for generic parameters with typed arguments
 	// and collect the indices of generic parameters with untyped arguments.
 	// Terminology: generic parameter = function parameter with a type-parameterized type
-	u := newUnifier(check, false)
+	u := newUnifier(false)
 	u.x.init(tparams)
 
 	// Set the type arguments which we know already.
@@ -127,7 +127,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeName, targs []Type, p
 			}
 		}
 		smap := makeSubstMap(tparams, targs)
-		inferred := check.subst(arg.Pos(), tpar, smap)
+		inferred := check.subst(arg.Pos(), tpar, smap, nil)
 		if inferred != tpar {
 			check.errorf(arg, "%s %s of %s does not match inferred type %s for %s", kind, targ, arg.expr, inferred, tpar)
 		} else {
@@ -280,7 +280,7 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 	}()
 
 	switch t := typ.(type) {
-	case nil, *Basic: // TODO(gri) should nil be handled here?
+	case nil, *top, *Basic: // TODO(gri) should nil be handled here?
 		break
 
 	case *Array:
@@ -307,9 +307,6 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 			}
 		}
 
-	case *Sum:
-		return w.isParameterizedList(t.types)
-
 	case *Signature:
 		// t.tparams may not be nil if we are looking at a signature
 		// of a generic function type (or an interface method) that is
@@ -321,24 +318,15 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 		return w.isParameterized(t.params) || w.isParameterized(t.results)
 
 	case *Interface:
-		if t.allMethods != nil {
-			// interface is complete - quick test
-			for _, m := range t.allMethods {
-				if w.isParameterized(m.typ) {
-					return true
-				}
+		tset := t.typeSet()
+		for _, m := range tset.methods {
+			if w.isParameterized(m.typ) {
+				return true
 			}
-			return w.isParameterizedList(unpack(t.allTypes))
 		}
-
-		return t.iterate(func(t *Interface) bool {
-			for _, m := range t.methods {
-				if w.isParameterized(m.typ) {
-					return true
-				}
-			}
-			return w.isParameterizedList(unpack(t.types))
-		}, nil)
+		return tset.is(func(t *term) bool {
+			return w.isParameterized(t.typ)
+		})
 
 	case *Map:
 		return w.isParameterized(t.key) || w.isParameterized(t.elem)
@@ -347,15 +335,12 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 		return w.isParameterized(t.elem)
 
 	case *Named:
-		return w.isParameterizedList(t.targs)
+		return w.isParameterizedTypeList(t.targs)
 
 	case *TypeParam:
 		// t must be one of w.tparams
 		return t.index < len(w.tparams) && w.tparams[t.index].typ == t
 
-	case *instance:
-		return w.isParameterizedList(t.targs)
-
 	default:
 		unreachable()
 	}
@@ -363,7 +348,7 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 	return false
 }
 
-func (w *tpWalker) isParameterizedList(list []Type) bool {
+func (w *tpWalker) isParameterizedTypeList(list []Type) bool {
 	for _, t := range list {
 		if w.isParameterized(t) {
 			return true
@@ -385,7 +370,7 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	// Setup bidirectional unification between those structural bounds
 	// and the corresponding type arguments (which may be nil!).
-	u := newUnifier(check, false)
+	u := newUnifier(false)
 	u.x.init(tparams)
 	u.y = u.x // type parameters between LHS and RHS of unification are identical
 
@@ -399,7 +384,7 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 	// Unify type parameters with their structural constraints, if any.
 	for _, tpar := range tparams {
 		typ := tpar.typ.(*TypeParam)
-		sbound := check.structuralType(typ.bound)
+		sbound := typ.structuralType()
 		if sbound != nil {
 			if !u.unify(typ, sbound) {
 				if report {
@@ -412,8 +397,8 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	// u.x.types() now contains the incoming type arguments plus any additional type
 	// arguments for which there were structural constraints. The newly inferred non-
-	// nil entries may still contain references to other type parameters. For instance,
-	// for [A any, B interface{type []C}, C interface{type *A}], if A == int
+	// nil entries may still contain references to other type parameters.
+	// For instance, for [A any, B interface{ []C }, C interface{ *A }], if A == int
 	// was given, unification produced the type list [int, []C, *A]. We eliminate the
 	// remaining type parameters by substituting the type parameters in this type list
 	// until nothing changes anymore.
@@ -442,7 +427,7 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 		n := 0
 		for _, index := range dirty {
 			t0 := types[index]
-			if t1 := check.subst(nopos, t0, smap); t1 != t0 {
+			if t1 := check.subst(nopos, t0, smap, nil); t1 != t0 {
 				types[index] = t1
 				dirty[n] = index
 				n++
@@ -472,16 +457,3 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	return
 }
-
-// structuralType returns the structural type of a constraint, if any.
-func (check *Checker) structuralType(constraint Type) Type {
-	if iface, _ := under(constraint).(*Interface); iface != nil {
-		check.completeInterface(nopos, iface)
-		types := unpack(iface.allTypes)
-		if len(types) == 1 {
-			return types[0]
-		}
-		return nil
-	}
-	return constraint
-}
diff --git a/src/cmd/compile/internal/types2/instantiate.go b/src/cmd/compile/internal/types2/instantiate.go
index 0df52e851c9..fff26354560 100644
--- a/src/cmd/compile/internal/types2/instantiate.go
+++ b/src/cmd/compile/internal/types2/instantiate.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// This file implements instantiation of generic types
+// through substitution of type parameters by type arguments.
+
 package types2
 
 import (
@@ -9,23 +12,26 @@ import (
 	"fmt"
 )
 
-// Instantiate instantiates the type typ with the given type arguments.
-// typ must be a *Named or a *Signature type, it must be generic, and
-// its number of type parameters must match the number of provided type
-// arguments. The result is a new, instantiated (not generic) type of
-// the same kind (either a *Named or a *Signature). The type arguments
-// are not checked against the constraints of the type parameters.
+// Instantiate instantiates the type typ with the given type arguments
+// targs. To check type constraint satisfaction, verify must be set.
+// pos and posList correspond to the instantiation and type argument
+// positions respectively; posList may be nil or shorter than the number
+// of type arguments provided.
+// typ must be a *Named or a *Signature type, and its number of type
+// parameters must match the number of provided type arguments.
+// The receiver (check) may be nil if and only if verify is not set.
+// The result is a new, instantiated (not generic) type of the same kind
+// (either a *Named or a *Signature).
 // Any methods attached to a *Named are simply copied; they are not
 // instantiated.
-func Instantiate(pos syntax.Pos, typ Type, targs []Type) (res Type) {
-	// TODO(gri) This code is basically identical to the prolog
-	//           in Checker.instantiate. Factor.
+func (check *Checker) Instantiate(pos syntax.Pos, typ Type, targs []Type, posList []syntax.Pos, verify bool) (res Type) {
+	// TODO(gri) What is better here: work with TypeParams, or work with TypeNames?
 	var tparams []*TypeName
 	switch t := typ.(type) {
 	case *Named:
-		tparams = t.tparams
+		return check.instantiateLazy(pos, t, targs, posList, verify)
 	case *Signature:
-		tparams = t.tparams
+		tparams = t.TParams().list()
 		defer func() {
 			// If we had an unexpected failure somewhere don't panic below when
 			// asserting res.(*Signature). Check for *Signature in case Typ[Invalid]
@@ -44,20 +50,187 @@ func Instantiate(pos syntax.Pos, typ Type, targs []Type) (res Type) {
 			// anymore; we need to set tparams to nil.
 			res.(*Signature).tparams = nil
 		}()
-
 	default:
+		// only types and functions can be generic
 		panic(fmt.Sprintf("%v: cannot instantiate %v", pos, typ))
 	}
 
+	inst := check.instantiate(pos, typ, tparams, targs, posList, nil)
+	if verify && len(tparams) == len(targs) {
+		check.verify(pos, tparams, targs, posList)
+	}
+	return inst
+}
+
+func (check *Checker) instantiate(pos syntax.Pos, typ Type, tparams []*TypeName, targs []Type, posList []syntax.Pos, typMap map[string]*Named) (res Type) {
 	// the number of supplied types must match the number of type parameters
 	if len(targs) != len(tparams) {
+		// TODO(gri) provide better error message
+		if check != nil {
+			check.errorf(pos, "got %d arguments but %d type parameters", len(targs), len(tparams))
+			return Typ[Invalid]
+		}
 		panic(fmt.Sprintf("%v: got %d arguments but %d type parameters", pos, len(targs), len(tparams)))
 	}
 
+	if check != nil && check.conf.Trace {
+		check.trace(pos, "-- instantiating %s with %s", typ, typeListString(targs))
+		check.indent++
+		defer func() {
+			check.indent--
+			var under Type
+			if res != nil {
+				// Calling under() here may lead to endless instantiations.
+				// Test case: type T[P any] T[P]
+				// TODO(gri) investigate if that's a bug or to be expected.
+				under = safeUnderlying(res)
+			}
+			check.trace(pos, "=> %s (under = %s)", res, under)
+		}()
+	}
+
+	assert(len(posList) <= len(targs))
+
 	if len(tparams) == 0 {
 		return typ // nothing to do (minor optimization)
 	}
 
-	smap := makeSubstMap(tparams, targs)
-	return (*Checker)(nil).subst(pos, typ, smap)
+	return check.subst(pos, typ, makeSubstMap(tparams, targs), typMap)
+}
+
+// instantiateLazy avoids actually instantiating the type until needed. typ
+// must be a *Named type.
+func (check *Checker) instantiateLazy(pos syntax.Pos, base *Named, targs []Type, posList []syntax.Pos, verify bool) Type {
+	if verify && base.TParams().Len() == len(targs) {
+		// TODO: lift the nil check in verify to here.
+		check.later(func() {
+			check.verify(pos, base.tparams.list(), targs, posList)
+		})
+	}
+
+	h := instantiatedHash(base, targs)
+	if check != nil {
+		// typ may already have been instantiated with identical type arguments. In
+		// that case, re-use the existing instance.
+		if named := check.typMap[h]; named != nil {
+			return named
+		}
+	}
+
+	tname := NewTypeName(pos, base.obj.pkg, base.obj.name, nil)
+	named := check.newNamed(tname, base, nil, nil, nil) // methods and tparams are set when named is loaded
+	named.targs = targs
+	named.instance = &instance{pos, posList}
+	if check != nil {
+		check.typMap[h] = named
+	}
+
+	return named
+}
+
+func (check *Checker) verify(pos syntax.Pos, tparams []*TypeName, targs []Type, posList []syntax.Pos) {
+	if check == nil {
+		panic("cannot have nil Checker if verifying constraints")
+	}
+
+	smap := makeSubstMap(tparams, targs)
+	for i, tname := range tparams {
+		// best position for error reporting
+		pos := pos
+		if i < len(posList) {
+			pos = posList[i]
+		}
+
+		// stop checking bounds after the first failure
+		if !check.satisfies(pos, targs[i], tname.typ.(*TypeParam), smap) {
+			break
+		}
+	}
+}
+
+// satisfies reports whether the type argument targ satisfies the constraint of type parameter
+// parameter tpar (after any of its type parameters have been substituted through smap).
+// A suitable error is reported if the result is false.
+// TODO(gri) This should be a method of interfaces or type sets.
+func (check *Checker) satisfies(pos syntax.Pos, targ Type, tpar *TypeParam, smap substMap) bool {
+	iface := tpar.iface()
+	if iface.Empty() {
+		return true // no type bound
+	}
+
+	// The type parameter bound is parameterized with the same type parameters
+	// as the instantiated type; before we can use it for bounds checking we
+	// need to instantiate it with the type arguments with which we instantiate
+	// the parameterized type.
+	iface = check.subst(pos, iface, smap, nil).(*Interface)
+
+	// if iface is comparable, targ must be comparable
+	// TODO(gri) the error messages needs to be better, here
+	if iface.IsComparable() && !Comparable(targ) {
+		if tpar := asTypeParam(targ); tpar != nil && tpar.iface().typeSet().IsAll() {
+			check.softErrorf(pos, "%s has no constraints", targ)
+			return false
+		}
+		check.softErrorf(pos, "%s does not satisfy comparable", targ)
+		return false
+	}
+
+	// targ must implement iface (methods)
+	// - check only if we have methods
+	if iface.NumMethods() > 0 {
+		// If the type argument is a pointer to a type parameter, the type argument's
+		// method set is empty.
+		// TODO(gri) is this what we want? (spec question)
+		if base, isPtr := deref(targ); isPtr && asTypeParam(base) != nil {
+			check.errorf(pos, "%s has no methods", targ)
+			return false
+		}
+		if m, wrong := check.missingMethod(targ, iface, true); m != nil {
+			// TODO(gri) needs to print updated name to avoid major confusion in error message!
+			//           (print warning for now)
+			// Old warning:
+			// check.softErrorf(pos, "%s does not satisfy %s (warning: name not updated) = %s (missing method %s)", targ, tpar.bound, iface, m)
+			if wrong != nil {
+				// TODO(gri) This can still report uninstantiated types which makes the error message
+				//           more difficult to read then necessary.
+				check.softErrorf(pos,
+					"%s does not satisfy %s: wrong method signature\n\tgot  %s\n\twant %s",
+					targ, tpar.bound, wrong, m,
+				)
+			} else {
+				check.softErrorf(pos, "%s does not satisfy %s (missing method %s)", targ, tpar.bound, m.name)
+			}
+			return false
+		}
+	}
+
+	// targ's underlying type must also be one of the interface types listed, if any
+	if !iface.typeSet().hasTerms() {
+		return true // nothing to do
+	}
+
+	// If targ is itself a type parameter, each of its possible types, but at least one, must be in the
+	// list of iface types (i.e., the targ type list must be a non-empty subset of the iface types).
+	if targ := asTypeParam(targ); targ != nil {
+		targBound := targ.iface()
+		if !targBound.typeSet().hasTerms() {
+			check.softErrorf(pos, "%s does not satisfy %s (%s has no type constraints)", targ, tpar.bound, targ)
+			return false
+		}
+		if !targBound.typeSet().subsetOf(iface.typeSet()) {
+			// TODO(gri) need better error message
+			check.softErrorf(pos, "%s does not satisfy %s", targ, tpar.bound)
+			return false
+		}
+		return true
+	}
+
+	// Otherwise, targ's type or underlying type must also be one of the interface types listed, if any.
+	if !iface.typeSet().includes(targ) {
+		// TODO(gri) better error message
+		check.softErrorf(pos, "%s does not satisfy %s", targ, tpar.bound)
+		return false
+	}
+
+	return true
 }
diff --git a/src/cmd/compile/internal/types2/interface.go b/src/cmd/compile/internal/types2/interface.go
new file mode 100644
index 00000000000..2617f748de6
--- /dev/null
+++ b/src/cmd/compile/internal/types2/interface.go
@@ -0,0 +1,226 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import "cmd/compile/internal/syntax"
+
+// ----------------------------------------------------------------------------
+// API
+
+// An Interface represents an interface type.
+type Interface struct {
+	obj       *TypeName     // corresponding declared object; or nil (for better error messages)
+	methods   []*Func       // ordered list of explicitly declared methods
+	embeddeds []Type        // ordered list of explicitly embedded elements
+	embedPos  *[]syntax.Pos // positions of embedded elements; or nil (for error messages) - use pointer to save space
+	complete  bool          // indicates that all fields (except for tset) are set up
+
+	tset *TypeSet // type set described by this interface, computed lazily
+}
+
+// typeSet returns the type set for interface t.
+func (t *Interface) typeSet() *TypeSet { return computeInterfaceTypeSet(nil, nopos, t) }
+
+// emptyInterface represents the empty interface
+var emptyInterface = Interface{complete: true, tset: &topTypeSet}
+
+// NewInterface returns a new interface for the given methods and embedded types.
+// NewInterface takes ownership of the provided methods and may modify their types
+// by setting missing receivers.
+//
+// Deprecated: Use NewInterfaceType instead which allows arbitrary embedded types.
+func NewInterface(methods []*Func, embeddeds []*Named) *Interface {
+	tnames := make([]Type, len(embeddeds))
+	for i, t := range embeddeds {
+		tnames[i] = t
+	}
+	return NewInterfaceType(methods, tnames)
+}
+
+// NewInterfaceType returns a new interface for the given methods and embedded types.
+// NewInterfaceType takes ownership of the provided methods and may modify their types
+// by setting missing receivers.
+func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
+	if len(methods) == 0 && len(embeddeds) == 0 {
+		return &emptyInterface
+	}
+
+	// set method receivers if necessary
+	typ := new(Interface)
+	for _, m := range methods {
+		if sig := m.typ.(*Signature); sig.recv == nil {
+			sig.recv = NewVar(m.pos, m.pkg, "", typ)
+		}
+	}
+
+	// sort for API stability
+	sortMethods(methods)
+
+	typ.methods = methods
+	typ.embeddeds = embeddeds
+	typ.complete = true
+
+	return typ
+}
+
+// NumExplicitMethods returns the number of explicitly declared methods of interface t.
+func (t *Interface) NumExplicitMethods() int { return len(t.methods) }
+
+// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods().
+// The methods are ordered by their unique Id.
+func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] }
+
+// NumEmbeddeds returns the number of embedded types in interface t.
+func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) }
+
+// Embedded returns the i'th embedded defined (*Named) type of interface t for 0 <= i < t.NumEmbeddeds().
+// The result is nil if the i'th embedded type is not a defined type.
+//
+// Deprecated: Use EmbeddedType which is not restricted to defined (*Named) types.
+func (t *Interface) Embedded(i int) *Named { tname, _ := t.embeddeds[i].(*Named); return tname }
+
+// EmbeddedType returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds().
+func (t *Interface) EmbeddedType(i int) Type { return t.embeddeds[i] }
+
+// NumMethods returns the total number of methods of interface t.
+func (t *Interface) NumMethods() int { return t.typeSet().NumMethods() }
+
+// Method returns the i'th method of interface t for 0 <= i < t.NumMethods().
+// The methods are ordered by their unique Id.
+func (t *Interface) Method(i int) *Func { return t.typeSet().Method(i) }
+
+// Empty reports whether t is the empty interface.
+func (t *Interface) Empty() bool { return t.typeSet().IsAll() }
+
+// IsComparable reports whether each type in interface t's type set is comparable.
+func (t *Interface) IsComparable() bool { return t.typeSet().IsComparable() }
+
+// IsConstraint reports whether interface t is not just a method set.
+func (t *Interface) IsConstraint() bool { return !t.typeSet().IsMethodSet() }
+
+func (t *Interface) Underlying() Type { return t }
+func (t *Interface) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (check *Checker) interfaceType(ityp *Interface, iface *syntax.InterfaceType, def *Named) {
+	var tlist []syntax.Expr // types collected from all type lists
+	var tname *syntax.Name  // most recent "type" name
+
+	addEmbedded := func(pos syntax.Pos, typ Type) {
+		ityp.embeddeds = append(ityp.embeddeds, typ)
+		if ityp.embedPos == nil {
+			ityp.embedPos = new([]syntax.Pos)
+		}
+		*ityp.embedPos = append(*ityp.embedPos, pos)
+	}
+
+	for _, f := range iface.MethodList {
+		if f.Name == nil {
+			// We have an embedded type; possibly a union of types.
+			addEmbedded(posFor(f.Type), parseUnion(check, flattenUnion(nil, f.Type)))
+			continue
+		}
+		// f.Name != nil
+
+		// We have a method with name f.Name, or a type of a type list (f.Name.Value == "type").
+		name := f.Name.Value
+		if name == "_" {
+			if check.conf.CompilerErrorMessages {
+				check.error(f.Name, "methods must have a unique non-blank name")
+			} else {
+				check.error(f.Name, "invalid method name _")
+			}
+			continue // ignore
+		}
+
+		// TODO(gri) Remove type list handling once the parser doesn't accept type lists anymore.
+		if name == "type" {
+			// Report an error for the first type list per interface
+			// if we don't allow type lists, but continue.
+			if !check.conf.AllowTypeLists && tlist == nil {
+				check.softErrorf(f.Name, "use generalized embedding syntax instead of a type list")
+			}
+			// For now, collect all type list entries as if it
+			// were a single union, where each union element is
+			// of the form ~T.
+			op := new(syntax.Operation)
+			// We should also set the position (but there is no setter);
+			// we don't care because this code will eventually go away.
+			op.Op = syntax.Tilde
+			op.X = f.Type
+			tlist = append(tlist, op)
+			// Report an error if we have multiple type lists in an
+			// interface, but only if they are permitted in the first place.
+			if check.conf.AllowTypeLists && tname != nil && tname != f.Name {
+				check.error(f.Name, "cannot have multiple type lists in an interface")
+			}
+			tname = f.Name
+			continue
+		}
+
+		typ := check.typ(f.Type)
+		sig, _ := typ.(*Signature)
+		if sig == nil {
+			if typ != Typ[Invalid] {
+				check.errorf(f.Type, invalidAST+"%s is not a method signature", typ)
+			}
+			continue // ignore
+		}
+
+		// Always type-check method type parameters but complain if they are not enabled.
+		// (This extra check is needed here because interface method signatures don't have
+		// a receiver specification.)
+		if sig.tparams != nil && !acceptMethodTypeParams {
+			check.error(f.Type, "methods cannot have type parameters")
+		}
+
+		// use named receiver type if available (for better error messages)
+		var recvTyp Type = ityp
+		if def != nil {
+			recvTyp = def
+		}
+		sig.recv = NewVar(f.Name.Pos(), check.pkg, "", recvTyp)
+
+		m := NewFunc(f.Name.Pos(), check.pkg, name, sig)
+		check.recordDef(f.Name, m)
+		ityp.methods = append(ityp.methods, m)
+	}
+
+	// If we saw a type list, add it like an embedded union.
+	if tlist != nil {
+		// Types T in a type list are added as ~T expressions but we don't
+		// have the position of the '~'. Use the first type position instead.
+		addEmbedded(tlist[0].(*syntax.Operation).X.Pos(), parseUnion(check, tlist))
+	}
+
+	// All methods and embedded elements for this interface are collected;
+	// i.e., this interface is may be used in a type set computation.
+	ityp.complete = true
+
+	if len(ityp.methods) == 0 && len(ityp.embeddeds) == 0 {
+		// empty interface
+		ityp.tset = &topTypeSet
+		return
+	}
+
+	// sort for API stability
+	// (don't sort embeddeds: they must correspond to *embedPos entries)
+	sortMethods(ityp.methods)
+
+	// Compute type set with a non-nil *Checker as soon as possible
+	// to report any errors. Subsequent uses of type sets will use
+	// this computed type set and won't need to pass in a *Checker.
+	check.later(func() { computeInterfaceTypeSet(check, iface.Pos(), ityp) })
+}
+
+func flattenUnion(list []syntax.Expr, x syntax.Expr) []syntax.Expr {
+	if o, _ := x.(*syntax.Operation); o != nil && o.Op == syntax.Or {
+		list = flattenUnion(list, o.X)
+		x = o.Y
+	}
+	return append(list, x)
+}
diff --git a/src/cmd/compile/internal/types2/issues_test.go b/src/cmd/compile/internal/types2/issues_test.go
index e716a480385..9890b79323a 100644
--- a/src/cmd/compile/internal/types2/issues_test.go
+++ b/src/cmd/compile/internal/types2/issues_test.go
@@ -321,7 +321,7 @@ func TestIssue25627(t *testing.T) {
 			}
 		}
 
-		syntax.Walk(f, func(n syntax.Node) bool {
+		syntax.Crawl(f, func(n syntax.Node) bool {
 			if decl, _ := n.(*syntax.TypeDecl); decl != nil {
 				if tv, ok := info.Types[decl.Type]; ok && decl.Name.Value == "T" {
 					want := strings.Count(src, ";") + 1
@@ -402,8 +402,9 @@ func TestIssue28282(t *testing.T) {
 	// create type interface { error }
 	et := Universe.Lookup("error").Type()
 	it := NewInterfaceType(nil, []Type{et})
-	it.Complete()
 	// verify that after completing the interface, the embedded method remains unchanged
+	// (interfaces are "completed" lazily now, so the completion happens implicitly when
+	// accessing Method(0))
 	want := et.Underlying().(*Interface).Method(0)
 	got := it.Method(0)
 	if got != want {
diff --git a/src/cmd/compile/internal/types2/labels.go b/src/cmd/compile/internal/types2/labels.go
index d3206988b54..6f02e2fc969 100644
--- a/src/cmd/compile/internal/types2/labels.go
+++ b/src/cmd/compile/internal/types2/labels.go
@@ -32,7 +32,8 @@ func (check *Checker) labels(body *syntax.BlockStmt) {
 	}
 
 	// spec: "It is illegal to define a label that is never used."
-	for _, obj := range all.elems {
+	for name, obj := range all.elems {
+		obj = resolve(name, obj)
 		if lbl := obj.(*Label); !lbl.used {
 			check.softErrorf(lbl.pos, "label %s declared but not used", lbl.name)
 		}
diff --git a/src/cmd/compile/internal/types2/lookup.go b/src/cmd/compile/internal/types2/lookup.go
index 78299502e9c..3779d17b3db 100644
--- a/src/cmd/compile/internal/types2/lookup.go
+++ b/src/cmd/compile/internal/types2/lookup.go
@@ -6,6 +6,11 @@
 
 package types2
 
+// Internal use of LookupFieldOrMethod: If the obj result is a method
+// associated with a concrete (non-interface) type, the method's signature
+// may not be fully set up. Call Checker.objDecl(obj, nil) before accessing
+// the method's type.
+
 // LookupFieldOrMethod looks up a field or method with given package and name
 // in T and returns the corresponding *Var or *Func, an index sequence, and a
 // bool indicating if there were any pointer indirections on the path to the
@@ -33,19 +38,6 @@ package types2
 //	the method's formal receiver base type, nor was the receiver addressable.
 //
 func LookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
-	return (*Checker)(nil).lookupFieldOrMethod(T, addressable, pkg, name)
-}
-
-// Internal use of Checker.lookupFieldOrMethod: If the obj result is a method
-// associated with a concrete (non-interface) type, the method's signature
-// may not be fully set up. Call Checker.objDecl(obj, nil) before accessing
-// the method's type.
-// TODO(gri) Now that we provide the *Checker, we can probably remove this
-// caveat by calling Checker.objDecl from lookupFieldOrMethod. Investigate.
-
-// lookupFieldOrMethod is like the external version but completes interfaces
-// as necessary.
-func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
 	// Methods cannot be associated to a named pointer type
 	// (spec: "The type denoted by T is called the receiver base type;
 	// it must not be a pointer or interface type and it must be declared
@@ -54,8 +46,8 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 	// pointer type but discard the result if it is a method since we would
 	// not have found it for T (see also issue 8590).
 	if t := asNamed(T); t != nil {
-		if p, _ := t.underlying.(*Pointer); p != nil {
-			obj, index, indirect = check.rawLookupFieldOrMethod(p, false, pkg, name)
+		if p, _ := safeUnderlying(t).(*Pointer); p != nil {
+			obj, index, indirect = lookupFieldOrMethod(p, false, pkg, name)
 			if _, ok := obj.(*Func); ok {
 				return nil, nil, false
 			}
@@ -63,7 +55,7 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 		}
 	}
 
-	return check.rawLookupFieldOrMethod(T, addressable, pkg, name)
+	return lookupFieldOrMethod(T, addressable, pkg, name)
 }
 
 // TODO(gri) The named type consolidation and seen maps below must be
@@ -71,10 +63,9 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 //           types always have only one representation (even when imported
 //           indirectly via different packages.)
 
-// rawLookupFieldOrMethod should only be called by lookupFieldOrMethod and missingMethod.
-func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
+// lookupFieldOrMethod should only be called by LookupFieldOrMethod and missingMethod.
+func lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
 	// WARNING: The code in this function is extremely subtle - do not modify casually!
-	//          This function and NewMethodSet should be kept in sync.
 
 	if name == "_" {
 		return // blank fields/methods are never found
@@ -82,10 +73,12 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 
 	typ, isPtr := deref(T)
 
-	// *typ where typ is an interface has no methods.
-	// Be cautious: typ may be nil (issue 39634, crash #3).
-	if typ == nil || isPtr && IsInterface(typ) {
-		return
+	// *typ where typ is an interface or type parameter has no methods.
+	switch under(typ).(type) {
+	case *Interface, *TypeParam:
+		if isPtr {
+			return
+		}
 	}
 
 	// Start with typ as single entry at shallowest depth.
@@ -126,6 +119,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 				seen[named] = true
 
 				// look for a matching attached method
+				named.load()
 				if i, m := lookupMethod(named.methods, pkg, name); m != nil {
 					// potential match
 					// caution: method may not have a proper signature yet
@@ -181,9 +175,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 
 			case *Interface:
 				// look for a matching method
-				// TODO(gri) t.allMethods is sorted - use binary search
-				check.completeInterface(nopos, t)
-				if i, m := lookupMethod(t.allMethods, pkg, name); m != nil {
+				if i, m := t.typeSet().LookupMethod(pkg, name); m != nil {
 					assert(m.typ != nil)
 					index = concat(e.index, i)
 					if obj != nil || e.multiples {
@@ -194,7 +186,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 				}
 
 			case *TypeParam:
-				if i, m := lookupMethod(t.Bound().allMethods, pkg, name); m != nil {
+				if i, m := t.iface().typeSet().LookupMethod(pkg, name); m != nil {
 					assert(m.typ != nil)
 					index = concat(e.index, i)
 					if obj != nil || e.multiples {
@@ -229,7 +221,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 			return
 		}
 
-		current = check.consolidateMultiples(next)
+		current = consolidateMultiples(next)
 	}
 
 	return nil, nil, false // not found
@@ -246,7 +238,7 @@ type embeddedType struct {
 // consolidateMultiples collects multiple list entries with the same type
 // into a single entry marked as containing multiples. The result is the
 // consolidated list.
-func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
+func consolidateMultiples(list []embeddedType) []embeddedType {
 	if len(list) <= 1 {
 		return list // at most one entry - nothing to do
 	}
@@ -254,7 +246,7 @@ func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
 	n := 0                     // number of entries w/ unique type
 	prev := make(map[Type]int) // index at which type was previously seen
 	for _, e := range list {
-		if i, found := check.lookupType(prev, e.typ); found {
+		if i, found := lookupType(prev, e.typ); found {
 			list[i].multiples = true
 			// ignore this entry
 		} else {
@@ -266,14 +258,14 @@ func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
 	return list[:n]
 }
 
-func (check *Checker) lookupType(m map[Type]int, typ Type) (int, bool) {
+func lookupType(m map[Type]int, typ Type) (int, bool) {
 	// fast path: maybe the types are equal
 	if i, found := m[typ]; found {
 		return i, true
 	}
 
 	for t, i := range m {
-		if check.identical(t, typ) {
+		if Identical(t, typ) {
 			return i, true
 		}
 	}
@@ -306,22 +298,18 @@ func MissingMethod(V Type, T *Interface, static bool) (method *Func, wrongType b
 // To improve error messages, also report the wrong signature
 // when the method exists on *V instead of V.
 func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method, wrongType *Func) {
-	check.completeInterface(nopos, T)
-
 	// fast path for common case
 	if T.Empty() {
 		return
 	}
 
 	if ityp := asInterface(V); ityp != nil {
-		check.completeInterface(nopos, ityp)
-		// TODO(gri) allMethods is sorted - can do this more efficiently
-		for _, m := range T.allMethods {
-			_, f := lookupMethod(ityp.allMethods, m.pkg, m.name)
+		// TODO(gri) the methods are sorted - could do this more efficiently
+		for _, m := range T.typeSet().methods {
+			_, f := ityp.typeSet().LookupMethod(m.pkg, m.name)
 
 			if f == nil {
-				// if m is the magic method == we're ok (interfaces are comparable)
-				if m.name == "==" || !static {
+				if !static {
 					continue
 				}
 				return m, f
@@ -330,17 +318,20 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 			// both methods must have the same number of type parameters
 			ftyp := f.typ.(*Signature)
 			mtyp := m.typ.(*Signature)
-			if len(ftyp.tparams) != len(mtyp.tparams) {
+			if ftyp.TParams().Len() != mtyp.TParams().Len() {
 				return m, f
 			}
+			if !acceptMethodTypeParams && ftyp.TParams().Len() > 0 {
+				panic("method with type parameters")
+			}
 
 			// If the methods have type parameters we don't care whether they
 			// are the same or not, as long as they match up. Use unification
 			// to see if they can be made to match.
 			// TODO(gri) is this always correct? what about type bounds?
 			// (Alternative is to rename/subst type parameters and compare.)
-			u := newUnifier(check, true)
-			u.x.init(ftyp.tparams)
+			u := newUnifier(true)
+			u.x.init(ftyp.TParams().list())
 			if !u.unify(ftyp, mtyp) {
 				return m, f
 			}
@@ -352,14 +343,14 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 	// A concrete type implements T if it implements all methods of T.
 	Vd, _ := deref(V)
 	Vn := asNamed(Vd)
-	for _, m := range T.allMethods {
+	for _, m := range T.typeSet().methods {
 		// TODO(gri) should this be calling lookupFieldOrMethod instead (and why not)?
-		obj, _, _ := check.rawLookupFieldOrMethod(V, false, m.pkg, m.name)
+		obj, _, _ := lookupFieldOrMethod(V, false, m.pkg, m.name)
 
 		// Check if *V implements this method of T.
 		if obj == nil {
 			ptr := NewPointer(V)
-			obj, _, _ = check.rawLookupFieldOrMethod(ptr, false, m.pkg, m.name)
+			obj, _, _ = lookupFieldOrMethod(ptr, false, m.pkg, m.name)
 			if obj != nil {
 				return m, obj.(*Func)
 			}
@@ -368,10 +359,6 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// we must have a method (not a field of matching function type)
 		f, _ := obj.(*Func)
 		if f == nil {
-			// if m is the magic method == and V is comparable, we're ok
-			if m.name == "==" && Comparable(V) {
-				continue
-			}
 			return m, nil
 		}
 
@@ -383,9 +370,12 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// both methods must have the same number of type parameters
 		ftyp := f.typ.(*Signature)
 		mtyp := m.typ.(*Signature)
-		if len(ftyp.tparams) != len(mtyp.tparams) {
+		if ftyp.TParams().Len() != mtyp.TParams().Len() {
 			return m, f
 		}
+		if !acceptMethodTypeParams && ftyp.TParams().Len() > 0 {
+			panic("method with type parameters")
+		}
 
 		// If V is a (instantiated) generic type, its methods are still
 		// parameterized using the original (declaration) receiver type
@@ -394,17 +384,17 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// In order to compare the signatures, substitute the receiver
 		// type parameters of ftyp with V's instantiation type arguments.
 		// This lazily instantiates the signature of method f.
-		if Vn != nil && len(Vn.tparams) > 0 {
+		if Vn != nil && Vn.TParams().Len() > 0 {
 			// Be careful: The number of type arguments may not match
 			// the number of receiver parameters. If so, an error was
 			// reported earlier but the length discrepancy is still
 			// here. Exit early in this case to prevent an assertion
 			// failure in makeSubstMap.
 			// TODO(gri) Can we avoid this check by fixing the lengths?
-			if len(ftyp.rparams) != len(Vn.targs) {
+			if len(ftyp.RParams().list()) != len(Vn.targs) {
 				return
 			}
-			ftyp = check.subst(nopos, ftyp, makeSubstMap(ftyp.rparams, Vn.targs)).(*Signature)
+			ftyp = check.subst(nopos, ftyp, makeSubstMap(ftyp.RParams().list(), Vn.targs), nil).(*Signature)
 		}
 
 		// If the methods have type parameters we don't care whether they
@@ -412,8 +402,21 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// to see if they can be made to match.
 		// TODO(gri) is this always correct? what about type bounds?
 		// (Alternative is to rename/subst type parameters and compare.)
-		u := newUnifier(check, true)
-		u.x.init(ftyp.tparams)
+		u := newUnifier(true)
+		if ftyp.TParams().Len() > 0 {
+			// We reach here only if we accept method type parameters.
+			// In this case, unification must consider any receiver
+			// and method type parameters as "free" type parameters.
+			assert(acceptMethodTypeParams)
+			// We don't have a test case for this at the moment since
+			// we can't parse method type parameters. Keeping the
+			// unimplemented call so that we test this code if we
+			// enable method type parameters.
+			unimplemented()
+			u.x.init(append(ftyp.RParams().list(), ftyp.TParams().list()...))
+		} else {
+			u.x.init(ftyp.RParams().list())
+		}
 		if !u.unify(ftyp, mtyp) {
 			return m, f
 		}
diff --git a/src/cmd/compile/internal/types2/map.go b/src/cmd/compile/internal/types2/map.go
new file mode 100644
index 00000000000..0d3464caae7
--- /dev/null
+++ b/src/cmd/compile/internal/types2/map.go
@@ -0,0 +1,24 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A Map represents a map type.
+type Map struct {
+	key, elem Type
+}
+
+// NewMap returns a new map for the given key and element types.
+func NewMap(key, elem Type) *Map {
+	return &Map{key: key, elem: elem}
+}
+
+// Key returns the key type of map m.
+func (m *Map) Key() Type { return m.key }
+
+// Elem returns the element type of map m.
+func (m *Map) Elem() Type { return m.elem }
+
+func (t *Map) Underlying() Type { return t }
+func (t *Map) String() string   { return TypeString(t, nil) }
diff --git a/src/cmd/compile/internal/types2/named.go b/src/cmd/compile/internal/types2/named.go
new file mode 100644
index 00000000000..3ce9c5b0c79
--- /dev/null
+++ b/src/cmd/compile/internal/types2/named.go
@@ -0,0 +1,292 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"cmd/compile/internal/syntax"
+	"sync"
+)
+
+// TODO(gri) Clean up Named struct below; specifically the fromRHS field (can we use underlying?).
+
+// A Named represents a named (defined) type.
+type Named struct {
+	check      *Checker
+	info       typeInfo    // for cycle detection
+	obj        *TypeName   // corresponding declared object for declared types; placeholder for instantiated types
+	orig       *Named      // original, uninstantiated type
+	fromRHS    Type        // type (on RHS of declaration) this *Named type is derived from (for cycle reporting)
+	underlying Type        // possibly a *Named during setup; never a *Named once set up completely
+	instance   *instance   // position information for lazy instantiation, or nil
+	tparams    *TParamList // type parameters, or nil
+	targs      []Type      // type arguments (after instantiation), or nil
+	methods    []*Func     // methods declared for this type (not the method set of this type); signatures are type-checked lazily
+
+	resolve func(*Named) ([]*TypeName, Type, []*Func)
+	once    sync.Once
+}
+
+// NewNamed returns a new named type for the given type name, underlying type, and associated methods.
+// If the given type name obj doesn't have a type yet, its type is set to the returned named type.
+// The underlying type must not be a *Named.
+func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
+	if _, ok := underlying.(*Named); ok {
+		panic("underlying type must not be *Named")
+	}
+	return (*Checker)(nil).newNamed(obj, nil, underlying, nil, methods)
+}
+
+func (t *Named) load() *Named {
+	// If t is an instantiated type, it derives its methods and tparams from its
+	// base type. Since we expect type parameters and methods to be set after a
+	// call to load, we must load the base and copy here.
+	//
+	// underlying is set when t is expanded.
+	//
+	// By convention, a type instance is loaded iff its tparams are set.
+	if len(t.targs) > 0 && t.tparams == nil {
+		t.orig.load()
+		t.tparams = t.orig.tparams
+		t.methods = t.orig.methods
+	}
+	if t.resolve == nil {
+		return t
+	}
+
+	t.once.Do(func() {
+		// TODO(mdempsky): Since we're passing t to resolve anyway
+		// (necessary because types2 expects the receiver type for methods
+		// on defined interface types to be the Named rather than the
+		// underlying Interface), maybe it should just handle calling
+		// SetTParams, SetUnderlying, and AddMethod instead?  Those
+		// methods would need to support reentrant calls though.  It would
+		// also make the API more future-proof towards further extensions
+		// (like SetTParams).
+
+		tparams, underlying, methods := t.resolve(t)
+
+		switch underlying.(type) {
+		case nil, *Named:
+			panic("invalid underlying type")
+		}
+
+		t.tparams = bindTParams(tparams)
+		t.underlying = underlying
+		t.methods = methods
+	})
+	return t
+}
+
+// newNamed is like NewNamed but with a *Checker receiver and additional orig argument.
+func (check *Checker) newNamed(obj *TypeName, orig *Named, underlying Type, tparams *TParamList, methods []*Func) *Named {
+	typ := &Named{check: check, obj: obj, orig: orig, fromRHS: underlying, underlying: underlying, tparams: tparams, methods: methods}
+	if typ.orig == nil {
+		typ.orig = typ
+	}
+	if obj.typ == nil {
+		obj.typ = typ
+	}
+	// Ensure that typ is always expanded, at which point the check field can be
+	// nilled out.
+	//
+	// Note that currently we cannot nil out check inside typ.under(), because
+	// it's possible that typ is expanded multiple times.
+	//
+	// TODO(gri): clean this up so that under is the only function mutating
+	//            named types.
+	if check != nil {
+		check.later(func() {
+			switch typ.under().(type) {
+			case *Named:
+				panic("unexpanded underlying type")
+			}
+			typ.check = nil
+		})
+	}
+	return typ
+}
+
+// Obj returns the type name for the declaration defining the named type t. For
+// instantiated types, this is the type name of the base type.
+func (t *Named) Obj() *TypeName {
+	return t.orig.obj // for non-instances this is the same as t.obj
+}
+
+// Orig returns the original generic type an instantiated type is derived from.
+// If t is not an instantiated type, the result is t.
+func (t *Named) Orig() *Named { return t.orig }
+
+// TODO(gri) Come up with a better representation and API to distinguish
+//           between parameterized instantiated and non-instantiated types.
+
+// TParams returns the type parameters of the named type t, or nil.
+// The result is non-nil for an (originally) parameterized type even if it is instantiated.
+func (t *Named) TParams() *TParamList { return t.load().tparams }
+
+// SetTParams sets the type parameters of the named type t.
+func (t *Named) SetTParams(tparams []*TypeName) { t.load().tparams = bindTParams(tparams) }
+
+// TArgs returns the type arguments after instantiation of the named type t, or nil if not instantiated.
+func (t *Named) TArgs() []Type { return t.targs }
+
+// NumMethods returns the number of explicit methods whose receiver is named type t.
+func (t *Named) NumMethods() int { return len(t.load().methods) }
+
+// Method returns the i'th method of named type t for 0 <= i < t.NumMethods().
+func (t *Named) Method(i int) *Func { return t.load().methods[i] }
+
+// SetUnderlying sets the underlying type and marks t as complete.
+func (t *Named) SetUnderlying(underlying Type) {
+	if underlying == nil {
+		panic("underlying type must not be nil")
+	}
+	if _, ok := underlying.(*Named); ok {
+		panic("underlying type must not be *Named")
+	}
+	t.load().underlying = underlying
+}
+
+// AddMethod adds method m unless it is already in the method list.
+func (t *Named) AddMethod(m *Func) {
+	t.load()
+	if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 {
+		t.methods = append(t.methods, m)
+	}
+}
+
+func (t *Named) Underlying() Type { return t.load().expand(nil).underlying }
+func (t *Named) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// under returns the expanded underlying type of n0; possibly by following
+// forward chains of named types. If an underlying type is found, resolve
+// the chain by setting the underlying type for each defined type in the
+// chain before returning it. If no underlying type is found or a cycle
+// is detected, the result is Typ[Invalid]. If a cycle is detected and
+// n0.check != nil, the cycle is reported.
+func (n0 *Named) under() Type {
+	u := n0.Underlying()
+
+	// If the underlying type of a defined type is not a defined
+	// (incl. instance) type, then that is the desired underlying
+	// type.
+	var n1 *Named
+	switch u1 := u.(type) {
+	case nil:
+		return Typ[Invalid]
+	default:
+		// common case
+		return u
+	case *Named:
+		// handled below
+		n1 = u1
+	}
+
+	if n0.check == nil {
+		panic("Named.check == nil but type is incomplete")
+	}
+
+	// Invariant: after this point n0 as well as any named types in its
+	// underlying chain should be set up when this function exits.
+	check := n0.check
+	n := n0
+
+	seen := make(map[*Named]int) // types that need their underlying resolved
+	var path []Object            // objects encountered, for cycle reporting
+
+loop:
+	for {
+		seen[n] = len(seen)
+		path = append(path, n.obj)
+		n = n1
+		if i, ok := seen[n]; ok {
+			// cycle
+			check.cycleError(path[i:])
+			u = Typ[Invalid]
+			break
+		}
+		u = n.Underlying()
+		switch u1 := u.(type) {
+		case nil:
+			u = Typ[Invalid]
+			break loop
+		default:
+			break loop
+		case *Named:
+			// Continue collecting *Named types in the chain.
+			n1 = u1
+		}
+	}
+
+	for n := range seen {
+		// We should never have to update the underlying type of an imported type;
+		// those underlying types should have been resolved during the import.
+		// Also, doing so would lead to a race condition (was issue #31749).
+		// Do this check always, not just in debug mode (it's cheap).
+		if n.obj.pkg != check.pkg {
+			panic("imported type with unresolved underlying type")
+		}
+		n.underlying = u
+	}
+
+	return u
+}
+
+func (n *Named) setUnderlying(typ Type) {
+	if n != nil {
+		n.underlying = typ
+	}
+}
+
+// instance holds position information for use in lazy instantiation.
+//
+// TODO(rfindley): come up with a better name for this type, now that its usage
+// has changed.
+type instance struct {
+	pos     syntax.Pos   // position of type instantiation; for error reporting only
+	posList []syntax.Pos // position of each targ; for error reporting only
+}
+
+// expand ensures that the underlying type of n is instantiated.
+// The underlying type will be Typ[Invalid] if there was an error.
+func (n *Named) expand(typMap map[string]*Named) *Named {
+	if n.instance != nil {
+		// n must be loaded before instantiation, in order to have accurate
+		// tparams. This is done implicitly by the call to n.TParams, but making it
+		// explicit is harmless: load is idempotent.
+		n.load()
+		if typMap == nil {
+			if n.check != nil {
+				typMap = n.check.typMap
+			} else {
+				// If we're instantiating lazily, we might be outside the scope of a
+				// type-checking pass. In that case we won't have a pre-existing
+				// typMap, but don't want to create a duplicate of the current instance
+				// in the process of expansion.
+				h := instantiatedHash(n.orig, n.targs)
+				typMap = map[string]*Named{h: n}
+			}
+		}
+
+		inst := n.check.instantiate(n.instance.pos, n.orig.underlying, n.TParams().list(), n.targs, n.instance.posList, typMap)
+		n.underlying = inst
+		n.fromRHS = inst
+		n.instance = nil
+	}
+	return n
+}
+
+// safeUnderlying returns the underlying of typ without expanding instances, to
+// avoid infinite recursion.
+//
+// TODO(rfindley): eliminate this function or give it a better name.
+func safeUnderlying(typ Type) Type {
+	if t, _ := typ.(*Named); t != nil {
+		return t.load().underlying
+	}
+	return typ.Underlying()
+}
diff --git a/src/cmd/compile/internal/types2/object.go b/src/cmd/compile/internal/types2/object.go
index 844bc34b6a3..8263ccae0cb 100644
--- a/src/cmd/compile/internal/types2/object.go
+++ b/src/cmd/compile/internal/types2/object.go
@@ -186,6 +186,45 @@ func (obj *object) sameId(pkg *Package, name string) bool {
 	return pkg.path == obj.pkg.path
 }
 
+// less reports whether object a is ordered before object b.
+//
+// Objects are ordered nil before non-nil, exported before
+// non-exported, then by name, and finally (for non-exported
+// functions) by package height and path.
+func (a *object) less(b *object) bool {
+	if a == b {
+		return false
+	}
+
+	// Nil before non-nil.
+	if a == nil {
+		return true
+	}
+	if b == nil {
+		return false
+	}
+
+	// Exported functions before non-exported.
+	ea := isExported(a.name)
+	eb := isExported(b.name)
+	if ea != eb {
+		return ea
+	}
+
+	// Order by name and then (for non-exported names) by package.
+	if a.name != b.name {
+		return a.name < b.name
+	}
+	if !ea {
+		if a.pkg.height != b.pkg.height {
+			return a.pkg.height < b.pkg.height
+		}
+		return a.pkg.path < b.pkg.path
+	}
+
+	return false
+}
+
 // A PkgName represents an imported Go package.
 // PkgNames don't have a type.
 type PkgName struct {
@@ -237,6 +276,14 @@ func NewTypeName(pos syntax.Pos, pkg *Package, name string, typ Type) *TypeName
 	return &TypeName{object{nil, pos, pkg, name, typ, 0, colorFor(typ), nopos}}
 }
 
+// NewTypeNameLazy returns a new defined type like NewTypeName, but it
+// lazily calls resolve to finish constructing the Named object.
+func NewTypeNameLazy(pos syntax.Pos, pkg *Package, name string, resolve func(named *Named) (tparams []*TypeName, underlying Type, methods []*Func)) *TypeName {
+	obj := NewTypeName(pos, pkg, name, nil)
+	NewNamed(obj, nil, nil).resolve = resolve
+	return obj
+}
+
 // IsAlias reports whether obj is an alias name for a type.
 func (obj *TypeName) IsAlias() bool {
 	switch t := obj.typ.(type) {
@@ -329,36 +376,6 @@ func (obj *Func) FullName() string {
 // Scope returns the scope of the function's body block.
 func (obj *Func) Scope() *Scope { return obj.typ.(*Signature).scope }
 
-// Less reports whether function a is ordered before function b.
-//
-// Functions are ordered exported before non-exported, then by name,
-// and finally (for non-exported functions) by package path.
-//
-// TODO(gri) The compiler also sorts by package height before package
-//           path for non-exported names.
-func (a *Func) less(b *Func) bool {
-	if a == b {
-		return false
-	}
-
-	// Exported functions before non-exported.
-	ea := isExported(a.name)
-	eb := isExported(b.name)
-	if ea != eb {
-		return ea
-	}
-
-	// Order by name and then (for non-exported names) by package.
-	if a.name != b.name {
-		return a.name < b.name
-	}
-	if !ea {
-		return a.pkg.path < b.pkg.path
-	}
-
-	return false
-}
-
 func (*Func) isDependency() {} // a function may be a dependency of an initialization expression
 
 // A Label represents a declared label.
@@ -458,6 +475,9 @@ func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) {
 		if _, ok := typ.(*Basic); ok {
 			return
 		}
+		if named, _ := typ.(*Named); named != nil && named.TParams().Len() > 0 {
+			writeTParamList(buf, named.TParams().list(), qf, nil)
+		}
 		if tname.IsAlias() {
 			buf.WriteString(" =")
 		} else {
diff --git a/src/cmd/compile/internal/types2/object_test.go b/src/cmd/compile/internal/types2/object_test.go
index 7f63c793325..a86733a5c99 100644
--- a/src/cmd/compile/internal/types2/object_test.go
+++ b/src/cmd/compile/internal/types2/object_test.go
@@ -25,7 +25,7 @@ func TestIsAlias(t *testing.T) {
 	check(Unsafe.Scope().Lookup("Pointer").(*TypeName), false)
 	for _, name := range Universe.Names() {
 		if obj, _ := Universe.Lookup(name).(*TypeName); obj != nil {
-			check(obj, name == "byte" || name == "rune")
+			check(obj, name == "any" || name == "byte" || name == "rune")
 		}
 	}
 
diff --git a/src/cmd/compile/internal/types2/operand.go b/src/cmd/compile/internal/types2/operand.go
index 455d8b5dd1d..8336451e9ce 100644
--- a/src/cmd/compile/internal/types2/operand.go
+++ b/src/cmd/compile/internal/types2/operand.go
@@ -176,16 +176,20 @@ func operandString(x *operand, qf Qualifier) string {
 	if hasType {
 		if x.typ != Typ[Invalid] {
 			var intro string
-			switch {
-			case isGeneric(x.typ):
-				intro = " of generic type "
-			case asTypeParam(x.typ) != nil:
-				intro = " of type parameter type "
-			default:
+			var tpar *TypeParam
+			if isGeneric(x.typ) {
+				intro = " of parameterized type "
+			} else if tpar = asTypeParam(x.typ); tpar != nil {
+				intro = " of type parameter "
+			} else {
 				intro = " of type "
 			}
 			buf.WriteString(intro)
 			WriteType(&buf, x.typ, qf)
+			if tpar != nil {
+				buf.WriteString(" constrained by ")
+				WriteType(&buf, tpar.bound, qf) // do not compute interface type sets here
+			}
 		} else {
 			buf.WriteString(" with invalid type")
 		}
@@ -248,20 +252,35 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 
 	V := x.typ
 
+	const debugAssignableTo = false
+	if debugAssignableTo && check != nil {
+		check.dump("V = %s", V)
+		check.dump("T = %s", T)
+	}
+
 	// x's type is identical to T
-	if check.identical(V, T) {
+	if Identical(V, T) {
 		return true, 0
 	}
 
 	Vu := optype(V)
 	Tu := optype(T)
 
+	if debugAssignableTo && check != nil {
+		check.dump("Vu = %s", Vu)
+		check.dump("Tu = %s", Tu)
+	}
+
 	// x is an untyped value representable by a value of type T.
 	if isUntyped(Vu) {
-		if t, ok := Tu.(*Sum); ok {
-			return t.is(func(t Type) bool {
+		if t, ok := Tu.(*TypeParam); ok {
+			return t.is(func(t *term) bool {
 				// TODO(gri) this could probably be more efficient
-				ok, _ := x.assignableTo(check, t, reason)
+				if t.tilde {
+					// TODO(gri) We need to check assignability
+					//           for the underlying type of x.
+				}
+				ok, _ := x.assignableTo(check, t.typ, reason)
 				return ok
 			}), _IncompatibleAssign
 		}
@@ -272,7 +291,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 
 	// x's type V and T have identical underlying types
 	// and at least one of V or T is not a named type
-	if check.identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) {
+	if Identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) {
 		return true, 0
 	}
 
@@ -281,7 +300,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 		if m, wrongType := check.missingMethod(V, Ti, true); m != nil /* Implements(V, Ti) */ {
 			if reason != nil {
 				if wrongType != nil {
-					if check.identical(m.typ, wrongType.typ) {
+					if Identical(m.typ, wrongType.typ) {
 						*reason = fmt.Sprintf("missing method %s (%s has pointer receiver)", m.name, m.name)
 					} else {
 						*reason = fmt.Sprintf("wrong type for method %s (have %s, want %s)", m.Name(), wrongType.typ, m.typ)
@@ -300,7 +319,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 	// type, x's type V and T have identical element types,
 	// and at least one of V or T is not a named type
 	if Vc, ok := Vu.(*Chan); ok && Vc.dir == SendRecv {
-		if Tc, ok := Tu.(*Chan); ok && check.identical(Vc.elem, Tc.elem) {
+		if Tc, ok := Tu.(*Chan); ok && Identical(Vc.elem, Tc.elem) {
 			return !isNamed(V) || !isNamed(T), _InvalidChanAssign
 		}
 	}
diff --git a/src/cmd/compile/internal/types2/package.go b/src/cmd/compile/internal/types2/package.go
index 31b1e717877..8044e7e6a76 100644
--- a/src/cmd/compile/internal/types2/package.go
+++ b/src/cmd/compile/internal/types2/package.go
@@ -13,8 +13,9 @@ type Package struct {
 	path     string
 	name     string
 	scope    *Scope
-	complete bool
 	imports  []*Package
+	height   int
+	complete bool
 	fake     bool // scope lookup errors are silently dropped if package is fake (internal use only)
 	cgo      bool // uses of this package will be rewritten into uses of declarations from _cgo_gotypes.go
 }
@@ -22,8 +23,14 @@ type Package struct {
 // NewPackage returns a new Package for the given package path and name.
 // The package is not complete and contains no explicit imports.
 func NewPackage(path, name string) *Package {
+	return NewPackageHeight(path, name, 0)
+}
+
+// NewPackageHeight is like NewPackage, but allows specifying the
+// package's height.
+func NewPackageHeight(path, name string, height int) *Package {
 	scope := NewScope(Universe, nopos, nopos, fmt.Sprintf("package %q", path))
-	return &Package{path: path, name: name, scope: scope}
+	return &Package{path: path, name: name, scope: scope, height: height}
 }
 
 // Path returns the package path.
@@ -32,13 +39,22 @@ func (pkg *Package) Path() string { return pkg.path }
 // Name returns the package name.
 func (pkg *Package) Name() string { return pkg.name }
 
+// Height returns the package height.
+func (pkg *Package) Height() int { return pkg.height }
+
 // SetName sets the package name.
 func (pkg *Package) SetName(name string) { pkg.name = name }
 
 // Scope returns the (complete or incomplete) package scope
 // holding the objects declared at package level (TypeNames,
 // Consts, Vars, and Funcs).
-func (pkg *Package) Scope() *Scope { return pkg.scope }
+// For a nil pkg receiver, Scope returns the Universe scope.
+func (pkg *Package) Scope() *Scope {
+	if pkg != nil {
+		return pkg.scope
+	}
+	return Universe
+}
 
 // A package is complete if its scope contains (at least) all
 // exported objects; otherwise it is incomplete.
diff --git a/src/cmd/compile/internal/types2/pointer.go b/src/cmd/compile/internal/types2/pointer.go
new file mode 100644
index 00000000000..63055fc6b05
--- /dev/null
+++ b/src/cmd/compile/internal/types2/pointer.go
@@ -0,0 +1,19 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A Pointer represents a pointer type.
+type Pointer struct {
+	base Type // element type
+}
+
+// NewPointer returns a new pointer type for the given element (base) type.
+func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} }
+
+// Elem returns the element type for the given pointer p.
+func (p *Pointer) Elem() Type { return p.base }
+
+func (p *Pointer) Underlying() Type { return p }
+func (p *Pointer) String() string   { return TypeString(p, nil) }
diff --git a/src/cmd/compile/internal/types2/predicates.go b/src/cmd/compile/internal/types2/predicates.go
index ae186a0b5d1..3c883e1ab5c 100644
--- a/src/cmd/compile/internal/types2/predicates.go
+++ b/src/cmd/compile/internal/types2/predicates.go
@@ -10,7 +10,7 @@ package types2
 // isNamed may be called with types that are not fully set up.
 func isNamed(typ Type) bool {
 	switch typ.(type) {
-	case *Basic, *Named, *TypeParam, *instance:
+	case *Basic, *Named, *TypeParam:
 		return true
 	}
 	return false
@@ -21,15 +21,15 @@ func isNamed(typ Type) bool {
 func isGeneric(typ Type) bool {
 	// A parameterized type is only instantiated if it doesn't have an instantiation already.
 	named, _ := typ.(*Named)
-	return named != nil && named.obj != nil && named.tparams != nil && named.targs == nil
+	return named != nil && named.obj != nil && named.targs == nil && named.TParams() != nil
 }
 
 func is(typ Type, what BasicInfo) bool {
-	switch t := optype(typ).(type) {
+	switch t := under(typ).(type) {
 	case *Basic:
 		return t.info&what != 0
-	case *Sum:
-		return t.is(func(typ Type) bool { return is(typ, what) })
+	case *TypeParam:
+		return t.underIs(func(t Type) bool { return is(t, what) })
 	}
 	return false
 }
@@ -56,10 +56,7 @@ func isNumericOrString(typ Type) bool { return is(typ, IsNumeric|IsString) }
 // are not fully set up.
 func isTyped(typ Type) bool {
 	// isTyped is called with types that are not fully
-	// set up. Must not call Basic()!
-	// A *Named or *instance type is always typed, so
-	// we only need to check if we have a true *Basic
-	// type.
+	// set up. Must not call asBasic()!
 	t, _ := typ.(*Basic)
 	return t == nil || t.info&IsUntyped == 0
 }
@@ -96,19 +93,7 @@ func comparable(T Type, seen map[Type]bool) bool {
 	}
 	seen[T] = true
 
-	// If T is a type parameter not constrained by any type
-	// list (i.e., it's underlying type is the top type),
-	// T is comparable if it has the == method. Otherwise,
-	// the underlying type "wins". For instance
-	//
-	//     interface{ comparable; type []byte }
-	//
-	// is not comparable because []byte is not comparable.
-	if t := asTypeParam(T); t != nil && optype(t) == theTop {
-		return t.Bound().IsComparable()
-	}
-
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Basic:
 		// assume invalid types to be comparable
 		// to avoid follow-up errors
@@ -124,42 +109,25 @@ func comparable(T Type, seen map[Type]bool) bool {
 		return true
 	case *Array:
 		return comparable(t.elem, seen)
-	case *Sum:
-		pred := func(t Type) bool {
-			return comparable(t, seen)
-		}
-		return t.is(pred)
 	case *TypeParam:
-		return t.Bound().IsComparable()
+		return t.iface().IsComparable()
 	}
 	return false
 }
 
 // hasNil reports whether a type includes the nil value.
 func hasNil(typ Type) bool {
-	switch t := optype(typ).(type) {
+	switch t := under(typ).(type) {
 	case *Basic:
 		return t.kind == UnsafePointer
 	case *Slice, *Pointer, *Signature, *Interface, *Map, *Chan:
 		return true
-	case *Sum:
-		return t.is(hasNil)
+	case *TypeParam:
+		return t.underIs(hasNil)
 	}
 	return false
 }
 
-// identical reports whether x and y are identical types.
-// Receivers of Signature types are ignored.
-func (check *Checker) identical(x, y Type) bool {
-	return check.identical0(x, y, true, nil)
-}
-
-// identicalIgnoreTags reports whether x and y are identical types if tags are ignored.
-// Receivers of Signature types are ignored.
-func (check *Checker) identicalIgnoreTags(x, y Type) bool {
-	return check.identical0(x, y, false, nil)
-}
-
 // An ifacePair is a node in a stack of interface type pairs compared for identity.
 type ifacePair struct {
 	x, y *Interface
@@ -171,11 +139,7 @@ func (p *ifacePair) identical(q *ifacePair) bool {
 }
 
 // For changes to this code the corresponding changes should be made to unifier.nify.
-func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
-	// types must be expanded for comparison
-	x = expandf(x)
-	y = expandf(y)
-
+func identical(x, y Type, cmpTags bool, p *ifacePair) bool {
 	if x == y {
 		return true
 	}
@@ -195,13 +159,13 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 		if y, ok := y.(*Array); ok {
 			// If one or both array lengths are unknown (< 0) due to some error,
 			// assume they are the same to avoid spurious follow-on errors.
-			return (x.len < 0 || y.len < 0 || x.len == y.len) && check.identical0(x.elem, y.elem, cmpTags, p)
+			return (x.len < 0 || y.len < 0 || x.len == y.len) && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Slice:
 		// Two slice types are identical if they have identical element types.
 		if y, ok := y.(*Slice); ok {
-			return check.identical0(x.elem, y.elem, cmpTags, p)
+			return identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Struct:
@@ -216,7 +180,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 					if f.embedded != g.embedded ||
 						cmpTags && x.Tag(i) != y.Tag(i) ||
 						!f.sameId(g.pkg, g.name) ||
-						!check.identical0(f.typ, g.typ, cmpTags, p) {
+						!identical(f.typ, g.typ, cmpTags, p) {
 						return false
 					}
 				}
@@ -227,7 +191,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	case *Pointer:
 		// Two pointer types are identical if they have identical base types.
 		if y, ok := y.(*Pointer); ok {
-			return check.identical0(x.base, y.base, cmpTags, p)
+			return identical(x.base, y.base, cmpTags, p)
 		}
 
 	case *Tuple:
@@ -238,7 +202,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 				if x != nil {
 					for i, v := range x.vars {
 						w := y.vars[i]
-						if !check.identical0(v.typ, w.typ, cmpTags, p) {
+						if !identical(v.typ, w.typ, cmpTags, p) {
 							return false
 						}
 					}
@@ -256,49 +220,27 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 		// parameter names.
 		if y, ok := y.(*Signature); ok {
 			return x.variadic == y.variadic &&
-				check.identicalTParams(x.tparams, y.tparams, cmpTags, p) &&
-				check.identical0(x.params, y.params, cmpTags, p) &&
-				check.identical0(x.results, y.results, cmpTags, p)
-		}
-
-	case *Sum:
-		// Two sum types are identical if they contain the same types.
-		// (Sum types always consist of at least two types. Also, the
-		// the set (list) of types in a sum type consists of unique
-		// types - each type appears exactly once. Thus, two sum types
-		// must contain the same number of types to have chance of
-		// being equal.
-		if y, ok := y.(*Sum); ok && len(x.types) == len(y.types) {
-			// Every type in x.types must be in y.types.
-			// Quadratic algorithm, but probably good enough for now.
-			// TODO(gri) we need a fast quick type ID/hash for all types.
-		L:
-			for _, x := range x.types {
-				for _, y := range y.types {
-					if Identical(x, y) {
-						continue L // x is in y.types
-					}
-				}
-				return false // x is not in y.types
-			}
-			return true
+				identicalTParams(x.TParams().list(), y.TParams().list(), cmpTags, p) &&
+				identical(x.params, y.params, cmpTags, p) &&
+				identical(x.results, y.results, cmpTags, p)
 		}
 
 	case *Interface:
+		// Two interface types are identical if they describe the same type sets.
+		// With the existing implementation restriction, this simplifies to:
+		//
 		// Two interface types are identical if they have the same set of methods with
-		// the same names and identical function types. Lower-case method names from
-		// different packages are always different. The order of the methods is irrelevant.
+		// the same names and identical function types, and if any type restrictions
+		// are the same. Lower-case method names from different packages are always
+		// different. The order of the methods is irrelevant.
 		if y, ok := y.(*Interface); ok {
-			// If identical0 is called (indirectly) via an external API entry point
-			// (such as Identical, IdenticalIgnoreTags, etc.), check is nil. But in
-			// that case, interfaces are expected to be complete and lazy completion
-			// here is not needed.
-			if check != nil {
-				check.completeInterface(nopos, x)
-				check.completeInterface(nopos, y)
+			xset := x.typeSet()
+			yset := y.typeSet()
+			if !xset.terms.equal(yset.terms) {
+				return false
 			}
-			a := x.allMethods
-			b := y.allMethods
+			a := xset.methods
+			b := yset.methods
 			if len(a) == len(b) {
 				// Interface types are the only types where cycles can occur
 				// that are not "terminated" via named types; and such cycles
@@ -335,7 +277,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 				}
 				for i, f := range a {
 					g := b[i]
-					if f.Id() != g.Id() || !check.identical0(f.typ, g.typ, cmpTags, q) {
+					if f.Id() != g.Id() || !identical(f.typ, g.typ, cmpTags, q) {
 						return false
 					}
 				}
@@ -346,20 +288,44 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	case *Map:
 		// Two map types are identical if they have identical key and value types.
 		if y, ok := y.(*Map); ok {
-			return check.identical0(x.key, y.key, cmpTags, p) && check.identical0(x.elem, y.elem, cmpTags, p)
+			return identical(x.key, y.key, cmpTags, p) && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Chan:
 		// Two channel types are identical if they have identical value types
 		// and the same direction.
 		if y, ok := y.(*Chan); ok {
-			return x.dir == y.dir && check.identical0(x.elem, y.elem, cmpTags, p)
+			return x.dir == y.dir && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Named:
 		// Two named types are identical if their type names originate
 		// in the same type declaration.
 		if y, ok := y.(*Named); ok {
+			x.expand(nil)
+			y.expand(nil)
+
+			xargs := x.TArgs()
+			yargs := y.TArgs()
+
+			if len(xargs) != len(yargs) {
+				return false
+			}
+
+			if len(xargs) > 0 {
+				// Instances are identical if their original type and type arguments
+				// are identical.
+				if !Identical(x.orig, y.orig) {
+					return false
+				}
+				for i, xa := range xargs {
+					if !Identical(xa, yargs[i]) {
+						return false
+					}
+				}
+				return true
+			}
+
 			// TODO(gri) Why is x == y not sufficient? And if it is,
 			//           we can just return false here because x == y
 			//           is caught in the very beginning of this function.
@@ -369,13 +335,9 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	case *TypeParam:
 		// nothing to do (x and y being equal is caught in the very beginning of this function)
 
-	// case *instance:
-	//	unreachable since types are expanded
-
-	case *bottom, *top:
-		// Either both types are theBottom, or both are theTop in which
-		// case the initial x == y check will have caught them. Otherwise
-		// they are not identical.
+	case *top:
+		// Either both types are theTop in which case the initial x == y check
+		// will have caught them. Otherwise they are not identical.
 
 	case nil:
 		// avoid a crash in case of nil type
@@ -387,13 +349,13 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	return false
 }
 
-func (check *Checker) identicalTParams(x, y []*TypeName, cmpTags bool, p *ifacePair) bool {
+func identicalTParams(x, y []*TypeName, cmpTags bool, p *ifacePair) bool {
 	if len(x) != len(y) {
 		return false
 	}
 	for i, x := range x {
 		y := y[i]
-		if !check.identical0(x.typ.(*TypeParam).bound, y.typ.(*TypeParam).bound, cmpTags, p) {
+		if !identical(x.typ.(*TypeParam).bound, y.typ.(*TypeParam).bound, cmpTags, p) {
 			return false
 		}
 	}
diff --git a/src/cmd/compile/internal/types2/resolver.go b/src/cmd/compile/internal/types2/resolver.go
index fa30650bd44..018a20cfb2d 100644
--- a/src/cmd/compile/internal/types2/resolver.go
+++ b/src/cmd/compile/internal/types2/resolver.go
@@ -196,6 +196,7 @@ func (check *Checker) importPackage(pos syntax.Pos, path, dir string) *Package {
 // methods with receiver base type names.
 func (check *Checker) collectObjects() {
 	pkg := check.pkg
+	pkg.height = 0
 
 	// pkgImports is the set of packages already imported by any package file seen
 	// so far. Used to avoid duplicate entries in pkg.imports. Allocate and populate
@@ -253,6 +254,15 @@ func (check *Checker) collectObjects() {
 					continue
 				}
 
+				if imp == Unsafe {
+					// typecheck ignores imports of package unsafe for
+					// calculating height.
+					// TODO(mdempsky): Revisit this. This seems fine, but I
+					// don't remember explicitly considering this case.
+				} else if h := imp.height + 1; h > pkg.height {
+					pkg.height = h
+				}
+
 				// local name overrides imported package name
 				name := imp.name
 				if s.LocalPkgName != nil {
@@ -265,7 +275,7 @@ func (check *Checker) collectObjects() {
 				}
 
 				if name == "init" {
-					check.error(s.LocalPkgName, "cannot import package as init - init must be a func")
+					check.error(s, "cannot import package as init - init must be a func")
 					continue
 				}
 
@@ -298,22 +308,26 @@ func (check *Checker) collectObjects() {
 						check.dotImportMap = make(map[dotImportKey]*PkgName)
 					}
 					// merge imported scope with file scope
-					for _, obj := range imp.scope.elems {
+					for name, obj := range imp.scope.elems {
+						// Note: Avoid eager resolve(name, obj) here, so we only
+						// resolve dot-imported objects as needed.
+
 						// A package scope may contain non-exported objects,
 						// do not import them!
-						if obj.Exported() {
+						if isExported(name) {
 							// declare dot-imported object
 							// (Do not use check.declare because it modifies the object
 							// via Object.setScopePos, which leads to a race condition;
 							// the object may be imported into more than one file scope
 							// concurrently. See issue #32154.)
-							if alt := fileScope.Insert(obj); alt != nil {
+							if alt := fileScope.Lookup(name); alt != nil {
 								var err error_
-								err.errorf(s.LocalPkgName, "%s redeclared in this block", obj.Name())
+								err.errorf(s.LocalPkgName, "%s redeclared in this block", alt.Name())
 								err.recordAltDecl(alt)
 								check.report(&err)
 							} else {
-								check.dotImportMap[dotImportKey{fileScope, obj}] = pkgName
+								fileScope.insert(name, obj)
+								check.dotImportMap[dotImportKey{fileScope, name}] = pkgName
 							}
 						}
 					}
@@ -459,8 +473,9 @@ func (check *Checker) collectObjects() {
 
 	// verify that objects in package and file scopes have different names
 	for _, scope := range fileScopes {
-		for _, obj := range scope.elems {
-			if alt := pkg.scope.Lookup(obj.Name()); alt != nil {
+		for name, obj := range scope.elems {
+			if alt := pkg.scope.Lookup(name); alt != nil {
+				obj = resolve(name, obj)
 				var err error_
 				if pkg, ok := obj.(*PkgName); ok {
 					err.errorf(alt, "%s already declared through import of %s", alt.Name(), pkg.Imported())
diff --git a/src/cmd/compile/internal/types2/resolver_test.go b/src/cmd/compile/internal/types2/resolver_test.go
index aee435ff5fb..a02abce081b 100644
--- a/src/cmd/compile/internal/types2/resolver_test.go
+++ b/src/cmd/compile/internal/types2/resolver_test.go
@@ -143,7 +143,7 @@ func TestResolveIdents(t *testing.T) {
 
 	// check that qualified identifiers are resolved
 	for _, f := range files {
-		syntax.Walk(f, func(n syntax.Node) bool {
+		syntax.Crawl(f, func(n syntax.Node) bool {
 			if s, ok := n.(*syntax.SelectorExpr); ok {
 				if x, ok := s.X.(*syntax.Name); ok {
 					obj := uses[x]
@@ -177,7 +177,7 @@ func TestResolveIdents(t *testing.T) {
 	foundDefs := make(map[*syntax.Name]bool)
 	var both []string
 	for _, f := range files {
-		syntax.Walk(f, func(n syntax.Node) bool {
+		syntax.Crawl(f, func(n syntax.Node) bool {
 			if x, ok := n.(*syntax.Name); ok {
 				var objects int
 				if _, found := uses[x]; found {
diff --git a/src/cmd/compile/internal/types2/sanitize.go b/src/cmd/compile/internal/types2/sanitize.go
deleted file mode 100644
index 64a2dedc7d8..00000000000
--- a/src/cmd/compile/internal/types2/sanitize.go
+++ /dev/null
@@ -1,202 +0,0 @@
-// Copyright 2020 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package types2
-
-// sanitizeInfo walks the types contained in info to ensure that all instances
-// are expanded.
-//
-// This includes some objects that may be shared across concurrent
-// type-checking passes (such as those in the universe scope), so we are
-// careful here not to write types that are already sanitized. This avoids a
-// data race as any shared types should already be sanitized.
-func sanitizeInfo(info *Info) {
-	var s sanitizer = make(map[Type]Type)
-
-	// Note: Some map entries are not references.
-	// If modified, they must be assigned back.
-
-	for e, tv := range info.Types {
-		if typ := s.typ(tv.Type); typ != tv.Type {
-			tv.Type = typ
-			info.Types[e] = tv
-		}
-	}
-
-	for e, inf := range info.Inferred {
-		changed := false
-		for i, targ := range inf.Targs {
-			if typ := s.typ(targ); typ != targ {
-				inf.Targs[i] = typ
-				changed = true
-			}
-		}
-		if typ := s.typ(inf.Sig); typ != inf.Sig {
-			inf.Sig = typ.(*Signature)
-			changed = true
-		}
-		if changed {
-			info.Inferred[e] = inf
-		}
-	}
-
-	for _, obj := range info.Defs {
-		if obj != nil {
-			if typ := s.typ(obj.Type()); typ != obj.Type() {
-				obj.setType(typ)
-			}
-		}
-	}
-
-	for _, obj := range info.Uses {
-		if obj != nil {
-			if typ := s.typ(obj.Type()); typ != obj.Type() {
-				obj.setType(typ)
-			}
-		}
-	}
-
-	// TODO(gri) sanitize as needed
-	// - info.Implicits
-	// - info.Selections
-	// - info.Scopes
-	// - info.InitOrder
-}
-
-type sanitizer map[Type]Type
-
-func (s sanitizer) typ(typ Type) Type {
-	if typ == nil {
-		return nil
-	}
-
-	if t, found := s[typ]; found {
-		return t
-	}
-	s[typ] = typ
-
-	switch t := typ.(type) {
-	case *Basic, *bottom, *top:
-		// nothing to do
-
-	case *Array:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Slice:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Struct:
-		s.varList(t.fields)
-
-	case *Pointer:
-		if base := s.typ(t.base); base != t.base {
-			t.base = base
-		}
-
-	case *Tuple:
-		s.tuple(t)
-
-	case *Signature:
-		s.var_(t.recv)
-		s.tuple(t.params)
-		s.tuple(t.results)
-
-	case *Sum:
-		s.typeList(t.types)
-
-	case *Interface:
-		s.funcList(t.methods)
-		if types := s.typ(t.types); types != t.types {
-			t.types = types
-		}
-		s.typeList(t.embeddeds)
-		s.funcList(t.allMethods)
-		if allTypes := s.typ(t.allTypes); allTypes != t.allTypes {
-			t.allTypes = allTypes
-		}
-
-	case *Map:
-		if key := s.typ(t.key); key != t.key {
-			t.key = key
-		}
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Chan:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Named:
-		if orig := s.typ(t.fromRHS); orig != t.fromRHS {
-			t.fromRHS = orig
-		}
-		if under := s.typ(t.underlying); under != t.underlying {
-			t.underlying = under
-		}
-		s.typeList(t.targs)
-		s.funcList(t.methods)
-
-	case *TypeParam:
-		if bound := s.typ(t.bound); bound != t.bound {
-			t.bound = bound
-		}
-
-	case *instance:
-		typ = t.expand()
-		s[t] = typ
-
-	default:
-		panic("unimplemented")
-	}
-
-	return typ
-}
-
-func (s sanitizer) var_(v *Var) {
-	if v != nil {
-		if typ := s.typ(v.typ); typ != v.typ {
-			v.typ = typ
-		}
-	}
-}
-
-func (s sanitizer) varList(list []*Var) {
-	for _, v := range list {
-		s.var_(v)
-	}
-}
-
-func (s sanitizer) tuple(t *Tuple) {
-	if t != nil {
-		s.varList(t.vars)
-	}
-}
-
-func (s sanitizer) func_(f *Func) {
-	if f != nil {
-		if typ := s.typ(f.typ); typ != f.typ {
-			f.typ = typ
-		}
-	}
-}
-
-func (s sanitizer) funcList(list []*Func) {
-	for _, f := range list {
-		s.func_(f)
-	}
-}
-
-func (s sanitizer) typeList(list []Type) {
-	for i, t := range list {
-		if typ := s.typ(t); typ != t {
-			list[i] = typ
-		}
-	}
-}
diff --git a/src/cmd/compile/internal/types2/scope.go b/src/cmd/compile/internal/types2/scope.go
index ade0a79b31d..095875d94b0 100644
--- a/src/cmd/compile/internal/types2/scope.go
+++ b/src/cmd/compile/internal/types2/scope.go
@@ -13,6 +13,7 @@ import (
 	"io"
 	"sort"
 	"strings"
+	"sync"
 )
 
 // A Scope maintains a set of objects and links to its containing
@@ -22,6 +23,7 @@ import (
 type Scope struct {
 	parent   *Scope
 	children []*Scope
+	number   int               // parent.children[number-1] is this scope; 0 if there is no parent
 	elems    map[string]Object // lazily allocated
 	pos, end syntax.Pos        // scope extent; may be invalid
 	comment  string            // for debugging only
@@ -31,10 +33,11 @@ type Scope struct {
 // NewScope returns a new, empty scope contained in the given parent
 // scope, if any. The comment is for debugging only.
 func NewScope(parent *Scope, pos, end syntax.Pos, comment string) *Scope {
-	s := &Scope{parent, nil, nil, pos, end, comment, false}
+	s := &Scope{parent, nil, 0, nil, pos, end, comment, false}
 	// don't add children to Universe scope!
 	if parent != nil && parent != Universe {
 		parent.children = append(parent.children, s)
+		s.number = len(parent.children)
 	}
 	return s
 }
@@ -66,7 +69,7 @@ func (s *Scope) Child(i int) *Scope { return s.children[i] }
 // Lookup returns the object in scope s with the given name if such an
 // object exists; otherwise the result is nil.
 func (s *Scope) Lookup(name string) Object {
-	return s.elems[name]
+	return resolve(name, s.elems[name])
 }
 
 // LookupParent follows the parent chain of scopes starting with s until
@@ -81,7 +84,7 @@ func (s *Scope) Lookup(name string) Object {
 // whose scope is the scope of the package that exported them.
 func (s *Scope) LookupParent(name string, pos syntax.Pos) (*Scope, Object) {
 	for ; s != nil; s = s.parent {
-		if obj := s.elems[name]; obj != nil && (!pos.IsKnown() || obj.scopePos().Cmp(pos) <= 0) {
+		if obj := s.Lookup(name); obj != nil && (!pos.IsKnown() || obj.scopePos().Cmp(pos) <= 0) {
 			return s, obj
 		}
 	}
@@ -95,19 +98,38 @@ func (s *Scope) LookupParent(name string, pos syntax.Pos) (*Scope, Object) {
 // if not already set, and returns nil.
 func (s *Scope) Insert(obj Object) Object {
 	name := obj.Name()
-	if alt := s.elems[name]; alt != nil {
+	if alt := s.Lookup(name); alt != nil {
 		return alt
 	}
-	if s.elems == nil {
-		s.elems = make(map[string]Object)
-	}
-	s.elems[name] = obj
+	s.insert(name, obj)
 	if obj.Parent() == nil {
 		obj.setParent(s)
 	}
 	return nil
 }
 
+// InsertLazy is like Insert, but allows deferring construction of the
+// inserted object until it's accessed with Lookup. The Object
+// returned by resolve must have the same name as given to InsertLazy.
+// If s already contains an alternative object with the same name,
+// InsertLazy leaves s unchanged and returns false. Otherwise it
+// records the binding and returns true. The object's parent scope
+// will be set to s after resolve is called.
+func (s *Scope) InsertLazy(name string, resolve func() Object) bool {
+	if s.elems[name] != nil {
+		return false
+	}
+	s.insert(name, &lazyObject{parent: s, resolve: resolve})
+	return true
+}
+
+func (s *Scope) insert(name string, obj Object) {
+	if s.elems == nil {
+		s.elems = make(map[string]Object)
+	}
+	s.elems[name] = obj
+}
+
 // Squash merges s with its parent scope p by adding all
 // objects of s to p, adding all children of s to the
 // children of p, and removing s from p's children.
@@ -117,7 +139,8 @@ func (s *Scope) Insert(obj Object) Object {
 func (s *Scope) Squash(err func(obj, alt Object)) {
 	p := s.parent
 	assert(p != nil)
-	for _, obj := range s.elems {
+	for name, obj := range s.elems {
+		obj = resolve(name, obj)
 		obj.setParent(nil)
 		if alt := p.Insert(obj); alt != nil {
 			err(obj, alt)
@@ -196,7 +219,7 @@ func (s *Scope) WriteTo(w io.Writer, n int, recurse bool) {
 
 	indn1 := indn + ind
 	for _, name := range s.Names() {
-		fmt.Fprintf(w, "%s%s\n", indn1, s.elems[name])
+		fmt.Fprintf(w, "%s%s\n", indn1, s.Lookup(name))
 	}
 
 	if recurse {
@@ -214,3 +237,57 @@ func (s *Scope) String() string {
 	s.WriteTo(&buf, 0, false)
 	return buf.String()
 }
+
+// A lazyObject represents an imported Object that has not been fully
+// resolved yet by its importer.
+type lazyObject struct {
+	parent  *Scope
+	resolve func() Object
+	obj     Object
+	once    sync.Once
+}
+
+// resolve returns the Object represented by obj, resolving lazy
+// objects as appropriate.
+func resolve(name string, obj Object) Object {
+	if lazy, ok := obj.(*lazyObject); ok {
+		lazy.once.Do(func() {
+			obj := lazy.resolve()
+
+			if _, ok := obj.(*lazyObject); ok {
+				panic("recursive lazy object")
+			}
+			if obj.Name() != name {
+				panic("lazy object has unexpected name")
+			}
+
+			if obj.Parent() == nil {
+				obj.setParent(lazy.parent)
+			}
+			lazy.obj = obj
+		})
+
+		obj = lazy.obj
+	}
+	return obj
+}
+
+// stub implementations so *lazyObject implements Object and we can
+// store them directly into Scope.elems.
+func (*lazyObject) Parent() *Scope                        { panic("unreachable") }
+func (*lazyObject) Pos() syntax.Pos                       { panic("unreachable") }
+func (*lazyObject) Pkg() *Package                         { panic("unreachable") }
+func (*lazyObject) Name() string                          { panic("unreachable") }
+func (*lazyObject) Type() Type                            { panic("unreachable") }
+func (*lazyObject) Exported() bool                        { panic("unreachable") }
+func (*lazyObject) Id() string                            { panic("unreachable") }
+func (*lazyObject) String() string                        { panic("unreachable") }
+func (*lazyObject) order() uint32                         { panic("unreachable") }
+func (*lazyObject) color() color                          { panic("unreachable") }
+func (*lazyObject) setType(Type)                          { panic("unreachable") }
+func (*lazyObject) setOrder(uint32)                       { panic("unreachable") }
+func (*lazyObject) setColor(color color)                  { panic("unreachable") }
+func (*lazyObject) setParent(*Scope)                      { panic("unreachable") }
+func (*lazyObject) sameId(pkg *Package, name string) bool { panic("unreachable") }
+func (*lazyObject) scopePos() syntax.Pos                  { panic("unreachable") }
+func (*lazyObject) setScopePos(pos syntax.Pos)            { panic("unreachable") }
diff --git a/src/cmd/compile/internal/types2/signature.go b/src/cmd/compile/internal/types2/signature.go
new file mode 100644
index 00000000000..e319e652112
--- /dev/null
+++ b/src/cmd/compile/internal/types2/signature.go
@@ -0,0 +1,393 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"cmd/compile/internal/syntax"
+	"fmt"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Signature represents a (non-builtin) function or method type.
+// The receiver is ignored when comparing signatures for identity.
+type Signature struct {
+	// We need to keep the scope in Signature (rather than passing it around
+	// and store it in the Func Object) because when type-checking a function
+	// literal we call the general type checker which returns a general Type.
+	// We then unpack the *Signature and use the scope for the literal body.
+	rparams  *TParamList // receiver type parameters from left to right, or nil
+	tparams  *TParamList // type parameters from left to right, or nil
+	scope    *Scope      // function scope, present for package-local signatures
+	recv     *Var        // nil if not a method
+	params   *Tuple      // (incoming) parameters from left to right; or nil
+	results  *Tuple      // (outgoing) results from left to right; or nil
+	variadic bool        // true if the last parameter's type is of the form ...T (or string, for append built-in only)
+}
+
+// NewSignature returns a new function type for the given receiver, parameters,
+// and results, either of which may be nil. If variadic is set, the function
+// is variadic, it must have at least one parameter, and the last parameter
+// must be of unnamed slice type.
+func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature {
+	if variadic {
+		n := params.Len()
+		if n == 0 {
+			panic("variadic function must have at least one parameter")
+		}
+		if _, ok := params.At(n - 1).typ.(*Slice); !ok {
+			panic("variadic parameter must be of unnamed slice type")
+		}
+	}
+	return &Signature{recv: recv, params: params, results: results, variadic: variadic}
+}
+
+// Recv returns the receiver of signature s (if a method), or nil if a
+// function. It is ignored when comparing signatures for identity.
+//
+// For an abstract method, Recv returns the enclosing interface either
+// as a *Named or an *Interface. Due to embedding, an interface may
+// contain methods whose receiver type is a different interface.
+func (s *Signature) Recv() *Var { return s.recv }
+
+// TParams returns the type parameters of signature s, or nil.
+func (s *Signature) TParams() *TParamList { return s.tparams }
+
+// SetTParams sets the type parameters of signature s.
+func (s *Signature) SetTParams(tparams []*TypeName) { s.tparams = bindTParams(tparams) }
+
+// RParams returns the receiver type parameters of signature s, or nil.
+func (s *Signature) RParams() *TParamList { return s.rparams }
+
+// SetRParams sets the receiver type params of signature s.
+func (s *Signature) SetRParams(rparams []*TypeName) { s.rparams = bindTParams(rparams) }
+
+// Params returns the parameters of signature s, or nil.
+func (s *Signature) Params() *Tuple { return s.params }
+
+// Results returns the results of signature s, or nil.
+func (s *Signature) Results() *Tuple { return s.results }
+
+// Variadic reports whether the signature s is variadic.
+func (s *Signature) Variadic() bool { return s.variadic }
+
+func (s *Signature) Underlying() Type { return s }
+func (s *Signature) String() string   { return TypeString(s, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// Disabled by default, but enabled when running tests (via types_test.go).
+var acceptMethodTypeParams bool
+
+// funcType type-checks a function or method type.
+func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []*syntax.Field, ftyp *syntax.FuncType) {
+	check.openScope(ftyp, "function")
+	check.scope.isFunc = true
+	check.recordScope(ftyp, check.scope)
+	sig.scope = check.scope
+	defer check.closeScope()
+
+	var recvTyp syntax.Expr // rewritten receiver type; valid if != nil
+	if recvPar != nil {
+		// collect generic receiver type parameters, if any
+		// - a receiver type parameter is like any other type parameter, except that it is declared implicitly
+		// - the receiver specification acts as local declaration for its type parameters, which may be blank
+		_, rname, rparams := check.unpackRecv(recvPar.Type, true)
+		if len(rparams) > 0 {
+			// Blank identifiers don't get declared and regular type-checking of the instantiated
+			// parameterized receiver type expression fails in Checker.collectParams of receiver.
+			// Identify blank type parameters and substitute each with a unique new identifier named
+			// "n_" (where n is the parameter index) and which cannot conflict with any user-defined
+			// name.
+			var smap map[*syntax.Name]*syntax.Name // substitution map from "_" to "!n" identifiers
+			for i, p := range rparams {
+				if p.Value == "_" {
+					new := *p
+					new.Value = fmt.Sprintf("%d_", i)
+					rparams[i] = &new // use n_ identifier instead of _ so it can be looked up
+					if smap == nil {
+						smap = make(map[*syntax.Name]*syntax.Name)
+					}
+					smap[p] = &new
+				}
+			}
+			if smap != nil {
+				// blank identifiers were found => use rewritten receiver type
+				recvTyp = isubst(recvPar.Type, smap)
+			}
+			rlist := make([]*TypeName, len(rparams))
+			for i, rparam := range rparams {
+				rlist[i] = check.declareTypeParam(rparam)
+			}
+			sig.rparams = bindTParams(rlist)
+			// determine receiver type to get its type parameters
+			// and the respective type parameter bounds
+			var recvTParams []*TypeName
+			if rname != nil {
+				// recv should be a Named type (otherwise an error is reported elsewhere)
+				// Also: Don't report an error via genericType since it will be reported
+				//       again when we type-check the signature.
+				// TODO(gri) maybe the receiver should be marked as invalid instead?
+				if recv := asNamed(check.genericType(rname, false)); recv != nil {
+					recvTParams = recv.TParams().list()
+				}
+			}
+			// provide type parameter bounds
+			// - only do this if we have the right number (otherwise an error is reported elsewhere)
+			if sig.RParams().Len() == len(recvTParams) {
+				// We have a list of *TypeNames but we need a list of Types.
+				list := make([]Type, sig.RParams().Len())
+				for i, t := range sig.RParams().list() {
+					list[i] = t.typ
+				}
+				smap := makeSubstMap(recvTParams, list)
+				for i, tname := range sig.RParams().list() {
+					bound := recvTParams[i].typ.(*TypeParam).bound
+					// bound is (possibly) parameterized in the context of the
+					// receiver type declaration. Substitute parameters for the
+					// current context.
+					// TODO(gri) should we assume now that bounds always exist?
+					//           (no bound == empty interface)
+					if bound != nil {
+						bound = check.subst(tname.pos, bound, smap, nil)
+						tname.typ.(*TypeParam).bound = bound
+					}
+				}
+			}
+		}
+	}
+
+	if tparams != nil {
+		sig.tparams = check.collectTypeParams(tparams)
+		// Always type-check method type parameters but complain if they are not enabled.
+		// (A separate check is needed when type-checking interface method signatures because
+		// they don't have a receiver specification.)
+		if recvPar != nil && !acceptMethodTypeParams {
+			check.error(ftyp, "methods cannot have type parameters")
+		}
+	}
+
+	// Value (non-type) parameters' scope starts in the function body. Use a temporary scope for their
+	// declarations and then squash that scope into the parent scope (and report any redeclarations at
+	// that time).
+	scope := NewScope(check.scope, nopos, nopos, "function body (temp. scope)")
+	var recvList []*Var // TODO(gri) remove the need for making a list here
+	if recvPar != nil {
+		recvList, _ = check.collectParams(scope, []*syntax.Field{recvPar}, recvTyp, false) // use rewritten receiver type, if any
+	}
+	params, variadic := check.collectParams(scope, ftyp.ParamList, nil, true)
+	results, _ := check.collectParams(scope, ftyp.ResultList, nil, false)
+	scope.Squash(func(obj, alt Object) {
+		var err error_
+		err.errorf(obj, "%s redeclared in this block", obj.Name())
+		err.recordAltDecl(alt)
+		check.report(&err)
+	})
+
+	if recvPar != nil {
+		// recv parameter list present (may be empty)
+		// spec: "The receiver is specified via an extra parameter section preceding the
+		// method name. That parameter section must declare a single parameter, the receiver."
+		var recv *Var
+		switch len(recvList) {
+		case 0:
+			// error reported by resolver
+			recv = NewParam(nopos, nil, "", Typ[Invalid]) // ignore recv below
+		default:
+			// more than one receiver
+			check.error(recvList[len(recvList)-1].Pos(), "method must have exactly one receiver")
+			fallthrough // continue with first receiver
+		case 1:
+			recv = recvList[0]
+		}
+
+		// TODO(gri) We should delay rtyp expansion to when we actually need the
+		//           receiver; thus all checks here should be delayed to later.
+		rtyp, _ := deref(recv.typ)
+
+		// spec: "The receiver type must be of the form T or *T where T is a type name."
+		// (ignore invalid types - error was reported before)
+		if rtyp != Typ[Invalid] {
+			var err string
+			switch T := rtyp.(type) {
+			case *Named:
+				T.expand(nil)
+				// spec: "The type denoted by T is called the receiver base type; it must not
+				// be a pointer or interface type and it must be declared in the same package
+				// as the method."
+				if T.obj.pkg != check.pkg {
+					err = "type not defined in this package"
+					if check.conf.CompilerErrorMessages {
+						check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
+						err = ""
+					}
+				} else {
+					// The underlying type of a receiver base type can be a type parameter;
+					// e.g. for methods with a generic receiver T[P] with type T[P any] P.
+					underIs(T, func(u Type) bool {
+						switch u := u.(type) {
+						case *Basic:
+							// unsafe.Pointer is treated like a regular pointer
+							if u.kind == UnsafePointer {
+								err = "unsafe.Pointer"
+								return false
+							}
+						case *Pointer, *Interface:
+							err = "pointer or interface type"
+							return false
+						}
+						return true
+					})
+				}
+			case *Basic:
+				err = "basic or unnamed type"
+				if check.conf.CompilerErrorMessages {
+					check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
+					err = ""
+				}
+			default:
+				check.errorf(recv.pos, "invalid receiver type %s", recv.typ)
+			}
+			if err != "" {
+				check.errorf(recv.pos, "invalid receiver type %s (%s)", recv.typ, err)
+				// ok to continue
+			}
+		}
+		sig.recv = recv
+	}
+
+	sig.params = NewTuple(params...)
+	sig.results = NewTuple(results...)
+	sig.variadic = variadic
+}
+
+// collectParams declares the parameters of list in scope and returns the corresponding
+// variable list. If type0 != nil, it is used instead of the first type in list.
+func (check *Checker) collectParams(scope *Scope, list []*syntax.Field, type0 syntax.Expr, variadicOk bool) (params []*Var, variadic bool) {
+	if list == nil {
+		return
+	}
+
+	var named, anonymous bool
+
+	var typ Type
+	var prev syntax.Expr
+	for i, field := range list {
+		ftype := field.Type
+		// type-check type of grouped fields only once
+		if ftype != prev {
+			prev = ftype
+			if i == 0 && type0 != nil {
+				ftype = type0
+			}
+			if t, _ := ftype.(*syntax.DotsType); t != nil {
+				ftype = t.Elem
+				if variadicOk && i == len(list)-1 {
+					variadic = true
+				} else {
+					check.softErrorf(t, "can only use ... with final parameter in list")
+					// ignore ... and continue
+				}
+			}
+			typ = check.varType(ftype)
+		}
+		// The parser ensures that f.Tag is nil and we don't
+		// care if a constructed AST contains a non-nil tag.
+		if field.Name != nil {
+			// named parameter
+			name := field.Name.Value
+			if name == "" {
+				check.error(field.Name, invalidAST+"anonymous parameter")
+				// ok to continue
+			}
+			par := NewParam(field.Name.Pos(), check.pkg, name, typ)
+			check.declare(scope, field.Name, par, scope.pos)
+			params = append(params, par)
+			named = true
+		} else {
+			// anonymous parameter
+			par := NewParam(field.Pos(), check.pkg, "", typ)
+			check.recordImplicit(field, par)
+			params = append(params, par)
+			anonymous = true
+		}
+	}
+
+	if named && anonymous {
+		check.error(list[0], invalidAST+"list contains both named and anonymous parameters")
+		// ok to continue
+	}
+
+	// For a variadic function, change the last parameter's type from T to []T.
+	// Since we type-checked T rather than ...T, we also need to retro-actively
+	// record the type for ...T.
+	if variadic {
+		last := params[len(params)-1]
+		last.typ = &Slice{elem: last.typ}
+		check.recordTypeAndValue(list[len(list)-1].Type, typexpr, last.typ, nil)
+	}
+
+	return
+}
+
+// isubst returns an x with identifiers substituted per the substitution map smap.
+// isubst only handles the case of (valid) method receiver type expressions correctly.
+func isubst(x syntax.Expr, smap map[*syntax.Name]*syntax.Name) syntax.Expr {
+	switch n := x.(type) {
+	case *syntax.Name:
+		if alt := smap[n]; alt != nil {
+			return alt
+		}
+	// case *syntax.StarExpr:
+	// 	X := isubst(n.X, smap)
+	// 	if X != n.X {
+	// 		new := *n
+	// 		new.X = X
+	// 		return &new
+	// 	}
+	case *syntax.Operation:
+		if n.Op == syntax.Mul && n.Y == nil {
+			X := isubst(n.X, smap)
+			if X != n.X {
+				new := *n
+				new.X = X
+				return &new
+			}
+		}
+	case *syntax.IndexExpr:
+		Index := isubst(n.Index, smap)
+		if Index != n.Index {
+			new := *n
+			new.Index = Index
+			return &new
+		}
+	case *syntax.ListExpr:
+		var elems []syntax.Expr
+		for i, elem := range n.ElemList {
+			new := isubst(elem, smap)
+			if new != elem {
+				if elems == nil {
+					elems = make([]syntax.Expr, len(n.ElemList))
+					copy(elems, n.ElemList)
+				}
+				elems[i] = new
+			}
+		}
+		if elems != nil {
+			new := *n
+			new.ElemList = elems
+			return &new
+		}
+	case *syntax.ParenExpr:
+		return isubst(n.X, smap) // no need to keep parentheses
+	default:
+		// Other receiver type expressions are invalid.
+		// It's fine to ignore those here as they will
+		// be checked elsewhere.
+	}
+	return x
+}
diff --git a/src/cmd/compile/internal/types2/sizeof_test.go b/src/cmd/compile/internal/types2/sizeof_test.go
index 236feb0404e..d2f53258f03 100644
--- a/src/cmd/compile/internal/types2/sizeof_test.go
+++ b/src/cmd/compile/internal/types2/sizeof_test.go
@@ -26,15 +26,14 @@ func TestSizeof(t *testing.T) {
 		{Struct{}, 24, 48},
 		{Pointer{}, 8, 16},
 		{Tuple{}, 12, 24},
-		{Signature{}, 44, 88},
-		{Sum{}, 12, 24},
-		{Interface{}, 60, 120},
+		{Signature{}, 28, 56},
+		{Union{}, 16, 32},
+		{Interface{}, 40, 80},
 		{Map{}, 16, 32},
 		{Chan{}, 12, 24},
-		{Named{}, 68, 136},
+		{Named{}, 80, 152},
 		{TypeParam{}, 28, 48},
-		{instance{}, 52, 96},
-		{bottom{}, 0, 0},
+		{term{}, 12, 24},
 		{top{}, 0, 0},
 
 		// Objects
@@ -48,8 +47,9 @@ func TestSizeof(t *testing.T) {
 		{Nil{}, 56, 88},
 
 		// Misc
-		{Scope{}, 56, 96},
+		{Scope{}, 60, 104},
 		{Package{}, 40, 80},
+		{TypeSet{}, 28, 56},
 	}
 
 	for _, test := range tests {
diff --git a/src/cmd/compile/internal/types2/sizes.go b/src/cmd/compile/internal/types2/sizes.go
index aa0fbf40fce..6a3d19d8eaf 100644
--- a/src/cmd/compile/internal/types2/sizes.go
+++ b/src/cmd/compile/internal/types2/sizes.go
@@ -48,7 +48,7 @@ type StdSizes struct {
 func (s *StdSizes) Alignof(T Type) int64 {
 	// For arrays and structs, alignment is defined in terms
 	// of alignment of the elements and fields, respectively.
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Array:
 		// spec: "For a variable x of array type: unsafe.Alignof(x)
 		// is the same as unsafe.Alignof(x[0]), but at least 1."
@@ -73,6 +73,8 @@ func (s *StdSizes) Alignof(T Type) int64 {
 		if t.Info()&IsString != 0 {
 			return s.WordSize
 		}
+	case *TypeParam, *Union:
+		unreachable()
 	}
 	a := s.Sizeof(T) // may be 0
 	// spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1."
@@ -118,7 +120,7 @@ var basicSizes = [...]byte{
 }
 
 func (s *StdSizes) Sizeof(T Type) int64 {
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Basic:
 		assert(isTyped(T))
 		k := t.kind
@@ -148,10 +150,10 @@ func (s *StdSizes) Sizeof(T Type) int64 {
 		}
 		offsets := s.Offsetsof(t.fields)
 		return offsets[n-1] + s.Sizeof(t.fields[n-1].typ)
-	case *Sum:
-		panic("Sizeof unimplemented for type sum")
 	case *Interface:
 		return s.WordSize * 2
+	case *TypeParam, *Union:
+		unreachable()
 	}
 	return s.WordSize // catch-all
 }
diff --git a/src/cmd/compile/internal/types2/slice.go b/src/cmd/compile/internal/types2/slice.go
new file mode 100644
index 00000000000..9c22a6fb1b6
--- /dev/null
+++ b/src/cmd/compile/internal/types2/slice.go
@@ -0,0 +1,19 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A Slice represents a slice type.
+type Slice struct {
+	elem Type
+}
+
+// NewSlice returns a new slice type for the given element type.
+func NewSlice(elem Type) *Slice { return &Slice{elem: elem} }
+
+// Elem returns the element type of slice s.
+func (s *Slice) Elem() Type { return s.elem }
+
+func (s *Slice) Underlying() Type { return s }
+func (s *Slice) String() string   { return TypeString(s, nil) }
diff --git a/src/cmd/compile/internal/types2/stmt.go b/src/cmd/compile/internal/types2/stmt.go
index c3e646c80c1..7865c2d4f45 100644
--- a/src/cmd/compile/internal/types2/stmt.go
+++ b/src/cmd/compile/internal/types2/stmt.go
@@ -14,7 +14,7 @@ import (
 
 func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body *syntax.BlockStmt, iota constant.Value) {
 	if check.conf.IgnoreFuncBodies {
-		panic("internal error: function body not ignored")
+		panic("function body not ignored")
 	}
 
 	if check.conf.Trace {
@@ -64,7 +64,8 @@ func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body
 
 func (check *Checker) usage(scope *Scope) {
 	var unused []*Var
-	for _, elem := range scope.elems {
+	for name, elem := range scope.elems {
+		elem = resolve(name, elem)
 		if v, _ := elem.(*Var); v != nil && !v.used {
 			unused = append(unused, v)
 		}
@@ -255,7 +256,7 @@ L:
 			// look for duplicate types for a given value
 			// (quadratic algorithm, but these lists tend to be very short)
 			for _, vt := range seen[val] {
-				if check.identical(v.typ, vt.typ) {
+				if Identical(v.typ, vt.typ) {
 					var err error_
 					err.errorf(&v, "duplicate case %s in expression switch", &v)
 					err.errorf(vt.pos, "previous case")
@@ -281,7 +282,7 @@ L:
 		// look for duplicate types
 		// (quadratic algorithm, but type switches tend to be reasonably small)
 		for t, other := range seen {
-			if T == nil && t == nil || T != nil && t != nil && check.identical(T, t) {
+			if T == nil && t == nil || T != nil && t != nil && Identical(T, t) {
 				// talk about "case" rather than "type" because of nil case
 				Ts := "nil"
 				if T != nil {
@@ -351,25 +352,33 @@ func (check *Checker) stmt(ctxt stmtContext, s syntax.Stmt) {
 		check.errorf(&x, "%s %s", &x, msg)
 
 	case *syntax.SendStmt:
-		var ch, x operand
+		var ch, val operand
 		check.expr(&ch, s.Chan)
-		check.expr(&x, s.Value)
-		if ch.mode == invalid || x.mode == invalid {
+		check.expr(&val, s.Value)
+		if ch.mode == invalid || val.mode == invalid {
 			return
 		}
-
-		tch := asChan(ch.typ)
-		if tch == nil {
-			check.errorf(s, invalidOp+"cannot send to non-chan type %s", ch.typ)
+		var elem Type
+		if !underIs(ch.typ, func(u Type) bool {
+			uch, _ := u.(*Chan)
+			if uch == nil {
+				check.errorf(s, invalidOp+"cannot send to non-channel %s", &ch)
+				return false
+			}
+			if uch.dir == RecvOnly {
+				check.errorf(s, invalidOp+"cannot send to receive-only channel %s", &ch)
+				return false
+			}
+			if elem != nil && !Identical(uch.elem, elem) {
+				check.errorf(s, invalidOp+"channels of %s must have the same element type", &ch)
+				return false
+			}
+			elem = uch.elem
+			return true
+		}) {
 			return
 		}
-
-		if tch.dir == RecvOnly {
-			check.errorf(s, invalidOp+"cannot send to receive-only type %s", tch)
-			return
-		}
-
-		check.assignment(&x, tch.elem, "send")
+		check.assignment(&val, elem, "send")
 
 	case *syntax.AssignStmt:
 		lhs := unpackExpr(s.Lhs)
@@ -780,9 +789,9 @@ func (check *Checker) rangeStmt(inner stmtContext, s *syntax.ForStmt, rclause *s
 	// determine key/value types
 	var key, val Type
 	if x.mode != invalid {
+		// Ranging over a type parameter is permitted if it has a structural type.
 		typ := optype(x.typ)
 		if _, ok := typ.(*Chan); ok && sValue != nil {
-			// TODO(gri) this also needs to happen for channels in generic variables
 			check.softErrorf(sValue, "range over %s permits only one iteration variable", &x)
 			// ok to continue
 		}
@@ -891,7 +900,7 @@ func isVarName(x syntax.Expr) bool {
 // variables are used or present; this matters if we range over a generic
 // type where not all keys or values are of the same type.
 func rangeKeyVal(typ Type, wantKey, wantVal bool) (Type, Type, string) {
-	switch typ := typ.(type) {
+	switch typ := arrayPtrDeref(typ).(type) {
 	case *Basic:
 		if isString(typ) {
 			return Typ[Int], universeRune, "" // use 'rune' name
@@ -900,10 +909,6 @@ func rangeKeyVal(typ Type, wantKey, wantVal bool) (Type, Type, string) {
 		return Typ[Int], typ.elem, ""
 	case *Slice:
 		return Typ[Int], typ.elem, ""
-	case *Pointer:
-		if typ := asArray(typ.base); typ != nil {
-			return Typ[Int], typ.elem, ""
-		}
 	case *Map:
 		return typ.key, typ.elem, ""
 	case *Chan:
@@ -912,32 +917,9 @@ func rangeKeyVal(typ Type, wantKey, wantVal bool) (Type, Type, string) {
 			msg = "receive from send-only channel"
 		}
 		return typ.elem, Typ[Invalid], msg
-	case *Sum:
-		first := true
-		var key, val Type
-		var msg string
-		typ.is(func(t Type) bool {
-			k, v, m := rangeKeyVal(under(t), wantKey, wantVal)
-			if k == nil || m != "" {
-				key, val, msg = k, v, m
-				return false
-			}
-			if first {
-				key, val, msg = k, v, m
-				first = false
-				return true
-			}
-			if wantKey && !Identical(key, k) {
-				key, val, msg = nil, nil, "all possible values must have the same key type"
-				return false
-			}
-			if wantVal && !Identical(val, v) {
-				key, val, msg = nil, nil, "all possible values must have the same element type"
-				return false
-			}
-			return true
-		})
-		return key, val, msg
+	case *top:
+		// we have a type parameter with no structural type
+		return nil, nil, "no structural type"
 	}
 	return nil, nil, ""
 }
diff --git a/src/cmd/compile/internal/types2/struct.go b/src/cmd/compile/internal/types2/struct.go
new file mode 100644
index 00000000000..f0c27c01504
--- /dev/null
+++ b/src/cmd/compile/internal/types2/struct.go
@@ -0,0 +1,213 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"cmd/compile/internal/syntax"
+	"strconv"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Struct represents a struct type.
+type Struct struct {
+	fields []*Var
+	tags   []string // field tags; nil if there are no tags
+}
+
+// NewStruct returns a new struct with the given fields and corresponding field tags.
+// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be
+// only as long as required to hold the tag with the largest index i. Consequently,
+// if no field has a tag, tags may be nil.
+func NewStruct(fields []*Var, tags []string) *Struct {
+	var fset objset
+	for _, f := range fields {
+		if f.name != "_" && fset.insert(f) != nil {
+			panic("multiple fields with the same name")
+		}
+	}
+	if len(tags) > len(fields) {
+		panic("more tags than fields")
+	}
+	return &Struct{fields: fields, tags: tags}
+}
+
+// NumFields returns the number of fields in the struct (including blank and embedded fields).
+func (s *Struct) NumFields() int { return len(s.fields) }
+
+// Field returns the i'th field for 0 <= i < NumFields().
+func (s *Struct) Field(i int) *Var { return s.fields[i] }
+
+// Tag returns the i'th field tag for 0 <= i < NumFields().
+func (s *Struct) Tag(i int) string {
+	if i < len(s.tags) {
+		return s.tags[i]
+	}
+	return ""
+}
+
+func (s *Struct) Underlying() Type { return s }
+func (s *Struct) String() string   { return TypeString(s, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (check *Checker) structType(styp *Struct, e *syntax.StructType) {
+	if e.FieldList == nil {
+		return
+	}
+
+	// struct fields and tags
+	var fields []*Var
+	var tags []string
+
+	// for double-declaration checks
+	var fset objset
+
+	// current field typ and tag
+	var typ Type
+	var tag string
+	add := func(ident *syntax.Name, embedded bool, pos syntax.Pos) {
+		if tag != "" && tags == nil {
+			tags = make([]string, len(fields))
+		}
+		if tags != nil {
+			tags = append(tags, tag)
+		}
+
+		name := ident.Value
+		fld := NewField(pos, check.pkg, name, typ, embedded)
+		// spec: "Within a struct, non-blank field names must be unique."
+		if name == "_" || check.declareInSet(&fset, pos, fld) {
+			fields = append(fields, fld)
+			check.recordDef(ident, fld)
+		}
+	}
+
+	// addInvalid adds an embedded field of invalid type to the struct for
+	// fields with errors; this keeps the number of struct fields in sync
+	// with the source as long as the fields are _ or have different names
+	// (issue #25627).
+	addInvalid := func(ident *syntax.Name, pos syntax.Pos) {
+		typ = Typ[Invalid]
+		tag = ""
+		add(ident, true, pos)
+	}
+
+	var prev syntax.Expr
+	for i, f := range e.FieldList {
+		// Fields declared syntactically with the same type (e.g.: a, b, c T)
+		// share the same type expression. Only check type if it's a new type.
+		if i == 0 || f.Type != prev {
+			typ = check.varType(f.Type)
+			prev = f.Type
+		}
+		tag = ""
+		if i < len(e.TagList) {
+			tag = check.tag(e.TagList[i])
+		}
+		if f.Name != nil {
+			// named field
+			add(f.Name, false, f.Name.Pos())
+		} else {
+			// embedded field
+			// spec: "An embedded type must be specified as a type name T or as a
+			// pointer to a non-interface type name *T, and T itself may not be a
+			// pointer type."
+			pos := syntax.StartPos(f.Type)
+			name := embeddedFieldIdent(f.Type)
+			if name == nil {
+				check.errorf(pos, "invalid embedded field type %s", f.Type)
+				name = &syntax.Name{Value: "_"} // TODO(gri) need to set position to pos
+				addInvalid(name, pos)
+				continue
+			}
+			add(name, true, pos)
+
+			// Because we have a name, typ must be of the form T or *T, where T is the name
+			// of a (named or alias) type, and t (= deref(typ)) must be the type of T.
+			// We must delay this check to the end because we don't want to instantiate
+			// (via under(t)) a possibly incomplete type.
+			embeddedTyp := typ // for closure below
+			embeddedPos := pos
+			check.later(func() {
+				t, isPtr := deref(embeddedTyp)
+				switch t := under(t).(type) {
+				case *Basic:
+					if t == Typ[Invalid] {
+						// error was reported before
+						return
+					}
+					// unsafe.Pointer is treated like a regular pointer
+					if t.kind == UnsafePointer {
+						check.error(embeddedPos, "embedded field type cannot be unsafe.Pointer")
+					}
+				case *Pointer:
+					check.error(embeddedPos, "embedded field type cannot be a pointer")
+				case *TypeParam:
+					check.error(embeddedPos, "embedded field type cannot be a (pointer to a) type parameter")
+				case *Interface:
+					if isPtr {
+						check.error(embeddedPos, "embedded field type cannot be a pointer to an interface")
+					}
+				}
+			})
+		}
+	}
+
+	styp.fields = fields
+	styp.tags = tags
+}
+
+func embeddedFieldIdent(e syntax.Expr) *syntax.Name {
+	switch e := e.(type) {
+	case *syntax.Name:
+		return e
+	case *syntax.Operation:
+		if base := ptrBase(e); base != nil {
+			// *T is valid, but **T is not
+			if op, _ := base.(*syntax.Operation); op == nil || ptrBase(op) == nil {
+				return embeddedFieldIdent(e.X)
+			}
+		}
+	case *syntax.SelectorExpr:
+		return e.Sel
+	case *syntax.IndexExpr:
+		return embeddedFieldIdent(e.X)
+	}
+	return nil // invalid embedded field
+}
+
+func (check *Checker) declareInSet(oset *objset, pos syntax.Pos, obj Object) bool {
+	if alt := oset.insert(obj); alt != nil {
+		var err error_
+		err.errorf(pos, "%s redeclared", obj.Name())
+		err.recordAltDecl(alt)
+		check.report(&err)
+		return false
+	}
+	return true
+}
+
+func (check *Checker) tag(t *syntax.BasicLit) string {
+	// If t.Bad, an error was reported during parsing.
+	if t != nil && !t.Bad {
+		if t.Kind == syntax.StringLit {
+			if val, err := strconv.Unquote(t.Value); err == nil {
+				return val
+			}
+		}
+		check.errorf(t, invalidAST+"incorrect tag syntax: %q", t.Value)
+	}
+	return ""
+}
+
+func ptrBase(x *syntax.Operation) syntax.Expr {
+	if x.Op == syntax.Mul && x.Y == nil {
+		return x.X
+	}
+	return nil
+}
diff --git a/src/cmd/compile/internal/types2/subst.go b/src/cmd/compile/internal/types2/subst.go
index c8e428c1832..ed3fd654a0e 100644
--- a/src/cmd/compile/internal/types2/subst.go
+++ b/src/cmd/compile/internal/types2/subst.go
@@ -2,215 +2,47 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// This file implements instantiation of generic types
-// through substitution of type parameters by actual
-// types.
+// This file implements type parameter substitution.
 
 package types2
 
 import (
 	"bytes"
 	"cmd/compile/internal/syntax"
-	"fmt"
 )
 
-type substMap struct {
-	// The targs field is currently needed for *Named type substitution.
-	// TODO(gri) rewrite that code, get rid of this field, and make this
-	//           struct just the map (proj)
-	targs []Type
-	proj  map[*TypeParam]Type
-}
+type substMap map[*TypeParam]Type
 
 // makeSubstMap creates a new substitution map mapping tpars[i] to targs[i].
 // If targs[i] is nil, tpars[i] is not substituted.
-func makeSubstMap(tpars []*TypeName, targs []Type) *substMap {
+func makeSubstMap(tpars []*TypeName, targs []Type) substMap {
 	assert(len(tpars) == len(targs))
-	proj := make(map[*TypeParam]Type, len(tpars))
+	proj := make(substMap, len(tpars))
 	for i, tpar := range tpars {
-		// We must expand type arguments otherwise *instance
-		// types end up as components in composite types.
-		// TODO(gri) explain why this causes problems, if it does
-		targ := expand(targs[i]) // possibly nil
-		targs[i] = targ
-		proj[tpar.typ.(*TypeParam)] = targ
+		proj[tpar.typ.(*TypeParam)] = targs[i]
 	}
-	return &substMap{targs, proj}
+	return proj
 }
 
-func (m *substMap) String() string {
-	return fmt.Sprintf("%s", m.proj)
+func (m substMap) empty() bool {
+	return len(m) == 0
 }
 
-func (m *substMap) empty() bool {
-	return len(m.proj) == 0
-}
-
-func (m *substMap) lookup(tpar *TypeParam) Type {
-	if t := m.proj[tpar]; t != nil {
+func (m substMap) lookup(tpar *TypeParam) Type {
+	if t := m[tpar]; t != nil {
 		return t
 	}
 	return tpar
 }
 
-func (check *Checker) instantiate(pos syntax.Pos, typ Type, targs []Type, poslist []syntax.Pos) (res Type) {
-	if check.conf.Trace {
-		check.trace(pos, "-- instantiating %s with %s", typ, typeListString(targs))
-		check.indent++
-		defer func() {
-			check.indent--
-			var under Type
-			if res != nil {
-				// Calling under() here may lead to endless instantiations.
-				// Test case: type T[P any] T[P]
-				// TODO(gri) investigate if that's a bug or to be expected.
-				under = res.Underlying()
-			}
-			check.trace(pos, "=> %s (under = %s)", res, under)
-		}()
-	}
-
-	assert(len(poslist) <= len(targs))
-
-	// TODO(gri) What is better here: work with TypeParams, or work with TypeNames?
-	var tparams []*TypeName
-	switch t := typ.(type) {
-	case *Named:
-		tparams = t.tparams
-	case *Signature:
-		tparams = t.tparams
-		defer func() {
-			// If we had an unexpected failure somewhere don't panic below when
-			// asserting res.(*Signature). Check for *Signature in case Typ[Invalid]
-			// is returned.
-			if _, ok := res.(*Signature); !ok {
-				return
-			}
-			// If the signature doesn't use its type parameters, subst
-			// will not make a copy. In that case, make a copy now (so
-			// we can set tparams to nil w/o causing side-effects).
-			if t == res {
-				copy := *t
-				res = ©
-			}
-			// After instantiating a generic signature, it is not generic
-			// anymore; we need to set tparams to nil.
-			res.(*Signature).tparams = nil
-		}()
-
-	default:
-		check.dump("%v: cannot instantiate %v", pos, typ)
-		unreachable() // only defined types and (defined) functions can be generic
-
-	}
-
-	// the number of supplied types must match the number of type parameters
-	if len(targs) != len(tparams) {
-		// TODO(gri) provide better error message
-		check.errorf(pos, "got %d arguments but %d type parameters", len(targs), len(tparams))
-		return Typ[Invalid]
-	}
-
-	if len(tparams) == 0 {
-		return typ // nothing to do (minor optimization)
-	}
-
-	smap := makeSubstMap(tparams, targs)
-
-	// check bounds
-	for i, tname := range tparams {
-		tpar := tname.typ.(*TypeParam)
-		iface := tpar.Bound()
-		if iface.Empty() {
-			continue // no type bound
-		}
-
-		targ := targs[i]
-
-		// best position for error reporting
-		pos := pos
-		if i < len(poslist) {
-			pos = poslist[i]
-		}
-
-		// The type parameter bound is parameterized with the same type parameters
-		// as the instantiated type; before we can use it for bounds checking we
-		// need to instantiate it with the type arguments with which we instantiate
-		// the parameterized type.
-		iface = check.subst(pos, iface, smap).(*Interface)
-
-		// targ must implement iface (methods)
-		// - check only if we have methods
-		check.completeInterface(nopos, iface)
-		if len(iface.allMethods) > 0 {
-			// If the type argument is a pointer to a type parameter, the type argument's
-			// method set is empty.
-			// TODO(gri) is this what we want? (spec question)
-			if base, isPtr := deref(targ); isPtr && asTypeParam(base) != nil {
-				check.errorf(pos, "%s has no methods", targ)
-				break
-			}
-			if m, wrong := check.missingMethod(targ, iface, true); m != nil {
-				// TODO(gri) needs to print updated name to avoid major confusion in error message!
-				//           (print warning for now)
-				// Old warning:
-				// check.softErrorf(pos, "%s does not satisfy %s (warning: name not updated) = %s (missing method %s)", targ, tpar.bound, iface, m)
-				if m.name == "==" {
-					// We don't want to report "missing method ==".
-					check.softErrorf(pos, "%s does not satisfy comparable", targ)
-				} else if wrong != nil {
-					// TODO(gri) This can still report uninstantiated types which makes the error message
-					//           more difficult to read then necessary.
-					check.softErrorf(pos,
-						"%s does not satisfy %s: wrong method signature\n\tgot  %s\n\twant %s",
-						targ, tpar.bound, wrong, m,
-					)
-				} else {
-					check.softErrorf(pos, "%s does not satisfy %s (missing method %s)", targ, tpar.bound, m.name)
-				}
-				break
-			}
-		}
-
-		// targ's underlying type must also be one of the interface types listed, if any
-		if iface.allTypes == nil {
-			continue // nothing to do
-		}
-
-		// If targ is itself a type parameter, each of its possible types, but at least one, must be in the
-		// list of iface types (i.e., the targ type list must be a non-empty subset of the iface types).
-		if targ := asTypeParam(targ); targ != nil {
-			targBound := targ.Bound()
-			if targBound.allTypes == nil {
-				check.softErrorf(pos, "%s does not satisfy %s (%s has no type constraints)", targ, tpar.bound, targ)
-				break
-			}
-			for _, t := range unpack(targBound.allTypes) {
-				if !iface.isSatisfiedBy(t) {
-					// TODO(gri) match this error message with the one below (or vice versa)
-					check.softErrorf(pos, "%s does not satisfy %s (%s type constraint %s not found in %s)", targ, tpar.bound, targ, t, iface.allTypes)
-					break
-				}
-			}
-			break
-		}
-
-		// Otherwise, targ's type or underlying type must also be one of the interface types listed, if any.
-		if !iface.isSatisfiedBy(targ) {
-			check.softErrorf(pos, "%s does not satisfy %s (%s not found in %s)", targ, tpar.bound, under(targ), iface.allTypes)
-			break
-		}
-	}
-
-	return check.subst(pos, typ, smap)
-}
-
 // subst returns the type typ with its type parameters tpars replaced by
 // the corresponding type arguments targs, recursively.
 // subst is functional in the sense that it doesn't modify the incoming
 // type. If a substitution took place, the result type is different from
 // from the incoming type.
-func (check *Checker) subst(pos syntax.Pos, typ Type, smap *substMap) Type {
+//
+// If the given typMap is nil and check is non-nil, check.typMap is used.
+func (check *Checker) subst(pos syntax.Pos, typ Type, smap substMap, typMap map[string]*Named) Type {
 	if smap.empty() {
 		return typ
 	}
@@ -224,15 +56,33 @@ func (check *Checker) subst(pos syntax.Pos, typ Type, smap *substMap) Type {
 	}
 
 	// general case
-	subst := subster{check, pos, make(map[Type]Type), smap}
+	var subst subster
+	subst.pos = pos
+	subst.smap = smap
+
+	if check != nil {
+		subst.check = check
+		if typMap == nil {
+			typMap = check.typMap
+		}
+	}
+	if typMap == nil {
+		// If we don't have a *Checker and its global type map,
+		// use a local version. Besides avoiding duplicate work,
+		// the type map prevents infinite recursive substitution
+		// for recursive types (example: type T[P any] *T[P]).
+		typMap = make(map[string]*Named)
+	}
+	subst.typMap = typMap
+
 	return subst.typ(typ)
 }
 
 type subster struct {
-	check *Checker
-	pos   syntax.Pos
-	cache map[Type]Type
-	smap  *substMap
+	pos    syntax.Pos
+	smap   substMap
+	check  *Checker // nil if called via Instantiate
+	typMap map[string]*Named
 }
 
 func (subst *subster) typ(typ Type) Type {
@@ -241,7 +91,7 @@ func (subst *subster) typ(typ Type) Type {
 		// Call typOrNil if it's possible that typ is nil.
 		panic("nil typ")
 
-	case *Basic, *bottom, *top:
+	case *Basic, *top:
 		// nothing to do
 
 	case *Array:
@@ -290,29 +140,20 @@ func (subst *subster) typ(typ Type) Type {
 			}
 		}
 
-	case *Sum:
-		types, copied := subst.typeList(t.types)
+	case *Union:
+		terms, copied := subst.termlist(t.terms)
 		if copied {
-			// Don't do it manually, with a Sum literal: the new
-			// types list may not be unique and NewSum may remove
-			// duplicates.
-			return NewSum(types)
+			// term list substitution may introduce duplicate terms (unlikely but possible).
+			// This is ok; lazy type set computation will determine the actual type set
+			// in normal form.
+			return &Union{terms, nil}
 		}
 
 	case *Interface:
 		methods, mcopied := subst.funcList(t.methods)
-		types := t.types
-		if t.types != nil {
-			types = subst.typ(t.types)
-		}
 		embeddeds, ecopied := subst.typeList(t.embeddeds)
-		if mcopied || types != t.types || ecopied {
-			iface := &Interface{methods: methods, types: types, embeddeds: embeddeds}
-			if subst.check == nil {
-				panic("internal error: cannot instantiate interfaces yet")
-			}
-			subst.check.posMap[iface] = subst.check.posMap[t] // satisfy completeInterface requirement
-			subst.check.completeInterface(nopos, iface)
+		if mcopied || ecopied {
+			iface := &Interface{methods: methods, embeddeds: embeddeds, complete: t.complete}
 			return iface
 		}
 
@@ -342,66 +183,58 @@ func (subst *subster) typ(typ Type) Type {
 			}
 		}
 
-		if t.tparams == nil {
+		if t.TParams().Len() == 0 {
 			dump(">>> %s is not parameterized", t)
 			return t // type is not parameterized
 		}
 
-		var new_targs []Type
+		var newTArgs []Type
+		assert(len(t.targs) == t.TParams().Len())
 
-		if len(t.targs) > 0 {
-			// already instantiated
-			dump(">>> %s already instantiated", t)
-			assert(len(t.targs) == len(t.tparams))
-			// For each (existing) type argument targ, determine if it needs
-			// to be substituted; i.e., if it is or contains a type parameter
-			// that has a type argument for it.
-			for i, targ := range t.targs {
-				dump(">>> %d targ = %s", i, targ)
-				new_targ := subst.typ(targ)
-				if new_targ != targ {
-					dump(">>> substituted %d targ %s => %s", i, targ, new_targ)
-					if new_targs == nil {
-						new_targs = make([]Type, len(t.tparams))
-						copy(new_targs, t.targs)
-					}
-					new_targs[i] = new_targ
+		// already instantiated
+		dump(">>> %s already instantiated", t)
+		// For each (existing) type argument targ, determine if it needs
+		// to be substituted; i.e., if it is or contains a type parameter
+		// that has a type argument for it.
+		for i, targ := range t.targs {
+			dump(">>> %d targ = %s", i, targ)
+			new_targ := subst.typ(targ)
+			if new_targ != targ {
+				dump(">>> substituted %d targ %s => %s", i, targ, new_targ)
+				if newTArgs == nil {
+					newTArgs = make([]Type, t.TParams().Len())
+					copy(newTArgs, t.targs)
 				}
+				newTArgs[i] = new_targ
 			}
+		}
 
-			if new_targs == nil {
-				dump(">>> nothing to substitute in %s", t)
-				return t // nothing to substitute
-			}
-		} else {
-			// not yet instantiated
-			dump(">>> first instantiation of %s", t)
-			new_targs = subst.smap.targs
+		if newTArgs == nil {
+			dump(">>> nothing to substitute in %s", t)
+			return t // nothing to substitute
 		}
 
 		// before creating a new named type, check if we have this one already
-		h := instantiatedHash(t, new_targs)
+		h := instantiatedHash(t, newTArgs)
 		dump(">>> new type hash: %s", h)
-		if subst.check != nil {
-			if named, found := subst.check.typMap[h]; found {
-				dump(">>> found %s", named)
-				subst.cache[t] = named
-				return named
-			}
+		if named, found := subst.typMap[h]; found {
+			dump(">>> found %s", named)
+			return named
 		}
 
-		// create a new named type and populate caches to avoid endless recursion
+		// create a new named type and populate typMap to avoid endless recursion
 		tname := NewTypeName(subst.pos, t.obj.pkg, t.obj.name, nil)
-		named := subst.check.newNamed(tname, t, t.underlying, t.tparams, t.methods) // method signatures are updated lazily
-		named.targs = new_targs
-		if subst.check != nil {
-			subst.check.typMap[h] = named
-		}
-		subst.cache[t] = named
+		t.load()
+		named := subst.check.newNamed(tname, t.orig, t.underlying, t.TParams(), t.methods) // method signatures are updated lazily
+		named.targs = newTArgs
+		subst.typMap[h] = named
+		t.expand(subst.typMap) // must happen after typMap update to avoid infinite recursion
 
 		// do the substitution
-		dump(">>> subst %s with %s (new: %s)", t.underlying, subst.smap, new_targs)
+		dump(">>> subst %s with %s (new: %s)", t.underlying, subst.smap, newTArgs)
 		named.underlying = subst.typOrNil(t.underlying)
+		dump(">>> underlying: %v", named.underlying)
+		assert(named.underlying != nil)
 		named.fromRHS = named.underlying // for cycle detection (Checker.validType)
 
 		return named
@@ -409,10 +242,6 @@ func (subst *subster) typ(typ Type) Type {
 	case *TypeParam:
 		return subst.smap.lookup(t)
 
-	case *instance:
-		// TODO(gri) can we avoid the expansion here and just substitute the type parameters?
-		return subst.typ(t.expand())
-
 	default:
 		unimplemented()
 	}
@@ -420,14 +249,17 @@ func (subst *subster) typ(typ Type) Type {
 	return typ
 }
 
-// TODO(gri) Eventually, this should be more sophisticated.
-//           It won't work correctly for locally declared types.
+var instanceHashing = 0
+
 func instantiatedHash(typ *Named, targs []Type) string {
+	assert(instanceHashing == 0)
+	instanceHashing++
 	var buf bytes.Buffer
 	writeTypeName(&buf, typ.obj, nil)
 	buf.WriteByte('[')
 	writeTypeList(&buf, targs, nil, nil)
 	buf.WriteByte(']')
+	instanceHashing--
 
 	// With respect to the represented type, whether a
 	// type is fully expanded or stored as instance
@@ -545,3 +377,21 @@ func (subst *subster) typeList(in []Type) (out []Type, copied bool) {
 	}
 	return
 }
+
+func (subst *subster) termlist(in []*Term) (out []*Term, copied bool) {
+	out = in
+	for i, t := range in {
+		if u := subst.typ(t.typ); u != t.typ {
+			if !copied {
+				// first function that got substituted => allocate new out slice
+				// and copy all functions
+				new := make([]*Term, len(in))
+				copy(new, out)
+				out = new
+				copied = true
+			}
+			out[i] = NewTerm(t.tilde, u)
+		}
+	}
+	return
+}
diff --git a/src/cmd/compile/internal/types2/termlist.go b/src/cmd/compile/internal/types2/termlist.go
new file mode 100644
index 00000000000..378ba6b8f4c
--- /dev/null
+++ b/src/cmd/compile/internal/types2/termlist.go
@@ -0,0 +1,167 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import "bytes"
+
+// A termlist represents the type set represented by the union
+// t1 ∪ y2 ∪ ... tn of the type sets of the terms t1 to tn.
+// A termlist is in normal form if all terms are disjoint.
+// termlist operations don't require the operands to be in
+// normal form.
+type termlist []*term
+
+// allTermlist represents the set of all types.
+// It is in normal form.
+var allTermlist = termlist{new(term)}
+
+// String prints the termlist exactly (without normalization).
+func (xl termlist) String() string {
+	if len(xl) == 0 {
+		return "∅"
+	}
+	var buf bytes.Buffer
+	for i, x := range xl {
+		if i > 0 {
+			buf.WriteString(" ∪ ")
+		}
+		buf.WriteString(x.String())
+	}
+	return buf.String()
+}
+
+// isEmpty reports whether the termlist xl represents the empty set of types.
+func (xl termlist) isEmpty() bool {
+	// If there's a non-nil term, the entire list is not empty.
+	// If the termlist is in normal form, this requires at most
+	// one iteration.
+	for _, x := range xl {
+		if x != nil {
+			return false
+		}
+	}
+	return true
+}
+
+// isAll reports whether the termlist xl represents the set of all types.
+func (xl termlist) isAll() bool {
+	// If there's a 𝓤 term, the entire list is 𝓤.
+	// If the termlist is in normal form, this requires at most
+	// one iteration.
+	for _, x := range xl {
+		if x != nil && x.typ == nil {
+			return true
+		}
+	}
+	return false
+}
+
+// norm returns the normal form of xl.
+func (xl termlist) norm() termlist {
+	// Quadratic algorithm, but good enough for now.
+	// TODO(gri) fix asymptotic performance
+	used := make([]bool, len(xl))
+	var rl termlist
+	for i, xi := range xl {
+		if xi == nil || used[i] {
+			continue
+		}
+		for j := i + 1; j < len(xl); j++ {
+			xj := xl[j]
+			if xj == nil || used[j] {
+				continue
+			}
+			if u1, u2 := xi.union(xj); u2 == nil {
+				// If we encounter a 𝓤 term, the entire list is 𝓤.
+				// Exit early.
+				// (Note that this is not just an optimization;
+				// if we continue, we may end up with a 𝓤 term
+				// and other terms and the result would not be
+				// in normal form.)
+				if u1.typ == nil {
+					return allTermlist
+				}
+				xi = u1
+				used[j] = true // xj is now unioned into xi - ignore it in future iterations
+			}
+		}
+		rl = append(rl, xi)
+	}
+	return rl
+}
+
+// If the type set represented by xl is specified by a single (non-𝓤) term,
+// structuralType returns that type. Otherwise it returns nil.
+func (xl termlist) structuralType() Type {
+	if nl := xl.norm(); len(nl) == 1 {
+		return nl[0].typ // if nl.isAll() then typ is nil, which is ok
+	}
+	return nil
+}
+
+// union returns the union xl ∪ yl.
+func (xl termlist) union(yl termlist) termlist {
+	return append(xl, yl...).norm()
+}
+
+// intersect returns the intersection xl ∩ yl.
+func (xl termlist) intersect(yl termlist) termlist {
+	if xl.isEmpty() || yl.isEmpty() {
+		return nil
+	}
+
+	// Quadratic algorithm, but good enough for now.
+	// TODO(gri) fix asymptotic performance
+	var rl termlist
+	for _, x := range xl {
+		for _, y := range yl {
+			if r := x.intersect(y); r != nil {
+				rl = append(rl, r)
+			}
+		}
+	}
+	return rl.norm()
+}
+
+// equal reports whether xl and yl represent the same type set.
+func (xl termlist) equal(yl termlist) bool {
+	// TODO(gri) this should be more efficient
+	return xl.subsetOf(yl) && yl.subsetOf(xl)
+}
+
+// includes reports whether t ∈ xl.
+func (xl termlist) includes(t Type) bool {
+	for _, x := range xl {
+		if x.includes(t) {
+			return true
+		}
+	}
+	return false
+}
+
+// supersetOf reports whether y ⊆ xl.
+func (xl termlist) supersetOf(y *term) bool {
+	for _, x := range xl {
+		if y.subsetOf(x) {
+			return true
+		}
+	}
+	return false
+}
+
+// subsetOf reports whether xl ⊆ yl.
+func (xl termlist) subsetOf(yl termlist) bool {
+	if yl.isEmpty() {
+		return xl.isEmpty()
+	}
+
+	// each term x of xl must be a subset of yl
+	for _, x := range xl {
+		if !yl.supersetOf(x) {
+			return false // x is not a subset yl
+		}
+	}
+	return true
+}
diff --git a/src/cmd/compile/internal/types2/termlist_test.go b/src/cmd/compile/internal/types2/termlist_test.go
new file mode 100644
index 00000000000..2f3772ddeb8
--- /dev/null
+++ b/src/cmd/compile/internal/types2/termlist_test.go
@@ -0,0 +1,313 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"strings"
+	"testing"
+)
+
+// maketl makes a term list from a string of the term list.
+func maketl(s string) termlist {
+	s = strings.Replace(s, " ", "", -1)
+	names := strings.Split(s, "∪")
+	r := make(termlist, len(names))
+	for i, n := range names {
+		r[i] = testTerm(n)
+	}
+	return r
+}
+
+func TestTermlistTop(t *testing.T) {
+	if !allTermlist.isAll() {
+		t.Errorf("allTermlist is not the set of all types")
+	}
+}
+
+func TestTermlistString(t *testing.T) {
+	for _, want := range []string{
+		"∅",
+		"𝓤",
+		"int",
+		"~int",
+		"myInt",
+		"∅ ∪ ∅",
+		"𝓤 ∪ 𝓤",
+		"∅ ∪ 𝓤 ∪ int",
+		"∅ ∪ 𝓤 ∪ int ∪ myInt",
+	} {
+		if got := maketl(want).String(); got != want {
+			t.Errorf("(%v).String() == %v", want, got)
+		}
+	}
+}
+
+func TestTermlistIsEmpty(t *testing.T) {
+	for test, want := range map[string]bool{
+		"∅":             true,
+		"∅ ∪ ∅":         true,
+		"∅ ∪ ∅ ∪ 𝓤":     false,
+		"∅ ∪ ∅ ∪ myInt": false,
+		"𝓤":             false,
+		"𝓤 ∪ int":       false,
+		"𝓤 ∪ myInt ∪ ∅": false,
+	} {
+		xl := maketl(test)
+		got := xl.isEmpty()
+		if got != want {
+			t.Errorf("(%v).isEmpty() == %v; want %v", test, got, want)
+		}
+	}
+}
+
+func TestTermlistIsAll(t *testing.T) {
+	for test, want := range map[string]bool{
+		"∅":             false,
+		"∅ ∪ ∅":         false,
+		"int ∪ ~string": false,
+		"~int ∪ myInt":  false,
+		"∅ ∪ ∅ ∪ 𝓤":     true,
+		"𝓤":             true,
+		"𝓤 ∪ int":       true,
+		"myInt ∪ 𝓤":     true,
+	} {
+		xl := maketl(test)
+		got := xl.isAll()
+		if got != want {
+			t.Errorf("(%v).isAll() == %v; want %v", test, got, want)
+		}
+	}
+}
+
+func TestTermlistNorm(t *testing.T) {
+	for _, test := range []struct {
+		xl, want string
+	}{
+		{"∅", "∅"},
+		{"∅ ∪ ∅", "∅"},
+		{"∅ ∪ int", "int"},
+		{"∅ ∪ myInt", "myInt"},
+		{"𝓤 ∪ int", "𝓤"},
+		{"𝓤 ∪ myInt", "𝓤"},
+		{"int ∪ myInt", "int ∪ myInt"},
+		{"~int ∪ int", "~int"},
+		{"~int ∪ myInt", "~int"},
+		{"int ∪ ~string ∪ int", "int ∪ ~string"},
+		{"~int ∪ string ∪ 𝓤 ∪ ~string ∪ int", "𝓤"},
+		{"~int ∪ string ∪ myInt ∪ ~string ∪ int", "~int ∪ ~string"},
+	} {
+		xl := maketl(test.xl)
+		got := maketl(test.xl).norm()
+		if got.String() != test.want {
+			t.Errorf("(%v).norm() = %v; want %v", xl, got, test.want)
+		}
+	}
+}
+
+func TestTermlistStructuralType(t *testing.T) {
+	// helper to deal with nil types
+	tstring := func(typ Type) string {
+		if typ == nil {
+			return "nil"
+		}
+		return typ.String()
+	}
+
+	for test, want := range map[string]string{
+		"∅":                 "nil",
+		"𝓤":                 "nil",
+		"int":               "int",
+		"myInt":             "myInt",
+		"~int":              "int",
+		"~int ∪ string":     "nil",
+		"~int ∪ myInt":      "int",
+		"∅ ∪ int":           "int",
+		"∅ ∪ ~int":          "int",
+		"∅ ∪ ~int ∪ string": "nil",
+	} {
+		xl := maketl(test)
+		got := tstring(xl.structuralType())
+		if got != want {
+			t.Errorf("(%v).structuralType() == %v; want %v", test, got, want)
+		}
+	}
+}
+
+func TestTermlistUnion(t *testing.T) {
+	for _, test := range []struct {
+		xl, yl, want string
+	}{
+
+		{"∅", "∅", "∅"},
+		{"∅", "𝓤", "𝓤"},
+		{"∅", "int", "int"},
+		{"𝓤", "~int", "𝓤"},
+		{"int", "~int", "~int"},
+		{"int", "string", "int ∪ string"},
+		{"int", "myInt", "int ∪ myInt"},
+		{"~int", "myInt", "~int"},
+		{"int ∪ string", "~string", "int ∪ ~string"},
+		{"~int ∪ string", "~string ∪ int", "~int ∪ ~string"},
+		{"~int ∪ string ∪ ∅", "~string ∪ int", "~int ∪ ~string"},
+		{"~int ∪ myInt ∪ ∅", "~string ∪ int", "~int ∪ ~string"},
+		{"~int ∪ string ∪ 𝓤", "~string ∪ int", "𝓤"},
+		{"~int ∪ string ∪ myInt", "~string ∪ int", "~int ∪ ~string"},
+	} {
+		xl := maketl(test.xl)
+		yl := maketl(test.yl)
+		got := xl.union(yl).String()
+		if got != test.want {
+			t.Errorf("(%v).union(%v) = %v; want %v", test.xl, test.yl, got, test.want)
+		}
+	}
+}
+
+func TestTermlistIntersect(t *testing.T) {
+	for _, test := range []struct {
+		xl, yl, want string
+	}{
+
+		{"∅", "∅", "∅"},
+		{"∅", "𝓤", "∅"},
+		{"∅", "int", "∅"},
+		{"∅", "myInt", "∅"},
+		{"𝓤", "~int", "~int"},
+		{"𝓤", "myInt", "myInt"},
+		{"int", "~int", "int"},
+		{"int", "string", "∅"},
+		{"int", "myInt", "∅"},
+		{"~int", "myInt", "myInt"},
+		{"int ∪ string", "~string", "string"},
+		{"~int ∪ string", "~string ∪ int", "int ∪ string"},
+		{"~int ∪ string ∪ ∅", "~string ∪ int", "int ∪ string"},
+		{"~int ∪ myInt ∪ ∅", "~string ∪ int", "int"},
+		{"~int ∪ string ∪ 𝓤", "~string ∪ int", "int ∪ ~string"},
+		{"~int ∪ string ∪ myInt", "~string ∪ int", "int ∪ string"},
+	} {
+		xl := maketl(test.xl)
+		yl := maketl(test.yl)
+		got := xl.intersect(yl).String()
+		if got != test.want {
+			t.Errorf("(%v).intersect(%v) = %v; want %v", test.xl, test.yl, got, test.want)
+		}
+	}
+}
+
+func TestTermlistEqual(t *testing.T) {
+	for _, test := range []struct {
+		xl, yl string
+		want   bool
+	}{
+		{"∅", "∅", true},
+		{"∅", "𝓤", false},
+		{"𝓤", "𝓤", true},
+		{"𝓤 ∪ int", "𝓤", true},
+		{"𝓤 ∪ int", "string ∪ 𝓤", true},
+		{"𝓤 ∪ myInt", "string ∪ 𝓤", true},
+		{"int ∪ ~string", "string ∪ int", false},
+		{"~int ∪ string", "string ∪ myInt", false},
+		{"int ∪ ~string ∪ ∅", "string ∪ int ∪ ~string", true},
+	} {
+		xl := maketl(test.xl)
+		yl := maketl(test.yl)
+		got := xl.equal(yl)
+		if got != test.want {
+			t.Errorf("(%v).equal(%v) = %v; want %v", test.xl, test.yl, got, test.want)
+		}
+	}
+}
+
+func TestTermlistIncludes(t *testing.T) {
+	for _, test := range []struct {
+		xl, typ string
+		want    bool
+	}{
+		{"∅", "int", false},
+		{"𝓤", "int", true},
+		{"~int", "int", true},
+		{"int", "string", false},
+		{"~int", "string", false},
+		{"~int", "myInt", true},
+		{"int ∪ string", "string", true},
+		{"~int ∪ string", "int", true},
+		{"~int ∪ string", "myInt", true},
+		{"~int ∪ myInt ∪ ∅", "myInt", true},
+		{"myInt ∪ ∅ ∪ 𝓤", "int", true},
+	} {
+		xl := maketl(test.xl)
+		yl := testTerm(test.typ).typ
+		got := xl.includes(yl)
+		if got != test.want {
+			t.Errorf("(%v).includes(%v) = %v; want %v", test.xl, yl, got, test.want)
+		}
+	}
+}
+
+func TestTermlistSupersetOf(t *testing.T) {
+	for _, test := range []struct {
+		xl, typ string
+		want    bool
+	}{
+		{"∅", "∅", true},
+		{"∅", "𝓤", false},
+		{"∅", "int", false},
+		{"𝓤", "∅", true},
+		{"𝓤", "𝓤", true},
+		{"𝓤", "int", true},
+		{"𝓤", "~int", true},
+		{"𝓤", "myInt", true},
+		{"~int", "int", true},
+		{"~int", "~int", true},
+		{"~int", "myInt", true},
+		{"int", "~int", false},
+		{"myInt", "~int", false},
+		{"int", "string", false},
+		{"~int", "string", false},
+		{"int ∪ string", "string", true},
+		{"int ∪ string", "~string", false},
+		{"~int ∪ string", "int", true},
+		{"~int ∪ string", "myInt", true},
+		{"~int ∪ string ∪ ∅", "string", true},
+		{"~string ∪ ∅ ∪ 𝓤", "myInt", true},
+	} {
+		xl := maketl(test.xl)
+		y := testTerm(test.typ)
+		got := xl.supersetOf(y)
+		if got != test.want {
+			t.Errorf("(%v).supersetOf(%v) = %v; want %v", test.xl, y, got, test.want)
+		}
+	}
+}
+
+func TestTermlistSubsetOf(t *testing.T) {
+	for _, test := range []struct {
+		xl, yl string
+		want   bool
+	}{
+		{"∅", "∅", true},
+		{"∅", "𝓤", true},
+		{"𝓤", "∅", false},
+		{"𝓤", "𝓤", true},
+		{"int", "int ∪ string", true},
+		{"~int", "int ∪ string", false},
+		{"~int", "myInt ∪ string", false},
+		{"myInt", "~int ∪ string", true},
+		{"~int", "string ∪ string ∪ int ∪ ~int", true},
+		{"myInt", "string ∪ string ∪ ~int", true},
+		{"int ∪ string", "string", false},
+		{"int ∪ string", "string ∪ int", true},
+		{"int ∪ ~string", "string ∪ int", false},
+		{"myInt ∪ ~string", "string ∪ int ∪ 𝓤", true},
+		{"int ∪ ~string", "string ∪ int ∪ ∅ ∪ string", false},
+		{"int ∪ myInt", "string ∪ ~int ∪ ∅ ∪ string", true},
+	} {
+		xl := maketl(test.xl)
+		yl := maketl(test.yl)
+		got := xl.subsetOf(yl)
+		if got != test.want {
+			t.Errorf("(%v).subsetOf(%v) = %v; want %v", test.xl, test.yl, got, test.want)
+		}
+	}
+}
diff --git a/src/cmd/compile/internal/types2/testdata/check/builtins.go2 b/src/cmd/compile/internal/types2/testdata/check/builtins.go2
index 3918d836b52..0cfea93bf6d 100644
--- a/src/cmd/compile/internal/types2/testdata/check/builtins.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/builtins.go2
@@ -6,48 +6,222 @@
 
 package builtins
 
-type Bmc interface {
-	type map[rune]string, chan int
+import "unsafe"
+
+// close
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func _[T any](ch T) {
+	close(ch /* ERROR cannot close non-channel */)
 }
 
-type Bms interface {
-	type map[string]int, []int
+func _[T C0](ch T) {
+	close(ch /* ERROR cannot close non-channel */)
 }
 
-type Bcs interface {
-	type chan bool, []float64
+func _[T C1](ch T) {
+	close(ch)
 }
 
-type Bss interface {
-	type []int, []string
+func _[T C2](ch T) {
+	close(ch /* ERROR cannot close receive-only channel */)
 }
 
-func _[T any] () {
-	_ = make(T /* ERROR invalid argument */ )
-	_ = make(T /* ERROR invalid argument */ , 10)
-	_ = make(T /* ERROR invalid argument */ , 10, 20)
+func _[T C3](ch T) {
+	close(ch)
 }
 
-func _[T Bmc] () {
-	_ = make(T)
-	_ = make(T, 10)
-	_ = make /* ERROR expects 1 or 2 arguments */ (T, 10, 20)
+func _[T C4](ch T) {
+	close(ch)
 }
 
-func _[T Bms] () {
-	_ = make /* ERROR expects 2 arguments */ (T)
-	_ = make(T, 10)
-	_ = make /* ERROR expects 2 arguments */ (T, 10, 20)
+func _[T C5[X], X any](ch T) {
+	close(ch)
 }
 
-func _[T Bcs] () {
-	_ = make /* ERROR expects 2 arguments */ (T)
-	_ = make(T, 10)
-	_ = make /* ERROR expects 2 arguments */ (T, 10, 20)
+// delete
+
+type M0 interface{ int }
+type M1 interface{ map[string]int }
+type M2 interface { map[string]int | map[string]float64 }
+type M3 interface{ map[string]int | map[rune]int }
+type M4[K comparable, V any] interface{ map[K]V | map[rune]V }
+
+func _[T any](m T) {
+	delete(m /* ERROR not a map */, "foo")
 }
 
-func _[T Bss] () {
-	_ = make /* ERROR expects 2 or 3 arguments */ (T)
-	_ = make(T, 10)
-	_ = make(T, 10, 20)
+func _[T M0](m T) {
+	delete(m /* ERROR not a map */, "foo")
+}
+
+func _[T M1](m T) {
+	delete(m, "foo")
+}
+
+func _[T M2](m T) {
+	delete(m, "foo")
+	delete(m, 0 /* ERROR cannot use .* as string */)
+}
+
+func _[T M3](m T) {
+	delete(m /* ERROR must have identical key types */, "foo")
+}
+
+func _[T M4[rune, V], V any](m T) {
+	delete(m, 'k')
+}
+
+func _[T M4[K, V], K comparable, V any](m T) {
+	delete(m /* ERROR must have identical key types */, "foo")
+}
+
+// make
+
+func _[
+	S1 interface{ []int },
+	S2 interface{ []int | chan int },
+
+	M1 interface{ map[string]int },
+	M2 interface{ map[string]int | chan int },
+
+	C1 interface{ chan int },
+	C2 interface{ chan int | chan string },
+]() {
+	type S0 []int
+	_ = make([]int, 10)
+	_ = make(S0, 10)
+	_ = make(S1, 10)
+	_ = make /* ERROR not enough arguments */ ()
+	_ = make /* ERROR expects 2 or 3 arguments */ (S1)
+	_ = make(S1, 10, 20)
+	_ = make /* ERROR expects 2 or 3 arguments */ (S1, 10, 20, 30)
+	_ = make(S2 /* ERROR cannot make .* no structural type */ , 10)
+
+	type M0 map[string]int
+	_ = make(map[string]int)
+	_ = make(M0)
+	_ = make(M1)
+	_ = make(M1, 10)
+	_ = make/* ERROR expects 1 or 2 arguments */(M1, 10, 20)
+	_ = make(M2 /* ERROR cannot make .* no structural type */ )
+
+	type C0 chan int
+	_ = make(chan int)
+	_ = make(C0)
+	_ = make(C1)
+	_ = make(C1, 10)
+	_ = make/* ERROR expects 1 or 2 arguments */(C1, 10, 20)
+	_ = make(C2 /* ERROR cannot make .* no structural type */ )
+}
+
+// unsafe.Alignof
+
+func _[T comparable]() {
+	var (
+		b int64
+		a [10]T
+		s struct{ f T }
+		p *T
+		l []T
+		f func(T)
+		i interface{ m() T }
+		c chan T
+		m map[T]T
+		t T
+	)
+
+	const bb = unsafe.Alignof(b)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Alignof(p)
+	assert(pp == 8)
+	const ll = unsafe.Alignof(l)
+	assert(ll == 8)
+	const ff = unsafe.Alignof(f)
+	assert(ff == 8)
+	const ii = unsafe.Alignof(i)
+	assert(ii == 8)
+	const cc = unsafe.Alignof(c)
+	assert(cc == 8)
+	const mm = unsafe.Alignof(m)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
+}
+
+// unsafe.Offsetof
+
+func _[T comparable]() {
+	var (
+		b struct{ _, f int64 }
+		a struct{ _, f [10]T }
+		s struct{ _, f struct{ f T } }
+		p struct{ _, f *T }
+		l struct{ _, f []T }
+		f struct{ _, f func(T) }
+		i struct{ _, f interface{ m() T } }
+		c struct{ _, f chan T }
+		m struct{ _, f map[T]T }
+		t struct{ _, f T }
+	)
+
+	const bb = unsafe.Offsetof(b.f)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Offsetof(p.f)
+	assert(pp == 8)
+	const ll = unsafe.Offsetof(l.f)
+	assert(ll == 24)
+	const ff = unsafe.Offsetof(f.f)
+	assert(ff == 8)
+	const ii = unsafe.Offsetof(i.f)
+	assert(ii == 16)
+	const cc = unsafe.Offsetof(c.f)
+	assert(cc == 8)
+	const mm = unsafe.Offsetof(m.f)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
+}
+
+// unsafe.Sizeof
+
+func _[T comparable]() {
+	var (
+		b int64
+		a [10]T
+		s struct{ f T }
+		p *T
+		l []T
+		f func(T)
+		i interface{ m() T }
+		c chan T
+		m map[T]T
+		t T
+	)
+
+	const bb = unsafe.Sizeof(b)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Sizeof(p)
+	assert(pp == 8)
+	const ll = unsafe.Sizeof(l)
+	assert(ll == 24)
+	const ff = unsafe.Sizeof(f)
+	assert(ff == 8)
+	const ii = unsafe.Sizeof(i)
+	assert(ii == 16)
+	const cc = unsafe.Sizeof(c)
+	assert(cc == 8)
+	const mm = unsafe.Sizeof(m)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
 }
diff --git a/src/cmd/compile/internal/types2/testdata/check/builtins.src b/src/cmd/compile/internal/types2/testdata/check/builtins.src
index 6d1f47129b9..17e4068d654 100644
--- a/src/cmd/compile/internal/types2/testdata/check/builtins.src
+++ b/src/cmd/compile/internal/types2/testdata/check/builtins.src
@@ -144,7 +144,7 @@ func close1() {
 	var r <-chan int
 	close() // ERROR not enough arguments
 	close(1, 2) // ERROR too many arguments
-	close(42 /* ERROR not a channel */)
+	close(42 /* ERROR cannot close non-channel */)
 	close(r /* ERROR receive-only channel */)
 	close(c)
 	_ = close /* ERROR used as value */ (c)
diff --git a/src/cmd/compile/internal/types2/testdata/check/const0.src b/src/cmd/compile/internal/types2/testdata/check/const0.src
index 5608b1549ba..3cffdf904c8 100644
--- a/src/cmd/compile/internal/types2/testdata/check/const0.src
+++ b/src/cmd/compile/internal/types2/testdata/check/const0.src
@@ -27,7 +27,7 @@ const (
 	ub1 = true
 	ub2 = 2 < 1
 	ub3 = ui1 == uf1
-	ub4 = true /* ERROR "cannot convert" */ == 0
+	ub4 = true /* ERROR "mismatched types untyped bool and untyped int" */ == 0
 
 	// integer values
 	ui0 = 0
diff --git a/src/cmd/compile/internal/types2/testdata/check/cycles4.src b/src/cmd/compile/internal/types2/testdata/check/cycles4.src
index 445babca68b..924aabf475f 100644
--- a/src/cmd/compile/internal/types2/testdata/check/cycles4.src
+++ b/src/cmd/compile/internal/types2/testdata/check/cycles4.src
@@ -4,6 +4,8 @@
 
 package p
 
+import "unsafe"
+
 // Check that all methods of T are collected before
 // determining the result type of m (which embeds
 // all methods of T).
@@ -13,7 +15,7 @@ type T interface {
 	E
 }
 
-var _ = T.m(nil).m().e()
+var _ int = T.m(nil).m().e()
 
 type E interface {
 	e() int
@@ -22,7 +24,7 @@ type E interface {
 // Check that unresolved forward chains are followed
 // (see also comment in resolver.go, checker.typeDecl).
 
-var _ = C.m(nil).m().e()
+var _ int = C.m(nil).m().e()
 
 type A B
 
@@ -108,3 +110,12 @@ type Element interface {
 type Event interface {
 	Target() Element
 }
+
+// Check that accessing an interface method too early doesn't lead
+// to follow-on errors due to an incorrectly computed type set.
+
+type T8 interface {
+	m() [unsafe.Sizeof(T8.m /* ERROR undefined */ )]int
+}
+
+var _ = T8.m // no error expected here
diff --git a/src/cmd/compile/internal/types2/testdata/check/decls0.src b/src/cmd/compile/internal/types2/testdata/check/decls0.src
index e78d8867e09..f051a4f2acb 100644
--- a/src/cmd/compile/internal/types2/testdata/check/decls0.src
+++ b/src/cmd/compile/internal/types2/testdata/check/decls0.src
@@ -4,7 +4,7 @@
 
 // type declarations
 
-package decls0
+package go1_17 // don't permit non-interface elements in interfaces
 
 import "unsafe"
 
@@ -185,10 +185,10 @@ func f2(x *f2 /* ERROR "not a type" */ ) {}
 func f3() (x f3 /* ERROR "not a type" */ ) { return }
 func f4() (x *f4 /* ERROR "not a type" */ ) { return }
 
-func (S0) m1(x S0 /* ERROR value .* is not a type */ .m1) {}
-func (S0) m2(x *S0 /* ERROR value .* is not a type */ .m2) {}
-func (S0) m3() (x S0 /* ERROR value .* is not a type */ .m3) { return }
-func (S0) m4() (x *S0 /* ERROR value .* is not a type */ .m4) { return }
+func (S0) m1(x S0 /* ERROR illegal cycle in method declaration */ .m1) {}
+func (S0) m2(x *S0 /* ERROR illegal cycle in method declaration */ .m2) {}
+func (S0) m3() (x S0 /* ERROR illegal cycle in method declaration */ .m3) { return }
+func (S0) m4() (x *S0 /* ERROR illegal cycle in method declaration */ .m4) { return }
 
 // interfaces may not have any blank methods
 type BlankI interface {
diff --git a/src/cmd/compile/internal/types2/testdata/check/decls1.src b/src/cmd/compile/internal/types2/testdata/check/decls1.src
index e6beb783589..1167ced366e 100644
--- a/src/cmd/compile/internal/types2/testdata/check/decls1.src
+++ b/src/cmd/compile/internal/types2/testdata/check/decls1.src
@@ -83,7 +83,7 @@ var (
 
 // Constant expression initializations
 var (
-	v1 = 1 /* ERROR "cannot convert" */ + "foo"
+	v1 = 1 /* ERROR "mismatched types untyped int and untyped string" */ + "foo"
 	v2 = c + 255
 	v3 = c + 256 /* ERROR "overflows" */
 	v4 = r + 2147483647
diff --git a/src/cmd/compile/internal/types2/testdata/check/expr1.src b/src/cmd/compile/internal/types2/testdata/check/expr1.src
index 4ead815158f..85ad234bbbf 100644
--- a/src/cmd/compile/internal/types2/testdata/check/expr1.src
+++ b/src/cmd/compile/internal/types2/testdata/check/expr1.src
@@ -111,10 +111,10 @@ type mystring string
 func _(x, y string, z mystring) {
 	x = x + "foo"
 	x = x /* ERROR not defined */ - "foo"
-	x = x + 1 // ERROR cannot convert
+	x = x + 1 // ERROR mismatched types string and untyped int
 	x = x + y
 	x = x /* ERROR not defined */ - y
-	x = x * 10 // ERROR cannot convert
+	x = x * 10 // ERROR mismatched types string and untyped int
 }
 
 func f() (a, b int) { return }
diff --git a/src/cmd/compile/internal/types2/testdata/check/expr2.src b/src/cmd/compile/internal/types2/testdata/check/expr2.src
index 0c959e80119..f9726b5de53 100644
--- a/src/cmd/compile/internal/types2/testdata/check/expr2.src
+++ b/src/cmd/compile/internal/types2/testdata/check/expr2.src
@@ -10,7 +10,7 @@ func _bool() {
 	const t = true == true
 	const f = true == false
 	_ = t /* ERROR "cannot compare" */ < f
-	_ = 0 /* ERROR "cannot convert" */ == t
+	_ = 0 /* ERROR "mismatched types untyped int and untyped bool" */ == t
 	var b bool
 	var x, y float32
 	b = x < y
diff --git a/src/cmd/compile/internal/types2/testdata/check/expr3.src b/src/cmd/compile/internal/types2/testdata/check/expr3.src
index eab3f72c4d5..fd28421dc89 100644
--- a/src/cmd/compile/internal/types2/testdata/check/expr3.src
+++ b/src/cmd/compile/internal/types2/testdata/check/expr3.src
@@ -104,7 +104,7 @@ func indexes() {
 	var ok mybool
 	_, ok = m["bar"]
 	_ = ok
-	_ = m[0 /* ERROR "cannot use 0" */ ] + "foo" // ERROR "cannot convert"
+	_ = m[0 /* ERROR "cannot use 0" */ ] + "foo" // ERROR "mismatched types int and untyped string"
 
 	var t string
 	_ = t[- /* ERROR "negative" */ 1]
diff --git a/src/cmd/compile/internal/types2/testdata/check/issues.go2 b/src/cmd/compile/internal/types2/testdata/check/issues.go2
index 1c73b5da921..effc2db7ae3 100644
--- a/src/cmd/compile/internal/types2/testdata/check/issues.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/issues.go2
@@ -24,25 +24,23 @@ func _() {
 	eql[io.Reader](nil, nil)
 }
 
-// If we have a receiver of pointer type (below: *T) we must ignore
-// the pointer in the implementation of the method lookup because
-// the type bound of T is an interface and pointer to interface types
-// have no methods and then the lookup would fail.
+// If we have a receiver of pointer to type parameter type (below: *T)
+// we don't have any methods, like for interfaces.
 type C[T any] interface {
     m()
 }
 
 // using type bound C
 func _[T C[T]](x *T) {
-	x.m()
+	x.m /* ERROR x\.m undefined */ ()
 }
 
 // using an interface literal as bound
 func _[T interface{ m() }](x *T) {
-	x.m()
+	x.m /* ERROR x\.m undefined */ ()
 }
 
-func f2[_ interface{ m1(); m2() }]()
+func f2[_ interface{ m1(); m2() }]() {}
 
 type T struct{}
 func (T) m1()
@@ -57,15 +55,15 @@ func _() {
 // type with a type list constraint, all of the type argument's types in its
 // bound, but at least one (!), must be in the type list of the bound of the
 // corresponding parameterized type's type parameter.
-type T1[P interface{type uint}] struct{}
+type T1[P interface{~uint}] struct{}
 
 func _[P any]() {
-    _ = T1[P /* ERROR P has no type constraints */ ]{}
+    _ = T1[P /* ERROR P has no constraints */ ]{}
 }
 
 // This is the original (simplified) program causing the same issue.
 type Unsigned interface {
-	type uint
+	~uint
 }
 
 type T2[U Unsigned] struct {
@@ -76,8 +74,8 @@ func (u T2[U]) Add1() U {
     return u.s + 1
 }
 
-func NewT2[U any]() T2[U /* ERROR U has no type constraints */ ] {
-    return T2[U /* ERROR U has no type constraints */ ]{}
+func NewT2[U any]() T2[U /* ERROR U has no constraints */ ] {
+    return T2[U /* ERROR U has no constraints */ ]{}
 }
 
 func _() {
@@ -156,7 +154,7 @@ type inf2[T any] struct{ inf2 /* ERROR illegal cycle */ [T] }
 // predicate disjunction in the implementation was wrong because if a type list
 // contains both an integer and a floating-point type, the type parameter is
 // neither an integer or a floating-point number.
-func convert[T1, T2 interface{type int, uint, float32}](v T1) T2 {
+func convert[T1, T2 interface{~int | ~uint | ~float32}](v T1) T2 {
 	return T2(v)
 }
 
@@ -168,12 +166,12 @@ func _() {
 // both numeric, or both strings. The implementation had the same problem
 // with this check as the conversion issue above (issue #39623).
 
-func issue39623[T interface{type int, string}](x, y T) T {
+func issue39623[T interface{~int | ~string}](x, y T) T {
 	return x + y
 }
 
 // Simplified, from https://go2goplay.golang.org/p/efS6x6s-9NI:
-func Sum[T interface{type int, string}](s []T) (sum T) {
+func Sum[T interface{~int | ~string}](s []T) (sum T) {
 	for _, v := range s {
 		sum += v
 	}
@@ -182,19 +180,19 @@ func Sum[T interface{type int, string}](s []T) (sum T) {
 
 // Assignability of an unnamed pointer type to a type parameter that
 // has a matching underlying type.
-func _[T interface{}, PT interface{type *T}] (x T) PT {
+func _[T interface{}, PT interface{~*T}] (x T) PT {
     return &x
 }
 
 // Indexing of generic types containing type parameters in their type list:
-func at[T interface{ type []E }, E interface{}](x T, i int) E {
+func at[T interface{ ~[]E }, E interface{}](x T, i int) E {
         return x[i]
 }
 
 // A generic type inside a function acts like a named type. Its underlying
 // type is itself, its "operational type" is defined by the type list in
 // the tybe bound, if any.
-func _[T interface{type int}](x T) {
+func _[T interface{~int}](x T) {
 	type myint int
 	var _ int = int(x)
 	var _ T = 42
@@ -203,24 +201,24 @@ func _[T interface{type int}](x T) {
 
 // Indexing a generic type with an array type bound checks length.
 // (Example by mdempsky@.)
-func _[T interface { type [10]int }](x T) {
+func _[T interface { ~[10]int }](x T) {
 	_ = x[9] // ok
 	_ = x[20 /* ERROR out of bounds */ ]
 }
 
 // Pointer indirection of a generic type.
-func _[T interface{ type *int }](p T) int {
+func _[T interface{ ~*int }](p T) int {
 	return *p
 }
 
 // Channel sends and receives on generic types.
-func _[T interface{ type chan int }](ch T) int {
+func _[T interface{ ~chan int }](ch T) int {
 	ch <- 0
 	return <- ch
 }
 
 // Calling of a generic variable.
-func _[T interface{ type func() }](f T) {
+func _[T interface{ ~func() }](f T) {
 	f()
 	go f()
 }
@@ -232,9 +230,9 @@ func _[T interface{ type func() }](f T) {
 // type parameter that was substituted with a defined type.
 // Test case from an (originally) failing example.
 
-type sliceOf[E any] interface{ type []E }
+type sliceOf[E any] interface{ ~[]E }
 
-func append[T interface{}, S sliceOf[T], T2 interface{ type T }](s S, t ...T2) S
+func append[T interface{}, S sliceOf[T], T2 interface{}](s S, t ...T2) S { panic(0) }
 
 var f           func()
 var cancelSlice []context.CancelFunc
@@ -242,7 +240,7 @@ var _ = append[context.CancelFunc, []context.CancelFunc, context.CancelFunc](can
 
 // A generic function must be instantiated with a type, not a value.
 
-func g[T any](T) T
+func g[T any](T) T { panic(0) }
 
 var _ = g[int]
 var _ = g[nil /* ERROR is not a type */ ]
diff --git a/src/cmd/compile/internal/types2/testdata/check/issues.src b/src/cmd/compile/internal/types2/testdata/check/issues.src
index 21aa208cc76..692ed37ef4b 100644
--- a/src/cmd/compile/internal/types2/testdata/check/issues.src
+++ b/src/cmd/compile/internal/types2/testdata/check/issues.src
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package issues
+package go1_17 // don't permit non-interface elements in interfaces
 
 import (
 	"fmt"
-	syn "cmd/compile/internal/syntax"
+	syn "regexp/syntax"
 	t1 "text/template"
 	t2 "html/template"
 )
@@ -329,10 +329,10 @@ func (... /* ERROR can only use ... with final parameter in list */ TT) f()
 func issue28281g() (... /* ERROR can only use ... with final parameter in list */ TT)
 
 // Issue #26234: Make various field/method lookup errors easier to read by matching cmd/compile's output
-func issue26234a(f *syn.File) {
+func issue26234a(f *syn.Prog) {
 	// The error message below should refer to the actual package name (syntax)
 	// not the local package name (syn).
-	f.foo /* ERROR f.foo undefined \(type \*syntax.File has no field or method foo\) */
+	f.foo /* ERROR f\.foo undefined \(type \*syntax\.Prog has no field or method foo\) */
 }
 
 type T struct {
@@ -357,11 +357,11 @@ func issue35895() {
 	var _ T = 0 // ERROR cannot use 0 \(untyped int constant\) as T
 
 	// There is only one package with name syntax imported, only use the (global) package name in error messages.
-	var _ *syn.File = 0 // ERROR cannot use 0 \(untyped int constant\) as \*syntax.File
+	var _ *syn.Prog = 0 // ERROR cannot use 0 \(untyped int constant\) as \*syntax.Prog
 
 	// Because both t1 and t2 have the same global package name (template),
 	// qualify packages with full path name in this case.
-	var _ t1.Template = t2 /* ERROR cannot use .* \(value of type "html/template".Template\) as "text/template".Template */ .Template{}
+	var _ t1.Template = t2 /* ERROR cannot use .* \(value of type .html/template.\.Template\) as .text/template.\.Template */ .Template{}
 }
 
 func issue42989(s uint) {
diff --git a/src/cmd/compile/internal/types2/testdata/check/linalg.go2 b/src/cmd/compile/internal/types2/testdata/check/linalg.go2
index 0d27603a583..efc090a1d1f 100644
--- a/src/cmd/compile/internal/types2/testdata/check/linalg.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/linalg.go2
@@ -9,10 +9,10 @@ import "math"
 // Numeric is type bound that matches any numeric type.
 // It would likely be in a constraints package in the standard library.
 type Numeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		complex64, complex128
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~complex64 | ~complex128
 }
 
 func DotProduct[T Numeric](s1, s2 []T) T {
@@ -42,14 +42,14 @@ func AbsDifference[T NumericAbs[T]](a, b T) T {
 
 // OrderedNumeric is a type bound that matches numeric types that support the < operator.
 type OrderedNumeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
 }
 
 // Complex is a type bound that matches the two complex types, which do not have a < operator.
 type Complex interface {
-	type complex64, complex128
+	~complex64 | ~complex128
 }
 
 // OrderedAbs is a helper type that defines an Abs method for
diff --git a/src/cmd/compile/internal/types2/testdata/check/map2.go2 b/src/cmd/compile/internal/types2/testdata/check/map2.go2
index 2833445662d..be2c49f621e 100644
--- a/src/cmd/compile/internal/types2/testdata/check/map2.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/map2.go2
@@ -114,7 +114,7 @@ func (it *Iterator[K, V]) Next() (K, V, bool) {
 
 // chans
 
-func chans_Ranger[T any]() (*chans_Sender[T], *chans_Receiver[T])
+func chans_Ranger[T any]() (*chans_Sender[T], *chans_Receiver[T]) { panic(0) }
 
 // A sender is used to send values to a Receiver.
 type chans_Sender[T any] struct {
diff --git a/src/cmd/compile/internal/types2/testdata/check/mtypeparams.go2 b/src/cmd/compile/internal/types2/testdata/check/mtypeparams.go2
index c2f282bae11..1b406593f88 100644
--- a/src/cmd/compile/internal/types2/testdata/check/mtypeparams.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/mtypeparams.go2
@@ -10,7 +10,7 @@ package p
 
 type S struct{}
 
-func (S) m[T any](v T)
+func (S) m[T any](v T) {}
 
 // TODO(gri) Once we collect interface method type parameters
 //           in the parser, we can enable these tests again.
diff --git a/src/cmd/compile/internal/types2/testdata/check/stmt0.src b/src/cmd/compile/internal/types2/testdata/check/stmt0.src
index bedcbe5fce3..d744f2ba814 100644
--- a/src/cmd/compile/internal/types2/testdata/check/stmt0.src
+++ b/src/cmd/compile/internal/types2/testdata/check/stmt0.src
@@ -49,18 +49,18 @@ func assignments1() {
 	b = true
 
 	i += 1
-	i += "foo" /* ERROR "cannot convert.*int" */
+	i += "foo" /* ERROR "mismatched types int and untyped string" */
 
 	f -= 1
 	f /= 0
 	f = float32(0)/0 /* ERROR "division by zero" */
-	f -= "foo" /* ERROR "cannot convert.*float64" */
+	f -= "foo" /* ERROR "mismatched types float64 and untyped string" */
 
 	c *= 1
 	c /= 0
 
 	s += "bar"
-	s += 1 /* ERROR "cannot convert.*string" */
+	s += 1 /* ERROR "mismatched types string and untyped int" */
 
 	var u64 uint64
 	u64 += 1< 0 {
 		x0 = x[0]
@@ -118,9 +118,9 @@ func max[T interface{ type int }](x ...T) T {
 // Thus even if a type can be inferred successfully, the function
 // call may not be valid.
 
-func fboth[T any](chan T)
-func frecv[T any](<-chan T)
-func fsend[T any](chan<- T)
+func fboth[T any](chan T) {}
+func frecv[T any](<-chan T) {}
+func fsend[T any](chan<- T) {}
 
 func _() {
 	var both chan int
@@ -140,9 +140,9 @@ func _() {
 	fsend(send)
 }
 
-func ffboth[T any](func(chan T))
-func ffrecv[T any](func(<-chan T))
-func ffsend[T any](func(chan<- T))
+func ffboth[T any](func(chan T)) {}
+func ffrecv[T any](func(<-chan T)) {}
+func ffsend[T any](func(chan<- T)) {}
 
 func _() {
 	var both func(chan int)
@@ -169,9 +169,9 @@ func _() {
 // assignment is permitted, parameter passing is permitted as well,
 // so type inference should be able to handle these cases well.
 
-func g1[T any]([]T)
-func g2[T any]([]T, T)
-func g3[T any](*T, ...T)
+func g1[T any]([]T) {}
+func g2[T any]([]T, T) {}
+func g3[T any](*T, ...T) {}
 
 func _() {
 	type intSlize []int
@@ -195,7 +195,7 @@ func _() {
 
 // Here's a realistic example.
 
-func append[T any](s []T, t ...T) []T
+func append[T any](s []T, t ...T) []T { panic(0) }
 
 func _() {
 	var f func()
@@ -208,8 +208,12 @@ func _() {
 // (that would indicate a slice type). Thus, generic functions cannot
 // have empty type parameter lists, either. This is a syntax error.
 
-func h[] /* ERROR empty type parameter list */ ()
+func h[] /* ERROR empty type parameter list */ () {}
 
 func _() {
 	h[] /* ERROR operand */ ()
 }
+
+// Parameterized functions must have a function body.
+
+func _ /* ERROR missing function body */ [P any]()
diff --git a/src/cmd/compile/internal/types2/testdata/examples/inference.go2 b/src/cmd/compile/internal/types2/testdata/examples/inference.go2
index b47ce758054..e169aec7466 100644
--- a/src/cmd/compile/internal/types2/testdata/examples/inference.go2
+++ b/src/cmd/compile/internal/types2/testdata/examples/inference.go2
@@ -7,10 +7,10 @@
 package p
 
 type Ordered interface {
-	type int, float64, string
+	~int|~float64|~string
 }
 
-func min[T Ordered](x, y T) T
+func min[T Ordered](x, y T) T { panic(0) }
 
 func _() {
 	// min can be called with explicit instantiation.
@@ -37,7 +37,7 @@ func _() {
 	_ = min("foo", "bar")
 }
 
-func mixed[T1, T2, T3 any](T1, T2, T3)
+func mixed[T1, T2, T3 any](T1, T2, T3) {}
 
 func _() {
 	// mixed can be called with explicit instantiation.
@@ -54,7 +54,7 @@ func _() {
 	mixed[int, string](1.1 /* ERROR cannot use 1.1 */ , "", false)
 }
 
-func related1[Slice interface{type []Elem}, Elem any](s Slice, e Elem)
+func related1[Slice interface{~[]Elem}, Elem any](s Slice, e Elem) {}
 
 func _() {
 	// related1 can be called with explicit instantiation.
@@ -78,7 +78,7 @@ func _() {
 	related1(si, "foo" /* ERROR cannot use "foo" */ )
 }
 
-func related2[Elem any, Slice interface{type []Elem}](e Elem, s Slice)
+func related2[Elem any, Slice interface{~[]Elem}](e Elem, s Slice) {}
 
 func _() {
 	// related2 can be called with explicit instantiation.
diff --git a/src/cmd/compile/internal/types2/testdata/examples/methods.go2 b/src/cmd/compile/internal/types2/testdata/examples/methods.go2
index 76c6539e1b7..4e87041e547 100644
--- a/src/cmd/compile/internal/types2/testdata/examples/methods.go2
+++ b/src/cmd/compile/internal/types2/testdata/examples/methods.go2
@@ -6,6 +6,8 @@
 
 package p
 
+import "unsafe"
+
 // Parameterized types may have methods.
 type T1[A any] struct{ a A }
 
@@ -94,3 +96,18 @@ func (_ T2[_, _, _]) _() int { return 42 }
 type T0 struct{}
 func (T0) _() {}
 func (T1[A]) _() {}
+
+// A generic receiver type may constrain its type parameter such
+// that it must be a pointer type. Such receiver types are not
+// permitted.
+type T3a[P interface{ ~int | ~string | ~float64 }] P
+
+func (T3a[_]) m() {} // this is ok
+
+type T3b[P interface{ ~unsafe.Pointer }] P
+
+func (T3b /* ERROR invalid receiver */ [_]) m() {}
+
+type T3c[P interface{ *int | *string }] P
+
+func (T3c /* ERROR invalid receiver */ [_]) m() {}
diff --git a/src/cmd/compile/internal/types2/testdata/examples/operations.go2 b/src/cmd/compile/internal/types2/testdata/examples/operations.go2
new file mode 100644
index 00000000000..18e4d6080c5
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/examples/operations.go2
@@ -0,0 +1,29 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// indirection
+
+func _[P any](p P) {
+        _ = *p // ERROR cannot indirect p
+}
+
+func _[P interface{ int }](p P) {
+        _ = *p // ERROR cannot indirect p
+}
+
+func _[P interface{ *int }](p P) {
+        _ = *p
+}
+
+func _[P interface{ *int | *string }](p P) {
+        _ = *p // ERROR must have identical base types
+}
+
+type intPtr *int
+
+func _[P interface{ *int | intPtr } ](p P) {
+        var _ int = *p
+}
diff --git a/src/cmd/compile/internal/types2/testdata/examples/types.go2 b/src/cmd/compile/internal/types2/testdata/examples/types.go2
index a7825ed2d9b..d662444ead8 100644
--- a/src/cmd/compile/internal/types2/testdata/examples/types.go2
+++ b/src/cmd/compile/internal/types2/testdata/examples/types.go2
@@ -155,30 +155,40 @@ type _ struct {
 	List /* ERROR List redeclared */ [int]
 }
 
+// Issue #45639: We don't allow this anymore. Keep this code
+//               in case we decide to revisit this decision.
+//
 // It's possible to declare local types whose underlying types
 // are type parameters. As with ordinary type definitions, the
 // types underlying properties are "inherited" but the methods
 // are not.
-func _[T interface{ m(); type int }]() {
-	type L T
-	var x L
+// func _[T interface{ m(); ~int }]() {
+// 	type L T
+// 	var x L
+// 
+// 	// m is not defined on L (it is not "inherited" from
+// 	// its underlying type).
+// 	x.m /* ERROR x.m undefined */ ()
+// 
+// 	// But the properties of T, such that as that it supports
+// 	// the operations of the types given by its type bound,
+// 	// are also the properties of L.
+// 	x++
+// 	_ = x - x
+// 
+// 	// On the other hand, if we define a local alias for T,
+// 	// that alias stands for T as expected.
+// 	type A = T
+// 	var y A
+// 	y.m()
+// 	_ = y < 0
+// }
 
-	// m is not defined on L (it is not "inherited" from
-	// its underlying type).
-	x.m /* ERROR x.m undefined */ ()
-
-	// But the properties of T, such that as that it supports
-	// the operations of the types given by its type bound,
-	// are also the properties of L.
-	x++
-	_ = x - x
-
-	// On the other hand, if we define a local alias for T,
-	// that alias stands for T as expected.
-	type A = T
-	var y A
-	y.m()
-	_ = y < 0
+// It is not permitted to declare a local type whose underlying
+// type is a type parameters not declared by that type declaration.
+func _[T any]() {
+	type _ T         // ERROR cannot use function type parameter T as RHS in type declaration
+	type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
 }
 
 // As a special case, an explicit type argument may be omitted
@@ -206,15 +216,15 @@ type B0 interface {}
 type B1[_ any] interface{}
 type B2[_, _ any] interface{}
 
-func _[T1 B0]()
-func _[T1 B1[T1]]()
-func _[T1 B2 /* ERROR cannot use generic type .* without instantiation */ ]()
+func _[T1 B0]() {}
+func _[T1 B1[T1]]() {}
+func _[T1 B2 /* ERROR cannot use generic type .* without instantiation */ ]() {}
 
-func _[T1, T2 B0]()
-func _[T1 B1[T1], T2 B1[T2]]()
-func _[T1, T2 B2 /* ERROR cannot use generic type .* without instantiation */ ]()
+func _[T1, T2 B0]() {}
+func _[T1 B1[T1], T2 B1[T2]]() {}
+func _[T1, T2 B2 /* ERROR cannot use generic type .* without instantiation */ ]() {}
 
-func _[T1 B0, T2 B1[T2]]() // here B1 applies to T2
+func _[T1 B0, T2 B1[T2]]() {} // here B1 applies to T2
 
 // When the type argument is left away, the type bound is
 // instantiated for each type parameter with that type
@@ -232,11 +242,11 @@ func _[A Adder[A], B Adder[B], C Adder[A]]() {
 // The type of variables (incl. parameters and return values) cannot
 // be an interface with type constraints or be/embed comparable.
 type I interface {
-	type int
+	~int
 }
 
 var (
-	_ interface /* ERROR contains type constraints */ {type int}
+	_ interface /* ERROR contains type constraints */ {~int}
 	_ I /* ERROR contains type constraints */
 )
 
@@ -267,7 +277,7 @@ func _() {
 // (If a type list contains just a single const type, we could
 // allow it, but such type lists don't make much sense in the
 // first place.)
-func _[T interface { type int, float64 }]() {
+func _[T interface{~int|~float64}]() {
 	// not valid
 	const _ = T /* ERROR not constant */ (0)
 	const _ T /* ERROR invalid constant type T */ = 1
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39634.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39634.go2
index 2c1299feb09..8d14f8acaf8 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39634.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39634.go2
@@ -31,13 +31,14 @@ type x7[A any] struct{ foo7 }
 func main7() { var _ foo7 = x7[int]{} }
 
 // crash 8
-type foo8[A any] interface { type A }
-func bar8[A foo8[A]](a A) {}
-func main8() {}
+// Embedding stand-alone type parameters is not permitted for now. Disabled.
+// type foo8[A any] interface { ~A }
+// func bar8[A foo8[A]](a A) {}
+// func main8() {}
 
 // crash 9
-type foo9[A any] interface { type foo9 /* ERROR interface contains type constraints */ [A] }
-func _() { var _ = new(foo9 /* ERROR interface contains type constraints */ [int]) }
+type foo9[A any] interface { foo9 /* ERROR illegal cycle */ [A] }
+func _() { var _ = new(foo9 /* ERROR illegal cycle */ [int]) }
 
 // crash 12
 var u /* ERROR cycle */ , i [func /* ERROR used as value */ /* ERROR used as value */ (u, c /* ERROR undeclared */ /* ERROR undeclared */ ) {}(0, len /* ERROR must be called */ /* ERROR must be called */ )]c /* ERROR undeclared */ /* ERROR undeclared */
@@ -49,7 +50,7 @@ func (G15 /* ERROR generic type .* without instantiation */ ) p()
 
 // crash 16
 type Foo16[T any] r16 /* ERROR not a type */
-func r16[T any]() Foo16[Foo16[T]]
+func r16[T any]() Foo16[Foo16[T]] { panic(0) }
 
 // crash 17
 type Y17 interface{ c() }
@@ -57,7 +58,7 @@ type Z17 interface {
 	c() Y17
 	Y17 /* ERROR duplicate method */
 }
-func F17[T Z17](T)
+func F17[T Z17](T) {}
 
 // crash 18
 type o18[T any] []func(_ o18[[]_ /* ERROR cannot use _ */ ])
@@ -87,5 +88,5 @@ type T26 = interface{ F26[ /* ERROR cannot have type parameters */ Z any]() }
 func F26[Z any]() T26 { return F26 /* ERROR without instantiation */ /* ERROR missing method */ [] /* ERROR operand */ }
 
 // crash 27
-func e27[T any]() interface{ x27 /* ERROR not a type */ }
+func e27[T any]() interface{ x27 /* ERROR not a type */ } { panic(0) }
 func x27() { e27( /* ERROR cannot infer T */ ) }
\ No newline at end of file
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39680.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39680.go2
index 9bc26f35461..e56bc354758 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39680.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39680.go2
@@ -4,16 +4,19 @@
 
 package p
 
+// Embedding stand-alone type parameters is not permitted for now. Disabled.
+
+/*
 import "fmt"
 
 // Minimal test case.
-func _[T interface{type T}](x T) T{
+func _[T interface{~T}](x T) T{
 	return x
 }
 
 // Test case from issue.
 type constr[T any] interface {
-	type T
+	~T
 }
 
 func Print[T constr[T]](s []T) {
@@ -25,3 +28,4 @@ func Print[T constr[T]](s []T) {
 func f() {
 	Print([]string{"Hello, ", "playground\n"})
 }
+*/
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39693.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39693.go2
index 316ab1982e8..301c13be41c 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39693.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39693.go2
@@ -4,11 +4,20 @@
 
 package p
 
-type Number interface {
-	int     /* ERROR int is not an interface */
-	float64 /* ERROR float64 is not an interface */
+type Number1 interface {
+	// embedding non-interface types is permitted
+	int
+	float64
 }
 
-func Add[T Number](a, b T) T {
+func Add1[T Number1](a, b T) T {
 	return a /* ERROR not defined */ + b
 }
+
+type Number2 interface {
+	int|float64
+}
+
+func Add2[T Number2](a, b T) T {
+	return a + b
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39699.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39699.go2
index 75491e7e26f..72f83997c24 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39699.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39699.go2
@@ -8,7 +8,7 @@ type T0 interface{
 }
 
 type T1 interface{
-	type int
+	~int
 }
 
 type T2 interface{
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39711.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39711.go2
index df621a4c173..85eb0a78fe2 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39711.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39711.go2
@@ -7,5 +7,7 @@ package p
 // Do not report a duplicate type error for this type list.
 // (Check types after interfaces have been completed.)
 type _ interface {
-	type interface{ Error() string }, interface{ String() string }
+	// TODO(gri) Once we have full type sets we can enable this again.
+	// Fow now we don't permit interfaces in type lists.
+	// type interface{ Error() string }, interface{ String() string }
 }
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39723.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39723.go2
index 55464e6b775..d5311ed3e75 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39723.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39723.go2
@@ -6,4 +6,4 @@ package p
 
 // A constraint must be an interface; it cannot
 // be a type parameter, for instance.
-func _[A interface{ type interface{} }, B A /* ERROR not an interface */ ]()
+func _[A interface{ ~int }, B A /* ERROR not an interface */ ]() {}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39725.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39725.go2
index e19b6770bfe..62dc45a5960 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39725.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39725.go2
@@ -4,13 +4,13 @@
 
 package p
 
-func f1[T1, T2 any](T1, T2, struct{a T1; b T2})
+func f1[T1, T2 any](T1, T2, struct{a T1; b T2}) {}
 func _() {
 	f1(42, string("foo"), struct /* ERROR does not match inferred type struct\{a int; b string\} */ {a, b int}{})
 }
 
 // simplified test case from issue
-func f2[T any](_ []T, _ func(T))
+func f2[T any](_ []T, _ func(T)) {}
 func _() {
 	f2([]string{}, func /* ERROR does not match inferred type func\(string\) */ (f []byte) {})
 }
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go2
index b7ab68818e9..257b73a2fbe 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go2
@@ -4,14 +4,14 @@
 
 package p
 
-func _[T interface{type map[string]int}](x T) {
+func _[T interface{~map[string]int}](x T) {
 	_ = x == nil
 }
 
 // simplified test case from issue
 
 type PathParamsConstraint interface {
-        type map[string]string, []struct{key, value string}
+        ~map[string]string | ~[]struct{key, value string}
 }
 
 type PathParams[T PathParamsConstraint] struct {
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39938.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39938.go2
index 76e7e369ca1..0da6e103fd1 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39938.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39938.go2
@@ -8,8 +8,8 @@ package p
 
 type E0[P any] P
 type E1[P any] *P
-type E2[P any] struct{ P }
-type E3[P any] struct{ *P }
+type E2[P any] struct{ _ P }
+type E3[P any] struct{ _ *P }
 
 type T0 /* ERROR illegal cycle */ struct {
         _ E0[T0]
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39948.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39948.go2
index c2b460902cc..e38e57268d6 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39948.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39948.go2
@@ -5,5 +5,5 @@
 package p
 
 type T[P any] interface{
-	P // ERROR P is a type parameter, not an interface
+	P // ERROR cannot embed a type parameter
 }
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39976.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39976.go2
index 3db4eae0123..d703da90a21 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39976.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue39976.go2
@@ -7,7 +7,7 @@ package p
 type policy[K, V any] interface{}
 type LRU[K, V any] struct{}
 
-func NewCache[K, V any](p policy[K, V])
+func NewCache[K, V any](p policy[K, V]) {}
 
 func _() {
 	var lru LRU[int, string]
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40038.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40038.go2
index 8948d61caa4..0981a335da3 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40038.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40038.go2
@@ -8,7 +8,7 @@ type A[T any] int
 
 func (A[T]) m(A[T])
 
-func f[P interface{m(P)}]()
+func f[P interface{m(P)}]() {}
 
 func _() {
 	_ = f[A[int]]
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40056.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40056.go2
index 747aab49dd1..a3f3eecca09 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40056.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40056.go2
@@ -10,6 +10,6 @@ func _() {
 
 type S struct {}
 
-func NewS[T any]() *S
+func NewS[T any]() *S { panic(0) }
 
 func (_ *S /* ERROR S is not a generic type */ [T]) M()
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40301.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40301.go2
index 5d97855f8a1..c78f9a1fa04 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40301.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40301.go2
@@ -7,6 +7,6 @@ package p
 import "unsafe"
 
 func _[T any](x T) {
-	_ = unsafe /* ERROR undefined */ .Alignof(x)
-	_ = unsafe /* ERROR undefined */ .Sizeof(x)
+	_ = unsafe.Alignof(x)
+	_ = unsafe.Sizeof(x)
 }
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40684.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40684.go2
index 0269c3a62ce..58d0f69f650 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40684.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40684.go2
@@ -6,8 +6,8 @@ package p
 
 type T[_ any] int
 
-func f[_ any]()
-func g[_, _ any]()
+func f[_ any]() {}
+func g[_, _ any]() {}
 
 func _() {
 	_ = f[T /* ERROR without instantiation */ ]
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40789.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40789.go2
new file mode 100644
index 00000000000..9eea4ad60a6
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue40789.go2
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+func main() {
+	m := map[string]int{
+		"a": 6,
+		"b": 7,
+	}
+	fmt.Println(copyMap[map[string]int, string, int](m))
+}
+
+type Map[K comparable, V any] interface {
+	map[K] V
+}
+
+func copyMap[M Map[K, V], K comparable, V any](m M) M {
+	m1 := make(M)
+	for k, v := range m {
+		m1[k] = v
+	}
+	return m1
+}
+
+// simpler test case from the same issue
+
+type A[X comparable] interface {
+	[]X
+}
+
+func f[B A[X], X comparable]() B {
+	return nil
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue41124.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue41124.go2
index 61f766bcbd7..4642ab60fc8 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue41124.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue41124.go2
@@ -7,7 +7,7 @@ package p
 // Test case from issue.
 
 type Nat interface {
-	type Zero, Succ
+	Zero|Succ
 }
 
 type Zero struct{}
@@ -22,7 +22,7 @@ type I1 interface {
 }
 
 type I2 interface {
-	type int
+	~int
 }
 
 type I3 interface {
@@ -47,7 +47,7 @@ type _ struct{
 }
 
 type _ struct{
-	I3 // ERROR interface contains type constraints
+	I3 // ERROR interface is .* comparable
 }
 
 // General composite types.
@@ -59,19 +59,19 @@ type (
 	_ []I1 // ERROR interface is .* comparable
 	_ []I2 // ERROR interface contains type constraints
 
-	_ *I3 // ERROR interface contains type constraints
+	_ *I3 // ERROR interface is .* comparable
 	_ map[I1 /* ERROR interface is .* comparable */ ]I2 // ERROR interface contains type constraints
-	_ chan I3 // ERROR interface contains type constraints
+	_ chan I3 // ERROR interface is .* comparable
 	_ func(I1 /* ERROR interface is .* comparable */ )
 	_ func() I2 // ERROR interface contains type constraints
 )
 
 // Other cases.
 
-var _ = [...]I3 /* ERROR interface contains type constraints */ {}
+var _ = [...]I3 /* ERROR interface is .* comparable */ {}
 
 func _(x interface{}) {
-	_ = x.(I3 /* ERROR interface contains type constraints */ )
+	_ = x.(I3 /* ERROR interface is .* comparable */ )
 }
 
 type T1[_ any] struct{}
@@ -79,9 +79,9 @@ type T3[_, _, _ any] struct{}
 var _ T1[I2 /* ERROR interface contains type constraints */ ]
 var _ T3[int, I2 /* ERROR interface contains type constraints */ , float32]
 
-func f1[_ any]() int
+func f1[_ any]() int { panic(0) }
 var _ = f1[I2 /* ERROR interface contains type constraints */ ]()
-func f3[_, _, _ any]() int
+func f3[_, _, _ any]() int { panic(0) }
 var _ = f3[int, I2 /* ERROR interface contains type constraints */ , float32]()
 
 func _(x interface{}) {
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue42758.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue42758.go2
index 698cb8a16ba..bf0031f5d24 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue42758.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue42758.go2
@@ -17,7 +17,7 @@ func _[T any](x interface{}){
 }
 
 type constraint interface {
-	type int
+	~int
 }
 
 func _[T constraint](x interface{}){
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue43671.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue43671.go2
new file mode 100644
index 00000000000..6cc3801cc96
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue43671.go2
@@ -0,0 +1,58 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | <-chan T }
+
+func _[T any](ch T) {
+	<-ch // ERROR cannot receive from non-channel
+}
+
+func _[T C0](ch T) {
+	<-ch // ERROR cannot receive from non-channel
+}
+
+func _[T C1](ch T) {
+	<-ch
+}
+
+func _[T C2](ch T) {
+	<-ch
+}
+
+func _[T C3](ch T) {
+	<-ch // ERROR channels of ch .* must have the same element type
+}
+
+func _[T C4](ch T) {
+	<-ch // ERROR cannot receive from send-only channel
+}
+
+func _[T C5[X], X any](ch T, x X) {
+	x = <-ch
+}
+
+// test case from issue, slightly modified
+type RecvChan[T any] interface {
+	~chan T | ~<-chan T
+}
+
+func _[T any, C RecvChan[T]](ch C) T {
+	return <-ch
+}
+
+func f[T any, C interface{ chan T }](ch C) T {
+	return <-ch
+}
+
+func _(ch chan int) {
+	var x int = f(ch) // test constraint type inference for this case
+	_ = x
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45548.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45548.go2
index b1e42497e85..b8ba0ad4a70 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45548.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45548.go2
@@ -4,7 +4,7 @@
 
 package p
 
-func f[F interface{type *Q}, G interface{type *R}, Q, R any](q Q, r R) {}
+func f[F interface{~*Q}, G interface{~*R}, Q, R any](q Q, r R) {}
 
 func _() {
 	f[*float64, *int](1, 2)
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45635.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45635.go2
index 65662cdc766..29379591057 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45635.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45635.go2
@@ -13,7 +13,7 @@ type N[T any] struct{}
 var _ N[] /* ERROR expecting type */
 
 type I interface {
-	type map[int]int, []int
+	~[]int
 }
 
 func _[T I](i, j int) {
@@ -27,6 +27,5 @@ func _[T I](i, j int) {
 	_ = s[i, j /* ERROR more than one index */ ]
 
 	var t T
-	// TODO(gri) fix multiple error below
-	_ = t[i, j /* ERROR more than one index */ /* ERROR more than one index */ ]
+	_ = t[i, j /* ERROR more than one index */ ]
 }
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45639.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45639.go2
new file mode 100644
index 00000000000..441fb4cb346
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45639.go2
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package P
+
+// It is not permitted to declare a local type whose underlying
+// type is a type parameters not declared by that type declaration.
+func _[T any]() {
+	type _ T         // ERROR cannot use function type parameter T as RHS in type declaration
+	type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
index 7678e348ef9..f25b9d2b266 100644
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
@@ -5,7 +5,7 @@
 package issue45985
 
 // TODO(gri): this error should be on app[int] below.
-func app[S /* ERROR "type S = S does not match" */ interface{ type []T }, T any](s S, e T) S {
+func app[S /* ERROR "type S = S does not match" */ interface{ ~[]T }, T any](s S, e T) S {
     return append(s, e)
 }
 
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46090.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46090.go2
new file mode 100644
index 00000000000..81b31974c8d
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46090.go2
@@ -0,0 +1,9 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The predeclared type comparable is not visible before Go 1.18.
+
+package go1_17
+
+type _ comparable // ERROR undeclared
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46275.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46275.go2
new file mode 100644
index 00000000000..f41ae26e4bd
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46275.go2
@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue46275
+
+type N[T any] struct {
+        *N[T]
+        t T
+}
+
+func (n *N[T]) Elem() T {
+        return n.t
+}
+
+type I interface {
+        Elem() string
+}
+
+func _() {
+        var n1 *N[string]
+        var _ I = n1
+        type NS N[string]
+        var n2 *NS
+        var _ I = n2
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46583.src b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46583.src
new file mode 100644
index 00000000000..da1f1ffbbaf
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue46583.src
@@ -0,0 +1,28 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type T1 struct{}
+func (t T1) m(int) {}
+var f1 func(T1)
+
+type T2 struct{}
+func (t T2) m(x int) {}
+var f2 func(T2)
+
+type T3 struct{}
+func (T3) m(int) {}
+var f3 func(T3)
+
+type T4 struct{}
+func (T4) m(x int) {}
+var f4 func(T4)
+
+func _() {
+	f1 = T1 /* ERROR func\(T1, int\) */ .m
+	f2 = T2 /* ERROR func\(t T2, x int\) */ .m
+	f3 = T3 /* ERROR func\(T3, int\) */ .m
+	f4 = T4 /* ERROR func\(_ T4, x int\) */ .m
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47031.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47031.go2
new file mode 100644
index 00000000000..b184f9b5b7d
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47031.go2
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type Mer interface { M() }
+
+func F[T Mer](p *T) {
+	p.M /* ERROR p\.M undefined */ ()
+}
+
+type MyMer int
+
+func (MyMer) M() {}
+
+func _() {
+	F(new(MyMer))
+	F[Mer](nil)
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47115.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47115.go2
new file mode 100644
index 00000000000..00828eb997b
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47115.go2
@@ -0,0 +1,40 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func _[T any](ch T) {
+	ch /* ERROR cannot send to non-channel */ <- 0
+}
+
+func _[T C0](ch T) {
+	ch /* ERROR cannot send to non-channel */ <- 0
+}
+
+func _[T C1](ch T) {
+	ch <- 0
+}
+
+func _[T C2](ch T) {
+	ch /* ERROR cannot send to receive-only channel */ <- 0
+}
+
+func _[T C3](ch T) {
+	ch /* ERROR channels of ch .* must have the same element type */ <- 0
+}
+
+func _[T C4](ch T) {
+	ch <- 0
+}
+
+func _[T C5[X], X any](ch T, x X) {
+	ch <- x
+}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47127.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47127.go2
new file mode 100644
index 00000000000..108d600a38a
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47127.go2
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Embedding of stand-alone type parameters is not permitted.
+
+package p
+
+type (
+        _[P any] interface{ *P | []P | chan P | map[string]P }
+        _[P any] interface{ P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+)
+
+func _[P any]() {
+        type (
+                _[P any] interface{ *P | []P | chan P | map[string]P }
+                _[P any] interface{ P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+
+                _ interface{ *P | []P | chan P | map[string]P }
+                _ interface{ P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+        )
+}
+
+func _[P any, Q interface{ *P | []P | chan P | map[string]P }]() {}
+func _[P any, Q interface{ P /* ERROR "cannot embed a type parameter" */ }]() {}
+func _[P any, Q interface{ ~P /* ERROR "cannot embed a type parameter" */ }]() {}
+func _[P any, Q interface{ int | P /* ERROR "cannot embed a type parameter" */ }]() {}
+func _[P any, Q interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }]() {}
diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47411.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47411.go2
new file mode 100644
index 00000000000..77281a19a20
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47411.go2
@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func f[_ comparable]() {}
+func g[_ interface{interface{comparable; ~int|~string}}]() {}
+
+func _[P comparable,
+        Q interface{ comparable; ~int|~string },
+        R any,                               // not comparable
+        S interface{ comparable; ~func() },  // not comparable
+]() {
+        _ = f[int]
+        _ = f[P]
+        _ = f[Q]
+        _ = f[func( /* ERROR does not satisfy comparable */ )]
+        _ = f[R /* ERROR R has no constraints */ ]
+
+        _ = g[int]
+        _ = g[P /* ERROR P has no type constraints */ ]
+        _ = g[Q]
+        _ = g[func( /* ERROR does not satisfy comparable */ )]
+        _ = g[R /* ERROR R has no constraints */ ]
+}
diff --git a/src/cmd/compile/internal/types2/tuple.go b/src/cmd/compile/internal/types2/tuple.go
new file mode 100644
index 00000000000..a3946beab57
--- /dev/null
+++ b/src/cmd/compile/internal/types2/tuple.go
@@ -0,0 +1,36 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple.
+// Tuples are used as components of signatures and to represent the type of multiple
+// assignments; they are not first class types of Go.
+type Tuple struct {
+	vars []*Var
+}
+
+// NewTuple returns a new tuple for the given variables.
+func NewTuple(x ...*Var) *Tuple {
+	if len(x) > 0 {
+		return &Tuple{vars: x}
+	}
+	// TODO(gri) Don't represent empty tuples with a (*Tuple)(nil) pointer;
+	//           it's too subtle and causes problems.
+	return nil
+}
+
+// Len returns the number variables of tuple t.
+func (t *Tuple) Len() int {
+	if t != nil {
+		return len(t.vars)
+	}
+	return 0
+}
+
+// At returns the i'th variable of tuple t.
+func (t *Tuple) At(i int) *Var { return t.vars[i] }
+
+func (t *Tuple) Underlying() Type { return t }
+func (t *Tuple) String() string   { return TypeString(t, nil) }
diff --git a/src/cmd/compile/internal/types2/type.go b/src/cmd/compile/internal/types2/type.go
index e6c260ff679..4b8642aa962 100644
--- a/src/cmd/compile/internal/types2/type.go
+++ b/src/cmd/compile/internal/types2/type.go
@@ -4,12 +4,6 @@
 
 package types2
 
-import (
-	"cmd/compile/internal/syntax"
-	"fmt"
-	"sync/atomic"
-)
-
 // A Type represents a type of Go.
 // All types implement the Type interface.
 type Type interface {
@@ -22,895 +16,55 @@ type Type interface {
 	String() string
 }
 
-// BasicKind describes the kind of basic type.
-type BasicKind int
-
-const (
-	Invalid BasicKind = iota // type is invalid
-
-	// predeclared types
-	Bool
-	Int
-	Int8
-	Int16
-	Int32
-	Int64
-	Uint
-	Uint8
-	Uint16
-	Uint32
-	Uint64
-	Uintptr
-	Float32
-	Float64
-	Complex64
-	Complex128
-	String
-	UnsafePointer
-
-	// types for untyped values
-	UntypedBool
-	UntypedInt
-	UntypedRune
-	UntypedFloat
-	UntypedComplex
-	UntypedString
-	UntypedNil
-
-	// aliases
-	Byte = Uint8
-	Rune = Int32
-)
-
-// BasicInfo is a set of flags describing properties of a basic type.
-type BasicInfo int
-
-// Properties of basic types.
-const (
-	IsBoolean BasicInfo = 1 << iota
-	IsInteger
-	IsUnsigned
-	IsFloat
-	IsComplex
-	IsString
-	IsUntyped
-
-	IsOrdered   = IsInteger | IsFloat | IsString
-	IsNumeric   = IsInteger | IsFloat | IsComplex
-	IsConstType = IsBoolean | IsNumeric | IsString
-)
-
-// A Basic represents a basic type.
-type Basic struct {
-	kind BasicKind
-	info BasicInfo
-	name string
-}
-
-// Kind returns the kind of basic type b.
-func (b *Basic) Kind() BasicKind { return b.kind }
-
-// Info returns information about properties of basic type b.
-func (b *Basic) Info() BasicInfo { return b.info }
-
-// Name returns the name of basic type b.
-func (b *Basic) Name() string { return b.name }
-
-// An Array represents an array type.
-type Array struct {
-	len  int64
-	elem Type
-}
-
-// NewArray returns a new array type for the given element type and length.
-// A negative length indicates an unknown length.
-func NewArray(elem Type, len int64) *Array { return &Array{len: len, elem: elem} }
-
-// Len returns the length of array a.
-// A negative result indicates an unknown length.
-func (a *Array) Len() int64 { return a.len }
-
-// Elem returns element type of array a.
-func (a *Array) Elem() Type { return a.elem }
-
-// A Slice represents a slice type.
-type Slice struct {
-	elem Type
-}
-
-// NewSlice returns a new slice type for the given element type.
-func NewSlice(elem Type) *Slice { return &Slice{elem: elem} }
-
-// Elem returns the element type of slice s.
-func (s *Slice) Elem() Type { return s.elem }
-
-// A Struct represents a struct type.
-type Struct struct {
-	fields []*Var
-	tags   []string // field tags; nil if there are no tags
-}
-
-// NewStruct returns a new struct with the given fields and corresponding field tags.
-// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be
-// only as long as required to hold the tag with the largest index i. Consequently,
-// if no field has a tag, tags may be nil.
-func NewStruct(fields []*Var, tags []string) *Struct {
-	var fset objset
-	for _, f := range fields {
-		if f.name != "_" && fset.insert(f) != nil {
-			panic("multiple fields with the same name")
-		}
-	}
-	if len(tags) > len(fields) {
-		panic("more tags than fields")
-	}
-	return &Struct{fields: fields, tags: tags}
-}
-
-// NumFields returns the number of fields in the struct (including blank and embedded fields).
-func (s *Struct) NumFields() int { return len(s.fields) }
-
-// Field returns the i'th field for 0 <= i < NumFields().
-func (s *Struct) Field(i int) *Var { return s.fields[i] }
-
-// Tag returns the i'th field tag for 0 <= i < NumFields().
-func (s *Struct) Tag(i int) string {
-	if i < len(s.tags) {
-		return s.tags[i]
-	}
-	return ""
-}
-
-// A Pointer represents a pointer type.
-type Pointer struct {
-	base Type // element type
-}
-
-// NewPointer returns a new pointer type for the given element (base) type.
-func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} }
-
-// Elem returns the element type for the given pointer p.
-func (p *Pointer) Elem() Type { return p.base }
-
-// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple.
-// Tuples are used as components of signatures and to represent the type of multiple
-// assignments; they are not first class types of Go.
-type Tuple struct {
-	vars []*Var
-}
-
-// NewTuple returns a new tuple for the given variables.
-func NewTuple(x ...*Var) *Tuple {
-	if len(x) > 0 {
-		return &Tuple{vars: x}
-	}
-	// TODO(gri) Don't represent empty tuples with a (*Tuple)(nil) pointer;
-	//           it's too subtle and causes problems.
-	return nil
-}
-
-// Len returns the number variables of tuple t.
-func (t *Tuple) Len() int {
-	if t != nil {
-		return len(t.vars)
-	}
-	return 0
-}
-
-// At returns the i'th variable of tuple t.
-func (t *Tuple) At(i int) *Var { return t.vars[i] }
-
-// A Signature represents a (non-builtin) function or method type.
-// The receiver is ignored when comparing signatures for identity.
-type Signature struct {
-	// We need to keep the scope in Signature (rather than passing it around
-	// and store it in the Func Object) because when type-checking a function
-	// literal we call the general type checker which returns a general Type.
-	// We then unpack the *Signature and use the scope for the literal body.
-	rparams  []*TypeName // receiver type parameters from left to right; or nil
-	tparams  []*TypeName // type parameters from left to right; or nil
-	scope    *Scope      // function scope, present for package-local signatures
-	recv     *Var        // nil if not a method
-	params   *Tuple      // (incoming) parameters from left to right; or nil
-	results  *Tuple      // (outgoing) results from left to right; or nil
-	variadic bool        // true if the last parameter's type is of the form ...T (or string, for append built-in only)
-}
-
-// NewSignature returns a new function type for the given receiver, parameters,
-// and results, either of which may be nil. If variadic is set, the function
-// is variadic, it must have at least one parameter, and the last parameter
-// must be of unnamed slice type.
-func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature {
-	if variadic {
-		n := params.Len()
-		if n == 0 {
-			panic("types2.NewSignature: variadic function must have at least one parameter")
-		}
-		if _, ok := params.At(n - 1).typ.(*Slice); !ok {
-			panic("types2.NewSignature: variadic parameter must be of unnamed slice type")
-		}
-	}
-	return &Signature{recv: recv, params: params, results: results, variadic: variadic}
-}
-
-// Recv returns the receiver of signature s (if a method), or nil if a
-// function. It is ignored when comparing signatures for identity.
-//
-// For an abstract method, Recv returns the enclosing interface either
-// as a *Named or an *Interface. Due to embedding, an interface may
-// contain methods whose receiver type is a different interface.
-func (s *Signature) Recv() *Var { return s.recv }
-
-// TParams returns the type parameters of signature s, or nil.
-func (s *Signature) TParams() []*TypeName { return s.tparams }
-
-// RParams returns the receiver type params of signature s, or nil.
-func (s *Signature) RParams() []*TypeName { return s.rparams }
-
-// SetTParams sets the type parameters of signature s.
-func (s *Signature) SetTParams(tparams []*TypeName) { s.tparams = tparams }
-
-// Params returns the parameters of signature s, or nil.
-func (s *Signature) Params() *Tuple { return s.params }
-
-// Results returns the results of signature s, or nil.
-func (s *Signature) Results() *Tuple { return s.results }
-
-// Variadic reports whether the signature s is variadic.
-func (s *Signature) Variadic() bool { return s.variadic }
-
-// A Sum represents a set of possible types.
-// Sums are currently used to represent type lists of interfaces
-// and thus the underlying types of type parameters; they are not
-// first class types of Go.
-type Sum struct {
-	types []Type // types are unique
-}
-
-// NewSum returns a new Sum type consisting of the provided
-// types if there are more than one. If there is exactly one
-// type, it returns that type. If the list of types is empty
-// the result is nil.
-func NewSum(types []Type) Type {
-	if len(types) == 0 {
-		return nil
-	}
-
-	// What should happen if types contains a sum type?
-	// Do we flatten the types list? For now we check
-	// and panic. This should not be possible for the
-	// current use case of type lists.
-	// TODO(gri) Come up with the rules for sum types.
-	for _, t := range types {
-		if _, ok := t.(*Sum); ok {
-			panic("sum type contains sum type - unimplemented")
-		}
-	}
-
-	if len(types) == 1 {
-		return types[0]
-	}
-	return &Sum{types: types}
-}
-
-// is reports whether all types in t satisfy pred.
-func (s *Sum) is(pred func(Type) bool) bool {
-	if s == nil {
-		return false
-	}
-	for _, t := range s.types {
-		if !pred(t) {
-			return false
-		}
-	}
-	return true
-}
-
-// An Interface represents an interface type.
-type Interface struct {
-	methods   []*Func // ordered list of explicitly declared methods
-	types     Type    // (possibly a Sum) type declared with a type list (TODO(gri) need better field name)
-	embeddeds []Type  // ordered list of explicitly embedded types
-
-	allMethods []*Func // ordered list of methods declared with or embedded in this interface (TODO(gri): replace with mset)
-	allTypes   Type    // intersection of all embedded and locally declared types  (TODO(gri) need better field name)
-
-	obj Object // type declaration defining this interface; or nil (for better error messages)
-}
-
-// unpack unpacks a type into a list of types.
-// TODO(gri) Try to eliminate the need for this function.
-func unpack(typ Type) []Type {
-	if typ == nil {
-		return nil
-	}
-	if sum := asSum(typ); sum != nil {
-		return sum.types
-	}
-	return []Type{typ}
-}
-
-// is reports whether interface t represents types that all satisfy pred.
-func (t *Interface) is(pred func(Type) bool) bool {
-	if t.allTypes == nil {
-		return false // we must have at least one type! (was bug)
-	}
-	for _, t := range unpack(t.allTypes) {
-		if !pred(t) {
-			return false
-		}
-	}
-	return true
-}
-
-// emptyInterface represents the empty (completed) interface
-var emptyInterface = Interface{allMethods: markComplete}
-
-// markComplete is used to mark an empty interface as completely
-// set up by setting the allMethods field to a non-nil empty slice.
-var markComplete = make([]*Func, 0)
-
-// NewInterface returns a new (incomplete) interface for the given methods and embedded types.
-// Each embedded type must have an underlying type of interface type.
-// NewInterface takes ownership of the provided methods and may modify their types by setting
-// missing receivers. To compute the method set of the interface, Complete must be called.
-//
-// Deprecated: Use NewInterfaceType instead which allows any (even non-defined) interface types
-// to be embedded. This is necessary for interfaces that embed alias type names referring to
-// non-defined (literal) interface types.
-func NewInterface(methods []*Func, embeddeds []*Named) *Interface {
-	tnames := make([]Type, len(embeddeds))
-	for i, t := range embeddeds {
-		tnames[i] = t
-	}
-	return NewInterfaceType(methods, tnames)
-}
-
-// NewInterfaceType returns a new (incomplete) interface for the given methods and embedded types.
-// Each embedded type must have an underlying type of interface type (this property is not
-// verified for defined types, which may be in the process of being set up and which don't
-// have a valid underlying type yet).
-// NewInterfaceType takes ownership of the provided methods and may modify their types by setting
-// missing receivers. To compute the method set of the interface, Complete must be called.
-func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
-	if len(methods) == 0 && len(embeddeds) == 0 {
-		return &emptyInterface
-	}
-
-	// set method receivers if necessary
-	typ := new(Interface)
-	for _, m := range methods {
-		if sig := m.typ.(*Signature); sig.recv == nil {
-			sig.recv = NewVar(m.pos, m.pkg, "", typ)
-		}
-	}
-
-	// All embedded types should be interfaces; however, defined types
-	// may not yet be fully resolved. Only verify that non-defined types
-	// are interfaces. This matches the behavior of the code before the
-	// fix for #25301 (issue #25596).
-	for _, t := range embeddeds {
-		if _, ok := t.(*Named); !ok && !IsInterface(t) {
-			panic("embedded type is not an interface")
-		}
-	}
-
-	// sort for API stability
-	sortMethods(methods)
-	sortTypes(embeddeds)
-
-	typ.methods = methods
-	typ.embeddeds = embeddeds
-	return typ
-}
-
-// NumExplicitMethods returns the number of explicitly declared methods of interface t.
-func (t *Interface) NumExplicitMethods() int { return len(t.methods) }
-
-// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods().
-// The methods are ordered by their unique Id.
-func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] }
-
-// NumEmbeddeds returns the number of embedded types in interface t.
-func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) }
-
-// Embedded returns the i'th embedded defined (*Named) type of interface t for 0 <= i < t.NumEmbeddeds().
-// The result is nil if the i'th embedded type is not a defined type.
-//
-// Deprecated: Use EmbeddedType which is not restricted to defined (*Named) types.
-func (t *Interface) Embedded(i int) *Named { tname, _ := t.embeddeds[i].(*Named); return tname }
-
-// EmbeddedType returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds().
-func (t *Interface) EmbeddedType(i int) Type { return t.embeddeds[i] }
-
-// NumMethods returns the total number of methods of interface t.
-// The interface must have been completed.
-func (t *Interface) NumMethods() int { t.assertCompleteness(); return len(t.allMethods) }
-
-func (t *Interface) assertCompleteness() {
-	if t.allMethods == nil {
-		panic("interface is incomplete")
-	}
-}
-
-// Method returns the i'th method of interface t for 0 <= i < t.NumMethods().
-// The methods are ordered by their unique Id.
-// The interface must have been completed.
-func (t *Interface) Method(i int) *Func { t.assertCompleteness(); return t.allMethods[i] }
-
-// Empty reports whether t is the empty interface.
-func (t *Interface) Empty() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		// A non-nil allTypes may still be empty and represents the bottom type.
-		return len(t.allMethods) == 0 && t.allTypes == nil
-	}
-	return !t.iterate(func(t *Interface) bool {
-		return len(t.methods) > 0 || t.types != nil
-	}, nil)
-}
-
-// HasTypeList reports whether interface t has a type list, possibly from an embedded type.
-func (t *Interface) HasTypeList() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		return t.allTypes != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		return t.types != nil
-	}, nil)
-}
-
-// IsComparable reports whether interface t is or embeds the predeclared interface "comparable".
-func (t *Interface) IsComparable() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		_, m := lookupMethod(t.allMethods, nil, "==")
-		return m != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		_, m := lookupMethod(t.methods, nil, "==")
-		return m != nil
-	}, nil)
-}
-
-// IsConstraint reports t.HasTypeList() || t.IsComparable().
-func (t *Interface) IsConstraint() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		if t.allTypes != nil {
-			return true
-		}
-		_, m := lookupMethod(t.allMethods, nil, "==")
-		return m != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		if t.types != nil {
-			return true
-		}
-		_, m := lookupMethod(t.methods, nil, "==")
-		return m != nil
-	}, nil)
-}
-
-// iterate calls f with t and then with any embedded interface of t, recursively, until f returns true.
-// iterate reports whether any call to f returned true.
-func (t *Interface) iterate(f func(*Interface) bool, seen map[*Interface]bool) bool {
-	if f(t) {
-		return true
-	}
-	for _, e := range t.embeddeds {
-		// e should be an interface but be careful (it may be invalid)
-		if e := asInterface(e); e != nil {
-			// Cyclic interfaces such as "type E interface { E }" are not permitted
-			// but they are still constructed and we need to detect such cycles.
-			if seen[e] {
-				continue
-			}
-			if seen == nil {
-				seen = make(map[*Interface]bool)
-			}
-			seen[e] = true
-			if e.iterate(f, seen) {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-// isSatisfiedBy reports whether interface t's type list is satisfied by the type typ.
-// If the type list is empty (absent), typ trivially satisfies the interface.
-// TODO(gri) This is not a great name. Eventually, we should have a more comprehensive
-//           "implements" predicate.
-func (t *Interface) isSatisfiedBy(typ Type) bool {
-	t.Complete()
-	if t.allTypes == nil {
-		return true
-	}
-	types := unpack(t.allTypes)
-	return includes(types, typ) || includes(types, under(typ))
-}
-
-// Complete computes the interface's method set. It must be called by users of
-// NewInterfaceType and NewInterface after the interface's embedded types are
-// fully defined and before using the interface type in any way other than to
-// form other types. The interface must not contain duplicate methods or a
-// panic occurs. Complete returns the receiver.
-func (t *Interface) Complete() *Interface {
-	// TODO(gri) consolidate this method with Checker.completeInterface
-	if t.allMethods != nil {
-		return t
-	}
-
-	t.allMethods = markComplete // avoid infinite recursion
-
-	var todo []*Func
-	var methods []*Func
-	var seen objset
-	addMethod := func(m *Func, explicit bool) {
-		switch other := seen.insert(m); {
-		case other == nil:
-			methods = append(methods, m)
-		case explicit:
-			panic("duplicate method " + m.name)
-		default:
-			// check method signatures after all locally embedded interfaces are computed
-			todo = append(todo, m, other.(*Func))
-		}
-	}
-
-	for _, m := range t.methods {
-		addMethod(m, true)
-	}
-
-	allTypes := t.types
-
-	for _, typ := range t.embeddeds {
-		utyp := under(typ)
-		etyp := asInterface(utyp)
-		if etyp == nil {
-			if utyp != Typ[Invalid] {
-				panic(fmt.Sprintf("%s is not an interface", typ))
-			}
-			continue
-		}
-		etyp.Complete()
-		for _, m := range etyp.allMethods {
-			addMethod(m, false)
-		}
-		allTypes = intersect(allTypes, etyp.allTypes)
-	}
-
-	for i := 0; i < len(todo); i += 2 {
-		m := todo[i]
-		other := todo[i+1]
-		if !Identical(m.typ, other.typ) {
-			panic("duplicate method " + m.name)
-		}
-	}
-
-	if methods != nil {
-		sortMethods(methods)
-		t.allMethods = methods
-	}
-	t.allTypes = allTypes
-
-	return t
-}
-
-// A Map represents a map type.
-type Map struct {
-	key, elem Type
-}
-
-// NewMap returns a new map for the given key and element types.
-func NewMap(key, elem Type) *Map {
-	return &Map{key: key, elem: elem}
-}
-
-// Key returns the key type of map m.
-func (m *Map) Key() Type { return m.key }
-
-// Elem returns the element type of map m.
-func (m *Map) Elem() Type { return m.elem }
-
-// A Chan represents a channel type.
-type Chan struct {
-	dir  ChanDir
-	elem Type
-}
-
-// A ChanDir value indicates a channel direction.
-type ChanDir int
-
-// The direction of a channel is indicated by one of these constants.
-const (
-	SendRecv ChanDir = iota
-	SendOnly
-	RecvOnly
-)
-
-// NewChan returns a new channel type for the given direction and element type.
-func NewChan(dir ChanDir, elem Type) *Chan {
-	return &Chan{dir: dir, elem: elem}
-}
-
-// Dir returns the direction of channel c.
-func (c *Chan) Dir() ChanDir { return c.dir }
-
-// Elem returns the element type of channel c.
-func (c *Chan) Elem() Type { return c.elem }
-
-// TODO(gri) Clean up Named struct below; specifically the fromRHS field (can we use underlying?).
-
-// A Named represents a named (defined) type.
-type Named struct {
-	check      *Checker    // for Named.under implementation
-	info       typeInfo    // for cycle detection
-	obj        *TypeName   // corresponding declared object
-	orig       *Named      // original, uninstantiated type
-	fromRHS    Type        // type (on RHS of declaration) this *Named type is derived from (for cycle reporting)
-	underlying Type        // possibly a *Named during setup; never a *Named once set up completely
-	tparams    []*TypeName // type parameters, or nil
-	targs      []Type      // type arguments (after instantiation), or nil
-	methods    []*Func     // methods declared for this type (not the method set of this type); signatures are type-checked lazily
-}
-
-// NewNamed returns a new named type for the given type name, underlying type, and associated methods.
-// If the given type name obj doesn't have a type yet, its type is set to the returned named type.
-// The underlying type must not be a *Named.
-func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
-	if _, ok := underlying.(*Named); ok {
-		panic("types2.NewNamed: underlying type must not be *Named")
-	}
-	return (*Checker)(nil).newNamed(obj, nil, underlying, nil, methods)
-}
-
-// newNamed is like NewNamed but with a *Checker receiver and additional orig argument.
-func (check *Checker) newNamed(obj *TypeName, orig *Named, underlying Type, tparams []*TypeName, methods []*Func) *Named {
-	typ := &Named{check: check, obj: obj, orig: orig, fromRHS: underlying, underlying: underlying, tparams: tparams, methods: methods}
-	if typ.orig == nil {
-		typ.orig = typ
-	}
-	if obj.typ == nil {
-		obj.typ = typ
-	}
-	return typ
-}
-
-// Obj returns the type name for the named type t.
-func (t *Named) Obj() *TypeName { return t.obj }
-
-// Orig returns the original generic type an instantiated type is derived from.
-// If t is not an instantiated type, the result is t.
-func (t *Named) Orig() *Named { return t.orig }
-
-// TODO(gri) Come up with a better representation and API to distinguish
-//           between parameterized instantiated and non-instantiated types.
-
-// TParams returns the type parameters of the named type t, or nil.
-// The result is non-nil for an (originally) parameterized type even if it is instantiated.
-func (t *Named) TParams() []*TypeName { return t.tparams }
-
-// SetTParams sets the type parameters of the named type t.
-func (t *Named) SetTParams(tparams []*TypeName) { t.tparams = tparams }
-
-// TArgs returns the type arguments after instantiation of the named type t, or nil if not instantiated.
-func (t *Named) TArgs() []Type { return t.targs }
-
-// SetTArgs sets the type arguments of the named type t.
-func (t *Named) SetTArgs(args []Type) { t.targs = args }
-
-// NumMethods returns the number of explicit methods whose receiver is named type t.
-func (t *Named) NumMethods() int { return len(t.methods) }
-
-// Method returns the i'th method of named type t for 0 <= i < t.NumMethods().
-func (t *Named) Method(i int) *Func { return t.methods[i] }
-
-// SetUnderlying sets the underlying type and marks t as complete.
-func (t *Named) SetUnderlying(underlying Type) {
-	if underlying == nil {
-		panic("types2.Named.SetUnderlying: underlying type must not be nil")
-	}
-	if _, ok := underlying.(*Named); ok {
-		panic("types2.Named.SetUnderlying: underlying type must not be *Named")
-	}
-	t.underlying = underlying
-}
-
-// AddMethod adds method m unless it is already in the method list.
-func (t *Named) AddMethod(m *Func) {
-	if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 {
-		t.methods = append(t.methods, m)
-	}
-}
-
-// Note: This is a uint32 rather than a uint64 because the
-// respective 64 bit atomic instructions are not available
-// on all platforms.
-var lastId uint32
-
-// nextId returns a value increasing monotonically by 1 with
-// each call, starting with 1. It may be called concurrently.
-func nextId() uint64 { return uint64(atomic.AddUint32(&lastId, 1)) }
-
-// A TypeParam represents a type parameter type.
-type TypeParam struct {
-	check *Checker  // for lazy type bound completion
-	id    uint64    // unique id, for debugging only
-	obj   *TypeName // corresponding type name
-	index int       // type parameter index in source order, starting at 0
-	bound Type      // *Named or *Interface; underlying type is always *Interface
-}
-
-// Obj returns the type name for the type parameter t.
-func (t *TypeParam) Obj() *TypeName { return t.obj }
-
-// NewTypeParam returns a new TypeParam.
-func (check *Checker) NewTypeParam(obj *TypeName, index int, bound Type) *TypeParam {
-	assert(bound != nil)
-	typ := &TypeParam{check: check, id: nextId(), obj: obj, index: index, bound: bound}
-	if obj.typ == nil {
-		obj.typ = typ
-	}
-	return typ
-}
-
-func (t *TypeParam) Bound() *Interface {
-	iface := asInterface(t.bound)
-	// use the type bound position if we have one
-	pos := nopos
-	if n, _ := t.bound.(*Named); n != nil {
-		pos = n.obj.pos
-	}
-	// TODO(gri) switch this to an unexported method on Checker.
-	t.check.completeInterface(pos, iface)
-	return iface
-}
-
-// optype returns a type's operational type. Except for
-// type parameters, the operational type is the same
-// as the underlying type (as returned by under). For
-// Type parameters, the operational type is determined
-// by the corresponding type bound's type list. The
-// result may be the bottom or top type, but it is never
-// the incoming type parameter.
-func optype(typ Type) Type {
-	if t := asTypeParam(typ); t != nil {
-		// If the optype is typ, return the top type as we have
-		// no information. It also prevents infinite recursion
-		// via the asTypeParam converter function. This can happen
-		// for a type parameter list of the form:
-		// (type T interface { type T }).
-		// See also issue #39680.
-		if u := t.Bound().allTypes; u != nil && u != typ {
-			// u != typ and u is a type parameter => under(u) != typ, so this is ok
-			return under(u)
-		}
-		return theTop
-	}
-	return under(typ)
-}
-
-// An instance represents an instantiated generic type syntactically
-// (without expanding the instantiation). Type instances appear only
-// during type-checking and are replaced by their fully instantiated
-// (expanded) types before the end of type-checking.
-type instance struct {
-	check   *Checker     // for lazy instantiation
-	pos     syntax.Pos   // position of type instantiation; for error reporting only
-	base    *Named       // parameterized type to be instantiated
-	targs   []Type       // type arguments
-	poslist []syntax.Pos // position of each targ; for error reporting only
-	value   Type         // base(targs...) after instantiation or Typ[Invalid]; nil if not yet set
-}
-
-// expand returns the instantiated (= expanded) type of t.
-// The result is either an instantiated *Named type, or
-// Typ[Invalid] if there was an error.
-func (t *instance) expand() Type {
-	v := t.value
-	if v == nil {
-		v = t.check.instantiate(t.pos, t.base, t.targs, t.poslist)
-		if v == nil {
-			v = Typ[Invalid]
-		}
-		t.value = v
-	}
-	// After instantiation we must have an invalid or a *Named type.
-	if debug && v != Typ[Invalid] {
-		_ = v.(*Named)
-	}
-	return v
-}
-
-// expand expands a type instance into its instantiated
-// type and leaves all other types alone. expand does
-// not recurse.
-func expand(typ Type) Type {
-	if t, _ := typ.(*instance); t != nil {
-		return t.expand()
-	}
-	return typ
-}
-
-// expandf is set to expand.
-// Call expandf when calling expand causes compile-time cycle error.
-var expandf func(Type) Type
-
-func init() { expandf = expand }
-
-// bottom represents the bottom of the type lattice.
-// It is the underlying type of a type parameter that
-// cannot be satisfied by any type, usually because
-// the intersection of type constraints left nothing).
-type bottom struct{}
-
-// theBottom is the singleton bottom type.
-var theBottom = &bottom{}
-
 // top represents the top of the type lattice.
 // It is the underlying type of a type parameter that
 // can be satisfied by any type (ignoring methods),
-// usually because the type constraint has no type
-// list.
+// because its type constraint contains no restrictions
+// besides methods.
 type top struct{}
 
 // theTop is the singleton top type.
 var theTop = &top{}
 
-// Type-specific implementations of Underlying.
-func (t *Basic) Underlying() Type     { return t }
-func (t *Array) Underlying() Type     { return t }
-func (t *Slice) Underlying() Type     { return t }
-func (t *Struct) Underlying() Type    { return t }
-func (t *Pointer) Underlying() Type   { return t }
-func (t *Tuple) Underlying() Type     { return t }
-func (t *Signature) Underlying() Type { return t }
-func (t *Sum) Underlying() Type       { return t }
-func (t *Interface) Underlying() Type { return t }
-func (t *Map) Underlying() Type       { return t }
-func (t *Chan) Underlying() Type      { return t }
-func (t *Named) Underlying() Type     { return t.underlying }
-func (t *TypeParam) Underlying() Type { return t }
-func (t *instance) Underlying() Type  { return t }
-func (t *bottom) Underlying() Type    { return t }
-func (t *top) Underlying() Type       { return t }
-
-// Type-specific implementations of String.
-func (t *Basic) String() string     { return TypeString(t, nil) }
-func (t *Array) String() string     { return TypeString(t, nil) }
-func (t *Slice) String() string     { return TypeString(t, nil) }
-func (t *Struct) String() string    { return TypeString(t, nil) }
-func (t *Pointer) String() string   { return TypeString(t, nil) }
-func (t *Tuple) String() string     { return TypeString(t, nil) }
-func (t *Signature) String() string { return TypeString(t, nil) }
-func (t *Sum) String() string       { return TypeString(t, nil) }
-func (t *Interface) String() string { return TypeString(t, nil) }
-func (t *Map) String() string       { return TypeString(t, nil) }
-func (t *Chan) String() string      { return TypeString(t, nil) }
-func (t *Named) String() string     { return TypeString(t, nil) }
-func (t *TypeParam) String() string { return TypeString(t, nil) }
-func (t *instance) String() string  { return TypeString(t, nil) }
-func (t *bottom) String() string    { return TypeString(t, nil) }
-func (t *top) String() string       { return TypeString(t, nil) }
+func (t *top) Underlying() Type { return t }
+func (t *top) String() string   { return TypeString(t, nil) }
 
 // under returns the true expanded underlying type.
 // If it doesn't exist, the result is Typ[Invalid].
 // under must only be called when a type is known
 // to be fully set up.
 func under(t Type) Type {
-	// TODO(gri) is this correct for *Sum?
+	// TODO(gri) is this correct for *Union?
 	if n := asNamed(t); n != nil {
 		return n.under()
 	}
 	return t
 }
 
+// optype returns a type's operational type. Except for
+// type parameters, the operational type is the same
+// as the underlying type (as returned by under). For
+// Type parameters, the operational type is the structural
+// type, if any; otherwise it's the top type.
+// The result is never the incoming type parameter.
+func optype(typ Type) Type {
+	if t := asTypeParam(typ); t != nil {
+		// TODO(gri) review accuracy of this comment
+		// If the optype is typ, return the top type as we have
+		// no information. It also prevents infinite recursion
+		// via the asTypeParam converter function. This can happen
+		// for a type parameter list of the form:
+		// (type T interface { type T }).
+		// See also issue #39680.
+		if u := t.structuralType(); u != nil {
+			assert(u != typ) // "naked" type parameters cannot be embedded
+			return u
+		}
+		return theTop
+	}
+	return under(typ)
+}
+
 // Converters
 //
 // A converter must only be called when a type is
@@ -944,39 +98,26 @@ func asPointer(t Type) *Pointer {
 	return op
 }
 
-// asTuple is not needed - not provided
-
 func asSignature(t Type) *Signature {
 	op, _ := optype(t).(*Signature)
 	return op
 }
 
-func asSum(t Type) *Sum {
-	op, _ := optype(t).(*Sum)
-	return op
-}
-
-func asInterface(t Type) *Interface {
-	op, _ := optype(t).(*Interface)
-	return op
-}
-
-func asMap(t Type) *Map {
-	op, _ := optype(t).(*Map)
-	return op
-}
-
-func asChan(t Type) *Chan {
-	op, _ := optype(t).(*Chan)
-	return op
-}
-
-// If the argument to asNamed and asTypeParam is of the respective types
+// If the argument to asInterface, asNamed, or asTypeParam is of the respective type
 // (possibly after expanding an instance type), these methods return that type.
 // Otherwise the result is nil.
 
+// asInterface does not need to look at optype (type sets don't contain interfaces)
+func asInterface(t Type) *Interface {
+	u, _ := under(t).(*Interface)
+	return u
+}
+
 func asNamed(t Type) *Named {
-	e, _ := expand(t).(*Named)
+	e, _ := t.(*Named)
+	if e != nil {
+		e.expand(nil)
+	}
 	return e
 }
 
@@ -991,3 +132,4 @@ func AsPointer(t Type) *Pointer     { return asPointer(t) }
 func AsNamed(t Type) *Named         { return asNamed(t) }
 func AsSignature(t Type) *Signature { return asSignature(t) }
 func AsInterface(t Type) *Interface { return asInterface(t) }
+func AsTypeParam(t Type) *TypeParam { return asTypeParam(t) }
diff --git a/src/cmd/compile/internal/types2/typeparam.go b/src/cmd/compile/internal/types2/typeparam.go
new file mode 100644
index 00000000000..f666fae7ede
--- /dev/null
+++ b/src/cmd/compile/internal/types2/typeparam.go
@@ -0,0 +1,143 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import "sync/atomic"
+
+// Note: This is a uint32 rather than a uint64 because the
+// respective 64 bit atomic instructions are not available
+// on all platforms.
+var lastID uint32
+
+// nextID returns a value increasing monotonically by 1 with
+// each call, starting with 1. It may be called concurrently.
+func nextID() uint64 { return uint64(atomic.AddUint32(&lastID, 1)) }
+
+// A TypeParam represents a type parameter type.
+type TypeParam struct {
+	check *Checker  // for lazy type bound completion
+	id    uint64    // unique id, for debugging only
+	obj   *TypeName // corresponding type name
+	index int       // type parameter index in source order, starting at 0
+	// TODO(rfindley): this could also be Typ[Invalid]. Verify that this is handled correctly.
+	bound Type // *Named or *Interface; underlying type is always *Interface
+}
+
+// Obj returns the type name for the type parameter t.
+func (t *TypeParam) Obj() *TypeName { return t.obj }
+
+// NewTypeParam returns a new TypeParam. Type parameters may be set on a Named
+// or Signature type by calling SetTParams. Setting a type parameter on more
+// than one type will result in a panic.
+//
+// The bound argument can be nil, and set later via SetBound.
+func (check *Checker) NewTypeParam(obj *TypeName, bound Type) *TypeParam {
+	// Always increment lastID, even if it is not used.
+	id := nextID()
+	if check != nil {
+		check.nextID++
+		id = check.nextID
+	}
+	typ := &TypeParam{check: check, id: id, obj: obj, index: -1, bound: bound}
+	if obj.typ == nil {
+		obj.typ = typ
+	}
+	return typ
+}
+
+// Index returns the index of the type param within its param list.
+func (t *TypeParam) Index() int {
+	return t.index
+}
+
+// SetId sets the unique id of a type param. Should only be used for type params
+// in imported generic types.
+func (t *TypeParam) SetId(id uint64) {
+	t.id = id
+}
+
+// Constraint returns the type constraint specified for t.
+func (t *TypeParam) Constraint() Type {
+	// compute the type set if possible (we may not have an interface)
+	if iface, _ := under(t.bound).(*Interface); iface != nil {
+		// use the type bound position if we have one
+		pos := nopos
+		if n, _ := t.bound.(*Named); n != nil {
+			pos = n.obj.pos
+		}
+		computeInterfaceTypeSet(t.check, pos, iface)
+	}
+	return t.bound
+}
+
+// SetConstraint sets the type constraint for t.
+func (t *TypeParam) SetConstraint(bound Type) {
+	if bound == nil {
+		panic("nil constraint")
+	}
+	t.bound = bound
+}
+
+func (t *TypeParam) Underlying() Type { return t }
+func (t *TypeParam) String() string   { return TypeString(t, nil) }
+
+// TParamList holds a list of type parameters bound to a type.
+type TParamList struct{ tparams []*TypeName }
+
+// Len returns the number of type parameters in the list.
+// It is safe to call on a nil receiver.
+func (tps *TParamList) Len() int {
+	return len(tps.list())
+}
+
+// At returns the i'th type parameter in the list.
+func (tps *TParamList) At(i int) *TypeName {
+	return tps.list()[i]
+}
+
+func (tps *TParamList) list() []*TypeName {
+	if tps == nil {
+		return nil
+	}
+	return tps.tparams
+}
+
+func bindTParams(list []*TypeName) *TParamList {
+	if len(list) == 0 {
+		return nil
+	}
+	for i, tp := range list {
+		typ := tp.Type().(*TypeParam)
+		if typ.index >= 0 {
+			panic("type parameter bound more than once")
+		}
+		typ.index = i
+	}
+	return &TParamList{tparams: list}
+}
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// iface returns the constraint interface of t.
+func (t *TypeParam) iface() *Interface {
+	if iface, _ := under(t.Constraint()).(*Interface); iface != nil {
+		return iface
+	}
+	return &emptyInterface
+}
+
+// structuralType returns the structural type of the type parameter's constraint; or nil.
+func (t *TypeParam) structuralType() Type {
+	return t.iface().typeSet().structuralType()
+}
+
+func (t *TypeParam) is(f func(*term) bool) bool {
+	return t.iface().typeSet().is(f)
+}
+
+func (t *TypeParam) underIs(f func(Type) bool) bool {
+	return t.iface().typeSet().underIs(f)
+}
diff --git a/src/cmd/compile/internal/types2/types_test.go b/src/cmd/compile/internal/types2/types_test.go
index 096402148d3..1525844f2df 100644
--- a/src/cmd/compile/internal/types2/types_test.go
+++ b/src/cmd/compile/internal/types2/types_test.go
@@ -4,14 +4,9 @@
 
 package types2
 
-import "sync/atomic"
-
 func init() {
 	acceptMethodTypeParams = true
 }
 
-// Upon calling ResetId, nextId starts with 1 again.
-// It may be called concurrently. This is only needed
-// for tests where we may want to have a consistent
-// numbering for each individual test case.
-func ResetId() { atomic.StoreUint32(&lastId, 0) }
+// Debug is set if types2 is built with debug mode enabled.
+const Debug = debug
diff --git a/src/cmd/compile/internal/types2/typeset.go b/src/cmd/compile/internal/types2/typeset.go
new file mode 100644
index 00000000000..5955bbe8054
--- /dev/null
+++ b/src/cmd/compile/internal/types2/typeset.go
@@ -0,0 +1,392 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"bytes"
+	"cmd/compile/internal/syntax"
+	"fmt"
+	"sort"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A TypeSet represents the type set of an interface.
+type TypeSet struct {
+	comparable bool // if set, the interface is or embeds comparable
+	// TODO(gri) consider using a set for the methods for faster lookup
+	methods []*Func  // all methods of the interface; sorted by unique ID
+	terms   termlist // type terms of the type set
+}
+
+// IsEmpty reports whether type set s is the empty set.
+func (s *TypeSet) IsEmpty() bool { return s.terms.isEmpty() }
+
+// IsAll reports whether type set s is the set of all types (corresponding to the empty interface).
+func (s *TypeSet) IsAll() bool {
+	return !s.comparable && len(s.methods) == 0 && s.terms.isAll()
+}
+
+// TODO(gri) IsMethodSet is not a great name for this predicate. Find a better one.
+
+// IsMethodSet reports whether the type set s is described by a single set of methods.
+func (s *TypeSet) IsMethodSet() bool { return !s.comparable && s.terms.isAll() }
+
+// IsComparable reports whether each type in the set is comparable.
+func (s *TypeSet) IsComparable() bool {
+	if s.terms.isAll() {
+		return s.comparable
+	}
+	return s.is(func(t *term) bool {
+		return Comparable(t.typ)
+	})
+}
+
+// TODO(gri) IsTypeSet is not a great name for this predicate. Find a better one.
+
+// IsTypeSet reports whether the type set s is represented by a finite set of underlying types.
+func (s *TypeSet) IsTypeSet() bool {
+	return !s.comparable && len(s.methods) == 0
+}
+
+// NumMethods returns the number of methods available.
+func (s *TypeSet) NumMethods() int { return len(s.methods) }
+
+// Method returns the i'th method of type set s for 0 <= i < s.NumMethods().
+// The methods are ordered by their unique ID.
+func (s *TypeSet) Method(i int) *Func { return s.methods[i] }
+
+// LookupMethod returns the index of and method with matching package and name, or (-1, nil).
+func (s *TypeSet) LookupMethod(pkg *Package, name string) (int, *Func) {
+	// TODO(gri) s.methods is sorted - consider binary search
+	return lookupMethod(s.methods, pkg, name)
+}
+
+func (s *TypeSet) String() string {
+	switch {
+	case s.IsEmpty():
+		return "∅"
+	case s.IsAll():
+		return "𝓤"
+	}
+
+	hasMethods := len(s.methods) > 0
+	hasTerms := s.hasTerms()
+
+	var buf bytes.Buffer
+	buf.WriteByte('{')
+	if s.comparable {
+		buf.WriteString(" comparable")
+		if hasMethods || hasTerms {
+			buf.WriteByte(';')
+		}
+	}
+	for i, m := range s.methods {
+		if i > 0 {
+			buf.WriteByte(';')
+		}
+		buf.WriteByte(' ')
+		buf.WriteString(m.String())
+	}
+	if hasMethods && hasTerms {
+		buf.WriteByte(';')
+	}
+	if hasTerms {
+		buf.WriteString(s.terms.String())
+	}
+	buf.WriteString(" }") // there was at least one method or term
+
+	return buf.String()
+}
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (s *TypeSet) hasTerms() bool             { return !s.terms.isAll() }
+func (s *TypeSet) structuralType() Type       { return s.terms.structuralType() }
+func (s *TypeSet) includes(t Type) bool       { return s.terms.includes(t) }
+func (s1 *TypeSet) subsetOf(s2 *TypeSet) bool { return s1.terms.subsetOf(s2.terms) }
+
+// TODO(gri) TypeSet.is and TypeSet.underIs should probably also go into termlist.go
+
+var topTerm = term{false, theTop}
+
+func (s *TypeSet) is(f func(*term) bool) bool {
+	if len(s.terms) == 0 {
+		return false
+	}
+	for _, t := range s.terms {
+		// Terms represent the top term with a nil type.
+		// The rest of the type checker uses the top type
+		// instead. Convert.
+		// TODO(gri) investigate if we can do without this
+		if t.typ == nil {
+			t = &topTerm
+		}
+		if !f(t) {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *TypeSet) underIs(f func(Type) bool) bool {
+	if len(s.terms) == 0 {
+		return false
+	}
+	for _, t := range s.terms {
+		// see corresponding comment in TypeSet.is
+		u := t.typ
+		if u == nil {
+			u = theTop
+		}
+		// t == under(t) for ~t terms
+		if !t.tilde {
+			u = under(u)
+		}
+		if debug {
+			assert(Identical(u, under(u)))
+		}
+		if !f(u) {
+			return false
+		}
+	}
+	return true
+}
+
+// topTypeSet may be used as type set for the empty interface.
+var topTypeSet = TypeSet{terms: allTermlist}
+
+// computeInterfaceTypeSet may be called with check == nil.
+func computeInterfaceTypeSet(check *Checker, pos syntax.Pos, ityp *Interface) *TypeSet {
+	if ityp.tset != nil {
+		return ityp.tset
+	}
+
+	// If the interface is not fully set up yet, the type set will
+	// not be complete, which may lead to errors when using the the
+	// type set (e.g. missing method). Don't compute a partial type
+	// set (and don't store it!), so that we still compute the full
+	// type set eventually. Instead, return the top type set and
+	// let any follow-on errors play out.
+	if !ityp.complete {
+		return &topTypeSet
+	}
+
+	if check != nil && check.conf.Trace {
+		// Types don't generally have position information.
+		// If we don't have a valid pos provided, try to use
+		// one close enough.
+		if !pos.IsKnown() && len(ityp.methods) > 0 {
+			pos = ityp.methods[0].pos
+		}
+
+		check.trace(pos, "type set for %s", ityp)
+		check.indent++
+		defer func() {
+			check.indent--
+			check.trace(pos, "=> %s ", ityp.typeSet())
+		}()
+	}
+
+	// An infinitely expanding interface (due to a cycle) is detected
+	// elsewhere (Checker.validType), so here we simply assume we only
+	// have valid interfaces. Mark the interface as complete to avoid
+	// infinite recursion if the validType check occurs later for some
+	// reason.
+	ityp.tset = &TypeSet{terms: allTermlist} // TODO(gri) is this sufficient?
+
+	// Methods of embedded interfaces are collected unchanged; i.e., the identity
+	// of a method I.m's Func Object of an interface I is the same as that of
+	// the method m in an interface that embeds interface I. On the other hand,
+	// if a method is embedded via multiple overlapping embedded interfaces, we
+	// don't provide a guarantee which "original m" got chosen for the embedding
+	// interface. See also issue #34421.
+	//
+	// If we don't care to provide this identity guarantee anymore, instead of
+	// reusing the original method in embeddings, we can clone the method's Func
+	// Object and give it the position of a corresponding embedded interface. Then
+	// we can get rid of the mpos map below and simply use the cloned method's
+	// position.
+
+	var todo []*Func
+	var seen objset
+	var methods []*Func
+	mpos := make(map[*Func]syntax.Pos) // method specification or method embedding position, for good error messages
+	addMethod := func(pos syntax.Pos, m *Func, explicit bool) {
+		switch other := seen.insert(m); {
+		case other == nil:
+			methods = append(methods, m)
+			mpos[m] = pos
+		case explicit:
+			if check == nil {
+				panic(fmt.Sprintf("%s: duplicate method %s", m.pos, m.name))
+			}
+			// check != nil
+			var err error_
+			err.errorf(pos, "duplicate method %s", m.name)
+			err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
+			check.report(&err)
+		default:
+			// We have a duplicate method name in an embedded (not explicitly declared) method.
+			// Check method signatures after all types are computed (issue #33656).
+			// If we're pre-go1.14 (overlapping embeddings are not permitted), report that
+			// error here as well (even though we could do it eagerly) because it's the same
+			// error message.
+			if check == nil {
+				// check method signatures after all locally embedded interfaces are computed
+				todo = append(todo, m, other.(*Func))
+				break
+			}
+			// check != nil
+			check.later(func() {
+				if !check.allowVersion(m.pkg, 1, 14) || !Identical(m.typ, other.Type()) {
+					var err error_
+					err.errorf(pos, "duplicate method %s", m.name)
+					err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
+					check.report(&err)
+				}
+			})
+		}
+	}
+
+	for _, m := range ityp.methods {
+		addMethod(m.pos, m, true)
+	}
+
+	// collect embedded elements
+	var allTerms = allTermlist
+	for i, typ := range ityp.embeddeds {
+		// The embedding position is nil for imported interfaces
+		// and also for interface copies after substitution (but
+		// in that case we don't need to report errors again).
+		var pos syntax.Pos // embedding position
+		if ityp.embedPos != nil {
+			pos = (*ityp.embedPos)[i]
+		}
+		var terms termlist
+		switch u := under(typ).(type) {
+		case *Interface:
+			tset := computeInterfaceTypeSet(check, pos, u)
+			if tset.comparable {
+				ityp.tset.comparable = true
+			}
+			for _, m := range tset.methods {
+				addMethod(pos, m, false) // use embedding position pos rather than m.pos
+			}
+			terms = tset.terms
+		case *Union:
+			tset := computeUnionTypeSet(check, pos, u)
+			if tset == &invalidTypeSet {
+				continue // ignore invalid unions
+			}
+			terms = tset.terms
+		case *TypeParam:
+			// Embedding stand-alone type parameters is not permitted.
+			// This case is handled during union parsing.
+			unreachable()
+		default:
+			if typ == Typ[Invalid] {
+				continue
+			}
+			if check != nil && !check.allowVersion(check.pkg, 1, 18) {
+				check.errorf(pos, "%s is not an interface", typ)
+				continue
+			}
+			terms = termlist{{false, typ}}
+		}
+		// The type set of an interface is the intersection
+		// of the type sets of all its elements.
+		// Intersection cannot produce longer termlists and
+		// thus cannot overflow.
+		allTerms = allTerms.intersect(terms)
+	}
+	ityp.embedPos = nil // not needed anymore (errors have been reported)
+
+	// process todo's (this only happens if check == nil)
+	for i := 0; i < len(todo); i += 2 {
+		m := todo[i]
+		other := todo[i+1]
+		if !Identical(m.typ, other.typ) {
+			panic(fmt.Sprintf("%s: duplicate method %s", m.pos, m.name))
+		}
+	}
+
+	if methods != nil {
+		sortMethods(methods)
+		ityp.tset.methods = methods
+	}
+	ityp.tset.terms = allTerms
+
+	return ityp.tset
+}
+
+func sortMethods(list []*Func) {
+	sort.Sort(byUniqueMethodName(list))
+}
+
+func assertSortedMethods(list []*Func) {
+	if !debug {
+		panic("assertSortedMethods called outside debug mode")
+	}
+	if !sort.IsSorted(byUniqueMethodName(list)) {
+		panic("methods not sorted")
+	}
+}
+
+// byUniqueMethodName method lists can be sorted by their unique method names.
+type byUniqueMethodName []*Func
+
+func (a byUniqueMethodName) Len() int           { return len(a) }
+func (a byUniqueMethodName) Less(i, j int) bool { return a[i].less(&a[j].object) }
+func (a byUniqueMethodName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+// invalidTypeSet is a singleton type set to signal an invalid type set
+// due to an error. It's also a valid empty type set, so consumers of
+// type sets may choose to ignore it.
+var invalidTypeSet TypeSet
+
+// computeUnionTypeSet may be called with check == nil.
+// The result is &invalidTypeSet if the union overflows.
+func computeUnionTypeSet(check *Checker, pos syntax.Pos, utyp *Union) *TypeSet {
+	if utyp.tset != nil {
+		return utyp.tset
+	}
+
+	// avoid infinite recursion (see also computeInterfaceTypeSet)
+	utyp.tset = new(TypeSet)
+
+	var allTerms termlist
+	for _, t := range utyp.terms {
+		var terms termlist
+		switch u := under(t.typ).(type) {
+		case *Interface:
+			terms = computeInterfaceTypeSet(check, pos, u).terms
+		case *TypeParam:
+			// A stand-alone type parameters is not permitted as union term.
+			// This case is handled during union parsing.
+			unreachable()
+		default:
+			if t.typ == Typ[Invalid] {
+				continue
+			}
+			terms = termlist{(*term)(t)}
+		}
+		// The type set of a union expression is the union
+		// of the type sets of each term.
+		allTerms = allTerms.union(terms)
+		if len(allTerms) > maxTermCount {
+			if check != nil {
+				check.errorf(pos, "cannot handle more than %d union terms (implementation limitation)", maxTermCount)
+			}
+			utyp.tset = &invalidTypeSet
+			return utyp.tset
+		}
+	}
+	utyp.tset.terms = allTerms
+
+	return utyp.tset
+}
diff --git a/src/cmd/compile/internal/types2/typeset_test.go b/src/cmd/compile/internal/types2/typeset_test.go
new file mode 100644
index 00000000000..0e14d523c8b
--- /dev/null
+++ b/src/cmd/compile/internal/types2/typeset_test.go
@@ -0,0 +1,15 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import "testing"
+
+func TestInvalidTypeSet(t *testing.T) {
+	if !invalidTypeSet.IsEmpty() {
+		t.Error("invalidTypeSet is not empty")
+	}
+}
+
+// TODO(gri) add more tests
diff --git a/src/cmd/compile/internal/types2/typestring.go b/src/cmd/compile/internal/types2/typestring.go
index 40016697b7c..cb7cf73a629 100644
--- a/src/cmd/compile/internal/types2/typestring.go
+++ b/src/cmd/compile/internal/types2/typestring.go
@@ -39,27 +39,6 @@ func RelativeTo(pkg *Package) Qualifier {
 	}
 }
 
-// If gcCompatibilityMode is set, printing of types is modified
-// to match the representation of some types in the gc compiler:
-//
-//	- byte and rune lose their alias name and simply stand for
-//	  uint8 and int32 respectively
-//	- embedded interfaces get flattened (the embedding info is lost,
-//	  and certain recursive interface types cannot be printed anymore)
-//
-// This makes it easier to compare packages computed with the type-
-// checker vs packages imported from gc export data.
-//
-// Caution: This flag affects all uses of WriteType, globally.
-// It is only provided for testing in conjunction with
-// gc-generated data.
-//
-// This flag is exported in the x/tools/go/types package. We don't
-// need it at the moment in the std repo and so we don't export it
-// anymore. We should eventually try to remove it altogether.
-// TODO(gri) remove this
-var gcCompatibilityMode bool
-
 // TypeString returns the string representation of typ.
 // The Qualifier controls the printing of
 // package-level objects, and may be nil.
@@ -106,16 +85,6 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				break
 			}
 		}
-
-		if gcCompatibilityMode {
-			// forget the alias names
-			switch t.kind {
-			case Byte:
-				t = Typ[Uint8]
-			case Rune:
-				t = Typ[Int32]
-			}
-		}
 		buf.WriteString(t.name)
 
 	case *Array:
@@ -157,80 +126,39 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		buf.WriteString("func")
 		writeSignature(buf, t, qf, visited)
 
-	case *Sum:
-		for i, t := range t.types {
+	case *Union:
+		// Unions only appear as (syntactic) embedded elements
+		// in interfaces and syntactically cannot be empty.
+		if t.Len() == 0 {
+			panic("empty union")
+		}
+		for i, t := range t.terms {
 			if i > 0 {
-				buf.WriteString(", ")
+				buf.WriteByte('|')
 			}
-			writeType(buf, t, qf, visited)
+			if t.tilde {
+				buf.WriteByte('~')
+			}
+			writeType(buf, t.typ, qf, visited)
 		}
 
 	case *Interface:
-		// We write the source-level methods and embedded types rather
-		// than the actual method set since resolved method signatures
-		// may have non-printable cycles if parameters have embedded
-		// interface types that (directly or indirectly) embed the
-		// current interface. For instance, consider the result type
-		// of m:
-		//
-		//     type T interface{
-		//         m() interface{ T }
-		//     }
-		//
 		buf.WriteString("interface{")
-		empty := true
-		if gcCompatibilityMode {
-			// print flattened interface
-			// (useful to compare against gc-generated interfaces)
-			for i, m := range t.allMethods {
-				if i > 0 {
-					buf.WriteString("; ")
-				}
-				buf.WriteString(m.name)
-				writeSignature(buf, m.typ.(*Signature), qf, visited)
-				empty = false
-			}
-			if !empty && t.allTypes != nil {
+		first := true
+		for _, m := range t.methods {
+			if !first {
 				buf.WriteString("; ")
 			}
-			if t.allTypes != nil {
-				buf.WriteString("type ")
-				writeType(buf, t.allTypes, qf, visited)
-			}
-		} else {
-			// print explicit interface methods and embedded types
-			for i, m := range t.methods {
-				if i > 0 {
-					buf.WriteString("; ")
-				}
-				buf.WriteString(m.name)
-				writeSignature(buf, m.typ.(*Signature), qf, visited)
-				empty = false
-			}
-			if !empty && t.types != nil {
-				buf.WriteString("; ")
-			}
-			if t.types != nil {
-				buf.WriteString("type ")
-				writeType(buf, t.types, qf, visited)
-				empty = false
-			}
-			if !empty && len(t.embeddeds) > 0 {
-				buf.WriteString("; ")
-			}
-			for i, typ := range t.embeddeds {
-				if i > 0 {
-					buf.WriteString("; ")
-				}
-				writeType(buf, typ, qf, visited)
-				empty = false
-			}
+			first = false
+			buf.WriteString(m.name)
+			writeSignature(buf, m.typ.(*Signature), qf, visited)
 		}
-		if t.allMethods == nil || len(t.methods) > len(t.allMethods) {
-			if !empty {
-				buf.WriteByte(' ')
+		for _, typ := range t.embeddeds {
+			if !first {
+				buf.WriteString("; ")
 			}
-			buf.WriteString("/* incomplete */")
+			first = false
+			writeType(buf, typ, qf, visited)
 		}
 		buf.WriteByte('}')
 
@@ -255,7 +183,7 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		case RecvOnly:
 			s = "<-chan "
 		default:
-			panic("unreachable")
+			unreachable()
 		}
 		buf.WriteString(s)
 		if parens {
@@ -267,39 +195,40 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		}
 
 	case *Named:
+		if t.instance != nil {
+			buf.WriteByte(instanceMarker)
+		}
 		writeTypeName(buf, t.obj, qf)
 		if t.targs != nil {
 			// instantiated type
 			buf.WriteByte('[')
 			writeTypeList(buf, t.targs, qf, visited)
 			buf.WriteByte(']')
-		} else if t.tparams != nil {
+		} else if t.TParams().Len() != 0 {
 			// parameterized type
-			writeTParamList(buf, t.tparams, qf, visited)
+			writeTParamList(buf, t.TParams().list(), qf, visited)
 		}
 
 	case *TypeParam:
 		s := "?"
 		if t.obj != nil {
+			// Optionally write out package for typeparams (like Named).
+			// TODO(danscales): this is required for import/export, so
+			// we maybe need a separate function that won't be changed
+			// for debugging purposes.
+			if t.obj.pkg != nil {
+				writePackage(buf, t.obj.pkg, qf)
+			}
 			s = t.obj.name
 		}
 		buf.WriteString(s + subscript(t.id))
 
-	case *instance:
-		buf.WriteByte(instanceMarker) // indicate "non-evaluated" syntactic instance
-		writeTypeName(buf, t.base.obj, qf)
-		buf.WriteByte('[')
-		writeTypeList(buf, t.targs, qf, visited)
-		buf.WriteByte(']')
-
-	case *bottom:
-		buf.WriteString("⊥")
-
 	case *top:
 		buf.WriteString("⊤")
 
 	default:
 		// For externally defined implementations of Type.
+		// Note: In this case cycles won't be caught.
 		buf.WriteString(t.String())
 	}
 }
@@ -317,23 +246,27 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited
 	buf.WriteString("[")
 	var prev Type
 	for i, p := range list {
-		// TODO(gri) support 'any' sugar here.
-		var b Type = &emptyInterface
-		if t, _ := p.typ.(*TypeParam); t != nil && t.bound != nil {
-			b = t.bound
+		// Determine the type parameter and its constraint.
+		// list is expected to hold type parameter names,
+		// but don't crash if that's not the case.
+		tpar, _ := p.typ.(*TypeParam)
+		var bound Type
+		if tpar != nil {
+			bound = tpar.bound // should not be nil but we want to see it if it is
 		}
+
 		if i > 0 {
-			if b != prev {
-				// type bound changed - write previous one before advancing
+			if bound != prev {
+				// bound changed - write previous one before advancing
 				buf.WriteByte(' ')
 				writeType(buf, prev, qf, visited)
 			}
 			buf.WriteString(", ")
 		}
-		prev = b
+		prev = bound
 
-		if t, _ := p.typ.(*TypeParam); t != nil {
-			writeType(buf, t, qf, visited)
+		if tpar != nil {
+			writeType(buf, tpar, qf, visited)
 		} else {
 			buf.WriteString(p.name)
 		}
@@ -346,17 +279,38 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited
 }
 
 func writeTypeName(buf *bytes.Buffer, obj *TypeName, qf Qualifier) {
-	s := ""
-	if obj != nil {
-		if obj.pkg != nil {
-			writePackage(buf, obj.pkg, qf)
-		}
-		// TODO(gri): function-local named types should be displayed
-		// differently from named types at package level to avoid
-		// ambiguity.
-		s = obj.name
+	if obj == nil {
+		buf.WriteString("")
+		return
+	}
+	if obj.pkg != nil {
+		writePackage(buf, obj.pkg, qf)
+	}
+	buf.WriteString(obj.name)
+
+	if instanceHashing != 0 {
+		// For local defined types, use the (original!) TypeName's scope
+		// numbers to disambiguate.
+		typ := obj.typ.(*Named)
+		// TODO(gri) Figure out why typ.orig != typ.orig.orig sometimes
+		//           and whether the loop can iterate more than twice.
+		//           (It seems somehow connected to instance types.)
+		for typ.orig != typ {
+			typ = typ.orig
+		}
+		writeScopeNumbers(buf, typ.obj.parent)
+	}
+}
+
+// writeScopeNumbers writes the number sequence for this scope to buf
+// in the form ".i.j.k" where i, j, k, etc. stand for scope numbers.
+// If a scope is nil or has no parent (such as a package scope), nothing
+// is written.
+func writeScopeNumbers(buf *bytes.Buffer, s *Scope) {
+	if s != nil && s.number > 0 {
+		writeScopeNumbers(buf, s.parent)
+		fmt.Fprintf(buf, ".%d", s.number)
 	}
-	buf.WriteString(s)
 }
 
 func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visited []Type) {
@@ -379,7 +333,7 @@ func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visi
 					// special case:
 					// append(s, "foo"...) leads to signature func([]byte, string...)
 					if t := asBasic(typ); t == nil || t.kind != String {
-						panic("internal error: string type expected")
+						panic("expected string type")
 					}
 					writeType(buf, typ, qf, visited)
 					buf.WriteString("...")
@@ -401,8 +355,8 @@ func WriteSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier) {
 }
 
 func writeSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier, visited []Type) {
-	if sig.tparams != nil {
-		writeTParamList(buf, sig.tparams, qf, visited)
+	if sig.TParams().Len() != 0 {
+		writeTParamList(buf, sig.TParams().list(), qf, visited)
 	}
 
 	writeTuple(buf, sig.params, sig.variadic, qf, visited)
diff --git a/src/cmd/compile/internal/types2/typestring_test.go b/src/cmd/compile/internal/types2/typestring_test.go
index d98e9a5ade6..0ed29349610 100644
--- a/src/cmd/compile/internal/types2/typestring_test.go
+++ b/src/cmd/compile/internal/types2/typestring_test.go
@@ -91,7 +91,8 @@ var independentTestTypes = []testEntry{
 	dup("interface{}"),
 	dup("interface{m()}"),
 	dup(`interface{String() string; m(int) float32}`),
-	dup(`interface{type int, float32, complex128}`),
+	dup("interface{int|float32|complex128}"),
+	dup("interface{int|~float32|~complex128}"),
 
 	// maps
 	dup("map[string]int"),
@@ -135,60 +136,6 @@ func TestTypeString(t *testing.T) {
 	}
 }
 
-var nopos syntax.Pos
-
-func TestIncompleteInterfaces(t *testing.T) {
-	sig := NewSignature(nil, nil, nil, false)
-	m := NewFunc(nopos, nil, "m", sig)
-	for _, test := range []struct {
-		typ  *Interface
-		want string
-	}{
-		{new(Interface), "interface{/* incomplete */}"},
-		{new(Interface).Complete(), "interface{}"},
-
-		{NewInterface(nil, nil), "interface{}"},
-		{NewInterface(nil, nil).Complete(), "interface{}"},
-		{NewInterface([]*Func{}, nil), "interface{}"},
-		{NewInterface([]*Func{}, nil).Complete(), "interface{}"},
-		{NewInterface(nil, []*Named{}), "interface{}"},
-		{NewInterface(nil, []*Named{}).Complete(), "interface{}"},
-		{NewInterface([]*Func{m}, nil), "interface{m() /* incomplete */}"},
-		{NewInterface([]*Func{m}, nil).Complete(), "interface{m()}"},
-		{NewInterface(nil, []*Named{newDefined(new(Interface).Complete())}), "interface{T /* incomplete */}"},
-		{NewInterface(nil, []*Named{newDefined(new(Interface).Complete())}).Complete(), "interface{T}"},
-		{NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil))}), "interface{T /* incomplete */}"},
-		{NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil).Complete())}), "interface{T /* incomplete */}"},
-		{NewInterface(nil, []*Named{newDefined(NewInterface([]*Func{m}, nil).Complete())}).Complete(), "interface{T}"},
-
-		{NewInterfaceType(nil, nil), "interface{}"},
-		{NewInterfaceType(nil, nil).Complete(), "interface{}"},
-		{NewInterfaceType([]*Func{}, nil), "interface{}"},
-		{NewInterfaceType([]*Func{}, nil).Complete(), "interface{}"},
-		{NewInterfaceType(nil, []Type{}), "interface{}"},
-		{NewInterfaceType(nil, []Type{}).Complete(), "interface{}"},
-		{NewInterfaceType([]*Func{m}, nil), "interface{m() /* incomplete */}"},
-		{NewInterfaceType([]*Func{m}, nil).Complete(), "interface{m()}"},
-		{NewInterfaceType(nil, []Type{new(Interface).Complete()}), "interface{interface{} /* incomplete */}"},
-		{NewInterfaceType(nil, []Type{new(Interface).Complete()}).Complete(), "interface{interface{}}"},
-		{NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil)}), "interface{interface{m() /* incomplete */} /* incomplete */}"},
-		{NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil).Complete()}), "interface{interface{m()} /* incomplete */}"},
-		{NewInterfaceType(nil, []Type{NewInterfaceType([]*Func{m}, nil).Complete()}).Complete(), "interface{interface{m()}}"},
-	} {
-		got := test.typ.String()
-		if got != test.want {
-			t.Errorf("got: %s, want: %s", got, test.want)
-		}
-	}
-}
-
-// newDefined creates a new defined type named T with the given underlying type.
-// Helper function for use with TestIncompleteInterfaces only.
-func newDefined(underlying Type) *Named {
-	tname := NewTypeName(nopos, nil, "T", nil)
-	return NewNamed(tname, underlying, nil)
-}
-
 func TestQualifiedTypeString(t *testing.T) {
 	p, _ := pkgFor("p.go", "package p; type T int", nil)
 	q, _ := pkgFor("q.go", "package q", nil)
diff --git a/src/cmd/compile/internal/types2/typeterm.go b/src/cmd/compile/internal/types2/typeterm.go
new file mode 100644
index 00000000000..1d7223f13c4
--- /dev/null
+++ b/src/cmd/compile/internal/types2/typeterm.go
@@ -0,0 +1,166 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+// A term describes elementary type sets:
+//
+//   ∅:  (*term)(nil)     == ∅                      // set of no types (empty set)
+//   𝓤:  &term{}          == 𝓤                      // set of all types (𝓤niverse)
+//   T:  &term{false, T}  == {T}                    // set of type T
+//  ~t:  &term{true, t}   == {t' | under(t') == t}  // set of types with underlying type t
+//
+type term struct {
+	tilde bool // valid if typ != nil
+	typ   Type
+}
+
+func (x *term) String() string {
+	switch {
+	case x == nil:
+		return "∅"
+	case x.typ == nil:
+		return "𝓤"
+	case x.tilde:
+		return "~" + x.typ.String()
+	default:
+		return x.typ.String()
+	}
+}
+
+// equal reports whether x and y represent the same type set.
+func (x *term) equal(y *term) bool {
+	// easy cases
+	switch {
+	case x == nil || y == nil:
+		return x == y
+	case x.typ == nil || y.typ == nil:
+		return x.typ == y.typ
+	}
+	// ∅ ⊂ x, y ⊂ 𝓤
+
+	return x.tilde == y.tilde && Identical(x.typ, y.typ)
+}
+
+// union returns the union x ∪ y: zero, one, or two non-nil terms.
+func (x *term) union(y *term) (_, _ *term) {
+	// easy cases
+	switch {
+	case x == nil && y == nil:
+		return nil, nil // ∅ ∪ ∅ == ∅
+	case x == nil:
+		return y, nil // ∅ ∪ y == y
+	case y == nil:
+		return x, nil // x ∪ ∅ == x
+	case x.typ == nil:
+		return x, nil // 𝓤 ∪ y == 𝓤
+	case y.typ == nil:
+		return y, nil // x ∪ 𝓤 == 𝓤
+	}
+	// ∅ ⊂ x, y ⊂ 𝓤
+
+	if x.disjoint(y) {
+		return x, y // x ∪ y == (x, y) if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ∪ ~t == ~t
+	// ~t ∪  T == ~t
+	//  T ∪ ~t == ~t
+	//  T ∪  T ==  T
+	if x.tilde || !y.tilde {
+		return x, nil
+	}
+	return y, nil
+}
+
+// intersect returns the intersection x ∩ y.
+func (x *term) intersect(y *term) *term {
+	// easy cases
+	switch {
+	case x == nil || y == nil:
+		return nil // ∅ ∩ y == ∅ and ∩ ∅ == ∅
+	case x.typ == nil:
+		return y // 𝓤 ∩ y == y
+	case y.typ == nil:
+		return x // x ∩ 𝓤 == x
+	}
+	// ∅ ⊂ x, y ⊂ 𝓤
+
+	if x.disjoint(y) {
+		return nil // x ∩ y == ∅ if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ∩ ~t == ~t
+	// ~t ∩  T ==  T
+	//  T ∩ ~t ==  T
+	//  T ∩  T ==  T
+	if !x.tilde || y.tilde {
+		return x
+	}
+	return y
+}
+
+// includes reports whether t ∈ x.
+func (x *term) includes(t Type) bool {
+	// easy cases
+	switch {
+	case x == nil:
+		return false // t ∈ ∅ == false
+	case x.typ == nil:
+		return true // t ∈ 𝓤 == true
+	}
+	// ∅ ⊂ x ⊂ 𝓤
+
+	u := t
+	if x.tilde {
+		u = under(u)
+	}
+	return Identical(x.typ, u)
+}
+
+// subsetOf reports whether x ⊆ y.
+func (x *term) subsetOf(y *term) bool {
+	// easy cases
+	switch {
+	case x == nil:
+		return true // ∅ ⊆ y == true
+	case y == nil:
+		return false // x ⊆ ∅ == false since x != ∅
+	case y.typ == nil:
+		return true // x ⊆ 𝓤 == true
+	case x.typ == nil:
+		return false // 𝓤 ⊆ y == false since y != 𝓤
+	}
+	// ∅ ⊂ x, y ⊂ 𝓤
+
+	if x.disjoint(y) {
+		return false // x ⊆ y == false if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ⊆ ~t == true
+	// ~t ⊆ T == false
+	//  T ⊆ ~t == true
+	//  T ⊆  T == true
+	return !x.tilde || y.tilde
+}
+
+// disjoint reports whether x ∩ y == ∅.
+// x.typ and y.typ must not be nil.
+func (x *term) disjoint(y *term) bool {
+	if debug && (x.typ == nil || y.typ == nil) {
+		panic("invalid argument(s)")
+	}
+	ux := x.typ
+	if y.tilde {
+		ux = under(ux)
+	}
+	uy := y.typ
+	if x.tilde {
+		uy = under(uy)
+	}
+	return !Identical(ux, uy)
+}
diff --git a/src/cmd/compile/internal/types2/typeterm_test.go b/src/cmd/compile/internal/types2/typeterm_test.go
new file mode 100644
index 00000000000..5a5c1fa4477
--- /dev/null
+++ b/src/cmd/compile/internal/types2/typeterm_test.go
@@ -0,0 +1,239 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import (
+	"strings"
+	"testing"
+)
+
+var myInt = func() Type {
+	tname := NewTypeName(nopos, nil, "myInt", nil)
+	return NewNamed(tname, Typ[Int], nil)
+}()
+
+var testTerms = map[string]*term{
+	"∅":       nil,
+	"𝓤":       {},
+	"int":     {false, Typ[Int]},
+	"~int":    {true, Typ[Int]},
+	"string":  {false, Typ[String]},
+	"~string": {true, Typ[String]},
+	"myInt":   {false, myInt},
+}
+
+func TestTermString(t *testing.T) {
+	for want, x := range testTerms {
+		if got := x.String(); got != want {
+			t.Errorf("%v.String() == %v; want %v", x, got, want)
+		}
+	}
+}
+
+func split(s string, n int) []string {
+	r := strings.Split(s, " ")
+	if len(r) != n {
+		panic("invalid test case: " + s)
+	}
+	return r
+}
+
+func testTerm(name string) *term {
+	r, ok := testTerms[name]
+	if !ok {
+		panic("invalid test argument: " + name)
+	}
+	return r
+}
+
+func TestTermEqual(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ T",
+		"𝓤 𝓤 T",
+		"int int T",
+		"~int ~int T",
+		"myInt myInt T",
+		"∅ 𝓤 F",
+		"∅ int F",
+		"∅ ~int F",
+		"𝓤 int F",
+		"𝓤 ~int F",
+		"𝓤 myInt F",
+		"int ~int F",
+		"int myInt F",
+		"~int myInt F",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.equal(y); got != want {
+			t.Errorf("%v.equal(%v) = %v; want %v", x, y, got, want)
+		}
+		// equal is symmetric
+		x, y = y, x
+		if got := x.equal(y); got != want {
+			t.Errorf("%v.equal(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermUnion(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ ∅ ∅",
+		"∅ 𝓤 𝓤 ∅",
+		"∅ int int ∅",
+		"∅ ~int ~int ∅",
+		"∅ myInt myInt ∅",
+		"𝓤 𝓤 𝓤 ∅",
+		"𝓤 int 𝓤 ∅",
+		"𝓤 ~int 𝓤 ∅",
+		"𝓤 myInt 𝓤 ∅",
+		"int int int ∅",
+		"int ~int ~int ∅",
+		"int string int string",
+		"int ~string int ~string",
+		"int myInt int myInt",
+		"~int ~string ~int ~string",
+		"~int myInt ~int ∅",
+
+		// union is symmetric, but the result order isn't - repeat symmetric cases explictly
+		"𝓤 ∅ 𝓤 ∅",
+		"int ∅ int ∅",
+		"~int ∅ ~int ∅",
+		"myInt ∅ myInt ∅",
+		"int 𝓤 𝓤 ∅",
+		"~int 𝓤 𝓤 ∅",
+		"myInt 𝓤 𝓤 ∅",
+		"~int int ~int ∅",
+		"string int string int",
+		"~string int ~string int",
+		"myInt int myInt int",
+		"~string ~int ~string ~int",
+		"myInt ~int ~int ∅",
+	} {
+		args := split(test, 4)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want1 := testTerm(args[2])
+		want2 := testTerm(args[3])
+		if got1, got2 := x.union(y); !got1.equal(want1) || !got2.equal(want2) {
+			t.Errorf("%v.union(%v) = %v, %v; want %v, %v", x, y, got1, got2, want1, want2)
+		}
+	}
+}
+
+func TestTermIntersection(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ ∅",
+		"∅ 𝓤 ∅",
+		"∅ int ∅",
+		"∅ ~int ∅",
+		"∅ myInt ∅",
+		"𝓤 𝓤 𝓤",
+		"𝓤 int int",
+		"𝓤 ~int ~int",
+		"𝓤 myInt myInt",
+		"int int int",
+		"int ~int int",
+		"int string ∅",
+		"int ~string ∅",
+		"int string ∅",
+		"~int ~string ∅",
+		"~int myInt myInt",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := testTerm(args[2])
+		if got := x.intersect(y); !got.equal(want) {
+			t.Errorf("%v.intersect(%v) = %v; want %v", x, y, got, want)
+		}
+		// intersect is symmetric
+		x, y = y, x
+		if got := x.intersect(y); !got.equal(want) {
+			t.Errorf("%v.intersect(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermIncludes(t *testing.T) {
+	for _, test := range []string{
+		"∅ int F",
+		"𝓤 int T",
+		"int int T",
+		"~int int T",
+		"~int myInt T",
+		"string int F",
+		"~string int F",
+		"myInt int F",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1]).typ
+		want := args[2] == "T"
+		if got := x.includes(y); got != want {
+			t.Errorf("%v.includes(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermSubsetOf(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ T",
+		"𝓤 𝓤 T",
+		"int int T",
+		"~int ~int T",
+		"myInt myInt T",
+		"∅ 𝓤 T",
+		"∅ int T",
+		"∅ ~int T",
+		"∅ myInt T",
+		"𝓤 int F",
+		"𝓤 ~int F",
+		"𝓤 myInt F",
+		"int ~int T",
+		"int myInt F",
+		"~int myInt F",
+		"myInt int F",
+		"myInt ~int T",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.subsetOf(y); got != want {
+			t.Errorf("%v.subsetOf(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermDisjoint(t *testing.T) {
+	for _, test := range []string{
+		"int int F",
+		"~int ~int F",
+		"int ~int F",
+		"int string T",
+		"int ~string T",
+		"int myInt T",
+		"~int ~string T",
+		"~int myInt F",
+		"string myInt T",
+		"~string myInt T",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.disjoint(y); got != want {
+			t.Errorf("%v.disjoint(%v) = %v; want %v", x, y, got, want)
+		}
+		// disjoint is symmetric
+		x, y = y, x
+		if got := x.disjoint(y); got != want {
+			t.Errorf("%v.disjoint(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go
index e64d804c30b..a53319c1539 100644
--- a/src/cmd/compile/internal/types2/typexpr.go
+++ b/src/cmd/compile/internal/types2/typexpr.go
@@ -10,14 +10,9 @@ import (
 	"cmd/compile/internal/syntax"
 	"fmt"
 	"go/constant"
-	"sort"
-	"strconv"
 	"strings"
 )
 
-// Disabled by default, but enabled when running tests (via types_test.go).
-var acceptMethodTypeParams bool
-
 // ident type-checks identifier e and initializes x with the value or type of e.
 // If an error occurred, x.mode is set to invalid.
 // For the meaning of def, see Checker.definedType, below.
@@ -30,7 +25,8 @@ func (check *Checker) ident(x *operand, e *syntax.Name, def *Named, wantType boo
 	// Note that we cannot use check.lookup here because the returned scope
 	// may be different from obj.Parent(). See also Scope.LookupParent doc.
 	scope, obj := check.scope.LookupParent(e.Value, check.pos)
-	if obj == nil {
+	switch obj {
+	case nil:
 		if e.Value == "_" {
 			check.error(e, "cannot use _ as value or type")
 		} else {
@@ -41,6 +37,16 @@ func (check *Checker) ident(x *operand, e *syntax.Name, def *Named, wantType boo
 			}
 		}
 		return
+	case universeAny, universeComparable:
+		if !check.allowVersion(check.pkg, 1, 18) {
+			check.errorf(e, "undeclared name: %s (requires version go1.18 or later)", e.Value)
+			return
+		}
+		// If we allow "any" for general use, this if-statement can be removed (issue #33232).
+		if obj == universeAny {
+			check.error(e, "cannot use any outside constraint position")
+			return
+		}
 	}
 	check.recordUse(e, obj)
 
@@ -63,7 +69,7 @@ func (check *Checker) ident(x *operand, e *syntax.Name, def *Named, wantType boo
 	// If so, mark the respective package as used.
 	// (This code is only needed for dot-imports. Without them,
 	// we only have to mark variables, see *Var case below).
-	if pkgName := check.dotImportMap[dotImportKey{scope, obj}]; pkgName != nil {
+	if pkgName := check.dotImportMap[dotImportKey{scope, obj.Name()}]; pkgName != nil {
 		pkgName.used = true
 	}
 
@@ -141,18 +147,18 @@ func (check *Checker) varType(e syntax.Expr) Type {
 // ordinaryType reports an error if typ is an interface type containing
 // type lists or is (or embeds) the predeclared type comparable.
 func (check *Checker) ordinaryType(pos syntax.Pos, typ Type) {
-	// We don't want to call under() (via Interface) or complete interfaces while we
+	// We don't want to call under() (via asInterface) or complete interfaces while we
 	// are in the middle of type-checking parameter declarations that might belong to
 	// interface methods. Delay this check to the end of type-checking.
 	check.later(func() {
 		if t := asInterface(typ); t != nil {
-			check.completeInterface(pos, t) // TODO(gri) is this the correct position?
-			if t.allTypes != nil {
-				check.softErrorf(pos, "interface contains type constraints (%s)", t.allTypes)
-				return
-			}
-			if t.IsComparable() {
-				check.softErrorf(pos, "interface is (or embeds) comparable")
+			tset := computeInterfaceTypeSet(check, pos, t) // TODO(gri) is this the correct position?
+			if !tset.IsMethodSet() {
+				if tset.comparable {
+					check.softErrorf(pos, "interface is (or embeds) comparable")
+				} else {
+					check.softErrorf(pos, "interface contains type constraints")
+				}
 			}
 		}
 	})
@@ -198,238 +204,6 @@ func (check *Checker) genericType(e syntax.Expr, reportErr bool) Type {
 	return typ
 }
 
-// isubst returns an x with identifiers substituted per the substitution map smap.
-// isubst only handles the case of (valid) method receiver type expressions correctly.
-func isubst(x syntax.Expr, smap map[*syntax.Name]*syntax.Name) syntax.Expr {
-	switch n := x.(type) {
-	case *syntax.Name:
-		if alt := smap[n]; alt != nil {
-			return alt
-		}
-	// case *syntax.StarExpr:
-	// 	X := isubst(n.X, smap)
-	// 	if X != n.X {
-	// 		new := *n
-	// 		new.X = X
-	// 		return &new
-	// 	}
-	case *syntax.Operation:
-		if n.Op == syntax.Mul && n.Y == nil {
-			X := isubst(n.X, smap)
-			if X != n.X {
-				new := *n
-				new.X = X
-				return &new
-			}
-		}
-	case *syntax.IndexExpr:
-		Index := isubst(n.Index, smap)
-		if Index != n.Index {
-			new := *n
-			new.Index = Index
-			return &new
-		}
-	case *syntax.ListExpr:
-		var elems []syntax.Expr
-		for i, elem := range n.ElemList {
-			new := isubst(elem, smap)
-			if new != elem {
-				if elems == nil {
-					elems = make([]syntax.Expr, len(n.ElemList))
-					copy(elems, n.ElemList)
-				}
-				elems[i] = new
-			}
-		}
-		if elems != nil {
-			new := *n
-			new.ElemList = elems
-			return &new
-		}
-	case *syntax.ParenExpr:
-		return isubst(n.X, smap) // no need to keep parentheses
-	default:
-		// Other receiver type expressions are invalid.
-		// It's fine to ignore those here as they will
-		// be checked elsewhere.
-	}
-	return x
-}
-
-// funcType type-checks a function or method type.
-func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []*syntax.Field, ftyp *syntax.FuncType) {
-	check.openScope(ftyp, "function")
-	check.scope.isFunc = true
-	check.recordScope(ftyp, check.scope)
-	sig.scope = check.scope
-	defer check.closeScope()
-
-	var recvTyp syntax.Expr // rewritten receiver type; valid if != nil
-	if recvPar != nil {
-		// collect generic receiver type parameters, if any
-		// - a receiver type parameter is like any other type parameter, except that it is declared implicitly
-		// - the receiver specification acts as local declaration for its type parameters, which may be blank
-		_, rname, rparams := check.unpackRecv(recvPar.Type, true)
-		if len(rparams) > 0 {
-			// Blank identifiers don't get declared and regular type-checking of the instantiated
-			// parameterized receiver type expression fails in Checker.collectParams of receiver.
-			// Identify blank type parameters and substitute each with a unique new identifier named
-			// "n_" (where n is the parameter index) and which cannot conflict with any user-defined
-			// name.
-			var smap map[*syntax.Name]*syntax.Name // substitution map from "_" to "!n" identifiers
-			for i, p := range rparams {
-				if p.Value == "_" {
-					new := *p
-					new.Value = fmt.Sprintf("%d_", i)
-					rparams[i] = &new // use n_ identifier instead of _ so it can be looked up
-					if smap == nil {
-						smap = make(map[*syntax.Name]*syntax.Name)
-					}
-					smap[p] = &new
-				}
-			}
-			if smap != nil {
-				// blank identifiers were found => use rewritten receiver type
-				recvTyp = isubst(recvPar.Type, smap)
-			}
-			// TODO(gri) rework declareTypeParams
-			sig.rparams = nil
-			for _, rparam := range rparams {
-				sig.rparams = check.declareTypeParam(sig.rparams, rparam)
-			}
-			// determine receiver type to get its type parameters
-			// and the respective type parameter bounds
-			var recvTParams []*TypeName
-			if rname != nil {
-				// recv should be a Named type (otherwise an error is reported elsewhere)
-				// Also: Don't report an error via genericType since it will be reported
-				//       again when we type-check the signature.
-				// TODO(gri) maybe the receiver should be marked as invalid instead?
-				if recv := asNamed(check.genericType(rname, false)); recv != nil {
-					recvTParams = recv.tparams
-				}
-			}
-			// provide type parameter bounds
-			// - only do this if we have the right number (otherwise an error is reported elsewhere)
-			if len(sig.rparams) == len(recvTParams) {
-				// We have a list of *TypeNames but we need a list of Types.
-				list := make([]Type, len(sig.rparams))
-				for i, t := range sig.rparams {
-					list[i] = t.typ
-				}
-				smap := makeSubstMap(recvTParams, list)
-				for i, tname := range sig.rparams {
-					bound := recvTParams[i].typ.(*TypeParam).bound
-					// bound is (possibly) parameterized in the context of the
-					// receiver type declaration. Substitute parameters for the
-					// current context.
-					// TODO(gri) should we assume now that bounds always exist?
-					//           (no bound == empty interface)
-					if bound != nil {
-						bound = check.subst(tname.pos, bound, smap)
-						tname.typ.(*TypeParam).bound = bound
-					}
-				}
-			}
-		}
-	}
-
-	if tparams != nil {
-		sig.tparams = check.collectTypeParams(tparams)
-		// Always type-check method type parameters but complain if they are not enabled.
-		// (A separate check is needed when type-checking interface method signatures because
-		// they don't have a receiver specification.)
-		if recvPar != nil && !acceptMethodTypeParams {
-			check.error(ftyp, "methods cannot have type parameters")
-		}
-	}
-
-	// Value (non-type) parameters' scope starts in the function body. Use a temporary scope for their
-	// declarations and then squash that scope into the parent scope (and report any redeclarations at
-	// that time).
-	scope := NewScope(check.scope, nopos, nopos, "function body (temp. scope)")
-	var recvList []*Var // TODO(gri) remove the need for making a list here
-	if recvPar != nil {
-		recvList, _ = check.collectParams(scope, []*syntax.Field{recvPar}, recvTyp, false) // use rewritten receiver type, if any
-	}
-	params, variadic := check.collectParams(scope, ftyp.ParamList, nil, true)
-	results, _ := check.collectParams(scope, ftyp.ResultList, nil, false)
-	scope.Squash(func(obj, alt Object) {
-		var err error_
-		err.errorf(obj, "%s redeclared in this block", obj.Name())
-		err.recordAltDecl(alt)
-		check.report(&err)
-	})
-
-	if recvPar != nil {
-		// recv parameter list present (may be empty)
-		// spec: "The receiver is specified via an extra parameter section preceding the
-		// method name. That parameter section must declare a single parameter, the receiver."
-		var recv *Var
-		switch len(recvList) {
-		case 0:
-			// error reported by resolver
-			recv = NewParam(nopos, nil, "", Typ[Invalid]) // ignore recv below
-		default:
-			// more than one receiver
-			check.error(recvList[len(recvList)-1].Pos(), "method must have exactly one receiver")
-			fallthrough // continue with first receiver
-		case 1:
-			recv = recvList[0]
-		}
-
-		// TODO(gri) We should delay rtyp expansion to when we actually need the
-		//           receiver; thus all checks here should be delayed to later.
-		rtyp, _ := deref(recv.typ)
-		rtyp = expand(rtyp)
-
-		// spec: "The receiver type must be of the form T or *T where T is a type name."
-		// (ignore invalid types - error was reported before)
-		if t := rtyp; t != Typ[Invalid] {
-			var err string
-			if T := asNamed(t); T != nil {
-				// spec: "The type denoted by T is called the receiver base type; it must not
-				// be a pointer or interface type and it must be declared in the same package
-				// as the method."
-				if T.obj.pkg != check.pkg {
-					err = "type not defined in this package"
-					if check.conf.CompilerErrorMessages {
-						check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
-						err = ""
-					}
-				} else {
-					switch u := optype(T).(type) {
-					case *Basic:
-						// unsafe.Pointer is treated like a regular pointer
-						if u.kind == UnsafePointer {
-							err = "unsafe.Pointer"
-						}
-					case *Pointer, *Interface:
-						err = "pointer or interface type"
-					}
-				}
-			} else if T := asBasic(t); T != nil {
-				err = "basic or unnamed type"
-				if check.conf.CompilerErrorMessages {
-					check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
-					err = ""
-				}
-			} else {
-				check.errorf(recv.pos, "invalid receiver type %s", recv.typ)
-			}
-			if err != "" {
-				check.errorf(recv.pos, "invalid receiver type %s (%s)", recv.typ, err)
-				// ok to continue
-			}
-		}
-		sig.recv = recv
-	}
-
-	sig.params = NewTuple(params...)
-	sig.results = NewTuple(results...)
-	sig.variadic = variadic
-}
-
 // goTypeName returns the Go type name for typ and
 // removes any occurrences of "types2." from that name.
 func goTypeName(typ Type) string {
@@ -451,7 +225,7 @@ func (check *Checker) typInternal(e0 syntax.Expr, def *Named) (T Type) {
 				// Test case: type T[P any] *T[P]
 				// TODO(gri) investigate if that's a bug or to be expected
 				// (see also analogous comment in Checker.instantiate).
-				under = T.Underlying()
+				under = safeUnderlying(T)
 			}
 			if T == under {
 				check.trace(e0.Pos(), "=> %s // %s", T, goTypeName(T))
@@ -647,44 +421,36 @@ func (check *Checker) typOrNil(e syntax.Expr) Type {
 	return Typ[Invalid]
 }
 
-func (check *Checker) instantiatedType(x syntax.Expr, targs []syntax.Expr, def *Named) Type {
-	b := check.genericType(x, true) // TODO(gri) what about cycles?
-	if b == Typ[Invalid] {
-		return b // error already reported
+func (check *Checker) instantiatedType(x syntax.Expr, targsx []syntax.Expr, def *Named) Type {
+	gtyp := check.genericType(x, true)
+	if gtyp == Typ[Invalid] {
+		return gtyp // error already reported
 	}
-	base := asNamed(b)
+	base, _ := gtyp.(*Named)
 	if base == nil {
-		unreachable() // should have been caught by genericType
+		panic(fmt.Sprintf("%v: cannot instantiate %v", x.Pos(), gtyp))
 	}
 
-	// create a new type instance rather than instantiate the type
-	// TODO(gri) should do argument number check here rather than
-	//           when instantiating the type?
-	typ := new(instance)
-	def.setUnderlying(typ)
-
-	typ.check = check
-	typ.pos = x.Pos()
-	typ.base = base
-
-	// evaluate arguments (always)
-	typ.targs = check.typeList(targs)
-	if typ.targs == nil {
+	// evaluate arguments
+	targs := check.typeList(targsx)
+	if targs == nil {
 		def.setUnderlying(Typ[Invalid]) // avoid later errors due to lazy instantiation
 		return Typ[Invalid]
 	}
 
-	// determine argument positions (for error reporting)
-	typ.poslist = make([]syntax.Pos, len(targs))
-	for i, arg := range targs {
-		typ.poslist[i] = syntax.StartPos(arg)
+	// determine argument positions
+	posList := make([]syntax.Pos, len(targs))
+	for i, arg := range targsx {
+		posList[i] = syntax.StartPos(arg)
 	}
 
+	typ := check.instantiateLazy(x.Pos(), base, targs, posList, true)
+	def.setUnderlying(typ)
+
 	// make sure we check instantiation works at least once
 	// and that the resulting type is valid
 	check.later(func() {
-		t := typ.expand()
-		check.validType(t, nil)
+		check.validType(typ, nil)
 	})
 
 	return typ
@@ -732,537 +498,3 @@ func (check *Checker) typeList(list []syntax.Expr) []Type {
 	}
 	return res
 }
-
-// collectParams declares the parameters of list in scope and returns the corresponding
-// variable list. If type0 != nil, it is used instead of the first type in list.
-func (check *Checker) collectParams(scope *Scope, list []*syntax.Field, type0 syntax.Expr, variadicOk bool) (params []*Var, variadic bool) {
-	if list == nil {
-		return
-	}
-
-	var named, anonymous bool
-
-	var typ Type
-	var prev syntax.Expr
-	for i, field := range list {
-		ftype := field.Type
-		// type-check type of grouped fields only once
-		if ftype != prev {
-			prev = ftype
-			if i == 0 && type0 != nil {
-				ftype = type0
-			}
-			if t, _ := ftype.(*syntax.DotsType); t != nil {
-				ftype = t.Elem
-				if variadicOk && i == len(list)-1 {
-					variadic = true
-				} else {
-					check.softErrorf(t, "can only use ... with final parameter in list")
-					// ignore ... and continue
-				}
-			}
-			typ = check.varType(ftype)
-		}
-		// The parser ensures that f.Tag is nil and we don't
-		// care if a constructed AST contains a non-nil tag.
-		if field.Name != nil {
-			// named parameter
-			name := field.Name.Value
-			if name == "" {
-				check.error(field.Name, invalidAST+"anonymous parameter")
-				// ok to continue
-			}
-			par := NewParam(field.Name.Pos(), check.pkg, name, typ)
-			check.declare(scope, field.Name, par, scope.pos)
-			params = append(params, par)
-			named = true
-		} else {
-			// anonymous parameter
-			par := NewParam(ftype.Pos(), check.pkg, "", typ)
-			check.recordImplicit(field, par)
-			params = append(params, par)
-			anonymous = true
-		}
-	}
-
-	if named && anonymous {
-		check.error(list[0], invalidAST+"list contains both named and anonymous parameters")
-		// ok to continue
-	}
-
-	// For a variadic function, change the last parameter's type from T to []T.
-	// Since we type-checked T rather than ...T, we also need to retro-actively
-	// record the type for ...T.
-	if variadic {
-		last := params[len(params)-1]
-		last.typ = &Slice{elem: last.typ}
-		check.recordTypeAndValue(list[len(list)-1].Type, typexpr, last.typ, nil)
-	}
-
-	return
-}
-
-func (check *Checker) declareInSet(oset *objset, pos syntax.Pos, obj Object) bool {
-	if alt := oset.insert(obj); alt != nil {
-		var err error_
-		err.errorf(pos, "%s redeclared", obj.Name())
-		err.recordAltDecl(alt)
-		check.report(&err)
-		return false
-	}
-	return true
-}
-
-func (check *Checker) interfaceType(ityp *Interface, iface *syntax.InterfaceType, def *Named) {
-	var tname *syntax.Name // most recent "type" name
-	var types []syntax.Expr
-	for _, f := range iface.MethodList {
-		if f.Name != nil {
-			// We have a method with name f.Name, or a type
-			// of a type list (f.Name.Value == "type").
-			name := f.Name.Value
-			if name == "_" {
-				if check.conf.CompilerErrorMessages {
-					check.error(f.Name, "methods must have a unique non-blank name")
-				} else {
-					check.error(f.Name, "invalid method name _")
-				}
-				continue // ignore
-			}
-
-			if name == "type" {
-				// Always collect all type list entries, even from
-				// different type lists, under the assumption that
-				// the author intended to include all types.
-				types = append(types, f.Type)
-				if tname != nil && tname != f.Name {
-					check.error(f.Name, "cannot have multiple type lists in an interface")
-				}
-				tname = f.Name
-				continue
-			}
-
-			typ := check.typ(f.Type)
-			sig, _ := typ.(*Signature)
-			if sig == nil {
-				if typ != Typ[Invalid] {
-					check.errorf(f.Type, invalidAST+"%s is not a method signature", typ)
-				}
-				continue // ignore
-			}
-
-			// Always type-check method type parameters but complain if they are not enabled.
-			// (This extra check is needed here because interface method signatures don't have
-			// a receiver specification.)
-			if sig.tparams != nil && !acceptMethodTypeParams {
-				check.error(f.Type, "methods cannot have type parameters")
-			}
-
-			// use named receiver type if available (for better error messages)
-			var recvTyp Type = ityp
-			if def != nil {
-				recvTyp = def
-			}
-			sig.recv = NewVar(f.Name.Pos(), check.pkg, "", recvTyp)
-
-			m := NewFunc(f.Name.Pos(), check.pkg, name, sig)
-			check.recordDef(f.Name, m)
-			ityp.methods = append(ityp.methods, m)
-		} else {
-			// We have an embedded type. completeInterface will
-			// eventually verify that we have an interface.
-			ityp.embeddeds = append(ityp.embeddeds, check.typ(f.Type))
-			check.posMap[ityp] = append(check.posMap[ityp], f.Type.Pos())
-		}
-	}
-
-	// type constraints
-	ityp.types = NewSum(check.collectTypeConstraints(iface.Pos(), types))
-
-	if len(ityp.methods) == 0 && ityp.types == nil && len(ityp.embeddeds) == 0 {
-		// empty interface
-		ityp.allMethods = markComplete
-		return
-	}
-
-	// sort for API stability
-	sortMethods(ityp.methods)
-	sortTypes(ityp.embeddeds)
-
-	check.later(func() { check.completeInterface(iface.Pos(), ityp) })
-}
-
-func (check *Checker) completeInterface(pos syntax.Pos, ityp *Interface) {
-	if ityp.allMethods != nil {
-		return
-	}
-
-	// completeInterface may be called via the LookupFieldOrMethod,
-	// MissingMethod, Identical, or IdenticalIgnoreTags external API
-	// in which case check will be nil. In this case, type-checking
-	// must be finished and all interfaces should have been completed.
-	if check == nil {
-		panic("internal error: incomplete interface")
-	}
-
-	if check.conf.Trace {
-		// Types don't generally have position information.
-		// If we don't have a valid pos provided, try to use
-		// one close enough.
-		if !pos.IsKnown() && len(ityp.methods) > 0 {
-			pos = ityp.methods[0].pos
-		}
-
-		check.trace(pos, "complete %s", ityp)
-		check.indent++
-		defer func() {
-			check.indent--
-			check.trace(pos, "=> %s (methods = %v, types = %v)", ityp, ityp.allMethods, ityp.allTypes)
-		}()
-	}
-
-	// An infinitely expanding interface (due to a cycle) is detected
-	// elsewhere (Checker.validType), so here we simply assume we only
-	// have valid interfaces. Mark the interface as complete to avoid
-	// infinite recursion if the validType check occurs later for some
-	// reason.
-	ityp.allMethods = markComplete
-
-	// Methods of embedded interfaces are collected unchanged; i.e., the identity
-	// of a method I.m's Func Object of an interface I is the same as that of
-	// the method m in an interface that embeds interface I. On the other hand,
-	// if a method is embedded via multiple overlapping embedded interfaces, we
-	// don't provide a guarantee which "original m" got chosen for the embedding
-	// interface. See also issue #34421.
-	//
-	// If we don't care to provide this identity guarantee anymore, instead of
-	// reusing the original method in embeddings, we can clone the method's Func
-	// Object and give it the position of a corresponding embedded interface. Then
-	// we can get rid of the mpos map below and simply use the cloned method's
-	// position.
-
-	var seen objset
-	var methods []*Func
-	mpos := make(map[*Func]syntax.Pos) // method specification or method embedding position, for good error messages
-	addMethod := func(pos syntax.Pos, m *Func, explicit bool) {
-		switch other := seen.insert(m); {
-		case other == nil:
-			methods = append(methods, m)
-			mpos[m] = pos
-		case explicit:
-			var err error_
-			err.errorf(pos, "duplicate method %s", m.name)
-			err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
-			check.report(&err)
-		default:
-			// We have a duplicate method name in an embedded (not explicitly declared) method.
-			// Check method signatures after all types are computed (issue #33656).
-			// If we're pre-go1.14 (overlapping embeddings are not permitted), report that
-			// error here as well (even though we could do it eagerly) because it's the same
-			// error message.
-			check.later(func() {
-				if !check.allowVersion(m.pkg, 1, 14) || !check.identical(m.typ, other.Type()) {
-					var err error_
-					err.errorf(pos, "duplicate method %s", m.name)
-					err.errorf(mpos[other.(*Func)], "other declaration of %s", m.name)
-					check.report(&err)
-				}
-			})
-		}
-	}
-
-	for _, m := range ityp.methods {
-		addMethod(m.pos, m, true)
-	}
-
-	// collect types
-	allTypes := ityp.types
-
-	posList := check.posMap[ityp]
-	for i, typ := range ityp.embeddeds {
-		pos := posList[i] // embedding position
-		utyp := under(typ)
-		etyp := asInterface(utyp)
-		if etyp == nil {
-			if utyp != Typ[Invalid] {
-				var format string
-				if _, ok := utyp.(*TypeParam); ok {
-					format = "%s is a type parameter, not an interface"
-				} else {
-					format = "%s is not an interface"
-				}
-				check.errorf(pos, format, typ)
-			}
-			continue
-		}
-		check.completeInterface(pos, etyp)
-		for _, m := range etyp.allMethods {
-			addMethod(pos, m, false) // use embedding position pos rather than m.pos
-		}
-		allTypes = intersect(allTypes, etyp.allTypes)
-	}
-
-	if methods != nil {
-		sortMethods(methods)
-		ityp.allMethods = methods
-	}
-	ityp.allTypes = allTypes
-}
-
-// intersect computes the intersection of the types x and y.
-// Note: A incomming nil type stands for the top type. A top
-// type result is returned as nil.
-func intersect(x, y Type) (r Type) {
-	defer func() {
-		if r == theTop {
-			r = nil
-		}
-	}()
-
-	switch {
-	case x == theBottom || y == theBottom:
-		return theBottom
-	case x == nil || x == theTop:
-		return y
-	case y == nil || x == theTop:
-		return x
-	}
-
-	xtypes := unpack(x)
-	ytypes := unpack(y)
-	// Compute the list rtypes which includes only
-	// types that are in both xtypes and ytypes.
-	// Quadratic algorithm, but good enough for now.
-	// TODO(gri) fix this
-	var rtypes []Type
-	for _, x := range xtypes {
-		if includes(ytypes, x) {
-			rtypes = append(rtypes, x)
-		}
-	}
-
-	if rtypes == nil {
-		return theBottom
-	}
-	return NewSum(rtypes)
-}
-
-func sortTypes(list []Type) {
-	sort.Stable(byUniqueTypeName(list))
-}
-
-// byUniqueTypeName named type lists can be sorted by their unique type names.
-type byUniqueTypeName []Type
-
-func (a byUniqueTypeName) Len() int           { return len(a) }
-func (a byUniqueTypeName) Less(i, j int) bool { return sortName(a[i]) < sortName(a[j]) }
-func (a byUniqueTypeName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
-func sortName(t Type) string {
-	if named := asNamed(t); named != nil {
-		return named.obj.Id()
-	}
-	return ""
-}
-
-func sortMethods(list []*Func) {
-	sort.Sort(byUniqueMethodName(list))
-}
-
-func assertSortedMethods(list []*Func) {
-	if !debug {
-		panic("internal error: assertSortedMethods called outside debug mode")
-	}
-	if !sort.IsSorted(byUniqueMethodName(list)) {
-		panic("internal error: methods not sorted")
-	}
-}
-
-// byUniqueMethodName method lists can be sorted by their unique method names.
-type byUniqueMethodName []*Func
-
-func (a byUniqueMethodName) Len() int           { return len(a) }
-func (a byUniqueMethodName) Less(i, j int) bool { return a[i].less(a[j]) }
-func (a byUniqueMethodName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
-func (check *Checker) tag(t *syntax.BasicLit) string {
-	// If t.Bad, an error was reported during parsing.
-	if t != nil && !t.Bad {
-		if t.Kind == syntax.StringLit {
-			if val, err := strconv.Unquote(t.Value); err == nil {
-				return val
-			}
-		}
-		check.errorf(t, invalidAST+"incorrect tag syntax: %q", t.Value)
-	}
-	return ""
-}
-
-func (check *Checker) structType(styp *Struct, e *syntax.StructType) {
-	if e.FieldList == nil {
-		return
-	}
-
-	// struct fields and tags
-	var fields []*Var
-	var tags []string
-
-	// for double-declaration checks
-	var fset objset
-
-	// current field typ and tag
-	var typ Type
-	var tag string
-	add := func(ident *syntax.Name, embedded bool, pos syntax.Pos) {
-		if tag != "" && tags == nil {
-			tags = make([]string, len(fields))
-		}
-		if tags != nil {
-			tags = append(tags, tag)
-		}
-
-		name := ident.Value
-		fld := NewField(pos, check.pkg, name, typ, embedded)
-		// spec: "Within a struct, non-blank field names must be unique."
-		if name == "_" || check.declareInSet(&fset, pos, fld) {
-			fields = append(fields, fld)
-			check.recordDef(ident, fld)
-		}
-	}
-
-	// addInvalid adds an embedded field of invalid type to the struct for
-	// fields with errors; this keeps the number of struct fields in sync
-	// with the source as long as the fields are _ or have different names
-	// (issue #25627).
-	addInvalid := func(ident *syntax.Name, pos syntax.Pos) {
-		typ = Typ[Invalid]
-		tag = ""
-		add(ident, true, pos)
-	}
-
-	var prev syntax.Expr
-	for i, f := range e.FieldList {
-		// Fields declared syntactically with the same type (e.g.: a, b, c T)
-		// share the same type expression. Only check type if it's a new type.
-		if i == 0 || f.Type != prev {
-			typ = check.varType(f.Type)
-			prev = f.Type
-		}
-		tag = ""
-		if i < len(e.TagList) {
-			tag = check.tag(e.TagList[i])
-		}
-		if f.Name != nil {
-			// named field
-			add(f.Name, false, f.Name.Pos())
-		} else {
-			// embedded field
-			// spec: "An embedded type must be specified as a type name T or as a
-			// pointer to a non-interface type name *T, and T itself may not be a
-			// pointer type."
-			pos := syntax.StartPos(f.Type)
-			name := embeddedFieldIdent(f.Type)
-			if name == nil {
-				check.errorf(pos, "invalid embedded field type %s", f.Type)
-				name = &syntax.Name{Value: "_"} // TODO(gri) need to set position to pos
-				addInvalid(name, pos)
-				continue
-			}
-			add(name, true, pos)
-
-			// Because we have a name, typ must be of the form T or *T, where T is the name
-			// of a (named or alias) type, and t (= deref(typ)) must be the type of T.
-			// We must delay this check to the end because we don't want to instantiate
-			// (via under(t)) a possibly incomplete type.
-			embeddedTyp := typ // for closure below
-			embeddedPos := pos
-			check.later(func() {
-				t, isPtr := deref(embeddedTyp)
-				switch t := optype(t).(type) {
-				case *Basic:
-					if t == Typ[Invalid] {
-						// error was reported before
-						return
-					}
-					// unsafe.Pointer is treated like a regular pointer
-					if t.kind == UnsafePointer {
-						check.error(embeddedPos, "embedded field type cannot be unsafe.Pointer")
-					}
-				case *Pointer:
-					check.error(embeddedPos, "embedded field type cannot be a pointer")
-				case *Interface:
-					if isPtr {
-						check.error(embeddedPos, "embedded field type cannot be a pointer to an interface")
-					}
-				}
-			})
-		}
-	}
-
-	styp.fields = fields
-	styp.tags = tags
-}
-
-func embeddedFieldIdent(e syntax.Expr) *syntax.Name {
-	switch e := e.(type) {
-	case *syntax.Name:
-		return e
-	case *syntax.Operation:
-		if base := ptrBase(e); base != nil {
-			// *T is valid, but **T is not
-			if op, _ := base.(*syntax.Operation); op == nil || ptrBase(op) == nil {
-				return embeddedFieldIdent(e.X)
-			}
-		}
-	case *syntax.SelectorExpr:
-		return e.Sel
-	case *syntax.IndexExpr:
-		return embeddedFieldIdent(e.X)
-	}
-	return nil // invalid embedded field
-}
-
-func (check *Checker) collectTypeConstraints(pos syntax.Pos, types []syntax.Expr) []Type {
-	list := make([]Type, 0, len(types)) // assume all types are correct
-	for _, texpr := range types {
-		if texpr == nil {
-			check.error(pos, invalidAST+"missing type constraint")
-			continue
-		}
-		list = append(list, check.varType(texpr))
-	}
-
-	// Ensure that each type is only present once in the type list.  Types may be
-	// interfaces, which may not be complete yet. It's ok to do this check at the
-	// end because it's not a requirement for correctness of the code.
-	// Note: This is a quadratic algorithm, but type lists tend to be short.
-	check.later(func() {
-		for i, t := range list {
-			if t := asInterface(t); t != nil {
-				check.completeInterface(types[i].Pos(), t)
-			}
-			if includes(list[:i], t) {
-				check.softErrorf(types[i], "duplicate type %s in type list", t)
-			}
-		}
-	})
-
-	return list
-}
-
-// includes reports whether typ is in list
-func includes(list []Type, typ Type) bool {
-	for _, e := range list {
-		if Identical(typ, e) {
-			return true
-		}
-	}
-	return false
-}
-
-func ptrBase(x *syntax.Operation) syntax.Expr {
-	if x.Op == syntax.Mul && x.Y == nil {
-		return x.X
-	}
-	return nil
-}
diff --git a/src/cmd/compile/internal/types2/unify.go b/src/cmd/compile/internal/types2/unify.go
index e1832bbb2a3..710fc51b53f 100644
--- a/src/cmd/compile/internal/types2/unify.go
+++ b/src/cmd/compile/internal/types2/unify.go
@@ -6,7 +6,10 @@
 
 package types2
 
-import "bytes"
+import (
+	"bytes"
+	"fmt"
+)
 
 // The unifier maintains two separate sets of type parameters x and y
 // which are used to resolve type parameters in the x and y arguments
@@ -34,7 +37,6 @@ import "bytes"
 // and the respective types inferred for each type parameter.
 // A unifier is created by calling newUnifier.
 type unifier struct {
-	check *Checker
 	exact bool
 	x, y  tparamsList // x and y must initialized via tparamsList.init
 	types []Type      // inferred types, shared by x and y
@@ -45,8 +47,8 @@ type unifier struct {
 // exactly. If exact is not set, a named type's underlying type
 // is considered if unification would fail otherwise, and the
 // direction of channels is ignored.
-func newUnifier(check *Checker, exact bool) *unifier {
-	u := &unifier{check: check, exact: exact}
+func newUnifier(exact bool) *unifier {
+	u := &unifier{exact: exact}
 	u.x.unifier = u
 	u.y.unifier = u
 	return u
@@ -148,10 +150,17 @@ func (u *unifier) join(i, j int) bool {
 // If typ is a type parameter of d, index returns the type parameter index.
 // Otherwise, the result is < 0.
 func (d *tparamsList) index(typ Type) int {
-	if t, ok := typ.(*TypeParam); ok {
-		if i := t.index; i < len(d.tparams) && d.tparams[i].typ == t {
-			return i
-		}
+	if tpar, ok := typ.(*TypeParam); ok {
+		return tparamIndex(d.tparams, tpar)
+	}
+	return -1
+}
+
+// If tpar is a type parameter in list, tparamIndex returns the type parameter index.
+// Otherwise, the result is < 0. tpar must not be nil.
+func tparamIndex(list []*TypeName, tpar *TypeParam) int {
+	if i := tpar.index; i < len(list) && list[i].typ == tpar {
+		return i
 	}
 	return -1
 }
@@ -220,10 +229,6 @@ func (u *unifier) nifyEq(x, y Type, p *ifacePair) bool {
 // code the corresponding changes should be made here.
 // Must not be called directly from outside the unifier.
 func (u *unifier) nify(x, y Type, p *ifacePair) bool {
-	// types must be expanded for comparison
-	x = expand(x)
-	y = expand(y)
-
 	if !u.exact {
 		// If exact unification is known to fail because we attempt to
 		// match a type name against an unnamed type literal, consider
@@ -352,25 +357,18 @@ func (u *unifier) nify(x, y Type, p *ifacePair) bool {
 				u.nify(x.results, y.results, p)
 		}
 
-	case *Sum:
-		// This should not happen with the current internal use of sum types.
-		panic("type inference across sum types not implemented")
-
 	case *Interface:
 		// Two interface types are identical if they have the same set of methods with
 		// the same names and identical function types. Lower-case method names from
 		// different packages are always different. The order of the methods is irrelevant.
 		if y, ok := y.(*Interface); ok {
-			// If identical0 is called (indirectly) via an external API entry point
-			// (such as Identical, IdenticalIgnoreTags, etc.), check is nil. But in
-			// that case, interfaces are expected to be complete and lazy completion
-			// here is not needed.
-			if u.check != nil {
-				u.check.completeInterface(nopos, x)
-				u.check.completeInterface(nopos, y)
+			xset := x.typeSet()
+			yset := y.typeSet()
+			if !xset.terms.equal(yset.terms) {
+				return false
 			}
-			a := x.allMethods
-			b := y.allMethods
+			a := xset.methods
+			b := yset.methods
 			if len(a) == len(b) {
 				// Interface types are the only types where cycles can occur
 				// that are not "terminated" via named types; and such cycles
@@ -428,12 +426,9 @@ func (u *unifier) nify(x, y Type, p *ifacePair) bool {
 		}
 
 	case *Named:
-		// Two named types are identical if their type names originate
-		// in the same type declaration.
-		// if y, ok := y.(*Named); ok {
-		// 	return x.obj == y.obj
-		// }
 		if y, ok := y.(*Named); ok {
+			x.expand(nil)
+			y.expand(nil)
 			// TODO(gri) This is not always correct: two types may have the same names
 			//           in the same package if one of them is nested in a function.
 			//           Extremely unlikely but we need an always correct solution.
@@ -454,15 +449,11 @@ func (u *unifier) nify(x, y Type, p *ifacePair) bool {
 		// are identical if they originate in the same declaration.
 		return x == y
 
-	// case *instance:
-	//	unreachable since types are expanded
-
 	case nil:
 		// avoid a crash in case of nil type
 
 	default:
-		u.check.dump("### u.nify(%s, %s), u.x.tparams = %s", x, y, u.x.tparams)
-		unreachable()
+		panic(fmt.Sprintf("### u.nify(%s, %s), u.x.tparams = %s", x, y, u.x.tparams))
 	}
 
 	return false
diff --git a/src/cmd/compile/internal/types2/union.go b/src/cmd/compile/internal/types2/union.go
new file mode 100644
index 00000000000..f61c37a6afd
--- /dev/null
+++ b/src/cmd/compile/internal/types2/union.go
@@ -0,0 +1,150 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types2
+
+import "cmd/compile/internal/syntax"
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Union represents a union of terms embedded in an interface.
+type Union struct {
+	terms []*Term  // list of syntactical terms (not a canonicalized termlist)
+	tset  *TypeSet // type set described by this union, computed lazily
+}
+
+// NewUnion returns a new Union type with the given terms.
+// It is an error to create an empty union; they are syntactically not possible.
+func NewUnion(terms []*Term) *Union {
+	if len(terms) == 0 {
+		panic("empty union")
+	}
+	return &Union{terms, nil}
+}
+
+func (u *Union) Len() int         { return len(u.terms) }
+func (u *Union) Term(i int) *Term { return u.terms[i] }
+
+func (u *Union) Underlying() Type { return u }
+func (u *Union) String() string   { return TypeString(u, nil) }
+
+// A Term represents a term in a Union.
+type Term term
+
+// NewTerm returns a new union term.
+func NewTerm(tilde bool, typ Type) *Term { return &Term{tilde, typ} }
+
+func (t *Term) Tilde() bool    { return t.tilde }
+func (t *Term) Type() Type     { return t.typ }
+func (t *Term) String() string { return (*term)(t).String() }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// Avoid excessive type-checking times due to quadratic termlist operations.
+const maxTermCount = 100
+
+// parseUnion parses the given list of type expressions tlist as a union of
+// those expressions. The result is a Union type, or Typ[Invalid] for some
+// errors.
+func parseUnion(check *Checker, tlist []syntax.Expr) Type {
+	var terms []*Term
+	for _, x := range tlist {
+		tilde, typ := parseTilde(check, x)
+		if len(tlist) == 1 && !tilde {
+			return typ // single type (optimization)
+		}
+		if len(terms) >= maxTermCount {
+			check.errorf(x, "cannot handle more than %d union terms (implementation limitation)", maxTermCount)
+			return Typ[Invalid]
+		}
+		terms = append(terms, NewTerm(tilde, typ))
+	}
+
+	// Check validity of terms.
+	// Do this check later because it requires types to be set up.
+	// Note: This is a quadratic algorithm, but unions tend to be short.
+	check.later(func() {
+		for i, t := range terms {
+			if t.typ == Typ[Invalid] {
+				continue
+			}
+
+			x := tlist[i]
+			pos := syntax.StartPos(x)
+			// We may not know the position of x if it was a typechecker-
+			// introduced ~T term for a type list entry T. Use the position
+			// of T instead.
+			// TODO(gri) remove this test once we don't support type lists anymore
+			if !pos.IsKnown() {
+				if op, _ := x.(*syntax.Operation); op != nil {
+					pos = syntax.StartPos(op.X)
+				}
+			}
+
+			u := under(t.typ)
+			f, _ := u.(*Interface)
+			if t.tilde {
+				if f != nil {
+					check.errorf(x, "invalid use of ~ (%s is an interface)", t.typ)
+					continue // don't report another error for t
+				}
+
+				if !Identical(u, t.typ) {
+					check.errorf(x, "invalid use of ~ (underlying type of %s is %s)", t.typ, u)
+					continue // don't report another error for t
+				}
+			}
+
+			// Stand-alone embedded interfaces are ok and are handled by the single-type case
+			// in the beginning. Embedded interfaces with tilde are excluded above. If we reach
+			// here, we must have at least two terms in the union.
+			if f != nil && !f.typeSet().IsTypeSet() {
+				check.errorf(pos, "cannot use %s in union (interface contains methods)", t)
+				continue // don't report another error for t
+			}
+
+			// Report overlapping (non-disjoint) terms such as
+			// a|a, a|~a, ~a|~a, and ~a|A (where under(A) == a).
+			if j := overlappingTerm(terms[:i], t); j >= 0 {
+				check.softErrorf(pos, "overlapping terms %s and %s", t, terms[j])
+			}
+		}
+	})
+
+	return &Union{terms, nil}
+}
+
+func parseTilde(check *Checker, x syntax.Expr) (tilde bool, typ Type) {
+	if op, _ := x.(*syntax.Operation); op != nil && op.Op == syntax.Tilde {
+		x = op.X
+		tilde = true
+	}
+	typ = check.anyType(x)
+	// embedding stand-alone type parameters is not permitted (issue #47127).
+	if _, ok := under(typ).(*TypeParam); ok {
+		check.error(x, "cannot embed a type parameter")
+		typ = Typ[Invalid]
+	}
+	return
+}
+
+// overlappingTerm reports the index of the term x in terms which is
+// overlapping (not disjoint) from y. The result is < 0 if there is no
+// such term.
+func overlappingTerm(terms []*Term, y *Term) int {
+	for i, x := range terms {
+		// disjoint requires non-nil, non-top arguments
+		if debug {
+			if x == nil || x.typ == nil || y == nil || y.typ == nil {
+				panic("empty or top union term")
+			}
+		}
+		if !(*term)(x).disjoint((*term)(y)) {
+			return i
+		}
+	}
+	return -1
+}
diff --git a/src/cmd/compile/internal/types2/universe.go b/src/cmd/compile/internal/types2/universe.go
index 76d4e55e84b..f14c0792229 100644
--- a/src/cmd/compile/internal/types2/universe.go
+++ b/src/cmd/compile/internal/types2/universe.go
@@ -20,11 +20,12 @@ var Universe *Scope
 var Unsafe *Package
 
 var (
-	universeIota  *Const
-	universeByte  *Basic // uint8 alias, but has name "byte"
-	universeRune  *Basic // int32 alias, but has name "rune"
-	universeAny   *Interface
-	universeError *Named
+	universeIota       Object
+	universeByte       Type // uint8 alias, but has name "byte"
+	universeRune       Type // int32 alias, but has name "rune"
+	universeAny        Object
+	universeError      Type
+	universeComparable Object
 )
 
 // Typ contains the predeclared *Basic types indexed by their
@@ -77,20 +78,30 @@ func defPredeclaredTypes() {
 		def(NewTypeName(nopos, nil, t.name, t))
 	}
 
-	// any
-	// (Predeclared and entered into universe scope so we do all the
-	// usual checks; but removed again from scope later since it's
-	// only visible as constraint in a type parameter list.)
+	// type any = interface{}
 	def(NewTypeName(nopos, nil, "any", &emptyInterface))
 
-	// Error has a nil package in its qualified name since it is in no package
+	// type error interface{ Error() string }
 	{
+		obj := NewTypeName(nopos, nil, "error", nil)
+		obj.setColor(black)
 		res := NewVar(nopos, nil, "", Typ[String])
-		sig := &Signature{results: NewTuple(res)}
+		sig := NewSignature(nil, nil, NewTuple(res), false)
 		err := NewFunc(nopos, nil, "Error", sig)
-		typ := &Named{underlying: NewInterfaceType([]*Func{err}, nil).Complete()}
+		ityp := &Interface{obj, []*Func{err}, nil, nil, true, nil}
+		computeInterfaceTypeSet(nil, nopos, ityp) // prevent races due to lazy computation of tset
+		typ := NewNamed(obj, ityp, nil)
 		sig.recv = NewVar(nopos, nil, "", typ)
-		def(NewTypeName(nopos, nil, "error", typ))
+		def(obj)
+	}
+
+	// type comparable interface{ /* type set marked comparable */ }
+	{
+		obj := NewTypeName(nopos, nil, "comparable", nil)
+		obj.setColor(black)
+		ityp := &Interface{obj, nil, nil, nil, true, &TypeSet{true, nil, allTermlist}}
+		NewNamed(obj, ityp, nil)
+		def(obj)
 	}
 }
 
@@ -200,33 +211,6 @@ func DefPredeclaredTestFuncs() {
 	def(newBuiltin(_Trace))
 }
 
-func defPredeclaredComparable() {
-	// The "comparable" interface can be imagined as defined like
-	//
-	// type comparable interface {
-	//         == () untyped bool
-	//         != () untyped bool
-	// }
-	//
-	// == and != cannot be user-declared but we can declare
-	// a magic method == and check for its presence when needed.
-
-	// Define interface { == () }. We don't care about the signature
-	// for == so leave it empty except for the receiver, which is
-	// set up later to match the usual interface method assumptions.
-	sig := new(Signature)
-	eql := NewFunc(nopos, nil, "==", sig)
-	iface := NewInterfaceType([]*Func{eql}, nil).Complete()
-
-	// set up the defined type for the interface
-	obj := NewTypeName(nopos, nil, "comparable", nil)
-	named := NewNamed(obj, iface, nil)
-	obj.color_ = black
-	sig.recv = NewVar(nopos, nil, "", named) // complete == signature
-
-	def(obj)
-}
-
 func init() {
 	Universe = NewScope(nil, nopos, nopos, "universe")
 	Unsafe = NewPackage("unsafe", "unsafe")
@@ -236,16 +220,13 @@ func init() {
 	defPredeclaredConsts()
 	defPredeclaredNil()
 	defPredeclaredFuncs()
-	defPredeclaredComparable()
 
-	universeIota = Universe.Lookup("iota").(*Const)
-	universeByte = Universe.Lookup("byte").(*TypeName).typ.(*Basic)
-	universeRune = Universe.Lookup("rune").(*TypeName).typ.(*Basic)
-	universeAny = Universe.Lookup("any").(*TypeName).typ.(*Interface)
-	universeError = Universe.Lookup("error").(*TypeName).typ.(*Named)
-
-	// "any" is only visible as constraint in a type parameter list
-	delete(Universe.elems, "any")
+	universeIota = Universe.Lookup("iota")
+	universeByte = Universe.Lookup("byte").Type()
+	universeRune = Universe.Lookup("rune").Type()
+	universeAny = Universe.Lookup("any")
+	universeError = Universe.Lookup("error").Type()
+	universeComparable = Universe.Lookup("comparable")
 }
 
 // Objects with names containing blanks are internal and not entered into
@@ -277,6 +258,6 @@ func def(obj Object) {
 		}
 	}
 	if scope.Insert(obj) != nil {
-		panic("internal error: double declaration")
+		panic("double declaration of predeclared identifier")
 	}
 }
diff --git a/src/cmd/compile/internal/walk/assign.go b/src/cmd/compile/internal/walk/assign.go
index 6d697a53ae3..d4c1aafdc12 100644
--- a/src/cmd/compile/internal/walk/assign.go
+++ b/src/cmd/compile/internal/walk/assign.go
@@ -429,6 +429,7 @@ func readsMemory(n ir.Node) bool {
 		ir.OBITNOT,
 		ir.OCONV,
 		ir.OCONVIFACE,
+		ir.OCONVIDATA,
 		ir.OCONVNOP,
 		ir.ODIV,
 		ir.ODOT,
diff --git a/src/cmd/compile/internal/walk/builtin.go b/src/cmd/compile/internal/walk/builtin.go
index 62eb4298f4d..af4f8f48228 100644
--- a/src/cmd/compile/internal/walk/builtin.go
+++ b/src/cmd/compile/internal/walk/builtin.go
@@ -489,7 +489,7 @@ func walkNew(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
 		base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", n.Type().Elem())
 	}
 	if n.Esc() == ir.EscNone {
-		if t.Size() >= ir.MaxImplicitStackVarSize {
+		if t.Size() > ir.MaxImplicitStackVarSize {
 			base.Fatalf("large ONEW with EscNone: %v", n)
 		}
 		return stackTempAddr(init, t)
@@ -641,49 +641,34 @@ func walkPrint(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
 	return walkStmt(typecheck.Stmt(r))
 }
 
-// walkRecover walks an ORECOVER node.
-func walkRecover(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
-	// Call gorecover with the FP of this frame.
-	// FP is equal to caller's SP plus FixedFrameSize().
-	var fp ir.Node = mkcall("getcallersp", types.Types[types.TUINTPTR], init)
-	if off := base.Ctxt.FixedFrameSize(); off != 0 {
-		fp = ir.NewBinaryExpr(fp.Pos(), ir.OADD, fp, ir.NewInt(off))
-	}
-	fp = ir.NewConvExpr(fp.Pos(), ir.OCONVNOP, types.NewPtr(types.Types[types.TINT32]), fp)
-	return mkcall("gorecover", nn.Type(), init, fp)
+// walkRecover walks an ORECOVERFP node.
+func walkRecoverFP(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
+	return mkcall("gorecover", nn.Type(), init, walkExpr(nn.Args[0], init))
 }
 
 func walkUnsafeSlice(n *ir.BinaryExpr, init *ir.Nodes) ir.Node {
+	ptr := safeExpr(n.X, init)
 	len := safeExpr(n.Y, init)
 
 	fnname := "unsafeslice64"
-	argtype := types.Types[types.TINT64]
+	lenType := types.Types[types.TINT64]
 
 	// Type checking guarantees that TIDEAL len/cap are positive and fit in an int.
 	// The case of len or cap overflow when converting TUINT or TUINTPTR to TINT
 	// will be handled by the negative range checks in unsafeslice during runtime.
-	if len.Type().IsKind(types.TIDEAL) || len.Type().Size() <= types.Types[types.TUINT].Size() {
+	if ir.ShouldCheckPtr(ir.CurFunc, 1) {
+		fnname = "unsafeslicecheckptr"
+		// for simplicity, unsafeslicecheckptr always uses int64
+	} else if len.Type().IsKind(types.TIDEAL) || len.Type().Size() <= types.Types[types.TUINT].Size() {
 		fnname = "unsafeslice"
-		argtype = types.Types[types.TINT]
+		lenType = types.Types[types.TINT]
 	}
 
 	t := n.Type()
 
-	// Call runtime.unsafeslice[64] to check that the length argument is
-	// non-negative and smaller than the max length allowed for the
-	// element type.
+	// Call runtime.unsafeslice{,64,checkptr} to check ptr and len.
 	fn := typecheck.LookupRuntime(fnname)
-	init.Append(mkcall1(fn, nil, init, reflectdata.TypePtr(t.Elem()), typecheck.Conv(len, argtype)))
-
-	ptr := walkExpr(n.X, init)
-
-	c := ir.NewUnaryExpr(n.Pos(), ir.OCHECKNIL, ptr)
-	c.SetTypecheck(1)
-	init.Append(c)
-
-	// TODO(mdempsky): checkptr instrumentation. Maybe merge into length
-	// check above, along with nil check? Need to be careful about
-	// notinheap pointers though: can't pass them as unsafe.Pointer.
+	init.Append(mkcall1(fn, nil, init, reflectdata.TypePtr(t.Elem()), typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR]), typecheck.Conv(len, lenType)))
 
 	h := ir.NewSliceHeaderExpr(n.Pos(), t,
 		typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR]),
diff --git a/src/cmd/compile/internal/walk/closure.go b/src/cmd/compile/internal/walk/closure.go
index 2194e1c5b0c..902e01ef388 100644
--- a/src/cmd/compile/internal/walk/closure.go
+++ b/src/cmd/compile/internal/walk/closure.go
@@ -37,14 +37,6 @@ func directClosureCall(n *ir.CallExpr) {
 		return // leave for walkClosure to handle
 	}
 
-	// If wrapGoDefer() in the order phase has flagged this call,
-	// avoid eliminating the closure even if there is a direct call to
-	// (the closure is needed to simplify the register ABI). See
-	// wrapGoDefer for more details.
-	if n.PreserveClosure {
-		return
-	}
-
 	// We are going to insert captured variables before input args.
 	var params []*types.Field
 	var decls []*ir.Name
@@ -122,6 +114,9 @@ func walkClosure(clo *ir.ClosureExpr, init *ir.Nodes) ir.Node {
 	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
 	clos.SetEsc(clo.Esc())
 	clos.List = append([]ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, clofn.Nname)}, closureArgs(clo)...)
+	for i, value := range clos.List {
+		clos.List[i] = ir.NewStructKeyExpr(base.Pos, typ.Field(i), value)
+	}
 
 	addr := typecheck.NodAddr(clos)
 	addr.SetEsc(clo.Esc())
@@ -161,7 +156,7 @@ func closureArgs(clo *ir.ClosureExpr) []ir.Node {
 	return args
 }
 
-func walkCallPart(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
+func walkMethodValue(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
 	// Create closure in the form of a composite literal.
 	// For x.M with receiver (x) type T, the generated code looks like:
 	//
@@ -175,18 +170,16 @@ func walkCallPart(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
 		n.X = cheapExpr(n.X, init)
 		n.X = walkExpr(n.X, nil)
 
-		tab := typecheck.Expr(ir.NewUnaryExpr(base.Pos, ir.OITAB, n.X))
-
-		c := ir.NewUnaryExpr(base.Pos, ir.OCHECKNIL, tab)
-		c.SetTypecheck(1)
-		init.Append(c)
+		tab := ir.NewUnaryExpr(base.Pos, ir.OITAB, n.X)
+		check := ir.NewUnaryExpr(base.Pos, ir.OCHECKNIL, tab)
+		init.Append(typecheck.Stmt(check))
 	}
 
-	typ := typecheck.PartialCallType(n)
+	typ := typecheck.MethodValueType(n)
 
 	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
 	clos.SetEsc(n.Esc())
-	clos.List = []ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, typecheck.MethodValueWrapper(n).Nname), n.X}
+	clos.List = []ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, methodValueWrapper(n)), n.X}
 
 	addr := typecheck.NodAddr(clos)
 	addr.SetEsc(n.Esc())
@@ -205,3 +198,74 @@ func walkCallPart(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
 
 	return walkExpr(cfn, init)
 }
+
+// methodValueWrapper returns the ONAME node representing the
+// wrapper function (*-fm) needed for the given method value. If the
+// wrapper function hasn't already been created yet, it's created and
+// added to typecheck.Target.Decls.
+func methodValueWrapper(dot *ir.SelectorExpr) *ir.Name {
+	if dot.Op() != ir.OMETHVALUE {
+		base.Fatalf("methodValueWrapper: unexpected %v (%v)", dot, dot.Op())
+	}
+
+	t0 := dot.Type()
+	meth := dot.Sel
+	rcvrtype := dot.X.Type()
+	sym := ir.MethodSymSuffix(rcvrtype, meth, "-fm")
+
+	if sym.Uniq() {
+		return sym.Def.(*ir.Name)
+	}
+	sym.SetUniq(true)
+
+	savecurfn := ir.CurFunc
+	saveLineNo := base.Pos
+	ir.CurFunc = nil
+
+	// Set line number equal to the line number where the method is declared.
+	if pos := dot.Selection.Pos; pos.IsKnown() {
+		base.Pos = pos
+	}
+	// Note: !dot.Selection.Pos.IsKnown() happens for method expressions where
+	// the method is implicitly declared. The Error method of the
+	// built-in error type is one such method.  We leave the line
+	// number at the use of the method expression in this
+	// case. See issue 29389.
+
+	tfn := ir.NewFuncType(base.Pos, nil,
+		typecheck.NewFuncParams(t0.Params(), true),
+		typecheck.NewFuncParams(t0.Results(), false))
+
+	fn := typecheck.DeclFunc(sym, tfn)
+	fn.SetDupok(true)
+	fn.SetWrapper(true)
+
+	// Declare and initialize variable holding receiver.
+	ptr := ir.NewHiddenParam(base.Pos, fn, typecheck.Lookup(".this"), rcvrtype)
+
+	call := ir.NewCallExpr(base.Pos, ir.OCALL, ir.NewSelectorExpr(base.Pos, ir.OXDOT, ptr, meth), nil)
+	call.Args = ir.ParamNames(tfn.Type())
+	call.IsDDD = tfn.Type().IsVariadic()
+
+	var body ir.Node = call
+	if t0.NumResults() != 0 {
+		ret := ir.NewReturnStmt(base.Pos, nil)
+		ret.Results = []ir.Node{call}
+		body = ret
+	}
+
+	fn.Body = []ir.Node{body}
+	typecheck.FinishFuncBody()
+
+	typecheck.Func(fn)
+	// Need to typecheck the body of the just-generated wrapper.
+	// typecheckslice() requires that Curfn is set when processing an ORETURN.
+	ir.CurFunc = fn
+	typecheck.Stmts(fn.Body)
+	sym.Def = fn.Nname
+	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+	ir.CurFunc = savecurfn
+	base.Pos = saveLineNo
+
+	return fn.Nname
+}
diff --git a/src/cmd/compile/internal/walk/complit.go b/src/cmd/compile/internal/walk/complit.go
index abd920d6461..6c6b4982a05 100644
--- a/src/cmd/compile/internal/walk/complit.go
+++ b/src/cmd/compile/internal/walk/complit.go
@@ -218,11 +218,11 @@ func fixedlit(ctxt initContext, kind initKind, n *ir.CompLitExpr, var_ ir.Node,
 	case ir.OSTRUCTLIT:
 		splitnode = func(rn ir.Node) (ir.Node, ir.Node) {
 			r := rn.(*ir.StructKeyExpr)
-			if r.Field.IsBlank() || isBlank {
+			if r.Sym().IsBlank() || isBlank {
 				return ir.BlankNode, r.Value
 			}
 			ir.SetPos(r)
-			return ir.NewSelectorExpr(base.Pos, ir.ODOT, var_, r.Field), r.Value
+			return ir.NewSelectorExpr(base.Pos, ir.ODOT, var_, r.Sym()), r.Value
 		}
 	default:
 		base.Fatalf("fixedlit bad op: %v", n.Op())
diff --git a/src/cmd/compile/internal/walk/convert.go b/src/cmd/compile/internal/walk/convert.go
index 26e17a126f2..27a07ce4b60 100644
--- a/src/cmd/compile/internal/walk/convert.go
+++ b/src/cmd/compile/internal/walk/convert.go
@@ -41,46 +41,98 @@ func walkConv(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 
 // walkConvInterface walks an OCONVIFACE node.
 func walkConvInterface(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
+
 	n.X = walkExpr(n.X, init)
 
 	fromType := n.X.Type()
 	toType := n.Type()
-
-	if !fromType.IsInterface() && !ir.IsBlank(ir.CurFunc.Nname) { // skip unnamed functions (func _())
+	if !fromType.IsInterface() && !ir.IsBlank(ir.CurFunc.Nname) {
+		// skip unnamed functions (func _())
 		reflectdata.MarkTypeUsedInInterface(fromType, ir.CurFunc.LSym)
 	}
 
-	// typeword generates the type word of the interface value.
-	typeword := func() ir.Node {
+	if !fromType.IsInterface() {
+		var typeWord ir.Node
 		if toType.IsEmptyInterface() {
-			return reflectdata.TypePtr(fromType)
+			typeWord = reflectdata.TypePtr(fromType)
+		} else {
+			typeWord = reflectdata.ITabAddr(fromType, toType)
 		}
-		return reflectdata.ITabAddr(fromType, toType)
-	}
-
-	// Optimize convT2E or convT2I as a two-word copy when T is pointer-shaped.
-	if types.IsDirectIface(fromType) {
-		l := ir.NewBinaryExpr(base.Pos, ir.OEFACE, typeword(), n.X)
+		l := ir.NewBinaryExpr(base.Pos, ir.OEFACE, typeWord, dataWord(n.X, init, n.Esc() != ir.EscNone))
 		l.SetType(toType)
 		l.SetTypecheck(n.Typecheck())
 		return l
 	}
+	if fromType.IsEmptyInterface() {
+		base.Fatalf("OCONVIFACE can't operate on an empty interface")
+	}
 
-	// Optimize convT2{E,I} for many cases in which T is not pointer-shaped,
-	// by using an existing addressable value identical to n.Left
-	// or creating one on the stack.
+	// Evaluate the input interface.
+	c := typecheck.Temp(fromType)
+	init.Append(ir.NewAssignStmt(base.Pos, c, n.X))
+
+	// Grab its parts.
+	itab := ir.NewUnaryExpr(base.Pos, ir.OITAB, c)
+	itab.SetType(types.Types[types.TUINTPTR].PtrTo())
+	itab.SetTypecheck(1)
+	data := ir.NewUnaryExpr(base.Pos, ir.OIDATA, c)
+	data.SetType(types.Types[types.TUINT8].PtrTo()) // Type is generic pointer - we're just passing it through.
+	data.SetTypecheck(1)
+
+	var typeWord ir.Node
+	if toType.IsEmptyInterface() {
+		// Implement interface to empty interface conversion.
+		// res = itab
+		// if res != nil {
+		//    res = res.type
+		// }
+		typeWord = typecheck.Temp(types.NewPtr(types.Types[types.TUINT8]))
+		init.Append(ir.NewAssignStmt(base.Pos, typeWord, itab))
+		nif := ir.NewIfStmt(base.Pos, typecheck.Expr(ir.NewBinaryExpr(base.Pos, ir.ONE, typeWord, typecheck.NodNil())), nil, nil)
+		nif.Body = []ir.Node{ir.NewAssignStmt(base.Pos, typeWord, itabType(typeWord))}
+		init.Append(nif)
+	} else {
+		// Must be converting I2I (more specific to less specific interface).
+		// res = convI2I(toType, itab)
+		fn := typecheck.LookupRuntime("convI2I")
+		types.CalcSize(fn.Type())
+		call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, nil)
+		call.Args = []ir.Node{reflectdata.TypePtr(toType), itab}
+		typeWord = walkExpr(typecheck.Expr(call), init)
+	}
+
+	// Build the result.
+	// e = iface{typeWord, data}
+	e := ir.NewBinaryExpr(base.Pos, ir.OEFACE, typeWord, data)
+	e.SetType(toType) // assign type manually, typecheck doesn't understand OEFACE.
+	e.SetTypecheck(1)
+	return e
+}
+
+// Returns the data word (the second word) used to represent n in an interface.
+// n must not be of interface type.
+// esc describes whether the result escapes.
+func dataWord(n ir.Node, init *ir.Nodes, escapes bool) ir.Node {
+	fromType := n.Type()
+
+	// If it's a pointer, it is its own representation.
+	if types.IsDirectIface(fromType) {
+		return n
+	}
+
+	// Try a bunch of cases to avoid an allocation.
 	var value ir.Node
 	switch {
 	case fromType.Size() == 0:
-		// n.Left is zero-sized. Use zerobase.
-		cheapExpr(n.X, init) // Evaluate n.Left for side-effects. See issue 19246.
+		// n is zero-sized. Use zerobase.
+		cheapExpr(n, init) // Evaluate n for side-effects. See issue 19246.
 		value = ir.NewLinksymExpr(base.Pos, ir.Syms.Zerobase, types.Types[types.TUINTPTR])
 	case fromType.IsBoolean() || (fromType.Size() == 1 && fromType.IsInteger()):
-		// n.Left is a bool/byte. Use staticuint64s[n.Left * 8] on little-endian
-		// and staticuint64s[n.Left * 8 + 7] on big-endian.
-		n.X = cheapExpr(n.X, init)
-		// byteindex widens n.Left so that the multiplication doesn't overflow.
-		index := ir.NewBinaryExpr(base.Pos, ir.OLSH, byteindex(n.X), ir.NewInt(3))
+		// n is a bool/byte. Use staticuint64s[n * 8] on little-endian
+		// and staticuint64s[n * 8 + 7] on big-endian.
+		n = cheapExpr(n, init)
+		// byteindex widens n so that the multiplication doesn't overflow.
+		index := ir.NewBinaryExpr(base.Pos, ir.OLSH, byteindex(n), ir.NewInt(3))
 		if ssagen.Arch.LinkArch.ByteOrder == binary.BigEndian {
 			index = ir.NewBinaryExpr(base.Pos, ir.OADD, index, ir.NewInt(7))
 		}
@@ -90,118 +142,71 @@ func walkConvInterface(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 		xe := ir.NewIndexExpr(base.Pos, staticuint64s, index)
 		xe.SetBounded(true)
 		value = xe
-	case n.X.Op() == ir.ONAME && n.X.(*ir.Name).Class == ir.PEXTERN && n.X.(*ir.Name).Readonly():
-		// n.Left is a readonly global; use it directly.
-		value = n.X
-	case !fromType.IsInterface() && n.Esc() == ir.EscNone && fromType.Width <= 1024:
-		// n.Left does not escape. Use a stack temporary initialized to n.Left.
+	case n.Op() == ir.ONAME && n.(*ir.Name).Class == ir.PEXTERN && n.(*ir.Name).Readonly():
+		// n is a readonly global; use it directly.
+		value = n
+	case !escapes && fromType.Width <= 1024:
+		// n does not escape. Use a stack temporary initialized to n.
 		value = typecheck.Temp(fromType)
-		init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, value, n.X)))
+		init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, value, n)))
 	}
-
 	if value != nil {
-		// Value is identical to n.Left.
-		// Construct the interface directly: {type/itab, &value}.
-		l := ir.NewBinaryExpr(base.Pos, ir.OEFACE, typeword(), typecheck.Expr(typecheck.NodAddr(value)))
-		l.SetType(toType)
-		l.SetTypecheck(n.Typecheck())
-		return l
+		// The interface data word is &value.
+		return typecheck.Expr(typecheck.NodAddr(value))
 	}
 
-	// Implement interface to empty interface conversion.
-	// tmp = i.itab
-	// if tmp != nil {
-	//    tmp = tmp.type
-	// }
-	// e = iface{tmp, i.data}
-	if toType.IsEmptyInterface() && fromType.IsInterface() && !fromType.IsEmptyInterface() {
-		// Evaluate the input interface.
-		c := typecheck.Temp(fromType)
-		init.Append(ir.NewAssignStmt(base.Pos, c, n.X))
+	// Time to do an allocation. We'll call into the runtime for that.
+	fnname, argType, needsaddr := dataWordFuncName(fromType)
+	fn := typecheck.LookupRuntime(fnname)
 
-		// Get the itab out of the interface.
-		tmp := typecheck.Temp(types.NewPtr(types.Types[types.TUINT8]))
-		init.Append(ir.NewAssignStmt(base.Pos, tmp, typecheck.Expr(ir.NewUnaryExpr(base.Pos, ir.OITAB, c))))
-
-		// Get the type out of the itab.
-		nif := ir.NewIfStmt(base.Pos, typecheck.Expr(ir.NewBinaryExpr(base.Pos, ir.ONE, tmp, typecheck.NodNil())), nil, nil)
-		nif.Body = []ir.Node{ir.NewAssignStmt(base.Pos, tmp, itabType(tmp))}
-		init.Append(nif)
-
-		// Build the result.
-		e := ir.NewBinaryExpr(base.Pos, ir.OEFACE, tmp, ifaceData(n.Pos(), c, types.NewPtr(types.Types[types.TUINT8])))
-		e.SetType(toType) // assign type manually, typecheck doesn't understand OEFACE.
-		e.SetTypecheck(1)
-		return e
-	}
-
-	fnname, argType, needsaddr := convFuncName(fromType, toType)
-
-	if !needsaddr && !fromType.IsInterface() {
-		// Use a specialized conversion routine that only returns a data pointer.
-		// ptr = convT2X(val)
-		// e = iface{typ/tab, ptr}
-		fn := typecheck.LookupRuntime(fnname)
-		types.CalcSize(fromType)
-
-		arg := n.X
+	var args []ir.Node
+	if needsaddr {
+		// Types of large or unknown size are passed by reference.
+		// Orderexpr arranged for n to be a temporary for all
+		// the conversions it could see. Comparison of an interface
+		// with a non-interface, especially in a switch on interface value
+		// with non-interface cases, is not visible to order.stmt, so we
+		// have to fall back on allocating a temp here.
+		if !ir.IsAddressable(n) {
+			n = copyExpr(n, fromType, init)
+		}
+		fn = typecheck.SubstArgTypes(fn, fromType)
+		args = []ir.Node{reflectdata.TypePtr(fromType), typecheck.NodAddr(n)}
+	} else {
+		// Use a specialized conversion routine that takes the type being
+		// converted by value, not by pointer.
+		var arg ir.Node
 		switch {
 		case fromType == argType:
 			// already in the right type, nothing to do
+			arg = n
 		case fromType.Kind() == argType.Kind(),
 			fromType.IsPtrShaped() && argType.IsPtrShaped():
 			// can directly convert (e.g. named type to underlying type, or one pointer to another)
-			arg = ir.NewConvExpr(n.Pos(), ir.OCONVNOP, argType, arg)
+			// TODO: never happens because pointers are directIface?
+			arg = ir.NewConvExpr(n.Pos(), ir.OCONVNOP, argType, n)
 		case fromType.IsInteger() && argType.IsInteger():
 			// can directly convert (e.g. int32 to uint32)
-			arg = ir.NewConvExpr(n.Pos(), ir.OCONV, argType, arg)
+			arg = ir.NewConvExpr(n.Pos(), ir.OCONV, argType, n)
 		default:
 			// unsafe cast through memory
-			arg = copyExpr(arg, arg.Type(), init)
+			arg = copyExpr(n, fromType, init)
 			var addr ir.Node = typecheck.NodAddr(arg)
 			addr = ir.NewConvExpr(n.Pos(), ir.OCONVNOP, argType.PtrTo(), addr)
 			arg = ir.NewStarExpr(n.Pos(), addr)
 			arg.SetType(argType)
 		}
-
-		call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, nil)
-		call.Args = []ir.Node{arg}
-		e := ir.NewBinaryExpr(base.Pos, ir.OEFACE, typeword(), safeExpr(walkExpr(typecheck.Expr(call), init), init))
-		e.SetType(toType)
-		e.SetTypecheck(1)
-		return e
+		args = []ir.Node{arg}
 	}
-
-	var tab ir.Node
-	if fromType.IsInterface() {
-		// convI2I
-		tab = reflectdata.TypePtr(toType)
-	} else {
-		// convT2x
-		tab = typeword()
-	}
-
-	v := n.X
-	if needsaddr {
-		// Types of large or unknown size are passed by reference.
-		// Orderexpr arranged for n.Left to be a temporary for all
-		// the conversions it could see. Comparison of an interface
-		// with a non-interface, especially in a switch on interface value
-		// with non-interface cases, is not visible to order.stmt, so we
-		// have to fall back on allocating a temp here.
-		if !ir.IsAddressable(v) {
-			v = copyExpr(v, v.Type(), init)
-		}
-		v = typecheck.NodAddr(v)
-	}
-
-	types.CalcSize(fromType)
-	fn := typecheck.LookupRuntime(fnname)
-	fn = typecheck.SubstArgTypes(fn, fromType, toType)
-	types.CalcSize(fn.Type())
 	call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, nil)
-	call.Args = []ir.Node{tab, v}
-	return walkExpr(typecheck.Expr(call), init)
+	call.Args = args
+	return safeExpr(walkExpr(typecheck.Expr(call), init), init)
+}
+
+// walkConvIData walks an OCONVIDATA node.
+func walkConvIData(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
+	n.X = walkExpr(n.X, init)
+	return dataWord(n.X, init, n.Esc() != ir.EscNone)
 }
 
 // walkBytesRunesToString walks an OBYTES2STR or ORUNES2STR node.
@@ -312,50 +317,35 @@ func walkStringToRunes(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 	return mkcall("stringtoslicerune", n.Type(), init, a, typecheck.Conv(n.X, types.Types[types.TSTRING]))
 }
 
-// convFuncName builds the runtime function name for interface conversion.
-// It also returns the argument type that the runtime function takes, and
-// whether the function expects the data by address.
-// Not all names are possible. For example, we never generate convE2E or convE2I.
-func convFuncName(from, to *types.Type) (fnname string, argType *types.Type, needsaddr bool) {
-	tkind := to.Tie()
-	switch from.Tie() {
-	case 'I':
-		if tkind == 'I' {
-			return "convI2I", types.Types[types.TINTER], false
-		}
-	case 'T':
+// dataWordFuncName returns the name of the function used to convert a value of type "from"
+// to the data word of an interface.
+// argType is the type the argument needs to be coerced to.
+// needsaddr reports whether the value should be passed (needaddr==false) or its address (needsaddr==true).
+func dataWordFuncName(from *types.Type) (fnname string, argType *types.Type, needsaddr bool) {
+	if from.IsInterface() {
+		base.Fatalf("can only handle non-interfaces")
+	}
+	switch {
+	case from.Size() == 2 && from.Align == 2:
+		return "convT16", types.Types[types.TUINT16], false
+	case from.Size() == 4 && from.Align == 4 && !from.HasPointers():
+		return "convT32", types.Types[types.TUINT32], false
+	case from.Size() == 8 && from.Align == types.Types[types.TUINT64].Align && !from.HasPointers():
+		return "convT64", types.Types[types.TUINT64], false
+	}
+	if sc := from.SoleComponent(); sc != nil {
 		switch {
-		case from.Size() == 2 && from.Align == 2:
-			return "convT16", types.Types[types.TUINT16], false
-		case from.Size() == 4 && from.Align == 4 && !from.HasPointers():
-			return "convT32", types.Types[types.TUINT32], false
-		case from.Size() == 8 && from.Align == types.Types[types.TUINT64].Align && !from.HasPointers():
-			return "convT64", types.Types[types.TUINT64], false
-		}
-		if sc := from.SoleComponent(); sc != nil {
-			switch {
-			case sc.IsString():
-				return "convTstring", types.Types[types.TSTRING], false
-			case sc.IsSlice():
-				return "convTslice", types.NewSlice(types.Types[types.TUINT8]), false // the element type doesn't matter
-			}
-		}
-
-		switch tkind {
-		case 'E':
-			if !from.HasPointers() {
-				return "convT2Enoptr", types.Types[types.TUNSAFEPTR], true
-			}
-			return "convT2E", types.Types[types.TUNSAFEPTR], true
-		case 'I':
-			if !from.HasPointers() {
-				return "convT2Inoptr", types.Types[types.TUNSAFEPTR], true
-			}
-			return "convT2I", types.Types[types.TUNSAFEPTR], true
+		case sc.IsString():
+			return "convTstring", types.Types[types.TSTRING], false
+		case sc.IsSlice():
+			return "convTslice", types.NewSlice(types.Types[types.TUINT8]), false // the element type doesn't matter
 		}
 	}
-	base.Fatalf("unknown conv func %c2%c", from.Tie(), to.Tie())
-	panic("unreachable")
+
+	if from.HasPointers() {
+		return "convT", types.Types[types.TUNSAFEPTR], true
+	}
+	return "convTnoptr", types.Types[types.TUNSAFEPTR], true
 }
 
 // rtconvfn returns the parameter and result types that will be used by a
@@ -462,7 +452,9 @@ func walkCheckPtrArithmetic(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 	// TODO(mdempsky): Make stricter. We only need to exempt
 	// reflect.Value.Pointer and reflect.Value.UnsafeAddr.
 	switch n.X.Op() {
-	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER:
+	case ir.OCALLMETH:
+		base.FatalfAt(n.X.Pos(), "OCALLMETH missed by typecheck")
+	case ir.OCALLFUNC, ir.OCALLINTER:
 		return n
 	}
 
@@ -499,7 +491,7 @@ func walkCheckPtrArithmetic(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 
 	cheap := cheapExpr(n, init)
 
-	slice := typecheck.MakeDotArgs(types.NewSlice(types.Types[types.TUNSAFEPTR]), originals)
+	slice := typecheck.MakeDotArgs(base.Pos, types.NewSlice(types.Types[types.TUNSAFEPTR]), originals)
 	slice.SetEsc(ir.EscNone)
 
 	init.Append(mkcall("checkptrArithmetic", nil, init, typecheck.ConvNop(cheap, types.Types[types.TUNSAFEPTR]), slice))
diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go
index 2fb907710bb..26e225440a7 100644
--- a/src/cmd/compile/internal/walk/expr.go
+++ b/src/cmd/compile/internal/walk/expr.go
@@ -82,7 +82,7 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		base.Fatalf("walkExpr: switch 1 unknown op %+v", n.Op())
 		panic("unreachable")
 
-	case ir.ONONAME, ir.OGETG:
+	case ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP:
 		return n
 
 	case ir.OTYPE, ir.ONAME, ir.OLITERAL, ir.ONIL, ir.OLINKSYMOFFSET:
@@ -136,6 +136,10 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		n := n.(*ir.TypeAssertExpr)
 		return walkDotType(n, init)
 
+	case ir.ODYNAMICDOTTYPE, ir.ODYNAMICDOTTYPE2:
+		n := n.(*ir.DynamicTypeAssertExpr)
+		return walkDynamicDotType(n, init)
+
 	case ir.OLEN, ir.OCAP:
 		n := n.(*ir.UnaryExpr)
 		return walkLenCap(n, init)
@@ -161,13 +165,13 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		n := n.(*ir.UnaryExpr)
 		return mkcall("gopanic", nil, init, n.X)
 
-	case ir.ORECOVER:
-		return walkRecover(n.(*ir.CallExpr), init)
+	case ir.ORECOVERFP:
+		return walkRecoverFP(n.(*ir.CallExpr), init)
 
 	case ir.OCFUNC:
 		return n
 
-	case ir.OCALLINTER, ir.OCALLFUNC, ir.OCALLMETH:
+	case ir.OCALLINTER, ir.OCALLFUNC:
 		n := n.(*ir.CallExpr)
 		return walkCall(n, init)
 
@@ -206,6 +210,10 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		n := n.(*ir.ConvExpr)
 		return walkConvInterface(n, init)
 
+	case ir.OCONVIDATA:
+		n := n.(*ir.ConvExpr)
+		return walkConvIData(n, init)
+
 	case ir.OCONV, ir.OCONVNOP:
 		n := n.(*ir.ConvExpr)
 		return walkConv(n, init)
@@ -308,8 +316,8 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 	case ir.OCLOSURE:
 		return walkClosure(n.(*ir.ClosureExpr), init)
 
-	case ir.OCALLPART:
-		return walkCallPart(n.(*ir.SelectorExpr), init)
+	case ir.OMETHVALUE:
+		return walkMethodValue(n.(*ir.SelectorExpr), init)
 	}
 
 	// No return! Each case must return (or panic),
@@ -487,9 +495,12 @@ func walkAddString(n *ir.AddStringExpr, init *ir.Nodes) ir.Node {
 	return r1
 }
 
-// walkCall walks an OCALLFUNC, OCALLINTER, or OCALLMETH node.
+// walkCall walks an OCALLFUNC or OCALLINTER node.
 func walkCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
-	if n.Op() == ir.OCALLINTER || n.Op() == ir.OCALLMETH {
+	if n.Op() == ir.OCALLMETH {
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
+	}
+	if n.Op() == ir.OCALLINTER || n.X.Op() == ir.OMETHEXPR {
 		// We expect both interface call reflect.Type.Method and concrete
 		// call reflect.(*rtype).Method.
 		usemethod(n)
@@ -549,20 +560,8 @@ func walkCall1(n *ir.CallExpr, init *ir.Nodes) {
 	}
 	n.SetWalked(true)
 
-	// If this is a method call t.M(...),
-	// rewrite into a function call T.M(t, ...).
-	// TODO(mdempsky): Do this right after type checking.
 	if n.Op() == ir.OCALLMETH {
-		withRecv := make([]ir.Node, len(n.Args)+1)
-		dot := n.X.(*ir.SelectorExpr)
-		withRecv[0] = dot.X
-		copy(withRecv[1:], n.Args)
-		n.Args = withRecv
-
-		dot = ir.NewSelectorExpr(dot.Pos(), ir.OXDOT, ir.TypeNode(dot.X.Type()), dot.Selection.Sym)
-
-		n.SetOp(ir.OCALLFUNC)
-		n.X = typecheck.Expr(dot)
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
 	}
 
 	args := n.Args
@@ -671,6 +670,13 @@ func walkDotType(n *ir.TypeAssertExpr, init *ir.Nodes) ir.Node {
 	return n
 }
 
+// walkDynamicdotType walks an ODYNAMICDOTTYPE or ODYNAMICDOTTYPE2 node.
+func walkDynamicDotType(n *ir.DynamicTypeAssertExpr, init *ir.Nodes) ir.Node {
+	n.X = walkExpr(n.X, init)
+	n.T = walkExpr(n.T, init)
+	return n
+}
+
 // walkIndex walks an OINDEX node.
 func walkIndex(n *ir.IndexExpr, init *ir.Nodes) ir.Node {
 	n.X = walkExpr(n.X, init)
@@ -931,42 +937,8 @@ func bounded(n ir.Node, max int64) bool {
 	return false
 }
 
-// usemethod checks interface method calls for uses of reflect.Type.Method.
+// usemethod checks calls for uses of reflect.Type.{Method,MethodByName}.
 func usemethod(n *ir.CallExpr) {
-	t := n.X.Type()
-
-	// Looking for either of:
-	//	Method(int) reflect.Method
-	//	MethodByName(string) (reflect.Method, bool)
-	//
-	// TODO(crawshaw): improve precision of match by working out
-	//                 how to check the method name.
-	if n := t.NumParams(); n != 1 {
-		return
-	}
-	if n := t.NumResults(); n != 1 && n != 2 {
-		return
-	}
-	p0 := t.Params().Field(0)
-	res0 := t.Results().Field(0)
-	var res1 *types.Field
-	if t.NumResults() == 2 {
-		res1 = t.Results().Field(1)
-	}
-
-	if res1 == nil {
-		if p0.Type.Kind() != types.TINT {
-			return
-		}
-	} else {
-		if !p0.Type.IsString() {
-			return
-		}
-		if !res1.Type.IsBoolean() {
-			return
-		}
-	}
-
 	// Don't mark reflect.(*rtype).Method, etc. themselves in the reflect package.
 	// Those functions may be alive via the itab, which should not cause all methods
 	// alive. We only want to mark their callers.
@@ -977,10 +949,43 @@ func usemethod(n *ir.CallExpr) {
 		}
 	}
 
-	// Note: Don't rely on res0.Type.String() since its formatting depends on multiple factors
-	//       (including global variables such as numImports - was issue #19028).
-	// Also need to check for reflect package itself (see Issue #38515).
-	if s := res0.Type.Sym(); s != nil && s.Name == "Method" && types.IsReflectPkg(s.Pkg) {
+	dot, ok := n.X.(*ir.SelectorExpr)
+	if !ok {
+		return
+	}
+
+	// Looking for either direct method calls and interface method calls of:
+	//	reflect.Type.Method       - func(int) reflect.Method
+	//	reflect.Type.MethodByName - func(string) (reflect.Method, bool)
+	var pKind types.Kind
+
+	switch dot.Sel.Name {
+	case "Method":
+		pKind = types.TINT
+	case "MethodByName":
+		pKind = types.TSTRING
+	default:
+		return
+	}
+
+	t := dot.Selection.Type
+	if t.NumParams() != 1 || t.Params().Field(0).Type.Kind() != pKind {
+		return
+	}
+	switch t.NumResults() {
+	case 1:
+		// ok
+	case 2:
+		if t.Results().Field(1).Type.Kind() != types.TBOOL {
+			return
+		}
+	default:
+		return
+	}
+
+	// Check that first result type is "reflect.Method". Note that we have to check sym name and sym package
+	// separately, as we can't check for exact string "reflect.Method" reliably (e.g., see #19028 and #38515).
+	if s := t.Results().Field(0).Type.Sym(); s != nil && s.Name == "Method" && types.IsReflectPkg(s.Pkg) {
 		ir.CurFunc.SetReflectMethod(true)
 		// The LSym is initialized at this point. We need to set the attribute on the LSym.
 		ir.CurFunc.LSym.Set(obj.AttrReflectMethod, true)
diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go
index b733d3a29f6..6e336f565cf 100644
--- a/src/cmd/compile/internal/walk/order.go
+++ b/src/cmd/compile/internal/walk/order.go
@@ -7,10 +7,8 @@ package walk
 import (
 	"fmt"
 	"go/constant"
-	"internal/buildcfg"
 
 	"cmd/compile/internal/base"
-	"cmd/compile/internal/escape"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/staticinit"
@@ -53,7 +51,7 @@ import (
 type orderState struct {
 	out  []ir.Node             // list of generated statements
 	temp []*ir.Name            // stack of temporary variables
-	free map[string][]*ir.Name // free list of unused temporaries, by type.LongString().
+	free map[string][]*ir.Name // free list of unused temporaries, by type.LinkString().
 	edit func(ir.Node) ir.Node // cached closure of o.exprNoLHS
 }
 
@@ -78,20 +76,14 @@ func (o *orderState) append(stmt ir.Node) {
 // If clear is true, newTemp emits code to zero the temporary.
 func (o *orderState) newTemp(t *types.Type, clear bool) *ir.Name {
 	var v *ir.Name
-	// Note: LongString is close to the type equality we want,
-	// but not exactly. We still need to double-check with types.Identical.
-	key := t.LongString()
-	a := o.free[key]
-	for i, n := range a {
-		if types.Identical(t, n.Type()) {
-			v = a[i]
-			a[i] = a[len(a)-1]
-			a = a[:len(a)-1]
-			o.free[key] = a
-			break
+	key := t.LinkString()
+	if a := o.free[key]; len(a) > 0 {
+		v = a[len(a)-1]
+		if !types.Identical(t, v.Type()) {
+			base.Fatalf("expected %L to have type %v", v, t)
 		}
-	}
-	if v == nil {
+		o.free[key] = a[:len(a)-1]
+	} else {
 		v = typecheck.Temp(t)
 	}
 	if clear {
@@ -372,7 +364,7 @@ func (o *orderState) markTemp() ordermarker {
 // which must have been returned by markTemp.
 func (o *orderState) popTemp(mark ordermarker) {
 	for _, n := range o.temp[mark:] {
-		key := n.Type().LongString()
+		key := n.Type().LinkString()
 		o.free[key] = append(o.free[key], n)
 	}
 	o.temp = o.temp[:mark]
@@ -514,15 +506,18 @@ func (o *orderState) init(n ir.Node) {
 }
 
 // call orders the call expression n.
-// n.Op is OCALLMETH/OCALLFUNC/OCALLINTER or a builtin like OCOPY.
+// n.Op is OCALLFUNC/OCALLINTER or a builtin like OCOPY.
 func (o *orderState) call(nn ir.Node) {
 	if len(nn.Init()) > 0 {
 		// Caller should have already called o.init(nn).
 		base.Fatalf("%v with unexpected ninit", nn.Op())
 	}
+	if nn.Op() == ir.OCALLMETH {
+		base.FatalfAt(nn.Pos(), "OCALLMETH missed by typecheck")
+	}
 
 	// Builtin functions.
-	if nn.Op() != ir.OCALLFUNC && nn.Op() != ir.OCALLMETH && nn.Op() != ir.OCALLINTER {
+	if nn.Op() != ir.OCALLFUNC && nn.Op() != ir.OCALLINTER {
 		switch n := nn.(type) {
 		default:
 			base.Fatalf("unexpected call: %+v", n)
@@ -554,39 +549,6 @@ func (o *orderState) call(nn ir.Node) {
 
 	n.X = o.expr(n.X, nil)
 	o.exprList(n.Args)
-
-	if n.Op() == ir.OCALLINTER {
-		return
-	}
-	keepAlive := func(arg ir.Node) {
-		// If the argument is really a pointer being converted to uintptr,
-		// arrange for the pointer to be kept alive until the call returns,
-		// by copying it into a temp and marking that temp
-		// still alive when we pop the temp stack.
-		if arg.Op() == ir.OCONVNOP {
-			arg := arg.(*ir.ConvExpr)
-			if arg.X.Type().IsUnsafePtr() {
-				x := o.copyExpr(arg.X)
-				arg.X = x
-				x.SetAddrtaken(true) // ensure SSA keeps the x variable
-				n.KeepAlive = append(n.KeepAlive, x)
-			}
-		}
-	}
-
-	// Check for "unsafe-uintptr" tag provided by escape analysis.
-	for i, param := range n.X.Type().Params().FieldSlice() {
-		if param.Note == escape.UnsafeUintptrNote || param.Note == escape.UintptrEscapesNote {
-			if arg := n.Args[i]; arg.Op() == ir.OSLICELIT {
-				arg := arg.(*ir.CompLitExpr)
-				for _, elt := range arg.List {
-					keepAlive(elt)
-				}
-			} else {
-				keepAlive(arg)
-			}
-		}
-	}
 }
 
 // mapAssign appends n to o.out.
@@ -693,9 +655,20 @@ func (o *orderState) stmt(n ir.Node) {
 		n := n.(*ir.AssignListStmt)
 		t := o.markTemp()
 		o.exprList(n.Lhs)
-		o.init(n.Rhs[0])
-		o.call(n.Rhs[0])
-		o.as2func(n)
+		call := n.Rhs[0]
+		o.init(call)
+		if ic, ok := call.(*ir.InlinedCallExpr); ok {
+			o.stmtList(ic.Body)
+
+			n.SetOp(ir.OAS2)
+			n.Rhs = ic.ReturnVars
+
+			o.exprList(n.Rhs)
+			o.out = append(o.out, n)
+		} else {
+			o.call(call)
+			o.as2func(n)
+		}
 		o.cleanTemp(t)
 
 	// Special: use temporary variables to hold result,
@@ -713,6 +686,10 @@ func (o *orderState) stmt(n ir.Node) {
 		case ir.ODOTTYPE2:
 			r := r.(*ir.TypeAssertExpr)
 			r.X = o.expr(r.X, nil)
+		case ir.ODYNAMICDOTTYPE2:
+			r := r.(*ir.DynamicTypeAssertExpr)
+			r.X = o.expr(r.X, nil)
+			r.T = o.expr(r.T, nil)
 		case ir.ORECV:
 			r := r.(*ir.UnaryExpr)
 			r.X = o.expr(r.X, nil)
@@ -748,14 +725,25 @@ func (o *orderState) stmt(n ir.Node) {
 		o.out = append(o.out, n)
 
 	// Special: handle call arguments.
-	case ir.OCALLFUNC, ir.OCALLINTER, ir.OCALLMETH:
+	case ir.OCALLFUNC, ir.OCALLINTER:
 		n := n.(*ir.CallExpr)
 		t := o.markTemp()
 		o.call(n)
 		o.out = append(o.out, n)
 		o.cleanTemp(t)
 
-	case ir.OCLOSE, ir.ORECV:
+	case ir.OINLCALL:
+		n := n.(*ir.InlinedCallExpr)
+		o.stmtList(n.Body)
+
+		// discard results; double-check for no side effects
+		for _, result := range n.ReturnVars {
+			if staticinit.AnySideEffects(result) {
+				base.FatalfAt(result.Pos(), "inlined call result has side effects: %v", result)
+			}
+		}
+
+	case ir.OCHECKNIL, ir.OCLOSE, ir.OPANIC, ir.ORECV:
 		n := n.(*ir.UnaryExpr)
 		t := o.markTemp()
 		n.X = o.expr(n.X, nil)
@@ -770,10 +758,10 @@ func (o *orderState) stmt(n ir.Node) {
 		o.out = append(o.out, n)
 		o.cleanTemp(t)
 
-	case ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
+	case ir.OPRINT, ir.OPRINTN, ir.ORECOVERFP:
 		n := n.(*ir.CallExpr)
 		t := o.markTemp()
-		o.exprList(n.Args)
+		o.call(n)
 		o.out = append(o.out, n)
 		o.cleanTemp(t)
 
@@ -783,16 +771,6 @@ func (o *orderState) stmt(n ir.Node) {
 		t := o.markTemp()
 		o.init(n.Call)
 		o.call(n.Call)
-		if n.Call.Op() == ir.ORECOVER {
-			// Special handling of "defer recover()". We need to evaluate the FP
-			// argument before wrapping.
-			var init ir.Nodes
-			n.Call = walkRecover(n.Call.(*ir.CallExpr), &init)
-			o.stmtList(init)
-		}
-		if buildcfg.Experiment.RegabiDefer {
-			o.wrapGoDefer(n)
-		}
 		o.out = append(o.out, n)
 		o.cleanTemp(t)
 
@@ -830,16 +808,6 @@ func (o *orderState) stmt(n ir.Node) {
 		orderBlock(&n.Else, o.free)
 		o.out = append(o.out, n)
 
-	case ir.OPANIC:
-		n := n.(*ir.UnaryExpr)
-		t := o.markTemp()
-		n.X = o.expr(n.X, nil)
-		if !n.X.Type().IsEmptyInterface() {
-			base.FatalfAt(n.Pos(), "bad argument to panic: %L", n.X)
-		}
-		o.out = append(o.out, n)
-		o.cleanTemp(t)
-
 	case ir.ORANGE:
 		// n.Right is the expression being ranged over.
 		// order it, and then make a copy if we need one.
@@ -1192,23 +1160,26 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 
 	// concrete type (not interface) argument might need an addressable
 	// temporary to pass to the runtime conversion routine.
-	case ir.OCONVIFACE:
+	case ir.OCONVIFACE, ir.OCONVIDATA:
 		n := n.(*ir.ConvExpr)
 		n.X = o.expr(n.X, nil)
 		if n.X.Type().IsInterface() {
 			return n
 		}
-		if _, _, needsaddr := convFuncName(n.X.Type(), n.Type()); needsaddr || isStaticCompositeLiteral(n.X) {
+		if _, _, needsaddr := dataWordFuncName(n.X.Type()); needsaddr || isStaticCompositeLiteral(n.X) {
 			// Need a temp if we need to pass the address to the conversion function.
 			// We also process static composite literal node here, making a named static global
-			// whose address we can put directly in an interface (see OCONVIFACE case in walk).
+			// whose address we can put directly in an interface (see OCONVIFACE/OCONVIDATA case in walk).
 			n.X = o.addrTemp(n.X)
 		}
 		return n
 
 	case ir.OCONVNOP:
 		n := n.(*ir.ConvExpr)
-		if n.Type().IsKind(types.TUNSAFEPTR) && n.X.Type().IsKind(types.TUINTPTR) && (n.X.Op() == ir.OCALLFUNC || n.X.Op() == ir.OCALLINTER || n.X.Op() == ir.OCALLMETH) {
+		if n.X.Op() == ir.OCALLMETH {
+			base.FatalfAt(n.X.Pos(), "OCALLMETH missed by typecheck")
+		}
+		if n.Type().IsKind(types.TUNSAFEPTR) && n.X.Type().IsKind(types.TUINTPTR) && (n.X.Op() == ir.OCALLFUNC || n.X.Op() == ir.OCALLINTER) {
 			call := n.X.(*ir.CallExpr)
 			// When reordering unsafe.Pointer(f()) into a separate
 			// statement, the conversion and function call must stay
@@ -1261,9 +1232,12 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		o.out = append(o.out, nif)
 		return r
 
+	case ir.OCALLMETH:
+		base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
+		panic("unreachable")
+
 	case ir.OCALLFUNC,
 		ir.OCALLINTER,
-		ir.OCALLMETH,
 		ir.OCAP,
 		ir.OCOMPLEX,
 		ir.OCOPY,
@@ -1275,7 +1249,7 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		ir.OMAKESLICECOPY,
 		ir.ONEW,
 		ir.OREAL,
-		ir.ORECOVER,
+		ir.ORECOVERFP,
 		ir.OSTR2BYTES,
 		ir.OSTR2BYTESTMP,
 		ir.OSTR2RUNES:
@@ -1293,6 +1267,11 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		}
 		return n
 
+	case ir.OINLCALL:
+		n := n.(*ir.InlinedCallExpr)
+		o.stmtList(n.Body)
+		return n.SingleResult()
+
 	case ir.OAPPEND:
 		// Check for append(x, make([]T, y)...) .
 		n := n.(*ir.CallExpr)
@@ -1327,11 +1306,11 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		}
 		return n
 
-	case ir.OCALLPART:
+	case ir.OMETHVALUE:
 		n := n.(*ir.SelectorExpr)
 		n.X = o.expr(n.X, nil)
 		if n.Transient() {
-			t := typecheck.PartialCallType(n)
+			t := typecheck.MethodValueType(n)
 			n.Prealloc = o.newTemp(t, false)
 		}
 		return n
@@ -1498,313 +1477,6 @@ func (o *orderState) as2ok(n *ir.AssignListStmt) {
 	o.stmt(typecheck.Stmt(as))
 }
 
-var wrapGoDefer_prgen int
-
-// wrapGoDefer wraps the target of a "go" or "defer" statement with a
-// new "function with no arguments" closure. Specifically, it converts
-//
-//   defer f(x, y)
-//
-// to
-//
-//   x1, y1 := x, y
-//   defer func() { f(x1, y1) }()
-//
-// This is primarily to enable a quicker bringup of defers under the
-// new register ABI; by doing this conversion, we can simplify the
-// code in the runtime that invokes defers on the panic path.
-func (o *orderState) wrapGoDefer(n *ir.GoDeferStmt) {
-	call := n.Call
-
-	var callX ir.Node        // thing being called
-	var callArgs []ir.Node   // call arguments
-	var keepAlive []*ir.Name // KeepAlive list from call, if present
-
-	// A helper to recreate the call within the closure.
-	var mkNewCall func(pos src.XPos, op ir.Op, fun ir.Node, args []ir.Node) ir.Node
-
-	// Defer calls come in many shapes and sizes; not all of them
-	// are ir.CallExpr's. Examine the type to see what we're dealing with.
-	switch x := call.(type) {
-	case *ir.CallExpr:
-		callX = x.X
-		callArgs = x.Args
-		keepAlive = x.KeepAlive
-		mkNewCall = func(pos src.XPos, op ir.Op, fun ir.Node, args []ir.Node) ir.Node {
-			newcall := ir.NewCallExpr(pos, op, fun, args)
-			newcall.IsDDD = x.IsDDD
-			return ir.Node(newcall)
-		}
-	case *ir.UnaryExpr: // ex: OCLOSE
-		callArgs = []ir.Node{x.X}
-		mkNewCall = func(pos src.XPos, op ir.Op, fun ir.Node, args []ir.Node) ir.Node {
-			if len(args) != 1 {
-				panic("internal error, expecting single arg")
-			}
-			return ir.Node(ir.NewUnaryExpr(pos, op, args[0]))
-		}
-	case *ir.BinaryExpr: // ex: OCOPY
-		callArgs = []ir.Node{x.X, x.Y}
-		mkNewCall = func(pos src.XPos, op ir.Op, fun ir.Node, args []ir.Node) ir.Node {
-			if len(args) != 2 {
-				panic("internal error, expecting two args")
-			}
-			return ir.Node(ir.NewBinaryExpr(pos, op, args[0], args[1]))
-		}
-	default:
-		panic("unhandled op")
-	}
-
-	// No need to wrap if called func has no args, no receiver, and no results.
-	// However in the case of "defer func() { ... }()" we need to
-	// protect against the possibility of directClosureCall rewriting
-	// things so that the call does have arguments.
-	//
-	// Do wrap method calls (OCALLMETH, OCALLINTER), because it has
-	// a receiver.
-	//
-	// Also do wrap builtin functions, because they may be expanded to
-	// calls with arguments (e.g. ORECOVER).
-	//
-	// TODO: maybe not wrap if the called function has no arguments and
-	// only in-register results?
-	if len(callArgs) == 0 && call.Op() == ir.OCALLFUNC && callX.Type().NumResults() == 0 {
-		if c, ok := call.(*ir.CallExpr); ok && callX != nil && callX.Op() == ir.OCLOSURE {
-			cloFunc := callX.(*ir.ClosureExpr).Func
-			cloFunc.SetClosureCalled(false)
-			c.PreserveClosure = true
-		}
-		return
-	}
-
-	if c, ok := call.(*ir.CallExpr); ok {
-		// To simplify things, turn f(a, b, []T{c, d, e}...) back
-		// into f(a, b, c, d, e) -- when the final call is run through the
-		// type checker below, it will rebuild the proper slice literal.
-		undoVariadic(c)
-		callX = c.X
-		callArgs = c.Args
-	}
-
-	// This is set to true if the closure we're generating escapes
-	// (needs heap allocation).
-	cloEscapes := func() bool {
-		if n.Op() == ir.OGO {
-			// For "go", assume that all closures escape.
-			return true
-		}
-		// For defer, just use whatever result escape analysis
-		// has determined for the defer.
-		return n.Esc() != ir.EscNever
-	}()
-
-	// A helper for making a copy of an argument. Note that it is
-	// not safe to use o.copyExpr(arg) if we're putting a
-	// reference to the temp into the closure (as opposed to
-	// copying it in by value), since in the by-reference case we
-	// need a temporary whose lifetime extends to the end of the
-	// function (as opposed to being local to the current block or
-	// statement being ordered).
-	mkArgCopy := func(arg ir.Node) *ir.Name {
-		t := arg.Type()
-		byval := t.Size() <= 128 || cloEscapes
-		var argCopy *ir.Name
-		if byval {
-			argCopy = o.copyExpr(arg)
-		} else {
-			argCopy = typecheck.Temp(t)
-			o.append(ir.NewAssignStmt(base.Pos, argCopy, arg))
-		}
-		// The value of 128 below is meant to be consistent with code
-		// in escape analysis that picks byval/byaddr based on size.
-		argCopy.SetByval(byval)
-		return argCopy
-	}
-
-	// getUnsafeArg looks for an unsafe.Pointer arg that has been
-	// previously captured into the call's keepalive list, returning
-	// the name node for it if found.
-	getUnsafeArg := func(arg ir.Node) *ir.Name {
-		// Look for uintptr(unsafe.Pointer(name))
-		if arg.Op() != ir.OCONVNOP {
-			return nil
-		}
-		if !arg.Type().IsUintptr() {
-			return nil
-		}
-		if !arg.(*ir.ConvExpr).X.Type().IsUnsafePtr() {
-			return nil
-		}
-		arg = arg.(*ir.ConvExpr).X
-		argname, ok := arg.(*ir.Name)
-		if !ok {
-			return nil
-		}
-		for i := range keepAlive {
-			if argname == keepAlive[i] {
-				return argname
-			}
-		}
-		return nil
-	}
-
-	// Copy the arguments to the function into temps.
-	//
-	// For calls with uintptr(unsafe.Pointer(...)) args that are being
-	// kept alive (see code in (*orderState).call that does this), use
-	// the existing arg copy instead of creating a new copy.
-	unsafeArgs := make([]*ir.Name, len(callArgs))
-	origArgs := callArgs
-	var newNames []*ir.Name
-	for i := range callArgs {
-		arg := callArgs[i]
-		var argname *ir.Name
-		unsafeArgName := getUnsafeArg(arg)
-		if unsafeArgName != nil {
-			// arg has been copied already, use keepalive copy
-			argname = unsafeArgName
-			unsafeArgs[i] = unsafeArgName
-		} else {
-			argname = mkArgCopy(arg)
-		}
-		newNames = append(newNames, argname)
-	}
-
-	// Deal with cases where the function expression (what we're
-	// calling) is not a simple function symbol.
-	var fnExpr *ir.Name
-	var methSelectorExpr *ir.SelectorExpr
-	if callX != nil {
-		switch {
-		case callX.Op() == ir.ODOTMETH || callX.Op() == ir.ODOTINTER:
-			// Handle defer of a method call, e.g. "defer v.MyMethod(x, y)"
-			n := callX.(*ir.SelectorExpr)
-			n.X = mkArgCopy(n.X)
-			methSelectorExpr = n
-			if callX.Op() == ir.ODOTINTER {
-				// Currently for "defer i.M()" if i is nil it panics at the
-				// point of defer statement, not when deferred function is called.
-				// (I think there is an issue discussing what is the intended
-				// behavior but I cannot find it.)
-				// We need to do the nil check outside of the wrapper.
-				tab := typecheck.Expr(ir.NewUnaryExpr(base.Pos, ir.OITAB, n.X))
-				c := ir.NewUnaryExpr(n.Pos(), ir.OCHECKNIL, tab)
-				c.SetTypecheck(1)
-				o.append(c)
-			}
-		case !(callX.Op() == ir.ONAME && callX.(*ir.Name).Class == ir.PFUNC):
-			// Deal with "defer returnsafunc()(x, y)" (for
-			// example) by copying the callee expression.
-			fnExpr = mkArgCopy(callX)
-			if callX.Op() == ir.OCLOSURE {
-				// For "defer func(...)", in addition to copying the
-				// closure into a temp, mark it as no longer directly
-				// called.
-				callX.(*ir.ClosureExpr).Func.SetClosureCalled(false)
-			}
-		}
-	}
-
-	// Create a new no-argument function that we'll hand off to defer.
-	var noFuncArgs []*ir.Field
-	noargst := ir.NewFuncType(base.Pos, nil, noFuncArgs, nil)
-	wrapGoDefer_prgen++
-	outerfn := ir.CurFunc
-	wrapname := fmt.Sprintf("%v·dwrap·%d", outerfn, wrapGoDefer_prgen)
-	sym := types.LocalPkg.Lookup(wrapname)
-	fn := typecheck.DeclFunc(sym, noargst)
-	fn.SetIsHiddenClosure(true)
-	fn.SetWrapper(true)
-
-	// helper for capturing reference to a var declared in an outer scope.
-	capName := func(pos src.XPos, fn *ir.Func, n *ir.Name) *ir.Name {
-		t := n.Type()
-		cv := ir.CaptureName(pos, fn, n)
-		cv.SetType(t)
-		return typecheck.Expr(cv).(*ir.Name)
-	}
-
-	// Call args (x1, y1) need to be captured as part of the newly
-	// created closure.
-	newCallArgs := []ir.Node{}
-	for i := range newNames {
-		var arg ir.Node
-		arg = capName(callArgs[i].Pos(), fn, newNames[i])
-		if unsafeArgs[i] != nil {
-			arg = ir.NewConvExpr(arg.Pos(), origArgs[i].Op(), origArgs[i].Type(), arg)
-		}
-		newCallArgs = append(newCallArgs, arg)
-	}
-	// Also capture the function or method expression (if needed) into
-	// the closure.
-	if fnExpr != nil {
-		callX = capName(callX.Pos(), fn, fnExpr)
-	}
-	if methSelectorExpr != nil {
-		methSelectorExpr.X = capName(callX.Pos(), fn, methSelectorExpr.X.(*ir.Name))
-	}
-	ir.FinishCaptureNames(n.Pos(), outerfn, fn)
-
-	// This flags a builtin as opposed to a regular call.
-	irregular := (call.Op() != ir.OCALLFUNC &&
-		call.Op() != ir.OCALLMETH &&
-		call.Op() != ir.OCALLINTER)
-
-	// Construct new function body:  f(x1, y1)
-	op := ir.OCALL
-	if irregular {
-		op = call.Op()
-	}
-	newcall := mkNewCall(call.Pos(), op, callX, newCallArgs)
-
-	// Type-check the result.
-	if !irregular {
-		typecheck.Call(newcall.(*ir.CallExpr))
-	} else {
-		typecheck.Stmt(newcall)
-	}
-
-	// Finalize body, register function on the main decls list.
-	fn.Body = []ir.Node{newcall}
-	typecheck.FinishFuncBody()
-	typecheck.Func(fn)
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
-
-	// Create closure expr
-	clo := ir.NewClosureExpr(n.Pos(), fn)
-	fn.OClosure = clo
-	clo.SetType(fn.Type())
-
-	// Set escape properties for closure.
-	if n.Op() == ir.OGO {
-		// For "go", assume that the closure is going to escape
-		// (with an exception for the runtime, which doesn't
-		// permit heap-allocated closures).
-		if base.Ctxt.Pkgpath != "runtime" {
-			clo.SetEsc(ir.EscHeap)
-		}
-	} else {
-		// For defer, just use whatever result escape analysis
-		// has determined for the defer.
-		if n.Esc() == ir.EscNever {
-			clo.SetTransient(true)
-			clo.SetEsc(ir.EscNone)
-		}
-	}
-
-	// Create new top level call to closure over argless function.
-	topcall := ir.NewCallExpr(n.Pos(), ir.OCALL, clo, []ir.Node{})
-	typecheck.Call(topcall)
-
-	// Tag the call to insure that directClosureCall doesn't undo our work.
-	topcall.PreserveClosure = true
-
-	fn.SetClosureCalled(false)
-
-	// Finally, point the defer statement at the newly generated call.
-	n.Call = topcall
-}
-
 // isFuncPCIntrinsic returns whether n is a direct call of internal/abi.FuncPCABIxxx functions.
 func isFuncPCIntrinsic(n *ir.CallExpr) bool {
 	if n.Op() != ir.OCALLFUNC || n.X.Op() != ir.ONAME {
diff --git a/src/cmd/compile/internal/walk/stmt.go b/src/cmd/compile/internal/walk/stmt.go
index 0bf76680c46..4581bca3dfe 100644
--- a/src/cmd/compile/internal/walk/stmt.go
+++ b/src/cmd/compile/internal/walk/stmt.go
@@ -7,7 +7,6 @@ package walk
 import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
-	"cmd/compile/internal/typecheck"
 )
 
 // The result of walkStmt MUST be assigned back to n, e.g.
@@ -41,7 +40,6 @@ func walkStmt(n ir.Node) ir.Node {
 		ir.OAS2MAPR,
 		ir.OCLOSE,
 		ir.OCOPY,
-		ir.OCALLMETH,
 		ir.OCALLINTER,
 		ir.OCALL,
 		ir.OCALLFUNC,
@@ -50,7 +48,7 @@ func walkStmt(n ir.Node) ir.Node {
 		ir.OPRINT,
 		ir.OPRINTN,
 		ir.OPANIC,
-		ir.ORECOVER,
+		ir.ORECOVERFP,
 		ir.OGETG:
 		if n.Typecheck() == 0 {
 			base.Fatalf("missing typecheck: %+v", n)
@@ -187,33 +185,28 @@ func walkFor(n *ir.ForStmt) ir.Node {
 	return n
 }
 
+// validGoDeferCall reports whether call is a valid call to appear in
+// a go or defer statement; that is, whether it's a regular function
+// call without arguments or results.
+func validGoDeferCall(call ir.Node) bool {
+	if call, ok := call.(*ir.CallExpr); ok && call.Op() == ir.OCALLFUNC && len(call.KeepAlive) == 0 {
+		sig := call.X.Type()
+		return sig.NumParams()+sig.NumResults() == 0
+	}
+	return false
+}
+
 // walkGoDefer walks an OGO or ODEFER node.
 func walkGoDefer(n *ir.GoDeferStmt) ir.Node {
-	var init ir.Nodes
-	switch call := n.Call; call.Op() {
-	case ir.OPRINT, ir.OPRINTN:
-		call := call.(*ir.CallExpr)
-		n.Call = wrapCall(call, &init)
-
-	case ir.ODELETE:
-		call := call.(*ir.CallExpr)
-		n.Call = wrapCall(call, &init)
-
-	case ir.OCOPY:
-		call := call.(*ir.BinaryExpr)
-		n.Call = walkCopy(call, &init, true)
-
-	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER:
-		call := call.(*ir.CallExpr)
-		if len(call.KeepAlive) > 0 {
-			n.Call = wrapCall(call, &init)
-		} else {
-			n.Call = walkExpr(call, &init)
-		}
-
-	default:
-		n.Call = walkExpr(call, &init)
+	if !validGoDeferCall(n.Call) {
+		base.FatalfAt(n.Pos(), "invalid %v call: %v", n.Op(), n.Call)
 	}
+
+	var init ir.Nodes
+
+	call := n.Call.(*ir.CallExpr)
+	call.X = walkExpr(call.X, &init)
+
 	if len(init) > 0 {
 		init.Append(n)
 		return ir.NewBlockStmt(n.Pos(), init)
@@ -228,110 +221,3 @@ func walkIf(n *ir.IfStmt) ir.Node {
 	walkStmtList(n.Else)
 	return n
 }
-
-// Rewrite
-//	go builtin(x, y, z)
-// into
-//	go func(a1, a2, a3) {
-//		builtin(a1, a2, a3)
-//	}(x, y, z)
-// for print, println, and delete.
-//
-// Rewrite
-//	go f(x, y, uintptr(unsafe.Pointer(z)))
-// into
-//	go func(a1, a2, a3) {
-//		f(a1, a2, uintptr(a3))
-//	}(x, y, unsafe.Pointer(z))
-// for function contains unsafe-uintptr arguments.
-
-var wrapCall_prgen int
-
-// The result of wrapCall MUST be assigned back to n, e.g.
-// 	n.Left = wrapCall(n.Left, init)
-func wrapCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
-	if len(n.Init()) != 0 {
-		walkStmtList(n.Init())
-		init.Append(ir.TakeInit(n)...)
-	}
-
-	isBuiltinCall := n.Op() != ir.OCALLFUNC && n.Op() != ir.OCALLMETH && n.Op() != ir.OCALLINTER
-
-	// Turn f(a, b, []T{c, d, e}...) back into f(a, b, c, d, e).
-	if !isBuiltinCall && n.IsDDD {
-		undoVariadic(n)
-	}
-
-	wrapArgs := n.Args
-	// If there's a receiver argument, it needs to be passed through the wrapper too.
-	if n.Op() == ir.OCALLMETH || n.Op() == ir.OCALLINTER {
-		recv := n.X.(*ir.SelectorExpr).X
-		wrapArgs = append([]ir.Node{recv}, wrapArgs...)
-	}
-
-	// origArgs keeps track of what argument is uintptr-unsafe/unsafe-uintptr conversion.
-	origArgs := make([]ir.Node, len(wrapArgs))
-	var funcArgs []*ir.Field
-	for i, arg := range wrapArgs {
-		s := typecheck.LookupNum("a", i)
-		if !isBuiltinCall && arg.Op() == ir.OCONVNOP && arg.Type().IsUintptr() && arg.(*ir.ConvExpr).X.Type().IsUnsafePtr() {
-			origArgs[i] = arg
-			arg = arg.(*ir.ConvExpr).X
-			wrapArgs[i] = arg
-		}
-		funcArgs = append(funcArgs, ir.NewField(base.Pos, s, nil, arg.Type()))
-	}
-	t := ir.NewFuncType(base.Pos, nil, funcArgs, nil)
-
-	wrapCall_prgen++
-	sym := typecheck.LookupNum("wrap·", wrapCall_prgen)
-	fn := typecheck.DeclFunc(sym, t)
-
-	args := ir.ParamNames(t.Type())
-	for i, origArg := range origArgs {
-		if origArg == nil {
-			continue
-		}
-		args[i] = ir.NewConvExpr(base.Pos, origArg.Op(), origArg.Type(), args[i])
-	}
-	if n.Op() == ir.OCALLMETH || n.Op() == ir.OCALLINTER {
-		// Move wrapped receiver argument back to its appropriate place.
-		recv := typecheck.Expr(args[0])
-		n.X.(*ir.SelectorExpr).X = recv
-		args = args[1:]
-	}
-	call := ir.NewCallExpr(base.Pos, n.Op(), n.X, args)
-	if !isBuiltinCall {
-		call.SetOp(ir.OCALL)
-		call.IsDDD = n.IsDDD
-	}
-	fn.Body = []ir.Node{call}
-
-	typecheck.FinishFuncBody()
-
-	typecheck.Func(fn)
-	typecheck.Stmts(fn.Body)
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
-
-	call = ir.NewCallExpr(base.Pos, ir.OCALL, fn.Nname, wrapArgs)
-	return walkExpr(typecheck.Stmt(call), init)
-}
-
-// undoVariadic turns a call to a variadic function of the form
-//
-//      f(a, b, []T{c, d, e}...)
-//
-// back into
-//
-//      f(a, b, c, d, e)
-//
-func undoVariadic(call *ir.CallExpr) {
-	if call.IsDDD {
-		last := len(call.Args) - 1
-		if va := call.Args[last]; va.Op() == ir.OSLICELIT {
-			va := va.(*ir.CompLitExpr)
-			call.Args = append(call.Args[:last], va.List...)
-			call.IsDDD = false
-		}
-	}
-}
diff --git a/src/cmd/compile/internal/walk/switch.go b/src/cmd/compile/internal/walk/switch.go
index 162de018f63..3705c5b1926 100644
--- a/src/cmd/compile/internal/walk/switch.go
+++ b/src/cmd/compile/internal/walk/switch.go
@@ -360,10 +360,10 @@ func walkSwitchType(sw *ir.SwitchStmt) {
 			}
 
 			if singleType != nil && singleType.IsInterface() {
-				s.Add(ncase.Pos(), n1.Type(), caseVar, jmp)
+				s.Add(ncase.Pos(), n1, caseVar, jmp)
 				caseVarInitialized = true
 			} else {
-				s.Add(ncase.Pos(), n1.Type(), nil, jmp)
+				s.Add(ncase.Pos(), n1, nil, jmp)
 			}
 		}
 
@@ -377,6 +377,17 @@ func walkSwitchType(sw *ir.SwitchStmt) {
 				}
 				val = ifaceData(ncase.Pos(), s.facename, singleType)
 			}
+			if len(ncase.List) == 1 && ncase.List[0].Op() == ir.ODYNAMICTYPE {
+				dt := ncase.List[0].(*ir.DynamicType)
+				x := ir.NewDynamicTypeAssertExpr(ncase.Pos(), ir.ODYNAMICDOTTYPE, val, dt.X)
+				if dt.ITab != nil {
+					// TODO: make ITab a separate field in DynamicTypeAssertExpr?
+					x.T = dt.ITab
+				}
+				x.SetType(caseVar.Type())
+				x.SetTypecheck(1)
+				val = x
+			}
 			l := []ir.Node{
 				ir.NewDecl(ncase.Pos(), ir.ODCL, caseVar),
 				ir.NewAssignStmt(ncase.Pos(), caseVar, val),
@@ -446,7 +457,8 @@ type typeClause struct {
 	body ir.Nodes
 }
 
-func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar *ir.Name, jmp ir.Node) {
+func (s *typeSwitch) Add(pos src.XPos, n1 ir.Node, caseVar *ir.Name, jmp ir.Node) {
+	typ := n1.Type()
 	var body ir.Nodes
 	if caseVar != nil {
 		l := []ir.Node{
@@ -462,9 +474,25 @@ func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar *ir.Name, jmp ir
 	// cv, ok = iface.(type)
 	as := ir.NewAssignListStmt(pos, ir.OAS2, nil, nil)
 	as.Lhs = []ir.Node{caseVar, s.okname} // cv, ok =
-	dot := ir.NewTypeAssertExpr(pos, s.facename, nil)
-	dot.SetType(typ) // iface.(type)
-	as.Rhs = []ir.Node{dot}
+	switch n1.Op() {
+	case ir.OTYPE:
+		// Static type assertion (non-generic)
+		dot := ir.NewTypeAssertExpr(pos, s.facename, nil)
+		dot.SetType(typ) // iface.(type)
+		as.Rhs = []ir.Node{dot}
+	case ir.ODYNAMICTYPE:
+		// Dynamic type assertion (generic)
+		dt := n1.(*ir.DynamicType)
+		dot := ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, s.facename, dt.X)
+		if dt.ITab != nil {
+			dot.T = dt.ITab
+		}
+		dot.SetType(typ)
+		dot.SetTypecheck(1)
+		as.Rhs = []ir.Node{dot}
+	default:
+		base.Fatalf("unhandled type case %s", n1.Op())
+	}
 	appendWalkStmt(&body, as)
 
 	// if ok { goto label }
@@ -473,9 +501,10 @@ func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar *ir.Name, jmp ir
 	nif.Body = []ir.Node{jmp}
 	body.Append(nif)
 
-	if !typ.IsInterface() {
+	if n1.Op() == ir.OTYPE && !typ.IsInterface() {
+		// Defer static, noninterface cases so they can be binary searched by hash.
 		s.clauses = append(s.clauses, typeClause{
-			hash: types.TypeHash(typ),
+			hash: types.TypeHash(n1.Type()),
 			body: body,
 		})
 		return
diff --git a/src/cmd/compile/internal/walk/walk.go b/src/cmd/compile/internal/walk/walk.go
index fe2c62cd4f8..6551fe7a645 100644
--- a/src/cmd/compile/internal/walk/walk.go
+++ b/src/cmd/compile/internal/walk/walk.go
@@ -113,8 +113,7 @@ func vmkcall(fn ir.Node, t *types.Type, init *ir.Nodes, va []ir.Node) *ir.CallEx
 		base.Fatalf("vmkcall %v needs %v args got %v", fn, n, len(va))
 	}
 
-	call := ir.NewCallExpr(base.Pos, ir.OCALL, fn, va)
-	typecheck.Call(call)
+	call := typecheck.Call(base.Pos, fn, va, false).(*ir.CallExpr)
 	call.SetType(t)
 	return walkExpr(call, init).(*ir.CallExpr)
 }
@@ -308,12 +307,12 @@ func mayCall(n ir.Node) bool {
 		default:
 			base.FatalfAt(n.Pos(), "mayCall %+v", n)
 
-		case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER,
+		case ir.OCALLFUNC, ir.OCALLINTER,
 			ir.OUNSAFEADD, ir.OUNSAFESLICE:
 			return true
 
 		case ir.OINDEX, ir.OSLICE, ir.OSLICEARR, ir.OSLICE3, ir.OSLICE3ARR, ir.OSLICESTR,
-			ir.ODEREF, ir.ODOTPTR, ir.ODOTTYPE, ir.ODIV, ir.OMOD:
+			ir.ODEREF, ir.ODOTPTR, ir.ODOTTYPE, ir.ODIV, ir.OMOD, ir.OSLICE2ARRPTR:
 			// These ops might panic, make sure they are done
 			// before we start marshaling args for a call. See issue 16760.
 			return true
@@ -343,7 +342,7 @@ func mayCall(n ir.Node) bool {
 			ir.OCAP, ir.OIMAG, ir.OLEN, ir.OREAL,
 			ir.OCONVNOP, ir.ODOT,
 			ir.OCFUNC, ir.OIDATA, ir.OITAB, ir.OSPTR,
-			ir.OBYTES2STRTMP, ir.OGETG, ir.OSLICEHEADER:
+			ir.OBYTES2STRTMP, ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP, ir.OSLICEHEADER:
 			// ok: operations that don't require function calls.
 			// Expand as needed.
 		}
diff --git a/src/cmd/compile/internal/wasm/ssa.go b/src/cmd/compile/internal/wasm/ssa.go
index 31b09016eb9..0b2ca3fdbb8 100644
--- a/src/cmd/compile/internal/wasm/ssa.go
+++ b/src/cmd/compile/internal/wasm/ssa.go
@@ -24,7 +24,6 @@ func Init(arch *ssagen.ArchInfo) {
 
 	arch.ZeroRange = zeroRange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue
@@ -126,7 +125,11 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 	case ssa.OpWasmLoweredStaticCall, ssa.OpWasmLoweredClosureCall, ssa.OpWasmLoweredInterCall:
 		s.PrepareCall(v)
 		if call, ok := v.Aux.(*ssa.AuxCall); ok && call.Fn == ir.Syms.Deferreturn {
-			// add a resume point before call to deferreturn so it can be called again via jmpdefer
+			// The runtime needs to inject jumps to
+			// deferreturn calls using the address in
+			// _func.deferreturn. Hence, the call to
+			// deferreturn must itself be a resumption
+			// point so it gets a target PC.
 			s.Prog(wasm.ARESUMEPOINT)
 		}
 		if v.Op == ssa.OpWasmLoweredClosureCall {
diff --git a/src/cmd/compile/internal/x86/galign.go b/src/cmd/compile/internal/x86/galign.go
index 00a20e429f1..5565bd32c76 100644
--- a/src/cmd/compile/internal/x86/galign.go
+++ b/src/cmd/compile/internal/x86/galign.go
@@ -34,7 +34,6 @@ func Init(arch *ssagen.ArchInfo) {
 
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop
-	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 }
diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index 00e23ef179e..bec17696f30 100644
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -1263,14 +1263,19 @@ func cmdbootstrap() {
 	timelog("start", "dist bootstrap")
 	defer timelog("end", "dist bootstrap")
 
-	var noBanner bool
+	var noBanner, noClean bool
 	var debug bool
 	flag.BoolVar(&rebuildall, "a", rebuildall, "rebuild all")
 	flag.BoolVar(&debug, "d", debug, "enable debugging of bootstrap process")
 	flag.BoolVar(&noBanner, "no-banner", noBanner, "do not print banner")
+	flag.BoolVar(&noClean, "no-clean", noClean, "print deprecation warning")
 
 	xflagparse(0)
 
+	if noClean {
+		xprintf("warning: --no-clean is deprecated and has no effect; use 'go install std cmd' instead\n")
+	}
+
 	// Set GOPATH to an internal directory. We shouldn't actually
 	// need to store files here, since the toolchain won't
 	// depend on modules outside of vendor directories, but if
@@ -1607,6 +1612,18 @@ var incomplete = map[string]bool{
 	"linux/sparc64": true,
 }
 
+// List of platforms which are first class ports. See golang.org/issue/38874.
+var firstClass = map[string]bool{
+	"darwin/amd64":  true,
+	"darwin/arm64":  true,
+	"linux/386":     true,
+	"linux/amd64":   true,
+	"linux/arm":     true,
+	"linux/arm64":   true,
+	"windows/386":   true,
+	"windows/amd64": true,
+}
+
 func needCC() bool {
 	switch os.Getenv("CGO_ENABLED") {
 	case "1":
@@ -1743,6 +1760,7 @@ func cmdlist() {
 		GOOS         string
 		GOARCH       string
 		CgoSupported bool
+		FirstClass   bool
 	}
 	var results []jsonResult
 	for _, p := range plats {
@@ -1750,7 +1768,8 @@ func cmdlist() {
 		results = append(results, jsonResult{
 			GOOS:         fields[0],
 			GOARCH:       fields[1],
-			CgoSupported: cgoEnabled[p]})
+			CgoSupported: cgoEnabled[p],
+			FirstClass:   firstClass[p]})
 	}
 	out, err := json.MarshalIndent(results, "", "\t")
 	if err != nil {
diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index 50bf80ba596..a104b5c8f31 100644
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -491,19 +491,6 @@ func (t *tester) registerTests() {
 		})
 	}
 
-	// Test go/... cmd/gofmt with type parameters enabled.
-	if !t.compileOnly {
-		t.tests = append(t.tests, distTest{
-			name:    "tyepparams",
-			heading: "go/... and cmd/gofmt tests with tag typeparams",
-			fn: func(dt *distTest) error {
-				t.addCmd(dt, "src", t.goTest(), t.timeout(300), "-tags=typeparams", "go/...")
-				t.addCmd(dt, "src", t.goTest(), t.timeout(300), "-tags=typeparams", "cmd/gofmt")
-				return nil
-			},
-		})
-	}
-
 	if t.iOS() && !t.compileOnly {
 		t.tests = append(t.tests, distTest{
 			name:    "x509omitbundledroots",
@@ -722,14 +709,29 @@ func (t *tester) registerTests() {
 				},
 			})
 			if t.hasCxx() {
-				t.tests = append(t.tests, distTest{
-					name:    "swig_callback",
-					heading: "../misc/swig/callback",
-					fn: func(dt *distTest) error {
-						t.addCmd(dt, "misc/swig/callback", t.goTest())
-						return nil
+				t.tests = append(t.tests,
+					distTest{
+						name:    "swig_callback",
+						heading: "../misc/swig/callback",
+						fn: func(dt *distTest) error {
+							t.addCmd(dt, "misc/swig/callback", t.goTest())
+							return nil
+						},
 					},
-				})
+					distTest{
+						name:    "swig_callback_lto",
+						heading: "../misc/swig/callback",
+						fn: func(dt *distTest) error {
+							cmd := t.addCmd(dt, "misc/swig/callback", t.goTest())
+							cmd.Env = append(os.Environ(),
+								"CGO_CFLAGS=-flto -Wno-lto-type-mismatch -Wno-unknown-warning-option",
+								"CGO_CXXFLAGS=-flto -Wno-lto-type-mismatch -Wno-unknown-warning-option",
+								"CGO_LDFLAGS=-flto -Wno-lto-type-mismatch -Wno-unknown-warning-option",
+							)
+							return nil
+						},
+					},
+				)
 			}
 		}
 	}
@@ -766,7 +768,7 @@ func (t *tester) registerTests() {
 			t.registerTest("testasan", "../misc/cgo/testasan", "go", "run", ".")
 		}
 		if goos == "linux" && goarch != "ppc64le" {
-			// because syscall.SysProcAttri struct used in misc/cgo/testsanitizers is only built on linux.
+			// because syscall.SysProcAttr struct used in misc/cgo/testsanitizers is only built on linux.
 			// Some inconsistent failures happen on ppc64le so disable for now.
 			t.registerHostTest("testsanitizers", "../misc/cgo/testsanitizers", "misc/cgo/testsanitizers", ".")
 		}
@@ -1042,7 +1044,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 			"darwin-amd64", "darwin-arm64",
 			"freebsd-amd64",
 			"android-arm", "android-arm64", "android-386",
-			"windows-amd64", "windows-386":
+			"windows-amd64", "windows-386", "windows-arm64":
 			return true
 		}
 		return false
diff --git a/src/cmd/dist/vfp_arm.s b/src/cmd/dist/vfp_arm.s
index d571f8b82a2..525ee9b3661 100644
--- a/src/cmd/dist/vfp_arm.s
+++ b/src/cmd/dist/vfp_arm.s
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build gc,arm
+//go:build gc
+// +build gc
 
 #include "textflag.h"
 
diff --git a/src/cmd/dist/vfp_default.s b/src/cmd/dist/vfp_default.s
index 84829beeff3..0c1e16b0aa0 100644
--- a/src/cmd/dist/vfp_default.s
+++ b/src/cmd/dist/vfp_default.s
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !arm,gc
+//go:build gc && !arm
+// +build gc,!arm
 
 #include "textflag.h"
 
diff --git a/src/cmd/go.mod b/src/cmd/go.mod
index a15cbe070ad..ccfff098857 100644
--- a/src/cmd/go.mod
+++ b/src/cmd/go.mod
@@ -1,15 +1,15 @@
 module cmd
 
-go 1.17
+go 1.18
 
 require (
-	github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5
+	github.com/google/pprof v0.0.0-20210506205249-923b5ab0fc1a
 	github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639 // indirect
 	golang.org/x/arch v0.0.0-20210502124803-cbf565b21d1e
 	golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e // indirect
-	golang.org/x/mod v0.4.3-0.20210504181020-67f1c1edc27a
-	golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6 // indirect
+	golang.org/x/mod v0.4.3-0.20210608190319-0f08993efd8a
+	golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744 // indirect
 	golang.org/x/term v0.0.0-20210503060354-a79de5458b56
-	golang.org/x/tools v0.1.1-0.20210505014545-7cab0ef2e9a5
+	golang.org/x/tools v0.1.6-0.20210809225032-337cebd2c151
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 )
diff --git a/src/cmd/go.sum b/src/cmd/go.sum
index 8a7ad4290ab..f4d41f0d102 100644
--- a/src/cmd/go.sum
+++ b/src/cmd/go.sum
@@ -1,22 +1,22 @@
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
-github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5 h1:zIaiqGYDQwa4HVx5wGRTXbx38Pqxjemn4BP98wpzpXo=
-github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
+github.com/google/pprof v0.0.0-20210506205249-923b5ab0fc1a h1:jmAp/2PZAScNd62lTD3Mcb0Ey9FvIIJtLohPhtxZJ+Q=
+github.com/google/pprof v0.0.0-20210506205249-923b5ab0fc1a/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639 h1:mV02weKRL81bEnm8A0HT1/CAelMQDBuQIfLw8n+d6xI=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 golang.org/x/arch v0.0.0-20210502124803-cbf565b21d1e h1:pv3V0NlNSh5Q6AX/StwGLBjcLS7UN4m4Gq+V+uSecqM=
 golang.org/x/arch v0.0.0-20210502124803-cbf565b21d1e/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e h1:8foAy0aoO5GkqCvAEJ4VC4P3zksTg4X4aJCDpZzmgQI=
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
-golang.org/x/mod v0.4.3-0.20210504181020-67f1c1edc27a h1:wbpC/7Wbo5WFVox32n+KjhRRLmTLq8YW/wRlL2iVAhk=
-golang.org/x/mod v0.4.3-0.20210504181020-67f1c1edc27a/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/mod v0.4.3-0.20210608190319-0f08993efd8a h1:e8qnjKz4EE6OjRki9wTadWSIogINvq10sMcuBRORxMY=
+golang.org/x/mod v0.4.3-0.20210608190319-0f08993efd8a/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6 h1:cdsMqa2nXzqlgs183pHxtvoVwU7CyzaCTAUOg94af4c=
-golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744 h1:yhBbb4IRs2HS9PPlAg6DMC6mUOKexJBNsLf4Z+6En1Q=
+golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20210503060354-a79de5458b56 h1:b8jxX3zqjpqb2LklXPzKSGJhzyxCOZSz8ncv8Nv+y7w=
 golang.org/x/term v0.0.0-20210503060354-a79de5458b56/go.mod h1:tfny5GFUkzUvx4ps4ajbZsCe5lw1metzhBm9T3x7oIY=
-golang.org/x/tools v0.1.1-0.20210505014545-7cab0ef2e9a5 h1:ImcI7RFHWLu2QWpFDXaReu0j+sQAHIy65vUFZImXiqY=
-golang.org/x/tools v0.1.1-0.20210505014545-7cab0ef2e9a5/go.mod h1:sH/Eidr0EddymY8HZSakBo32zU3fG5ovDq874hJLjVg=
+golang.org/x/tools v0.1.6-0.20210809225032-337cebd2c151 h1:jHjT6WuVKEMzjJgrS1+r1wk54oxwqumUnvtn0QZXyXE=
+golang.org/x/tools v0.1.6-0.20210809225032-337cebd2c151/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 052b61c03dd..7f88d3216cf 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -174,8 +174,8 @@
 // 		a build will run as if the disk file path exists with the contents
 // 		given by the backing file paths, or as if the disk file path does not
 // 		exist if its backing file path is empty. Support for the -overlay flag
-// 		has some limitations:importantly, cgo files included from outside the
-// 		include path must be  in the same directory as the Go package they are
+// 		has some limitations: importantly, cgo files included from outside the
+// 		include path must be in the same directory as the Go package they are
 // 		included from, and overlays will not appear when binaries and tests are
 // 		run through go run and go test respectively.
 // 	-pkgdir dir
@@ -293,7 +293,7 @@
 //
 // Usage:
 //
-// 	go doc [-u] [-c] [package|[package.]symbol[.methodOrField]]
+// 	go doc [doc flags] [package|[package.]symbol[.methodOrField]]
 //
 // Doc prints the documentation comments associated with the item identified by its
 // arguments (a package, const, func, type, var, method, or struct field)
@@ -1078,7 +1078,7 @@
 //
 // Usage:
 //
-// 	go mod edit [editing flags] [go.mod]
+// 	go mod edit [editing flags] [-fmt|-print|-json] [go.mod]
 //
 // Edit provides a command-line interface for editing go.mod,
 // for use primarily by tools or scripts. It reads only go.mod;
@@ -1186,13 +1186,17 @@
 //
 // Usage:
 //
-// 	go mod graph
+// 	go mod graph [-go=version]
 //
 // Graph prints the module requirement graph (with replacements applied)
 // in text form. Each line in the output has two space-separated fields: a module
 // and one of its requirements. Each module is identified as a string of the form
 // path@version, except for the main module, which has no @version suffix.
 //
+// The -go flag causes graph to report the module graph as loaded by the
+// given Go version, instead of the version indicated by the 'go' directive
+// in the go.mod file.
+//
 // See https://golang.org/ref/mod#go-mod-graph for more about 'go mod graph'.
 //
 //
@@ -1200,7 +1204,7 @@
 //
 // Usage:
 //
-// 	go mod init [module]
+// 	go mod init [module-path]
 //
 // Init initializes and writes a new go.mod file in the current directory, in
 // effect creating a new module rooted at the current directory. The go.mod file
@@ -1221,7 +1225,7 @@
 //
 // Usage:
 //
-// 	go mod tidy [-e] [-v] [-go=version]
+// 	go mod tidy [-e] [-v] [-go=version] [-compat=version]
 //
 // Tidy makes sure go.mod matches the source code in the module.
 // It adds any missing modules necessary to build the current module's
@@ -1241,6 +1245,14 @@
 // (Go versions 1.17 and higher retain more requirements in order to
 // support lazy module loading.)
 //
+// The -compat flag preserves any additional checksums needed for the
+// 'go' command from the indicated major Go release to successfully load
+// the module graph, and causes tidy to error out if that version of the
+// 'go' command would load any imported package from a different module
+// version. By default, tidy acts as if the -compat flag were set to the
+// version prior to the one indicated by the 'go' directive in the go.mod
+// file.
+//
 // See https://golang.org/ref/mod#go-mod-tidy for more about 'go mod tidy'.
 //
 //
@@ -1560,7 +1572,7 @@
 //
 // A build constraint, also known as a build tag, is a line comment that begins
 //
-// 	// +build
+// 	//go:build
 //
 // that lists the conditions under which a file should be included in the package.
 // Constraints may appear in any kind of source file (not just Go), but
@@ -1568,30 +1580,20 @@
 // only by blank lines and other line comments. These rules mean that in Go
 // files a build constraint must appear before the package clause.
 //
-// To distinguish build constraints from package documentation, a series of
-// build constraints must be followed by a blank line.
+// To distinguish build constraints from package documentation,
+// a build constraint should be followed by a blank line.
 //
-// A build constraint is evaluated as the OR of space-separated options.
-// Each option evaluates as the AND of its comma-separated terms.
-// Each term consists of letters, digits, underscores, and dots.
-// A term may be negated with a preceding !.
-// For example, the build constraint:
+// A build constraint is evaluated as an expression containing options
+// combined by ||, &&, and ! operators and parentheses. Operators have
+// the same meaning as in Go.
 //
-// 	// +build linux,386 darwin,!cgo
+// For example, the following build constraint constrains a file to
+// build when the "linux" and "386" constraints are satisfied, or when
+// "darwin" is satisfied and "cgo" is not:
 //
-// corresponds to the boolean formula:
+// 	//go:build (linux && 386) || (darwin && !cgo)
 //
-// 	(linux AND 386) OR (darwin AND (NOT cgo))
-//
-// A file may have multiple build constraints. The overall constraint is the AND
-// of the individual constraints. That is, the build constraints:
-//
-// 	// +build linux darwin
-// 	// +build amd64
-//
-// corresponds to the boolean formula:
-//
-// 	(linux OR darwin) AND amd64
+// It is an error for a file to have more than one //go:build line.
 //
 // During a particular build, the following words are satisfied:
 //
@@ -1629,24 +1631,28 @@
 //
 // To keep a file from being considered for the build:
 //
-// 	// +build ignore
+// 	//go:build ignore
 //
 // (any other unsatisfied word will work as well, but "ignore" is conventional.)
 //
 // To build a file only when using cgo, and only on Linux and OS X:
 //
-// 	// +build linux,cgo darwin,cgo
+// 	//go:build cgo && (linux || darwin)
 //
 // Such a file is usually paired with another file implementing the
 // default functionality for other systems, which in this case would
 // carry the constraint:
 //
-// 	// +build !linux,!darwin !cgo
+// 	//go:build !(cgo && (linux || darwin))
 //
 // Naming a file dns_windows.go will cause it to be included only when
 // building the package for Windows; similarly, math_386.s will be included
 // only when building the package for 32-bit x86.
 //
+// Go versions 1.16 and earlier used a different syntax for build constraints,
+// with a "// +build" prefix. The gofmt command will add an equivalent //go:build
+// constraint when encountering the older syntax.
+//
 //
 // Build modes
 //
@@ -1885,6 +1891,9 @@
 // 	GOMIPS64
 // 		For GOARCH=mips64{,le}, whether to use floating point instructions.
 // 		Valid values are hardfloat (default), softfloat.
+// 	GOPPC64
+// 		For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
+// 		Valid values are power8 (default), power9.
 // 	GOWASM
 // 		For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
 // 		Valid values are satconv, signext.
@@ -1894,6 +1903,12 @@
 // 	GCCGOTOOLDIR
 // 		If set, where to find gccgo tools, such as cgo.
 // 		The default is based on how gccgo was configured.
+// 	GOEXPERIMENT
+// 		Comma-separated list of toolchain experiments to enable or disable.
+// 		The list of available experiments may change arbitrarily over time.
+// 		See src/internal/goexperiment/flags.go for currently valid values.
+// 		Warning: This variable is provided for the development and testing
+// 		of the Go toolchain itself. Use beyond that purpose is unsupported.
 // 	GOROOT_FINAL
 // 		The root of the installed Go tree, when it is
 // 		installed in a location other than where it is built.
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 52b11fbb20d..8a091c5dbef 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -72,7 +72,6 @@ func tooSlow(t *testing.T) {
 // (temp) directory.
 var testGOROOT string
 
-var testCC string
 var testGOCACHE string
 
 var testGo string
@@ -179,13 +178,6 @@ func TestMain(m *testing.M) {
 			os.Exit(2)
 		}
 
-		out, err = exec.Command(gotool, "env", "CC").CombinedOutput()
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "could not find testing CC: %v\n%s", err, out)
-			os.Exit(2)
-		}
-		testCC = strings.TrimSpace(string(out))
-
 		cmd := exec.Command(testGo, "env", "CGO_ENABLED")
 		cmd.Stderr = new(strings.Builder)
 		if out, err := cmd.Output(); err != nil {
@@ -814,7 +806,9 @@ func TestNewReleaseRebuildsStalePackagesInGOPATH(t *testing.T) {
 		"src/internal/abi",
 		"src/internal/bytealg",
 		"src/internal/cpu",
+		"src/internal/goarch",
 		"src/internal/goexperiment",
+		"src/internal/goos",
 		"src/math/bits",
 		"src/unsafe",
 		filepath.Join("pkg", runtime.GOOS+"_"+runtime.GOARCH),
@@ -2193,7 +2187,7 @@ func testBuildmodePIE(t *testing.T, useCgo, setBuildmodeToPIE bool) {
 			// See https://sourceware.org/bugzilla/show_bug.cgi?id=19011
 			section := f.Section(".edata")
 			if section == nil {
-				t.Fatalf(".edata section is not present")
+				t.Skip(".edata section is not present")
 			}
 			// TODO: deduplicate this struct from cmd/link/internal/ld/pe.go
 			type IMAGE_EXPORT_DIRECTORY struct {
@@ -2864,3 +2858,35 @@ func TestExecInDeletedDir(t *testing.T) {
 	// `go version` should not fail
 	tg.run("version")
 }
+
+// A missing C compiler should not force the net package to be stale.
+// Issue 47215.
+func TestMissingCC(t *testing.T) {
+	if !canCgo {
+		t.Skip("test is only meaningful on systems with cgo")
+	}
+	cc := os.Getenv("CC")
+	if cc == "" {
+		cc = "gcc"
+	}
+	if filepath.IsAbs(cc) {
+		t.Skipf(`"CC" (%s) is an absolute path`, cc)
+	}
+	_, err := exec.LookPath(cc)
+	if err != nil {
+		t.Skipf(`"CC" (%s) not on PATH`, cc)
+	}
+
+	tg := testgo(t)
+	defer tg.cleanup()
+	netStale, _ := tg.isStale("net")
+	if netStale {
+		t.Skip(`skipping test because "net" package is currently stale`)
+	}
+
+	tg.setenv("PATH", "") // No C compiler on PATH.
+	netStale, _ = tg.isStale("net")
+	if netStale {
+		t.Error(`clearing "PATH" causes "net" to be stale`)
+	}
+}
diff --git a/src/cmd/go/internal/base/base.go b/src/cmd/go/internal/base/base.go
index 954ce47a989..0144525e307 100644
--- a/src/cmd/go/internal/base/base.go
+++ b/src/cmd/go/internal/base/base.go
@@ -17,7 +17,7 @@ import (
 	"sync"
 
 	"cmd/go/internal/cfg"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 )
 
 // A Command is an implementation of a go command
diff --git a/src/cmd/go/internal/base/flag.go b/src/cmd/go/internal/base/flag.go
index 677f8196827..6914efa0e6f 100644
--- a/src/cmd/go/internal/base/flag.go
+++ b/src/cmd/go/internal/base/flag.go
@@ -9,7 +9,7 @@ import (
 
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/fsys"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 )
 
 // A StringsFlag is a command-line flag that interprets its argument
diff --git a/src/cmd/go/internal/cfg/cfg.go b/src/cmd/go/internal/cfg/cfg.go
index b47eb812b59..57a3c1ff6fb 100644
--- a/src/cmd/go/internal/cfg/cfg.go
+++ b/src/cmd/go/internal/cfg/cfg.go
@@ -77,6 +77,14 @@ func defaultContext() build.Context {
 	ctxt.GOOS = envOr("GOOS", ctxt.GOOS)
 	ctxt.GOARCH = envOr("GOARCH", ctxt.GOARCH)
 
+	// The experiments flags are based on GOARCH, so they may
+	// need to change.  TODO: This should be cleaned up.
+	buildcfg.UpdateExperiments(ctxt.GOOS, ctxt.GOARCH, envOr("GOEXPERIMENT", buildcfg.DefaultGOEXPERIMENT))
+	ctxt.ToolTags = nil
+	for _, exp := range buildcfg.EnabledExperiments() {
+		ctxt.ToolTags = append(ctxt.ToolTags, "goexperiment."+exp)
+	}
+
 	// The go/build rule for whether cgo is enabled is:
 	//	1. If $CGO_ENABLED is set, respect it.
 	//	2. Otherwise, if this is a cross-compile, disable cgo.
diff --git a/src/cmd/go/internal/doc/doc.go b/src/cmd/go/internal/doc/doc.go
index 67f76e22563..8580a5dc4d2 100644
--- a/src/cmd/go/internal/doc/doc.go
+++ b/src/cmd/go/internal/doc/doc.go
@@ -13,7 +13,7 @@ import (
 
 var CmdDoc = &base.Command{
 	Run:         runDoc,
-	UsageLine:   "go doc [-u] [-c] [package|[package.]symbol[.methodOrField]]",
+	UsageLine:   "go doc [doc flags] [package|[package.]symbol[.methodOrField]]",
 	CustomFlags: true,
 	Short:       "show documentation for package or symbol",
 	Long: `
diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index b30c37ab27c..1553d263914 100644
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -10,6 +10,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"go/build"
+	"internal/buildcfg"
 	"io"
 	"os"
 	"path/filepath"
@@ -72,6 +73,7 @@ func MkEnv() []cfg.EnvVar {
 		{Name: "GOCACHE", Value: cache.DefaultDir()},
 		{Name: "GOENV", Value: envFile},
 		{Name: "GOEXE", Value: cfg.ExeSuffix},
+		{Name: "GOEXPERIMENT", Value: buildcfg.GOEXPERIMENT()},
 		{Name: "GOFLAGS", Value: cfg.Getenv("GOFLAGS")},
 		{Name: "GOHOSTARCH", Value: runtime.GOARCH},
 		{Name: "GOHOSTOS", Value: runtime.GOOS},
@@ -197,6 +199,21 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 	if *envU && *envW {
 		base.Fatalf("go env: cannot use -u with -w")
 	}
+
+	// Handle 'go env -w' and 'go env -u' before calling buildcfg.Check,
+	// so they can be used to recover from an invalid configuration.
+	if *envW {
+		runEnvW(args)
+		return
+	}
+
+	if *envU {
+		runEnvU(args)
+		return
+	}
+
+	buildcfg.Check()
+
 	env := cfg.CmdEnv
 	env = append(env, ExtraEnvVars()...)
 
@@ -206,14 +223,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 
 	// Do we need to call ExtraEnvVarsCostly, which is a bit expensive?
 	needCostly := false
-	if *envU || *envW {
-		// We're overwriting or removing default settings,
-		// so it doesn't really matter what the existing settings are.
-		//
-		// Moreover, we haven't validated the new settings yet, so it is
-		// important that we NOT perform any actions based on them,
-		// such as initializing the builder to compute other variables.
-	} else if len(args) == 0 {
+	if len(args) == 0 {
 		// We're listing all environment variables ("go env"),
 		// including the expensive ones.
 		needCostly = true
@@ -238,95 +248,6 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 		env = append(env, ExtraEnvVarsCostly()...)
 	}
 
-	if *envW {
-		// Process and sanity-check command line.
-		if len(args) == 0 {
-			base.Fatalf("go env -w: no KEY=VALUE arguments given")
-		}
-		osEnv := make(map[string]string)
-		for _, e := range cfg.OrigEnv {
-			if i := strings.Index(e, "="); i >= 0 {
-				osEnv[e[:i]] = e[i+1:]
-			}
-		}
-		add := make(map[string]string)
-		for _, arg := range args {
-			i := strings.Index(arg, "=")
-			if i < 0 {
-				base.Fatalf("go env -w: arguments must be KEY=VALUE: invalid argument: %s", arg)
-			}
-			key, val := arg[:i], arg[i+1:]
-			if err := checkEnvWrite(key, val); err != nil {
-				base.Fatalf("go env -w: %v", err)
-			}
-			if _, ok := add[key]; ok {
-				base.Fatalf("go env -w: multiple values for key: %s", key)
-			}
-			add[key] = val
-			if osVal := osEnv[key]; osVal != "" && osVal != val {
-				fmt.Fprintf(os.Stderr, "warning: go env -w %s=... does not override conflicting OS environment variable\n", key)
-			}
-		}
-
-		goos, okGOOS := add["GOOS"]
-		goarch, okGOARCH := add["GOARCH"]
-		if okGOOS || okGOARCH {
-			if !okGOOS {
-				goos = cfg.Goos
-			}
-			if !okGOARCH {
-				goarch = cfg.Goarch
-			}
-			if err := work.CheckGOOSARCHPair(goos, goarch); err != nil {
-				base.Fatalf("go env -w: %v", err)
-			}
-		}
-
-		gotmp, okGOTMP := add["GOTMPDIR"]
-		if okGOTMP {
-			if !filepath.IsAbs(gotmp) && gotmp != "" {
-				base.Fatalf("go env -w: GOTMPDIR must be an absolute path")
-			}
-		}
-
-		updateEnvFile(add, nil)
-		return
-	}
-
-	if *envU {
-		// Process and sanity-check command line.
-		if len(args) == 0 {
-			base.Fatalf("go env -u: no arguments given")
-		}
-		del := make(map[string]bool)
-		for _, arg := range args {
-			if err := checkEnvWrite(arg, ""); err != nil {
-				base.Fatalf("go env -u: %v", err)
-			}
-			del[arg] = true
-		}
-		if del["GOOS"] || del["GOARCH"] {
-			goos, goarch := cfg.Goos, cfg.Goarch
-			if del["GOOS"] {
-				goos = getOrigEnv("GOOS")
-				if goos == "" {
-					goos = build.Default.GOOS
-				}
-			}
-			if del["GOARCH"] {
-				goarch = getOrigEnv("GOARCH")
-				if goarch == "" {
-					goarch = build.Default.GOARCH
-				}
-			}
-			if err := work.CheckGOOSARCHPair(goos, goarch); err != nil {
-				base.Fatalf("go env -u: %v", err)
-			}
-		}
-		updateEnvFile(nil, del)
-		return
-	}
-
 	if len(args) > 0 {
 		if *envJson {
 			var es []cfg.EnvVar
@@ -351,6 +272,109 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 	PrintEnv(os.Stdout, env)
 }
 
+func runEnvW(args []string) {
+	// Process and sanity-check command line.
+	if len(args) == 0 {
+		base.Fatalf("go env -w: no KEY=VALUE arguments given")
+	}
+	osEnv := make(map[string]string)
+	for _, e := range cfg.OrigEnv {
+		if i := strings.Index(e, "="); i >= 0 {
+			osEnv[e[:i]] = e[i+1:]
+		}
+	}
+	add := make(map[string]string)
+	for _, arg := range args {
+		i := strings.Index(arg, "=")
+		if i < 0 {
+			base.Fatalf("go env -w: arguments must be KEY=VALUE: invalid argument: %s", arg)
+		}
+		key, val := arg[:i], arg[i+1:]
+		if err := checkEnvWrite(key, val); err != nil {
+			base.Fatalf("go env -w: %v", err)
+		}
+		if _, ok := add[key]; ok {
+			base.Fatalf("go env -w: multiple values for key: %s", key)
+		}
+		add[key] = val
+		if osVal := osEnv[key]; osVal != "" && osVal != val {
+			fmt.Fprintf(os.Stderr, "warning: go env -w %s=... does not override conflicting OS environment variable\n", key)
+		}
+	}
+
+	if err := checkBuildConfig(add, nil); err != nil {
+		base.Fatalf("go env -w: %v", err)
+	}
+
+	gotmp, okGOTMP := add["GOTMPDIR"]
+	if okGOTMP {
+		if !filepath.IsAbs(gotmp) && gotmp != "" {
+			base.Fatalf("go env -w: GOTMPDIR must be an absolute path")
+		}
+	}
+
+	updateEnvFile(add, nil)
+}
+
+func runEnvU(args []string) {
+	// Process and sanity-check command line.
+	if len(args) == 0 {
+		base.Fatalf("go env -u: no arguments given")
+	}
+	del := make(map[string]bool)
+	for _, arg := range args {
+		if err := checkEnvWrite(arg, ""); err != nil {
+			base.Fatalf("go env -u: %v", err)
+		}
+		del[arg] = true
+	}
+
+	if err := checkBuildConfig(nil, del); err != nil {
+		base.Fatalf("go env -u: %v", err)
+	}
+
+	updateEnvFile(nil, del)
+}
+
+// checkBuildConfig checks whether the build configuration is valid
+// after the specified configuration environment changes are applied.
+func checkBuildConfig(add map[string]string, del map[string]bool) error {
+	// get returns the value for key after applying add and del and
+	// reports whether it changed. cur should be the current value
+	// (i.e., before applying changes) and def should be the default
+	// value (i.e., when no environment variables are provided at all).
+	get := func(key, cur, def string) (string, bool) {
+		if val, ok := add[key]; ok {
+			return val, true
+		}
+		if del[key] {
+			val := getOrigEnv(key)
+			if val == "" {
+				val = def
+			}
+			return val, true
+		}
+		return cur, false
+	}
+
+	goos, okGOOS := get("GOOS", cfg.Goos, build.Default.GOOS)
+	goarch, okGOARCH := get("GOARCH", cfg.Goarch, build.Default.GOARCH)
+	if okGOOS || okGOARCH {
+		if err := work.CheckGOOSARCHPair(goos, goarch); err != nil {
+			return err
+		}
+	}
+
+	goexperiment, okGOEXPERIMENT := get("GOEXPERIMENT", buildcfg.GOEXPERIMENT(), "")
+	if okGOEXPERIMENT {
+		if _, _, err := buildcfg.ParseGOEXPERIMENT(goos, goarch, goexperiment); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // PrintEnv prints the environment variables to w.
 func PrintEnv(w io.Writer, env []cfg.EnvVar) {
 	for _, e := range env {
diff --git a/src/cmd/go/internal/fix/fix.go b/src/cmd/go/internal/fix/fix.go
index 988d45e71cc..cc5940fccd8 100644
--- a/src/cmd/go/internal/fix/fix.go
+++ b/src/cmd/go/internal/fix/fix.go
@@ -10,7 +10,7 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 	"context"
 	"fmt"
 	"os"
diff --git a/src/cmd/go/internal/fmtcmd/fmt.go b/src/cmd/go/internal/fmtcmd/fmt.go
index 8a040087539..2b89a078acc 100644
--- a/src/cmd/go/internal/fmtcmd/fmt.go
+++ b/src/cmd/go/internal/fmtcmd/fmt.go
@@ -18,7 +18,7 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 )
 
 func init() {
diff --git a/src/cmd/go/internal/generate/generate.go b/src/cmd/go/internal/generate/generate.go
index 80ea32b4284..d7f2eb46107 100644
--- a/src/cmd/go/internal/generate/generate.go
+++ b/src/cmd/go/internal/generate/generate.go
@@ -25,8 +25,8 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
 	"cmd/go/internal/work"
+	"cmd/internal/str"
 )
 
 var CmdGenerate = &base.Command{
diff --git a/src/cmd/go/internal/get/get.go b/src/cmd/go/internal/get/get.go
index 3c16dc3040f..836364e39b6 100644
--- a/src/cmd/go/internal/get/get.go
+++ b/src/cmd/go/internal/get/get.go
@@ -17,10 +17,10 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
 	"cmd/go/internal/vcs"
 	"cmd/go/internal/web"
 	"cmd/go/internal/work"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 )
diff --git a/src/cmd/go/internal/help/helpdoc.go b/src/cmd/go/internal/help/helpdoc.go
index 2f86e4195d9..490ff1fb7cf 100644
--- a/src/cmd/go/internal/help/helpdoc.go
+++ b/src/cmd/go/internal/help/helpdoc.go
@@ -598,6 +598,9 @@ Architecture-specific environment variables:
 	GOMIPS64
 		For GOARCH=mips64{,le}, whether to use floating point instructions.
 		Valid values are hardfloat (default), softfloat.
+	GOPPC64
+		For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
+		Valid values are power8 (default), power9.
 	GOWASM
 		For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
 		Valid values are satconv, signext.
@@ -607,6 +610,12 @@ Special-purpose environment variables:
 	GCCGOTOOLDIR
 		If set, where to find gccgo tools, such as cgo.
 		The default is based on how gccgo was configured.
+	GOEXPERIMENT
+		Comma-separated list of toolchain experiments to enable or disable.
+		The list of available experiments may change arbitrarily over time.
+		See src/internal/goexperiment/flags.go for currently valid values.
+		Warning: This variable is provided for the development and testing
+		of the Go toolchain itself. Use beyond that purpose is unsupported.
 	GOROOT_FINAL
 		The root of the installed Go tree, when it is
 		installed in a location other than where it is built.
@@ -784,7 +793,7 @@ var HelpBuildConstraint = &base.Command{
 	Long: `
 A build constraint, also known as a build tag, is a line comment that begins
 
-	// +build
+	//go:build
 
 that lists the conditions under which a file should be included in the package.
 Constraints may appear in any kind of source file (not just Go), but
@@ -792,30 +801,20 @@ they must appear near the top of the file, preceded
 only by blank lines and other line comments. These rules mean that in Go
 files a build constraint must appear before the package clause.
 
-To distinguish build constraints from package documentation, a series of
-build constraints must be followed by a blank line.
+To distinguish build constraints from package documentation,
+a build constraint should be followed by a blank line.
 
-A build constraint is evaluated as the OR of space-separated options.
-Each option evaluates as the AND of its comma-separated terms.
-Each term consists of letters, digits, underscores, and dots.
-A term may be negated with a preceding !.
-For example, the build constraint:
+A build constraint is evaluated as an expression containing options
+combined by ||, &&, and ! operators and parentheses. Operators have
+the same meaning as in Go.
 
-	// +build linux,386 darwin,!cgo
+For example, the following build constraint constrains a file to
+build when the "linux" and "386" constraints are satisfied, or when
+"darwin" is satisfied and "cgo" is not:
 
-corresponds to the boolean formula:
+	//go:build (linux && 386) || (darwin && !cgo)
 
-	(linux AND 386) OR (darwin AND (NOT cgo))
-
-A file may have multiple build constraints. The overall constraint is the AND
-of the individual constraints. That is, the build constraints:
-
-	// +build linux darwin
-	// +build amd64
-
-corresponds to the boolean formula:
-
-	(linux OR darwin) AND amd64
+It is an error for a file to have more than one //go:build line.
 
 During a particular build, the following words are satisfied:
 
@@ -853,22 +852,26 @@ in addition to ios tags and files.
 
 To keep a file from being considered for the build:
 
-	// +build ignore
+	//go:build ignore
 
 (any other unsatisfied word will work as well, but "ignore" is conventional.)
 
 To build a file only when using cgo, and only on Linux and OS X:
 
-	// +build linux,cgo darwin,cgo
+	//go:build cgo && (linux || darwin)
 
 Such a file is usually paired with another file implementing the
 default functionality for other systems, which in this case would
 carry the constraint:
 
-	// +build !linux,!darwin !cgo
+	//go:build !(cgo && (linux || darwin))
 
 Naming a file dns_windows.go will cause it to be included only when
 building the package for Windows; similarly, math_386.s will be included
 only when building the package for 32-bit x86.
+
+Go versions 1.16 and earlier used a different syntax for build constraints,
+with a "// +build" prefix. The gofmt command will add an equivalent //go:build
+constraint when encountering the older syntax.
 `,
 }
diff --git a/src/cmd/go/internal/imports/read.go b/src/cmd/go/internal/imports/read.go
index 5e270781d77..70d51904505 100644
--- a/src/cmd/go/internal/imports/read.go
+++ b/src/cmd/go/internal/imports/read.go
@@ -8,6 +8,7 @@ package imports
 
 import (
 	"bufio"
+	"bytes"
 	"errors"
 	"io"
 	"unicode/utf8"
@@ -22,6 +23,19 @@ type importReader struct {
 	nerr int
 }
 
+var bom = []byte{0xef, 0xbb, 0xbf}
+
+func newImportReader(b *bufio.Reader) *importReader {
+	// Remove leading UTF-8 BOM.
+	// Per https://golang.org/ref/spec#Source_code_representation:
+	// a compiler may ignore a UTF-8-encoded byte order mark (U+FEFF)
+	// if it is the first Unicode code point in the source text.
+	if leadingBytes, err := b.Peek(3); err == nil && bytes.Equal(leadingBytes, bom) {
+		b.Discard(3)
+	}
+	return &importReader{b: b}
+}
+
 func isIdent(c byte) bool {
 	return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '_' || c >= utf8.RuneSelf
 }
@@ -201,7 +215,7 @@ func (r *importReader) readImport(imports *[]string) {
 // ReadComments is like io.ReadAll, except that it only reads the leading
 // block of comments in the file.
 func ReadComments(f io.Reader) ([]byte, error) {
-	r := &importReader{b: bufio.NewReader(f)}
+	r := newImportReader(bufio.NewReader(f))
 	r.peekByte(true)
 	if r.err == nil && !r.eof {
 		// Didn't reach EOF, so must have found a non-space byte. Remove it.
@@ -213,7 +227,7 @@ func ReadComments(f io.Reader) ([]byte, error) {
 // ReadImports is like io.ReadAll, except that it expects a Go file as input
 // and stops reading the input once the imports have completed.
 func ReadImports(f io.Reader, reportSyntaxError bool, imports *[]string) ([]byte, error) {
-	r := &importReader{b: bufio.NewReader(f)}
+	r := newImportReader(bufio.NewReader(f))
 
 	r.readKeyword("package")
 	r.readIdent()
diff --git a/src/cmd/go/internal/imports/read_test.go b/src/cmd/go/internal/imports/read_test.go
index 6ea356f1ff0..6a1a6524a11 100644
--- a/src/cmd/go/internal/imports/read_test.go
+++ b/src/cmd/go/internal/imports/read_test.go
@@ -66,6 +66,10 @@ var readImportsTests = []readTest{
 		`,
 		"",
 	},
+	{
+		"\ufeff𝔻" + `package p; import "x";ℙvar x = 1`,
+		"",
+	},
 }
 
 var readCommentsTests = []readTest{
@@ -81,6 +85,10 @@ var readCommentsTests = []readTest{
 		`ℙpackage p; import . "x"`,
 		"",
 	},
+	{
+		"\ufeff𝔻" + `ℙpackage p; import . "x"`,
+		"",
+	},
 	{
 		`// foo
 
@@ -90,6 +98,19 @@ var readCommentsTests = []readTest{
 		
 		/*/ zot */
 
+		// asdf
+		ℙHello, world`,
+		"",
+	},
+	{
+		"\ufeff𝔻" + `// foo
+
+		/* bar */
+
+		/* quux */ // baz
+
+		/*/ zot */
+
 		// asdf
 		ℙHello, world`,
 		"",
@@ -107,6 +128,11 @@ func testRead(t *testing.T, tests []readTest, read func(io.Reader) ([]byte, erro
 			in = tt.in[:j] + tt.in[j+len("ℙ"):]
 			testOut = tt.in[:j]
 		}
+		d := strings.Index(tt.in, "𝔻")
+		if d >= 0 {
+			in = in[:d] + in[d+len("𝔻"):]
+			testOut = testOut[d+len("𝔻"):]
+		}
 		r := strings.NewReader(in)
 		buf, err := read(r)
 		if err != nil {
diff --git a/src/cmd/go/internal/list/list.go b/src/cmd/go/internal/list/list.go
index 53aaf311ec4..4b8c0e9f482 100644
--- a/src/cmd/go/internal/list/list.go
+++ b/src/cmd/go/internal/list/list.go
@@ -23,8 +23,8 @@ import (
 	"cmd/go/internal/load"
 	"cmd/go/internal/modinfo"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
 	"cmd/go/internal/work"
+	"cmd/internal/str"
 )
 
 var CmdList = &base.Command{
@@ -724,8 +724,18 @@ func runList(ctx context.Context, cmd *base.Command, args []string) {
 
 	// Record non-identity import mappings in p.ImportMap.
 	for _, p := range pkgs {
-		for i, srcPath := range p.Internal.RawImports {
-			path := p.Imports[i]
+		nRaw := len(p.Internal.RawImports)
+		for i, path := range p.Imports {
+			var srcPath string
+			if i < nRaw {
+				srcPath = p.Internal.RawImports[i]
+			} else {
+				// This path is not within the raw imports, so it must be an import
+				// found only within CompiledGoFiles. Those paths are found in
+				// CompiledImports.
+				srcPath = p.Internal.CompiledImports[i-nRaw]
+			}
+
 			if path != srcPath {
 				if p.ImportMap == nil {
 					p.ImportMap = make(map[string]string)
diff --git a/src/cmd/go/internal/load/flag.go b/src/cmd/go/internal/load/flag.go
index 440cb861344..4e0cb5bc19e 100644
--- a/src/cmd/go/internal/load/flag.go
+++ b/src/cmd/go/internal/load/flag.go
@@ -6,7 +6,7 @@ package load
 
 import (
 	"cmd/go/internal/base"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 	"fmt"
 	"strings"
 )
diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go
index fa040bf5b11..f5f0f353931 100644
--- a/src/cmd/go/internal/load/pkg.go
+++ b/src/cmd/go/internal/load/pkg.go
@@ -36,8 +36,8 @@ import (
 	"cmd/go/internal/modload"
 	"cmd/go/internal/par"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
 	"cmd/go/internal/trace"
+	"cmd/internal/str"
 	"cmd/internal/sys"
 
 	"golang.org/x/mod/modfile"
@@ -87,6 +87,7 @@ type PackagePublic struct {
 	CgoFiles          []string `json:",omitempty"` // .go source files that import "C"
 	CompiledGoFiles   []string `json:",omitempty"` // .go output from running cgo on CgoFiles
 	IgnoredGoFiles    []string `json:",omitempty"` // .go source files ignored due to build constraints
+	InvalidGoFiles    []string `json:",omitempty"` // .go source files with detected problems (parse error, wrong package name, and so on)
 	IgnoredOtherFiles []string `json:",omitempty"` // non-.go source files ignored due to build constraints
 	CFiles            []string `json:",omitempty"` // .c source files
 	CXXFiles          []string `json:",omitempty"` // .cc, .cpp and .cxx source files
@@ -144,6 +145,7 @@ func (p *Package) AllFiles() []string {
 		p.CgoFiles,
 		// no p.CompiledGoFiles, because they are from GoFiles or generated by us
 		p.IgnoredGoFiles,
+		// no p.InvalidGoFiles, because they are from GoFiles
 		p.IgnoredOtherFiles,
 		p.CFiles,
 		p.CXXFiles,
@@ -192,8 +194,8 @@ type PackageInternal struct {
 	// Unexported fields are not part of the public API.
 	Build             *build.Package
 	Imports           []*Package           // this package's direct imports
-	CompiledImports   []string             // additional Imports necessary when using CompiledGoFiles (all from standard library)
-	RawImports        []string             // this package's original imports as they appear in the text of the program
+	CompiledImports   []string             // additional Imports necessary when using CompiledGoFiles (all from standard library); 1:1 with the end of PackagePublic.Imports
+	RawImports        []string             // this package's original imports as they appear in the text of the program; 1:1 with the end of PackagePublic.Imports
 	ForceLibrary      bool                 // this package is a library (even if named "main")
 	CmdlineFiles      bool                 // package built from files listed on command line
 	CmdlinePkg        bool                 // package listed on command line
@@ -371,6 +373,7 @@ func (p *Package) copyBuild(opts PackageOpts, pp *build.Package) {
 	p.GoFiles = pp.GoFiles
 	p.CgoFiles = pp.CgoFiles
 	p.IgnoredGoFiles = pp.IgnoredGoFiles
+	p.InvalidGoFiles = pp.InvalidGoFiles
 	p.IgnoredOtherFiles = pp.IgnoredOtherFiles
 	p.CFiles = pp.CFiles
 	p.CXXFiles = pp.CXXFiles
@@ -852,7 +855,9 @@ func loadPackageData(ctx context.Context, path, parentPath, parentDir, parentRoo
 				buildMode = build.ImportComment
 			}
 			data.p, data.err = cfg.BuildContext.ImportDir(r.dir, buildMode)
-			if data.p.Root == "" && cfg.ModulesEnabled {
+			if cfg.ModulesEnabled {
+				// Override data.p.Root, since ImportDir sets it to $GOPATH, if
+				// the module is inside $GOPATH/src.
 				if info := modload.PackageModuleInfo(ctx, path); info != nil {
 					data.p.Root = info.Dir
 				}
@@ -1800,35 +1805,37 @@ func (p *Package) load(ctx context.Context, opts PackageOpts, path string, stk *
 		}
 	}
 
-	// Cgo translation adds imports of "unsafe", "runtime/cgo" and "syscall",
-	// except for certain packages, to avoid circular dependencies.
-	if p.UsesCgo() {
-		addImport("unsafe", true)
-	}
-	if p.UsesCgo() && (!p.Standard || !cgoExclude[p.ImportPath]) && cfg.BuildContext.Compiler != "gccgo" {
-		addImport("runtime/cgo", true)
-	}
-	if p.UsesCgo() && (!p.Standard || !cgoSyscallExclude[p.ImportPath]) {
-		addImport("syscall", true)
-	}
-
-	// SWIG adds imports of some standard packages.
-	if p.UsesSwig() {
-		addImport("unsafe", true)
-		if cfg.BuildContext.Compiler != "gccgo" {
+	if !opts.IgnoreImports {
+		// Cgo translation adds imports of "unsafe", "runtime/cgo" and "syscall",
+		// except for certain packages, to avoid circular dependencies.
+		if p.UsesCgo() {
+			addImport("unsafe", true)
+		}
+		if p.UsesCgo() && (!p.Standard || !cgoExclude[p.ImportPath]) && cfg.BuildContext.Compiler != "gccgo" {
 			addImport("runtime/cgo", true)
 		}
-		addImport("syscall", true)
-		addImport("sync", true)
+		if p.UsesCgo() && (!p.Standard || !cgoSyscallExclude[p.ImportPath]) {
+			addImport("syscall", true)
+		}
 
-		// TODO: The .swig and .swigcxx files can use
-		// %go_import directives to import other packages.
-	}
+		// SWIG adds imports of some standard packages.
+		if p.UsesSwig() {
+			addImport("unsafe", true)
+			if cfg.BuildContext.Compiler != "gccgo" {
+				addImport("runtime/cgo", true)
+			}
+			addImport("syscall", true)
+			addImport("sync", true)
 
-	// The linker loads implicit dependencies.
-	if p.Name == "main" && !p.Internal.ForceLibrary {
-		for _, dep := range LinkerDeps(p) {
-			addImport(dep, false)
+			// TODO: The .swig and .swigcxx files can use
+			// %go_import directives to import other packages.
+		}
+
+		// The linker loads implicit dependencies.
+		if p.Name == "main" && !p.Internal.ForceLibrary {
+			for _, dep := range LinkerDeps(p) {
+				addImport(dep, false)
+			}
 		}
 	}
 
@@ -2390,7 +2397,9 @@ func LoadImportWithFlags(path, srcDir string, parent *Package, stk *ImportStack,
 // PackageOpts control the behavior of PackagesAndErrors and other package
 // loading functions.
 type PackageOpts struct {
-	// IgnoreImports controls whether we ignore imports when loading packages.
+	// IgnoreImports controls whether we ignore explicit and implicit imports
+	// when loading packages.  Implicit imports are added when supporting Cgo
+	// or SWIG and when linking main packages.
 	IgnoreImports bool
 
 	// ModResolveTests indicates whether calls to the module loader should also
@@ -2499,7 +2508,7 @@ func PackagesAndErrors(ctx context.Context, opts PackageOpts, patterns []string)
 	}
 
 	if opts.MainOnly {
-		pkgs = mainPackagesOnly(pkgs, patterns)
+		pkgs = mainPackagesOnly(pkgs, matches)
 	}
 
 	// Now that CmdlinePkg is set correctly,
@@ -2553,50 +2562,63 @@ func CheckPackageErrors(pkgs []*Package) {
 // mainPackagesOnly filters out non-main packages matched only by arguments
 // containing "..." and returns the remaining main packages.
 //
+// Packages with missing, invalid, or ambiguous names may be treated as
+// possibly-main packages.
+//
 // mainPackagesOnly sets a non-main package's Error field and returns it if it
 // is named by a literal argument.
 //
 // mainPackagesOnly prints warnings for non-literal arguments that only match
 // non-main packages.
-func mainPackagesOnly(pkgs []*Package, patterns []string) []*Package {
-	matchers := make([]func(string) bool, len(patterns))
-	for i, p := range patterns {
-		if strings.Contains(p, "...") {
-			matchers[i] = search.MatchPattern(p)
+func mainPackagesOnly(pkgs []*Package, matches []*search.Match) []*Package {
+	treatAsMain := map[string]bool{}
+	for _, m := range matches {
+		if m.IsLiteral() {
+			for _, path := range m.Pkgs {
+				treatAsMain[path] = true
+			}
 		}
 	}
 
-	matchedPkgs := make([]*Package, 0, len(pkgs))
-	mainCount := make([]int, len(patterns))
-	nonMainCount := make([]int, len(patterns))
+	var mains []*Package
 	for _, pkg := range pkgs {
-		if pkg.Name == "main" || (pkg.Incomplete && pkg.Name == "") {
-			matchedPkgs = append(matchedPkgs, pkg)
-			for i := range patterns {
-				if matchers[i] != nil && matchers[i](pkg.ImportPath) {
-					mainCount[i]++
-				}
-			}
-		} else {
-			for i := range patterns {
-				if matchers[i] == nil && patterns[i] == pkg.ImportPath {
-					if pkg.Error == nil {
-						pkg.Error = &PackageError{Err: &mainPackageError{importPath: pkg.ImportPath}}
-					}
-					matchedPkgs = append(matchedPkgs, pkg)
-				} else if matchers[i] != nil && matchers[i](pkg.ImportPath) {
-					nonMainCount[i]++
-				}
-			}
+		if pkg.Name == "main" {
+			treatAsMain[pkg.ImportPath] = true
+			mains = append(mains, pkg)
+			continue
 		}
-	}
-	for i, p := range patterns {
-		if matchers[i] != nil && mainCount[i] == 0 && nonMainCount[i] > 0 {
-			fmt.Fprintf(os.Stderr, "go: warning: %q matched no main packages\n", p)
+
+		if len(pkg.InvalidGoFiles) > 0 { // TODO(#45999): && pkg.Name == "", but currently go/build sets pkg.Name arbitrarily if it is ambiguous.
+			// The package has (or may have) conflicting names, and we can't easily
+			// tell whether one of them is "main". So assume that it could be, and
+			// report an error for the package.
+			treatAsMain[pkg.ImportPath] = true
+		}
+		if treatAsMain[pkg.ImportPath] {
+			if pkg.Error == nil {
+				pkg.Error = &PackageError{Err: &mainPackageError{importPath: pkg.ImportPath}}
+			}
+			mains = append(mains, pkg)
 		}
 	}
 
-	return matchedPkgs
+	for _, m := range matches {
+		if m.IsLiteral() || len(m.Pkgs) == 0 {
+			continue
+		}
+		foundMain := false
+		for _, path := range m.Pkgs {
+			if treatAsMain[path] {
+				foundMain = true
+				break
+			}
+		}
+		if !foundMain {
+			fmt.Fprintf(os.Stderr, "go: warning: %q matched only non-main packages\n", m.Pattern())
+		}
+	}
+
+	return mains
 }
 
 type mainPackageError struct {
diff --git a/src/cmd/go/internal/load/test.go b/src/cmd/go/internal/load/test.go
index 6baa1db14f0..42eefe37ba5 100644
--- a/src/cmd/go/internal/load/test.go
+++ b/src/cmd/go/internal/load/test.go
@@ -22,8 +22,8 @@ import (
 	"unicode/utf8"
 
 	"cmd/go/internal/fsys"
-	"cmd/go/internal/str"
 	"cmd/go/internal/trace"
+	"cmd/internal/str"
 )
 
 var TestMainDeps = []string{
@@ -116,7 +116,7 @@ func TestPackagesAndErrors(ctx context.Context, opts PackageOpts, p *Package, co
 			// Can't change that code, because that code is only for loading the
 			// non-test copy of a package.
 			ptestErr = &PackageError{
-				ImportStack:   testImportStack(stk[0], p1, p.ImportPath),
+				ImportStack:   importCycleStack(p1, p.ImportPath),
 				Err:           errors.New("import cycle not allowed in test"),
 				IsImportCycle: true,
 			}
@@ -375,22 +375,44 @@ func TestPackagesAndErrors(ctx context.Context, opts PackageOpts, p *Package, co
 	return pmain, ptest, pxtest
 }
 
-func testImportStack(top string, p *Package, target string) []string {
-	stk := []string{top, p.ImportPath}
-Search:
-	for p.ImportPath != target {
-		for _, p1 := range p.Internal.Imports {
-			if p1.ImportPath == target || str.Contains(p1.Deps, target) {
-				stk = append(stk, p1.ImportPath)
-				p = p1
-				continue Search
+// importCycleStack returns an import stack from p to the package whose import
+// path is target.
+func importCycleStack(p *Package, target string) []string {
+	// importerOf maps each import path to its importer nearest to p.
+	importerOf := map[string]string{p.ImportPath: ""}
+
+	// q is a breadth-first queue of packages to search for target.
+	// Every package added to q has a corresponding entry in pathTo.
+	//
+	// We search breadth-first for two reasons:
+	//
+	// 	1. We want to report the shortest cycle.
+	//
+	// 	2. If p contains multiple cycles, the first cycle we encounter might not
+	// 	   contain target. To ensure termination, we have to break all cycles
+	// 	   other than the first.
+	q := []*Package{p}
+
+	for len(q) > 0 {
+		p := q[0]
+		q = q[1:]
+		if path := p.ImportPath; path == target {
+			var stk []string
+			for path != "" {
+				stk = append(stk, path)
+				path = importerOf[path]
+			}
+			return stk
+		}
+		for _, dep := range p.Internal.Imports {
+			if _, ok := importerOf[dep.ImportPath]; !ok {
+				importerOf[dep.ImportPath] = p.ImportPath
+				q = append(q, dep)
 			}
 		}
-		// Can't happen, but in case it does...
-		stk = append(stk, "")
-		break
 	}
-	return stk
+
+	panic("lost path to cycle")
 }
 
 // recompileForTest copies and replaces certain packages in pmain's dependency
diff --git a/src/cmd/go/internal/lockedfile/lockedfile_filelock.go b/src/cmd/go/internal/lockedfile/lockedfile_filelock.go
index 729df5c681c..e4923f68764 100644
--- a/src/cmd/go/internal/lockedfile/lockedfile_filelock.go
+++ b/src/cmd/go/internal/lockedfile/lockedfile_filelock.go
@@ -11,7 +11,6 @@ import (
 	"io/fs"
 	"os"
 
-	"cmd/go/internal/fsys"
 	"cmd/go/internal/lockedfile/internal/filelock"
 )
 
@@ -21,7 +20,7 @@ func openFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
 	// calls for Linux and Windows anyway, so it's simpler to use that approach
 	// consistently.
 
-	f, err := fsys.OpenFile(name, flag&^os.O_TRUNC, perm)
+	f, err := os.OpenFile(name, flag&^os.O_TRUNC, perm)
 	if err != nil {
 		return nil, err
 	}
diff --git a/src/cmd/go/internal/lockedfile/lockedfile_plan9.go b/src/cmd/go/internal/lockedfile/lockedfile_plan9.go
index 3d4b97d78e5..979118b10ae 100644
--- a/src/cmd/go/internal/lockedfile/lockedfile_plan9.go
+++ b/src/cmd/go/internal/lockedfile/lockedfile_plan9.go
@@ -13,8 +13,6 @@ import (
 	"os"
 	"strings"
 	"time"
-
-	"cmd/go/internal/fsys"
 )
 
 // Opening an exclusive-use file returns an error.
@@ -59,7 +57,7 @@ func openFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
 	// If the file was unpacked or created by some other program, it might not
 	// have the ModeExclusive bit set. Set it before we call OpenFile, so that we
 	// can be confident that a successful OpenFile implies exclusive use.
-	if fi, err := fsys.Stat(name); err == nil {
+	if fi, err := os.Stat(name); err == nil {
 		if fi.Mode()&fs.ModeExclusive == 0 {
 			if err := os.Chmod(name, fi.Mode()|fs.ModeExclusive); err != nil {
 				return nil, err
@@ -72,7 +70,7 @@ func openFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
 	nextSleep := 1 * time.Millisecond
 	const maxSleep = 500 * time.Millisecond
 	for {
-		f, err := fsys.OpenFile(name, flag, perm|fs.ModeExclusive)
+		f, err := os.OpenFile(name, flag, perm|fs.ModeExclusive)
 		if err == nil {
 			return f, nil
 		}
diff --git a/src/cmd/go/internal/modcmd/download.go b/src/cmd/go/internal/modcmd/download.go
index a6c6d914e1d..0e5af852376 100644
--- a/src/cmd/go/internal/modcmd/download.go
+++ b/src/cmd/go/internal/modcmd/download.go
@@ -86,9 +86,11 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 	if !modload.HasModRoot() && len(args) == 0 {
 		base.Fatalf("go mod download: no modules specified (see 'go help mod download')")
 	}
-	if len(args) == 0 {
+	haveExplicitArgs := len(args) > 0
+	if !haveExplicitArgs {
 		args = []string{"all"}
-	} else if modload.HasModRoot() {
+	}
+	if modload.HasModRoot() {
 		modload.LoadModFile(ctx) // to fill Target
 		targetAtUpgrade := modload.Target.Path + "@upgrade"
 		targetAtPatch := modload.Target.Path + "@patch"
@@ -135,6 +137,18 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 	type token struct{}
 	sem := make(chan token, runtime.GOMAXPROCS(0))
 	infos, infosErr := modload.ListModules(ctx, args, 0)
+	if !haveExplicitArgs {
+		// 'go mod download' is sometimes run without arguments to pre-populate the
+		// module cache. It may fetch modules that aren't needed to build packages
+		// in the main mdoule. This is usually not intended, so don't save sums for
+		// downloaded modules (golang.org/issue/45332).
+		// TODO(golang.org/issue/45551): For now, in ListModules, save sums needed
+		// to load the build list (same as 1.15 behavior). In the future, report an
+		// error if go.mod or go.sum need to be updated after loading the build
+		// list.
+		modload.DisallowWriteGoMod()
+	}
+
 	for _, info := range infos {
 		if info.Replace != nil {
 			info = info.Replace
@@ -185,8 +199,15 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 		base.ExitIfErrors()
 	}
 
-	// Update go.mod and especially go.sum if needed.
-	modload.WriteGoMod(ctx)
+	// If there were explicit arguments, update go.mod and especially go.sum.
+	// 'go mod download mod@version' is a useful way to add a sum without using
+	// 'go get mod@version', which may have other side effects. We print this in
+	// some error message hints.
+	//
+	// Don't save sums for 'go mod download' without arguments; see comment above.
+	if haveExplicitArgs {
+		modload.WriteGoMod(ctx)
+	}
 
 	// If there was an error matching some of the requested packages, emit it now
 	// (after we've written the checksums for the modules that were downloaded
diff --git a/src/cmd/go/internal/modcmd/edit.go b/src/cmd/go/internal/modcmd/edit.go
index 79a93ca44b9..bb3d5210926 100644
--- a/src/cmd/go/internal/modcmd/edit.go
+++ b/src/cmd/go/internal/modcmd/edit.go
@@ -25,7 +25,7 @@ import (
 )
 
 var cmdEdit = &base.Command{
-	UsageLine: "go mod edit [editing flags] [go.mod]",
+	UsageLine: "go mod edit [editing flags] [-fmt|-print|-json] [go.mod]",
 	Short:     "edit go.mod from tools or scripts",
 	Long: `
 Edit provides a command-line interface for editing go.mod,
@@ -196,7 +196,7 @@ func runEdit(ctx context.Context, cmd *base.Command, args []string) {
 
 	if *editGo != "" {
 		if !modfile.GoVersionRE.MatchString(*editGo) {
-			base.Fatalf(`go mod: invalid -go option; expecting something like "-go 1.12"`)
+			base.Fatalf(`go mod: invalid -go option; expecting something like "-go %s"`, modload.LatestGoVersion())
 		}
 	}
 
diff --git a/src/cmd/go/internal/modcmd/graph.go b/src/cmd/go/internal/modcmd/graph.go
index 77853304e9d..ac81f26dade 100644
--- a/src/cmd/go/internal/modcmd/graph.go
+++ b/src/cmd/go/internal/modcmd/graph.go
@@ -18,7 +18,7 @@ import (
 )
 
 var cmdGraph = &base.Command{
-	UsageLine: "go mod graph",
+	UsageLine: "go mod graph [-go=version]",
 	Short:     "print module requirement graph",
 	Long: `
 Graph prints the module requirement graph (with replacements applied)
@@ -26,12 +26,21 @@ in text form. Each line in the output has two space-separated fields: a module
 and one of its requirements. Each module is identified as a string of the form
 path@version, except for the main module, which has no @version suffix.
 
+The -go flag causes graph to report the module graph as loaded by the
+given Go version, instead of the version indicated by the 'go' directive
+in the go.mod file.
+
 See https://golang.org/ref/mod#go-mod-graph for more about 'go mod graph'.
 	`,
 	Run: runGraph,
 }
 
+var (
+	graphGo goVersionFlag
+)
+
 func init() {
+	cmdGraph.Flag.Var(&graphGo, "go", "")
 	base.AddModCommonFlags(&cmdGraph.Flag)
 }
 
@@ -41,7 +50,7 @@ func runGraph(ctx context.Context, cmd *base.Command, args []string) {
 	}
 	modload.ForceUseModules = true
 	modload.RootMode = modload.NeedRoot
-	mg := modload.LoadModGraph(ctx)
+	mg := modload.LoadModGraph(ctx, graphGo.String())
 
 	w := bufio.NewWriter(os.Stdout)
 	defer w.Flush()
diff --git a/src/cmd/go/internal/modcmd/init.go b/src/cmd/go/internal/modcmd/init.go
index 73cc282d814..958c3066ac1 100644
--- a/src/cmd/go/internal/modcmd/init.go
+++ b/src/cmd/go/internal/modcmd/init.go
@@ -13,7 +13,7 @@ import (
 )
 
 var cmdInit = &base.Command{
-	UsageLine: "go mod init [module]",
+	UsageLine: "go mod init [module-path]",
 	Short:     "initialize new module in current directory",
 	Long: `
 Init initializes and writes a new go.mod file in the current directory, in
diff --git a/src/cmd/go/internal/modcmd/tidy.go b/src/cmd/go/internal/modcmd/tidy.go
index c72ec30a572..fe25507e94f 100644
--- a/src/cmd/go/internal/modcmd/tidy.go
+++ b/src/cmd/go/internal/modcmd/tidy.go
@@ -12,12 +12,14 @@ import (
 	"cmd/go/internal/imports"
 	"cmd/go/internal/modload"
 	"context"
+	"fmt"
 
 	"golang.org/x/mod/modfile"
+	"golang.org/x/mod/semver"
 )
 
 var cmdTidy = &base.Command{
-	UsageLine: "go mod tidy [-e] [-v] [-go=version]",
+	UsageLine: "go mod tidy [-e] [-v] [-go=version] [-compat=version]",
 	Short:     "add missing and remove unused modules",
 	Long: `
 Tidy makes sure go.mod matches the source code in the module.
@@ -38,34 +40,64 @@ are retained as explicit requirements in the go.mod file.
 (Go versions 1.17 and higher retain more requirements in order to
 support lazy module loading.)
 
+The -compat flag preserves any additional checksums needed for the
+'go' command from the indicated major Go release to successfully load
+the module graph, and causes tidy to error out if that version of the
+'go' command would load any imported package from a different module
+version. By default, tidy acts as if the -compat flag were set to the
+version prior to the one indicated by the 'go' directive in the go.mod
+file.
+
 See https://golang.org/ref/mod#go-mod-tidy for more about 'go mod tidy'.
 	`,
 	Run: runTidy,
 }
 
 var (
-	tidyE  bool   // if true, report errors but proceed anyway.
-	tidyGo string // go version to write to the tidied go.mod file (toggles lazy loading)
+	tidyE      bool          // if true, report errors but proceed anyway.
+	tidyGo     goVersionFlag // go version to write to the tidied go.mod file (toggles lazy loading)
+	tidyCompat goVersionFlag // go version for which the tidied go.mod and go.sum files should be “compatible”
 )
 
 func init() {
 	cmdTidy.Flag.BoolVar(&cfg.BuildV, "v", false, "")
 	cmdTidy.Flag.BoolVar(&tidyE, "e", false, "")
-	cmdTidy.Flag.StringVar(&tidyGo, "go", "", "")
+	cmdTidy.Flag.Var(&tidyGo, "go", "")
+	cmdTidy.Flag.Var(&tidyCompat, "compat", "")
 	base.AddModCommonFlags(&cmdTidy.Flag)
 }
 
+// A goVersionFlag is a flag.Value representing a supported Go version.
+//
+// (Note that the -go argument to 'go mod edit' is *not* a goVersionFlag.
+// It intentionally allows newer-than-supported versions as arguments.)
+type goVersionFlag struct {
+	v string
+}
+
+func (f *goVersionFlag) String() string   { return f.v }
+func (f *goVersionFlag) Get() interface{} { return f.v }
+
+func (f *goVersionFlag) Set(s string) error {
+	if s != "" {
+		latest := modload.LatestGoVersion()
+		if !modfile.GoVersionRE.MatchString(s) {
+			return fmt.Errorf("expecting a Go version like %q", latest)
+		}
+		if semver.Compare("v"+s, "v"+latest) > 0 {
+			return fmt.Errorf("maximum supported Go version is %s", latest)
+		}
+	}
+
+	f.v = s
+	return nil
+}
+
 func runTidy(ctx context.Context, cmd *base.Command, args []string) {
 	if len(args) > 0 {
 		base.Fatalf("go mod tidy: no arguments allowed")
 	}
 
-	if tidyGo != "" {
-		if !modfile.GoVersionRE.MatchString(tidyGo) {
-			base.Fatalf(`go mod: invalid -go option %q; expecting something like "-go 1.17"`, tidyGo)
-		}
-	}
-
 	// Tidy aims to make 'go test' reproducible for any package in 'all', so we
 	// need to include test dependencies. For modules that specify go 1.15 or
 	// earlier this is a no-op (because 'all' saturates transitive test
@@ -80,9 +112,10 @@ func runTidy(ctx context.Context, cmd *base.Command, args []string) {
 	modload.RootMode = modload.NeedRoot
 
 	modload.LoadPackages(ctx, modload.PackageOpts{
-		GoVersion:                tidyGo,
+		GoVersion:                tidyGo.String(),
 		Tags:                     imports.AnyTags(),
 		Tidy:                     true,
+		TidyCompatibleVersion:    tidyCompat.String(),
 		VendorModulesInGOROOTSrc: true,
 		ResolveMissingImports:    true,
 		LoadTests:                true,
diff --git a/src/cmd/go/internal/modcmd/vendor.go b/src/cmd/go/internal/modcmd/vendor.go
index 8e1c0432f72..b133ba7ea93 100644
--- a/src/cmd/go/internal/modcmd/vendor.go
+++ b/src/cmd/go/internal/modcmd/vendor.go
@@ -13,6 +13,7 @@ import (
 	"io"
 	"io/fs"
 	"os"
+	"path"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -23,7 +24,7 @@ import (
 	"cmd/go/internal/imports"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 	"golang.org/x/mod/semver"
@@ -299,7 +300,7 @@ func copyMetadata(modPath, pkg, dst, src string, copiedFiles map[string]bool) {
 		if modPath == pkg {
 			break
 		}
-		pkg = filepath.Dir(pkg)
+		pkg = path.Dir(pkg)
 		dst = filepath.Dir(dst)
 		src = filepath.Dir(src)
 	}
diff --git a/src/cmd/go/internal/modcmd/verify.go b/src/cmd/go/internal/modcmd/verify.go
index 5c321c783ae..5a6eca32cfb 100644
--- a/src/cmd/go/internal/modcmd/verify.go
+++ b/src/cmd/go/internal/modcmd/verify.go
@@ -54,7 +54,8 @@ func runVerify(ctx context.Context, cmd *base.Command, args []string) {
 	sem := make(chan token, runtime.GOMAXPROCS(0))
 
 	// Use a slice of result channels, so that the output is deterministic.
-	mods := modload.LoadModGraph(ctx).BuildList()[1:]
+	const defaultGoVersion = ""
+	mods := modload.LoadModGraph(ctx, defaultGoVersion).BuildList()[1:]
 	errsChans := make([]<-chan []error, len(mods))
 
 	for i, mod := range mods {
diff --git a/src/cmd/go/internal/modfetch/cache.go b/src/cmd/go/internal/modfetch/cache.go
index f3b58a172a6..b01b4674131 100644
--- a/src/cmd/go/internal/modfetch/cache.go
+++ b/src/cmd/go/internal/modfetch/cache.go
@@ -152,7 +152,7 @@ func lockVersion(mod module.Version) (unlock func(), err error) {
 // If err is nil, the caller MUST eventually call the unlock function.
 func SideLock() (unlock func(), err error) {
 	if err := checkCacheDir(); err != nil {
-		base.Fatalf("go: %v", err)
+		return nil, err
 	}
 
 	path := filepath.Join(cfg.GOMODCACHE, "cache", "lock")
diff --git a/src/cmd/go/internal/modfetch/codehost/codehost.go b/src/cmd/go/internal/modfetch/codehost/codehost.go
index 378fbae34f9..efb4b1516a2 100644
--- a/src/cmd/go/internal/modfetch/codehost/codehost.go
+++ b/src/cmd/go/internal/modfetch/codehost/codehost.go
@@ -21,7 +21,7 @@ import (
 
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/lockedfile"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 )
 
 // Downloaded size limits.
diff --git a/src/cmd/go/internal/modfetch/codehost/git_test.go b/src/cmd/go/internal/modfetch/codehost/git_test.go
index 89a73baad9d..a684fa1a9bb 100644
--- a/src/cmd/go/internal/modfetch/codehost/git_test.go
+++ b/src/cmd/go/internal/modfetch/codehost/git_test.go
@@ -8,7 +8,6 @@ import (
 	"archive/zip"
 	"bytes"
 	"flag"
-	"fmt"
 	"internal/testenv"
 	"io"
 	"io/fs"
@@ -47,12 +46,6 @@ var altRepos = []string{
 var localGitRepo string
 
 func testMain(m *testing.M) int {
-	if _, err := exec.LookPath("git"); err != nil {
-		fmt.Fprintln(os.Stderr, "skipping because git binary not found")
-		fmt.Println("PASS")
-		return 0
-	}
-
 	dir, err := os.MkdirTemp("", "gitrepo-test-")
 	if err != nil {
 		log.Fatal(err)
@@ -60,23 +53,25 @@ func testMain(m *testing.M) int {
 	defer os.RemoveAll(dir)
 
 	if testenv.HasExternalNetwork() && testenv.HasExec() {
-		// Clone gitrepo1 into a local directory.
-		// If we use a file:// URL to access the local directory,
-		// then git starts up all the usual protocol machinery,
-		// which will let us test remote git archive invocations.
-		localGitRepo = filepath.Join(dir, "gitrepo2")
-		if _, err := Run("", "git", "clone", "--mirror", gitrepo1, localGitRepo); err != nil {
-			log.Fatal(err)
-		}
-		if _, err := Run(localGitRepo, "git", "config", "daemon.uploadarch", "true"); err != nil {
-			log.Fatal(err)
+		if _, err := exec.LookPath("git"); err == nil {
+			// Clone gitrepo1 into a local directory.
+			// If we use a file:// URL to access the local directory,
+			// then git starts up all the usual protocol machinery,
+			// which will let us test remote git archive invocations.
+			localGitRepo = filepath.Join(dir, "gitrepo2")
+			if _, err := Run("", "git", "clone", "--mirror", gitrepo1, localGitRepo); err != nil {
+				log.Fatal(err)
+			}
+			if _, err := Run(localGitRepo, "git", "config", "daemon.uploadarch", "true"); err != nil {
+				log.Fatal(err)
+			}
 		}
 	}
 
 	return m.Run()
 }
 
-func testRepo(remote string) (Repo, error) {
+func testRepo(t *testing.T, remote string) (Repo, error) {
 	if remote == "localGitRepo" {
 		// Convert absolute path to file URL. LocalGitRepo will not accept
 		// Windows absolute paths because they look like a host:path remote.
@@ -87,15 +82,17 @@ func testRepo(remote string) (Repo, error) {
 		} else {
 			url = "file:///" + filepath.ToSlash(localGitRepo)
 		}
+		testenv.MustHaveExecPath(t, "git")
 		return LocalGitRepo(url)
 	}
-	kind := "git"
+	vcs := "git"
 	for _, k := range []string{"hg"} {
 		if strings.Contains(remote, "/"+k+"/") {
-			kind = k
+			vcs = k
 		}
 	}
-	return NewRepo(kind, remote)
+	testenv.MustHaveExecPath(t, vcs)
+	return NewRepo(vcs, remote)
 }
 
 var tagsTests = []struct {
@@ -116,7 +113,7 @@ func TestTags(t *testing.T) {
 
 	for _, tt := range tagsTests {
 		f := func(t *testing.T) {
-			r, err := testRepo(tt.repo)
+			r, err := testRepo(t, tt.repo)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -168,7 +165,7 @@ func TestLatest(t *testing.T) {
 
 	for _, tt := range latestTests {
 		f := func(t *testing.T) {
-			r, err := testRepo(tt.repo)
+			r, err := testRepo(t, tt.repo)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -221,7 +218,7 @@ func TestReadFile(t *testing.T) {
 
 	for _, tt := range readFileTests {
 		f := func(t *testing.T) {
-			r, err := testRepo(tt.repo)
+			r, err := testRepo(t, tt.repo)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -412,7 +409,7 @@ func TestReadZip(t *testing.T) {
 
 	for _, tt := range readZipTests {
 		f := func(t *testing.T) {
-			r, err := testRepo(tt.repo)
+			r, err := testRepo(t, tt.repo)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -581,7 +578,7 @@ func TestStat(t *testing.T) {
 
 	for _, tt := range statTests {
 		f := func(t *testing.T) {
-			r, err := testRepo(tt.repo)
+			r, err := testRepo(t, tt.repo)
 			if err != nil {
 				t.Fatal(err)
 			}
diff --git a/src/cmd/go/internal/modfetch/codehost/vcs.go b/src/cmd/go/internal/modfetch/codehost/vcs.go
index c2cca084e30..5d810d2621c 100644
--- a/src/cmd/go/internal/modfetch/codehost/vcs.go
+++ b/src/cmd/go/internal/modfetch/codehost/vcs.go
@@ -20,7 +20,7 @@ import (
 
 	"cmd/go/internal/lockedfile"
 	"cmd/go/internal/par"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 )
 
 // A VCSError indicates an error using a version control system.
diff --git a/src/cmd/go/internal/modfetch/coderepo.go b/src/cmd/go/internal/modfetch/coderepo.go
index f817a045834..dfef9f73c27 100644
--- a/src/cmd/go/internal/modfetch/coderepo.go
+++ b/src/cmd/go/internal/modfetch/coderepo.go
@@ -864,22 +864,25 @@ func (r *codeRepo) GoMod(version string) (data []byte, err error) {
 	data, err = r.code.ReadFile(rev, path.Join(dir, "go.mod"), codehost.MaxGoMod)
 	if err != nil {
 		if os.IsNotExist(err) {
-			return r.legacyGoMod(rev, dir), nil
+			return LegacyGoMod(r.modPath), nil
 		}
 		return nil, err
 	}
 	return data, nil
 }
 
-func (r *codeRepo) legacyGoMod(rev, dir string) []byte {
-	// We used to try to build a go.mod reflecting pre-existing
-	// package management metadata files, but the conversion
-	// was inherently imperfect (because those files don't have
-	// exactly the same semantics as go.mod) and, when done
-	// for dependencies in the middle of a build, impossible to
-	// correct. So we stopped.
-	// Return a fake go.mod that simply declares the module path.
-	return []byte(fmt.Sprintf("module %s\n", modfile.AutoQuote(r.modPath)))
+// LegacyGoMod generates a fake go.mod file for a module that doesn't have one.
+// The go.mod file contains a module directive and nothing else: no go version,
+// no requirements.
+//
+// We used to try to build a go.mod reflecting pre-existing
+// package management metadata files, but the conversion
+// was inherently imperfect (because those files don't have
+// exactly the same semantics as go.mod) and, when done
+// for dependencies in the middle of a build, impossible to
+// correct. So we stopped.
+func LegacyGoMod(modPath string) []byte {
+	return []byte(fmt.Sprintf("module %s\n", modfile.AutoQuote(modPath)))
 }
 
 func (r *codeRepo) modPrefix(rev string) string {
diff --git a/src/cmd/go/internal/modfetch/fetch.go b/src/cmd/go/internal/modfetch/fetch.go
index e40593abae8..d3d30d970b3 100644
--- a/src/cmd/go/internal/modfetch/fetch.go
+++ b/src/cmd/go/internal/modfetch/fetch.go
@@ -22,6 +22,7 @@ import (
 
 	"cmd/go/internal/base"
 	"cmd/go/internal/cfg"
+	"cmd/go/internal/fsys"
 	"cmd/go/internal/lockedfile"
 	"cmd/go/internal/par"
 	"cmd/go/internal/robustio"
@@ -416,7 +417,18 @@ func initGoSum() (bool, error) {
 
 	goSum.m = make(map[module.Version][]string)
 	goSum.status = make(map[modSum]modSumStatus)
-	data, err := lockedfile.Read(GoSumFile)
+	var (
+		data []byte
+		err  error
+	)
+	if actualSumFile, ok := fsys.OverlayPath(GoSumFile); ok {
+		// Don't lock go.sum if it's part of the overlay.
+		// On Plan 9, locking requires chmod, and we don't want to modify any file
+		// in the overlay. See #44700.
+		data, err = os.ReadFile(actualSumFile)
+	} else {
+		data, err = lockedfile.Read(GoSumFile)
+	}
 	if err != nil && !os.IsNotExist(err) {
 		return false, err
 	}
@@ -716,6 +728,9 @@ Outer:
 	if cfg.BuildMod == "readonly" {
 		base.Fatalf("go: updates to go.sum needed, disabled by -mod=readonly")
 	}
+	if _, ok := fsys.OverlayPath(GoSumFile); ok {
+		base.Fatalf("go: updates to go.sum needed, but go.sum is part of the overlay specified with -overlay")
+	}
 
 	// Make a best-effort attempt to acquire the side lock, only to exclude
 	// previous versions of the 'go' command from making simultaneous edits.
diff --git a/src/cmd/go/internal/modget/get.go b/src/cmd/go/internal/modget/get.go
index 3a24b6a2f7e..9672e5598e0 100644
--- a/src/cmd/go/internal/modget/get.go
+++ b/src/cmd/go/internal/modget/get.go
@@ -38,6 +38,7 @@ import (
 	"cmd/go/internal/base"
 	"cmd/go/internal/imports"
 	"cmd/go/internal/load"
+	"cmd/go/internal/modfetch"
 	"cmd/go/internal/modload"
 	"cmd/go/internal/par"
 	"cmd/go/internal/search"
@@ -386,14 +387,14 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 		}
 		load.CheckPackageErrors(pkgs)
 
-		haveExe := false
+		haveExternalExe := false
 		for _, pkg := range pkgs {
-			if pkg.Name == "main" {
-				haveExe = true
+			if pkg.Name == "main" && pkg.Module != nil && pkg.Module.Path != modload.Target.Path {
+				haveExternalExe = true
 				break
 			}
 		}
-		if haveExe {
+		if haveExternalExe {
 			fmt.Fprint(os.Stderr, "go get: installing executables with 'go get' in module mode is deprecated.")
 			var altMsg string
 			if modload.HasModRoot() {
@@ -505,7 +506,8 @@ type versionReason struct {
 func newResolver(ctx context.Context, queries []*query) *resolver {
 	// LoadModGraph also sets modload.Target, which is needed by various resolver
 	// methods.
-	mg := modload.LoadModGraph(ctx)
+	const defaultGoVersion = ""
+	mg := modload.LoadModGraph(ctx, defaultGoVersion)
 
 	buildList := mg.BuildList()
 	initialVersion := make(map[string]string, len(buildList))
@@ -1152,6 +1154,7 @@ func (r *resolver) loadPackages(ctx context.Context, patterns []string, findPack
 		Tags:                     imports.AnyTags(),
 		VendorModulesInGOROOTSrc: true,
 		LoadTests:                *getT,
+		AssumeRootsImported:      true, // After 'go get foo', imports of foo should build.
 		SilencePackageErrors:     true, // May be fixed by subsequent upgrades or downgrades.
 	}
 
@@ -1466,6 +1469,8 @@ func (r *resolver) chooseArbitrarily(cs pathSet) (isPackage bool, m module.Versi
 // checkPackageProblems reloads packages for the given patterns and reports
 // missing and ambiguous package errors. It also reports retractions and
 // deprecations for resolved modules and modules needed to build named packages.
+// It also adds a sum for each updated module in the build list if we had one
+// before and didn't get one while loading packages.
 //
 // We skip missing-package errors earlier in the process, since we want to
 // resolve pathSets ourselves, but at that point, we don't have enough context
@@ -1593,12 +1598,55 @@ func (r *resolver) checkPackageProblems(ctx context.Context, pkgPatterns []strin
 		})
 	}
 
+	// Load sums for updated modules that had sums before. When we update a
+	// module, we may update another module in the build list that provides a
+	// package in 'all' that wasn't loaded as part of this 'go get' command.
+	// If we don't add a sum for that module, builds may fail later.
+	// Note that an incidentally updated package could still import packages
+	// from unknown modules or from modules in the build list that we didn't
+	// need previously. We can't handle that case without loading 'all'.
+	sumErrs := make([]error, len(r.buildList))
+	for i := range r.buildList {
+		i := i
+		m := r.buildList[i]
+		mActual := m
+		if mRepl := modload.Replacement(m); mRepl.Path != "" {
+			mActual = mRepl
+		}
+		old := module.Version{Path: m.Path, Version: r.initialVersion[m.Path]}
+		if old.Version == "" {
+			continue
+		}
+		oldActual := old
+		if oldRepl := modload.Replacement(old); oldRepl.Path != "" {
+			oldActual = oldRepl
+		}
+		if mActual == oldActual || mActual.Version == "" || !modfetch.HaveSum(oldActual) {
+			continue
+		}
+		r.work.Add(func() {
+			if _, err := modfetch.DownloadZip(ctx, mActual); err != nil {
+				verb := "upgraded"
+				if semver.Compare(m.Version, old.Version) < 0 {
+					verb = "downgraded"
+				}
+				replaced := ""
+				if mActual != m {
+					replaced = fmt.Sprintf(" (replaced by %s)", mActual)
+				}
+				err = fmt.Errorf("%s %s %s => %s%s: error finding sum for %s: %v", verb, m.Path, old.Version, m.Version, replaced, mActual, err)
+				sumErrs[i] = err
+			}
+		})
+	}
+
 	<-r.work.Idle()
 
-	// Report deprecations, then retractions.
+	// Report deprecations, then retractions, then errors fetching sums.
+	// Only errors fetching sums are hard errors.
 	for _, mm := range deprecations {
 		if mm.message != "" {
-			fmt.Fprintf(os.Stderr, "go: warning: module %s is deprecated: %s\n", mm.m.Path, mm.message)
+			fmt.Fprintf(os.Stderr, "go: module %s is deprecated: %s\n", mm.m.Path, mm.message)
 		}
 	}
 	var retractPath string
@@ -1615,6 +1663,12 @@ func (r *resolver) checkPackageProblems(ctx context.Context, pkgPatterns []strin
 	if retractPath != "" {
 		fmt.Fprintf(os.Stderr, "go: to switch to the latest unretracted version, run:\n\tgo get %s@latest\n", retractPath)
 	}
+	for _, err := range sumErrs {
+		if err != nil {
+			base.Errorf("go: %v", err)
+		}
+	}
+	base.ExitIfErrors()
 }
 
 // reportChanges logs version changes to os.Stderr.
@@ -1750,7 +1804,8 @@ func (r *resolver) updateBuildList(ctx context.Context, additions []module.Versi
 		return false
 	}
 
-	r.buildList = modload.LoadModGraph(ctx).BuildList()
+	const defaultGoVersion = ""
+	r.buildList = modload.LoadModGraph(ctx, defaultGoVersion).BuildList()
 	r.buildListVersion = make(map[string]string, len(r.buildList))
 	for _, m := range r.buildList {
 		r.buildListVersion[m.Path] = m.Version
diff --git a/src/cmd/go/internal/modget/query.go b/src/cmd/go/internal/modget/query.go
index 1a5a60f7eb9..0a66517a499 100644
--- a/src/cmd/go/internal/modget/query.go
+++ b/src/cmd/go/internal/modget/query.go
@@ -14,7 +14,7 @@ import (
 	"cmd/go/internal/base"
 	"cmd/go/internal/modload"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 )
diff --git a/src/cmd/go/internal/modload/buildlist.go b/src/cmd/go/internal/modload/buildlist.go
index 7a0cea405e3..bf695673167 100644
--- a/src/cmd/go/internal/modload/buildlist.go
+++ b/src/cmd/go/internal/modload/buildlist.go
@@ -191,6 +191,19 @@ func (rs *Requirements) rootSelected(path string) (version string, ok bool) {
 	return "", false
 }
 
+// hasRedundantRoot returns true if the root list contains multiple requirements
+// of the same module or a requirement on any version of the main module.
+// Redundant requirements should be pruned, but they may influence version
+// selection.
+func (rs *Requirements) hasRedundantRoot() bool {
+	for i, m := range rs.rootModules {
+		if m.Path == Target.Path || (i > 0 && m.Path == rs.rootModules[i-1].Path) {
+			return true
+		}
+	}
+	return false
+}
+
 // Graph returns the graph of module requirements loaded from the current
 // root modules (as reported by RootModules).
 //
@@ -403,11 +416,33 @@ func (mg *ModuleGraph) allRootsSelected() bool {
 // LoadModGraph loads and returns the graph of module dependencies of the main module,
 // without loading any packages.
 //
+// If the goVersion string is non-empty, the returned graph is the graph
+// as interpreted by the given Go version (instead of the version indicated
+// in the go.mod file).
+//
 // Modules are loaded automatically (and lazily) in LoadPackages:
 // LoadModGraph need only be called if LoadPackages is not,
 // typically in commands that care about modules but no particular package.
-func LoadModGraph(ctx context.Context) *ModuleGraph {
-	rs, mg, err := expandGraph(ctx, LoadModFile(ctx))
+func LoadModGraph(ctx context.Context, goVersion string) *ModuleGraph {
+	rs := LoadModFile(ctx)
+
+	if goVersion != "" {
+		depth := modDepthFromGoVersion(goVersion)
+		if depth == eager && rs.depth != eager {
+			// Use newRequirements instead of convertDepth because convertDepth
+			// also updates roots; here, we want to report the unmodified roots
+			// even though they may seem inconsistent.
+			rs = newRequirements(eager, rs.rootModules, rs.direct)
+		}
+
+		mg, err := rs.Graph(ctx)
+		if err != nil {
+			base.Fatalf("go: %v", err)
+		}
+		return mg
+	}
+
+	rs, mg, err := expandGraph(ctx, rs)
 	if err != nil {
 		base.Fatalf("go: %v", err)
 	}
@@ -443,7 +478,7 @@ func expandGraph(ctx context.Context, rs *Requirements) (*Requirements, *ModuleG
 		// roots — but in a lazy module it may pull in previously-irrelevant
 		// transitive dependencies.
 
-		newRS, rsErr := updateRoots(ctx, rs.direct, rs, nil, nil)
+		newRS, rsErr := updateRoots(ctx, rs.direct, rs, nil, nil, false)
 		if rsErr != nil {
 			// Failed to update roots, perhaps because of an error in a transitive
 			// dependency needed for the update. Return the original Requirements
@@ -517,11 +552,11 @@ func tidyRoots(ctx context.Context, rs *Requirements, pkgs []*loadPkg) (*Require
 	return tidyLazyRoots(ctx, rs.direct, pkgs)
 }
 
-func updateRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version) (*Requirements, error) {
+func updateRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version, rootsImported bool) (*Requirements, error) {
 	if rs.depth == eager {
 		return updateEagerRoots(ctx, direct, rs, add)
 	}
-	return updateLazyRoots(ctx, direct, rs, pkgs, add)
+	return updateLazyRoots(ctx, direct, rs, pkgs, add, rootsImported)
 }
 
 // tidyLazyRoots returns a minimal set of root requirements that maintains the
@@ -661,7 +696,7 @@ func tidyLazyRoots(ctx context.Context, direct map[string]bool, pkgs []*loadPkg)
 //
 // (See https://golang.org/design/36460-lazy-module-loading#invariants for more
 // detail.)
-func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version) (*Requirements, error) {
+func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version, rootsImported bool) (*Requirements, error) {
 	roots := rs.rootModules
 	rootsUpgraded := false
 
@@ -688,6 +723,10 @@ func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requiremen
 			//
 			// (This is the “import invariant” that makes lazy loading possible.)
 
+		case rootsImported && pkg.flags.has(pkgFromRoot):
+			// pkg is a transitive dependency of some root, and we are treating the
+			// roots as if they are imported by the main module (as in 'go get').
+
 		case pkg.flags.has(pkgIsRoot):
 			// pkg is a root of the package-import graph. (Generally this means that
 			// it matches a command-line argument.) We want future invocations of the
@@ -815,7 +854,8 @@ func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requiremen
 
 		roots = make([]module.Version, 0, len(rs.rootModules))
 		rootsUpgraded = false
-		inRootPaths := make(map[string]bool, len(rs.rootModules))
+		inRootPaths := make(map[string]bool, len(rs.rootModules)+1)
+		inRootPaths[Target.Path] = true
 		for _, m := range rs.rootModules {
 			if inRootPaths[m.Path] {
 				// This root specifies a redundant path. We already retained the
@@ -855,6 +895,12 @@ func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requiremen
 		// and (trivially) version.
 
 		if !rootsUpgraded {
+			if cfg.BuildMod != "mod" {
+				// The only changes to the root set (if any) were to remove duplicates.
+				// The requirements are consistent (if perhaps redundant), so keep the
+				// original rs to preserve its ModuleGraph.
+				return rs, nil
+			}
 			// The root set has converged: every root going into this iteration was
 			// already at its selected version, although we have have removed other
 			// (redundant) roots for the same path.
diff --git a/src/cmd/go/internal/modload/import.go b/src/cmd/go/internal/modload/import.go
index f76befcfe35..d2bbe5cbe0b 100644
--- a/src/cmd/go/internal/modload/import.go
+++ b/src/cmd/go/internal/modload/import.go
@@ -178,11 +178,13 @@ func (e *ImportMissingSumError) Error() string {
 		// Importing package is unknown, or the missing package was named on the
 		// command line. Recommend 'go mod download' for the modules that could
 		// provide the package, since that shouldn't change go.mod.
-		args := make([]string, len(e.mods))
-		for i, mod := range e.mods {
-			args[i] = mod.Path
+		if len(e.mods) > 0 {
+			args := make([]string, len(e.mods))
+			for i, mod := range e.mods {
+				args[i] = mod.Path
+			}
+			hint = fmt.Sprintf("; to add:\n\tgo mod download %s", strings.Join(args, " "))
 		}
-		hint = fmt.Sprintf("; to add:\n\tgo mod download %s", strings.Join(args, " "))
 	} else {
 		// Importing package is known (common case). Recommend 'go get' on the
 		// current version of the importing package.
@@ -426,6 +428,15 @@ func queryImport(ctx context.Context, path string, rs *Requirements) (module.Ver
 					mv = module.ZeroPseudoVersion("v0")
 				}
 			}
+			mg, err := rs.Graph(ctx)
+			if err != nil {
+				return module.Version{}, err
+			}
+			if cmpVersion(mg.Selected(mp), mv) >= 0 {
+				// We can't resolve the import by adding mp@mv to the module graph,
+				// because the selected version of mp is already at least mv.
+				continue
+			}
 			mods = append(mods, module.Version{Path: mp, Version: mv})
 		}
 
diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index 5cdea12cd3e..d5f9d104223 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -71,7 +71,7 @@ type Root int
 const (
 	// AutoRoot is the default for most commands. modload.Init will look for
 	// a go.mod file in the current directory or any parent. If none is found,
-	// modules may be disabled (GO111MODULE=on) or commands may run in a
+	// modules may be disabled (GO111MODULE=auto) or commands may run in a
 	// limited module mode.
 	AutoRoot Root = iota
 
@@ -405,14 +405,23 @@ func loadModFile(ctx context.Context) (rs *Requirements, needCommit bool) {
 	if modRoot == "" {
 		Target = module.Version{Path: "command-line-arguments"}
 		targetPrefix = "command-line-arguments"
-		goVersion := latestGoVersion()
+		goVersion := LatestGoVersion()
 		rawGoVersion.Store(Target, goVersion)
 		requirements = newRequirements(modDepthFromGoVersion(goVersion), nil, nil)
 		return requirements, false
 	}
 
 	gomod := ModFilePath()
-	data, err := lockedfile.Read(gomod)
+	var data []byte
+	var err error
+	if gomodActual, ok := fsys.OverlayPath(gomod); ok {
+		// Don't lock go.mod if it's part of the overlay.
+		// On Plan 9, locking requires chmod, and we don't want to modify any file
+		// in the overlay. See #44700.
+		data, err = os.ReadFile(gomodActual)
+	} else {
+		data, err = lockedfile.Read(gomodActual)
+	}
 	if err != nil {
 		base.Fatalf("go: %v", err)
 	}
@@ -432,23 +441,35 @@ func loadModFile(ctx context.Context) (rs *Requirements, needCommit bool) {
 	initTarget(f.Module.Mod)
 	index = indexModFile(data, f, fixed)
 
-	if err := checkModulePathLax(f.Module.Mod.Path); err != nil {
+	if err := module.CheckImportPath(f.Module.Mod.Path); err != nil {
+		if pathErr, ok := err.(*module.InvalidPathError); ok {
+			pathErr.Kind = "module"
+		}
 		base.Fatalf("go: %v", err)
 	}
 
 	setDefaultBuildMod() // possibly enable automatic vendoring
-	rs = requirementsFromModFile(ctx)
-
+	rs = requirementsFromModFile()
 	if cfg.BuildMod == "vendor" {
 		readVendorList()
 		checkVendorConsistency()
 		rs.initVendor(vendorList)
 	}
+	if rs.hasRedundantRoot() {
+		// If any module path appears more than once in the roots, we know that the
+		// go.mod file needs to be updated even though we have not yet loaded any
+		// transitive dependencies.
+		rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
+		if err != nil {
+			base.Fatalf("go: %v", err)
+		}
+	}
+
 	if index.goVersionV == "" {
 		// TODO(#45551): Do something more principled instead of checking
 		// cfg.CmdName directly here.
 		if cfg.BuildMod == "mod" && cfg.CmdName != "mod graph" && cfg.CmdName != "mod why" {
-			addGoStmt(latestGoVersion())
+			addGoStmt(LatestGoVersion())
 			if go117EnableLazyLoading {
 				// We need to add a 'go' version to the go.mod file, but we must assume
 				// that its existing contents match something between Go 1.11 and 1.16.
@@ -492,7 +513,15 @@ func CreateModFile(ctx context.Context, modPath string) {
 		if err != nil {
 			base.Fatalf("go: %v", err)
 		}
-	} else if err := checkModulePathLax(modPath); err != nil {
+	} else if err := module.CheckImportPath(modPath); err != nil {
+		if pathErr, ok := err.(*module.InvalidPathError); ok {
+			pathErr.Kind = "module"
+			// Same as build.IsLocalPath()
+			if pathErr.Path == "." || pathErr.Path == ".." ||
+				strings.HasPrefix(pathErr.Path, "./") || strings.HasPrefix(pathErr.Path, "../") {
+				pathErr.Err = errors.New("is a local import path")
+			}
+		}
 		base.Fatalf("go: %v", err)
 	}
 
@@ -500,7 +529,7 @@ func CreateModFile(ctx context.Context, modPath string) {
 	modFile = new(modfile.File)
 	modFile.AddModuleStmt(modPath)
 	initTarget(modFile.Module.Mod)
-	addGoStmt(latestGoVersion()) // Add the go directive before converted module requirements.
+	addGoStmt(LatestGoVersion()) // Add the go directive before converted module requirements.
 
 	convertedFrom, err := convertLegacyConfig(modPath)
 	if convertedFrom != "" {
@@ -510,7 +539,12 @@ func CreateModFile(ctx context.Context, modPath string) {
 		base.Fatalf("go: %v", err)
 	}
 
-	commitRequirements(ctx, modFileGoVersion(), requirementsFromModFile(ctx))
+	rs := requirementsFromModFile()
+	rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
+	if err != nil {
+		base.Fatalf("go: %v", err)
+	}
+	commitRequirements(ctx, modFileGoVersion(), rs)
 
 	// Suggest running 'go mod tidy' unless the project is empty. Even if we
 	// imported all the correct requirements above, we're probably missing
@@ -536,49 +570,6 @@ func CreateModFile(ctx context.Context, modPath string) {
 	}
 }
 
-// checkModulePathLax checks that the path meets some minimum requirements
-// to avoid confusing users or the module cache. The requirements are weaker
-// than those of module.CheckPath to allow room for weakening module path
-// requirements in the future, but strong enough to help users avoid significant
-// problems.
-func checkModulePathLax(p string) error {
-	// TODO(matloob): Replace calls of this function in this CL with calls
-	// to module.CheckImportPath once it's been laxened, if it becomes laxened.
-	// See golang.org/issue/29101 for a discussion about whether to make CheckImportPath
-	// more lax or more strict.
-
-	errorf := func(format string, args ...interface{}) error {
-		return fmt.Errorf("invalid module path %q: %s", p, fmt.Sprintf(format, args...))
-	}
-
-	// Disallow shell characters " ' * < > ? ` | to avoid triggering bugs
-	// with file systems and subcommands. Disallow file path separators : and \
-	// because path separators other than / will confuse the module cache.
-	// See fileNameOK in golang.org/x/mod/module/module.go.
-	shellChars := "`" + `"'*<>?|`
-	fsChars := `\:`
-	if i := strings.IndexAny(p, shellChars); i >= 0 {
-		return errorf("contains disallowed shell character %q", p[i])
-	}
-	if i := strings.IndexAny(p, fsChars); i >= 0 {
-		return errorf("contains disallowed path separator character %q", p[i])
-	}
-
-	// Ensure path.IsAbs and build.IsLocalImport are false, and that the path is
-	// invariant under path.Clean, also to avoid confusing the module cache.
-	if path.IsAbs(p) {
-		return errorf("is an absolute path")
-	}
-	if build.IsLocalImport(p) {
-		return errorf("is a local import path")
-	}
-	if path.Clean(p) != p {
-		return errorf("is not clean")
-	}
-
-	return nil
-}
-
 // fixVersion returns a modfile.VersionFixer implemented using the Query function.
 //
 // It resolves commit hashes and branch names to versions,
@@ -664,9 +655,8 @@ func initTarget(m module.Version) {
 
 // requirementsFromModFile returns the set of non-excluded requirements from
 // the global modFile.
-func requirementsFromModFile(ctx context.Context) *Requirements {
+func requirementsFromModFile() *Requirements {
 	roots := make([]module.Version, 0, len(modFile.Require))
-	mPathCount := map[string]int{Target.Path: 1}
 	direct := map[string]bool{}
 	for _, r := range modFile.Require {
 		if index != nil && index.exclude[r.Mod] {
@@ -679,28 +669,12 @@ func requirementsFromModFile(ctx context.Context) *Requirements {
 		}
 
 		roots = append(roots, r.Mod)
-		mPathCount[r.Mod.Path]++
 		if !r.Indirect {
 			direct[r.Mod.Path] = true
 		}
 	}
 	module.Sort(roots)
 	rs := newRequirements(modDepthFromGoVersion(modFileGoVersion()), roots, direct)
-
-	// If any module path appears more than once in the roots, we know that the
-	// go.mod file needs to be updated even though we have not yet loaded any
-	// transitive dependencies.
-	for _, n := range mPathCount {
-		if n > 1 {
-			var err error
-			rs, err = updateRoots(ctx, rs.direct, rs, nil, nil)
-			if err != nil {
-				base.Fatalf("go: %v", err)
-			}
-			break
-		}
-	}
-
 	return rs
 }
 
@@ -712,12 +686,25 @@ func setDefaultBuildMod() {
 		return
 	}
 
-	if cfg.CmdName == "get" || strings.HasPrefix(cfg.CmdName, "mod ") {
-		// 'get' and 'go mod' commands may update go.mod automatically.
-		// TODO(jayconrod): should this narrower? Should 'go mod download' or
-		// 'go mod graph' update go.mod by default?
+	// TODO(#40775): commands should pass in the module mode as an option
+	// to modload functions instead of relying on an implicit setting
+	// based on command name.
+	switch cfg.CmdName {
+	case "get", "mod download", "mod init", "mod tidy":
+		// These commands are intended to update go.mod and go.sum.
 		cfg.BuildMod = "mod"
 		return
+	case "mod graph", "mod verify", "mod why":
+		// These commands should not update go.mod or go.sum, but they should be
+		// able to fetch modules not in go.sum and should not report errors if
+		// go.mod is inconsistent. They're useful for debugging, and they need
+		// to work in buggy situations.
+		cfg.BuildMod = "mod"
+		allowWriteGoMod = false
+		return
+	case "mod vendor":
+		cfg.BuildMod = "readonly"
+		return
 	}
 	if modRoot == "" {
 		if allowMissingModuleImports {
@@ -793,17 +780,39 @@ func addGoStmt(v string) {
 	rawGoVersion.Store(Target, v)
 }
 
-// latestGoVersion returns the latest version of the Go language supported by
+// LatestGoVersion returns the latest version of the Go language supported by
 // this toolchain, like "1.17".
-func latestGoVersion() string {
+func LatestGoVersion() string {
 	tags := build.Default.ReleaseTags
 	version := tags[len(tags)-1]
 	if !strings.HasPrefix(version, "go") || !modfile.GoVersionRE.MatchString(version[2:]) {
-		base.Fatalf("go: unrecognized default version %q", version)
+		base.Fatalf("go: internal error: unrecognized default version %q", version)
 	}
 	return version[2:]
 }
 
+// priorGoVersion returns the Go major release immediately preceding v,
+// or v itself if v is the first Go major release (1.0) or not a supported
+// Go version.
+func priorGoVersion(v string) string {
+	vTag := "go" + v
+	tags := build.Default.ReleaseTags
+	for i, tag := range tags {
+		if tag == vTag {
+			if i == 0 {
+				return v
+			}
+
+			version := tags[i-1]
+			if !strings.HasPrefix(version, "go") || !modfile.GoVersionRE.MatchString(version[2:]) {
+				base.Fatalf("go: internal error: unrecognized version %q", version)
+			}
+			return version[2:]
+		}
+	}
+	return v
+}
+
 var altConfigs = []string{
 	"Gopkg.lock",
 
@@ -918,14 +927,8 @@ func findModulePath(dir string) (string, error) {
 		}
 		if rel := search.InDir(dir, filepath.Join(gpdir, "src")); rel != "" && rel != "." {
 			path := filepath.ToSlash(rel)
-			// TODO(matloob): replace this with module.CheckImportPath
-			// once it's been laxened.
-			// Only checkModulePathLax here. There are some unpublishable
-			// module names that are compatible with checkModulePathLax
-			// but they already work in GOPATH so don't break users
-			// trying to do a build with modules. gorelease will alert users
-			// publishing their modules to fix their paths.
-			if err := checkModulePathLax(path); err != nil {
+			// gorelease will alert users publishing their modules to fix their paths.
+			if err := module.CheckImportPath(path); err != nil {
 				badPathErr = err
 				break
 			}
@@ -1015,10 +1018,14 @@ func commitRequirements(ctx context.Context, goVersion string, rs *Requirements)
 			Indirect: !rs.direct[m.Path],
 		})
 	}
-	modFile.SetRequire(list)
 	if goVersion != "" {
 		modFile.AddGoStmt(goVersion)
 	}
+	if semver.Compare("v"+modFileGoVersion(), separateIndirectVersionV) < 0 {
+		modFile.SetRequire(list)
+	} else {
+		modFile.SetRequireSeparateIndirect(list)
+	}
 	modFile.Cleanup()
 
 	dirty := index.modFileIsDirty(modFile)
@@ -1038,6 +1045,13 @@ func commitRequirements(ctx context.Context, goVersion string, rs *Requirements)
 		}
 		return
 	}
+	gomod := ModFilePath()
+	if _, ok := fsys.OverlayPath(gomod); ok {
+		if dirty {
+			base.Fatalf("go: updates to go.mod needed, but go.mod is part of the overlay specified with -overlay")
+		}
+		return
+	}
 
 	new, err := modFile.Format()
 	if err != nil {
@@ -1138,12 +1152,11 @@ func keepSums(ctx context.Context, ld *loader, rs *Requirements, which whichSums
 		}
 	}
 
-	if rs.depth == lazy && rs.graph.Load() == nil {
-		// The main module is lazy and we haven't needed to load the module graph so
-		// far. Don't incur the cost of loading it now — since we haven't loaded the
-		// graph, we probably don't have any checksums to contribute to the distant
-		// parts of the graph anyway. Instead, just request sums for the roots that
-		// we know about.
+	if rs.graph.Load() == nil {
+		// The module graph was not loaded, possibly because the main module is lazy
+		// or possibly because we haven't needed to load the graph yet.
+		// Save sums for the root modules (or their replacements), but don't
+		// incur the cost of loading the graph just to find and retain the sums.
 		for _, m := range rs.rootModules {
 			r := resolveReplacement(m)
 			keep[modkey(r)] = true
diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index f30ac6e0c8b..b54f670812f 100644
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -118,7 +118,7 @@ import (
 	"cmd/go/internal/mvs"
 	"cmd/go/internal/par"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 	"golang.org/x/mod/semver"
@@ -152,6 +152,13 @@ type PackageOpts struct {
 	// packages.
 	Tidy bool
 
+	// TidyCompatibleVersion is the oldest Go version that must be able to
+	// reproducibly reload the requested packages.
+	//
+	// If empty, the compatible version is the Go version immediately prior to the
+	// 'go' version listed in the go.mod file.
+	TidyCompatibleVersion string
+
 	// VendorModulesInGOROOTSrc indicates that if we are within a module in
 	// GOROOT/src, packages in the module's vendor directory should be resolved as
 	// actual module dependencies (instead of standard-library packages).
@@ -164,6 +171,11 @@ type PackageOpts struct {
 	// if the flag is set to "readonly" (the default) or "vendor".
 	ResolveMissingImports bool
 
+	// AssumeRootsImported indicates that the transitive dependencies of the root
+	// packages should be treated as if those roots will be imported by the main
+	// module.
+	AssumeRootsImported bool
+
 	// AllowPackage, if non-nil, is called after identifying the module providing
 	// each package. If AllowPackage returns a non-nil error, that error is set
 	// for the package, and the imports and test of that package will not be
@@ -314,10 +326,6 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 
 	initialRS, _ := loadModFile(ctx) // Ignore needCommit — we're going to commit at the end regardless.
 
-	if opts.GoVersion == "" {
-		opts.GoVersion = modFileGoVersion()
-	}
-
 	ld := loadFromRoots(ctx, loaderParams{
 		PackageOpts:  opts,
 		requirements: initialRS,
@@ -375,12 +383,31 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 			}
 		}
 
-		modfetch.TrimGoSum(keepSums(ctx, ld, ld.requirements, loadedZipSumsOnly))
+		keep := keepSums(ctx, ld, ld.requirements, loadedZipSumsOnly)
+		if compatDepth := modDepthFromGoVersion(ld.TidyCompatibleVersion); compatDepth != ld.requirements.depth {
+			compatRS := newRequirements(compatDepth, ld.requirements.rootModules, ld.requirements.direct)
+			ld.checkTidyCompatibility(ctx, compatRS)
+
+			for m := range keepSums(ctx, ld, compatRS, loadedZipSumsOnly) {
+				keep[m] = true
+			}
+		}
+
+		if allowWriteGoMod {
+			modfetch.TrimGoSum(keep)
+
+			// commitRequirements below will also call WriteGoSum, but the "keep" map
+			// we have here could be strictly larger: commitRequirements only commits
+			// loaded.requirements, but here we may have also loaded (and want to
+			// preserve checksums for) additional entities from compatRS, which are
+			// only needed for compatibility with ld.TidyCompatibleVersion.
+			modfetch.WriteGoSum(keep)
+		}
 	}
 
 	// Success! Update go.mod and go.sum (if needed) and return the results.
 	loaded = ld
-	commitRequirements(ctx, opts.GoVersion, loaded.requirements)
+	commitRequirements(ctx, loaded.GoVersion, loaded.requirements)
 
 	for _, pkg := range ld.pkgs {
 		if !pkg.isTest() {
@@ -605,10 +632,8 @@ func ImportFromFiles(ctx context.Context, gofiles []string) {
 		base.Fatalf("go: %v", err)
 	}
 
-	goVersion := modFileGoVersion()
 	loaded = loadFromRoots(ctx, loaderParams{
 		PackageOpts: PackageOpts{
-			GoVersion:             goVersion,
 			Tags:                  tags,
 			ResolveMissingImports: true,
 			SilencePackageErrors:  true,
@@ -620,7 +645,7 @@ func ImportFromFiles(ctx context.Context, gofiles []string) {
 			return roots
 		},
 	})
-	commitRequirements(ctx, goVersion, loaded.requirements)
+	commitRequirements(ctx, loaded.GoVersion, loaded.requirements)
 }
 
 // DirImportPath returns the effective import path for dir,
@@ -650,20 +675,6 @@ func DirImportPath(ctx context.Context, dir string) string {
 	return "."
 }
 
-// TargetPackages returns the list of packages in the target (top-level) module
-// matching pattern, which may be relative to the working directory, under all
-// build tag settings.
-func TargetPackages(ctx context.Context, pattern string) *search.Match {
-	// TargetPackages is relative to the main module, so ensure that the main
-	// module is a thing that can contain packages.
-	LoadModFile(ctx) // Sets Target.
-	ModRoot()        // Emits an error if Target cannot contain packages.
-
-	m := search.NewMatch(pattern)
-	matchPackages(ctx, m, imports.AnyTags(), omitStd, []module.Version{Target})
-	return m
-}
-
 // ImportMap returns the actual package import path
 // for an import path found in source code.
 // If the given import path does not appear in the source code
@@ -695,29 +706,6 @@ func PackageModule(path string) module.Version {
 	return pkg.mod
 }
 
-// PackageImports returns the imports for the package named by the import path.
-// Test imports will be returned as well if tests were loaded for the package
-// (i.e., if "all" was loaded or if LoadTests was set and the path was matched
-// by a command line argument). PackageImports will return nil for
-// unknown package paths.
-func PackageImports(path string) (imports, testImports []string) {
-	pkg, ok := loaded.pkgCache.Get(path).(*loadPkg)
-	if !ok {
-		return nil, nil
-	}
-	imports = make([]string, len(pkg.imports))
-	for i, p := range pkg.imports {
-		imports[i] = p.path
-	}
-	if pkg.test != nil {
-		testImports = make([]string, len(pkg.test.imports))
-		for i, p := range pkg.test.imports {
-			testImports[i] = p.path
-		}
-	}
-	return imports, testImports
-}
-
 // Lookup returns the source directory, import path, and any loading error for
 // the package at path as imported from the package in parentDir.
 // Lookup requires that one of the Load functions in this package has already
@@ -855,6 +843,11 @@ const (
 	// are also roots (and must be marked pkgIsRoot).
 	pkgIsRoot
 
+	// pkgFromRoot indicates that the package is in the transitive closure of
+	// imports starting at the roots. (Note that every package marked as pkgIsRoot
+	// is also trivially marked pkgFromRoot.)
+	pkgFromRoot
+
 	// pkgImportsLoaded indicates that the imports and testImports fields of a
 	// loadPkg have been populated.
 	pkgImportsLoaded
@@ -921,22 +914,38 @@ func loadFromRoots(ctx context.Context, params loaderParams) *loader {
 		work:         par.NewQueue(runtime.GOMAXPROCS(0)),
 	}
 
-	if params.GoVersion != "" {
-		if semver.Compare("v"+params.GoVersion, narrowAllVersionV) < 0 && !ld.UseVendorAll {
-			// The module's go version explicitly predates the change in "all" for lazy
-			// loading, so continue to use the older interpretation.
-			// (If params.GoVersion is empty, we are probably not in any module at all
-			// and should use the latest semantics.)
-			ld.allClosesOverTests = true
-		}
+	if ld.GoVersion == "" {
+		ld.GoVersion = modFileGoVersion()
 
-		var err error
-		ld.requirements, err = convertDepth(ctx, ld.requirements, modDepthFromGoVersion(params.GoVersion))
-		if err != nil {
-			ld.errorf("go: %v\n", err)
+		if ld.Tidy && semver.Compare("v"+ld.GoVersion, "v"+LatestGoVersion()) > 0 {
+			ld.errorf("go mod tidy: go.mod file indicates go %s, but maximum supported version is %s\n", ld.GoVersion, LatestGoVersion())
+			base.ExitIfErrors()
 		}
 	}
 
+	if ld.Tidy {
+		if ld.TidyCompatibleVersion == "" {
+			ld.TidyCompatibleVersion = priorGoVersion(ld.GoVersion)
+		} else if semver.Compare("v"+ld.TidyCompatibleVersion, "v"+ld.GoVersion) > 0 {
+			// Each version of the Go toolchain knows how to interpret go.mod and
+			// go.sum files produced by all previous versions, so a compatibility
+			// version higher than the go.mod version adds nothing.
+			ld.TidyCompatibleVersion = ld.GoVersion
+		}
+	}
+
+	if semver.Compare("v"+ld.GoVersion, narrowAllVersionV) < 0 && !ld.UseVendorAll {
+		// The module's go version explicitly predates the change in "all" for lazy
+		// loading, so continue to use the older interpretation.
+		ld.allClosesOverTests = true
+	}
+
+	var err error
+	ld.requirements, err = convertDepth(ctx, ld.requirements, modDepthFromGoVersion(ld.GoVersion))
+	if err != nil {
+		ld.errorf("go: %v\n", err)
+	}
+
 	if ld.requirements.depth == eager {
 		var err error
 		ld.requirements, _, err = expandGraph(ctx, ld.requirements)
@@ -1032,7 +1041,7 @@ func loadFromRoots(ctx context.Context, params loaderParams) *loader {
 		// iteration so we don't need to also update it here. (That would waste time
 		// computing a "direct" map that we'll have to recompute later anyway.)
 		direct := ld.requirements.direct
-		rs, err := updateRoots(ctx, direct, ld.requirements, noPkgs, toAdd)
+		rs, err := updateRoots(ctx, direct, ld.requirements, noPkgs, toAdd, ld.AssumeRootsImported)
 		if err != nil {
 			// If an error was found in a newly added module, report the package
 			// import stack instead of the module requirement stack. Packages
@@ -1073,7 +1082,7 @@ func loadFromRoots(ctx context.Context, params loaderParams) *loader {
 			// If that is not the case, there is a bug in the loading loop above.
 			for _, m := range rs.rootModules {
 				if v, ok := ld.requirements.rootSelected(m.Path); !ok || v != m.Version {
-					ld.errorf("go: internal error: a requirement on %v is needed but was not added during package loading\n", m)
+					ld.errorf("go mod tidy: internal error: a requirement on %v is needed but was not added during package loading\n", m)
 					base.ExitIfErrors()
 				}
 			}
@@ -1238,7 +1247,7 @@ func (ld *loader) updateRequirements(ctx context.Context) (changed bool, err err
 		addRoots = tidy.rootModules
 	}
 
-	rs, err = updateRoots(ctx, direct, rs, ld.pkgs, addRoots)
+	rs, err = updateRoots(ctx, direct, rs, ld.pkgs, addRoots, ld.AssumeRootsImported)
 	if err != nil {
 		// We don't actually know what even the root requirements are supposed to be,
 		// so we can't proceed with loading. Return the error to the caller
@@ -1397,6 +1406,9 @@ func (ld *loader) applyPkgFlags(ctx context.Context, pkg *loadPkg, flags loadPkg
 		// This package matches a root pattern by virtue of being in "all".
 		flags |= pkgIsRoot
 	}
+	if flags.has(pkgIsRoot) {
+		flags |= pkgFromRoot
+	}
 
 	old := pkg.flags.update(flags)
 	new := old | flags
@@ -1451,6 +1463,12 @@ func (ld *loader) applyPkgFlags(ctx context.Context, pkg *loadPkg, flags loadPkg
 			ld.applyPkgFlags(ctx, dep, pkgInAll)
 		}
 	}
+
+	if new.has(pkgFromRoot) && !old.has(pkgFromRoot|pkgImportsLoaded) {
+		for _, dep := range pkg.imports {
+			ld.applyPkgFlags(ctx, dep, pkgFromRoot)
+		}
+	}
 }
 
 // preloadRootModules loads the module requirements needed to identify the
@@ -1513,7 +1531,7 @@ func (ld *loader) preloadRootModules(ctx context.Context, rootPkgs []string) (ch
 	}
 	module.Sort(toAdd)
 
-	rs, err := updateRoots(ctx, ld.requirements.direct, ld.requirements, nil, toAdd)
+	rs, err := updateRoots(ctx, ld.requirements.direct, ld.requirements, nil, toAdd, ld.AssumeRootsImported)
 	if err != nil {
 		// We are missing some root dependency, and for some reason we can't load
 		// enough of the module dependency graph to add the missing root. Package
@@ -1744,6 +1762,219 @@ func (ld *loader) checkMultiplePaths() {
 	}
 }
 
+// checkTidyCompatibility emits an error if any package would be loaded from a
+// different module under rs than under ld.requirements.
+func (ld *loader) checkTidyCompatibility(ctx context.Context, rs *Requirements) {
+	suggestUpgrade := false
+	suggestEFlag := false
+	suggestFixes := func() {
+		if ld.AllowErrors {
+			// The user is explicitly ignoring these errors, so don't bother them with
+			// other options.
+			return
+		}
+
+		// We print directly to os.Stderr because this information is advice about
+		// how to fix errors, not actually an error itself.
+		// (The actual errors should have been logged already.)
+
+		fmt.Fprintln(os.Stderr)
+
+		goFlag := ""
+		if ld.GoVersion != modFileGoVersion() {
+			goFlag = " -go=" + ld.GoVersion
+		}
+
+		compatFlag := ""
+		if ld.TidyCompatibleVersion != priorGoVersion(ld.GoVersion) {
+			compatFlag = " -compat=" + ld.TidyCompatibleVersion
+		}
+		if suggestUpgrade {
+			eDesc := ""
+			eFlag := ""
+			if suggestEFlag {
+				eDesc = ", leaving some packages unresolved"
+				eFlag = " -e"
+			}
+			fmt.Fprintf(os.Stderr, "To upgrade to the versions selected by go %s%s:\n\tgo mod tidy%s -go=%s && go mod tidy%s -go=%s%s\n", ld.TidyCompatibleVersion, eDesc, eFlag, ld.TidyCompatibleVersion, eFlag, ld.GoVersion, compatFlag)
+		} else if suggestEFlag {
+			// If some packages are missing but no package is upgraded, then we
+			// shouldn't suggest upgrading to the Go 1.16 versions explicitly — that
+			// wouldn't actually fix anything for Go 1.16 users, and *would* break
+			// something for Go 1.17 users.
+			fmt.Fprintf(os.Stderr, "To proceed despite packages unresolved in go %s:\n\tgo mod tidy -e%s%s\n", ld.TidyCompatibleVersion, goFlag, compatFlag)
+		}
+
+		fmt.Fprintf(os.Stderr, "If reproducibility with go %s is not needed:\n\tgo mod tidy%s -compat=%s\n", ld.TidyCompatibleVersion, goFlag, ld.GoVersion)
+
+		// TODO(#46141): Populate the linked wiki page.
+		fmt.Fprintf(os.Stderr, "For other options, see:\n\thttps://golang.org/doc/modules/pruning\n")
+	}
+
+	mg, err := rs.Graph(ctx)
+	if err != nil {
+		ld.errorf("go mod tidy: error loading go %s module graph: %v\n", ld.TidyCompatibleVersion, err)
+		suggestFixes()
+		return
+	}
+
+	// Re-resolve packages in parallel.
+	//
+	// We re-resolve each package — rather than just checking versions — to ensure
+	// that we have fetched module source code (and, importantly, checksums for
+	// that source code) for all modules that are necessary to ensure that imports
+	// are unambiguous. That also produces clearer diagnostics, since we can say
+	// exactly what happened to the package if it became ambiguous or disappeared
+	// entirely.
+	//
+	// We re-resolve the packages in parallel because this process involves disk
+	// I/O to check for package sources, and because the process of checking for
+	// ambiguous imports may require us to download additional modules that are
+	// otherwise pruned out in Go 1.17 — we don't want to block progress on other
+	// packages while we wait for a single new download.
+	type mismatch struct {
+		mod module.Version
+		err error
+	}
+	mismatchMu := make(chan map[*loadPkg]mismatch, 1)
+	mismatchMu <- map[*loadPkg]mismatch{}
+	for _, pkg := range ld.pkgs {
+		if pkg.mod.Path == "" && pkg.err == nil {
+			// This package is from the standard library (which does not vary based on
+			// the module graph).
+			continue
+		}
+
+		pkg := pkg
+		ld.work.Add(func() {
+			mod, _, err := importFromModules(ctx, pkg.path, rs, mg)
+			if mod != pkg.mod {
+				mismatches := <-mismatchMu
+				mismatches[pkg] = mismatch{mod: mod, err: err}
+				mismatchMu <- mismatches
+			}
+		})
+	}
+	<-ld.work.Idle()
+
+	mismatches := <-mismatchMu
+	if len(mismatches) == 0 {
+		// Since we're running as part of 'go mod tidy', the roots of the module
+		// graph should contain only modules that are relevant to some package in
+		// the package graph. We checked every package in the package graph and
+		// didn't find any mismatches, so that must mean that all of the roots of
+		// the module graph are also consistent.
+		//
+		// If we're wrong, Go 1.16 in -mod=readonly mode will error out with
+		// "updates to go.mod needed", which would be very confusing. So instead,
+		// we'll double-check that our reasoning above actually holds — if it
+		// doesn't, we'll emit an internal error and hopefully the user will report
+		// it as a bug.
+		for _, m := range ld.requirements.rootModules {
+			if v := mg.Selected(m.Path); v != m.Version {
+				fmt.Fprintln(os.Stderr)
+				base.Fatalf("go: internal error: failed to diagnose selected-version mismatch for module %s: go %s selects %s, but go %s selects %s\n\tPlease report this at https://golang.org/issue.", m.Path, ld.GoVersion, m.Version, ld.TidyCompatibleVersion, v)
+			}
+		}
+		return
+	}
+
+	// Iterate over the packages (instead of the mismatches map) to emit errors in
+	// deterministic order.
+	for _, pkg := range ld.pkgs {
+		mismatch, ok := mismatches[pkg]
+		if !ok {
+			continue
+		}
+
+		if pkg.isTest() {
+			// We already did (or will) report an error for the package itself,
+			// so don't report a duplicate (and more vebose) error for its test.
+			if _, ok := mismatches[pkg.testOf]; !ok {
+				base.Fatalf("go: internal error: mismatch recorded for test %s, but not its non-test package", pkg.path)
+			}
+			continue
+		}
+
+		switch {
+		case mismatch.err != nil:
+			// pkg resolved successfully, but errors out using the requirements in rs.
+			//
+			// This could occur because the import is provided by a single lazy root
+			// (and is thus unambiguous in lazy mode) and also one or more
+			// transitive dependencies (and is ambiguous in eager mode).
+			//
+			// It could also occur because some transitive dependency upgrades the
+			// module that previously provided the package to a version that no
+			// longer does, or to a version for which the module source code (but
+			// not the go.mod file in isolation) has a checksum error.
+			if missing := (*ImportMissingError)(nil); errors.As(mismatch.err, &missing) {
+				selected := module.Version{
+					Path:    pkg.mod.Path,
+					Version: mg.Selected(pkg.mod.Path),
+				}
+				ld.errorf("%s loaded from %v,\n\tbut go %s would fail to locate it in %s\n", pkg.stackText(), pkg.mod, ld.TidyCompatibleVersion, selected)
+			} else {
+				if ambiguous := (*AmbiguousImportError)(nil); errors.As(mismatch.err, &ambiguous) {
+					// TODO: Is this check needed?
+				}
+				ld.errorf("%s loaded from %v,\n\tbut go %s would fail to locate it:\n\t%v\n", pkg.stackText(), pkg.mod, ld.TidyCompatibleVersion, mismatch.err)
+			}
+
+			suggestEFlag = true
+
+			// Even if we press ahead with the '-e' flag, the older version will
+			// error out in readonly mode if it thinks the go.mod file contains
+			// any *explicit* dependency that is not at its selected version,
+			// even if that dependency is not relevant to any package being loaded.
+			//
+			// We check for that condition here. If all of the roots are consistent
+			// the '-e' flag suffices, but otherwise we need to suggest an upgrade.
+			if !suggestUpgrade {
+				for _, m := range ld.requirements.rootModules {
+					if v := mg.Selected(m.Path); v != m.Version {
+						suggestUpgrade = true
+						break
+					}
+				}
+			}
+
+		case pkg.err != nil:
+			// pkg had an error in lazy mode (presumably suppressed with the -e flag),
+			// but not in eager mode.
+			//
+			// This is possible, if, say, the import is unresolved in lazy mode
+			// (because the "latest" version of each candidate module either is
+			// unavailable or does not contain the package), but is resolved in
+			// eager mode due to a newer-than-latest dependency that is normally
+			// runed out of the module graph.
+			//
+			// This could also occur if the source code for the module providing the
+			// package in lazy mode has a checksum error, but eager mode upgrades
+			// that module to a version with a correct checksum.
+			//
+			// pkg.err should have already been logged elsewhere — along with a
+			// stack trace — so log only the import path and non-error info here.
+			suggestUpgrade = true
+			ld.errorf("%s failed to load from any module,\n\tbut go %s would load it from %v\n", pkg.path, ld.TidyCompatibleVersion, mismatch.mod)
+
+		case pkg.mod != mismatch.mod:
+			// The package is loaded successfully by both Go versions, but from a
+			// different module in each. This could lead to subtle (and perhaps even
+			// unnoticed!) variations in behavior between builds with different
+			// toolchains.
+			suggestUpgrade = true
+			ld.errorf("%s loaded from %v,\n\tbut go %s would select %v\n", pkg.stackText(), pkg.mod, ld.TidyCompatibleVersion, mismatch.mod.Version)
+
+		default:
+			base.Fatalf("go: internal error: mismatch recorded for package %s, but no differences found", pkg.path)
+		}
+	}
+
+	suggestFixes()
+	base.ExitIfErrors()
+}
+
 // scanDir is like imports.ScanDir but elides known magic imports from the list,
 // so that we do not go looking for packages that don't really exist.
 //
diff --git a/src/cmd/go/internal/modload/modfile.go b/src/cmd/go/internal/modload/modfile.go
index bafff3e080e..03e02e73b63 100644
--- a/src/cmd/go/internal/modload/modfile.go
+++ b/src/cmd/go/internal/modload/modfile.go
@@ -8,6 +8,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -15,6 +16,7 @@ import (
 
 	"cmd/go/internal/base"
 	"cmd/go/internal/cfg"
+	"cmd/go/internal/fsys"
 	"cmd/go/internal/lockedfile"
 	"cmd/go/internal/modfetch"
 	"cmd/go/internal/par"
@@ -35,6 +37,11 @@ const (
 	// module's go.mod file is expected to list explicit requirements on every
 	// module that provides any package transitively imported by that module.
 	lazyLoadingVersionV = "v1.17"
+
+	// separateIndirectVersionV is the Go version (plus leading "v") at which
+	// "// indirect" dependencies are added in a block separate from the direct
+	// ones. See https://golang.org/issue/45965.
+	separateIndirectVersionV = "v1.17"
 )
 
 const (
@@ -55,7 +62,7 @@ var modFile *modfile.File
 // in modFile are intepreted, or the latest Go version if modFile is nil.
 func modFileGoVersion() string {
 	if modFile == nil {
-		return latestGoVersion()
+		return LatestGoVersion()
 	}
 	if modFile.Go == nil || modFile.Go.Version == "" {
 		// The main module necessarily has a go.mod file, and that file lacks a
@@ -588,39 +595,14 @@ func rawGoModSummary(m module.Version) (*modFileSummary, error) {
 	}
 	c := rawGoModSummaryCache.Do(m, func() interface{} {
 		summary := new(modFileSummary)
-		var f *modfile.File
-		if m.Version == "" {
-			// m is a replacement module with only a file path.
-			dir := m.Path
-			if !filepath.IsAbs(dir) {
-				dir = filepath.Join(ModRoot(), dir)
-			}
-			gomod := filepath.Join(dir, "go.mod")
-
-			data, err := lockedfile.Read(gomod)
-			if err != nil {
-				return cached{nil, module.VersionError(m, fmt.Errorf("reading %s: %v", base.ShortPath(gomod), err))}
-			}
-			f, err = modfile.ParseLax(gomod, data, nil)
-			if err != nil {
-				return cached{nil, module.VersionError(m, fmt.Errorf("parsing %s: %v", base.ShortPath(gomod), err))}
-			}
-		} else {
-			if !semver.IsValid(m.Version) {
-				// Disallow the broader queries supported by fetch.Lookup.
-				base.Fatalf("go: internal error: %s@%s: unexpected invalid semantic version", m.Path, m.Version)
-			}
-
-			data, err := modfetch.GoMod(m.Path, m.Version)
-			if err != nil {
-				return cached{nil, err}
-			}
-			f, err = modfile.ParseLax("go.mod", data, nil)
-			if err != nil {
-				return cached{nil, module.VersionError(m, fmt.Errorf("parsing go.mod: %v", err))}
-			}
+		name, data, err := rawGoModData(m)
+		if err != nil {
+			return cached{nil, err}
+		}
+		f, err := modfile.ParseLax(name, data, nil)
+		if err != nil {
+			return cached{nil, module.VersionError(m, fmt.Errorf("parsing %s: %v", base.ShortPath(name), err))}
 		}
-
 		if f.Module != nil {
 			summary.module = f.Module.Mod
 			summary.deprecated = f.Module.Deprecated
@@ -656,6 +638,43 @@ func rawGoModSummary(m module.Version) (*modFileSummary, error) {
 
 var rawGoModSummaryCache par.Cache // module.Version → rawGoModSummary result
 
+// rawGoModData returns the content of the go.mod file for module m, ignoring
+// all replacements that may apply to m.
+//
+// rawGoModData cannot be used on the Target module.
+//
+// Unlike rawGoModSummary, rawGoModData does not cache its results in memory.
+// Use rawGoModSummary instead unless you specifically need these bytes.
+func rawGoModData(m module.Version) (name string, data []byte, err error) {
+	if m.Version == "" {
+		// m is a replacement module with only a file path.
+		dir := m.Path
+		if !filepath.IsAbs(dir) {
+			dir = filepath.Join(ModRoot(), dir)
+		}
+		name = filepath.Join(dir, "go.mod")
+		if gomodActual, ok := fsys.OverlayPath(name); ok {
+			// Don't lock go.mod if it's part of the overlay.
+			// On Plan 9, locking requires chmod, and we don't want to modify any file
+			// in the overlay. See #44700.
+			data, err = os.ReadFile(gomodActual)
+		} else {
+			data, err = lockedfile.Read(gomodActual)
+		}
+		if err != nil {
+			return "", nil, module.VersionError(m, fmt.Errorf("reading %s: %v", base.ShortPath(name), err))
+		}
+	} else {
+		if !semver.IsValid(m.Version) {
+			// Disallow the broader queries supported by fetch.Lookup.
+			base.Fatalf("go: internal error: %s@%s: unexpected invalid semantic version", m.Path, m.Version)
+		}
+		name = "go.mod"
+		data, err = modfetch.GoMod(m.Path, m.Version)
+	}
+	return name, data, err
+}
+
 // queryLatestVersionIgnoringRetractions looks up the latest version of the
 // module with the given path without considering retracted or excluded
 // versions.
diff --git a/src/cmd/go/internal/modload/query.go b/src/cmd/go/internal/modload/query.go
index 6f6c6e8c98d..d4c906a8739 100644
--- a/src/cmd/go/internal/modload/query.go
+++ b/src/cmd/go/internal/modload/query.go
@@ -5,13 +5,13 @@
 package modload
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
 	"io/fs"
 	"os"
 	pathpkg "path"
-	"path/filepath"
 	"sort"
 	"strings"
 	"sync"
@@ -21,8 +21,8 @@ import (
 	"cmd/go/internal/imports"
 	"cmd/go/internal/modfetch"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
 	"cmd/go/internal/trace"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 	"golang.org/x/mod/semver"
@@ -920,8 +920,8 @@ func (e *PackageNotInModuleError) ImportPath() string {
 	return ""
 }
 
-// ModuleHasRootPackage returns whether module m contains a package m.Path.
-func ModuleHasRootPackage(ctx context.Context, m module.Version) (bool, error) {
+// moduleHasRootPackage returns whether module m contains a package m.Path.
+func moduleHasRootPackage(ctx context.Context, m module.Version) (bool, error) {
 	needSum := false
 	root, isLocal, err := fetch(ctx, m, needSum)
 	if err != nil {
@@ -931,14 +931,32 @@ func ModuleHasRootPackage(ctx context.Context, m module.Version) (bool, error) {
 	return ok, err
 }
 
-func versionHasGoMod(ctx context.Context, m module.Version) (bool, error) {
-	needSum := false
-	root, _, err := fetch(ctx, m, needSum)
+// versionHasGoMod returns whether a version has a go.mod file.
+//
+// versionHasGoMod fetches the go.mod file (possibly a fake) and true if it
+// contains anything other than a module directive with the same path. When a
+// module does not have a real go.mod file, the go command acts as if it had one
+// that only contained a module directive. Normal go.mod files created after
+// 1.12 at least have a go directive.
+//
+// This function is a heuristic, since it's possible to commit a file that would
+// pass this test. However, we only need a heurstic for determining whether
+// +incompatible versions may be "latest", which is what this function is used
+// for.
+//
+// This heuristic is useful for two reasons: first, when using a proxy,
+// this lets us fetch from the .mod endpoint which is much faster than the .zip
+// endpoint. The .mod file is used anyway, even if the .zip file contains a
+// go.mod with different content. Second, if we don't fetch the .zip, then
+// we don't need to verify it in go.sum. This makes 'go list -m -u' faster
+// and simpler.
+func versionHasGoMod(_ context.Context, m module.Version) (bool, error) {
+	_, data, err := rawGoModData(m)
 	if err != nil {
 		return false, err
 	}
-	fi, err := os.Stat(filepath.Join(root, "go.mod"))
-	return err == nil && !fi.IsDir(), nil
+	isFake := bytes.Equal(data, modfetch.LegacyGoMod(m.Path))
+	return !isFake, nil
 }
 
 // A versionRepo is a subset of modfetch.Repo that can report information about
diff --git a/src/cmd/go/internal/run/run.go b/src/cmd/go/internal/run/run.go
index 784f7162dfd..9e9e49ec898 100644
--- a/src/cmd/go/internal/run/run.go
+++ b/src/cmd/go/internal/run/run.go
@@ -18,8 +18,8 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
 	"cmd/go/internal/work"
+	"cmd/internal/str"
 )
 
 var CmdRun = &base.Command{
diff --git a/src/cmd/go/internal/test/test.go b/src/cmd/go/internal/test/test.go
index 59ea1ef5445..aeba80eb680 100644
--- a/src/cmd/go/internal/test/test.go
+++ b/src/cmd/go/internal/test/test.go
@@ -30,9 +30,9 @@ import (
 	"cmd/go/internal/load"
 	"cmd/go/internal/lockedfile"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
 	"cmd/go/internal/trace"
 	"cmd/go/internal/work"
+	"cmd/internal/str"
 	"cmd/internal/test2json"
 )
 
diff --git a/src/cmd/go/internal/vcs/vcs.go b/src/cmd/go/internal/vcs/vcs.go
index 91485f6f745..97b2a631ae6 100644
--- a/src/cmd/go/internal/vcs/vcs.go
+++ b/src/cmd/go/internal/vcs/vcs.go
@@ -23,8 +23,8 @@ import (
 	"cmd/go/internal/base"
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/search"
-	"cmd/go/internal/str"
 	"cmd/go/internal/web"
+	"cmd/internal/str"
 
 	"golang.org/x/mod/module"
 )
diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go
index 1babbda8899..0ed2389cd5a 100644
--- a/src/cmd/go/internal/work/build.go
+++ b/src/cmd/go/internal/work/build.go
@@ -128,8 +128,8 @@ and test commands:
 		a build will run as if the disk file path exists with the contents
 		given by the backing file paths, or as if the disk file path does not
 		exist if its backing file path is empty. Support for the -overlay flag
-		has some limitations:importantly, cgo files included from outside the
-		include path must be  in the same directory as the Go package they are
+		has some limitations: importantly, cgo files included from outside the
+		include path must be in the same directory as the Go package they are
 		included from, and overlays will not appear when binaries and tests are
 		run through go run and go test respectively.
 	-pkgdir dir
diff --git a/src/cmd/go/internal/work/buildid.go b/src/cmd/go/internal/work/buildid.go
index 4e9189a3632..15f944d2af2 100644
--- a/src/cmd/go/internal/work/buildid.go
+++ b/src/cmd/go/internal/work/buildid.go
@@ -15,8 +15,8 @@ import (
 	"cmd/go/internal/cache"
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/fsys"
-	"cmd/go/internal/str"
 	"cmd/internal/buildid"
+	"cmd/internal/str"
 )
 
 // Build IDs
diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go
index b506b836561..2aa099bf171 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -34,8 +34,8 @@ import (
 	"cmd/go/internal/fsys"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
-	"cmd/go/internal/str"
 	"cmd/go/internal/trace"
+	"cmd/internal/str"
 )
 
 // actionList returns the list of actions in the dag rooted at root
@@ -252,8 +252,15 @@ func (b *Builder) buildActionID(a *Action) cache.ActionID {
 
 		ccExe := b.ccExe()
 		fmt.Fprintf(h, "CC=%q %q %q %q\n", ccExe, cppflags, cflags, ldflags)
-		if ccID, err := b.gccToolID(ccExe[0], "c"); err == nil {
-			fmt.Fprintf(h, "CC ID=%q\n", ccID)
+		// Include the C compiler tool ID so that if the C
+		// compiler changes we rebuild the package.
+		// But don't do that for standard library packages like net,
+		// so that the prebuilt .a files from a Go binary install
+		// don't need to be rebuilt with the local compiler.
+		if !p.Standard {
+			if ccID, err := b.gccToolID(ccExe[0], "c"); err == nil {
+				fmt.Fprintf(h, "CC ID=%q\n", ccID)
+			}
 		}
 		if len(p.CXXFiles)+len(p.SwigCXXFiles) > 0 {
 			cxxExe := b.cxxExe()
diff --git a/src/cmd/go/internal/work/gc.go b/src/cmd/go/internal/work/gc.go
index 85da4f89f99..70ca5d69f83 100644
--- a/src/cmd/go/internal/work/gc.go
+++ b/src/cmd/go/internal/work/gc.go
@@ -20,8 +20,8 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/fsys"
 	"cmd/go/internal/load"
-	"cmd/go/internal/str"
 	"cmd/internal/objabi"
+	"cmd/internal/str"
 	"cmd/internal/sys"
 	"crypto/sha1"
 )
@@ -29,6 +29,18 @@ import (
 // The 'path' used for GOROOT_FINAL when -trimpath is specified
 const trimPathGoRootFinal = "go"
 
+var runtimePackages = map[string]struct{}{
+	"internal/abi":            struct{}{},
+	"internal/bytealg":        struct{}{},
+	"internal/cpu":            struct{}{},
+	"internal/goarch":         struct{}{},
+	"internal/goos":           struct{}{},
+	"runtime":                 struct{}{},
+	"runtime/internal/atomic": struct{}{},
+	"runtime/internal/math":   struct{}{},
+	"runtime/internal/sys":    struct{}{},
+}
+
 // The Go toolchain.
 
 type gcToolchain struct{}
@@ -88,11 +100,8 @@ func (gcToolchain) gc(b *Builder, a *Action, archive string, importcfg, embedcfg
 	if p.Standard {
 		gcargs = append(gcargs, "-std")
 	}
-	compilingRuntime := p.Standard && (p.ImportPath == "runtime" || strings.HasPrefix(p.ImportPath, "runtime/internal"))
-	// The runtime package imports a couple of general internal packages.
-	if p.Standard && (p.ImportPath == "internal/cpu" || p.ImportPath == "internal/bytealg" || p.ImportPath == "internal/abi") {
-		compilingRuntime = true
-	}
+	_, compilingRuntime := runtimePackages[p.ImportPath]
+	compilingRuntime = compilingRuntime && p.Standard
 	if compilingRuntime {
 		// runtime compiles with a special gc flag to check for
 		// memory allocations that are invalid in the runtime package,
diff --git a/src/cmd/go/internal/work/gccgo.go b/src/cmd/go/internal/work/gccgo.go
index 1499536932d..3cb7b641833 100644
--- a/src/cmd/go/internal/work/gccgo.go
+++ b/src/cmd/go/internal/work/gccgo.go
@@ -16,8 +16,8 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/fsys"
 	"cmd/go/internal/load"
-	"cmd/go/internal/str"
 	"cmd/internal/pkgpath"
+	"cmd/internal/str"
 )
 
 // The Gccgo toolchain.
diff --git a/src/cmd/go/internal/work/security.go b/src/cmd/go/internal/work/security.go
index 36bbab37ee2..e9b9f6c6c0f 100644
--- a/src/cmd/go/internal/work/security.go
+++ b/src/cmd/go/internal/work/security.go
@@ -208,8 +208,8 @@ var validLinkerFlags = []*lazyregexp.Regexp{
 	re(`-Wl,-z,(no)?execstack`),
 	re(`-Wl,-z,relro`),
 
-	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
-	re(`\./.*\.(a|o|obj|dll|dylib|so)`),
+	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so|tbd)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
+	re(`\./.*\.(a|o|obj|dll|dylib|so|tbd)`),
 }
 
 var validLinkerFlagsWithNextArg = []string{
diff --git a/src/cmd/go/internal/work/security_test.go b/src/cmd/go/internal/work/security_test.go
index 4f2e0eb21ab..8d4be0abfc0 100644
--- a/src/cmd/go/internal/work/security_test.go
+++ b/src/cmd/go/internal/work/security_test.go
@@ -164,6 +164,8 @@ var goodLinkerFlags = [][]string{
 	{"-Wl,-framework", "-Wl,Chocolate"},
 	{"-Wl,-framework,Chocolate"},
 	{"-Wl,-unresolved-symbols=ignore-all"},
+	{"libcgotbdtest.tbd"},
+	{"./libcgotbdtest.tbd"},
 }
 
 var badLinkerFlags = [][]string{
diff --git a/src/cmd/go/main.go b/src/cmd/go/main.go
index 02174a56ff0..16361e02ca7 100644
--- a/src/cmd/go/main.go
+++ b/src/cmd/go/main.go
@@ -145,24 +145,6 @@ func main() {
 		os.Exit(2)
 	}
 
-	if err := buildcfg.Error; err != nil {
-		fmt.Fprintf(os.Stderr, "go: %v\n", buildcfg.Error)
-		os.Exit(2)
-	}
-
-	// Set environment (GOOS, GOARCH, etc) explicitly.
-	// In theory all the commands we invoke should have
-	// the same default computation of these as we do,
-	// but in practice there might be skew
-	// This makes sure we all agree.
-	cfg.OrigEnv = os.Environ()
-	cfg.CmdEnv = envcmd.MkEnv()
-	for _, env := range cfg.CmdEnv {
-		if os.Getenv(env.Name) != env.Value {
-			os.Setenv(env.Name, env.Value)
-		}
-	}
-
 BigCmdLoop:
 	for bigCmd := base.Go; ; {
 		for _, cmd := range bigCmd.Commands {
@@ -188,18 +170,7 @@ BigCmdLoop:
 			if !cmd.Runnable() {
 				continue
 			}
-			cmd.Flag.Usage = func() { cmd.Usage() }
-			if cmd.CustomFlags {
-				args = args[1:]
-			} else {
-				base.SetFromGOFLAGS(&cmd.Flag)
-				cmd.Flag.Parse(args[1:])
-				args = cmd.Flag.Args()
-			}
-			ctx := maybeStartTrace(context.Background())
-			ctx, span := trace.StartSpan(ctx, fmt.Sprint("Running ", cmd.Name(), " command"))
-			cmd.Run(ctx, cmd, args)
-			span.Done()
+			invoke(cmd, args)
 			base.Exit()
 			return
 		}
@@ -213,6 +184,39 @@ BigCmdLoop:
 	}
 }
 
+func invoke(cmd *base.Command, args []string) {
+	// 'go env' handles checking the build config
+	if cmd != envcmd.CmdEnv {
+		buildcfg.Check()
+	}
+
+	// Set environment (GOOS, GOARCH, etc) explicitly.
+	// In theory all the commands we invoke should have
+	// the same default computation of these as we do,
+	// but in practice there might be skew
+	// This makes sure we all agree.
+	cfg.OrigEnv = os.Environ()
+	cfg.CmdEnv = envcmd.MkEnv()
+	for _, env := range cfg.CmdEnv {
+		if os.Getenv(env.Name) != env.Value {
+			os.Setenv(env.Name, env.Value)
+		}
+	}
+
+	cmd.Flag.Usage = func() { cmd.Usage() }
+	if cmd.CustomFlags {
+		args = args[1:]
+	} else {
+		base.SetFromGOFLAGS(&cmd.Flag)
+		cmd.Flag.Parse(args[1:])
+		args = cmd.Flag.Args()
+	}
+	ctx := maybeStartTrace(context.Background())
+	ctx, span := trace.StartSpan(ctx, fmt.Sprint("Running ", cmd.Name(), " command"))
+	cmd.Run(ctx, cmd, args)
+	span.Done()
+}
+
 func init() {
 	base.Usage = mainUsage
 }
diff --git a/src/cmd/go/script_test.go b/src/cmd/go/script_test.go
index 327eaff4450..9ca297e89b4 100644
--- a/src/cmd/go/script_test.go
+++ b/src/cmd/go/script_test.go
@@ -11,6 +11,7 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"flag"
 	"fmt"
 	"go/build"
 	"internal/testenv"
@@ -35,6 +36,8 @@ import (
 	"cmd/internal/sys"
 )
 
+var testSum = flag.String("testsum", "", `may be tidy, listm, or listall. If set, TestScript generates a go.sum file at the beginning of each test and updates test files if they pass.`)
+
 // TestScript runs the tests in testdata/script/*.txt.
 func TestScript(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
@@ -269,6 +272,22 @@ func (ts *testScript) run() {
 		ts.mark = ts.log.Len()
 	}
 
+	// With -testsum, if a go.mod file is present in the test's initial
+	// working directory, run 'go mod tidy'.
+	if *testSum != "" {
+		if ts.updateSum(a) {
+			defer func() {
+				if ts.t.Failed() {
+					return
+				}
+				data := txtar.Format(a)
+				if err := os.WriteFile(ts.file, data, 0666); err != nil {
+					ts.t.Errorf("rewriting test file: %v", err)
+				}
+			}()
+		}
+	}
+
 	// Run script.
 	// See testdata/script/README for documentation of script form.
 	script := string(a.Comment)
@@ -517,7 +536,7 @@ func (ts *testScript) cmdCd(want simpleStatus, args []string) {
 		ts.fatalf("usage: cd dir")
 	}
 
-	dir := args[0]
+	dir := filepath.FromSlash(args[0])
 	if !filepath.IsAbs(dir) {
 		dir = filepath.Join(ts.cd, dir)
 	}
@@ -1341,6 +1360,68 @@ func (ts *testScript) parse(line string) command {
 	return cmd
 }
 
+// updateSum runs 'go mod tidy', 'go list -mod=mod -m all', or
+// 'go list -mod=mod all' in the test's current directory if a file named
+// "go.mod" is present after the archive has been extracted. updateSum modifies
+// archive and returns true if go.mod or go.sum were changed.
+func (ts *testScript) updateSum(archive *txtar.Archive) (rewrite bool) {
+	gomodIdx, gosumIdx := -1, -1
+	for i := range archive.Files {
+		switch archive.Files[i].Name {
+		case "go.mod":
+			gomodIdx = i
+		case "go.sum":
+			gosumIdx = i
+		}
+	}
+	if gomodIdx < 0 {
+		return false
+	}
+
+	switch *testSum {
+	case "tidy":
+		ts.cmdGo(success, []string{"mod", "tidy"})
+	case "listm":
+		ts.cmdGo(success, []string{"list", "-m", "-mod=mod", "all"})
+	case "listall":
+		ts.cmdGo(success, []string{"list", "-mod=mod", "all"})
+	default:
+		ts.t.Fatalf(`unknown value for -testsum %q; may be "tidy", "listm", or "listall"`, *testSum)
+	}
+
+	newGomodData, err := os.ReadFile(filepath.Join(ts.cd, "go.mod"))
+	if err != nil {
+		ts.t.Fatalf("reading go.mod after -testsum: %v", err)
+	}
+	if !bytes.Equal(newGomodData, archive.Files[gomodIdx].Data) {
+		archive.Files[gomodIdx].Data = newGomodData
+		rewrite = true
+	}
+
+	newGosumData, err := os.ReadFile(filepath.Join(ts.cd, "go.sum"))
+	if err != nil && !os.IsNotExist(err) {
+		ts.t.Fatalf("reading go.sum after -testsum: %v", err)
+	}
+	switch {
+	case os.IsNotExist(err) && gosumIdx >= 0:
+		// go.sum was deleted.
+		rewrite = true
+		archive.Files = append(archive.Files[:gosumIdx], archive.Files[gosumIdx+1:]...)
+	case err == nil && gosumIdx < 0:
+		// go.sum was created.
+		rewrite = true
+		gosumIdx = gomodIdx + 1
+		archive.Files = append(archive.Files, txtar.File{})
+		copy(archive.Files[gosumIdx+1:], archive.Files[gosumIdx:])
+		archive.Files[gosumIdx] = txtar.File{Name: "go.sum", Data: newGosumData}
+	case err == nil && gosumIdx >= 0 && !bytes.Equal(newGosumData, archive.Files[gosumIdx].Data):
+		// go.sum was changed.
+		rewrite = true
+		archive.Files[gosumIdx].Data = newGosumData
+	}
+	return rewrite
+}
+
 // diff returns a formatted diff of the two texts,
 // showing the entire text and the minimum line-level
 // additions and removals to turn text1 into text2.
diff --git a/src/cmd/go/testdata/mod/rsc.io_sampler_v1.2.1.txt b/src/cmd/go/testdata/mod/rsc.io_sampler_v1.2.1.txt
index 00b71bf0d59..7982cccea10 100644
--- a/src/cmd/go/testdata/mod/rsc.io_sampler_v1.2.1.txt
+++ b/src/cmd/go/testdata/mod/rsc.io_sampler_v1.2.1.txt
@@ -5,7 +5,7 @@ module "rsc.io/sampler"
 
 require "golang.org/x/text" v0.0.0-20170915032832-14c0d48ead0c
 -- .info --
-{"Version":"v1.2.1","Name":"cac3af4f8a0ab40054fa6f8d423108a63a1255bb","Short":"cac3af4f8a0a","Time":"2018-02-13T18:16:22Z"}EOF
+{"Version":"v1.2.1","Name":"cac3af4f8a0ab40054fa6f8d423108a63a1255bb","Short":"cac3af4f8a0a","Time":"2018-02-13T18:16:22Z"}
 -- hello.go --
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/cmd/go/testdata/script/README b/src/cmd/go/testdata/script/README
index d7e67bb7b60..48e4055b0bd 100644
--- a/src/cmd/go/testdata/script/README
+++ b/src/cmd/go/testdata/script/README
@@ -102,6 +102,7 @@ The commands are:
 
 - cd dir
   Change to the given directory for future commands.
+  The directory must use slashes as path separator.
 
 - chmod perm path...
   Change the permissions of the files or directories named by the path arguments
diff --git a/src/cmd/go/testdata/script/badgo.txt b/src/cmd/go/testdata/script/badgo.txt
new file mode 100644
index 00000000000..cf4e2584d65
--- /dev/null
+++ b/src/cmd/go/testdata/script/badgo.txt
@@ -0,0 +1,50 @@
+go get example.net/badgo@v1.0.0
+go get example.net/badgo@v1.1.0
+go get example.net/badgo@v1.2.0
+go get example.net/badgo@v1.3.0
+go get example.net/badgo@v1.4.0
+go get example.net/badgo@v1.5.0
+! go get example.net/badgo@v1.6.0
+stderr 'invalid go version .X.Y.: must match format 1.23'
+
+-- go.mod --
+module m
+
+replace (
+	example.net/badgo v1.0.0 => ./v1.0.0
+	example.net/badgo v1.1.0 => ./v1.1.0
+	example.net/badgo v1.2.0 => ./v1.2.0
+	example.net/badgo v1.3.0 => ./v1.3.0
+	example.net/badgo v1.4.0 => ./v1.4.0
+	example.net/badgo v1.5.0 => ./v1.5.0
+	example.net/badgo v1.6.0 => ./v1.6.0
+)
+
+-- v1.0.0/go.mod --
+module example.net/badgo
+go 1.17.0
+
+-- v1.1.0/go.mod --
+module example.net/badgo
+go 1.17rc2
+
+-- v1.2.0/go.mod --
+module example.net/badgo
+go 1.17.1
+
+-- v1.3.0/go.mod --
+module example.net/badgo
+go v1.17.0
+
+-- v1.4.0/go.mod --
+module example.net/badgo
+go v1.17.0-rc.2
+
+-- v1.5.0/go.mod --
+module example.net/badgo
+go v1.17.1
+
+-- v1.6.0/go.mod --
+module example.net/badgo
+go X.Y
+
diff --git a/src/cmd/go/testdata/script/build_ignore_leading_bom.txt b/src/cmd/go/testdata/script/build_ignore_leading_bom.txt
new file mode 100644
index 00000000000..37141f3466b
--- /dev/null
+++ b/src/cmd/go/testdata/script/build_ignore_leading_bom.txt
@@ -0,0 +1,27 @@
+# Per https://golang.org/ref/spec#Source_code_representation:
+# a compiler may ignore a UTF-8-encoded byte order mark (U+FEFF)
+# if it is the first Unicode code point in the source text.
+
+go list -f 'Imports: {{.Imports}} EmbedFiles: {{.EmbedFiles}}' .
+stdout '^Imports: \[embed m/hello\] EmbedFiles: \[.*file\]$'
+
+-- go.mod --
+module m
+
+go 1.16
+-- m.go --
+package main
+
+import (
+	_ "embed"
+
+	"m/hello"
+)
+
+//go:embed file
+var s string
+
+-- hello/hello.go --
+package hello
+
+-- file --
diff --git a/src/cmd/go/testdata/script/build_package_not_stale_trailing_slash.txt b/src/cmd/go/testdata/script/build_package_not_stale_trailing_slash.txt
deleted file mode 100644
index 38a151ef1f6..00000000000
--- a/src/cmd/go/testdata/script/build_package_not_stale_trailing_slash.txt
+++ /dev/null
@@ -1,13 +0,0 @@
-# Tests Issue #12690
-
-[gccgo] skip 'gccgo does not have GOROOT'
-
-! stale runtime
-! stale os
-! stale io
-
-env GOROOT=$GOROOT'/'
-
-! stale runtime
-! stale os
-! stale io
\ No newline at end of file
diff --git a/src/cmd/go/testdata/script/cgo_stale.txt b/src/cmd/go/testdata/script/cgo_stale.txt
new file mode 100644
index 00000000000..9e46855eadb
--- /dev/null
+++ b/src/cmd/go/testdata/script/cgo_stale.txt
@@ -0,0 +1,39 @@
+# golang.org/issue/46347: a stale runtime/cgo should only force a single rebuild
+
+[!cgo] skip
+[short] skip
+
+
+# If we set a unique CGO_CFLAGS, the installed copy of runtime/cgo
+# should be reported as stale.
+
+env CGO_CFLAGS=-DTestScript_cgo_stale=true
+stale runtime/cgo
+
+
+# If we then build a package that uses cgo, runtime/cgo should be rebuilt and
+# cached with the new flag, but not installed to GOROOT (and thus still stale).
+
+env GOCACHE=$WORK/cache  # Use a fresh cache to avoid interference between runs.
+
+go build -x .
+stderr '[/\\]cgo'$GOEXE'["]? .* -importpath runtime/cgo'
+stale runtime/cgo
+
+
+# After runtime/cgo has been rebuilt and cached, it should not be rebuilt again
+# even though it is still reported as stale.
+
+go build -x .
+! stderr '[/\\]cgo'$GOEXE'["]? .* -importpath runtime/cgo'
+stale runtime/cgo
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+-- m.go --
+package m
+
+import "C"
diff --git a/src/cmd/go/testdata/script/env_cross_build.txt b/src/cmd/go/testdata/script/env_cross_build.txt
new file mode 100644
index 00000000000..3feeba6b141
--- /dev/null
+++ b/src/cmd/go/testdata/script/env_cross_build.txt
@@ -0,0 +1,29 @@
+# Test that the corect default GOEXPERIMENT is used when cross
+# building with GOENV (#46815).
+
+# Unset variables set by the TestScript harness. Users typically won't
+# explicitly configure these, and #46815 doesn't repro if they are.
+env GOOS=
+env GOARCH=
+env GOEXPERIMENT=
+
+env GOENV=windows-amd64
+go build internal/abi
+
+env GOENV=ios-arm64
+go build internal/abi
+
+env GOENV=linux-mips
+go build internal/abi
+
+-- windows-amd64 --
+GOOS=windows
+GOARCH=amd64
+
+-- ios-arm64 --
+GOOS=ios
+GOARCH=arm64
+
+-- linux-mips --
+GOOS=linux
+GOARCH=mips
diff --git a/src/cmd/go/testdata/script/env_exp.txt b/src/cmd/go/testdata/script/env_exp.txt
new file mode 100644
index 00000000000..681512d87c6
--- /dev/null
+++ b/src/cmd/go/testdata/script/env_exp.txt
@@ -0,0 +1,17 @@
+# Test GOEXPERIMENT variable
+
+# go env shows default empty GOEXPERIMENT
+go env
+stdout GOEXPERIMENT=
+
+# go env shows valid experiments
+env GOEXPERIMENT=fieldtrack,staticlockranking
+go env GOEXPERIMENT
+stdout '.*fieldtrack.*staticlockranking.*'
+go env
+stdout 'GOEXPERIMENT=.*fieldtrack.*staticlockranking.*'
+
+# go env rejects unknown experiments
+env GOEXPERIMENT=bad
+! go env GOEXPERIMENT
+stderr 'unknown GOEXPERIMENT bad'
diff --git a/src/cmd/go/testdata/script/env_unset.txt b/src/cmd/go/testdata/script/env_unset.txt
new file mode 100644
index 00000000000..4e0f2495098
--- /dev/null
+++ b/src/cmd/go/testdata/script/env_unset.txt
@@ -0,0 +1,30 @@
+# Test that we can unset variables, even if initially invalid,
+# as long as resulting config is valid.
+
+env GOENV=badenv
+env GOOS=
+env GOARCH=
+env GOEXPERIMENT=
+
+! go env
+stderr '^go(\.exe)?: unknown GOEXPERIMENT badexp$'
+
+go env -u GOEXPERIMENT
+
+! go env
+stderr '^cmd/go: unsupported GOOS/GOARCH pair bados/badarch$'
+
+! go env -u GOOS
+stderr '^go env -u: unsupported GOOS/GOARCH pair \w+/badarch$'
+
+! go env -u GOARCH
+stderr '^go env -u: unsupported GOOS/GOARCH pair bados/\w+$'
+
+go env -u GOOS GOARCH
+
+go env
+
+-- badenv --
+GOOS=bados
+GOARCH=badarch
+GOEXPERIMENT=badexp
diff --git a/src/cmd/go/testdata/script/env_write.txt b/src/cmd/go/testdata/script/env_write.txt
index 4fa39df1044..b5e97391679 100644
--- a/src/cmd/go/testdata/script/env_write.txt
+++ b/src/cmd/go/testdata/script/env_write.txt
@@ -179,3 +179,9 @@ stderr 'unsupported GOOS/GOARCH.*windows/mips$'
 stderr 'go env -w: GOMODCACHE entry is relative; must be absolute path: "~/test"'
 ! go env -w GOMODCACHE=./test
 stderr 'go env -w: GOMODCACHE entry is relative; must be absolute path: "./test"'
+
+# go env -w checks validity of GOEXPERIMENT
+env GOEXPERIMENT=
+! go env -w GOEXPERIMENT=badexp
+stderr 'unknown GOEXPERIMENT badexp'
+go env -w GOEXPERIMENT=fieldtrack
diff --git a/src/cmd/go/testdata/script/list_cgo_compiled_importmap.txt b/src/cmd/go/testdata/script/list_cgo_compiled_importmap.txt
new file mode 100644
index 00000000000..3d68ef30559
--- /dev/null
+++ b/src/cmd/go/testdata/script/list_cgo_compiled_importmap.txt
@@ -0,0 +1,38 @@
+# Regression test for https://golang.org/issue/46462.
+#
+# The "runtime/cgo" import found in synthesized .go files (reported in
+# the CompiledGoFiles field) should have a corresponding entry in the
+# ImportMap field when a runtime/cgo variant (such as a test variant)
+# will be used.
+
+[short] skip  # -compiled can be slow (because it compiles things)
+[!cgo] skip
+
+env CGO_ENABLED=1
+env GOFLAGS=-tags=netcgo  # Force net to use cgo even on Windows.
+
+
+# "runtime/cgo [runtime.test]" appears in the the test dependencies of "runtime",
+# because "runtime/cgo" itself depends on "runtime"
+
+go list -deps -test -compiled -f '{{if eq .ImportPath "net [runtime.test]"}}{{printf "%q" .Imports}}{{end}}' runtime
+
+	# Control case: the explicitly-imported package "sync" is a test variant,
+	# because "sync" depends on "runtime".
+stdout '"sync \[runtime\.test\]"'
+! stdout '"sync"'
+
+	# Experiment: the implicitly-imported package "runtime/cgo" is also a test variant,
+	# because "runtime/cgo" also depends on "runtime".
+stdout '"runtime/cgo \[runtime\.test\]"'
+! stdout '"runtime/cgo"'
+
+
+# Because the import of "runtime/cgo" in the cgo-generated file actually refers
+# to "runtime/cgo [runtime.test]", the latter should be listed in the ImportMap.
+# BUG(#46462): Today, it is not.
+
+go list -deps -test -compiled -f '{{if eq .ImportPath "net [runtime.test]"}}{{printf "%q" .ImportMap}}{{end}}' runtime
+
+stdout '"sync":"sync \[runtime\.test\]"'                # control
+stdout '"runtime/cgo":"runtime/cgo \[runtime\.test\]"'  # experiment
diff --git a/src/cmd/go/testdata/script/list_find_nodeps.txt b/src/cmd/go/testdata/script/list_find_nodeps.txt
new file mode 100644
index 00000000000..e08ce789509
--- /dev/null
+++ b/src/cmd/go/testdata/script/list_find_nodeps.txt
@@ -0,0 +1,49 @@
+# Issue #46092
+# go list -find should always return a package with an empty Deps list
+
+# The linker loads implicit dependencies
+go list -find -f {{.Deps}} ./cmd
+stdout '\[\]'
+
+# Cgo translation may add imports of "unsafe", "runtime/cgo" and "syscall"
+go list -find -f {{.Deps}} ./cgo
+stdout '\[\]'
+
+# SWIG adds imports of some standard packages
+go list -find -f {{.Deps}} ./swig
+stdout '\[\]'
+
+-- go.mod --
+module listfind
+
+-- cmd/main.go --
+package main
+
+func main() {}
+
+-- cgo/pkg.go --
+package cgopkg
+
+/*
+#include 
+*/
+import "C"
+
+func F() {
+    println(C.INT_MAX)
+}
+
+-- cgo/pkg_notcgo.go --
+//go:build !cgo
+// +build !cgo
+
+package cgopkg
+
+func F() {
+    println(0)
+}
+
+-- swig/pkg.go --
+package swigpkg
+
+-- swig/a.swigcxx --
diff --git a/src/cmd/go/testdata/script/list_gomod_in_gopath.txt b/src/cmd/go/testdata/script/list_gomod_in_gopath.txt
new file mode 100644
index 00000000000..064f33adc36
--- /dev/null
+++ b/src/cmd/go/testdata/script/list_gomod_in_gopath.txt
@@ -0,0 +1,23 @@
+# Issue 46119
+
+# When a module is inside a GOPATH workspace, Package.Root should be set to
+# Module.Dir instead of $GOPATH/src.
+
+env GOPATH=$WORK/tmp
+cd $WORK/tmp/src/test
+
+go list -f {{.Root}}
+stdout ^$PWD$
+
+# Were we really inside a GOPATH workspace?
+env GO111MODULE=off
+go list -f {{.Root}}
+stdout ^$WORK/tmp$
+
+-- $WORK/tmp/src/test/go.mod --
+module test
+
+-- $WORK/tmp/src/test/main.go --
+package main
+
+func main() {}
diff --git a/src/cmd/go/testdata/script/list_load_err.txt b/src/cmd/go/testdata/script/list_load_err.txt
index b3b72713e54..0cfa7fbed2f 100644
--- a/src/cmd/go/testdata/script/list_load_err.txt
+++ b/src/cmd/go/testdata/script/list_load_err.txt
@@ -2,26 +2,42 @@
 # other files in the same package cause go/build.Import to return an error.
 # Verfifies golang.org/issue/38568
 
-
 go list -e -deps ./scan
 stdout m/want
 
-
 go list -e -deps ./multi
 stdout m/want
 
-
 go list -e -deps ./constraint
 stdout m/want
 
-
 [cgo] go list -e -test -deps ./cgotest
 [cgo] stdout m/want
 
-
 [cgo] go list -e -deps ./cgoflag
 [cgo] stdout m/want
 
+
+# go list -e should include files with errors in GoFiles, TestGoFiles, and
+# other lists, assuming they match constraints.
+# Verifies golang.org/issue/39986
+go list -e -f '{{range .GoFiles}}{{.}},{{end}}' ./scan
+stdout '^good.go,scan.go,$'
+
+go list -e -f '{{range .GoFiles}}{{.}},{{end}}' ./multi
+stdout '^a.go,b.go,$'
+
+go list -e -f '{{range .GoFiles}}{{.}},{{end}}' ./constraint
+stdout '^good.go,$'
+go list -e -f '{{range .IgnoredGoFiles}}{{.}},{{end}}' ./constraint
+stdout '^constraint.go,$'
+
+[cgo] go list -e -f '{{range .XTestGoFiles}}{{.}},{{end}}' ./cgotest
+[cgo] stdout '^cgo_test.go,$'
+
+[cgo] go list -e -f '{{range .GoFiles}}{{.}},{{end}}' ./cgoflag
+[cgo] stdout '^cgoflag.go,$'
+
 -- go.mod --
 module m
 
diff --git a/src/cmd/go/testdata/script/list_std_stale.txt b/src/cmd/go/testdata/script/list_std_stale.txt
deleted file mode 100644
index e5c1f334fd4..00000000000
--- a/src/cmd/go/testdata/script/list_std_stale.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-# https://golang.org/issue/44725: packages in std should not be reported as stale,
-# regardless of whether they are listed from within or outside GOROOT/src.
-
-# Control case: net should not be stale at the start of the test,
-# and should depend on vendor/golang.org/… instead of golang.org/….
-
-! stale net
-
-go list -deps net
-stdout '^vendor/golang.org/x/net'
-! stdout '^golang.org/x/net'
-
-# Net should also not be stale when viewed from within GOROOT/src,
-# and should still report the same package dependencies.
-
-cd $GOROOT/src
-! stale net
-
-go list -deps net
-stdout '^vendor/golang.org/x/net'
-! stdout '^golang.org/x/net'
-
-
-# However, 'go mod' and 'go get' subcommands should report the original module
-# dependencies, not the vendored packages.
-
-[!net] stop
-
-env GOPROXY=
-go mod why -m golang.org/x/net
-stdout '^# golang.org/x/net\nnet\ngolang.org/x/net'
diff --git a/src/cmd/go/testdata/script/list_std_vendor.txt b/src/cmd/go/testdata/script/list_std_vendor.txt
new file mode 100644
index 00000000000..8f27cc1e8d8
--- /dev/null
+++ b/src/cmd/go/testdata/script/list_std_vendor.txt
@@ -0,0 +1,32 @@
+# https://golang.org/issue/44725: packages in std should have the same
+# dependencies regardless of whether they are listed from within or outside
+# GOROOT/src.
+
+# Control case: net, viewed from outside the 'std' module,
+# should depend on vendor/golang.org/… instead of golang.org/….
+
+go list -deps net
+stdout '^vendor/golang.org/x/net'
+! stdout '^golang.org/x/net'
+cp stdout $WORK/net-deps.txt
+
+
+# It should still report the same package dependencies when viewed from
+# within GOROOT/src.
+
+cd $GOROOT/src
+
+go list -deps net
+stdout '^vendor/golang.org/x/net'
+! stdout '^golang.org/x/net'
+cmp stdout $WORK/net-deps.txt
+
+
+# However, 'go mod' and 'go get' subcommands should report the original module
+# dependencies, not the vendored packages.
+
+[!net] stop
+
+env GOPROXY=
+go mod why -m golang.org/x/net
+stdout '^# golang.org/x/net\nnet\ngolang.org/x/net'
diff --git a/src/cmd/go/testdata/script/mod_all.txt b/src/cmd/go/testdata/script/mod_all.txt
index 090eeee22df..6fa2d832396 100644
--- a/src/cmd/go/testdata/script/mod_all.txt
+++ b/src/cmd/go/testdata/script/mod_all.txt
@@ -315,7 +315,7 @@ go 1.15
 
 require (
 	example.com/a v0.1.0
-	example.com/b v0.1.0
+	example.com/b v0.1.0 // indirect
 	example.com/q v0.1.0
 	example.com/r v0.1.0 // indirect
 	example.com/t v0.1.0
diff --git a/src/cmd/go/testdata/script/mod_deprecate_message.txt b/src/cmd/go/testdata/script/mod_deprecate_message.txt
index 4a0674b8084..567027935dc 100644
--- a/src/cmd/go/testdata/script/mod_deprecate_message.txt
+++ b/src/cmd/go/testdata/script/mod_deprecate_message.txt
@@ -1,26 +1,26 @@
 # When there is a short single-line message, 'go get' should print it all.
 go get -d short
-stderr '^go: warning: module short is deprecated: short$'
+stderr '^go: module short is deprecated: short$'
 go list -m -u -f '{{.Deprecated}}' short
 stdout '^short$'
 
 # When there is a multi-line message, 'go get' should print the first line.
 go get -d multiline
-stderr '^go: warning: module multiline is deprecated: first line$'
+stderr '^go: module multiline is deprecated: first line$'
 ! stderr 'second line'
 go list -m -u -f '{{.Deprecated}}' multiline
 stdout '^first line\nsecond line.$'
 
 # When there is a long message, 'go get' should print a placeholder.
 go get -d long
-stderr '^go: warning: module long is deprecated: \(message omitted: too long\)$'
+stderr '^go: module long is deprecated: \(message omitted: too long\)$'
 go list -m -u -f '{{.Deprecated}}' long
 stdout '^aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa$'
 
 # When a message contains unprintable chracters, 'go get' should say that
 # without printing the message.
 go get -d unprintable
-stderr '^go: warning: module unprintable is deprecated: \(message omitted: contains non-printable characters\)$'
+stderr '^go: module unprintable is deprecated: \(message omitted: contains non-printable characters\)$'
 go list -m -u -f '{{.Deprecated}}' unprintable
 stdout '^message contains ASCII BEL\x07$'
 
diff --git a/src/cmd/go/testdata/script/mod_download.txt b/src/cmd/go/testdata/script/mod_download.txt
index 8a9faffe4e0..c2b72b2a02c 100644
--- a/src/cmd/go/testdata/script/mod_download.txt
+++ b/src/cmd/go/testdata/script/mod_download.txt
@@ -107,13 +107,28 @@ stderr '^go mod download: skipping argument m that resolves to the main module\n
 ! go mod download m@latest
 stderr '^go mod download: m@latest: malformed module path "m": missing dot in first path element$'
 
-# download updates go.mod and populates go.sum
+# download without arguments updates go.mod and go.sum after loading the
+# build list, but does not save sums for downloaded zips.
 cd update
+cp go.mod.orig go.mod
 ! exists go.sum
 go mod download
+cmp go.mod.update go.mod
+cmp go.sum.update go.sum
+cp go.mod.orig go.mod
+rm go.sum
+
+# download with arguments (even "all") does update go.mod and go.sum.
+go mod download rsc.io/sampler
+cmp go.mod.update go.mod
 grep '^rsc.io/sampler v1.3.0 ' go.sum
-go list -m rsc.io/sampler
-stdout '^rsc.io/sampler v1.3.0$'
+cp go.mod.orig go.mod
+rm go.sum
+
+go mod download all
+cmp go.mod.update go.mod
+grep '^rsc.io/sampler v1.3.0 ' go.sum
+cd ..
 
 # allow go mod download without go.mod
 env GO111MODULE=auto
@@ -131,7 +146,7 @@ stderr 'get '$GOPROXY
 -- go.mod --
 module m
 
--- update/go.mod --
+-- update/go.mod.orig --
 module m
 
 go 1.16
@@ -140,3 +155,16 @@ require (
 	rsc.io/quote v1.5.2
 	rsc.io/sampler v1.2.1 // older version than in build list
 )
+-- update/go.mod.update --
+module m
+
+go 1.16
+
+require (
+	rsc.io/quote v1.5.2
+	rsc.io/sampler v1.3.0 // older version than in build list
+)
+-- update/go.sum.update --
+golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0=
+rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
diff --git a/src/cmd/go/testdata/script/mod_e.txt b/src/cmd/go/testdata/script/mod_e.txt
index 3a0d18dabc2..3cffaf6ef1c 100644
--- a/src/cmd/go/testdata/script/mod_e.txt
+++ b/src/cmd/go/testdata/script/mod_e.txt
@@ -24,11 +24,11 @@ cmp go.mod.orig go.mod
 
 ! go mod vendor
 
-stderr '^example.com/untidy imports\n\texample.net/directnotfound: cannot find module providing package example.net/directnotfound: module example.net/directnotfound: reading http://.*: 404 Not Found$'
+stderr '^example.com/untidy imports\n\texample.net/directnotfound: no required module provides package example.net/directnotfound; to add it:\n\tgo get example.net/directnotfound$'
 
-stderr '^example.com/untidy imports\n\texample.net/m imports\n\texample.net/indirectnotfound: cannot find module providing package example.net/indirectnotfound: module example.net/indirectnotfound: reading http://.*: 404 Not Found$'
+stderr '^example.com/untidy imports\n\texample.net/m: module example.net/m provides package example.net/m and is replaced but not required; to add it:\n\tgo get example.net/m@v0.1.0$'
 
-stderr '^example.com/untidy tested by\n\texample.com/untidy.test imports\n\texample.net/directtestnotfound: cannot find module providing package example.net/directtestnotfound: module example.net/directtestnotfound: reading http://.*: 404 Not Found$'
+stderr '^example.com/untidy tested by\n\texample.com/untidy.test imports\n\texample.net/directtestnotfound: no required module provides package example.net/directtestnotfound; to add it:\n\tgo get example.net/directtestnotfound$'
 
 ! stderr 'indirecttestnotfound'  # Vendor prunes test dependencies.
 
@@ -43,16 +43,23 @@ stderr -count=4 'cannot find module providing package'
 cmp go.mod.final go.mod
 
 
-# 'go mod vendor -e' still logs the errors, but succeeds and updates go.mod.
-
+# 'go mod vendor -e' still logs the errors, but creates a vendor directory
+# and exits with status 0.
+# 'go mod vendor -e' does not update go.mod and will not vendor packages that
+# would require changing go.mod, for example, by adding a requirement.
 cp go.mod.orig go.mod
 go mod vendor -e
-stderr -count=3 'cannot find module providing package'
-cmp go.mod.final go.mod
+stderr -count=2 'no required module provides package'
+stderr '^example.com/untidy imports\n\texample.net/m: module example.net/m provides package example.net/m and is replaced but not required; to add it:\n\tgo get example.net/m@v0.1.0$'
+exists vendor/modules.txt
+! exists vendor/example.net
+
+go mod edit -require example.net/m@v0.1.0
+go mod vendor -e
+stderr -count=3 'no required module provides package'
 exists vendor/modules.txt
 exists vendor/example.net/m/m.go
 
-
 -- go.mod --
 module example.com/untidy
 go 1.16
diff --git a/src/cmd/go/testdata/script/mod_edit_no_modcache.txt b/src/cmd/go/testdata/script/mod_edit_no_modcache.txt
new file mode 100644
index 00000000000..ced15bb3018
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_edit_no_modcache.txt
@@ -0,0 +1,15 @@
+# 'go mod edit' opportunistically locks the side-lock file in the module cache,
+# for compatibility with older versions of the 'go' command.
+# It does not otherwise depend on the module cache, so it should not
+# fail if the module cache directory cannot be created.
+
+[root] skip
+
+mkdir $WORK/readonly
+chmod 0555 $WORK/readonly
+env GOPATH=$WORK/readonly/nonexist
+
+go mod edit -go=1.17
+
+-- go.mod --
+module example.com/m
diff --git a/src/cmd/go/testdata/script/mod_get_commit.txt b/src/cmd/go/testdata/script/mod_get_commit.txt
index 4649491a532..0cf94ae1821 100644
--- a/src/cmd/go/testdata/script/mod_get_commit.txt
+++ b/src/cmd/go/testdata/script/mod_get_commit.txt
@@ -44,7 +44,7 @@ go mod edit -require rsc.io/quote@23179ee
 grep 'rsc.io/quote 23179ee' go.mod
 
 # but other commands fix them
-go mod graph
+go list -m -mod=mod all
 grep 'rsc.io/quote v1.5.1' go.mod
 
 -- go.mod --
diff --git a/src/cmd/go/testdata/script/mod_get_deprecate_install.txt b/src/cmd/go/testdata/script/mod_get_deprecate_install.txt
index d832b5f2e80..63cd27a42d2 100644
--- a/src/cmd/go/testdata/script/mod_get_deprecate_install.txt
+++ b/src/cmd/go/testdata/script/mod_get_deprecate_install.txt
@@ -7,16 +7,33 @@ go get example.com/cmd/a
 stderr '^go get: installing executables with ''go get'' in module mode is deprecated.$'
 stderr 'Use ''go install pkg@version'' instead.'
 
-
-go mod init m
+cp go.mod.orig go.mod
 
 # 'go get' inside a module with a non-main package does not print a message.
 # This will stop building in the future, but it's the command we want to use.
 go get rsc.io/quote
 ! stderr deprecated
+cp go.mod.orig go.mod
 
 # 'go get' inside a module with an executable prints a different
 # deprecation message.
 go get example.com/cmd/a
 stderr '^go get: installing executables with ''go get'' in module mode is deprecated.$'
 stderr 'To adjust and download dependencies of the current module, use ''go get -d'''
+cp go.mod.orig go.mod
+
+# 'go get' should not print a warning for a main package inside the main module.
+# The intent is most likely to update the dependencies of that package.
+# 'go install' would be used otherwise.
+go get m
+! stderr .
+cp go.mod.orig go.mod
+
+-- go.mod.orig --
+module m
+
+go 1.17
+-- main.go --
+package main
+
+func main() {}
diff --git a/src/cmd/go/testdata/script/mod_get_deprecated.txt b/src/cmd/go/testdata/script/mod_get_deprecated.txt
index 4633009f69b..7bdd7a58a89 100644
--- a/src/cmd/go/testdata/script/mod_get_deprecated.txt
+++ b/src/cmd/go/testdata/script/mod_get_deprecated.txt
@@ -4,14 +4,14 @@ go get -d ./use/nothing
 
 # 'go get pkg' should show a deprecation message for the module providing pkg.
 go get -d example.com/deprecated/a
-stderr '^go: warning: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
+stderr '^go: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
 go get -d example.com/deprecated/a@v1.0.0
-stderr '^go: warning: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
+stderr '^go: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
 
 # 'go get pkg' should show a deprecation message for a module providing
 # packages directly imported by pkg.
 go get -d ./use/a
-stderr '^go: warning: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
+stderr '^go: module example.com/deprecated/a is deprecated: in example.com/deprecated/a@v1.9.0$'
 
 # 'go get pkg' may show a deprecation message for an indirectly required module
 # if it provides a package named on the command line.
@@ -20,7 +20,7 @@ go get -d ./use/b
 go get -d local/use
 ! stderr 'module.*is deprecated'
 go get -d example.com/deprecated/b
-stderr '^go: warning: module example.com/deprecated/b is deprecated: in example.com/deprecated/b@v1.9.0$'
+stderr '^go: module example.com/deprecated/b is deprecated: in example.com/deprecated/b@v1.9.0$'
 
 # 'go get pkg' does not show a deprecation message for a module providing a
 # directly imported package if the module is no longer deprecated in its
diff --git a/src/cmd/go/testdata/script/mod_get_lazy_indirect.txt b/src/cmd/go/testdata/script/mod_get_lazy_indirect.txt
new file mode 100644
index 00000000000..1cef9d1c0cf
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_get_lazy_indirect.txt
@@ -0,0 +1,44 @@
+# https://golang.org/issue/45979: after 'go get' on a package,
+# that package should be importable without error.
+
+
+# We start out with an unresolved dependency.
+# 'go list' suggests that we run 'go get' on that dependency.
+
+! go list -deps .
+stderr '^m.go:3:8: no required module provides package rsc\.io/quote; to add it:\n\tgo get rsc.io/quote$'
+
+
+# When we run the suggested 'go get' command, the new dependency can be used
+# immediately.
+#
+# 'go get' marks the new dependency as 'indirect', because it doesn't scan
+# enough source code to know whether it is direct, and it is easier and less
+# invasive to remove an incorrect indirect mark (e.g. using 'go get') than to
+# add one that is missing ('go mod tidy' or 'go mod vendor').
+
+go get rsc.io/quote
+grep 'rsc.io/quote v\d+\.\d+\.\d+ // indirect$' go.mod
+! grep 'rsc.io/quote v\d+\.\d+\.\d+$' go.mod
+
+go list -deps .
+! stderr .
+[!short] go build .
+[!short] ! stderr .
+
+
+# 'go get .' (or 'go mod tidy') removes the indirect mark.
+
+go get .
+grep 'rsc.io/quote v\d+\.\d+\.\d+$' go.mod
+! grep 'rsc.io/quote v\d+\.\d+\.\d+ // indirect$' go.mod
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+-- m.go --
+package m
+
+import _ "rsc.io/quote"
diff --git a/src/cmd/go/testdata/script/mod_get_trailing_slash.txt b/src/cmd/go/testdata/script/mod_get_trailing_slash.txt
index 3b38d8ba7d3..c5366935379 100644
--- a/src/cmd/go/testdata/script/mod_get_trailing_slash.txt
+++ b/src/cmd/go/testdata/script/mod_get_trailing_slash.txt
@@ -1,6 +1,3 @@
-# Populate go.sum
-go mod download
-
 # go list should succeed to load a package ending with ".go" if the path does
 # not correspond to an existing local file. Listing a pattern ending with
 # ".go/" should try to list a package regardless of whether a file exists at the
@@ -31,3 +28,10 @@ module m
 go 1.13
 
 require example.com/dotgo.go v1.0.0
+-- go.sum --
+example.com/dotgo.go v1.0.0 h1:XKJfs0V8x2PvY2tX8bJBCEbCDLnt15ma2onwhVpew/I=
+example.com/dotgo.go v1.0.0/go.mod h1:Qi6z/X3AC5vHiuMt6HF2ICx3KhIBGrMdrA7YoPDKqR0=
+-- use.go --
+package use
+
+import _ "example.com/dotgo.go"
diff --git a/src/cmd/go/testdata/script/mod_get_update_unrelated_sum.txt b/src/cmd/go/testdata/script/mod_get_update_unrelated_sum.txt
new file mode 100644
index 00000000000..0093c0eda0c
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_get_update_unrelated_sum.txt
@@ -0,0 +1,120 @@
+# Check that 'go get' adds sums for updated modules if we had sums before,
+# even if we didn't load packages from them.
+# Verifies #44129.
+
+env fmt='{{.ImportPath}}: {{if .Error}}{{.Error.Err}}{{else}}ok{{end}}'
+
+# Control case: before upgrading, we have the sums we need.
+# go list -deps -e -f $fmt .
+# stdout '^rsc.io/quote: ok$'
+# ! stdout rsc.io/sampler  # not imported by quote in this version
+cp go.mod.orig go.mod
+cp go.sum.orig go.sum
+go mod tidy
+cmp go.mod.orig go.mod
+cmp go.sum.orig go.sum
+
+
+# Upgrade a module. This also upgrades rsc.io/quote, and though we didn't load
+# a package from it, we had the sum for its old version, so we need the
+# sum for the new version, too.
+go get -d example.com/upgrade@v0.0.2
+grep '^rsc.io/quote v1.5.2 ' go.sum
+
+# The upgrade still breaks the build because the new version of quote imports
+# rsc.io/sampler, and we don't have its zip sum.
+go list -deps -e -f $fmt
+stdout 'rsc.io/quote: ok'
+stdout 'rsc.io/sampler: missing go.sum entry for module providing package rsc.io/sampler'
+cp go.mod.orig go.mod
+cp go.sum.orig go.sum
+
+
+# Replace the old version with a directory before upgrading.
+# We didn't need a sum for it before (even though we had one), so we won't
+# fetch a new sum.
+go mod edit -replace rsc.io/quote@v1.0.0=./dummy
+go get -d example.com/upgrade@v0.0.2
+! grep '^rsc.io/quote v1.5.2 ' go.sum
+cp go.mod.orig go.mod
+cp go.sum.orig go.sum
+
+
+# Replace the new version with a directory before upgrading.
+# We can't get a sum for a directory.
+go mod edit -replace rsc.io/quote@v1.5.2=./dummy
+go get -d example.com/upgrade@v0.0.2
+! grep '^rsc.io/quote v1.5.2 ' go.sum
+cp go.mod.orig go.mod
+cp go.sum.orig go.sum
+
+
+# Replace the new version with a different version.
+# We should get a sum for that version.
+go mod edit -replace rsc.io/quote@v1.5.2=rsc.io/quote@v1.5.1
+go get -d example.com/upgrade@v0.0.2
+! grep '^rsc.io/quote v1.5.2 ' go.sum
+grep '^rsc.io/quote v1.5.1 ' go.sum
+cp go.mod.orig go.mod
+cp go.sum.orig go.sum
+
+
+# Delete the new version's zip (but not mod) from the cache and go offline.
+# 'go get' should fail when fetching the zip.
+rm $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.2.zip
+env GOPROXY=off
+! go get -d example.com/upgrade@v0.0.2
+stderr '^go: upgraded rsc.io/quote v1.0.0 => v1.5.2: error finding sum for rsc.io/quote@v1.5.2: module lookup disabled by GOPROXY=off$'
+
+-- go.mod.orig --
+module m
+
+go 1.16
+
+require (
+	example.com/upgrade v0.0.1
+	rsc.io/quote v1.0.0
+)
+
+replace (
+	example.com/upgrade v0.0.1 => ./upgrade1
+	example.com/upgrade v0.0.2 => ./upgrade2
+)
+-- go.sum.orig --
+rsc.io/quote v1.0.0 h1:kQ3IZQzPTiDJxSZI98YaWgxFEhlNdYASHvh+MplbViw=
+rsc.io/quote v1.0.0/go.mod h1:v83Ri/njykPcgJltBc/gEkJTmjTsNgtO1Y7vyIK1CQA=
+-- go.sum.want --
+golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+rsc.io/quote v1.0.0 h1:kQ3IZQzPTiDJxSZI98YaWgxFEhlNdYASHvh+MplbViw=
+rsc.io/quote v1.0.0/go.mod h1:v83Ri/njykPcgJltBc/gEkJTmjTsNgtO1Y7vyIK1CQA=
+rsc.io/quote v1.5.2 h1:3fEykkD9k7lYzXqCYrwGAf7iNhbk4yCjHmKBN9td4L0=
+rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0=
+rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
+-- use.go --
+package use
+
+import (
+	_ "example.com/upgrade"
+	_ "rsc.io/quote"
+)
+-- upgrade1/go.mod --
+module example.com/upgrade
+
+go 1.16
+-- upgrade1/upgrade.go --
+package upgrade
+-- upgrade2/go.mod --
+module example.com/upgrade
+
+go 1.16
+
+require rsc.io/quote v1.5.2 // indirect
+-- upgrade2/upgrade.go --
+package upgrade
+-- dummy/go.mod --
+module rsc.io/quote
+
+go 1.16
+-- dummy/quote.go --
+package quote
+
diff --git a/src/cmd/go/testdata/script/mod_getmode_vendor.txt b/src/cmd/go/testdata/script/mod_getmode_vendor.txt
index d3df2078b07..00070c03b53 100644
--- a/src/cmd/go/testdata/script/mod_getmode_vendor.txt
+++ b/src/cmd/go/testdata/script/mod_getmode_vendor.txt
@@ -25,6 +25,7 @@ stderr 'go list -m: can''t match module patterns using the vendor directory\n\t\
 -- go.mod --
 module x
 
+go 1.16
 -- x.go --
 package x
 import _ "rsc.io/quote"
diff --git a/src/cmd/go/testdata/script/mod_go_version_missing.txt b/src/cmd/go/testdata/script/mod_go_version_missing.txt
index aca36a04506..d704816729b 100644
--- a/src/cmd/go/testdata/script/mod_go_version_missing.txt
+++ b/src/cmd/go/testdata/script/mod_go_version_missing.txt
@@ -73,10 +73,9 @@ module example.com/m
 
 go $goversion
 
-require (
-	example.com/dep v0.1.0
-	example.com/testdep v0.1.0 // indirect
-)
+require example.com/dep v0.1.0
+
+require example.com/testdep v0.1.0 // indirect
 
 replace (
 	example.com/dep v0.1.0 => ./dep
diff --git a/src/cmd/go/testdata/script/mod_graph_version.txt b/src/cmd/go/testdata/script/mod_graph_version.txt
new file mode 100644
index 00000000000..f9a73f4617b
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_graph_version.txt
@@ -0,0 +1,101 @@
+# For this module, Go 1.17 prunes out a (transitive and otherwise-irrelevant)
+# requirement on a retracted higher version of a dependency.
+# However, when Go 1.16 reads the same requirements from the go.mod file,
+# it does not prune out that requirement, and selects the retracted version.
+#
+# The Go 1.16 module graph looks like:
+#
+# m ---- lazy v0.1.0 ---- requireincompatible v0.1.0 ---- incompatible v2.0.0+incompatible
+# |        |
+# + -------+------------- incompatible v1.0.0
+#
+# The Go 1.17 module graph is the same except that the dependencies of
+# requireincompatible are pruned out (because the module that requires
+# it — lazy v0.1.0 — specifies 'go 1.17', and it is not otherwise relevant to
+# the main module).
+
+cp go.mod go.mod.orig
+
+go mod graph
+cp stdout graph-1.17.txt
+stdout '^example\.com/m example\.com/retract/incompatible@v1\.0\.0$'
+stdout '^example\.net/lazy@v0\.1\.0 example\.com/retract/incompatible@v1\.0\.0$'
+! stdout 'example\.com/retract/incompatible@v2\.0\.0\+incompatible'
+
+go mod graph -go=1.17
+cmp stdout graph-1.17.txt
+
+cmp go.mod go.mod.orig
+
+
+# Setting -go=1.16 should report the graph as viewed by Go 1.16,
+# but should not edit the go.mod file.
+
+go mod graph -go=1.16
+cp stdout graph-1.16.txt
+stdout '^example\.com/m example\.com/retract/incompatible@v1\.0\.0$'
+stdout '^example\.net/lazy@v0\.1\.0 example.com/retract/incompatible@v1\.0\.0$'
+stdout '^example.net/requireincompatible@v0.1.0 example.com/retract/incompatible@v2\.0\.0\+incompatible$'
+
+cmp go.mod go.mod.orig
+
+
+# If we actually update the go.mod file to the requested go version,
+# we should get the same selected versions, but the roots of the graph
+# may be updated.
+#
+# TODO(#45551): The roots should not be updated.
+
+go mod edit -go=1.16
+go mod graph
+! stdout '^example\.com/m example\.com/retract/incompatible@v1\.0\.0$'
+stdout '^example\.net/lazy@v0.1.0 example.com/retract/incompatible@v1\.0\.0$'
+stdout '^example.net/requireincompatible@v0.1.0 example.com/retract/incompatible@v2\.0\.0\+incompatible$'
+	# TODO(#45551): cmp stdout graph-1.16.txt
+
+
+# Unsupported go versions should be rejected, since we don't know
+# what versions they would report.
+! go mod graph -go=1.99999999999
+stderr '^invalid value "1\.99999999999" for flag -go: maximum supported Go version is '$goversion'\nusage: go mod graph \[-go=version\]\nRun ''go help mod graph'' for details.$'
+
+
+-- go.mod --
+// Module m indirectly imports a package from
+// example.com/retract/incompatible. Its selected version of
+// that module is lower under Go 1.17 semantics than under Go 1.16.
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/requireincompatible v0.1.0 => ./requireincompatible
+)
+
+require (
+	example.com/retract/incompatible v1.0.0 // indirect
+	example.net/lazy v0.1.0
+)
+-- lazy/go.mod --
+// Module lazy requires example.com/retract/incompatible v1.0.0.
+//
+// When viewed from the outside it also has a transitive dependency
+// on v2.0.0+incompatible, but in lazy mode that transitive dependency
+// is pruned out.
+module example.net/lazy
+
+go 1.17
+
+exclude example.com/retract/incompatible v2.0.0+incompatible
+
+require (
+	example.com/retract/incompatible v1.0.0
+	example.net/requireincompatible v0.1.0
+)
+-- requireincompatible/go.mod --
+module example.net/requireincompatible
+
+go 1.15
+
+require example.com/retract/incompatible v2.0.0+incompatible
diff --git a/src/cmd/go/testdata/script/mod_init_path.txt b/src/cmd/go/testdata/script/mod_init_path.txt
index ccdfc923175..e5fd4ddbcb9 100644
--- a/src/cmd/go/testdata/script/mod_init_path.txt
+++ b/src/cmd/go/testdata/script/mod_init_path.txt
@@ -1,7 +1,7 @@
 env GO111MODULE=on
 
 ! go mod init .
-stderr '^go: invalid module path "\.": is a local import path$'
+stderr '^go: malformed module path ".": is a local import path$'
 
 cd x
 go mod init example.com/x
diff --git a/src/cmd/go/testdata/script/mod_install_hint.txt b/src/cmd/go/testdata/script/mod_install_hint.txt
new file mode 100644
index 00000000000..ab02840eb8b
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_install_hint.txt
@@ -0,0 +1,5 @@
+# Module is replaced but not required. No hint appears as no module is suggested.
+go mod init m
+go mod edit -replace=github.com/notrequired@v0.5.0=github.com/doesnotexist@v0.5.0
+! go install github.com/notrequired
+! stderr 'to add it:'
\ No newline at end of file
diff --git a/src/cmd/go/testdata/script/mod_install_pkg_version.txt b/src/cmd/go/testdata/script/mod_install_pkg_version.txt
index 2c14ef737b3..fd02392af1b 100644
--- a/src/cmd/go/testdata/script/mod_install_pkg_version.txt
+++ b/src/cmd/go/testdata/script/mod_install_pkg_version.txt
@@ -143,7 +143,7 @@ stderr '^go: warning: "example.com/cmd/nomatch\.\.\." matched no packages$'
 
 # If a wildcard matches only non-main packges, we should see a different warning.
 go install example.com/cmd/err...@v1.0.0
-stderr '^go: warning: "example.com/cmd/err\.\.\." matched no main packages$'
+stderr '^go: warning: "example.com/cmd/err\.\.\." matched only non-main packages$'
 
 
 # 'go install pkg@version' should report errors if the module contains
diff --git a/src/cmd/go/testdata/script/mod_invalid_path.txt b/src/cmd/go/testdata/script/mod_invalid_path.txt
index c8c075daaef..333a3ffa35c 100644
--- a/src/cmd/go/testdata/script/mod_invalid_path.txt
+++ b/src/cmd/go/testdata/script/mod_invalid_path.txt
@@ -8,11 +8,8 @@ stderr '^go: no module declaration in go.mod. To specify the module path:\n\tgo
 # Test that go mod init in GOPATH doesn't add a module declaration
 # with a path that can't possibly be a module path, because
 # it isn't even a valid import path.
-# The single quote and backtick are the only characters  we don't allow
-# in checkModulePathLax, but is allowed in a Windows file name.
-# TODO(matloob): choose a different character once
-# module.CheckImportPath is laxened and replaces
-# checkModulePathLax.
+# The single quote and backtick are the only characters which are not allowed
+# but are a valid Windows file name.
 cd $WORK/'gopath/src/m''d'
 ! go mod init
 stderr 'cannot determine module path'
@@ -21,7 +18,7 @@ stderr 'cannot determine module path'
 # possibly be a module path, because it isn't even a valid import path
 cd $WORK/gopath/src/badname
 ! go list .
-stderr 'invalid module path'
+stderr 'malformed module path'
 
 # Test that an import path containing an element with a leading dot is valid,
 # but such a module path is not.
diff --git a/src/cmd/go/testdata/script/mod_invalid_version.txt b/src/cmd/go/testdata/script/mod_invalid_version.txt
index 34d9c47674e..6846a792a5d 100644
--- a/src/cmd/go/testdata/script/mod_invalid_version.txt
+++ b/src/cmd/go/testdata/script/mod_invalid_version.txt
@@ -19,7 +19,7 @@ cp go.mod.orig go.mod
 go mod edit -require golang.org/x/text@14c0d48ead0c
 cd outside
 ! go list -m golang.org/x/text
-stderr 'go list -m: example.com@v0.0.0 \(replaced by \./\..\): parsing ../go.mod: '$WORK'/gopath/src/go.mod:5: require golang.org/x/text: version "14c0d48ead0c" invalid: must be of the form v1.2.3'
+stderr 'go list -m: example.com@v0.0.0 \(replaced by \./\.\.\): parsing ..[/\\]go.mod: '$WORK'[/\\]gopath[/\\]src[/\\]go.mod:5: require golang.org/x/text: version "14c0d48ead0c" invalid: must be of the form v1.2.3'
 cd ..
 go list -m golang.org/x/text
 stdout 'golang.org/x/text v0.1.1-0.20170915032832-14c0d48ead0c'
@@ -47,10 +47,10 @@ cp go.mod.orig go.mod
 go mod edit -require golang.org/x/text@v2.1.1-0.20170915032832-14c0d48ead0c
 cd outside
 ! go list -m golang.org/x/text
-stderr 'go list -m: example.com@v0.0.0 \(replaced by \./\.\.\): parsing ../go.mod: '$WORK'/gopath/src/go.mod:5: require golang.org/x/text: version "v2.1.1-0.20170915032832-14c0d48ead0c" invalid: should be v0 or v1, not v2'
+stderr 'go list -m: example.com@v0.0.0 \(replaced by \./\.\.\): parsing ..[/\\]go.mod: '$WORK'[/\\]gopath[/\\]src[/\\]go.mod:5: require golang.org/x/text: version "v2.1.1-0.20170915032832-14c0d48ead0c" invalid: should be v0 or v1, not v2'
 cd ..
 ! go list -m golang.org/x/text
-stderr $WORK'/gopath/src/go.mod:5: require golang.org/x/text: version "v2.1.1-0.20170915032832-14c0d48ead0c" invalid: should be v0 or v1, not v2'
+stderr $WORK'[/\\]gopath[/\\]src[/\\]go.mod:5: require golang.org/x/text: version "v2.1.1-0.20170915032832-14c0d48ead0c" invalid: should be v0 or v1, not v2'
 
 # A pseudo-version with fewer than 12 digits of SHA-1 prefix is invalid.
 cp go.mod.orig go.mod
diff --git a/src/cmd/go/testdata/script/mod_lazy_import_allmod.txt b/src/cmd/go/testdata/script/mod_lazy_import_allmod.txt
index 3dc1515df26..97718c4513b 100644
--- a/src/cmd/go/testdata/script/mod_lazy_import_allmod.txt
+++ b/src/cmd/go/testdata/script/mod_lazy_import_allmod.txt
@@ -139,9 +139,10 @@ go 1.17
 require (
 	a v0.1.0
 	b v0.1.0
-	c v0.1.0 // indirect
 )
 
+require c v0.1.0 // indirect
+
 replace (
 	a v0.1.0 => ./a1
 	b v0.1.0 => ./b1
diff --git a/src/cmd/go/testdata/script/mod_lazy_new_import.txt b/src/cmd/go/testdata/script/mod_lazy_new_import.txt
index 86b14b64b6f..4272a52de1c 100644
--- a/src/cmd/go/testdata/script/mod_lazy_new_import.txt
+++ b/src/cmd/go/testdata/script/mod_lazy_new_import.txt
@@ -78,10 +78,9 @@ module example.com/lazy
 
 go 1.17
 
-require (
-	example.com/a v0.1.0
-	example.com/b v0.1.0 // indirect
-)
+require example.com/a v0.1.0
+
+require example.com/b v0.1.0 // indirect
 
 replace (
 	example.com/a v0.1.0 => ./a
@@ -94,8 +93,9 @@ module example.com/lazy
 
 go 1.17
 
+require example.com/a v0.1.0
+
 require (
-	example.com/a v0.1.0
 	example.com/b v0.1.0 // indirect
 	example.com/c v0.1.0 // indirect
 )
diff --git a/src/cmd/go/testdata/script/mod_lazy_test_of_test_dep.txt b/src/cmd/go/testdata/script/mod_lazy_test_of_test_dep.txt
index 722712d1f2c..68a5b6dca2a 100644
--- a/src/cmd/go/testdata/script/mod_lazy_test_of_test_dep.txt
+++ b/src/cmd/go/testdata/script/mod_lazy_test_of_test_dep.txt
@@ -148,10 +148,9 @@ module example.com/lazy
 
 go 1.17
 
-require (
-	example.com/a v0.1.0
-	example.com/b v0.1.0 // indirect
-)
+require example.com/a v0.1.0
+
+require example.com/b v0.1.0 // indirect
 
 replace (
 	example.com/a v0.1.0 => ./a
diff --git a/src/cmd/go/testdata/script/mod_list_retract.txt b/src/cmd/go/testdata/script/mod_list_retract.txt
index 4b133485152..b7147aa1824 100644
--- a/src/cmd/go/testdata/script/mod_list_retract.txt
+++ b/src/cmd/go/testdata/script/mod_list_retract.txt
@@ -101,7 +101,9 @@ module example.com/use
 go 1.15
 
 require example.com/retract v1.0.0-bad
-
+-- go.sum --
+example.com/retract v1.0.0-bad h1:liAW69rbtjY67x2CcNzat668L/w+YGgNX3lhJsWIJis=
+example.com/retract v1.0.0-bad/go.mod h1:0DvGGofJ9hr1q63cBrOY/jSY52OwhRGA0K47NE80I5Y=
 -- use.go --
 package use
 
diff --git a/src/cmd/go/testdata/script/mod_list_test_cycle.txt b/src/cmd/go/testdata/script/mod_list_test_cycle.txt
new file mode 100644
index 00000000000..755e50b0767
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_list_test_cycle.txt
@@ -0,0 +1,23 @@
+# https://golang.org/issue/45863: a typo in a test package leading to an
+# import cycle should be diagnosed, instead of causing an infinite loop.
+# The failure mode of this test prior to the fix was a timeout or OOM crash.
+
+go list -e -test -deps ./datastore/sql
+
+-- go.mod --
+module golang.org/issue45863
+
+go 1.17
+-- datastore/datastore_health.go --
+package datastore
+
+import (
+	"golang.org/issue45863/datastore"
+	"golang.org/issue45863/datastore/sql"
+)
+-- datastore/sql/sql.go --
+package sql
+-- datastore/sql/sql_test.go --
+package sql
+
+import _ "golang.org/issue45863/datastore"
diff --git a/src/cmd/go/testdata/script/mod_overlay.txt b/src/cmd/go/testdata/script/mod_overlay.txt
index 92e79c725a3..86ab04bd3cf 100644
--- a/src/cmd/go/testdata/script/mod_overlay.txt
+++ b/src/cmd/go/testdata/script/mod_overlay.txt
@@ -21,7 +21,7 @@ go list -deps -overlay overlay.json .
 cd $WORK/gopath/src/get-doesnt-add-dep
 cp $WORK/overlay/get_doesnt_add_dep_go_mod $WORK/want_go_mod
 ! go get -d -overlay overlay.json .
-stderr 'overlaid files can''t be opened for write'
+stderr '^go: updates to go.mod needed, but go.mod is part of the overlay specified with -overlay$'
 cmp $WORK/overlay/get_doesnt_add_dep_go_mod $WORK/want_go_mod
 
 # Content of overlaid go.sum is used.
@@ -41,10 +41,10 @@ go mod verify -overlay overlay.json
 # attempting to update the file
 cp incomplete-sum-file $WORK/overlay/overlay-sum-used-correct-sums
 ! go get -d -overlay overlay.json .
-stderr 'overlaid files can''t be opened for write'
+stderr '^go: updates to go.sum needed, but go.sum is part of the overlay specified with -overlay$'
 cmp incomplete-sum-file $WORK/overlay/overlay-sum-used-correct-sums
 ! go mod tidy -overlay overlay.json
-stderr 'overlaid files can''t be opened for write'
+stderr '^go: updates to go.sum needed, but go.sum is part of the overlay specified with -overlay$'
 cmp incomplete-sum-file $WORK/overlay/overlay-sum-used-correct-sums
 
 # -overlay works with -modfile.
@@ -56,7 +56,7 @@ go list -modfile=alternate.mod -overlay overlay.json .
 stdout 'found.the/module'
 # Even with -modfile, overlaid files can't be opened for write.
 ! go get -modfile=alternate.mod -overlay overlay.json -d rsc.io/quote
-stderr 'overlaid files can''t be opened for write'
+stderr '^go: updates to go.mod needed, but go.mod is part of the overlay specified with -overlay$'
 
 # Carving out a module by adding an overlaid go.mod file
 cd $WORK/gopath/src/carve
@@ -78,7 +78,7 @@ go list -overlay overlay.json all
 stdout ^carve2/nomod$
 # Editing go.mod file fails because overlay is read only
 ! go get -overlay overlay.json -d rsc.io/quote
-stderr 'overlaid files can''t be opened for write'
+stderr '^go: updates to go.mod needed, but go.mod is part of the overlay specified with -overlay$'
 ! grep rsc.io/quote $WORK/overlay/carve2-nomod-go.mod
 # Editing go.mod file succeeds because we use -modfile to redirect to same file
 go get -overlay overlay.json -modfile $WORK/overlay/carve2-nomod-go.mod -d rsc.io/quote
diff --git a/src/cmd/go/testdata/script/mod_query.txt b/src/cmd/go/testdata/script/mod_query.txt
index e10185709d9..a75f86ed7c5 100644
--- a/src/cmd/go/testdata/script/mod_query.txt
+++ b/src/cmd/go/testdata/script/mod_query.txt
@@ -1,9 +1,7 @@
 env GO111MODULE=on
 
-# Populate go.sum.
 # TODO(golang.org/issue/41297): we shouldn't need go.sum. None of the commands
 # below depend on the build list.
-go mod download
 
 go list -m -versions rsc.io/quote
 stdout '^rsc.io/quote v1.0.0 v1.1.0 v1.2.0 v1.2.1 v1.3.0 v1.4.0 v1.5.0 v1.5.1 v1.5.2 v1.5.3-pre1$'
@@ -36,6 +34,9 @@ stdout 'no matching versions for query ">v1.5.3"'
 module x
 require rsc.io/quote v1.0.0
 
+-- go.sum --
+rsc.io/quote v1.0.0 h1:kQ3IZQzPTiDJxSZI98YaWgxFEhlNdYASHvh+MplbViw=
+rsc.io/quote v1.0.0/go.mod h1:v83Ri/njykPcgJltBc/gEkJTmjTsNgtO1Y7vyIK1CQA=
 -- use.go --
 package use
 
diff --git a/src/cmd/go/testdata/script/mod_replace.txt b/src/cmd/go/testdata/script/mod_replace.txt
index dc9667f1d0d..a0a367fb1db 100644
--- a/src/cmd/go/testdata/script/mod_replace.txt
+++ b/src/cmd/go/testdata/script/mod_replace.txt
@@ -48,7 +48,7 @@ stderr 'module rsc.io/quote/v3@upgrade found \(v3.0.0, replaced by ./local/rsc.i
 # The reported Dir and GoMod for a replaced module should be accurate.
 cp go.mod.orig go.mod
 go mod edit -replace=rsc.io/quote/v3=not-rsc.io/quote@v0.1.0-nomod
-go mod download
+go mod download rsc.io/quote/v3
 go list -m -f '{{.Path}} {{.Version}} {{.Dir}} {{.GoMod}}{{with .Replace}} => {{.Path}} {{.Version}} {{.Dir}} {{.GoMod}}{{end}}' rsc.io/quote/v3
 stdout '^rsc.io/quote/v3 v3.0.0 '$GOPATH'[/\\]pkg[/\\]mod[/\\]not-rsc.io[/\\]quote@v0.1.0-nomod '$GOPATH'[/\\]pkg[/\\]mod[/\\]cache[/\\]download[/\\]not-rsc.io[/\\]quote[/\\]@v[/\\]v0.1.0-nomod.mod => not-rsc.io/quote v0.1.0-nomod '$GOPATH'[/\\]pkg[/\\]mod[/\\]not-rsc.io[/\\]quote@v0.1.0-nomod '$GOPATH'[/\\]pkg[/\\]mod[/\\]cache[/\\]download[/\\]not-rsc.io[/\\]quote[/\\]@v[/\\]v0.1.0-nomod.mod$'
 
diff --git a/src/cmd/go/testdata/script/mod_retention.txt b/src/cmd/go/testdata/script/mod_retention.txt
index 0e639db551d..481c10d2b7d 100644
--- a/src/cmd/go/testdata/script/mod_retention.txt
+++ b/src/cmd/go/testdata/script/mod_retention.txt
@@ -39,12 +39,14 @@ go list -mod=mod all
 cmp go.mod go.mod.tidy
 
 # "// indirect" comments should be added if appropriate.
+# TODO(#42504): add case for 'go list -mod=mod -tags=any all' when -tags=any
+# is supported. Only a command that loads "all" without build constraints
+# (except "ignore") has enough information to add "// indirect" comments.
+# 'go mod tidy' and 'go mod vendor' are the only commands that do that,
+# but 'go mod vendor' cannot write go.mod.
 cp go.mod.toodirect go.mod
 go list all
 cmp go.mod go.mod.toodirect
-go mod vendor # loads everything, so adds "// indirect" comments.
-cmp go.mod go.mod.tidy
-rm -r vendor
 
 
 # Redundant requirements should be preserved...
@@ -140,8 +142,9 @@ module m
 go $goversion
 
 require (
-	golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c // indirect
 	rsc.io/quote v1.5.2
 	rsc.io/sampler v1.3.0 // indirect
 	rsc.io/testonly v1.0.0 // indirect
 )
+
+require golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c // indirect
diff --git a/src/cmd/go/testdata/script/mod_retract.txt b/src/cmd/go/testdata/script/mod_retract.txt
index a52e05bc72e..4f95ece8d7a 100644
--- a/src/cmd/go/testdata/script/mod_retract.txt
+++ b/src/cmd/go/testdata/script/mod_retract.txt
@@ -1,8 +1,5 @@
 cp go.mod go.mod.orig
 
-# Populate go.sum.
-go mod download
-
 # 'go list pkg' does not report an error when a retracted version is used.
 go list -e -f '{{if .Error}}{{.Error}}{{end}}' ./use
 ! stdout .
@@ -32,6 +29,11 @@ go 1.15
 
 require example.com/retract v1.0.0-bad
 
+-- go.sum --
+example.com/retract v1.0.0-bad h1:liAW69rbtjY67x2CcNzat668L/w+YGgNX3lhJsWIJis=
+example.com/retract v1.0.0-bad/go.mod h1:0DvGGofJ9hr1q63cBrOY/jSY52OwhRGA0K47NE80I5Y=
+example.com/retract/self/prev v1.1.0 h1:0/8I/GTG+1eJTFeDQ/fUbgrMsVHHyKhh3Z8DSZp1fuA=
+example.com/retract/self/prev v1.1.0/go.mod h1:xl2EcklWuZZHVtHWcpzfSJQmnzAGpKZYpA/Wto7SZN4=
 -- use/use.go --
 package use
 
diff --git a/src/cmd/go/testdata/script/mod_run_nonmain.txt b/src/cmd/go/testdata/script/mod_run_nonmain.txt
new file mode 100644
index 00000000000..036755d2d1a
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_run_nonmain.txt
@@ -0,0 +1,18 @@
+! go run $PWD
+! stderr 'no packages loaded'
+stderr '^package example.net/nonmain is not a main package$'
+
+! go run .
+stderr '^package example.net/nonmain is not a main package$'
+
+! go run ./...
+stderr '^go: warning: "\./\.\.\." matched only non-main packages$'
+stderr '^go run: no packages loaded from \./\.\.\.$'
+
+-- go.mod --
+module example.net/nonmain
+
+go 1.17
+-- nonmain.go --
+// Package nonmain is not a main package.
+package nonmain
diff --git a/src/cmd/go/testdata/script/mod_run_pkgerror.txt b/src/cmd/go/testdata/script/mod_run_pkgerror.txt
new file mode 100644
index 00000000000..48f900dd346
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_run_pkgerror.txt
@@ -0,0 +1,32 @@
+# https://golang.org/issue/39986: files reported as invalid by go/build should
+# be listed in InvalidGoFiles.
+
+go list -e -f '{{.Incomplete}}{{"\n"}}{{.Error}}{{"\n"}}{{.InvalidGoFiles}}{{"\n"}}' .
+stdout '^true\nfound packages m \(m\.go\) and main \(main\.go\) in '$PWD'\n\[main.go\]\n'
+
+
+# https://golang.org/issue/45827: 'go run .' should report the same package
+# errors as 'go build' and 'go list'.
+
+! go build
+stderr '^found packages m \(m\.go\) and main \(main\.go\) in '$PWD'$'
+
+! go list .
+stderr '^found packages m \(m\.go\) and main \(main\.go\) in '$PWD'$'
+
+! go run .
+! stderr 'no packages loaded'
+stderr '^found packages m \(m\.go\) and main \(main\.go\) in '$PWD'$'
+
+! go run ./...
+! stderr 'no packages loaded'
+stderr '^found packages m \(m\.go\) and main \(main\.go\) in '$PWD'$'
+
+-- go.mod --
+module m
+
+go 1.17
+-- m.go --
+package m
+-- main.go --
+package main
diff --git a/src/cmd/go/testdata/script/mod_sumdb_golang.txt b/src/cmd/go/testdata/script/mod_sumdb_golang.txt
index cc0b0da474a..becd88b52e7 100644
--- a/src/cmd/go/testdata/script/mod_sumdb_golang.txt
+++ b/src/cmd/go/testdata/script/mod_sumdb_golang.txt
@@ -10,45 +10,73 @@ go env GOSUMDB
 stdout '^sum.golang.org$'
 
 # Download direct from github.
+
 [!net] skip
 [!exec:git] skip
 env GOSUMDB=sum.golang.org
 env GOPROXY=direct
+
 go get -d rsc.io/quote@v1.5.2
 cp go.sum saved.sum
 
+
 # Download from proxy.golang.org with go.sum entry already.
 # Use 'go list' instead of 'go get' since the latter may download extra go.mod
 # files not listed in go.sum.
+
 go clean -modcache
 env GOSUMDB=
 env GOPROXY=
-go list -x -deps rsc.io/quote
+
+go list -x -m all  # Download go.mod files.
 ! stderr github
 stderr proxy.golang.org/rsc.io/quote
 ! stderr sum.golang.org/tile
 ! stderr sum.golang.org/lookup/rsc.io/quote
+
+go list -x -deps rsc.io/quote  # Download module source.
+! stderr github
+stderr proxy.golang.org/rsc.io/quote
+! stderr sum.golang.org/tile
+! stderr sum.golang.org/lookup/rsc.io/quote
+
 cmp go.sum saved.sum
 
+
 # Download again.
 # Should use the checksum database to validate new go.sum lines,
 # but not need to fetch any new data from the proxy.
+
 rm go.sum
-go list -mod=mod -x rsc.io/quote
+
+go list -mod=mod -x -m all  # Add checksums for go.mod files.
+stderr sum.golang.org/tile
 ! stderr github
 ! stderr proxy.golang.org/rsc.io/quote
-stderr sum.golang.org/tile
 stderr sum.golang.org/lookup/rsc.io/quote
+
+go list -mod=mod -x rsc.io/quote  # Add checksums for module source.
+! stderr .  # Adds checksums, but for entities already in the module cache.
+
 cmp go.sum saved.sum
 
+
 # test fallback to direct
+
 env TESTGOPROXY404=1
 go clean -modcache
 rm go.sum
-go list -mod=mod -x rsc.io/quote
+
+go list -mod=mod -x -m all  # Download go.mod files
 stderr 'proxy.golang.org.*404 testing'
 stderr github.com/rsc
+
+go list -mod=mod -x rsc.io/quote  # Download module source.
+stderr 'proxy.golang.org.*404 testing'
+stderr github.com/rsc
+
 cmp go.sum saved.sum
 
+
 -- go.mod --
 module m
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat.txt b/src/cmd/go/testdata/script/mod_tidy_compat.txt
new file mode 100644
index 00000000000..e6edef5ee3b
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat.txt
@@ -0,0 +1,95 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# This module has the same module dependency graph in Go 1.16 as in Go 1.17,
+# but in 1.16 requires (checksums for) additional (irrelevant) go.mod files.
+#
+# The module graph under both versions looks like:
+#
+# m ---- example.com/version v1.1.0
+# |
+# + ---- example.net/lazy v0.1.0 ---- example.com/version v1.0.1
+#
+# Go 1.17 avoids loading the go.mod file for example.com/version v1.0.1
+# (because it is lower than the verison explicitly required by m,
+# and the module that requires it — m — specifies 'go 1.17').
+#
+# That go.mod file happens not to affect the final 1.16 module graph anyway,
+# so the pruned graph is equivalent to the unpruned one.
+
+cp go.mod go.mod.orig
+go mod tidy
+cmp go.mod go.mod.orig
+
+go list -m all
+cmp stdout m_all.txt
+
+go mod edit -go=1.16
+go list -m all
+cmp stdout m_all.txt
+
+
+# If we explicitly drop compatibility with 1.16, we retain fewer checksums,
+# which gives a cleaner go.sum file but causes 1.16 to fail in readonly mode.
+
+cp go.mod.orig go.mod
+go mod tidy -compat=1.17
+cmp go.mod go.mod.orig
+
+go list -m all
+cmp stdout m_all.txt
+
+go mod edit -go=1.16
+! go list -m all
+stderr '^go list -m: example.net/lazy@v0.1.0 requires\n\texample.com/version@v1.0.1: missing go.sum entry; to add it:\n\tgo mod download example.com/version$'
+
+
+-- go.mod --
+// Module m happens to have the exact same build list as what would be
+// selected under Go 1.16, but computes that build list without looking at
+// as many go.mod files.
+module example.com/m
+
+go 1.17
+
+replace example.net/lazy v0.1.0 => ./lazy
+
+require (
+	example.com/version v1.1.0
+	example.net/lazy v0.1.0
+)
+-- m_all.txt --
+example.com/m
+example.com/version v1.1.0
+example.net/lazy v0.1.0 => ./lazy
+-- compatible.go --
+package compatible
+
+import (
+	_ "example.com/version"
+	_ "example.net/lazy"
+)
+-- lazy/go.mod --
+// Module lazy requires example.com/version v1.0.1.
+//
+// However, since this module is lazy, its dependents
+// should not need checksums for that version of the module
+// unless they actually import packages from it.
+module example.net/lazy
+
+go 1.17
+
+require example.com/version v1.0.1
+-- lazy/lazy.go --
+package lazy
+
+import _ "example.com/version"
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_added.txt b/src/cmd/go/testdata/script/mod_tidy_compat_added.txt
new file mode 100644
index 00000000000..94fa79bc9f5
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_added.txt
@@ -0,0 +1,105 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# For this module, Go 1.17 produces an error for one module, and Go 1.16
+# produces a different error for a different module.
+
+cp go.mod go.mod.orig
+
+! go mod tidy
+
+stderr '^example\.com/m imports\n\texample\.net/added: module example\.net/added@latest found \(v0\.3\.0, replaced by \./a1\), but does not contain package example\.net/added$'
+
+cmp go.mod go.mod.orig
+
+
+# When we run 'go mod tidy -e', we should proceed past the first error and follow
+# it with a second error describing the version descrepancy.
+#
+# We should not provide advice on how to push past the version descrepancy,
+# because the '-e' flag should already do that, writing out an otherwise-tidied
+# go.mod file.
+
+go mod tidy -e
+
+stderr '^example\.com/m imports\n\texample\.net/added: module example\.net/added@latest found \(v0\.3\.0, replaced by \./a1\), but does not contain package example\.net/added\nexample\.net/added failed to load from any module,\n\tbut go 1\.16 would load it from example\.net/added@v0\.2\.0$'
+
+! stderr '\n\tgo mod tidy'
+
+cmp go.mod go.mod.tidy
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/added v0.1.0 => ./a1
+	example.net/added v0.2.0 => ./a2
+	example.net/added v0.3.0 => ./a1
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/pruned v0.1.0 => ./pruned
+)
+
+require (
+	example.net/added v0.1.0
+	example.net/lazy v0.1.0
+)
+-- go.mod.tidy --
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/added v0.1.0 => ./a1
+	example.net/added v0.2.0 => ./a2
+	example.net/added v0.3.0 => ./a1
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/pruned v0.1.0 => ./pruned
+)
+
+require example.net/lazy v0.1.0
+-- m.go --
+package m
+
+import (
+	_ "example.net/added"
+	_ "example.net/lazy"
+)
+
+-- a1/go.mod --
+module example.net/added
+
+go 1.17
+-- a2/go.mod --
+module example.net/added
+
+go 1.17
+-- a2/added.go --
+package added
+
+-- lazy/go.mod --
+module example.net/lazy
+
+go 1.17
+
+require example.net/pruned v0.1.0
+-- lazy/lazy.go --
+package lazy
+
+-- pruned/go.mod --
+module example.net/pruned
+
+go 1.17
+
+require example.net/added v0.2.0
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_ambiguous.txt b/src/cmd/go/testdata/script/mod_tidy_compat_ambiguous.txt
new file mode 100644
index 00000000000..c544cb7413f
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_ambiguous.txt
@@ -0,0 +1,98 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+# For this module, the dependency providing package
+# example.net/ambiguous/nested/pkg is unambiguous in Go 1.17 (because only one
+# root of the module graph contains the package), whereas it is ambiguous in
+# Go 1.16 (because two different modules contain plausible packages and Go 1.16
+# does not privilege roots above other dependencies).
+#
+# However, the overall build list is identical for both versions.
+
+cp go.mod go.mod.orig
+
+! go mod tidy
+
+stderr '^example\.com/m imports\n\texample\.net/indirect imports\n\texample\.net/ambiguous/nested/pkg loaded from example\.net/ambiguous/nested@v0\.1\.0,\n\tbut go 1.16 would fail to locate it:\n\tambiguous import: found package example\.net/ambiguous/nested/pkg in multiple modules:\n\texample\.net/ambiguous v0.1.0 \(.*\)\n\texample\.net/ambiguous/nested v0.1.0 \(.*\)\n\n'
+
+stderr '\n\nTo proceed despite packages unresolved in go 1\.16:\n\tgo mod tidy -e\nIf reproducibility with go 1.16 is not needed:\n\tgo mod tidy -compat=1\.17\nFor other options, see:\n\thttps://golang\.org/doc/modules/pruning\n'
+
+cmp go.mod go.mod.orig
+
+
+# If we run 'go mod tidy -e', we should still save enough checksums to run
+# 'go list -m all' reproducibly with go 1.16, even though we can't list
+# the specific package.
+
+go mod tidy -e
+! stderr '\n\tgo mod tidy'
+cmp go.mod go.mod.orig
+
+go list -m all
+cmp stdout all-m.txt
+
+go list -f $MODFMT example.net/ambiguous/nested/pkg
+stdout '^example.net/ambiguous/nested v0\.1\.0$'
+! stderr .
+
+go mod edit -go=1.16
+go list -m all
+cmp stdout all-m.txt
+
+! go list -f $MODFMT example.net/ambiguous/nested/pkg
+stderr '^ambiguous import: found package example\.net/ambiguous/nested/pkg in multiple modules:\n\texample\.net/ambiguous v0\.1\.0 \(.*\)\n\texample\.net/ambiguous/nested v0\.1\.0 \(.*\)\n'
+
+
+# On the other hand, if we use -compat=1.17, 1.16 can't even load
+# the build list (due to missing checksums).
+
+cp go.mod.orig go.mod
+go mod tidy -compat=1.17
+! stderr .
+go list -m all
+cmp stdout all-m.txt
+
+go mod edit -go=1.16
+! go list -m all
+stderr '^go list -m: example\.net/indirect@v0\.1\.0 requires\n\texample\.net/ambiguous@v0\.1\.0: missing go\.sum entry; to add it:\n\tgo mod download example\.net/ambiguous\n'
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+
+replace example.net/indirect v0.1.0 => ./indirect
+
+require (
+	example.net/ambiguous/nested v0.1.0 // indirect
+	example.net/indirect v0.1.0
+)
+-- all-m.txt --
+example.com/m
+example.net/ambiguous v0.1.0
+example.net/ambiguous/nested v0.1.0
+example.net/indirect v0.1.0 => ./indirect
+-- m.go --
+package m
+
+import _ "example.net/indirect"
+
+-- indirect/go.mod --
+module example.net/indirect
+
+go 1.17
+
+require example.net/ambiguous v0.1.0
+-- indirect/indirect.go --
+package indirect
+
+import _ "example.net/ambiguous/nested/pkg"
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_deleted.txt b/src/cmd/go/testdata/script/mod_tidy_compat_deleted.txt
new file mode 100644
index 00000000000..dcf13e20490
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_deleted.txt
@@ -0,0 +1,128 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# For this module, the "deleted" dependency contains an imported package, but
+# Go 1.16 selects a higher version (in which that package has been deleted).
+
+cp go.mod go.mod.orig
+
+! go mod tidy
+
+stderr '^example\.com/m imports\n\texample\.net/deleted loaded from example\.net/deleted@v0\.1\.0,\n\tbut go 1\.16 would fail to locate it in example\.net/deleted@v0\.2\.0\n\n'
+
+stderr '\n\nTo upgrade to the versions selected by go 1.16, leaving some packages unresolved:\n\tgo mod tidy -e -go=1\.16 && go mod tidy -e -go=1\.17\nIf reproducibility with go 1.16 is not needed:\n\tgo mod tidy -compat=1\.17\nFor other options, see:\n\thttps://golang\.org/doc/modules/pruning\n'
+
+
+# The suggested 'go mod tidy -e' command should proceed anyway.
+
+go mod tidy -e
+cmp go.mod go.mod.tidy
+
+
+# In 'go 1.16' mode we should error out in the way we claimed.
+
+cd 116-outside
+! go list -deps -f $MODFMT example.com/m
+stderr '^\.\.[/\\]m\.go:4:2: no required module provides package example\.net/deleted; to add it:\n\tgo get example\.net/deleted$'
+cd ..
+
+go mod edit -go=1.16
+! go list -deps -f $MODFMT example.com/m
+stderr '^go: updates to go\.mod needed; to update it:\n\tgo mod tidy$'
+
+! go mod tidy
+stderr '^example\.com/m imports\n\texample\.net/deleted: module example\.net/deleted@latest found \(v0\.2\.0, replaced by \./d2\), but does not contain package example\.net/deleted$'
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/deleted v0.1.0 => ./d1
+	example.net/deleted v0.2.0 => ./d2
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/pruned v0.1.0 => ./pruned
+)
+
+require (
+	example.net/deleted v0.1.0
+	example.net/deleted v0.1.0 // redundant
+	example.net/lazy v0.1.0
+)
+-- go.mod.tidy --
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/deleted v0.1.0 => ./d1
+	example.net/deleted v0.2.0 => ./d2
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/pruned v0.1.0 => ./pruned
+)
+
+require (
+	example.net/deleted v0.1.0
+	example.net/lazy v0.1.0
+)
+-- 116-outside/go.mod --
+module outside
+
+go 1.16
+
+replace (
+	example.com/m => ../
+	example.net/deleted v0.1.0 => ../d1
+	example.net/deleted v0.2.0 => ../d2
+	example.net/lazy v0.1.0 => ../lazy
+	example.net/pruned v0.1.0 => ../pruned
+)
+
+require example.com/m v0.1.0
+-- m.go --
+package m
+
+import (
+	_ "example.net/deleted"
+	_ "example.net/lazy"
+)
+
+-- d1/go.mod --
+module example.net/deleted
+
+go 1.17
+-- d1/deleted.go --
+package deleted
+-- d2/go.mod --
+module example.net/deleted
+
+go 1.17
+-- d2/README --
+There is no longer a Go package here.
+
+-- lazy/go.mod --
+module example.net/lazy
+
+go 1.17
+
+require example.net/pruned v0.1.0
+-- lazy/lazy.go --
+package lazy
+
+-- pruned/go.mod --
+module example.net/pruned
+
+go 1.17
+
+require example.net/deleted v0.2.0
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_implicit.txt b/src/cmd/go/testdata/script/mod_tidy_compat_implicit.txt
new file mode 100644
index 00000000000..186a3f8e672
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_implicit.txt
@@ -0,0 +1,129 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# For this module, Go 1.16 selects the same versions of all explicit dependencies
+# as Go 1.17 does. However, Go 1.16 selects a higher version of an *implicit*
+# dependency, imported by a test of one of the (external) imported packages.
+# As a result, Go 1.16 also needs checksums for the module sources for that higher
+# version.
+#
+# The Go 1.16 module graph looks like:
+#
+# m ---- lazy v0.1.0 ---- incompatible v1.0.0
+#         |
+#         + ------------- requireincompatible v0.1.0 ---- incompatible v2.0.0+incompatible
+#
+# The Go 1.17 module graph is the same except that the dependencies of
+# requireincompatible are pruned out (because the module that requires
+# it — lazy v0.1.0 — specifies 'go 1.17', and it is not otherwise relevant to
+# the main module).
+
+# 'go mod tidy' should by default diagnose the difference in dependencies as an
+# error, with useful suggestions about how to resolve it.
+
+cp go.mod go.mod.orig
+! go mod tidy
+stderr '^example\.com/m imports\n\texample\.net/lazy tested by\n\texample\.net/lazy.test imports\n\texample\.com/retract/incompatible loaded from example\.com/retract/incompatible@v1\.0\.0,\n\tbut go 1\.16 would select v2\.0\.0\+incompatible\n\n'
+stderr '\n\nTo upgrade to the versions selected by go 1\.16:\n\tgo mod tidy -go=1\.16 && go mod tidy -go=1\.17\nIf reproducibility with go 1.16 is not needed:\n\tgo mod tidy -compat=1.17\nFor other options, see:\n\thttps://golang\.org/doc/modules/pruning\n'
+
+cmp go.mod go.mod.orig
+
+# The suggested '-compat' flag to ignore differences should silence the error
+# and leave go.mod unchanged, resulting in checksum errors when Go 1.16 tries
+# to load a module pruned out by Go 1.17.
+
+go mod tidy -compat=1.17
+! stderr .
+cmp go.mod go.mod.orig
+
+go list -deps -test -f $MODFMT all
+stdout '^example\.com/retract/incompatible v1\.0\.0$'
+
+go mod edit -go=1.16
+! go list -deps -test -f $MODFMT all
+
+	# TODO(#46160): -count=1 instead of -count=2.
+stderr -count=2 '^go: example\.net/lazy@v0\.1\.0 requires\n\texample\.com/retract/incompatible@v1\.0\.0: missing go\.sum entry; to add it:\n\tgo mod download example\.com/retract/incompatible$'
+
+
+# If we combine a Go 1.16 go.sum file...
+go mod tidy -go=1.16
+
+# ...with a Go 1.17 go.mod file...
+cp go.mod.orig go.mod
+
+# ...then Go 1.17 no longer works. 😞
+! go list -deps -test -f $MODFMT all
+stderr -count=1 '^can''t load test package: lazy[/\\]lazy_test.go:3:8: missing go\.sum entry for module providing package example\.com/retract/incompatible \(imported by example\.net/lazy\); to add:\n\tgo get -t example.net/lazy@v0\.1\.0$'
+
+
+# However, if we take the union of the go.sum files...
+go list -mod=mod -deps -test all
+cmp go.mod go.mod.orig
+
+# ...then Go 1.17 continues to work...
+go list -deps -test -f $MODFMT all
+stdout '^example\.com/retract/incompatible v1\.0\.0$'
+
+# ...and 1.16 also works(‽), but selects a different version for the
+# external-test dependency.
+go mod edit -go=1.16
+go list -deps -test -f $MODFMT all
+stdout '^example\.com/retract/incompatible v2\.0\.0\+incompatible$'
+
+
+-- go.mod --
+// Module m imports packages from the same versions under Go 1.17
+// as under Go 1.16, but under 1.16 its (implicit) external test dependencies
+// are higher.
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/requireincompatible v0.1.0 => ./requireincompatible
+)
+
+require example.net/lazy v0.1.0
+-- implicit.go --
+package implicit
+
+import _ "example.net/lazy"
+-- lazy/go.mod --
+// Module lazy requires example.com/retract/incompatible v1.0.0.
+//
+// When viewed from the outside it also has a transitive dependency
+// on v2.0.0+incompatible, but in lazy mode that transitive dependency
+// is pruned out.
+module example.net/lazy
+
+go 1.17
+
+exclude example.com/retract/incompatible v2.0.0+incompatible
+
+require (
+	example.com/retract/incompatible v1.0.0
+	example.net/requireincompatible v0.1.0
+)
+-- lazy/lazy.go --
+package lazy
+-- lazy/lazy_test.go --
+package lazy_test
+
+import _ "example.com/retract/incompatible"
+-- requireincompatible/go.mod --
+module example.net/requireincompatible
+
+go 1.15
+
+require example.com/retract/incompatible v2.0.0+incompatible
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_incompatible.txt b/src/cmd/go/testdata/script/mod_tidy_compat_incompatible.txt
new file mode 100644
index 00000000000..ea9e42e87e2
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_incompatible.txt
@@ -0,0 +1,135 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# For this module, Go 1.17 prunes out a (transitive and otherwise-irrelevant)
+# requirement on a retracted higher version of a dependency.
+# However, when Go 1.16 reads the same requirements from the go.mod file,
+# it does not prune out that requirement, and selects the retracted version.
+#
+# The Go 1.16 module graph looks like:
+#
+# m ---- lazy v0.1.0 ---- requireincompatible v0.1.0 ---- incompatible v2.0.0+incompatible
+# |        |
+# + -------+------------- incompatible v1.0.0
+#
+# The Go 1.17 module graph is the same except that the dependencies of
+# requireincompatible are pruned out (because the module that requires
+# it — lazy v0.1.0 — specifies 'go 1.17', and it is not otherwise relevant to
+# the main module).
+
+
+# 'go mod tidy' should by default diagnose the difference in dependencies as an
+# error, with useful suggestions about how to resolve it.
+
+cp go.mod go.mod.orig
+! go mod tidy
+stderr '^example\.com/m imports\n\texample\.net/lazy imports\n\texample\.com/retract/incompatible loaded from example\.com/retract/incompatible@v1\.0\.0,\n\tbut go 1\.16 would select v2\.0\.0\+incompatible\n\n'
+stderr '\n\nTo upgrade to the versions selected by go 1\.16:\n\tgo mod tidy -go=1\.16 && go mod tidy -go=1\.17\nIf reproducibility with go 1\.16 is not needed:\n\tgo mod tidy -compat=1.17\nFor other options, see:\n\thttps://golang\.org/doc/modules/pruning\n'
+
+cmp go.mod go.mod.orig
+
+
+# The suggested '-compat' flag to ignore differences should silence the error
+# and leave go.mod unchanged, resulting in checksum errors when Go 1.16 tries
+# to load a module pruned out by Go 1.17.
+
+go mod tidy -compat=1.17
+! stderr .
+cmp go.mod go.mod.orig
+
+go mod edit -go=1.16
+! go list -f $MODFMT -deps ./...
+	# TODO(#46160): -count=1 instead of -count=2.
+stderr -count=2 '^go: example\.net/lazy@v0\.1\.0 requires\n\texample\.net/requireincompatible@v0\.1\.0 requires\n\texample\.com/retract/incompatible@v2\.0\.0\+incompatible: missing go.sum entry; to add it:\n\tgo mod download example.com/retract/incompatible$'
+
+
+# There are two ways for the module author to bring the two into alignment.
+# One is to *explicitly* 'exclude' the version that is already *implicitly*
+# pruned out under 1.17.
+
+go mod edit -exclude=example.com/retract/incompatible@v2.0.0+incompatible
+go list -f $MODFMT -deps ./...
+stdout '^example.com/retract/incompatible v1\.0\.0$'
+! stdout 'v2\.0\.0'
+
+
+# The other is to explicitly upgrade the version required under Go 1.17
+# to match the version selected by Go 1.16. The commands suggested by
+# 'go mod tidy' should do exactly that.
+
+cp go.mod.orig go.mod
+
+go mod tidy -go=1.16
+go list -f $MODFMT -deps ./...
+stdout '^example.com/retract/incompatible v2\.0\.0\+incompatible$'
+! stdout 'v1\.0\.0'
+
+go mod tidy -go=1.17
+go list -f $MODFMT -deps ./...
+stdout '^example.com/retract/incompatible v2\.0\.0\+incompatible$'
+! stdout 'v1\.0\.0'
+
+go mod edit -go=1.16
+go list -f $MODFMT -deps ./...
+stdout '^example.com/retract/incompatible v2\.0\.0\+incompatible$'
+! stdout 'v1\.0\.0'
+
+
+-- go.mod --
+// Module m indirectly imports a package from
+// example.com/retract/incompatible. Its selected version of
+// that module is lower under Go 1.17 semantics than under Go 1.16.
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/requireincompatible v0.1.0 => ./requireincompatible
+)
+
+require (
+	example.com/retract/incompatible v1.0.0 // indirect
+	example.net/lazy v0.1.0
+)
+-- incompatible.go --
+package incompatible
+
+import _ "example.net/lazy"
+
+-- lazy/go.mod --
+// Module lazy requires example.com/retract/incompatible v1.0.0.
+//
+// When viewed from the outside it also has a transitive dependency
+// on v2.0.0+incompatible, but in lazy mode that transitive dependency
+// is pruned out.
+module example.net/lazy
+
+go 1.17
+
+exclude example.com/retract/incompatible v2.0.0+incompatible
+
+require (
+	example.com/retract/incompatible v1.0.0
+	example.net/requireincompatible v0.1.0
+)
+-- lazy/lazy.go --
+package lazy
+
+import _ "example.com/retract/incompatible"
+
+-- requireincompatible/go.mod --
+module example.net/requireincompatible
+
+go 1.15
+
+require example.com/retract/incompatible v2.0.0+incompatible
diff --git a/src/cmd/go/testdata/script/mod_tidy_compat_irrelevant.txt b/src/cmd/go/testdata/script/mod_tidy_compat_irrelevant.txt
new file mode 100644
index 00000000000..7c22fca6c0f
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_compat_irrelevant.txt
@@ -0,0 +1,99 @@
+# https://golang.org/issue/46141: 'go mod tidy' for a Go 1.17 module should by
+# default preserve enough checksums for the module to be used by Go 1.16.
+#
+# We don't have a copy of Go 1.16 handy, but we can simulate it by editing the
+# 'go' version in the go.mod file to 1.16, without actually updating the
+# requirements to match.
+
+[short] skip
+
+env MODFMT='{{with .Module}}{{.Path}} {{.Version}}{{end}}'
+
+
+# This module selects the same versions in Go 1.16 and 1.17 for all modules
+# that provide packages (or test dependencies of packages) imported by the
+# main module. However, in Go 1.16 it selects a higher version of a
+# transitive module dependency that is not otherwise relevant to the main module.
+# As a result, Go 1.16 needs an additional checksum for the go.mod file of
+# that irrelevant dependency.
+#
+# The Go 1.16 module graph looks like:
+#
+# m ---- lazy v0.1.0 ---- incompatible v1.0.0
+#         |
+#         + ------------- requireincompatible v0.1.0 ---- incompatible v2.0.0+incompatible
+
+cp go.mod go.mod.orig
+go mod tidy
+cmp go.mod go.mod.orig
+
+go list -deps -test -f $MODFMT all
+cp stdout out-117.txt
+
+go mod edit -go=1.16
+go list -deps -test -f $MODFMT all
+cmp stdout out-117.txt
+
+
+# If we explicitly drop compatibility with 1.16, we retain fewer checksums,
+# which gives a cleaner go.sum file but causes 1.16 to fail in readonly mode.
+
+cp go.mod.orig go.mod
+go mod tidy -compat=1.17
+cmp go.mod go.mod.orig
+
+go list -deps -test -f $MODFMT all
+cmp stdout out-117.txt
+
+go mod edit -go=1.16
+! go list -deps -test -f $MODFMT all
+	# TODO(#46160): -count=1 instead of -count=2.
+stderr -count=2 '^go: example.net/lazy@v0.1.0 requires\n\texample.com/retract/incompatible@v1.0.0: missing go.sum entry; to add it:\n\tgo mod download example.com/retract/incompatible$'
+
+
+-- go.mod --
+// Module m imports packages from the same versions under Go 1.17
+// as under Go 1.16, but under 1.16 its (implicit) external test dependencies
+// are higher.
+module example.com/m
+
+go 1.17
+
+replace (
+	example.net/lazy v0.1.0 => ./lazy
+	example.net/requireincompatible v0.1.0 => ./requireincompatible
+)
+
+require example.net/lazy v0.1.0
+-- m.go --
+package m
+
+import _ "example.net/lazy"
+-- lazy/go.mod --
+// Module lazy requires example.com/retract/incompatible v1.0.0.
+//
+// When viewed from the outside it also has a transitive dependency
+// on v2.0.0+incompatible, but in lazy mode that transitive dependency
+// is pruned out.
+module example.net/lazy
+
+go 1.17
+
+exclude example.com/retract/incompatible v2.0.0+incompatible
+
+require (
+	example.com/retract/incompatible v1.0.0
+	example.net/requireincompatible v0.1.0
+)
+-- lazy/lazy.go --
+package lazy
+-- lazy/unimported/unimported.go --
+package unimported
+
+import _ "example.com/retract/incompatible"
+-- requireincompatible/go.mod --
+module example.net/requireincompatible
+
+go 1.15
+
+require example.com/retract/incompatible v2.0.0+incompatible
diff --git a/src/cmd/go/testdata/script/mod_tidy_convergence.txt b/src/cmd/go/testdata/script/mod_tidy_convergence.txt
index 22c8fc66c57..09c46f764bf 100644
--- a/src/cmd/go/testdata/script/mod_tidy_convergence.txt
+++ b/src/cmd/go/testdata/script/mod_tidy_convergence.txt
@@ -90,7 +90,6 @@ cmp go.mod go.mod.postget
 cp go.mod.orig go.mod
 go mod edit -go=1.17 go.mod
 go mod edit -go=1.17 go.mod.tidye
-go mod edit -go=1.17 go.mod.postget
 
 go mod tidy -e
 cmp go.mod go.mod.tidye
@@ -99,7 +98,7 @@ stderr '^example\.net/m imports\n\texample\.net/x: package example\.net/x provid
 
 go get -d example.net/x@v0.1.0 example.net/y@v0.1.0
 go mod tidy
-cmp go.mod go.mod.postget
+cmp go.mod go.mod.postget-117
 
 
 -- go.mod --
@@ -144,6 +143,21 @@ require (
 	example.net/x v0.1.0
 	example.net/y v0.1.0 // indirect
 )
+-- go.mod.postget-117 --
+module example.net/m
+
+go 1.17
+
+replace (
+	example.net/x v0.1.0 => ./x1
+	example.net/x v0.2.0-pre => ./x2-pre
+	example.net/y v0.1.0 => ./y1
+	example.net/y v0.2.0 => ./y2
+)
+
+require example.net/x v0.1.0
+
+require example.net/y v0.1.0 // indirect
 -- m.go --
 package m
 
diff --git a/src/cmd/go/testdata/script/mod_tidy_error.txt b/src/cmd/go/testdata/script/mod_tidy_error.txt
index 395537b1a71..51fc65fa7a8 100644
--- a/src/cmd/go/testdata/script/mod_tidy_error.txt
+++ b/src/cmd/go/testdata/script/mod_tidy_error.txt
@@ -10,8 +10,8 @@ stderr '^issue27063 imports\n\tissue27063/other imports\n\tother.example.com/non
 
 ! go mod vendor
 ! stderr 'package nonexist is not in GOROOT'
-stderr '^issue27063 imports\n\tnonexist.example.com: cannot find module providing package nonexist.example.com'
-stderr '^issue27063 imports\n\tissue27063/other imports\n\tother.example.com/nonexist: cannot find module providing package other.example.com/nonexist'
+stderr '^issue27063 imports\n\tnonexist.example.com: no required module provides package nonexist.example.com; to add it:\n\tgo get nonexist.example.com$'
+stderr '^issue27063 imports\n\tissue27063/other imports\n\tother.example.com/nonexist: no required module provides package other.example.com/nonexist; to add it:\n\tgo get other.example.com/nonexist$'
 
 -- go.mod --
 module issue27063
diff --git a/src/cmd/go/testdata/script/mod_tidy_lazy_self.txt b/src/cmd/go/testdata/script/mod_tidy_lazy_self.txt
new file mode 100644
index 00000000000..9abbabd2ebe
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_lazy_self.txt
@@ -0,0 +1,66 @@
+# Regression test for https://golang.org/issue/46078:
+# 'go mod tidy' should not panic if the main module initially
+# requires an older version of itself.
+
+# A module may require an older version of itself without error. This is
+# inconsistent (the required version is never selected), but we still get
+# a reproducible build list.
+go list -m all
+stdout '^golang.org/issue/46078$'
+
+# 'go mod tidy' should fix this (and not crash).
+go mod tidy
+
+
+# We prune out redundant roots very early on in module loading, and at that
+# point the indirect requirement on example.net/x v0.1.0 appears to be
+# irrelevant. It should be pruned out; when the import of "example.net/x" is
+# later resolved, it should resolve at the latest version (v0.2.0), not the
+# version implied by the (former) misleading requirement on the older version of
+# the main module.
+
+cmp go.mod go.mod.tidy
+
+
+-- go.mod --
+module golang.org/issue/46078
+
+go 1.17
+
+replace (
+	example.net/x v0.1.0 => ./x
+	example.net/x v0.2.0 => ./x
+	golang.org/issue/46078 v0.1.0 => ./old
+)
+
+require golang.org/issue/46078 v0.1.0
+-- go.mod.tidy --
+module golang.org/issue/46078
+
+go 1.17
+
+replace (
+	example.net/x v0.1.0 => ./x
+	example.net/x v0.2.0 => ./x
+	golang.org/issue/46078 v0.1.0 => ./old
+)
+
+require example.net/x v0.2.0
+-- issue46078/issue.go --
+package issue46078
+
+import _ "example.net/x"
+
+-- old/go.mod --
+module golang.org/issue/46078
+
+go 1.17
+
+require example.net/x v0.1.0
+
+-- x/go.mod --
+module example.net/x
+
+go 1.17
+-- x/x.go --
+package x
diff --git a/src/cmd/go/testdata/script/mod_tidy_oldgo.txt b/src/cmd/go/testdata/script/mod_tidy_oldgo.txt
new file mode 100644
index 00000000000..0e88b068a76
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_oldgo.txt
@@ -0,0 +1,21 @@
+# Modules were introduced in Go 1.11, but for various reasons users may
+# decide to declare a (much!) older go version in their go.mod file.
+# Modules with very old versions should not be rejected, and should have
+# the same module-graph semantics as in Go 1.11.
+
+cp go.mod go.mod.orig
+go mod tidy
+cmp go.mod go.mod.orig
+
+-- go.mod --
+module example.com/legacy/go1
+
+go 1.0
+
+require golang.org/x/text v0.3.0
+-- main.go --
+package main
+
+import _ "golang.org/x/text/language"
+
+func main() {}
diff --git a/src/cmd/go/testdata/script/mod_tidy_replace_old.txt b/src/cmd/go/testdata/script/mod_tidy_replace_old.txt
new file mode 100644
index 00000000000..cfd3792600c
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_replace_old.txt
@@ -0,0 +1,34 @@
+# Regression test for https://golang.org/issue/46659.
+#
+# If a 'replace' directive specifies an older-than-selected version of a module,
+# 'go mod tidy' shouldn't try to add that version to the build list to resolve a
+# missing package: it won't be selected, and would cause the module loader to
+# loop indefinitely trying to resolve the package.
+
+cp go.mod go.mod.orig
+
+! go mod tidy
+! stderr panic
+stderr '^golang\.org/issue46659 imports\n\texample\.com/missingpkg/deprecated: package example\.com/missingpkg/deprecated provided by example\.com/missingpkg at latest version v1\.0\.0 but not at required version v1\.0\.1-beta$'
+
+go mod tidy -e
+
+cmp go.mod go.mod.orig
+
+-- go.mod --
+module golang.org/issue46659
+
+go 1.17
+
+replace example.com/missingpkg v1.0.1-alpha => example.com/missingpkg v1.0.0
+
+require example.com/usemissingpre v1.0.0
+
+require example.com/missingpkg v1.0.1-beta // indirect
+-- m.go --
+package m
+
+import (
+	_ "example.com/missingpkg/deprecated"
+	_ "example.com/usemissingpre"
+)
diff --git a/src/cmd/go/testdata/script/mod_tidy_too_new.txt b/src/cmd/go/testdata/script/mod_tidy_too_new.txt
new file mode 100644
index 00000000000..b9c53b510da
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_tidy_too_new.txt
@@ -0,0 +1,57 @@
+# https://golang.org/issue/46142: 'go mod tidy' should error out if the version
+# in the go.mod file is newer than the most recent supported version.
+
+cp go.mod go.mod.orig
+
+
+# If the go.mod file specifies an unsupported Go version, 'go mod tidy' should
+# refuse to edit it: we don't know what a tidy go.mod file for that version
+# would look like.
+
+! go mod tidy
+stderr 'go mod tidy: go.mod file indicates go 2000.0, but maximum supported version is '$goversion'$'
+cmp go.mod go.mod.orig
+
+
+# The -e flag should push past the error and edit the file anyway,
+# but preserve the too-high version.
+
+cp go.mod.orig go.mod
+go mod tidy -e
+stderr 'go mod tidy: go.mod file indicates go 2000.0, but maximum supported version is '$goversion'$'
+cmp go.mod go.mod.tidy
+
+
+# Explicitly switching to a supported version should suppress the error completely.
+
+cp go.mod.orig go.mod
+go mod tidy -go=1.17
+! stderr 'maximum supported version'
+go mod edit -go=1.17 go.mod.tidy
+cmp go.mod go.mod.tidy
+
+
+-- go.mod --
+module example.net/from/the/future
+
+go 2000.0
+
+replace example.net/m v0.0.0 => ./m
+-- go.mod.tidy --
+module example.net/from/the/future
+
+go 2000.0
+
+replace example.net/m v0.0.0 => ./m
+
+require example.net/m v0.0.0
+-- x.go --
+package x
+
+import "example.net/m"
+-- m/go.mod --
+module example.net/m
+
+go 1.17
+-- m/m.go --
+package m
diff --git a/src/cmd/go/testdata/script/mod_tidy_version.txt b/src/cmd/go/testdata/script/mod_tidy_version.txt
index 5441d9cc06f..3bc97bcb1e7 100644
--- a/src/cmd/go/testdata/script/mod_tidy_version.txt
+++ b/src/cmd/go/testdata/script/mod_tidy_version.txt
@@ -32,12 +32,22 @@
 
 cp go.mod go.mod.orig
 
+
 # An invalid argument should be rejected.
 
 ! go mod tidy -go=bananas
-stderr '^go mod: invalid -go option "bananas"; expecting something like "-go 1.17"$'
+stderr '^invalid value "bananas" for flag -go: expecting a Go version like "'$goversion'"$'
 cmp go.mod go.mod.orig
 
+! go mod tidy -go=0.9
+stderr '^invalid value "0.9" for flag -go: expecting a Go version like "'$goversion'"$'
+
+! go mod tidy -go=2000.0
+stderr '^invalid value "2000.0" for flag -go: maximum supported Go version is '$goversion'$'
+
+
+# Supported versions should change the go.mod file to be tidy according to the
+# indicated version.
 
 go mod tidy -go=1.15
 cmp go.mod go.mod.115
@@ -82,8 +92,9 @@ cmpenv go.mod go.mod.latest
 -- go.mod --
 module example.com/m
 
+require example.net/a v0.1.0
+
 require (
-	example.net/a v0.1.0
 	example.net/c v0.1.0 // indirect
 	example.net/d v0.1.0 // indirect
 )
@@ -108,8 +119,9 @@ module example.com/m
 
 go 1.15
 
+require example.net/a v0.1.0
+
 require (
-	example.net/a v0.1.0
 	example.net/c v0.1.0 // indirect
 	example.net/d v0.1.0 // indirect
 )
@@ -129,8 +141,9 @@ module example.com/m
 
 go 1.15
 
+require example.net/a v0.1.0
+
 require (
-	example.net/a v0.1.0
 	example.net/c v0.1.0 // indirect
 	example.net/d v0.2.0 // indirect
 )
@@ -150,10 +163,9 @@ module example.com/m
 
 go 1.16
 
-require (
-	example.net/a v0.1.0
-	example.net/c v0.1.0 // indirect
-)
+require example.net/a v0.1.0
+
+require example.net/c v0.1.0 // indirect
 
 replace (
 	example.net/a v0.1.0 => ./a
@@ -170,8 +182,9 @@ module example.com/m
 
 go 1.17
 
+require example.net/a v0.1.0
+
 require (
-	example.net/a v0.1.0
 	example.net/b v0.1.0 // indirect
 	example.net/c v0.1.0 // indirect
 )
@@ -191,8 +204,9 @@ module example.com/m
 
 go $goversion
 
+require example.net/a v0.1.0
+
 require (
-	example.net/a v0.1.0
 	example.net/b v0.1.0 // indirect
 	example.net/c v0.1.0 // indirect
 )
diff --git a/src/cmd/go/testdata/script/mod_update_sum_readonly.txt b/src/cmd/go/testdata/script/mod_update_sum_readonly.txt
new file mode 100644
index 00000000000..41f12e4084d
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_update_sum_readonly.txt
@@ -0,0 +1,34 @@
+# When finding the latest version of a module, we should not download version
+# contents. Previously, we downloaded .zip files to determine whether a real
+# .mod file was present in order to decide whether +incompatible versions
+# could be "latest".
+#
+# Verifies #47377.
+
+# rsc.io/breaker has two versions, neither of which has a .mod file.
+go list -m -versions rsc.io/breaker
+stdout '^rsc.io/breaker v1.0.0 v2.0.0\+incompatible$'
+go mod download rsc.io/breaker@v1.0.0
+! grep '^go' $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v1.0.0.mod
+go mod download rsc.io/breaker@v2.0.0+incompatible
+! grep '^go' $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v2.0.0+incompatible.mod
+
+# Delete downloaded .zip files.
+go clean -modcache
+
+# Check for updates.
+go list -m -u rsc.io/breaker
+stdout '^rsc.io/breaker v1.0.0 \[v2.0.0\+incompatible\]$'
+
+# We should not have downloaded zips.
+! exists $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v1.0.0.zip
+! exists $GOPATH/pkg/mod/cache/download/rsc.io/breaker/@v/v2.0.0+incompatible.zip
+
+-- go.mod --
+module m
+
+go 1.16
+
+require rsc.io/breaker v1.0.0
+-- go.sum --
+rsc.io/breaker v1.0.0/go.mod h1:s5yxDXvD88U1/ESC23I2FK3Lkv4YIKaB1ij/Hbm805g=
diff --git a/src/cmd/go/testdata/script/mod_vendor_issue46867.txt b/src/cmd/go/testdata/script/mod_vendor_issue46867.txt
new file mode 100644
index 00000000000..38ae87b44a9
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_vendor_issue46867.txt
@@ -0,0 +1,31 @@
+# Regression test for golang.org/issue/46867:
+# 'go mod vendor' on Windows attempted to open and copy
+# files from directories outside of the module.
+
+cd subdir
+go mod vendor
+! exists vendor/example.net/NOTICE
+exists vendor/example.net/m/NOTICE
+
+-- subdir/go.mod --
+module golang.org/issue46867
+
+go 1.17
+
+replace example.net/m v0.1.0 => ./m
+
+require example.net/m v0.1.0
+-- subdir/issue.go --
+package issue
+
+import _ "example.net/m/n"
+-- subdir/m/go.mod --
+module example.net/m
+
+go 1.17
+-- subdir/m/n/n.go --
+package n
+-- subdir/m/NOTICE --
+This notice is in module m and SHOULD be vendored.
+-- subdir/NOTICE --
+This notice is outside of module m and SHOULD NOT be vendored.
diff --git a/src/cmd/go/testdata/script/mod_vendor_redundant_requirement.txt b/src/cmd/go/testdata/script/mod_vendor_redundant_requirement.txt
new file mode 100644
index 00000000000..3f6f5c5276b
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_vendor_redundant_requirement.txt
@@ -0,0 +1,29 @@
+# 'go list -mod=vendor' should succeed even when go.mod contains redundant
+# requirements. Verifies #47565.
+go list -mod=vendor
+
+-- go.mod --
+module m
+
+go 1.17
+
+require example.com/m v0.0.0
+require example.com/m v0.0.0
+
+replace example.com/m v0.0.0 => ./m
+-- m/go.mod --
+module example.com/m
+
+go 1.17
+-- m/m.go --
+package m
+-- use.go --
+package use
+
+import _ "example.com/m"
+-- vendor/example.com/m/m.go --
+package m
+-- vendor/modules.txt --
+# example.com/m v0.0.0 => ./m
+## explicit; go 1.17
+example.com/m
diff --git a/src/cmd/go/testdata/script/mod_vendor_replace.txt b/src/cmd/go/testdata/script/mod_vendor_replace.txt
index 0c1c1d22f5b..1820af62ad8 100644
--- a/src/cmd/go/testdata/script/mod_vendor_replace.txt
+++ b/src/cmd/go/testdata/script/mod_vendor_replace.txt
@@ -36,7 +36,6 @@ module example.com/replace
 
 require rsc.io/quote/v3 v3.0.0
 replace rsc.io/quote/v3 => ./local/not-rsc.io/quote/v3
-
 -- imports.go --
 package replace
 
@@ -64,3 +63,7 @@ require (
 	not-rsc.io/quote/v3 v3.0.0
 )
 replace not-rsc.io/quote/v3 => rsc.io/quote/v3 v3.0.0
+-- multiple-paths/go.sum --
+golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+rsc.io/quote/v3 v3.0.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=
+rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
diff --git a/src/cmd/go/testdata/script/mod_vendor_trimpath.txt b/src/cmd/go/testdata/script/mod_vendor_trimpath.txt
index 5451aa773c8..d9d9d988974 100644
--- a/src/cmd/go/testdata/script/mod_vendor_trimpath.txt
+++ b/src/cmd/go/testdata/script/mod_vendor_trimpath.txt
@@ -29,8 +29,12 @@ stdout '^example.com/stack@v1.0.0/stack.go$'
 -- go.mod --
 module example.com/main
 
-require example.com/stack v1.0.0
+go 1.17
 
+require example.com/stack v1.0.0
+-- go.sum --
+example.com/stack v1.0.0 h1:IEDLeew5NytZ8vrgCF/QVem3H3SR3QMttdu9HfJvk9I=
+example.com/stack v1.0.0/go.mod h1:7wFEbaV5e5O7wJ8aBdqQOR//UXppm/pwnwziMKViuI4=
 -- main.go --
 package main
 
diff --git a/src/cmd/go/testdata/script/mod_vendor_unused_only.txt b/src/cmd/go/testdata/script/mod_vendor_unused_only.txt
index 839c6453cf8..accd9f373de 100644
--- a/src/cmd/go/testdata/script/mod_vendor_unused_only.txt
+++ b/src/cmd/go/testdata/script/mod_vendor_unused_only.txt
@@ -12,6 +12,8 @@ module example.com/m
 go 1.14
 
 require example.com v1.0.0 // indirect
+-- go.sum --
+example.com v1.0.0/go.mod h1:WRiieAqDBb1hVdDXLLdxNtCDWNfehn7FWyPC5Oz2vB4=
 -- go1.14-modules.txt --
 # example.com v1.0.0
 ## explicit
diff --git a/src/cmd/go/testdata/script/mod_verify.txt b/src/cmd/go/testdata/script/mod_verify.txt
index b5106659a9a..f02d15aa289 100644
--- a/src/cmd/go/testdata/script/mod_verify.txt
+++ b/src/cmd/go/testdata/script/mod_verify.txt
@@ -39,11 +39,6 @@ stderr 'go.mod: checksum mismatch'
 
 # go.sum should be created and updated automatically.
 rm go.sum
-go mod graph
-exists go.sum
-grep '^rsc.io/quote v1.1.0/go.mod ' go.sum
-! grep '^rsc.io/quote v1.1.0 ' go.sum
-
 go mod tidy
 grep '^rsc.io/quote v1.1.0/go.mod ' go.sum
 grep '^rsc.io/quote v1.1.0 ' go.sum
diff --git a/src/cmd/go/testdata/script/modfile_flag.txt b/src/cmd/go/testdata/script/modfile_flag.txt
index 0ad08808178..baf25d31b89 100644
--- a/src/cmd/go/testdata/script/modfile_flag.txt
+++ b/src/cmd/go/testdata/script/modfile_flag.txt
@@ -24,6 +24,11 @@ stdout '^go.alt.mod$'
 go mod edit -require rsc.io/quote@v1.5.2
 grep rsc.io/quote go.alt.mod
 
+# 'go list -m' should add sums to the alternate go.sum.
+go list -m -mod=mod all
+grep '^rsc.io/quote v1.5.2/go.mod ' go.alt.sum
+! grep '^rsc.io/quote v1.5.2 ' go.alt.sum
+
 # other 'go mod' commands should work. 'go mod vendor' is tested later.
 go mod download rsc.io/quote
 go mod graph
diff --git a/src/cmd/go/testdata/script/test_race_install_cgo.txt b/src/cmd/go/testdata/script/test_race_install_cgo.txt
index 3f4eb90e3f6..e1fe4f2acea 100644
--- a/src/cmd/go/testdata/script/test_race_install_cgo.txt
+++ b/src/cmd/go/testdata/script/test_race_install_cgo.txt
@@ -2,8 +2,6 @@
 
 [!race] skip
 
-[!darwin] ! stale cmd/cgo  # The darwin builders are spuriously stale; see #33598.
-
 env GOBIN=$WORK/bin
 go install m/mtime m/sametime
 
diff --git a/src/cmd/go/testdata/script/test_script_cmdcd.txt b/src/cmd/go/testdata/script/test_script_cmdcd.txt
new file mode 100644
index 00000000000..6e6f67e13d0
--- /dev/null
+++ b/src/cmd/go/testdata/script/test_script_cmdcd.txt
@@ -0,0 +1,13 @@
+# Tests that after a cd command, where usually the UNIX path separator is used,
+# a match against $PWD does not fail on Windows.
+
+cd $WORK/a/b/c/pkg
+
+go list -find -f {{.Root}}
+stdout $PWD
+
+-- $WORK/a/b/c/pkg/go.mod --
+module pkg
+
+-- $WORK/a/b/c/pkg/pkg.go --
+package pkg
diff --git a/src/cmd/go/testdata/script/toolexec.txt b/src/cmd/go/testdata/script/toolexec.txt
index 4f26da6d26b..bb86467942b 100644
--- a/src/cmd/go/testdata/script/toolexec.txt
+++ b/src/cmd/go/testdata/script/toolexec.txt
@@ -3,6 +3,12 @@
 # Build our simple toolexec program.
 go build ./cmd/mytool
 
+# Use an ephemeral build cache so that our toolexec output is not cached
+# for any stale standard-library dependencies.
+#
+# TODO(#27628): This should not be necessary.
+env GOCACHE=$WORK/gocache
+
 # Build the main package with our toolexec program. For each action, it will
 # print the tool's name and the TOOLEXEC_IMPORTPATH value. We expect to compile
 # each package once, and link the main package once.
diff --git a/src/cmd/gofmt/doc.go b/src/cmd/gofmt/doc.go
index 68476e7d443..e3406655941 100644
--- a/src/cmd/gofmt/doc.go
+++ b/src/cmd/gofmt/doc.go
@@ -26,9 +26,6 @@ The flags are:
 		Do not print reformatted sources to standard output.
 		If a file's formatting is different from gofmt's, print its name
 		to standard output.
-	-G
-		Allow generic code, using type parameters.
-		See golang.org/issues/43651 for more information.
 	-r rule
 		Apply the rewrite rule to the source before reformatting.
 	-s
diff --git a/src/cmd/gofmt/gofmt_test.go b/src/cmd/gofmt/gofmt_test.go
index f0d3f8780f4..9ef7676214c 100644
--- a/src/cmd/gofmt/gofmt_test.go
+++ b/src/cmd/gofmt/gofmt_test.go
@@ -54,8 +54,6 @@ func gofmtFlags(filename string, maxLines int) string {
 	return ""
 }
 
-var typeParamsEnabled = false
-
 func runTest(t *testing.T, in, out string) {
 	// process flags
 	*simplifyAST = false
@@ -78,11 +76,6 @@ func runTest(t *testing.T, in, out string) {
 		case "-stdin":
 			// fake flag - pretend input is from stdin
 			stdin = true
-		case "-G":
-			// fake flag - test is for generic code
-			if !typeParamsEnabled {
-				return
-			}
 		default:
 			t.Errorf("unrecognized flag name: %s", name)
 		}
diff --git a/src/cmd/gofmt/testdata/typeparams.golden b/src/cmd/gofmt/testdata/typeparams.golden
index 35f08d13792..f71bd130db4 100644
--- a/src/cmd/gofmt/testdata/typeparams.golden
+++ b/src/cmd/gofmt/testdata/typeparams.golden
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//gofmt -G
+//gofmt
 
 package typeparams
 
diff --git a/src/cmd/gofmt/testdata/typeparams.input b/src/cmd/gofmt/testdata/typeparams.input
index 7f3212c8e4a..5d4c53d9f76 100644
--- a/src/cmd/gofmt/testdata/typeparams.input
+++ b/src/cmd/gofmt/testdata/typeparams.input
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//gofmt -G
+//gofmt
 
 package typeparams
 
diff --git a/src/cmd/internal/dwarf/dwarf.go b/src/cmd/internal/dwarf/dwarf.go
index ec441c2bcb6..860c7d6c0d9 100644
--- a/src/cmd/internal/dwarf/dwarf.go
+++ b/src/cmd/internal/dwarf/dwarf.go
@@ -1266,7 +1266,7 @@ func PutAbstractFunc(ctxt Context, s *FnState) error {
 // its corresponding 'abstract' DIE (containing location-independent
 // attributes such as name, type, etc). Inlined subroutine DIEs can
 // have other inlined subroutine DIEs as children.
-func putInlinedFunc(ctxt Context, s *FnState, callersym Sym, callIdx int) error {
+func putInlinedFunc(ctxt Context, s *FnState, callIdx int) error {
 	ic := s.InlCalls.Calls[callIdx]
 	callee := ic.AbsFunSym
 
@@ -1277,7 +1277,7 @@ func putInlinedFunc(ctxt Context, s *FnState, callersym Sym, callIdx int) error
 	Uleb128put(ctxt, s.Info, int64(abbrev))
 
 	if logDwarf {
-		ctxt.Logf("putInlinedFunc(caller=%v,callee=%v,abbrev=%d)\n", callersym, callee, abbrev)
+		ctxt.Logf("putInlinedFunc(callee=%v,abbrev=%d)\n", callee, abbrev)
 	}
 
 	// Abstract origin.
@@ -1312,8 +1312,7 @@ func putInlinedFunc(ctxt Context, s *FnState, callersym Sym, callIdx int) error
 
 	// Children of this inline.
 	for _, sib := range inlChildren(callIdx, &s.InlCalls) {
-		absfn := s.InlCalls.Calls[sib].AbsFunSym
-		err := putInlinedFunc(ctxt, s, absfn, sib)
+		err := putInlinedFunc(ctxt, s, sib)
 		if err != nil {
 			return err
 		}
@@ -1354,8 +1353,7 @@ func PutConcreteFunc(ctxt Context, s *FnState) error {
 
 	// Inlined subroutines.
 	for _, sib := range inlChildren(-1, &s.InlCalls) {
-		absfn := s.InlCalls.Calls[sib].AbsFunSym
-		err := putInlinedFunc(ctxt, s, absfn, sib)
+		err := putInlinedFunc(ctxt, s, sib)
 		if err != nil {
 			return err
 		}
@@ -1402,8 +1400,7 @@ func PutDefaultFunc(ctxt Context, s *FnState) error {
 
 	// Inlined subroutines.
 	for _, sib := range inlChildren(-1, &s.InlCalls) {
-		absfn := s.InlCalls.Calls[sib].AbsFunSym
-		err := putInlinedFunc(ctxt, s, absfn, sib)
+		err := putInlinedFunc(ctxt, s, sib)
 		if err != nil {
 			return err
 		}
diff --git a/src/cmd/internal/goobj/builtinlist.go b/src/cmd/internal/goobj/builtinlist.go
index 9f248137daa..608c0d72223 100644
--- a/src/cmd/internal/goobj/builtinlist.go
+++ b/src/cmd/internal/goobj/builtinlist.go
@@ -33,6 +33,7 @@ var builtins = [...]struct {
 	{"runtime.goPanicSlice3BU", 1},
 	{"runtime.goPanicSlice3C", 1},
 	{"runtime.goPanicSlice3CU", 1},
+	{"runtime.goPanicSliceConvert", 1},
 	{"runtime.printbool", 1},
 	{"runtime.printfloat", 1},
 	{"runtime.printint", 1},
@@ -129,6 +130,8 @@ var builtins = [...]struct {
 	{"runtime.makeslice64", 1},
 	{"runtime.makeslicecopy", 1},
 	{"runtime.growslice", 1},
+	{"runtime.unsafeslice", 1},
+	{"runtime.unsafeslice64", 1},
 	{"runtime.memmove", 1},
 	{"runtime.memclrNoHeapPointers", 1},
 	{"runtime.memclrHasPointers", 1},
@@ -203,7 +206,9 @@ var builtins = [...]struct {
 	{"runtime.newproc", 1},
 	{"runtime.panicoverflow", 1},
 	{"runtime.sigpanic", 1},
-	{"runtime.gcWriteBarrier", 0},
+	{"runtime.gcWriteBarrier", 1},
+	{"runtime.duffzero", 1},
+	{"runtime.duffcopy", 1},
 	{"runtime.morestack", 0},
 	{"runtime.morestackc", 0},
 	{"runtime.morestack_noctxt", 0},
diff --git a/src/cmd/internal/goobj/mkbuiltin.go b/src/cmd/internal/goobj/mkbuiltin.go
index 18b969586cc..c9995fcedef 100644
--- a/src/cmd/internal/goobj/mkbuiltin.go
+++ b/src/cmd/internal/goobj/mkbuiltin.go
@@ -151,7 +151,9 @@ var fextras = [...]extra{
 	{"sigpanic", 1},
 
 	// compiler backend inserted calls
-	{"gcWriteBarrier", 0}, // asm function, ABI0
+	{"gcWriteBarrier", 1},
+	{"duffzero", 1},
+	{"duffcopy", 1},
 
 	// assembler backend inserted calls
 	{"morestack", 0},        // asm function, ABI0
diff --git a/src/cmd/internal/moddeps/moddeps_test.go b/src/cmd/internal/moddeps/moddeps_test.go
index ba574f40049..56c3b2585c7 100644
--- a/src/cmd/internal/moddeps/moddeps_test.go
+++ b/src/cmd/internal/moddeps/moddeps_test.go
@@ -5,6 +5,7 @@
 package moddeps_test
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"internal/testenv"
@@ -68,7 +69,7 @@ func TestAllDependencies(t *testing.T) {
 
 			// There is no vendor directory, so the module must have no dependencies.
 			// Check that the list of active modules contains only the main module.
-			cmd := exec.Command(goBin, "list", "-mod=mod", "-m", "all")
+			cmd := exec.Command(goBin, "list", "-mod=readonly", "-m", "all")
 			cmd.Env = append(os.Environ(), "GO111MODULE=on")
 			cmd.Dir = m.Dir
 			cmd.Stderr = new(strings.Builder)
@@ -123,10 +124,38 @@ func TestAllDependencies(t *testing.T) {
 		t.Skip("skipping because a diff command with support for --recursive and --unified flags is unavailable")
 	}
 
+	// We're going to check the standard modules for tidiness, so we need a usable
+	// GOMODCACHE. If the default directory doesn't exist, use a temporary
+	// directory instead. (That can occur, for example, when running under
+	// run.bash with GO_TEST_SHORT=0: run.bash sets GOPATH=/nonexist-gopath, and
+	// GO_TEST_SHORT=0 causes it to run this portion of the test.)
+	var modcacheEnv []string
+	{
+		out, err := exec.Command(goBin, "env", "GOMODCACHE").Output()
+		if err != nil {
+			t.Fatalf("%s env GOMODCACHE: %v", goBin, err)
+		}
+		modcacheOk := false
+		if gomodcache := string(bytes.TrimSpace(out)); gomodcache != "" {
+			if _, err := os.Stat(gomodcache); err == nil {
+				modcacheOk = true
+			}
+		}
+		if !modcacheOk {
+			modcacheEnv = []string{
+				"GOMODCACHE=" + t.TempDir(),
+				"GOFLAGS=" + os.Getenv("GOFLAGS") + " -modcacherw", // Allow t.TempDir() to clean up subdirectories.
+			}
+		}
+	}
+
 	// Build the bundle binary at the golang.org/x/tools
 	// module version specified in GOROOT/src/cmd/go.mod.
 	bundleDir := t.TempDir()
-	r := runner{Dir: filepath.Join(runtime.GOROOT(), "src/cmd")}
+	r := runner{
+		Dir: filepath.Join(runtime.GOROOT(), "src/cmd"),
+		Env: append(os.Environ(), modcacheEnv...),
+	}
 	r.run(t, goBin, "build", "-mod=readonly", "-o", bundleDir, "golang.org/x/tools/cmd/bundle")
 
 	var gorootCopyDir string
@@ -160,7 +189,7 @@ func TestAllDependencies(t *testing.T) {
 			}
 			r := runner{
 				Dir: filepath.Join(gorootCopyDir, rel),
-				Env: append(os.Environ(),
+				Env: append(append(os.Environ(), modcacheEnv...),
 					// Set GOROOT.
 					"GOROOT="+gorootCopyDir,
 					// Explicitly override PWD and clear GOROOT_FINAL so that GOROOT=gorootCopyDir is definitely used.
@@ -227,7 +256,7 @@ func makeGOROOTCopy(t *testing.T) string {
 		if err != nil {
 			return err
 		}
-		if src == filepath.Join(runtime.GOROOT(), ".git") {
+		if info.IsDir() && src == filepath.Join(runtime.GOROOT(), ".git") {
 			return filepath.SkipDir
 		}
 
@@ -237,9 +266,8 @@ func makeGOROOTCopy(t *testing.T) string {
 		}
 		dst := filepath.Join(gorootCopyDir, rel)
 
-		switch src {
-		case filepath.Join(runtime.GOROOT(), "bin"),
-			filepath.Join(runtime.GOROOT(), "pkg"):
+		if info.IsDir() && (src == filepath.Join(runtime.GOROOT(), "bin") ||
+			src == filepath.Join(runtime.GOROOT(), "pkg")) {
 			// If the OS supports symlinks, use them instead
 			// of copying the bin and pkg directories.
 			if err := os.Symlink(src, dst); err == nil {
@@ -414,7 +442,7 @@ func findGorootModules(t *testing.T) []gorootModule {
 			if info.IsDir() && (info.Name() == "vendor" || info.Name() == "testdata") {
 				return filepath.SkipDir
 			}
-			if path == filepath.Join(runtime.GOROOT(), "pkg") {
+			if info.IsDir() && path == filepath.Join(runtime.GOROOT(), "pkg") {
 				// GOROOT/pkg contains generated artifacts, not source code.
 				//
 				// In https://golang.org/issue/37929 it was observed to somehow contain
@@ -422,7 +450,7 @@ func findGorootModules(t *testing.T) []gorootModule {
 				// running time of this test anyway.)
 				return filepath.SkipDir
 			}
-			if strings.HasPrefix(info.Name(), "_") || strings.HasPrefix(info.Name(), ".") {
+			if info.IsDir() && (strings.HasPrefix(info.Name(), "_") || strings.HasPrefix(info.Name(), ".")) {
 				// _ and . prefixed directories can be used for internal modules
 				// without a vendor directory that don't contribute to the build
 				// but might be used for example as code generators.
@@ -457,8 +485,31 @@ func findGorootModules(t *testing.T) []gorootModule {
 			goroot.modules = append(goroot.modules, m)
 			return nil
 		})
-	})
+		if goroot.err != nil {
+			return
+		}
 
+		// knownGOROOTModules is a hard-coded list of modules that are known to exist in GOROOT.
+		// If findGorootModules doesn't find a module, it won't be covered by tests at all,
+		// so make sure at least these modules are found. See issue 46254. If this list
+		// becomes a nuisance to update, can be replaced with len(goroot.modules) check.
+		knownGOROOTModules := [...]string{
+			"std",
+			"cmd",
+			"misc",
+			"test/bench/go1",
+		}
+		var seen = make(map[string]bool) // Key is module path.
+		for _, m := range goroot.modules {
+			seen[m.Path] = true
+		}
+		for _, m := range knownGOROOTModules {
+			if !seen[m] {
+				goroot.err = fmt.Errorf("findGorootModules didn't find the well-known module %q", m)
+				break
+			}
+		}
+	})
 	if goroot.err != nil {
 		t.Fatal(goroot.err)
 	}
diff --git a/src/cmd/internal/obj/arm/asm5.go b/src/cmd/internal/obj/arm/asm5.go
index ccf5f9e7f8d..7b1682776e5 100644
--- a/src/cmd/internal/obj/arm/asm5.go
+++ b/src/cmd/internal/obj/arm/asm5.go
@@ -355,11 +355,10 @@ var oprange [ALAST & obj.AMask][]Optab
 var xcmp [C_GOK + 1][C_GOK + 1]bool
 
 var (
-	deferreturn *obj.LSym
-	symdiv      *obj.LSym
-	symdivu     *obj.LSym
-	symmod      *obj.LSym
-	symmodu     *obj.LSym
+	symdiv  *obj.LSym
+	symdivu *obj.LSym
+	symmod  *obj.LSym
+	symmodu *obj.LSym
 )
 
 // Note about encoding: Prog.scond holds the condition encoding,
@@ -1219,8 +1218,6 @@ func buildop(ctxt *obj.Link) {
 		return
 	}
 
-	deferreturn = ctxt.LookupABI("runtime.deferreturn", obj.ABIInternal)
-
 	symdiv = ctxt.Lookup("runtime._div")
 	symdivu = ctxt.Lookup("runtime._divu")
 	symmod = ctxt.Lookup("runtime._mod")
diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 575436d764a..d99afa3d276 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -3536,27 +3536,25 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		o1 = c.oprrr(p, p.As)
 
 		cond := int(p.From.Reg)
-		if cond < COND_EQ || cond > COND_NV {
+		// AL and NV are not allowed for CINC/CINV/CNEG/CSET/CSETM instructions
+		if cond < COND_EQ || cond > COND_NV || (cond == COND_AL || cond == COND_NV) && p.From3Type() == obj.TYPE_NONE {
 			c.ctxt.Diag("invalid condition: %v", p)
 		} else {
 			cond -= COND_EQ
 		}
 
 		r := int(p.Reg)
-		var rf int
-		if r != 0 {
-			if p.From3Type() == obj.TYPE_NONE {
-				/* CINC/CINV/CNEG */
-				rf = r
-				cond ^= 1
-			} else {
-				rf = int(p.GetFrom3().Reg) /* CSEL */
+		var rf int = r
+		if p.From3Type() == obj.TYPE_NONE {
+			/* CINC/CINV/CNEG or CSET/CSETM*/
+			if r == 0 {
+				/* CSET/CSETM */
+				rf = REGZERO
+				r = rf
 			}
-		} else {
-			/* CSET */
-			rf = REGZERO
-			r = rf
 			cond ^= 1
+		} else {
+			rf = int(p.GetFrom3().Reg) /* CSEL */
 		}
 
 		rt := int(p.To.Reg)
@@ -4335,8 +4333,10 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if p.To.Reg == REG_RSP && isADDSop(p.As) {
 			c.ctxt.Diag("illegal destination register: %v\n", p)
 		}
+		lsl0 := LSL0_64
 		if isADDWop(p.As) || isANDWop(p.As) {
 			o1 = c.omovconst(AMOVW, p, &p.From, REGTMP)
+			lsl0 = LSL0_32
 		} else {
 			o1 = c.omovconst(AMOVD, p, &p.From, REGTMP)
 		}
@@ -4352,7 +4352,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if p.To.Reg == REGSP || r == REGSP {
 			o2 = c.opxrrr(p, p.As, false)
 			o2 |= REGTMP & 31 << 16
-			o2 |= LSL0_64
+			o2 |= uint32(lsl0)
 		} else {
 			o2 = c.oprrr(p, p.As)
 			o2 |= REGTMP & 31 << 16 /* shift is 0 */
diff --git a/src/cmd/internal/obj/arm64/obj7.go b/src/cmd/internal/obj/arm64/obj7.go
index e41fb3bb753..31b7c432451 100644
--- a/src/cmd/internal/obj/arm64/obj7.go
+++ b/src/cmd/internal/obj/arm64/obj7.go
@@ -52,7 +52,7 @@ var complements = []obj.As{
 }
 
 func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
-	// MOV	g_stackguard(g), R1
+	// MOV	g_stackguard(g), RT1
 	p = obj.Appendp(p, c.newprog)
 
 	p.As = AMOVD
@@ -63,7 +63,7 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 		p.From.Offset = 3 * int64(c.ctxt.Arch.PtrSize) // G.stackguard1
 	}
 	p.To.Type = obj.TYPE_REG
-	p.To.Reg = REG_R1
+	p.To.Reg = REGRT1
 
 	// Mark the stack bound check and morestack call async nonpreemptible.
 	// If we get preempted here, when resumed the preemption request is
@@ -74,25 +74,25 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	q := (*obj.Prog)(nil)
 	if framesize <= objabi.StackSmall {
 		// small stack: SP < stackguard
-		//	MOV	SP, R2
-		//	CMP	stackguard, R2
+		//	MOV	SP, RT2
+		//	CMP	stackguard, RT2
 		p = obj.Appendp(p, c.newprog)
 
 		p.As = AMOVD
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = REGSP
 		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_R2
+		p.To.Reg = REGRT2
 
 		p = obj.Appendp(p, c.newprog)
 		p.As = ACMP
 		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_R1
-		p.Reg = REG_R2
+		p.From.Reg = REGRT1
+		p.Reg = REGRT2
 	} else if framesize <= objabi.StackBig {
 		// large stack: SP-framesize < stackguard-StackSmall
-		//	SUB	$(framesize-StackSmall), SP, R2
-		//	CMP	stackguard, R2
+		//	SUB	$(framesize-StackSmall), SP, RT2
+		//	CMP	stackguard, RT2
 		p = obj.Appendp(p, c.newprog)
 
 		p.As = ASUB
@@ -100,13 +100,13 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 		p.From.Offset = int64(framesize) - objabi.StackSmall
 		p.Reg = REGSP
 		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_R2
+		p.To.Reg = REGRT2
 
 		p = obj.Appendp(p, c.newprog)
 		p.As = ACMP
 		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_R1
-		p.Reg = REG_R2
+		p.From.Reg = REGRT1
+		p.Reg = REGRT2
 	} else {
 		// Such a large stack we need to protect against underflow.
 		// The runtime guarantees SP > objabi.StackBig, but
@@ -115,10 +115,10 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 		// stack guard to incorrectly succeed. We explicitly
 		// guard against underflow.
 		//
-		//	SUBS	$(framesize-StackSmall), SP, R2
+		//	SUBS	$(framesize-StackSmall), SP, RT2
 		//	// On underflow, jump to morestack
 		//	BLO	label_of_call_to_morestack
-		//	CMP	stackguard, R2
+		//	CMP	stackguard, RT2
 
 		p = obj.Appendp(p, c.newprog)
 		p.As = ASUBS
@@ -126,7 +126,7 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 		p.From.Offset = int64(framesize) - objabi.StackSmall
 		p.Reg = REGSP
 		p.To.Type = obj.TYPE_REG
-		p.To.Reg = REG_R2
+		p.To.Reg = REGRT2
 
 		p = obj.Appendp(p, c.newprog)
 		q = p
@@ -136,8 +136,8 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 		p = obj.Appendp(p, c.newprog)
 		p.As = ACMP
 		p.From.Type = obj.TYPE_REG
-		p.From.Reg = REG_R1
-		p.Reg = REG_R2
+		p.From.Reg = REGRT1
+		p.Reg = REGRT2
 	}
 
 	// BLS	do-morestack
@@ -161,17 +161,20 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	pcdata := c.ctxt.EmitEntryStackMap(c.cursym, spfix, c.newprog)
 	pcdata = c.ctxt.StartUnsafePoint(pcdata, c.newprog)
 
+	if q != nil {
+		q.To.SetTarget(pcdata)
+	}
+	bls.To.SetTarget(pcdata)
+
+	spill := c.cursym.Func().SpillRegisterArgs(pcdata, c.newprog)
+
 	// MOV	LR, R3
-	movlr := obj.Appendp(pcdata, c.newprog)
+	movlr := obj.Appendp(spill, c.newprog)
 	movlr.As = AMOVD
 	movlr.From.Type = obj.TYPE_REG
 	movlr.From.Reg = REGLINK
 	movlr.To.Type = obj.TYPE_REG
 	movlr.To.Reg = REG_R3
-	if q != nil {
-		q.To.SetTarget(movlr)
-	}
-	bls.To.SetTarget(movlr)
 
 	debug := movlr
 	if false {
@@ -196,7 +199,8 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	}
 	call.To.Sym = c.ctxt.Lookup(morestack)
 
-	pcdata = c.ctxt.EndUnsafePoint(call, c.newprog, -1)
+	unspill := c.cursym.Func().UnspillRegisterArgs(call, c.newprog)
+	pcdata = c.ctxt.EndUnsafePoint(unspill, c.newprog, -1)
 
 	// B	start
 	jmp := obj.Appendp(pcdata, c.newprog)
@@ -321,9 +325,9 @@ func (c *ctxt7) rewriteToUseGot(p *obj.Prog) {
 		//     CALL REGTMP
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
-			sym = c.ctxt.Lookup("runtime.duffzero")
+			sym = c.ctxt.LookupABI("runtime.duffzero", obj.ABIInternal)
 		} else {
-			sym = c.ctxt.Lookup("runtime.duffcopy")
+			sym = c.ctxt.LookupABI("runtime.duffcopy", obj.ABIInternal)
 		}
 		offset := p.To.Offset
 		p.As = AMOVD
@@ -631,38 +635,38 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 			if c.cursym.Func().Text.From.Sym.Wrapper() {
 				// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
 				//
-				//	MOV  g_panic(g), R1
+				//	MOV  g_panic(g), RT1
 				//	CBNZ checkargp
 				// end:
 				//	NOP
 				// ... function body ...
 				// checkargp:
-				//	MOV  panic_argp(R1), R2
-				//	ADD  $(autosize+8), RSP, R3
-				//	CMP  R2, R3
+				//	MOV  panic_argp(RT1), RT2
+				//	ADD  $(autosize+8), RSP, R20
+				//	CMP  RT2, R20
 				//	BNE  end
-				//	ADD  $8, RSP, R4
-				//	MOVD R4, panic_argp(R1)
+				//	ADD  $8, RSP, R20
+				//	MOVD R20, panic_argp(RT1)
 				//	B    end
 				//
 				// The NOP is needed to give the jumps somewhere to land.
 				// It is a liblink NOP, not an ARM64 NOP: it encodes to 0 instruction bytes.
 				q = q1
 
-				// MOV g_panic(g), R1
+				// MOV g_panic(g), RT1
 				q = obj.Appendp(q, c.newprog)
 				q.As = AMOVD
 				q.From.Type = obj.TYPE_MEM
 				q.From.Reg = REGG
 				q.From.Offset = 4 * int64(c.ctxt.Arch.PtrSize) // G.panic
 				q.To.Type = obj.TYPE_REG
-				q.To.Reg = REG_R1
+				q.To.Reg = REGRT1
 
-				// CBNZ R1, checkargp
+				// CBNZ RT1, checkargp
 				cbnz := obj.Appendp(q, c.newprog)
 				cbnz.As = ACBNZ
 				cbnz.From.Type = obj.TYPE_REG
-				cbnz.From.Reg = REG_R1
+				cbnz.From.Reg = REGRT1
 				cbnz.To.Type = obj.TYPE_BRANCH
 
 				// Empty branch target at the top of the function body
@@ -674,33 +678,33 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				for last = end; last.Link != nil; last = last.Link {
 				}
 
-				// MOV panic_argp(R1), R2
+				// MOV panic_argp(RT1), RT2
 				mov := obj.Appendp(last, c.newprog)
 				mov.As = AMOVD
 				mov.From.Type = obj.TYPE_MEM
-				mov.From.Reg = REG_R1
+				mov.From.Reg = REGRT1
 				mov.From.Offset = 0 // Panic.argp
 				mov.To.Type = obj.TYPE_REG
-				mov.To.Reg = REG_R2
+				mov.To.Reg = REGRT2
 
 				// CBNZ branches to the MOV above
 				cbnz.To.SetTarget(mov)
 
-				// ADD $(autosize+8), SP, R3
+				// ADD $(autosize+8), SP, R20
 				q = obj.Appendp(mov, c.newprog)
 				q.As = AADD
 				q.From.Type = obj.TYPE_CONST
 				q.From.Offset = int64(c.autosize) + 8
 				q.Reg = REGSP
 				q.To.Type = obj.TYPE_REG
-				q.To.Reg = REG_R3
+				q.To.Reg = REG_R20
 
-				// CMP R2, R3
+				// CMP RT2, R20
 				q = obj.Appendp(q, c.newprog)
 				q.As = ACMP
 				q.From.Type = obj.TYPE_REG
-				q.From.Reg = REG_R2
-				q.Reg = REG_R3
+				q.From.Reg = REGRT2
+				q.Reg = REG_R20
 
 				// BNE end
 				q = obj.Appendp(q, c.newprog)
@@ -708,22 +712,22 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				q.To.Type = obj.TYPE_BRANCH
 				q.To.SetTarget(end)
 
-				// ADD $8, SP, R4
+				// ADD $8, SP, R20
 				q = obj.Appendp(q, c.newprog)
 				q.As = AADD
 				q.From.Type = obj.TYPE_CONST
 				q.From.Offset = 8
 				q.Reg = REGSP
 				q.To.Type = obj.TYPE_REG
-				q.To.Reg = REG_R4
+				q.To.Reg = REG_R20
 
-				// MOV R4, panic_argp(R1)
+				// MOV R20, panic_argp(RT1)
 				q = obj.Appendp(q, c.newprog)
 				q.As = AMOVD
 				q.From.Type = obj.TYPE_REG
-				q.From.Reg = REG_R4
+				q.From.Reg = REG_R20
 				q.To.Type = obj.TYPE_MEM
-				q.To.Reg = REG_R1
+				q.To.Reg = REGRT1
 				q.To.Offset = 0 // Panic.argp
 
 				// B end
diff --git a/src/cmd/internal/obj/objfile.go b/src/cmd/internal/obj/objfile.go
index 24fb5a19dec..01466ea7360 100644
--- a/src/cmd/internal/obj/objfile.go
+++ b/src/cmd/internal/obj/objfile.go
@@ -452,6 +452,11 @@ func (w *writer) contentHash(s *LSym) goobj.HashType {
 		binary.LittleEndian.PutUint64(tmp[6:14], uint64(r.Add))
 		h.Write(tmp[:])
 		rs := r.Sym
+		if rs == nil {
+			fmt.Printf("symbol: %s\n", s)
+			fmt.Printf("relocation: %#v\n", r)
+			panic("nil symbol target in relocation")
+		}
 		switch rs.PkgIdx {
 		case goobj.PkgIdxHashed64:
 			h.Write([]byte{0})
diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go
index 69f967acfd4..316959f62d7 100644
--- a/src/cmd/internal/obj/ppc64/asm9.go
+++ b/src/cmd/internal/obj/ppc64/asm9.go
@@ -2220,7 +2220,7 @@ func (c *ctxt9) opform(insn uint32) int {
 
 // Encode instructions and create relocation for accessing s+d according to the
 // instruction op with source or destination (as appropriate) register reg.
-func (c *ctxt9) symbolAccess(s *obj.LSym, d int64, reg int16, op uint32) (o1, o2 uint32) {
+func (c *ctxt9) symbolAccess(s *obj.LSym, d int64, reg int16, op uint32, reuse bool) (o1, o2 uint32) {
 	if c.ctxt.Headtype == objabi.Haix {
 		// Every symbol access must be made via a TOC anchor.
 		c.ctxt.Diag("symbolAccess called for %s", s.Name)
@@ -2232,8 +2232,15 @@ func (c *ctxt9) symbolAccess(s *obj.LSym, d int64, reg int16, op uint32) (o1, o2
 	} else {
 		base = REG_R0
 	}
-	o1 = AOP_IRR(OP_ADDIS, REGTMP, base, 0)
-	o2 = AOP_IRR(op, uint32(reg), REGTMP, 0)
+	// If reg can be reused when computing the symbol address,
+	// use it instead of REGTMP.
+	if !reuse {
+		o1 = AOP_IRR(OP_ADDIS, REGTMP, base, 0)
+		o2 = AOP_IRR(op, uint32(reg), REGTMP, 0)
+	} else {
+		o1 = AOP_IRR(OP_ADDIS, uint32(reg), base, 0)
+		o2 = AOP_IRR(op, uint32(reg), uint32(reg), 0)
+	}
 	rel := obj.Addrel(c.cursym)
 	rel.Off = int32(c.pc)
 	rel.Siz = 8
@@ -2877,14 +2884,14 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		switch p.From.Name {
 		case obj.NAME_EXTERN, obj.NAME_STATIC:
 			// Load a 32 bit constant, or relocation depending on if a symbol is attached
-			o1, o2 = c.symbolAccess(p.From.Sym, v, p.To.Reg, OP_ADDI)
+			o1, o2 = c.symbolAccess(p.From.Sym, v, p.To.Reg, OP_ADDI, true)
 		default:
 			if r == 0 {
 				r = c.getimpliedreg(&p.From, p)
 			}
 			// Add a 32 bit offset to a register.
-			o1 = AOP_IRR(OP_ADDIS, REGTMP, uint32(r), uint32(high16adjusted(int32(v))))
-			o2 = AOP_IRR(OP_ADDI, uint32(p.To.Reg), REGTMP, uint32(v))
+			o1 = AOP_IRR(OP_ADDIS, uint32(p.To.Reg), uint32(r), uint32(high16adjusted(int32(v))))
+			o2 = AOP_IRR(OP_ADDI, uint32(p.To.Reg), uint32(p.To.Reg), uint32(v))
 		}
 
 	case 27: /* subc ra,$simm,rd => subfic rd,ra,$simm */
@@ -3043,10 +3050,10 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if r == 0 {
 			r = c.getimpliedreg(&p.From, p)
 		}
-		o1 = AOP_IRR(OP_ADDIS, REGTMP, uint32(r), uint32(high16adjusted(v)))
-		o2 = AOP_IRR(c.opload(p.As), uint32(p.To.Reg), REGTMP, uint32(v))
+		o1 = AOP_IRR(OP_ADDIS, uint32(p.To.Reg), uint32(r), uint32(high16adjusted(v)))
+		o2 = AOP_IRR(c.opload(p.As), uint32(p.To.Reg), uint32(p.To.Reg), uint32(v))
 
-		// Sign extend MOVB operations. This is ignored for other cases (o.size == 8).
+		// Sign extend MOVB if needed
 		o3 = LOP_RRR(OP_EXTSB, uint32(p.To.Reg), uint32(p.To.Reg), 0)
 
 	case 40: /* word */
@@ -3404,7 +3411,8 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if c.opform(inst) == DS_FORM && v&0x3 != 0 {
 			log.Fatalf("invalid offset for DS form load/store %v", p)
 		}
-		o1, o2 = c.symbolAccess(p.To.Sym, v, p.From.Reg, inst)
+		// Can't reuse base for store instructions.
+		o1, o2 = c.symbolAccess(p.To.Sym, v, p.From.Reg, inst, false)
 
 	case 75: // 32 bit offset symbol loads (got/toc/addr)
 		v := p.From.Offset
@@ -3432,10 +3440,11 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 				rel.Type = objabi.R_ADDRPOWER_TOCREL_DS
 			}
 		default:
-			o1, o2 = c.symbolAccess(p.From.Sym, v, p.To.Reg, inst)
+			reuseBaseReg := p.As != AFMOVD && p.As != AFMOVS
+			// Reuse To.Reg as base register if not FP move.
+			o1, o2 = c.symbolAccess(p.From.Sym, v, p.To.Reg, inst, reuseBaseReg)
 		}
 
-		// Sign extend MOVB operations. This is ignored for other cases (o.size == 8).
 		o3 = LOP_RRR(OP_EXTSB, uint32(p.To.Reg), uint32(p.To.Reg), 0)
 
 	case 79:
diff --git a/src/cmd/internal/obj/textflag.go b/src/cmd/internal/obj/textflag.go
index 881e1922031..5ae75027c2f 100644
--- a/src/cmd/internal/obj/textflag.go
+++ b/src/cmd/internal/obj/textflag.go
@@ -49,8 +49,8 @@ const (
 	// Function can call reflect.Type.Method or reflect.Type.MethodByName.
 	REFLECTMETHOD = 1024
 
-	// Function is the top of the call stack. Call stack unwinders should stop
-	// at this function.
+	// Function is the outermost frame of the call stack. Call stack unwinders
+	// should stop at this function.
 	TOPFRAME = 2048
 
 	// Function is an ABI wrapper.
diff --git a/src/cmd/internal/obj/wasm/wasmobj.go b/src/cmd/internal/obj/wasm/wasmobj.go
index ceeae7a257c..4d276db6780 100644
--- a/src/cmd/internal/obj/wasm/wasmobj.go
+++ b/src/cmd/internal/obj/wasm/wasmobj.go
@@ -129,8 +129,6 @@ var (
 	morestackNoCtxt *obj.LSym
 	gcWriteBarrier  *obj.LSym
 	sigpanic        *obj.LSym
-	deferreturn     *obj.LSym
-	jmpdefer        *obj.LSym
 )
 
 const (
@@ -143,10 +141,6 @@ func instinit(ctxt *obj.Link) {
 	morestackNoCtxt = ctxt.Lookup("runtime.morestack_noctxt")
 	gcWriteBarrier = ctxt.LookupABI("runtime.gcWriteBarrier", obj.ABIInternal)
 	sigpanic = ctxt.LookupABI("runtime.sigpanic", obj.ABIInternal)
-	deferreturn = ctxt.LookupABI("runtime.deferreturn", obj.ABIInternal)
-	// jmpdefer is defined in assembly as ABI0. The compiler will
-	// generate a direct ABI0 call from Go, so look for that.
-	jmpdefer = ctxt.LookupABI(`"".jmpdefer`, obj.ABI0)
 }
 
 func preprocess(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
@@ -423,12 +417,6 @@ func preprocess(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 				pcAfterCall-- // sigpanic expects to be called without advancing the pc
 			}
 
-			// jmpdefer manipulates the return address on the stack so deferreturn gets called repeatedly.
-			// Model this in WebAssembly with a loop.
-			if call.To.Sym == deferreturn {
-				p = appendp(p, ALoop)
-			}
-
 			// SP -= 8
 			p = appendp(p, AGet, regAddr(REG_SP))
 			p = appendp(p, AI32Const, constAddr(8))
@@ -479,15 +467,6 @@ func preprocess(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 				break
 			}
 
-			// jmpdefer removes the frame of deferreturn from the Go stack.
-			// However, its WebAssembly function still returns normally,
-			// so we need to return from deferreturn without removing its
-			// stack frame (no RET), because the frame is already gone.
-			if call.To.Sym == jmpdefer {
-				p = appendp(p, AReturn)
-				break
-			}
-
 			// return value of call is on the top of the stack, indicating whether to unwind the WebAssembly stack
 			if call.As == ACALLNORESUME && call.To.Sym != sigpanic { // sigpanic unwinds the stack, but it never resumes
 				// trying to unwind WebAssembly stack but call has no resume point, terminate with error
@@ -500,21 +479,6 @@ func preprocess(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 				unwindExitBranches = append(unwindExitBranches, p)
 			}
 
-			// jump to before the call if jmpdefer has reset the return address to the call's PC
-			if call.To.Sym == deferreturn {
-				// get PC_B from -8(SP)
-				p = appendp(p, AGet, regAddr(REG_SP))
-				p = appendp(p, AI32Const, constAddr(8))
-				p = appendp(p, AI32Sub)
-				p = appendp(p, AI32Load16U, constAddr(0))
-				p = appendp(p, ATee, regAddr(REG_PC_B))
-
-				p = appendp(p, AI32Const, constAddr(call.Pc))
-				p = appendp(p, AI32Eq)
-				p = appendp(p, ABrIf, constAddr(0))
-				p = appendp(p, AEnd) // end of Loop
-			}
-
 		case obj.ARET, ARETUNWIND:
 			ret := *p
 			p.As = obj.ANOP
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 17fa76727e6..331a98dfef9 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -43,7 +43,6 @@ import (
 
 var (
 	plan9privates *obj.LSym
-	deferreturn   *obj.LSym
 )
 
 // Instruction layout.
diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go
index e2732d53e30..183ca2ebe91 100644
--- a/src/cmd/internal/obj/x86/obj6.go
+++ b/src/cmd/internal/obj/x86/obj6.go
@@ -35,7 +35,6 @@ import (
 	"cmd/internal/objabi"
 	"cmd/internal/src"
 	"cmd/internal/sys"
-	"internal/buildcfg"
 	"log"
 	"math"
 	"path"
@@ -647,13 +646,12 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 
 	var regg int16
 	if !p.From.Sym.NoSplit() || p.From.Sym.Wrapper() {
-		if ctxt.Arch.Family == sys.AMD64 && buildcfg.Experiment.RegabiG && cursym.ABI() == obj.ABIInternal {
+		if ctxt.Arch.Family == sys.AMD64 && cursym.ABI() == obj.ABIInternal {
 			regg = REGG // use the g register directly in ABIInternal
 		} else {
 			p = obj.Appendp(p, newprog)
 			regg = REG_CX
 			if ctxt.Arch.Family == sys.AMD64 {
-				// Using this register means that stacksplit works w/ //go:registerparams even when !buildcfg.Experiment.RegabiG
 				regg = REGG // == REG_R14
 			}
 			p = load_g(ctxt, p, newprog, regg) // load g into regg
diff --git a/src/cmd/internal/objabi/funcid.go b/src/cmd/internal/objabi/funcid.go
index 93ebd7be943..68f6a26a76c 100644
--- a/src/cmd/internal/objabi/funcid.go
+++ b/src/cmd/internal/objabi/funcid.go
@@ -34,7 +34,6 @@ const (
 	FuncID_gogo
 	FuncID_gopanic
 	FuncID_handleAsyncEvent
-	FuncID_jmpdefer
 	FuncID_mcall
 	FuncID_morestack
 	FuncID_mstart
@@ -60,7 +59,6 @@ var funcIDs = map[string]FuncID{
 	"gogo":             FuncID_gogo,
 	"gopanic":          FuncID_gopanic,
 	"handleAsyncEvent": FuncID_handleAsyncEvent,
-	"jmpdefer":         FuncID_jmpdefer,
 	"main":             FuncID_runtime_main,
 	"mcall":            FuncID_mcall,
 	"morestack":        FuncID_morestack,
@@ -74,7 +72,6 @@ var funcIDs = map[string]FuncID{
 	// Don't show in call stack but otherwise not special.
 	"deferreturn":       FuncID_wrapper,
 	"runOpenDeferFrame": FuncID_wrapper,
-	"reflectcallSave":   FuncID_wrapper,
 	"deferCallSave":     FuncID_wrapper,
 }
 
diff --git a/src/cmd/internal/objabi/reloctype.go b/src/cmd/internal/objabi/reloctype.go
index ea55fa3b0ad..52827a6deee 100644
--- a/src/cmd/internal/objabi/reloctype.go
+++ b/src/cmd/internal/objabi/reloctype.go
@@ -101,6 +101,9 @@ const (
 	// *rtype, and may be set to zero by the linker if it determines the method
 	// text is unreachable by the linked program.
 	R_METHODOFF
+	// R_KEEP tells the linker to keep the referred-to symbol in the final binary
+	// if the symbol containing the R_KEEP relocation is in the final binary.
+	R_KEEP
 	R_POWER_TOC
 	R_GOTPCREL
 	// R_JMPMIPS (only used on mips64) resolves to non-PC-relative target address
diff --git a/src/cmd/internal/objabi/reloctype_string.go b/src/cmd/internal/objabi/reloctype_string.go
index 8882d19f883..4638ef14d91 100644
--- a/src/cmd/internal/objabi/reloctype_string.go
+++ b/src/cmd/internal/objabi/reloctype_string.go
@@ -34,44 +34,45 @@ func _() {
 	_ = x[R_USEIFACE-24]
 	_ = x[R_USEIFACEMETHOD-25]
 	_ = x[R_METHODOFF-26]
-	_ = x[R_POWER_TOC-27]
-	_ = x[R_GOTPCREL-28]
-	_ = x[R_JMPMIPS-29]
-	_ = x[R_DWARFSECREF-30]
-	_ = x[R_DWARFFILEREF-31]
-	_ = x[R_ARM64_TLS_LE-32]
-	_ = x[R_ARM64_TLS_IE-33]
-	_ = x[R_ARM64_GOTPCREL-34]
-	_ = x[R_ARM64_GOT-35]
-	_ = x[R_ARM64_PCREL-36]
-	_ = x[R_ARM64_LDST8-37]
-	_ = x[R_ARM64_LDST16-38]
-	_ = x[R_ARM64_LDST32-39]
-	_ = x[R_ARM64_LDST64-40]
-	_ = x[R_ARM64_LDST128-41]
-	_ = x[R_POWER_TLS_LE-42]
-	_ = x[R_POWER_TLS_IE-43]
-	_ = x[R_POWER_TLS-44]
-	_ = x[R_ADDRPOWER_DS-45]
-	_ = x[R_ADDRPOWER_GOT-46]
-	_ = x[R_ADDRPOWER_PCREL-47]
-	_ = x[R_ADDRPOWER_TOCREL-48]
-	_ = x[R_ADDRPOWER_TOCREL_DS-49]
-	_ = x[R_RISCV_PCREL_ITYPE-50]
-	_ = x[R_RISCV_PCREL_STYPE-51]
-	_ = x[R_RISCV_TLS_IE_ITYPE-52]
-	_ = x[R_RISCV_TLS_IE_STYPE-53]
-	_ = x[R_PCRELDBL-54]
-	_ = x[R_ADDRMIPSU-55]
-	_ = x[R_ADDRMIPSTLS-56]
-	_ = x[R_ADDRCUOFF-57]
-	_ = x[R_WASMIMPORT-58]
-	_ = x[R_XCOFFREF-59]
+	_ = x[R_KEEP-27]
+	_ = x[R_POWER_TOC-28]
+	_ = x[R_GOTPCREL-29]
+	_ = x[R_JMPMIPS-30]
+	_ = x[R_DWARFSECREF-31]
+	_ = x[R_DWARFFILEREF-32]
+	_ = x[R_ARM64_TLS_LE-33]
+	_ = x[R_ARM64_TLS_IE-34]
+	_ = x[R_ARM64_GOTPCREL-35]
+	_ = x[R_ARM64_GOT-36]
+	_ = x[R_ARM64_PCREL-37]
+	_ = x[R_ARM64_LDST8-38]
+	_ = x[R_ARM64_LDST16-39]
+	_ = x[R_ARM64_LDST32-40]
+	_ = x[R_ARM64_LDST64-41]
+	_ = x[R_ARM64_LDST128-42]
+	_ = x[R_POWER_TLS_LE-43]
+	_ = x[R_POWER_TLS_IE-44]
+	_ = x[R_POWER_TLS-45]
+	_ = x[R_ADDRPOWER_DS-46]
+	_ = x[R_ADDRPOWER_GOT-47]
+	_ = x[R_ADDRPOWER_PCREL-48]
+	_ = x[R_ADDRPOWER_TOCREL-49]
+	_ = x[R_ADDRPOWER_TOCREL_DS-50]
+	_ = x[R_RISCV_PCREL_ITYPE-51]
+	_ = x[R_RISCV_PCREL_STYPE-52]
+	_ = x[R_RISCV_TLS_IE_ITYPE-53]
+	_ = x[R_RISCV_TLS_IE_STYPE-54]
+	_ = x[R_PCRELDBL-55]
+	_ = x[R_ADDRMIPSU-56]
+	_ = x[R_ADDRMIPSTLS-57]
+	_ = x[R_ADDRCUOFF-58]
+	_ = x[R_WASMIMPORT-59]
+	_ = x[R_XCOFFREF-60]
 }
 
-const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CALLRISCVR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_METHODOFFR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IE_ITYPER_RISCV_TLS_IE_STYPER_PCRELDBLR_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREF"
+const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CALLRISCVR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_METHODOFFR_KEEPR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IE_ITYPER_RISCV_TLS_IE_STYPER_PCRELDBLR_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREF"
 
-var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 120, 127, 134, 142, 150, 158, 164, 170, 176, 186, 195, 205, 221, 232, 243, 253, 262, 275, 289, 303, 317, 333, 344, 357, 370, 384, 398, 412, 427, 441, 455, 466, 480, 495, 512, 530, 551, 570, 589, 609, 629, 639, 650, 663, 674, 686, 696}
+var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 120, 127, 134, 142, 150, 158, 164, 170, 176, 186, 195, 205, 221, 232, 238, 249, 259, 268, 281, 295, 309, 323, 339, 350, 363, 376, 390, 404, 418, 433, 447, 461, 472, 486, 501, 518, 536, 557, 576, 595, 615, 635, 645, 656, 669, 680, 692, 702}
 
 func (i RelocType) String() string {
 	i -= 1
diff --git a/src/cmd/internal/objfile/goobj.go b/src/cmd/internal/objfile/goobj.go
index f19bec5dcb2..dd21d223511 100644
--- a/src/cmd/internal/objfile/goobj.go
+++ b/src/cmd/internal/objfile/goobj.go
@@ -168,7 +168,7 @@ func (f *goobjFile) symbols() ([]Sym, error) {
 			code = 'T'
 		case objabi.SRODATA:
 			code = 'R'
-		case objabi.SDATA:
+		case objabi.SNOPTRDATA, objabi.SDATA:
 			code = 'D'
 		case objabi.SBSS, objabi.SNOPTRBSS, objabi.STLSBSS:
 			code = 'B'
diff --git a/src/cmd/go/internal/str/path.go b/src/cmd/internal/str/path.go
similarity index 100%
rename from src/cmd/go/internal/str/path.go
rename to src/cmd/internal/str/path.go
diff --git a/src/cmd/go/internal/str/str.go b/src/cmd/internal/str/str.go
similarity index 100%
rename from src/cmd/go/internal/str/str.go
rename to src/cmd/internal/str/str.go
diff --git a/src/cmd/go/internal/str/str_test.go b/src/cmd/internal/str/str_test.go
similarity index 100%
rename from src/cmd/go/internal/str/str_test.go
rename to src/cmd/internal/str/str_test.go
diff --git a/src/cmd/internal/sys/arch.go b/src/cmd/internal/sys/arch.go
index e8687363def..a3e39768b6f 100644
--- a/src/cmd/internal/sys/arch.go
+++ b/src/cmd/internal/sys/arch.go
@@ -40,6 +40,12 @@ type Arch struct {
 
 	// MinLC is the minimum length of an instruction code.
 	MinLC int
+
+	// Alignment is maximum alignment required by the architecture
+	// for any (compiler-generated) load or store instruction.
+	// Loads or stores smaller than Alignment must be naturally aligned.
+	// Loads or stores larger than Alignment need only be Alignment-aligned.
+	Alignment int8
 }
 
 // InFamily reports whether a is a member of any of the specified
@@ -60,6 +66,7 @@ var Arch386 = &Arch{
 	PtrSize:   4,
 	RegSize:   4,
 	MinLC:     1,
+	Alignment: 1,
 }
 
 var ArchAMD64 = &Arch{
@@ -69,6 +76,7 @@ var ArchAMD64 = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     1,
+	Alignment: 1,
 }
 
 var ArchARM = &Arch{
@@ -78,6 +86,7 @@ var ArchARM = &Arch{
 	PtrSize:   4,
 	RegSize:   4,
 	MinLC:     4,
+	Alignment: 4, // TODO: just for arm5?
 }
 
 var ArchARM64 = &Arch{
@@ -87,6 +96,7 @@ var ArchARM64 = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 1,
 }
 
 var ArchMIPS = &Arch{
@@ -96,6 +106,7 @@ var ArchMIPS = &Arch{
 	PtrSize:   4,
 	RegSize:   4,
 	MinLC:     4,
+	Alignment: 4,
 }
 
 var ArchMIPSLE = &Arch{
@@ -105,6 +116,7 @@ var ArchMIPSLE = &Arch{
 	PtrSize:   4,
 	RegSize:   4,
 	MinLC:     4,
+	Alignment: 4,
 }
 
 var ArchMIPS64 = &Arch{
@@ -114,6 +126,7 @@ var ArchMIPS64 = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 8,
 }
 
 var ArchMIPS64LE = &Arch{
@@ -123,6 +136,7 @@ var ArchMIPS64LE = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 8,
 }
 
 var ArchPPC64 = &Arch{
@@ -132,6 +146,7 @@ var ArchPPC64 = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 1,
 }
 
 var ArchPPC64LE = &Arch{
@@ -141,6 +156,7 @@ var ArchPPC64LE = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 1,
 }
 
 var ArchRISCV64 = &Arch{
@@ -150,6 +166,7 @@ var ArchRISCV64 = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     4,
+	Alignment: 8, // riscv unaligned loads work, but are really slow (trap + simulated by OS)
 }
 
 var ArchS390X = &Arch{
@@ -159,6 +176,7 @@ var ArchS390X = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     2,
+	Alignment: 1,
 }
 
 var ArchWasm = &Arch{
@@ -168,6 +186,7 @@ var ArchWasm = &Arch{
 	PtrSize:   8,
 	RegSize:   8,
 	MinLC:     1,
+	Alignment: 1,
 }
 
 var Archs = [...]*Arch{
diff --git a/src/cmd/internal/sys/supported.go b/src/cmd/internal/sys/supported.go
index fa477b837ff..0d2bad96127 100644
--- a/src/cmd/internal/sys/supported.go
+++ b/src/cmd/internal/sys/supported.go
@@ -74,7 +74,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 			"android/amd64", "android/arm", "android/arm64", "android/386",
 			"freebsd/amd64",
 			"darwin/amd64", "darwin/arm64",
-			"windows/amd64", "windows/386":
+			"windows/amd64", "windows/386", "windows/arm64":
 			return true
 		}
 		return false
diff --git a/src/cmd/link/cgo_test.go b/src/cmd/link/cgo_test.go
new file mode 100644
index 00000000000..26ab8024541
--- /dev/null
+++ b/src/cmd/link/cgo_test.go
@@ -0,0 +1,141 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+// Issues 43830, 46295
+func TestCGOLTO(t *testing.T) {
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveGoBuild(t)
+
+	t.Parallel()
+
+	for _, cc := range []string{"gcc", "clang"} {
+		for test := 0; test < 2; test++ {
+			t.Run(fmt.Sprintf("%s-%d", cc, test), func(t *testing.T) {
+				testCGOLTO(t, cc, test)
+			})
+		}
+	}
+}
+
+const test1_main = `
+package main
+
+/*
+extern int myadd(int, int);
+int c_add(int a, int b) {
+	return myadd(a, b);
+}
+*/
+import "C"
+
+func main() {
+	println(C.c_add(1, 2))
+}
+`
+
+const test1_add = `
+package main
+
+import "C"
+
+/* test */
+
+//export myadd
+func myadd(a C.int, b C.int) C.int {
+	return a + b
+}
+`
+
+const test2_main = `
+package main
+
+import "fmt"
+
+/*
+#include 
+
+void hello(void) {
+  printf("hello\n");
+}
+*/
+import "C"
+
+func main() {
+	hello := C.hello
+	fmt.Printf("%v\n", hello)
+}
+`
+
+func testCGOLTO(t *testing.T, cc string, test int) {
+	t.Parallel()
+
+	if _, err := exec.LookPath(cc); err != nil {
+		t.Skipf("no %s compiler", cc)
+	}
+
+	dir := t.TempDir()
+
+	writeTempFile := func(name, contents string) {
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(contents), 0644); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	writeTempFile("go.mod", "module cgolto\n")
+
+	switch test {
+	case 0:
+		writeTempFile("main.go", test1_main)
+		writeTempFile("add.go", test1_add)
+	case 1:
+		writeTempFile("main.go", test2_main)
+	default:
+		t.Fatalf("bad case %d", test)
+	}
+
+	cmd := exec.Command(testenv.GoToolPath(t), "build")
+	cmd.Dir = dir
+	cmd.Env = append(os.Environ(),
+		"CC="+cc,
+		"CGO_CFLAGS=-flto",
+	)
+
+	t.Log("go build")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%s", out)
+
+	if err != nil {
+		t.Logf("go build failed: %v", err)
+
+		// Error messages we've seen indicating that LTO is not supported.
+		// These errors come from GCC or clang, not Go.
+		var noLTO = []string{
+			`unrecognized command line option "-flto"`,
+			"unable to pass LLVM bit-code files to linker",
+			"file not recognized: File format not recognized",
+			"LTO support has not been enabled",
+			"linker command failed with exit code",
+			"gcc: can't load library",
+		}
+		for _, msg := range noLTO {
+			if bytes.Contains(out, []byte(msg)) {
+				t.Skipf("C compiler %v does not support LTO", cc)
+			}
+		}
+
+		t.Error("failed")
+	}
+}
diff --git a/src/cmd/link/dwarf_test.go b/src/cmd/link/dwarf_test.go
index 0419613cbe2..3ca59bd47f0 100644
--- a/src/cmd/link/dwarf_test.go
+++ b/src/cmd/link/dwarf_test.go
@@ -19,6 +19,36 @@ import (
 	"testing"
 )
 
+// TestMain allows this test binary to run as a -toolexec wrapper for the 'go'
+// command. If LINK_TEST_TOOLEXEC is set, TestMain runs the binary as if it were
+// cmd/link, and otherwise runs the requested tool as a subprocess.
+//
+// This allows the test to verify the behavior of the current contents of the
+// cmd/link package even if the installed cmd/link binary is stale.
+func TestMain(m *testing.M) {
+	if os.Getenv("LINK_TEST_TOOLEXEC") == "" {
+		// Not running as a -toolexec wrapper. Just run the tests.
+		os.Exit(m.Run())
+	}
+
+	if strings.TrimSuffix(filepath.Base(os.Args[1]), ".exe") == "link" {
+		// Running as a -toolexec linker, and the tool is cmd/link.
+		// Substitute this test binary for the linker.
+		os.Args = os.Args[1:]
+		main()
+		os.Exit(0)
+	}
+
+	cmd := exec.Command(os.Args[1], os.Args[2:]...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		os.Exit(1)
+	}
+	os.Exit(0)
+}
+
 func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string) {
 	testenv.MustHaveCGO(t)
 	testenv.MustHaveGoBuild(t)
@@ -29,17 +59,6 @@ func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string)
 
 	t.Parallel()
 
-	out, err := exec.Command(testenv.GoToolPath(t), "list", "-f", "{{.Stale}}", "cmd/link").CombinedOutput()
-	if err != nil {
-		t.Fatalf("go list: %v\n%s", err, out)
-	}
-	if string(out) != "false\n" {
-		if strings.HasPrefix(testenv.Builder(), "darwin-") {
-			t.Skipf("cmd/link is spuriously stale on Darwin builders - see #33598")
-		}
-		t.Fatalf("cmd/link is stale - run go install cmd/link")
-	}
-
 	for _, prog := range []string{"testprog", "testprogcgo"} {
 		prog := prog
 		expectDWARF := expectDWARF
@@ -48,11 +67,11 @@ func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string)
 			if extld == "" {
 				extld = "gcc"
 			}
+			var err error
 			expectDWARF, err = cmddwarf.IsDWARFEnabledOnAIXLd(extld)
 			if err != nil {
 				t.Fatal(err)
 			}
-
 		}
 
 		t.Run(prog, func(t *testing.T) {
@@ -62,15 +81,14 @@ func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string)
 
 			exe := filepath.Join(tmpDir, prog+".exe")
 			dir := "../../runtime/testdata/" + prog
-			cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", exe)
+			cmd := exec.Command(testenv.GoToolPath(t), "build", "-toolexec", os.Args[0], "-o", exe)
 			if buildmode != "" {
 				cmd.Args = append(cmd.Args, "-buildmode", buildmode)
 			}
 			cmd.Args = append(cmd.Args, dir)
-			if env != nil {
-				cmd.Env = append(os.Environ(), env...)
-				cmd.Env = append(cmd.Env, "CGO_CFLAGS=") // ensure CGO_CFLAGS does not contain any flags. Issue #35459
-			}
+			cmd.Env = append(os.Environ(), env...)
+			cmd.Env = append(cmd.Env, "CGO_CFLAGS=") // ensure CGO_CFLAGS does not contain any flags. Issue #35459
+			cmd.Env = append(cmd.Env, "LINK_TEST_TOOLEXEC=1")
 			out, err := cmd.CombinedOutput()
 			if err != nil {
 				t.Fatalf("go build -o %v %v: %v\n%s", exe, dir, err, out)
diff --git a/src/cmd/link/internal/ld/ar.go b/src/cmd/link/internal/ld/ar.go
index 22f53a4df2e..23915f90329 100644
--- a/src/cmd/link/internal/ld/ar.go
+++ b/src/cmd/link/internal/ld/ar.go
@@ -124,6 +124,10 @@ func hostArchive(ctxt *Link, name string) {
 
 			libgcc := sym.Library{Pkg: "libgcc"}
 			h := ldobj(ctxt, f, &libgcc, l, pname, name)
+			if h.ld == nil {
+				Errorf(nil, "%s unrecognized object file at offset %d", name, off)
+				continue
+			}
 			f.MustSeek(h.off, 0)
 			h.ld(ctxt, f, h.pkg, h.length, h.pn)
 		}
diff --git a/src/cmd/link/internal/ld/asmb.go b/src/cmd/link/internal/ld/asmb.go
index 37546695556..d6ecb2895ba 100644
--- a/src/cmd/link/internal/ld/asmb.go
+++ b/src/cmd/link/internal/ld/asmb.go
@@ -167,7 +167,10 @@ func sizeExtRelocs(ctxt *Link, relsize uint32) {
 		}
 	}
 	filesz := ctxt.Out.Offset() + sz
-	ctxt.Out.Mmap(uint64(filesz))
+	err := ctxt.Out.Mmap(uint64(filesz))
+	if err != nil {
+		Exitf("mapping output file failed: %v", err)
+	}
 }
 
 // relocSectFn wraps the function writing relocations of a section
diff --git a/src/cmd/link/internal/ld/config.go b/src/cmd/link/internal/ld/config.go
index ae0d7520ebc..20f1d0b8c12 100644
--- a/src/cmd/link/internal/ld/config.go
+++ b/src/cmd/link/internal/ld/config.go
@@ -241,6 +241,10 @@ func mustLinkExternal(ctxt *Link) (res bool, reason string) {
 		return true, "dynamically linking with a shared library"
 	}
 
+	if unknownObjFormat {
+		return true, "some input objects have an unrecognized file format"
+	}
+
 	return false, ""
 }
 
@@ -248,7 +252,7 @@ func mustLinkExternal(ctxt *Link) (res bool, reason string) {
 //
 // It is called after flags are processed and inputs are processed,
 // so the ctxt.LinkMode variable has an initial value from the -linkmode
-// flag and the iscgo externalobj variables are set.
+// flag and the iscgo, externalobj, and unknownObjFormat variables are set.
 func determineLinkMode(ctxt *Link) {
 	extNeeded, extReason := mustLinkExternal(ctxt)
 	via := ""
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 6659e95cc1f..70fbb9dc4e2 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -340,6 +340,7 @@ func (st *relocSymState) relocsym(s loader.Sym, P []byte) {
 			if weak && !ldr.AttrReachable(rs) {
 				// Redirect it to runtime.unreachableMethod, which will throw if called.
 				rs = syms.unreachableMethod
+				rs = ldr.ResolveABIAlias(rs)
 			}
 			if target.IsExternal() {
 				nExtReloc++
@@ -623,6 +624,7 @@ func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loa
 		rs := ldr.ResolveABIAlias(r.Sym())
 		if r.Weak() && !ldr.AttrReachable(rs) {
 			rs = ctxt.ArchSyms.unreachableMethod
+			rs = ldr.ResolveABIAlias(rs)
 		}
 		rs, off := FoldSubSymbolOffset(ldr, rs)
 		rr.Xadd = r.Add() + off
@@ -1548,7 +1550,7 @@ func (ctxt *Link) dodata(symGroupType []sym.SymKind) {
 
 	if ctxt.HeadType == objabi.Haix && ctxt.LinkMode == LinkExternal {
 		// These symbols must have the same alignment as their section.
-		// Otherwize, ld might change the layout of Go sections.
+		// Otherwise, ld might change the layout of Go sections.
 		ldr.SetSymAlign(ldr.Lookup("runtime.data", 0), state.dataMaxAlign[sym.SDATA])
 		ldr.SetSymAlign(ldr.Lookup("runtime.bss", 0), state.dataMaxAlign[sym.SBSS])
 	}
diff --git a/src/cmd/link/internal/ld/deadcode.go b/src/cmd/link/internal/ld/deadcode.go
index 1ed5598c99d..dd5dafc21b2 100644
--- a/src/cmd/link/internal/ld/deadcode.go
+++ b/src/cmd/link/internal/ld/deadcode.go
@@ -65,26 +65,26 @@ func (d *deadcodePass) init() {
 			}
 		}
 		names = append(names, *flagEntrySymbol)
-		// runtime.unreachableMethod is a function that will throw if called.
-		// We redirect unreachable methods to it.
-		names = append(names, "runtime.unreachableMethod")
-		if !d.ctxt.linkShared && d.ctxt.BuildMode != BuildModePlugin {
-			// runtime.buildVersion and runtime.modinfo are referenced in .go.buildinfo section
-			// (see function buildinfo in data.go). They should normally be reachable from the
-			// runtime. Just make it explicit, in case.
-			names = append(names, "runtime.buildVersion", "runtime.modinfo")
-		}
-		if d.ctxt.BuildMode == BuildModePlugin {
-			names = append(names, objabi.PathToPrefix(*flagPluginPath)+"..inittask", objabi.PathToPrefix(*flagPluginPath)+".main", "go.plugin.tabs")
+	}
+	// runtime.unreachableMethod is a function that will throw if called.
+	// We redirect unreachable methods to it.
+	names = append(names, "runtime.unreachableMethod")
+	if !d.ctxt.linkShared && d.ctxt.BuildMode != BuildModePlugin {
+		// runtime.buildVersion and runtime.modinfo are referenced in .go.buildinfo section
+		// (see function buildinfo in data.go). They should normally be reachable from the
+		// runtime. Just make it explicit, in case.
+		names = append(names, "runtime.buildVersion", "runtime.modinfo")
+	}
+	if d.ctxt.BuildMode == BuildModePlugin {
+		names = append(names, objabi.PathToPrefix(*flagPluginPath)+"..inittask", objabi.PathToPrefix(*flagPluginPath)+".main", "go.plugin.tabs")
 
-			// We don't keep the go.plugin.exports symbol,
-			// but we do keep the symbols it refers to.
-			exportsIdx := d.ldr.Lookup("go.plugin.exports", 0)
-			if exportsIdx != 0 {
-				relocs := d.ldr.Relocs(exportsIdx)
-				for i := 0; i < relocs.Count(); i++ {
-					d.mark(relocs.At(i).Sym(), 0)
-				}
+		// We don't keep the go.plugin.exports symbol,
+		// but we do keep the symbols it refers to.
+		exportsIdx := d.ldr.Lookup("go.plugin.exports", 0)
+		if exportsIdx != 0 {
+			relocs := d.ldr.Relocs(exportsIdx)
+			for i := 0; i < relocs.Count(); i++ {
+				d.mark(relocs.At(i).Sym(), 0)
 			}
 		}
 	}
@@ -408,6 +408,9 @@ func (d *deadcodePass) decodeMethodSig(ldr *loader.Loader, arch *sys.Arch, symId
 // Decode the method of interface type symbol symIdx at offset off.
 func (d *deadcodePass) decodeIfaceMethod(ldr *loader.Loader, arch *sys.Arch, symIdx loader.Sym, off int64) methodsig {
 	p := ldr.Data(symIdx)
+	if p == nil {
+		panic(fmt.Sprintf("missing symbol %q", ldr.SymName(symIdx)))
+	}
 	if decodetypeKind(arch, p)&kindMask != kindInterface {
 		panic(fmt.Sprintf("symbol %q is not an interface", ldr.SymName(symIdx)))
 	}
diff --git a/src/cmd/link/internal/ld/decodesym.go b/src/cmd/link/internal/ld/decodesym.go
index fc179fc6e44..629bdcf4cac 100644
--- a/src/cmd/link/internal/ld/decodesym.go
+++ b/src/cmd/link/internal/ld/decodesym.go
@@ -10,17 +10,18 @@ import (
 	"cmd/link/internal/loader"
 	"cmd/link/internal/sym"
 	"debug/elf"
+	"encoding/binary"
 	"log"
 )
 
 // Decoding the type.* symbols.	 This has to be in sync with
 // ../../runtime/type.go, or more specifically, with what
-// cmd/compile/internal/gc/reflect.go stuffs in these.
+// cmd/compile/internal/reflectdata/reflect.go stuffs in these.
 
 // tflag is documented in reflect/type.go.
 //
 // tflag values must be kept in sync with copies in:
-//	cmd/compile/internal/gc/reflect.go
+//	cmd/compile/internal/reflectdata/reflect.go
 //	cmd/link/internal/ld/decodesym.go
 //	reflect/type.go
 //	runtime/type.go
@@ -126,8 +127,8 @@ func decodetypeName(ldr *loader.Loader, symIdx loader.Sym, relocs *loader.Relocs
 	}
 
 	data := ldr.Data(r)
-	namelen := int(uint16(data[1])<<8 | uint16(data[2]))
-	return string(data[3 : 3+namelen])
+	nameLen, nameLenLen := binary.Uvarint(data[1:])
+	return string(data[1+nameLenLen : 1+nameLenLen+int(nameLen)])
 }
 
 func decodetypeFuncInType(ldr *loader.Loader, arch *sys.Arch, symIdx loader.Sym, relocs *loader.Relocs, i int) loader.Sym {
diff --git a/src/cmd/link/internal/ld/dwarf_test.go b/src/cmd/link/internal/ld/dwarf_test.go
index 5cc4800e2a3..543dd5caac7 100644
--- a/src/cmd/link/internal/ld/dwarf_test.go
+++ b/src/cmd/link/internal/ld/dwarf_test.go
@@ -101,8 +101,11 @@ func gobuild(t *testing.T, dir string, testfile string, gcflags string) *builtFi
 	}
 
 	cmd := exec.Command(testenv.GoToolPath(t), "build", gcflags, "-o", dst, src)
-	if b, err := cmd.CombinedOutput(); err != nil {
-		t.Logf("build: %s\n", b)
+	b, err := cmd.CombinedOutput()
+	if len(b) != 0 {
+		t.Logf("## build output:\n%s", b)
+	}
+	if err != nil {
 		t.Fatalf("build error: %v", err)
 	}
 
@@ -1660,16 +1663,16 @@ func TestOutputParamAbbrevAndAttr(t *testing.T) {
 package main
 
 //go:noinline
-func ABC(p1, p2, p3 int, f1, f2, f3 float32, b1 [1024]int) (r1 int, r2 int, r3 [1024]int, r4 byte) {
-	b1[0] = 6
-	r1, r2, r3, r4 = p3, p2, b1, 'a'
+func ABC(c1, c2, c3 int, d1, d2, d3, d4 string, f1, f2, f3 float32, g1 [1024]int) (r1 int, r2 int, r3 [1024]int, r4 byte, r5 string, r6 float32) {
+	g1[0] = 6
+	r1, r2, r3, r4, r5, r6 = c3, c2+c1, g1, 'a', d1+d2+d3+d4, f1+f2+f3
 	return
 }
 
 func main() {
 	a := [1024]int{}
-	v1, v2, v3, v4 := ABC(1, 2, 3, 1.0, 2.0, 1.0, a)
-	println(v1, v2, v3[0], v4)
+	v1, v2, v3, v4, v5, v6 := ABC(1, 2, 3, "a", "b", "c", "d", 1.0, 2.0, 1.0, a)
+	println(v1, v2, v3[0], v4, v5, v6)
 }
 `
 	dir := t.TempDir()
@@ -1708,18 +1711,20 @@ func main() {
 	// OK to have it missing for input parameters, but for the moment
 	// we verify that the attr is present but set to false.
 
-	// Values in this map:
+	// Values in this map are of the form :
+	// where order is the order within the child DIE list of the param,
+	// and  is an integer:
 	//
-	//   0: 
 	//  -1: varparm attr not found
 	//   1: varparm found with value false
 	//   2: varparm found with value true
 	//
-	foundParams := make(map[string]int)
+	foundParams := make(map[string]string)
 
 	// Walk ABCs's children looking for params.
 	abcIdx := ex.idxFromOffset(abcdie.Offset)
 	childDies := ex.Children(abcIdx)
+	idx := 0
 	for _, child := range childDies {
 		if child.Tag == dwarf.TagFormalParameter {
 			st := -1
@@ -1731,7 +1736,8 @@ func main() {
 				}
 			}
 			if name, ok := child.Val(dwarf.AttrName).(string); ok {
-				foundParams[name] = st
+				foundParams[name] = fmt.Sprintf("%d:%d", idx, st)
+				idx++
 			}
 		}
 	}
@@ -1739,13 +1745,14 @@ func main() {
 	// Digest the result.
 	found := make([]string, 0, len(foundParams))
 	for k, v := range foundParams {
-		found = append(found, fmt.Sprintf("%s:%d", k, v))
+		found = append(found, fmt.Sprintf("%s:%s", k, v))
 	}
 	sort.Strings(found)
 
-	// Make sure we see all of the expected params, that they have
-	// the varparam attr, and the varparm is set for the returns.
-	expected := "[b1:1 f1:1 f2:1 f3:1 p1:1 p2:1 p3:1 r1:2 r2:2 r3:2 r4:2]"
+	// Make sure we see all of the expected params in the proper
+	// order, that they have the varparam attr, and the varparm is set
+	// for the returns.
+	expected := "[c1:0:1 c2:1:1 c3:2:1 d1:3:1 d2:4:1 d3:5:1 d4:6:1 f1:7:1 f2:8:1 f3:9:1 g1:10:1 r1:11:2 r2:12:2 r3:13:2 r4:14:2 r5:15:2 r6:16:2]"
 	if fmt.Sprintf("%+v", found) != expected {
 		t.Errorf("param check failed, wanted %s got %s\n",
 			expected, found)
diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index 87d88dd957d..81011638bc5 100644
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -950,6 +950,11 @@ func elfdynhash(ctxt *Link) {
 	}
 
 	s = ldr.CreateSymForUpdate(".dynamic", 0)
+	if ctxt.BuildMode == BuildModePIE {
+		// https://github.com/bminor/glibc/blob/895ef79e04a953cac1493863bcae29ad85657ee1/elf/elf.h#L986
+		const DTFLAGS_1_PIE = 0x08000000
+		Elfwritedynent(ctxt.Arch, s, elf.DT_FLAGS_1, uint64(DTFLAGS_1_PIE))
+	}
 	elfverneed = nfile
 	if elfverneed != 0 {
 		elfWriteDynEntSym(ctxt, s, elf.DT_VERNEED, gnuVersionR.Sym())
@@ -1171,7 +1176,7 @@ func elfrelocsect(ctxt *Link, out *OutBuf, sect *sym.Section, syms []loader.Sym)
 		}
 	}
 
-	eaddr := int32(sect.Vaddr + sect.Length)
+	eaddr := sect.Vaddr + sect.Length
 	for _, s := range syms {
 		if !ldr.AttrReachable(s) {
 			continue
diff --git a/src/cmd/link/internal/ld/ld_test.go b/src/cmd/link/internal/ld/ld_test.go
index ca764632c3d..3702a4d08f5 100644
--- a/src/cmd/link/internal/ld/ld_test.go
+++ b/src/cmd/link/internal/ld/ld_test.go
@@ -174,6 +174,8 @@ func TestWindowsBuildmodeCSharedASLR(t *testing.T) {
 		t.Skip("skipping windows amd64/386 only test")
 	}
 
+	testenv.MustHaveCGO(t)
+
 	t.Run("aslr", func(t *testing.T) {
 		testWindowsBuildmodeCSharedASLR(t, true)
 	})
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index eb85c88fbfb..d7e408669e7 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -343,10 +343,16 @@ var (
 const pkgdef = "__.PKGDEF"
 
 var (
-	// Set if we see an object compiled by the host compiler that is not
-	// from a package that is known to support internal linking mode.
+	// externalobj is set to true if we see an object compiled by
+	// the host compiler that is not from a package that is known
+	// to support internal linking mode.
 	externalobj = false
-	theline     string
+
+	// unknownObjFormat is set to true if we see an object whose
+	// format we don't recognize.
+	unknownObjFormat = false
+
+	theline string
 )
 
 func Lflag(ctxt *Link, arg string) {
@@ -1066,6 +1072,10 @@ func hostobjs(ctxt *Link) {
 		}
 
 		f.MustSeek(h.off, 0)
+		if h.ld == nil {
+			Errorf(nil, "%s: unrecognized object file format", h.pn)
+			continue
+		}
 		h.ld(ctxt, f, h.pkg, h.length, h.pn)
 		f.Close()
 	}
@@ -1856,6 +1866,14 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 		return ldhostobj(ldxcoff, ctxt.HeadType, f, pkg, length, pn, file)
 	}
 
+	if c1 != 'g' || c2 != 'o' || c3 != ' ' || c4 != 'o' {
+		// An unrecognized object is just passed to the external linker.
+		// If we try to read symbols from this object, we will
+		// report an error at that time.
+		unknownObjFormat = true
+		return ldhostobj(nil, ctxt.HeadType, f, pkg, length, pn, file)
+	}
+
 	/* check the header */
 	line, err := f.ReadString('\n')
 	if err != nil {
@@ -1875,7 +1893,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 			return nil
 		}
 
-		Errorf(nil, "%s: not an object file: @%d %02x%02x%02x%02x", pn, start, c1, c2, c3, c4)
+		Errorf(nil, "%s: not an object file: @%d %q", pn, start, line)
 		return nil
 	}
 
diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index 642113cf070..45a3971c33f 100644
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -1194,7 +1194,7 @@ func machorelocsect(ctxt *Link, out *OutBuf, sect *sym.Section, syms []loader.Sy
 		}
 	}
 
-	eaddr := int32(sect.Vaddr + sect.Length)
+	eaddr := sect.Vaddr + sect.Length
 	for _, s := range syms {
 		if !ldr.AttrReachable(s) {
 			continue
diff --git a/src/cmd/link/internal/ld/main.go b/src/cmd/link/internal/ld/main.go
index adb39d06076..cba0e3d81fe 100644
--- a/src/cmd/link/internal/ld/main.go
+++ b/src/cmd/link/internal/ld/main.go
@@ -334,7 +334,7 @@ func Main(arch *sys.Arch, theArch Arch) {
 		// Don't mmap if we're building for Wasm. Wasm file
 		// layout is very different so filesize is meaningless.
 		if err := ctxt.Out.Mmap(filesize); err != nil {
-			panic(err)
+			Exitf("mapping output file failed: %v", err)
 		}
 	}
 	// asmb will redirect symbols to the output file mmap, and relocations
diff --git a/src/cmd/link/internal/ld/outbuf.go b/src/cmd/link/internal/ld/outbuf.go
index 530836ef7cf..9d5e8854fea 100644
--- a/src/cmd/link/internal/ld/outbuf.go
+++ b/src/cmd/link/internal/ld/outbuf.go
@@ -160,7 +160,7 @@ func (out *OutBuf) copyHeap() bool {
 	total := uint64(bufLen + heapLen)
 	if heapLen != 0 {
 		if err := out.Mmap(total); err != nil { // Mmap will copy out.heap over to out.buf
-			panic(err)
+			Exitf("mapping output file failed: %v", err)
 		}
 	}
 	return true
diff --git a/src/cmd/link/internal/ld/pcln.go b/src/cmd/link/internal/ld/pcln.go
index 05fd3023694..70e3e1284b9 100644
--- a/src/cmd/link/internal/ld/pcln.go
+++ b/src/cmd/link/internal/ld/pcln.go
@@ -129,11 +129,10 @@ func computeDeferReturn(ctxt *Link, deferReturnSym, s loader.Sym) uint32 {
 	for ri := 0; ri < relocs.Count(); ri++ {
 		r := relocs.At(ri)
 		if target.IsWasm() && r.Type() == objabi.R_ADDR {
-			// Wasm does not have a live variable set at the deferreturn
-			// call itself. Instead it has one identified by the
-			// resumption point immediately preceding the deferreturn.
-			// The wasm code has a R_ADDR relocation which is used to
-			// set the resumption point to PC_B.
+			// wasm/ssa.go generates an ARESUMEPOINT just
+			// before the deferreturn call. The "PC" of
+			// the deferreturn call is stored in the
+			// R_ADDR relocation on the ARESUMEPOINT.
 			lastWasmAddr = uint32(r.Add())
 		}
 		if r.Type().IsDirectCall() && (r.Sym() == deferReturnSym || ldr.IsDeferReturnTramp(r.Sym())) {
diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
index 3540c07da10..8eb4231c3ab 100644
--- a/src/cmd/link/internal/ld/pe.go
+++ b/src/cmd/link/internal/ld/pe.go
@@ -475,7 +475,7 @@ func (f *peFile) addDWARFSection(name string, size int) *peSection {
 	off := f.stringTable.add(name)
 	h := f.addSection(name, size, size)
 	h.shortName = fmt.Sprintf("/%d", off)
-	h.characteristics = IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_DISCARDABLE | IMAGE_SCN_CNT_INITIALIZED_DATA
+	h.characteristics = IMAGE_SCN_ALIGN_1BYTES | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_DISCARDABLE | IMAGE_SCN_CNT_INITIALIZED_DATA
 	return h
 }
 
diff --git a/src/cmd/link/internal/ld/symtab.go b/src/cmd/link/internal/ld/symtab.go
index 00f557875a9..1f5e333cfd5 100644
--- a/src/cmd/link/internal/ld/symtab.go
+++ b/src/cmd/link/internal/ld/symtab.go
@@ -300,6 +300,7 @@ func putplan9sym(ctxt *Link, ldr *loader.Loader, s loader.Sym, char SymbolType)
 	ctxt.Out.Write8(uint8(t + 0x80)) /* 0x80 is variable length */
 
 	name := ldr.SymName(s)
+	name = mangleABIName(ctxt, ldr, s, name)
 	ctxt.Out.WriteString(name)
 	ctxt.Out.Write8(0)
 
diff --git a/src/cmd/link/internal/loadelf/ldelf.go b/src/cmd/link/internal/loadelf/ldelf.go
index c6956297f6c..b4f565a153f 100644
--- a/src/cmd/link/internal/loadelf/ldelf.go
+++ b/src/cmd/link/internal/loadelf/ldelf.go
@@ -22,7 +22,7 @@ import (
 
 /*
 Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
-http://code.swtch.com/plan9port/src/tip/src/libmach/
+https://github.com/9fans/plan9port/tree/master/src/libmach/
 
 	Copyright © 2004 Russ Cox.
 	Portions Copyright © 2008-2010 Google Inc.
diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index 1b71a66c6f5..9d5319c3120 100644
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -459,6 +459,15 @@ func (st *loadState) addSym(name string, ver int, r *oReader, li uint32, kind in
 		if l.flags&FlagStrictDups != 0 {
 			l.checkdup(name, r, li, oldi)
 		}
+		// Fix for issue #47185 -- given two dupok symbols with
+		// different sizes, favor symbol with larger size. See
+		// also issue #46653.
+		szdup := l.SymSize(oldi)
+		sz := int64(r.Sym(li).Siz())
+		if szdup < sz {
+			// new symbol overwrites old symbol.
+			l.objSyms[oldi] = objSym{r.objidx, li}
+		}
 		return oldi
 	}
 	oldr, oldli := l.toLocal(oldi)
@@ -699,12 +708,18 @@ func (l *Loader) checkdup(name string, r *oReader, li uint32, dup Sym) {
 	p := r.Data(li)
 	rdup, ldup := l.toLocal(dup)
 	pdup := rdup.Data(ldup)
-	if bytes.Equal(p, pdup) {
-		return
-	}
 	reason := "same length but different contents"
 	if len(p) != len(pdup) {
 		reason = fmt.Sprintf("new length %d != old length %d", len(p), len(pdup))
+	} else if bytes.Equal(p, pdup) {
+		// For BSS symbols, we need to check size as well, see issue 46653.
+		szdup := l.SymSize(dup)
+		sz := int64(r.Sym(li).Siz())
+		if szdup == sz {
+			return
+		}
+		reason = fmt.Sprintf("different sizes: new size %d != old size %d",
+			sz, szdup)
 	}
 	fmt.Fprintf(os.Stderr, "cmd/link: while reading object for '%v': duplicate symbol '%s', previous def at '%v', with mismatched payload: %s\n", r.unit.Lib, name, rdup.unit.Lib, reason)
 
diff --git a/src/cmd/link/internal/loadmacho/ldmacho.go b/src/cmd/link/internal/loadmacho/ldmacho.go
index e7d9eebc33f..5402ecd7484 100644
--- a/src/cmd/link/internal/loadmacho/ldmacho.go
+++ b/src/cmd/link/internal/loadmacho/ldmacho.go
@@ -18,7 +18,7 @@ import (
 
 /*
 Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
-http://code.swtch.com/plan9port/src/tip/src/libmach/
+https://github.com/9fans/plan9port/tree/master/src/libmach/
 
 	Copyright © 2004 Russ Cox.
 	Portions Copyright © 2008-2010 Google Inc.
diff --git a/src/cmd/link/link_test.go b/src/cmd/link/link_test.go
index 8805ff1f02c..fed9c7bc3fc 100644
--- a/src/cmd/link/link_test.go
+++ b/src/cmd/link/link_test.go
@@ -470,10 +470,30 @@ TEXT	·f(SB), NOSPLIT|DUPOK, $0-0
 	JMP	0(PC)
 `
 
+const testStrictDupAsmSrc3 = `
+#include "textflag.h"
+GLOBL ·rcon(SB), RODATA|DUPOK, $64
+`
+
+const testStrictDupAsmSrc4 = `
+#include "textflag.h"
+GLOBL ·rcon(SB), RODATA|DUPOK, $32
+`
+
 func TestStrictDup(t *testing.T) {
 	// Check that -strictdups flag works.
 	testenv.MustHaveGoBuild(t)
 
+	asmfiles := []struct {
+		fname   string
+		payload string
+	}{
+		{"a", testStrictDupAsmSrc1},
+		{"b", testStrictDupAsmSrc2},
+		{"c", testStrictDupAsmSrc3},
+		{"d", testStrictDupAsmSrc4},
+	}
+
 	t.Parallel()
 
 	tmpdir := t.TempDir()
@@ -483,15 +503,12 @@ func TestStrictDup(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	src = filepath.Join(tmpdir, "a.s")
-	err = ioutil.WriteFile(src, []byte(testStrictDupAsmSrc1), 0666)
-	if err != nil {
-		t.Fatal(err)
-	}
-	src = filepath.Join(tmpdir, "b.s")
-	err = ioutil.WriteFile(src, []byte(testStrictDupAsmSrc2), 0666)
-	if err != nil {
-		t.Fatal(err)
+	for _, af := range asmfiles {
+		src = filepath.Join(tmpdir, af.fname+".s")
+		err = ioutil.WriteFile(src, []byte(af.payload), 0666)
+		if err != nil {
+			t.Fatal(err)
+		}
 	}
 	src = filepath.Join(tmpdir, "go.mod")
 	err = ioutil.WriteFile(src, []byte("module teststrictdup\n"), 0666)
@@ -503,7 +520,7 @@ func TestStrictDup(t *testing.T) {
 	cmd.Dir = tmpdir
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		t.Errorf("linking with -strictdups=1 failed: %v", err)
+		t.Errorf("linking with -strictdups=1 failed: %v\n%s", err, string(out))
 	}
 	if !bytes.Contains(out, []byte("mismatched payload")) {
 		t.Errorf("unexpected output:\n%s", out)
@@ -515,7 +532,11 @@ func TestStrictDup(t *testing.T) {
 	if err == nil {
 		t.Errorf("linking with -strictdups=2 did not fail")
 	}
-	if !bytes.Contains(out, []byte("mismatched payload")) {
+	// NB: on amd64 we get the 'new length' error, on arm64 the 'different
+	// contents' error.
+	if !(bytes.Contains(out, []byte("mismatched payload: new length")) ||
+		bytes.Contains(out, []byte("mismatched payload: same length but different contents"))) ||
+		!bytes.Contains(out, []byte("mismatched payload: different sizes")) {
 		t.Errorf("unexpected output:\n%s", out)
 	}
 }
@@ -524,14 +545,13 @@ const testFuncAlignSrc = `
 package main
 import (
 	"fmt"
-	"reflect"
 )
 func alignPc()
+var alignPcFnAddr uintptr
 
 func main() {
-	addr := reflect.ValueOf(alignPc).Pointer()
-	if (addr % 512) != 0 {
-		fmt.Printf("expected 512 bytes alignment, got %v\n", addr)
+	if alignPcFnAddr % 512 != 0 {
+		fmt.Printf("expected 512 bytes alignment, got %v\n", alignPcFnAddr)
 	} else {
 		fmt.Printf("PASS")
 	}
@@ -546,6 +566,9 @@ TEXT	·alignPc(SB),NOSPLIT, $0-0
 	PCALIGN	$512
 	MOVD	$3, R1
 	RET
+
+GLOBL	·alignPcFnAddr(SB),RODATA,$8
+DATA	·alignPcFnAddr(SB)/8,$·alignPc(SB)
 `
 
 // TestFuncAlign verifies that the address of a function can be aligned
@@ -698,7 +721,7 @@ func TestTrampolineCgo(t *testing.T) {
 	if err != nil {
 		t.Errorf("executable failed to run: %v\n%s", err, out)
 	}
-	if string(out) != "hello\n" {
+	if string(out) != "hello\n" && string(out) != "hello\r\n" {
 		t.Errorf("unexpected output:\n%s", out)
 	}
 
@@ -717,7 +740,7 @@ func TestTrampolineCgo(t *testing.T) {
 	if err != nil {
 		t.Errorf("executable failed to run: %v\n%s", err, out)
 	}
-	if string(out) != "hello\n" {
+	if string(out) != "hello\n" && string(out) != "hello\r\n" {
 		t.Errorf("unexpected output:\n%s", out)
 	}
 }
diff --git a/src/cmd/pprof/pprof.go b/src/cmd/pprof/pprof.go
index 11f91cbedb9..e72c765adc3 100644
--- a/src/cmd/pprof/pprof.go
+++ b/src/cmd/pprof/pprof.go
@@ -232,9 +232,9 @@ func (f *file) Name() string {
 	return f.name
 }
 
-func (f *file) Base() uint64 {
-	// No support for shared libraries.
-	return 0
+func (f *file) ObjAddr(addr uint64) (uint64, error) {
+	// No support for shared libraries, so translation is a no-op.
+	return addr, nil
 }
 
 func (f *file) BuildID() string {
diff --git a/src/cmd/pprof/pprof_test.go b/src/cmd/pprof/pprof_test.go
new file mode 100644
index 00000000000..11e251bfde2
--- /dev/null
+++ b/src/cmd/pprof/pprof_test.go
@@ -0,0 +1,127 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+var tmp, pprofExe string // populated by buildPprof
+
+func TestMain(m *testing.M) {
+	if !testenv.HasGoBuild() {
+		return
+	}
+
+	var exitcode int
+	if err := buildPprof(); err == nil {
+		exitcode = m.Run()
+	} else {
+		fmt.Println(err)
+		exitcode = 1
+	}
+	os.RemoveAll(tmp)
+	os.Exit(exitcode)
+}
+
+func buildPprof() error {
+	var err error
+	tmp, err = os.MkdirTemp("", "TestPprof")
+	if err != nil {
+		return fmt.Errorf("TempDir failed: %v", err)
+	}
+
+	pprofExe = filepath.Join(tmp, "testpprof.exe")
+	gotool, err := testenv.GoTool()
+	if err != nil {
+		return err
+	}
+	out, err := exec.Command(gotool, "build", "-o", pprofExe, "cmd/pprof").CombinedOutput()
+	if err != nil {
+		os.RemoveAll(tmp)
+		return fmt.Errorf("go build -o %v cmd/pprof: %v\n%s", pprofExe, err, string(out))
+	}
+
+	return nil
+}
+
+// See also runtime/pprof.cpuProfilingBroken.
+func mustHaveCPUProfiling(t *testing.T) {
+	switch runtime.GOOS {
+	case "plan9":
+		t.Skipf("skipping on %s, unimplemented", runtime.GOOS)
+	case "aix":
+		t.Skipf("skipping on %s, issue 45170", runtime.GOOS)
+	case "ios", "dragonfly", "netbsd", "illumos", "solaris":
+		t.Skipf("skipping on %s, issue 13841", runtime.GOOS)
+	case "openbsd":
+		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
+			t.Skipf("skipping on %s/%s, issue 13841", runtime.GOOS, runtime.GOARCH)
+		}
+	}
+}
+
+func mustHaveDisasm(t *testing.T) {
+	switch runtime.GOARCH {
+	case "mips", "mipsle", "mips64", "mips64le":
+		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
+	case "riscv64":
+		t.Skipf("skipping on %s, issue 36738", runtime.GOARCH)
+	case "s390x":
+		t.Skipf("skipping on %s, issue 15255", runtime.GOARCH)
+	}
+
+	// Skip PIE platforms, pprof can't disassemble PIE.
+	if runtime.GOOS == "windows" {
+		t.Skipf("skipping on %s, issue 46639", runtime.GOOS)
+	}
+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
+		t.Skipf("skipping on %s/%s, issue 46639", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
+// TestDisasm verifies that cmd/pprof can successfully disassemble functions.
+//
+// This is a regression test for issue 46636.
+func TestDisasm(t *testing.T) {
+	mustHaveCPUProfiling(t)
+	mustHaveDisasm(t)
+	testenv.MustHaveGoBuild(t)
+
+	tmpdir := t.TempDir()
+	cpuExe := filepath.Join(tmpdir, "cpu.exe")
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", cpuExe, "cpu.go")
+	cmd.Dir = "testdata/"
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("build failed: %v\n%s", err, out)
+	}
+
+	profile := filepath.Join(tmpdir, "cpu.pprof")
+	cmd = exec.Command(cpuExe, "-output", profile)
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("cpu failed: %v\n%s", err, out)
+	}
+
+	cmd = exec.Command(pprofExe, "-disasm", "main.main", cpuExe, profile)
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("pprof failed: %v\n%s", err, out)
+	}
+
+	sout := string(out)
+	want := "ROUTINE ======================== main.main"
+	if !strings.Contains(sout, want) {
+		t.Errorf("pprof disasm got %s want contains %q", sout, want)
+	}
+}
diff --git a/src/cmd/pprof/testdata/cpu.go b/src/cmd/pprof/testdata/cpu.go
new file mode 100644
index 00000000000..5b682870db8
--- /dev/null
+++ b/src/cmd/pprof/testdata/cpu.go
@@ -0,0 +1,41 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime/pprof"
+	"time"
+)
+
+var output = flag.String("output", "", "pprof profile output file")
+
+func main() {
+	flag.Parse()
+	if *output == "" {
+		fmt.Fprintf(os.Stderr, "usage: %s -output file.pprof\n", os.Args[0])
+		os.Exit(2)
+	}
+
+	f, err := os.Create(*output)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(2)
+	}
+	defer f.Close()
+
+	if err := pprof.StartCPUProfile(f); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(2)
+	}
+	defer pprof.StopCPUProfile()
+
+	// Spin for long enough to collect some samples.
+	start := time.Now()
+	for time.Since(start) < time.Second {
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/driver/driver.go b/src/cmd/vendor/github.com/google/pprof/driver/driver.go
index e65bc2f417d..fc05f919baf 100644
--- a/src/cmd/vendor/github.com/google/pprof/driver/driver.go
+++ b/src/cmd/vendor/github.com/google/pprof/driver/driver.go
@@ -159,8 +159,8 @@ type ObjFile interface {
 	// Name returns the underlying file name, if available.
 	Name() string
 
-	// Base returns the base address to use when looking up symbols in the file.
-	Base() uint64
+	// ObjAddr returns the objdump address corresponding to a runtime address.
+	ObjAddr(addr uint64) (uint64, error)
 
 	// BuildID returns the GNU build ID of the file, or an empty string.
 	BuildID() string
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
index 576a6ee66a1..5ed8a1f9f1e 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
@@ -42,7 +42,12 @@ type Binutils struct {
 	rep *binrep
 }
 
-var objdumpLLVMVerRE = regexp.MustCompile(`LLVM version (?:(\d*)\.(\d*)\.(\d*)|.*(trunk).*)`)
+var (
+	objdumpLLVMVerRE = regexp.MustCompile(`LLVM version (?:(\d*)\.(\d*)\.(\d*)|.*(trunk).*)`)
+
+	// Defined for testing
+	elfOpen = elf.Open
+)
 
 // binrep is an immutable representation for Binutils.  It is atomically
 // replaced on every mutation to provide thread-safe access.
@@ -421,14 +426,23 @@ func (b *binrep) openMachO(name string, start, limit, offset uint64) (plugin.Obj
 }
 
 func (b *binrep) openELF(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
-	ef, err := elf.Open(name)
+	ef, err := elfOpen(name)
 	if err != nil {
 		return nil, fmt.Errorf("error parsing %s: %v", name, err)
 	}
 	defer ef.Close()
 
-	var stextOffset *uint64
-	var pageAligned = func(addr uint64) bool { return addr%4096 == 0 }
+	buildID := ""
+	if f, err := os.Open(name); err == nil {
+		if id, err := elfexec.GetBuildID(f); err == nil {
+			buildID = fmt.Sprintf("%x", id)
+		}
+	}
+
+	var (
+		stextOffset *uint64
+		pageAligned = func(addr uint64) bool { return addr%4096 == 0 }
+	)
 	if strings.Contains(name, "vmlinux") || !pageAligned(start) || !pageAligned(limit) || !pageAligned(offset) {
 		// Reading all Symbols is expensive, and we only rarely need it so
 		// we don't want to do it every time. But if _stext happens to be
@@ -450,38 +464,29 @@ func (b *binrep) openELF(name string, start, limit, offset uint64) (plugin.ObjFi
 		}
 	}
 
-	var ph *elf.ProgHeader
-	// For user space executables, find the actual program segment that is
-	// associated with the given mapping. Skip this search if limit <= start.
-	// We cannot use just a check on the start address of the mapping to tell if
-	// it's a kernel / .ko module mapping, because with quipper address remapping
-	// enabled, the address would be in the lower half of the address space.
-	if stextOffset == nil && start < limit && limit < (uint64(1)<<63) {
-		ph, err = elfexec.FindProgHeaderForMapping(ef, offset, limit-start)
-		if err != nil {
-			return nil, fmt.Errorf("failed to find program header for file %q, mapping pgoff %x, memsz=%x: %v", name, offset, limit-start, err)
-		}
-	} else {
-		// For the kernel, find the program segment that includes the .text section.
-		ph = elfexec.FindTextProgHeader(ef)
-	}
-
-	base, err := elfexec.GetBase(&ef.FileHeader, ph, stextOffset, start, limit, offset)
-	if err != nil {
+	// Check that we can compute a base for the binary. This may not be the
+	// correct base value, so we don't save it. We delay computing the actual base
+	// value until we have a sample address for this mapping, so that we can
+	// correctly identify the associated program segment that is needed to compute
+	// the base.
+	if _, err := elfexec.GetBase(&ef.FileHeader, elfexec.FindTextProgHeader(ef), stextOffset, start, limit, offset); err != nil {
 		return nil, fmt.Errorf("could not identify base for %s: %v", name, err)
 	}
 
-	buildID := ""
-	if f, err := os.Open(name); err == nil {
-		if id, err := elfexec.GetBuildID(f); err == nil {
-			buildID = fmt.Sprintf("%x", id)
-		}
-	}
-	isData := ph != nil && ph.Flags&elf.PF_X == 0
 	if b.fast || (!b.addr2lineFound && !b.llvmSymbolizerFound) {
-		return &fileNM{file: file{b, name, base, buildID, isData}}, nil
+		return &fileNM{file: file{
+			b:       b,
+			name:    name,
+			buildID: buildID,
+			m:       &elfMapping{start: start, limit: limit, offset: offset, stextOffset: stextOffset},
+		}}, nil
 	}
-	return &fileAddr2Line{file: file{b, name, base, buildID, isData}}, nil
+	return &fileAddr2Line{file: file{
+		b:       b,
+		name:    name,
+		buildID: buildID,
+		m:       &elfMapping{start: start, limit: limit, offset: offset, stextOffset: stextOffset},
+	}}, nil
 }
 
 func (b *binrep) openPE(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
@@ -511,21 +516,119 @@ func (b *binrep) openPE(name string, start, limit, offset uint64) (plugin.ObjFil
 	return &fileAddr2Line{file: file{b: b, name: name, base: base}}, nil
 }
 
+// elfMapping stores the parameters of a runtime mapping that are needed to
+// identify the ELF segment associated with a mapping.
+type elfMapping struct {
+	// Runtime mapping parameters.
+	start, limit, offset uint64
+	// Offset of _stext symbol. Only defined for kernel images, nil otherwise.
+	stextOffset *uint64
+}
+
 // file implements the binutils.ObjFile interface.
 type file struct {
 	b       *binrep
 	name    string
-	base    uint64
 	buildID string
-	isData  bool
+
+	baseOnce sync.Once // Ensures the base, baseErr and isData are computed once.
+	base     uint64
+	baseErr  error // Any eventual error while computing the base.
+	isData   bool
+	// Mapping information. Relevant only for ELF files, nil otherwise.
+	m *elfMapping
+}
+
+// computeBase computes the relocation base for the given binary file only if
+// the elfMapping field is set. It populates the base and isData fields and
+// returns an error.
+func (f *file) computeBase(addr uint64) error {
+	if f == nil || f.m == nil {
+		return nil
+	}
+	if addr < f.m.start || addr >= f.m.limit {
+		return fmt.Errorf("specified address %x is outside the mapping range [%x, %x] for file %q", addr, f.m.start, f.m.limit, f.name)
+	}
+	ef, err := elfOpen(f.name)
+	if err != nil {
+		return fmt.Errorf("error parsing %s: %v", f.name, err)
+	}
+	defer ef.Close()
+
+	var ph *elf.ProgHeader
+	// For user space executables, find the actual program segment that is
+	// associated with the given mapping. Skip this search if limit <= start.
+	// We cannot use just a check on the start address of the mapping to tell if
+	// it's a kernel / .ko module mapping, because with quipper address remapping
+	// enabled, the address would be in the lower half of the address space.
+	if f.m.stextOffset == nil && f.m.start < f.m.limit && f.m.limit < (uint64(1)<<63) {
+		// Get all program headers associated with the mapping.
+		headers, hasLoadables := elfexec.ProgramHeadersForMapping(ef, f.m.offset, f.m.limit-f.m.start)
+
+		// Some ELF files don't contain any loadable program segments, e.g. .ko
+		// kernel modules. It's not an error to have no header in such cases.
+		if hasLoadables {
+			ph, err = matchUniqueHeader(headers, addr-f.m.start+f.m.offset)
+			if err != nil {
+				return fmt.Errorf("failed to find program header for file %q, ELF mapping %#v, address %x: %v", f.name, *f.m, addr, err)
+			}
+		}
+	} else {
+		// For the kernel, find the program segment that includes the .text section.
+		ph = elfexec.FindTextProgHeader(ef)
+	}
+
+	base, err := elfexec.GetBase(&ef.FileHeader, ph, f.m.stextOffset, f.m.start, f.m.limit, f.m.offset)
+	if err != nil {
+		return err
+	}
+	f.base = base
+	f.isData = ph != nil && ph.Flags&elf.PF_X == 0
+	return nil
+}
+
+// matchUniqueHeader attempts to identify a unique header from the given list,
+// using the given file offset to disambiguate between multiple segments. It
+// returns an error if the header list is empty or if it cannot identify a
+// unique header.
+func matchUniqueHeader(headers []*elf.ProgHeader, fileOffset uint64) (*elf.ProgHeader, error) {
+	if len(headers) == 0 {
+		return nil, errors.New("no program header matches mapping info")
+	}
+	if len(headers) == 1 {
+		// Don't use the file offset if we already have a single header.
+		return headers[0], nil
+	}
+	// We have multiple input segments. Attempt to identify a unique one
+	// based on the given file offset.
+	var ph *elf.ProgHeader
+	for _, h := range headers {
+		if fileOffset >= h.Off && fileOffset < h.Off+h.Memsz {
+			if ph != nil {
+				// Assuming no other bugs, this can only happen if we have two or
+				// more small program segments that fit on the same page, and a
+				// segment other than the last one includes uninitialized data.
+				return nil, fmt.Errorf("found second program header (%#v) that matches file offset %x, first program header is %#v. Does first program segment contain uninitialized data?", *h, fileOffset, *ph)
+			}
+			ph = h
+		}
+	}
+	if ph == nil {
+		return nil, fmt.Errorf("no program header matches file offset %x", fileOffset)
+	}
+	return ph, nil
 }
 
 func (f *file) Name() string {
 	return f.name
 }
 
-func (f *file) Base() uint64 {
-	return f.base
+func (f *file) ObjAddr(addr uint64) (uint64, error) {
+	f.baseOnce.Do(func() { f.baseErr = f.computeBase(addr) })
+	if f.baseErr != nil {
+		return 0, f.baseErr
+	}
+	return addr - f.base, nil
 }
 
 func (f *file) BuildID() string {
@@ -533,7 +636,11 @@ func (f *file) BuildID() string {
 }
 
 func (f *file) SourceLine(addr uint64) ([]plugin.Frame, error) {
-	return []plugin.Frame{}, nil
+	f.baseOnce.Do(func() { f.baseErr = f.computeBase(addr) })
+	if f.baseErr != nil {
+		return nil, f.baseErr
+	}
+	return nil, nil
 }
 
 func (f *file) Close() error {
@@ -560,6 +667,10 @@ type fileNM struct {
 }
 
 func (f *fileNM) SourceLine(addr uint64) ([]plugin.Frame, error) {
+	f.baseOnce.Do(func() { f.baseErr = f.computeBase(addr) })
+	if f.baseErr != nil {
+		return nil, f.baseErr
+	}
 	if f.addr2linernm == nil {
 		addr2liner, err := newAddr2LinerNM(f.b.nm, f.name, f.base)
 		if err != nil {
@@ -579,9 +690,14 @@ type fileAddr2Line struct {
 	file
 	addr2liner     *addr2Liner
 	llvmSymbolizer *llvmSymbolizer
+	isData         bool
 }
 
 func (f *fileAddr2Line) SourceLine(addr uint64) ([]plugin.Frame, error) {
+	f.baseOnce.Do(func() { f.baseErr = f.computeBase(addr) })
+	if f.baseErr != nil {
+		return nil, f.baseErr
+	}
 	f.once.Do(f.init)
 	if f.llvmSymbolizer != nil {
 		return f.llvmSymbolizer.addrInfo(addr)
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
index 3b3c6ee89ff..2638b2db2d9 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
@@ -284,83 +284,71 @@ func FindTextProgHeader(f *elf.File) *elf.ProgHeader {
 	return nil
 }
 
-// FindProgHeaderForMapping returns the loadable program segment header that is
-// fully contained in the runtime mapping with file offset pgoff and memory size
-// memsz, or an error if the segment cannot be determined. The function returns
-// a nil program header and no error if the ELF binary has no loadable segments.
-func FindProgHeaderForMapping(f *elf.File, pgoff, memsz uint64) (*elf.ProgHeader, error) {
+// ProgramHeadersForMapping returns the loadable program segment headers that
+// are fully contained in the runtime mapping with file offset pgoff and memory
+// size memsz, and if the binary includes any loadable segments.
+func ProgramHeadersForMapping(f *elf.File, pgoff, memsz uint64) ([]*elf.ProgHeader, bool) {
+	const (
+		// pageSize defines the virtual memory page size used by the loader. This
+		// value is dependent on the memory management unit of the CPU. The page
+		// size is 4KB virtually on all the architectures that we care about, so we
+		// define this metric as a constant. If we encounter architectures where
+		// page sie is not 4KB, we must try to guess the page size on the system
+		// where the profile was collected, possibly using the architecture
+		// specified in the ELF file header.
+		pageSize       = 4096
+		pageOffsetMask = pageSize - 1
+		pageMask       = ^uint64(pageOffsetMask)
+	)
 	var headers []*elf.ProgHeader
-	loadables := 0
+	hasLoadables := false
 	for _, p := range f.Progs {
+		// The segment must be fully included in the mapping.
 		if p.Type == elf.PT_LOAD && pgoff <= p.Off && p.Off+p.Memsz <= pgoff+memsz {
-			headers = append(headers, &p.ProgHeader)
+			alignedOffset := uint64(0)
+			if p.Off > (p.Vaddr & pageOffsetMask) {
+				alignedOffset = p.Off - (p.Vaddr & pageOffsetMask)
+			}
+			if alignedOffset <= pgoff {
+				headers = append(headers, &p.ProgHeader)
+			}
 		}
 		if p.Type == elf.PT_LOAD {
-			loadables++
+			hasLoadables = true
 		}
 	}
-	if len(headers) == 1 {
-		return headers[0], nil
-	}
-	// Some ELF files don't contain any program segments, e.g. .ko loadable kernel
-	// modules. Don't return an error in such cases.
-	if loadables == 0 {
-		return nil, nil
-	}
-	if len(headers) == 0 {
-		return nil, fmt.Errorf("no program header matches file offset %x and memory size %x", pgoff, memsz)
+	if len(headers) < 2 {
+		return headers, hasLoadables
 	}
 
-	// Segments are mapped page aligned. In some cases, segments may be smaller
-	// than a page, which causes the next segment to start at a file offset that
-	// is logically on the same page if we were to align file offsets by page.
-	// Example:
-	//  LOAD           0x0000000000000000 0x0000000000400000 0x0000000000400000
-	//                 0x00000000000006fc 0x00000000000006fc  R E    0x200000
-	//  LOAD           0x0000000000000e10 0x0000000000600e10 0x0000000000600e10
-	//                 0x0000000000000230 0x0000000000000238  RW     0x200000
-	//
-	// In this case, perf records the following mappings for this executable:
-	// 0 0 [0xc0]: PERF_RECORD_MMAP2 87867/87867: [0x400000(0x1000) @ 0 00:3c 512041 0]: r-xp exename
-	// 0 0 [0xc0]: PERF_RECORD_MMAP2 87867/87867: [0x600000(0x2000) @ 0 00:3c 512041 0]: rw-p exename
-	//
-	// Both mappings have file offset 0. The first mapping is one page length and
-	// it can include only the first loadable segment. Due to page alignment, the
-	// second mapping starts also at file offset 0, and it spans two pages. It can
-	// include both the first and the second loadable segments. We must return the
-	// correct program header to compute the correct base offset.
-	//
-	// We cannot use the mapping protections to distinguish between segments,
-	// because protections are not passed through to this function.
-	// We cannot use the start address to differentiate between segments, because
-	// with ASLR, the mapping start address can be any value.
-	//
-	// We use a heuristic to compute the minimum mapping size required for a
-	// segment, assuming mappings are 4k page aligned, and return the segment that
-	// matches the given mapping size.
-	const pageSize = 4096
-
+	// If we have more than one matching segments, try a strict check on the
+	// segment memory size. We use a heuristic to compute the minimum mapping size
+	// required for a segment, assuming mappings are page aligned.
 	// The memory size based heuristic makes sense only if the mapping size is a
-	// multiple of 4k page size.
+	// multiple of page size.
 	if memsz%pageSize != 0 {
-		return nil, fmt.Errorf("mapping size = %x and %d segments match the passed in mapping", memsz, len(headers))
+		return headers, hasLoadables
 	}
 
-	// Return an error if no segment, or multiple segments match the size, so we can debug.
+	// Return all found headers if we cannot narrow the selection to a single
+	// program segment.
 	var ph *elf.ProgHeader
-	pageMask := ^uint64(pageSize - 1)
 	for _, h := range headers {
 		wantSize := (h.Vaddr+h.Memsz+pageSize-1)&pageMask - (h.Vaddr & pageMask)
 		if wantSize != memsz {
 			continue
 		}
 		if ph != nil {
-			return nil, fmt.Errorf("found second program header (%#v) that matches memsz %x, first program header is %#v", *h, memsz, *ph)
+			// Found a second program header matching, so return all previously
+			// identified headers.
+			return headers, hasLoadables
 		}
 		ph = h
 	}
 	if ph == nil {
-		return nil, fmt.Errorf("found %d matching program headers, but none matches mapping size %x", len(headers), memsz)
+		// No matching header for the strict check. Return all previously identified
+		// headers.
+		return headers, hasLoadables
 	}
-	return ph, nil
+	return []*elf.ProgHeader{ph}, hasLoadables
 }
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go b/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go
index 3a8d0af7305..a57a0b20a96 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go
@@ -131,8 +131,9 @@ type ObjFile interface {
 	// Name returns the underlyinf file name, if available
 	Name() string
 
-	// Base returns the base address to use when looking up symbols in the file.
-	Base() uint64
+	// ObjAddr returns the objdump (linker) address corresponding to a runtime
+	// address, and an error.
+	ObjAddr(addr uint64) (uint64, error)
 
 	// BuildID returns the GNU build ID of the file, or an empty string.
 	BuildID() string
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/report.go b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
index bc5685d61e1..4a865548801 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
@@ -445,7 +445,7 @@ func PrintAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFuncs int) e
 			return err
 		}
 
-		ns := annotateAssembly(insts, sns, s.base)
+		ns := annotateAssembly(insts, sns, s.file)
 
 		fmt.Fprintf(w, "ROUTINE ======================== %s\n", s.sym.Name[0])
 		for _, name := range s.sym.Name[1:] {
@@ -534,7 +534,6 @@ func symbolsFromBinaries(prof *profile.Profile, g *graph.Graph, rx *regexp.Regex
 			addr = *address
 		}
 		msyms, err := f.Symbols(rx, addr)
-		base := f.Base()
 		f.Close()
 		if err != nil {
 			continue
@@ -543,7 +542,6 @@ func symbolsFromBinaries(prof *profile.Profile, g *graph.Graph, rx *regexp.Regex
 			objSyms = append(objSyms,
 				&objSymbol{
 					sym:  ms,
-					base: base,
 					file: f,
 				},
 			)
@@ -558,7 +556,6 @@ func symbolsFromBinaries(prof *profile.Profile, g *graph.Graph, rx *regexp.Regex
 // added to correspond to sample addresses
 type objSymbol struct {
 	sym  *plugin.Sym
-	base uint64
 	file plugin.ObjFile
 }
 
@@ -578,8 +575,7 @@ func nodesPerSymbol(ns graph.Nodes, symbols []*objSymbol) map[*objSymbol]graph.N
 	for _, s := range symbols {
 		// Gather samples for this symbol.
 		for _, n := range ns {
-			address := n.Info.Address - s.base
-			if address >= s.sym.Start && address < s.sym.End {
+			if address, err := s.file.ObjAddr(n.Info.Address); err == nil && address >= s.sym.Start && address < s.sym.End {
 				symNodes[s] = append(symNodes[s], n)
 			}
 		}
@@ -621,7 +617,7 @@ func (a *assemblyInstruction) cumValue() int64 {
 // annotateAssembly annotates a set of assembly instructions with a
 // set of samples. It returns a set of nodes to display. base is an
 // offset to adjust the sample addresses.
-func annotateAssembly(insts []plugin.Inst, samples graph.Nodes, base uint64) []assemblyInstruction {
+func annotateAssembly(insts []plugin.Inst, samples graph.Nodes, file plugin.ObjFile) []assemblyInstruction {
 	// Add end marker to simplify printing loop.
 	insts = append(insts, plugin.Inst{
 		Addr: ^uint64(0),
@@ -645,7 +641,10 @@ func annotateAssembly(insts []plugin.Inst, samples graph.Nodes, base uint64) []a
 
 		// Sum all the samples until the next instruction (to account
 		// for samples attributed to the middle of an instruction).
-		for next := insts[ix+1].Addr; s < len(samples) && samples[s].Info.Address-base < next; s++ {
+		for next := insts[ix+1].Addr; s < len(samples); s++ {
+			if addr, err := file.ObjAddr(samples[s].Info.Address); err != nil || addr >= next {
+				break
+			}
 			sample := samples[s]
 			n.flatDiv += sample.FlatDiv
 			n.flat += sample.Flat
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/source.go b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
index 4f841eff5dc..54245e5f9ea 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
@@ -132,6 +132,7 @@ func printWebSource(w io.Writer, rpt *Report, obj plugin.ObjTool) error {
 // sourcePrinter holds state needed for generating source+asm HTML listing.
 type sourcePrinter struct {
 	reader     *sourceReader
+	synth      *synthCode
 	objectTool plugin.ObjTool
 	objects    map[string]plugin.ObjFile  // Opened object files
 	sym        *regexp.Regexp             // May be nil
@@ -146,6 +147,12 @@ type sourcePrinter struct {
 	prettyNames map[string]string
 }
 
+// addrInfo holds information for an address we are interested in.
+type addrInfo struct {
+	loc *profile.Location // Always non-nil
+	obj plugin.ObjFile    // May be nil
+}
+
 // instructionInfo holds collected information for an instruction.
 type instructionInfo struct {
 	objAddr   uint64 // Address in object file (with base subtracted out)
@@ -207,6 +214,7 @@ func PrintWebList(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFiles int) er
 func newSourcePrinter(rpt *Report, obj plugin.ObjTool, sourcePath string) *sourcePrinter {
 	sp := &sourcePrinter{
 		reader:      newSourceReader(sourcePath, rpt.options.TrimPath),
+		synth:       newSynthCode(rpt.prof.Mapping),
 		objectTool:  obj,
 		objects:     map[string]plugin.ObjFile{},
 		sym:         rpt.options.Symbol,
@@ -225,19 +233,21 @@ func newSourcePrinter(rpt *Report, obj plugin.ObjTool, sourcePath string) *sourc
 		}
 	}
 
-	addrs := map[uint64]bool{}
+	addrs := map[uint64]addrInfo{}
 	flat := map[uint64]int64{}
 	cum := map[uint64]int64{}
 
 	// Record an interest in the function corresponding to lines[index].
-	markInterest := func(addr uint64, lines []profile.Line, index int) {
-		fn := lines[index]
+	markInterest := func(addr uint64, loc *profile.Location, index int) {
+		fn := loc.Line[index]
 		if fn.Function == nil {
 			return
 		}
 		sp.interest[fn.Function.Name] = true
 		sp.interest[fn.Function.SystemName] = true
-		addrs[addr] = true
+		if _, ok := addrs[addr]; !ok {
+			addrs[addr] = addrInfo{loc, sp.objectFile(loc.Mapping)}
+		}
 	}
 
 	// See if sp.sym matches line.
@@ -270,15 +280,21 @@ func newSourcePrinter(rpt *Report, obj plugin.ObjTool, sourcePath string) *sourc
 				sp.prettyNames[line.Function.SystemName] = line.Function.Name
 			}
 
-			cum[loc.Address] += value
-			if i == 0 {
-				flat[loc.Address] += value
+			addr := loc.Address
+			if addr == 0 {
+				// Some profiles are missing valid addresses.
+				addr = sp.synth.address(loc)
 			}
 
-			if sp.sym == nil || (address != nil && loc.Address == *address) {
+			cum[addr] += value
+			if i == 0 {
+				flat[addr] += value
+			}
+
+			if sp.sym == nil || (address != nil && addr == *address) {
 				// Interested in top-level entry of stack.
 				if len(loc.Line) > 0 {
-					markInterest(loc.Address, loc.Line, len(loc.Line)-1)
+					markInterest(addr, loc, len(loc.Line)-1)
 				}
 				continue
 			}
@@ -287,7 +303,7 @@ func newSourcePrinter(rpt *Report, obj plugin.ObjTool, sourcePath string) *sourc
 			matchFile := (loc.Mapping != nil && sp.sym.MatchString(loc.Mapping.File))
 			for j, line := range loc.Line {
 				if (j == 0 && matchFile) || matches(line) {
-					markInterest(loc.Address, loc.Line, j)
+					markInterest(addr, loc, j)
 				}
 			}
 		}
@@ -306,10 +322,11 @@ func (sp *sourcePrinter) close() {
 	}
 }
 
-func (sp *sourcePrinter) expandAddresses(rpt *Report, addrs map[uint64]bool, flat map[uint64]int64) {
+func (sp *sourcePrinter) expandAddresses(rpt *Report, addrs map[uint64]addrInfo, flat map[uint64]int64) {
 	// We found interesting addresses (ones with non-zero samples) above.
 	// Get covering address ranges and disassemble the ranges.
-	ranges := sp.splitIntoRanges(rpt.prof, addrs, flat)
+	ranges, unprocessed := sp.splitIntoRanges(rpt.prof, addrs, flat)
+	sp.handleUnprocessed(addrs, unprocessed)
 
 	// Trim ranges if there are too many.
 	const maxRanges = 25
@@ -321,9 +338,18 @@ func (sp *sourcePrinter) expandAddresses(rpt *Report, addrs map[uint64]bool, fla
 	}
 
 	for _, r := range ranges {
-		base := r.obj.Base()
-		insts, err := sp.objectTool.Disasm(r.mapping.File, r.begin-base, r.end-base,
-			rpt.options.IntelSyntax)
+		objBegin, err := r.obj.ObjAddr(r.begin)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to compute objdump address for range start %x: %v\n", r.begin, err)
+			continue
+		}
+		objEnd, err := r.obj.ObjAddr(r.end)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to compute objdump address for range end %x: %v\n", r.end, err)
+			continue
+		}
+		base := r.begin - objBegin
+		insts, err := sp.objectTool.Disasm(r.mapping.File, objBegin, objEnd, rpt.options.IntelSyntax)
 		if err != nil {
 			// TODO(sanjay): Report that the covered addresses are missing.
 			continue
@@ -385,78 +411,115 @@ func (sp *sourcePrinter) expandAddresses(rpt *Report, addrs map[uint64]bool, fla
 				frames = lastFrames
 			}
 
-			// See if the stack contains a function we are interested in.
-			for i, f := range frames {
-				if !sp.interest[f.Func] {
-					continue
-				}
-
-				// Record sub-stack under frame's file/line.
-				fname := canonicalizeFileName(f.File)
-				file := sp.files[fname]
-				if file == nil {
-					file = &sourceFile{
-						fname:    fname,
-						lines:    map[int][]sourceInst{},
-						funcName: map[int]string{},
-					}
-					sp.files[fname] = file
-				}
-				callees := frames[:i]
-				stack := make([]callID, 0, len(callees))
-				for j := len(callees) - 1; j >= 0; j-- { // Reverse so caller is first
-					stack = append(stack, callID{
-						file: callees[j].File,
-						line: callees[j].Line,
-					})
-				}
-				file.lines[f.Line] = append(file.lines[f.Line], sourceInst{addr, stack})
-
-				// Remember the first function name encountered per source line
-				// and assume that that line belongs to that function.
-				if _, ok := file.funcName[f.Line]; !ok {
-					file.funcName[f.Line] = f.Func
-				}
-			}
+			sp.addStack(addr, frames)
 		}
 	}
 }
 
-// splitIntoRanges converts the set of addresses we are interested in into a set of address
-// ranges to disassemble.
-func (sp *sourcePrinter) splitIntoRanges(prof *profile.Profile, set map[uint64]bool, flat map[uint64]int64) []addressRange {
-	// List of mappings so we can stop expanding address ranges at mapping boundaries.
-	mappings := append([]*profile.Mapping{}, prof.Mapping...)
-	sort.Slice(mappings, func(i, j int) bool { return mappings[i].Start < mappings[j].Start })
+func (sp *sourcePrinter) addStack(addr uint64, frames []plugin.Frame) {
+	// See if the stack contains a function we are interested in.
+	for i, f := range frames {
+		if !sp.interest[f.Func] {
+			continue
+		}
 
-	var result []addressRange
-	addrs := make([]uint64, 0, len(set))
-	for addr := range set {
-		addrs = append(addrs, addr)
+		// Record sub-stack under frame's file/line.
+		fname := canonicalizeFileName(f.File)
+		file := sp.files[fname]
+		if file == nil {
+			file = &sourceFile{
+				fname:    fname,
+				lines:    map[int][]sourceInst{},
+				funcName: map[int]string{},
+			}
+			sp.files[fname] = file
+		}
+		callees := frames[:i]
+		stack := make([]callID, 0, len(callees))
+		for j := len(callees) - 1; j >= 0; j-- { // Reverse so caller is first
+			stack = append(stack, callID{
+				file: callees[j].File,
+				line: callees[j].Line,
+			})
+		}
+		file.lines[f.Line] = append(file.lines[f.Line], sourceInst{addr, stack})
+
+		// Remember the first function name encountered per source line
+		// and assume that that line belongs to that function.
+		if _, ok := file.funcName[f.Line]; !ok {
+			file.funcName[f.Line] = f.Func
+		}
+	}
+}
+
+// synthAsm is the special disassembler value used for instructions without an object file.
+const synthAsm = ""
+
+// handleUnprocessed handles addresses that were skipped by splitIntoRanges because they
+// did not belong to a known object file.
+func (sp *sourcePrinter) handleUnprocessed(addrs map[uint64]addrInfo, unprocessed []uint64) {
+	// makeFrames synthesizes a []plugin.Frame list for the specified address.
+	// The result will typically have length 1, but may be longer if address corresponds
+	// to inlined calls.
+	makeFrames := func(addr uint64) []plugin.Frame {
+		loc := addrs[addr].loc
+		stack := make([]plugin.Frame, 0, len(loc.Line))
+		for _, line := range loc.Line {
+			fn := line.Function
+			if fn == nil {
+				continue
+			}
+			stack = append(stack, plugin.Frame{
+				Func: fn.Name,
+				File: fn.Filename,
+				Line: int(line.Line),
+			})
+		}
+		return stack
+	}
+
+	for _, addr := range unprocessed {
+		frames := makeFrames(addr)
+		x := instructionInfo{
+			objAddr: addr,
+			length:  1,
+			disasm:  synthAsm,
+		}
+		if len(frames) > 0 {
+			x.file = frames[0].File
+			x.line = frames[0].Line
+		}
+		sp.insts[addr] = x
+
+		sp.addStack(addr, frames)
+	}
+}
+
+// splitIntoRanges converts the set of addresses we are interested in into a set of address
+// ranges to disassemble. It also returns the set of addresses found that did not have an
+// associated object file and were therefore not added to an address range.
+func (sp *sourcePrinter) splitIntoRanges(prof *profile.Profile, addrMap map[uint64]addrInfo, flat map[uint64]int64) ([]addressRange, []uint64) {
+	// Partition addresses into two sets: ones with a known object file, and ones without.
+	var addrs, unprocessed []uint64
+	for addr, info := range addrMap {
+		if info.obj != nil {
+			addrs = append(addrs, addr)
+		} else {
+			unprocessed = append(unprocessed, addr)
+		}
 	}
 	sort.Slice(addrs, func(i, j int) bool { return addrs[i] < addrs[j] })
 
-	mappingIndex := 0
 	const expand = 500 // How much to expand range to pick up nearby addresses.
+	var result []addressRange
 	for i, n := 0, len(addrs); i < n; {
 		begin, end := addrs[i], addrs[i]
 		sum := flat[begin]
 		i++
 
-		// Advance to mapping containing addrs[i]
-		for mappingIndex < len(mappings) && mappings[mappingIndex].Limit <= begin {
-			mappingIndex++
-		}
-		if mappingIndex >= len(mappings) {
-			// TODO(sanjay): Report missed address and its samples.
-			break
-		}
-		m := mappings[mappingIndex]
-		obj := sp.objectFile(m)
-		if obj == nil {
-			// TODO(sanjay): Report missed address and its samples.
-			continue
-		}
+		info := addrMap[begin]
+		m := info.loc.Mapping
+		obj := info.obj // Non-nil because of the partitioning done above.
 
 		// Find following addresses that are close enough to addrs[i].
 		for i < n && addrs[i] <= end+2*expand && addrs[i] < m.Limit {
@@ -479,7 +542,7 @@ func (sp *sourcePrinter) splitIntoRanges(prof *profile.Profile, set map[uint64]b
 
 		result = append(result, addressRange{begin, end, obj, m, sum})
 	}
-	return result
+	return result, unprocessed
 }
 
 func (sp *sourcePrinter) initSamples(flat, cum map[uint64]int64) {
@@ -665,9 +728,12 @@ func (sp *sourcePrinter) functions(f *sourceFile) []sourceFunction {
 	return funcs
 }
 
-// objectFile return the object for the named file, opening it if necessary.
+// objectFile return the object for the specified mapping, opening it if necessary.
 // It returns nil on error.
 func (sp *sourcePrinter) objectFile(m *profile.Mapping) plugin.ObjFile {
+	if m == nil {
+		return nil
+	}
 	if object, ok := sp.objects[m.File]; ok {
 		return object // May be nil if we detected an error earlier.
 	}
@@ -725,12 +791,28 @@ func printFunctionSourceLine(w io.Writer, lineNo int, flat, cum int64, lineConte
 		return
 	}
 
+	nestedInfo := false
+	cl := "deadsrc"
+	for _, an := range assembly {
+		if len(an.inlineCalls) > 0 || an.instruction != synthAsm {
+			nestedInfo = true
+			cl = "livesrc"
+		}
+	}
+
 	fmt.Fprintf(w,
-		" %6d   %10s %10s %8s  %s ",
-		lineNo,
+		" %6d   %10s %10s %8s  %s ",
+		lineNo, cl,
 		valueOrDot(flat, rpt), valueOrDot(cum, rpt),
 		"", template.HTMLEscapeString(lineContents))
-	srcIndent := indentation(lineContents)
+	if nestedInfo {
+		srcIndent := indentation(lineContents)
+		printNested(w, srcIndent, assembly, reader, rpt)
+	}
+	fmt.Fprintln(w)
+}
+
+func printNested(w io.Writer, srcIndent int, assembly []assemblyInstruction, reader *sourceReader, rpt *Report) {
 	fmt.Fprint(w, "")
 	var curCalls []callID
 	for i, an := range assembly {
@@ -763,6 +845,9 @@ func printFunctionSourceLine(w io.Writer, lineNo int, flat, cum int64, lineConte
 				template.HTMLEscapeString(filepath.Base(c.file)), c.line)
 		}
 		curCalls = an.inlineCalls
+		if an.instruction == synthAsm {
+			continue
+		}
 		text := strings.Repeat(" ", srcIndent+4+4*len(curCalls)) + an.instruction
 		fmt.Fprintf(w, " %8s %10s %10s %8x: %s %s\n",
 			"", valueOrDot(flat, rpt), valueOrDot(cum, rpt), an.address,
@@ -772,7 +857,7 @@ func printFunctionSourceLine(w io.Writer, lineNo int, flat, cum int64, lineConte
 			// would cause double-escaping of file name.
 			fileline)
 	}
-	fmt.Fprintln(w, "")
+	fmt.Fprint(w, "")
 }
 
 // printFunctionClosing prints the end of a function in a weblist report.
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go b/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go
index 26e8bdbba8a..17c9f6eb947 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go
@@ -40,14 +40,7 @@ h1 {
 .inlinesrc {
   color: #000066;
 }
-.deadsrc {
-cursor: pointer;
-}
-.deadsrc:hover {
-background-color: #eeeeee;
-}
 .livesrc {
-color: #0000ff;
 cursor: pointer;
 }
 .livesrc:hover {
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/synth.go b/src/cmd/vendor/github.com/google/pprof/internal/report/synth.go
new file mode 100644
index 00000000000..7a35bbcda8f
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/synth.go
@@ -0,0 +1,39 @@
+package report
+
+import (
+	"github.com/google/pprof/profile"
+)
+
+// synthCode assigns addresses to locations without an address.
+type synthCode struct {
+	next uint64
+	addr map[*profile.Location]uint64 // Synthesized address assigned to a location
+}
+
+func newSynthCode(mappings []*profile.Mapping) *synthCode {
+	// Find a larger address than any mapping.
+	s := &synthCode{next: 1}
+	for _, m := range mappings {
+		if s.next < m.Limit {
+			s.next = m.Limit
+		}
+	}
+	return s
+}
+
+// address returns the synthetic address for loc, creating one if needed.
+func (s *synthCode) address(loc *profile.Location) uint64 {
+	if loc.Address != 0 {
+		panic("can only synthesize addresses for locations without an address")
+	}
+	if addr, ok := s.addr[loc]; ok {
+		return addr
+	}
+	if s.addr == nil {
+		s.addr = map[*profile.Location]uint64{}
+	}
+	addr := s.next
+	s.next++
+	s.addr[loc] = addr
+	return addr
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/encode.go b/src/cmd/vendor/github.com/google/pprof/profile/encode.go
index 1e84c72d43d..ab7f03ae267 100644
--- a/src/cmd/vendor/github.com/google/pprof/profile/encode.go
+++ b/src/cmd/vendor/github.com/google/pprof/profile/encode.go
@@ -308,7 +308,7 @@ func (p *Profile) postDecode() error {
 			if l.strX != 0 {
 				value, err = getString(p.stringTable, &l.strX, err)
 				labels[key] = append(labels[key], value)
-			} else if l.numX != 0 {
+			} else if l.numX != 0 || l.unitX != 0 {
 				numValues := numLabels[key]
 				units := numUnits[key]
 				if l.unitX != 0 {
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/merge.go b/src/cmd/vendor/github.com/google/pprof/profile/merge.go
index 5ab6e9b9b08..9978e7330e6 100644
--- a/src/cmd/vendor/github.com/google/pprof/profile/merge.go
+++ b/src/cmd/vendor/github.com/google/pprof/profile/merge.go
@@ -231,7 +231,6 @@ func (pm *profileMerger) mapLocation(src *Location) *Location {
 	}
 
 	if l, ok := pm.locationsByID[src.ID]; ok {
-		pm.locationsByID[src.ID] = l
 		return l
 	}
 
diff --git a/src/cmd/vendor/golang.org/x/mod/modfile/read.go b/src/cmd/vendor/golang.org/x/mod/modfile/read.go
index 2a961ca81c2..956f30cbb39 100644
--- a/src/cmd/vendor/golang.org/x/mod/modfile/read.go
+++ b/src/cmd/vendor/golang.org/x/mod/modfile/read.go
@@ -194,12 +194,15 @@ func (x *FileSyntax) updateLine(line *Line, tokens ...string) {
 	line.Token = tokens
 }
 
-func (x *FileSyntax) removeLine(line *Line) {
+// markRemoved modifies line so that it (and its end-of-line comment, if any)
+// will be dropped by (*FileSyntax).Cleanup.
+func (line *Line) markRemoved() {
 	line.Token = nil
+	line.Comments.Suffix = nil
 }
 
 // Cleanup cleans up the file syntax x after any edit operations.
-// To avoid quadratic behavior, removeLine marks the line as dead
+// To avoid quadratic behavior, (*Line).markRemoved marks the line as dead
 // by setting line.Token = nil but does not remove it from the slice
 // in which it appears. After edits have all been indicated,
 // calling Cleanup cleans out the dead lines.
diff --git a/src/cmd/vendor/golang.org/x/mod/modfile/rule.go b/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
index d8242de2806..78f83fa7144 100644
--- a/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
+++ b/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
@@ -58,13 +58,6 @@ type Go struct {
 	Syntax  *Line
 }
 
-// A Require is a single require statement.
-type Require struct {
-	Mod      module.Version
-	Indirect bool // has "// indirect" comment
-	Syntax   *Line
-}
-
 // An Exclude is a single exclude statement.
 type Exclude struct {
 	Mod    module.Version
@@ -93,6 +86,93 @@ type VersionInterval struct {
 	Low, High string
 }
 
+// A Require is a single require statement.
+type Require struct {
+	Mod      module.Version
+	Indirect bool // has "// indirect" comment
+	Syntax   *Line
+}
+
+func (r *Require) markRemoved() {
+	r.Syntax.markRemoved()
+	*r = Require{}
+}
+
+func (r *Require) setVersion(v string) {
+	r.Mod.Version = v
+
+	if line := r.Syntax; len(line.Token) > 0 {
+		if line.InBlock {
+			// If the line is preceded by an empty line, remove it; see
+			// https://golang.org/issue/33779.
+			if len(line.Comments.Before) == 1 && len(line.Comments.Before[0].Token) == 0 {
+				line.Comments.Before = line.Comments.Before[:0]
+			}
+			if len(line.Token) >= 2 { // example.com v1.2.3
+				line.Token[1] = v
+			}
+		} else {
+			if len(line.Token) >= 3 { // require example.com v1.2.3
+				line.Token[2] = v
+			}
+		}
+	}
+}
+
+// setIndirect sets line to have (or not have) a "// indirect" comment.
+func (r *Require) setIndirect(indirect bool) {
+	r.Indirect = indirect
+	line := r.Syntax
+	if isIndirect(line) == indirect {
+		return
+	}
+	if indirect {
+		// Adding comment.
+		if len(line.Suffix) == 0 {
+			// New comment.
+			line.Suffix = []Comment{{Token: "// indirect", Suffix: true}}
+			return
+		}
+
+		com := &line.Suffix[0]
+		text := strings.TrimSpace(strings.TrimPrefix(com.Token, string(slashSlash)))
+		if text == "" {
+			// Empty comment.
+			com.Token = "// indirect"
+			return
+		}
+
+		// Insert at beginning of existing comment.
+		com.Token = "// indirect; " + text
+		return
+	}
+
+	// Removing comment.
+	f := strings.TrimSpace(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
+	if f == "indirect" {
+		// Remove whole comment.
+		line.Suffix = nil
+		return
+	}
+
+	// Remove comment prefix.
+	com := &line.Suffix[0]
+	i := strings.Index(com.Token, "indirect;")
+	com.Token = "//" + com.Token[i+len("indirect;"):]
+}
+
+// isIndirect reports whether line has a "// indirect" comment,
+// meaning it is in go.mod only for its effect on indirect dependencies,
+// so that it can be dropped entirely once the effective version of the
+// indirect dependency reaches the given minimum version.
+func isIndirect(line *Line) bool {
+	if len(line.Suffix) == 0 {
+		return false
+	}
+	f := strings.Fields(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
+	return (len(f) == 1 && f[0] == "indirect" || len(f) > 1 && f[0] == "indirect;")
+}
+
 func (f *File) AddModuleStmt(path string) error {
 	if f.Syntax == nil {
 		f.Syntax = new(FileSyntax)
@@ -217,6 +297,7 @@ func parseToFile(file string, data []byte, fix VersionFixer, strict bool) (parse
 }
 
 var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)$`)
+var laxGoVersionRE = lazyregexp.New(`^v?(([1-9][0-9]*)\.(0|[1-9][0-9]*))([^0-9].*)$`)
 
 func (f *File) add(errs *ErrorList, block *LineBlock, line *Line, verb string, args []string, fix VersionFixer, strict bool) {
 	// If strict is false, this module is a dependency.
@@ -267,8 +348,17 @@ func (f *File) add(errs *ErrorList, block *LineBlock, line *Line, verb string, a
 			errorf("go directive expects exactly one argument")
 			return
 		} else if !GoVersionRE.MatchString(args[0]) {
-			errorf("invalid go version '%s': must match format 1.23", args[0])
-			return
+			fixed := false
+			if !strict {
+				if m := laxGoVersionRE.FindStringSubmatch(args[0]); m != nil {
+					args[0] = m[1]
+					fixed = true
+				}
+			}
+			if !fixed {
+				errorf("invalid go version '%s': must match format 1.23", args[0])
+				return
+			}
 		}
 
 		f.Go = &Go{Syntax: line}
@@ -466,58 +556,6 @@ func (f *File) fixRetract(fix VersionFixer, errs *ErrorList) {
 	}
 }
 
-// isIndirect reports whether line has a "// indirect" comment,
-// meaning it is in go.mod only for its effect on indirect dependencies,
-// so that it can be dropped entirely once the effective version of the
-// indirect dependency reaches the given minimum version.
-func isIndirect(line *Line) bool {
-	if len(line.Suffix) == 0 {
-		return false
-	}
-	f := strings.Fields(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
-	return (len(f) == 1 && f[0] == "indirect" || len(f) > 1 && f[0] == "indirect;")
-}
-
-// setIndirect sets line to have (or not have) a "// indirect" comment.
-func setIndirect(line *Line, indirect bool) {
-	if isIndirect(line) == indirect {
-		return
-	}
-	if indirect {
-		// Adding comment.
-		if len(line.Suffix) == 0 {
-			// New comment.
-			line.Suffix = []Comment{{Token: "// indirect", Suffix: true}}
-			return
-		}
-
-		com := &line.Suffix[0]
-		text := strings.TrimSpace(strings.TrimPrefix(com.Token, string(slashSlash)))
-		if text == "" {
-			// Empty comment.
-			com.Token = "// indirect"
-			return
-		}
-
-		// Insert at beginning of existing comment.
-		com.Token = "// indirect; " + text
-		return
-	}
-
-	// Removing comment.
-	f := strings.TrimSpace(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
-	if f == "indirect" {
-		// Remove whole comment.
-		line.Suffix = nil
-		return
-	}
-
-	// Remove comment prefix.
-	com := &line.Suffix[0]
-	i := strings.Index(com.Token, "indirect;")
-	com.Token = "//" + com.Token[i+len("indirect;"):]
-}
-
 // IsDirectoryPath reports whether the given path should be interpreted
 // as a directory path. Just like on the go command line, relative paths
 // and rooted paths are directory paths; the rest are module paths.
@@ -825,6 +863,12 @@ func (f *File) AddGoStmt(version string) error {
 	return nil
 }
 
+// AddRequire sets the first require line for path to version vers,
+// preserving any existing comments for that line and removing all
+// other lines for path.
+//
+// If no line currently exists for path, AddRequire adds a new line
+// at the end of the last require block.
 func (f *File) AddRequire(path, vers string) error {
 	need := true
 	for _, r := range f.Require {
@@ -834,7 +878,7 @@ func (f *File) AddRequire(path, vers string) error {
 				f.Syntax.updateLine(r.Syntax, "require", AutoQuote(path), vers)
 				need = false
 			} else {
-				f.Syntax.removeLine(r.Syntax)
+				r.Syntax.markRemoved()
 				*r = Require{}
 			}
 		}
@@ -846,69 +890,235 @@ func (f *File) AddRequire(path, vers string) error {
 	return nil
 }
 
+// AddNewRequire adds a new require line for path at version vers at the end of
+// the last require block, regardless of any existing require lines for path.
 func (f *File) AddNewRequire(path, vers string, indirect bool) {
 	line := f.Syntax.addLine(nil, "require", AutoQuote(path), vers)
-	setIndirect(line, indirect)
-	f.Require = append(f.Require, &Require{module.Version{Path: path, Version: vers}, indirect, line})
+	r := &Require{
+		Mod:    module.Version{Path: path, Version: vers},
+		Syntax: line,
+	}
+	r.setIndirect(indirect)
+	f.Require = append(f.Require, r)
 }
 
+// SetRequire updates the requirements of f to contain exactly req, preserving
+// the existing block structure and line comment contents (except for 'indirect'
+// markings) for the first requirement on each named module path.
+//
+// The Syntax field is ignored for the requirements in req.
+//
+// Any requirements not already present in the file are added to the block
+// containing the last require line.
+//
+// The requirements in req must specify at most one distinct version for each
+// module path.
+//
+// If any existing requirements may be removed, the caller should call Cleanup
+// after all edits are complete.
 func (f *File) SetRequire(req []*Require) {
-	need := make(map[string]string)
-	indirect := make(map[string]bool)
+	type elem struct {
+		version  string
+		indirect bool
+	}
+	need := make(map[string]elem)
 	for _, r := range req {
-		need[r.Mod.Path] = r.Mod.Version
-		indirect[r.Mod.Path] = r.Indirect
-	}
-
-	for _, r := range f.Require {
-		if v, ok := need[r.Mod.Path]; ok {
-			r.Mod.Version = v
-			r.Indirect = indirect[r.Mod.Path]
-		} else {
-			*r = Require{}
+		if prev, dup := need[r.Mod.Path]; dup && prev.version != r.Mod.Version {
+			panic(fmt.Errorf("SetRequire called with conflicting versions for path %s (%s and %s)", r.Mod.Path, prev.version, r.Mod.Version))
 		}
+		need[r.Mod.Path] = elem{r.Mod.Version, r.Indirect}
 	}
 
-	var newStmts []Expr
+	// Update or delete the existing Require entries to preserve
+	// only the first for each module path in req.
+	for _, r := range f.Require {
+		e, ok := need[r.Mod.Path]
+		if ok {
+			r.setVersion(e.version)
+			r.setIndirect(e.indirect)
+		} else {
+			r.markRemoved()
+		}
+		delete(need, r.Mod.Path)
+	}
+
+	// Add new entries in the last block of the file for any paths that weren't
+	// already present.
+	//
+	// This step is nondeterministic, but the final result will be deterministic
+	// because we will sort the block.
+	for path, e := range need {
+		f.AddNewRequire(path, e.version, e.indirect)
+	}
+
+	f.SortBlocks()
+}
+
+// SetRequireSeparateIndirect updates the requirements of f to contain the given
+// requirements. Comment contents (except for 'indirect' markings) are retained
+// from the first existing requirement for each module path, and block structure
+// is maintained as long as the indirect markings match.
+//
+// Any requirements on paths not already present in the file are added. Direct
+// requirements are added to the last block containing *any* other direct
+// requirement. Indirect requirements are added to the last block containing
+// *only* other indirect requirements. If no suitable block exists, a new one is
+// added, with the last block containing a direct dependency (if any)
+// immediately before the first block containing only indirect dependencies.
+//
+// The Syntax field is ignored for requirements in the given blocks.
+func (f *File) SetRequireSeparateIndirect(req []*Require) {
+	type modKey struct {
+		path     string
+		indirect bool
+	}
+	need := make(map[modKey]string)
+	for _, r := range req {
+		need[modKey{r.Mod.Path, r.Indirect}] = r.Mod.Version
+	}
+
+	comments := make(map[string]Comments)
+	for _, r := range f.Require {
+		v, ok := need[modKey{r.Mod.Path, r.Indirect}]
+		if !ok {
+			if _, ok := need[modKey{r.Mod.Path, !r.Indirect}]; ok {
+				if _, dup := comments[r.Mod.Path]; !dup {
+					comments[r.Mod.Path] = r.Syntax.Comments
+				}
+			}
+			r.markRemoved()
+			continue
+		}
+		r.setVersion(v)
+		delete(need, modKey{r.Mod.Path, r.Indirect})
+	}
+
+	var (
+		lastDirectOrMixedBlock Expr
+		firstIndirectOnlyBlock Expr
+		lastIndirectOnlyBlock  Expr
+	)
 	for _, stmt := range f.Syntax.Stmt {
 		switch stmt := stmt.(type) {
-		case *LineBlock:
-			if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
-				var newLines []*Line
-				for _, line := range stmt.Line {
-					if p, err := parseString(&line.Token[0]); err == nil && need[p] != "" {
-						if len(line.Comments.Before) == 1 && len(line.Comments.Before[0].Token) == 0 {
-							line.Comments.Before = line.Comments.Before[:0]
-						}
-						line.Token[1] = need[p]
-						delete(need, p)
-						setIndirect(line, indirect[p])
-						newLines = append(newLines, line)
-					}
-				}
-				if len(newLines) == 0 {
-					continue // drop stmt
-				}
-				stmt.Line = newLines
-			}
-
 		case *Line:
-			if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
-				if p, err := parseString(&stmt.Token[1]); err == nil && need[p] != "" {
-					stmt.Token[2] = need[p]
-					delete(need, p)
-					setIndirect(stmt, indirect[p])
-				} else {
-					continue // drop stmt
+			if len(stmt.Token) == 0 || stmt.Token[0] != "require" {
+				continue
+			}
+			if isIndirect(stmt) {
+				lastIndirectOnlyBlock = stmt
+			} else {
+				lastDirectOrMixedBlock = stmt
+			}
+		case *LineBlock:
+			if len(stmt.Token) == 0 || stmt.Token[0] != "require" {
+				continue
+			}
+			indirectOnly := true
+			for _, line := range stmt.Line {
+				if len(line.Token) == 0 {
+					continue
+				}
+				if !isIndirect(line) {
+					indirectOnly = false
+					break
+				}
+			}
+			if indirectOnly {
+				lastIndirectOnlyBlock = stmt
+				if firstIndirectOnlyBlock == nil {
+					firstIndirectOnlyBlock = stmt
+				}
+			} else {
+				lastDirectOrMixedBlock = stmt
+			}
+		}
+	}
+
+	isOrContainsStmt := func(stmt Expr, target Expr) bool {
+		if stmt == target {
+			return true
+		}
+		if stmt, ok := stmt.(*LineBlock); ok {
+			if target, ok := target.(*Line); ok {
+				for _, line := range stmt.Line {
+					if line == target {
+						return true
+					}
 				}
 			}
 		}
-		newStmts = append(newStmts, stmt)
+		return false
 	}
-	f.Syntax.Stmt = newStmts
 
-	for path, vers := range need {
-		f.AddNewRequire(path, vers, indirect[path])
+	addRequire := func(path, vers string, indirect bool, comments Comments) {
+		var line *Line
+		if indirect {
+			if lastIndirectOnlyBlock != nil {
+				line = f.Syntax.addLine(lastIndirectOnlyBlock, "require", path, vers)
+			} else {
+				// Add a new require block after the last direct-only or mixed "require"
+				// block (if any).
+				//
+				// (f.Syntax.addLine would add the line to an existing "require" block if
+				// present, but here the existing "require" blocks are all direct-only, so
+				// we know we need to add a new block instead.)
+				line = &Line{Token: []string{"require", path, vers}}
+				lastIndirectOnlyBlock = line
+				firstIndirectOnlyBlock = line // only block implies first block
+				if lastDirectOrMixedBlock == nil {
+					f.Syntax.Stmt = append(f.Syntax.Stmt, line)
+				} else {
+					for i, stmt := range f.Syntax.Stmt {
+						if isOrContainsStmt(stmt, lastDirectOrMixedBlock) {
+							f.Syntax.Stmt = append(f.Syntax.Stmt, nil)     // increase size
+							copy(f.Syntax.Stmt[i+2:], f.Syntax.Stmt[i+1:]) // shuffle elements up
+							f.Syntax.Stmt[i+1] = line
+							break
+						}
+					}
+				}
+			}
+		} else {
+			if lastDirectOrMixedBlock != nil {
+				line = f.Syntax.addLine(lastDirectOrMixedBlock, "require", path, vers)
+			} else {
+				// Add a new require block before the first indirect block (if any).
+				//
+				// That way if the file initially contains only indirect lines,
+				// the direct lines still appear before it: we preserve existing
+				// structure, but only to the extent that that structure already
+				// reflects the direct/indirect split.
+				line = &Line{Token: []string{"require", path, vers}}
+				lastDirectOrMixedBlock = line
+				if firstIndirectOnlyBlock == nil {
+					f.Syntax.Stmt = append(f.Syntax.Stmt, line)
+				} else {
+					for i, stmt := range f.Syntax.Stmt {
+						if isOrContainsStmt(stmt, firstIndirectOnlyBlock) {
+							f.Syntax.Stmt = append(f.Syntax.Stmt, nil)   // increase size
+							copy(f.Syntax.Stmt[i+1:], f.Syntax.Stmt[i:]) // shuffle elements up
+							f.Syntax.Stmt[i] = line
+							break
+						}
+					}
+				}
+			}
+		}
+
+		line.Comments.Before = commentsAdd(line.Comments.Before, comments.Before)
+		line.Comments.Suffix = commentsAdd(line.Comments.Suffix, comments.Suffix)
+
+		r := &Require{
+			Mod:      module.Version{Path: path, Version: vers},
+			Indirect: indirect,
+			Syntax:   line,
+		}
+		r.setIndirect(indirect)
+		f.Require = append(f.Require, r)
+	}
+
+	for k, vers := range need {
+		addRequire(k.path, vers, k.indirect, comments[k.path])
 	}
 	f.SortBlocks()
 }
@@ -916,7 +1126,7 @@ func (f *File) SetRequire(req []*Require) {
 func (f *File) DropRequire(path string) error {
 	for _, r := range f.Require {
 		if r.Mod.Path == path {
-			f.Syntax.removeLine(r.Syntax)
+			r.Syntax.markRemoved()
 			*r = Require{}
 		}
 	}
@@ -947,7 +1157,7 @@ func (f *File) AddExclude(path, vers string) error {
 func (f *File) DropExclude(path, vers string) error {
 	for _, x := range f.Exclude {
 		if x.Mod.Path == path && x.Mod.Version == vers {
-			f.Syntax.removeLine(x.Syntax)
+			x.Syntax.markRemoved()
 			*x = Exclude{}
 		}
 	}
@@ -978,7 +1188,7 @@ func (f *File) AddReplace(oldPath, oldVers, newPath, newVers string) error {
 				continue
 			}
 			// Already added; delete other replacements for same.
-			f.Syntax.removeLine(r.Syntax)
+			r.Syntax.markRemoved()
 			*r = Replace{}
 		}
 		if r.Old.Path == oldPath {
@@ -994,7 +1204,7 @@ func (f *File) AddReplace(oldPath, oldVers, newPath, newVers string) error {
 func (f *File) DropReplace(oldPath, oldVers string) error {
 	for _, r := range f.Replace {
 		if r.Old.Path == oldPath && r.Old.Version == oldVers {
-			f.Syntax.removeLine(r.Syntax)
+			r.Syntax.markRemoved()
 			*r = Replace{}
 		}
 	}
@@ -1035,7 +1245,7 @@ func (f *File) AddRetract(vi VersionInterval, rationale string) error {
 func (f *File) DropRetract(vi VersionInterval) error {
 	for _, r := range f.Retract {
 		if r.VersionInterval == vi {
-			f.Syntax.removeLine(r.Syntax)
+			r.Syntax.markRemoved()
 			*r = Retract{}
 		}
 	}
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/mkall.sh b/src/cmd/vendor/golang.org/x/sys/unix/mkall.sh
index d727cad19c1..396aadf86de 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/mkall.sh
+++ b/src/cmd/vendor/golang.org/x/sys/unix/mkall.sh
@@ -70,23 +70,11 @@ aix_ppc64)
 	mksyscall="go run mksyscall_aix_ppc64.go -aix"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
-darwin_386)
-	mkerrors="$mkerrors -m32"
-	mksyscall="go run mksyscall.go -l32"
-	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
-	mkasm="go run mkasm_darwin.go"
-	;;
 darwin_amd64)
 	mkerrors="$mkerrors -m64"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	mkasm="go run mkasm_darwin.go"
 	;;
-darwin_arm)
-	mkerrors="$mkerrors"
-	mksyscall="go run mksyscall.go -l32"
-	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
-	mkasm="go run mkasm_darwin.go"
-	;;
 darwin_arm64)
 	mkerrors="$mkerrors -m64"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
index 5fc3cda6fc8..1596426b1e2 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
@@ -17,7 +17,7 @@ import (
 //sys	readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno)
 
 func fdopendir(fd int) (dir uintptr, err error) {
-	r0, _, e1 := syscall_syscallPtr(funcPC(libc_fdopendir_trampoline), uintptr(fd), 0, 0)
+	r0, _, e1 := syscall_syscallPtr(libc_fdopendir_trampoline_addr, uintptr(fd), 0, 0)
 	dir = uintptr(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -25,7 +25,7 @@ func fdopendir(fd int) (dir uintptr, err error) {
 	return
 }
 
-func libc_fdopendir_trampoline()
+var libc_fdopendir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fdopendir fdopendir "/usr/lib/libSystem.B.dylib"
 
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_386.go b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_386.go
deleted file mode 100644
index 64746771226..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_386.go
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build 386 && darwin
-// +build 386,darwin
-
-package unix
-
-import "syscall"
-
-func setTimespec(sec, nsec int64) Timespec {
-	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
-}
-
-func setTimeval(sec, usec int64) Timeval {
-	return Timeval{Sec: int32(sec), Usec: int32(usec)}
-}
-
-func SetKevent(k *Kevent_t, fd, mode, flags int) {
-	k.Ident = uint32(fd)
-	k.Filter = int16(mode)
-	k.Flags = uint16(flags)
-}
-
-func (iov *Iovec) SetLen(length int) {
-	iov.Len = uint32(length)
-}
-
-func (msghdr *Msghdr) SetControllen(length int) {
-	msghdr.Controllen = uint32(length)
-}
-
-func (msghdr *Msghdr) SetIovlen(length int) {
-	msghdr.Iovlen = int32(length)
-}
-
-func (cmsg *Cmsghdr) SetLen(length int) {
-	cmsg.Len = uint32(length)
-}
-
-func Syscall9(num, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)
-
-//sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
-//sys	Fstatat(fd int, path string, stat *Stat_t, flags int) (err error) = SYS_FSTATAT64
-//sys	Fstatfs(fd int, stat *Statfs_t) (err error) = SYS_FSTATFS64
-//sys	getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) = SYS_GETFSSTAT64
-//sys	Lstat(path string, stat *Stat_t) (err error) = SYS_LSTAT64
-//sys	ptrace1(request int, pid int, addr uintptr, data uintptr) (err error) = SYS_ptrace
-//sys	Stat(path string, stat *Stat_t) (err error) = SYS_STAT64
-//sys	Statfs(path string, stat *Statfs_t) (err error) = SYS_STATFS64
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_arm.go b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_arm.go
deleted file mode 100644
index d30735c5d63..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_arm.go
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package unix
-
-import "syscall"
-
-func ptrace1(request int, pid int, addr uintptr, data uintptr) error {
-	return ENOTSUP
-}
-
-func setTimespec(sec, nsec int64) Timespec {
-	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
-}
-
-func setTimeval(sec, usec int64) Timeval {
-	return Timeval{Sec: int32(sec), Usec: int32(usec)}
-}
-
-func SetKevent(k *Kevent_t, fd, mode, flags int) {
-	k.Ident = uint32(fd)
-	k.Filter = int16(mode)
-	k.Flags = uint16(flags)
-}
-
-func (iov *Iovec) SetLen(length int) {
-	iov.Len = uint32(length)
-}
-
-func (msghdr *Msghdr) SetControllen(length int) {
-	msghdr.Controllen = uint32(length)
-}
-
-func (msghdr *Msghdr) SetIovlen(length int) {
-	msghdr.Iovlen = int32(length)
-}
-
-func (cmsg *Cmsghdr) SetLen(length int) {
-	cmsg.Len = uint32(length)
-}
-
-func Syscall9(num, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno) // sic
-
-//sys	Fstat(fd int, stat *Stat_t) (err error)
-//sys	Fstatat(fd int, path string, stat *Stat_t, flags int) (err error)
-//sys	Fstatfs(fd int, stat *Statfs_t) (err error)
-//sys	getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) = SYS_GETFSSTAT
-//sys	Lstat(path string, stat *Stat_t) (err error)
-//sys	Stat(path string, stat *Stat_t) (err error)
-//sys	Statfs(path string, stat *Statfs_t) (err error)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
index 38bec300262..53c96641f81 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
@@ -7,7 +7,7 @@
 
 package unix
 
-import "unsafe"
+import _ "unsafe"
 
 // Implemented in the runtime package (runtime/sys_darwin.go)
 func syscall_syscall(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
@@ -25,10 +25,3 @@ func syscall_syscallPtr(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 //go:linkname syscall_rawSyscall syscall.rawSyscall
 //go:linkname syscall_rawSyscall6 syscall.rawSyscall6
 //go:linkname syscall_syscallPtr syscall.syscallPtr
-
-// Find the entry point for f. See comments in runtime/proc.go for the
-// function of the same name.
-//go:nosplit
-func funcPC(f func()) uintptr {
-	return **(**uintptr)(unsafe.Pointer(&f))
-}
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_386.go b/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_386.go
deleted file mode 100644
index 7ee196f7fcc..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_386.go
+++ /dev/null
@@ -1,1789 +0,0 @@
-// mkerrors.sh -m32
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build 386 && darwin
-// +build 386,darwin
-
-// Code generated by cmd/cgo -godefs; DO NOT EDIT.
-// cgo -godefs -- -m32 _const.go
-
-package unix
-
-import "syscall"
-
-const (
-	AF_APPLETALK                      = 0x10
-	AF_CCITT                          = 0xa
-	AF_CHAOS                          = 0x5
-	AF_CNT                            = 0x15
-	AF_COIP                           = 0x14
-	AF_DATAKIT                        = 0x9
-	AF_DECnet                         = 0xc
-	AF_DLI                            = 0xd
-	AF_E164                           = 0x1c
-	AF_ECMA                           = 0x8
-	AF_HYLINK                         = 0xf
-	AF_IEEE80211                      = 0x25
-	AF_IMPLINK                        = 0x3
-	AF_INET                           = 0x2
-	AF_INET6                          = 0x1e
-	AF_IPX                            = 0x17
-	AF_ISDN                           = 0x1c
-	AF_ISO                            = 0x7
-	AF_LAT                            = 0xe
-	AF_LINK                           = 0x12
-	AF_LOCAL                          = 0x1
-	AF_MAX                            = 0x28
-	AF_NATM                           = 0x1f
-	AF_NDRV                           = 0x1b
-	AF_NETBIOS                        = 0x21
-	AF_NS                             = 0x6
-	AF_OSI                            = 0x7
-	AF_PPP                            = 0x22
-	AF_PUP                            = 0x4
-	AF_RESERVED_36                    = 0x24
-	AF_ROUTE                          = 0x11
-	AF_SIP                            = 0x18
-	AF_SNA                            = 0xb
-	AF_SYSTEM                         = 0x20
-	AF_SYS_CONTROL                    = 0x2
-	AF_UNIX                           = 0x1
-	AF_UNSPEC                         = 0x0
-	AF_UTUN                           = 0x26
-	ALTWERASE                         = 0x200
-	ATTR_BIT_MAP_COUNT                = 0x5
-	ATTR_CMN_ACCESSMASK               = 0x20000
-	ATTR_CMN_ACCTIME                  = 0x1000
-	ATTR_CMN_ADDEDTIME                = 0x10000000
-	ATTR_CMN_BKUPTIME                 = 0x2000
-	ATTR_CMN_CHGTIME                  = 0x800
-	ATTR_CMN_CRTIME                   = 0x200
-	ATTR_CMN_DATA_PROTECT_FLAGS       = 0x40000000
-	ATTR_CMN_DEVID                    = 0x2
-	ATTR_CMN_DOCUMENT_ID              = 0x100000
-	ATTR_CMN_ERROR                    = 0x20000000
-	ATTR_CMN_EXTENDED_SECURITY        = 0x400000
-	ATTR_CMN_FILEID                   = 0x2000000
-	ATTR_CMN_FLAGS                    = 0x40000
-	ATTR_CMN_FNDRINFO                 = 0x4000
-	ATTR_CMN_FSID                     = 0x4
-	ATTR_CMN_FULLPATH                 = 0x8000000
-	ATTR_CMN_GEN_COUNT                = 0x80000
-	ATTR_CMN_GRPID                    = 0x10000
-	ATTR_CMN_GRPUUID                  = 0x1000000
-	ATTR_CMN_MODTIME                  = 0x400
-	ATTR_CMN_NAME                     = 0x1
-	ATTR_CMN_NAMEDATTRCOUNT           = 0x80000
-	ATTR_CMN_NAMEDATTRLIST            = 0x100000
-	ATTR_CMN_OBJID                    = 0x20
-	ATTR_CMN_OBJPERMANENTID           = 0x40
-	ATTR_CMN_OBJTAG                   = 0x10
-	ATTR_CMN_OBJTYPE                  = 0x8
-	ATTR_CMN_OWNERID                  = 0x8000
-	ATTR_CMN_PARENTID                 = 0x4000000
-	ATTR_CMN_PAROBJID                 = 0x80
-	ATTR_CMN_RETURNED_ATTRS           = 0x80000000
-	ATTR_CMN_SCRIPT                   = 0x100
-	ATTR_CMN_SETMASK                  = 0x41c7ff00
-	ATTR_CMN_USERACCESS               = 0x200000
-	ATTR_CMN_UUID                     = 0x800000
-	ATTR_CMN_VALIDMASK                = 0xffffffff
-	ATTR_CMN_VOLSETMASK               = 0x6700
-	ATTR_FILE_ALLOCSIZE               = 0x4
-	ATTR_FILE_CLUMPSIZE               = 0x10
-	ATTR_FILE_DATAALLOCSIZE           = 0x400
-	ATTR_FILE_DATAEXTENTS             = 0x800
-	ATTR_FILE_DATALENGTH              = 0x200
-	ATTR_FILE_DEVTYPE                 = 0x20
-	ATTR_FILE_FILETYPE                = 0x40
-	ATTR_FILE_FORKCOUNT               = 0x80
-	ATTR_FILE_FORKLIST                = 0x100
-	ATTR_FILE_IOBLOCKSIZE             = 0x8
-	ATTR_FILE_LINKCOUNT               = 0x1
-	ATTR_FILE_RSRCALLOCSIZE           = 0x2000
-	ATTR_FILE_RSRCEXTENTS             = 0x4000
-	ATTR_FILE_RSRCLENGTH              = 0x1000
-	ATTR_FILE_SETMASK                 = 0x20
-	ATTR_FILE_TOTALSIZE               = 0x2
-	ATTR_FILE_VALIDMASK               = 0x37ff
-	ATTR_VOL_ALLOCATIONCLUMP          = 0x40
-	ATTR_VOL_ATTRIBUTES               = 0x40000000
-	ATTR_VOL_CAPABILITIES             = 0x20000
-	ATTR_VOL_DIRCOUNT                 = 0x400
-	ATTR_VOL_ENCODINGSUSED            = 0x10000
-	ATTR_VOL_FILECOUNT                = 0x200
-	ATTR_VOL_FSTYPE                   = 0x1
-	ATTR_VOL_INFO                     = 0x80000000
-	ATTR_VOL_IOBLOCKSIZE              = 0x80
-	ATTR_VOL_MAXOBJCOUNT              = 0x800
-	ATTR_VOL_MINALLOCATION            = 0x20
-	ATTR_VOL_MOUNTEDDEVICE            = 0x8000
-	ATTR_VOL_MOUNTFLAGS               = 0x4000
-	ATTR_VOL_MOUNTPOINT               = 0x1000
-	ATTR_VOL_NAME                     = 0x2000
-	ATTR_VOL_OBJCOUNT                 = 0x100
-	ATTR_VOL_QUOTA_SIZE               = 0x10000000
-	ATTR_VOL_RESERVED_SIZE            = 0x20000000
-	ATTR_VOL_SETMASK                  = 0x80002000
-	ATTR_VOL_SIGNATURE                = 0x2
-	ATTR_VOL_SIZE                     = 0x4
-	ATTR_VOL_SPACEAVAIL               = 0x10
-	ATTR_VOL_SPACEFREE                = 0x8
-	ATTR_VOL_UUID                     = 0x40000
-	ATTR_VOL_VALIDMASK                = 0xf007ffff
-	B0                                = 0x0
-	B110                              = 0x6e
-	B115200                           = 0x1c200
-	B1200                             = 0x4b0
-	B134                              = 0x86
-	B14400                            = 0x3840
-	B150                              = 0x96
-	B1800                             = 0x708
-	B19200                            = 0x4b00
-	B200                              = 0xc8
-	B230400                           = 0x38400
-	B2400                             = 0x960
-	B28800                            = 0x7080
-	B300                              = 0x12c
-	B38400                            = 0x9600
-	B4800                             = 0x12c0
-	B50                               = 0x32
-	B57600                            = 0xe100
-	B600                              = 0x258
-	B7200                             = 0x1c20
-	B75                               = 0x4b
-	B76800                            = 0x12c00
-	B9600                             = 0x2580
-	BIOCFLUSH                         = 0x20004268
-	BIOCGBLEN                         = 0x40044266
-	BIOCGDLT                          = 0x4004426a
-	BIOCGDLTLIST                      = 0xc00c4279
-	BIOCGETIF                         = 0x4020426b
-	BIOCGHDRCMPLT                     = 0x40044274
-	BIOCGRSIG                         = 0x40044272
-	BIOCGRTIMEOUT                     = 0x4008426e
-	BIOCGSEESENT                      = 0x40044276
-	BIOCGSTATS                        = 0x4008426f
-	BIOCIMMEDIATE                     = 0x80044270
-	BIOCPROMISC                       = 0x20004269
-	BIOCSBLEN                         = 0xc0044266
-	BIOCSDLT                          = 0x80044278
-	BIOCSETF                          = 0x80084267
-	BIOCSETFNR                        = 0x8008427e
-	BIOCSETIF                         = 0x8020426c
-	BIOCSHDRCMPLT                     = 0x80044275
-	BIOCSRSIG                         = 0x80044273
-	BIOCSRTIMEOUT                     = 0x8008426d
-	BIOCSSEESENT                      = 0x80044277
-	BIOCVERSION                       = 0x40044271
-	BPF_A                             = 0x10
-	BPF_ABS                           = 0x20
-	BPF_ADD                           = 0x0
-	BPF_ALIGNMENT                     = 0x4
-	BPF_ALU                           = 0x4
-	BPF_AND                           = 0x50
-	BPF_B                             = 0x10
-	BPF_DIV                           = 0x30
-	BPF_H                             = 0x8
-	BPF_IMM                           = 0x0
-	BPF_IND                           = 0x40
-	BPF_JA                            = 0x0
-	BPF_JEQ                           = 0x10
-	BPF_JGE                           = 0x30
-	BPF_JGT                           = 0x20
-	BPF_JMP                           = 0x5
-	BPF_JSET                          = 0x40
-	BPF_K                             = 0x0
-	BPF_LD                            = 0x0
-	BPF_LDX                           = 0x1
-	BPF_LEN                           = 0x80
-	BPF_LSH                           = 0x60
-	BPF_MAJOR_VERSION                 = 0x1
-	BPF_MAXBUFSIZE                    = 0x80000
-	BPF_MAXINSNS                      = 0x200
-	BPF_MEM                           = 0x60
-	BPF_MEMWORDS                      = 0x10
-	BPF_MINBUFSIZE                    = 0x20
-	BPF_MINOR_VERSION                 = 0x1
-	BPF_MISC                          = 0x7
-	BPF_MSH                           = 0xa0
-	BPF_MUL                           = 0x20
-	BPF_NEG                           = 0x80
-	BPF_OR                            = 0x40
-	BPF_RELEASE                       = 0x30bb6
-	BPF_RET                           = 0x6
-	BPF_RSH                           = 0x70
-	BPF_ST                            = 0x2
-	BPF_STX                           = 0x3
-	BPF_SUB                           = 0x10
-	BPF_TAX                           = 0x0
-	BPF_TXA                           = 0x80
-	BPF_W                             = 0x0
-	BPF_X                             = 0x8
-	BRKINT                            = 0x2
-	BS0                               = 0x0
-	BS1                               = 0x8000
-	BSDLY                             = 0x8000
-	CFLUSH                            = 0xf
-	CLOCAL                            = 0x8000
-	CLOCK_MONOTONIC                   = 0x6
-	CLOCK_MONOTONIC_RAW               = 0x4
-	CLOCK_MONOTONIC_RAW_APPROX        = 0x5
-	CLOCK_PROCESS_CPUTIME_ID          = 0xc
-	CLOCK_REALTIME                    = 0x0
-	CLOCK_THREAD_CPUTIME_ID           = 0x10
-	CLOCK_UPTIME_RAW                  = 0x8
-	CLOCK_UPTIME_RAW_APPROX           = 0x9
-	CLONE_NOFOLLOW                    = 0x1
-	CLONE_NOOWNERCOPY                 = 0x2
-	CR0                               = 0x0
-	CR1                               = 0x1000
-	CR2                               = 0x2000
-	CR3                               = 0x3000
-	CRDLY                             = 0x3000
-	CREAD                             = 0x800
-	CRTSCTS                           = 0x30000
-	CS5                               = 0x0
-	CS6                               = 0x100
-	CS7                               = 0x200
-	CS8                               = 0x300
-	CSIZE                             = 0x300
-	CSTART                            = 0x11
-	CSTATUS                           = 0x14
-	CSTOP                             = 0x13
-	CSTOPB                            = 0x400
-	CSUSP                             = 0x1a
-	CTLIOCGINFO                       = 0xc0644e03
-	CTL_HW                            = 0x6
-	CTL_KERN                          = 0x1
-	CTL_MAXNAME                       = 0xc
-	CTL_NET                           = 0x4
-	DLT_A429                          = 0xb8
-	DLT_A653_ICM                      = 0xb9
-	DLT_AIRONET_HEADER                = 0x78
-	DLT_AOS                           = 0xde
-	DLT_APPLE_IP_OVER_IEEE1394        = 0x8a
-	DLT_ARCNET                        = 0x7
-	DLT_ARCNET_LINUX                  = 0x81
-	DLT_ATM_CLIP                      = 0x13
-	DLT_ATM_RFC1483                   = 0xb
-	DLT_AURORA                        = 0x7e
-	DLT_AX25                          = 0x3
-	DLT_AX25_KISS                     = 0xca
-	DLT_BACNET_MS_TP                  = 0xa5
-	DLT_BLUETOOTH_HCI_H4              = 0xbb
-	DLT_BLUETOOTH_HCI_H4_WITH_PHDR    = 0xc9
-	DLT_CAN20B                        = 0xbe
-	DLT_CAN_SOCKETCAN                 = 0xe3
-	DLT_CHAOS                         = 0x5
-	DLT_CHDLC                         = 0x68
-	DLT_CISCO_IOS                     = 0x76
-	DLT_C_HDLC                        = 0x68
-	DLT_C_HDLC_WITH_DIR               = 0xcd
-	DLT_DBUS                          = 0xe7
-	DLT_DECT                          = 0xdd
-	DLT_DOCSIS                        = 0x8f
-	DLT_DVB_CI                        = 0xeb
-	DLT_ECONET                        = 0x73
-	DLT_EN10MB                        = 0x1
-	DLT_EN3MB                         = 0x2
-	DLT_ENC                           = 0x6d
-	DLT_ERF                           = 0xc5
-	DLT_ERF_ETH                       = 0xaf
-	DLT_ERF_POS                       = 0xb0
-	DLT_FC_2                          = 0xe0
-	DLT_FC_2_WITH_FRAME_DELIMS        = 0xe1
-	DLT_FDDI                          = 0xa
-	DLT_FLEXRAY                       = 0xd2
-	DLT_FRELAY                        = 0x6b
-	DLT_FRELAY_WITH_DIR               = 0xce
-	DLT_GCOM_SERIAL                   = 0xad
-	DLT_GCOM_T1E1                     = 0xac
-	DLT_GPF_F                         = 0xab
-	DLT_GPF_T                         = 0xaa
-	DLT_GPRS_LLC                      = 0xa9
-	DLT_GSMTAP_ABIS                   = 0xda
-	DLT_GSMTAP_UM                     = 0xd9
-	DLT_HHDLC                         = 0x79
-	DLT_IBM_SN                        = 0x92
-	DLT_IBM_SP                        = 0x91
-	DLT_IEEE802                       = 0x6
-	DLT_IEEE802_11                    = 0x69
-	DLT_IEEE802_11_RADIO              = 0x7f
-	DLT_IEEE802_11_RADIO_AVS          = 0xa3
-	DLT_IEEE802_15_4                  = 0xc3
-	DLT_IEEE802_15_4_LINUX            = 0xbf
-	DLT_IEEE802_15_4_NOFCS            = 0xe6
-	DLT_IEEE802_15_4_NONASK_PHY       = 0xd7
-	DLT_IEEE802_16_MAC_CPS            = 0xbc
-	DLT_IEEE802_16_MAC_CPS_RADIO      = 0xc1
-	DLT_IPFILTER                      = 0x74
-	DLT_IPMB                          = 0xc7
-	DLT_IPMB_LINUX                    = 0xd1
-	DLT_IPNET                         = 0xe2
-	DLT_IPOIB                         = 0xf2
-	DLT_IPV4                          = 0xe4
-	DLT_IPV6                          = 0xe5
-	DLT_IP_OVER_FC                    = 0x7a
-	DLT_JUNIPER_ATM1                  = 0x89
-	DLT_JUNIPER_ATM2                  = 0x87
-	DLT_JUNIPER_ATM_CEMIC             = 0xee
-	DLT_JUNIPER_CHDLC                 = 0xb5
-	DLT_JUNIPER_ES                    = 0x84
-	DLT_JUNIPER_ETHER                 = 0xb2
-	DLT_JUNIPER_FIBRECHANNEL          = 0xea
-	DLT_JUNIPER_FRELAY                = 0xb4
-	DLT_JUNIPER_GGSN                  = 0x85
-	DLT_JUNIPER_ISM                   = 0xc2
-	DLT_JUNIPER_MFR                   = 0x86
-	DLT_JUNIPER_MLFR                  = 0x83
-	DLT_JUNIPER_MLPPP                 = 0x82
-	DLT_JUNIPER_MONITOR               = 0xa4
-	DLT_JUNIPER_PIC_PEER              = 0xae
-	DLT_JUNIPER_PPP                   = 0xb3
-	DLT_JUNIPER_PPPOE                 = 0xa7
-	DLT_JUNIPER_PPPOE_ATM             = 0xa8
-	DLT_JUNIPER_SERVICES              = 0x88
-	DLT_JUNIPER_SRX_E2E               = 0xe9
-	DLT_JUNIPER_ST                    = 0xc8
-	DLT_JUNIPER_VP                    = 0xb7
-	DLT_JUNIPER_VS                    = 0xe8
-	DLT_LAPB_WITH_DIR                 = 0xcf
-	DLT_LAPD                          = 0xcb
-	DLT_LIN                           = 0xd4
-	DLT_LINUX_EVDEV                   = 0xd8
-	DLT_LINUX_IRDA                    = 0x90
-	DLT_LINUX_LAPD                    = 0xb1
-	DLT_LINUX_PPP_WITHDIRECTION       = 0xa6
-	DLT_LINUX_SLL                     = 0x71
-	DLT_LOOP                          = 0x6c
-	DLT_LTALK                         = 0x72
-	DLT_MATCHING_MAX                  = 0xf5
-	DLT_MATCHING_MIN                  = 0x68
-	DLT_MFR                           = 0xb6
-	DLT_MOST                          = 0xd3
-	DLT_MPEG_2_TS                     = 0xf3
-	DLT_MPLS                          = 0xdb
-	DLT_MTP2                          = 0x8c
-	DLT_MTP2_WITH_PHDR                = 0x8b
-	DLT_MTP3                          = 0x8d
-	DLT_MUX27010                      = 0xec
-	DLT_NETANALYZER                   = 0xf0
-	DLT_NETANALYZER_TRANSPARENT       = 0xf1
-	DLT_NFC_LLCP                      = 0xf5
-	DLT_NFLOG                         = 0xef
-	DLT_NG40                          = 0xf4
-	DLT_NULL                          = 0x0
-	DLT_PCI_EXP                       = 0x7d
-	DLT_PFLOG                         = 0x75
-	DLT_PFSYNC                        = 0x12
-	DLT_PPI                           = 0xc0
-	DLT_PPP                           = 0x9
-	DLT_PPP_BSDOS                     = 0x10
-	DLT_PPP_ETHER                     = 0x33
-	DLT_PPP_PPPD                      = 0xa6
-	DLT_PPP_SERIAL                    = 0x32
-	DLT_PPP_WITH_DIR                  = 0xcc
-	DLT_PPP_WITH_DIRECTION            = 0xa6
-	DLT_PRISM_HEADER                  = 0x77
-	DLT_PRONET                        = 0x4
-	DLT_RAIF1                         = 0xc6
-	DLT_RAW                           = 0xc
-	DLT_RIO                           = 0x7c
-	DLT_SCCP                          = 0x8e
-	DLT_SITA                          = 0xc4
-	DLT_SLIP                          = 0x8
-	DLT_SLIP_BSDOS                    = 0xf
-	DLT_STANAG_5066_D_PDU             = 0xed
-	DLT_SUNATM                        = 0x7b
-	DLT_SYMANTEC_FIREWALL             = 0x63
-	DLT_TZSP                          = 0x80
-	DLT_USB                           = 0xba
-	DLT_USB_LINUX                     = 0xbd
-	DLT_USB_LINUX_MMAPPED             = 0xdc
-	DLT_USER0                         = 0x93
-	DLT_USER1                         = 0x94
-	DLT_USER10                        = 0x9d
-	DLT_USER11                        = 0x9e
-	DLT_USER12                        = 0x9f
-	DLT_USER13                        = 0xa0
-	DLT_USER14                        = 0xa1
-	DLT_USER15                        = 0xa2
-	DLT_USER2                         = 0x95
-	DLT_USER3                         = 0x96
-	DLT_USER4                         = 0x97
-	DLT_USER5                         = 0x98
-	DLT_USER6                         = 0x99
-	DLT_USER7                         = 0x9a
-	DLT_USER8                         = 0x9b
-	DLT_USER9                         = 0x9c
-	DLT_WIHART                        = 0xdf
-	DLT_X2E_SERIAL                    = 0xd5
-	DLT_X2E_XORAYA                    = 0xd6
-	DT_BLK                            = 0x6
-	DT_CHR                            = 0x2
-	DT_DIR                            = 0x4
-	DT_FIFO                           = 0x1
-	DT_LNK                            = 0xa
-	DT_REG                            = 0x8
-	DT_SOCK                           = 0xc
-	DT_UNKNOWN                        = 0x0
-	DT_WHT                            = 0xe
-	ECHO                              = 0x8
-	ECHOCTL                           = 0x40
-	ECHOE                             = 0x2
-	ECHOK                             = 0x4
-	ECHOKE                            = 0x1
-	ECHONL                            = 0x10
-	ECHOPRT                           = 0x20
-	EVFILT_AIO                        = -0x3
-	EVFILT_EXCEPT                     = -0xf
-	EVFILT_FS                         = -0x9
-	EVFILT_MACHPORT                   = -0x8
-	EVFILT_PROC                       = -0x5
-	EVFILT_READ                       = -0x1
-	EVFILT_SIGNAL                     = -0x6
-	EVFILT_SYSCOUNT                   = 0xf
-	EVFILT_THREADMARKER               = 0xf
-	EVFILT_TIMER                      = -0x7
-	EVFILT_USER                       = -0xa
-	EVFILT_VM                         = -0xc
-	EVFILT_VNODE                      = -0x4
-	EVFILT_WRITE                      = -0x2
-	EV_ADD                            = 0x1
-	EV_CLEAR                          = 0x20
-	EV_DELETE                         = 0x2
-	EV_DISABLE                        = 0x8
-	EV_DISPATCH                       = 0x80
-	EV_DISPATCH2                      = 0x180
-	EV_ENABLE                         = 0x4
-	EV_EOF                            = 0x8000
-	EV_ERROR                          = 0x4000
-	EV_FLAG0                          = 0x1000
-	EV_FLAG1                          = 0x2000
-	EV_ONESHOT                        = 0x10
-	EV_OOBAND                         = 0x2000
-	EV_POLL                           = 0x1000
-	EV_RECEIPT                        = 0x40
-	EV_SYSFLAGS                       = 0xf000
-	EV_UDATA_SPECIFIC                 = 0x100
-	EV_VANISHED                       = 0x200
-	EXTA                              = 0x4b00
-	EXTB                              = 0x9600
-	EXTPROC                           = 0x800
-	FD_CLOEXEC                        = 0x1
-	FD_SETSIZE                        = 0x400
-	FF0                               = 0x0
-	FF1                               = 0x4000
-	FFDLY                             = 0x4000
-	FLUSHO                            = 0x800000
-	FSOPT_ATTR_CMN_EXTENDED           = 0x20
-	FSOPT_NOFOLLOW                    = 0x1
-	FSOPT_NOINMEMUPDATE               = 0x2
-	FSOPT_PACK_INVAL_ATTRS            = 0x8
-	FSOPT_REPORT_FULLSIZE             = 0x4
-	F_ADDFILESIGS                     = 0x3d
-	F_ADDFILESIGS_FOR_DYLD_SIM        = 0x53
-	F_ADDFILESIGS_RETURN              = 0x61
-	F_ADDSIGS                         = 0x3b
-	F_ALLOCATEALL                     = 0x4
-	F_ALLOCATECONTIG                  = 0x2
-	F_BARRIERFSYNC                    = 0x55
-	F_CHECK_LV                        = 0x62
-	F_CHKCLEAN                        = 0x29
-	F_DUPFD                           = 0x0
-	F_DUPFD_CLOEXEC                   = 0x43
-	F_FINDSIGS                        = 0x4e
-	F_FLUSH_DATA                      = 0x28
-	F_FREEZE_FS                       = 0x35
-	F_FULLFSYNC                       = 0x33
-	F_GETCODEDIR                      = 0x48
-	F_GETFD                           = 0x1
-	F_GETFL                           = 0x3
-	F_GETLK                           = 0x7
-	F_GETLKPID                        = 0x42
-	F_GETNOSIGPIPE                    = 0x4a
-	F_GETOWN                          = 0x5
-	F_GETPATH                         = 0x32
-	F_GETPATH_MTMINFO                 = 0x47
-	F_GETPROTECTIONCLASS              = 0x3f
-	F_GETPROTECTIONLEVEL              = 0x4d
-	F_GLOBAL_NOCACHE                  = 0x37
-	F_LOG2PHYS                        = 0x31
-	F_LOG2PHYS_EXT                    = 0x41
-	F_NOCACHE                         = 0x30
-	F_NODIRECT                        = 0x3e
-	F_OK                              = 0x0
-	F_PATHPKG_CHECK                   = 0x34
-	F_PEOFPOSMODE                     = 0x3
-	F_PREALLOCATE                     = 0x2a
-	F_PUNCHHOLE                       = 0x63
-	F_RDADVISE                        = 0x2c
-	F_RDAHEAD                         = 0x2d
-	F_RDLCK                           = 0x1
-	F_SETBACKINGSTORE                 = 0x46
-	F_SETFD                           = 0x2
-	F_SETFL                           = 0x4
-	F_SETLK                           = 0x8
-	F_SETLKW                          = 0x9
-	F_SETLKWTIMEOUT                   = 0xa
-	F_SETNOSIGPIPE                    = 0x49
-	F_SETOWN                          = 0x6
-	F_SETPROTECTIONCLASS              = 0x40
-	F_SETSIZE                         = 0x2b
-	F_SINGLE_WRITER                   = 0x4c
-	F_THAW_FS                         = 0x36
-	F_TRANSCODEKEY                    = 0x4b
-	F_TRIM_ACTIVE_FILE                = 0x64
-	F_UNLCK                           = 0x2
-	F_VOLPOSMODE                      = 0x4
-	F_WRLCK                           = 0x3
-	HUPCL                             = 0x4000
-	HW_MACHINE                        = 0x1
-	ICANON                            = 0x100
-	ICMP6_FILTER                      = 0x12
-	ICRNL                             = 0x100
-	IEXTEN                            = 0x400
-	IFF_ALLMULTI                      = 0x200
-	IFF_ALTPHYS                       = 0x4000
-	IFF_BROADCAST                     = 0x2
-	IFF_DEBUG                         = 0x4
-	IFF_LINK0                         = 0x1000
-	IFF_LINK1                         = 0x2000
-	IFF_LINK2                         = 0x4000
-	IFF_LOOPBACK                      = 0x8
-	IFF_MULTICAST                     = 0x8000
-	IFF_NOARP                         = 0x80
-	IFF_NOTRAILERS                    = 0x20
-	IFF_OACTIVE                       = 0x400
-	IFF_POINTOPOINT                   = 0x10
-	IFF_PROMISC                       = 0x100
-	IFF_RUNNING                       = 0x40
-	IFF_SIMPLEX                       = 0x800
-	IFF_UP                            = 0x1
-	IFNAMSIZ                          = 0x10
-	IFT_1822                          = 0x2
-	IFT_AAL5                          = 0x31
-	IFT_ARCNET                        = 0x23
-	IFT_ARCNETPLUS                    = 0x24
-	IFT_ATM                           = 0x25
-	IFT_BRIDGE                        = 0xd1
-	IFT_CARP                          = 0xf8
-	IFT_CELLULAR                      = 0xff
-	IFT_CEPT                          = 0x13
-	IFT_DS3                           = 0x1e
-	IFT_ENC                           = 0xf4
-	IFT_EON                           = 0x19
-	IFT_ETHER                         = 0x6
-	IFT_FAITH                         = 0x38
-	IFT_FDDI                          = 0xf
-	IFT_FRELAY                        = 0x20
-	IFT_FRELAYDCE                     = 0x2c
-	IFT_GIF                           = 0x37
-	IFT_HDH1822                       = 0x3
-	IFT_HIPPI                         = 0x2f
-	IFT_HSSI                          = 0x2e
-	IFT_HY                            = 0xe
-	IFT_IEEE1394                      = 0x90
-	IFT_IEEE8023ADLAG                 = 0x88
-	IFT_ISDNBASIC                     = 0x14
-	IFT_ISDNPRIMARY                   = 0x15
-	IFT_ISO88022LLC                   = 0x29
-	IFT_ISO88023                      = 0x7
-	IFT_ISO88024                      = 0x8
-	IFT_ISO88025                      = 0x9
-	IFT_ISO88026                      = 0xa
-	IFT_L2VLAN                        = 0x87
-	IFT_LAPB                          = 0x10
-	IFT_LOCALTALK                     = 0x2a
-	IFT_LOOP                          = 0x18
-	IFT_MIOX25                        = 0x26
-	IFT_MODEM                         = 0x30
-	IFT_NSIP                          = 0x1b
-	IFT_OTHER                         = 0x1
-	IFT_P10                           = 0xc
-	IFT_P80                           = 0xd
-	IFT_PARA                          = 0x22
-	IFT_PDP                           = 0xff
-	IFT_PFLOG                         = 0xf5
-	IFT_PFSYNC                        = 0xf6
-	IFT_PKTAP                         = 0xfe
-	IFT_PPP                           = 0x17
-	IFT_PROPMUX                       = 0x36
-	IFT_PROPVIRTUAL                   = 0x35
-	IFT_PTPSERIAL                     = 0x16
-	IFT_RS232                         = 0x21
-	IFT_SDLC                          = 0x11
-	IFT_SIP                           = 0x1f
-	IFT_SLIP                          = 0x1c
-	IFT_SMDSDXI                       = 0x2b
-	IFT_SMDSICIP                      = 0x34
-	IFT_SONET                         = 0x27
-	IFT_SONETPATH                     = 0x32
-	IFT_SONETVT                       = 0x33
-	IFT_STARLAN                       = 0xb
-	IFT_STF                           = 0x39
-	IFT_T1                            = 0x12
-	IFT_ULTRA                         = 0x1d
-	IFT_V35                           = 0x2d
-	IFT_X25                           = 0x5
-	IFT_X25DDN                        = 0x4
-	IFT_X25PLE                        = 0x28
-	IFT_XETHER                        = 0x1a
-	IGNBRK                            = 0x1
-	IGNCR                             = 0x80
-	IGNPAR                            = 0x4
-	IMAXBEL                           = 0x2000
-	INLCR                             = 0x40
-	INPCK                             = 0x10
-	IN_CLASSA_HOST                    = 0xffffff
-	IN_CLASSA_MAX                     = 0x80
-	IN_CLASSA_NET                     = 0xff000000
-	IN_CLASSA_NSHIFT                  = 0x18
-	IN_CLASSB_HOST                    = 0xffff
-	IN_CLASSB_MAX                     = 0x10000
-	IN_CLASSB_NET                     = 0xffff0000
-	IN_CLASSB_NSHIFT                  = 0x10
-	IN_CLASSC_HOST                    = 0xff
-	IN_CLASSC_NET                     = 0xffffff00
-	IN_CLASSC_NSHIFT                  = 0x8
-	IN_CLASSD_HOST                    = 0xfffffff
-	IN_CLASSD_NET                     = 0xf0000000
-	IN_CLASSD_NSHIFT                  = 0x1c
-	IN_LINKLOCALNETNUM                = 0xa9fe0000
-	IN_LOOPBACKNET                    = 0x7f
-	IPPROTO_3PC                       = 0x22
-	IPPROTO_ADFS                      = 0x44
-	IPPROTO_AH                        = 0x33
-	IPPROTO_AHIP                      = 0x3d
-	IPPROTO_APES                      = 0x63
-	IPPROTO_ARGUS                     = 0xd
-	IPPROTO_AX25                      = 0x5d
-	IPPROTO_BHA                       = 0x31
-	IPPROTO_BLT                       = 0x1e
-	IPPROTO_BRSATMON                  = 0x4c
-	IPPROTO_CFTP                      = 0x3e
-	IPPROTO_CHAOS                     = 0x10
-	IPPROTO_CMTP                      = 0x26
-	IPPROTO_CPHB                      = 0x49
-	IPPROTO_CPNX                      = 0x48
-	IPPROTO_DDP                       = 0x25
-	IPPROTO_DGP                       = 0x56
-	IPPROTO_DIVERT                    = 0xfe
-	IPPROTO_DONE                      = 0x101
-	IPPROTO_DSTOPTS                   = 0x3c
-	IPPROTO_EGP                       = 0x8
-	IPPROTO_EMCON                     = 0xe
-	IPPROTO_ENCAP                     = 0x62
-	IPPROTO_EON                       = 0x50
-	IPPROTO_ESP                       = 0x32
-	IPPROTO_ETHERIP                   = 0x61
-	IPPROTO_FRAGMENT                  = 0x2c
-	IPPROTO_GGP                       = 0x3
-	IPPROTO_GMTP                      = 0x64
-	IPPROTO_GRE                       = 0x2f
-	IPPROTO_HELLO                     = 0x3f
-	IPPROTO_HMP                       = 0x14
-	IPPROTO_HOPOPTS                   = 0x0
-	IPPROTO_ICMP                      = 0x1
-	IPPROTO_ICMPV6                    = 0x3a
-	IPPROTO_IDP                       = 0x16
-	IPPROTO_IDPR                      = 0x23
-	IPPROTO_IDRP                      = 0x2d
-	IPPROTO_IGMP                      = 0x2
-	IPPROTO_IGP                       = 0x55
-	IPPROTO_IGRP                      = 0x58
-	IPPROTO_IL                        = 0x28
-	IPPROTO_INLSP                     = 0x34
-	IPPROTO_INP                       = 0x20
-	IPPROTO_IP                        = 0x0
-	IPPROTO_IPCOMP                    = 0x6c
-	IPPROTO_IPCV                      = 0x47
-	IPPROTO_IPEIP                     = 0x5e
-	IPPROTO_IPIP                      = 0x4
-	IPPROTO_IPPC                      = 0x43
-	IPPROTO_IPV4                      = 0x4
-	IPPROTO_IPV6                      = 0x29
-	IPPROTO_IRTP                      = 0x1c
-	IPPROTO_KRYPTOLAN                 = 0x41
-	IPPROTO_LARP                      = 0x5b
-	IPPROTO_LEAF1                     = 0x19
-	IPPROTO_LEAF2                     = 0x1a
-	IPPROTO_MAX                       = 0x100
-	IPPROTO_MAXID                     = 0x34
-	IPPROTO_MEAS                      = 0x13
-	IPPROTO_MHRP                      = 0x30
-	IPPROTO_MICP                      = 0x5f
-	IPPROTO_MTP                       = 0x5c
-	IPPROTO_MUX                       = 0x12
-	IPPROTO_ND                        = 0x4d
-	IPPROTO_NHRP                      = 0x36
-	IPPROTO_NONE                      = 0x3b
-	IPPROTO_NSP                       = 0x1f
-	IPPROTO_NVPII                     = 0xb
-	IPPROTO_OSPFIGP                   = 0x59
-	IPPROTO_PGM                       = 0x71
-	IPPROTO_PIGP                      = 0x9
-	IPPROTO_PIM                       = 0x67
-	IPPROTO_PRM                       = 0x15
-	IPPROTO_PUP                       = 0xc
-	IPPROTO_PVP                       = 0x4b
-	IPPROTO_RAW                       = 0xff
-	IPPROTO_RCCMON                    = 0xa
-	IPPROTO_RDP                       = 0x1b
-	IPPROTO_ROUTING                   = 0x2b
-	IPPROTO_RSVP                      = 0x2e
-	IPPROTO_RVD                       = 0x42
-	IPPROTO_SATEXPAK                  = 0x40
-	IPPROTO_SATMON                    = 0x45
-	IPPROTO_SCCSP                     = 0x60
-	IPPROTO_SCTP                      = 0x84
-	IPPROTO_SDRP                      = 0x2a
-	IPPROTO_SEP                       = 0x21
-	IPPROTO_SRPC                      = 0x5a
-	IPPROTO_ST                        = 0x7
-	IPPROTO_SVMTP                     = 0x52
-	IPPROTO_SWIPE                     = 0x35
-	IPPROTO_TCF                       = 0x57
-	IPPROTO_TCP                       = 0x6
-	IPPROTO_TP                        = 0x1d
-	IPPROTO_TPXX                      = 0x27
-	IPPROTO_TRUNK1                    = 0x17
-	IPPROTO_TRUNK2                    = 0x18
-	IPPROTO_TTP                       = 0x54
-	IPPROTO_UDP                       = 0x11
-	IPPROTO_VINES                     = 0x53
-	IPPROTO_VISA                      = 0x46
-	IPPROTO_VMTP                      = 0x51
-	IPPROTO_WBEXPAK                   = 0x4f
-	IPPROTO_WBMON                     = 0x4e
-	IPPROTO_WSN                       = 0x4a
-	IPPROTO_XNET                      = 0xf
-	IPPROTO_XTP                       = 0x24
-	IPV6_2292DSTOPTS                  = 0x17
-	IPV6_2292HOPLIMIT                 = 0x14
-	IPV6_2292HOPOPTS                  = 0x16
-	IPV6_2292NEXTHOP                  = 0x15
-	IPV6_2292PKTINFO                  = 0x13
-	IPV6_2292PKTOPTIONS               = 0x19
-	IPV6_2292RTHDR                    = 0x18
-	IPV6_BINDV6ONLY                   = 0x1b
-	IPV6_BOUND_IF                     = 0x7d
-	IPV6_CHECKSUM                     = 0x1a
-	IPV6_DEFAULT_MULTICAST_HOPS       = 0x1
-	IPV6_DEFAULT_MULTICAST_LOOP       = 0x1
-	IPV6_DEFHLIM                      = 0x40
-	IPV6_FAITH                        = 0x1d
-	IPV6_FLOWINFO_MASK                = 0xffffff0f
-	IPV6_FLOWLABEL_MASK               = 0xffff0f00
-	IPV6_FLOW_ECN_MASK                = 0x300
-	IPV6_FRAGTTL                      = 0x3c
-	IPV6_FW_ADD                       = 0x1e
-	IPV6_FW_DEL                       = 0x1f
-	IPV6_FW_FLUSH                     = 0x20
-	IPV6_FW_GET                       = 0x22
-	IPV6_FW_ZERO                      = 0x21
-	IPV6_HLIMDEC                      = 0x1
-	IPV6_IPSEC_POLICY                 = 0x1c
-	IPV6_JOIN_GROUP                   = 0xc
-	IPV6_LEAVE_GROUP                  = 0xd
-	IPV6_MAXHLIM                      = 0xff
-	IPV6_MAXOPTHDR                    = 0x800
-	IPV6_MAXPACKET                    = 0xffff
-	IPV6_MAX_GROUP_SRC_FILTER         = 0x200
-	IPV6_MAX_MEMBERSHIPS              = 0xfff
-	IPV6_MAX_SOCK_SRC_FILTER          = 0x80
-	IPV6_MIN_MEMBERSHIPS              = 0x1f
-	IPV6_MMTU                         = 0x500
-	IPV6_MULTICAST_HOPS               = 0xa
-	IPV6_MULTICAST_IF                 = 0x9
-	IPV6_MULTICAST_LOOP               = 0xb
-	IPV6_PORTRANGE                    = 0xe
-	IPV6_PORTRANGE_DEFAULT            = 0x0
-	IPV6_PORTRANGE_HIGH               = 0x1
-	IPV6_PORTRANGE_LOW                = 0x2
-	IPV6_RECVTCLASS                   = 0x23
-	IPV6_RTHDR_LOOSE                  = 0x0
-	IPV6_RTHDR_STRICT                 = 0x1
-	IPV6_RTHDR_TYPE_0                 = 0x0
-	IPV6_SOCKOPT_RESERVED1            = 0x3
-	IPV6_TCLASS                       = 0x24
-	IPV6_UNICAST_HOPS                 = 0x4
-	IPV6_V6ONLY                       = 0x1b
-	IPV6_VERSION                      = 0x60
-	IPV6_VERSION_MASK                 = 0xf0
-	IP_ADD_MEMBERSHIP                 = 0xc
-	IP_ADD_SOURCE_MEMBERSHIP          = 0x46
-	IP_BLOCK_SOURCE                   = 0x48
-	IP_BOUND_IF                       = 0x19
-	IP_DEFAULT_MULTICAST_LOOP         = 0x1
-	IP_DEFAULT_MULTICAST_TTL          = 0x1
-	IP_DF                             = 0x4000
-	IP_DROP_MEMBERSHIP                = 0xd
-	IP_DROP_SOURCE_MEMBERSHIP         = 0x47
-	IP_DUMMYNET_CONFIGURE             = 0x3c
-	IP_DUMMYNET_DEL                   = 0x3d
-	IP_DUMMYNET_FLUSH                 = 0x3e
-	IP_DUMMYNET_GET                   = 0x40
-	IP_FAITH                          = 0x16
-	IP_FW_ADD                         = 0x28
-	IP_FW_DEL                         = 0x29
-	IP_FW_FLUSH                       = 0x2a
-	IP_FW_GET                         = 0x2c
-	IP_FW_RESETLOG                    = 0x2d
-	IP_FW_ZERO                        = 0x2b
-	IP_HDRINCL                        = 0x2
-	IP_IPSEC_POLICY                   = 0x15
-	IP_MAXPACKET                      = 0xffff
-	IP_MAX_GROUP_SRC_FILTER           = 0x200
-	IP_MAX_MEMBERSHIPS                = 0xfff
-	IP_MAX_SOCK_MUTE_FILTER           = 0x80
-	IP_MAX_SOCK_SRC_FILTER            = 0x80
-	IP_MF                             = 0x2000
-	IP_MIN_MEMBERSHIPS                = 0x1f
-	IP_MSFILTER                       = 0x4a
-	IP_MSS                            = 0x240
-	IP_MULTICAST_IF                   = 0x9
-	IP_MULTICAST_IFINDEX              = 0x42
-	IP_MULTICAST_LOOP                 = 0xb
-	IP_MULTICAST_TTL                  = 0xa
-	IP_MULTICAST_VIF                  = 0xe
-	IP_NAT__XXX                       = 0x37
-	IP_OFFMASK                        = 0x1fff
-	IP_OLD_FW_ADD                     = 0x32
-	IP_OLD_FW_DEL                     = 0x33
-	IP_OLD_FW_FLUSH                   = 0x34
-	IP_OLD_FW_GET                     = 0x36
-	IP_OLD_FW_RESETLOG                = 0x38
-	IP_OLD_FW_ZERO                    = 0x35
-	IP_OPTIONS                        = 0x1
-	IP_PKTINFO                        = 0x1a
-	IP_PORTRANGE                      = 0x13
-	IP_PORTRANGE_DEFAULT              = 0x0
-	IP_PORTRANGE_HIGH                 = 0x1
-	IP_PORTRANGE_LOW                  = 0x2
-	IP_RECVDSTADDR                    = 0x7
-	IP_RECVIF                         = 0x14
-	IP_RECVOPTS                       = 0x5
-	IP_RECVPKTINFO                    = 0x1a
-	IP_RECVRETOPTS                    = 0x6
-	IP_RECVTOS                        = 0x1b
-	IP_RECVTTL                        = 0x18
-	IP_RETOPTS                        = 0x8
-	IP_RF                             = 0x8000
-	IP_RSVP_OFF                       = 0x10
-	IP_RSVP_ON                        = 0xf
-	IP_RSVP_VIF_OFF                   = 0x12
-	IP_RSVP_VIF_ON                    = 0x11
-	IP_STRIPHDR                       = 0x17
-	IP_TOS                            = 0x3
-	IP_TRAFFIC_MGT_BACKGROUND         = 0x41
-	IP_TTL                            = 0x4
-	IP_UNBLOCK_SOURCE                 = 0x49
-	ISIG                              = 0x80
-	ISTRIP                            = 0x20
-	IUTF8                             = 0x4000
-	IXANY                             = 0x800
-	IXOFF                             = 0x400
-	IXON                              = 0x200
-	KERN_HOSTNAME                     = 0xa
-	KERN_OSRELEASE                    = 0x2
-	KERN_OSTYPE                       = 0x1
-	KERN_VERSION                      = 0x4
-	LOCK_EX                           = 0x2
-	LOCK_NB                           = 0x4
-	LOCK_SH                           = 0x1
-	LOCK_UN                           = 0x8
-	MADV_CAN_REUSE                    = 0x9
-	MADV_DONTNEED                     = 0x4
-	MADV_FREE                         = 0x5
-	MADV_FREE_REUSABLE                = 0x7
-	MADV_FREE_REUSE                   = 0x8
-	MADV_NORMAL                       = 0x0
-	MADV_PAGEOUT                      = 0xa
-	MADV_RANDOM                       = 0x1
-	MADV_SEQUENTIAL                   = 0x2
-	MADV_WILLNEED                     = 0x3
-	MADV_ZERO_WIRED_PAGES             = 0x6
-	MAP_ANON                          = 0x1000
-	MAP_ANONYMOUS                     = 0x1000
-	MAP_COPY                          = 0x2
-	MAP_FILE                          = 0x0
-	MAP_FIXED                         = 0x10
-	MAP_HASSEMAPHORE                  = 0x200
-	MAP_JIT                           = 0x800
-	MAP_NOCACHE                       = 0x400
-	MAP_NOEXTEND                      = 0x100
-	MAP_NORESERVE                     = 0x40
-	MAP_PRIVATE                       = 0x2
-	MAP_RENAME                        = 0x20
-	MAP_RESERVED0080                  = 0x80
-	MAP_RESILIENT_CODESIGN            = 0x2000
-	MAP_RESILIENT_MEDIA               = 0x4000
-	MAP_SHARED                        = 0x1
-	MCL_CURRENT                       = 0x1
-	MCL_FUTURE                        = 0x2
-	MNT_ASYNC                         = 0x40
-	MNT_AUTOMOUNTED                   = 0x400000
-	MNT_CMDFLAGS                      = 0xf0000
-	MNT_CPROTECT                      = 0x80
-	MNT_DEFWRITE                      = 0x2000000
-	MNT_DONTBROWSE                    = 0x100000
-	MNT_DOVOLFS                       = 0x8000
-	MNT_DWAIT                         = 0x4
-	MNT_EXPORTED                      = 0x100
-	MNT_FORCE                         = 0x80000
-	MNT_IGNORE_OWNERSHIP              = 0x200000
-	MNT_JOURNALED                     = 0x800000
-	MNT_LOCAL                         = 0x1000
-	MNT_MULTILABEL                    = 0x4000000
-	MNT_NOATIME                       = 0x10000000
-	MNT_NOBLOCK                       = 0x20000
-	MNT_NODEV                         = 0x10
-	MNT_NOEXEC                        = 0x4
-	MNT_NOSUID                        = 0x8
-	MNT_NOUSERXATTR                   = 0x1000000
-	MNT_NOWAIT                        = 0x2
-	MNT_QUARANTINE                    = 0x400
-	MNT_QUOTA                         = 0x2000
-	MNT_RDONLY                        = 0x1
-	MNT_RELOAD                        = 0x40000
-	MNT_ROOTFS                        = 0x4000
-	MNT_SYNCHRONOUS                   = 0x2
-	MNT_UNION                         = 0x20
-	MNT_UNKNOWNPERMISSIONS            = 0x200000
-	MNT_UPDATE                        = 0x10000
-	MNT_VISFLAGMASK                   = 0x17f0f5ff
-	MNT_WAIT                          = 0x1
-	MSG_CTRUNC                        = 0x20
-	MSG_DONTROUTE                     = 0x4
-	MSG_DONTWAIT                      = 0x80
-	MSG_EOF                           = 0x100
-	MSG_EOR                           = 0x8
-	MSG_FLUSH                         = 0x400
-	MSG_HAVEMORE                      = 0x2000
-	MSG_HOLD                          = 0x800
-	MSG_NEEDSA                        = 0x10000
-	MSG_OOB                           = 0x1
-	MSG_PEEK                          = 0x2
-	MSG_RCVMORE                       = 0x4000
-	MSG_SEND                          = 0x1000
-	MSG_TRUNC                         = 0x10
-	MSG_WAITALL                       = 0x40
-	MSG_WAITSTREAM                    = 0x200
-	MS_ASYNC                          = 0x1
-	MS_DEACTIVATE                     = 0x8
-	MS_INVALIDATE                     = 0x2
-	MS_KILLPAGES                      = 0x4
-	MS_SYNC                           = 0x10
-	NAME_MAX                          = 0xff
-	NET_RT_DUMP                       = 0x1
-	NET_RT_DUMP2                      = 0x7
-	NET_RT_FLAGS                      = 0x2
-	NET_RT_IFLIST                     = 0x3
-	NET_RT_IFLIST2                    = 0x6
-	NET_RT_MAXID                      = 0xa
-	NET_RT_STAT                       = 0x4
-	NET_RT_TRASH                      = 0x5
-	NFDBITS                           = 0x20
-	NL0                               = 0x0
-	NL1                               = 0x100
-	NL2                               = 0x200
-	NL3                               = 0x300
-	NLDLY                             = 0x300
-	NOFLSH                            = 0x80000000
-	NOKERNINFO                        = 0x2000000
-	NOTE_ABSOLUTE                     = 0x8
-	NOTE_ATTRIB                       = 0x8
-	NOTE_BACKGROUND                   = 0x40
-	NOTE_CHILD                        = 0x4
-	NOTE_CRITICAL                     = 0x20
-	NOTE_DELETE                       = 0x1
-	NOTE_EXEC                         = 0x20000000
-	NOTE_EXIT                         = 0x80000000
-	NOTE_EXITSTATUS                   = 0x4000000
-	NOTE_EXIT_CSERROR                 = 0x40000
-	NOTE_EXIT_DECRYPTFAIL             = 0x10000
-	NOTE_EXIT_DETAIL                  = 0x2000000
-	NOTE_EXIT_DETAIL_MASK             = 0x70000
-	NOTE_EXIT_MEMORY                  = 0x20000
-	NOTE_EXIT_REPARENTED              = 0x80000
-	NOTE_EXTEND                       = 0x4
-	NOTE_FFAND                        = 0x40000000
-	NOTE_FFCOPY                       = 0xc0000000
-	NOTE_FFCTRLMASK                   = 0xc0000000
-	NOTE_FFLAGSMASK                   = 0xffffff
-	NOTE_FFNOP                        = 0x0
-	NOTE_FFOR                         = 0x80000000
-	NOTE_FORK                         = 0x40000000
-	NOTE_FUNLOCK                      = 0x100
-	NOTE_LEEWAY                       = 0x10
-	NOTE_LINK                         = 0x10
-	NOTE_LOWAT                        = 0x1
-	NOTE_MACH_CONTINUOUS_TIME         = 0x80
-	NOTE_NONE                         = 0x80
-	NOTE_NSECONDS                     = 0x4
-	NOTE_OOB                          = 0x2
-	NOTE_PCTRLMASK                    = -0x100000
-	NOTE_PDATAMASK                    = 0xfffff
-	NOTE_REAP                         = 0x10000000
-	NOTE_RENAME                       = 0x20
-	NOTE_REVOKE                       = 0x40
-	NOTE_SECONDS                      = 0x1
-	NOTE_SIGNAL                       = 0x8000000
-	NOTE_TRACK                        = 0x1
-	NOTE_TRACKERR                     = 0x2
-	NOTE_TRIGGER                      = 0x1000000
-	NOTE_USECONDS                     = 0x2
-	NOTE_VM_ERROR                     = 0x10000000
-	NOTE_VM_PRESSURE                  = 0x80000000
-	NOTE_VM_PRESSURE_SUDDEN_TERMINATE = 0x20000000
-	NOTE_VM_PRESSURE_TERMINATE        = 0x40000000
-	NOTE_WRITE                        = 0x2
-	OCRNL                             = 0x10
-	OFDEL                             = 0x20000
-	OFILL                             = 0x80
-	ONLCR                             = 0x2
-	ONLRET                            = 0x40
-	ONOCR                             = 0x20
-	ONOEOT                            = 0x8
-	OPOST                             = 0x1
-	OXTABS                            = 0x4
-	O_ACCMODE                         = 0x3
-	O_ALERT                           = 0x20000000
-	O_APPEND                          = 0x8
-	O_ASYNC                           = 0x40
-	O_CLOEXEC                         = 0x1000000
-	O_CREAT                           = 0x200
-	O_DIRECTORY                       = 0x100000
-	O_DP_GETRAWENCRYPTED              = 0x1
-	O_DP_GETRAWUNENCRYPTED            = 0x2
-	O_DSYNC                           = 0x400000
-	O_EVTONLY                         = 0x8000
-	O_EXCL                            = 0x800
-	O_EXLOCK                          = 0x20
-	O_FSYNC                           = 0x80
-	O_NDELAY                          = 0x4
-	O_NOCTTY                          = 0x20000
-	O_NOFOLLOW                        = 0x100
-	O_NONBLOCK                        = 0x4
-	O_POPUP                           = 0x80000000
-	O_RDONLY                          = 0x0
-	O_RDWR                            = 0x2
-	O_SHLOCK                          = 0x10
-	O_SYMLINK                         = 0x200000
-	O_SYNC                            = 0x80
-	O_TRUNC                           = 0x400
-	O_WRONLY                          = 0x1
-	PARENB                            = 0x1000
-	PARMRK                            = 0x8
-	PARODD                            = 0x2000
-	PENDIN                            = 0x20000000
-	PRIO_PGRP                         = 0x1
-	PRIO_PROCESS                      = 0x0
-	PRIO_USER                         = 0x2
-	PROT_EXEC                         = 0x4
-	PROT_NONE                         = 0x0
-	PROT_READ                         = 0x1
-	PROT_WRITE                        = 0x2
-	PT_ATTACH                         = 0xa
-	PT_ATTACHEXC                      = 0xe
-	PT_CONTINUE                       = 0x7
-	PT_DENY_ATTACH                    = 0x1f
-	PT_DETACH                         = 0xb
-	PT_FIRSTMACH                      = 0x20
-	PT_FORCEQUOTA                     = 0x1e
-	PT_KILL                           = 0x8
-	PT_READ_D                         = 0x2
-	PT_READ_I                         = 0x1
-	PT_READ_U                         = 0x3
-	PT_SIGEXC                         = 0xc
-	PT_STEP                           = 0x9
-	PT_THUPDATE                       = 0xd
-	PT_TRACE_ME                       = 0x0
-	PT_WRITE_D                        = 0x5
-	PT_WRITE_I                        = 0x4
-	PT_WRITE_U                        = 0x6
-	RLIMIT_AS                         = 0x5
-	RLIMIT_CORE                       = 0x4
-	RLIMIT_CPU                        = 0x0
-	RLIMIT_CPU_USAGE_MONITOR          = 0x2
-	RLIMIT_DATA                       = 0x2
-	RLIMIT_FSIZE                      = 0x1
-	RLIMIT_MEMLOCK                    = 0x6
-	RLIMIT_NOFILE                     = 0x8
-	RLIMIT_NPROC                      = 0x7
-	RLIMIT_RSS                        = 0x5
-	RLIMIT_STACK                      = 0x3
-	RLIM_INFINITY                     = 0x7fffffffffffffff
-	RTAX_AUTHOR                       = 0x6
-	RTAX_BRD                          = 0x7
-	RTAX_DST                          = 0x0
-	RTAX_GATEWAY                      = 0x1
-	RTAX_GENMASK                      = 0x3
-	RTAX_IFA                          = 0x5
-	RTAX_IFP                          = 0x4
-	RTAX_MAX                          = 0x8
-	RTAX_NETMASK                      = 0x2
-	RTA_AUTHOR                        = 0x40
-	RTA_BRD                           = 0x80
-	RTA_DST                           = 0x1
-	RTA_GATEWAY                       = 0x2
-	RTA_GENMASK                       = 0x8
-	RTA_IFA                           = 0x20
-	RTA_IFP                           = 0x10
-	RTA_NETMASK                       = 0x4
-	RTF_BLACKHOLE                     = 0x1000
-	RTF_BROADCAST                     = 0x400000
-	RTF_CLONING                       = 0x100
-	RTF_CONDEMNED                     = 0x2000000
-	RTF_DELCLONE                      = 0x80
-	RTF_DONE                          = 0x40
-	RTF_DYNAMIC                       = 0x10
-	RTF_GATEWAY                       = 0x2
-	RTF_HOST                          = 0x4
-	RTF_IFREF                         = 0x4000000
-	RTF_IFSCOPE                       = 0x1000000
-	RTF_LLINFO                        = 0x400
-	RTF_LOCAL                         = 0x200000
-	RTF_MODIFIED                      = 0x20
-	RTF_MULTICAST                     = 0x800000
-	RTF_NOIFREF                       = 0x2000
-	RTF_PINNED                        = 0x100000
-	RTF_PRCLONING                     = 0x10000
-	RTF_PROTO1                        = 0x8000
-	RTF_PROTO2                        = 0x4000
-	RTF_PROTO3                        = 0x40000
-	RTF_PROXY                         = 0x8000000
-	RTF_REJECT                        = 0x8
-	RTF_ROUTER                        = 0x10000000
-	RTF_STATIC                        = 0x800
-	RTF_UP                            = 0x1
-	RTF_WASCLONED                     = 0x20000
-	RTF_XRESOLVE                      = 0x200
-	RTM_ADD                           = 0x1
-	RTM_CHANGE                        = 0x3
-	RTM_DELADDR                       = 0xd
-	RTM_DELETE                        = 0x2
-	RTM_DELMADDR                      = 0x10
-	RTM_GET                           = 0x4
-	RTM_GET2                          = 0x14
-	RTM_IFINFO                        = 0xe
-	RTM_IFINFO2                       = 0x12
-	RTM_LOCK                          = 0x8
-	RTM_LOSING                        = 0x5
-	RTM_MISS                          = 0x7
-	RTM_NEWADDR                       = 0xc
-	RTM_NEWMADDR                      = 0xf
-	RTM_NEWMADDR2                     = 0x13
-	RTM_OLDADD                        = 0x9
-	RTM_OLDDEL                        = 0xa
-	RTM_REDIRECT                      = 0x6
-	RTM_RESOLVE                       = 0xb
-	RTM_RTTUNIT                       = 0xf4240
-	RTM_VERSION                       = 0x5
-	RTV_EXPIRE                        = 0x4
-	RTV_HOPCOUNT                      = 0x2
-	RTV_MTU                           = 0x1
-	RTV_RPIPE                         = 0x8
-	RTV_RTT                           = 0x40
-	RTV_RTTVAR                        = 0x80
-	RTV_SPIPE                         = 0x10
-	RTV_SSTHRESH                      = 0x20
-	RUSAGE_CHILDREN                   = -0x1
-	RUSAGE_SELF                       = 0x0
-	SCM_CREDS                         = 0x3
-	SCM_RIGHTS                        = 0x1
-	SCM_TIMESTAMP                     = 0x2
-	SCM_TIMESTAMP_MONOTONIC           = 0x4
-	SHUT_RD                           = 0x0
-	SHUT_RDWR                         = 0x2
-	SHUT_WR                           = 0x1
-	SIOCADDMULTI                      = 0x80206931
-	SIOCAIFADDR                       = 0x8040691a
-	SIOCARPIPLL                       = 0xc0206928
-	SIOCATMARK                        = 0x40047307
-	SIOCAUTOADDR                      = 0xc0206926
-	SIOCAUTONETMASK                   = 0x80206927
-	SIOCDELMULTI                      = 0x80206932
-	SIOCDIFADDR                       = 0x80206919
-	SIOCDIFPHYADDR                    = 0x80206941
-	SIOCGDRVSPEC                      = 0xc01c697b
-	SIOCGETVLAN                       = 0xc020697f
-	SIOCGHIWAT                        = 0x40047301
-	SIOCGIFADDR                       = 0xc0206921
-	SIOCGIFALTMTU                     = 0xc0206948
-	SIOCGIFASYNCMAP                   = 0xc020697c
-	SIOCGIFBOND                       = 0xc0206947
-	SIOCGIFBRDADDR                    = 0xc0206923
-	SIOCGIFCAP                        = 0xc020695b
-	SIOCGIFCONF                       = 0xc0086924
-	SIOCGIFDEVMTU                     = 0xc0206944
-	SIOCGIFDSTADDR                    = 0xc0206922
-	SIOCGIFFLAGS                      = 0xc0206911
-	SIOCGIFGENERIC                    = 0xc020693a
-	SIOCGIFKPI                        = 0xc0206987
-	SIOCGIFMAC                        = 0xc0206982
-	SIOCGIFMEDIA                      = 0xc0286938
-	SIOCGIFMETRIC                     = 0xc0206917
-	SIOCGIFMTU                        = 0xc0206933
-	SIOCGIFNETMASK                    = 0xc0206925
-	SIOCGIFPDSTADDR                   = 0xc0206940
-	SIOCGIFPHYS                       = 0xc0206935
-	SIOCGIFPSRCADDR                   = 0xc020693f
-	SIOCGIFSTATUS                     = 0xc331693d
-	SIOCGIFVLAN                       = 0xc020697f
-	SIOCGIFWAKEFLAGS                  = 0xc0206988
-	SIOCGLOWAT                        = 0x40047303
-	SIOCGPGRP                         = 0x40047309
-	SIOCIFCREATE                      = 0xc0206978
-	SIOCIFCREATE2                     = 0xc020697a
-	SIOCIFDESTROY                     = 0x80206979
-	SIOCIFGCLONERS                    = 0xc00c6981
-	SIOCRSLVMULTI                     = 0xc008693b
-	SIOCSDRVSPEC                      = 0x801c697b
-	SIOCSETVLAN                       = 0x8020697e
-	SIOCSHIWAT                        = 0x80047300
-	SIOCSIFADDR                       = 0x8020690c
-	SIOCSIFALTMTU                     = 0x80206945
-	SIOCSIFASYNCMAP                   = 0x8020697d
-	SIOCSIFBOND                       = 0x80206946
-	SIOCSIFBRDADDR                    = 0x80206913
-	SIOCSIFCAP                        = 0x8020695a
-	SIOCSIFDSTADDR                    = 0x8020690e
-	SIOCSIFFLAGS                      = 0x80206910
-	SIOCSIFGENERIC                    = 0x80206939
-	SIOCSIFKPI                        = 0x80206986
-	SIOCSIFLLADDR                     = 0x8020693c
-	SIOCSIFMAC                        = 0x80206983
-	SIOCSIFMEDIA                      = 0xc0206937
-	SIOCSIFMETRIC                     = 0x80206918
-	SIOCSIFMTU                        = 0x80206934
-	SIOCSIFNETMASK                    = 0x80206916
-	SIOCSIFPHYADDR                    = 0x8040693e
-	SIOCSIFPHYS                       = 0x80206936
-	SIOCSIFVLAN                       = 0x8020697e
-	SIOCSLOWAT                        = 0x80047302
-	SIOCSPGRP                         = 0x80047308
-	SOCK_DGRAM                        = 0x2
-	SOCK_MAXADDRLEN                   = 0xff
-	SOCK_RAW                          = 0x3
-	SOCK_RDM                          = 0x4
-	SOCK_SEQPACKET                    = 0x5
-	SOCK_STREAM                       = 0x1
-	SOL_SOCKET                        = 0xffff
-	SOMAXCONN                         = 0x80
-	SO_ACCEPTCONN                     = 0x2
-	SO_BROADCAST                      = 0x20
-	SO_DEBUG                          = 0x1
-	SO_DONTROUTE                      = 0x10
-	SO_DONTTRUNC                      = 0x2000
-	SO_ERROR                          = 0x1007
-	SO_KEEPALIVE                      = 0x8
-	SO_LABEL                          = 0x1010
-	SO_LINGER                         = 0x80
-	SO_LINGER_SEC                     = 0x1080
-	SO_NETSVC_MARKING_LEVEL           = 0x1119
-	SO_NET_SERVICE_TYPE               = 0x1116
-	SO_NKE                            = 0x1021
-	SO_NOADDRERR                      = 0x1023
-	SO_NOSIGPIPE                      = 0x1022
-	SO_NOTIFYCONFLICT                 = 0x1026
-	SO_NP_EXTENSIONS                  = 0x1083
-	SO_NREAD                          = 0x1020
-	SO_NUMRCVPKT                      = 0x1112
-	SO_NWRITE                         = 0x1024
-	SO_OOBINLINE                      = 0x100
-	SO_PEERLABEL                      = 0x1011
-	SO_RANDOMPORT                     = 0x1082
-	SO_RCVBUF                         = 0x1002
-	SO_RCVLOWAT                       = 0x1004
-	SO_RCVTIMEO                       = 0x1006
-	SO_REUSEADDR                      = 0x4
-	SO_REUSEPORT                      = 0x200
-	SO_REUSESHAREUID                  = 0x1025
-	SO_SNDBUF                         = 0x1001
-	SO_SNDLOWAT                       = 0x1003
-	SO_SNDTIMEO                       = 0x1005
-	SO_TIMESTAMP                      = 0x400
-	SO_TIMESTAMP_MONOTONIC            = 0x800
-	SO_TYPE                           = 0x1008
-	SO_UPCALLCLOSEWAIT                = 0x1027
-	SO_USELOOPBACK                    = 0x40
-	SO_WANTMORE                       = 0x4000
-	SO_WANTOOBFLAG                    = 0x8000
-	S_IEXEC                           = 0x40
-	S_IFBLK                           = 0x6000
-	S_IFCHR                           = 0x2000
-	S_IFDIR                           = 0x4000
-	S_IFIFO                           = 0x1000
-	S_IFLNK                           = 0xa000
-	S_IFMT                            = 0xf000
-	S_IFREG                           = 0x8000
-	S_IFSOCK                          = 0xc000
-	S_IFWHT                           = 0xe000
-	S_IREAD                           = 0x100
-	S_IRGRP                           = 0x20
-	S_IROTH                           = 0x4
-	S_IRUSR                           = 0x100
-	S_IRWXG                           = 0x38
-	S_IRWXO                           = 0x7
-	S_IRWXU                           = 0x1c0
-	S_ISGID                           = 0x400
-	S_ISTXT                           = 0x200
-	S_ISUID                           = 0x800
-	S_ISVTX                           = 0x200
-	S_IWGRP                           = 0x10
-	S_IWOTH                           = 0x2
-	S_IWRITE                          = 0x80
-	S_IWUSR                           = 0x80
-	S_IXGRP                           = 0x8
-	S_IXOTH                           = 0x1
-	S_IXUSR                           = 0x40
-	TAB0                              = 0x0
-	TAB1                              = 0x400
-	TAB2                              = 0x800
-	TAB3                              = 0x4
-	TABDLY                            = 0xc04
-	TCIFLUSH                          = 0x1
-	TCIOFF                            = 0x3
-	TCIOFLUSH                         = 0x3
-	TCION                             = 0x4
-	TCOFLUSH                          = 0x2
-	TCOOFF                            = 0x1
-	TCOON                             = 0x2
-	TCP_CONNECTIONTIMEOUT             = 0x20
-	TCP_CONNECTION_INFO               = 0x106
-	TCP_ENABLE_ECN                    = 0x104
-	TCP_FASTOPEN                      = 0x105
-	TCP_KEEPALIVE                     = 0x10
-	TCP_KEEPCNT                       = 0x102
-	TCP_KEEPINTVL                     = 0x101
-	TCP_MAXHLEN                       = 0x3c
-	TCP_MAXOLEN                       = 0x28
-	TCP_MAXSEG                        = 0x2
-	TCP_MAXWIN                        = 0xffff
-	TCP_MAX_SACK                      = 0x4
-	TCP_MAX_WINSHIFT                  = 0xe
-	TCP_MINMSS                        = 0xd8
-	TCP_MSS                           = 0x200
-	TCP_NODELAY                       = 0x1
-	TCP_NOOPT                         = 0x8
-	TCP_NOPUSH                        = 0x4
-	TCP_NOTSENT_LOWAT                 = 0x201
-	TCP_RXT_CONNDROPTIME              = 0x80
-	TCP_RXT_FINDROP                   = 0x100
-	TCP_SENDMOREACKS                  = 0x103
-	TCSAFLUSH                         = 0x2
-	TIOCCBRK                          = 0x2000747a
-	TIOCCDTR                          = 0x20007478
-	TIOCCONS                          = 0x80047462
-	TIOCDCDTIMESTAMP                  = 0x40087458
-	TIOCDRAIN                         = 0x2000745e
-	TIOCDSIMICROCODE                  = 0x20007455
-	TIOCEXCL                          = 0x2000740d
-	TIOCEXT                           = 0x80047460
-	TIOCFLUSH                         = 0x80047410
-	TIOCGDRAINWAIT                    = 0x40047456
-	TIOCGETA                          = 0x402c7413
-	TIOCGETD                          = 0x4004741a
-	TIOCGPGRP                         = 0x40047477
-	TIOCGWINSZ                        = 0x40087468
-	TIOCIXOFF                         = 0x20007480
-	TIOCIXON                          = 0x20007481
-	TIOCMBIC                          = 0x8004746b
-	TIOCMBIS                          = 0x8004746c
-	TIOCMGDTRWAIT                     = 0x4004745a
-	TIOCMGET                          = 0x4004746a
-	TIOCMODG                          = 0x40047403
-	TIOCMODS                          = 0x80047404
-	TIOCMSDTRWAIT                     = 0x8004745b
-	TIOCMSET                          = 0x8004746d
-	TIOCM_CAR                         = 0x40
-	TIOCM_CD                          = 0x40
-	TIOCM_CTS                         = 0x20
-	TIOCM_DSR                         = 0x100
-	TIOCM_DTR                         = 0x2
-	TIOCM_LE                          = 0x1
-	TIOCM_RI                          = 0x80
-	TIOCM_RNG                         = 0x80
-	TIOCM_RTS                         = 0x4
-	TIOCM_SR                          = 0x10
-	TIOCM_ST                          = 0x8
-	TIOCNOTTY                         = 0x20007471
-	TIOCNXCL                          = 0x2000740e
-	TIOCOUTQ                          = 0x40047473
-	TIOCPKT                           = 0x80047470
-	TIOCPKT_DATA                      = 0x0
-	TIOCPKT_DOSTOP                    = 0x20
-	TIOCPKT_FLUSHREAD                 = 0x1
-	TIOCPKT_FLUSHWRITE                = 0x2
-	TIOCPKT_IOCTL                     = 0x40
-	TIOCPKT_NOSTOP                    = 0x10
-	TIOCPKT_START                     = 0x8
-	TIOCPKT_STOP                      = 0x4
-	TIOCPTYGNAME                      = 0x40807453
-	TIOCPTYGRANT                      = 0x20007454
-	TIOCPTYUNLK                       = 0x20007452
-	TIOCREMOTE                        = 0x80047469
-	TIOCSBRK                          = 0x2000747b
-	TIOCSCONS                         = 0x20007463
-	TIOCSCTTY                         = 0x20007461
-	TIOCSDRAINWAIT                    = 0x80047457
-	TIOCSDTR                          = 0x20007479
-	TIOCSETA                          = 0x802c7414
-	TIOCSETAF                         = 0x802c7416
-	TIOCSETAW                         = 0x802c7415
-	TIOCSETD                          = 0x8004741b
-	TIOCSIG                           = 0x2000745f
-	TIOCSPGRP                         = 0x80047476
-	TIOCSTART                         = 0x2000746e
-	TIOCSTAT                          = 0x20007465
-	TIOCSTI                           = 0x80017472
-	TIOCSTOP                          = 0x2000746f
-	TIOCSWINSZ                        = 0x80087467
-	TIOCTIMESTAMP                     = 0x40087459
-	TIOCUCNTL                         = 0x80047466
-	TOSTOP                            = 0x400000
-	VDISCARD                          = 0xf
-	VDSUSP                            = 0xb
-	VEOF                              = 0x0
-	VEOL                              = 0x1
-	VEOL2                             = 0x2
-	VERASE                            = 0x3
-	VINTR                             = 0x8
-	VKILL                             = 0x5
-	VLNEXT                            = 0xe
-	VMIN                              = 0x10
-	VM_LOADAVG                        = 0x2
-	VM_MACHFACTOR                     = 0x4
-	VM_MAXID                          = 0x6
-	VM_METER                          = 0x1
-	VM_SWAPUSAGE                      = 0x5
-	VQUIT                             = 0x9
-	VREPRINT                          = 0x6
-	VSTART                            = 0xc
-	VSTATUS                           = 0x12
-	VSTOP                             = 0xd
-	VSUSP                             = 0xa
-	VT0                               = 0x0
-	VT1                               = 0x10000
-	VTDLY                             = 0x10000
-	VTIME                             = 0x11
-	VWERASE                           = 0x4
-	WCONTINUED                        = 0x10
-	WCOREFLAG                         = 0x80
-	WEXITED                           = 0x4
-	WNOHANG                           = 0x1
-	WNOWAIT                           = 0x20
-	WORDSIZE                          = 0x20
-	WSTOPPED                          = 0x8
-	WUNTRACED                         = 0x2
-	XATTR_CREATE                      = 0x2
-	XATTR_NODEFAULT                   = 0x10
-	XATTR_NOFOLLOW                    = 0x1
-	XATTR_NOSECURITY                  = 0x8
-	XATTR_REPLACE                     = 0x4
-	XATTR_SHOWCOMPRESSION             = 0x20
-)
-
-// Errors
-const (
-	E2BIG           = syscall.Errno(0x7)
-	EACCES          = syscall.Errno(0xd)
-	EADDRINUSE      = syscall.Errno(0x30)
-	EADDRNOTAVAIL   = syscall.Errno(0x31)
-	EAFNOSUPPORT    = syscall.Errno(0x2f)
-	EAGAIN          = syscall.Errno(0x23)
-	EALREADY        = syscall.Errno(0x25)
-	EAUTH           = syscall.Errno(0x50)
-	EBADARCH        = syscall.Errno(0x56)
-	EBADEXEC        = syscall.Errno(0x55)
-	EBADF           = syscall.Errno(0x9)
-	EBADMACHO       = syscall.Errno(0x58)
-	EBADMSG         = syscall.Errno(0x5e)
-	EBADRPC         = syscall.Errno(0x48)
-	EBUSY           = syscall.Errno(0x10)
-	ECANCELED       = syscall.Errno(0x59)
-	ECHILD          = syscall.Errno(0xa)
-	ECONNABORTED    = syscall.Errno(0x35)
-	ECONNREFUSED    = syscall.Errno(0x3d)
-	ECONNRESET      = syscall.Errno(0x36)
-	EDEADLK         = syscall.Errno(0xb)
-	EDESTADDRREQ    = syscall.Errno(0x27)
-	EDEVERR         = syscall.Errno(0x53)
-	EDOM            = syscall.Errno(0x21)
-	EDQUOT          = syscall.Errno(0x45)
-	EEXIST          = syscall.Errno(0x11)
-	EFAULT          = syscall.Errno(0xe)
-	EFBIG           = syscall.Errno(0x1b)
-	EFTYPE          = syscall.Errno(0x4f)
-	EHOSTDOWN       = syscall.Errno(0x40)
-	EHOSTUNREACH    = syscall.Errno(0x41)
-	EIDRM           = syscall.Errno(0x5a)
-	EILSEQ          = syscall.Errno(0x5c)
-	EINPROGRESS     = syscall.Errno(0x24)
-	EINTR           = syscall.Errno(0x4)
-	EINVAL          = syscall.Errno(0x16)
-	EIO             = syscall.Errno(0x5)
-	EISCONN         = syscall.Errno(0x38)
-	EISDIR          = syscall.Errno(0x15)
-	ELAST           = syscall.Errno(0x6a)
-	ELOOP           = syscall.Errno(0x3e)
-	EMFILE          = syscall.Errno(0x18)
-	EMLINK          = syscall.Errno(0x1f)
-	EMSGSIZE        = syscall.Errno(0x28)
-	EMULTIHOP       = syscall.Errno(0x5f)
-	ENAMETOOLONG    = syscall.Errno(0x3f)
-	ENEEDAUTH       = syscall.Errno(0x51)
-	ENETDOWN        = syscall.Errno(0x32)
-	ENETRESET       = syscall.Errno(0x34)
-	ENETUNREACH     = syscall.Errno(0x33)
-	ENFILE          = syscall.Errno(0x17)
-	ENOATTR         = syscall.Errno(0x5d)
-	ENOBUFS         = syscall.Errno(0x37)
-	ENODATA         = syscall.Errno(0x60)
-	ENODEV          = syscall.Errno(0x13)
-	ENOENT          = syscall.Errno(0x2)
-	ENOEXEC         = syscall.Errno(0x8)
-	ENOLCK          = syscall.Errno(0x4d)
-	ENOLINK         = syscall.Errno(0x61)
-	ENOMEM          = syscall.Errno(0xc)
-	ENOMSG          = syscall.Errno(0x5b)
-	ENOPOLICY       = syscall.Errno(0x67)
-	ENOPROTOOPT     = syscall.Errno(0x2a)
-	ENOSPC          = syscall.Errno(0x1c)
-	ENOSR           = syscall.Errno(0x62)
-	ENOSTR          = syscall.Errno(0x63)
-	ENOSYS          = syscall.Errno(0x4e)
-	ENOTBLK         = syscall.Errno(0xf)
-	ENOTCONN        = syscall.Errno(0x39)
-	ENOTDIR         = syscall.Errno(0x14)
-	ENOTEMPTY       = syscall.Errno(0x42)
-	ENOTRECOVERABLE = syscall.Errno(0x68)
-	ENOTSOCK        = syscall.Errno(0x26)
-	ENOTSUP         = syscall.Errno(0x2d)
-	ENOTTY          = syscall.Errno(0x19)
-	ENXIO           = syscall.Errno(0x6)
-	EOPNOTSUPP      = syscall.Errno(0x66)
-	EOVERFLOW       = syscall.Errno(0x54)
-	EOWNERDEAD      = syscall.Errno(0x69)
-	EPERM           = syscall.Errno(0x1)
-	EPFNOSUPPORT    = syscall.Errno(0x2e)
-	EPIPE           = syscall.Errno(0x20)
-	EPROCLIM        = syscall.Errno(0x43)
-	EPROCUNAVAIL    = syscall.Errno(0x4c)
-	EPROGMISMATCH   = syscall.Errno(0x4b)
-	EPROGUNAVAIL    = syscall.Errno(0x4a)
-	EPROTO          = syscall.Errno(0x64)
-	EPROTONOSUPPORT = syscall.Errno(0x2b)
-	EPROTOTYPE      = syscall.Errno(0x29)
-	EPWROFF         = syscall.Errno(0x52)
-	EQFULL          = syscall.Errno(0x6a)
-	ERANGE          = syscall.Errno(0x22)
-	EREMOTE         = syscall.Errno(0x47)
-	EROFS           = syscall.Errno(0x1e)
-	ERPCMISMATCH    = syscall.Errno(0x49)
-	ESHLIBVERS      = syscall.Errno(0x57)
-	ESHUTDOWN       = syscall.Errno(0x3a)
-	ESOCKTNOSUPPORT = syscall.Errno(0x2c)
-	ESPIPE          = syscall.Errno(0x1d)
-	ESRCH           = syscall.Errno(0x3)
-	ESTALE          = syscall.Errno(0x46)
-	ETIME           = syscall.Errno(0x65)
-	ETIMEDOUT       = syscall.Errno(0x3c)
-	ETOOMANYREFS    = syscall.Errno(0x3b)
-	ETXTBSY         = syscall.Errno(0x1a)
-	EUSERS          = syscall.Errno(0x44)
-	EWOULDBLOCK     = syscall.Errno(0x23)
-	EXDEV           = syscall.Errno(0x12)
-)
-
-// Signals
-const (
-	SIGABRT   = syscall.Signal(0x6)
-	SIGALRM   = syscall.Signal(0xe)
-	SIGBUS    = syscall.Signal(0xa)
-	SIGCHLD   = syscall.Signal(0x14)
-	SIGCONT   = syscall.Signal(0x13)
-	SIGEMT    = syscall.Signal(0x7)
-	SIGFPE    = syscall.Signal(0x8)
-	SIGHUP    = syscall.Signal(0x1)
-	SIGILL    = syscall.Signal(0x4)
-	SIGINFO   = syscall.Signal(0x1d)
-	SIGINT    = syscall.Signal(0x2)
-	SIGIO     = syscall.Signal(0x17)
-	SIGIOT    = syscall.Signal(0x6)
-	SIGKILL   = syscall.Signal(0x9)
-	SIGPIPE   = syscall.Signal(0xd)
-	SIGPROF   = syscall.Signal(0x1b)
-	SIGQUIT   = syscall.Signal(0x3)
-	SIGSEGV   = syscall.Signal(0xb)
-	SIGSTOP   = syscall.Signal(0x11)
-	SIGSYS    = syscall.Signal(0xc)
-	SIGTERM   = syscall.Signal(0xf)
-	SIGTRAP   = syscall.Signal(0x5)
-	SIGTSTP   = syscall.Signal(0x12)
-	SIGTTIN   = syscall.Signal(0x15)
-	SIGTTOU   = syscall.Signal(0x16)
-	SIGURG    = syscall.Signal(0x10)
-	SIGUSR1   = syscall.Signal(0x1e)
-	SIGUSR2   = syscall.Signal(0x1f)
-	SIGVTALRM = syscall.Signal(0x1a)
-	SIGWINCH  = syscall.Signal(0x1c)
-	SIGXCPU   = syscall.Signal(0x18)
-	SIGXFSZ   = syscall.Signal(0x19)
-)
-
-// Error table
-var errorList = [...]struct {
-	num  syscall.Errno
-	name string
-	desc string
-}{
-	{1, "EPERM", "operation not permitted"},
-	{2, "ENOENT", "no such file or directory"},
-	{3, "ESRCH", "no such process"},
-	{4, "EINTR", "interrupted system call"},
-	{5, "EIO", "input/output error"},
-	{6, "ENXIO", "device not configured"},
-	{7, "E2BIG", "argument list too long"},
-	{8, "ENOEXEC", "exec format error"},
-	{9, "EBADF", "bad file descriptor"},
-	{10, "ECHILD", "no child processes"},
-	{11, "EDEADLK", "resource deadlock avoided"},
-	{12, "ENOMEM", "cannot allocate memory"},
-	{13, "EACCES", "permission denied"},
-	{14, "EFAULT", "bad address"},
-	{15, "ENOTBLK", "block device required"},
-	{16, "EBUSY", "resource busy"},
-	{17, "EEXIST", "file exists"},
-	{18, "EXDEV", "cross-device link"},
-	{19, "ENODEV", "operation not supported by device"},
-	{20, "ENOTDIR", "not a directory"},
-	{21, "EISDIR", "is a directory"},
-	{22, "EINVAL", "invalid argument"},
-	{23, "ENFILE", "too many open files in system"},
-	{24, "EMFILE", "too many open files"},
-	{25, "ENOTTY", "inappropriate ioctl for device"},
-	{26, "ETXTBSY", "text file busy"},
-	{27, "EFBIG", "file too large"},
-	{28, "ENOSPC", "no space left on device"},
-	{29, "ESPIPE", "illegal seek"},
-	{30, "EROFS", "read-only file system"},
-	{31, "EMLINK", "too many links"},
-	{32, "EPIPE", "broken pipe"},
-	{33, "EDOM", "numerical argument out of domain"},
-	{34, "ERANGE", "result too large"},
-	{35, "EAGAIN", "resource temporarily unavailable"},
-	{36, "EINPROGRESS", "operation now in progress"},
-	{37, "EALREADY", "operation already in progress"},
-	{38, "ENOTSOCK", "socket operation on non-socket"},
-	{39, "EDESTADDRREQ", "destination address required"},
-	{40, "EMSGSIZE", "message too long"},
-	{41, "EPROTOTYPE", "protocol wrong type for socket"},
-	{42, "ENOPROTOOPT", "protocol not available"},
-	{43, "EPROTONOSUPPORT", "protocol not supported"},
-	{44, "ESOCKTNOSUPPORT", "socket type not supported"},
-	{45, "ENOTSUP", "operation not supported"},
-	{46, "EPFNOSUPPORT", "protocol family not supported"},
-	{47, "EAFNOSUPPORT", "address family not supported by protocol family"},
-	{48, "EADDRINUSE", "address already in use"},
-	{49, "EADDRNOTAVAIL", "can't assign requested address"},
-	{50, "ENETDOWN", "network is down"},
-	{51, "ENETUNREACH", "network is unreachable"},
-	{52, "ENETRESET", "network dropped connection on reset"},
-	{53, "ECONNABORTED", "software caused connection abort"},
-	{54, "ECONNRESET", "connection reset by peer"},
-	{55, "ENOBUFS", "no buffer space available"},
-	{56, "EISCONN", "socket is already connected"},
-	{57, "ENOTCONN", "socket is not connected"},
-	{58, "ESHUTDOWN", "can't send after socket shutdown"},
-	{59, "ETOOMANYREFS", "too many references: can't splice"},
-	{60, "ETIMEDOUT", "operation timed out"},
-	{61, "ECONNREFUSED", "connection refused"},
-	{62, "ELOOP", "too many levels of symbolic links"},
-	{63, "ENAMETOOLONG", "file name too long"},
-	{64, "EHOSTDOWN", "host is down"},
-	{65, "EHOSTUNREACH", "no route to host"},
-	{66, "ENOTEMPTY", "directory not empty"},
-	{67, "EPROCLIM", "too many processes"},
-	{68, "EUSERS", "too many users"},
-	{69, "EDQUOT", "disc quota exceeded"},
-	{70, "ESTALE", "stale NFS file handle"},
-	{71, "EREMOTE", "too many levels of remote in path"},
-	{72, "EBADRPC", "RPC struct is bad"},
-	{73, "ERPCMISMATCH", "RPC version wrong"},
-	{74, "EPROGUNAVAIL", "RPC prog. not avail"},
-	{75, "EPROGMISMATCH", "program version wrong"},
-	{76, "EPROCUNAVAIL", "bad procedure for program"},
-	{77, "ENOLCK", "no locks available"},
-	{78, "ENOSYS", "function not implemented"},
-	{79, "EFTYPE", "inappropriate file type or format"},
-	{80, "EAUTH", "authentication error"},
-	{81, "ENEEDAUTH", "need authenticator"},
-	{82, "EPWROFF", "device power is off"},
-	{83, "EDEVERR", "device error"},
-	{84, "EOVERFLOW", "value too large to be stored in data type"},
-	{85, "EBADEXEC", "bad executable (or shared library)"},
-	{86, "EBADARCH", "bad CPU type in executable"},
-	{87, "ESHLIBVERS", "shared library version mismatch"},
-	{88, "EBADMACHO", "malformed Mach-o file"},
-	{89, "ECANCELED", "operation canceled"},
-	{90, "EIDRM", "identifier removed"},
-	{91, "ENOMSG", "no message of desired type"},
-	{92, "EILSEQ", "illegal byte sequence"},
-	{93, "ENOATTR", "attribute not found"},
-	{94, "EBADMSG", "bad message"},
-	{95, "EMULTIHOP", "EMULTIHOP (Reserved)"},
-	{96, "ENODATA", "no message available on STREAM"},
-	{97, "ENOLINK", "ENOLINK (Reserved)"},
-	{98, "ENOSR", "no STREAM resources"},
-	{99, "ENOSTR", "not a STREAM"},
-	{100, "EPROTO", "protocol error"},
-	{101, "ETIME", "STREAM ioctl timeout"},
-	{102, "EOPNOTSUPP", "operation not supported on socket"},
-	{103, "ENOPOLICY", "policy not found"},
-	{104, "ENOTRECOVERABLE", "state not recoverable"},
-	{105, "EOWNERDEAD", "previous owner died"},
-	{106, "EQFULL", "interface output queue is full"},
-}
-
-// Signal table
-var signalList = [...]struct {
-	num  syscall.Signal
-	name string
-	desc string
-}{
-	{1, "SIGHUP", "hangup"},
-	{2, "SIGINT", "interrupt"},
-	{3, "SIGQUIT", "quit"},
-	{4, "SIGILL", "illegal instruction"},
-	{5, "SIGTRAP", "trace/BPT trap"},
-	{6, "SIGABRT", "abort trap"},
-	{7, "SIGEMT", "EMT trap"},
-	{8, "SIGFPE", "floating point exception"},
-	{9, "SIGKILL", "killed"},
-	{10, "SIGBUS", "bus error"},
-	{11, "SIGSEGV", "segmentation fault"},
-	{12, "SIGSYS", "bad system call"},
-	{13, "SIGPIPE", "broken pipe"},
-	{14, "SIGALRM", "alarm clock"},
-	{15, "SIGTERM", "terminated"},
-	{16, "SIGURG", "urgent I/O condition"},
-	{17, "SIGSTOP", "suspended (signal)"},
-	{18, "SIGTSTP", "suspended"},
-	{19, "SIGCONT", "continued"},
-	{20, "SIGCHLD", "child exited"},
-	{21, "SIGTTIN", "stopped (tty input)"},
-	{22, "SIGTTOU", "stopped (tty output)"},
-	{23, "SIGIO", "I/O possible"},
-	{24, "SIGXCPU", "cputime limit exceeded"},
-	{25, "SIGXFSZ", "filesize limit exceeded"},
-	{26, "SIGVTALRM", "virtual timer expired"},
-	{27, "SIGPROF", "profiling timer expired"},
-	{28, "SIGWINCH", "window size changes"},
-	{29, "SIGINFO", "information request"},
-	{30, "SIGUSR1", "user defined signal 1"},
-	{31, "SIGUSR2", "user defined signal 2"},
-}
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_arm.go b/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_arm.go
deleted file mode 100644
index e748cb11057..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zerrors_darwin_arm.go
+++ /dev/null
@@ -1,1789 +0,0 @@
-// mkerrors.sh
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build arm && darwin
-// +build arm,darwin
-
-// Code generated by cmd/cgo -godefs; DO NOT EDIT.
-// cgo -godefs -- _const.go
-
-package unix
-
-import "syscall"
-
-const (
-	AF_APPLETALK                      = 0x10
-	AF_CCITT                          = 0xa
-	AF_CHAOS                          = 0x5
-	AF_CNT                            = 0x15
-	AF_COIP                           = 0x14
-	AF_DATAKIT                        = 0x9
-	AF_DECnet                         = 0xc
-	AF_DLI                            = 0xd
-	AF_E164                           = 0x1c
-	AF_ECMA                           = 0x8
-	AF_HYLINK                         = 0xf
-	AF_IEEE80211                      = 0x25
-	AF_IMPLINK                        = 0x3
-	AF_INET                           = 0x2
-	AF_INET6                          = 0x1e
-	AF_IPX                            = 0x17
-	AF_ISDN                           = 0x1c
-	AF_ISO                            = 0x7
-	AF_LAT                            = 0xe
-	AF_LINK                           = 0x12
-	AF_LOCAL                          = 0x1
-	AF_MAX                            = 0x28
-	AF_NATM                           = 0x1f
-	AF_NDRV                           = 0x1b
-	AF_NETBIOS                        = 0x21
-	AF_NS                             = 0x6
-	AF_OSI                            = 0x7
-	AF_PPP                            = 0x22
-	AF_PUP                            = 0x4
-	AF_RESERVED_36                    = 0x24
-	AF_ROUTE                          = 0x11
-	AF_SIP                            = 0x18
-	AF_SNA                            = 0xb
-	AF_SYSTEM                         = 0x20
-	AF_SYS_CONTROL                    = 0x2
-	AF_UNIX                           = 0x1
-	AF_UNSPEC                         = 0x0
-	AF_UTUN                           = 0x26
-	ALTWERASE                         = 0x200
-	ATTR_BIT_MAP_COUNT                = 0x5
-	ATTR_CMN_ACCESSMASK               = 0x20000
-	ATTR_CMN_ACCTIME                  = 0x1000
-	ATTR_CMN_ADDEDTIME                = 0x10000000
-	ATTR_CMN_BKUPTIME                 = 0x2000
-	ATTR_CMN_CHGTIME                  = 0x800
-	ATTR_CMN_CRTIME                   = 0x200
-	ATTR_CMN_DATA_PROTECT_FLAGS       = 0x40000000
-	ATTR_CMN_DEVID                    = 0x2
-	ATTR_CMN_DOCUMENT_ID              = 0x100000
-	ATTR_CMN_ERROR                    = 0x20000000
-	ATTR_CMN_EXTENDED_SECURITY        = 0x400000
-	ATTR_CMN_FILEID                   = 0x2000000
-	ATTR_CMN_FLAGS                    = 0x40000
-	ATTR_CMN_FNDRINFO                 = 0x4000
-	ATTR_CMN_FSID                     = 0x4
-	ATTR_CMN_FULLPATH                 = 0x8000000
-	ATTR_CMN_GEN_COUNT                = 0x80000
-	ATTR_CMN_GRPID                    = 0x10000
-	ATTR_CMN_GRPUUID                  = 0x1000000
-	ATTR_CMN_MODTIME                  = 0x400
-	ATTR_CMN_NAME                     = 0x1
-	ATTR_CMN_NAMEDATTRCOUNT           = 0x80000
-	ATTR_CMN_NAMEDATTRLIST            = 0x100000
-	ATTR_CMN_OBJID                    = 0x20
-	ATTR_CMN_OBJPERMANENTID           = 0x40
-	ATTR_CMN_OBJTAG                   = 0x10
-	ATTR_CMN_OBJTYPE                  = 0x8
-	ATTR_CMN_OWNERID                  = 0x8000
-	ATTR_CMN_PARENTID                 = 0x4000000
-	ATTR_CMN_PAROBJID                 = 0x80
-	ATTR_CMN_RETURNED_ATTRS           = 0x80000000
-	ATTR_CMN_SCRIPT                   = 0x100
-	ATTR_CMN_SETMASK                  = 0x41c7ff00
-	ATTR_CMN_USERACCESS               = 0x200000
-	ATTR_CMN_UUID                     = 0x800000
-	ATTR_CMN_VALIDMASK                = 0xffffffff
-	ATTR_CMN_VOLSETMASK               = 0x6700
-	ATTR_FILE_ALLOCSIZE               = 0x4
-	ATTR_FILE_CLUMPSIZE               = 0x10
-	ATTR_FILE_DATAALLOCSIZE           = 0x400
-	ATTR_FILE_DATAEXTENTS             = 0x800
-	ATTR_FILE_DATALENGTH              = 0x200
-	ATTR_FILE_DEVTYPE                 = 0x20
-	ATTR_FILE_FILETYPE                = 0x40
-	ATTR_FILE_FORKCOUNT               = 0x80
-	ATTR_FILE_FORKLIST                = 0x100
-	ATTR_FILE_IOBLOCKSIZE             = 0x8
-	ATTR_FILE_LINKCOUNT               = 0x1
-	ATTR_FILE_RSRCALLOCSIZE           = 0x2000
-	ATTR_FILE_RSRCEXTENTS             = 0x4000
-	ATTR_FILE_RSRCLENGTH              = 0x1000
-	ATTR_FILE_SETMASK                 = 0x20
-	ATTR_FILE_TOTALSIZE               = 0x2
-	ATTR_FILE_VALIDMASK               = 0x37ff
-	ATTR_VOL_ALLOCATIONCLUMP          = 0x40
-	ATTR_VOL_ATTRIBUTES               = 0x40000000
-	ATTR_VOL_CAPABILITIES             = 0x20000
-	ATTR_VOL_DIRCOUNT                 = 0x400
-	ATTR_VOL_ENCODINGSUSED            = 0x10000
-	ATTR_VOL_FILECOUNT                = 0x200
-	ATTR_VOL_FSTYPE                   = 0x1
-	ATTR_VOL_INFO                     = 0x80000000
-	ATTR_VOL_IOBLOCKSIZE              = 0x80
-	ATTR_VOL_MAXOBJCOUNT              = 0x800
-	ATTR_VOL_MINALLOCATION            = 0x20
-	ATTR_VOL_MOUNTEDDEVICE            = 0x8000
-	ATTR_VOL_MOUNTFLAGS               = 0x4000
-	ATTR_VOL_MOUNTPOINT               = 0x1000
-	ATTR_VOL_NAME                     = 0x2000
-	ATTR_VOL_OBJCOUNT                 = 0x100
-	ATTR_VOL_QUOTA_SIZE               = 0x10000000
-	ATTR_VOL_RESERVED_SIZE            = 0x20000000
-	ATTR_VOL_SETMASK                  = 0x80002000
-	ATTR_VOL_SIGNATURE                = 0x2
-	ATTR_VOL_SIZE                     = 0x4
-	ATTR_VOL_SPACEAVAIL               = 0x10
-	ATTR_VOL_SPACEFREE                = 0x8
-	ATTR_VOL_UUID                     = 0x40000
-	ATTR_VOL_VALIDMASK                = 0xf007ffff
-	B0                                = 0x0
-	B110                              = 0x6e
-	B115200                           = 0x1c200
-	B1200                             = 0x4b0
-	B134                              = 0x86
-	B14400                            = 0x3840
-	B150                              = 0x96
-	B1800                             = 0x708
-	B19200                            = 0x4b00
-	B200                              = 0xc8
-	B230400                           = 0x38400
-	B2400                             = 0x960
-	B28800                            = 0x7080
-	B300                              = 0x12c
-	B38400                            = 0x9600
-	B4800                             = 0x12c0
-	B50                               = 0x32
-	B57600                            = 0xe100
-	B600                              = 0x258
-	B7200                             = 0x1c20
-	B75                               = 0x4b
-	B76800                            = 0x12c00
-	B9600                             = 0x2580
-	BIOCFLUSH                         = 0x20004268
-	BIOCGBLEN                         = 0x40044266
-	BIOCGDLT                          = 0x4004426a
-	BIOCGDLTLIST                      = 0xc00c4279
-	BIOCGETIF                         = 0x4020426b
-	BIOCGHDRCMPLT                     = 0x40044274
-	BIOCGRSIG                         = 0x40044272
-	BIOCGRTIMEOUT                     = 0x4010426e
-	BIOCGSEESENT                      = 0x40044276
-	BIOCGSTATS                        = 0x4008426f
-	BIOCIMMEDIATE                     = 0x80044270
-	BIOCPROMISC                       = 0x20004269
-	BIOCSBLEN                         = 0xc0044266
-	BIOCSDLT                          = 0x80044278
-	BIOCSETF                          = 0x80104267
-	BIOCSETFNR                        = 0x8010427e
-	BIOCSETIF                         = 0x8020426c
-	BIOCSHDRCMPLT                     = 0x80044275
-	BIOCSRSIG                         = 0x80044273
-	BIOCSRTIMEOUT                     = 0x8010426d
-	BIOCSSEESENT                      = 0x80044277
-	BIOCVERSION                       = 0x40044271
-	BPF_A                             = 0x10
-	BPF_ABS                           = 0x20
-	BPF_ADD                           = 0x0
-	BPF_ALIGNMENT                     = 0x4
-	BPF_ALU                           = 0x4
-	BPF_AND                           = 0x50
-	BPF_B                             = 0x10
-	BPF_DIV                           = 0x30
-	BPF_H                             = 0x8
-	BPF_IMM                           = 0x0
-	BPF_IND                           = 0x40
-	BPF_JA                            = 0x0
-	BPF_JEQ                           = 0x10
-	BPF_JGE                           = 0x30
-	BPF_JGT                           = 0x20
-	BPF_JMP                           = 0x5
-	BPF_JSET                          = 0x40
-	BPF_K                             = 0x0
-	BPF_LD                            = 0x0
-	BPF_LDX                           = 0x1
-	BPF_LEN                           = 0x80
-	BPF_LSH                           = 0x60
-	BPF_MAJOR_VERSION                 = 0x1
-	BPF_MAXBUFSIZE                    = 0x80000
-	BPF_MAXINSNS                      = 0x200
-	BPF_MEM                           = 0x60
-	BPF_MEMWORDS                      = 0x10
-	BPF_MINBUFSIZE                    = 0x20
-	BPF_MINOR_VERSION                 = 0x1
-	BPF_MISC                          = 0x7
-	BPF_MSH                           = 0xa0
-	BPF_MUL                           = 0x20
-	BPF_NEG                           = 0x80
-	BPF_OR                            = 0x40
-	BPF_RELEASE                       = 0x30bb6
-	BPF_RET                           = 0x6
-	BPF_RSH                           = 0x70
-	BPF_ST                            = 0x2
-	BPF_STX                           = 0x3
-	BPF_SUB                           = 0x10
-	BPF_TAX                           = 0x0
-	BPF_TXA                           = 0x80
-	BPF_W                             = 0x0
-	BPF_X                             = 0x8
-	BRKINT                            = 0x2
-	BS0                               = 0x0
-	BS1                               = 0x8000
-	BSDLY                             = 0x8000
-	CFLUSH                            = 0xf
-	CLOCAL                            = 0x8000
-	CLOCK_MONOTONIC                   = 0x6
-	CLOCK_MONOTONIC_RAW               = 0x4
-	CLOCK_MONOTONIC_RAW_APPROX        = 0x5
-	CLOCK_PROCESS_CPUTIME_ID          = 0xc
-	CLOCK_REALTIME                    = 0x0
-	CLOCK_THREAD_CPUTIME_ID           = 0x10
-	CLOCK_UPTIME_RAW                  = 0x8
-	CLOCK_UPTIME_RAW_APPROX           = 0x9
-	CLONE_NOFOLLOW                    = 0x1
-	CLONE_NOOWNERCOPY                 = 0x2
-	CR0                               = 0x0
-	CR1                               = 0x1000
-	CR2                               = 0x2000
-	CR3                               = 0x3000
-	CRDLY                             = 0x3000
-	CREAD                             = 0x800
-	CRTSCTS                           = 0x30000
-	CS5                               = 0x0
-	CS6                               = 0x100
-	CS7                               = 0x200
-	CS8                               = 0x300
-	CSIZE                             = 0x300
-	CSTART                            = 0x11
-	CSTATUS                           = 0x14
-	CSTOP                             = 0x13
-	CSTOPB                            = 0x400
-	CSUSP                             = 0x1a
-	CTLIOCGINFO                       = 0xc0644e03
-	CTL_HW                            = 0x6
-	CTL_KERN                          = 0x1
-	CTL_MAXNAME                       = 0xc
-	CTL_NET                           = 0x4
-	DLT_A429                          = 0xb8
-	DLT_A653_ICM                      = 0xb9
-	DLT_AIRONET_HEADER                = 0x78
-	DLT_AOS                           = 0xde
-	DLT_APPLE_IP_OVER_IEEE1394        = 0x8a
-	DLT_ARCNET                        = 0x7
-	DLT_ARCNET_LINUX                  = 0x81
-	DLT_ATM_CLIP                      = 0x13
-	DLT_ATM_RFC1483                   = 0xb
-	DLT_AURORA                        = 0x7e
-	DLT_AX25                          = 0x3
-	DLT_AX25_KISS                     = 0xca
-	DLT_BACNET_MS_TP                  = 0xa5
-	DLT_BLUETOOTH_HCI_H4              = 0xbb
-	DLT_BLUETOOTH_HCI_H4_WITH_PHDR    = 0xc9
-	DLT_CAN20B                        = 0xbe
-	DLT_CAN_SOCKETCAN                 = 0xe3
-	DLT_CHAOS                         = 0x5
-	DLT_CHDLC                         = 0x68
-	DLT_CISCO_IOS                     = 0x76
-	DLT_C_HDLC                        = 0x68
-	DLT_C_HDLC_WITH_DIR               = 0xcd
-	DLT_DBUS                          = 0xe7
-	DLT_DECT                          = 0xdd
-	DLT_DOCSIS                        = 0x8f
-	DLT_DVB_CI                        = 0xeb
-	DLT_ECONET                        = 0x73
-	DLT_EN10MB                        = 0x1
-	DLT_EN3MB                         = 0x2
-	DLT_ENC                           = 0x6d
-	DLT_ERF                           = 0xc5
-	DLT_ERF_ETH                       = 0xaf
-	DLT_ERF_POS                       = 0xb0
-	DLT_FC_2                          = 0xe0
-	DLT_FC_2_WITH_FRAME_DELIMS        = 0xe1
-	DLT_FDDI                          = 0xa
-	DLT_FLEXRAY                       = 0xd2
-	DLT_FRELAY                        = 0x6b
-	DLT_FRELAY_WITH_DIR               = 0xce
-	DLT_GCOM_SERIAL                   = 0xad
-	DLT_GCOM_T1E1                     = 0xac
-	DLT_GPF_F                         = 0xab
-	DLT_GPF_T                         = 0xaa
-	DLT_GPRS_LLC                      = 0xa9
-	DLT_GSMTAP_ABIS                   = 0xda
-	DLT_GSMTAP_UM                     = 0xd9
-	DLT_HHDLC                         = 0x79
-	DLT_IBM_SN                        = 0x92
-	DLT_IBM_SP                        = 0x91
-	DLT_IEEE802                       = 0x6
-	DLT_IEEE802_11                    = 0x69
-	DLT_IEEE802_11_RADIO              = 0x7f
-	DLT_IEEE802_11_RADIO_AVS          = 0xa3
-	DLT_IEEE802_15_4                  = 0xc3
-	DLT_IEEE802_15_4_LINUX            = 0xbf
-	DLT_IEEE802_15_4_NOFCS            = 0xe6
-	DLT_IEEE802_15_4_NONASK_PHY       = 0xd7
-	DLT_IEEE802_16_MAC_CPS            = 0xbc
-	DLT_IEEE802_16_MAC_CPS_RADIO      = 0xc1
-	DLT_IPFILTER                      = 0x74
-	DLT_IPMB                          = 0xc7
-	DLT_IPMB_LINUX                    = 0xd1
-	DLT_IPNET                         = 0xe2
-	DLT_IPOIB                         = 0xf2
-	DLT_IPV4                          = 0xe4
-	DLT_IPV6                          = 0xe5
-	DLT_IP_OVER_FC                    = 0x7a
-	DLT_JUNIPER_ATM1                  = 0x89
-	DLT_JUNIPER_ATM2                  = 0x87
-	DLT_JUNIPER_ATM_CEMIC             = 0xee
-	DLT_JUNIPER_CHDLC                 = 0xb5
-	DLT_JUNIPER_ES                    = 0x84
-	DLT_JUNIPER_ETHER                 = 0xb2
-	DLT_JUNIPER_FIBRECHANNEL          = 0xea
-	DLT_JUNIPER_FRELAY                = 0xb4
-	DLT_JUNIPER_GGSN                  = 0x85
-	DLT_JUNIPER_ISM                   = 0xc2
-	DLT_JUNIPER_MFR                   = 0x86
-	DLT_JUNIPER_MLFR                  = 0x83
-	DLT_JUNIPER_MLPPP                 = 0x82
-	DLT_JUNIPER_MONITOR               = 0xa4
-	DLT_JUNIPER_PIC_PEER              = 0xae
-	DLT_JUNIPER_PPP                   = 0xb3
-	DLT_JUNIPER_PPPOE                 = 0xa7
-	DLT_JUNIPER_PPPOE_ATM             = 0xa8
-	DLT_JUNIPER_SERVICES              = 0x88
-	DLT_JUNIPER_SRX_E2E               = 0xe9
-	DLT_JUNIPER_ST                    = 0xc8
-	DLT_JUNIPER_VP                    = 0xb7
-	DLT_JUNIPER_VS                    = 0xe8
-	DLT_LAPB_WITH_DIR                 = 0xcf
-	DLT_LAPD                          = 0xcb
-	DLT_LIN                           = 0xd4
-	DLT_LINUX_EVDEV                   = 0xd8
-	DLT_LINUX_IRDA                    = 0x90
-	DLT_LINUX_LAPD                    = 0xb1
-	DLT_LINUX_PPP_WITHDIRECTION       = 0xa6
-	DLT_LINUX_SLL                     = 0x71
-	DLT_LOOP                          = 0x6c
-	DLT_LTALK                         = 0x72
-	DLT_MATCHING_MAX                  = 0xf5
-	DLT_MATCHING_MIN                  = 0x68
-	DLT_MFR                           = 0xb6
-	DLT_MOST                          = 0xd3
-	DLT_MPEG_2_TS                     = 0xf3
-	DLT_MPLS                          = 0xdb
-	DLT_MTP2                          = 0x8c
-	DLT_MTP2_WITH_PHDR                = 0x8b
-	DLT_MTP3                          = 0x8d
-	DLT_MUX27010                      = 0xec
-	DLT_NETANALYZER                   = 0xf0
-	DLT_NETANALYZER_TRANSPARENT       = 0xf1
-	DLT_NFC_LLCP                      = 0xf5
-	DLT_NFLOG                         = 0xef
-	DLT_NG40                          = 0xf4
-	DLT_NULL                          = 0x0
-	DLT_PCI_EXP                       = 0x7d
-	DLT_PFLOG                         = 0x75
-	DLT_PFSYNC                        = 0x12
-	DLT_PPI                           = 0xc0
-	DLT_PPP                           = 0x9
-	DLT_PPP_BSDOS                     = 0x10
-	DLT_PPP_ETHER                     = 0x33
-	DLT_PPP_PPPD                      = 0xa6
-	DLT_PPP_SERIAL                    = 0x32
-	DLT_PPP_WITH_DIR                  = 0xcc
-	DLT_PPP_WITH_DIRECTION            = 0xa6
-	DLT_PRISM_HEADER                  = 0x77
-	DLT_PRONET                        = 0x4
-	DLT_RAIF1                         = 0xc6
-	DLT_RAW                           = 0xc
-	DLT_RIO                           = 0x7c
-	DLT_SCCP                          = 0x8e
-	DLT_SITA                          = 0xc4
-	DLT_SLIP                          = 0x8
-	DLT_SLIP_BSDOS                    = 0xf
-	DLT_STANAG_5066_D_PDU             = 0xed
-	DLT_SUNATM                        = 0x7b
-	DLT_SYMANTEC_FIREWALL             = 0x63
-	DLT_TZSP                          = 0x80
-	DLT_USB                           = 0xba
-	DLT_USB_LINUX                     = 0xbd
-	DLT_USB_LINUX_MMAPPED             = 0xdc
-	DLT_USER0                         = 0x93
-	DLT_USER1                         = 0x94
-	DLT_USER10                        = 0x9d
-	DLT_USER11                        = 0x9e
-	DLT_USER12                        = 0x9f
-	DLT_USER13                        = 0xa0
-	DLT_USER14                        = 0xa1
-	DLT_USER15                        = 0xa2
-	DLT_USER2                         = 0x95
-	DLT_USER3                         = 0x96
-	DLT_USER4                         = 0x97
-	DLT_USER5                         = 0x98
-	DLT_USER6                         = 0x99
-	DLT_USER7                         = 0x9a
-	DLT_USER8                         = 0x9b
-	DLT_USER9                         = 0x9c
-	DLT_WIHART                        = 0xdf
-	DLT_X2E_SERIAL                    = 0xd5
-	DLT_X2E_XORAYA                    = 0xd6
-	DT_BLK                            = 0x6
-	DT_CHR                            = 0x2
-	DT_DIR                            = 0x4
-	DT_FIFO                           = 0x1
-	DT_LNK                            = 0xa
-	DT_REG                            = 0x8
-	DT_SOCK                           = 0xc
-	DT_UNKNOWN                        = 0x0
-	DT_WHT                            = 0xe
-	ECHO                              = 0x8
-	ECHOCTL                           = 0x40
-	ECHOE                             = 0x2
-	ECHOK                             = 0x4
-	ECHOKE                            = 0x1
-	ECHONL                            = 0x10
-	ECHOPRT                           = 0x20
-	EVFILT_AIO                        = -0x3
-	EVFILT_EXCEPT                     = -0xf
-	EVFILT_FS                         = -0x9
-	EVFILT_MACHPORT                   = -0x8
-	EVFILT_PROC                       = -0x5
-	EVFILT_READ                       = -0x1
-	EVFILT_SIGNAL                     = -0x6
-	EVFILT_SYSCOUNT                   = 0xf
-	EVFILT_THREADMARKER               = 0xf
-	EVFILT_TIMER                      = -0x7
-	EVFILT_USER                       = -0xa
-	EVFILT_VM                         = -0xc
-	EVFILT_VNODE                      = -0x4
-	EVFILT_WRITE                      = -0x2
-	EV_ADD                            = 0x1
-	EV_CLEAR                          = 0x20
-	EV_DELETE                         = 0x2
-	EV_DISABLE                        = 0x8
-	EV_DISPATCH                       = 0x80
-	EV_DISPATCH2                      = 0x180
-	EV_ENABLE                         = 0x4
-	EV_EOF                            = 0x8000
-	EV_ERROR                          = 0x4000
-	EV_FLAG0                          = 0x1000
-	EV_FLAG1                          = 0x2000
-	EV_ONESHOT                        = 0x10
-	EV_OOBAND                         = 0x2000
-	EV_POLL                           = 0x1000
-	EV_RECEIPT                        = 0x40
-	EV_SYSFLAGS                       = 0xf000
-	EV_UDATA_SPECIFIC                 = 0x100
-	EV_VANISHED                       = 0x200
-	EXTA                              = 0x4b00
-	EXTB                              = 0x9600
-	EXTPROC                           = 0x800
-	FD_CLOEXEC                        = 0x1
-	FD_SETSIZE                        = 0x400
-	FF0                               = 0x0
-	FF1                               = 0x4000
-	FFDLY                             = 0x4000
-	FLUSHO                            = 0x800000
-	FSOPT_ATTR_CMN_EXTENDED           = 0x20
-	FSOPT_NOFOLLOW                    = 0x1
-	FSOPT_NOINMEMUPDATE               = 0x2
-	FSOPT_PACK_INVAL_ATTRS            = 0x8
-	FSOPT_REPORT_FULLSIZE             = 0x4
-	F_ADDFILESIGS                     = 0x3d
-	F_ADDFILESIGS_FOR_DYLD_SIM        = 0x53
-	F_ADDFILESIGS_RETURN              = 0x61
-	F_ADDSIGS                         = 0x3b
-	F_ALLOCATEALL                     = 0x4
-	F_ALLOCATECONTIG                  = 0x2
-	F_BARRIERFSYNC                    = 0x55
-	F_CHECK_LV                        = 0x62
-	F_CHKCLEAN                        = 0x29
-	F_DUPFD                           = 0x0
-	F_DUPFD_CLOEXEC                   = 0x43
-	F_FINDSIGS                        = 0x4e
-	F_FLUSH_DATA                      = 0x28
-	F_FREEZE_FS                       = 0x35
-	F_FULLFSYNC                       = 0x33
-	F_GETCODEDIR                      = 0x48
-	F_GETFD                           = 0x1
-	F_GETFL                           = 0x3
-	F_GETLK                           = 0x7
-	F_GETLKPID                        = 0x42
-	F_GETNOSIGPIPE                    = 0x4a
-	F_GETOWN                          = 0x5
-	F_GETPATH                         = 0x32
-	F_GETPATH_MTMINFO                 = 0x47
-	F_GETPROTECTIONCLASS              = 0x3f
-	F_GETPROTECTIONLEVEL              = 0x4d
-	F_GLOBAL_NOCACHE                  = 0x37
-	F_LOG2PHYS                        = 0x31
-	F_LOG2PHYS_EXT                    = 0x41
-	F_NOCACHE                         = 0x30
-	F_NODIRECT                        = 0x3e
-	F_OK                              = 0x0
-	F_PATHPKG_CHECK                   = 0x34
-	F_PEOFPOSMODE                     = 0x3
-	F_PREALLOCATE                     = 0x2a
-	F_PUNCHHOLE                       = 0x63
-	F_RDADVISE                        = 0x2c
-	F_RDAHEAD                         = 0x2d
-	F_RDLCK                           = 0x1
-	F_SETBACKINGSTORE                 = 0x46
-	F_SETFD                           = 0x2
-	F_SETFL                           = 0x4
-	F_SETLK                           = 0x8
-	F_SETLKW                          = 0x9
-	F_SETLKWTIMEOUT                   = 0xa
-	F_SETNOSIGPIPE                    = 0x49
-	F_SETOWN                          = 0x6
-	F_SETPROTECTIONCLASS              = 0x40
-	F_SETSIZE                         = 0x2b
-	F_SINGLE_WRITER                   = 0x4c
-	F_THAW_FS                         = 0x36
-	F_TRANSCODEKEY                    = 0x4b
-	F_TRIM_ACTIVE_FILE                = 0x64
-	F_UNLCK                           = 0x2
-	F_VOLPOSMODE                      = 0x4
-	F_WRLCK                           = 0x3
-	HUPCL                             = 0x4000
-	HW_MACHINE                        = 0x1
-	ICANON                            = 0x100
-	ICMP6_FILTER                      = 0x12
-	ICRNL                             = 0x100
-	IEXTEN                            = 0x400
-	IFF_ALLMULTI                      = 0x200
-	IFF_ALTPHYS                       = 0x4000
-	IFF_BROADCAST                     = 0x2
-	IFF_DEBUG                         = 0x4
-	IFF_LINK0                         = 0x1000
-	IFF_LINK1                         = 0x2000
-	IFF_LINK2                         = 0x4000
-	IFF_LOOPBACK                      = 0x8
-	IFF_MULTICAST                     = 0x8000
-	IFF_NOARP                         = 0x80
-	IFF_NOTRAILERS                    = 0x20
-	IFF_OACTIVE                       = 0x400
-	IFF_POINTOPOINT                   = 0x10
-	IFF_PROMISC                       = 0x100
-	IFF_RUNNING                       = 0x40
-	IFF_SIMPLEX                       = 0x800
-	IFF_UP                            = 0x1
-	IFNAMSIZ                          = 0x10
-	IFT_1822                          = 0x2
-	IFT_AAL5                          = 0x31
-	IFT_ARCNET                        = 0x23
-	IFT_ARCNETPLUS                    = 0x24
-	IFT_ATM                           = 0x25
-	IFT_BRIDGE                        = 0xd1
-	IFT_CARP                          = 0xf8
-	IFT_CELLULAR                      = 0xff
-	IFT_CEPT                          = 0x13
-	IFT_DS3                           = 0x1e
-	IFT_ENC                           = 0xf4
-	IFT_EON                           = 0x19
-	IFT_ETHER                         = 0x6
-	IFT_FAITH                         = 0x38
-	IFT_FDDI                          = 0xf
-	IFT_FRELAY                        = 0x20
-	IFT_FRELAYDCE                     = 0x2c
-	IFT_GIF                           = 0x37
-	IFT_HDH1822                       = 0x3
-	IFT_HIPPI                         = 0x2f
-	IFT_HSSI                          = 0x2e
-	IFT_HY                            = 0xe
-	IFT_IEEE1394                      = 0x90
-	IFT_IEEE8023ADLAG                 = 0x88
-	IFT_ISDNBASIC                     = 0x14
-	IFT_ISDNPRIMARY                   = 0x15
-	IFT_ISO88022LLC                   = 0x29
-	IFT_ISO88023                      = 0x7
-	IFT_ISO88024                      = 0x8
-	IFT_ISO88025                      = 0x9
-	IFT_ISO88026                      = 0xa
-	IFT_L2VLAN                        = 0x87
-	IFT_LAPB                          = 0x10
-	IFT_LOCALTALK                     = 0x2a
-	IFT_LOOP                          = 0x18
-	IFT_MIOX25                        = 0x26
-	IFT_MODEM                         = 0x30
-	IFT_NSIP                          = 0x1b
-	IFT_OTHER                         = 0x1
-	IFT_P10                           = 0xc
-	IFT_P80                           = 0xd
-	IFT_PARA                          = 0x22
-	IFT_PDP                           = 0xff
-	IFT_PFLOG                         = 0xf5
-	IFT_PFSYNC                        = 0xf6
-	IFT_PKTAP                         = 0xfe
-	IFT_PPP                           = 0x17
-	IFT_PROPMUX                       = 0x36
-	IFT_PROPVIRTUAL                   = 0x35
-	IFT_PTPSERIAL                     = 0x16
-	IFT_RS232                         = 0x21
-	IFT_SDLC                          = 0x11
-	IFT_SIP                           = 0x1f
-	IFT_SLIP                          = 0x1c
-	IFT_SMDSDXI                       = 0x2b
-	IFT_SMDSICIP                      = 0x34
-	IFT_SONET                         = 0x27
-	IFT_SONETPATH                     = 0x32
-	IFT_SONETVT                       = 0x33
-	IFT_STARLAN                       = 0xb
-	IFT_STF                           = 0x39
-	IFT_T1                            = 0x12
-	IFT_ULTRA                         = 0x1d
-	IFT_V35                           = 0x2d
-	IFT_X25                           = 0x5
-	IFT_X25DDN                        = 0x4
-	IFT_X25PLE                        = 0x28
-	IFT_XETHER                        = 0x1a
-	IGNBRK                            = 0x1
-	IGNCR                             = 0x80
-	IGNPAR                            = 0x4
-	IMAXBEL                           = 0x2000
-	INLCR                             = 0x40
-	INPCK                             = 0x10
-	IN_CLASSA_HOST                    = 0xffffff
-	IN_CLASSA_MAX                     = 0x80
-	IN_CLASSA_NET                     = 0xff000000
-	IN_CLASSA_NSHIFT                  = 0x18
-	IN_CLASSB_HOST                    = 0xffff
-	IN_CLASSB_MAX                     = 0x10000
-	IN_CLASSB_NET                     = 0xffff0000
-	IN_CLASSB_NSHIFT                  = 0x10
-	IN_CLASSC_HOST                    = 0xff
-	IN_CLASSC_NET                     = 0xffffff00
-	IN_CLASSC_NSHIFT                  = 0x8
-	IN_CLASSD_HOST                    = 0xfffffff
-	IN_CLASSD_NET                     = 0xf0000000
-	IN_CLASSD_NSHIFT                  = 0x1c
-	IN_LINKLOCALNETNUM                = 0xa9fe0000
-	IN_LOOPBACKNET                    = 0x7f
-	IPPROTO_3PC                       = 0x22
-	IPPROTO_ADFS                      = 0x44
-	IPPROTO_AH                        = 0x33
-	IPPROTO_AHIP                      = 0x3d
-	IPPROTO_APES                      = 0x63
-	IPPROTO_ARGUS                     = 0xd
-	IPPROTO_AX25                      = 0x5d
-	IPPROTO_BHA                       = 0x31
-	IPPROTO_BLT                       = 0x1e
-	IPPROTO_BRSATMON                  = 0x4c
-	IPPROTO_CFTP                      = 0x3e
-	IPPROTO_CHAOS                     = 0x10
-	IPPROTO_CMTP                      = 0x26
-	IPPROTO_CPHB                      = 0x49
-	IPPROTO_CPNX                      = 0x48
-	IPPROTO_DDP                       = 0x25
-	IPPROTO_DGP                       = 0x56
-	IPPROTO_DIVERT                    = 0xfe
-	IPPROTO_DONE                      = 0x101
-	IPPROTO_DSTOPTS                   = 0x3c
-	IPPROTO_EGP                       = 0x8
-	IPPROTO_EMCON                     = 0xe
-	IPPROTO_ENCAP                     = 0x62
-	IPPROTO_EON                       = 0x50
-	IPPROTO_ESP                       = 0x32
-	IPPROTO_ETHERIP                   = 0x61
-	IPPROTO_FRAGMENT                  = 0x2c
-	IPPROTO_GGP                       = 0x3
-	IPPROTO_GMTP                      = 0x64
-	IPPROTO_GRE                       = 0x2f
-	IPPROTO_HELLO                     = 0x3f
-	IPPROTO_HMP                       = 0x14
-	IPPROTO_HOPOPTS                   = 0x0
-	IPPROTO_ICMP                      = 0x1
-	IPPROTO_ICMPV6                    = 0x3a
-	IPPROTO_IDP                       = 0x16
-	IPPROTO_IDPR                      = 0x23
-	IPPROTO_IDRP                      = 0x2d
-	IPPROTO_IGMP                      = 0x2
-	IPPROTO_IGP                       = 0x55
-	IPPROTO_IGRP                      = 0x58
-	IPPROTO_IL                        = 0x28
-	IPPROTO_INLSP                     = 0x34
-	IPPROTO_INP                       = 0x20
-	IPPROTO_IP                        = 0x0
-	IPPROTO_IPCOMP                    = 0x6c
-	IPPROTO_IPCV                      = 0x47
-	IPPROTO_IPEIP                     = 0x5e
-	IPPROTO_IPIP                      = 0x4
-	IPPROTO_IPPC                      = 0x43
-	IPPROTO_IPV4                      = 0x4
-	IPPROTO_IPV6                      = 0x29
-	IPPROTO_IRTP                      = 0x1c
-	IPPROTO_KRYPTOLAN                 = 0x41
-	IPPROTO_LARP                      = 0x5b
-	IPPROTO_LEAF1                     = 0x19
-	IPPROTO_LEAF2                     = 0x1a
-	IPPROTO_MAX                       = 0x100
-	IPPROTO_MAXID                     = 0x34
-	IPPROTO_MEAS                      = 0x13
-	IPPROTO_MHRP                      = 0x30
-	IPPROTO_MICP                      = 0x5f
-	IPPROTO_MTP                       = 0x5c
-	IPPROTO_MUX                       = 0x12
-	IPPROTO_ND                        = 0x4d
-	IPPROTO_NHRP                      = 0x36
-	IPPROTO_NONE                      = 0x3b
-	IPPROTO_NSP                       = 0x1f
-	IPPROTO_NVPII                     = 0xb
-	IPPROTO_OSPFIGP                   = 0x59
-	IPPROTO_PGM                       = 0x71
-	IPPROTO_PIGP                      = 0x9
-	IPPROTO_PIM                       = 0x67
-	IPPROTO_PRM                       = 0x15
-	IPPROTO_PUP                       = 0xc
-	IPPROTO_PVP                       = 0x4b
-	IPPROTO_RAW                       = 0xff
-	IPPROTO_RCCMON                    = 0xa
-	IPPROTO_RDP                       = 0x1b
-	IPPROTO_ROUTING                   = 0x2b
-	IPPROTO_RSVP                      = 0x2e
-	IPPROTO_RVD                       = 0x42
-	IPPROTO_SATEXPAK                  = 0x40
-	IPPROTO_SATMON                    = 0x45
-	IPPROTO_SCCSP                     = 0x60
-	IPPROTO_SCTP                      = 0x84
-	IPPROTO_SDRP                      = 0x2a
-	IPPROTO_SEP                       = 0x21
-	IPPROTO_SRPC                      = 0x5a
-	IPPROTO_ST                        = 0x7
-	IPPROTO_SVMTP                     = 0x52
-	IPPROTO_SWIPE                     = 0x35
-	IPPROTO_TCF                       = 0x57
-	IPPROTO_TCP                       = 0x6
-	IPPROTO_TP                        = 0x1d
-	IPPROTO_TPXX                      = 0x27
-	IPPROTO_TRUNK1                    = 0x17
-	IPPROTO_TRUNK2                    = 0x18
-	IPPROTO_TTP                       = 0x54
-	IPPROTO_UDP                       = 0x11
-	IPPROTO_VINES                     = 0x53
-	IPPROTO_VISA                      = 0x46
-	IPPROTO_VMTP                      = 0x51
-	IPPROTO_WBEXPAK                   = 0x4f
-	IPPROTO_WBMON                     = 0x4e
-	IPPROTO_WSN                       = 0x4a
-	IPPROTO_XNET                      = 0xf
-	IPPROTO_XTP                       = 0x24
-	IPV6_2292DSTOPTS                  = 0x17
-	IPV6_2292HOPLIMIT                 = 0x14
-	IPV6_2292HOPOPTS                  = 0x16
-	IPV6_2292NEXTHOP                  = 0x15
-	IPV6_2292PKTINFO                  = 0x13
-	IPV6_2292PKTOPTIONS               = 0x19
-	IPV6_2292RTHDR                    = 0x18
-	IPV6_BINDV6ONLY                   = 0x1b
-	IPV6_BOUND_IF                     = 0x7d
-	IPV6_CHECKSUM                     = 0x1a
-	IPV6_DEFAULT_MULTICAST_HOPS       = 0x1
-	IPV6_DEFAULT_MULTICAST_LOOP       = 0x1
-	IPV6_DEFHLIM                      = 0x40
-	IPV6_FAITH                        = 0x1d
-	IPV6_FLOWINFO_MASK                = 0xffffff0f
-	IPV6_FLOWLABEL_MASK               = 0xffff0f00
-	IPV6_FLOW_ECN_MASK                = 0x300
-	IPV6_FRAGTTL                      = 0x3c
-	IPV6_FW_ADD                       = 0x1e
-	IPV6_FW_DEL                       = 0x1f
-	IPV6_FW_FLUSH                     = 0x20
-	IPV6_FW_GET                       = 0x22
-	IPV6_FW_ZERO                      = 0x21
-	IPV6_HLIMDEC                      = 0x1
-	IPV6_IPSEC_POLICY                 = 0x1c
-	IPV6_JOIN_GROUP                   = 0xc
-	IPV6_LEAVE_GROUP                  = 0xd
-	IPV6_MAXHLIM                      = 0xff
-	IPV6_MAXOPTHDR                    = 0x800
-	IPV6_MAXPACKET                    = 0xffff
-	IPV6_MAX_GROUP_SRC_FILTER         = 0x200
-	IPV6_MAX_MEMBERSHIPS              = 0xfff
-	IPV6_MAX_SOCK_SRC_FILTER          = 0x80
-	IPV6_MIN_MEMBERSHIPS              = 0x1f
-	IPV6_MMTU                         = 0x500
-	IPV6_MULTICAST_HOPS               = 0xa
-	IPV6_MULTICAST_IF                 = 0x9
-	IPV6_MULTICAST_LOOP               = 0xb
-	IPV6_PORTRANGE                    = 0xe
-	IPV6_PORTRANGE_DEFAULT            = 0x0
-	IPV6_PORTRANGE_HIGH               = 0x1
-	IPV6_PORTRANGE_LOW                = 0x2
-	IPV6_RECVTCLASS                   = 0x23
-	IPV6_RTHDR_LOOSE                  = 0x0
-	IPV6_RTHDR_STRICT                 = 0x1
-	IPV6_RTHDR_TYPE_0                 = 0x0
-	IPV6_SOCKOPT_RESERVED1            = 0x3
-	IPV6_TCLASS                       = 0x24
-	IPV6_UNICAST_HOPS                 = 0x4
-	IPV6_V6ONLY                       = 0x1b
-	IPV6_VERSION                      = 0x60
-	IPV6_VERSION_MASK                 = 0xf0
-	IP_ADD_MEMBERSHIP                 = 0xc
-	IP_ADD_SOURCE_MEMBERSHIP          = 0x46
-	IP_BLOCK_SOURCE                   = 0x48
-	IP_BOUND_IF                       = 0x19
-	IP_DEFAULT_MULTICAST_LOOP         = 0x1
-	IP_DEFAULT_MULTICAST_TTL          = 0x1
-	IP_DF                             = 0x4000
-	IP_DROP_MEMBERSHIP                = 0xd
-	IP_DROP_SOURCE_MEMBERSHIP         = 0x47
-	IP_DUMMYNET_CONFIGURE             = 0x3c
-	IP_DUMMYNET_DEL                   = 0x3d
-	IP_DUMMYNET_FLUSH                 = 0x3e
-	IP_DUMMYNET_GET                   = 0x40
-	IP_FAITH                          = 0x16
-	IP_FW_ADD                         = 0x28
-	IP_FW_DEL                         = 0x29
-	IP_FW_FLUSH                       = 0x2a
-	IP_FW_GET                         = 0x2c
-	IP_FW_RESETLOG                    = 0x2d
-	IP_FW_ZERO                        = 0x2b
-	IP_HDRINCL                        = 0x2
-	IP_IPSEC_POLICY                   = 0x15
-	IP_MAXPACKET                      = 0xffff
-	IP_MAX_GROUP_SRC_FILTER           = 0x200
-	IP_MAX_MEMBERSHIPS                = 0xfff
-	IP_MAX_SOCK_MUTE_FILTER           = 0x80
-	IP_MAX_SOCK_SRC_FILTER            = 0x80
-	IP_MF                             = 0x2000
-	IP_MIN_MEMBERSHIPS                = 0x1f
-	IP_MSFILTER                       = 0x4a
-	IP_MSS                            = 0x240
-	IP_MULTICAST_IF                   = 0x9
-	IP_MULTICAST_IFINDEX              = 0x42
-	IP_MULTICAST_LOOP                 = 0xb
-	IP_MULTICAST_TTL                  = 0xa
-	IP_MULTICAST_VIF                  = 0xe
-	IP_NAT__XXX                       = 0x37
-	IP_OFFMASK                        = 0x1fff
-	IP_OLD_FW_ADD                     = 0x32
-	IP_OLD_FW_DEL                     = 0x33
-	IP_OLD_FW_FLUSH                   = 0x34
-	IP_OLD_FW_GET                     = 0x36
-	IP_OLD_FW_RESETLOG                = 0x38
-	IP_OLD_FW_ZERO                    = 0x35
-	IP_OPTIONS                        = 0x1
-	IP_PKTINFO                        = 0x1a
-	IP_PORTRANGE                      = 0x13
-	IP_PORTRANGE_DEFAULT              = 0x0
-	IP_PORTRANGE_HIGH                 = 0x1
-	IP_PORTRANGE_LOW                  = 0x2
-	IP_RECVDSTADDR                    = 0x7
-	IP_RECVIF                         = 0x14
-	IP_RECVOPTS                       = 0x5
-	IP_RECVPKTINFO                    = 0x1a
-	IP_RECVRETOPTS                    = 0x6
-	IP_RECVTOS                        = 0x1b
-	IP_RECVTTL                        = 0x18
-	IP_RETOPTS                        = 0x8
-	IP_RF                             = 0x8000
-	IP_RSVP_OFF                       = 0x10
-	IP_RSVP_ON                        = 0xf
-	IP_RSVP_VIF_OFF                   = 0x12
-	IP_RSVP_VIF_ON                    = 0x11
-	IP_STRIPHDR                       = 0x17
-	IP_TOS                            = 0x3
-	IP_TRAFFIC_MGT_BACKGROUND         = 0x41
-	IP_TTL                            = 0x4
-	IP_UNBLOCK_SOURCE                 = 0x49
-	ISIG                              = 0x80
-	ISTRIP                            = 0x20
-	IUTF8                             = 0x4000
-	IXANY                             = 0x800
-	IXOFF                             = 0x400
-	IXON                              = 0x200
-	KERN_HOSTNAME                     = 0xa
-	KERN_OSRELEASE                    = 0x2
-	KERN_OSTYPE                       = 0x1
-	KERN_VERSION                      = 0x4
-	LOCK_EX                           = 0x2
-	LOCK_NB                           = 0x4
-	LOCK_SH                           = 0x1
-	LOCK_UN                           = 0x8
-	MADV_CAN_REUSE                    = 0x9
-	MADV_DONTNEED                     = 0x4
-	MADV_FREE                         = 0x5
-	MADV_FREE_REUSABLE                = 0x7
-	MADV_FREE_REUSE                   = 0x8
-	MADV_NORMAL                       = 0x0
-	MADV_PAGEOUT                      = 0xa
-	MADV_RANDOM                       = 0x1
-	MADV_SEQUENTIAL                   = 0x2
-	MADV_WILLNEED                     = 0x3
-	MADV_ZERO_WIRED_PAGES             = 0x6
-	MAP_ANON                          = 0x1000
-	MAP_ANONYMOUS                     = 0x1000
-	MAP_COPY                          = 0x2
-	MAP_FILE                          = 0x0
-	MAP_FIXED                         = 0x10
-	MAP_HASSEMAPHORE                  = 0x200
-	MAP_JIT                           = 0x800
-	MAP_NOCACHE                       = 0x400
-	MAP_NOEXTEND                      = 0x100
-	MAP_NORESERVE                     = 0x40
-	MAP_PRIVATE                       = 0x2
-	MAP_RENAME                        = 0x20
-	MAP_RESERVED0080                  = 0x80
-	MAP_RESILIENT_CODESIGN            = 0x2000
-	MAP_RESILIENT_MEDIA               = 0x4000
-	MAP_SHARED                        = 0x1
-	MCL_CURRENT                       = 0x1
-	MCL_FUTURE                        = 0x2
-	MNT_ASYNC                         = 0x40
-	MNT_AUTOMOUNTED                   = 0x400000
-	MNT_CMDFLAGS                      = 0xf0000
-	MNT_CPROTECT                      = 0x80
-	MNT_DEFWRITE                      = 0x2000000
-	MNT_DONTBROWSE                    = 0x100000
-	MNT_DOVOLFS                       = 0x8000
-	MNT_DWAIT                         = 0x4
-	MNT_EXPORTED                      = 0x100
-	MNT_FORCE                         = 0x80000
-	MNT_IGNORE_OWNERSHIP              = 0x200000
-	MNT_JOURNALED                     = 0x800000
-	MNT_LOCAL                         = 0x1000
-	MNT_MULTILABEL                    = 0x4000000
-	MNT_NOATIME                       = 0x10000000
-	MNT_NOBLOCK                       = 0x20000
-	MNT_NODEV                         = 0x10
-	MNT_NOEXEC                        = 0x4
-	MNT_NOSUID                        = 0x8
-	MNT_NOUSERXATTR                   = 0x1000000
-	MNT_NOWAIT                        = 0x2
-	MNT_QUARANTINE                    = 0x400
-	MNT_QUOTA                         = 0x2000
-	MNT_RDONLY                        = 0x1
-	MNT_RELOAD                        = 0x40000
-	MNT_ROOTFS                        = 0x4000
-	MNT_SYNCHRONOUS                   = 0x2
-	MNT_UNION                         = 0x20
-	MNT_UNKNOWNPERMISSIONS            = 0x200000
-	MNT_UPDATE                        = 0x10000
-	MNT_VISFLAGMASK                   = 0x17f0f5ff
-	MNT_WAIT                          = 0x1
-	MSG_CTRUNC                        = 0x20
-	MSG_DONTROUTE                     = 0x4
-	MSG_DONTWAIT                      = 0x80
-	MSG_EOF                           = 0x100
-	MSG_EOR                           = 0x8
-	MSG_FLUSH                         = 0x400
-	MSG_HAVEMORE                      = 0x2000
-	MSG_HOLD                          = 0x800
-	MSG_NEEDSA                        = 0x10000
-	MSG_OOB                           = 0x1
-	MSG_PEEK                          = 0x2
-	MSG_RCVMORE                       = 0x4000
-	MSG_SEND                          = 0x1000
-	MSG_TRUNC                         = 0x10
-	MSG_WAITALL                       = 0x40
-	MSG_WAITSTREAM                    = 0x200
-	MS_ASYNC                          = 0x1
-	MS_DEACTIVATE                     = 0x8
-	MS_INVALIDATE                     = 0x2
-	MS_KILLPAGES                      = 0x4
-	MS_SYNC                           = 0x10
-	NAME_MAX                          = 0xff
-	NET_RT_DUMP                       = 0x1
-	NET_RT_DUMP2                      = 0x7
-	NET_RT_FLAGS                      = 0x2
-	NET_RT_IFLIST                     = 0x3
-	NET_RT_IFLIST2                    = 0x6
-	NET_RT_MAXID                      = 0xa
-	NET_RT_STAT                       = 0x4
-	NET_RT_TRASH                      = 0x5
-	NFDBITS                           = 0x20
-	NL0                               = 0x0
-	NL1                               = 0x100
-	NL2                               = 0x200
-	NL3                               = 0x300
-	NLDLY                             = 0x300
-	NOFLSH                            = 0x80000000
-	NOKERNINFO                        = 0x2000000
-	NOTE_ABSOLUTE                     = 0x8
-	NOTE_ATTRIB                       = 0x8
-	NOTE_BACKGROUND                   = 0x40
-	NOTE_CHILD                        = 0x4
-	NOTE_CRITICAL                     = 0x20
-	NOTE_DELETE                       = 0x1
-	NOTE_EXEC                         = 0x20000000
-	NOTE_EXIT                         = 0x80000000
-	NOTE_EXITSTATUS                   = 0x4000000
-	NOTE_EXIT_CSERROR                 = 0x40000
-	NOTE_EXIT_DECRYPTFAIL             = 0x10000
-	NOTE_EXIT_DETAIL                  = 0x2000000
-	NOTE_EXIT_DETAIL_MASK             = 0x70000
-	NOTE_EXIT_MEMORY                  = 0x20000
-	NOTE_EXIT_REPARENTED              = 0x80000
-	NOTE_EXTEND                       = 0x4
-	NOTE_FFAND                        = 0x40000000
-	NOTE_FFCOPY                       = 0xc0000000
-	NOTE_FFCTRLMASK                   = 0xc0000000
-	NOTE_FFLAGSMASK                   = 0xffffff
-	NOTE_FFNOP                        = 0x0
-	NOTE_FFOR                         = 0x80000000
-	NOTE_FORK                         = 0x40000000
-	NOTE_FUNLOCK                      = 0x100
-	NOTE_LEEWAY                       = 0x10
-	NOTE_LINK                         = 0x10
-	NOTE_LOWAT                        = 0x1
-	NOTE_MACH_CONTINUOUS_TIME         = 0x80
-	NOTE_NONE                         = 0x80
-	NOTE_NSECONDS                     = 0x4
-	NOTE_OOB                          = 0x2
-	NOTE_PCTRLMASK                    = -0x100000
-	NOTE_PDATAMASK                    = 0xfffff
-	NOTE_REAP                         = 0x10000000
-	NOTE_RENAME                       = 0x20
-	NOTE_REVOKE                       = 0x40
-	NOTE_SECONDS                      = 0x1
-	NOTE_SIGNAL                       = 0x8000000
-	NOTE_TRACK                        = 0x1
-	NOTE_TRACKERR                     = 0x2
-	NOTE_TRIGGER                      = 0x1000000
-	NOTE_USECONDS                     = 0x2
-	NOTE_VM_ERROR                     = 0x10000000
-	NOTE_VM_PRESSURE                  = 0x80000000
-	NOTE_VM_PRESSURE_SUDDEN_TERMINATE = 0x20000000
-	NOTE_VM_PRESSURE_TERMINATE        = 0x40000000
-	NOTE_WRITE                        = 0x2
-	OCRNL                             = 0x10
-	OFDEL                             = 0x20000
-	OFILL                             = 0x80
-	ONLCR                             = 0x2
-	ONLRET                            = 0x40
-	ONOCR                             = 0x20
-	ONOEOT                            = 0x8
-	OPOST                             = 0x1
-	OXTABS                            = 0x4
-	O_ACCMODE                         = 0x3
-	O_ALERT                           = 0x20000000
-	O_APPEND                          = 0x8
-	O_ASYNC                           = 0x40
-	O_CLOEXEC                         = 0x1000000
-	O_CREAT                           = 0x200
-	O_DIRECTORY                       = 0x100000
-	O_DP_GETRAWENCRYPTED              = 0x1
-	O_DP_GETRAWUNENCRYPTED            = 0x2
-	O_DSYNC                           = 0x400000
-	O_EVTONLY                         = 0x8000
-	O_EXCL                            = 0x800
-	O_EXLOCK                          = 0x20
-	O_FSYNC                           = 0x80
-	O_NDELAY                          = 0x4
-	O_NOCTTY                          = 0x20000
-	O_NOFOLLOW                        = 0x100
-	O_NONBLOCK                        = 0x4
-	O_POPUP                           = 0x80000000
-	O_RDONLY                          = 0x0
-	O_RDWR                            = 0x2
-	O_SHLOCK                          = 0x10
-	O_SYMLINK                         = 0x200000
-	O_SYNC                            = 0x80
-	O_TRUNC                           = 0x400
-	O_WRONLY                          = 0x1
-	PARENB                            = 0x1000
-	PARMRK                            = 0x8
-	PARODD                            = 0x2000
-	PENDIN                            = 0x20000000
-	PRIO_PGRP                         = 0x1
-	PRIO_PROCESS                      = 0x0
-	PRIO_USER                         = 0x2
-	PROT_EXEC                         = 0x4
-	PROT_NONE                         = 0x0
-	PROT_READ                         = 0x1
-	PROT_WRITE                        = 0x2
-	PT_ATTACH                         = 0xa
-	PT_ATTACHEXC                      = 0xe
-	PT_CONTINUE                       = 0x7
-	PT_DENY_ATTACH                    = 0x1f
-	PT_DETACH                         = 0xb
-	PT_FIRSTMACH                      = 0x20
-	PT_FORCEQUOTA                     = 0x1e
-	PT_KILL                           = 0x8
-	PT_READ_D                         = 0x2
-	PT_READ_I                         = 0x1
-	PT_READ_U                         = 0x3
-	PT_SIGEXC                         = 0xc
-	PT_STEP                           = 0x9
-	PT_THUPDATE                       = 0xd
-	PT_TRACE_ME                       = 0x0
-	PT_WRITE_D                        = 0x5
-	PT_WRITE_I                        = 0x4
-	PT_WRITE_U                        = 0x6
-	RLIMIT_AS                         = 0x5
-	RLIMIT_CORE                       = 0x4
-	RLIMIT_CPU                        = 0x0
-	RLIMIT_CPU_USAGE_MONITOR          = 0x2
-	RLIMIT_DATA                       = 0x2
-	RLIMIT_FSIZE                      = 0x1
-	RLIMIT_MEMLOCK                    = 0x6
-	RLIMIT_NOFILE                     = 0x8
-	RLIMIT_NPROC                      = 0x7
-	RLIMIT_RSS                        = 0x5
-	RLIMIT_STACK                      = 0x3
-	RLIM_INFINITY                     = 0x7fffffffffffffff
-	RTAX_AUTHOR                       = 0x6
-	RTAX_BRD                          = 0x7
-	RTAX_DST                          = 0x0
-	RTAX_GATEWAY                      = 0x1
-	RTAX_GENMASK                      = 0x3
-	RTAX_IFA                          = 0x5
-	RTAX_IFP                          = 0x4
-	RTAX_MAX                          = 0x8
-	RTAX_NETMASK                      = 0x2
-	RTA_AUTHOR                        = 0x40
-	RTA_BRD                           = 0x80
-	RTA_DST                           = 0x1
-	RTA_GATEWAY                       = 0x2
-	RTA_GENMASK                       = 0x8
-	RTA_IFA                           = 0x20
-	RTA_IFP                           = 0x10
-	RTA_NETMASK                       = 0x4
-	RTF_BLACKHOLE                     = 0x1000
-	RTF_BROADCAST                     = 0x400000
-	RTF_CLONING                       = 0x100
-	RTF_CONDEMNED                     = 0x2000000
-	RTF_DELCLONE                      = 0x80
-	RTF_DONE                          = 0x40
-	RTF_DYNAMIC                       = 0x10
-	RTF_GATEWAY                       = 0x2
-	RTF_HOST                          = 0x4
-	RTF_IFREF                         = 0x4000000
-	RTF_IFSCOPE                       = 0x1000000
-	RTF_LLINFO                        = 0x400
-	RTF_LOCAL                         = 0x200000
-	RTF_MODIFIED                      = 0x20
-	RTF_MULTICAST                     = 0x800000
-	RTF_NOIFREF                       = 0x2000
-	RTF_PINNED                        = 0x100000
-	RTF_PRCLONING                     = 0x10000
-	RTF_PROTO1                        = 0x8000
-	RTF_PROTO2                        = 0x4000
-	RTF_PROTO3                        = 0x40000
-	RTF_PROXY                         = 0x8000000
-	RTF_REJECT                        = 0x8
-	RTF_ROUTER                        = 0x10000000
-	RTF_STATIC                        = 0x800
-	RTF_UP                            = 0x1
-	RTF_WASCLONED                     = 0x20000
-	RTF_XRESOLVE                      = 0x200
-	RTM_ADD                           = 0x1
-	RTM_CHANGE                        = 0x3
-	RTM_DELADDR                       = 0xd
-	RTM_DELETE                        = 0x2
-	RTM_DELMADDR                      = 0x10
-	RTM_GET                           = 0x4
-	RTM_GET2                          = 0x14
-	RTM_IFINFO                        = 0xe
-	RTM_IFINFO2                       = 0x12
-	RTM_LOCK                          = 0x8
-	RTM_LOSING                        = 0x5
-	RTM_MISS                          = 0x7
-	RTM_NEWADDR                       = 0xc
-	RTM_NEWMADDR                      = 0xf
-	RTM_NEWMADDR2                     = 0x13
-	RTM_OLDADD                        = 0x9
-	RTM_OLDDEL                        = 0xa
-	RTM_REDIRECT                      = 0x6
-	RTM_RESOLVE                       = 0xb
-	RTM_RTTUNIT                       = 0xf4240
-	RTM_VERSION                       = 0x5
-	RTV_EXPIRE                        = 0x4
-	RTV_HOPCOUNT                      = 0x2
-	RTV_MTU                           = 0x1
-	RTV_RPIPE                         = 0x8
-	RTV_RTT                           = 0x40
-	RTV_RTTVAR                        = 0x80
-	RTV_SPIPE                         = 0x10
-	RTV_SSTHRESH                      = 0x20
-	RUSAGE_CHILDREN                   = -0x1
-	RUSAGE_SELF                       = 0x0
-	SCM_CREDS                         = 0x3
-	SCM_RIGHTS                        = 0x1
-	SCM_TIMESTAMP                     = 0x2
-	SCM_TIMESTAMP_MONOTONIC           = 0x4
-	SHUT_RD                           = 0x0
-	SHUT_RDWR                         = 0x2
-	SHUT_WR                           = 0x1
-	SIOCADDMULTI                      = 0x80206931
-	SIOCAIFADDR                       = 0x8040691a
-	SIOCARPIPLL                       = 0xc0206928
-	SIOCATMARK                        = 0x40047307
-	SIOCAUTOADDR                      = 0xc0206926
-	SIOCAUTONETMASK                   = 0x80206927
-	SIOCDELMULTI                      = 0x80206932
-	SIOCDIFADDR                       = 0x80206919
-	SIOCDIFPHYADDR                    = 0x80206941
-	SIOCGDRVSPEC                      = 0xc028697b
-	SIOCGETVLAN                       = 0xc020697f
-	SIOCGHIWAT                        = 0x40047301
-	SIOCGIFADDR                       = 0xc0206921
-	SIOCGIFALTMTU                     = 0xc0206948
-	SIOCGIFASYNCMAP                   = 0xc020697c
-	SIOCGIFBOND                       = 0xc0206947
-	SIOCGIFBRDADDR                    = 0xc0206923
-	SIOCGIFCAP                        = 0xc020695b
-	SIOCGIFCONF                       = 0xc00c6924
-	SIOCGIFDEVMTU                     = 0xc0206944
-	SIOCGIFDSTADDR                    = 0xc0206922
-	SIOCGIFFLAGS                      = 0xc0206911
-	SIOCGIFGENERIC                    = 0xc020693a
-	SIOCGIFKPI                        = 0xc0206987
-	SIOCGIFMAC                        = 0xc0206982
-	SIOCGIFMEDIA                      = 0xc02c6938
-	SIOCGIFMETRIC                     = 0xc0206917
-	SIOCGIFMTU                        = 0xc0206933
-	SIOCGIFNETMASK                    = 0xc0206925
-	SIOCGIFPDSTADDR                   = 0xc0206940
-	SIOCGIFPHYS                       = 0xc0206935
-	SIOCGIFPSRCADDR                   = 0xc020693f
-	SIOCGIFSTATUS                     = 0xc331693d
-	SIOCGIFVLAN                       = 0xc020697f
-	SIOCGIFWAKEFLAGS                  = 0xc0206988
-	SIOCGLOWAT                        = 0x40047303
-	SIOCGPGRP                         = 0x40047309
-	SIOCIFCREATE                      = 0xc0206978
-	SIOCIFCREATE2                     = 0xc020697a
-	SIOCIFDESTROY                     = 0x80206979
-	SIOCIFGCLONERS                    = 0xc0106981
-	SIOCRSLVMULTI                     = 0xc010693b
-	SIOCSDRVSPEC                      = 0x8028697b
-	SIOCSETVLAN                       = 0x8020697e
-	SIOCSHIWAT                        = 0x80047300
-	SIOCSIFADDR                       = 0x8020690c
-	SIOCSIFALTMTU                     = 0x80206945
-	SIOCSIFASYNCMAP                   = 0x8020697d
-	SIOCSIFBOND                       = 0x80206946
-	SIOCSIFBRDADDR                    = 0x80206913
-	SIOCSIFCAP                        = 0x8020695a
-	SIOCSIFDSTADDR                    = 0x8020690e
-	SIOCSIFFLAGS                      = 0x80206910
-	SIOCSIFGENERIC                    = 0x80206939
-	SIOCSIFKPI                        = 0x80206986
-	SIOCSIFLLADDR                     = 0x8020693c
-	SIOCSIFMAC                        = 0x80206983
-	SIOCSIFMEDIA                      = 0xc0206937
-	SIOCSIFMETRIC                     = 0x80206918
-	SIOCSIFMTU                        = 0x80206934
-	SIOCSIFNETMASK                    = 0x80206916
-	SIOCSIFPHYADDR                    = 0x8040693e
-	SIOCSIFPHYS                       = 0x80206936
-	SIOCSIFVLAN                       = 0x8020697e
-	SIOCSLOWAT                        = 0x80047302
-	SIOCSPGRP                         = 0x80047308
-	SOCK_DGRAM                        = 0x2
-	SOCK_MAXADDRLEN                   = 0xff
-	SOCK_RAW                          = 0x3
-	SOCK_RDM                          = 0x4
-	SOCK_SEQPACKET                    = 0x5
-	SOCK_STREAM                       = 0x1
-	SOL_SOCKET                        = 0xffff
-	SOMAXCONN                         = 0x80
-	SO_ACCEPTCONN                     = 0x2
-	SO_BROADCAST                      = 0x20
-	SO_DEBUG                          = 0x1
-	SO_DONTROUTE                      = 0x10
-	SO_DONTTRUNC                      = 0x2000
-	SO_ERROR                          = 0x1007
-	SO_KEEPALIVE                      = 0x8
-	SO_LABEL                          = 0x1010
-	SO_LINGER                         = 0x80
-	SO_LINGER_SEC                     = 0x1080
-	SO_NETSVC_MARKING_LEVEL           = 0x1119
-	SO_NET_SERVICE_TYPE               = 0x1116
-	SO_NKE                            = 0x1021
-	SO_NOADDRERR                      = 0x1023
-	SO_NOSIGPIPE                      = 0x1022
-	SO_NOTIFYCONFLICT                 = 0x1026
-	SO_NP_EXTENSIONS                  = 0x1083
-	SO_NREAD                          = 0x1020
-	SO_NUMRCVPKT                      = 0x1112
-	SO_NWRITE                         = 0x1024
-	SO_OOBINLINE                      = 0x100
-	SO_PEERLABEL                      = 0x1011
-	SO_RANDOMPORT                     = 0x1082
-	SO_RCVBUF                         = 0x1002
-	SO_RCVLOWAT                       = 0x1004
-	SO_RCVTIMEO                       = 0x1006
-	SO_REUSEADDR                      = 0x4
-	SO_REUSEPORT                      = 0x200
-	SO_REUSESHAREUID                  = 0x1025
-	SO_SNDBUF                         = 0x1001
-	SO_SNDLOWAT                       = 0x1003
-	SO_SNDTIMEO                       = 0x1005
-	SO_TIMESTAMP                      = 0x400
-	SO_TIMESTAMP_MONOTONIC            = 0x800
-	SO_TYPE                           = 0x1008
-	SO_UPCALLCLOSEWAIT                = 0x1027
-	SO_USELOOPBACK                    = 0x40
-	SO_WANTMORE                       = 0x4000
-	SO_WANTOOBFLAG                    = 0x8000
-	S_IEXEC                           = 0x40
-	S_IFBLK                           = 0x6000
-	S_IFCHR                           = 0x2000
-	S_IFDIR                           = 0x4000
-	S_IFIFO                           = 0x1000
-	S_IFLNK                           = 0xa000
-	S_IFMT                            = 0xf000
-	S_IFREG                           = 0x8000
-	S_IFSOCK                          = 0xc000
-	S_IFWHT                           = 0xe000
-	S_IREAD                           = 0x100
-	S_IRGRP                           = 0x20
-	S_IROTH                           = 0x4
-	S_IRUSR                           = 0x100
-	S_IRWXG                           = 0x38
-	S_IRWXO                           = 0x7
-	S_IRWXU                           = 0x1c0
-	S_ISGID                           = 0x400
-	S_ISTXT                           = 0x200
-	S_ISUID                           = 0x800
-	S_ISVTX                           = 0x200
-	S_IWGRP                           = 0x10
-	S_IWOTH                           = 0x2
-	S_IWRITE                          = 0x80
-	S_IWUSR                           = 0x80
-	S_IXGRP                           = 0x8
-	S_IXOTH                           = 0x1
-	S_IXUSR                           = 0x40
-	TAB0                              = 0x0
-	TAB1                              = 0x400
-	TAB2                              = 0x800
-	TAB3                              = 0x4
-	TABDLY                            = 0xc04
-	TCIFLUSH                          = 0x1
-	TCIOFF                            = 0x3
-	TCIOFLUSH                         = 0x3
-	TCION                             = 0x4
-	TCOFLUSH                          = 0x2
-	TCOOFF                            = 0x1
-	TCOON                             = 0x2
-	TCP_CONNECTIONTIMEOUT             = 0x20
-	TCP_CONNECTION_INFO               = 0x106
-	TCP_ENABLE_ECN                    = 0x104
-	TCP_FASTOPEN                      = 0x105
-	TCP_KEEPALIVE                     = 0x10
-	TCP_KEEPCNT                       = 0x102
-	TCP_KEEPINTVL                     = 0x101
-	TCP_MAXHLEN                       = 0x3c
-	TCP_MAXOLEN                       = 0x28
-	TCP_MAXSEG                        = 0x2
-	TCP_MAXWIN                        = 0xffff
-	TCP_MAX_SACK                      = 0x4
-	TCP_MAX_WINSHIFT                  = 0xe
-	TCP_MINMSS                        = 0xd8
-	TCP_MSS                           = 0x200
-	TCP_NODELAY                       = 0x1
-	TCP_NOOPT                         = 0x8
-	TCP_NOPUSH                        = 0x4
-	TCP_NOTSENT_LOWAT                 = 0x201
-	TCP_RXT_CONNDROPTIME              = 0x80
-	TCP_RXT_FINDROP                   = 0x100
-	TCP_SENDMOREACKS                  = 0x103
-	TCSAFLUSH                         = 0x2
-	TIOCCBRK                          = 0x2000747a
-	TIOCCDTR                          = 0x20007478
-	TIOCCONS                          = 0x80047462
-	TIOCDCDTIMESTAMP                  = 0x40107458
-	TIOCDRAIN                         = 0x2000745e
-	TIOCDSIMICROCODE                  = 0x20007455
-	TIOCEXCL                          = 0x2000740d
-	TIOCEXT                           = 0x80047460
-	TIOCFLUSH                         = 0x80047410
-	TIOCGDRAINWAIT                    = 0x40047456
-	TIOCGETA                          = 0x40487413
-	TIOCGETD                          = 0x4004741a
-	TIOCGPGRP                         = 0x40047477
-	TIOCGWINSZ                        = 0x40087468
-	TIOCIXOFF                         = 0x20007480
-	TIOCIXON                          = 0x20007481
-	TIOCMBIC                          = 0x8004746b
-	TIOCMBIS                          = 0x8004746c
-	TIOCMGDTRWAIT                     = 0x4004745a
-	TIOCMGET                          = 0x4004746a
-	TIOCMODG                          = 0x40047403
-	TIOCMODS                          = 0x80047404
-	TIOCMSDTRWAIT                     = 0x8004745b
-	TIOCMSET                          = 0x8004746d
-	TIOCM_CAR                         = 0x40
-	TIOCM_CD                          = 0x40
-	TIOCM_CTS                         = 0x20
-	TIOCM_DSR                         = 0x100
-	TIOCM_DTR                         = 0x2
-	TIOCM_LE                          = 0x1
-	TIOCM_RI                          = 0x80
-	TIOCM_RNG                         = 0x80
-	TIOCM_RTS                         = 0x4
-	TIOCM_SR                          = 0x10
-	TIOCM_ST                          = 0x8
-	TIOCNOTTY                         = 0x20007471
-	TIOCNXCL                          = 0x2000740e
-	TIOCOUTQ                          = 0x40047473
-	TIOCPKT                           = 0x80047470
-	TIOCPKT_DATA                      = 0x0
-	TIOCPKT_DOSTOP                    = 0x20
-	TIOCPKT_FLUSHREAD                 = 0x1
-	TIOCPKT_FLUSHWRITE                = 0x2
-	TIOCPKT_IOCTL                     = 0x40
-	TIOCPKT_NOSTOP                    = 0x10
-	TIOCPKT_START                     = 0x8
-	TIOCPKT_STOP                      = 0x4
-	TIOCPTYGNAME                      = 0x40807453
-	TIOCPTYGRANT                      = 0x20007454
-	TIOCPTYUNLK                       = 0x20007452
-	TIOCREMOTE                        = 0x80047469
-	TIOCSBRK                          = 0x2000747b
-	TIOCSCONS                         = 0x20007463
-	TIOCSCTTY                         = 0x20007461
-	TIOCSDRAINWAIT                    = 0x80047457
-	TIOCSDTR                          = 0x20007479
-	TIOCSETA                          = 0x80487414
-	TIOCSETAF                         = 0x80487416
-	TIOCSETAW                         = 0x80487415
-	TIOCSETD                          = 0x8004741b
-	TIOCSIG                           = 0x2000745f
-	TIOCSPGRP                         = 0x80047476
-	TIOCSTART                         = 0x2000746e
-	TIOCSTAT                          = 0x20007465
-	TIOCSTI                           = 0x80017472
-	TIOCSTOP                          = 0x2000746f
-	TIOCSWINSZ                        = 0x80087467
-	TIOCTIMESTAMP                     = 0x40107459
-	TIOCUCNTL                         = 0x80047466
-	TOSTOP                            = 0x400000
-	VDISCARD                          = 0xf
-	VDSUSP                            = 0xb
-	VEOF                              = 0x0
-	VEOL                              = 0x1
-	VEOL2                             = 0x2
-	VERASE                            = 0x3
-	VINTR                             = 0x8
-	VKILL                             = 0x5
-	VLNEXT                            = 0xe
-	VMIN                              = 0x10
-	VM_LOADAVG                        = 0x2
-	VM_MACHFACTOR                     = 0x4
-	VM_MAXID                          = 0x6
-	VM_METER                          = 0x1
-	VM_SWAPUSAGE                      = 0x5
-	VQUIT                             = 0x9
-	VREPRINT                          = 0x6
-	VSTART                            = 0xc
-	VSTATUS                           = 0x12
-	VSTOP                             = 0xd
-	VSUSP                             = 0xa
-	VT0                               = 0x0
-	VT1                               = 0x10000
-	VTDLY                             = 0x10000
-	VTIME                             = 0x11
-	VWERASE                           = 0x4
-	WCONTINUED                        = 0x10
-	WCOREFLAG                         = 0x80
-	WEXITED                           = 0x4
-	WNOHANG                           = 0x1
-	WNOWAIT                           = 0x20
-	WORDSIZE                          = 0x40
-	WSTOPPED                          = 0x8
-	WUNTRACED                         = 0x2
-	XATTR_CREATE                      = 0x2
-	XATTR_NODEFAULT                   = 0x10
-	XATTR_NOFOLLOW                    = 0x1
-	XATTR_NOSECURITY                  = 0x8
-	XATTR_REPLACE                     = 0x4
-	XATTR_SHOWCOMPRESSION             = 0x20
-)
-
-// Errors
-const (
-	E2BIG           = syscall.Errno(0x7)
-	EACCES          = syscall.Errno(0xd)
-	EADDRINUSE      = syscall.Errno(0x30)
-	EADDRNOTAVAIL   = syscall.Errno(0x31)
-	EAFNOSUPPORT    = syscall.Errno(0x2f)
-	EAGAIN          = syscall.Errno(0x23)
-	EALREADY        = syscall.Errno(0x25)
-	EAUTH           = syscall.Errno(0x50)
-	EBADARCH        = syscall.Errno(0x56)
-	EBADEXEC        = syscall.Errno(0x55)
-	EBADF           = syscall.Errno(0x9)
-	EBADMACHO       = syscall.Errno(0x58)
-	EBADMSG         = syscall.Errno(0x5e)
-	EBADRPC         = syscall.Errno(0x48)
-	EBUSY           = syscall.Errno(0x10)
-	ECANCELED       = syscall.Errno(0x59)
-	ECHILD          = syscall.Errno(0xa)
-	ECONNABORTED    = syscall.Errno(0x35)
-	ECONNREFUSED    = syscall.Errno(0x3d)
-	ECONNRESET      = syscall.Errno(0x36)
-	EDEADLK         = syscall.Errno(0xb)
-	EDESTADDRREQ    = syscall.Errno(0x27)
-	EDEVERR         = syscall.Errno(0x53)
-	EDOM            = syscall.Errno(0x21)
-	EDQUOT          = syscall.Errno(0x45)
-	EEXIST          = syscall.Errno(0x11)
-	EFAULT          = syscall.Errno(0xe)
-	EFBIG           = syscall.Errno(0x1b)
-	EFTYPE          = syscall.Errno(0x4f)
-	EHOSTDOWN       = syscall.Errno(0x40)
-	EHOSTUNREACH    = syscall.Errno(0x41)
-	EIDRM           = syscall.Errno(0x5a)
-	EILSEQ          = syscall.Errno(0x5c)
-	EINPROGRESS     = syscall.Errno(0x24)
-	EINTR           = syscall.Errno(0x4)
-	EINVAL          = syscall.Errno(0x16)
-	EIO             = syscall.Errno(0x5)
-	EISCONN         = syscall.Errno(0x38)
-	EISDIR          = syscall.Errno(0x15)
-	ELAST           = syscall.Errno(0x6a)
-	ELOOP           = syscall.Errno(0x3e)
-	EMFILE          = syscall.Errno(0x18)
-	EMLINK          = syscall.Errno(0x1f)
-	EMSGSIZE        = syscall.Errno(0x28)
-	EMULTIHOP       = syscall.Errno(0x5f)
-	ENAMETOOLONG    = syscall.Errno(0x3f)
-	ENEEDAUTH       = syscall.Errno(0x51)
-	ENETDOWN        = syscall.Errno(0x32)
-	ENETRESET       = syscall.Errno(0x34)
-	ENETUNREACH     = syscall.Errno(0x33)
-	ENFILE          = syscall.Errno(0x17)
-	ENOATTR         = syscall.Errno(0x5d)
-	ENOBUFS         = syscall.Errno(0x37)
-	ENODATA         = syscall.Errno(0x60)
-	ENODEV          = syscall.Errno(0x13)
-	ENOENT          = syscall.Errno(0x2)
-	ENOEXEC         = syscall.Errno(0x8)
-	ENOLCK          = syscall.Errno(0x4d)
-	ENOLINK         = syscall.Errno(0x61)
-	ENOMEM          = syscall.Errno(0xc)
-	ENOMSG          = syscall.Errno(0x5b)
-	ENOPOLICY       = syscall.Errno(0x67)
-	ENOPROTOOPT     = syscall.Errno(0x2a)
-	ENOSPC          = syscall.Errno(0x1c)
-	ENOSR           = syscall.Errno(0x62)
-	ENOSTR          = syscall.Errno(0x63)
-	ENOSYS          = syscall.Errno(0x4e)
-	ENOTBLK         = syscall.Errno(0xf)
-	ENOTCONN        = syscall.Errno(0x39)
-	ENOTDIR         = syscall.Errno(0x14)
-	ENOTEMPTY       = syscall.Errno(0x42)
-	ENOTRECOVERABLE = syscall.Errno(0x68)
-	ENOTSOCK        = syscall.Errno(0x26)
-	ENOTSUP         = syscall.Errno(0x2d)
-	ENOTTY          = syscall.Errno(0x19)
-	ENXIO           = syscall.Errno(0x6)
-	EOPNOTSUPP      = syscall.Errno(0x66)
-	EOVERFLOW       = syscall.Errno(0x54)
-	EOWNERDEAD      = syscall.Errno(0x69)
-	EPERM           = syscall.Errno(0x1)
-	EPFNOSUPPORT    = syscall.Errno(0x2e)
-	EPIPE           = syscall.Errno(0x20)
-	EPROCLIM        = syscall.Errno(0x43)
-	EPROCUNAVAIL    = syscall.Errno(0x4c)
-	EPROGMISMATCH   = syscall.Errno(0x4b)
-	EPROGUNAVAIL    = syscall.Errno(0x4a)
-	EPROTO          = syscall.Errno(0x64)
-	EPROTONOSUPPORT = syscall.Errno(0x2b)
-	EPROTOTYPE      = syscall.Errno(0x29)
-	EPWROFF         = syscall.Errno(0x52)
-	EQFULL          = syscall.Errno(0x6a)
-	ERANGE          = syscall.Errno(0x22)
-	EREMOTE         = syscall.Errno(0x47)
-	EROFS           = syscall.Errno(0x1e)
-	ERPCMISMATCH    = syscall.Errno(0x49)
-	ESHLIBVERS      = syscall.Errno(0x57)
-	ESHUTDOWN       = syscall.Errno(0x3a)
-	ESOCKTNOSUPPORT = syscall.Errno(0x2c)
-	ESPIPE          = syscall.Errno(0x1d)
-	ESRCH           = syscall.Errno(0x3)
-	ESTALE          = syscall.Errno(0x46)
-	ETIME           = syscall.Errno(0x65)
-	ETIMEDOUT       = syscall.Errno(0x3c)
-	ETOOMANYREFS    = syscall.Errno(0x3b)
-	ETXTBSY         = syscall.Errno(0x1a)
-	EUSERS          = syscall.Errno(0x44)
-	EWOULDBLOCK     = syscall.Errno(0x23)
-	EXDEV           = syscall.Errno(0x12)
-)
-
-// Signals
-const (
-	SIGABRT   = syscall.Signal(0x6)
-	SIGALRM   = syscall.Signal(0xe)
-	SIGBUS    = syscall.Signal(0xa)
-	SIGCHLD   = syscall.Signal(0x14)
-	SIGCONT   = syscall.Signal(0x13)
-	SIGEMT    = syscall.Signal(0x7)
-	SIGFPE    = syscall.Signal(0x8)
-	SIGHUP    = syscall.Signal(0x1)
-	SIGILL    = syscall.Signal(0x4)
-	SIGINFO   = syscall.Signal(0x1d)
-	SIGINT    = syscall.Signal(0x2)
-	SIGIO     = syscall.Signal(0x17)
-	SIGIOT    = syscall.Signal(0x6)
-	SIGKILL   = syscall.Signal(0x9)
-	SIGPIPE   = syscall.Signal(0xd)
-	SIGPROF   = syscall.Signal(0x1b)
-	SIGQUIT   = syscall.Signal(0x3)
-	SIGSEGV   = syscall.Signal(0xb)
-	SIGSTOP   = syscall.Signal(0x11)
-	SIGSYS    = syscall.Signal(0xc)
-	SIGTERM   = syscall.Signal(0xf)
-	SIGTRAP   = syscall.Signal(0x5)
-	SIGTSTP   = syscall.Signal(0x12)
-	SIGTTIN   = syscall.Signal(0x15)
-	SIGTTOU   = syscall.Signal(0x16)
-	SIGURG    = syscall.Signal(0x10)
-	SIGUSR1   = syscall.Signal(0x1e)
-	SIGUSR2   = syscall.Signal(0x1f)
-	SIGVTALRM = syscall.Signal(0x1a)
-	SIGWINCH  = syscall.Signal(0x1c)
-	SIGXCPU   = syscall.Signal(0x18)
-	SIGXFSZ   = syscall.Signal(0x19)
-)
-
-// Error table
-var errorList = [...]struct {
-	num  syscall.Errno
-	name string
-	desc string
-}{
-	{1, "EPERM", "operation not permitted"},
-	{2, "ENOENT", "no such file or directory"},
-	{3, "ESRCH", "no such process"},
-	{4, "EINTR", "interrupted system call"},
-	{5, "EIO", "input/output error"},
-	{6, "ENXIO", "device not configured"},
-	{7, "E2BIG", "argument list too long"},
-	{8, "ENOEXEC", "exec format error"},
-	{9, "EBADF", "bad file descriptor"},
-	{10, "ECHILD", "no child processes"},
-	{11, "EDEADLK", "resource deadlock avoided"},
-	{12, "ENOMEM", "cannot allocate memory"},
-	{13, "EACCES", "permission denied"},
-	{14, "EFAULT", "bad address"},
-	{15, "ENOTBLK", "block device required"},
-	{16, "EBUSY", "resource busy"},
-	{17, "EEXIST", "file exists"},
-	{18, "EXDEV", "cross-device link"},
-	{19, "ENODEV", "operation not supported by device"},
-	{20, "ENOTDIR", "not a directory"},
-	{21, "EISDIR", "is a directory"},
-	{22, "EINVAL", "invalid argument"},
-	{23, "ENFILE", "too many open files in system"},
-	{24, "EMFILE", "too many open files"},
-	{25, "ENOTTY", "inappropriate ioctl for device"},
-	{26, "ETXTBSY", "text file busy"},
-	{27, "EFBIG", "file too large"},
-	{28, "ENOSPC", "no space left on device"},
-	{29, "ESPIPE", "illegal seek"},
-	{30, "EROFS", "read-only file system"},
-	{31, "EMLINK", "too many links"},
-	{32, "EPIPE", "broken pipe"},
-	{33, "EDOM", "numerical argument out of domain"},
-	{34, "ERANGE", "result too large"},
-	{35, "EAGAIN", "resource temporarily unavailable"},
-	{36, "EINPROGRESS", "operation now in progress"},
-	{37, "EALREADY", "operation already in progress"},
-	{38, "ENOTSOCK", "socket operation on non-socket"},
-	{39, "EDESTADDRREQ", "destination address required"},
-	{40, "EMSGSIZE", "message too long"},
-	{41, "EPROTOTYPE", "protocol wrong type for socket"},
-	{42, "ENOPROTOOPT", "protocol not available"},
-	{43, "EPROTONOSUPPORT", "protocol not supported"},
-	{44, "ESOCKTNOSUPPORT", "socket type not supported"},
-	{45, "ENOTSUP", "operation not supported"},
-	{46, "EPFNOSUPPORT", "protocol family not supported"},
-	{47, "EAFNOSUPPORT", "address family not supported by protocol family"},
-	{48, "EADDRINUSE", "address already in use"},
-	{49, "EADDRNOTAVAIL", "can't assign requested address"},
-	{50, "ENETDOWN", "network is down"},
-	{51, "ENETUNREACH", "network is unreachable"},
-	{52, "ENETRESET", "network dropped connection on reset"},
-	{53, "ECONNABORTED", "software caused connection abort"},
-	{54, "ECONNRESET", "connection reset by peer"},
-	{55, "ENOBUFS", "no buffer space available"},
-	{56, "EISCONN", "socket is already connected"},
-	{57, "ENOTCONN", "socket is not connected"},
-	{58, "ESHUTDOWN", "can't send after socket shutdown"},
-	{59, "ETOOMANYREFS", "too many references: can't splice"},
-	{60, "ETIMEDOUT", "operation timed out"},
-	{61, "ECONNREFUSED", "connection refused"},
-	{62, "ELOOP", "too many levels of symbolic links"},
-	{63, "ENAMETOOLONG", "file name too long"},
-	{64, "EHOSTDOWN", "host is down"},
-	{65, "EHOSTUNREACH", "no route to host"},
-	{66, "ENOTEMPTY", "directory not empty"},
-	{67, "EPROCLIM", "too many processes"},
-	{68, "EUSERS", "too many users"},
-	{69, "EDQUOT", "disc quota exceeded"},
-	{70, "ESTALE", "stale NFS file handle"},
-	{71, "EREMOTE", "too many levels of remote in path"},
-	{72, "EBADRPC", "RPC struct is bad"},
-	{73, "ERPCMISMATCH", "RPC version wrong"},
-	{74, "EPROGUNAVAIL", "RPC prog. not avail"},
-	{75, "EPROGMISMATCH", "program version wrong"},
-	{76, "EPROCUNAVAIL", "bad procedure for program"},
-	{77, "ENOLCK", "no locks available"},
-	{78, "ENOSYS", "function not implemented"},
-	{79, "EFTYPE", "inappropriate file type or format"},
-	{80, "EAUTH", "authentication error"},
-	{81, "ENEEDAUTH", "need authenticator"},
-	{82, "EPWROFF", "device power is off"},
-	{83, "EDEVERR", "device error"},
-	{84, "EOVERFLOW", "value too large to be stored in data type"},
-	{85, "EBADEXEC", "bad executable (or shared library)"},
-	{86, "EBADARCH", "bad CPU type in executable"},
-	{87, "ESHLIBVERS", "shared library version mismatch"},
-	{88, "EBADMACHO", "malformed Mach-o file"},
-	{89, "ECANCELED", "operation canceled"},
-	{90, "EIDRM", "identifier removed"},
-	{91, "ENOMSG", "no message of desired type"},
-	{92, "EILSEQ", "illegal byte sequence"},
-	{93, "ENOATTR", "attribute not found"},
-	{94, "EBADMSG", "bad message"},
-	{95, "EMULTIHOP", "EMULTIHOP (Reserved)"},
-	{96, "ENODATA", "no message available on STREAM"},
-	{97, "ENOLINK", "ENOLINK (Reserved)"},
-	{98, "ENOSR", "no STREAM resources"},
-	{99, "ENOSTR", "not a STREAM"},
-	{100, "EPROTO", "protocol error"},
-	{101, "ETIME", "STREAM ioctl timeout"},
-	{102, "EOPNOTSUPP", "operation not supported on socket"},
-	{103, "ENOPOLICY", "policy not found"},
-	{104, "ENOTRECOVERABLE", "state not recoverable"},
-	{105, "EOWNERDEAD", "previous owner died"},
-	{106, "EQFULL", "interface output queue is full"},
-}
-
-// Signal table
-var signalList = [...]struct {
-	num  syscall.Signal
-	name string
-	desc string
-}{
-	{1, "SIGHUP", "hangup"},
-	{2, "SIGINT", "interrupt"},
-	{3, "SIGQUIT", "quit"},
-	{4, "SIGILL", "illegal instruction"},
-	{5, "SIGTRAP", "trace/BPT trap"},
-	{6, "SIGABRT", "abort trap"},
-	{7, "SIGEMT", "EMT trap"},
-	{8, "SIGFPE", "floating point exception"},
-	{9, "SIGKILL", "killed"},
-	{10, "SIGBUS", "bus error"},
-	{11, "SIGSEGV", "segmentation fault"},
-	{12, "SIGSYS", "bad system call"},
-	{13, "SIGPIPE", "broken pipe"},
-	{14, "SIGALRM", "alarm clock"},
-	{15, "SIGTERM", "terminated"},
-	{16, "SIGURG", "urgent I/O condition"},
-	{17, "SIGSTOP", "suspended (signal)"},
-	{18, "SIGTSTP", "suspended"},
-	{19, "SIGCONT", "continued"},
-	{20, "SIGCHLD", "child exited"},
-	{21, "SIGTTIN", "stopped (tty input)"},
-	{22, "SIGTTOU", "stopped (tty output)"},
-	{23, "SIGIO", "I/O possible"},
-	{24, "SIGXCPU", "cputime limit exceeded"},
-	{25, "SIGXFSZ", "filesize limit exceeded"},
-	{26, "SIGVTALRM", "virtual timer expired"},
-	{27, "SIGPROF", "profiling timer expired"},
-	{28, "SIGWINCH", "window size changes"},
-	{29, "SIGINFO", "information request"},
-	{30, "SIGUSR1", "user defined signal 1"},
-	{31, "SIGUSR2", "user defined signal 2"},
-}
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.go
deleted file mode 100644
index 48a62e39062..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// go run mksyscall.go -l32 -tags darwin,386,go1.13 syscall_darwin.1_13.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build darwin && 386 && go1.13
-// +build darwin,386,go1.13
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-var _ syscall.Errno
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func closedir(dir uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_closedir_trampoline), uintptr(dir), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_closedir_trampoline()
-
-//go:cgo_import_dynamic libc_closedir closedir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno) {
-	r0, _, _ := syscall_syscall(funcPC(libc_readdir_r_trampoline), uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
-	res = Errno(r0)
-	return
-}
-
-func libc_readdir_r_trampoline()
-
-//go:cgo_import_dynamic libc_readdir_r readdir_r "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.s
deleted file mode 100644
index 1c73a1921d7..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.1_13.s
+++ /dev/null
@@ -1,13 +0,0 @@
-// go run mkasm_darwin.go 386
-// Code generated by the command above; DO NOT EDIT.
-
-//go:build go1.13
-// +build go1.13
-
-#include "textflag.h"
-TEXT ·libc_fdopendir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fdopendir(SB)
-TEXT ·libc_closedir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_closedir(SB)
-TEXT ·libc_readdir_r_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_readdir_r(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.go
deleted file mode 100644
index a266636af67..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.go
+++ /dev/null
@@ -1,2431 +0,0 @@
-// go run mksyscall.go -l32 -tags darwin,386,go1.12 syscall_bsd.go syscall_darwin.go syscall_darwin_386.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build darwin && 386 && go1.12
-// +build darwin,386,go1.12
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-var _ syscall.Errno
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getgroups_trampoline()
-
-//go:cgo_import_dynamic libc_getgroups getgroups "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setgroups(ngid int, gid *_Gid_t) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setgroups_trampoline()
-
-//go:cgo_import_dynamic libc_setgroups setgroups "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_wait4_trampoline), uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
-	wpid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_wait4_trampoline()
-
-//go:cgo_import_dynamic libc_wait4 wait4 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_accept_trampoline), uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_accept_trampoline()
-
-//go:cgo_import_dynamic libc_accept accept "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_bind_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_bind_trampoline()
-
-//go:cgo_import_dynamic libc_bind bind "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_connect_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_connect_trampoline()
-
-//go:cgo_import_dynamic libc_connect connect "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func socket(domain int, typ int, proto int) (fd int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_socket_trampoline), uintptr(domain), uintptr(typ), uintptr(proto))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_socket_trampoline()
-
-//go:cgo_import_dynamic libc_socket socket "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_getsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsockopt_trampoline()
-
-//go:cgo_import_dynamic libc_getsockopt getsockopt "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setsockopt_trampoline()
-
-//go:cgo_import_dynamic libc_setsockopt setsockopt "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getpeername_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpeername_trampoline()
-
-//go:cgo_import_dynamic libc_getpeername getpeername "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getsockname_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsockname_trampoline()
-
-//go:cgo_import_dynamic libc_getsockname getsockname "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Shutdown(s int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_shutdown_trampoline), uintptr(s), uintptr(how), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_shutdown_trampoline()
-
-//go:cgo_import_dynamic libc_shutdown shutdown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func socketpair(domain int, typ int, proto int, fd *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall6(funcPC(libc_socketpair_trampoline), uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_socketpair_trampoline()
-
-//go:cgo_import_dynamic libc_socketpair socketpair "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_recvfrom_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_recvfrom_trampoline()
-
-//go:cgo_import_dynamic libc_recvfrom recvfrom "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendto_trampoline), uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendto_trampoline()
-
-//go:cgo_import_dynamic libc_sendto sendto "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_recvmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_recvmsg_trampoline()
-
-//go:cgo_import_dynamic libc_recvmsg recvmsg "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_sendmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendmsg_trampoline()
-
-//go:cgo_import_dynamic libc_sendmsg sendmsg "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_kevent_trampoline), uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kevent_trampoline()
-
-//go:cgo_import_dynamic libc_kevent kevent "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func utimes(path string, timeval *[2]Timeval) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_utimes_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_utimes_trampoline()
-
-//go:cgo_import_dynamic libc_utimes utimes "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func futimes(fd int, timeval *[2]Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_futimes_trampoline), uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_futimes_trampoline()
-
-//go:cgo_import_dynamic libc_futimes futimes "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_poll_trampoline), uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_poll_trampoline()
-
-//go:cgo_import_dynamic libc_poll poll "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Madvise(b []byte, behav int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_madvise_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(behav))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_madvise_trampoline()
-
-//go:cgo_import_dynamic libc_madvise madvise "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mlock_trampoline()
-
-//go:cgo_import_dynamic libc_mlock mlock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mlockall(flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_mlockall_trampoline), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mlockall_trampoline()
-
-//go:cgo_import_dynamic libc_mlockall mlockall "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mprotect(b []byte, prot int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mprotect_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(prot))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mprotect_trampoline()
-
-//go:cgo_import_dynamic libc_mprotect mprotect "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Msync(b []byte, flags int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_msync_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_msync_trampoline()
-
-//go:cgo_import_dynamic libc_msync msync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_munlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munlock_trampoline()
-
-//go:cgo_import_dynamic libc_munlock munlock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlockall() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munlockall_trampoline), 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munlockall_trampoline()
-
-//go:cgo_import_dynamic libc_munlockall munlockall "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func pipe(p *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_pipe_trampoline), uintptr(unsafe.Pointer(p)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pipe_trampoline()
-
-//go:cgo_import_dynamic libc_pipe pipe "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getxattr(path string, attr string, dest *byte, size int, position uint32, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_getxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getxattr_trampoline()
-
-//go:cgo_import_dynamic libc_getxattr getxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_fgetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fgetxattr_trampoline()
-
-//go:cgo_import_dynamic libc_fgetxattr fgetxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setxattr(path string, attr string, data *byte, size int, position uint32, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_setxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setxattr_trampoline()
-
-//go:cgo_import_dynamic libc_setxattr setxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fsetxattr(fd int, attr string, data *byte, size int, position uint32, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fsetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fsetxattr_trampoline()
-
-//go:cgo_import_dynamic libc_fsetxattr fsetxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func removexattr(path string, attr string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_removexattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_removexattr_trampoline()
-
-//go:cgo_import_dynamic libc_removexattr removexattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fremovexattr(fd int, attr string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_fremovexattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fremovexattr_trampoline()
-
-//go:cgo_import_dynamic libc_fremovexattr fremovexattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func listxattr(path string, dest *byte, size int, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_listxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_listxattr_trampoline()
-
-//go:cgo_import_dynamic libc_listxattr listxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_flistxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_flistxattr_trampoline()
-
-//go:cgo_import_dynamic libc_flistxattr flistxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setattrlist_trampoline), uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setattrlist_trampoline()
-
-//go:cgo_import_dynamic libc_setattrlist setattrlist "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fcntl(fd int, cmd int, arg int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fcntl_trampoline()
-
-//go:cgo_import_dynamic libc_fcntl fcntl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func kill(pid int, signum int, posix int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_kill_trampoline), uintptr(pid), uintptr(signum), uintptr(posix))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kill_trampoline()
-
-//go:cgo_import_dynamic libc_kill kill "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func ioctl(fd int, req uint, arg uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ioctl_trampoline), uintptr(fd), uintptr(req), uintptr(arg))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_ioctl_trampoline()
-
-//go:cgo_import_dynamic libc_ioctl ioctl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) {
-	var _p0 unsafe.Pointer
-	if len(mib) > 0 {
-		_p0 = unsafe.Pointer(&mib[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sysctl_trampoline), uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sysctl_trampoline()
-
-//go:cgo_import_dynamic libc_sysctl sysctl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
-	_, _, e1 := syscall_syscall9(funcPC(libc_sendfile_trampoline), uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(offset>>32), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendfile_trampoline()
-
-//go:cgo_import_dynamic libc_sendfile sendfile "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Access(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_access_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_access_trampoline()
-
-//go:cgo_import_dynamic libc_access access "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Adjtime(delta *Timeval, olddelta *Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_adjtime_trampoline), uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_adjtime_trampoline()
-
-//go:cgo_import_dynamic libc_adjtime adjtime "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chdir(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chdir_trampoline()
-
-//go:cgo_import_dynamic libc_chdir chdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chflags(path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chflags_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chflags_trampoline()
-
-//go:cgo_import_dynamic libc_chflags chflags "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chmod(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chmod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chmod_trampoline()
-
-//go:cgo_import_dynamic libc_chmod chmod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chown(path string, uid int, gid int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chown_trampoline()
-
-//go:cgo_import_dynamic libc_chown chown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chroot(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chroot_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chroot_trampoline()
-
-//go:cgo_import_dynamic libc_chroot chroot "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func ClockGettime(clockid int32, time *Timespec) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_clock_gettime_trampoline), uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clock_gettime_trampoline()
-
-//go:cgo_import_dynamic libc_clock_gettime clock_gettime "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Close(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_close_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_close_trampoline()
-
-//go:cgo_import_dynamic libc_close close "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Clonefile(src string, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(src)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_clonefile_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clonefile_trampoline()
-
-//go:cgo_import_dynamic libc_clonefile clonefile "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Clonefileat(srcDirfd int, src string, dstDirfd int, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(src)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_clonefileat_trampoline), uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clonefileat_trampoline()
-
-//go:cgo_import_dynamic libc_clonefileat clonefileat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_dup_trampoline), uintptr(fd), 0, 0)
-	nfd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_dup_trampoline()
-
-//go:cgo_import_dynamic libc_dup dup "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Dup2(from int, to int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_dup2_trampoline), uintptr(from), uintptr(to), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_dup2_trampoline()
-
-//go:cgo_import_dynamic libc_dup2 dup2 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Exchangedata(path1 string, path2 string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path1)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(path2)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_exchangedata_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_exchangedata_trampoline()
-
-//go:cgo_import_dynamic libc_exchangedata exchangedata "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Exit(code int) {
-	syscall_syscall(funcPC(libc_exit_trampoline), uintptr(code), 0, 0)
-	return
-}
-
-func libc_exit_trampoline()
-
-//go:cgo_import_dynamic libc_exit exit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_faccessat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_faccessat_trampoline()
-
-//go:cgo_import_dynamic libc_faccessat faccessat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchdir(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchdir_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchdir_trampoline()
-
-//go:cgo_import_dynamic libc_fchdir fchdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchflags(fd int, flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchflags_trampoline), uintptr(fd), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchflags_trampoline()
-
-//go:cgo_import_dynamic libc_fchflags fchflags "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchmod(fd int, mode uint32) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchmod_trampoline), uintptr(fd), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchmod_trampoline()
-
-//go:cgo_import_dynamic libc_fchmod fchmod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchmodat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchmodat_trampoline()
-
-//go:cgo_import_dynamic libc_fchmodat fchmodat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchown(fd int, uid int, gid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchown_trampoline), uintptr(fd), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchown_trampoline()
-
-//go:cgo_import_dynamic libc_fchown fchown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchownat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchownat_trampoline()
-
-//go:cgo_import_dynamic libc_fchownat fchownat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fclonefileat(srcDirfd int, dstDirfd int, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fclonefileat_trampoline), uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fclonefileat_trampoline()
-
-//go:cgo_import_dynamic libc_fclonefileat fclonefileat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Flock(fd int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_flock_trampoline), uintptr(fd), uintptr(how), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_flock_trampoline()
-
-//go:cgo_import_dynamic libc_flock flock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fpathconf(fd int, name int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fpathconf_trampoline), uintptr(fd), uintptr(name), 0)
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fpathconf_trampoline()
-
-//go:cgo_import_dynamic libc_fpathconf fpathconf "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fsync(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fsync_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fsync_trampoline()
-
-//go:cgo_import_dynamic libc_fsync fsync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Ftruncate(fd int, length int64) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ftruncate_trampoline), uintptr(fd), uintptr(length), uintptr(length>>32))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_ftruncate_trampoline()
-
-//go:cgo_import_dynamic libc_ftruncate ftruncate "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getcwd(buf []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_getcwd_trampoline), uintptr(_p0), uintptr(len(buf)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getcwd_trampoline()
-
-//go:cgo_import_dynamic libc_getcwd getcwd "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getdtablesize() (size int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_getdtablesize_trampoline), 0, 0, 0)
-	size = int(r0)
-	return
-}
-
-func libc_getdtablesize_trampoline()
-
-//go:cgo_import_dynamic libc_getdtablesize getdtablesize "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getegid() (egid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getegid_trampoline), 0, 0, 0)
-	egid = int(r0)
-	return
-}
-
-func libc_getegid_trampoline()
-
-//go:cgo_import_dynamic libc_getegid getegid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Geteuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_geteuid_trampoline), 0, 0, 0)
-	uid = int(r0)
-	return
-}
-
-func libc_geteuid_trampoline()
-
-//go:cgo_import_dynamic libc_geteuid geteuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getgid() (gid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getgid_trampoline), 0, 0, 0)
-	gid = int(r0)
-	return
-}
-
-func libc_getgid_trampoline()
-
-//go:cgo_import_dynamic libc_getgid getgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpgid(pid int) (pgid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getpgid_trampoline), uintptr(pid), 0, 0)
-	pgid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpgid_trampoline()
-
-//go:cgo_import_dynamic libc_getpgid getpgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpgrp() (pgrp int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpgrp_trampoline), 0, 0, 0)
-	pgrp = int(r0)
-	return
-}
-
-func libc_getpgrp_trampoline()
-
-//go:cgo_import_dynamic libc_getpgrp getpgrp "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpid() (pid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpid_trampoline), 0, 0, 0)
-	pid = int(r0)
-	return
-}
-
-func libc_getpid_trampoline()
-
-//go:cgo_import_dynamic libc_getpid getpid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getppid() (ppid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getppid_trampoline), 0, 0, 0)
-	ppid = int(r0)
-	return
-}
-
-func libc_getppid_trampoline()
-
-//go:cgo_import_dynamic libc_getppid getppid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpriority(which int, who int) (prio int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getpriority_trampoline), uintptr(which), uintptr(who), 0)
-	prio = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpriority_trampoline()
-
-//go:cgo_import_dynamic libc_getpriority getpriority "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getrlimit_trampoline()
-
-//go:cgo_import_dynamic libc_getrlimit getrlimit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getrusage(who int, rusage *Rusage) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrusage_trampoline), uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getrusage_trampoline()
-
-//go:cgo_import_dynamic libc_getrusage getrusage "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getsid(pid int) (sid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getsid_trampoline), uintptr(pid), 0, 0)
-	sid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsid_trampoline()
-
-//go:cgo_import_dynamic libc_getsid getsid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Gettimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_gettimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_gettimeofday_trampoline()
-
-//go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getuid_trampoline), 0, 0, 0)
-	uid = int(r0)
-	return
-}
-
-func libc_getuid_trampoline()
-
-//go:cgo_import_dynamic libc_getuid getuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Issetugid() (tainted bool) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_issetugid_trampoline), 0, 0, 0)
-	tainted = bool(r0 != 0)
-	return
-}
-
-func libc_issetugid_trampoline()
-
-//go:cgo_import_dynamic libc_issetugid issetugid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Kqueue() (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_kqueue_trampoline), 0, 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kqueue_trampoline()
-
-//go:cgo_import_dynamic libc_kqueue kqueue "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Lchown(path string, uid int, gid int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lchown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lchown_trampoline()
-
-//go:cgo_import_dynamic libc_lchown lchown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Link(path string, link string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_link_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_link_trampoline()
-
-//go:cgo_import_dynamic libc_link link "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Linkat(pathfd int, path string, linkfd int, link string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_linkat_trampoline), uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_linkat_trampoline()
-
-//go:cgo_import_dynamic libc_linkat linkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Listen(s int, backlog int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_listen_trampoline), uintptr(s), uintptr(backlog), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_listen_trampoline()
-
-//go:cgo_import_dynamic libc_listen listen "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkdir(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkdir_trampoline()
-
-//go:cgo_import_dynamic libc_mkdir mkdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkdirat(dirfd int, path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdirat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkdirat_trampoline()
-
-//go:cgo_import_dynamic libc_mkdirat mkdirat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkfifo(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkfifo_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkfifo_trampoline()
-
-//go:cgo_import_dynamic libc_mkfifo mkfifo "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mknod(path string, mode uint32, dev int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mknod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mknod_trampoline()
-
-//go:cgo_import_dynamic libc_mknod mknod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Open(path string, mode int, perm uint32) (fd int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_open_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_open_trampoline()
-
-//go:cgo_import_dynamic libc_open open "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_openat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_openat_trampoline()
-
-//go:cgo_import_dynamic libc_openat openat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pathconf(path string, name int) (val int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_pathconf_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pathconf_trampoline()
-
-//go:cgo_import_dynamic libc_pathconf pathconf "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pread(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pread_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pread_trampoline()
-
-//go:cgo_import_dynamic libc_pread pread "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pwrite_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pwrite_trampoline()
-
-//go:cgo_import_dynamic libc_pwrite pwrite "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func read(fd int, p []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_read_trampoline()
-
-//go:cgo_import_dynamic libc_read read "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Readlink(path string, buf []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(buf) > 0 {
-		_p1 = unsafe.Pointer(&buf[0])
-	} else {
-		_p1 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_readlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_readlink_trampoline()
-
-//go:cgo_import_dynamic libc_readlink readlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(buf) > 0 {
-		_p1 = unsafe.Pointer(&buf[0])
-	} else {
-		_p1 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_readlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_readlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_readlinkat readlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Rename(from string, to string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(from)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(to)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rename_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_rename_trampoline()
-
-//go:cgo_import_dynamic libc_rename rename "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Renameat(fromfd int, from string, tofd int, to string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(from)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(to)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_renameat_trampoline), uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_renameat_trampoline()
-
-//go:cgo_import_dynamic libc_renameat renameat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Revoke(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_revoke_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_revoke_trampoline()
-
-//go:cgo_import_dynamic libc_revoke revoke "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Rmdir(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rmdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_rmdir_trampoline()
-
-//go:cgo_import_dynamic libc_rmdir rmdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
-	r0, r1, e1 := syscall_syscall6(funcPC(libc_lseek_trampoline), uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(whence), 0, 0)
-	newoffset = int64(int64(r1)<<32 | int64(r0))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lseek_trampoline()
-
-//go:cgo_import_dynamic libc_lseek lseek "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_select_trampoline), uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_select_trampoline()
-
-//go:cgo_import_dynamic libc_select select "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setegid(egid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setegid_trampoline), uintptr(egid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setegid_trampoline()
-
-//go:cgo_import_dynamic libc_setegid setegid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Seteuid(euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_seteuid_trampoline), uintptr(euid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_seteuid_trampoline()
-
-//go:cgo_import_dynamic libc_seteuid seteuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setgid(gid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgid_trampoline), uintptr(gid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setgid_trampoline()
-
-//go:cgo_import_dynamic libc_setgid setgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setlogin(name string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(name)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_setlogin_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setlogin_trampoline()
-
-//go:cgo_import_dynamic libc_setlogin setlogin "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setpgid(pid int, pgid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setpgid_trampoline), uintptr(pid), uintptr(pgid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setpgid_trampoline()
-
-//go:cgo_import_dynamic libc_setpgid setpgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setpriority(which int, who int, prio int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setpriority_trampoline), uintptr(which), uintptr(who), uintptr(prio))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setpriority_trampoline()
-
-//go:cgo_import_dynamic libc_setpriority setpriority "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setprivexec(flag int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setprivexec_trampoline), uintptr(flag), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setprivexec_trampoline()
-
-//go:cgo_import_dynamic libc_setprivexec setprivexec "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setregid_trampoline), uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setregid_trampoline()
-
-//go:cgo_import_dynamic libc_setregid setregid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setreuid_trampoline), uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setreuid_trampoline()
-
-//go:cgo_import_dynamic libc_setreuid setreuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setrlimit_trampoline()
-
-//go:cgo_import_dynamic libc_setrlimit setrlimit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setsid() (pid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_setsid_trampoline), 0, 0, 0)
-	pid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setsid_trampoline()
-
-//go:cgo_import_dynamic libc_setsid setsid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Settimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_settimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_settimeofday_trampoline()
-
-//go:cgo_import_dynamic libc_settimeofday settimeofday "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setuid(uid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setuid_trampoline), uintptr(uid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setuid_trampoline()
-
-//go:cgo_import_dynamic libc_setuid setuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Symlink(path string, link string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_symlink_trampoline()
-
-//go:cgo_import_dynamic libc_symlink symlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(oldpath)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(newpath)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlinkat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_symlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_symlinkat symlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Sync() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_sync_trampoline), 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sync_trampoline()
-
-//go:cgo_import_dynamic libc_sync sync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Truncate(path string, length int64) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_truncate_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(length), uintptr(length>>32))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_truncate_trampoline()
-
-//go:cgo_import_dynamic libc_truncate truncate "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Umask(newmask int) (oldmask int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_umask_trampoline), uintptr(newmask), 0, 0)
-	oldmask = int(r0)
-	return
-}
-
-func libc_umask_trampoline()
-
-//go:cgo_import_dynamic libc_umask umask "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Undelete(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_undelete_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_undelete_trampoline()
-
-//go:cgo_import_dynamic libc_undelete undelete "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unlink(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlink_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unlink_trampoline()
-
-//go:cgo_import_dynamic libc_unlink unlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unlinkat(dirfd int, path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_unlinkat unlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unmount(path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unmount_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unmount_trampoline()
-
-//go:cgo_import_dynamic libc_unmount unmount "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func write(fd int, p []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_write_trampoline()
-
-//go:cgo_import_dynamic libc_write write "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error) {
-	r0, _, e1 := syscall_syscall9(funcPC(libc_mmap_trampoline), uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos), uintptr(pos>>32), 0, 0)
-	ret = uintptr(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mmap_trampoline()
-
-//go:cgo_import_dynamic libc_mmap mmap "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func munmap(addr uintptr, length uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munmap_trampoline), uintptr(addr), uintptr(length), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munmap_trampoline()
-
-//go:cgo_import_dynamic libc_munmap munmap "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstat(fd int, stat *Stat_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstat64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstat64_trampoline()
-
-//go:cgo_import_dynamic libc_fstat64 fstat64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstatat(fd int, path string, stat *Stat_t, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fstatat64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstatat64_trampoline()
-
-//go:cgo_import_dynamic libc_fstatat64 fstatat64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstatfs(fd int, stat *Statfs_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstatfs64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstatfs64_trampoline()
-
-//go:cgo_import_dynamic libc_fstatfs64 fstatfs64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getfsstat64_trampoline), uintptr(buf), uintptr(size), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getfsstat64_trampoline()
-
-//go:cgo_import_dynamic libc_getfsstat64 getfsstat64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Lstat(path string, stat *Stat_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lstat64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lstat64_trampoline()
-
-//go:cgo_import_dynamic libc_lstat64 lstat64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func ptrace1(request int, pid int, addr uintptr, data uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_ptrace_trampoline), uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_ptrace_trampoline()
-
-//go:cgo_import_dynamic libc_ptrace ptrace "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Stat(path string, stat *Stat_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_stat64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_stat64_trampoline()
-
-//go:cgo_import_dynamic libc_stat64 stat64 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Statfs(path string, stat *Statfs_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_statfs64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_statfs64_trampoline()
-
-//go:cgo_import_dynamic libc_statfs64 statfs64 "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.s
deleted file mode 100644
index 8cc7928d929..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_386.s
+++ /dev/null
@@ -1,291 +0,0 @@
-// go run mkasm_darwin.go 386
-// Code generated by the command above; DO NOT EDIT.
-
-//go:build go1.12
-// +build go1.12
-
-#include "textflag.h"
-TEXT ·libc_getgroups_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getgroups(SB)
-TEXT ·libc_setgroups_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setgroups(SB)
-TEXT ·libc_wait4_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_wait4(SB)
-TEXT ·libc_accept_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_accept(SB)
-TEXT ·libc_bind_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_bind(SB)
-TEXT ·libc_connect_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_connect(SB)
-TEXT ·libc_socket_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_socket(SB)
-TEXT ·libc_getsockopt_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getsockopt(SB)
-TEXT ·libc_setsockopt_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setsockopt(SB)
-TEXT ·libc_getpeername_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getpeername(SB)
-TEXT ·libc_getsockname_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getsockname(SB)
-TEXT ·libc_shutdown_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_shutdown(SB)
-TEXT ·libc_socketpair_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_socketpair(SB)
-TEXT ·libc_recvfrom_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_recvfrom(SB)
-TEXT ·libc_sendto_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sendto(SB)
-TEXT ·libc_recvmsg_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_recvmsg(SB)
-TEXT ·libc_sendmsg_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sendmsg(SB)
-TEXT ·libc_kevent_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_kevent(SB)
-TEXT ·libc_utimes_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_utimes(SB)
-TEXT ·libc_futimes_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_futimes(SB)
-TEXT ·libc_poll_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_poll(SB)
-TEXT ·libc_madvise_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_madvise(SB)
-TEXT ·libc_mlock_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mlock(SB)
-TEXT ·libc_mlockall_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mlockall(SB)
-TEXT ·libc_mprotect_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mprotect(SB)
-TEXT ·libc_msync_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_msync(SB)
-TEXT ·libc_munlock_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_munlock(SB)
-TEXT ·libc_munlockall_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_munlockall(SB)
-TEXT ·libc_pipe_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_pipe(SB)
-TEXT ·libc_getxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getxattr(SB)
-TEXT ·libc_fgetxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fgetxattr(SB)
-TEXT ·libc_setxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setxattr(SB)
-TEXT ·libc_fsetxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fsetxattr(SB)
-TEXT ·libc_removexattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_removexattr(SB)
-TEXT ·libc_fremovexattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fremovexattr(SB)
-TEXT ·libc_listxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_listxattr(SB)
-TEXT ·libc_flistxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_flistxattr(SB)
-TEXT ·libc_setattrlist_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setattrlist(SB)
-TEXT ·libc_fcntl_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fcntl(SB)
-TEXT ·libc_kill_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_kill(SB)
-TEXT ·libc_ioctl_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_ioctl(SB)
-TEXT ·libc_sysctl_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sysctl(SB)
-TEXT ·libc_sendfile_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sendfile(SB)
-TEXT ·libc_access_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_access(SB)
-TEXT ·libc_adjtime_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_adjtime(SB)
-TEXT ·libc_chdir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_chdir(SB)
-TEXT ·libc_chflags_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_chflags(SB)
-TEXT ·libc_chmod_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_chmod(SB)
-TEXT ·libc_chown_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_chown(SB)
-TEXT ·libc_chroot_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_chroot(SB)
-TEXT ·libc_clock_gettime_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clock_gettime(SB)
-TEXT ·libc_close_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_close(SB)
-TEXT ·libc_clonefile_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clonefile(SB)
-TEXT ·libc_clonefileat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clonefileat(SB)
-TEXT ·libc_dup_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_dup(SB)
-TEXT ·libc_dup2_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_dup2(SB)
-TEXT ·libc_exchangedata_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_exchangedata(SB)
-TEXT ·libc_exit_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_exit(SB)
-TEXT ·libc_faccessat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_faccessat(SB)
-TEXT ·libc_fchdir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchdir(SB)
-TEXT ·libc_fchflags_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchflags(SB)
-TEXT ·libc_fchmod_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchmod(SB)
-TEXT ·libc_fchmodat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchmodat(SB)
-TEXT ·libc_fchown_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchown(SB)
-TEXT ·libc_fchownat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchownat(SB)
-TEXT ·libc_fclonefileat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fclonefileat(SB)
-TEXT ·libc_flock_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_flock(SB)
-TEXT ·libc_fpathconf_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fpathconf(SB)
-TEXT ·libc_fsync_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fsync(SB)
-TEXT ·libc_ftruncate_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_ftruncate(SB)
-TEXT ·libc_getcwd_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getcwd(SB)
-TEXT ·libc_getdtablesize_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getdtablesize(SB)
-TEXT ·libc_getegid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getegid(SB)
-TEXT ·libc_geteuid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_geteuid(SB)
-TEXT ·libc_getgid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getgid(SB)
-TEXT ·libc_getpgid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getpgid(SB)
-TEXT ·libc_getpgrp_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getpgrp(SB)
-TEXT ·libc_getpid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getpid(SB)
-TEXT ·libc_getppid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getppid(SB)
-TEXT ·libc_getpriority_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getpriority(SB)
-TEXT ·libc_getrlimit_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getrlimit(SB)
-TEXT ·libc_getrusage_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getrusage(SB)
-TEXT ·libc_getsid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getsid(SB)
-TEXT ·libc_gettimeofday_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_gettimeofday(SB)
-TEXT ·libc_getuid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getuid(SB)
-TEXT ·libc_issetugid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_issetugid(SB)
-TEXT ·libc_kqueue_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_kqueue(SB)
-TEXT ·libc_lchown_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_lchown(SB)
-TEXT ·libc_link_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_link(SB)
-TEXT ·libc_linkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_linkat(SB)
-TEXT ·libc_listen_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_listen(SB)
-TEXT ·libc_mkdir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mkdir(SB)
-TEXT ·libc_mkdirat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mkdirat(SB)
-TEXT ·libc_mkfifo_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mkfifo(SB)
-TEXT ·libc_mknod_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mknod(SB)
-TEXT ·libc_open_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_open(SB)
-TEXT ·libc_openat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_openat(SB)
-TEXT ·libc_pathconf_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_pathconf(SB)
-TEXT ·libc_pread_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_pread(SB)
-TEXT ·libc_pwrite_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_pwrite(SB)
-TEXT ·libc_read_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_read(SB)
-TEXT ·libc_readlink_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_readlink(SB)
-TEXT ·libc_readlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_readlinkat(SB)
-TEXT ·libc_rename_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_rename(SB)
-TEXT ·libc_renameat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_renameat(SB)
-TEXT ·libc_revoke_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_revoke(SB)
-TEXT ·libc_rmdir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_rmdir(SB)
-TEXT ·libc_lseek_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_lseek(SB)
-TEXT ·libc_select_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_select(SB)
-TEXT ·libc_setegid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setegid(SB)
-TEXT ·libc_seteuid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_seteuid(SB)
-TEXT ·libc_setgid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setgid(SB)
-TEXT ·libc_setlogin_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setlogin(SB)
-TEXT ·libc_setpgid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setpgid(SB)
-TEXT ·libc_setpriority_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setpriority(SB)
-TEXT ·libc_setprivexec_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setprivexec(SB)
-TEXT ·libc_setregid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setregid(SB)
-TEXT ·libc_setreuid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setreuid(SB)
-TEXT ·libc_setrlimit_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setrlimit(SB)
-TEXT ·libc_setsid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setsid(SB)
-TEXT ·libc_settimeofday_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_settimeofday(SB)
-TEXT ·libc_setuid_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setuid(SB)
-TEXT ·libc_symlink_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_symlink(SB)
-TEXT ·libc_symlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_symlinkat(SB)
-TEXT ·libc_sync_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sync(SB)
-TEXT ·libc_truncate_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_truncate(SB)
-TEXT ·libc_umask_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_umask(SB)
-TEXT ·libc_undelete_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_undelete(SB)
-TEXT ·libc_unlink_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_unlink(SB)
-TEXT ·libc_unlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_unlinkat(SB)
-TEXT ·libc_unmount_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_unmount(SB)
-TEXT ·libc_write_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_write(SB)
-TEXT ·libc_mmap_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mmap(SB)
-TEXT ·libc_munmap_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_munmap(SB)
-TEXT ·libc_fstat64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fstat64(SB)
-TEXT ·libc_fstatat64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fstatat64(SB)
-TEXT ·libc_fstatfs64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fstatfs64(SB)
-TEXT ·libc_getfsstat64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getfsstat64(SB)
-TEXT ·libc_lstat64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_lstat64(SB)
-TEXT ·libc_ptrace_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_ptrace(SB)
-TEXT ·libc_stat64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_stat64(SB)
-TEXT ·libc_statfs64_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_statfs64(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.go
index e36299ead09..a06eb093242 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.go
@@ -16,25 +16,25 @@ var _ syscall.Errno
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func closedir(dir uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_closedir_trampoline), uintptr(dir), 0, 0)
+	_, _, e1 := syscall_syscall(libc_closedir_trampoline_addr, uintptr(dir), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_closedir_trampoline()
+var libc_closedir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_closedir closedir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno) {
-	r0, _, _ := syscall_syscall(funcPC(libc_readdir_r_trampoline), uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
+	r0, _, _ := syscall_syscall(libc_readdir_r_trampoline_addr, uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
 	res = Errno(r0)
 	return
 }
 
-func libc_readdir_r_trampoline()
+var libc_readdir_r_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readdir_r readdir_r "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.s
index ab59833fcd2..d6c3e25c018 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.s
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.1_13.s
@@ -5,9 +5,21 @@
 // +build go1.13
 
 #include "textflag.h"
-TEXT ·libc_fdopendir_trampoline(SB),NOSPLIT,$0-0
+
+TEXT libc_fdopendir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fdopendir(SB)
-TEXT ·libc_closedir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fdopendir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fdopendir_trampoline_addr(SB)/8, $libc_fdopendir_trampoline<>(SB)
+
+TEXT libc_closedir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_closedir(SB)
-TEXT ·libc_readdir_r_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_closedir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_closedir_trampoline_addr(SB)/8, $libc_closedir_trampoline<>(SB)
+
+TEXT libc_readdir_r_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readdir_r(SB)
+
+GLOBL	·libc_readdir_r_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readdir_r_trampoline_addr(SB)/8, $libc_readdir_r_trampoline<>(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.go
index f4111628823..d4efe8d457a 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.go
@@ -16,7 +16,7 @@ var _ syscall.Errno
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getgroups_trampoline_addr, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -24,28 +24,28 @@ func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
 	return
 }
 
-func libc_getgroups_trampoline()
+var libc_getgroups_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getgroups getgroups "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setgroups(ngid int, gid *_Gid_t) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setgroups_trampoline_addr, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setgroups_trampoline()
+var libc_setgroups_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setgroups setgroups "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_wait4_trampoline), uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_wait4_trampoline_addr, uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
 	wpid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -53,14 +53,14 @@ func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err
 	return
 }
 
-func libc_wait4_trampoline()
+var libc_wait4_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_wait4 wait4 "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_accept_trampoline), uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	r0, _, e1 := syscall_syscall(libc_accept_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -68,42 +68,42 @@ func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
 	return
 }
 
-func libc_accept_trampoline()
+var libc_accept_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_accept accept "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_bind_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall_syscall(libc_bind_trampoline_addr, uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_bind_trampoline()
+var libc_bind_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_bind bind "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_connect_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall_syscall(libc_connect_trampoline_addr, uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_connect_trampoline()
+var libc_connect_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_connect connect "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socket(domain int, typ int, proto int) (fd int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_socket_trampoline), uintptr(domain), uintptr(typ), uintptr(proto))
+	r0, _, e1 := syscall_rawSyscall(libc_socket_trampoline_addr, uintptr(domain), uintptr(typ), uintptr(proto))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -111,91 +111,91 @@ func socket(domain int, typ int, proto int) (fd int, err error) {
 	return
 }
 
-func libc_socket_trampoline()
+var libc_socket_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_socket socket "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_getsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
+	_, _, e1 := syscall_syscall6(libc_getsockopt_trampoline_addr, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getsockopt_trampoline()
+var libc_getsockopt_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsockopt getsockopt "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
+	_, _, e1 := syscall_syscall6(libc_setsockopt_trampoline_addr, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setsockopt_trampoline()
+var libc_setsockopt_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setsockopt setsockopt "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getpeername_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := syscall_rawSyscall(libc_getpeername_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getpeername_trampoline()
+var libc_getpeername_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpeername getpeername "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getsockname_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := syscall_rawSyscall(libc_getsockname_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getsockname_trampoline()
+var libc_getsockname_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsockname getsockname "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Shutdown(s int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_shutdown_trampoline), uintptr(s), uintptr(how), 0)
+	_, _, e1 := syscall_syscall(libc_shutdown_trampoline_addr, uintptr(s), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_shutdown_trampoline()
+var libc_shutdown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_shutdown shutdown "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socketpair(domain int, typ int, proto int, fd *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall6(funcPC(libc_socketpair_trampoline), uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
+	_, _, e1 := syscall_rawSyscall6(libc_socketpair_trampoline_addr, uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_socketpair_trampoline()
+var libc_socketpair_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_socketpair socketpair "/usr/lib/libSystem.B.dylib"
 
@@ -208,7 +208,7 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_recvfrom_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
+	r0, _, e1 := syscall_syscall6(libc_recvfrom_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -216,7 +216,7 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	return
 }
 
-func libc_recvfrom_trampoline()
+var libc_recvfrom_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_recvfrom recvfrom "/usr/lib/libSystem.B.dylib"
 
@@ -229,21 +229,21 @@ func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendto_trampoline), uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
+	_, _, e1 := syscall_syscall6(libc_sendto_trampoline_addr, uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sendto_trampoline()
+var libc_sendto_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendto sendto "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_recvmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_recvmsg_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -251,14 +251,14 @@ func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
-func libc_recvmsg_trampoline()
+var libc_recvmsg_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_recvmsg recvmsg "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_sendmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_sendmsg_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -266,14 +266,14 @@ func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
-func libc_sendmsg_trampoline()
+var libc_sendmsg_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendmsg sendmsg "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_kevent_trampoline), uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
+	r0, _, e1 := syscall_syscall6(libc_kevent_trampoline_addr, uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -281,7 +281,7 @@ func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, ne
 	return
 }
 
-func libc_kevent_trampoline()
+var libc_kevent_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kevent kevent "/usr/lib/libSystem.B.dylib"
 
@@ -293,35 +293,35 @@ func utimes(path string, timeval *[2]Timeval) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_utimes_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall_syscall(libc_utimes_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_utimes_trampoline()
+var libc_utimes_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_utimes utimes "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func futimes(fd int, timeval *[2]Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_futimes_trampoline), uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall_syscall(libc_futimes_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_futimes_trampoline()
+var libc_futimes_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_futimes futimes "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_poll_trampoline), uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
+	r0, _, e1 := syscall_syscall(libc_poll_trampoline_addr, uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -329,7 +329,7 @@ func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
 	return
 }
 
-func libc_poll_trampoline()
+var libc_poll_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_poll poll "/usr/lib/libSystem.B.dylib"
 
@@ -342,14 +342,14 @@ func Madvise(b []byte, behav int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_madvise_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(behav))
+	_, _, e1 := syscall_syscall(libc_madvise_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(behav))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_madvise_trampoline()
+var libc_madvise_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_madvise madvise "/usr/lib/libSystem.B.dylib"
 
@@ -362,28 +362,28 @@ func Mlock(b []byte) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
+	_, _, e1 := syscall_syscall(libc_mlock_trampoline_addr, uintptr(_p0), uintptr(len(b)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mlock_trampoline()
+var libc_mlock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mlock mlock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Mlockall(flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_mlockall_trampoline), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall(libc_mlockall_trampoline_addr, uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mlockall_trampoline()
+var libc_mlockall_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mlockall mlockall "/usr/lib/libSystem.B.dylib"
 
@@ -396,14 +396,14 @@ func Mprotect(b []byte, prot int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mprotect_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(prot))
+	_, _, e1 := syscall_syscall(libc_mprotect_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(prot))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mprotect_trampoline()
+var libc_mprotect_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mprotect mprotect "/usr/lib/libSystem.B.dylib"
 
@@ -416,14 +416,14 @@ func Msync(b []byte, flags int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_msync_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_msync_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_msync_trampoline()
+var libc_msync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_msync msync "/usr/lib/libSystem.B.dylib"
 
@@ -436,42 +436,42 @@ func Munlock(b []byte) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_munlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
+	_, _, e1 := syscall_syscall(libc_munlock_trampoline_addr, uintptr(_p0), uintptr(len(b)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munlock_trampoline()
+var libc_munlock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munlock munlock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Munlockall() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munlockall_trampoline), 0, 0, 0)
+	_, _, e1 := syscall_syscall(libc_munlockall_trampoline_addr, 0, 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munlockall_trampoline()
+var libc_munlockall_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munlockall munlockall "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func pipe(p *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_pipe_trampoline), uintptr(unsafe.Pointer(p)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_pipe_trampoline_addr, uintptr(unsafe.Pointer(p)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_pipe_trampoline()
+var libc_pipe_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pipe pipe "/usr/lib/libSystem.B.dylib"
 
@@ -488,7 +488,7 @@ func getxattr(path string, attr string, dest *byte, size int, position uint32, o
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_getxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
+	r0, _, e1 := syscall_syscall6(libc_getxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -496,7 +496,7 @@ func getxattr(path string, attr string, dest *byte, size int, position uint32, o
 	return
 }
 
-func libc_getxattr_trampoline()
+var libc_getxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getxattr getxattr "/usr/lib/libSystem.B.dylib"
 
@@ -508,7 +508,7 @@ func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, optio
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_fgetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
+	r0, _, e1 := syscall_syscall6(libc_fgetxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -516,7 +516,7 @@ func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, optio
 	return
 }
 
-func libc_fgetxattr_trampoline()
+var libc_fgetxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fgetxattr fgetxattr "/usr/lib/libSystem.B.dylib"
 
@@ -533,14 +533,14 @@ func setxattr(path string, attr string, data *byte, size int, position uint32, o
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_setxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
+	_, _, e1 := syscall_syscall6(libc_setxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setxattr_trampoline()
+var libc_setxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setxattr setxattr "/usr/lib/libSystem.B.dylib"
 
@@ -552,14 +552,14 @@ func fsetxattr(fd int, attr string, data *byte, size int, position uint32, optio
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fsetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
+	_, _, e1 := syscall_syscall6(libc_fsetxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fsetxattr_trampoline()
+var libc_fsetxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fsetxattr fsetxattr "/usr/lib/libSystem.B.dylib"
 
@@ -576,14 +576,14 @@ func removexattr(path string, attr string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_removexattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_removexattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_removexattr_trampoline()
+var libc_removexattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_removexattr removexattr "/usr/lib/libSystem.B.dylib"
 
@@ -595,14 +595,14 @@ func fremovexattr(fd int, attr string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_fremovexattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_fremovexattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fremovexattr_trampoline()
+var libc_fremovexattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fremovexattr fremovexattr "/usr/lib/libSystem.B.dylib"
 
@@ -614,7 +614,7 @@ func listxattr(path string, dest *byte, size int, options int) (sz int, err erro
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_listxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_listxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -622,14 +622,14 @@ func listxattr(path string, dest *byte, size int, options int) (sz int, err erro
 	return
 }
 
-func libc_listxattr_trampoline()
+var libc_listxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_listxattr listxattr "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_flistxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_flistxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -637,28 +637,28 @@ func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
 	return
 }
 
-func libc_flistxattr_trampoline()
+var libc_flistxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_flistxattr flistxattr "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setattrlist_trampoline), uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
+	_, _, e1 := syscall_syscall6(libc_setattrlist_trampoline_addr, uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setattrlist_trampoline()
+var libc_setattrlist_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setattrlist setattrlist "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func fcntl(fd int, cmd int, arg int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
+	r0, _, e1 := syscall_syscall(libc_fcntl_trampoline_addr, uintptr(fd), uintptr(cmd), uintptr(arg))
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -666,35 +666,35 @@ func fcntl(fd int, cmd int, arg int) (val int, err error) {
 	return
 }
 
-func libc_fcntl_trampoline()
+var libc_fcntl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fcntl fcntl "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func kill(pid int, signum int, posix int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_kill_trampoline), uintptr(pid), uintptr(signum), uintptr(posix))
+	_, _, e1 := syscall_syscall(libc_kill_trampoline_addr, uintptr(pid), uintptr(signum), uintptr(posix))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_kill_trampoline()
+var libc_kill_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kill kill "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ioctl(fd int, req uint, arg uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ioctl_trampoline), uintptr(fd), uintptr(req), uintptr(arg))
+	_, _, e1 := syscall_syscall(libc_ioctl_trampoline_addr, uintptr(fd), uintptr(req), uintptr(arg))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ioctl_trampoline()
+var libc_ioctl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ioctl ioctl "/usr/lib/libSystem.B.dylib"
 
@@ -707,28 +707,28 @@ func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr)
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sysctl_trampoline), uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
+	_, _, e1 := syscall_syscall6(libc_sysctl_trampoline_addr, uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sysctl_trampoline()
+var libc_sysctl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sysctl sysctl "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendfile_trampoline), uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
+	_, _, e1 := syscall_syscall6(libc_sendfile_trampoline_addr, uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sendfile_trampoline()
+var libc_sendfile_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendfile sendfile "/usr/lib/libSystem.B.dylib"
 
@@ -740,28 +740,28 @@ func Access(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_access_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_access_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_access_trampoline()
+var libc_access_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_access access "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Adjtime(delta *Timeval, olddelta *Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_adjtime_trampoline), uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
+	_, _, e1 := syscall_syscall(libc_adjtime_trampoline_addr, uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_adjtime_trampoline()
+var libc_adjtime_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_adjtime adjtime "/usr/lib/libSystem.B.dylib"
 
@@ -773,14 +773,14 @@ func Chdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_chdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chdir_trampoline()
+var libc_chdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chdir chdir "/usr/lib/libSystem.B.dylib"
 
@@ -792,14 +792,14 @@ func Chflags(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chflags_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_chflags_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chflags_trampoline()
+var libc_chflags_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chflags chflags "/usr/lib/libSystem.B.dylib"
 
@@ -811,14 +811,14 @@ func Chmod(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chmod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_chmod_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chmod_trampoline()
+var libc_chmod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chmod chmod "/usr/lib/libSystem.B.dylib"
 
@@ -830,14 +830,14 @@ func Chown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_chown_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chown_trampoline()
+var libc_chown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chown chown "/usr/lib/libSystem.B.dylib"
 
@@ -849,42 +849,42 @@ func Chroot(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chroot_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_chroot_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chroot_trampoline()
+var libc_chroot_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chroot chroot "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ClockGettime(clockid int32, time *Timespec) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_clock_gettime_trampoline), uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
+	_, _, e1 := syscall_syscall(libc_clock_gettime_trampoline_addr, uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clock_gettime_trampoline()
+var libc_clock_gettime_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clock_gettime clock_gettime "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Close(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_close_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_close_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_close_trampoline()
+var libc_close_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_close close "/usr/lib/libSystem.B.dylib"
 
@@ -901,14 +901,14 @@ func Clonefile(src string, dst string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_clonefile_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_clonefile_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clonefile_trampoline()
+var libc_clonefile_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clonefile clonefile "/usr/lib/libSystem.B.dylib"
 
@@ -925,21 +925,21 @@ func Clonefileat(srcDirfd int, src string, dstDirfd int, dst string, flags int)
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_clonefileat_trampoline), uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_clonefileat_trampoline_addr, uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clonefileat_trampoline()
+var libc_clonefileat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clonefileat clonefileat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_dup_trampoline), uintptr(fd), 0, 0)
+	r0, _, e1 := syscall_syscall(libc_dup_trampoline_addr, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -947,21 +947,21 @@ func Dup(fd int) (nfd int, err error) {
 	return
 }
 
-func libc_dup_trampoline()
+var libc_dup_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_dup dup "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_dup2_trampoline), uintptr(from), uintptr(to), 0)
+	_, _, e1 := syscall_syscall(libc_dup2_trampoline_addr, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_dup2_trampoline()
+var libc_dup2_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_dup2 dup2 "/usr/lib/libSystem.B.dylib"
 
@@ -978,25 +978,25 @@ func Exchangedata(path1 string, path2 string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_exchangedata_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_exchangedata_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_exchangedata_trampoline()
+var libc_exchangedata_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_exchangedata exchangedata "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Exit(code int) {
-	syscall_syscall(funcPC(libc_exit_trampoline), uintptr(code), 0, 0)
+	syscall_syscall(libc_exit_trampoline_addr, uintptr(code), 0, 0)
 	return
 }
 
-func libc_exit_trampoline()
+var libc_exit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_exit exit "/usr/lib/libSystem.B.dylib"
 
@@ -1008,56 +1008,56 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_faccessat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_faccessat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_faccessat_trampoline()
+var libc_faccessat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_faccessat faccessat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchdir(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchdir_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_fchdir_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchdir_trampoline()
+var libc_fchdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchdir fchdir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchflags(fd int, flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchflags_trampoline), uintptr(fd), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_fchflags_trampoline_addr, uintptr(fd), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchflags_trampoline()
+var libc_fchflags_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchflags fchflags "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchmod(fd int, mode uint32) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchmod_trampoline), uintptr(fd), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_fchmod_trampoline_addr, uintptr(fd), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchmod_trampoline()
+var libc_fchmod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchmod fchmod "/usr/lib/libSystem.B.dylib"
 
@@ -1069,28 +1069,28 @@ func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchmodat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fchmodat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchmodat_trampoline()
+var libc_fchmodat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchmodat fchmodat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchown(fd int, uid int, gid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchown_trampoline), uintptr(fd), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_fchown_trampoline_addr, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchown_trampoline()
+var libc_fchown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchown fchown "/usr/lib/libSystem.B.dylib"
 
@@ -1102,14 +1102,14 @@ func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchownat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_fchownat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchownat_trampoline()
+var libc_fchownat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchownat fchownat "/usr/lib/libSystem.B.dylib"
 
@@ -1121,35 +1121,35 @@ func Fclonefileat(srcDirfd int, dstDirfd int, dst string, flags int) (err error)
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fclonefileat_trampoline), uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fclonefileat_trampoline_addr, uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fclonefileat_trampoline()
+var libc_fclonefileat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fclonefileat fclonefileat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Flock(fd int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_flock_trampoline), uintptr(fd), uintptr(how), 0)
+	_, _, e1 := syscall_syscall(libc_flock_trampoline_addr, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_flock_trampoline()
+var libc_flock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_flock flock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fpathconf(fd int, name int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fpathconf_trampoline), uintptr(fd), uintptr(name), 0)
+	r0, _, e1 := syscall_syscall(libc_fpathconf_trampoline_addr, uintptr(fd), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1157,35 +1157,35 @@ func Fpathconf(fd int, name int) (val int, err error) {
 	return
 }
 
-func libc_fpathconf_trampoline()
+var libc_fpathconf_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fpathconf fpathconf "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fsync(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fsync_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_fsync_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fsync_trampoline()
+var libc_fsync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fsync fsync "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Ftruncate(fd int, length int64) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ftruncate_trampoline), uintptr(fd), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_ftruncate_trampoline_addr, uintptr(fd), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ftruncate_trampoline()
+var libc_ftruncate_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ftruncate ftruncate "/usr/lib/libSystem.B.dylib"
 
@@ -1198,7 +1198,7 @@ func Getcwd(buf []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_getcwd_trampoline), uintptr(_p0), uintptr(len(buf)), 0)
+	r0, _, e1 := syscall_syscall(libc_getcwd_trampoline_addr, uintptr(_p0), uintptr(len(buf)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1206,62 +1206,62 @@ func Getcwd(buf []byte) (n int, err error) {
 	return
 }
 
-func libc_getcwd_trampoline()
+var libc_getcwd_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getcwd getcwd "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getdtablesize() (size int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_getdtablesize_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_syscall(libc_getdtablesize_trampoline_addr, 0, 0, 0)
 	size = int(r0)
 	return
 }
 
-func libc_getdtablesize_trampoline()
+var libc_getdtablesize_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getdtablesize getdtablesize "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getegid() (egid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getegid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getegid_trampoline_addr, 0, 0, 0)
 	egid = int(r0)
 	return
 }
 
-func libc_getegid_trampoline()
+var libc_getegid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getegid getegid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Geteuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_geteuid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_geteuid_trampoline_addr, 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
-func libc_geteuid_trampoline()
+var libc_geteuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_geteuid geteuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getgid() (gid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getgid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getgid_trampoline_addr, 0, 0, 0)
 	gid = int(r0)
 	return
 }
 
-func libc_getgid_trampoline()
+var libc_getgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getgid getgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgid(pid int) (pgid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getpgid_trampoline), uintptr(pid), 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getpgid_trampoline_addr, uintptr(pid), 0, 0)
 	pgid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1269,50 +1269,50 @@ func Getpgid(pid int) (pgid int, err error) {
 	return
 }
 
-func libc_getpgid_trampoline()
+var libc_getpgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpgid getpgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgrp() (pgrp int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpgrp_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getpgrp_trampoline_addr, 0, 0, 0)
 	pgrp = int(r0)
 	return
 }
 
-func libc_getpgrp_trampoline()
+var libc_getpgrp_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpgrp getpgrp "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpid() (pid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getpid_trampoline_addr, 0, 0, 0)
 	pid = int(r0)
 	return
 }
 
-func libc_getpid_trampoline()
+var libc_getpid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpid getpid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getppid() (ppid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getppid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getppid_trampoline_addr, 0, 0, 0)
 	ppid = int(r0)
 	return
 }
 
-func libc_getppid_trampoline()
+var libc_getppid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getppid getppid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpriority(which int, who int) (prio int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getpriority_trampoline), uintptr(which), uintptr(who), 0)
+	r0, _, e1 := syscall_syscall(libc_getpriority_trampoline_addr, uintptr(which), uintptr(who), 0)
 	prio = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1320,42 +1320,42 @@ func Getpriority(which int, who int) (prio int, err error) {
 	return
 }
 
-func libc_getpriority_trampoline()
+var libc_getpriority_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpriority getpriority "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_getrlimit_trampoline_addr, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getrlimit_trampoline()
+var libc_getrlimit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getrlimit getrlimit "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrusage(who int, rusage *Rusage) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrusage_trampoline), uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_getrusage_trampoline_addr, uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getrusage_trampoline()
+var libc_getrusage_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getrusage getrusage "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getsid(pid int) (sid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getsid_trampoline), uintptr(pid), 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getsid_trampoline_addr, uintptr(pid), 0, 0)
 	sid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1363,52 +1363,52 @@ func Getsid(pid int) (sid int, err error) {
 	return
 }
 
-func libc_getsid_trampoline()
+var libc_getsid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsid getsid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Gettimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_gettimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_gettimeofday_trampoline_addr, uintptr(unsafe.Pointer(tp)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_gettimeofday_trampoline()
+var libc_gettimeofday_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getuid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getuid_trampoline_addr, 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
-func libc_getuid_trampoline()
+var libc_getuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getuid getuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Issetugid() (tainted bool) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_issetugid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_issetugid_trampoline_addr, 0, 0, 0)
 	tainted = bool(r0 != 0)
 	return
 }
 
-func libc_issetugid_trampoline()
+var libc_issetugid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_issetugid issetugid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Kqueue() (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_kqueue_trampoline), 0, 0, 0)
+	r0, _, e1 := syscall_syscall(libc_kqueue_trampoline_addr, 0, 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1416,7 +1416,7 @@ func Kqueue() (fd int, err error) {
 	return
 }
 
-func libc_kqueue_trampoline()
+var libc_kqueue_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kqueue kqueue "/usr/lib/libSystem.B.dylib"
 
@@ -1428,14 +1428,14 @@ func Lchown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lchown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_lchown_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_lchown_trampoline()
+var libc_lchown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lchown lchown "/usr/lib/libSystem.B.dylib"
 
@@ -1452,14 +1452,14 @@ func Link(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_link_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_link_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_link_trampoline()
+var libc_link_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_link link "/usr/lib/libSystem.B.dylib"
 
@@ -1476,28 +1476,28 @@ func Linkat(pathfd int, path string, linkfd int, link string, flags int) (err er
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_linkat_trampoline), uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_linkat_trampoline_addr, uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_linkat_trampoline()
+var libc_linkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_linkat linkat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Listen(s int, backlog int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_listen_trampoline), uintptr(s), uintptr(backlog), 0)
+	_, _, e1 := syscall_syscall(libc_listen_trampoline_addr, uintptr(s), uintptr(backlog), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_listen_trampoline()
+var libc_listen_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_listen listen "/usr/lib/libSystem.B.dylib"
 
@@ -1509,14 +1509,14 @@ func Mkdir(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_mkdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkdir_trampoline()
+var libc_mkdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkdir mkdir "/usr/lib/libSystem.B.dylib"
 
@@ -1528,14 +1528,14 @@ func Mkdirat(dirfd int, path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdirat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	_, _, e1 := syscall_syscall(libc_mkdirat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkdirat_trampoline()
+var libc_mkdirat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkdirat mkdirat "/usr/lib/libSystem.B.dylib"
 
@@ -1547,14 +1547,14 @@ func Mkfifo(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkfifo_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_mkfifo_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkfifo_trampoline()
+var libc_mkfifo_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkfifo mkfifo "/usr/lib/libSystem.B.dylib"
 
@@ -1566,14 +1566,14 @@ func Mknod(path string, mode uint32, dev int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mknod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
+	_, _, e1 := syscall_syscall(libc_mknod_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mknod_trampoline()
+var libc_mknod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mknod mknod "/usr/lib/libSystem.B.dylib"
 
@@ -1585,7 +1585,7 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_open_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
+	r0, _, e1 := syscall_syscall(libc_open_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1593,7 +1593,7 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	return
 }
 
-func libc_open_trampoline()
+var libc_open_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_open open "/usr/lib/libSystem.B.dylib"
 
@@ -1605,7 +1605,7 @@ func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_openat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_openat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1613,7 +1613,7 @@ func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
 	return
 }
 
-func libc_openat_trampoline()
+var libc_openat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_openat openat "/usr/lib/libSystem.B.dylib"
 
@@ -1625,7 +1625,7 @@ func Pathconf(path string, name int) (val int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_pathconf_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
+	r0, _, e1 := syscall_syscall(libc_pathconf_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1633,7 +1633,7 @@ func Pathconf(path string, name int) (val int, err error) {
 	return
 }
 
-func libc_pathconf_trampoline()
+var libc_pathconf_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pathconf pathconf "/usr/lib/libSystem.B.dylib"
 
@@ -1646,7 +1646,7 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pread_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_pread_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1654,7 +1654,7 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
-func libc_pread_trampoline()
+var libc_pread_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pread pread "/usr/lib/libSystem.B.dylib"
 
@@ -1667,7 +1667,7 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pwrite_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_pwrite_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1675,7 +1675,7 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
-func libc_pwrite_trampoline()
+var libc_pwrite_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pwrite pwrite "/usr/lib/libSystem.B.dylib"
 
@@ -1688,7 +1688,7 @@ func read(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall_syscall(libc_read_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1696,7 +1696,7 @@ func read(fd int, p []byte) (n int, err error) {
 	return
 }
 
-func libc_read_trampoline()
+var libc_read_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_read read "/usr/lib/libSystem.B.dylib"
 
@@ -1714,7 +1714,7 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	} else {
 		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_readlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
+	r0, _, e1 := syscall_syscall(libc_readlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1722,7 +1722,7 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	return
 }
 
-func libc_readlink_trampoline()
+var libc_readlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readlink readlink "/usr/lib/libSystem.B.dylib"
 
@@ -1740,7 +1740,7 @@ func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
 	} else {
 		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_readlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_readlinkat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1748,7 +1748,7 @@ func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
 	return
 }
 
-func libc_readlinkat_trampoline()
+var libc_readlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readlinkat readlinkat "/usr/lib/libSystem.B.dylib"
 
@@ -1765,14 +1765,14 @@ func Rename(from string, to string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rename_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_rename_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_rename_trampoline()
+var libc_rename_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_rename rename "/usr/lib/libSystem.B.dylib"
 
@@ -1789,14 +1789,14 @@ func Renameat(fromfd int, from string, tofd int, to string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_renameat_trampoline), uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_renameat_trampoline_addr, uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_renameat_trampoline()
+var libc_renameat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_renameat renameat "/usr/lib/libSystem.B.dylib"
 
@@ -1808,14 +1808,14 @@ func Revoke(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_revoke_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_revoke_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_revoke_trampoline()
+var libc_revoke_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_revoke revoke "/usr/lib/libSystem.B.dylib"
 
@@ -1827,21 +1827,21 @@ func Rmdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rmdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_rmdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_rmdir_trampoline()
+var libc_rmdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_rmdir rmdir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_lseek_trampoline), uintptr(fd), uintptr(offset), uintptr(whence))
+	r0, _, e1 := syscall_syscall(libc_lseek_trampoline_addr, uintptr(fd), uintptr(offset), uintptr(whence))
 	newoffset = int64(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1849,14 +1849,14 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 	return
 }
 
-func libc_lseek_trampoline()
+var libc_lseek_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lseek lseek "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_select_trampoline), uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
+	r0, _, e1 := syscall_syscall6(libc_select_trampoline_addr, uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1864,49 +1864,49 @@ func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err
 	return
 }
 
-func libc_select_trampoline()
+var libc_select_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_select select "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setegid(egid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setegid_trampoline), uintptr(egid), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setegid_trampoline_addr, uintptr(egid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setegid_trampoline()
+var libc_setegid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setegid setegid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Seteuid(euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_seteuid_trampoline), uintptr(euid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_seteuid_trampoline_addr, uintptr(euid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_seteuid_trampoline()
+var libc_seteuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_seteuid seteuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setgid(gid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgid_trampoline), uintptr(gid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_setgid_trampoline_addr, uintptr(gid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setgid_trampoline()
+var libc_setgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setgid setgid "/usr/lib/libSystem.B.dylib"
 
@@ -1918,105 +1918,105 @@ func Setlogin(name string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_setlogin_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setlogin_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setlogin_trampoline()
+var libc_setlogin_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setlogin setlogin "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpgid(pid int, pgid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setpgid_trampoline), uintptr(pid), uintptr(pgid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setpgid_trampoline_addr, uintptr(pid), uintptr(pgid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setpgid_trampoline()
+var libc_setpgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setpgid setpgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpriority(which int, who int, prio int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setpriority_trampoline), uintptr(which), uintptr(who), uintptr(prio))
+	_, _, e1 := syscall_syscall(libc_setpriority_trampoline_addr, uintptr(which), uintptr(who), uintptr(prio))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setpriority_trampoline()
+var libc_setpriority_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setpriority setpriority "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setprivexec(flag int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setprivexec_trampoline), uintptr(flag), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setprivexec_trampoline_addr, uintptr(flag), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setprivexec_trampoline()
+var libc_setprivexec_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setprivexec setprivexec "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setregid_trampoline), uintptr(rgid), uintptr(egid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setregid_trampoline_addr, uintptr(rgid), uintptr(egid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setregid_trampoline()
+var libc_setregid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setregid setregid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setreuid_trampoline), uintptr(ruid), uintptr(euid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setreuid_trampoline_addr, uintptr(ruid), uintptr(euid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setreuid_trampoline()
+var libc_setreuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setreuid setreuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setrlimit_trampoline_addr, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setrlimit_trampoline()
+var libc_setrlimit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setrlimit setrlimit "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setsid() (pid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_setsid_trampoline), 0, 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_setsid_trampoline_addr, 0, 0, 0)
 	pid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2024,35 +2024,35 @@ func Setsid() (pid int, err error) {
 	return
 }
 
-func libc_setsid_trampoline()
+var libc_setsid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setsid setsid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Settimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_settimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_settimeofday_trampoline_addr, uintptr(unsafe.Pointer(tp)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_settimeofday_trampoline()
+var libc_settimeofday_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_settimeofday settimeofday "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setuid(uid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setuid_trampoline), uintptr(uid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_setuid_trampoline_addr, uintptr(uid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setuid_trampoline()
+var libc_setuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setuid setuid "/usr/lib/libSystem.B.dylib"
 
@@ -2069,14 +2069,14 @@ func Symlink(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_symlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_symlink_trampoline()
+var libc_symlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_symlink symlink "/usr/lib/libSystem.B.dylib"
 
@@ -2093,28 +2093,28 @@ func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlinkat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
+	_, _, e1 := syscall_syscall(libc_symlinkat_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_symlinkat_trampoline()
+var libc_symlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_symlinkat symlinkat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Sync() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_sync_trampoline), 0, 0, 0)
+	_, _, e1 := syscall_syscall(libc_sync_trampoline_addr, 0, 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sync_trampoline()
+var libc_sync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sync sync "/usr/lib/libSystem.B.dylib"
 
@@ -2126,26 +2126,26 @@ func Truncate(path string, length int64) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_truncate_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_truncate_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_truncate_trampoline()
+var libc_truncate_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_truncate truncate "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Umask(newmask int) (oldmask int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_umask_trampoline), uintptr(newmask), 0, 0)
+	r0, _, _ := syscall_syscall(libc_umask_trampoline_addr, uintptr(newmask), 0, 0)
 	oldmask = int(r0)
 	return
 }
 
-func libc_umask_trampoline()
+var libc_umask_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_umask umask "/usr/lib/libSystem.B.dylib"
 
@@ -2157,14 +2157,14 @@ func Undelete(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_undelete_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_undelete_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_undelete_trampoline()
+var libc_undelete_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_undelete undelete "/usr/lib/libSystem.B.dylib"
 
@@ -2176,14 +2176,14 @@ func Unlink(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlink_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_unlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unlink_trampoline()
+var libc_unlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unlink unlink "/usr/lib/libSystem.B.dylib"
 
@@ -2195,14 +2195,14 @@ func Unlinkat(dirfd int, path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_unlinkat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unlinkat_trampoline()
+var libc_unlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unlinkat unlinkat "/usr/lib/libSystem.B.dylib"
 
@@ -2214,14 +2214,14 @@ func Unmount(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unmount_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_unmount_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unmount_trampoline()
+var libc_unmount_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unmount unmount "/usr/lib/libSystem.B.dylib"
 
@@ -2234,7 +2234,7 @@ func write(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall_syscall(libc_write_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2242,14 +2242,14 @@ func write(fd int, p []byte) (n int, err error) {
 	return
 }
 
-func libc_write_trampoline()
+var libc_write_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_write write "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_mmap_trampoline), uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos))
+	r0, _, e1 := syscall_syscall6(libc_mmap_trampoline_addr, uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos))
 	ret = uintptr(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2257,28 +2257,28 @@ func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (
 	return
 }
 
-func libc_mmap_trampoline()
+var libc_mmap_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mmap mmap "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func munmap(addr uintptr, length uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munmap_trampoline), uintptr(addr), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_munmap_trampoline_addr, uintptr(addr), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munmap_trampoline()
+var libc_munmap_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munmap munmap "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall_syscall(libc_read_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2289,7 +2289,7 @@ func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall_syscall(libc_write_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2300,14 +2300,14 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstat(fd int, stat *Stat_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstat64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_fstat64_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstat64_trampoline()
+var libc_fstat64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstat64 fstat64 "/usr/lib/libSystem.B.dylib"
 
@@ -2319,35 +2319,35 @@ func Fstatat(fd int, path string, stat *Stat_t, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fstatat64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fstatat64_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstatat64_trampoline()
+var libc_fstatat64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstatat64 fstatat64 "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstatfs(fd int, stat *Statfs_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstatfs64_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_fstatfs64_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstatfs64_trampoline()
+var libc_fstatfs64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstatfs64 fstatfs64 "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getfsstat64_trampoline), uintptr(buf), uintptr(size), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_getfsstat64_trampoline_addr, uintptr(buf), uintptr(size), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2355,7 +2355,7 @@ func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
 	return
 }
 
-func libc_getfsstat64_trampoline()
+var libc_getfsstat64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getfsstat64 getfsstat64 "/usr/lib/libSystem.B.dylib"
 
@@ -2367,28 +2367,28 @@ func Lstat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lstat64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_lstat64_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_lstat64_trampoline()
+var libc_lstat64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lstat64 lstat64 "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ptrace1(request int, pid int, addr uintptr, data uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_ptrace_trampoline), uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_ptrace_trampoline_addr, uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ptrace_trampoline()
+var libc_ptrace_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ptrace ptrace "/usr/lib/libSystem.B.dylib"
 
@@ -2400,14 +2400,14 @@ func Stat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_stat64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_stat64_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_stat64_trampoline()
+var libc_stat64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_stat64 stat64 "/usr/lib/libSystem.B.dylib"
 
@@ -2419,13 +2419,13 @@ func Statfs(path string, stat *Statfs_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_statfs64_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_statfs64_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_statfs64_trampoline()
+var libc_statfs64_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_statfs64 statfs64 "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
index b8f316e676d..bc169c2ab9c 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
@@ -5,287 +5,855 @@
 // +build go1.12
 
 #include "textflag.h"
-TEXT ·libc_getgroups_trampoline(SB),NOSPLIT,$0-0
+
+TEXT libc_getgroups_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getgroups(SB)
-TEXT ·libc_setgroups_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getgroups_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getgroups_trampoline_addr(SB)/8, $libc_getgroups_trampoline<>(SB)
+
+TEXT libc_setgroups_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setgroups(SB)
-TEXT ·libc_wait4_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setgroups_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setgroups_trampoline_addr(SB)/8, $libc_setgroups_trampoline<>(SB)
+
+TEXT libc_wait4_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_wait4(SB)
-TEXT ·libc_accept_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_wait4_trampoline_addr(SB), RODATA, $8
+DATA	·libc_wait4_trampoline_addr(SB)/8, $libc_wait4_trampoline<>(SB)
+
+TEXT libc_accept_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_accept(SB)
-TEXT ·libc_bind_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_accept_trampoline_addr(SB), RODATA, $8
+DATA	·libc_accept_trampoline_addr(SB)/8, $libc_accept_trampoline<>(SB)
+
+TEXT libc_bind_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_bind(SB)
-TEXT ·libc_connect_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_bind_trampoline_addr(SB), RODATA, $8
+DATA	·libc_bind_trampoline_addr(SB)/8, $libc_bind_trampoline<>(SB)
+
+TEXT libc_connect_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_connect(SB)
-TEXT ·libc_socket_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_connect_trampoline_addr(SB), RODATA, $8
+DATA	·libc_connect_trampoline_addr(SB)/8, $libc_connect_trampoline<>(SB)
+
+TEXT libc_socket_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_socket(SB)
-TEXT ·libc_getsockopt_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_socket_trampoline_addr(SB), RODATA, $8
+DATA	·libc_socket_trampoline_addr(SB)/8, $libc_socket_trampoline<>(SB)
+
+TEXT libc_getsockopt_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsockopt(SB)
-TEXT ·libc_setsockopt_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsockopt_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsockopt_trampoline_addr(SB)/8, $libc_getsockopt_trampoline<>(SB)
+
+TEXT libc_setsockopt_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setsockopt(SB)
-TEXT ·libc_getpeername_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setsockopt_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setsockopt_trampoline_addr(SB)/8, $libc_setsockopt_trampoline<>(SB)
+
+TEXT libc_getpeername_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpeername(SB)
-TEXT ·libc_getsockname_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpeername_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpeername_trampoline_addr(SB)/8, $libc_getpeername_trampoline<>(SB)
+
+TEXT libc_getsockname_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsockname(SB)
-TEXT ·libc_shutdown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsockname_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsockname_trampoline_addr(SB)/8, $libc_getsockname_trampoline<>(SB)
+
+TEXT libc_shutdown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_shutdown(SB)
-TEXT ·libc_socketpair_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_shutdown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_shutdown_trampoline_addr(SB)/8, $libc_shutdown_trampoline<>(SB)
+
+TEXT libc_socketpair_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_socketpair(SB)
-TEXT ·libc_recvfrom_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_socketpair_trampoline_addr(SB), RODATA, $8
+DATA	·libc_socketpair_trampoline_addr(SB)/8, $libc_socketpair_trampoline<>(SB)
+
+TEXT libc_recvfrom_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_recvfrom(SB)
-TEXT ·libc_sendto_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_recvfrom_trampoline_addr(SB), RODATA, $8
+DATA	·libc_recvfrom_trampoline_addr(SB)/8, $libc_recvfrom_trampoline<>(SB)
+
+TEXT libc_sendto_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendto(SB)
-TEXT ·libc_recvmsg_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendto_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendto_trampoline_addr(SB)/8, $libc_sendto_trampoline<>(SB)
+
+TEXT libc_recvmsg_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_recvmsg(SB)
-TEXT ·libc_sendmsg_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_recvmsg_trampoline_addr(SB), RODATA, $8
+DATA	·libc_recvmsg_trampoline_addr(SB)/8, $libc_recvmsg_trampoline<>(SB)
+
+TEXT libc_sendmsg_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendmsg(SB)
-TEXT ·libc_kevent_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendmsg_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendmsg_trampoline_addr(SB)/8, $libc_sendmsg_trampoline<>(SB)
+
+TEXT libc_kevent_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kevent(SB)
-TEXT ·libc_utimes_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kevent_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kevent_trampoline_addr(SB)/8, $libc_kevent_trampoline<>(SB)
+
+TEXT libc_utimes_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_utimes(SB)
-TEXT ·libc_futimes_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_utimes_trampoline_addr(SB), RODATA, $8
+DATA	·libc_utimes_trampoline_addr(SB)/8, $libc_utimes_trampoline<>(SB)
+
+TEXT libc_futimes_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_futimes(SB)
-TEXT ·libc_poll_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_futimes_trampoline_addr(SB), RODATA, $8
+DATA	·libc_futimes_trampoline_addr(SB)/8, $libc_futimes_trampoline<>(SB)
+
+TEXT libc_poll_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_poll(SB)
-TEXT ·libc_madvise_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_poll_trampoline_addr(SB), RODATA, $8
+DATA	·libc_poll_trampoline_addr(SB)/8, $libc_poll_trampoline<>(SB)
+
+TEXT libc_madvise_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_madvise(SB)
-TEXT ·libc_mlock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_madvise_trampoline_addr(SB), RODATA, $8
+DATA	·libc_madvise_trampoline_addr(SB)/8, $libc_madvise_trampoline<>(SB)
+
+TEXT libc_mlock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mlock(SB)
-TEXT ·libc_mlockall_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mlock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mlock_trampoline_addr(SB)/8, $libc_mlock_trampoline<>(SB)
+
+TEXT libc_mlockall_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mlockall(SB)
-TEXT ·libc_mprotect_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mlockall_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mlockall_trampoline_addr(SB)/8, $libc_mlockall_trampoline<>(SB)
+
+TEXT libc_mprotect_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mprotect(SB)
-TEXT ·libc_msync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mprotect_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mprotect_trampoline_addr(SB)/8, $libc_mprotect_trampoline<>(SB)
+
+TEXT libc_msync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_msync(SB)
-TEXT ·libc_munlock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_msync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_msync_trampoline_addr(SB)/8, $libc_msync_trampoline<>(SB)
+
+TEXT libc_munlock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munlock(SB)
-TEXT ·libc_munlockall_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munlock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munlock_trampoline_addr(SB)/8, $libc_munlock_trampoline<>(SB)
+
+TEXT libc_munlockall_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munlockall(SB)
-TEXT ·libc_pipe_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munlockall_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munlockall_trampoline_addr(SB)/8, $libc_munlockall_trampoline<>(SB)
+
+TEXT libc_pipe_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pipe(SB)
-TEXT ·libc_getxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pipe_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pipe_trampoline_addr(SB)/8, $libc_pipe_trampoline<>(SB)
+
+TEXT libc_getxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getxattr(SB)
-TEXT ·libc_fgetxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getxattr_trampoline_addr(SB)/8, $libc_getxattr_trampoline<>(SB)
+
+TEXT libc_fgetxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fgetxattr(SB)
-TEXT ·libc_setxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fgetxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fgetxattr_trampoline_addr(SB)/8, $libc_fgetxattr_trampoline<>(SB)
+
+TEXT libc_setxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setxattr(SB)
-TEXT ·libc_fsetxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setxattr_trampoline_addr(SB)/8, $libc_setxattr_trampoline<>(SB)
+
+TEXT libc_fsetxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fsetxattr(SB)
-TEXT ·libc_removexattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fsetxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fsetxattr_trampoline_addr(SB)/8, $libc_fsetxattr_trampoline<>(SB)
+
+TEXT libc_removexattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_removexattr(SB)
-TEXT ·libc_fremovexattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_removexattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_removexattr_trampoline_addr(SB)/8, $libc_removexattr_trampoline<>(SB)
+
+TEXT libc_fremovexattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fremovexattr(SB)
-TEXT ·libc_listxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fremovexattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fremovexattr_trampoline_addr(SB)/8, $libc_fremovexattr_trampoline<>(SB)
+
+TEXT libc_listxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_listxattr(SB)
-TEXT ·libc_flistxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_listxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_listxattr_trampoline_addr(SB)/8, $libc_listxattr_trampoline<>(SB)
+
+TEXT libc_flistxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_flistxattr(SB)
-TEXT ·libc_setattrlist_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_flistxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_flistxattr_trampoline_addr(SB)/8, $libc_flistxattr_trampoline<>(SB)
+
+TEXT libc_setattrlist_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setattrlist(SB)
-TEXT ·libc_fcntl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setattrlist_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setattrlist_trampoline_addr(SB)/8, $libc_setattrlist_trampoline<>(SB)
+
+TEXT libc_fcntl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fcntl(SB)
-TEXT ·libc_kill_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fcntl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fcntl_trampoline_addr(SB)/8, $libc_fcntl_trampoline<>(SB)
+
+TEXT libc_kill_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kill(SB)
-TEXT ·libc_ioctl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kill_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kill_trampoline_addr(SB)/8, $libc_kill_trampoline<>(SB)
+
+TEXT libc_ioctl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ioctl(SB)
-TEXT ·libc_sysctl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ioctl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ioctl_trampoline_addr(SB)/8, $libc_ioctl_trampoline<>(SB)
+
+TEXT libc_sysctl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sysctl(SB)
-TEXT ·libc_sendfile_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sysctl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sysctl_trampoline_addr(SB)/8, $libc_sysctl_trampoline<>(SB)
+
+TEXT libc_sendfile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendfile(SB)
-TEXT ·libc_access_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendfile_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendfile_trampoline_addr(SB)/8, $libc_sendfile_trampoline<>(SB)
+
+TEXT libc_access_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_access(SB)
-TEXT ·libc_adjtime_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_access_trampoline_addr(SB), RODATA, $8
+DATA	·libc_access_trampoline_addr(SB)/8, $libc_access_trampoline<>(SB)
+
+TEXT libc_adjtime_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_adjtime(SB)
-TEXT ·libc_chdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_adjtime_trampoline_addr(SB), RODATA, $8
+DATA	·libc_adjtime_trampoline_addr(SB)/8, $libc_adjtime_trampoline<>(SB)
+
+TEXT libc_chdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chdir(SB)
-TEXT ·libc_chflags_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chdir_trampoline_addr(SB)/8, $libc_chdir_trampoline<>(SB)
+
+TEXT libc_chflags_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chflags(SB)
-TEXT ·libc_chmod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chflags_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chflags_trampoline_addr(SB)/8, $libc_chflags_trampoline<>(SB)
+
+TEXT libc_chmod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chmod(SB)
-TEXT ·libc_chown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chmod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chmod_trampoline_addr(SB)/8, $libc_chmod_trampoline<>(SB)
+
+TEXT libc_chown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chown(SB)
-TEXT ·libc_chroot_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chown_trampoline_addr(SB)/8, $libc_chown_trampoline<>(SB)
+
+TEXT libc_chroot_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chroot(SB)
-TEXT ·libc_clock_gettime_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chroot_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chroot_trampoline_addr(SB)/8, $libc_chroot_trampoline<>(SB)
+
+TEXT libc_clock_gettime_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clock_gettime(SB)
-TEXT ·libc_close_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clock_gettime_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clock_gettime_trampoline_addr(SB)/8, $libc_clock_gettime_trampoline<>(SB)
+
+TEXT libc_close_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_close(SB)
-TEXT ·libc_clonefile_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_close_trampoline_addr(SB), RODATA, $8
+DATA	·libc_close_trampoline_addr(SB)/8, $libc_close_trampoline<>(SB)
+
+TEXT libc_clonefile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clonefile(SB)
-TEXT ·libc_clonefileat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clonefile_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clonefile_trampoline_addr(SB)/8, $libc_clonefile_trampoline<>(SB)
+
+TEXT libc_clonefileat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clonefileat(SB)
-TEXT ·libc_dup_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clonefileat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clonefileat_trampoline_addr(SB)/8, $libc_clonefileat_trampoline<>(SB)
+
+TEXT libc_dup_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_dup(SB)
-TEXT ·libc_dup2_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_dup_trampoline_addr(SB), RODATA, $8
+DATA	·libc_dup_trampoline_addr(SB)/8, $libc_dup_trampoline<>(SB)
+
+TEXT libc_dup2_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_dup2(SB)
-TEXT ·libc_exchangedata_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_dup2_trampoline_addr(SB), RODATA, $8
+DATA	·libc_dup2_trampoline_addr(SB)/8, $libc_dup2_trampoline<>(SB)
+
+TEXT libc_exchangedata_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_exchangedata(SB)
-TEXT ·libc_exit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_exchangedata_trampoline_addr(SB), RODATA, $8
+DATA	·libc_exchangedata_trampoline_addr(SB)/8, $libc_exchangedata_trampoline<>(SB)
+
+TEXT libc_exit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_exit(SB)
-TEXT ·libc_faccessat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_exit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_exit_trampoline_addr(SB)/8, $libc_exit_trampoline<>(SB)
+
+TEXT libc_faccessat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_faccessat(SB)
-TEXT ·libc_fchdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_faccessat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_faccessat_trampoline_addr(SB)/8, $libc_faccessat_trampoline<>(SB)
+
+TEXT libc_fchdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchdir(SB)
-TEXT ·libc_fchflags_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchdir_trampoline_addr(SB)/8, $libc_fchdir_trampoline<>(SB)
+
+TEXT libc_fchflags_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchflags(SB)
-TEXT ·libc_fchmod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchflags_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchflags_trampoline_addr(SB)/8, $libc_fchflags_trampoline<>(SB)
+
+TEXT libc_fchmod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchmod(SB)
-TEXT ·libc_fchmodat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchmod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchmod_trampoline_addr(SB)/8, $libc_fchmod_trampoline<>(SB)
+
+TEXT libc_fchmodat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchmodat(SB)
-TEXT ·libc_fchown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchmodat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchmodat_trampoline_addr(SB)/8, $libc_fchmodat_trampoline<>(SB)
+
+TEXT libc_fchown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchown(SB)
-TEXT ·libc_fchownat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchown_trampoline_addr(SB)/8, $libc_fchown_trampoline<>(SB)
+
+TEXT libc_fchownat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchownat(SB)
-TEXT ·libc_fclonefileat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchownat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchownat_trampoline_addr(SB)/8, $libc_fchownat_trampoline<>(SB)
+
+TEXT libc_fclonefileat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fclonefileat(SB)
-TEXT ·libc_flock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fclonefileat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fclonefileat_trampoline_addr(SB)/8, $libc_fclonefileat_trampoline<>(SB)
+
+TEXT libc_flock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_flock(SB)
-TEXT ·libc_fpathconf_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_flock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_flock_trampoline_addr(SB)/8, $libc_flock_trampoline<>(SB)
+
+TEXT libc_fpathconf_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fpathconf(SB)
-TEXT ·libc_fsync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fpathconf_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fpathconf_trampoline_addr(SB)/8, $libc_fpathconf_trampoline<>(SB)
+
+TEXT libc_fsync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fsync(SB)
-TEXT ·libc_ftruncate_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fsync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fsync_trampoline_addr(SB)/8, $libc_fsync_trampoline<>(SB)
+
+TEXT libc_ftruncate_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ftruncate(SB)
-TEXT ·libc_getcwd_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ftruncate_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ftruncate_trampoline_addr(SB)/8, $libc_ftruncate_trampoline<>(SB)
+
+TEXT libc_getcwd_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getcwd(SB)
-TEXT ·libc_getdtablesize_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getcwd_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getcwd_trampoline_addr(SB)/8, $libc_getcwd_trampoline<>(SB)
+
+TEXT libc_getdtablesize_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getdtablesize(SB)
-TEXT ·libc_getegid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getdtablesize_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getdtablesize_trampoline_addr(SB)/8, $libc_getdtablesize_trampoline<>(SB)
+
+TEXT libc_getegid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getegid(SB)
-TEXT ·libc_geteuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getegid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getegid_trampoline_addr(SB)/8, $libc_getegid_trampoline<>(SB)
+
+TEXT libc_geteuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_geteuid(SB)
-TEXT ·libc_getgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_geteuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_geteuid_trampoline_addr(SB)/8, $libc_geteuid_trampoline<>(SB)
+
+TEXT libc_getgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getgid(SB)
-TEXT ·libc_getpgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getgid_trampoline_addr(SB)/8, $libc_getgid_trampoline<>(SB)
+
+TEXT libc_getpgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpgid(SB)
-TEXT ·libc_getpgrp_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpgid_trampoline_addr(SB)/8, $libc_getpgid_trampoline<>(SB)
+
+TEXT libc_getpgrp_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpgrp(SB)
-TEXT ·libc_getpid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpgrp_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpgrp_trampoline_addr(SB)/8, $libc_getpgrp_trampoline<>(SB)
+
+TEXT libc_getpid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpid(SB)
-TEXT ·libc_getppid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpid_trampoline_addr(SB)/8, $libc_getpid_trampoline<>(SB)
+
+TEXT libc_getppid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getppid(SB)
-TEXT ·libc_getpriority_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getppid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getppid_trampoline_addr(SB)/8, $libc_getppid_trampoline<>(SB)
+
+TEXT libc_getpriority_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpriority(SB)
-TEXT ·libc_getrlimit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpriority_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpriority_trampoline_addr(SB)/8, $libc_getpriority_trampoline<>(SB)
+
+TEXT libc_getrlimit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getrlimit(SB)
-TEXT ·libc_getrusage_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getrlimit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getrlimit_trampoline_addr(SB)/8, $libc_getrlimit_trampoline<>(SB)
+
+TEXT libc_getrusage_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getrusage(SB)
-TEXT ·libc_getsid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getrusage_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getrusage_trampoline_addr(SB)/8, $libc_getrusage_trampoline<>(SB)
+
+TEXT libc_getsid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsid(SB)
-TEXT ·libc_gettimeofday_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsid_trampoline_addr(SB)/8, $libc_getsid_trampoline<>(SB)
+
+TEXT libc_gettimeofday_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_gettimeofday(SB)
-TEXT ·libc_getuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_gettimeofday_trampoline_addr(SB), RODATA, $8
+DATA	·libc_gettimeofday_trampoline_addr(SB)/8, $libc_gettimeofday_trampoline<>(SB)
+
+TEXT libc_getuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getuid(SB)
-TEXT ·libc_issetugid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getuid_trampoline_addr(SB)/8, $libc_getuid_trampoline<>(SB)
+
+TEXT libc_issetugid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_issetugid(SB)
-TEXT ·libc_kqueue_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_issetugid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_issetugid_trampoline_addr(SB)/8, $libc_issetugid_trampoline<>(SB)
+
+TEXT libc_kqueue_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kqueue(SB)
-TEXT ·libc_lchown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kqueue_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kqueue_trampoline_addr(SB)/8, $libc_kqueue_trampoline<>(SB)
+
+TEXT libc_lchown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lchown(SB)
-TEXT ·libc_link_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lchown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lchown_trampoline_addr(SB)/8, $libc_lchown_trampoline<>(SB)
+
+TEXT libc_link_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_link(SB)
-TEXT ·libc_linkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_link_trampoline_addr(SB), RODATA, $8
+DATA	·libc_link_trampoline_addr(SB)/8, $libc_link_trampoline<>(SB)
+
+TEXT libc_linkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_linkat(SB)
-TEXT ·libc_listen_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_linkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_linkat_trampoline_addr(SB)/8, $libc_linkat_trampoline<>(SB)
+
+TEXT libc_listen_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_listen(SB)
-TEXT ·libc_mkdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_listen_trampoline_addr(SB), RODATA, $8
+DATA	·libc_listen_trampoline_addr(SB)/8, $libc_listen_trampoline<>(SB)
+
+TEXT libc_mkdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkdir(SB)
-TEXT ·libc_mkdirat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkdir_trampoline_addr(SB)/8, $libc_mkdir_trampoline<>(SB)
+
+TEXT libc_mkdirat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkdirat(SB)
-TEXT ·libc_mkfifo_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkdirat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkdirat_trampoline_addr(SB)/8, $libc_mkdirat_trampoline<>(SB)
+
+TEXT libc_mkfifo_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkfifo(SB)
-TEXT ·libc_mknod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkfifo_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkfifo_trampoline_addr(SB)/8, $libc_mkfifo_trampoline<>(SB)
+
+TEXT libc_mknod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mknod(SB)
-TEXT ·libc_open_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mknod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mknod_trampoline_addr(SB)/8, $libc_mknod_trampoline<>(SB)
+
+TEXT libc_open_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_open(SB)
-TEXT ·libc_openat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_open_trampoline_addr(SB), RODATA, $8
+DATA	·libc_open_trampoline_addr(SB)/8, $libc_open_trampoline<>(SB)
+
+TEXT libc_openat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_openat(SB)
-TEXT ·libc_pathconf_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_openat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_openat_trampoline_addr(SB)/8, $libc_openat_trampoline<>(SB)
+
+TEXT libc_pathconf_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pathconf(SB)
-TEXT ·libc_pread_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pathconf_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pathconf_trampoline_addr(SB)/8, $libc_pathconf_trampoline<>(SB)
+
+TEXT libc_pread_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pread(SB)
-TEXT ·libc_pwrite_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pread_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pread_trampoline_addr(SB)/8, $libc_pread_trampoline<>(SB)
+
+TEXT libc_pwrite_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pwrite(SB)
-TEXT ·libc_read_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pwrite_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pwrite_trampoline_addr(SB)/8, $libc_pwrite_trampoline<>(SB)
+
+TEXT libc_read_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_read(SB)
-TEXT ·libc_readlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_read_trampoline_addr(SB), RODATA, $8
+DATA	·libc_read_trampoline_addr(SB)/8, $libc_read_trampoline<>(SB)
+
+TEXT libc_readlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readlink(SB)
-TEXT ·libc_readlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_readlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readlink_trampoline_addr(SB)/8, $libc_readlink_trampoline<>(SB)
+
+TEXT libc_readlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readlinkat(SB)
-TEXT ·libc_rename_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_readlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readlinkat_trampoline_addr(SB)/8, $libc_readlinkat_trampoline<>(SB)
+
+TEXT libc_rename_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_rename(SB)
-TEXT ·libc_renameat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_rename_trampoline_addr(SB), RODATA, $8
+DATA	·libc_rename_trampoline_addr(SB)/8, $libc_rename_trampoline<>(SB)
+
+TEXT libc_renameat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_renameat(SB)
-TEXT ·libc_revoke_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_renameat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_renameat_trampoline_addr(SB)/8, $libc_renameat_trampoline<>(SB)
+
+TEXT libc_revoke_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_revoke(SB)
-TEXT ·libc_rmdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_revoke_trampoline_addr(SB), RODATA, $8
+DATA	·libc_revoke_trampoline_addr(SB)/8, $libc_revoke_trampoline<>(SB)
+
+TEXT libc_rmdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_rmdir(SB)
-TEXT ·libc_lseek_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_rmdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_rmdir_trampoline_addr(SB)/8, $libc_rmdir_trampoline<>(SB)
+
+TEXT libc_lseek_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lseek(SB)
-TEXT ·libc_select_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lseek_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lseek_trampoline_addr(SB)/8, $libc_lseek_trampoline<>(SB)
+
+TEXT libc_select_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_select(SB)
-TEXT ·libc_setegid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_select_trampoline_addr(SB), RODATA, $8
+DATA	·libc_select_trampoline_addr(SB)/8, $libc_select_trampoline<>(SB)
+
+TEXT libc_setegid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setegid(SB)
-TEXT ·libc_seteuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setegid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setegid_trampoline_addr(SB)/8, $libc_setegid_trampoline<>(SB)
+
+TEXT libc_seteuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_seteuid(SB)
-TEXT ·libc_setgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_seteuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_seteuid_trampoline_addr(SB)/8, $libc_seteuid_trampoline<>(SB)
+
+TEXT libc_setgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setgid(SB)
-TEXT ·libc_setlogin_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setgid_trampoline_addr(SB)/8, $libc_setgid_trampoline<>(SB)
+
+TEXT libc_setlogin_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setlogin(SB)
-TEXT ·libc_setpgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setlogin_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setlogin_trampoline_addr(SB)/8, $libc_setlogin_trampoline<>(SB)
+
+TEXT libc_setpgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setpgid(SB)
-TEXT ·libc_setpriority_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setpgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setpgid_trampoline_addr(SB)/8, $libc_setpgid_trampoline<>(SB)
+
+TEXT libc_setpriority_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setpriority(SB)
-TEXT ·libc_setprivexec_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setpriority_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setpriority_trampoline_addr(SB)/8, $libc_setpriority_trampoline<>(SB)
+
+TEXT libc_setprivexec_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setprivexec(SB)
-TEXT ·libc_setregid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setprivexec_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setprivexec_trampoline_addr(SB)/8, $libc_setprivexec_trampoline<>(SB)
+
+TEXT libc_setregid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setregid(SB)
-TEXT ·libc_setreuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setregid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setregid_trampoline_addr(SB)/8, $libc_setregid_trampoline<>(SB)
+
+TEXT libc_setreuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setreuid(SB)
-TEXT ·libc_setrlimit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setreuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setreuid_trampoline_addr(SB)/8, $libc_setreuid_trampoline<>(SB)
+
+TEXT libc_setrlimit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setrlimit(SB)
-TEXT ·libc_setsid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setrlimit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setrlimit_trampoline_addr(SB)/8, $libc_setrlimit_trampoline<>(SB)
+
+TEXT libc_setsid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setsid(SB)
-TEXT ·libc_settimeofday_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setsid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setsid_trampoline_addr(SB)/8, $libc_setsid_trampoline<>(SB)
+
+TEXT libc_settimeofday_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_settimeofday(SB)
-TEXT ·libc_setuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_settimeofday_trampoline_addr(SB), RODATA, $8
+DATA	·libc_settimeofday_trampoline_addr(SB)/8, $libc_settimeofday_trampoline<>(SB)
+
+TEXT libc_setuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setuid(SB)
-TEXT ·libc_symlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setuid_trampoline_addr(SB)/8, $libc_setuid_trampoline<>(SB)
+
+TEXT libc_symlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_symlink(SB)
-TEXT ·libc_symlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_symlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_symlink_trampoline_addr(SB)/8, $libc_symlink_trampoline<>(SB)
+
+TEXT libc_symlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_symlinkat(SB)
-TEXT ·libc_sync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_symlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_symlinkat_trampoline_addr(SB)/8, $libc_symlinkat_trampoline<>(SB)
+
+TEXT libc_sync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sync(SB)
-TEXT ·libc_truncate_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sync_trampoline_addr(SB)/8, $libc_sync_trampoline<>(SB)
+
+TEXT libc_truncate_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_truncate(SB)
-TEXT ·libc_umask_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_truncate_trampoline_addr(SB), RODATA, $8
+DATA	·libc_truncate_trampoline_addr(SB)/8, $libc_truncate_trampoline<>(SB)
+
+TEXT libc_umask_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_umask(SB)
-TEXT ·libc_undelete_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_umask_trampoline_addr(SB), RODATA, $8
+DATA	·libc_umask_trampoline_addr(SB)/8, $libc_umask_trampoline<>(SB)
+
+TEXT libc_undelete_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_undelete(SB)
-TEXT ·libc_unlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_undelete_trampoline_addr(SB), RODATA, $8
+DATA	·libc_undelete_trampoline_addr(SB)/8, $libc_undelete_trampoline<>(SB)
+
+TEXT libc_unlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unlink(SB)
-TEXT ·libc_unlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unlink_trampoline_addr(SB)/8, $libc_unlink_trampoline<>(SB)
+
+TEXT libc_unlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unlinkat(SB)
-TEXT ·libc_unmount_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unlinkat_trampoline_addr(SB)/8, $libc_unlinkat_trampoline<>(SB)
+
+TEXT libc_unmount_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unmount(SB)
-TEXT ·libc_write_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unmount_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unmount_trampoline_addr(SB)/8, $libc_unmount_trampoline<>(SB)
+
+TEXT libc_write_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_write(SB)
-TEXT ·libc_mmap_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_write_trampoline_addr(SB), RODATA, $8
+DATA	·libc_write_trampoline_addr(SB)/8, $libc_write_trampoline<>(SB)
+
+TEXT libc_mmap_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mmap(SB)
-TEXT ·libc_munmap_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mmap_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mmap_trampoline_addr(SB)/8, $libc_mmap_trampoline<>(SB)
+
+TEXT libc_munmap_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munmap(SB)
-TEXT ·libc_fstat64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munmap_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munmap_trampoline_addr(SB)/8, $libc_munmap_trampoline<>(SB)
+
+TEXT libc_fstat64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstat64(SB)
-TEXT ·libc_fstatat64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstat64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstat64_trampoline_addr(SB)/8, $libc_fstat64_trampoline<>(SB)
+
+TEXT libc_fstatat64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstatat64(SB)
-TEXT ·libc_fstatfs64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstatat64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstatat64_trampoline_addr(SB)/8, $libc_fstatat64_trampoline<>(SB)
+
+TEXT libc_fstatfs64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstatfs64(SB)
-TEXT ·libc_getfsstat64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstatfs64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstatfs64_trampoline_addr(SB)/8, $libc_fstatfs64_trampoline<>(SB)
+
+TEXT libc_getfsstat64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getfsstat64(SB)
-TEXT ·libc_lstat64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getfsstat64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getfsstat64_trampoline_addr(SB)/8, $libc_getfsstat64_trampoline<>(SB)
+
+TEXT libc_lstat64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lstat64(SB)
-TEXT ·libc_ptrace_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lstat64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lstat64_trampoline_addr(SB)/8, $libc_lstat64_trampoline<>(SB)
+
+TEXT libc_ptrace_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ptrace(SB)
-TEXT ·libc_stat64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ptrace_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ptrace_trampoline_addr(SB)/8, $libc_ptrace_trampoline<>(SB)
+
+TEXT libc_stat64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_stat64(SB)
-TEXT ·libc_statfs64_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_stat64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_stat64_trampoline_addr(SB)/8, $libc_stat64_trampoline<>(SB)
+
+TEXT libc_statfs64_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_statfs64(SB)
+
+GLOBL	·libc_statfs64_trampoline_addr(SB), RODATA, $8
+DATA	·libc_statfs64_trampoline_addr(SB)/8, $libc_statfs64_trampoline<>(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.go
deleted file mode 100644
index ed437f89a9e..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// go run mksyscall.go -l32 -tags darwin,arm,go1.13 syscall_darwin.1_13.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build darwin && arm && go1.13
-// +build darwin,arm,go1.13
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-var _ syscall.Errno
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func closedir(dir uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_closedir_trampoline), uintptr(dir), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_closedir_trampoline()
-
-//go:cgo_import_dynamic libc_closedir closedir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno) {
-	r0, _, _ := syscall_syscall(funcPC(libc_readdir_r_trampoline), uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
-	res = Errno(r0)
-	return
-}
-
-func libc_readdir_r_trampoline()
-
-//go:cgo_import_dynamic libc_readdir_r readdir_r "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.s
deleted file mode 100644
index 0cc80ad87ea..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.1_13.s
+++ /dev/null
@@ -1,13 +0,0 @@
-// go run mkasm_darwin.go arm
-// Code generated by the command above; DO NOT EDIT.
-
-//go:build go1.13
-// +build go1.13
-
-#include "textflag.h"
-TEXT ·libc_fdopendir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fdopendir(SB)
-TEXT ·libc_closedir_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_closedir(SB)
-TEXT ·libc_readdir_r_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_readdir_r(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.go
deleted file mode 100644
index 7f88cb5ea22..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.go
+++ /dev/null
@@ -1,2417 +0,0 @@
-// go run mksyscall.go -l32 -tags darwin,arm,go1.12 syscall_bsd.go syscall_darwin.go syscall_darwin_arm.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build darwin && arm && go1.12
-// +build darwin,arm,go1.12
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-var _ syscall.Errno
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getgroups_trampoline()
-
-//go:cgo_import_dynamic libc_getgroups getgroups "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setgroups(ngid int, gid *_Gid_t) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setgroups_trampoline()
-
-//go:cgo_import_dynamic libc_setgroups setgroups "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_wait4_trampoline), uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
-	wpid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_wait4_trampoline()
-
-//go:cgo_import_dynamic libc_wait4 wait4 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_accept_trampoline), uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_accept_trampoline()
-
-//go:cgo_import_dynamic libc_accept accept "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_bind_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_bind_trampoline()
-
-//go:cgo_import_dynamic libc_bind bind "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_connect_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_connect_trampoline()
-
-//go:cgo_import_dynamic libc_connect connect "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func socket(domain int, typ int, proto int) (fd int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_socket_trampoline), uintptr(domain), uintptr(typ), uintptr(proto))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_socket_trampoline()
-
-//go:cgo_import_dynamic libc_socket socket "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_getsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsockopt_trampoline()
-
-//go:cgo_import_dynamic libc_getsockopt getsockopt "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setsockopt_trampoline()
-
-//go:cgo_import_dynamic libc_setsockopt setsockopt "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getpeername_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpeername_trampoline()
-
-//go:cgo_import_dynamic libc_getpeername getpeername "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getsockname_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsockname_trampoline()
-
-//go:cgo_import_dynamic libc_getsockname getsockname "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Shutdown(s int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_shutdown_trampoline), uintptr(s), uintptr(how), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_shutdown_trampoline()
-
-//go:cgo_import_dynamic libc_shutdown shutdown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func socketpair(domain int, typ int, proto int, fd *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall6(funcPC(libc_socketpair_trampoline), uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_socketpair_trampoline()
-
-//go:cgo_import_dynamic libc_socketpair socketpair "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_recvfrom_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_recvfrom_trampoline()
-
-//go:cgo_import_dynamic libc_recvfrom recvfrom "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendto_trampoline), uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendto_trampoline()
-
-//go:cgo_import_dynamic libc_sendto sendto "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_recvmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_recvmsg_trampoline()
-
-//go:cgo_import_dynamic libc_recvmsg recvmsg "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_sendmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendmsg_trampoline()
-
-//go:cgo_import_dynamic libc_sendmsg sendmsg "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_kevent_trampoline), uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kevent_trampoline()
-
-//go:cgo_import_dynamic libc_kevent kevent "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func utimes(path string, timeval *[2]Timeval) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_utimes_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_utimes_trampoline()
-
-//go:cgo_import_dynamic libc_utimes utimes "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func futimes(fd int, timeval *[2]Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_futimes_trampoline), uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_futimes_trampoline()
-
-//go:cgo_import_dynamic libc_futimes futimes "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_poll_trampoline), uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_poll_trampoline()
-
-//go:cgo_import_dynamic libc_poll poll "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Madvise(b []byte, behav int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_madvise_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(behav))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_madvise_trampoline()
-
-//go:cgo_import_dynamic libc_madvise madvise "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mlock_trampoline()
-
-//go:cgo_import_dynamic libc_mlock mlock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mlockall(flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_mlockall_trampoline), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mlockall_trampoline()
-
-//go:cgo_import_dynamic libc_mlockall mlockall "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mprotect(b []byte, prot int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mprotect_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(prot))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mprotect_trampoline()
-
-//go:cgo_import_dynamic libc_mprotect mprotect "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Msync(b []byte, flags int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_msync_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_msync_trampoline()
-
-//go:cgo_import_dynamic libc_msync msync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_munlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munlock_trampoline()
-
-//go:cgo_import_dynamic libc_munlock munlock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlockall() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munlockall_trampoline), 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munlockall_trampoline()
-
-//go:cgo_import_dynamic libc_munlockall munlockall "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func pipe(p *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_pipe_trampoline), uintptr(unsafe.Pointer(p)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pipe_trampoline()
-
-//go:cgo_import_dynamic libc_pipe pipe "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getxattr(path string, attr string, dest *byte, size int, position uint32, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_getxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getxattr_trampoline()
-
-//go:cgo_import_dynamic libc_getxattr getxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_fgetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fgetxattr_trampoline()
-
-//go:cgo_import_dynamic libc_fgetxattr fgetxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setxattr(path string, attr string, data *byte, size int, position uint32, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_setxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setxattr_trampoline()
-
-//go:cgo_import_dynamic libc_setxattr setxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fsetxattr(fd int, attr string, data *byte, size int, position uint32, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fsetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fsetxattr_trampoline()
-
-//go:cgo_import_dynamic libc_fsetxattr fsetxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func removexattr(path string, attr string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_removexattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_removexattr_trampoline()
-
-//go:cgo_import_dynamic libc_removexattr removexattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fremovexattr(fd int, attr string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(attr)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_fremovexattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fremovexattr_trampoline()
-
-//go:cgo_import_dynamic libc_fremovexattr fremovexattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func listxattr(path string, dest *byte, size int, options int) (sz int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_listxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_listxattr_trampoline()
-
-//go:cgo_import_dynamic libc_listxattr listxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_flistxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
-	sz = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_flistxattr_trampoline()
-
-//go:cgo_import_dynamic libc_flistxattr flistxattr "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func setattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setattrlist_trampoline), uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setattrlist_trampoline()
-
-//go:cgo_import_dynamic libc_setattrlist setattrlist "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func fcntl(fd int, cmd int, arg int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fcntl_trampoline()
-
-//go:cgo_import_dynamic libc_fcntl fcntl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func kill(pid int, signum int, posix int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_kill_trampoline), uintptr(pid), uintptr(signum), uintptr(posix))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kill_trampoline()
-
-//go:cgo_import_dynamic libc_kill kill "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func ioctl(fd int, req uint, arg uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ioctl_trampoline), uintptr(fd), uintptr(req), uintptr(arg))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_ioctl_trampoline()
-
-//go:cgo_import_dynamic libc_ioctl ioctl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) {
-	var _p0 unsafe.Pointer
-	if len(mib) > 0 {
-		_p0 = unsafe.Pointer(&mib[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sysctl_trampoline), uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sysctl_trampoline()
-
-//go:cgo_import_dynamic libc_sysctl sysctl "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
-	_, _, e1 := syscall_syscall9(funcPC(libc_sendfile_trampoline), uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(offset>>32), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sendfile_trampoline()
-
-//go:cgo_import_dynamic libc_sendfile sendfile "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Access(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_access_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_access_trampoline()
-
-//go:cgo_import_dynamic libc_access access "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Adjtime(delta *Timeval, olddelta *Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_adjtime_trampoline), uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_adjtime_trampoline()
-
-//go:cgo_import_dynamic libc_adjtime adjtime "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chdir(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chdir_trampoline()
-
-//go:cgo_import_dynamic libc_chdir chdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chflags(path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chflags_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chflags_trampoline()
-
-//go:cgo_import_dynamic libc_chflags chflags "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chmod(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chmod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chmod_trampoline()
-
-//go:cgo_import_dynamic libc_chmod chmod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chown(path string, uid int, gid int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chown_trampoline()
-
-//go:cgo_import_dynamic libc_chown chown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Chroot(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chroot_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_chroot_trampoline()
-
-//go:cgo_import_dynamic libc_chroot chroot "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func ClockGettime(clockid int32, time *Timespec) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_clock_gettime_trampoline), uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clock_gettime_trampoline()
-
-//go:cgo_import_dynamic libc_clock_gettime clock_gettime "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Close(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_close_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_close_trampoline()
-
-//go:cgo_import_dynamic libc_close close "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Clonefile(src string, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(src)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_clonefile_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clonefile_trampoline()
-
-//go:cgo_import_dynamic libc_clonefile clonefile "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Clonefileat(srcDirfd int, src string, dstDirfd int, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(src)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_clonefileat_trampoline), uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_clonefileat_trampoline()
-
-//go:cgo_import_dynamic libc_clonefileat clonefileat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_dup_trampoline), uintptr(fd), 0, 0)
-	nfd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_dup_trampoline()
-
-//go:cgo_import_dynamic libc_dup dup "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Dup2(from int, to int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_dup2_trampoline), uintptr(from), uintptr(to), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_dup2_trampoline()
-
-//go:cgo_import_dynamic libc_dup2 dup2 "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Exchangedata(path1 string, path2 string, options int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path1)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(path2)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_exchangedata_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_exchangedata_trampoline()
-
-//go:cgo_import_dynamic libc_exchangedata exchangedata "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Exit(code int) {
-	syscall_syscall(funcPC(libc_exit_trampoline), uintptr(code), 0, 0)
-	return
-}
-
-func libc_exit_trampoline()
-
-//go:cgo_import_dynamic libc_exit exit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_faccessat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_faccessat_trampoline()
-
-//go:cgo_import_dynamic libc_faccessat faccessat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchdir(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchdir_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchdir_trampoline()
-
-//go:cgo_import_dynamic libc_fchdir fchdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchflags(fd int, flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchflags_trampoline), uintptr(fd), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchflags_trampoline()
-
-//go:cgo_import_dynamic libc_fchflags fchflags "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchmod(fd int, mode uint32) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchmod_trampoline), uintptr(fd), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchmod_trampoline()
-
-//go:cgo_import_dynamic libc_fchmod fchmod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchmodat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchmodat_trampoline()
-
-//go:cgo_import_dynamic libc_fchmodat fchmodat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchown(fd int, uid int, gid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchown_trampoline), uintptr(fd), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchown_trampoline()
-
-//go:cgo_import_dynamic libc_fchown fchown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchownat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fchownat_trampoline()
-
-//go:cgo_import_dynamic libc_fchownat fchownat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fclonefileat(srcDirfd int, dstDirfd int, dst string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(dst)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fclonefileat_trampoline), uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fclonefileat_trampoline()
-
-//go:cgo_import_dynamic libc_fclonefileat fclonefileat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Flock(fd int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_flock_trampoline), uintptr(fd), uintptr(how), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_flock_trampoline()
-
-//go:cgo_import_dynamic libc_flock flock "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fpathconf(fd int, name int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fpathconf_trampoline), uintptr(fd), uintptr(name), 0)
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fpathconf_trampoline()
-
-//go:cgo_import_dynamic libc_fpathconf fpathconf "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fsync(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fsync_trampoline), uintptr(fd), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fsync_trampoline()
-
-//go:cgo_import_dynamic libc_fsync fsync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Ftruncate(fd int, length int64) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ftruncate_trampoline), uintptr(fd), uintptr(length), uintptr(length>>32))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_ftruncate_trampoline()
-
-//go:cgo_import_dynamic libc_ftruncate ftruncate "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getcwd(buf []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_getcwd_trampoline), uintptr(_p0), uintptr(len(buf)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getcwd_trampoline()
-
-//go:cgo_import_dynamic libc_getcwd getcwd "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getdtablesize() (size int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_getdtablesize_trampoline), 0, 0, 0)
-	size = int(r0)
-	return
-}
-
-func libc_getdtablesize_trampoline()
-
-//go:cgo_import_dynamic libc_getdtablesize getdtablesize "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getegid() (egid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getegid_trampoline), 0, 0, 0)
-	egid = int(r0)
-	return
-}
-
-func libc_getegid_trampoline()
-
-//go:cgo_import_dynamic libc_getegid getegid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Geteuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_geteuid_trampoline), 0, 0, 0)
-	uid = int(r0)
-	return
-}
-
-func libc_geteuid_trampoline()
-
-//go:cgo_import_dynamic libc_geteuid geteuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getgid() (gid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getgid_trampoline), 0, 0, 0)
-	gid = int(r0)
-	return
-}
-
-func libc_getgid_trampoline()
-
-//go:cgo_import_dynamic libc_getgid getgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpgid(pid int) (pgid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getpgid_trampoline), uintptr(pid), 0, 0)
-	pgid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpgid_trampoline()
-
-//go:cgo_import_dynamic libc_getpgid getpgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpgrp() (pgrp int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpgrp_trampoline), 0, 0, 0)
-	pgrp = int(r0)
-	return
-}
-
-func libc_getpgrp_trampoline()
-
-//go:cgo_import_dynamic libc_getpgrp getpgrp "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpid() (pid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpid_trampoline), 0, 0, 0)
-	pid = int(r0)
-	return
-}
-
-func libc_getpid_trampoline()
-
-//go:cgo_import_dynamic libc_getpid getpid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getppid() (ppid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getppid_trampoline), 0, 0, 0)
-	ppid = int(r0)
-	return
-}
-
-func libc_getppid_trampoline()
-
-//go:cgo_import_dynamic libc_getppid getppid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getpriority(which int, who int) (prio int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getpriority_trampoline), uintptr(which), uintptr(who), 0)
-	prio = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getpriority_trampoline()
-
-//go:cgo_import_dynamic libc_getpriority getpriority "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getrlimit_trampoline()
-
-//go:cgo_import_dynamic libc_getrlimit getrlimit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getrusage(who int, rusage *Rusage) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrusage_trampoline), uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getrusage_trampoline()
-
-//go:cgo_import_dynamic libc_getrusage getrusage "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getsid(pid int) (sid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getsid_trampoline), uintptr(pid), 0, 0)
-	sid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getsid_trampoline()
-
-//go:cgo_import_dynamic libc_getsid getsid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Gettimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_gettimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_gettimeofday_trampoline()
-
-//go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Getuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getuid_trampoline), 0, 0, 0)
-	uid = int(r0)
-	return
-}
-
-func libc_getuid_trampoline()
-
-//go:cgo_import_dynamic libc_getuid getuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Issetugid() (tainted bool) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_issetugid_trampoline), 0, 0, 0)
-	tainted = bool(r0 != 0)
-	return
-}
-
-func libc_issetugid_trampoline()
-
-//go:cgo_import_dynamic libc_issetugid issetugid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Kqueue() (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_kqueue_trampoline), 0, 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_kqueue_trampoline()
-
-//go:cgo_import_dynamic libc_kqueue kqueue "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Lchown(path string, uid int, gid int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lchown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lchown_trampoline()
-
-//go:cgo_import_dynamic libc_lchown lchown "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Link(path string, link string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_link_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_link_trampoline()
-
-//go:cgo_import_dynamic libc_link link "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Linkat(pathfd int, path string, linkfd int, link string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_linkat_trampoline), uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_linkat_trampoline()
-
-//go:cgo_import_dynamic libc_linkat linkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Listen(s int, backlog int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_listen_trampoline), uintptr(s), uintptr(backlog), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_listen_trampoline()
-
-//go:cgo_import_dynamic libc_listen listen "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkdir(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkdir_trampoline()
-
-//go:cgo_import_dynamic libc_mkdir mkdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkdirat(dirfd int, path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdirat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkdirat_trampoline()
-
-//go:cgo_import_dynamic libc_mkdirat mkdirat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mkfifo(path string, mode uint32) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkfifo_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mkfifo_trampoline()
-
-//go:cgo_import_dynamic libc_mkfifo mkfifo "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mknod(path string, mode uint32, dev int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mknod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mknod_trampoline()
-
-//go:cgo_import_dynamic libc_mknod mknod "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Open(path string, mode int, perm uint32) (fd int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_open_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_open_trampoline()
-
-//go:cgo_import_dynamic libc_open open "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_openat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_openat_trampoline()
-
-//go:cgo_import_dynamic libc_openat openat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pathconf(path string, name int) (val int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_pathconf_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
-	val = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pathconf_trampoline()
-
-//go:cgo_import_dynamic libc_pathconf pathconf "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pread(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pread_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pread_trampoline()
-
-//go:cgo_import_dynamic libc_pread pread "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pwrite_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_pwrite_trampoline()
-
-//go:cgo_import_dynamic libc_pwrite pwrite "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func read(fd int, p []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_read_trampoline()
-
-//go:cgo_import_dynamic libc_read read "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Readlink(path string, buf []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(buf) > 0 {
-		_p1 = unsafe.Pointer(&buf[0])
-	} else {
-		_p1 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_readlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_readlink_trampoline()
-
-//go:cgo_import_dynamic libc_readlink readlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(buf) > 0 {
-		_p1 = unsafe.Pointer(&buf[0])
-	} else {
-		_p1 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_readlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_readlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_readlinkat readlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Rename(from string, to string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(from)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(to)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rename_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_rename_trampoline()
-
-//go:cgo_import_dynamic libc_rename rename "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Renameat(fromfd int, from string, tofd int, to string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(from)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(to)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_renameat_trampoline), uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_renameat_trampoline()
-
-//go:cgo_import_dynamic libc_renameat renameat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Revoke(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_revoke_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_revoke_trampoline()
-
-//go:cgo_import_dynamic libc_revoke revoke "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Rmdir(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rmdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_rmdir_trampoline()
-
-//go:cgo_import_dynamic libc_rmdir rmdir "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
-	r0, r1, e1 := syscall_syscall6(funcPC(libc_lseek_trampoline), uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(whence), 0, 0)
-	newoffset = int64(int64(r1)<<32 | int64(r0))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lseek_trampoline()
-
-//go:cgo_import_dynamic libc_lseek lseek "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_select_trampoline), uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_select_trampoline()
-
-//go:cgo_import_dynamic libc_select select "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setegid(egid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setegid_trampoline), uintptr(egid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setegid_trampoline()
-
-//go:cgo_import_dynamic libc_setegid setegid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Seteuid(euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_seteuid_trampoline), uintptr(euid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_seteuid_trampoline()
-
-//go:cgo_import_dynamic libc_seteuid seteuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setgid(gid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgid_trampoline), uintptr(gid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setgid_trampoline()
-
-//go:cgo_import_dynamic libc_setgid setgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setlogin(name string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(name)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_setlogin_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setlogin_trampoline()
-
-//go:cgo_import_dynamic libc_setlogin setlogin "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setpgid(pid int, pgid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setpgid_trampoline), uintptr(pid), uintptr(pgid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setpgid_trampoline()
-
-//go:cgo_import_dynamic libc_setpgid setpgid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setpriority(which int, who int, prio int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setpriority_trampoline), uintptr(which), uintptr(who), uintptr(prio))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setpriority_trampoline()
-
-//go:cgo_import_dynamic libc_setpriority setpriority "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setprivexec(flag int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setprivexec_trampoline), uintptr(flag), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setprivexec_trampoline()
-
-//go:cgo_import_dynamic libc_setprivexec setprivexec "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setregid_trampoline), uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setregid_trampoline()
-
-//go:cgo_import_dynamic libc_setregid setregid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setreuid_trampoline), uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setreuid_trampoline()
-
-//go:cgo_import_dynamic libc_setreuid setreuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setrlimit_trampoline()
-
-//go:cgo_import_dynamic libc_setrlimit setrlimit "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setsid() (pid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_setsid_trampoline), 0, 0, 0)
-	pid = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setsid_trampoline()
-
-//go:cgo_import_dynamic libc_setsid setsid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Settimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_settimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_settimeofday_trampoline()
-
-//go:cgo_import_dynamic libc_settimeofday settimeofday "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setuid(uid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setuid_trampoline), uintptr(uid), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_setuid_trampoline()
-
-//go:cgo_import_dynamic libc_setuid setuid "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Symlink(path string, link string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(link)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_symlink_trampoline()
-
-//go:cgo_import_dynamic libc_symlink symlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(oldpath)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(newpath)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlinkat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_symlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_symlinkat symlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Sync() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_sync_trampoline), 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_sync_trampoline()
-
-//go:cgo_import_dynamic libc_sync sync "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Truncate(path string, length int64) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_truncate_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(length), uintptr(length>>32))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_truncate_trampoline()
-
-//go:cgo_import_dynamic libc_truncate truncate "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Umask(newmask int) (oldmask int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_umask_trampoline), uintptr(newmask), 0, 0)
-	oldmask = int(r0)
-	return
-}
-
-func libc_umask_trampoline()
-
-//go:cgo_import_dynamic libc_umask umask "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Undelete(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_undelete_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_undelete_trampoline()
-
-//go:cgo_import_dynamic libc_undelete undelete "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unlink(path string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlink_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unlink_trampoline()
-
-//go:cgo_import_dynamic libc_unlink unlink "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unlinkat(dirfd int, path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unlinkat_trampoline()
-
-//go:cgo_import_dynamic libc_unlinkat unlinkat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Unmount(path string, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unmount_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_unmount_trampoline()
-
-//go:cgo_import_dynamic libc_unmount unmount "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func write(fd int, p []byte) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_write_trampoline()
-
-//go:cgo_import_dynamic libc_write write "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error) {
-	r0, _, e1 := syscall_syscall9(funcPC(libc_mmap_trampoline), uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos), uintptr(pos>>32), 0, 0)
-	ret = uintptr(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_mmap_trampoline()
-
-//go:cgo_import_dynamic libc_mmap mmap "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func munmap(addr uintptr, length uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munmap_trampoline), uintptr(addr), uintptr(length), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_munmap_trampoline()
-
-//go:cgo_import_dynamic libc_munmap munmap "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstat(fd int, stat *Stat_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstat_trampoline()
-
-//go:cgo_import_dynamic libc_fstat fstat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstatat(fd int, path string, stat *Stat_t, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fstatat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstatat_trampoline()
-
-//go:cgo_import_dynamic libc_fstatat fstatat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Fstatfs(fd int, stat *Statfs_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstatfs_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_fstatfs_trampoline()
-
-//go:cgo_import_dynamic libc_fstatfs fstatfs "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getfsstat_trampoline), uintptr(buf), uintptr(size), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_getfsstat_trampoline()
-
-//go:cgo_import_dynamic libc_getfsstat getfsstat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Lstat(path string, stat *Stat_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lstat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_lstat_trampoline()
-
-//go:cgo_import_dynamic libc_lstat lstat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Stat(path string, stat *Stat_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_stat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_stat_trampoline()
-
-//go:cgo_import_dynamic libc_stat stat "/usr/lib/libSystem.B.dylib"
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Statfs(path string, stat *Statfs_t) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := syscall_syscall(funcPC(libc_statfs_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-func libc_statfs_trampoline()
-
-//go:cgo_import_dynamic libc_statfs statfs "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.go
index d30ec4e29a0..cec595d553a 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.go
@@ -16,25 +16,25 @@ var _ syscall.Errno
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func closedir(dir uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_closedir_trampoline), uintptr(dir), 0, 0)
+	_, _, e1 := syscall_syscall(libc_closedir_trampoline_addr, uintptr(dir), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_closedir_trampoline()
+var libc_closedir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_closedir closedir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno) {
-	r0, _, _ := syscall_syscall(funcPC(libc_readdir_r_trampoline), uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
+	r0, _, _ := syscall_syscall(libc_readdir_r_trampoline_addr, uintptr(dir), uintptr(unsafe.Pointer(entry)), uintptr(unsafe.Pointer(result)))
 	res = Errno(r0)
 	return
 }
 
-func libc_readdir_r_trampoline()
+var libc_readdir_r_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readdir_r readdir_r "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.s
index a5f96ffb07d..357989722cf 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.s
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.1_13.s
@@ -5,9 +5,21 @@
 // +build go1.13
 
 #include "textflag.h"
-TEXT ·libc_fdopendir_trampoline(SB),NOSPLIT,$0-0
+
+TEXT libc_fdopendir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fdopendir(SB)
-TEXT ·libc_closedir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fdopendir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fdopendir_trampoline_addr(SB)/8, $libc_fdopendir_trampoline<>(SB)
+
+TEXT libc_closedir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_closedir(SB)
-TEXT ·libc_readdir_r_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_closedir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_closedir_trampoline_addr(SB)/8, $libc_closedir_trampoline<>(SB)
+
+TEXT libc_readdir_r_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readdir_r(SB)
+
+GLOBL	·libc_readdir_r_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readdir_r_trampoline_addr(SB)/8, $libc_readdir_r_trampoline<>(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.go b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.go
index a10df58d00e..f2ee2bd33b9 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.go
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.go
@@ -16,7 +16,7 @@ var _ syscall.Errno
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getgroups_trampoline_addr, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -24,28 +24,28 @@ func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
 	return
 }
 
-func libc_getgroups_trampoline()
+var libc_getgroups_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getgroups getgroups "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setgroups(ngid int, gid *_Gid_t) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setgroups_trampoline_addr, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setgroups_trampoline()
+var libc_setgroups_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setgroups setgroups "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_wait4_trampoline), uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_wait4_trampoline_addr, uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
 	wpid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -53,14 +53,14 @@ func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err
 	return
 }
 
-func libc_wait4_trampoline()
+var libc_wait4_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_wait4 wait4 "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_accept_trampoline), uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	r0, _, e1 := syscall_syscall(libc_accept_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -68,42 +68,42 @@ func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
 	return
 }
 
-func libc_accept_trampoline()
+var libc_accept_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_accept accept "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_bind_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall_syscall(libc_bind_trampoline_addr, uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_bind_trampoline()
+var libc_bind_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_bind bind "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_connect_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall_syscall(libc_connect_trampoline_addr, uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_connect_trampoline()
+var libc_connect_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_connect connect "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socket(domain int, typ int, proto int) (fd int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_socket_trampoline), uintptr(domain), uintptr(typ), uintptr(proto))
+	r0, _, e1 := syscall_rawSyscall(libc_socket_trampoline_addr, uintptr(domain), uintptr(typ), uintptr(proto))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -111,91 +111,91 @@ func socket(domain int, typ int, proto int) (fd int, err error) {
 	return
 }
 
-func libc_socket_trampoline()
+var libc_socket_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_socket socket "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_getsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
+	_, _, e1 := syscall_syscall6(libc_getsockopt_trampoline_addr, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getsockopt_trampoline()
+var libc_getsockopt_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsockopt getsockopt "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
+	_, _, e1 := syscall_syscall6(libc_setsockopt_trampoline_addr, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setsockopt_trampoline()
+var libc_setsockopt_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setsockopt setsockopt "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getpeername_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := syscall_rawSyscall(libc_getpeername_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getpeername_trampoline()
+var libc_getpeername_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpeername getpeername "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getsockname_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := syscall_rawSyscall(libc_getsockname_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getsockname_trampoline()
+var libc_getsockname_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsockname getsockname "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Shutdown(s int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_shutdown_trampoline), uintptr(s), uintptr(how), 0)
+	_, _, e1 := syscall_syscall(libc_shutdown_trampoline_addr, uintptr(s), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_shutdown_trampoline()
+var libc_shutdown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_shutdown shutdown "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socketpair(domain int, typ int, proto int, fd *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall6(funcPC(libc_socketpair_trampoline), uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
+	_, _, e1 := syscall_rawSyscall6(libc_socketpair_trampoline_addr, uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_socketpair_trampoline()
+var libc_socketpair_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_socketpair socketpair "/usr/lib/libSystem.B.dylib"
 
@@ -208,7 +208,7 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_recvfrom_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
+	r0, _, e1 := syscall_syscall6(libc_recvfrom_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -216,7 +216,7 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	return
 }
 
-func libc_recvfrom_trampoline()
+var libc_recvfrom_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_recvfrom recvfrom "/usr/lib/libSystem.B.dylib"
 
@@ -229,21 +229,21 @@ func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendto_trampoline), uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
+	_, _, e1 := syscall_syscall6(libc_sendto_trampoline_addr, uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sendto_trampoline()
+var libc_sendto_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendto sendto "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_recvmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_recvmsg_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -251,14 +251,14 @@ func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
-func libc_recvmsg_trampoline()
+var libc_recvmsg_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_recvmsg recvmsg "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_sendmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_sendmsg_trampoline_addr, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -266,14 +266,14 @@ func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
-func libc_sendmsg_trampoline()
+var libc_sendmsg_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendmsg sendmsg "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_kevent_trampoline), uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
+	r0, _, e1 := syscall_syscall6(libc_kevent_trampoline_addr, uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -281,7 +281,7 @@ func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, ne
 	return
 }
 
-func libc_kevent_trampoline()
+var libc_kevent_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kevent kevent "/usr/lib/libSystem.B.dylib"
 
@@ -293,35 +293,35 @@ func utimes(path string, timeval *[2]Timeval) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_utimes_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall_syscall(libc_utimes_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_utimes_trampoline()
+var libc_utimes_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_utimes utimes "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func futimes(fd int, timeval *[2]Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_futimes_trampoline), uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall_syscall(libc_futimes_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_futimes_trampoline()
+var libc_futimes_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_futimes futimes "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_poll_trampoline), uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
+	r0, _, e1 := syscall_syscall(libc_poll_trampoline_addr, uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -329,7 +329,7 @@ func poll(fds *PollFd, nfds int, timeout int) (n int, err error) {
 	return
 }
 
-func libc_poll_trampoline()
+var libc_poll_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_poll poll "/usr/lib/libSystem.B.dylib"
 
@@ -342,14 +342,14 @@ func Madvise(b []byte, behav int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_madvise_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(behav))
+	_, _, e1 := syscall_syscall(libc_madvise_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(behav))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_madvise_trampoline()
+var libc_madvise_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_madvise madvise "/usr/lib/libSystem.B.dylib"
 
@@ -362,28 +362,28 @@ func Mlock(b []byte) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
+	_, _, e1 := syscall_syscall(libc_mlock_trampoline_addr, uintptr(_p0), uintptr(len(b)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mlock_trampoline()
+var libc_mlock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mlock mlock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Mlockall(flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_mlockall_trampoline), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall(libc_mlockall_trampoline_addr, uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mlockall_trampoline()
+var libc_mlockall_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mlockall mlockall "/usr/lib/libSystem.B.dylib"
 
@@ -396,14 +396,14 @@ func Mprotect(b []byte, prot int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mprotect_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(prot))
+	_, _, e1 := syscall_syscall(libc_mprotect_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(prot))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mprotect_trampoline()
+var libc_mprotect_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mprotect mprotect "/usr/lib/libSystem.B.dylib"
 
@@ -416,14 +416,14 @@ func Msync(b []byte, flags int) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_msync_trampoline), uintptr(_p0), uintptr(len(b)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_msync_trampoline_addr, uintptr(_p0), uintptr(len(b)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_msync_trampoline()
+var libc_msync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_msync msync "/usr/lib/libSystem.B.dylib"
 
@@ -436,42 +436,42 @@ func Munlock(b []byte) (err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_munlock_trampoline), uintptr(_p0), uintptr(len(b)), 0)
+	_, _, e1 := syscall_syscall(libc_munlock_trampoline_addr, uintptr(_p0), uintptr(len(b)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munlock_trampoline()
+var libc_munlock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munlock munlock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Munlockall() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munlockall_trampoline), 0, 0, 0)
+	_, _, e1 := syscall_syscall(libc_munlockall_trampoline_addr, 0, 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munlockall_trampoline()
+var libc_munlockall_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munlockall munlockall "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func pipe(p *[2]int32) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_pipe_trampoline), uintptr(unsafe.Pointer(p)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_pipe_trampoline_addr, uintptr(unsafe.Pointer(p)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_pipe_trampoline()
+var libc_pipe_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pipe pipe "/usr/lib/libSystem.B.dylib"
 
@@ -488,7 +488,7 @@ func getxattr(path string, attr string, dest *byte, size int, position uint32, o
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_getxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
+	r0, _, e1 := syscall_syscall6(libc_getxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -496,7 +496,7 @@ func getxattr(path string, attr string, dest *byte, size int, position uint32, o
 	return
 }
 
-func libc_getxattr_trampoline()
+var libc_getxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getxattr getxattr "/usr/lib/libSystem.B.dylib"
 
@@ -508,7 +508,7 @@ func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, optio
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_fgetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
+	r0, _, e1 := syscall_syscall6(libc_fgetxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(position), uintptr(options))
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -516,7 +516,7 @@ func fgetxattr(fd int, attr string, dest *byte, size int, position uint32, optio
 	return
 }
 
-func libc_fgetxattr_trampoline()
+var libc_fgetxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fgetxattr fgetxattr "/usr/lib/libSystem.B.dylib"
 
@@ -533,14 +533,14 @@ func setxattr(path string, attr string, data *byte, size int, position uint32, o
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_setxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
+	_, _, e1 := syscall_syscall6(libc_setxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setxattr_trampoline()
+var libc_setxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setxattr setxattr "/usr/lib/libSystem.B.dylib"
 
@@ -552,14 +552,14 @@ func fsetxattr(fd int, attr string, data *byte, size int, position uint32, optio
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fsetxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
+	_, _, e1 := syscall_syscall6(libc_fsetxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(data)), uintptr(size), uintptr(position), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fsetxattr_trampoline()
+var libc_fsetxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fsetxattr fsetxattr "/usr/lib/libSystem.B.dylib"
 
@@ -576,14 +576,14 @@ func removexattr(path string, attr string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_removexattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_removexattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_removexattr_trampoline()
+var libc_removexattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_removexattr removexattr "/usr/lib/libSystem.B.dylib"
 
@@ -595,14 +595,14 @@ func fremovexattr(fd int, attr string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_fremovexattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_fremovexattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fremovexattr_trampoline()
+var libc_fremovexattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fremovexattr fremovexattr "/usr/lib/libSystem.B.dylib"
 
@@ -614,7 +614,7 @@ func listxattr(path string, dest *byte, size int, options int) (sz int, err erro
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_listxattr_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_listxattr_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -622,14 +622,14 @@ func listxattr(path string, dest *byte, size int, options int) (sz int, err erro
 	return
 }
 
-func libc_listxattr_trampoline()
+var libc_listxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_listxattr listxattr "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_flistxattr_trampoline), uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_flistxattr_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(dest)), uintptr(size), uintptr(options), 0, 0)
 	sz = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -637,28 +637,28 @@ func flistxattr(fd int, dest *byte, size int, options int) (sz int, err error) {
 	return
 }
 
-func libc_flistxattr_trampoline()
+var libc_flistxattr_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_flistxattr flistxattr "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_setattrlist_trampoline), uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
+	_, _, e1 := syscall_syscall6(libc_setattrlist_trampoline_addr, uintptr(unsafe.Pointer(path)), uintptr(list), uintptr(buf), uintptr(size), uintptr(options), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setattrlist_trampoline()
+var libc_setattrlist_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setattrlist setattrlist "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func fcntl(fd int, cmd int, arg int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
+	r0, _, e1 := syscall_syscall(libc_fcntl_trampoline_addr, uintptr(fd), uintptr(cmd), uintptr(arg))
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -666,35 +666,35 @@ func fcntl(fd int, cmd int, arg int) (val int, err error) {
 	return
 }
 
-func libc_fcntl_trampoline()
+var libc_fcntl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fcntl fcntl "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func kill(pid int, signum int, posix int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_kill_trampoline), uintptr(pid), uintptr(signum), uintptr(posix))
+	_, _, e1 := syscall_syscall(libc_kill_trampoline_addr, uintptr(pid), uintptr(signum), uintptr(posix))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_kill_trampoline()
+var libc_kill_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kill kill "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ioctl(fd int, req uint, arg uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ioctl_trampoline), uintptr(fd), uintptr(req), uintptr(arg))
+	_, _, e1 := syscall_syscall(libc_ioctl_trampoline_addr, uintptr(fd), uintptr(req), uintptr(arg))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ioctl_trampoline()
+var libc_ioctl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ioctl ioctl "/usr/lib/libSystem.B.dylib"
 
@@ -707,28 +707,28 @@ func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr)
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_sysctl_trampoline), uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
+	_, _, e1 := syscall_syscall6(libc_sysctl_trampoline_addr, uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sysctl_trampoline()
+var libc_sysctl_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sysctl sysctl "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_sendfile_trampoline), uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
+	_, _, e1 := syscall_syscall6(libc_sendfile_trampoline_addr, uintptr(infd), uintptr(outfd), uintptr(offset), uintptr(unsafe.Pointer(len)), uintptr(hdtr), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sendfile_trampoline()
+var libc_sendfile_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sendfile sendfile "/usr/lib/libSystem.B.dylib"
 
@@ -740,28 +740,28 @@ func Access(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_access_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_access_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_access_trampoline()
+var libc_access_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_access access "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Adjtime(delta *Timeval, olddelta *Timeval) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_adjtime_trampoline), uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
+	_, _, e1 := syscall_syscall(libc_adjtime_trampoline_addr, uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_adjtime_trampoline()
+var libc_adjtime_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_adjtime adjtime "/usr/lib/libSystem.B.dylib"
 
@@ -773,14 +773,14 @@ func Chdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_chdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chdir_trampoline()
+var libc_chdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chdir chdir "/usr/lib/libSystem.B.dylib"
 
@@ -792,14 +792,14 @@ func Chflags(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chflags_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_chflags_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chflags_trampoline()
+var libc_chflags_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chflags chflags "/usr/lib/libSystem.B.dylib"
 
@@ -811,14 +811,14 @@ func Chmod(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chmod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_chmod_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chmod_trampoline()
+var libc_chmod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chmod chmod "/usr/lib/libSystem.B.dylib"
 
@@ -830,14 +830,14 @@ func Chown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_chown_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chown_trampoline()
+var libc_chown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chown chown "/usr/lib/libSystem.B.dylib"
 
@@ -849,42 +849,42 @@ func Chroot(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_chroot_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_chroot_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_chroot_trampoline()
+var libc_chroot_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_chroot chroot "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ClockGettime(clockid int32, time *Timespec) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_clock_gettime_trampoline), uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
+	_, _, e1 := syscall_syscall(libc_clock_gettime_trampoline_addr, uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clock_gettime_trampoline()
+var libc_clock_gettime_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clock_gettime clock_gettime "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Close(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_close_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_close_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_close_trampoline()
+var libc_close_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_close close "/usr/lib/libSystem.B.dylib"
 
@@ -901,14 +901,14 @@ func Clonefile(src string, dst string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_clonefile_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_clonefile_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clonefile_trampoline()
+var libc_clonefile_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clonefile clonefile "/usr/lib/libSystem.B.dylib"
 
@@ -925,21 +925,21 @@ func Clonefileat(srcDirfd int, src string, dstDirfd int, dst string, flags int)
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_clonefileat_trampoline), uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_clonefileat_trampoline_addr, uintptr(srcDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_clonefileat_trampoline()
+var libc_clonefileat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_clonefileat clonefileat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_dup_trampoline), uintptr(fd), 0, 0)
+	r0, _, e1 := syscall_syscall(libc_dup_trampoline_addr, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -947,21 +947,21 @@ func Dup(fd int) (nfd int, err error) {
 	return
 }
 
-func libc_dup_trampoline()
+var libc_dup_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_dup dup "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_dup2_trampoline), uintptr(from), uintptr(to), 0)
+	_, _, e1 := syscall_syscall(libc_dup2_trampoline_addr, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_dup2_trampoline()
+var libc_dup2_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_dup2 dup2 "/usr/lib/libSystem.B.dylib"
 
@@ -978,25 +978,25 @@ func Exchangedata(path1 string, path2 string, options int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_exchangedata_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
+	_, _, e1 := syscall_syscall(libc_exchangedata_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(options))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_exchangedata_trampoline()
+var libc_exchangedata_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_exchangedata exchangedata "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Exit(code int) {
-	syscall_syscall(funcPC(libc_exit_trampoline), uintptr(code), 0, 0)
+	syscall_syscall(libc_exit_trampoline_addr, uintptr(code), 0, 0)
 	return
 }
 
-func libc_exit_trampoline()
+var libc_exit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_exit exit "/usr/lib/libSystem.B.dylib"
 
@@ -1008,56 +1008,56 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_faccessat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_faccessat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_faccessat_trampoline()
+var libc_faccessat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_faccessat faccessat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchdir(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchdir_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_fchdir_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchdir_trampoline()
+var libc_fchdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchdir fchdir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchflags(fd int, flags int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchflags_trampoline), uintptr(fd), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_fchflags_trampoline_addr, uintptr(fd), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchflags_trampoline()
+var libc_fchflags_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchflags fchflags "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchmod(fd int, mode uint32) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchmod_trampoline), uintptr(fd), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_fchmod_trampoline_addr, uintptr(fd), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchmod_trampoline()
+var libc_fchmod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchmod fchmod "/usr/lib/libSystem.B.dylib"
 
@@ -1069,28 +1069,28 @@ func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchmodat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fchmodat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchmodat_trampoline()
+var libc_fchmodat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchmodat fchmodat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchown(fd int, uid int, gid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fchown_trampoline), uintptr(fd), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_fchown_trampoline_addr, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchown_trampoline()
+var libc_fchown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchown fchown "/usr/lib/libSystem.B.dylib"
 
@@ -1102,14 +1102,14 @@ func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fchownat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_fchownat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fchownat_trampoline()
+var libc_fchownat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fchownat fchownat "/usr/lib/libSystem.B.dylib"
 
@@ -1121,35 +1121,35 @@ func Fclonefileat(srcDirfd int, dstDirfd int, dst string, flags int) (err error)
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fclonefileat_trampoline), uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fclonefileat_trampoline_addr, uintptr(srcDirfd), uintptr(dstDirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fclonefileat_trampoline()
+var libc_fclonefileat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fclonefileat fclonefileat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Flock(fd int, how int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_flock_trampoline), uintptr(fd), uintptr(how), 0)
+	_, _, e1 := syscall_syscall(libc_flock_trampoline_addr, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_flock_trampoline()
+var libc_flock_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_flock flock "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fpathconf(fd int, name int) (val int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_fpathconf_trampoline), uintptr(fd), uintptr(name), 0)
+	r0, _, e1 := syscall_syscall(libc_fpathconf_trampoline_addr, uintptr(fd), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1157,35 +1157,35 @@ func Fpathconf(fd int, name int) (val int, err error) {
 	return
 }
 
-func libc_fpathconf_trampoline()
+var libc_fpathconf_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fpathconf fpathconf "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fsync(fd int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fsync_trampoline), uintptr(fd), 0, 0)
+	_, _, e1 := syscall_syscall(libc_fsync_trampoline_addr, uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fsync_trampoline()
+var libc_fsync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fsync fsync "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Ftruncate(fd int, length int64) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_ftruncate_trampoline), uintptr(fd), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_ftruncate_trampoline_addr, uintptr(fd), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ftruncate_trampoline()
+var libc_ftruncate_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ftruncate ftruncate "/usr/lib/libSystem.B.dylib"
 
@@ -1198,7 +1198,7 @@ func Getcwd(buf []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_getcwd_trampoline), uintptr(_p0), uintptr(len(buf)), 0)
+	r0, _, e1 := syscall_syscall(libc_getcwd_trampoline_addr, uintptr(_p0), uintptr(len(buf)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1206,62 +1206,62 @@ func Getcwd(buf []byte) (n int, err error) {
 	return
 }
 
-func libc_getcwd_trampoline()
+var libc_getcwd_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getcwd getcwd "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getdtablesize() (size int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_getdtablesize_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_syscall(libc_getdtablesize_trampoline_addr, 0, 0, 0)
 	size = int(r0)
 	return
 }
 
-func libc_getdtablesize_trampoline()
+var libc_getdtablesize_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getdtablesize getdtablesize "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getegid() (egid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getegid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getegid_trampoline_addr, 0, 0, 0)
 	egid = int(r0)
 	return
 }
 
-func libc_getegid_trampoline()
+var libc_getegid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getegid getegid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Geteuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_geteuid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_geteuid_trampoline_addr, 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
-func libc_geteuid_trampoline()
+var libc_geteuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_geteuid geteuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getgid() (gid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getgid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getgid_trampoline_addr, 0, 0, 0)
 	gid = int(r0)
 	return
 }
 
-func libc_getgid_trampoline()
+var libc_getgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getgid getgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgid(pid int) (pgid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getpgid_trampoline), uintptr(pid), 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getpgid_trampoline_addr, uintptr(pid), 0, 0)
 	pgid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1269,50 +1269,50 @@ func Getpgid(pid int) (pgid int, err error) {
 	return
 }
 
-func libc_getpgid_trampoline()
+var libc_getpgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpgid getpgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgrp() (pgrp int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpgrp_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getpgrp_trampoline_addr, 0, 0, 0)
 	pgrp = int(r0)
 	return
 }
 
-func libc_getpgrp_trampoline()
+var libc_getpgrp_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpgrp getpgrp "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpid() (pid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getpid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getpid_trampoline_addr, 0, 0, 0)
 	pid = int(r0)
 	return
 }
 
-func libc_getpid_trampoline()
+var libc_getpid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpid getpid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getppid() (ppid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getppid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getppid_trampoline_addr, 0, 0, 0)
 	ppid = int(r0)
 	return
 }
 
-func libc_getppid_trampoline()
+var libc_getppid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getppid getppid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpriority(which int, who int) (prio int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getpriority_trampoline), uintptr(which), uintptr(who), 0)
+	r0, _, e1 := syscall_syscall(libc_getpriority_trampoline_addr, uintptr(which), uintptr(who), 0)
 	prio = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1320,42 +1320,42 @@ func Getpriority(which int, who int) (prio int, err error) {
 	return
 }
 
-func libc_getpriority_trampoline()
+var libc_getpriority_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getpriority getpriority "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_getrlimit_trampoline_addr, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getrlimit_trampoline()
+var libc_getrlimit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getrlimit getrlimit "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrusage(who int, rusage *Rusage) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_getrusage_trampoline), uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_getrusage_trampoline_addr, uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_getrusage_trampoline()
+var libc_getrusage_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getrusage getrusage "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getsid(pid int) (sid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_getsid_trampoline), uintptr(pid), 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_getsid_trampoline_addr, uintptr(pid), 0, 0)
 	sid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1363,52 +1363,52 @@ func Getsid(pid int) (sid int, err error) {
 	return
 }
 
-func libc_getsid_trampoline()
+var libc_getsid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getsid getsid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Gettimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_gettimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_gettimeofday_trampoline_addr, uintptr(unsafe.Pointer(tp)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_gettimeofday_trampoline()
+var libc_gettimeofday_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getuid() (uid int) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_getuid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_getuid_trampoline_addr, 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
-func libc_getuid_trampoline()
+var libc_getuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getuid getuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Issetugid() (tainted bool) {
-	r0, _, _ := syscall_rawSyscall(funcPC(libc_issetugid_trampoline), 0, 0, 0)
+	r0, _, _ := syscall_rawSyscall(libc_issetugid_trampoline_addr, 0, 0, 0)
 	tainted = bool(r0 != 0)
 	return
 }
 
-func libc_issetugid_trampoline()
+var libc_issetugid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_issetugid issetugid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Kqueue() (fd int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_kqueue_trampoline), 0, 0, 0)
+	r0, _, e1 := syscall_syscall(libc_kqueue_trampoline_addr, 0, 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1416,7 +1416,7 @@ func Kqueue() (fd int, err error) {
 	return
 }
 
-func libc_kqueue_trampoline()
+var libc_kqueue_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_kqueue kqueue "/usr/lib/libSystem.B.dylib"
 
@@ -1428,14 +1428,14 @@ func Lchown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lchown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall_syscall(libc_lchown_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_lchown_trampoline()
+var libc_lchown_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lchown lchown "/usr/lib/libSystem.B.dylib"
 
@@ -1452,14 +1452,14 @@ func Link(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_link_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_link_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_link_trampoline()
+var libc_link_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_link link "/usr/lib/libSystem.B.dylib"
 
@@ -1476,28 +1476,28 @@ func Linkat(pathfd int, path string, linkfd int, link string, flags int) (err er
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_linkat_trampoline), uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall6(libc_linkat_trampoline_addr, uintptr(pathfd), uintptr(unsafe.Pointer(_p0)), uintptr(linkfd), uintptr(unsafe.Pointer(_p1)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_linkat_trampoline()
+var libc_linkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_linkat linkat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Listen(s int, backlog int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_listen_trampoline), uintptr(s), uintptr(backlog), 0)
+	_, _, e1 := syscall_syscall(libc_listen_trampoline_addr, uintptr(s), uintptr(backlog), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_listen_trampoline()
+var libc_listen_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_listen listen "/usr/lib/libSystem.B.dylib"
 
@@ -1509,14 +1509,14 @@ func Mkdir(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_mkdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkdir_trampoline()
+var libc_mkdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkdir mkdir "/usr/lib/libSystem.B.dylib"
 
@@ -1528,14 +1528,14 @@ func Mkdirat(dirfd int, path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkdirat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	_, _, e1 := syscall_syscall(libc_mkdirat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkdirat_trampoline()
+var libc_mkdirat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkdirat mkdirat "/usr/lib/libSystem.B.dylib"
 
@@ -1547,14 +1547,14 @@ func Mkfifo(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mkfifo_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall_syscall(libc_mkfifo_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mkfifo_trampoline()
+var libc_mkfifo_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mkfifo mkfifo "/usr/lib/libSystem.B.dylib"
 
@@ -1566,14 +1566,14 @@ func Mknod(path string, mode uint32, dev int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_mknod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
+	_, _, e1 := syscall_syscall(libc_mknod_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_mknod_trampoline()
+var libc_mknod_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mknod mknod "/usr/lib/libSystem.B.dylib"
 
@@ -1585,7 +1585,7 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_open_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
+	r0, _, e1 := syscall_syscall(libc_open_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1593,7 +1593,7 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	return
 }
 
-func libc_open_trampoline()
+var libc_open_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_open open "/usr/lib/libSystem.B.dylib"
 
@@ -1605,7 +1605,7 @@ func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_openat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_openat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1613,7 +1613,7 @@ func Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error) {
 	return
 }
 
-func libc_openat_trampoline()
+var libc_openat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_openat openat "/usr/lib/libSystem.B.dylib"
 
@@ -1625,7 +1625,7 @@ func Pathconf(path string, name int) (val int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_pathconf_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
+	r0, _, e1 := syscall_syscall(libc_pathconf_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1633,7 +1633,7 @@ func Pathconf(path string, name int) (val int, err error) {
 	return
 }
 
-func libc_pathconf_trampoline()
+var libc_pathconf_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pathconf pathconf "/usr/lib/libSystem.B.dylib"
 
@@ -1646,7 +1646,7 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pread_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_pread_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1654,7 +1654,7 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
-func libc_pread_trampoline()
+var libc_pread_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pread pread "/usr/lib/libSystem.B.dylib"
 
@@ -1667,7 +1667,7 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_pwrite_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_pwrite_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1675,7 +1675,7 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
-func libc_pwrite_trampoline()
+var libc_pwrite_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_pwrite pwrite "/usr/lib/libSystem.B.dylib"
 
@@ -1688,7 +1688,7 @@ func read(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall_syscall(libc_read_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1696,7 +1696,7 @@ func read(fd int, p []byte) (n int, err error) {
 	return
 }
 
-func libc_read_trampoline()
+var libc_read_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_read read "/usr/lib/libSystem.B.dylib"
 
@@ -1714,7 +1714,7 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	} else {
 		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_readlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
+	r0, _, e1 := syscall_syscall(libc_readlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1722,7 +1722,7 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	return
 }
 
-func libc_readlink_trampoline()
+var libc_readlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readlink readlink "/usr/lib/libSystem.B.dylib"
 
@@ -1740,7 +1740,7 @@ func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
 	} else {
 		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall6(funcPC(libc_readlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
+	r0, _, e1 := syscall_syscall6(libc_readlinkat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1748,7 +1748,7 @@ func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
 	return
 }
 
-func libc_readlinkat_trampoline()
+var libc_readlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_readlinkat readlinkat "/usr/lib/libSystem.B.dylib"
 
@@ -1765,14 +1765,14 @@ func Rename(from string, to string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rename_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_rename_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_rename_trampoline()
+var libc_rename_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_rename rename "/usr/lib/libSystem.B.dylib"
 
@@ -1789,14 +1789,14 @@ func Renameat(fromfd int, from string, tofd int, to string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_renameat_trampoline), uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_renameat_trampoline_addr, uintptr(fromfd), uintptr(unsafe.Pointer(_p0)), uintptr(tofd), uintptr(unsafe.Pointer(_p1)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_renameat_trampoline()
+var libc_renameat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_renameat renameat "/usr/lib/libSystem.B.dylib"
 
@@ -1808,14 +1808,14 @@ func Revoke(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_revoke_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_revoke_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_revoke_trampoline()
+var libc_revoke_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_revoke revoke "/usr/lib/libSystem.B.dylib"
 
@@ -1827,21 +1827,21 @@ func Rmdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_rmdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_rmdir_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_rmdir_trampoline()
+var libc_rmdir_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_rmdir rmdir "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_lseek_trampoline), uintptr(fd), uintptr(offset), uintptr(whence))
+	r0, _, e1 := syscall_syscall(libc_lseek_trampoline_addr, uintptr(fd), uintptr(offset), uintptr(whence))
 	newoffset = int64(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1849,14 +1849,14 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 	return
 }
 
-func libc_lseek_trampoline()
+var libc_lseek_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lseek lseek "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_select_trampoline), uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
+	r0, _, e1 := syscall_syscall6(libc_select_trampoline_addr, uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1864,49 +1864,49 @@ func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err
 	return
 }
 
-func libc_select_trampoline()
+var libc_select_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_select select "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setegid(egid int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setegid_trampoline), uintptr(egid), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setegid_trampoline_addr, uintptr(egid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setegid_trampoline()
+var libc_setegid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setegid setegid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Seteuid(euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_seteuid_trampoline), uintptr(euid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_seteuid_trampoline_addr, uintptr(euid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_seteuid_trampoline()
+var libc_seteuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_seteuid seteuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setgid(gid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setgid_trampoline), uintptr(gid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_setgid_trampoline_addr, uintptr(gid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setgid_trampoline()
+var libc_setgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setgid setgid "/usr/lib/libSystem.B.dylib"
 
@@ -1918,105 +1918,105 @@ func Setlogin(name string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_setlogin_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setlogin_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setlogin_trampoline()
+var libc_setlogin_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setlogin setlogin "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpgid(pid int, pgid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setpgid_trampoline), uintptr(pid), uintptr(pgid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setpgid_trampoline_addr, uintptr(pid), uintptr(pgid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setpgid_trampoline()
+var libc_setpgid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setpgid setpgid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpriority(which int, who int, prio int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setpriority_trampoline), uintptr(which), uintptr(who), uintptr(prio))
+	_, _, e1 := syscall_syscall(libc_setpriority_trampoline_addr, uintptr(which), uintptr(who), uintptr(prio))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setpriority_trampoline()
+var libc_setpriority_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setpriority setpriority "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setprivexec(flag int) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_setprivexec_trampoline), uintptr(flag), 0, 0)
+	_, _, e1 := syscall_syscall(libc_setprivexec_trampoline_addr, uintptr(flag), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setprivexec_trampoline()
+var libc_setprivexec_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setprivexec setprivexec "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setregid_trampoline), uintptr(rgid), uintptr(egid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setregid_trampoline_addr, uintptr(rgid), uintptr(egid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setregid_trampoline()
+var libc_setregid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setregid setregid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setreuid_trampoline), uintptr(ruid), uintptr(euid), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setreuid_trampoline_addr, uintptr(ruid), uintptr(euid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setreuid_trampoline()
+var libc_setreuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setreuid setreuid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := syscall_rawSyscall(libc_setrlimit_trampoline_addr, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setrlimit_trampoline()
+var libc_setrlimit_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setrlimit setrlimit "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setsid() (pid int, err error) {
-	r0, _, e1 := syscall_rawSyscall(funcPC(libc_setsid_trampoline), 0, 0, 0)
+	r0, _, e1 := syscall_rawSyscall(libc_setsid_trampoline_addr, 0, 0, 0)
 	pid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2024,35 +2024,35 @@ func Setsid() (pid int, err error) {
 	return
 }
 
-func libc_setsid_trampoline()
+var libc_setsid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setsid setsid "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Settimeofday(tp *Timeval) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_settimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_settimeofday_trampoline_addr, uintptr(unsafe.Pointer(tp)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_settimeofday_trampoline()
+var libc_settimeofday_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_settimeofday settimeofday "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setuid(uid int) (err error) {
-	_, _, e1 := syscall_rawSyscall(funcPC(libc_setuid_trampoline), uintptr(uid), 0, 0)
+	_, _, e1 := syscall_rawSyscall(libc_setuid_trampoline_addr, uintptr(uid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_setuid_trampoline()
+var libc_setuid_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_setuid setuid "/usr/lib/libSystem.B.dylib"
 
@@ -2069,14 +2069,14 @@ func Symlink(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall_syscall(libc_symlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_symlink_trampoline()
+var libc_symlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_symlink symlink "/usr/lib/libSystem.B.dylib"
 
@@ -2093,28 +2093,28 @@ func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_symlinkat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
+	_, _, e1 := syscall_syscall(libc_symlinkat_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(newdirfd), uintptr(unsafe.Pointer(_p1)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_symlinkat_trampoline()
+var libc_symlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_symlinkat symlinkat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Sync() (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_sync_trampoline), 0, 0, 0)
+	_, _, e1 := syscall_syscall(libc_sync_trampoline_addr, 0, 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_sync_trampoline()
+var libc_sync_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_sync sync "/usr/lib/libSystem.B.dylib"
 
@@ -2126,26 +2126,26 @@ func Truncate(path string, length int64) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_truncate_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_truncate_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_truncate_trampoline()
+var libc_truncate_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_truncate truncate "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Umask(newmask int) (oldmask int) {
-	r0, _, _ := syscall_syscall(funcPC(libc_umask_trampoline), uintptr(newmask), 0, 0)
+	r0, _, _ := syscall_syscall(libc_umask_trampoline_addr, uintptr(newmask), 0, 0)
 	oldmask = int(r0)
 	return
 }
 
-func libc_umask_trampoline()
+var libc_umask_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_umask umask "/usr/lib/libSystem.B.dylib"
 
@@ -2157,14 +2157,14 @@ func Undelete(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_undelete_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_undelete_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_undelete_trampoline()
+var libc_undelete_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_undelete undelete "/usr/lib/libSystem.B.dylib"
 
@@ -2176,14 +2176,14 @@ func Unlink(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlink_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall_syscall(libc_unlink_trampoline_addr, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unlink_trampoline()
+var libc_unlink_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unlink unlink "/usr/lib/libSystem.B.dylib"
 
@@ -2195,14 +2195,14 @@ func Unlinkat(dirfd int, path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unlinkat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
+	_, _, e1 := syscall_syscall(libc_unlinkat_trampoline_addr, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unlinkat_trampoline()
+var libc_unlinkat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unlinkat unlinkat "/usr/lib/libSystem.B.dylib"
 
@@ -2214,14 +2214,14 @@ func Unmount(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_unmount_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall_syscall(libc_unmount_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_unmount_trampoline()
+var libc_unmount_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_unmount unmount "/usr/lib/libSystem.B.dylib"
 
@@ -2234,7 +2234,7 @@ func write(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall_syscall(libc_write_trampoline_addr, uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2242,14 +2242,14 @@ func write(fd int, p []byte) (n int, err error) {
 	return
 }
 
-func libc_write_trampoline()
+var libc_write_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_write write "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error) {
-	r0, _, e1 := syscall_syscall6(funcPC(libc_mmap_trampoline), uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos))
+	r0, _, e1 := syscall_syscall6(libc_mmap_trampoline_addr, uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), uintptr(pos))
 	ret = uintptr(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2257,28 +2257,28 @@ func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (
 	return
 }
 
-func libc_mmap_trampoline()
+var libc_mmap_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_mmap mmap "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func munmap(addr uintptr, length uintptr) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_munmap_trampoline), uintptr(addr), uintptr(length), 0)
+	_, _, e1 := syscall_syscall(libc_munmap_trampoline_addr, uintptr(addr), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_munmap_trampoline()
+var libc_munmap_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_munmap munmap "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall_syscall(libc_read_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2289,7 +2289,7 @@ func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_write_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall_syscall(libc_write_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2300,14 +2300,14 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstat(fd int, stat *Stat_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_fstat_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstat_trampoline()
+var libc_fstat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstat fstat "/usr/lib/libSystem.B.dylib"
 
@@ -2319,35 +2319,35 @@ func Fstatat(fd int, path string, stat *Stat_t, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall6(funcPC(libc_fstatat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_fstatat_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstatat_trampoline()
+var libc_fstatat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstatat fstatat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstatfs(fd int, stat *Statfs_t) (err error) {
-	_, _, e1 := syscall_syscall(funcPC(libc_fstatfs_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_fstatfs_trampoline_addr, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_fstatfs_trampoline()
+var libc_fstatfs_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_fstatfs fstatfs "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
-	r0, _, e1 := syscall_syscall(funcPC(libc_getfsstat_trampoline), uintptr(buf), uintptr(size), uintptr(flags))
+	r0, _, e1 := syscall_syscall(libc_getfsstat_trampoline_addr, uintptr(buf), uintptr(size), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -2355,7 +2355,7 @@ func getfsstat(buf unsafe.Pointer, size uintptr, flags int) (n int, err error) {
 	return
 }
 
-func libc_getfsstat_trampoline()
+var libc_getfsstat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_getfsstat getfsstat "/usr/lib/libSystem.B.dylib"
 
@@ -2367,28 +2367,28 @@ func Lstat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_lstat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_lstat_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_lstat_trampoline()
+var libc_lstat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_lstat lstat "/usr/lib/libSystem.B.dylib"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func ptrace1(request int, pid int, addr uintptr, data uintptr) (err error) {
-	_, _, e1 := syscall_syscall6(funcPC(libc_ptrace_trampoline), uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
+	_, _, e1 := syscall_syscall6(libc_ptrace_trampoline_addr, uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_ptrace_trampoline()
+var libc_ptrace_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_ptrace ptrace "/usr/lib/libSystem.B.dylib"
 
@@ -2400,14 +2400,14 @@ func Stat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_stat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_stat_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_stat_trampoline()
+var libc_stat_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_stat stat "/usr/lib/libSystem.B.dylib"
 
@@ -2419,13 +2419,13 @@ func Statfs(path string, stat *Statfs_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := syscall_syscall(funcPC(libc_statfs_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall_syscall(libc_statfs_trampoline_addr, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-func libc_statfs_trampoline()
+var libc_statfs_trampoline_addr uintptr
 
 //go:cgo_import_dynamic libc_statfs statfs "/usr/lib/libSystem.B.dylib"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.s b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.s
index e30a6974071..33e19776db4 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.s
+++ b/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm64.s
@@ -5,287 +5,855 @@
 // +build go1.12
 
 #include "textflag.h"
-TEXT ·libc_getgroups_trampoline(SB),NOSPLIT,$0-0
+
+TEXT libc_getgroups_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getgroups(SB)
-TEXT ·libc_setgroups_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getgroups_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getgroups_trampoline_addr(SB)/8, $libc_getgroups_trampoline<>(SB)
+
+TEXT libc_setgroups_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setgroups(SB)
-TEXT ·libc_wait4_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setgroups_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setgroups_trampoline_addr(SB)/8, $libc_setgroups_trampoline<>(SB)
+
+TEXT libc_wait4_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_wait4(SB)
-TEXT ·libc_accept_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_wait4_trampoline_addr(SB), RODATA, $8
+DATA	·libc_wait4_trampoline_addr(SB)/8, $libc_wait4_trampoline<>(SB)
+
+TEXT libc_accept_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_accept(SB)
-TEXT ·libc_bind_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_accept_trampoline_addr(SB), RODATA, $8
+DATA	·libc_accept_trampoline_addr(SB)/8, $libc_accept_trampoline<>(SB)
+
+TEXT libc_bind_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_bind(SB)
-TEXT ·libc_connect_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_bind_trampoline_addr(SB), RODATA, $8
+DATA	·libc_bind_trampoline_addr(SB)/8, $libc_bind_trampoline<>(SB)
+
+TEXT libc_connect_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_connect(SB)
-TEXT ·libc_socket_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_connect_trampoline_addr(SB), RODATA, $8
+DATA	·libc_connect_trampoline_addr(SB)/8, $libc_connect_trampoline<>(SB)
+
+TEXT libc_socket_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_socket(SB)
-TEXT ·libc_getsockopt_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_socket_trampoline_addr(SB), RODATA, $8
+DATA	·libc_socket_trampoline_addr(SB)/8, $libc_socket_trampoline<>(SB)
+
+TEXT libc_getsockopt_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsockopt(SB)
-TEXT ·libc_setsockopt_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsockopt_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsockopt_trampoline_addr(SB)/8, $libc_getsockopt_trampoline<>(SB)
+
+TEXT libc_setsockopt_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setsockopt(SB)
-TEXT ·libc_getpeername_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setsockopt_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setsockopt_trampoline_addr(SB)/8, $libc_setsockopt_trampoline<>(SB)
+
+TEXT libc_getpeername_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpeername(SB)
-TEXT ·libc_getsockname_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpeername_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpeername_trampoline_addr(SB)/8, $libc_getpeername_trampoline<>(SB)
+
+TEXT libc_getsockname_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsockname(SB)
-TEXT ·libc_shutdown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsockname_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsockname_trampoline_addr(SB)/8, $libc_getsockname_trampoline<>(SB)
+
+TEXT libc_shutdown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_shutdown(SB)
-TEXT ·libc_socketpair_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_shutdown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_shutdown_trampoline_addr(SB)/8, $libc_shutdown_trampoline<>(SB)
+
+TEXT libc_socketpair_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_socketpair(SB)
-TEXT ·libc_recvfrom_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_socketpair_trampoline_addr(SB), RODATA, $8
+DATA	·libc_socketpair_trampoline_addr(SB)/8, $libc_socketpair_trampoline<>(SB)
+
+TEXT libc_recvfrom_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_recvfrom(SB)
-TEXT ·libc_sendto_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_recvfrom_trampoline_addr(SB), RODATA, $8
+DATA	·libc_recvfrom_trampoline_addr(SB)/8, $libc_recvfrom_trampoline<>(SB)
+
+TEXT libc_sendto_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendto(SB)
-TEXT ·libc_recvmsg_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendto_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendto_trampoline_addr(SB)/8, $libc_sendto_trampoline<>(SB)
+
+TEXT libc_recvmsg_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_recvmsg(SB)
-TEXT ·libc_sendmsg_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_recvmsg_trampoline_addr(SB), RODATA, $8
+DATA	·libc_recvmsg_trampoline_addr(SB)/8, $libc_recvmsg_trampoline<>(SB)
+
+TEXT libc_sendmsg_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendmsg(SB)
-TEXT ·libc_kevent_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendmsg_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendmsg_trampoline_addr(SB)/8, $libc_sendmsg_trampoline<>(SB)
+
+TEXT libc_kevent_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kevent(SB)
-TEXT ·libc_utimes_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kevent_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kevent_trampoline_addr(SB)/8, $libc_kevent_trampoline<>(SB)
+
+TEXT libc_utimes_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_utimes(SB)
-TEXT ·libc_futimes_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_utimes_trampoline_addr(SB), RODATA, $8
+DATA	·libc_utimes_trampoline_addr(SB)/8, $libc_utimes_trampoline<>(SB)
+
+TEXT libc_futimes_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_futimes(SB)
-TEXT ·libc_poll_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_futimes_trampoline_addr(SB), RODATA, $8
+DATA	·libc_futimes_trampoline_addr(SB)/8, $libc_futimes_trampoline<>(SB)
+
+TEXT libc_poll_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_poll(SB)
-TEXT ·libc_madvise_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_poll_trampoline_addr(SB), RODATA, $8
+DATA	·libc_poll_trampoline_addr(SB)/8, $libc_poll_trampoline<>(SB)
+
+TEXT libc_madvise_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_madvise(SB)
-TEXT ·libc_mlock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_madvise_trampoline_addr(SB), RODATA, $8
+DATA	·libc_madvise_trampoline_addr(SB)/8, $libc_madvise_trampoline<>(SB)
+
+TEXT libc_mlock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mlock(SB)
-TEXT ·libc_mlockall_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mlock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mlock_trampoline_addr(SB)/8, $libc_mlock_trampoline<>(SB)
+
+TEXT libc_mlockall_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mlockall(SB)
-TEXT ·libc_mprotect_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mlockall_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mlockall_trampoline_addr(SB)/8, $libc_mlockall_trampoline<>(SB)
+
+TEXT libc_mprotect_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mprotect(SB)
-TEXT ·libc_msync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mprotect_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mprotect_trampoline_addr(SB)/8, $libc_mprotect_trampoline<>(SB)
+
+TEXT libc_msync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_msync(SB)
-TEXT ·libc_munlock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_msync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_msync_trampoline_addr(SB)/8, $libc_msync_trampoline<>(SB)
+
+TEXT libc_munlock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munlock(SB)
-TEXT ·libc_munlockall_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munlock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munlock_trampoline_addr(SB)/8, $libc_munlock_trampoline<>(SB)
+
+TEXT libc_munlockall_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munlockall(SB)
-TEXT ·libc_pipe_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munlockall_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munlockall_trampoline_addr(SB)/8, $libc_munlockall_trampoline<>(SB)
+
+TEXT libc_pipe_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pipe(SB)
-TEXT ·libc_getxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pipe_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pipe_trampoline_addr(SB)/8, $libc_pipe_trampoline<>(SB)
+
+TEXT libc_getxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getxattr(SB)
-TEXT ·libc_fgetxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getxattr_trampoline_addr(SB)/8, $libc_getxattr_trampoline<>(SB)
+
+TEXT libc_fgetxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fgetxattr(SB)
-TEXT ·libc_setxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fgetxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fgetxattr_trampoline_addr(SB)/8, $libc_fgetxattr_trampoline<>(SB)
+
+TEXT libc_setxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setxattr(SB)
-TEXT ·libc_fsetxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setxattr_trampoline_addr(SB)/8, $libc_setxattr_trampoline<>(SB)
+
+TEXT libc_fsetxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fsetxattr(SB)
-TEXT ·libc_removexattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fsetxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fsetxattr_trampoline_addr(SB)/8, $libc_fsetxattr_trampoline<>(SB)
+
+TEXT libc_removexattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_removexattr(SB)
-TEXT ·libc_fremovexattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_removexattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_removexattr_trampoline_addr(SB)/8, $libc_removexattr_trampoline<>(SB)
+
+TEXT libc_fremovexattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fremovexattr(SB)
-TEXT ·libc_listxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fremovexattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fremovexattr_trampoline_addr(SB)/8, $libc_fremovexattr_trampoline<>(SB)
+
+TEXT libc_listxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_listxattr(SB)
-TEXT ·libc_flistxattr_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_listxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_listxattr_trampoline_addr(SB)/8, $libc_listxattr_trampoline<>(SB)
+
+TEXT libc_flistxattr_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_flistxattr(SB)
-TEXT ·libc_setattrlist_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_flistxattr_trampoline_addr(SB), RODATA, $8
+DATA	·libc_flistxattr_trampoline_addr(SB)/8, $libc_flistxattr_trampoline<>(SB)
+
+TEXT libc_setattrlist_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setattrlist(SB)
-TEXT ·libc_fcntl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setattrlist_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setattrlist_trampoline_addr(SB)/8, $libc_setattrlist_trampoline<>(SB)
+
+TEXT libc_fcntl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fcntl(SB)
-TEXT ·libc_kill_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fcntl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fcntl_trampoline_addr(SB)/8, $libc_fcntl_trampoline<>(SB)
+
+TEXT libc_kill_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kill(SB)
-TEXT ·libc_ioctl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kill_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kill_trampoline_addr(SB)/8, $libc_kill_trampoline<>(SB)
+
+TEXT libc_ioctl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ioctl(SB)
-TEXT ·libc_sysctl_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ioctl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ioctl_trampoline_addr(SB)/8, $libc_ioctl_trampoline<>(SB)
+
+TEXT libc_sysctl_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sysctl(SB)
-TEXT ·libc_sendfile_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sysctl_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sysctl_trampoline_addr(SB)/8, $libc_sysctl_trampoline<>(SB)
+
+TEXT libc_sendfile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sendfile(SB)
-TEXT ·libc_access_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sendfile_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sendfile_trampoline_addr(SB)/8, $libc_sendfile_trampoline<>(SB)
+
+TEXT libc_access_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_access(SB)
-TEXT ·libc_adjtime_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_access_trampoline_addr(SB), RODATA, $8
+DATA	·libc_access_trampoline_addr(SB)/8, $libc_access_trampoline<>(SB)
+
+TEXT libc_adjtime_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_adjtime(SB)
-TEXT ·libc_chdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_adjtime_trampoline_addr(SB), RODATA, $8
+DATA	·libc_adjtime_trampoline_addr(SB)/8, $libc_adjtime_trampoline<>(SB)
+
+TEXT libc_chdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chdir(SB)
-TEXT ·libc_chflags_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chdir_trampoline_addr(SB)/8, $libc_chdir_trampoline<>(SB)
+
+TEXT libc_chflags_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chflags(SB)
-TEXT ·libc_chmod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chflags_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chflags_trampoline_addr(SB)/8, $libc_chflags_trampoline<>(SB)
+
+TEXT libc_chmod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chmod(SB)
-TEXT ·libc_chown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chmod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chmod_trampoline_addr(SB)/8, $libc_chmod_trampoline<>(SB)
+
+TEXT libc_chown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chown(SB)
-TEXT ·libc_chroot_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chown_trampoline_addr(SB)/8, $libc_chown_trampoline<>(SB)
+
+TEXT libc_chroot_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_chroot(SB)
-TEXT ·libc_clock_gettime_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_chroot_trampoline_addr(SB), RODATA, $8
+DATA	·libc_chroot_trampoline_addr(SB)/8, $libc_chroot_trampoline<>(SB)
+
+TEXT libc_clock_gettime_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clock_gettime(SB)
-TEXT ·libc_close_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clock_gettime_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clock_gettime_trampoline_addr(SB)/8, $libc_clock_gettime_trampoline<>(SB)
+
+TEXT libc_close_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_close(SB)
-TEXT ·libc_clonefile_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_close_trampoline_addr(SB), RODATA, $8
+DATA	·libc_close_trampoline_addr(SB)/8, $libc_close_trampoline<>(SB)
+
+TEXT libc_clonefile_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clonefile(SB)
-TEXT ·libc_clonefileat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clonefile_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clonefile_trampoline_addr(SB)/8, $libc_clonefile_trampoline<>(SB)
+
+TEXT libc_clonefileat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_clonefileat(SB)
-TEXT ·libc_dup_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_clonefileat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_clonefileat_trampoline_addr(SB)/8, $libc_clonefileat_trampoline<>(SB)
+
+TEXT libc_dup_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_dup(SB)
-TEXT ·libc_dup2_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_dup_trampoline_addr(SB), RODATA, $8
+DATA	·libc_dup_trampoline_addr(SB)/8, $libc_dup_trampoline<>(SB)
+
+TEXT libc_dup2_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_dup2(SB)
-TEXT ·libc_exchangedata_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_dup2_trampoline_addr(SB), RODATA, $8
+DATA	·libc_dup2_trampoline_addr(SB)/8, $libc_dup2_trampoline<>(SB)
+
+TEXT libc_exchangedata_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_exchangedata(SB)
-TEXT ·libc_exit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_exchangedata_trampoline_addr(SB), RODATA, $8
+DATA	·libc_exchangedata_trampoline_addr(SB)/8, $libc_exchangedata_trampoline<>(SB)
+
+TEXT libc_exit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_exit(SB)
-TEXT ·libc_faccessat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_exit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_exit_trampoline_addr(SB)/8, $libc_exit_trampoline<>(SB)
+
+TEXT libc_faccessat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_faccessat(SB)
-TEXT ·libc_fchdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_faccessat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_faccessat_trampoline_addr(SB)/8, $libc_faccessat_trampoline<>(SB)
+
+TEXT libc_fchdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchdir(SB)
-TEXT ·libc_fchflags_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchdir_trampoline_addr(SB)/8, $libc_fchdir_trampoline<>(SB)
+
+TEXT libc_fchflags_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchflags(SB)
-TEXT ·libc_fchmod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchflags_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchflags_trampoline_addr(SB)/8, $libc_fchflags_trampoline<>(SB)
+
+TEXT libc_fchmod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchmod(SB)
-TEXT ·libc_fchmodat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchmod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchmod_trampoline_addr(SB)/8, $libc_fchmod_trampoline<>(SB)
+
+TEXT libc_fchmodat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchmodat(SB)
-TEXT ·libc_fchown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchmodat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchmodat_trampoline_addr(SB)/8, $libc_fchmodat_trampoline<>(SB)
+
+TEXT libc_fchown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchown(SB)
-TEXT ·libc_fchownat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchown_trampoline_addr(SB)/8, $libc_fchown_trampoline<>(SB)
+
+TEXT libc_fchownat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fchownat(SB)
-TEXT ·libc_fclonefileat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fchownat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fchownat_trampoline_addr(SB)/8, $libc_fchownat_trampoline<>(SB)
+
+TEXT libc_fclonefileat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fclonefileat(SB)
-TEXT ·libc_flock_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fclonefileat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fclonefileat_trampoline_addr(SB)/8, $libc_fclonefileat_trampoline<>(SB)
+
+TEXT libc_flock_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_flock(SB)
-TEXT ·libc_fpathconf_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_flock_trampoline_addr(SB), RODATA, $8
+DATA	·libc_flock_trampoline_addr(SB)/8, $libc_flock_trampoline<>(SB)
+
+TEXT libc_fpathconf_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fpathconf(SB)
-TEXT ·libc_fsync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fpathconf_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fpathconf_trampoline_addr(SB)/8, $libc_fpathconf_trampoline<>(SB)
+
+TEXT libc_fsync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fsync(SB)
-TEXT ·libc_ftruncate_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fsync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fsync_trampoline_addr(SB)/8, $libc_fsync_trampoline<>(SB)
+
+TEXT libc_ftruncate_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ftruncate(SB)
-TEXT ·libc_getcwd_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ftruncate_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ftruncate_trampoline_addr(SB)/8, $libc_ftruncate_trampoline<>(SB)
+
+TEXT libc_getcwd_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getcwd(SB)
-TEXT ·libc_getdtablesize_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getcwd_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getcwd_trampoline_addr(SB)/8, $libc_getcwd_trampoline<>(SB)
+
+TEXT libc_getdtablesize_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getdtablesize(SB)
-TEXT ·libc_getegid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getdtablesize_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getdtablesize_trampoline_addr(SB)/8, $libc_getdtablesize_trampoline<>(SB)
+
+TEXT libc_getegid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getegid(SB)
-TEXT ·libc_geteuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getegid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getegid_trampoline_addr(SB)/8, $libc_getegid_trampoline<>(SB)
+
+TEXT libc_geteuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_geteuid(SB)
-TEXT ·libc_getgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_geteuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_geteuid_trampoline_addr(SB)/8, $libc_geteuid_trampoline<>(SB)
+
+TEXT libc_getgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getgid(SB)
-TEXT ·libc_getpgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getgid_trampoline_addr(SB)/8, $libc_getgid_trampoline<>(SB)
+
+TEXT libc_getpgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpgid(SB)
-TEXT ·libc_getpgrp_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpgid_trampoline_addr(SB)/8, $libc_getpgid_trampoline<>(SB)
+
+TEXT libc_getpgrp_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpgrp(SB)
-TEXT ·libc_getpid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpgrp_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpgrp_trampoline_addr(SB)/8, $libc_getpgrp_trampoline<>(SB)
+
+TEXT libc_getpid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpid(SB)
-TEXT ·libc_getppid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpid_trampoline_addr(SB)/8, $libc_getpid_trampoline<>(SB)
+
+TEXT libc_getppid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getppid(SB)
-TEXT ·libc_getpriority_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getppid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getppid_trampoline_addr(SB)/8, $libc_getppid_trampoline<>(SB)
+
+TEXT libc_getpriority_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getpriority(SB)
-TEXT ·libc_getrlimit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getpriority_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getpriority_trampoline_addr(SB)/8, $libc_getpriority_trampoline<>(SB)
+
+TEXT libc_getrlimit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getrlimit(SB)
-TEXT ·libc_getrusage_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getrlimit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getrlimit_trampoline_addr(SB)/8, $libc_getrlimit_trampoline<>(SB)
+
+TEXT libc_getrusage_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getrusage(SB)
-TEXT ·libc_getsid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getrusage_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getrusage_trampoline_addr(SB)/8, $libc_getrusage_trampoline<>(SB)
+
+TEXT libc_getsid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getsid(SB)
-TEXT ·libc_gettimeofday_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getsid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getsid_trampoline_addr(SB)/8, $libc_getsid_trampoline<>(SB)
+
+TEXT libc_gettimeofday_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_gettimeofday(SB)
-TEXT ·libc_getuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_gettimeofday_trampoline_addr(SB), RODATA, $8
+DATA	·libc_gettimeofday_trampoline_addr(SB)/8, $libc_gettimeofday_trampoline<>(SB)
+
+TEXT libc_getuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getuid(SB)
-TEXT ·libc_issetugid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getuid_trampoline_addr(SB)/8, $libc_getuid_trampoline<>(SB)
+
+TEXT libc_issetugid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_issetugid(SB)
-TEXT ·libc_kqueue_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_issetugid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_issetugid_trampoline_addr(SB)/8, $libc_issetugid_trampoline<>(SB)
+
+TEXT libc_kqueue_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_kqueue(SB)
-TEXT ·libc_lchown_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_kqueue_trampoline_addr(SB), RODATA, $8
+DATA	·libc_kqueue_trampoline_addr(SB)/8, $libc_kqueue_trampoline<>(SB)
+
+TEXT libc_lchown_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lchown(SB)
-TEXT ·libc_link_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lchown_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lchown_trampoline_addr(SB)/8, $libc_lchown_trampoline<>(SB)
+
+TEXT libc_link_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_link(SB)
-TEXT ·libc_linkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_link_trampoline_addr(SB), RODATA, $8
+DATA	·libc_link_trampoline_addr(SB)/8, $libc_link_trampoline<>(SB)
+
+TEXT libc_linkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_linkat(SB)
-TEXT ·libc_listen_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_linkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_linkat_trampoline_addr(SB)/8, $libc_linkat_trampoline<>(SB)
+
+TEXT libc_listen_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_listen(SB)
-TEXT ·libc_mkdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_listen_trampoline_addr(SB), RODATA, $8
+DATA	·libc_listen_trampoline_addr(SB)/8, $libc_listen_trampoline<>(SB)
+
+TEXT libc_mkdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkdir(SB)
-TEXT ·libc_mkdirat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkdir_trampoline_addr(SB)/8, $libc_mkdir_trampoline<>(SB)
+
+TEXT libc_mkdirat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkdirat(SB)
-TEXT ·libc_mkfifo_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkdirat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkdirat_trampoline_addr(SB)/8, $libc_mkdirat_trampoline<>(SB)
+
+TEXT libc_mkfifo_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mkfifo(SB)
-TEXT ·libc_mknod_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mkfifo_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mkfifo_trampoline_addr(SB)/8, $libc_mkfifo_trampoline<>(SB)
+
+TEXT libc_mknod_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mknod(SB)
-TEXT ·libc_open_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mknod_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mknod_trampoline_addr(SB)/8, $libc_mknod_trampoline<>(SB)
+
+TEXT libc_open_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_open(SB)
-TEXT ·libc_openat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_open_trampoline_addr(SB), RODATA, $8
+DATA	·libc_open_trampoline_addr(SB)/8, $libc_open_trampoline<>(SB)
+
+TEXT libc_openat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_openat(SB)
-TEXT ·libc_pathconf_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_openat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_openat_trampoline_addr(SB)/8, $libc_openat_trampoline<>(SB)
+
+TEXT libc_pathconf_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pathconf(SB)
-TEXT ·libc_pread_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pathconf_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pathconf_trampoline_addr(SB)/8, $libc_pathconf_trampoline<>(SB)
+
+TEXT libc_pread_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pread(SB)
-TEXT ·libc_pwrite_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pread_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pread_trampoline_addr(SB)/8, $libc_pread_trampoline<>(SB)
+
+TEXT libc_pwrite_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_pwrite(SB)
-TEXT ·libc_read_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_pwrite_trampoline_addr(SB), RODATA, $8
+DATA	·libc_pwrite_trampoline_addr(SB)/8, $libc_pwrite_trampoline<>(SB)
+
+TEXT libc_read_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_read(SB)
-TEXT ·libc_readlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_read_trampoline_addr(SB), RODATA, $8
+DATA	·libc_read_trampoline_addr(SB)/8, $libc_read_trampoline<>(SB)
+
+TEXT libc_readlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readlink(SB)
-TEXT ·libc_readlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_readlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readlink_trampoline_addr(SB)/8, $libc_readlink_trampoline<>(SB)
+
+TEXT libc_readlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_readlinkat(SB)
-TEXT ·libc_rename_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_readlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_readlinkat_trampoline_addr(SB)/8, $libc_readlinkat_trampoline<>(SB)
+
+TEXT libc_rename_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_rename(SB)
-TEXT ·libc_renameat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_rename_trampoline_addr(SB), RODATA, $8
+DATA	·libc_rename_trampoline_addr(SB)/8, $libc_rename_trampoline<>(SB)
+
+TEXT libc_renameat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_renameat(SB)
-TEXT ·libc_revoke_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_renameat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_renameat_trampoline_addr(SB)/8, $libc_renameat_trampoline<>(SB)
+
+TEXT libc_revoke_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_revoke(SB)
-TEXT ·libc_rmdir_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_revoke_trampoline_addr(SB), RODATA, $8
+DATA	·libc_revoke_trampoline_addr(SB)/8, $libc_revoke_trampoline<>(SB)
+
+TEXT libc_rmdir_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_rmdir(SB)
-TEXT ·libc_lseek_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_rmdir_trampoline_addr(SB), RODATA, $8
+DATA	·libc_rmdir_trampoline_addr(SB)/8, $libc_rmdir_trampoline<>(SB)
+
+TEXT libc_lseek_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lseek(SB)
-TEXT ·libc_select_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lseek_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lseek_trampoline_addr(SB)/8, $libc_lseek_trampoline<>(SB)
+
+TEXT libc_select_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_select(SB)
-TEXT ·libc_setegid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_select_trampoline_addr(SB), RODATA, $8
+DATA	·libc_select_trampoline_addr(SB)/8, $libc_select_trampoline<>(SB)
+
+TEXT libc_setegid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setegid(SB)
-TEXT ·libc_seteuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setegid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setegid_trampoline_addr(SB)/8, $libc_setegid_trampoline<>(SB)
+
+TEXT libc_seteuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_seteuid(SB)
-TEXT ·libc_setgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_seteuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_seteuid_trampoline_addr(SB)/8, $libc_seteuid_trampoline<>(SB)
+
+TEXT libc_setgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setgid(SB)
-TEXT ·libc_setlogin_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setgid_trampoline_addr(SB)/8, $libc_setgid_trampoline<>(SB)
+
+TEXT libc_setlogin_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setlogin(SB)
-TEXT ·libc_setpgid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setlogin_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setlogin_trampoline_addr(SB)/8, $libc_setlogin_trampoline<>(SB)
+
+TEXT libc_setpgid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setpgid(SB)
-TEXT ·libc_setpriority_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setpgid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setpgid_trampoline_addr(SB)/8, $libc_setpgid_trampoline<>(SB)
+
+TEXT libc_setpriority_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setpriority(SB)
-TEXT ·libc_setprivexec_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setpriority_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setpriority_trampoline_addr(SB)/8, $libc_setpriority_trampoline<>(SB)
+
+TEXT libc_setprivexec_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setprivexec(SB)
-TEXT ·libc_setregid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setprivexec_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setprivexec_trampoline_addr(SB)/8, $libc_setprivexec_trampoline<>(SB)
+
+TEXT libc_setregid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setregid(SB)
-TEXT ·libc_setreuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setregid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setregid_trampoline_addr(SB)/8, $libc_setregid_trampoline<>(SB)
+
+TEXT libc_setreuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setreuid(SB)
-TEXT ·libc_setrlimit_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setreuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setreuid_trampoline_addr(SB)/8, $libc_setreuid_trampoline<>(SB)
+
+TEXT libc_setrlimit_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setrlimit(SB)
-TEXT ·libc_setsid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setrlimit_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setrlimit_trampoline_addr(SB)/8, $libc_setrlimit_trampoline<>(SB)
+
+TEXT libc_setsid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setsid(SB)
-TEXT ·libc_settimeofday_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setsid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setsid_trampoline_addr(SB)/8, $libc_setsid_trampoline<>(SB)
+
+TEXT libc_settimeofday_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_settimeofday(SB)
-TEXT ·libc_setuid_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_settimeofday_trampoline_addr(SB), RODATA, $8
+DATA	·libc_settimeofday_trampoline_addr(SB)/8, $libc_settimeofday_trampoline<>(SB)
+
+TEXT libc_setuid_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_setuid(SB)
-TEXT ·libc_symlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_setuid_trampoline_addr(SB), RODATA, $8
+DATA	·libc_setuid_trampoline_addr(SB)/8, $libc_setuid_trampoline<>(SB)
+
+TEXT libc_symlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_symlink(SB)
-TEXT ·libc_symlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_symlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_symlink_trampoline_addr(SB)/8, $libc_symlink_trampoline<>(SB)
+
+TEXT libc_symlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_symlinkat(SB)
-TEXT ·libc_sync_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_symlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_symlinkat_trampoline_addr(SB)/8, $libc_symlinkat_trampoline<>(SB)
+
+TEXT libc_sync_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_sync(SB)
-TEXT ·libc_truncate_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_sync_trampoline_addr(SB), RODATA, $8
+DATA	·libc_sync_trampoline_addr(SB)/8, $libc_sync_trampoline<>(SB)
+
+TEXT libc_truncate_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_truncate(SB)
-TEXT ·libc_umask_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_truncate_trampoline_addr(SB), RODATA, $8
+DATA	·libc_truncate_trampoline_addr(SB)/8, $libc_truncate_trampoline<>(SB)
+
+TEXT libc_umask_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_umask(SB)
-TEXT ·libc_undelete_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_umask_trampoline_addr(SB), RODATA, $8
+DATA	·libc_umask_trampoline_addr(SB)/8, $libc_umask_trampoline<>(SB)
+
+TEXT libc_undelete_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_undelete(SB)
-TEXT ·libc_unlink_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_undelete_trampoline_addr(SB), RODATA, $8
+DATA	·libc_undelete_trampoline_addr(SB)/8, $libc_undelete_trampoline<>(SB)
+
+TEXT libc_unlink_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unlink(SB)
-TEXT ·libc_unlinkat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unlink_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unlink_trampoline_addr(SB)/8, $libc_unlink_trampoline<>(SB)
+
+TEXT libc_unlinkat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unlinkat(SB)
-TEXT ·libc_unmount_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unlinkat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unlinkat_trampoline_addr(SB)/8, $libc_unlinkat_trampoline<>(SB)
+
+TEXT libc_unmount_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_unmount(SB)
-TEXT ·libc_write_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_unmount_trampoline_addr(SB), RODATA, $8
+DATA	·libc_unmount_trampoline_addr(SB)/8, $libc_unmount_trampoline<>(SB)
+
+TEXT libc_write_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_write(SB)
-TEXT ·libc_mmap_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_write_trampoline_addr(SB), RODATA, $8
+DATA	·libc_write_trampoline_addr(SB)/8, $libc_write_trampoline<>(SB)
+
+TEXT libc_mmap_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_mmap(SB)
-TEXT ·libc_munmap_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_mmap_trampoline_addr(SB), RODATA, $8
+DATA	·libc_mmap_trampoline_addr(SB)/8, $libc_mmap_trampoline<>(SB)
+
+TEXT libc_munmap_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_munmap(SB)
-TEXT ·libc_fstat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_munmap_trampoline_addr(SB), RODATA, $8
+DATA	·libc_munmap_trampoline_addr(SB)/8, $libc_munmap_trampoline<>(SB)
+
+TEXT libc_fstat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstat(SB)
-TEXT ·libc_fstatat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstat_trampoline_addr(SB)/8, $libc_fstat_trampoline<>(SB)
+
+TEXT libc_fstatat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstatat(SB)
-TEXT ·libc_fstatfs_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstatat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstatat_trampoline_addr(SB)/8, $libc_fstatat_trampoline<>(SB)
+
+TEXT libc_fstatfs_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_fstatfs(SB)
-TEXT ·libc_getfsstat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_fstatfs_trampoline_addr(SB), RODATA, $8
+DATA	·libc_fstatfs_trampoline_addr(SB)/8, $libc_fstatfs_trampoline<>(SB)
+
+TEXT libc_getfsstat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_getfsstat(SB)
-TEXT ·libc_lstat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_getfsstat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_getfsstat_trampoline_addr(SB)/8, $libc_getfsstat_trampoline<>(SB)
+
+TEXT libc_lstat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_lstat(SB)
-TEXT ·libc_ptrace_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_lstat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_lstat_trampoline_addr(SB)/8, $libc_lstat_trampoline<>(SB)
+
+TEXT libc_ptrace_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_ptrace(SB)
-TEXT ·libc_stat_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_ptrace_trampoline_addr(SB), RODATA, $8
+DATA	·libc_ptrace_trampoline_addr(SB)/8, $libc_ptrace_trampoline<>(SB)
+
+TEXT libc_stat_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_stat(SB)
-TEXT ·libc_statfs_trampoline(SB),NOSPLIT,$0-0
+
+GLOBL	·libc_stat_trampoline_addr(SB), RODATA, $8
+DATA	·libc_stat_trampoline_addr(SB)/8, $libc_stat_trampoline<>(SB)
+
+TEXT libc_statfs_trampoline<>(SB),NOSPLIT,$0-0
 	JMP	libc_statfs(SB)
+
+GLOBL	·libc_statfs_trampoline_addr(SB), RODATA, $8
+DATA	·libc_statfs_trampoline_addr(SB)/8, $libc_statfs_trampoline<>(SB)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_386.go b/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_386.go
deleted file mode 100644
index 1794ffc9245..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_386.go
+++ /dev/null
@@ -1,438 +0,0 @@
-// go run mksysnum.go /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/usr/include/sys/syscall.h
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build 386 && darwin
-// +build 386,darwin
-
-package unix
-
-// Deprecated: Use libSystem wrappers instead of direct syscalls.
-const (
-	SYS_SYSCALL                        = 0
-	SYS_EXIT                           = 1
-	SYS_FORK                           = 2
-	SYS_READ                           = 3
-	SYS_WRITE                          = 4
-	SYS_OPEN                           = 5
-	SYS_CLOSE                          = 6
-	SYS_WAIT4                          = 7
-	SYS_LINK                           = 9
-	SYS_UNLINK                         = 10
-	SYS_CHDIR                          = 12
-	SYS_FCHDIR                         = 13
-	SYS_MKNOD                          = 14
-	SYS_CHMOD                          = 15
-	SYS_CHOWN                          = 16
-	SYS_GETFSSTAT                      = 18
-	SYS_GETPID                         = 20
-	SYS_SETUID                         = 23
-	SYS_GETUID                         = 24
-	SYS_GETEUID                        = 25
-	SYS_PTRACE                         = 26
-	SYS_RECVMSG                        = 27
-	SYS_SENDMSG                        = 28
-	SYS_RECVFROM                       = 29
-	SYS_ACCEPT                         = 30
-	SYS_GETPEERNAME                    = 31
-	SYS_GETSOCKNAME                    = 32
-	SYS_ACCESS                         = 33
-	SYS_CHFLAGS                        = 34
-	SYS_FCHFLAGS                       = 35
-	SYS_SYNC                           = 36
-	SYS_KILL                           = 37
-	SYS_GETPPID                        = 39
-	SYS_DUP                            = 41
-	SYS_PIPE                           = 42
-	SYS_GETEGID                        = 43
-	SYS_SIGACTION                      = 46
-	SYS_GETGID                         = 47
-	SYS_SIGPROCMASK                    = 48
-	SYS_GETLOGIN                       = 49
-	SYS_SETLOGIN                       = 50
-	SYS_ACCT                           = 51
-	SYS_SIGPENDING                     = 52
-	SYS_SIGALTSTACK                    = 53
-	SYS_IOCTL                          = 54
-	SYS_REBOOT                         = 55
-	SYS_REVOKE                         = 56
-	SYS_SYMLINK                        = 57
-	SYS_READLINK                       = 58
-	SYS_EXECVE                         = 59
-	SYS_UMASK                          = 60
-	SYS_CHROOT                         = 61
-	SYS_MSYNC                          = 65
-	SYS_VFORK                          = 66
-	SYS_MUNMAP                         = 73
-	SYS_MPROTECT                       = 74
-	SYS_MADVISE                        = 75
-	SYS_MINCORE                        = 78
-	SYS_GETGROUPS                      = 79
-	SYS_SETGROUPS                      = 80
-	SYS_GETPGRP                        = 81
-	SYS_SETPGID                        = 82
-	SYS_SETITIMER                      = 83
-	SYS_SWAPON                         = 85
-	SYS_GETITIMER                      = 86
-	SYS_GETDTABLESIZE                  = 89
-	SYS_DUP2                           = 90
-	SYS_FCNTL                          = 92
-	SYS_SELECT                         = 93
-	SYS_FSYNC                          = 95
-	SYS_SETPRIORITY                    = 96
-	SYS_SOCKET                         = 97
-	SYS_CONNECT                        = 98
-	SYS_GETPRIORITY                    = 100
-	SYS_BIND                           = 104
-	SYS_SETSOCKOPT                     = 105
-	SYS_LISTEN                         = 106
-	SYS_SIGSUSPEND                     = 111
-	SYS_GETTIMEOFDAY                   = 116
-	SYS_GETRUSAGE                      = 117
-	SYS_GETSOCKOPT                     = 118
-	SYS_READV                          = 120
-	SYS_WRITEV                         = 121
-	SYS_SETTIMEOFDAY                   = 122
-	SYS_FCHOWN                         = 123
-	SYS_FCHMOD                         = 124
-	SYS_SETREUID                       = 126
-	SYS_SETREGID                       = 127
-	SYS_RENAME                         = 128
-	SYS_FLOCK                          = 131
-	SYS_MKFIFO                         = 132
-	SYS_SENDTO                         = 133
-	SYS_SHUTDOWN                       = 134
-	SYS_SOCKETPAIR                     = 135
-	SYS_MKDIR                          = 136
-	SYS_RMDIR                          = 137
-	SYS_UTIMES                         = 138
-	SYS_FUTIMES                        = 139
-	SYS_ADJTIME                        = 140
-	SYS_GETHOSTUUID                    = 142
-	SYS_SETSID                         = 147
-	SYS_GETPGID                        = 151
-	SYS_SETPRIVEXEC                    = 152
-	SYS_PREAD                          = 153
-	SYS_PWRITE                         = 154
-	SYS_NFSSVC                         = 155
-	SYS_STATFS                         = 157
-	SYS_FSTATFS                        = 158
-	SYS_UNMOUNT                        = 159
-	SYS_GETFH                          = 161
-	SYS_QUOTACTL                       = 165
-	SYS_MOUNT                          = 167
-	SYS_CSOPS                          = 169
-	SYS_CSOPS_AUDITTOKEN               = 170
-	SYS_WAITID                         = 173
-	SYS_KDEBUG_TYPEFILTER              = 177
-	SYS_KDEBUG_TRACE_STRING            = 178
-	SYS_KDEBUG_TRACE64                 = 179
-	SYS_KDEBUG_TRACE                   = 180
-	SYS_SETGID                         = 181
-	SYS_SETEGID                        = 182
-	SYS_SETEUID                        = 183
-	SYS_SIGRETURN                      = 184
-	SYS_THREAD_SELFCOUNTS              = 186
-	SYS_FDATASYNC                      = 187
-	SYS_STAT                           = 188
-	SYS_FSTAT                          = 189
-	SYS_LSTAT                          = 190
-	SYS_PATHCONF                       = 191
-	SYS_FPATHCONF                      = 192
-	SYS_GETRLIMIT                      = 194
-	SYS_SETRLIMIT                      = 195
-	SYS_GETDIRENTRIES                  = 196
-	SYS_MMAP                           = 197
-	SYS_LSEEK                          = 199
-	SYS_TRUNCATE                       = 200
-	SYS_FTRUNCATE                      = 201
-	SYS_SYSCTL                         = 202
-	SYS_MLOCK                          = 203
-	SYS_MUNLOCK                        = 204
-	SYS_UNDELETE                       = 205
-	SYS_OPEN_DPROTECTED_NP             = 216
-	SYS_GETATTRLIST                    = 220
-	SYS_SETATTRLIST                    = 221
-	SYS_GETDIRENTRIESATTR              = 222
-	SYS_EXCHANGEDATA                   = 223
-	SYS_SEARCHFS                       = 225
-	SYS_DELETE                         = 226
-	SYS_COPYFILE                       = 227
-	SYS_FGETATTRLIST                   = 228
-	SYS_FSETATTRLIST                   = 229
-	SYS_POLL                           = 230
-	SYS_WATCHEVENT                     = 231
-	SYS_WAITEVENT                      = 232
-	SYS_MODWATCH                       = 233
-	SYS_GETXATTR                       = 234
-	SYS_FGETXATTR                      = 235
-	SYS_SETXATTR                       = 236
-	SYS_FSETXATTR                      = 237
-	SYS_REMOVEXATTR                    = 238
-	SYS_FREMOVEXATTR                   = 239
-	SYS_LISTXATTR                      = 240
-	SYS_FLISTXATTR                     = 241
-	SYS_FSCTL                          = 242
-	SYS_INITGROUPS                     = 243
-	SYS_POSIX_SPAWN                    = 244
-	SYS_FFSCTL                         = 245
-	SYS_NFSCLNT                        = 247
-	SYS_FHOPEN                         = 248
-	SYS_MINHERIT                       = 250
-	SYS_SEMSYS                         = 251
-	SYS_MSGSYS                         = 252
-	SYS_SHMSYS                         = 253
-	SYS_SEMCTL                         = 254
-	SYS_SEMGET                         = 255
-	SYS_SEMOP                          = 256
-	SYS_MSGCTL                         = 258
-	SYS_MSGGET                         = 259
-	SYS_MSGSND                         = 260
-	SYS_MSGRCV                         = 261
-	SYS_SHMAT                          = 262
-	SYS_SHMCTL                         = 263
-	SYS_SHMDT                          = 264
-	SYS_SHMGET                         = 265
-	SYS_SHM_OPEN                       = 266
-	SYS_SHM_UNLINK                     = 267
-	SYS_SEM_OPEN                       = 268
-	SYS_SEM_CLOSE                      = 269
-	SYS_SEM_UNLINK                     = 270
-	SYS_SEM_WAIT                       = 271
-	SYS_SEM_TRYWAIT                    = 272
-	SYS_SEM_POST                       = 273
-	SYS_SYSCTLBYNAME                   = 274
-	SYS_OPEN_EXTENDED                  = 277
-	SYS_UMASK_EXTENDED                 = 278
-	SYS_STAT_EXTENDED                  = 279
-	SYS_LSTAT_EXTENDED                 = 280
-	SYS_FSTAT_EXTENDED                 = 281
-	SYS_CHMOD_EXTENDED                 = 282
-	SYS_FCHMOD_EXTENDED                = 283
-	SYS_ACCESS_EXTENDED                = 284
-	SYS_SETTID                         = 285
-	SYS_GETTID                         = 286
-	SYS_SETSGROUPS                     = 287
-	SYS_GETSGROUPS                     = 288
-	SYS_SETWGROUPS                     = 289
-	SYS_GETWGROUPS                     = 290
-	SYS_MKFIFO_EXTENDED                = 291
-	SYS_MKDIR_EXTENDED                 = 292
-	SYS_IDENTITYSVC                    = 293
-	SYS_SHARED_REGION_CHECK_NP         = 294
-	SYS_VM_PRESSURE_MONITOR            = 296
-	SYS_PSYNCH_RW_LONGRDLOCK           = 297
-	SYS_PSYNCH_RW_YIELDWRLOCK          = 298
-	SYS_PSYNCH_RW_DOWNGRADE            = 299
-	SYS_PSYNCH_RW_UPGRADE              = 300
-	SYS_PSYNCH_MUTEXWAIT               = 301
-	SYS_PSYNCH_MUTEXDROP               = 302
-	SYS_PSYNCH_CVBROAD                 = 303
-	SYS_PSYNCH_CVSIGNAL                = 304
-	SYS_PSYNCH_CVWAIT                  = 305
-	SYS_PSYNCH_RW_RDLOCK               = 306
-	SYS_PSYNCH_RW_WRLOCK               = 307
-	SYS_PSYNCH_RW_UNLOCK               = 308
-	SYS_PSYNCH_RW_UNLOCK2              = 309
-	SYS_GETSID                         = 310
-	SYS_SETTID_WITH_PID                = 311
-	SYS_PSYNCH_CVCLRPREPOST            = 312
-	SYS_AIO_FSYNC                      = 313
-	SYS_AIO_RETURN                     = 314
-	SYS_AIO_SUSPEND                    = 315
-	SYS_AIO_CANCEL                     = 316
-	SYS_AIO_ERROR                      = 317
-	SYS_AIO_READ                       = 318
-	SYS_AIO_WRITE                      = 319
-	SYS_LIO_LISTIO                     = 320
-	SYS_IOPOLICYSYS                    = 322
-	SYS_PROCESS_POLICY                 = 323
-	SYS_MLOCKALL                       = 324
-	SYS_MUNLOCKALL                     = 325
-	SYS_ISSETUGID                      = 327
-	SYS___PTHREAD_KILL                 = 328
-	SYS___PTHREAD_SIGMASK              = 329
-	SYS___SIGWAIT                      = 330
-	SYS___DISABLE_THREADSIGNAL         = 331
-	SYS___PTHREAD_MARKCANCEL           = 332
-	SYS___PTHREAD_CANCELED             = 333
-	SYS___SEMWAIT_SIGNAL               = 334
-	SYS_PROC_INFO                      = 336
-	SYS_SENDFILE                       = 337
-	SYS_STAT64                         = 338
-	SYS_FSTAT64                        = 339
-	SYS_LSTAT64                        = 340
-	SYS_STAT64_EXTENDED                = 341
-	SYS_LSTAT64_EXTENDED               = 342
-	SYS_FSTAT64_EXTENDED               = 343
-	SYS_GETDIRENTRIES64                = 344
-	SYS_STATFS64                       = 345
-	SYS_FSTATFS64                      = 346
-	SYS_GETFSSTAT64                    = 347
-	SYS___PTHREAD_CHDIR                = 348
-	SYS___PTHREAD_FCHDIR               = 349
-	SYS_AUDIT                          = 350
-	SYS_AUDITON                        = 351
-	SYS_GETAUID                        = 353
-	SYS_SETAUID                        = 354
-	SYS_GETAUDIT_ADDR                  = 357
-	SYS_SETAUDIT_ADDR                  = 358
-	SYS_AUDITCTL                       = 359
-	SYS_BSDTHREAD_CREATE               = 360
-	SYS_BSDTHREAD_TERMINATE            = 361
-	SYS_KQUEUE                         = 362
-	SYS_KEVENT                         = 363
-	SYS_LCHOWN                         = 364
-	SYS_BSDTHREAD_REGISTER             = 366
-	SYS_WORKQ_OPEN                     = 367
-	SYS_WORKQ_KERNRETURN               = 368
-	SYS_KEVENT64                       = 369
-	SYS___OLD_SEMWAIT_SIGNAL           = 370
-	SYS___OLD_SEMWAIT_SIGNAL_NOCANCEL  = 371
-	SYS_THREAD_SELFID                  = 372
-	SYS_LEDGER                         = 373
-	SYS_KEVENT_QOS                     = 374
-	SYS_KEVENT_ID                      = 375
-	SYS___MAC_EXECVE                   = 380
-	SYS___MAC_SYSCALL                  = 381
-	SYS___MAC_GET_FILE                 = 382
-	SYS___MAC_SET_FILE                 = 383
-	SYS___MAC_GET_LINK                 = 384
-	SYS___MAC_SET_LINK                 = 385
-	SYS___MAC_GET_PROC                 = 386
-	SYS___MAC_SET_PROC                 = 387
-	SYS___MAC_GET_FD                   = 388
-	SYS___MAC_SET_FD                   = 389
-	SYS___MAC_GET_PID                  = 390
-	SYS_PSELECT                        = 394
-	SYS_PSELECT_NOCANCEL               = 395
-	SYS_READ_NOCANCEL                  = 396
-	SYS_WRITE_NOCANCEL                 = 397
-	SYS_OPEN_NOCANCEL                  = 398
-	SYS_CLOSE_NOCANCEL                 = 399
-	SYS_WAIT4_NOCANCEL                 = 400
-	SYS_RECVMSG_NOCANCEL               = 401
-	SYS_SENDMSG_NOCANCEL               = 402
-	SYS_RECVFROM_NOCANCEL              = 403
-	SYS_ACCEPT_NOCANCEL                = 404
-	SYS_MSYNC_NOCANCEL                 = 405
-	SYS_FCNTL_NOCANCEL                 = 406
-	SYS_SELECT_NOCANCEL                = 407
-	SYS_FSYNC_NOCANCEL                 = 408
-	SYS_CONNECT_NOCANCEL               = 409
-	SYS_SIGSUSPEND_NOCANCEL            = 410
-	SYS_READV_NOCANCEL                 = 411
-	SYS_WRITEV_NOCANCEL                = 412
-	SYS_SENDTO_NOCANCEL                = 413
-	SYS_PREAD_NOCANCEL                 = 414
-	SYS_PWRITE_NOCANCEL                = 415
-	SYS_WAITID_NOCANCEL                = 416
-	SYS_POLL_NOCANCEL                  = 417
-	SYS_MSGSND_NOCANCEL                = 418
-	SYS_MSGRCV_NOCANCEL                = 419
-	SYS_SEM_WAIT_NOCANCEL              = 420
-	SYS_AIO_SUSPEND_NOCANCEL           = 421
-	SYS___SIGWAIT_NOCANCEL             = 422
-	SYS___SEMWAIT_SIGNAL_NOCANCEL      = 423
-	SYS___MAC_MOUNT                    = 424
-	SYS___MAC_GET_MOUNT                = 425
-	SYS___MAC_GETFSSTAT                = 426
-	SYS_FSGETPATH                      = 427
-	SYS_AUDIT_SESSION_SELF             = 428
-	SYS_AUDIT_SESSION_JOIN             = 429
-	SYS_FILEPORT_MAKEPORT              = 430
-	SYS_FILEPORT_MAKEFD                = 431
-	SYS_AUDIT_SESSION_PORT             = 432
-	SYS_PID_SUSPEND                    = 433
-	SYS_PID_RESUME                     = 434
-	SYS_PID_HIBERNATE                  = 435
-	SYS_PID_SHUTDOWN_SOCKETS           = 436
-	SYS_SHARED_REGION_MAP_AND_SLIDE_NP = 438
-	SYS_KAS_INFO                       = 439
-	SYS_MEMORYSTATUS_CONTROL           = 440
-	SYS_GUARDED_OPEN_NP                = 441
-	SYS_GUARDED_CLOSE_NP               = 442
-	SYS_GUARDED_KQUEUE_NP              = 443
-	SYS_CHANGE_FDGUARD_NP              = 444
-	SYS_USRCTL                         = 445
-	SYS_PROC_RLIMIT_CONTROL            = 446
-	SYS_CONNECTX                       = 447
-	SYS_DISCONNECTX                    = 448
-	SYS_PEELOFF                        = 449
-	SYS_SOCKET_DELEGATE                = 450
-	SYS_TELEMETRY                      = 451
-	SYS_PROC_UUID_POLICY               = 452
-	SYS_MEMORYSTATUS_GET_LEVEL         = 453
-	SYS_SYSTEM_OVERRIDE                = 454
-	SYS_VFS_PURGE                      = 455
-	SYS_SFI_CTL                        = 456
-	SYS_SFI_PIDCTL                     = 457
-	SYS_COALITION                      = 458
-	SYS_COALITION_INFO                 = 459
-	SYS_NECP_MATCH_POLICY              = 460
-	SYS_GETATTRLISTBULK                = 461
-	SYS_CLONEFILEAT                    = 462
-	SYS_OPENAT                         = 463
-	SYS_OPENAT_NOCANCEL                = 464
-	SYS_RENAMEAT                       = 465
-	SYS_FACCESSAT                      = 466
-	SYS_FCHMODAT                       = 467
-	SYS_FCHOWNAT                       = 468
-	SYS_FSTATAT                        = 469
-	SYS_FSTATAT64                      = 470
-	SYS_LINKAT                         = 471
-	SYS_UNLINKAT                       = 472
-	SYS_READLINKAT                     = 473
-	SYS_SYMLINKAT                      = 474
-	SYS_MKDIRAT                        = 475
-	SYS_GETATTRLISTAT                  = 476
-	SYS_PROC_TRACE_LOG                 = 477
-	SYS_BSDTHREAD_CTL                  = 478
-	SYS_OPENBYID_NP                    = 479
-	SYS_RECVMSG_X                      = 480
-	SYS_SENDMSG_X                      = 481
-	SYS_THREAD_SELFUSAGE               = 482
-	SYS_CSRCTL                         = 483
-	SYS_GUARDED_OPEN_DPROTECTED_NP     = 484
-	SYS_GUARDED_WRITE_NP               = 485
-	SYS_GUARDED_PWRITE_NP              = 486
-	SYS_GUARDED_WRITEV_NP              = 487
-	SYS_RENAMEATX_NP                   = 488
-	SYS_MREMAP_ENCRYPTED               = 489
-	SYS_NETAGENT_TRIGGER               = 490
-	SYS_STACK_SNAPSHOT_WITH_CONFIG     = 491
-	SYS_MICROSTACKSHOT                 = 492
-	SYS_GRAB_PGO_DATA                  = 493
-	SYS_PERSONA                        = 494
-	SYS_WORK_INTERVAL_CTL              = 499
-	SYS_GETENTROPY                     = 500
-	SYS_NECP_OPEN                      = 501
-	SYS_NECP_CLIENT_ACTION             = 502
-	SYS___NEXUS_OPEN                   = 503
-	SYS___NEXUS_REGISTER               = 504
-	SYS___NEXUS_DEREGISTER             = 505
-	SYS___NEXUS_CREATE                 = 506
-	SYS___NEXUS_DESTROY                = 507
-	SYS___NEXUS_GET_OPT                = 508
-	SYS___NEXUS_SET_OPT                = 509
-	SYS___CHANNEL_OPEN                 = 510
-	SYS___CHANNEL_GET_INFO             = 511
-	SYS___CHANNEL_SYNC                 = 512
-	SYS___CHANNEL_GET_OPT              = 513
-	SYS___CHANNEL_SET_OPT              = 514
-	SYS_ULOCK_WAIT                     = 515
-	SYS_ULOCK_WAKE                     = 516
-	SYS_FCLONEFILEAT                   = 517
-	SYS_FS_SNAPSHOT                    = 518
-	SYS_TERMINATE_WITH_PAYLOAD         = 520
-	SYS_ABORT_WITH_PAYLOAD             = 521
-	SYS_NECP_SESSION_OPEN              = 522
-	SYS_NECP_SESSION_ACTION            = 523
-	SYS_SETATTRLISTAT                  = 524
-	SYS_NET_QOS_GUIDELINE              = 525
-	SYS_FMOUNT                         = 526
-	SYS_NTP_ADJTIME                    = 527
-	SYS_NTP_GETTIME                    = 528
-	SYS_OS_FAULT_WITH_PAYLOAD          = 529
-	SYS_MAXSYSCALL                     = 530
-	SYS_INVALID                        = 63
-)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_arm.go b/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_arm.go
deleted file mode 100644
index 6dc736449a5..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsysnum_darwin_arm.go
+++ /dev/null
@@ -1,438 +0,0 @@
-// go run mksysnum.go /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.1.sdk/usr/include/sys/syscall.h
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build arm && darwin
-// +build arm,darwin
-
-package unix
-
-// Deprecated: Use libSystem wrappers instead of direct syscalls.
-const (
-	SYS_SYSCALL                        = 0
-	SYS_EXIT                           = 1
-	SYS_FORK                           = 2
-	SYS_READ                           = 3
-	SYS_WRITE                          = 4
-	SYS_OPEN                           = 5
-	SYS_CLOSE                          = 6
-	SYS_WAIT4                          = 7
-	SYS_LINK                           = 9
-	SYS_UNLINK                         = 10
-	SYS_CHDIR                          = 12
-	SYS_FCHDIR                         = 13
-	SYS_MKNOD                          = 14
-	SYS_CHMOD                          = 15
-	SYS_CHOWN                          = 16
-	SYS_GETFSSTAT                      = 18
-	SYS_GETPID                         = 20
-	SYS_SETUID                         = 23
-	SYS_GETUID                         = 24
-	SYS_GETEUID                        = 25
-	SYS_PTRACE                         = 26
-	SYS_RECVMSG                        = 27
-	SYS_SENDMSG                        = 28
-	SYS_RECVFROM                       = 29
-	SYS_ACCEPT                         = 30
-	SYS_GETPEERNAME                    = 31
-	SYS_GETSOCKNAME                    = 32
-	SYS_ACCESS                         = 33
-	SYS_CHFLAGS                        = 34
-	SYS_FCHFLAGS                       = 35
-	SYS_SYNC                           = 36
-	SYS_KILL                           = 37
-	SYS_GETPPID                        = 39
-	SYS_DUP                            = 41
-	SYS_PIPE                           = 42
-	SYS_GETEGID                        = 43
-	SYS_SIGACTION                      = 46
-	SYS_GETGID                         = 47
-	SYS_SIGPROCMASK                    = 48
-	SYS_GETLOGIN                       = 49
-	SYS_SETLOGIN                       = 50
-	SYS_ACCT                           = 51
-	SYS_SIGPENDING                     = 52
-	SYS_SIGALTSTACK                    = 53
-	SYS_IOCTL                          = 54
-	SYS_REBOOT                         = 55
-	SYS_REVOKE                         = 56
-	SYS_SYMLINK                        = 57
-	SYS_READLINK                       = 58
-	SYS_EXECVE                         = 59
-	SYS_UMASK                          = 60
-	SYS_CHROOT                         = 61
-	SYS_MSYNC                          = 65
-	SYS_VFORK                          = 66
-	SYS_MUNMAP                         = 73
-	SYS_MPROTECT                       = 74
-	SYS_MADVISE                        = 75
-	SYS_MINCORE                        = 78
-	SYS_GETGROUPS                      = 79
-	SYS_SETGROUPS                      = 80
-	SYS_GETPGRP                        = 81
-	SYS_SETPGID                        = 82
-	SYS_SETITIMER                      = 83
-	SYS_SWAPON                         = 85
-	SYS_GETITIMER                      = 86
-	SYS_GETDTABLESIZE                  = 89
-	SYS_DUP2                           = 90
-	SYS_FCNTL                          = 92
-	SYS_SELECT                         = 93
-	SYS_FSYNC                          = 95
-	SYS_SETPRIORITY                    = 96
-	SYS_SOCKET                         = 97
-	SYS_CONNECT                        = 98
-	SYS_GETPRIORITY                    = 100
-	SYS_BIND                           = 104
-	SYS_SETSOCKOPT                     = 105
-	SYS_LISTEN                         = 106
-	SYS_SIGSUSPEND                     = 111
-	SYS_GETTIMEOFDAY                   = 116
-	SYS_GETRUSAGE                      = 117
-	SYS_GETSOCKOPT                     = 118
-	SYS_READV                          = 120
-	SYS_WRITEV                         = 121
-	SYS_SETTIMEOFDAY                   = 122
-	SYS_FCHOWN                         = 123
-	SYS_FCHMOD                         = 124
-	SYS_SETREUID                       = 126
-	SYS_SETREGID                       = 127
-	SYS_RENAME                         = 128
-	SYS_FLOCK                          = 131
-	SYS_MKFIFO                         = 132
-	SYS_SENDTO                         = 133
-	SYS_SHUTDOWN                       = 134
-	SYS_SOCKETPAIR                     = 135
-	SYS_MKDIR                          = 136
-	SYS_RMDIR                          = 137
-	SYS_UTIMES                         = 138
-	SYS_FUTIMES                        = 139
-	SYS_ADJTIME                        = 140
-	SYS_GETHOSTUUID                    = 142
-	SYS_SETSID                         = 147
-	SYS_GETPGID                        = 151
-	SYS_SETPRIVEXEC                    = 152
-	SYS_PREAD                          = 153
-	SYS_PWRITE                         = 154
-	SYS_NFSSVC                         = 155
-	SYS_STATFS                         = 157
-	SYS_FSTATFS                        = 158
-	SYS_UNMOUNT                        = 159
-	SYS_GETFH                          = 161
-	SYS_QUOTACTL                       = 165
-	SYS_MOUNT                          = 167
-	SYS_CSOPS                          = 169
-	SYS_CSOPS_AUDITTOKEN               = 170
-	SYS_WAITID                         = 173
-	SYS_KDEBUG_TYPEFILTER              = 177
-	SYS_KDEBUG_TRACE_STRING            = 178
-	SYS_KDEBUG_TRACE64                 = 179
-	SYS_KDEBUG_TRACE                   = 180
-	SYS_SETGID                         = 181
-	SYS_SETEGID                        = 182
-	SYS_SETEUID                        = 183
-	SYS_SIGRETURN                      = 184
-	SYS_THREAD_SELFCOUNTS              = 186
-	SYS_FDATASYNC                      = 187
-	SYS_STAT                           = 188
-	SYS_FSTAT                          = 189
-	SYS_LSTAT                          = 190
-	SYS_PATHCONF                       = 191
-	SYS_FPATHCONF                      = 192
-	SYS_GETRLIMIT                      = 194
-	SYS_SETRLIMIT                      = 195
-	SYS_GETDIRENTRIES                  = 196
-	SYS_MMAP                           = 197
-	SYS_LSEEK                          = 199
-	SYS_TRUNCATE                       = 200
-	SYS_FTRUNCATE                      = 201
-	SYS_SYSCTL                         = 202
-	SYS_MLOCK                          = 203
-	SYS_MUNLOCK                        = 204
-	SYS_UNDELETE                       = 205
-	SYS_OPEN_DPROTECTED_NP             = 216
-	SYS_GETATTRLIST                    = 220
-	SYS_SETATTRLIST                    = 221
-	SYS_GETDIRENTRIESATTR              = 222
-	SYS_EXCHANGEDATA                   = 223
-	SYS_SEARCHFS                       = 225
-	SYS_DELETE                         = 226
-	SYS_COPYFILE                       = 227
-	SYS_FGETATTRLIST                   = 228
-	SYS_FSETATTRLIST                   = 229
-	SYS_POLL                           = 230
-	SYS_WATCHEVENT                     = 231
-	SYS_WAITEVENT                      = 232
-	SYS_MODWATCH                       = 233
-	SYS_GETXATTR                       = 234
-	SYS_FGETXATTR                      = 235
-	SYS_SETXATTR                       = 236
-	SYS_FSETXATTR                      = 237
-	SYS_REMOVEXATTR                    = 238
-	SYS_FREMOVEXATTR                   = 239
-	SYS_LISTXATTR                      = 240
-	SYS_FLISTXATTR                     = 241
-	SYS_FSCTL                          = 242
-	SYS_INITGROUPS                     = 243
-	SYS_POSIX_SPAWN                    = 244
-	SYS_FFSCTL                         = 245
-	SYS_NFSCLNT                        = 247
-	SYS_FHOPEN                         = 248
-	SYS_MINHERIT                       = 250
-	SYS_SEMSYS                         = 251
-	SYS_MSGSYS                         = 252
-	SYS_SHMSYS                         = 253
-	SYS_SEMCTL                         = 254
-	SYS_SEMGET                         = 255
-	SYS_SEMOP                          = 256
-	SYS_MSGCTL                         = 258
-	SYS_MSGGET                         = 259
-	SYS_MSGSND                         = 260
-	SYS_MSGRCV                         = 261
-	SYS_SHMAT                          = 262
-	SYS_SHMCTL                         = 263
-	SYS_SHMDT                          = 264
-	SYS_SHMGET                         = 265
-	SYS_SHM_OPEN                       = 266
-	SYS_SHM_UNLINK                     = 267
-	SYS_SEM_OPEN                       = 268
-	SYS_SEM_CLOSE                      = 269
-	SYS_SEM_UNLINK                     = 270
-	SYS_SEM_WAIT                       = 271
-	SYS_SEM_TRYWAIT                    = 272
-	SYS_SEM_POST                       = 273
-	SYS_SYSCTLBYNAME                   = 274
-	SYS_OPEN_EXTENDED                  = 277
-	SYS_UMASK_EXTENDED                 = 278
-	SYS_STAT_EXTENDED                  = 279
-	SYS_LSTAT_EXTENDED                 = 280
-	SYS_FSTAT_EXTENDED                 = 281
-	SYS_CHMOD_EXTENDED                 = 282
-	SYS_FCHMOD_EXTENDED                = 283
-	SYS_ACCESS_EXTENDED                = 284
-	SYS_SETTID                         = 285
-	SYS_GETTID                         = 286
-	SYS_SETSGROUPS                     = 287
-	SYS_GETSGROUPS                     = 288
-	SYS_SETWGROUPS                     = 289
-	SYS_GETWGROUPS                     = 290
-	SYS_MKFIFO_EXTENDED                = 291
-	SYS_MKDIR_EXTENDED                 = 292
-	SYS_IDENTITYSVC                    = 293
-	SYS_SHARED_REGION_CHECK_NP         = 294
-	SYS_VM_PRESSURE_MONITOR            = 296
-	SYS_PSYNCH_RW_LONGRDLOCK           = 297
-	SYS_PSYNCH_RW_YIELDWRLOCK          = 298
-	SYS_PSYNCH_RW_DOWNGRADE            = 299
-	SYS_PSYNCH_RW_UPGRADE              = 300
-	SYS_PSYNCH_MUTEXWAIT               = 301
-	SYS_PSYNCH_MUTEXDROP               = 302
-	SYS_PSYNCH_CVBROAD                 = 303
-	SYS_PSYNCH_CVSIGNAL                = 304
-	SYS_PSYNCH_CVWAIT                  = 305
-	SYS_PSYNCH_RW_RDLOCK               = 306
-	SYS_PSYNCH_RW_WRLOCK               = 307
-	SYS_PSYNCH_RW_UNLOCK               = 308
-	SYS_PSYNCH_RW_UNLOCK2              = 309
-	SYS_GETSID                         = 310
-	SYS_SETTID_WITH_PID                = 311
-	SYS_PSYNCH_CVCLRPREPOST            = 312
-	SYS_AIO_FSYNC                      = 313
-	SYS_AIO_RETURN                     = 314
-	SYS_AIO_SUSPEND                    = 315
-	SYS_AIO_CANCEL                     = 316
-	SYS_AIO_ERROR                      = 317
-	SYS_AIO_READ                       = 318
-	SYS_AIO_WRITE                      = 319
-	SYS_LIO_LISTIO                     = 320
-	SYS_IOPOLICYSYS                    = 322
-	SYS_PROCESS_POLICY                 = 323
-	SYS_MLOCKALL                       = 324
-	SYS_MUNLOCKALL                     = 325
-	SYS_ISSETUGID                      = 327
-	SYS___PTHREAD_KILL                 = 328
-	SYS___PTHREAD_SIGMASK              = 329
-	SYS___SIGWAIT                      = 330
-	SYS___DISABLE_THREADSIGNAL         = 331
-	SYS___PTHREAD_MARKCANCEL           = 332
-	SYS___PTHREAD_CANCELED             = 333
-	SYS___SEMWAIT_SIGNAL               = 334
-	SYS_PROC_INFO                      = 336
-	SYS_SENDFILE                       = 337
-	SYS_STAT64                         = 338
-	SYS_FSTAT64                        = 339
-	SYS_LSTAT64                        = 340
-	SYS_STAT64_EXTENDED                = 341
-	SYS_LSTAT64_EXTENDED               = 342
-	SYS_FSTAT64_EXTENDED               = 343
-	SYS_GETDIRENTRIES64                = 344
-	SYS_STATFS64                       = 345
-	SYS_FSTATFS64                      = 346
-	SYS_GETFSSTAT64                    = 347
-	SYS___PTHREAD_CHDIR                = 348
-	SYS___PTHREAD_FCHDIR               = 349
-	SYS_AUDIT                          = 350
-	SYS_AUDITON                        = 351
-	SYS_GETAUID                        = 353
-	SYS_SETAUID                        = 354
-	SYS_GETAUDIT_ADDR                  = 357
-	SYS_SETAUDIT_ADDR                  = 358
-	SYS_AUDITCTL                       = 359
-	SYS_BSDTHREAD_CREATE               = 360
-	SYS_BSDTHREAD_TERMINATE            = 361
-	SYS_KQUEUE                         = 362
-	SYS_KEVENT                         = 363
-	SYS_LCHOWN                         = 364
-	SYS_BSDTHREAD_REGISTER             = 366
-	SYS_WORKQ_OPEN                     = 367
-	SYS_WORKQ_KERNRETURN               = 368
-	SYS_KEVENT64                       = 369
-	SYS___OLD_SEMWAIT_SIGNAL           = 370
-	SYS___OLD_SEMWAIT_SIGNAL_NOCANCEL  = 371
-	SYS_THREAD_SELFID                  = 372
-	SYS_LEDGER                         = 373
-	SYS_KEVENT_QOS                     = 374
-	SYS_KEVENT_ID                      = 375
-	SYS___MAC_EXECVE                   = 380
-	SYS___MAC_SYSCALL                  = 381
-	SYS___MAC_GET_FILE                 = 382
-	SYS___MAC_SET_FILE                 = 383
-	SYS___MAC_GET_LINK                 = 384
-	SYS___MAC_SET_LINK                 = 385
-	SYS___MAC_GET_PROC                 = 386
-	SYS___MAC_SET_PROC                 = 387
-	SYS___MAC_GET_FD                   = 388
-	SYS___MAC_SET_FD                   = 389
-	SYS___MAC_GET_PID                  = 390
-	SYS_PSELECT                        = 394
-	SYS_PSELECT_NOCANCEL               = 395
-	SYS_READ_NOCANCEL                  = 396
-	SYS_WRITE_NOCANCEL                 = 397
-	SYS_OPEN_NOCANCEL                  = 398
-	SYS_CLOSE_NOCANCEL                 = 399
-	SYS_WAIT4_NOCANCEL                 = 400
-	SYS_RECVMSG_NOCANCEL               = 401
-	SYS_SENDMSG_NOCANCEL               = 402
-	SYS_RECVFROM_NOCANCEL              = 403
-	SYS_ACCEPT_NOCANCEL                = 404
-	SYS_MSYNC_NOCANCEL                 = 405
-	SYS_FCNTL_NOCANCEL                 = 406
-	SYS_SELECT_NOCANCEL                = 407
-	SYS_FSYNC_NOCANCEL                 = 408
-	SYS_CONNECT_NOCANCEL               = 409
-	SYS_SIGSUSPEND_NOCANCEL            = 410
-	SYS_READV_NOCANCEL                 = 411
-	SYS_WRITEV_NOCANCEL                = 412
-	SYS_SENDTO_NOCANCEL                = 413
-	SYS_PREAD_NOCANCEL                 = 414
-	SYS_PWRITE_NOCANCEL                = 415
-	SYS_WAITID_NOCANCEL                = 416
-	SYS_POLL_NOCANCEL                  = 417
-	SYS_MSGSND_NOCANCEL                = 418
-	SYS_MSGRCV_NOCANCEL                = 419
-	SYS_SEM_WAIT_NOCANCEL              = 420
-	SYS_AIO_SUSPEND_NOCANCEL           = 421
-	SYS___SIGWAIT_NOCANCEL             = 422
-	SYS___SEMWAIT_SIGNAL_NOCANCEL      = 423
-	SYS___MAC_MOUNT                    = 424
-	SYS___MAC_GET_MOUNT                = 425
-	SYS___MAC_GETFSSTAT                = 426
-	SYS_FSGETPATH                      = 427
-	SYS_AUDIT_SESSION_SELF             = 428
-	SYS_AUDIT_SESSION_JOIN             = 429
-	SYS_FILEPORT_MAKEPORT              = 430
-	SYS_FILEPORT_MAKEFD                = 431
-	SYS_AUDIT_SESSION_PORT             = 432
-	SYS_PID_SUSPEND                    = 433
-	SYS_PID_RESUME                     = 434
-	SYS_PID_HIBERNATE                  = 435
-	SYS_PID_SHUTDOWN_SOCKETS           = 436
-	SYS_SHARED_REGION_MAP_AND_SLIDE_NP = 438
-	SYS_KAS_INFO                       = 439
-	SYS_MEMORYSTATUS_CONTROL           = 440
-	SYS_GUARDED_OPEN_NP                = 441
-	SYS_GUARDED_CLOSE_NP               = 442
-	SYS_GUARDED_KQUEUE_NP              = 443
-	SYS_CHANGE_FDGUARD_NP              = 444
-	SYS_USRCTL                         = 445
-	SYS_PROC_RLIMIT_CONTROL            = 446
-	SYS_CONNECTX                       = 447
-	SYS_DISCONNECTX                    = 448
-	SYS_PEELOFF                        = 449
-	SYS_SOCKET_DELEGATE                = 450
-	SYS_TELEMETRY                      = 451
-	SYS_PROC_UUID_POLICY               = 452
-	SYS_MEMORYSTATUS_GET_LEVEL         = 453
-	SYS_SYSTEM_OVERRIDE                = 454
-	SYS_VFS_PURGE                      = 455
-	SYS_SFI_CTL                        = 456
-	SYS_SFI_PIDCTL                     = 457
-	SYS_COALITION                      = 458
-	SYS_COALITION_INFO                 = 459
-	SYS_NECP_MATCH_POLICY              = 460
-	SYS_GETATTRLISTBULK                = 461
-	SYS_CLONEFILEAT                    = 462
-	SYS_OPENAT                         = 463
-	SYS_OPENAT_NOCANCEL                = 464
-	SYS_RENAMEAT                       = 465
-	SYS_FACCESSAT                      = 466
-	SYS_FCHMODAT                       = 467
-	SYS_FCHOWNAT                       = 468
-	SYS_FSTATAT                        = 469
-	SYS_FSTATAT64                      = 470
-	SYS_LINKAT                         = 471
-	SYS_UNLINKAT                       = 472
-	SYS_READLINKAT                     = 473
-	SYS_SYMLINKAT                      = 474
-	SYS_MKDIRAT                        = 475
-	SYS_GETATTRLISTAT                  = 476
-	SYS_PROC_TRACE_LOG                 = 477
-	SYS_BSDTHREAD_CTL                  = 478
-	SYS_OPENBYID_NP                    = 479
-	SYS_RECVMSG_X                      = 480
-	SYS_SENDMSG_X                      = 481
-	SYS_THREAD_SELFUSAGE               = 482
-	SYS_CSRCTL                         = 483
-	SYS_GUARDED_OPEN_DPROTECTED_NP     = 484
-	SYS_GUARDED_WRITE_NP               = 485
-	SYS_GUARDED_PWRITE_NP              = 486
-	SYS_GUARDED_WRITEV_NP              = 487
-	SYS_RENAMEATX_NP                   = 488
-	SYS_MREMAP_ENCRYPTED               = 489
-	SYS_NETAGENT_TRIGGER               = 490
-	SYS_STACK_SNAPSHOT_WITH_CONFIG     = 491
-	SYS_MICROSTACKSHOT                 = 492
-	SYS_GRAB_PGO_DATA                  = 493
-	SYS_PERSONA                        = 494
-	SYS_WORK_INTERVAL_CTL              = 499
-	SYS_GETENTROPY                     = 500
-	SYS_NECP_OPEN                      = 501
-	SYS_NECP_CLIENT_ACTION             = 502
-	SYS___NEXUS_OPEN                   = 503
-	SYS___NEXUS_REGISTER               = 504
-	SYS___NEXUS_DEREGISTER             = 505
-	SYS___NEXUS_CREATE                 = 506
-	SYS___NEXUS_DESTROY                = 507
-	SYS___NEXUS_GET_OPT                = 508
-	SYS___NEXUS_SET_OPT                = 509
-	SYS___CHANNEL_OPEN                 = 510
-	SYS___CHANNEL_GET_INFO             = 511
-	SYS___CHANNEL_SYNC                 = 512
-	SYS___CHANNEL_GET_OPT              = 513
-	SYS___CHANNEL_SET_OPT              = 514
-	SYS_ULOCK_WAIT                     = 515
-	SYS_ULOCK_WAKE                     = 516
-	SYS_FCLONEFILEAT                   = 517
-	SYS_FS_SNAPSHOT                    = 518
-	SYS_TERMINATE_WITH_PAYLOAD         = 520
-	SYS_ABORT_WITH_PAYLOAD             = 521
-	SYS_NECP_SESSION_OPEN              = 522
-	SYS_NECP_SESSION_ACTION            = 523
-	SYS_SETATTRLISTAT                  = 524
-	SYS_NET_QOS_GUIDELINE              = 525
-	SYS_FMOUNT                         = 526
-	SYS_NTP_ADJTIME                    = 527
-	SYS_NTP_GETTIME                    = 528
-	SYS_OS_FAULT_WITH_PAYLOAD          = 529
-	SYS_MAXSYSCALL                     = 530
-	SYS_INVALID                        = 63
-)
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_386.go b/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_386.go
deleted file mode 100644
index 883b64a2723..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_386.go
+++ /dev/null
@@ -1,524 +0,0 @@
-// cgo -godefs types_darwin.go | go run mkpost.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build 386 && darwin
-// +build 386,darwin
-
-package unix
-
-const (
-	SizeofPtr      = 0x4
-	SizeofShort    = 0x2
-	SizeofInt      = 0x4
-	SizeofLong     = 0x4
-	SizeofLongLong = 0x8
-)
-
-type (
-	_C_short     int16
-	_C_int       int32
-	_C_long      int32
-	_C_long_long int64
-)
-
-type Timespec struct {
-	Sec  int32
-	Nsec int32
-}
-
-type Timeval struct {
-	Sec  int32
-	Usec int32
-}
-
-type Timeval32 struct{}
-
-type Rusage struct {
-	Utime    Timeval
-	Stime    Timeval
-	Maxrss   int32
-	Ixrss    int32
-	Idrss    int32
-	Isrss    int32
-	Minflt   int32
-	Majflt   int32
-	Nswap    int32
-	Inblock  int32
-	Oublock  int32
-	Msgsnd   int32
-	Msgrcv   int32
-	Nsignals int32
-	Nvcsw    int32
-	Nivcsw   int32
-}
-
-type Rlimit struct {
-	Cur uint64
-	Max uint64
-}
-
-type _Gid_t uint32
-
-type Stat_t struct {
-	Dev     int32
-	Mode    uint16
-	Nlink   uint16
-	Ino     uint64
-	Uid     uint32
-	Gid     uint32
-	Rdev    int32
-	Atim    Timespec
-	Mtim    Timespec
-	Ctim    Timespec
-	Btim    Timespec
-	Size    int64
-	Blocks  int64
-	Blksize int32
-	Flags   uint32
-	Gen     uint32
-	Lspare  int32
-	Qspare  [2]int64
-}
-
-type Statfs_t struct {
-	Bsize       uint32
-	Iosize      int32
-	Blocks      uint64
-	Bfree       uint64
-	Bavail      uint64
-	Files       uint64
-	Ffree       uint64
-	Fsid        Fsid
-	Owner       uint32
-	Type        uint32
-	Flags       uint32
-	Fssubtype   uint32
-	Fstypename  [16]byte
-	Mntonname   [1024]byte
-	Mntfromname [1024]byte
-	Reserved    [8]uint32
-}
-
-type Flock_t struct {
-	Start  int64
-	Len    int64
-	Pid    int32
-	Type   int16
-	Whence int16
-}
-
-type Fstore_t struct {
-	Flags      uint32
-	Posmode    int32
-	Offset     int64
-	Length     int64
-	Bytesalloc int64
-}
-
-type Radvisory_t struct {
-	Offset int64
-	Count  int32
-}
-
-type Fbootstraptransfer_t struct {
-	Offset int64
-	Length uint32
-	Buffer *byte
-}
-
-type Log2phys_t struct {
-	Flags       uint32
-	Contigbytes int64
-	Devoffset   int64
-}
-
-type Fsid struct {
-	Val [2]int32
-}
-
-type Dirent struct {
-	Ino     uint64
-	Seekoff uint64
-	Reclen  uint16
-	Namlen  uint16
-	Type    uint8
-	Name    [1024]int8
-	_       [3]byte
-}
-
-const (
-	PathMax = 0x400
-)
-
-type RawSockaddrInet4 struct {
-	Len    uint8
-	Family uint8
-	Port   uint16
-	Addr   [4]byte /* in_addr */
-	Zero   [8]int8
-}
-
-type RawSockaddrInet6 struct {
-	Len      uint8
-	Family   uint8
-	Port     uint16
-	Flowinfo uint32
-	Addr     [16]byte /* in6_addr */
-	Scope_id uint32
-}
-
-type RawSockaddrUnix struct {
-	Len    uint8
-	Family uint8
-	Path   [104]int8
-}
-
-type RawSockaddrDatalink struct {
-	Len    uint8
-	Family uint8
-	Index  uint16
-	Type   uint8
-	Nlen   uint8
-	Alen   uint8
-	Slen   uint8
-	Data   [12]int8
-}
-
-type RawSockaddr struct {
-	Len    uint8
-	Family uint8
-	Data   [14]int8
-}
-
-type RawSockaddrAny struct {
-	Addr RawSockaddr
-	Pad  [92]int8
-}
-
-type RawSockaddrCtl struct {
-	Sc_len      uint8
-	Sc_family   uint8
-	Ss_sysaddr  uint16
-	Sc_id       uint32
-	Sc_unit     uint32
-	Sc_reserved [5]uint32
-}
-
-type _Socklen uint32
-
-type Linger struct {
-	Onoff  int32
-	Linger int32
-}
-
-type Iovec struct {
-	Base *byte
-	Len  uint32
-}
-
-type IPMreq struct {
-	Multiaddr [4]byte /* in_addr */
-	Interface [4]byte /* in_addr */
-}
-
-type IPMreqn struct {
-	Multiaddr [4]byte /* in_addr */
-	Address   [4]byte /* in_addr */
-	Ifindex   int32
-}
-
-type IPv6Mreq struct {
-	Multiaddr [16]byte /* in6_addr */
-	Interface uint32
-}
-
-type Msghdr struct {
-	Name       *byte
-	Namelen    uint32
-	Iov        *Iovec
-	Iovlen     int32
-	Control    *byte
-	Controllen uint32
-	Flags      int32
-}
-
-type Cmsghdr struct {
-	Len   uint32
-	Level int32
-	Type  int32
-}
-
-type Inet4Pktinfo struct {
-	Ifindex  uint32
-	Spec_dst [4]byte /* in_addr */
-	Addr     [4]byte /* in_addr */
-}
-
-type Inet6Pktinfo struct {
-	Addr    [16]byte /* in6_addr */
-	Ifindex uint32
-}
-
-type IPv6MTUInfo struct {
-	Addr RawSockaddrInet6
-	Mtu  uint32
-}
-
-type ICMPv6Filter struct {
-	Filt [8]uint32
-}
-
-const (
-	SizeofSockaddrInet4    = 0x10
-	SizeofSockaddrInet6    = 0x1c
-	SizeofSockaddrAny      = 0x6c
-	SizeofSockaddrUnix     = 0x6a
-	SizeofSockaddrDatalink = 0x14
-	SizeofSockaddrCtl      = 0x20
-	SizeofLinger           = 0x8
-	SizeofIovec            = 0x8
-	SizeofIPMreq           = 0x8
-	SizeofIPMreqn          = 0xc
-	SizeofIPv6Mreq         = 0x14
-	SizeofMsghdr           = 0x1c
-	SizeofCmsghdr          = 0xc
-	SizeofInet4Pktinfo     = 0xc
-	SizeofInet6Pktinfo     = 0x14
-	SizeofIPv6MTUInfo      = 0x20
-	SizeofICMPv6Filter     = 0x20
-)
-
-const (
-	PTRACE_TRACEME = 0x0
-	PTRACE_CONT    = 0x7
-	PTRACE_KILL    = 0x8
-)
-
-type Kevent_t struct {
-	Ident  uint32
-	Filter int16
-	Flags  uint16
-	Fflags uint32
-	Data   int32
-	Udata  *byte
-}
-
-type FdSet struct {
-	Bits [32]int32
-}
-
-const (
-	SizeofIfMsghdr    = 0x70
-	SizeofIfData      = 0x60
-	SizeofIfaMsghdr   = 0x14
-	SizeofIfmaMsghdr  = 0x10
-	SizeofIfmaMsghdr2 = 0x14
-	SizeofRtMsghdr    = 0x5c
-	SizeofRtMetrics   = 0x38
-)
-
-type IfMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	Data    IfData
-}
-
-type IfData struct {
-	Type       uint8
-	Typelen    uint8
-	Physical   uint8
-	Addrlen    uint8
-	Hdrlen     uint8
-	Recvquota  uint8
-	Xmitquota  uint8
-	Unused1    uint8
-	Mtu        uint32
-	Metric     uint32
-	Baudrate   uint32
-	Ipackets   uint32
-	Ierrors    uint32
-	Opackets   uint32
-	Oerrors    uint32
-	Collisions uint32
-	Ibytes     uint32
-	Obytes     uint32
-	Imcasts    uint32
-	Omcasts    uint32
-	Iqdrops    uint32
-	Noproto    uint32
-	Recvtiming uint32
-	Xmittiming uint32
-	Lastchange Timeval
-	Unused2    uint32
-	Hwassist   uint32
-	Reserved1  uint32
-	Reserved2  uint32
-}
-
-type IfaMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	Metric  int32
-}
-
-type IfmaMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	_       [2]byte
-}
-
-type IfmaMsghdr2 struct {
-	Msglen   uint16
-	Version  uint8
-	Type     uint8
-	Addrs    int32
-	Flags    int32
-	Index    uint16
-	Refcount int32
-}
-
-type RtMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Index   uint16
-	Flags   int32
-	Addrs   int32
-	Pid     int32
-	Seq     int32
-	Errno   int32
-	Use     int32
-	Inits   uint32
-	Rmx     RtMetrics
-}
-
-type RtMetrics struct {
-	Locks    uint32
-	Mtu      uint32
-	Hopcount uint32
-	Expire   int32
-	Recvpipe uint32
-	Sendpipe uint32
-	Ssthresh uint32
-	Rtt      uint32
-	Rttvar   uint32
-	Pksent   uint32
-	State    uint32
-	Filler   [3]uint32
-}
-
-const (
-	SizeofBpfVersion = 0x4
-	SizeofBpfStat    = 0x8
-	SizeofBpfProgram = 0x8
-	SizeofBpfInsn    = 0x8
-	SizeofBpfHdr     = 0x14
-)
-
-type BpfVersion struct {
-	Major uint16
-	Minor uint16
-}
-
-type BpfStat struct {
-	Recv uint32
-	Drop uint32
-}
-
-type BpfProgram struct {
-	Len   uint32
-	Insns *BpfInsn
-}
-
-type BpfInsn struct {
-	Code uint16
-	Jt   uint8
-	Jf   uint8
-	K    uint32
-}
-
-type BpfHdr struct {
-	Tstamp  Timeval
-	Caplen  uint32
-	Datalen uint32
-	Hdrlen  uint16
-	_       [2]byte
-}
-
-type Termios struct {
-	Iflag  uint32
-	Oflag  uint32
-	Cflag  uint32
-	Lflag  uint32
-	Cc     [20]uint8
-	Ispeed uint32
-	Ospeed uint32
-}
-
-type Winsize struct {
-	Row    uint16
-	Col    uint16
-	Xpixel uint16
-	Ypixel uint16
-}
-
-const (
-	AT_FDCWD            = -0x2
-	AT_REMOVEDIR        = 0x80
-	AT_SYMLINK_FOLLOW   = 0x40
-	AT_SYMLINK_NOFOLLOW = 0x20
-)
-
-type PollFd struct {
-	Fd      int32
-	Events  int16
-	Revents int16
-}
-
-const (
-	POLLERR    = 0x8
-	POLLHUP    = 0x10
-	POLLIN     = 0x1
-	POLLNVAL   = 0x20
-	POLLOUT    = 0x4
-	POLLPRI    = 0x2
-	POLLRDBAND = 0x80
-	POLLRDNORM = 0x40
-	POLLWRBAND = 0x100
-	POLLWRNORM = 0x4
-)
-
-type Utsname struct {
-	Sysname  [256]byte
-	Nodename [256]byte
-	Release  [256]byte
-	Version  [256]byte
-	Machine  [256]byte
-}
-
-const SizeofClockinfo = 0x14
-
-type Clockinfo struct {
-	Hz      int32
-	Tick    int32
-	Tickadj int32
-	Stathz  int32
-	Profhz  int32
-}
-
-type CtlInfo struct {
-	Id   uint32
-	Name [96]byte
-}
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_arm.go b/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_arm.go
deleted file mode 100644
index eef51338574..00000000000
--- a/src/cmd/vendor/golang.org/x/sys/unix/ztypes_darwin_arm.go
+++ /dev/null
@@ -1,524 +0,0 @@
-// cgo -godefs types_darwin.go | go run mkpost.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-//go:build arm && darwin
-// +build arm,darwin
-
-package unix
-
-const (
-	SizeofPtr      = 0x4
-	SizeofShort    = 0x2
-	SizeofInt      = 0x4
-	SizeofLong     = 0x4
-	SizeofLongLong = 0x8
-)
-
-type (
-	_C_short     int16
-	_C_int       int32
-	_C_long      int32
-	_C_long_long int64
-)
-
-type Timespec struct {
-	Sec  int32
-	Nsec int32
-}
-
-type Timeval struct {
-	Sec  int32
-	Usec int32
-}
-
-type Timeval32 struct{}
-
-type Rusage struct {
-	Utime    Timeval
-	Stime    Timeval
-	Maxrss   int32
-	Ixrss    int32
-	Idrss    int32
-	Isrss    int32
-	Minflt   int32
-	Majflt   int32
-	Nswap    int32
-	Inblock  int32
-	Oublock  int32
-	Msgsnd   int32
-	Msgrcv   int32
-	Nsignals int32
-	Nvcsw    int32
-	Nivcsw   int32
-}
-
-type Rlimit struct {
-	Cur uint64
-	Max uint64
-}
-
-type _Gid_t uint32
-
-type Stat_t struct {
-	Dev     int32
-	Mode    uint16
-	Nlink   uint16
-	Ino     uint64
-	Uid     uint32
-	Gid     uint32
-	Rdev    int32
-	Atim    Timespec
-	Mtim    Timespec
-	Ctim    Timespec
-	Btim    Timespec
-	Size    int64
-	Blocks  int64
-	Blksize int32
-	Flags   uint32
-	Gen     uint32
-	Lspare  int32
-	Qspare  [2]int64
-}
-
-type Statfs_t struct {
-	Bsize       uint32
-	Iosize      int32
-	Blocks      uint64
-	Bfree       uint64
-	Bavail      uint64
-	Files       uint64
-	Ffree       uint64
-	Fsid        Fsid
-	Owner       uint32
-	Type        uint32
-	Flags       uint32
-	Fssubtype   uint32
-	Fstypename  [16]byte
-	Mntonname   [1024]byte
-	Mntfromname [1024]byte
-	Reserved    [8]uint32
-}
-
-type Flock_t struct {
-	Start  int64
-	Len    int64
-	Pid    int32
-	Type   int16
-	Whence int16
-}
-
-type Fstore_t struct {
-	Flags      uint32
-	Posmode    int32
-	Offset     int64
-	Length     int64
-	Bytesalloc int64
-}
-
-type Radvisory_t struct {
-	Offset int64
-	Count  int32
-}
-
-type Fbootstraptransfer_t struct {
-	Offset int64
-	Length uint32
-	Buffer *byte
-}
-
-type Log2phys_t struct {
-	Flags       uint32
-	Contigbytes int64
-	Devoffset   int64
-}
-
-type Fsid struct {
-	Val [2]int32
-}
-
-type Dirent struct {
-	Ino     uint64
-	Seekoff uint64
-	Reclen  uint16
-	Namlen  uint16
-	Type    uint8
-	Name    [1024]int8
-	_       [3]byte
-}
-
-const (
-	PathMax = 0x400
-)
-
-type RawSockaddrInet4 struct {
-	Len    uint8
-	Family uint8
-	Port   uint16
-	Addr   [4]byte /* in_addr */
-	Zero   [8]int8
-}
-
-type RawSockaddrInet6 struct {
-	Len      uint8
-	Family   uint8
-	Port     uint16
-	Flowinfo uint32
-	Addr     [16]byte /* in6_addr */
-	Scope_id uint32
-}
-
-type RawSockaddrUnix struct {
-	Len    uint8
-	Family uint8
-	Path   [104]int8
-}
-
-type RawSockaddrDatalink struct {
-	Len    uint8
-	Family uint8
-	Index  uint16
-	Type   uint8
-	Nlen   uint8
-	Alen   uint8
-	Slen   uint8
-	Data   [12]int8
-}
-
-type RawSockaddr struct {
-	Len    uint8
-	Family uint8
-	Data   [14]int8
-}
-
-type RawSockaddrAny struct {
-	Addr RawSockaddr
-	Pad  [92]int8
-}
-
-type RawSockaddrCtl struct {
-	Sc_len      uint8
-	Sc_family   uint8
-	Ss_sysaddr  uint16
-	Sc_id       uint32
-	Sc_unit     uint32
-	Sc_reserved [5]uint32
-}
-
-type _Socklen uint32
-
-type Linger struct {
-	Onoff  int32
-	Linger int32
-}
-
-type Iovec struct {
-	Base *byte
-	Len  uint32
-}
-
-type IPMreq struct {
-	Multiaddr [4]byte /* in_addr */
-	Interface [4]byte /* in_addr */
-}
-
-type IPMreqn struct {
-	Multiaddr [4]byte /* in_addr */
-	Address   [4]byte /* in_addr */
-	Ifindex   int32
-}
-
-type IPv6Mreq struct {
-	Multiaddr [16]byte /* in6_addr */
-	Interface uint32
-}
-
-type Msghdr struct {
-	Name       *byte
-	Namelen    uint32
-	Iov        *Iovec
-	Iovlen     int32
-	Control    *byte
-	Controllen uint32
-	Flags      int32
-}
-
-type Cmsghdr struct {
-	Len   uint32
-	Level int32
-	Type  int32
-}
-
-type Inet4Pktinfo struct {
-	Ifindex  uint32
-	Spec_dst [4]byte /* in_addr */
-	Addr     [4]byte /* in_addr */
-}
-
-type Inet6Pktinfo struct {
-	Addr    [16]byte /* in6_addr */
-	Ifindex uint32
-}
-
-type IPv6MTUInfo struct {
-	Addr RawSockaddrInet6
-	Mtu  uint32
-}
-
-type ICMPv6Filter struct {
-	Filt [8]uint32
-}
-
-const (
-	SizeofSockaddrInet4    = 0x10
-	SizeofSockaddrInet6    = 0x1c
-	SizeofSockaddrAny      = 0x6c
-	SizeofSockaddrUnix     = 0x6a
-	SizeofSockaddrDatalink = 0x14
-	SizeofSockaddrCtl      = 0x20
-	SizeofLinger           = 0x8
-	SizeofIovec            = 0x8
-	SizeofIPMreq           = 0x8
-	SizeofIPMreqn          = 0xc
-	SizeofIPv6Mreq         = 0x14
-	SizeofMsghdr           = 0x1c
-	SizeofCmsghdr          = 0xc
-	SizeofInet4Pktinfo     = 0xc
-	SizeofInet6Pktinfo     = 0x14
-	SizeofIPv6MTUInfo      = 0x20
-	SizeofICMPv6Filter     = 0x20
-)
-
-const (
-	PTRACE_TRACEME = 0x0
-	PTRACE_CONT    = 0x7
-	PTRACE_KILL    = 0x8
-)
-
-type Kevent_t struct {
-	Ident  uint32
-	Filter int16
-	Flags  uint16
-	Fflags uint32
-	Data   int32
-	Udata  *byte
-}
-
-type FdSet struct {
-	Bits [32]int32
-}
-
-const (
-	SizeofIfMsghdr    = 0x70
-	SizeofIfData      = 0x60
-	SizeofIfaMsghdr   = 0x14
-	SizeofIfmaMsghdr  = 0x10
-	SizeofIfmaMsghdr2 = 0x14
-	SizeofRtMsghdr    = 0x5c
-	SizeofRtMetrics   = 0x38
-)
-
-type IfMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	Data    IfData
-}
-
-type IfData struct {
-	Type       uint8
-	Typelen    uint8
-	Physical   uint8
-	Addrlen    uint8
-	Hdrlen     uint8
-	Recvquota  uint8
-	Xmitquota  uint8
-	Unused1    uint8
-	Mtu        uint32
-	Metric     uint32
-	Baudrate   uint32
-	Ipackets   uint32
-	Ierrors    uint32
-	Opackets   uint32
-	Oerrors    uint32
-	Collisions uint32
-	Ibytes     uint32
-	Obytes     uint32
-	Imcasts    uint32
-	Omcasts    uint32
-	Iqdrops    uint32
-	Noproto    uint32
-	Recvtiming uint32
-	Xmittiming uint32
-	Lastchange Timeval
-	Unused2    uint32
-	Hwassist   uint32
-	Reserved1  uint32
-	Reserved2  uint32
-}
-
-type IfaMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	Metric  int32
-}
-
-type IfmaMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Addrs   int32
-	Flags   int32
-	Index   uint16
-	_       [2]byte
-}
-
-type IfmaMsghdr2 struct {
-	Msglen   uint16
-	Version  uint8
-	Type     uint8
-	Addrs    int32
-	Flags    int32
-	Index    uint16
-	Refcount int32
-}
-
-type RtMsghdr struct {
-	Msglen  uint16
-	Version uint8
-	Type    uint8
-	Index   uint16
-	Flags   int32
-	Addrs   int32
-	Pid     int32
-	Seq     int32
-	Errno   int32
-	Use     int32
-	Inits   uint32
-	Rmx     RtMetrics
-}
-
-type RtMetrics struct {
-	Locks    uint32
-	Mtu      uint32
-	Hopcount uint32
-	Expire   int32
-	Recvpipe uint32
-	Sendpipe uint32
-	Ssthresh uint32
-	Rtt      uint32
-	Rttvar   uint32
-	Pksent   uint32
-	State    uint32
-	Filler   [3]uint32
-}
-
-const (
-	SizeofBpfVersion = 0x4
-	SizeofBpfStat    = 0x8
-	SizeofBpfProgram = 0x8
-	SizeofBpfInsn    = 0x8
-	SizeofBpfHdr     = 0x14
-)
-
-type BpfVersion struct {
-	Major uint16
-	Minor uint16
-}
-
-type BpfStat struct {
-	Recv uint32
-	Drop uint32
-}
-
-type BpfProgram struct {
-	Len   uint32
-	Insns *BpfInsn
-}
-
-type BpfInsn struct {
-	Code uint16
-	Jt   uint8
-	Jf   uint8
-	K    uint32
-}
-
-type BpfHdr struct {
-	Tstamp  Timeval
-	Caplen  uint32
-	Datalen uint32
-	Hdrlen  uint16
-	_       [2]byte
-}
-
-type Termios struct {
-	Iflag  uint32
-	Oflag  uint32
-	Cflag  uint32
-	Lflag  uint32
-	Cc     [20]uint8
-	Ispeed uint32
-	Ospeed uint32
-}
-
-type Winsize struct {
-	Row    uint16
-	Col    uint16
-	Xpixel uint16
-	Ypixel uint16
-}
-
-const (
-	AT_FDCWD            = -0x2
-	AT_REMOVEDIR        = 0x80
-	AT_SYMLINK_FOLLOW   = 0x40
-	AT_SYMLINK_NOFOLLOW = 0x20
-)
-
-type PollFd struct {
-	Fd      int32
-	Events  int16
-	Revents int16
-}
-
-const (
-	POLLERR    = 0x8
-	POLLHUP    = 0x10
-	POLLIN     = 0x1
-	POLLNVAL   = 0x20
-	POLLOUT    = 0x4
-	POLLPRI    = 0x2
-	POLLRDBAND = 0x80
-	POLLRDNORM = 0x40
-	POLLWRBAND = 0x100
-	POLLWRNORM = 0x4
-)
-
-type Utsname struct {
-	Sysname  [256]byte
-	Nodename [256]byte
-	Release  [256]byte
-	Version  [256]byte
-	Machine  [256]byte
-}
-
-const SizeofClockinfo = 0x14
-
-type Clockinfo struct {
-	Hz      int32
-	Tick    int32
-	Tickadj int32
-	Stathz  int32
-	Profhz  int32
-}
-
-type CtlInfo struct {
-	Id   uint32
-	Name [96]byte
-}
diff --git a/src/cmd/vendor/golang.org/x/sys/windows/empty.s b/src/cmd/vendor/golang.org/x/sys/windows/empty.s
index 69309e4da55..fdbbbcd3171 100644
--- a/src/cmd/vendor/golang.org/x/sys/windows/empty.s
+++ b/src/cmd/vendor/golang.org/x/sys/windows/empty.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !go1.12
 // +build !go1.12
 
 // This file is here to allow bodyless functions with go:linkname for Go 1.11
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
index eb0016b18f1..7b82d0b6ddb 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
@@ -51,6 +51,11 @@ type asmArch struct {
 	bigEndian bool
 	stack     string
 	lr        bool
+	// retRegs is a list of registers for return value in register ABI (ABIInternal).
+	// For now, as we only check whether we write to any result, here we only need to
+	// include the first integer register and first floating-point register. Accessing
+	// any of them counts as writing to result.
+	retRegs []string
 	// calculated during initialization
 	sizes    types.Sizes
 	intSize  int
@@ -79,8 +84,8 @@ type asmVar struct {
 var (
 	asmArch386      = asmArch{name: "386", bigEndian: false, stack: "SP", lr: false}
 	asmArchArm      = asmArch{name: "arm", bigEndian: false, stack: "R13", lr: true}
-	asmArchArm64    = asmArch{name: "arm64", bigEndian: false, stack: "RSP", lr: true}
-	asmArchAmd64    = asmArch{name: "amd64", bigEndian: false, stack: "SP", lr: false}
+	asmArchArm64    = asmArch{name: "arm64", bigEndian: false, stack: "RSP", lr: true, retRegs: []string{"R0", "F0"}}
+	asmArchAmd64    = asmArch{name: "amd64", bigEndian: false, stack: "SP", lr: false, retRegs: []string{"AX", "X0"}}
 	asmArchMips     = asmArch{name: "mips", bigEndian: true, stack: "R29", lr: true}
 	asmArchMipsLE   = asmArch{name: "mipsle", bigEndian: false, stack: "R29", lr: true}
 	asmArchMips64   = asmArch{name: "mips64", bigEndian: true, stack: "R29", lr: true}
@@ -137,7 +142,7 @@ var (
 	asmSP        = re(`[^+\-0-9](([0-9]+)\(([A-Z0-9]+)\))`)
 	asmOpcode    = re(`^\s*(?:[A-Z0-9a-z_]+:)?\s*([A-Z]+)\s*([^,]*)(?:,\s*(.*))?`)
 	ppc64Suff    = re(`([BHWD])(ZU|Z|U|BR)?$`)
-	abiSuff      = re(`^(.+)$`)
+	abiSuff      = re(`^(.+)<(ABI.+)>$`)
 )
 
 func run(pass *analysis.Pass) (interface{}, error) {
@@ -185,6 +190,7 @@ Files:
 		var (
 			fn                 *asmFunc
 			fnName             string
+			abi                string
 			localSize, argSize int
 			wroteSP            bool
 			noframe            bool
@@ -195,18 +201,22 @@ Files:
 		flushRet := func() {
 			if fn != nil && fn.vars["ret"] != nil && !haveRetArg && len(retLine) > 0 {
 				v := fn.vars["ret"]
+				resultStr := fmt.Sprintf("%d-byte ret+%d(FP)", v.size, v.off)
+				if abi == "ABIInternal" {
+					resultStr = "result register"
+				}
 				for _, line := range retLine {
-					pass.Reportf(analysisutil.LineStart(tf, line), "[%s] %s: RET without writing to %d-byte ret+%d(FP)", arch, fnName, v.size, v.off)
+					pass.Reportf(analysisutil.LineStart(tf, line), "[%s] %s: RET without writing to %s", arch, fnName, resultStr)
 				}
 			}
 			retLine = nil
 		}
-		trimABI := func(fnName string) string {
+		trimABI := func(fnName string) (string, string) {
 			m := abiSuff.FindStringSubmatch(fnName)
 			if m != nil {
-				return m[1]
+				return m[1], m[2]
 			}
-			return fnName
+			return fnName, ""
 		}
 		for lineno, line := range lines {
 			lineno++
@@ -273,11 +283,12 @@ Files:
 						// log.Printf("%s:%d: [%s] cannot check cross-package assembly function: %s is in package %s", fname, lineno, arch, fnName, pkgPath)
 						fn = nil
 						fnName = ""
+						abi = ""
 						continue
 					}
 				}
 				// Trim off optional ABI selector.
-				fnName := trimABI(fnName)
+				fnName, abi = trimABI(fnName)
 				flag := m[3]
 				fn = knownFunc[fnName][arch]
 				if fn != nil {
@@ -305,6 +316,7 @@ Files:
 				flushRet()
 				fn = nil
 				fnName = ""
+				abi = ""
 				continue
 			}
 
@@ -335,6 +347,15 @@ Files:
 				haveRetArg = true
 			}
 
+			if abi == "ABIInternal" && !haveRetArg {
+				for _, reg := range archDef.retRegs {
+					if strings.Contains(line, reg) {
+						haveRetArg = true
+						break
+					}
+				}
+			}
+
 			for _, m := range asmSP.FindAllStringSubmatch(line, -1) {
 				if m[3] != archDef.stack || wroteSP || noframe {
 					continue
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
index ddad4c796cb..6589478af0f 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
@@ -555,7 +555,7 @@ func checkPrintf(pass *analysis.Pass, kind Kind, call *ast.CallExpr, fn *types.F
 	format, idx := formatString(pass, call)
 	if idx < 0 {
 		if false {
-			pass.Reportf(call.Lparen, "can't check non-constant format in call to %s", fn.Name())
+			pass.Reportf(call.Lparen, "can't check non-constant format in call to %s", fn.FullName())
 		}
 		return
 	}
@@ -563,7 +563,7 @@ func checkPrintf(pass *analysis.Pass, kind Kind, call *ast.CallExpr, fn *types.F
 	firstArg := idx + 1 // Arguments are immediately after format string.
 	if !strings.Contains(format, "%") {
 		if len(call.Args) > firstArg {
-			pass.Reportf(call.Lparen, "%s call has arguments but no formatting directives", fn.Name())
+			pass.Reportf(call.Lparen, "%s call has arguments but no formatting directives", fn.FullName())
 		}
 		return
 	}
@@ -577,7 +577,7 @@ func checkPrintf(pass *analysis.Pass, kind Kind, call *ast.CallExpr, fn *types.F
 		if format[i] != '%' {
 			continue
 		}
-		state := parsePrintfVerb(pass, call, fn.Name(), format[i:], firstArg, argNum)
+		state := parsePrintfVerb(pass, call, fn.FullName(), format[i:], firstArg, argNum)
 		if state == nil {
 			return
 		}
@@ -589,8 +589,12 @@ func checkPrintf(pass *analysis.Pass, kind Kind, call *ast.CallExpr, fn *types.F
 			anyIndex = true
 		}
 		if state.verb == 'w' {
-			if kind != KindErrorf {
-				pass.Reportf(call.Pos(), "%s call has error-wrapping directive %%w", state.name)
+			switch kind {
+			case KindNone, KindPrint:
+				pass.Reportf(call.Pos(), "%s does not support error-wrapping directive %%w", state.name)
+				return
+			case KindPrintf:
+				pass.Reportf(call.Pos(), "%s call has error-wrapping directive %%w, which is only supported for functions backed by fmt.Errorf", state.name)
 				return
 			}
 			if anyW {
@@ -621,7 +625,7 @@ func checkPrintf(pass *analysis.Pass, kind Kind, call *ast.CallExpr, fn *types.F
 	if maxArgNum != len(call.Args) {
 		expect := maxArgNum - firstArg
 		numArgs := len(call.Args) - firstArg
-		pass.ReportRangef(call, "%s call needs %v but has %v", fn.Name(), count(expect, "arg"), count(numArgs, "arg"))
+		pass.ReportRangef(call, "%s call needs %v but has %v", fn.FullName(), count(expect, "arg"), count(numArgs, "arg"))
 	}
 }
 
@@ -949,7 +953,7 @@ func recursiveStringer(pass *analysis.Pass, e ast.Expr) (string, bool) {
 	}
 	if id, ok := e.(*ast.Ident); ok {
 		if pass.TypesInfo.Uses[id] == sig.Recv() {
-			return method.Name(), true
+			return method.FullName(), true
 		}
 	}
 	return "", false
@@ -1044,7 +1048,7 @@ func checkPrint(pass *analysis.Pass, call *ast.CallExpr, fn *types.Func) {
 		if sel, ok := call.Args[0].(*ast.SelectorExpr); ok {
 			if x, ok := sel.X.(*ast.Ident); ok {
 				if x.Name == "os" && strings.HasPrefix(sel.Sel.Name, "Std") {
-					pass.ReportRangef(call, "%s does not take io.Writer but has first arg %s", fn.Name(), analysisutil.Format(pass.Fset, call.Args[0]))
+					pass.ReportRangef(call, "%s does not take io.Writer but has first arg %s", fn.FullName(), analysisutil.Format(pass.Fset, call.Args[0]))
 				}
 			}
 		}
@@ -1058,7 +1062,7 @@ func checkPrint(pass *analysis.Pass, call *ast.CallExpr, fn *types.Func) {
 		if strings.Contains(s, "%") {
 			m := printFormatRE.FindStringSubmatch(s)
 			if m != nil {
-				pass.ReportRangef(call, "%s call has possible formatting directive %s", fn.Name(), m[0])
+				pass.ReportRangef(call, "%s call has possible formatting directive %s", fn.FullName(), m[0])
 			}
 		}
 	}
@@ -1068,16 +1072,16 @@ func checkPrint(pass *analysis.Pass, call *ast.CallExpr, fn *types.Func) {
 		if lit, ok := arg.(*ast.BasicLit); ok && lit.Kind == token.STRING {
 			str, _ := strconv.Unquote(lit.Value)
 			if strings.HasSuffix(str, "\n") {
-				pass.ReportRangef(call, "%s arg list ends with redundant newline", fn.Name())
+				pass.ReportRangef(call, "%s arg list ends with redundant newline", fn.FullName())
 			}
 		}
 	}
 	for _, arg := range args {
 		if isFunctionValue(pass, arg) {
-			pass.ReportRangef(call, "%s arg %s is a func value, not called", fn.Name(), analysisutil.Format(pass.Fset, arg))
+			pass.ReportRangef(call, "%s arg %s is a func value, not called", fn.FullName(), analysisutil.Format(pass.Fset, arg))
 		}
 		if methodName, ok := recursiveStringer(pass, arg); ok {
-			pass.ReportRangef(call, "%s arg %s causes recursive call to %s method", fn.Name(), analysisutil.Format(pass.Fset, arg), methodName)
+			pass.ReportRangef(call, "%s arg %s causes recursive call to %s method", fn.FullName(), analysisutil.Format(pass.Fset, arg), methodName)
 		}
 	}
 }
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/sigchanyzer/sigchanyzer.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/sigchanyzer/sigchanyzer.go
index b00aa7e1440..0d6c8ebf165 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/sigchanyzer/sigchanyzer.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/sigchanyzer/sigchanyzer.go
@@ -59,12 +59,19 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		if chanDecl == nil || len(chanDecl.Args) != 1 {
 			return
 		}
-		chanDecl.Args = append(chanDecl.Args, &ast.BasicLit{
+
+		// Make a copy of the channel's declaration to avoid
+		// mutating the AST. See https://golang.org/issue/46129.
+		chanDeclCopy := &ast.CallExpr{}
+		*chanDeclCopy = *chanDecl
+		chanDeclCopy.Args = append([]ast.Expr(nil), chanDecl.Args...)
+		chanDeclCopy.Args = append(chanDeclCopy.Args, &ast.BasicLit{
 			Kind:  token.INT,
 			Value: "1",
 		})
+
 		var buf bytes.Buffer
-		if err := format.Node(&buf, token.NewFileSet(), chanDecl); err != nil {
+		if err := format.Node(&buf, token.NewFileSet(), chanDeclCopy); err != nil {
 			return
 		}
 		pass.Report(analysis.Diagnostic{
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/stdmethods/stdmethods.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/stdmethods/stdmethods.go
index 856c6ae0d81..64a28ac0b97 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/stdmethods/stdmethods.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/stdmethods/stdmethods.go
@@ -61,10 +61,12 @@ var Analyzer = &analysis.Analyzer{
 // we let it go. But if it does have a fmt.ScanState, then the
 // rest has to match.
 var canonicalMethods = map[string]struct{ args, results []string }{
+	"As": {[]string{"interface{}"}, []string{"bool"}}, // errors.As
 	// "Flush": {{}, {"error"}}, // http.Flusher and jpeg.writer conflict
 	"Format":        {[]string{"=fmt.State", "rune"}, []string{}},                      // fmt.Formatter
 	"GobDecode":     {[]string{"[]byte"}, []string{"error"}},                           // gob.GobDecoder
 	"GobEncode":     {[]string{}, []string{"[]byte", "error"}},                         // gob.GobEncoder
+	"Is":            {[]string{"error"}, []string{"bool"}},                             // errors.Is
 	"MarshalJSON":   {[]string{}, []string{"[]byte", "error"}},                         // json.Marshaler
 	"MarshalXML":    {[]string{"*xml.Encoder", "xml.StartElement"}, []string{"error"}}, // xml.Marshaler
 	"ReadByte":      {[]string{}, []string{"byte", "error"}},                           // io.ByteReader
@@ -76,6 +78,7 @@ var canonicalMethods = map[string]struct{ args, results []string }{
 	"UnmarshalXML":  {[]string{"*xml.Decoder", "xml.StartElement"}, []string{"error"}}, // xml.Unmarshaler
 	"UnreadByte":    {[]string{}, []string{"error"}},
 	"UnreadRune":    {[]string{}, []string{"error"}},
+	"Unwrap":        {[]string{}, []string{"error"}},                      // errors.Unwrap
 	"WriteByte":     {[]string{"byte"}, []string{"error"}},                // jpeg.writer (matching bufio.Writer)
 	"WriteTo":       {[]string{"=io.Writer"}, []string{"int64", "error"}}, // io.WriterTo
 }
@@ -123,6 +126,14 @@ func canonicalMethod(pass *analysis.Pass, id *ast.Ident) {
 		return
 	}
 
+	// Special case: Is, As and Unwrap only apply when type
+	// implements error.
+	if id.Name == "Is" || id.Name == "As" || id.Name == "Unwrap" {
+		if recv := sign.Recv(); recv == nil || !implementsError(recv.Type()) {
+			return
+		}
+	}
+
 	// Do the =s (if any) all match?
 	if !matchParams(pass, expect.args, args, "=") || !matchParams(pass, expect.results, results, "=") {
 		return
@@ -185,3 +196,9 @@ func matchParamType(expect string, actual types.Type) bool {
 	// Overkill but easy.
 	return typeString(actual) == expect
 }
+
+var errorType = types.Universe.Lookup("error").Type().Underlying().(*types.Interface)
+
+func implementsError(actual types.Type) bool {
+	return types.Implements(actual, errorType)
+}
diff --git a/src/cmd/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go b/src/cmd/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go
index cf72ea990bd..5fe75b14c75 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go
@@ -9,6 +9,8 @@ import (
 	"go/ast"
 	"reflect"
 	"sort"
+
+	"golang.org/x/tools/internal/typeparams"
 )
 
 // An ApplyFunc is invoked by Apply for each node n, even if n is nil,
@@ -437,7 +439,13 @@ func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.
 		}
 
 	default:
-		panic(fmt.Sprintf("Apply: unexpected node type %T", n))
+		if ix := typeparams.GetIndexExprData(n); ix != nil {
+			a.apply(n, "X", nil, ix.X)
+			// *ast.IndexExpr was handled above, so n must be an *ast.MultiIndexExpr.
+			a.applyList(n, "Indices")
+		} else {
+			panic(fmt.Sprintf("Apply: unexpected node type %T", n))
+		}
 	}
 
 	if a.post != nil && !a.post(&a.cursor) {
diff --git a/src/cmd/vendor/golang.org/x/tools/go/types/objectpath/objectpath.go b/src/cmd/vendor/golang.org/x/tools/go/types/objectpath/objectpath.go
index cffd7acbee7..81e8fdcf0c1 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/types/objectpath/objectpath.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/types/objectpath/objectpath.go
@@ -58,7 +58,7 @@ type Path string
 // - The only OT operator is Object.Type,
 //   which we encode as '.' because dot cannot appear in an identifier.
 // - The TT operators are encoded as [EKPRU].
-// - The OT operators are encoded as [AFMO];
+// - The TO operators are encoded as [AFMO];
 //   three of these (At,Field,Method) require an integer operand,
 //   which is encoded as a string of decimal digits.
 //   These indices are stable across different representations
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/input.go b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/input.go
index ac377035ec6..c1038163f1a 100644
--- a/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/input.go
+++ b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/input.go
@@ -27,23 +27,23 @@ const (
 // RuneRoles detects the roles of each byte rune in an input string and stores it in the output
 // slice. The rune role depends on the input type. Stops when it parsed all the runes in the string
 // or when it filled the output. If output is nil, then it gets created.
-func RuneRoles(str string, reuse []RuneRole) []RuneRole {
+func RuneRoles(candidate []byte, reuse []RuneRole) []RuneRole {
 	var output []RuneRole
-	if cap(reuse) < len(str) {
-		output = make([]RuneRole, 0, len(str))
+	if cap(reuse) < len(candidate) {
+		output = make([]RuneRole, 0, len(candidate))
 	} else {
 		output = reuse[:0]
 	}
 
 	prev, prev2 := rtNone, rtNone
-	for i := 0; i < len(str); i++ {
-		r := rune(str[i])
+	for i := 0; i < len(candidate); i++ {
+		r := rune(candidate[i])
 
 		role := RNone
 
 		curr := rtLower
-		if str[i] <= unicode.MaxASCII {
-			curr = runeType(rt[str[i]] - '0')
+		if candidate[i] <= unicode.MaxASCII {
+			curr = runeType(rt[candidate[i]] - '0')
 		}
 
 		if curr == rtLower {
@@ -58,7 +58,7 @@ func RuneRoles(str string, reuse []RuneRole) []RuneRole {
 			if prev == rtUpper {
 				// This and previous characters are both upper case.
 
-				if i+1 == len(str) {
+				if i+1 == len(candidate) {
 					// This is last character, previous was also uppercase -> this is UCTail
 					// i.e., (current char is C): aBC / BC / ABC
 					role = RUCTail
@@ -118,11 +118,26 @@ func LastSegment(input string, roles []RuneRole) string {
 	return input[start+1 : end+1]
 }
 
-// ToLower transforms the input string to lower case, which is stored in the output byte slice.
+// fromChunks copies string chunks into the given buffer.
+func fromChunks(chunks []string, buffer []byte) []byte {
+	ii := 0
+	for _, chunk := range chunks {
+		for i := 0; i < len(chunk); i++ {
+			if ii >= cap(buffer) {
+				break
+			}
+			buffer[ii] = chunk[i]
+			ii++
+		}
+	}
+	return buffer[:ii]
+}
+
+// toLower transforms the input string to lower case, which is stored in the output byte slice.
 // The lower casing considers only ASCII values - non ASCII values are left unmodified.
 // Stops when parsed all input or when it filled the output slice. If output is nil, then it gets
 // created.
-func ToLower(input string, reuse []byte) []byte {
+func toLower(input []byte, reuse []byte) []byte {
 	output := reuse
 	if cap(reuse) < len(input) {
 		output = make([]byte, len(input))
@@ -130,7 +145,7 @@ func ToLower(input string, reuse []byte) []byte {
 
 	for i := 0; i < len(input); i++ {
 		r := rune(input[i])
-		if r <= unicode.MaxASCII {
+		if input[i] <= unicode.MaxASCII {
 			if 'A' <= r && r <= 'Z' {
 				r += 'a' - 'A'
 			}
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/matcher.go b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/matcher.go
index 16a643097de..265cdcf1604 100644
--- a/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/matcher.go
+++ b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/matcher.go
@@ -51,8 +51,12 @@ type Matcher struct {
 	lastCandidateLen     int // in bytes
 	lastCandidateMatched bool
 
-	// Here we save the last candidate in lower-case. This is basically a byte slice we reuse for
-	// performance reasons, so the slice is not reallocated for every candidate.
+	// Reusable buffers to avoid allocating for every candidate.
+	//  - inputBuf stores the concatenated input chunks
+	//  - lowerBuf stores the last candidate in lower-case
+	//  - rolesBuf stores the calculated roles for each rune in the last
+	//    candidate.
+	inputBuf [MaxInputSize]byte
 	lowerBuf [MaxInputSize]byte
 	rolesBuf [MaxInputSize]RuneRole
 }
@@ -72,7 +76,7 @@ func NewMatcher(pattern string) *Matcher {
 
 	m := &Matcher{
 		pattern:      pattern,
-		patternLower: ToLower(pattern, nil),
+		patternLower: toLower([]byte(pattern), nil),
 	}
 
 	for i, c := range m.patternLower {
@@ -88,7 +92,7 @@ func NewMatcher(pattern string) *Matcher {
 		m.patternShort = m.patternLower
 	}
 
-	m.patternRoles = RuneRoles(pattern, nil)
+	m.patternRoles = RuneRoles([]byte(pattern), nil)
 
 	if len(pattern) > 0 {
 		maxCharScore := 4
@@ -102,10 +106,15 @@ func NewMatcher(pattern string) *Matcher {
 // This is not designed for parallel use. Multiple candidates must be scored sequentially.
 // Returns a score between 0 and 1 (0 - no match, 1 - perfect match).
 func (m *Matcher) Score(candidate string) float32 {
+	return m.ScoreChunks([]string{candidate})
+}
+
+func (m *Matcher) ScoreChunks(chunks []string) float32 {
+	candidate := fromChunks(chunks, m.inputBuf[:])
 	if len(candidate) > MaxInputSize {
 		candidate = candidate[:MaxInputSize]
 	}
-	lower := ToLower(candidate, m.lowerBuf[:])
+	lower := toLower(candidate, m.lowerBuf[:])
 	m.lastCandidateLen = len(candidate)
 
 	if len(m.pattern) == 0 {
@@ -174,7 +183,7 @@ func (m *Matcher) MatchedRanges() []int {
 	return ret
 }
 
-func (m *Matcher) match(candidate string, candidateLower []byte) bool {
+func (m *Matcher) match(candidate []byte, candidateLower []byte) bool {
 	i, j := 0, 0
 	for ; i < len(candidateLower) && j < len(m.patternLower); i++ {
 		if candidateLower[i] == m.patternLower[j] {
@@ -192,7 +201,7 @@ func (m *Matcher) match(candidate string, candidateLower []byte) bool {
 	return true
 }
 
-func (m *Matcher) computeScore(candidate string, candidateLower []byte) int {
+func (m *Matcher) computeScore(candidate []byte, candidateLower []byte) int {
 	pattLen, candLen := len(m.pattern), len(candidate)
 
 	for j := 0; j <= len(m.pattern); j++ {
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/symbol.go b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/symbol.go
new file mode 100644
index 00000000000..062f491fb5c
--- /dev/null
+++ b/src/cmd/vendor/golang.org/x/tools/internal/lsp/fuzzy/symbol.go
@@ -0,0 +1,224 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzzy
+
+import (
+	"unicode"
+)
+
+// SymbolMatcher implements a fuzzy matching algorithm optimized for Go symbols
+// of the form:
+//  example.com/path/to/package.object.field
+//
+// Knowing that we are matching symbols like this allows us to make the
+// following optimizations:
+//  - We can incorporate right-to-left relevance directly into the score
+//    calculation.
+//  - We can match from right to left, discarding leading bytes if the input is
+//    too long.
+//  - We just take the right-most match without losing too much precision. This
+//    allows us to use an O(n) algorithm.
+//  - We can operate directly on chunked strings; in many cases we will
+//    be storing the package path and/or package name separately from the
+//    symbol or identifiers, so doing this avoids allocating strings.
+//  - We can return the index of the right-most match, allowing us to trim
+//    irrelevant qualification.
+//
+// This implementation is experimental, serving as a reference fast algorithm
+// to compare to the fuzzy algorithm implemented by Matcher.
+type SymbolMatcher struct {
+	// Using buffers of length 256 is both a reasonable size for most qualified
+	// symbols, and makes it easy to avoid bounds checks by using uint8 indexes.
+	pattern     [256]rune
+	patternLen  uint8
+	inputBuffer [256]rune   // avoid allocating when considering chunks
+	roles       [256]uint32 // which roles does a rune play (word start, etc.)
+	segments    [256]uint8  // how many segments from the right is each rune
+}
+
+const (
+	segmentStart uint32 = 1 << iota
+	wordStart
+	separator
+)
+
+// NewSymbolMatcher creates a SymbolMatcher that may be used to match the given
+// search pattern.
+//
+// Currently this matcher only accepts case-insensitive fuzzy patterns.
+//
+// TODO(rfindley):
+//  - implement smart-casing
+//  - implement space-separated groups
+//  - implement ', ^, and $ modifiers
+//
+// An empty pattern matches no input.
+func NewSymbolMatcher(pattern string) *SymbolMatcher {
+	m := &SymbolMatcher{}
+	for _, p := range pattern {
+		m.pattern[m.patternLen] = unicode.ToLower(p)
+		m.patternLen++
+		if m.patternLen == 255 || int(m.patternLen) == len(pattern) {
+			// break at 255 so that we can represent patternLen with a uint8.
+			break
+		}
+	}
+	return m
+}
+
+// Match looks for the right-most match of the search pattern within the symbol
+// represented by concatenating the given chunks, returning its offset and
+// score.
+//
+// If a match is found, the first return value will hold the absolute byte
+// offset within all chunks for the start of the symbol. In other words, the
+// index of the match within strings.Join(chunks, ""). If no match is found,
+// the first return value will be -1.
+//
+// The second return value will be the score of the match, which is always
+// between 0 and 1, inclusive. A score of 0 indicates no match.
+func (m *SymbolMatcher) Match(chunks []string) (int, float64) {
+	// Explicit behavior for an empty pattern.
+	//
+	// As a minor optimization, this also avoids nilness checks later on, since
+	// the compiler can prove that m != nil.
+	if m.patternLen == 0 {
+		return -1, 0
+	}
+
+	// First phase: populate the input buffer with lower-cased runes.
+	//
+	// We could also check for a forward match here, but since we'd have to write
+	// the entire input anyway this has negligible impact on performance.
+
+	var (
+		inputLen  = uint8(0)
+		modifiers = wordStart | segmentStart
+	)
+
+input:
+	for _, chunk := range chunks {
+		for _, r := range chunk {
+			if r == '.' || r == '/' {
+				modifiers |= separator
+			}
+			// optimization: avoid calls to unicode.ToLower, which can't be inlined.
+			l := r
+			if r <= unicode.MaxASCII {
+				if 'A' <= r && r <= 'Z' {
+					l = r + 'a' - 'A'
+				}
+			} else {
+				l = unicode.ToLower(r)
+			}
+			if l != r {
+				modifiers |= wordStart
+			}
+			m.inputBuffer[inputLen] = l
+			m.roles[inputLen] = modifiers
+			inputLen++
+			if m.roles[inputLen-1]&separator != 0 {
+				modifiers = wordStart | segmentStart
+			} else {
+				modifiers = 0
+			}
+			// TODO: we should prefer the right-most input if it overflows, rather
+			//       than the left-most as we're doing here.
+			if inputLen == 255 {
+				break input
+			}
+		}
+	}
+
+	// Second phase: find the right-most match, and count segments from the
+	// right.
+
+	var (
+		pi    = uint8(m.patternLen - 1) // pattern index
+		p     = m.pattern[pi]           // pattern rune
+		start = -1                      // start offset of match
+		rseg  = uint8(0)
+	)
+	const maxSeg = 3 // maximum number of segments from the right to count, for scoring purposes.
+
+	for ii := inputLen - 1; ; ii-- {
+		r := m.inputBuffer[ii]
+		if rseg < maxSeg && m.roles[ii]&separator != 0 {
+			rseg++
+		}
+		m.segments[ii] = rseg
+		if p == r {
+			if pi == 0 {
+				start = int(ii)
+				break
+			}
+			pi--
+			p = m.pattern[pi]
+		}
+		// Don't check ii >= 0 in the loop condition: ii is a uint8.
+		if ii == 0 {
+			break
+		}
+	}
+
+	if start < 0 {
+		// no match: skip scoring
+		return -1, 0
+	}
+
+	// Third phase: find the shortest match, and compute the score.
+
+	// Score is the average score for each character.
+	//
+	// A character score is the multiple of:
+	//   1. 1.0 if the character starts a segment, .8 if the character start a
+	//      mid-segment word, otherwise 0.6. This carries over to immediately
+	//      following characters.
+	//   2. 1.0 if the character is part of the last segment, otherwise
+	//      1.0-.2*, with a max segment count of 3.
+	//
+	// This is a very naive algorithm, but it is fast. There's lots of prior art
+	// here, and we should leverage it. For example, we could explicitly consider
+	// character distance, and exact matches of words or segments.
+	//
+	// Also note that this might not actually find the highest scoring match, as
+	// doing so could require a non-linear algorithm, depending on how the score
+	// is calculated.
+
+	pi = 0
+	p = m.pattern[pi]
+
+	const (
+		segStreak  = 1.0
+		wordStreak = 0.8
+		noStreak   = 0.6
+		perSegment = 0.2 // we count at most 3 segments above
+	)
+
+	streakBonus := noStreak
+	totScore := 0.0
+	for ii := uint8(start); ii < inputLen; ii++ {
+		r := m.inputBuffer[ii]
+		if r == p {
+			pi++
+			p = m.pattern[pi]
+			// Note: this could be optimized with some bit operations.
+			switch {
+			case m.roles[ii]&segmentStart != 0 && segStreak > streakBonus:
+				streakBonus = segStreak
+			case m.roles[ii]&wordStart != 0 && wordStreak > streakBonus:
+				streakBonus = wordStreak
+			}
+			totScore += streakBonus * (1.0 - float64(m.segments[ii])*perSegment)
+			if pi >= m.patternLen {
+				break
+			}
+		} else {
+			streakBonus = noStreak
+		}
+	}
+
+	return start, totScore / float64(m.patternLen)
+}
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/typeparams/common.go b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/common.go
new file mode 100644
index 00000000000..9fc6b4beb88
--- /dev/null
+++ b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/common.go
@@ -0,0 +1,25 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package typeparams provides functions to work indirectly with type parameter
+// data stored in go/ast and go/types objects, while these API are guarded by a
+// build constraint.
+//
+// This package exists to make it easier for tools to work with generic code,
+// while also compiling against older Go versions.
+package typeparams
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+// A IndexExprData holds data from both ast.IndexExpr and the new
+// ast.MultiIndexExpr, which was introduced in Go 1.18.
+type IndexExprData struct {
+	X       ast.Expr   // expression
+	Lbrack  token.Pos  // position of "["
+	Indices []ast.Expr // index expressions
+	Rbrack  token.Pos  // position of "]"
+}
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/typeparams/notypeparams.go b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/notypeparams.go
new file mode 100644
index 00000000000..e975e476f66
--- /dev/null
+++ b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/notypeparams.go
@@ -0,0 +1,93 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !typeparams || !go1.18
+// +build !typeparams !go1.18
+
+package typeparams
+
+import (
+	"go/ast"
+	"go/types"
+)
+
+// NOTE: doc comments must be kept in sync with typeparams.go.
+
+// Enabled reports whether type parameters are enabled in the current build
+// environment.
+const Enabled = false
+
+// GetIndexExprData extracts data from AST nodes that represent index
+// expressions.
+//
+// For an ast.IndexExpr, the resulting IndexExprData will have exactly one
+// index expression. For an ast.MultiIndexExpr (go1.18+), it may have a
+// variable number of index expressions.
+//
+// For nodes that don't represent index expressions, GetIndexExprData returns
+// nil.
+func GetIndexExprData(n ast.Node) *IndexExprData {
+	if e, _ := n.(*ast.IndexExpr); e != nil {
+		return &IndexExprData{
+			X:       e.X,
+			Lbrack:  e.Lbrack,
+			Indices: []ast.Expr{e.Index},
+			Rbrack:  e.Rbrack,
+		}
+	}
+	return nil
+}
+
+// ForTypeDecl extracts the (possibly nil) type parameter node list from n.
+func ForTypeDecl(*ast.TypeSpec) *ast.FieldList {
+	return nil
+}
+
+// ForFuncDecl extracts the (possibly nil) type parameter node list from n.
+func ForFuncDecl(*ast.FuncDecl) *ast.FieldList {
+	return nil
+}
+
+// ForSignature extracts the (possibly empty) type parameter object list from
+// sig.
+func ForSignature(*types.Signature) []*types.TypeName {
+	return nil
+}
+
+// IsComparable reports if iface is the comparable interface.
+func IsComparable(*types.Interface) bool {
+	return false
+}
+
+// IsConstraint reports whether iface may only be used as a type parameter
+// constraint (i.e. has a type set or is the comparable interface).
+func IsConstraint(*types.Interface) bool {
+	return false
+}
+
+// ForNamed extracts the (possibly empty) type parameter object list from
+// named.
+func ForNamed(*types.Named) []*types.TypeName {
+	return nil
+}
+
+// NamedTArgs extracts the (possibly empty) type argument list from named.
+func NamedTArgs(*types.Named) []types.Type {
+	return nil
+}
+
+// InitInferred initializes info to record inferred type information.
+func InitInferred(*types.Info) {
+}
+
+// GetInferred extracts inferred type information from info for e.
+//
+// The expression e may have an inferred type if it is an *ast.IndexExpr
+// representing partial instantiation of a generic function type for which type
+// arguments have been inferred using constraint type inference, or if it is an
+// *ast.CallExpr for which type type arguments have be inferred using both
+// constraint type inference and function argument inference.
+func GetInferred(*types.Info, ast.Expr) ([]types.Type, *types.Signature) {
+	return nil, nil
+}
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/typeparams/typeparams.go b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/typeparams.go
new file mode 100644
index 00000000000..be6b0525f61
--- /dev/null
+++ b/src/cmd/vendor/golang.org/x/tools/internal/typeparams/typeparams.go
@@ -0,0 +1,115 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build typeparams && go1.18
+// +build typeparams,go1.18
+
+package typeparams
+
+import (
+	"go/ast"
+	"go/types"
+)
+
+// NOTE: doc comments must be kept in sync with notypeparams.go.
+
+// Enabled reports whether type parameters are enabled in the current build
+// environment.
+const Enabled = true
+
+// GetIndexExprData extracts data from AST nodes that represent index
+// expressions.
+//
+// For an ast.IndexExpr, the resulting IndexExprData will have exactly one
+// index expression. For an ast.MultiIndexExpr (go1.18+), it may have a
+// variable number of index expressions.
+//
+// For nodes that don't represent index expressions, GetIndexExprData returns
+// nil.
+func GetIndexExprData(n ast.Node) *IndexExprData {
+	switch e := n.(type) {
+	case *ast.IndexExpr:
+		return &IndexExprData{
+			X:       e.X,
+			Lbrack:  e.Lbrack,
+			Indices: []ast.Expr{e.Index},
+			Rbrack:  e.Rbrack,
+		}
+	case *ast.MultiIndexExpr:
+		return (*IndexExprData)(e)
+	}
+	return nil
+}
+
+// ForTypeDecl extracts the (possibly nil) type parameter node list from n.
+func ForTypeDecl(n *ast.TypeSpec) *ast.FieldList {
+	return n.TParams
+}
+
+// ForFuncDecl extracts the (possibly nil) type parameter node list from n.
+func ForFuncDecl(n *ast.FuncDecl) *ast.FieldList {
+	if n.Type != nil {
+		return n.Type.TParams
+	}
+	return nil
+}
+
+// ForSignature extracts the (possibly empty) type parameter object list from
+// sig.
+func ForSignature(sig *types.Signature) []*types.TypeName {
+	return tparamsSlice(sig.TParams())
+}
+
+// IsComparable reports if iface is the comparable interface.
+func IsComparable(iface *types.Interface) bool {
+	return iface.IsComparable()
+}
+
+// IsConstraint reports whether iface may only be used as a type parameter
+// constraint (i.e. has a type set or is the comparable interface).
+func IsConstraint(iface *types.Interface) bool {
+	return iface.IsConstraint()
+}
+
+// ForNamed extracts the (possibly empty) type parameter object list from
+// named.
+func ForNamed(named *types.Named) []*types.TypeName {
+	return tparamsSlice(named.TParams())
+}
+
+func tparamsSlice(tparams *types.TypeParams) []*types.TypeName {
+	if tparams.Len() == 0 {
+		return nil
+	}
+	result := make([]*types.TypeName, tparams.Len())
+	for i := 0; i < tparams.Len(); i++ {
+		result[i] = tparams.At(i)
+	}
+	return result
+}
+
+// NamedTArgs extracts the (possibly empty) type argument list from named.
+func NamedTArgs(named *types.Named) []types.Type {
+	return named.TArgs()
+}
+
+// InitInferred initializes info to record inferred type information.
+func InitInferred(info *types.Info) {
+	info.Inferred = make(map[ast.Expr]types.Inferred)
+}
+
+// GetInferred extracts inferred type information from info for e.
+//
+// The expression e may have an inferred type if it is an *ast.IndexExpr
+// representing partial instantiation of a generic function type for which type
+// arguments have been inferred using constraint type inference, or if it is an
+// *ast.CallExpr for which type type arguments have be inferred using both
+// constraint type inference and function argument inference.
+func GetInferred(info *types.Info, e ast.Expr) ([]types.Type, *types.Signature) {
+	if info.Inferred == nil {
+		return nil, nil
+	}
+	inf := info.Inferred[e]
+	return inf.TArgs, inf.Sig
+}
diff --git a/src/cmd/vendor/modules.txt b/src/cmd/vendor/modules.txt
index 6b19ec3aea1..c98bdcd3440 100644
--- a/src/cmd/vendor/modules.txt
+++ b/src/cmd/vendor/modules.txt
@@ -1,4 +1,4 @@
-# github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5
+# github.com/google/pprof v0.0.0-20210506205249-923b5ab0fc1a
 ## explicit; go 1.14
 github.com/google/pprof/driver
 github.com/google/pprof/internal/binutils
@@ -28,7 +28,7 @@ golang.org/x/arch/x86/x86asm
 ## explicit; go 1.17
 golang.org/x/crypto/ed25519
 golang.org/x/crypto/ed25519/internal/edwards25519
-# golang.org/x/mod v0.4.3-0.20210504181020-67f1c1edc27a
+# golang.org/x/mod v0.4.3-0.20210608190319-0f08993efd8a
 ## explicit; go 1.17
 golang.org/x/mod/internal/lazyregexp
 golang.org/x/mod/modfile
@@ -39,7 +39,7 @@ golang.org/x/mod/sumdb/dirhash
 golang.org/x/mod/sumdb/note
 golang.org/x/mod/sumdb/tlog
 golang.org/x/mod/zip
-# golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6
+# golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744
 ## explicit; go 1.17
 golang.org/x/sys/internal/unsafeheader
 golang.org/x/sys/plan9
@@ -48,7 +48,7 @@ golang.org/x/sys/windows
 # golang.org/x/term v0.0.0-20210503060354-a79de5458b56
 ## explicit; go 1.17
 golang.org/x/term
-# golang.org/x/tools v0.1.1-0.20210505014545-7cab0ef2e9a5
+# golang.org/x/tools v0.1.6-0.20210809225032-337cebd2c151
 ## explicit; go 1.17
 golang.org/x/tools/cover
 golang.org/x/tools/go/analysis
@@ -92,6 +92,7 @@ golang.org/x/tools/go/types/objectpath
 golang.org/x/tools/go/types/typeutil
 golang.org/x/tools/internal/analysisinternal
 golang.org/x/tools/internal/lsp/fuzzy
+golang.org/x/tools/internal/typeparams
 # golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
 ## explicit; go 1.11
 golang.org/x/xerrors
diff --git a/src/cmd/vet/main.go b/src/cmd/vet/main.go
index a33bba24666..7da8606eceb 100644
--- a/src/cmd/vet/main.go
+++ b/src/cmd/vet/main.go
@@ -1,3 +1,7 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package main
 
 import (
diff --git a/src/cmd/vet/testdata/copylock/copylock.go b/src/cmd/vet/testdata/copylock/copylock.go
index 8079cf3248b..7cfafe64086 100644
--- a/src/cmd/vet/testdata/copylock/copylock.go
+++ b/src/cmd/vet/testdata/copylock/copylock.go
@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package copylock
 
 import "sync"
diff --git a/src/cmd/vet/testdata/httpresponse/httpresponse.go b/src/cmd/vet/testdata/httpresponse/httpresponse.go
index 6141f6e06dc..98e394a2715 100644
--- a/src/cmd/vet/testdata/httpresponse/httpresponse.go
+++ b/src/cmd/vet/testdata/httpresponse/httpresponse.go
@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package httpresponse
 
 import (
diff --git a/src/cmd/vet/testdata/print/print.go b/src/cmd/vet/testdata/print/print.go
index fca594925f7..46240e87bfd 100644
--- a/src/cmd/vet/testdata/print/print.go
+++ b/src/cmd/vet/testdata/print/print.go
@@ -491,10 +491,10 @@ type recursiveStringer int
 func (s recursiveStringer) String() string {
 	_ = fmt.Sprintf("%d", s)
 	_ = fmt.Sprintf("%#v", s)
-	_ = fmt.Sprintf("%v", s)  // ERROR "Sprintf format %v with arg s causes recursive String method call"
-	_ = fmt.Sprintf("%v", &s) // ERROR "Sprintf format %v with arg &s causes recursive String method call"
+	_ = fmt.Sprintf("%v", s)  // ERROR "Sprintf format %v with arg s causes recursive .*String method call"
+	_ = fmt.Sprintf("%v", &s) // ERROR "Sprintf format %v with arg &s causes recursive .*String method call"
 	_ = fmt.Sprintf("%T", s)  // ok; does not recursively call String
-	return fmt.Sprintln(s)    // ERROR "Sprintln arg s causes recursive call to String method"
+	return fmt.Sprintln(s)    // ERROR "Sprintln arg s causes recursive call to .*String method"
 }
 
 type recursivePtrStringer int
@@ -502,7 +502,7 @@ type recursivePtrStringer int
 func (p *recursivePtrStringer) String() string {
 	_ = fmt.Sprintf("%v", *p)
 	_ = fmt.Sprint(&p)     // ok; prints address
-	return fmt.Sprintln(p) // ERROR "Sprintln arg p causes recursive call to String method"
+	return fmt.Sprintln(p) // ERROR "Sprintln arg p causes recursive call to .*String method"
 }
 
 type BoolFormatter bool
diff --git a/src/cmd/vet/testdata/testingpkg/tests.go b/src/cmd/vet/testdata/testingpkg/tests.go
index 69d29d3c6c6..8f4674d33c0 100644
--- a/src/cmd/vet/testdata/testingpkg/tests.go
+++ b/src/cmd/vet/testdata/testingpkg/tests.go
@@ -1 +1,5 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package testdata
diff --git a/src/cmd/vet/testdata/testingpkg/tests_test.go b/src/cmd/vet/testdata/testingpkg/tests_test.go
index 09bb98d980e..815dcc8a95f 100644
--- a/src/cmd/vet/testdata/testingpkg/tests_test.go
+++ b/src/cmd/vet/testdata/testingpkg/tests_test.go
@@ -1,3 +1,7 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package testdata
 
 func Example_BadSuffix() {} // ERROR "Example_BadSuffix has malformed example suffix: BadSuffix"
diff --git a/src/crypto/cipher/xor_ppc64x.s b/src/crypto/cipher/xor_ppc64x.s
index 4cef31d0ee3..2ba6d9639c4 100644
--- a/src/crypto/cipher/xor_ppc64x.s
+++ b/src/crypto/cipher/xor_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/crypto/ed25519/internal/edwards25519/field/fe_amd64.go b/src/crypto/ed25519/internal/edwards25519/field/fe_amd64.go
index 44dc8e8caf9..8fe583939f1 100644
--- a/src/crypto/ed25519/internal/edwards25519/field/fe_amd64.go
+++ b/src/crypto/ed25519/internal/edwards25519/field/fe_amd64.go
@@ -1,5 +1,6 @@
 // Code generated by command: go run fe_amd64_asm.go -out ../fe_amd64.s -stubs ../fe_amd64.go -pkg field. DO NOT EDIT.
 
+//go:build amd64 && gc && !purego
 // +build amd64,gc,!purego
 
 package field
diff --git a/src/crypto/elliptic/elliptic.go b/src/crypto/elliptic/elliptic.go
index f93dc16419f..f072960bfed 100644
--- a/src/crypto/elliptic/elliptic.go
+++ b/src/crypto/elliptic/elliptic.go
@@ -40,6 +40,15 @@ type Curve interface {
 	ScalarBaseMult(k []byte) (x, y *big.Int)
 }
 
+func matchesSpecificCurve(params *CurveParams, available ...Curve) (Curve, bool) {
+	for _, c := range available {
+		if params == c.Params() {
+			return c, true
+		}
+	}
+	return nil, false
+}
+
 // CurveParams contains the parameters of an elliptic curve and also provides
 // a generic, non-constant time implementation of Curve.
 type CurveParams struct {
@@ -71,6 +80,12 @@ func (curve *CurveParams) polynomial(x *big.Int) *big.Int {
 }
 
 func (curve *CurveParams) IsOnCurve(x, y *big.Int) bool {
+	// If there is a dedicated constant-time implementation for this curve operation,
+	// use that instead of the generic one.
+	if specific, ok := matchesSpecificCurve(curve, p224, p521); ok {
+		return specific.IsOnCurve(x, y)
+	}
+
 	// y² = x³ - 3x + b
 	y2 := new(big.Int).Mul(y, y)
 	y2.Mod(y2, curve.P)
@@ -108,6 +123,12 @@ func (curve *CurveParams) affineFromJacobian(x, y, z *big.Int) (xOut, yOut *big.
 }
 
 func (curve *CurveParams) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) {
+	// If there is a dedicated constant-time implementation for this curve operation,
+	// use that instead of the generic one.
+	if specific, ok := matchesSpecificCurve(curve, p224, p521); ok {
+		return specific.Add(x1, y1, x2, y2)
+	}
+
 	z1 := zForAffine(x1, y1)
 	z2 := zForAffine(x2, y2)
 	return curve.affineFromJacobian(curve.addJacobian(x1, y1, z1, x2, y2, z2))
@@ -192,6 +213,12 @@ func (curve *CurveParams) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int
 }
 
 func (curve *CurveParams) Double(x1, y1 *big.Int) (*big.Int, *big.Int) {
+	// If there is a dedicated constant-time implementation for this curve operation,
+	// use that instead of the generic one.
+	if specific, ok := matchesSpecificCurve(curve, p224, p521); ok {
+		return specific.Double(x1, y1)
+	}
+
 	z1 := zForAffine(x1, y1)
 	return curve.affineFromJacobian(curve.doubleJacobian(x1, y1, z1))
 }
@@ -258,6 +285,12 @@ func (curve *CurveParams) doubleJacobian(x, y, z *big.Int) (*big.Int, *big.Int,
 }
 
 func (curve *CurveParams) ScalarMult(Bx, By *big.Int, k []byte) (*big.Int, *big.Int) {
+	// If there is a dedicated constant-time implementation for this curve operation,
+	// use that instead of the generic one.
+	if specific, ok := matchesSpecificCurve(curve, p224, p256, p521); ok {
+		return specific.ScalarMult(Bx, By, k)
+	}
+
 	Bz := new(big.Int).SetInt64(1)
 	x, y, z := new(big.Int), new(big.Int), new(big.Int)
 
@@ -275,6 +308,12 @@ func (curve *CurveParams) ScalarMult(Bx, By *big.Int, k []byte) (*big.Int, *big.
 }
 
 func (curve *CurveParams) ScalarBaseMult(k []byte) (*big.Int, *big.Int) {
+	// If there is a dedicated constant-time implementation for this curve operation,
+	// use that instead of the generic one.
+	if specific, ok := matchesSpecificCurve(curve, p224, p256, p521); ok {
+		return specific.ScalarBaseMult(k)
+	}
+
 	return curve.ScalarMult(curve.Gx, curve.Gy, k)
 }
 
@@ -390,7 +429,6 @@ func UnmarshalCompressed(curve Curve, data []byte) (x, y *big.Int) {
 
 var initonce sync.Once
 var p384 *CurveParams
-var p521 *CurveParams
 
 func initAll() {
 	initP224()
@@ -410,17 +448,6 @@ func initP384() {
 	p384.BitSize = 384
 }
 
-func initP521() {
-	// See FIPS 186-3, section D.2.5
-	p521 = &CurveParams{Name: "P-521"}
-	p521.P, _ = new(big.Int).SetString("6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151", 10)
-	p521.N, _ = new(big.Int).SetString("6864797660130609714981900799081393217269435300143305409394463459185543183397655394245057746333217197532963996371363321113864768612440380340372808892707005449", 10)
-	p521.B, _ = new(big.Int).SetString("051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00", 16)
-	p521.Gx, _ = new(big.Int).SetString("c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66", 16)
-	p521.Gy, _ = new(big.Int).SetString("11839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650", 16)
-	p521.BitSize = 521
-}
-
 // P256 returns a Curve which implements NIST P-256 (FIPS 186-3, section D.2.3),
 // also known as secp256r1 or prime256v1. The CurveParams.Name of this Curve is
 // "P-256".
@@ -428,7 +455,7 @@ func initP521() {
 // Multiple invocations of this function will return the same value, so it can
 // be used for equality checks and switch statements.
 //
-// The cryptographic operations are implemented using constant-time algorithms.
+// ScalarMult and ScalarBaseMult are implemented using constant-time algorithms.
 func P256() Curve {
 	initonce.Do(initAll)
 	return p256
@@ -452,7 +479,7 @@ func P384() Curve {
 // Multiple invocations of this function will return the same value, so it can
 // be used for equality checks and switch statements.
 //
-// The cryptographic operations do not use constant-time algorithms.
+// The cryptographic operations are implemented using constant-time algorithms.
 func P521() Curve {
 	initonce.Do(initAll)
 	return p521
diff --git a/src/crypto/elliptic/elliptic_test.go b/src/crypto/elliptic/elliptic_test.go
index 0d43b736f9a..183861a54b5 100644
--- a/src/crypto/elliptic/elliptic_test.go
+++ b/src/crypto/elliptic/elliptic_test.go
@@ -12,19 +12,29 @@ import (
 	"testing"
 )
 
+// genericParamsForCurve returns the dereferenced CurveParams for
+// the specified curve. This is used to avoid the logic for
+// upgrading a curve to it's specific implementation, forcing
+// usage of the generic implementation. This is only relevant
+// for the P224, P256, and P521 curves.
+func genericParamsForCurve(c Curve) *CurveParams {
+	d := *(c.Params())
+	return &d
+}
+
 func testAllCurves(t *testing.T, f func(*testing.T, Curve)) {
 	tests := []struct {
 		name  string
 		curve Curve
 	}{
 		{"P256", P256()},
-		{"P256/Params", P256().Params()},
+		{"P256/Params", genericParamsForCurve(P256())},
 		{"P224", P224()},
-		{"P224/Params", P224().Params()},
+		{"P224/Params", genericParamsForCurve(P224())},
 		{"P384", P384()},
-		{"P384/Params", P384().Params()},
+		{"P384/Params", genericParamsForCurve(P384())},
 		{"P521", P521()},
-		{"P521/Params", P521().Params()},
+		{"P521/Params", genericParamsForCurve(P521())},
 	}
 	if testing.Short() {
 		tests = tests[:1]
diff --git a/src/crypto/elliptic/internal/fiat/Dockerfile b/src/crypto/elliptic/internal/fiat/Dockerfile
new file mode 100644
index 00000000000..7b5ece0e30f
--- /dev/null
+++ b/src/crypto/elliptic/internal/fiat/Dockerfile
@@ -0,0 +1,12 @@
+# Copyright 2021 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+FROM coqorg/coq:8.13.2
+
+RUN git clone https://github.com/mit-plv/fiat-crypto
+RUN cd fiat-crypto && git checkout c076f3550bea2bb7f4cb5766a32594b9e67694f2
+RUN cd fiat-crypto && git submodule update --init --recursive
+RUN cd fiat-crypto && eval $(opam env) && make -j4 standalone-ocaml SKIP_BEDROCK2=1
+
+ENTRYPOINT ["fiat-crypto/src/ExtractionOCaml/unsaturated_solinas"]
diff --git a/src/crypto/elliptic/internal/fiat/README b/src/crypto/elliptic/internal/fiat/README
new file mode 100644
index 00000000000..171f57a3274
--- /dev/null
+++ b/src/crypto/elliptic/internal/fiat/README
@@ -0,0 +1,39 @@
+The code in this package was autogenerated by the fiat-crypto project
+at commit c076f3550 from a formally verified model.
+
+    docker build -t fiat-crypto:c076f3550 .
+    docker run fiat-crypto:c076f3550 --lang Go --no-wide-int --cmovznz-by-mul \
+        --internal-static --public-function-case camelCase --public-type-case camelCase \
+        --private-function-case camelCase --private-type-case camelCase \
+        --no-prefix-fiat --package-name fiat --doc-text-before-function-name '' \
+        --doc-prepend-header 'Code generated by Fiat Cryptography. DO NOT EDIT.' \
+        --doc-newline-before-package-declaration p521 64 9 '2^521 - 1' \
+        carry_mul carry_square carry add sub to_bytes from_bytes selectznz \
+        > p521_fiat64.go
+
+It comes under the following license.
+
+    Copyright (c) 2015-2020 The fiat-crypto Authors. All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+
+        1. Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+
+    THIS SOFTWARE IS PROVIDED BY the fiat-crypto authors "AS IS"
+    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+    THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design,
+    Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+The authors are listed at
+
+    https://github.com/mit-plv/fiat-crypto/blob/master/AUTHORS
diff --git a/src/crypto/elliptic/internal/fiat/p521.go b/src/crypto/elliptic/internal/fiat/p521.go
new file mode 100644
index 00000000000..dc677327e6d
--- /dev/null
+++ b/src/crypto/elliptic/internal/fiat/p521.go
@@ -0,0 +1,197 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package fiat implements prime order fields using formally verified algorithms
+// from the Fiat Cryptography project.
+package fiat
+
+import (
+	"crypto/subtle"
+	"errors"
+)
+
+// P521Element is an integer modulo 2^521 - 1.
+//
+// The zero value is a valid zero element.
+type P521Element struct {
+	// This element has the following bounds, which are tighter than
+	// the output bounds of some operations. Those operations must be
+	// followed by a carry.
+	//
+	// [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000],
+	// [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000],
+	// [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]
+	x [9]uint64
+}
+
+// One sets e = 1, and returns e.
+func (e *P521Element) One() *P521Element {
+	*e = P521Element{}
+	e.x[0] = 1
+	return e
+}
+
+// Equal returns 1 if e == t, and zero otherwise.
+func (e *P521Element) Equal(t *P521Element) int {
+	eBytes := e.Bytes()
+	tBytes := t.Bytes()
+	return subtle.ConstantTimeCompare(eBytes, tBytes)
+}
+
+var p521ZeroEncoding = new(P521Element).Bytes()
+
+// IsZero returns 1 if e == 0, and zero otherwise.
+func (e *P521Element) IsZero() int {
+	eBytes := e.Bytes()
+	return subtle.ConstantTimeCompare(eBytes, p521ZeroEncoding)
+}
+
+// Set sets e = t, and returns e.
+func (e *P521Element) Set(t *P521Element) *P521Element {
+	e.x = t.x
+	return e
+}
+
+// Bytes returns the 66-byte little-endian encoding of e.
+func (e *P521Element) Bytes() []byte {
+	// This function must be inlined to move the allocation to the parent and
+	// save it from escaping to the heap.
+	var out [66]byte
+	p521ToBytes(&out, &e.x)
+	return out[:]
+}
+
+// SetBytes sets e = v, where v is a little-endian 66-byte encoding, and returns
+// e. If v is not 66 bytes or it encodes a value higher than 2^521 - 1, SetBytes
+// returns nil and an error, and e is unchanged.
+func (e *P521Element) SetBytes(v []byte) (*P521Element, error) {
+	if len(v) != 66 || v[65] > 1 {
+		return nil, errors.New("invalid P-521 field encoding")
+	}
+	var in [66]byte
+	copy(in[:], v)
+	p521FromBytes(&e.x, &in)
+	return e, nil
+}
+
+// Add sets e = t1 + t2, and returns e.
+func (e *P521Element) Add(t1, t2 *P521Element) *P521Element {
+	p521Add(&e.x, &t1.x, &t2.x)
+	p521Carry(&e.x, &e.x)
+	return e
+}
+
+// Sub sets e = t1 - t2, and returns e.
+func (e *P521Element) Sub(t1, t2 *P521Element) *P521Element {
+	p521Sub(&e.x, &t1.x, &t2.x)
+	p521Carry(&e.x, &e.x)
+	return e
+}
+
+// Mul sets e = t1 * t2, and returns e.
+func (e *P521Element) Mul(t1, t2 *P521Element) *P521Element {
+	p521CarryMul(&e.x, &t1.x, &t2.x)
+	return e
+}
+
+// Square sets e = t * t, and returns e.
+func (e *P521Element) Square(t *P521Element) *P521Element {
+	p521CarrySquare(&e.x, &t.x)
+	return e
+}
+
+// Select sets e to a if cond == 1, and to b if cond == 0.
+func (v *P521Element) Select(a, b *P521Element, cond int) *P521Element {
+	p521Selectznz(&v.x, p521Uint1(cond), &b.x, &a.x)
+	return v
+}
+
+// Invert sets e = 1/t, and returns e.
+//
+// If t == 0, Invert returns e = 0.
+func (e *P521Element) Invert(t *P521Element) *P521Element {
+	// Inversion is implemented as exponentiation with exponent p − 2.
+	// The sequence of multiplications and squarings was generated with
+	// github.com/mmcloughlin/addchain v0.2.0.
+
+	var t1, t2 = new(P521Element), new(P521Element)
+
+	// _10 = 2 * 1
+	t1.Square(t)
+
+	// _11 = 1 + _10
+	t1.Mul(t, t1)
+
+	// _1100 = _11 << 2
+	t2.Square(t1)
+	t2.Square(t2)
+
+	// _1111 = _11 + _1100
+	t1.Mul(t1, t2)
+
+	// _11110000 = _1111 << 4
+	t2.Square(t1)
+	for i := 0; i < 3; i++ {
+		t2.Square(t2)
+	}
+
+	// _11111111 = _1111 + _11110000
+	t1.Mul(t1, t2)
+
+	// x16 = _11111111<<8 + _11111111
+	t2.Square(t1)
+	for i := 0; i < 7; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// x32 = x16<<16 + x16
+	t2.Square(t1)
+	for i := 0; i < 15; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// x64 = x32<<32 + x32
+	t2.Square(t1)
+	for i := 0; i < 31; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// x65 = 2*x64 + 1
+	t2.Square(t1)
+	t2.Mul(t2, t)
+
+	// x129 = x65<<64 + x64
+	for i := 0; i < 64; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// x130 = 2*x129 + 1
+	t2.Square(t1)
+	t2.Mul(t2, t)
+
+	// x259 = x130<<129 + x129
+	for i := 0; i < 129; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// x260 = 2*x259 + 1
+	t2.Square(t1)
+	t2.Mul(t2, t)
+
+	// x519 = x260<<259 + x259
+	for i := 0; i < 259; i++ {
+		t2.Square(t2)
+	}
+	t1.Mul(t1, t2)
+
+	// return x519<<2 + 1
+	t1.Square(t1)
+	t1.Square(t1)
+	return e.Mul(t1, t)
+}
diff --git a/src/crypto/elliptic/internal/fiat/p521_fiat64.go b/src/crypto/elliptic/internal/fiat/p521_fiat64.go
new file mode 100644
index 00000000000..f86283b587e
--- /dev/null
+++ b/src/crypto/elliptic/internal/fiat/p521_fiat64.go
@@ -0,0 +1,1856 @@
+// Code generated by Fiat Cryptography. DO NOT EDIT.
+//
+// Autogenerated: 'fiat-crypto/src/ExtractionOCaml/unsaturated_solinas' --lang Go --no-wide-int --cmovznz-by-mul --internal-static --public-function-case camelCase --public-type-case camelCase --private-function-case camelCase --private-type-case camelCase --no-prefix-fiat --package-name fiat --doc-text-before-function-name '' --doc-prepend-header 'Code generated by Fiat Cryptography. DO NOT EDIT.' --doc-newline-before-package-declaration p521 64 9 '2^521 - 1' carry_mul carry_square carry add sub to_bytes from_bytes selectznz
+//
+// curve description: p521
+//
+// machine_wordsize = 64 (from "64")
+//
+// requested operations: carry_mul, carry_square, carry, add, sub, to_bytes, from_bytes, selectznz
+//
+// n = 9 (from "9")
+//
+// s-c = 2^521 - [(1, 1)] (from "2^521 - 1")
+//
+// tight_bounds_multiplier = 1 (from "")
+//
+//
+//
+// Computed values:
+//
+//   carry_chain = [0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1]
+//
+//   eval z = z[0] + (z[1] << 58) + (z[2] << 116) + (z[3] << 174) + (z[4] << 232) + (z[5] << 0x122) + (z[6] << 0x15c) + (z[7] << 0x196) + (z[8] << 0x1d0)
+//
+//   bytes_eval z = z[0] + (z[1] << 8) + (z[2] << 16) + (z[3] << 24) + (z[4] << 32) + (z[5] << 40) + (z[6] << 48) + (z[7] << 56) + (z[8] << 64) + (z[9] << 72) + (z[10] << 80) + (z[11] << 88) + (z[12] << 96) + (z[13] << 104) + (z[14] << 112) + (z[15] << 120) + (z[16] << 128) + (z[17] << 136) + (z[18] << 144) + (z[19] << 152) + (z[20] << 160) + (z[21] << 168) + (z[22] << 176) + (z[23] << 184) + (z[24] << 192) + (z[25] << 200) + (z[26] << 208) + (z[27] << 216) + (z[28] << 224) + (z[29] << 232) + (z[30] << 240) + (z[31] << 248) + (z[32] << 256) + (z[33] << 0x108) + (z[34] << 0x110) + (z[35] << 0x118) + (z[36] << 0x120) + (z[37] << 0x128) + (z[38] << 0x130) + (z[39] << 0x138) + (z[40] << 0x140) + (z[41] << 0x148) + (z[42] << 0x150) + (z[43] << 0x158) + (z[44] << 0x160) + (z[45] << 0x168) + (z[46] << 0x170) + (z[47] << 0x178) + (z[48] << 0x180) + (z[49] << 0x188) + (z[50] << 0x190) + (z[51] << 0x198) + (z[52] << 0x1a0) + (z[53] << 0x1a8) + (z[54] << 0x1b0) + (z[55] << 0x1b8) + (z[56] << 0x1c0) + (z[57] << 0x1c8) + (z[58] << 0x1d0) + (z[59] << 0x1d8) + (z[60] << 0x1e0) + (z[61] << 0x1e8) + (z[62] << 0x1f0) + (z[63] << 0x1f8) + (z[64] << 2^9) + (z[65] << 0x208)
+//
+//   balance = [0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x7fffffffffffffe, 0x3fffffffffffffe]
+
+package fiat
+
+import "math/bits"
+
+type p521Uint1 uint8
+type p521Int1 int8
+
+// p521AddcarryxU64 is a thin wrapper around bits.Add64 that uses p521Uint1 rather than uint64
+func p521AddcarryxU64(x uint64, y uint64, carry p521Uint1) (uint64, p521Uint1) {
+	sum, carryOut := bits.Add64(x, y, uint64(carry))
+	return sum, p521Uint1(carryOut)
+}
+
+// p521SubborrowxU64 is a thin wrapper around bits.Sub64 that uses p521Uint1 rather than uint64
+func p521SubborrowxU64(x uint64, y uint64, carry p521Uint1) (uint64, p521Uint1) {
+	sum, carryOut := bits.Sub64(x, y, uint64(carry))
+	return sum, p521Uint1(carryOut)
+}
+
+// p521AddcarryxU58 is an addition with carry.
+//
+// Postconditions:
+//   out1 = (arg1 + arg2 + arg3) mod 2^58
+//   out2 = ⌊(arg1 + arg2 + arg3) / 2^58⌋
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [0x0 ~> 0x3ffffffffffffff]
+//   arg3: [0x0 ~> 0x3ffffffffffffff]
+// Output Bounds:
+//   out1: [0x0 ~> 0x3ffffffffffffff]
+//   out2: [0x0 ~> 0x1]
+func p521AddcarryxU58(out1 *uint64, out2 *p521Uint1, arg1 p521Uint1, arg2 uint64, arg3 uint64) {
+	x1 := ((uint64(arg1) + arg2) + arg3)
+	x2 := (x1 & 0x3ffffffffffffff)
+	x3 := p521Uint1((x1 >> 58))
+	*out1 = x2
+	*out2 = x3
+}
+
+// p521SubborrowxU58 is a subtraction with borrow.
+//
+// Postconditions:
+//   out1 = (-arg1 + arg2 + -arg3) mod 2^58
+//   out2 = -⌊(-arg1 + arg2 + -arg3) / 2^58⌋
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [0x0 ~> 0x3ffffffffffffff]
+//   arg3: [0x0 ~> 0x3ffffffffffffff]
+// Output Bounds:
+//   out1: [0x0 ~> 0x3ffffffffffffff]
+//   out2: [0x0 ~> 0x1]
+func p521SubborrowxU58(out1 *uint64, out2 *p521Uint1, arg1 p521Uint1, arg2 uint64, arg3 uint64) {
+	x1 := ((int64(arg2) - int64(arg1)) - int64(arg3))
+	x2 := p521Int1((x1 >> 58))
+	x3 := (uint64(x1) & 0x3ffffffffffffff)
+	*out1 = x3
+	*out2 = (0x0 - p521Uint1(x2))
+}
+
+// p521AddcarryxU57 is an addition with carry.
+//
+// Postconditions:
+//   out1 = (arg1 + arg2 + arg3) mod 2^57
+//   out2 = ⌊(arg1 + arg2 + arg3) / 2^57⌋
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [0x0 ~> 0x1ffffffffffffff]
+//   arg3: [0x0 ~> 0x1ffffffffffffff]
+// Output Bounds:
+//   out1: [0x0 ~> 0x1ffffffffffffff]
+//   out2: [0x0 ~> 0x1]
+func p521AddcarryxU57(out1 *uint64, out2 *p521Uint1, arg1 p521Uint1, arg2 uint64, arg3 uint64) {
+	x1 := ((uint64(arg1) + arg2) + arg3)
+	x2 := (x1 & 0x1ffffffffffffff)
+	x3 := p521Uint1((x1 >> 57))
+	*out1 = x2
+	*out2 = x3
+}
+
+// p521SubborrowxU57 is a subtraction with borrow.
+//
+// Postconditions:
+//   out1 = (-arg1 + arg2 + -arg3) mod 2^57
+//   out2 = -⌊(-arg1 + arg2 + -arg3) / 2^57⌋
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [0x0 ~> 0x1ffffffffffffff]
+//   arg3: [0x0 ~> 0x1ffffffffffffff]
+// Output Bounds:
+//   out1: [0x0 ~> 0x1ffffffffffffff]
+//   out2: [0x0 ~> 0x1]
+func p521SubborrowxU57(out1 *uint64, out2 *p521Uint1, arg1 p521Uint1, arg2 uint64, arg3 uint64) {
+	x1 := ((int64(arg2) - int64(arg1)) - int64(arg3))
+	x2 := p521Int1((x1 >> 57))
+	x3 := (uint64(x1) & 0x1ffffffffffffff)
+	*out1 = x3
+	*out2 = (0x0 - p521Uint1(x2))
+}
+
+// p521CmovznzU64 is a single-word conditional move.
+//
+// Postconditions:
+//   out1 = (if arg1 = 0 then arg2 else arg3)
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [0x0 ~> 0xffffffffffffffff]
+//   arg3: [0x0 ~> 0xffffffffffffffff]
+// Output Bounds:
+//   out1: [0x0 ~> 0xffffffffffffffff]
+func p521CmovznzU64(out1 *uint64, arg1 p521Uint1, arg2 uint64, arg3 uint64) {
+	x1 := (uint64(arg1) * 0xffffffffffffffff)
+	x2 := ((x1 & arg3) | ((^x1) & arg2))
+	*out1 = x2
+}
+
+// p521CarryMul multiplies two field elements and reduces the result.
+//
+// Postconditions:
+//   eval out1 mod m = (eval arg1 * eval arg2) mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+//   arg2: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+func p521CarryMul(out1 *[9]uint64, arg1 *[9]uint64, arg2 *[9]uint64) {
+	var x1 uint64
+	var x2 uint64
+	x2, x1 = bits.Mul64(arg1[8], (arg2[8] * 0x2))
+	var x3 uint64
+	var x4 uint64
+	x4, x3 = bits.Mul64(arg1[8], (arg2[7] * 0x2))
+	var x5 uint64
+	var x6 uint64
+	x6, x5 = bits.Mul64(arg1[8], (arg2[6] * 0x2))
+	var x7 uint64
+	var x8 uint64
+	x8, x7 = bits.Mul64(arg1[8], (arg2[5] * 0x2))
+	var x9 uint64
+	var x10 uint64
+	x10, x9 = bits.Mul64(arg1[8], (arg2[4] * 0x2))
+	var x11 uint64
+	var x12 uint64
+	x12, x11 = bits.Mul64(arg1[8], (arg2[3] * 0x2))
+	var x13 uint64
+	var x14 uint64
+	x14, x13 = bits.Mul64(arg1[8], (arg2[2] * 0x2))
+	var x15 uint64
+	var x16 uint64
+	x16, x15 = bits.Mul64(arg1[8], (arg2[1] * 0x2))
+	var x17 uint64
+	var x18 uint64
+	x18, x17 = bits.Mul64(arg1[7], (arg2[8] * 0x2))
+	var x19 uint64
+	var x20 uint64
+	x20, x19 = bits.Mul64(arg1[7], (arg2[7] * 0x2))
+	var x21 uint64
+	var x22 uint64
+	x22, x21 = bits.Mul64(arg1[7], (arg2[6] * 0x2))
+	var x23 uint64
+	var x24 uint64
+	x24, x23 = bits.Mul64(arg1[7], (arg2[5] * 0x2))
+	var x25 uint64
+	var x26 uint64
+	x26, x25 = bits.Mul64(arg1[7], (arg2[4] * 0x2))
+	var x27 uint64
+	var x28 uint64
+	x28, x27 = bits.Mul64(arg1[7], (arg2[3] * 0x2))
+	var x29 uint64
+	var x30 uint64
+	x30, x29 = bits.Mul64(arg1[7], (arg2[2] * 0x2))
+	var x31 uint64
+	var x32 uint64
+	x32, x31 = bits.Mul64(arg1[6], (arg2[8] * 0x2))
+	var x33 uint64
+	var x34 uint64
+	x34, x33 = bits.Mul64(arg1[6], (arg2[7] * 0x2))
+	var x35 uint64
+	var x36 uint64
+	x36, x35 = bits.Mul64(arg1[6], (arg2[6] * 0x2))
+	var x37 uint64
+	var x38 uint64
+	x38, x37 = bits.Mul64(arg1[6], (arg2[5] * 0x2))
+	var x39 uint64
+	var x40 uint64
+	x40, x39 = bits.Mul64(arg1[6], (arg2[4] * 0x2))
+	var x41 uint64
+	var x42 uint64
+	x42, x41 = bits.Mul64(arg1[6], (arg2[3] * 0x2))
+	var x43 uint64
+	var x44 uint64
+	x44, x43 = bits.Mul64(arg1[5], (arg2[8] * 0x2))
+	var x45 uint64
+	var x46 uint64
+	x46, x45 = bits.Mul64(arg1[5], (arg2[7] * 0x2))
+	var x47 uint64
+	var x48 uint64
+	x48, x47 = bits.Mul64(arg1[5], (arg2[6] * 0x2))
+	var x49 uint64
+	var x50 uint64
+	x50, x49 = bits.Mul64(arg1[5], (arg2[5] * 0x2))
+	var x51 uint64
+	var x52 uint64
+	x52, x51 = bits.Mul64(arg1[5], (arg2[4] * 0x2))
+	var x53 uint64
+	var x54 uint64
+	x54, x53 = bits.Mul64(arg1[4], (arg2[8] * 0x2))
+	var x55 uint64
+	var x56 uint64
+	x56, x55 = bits.Mul64(arg1[4], (arg2[7] * 0x2))
+	var x57 uint64
+	var x58 uint64
+	x58, x57 = bits.Mul64(arg1[4], (arg2[6] * 0x2))
+	var x59 uint64
+	var x60 uint64
+	x60, x59 = bits.Mul64(arg1[4], (arg2[5] * 0x2))
+	var x61 uint64
+	var x62 uint64
+	x62, x61 = bits.Mul64(arg1[3], (arg2[8] * 0x2))
+	var x63 uint64
+	var x64 uint64
+	x64, x63 = bits.Mul64(arg1[3], (arg2[7] * 0x2))
+	var x65 uint64
+	var x66 uint64
+	x66, x65 = bits.Mul64(arg1[3], (arg2[6] * 0x2))
+	var x67 uint64
+	var x68 uint64
+	x68, x67 = bits.Mul64(arg1[2], (arg2[8] * 0x2))
+	var x69 uint64
+	var x70 uint64
+	x70, x69 = bits.Mul64(arg1[2], (arg2[7] * 0x2))
+	var x71 uint64
+	var x72 uint64
+	x72, x71 = bits.Mul64(arg1[1], (arg2[8] * 0x2))
+	var x73 uint64
+	var x74 uint64
+	x74, x73 = bits.Mul64(arg1[8], arg2[0])
+	var x75 uint64
+	var x76 uint64
+	x76, x75 = bits.Mul64(arg1[7], arg2[1])
+	var x77 uint64
+	var x78 uint64
+	x78, x77 = bits.Mul64(arg1[7], arg2[0])
+	var x79 uint64
+	var x80 uint64
+	x80, x79 = bits.Mul64(arg1[6], arg2[2])
+	var x81 uint64
+	var x82 uint64
+	x82, x81 = bits.Mul64(arg1[6], arg2[1])
+	var x83 uint64
+	var x84 uint64
+	x84, x83 = bits.Mul64(arg1[6], arg2[0])
+	var x85 uint64
+	var x86 uint64
+	x86, x85 = bits.Mul64(arg1[5], arg2[3])
+	var x87 uint64
+	var x88 uint64
+	x88, x87 = bits.Mul64(arg1[5], arg2[2])
+	var x89 uint64
+	var x90 uint64
+	x90, x89 = bits.Mul64(arg1[5], arg2[1])
+	var x91 uint64
+	var x92 uint64
+	x92, x91 = bits.Mul64(arg1[5], arg2[0])
+	var x93 uint64
+	var x94 uint64
+	x94, x93 = bits.Mul64(arg1[4], arg2[4])
+	var x95 uint64
+	var x96 uint64
+	x96, x95 = bits.Mul64(arg1[4], arg2[3])
+	var x97 uint64
+	var x98 uint64
+	x98, x97 = bits.Mul64(arg1[4], arg2[2])
+	var x99 uint64
+	var x100 uint64
+	x100, x99 = bits.Mul64(arg1[4], arg2[1])
+	var x101 uint64
+	var x102 uint64
+	x102, x101 = bits.Mul64(arg1[4], arg2[0])
+	var x103 uint64
+	var x104 uint64
+	x104, x103 = bits.Mul64(arg1[3], arg2[5])
+	var x105 uint64
+	var x106 uint64
+	x106, x105 = bits.Mul64(arg1[3], arg2[4])
+	var x107 uint64
+	var x108 uint64
+	x108, x107 = bits.Mul64(arg1[3], arg2[3])
+	var x109 uint64
+	var x110 uint64
+	x110, x109 = bits.Mul64(arg1[3], arg2[2])
+	var x111 uint64
+	var x112 uint64
+	x112, x111 = bits.Mul64(arg1[3], arg2[1])
+	var x113 uint64
+	var x114 uint64
+	x114, x113 = bits.Mul64(arg1[3], arg2[0])
+	var x115 uint64
+	var x116 uint64
+	x116, x115 = bits.Mul64(arg1[2], arg2[6])
+	var x117 uint64
+	var x118 uint64
+	x118, x117 = bits.Mul64(arg1[2], arg2[5])
+	var x119 uint64
+	var x120 uint64
+	x120, x119 = bits.Mul64(arg1[2], arg2[4])
+	var x121 uint64
+	var x122 uint64
+	x122, x121 = bits.Mul64(arg1[2], arg2[3])
+	var x123 uint64
+	var x124 uint64
+	x124, x123 = bits.Mul64(arg1[2], arg2[2])
+	var x125 uint64
+	var x126 uint64
+	x126, x125 = bits.Mul64(arg1[2], arg2[1])
+	var x127 uint64
+	var x128 uint64
+	x128, x127 = bits.Mul64(arg1[2], arg2[0])
+	var x129 uint64
+	var x130 uint64
+	x130, x129 = bits.Mul64(arg1[1], arg2[7])
+	var x131 uint64
+	var x132 uint64
+	x132, x131 = bits.Mul64(arg1[1], arg2[6])
+	var x133 uint64
+	var x134 uint64
+	x134, x133 = bits.Mul64(arg1[1], arg2[5])
+	var x135 uint64
+	var x136 uint64
+	x136, x135 = bits.Mul64(arg1[1], arg2[4])
+	var x137 uint64
+	var x138 uint64
+	x138, x137 = bits.Mul64(arg1[1], arg2[3])
+	var x139 uint64
+	var x140 uint64
+	x140, x139 = bits.Mul64(arg1[1], arg2[2])
+	var x141 uint64
+	var x142 uint64
+	x142, x141 = bits.Mul64(arg1[1], arg2[1])
+	var x143 uint64
+	var x144 uint64
+	x144, x143 = bits.Mul64(arg1[1], arg2[0])
+	var x145 uint64
+	var x146 uint64
+	x146, x145 = bits.Mul64(arg1[0], arg2[8])
+	var x147 uint64
+	var x148 uint64
+	x148, x147 = bits.Mul64(arg1[0], arg2[7])
+	var x149 uint64
+	var x150 uint64
+	x150, x149 = bits.Mul64(arg1[0], arg2[6])
+	var x151 uint64
+	var x152 uint64
+	x152, x151 = bits.Mul64(arg1[0], arg2[5])
+	var x153 uint64
+	var x154 uint64
+	x154, x153 = bits.Mul64(arg1[0], arg2[4])
+	var x155 uint64
+	var x156 uint64
+	x156, x155 = bits.Mul64(arg1[0], arg2[3])
+	var x157 uint64
+	var x158 uint64
+	x158, x157 = bits.Mul64(arg1[0], arg2[2])
+	var x159 uint64
+	var x160 uint64
+	x160, x159 = bits.Mul64(arg1[0], arg2[1])
+	var x161 uint64
+	var x162 uint64
+	x162, x161 = bits.Mul64(arg1[0], arg2[0])
+	var x163 uint64
+	var x164 p521Uint1
+	x163, x164 = p521AddcarryxU64(x29, x15, 0x0)
+	var x165 uint64
+	x165, _ = p521AddcarryxU64(x30, x16, x164)
+	var x167 uint64
+	var x168 p521Uint1
+	x167, x168 = p521AddcarryxU64(x41, x163, 0x0)
+	var x169 uint64
+	x169, _ = p521AddcarryxU64(x42, x165, x168)
+	var x171 uint64
+	var x172 p521Uint1
+	x171, x172 = p521AddcarryxU64(x51, x167, 0x0)
+	var x173 uint64
+	x173, _ = p521AddcarryxU64(x52, x169, x172)
+	var x175 uint64
+	var x176 p521Uint1
+	x175, x176 = p521AddcarryxU64(x59, x171, 0x0)
+	var x177 uint64
+	x177, _ = p521AddcarryxU64(x60, x173, x176)
+	var x179 uint64
+	var x180 p521Uint1
+	x179, x180 = p521AddcarryxU64(x65, x175, 0x0)
+	var x181 uint64
+	x181, _ = p521AddcarryxU64(x66, x177, x180)
+	var x183 uint64
+	var x184 p521Uint1
+	x183, x184 = p521AddcarryxU64(x69, x179, 0x0)
+	var x185 uint64
+	x185, _ = p521AddcarryxU64(x70, x181, x184)
+	var x187 uint64
+	var x188 p521Uint1
+	x187, x188 = p521AddcarryxU64(x71, x183, 0x0)
+	var x189 uint64
+	x189, _ = p521AddcarryxU64(x72, x185, x188)
+	var x191 uint64
+	var x192 p521Uint1
+	x191, x192 = p521AddcarryxU64(x161, x187, 0x0)
+	var x193 uint64
+	x193, _ = p521AddcarryxU64(x162, x189, x192)
+	x195 := ((x191 >> 58) | ((x193 << 6) & 0xffffffffffffffff))
+	x196 := (x193 >> 58)
+	x197 := (x191 & 0x3ffffffffffffff)
+	var x198 uint64
+	var x199 p521Uint1
+	x198, x199 = p521AddcarryxU64(x75, x73, 0x0)
+	var x200 uint64
+	x200, _ = p521AddcarryxU64(x76, x74, x199)
+	var x202 uint64
+	var x203 p521Uint1
+	x202, x203 = p521AddcarryxU64(x79, x198, 0x0)
+	var x204 uint64
+	x204, _ = p521AddcarryxU64(x80, x200, x203)
+	var x206 uint64
+	var x207 p521Uint1
+	x206, x207 = p521AddcarryxU64(x85, x202, 0x0)
+	var x208 uint64
+	x208, _ = p521AddcarryxU64(x86, x204, x207)
+	var x210 uint64
+	var x211 p521Uint1
+	x210, x211 = p521AddcarryxU64(x93, x206, 0x0)
+	var x212 uint64
+	x212, _ = p521AddcarryxU64(x94, x208, x211)
+	var x214 uint64
+	var x215 p521Uint1
+	x214, x215 = p521AddcarryxU64(x103, x210, 0x0)
+	var x216 uint64
+	x216, _ = p521AddcarryxU64(x104, x212, x215)
+	var x218 uint64
+	var x219 p521Uint1
+	x218, x219 = p521AddcarryxU64(x115, x214, 0x0)
+	var x220 uint64
+	x220, _ = p521AddcarryxU64(x116, x216, x219)
+	var x222 uint64
+	var x223 p521Uint1
+	x222, x223 = p521AddcarryxU64(x129, x218, 0x0)
+	var x224 uint64
+	x224, _ = p521AddcarryxU64(x130, x220, x223)
+	var x226 uint64
+	var x227 p521Uint1
+	x226, x227 = p521AddcarryxU64(x145, x222, 0x0)
+	var x228 uint64
+	x228, _ = p521AddcarryxU64(x146, x224, x227)
+	var x230 uint64
+	var x231 p521Uint1
+	x230, x231 = p521AddcarryxU64(x77, x1, 0x0)
+	var x232 uint64
+	x232, _ = p521AddcarryxU64(x78, x2, x231)
+	var x234 uint64
+	var x235 p521Uint1
+	x234, x235 = p521AddcarryxU64(x81, x230, 0x0)
+	var x236 uint64
+	x236, _ = p521AddcarryxU64(x82, x232, x235)
+	var x238 uint64
+	var x239 p521Uint1
+	x238, x239 = p521AddcarryxU64(x87, x234, 0x0)
+	var x240 uint64
+	x240, _ = p521AddcarryxU64(x88, x236, x239)
+	var x242 uint64
+	var x243 p521Uint1
+	x242, x243 = p521AddcarryxU64(x95, x238, 0x0)
+	var x244 uint64
+	x244, _ = p521AddcarryxU64(x96, x240, x243)
+	var x246 uint64
+	var x247 p521Uint1
+	x246, x247 = p521AddcarryxU64(x105, x242, 0x0)
+	var x248 uint64
+	x248, _ = p521AddcarryxU64(x106, x244, x247)
+	var x250 uint64
+	var x251 p521Uint1
+	x250, x251 = p521AddcarryxU64(x117, x246, 0x0)
+	var x252 uint64
+	x252, _ = p521AddcarryxU64(x118, x248, x251)
+	var x254 uint64
+	var x255 p521Uint1
+	x254, x255 = p521AddcarryxU64(x131, x250, 0x0)
+	var x256 uint64
+	x256, _ = p521AddcarryxU64(x132, x252, x255)
+	var x258 uint64
+	var x259 p521Uint1
+	x258, x259 = p521AddcarryxU64(x147, x254, 0x0)
+	var x260 uint64
+	x260, _ = p521AddcarryxU64(x148, x256, x259)
+	var x262 uint64
+	var x263 p521Uint1
+	x262, x263 = p521AddcarryxU64(x17, x3, 0x0)
+	var x264 uint64
+	x264, _ = p521AddcarryxU64(x18, x4, x263)
+	var x266 uint64
+	var x267 p521Uint1
+	x266, x267 = p521AddcarryxU64(x83, x262, 0x0)
+	var x268 uint64
+	x268, _ = p521AddcarryxU64(x84, x264, x267)
+	var x270 uint64
+	var x271 p521Uint1
+	x270, x271 = p521AddcarryxU64(x89, x266, 0x0)
+	var x272 uint64
+	x272, _ = p521AddcarryxU64(x90, x268, x271)
+	var x274 uint64
+	var x275 p521Uint1
+	x274, x275 = p521AddcarryxU64(x97, x270, 0x0)
+	var x276 uint64
+	x276, _ = p521AddcarryxU64(x98, x272, x275)
+	var x278 uint64
+	var x279 p521Uint1
+	x278, x279 = p521AddcarryxU64(x107, x274, 0x0)
+	var x280 uint64
+	x280, _ = p521AddcarryxU64(x108, x276, x279)
+	var x282 uint64
+	var x283 p521Uint1
+	x282, x283 = p521AddcarryxU64(x119, x278, 0x0)
+	var x284 uint64
+	x284, _ = p521AddcarryxU64(x120, x280, x283)
+	var x286 uint64
+	var x287 p521Uint1
+	x286, x287 = p521AddcarryxU64(x133, x282, 0x0)
+	var x288 uint64
+	x288, _ = p521AddcarryxU64(x134, x284, x287)
+	var x290 uint64
+	var x291 p521Uint1
+	x290, x291 = p521AddcarryxU64(x149, x286, 0x0)
+	var x292 uint64
+	x292, _ = p521AddcarryxU64(x150, x288, x291)
+	var x294 uint64
+	var x295 p521Uint1
+	x294, x295 = p521AddcarryxU64(x19, x5, 0x0)
+	var x296 uint64
+	x296, _ = p521AddcarryxU64(x20, x6, x295)
+	var x298 uint64
+	var x299 p521Uint1
+	x298, x299 = p521AddcarryxU64(x31, x294, 0x0)
+	var x300 uint64
+	x300, _ = p521AddcarryxU64(x32, x296, x299)
+	var x302 uint64
+	var x303 p521Uint1
+	x302, x303 = p521AddcarryxU64(x91, x298, 0x0)
+	var x304 uint64
+	x304, _ = p521AddcarryxU64(x92, x300, x303)
+	var x306 uint64
+	var x307 p521Uint1
+	x306, x307 = p521AddcarryxU64(x99, x302, 0x0)
+	var x308 uint64
+	x308, _ = p521AddcarryxU64(x100, x304, x307)
+	var x310 uint64
+	var x311 p521Uint1
+	x310, x311 = p521AddcarryxU64(x109, x306, 0x0)
+	var x312 uint64
+	x312, _ = p521AddcarryxU64(x110, x308, x311)
+	var x314 uint64
+	var x315 p521Uint1
+	x314, x315 = p521AddcarryxU64(x121, x310, 0x0)
+	var x316 uint64
+	x316, _ = p521AddcarryxU64(x122, x312, x315)
+	var x318 uint64
+	var x319 p521Uint1
+	x318, x319 = p521AddcarryxU64(x135, x314, 0x0)
+	var x320 uint64
+	x320, _ = p521AddcarryxU64(x136, x316, x319)
+	var x322 uint64
+	var x323 p521Uint1
+	x322, x323 = p521AddcarryxU64(x151, x318, 0x0)
+	var x324 uint64
+	x324, _ = p521AddcarryxU64(x152, x320, x323)
+	var x326 uint64
+	var x327 p521Uint1
+	x326, x327 = p521AddcarryxU64(x21, x7, 0x0)
+	var x328 uint64
+	x328, _ = p521AddcarryxU64(x22, x8, x327)
+	var x330 uint64
+	var x331 p521Uint1
+	x330, x331 = p521AddcarryxU64(x33, x326, 0x0)
+	var x332 uint64
+	x332, _ = p521AddcarryxU64(x34, x328, x331)
+	var x334 uint64
+	var x335 p521Uint1
+	x334, x335 = p521AddcarryxU64(x43, x330, 0x0)
+	var x336 uint64
+	x336, _ = p521AddcarryxU64(x44, x332, x335)
+	var x338 uint64
+	var x339 p521Uint1
+	x338, x339 = p521AddcarryxU64(x101, x334, 0x0)
+	var x340 uint64
+	x340, _ = p521AddcarryxU64(x102, x336, x339)
+	var x342 uint64
+	var x343 p521Uint1
+	x342, x343 = p521AddcarryxU64(x111, x338, 0x0)
+	var x344 uint64
+	x344, _ = p521AddcarryxU64(x112, x340, x343)
+	var x346 uint64
+	var x347 p521Uint1
+	x346, x347 = p521AddcarryxU64(x123, x342, 0x0)
+	var x348 uint64
+	x348, _ = p521AddcarryxU64(x124, x344, x347)
+	var x350 uint64
+	var x351 p521Uint1
+	x350, x351 = p521AddcarryxU64(x137, x346, 0x0)
+	var x352 uint64
+	x352, _ = p521AddcarryxU64(x138, x348, x351)
+	var x354 uint64
+	var x355 p521Uint1
+	x354, x355 = p521AddcarryxU64(x153, x350, 0x0)
+	var x356 uint64
+	x356, _ = p521AddcarryxU64(x154, x352, x355)
+	var x358 uint64
+	var x359 p521Uint1
+	x358, x359 = p521AddcarryxU64(x23, x9, 0x0)
+	var x360 uint64
+	x360, _ = p521AddcarryxU64(x24, x10, x359)
+	var x362 uint64
+	var x363 p521Uint1
+	x362, x363 = p521AddcarryxU64(x35, x358, 0x0)
+	var x364 uint64
+	x364, _ = p521AddcarryxU64(x36, x360, x363)
+	var x366 uint64
+	var x367 p521Uint1
+	x366, x367 = p521AddcarryxU64(x45, x362, 0x0)
+	var x368 uint64
+	x368, _ = p521AddcarryxU64(x46, x364, x367)
+	var x370 uint64
+	var x371 p521Uint1
+	x370, x371 = p521AddcarryxU64(x53, x366, 0x0)
+	var x372 uint64
+	x372, _ = p521AddcarryxU64(x54, x368, x371)
+	var x374 uint64
+	var x375 p521Uint1
+	x374, x375 = p521AddcarryxU64(x113, x370, 0x0)
+	var x376 uint64
+	x376, _ = p521AddcarryxU64(x114, x372, x375)
+	var x378 uint64
+	var x379 p521Uint1
+	x378, x379 = p521AddcarryxU64(x125, x374, 0x0)
+	var x380 uint64
+	x380, _ = p521AddcarryxU64(x126, x376, x379)
+	var x382 uint64
+	var x383 p521Uint1
+	x382, x383 = p521AddcarryxU64(x139, x378, 0x0)
+	var x384 uint64
+	x384, _ = p521AddcarryxU64(x140, x380, x383)
+	var x386 uint64
+	var x387 p521Uint1
+	x386, x387 = p521AddcarryxU64(x155, x382, 0x0)
+	var x388 uint64
+	x388, _ = p521AddcarryxU64(x156, x384, x387)
+	var x390 uint64
+	var x391 p521Uint1
+	x390, x391 = p521AddcarryxU64(x25, x11, 0x0)
+	var x392 uint64
+	x392, _ = p521AddcarryxU64(x26, x12, x391)
+	var x394 uint64
+	var x395 p521Uint1
+	x394, x395 = p521AddcarryxU64(x37, x390, 0x0)
+	var x396 uint64
+	x396, _ = p521AddcarryxU64(x38, x392, x395)
+	var x398 uint64
+	var x399 p521Uint1
+	x398, x399 = p521AddcarryxU64(x47, x394, 0x0)
+	var x400 uint64
+	x400, _ = p521AddcarryxU64(x48, x396, x399)
+	var x402 uint64
+	var x403 p521Uint1
+	x402, x403 = p521AddcarryxU64(x55, x398, 0x0)
+	var x404 uint64
+	x404, _ = p521AddcarryxU64(x56, x400, x403)
+	var x406 uint64
+	var x407 p521Uint1
+	x406, x407 = p521AddcarryxU64(x61, x402, 0x0)
+	var x408 uint64
+	x408, _ = p521AddcarryxU64(x62, x404, x407)
+	var x410 uint64
+	var x411 p521Uint1
+	x410, x411 = p521AddcarryxU64(x127, x406, 0x0)
+	var x412 uint64
+	x412, _ = p521AddcarryxU64(x128, x408, x411)
+	var x414 uint64
+	var x415 p521Uint1
+	x414, x415 = p521AddcarryxU64(x141, x410, 0x0)
+	var x416 uint64
+	x416, _ = p521AddcarryxU64(x142, x412, x415)
+	var x418 uint64
+	var x419 p521Uint1
+	x418, x419 = p521AddcarryxU64(x157, x414, 0x0)
+	var x420 uint64
+	x420, _ = p521AddcarryxU64(x158, x416, x419)
+	var x422 uint64
+	var x423 p521Uint1
+	x422, x423 = p521AddcarryxU64(x27, x13, 0x0)
+	var x424 uint64
+	x424, _ = p521AddcarryxU64(x28, x14, x423)
+	var x426 uint64
+	var x427 p521Uint1
+	x426, x427 = p521AddcarryxU64(x39, x422, 0x0)
+	var x428 uint64
+	x428, _ = p521AddcarryxU64(x40, x424, x427)
+	var x430 uint64
+	var x431 p521Uint1
+	x430, x431 = p521AddcarryxU64(x49, x426, 0x0)
+	var x432 uint64
+	x432, _ = p521AddcarryxU64(x50, x428, x431)
+	var x434 uint64
+	var x435 p521Uint1
+	x434, x435 = p521AddcarryxU64(x57, x430, 0x0)
+	var x436 uint64
+	x436, _ = p521AddcarryxU64(x58, x432, x435)
+	var x438 uint64
+	var x439 p521Uint1
+	x438, x439 = p521AddcarryxU64(x63, x434, 0x0)
+	var x440 uint64
+	x440, _ = p521AddcarryxU64(x64, x436, x439)
+	var x442 uint64
+	var x443 p521Uint1
+	x442, x443 = p521AddcarryxU64(x67, x438, 0x0)
+	var x444 uint64
+	x444, _ = p521AddcarryxU64(x68, x440, x443)
+	var x446 uint64
+	var x447 p521Uint1
+	x446, x447 = p521AddcarryxU64(x143, x442, 0x0)
+	var x448 uint64
+	x448, _ = p521AddcarryxU64(x144, x444, x447)
+	var x450 uint64
+	var x451 p521Uint1
+	x450, x451 = p521AddcarryxU64(x159, x446, 0x0)
+	var x452 uint64
+	x452, _ = p521AddcarryxU64(x160, x448, x451)
+	var x454 uint64
+	var x455 p521Uint1
+	x454, x455 = p521AddcarryxU64(x195, x450, 0x0)
+	var x456 uint64
+	x456, _ = p521AddcarryxU64(x196, x452, x455)
+	x458 := ((x454 >> 58) | ((x456 << 6) & 0xffffffffffffffff))
+	x459 := (x456 >> 58)
+	x460 := (x454 & 0x3ffffffffffffff)
+	var x461 uint64
+	var x462 p521Uint1
+	x461, x462 = p521AddcarryxU64(x458, x418, 0x0)
+	var x463 uint64
+	x463, _ = p521AddcarryxU64(x459, x420, x462)
+	x465 := ((x461 >> 58) | ((x463 << 6) & 0xffffffffffffffff))
+	x466 := (x463 >> 58)
+	x467 := (x461 & 0x3ffffffffffffff)
+	var x468 uint64
+	var x469 p521Uint1
+	x468, x469 = p521AddcarryxU64(x465, x386, 0x0)
+	var x470 uint64
+	x470, _ = p521AddcarryxU64(x466, x388, x469)
+	x472 := ((x468 >> 58) | ((x470 << 6) & 0xffffffffffffffff))
+	x473 := (x470 >> 58)
+	x474 := (x468 & 0x3ffffffffffffff)
+	var x475 uint64
+	var x476 p521Uint1
+	x475, x476 = p521AddcarryxU64(x472, x354, 0x0)
+	var x477 uint64
+	x477, _ = p521AddcarryxU64(x473, x356, x476)
+	x479 := ((x475 >> 58) | ((x477 << 6) & 0xffffffffffffffff))
+	x480 := (x477 >> 58)
+	x481 := (x475 & 0x3ffffffffffffff)
+	var x482 uint64
+	var x483 p521Uint1
+	x482, x483 = p521AddcarryxU64(x479, x322, 0x0)
+	var x484 uint64
+	x484, _ = p521AddcarryxU64(x480, x324, x483)
+	x486 := ((x482 >> 58) | ((x484 << 6) & 0xffffffffffffffff))
+	x487 := (x484 >> 58)
+	x488 := (x482 & 0x3ffffffffffffff)
+	var x489 uint64
+	var x490 p521Uint1
+	x489, x490 = p521AddcarryxU64(x486, x290, 0x0)
+	var x491 uint64
+	x491, _ = p521AddcarryxU64(x487, x292, x490)
+	x493 := ((x489 >> 58) | ((x491 << 6) & 0xffffffffffffffff))
+	x494 := (x491 >> 58)
+	x495 := (x489 & 0x3ffffffffffffff)
+	var x496 uint64
+	var x497 p521Uint1
+	x496, x497 = p521AddcarryxU64(x493, x258, 0x0)
+	var x498 uint64
+	x498, _ = p521AddcarryxU64(x494, x260, x497)
+	x500 := ((x496 >> 58) | ((x498 << 6) & 0xffffffffffffffff))
+	x501 := (x498 >> 58)
+	x502 := (x496 & 0x3ffffffffffffff)
+	var x503 uint64
+	var x504 p521Uint1
+	x503, x504 = p521AddcarryxU64(x500, x226, 0x0)
+	var x505 uint64
+	x505, _ = p521AddcarryxU64(x501, x228, x504)
+	x507 := ((x503 >> 57) | ((x505 << 7) & 0xffffffffffffffff))
+	x508 := (x505 >> 57)
+	x509 := (x503 & 0x1ffffffffffffff)
+	var x510 uint64
+	var x511 p521Uint1
+	x510, x511 = p521AddcarryxU64(x197, x507, 0x0)
+	x512 := (uint64(x511) + x508)
+	x513 := ((x510 >> 58) | ((x512 << 6) & 0xffffffffffffffff))
+	x514 := (x510 & 0x3ffffffffffffff)
+	x515 := (x513 + x460)
+	x516 := p521Uint1((x515 >> 58))
+	x517 := (x515 & 0x3ffffffffffffff)
+	x518 := (uint64(x516) + x467)
+	out1[0] = x514
+	out1[1] = x517
+	out1[2] = x518
+	out1[3] = x474
+	out1[4] = x481
+	out1[5] = x488
+	out1[6] = x495
+	out1[7] = x502
+	out1[8] = x509
+}
+
+// p521CarrySquare squares a field element and reduces the result.
+//
+// Postconditions:
+//   eval out1 mod m = (eval arg1 * eval arg1) mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+func p521CarrySquare(out1 *[9]uint64, arg1 *[9]uint64) {
+	x1 := arg1[8]
+	x2 := (x1 * 0x2)
+	x3 := (arg1[8] * 0x2)
+	x4 := arg1[7]
+	x5 := (x4 * 0x2)
+	x6 := (arg1[7] * 0x2)
+	x7 := arg1[6]
+	x8 := (x7 * 0x2)
+	x9 := (arg1[6] * 0x2)
+	x10 := arg1[5]
+	x11 := (x10 * 0x2)
+	x12 := (arg1[5] * 0x2)
+	x13 := (arg1[4] * 0x2)
+	x14 := (arg1[3] * 0x2)
+	x15 := (arg1[2] * 0x2)
+	x16 := (arg1[1] * 0x2)
+	var x17 uint64
+	var x18 uint64
+	x18, x17 = bits.Mul64(arg1[8], (x1 * 0x2))
+	var x19 uint64
+	var x20 uint64
+	x20, x19 = bits.Mul64(arg1[7], (x2 * 0x2))
+	var x21 uint64
+	var x22 uint64
+	x22, x21 = bits.Mul64(arg1[7], (x4 * 0x2))
+	var x23 uint64
+	var x24 uint64
+	x24, x23 = bits.Mul64(arg1[6], (x2 * 0x2))
+	var x25 uint64
+	var x26 uint64
+	x26, x25 = bits.Mul64(arg1[6], (x5 * 0x2))
+	var x27 uint64
+	var x28 uint64
+	x28, x27 = bits.Mul64(arg1[6], (x7 * 0x2))
+	var x29 uint64
+	var x30 uint64
+	x30, x29 = bits.Mul64(arg1[5], (x2 * 0x2))
+	var x31 uint64
+	var x32 uint64
+	x32, x31 = bits.Mul64(arg1[5], (x5 * 0x2))
+	var x33 uint64
+	var x34 uint64
+	x34, x33 = bits.Mul64(arg1[5], (x8 * 0x2))
+	var x35 uint64
+	var x36 uint64
+	x36, x35 = bits.Mul64(arg1[5], (x10 * 0x2))
+	var x37 uint64
+	var x38 uint64
+	x38, x37 = bits.Mul64(arg1[4], (x2 * 0x2))
+	var x39 uint64
+	var x40 uint64
+	x40, x39 = bits.Mul64(arg1[4], (x5 * 0x2))
+	var x41 uint64
+	var x42 uint64
+	x42, x41 = bits.Mul64(arg1[4], (x8 * 0x2))
+	var x43 uint64
+	var x44 uint64
+	x44, x43 = bits.Mul64(arg1[4], (x11 * 0x2))
+	var x45 uint64
+	var x46 uint64
+	x46, x45 = bits.Mul64(arg1[4], arg1[4])
+	var x47 uint64
+	var x48 uint64
+	x48, x47 = bits.Mul64(arg1[3], (x2 * 0x2))
+	var x49 uint64
+	var x50 uint64
+	x50, x49 = bits.Mul64(arg1[3], (x5 * 0x2))
+	var x51 uint64
+	var x52 uint64
+	x52, x51 = bits.Mul64(arg1[3], (x8 * 0x2))
+	var x53 uint64
+	var x54 uint64
+	x54, x53 = bits.Mul64(arg1[3], x12)
+	var x55 uint64
+	var x56 uint64
+	x56, x55 = bits.Mul64(arg1[3], x13)
+	var x57 uint64
+	var x58 uint64
+	x58, x57 = bits.Mul64(arg1[3], arg1[3])
+	var x59 uint64
+	var x60 uint64
+	x60, x59 = bits.Mul64(arg1[2], (x2 * 0x2))
+	var x61 uint64
+	var x62 uint64
+	x62, x61 = bits.Mul64(arg1[2], (x5 * 0x2))
+	var x63 uint64
+	var x64 uint64
+	x64, x63 = bits.Mul64(arg1[2], x9)
+	var x65 uint64
+	var x66 uint64
+	x66, x65 = bits.Mul64(arg1[2], x12)
+	var x67 uint64
+	var x68 uint64
+	x68, x67 = bits.Mul64(arg1[2], x13)
+	var x69 uint64
+	var x70 uint64
+	x70, x69 = bits.Mul64(arg1[2], x14)
+	var x71 uint64
+	var x72 uint64
+	x72, x71 = bits.Mul64(arg1[2], arg1[2])
+	var x73 uint64
+	var x74 uint64
+	x74, x73 = bits.Mul64(arg1[1], (x2 * 0x2))
+	var x75 uint64
+	var x76 uint64
+	x76, x75 = bits.Mul64(arg1[1], x6)
+	var x77 uint64
+	var x78 uint64
+	x78, x77 = bits.Mul64(arg1[1], x9)
+	var x79 uint64
+	var x80 uint64
+	x80, x79 = bits.Mul64(arg1[1], x12)
+	var x81 uint64
+	var x82 uint64
+	x82, x81 = bits.Mul64(arg1[1], x13)
+	var x83 uint64
+	var x84 uint64
+	x84, x83 = bits.Mul64(arg1[1], x14)
+	var x85 uint64
+	var x86 uint64
+	x86, x85 = bits.Mul64(arg1[1], x15)
+	var x87 uint64
+	var x88 uint64
+	x88, x87 = bits.Mul64(arg1[1], arg1[1])
+	var x89 uint64
+	var x90 uint64
+	x90, x89 = bits.Mul64(arg1[0], x3)
+	var x91 uint64
+	var x92 uint64
+	x92, x91 = bits.Mul64(arg1[0], x6)
+	var x93 uint64
+	var x94 uint64
+	x94, x93 = bits.Mul64(arg1[0], x9)
+	var x95 uint64
+	var x96 uint64
+	x96, x95 = bits.Mul64(arg1[0], x12)
+	var x97 uint64
+	var x98 uint64
+	x98, x97 = bits.Mul64(arg1[0], x13)
+	var x99 uint64
+	var x100 uint64
+	x100, x99 = bits.Mul64(arg1[0], x14)
+	var x101 uint64
+	var x102 uint64
+	x102, x101 = bits.Mul64(arg1[0], x15)
+	var x103 uint64
+	var x104 uint64
+	x104, x103 = bits.Mul64(arg1[0], x16)
+	var x105 uint64
+	var x106 uint64
+	x106, x105 = bits.Mul64(arg1[0], arg1[0])
+	var x107 uint64
+	var x108 p521Uint1
+	x107, x108 = p521AddcarryxU64(x51, x43, 0x0)
+	var x109 uint64
+	x109, _ = p521AddcarryxU64(x52, x44, x108)
+	var x111 uint64
+	var x112 p521Uint1
+	x111, x112 = p521AddcarryxU64(x61, x107, 0x0)
+	var x113 uint64
+	x113, _ = p521AddcarryxU64(x62, x109, x112)
+	var x115 uint64
+	var x116 p521Uint1
+	x115, x116 = p521AddcarryxU64(x73, x111, 0x0)
+	var x117 uint64
+	x117, _ = p521AddcarryxU64(x74, x113, x116)
+	var x119 uint64
+	var x120 p521Uint1
+	x119, x120 = p521AddcarryxU64(x105, x115, 0x0)
+	var x121 uint64
+	x121, _ = p521AddcarryxU64(x106, x117, x120)
+	x123 := ((x119 >> 58) | ((x121 << 6) & 0xffffffffffffffff))
+	x124 := (x121 >> 58)
+	x125 := (x119 & 0x3ffffffffffffff)
+	var x126 uint64
+	var x127 p521Uint1
+	x126, x127 = p521AddcarryxU64(x53, x45, 0x0)
+	var x128 uint64
+	x128, _ = p521AddcarryxU64(x54, x46, x127)
+	var x130 uint64
+	var x131 p521Uint1
+	x130, x131 = p521AddcarryxU64(x63, x126, 0x0)
+	var x132 uint64
+	x132, _ = p521AddcarryxU64(x64, x128, x131)
+	var x134 uint64
+	var x135 p521Uint1
+	x134, x135 = p521AddcarryxU64(x75, x130, 0x0)
+	var x136 uint64
+	x136, _ = p521AddcarryxU64(x76, x132, x135)
+	var x138 uint64
+	var x139 p521Uint1
+	x138, x139 = p521AddcarryxU64(x89, x134, 0x0)
+	var x140 uint64
+	x140, _ = p521AddcarryxU64(x90, x136, x139)
+	var x142 uint64
+	var x143 p521Uint1
+	x142, x143 = p521AddcarryxU64(x55, x17, 0x0)
+	var x144 uint64
+	x144, _ = p521AddcarryxU64(x56, x18, x143)
+	var x146 uint64
+	var x147 p521Uint1
+	x146, x147 = p521AddcarryxU64(x65, x142, 0x0)
+	var x148 uint64
+	x148, _ = p521AddcarryxU64(x66, x144, x147)
+	var x150 uint64
+	var x151 p521Uint1
+	x150, x151 = p521AddcarryxU64(x77, x146, 0x0)
+	var x152 uint64
+	x152, _ = p521AddcarryxU64(x78, x148, x151)
+	var x154 uint64
+	var x155 p521Uint1
+	x154, x155 = p521AddcarryxU64(x91, x150, 0x0)
+	var x156 uint64
+	x156, _ = p521AddcarryxU64(x92, x152, x155)
+	var x158 uint64
+	var x159 p521Uint1
+	x158, x159 = p521AddcarryxU64(x57, x19, 0x0)
+	var x160 uint64
+	x160, _ = p521AddcarryxU64(x58, x20, x159)
+	var x162 uint64
+	var x163 p521Uint1
+	x162, x163 = p521AddcarryxU64(x67, x158, 0x0)
+	var x164 uint64
+	x164, _ = p521AddcarryxU64(x68, x160, x163)
+	var x166 uint64
+	var x167 p521Uint1
+	x166, x167 = p521AddcarryxU64(x79, x162, 0x0)
+	var x168 uint64
+	x168, _ = p521AddcarryxU64(x80, x164, x167)
+	var x170 uint64
+	var x171 p521Uint1
+	x170, x171 = p521AddcarryxU64(x93, x166, 0x0)
+	var x172 uint64
+	x172, _ = p521AddcarryxU64(x94, x168, x171)
+	var x174 uint64
+	var x175 p521Uint1
+	x174, x175 = p521AddcarryxU64(x23, x21, 0x0)
+	var x176 uint64
+	x176, _ = p521AddcarryxU64(x24, x22, x175)
+	var x178 uint64
+	var x179 p521Uint1
+	x178, x179 = p521AddcarryxU64(x69, x174, 0x0)
+	var x180 uint64
+	x180, _ = p521AddcarryxU64(x70, x176, x179)
+	var x182 uint64
+	var x183 p521Uint1
+	x182, x183 = p521AddcarryxU64(x81, x178, 0x0)
+	var x184 uint64
+	x184, _ = p521AddcarryxU64(x82, x180, x183)
+	var x186 uint64
+	var x187 p521Uint1
+	x186, x187 = p521AddcarryxU64(x95, x182, 0x0)
+	var x188 uint64
+	x188, _ = p521AddcarryxU64(x96, x184, x187)
+	var x190 uint64
+	var x191 p521Uint1
+	x190, x191 = p521AddcarryxU64(x29, x25, 0x0)
+	var x192 uint64
+	x192, _ = p521AddcarryxU64(x30, x26, x191)
+	var x194 uint64
+	var x195 p521Uint1
+	x194, x195 = p521AddcarryxU64(x71, x190, 0x0)
+	var x196 uint64
+	x196, _ = p521AddcarryxU64(x72, x192, x195)
+	var x198 uint64
+	var x199 p521Uint1
+	x198, x199 = p521AddcarryxU64(x83, x194, 0x0)
+	var x200 uint64
+	x200, _ = p521AddcarryxU64(x84, x196, x199)
+	var x202 uint64
+	var x203 p521Uint1
+	x202, x203 = p521AddcarryxU64(x97, x198, 0x0)
+	var x204 uint64
+	x204, _ = p521AddcarryxU64(x98, x200, x203)
+	var x206 uint64
+	var x207 p521Uint1
+	x206, x207 = p521AddcarryxU64(x31, x27, 0x0)
+	var x208 uint64
+	x208, _ = p521AddcarryxU64(x32, x28, x207)
+	var x210 uint64
+	var x211 p521Uint1
+	x210, x211 = p521AddcarryxU64(x37, x206, 0x0)
+	var x212 uint64
+	x212, _ = p521AddcarryxU64(x38, x208, x211)
+	var x214 uint64
+	var x215 p521Uint1
+	x214, x215 = p521AddcarryxU64(x85, x210, 0x0)
+	var x216 uint64
+	x216, _ = p521AddcarryxU64(x86, x212, x215)
+	var x218 uint64
+	var x219 p521Uint1
+	x218, x219 = p521AddcarryxU64(x99, x214, 0x0)
+	var x220 uint64
+	x220, _ = p521AddcarryxU64(x100, x216, x219)
+	var x222 uint64
+	var x223 p521Uint1
+	x222, x223 = p521AddcarryxU64(x39, x33, 0x0)
+	var x224 uint64
+	x224, _ = p521AddcarryxU64(x40, x34, x223)
+	var x226 uint64
+	var x227 p521Uint1
+	x226, x227 = p521AddcarryxU64(x47, x222, 0x0)
+	var x228 uint64
+	x228, _ = p521AddcarryxU64(x48, x224, x227)
+	var x230 uint64
+	var x231 p521Uint1
+	x230, x231 = p521AddcarryxU64(x87, x226, 0x0)
+	var x232 uint64
+	x232, _ = p521AddcarryxU64(x88, x228, x231)
+	var x234 uint64
+	var x235 p521Uint1
+	x234, x235 = p521AddcarryxU64(x101, x230, 0x0)
+	var x236 uint64
+	x236, _ = p521AddcarryxU64(x102, x232, x235)
+	var x238 uint64
+	var x239 p521Uint1
+	x238, x239 = p521AddcarryxU64(x41, x35, 0x0)
+	var x240 uint64
+	x240, _ = p521AddcarryxU64(x42, x36, x239)
+	var x242 uint64
+	var x243 p521Uint1
+	x242, x243 = p521AddcarryxU64(x49, x238, 0x0)
+	var x244 uint64
+	x244, _ = p521AddcarryxU64(x50, x240, x243)
+	var x246 uint64
+	var x247 p521Uint1
+	x246, x247 = p521AddcarryxU64(x59, x242, 0x0)
+	var x248 uint64
+	x248, _ = p521AddcarryxU64(x60, x244, x247)
+	var x250 uint64
+	var x251 p521Uint1
+	x250, x251 = p521AddcarryxU64(x103, x246, 0x0)
+	var x252 uint64
+	x252, _ = p521AddcarryxU64(x104, x248, x251)
+	var x254 uint64
+	var x255 p521Uint1
+	x254, x255 = p521AddcarryxU64(x123, x250, 0x0)
+	var x256 uint64
+	x256, _ = p521AddcarryxU64(x124, x252, x255)
+	x258 := ((x254 >> 58) | ((x256 << 6) & 0xffffffffffffffff))
+	x259 := (x256 >> 58)
+	x260 := (x254 & 0x3ffffffffffffff)
+	var x261 uint64
+	var x262 p521Uint1
+	x261, x262 = p521AddcarryxU64(x258, x234, 0x0)
+	var x263 uint64
+	x263, _ = p521AddcarryxU64(x259, x236, x262)
+	x265 := ((x261 >> 58) | ((x263 << 6) & 0xffffffffffffffff))
+	x266 := (x263 >> 58)
+	x267 := (x261 & 0x3ffffffffffffff)
+	var x268 uint64
+	var x269 p521Uint1
+	x268, x269 = p521AddcarryxU64(x265, x218, 0x0)
+	var x270 uint64
+	x270, _ = p521AddcarryxU64(x266, x220, x269)
+	x272 := ((x268 >> 58) | ((x270 << 6) & 0xffffffffffffffff))
+	x273 := (x270 >> 58)
+	x274 := (x268 & 0x3ffffffffffffff)
+	var x275 uint64
+	var x276 p521Uint1
+	x275, x276 = p521AddcarryxU64(x272, x202, 0x0)
+	var x277 uint64
+	x277, _ = p521AddcarryxU64(x273, x204, x276)
+	x279 := ((x275 >> 58) | ((x277 << 6) & 0xffffffffffffffff))
+	x280 := (x277 >> 58)
+	x281 := (x275 & 0x3ffffffffffffff)
+	var x282 uint64
+	var x283 p521Uint1
+	x282, x283 = p521AddcarryxU64(x279, x186, 0x0)
+	var x284 uint64
+	x284, _ = p521AddcarryxU64(x280, x188, x283)
+	x286 := ((x282 >> 58) | ((x284 << 6) & 0xffffffffffffffff))
+	x287 := (x284 >> 58)
+	x288 := (x282 & 0x3ffffffffffffff)
+	var x289 uint64
+	var x290 p521Uint1
+	x289, x290 = p521AddcarryxU64(x286, x170, 0x0)
+	var x291 uint64
+	x291, _ = p521AddcarryxU64(x287, x172, x290)
+	x293 := ((x289 >> 58) | ((x291 << 6) & 0xffffffffffffffff))
+	x294 := (x291 >> 58)
+	x295 := (x289 & 0x3ffffffffffffff)
+	var x296 uint64
+	var x297 p521Uint1
+	x296, x297 = p521AddcarryxU64(x293, x154, 0x0)
+	var x298 uint64
+	x298, _ = p521AddcarryxU64(x294, x156, x297)
+	x300 := ((x296 >> 58) | ((x298 << 6) & 0xffffffffffffffff))
+	x301 := (x298 >> 58)
+	x302 := (x296 & 0x3ffffffffffffff)
+	var x303 uint64
+	var x304 p521Uint1
+	x303, x304 = p521AddcarryxU64(x300, x138, 0x0)
+	var x305 uint64
+	x305, _ = p521AddcarryxU64(x301, x140, x304)
+	x307 := ((x303 >> 57) | ((x305 << 7) & 0xffffffffffffffff))
+	x308 := (x305 >> 57)
+	x309 := (x303 & 0x1ffffffffffffff)
+	var x310 uint64
+	var x311 p521Uint1
+	x310, x311 = p521AddcarryxU64(x125, x307, 0x0)
+	x312 := (uint64(x311) + x308)
+	x313 := ((x310 >> 58) | ((x312 << 6) & 0xffffffffffffffff))
+	x314 := (x310 & 0x3ffffffffffffff)
+	x315 := (x313 + x260)
+	x316 := p521Uint1((x315 >> 58))
+	x317 := (x315 & 0x3ffffffffffffff)
+	x318 := (uint64(x316) + x267)
+	out1[0] = x314
+	out1[1] = x317
+	out1[2] = x318
+	out1[3] = x274
+	out1[4] = x281
+	out1[5] = x288
+	out1[6] = x295
+	out1[7] = x302
+	out1[8] = x309
+}
+
+// p521Carry reduces a field element.
+//
+// Postconditions:
+//   eval out1 mod m = eval arg1 mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+func p521Carry(out1 *[9]uint64, arg1 *[9]uint64) {
+	x1 := arg1[0]
+	x2 := ((x1 >> 58) + arg1[1])
+	x3 := ((x2 >> 58) + arg1[2])
+	x4 := ((x3 >> 58) + arg1[3])
+	x5 := ((x4 >> 58) + arg1[4])
+	x6 := ((x5 >> 58) + arg1[5])
+	x7 := ((x6 >> 58) + arg1[6])
+	x8 := ((x7 >> 58) + arg1[7])
+	x9 := ((x8 >> 58) + arg1[8])
+	x10 := ((x1 & 0x3ffffffffffffff) + (x9 >> 57))
+	x11 := (uint64(p521Uint1((x10 >> 58))) + (x2 & 0x3ffffffffffffff))
+	x12 := (x10 & 0x3ffffffffffffff)
+	x13 := (x11 & 0x3ffffffffffffff)
+	x14 := (uint64(p521Uint1((x11 >> 58))) + (x3 & 0x3ffffffffffffff))
+	x15 := (x4 & 0x3ffffffffffffff)
+	x16 := (x5 & 0x3ffffffffffffff)
+	x17 := (x6 & 0x3ffffffffffffff)
+	x18 := (x7 & 0x3ffffffffffffff)
+	x19 := (x8 & 0x3ffffffffffffff)
+	x20 := (x9 & 0x1ffffffffffffff)
+	out1[0] = x12
+	out1[1] = x13
+	out1[2] = x14
+	out1[3] = x15
+	out1[4] = x16
+	out1[5] = x17
+	out1[6] = x18
+	out1[7] = x19
+	out1[8] = x20
+}
+
+// p521Add adds two field elements.
+//
+// Postconditions:
+//   eval out1 mod m = (eval arg1 + eval arg2) mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+//   arg2: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+func p521Add(out1 *[9]uint64, arg1 *[9]uint64, arg2 *[9]uint64) {
+	x1 := (arg1[0] + arg2[0])
+	x2 := (arg1[1] + arg2[1])
+	x3 := (arg1[2] + arg2[2])
+	x4 := (arg1[3] + arg2[3])
+	x5 := (arg1[4] + arg2[4])
+	x6 := (arg1[5] + arg2[5])
+	x7 := (arg1[6] + arg2[6])
+	x8 := (arg1[7] + arg2[7])
+	x9 := (arg1[8] + arg2[8])
+	out1[0] = x1
+	out1[1] = x2
+	out1[2] = x3
+	out1[3] = x4
+	out1[4] = x5
+	out1[5] = x6
+	out1[6] = x7
+	out1[7] = x8
+	out1[8] = x9
+}
+
+// p521Sub subtracts two field elements.
+//
+// Postconditions:
+//   eval out1 mod m = (eval arg1 - eval arg2) mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+//   arg2: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0xc00000000000000], [0x0 ~> 0x600000000000000]]
+func p521Sub(out1 *[9]uint64, arg1 *[9]uint64, arg2 *[9]uint64) {
+	x1 := ((0x7fffffffffffffe + arg1[0]) - arg2[0])
+	x2 := ((0x7fffffffffffffe + arg1[1]) - arg2[1])
+	x3 := ((0x7fffffffffffffe + arg1[2]) - arg2[2])
+	x4 := ((0x7fffffffffffffe + arg1[3]) - arg2[3])
+	x5 := ((0x7fffffffffffffe + arg1[4]) - arg2[4])
+	x6 := ((0x7fffffffffffffe + arg1[5]) - arg2[5])
+	x7 := ((0x7fffffffffffffe + arg1[6]) - arg2[6])
+	x8 := ((0x7fffffffffffffe + arg1[7]) - arg2[7])
+	x9 := ((0x3fffffffffffffe + arg1[8]) - arg2[8])
+	out1[0] = x1
+	out1[1] = x2
+	out1[2] = x3
+	out1[3] = x4
+	out1[4] = x5
+	out1[5] = x6
+	out1[6] = x7
+	out1[7] = x8
+	out1[8] = x9
+}
+
+// p521ToBytes serializes a field element to bytes in little-endian order.
+//
+// Postconditions:
+//   out1 = map (λ x, ⌊((eval arg1 mod m) mod 2^(8 * (x + 1))) / 2^(8 * x)⌋) [0..65]
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0x1]]
+func p521ToBytes(out1 *[66]uint8, arg1 *[9]uint64) {
+	var x1 uint64
+	var x2 p521Uint1
+	p521SubborrowxU58(&x1, &x2, 0x0, arg1[0], 0x3ffffffffffffff)
+	var x3 uint64
+	var x4 p521Uint1
+	p521SubborrowxU58(&x3, &x4, x2, arg1[1], 0x3ffffffffffffff)
+	var x5 uint64
+	var x6 p521Uint1
+	p521SubborrowxU58(&x5, &x6, x4, arg1[2], 0x3ffffffffffffff)
+	var x7 uint64
+	var x8 p521Uint1
+	p521SubborrowxU58(&x7, &x8, x6, arg1[3], 0x3ffffffffffffff)
+	var x9 uint64
+	var x10 p521Uint1
+	p521SubborrowxU58(&x9, &x10, x8, arg1[4], 0x3ffffffffffffff)
+	var x11 uint64
+	var x12 p521Uint1
+	p521SubborrowxU58(&x11, &x12, x10, arg1[5], 0x3ffffffffffffff)
+	var x13 uint64
+	var x14 p521Uint1
+	p521SubborrowxU58(&x13, &x14, x12, arg1[6], 0x3ffffffffffffff)
+	var x15 uint64
+	var x16 p521Uint1
+	p521SubborrowxU58(&x15, &x16, x14, arg1[7], 0x3ffffffffffffff)
+	var x17 uint64
+	var x18 p521Uint1
+	p521SubborrowxU57(&x17, &x18, x16, arg1[8], 0x1ffffffffffffff)
+	var x19 uint64
+	p521CmovznzU64(&x19, x18, uint64(0x0), 0xffffffffffffffff)
+	var x20 uint64
+	var x21 p521Uint1
+	p521AddcarryxU58(&x20, &x21, 0x0, x1, (x19 & 0x3ffffffffffffff))
+	var x22 uint64
+	var x23 p521Uint1
+	p521AddcarryxU58(&x22, &x23, x21, x3, (x19 & 0x3ffffffffffffff))
+	var x24 uint64
+	var x25 p521Uint1
+	p521AddcarryxU58(&x24, &x25, x23, x5, (x19 & 0x3ffffffffffffff))
+	var x26 uint64
+	var x27 p521Uint1
+	p521AddcarryxU58(&x26, &x27, x25, x7, (x19 & 0x3ffffffffffffff))
+	var x28 uint64
+	var x29 p521Uint1
+	p521AddcarryxU58(&x28, &x29, x27, x9, (x19 & 0x3ffffffffffffff))
+	var x30 uint64
+	var x31 p521Uint1
+	p521AddcarryxU58(&x30, &x31, x29, x11, (x19 & 0x3ffffffffffffff))
+	var x32 uint64
+	var x33 p521Uint1
+	p521AddcarryxU58(&x32, &x33, x31, x13, (x19 & 0x3ffffffffffffff))
+	var x34 uint64
+	var x35 p521Uint1
+	p521AddcarryxU58(&x34, &x35, x33, x15, (x19 & 0x3ffffffffffffff))
+	var x36 uint64
+	var x37 p521Uint1
+	p521AddcarryxU57(&x36, &x37, x35, x17, (x19 & 0x1ffffffffffffff))
+	x38 := (x34 << 6)
+	x39 := (x32 << 4)
+	x40 := (x30 << 2)
+	x41 := (x26 << 6)
+	x42 := (x24 << 4)
+	x43 := (x22 << 2)
+	x44 := (uint8(x20) & 0xff)
+	x45 := (x20 >> 8)
+	x46 := (uint8(x45) & 0xff)
+	x47 := (x45 >> 8)
+	x48 := (uint8(x47) & 0xff)
+	x49 := (x47 >> 8)
+	x50 := (uint8(x49) & 0xff)
+	x51 := (x49 >> 8)
+	x52 := (uint8(x51) & 0xff)
+	x53 := (x51 >> 8)
+	x54 := (uint8(x53) & 0xff)
+	x55 := (x53 >> 8)
+	x56 := (uint8(x55) & 0xff)
+	x57 := uint8((x55 >> 8))
+	x58 := (x43 + uint64(x57))
+	x59 := (uint8(x58) & 0xff)
+	x60 := (x58 >> 8)
+	x61 := (uint8(x60) & 0xff)
+	x62 := (x60 >> 8)
+	x63 := (uint8(x62) & 0xff)
+	x64 := (x62 >> 8)
+	x65 := (uint8(x64) & 0xff)
+	x66 := (x64 >> 8)
+	x67 := (uint8(x66) & 0xff)
+	x68 := (x66 >> 8)
+	x69 := (uint8(x68) & 0xff)
+	x70 := (x68 >> 8)
+	x71 := (uint8(x70) & 0xff)
+	x72 := uint8((x70 >> 8))
+	x73 := (x42 + uint64(x72))
+	x74 := (uint8(x73) & 0xff)
+	x75 := (x73 >> 8)
+	x76 := (uint8(x75) & 0xff)
+	x77 := (x75 >> 8)
+	x78 := (uint8(x77) & 0xff)
+	x79 := (x77 >> 8)
+	x80 := (uint8(x79) & 0xff)
+	x81 := (x79 >> 8)
+	x82 := (uint8(x81) & 0xff)
+	x83 := (x81 >> 8)
+	x84 := (uint8(x83) & 0xff)
+	x85 := (x83 >> 8)
+	x86 := (uint8(x85) & 0xff)
+	x87 := uint8((x85 >> 8))
+	x88 := (x41 + uint64(x87))
+	x89 := (uint8(x88) & 0xff)
+	x90 := (x88 >> 8)
+	x91 := (uint8(x90) & 0xff)
+	x92 := (x90 >> 8)
+	x93 := (uint8(x92) & 0xff)
+	x94 := (x92 >> 8)
+	x95 := (uint8(x94) & 0xff)
+	x96 := (x94 >> 8)
+	x97 := (uint8(x96) & 0xff)
+	x98 := (x96 >> 8)
+	x99 := (uint8(x98) & 0xff)
+	x100 := (x98 >> 8)
+	x101 := (uint8(x100) & 0xff)
+	x102 := uint8((x100 >> 8))
+	x103 := (uint8(x28) & 0xff)
+	x104 := (x28 >> 8)
+	x105 := (uint8(x104) & 0xff)
+	x106 := (x104 >> 8)
+	x107 := (uint8(x106) & 0xff)
+	x108 := (x106 >> 8)
+	x109 := (uint8(x108) & 0xff)
+	x110 := (x108 >> 8)
+	x111 := (uint8(x110) & 0xff)
+	x112 := (x110 >> 8)
+	x113 := (uint8(x112) & 0xff)
+	x114 := (x112 >> 8)
+	x115 := (uint8(x114) & 0xff)
+	x116 := uint8((x114 >> 8))
+	x117 := (x40 + uint64(x116))
+	x118 := (uint8(x117) & 0xff)
+	x119 := (x117 >> 8)
+	x120 := (uint8(x119) & 0xff)
+	x121 := (x119 >> 8)
+	x122 := (uint8(x121) & 0xff)
+	x123 := (x121 >> 8)
+	x124 := (uint8(x123) & 0xff)
+	x125 := (x123 >> 8)
+	x126 := (uint8(x125) & 0xff)
+	x127 := (x125 >> 8)
+	x128 := (uint8(x127) & 0xff)
+	x129 := (x127 >> 8)
+	x130 := (uint8(x129) & 0xff)
+	x131 := uint8((x129 >> 8))
+	x132 := (x39 + uint64(x131))
+	x133 := (uint8(x132) & 0xff)
+	x134 := (x132 >> 8)
+	x135 := (uint8(x134) & 0xff)
+	x136 := (x134 >> 8)
+	x137 := (uint8(x136) & 0xff)
+	x138 := (x136 >> 8)
+	x139 := (uint8(x138) & 0xff)
+	x140 := (x138 >> 8)
+	x141 := (uint8(x140) & 0xff)
+	x142 := (x140 >> 8)
+	x143 := (uint8(x142) & 0xff)
+	x144 := (x142 >> 8)
+	x145 := (uint8(x144) & 0xff)
+	x146 := uint8((x144 >> 8))
+	x147 := (x38 + uint64(x146))
+	x148 := (uint8(x147) & 0xff)
+	x149 := (x147 >> 8)
+	x150 := (uint8(x149) & 0xff)
+	x151 := (x149 >> 8)
+	x152 := (uint8(x151) & 0xff)
+	x153 := (x151 >> 8)
+	x154 := (uint8(x153) & 0xff)
+	x155 := (x153 >> 8)
+	x156 := (uint8(x155) & 0xff)
+	x157 := (x155 >> 8)
+	x158 := (uint8(x157) & 0xff)
+	x159 := (x157 >> 8)
+	x160 := (uint8(x159) & 0xff)
+	x161 := uint8((x159 >> 8))
+	x162 := (uint8(x36) & 0xff)
+	x163 := (x36 >> 8)
+	x164 := (uint8(x163) & 0xff)
+	x165 := (x163 >> 8)
+	x166 := (uint8(x165) & 0xff)
+	x167 := (x165 >> 8)
+	x168 := (uint8(x167) & 0xff)
+	x169 := (x167 >> 8)
+	x170 := (uint8(x169) & 0xff)
+	x171 := (x169 >> 8)
+	x172 := (uint8(x171) & 0xff)
+	x173 := (x171 >> 8)
+	x174 := (uint8(x173) & 0xff)
+	x175 := p521Uint1((x173 >> 8))
+	out1[0] = x44
+	out1[1] = x46
+	out1[2] = x48
+	out1[3] = x50
+	out1[4] = x52
+	out1[5] = x54
+	out1[6] = x56
+	out1[7] = x59
+	out1[8] = x61
+	out1[9] = x63
+	out1[10] = x65
+	out1[11] = x67
+	out1[12] = x69
+	out1[13] = x71
+	out1[14] = x74
+	out1[15] = x76
+	out1[16] = x78
+	out1[17] = x80
+	out1[18] = x82
+	out1[19] = x84
+	out1[20] = x86
+	out1[21] = x89
+	out1[22] = x91
+	out1[23] = x93
+	out1[24] = x95
+	out1[25] = x97
+	out1[26] = x99
+	out1[27] = x101
+	out1[28] = x102
+	out1[29] = x103
+	out1[30] = x105
+	out1[31] = x107
+	out1[32] = x109
+	out1[33] = x111
+	out1[34] = x113
+	out1[35] = x115
+	out1[36] = x118
+	out1[37] = x120
+	out1[38] = x122
+	out1[39] = x124
+	out1[40] = x126
+	out1[41] = x128
+	out1[42] = x130
+	out1[43] = x133
+	out1[44] = x135
+	out1[45] = x137
+	out1[46] = x139
+	out1[47] = x141
+	out1[48] = x143
+	out1[49] = x145
+	out1[50] = x148
+	out1[51] = x150
+	out1[52] = x152
+	out1[53] = x154
+	out1[54] = x156
+	out1[55] = x158
+	out1[56] = x160
+	out1[57] = x161
+	out1[58] = x162
+	out1[59] = x164
+	out1[60] = x166
+	out1[61] = x168
+	out1[62] = x170
+	out1[63] = x172
+	out1[64] = x174
+	out1[65] = uint8(x175)
+}
+
+// p521FromBytes deserializes a field element from bytes in little-endian order.
+//
+// Postconditions:
+//   eval out1 mod m = bytes_eval arg1 mod m
+//
+// Input Bounds:
+//   arg1: [[0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0x1]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x400000000000000], [0x0 ~> 0x200000000000000]]
+func p521FromBytes(out1 *[9]uint64, arg1 *[66]uint8) {
+	x1 := (uint64(p521Uint1(arg1[65])) << 56)
+	x2 := (uint64(arg1[64]) << 48)
+	x3 := (uint64(arg1[63]) << 40)
+	x4 := (uint64(arg1[62]) << 32)
+	x5 := (uint64(arg1[61]) << 24)
+	x6 := (uint64(arg1[60]) << 16)
+	x7 := (uint64(arg1[59]) << 8)
+	x8 := arg1[58]
+	x9 := (uint64(arg1[57]) << 50)
+	x10 := (uint64(arg1[56]) << 42)
+	x11 := (uint64(arg1[55]) << 34)
+	x12 := (uint64(arg1[54]) << 26)
+	x13 := (uint64(arg1[53]) << 18)
+	x14 := (uint64(arg1[52]) << 10)
+	x15 := (uint64(arg1[51]) << 2)
+	x16 := (uint64(arg1[50]) << 52)
+	x17 := (uint64(arg1[49]) << 44)
+	x18 := (uint64(arg1[48]) << 36)
+	x19 := (uint64(arg1[47]) << 28)
+	x20 := (uint64(arg1[46]) << 20)
+	x21 := (uint64(arg1[45]) << 12)
+	x22 := (uint64(arg1[44]) << 4)
+	x23 := (uint64(arg1[43]) << 54)
+	x24 := (uint64(arg1[42]) << 46)
+	x25 := (uint64(arg1[41]) << 38)
+	x26 := (uint64(arg1[40]) << 30)
+	x27 := (uint64(arg1[39]) << 22)
+	x28 := (uint64(arg1[38]) << 14)
+	x29 := (uint64(arg1[37]) << 6)
+	x30 := (uint64(arg1[36]) << 56)
+	x31 := (uint64(arg1[35]) << 48)
+	x32 := (uint64(arg1[34]) << 40)
+	x33 := (uint64(arg1[33]) << 32)
+	x34 := (uint64(arg1[32]) << 24)
+	x35 := (uint64(arg1[31]) << 16)
+	x36 := (uint64(arg1[30]) << 8)
+	x37 := arg1[29]
+	x38 := (uint64(arg1[28]) << 50)
+	x39 := (uint64(arg1[27]) << 42)
+	x40 := (uint64(arg1[26]) << 34)
+	x41 := (uint64(arg1[25]) << 26)
+	x42 := (uint64(arg1[24]) << 18)
+	x43 := (uint64(arg1[23]) << 10)
+	x44 := (uint64(arg1[22]) << 2)
+	x45 := (uint64(arg1[21]) << 52)
+	x46 := (uint64(arg1[20]) << 44)
+	x47 := (uint64(arg1[19]) << 36)
+	x48 := (uint64(arg1[18]) << 28)
+	x49 := (uint64(arg1[17]) << 20)
+	x50 := (uint64(arg1[16]) << 12)
+	x51 := (uint64(arg1[15]) << 4)
+	x52 := (uint64(arg1[14]) << 54)
+	x53 := (uint64(arg1[13]) << 46)
+	x54 := (uint64(arg1[12]) << 38)
+	x55 := (uint64(arg1[11]) << 30)
+	x56 := (uint64(arg1[10]) << 22)
+	x57 := (uint64(arg1[9]) << 14)
+	x58 := (uint64(arg1[8]) << 6)
+	x59 := (uint64(arg1[7]) << 56)
+	x60 := (uint64(arg1[6]) << 48)
+	x61 := (uint64(arg1[5]) << 40)
+	x62 := (uint64(arg1[4]) << 32)
+	x63 := (uint64(arg1[3]) << 24)
+	x64 := (uint64(arg1[2]) << 16)
+	x65 := (uint64(arg1[1]) << 8)
+	x66 := arg1[0]
+	x67 := (x65 + uint64(x66))
+	x68 := (x64 + x67)
+	x69 := (x63 + x68)
+	x70 := (x62 + x69)
+	x71 := (x61 + x70)
+	x72 := (x60 + x71)
+	x73 := (x59 + x72)
+	x74 := (x73 & 0x3ffffffffffffff)
+	x75 := uint8((x73 >> 58))
+	x76 := (x58 + uint64(x75))
+	x77 := (x57 + x76)
+	x78 := (x56 + x77)
+	x79 := (x55 + x78)
+	x80 := (x54 + x79)
+	x81 := (x53 + x80)
+	x82 := (x52 + x81)
+	x83 := (x82 & 0x3ffffffffffffff)
+	x84 := uint8((x82 >> 58))
+	x85 := (x51 + uint64(x84))
+	x86 := (x50 + x85)
+	x87 := (x49 + x86)
+	x88 := (x48 + x87)
+	x89 := (x47 + x88)
+	x90 := (x46 + x89)
+	x91 := (x45 + x90)
+	x92 := (x91 & 0x3ffffffffffffff)
+	x93 := uint8((x91 >> 58))
+	x94 := (x44 + uint64(x93))
+	x95 := (x43 + x94)
+	x96 := (x42 + x95)
+	x97 := (x41 + x96)
+	x98 := (x40 + x97)
+	x99 := (x39 + x98)
+	x100 := (x38 + x99)
+	x101 := (x36 + uint64(x37))
+	x102 := (x35 + x101)
+	x103 := (x34 + x102)
+	x104 := (x33 + x103)
+	x105 := (x32 + x104)
+	x106 := (x31 + x105)
+	x107 := (x30 + x106)
+	x108 := (x107 & 0x3ffffffffffffff)
+	x109 := uint8((x107 >> 58))
+	x110 := (x29 + uint64(x109))
+	x111 := (x28 + x110)
+	x112 := (x27 + x111)
+	x113 := (x26 + x112)
+	x114 := (x25 + x113)
+	x115 := (x24 + x114)
+	x116 := (x23 + x115)
+	x117 := (x116 & 0x3ffffffffffffff)
+	x118 := uint8((x116 >> 58))
+	x119 := (x22 + uint64(x118))
+	x120 := (x21 + x119)
+	x121 := (x20 + x120)
+	x122 := (x19 + x121)
+	x123 := (x18 + x122)
+	x124 := (x17 + x123)
+	x125 := (x16 + x124)
+	x126 := (x125 & 0x3ffffffffffffff)
+	x127 := uint8((x125 >> 58))
+	x128 := (x15 + uint64(x127))
+	x129 := (x14 + x128)
+	x130 := (x13 + x129)
+	x131 := (x12 + x130)
+	x132 := (x11 + x131)
+	x133 := (x10 + x132)
+	x134 := (x9 + x133)
+	x135 := (x7 + uint64(x8))
+	x136 := (x6 + x135)
+	x137 := (x5 + x136)
+	x138 := (x4 + x137)
+	x139 := (x3 + x138)
+	x140 := (x2 + x139)
+	x141 := (x1 + x140)
+	out1[0] = x74
+	out1[1] = x83
+	out1[2] = x92
+	out1[3] = x100
+	out1[4] = x108
+	out1[5] = x117
+	out1[6] = x126
+	out1[7] = x134
+	out1[8] = x141
+}
+
+// p521Selectznz is a multi-limb conditional select.
+//
+// Postconditions:
+//   eval out1 = (if arg1 = 0 then eval arg2 else eval arg3)
+//
+// Input Bounds:
+//   arg1: [0x0 ~> 0x1]
+//   arg2: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff]]
+//   arg3: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff]]
+// Output Bounds:
+//   out1: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff]]
+func p521Selectznz(out1 *[9]uint64, arg1 p521Uint1, arg2 *[9]uint64, arg3 *[9]uint64) {
+	var x1 uint64
+	p521CmovznzU64(&x1, arg1, arg2[0], arg3[0])
+	var x2 uint64
+	p521CmovznzU64(&x2, arg1, arg2[1], arg3[1])
+	var x3 uint64
+	p521CmovznzU64(&x3, arg1, arg2[2], arg3[2])
+	var x4 uint64
+	p521CmovznzU64(&x4, arg1, arg2[3], arg3[3])
+	var x5 uint64
+	p521CmovznzU64(&x5, arg1, arg2[4], arg3[4])
+	var x6 uint64
+	p521CmovznzU64(&x6, arg1, arg2[5], arg3[5])
+	var x7 uint64
+	p521CmovznzU64(&x7, arg1, arg2[6], arg3[6])
+	var x8 uint64
+	p521CmovznzU64(&x8, arg1, arg2[7], arg3[7])
+	var x9 uint64
+	p521CmovznzU64(&x9, arg1, arg2[8], arg3[8])
+	out1[0] = x1
+	out1[1] = x2
+	out1[2] = x3
+	out1[3] = x4
+	out1[4] = x5
+	out1[5] = x6
+	out1[6] = x7
+	out1[7] = x8
+	out1[8] = x9
+}
diff --git a/src/crypto/elliptic/internal/fiat/p521_test.go b/src/crypto/elliptic/internal/fiat/p521_test.go
new file mode 100644
index 00000000000..661bde397e4
--- /dev/null
+++ b/src/crypto/elliptic/internal/fiat/p521_test.go
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fiat_test
+
+import (
+	"crypto/elliptic/internal/fiat"
+	"crypto/rand"
+	"testing"
+)
+
+func p521Random(t *testing.T) *fiat.P521Element {
+	buf := make([]byte, 66)
+	if _, err := rand.Read(buf); err != nil {
+		t.Fatal(err)
+	}
+	buf[65] &= 1
+	e, err := new(fiat.P521Element).SetBytes(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return e
+}
+
+func TestP521Invert(t *testing.T) {
+	a := p521Random(t)
+	inv := new(fiat.P521Element).Invert(a)
+	one := new(fiat.P521Element).Mul(a, inv)
+	if new(fiat.P521Element).One().Equal(one) != 1 {
+		t.Errorf("a * 1/a != 1; got %x for %x", one.Bytes(), a.Bytes())
+	}
+	inv.Invert(new(fiat.P521Element))
+	if new(fiat.P521Element).Equal(inv) != 1 {
+		t.Errorf("1/0 != 0; got %x", inv.Bytes())
+	}
+}
diff --git a/src/crypto/elliptic/p256_asm.go b/src/crypto/elliptic/p256_asm.go
index 08dbd2ea548..9a808f260ac 100644
--- a/src/crypto/elliptic/p256_asm.go
+++ b/src/crypto/elliptic/p256_asm.go
@@ -29,9 +29,7 @@ type (
 	}
 )
 
-var (
-	p256 p256Curve
-)
+var p256 p256Curve
 
 func initP256() {
 	// See FIPS 186-3, section D.2.3
diff --git a/src/crypto/elliptic/p256_generic.go b/src/crypto/elliptic/p256_generic.go
index 8ad56638e95..25762a8f768 100644
--- a/src/crypto/elliptic/p256_generic.go
+++ b/src/crypto/elliptic/p256_generic.go
@@ -7,9 +7,7 @@
 
 package elliptic
 
-var (
-	p256 p256Curve
-)
+var p256 p256Curve
 
 func initP256Arch() {
 	// Use pure Go implementation.
diff --git a/src/crypto/elliptic/p521.go b/src/crypto/elliptic/p521.go
new file mode 100644
index 00000000000..3d355943ec7
--- /dev/null
+++ b/src/crypto/elliptic/p521.go
@@ -0,0 +1,259 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package elliptic
+
+import (
+	"crypto/elliptic/internal/fiat"
+	"math/big"
+)
+
+type p521Curve struct {
+	*CurveParams
+}
+
+var p521 p521Curve
+var p521Params *CurveParams
+
+func initP521() {
+	// See FIPS 186-3, section D.2.5
+	p521.CurveParams = &CurveParams{Name: "P-521"}
+	p521.P, _ = new(big.Int).SetString("6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151", 10)
+	p521.N, _ = new(big.Int).SetString("6864797660130609714981900799081393217269435300143305409394463459185543183397655394245057746333217197532963996371363321113864768612440380340372808892707005449", 10)
+	p521.B, _ = new(big.Int).SetString("051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00", 16)
+	p521.Gx, _ = new(big.Int).SetString("c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66", 16)
+	p521.Gy, _ = new(big.Int).SetString("11839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650", 16)
+	p521.BitSize = 521
+}
+
+func (curve p521Curve) Params() *CurveParams {
+	return curve.CurveParams
+}
+
+func (curve p521Curve) IsOnCurve(x, y *big.Int) bool {
+	x1 := bigIntToFiatP521(x)
+	y1 := bigIntToFiatP521(y)
+	b := bigIntToFiatP521(curve.B) // TODO: precompute this value.
+
+	// x³ - 3x + b.
+	x3 := new(fiat.P521Element).Square(x1)
+	x3.Mul(x3, x1)
+
+	threeX := new(fiat.P521Element).Add(x1, x1)
+	threeX.Add(threeX, x1)
+
+	x3.Sub(x3, threeX)
+	x3.Add(x3, b)
+
+	// y² = x³ - 3x + b
+	y2 := new(fiat.P521Element).Square(y1)
+
+	return x3.Equal(y2) == 1
+}
+
+type p521Point struct {
+	x, y, z *fiat.P521Element
+}
+
+func fiatP521ToBigInt(x *fiat.P521Element) *big.Int {
+	xBytes := x.Bytes()
+	for i := range xBytes[:len(xBytes)/2] {
+		xBytes[i], xBytes[len(xBytes)-i-1] = xBytes[len(xBytes)-i-1], xBytes[i]
+	}
+	return new(big.Int).SetBytes(xBytes)
+}
+
+// affineFromJacobian brings a point in Jacobian coordinates back to affine
+// coordinates, with (0, 0) representing infinity by convention. It also goes
+// back to big.Int values to match the exposed API.
+func (curve p521Curve) affineFromJacobian(p *p521Point) (x, y *big.Int) {
+	if p.z.IsZero() == 1 {
+		return new(big.Int), new(big.Int)
+	}
+
+	zinv := new(fiat.P521Element).Invert(p.z)
+	zinvsq := new(fiat.P521Element).Mul(zinv, zinv)
+
+	xx := new(fiat.P521Element).Mul(p.x, zinvsq)
+	zinvsq.Mul(zinvsq, zinv)
+	yy := new(fiat.P521Element).Mul(p.y, zinvsq)
+
+	return fiatP521ToBigInt(xx), fiatP521ToBigInt(yy)
+}
+
+func bigIntToFiatP521(x *big.Int) *fiat.P521Element {
+	xBytes := new(big.Int).Mod(x, p521.P).FillBytes(make([]byte, 66))
+	for i := range xBytes[:len(xBytes)/2] {
+		xBytes[i], xBytes[len(xBytes)-i-1] = xBytes[len(xBytes)-i-1], xBytes[i]
+	}
+	x1, err := new(fiat.P521Element).SetBytes(xBytes)
+	if err != nil {
+		// The input is reduced modulo P and encoded in a fixed size bytes
+		// slice, this should be impossible.
+		panic("internal error: bigIntToFiatP521")
+	}
+	return x1
+}
+
+// jacobianFromAffine converts (x, y) affine coordinates into (x, y, z) Jacobian
+// coordinates. It also converts from big.Int to fiat, which is necessarily a
+// messy and variable-time operation, which we can't avoid due to the exposed API.
+func (curve p521Curve) jacobianFromAffine(x, y *big.Int) *p521Point {
+	// (0, 0) is by convention the point at infinity, which can't be represented
+	// in affine coordinates, but is (0, 0, 0) in Jacobian.
+	if x.Sign() == 0 && y.Sign() == 0 {
+		return &p521Point{
+			x: new(fiat.P521Element),
+			y: new(fiat.P521Element),
+			z: new(fiat.P521Element),
+		}
+	}
+	return &p521Point{
+		x: bigIntToFiatP521(x),
+		y: bigIntToFiatP521(y),
+		z: new(fiat.P521Element).One(),
+	}
+}
+
+func (curve p521Curve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) {
+	p1 := curve.jacobianFromAffine(x1, y1)
+	p2 := curve.jacobianFromAffine(x2, y2)
+	return curve.affineFromJacobian(p1.addJacobian(p1, p2))
+}
+
+// addJacobian sets q = p1 + p2, and returns q. The points may overlap.
+func (q *p521Point) addJacobian(p1, p2 *p521Point) *p521Point {
+	// https://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-3.html#addition-add-2007-bl
+	z1IsZero := p1.z.IsZero()
+	z2IsZero := p2.z.IsZero()
+
+	z1z1 := new(fiat.P521Element).Square(p1.z)
+	z2z2 := new(fiat.P521Element).Square(p2.z)
+
+	u1 := new(fiat.P521Element).Mul(p1.x, z2z2)
+	u2 := new(fiat.P521Element).Mul(p2.x, z1z1)
+	h := new(fiat.P521Element).Sub(u2, u1)
+	xEqual := h.IsZero() == 1
+	i := new(fiat.P521Element).Add(h, h)
+	i.Square(i)
+	j := new(fiat.P521Element).Mul(h, i)
+
+	s1 := new(fiat.P521Element).Mul(p1.y, p2.z)
+	s1.Mul(s1, z2z2)
+	s2 := new(fiat.P521Element).Mul(p2.y, p1.z)
+	s2.Mul(s2, z1z1)
+	r := new(fiat.P521Element).Sub(s2, s1)
+	yEqual := r.IsZero() == 1
+	if xEqual && yEqual && z1IsZero == 0 && z2IsZero == 0 {
+		return q.doubleJacobian(p1)
+	}
+	r.Add(r, r)
+	v := new(fiat.P521Element).Mul(u1, i)
+
+	x := new(fiat.P521Element).Set(r)
+	x.Square(x)
+	x.Sub(x, j)
+	x.Sub(x, v)
+	x.Sub(x, v)
+
+	y := new(fiat.P521Element).Set(r)
+	v.Sub(v, x)
+	y.Mul(y, v)
+	s1.Mul(s1, j)
+	s1.Add(s1, s1)
+	y.Sub(y, s1)
+
+	z := new(fiat.P521Element).Add(p1.z, p2.z)
+	z.Square(z)
+	z.Sub(z, z1z1)
+	z.Sub(z, z2z2)
+	z.Mul(z, h)
+
+	x.Select(p2.x, x, z1IsZero)
+	x.Select(p1.x, x, z2IsZero)
+	y.Select(p2.y, y, z1IsZero)
+	y.Select(p1.y, y, z2IsZero)
+	z.Select(p2.z, z, z1IsZero)
+	z.Select(p1.z, z, z2IsZero)
+
+	q.x.Set(x)
+	q.y.Set(y)
+	q.z.Set(z)
+	return q
+}
+
+func (curve p521Curve) Double(x1, y1 *big.Int) (*big.Int, *big.Int) {
+	p := curve.jacobianFromAffine(x1, y1)
+	return curve.affineFromJacobian(p.doubleJacobian(p))
+}
+
+// doubleJacobian sets q = p + p, and returns q. The points may overlap.
+func (q *p521Point) doubleJacobian(p *p521Point) *p521Point {
+	// https://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-3.html#doubling-dbl-2001-b
+	delta := new(fiat.P521Element).Square(p.z)
+	gamma := new(fiat.P521Element).Square(p.y)
+	alpha := new(fiat.P521Element).Sub(p.x, delta)
+	alpha2 := new(fiat.P521Element).Add(p.x, delta)
+	alpha.Mul(alpha, alpha2)
+	alpha2.Set(alpha)
+	alpha.Add(alpha, alpha)
+	alpha.Add(alpha, alpha2)
+
+	beta := alpha2.Mul(p.x, gamma)
+
+	q.x.Square(alpha)
+	beta8 := new(fiat.P521Element).Add(beta, beta)
+	beta8.Add(beta8, beta8)
+	beta8.Add(beta8, beta8)
+	q.x.Sub(q.x, beta8)
+
+	q.z.Add(p.y, p.z)
+	q.z.Square(q.z)
+	q.z.Sub(q.z, gamma)
+	q.z.Sub(q.z, delta)
+
+	beta.Add(beta, beta)
+	beta.Add(beta, beta)
+	beta.Sub(beta, q.x)
+	q.y.Mul(alpha, beta)
+
+	gamma.Square(gamma)
+	gamma.Add(gamma, gamma)
+	gamma.Add(gamma, gamma)
+	gamma.Add(gamma, gamma)
+
+	q.y.Sub(q.y, gamma)
+
+	return q
+}
+
+func (curve p521Curve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) {
+	B := curve.jacobianFromAffine(Bx, By)
+	p, t := &p521Point{
+		x: new(fiat.P521Element),
+		y: new(fiat.P521Element),
+		z: new(fiat.P521Element),
+	}, &p521Point{
+		x: new(fiat.P521Element),
+		y: new(fiat.P521Element),
+		z: new(fiat.P521Element),
+	}
+
+	for _, byte := range scalar {
+		for bitNum := 0; bitNum < 8; bitNum++ {
+			p.doubleJacobian(p)
+			bit := (byte >> (7 - bitNum)) & 1
+			t.addJacobian(p, B)
+			p.x.Select(t.x, p.x, int(bit))
+			p.y.Select(t.y, p.y, int(bit))
+			p.z.Select(t.z, p.z, int(bit))
+		}
+	}
+
+	return curve.affineFromJacobian(p)
+}
+
+func (curve p521Curve) ScalarBaseMult(k []byte) (*big.Int, *big.Int) {
+	return curve.ScalarMult(curve.Gx, curve.Gy, k)
+}
diff --git a/src/crypto/md5/md5block_ppc64x.s b/src/crypto/md5/md5block_ppc64x.s
index e1f859e3376..8c28ec2473c 100644
--- a/src/crypto/md5/md5block_ppc64x.s
+++ b/src/crypto/md5/md5block_ppc64x.s
@@ -10,6 +10,7 @@
 // Licence: I hereby disclaim the copyright on this code and place it
 // in the public domain.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/crypto/sha256/sha256.go b/src/crypto/sha256/sha256.go
index 8b54a427d7d..465d00e0e68 100644
--- a/src/crypto/sha256/sha256.go
+++ b/src/crypto/sha256/sha256.go
@@ -276,7 +276,7 @@ func Sum256(data []byte) [Size]byte {
 }
 
 // Sum224 returns the SHA224 checksum of the data.
-func Sum224(data []byte) (sum224 [Size224]byte) {
+func Sum224(data []byte) [Size224]byte {
 	if boring.Enabled {
 		h := New224()
 		h.Write(data)
@@ -289,6 +289,6 @@ func Sum224(data []byte) (sum224 [Size224]byte) {
 	d.Reset()
 	d.Write(data)
 	sum := d.checkSum()
-	copy(sum224[:], sum[:Size224])
-	return
+	ap := (*[Size224]byte)(sum[:])
+	return *ap
 }
diff --git a/src/crypto/sha512/sha512.go b/src/crypto/sha512/sha512.go
index 1a2cef317c3..1285cca7ee6 100644
--- a/src/crypto/sha512/sha512.go
+++ b/src/crypto/sha512/sha512.go
@@ -358,7 +358,7 @@ func Sum512(data []byte) [Size]byte {
 }
 
 // Sum384 returns the SHA384 checksum of the data.
-func Sum384(data []byte) (sum384 [Size384]byte) {
+func Sum384(data []byte) [Size384]byte {
 	if boring.Enabled {
 		h := New384()
 		h.Write(data)
@@ -370,26 +370,26 @@ func Sum384(data []byte) (sum384 [Size384]byte) {
 	d.Reset()
 	d.Write(data)
 	sum := d.checkSum()
-	copy(sum384[:], sum[:Size384])
-	return
+	ap := (*[Size384]byte)(sum[:])
+	return *ap
 }
 
 // Sum512_224 returns the Sum512/224 checksum of the data.
-func Sum512_224(data []byte) (sum224 [Size224]byte) {
+func Sum512_224(data []byte) [Size224]byte {
 	d := digest{function: crypto.SHA512_224}
 	d.Reset()
 	d.Write(data)
 	sum := d.checkSum()
-	copy(sum224[:], sum[:Size224])
-	return
+	ap := (*[Size224]byte)(sum[:])
+	return *ap
 }
 
 // Sum512_256 returns the Sum512/256 checksum of the data.
-func Sum512_256(data []byte) (sum256 [Size256]byte) {
+func Sum512_256(data []byte) [Size256]byte {
 	d := digest{function: crypto.SHA512_256}
 	d.Reset()
 	d.Write(data)
 	sum := d.checkSum()
-	copy(sum256[:], sum[:Size256])
-	return
+	ap := (*[Size256]byte)(sum[:])
+	return *ap
 }
diff --git a/src/crypto/tls/common.go b/src/crypto/tls/common.go
index ca93d4341d5..3e24d746bcf 100644
--- a/src/crypto/tls/common.go
+++ b/src/crypto/tls/common.go
@@ -619,7 +619,7 @@ type Config struct {
 	// protocol will be one from this list, and the connection will fail
 	// if there is no mutually supported protocol. If NextProtos is empty
 	// or the peer doesn't support ALPN, the connection will succeed and
-	// ConnectionState.NegotiatedProtocol will be empty."
+	// ConnectionState.NegotiatedProtocol will be empty.
 	NextProtos []string
 
 	// ServerName is used to verify the hostname on the returned
diff --git a/src/crypto/tls/handshake_client.go b/src/crypto/tls/handshake_client.go
index 9582a7f8675..cd1b3b1d126 100644
--- a/src/crypto/tls/handshake_client.go
+++ b/src/crypto/tls/handshake_client.go
@@ -714,17 +714,11 @@ func (hs *clientHandshakeState) processServerHello() (bool, error) {
 		}
 	}
 
-	if hs.serverHello.alpnProtocol != "" {
-		if len(hs.hello.alpnProtocols) == 0 {
-			c.sendAlert(alertUnsupportedExtension)
-			return false, errors.New("tls: server advertised unrequested ALPN extension")
-		}
-		if mutualProtocol([]string{hs.serverHello.alpnProtocol}, hs.hello.alpnProtocols) == "" {
-			c.sendAlert(alertUnsupportedExtension)
-			return false, errors.New("tls: server selected unadvertised ALPN protocol")
-		}
-		c.clientProtocol = hs.serverHello.alpnProtocol
+	if err := checkALPN(hs.hello.alpnProtocols, hs.serverHello.alpnProtocol); err != nil {
+		c.sendAlert(alertUnsupportedExtension)
+		return false, err
 	}
+	c.clientProtocol = hs.serverHello.alpnProtocol
 
 	c.scts = hs.serverHello.scts
 
@@ -756,6 +750,23 @@ func (hs *clientHandshakeState) processServerHello() (bool, error) {
 	return true, nil
 }
 
+// checkALPN ensure that the server's choice of ALPN protocol is compatible with
+// the protocols that we advertised in the Client Hello.
+func checkALPN(clientProtos []string, serverProto string) error {
+	if serverProto == "" {
+		return nil
+	}
+	if len(clientProtos) == 0 {
+		return errors.New("tls: server advertised unrequested ALPN extension")
+	}
+	for _, proto := range clientProtos {
+		if proto == serverProto {
+			return nil
+		}
+	}
+	return errors.New("tls: server selected unadvertised ALPN protocol")
+}
+
 func (hs *clientHandshakeState) readFinished(out []byte) error {
 	c := hs.c
 
@@ -984,19 +995,6 @@ func clientSessionCacheKey(serverAddr net.Addr, config *Config) string {
 	return serverAddr.String()
 }
 
-// mutualProtocol finds the mutual ALPN protocol given list of possible
-// protocols and a list of the preference order.
-func mutualProtocol(protos, preferenceProtos []string) string {
-	for _, s := range preferenceProtos {
-		for _, c := range protos {
-			if s == c {
-				return s
-			}
-		}
-	}
-	return ""
-}
-
 // hostnameInSNI converts name into an appropriate hostname for SNI.
 // Literal IP addresses and absolute FQDNs are not permitted as SNI values.
 // See RFC 6066, Section 3.
diff --git a/src/crypto/tls/handshake_client_tls13.go b/src/crypto/tls/handshake_client_tls13.go
index 1405d6811f3..c7989867f56 100644
--- a/src/crypto/tls/handshake_client_tls13.go
+++ b/src/crypto/tls/handshake_client_tls13.go
@@ -400,17 +400,11 @@ func (hs *clientHandshakeStateTLS13) readServerParameters() error {
 	}
 	hs.transcript.Write(encryptedExtensions.marshal())
 
-	if encryptedExtensions.alpnProtocol != "" {
-		if len(hs.hello.alpnProtocols) == 0 {
-			c.sendAlert(alertUnsupportedExtension)
-			return errors.New("tls: server advertised unrequested ALPN extension")
-		}
-		if mutualProtocol([]string{encryptedExtensions.alpnProtocol}, hs.hello.alpnProtocols) == "" {
-			c.sendAlert(alertUnsupportedExtension)
-			return errors.New("tls: server selected unadvertised ALPN protocol")
-		}
-		c.clientProtocol = encryptedExtensions.alpnProtocol
+	if err := checkALPN(hs.hello.alpnProtocols, encryptedExtensions.alpnProtocol); err != nil {
+		c.sendAlert(alertUnsupportedExtension)
+		return err
 	}
+	c.clientProtocol = encryptedExtensions.alpnProtocol
 
 	return nil
 }
diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go
index 85afad06715..497e196a856 100644
--- a/src/crypto/tls/handshake_server.go
+++ b/src/crypto/tls/handshake_server.go
@@ -217,15 +217,13 @@ func (hs *serverHandshakeState) processClientHello() error {
 		c.serverName = hs.clientHello.serverName
 	}
 
-	if len(c.config.NextProtos) > 0 && len(hs.clientHello.alpnProtocols) > 0 {
-		selectedProto := mutualProtocol(hs.clientHello.alpnProtocols, c.config.NextProtos)
-		if selectedProto == "" {
-			c.sendAlert(alertNoApplicationProtocol)
-			return fmt.Errorf("tls: client requested unsupported application protocols (%s)", hs.clientHello.alpnProtocols)
-		}
-		hs.hello.alpnProtocol = selectedProto
-		c.clientProtocol = selectedProto
+	selectedProto, err := negotiateALPN(c.config.NextProtos, hs.clientHello.alpnProtocols)
+	if err != nil {
+		c.sendAlert(alertNoApplicationProtocol)
+		return err
 	}
+	hs.hello.alpnProtocol = selectedProto
+	c.clientProtocol = selectedProto
 
 	hs.cert, err = c.config.getCertificate(clientHelloInfo(hs.ctx, c, hs.clientHello))
 	if err != nil {
@@ -277,6 +275,34 @@ func (hs *serverHandshakeState) processClientHello() error {
 	return nil
 }
 
+// negotiateALPN picks a shared ALPN protocol that both sides support in server
+// preference order. If ALPN is not configured or the peer doesn't support it,
+// it returns "" and no error.
+func negotiateALPN(serverProtos, clientProtos []string) (string, error) {
+	if len(serverProtos) == 0 || len(clientProtos) == 0 {
+		return "", nil
+	}
+	var http11fallback bool
+	for _, s := range serverProtos {
+		for _, c := range clientProtos {
+			if s == c {
+				return s, nil
+			}
+			if s == "h2" && c == "http/1.1" {
+				http11fallback = true
+			}
+		}
+	}
+	// As a special case, let http/1.1 clients connect to h2 servers as if they
+	// didn't support ALPN. We used not to enforce protocol overlap, so over
+	// time a number of HTTP servers were configured with only "h2", but
+	// expected to accept connections from "http/1.1" clients. See Issue 46310.
+	if http11fallback {
+		return "", nil
+	}
+	return "", fmt.Errorf("tls: client requested unsupported application protocols (%s)", clientProtos)
+}
+
 // supportsECDHE returns whether ECDHE key exchanges can be used with this
 // pre-TLS 1.3 client.
 func supportsECDHE(c *Config, supportedCurves []CurveID, supportedPoints []uint8) bool {
diff --git a/src/crypto/tls/handshake_server_test.go b/src/crypto/tls/handshake_server_test.go
index 4483838045c..f61b4c88efa 100644
--- a/src/crypto/tls/handshake_server_test.go
+++ b/src/crypto/tls/handshake_server_test.go
@@ -949,6 +949,27 @@ func TestHandshakeServerALPNNotConfigured(t *testing.T) {
 	runServerTestTLS13(t, test)
 }
 
+func TestHandshakeServerALPNFallback(t *testing.T) {
+	config := testConfig.Clone()
+	config.NextProtos = []string{"proto1", "h2", "proto2"}
+
+	test := &serverTest{
+		name: "ALPN-Fallback",
+		// Note that this needs OpenSSL 1.0.2 because that is the first
+		// version that supports the -alpn flag.
+		command: []string{"openssl", "s_client", "-alpn", "proto3,http/1.1,proto4", "-cipher", "ECDHE-RSA-CHACHA20-POLY1305", "-ciphersuites", "TLS_CHACHA20_POLY1305_SHA256"},
+		config:  config,
+		validate: func(state ConnectionState) error {
+			if state.NegotiatedProtocol != "" {
+				return fmt.Errorf("Got protocol %q, wanted nothing", state.NegotiatedProtocol)
+			}
+			return nil
+		},
+	}
+	runServerTestTLS12(t, test)
+	runServerTestTLS13(t, test)
+}
+
 // TestHandshakeServerSNI involves a client sending an SNI extension of
 // "snitest.com", which happens to match the CN of testSNICertificate. The test
 // verifies that the server correctly selects that certificate.
diff --git a/src/crypto/tls/handshake_server_tls13.go b/src/crypto/tls/handshake_server_tls13.go
index 742fdc3c05c..109ff7a01d4 100644
--- a/src/crypto/tls/handshake_server_tls13.go
+++ b/src/crypto/tls/handshake_server_tls13.go
@@ -11,7 +11,6 @@ import (
 	"crypto/hmac"
 	"crypto/rsa"
 	"errors"
-	"fmt"
 	"hash"
 	"io"
 	"sync/atomic"
@@ -555,15 +554,13 @@ func (hs *serverHandshakeStateTLS13) sendServerParameters() error {
 
 	encryptedExtensions := new(encryptedExtensionsMsg)
 
-	if len(c.config.NextProtos) > 0 && len(hs.clientHello.alpnProtocols) > 0 {
-		selectedProto := mutualProtocol(hs.clientHello.alpnProtocols, c.config.NextProtos)
-		if selectedProto == "" {
-			c.sendAlert(alertNoApplicationProtocol)
-			return fmt.Errorf("tls: client requested unsupported application protocols (%s)", hs.clientHello.alpnProtocols)
-		}
-		encryptedExtensions.alpnProtocol = selectedProto
-		c.clientProtocol = selectedProto
+	selectedProto, err := negotiateALPN(c.config.NextProtos, hs.clientHello.alpnProtocols)
+	if err != nil {
+		c.sendAlert(alertNoApplicationProtocol)
+		return err
 	}
+	encryptedExtensions.alpnProtocol = selectedProto
+	c.clientProtocol = selectedProto
 
 	hs.transcript.Write(encryptedExtensions.marshal())
 	if _, err := c.writeRecord(recordTypeHandshake, encryptedExtensions.marshal()); err != nil {
diff --git a/src/crypto/tls/key_agreement.go b/src/crypto/tls/key_agreement.go
index 8cfbd734f15..c28a64f3a8b 100644
--- a/src/crypto/tls/key_agreement.go
+++ b/src/crypto/tls/key_agreement.go
@@ -86,7 +86,11 @@ func (ka rsaKeyAgreement) generateClientKeyExchange(config *Config, clientHello
 		return nil, nil, err
 	}
 
-	encrypted, err := rsa.EncryptPKCS1v15(config.rand(), cert.PublicKey.(*rsa.PublicKey), preMasterSecret)
+	rsaKey, ok := cert.PublicKey.(*rsa.PublicKey)
+	if !ok {
+		return nil, nil, errors.New("tls: server certificate contains incorrect key type for selected ciphersuite")
+	}
+	encrypted, err := rsa.EncryptPKCS1v15(config.rand(), rsaKey, preMasterSecret)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/src/crypto/tls/testdata/Server-TLSv12-ALPN-Fallback b/src/crypto/tls/testdata/Server-TLSv12-ALPN-Fallback
new file mode 100644
index 00000000000..4fadf390623
--- /dev/null
+++ b/src/crypto/tls/testdata/Server-TLSv12-ALPN-Fallback
@@ -0,0 +1,91 @@
+>>> Flow 1 (client to server)
+00000000  16 03 01 00 a6 01 00 00  a2 03 03 b5 c9 ab 32 7f  |..............2.|
+00000010  e1 af 3f f2 ac 2a 11 dd  33 f9 b5 21 88 0d e4 29  |..?..*..3..!...)|
+00000020  e2 47 49 dc c7 31 a8 a5  25 81 0c 00 00 04 cc a8  |.GI..1..%.......|
+00000030  00 ff 01 00 00 75 00 0b  00 04 03 00 01 02 00 0a  |.....u..........|
+00000040  00 0c 00 0a 00 1d 00 17  00 1e 00 19 00 18 00 23  |...............#|
+00000050  00 00 00 10 00 19 00 17  06 70 72 6f 74 6f 33 08  |.........proto3.|
+00000060  68 74 74 70 2f 31 2e 31  06 70 72 6f 74 6f 34 00  |http/1.1.proto4.|
+00000070  16 00 00 00 17 00 00 00  0d 00 30 00 2e 04 03 05  |..........0.....|
+00000080  03 06 03 08 07 08 08 08  09 08 0a 08 0b 08 04 08  |................|
+00000090  05 08 06 04 01 05 01 06  01 03 03 02 03 03 01 02  |................|
+000000a0  01 03 02 02 02 04 02 05  02 06 02                 |...........|
+>>> Flow 2 (server to client)
+00000000  16 03 03 00 3b 02 00 00  37 03 03 00 00 00 00 00  |....;...7.......|
+00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00000020  00 00 00 44 4f 57 4e 47  52 44 01 00 cc a8 00 00  |...DOWNGRD......|
+00000030  0f 00 23 00 00 ff 01 00  01 00 00 0b 00 02 01 00  |..#.............|
+00000040  16 03 03 02 59 0b 00 02  55 00 02 52 00 02 4f 30  |....Y...U..R..O0|
+00000050  82 02 4b 30 82 01 b4 a0  03 02 01 02 02 09 00 e8  |..K0............|
+00000060  f0 9d 3f e2 5b ea a6 30  0d 06 09 2a 86 48 86 f7  |..?.[..0...*.H..|
+00000070  0d 01 01 0b 05 00 30 1f  31 0b 30 09 06 03 55 04  |......0.1.0...U.|
+00000080  0a 13 02 47 6f 31 10 30  0e 06 03 55 04 03 13 07  |...Go1.0...U....|
+00000090  47 6f 20 52 6f 6f 74 30  1e 17 0d 31 36 30 31 30  |Go Root0...16010|
+000000a0  31 30 30 30 30 30 30 5a  17 0d 32 35 30 31 30 31  |1000000Z..250101|
+000000b0  30 30 30 30 30 30 5a 30  1a 31 0b 30 09 06 03 55  |000000Z0.1.0...U|
+000000c0  04 0a 13 02 47 6f 31 0b  30 09 06 03 55 04 03 13  |....Go1.0...U...|
+000000d0  02 47 6f 30 81 9f 30 0d  06 09 2a 86 48 86 f7 0d  |.Go0..0...*.H...|
+000000e0  01 01 01 05 00 03 81 8d  00 30 81 89 02 81 81 00  |.........0......|
+000000f0  db 46 7d 93 2e 12 27 06  48 bc 06 28 21 ab 7e c4  |.F}...'.H..(!.~.|
+00000100  b6 a2 5d fe 1e 52 45 88  7a 36 47 a5 08 0d 92 42  |..]..RE.z6G....B|
+00000110  5b c2 81 c0 be 97 79 98  40 fb 4f 6d 14 fd 2b 13  |[.....y.@.Om..+.|
+00000120  8b c2 a5 2e 67 d8 d4 09  9e d6 22 38 b7 4a 0b 74  |....g....."8.J.t|
+00000130  73 2b c2 34 f1 d1 93 e5  96 d9 74 7b f3 58 9f 6c  |s+.4......t{.X.l|
+00000140  61 3c c0 b0 41 d4 d9 2b  2b 24 23 77 5b 1c 3b bd  |a<..A..++$#w[.;.|
+00000150  75 5d ce 20 54 cf a1 63  87 1d 1e 24 c4 f3 1d 1a  |u]. T..c...$....|
+00000160  50 8b aa b6 14 43 ed 97  a7 75 62 f4 14 c8 52 d7  |P....C...ub...R.|
+00000170  02 03 01 00 01 a3 81 93  30 81 90 30 0e 06 03 55  |........0..0...U|
+00000180  1d 0f 01 01 ff 04 04 03  02 05 a0 30 1d 06 03 55  |...........0...U|
+00000190  1d 25 04 16 30 14 06 08  2b 06 01 05 05 07 03 01  |.%..0...+.......|
+000001a0  06 08 2b 06 01 05 05 07  03 02 30 0c 06 03 55 1d  |..+.......0...U.|
+000001b0  13 01 01 ff 04 02 30 00  30 19 06 03 55 1d 0e 04  |......0.0...U...|
+000001c0  12 04 10 9f 91 16 1f 43  43 3e 49 a6 de 6d b6 80  |.......CC>I..m..|
+000001d0  d7 9f 60 30 1b 06 03 55  1d 23 04 14 30 12 80 10  |..`0...U.#..0...|
+000001e0  48 13 49 4d 13 7e 16 31  bb a3 01 d5 ac ab 6e 7b  |H.IM.~.1......n{|
+000001f0  30 19 06 03 55 1d 11 04  12 30 10 82 0e 65 78 61  |0...U....0...exa|
+00000200  6d 70 6c 65 2e 67 6f 6c  61 6e 67 30 0d 06 09 2a  |mple.golang0...*|
+00000210  86 48 86 f7 0d 01 01 0b  05 00 03 81 81 00 9d 30  |.H.............0|
+00000220  cc 40 2b 5b 50 a0 61 cb  ba e5 53 58 e1 ed 83 28  |.@+[P.a...SX...(|
+00000230  a9 58 1a a9 38 a4 95 a1  ac 31 5a 1a 84 66 3d 43  |.X..8....1Z..f=C|
+00000240  d3 2d d9 0b f2 97 df d3  20 64 38 92 24 3a 00 bc  |.-...... d8.$:..|
+00000250  cf 9c 7d b7 40 20 01 5f  aa d3 16 61 09 a2 76 fd  |..}.@ ._...a..v.|
+00000260  13 c3 cc e1 0c 5c ee b1  87 82 f1 6c 04 ed 73 bb  |.....\.....l..s.|
+00000270  b3 43 77 8d 0c 1c f1 0f  a1 d8 40 83 61 c9 4c 72  |.Cw.......@.a.Lr|
+00000280  2b 9d ae db 46 06 06 4d  f4 c1 b3 3e c0 d1 bd 42  |+...F..M...>...B|
+00000290  d4 db fe 3d 13 60 84 5c  21 d3 3b e9 fa e7 16 03  |...=.`.\!.;.....|
+000002a0  03 00 ac 0c 00 00 a8 03  00 1d 20 2f e5 7d a3 47  |.......... /.}.G|
+000002b0  cd 62 43 15 28 da ac 5f  bb 29 07 30 ff f6 84 af  |.bC.(.._.).0....|
+000002c0  c4 cf c2 ed 90 99 5f 58  cb 3b 74 08 04 00 80 5f  |......_X.;t...._|
+000002d0  37 27 84 58 1e ea 1e 40  1b de a9 8f 04 d4 94 64  |7'.X...@.......d|
+000002e0  4e 27 c7 f1 b3 30 d0 53  f5 3d 57 50 d2 17 97 c8  |N'...0.S.=WP....|
+000002f0  3d 61 af a6 21 ab 1c 34  47 70 f8 b1 3b 9c 06 86  |=a..!..4Gp..;...|
+00000300  87 00 e2 13 50 83 91 ad  bc 84 bd b4 7b f3 4b ed  |....P.......{.K.|
+00000310  ca 81 0c 94 37 a8 ec 67  ca 9c f3 00 f6 af c2 92  |....7..g........|
+00000320  c4 8c 78 07 18 0e 43 24  1b 98 16 50 5c 2b 75 0e  |..x...C$...P\+u.|
+00000330  40 66 dc 40 cd 10 1a 51  25 f3 96 25 1a 3e 70 af  |@f.@...Q%..%.>p.|
+00000340  16 24 d0 1c 0e 33 f9 c1  74 cf b7 e2 28 ac 60 16  |.$...3..t...(.`.|
+00000350  03 03 00 04 0e 00 00 00                           |........|
+>>> Flow 3 (client to server)
+00000000  16 03 03 00 25 10 00 00  21 20 30 f2 bb f7 a7 ac  |....%...! 0.....|
+00000010  23 20 22 ee 73 0d 49 9c  b3 7b c1 9a db 2c 85 f3  |# ".s.I..{...,..|
+00000020  c0 82 31 60 bd 8b 14 4e  73 43 14 03 03 00 01 01  |..1`...NsC......|
+00000030  16 03 03 00 20 09 8d c7  86 ee cc f4 c7 36 a3 49  |.... ........6.I|
+00000040  d3 f7 a1 4a 68 a2 1e b4  fc cc a2 15 cb 01 92 d8  |...Jh...........|
+00000050  72 b0 d1 6f eb                                    |r..o.|
+>>> Flow 4 (server to client)
+00000000  16 03 03 00 8b 04 00 00  87 00 00 00 00 00 81 50  |...............P|
+00000010  46 ad c1 db a8 38 86 7b  2b bb fd d0 c3 42 3e 00  |F....8.{+....B>.|
+00000020  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 94  |................|
+00000030  6f e0 18 83 51 ed 14 ef  68 ca 42 c5 4c a2 ac 05  |o...Q...h.B.L...|
+00000040  9c 69 69 99 08 9f de a4  d4 e7 37 ab 14 38 4c 47  |.ii.......7..8LG|
+00000050  70 f0 97 1d db 2d 0a 14  c2 1e f0 16 9f 6d 37 02  |p....-.......m7.|
+00000060  4b f1 16 be 98 3f df 74  83 7c 19 85 61 49 38 16  |K....?.t.|..aI8.|
+00000070  ee 35 7a e2 3f 74 fe 8d  e3 07 93 a1 5e fa f2 02  |.5z.?t......^...|
+00000080  e5 c8 60 3f 11 83 8b 0e  32 52 f1 aa 52 b7 0a 89  |..`?....2R..R...|
+00000090  14 03 03 00 01 01 16 03  03 00 20 9e 65 15 cf 45  |.......... .e..E|
+000000a0  a5 03 69 c9 b1 d8 9e 92  a3 a2 b0 df 2e 62 b1 3a  |..i..........b.:|
+000000b0  17 78 cd e5 1d f3 51 42  7e 4e 25 17 03 03 00 1d  |.x....QB~N%.....|
+000000c0  d9 ae d0 fa b7 90 a9 2f  28 8d 1d 6f 54 1f c0 1e  |......./(..oT...|
+000000d0  4d ae b6 91 f0 e8 84 cf  86 11 22 25 ea 15 03 03  |M........."%....|
+000000e0  00 12 0e 71 f2 11 9e 9f  58 ad c0 d8 fc fa 34 bc  |...q....X.....4.|
+000000f0  02 5a 60 00                                       |.Z`.|
diff --git a/src/crypto/tls/testdata/Server-TLSv13-ALPN-Fallback b/src/crypto/tls/testdata/Server-TLSv13-ALPN-Fallback
new file mode 100644
index 00000000000..6203e6877cd
--- /dev/null
+++ b/src/crypto/tls/testdata/Server-TLSv13-ALPN-Fallback
@@ -0,0 +1,100 @@
+>>> Flow 1 (client to server)
+00000000  16 03 01 00 eb 01 00 00  e7 03 03 1c d3 8e 3b d9  |..............;.|
+00000010  fe 7d e7 f9 9f fa c6 51  c3 8c 1b dd dc 87 95 f4  |.}.....Q........|
+00000020  39 23 67 e4 d6 bd 94 93  fc 88 4e 20 c3 c0 e2 c1  |9#g.......N ....|
+00000030  3d 12 ec 4c 0a 3f 40 51  13 24 61 11 c0 5d 09 f9  |=..L.?@Q.$a..]..|
+00000040  08 d6 3e cd e7 b3 51 c3  06 8f b4 42 00 04 13 03  |..>...Q....B....|
+00000050  00 ff 01 00 00 9a 00 0b  00 04 03 00 01 02 00 0a  |................|
+00000060  00 0c 00 0a 00 1d 00 17  00 1e 00 19 00 18 00 23  |...............#|
+00000070  00 00 00 10 00 19 00 17  06 70 72 6f 74 6f 33 08  |.........proto3.|
+00000080  68 74 74 70 2f 31 2e 31  06 70 72 6f 74 6f 34 00  |http/1.1.proto4.|
+00000090  16 00 00 00 17 00 00 00  0d 00 1e 00 1c 04 03 05  |................|
+000000a0  03 06 03 08 07 08 08 08  09 08 0a 08 0b 08 04 08  |................|
+000000b0  05 08 06 04 01 05 01 06  01 00 2b 00 03 02 03 04  |..........+.....|
+000000c0  00 2d 00 02 01 01 00 33  00 26 00 24 00 1d 00 20  |.-.....3.&.$... |
+000000d0  f4 05 eb 4a 7a 73 20 18  74 aa 14 2a 0c 35 63 29  |...Jzs .t..*.5c)|
+000000e0  cb f2 ad d1 a2 3d bd 9d  02 b4 62 00 bc eb 10 58  |.....=....b....X|
+>>> Flow 2 (server to client)
+00000000  16 03 03 00 7a 02 00 00  76 03 03 00 00 00 00 00  |....z...v.......|
+00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00000020  00 00 00 00 00 00 00 00  00 00 00 20 c3 c0 e2 c1  |........... ....|
+00000030  3d 12 ec 4c 0a 3f 40 51  13 24 61 11 c0 5d 09 f9  |=..L.?@Q.$a..]..|
+00000040  08 d6 3e cd e7 b3 51 c3  06 8f b4 42 13 03 00 00  |..>...Q....B....|
+00000050  2e 00 2b 00 02 03 04 00  33 00 24 00 1d 00 20 2f  |..+.....3.$... /|
+00000060  e5 7d a3 47 cd 62 43 15  28 da ac 5f bb 29 07 30  |.}.G.bC.(.._.).0|
+00000070  ff f6 84 af c4 cf c2 ed  90 99 5f 58 cb 3b 74 14  |.........._X.;t.|
+00000080  03 03 00 01 01 17 03 03  00 17 fb 75 d8 5c 50 35  |...........u.\P5|
+00000090  55 82 ba 65 1e 63 73 b8  c1 e9 d7 f5 28 68 3c c1  |U..e.cs.....(h<.|
+000000a0  5d 17 03 03 02 6d 56 c9  a9 09 73 6a bc fd 1a 3c  |]....mV...sj...<|
+000000b0  6a f8 3e 32 99 83 e8 f6  01 9e 5e 30 e8 53 7f 72  |j.>2......^0.S.r|
+000000c0  fd 86 72 a8 9e 47 25 67  c1 f1 9a 03 c0 9d 6f 9d  |..r..G%g......o.|
+000000d0  bd ed 29 30 8f 3c 01 ce  49 bb 5f dd 58 9a ae 80  |..)0.<..I._.X...|
+000000e0  5c 2d 81 fc ea 7b 03 03  3d 5d bb 92 23 73 67 89  |\-...{..=]..#sg.|
+000000f0  2e f0 ec 08 20 8a 36 eb  43 a6 a1 68 d0 39 95 37  |.... .6.C..h.9.7|
+00000100  6b 15 a9 0e 46 20 92 51  9c 04 bf 3b 07 97 84 cb  |k...F .Q...;....|
+00000110  1f 30 38 37 2e ff e7 0f  f5 14 93 5a 84 f1 f7 10  |.087.......Z....|
+00000120  c2 a5 0d bb 97 96 ef 4a  e0 13 c0 63 72 2b 60 f3  |.......J...cr+`.|
+00000130  59 b5 57 aa 5f d1 da a9  0e dd 9c dd c2 cb 61 fe  |Y.W._.........a.|
+00000140  e2 69 8e db 5d 70 6c 3a  33 e0 9e db 9a 31 26 6a  |.i..]pl:3....1&j|
+00000150  2b 9e 19 8e bb 5d 06 48  ea c0 a1 c6 11 24 fb c4  |+....].H.....$..|
+00000160  ce ae 48 54 64 81 d1 84  38 a6 e0 7a 7b 74 2b bc  |..HTd...8..z{t+.|
+00000170  ce 07 8b b6 04 1f 5b 4c  36 29 68 0c 8c c7 32 15  |......[L6)h...2.|
+00000180  93 e0 10 52 c2 27 23 96  c5 0c 9c e9 e2 a9 08 7d  |...R.'#........}|
+00000190  25 68 65 f5 4e 44 eb a9  85 78 13 e1 0d 86 5e dc  |%he.ND...x....^.|
+000001a0  fd e5 c6 dd 65 46 8e 2f  32 82 83 0b dd 67 f8 42  |....eF./2....g.B|
+000001b0  65 87 3b 08 fe b1 f5 12  e9 74 21 04 12 6d 75 35  |e.;......t!..mu5|
+000001c0  b2 eb 93 95 72 10 fa 56  96 77 c3 0c 17 8c 9e f6  |....r..V.w......|
+000001d0  77 19 28 37 96 3e 73 98  f4 d2 91 4f 40 db 76 56  |w.(7.>s....O@.vV|
+000001e0  ce b5 a8 7a b8 86 d0 9a  ba b5 8b 40 c2 63 e1 cf  |...z.......@.c..|
+000001f0  49 29 2c 5d 1a 9b 8b 56  cb 93 ca 2c c0 d0 15 b7  |I),]...V...,....|
+00000200  8a f1 6a d5 0a a8 81 57  b1 6e 10 cd a5 ff b1 4d  |..j....W.n.....M|
+00000210  47 c6 9b 35 f1 5f 83 91  22 f6 88 68 65 b3 b9 c9  |G..5._.."..he...|
+00000220  02 dc 4b f7 13 39 06 e6  3a ec 94 ef 51 15 05 72  |..K..9..:...Q..r|
+00000230  1d f4 9d 3b da ca 8d 2c  64 be 9b 45 99 2c 63 cc  |...;...,d..E.,c.|
+00000240  22 b3 8b 93 ad f6 2c f0  d2 d9 11 3f 5b c0 40 fa  |".....,....?[.@.|
+00000250  90 6e a0 76 b2 43 b9 4c  72 c4 24 28 a2 bf 56 d6  |.n.v.C.Lr.$(..V.|
+00000260  d2 a7 2a d1 8c 5e 1d eb  f8 be d0 43 da 7a c7 88  |..*..^.....C.z..|
+00000270  61 67 a2 69 85 23 43 3e  d4 88 f2 33 c3 5b 38 0a  |ag.i.#C>...3.[8.|
+00000280  1e de 28 3b 3b 19 de 95  2f 84 c0 37 88 80 59 2f  |..(;;.../..7..Y/|
+00000290  a6 ee 93 1a 69 08 c3 df  7c cf da c3 9b 96 70 d9  |....i...|.....p.|
+000002a0  60 c5 e9 0f 42 f6 1a f2  58 5e f2 32 61 6a b2 a3  |`...B...X^.2aj..|
+000002b0  1f 97 fa 08 6c 3f 4b 83  1f 04 66 80 8a 26 3a 7f  |....l?K...f..&:.|
+000002c0  24 30 ec 10 ae 7d 19 ff  39 91 ca 97 4e ed 0a d7  |$0...}..9...N...|
+000002d0  64 3b 6b 50 29 33 0d b2  10 bc 83 63 3c fb 9a 82  |d;kP)3.....c<...|
+000002e0  3b 7f bc 04 40 f1 33 64  4a 80 cd 01 f9 f4 c6 89  |;...@.3dJ.......|
+000002f0  65 27 25 f9 cf 4f 7e c8  6e d9 0e ec 47 4a 51 29  |e'%..O~.n...GJQ)|
+00000300  2f be 34 50 bd 9b d2 d8  b7 ea bb 0b a1 e0 20 1b  |/.4P.......... .|
+00000310  02 9c f2 17 03 03 00 99  61 dc 0b 3a 30 de 39 f6  |........a..:0.9.|
+00000320  f3 db f8 6c 3b fa 4e 1e  7e 62 a5 ae 73 ba e1 41  |...l;.N.~b..s..A|
+00000330  58 77 2a c1 7a 0c 50 bb  0c 57 b4 c4 25 bf 2f 9f  |Xw*.z.P..W..%./.|
+00000340  38 91 e2 65 22 9d ca ac  18 58 7e 81 2d fd 74 24  |8..e"....X~.-.t$|
+00000350  28 69 76 11 df 9d 23 b8  be ae 8b e0 93 8e 5d df  |(iv...#.......].|
+00000360  0a 64 d0 b7 02 68 aa 86  01 0d 55 11 3b 76 70 c6  |.d...h....U.;vp.|
+00000370  83 0c 5e 0a e3 37 a5 8b  ad 25 50 b9 e8 5c 6b 04  |..^..7...%P..\k.|
+00000380  b4 51 ec 9c d3 fa c6 b7  9c f0 46 aa 73 da 3c 0d  |.Q........F.s.<.|
+00000390  d3 bd 32 81 d4 d2 f1 1a  b0 92 f3 73 3e 54 2b 05  |..2........s>T+.|
+000003a0  92 24 34 75 df d6 18 a0  6a 82 95 4c 9b fc 7e b6  |.$4u....j..L..~.|
+000003b0  8e 17 03 03 00 35 8f 34  0e 3b 91 d8 e7 74 24 71  |.....5.4.;...t$q|
+000003c0  0e 7b f3 12 bb 76 2f 31  12 17 b8 9e 24 ce f9 2f  |.{...v/1....$../|
+000003d0  3f 5d f2 13 4b 2e 9b 1e  c4 78 03 a6 c8 07 11 a3  |?]..K....x......|
+000003e0  98 79 61 6e 4f 44 6e 18  ee c4 9b 17 03 03 00 93  |.yanODn.........|
+000003f0  64 dd 52 a9 d9 51 63 6a  a0 a3 c2 75 6b 5d 1d 54  |d.R..Qcj...uk].T|
+00000400  ce d4 53 7e 14 8e d9 26  93 28 78 65 16 1b 95 77  |..S~...&.(xe...w|
+00000410  68 0a 46 f1 82 36 bb 8a  fa 0d df 54 8c 3d 83 e0  |h.F..6.....T.=..|
+00000420  d7 de 2d 96 e9 c4 d7 22  d3 97 8e ae 90 f8 fc e6  |..-...."........|
+00000430  a6 4b 78 98 4c c5 28 87  91 46 fa f4 1c 8d 0e ec  |.Kx.L.(..F......|
+00000440  0d 71 40 9a 04 49 b4 e8  5b 62 6f cd 16 c1 d5 fb  |.q@..I..[bo.....|
+00000450  73 2a 96 8f e5 a2 f4 11  1e df 2d 40 45 6b d5 a9  |s*........-@Ek..|
+00000460  e4 e3 f7 93 fc fa d7 20  af d5 f7 b4 0e 09 ad d5  |....... ........|
+00000470  26 87 b8 6c e2 20 95 fb  c0 70 3e 38 be b7 b1 9f  |&..l. ...p>8....|
+00000480  70 da c1                                          |p..|
+>>> Flow 3 (client to server)
+00000000  14 03 03 00 01 01 17 03  03 00 35 29 d2 b9 bb 9b  |..........5)....|
+00000010  de 6c 5d 22 23 c1 fe 99  4c c5 33 bf fd 70 36 6b  |.l]"#...L.3..p6k|
+00000020  f1 a5 92 e8 bf 7c 3d 6e  ef 6a 44 73 bc cb 27 1c  |.....|=n.jDs..'.|
+00000030  09 5d bf 99 4c 19 24 c3  3b 30 91 b5 e3 b6 63 45  |.]..L.$.;0....cE|
+>>> Flow 4 (server to client)
+00000000  17 03 03 00 1e 52 55 85  7c b8 87 dd c7 b2 d9 5b  |.....RU.|......[|
+00000010  18 1d bb ac bf b6 ab 76  82 be 64 0e b2 7b 2c 0f  |.......v..d..{,.|
+00000020  aa 17 92 17 03 03 00 13  79 0a 60 b1 46 20 33 74  |........y.`.F 3t|
+00000030  ed 12 a0 23 de 68 88 fc  6f dd 8e                 |...#.h..o..|
diff --git a/src/crypto/x509/internal/macos/corefoundation.s b/src/crypto/x509/internal/macos/corefoundation.s
index a9efaa299d8..cda2336c9d1 100644
--- a/src/crypto/x509/internal/macos/corefoundation.s
+++ b/src/crypto/x509/internal/macos/corefoundation.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && !ios
 // +build darwin,!ios
 
 #include "textflag.h"
diff --git a/src/crypto/x509/internal/macos/security.s b/src/crypto/x509/internal/macos/security.s
index 09ce5c6c769..0038f25b277 100644
--- a/src/crypto/x509/internal/macos/security.s
+++ b/src/crypto/x509/internal/macos/security.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && !ios
 // +build darwin,!ios
 
 #include "textflag.h"
diff --git a/src/crypto/x509/parser.go b/src/crypto/x509/parser.go
index 578227ab8eb..f085162a4e8 100644
--- a/src/crypto/x509/parser.go
+++ b/src/crypto/x509/parser.go
@@ -24,7 +24,6 @@ import (
 	"unicode/utf8"
 
 	"golang.org/x/crypto/cryptobyte"
-	cbasn1 "golang.org/x/crypto/cryptobyte/asn1"
 	cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1"
 )
 
@@ -55,23 +54,23 @@ func isPrintable(b byte) bool {
 // UTF8String, BMPString, and IA5String. This is mostly copied from the
 // respective encoding/asn1.parse... methods, rather than just increasing
 // the API surface of that package.
-func parseASN1String(tag cbasn1.Tag, value []byte) (string, error) {
+func parseASN1String(tag cryptobyte_asn1.Tag, value []byte) (string, error) {
 	switch tag {
-	case cbasn1.T61String:
+	case cryptobyte_asn1.T61String:
 		return string(value), nil
-	case cbasn1.PrintableString:
+	case cryptobyte_asn1.PrintableString:
 		for _, b := range value {
 			if !isPrintable(b) {
 				return "", errors.New("invalid PrintableString")
 			}
 		}
 		return string(value), nil
-	case cbasn1.UTF8String:
+	case cryptobyte_asn1.UTF8String:
 		if !utf8.Valid(value) {
 			return "", errors.New("invalid UTF-8 string")
 		}
 		return string(value), nil
-	case cbasn1.Tag(asn1.TagBMPString):
+	case cryptobyte_asn1.Tag(asn1.TagBMPString):
 		if len(value)%2 != 0 {
 			return "", errors.New("invalid BMPString")
 		}
@@ -88,7 +87,7 @@ func parseASN1String(tag cbasn1.Tag, value []byte) (string, error) {
 		}
 
 		return string(utf16.Decode(s)), nil
-	case cbasn1.IA5String:
+	case cryptobyte_asn1.IA5String:
 		s := string(value)
 		if isIA5String(s) != nil {
 			return "", errors.New("invalid IA5String")
@@ -101,7 +100,7 @@ func parseASN1String(tag cbasn1.Tag, value []byte) (string, error) {
 // parseName parses a DER encoded Name as defined in RFC 5280. We may
 // want to export this function in the future for use in crypto/tls.
 func parseName(raw cryptobyte.String) (*pkix.RDNSequence, error) {
-	if !raw.ReadASN1(&raw, cbasn1.SEQUENCE) {
+	if !raw.ReadASN1(&raw, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: invalid RDNSequence")
 	}
 
@@ -109,12 +108,12 @@ func parseName(raw cryptobyte.String) (*pkix.RDNSequence, error) {
 	for !raw.Empty() {
 		var rdnSet pkix.RelativeDistinguishedNameSET
 		var set cryptobyte.String
-		if !raw.ReadASN1(&set, cbasn1.SET) {
+		if !raw.ReadASN1(&set, cryptobyte_asn1.SET) {
 			return nil, errors.New("x509: invalid RDNSequence")
 		}
 		for !set.Empty() {
 			var atav cryptobyte.String
-			if !set.ReadASN1(&atav, cbasn1.SEQUENCE) {
+			if !set.ReadASN1(&atav, cryptobyte_asn1.SEQUENCE) {
 				return nil, errors.New("x509: invalid RDNSequence: invalid attribute")
 			}
 			var attr pkix.AttributeTypeAndValue
@@ -122,7 +121,7 @@ func parseName(raw cryptobyte.String) (*pkix.RDNSequence, error) {
 				return nil, errors.New("x509: invalid RDNSequence: invalid attribute type")
 			}
 			var rawValue cryptobyte.String
-			var valueTag cbasn1.Tag
+			var valueTag cryptobyte_asn1.Tag
 			if !atav.ReadAnyASN1(&rawValue, &valueTag) {
 				return nil, errors.New("x509: invalid RDNSequence: invalid attribute value")
 			}
@@ -149,7 +148,7 @@ func parseAI(der cryptobyte.String) (pkix.AlgorithmIdentifier, error) {
 		return ai, nil
 	}
 	var params cryptobyte.String
-	var tag cbasn1.Tag
+	var tag cryptobyte_asn1.Tag
 	if !der.ReadAnyASN1Element(¶ms, &tag) {
 		return ai, errors.New("x509: malformed parameters")
 	}
@@ -162,11 +161,11 @@ func parseValidity(der cryptobyte.String) (time.Time, time.Time, error) {
 	extract := func() (time.Time, error) {
 		var t time.Time
 		switch {
-		case der.PeekASN1Tag(cbasn1.UTCTime):
+		case der.PeekASN1Tag(cryptobyte_asn1.UTCTime):
 			// TODO(rolandshoemaker): once #45411 is fixed, the following code
 			// should be replaced with a call to der.ReadASN1UTCTime.
 			var utc cryptobyte.String
-			if !der.ReadASN1(&utc, cbasn1.UTCTime) {
+			if !der.ReadASN1(&utc, cryptobyte_asn1.UTCTime) {
 				return t, errors.New("x509: malformed UTCTime")
 			}
 			s := string(utc)
@@ -190,7 +189,7 @@ func parseValidity(der cryptobyte.String) (time.Time, time.Time, error) {
 				// UTCTime only encodes times prior to 2050. See https://tools.ietf.org/html/rfc5280#section-4.1.2.5.1
 				t = t.AddDate(-100, 0, 0)
 			}
-		case der.PeekASN1Tag(cbasn1.GeneralizedTime):
+		case der.PeekASN1Tag(cryptobyte_asn1.GeneralizedTime):
 			if !der.ReadASN1GeneralizedTime(&t) {
 				return t, errors.New("x509: malformed GeneralizedTime")
 			}
@@ -217,13 +216,13 @@ func parseExtension(der cryptobyte.String) (pkix.Extension, error) {
 	if !der.ReadASN1ObjectIdentifier(&ext.Id) {
 		return ext, errors.New("x509: malformed extention OID field")
 	}
-	if der.PeekASN1Tag(cbasn1.BOOLEAN) {
+	if der.PeekASN1Tag(cryptobyte_asn1.BOOLEAN) {
 		if !der.ReadASN1Boolean(&ext.Critical) {
 			return ext, errors.New("x509: malformed extention critical field")
 		}
 	}
 	var val cryptobyte.String
-	if !der.ReadASN1(&val, cbasn1.OCTET_STRING) {
+	if !der.ReadASN1(&val, cryptobyte_asn1.OCTET_STRING) {
 		return ext, errors.New("x509: malformed extention value field")
 	}
 	ext.Value = val
@@ -241,7 +240,7 @@ func parsePublicKey(algo PublicKeyAlgorithm, keyData *publicKeyInfo) (interface{
 		}
 
 		p := &pkcs1PublicKey{N: new(big.Int)}
-		if !der.ReadASN1(&der, cbasn1.SEQUENCE) {
+		if !der.ReadASN1(&der, cryptobyte_asn1.SEQUENCE) {
 			return nil, errors.New("x509: invalid RSA public key")
 		}
 		if !der.ReadASN1Integer(p.N) {
@@ -307,7 +306,7 @@ func parsePublicKey(algo PublicKeyAlgorithm, keyData *publicKeyInfo) (interface{
 			},
 		}
 		paramsDer := cryptobyte.String(keyData.Algorithm.Parameters.FullBytes)
-		if !paramsDer.ReadASN1(¶msDer, cbasn1.SEQUENCE) ||
+		if !paramsDer.ReadASN1(¶msDer, cryptobyte_asn1.SEQUENCE) ||
 			!paramsDer.ReadASN1Integer(pub.Parameters.P) ||
 			!paramsDer.ReadASN1Integer(pub.Parameters.Q) ||
 			!paramsDer.ReadASN1Integer(pub.Parameters.G) {
@@ -340,16 +339,16 @@ func parseKeyUsageExtension(der cryptobyte.String) (KeyUsage, error) {
 
 func parseBasicConstraintsExtension(der cryptobyte.String) (bool, int, error) {
 	var isCA bool
-	if !der.ReadASN1(&der, cbasn1.SEQUENCE) {
+	if !der.ReadASN1(&der, cryptobyte_asn1.SEQUENCE) {
 		return false, 0, errors.New("x509: invalid basic constraints a")
 	}
-	if der.PeekASN1Tag(cbasn1.BOOLEAN) {
+	if der.PeekASN1Tag(cryptobyte_asn1.BOOLEAN) {
 		if !der.ReadASN1Boolean(&isCA) {
 			return false, 0, errors.New("x509: invalid basic constraints b")
 		}
 	}
 	maxPathLen := -1
-	if !der.Empty() && der.PeekASN1Tag(cbasn1.INTEGER) {
+	if !der.Empty() && der.PeekASN1Tag(cryptobyte_asn1.INTEGER) {
 		if !der.ReadASN1Integer(&maxPathLen) {
 			return false, 0, errors.New("x509: invalid basic constraints c")
 		}
@@ -360,12 +359,12 @@ func parseBasicConstraintsExtension(der cryptobyte.String) (bool, int, error) {
 }
 
 func forEachSAN(der cryptobyte.String, callback func(tag int, data []byte) error) error {
-	if !der.ReadASN1(&der, cbasn1.SEQUENCE) {
+	if !der.ReadASN1(&der, cryptobyte_asn1.SEQUENCE) {
 		return errors.New("x509: invalid subject alternative names")
 	}
 	for !der.Empty() {
 		var san cryptobyte.String
-		var tag cbasn1.Tag
+		var tag cryptobyte_asn1.Tag
 		if !der.ReadAnyASN1(&san, &tag) {
 			return errors.New("x509: invalid subject alternative name")
 		}
@@ -425,7 +424,7 @@ func parseSANExtension(der cryptobyte.String) (dnsNames, emailAddresses []string
 func parseExtKeyUsageExtension(der cryptobyte.String) ([]ExtKeyUsage, []asn1.ObjectIdentifier, error) {
 	var extKeyUsages []ExtKeyUsage
 	var unknownUsages []asn1.ObjectIdentifier
-	if !der.ReadASN1(&der, cbasn1.SEQUENCE) {
+	if !der.ReadASN1(&der, cryptobyte_asn1.SEQUENCE) {
 		return nil, nil, errors.New("x509: invalid extended key usages")
 	}
 	for !der.Empty() {
@@ -444,12 +443,12 @@ func parseExtKeyUsageExtension(der cryptobyte.String) ([]ExtKeyUsage, []asn1.Obj
 
 func parseCertificatePoliciesExtension(der cryptobyte.String) ([]asn1.ObjectIdentifier, error) {
 	var oids []asn1.ObjectIdentifier
-	if !der.ReadASN1(&der, cbasn1.SEQUENCE) {
+	if !der.ReadASN1(&der, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: invalid certificate policies")
 	}
 	for !der.Empty() {
 		var cp cryptobyte.String
-		if !der.ReadASN1(&cp, cbasn1.SEQUENCE) {
+		if !der.ReadASN1(&cp, cryptobyte_asn1.SEQUENCE) {
 			return nil, errors.New("x509: invalid certificate policies")
 		}
 		var oid asn1.ObjectIdentifier
@@ -697,31 +696,31 @@ func processExtensions(out *Certificate) error {
 				//     fullName                [0]     GeneralNames,
 				//     nameRelativeToCRLIssuer [1]     RelativeDistinguishedName }
 				val := cryptobyte.String(e.Value)
-				if !val.ReadASN1(&val, cbasn1.SEQUENCE) {
+				if !val.ReadASN1(&val, cryptobyte_asn1.SEQUENCE) {
 					return errors.New("x509: invalid CRL distribution points")
 				}
 				for !val.Empty() {
 					var dpDER cryptobyte.String
-					if !val.ReadASN1(&dpDER, cbasn1.SEQUENCE) {
+					if !val.ReadASN1(&dpDER, cryptobyte_asn1.SEQUENCE) {
 						return errors.New("x509: invalid CRL distribution point")
 					}
 					var dpNameDER cryptobyte.String
 					var dpNamePresent bool
-					if !dpDER.ReadOptionalASN1(&dpNameDER, &dpNamePresent, cbasn1.Tag(0).Constructed().ContextSpecific()) {
+					if !dpDER.ReadOptionalASN1(&dpNameDER, &dpNamePresent, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific()) {
 						return errors.New("x509: invalid CRL distribution point")
 					}
 					if !dpNamePresent {
 						continue
 					}
-					if !dpNameDER.ReadASN1(&dpNameDER, cbasn1.Tag(0).Constructed().ContextSpecific()) {
+					if !dpNameDER.ReadASN1(&dpNameDER, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific()) {
 						return errors.New("x509: invalid CRL distribution point")
 					}
 					for !dpNameDER.Empty() {
-						if !dpNameDER.PeekASN1Tag(cbasn1.Tag(6).ContextSpecific()) {
+						if !dpNameDER.PeekASN1Tag(cryptobyte_asn1.Tag(6).ContextSpecific()) {
 							break
 						}
 						var uri cryptobyte.String
-						if !dpNameDER.ReadASN1(&uri, cbasn1.Tag(6).ContextSpecific()) {
+						if !dpNameDER.ReadASN1(&uri, cryptobyte_asn1.Tag(6).ContextSpecific()) {
 							return errors.New("x509: invalid CRL distribution point")
 						}
 						out.CRLDistributionPoints = append(out.CRLDistributionPoints, string(uri))
@@ -732,13 +731,15 @@ func processExtensions(out *Certificate) error {
 				// RFC 5280, 4.2.1.1
 				val := cryptobyte.String(e.Value)
 				var akid cryptobyte.String
-				if !val.ReadASN1(&akid, cbasn1.SEQUENCE) {
+				if !val.ReadASN1(&akid, cryptobyte_asn1.SEQUENCE) {
 					return errors.New("x509: invalid authority key identifier")
 				}
-				if !akid.ReadASN1(&akid, cbasn1.Tag(0).ContextSpecific()) {
-					return errors.New("x509: invalid authority key identifier")
+				if akid.PeekASN1Tag(cryptobyte_asn1.Tag(0).ContextSpecific()) {
+					if !akid.ReadASN1(&akid, cryptobyte_asn1.Tag(0).ContextSpecific()) {
+						return errors.New("x509: invalid authority key identifier")
+					}
+					out.AuthorityKeyId = akid
 				}
-				out.AuthorityKeyId = akid
 			case 37:
 				out.ExtKeyUsage, out.UnknownExtKeyUsage, err = parseExtKeyUsageExtension(e.Value)
 				if err != nil {
@@ -748,7 +749,7 @@ func processExtensions(out *Certificate) error {
 				// RFC 5280, 4.2.1.2
 				val := cryptobyte.String(e.Value)
 				var skid cryptobyte.String
-				if !val.ReadASN1(&skid, cbasn1.OCTET_STRING) {
+				if !val.ReadASN1(&skid, cryptobyte_asn1.OCTET_STRING) {
 					return errors.New("x509: invalid subject key identifier")
 				}
 				out.SubjectKeyId = skid
@@ -764,22 +765,22 @@ func processExtensions(out *Certificate) error {
 		} else if e.Id.Equal(oidExtensionAuthorityInfoAccess) {
 			// RFC 5280 4.2.2.1: Authority Information Access
 			val := cryptobyte.String(e.Value)
-			if !val.ReadASN1(&val, cbasn1.SEQUENCE) {
+			if !val.ReadASN1(&val, cryptobyte_asn1.SEQUENCE) {
 				return errors.New("x509: invalid authority info access")
 			}
 			for !val.Empty() {
 				var aiaDER cryptobyte.String
-				if !val.ReadASN1(&aiaDER, cbasn1.SEQUENCE) {
+				if !val.ReadASN1(&aiaDER, cryptobyte_asn1.SEQUENCE) {
 					return errors.New("x509: invalid authority info access")
 				}
 				var method asn1.ObjectIdentifier
 				if !aiaDER.ReadASN1ObjectIdentifier(&method) {
 					return errors.New("x509: invalid authority info access")
 				}
-				if !aiaDER.PeekASN1Tag(cbasn1.Tag(6).ContextSpecific()) {
+				if !aiaDER.PeekASN1Tag(cryptobyte_asn1.Tag(6).ContextSpecific()) {
 					continue
 				}
-				if !aiaDER.ReadASN1(&aiaDER, cbasn1.Tag(6).ContextSpecific()) {
+				if !aiaDER.ReadASN1(&aiaDER, cryptobyte_asn1.Tag(6).ContextSpecific()) {
 					return errors.New("x509: invalid authority info access")
 				}
 				switch {
@@ -809,26 +810,26 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	// we read the SEQUENCE including length and tag bytes so that
 	// we can populate Certificate.Raw, before unwrapping the
 	// SEQUENCE so it can be operated on
-	if !input.ReadASN1Element(&input, cbasn1.SEQUENCE) {
+	if !input.ReadASN1Element(&input, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed certificate")
 	}
 	cert.Raw = input
-	if !input.ReadASN1(&input, cbasn1.SEQUENCE) {
+	if !input.ReadASN1(&input, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed certificate")
 	}
 
 	var tbs cryptobyte.String
 	// do the same trick again as above to extract the raw
 	// bytes for Certificate.RawTBSCertificate
-	if !input.ReadASN1Element(&tbs, cbasn1.SEQUENCE) {
+	if !input.ReadASN1Element(&tbs, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed tbs certificate")
 	}
 	cert.RawTBSCertificate = tbs
-	if !tbs.ReadASN1(&tbs, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1(&tbs, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed tbs certificate")
 	}
 
-	if !tbs.ReadOptionalASN1Integer(&cert.Version, cbasn1.Tag(0).Constructed().ContextSpecific(), 0) {
+	if !tbs.ReadOptionalASN1Integer(&cert.Version, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific(), 0) {
 		return nil, errors.New("x509: malformed version")
 	}
 	if cert.Version < 0 {
@@ -853,14 +854,14 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	cert.SerialNumber = serial
 
 	var sigAISeq cryptobyte.String
-	if !tbs.ReadASN1(&sigAISeq, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1(&sigAISeq, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed signature algorithm identifier")
 	}
 	// Before parsing the inner algorithm identifier, extract
 	// the outer algorithm identifier and make sure that they
 	// match.
 	var outerSigAISeq cryptobyte.String
-	if !input.ReadASN1(&outerSigAISeq, cbasn1.SEQUENCE) {
+	if !input.ReadASN1(&outerSigAISeq, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed algorithm identifier")
 	}
 	if !bytes.Equal(outerSigAISeq, sigAISeq) {
@@ -873,7 +874,7 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	cert.SignatureAlgorithm = getSignatureAlgorithmFromAI(sigAI)
 
 	var issuerSeq cryptobyte.String
-	if !tbs.ReadASN1Element(&issuerSeq, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1Element(&issuerSeq, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed issuer")
 	}
 	cert.RawIssuer = issuerSeq
@@ -884,7 +885,7 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	cert.Issuer.FillFromRDNSequence(issuerRDNs)
 
 	var validity cryptobyte.String
-	if !tbs.ReadASN1(&validity, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1(&validity, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed validity")
 	}
 	cert.NotBefore, cert.NotAfter, err = parseValidity(validity)
@@ -893,7 +894,7 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	}
 
 	var subjectSeq cryptobyte.String
-	if !tbs.ReadASN1Element(&subjectSeq, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1Element(&subjectSeq, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed issuer")
 	}
 	cert.RawSubject = subjectSeq
@@ -904,15 +905,15 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	cert.Subject.FillFromRDNSequence(subjectRDNs)
 
 	var spki cryptobyte.String
-	if !tbs.ReadASN1Element(&spki, cbasn1.SEQUENCE) {
+	if !tbs.ReadASN1Element(&spki, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed spki")
 	}
 	cert.RawSubjectPublicKeyInfo = spki
-	if !spki.ReadASN1(&spki, cbasn1.SEQUENCE) {
+	if !spki.ReadASN1(&spki, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed spki")
 	}
 	var pkAISeq cryptobyte.String
-	if !spki.ReadASN1(&pkAISeq, cbasn1.SEQUENCE) {
+	if !spki.ReadASN1(&pkAISeq, cryptobyte_asn1.SEQUENCE) {
 		return nil, errors.New("x509: malformed public key algorithm identifier")
 	}
 	pkAI, err := parseAI(pkAISeq)
@@ -933,25 +934,25 @@ func parseCertificate(der []byte) (*Certificate, error) {
 	}
 
 	if cert.Version > 1 {
-		if !tbs.SkipOptionalASN1(cbasn1.Tag(1).Constructed().ContextSpecific()) {
+		if !tbs.SkipOptionalASN1(cryptobyte_asn1.Tag(1).Constructed().ContextSpecific()) {
 			return nil, errors.New("x509: malformed issuerUniqueID")
 		}
-		if !tbs.SkipOptionalASN1(cbasn1.Tag(2).Constructed().ContextSpecific()) {
+		if !tbs.SkipOptionalASN1(cryptobyte_asn1.Tag(2).Constructed().ContextSpecific()) {
 			return nil, errors.New("x509: malformed subjectUniqueID")
 		}
 		if cert.Version == 3 {
 			var extensions cryptobyte.String
 			var present bool
-			if !tbs.ReadOptionalASN1(&extensions, &present, cbasn1.Tag(3).Constructed().ContextSpecific()) {
+			if !tbs.ReadOptionalASN1(&extensions, &present, cryptobyte_asn1.Tag(3).Constructed().ContextSpecific()) {
 				return nil, errors.New("x509: malformed extensions")
 			}
 			if present {
-				if !extensions.ReadASN1(&extensions, cbasn1.SEQUENCE) {
+				if !extensions.ReadASN1(&extensions, cryptobyte_asn1.SEQUENCE) {
 					return nil, errors.New("x509: malformed extensions")
 				}
 				for !extensions.Empty() {
 					var extension cryptobyte.String
-					if !extensions.ReadASN1(&extension, cbasn1.SEQUENCE) {
+					if !extensions.ReadASN1(&extension, cryptobyte_asn1.SEQUENCE) {
 						return nil, errors.New("x509: malformed extension")
 					}
 					ext, err := parseExtension(extension)
diff --git a/src/crypto/x509/root.go b/src/crypto/x509/root.go
index cc53f7aefca..eef9c047b2e 100644
--- a/src/crypto/x509/root.go
+++ b/src/crypto/x509/root.go
@@ -8,7 +8,7 @@ package x509
 // argument to the latest security_certificates version from
 // https://opensource.apple.com/source/security_certificates/
 // and run "go generate". See https://golang.org/issue/38843.
-//go:generate go run root_ios_gen.go -version 55188.40.9
+//go:generate go run root_ios_gen.go -version 55188.120.1.0.1
 
 import "sync"
 
diff --git a/src/crypto/x509/root_bsd.go b/src/crypto/x509/root_bsd.go
index 822e8573ff1..6712ea32a68 100644
--- a/src/crypto/x509/root_bsd.go
+++ b/src/crypto/x509/root_bsd.go
@@ -18,6 +18,7 @@ var certFiles = []string{
 // Possible directories with certificate files; stop after successfully
 // reading at least one file from a directory.
 var certDirectories = []string{
+	"/etc/ssl/certs",         // FreeBSD 12.2+
 	"/usr/local/share/certs", // FreeBSD
 	"/etc/openssl/certs",     // NetBSD
 }
diff --git a/src/crypto/x509/root_ios.go b/src/crypto/x509/root_ios.go
index 50432f3d2c5..9bc62f8abb6 100644
--- a/src/crypto/x509/root_ios.go
+++ b/src/crypto/x509/root_ios.go
@@ -1,4 +1,4 @@
-// Code generated by root_ios_gen.go -version 55188.40.9; DO NOT EDIT.
+// Code generated by root_ios_gen.go -version 55188.120.1.0.1; DO NOT EDIT.
 // Update the version in root.go and regenerate with "go generate".
 
 //go:build ios && !x509omitbundledroots
@@ -2223,6 +2223,41 @@ uOJAf/sKbvu+M8k8o4TVMAoGCCqGSM49BAMCA0gAMEUCIQDckqGgE6bPA7DmxCGX
 kPoUVy0D7O48027KqGx2vKLeuwIgJ6iFJzWbVsaj8kfSt24bAgAXqmemFZHe+pTs
 ewv4n4Q=
 -----END CERTIFICATE-----
+# "GlobalSign"
+# 2C AB EA FE 37 D0 6C A2 2A BA 73 91 C0 03 3D 25
+# 98 29 52 C4 53 64 73 49 76 3A 3A B5 AD 6C CF 69
+-----BEGIN CERTIFICATE-----
+MIIFgzCCA2ugAwIBAgIORea7A4Mzw4VlSOb/RVEwDQYJKoZIhvcNAQEMBQAwTDEg
+MB4GA1UECxMXR2xvYmFsU2lnbiBSb290IENBIC0gUjYxEzARBgNVBAoTCkdsb2Jh
+bFNpZ24xEzARBgNVBAMTCkdsb2JhbFNpZ24wHhcNMTQxMjEwMDAwMDAwWhcNMzQx
+MjEwMDAwMDAwWjBMMSAwHgYDVQQLExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSNjET
+MBEGA1UEChMKR2xvYmFsU2lnbjETMBEGA1UEAxMKR2xvYmFsU2lnbjCCAiIwDQYJ
+KoZIhvcNAQEBBQADggIPADCCAgoCggIBAJUH6HPKZvnsFMp7PPcNCPG0RQssgrRI
+xutbPK6DuEGSMxSkb3/pKszGsIhrxbaJ0cay/xTOURQh7ErdG1rG1ofuTToVBu1k
+ZguSgMpE3nOUTvOniX9PeGMIyBJQbUJmL025eShNUhqKGoC3GYEOfsSKvGRMIRxD
+aNc9PIrFsmbVkJq3MQbFvuJtMgamHvm566qjuL++gmNQ0PAYid/kD3n16qIfKtJw
+LnvnvJO7bVPiSHyMEAc4/2ayd2F+4OqMPKq0pPbzlUoSB239jLKJz9CgYXfIWHSw
+1CM69106yqLbnQneXUQtkPGBzVeS+n68UARjNN9rkxi+azayOeSsJDa38O+2HBNX
+k7besvjihbdzorg1qkXy4J02oW9UivFyVm4uiMVRQkQVlO6jxTiWm05OWgtH8wY2
+SXcwvHE35absIQh1/OZhFj931dmRl4QKbNQCTXTAFO39OfuD8l4UoQSwC+n+7o/h
+bguyCLNhZglqsQY6ZZZZwPA1/cnaKI0aEYdwgQqomnUdnjqGBQCe24DWJfncBZ4n
+WUx2OVvq+aWh2IMP0f/fMBH5hc8zSPXKbWQULHpYT9NLCEnFlWQaYw55PfWzjMpY
+rZxCRXluDocZXFSxZba/jJvcE+kNb7gu3GduyYsRtYQUigAZcIN5kZeR1Bonvzce
+MgfYFGM8KEyvAgMBAAGjYzBhMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMBAf8EBTAD
+AQH/MB0GA1UdDgQWBBSubAWjkxPioufi1xzWx/B/yGdToDAfBgNVHSMEGDAWgBSu
+bAWjkxPioufi1xzWx/B/yGdToDANBgkqhkiG9w0BAQwFAAOCAgEAgyXt6NH9lVLN
+nsAEoJFp5lzQhN7craJP6Ed41mWYqVuoPId8AorRbrcWc+ZfwFSY1XS+wc3iEZGt
+Ixg93eFyRJa0lV7Ae46ZeBZDE1ZXs6KzO7V33EByrKPrmzU+sQghoefEQzd5Mr61
+55wsTLxDKZmOMNOsIeDjHfrYBzN2VAAiKrlNIC5waNrlU/yDXNOd8v9EDERm8tLj
+vUYAGm0CuiVdjaExUd1URhxN25mW7xocBFymFe944Hn+Xds+qkxV/ZoVqW/hpvvf
+cDDpw+5CRu3CkwWJ+n1jez/QcYF8AOiYrg54NMMl+68KnyBr3TsTjxKM4kEaSHpz
+oHdpx7Zcf4LIHv5YGygrqGytXm3ABdJ7t+uA/iU3/gKbaKxCXcPu9czc8FB10jZp
+nOZ7BN9uBmm23goJSFmH63sUYHpkqmlD75HHTOwY3WzvUy2MmeFe8nI+z1TIvWfs
+pA9MRf/TuTAjB0yPEL+GltmZWrSZVxykzLsViVO6LAUP5MSeGbEYNNVMnbrt9x+v
+JJUEeKgDu+6B5dpffItKoZB0JaezPkvILFa9x8jvOOJckvB595yEunQtYQEgfn7R
+8k8HWV+LLUNS60YMlOH1Zkd5d9VUWx+tJDfLRVpOoERIyNiwmcUVhAn21klJwGW4
+5hpxbqCo8YLoRT5s1gLXCmeDBVrJpBA=
+-----END CERTIFICATE-----
 # "GlobalSign Root CA"
 # EB D4 10 40 E4 BB 3E C7 42 C9 E3 81 D3 1E F2 A4
 # 1A 48 B6 68 5C 96 E7 CE F3 C1 DF 6C D4 33 1C 99
diff --git a/src/crypto/x509/x509.go b/src/crypto/x509/x509.go
index ff37b361d75..4304ab54e1a 100644
--- a/src/crypto/x509/x509.go
+++ b/src/crypto/x509/x509.go
@@ -1413,8 +1413,8 @@ func signingParamsForPublicKey(pub interface{}, requestedSigAlgo SignatureAlgori
 // just an empty SEQUENCE.
 var emptyASN1Subject = []byte{0x30, 0}
 
-// CreateCertificate creates a new X.509v3 certificate based on a template.
-// The following members of template are used:
+// CreateCertificate creates a new X.509 v3 certificate based on a template.
+// The following members of template are currently used:
 //
 //  - AuthorityKeyId
 //  - BasicConstraintsValid
@@ -1451,7 +1451,7 @@ var emptyASN1Subject = []byte{0x30, 0}
 //
 // The certificate is signed by parent. If parent is equal to template then the
 // certificate is self-signed. The parameter pub is the public key of the
-// signee and priv is the private key of the signer.
+// certificate to be generated and priv is the private key of the signer.
 //
 // The returned slice is the certificate in DER encoding.
 //
@@ -1465,7 +1465,7 @@ var emptyASN1Subject = []byte{0x30, 0}
 //
 // If SubjectKeyId from template is empty and the template is a CA, SubjectKeyId
 // will be generated from the hash of the public key.
-func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv interface{}) (cert []byte, err error) {
+func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv interface{}) ([]byte, error) {
 	key, ok := priv.(crypto.Signer)
 	if !ok {
 		return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
@@ -1491,12 +1491,12 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv
 
 	asn1Issuer, err := subjectBytes(parent)
 	if err != nil {
-		return
+		return nil, err
 	}
 
 	asn1Subject, err := subjectBytes(template)
 	if err != nil {
-		return
+		return nil, err
 	}
 
 	authorityKeyId := template.AuthorityKeyId
@@ -1514,9 +1514,19 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv
 		subjectKeyId = h[:]
 	}
 
+	// Check that the signer's public key matches the private key, if available.
+	type privateKey interface {
+		Equal(crypto.PublicKey) bool
+	}
+	if privPub, ok := key.Public().(privateKey); !ok {
+		return nil, errors.New("x509: internal error: supported public key does not implement Equal")
+	} else if parent.PublicKey != nil && !privPub.Equal(parent.PublicKey) {
+		return nil, errors.New("x509: provided PrivateKey doesn't match parent's PublicKey")
+	}
+
 	extensions, err := buildCertExtensions(template, bytes.Equal(asn1Subject, emptyASN1Subject), authorityKeyId, subjectKeyId)
 	if err != nil {
-		return
+		return nil, err
 	}
 
 	encodedPublicKey := asn1.BitString{BitLength: len(publicKeyBytes) * 8, Bytes: publicKeyBytes}
@@ -1533,7 +1543,7 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv
 
 	tbsCertContents, err := asn1.Marshal(c)
 	if err != nil {
-		return
+		return nil, err
 	}
 	c.Raw = tbsCertContents
 
@@ -1555,7 +1565,7 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv
 	var signature []byte
 	signature, err = key.Sign(rand, signed, signerOpts)
 	if err != nil {
-		return
+		return nil, err
 	}
 
 	signedCert, err := asn1.Marshal(certificate{
diff --git a/src/crypto/x509/x509_test.go b/src/crypto/x509/x509_test.go
index 802bce0f9af..a4053abf41d 100644
--- a/src/crypto/x509/x509_test.go
+++ b/src/crypto/x509/x509_test.go
@@ -3174,3 +3174,45 @@ func TestSigAlgMismatch(t *testing.T) {
 		}
 	}
 }
+
+const optionalAuthKeyIDPEM = `-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`
+
+func TestAuthKeyIdOptional(t *testing.T) {
+	b, _ := pem.Decode([]byte(optionalAuthKeyIDPEM))
+	if b == nil {
+		t.Fatalf("couldn't decode test certificate")
+	}
+	_, err := ParseCertificate(b.Bytes)
+	if err != nil {
+		t.Fatalf("ParseCertificate to failed to parse certificate with optional authority key identifier fields: %s", err)
+	}
+}
diff --git a/src/database/sql/sql_test.go b/src/database/sql/sql_test.go
index 80f63e877d0..f771dee4a97 100644
--- a/src/database/sql/sql_test.go
+++ b/src/database/sql/sql_test.go
@@ -2838,7 +2838,7 @@ func TestTxStmtDeadlock(t *testing.T) {
 	db := newTestDB(t, "people")
 	defer closeDB(t, db)
 
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Millisecond)
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	tx, err := db.BeginTx(ctx, nil)
 	if err != nil {
@@ -2849,6 +2849,7 @@ func TestTxStmtDeadlock(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	cancel()
 	// Run number of stmt queries to reproduce deadlock from context cancel
 	for i := 0; i < 1e3; i++ {
 		// Encounter any close related errors (e.g. ErrTxDone, stmt is closed)
diff --git a/src/debug/dwarf/type.go b/src/debug/dwarf/type.go
index 316db258f65..eb5a666ed38 100644
--- a/src/debug/dwarf/type.go
+++ b/src/debug/dwarf/type.go
@@ -292,11 +292,35 @@ func (d *Data) Type(off Offset) (Type, error) {
 	return d.readType("info", d.Reader(), off, d.typeCache, nil)
 }
 
+type typeFixer struct {
+	typedefs   []*TypedefType
+	arraytypes []*Type
+}
+
+func (tf *typeFixer) recordArrayType(t *Type) {
+	if t == nil {
+		return
+	}
+	_, ok := (*t).(*ArrayType)
+	if ok {
+		tf.arraytypes = append(tf.arraytypes, t)
+	}
+}
+
+func (tf *typeFixer) apply() {
+	for _, t := range tf.typedefs {
+		t.Common().ByteSize = t.Type.Size()
+	}
+	for _, t := range tf.arraytypes {
+		zeroArray(t)
+	}
+}
+
 // readType reads a type from r at off of name. It adds types to the
 // type cache, appends new typedef types to typedefs, and computes the
 // sizes of types. Callers should pass nil for typedefs; this is used
 // for internal recursion.
-func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Offset]Type, typedefs *[]*TypedefType) (Type, error) {
+func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Offset]Type, fixups *typeFixer) (Type, error) {
 	if t, ok := typeCache[off]; ok {
 		return t, nil
 	}
@@ -311,18 +335,16 @@ func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Off
 	}
 
 	// If this is the root of the recursion, prepare to resolve
-	// typedef sizes once the recursion is done. This must be done
-	// after the type graph is constructed because it may need to
-	// resolve cycles in a different order than readType
-	// encounters them.
-	if typedefs == nil {
-		var typedefList []*TypedefType
+	// typedef sizes and perform other fixups once the recursion is
+	// done. This must be done after the type graph is constructed
+	// because it may need to resolve cycles in a different order than
+	// readType encounters them.
+	if fixups == nil {
+		var fixer typeFixer
 		defer func() {
-			for _, t := range typedefList {
-				t.Common().ByteSize = t.Type.Size()
-			}
+			fixer.apply()
 		}()
-		typedefs = &typedefList
+		fixups = &fixer
 	}
 
 	// Parse type from Entry.
@@ -376,7 +398,7 @@ func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Off
 		var t Type
 		switch toff := tval.(type) {
 		case Offset:
-			if t, err = d.readType(name, r.clone(), toff, typeCache, typedefs); err != nil {
+			if t, err = d.readType(name, r.clone(), toff, typeCache, fixups); err != nil {
 				return nil
 			}
 		case uint64:
@@ -567,7 +589,7 @@ func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Off
 			if bito == lastFieldBitOffset && t.Kind != "union" {
 				// Last field was zero width. Fix array length.
 				// (DWARF writes out 0-length arrays as if they were 1-length arrays.)
-				zeroArray(lastFieldType)
+				fixups.recordArrayType(lastFieldType)
 			}
 			lastFieldType = &f.Type
 			lastFieldBitOffset = bito
@@ -576,7 +598,7 @@ func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Off
 			b, ok := e.Val(AttrByteSize).(int64)
 			if ok && b*8 == lastFieldBitOffset {
 				// Final field must be zero width. Fix array length.
-				zeroArray(lastFieldType)
+				fixups.recordArrayType(lastFieldType)
 			}
 		}
 
@@ -719,7 +741,7 @@ func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Off
 				// Record that we need to resolve this
 				// type's size once the type graph is
 				// constructed.
-				*typedefs = append(*typedefs, t)
+				fixups.typedefs = append(fixups.typedefs, t)
 			case *PtrType:
 				b = int64(addressSize)
 			}
@@ -737,11 +759,8 @@ Error:
 }
 
 func zeroArray(t *Type) {
-	if t == nil {
-		return
-	}
-	at, ok := (*t).(*ArrayType)
-	if !ok || at.Type.Size() == 0 {
+	at := (*t).(*ArrayType)
+	if at.Type.Size() == 0 {
 		return
 	}
 	// Make a copy to avoid invalidating typeCache.
diff --git a/src/debug/elf/file.go b/src/debug/elf/file.go
index cd5bf8fab00..b25d8209e36 100644
--- a/src/debug/elf/file.go
+++ b/src/debug/elf/file.go
@@ -1164,6 +1164,13 @@ func (f *File) DWARF() (*dwarf.Data, error) {
 			b = dbuf
 		}
 
+		if f.Type == ET_EXEC {
+			// Do not apply relocations to DWARF sections for ET_EXEC binaries.
+			// Relocations should already be applied, and .rela sections may
+			// contain incorrect data.
+			return b, nil
+		}
+
 		for _, r := range f.Sections {
 			if r.Type != SHT_RELA && r.Type != SHT_REL {
 				continue
diff --git a/src/debug/macho/macho.go b/src/debug/macho/macho.go
index 49e107eed3d..9fa9f957529 100644
--- a/src/debug/macho/macho.go
+++ b/src/debug/macho/macho.go
@@ -4,7 +4,7 @@
 
 // Mach-O header data structures
 // Originally at:
-// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html (since deleted by Apply)
+// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html (since deleted by Apple)
 // Archived copy at:
 // https://web.archive.org/web/20090819232456/http://developer.apple.com/documentation/DeveloperTools/Conceptual/MachORuntime/index.html
 // For cloned PDF see:
diff --git a/src/fmt/doc.go b/src/fmt/doc.go
index d05ee519c3d..c584cc9465e 100644
--- a/src/fmt/doc.go
+++ b/src/fmt/doc.go
@@ -189,7 +189,7 @@
 	When printing a struct, fmt cannot and therefore does not invoke
 	formatting methods such as Error or String on unexported fields.
 
-	Explicit argument indexes:
+	Explicit argument indexes
 
 	In Printf, Sprintf, and Fprintf, the default behavior is for each
 	formatting verb to format successive arguments passed in the call.
@@ -211,7 +211,7 @@
 		fmt.Sprintf("%d %d %#[1]x %#x", 16, 17)
 	will yield "16 17 0x10 0x11".
 
-	Format errors:
+	Format errors
 
 	If an invalid argument is given for a verb, such as providing
 	a string to %d, the generated string will contain a
diff --git a/src/go.mod b/src/go.mod
index a3ceb05890e..1fb8cbfcbe0 100644
--- a/src/go.mod
+++ b/src/go.mod
@@ -1,10 +1,10 @@
 module std
 
-go 1.17
+go 1.18
 
 require (
 	golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e
-	golang.org/x/net v0.0.0-20210505024714-0287a6fb4125
-	golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6 // indirect
+	golang.org/x/net v0.0.0-20210510120150-4163338589ed
+	golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744 // indirect
 	golang.org/x/text v0.3.7-0.20210503195748-5c7c50ebbd4f // indirect
 )
diff --git a/src/go.sum b/src/go.sum
index 27513a350dd..b3de6c526c9 100644
--- a/src/go.sum
+++ b/src/go.sum
@@ -1,8 +1,8 @@
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e h1:8foAy0aoO5GkqCvAEJ4VC4P3zksTg4X4aJCDpZzmgQI=
 golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
-golang.org/x/net v0.0.0-20210505024714-0287a6fb4125 h1:Ugb8sMTWuWRC3+sz5WeN/4kejDx9BvIwnPUiJBjJE+8=
-golang.org/x/net v0.0.0-20210505024714-0287a6fb4125/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6 h1:cdsMqa2nXzqlgs183pHxtvoVwU7CyzaCTAUOg94af4c=
-golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/net v0.0.0-20210510120150-4163338589ed h1:p9UgmWI9wKpfYmgaV/IZKGdXc5qEK45tDwwwDyjS26I=
+golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744 h1:yhBbb4IRs2HS9PPlAg6DMC6mUOKexJBNsLf4Z+6En1Q=
+golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.7-0.20210503195748-5c7c50ebbd4f h1:yQJrRE0hDxDFmZLlRaw+3vusO4fwNHgHIjUOMO7bHYI=
 golang.org/x/text v0.3.7-0.20210503195748-5c7c50ebbd4f/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
diff --git a/src/go/ast/ast.go b/src/go/ast/ast.go
index c87529ec77d..b0f13305642 100644
--- a/src/go/ast/ast.go
+++ b/src/go/ast/ast.go
@@ -259,7 +259,7 @@ func (f *FieldList) End() token.Pos {
 	return token.NoPos
 }
 
-// NumFields returns the number of (type) parameters or struct fields represented by a FieldList.
+// NumFields returns the number of parameters or struct fields represented by a FieldList.
 func (f *FieldList) NumFields() int {
 	n := 0
 	if f != nil {
@@ -344,6 +344,15 @@ type (
 		Rbrack token.Pos // position of "]"
 	}
 
+	// A MultiIndexExpr node represents an expression followed by multiple
+	// indices.
+	MultiIndexExpr struct {
+		X       Expr      // expression
+		Lbrack  token.Pos // position of "["
+		Indices []Expr    // index expressions
+		Rbrack  token.Pos // position of "]"
+	}
+
 	// A SliceExpr node represents an expression followed by slice indices.
 	SliceExpr struct {
 		X      Expr      // expression
@@ -440,6 +449,14 @@ type (
 
 	// Pointer types are represented via StarExpr nodes.
 
+	// A FuncType node represents a function type.
+	FuncType struct {
+		Func    token.Pos  // position of "func" keyword (token.NoPos if there is no "func")
+		TParams *FieldList // type parameters; or nil
+		Params  *FieldList // (incoming) parameters; non-nil
+		Results *FieldList // (outgoing) results; or nil
+	}
+
 	// An InterfaceType node represents an interface type.
 	InterfaceType struct {
 		Interface  token.Pos  // position of "interface" keyword
@@ -479,6 +496,7 @@ func (x *CompositeLit) Pos() token.Pos {
 func (x *ParenExpr) Pos() token.Pos      { return x.Lparen }
 func (x *SelectorExpr) Pos() token.Pos   { return x.X.Pos() }
 func (x *IndexExpr) Pos() token.Pos      { return x.X.Pos() }
+func (x *MultiIndexExpr) Pos() token.Pos { return x.X.Pos() }
 func (x *SliceExpr) Pos() token.Pos      { return x.X.Pos() }
 func (x *TypeAssertExpr) Pos() token.Pos { return x.X.Pos() }
 func (x *CallExpr) Pos() token.Pos       { return x.Fun.Pos() }
@@ -512,6 +530,7 @@ func (x *CompositeLit) End() token.Pos   { return x.Rbrace + 1 }
 func (x *ParenExpr) End() token.Pos      { return x.Rparen + 1 }
 func (x *SelectorExpr) End() token.Pos   { return x.Sel.End() }
 func (x *IndexExpr) End() token.Pos      { return x.Rbrack + 1 }
+func (x *MultiIndexExpr) End() token.Pos { return x.Rbrack + 1 }
 func (x *SliceExpr) End() token.Pos      { return x.Rbrack + 1 }
 func (x *TypeAssertExpr) End() token.Pos { return x.Rparen + 1 }
 func (x *CallExpr) End() token.Pos       { return x.Rparen + 1 }
@@ -543,6 +562,7 @@ func (*CompositeLit) exprNode()   {}
 func (*ParenExpr) exprNode()      {}
 func (*SelectorExpr) exprNode()   {}
 func (*IndexExpr) exprNode()      {}
+func (*MultiIndexExpr) exprNode() {}
 func (*SliceExpr) exprNode()      {}
 func (*TypeAssertExpr) exprNode() {}
 func (*CallExpr) exprNode()       {}
@@ -892,6 +912,16 @@ type (
 		Values  []Expr        // initial values; or nil
 		Comment *CommentGroup // line comments; or nil
 	}
+
+	// A TypeSpec node represents a type declaration (TypeSpec production).
+	TypeSpec struct {
+		Doc     *CommentGroup // associated documentation; or nil
+		Name    *Ident        // type name
+		TParams *FieldList    // type parameters; or nil
+		Assign  token.Pos     // position of '=', if any
+		Type    Expr          // *Ident, *ParenExpr, *SelectorExpr, *StarExpr, or any of the *XxxTypes
+		Comment *CommentGroup // line comments; or nil
+	}
 )
 
 // Pos and End implementations for spec nodes.
@@ -973,10 +1003,6 @@ type (
 	}
 )
 
-func (f *FuncDecl) IsMethod() bool {
-	return f.Recv.NumFields() != 0
-}
-
 // Pos and End implementations for declaration nodes.
 
 func (d *BadDecl) Pos() token.Pos  { return d.From }
diff --git a/src/go/ast/ast_notypeparams.go b/src/go/ast/ast_notypeparams.go
deleted file mode 100644
index fa132fba858..00000000000
--- a/src/go/ast/ast_notypeparams.go
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !typeparams
-// +build !typeparams
-
-package ast
-
-import "go/token"
-
-type (
-	// A FuncType node represents a function type.
-	FuncType struct {
-		Func    token.Pos  // position of "func" keyword (token.NoPos if there is no "func")
-		Params  *FieldList // (incoming) parameters; non-nil
-		Results *FieldList // (outgoing) results; or nil
-	}
-
-	// A TypeSpec node represents a type declaration (TypeSpec production).
-	TypeSpec struct {
-		Doc     *CommentGroup // associated documentation; or nil
-		Name    *Ident        // type name
-		Assign  token.Pos     // position of '=', if any
-		Type    Expr          // *Ident, *ParenExpr, *SelectorExpr, *StarExpr, or any of the *XxxTypes
-		Comment *CommentGroup // line comments; or nil
-	}
-)
diff --git a/src/go/ast/ast_typeparams.go b/src/go/ast/ast_typeparams.go
deleted file mode 100644
index 24fdc5f1317..00000000000
--- a/src/go/ast/ast_typeparams.go
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build typeparams
-// +build typeparams
-
-package ast
-
-import "go/token"
-
-type (
-	// A FuncType node represents a function type.
-	FuncType struct {
-		Func    token.Pos  // position of "func" keyword (token.NoPos if there is no "func")
-		TParams *FieldList // type parameters; or nil
-		Params  *FieldList // (incoming) parameters; non-nil
-		Results *FieldList // (outgoing) results; or nil
-	}
-
-	// A TypeSpec node represents a type declaration (TypeSpec production).
-	TypeSpec struct {
-		Doc     *CommentGroup // associated documentation; or nil
-		Name    *Ident        // type name
-		TParams *FieldList    // type parameters; or nil
-		Assign  token.Pos     // position of '=', if any
-		Type    Expr          // *Ident, *ParenExpr, *SelectorExpr, *StarExpr, or any of the *XxxTypes
-		Comment *CommentGroup // line comments; or nil
-	}
-
-	// A ListExpr node represents a list of expressions separated by commas.
-	// ListExpr nodes are used as index in IndexExpr nodes representing type
-	// or function instantiations with more than one type argument.
-	ListExpr struct {
-		ElemList []Expr
-	}
-)
-
-func (*ListExpr) exprNode() {}
-func (x *ListExpr) Pos() token.Pos {
-	if len(x.ElemList) > 0 {
-		return x.ElemList[0].Pos()
-	}
-	return token.NoPos
-}
-func (x *ListExpr) End() token.Pos {
-	if len(x.ElemList) > 0 {
-		return x.ElemList[len(x.ElemList)-1].End()
-	}
-	return token.NoPos
-}
diff --git a/src/go/ast/walk.go b/src/go/ast/walk.go
index 9224264e291..c8abc409728 100644
--- a/src/go/ast/walk.go
+++ b/src/go/ast/walk.go
@@ -4,6 +4,8 @@
 
 package ast
 
+import "fmt"
+
 // A Visitor's Visit method is invoked for each node encountered by Walk.
 // If the result visitor w is not nil, Walk visits each of the children
 // of node with the visitor w, followed by a call of w.Visit(nil).
@@ -114,6 +116,12 @@ func Walk(v Visitor, node Node) {
 		Walk(v, n.X)
 		Walk(v, n.Index)
 
+	case *MultiIndexExpr:
+		Walk(v, n.X)
+		for _, index := range n.Indices {
+			Walk(v, index)
+		}
+
 	case *SliceExpr:
 		Walk(v, n.X)
 		if n.Low != nil {
@@ -161,7 +169,9 @@ func Walk(v Visitor, node Node) {
 		Walk(v, n.Fields)
 
 	case *FuncType:
-		walkFuncTypeParams(v, n)
+		if n.TParams != nil {
+			Walk(v, n.TParams)
+		}
 		if n.Params != nil {
 			Walk(v, n.Params)
 		}
@@ -316,7 +326,9 @@ func Walk(v Visitor, node Node) {
 			Walk(v, n.Doc)
 		}
 		Walk(v, n.Name)
-		walkTypeSpecParams(v, n)
+		if n.TParams != nil {
+			Walk(v, n.TParams)
+		}
 		Walk(v, n.Type)
 		if n.Comment != nil {
 			Walk(v, n.Comment)
@@ -363,7 +375,7 @@ func Walk(v Visitor, node Node) {
 		}
 
 	default:
-		walkOtherNodes(v, n)
+		panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))
 	}
 
 	v.Visit(nil)
diff --git a/src/go/ast/walk_notypeparams.go b/src/go/ast/walk_notypeparams.go
deleted file mode 100644
index d43e13dd11a..00000000000
--- a/src/go/ast/walk_notypeparams.go
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !typeparams
-// +build !typeparams
-
-package ast
-
-import "fmt"
-
-func walkFuncTypeParams(v Visitor, n *FuncType) {}
-func walkTypeSpecParams(v Visitor, n *TypeSpec) {}
-
-func walkOtherNodes(v Visitor, n Node) {
-	panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))
-}
diff --git a/src/go/ast/walk_typeparams.go b/src/go/ast/walk_typeparams.go
deleted file mode 100644
index b6621335b8e..00000000000
--- a/src/go/ast/walk_typeparams.go
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build typeparams
-// +build typeparams
-
-package ast
-
-import (
-	"fmt"
-)
-
-func walkFuncTypeParams(v Visitor, n *FuncType) {
-	if n.TParams != nil {
-		Walk(v, n.TParams)
-	}
-}
-
-func walkTypeSpecParams(v Visitor, n *TypeSpec) {
-	if n.TParams != nil {
-		Walk(v, n.TParams)
-	}
-}
-
-func walkOtherNodes(v Visitor, n Node) {
-	if e, ok := n.(*ListExpr); ok {
-		if e != nil {
-			for _, elem := range e.ElemList {
-				Walk(v, elem)
-			}
-		}
-	} else {
-		panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))
-	}
-}
diff --git a/src/go/build/build.go b/src/go/build/build.go
index c5895290e4c..6e8a89a3927 100644
--- a/src/go/build/build.go
+++ b/src/go/build/build.go
@@ -810,6 +810,17 @@ Found:
 	}
 
 	var badGoError error
+	badFiles := make(map[string]bool)
+	badFile := func(name string, err error) {
+		if badGoError == nil {
+			badGoError = err
+		}
+		if !badFiles[name] {
+			p.InvalidGoFiles = append(p.InvalidGoFiles, name)
+			badFiles[name] = true
+		}
+	}
+
 	var Sfiles []string // files with ".S"(capital S)/.sx(capital s equivalent for case insensitive filesystems)
 	var firstFile, firstCommentFile string
 	embedPos := make(map[string][]token.Position)
@@ -834,16 +845,9 @@ Found:
 		name := d.Name()
 		ext := nameExt(name)
 
-		badFile := func(err error) {
-			if badGoError == nil {
-				badGoError = err
-			}
-			p.InvalidGoFiles = append(p.InvalidGoFiles, name)
-		}
-
 		info, err := ctxt.matchFile(p.Dir, name, allTags, &p.BinaryOnly, fset)
 		if err != nil {
-			badFile(err)
+			badFile(name, err)
 			continue
 		}
 		if info == nil {
@@ -874,15 +878,18 @@ Found:
 		}
 
 		if info.parseErr != nil {
-			badFile(info.parseErr)
-			continue
+			badFile(name, info.parseErr)
+			// Fall through: we might still have a partial AST in info.parsed,
+			// and we want to list files with parse errors anyway.
 		}
-		pf := info.parsed
 
-		pkg := pf.Name.Name
-		if pkg == "documentation" {
-			p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
-			continue
+		var pkg string
+		if info.parsed != nil {
+			pkg = info.parsed.Name.Name
+			if pkg == "documentation" {
+				p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
+				continue
+			}
 		}
 
 		isTest := strings.HasSuffix(name, "_test.go")
@@ -896,16 +903,18 @@ Found:
 			p.Name = pkg
 			firstFile = name
 		} else if pkg != p.Name {
-			badFile(&MultiplePackageError{
+			// TODO(#45999): The choice of p.Name is arbitrary based on file iteration
+			// order. Instead of resolving p.Name arbitrarily, we should clear out the
+			// existing name and mark the existing files as also invalid.
+			badFile(name, &MultiplePackageError{
 				Dir:      p.Dir,
 				Packages: []string{p.Name, pkg},
 				Files:    []string{firstFile, name},
 			})
-			p.InvalidGoFiles = append(p.InvalidGoFiles, name)
 		}
 		// Grab the first package comment as docs, provided it is not from a test file.
-		if pf.Doc != nil && p.Doc == "" && !isTest && !isXTest {
-			p.Doc = doc.Synopsis(pf.Doc.Text())
+		if info.parsed != nil && info.parsed.Doc != nil && p.Doc == "" && !isTest && !isXTest {
+			p.Doc = doc.Synopsis(info.parsed.Doc.Text())
 		}
 
 		if mode&ImportComment != 0 {
@@ -913,12 +922,12 @@ Found:
 			if line != 0 {
 				com, err := strconv.Unquote(qcom)
 				if err != nil {
-					badFile(fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
+					badFile(name, fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
 				} else if p.ImportComment == "" {
 					p.ImportComment = com
 					firstCommentFile = name
 				} else if p.ImportComment != com {
-					badFile(fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
+					badFile(name, fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
 				}
 			}
 		}
@@ -928,13 +937,13 @@ Found:
 		for _, imp := range info.imports {
 			if imp.path == "C" {
 				if isTest {
-					badFile(fmt.Errorf("use of cgo in test %s not supported", filename))
+					badFile(name, fmt.Errorf("use of cgo in test %s not supported", filename))
 					continue
 				}
 				isCgo = true
 				if imp.doc != nil {
 					if err := ctxt.saveCgo(filename, p, imp.doc); err != nil {
-						badFile(err)
+						badFile(name, err)
 					}
 				}
 			}
diff --git a/src/go/build/build_test.go b/src/go/build/build_test.go
index 7e785680831..80f930f3c23 100644
--- a/src/go/build/build_test.go
+++ b/src/go/build/build_test.go
@@ -104,7 +104,8 @@ func TestEmptyFolderImport(t *testing.T) {
 }
 
 func TestMultiplePackageImport(t *testing.T) {
-	_, err := Import(".", "testdata/multi", 0)
+	pkg, err := Import(".", "testdata/multi", 0)
+
 	mpe, ok := err.(*MultiplePackageError)
 	if !ok {
 		t.Fatal(`Import("testdata/multi") did not return MultiplePackageError.`)
@@ -115,7 +116,20 @@ func TestMultiplePackageImport(t *testing.T) {
 		Files:    []string{"file.go", "file_appengine.go"},
 	}
 	if !reflect.DeepEqual(mpe, want) {
-		t.Errorf("got %#v; want %#v", mpe, want)
+		t.Errorf("err = %#v; want %#v", mpe, want)
+	}
+
+	// TODO(#45999): Since the name is ambiguous, pkg.Name should be left empty.
+	if wantName := "main"; pkg.Name != wantName {
+		t.Errorf("pkg.Name = %q; want %q", pkg.Name, wantName)
+	}
+
+	if wantGoFiles := []string{"file.go", "file_appengine.go"}; !reflect.DeepEqual(pkg.GoFiles, wantGoFiles) {
+		t.Errorf("pkg.GoFiles = %q; want %q", pkg.GoFiles, wantGoFiles)
+	}
+
+	if wantInvalidFiles := []string{"file_appengine.go"}; !reflect.DeepEqual(pkg.InvalidGoFiles, wantInvalidFiles) {
+		t.Errorf("pkg.InvalidGoFiles = %q; want %q", pkg.InvalidGoFiles, wantInvalidFiles)
 	}
 }
 
diff --git a/src/go/build/constraint/expr.go b/src/go/build/constraint/expr.go
index 1ef707ceacf..957eb9b5279 100644
--- a/src/go/build/constraint/expr.go
+++ b/src/go/build/constraint/expr.go
@@ -426,6 +426,9 @@ func parsePlusBuildExpr(text string) Expr {
 			x = or(x, y)
 		}
 	}
+	if x == nil {
+		x = tag("ignore")
+	}
 	return x
 }
 
diff --git a/src/go/build/constraint/expr_test.go b/src/go/build/constraint/expr_test.go
index 4979f8b5f28..15d189012ef 100644
--- a/src/go/build/constraint/expr_test.go
+++ b/src/go/build/constraint/expr_test.go
@@ -216,6 +216,7 @@ var parsePlusBuildExprTests = []struct {
 	{"!!x", tag("ignore")},
 	{"!x", not(tag("x"))},
 	{"!", tag("ignore")},
+	{"", tag("ignore")},
 }
 
 func TestParsePlusBuildExpr(t *testing.T) {
@@ -232,19 +233,22 @@ func TestParsePlusBuildExpr(t *testing.T) {
 var constraintTests = []struct {
 	in  string
 	x   Expr
-	err error
+	err string
 }{
-	{"//+build x y", or(tag("x"), tag("y")), nil},
-	{"// +build x y \n", or(tag("x"), tag("y")), nil},
-	{"// +build x y \n ", nil, errNotConstraint},
-	{"// +build x y \nmore", nil, errNotConstraint},
-	{" //+build x y", nil, errNotConstraint},
+	{"//+build !", tag("ignore"), ""},
+	{"//+build", tag("ignore"), ""},
+	{"//+build x y", or(tag("x"), tag("y")), ""},
+	{"// +build x y \n", or(tag("x"), tag("y")), ""},
+	{"// +build x y \n ", nil, "not a build constraint"},
+	{"// +build x y \nmore", nil, "not a build constraint"},
+	{" //+build x y", nil, "not a build constraint"},
 
-	{"//go:build x && y", and(tag("x"), tag("y")), nil},
-	{"//go:build x && y\n", and(tag("x"), tag("y")), nil},
-	{"//go:build x && y\n ", nil, errNotConstraint},
-	{"//go:build x && y\nmore", nil, errNotConstraint},
-	{" //go:build x && y", nil, errNotConstraint},
+	{"//go:build x && y", and(tag("x"), tag("y")), ""},
+	{"//go:build x && y\n", and(tag("x"), tag("y")), ""},
+	{"//go:build x && y\n ", nil, "not a build constraint"},
+	{"//go:build x && y\nmore", nil, "not a build constraint"},
+	{" //go:build x && y", nil, "not a build constraint"},
+	{"//go:build\n", nil, "unexpected end of expression"},
 }
 
 func TestParse(t *testing.T) {
@@ -252,14 +256,14 @@ func TestParse(t *testing.T) {
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
 			x, err := Parse(tt.in)
 			if err != nil {
-				if tt.err == nil {
+				if tt.err == "" {
 					t.Errorf("Constraint(%q): unexpected error: %v", tt.in, err)
-				} else if tt.err != err {
+				} else if !strings.Contains(err.Error(), tt.err) {
 					t.Errorf("Constraint(%q): error %v, want %v", tt.in, err, tt.err)
 				}
 				return
 			}
-			if tt.err != nil {
+			if tt.err != "" {
 				t.Errorf("Constraint(%q) = %v, want error %v", tt.in, x, tt.err)
 				return
 			}
diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index a2423cf0d93..7e43445a073 100644
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -71,17 +71,19 @@ var depsRules = `
 	# No dependencies allowed for any of these packages.
 	NONE
 	< container/list, container/ring,
-	  internal/cfg, internal/cpu, internal/goexperiment,
+	  internal/cfg, internal/cpu, internal/goarch,
+	  internal/goexperiment, internal/goos,
 	  internal/goversion, internal/nettrace,
 	  unicode/utf8, unicode/utf16, unicode,
 	  unsafe;
 
-	# These packages depend only on unsafe.
-	unsafe
+	# These packages depend only on internal/goarch and unsafe.
+	internal/goarch, unsafe
 	< internal/abi;
 
 	# RUNTIME is the core runtime group of packages, all of them very light-weight.
-	internal/abi, internal/cpu, internal/goexperiment, unsafe
+	internal/abi, internal/cpu, internal/goarch,
+	internal/goexperiment, internal/goos, unsafe
 	< internal/bytealg
 	< internal/itoa
 	< internal/unsafeheader
@@ -395,6 +397,7 @@ var depsRules = `
 	< crypto
 	< crypto/subtle
 	< crypto/internal/subtle
+	< crypto/elliptic/internal/fiat
 	< crypto/ed25519/internal/edwards25519/field
 	< crypto/ed25519/internal/edwards25519
 	< crypto/cipher
@@ -443,7 +446,8 @@ var depsRules = `
 	# HTTP, King of Dependencies.
 
 	FMT
-	< golang.org/x/net/http2/hpack, net/http/internal;
+	< golang.org/x/net/http2/hpack
+	< net/http/internal, net/http/internal/ascii, net/http/internal/testcert;
 
 	FMT, NET, container/list, encoding/binary, log
 	< golang.org/x/text/transform
@@ -461,6 +465,8 @@ var depsRules = `
 	golang.org/x/net/http/httpproxy,
 	golang.org/x/net/http2/hpack,
 	net/http/internal,
+	net/http/internal/ascii,
+	net/http/internal/testcert,
 	net/http/httptrace,
 	mime/multipart,
 	log
@@ -471,7 +477,7 @@ var depsRules = `
 	encoding/json, net/http
 	< expvar;
 
-	net/http
+	net/http, net/http/internal/ascii
 	< net/http/cookiejar, net/http/httputil;
 
 	net/http, flag
diff --git a/src/go/build/doc.go b/src/go/build/doc.go
index 2c6f0a83bea..778b4f40f7c 100644
--- a/src/go/build/doc.go
+++ b/src/go/build/doc.go
@@ -59,7 +59,7 @@
 //
 // A build constraint, also known as a build tag, is a line comment that begins
 //
-// 	// +build
+// 	//go:build
 //
 // that lists the conditions under which a file should be included in the
 // package. Build constraints may also be part of a file's name
diff --git a/src/go/build/read.go b/src/go/build/read.go
index aa7c6ee59eb..b98c7938a85 100644
--- a/src/go/build/read.go
+++ b/src/go/build/read.go
@@ -6,6 +6,7 @@ package build
 
 import (
 	"bufio"
+	"bytes"
 	"errors"
 	"fmt"
 	"go/ast"
@@ -28,9 +29,19 @@ type importReader struct {
 	pos  token.Position
 }
 
+var bom = []byte{0xef, 0xbb, 0xbf}
+
 func newImportReader(name string, r io.Reader) *importReader {
+	b := bufio.NewReader(r)
+	// Remove leading UTF-8 BOM.
+	// Per https://golang.org/ref/spec#Source_code_representation:
+	// a compiler may ignore a UTF-8-encoded byte order mark (U+FEFF)
+	// if it is the first Unicode code point in the source text.
+	if leadingBytes, err := b.Peek(3); err == nil && bytes.Equal(leadingBytes, bom) {
+		b.Discard(3)
+	}
 	return &importReader{
-		b: bufio.NewReader(r),
+		b: b,
 		pos: token.Position{
 			Filename: name,
 			Line:     1,
diff --git a/src/go/build/read_test.go b/src/go/build/read_test.go
index 32e6bae0088..1e5e1c2de2e 100644
--- a/src/go/build/read_test.go
+++ b/src/go/build/read_test.go
@@ -66,6 +66,10 @@ var readGoInfoTests = []readTest{
 		`,
 		"",
 	},
+	{
+		"\ufeff𝔻" + `package p; import "x";ℙvar x = 1`,
+		"",
+	},
 }
 
 var readCommentsTests = []readTest{
@@ -81,6 +85,10 @@ var readCommentsTests = []readTest{
 		`ℙpackage p; import . "x"`,
 		"",
 	},
+	{
+		"\ufeff𝔻" + `ℙpackage p; import . "x"`,
+		"",
+	},
 	{
 		`// foo
 
@@ -90,6 +98,19 @@ var readCommentsTests = []readTest{
 
 		/*/ zot */
 
+		// asdf
+		ℙHello, world`,
+		"",
+	},
+	{
+		"\ufeff𝔻" + `// foo
+
+		/* bar */
+
+		/* quux */ // baz
+
+		/*/ zot */
+
 		// asdf
 		ℙHello, world`,
 		"",
@@ -107,6 +128,11 @@ func testRead(t *testing.T, tests []readTest, read func(io.Reader) ([]byte, erro
 			in = tt.in[:j] + tt.in[j+len("ℙ"):]
 			testOut = tt.in[:j]
 		}
+		d := strings.Index(tt.in, "𝔻")
+		if d >= 0 {
+			in = in[:d] + in[d+len("𝔻"):]
+			testOut = testOut[d+len("𝔻"):]
+		}
 		r := strings.NewReader(in)
 		buf, err := read(r)
 		if err != nil {
@@ -264,6 +290,12 @@ var readEmbedTests = []struct {
 		 test:3:14:y
 		 test:3:16:z`,
 	},
+	{
+		"\ufeffpackage p\nimport \"embed\"\n//go:embed x y z\nvar files embed.FS",
+		`test:3:12:x
+		 test:3:14:y
+		 test:3:16:z`,
+	},
 	{
 		"package p\nimport \"embed\"\nvar s = \"/*\"\n//go:embed x\nvar files embed.FS",
 		`test:4:12:x`,
@@ -292,6 +324,10 @@ var readEmbedTests = []struct {
 		"package p\n//go:embed x y z\nvar files embed.FS", // no import, no scan
 		"",
 	},
+	{
+		"\ufeffpackage p\n//go:embed x y z\nvar files embed.FS", // no import, no scan
+		"",
+	},
 }
 
 func TestReadEmbed(t *testing.T) {
diff --git a/src/go/build/syslist.go b/src/go/build/syslist.go
index 1275f7c986d..60ac5511bda 100644
--- a/src/go/build/syslist.go
+++ b/src/go/build/syslist.go
@@ -8,4 +8,4 @@ package build
 // Do not remove from this list, as these are used for go/build filename matching.
 
 const goosList = "aix android darwin dragonfly freebsd hurd illumos ios js linux nacl netbsd openbsd plan9 solaris windows zos "
-const goarchList = "386 amd64 amd64p32 arm armbe arm64 arm64be ppc64 ppc64le mips mipsle mips64 mips64le mips64p32 mips64p32le ppc riscv riscv64 s390 s390x sparc sparc64 wasm "
+const goarchList = "386 amd64 amd64p32 arm armbe arm64 arm64be ppc64 ppc64le loong64 mips mipsle mips64 mips64le mips64p32 mips64p32le ppc riscv riscv64 s390 s390x sparc sparc64 wasm "
diff --git a/src/go/constant/kind_string.go b/src/go/constant/kind_string.go
new file mode 100644
index 00000000000..700332511d8
--- /dev/null
+++ b/src/go/constant/kind_string.go
@@ -0,0 +1,28 @@
+// Code generated by "stringer -type Kind"; DO NOT EDIT.
+
+package constant
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Unknown-0]
+	_ = x[Bool-1]
+	_ = x[String-2]
+	_ = x[Int-3]
+	_ = x[Float-4]
+	_ = x[Complex-5]
+}
+
+const _Kind_name = "UnknownBoolStringIntFloatComplex"
+
+var _Kind_index = [...]uint8{0, 7, 11, 17, 20, 25, 32}
+
+func (i Kind) String() string {
+	if i < 0 || i >= Kind(len(_Kind_index)-1) {
+		return "Kind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Kind_name[_Kind_index[i]:_Kind_index[i+1]]
+}
diff --git a/src/go/constant/value.go b/src/go/constant/value.go
index 78cb3f896f5..014e873100d 100644
--- a/src/go/constant/value.go
+++ b/src/go/constant/value.go
@@ -24,6 +24,8 @@ import (
 	"unicode/utf8"
 )
 
+//go:generate stringer -type Kind
+
 // Kind specifies the kind of value represented by a Value.
 type Kind int
 
diff --git a/src/go/internal/gcimporter/gcimporter.go b/src/go/internal/gcimporter/gcimporter.go
index b74daca2463..73cf6334fd6 100644
--- a/src/go/internal/gcimporter/gcimporter.go
+++ b/src/go/internal/gcimporter/gcimporter.go
@@ -145,17 +145,14 @@ func Import(fset *token.FileSet, packages map[string]*types.Package, path, srcDi
 		err = fmt.Errorf("import %q: old textual export format no longer supported (recompile library)", path)
 
 	case "$$B\n":
-		var data []byte
-		data, err = io.ReadAll(buf)
-		if err != nil {
-			break
-		}
+		var exportFormat byte
+		exportFormat, err = buf.ReadByte()
 
 		// The indexed export format starts with an 'i'; the older
 		// binary export format starts with a 'c', 'd', or 'v'
 		// (from "version"). Select appropriate importer.
-		if len(data) > 0 && data[0] == 'i' {
-			_, pkg, err = iImportData(fset, packages, data[1:], id)
+		if err == nil && exportFormat == 'i' {
+			pkg, err = iImportData(fset, packages, buf, id)
 		} else {
 			err = fmt.Errorf("import %q: old binary export format no longer supported (recompile library)", path)
 		}
diff --git a/src/go/internal/gcimporter/gcimporter_test.go b/src/go/internal/gcimporter/gcimporter_test.go
index 3c76aafde39..286b8a63471 100644
--- a/src/go/internal/gcimporter/gcimporter_test.go
+++ b/src/go/internal/gcimporter/gcimporter_test.go
@@ -138,6 +138,7 @@ func TestVersionHandling(t *testing.T) {
 	skipSpecialPlatforms(t)
 
 	// This package only handles gc export data.
+	// Disable test until we put in the new export version.
 	if runtime.Compiler != "gc" {
 		t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
 	}
diff --git a/src/go/internal/gcimporter/iimport.go b/src/go/internal/gcimporter/iimport.go
index a3184e7641a..dbc9b3a83e8 100644
--- a/src/go/internal/gcimporter/iimport.go
+++ b/src/go/internal/gcimporter/iimport.go
@@ -8,6 +8,7 @@
 package gcimporter
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/binary"
 	"fmt"
@@ -20,7 +21,7 @@ import (
 )
 
 type intReader struct {
-	*bytes.Reader
+	*bufio.Reader
 	path string
 }
 
@@ -40,6 +41,16 @@ func (r *intReader) uint64() uint64 {
 	return i
 }
 
+// Keep this in sync with constants in iexport.go.
+const (
+	iexportVersionGo1_11 = 0
+	iexportVersionPosCol = 1
+	// TODO: before release, change this back to 2.
+	iexportVersionGenerics = iexportVersionPosCol
+
+	iexportVersionCurrent = iexportVersionGenerics
+)
+
 const predeclReserved = 32
 
 type itag uint64
@@ -55,14 +66,16 @@ const (
 	signatureType
 	structType
 	interfaceType
+	typeParamType
+	instType
 )
 
 // iImportData imports a package from the serialized package data
 // and returns the number of bytes consumed and a reference to the package.
 // If the export data version is not recognized or the format is otherwise
 // compromised, an error is returned.
-func iImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
-	const currentVersion = 1
+func iImportData(fset *token.FileSet, imports map[string]*types.Package, dataReader *bufio.Reader, path string) (pkg *types.Package, err error) {
+	const currentVersion = iexportVersionCurrent
 	version := int64(-1)
 	defer func() {
 		if e := recover(); e != nil {
@@ -74,26 +87,33 @@ func iImportData(fset *token.FileSet, imports map[string]*types.Package, data []
 		}
 	}()
 
-	r := &intReader{bytes.NewReader(data), path}
+	r := &intReader{dataReader, path}
 
 	version = int64(r.uint64())
 	switch version {
-	case currentVersion, 0:
+	case /* iexportVersionGenerics, */ iexportVersionPosCol, iexportVersionGo1_11:
 	default:
-		errorf("unknown iexport format version %d", version)
+		if version > iexportVersionGenerics {
+			errorf("unstable iexport format version %d, just rebuild compiler and std library", version)
+		} else {
+			errorf("unknown iexport format version %d", version)
+		}
 	}
 
 	sLen := int64(r.uint64())
 	dLen := int64(r.uint64())
 
-	whence, _ := r.Seek(0, io.SeekCurrent)
-	stringData := data[whence : whence+sLen]
-	declData := data[whence+sLen : whence+sLen+dLen]
-	r.Seek(sLen+dLen, io.SeekCurrent)
+	data := make([]byte, sLen+dLen)
+	if _, err := io.ReadFull(r, data); err != nil {
+		errorf("cannot read %d bytes of stringData and declData: %s", len(data), err)
+	}
+	stringData := data[:sLen]
+	declData := data[sLen:]
 
 	p := iimporter{
-		ipath:   path,
-		version: int(version),
+		exportVersion: version,
+		ipath:         path,
+		version:       int(version),
 
 		stringData:  stringData,
 		stringCache: make(map[uint64]string),
@@ -165,14 +185,13 @@ func iImportData(fset *token.FileSet, imports map[string]*types.Package, data []
 
 	// package was imported completely and without errors
 	localpkg.MarkComplete()
-
-	consumed, _ := r.Seek(0, io.SeekCurrent)
-	return int(consumed), localpkg, nil
+	return localpkg, nil
 }
 
 type iimporter struct {
-	ipath   string
-	version int
+	exportVersion int64
+	ipath         string
+	version       int
 
 	stringData  []byte
 	stringCache map[uint64]string
@@ -275,6 +294,9 @@ func (r *importReader) obj(name string) {
 
 		r.declare(types.NewFunc(pos, r.currPkg, name, sig))
 
+	case 'G':
+		errorf("unexpected parameterized function/method")
+
 	case 'T':
 		// Types can be recursive. We need to setup a stub
 		// declaration before recursing.
@@ -296,6 +318,9 @@ func (r *importReader) obj(name string) {
 			}
 		}
 
+	case 'U':
+		errorf("unexpected parameterized type")
+
 	case 'V':
 		typ := r.typ()
 
@@ -548,6 +573,14 @@ func (r *importReader) doType(base *types.Named) types.Type {
 		typ := types.NewInterfaceType(methods, embeddeds)
 		r.p.interfaceList = append(r.p.interfaceList, typ)
 		return typ
+
+	case typeParamType:
+		errorf("do not handle type param types yet")
+		return nil
+
+	case instType:
+		errorf("do not handle instantiated types yet")
+		return nil
 	}
 }
 
diff --git a/src/go/internal/gcimporter/support.go b/src/go/internal/gcimporter/support.go
index b8bb14dc490..09810dd85b8 100644
--- a/src/go/internal/gcimporter/support.go
+++ b/src/go/internal/gcimporter/support.go
@@ -122,6 +122,9 @@ var predeclared = []types.Type{
 
 	// used internally by gc; never used by this package or in .a files
 	anyType{},
+
+	// comparable
+	types.Universe.Lookup("comparable").Type(),
 }
 
 type anyType struct{}
diff --git a/src/go/internal/typeparams/notypeparams.go b/src/go/internal/typeparams/notypeparams.go
deleted file mode 100644
index 2ceafaac1c3..00000000000
--- a/src/go/internal/typeparams/notypeparams.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !typeparams
-// +build !typeparams
-
-package typeparams
-
-import (
-	"go/ast"
-)
-
-const Enabled = false
-
-func PackExpr(list []ast.Expr) ast.Expr {
-	switch len(list) {
-	case 1:
-		return list[0]
-	default:
-		// The parser should not attempt to pack multiple expressions into an
-		// IndexExpr if type params are disabled.
-		panic("multiple index expressions are unsupported without type params")
-	}
-}
-
-func UnpackExpr(expr ast.Expr) []ast.Expr {
-	return []ast.Expr{expr}
-}
-
-func IsListExpr(n ast.Node) bool {
-	return false
-}
-
-func Get(ast.Node) *ast.FieldList {
-	return nil
-}
-
-func Set(node ast.Node, params *ast.FieldList) {
-}
diff --git a/src/go/internal/typeparams/typeparams.go b/src/go/internal/typeparams/typeparams.go
index 871e95d9984..3191654d4f8 100644
--- a/src/go/internal/typeparams/typeparams.go
+++ b/src/go/internal/typeparams/typeparams.go
@@ -2,50 +2,59 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build typeparams
-// +build typeparams
-
 package typeparams
 
 import (
 	"fmt"
 	"go/ast"
+	"go/token"
 )
 
-const Enabled = true
-
-func PackExpr(list []ast.Expr) ast.Expr {
-	switch len(list) {
+func PackIndexExpr(x ast.Expr, lbrack token.Pos, exprs []ast.Expr, rbrack token.Pos) ast.Expr {
+	switch len(exprs) {
 	case 0:
-		// Return an empty ListExpr here, rather than nil, as IndexExpr.Index must
-		// never be nil.
-		// TODO(rFindley) would a BadExpr be more appropriate here?
-		return &ast.ListExpr{}
+		panic("internal error: PackIndexExpr with empty expr slice")
 	case 1:
-		return list[0]
+		return &ast.IndexExpr{
+			X:      x,
+			Lbrack: lbrack,
+			Index:  exprs[0],
+			Rbrack: rbrack,
+		}
 	default:
-		return &ast.ListExpr{ElemList: list}
+		return &ast.MultiIndexExpr{
+			X:       x,
+			Lbrack:  lbrack,
+			Indices: exprs,
+			Rbrack:  rbrack,
+		}
 	}
 }
 
-// TODO(gri) Should find a more efficient solution that doesn't
-//           require introduction of a new slice for simple
-//           expressions.
-func UnpackExpr(x ast.Expr) []ast.Expr {
-	if x, _ := x.(*ast.ListExpr); x != nil {
-		return x.ElemList
-	}
-	if x != nil {
-		return []ast.Expr{x}
+// IndexExpr wraps an ast.IndexExpr or ast.MultiIndexExpr into the
+// MultiIndexExpr interface.
+//
+// Orig holds the original ast.Expr from which this IndexExpr was derived.
+type IndexExpr struct {
+	Orig ast.Expr // the wrapped expr, which may be distinct from MultiIndexExpr below.
+	*ast.MultiIndexExpr
+}
+
+func UnpackIndexExpr(n ast.Node) *IndexExpr {
+	switch e := n.(type) {
+	case *ast.IndexExpr:
+		return &IndexExpr{e, &ast.MultiIndexExpr{
+			X:       e.X,
+			Lbrack:  e.Lbrack,
+			Indices: []ast.Expr{e.Index},
+			Rbrack:  e.Rbrack,
+		}}
+	case *ast.MultiIndexExpr:
+		return &IndexExpr{e, e}
 	}
 	return nil
 }
 
-func IsListExpr(n ast.Node) bool {
-	_, ok := n.(*ast.ListExpr)
-	return ok
-}
-
 func Get(n ast.Node) *ast.FieldList {
 	switch n := n.(type) {
 	case *ast.TypeSpec:
diff --git a/src/go/parser/error_test.go b/src/go/parser/error_test.go
index f4f0a5240ac..f35ba0b5017 100644
--- a/src/go/parser/error_test.go
+++ b/src/go/parser/error_test.go
@@ -186,16 +186,14 @@ func TestErrors(t *testing.T) {
 	}
 	for _, d := range list {
 		name := d.Name()
-		if !d.IsDir() && !strings.HasPrefix(name, ".") && (strings.HasSuffix(name, ".src") || strings.HasSuffix(name, ".go2")) {
-			mode := DeclarationErrors | AllErrors
-			if strings.HasSuffix(name, ".go2") {
-				if !typeparams.Enabled {
-					continue
+		t.Run(name, func(t *testing.T) {
+			if !d.IsDir() && !strings.HasPrefix(name, ".") && (strings.HasSuffix(name, ".src") || strings.HasSuffix(name, ".go2")) {
+				mode := DeclarationErrors | AllErrors
+				if !strings.HasSuffix(name, ".go2") {
+					mode |= typeparams.DisallowParsing
 				}
-			} else {
-				mode |= typeparams.DisallowParsing
+				checkErrors(t, filepath.Join(testdata, name), nil, mode, true)
 			}
-			checkErrors(t, filepath.Join(testdata, name), nil, mode, true)
-		}
+		})
 	}
 }
diff --git a/src/go/parser/parser.go b/src/go/parser/parser.go
index 3965641713a..bdc2ad308c8 100644
--- a/src/go/parser/parser.go
+++ b/src/go/parser/parser.go
@@ -77,7 +77,7 @@ func (p *parser) init(fset *token.FileSet, filename string, src []byte, mode Mod
 }
 
 func (p *parser) parseTypeParams() bool {
-	return typeparams.Enabled && p.mode&typeparams.DisallowParsing == 0
+	return p.mode&typeparams.DisallowParsing == 0
 }
 
 // ----------------------------------------------------------------------------
@@ -600,7 +600,7 @@ func (p *parser) parseArrayFieldOrTypeInstance(x *ast.Ident) (*ast.Ident, ast.Ex
 	}
 
 	// x[P], x[P1, P2], ...
-	return nil, &ast.IndexExpr{X: x, Lbrack: lbrack, Index: typeparams.PackExpr(args), Rbrack: rbrack}
+	return nil, typeparams.PackIndexExpr(x, lbrack, args, rbrack)
 }
 
 func (p *parser) parseFieldDecl() *ast.Field {
@@ -980,6 +980,7 @@ func (p *parser) parseMethodSpec() *ast.Field {
 				list := []ast.Expr{x}
 				if p.atComma("type argument list", token.RBRACK) {
 					p.exprLev++
+					p.next()
 					for p.tok != token.RBRACK && p.tok != token.EOF {
 						list = append(list, p.parseType())
 						if !p.atComma("type argument list", token.RBRACK) {
@@ -990,7 +991,7 @@ func (p *parser) parseMethodSpec() *ast.Field {
 					p.exprLev--
 				}
 				rbrack := p.expectClosing(token.RBRACK, "type argument list")
-				typ = &ast.IndexExpr{X: ident, Lbrack: lbrack, Index: typeparams.PackExpr(list), Rbrack: rbrack}
+				typ = typeparams.PackIndexExpr(ident, lbrack, list, rbrack)
 			}
 		case p.tok == token.LPAREN:
 			// ordinary method
@@ -1011,11 +1012,56 @@ func (p *parser) parseMethodSpec() *ast.Field {
 			typ = p.parseTypeInstance(typ)
 		}
 	}
-	p.expectSemi() // call before accessing p.linecomment
 
-	spec := &ast.Field{Doc: doc, Names: idents, Type: typ, Comment: p.lineComment}
+	// Comment is added at the callsite: the field below may joined with
+	// additional type specs using '|'.
+	// TODO(rfindley) this should be refactored.
+	// TODO(rfindley) add more tests for comment handling.
+	return &ast.Field{Doc: doc, Names: idents, Type: typ}
+}
 
-	return spec
+func (p *parser) embeddedElem(f *ast.Field) *ast.Field {
+	if p.trace {
+		defer un(trace(p, "EmbeddedElem"))
+	}
+	if f == nil {
+		f = new(ast.Field)
+		f.Type = p.embeddedTerm()
+	}
+	for p.tok == token.OR {
+		t := new(ast.BinaryExpr)
+		t.OpPos = p.pos
+		t.Op = token.OR
+		p.next()
+		t.X = f.Type
+		t.Y = p.embeddedTerm()
+		f.Type = t
+	}
+	return f
+}
+
+func (p *parser) embeddedTerm() ast.Expr {
+	if p.trace {
+		defer un(trace(p, "EmbeddedTerm"))
+	}
+	if p.tok == token.TILDE {
+		t := new(ast.UnaryExpr)
+		t.OpPos = p.pos
+		t.Op = token.TILDE
+		p.next()
+		t.X = p.parseType()
+		return t
+	}
+
+	t := p.tryIdentOrType()
+	if t == nil {
+		pos := p.pos
+		p.errorExpected(pos, "~ term or type")
+		p.advance(exprEnd)
+		return &ast.BadExpr{From: pos, To: p.pos}
+	}
+
+	return t
 }
 
 func (p *parser) parseInterfaceType() *ast.InterfaceType {
@@ -1025,11 +1071,28 @@ func (p *parser) parseInterfaceType() *ast.InterfaceType {
 
 	pos := p.expect(token.INTERFACE)
 	lbrace := p.expect(token.LBRACE)
+
 	var list []*ast.Field
-	for p.tok == token.IDENT || p.parseTypeParams() && p.tok == token.TYPE {
-		if p.tok == token.IDENT {
-			list = append(list, p.parseMethodSpec())
-		} else {
+
+parseElements:
+	for {
+		switch {
+		case p.tok == token.IDENT:
+			f := p.parseMethodSpec()
+			if f.Names == nil && p.parseTypeParams() {
+				f = p.embeddedElem(f)
+			}
+			p.expectSemi()
+			f.Comment = p.lineComment
+			list = append(list, f)
+		case p.tok == token.TILDE && p.parseTypeParams():
+			f := p.embeddedElem(nil)
+			p.expectSemi()
+			f.Comment = p.lineComment
+			list = append(list, f)
+		case p.tok == token.TYPE && p.parseTypeParams():
+			// TODO(rfindley): remove TypeList syntax and refactor the clauses above.
+
 			// all types in a type list share the same field name "type"
 			// (since type is a keyword, a Go program cannot have that field name)
 			name := []*ast.Ident{{NamePos: p.pos, Name: "type"}}
@@ -1039,8 +1102,22 @@ func (p *parser) parseInterfaceType() *ast.InterfaceType {
 				list = append(list, &ast.Field{Names: name, Type: typ})
 			}
 			p.expectSemi()
+		case p.parseTypeParams():
+			if t := p.tryIdentOrType(); t != nil {
+				f := new(ast.Field)
+				f.Type = t
+				f = p.embeddedElem(f)
+				p.expectSemi()
+				f.Comment = p.lineComment
+				list = append(list, f)
+			} else {
+				break parseElements
+			}
+		default:
+			break parseElements
 		}
 	}
+
 	// TODO(rfindley): the error produced here could be improved, since we could
 	// accept a identifier, 'type', or a '}' at this point.
 	rbrace := p.expect(token.RBRACE)
@@ -1101,7 +1178,6 @@ func (p *parser) parseTypeInstance(typ ast.Expr) ast.Expr {
 	}
 
 	opening := p.expect(token.LBRACK)
-
 	p.exprLev++
 	var list []ast.Expr
 	for p.tok != token.RBRACK && p.tok != token.EOF {
@@ -1115,7 +1191,17 @@ func (p *parser) parseTypeInstance(typ ast.Expr) ast.Expr {
 
 	closing := p.expectClosing(token.RBRACK, "type argument list")
 
-	return &ast.IndexExpr{X: typ, Lbrack: opening, Index: typeparams.PackExpr(list), Rbrack: closing}
+	if len(list) == 0 {
+		p.errorExpected(closing, "type argument list")
+		return &ast.IndexExpr{
+			X:      typ,
+			Lbrack: opening,
+			Index:  &ast.BadExpr{From: opening + 1, To: closing},
+			Rbrack: closing,
+		}
+	}
+
+	return typeparams.PackIndexExpr(typ, opening, list, closing)
 }
 
 func (p *parser) tryIdentOrType() ast.Expr {
@@ -1302,7 +1388,12 @@ func (p *parser) parseIndexOrSliceOrInstance(x ast.Expr) ast.Expr {
 		p.errorExpected(p.pos, "operand")
 		rbrack := p.pos
 		p.next()
-		return &ast.BadExpr{From: x.Pos(), To: rbrack}
+		return &ast.IndexExpr{
+			X:      x,
+			Lbrack: lbrack,
+			Index:  &ast.BadExpr{From: rbrack, To: rbrack},
+			Rbrack: rbrack,
+		}
 	}
 	p.exprLev++
 
@@ -1373,7 +1464,7 @@ func (p *parser) parseIndexOrSliceOrInstance(x ast.Expr) ast.Expr {
 	}
 
 	// instance expression
-	return &ast.IndexExpr{X: x, Lbrack: lbrack, Index: typeparams.PackExpr(args), Rbrack: rbrack}
+	return typeparams.PackIndexExpr(x, lbrack, args, rbrack)
 }
 
 func (p *parser) parseCallOrConversion(fun ast.Expr) *ast.CallExpr {
@@ -1475,6 +1566,7 @@ func (p *parser) checkExpr(x ast.Expr) ast.Expr {
 		panic("unreachable")
 	case *ast.SelectorExpr:
 	case *ast.IndexExpr:
+	case *ast.MultiIndexExpr:
 	case *ast.SliceExpr:
 	case *ast.TypeAssertExpr:
 		// If t.Type == nil we have a type assertion of the form
@@ -1564,7 +1656,7 @@ func (p *parser) parsePrimaryExpr() (x ast.Expr) {
 					return
 				}
 				// x is possibly a composite literal type
-			case *ast.IndexExpr:
+			case *ast.IndexExpr, *ast.MultiIndexExpr:
 				if p.exprLev < 0 {
 					return
 				}
diff --git a/src/go/parser/resolver_test.go b/src/go/parser/resolver_test.go
index 625c009c914..0c06c592d5f 100644
--- a/src/go/parser/resolver_test.go
+++ b/src/go/parser/resolver_test.go
@@ -41,11 +41,7 @@ func TestResolution(t *testing.T) {
 			path := filepath.Join(dir, fi.Name())
 			src := readFile(path) // panics on failure
 			var mode Mode
-			if strings.HasSuffix(path, ".go2") {
-				if !typeparams.Enabled {
-					t.Skip("type params are not enabled")
-				}
-			} else {
+			if !strings.HasSuffix(path, ".go2") {
 				mode |= typeparams.DisallowParsing
 			}
 			file, err := ParseFile(fset, path, src, mode)
diff --git a/src/go/parser/short_test.go b/src/go/parser/short_test.go
index 67fef156655..bfc6f6714b9 100644
--- a/src/go/parser/short_test.go
+++ b/src/go/parser/short_test.go
@@ -133,9 +133,6 @@ func TestValid(t *testing.T) {
 		}
 	})
 	t.Run("tparams", func(t *testing.T) {
-		if !typeparams.Enabled {
-			t.Skip("type params are not enabled")
-		}
 		for _, src := range valids {
 			checkErrors(t, src, src, DeclarationErrors|AllErrors, false)
 		}
@@ -200,10 +197,12 @@ var invalids = []string{
 	`package p; func (type /* ERROR "found 'type'" */ T)(T) _()`,
 	`package p; type _[A+B, /* ERROR "expected ']'" */ ] int`,
 
-	// TODO: this error should be positioned on the ':'
+	// TODO(rfindley): this error should be positioned on the ':'
 	`package p; var a = a[[]int:[ /* ERROR "expected expression" */ ]int];`,
-	// TODO: the compiler error is better here: "cannot parenthesize embedded type"
-	`package p; type I1 interface{}; type I2 interface{ (/* ERROR "expected '}', found '\('" */ I1) }`,
+
+	// TODO(rfindley): the compiler error is better here: "cannot parenthesize embedded type"
+	// TODO(rfindley): confirm that parenthesized types should now be accepted.
+	// `package p; type I1 interface{}; type I2 interface{ (/* ERROR "expected '}', found '\('" */ I1) }`,
 
 	// issue 8656
 	`package p; func f() (a b string /* ERROR "missing ','" */ , ok bool)`,
@@ -266,9 +265,6 @@ func TestInvalid(t *testing.T) {
 		}
 	})
 	t.Run("tparams", func(t *testing.T) {
-		if !typeparams.Enabled {
-			t.Skip("type params are not enabled")
-		}
 		for _, src := range invalids {
 			checkErrors(t, src, src, DeclarationErrors|AllErrors, true)
 		}
diff --git a/src/go/parser/testdata/interface.go2 b/src/go/parser/testdata/interface.go2
new file mode 100644
index 00000000000..b399d751488
--- /dev/null
+++ b/src/go/parser/testdata/interface.go2
@@ -0,0 +1,80 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains test cases for interfaces containing
+// constraint elements.
+//
+// For now, we accept both ordinary type lists and the
+// more complex constraint elements.
+
+package p
+
+type _ interface {
+	m()
+	type int
+	type int, string
+	E
+}
+
+type _ interface {
+	m()
+	~int
+	int | string
+	int | ~string
+	~int | ~string
+}
+
+type _ interface {
+	m()
+	~int
+	T[int, string] | string
+	int | ~T[string, struct{}]
+	~int | ~string
+	type bool, int, float64
+}
+
+type _ interface {
+	int
+	[]byte
+	[10]int
+	struct{}
+	*int
+	func()
+	interface{}
+	map[string]int
+	chan T
+	chan<- T
+	<-chan T
+	T[int]
+}
+
+type _ interface {
+	int | string
+	[]byte | string
+	[10]int | string
+	struct{} | string
+	*int | string
+	func() | string
+	interface{} | string
+	map[string]int | string
+	chan T | string
+	chan<- T | string
+	<-chan T | string
+	T[int] | string
+}
+
+type _ interface {
+	~int | string
+	~[]byte | string
+	~[10]int | string
+	~struct{} | string
+	~*int | string
+	~func() | string
+	~interface{} | string
+	~map[string]int | string
+	~chan T | string
+	~chan<- T | string
+	~<-chan T | string
+	~T[int] | string
+}
diff --git a/src/go/printer/nodes.go b/src/go/printer/nodes.go
index 913281ea6c1..239fcbde1c8 100644
--- a/src/go/printer/nodes.go
+++ b/src/go/printer/nodes.go
@@ -871,17 +871,15 @@ func (p *printer) expr1(expr ast.Expr, prec1, depth int) {
 		// TODO(gri): should treat[] like parentheses and undo one level of depth
 		p.expr1(x.X, token.HighestPrec, 1)
 		p.print(x.Lbrack, token.LBRACK)
-		// Note: we're a bit defensive here to handle the case of a ListExpr of
-		// length 1.
-		if list := typeparams.UnpackExpr(x.Index); len(list) > 0 {
-			if len(list) > 1 {
-				p.exprList(x.Lbrack, list, depth+1, commaTerm, x.Rbrack, false)
-			} else {
-				p.expr0(list[0], depth+1)
-			}
-		} else {
-			p.expr0(x.Index, depth+1)
-		}
+		p.expr0(x.Index, depth+1)
+		p.print(x.Rbrack, token.RBRACK)
+
+	case *ast.MultiIndexExpr:
+		// TODO(gri): as for IndexExpr, should treat [] like parentheses and undo
+		// one level of depth
+		p.expr1(x.X, token.HighestPrec, 1)
+		p.print(x.Lbrack, token.LBRACK)
+		p.exprList(x.Lbrack, x.Indices, depth+1, commaTerm, x.Rbrack, false)
 		p.print(x.Rbrack, token.RBRACK)
 
 	case *ast.SliceExpr:
diff --git a/src/go/printer/printer_test.go b/src/go/printer/printer_test.go
index 20c97b8c081..ff8be4ae97a 100644
--- a/src/go/printer/printer_test.go
+++ b/src/go/printer/printer_test.go
@@ -10,7 +10,6 @@ import (
 	"flag"
 	"fmt"
 	"go/ast"
-	"go/internal/typeparams"
 	"go/parser"
 	"go/token"
 	"io"
@@ -222,9 +221,6 @@ var data = []entry{
 func TestFiles(t *testing.T) {
 	t.Parallel()
 	for _, e := range data {
-		if !typeparams.Enabled && e.mode&allowTypeParams != 0 {
-			continue
-		}
 		source := filepath.Join(dataDir, e.source)
 		golden := filepath.Join(dataDir, e.golden)
 		mode := e.mode
diff --git a/src/go/scanner/scanner.go b/src/go/scanner/scanner.go
index 29cbf39721f..ca4b5264cfe 100644
--- a/src/go/scanner/scanner.go
+++ b/src/go/scanner/scanner.go
@@ -373,7 +373,7 @@ func (s *Scanner) scanIdentifier() string {
 			continue
 		}
 		s.rdOffset += rdOffset
-		if b < utf8.RuneSelf {
+		if 0 < b && b < utf8.RuneSelf {
 			// Optimization: we've encountered an ASCII character that's not a letter
 			// or number. Avoid the call into s.next() and corresponding set up.
 			//
@@ -969,6 +969,8 @@ scanAgain:
 			}
 		case '|':
 			tok = s.switch3(token.OR, token.OR_ASSIGN, '|', token.LOR)
+		case '~':
+			tok = token.TILDE
 		default:
 			// next reports unexpected BOMs - don't repeat
 			if ch != bom {
diff --git a/src/go/scanner/scanner_test.go b/src/go/scanner/scanner_test.go
index ac8d2577169..de45e166060 100644
--- a/src/go/scanner/scanner_test.go
+++ b/src/go/scanner/scanner_test.go
@@ -40,7 +40,7 @@ type elt struct {
 	class int
 }
 
-var tokens = [...]elt{
+var tokens = []elt{
 	// Special tokens
 	{token.COMMENT, "/* a comment */", special},
 	{token.COMMENT, "// a comment \n", special},
@@ -149,6 +149,7 @@ var tokens = [...]elt{
 	{token.RBRACE, "}", operator},
 	{token.SEMICOLON, ";", operator},
 	{token.COLON, ":", operator},
+	{token.TILDE, "~", operator},
 
 	// Keywords
 	{token.BREAK, "break", keyword},
@@ -812,6 +813,8 @@ var errors = []struct {
 	{"//\ufeff", token.COMMENT, 2, "//\ufeff", "illegal byte order mark"},                                // only first BOM is ignored
 	{"'\ufeff" + `'`, token.CHAR, 1, "'\ufeff" + `'`, "illegal byte order mark"},                         // only first BOM is ignored
 	{`"` + "abc\ufeffdef" + `"`, token.STRING, 4, `"` + "abc\ufeffdef" + `"`, "illegal byte order mark"}, // only first BOM is ignored
+	{"abc\x00def", token.IDENT, 3, "abc", "illegal character NUL"},
+	{"abc\x00", token.IDENT, 3, "abc", "illegal character NUL"},
 }
 
 func TestScanErrors(t *testing.T) {
diff --git a/src/go/token/position.go b/src/go/token/position.go
index bbcd8b022b6..0d7982c6705 100644
--- a/src/go/token/position.go
+++ b/src/go/token/position.go
@@ -278,7 +278,7 @@ func (f *File) Pos(offset int) Pos {
 //
 func (f *File) Offset(p Pos) int {
 	if int(p) < f.base || int(p) > f.base+f.size {
-		panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+		panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d])", p, f.base, f.base+f.size))
 	}
 	return int(p) - f.base
 }
@@ -346,7 +346,7 @@ func (f *File) position(p Pos, adjusted bool) (pos Position) {
 func (f *File) PositionFor(p Pos, adjusted bool) (pos Position) {
 	if p != NoPos {
 		if int(p) < f.base || int(p) > f.base+f.size {
-			panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+			panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d])", p, f.base, f.base+f.size))
 		}
 		pos = f.position(p, adjusted)
 	}
diff --git a/src/go/token/token.go b/src/go/token/token.go
index 96a1079ec37..d22e575661a 100644
--- a/src/go/token/token.go
+++ b/src/go/token/token.go
@@ -125,6 +125,11 @@ const (
 	TYPE
 	VAR
 	keyword_end
+
+	additional_beg
+	// additional tokens, handled in an ad-hoc manner
+	TILDE
+	additional_end
 )
 
 var tokens = [...]string{
@@ -225,6 +230,8 @@ var tokens = [...]string{
 	SWITCH: "switch",
 	TYPE:   "type",
 	VAR:    "var",
+
+	TILDE: "~",
 }
 
 // String returns the string corresponding to the token tok.
@@ -304,7 +311,9 @@ func (tok Token) IsLiteral() bool { return literal_beg < tok && tok < literal_en
 // IsOperator returns true for tokens corresponding to operators and
 // delimiters; it returns false otherwise.
 //
-func (tok Token) IsOperator() bool { return operator_beg < tok && tok < operator_end }
+func (tok Token) IsOperator() bool {
+	return (operator_beg < tok && tok < operator_end) || tok == TILDE
+}
 
 // IsKeyword returns true for tokens corresponding to keywords;
 // it returns false otherwise.
diff --git a/src/go/types/api.go b/src/go/types/api.go
index ed62a785d6c..315f77f362a 100644
--- a/src/go/types/api.go
+++ b/src/go/types/api.go
@@ -34,6 +34,8 @@ import (
 	"go/token"
 )
 
+const allowTypeLists = false
+
 // An Error describes a type-checking error; it implements the error interface.
 // A "soft" error is an error that still permits a valid interpretation of a
 // package (such as "unused variable"); "hard" errors may lead to unpredictable
@@ -160,7 +162,101 @@ func srcimporter_setUsesCgo(conf *Config) {
 	conf.go115UsesCgo = true
 }
 
-// The Info struct is found in api_notypeparams.go and api_typeparams.go.
+// Info holds result type information for a type-checked package.
+// Only the information for which a map is provided is collected.
+// If the package has type errors, the collected information may
+// be incomplete.
+type Info struct {
+	// Types maps expressions to their types, and for constant
+	// expressions, also their values. Invalid expressions are
+	// omitted.
+	//
+	// For (possibly parenthesized) identifiers denoting built-in
+	// functions, the recorded signatures are call-site specific:
+	// if the call result is not a constant, the recorded type is
+	// an argument-specific signature. Otherwise, the recorded type
+	// is invalid.
+	//
+	// The Types map does not record the type of every identifier,
+	// only those that appear where an arbitrary expression is
+	// permitted. For instance, the identifier f in a selector
+	// expression x.f is found only in the Selections map, the
+	// identifier z in a variable declaration 'var z int' is found
+	// only in the Defs map, and identifiers denoting packages in
+	// qualified identifiers are collected in the Uses map.
+	Types map[ast.Expr]TypeAndValue
+
+	// Inferred maps calls of parameterized functions that use
+	// type inference to the inferred type arguments and signature
+	// of the function called. The recorded "call" expression may be
+	// an *ast.CallExpr (as in f(x)), or an *ast.IndexExpr (s in f[T]).
+	Inferred map[ast.Expr]Inferred
+
+	// Defs maps identifiers to the objects they define (including
+	// package names, dots "." of dot-imports, and blank "_" identifiers).
+	// For identifiers that do not denote objects (e.g., the package name
+	// in package clauses, or symbolic variables t in t := x.(type) of
+	// type switch headers), the corresponding objects are nil.
+	//
+	// For an embedded field, Defs returns the field *Var it defines.
+	//
+	// Invariant: Defs[id] == nil || Defs[id].Pos() == id.Pos()
+	Defs map[*ast.Ident]Object
+
+	// Uses maps identifiers to the objects they denote.
+	//
+	// For an embedded field, Uses returns the *TypeName it denotes.
+	//
+	// Invariant: Uses[id].Pos() != id.Pos()
+	Uses map[*ast.Ident]Object
+
+	// Implicits maps nodes to their implicitly declared objects, if any.
+	// The following node and object types may appear:
+	//
+	//     node               declared object
+	//
+	//     *ast.ImportSpec    *PkgName for imports without renames
+	//     *ast.CaseClause    type-specific *Var for each type switch case clause (incl. default)
+	//     *ast.Field         anonymous parameter *Var (incl. unnamed results)
+	//
+	Implicits map[ast.Node]Object
+
+	// Selections maps selector expressions (excluding qualified identifiers)
+	// to their corresponding selections.
+	Selections map[*ast.SelectorExpr]*Selection
+
+	// Scopes maps ast.Nodes to the scopes they define. Package scopes are not
+	// associated with a specific node but with all files belonging to a package.
+	// Thus, the package scope can be found in the type-checked Package object.
+	// Scopes nest, with the Universe scope being the outermost scope, enclosing
+	// the package scope, which contains (one or more) files scopes, which enclose
+	// function scopes which in turn enclose statement and function literal scopes.
+	// Note that even though package-level functions are declared in the package
+	// scope, the function scopes are embedded in the file scope of the file
+	// containing the function declaration.
+	//
+	// The following node types may appear in Scopes:
+	//
+	//     *ast.File
+	//     *ast.FuncType
+	//     *ast.BlockStmt
+	//     *ast.IfStmt
+	//     *ast.SwitchStmt
+	//     *ast.TypeSwitchStmt
+	//     *ast.CaseClause
+	//     *ast.CommClause
+	//     *ast.ForStmt
+	//     *ast.RangeStmt
+	//
+	Scopes map[ast.Node]*Scope
+
+	// InitOrder is the list of package-level initializers in the order in which
+	// they must be executed. Initializers referring to variables related by an
+	// initialization dependency appear in topological order, the others appear
+	// in source order. Variables without an initialization expression do not
+	// appear in this list.
+	InitOrder []*Initializer
+}
 
 // TypeOf returns the type of expression e, or nil if not found.
 // Precondition: the Types, Uses and Defs maps are populated.
@@ -252,10 +348,10 @@ func (tv TypeAndValue) HasOk() bool {
 	return tv.mode == commaok || tv.mode == mapindex
 }
 
-// _Inferred reports the _Inferred type arguments and signature
+// Inferred reports the Inferred type arguments and signature
 // for a parameterized function call that uses type inference.
-type _Inferred struct {
-	Targs []Type
+type Inferred struct {
+	TArgs []Type
 	Sig   *Signature
 }
 
@@ -324,11 +420,11 @@ func Implements(V Type, T *Interface) bool {
 // Identical reports whether x and y are identical types.
 // Receivers of Signature types are ignored.
 func Identical(x, y Type) bool {
-	return (*Checker)(nil).identical(x, y)
+	return identical(x, y, true, nil)
 }
 
 // IdenticalIgnoreTags reports whether x and y are identical types if tags are ignored.
 // Receivers of Signature types are ignored.
 func IdenticalIgnoreTags(x, y Type) bool {
-	return (*Checker)(nil).identicalIgnoreTags(x, y)
+	return identical(x, y, false, nil)
 }
diff --git a/src/go/types/api_notypeparams.go b/src/go/types/api_notypeparams.go
deleted file mode 100644
index 9f7cb7eccf2..00000000000
--- a/src/go/types/api_notypeparams.go
+++ /dev/null
@@ -1,104 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !typeparams
-// +build !typeparams
-
-package types
-
-import "go/ast"
-
-// Info holds result type information for a type-checked package.
-// Only the information for which a map is provided is collected.
-// If the package has type errors, the collected information may
-// be incomplete.
-type Info struct {
-	// Types maps expressions to their types, and for constant
-	// expressions, also their values. Invalid expressions are
-	// omitted.
-	//
-	// For (possibly parenthesized) identifiers denoting built-in
-	// functions, the recorded signatures are call-site specific:
-	// if the call result is not a constant, the recorded type is
-	// an argument-specific signature. Otherwise, the recorded type
-	// is invalid.
-	//
-	// The Types map does not record the type of every identifier,
-	// only those that appear where an arbitrary expression is
-	// permitted. For instance, the identifier f in a selector
-	// expression x.f is found only in the Selections map, the
-	// identifier z in a variable declaration 'var z int' is found
-	// only in the Defs map, and identifiers denoting packages in
-	// qualified identifiers are collected in the Uses map.
-	Types map[ast.Expr]TypeAndValue
-
-	// Defs maps identifiers to the objects they define (including
-	// package names, dots "." of dot-imports, and blank "_" identifiers).
-	// For identifiers that do not denote objects (e.g., the package name
-	// in package clauses, or symbolic variables t in t := x.(type) of
-	// type switch headers), the corresponding objects are nil.
-	//
-	// For an embedded field, Defs returns the field *Var it defines.
-	//
-	// Invariant: Defs[id] == nil || Defs[id].Pos() == id.Pos()
-	Defs map[*ast.Ident]Object
-
-	// Uses maps identifiers to the objects they denote.
-	//
-	// For an embedded field, Uses returns the *TypeName it denotes.
-	//
-	// Invariant: Uses[id].Pos() != id.Pos()
-	Uses map[*ast.Ident]Object
-
-	// Implicits maps nodes to their implicitly declared objects, if any.
-	// The following node and object types may appear:
-	//
-	//     node               declared object
-	//
-	//     *ast.ImportSpec    *PkgName for imports without renames
-	//     *ast.CaseClause    type-specific *Var for each type switch case clause (incl. default)
-	//     *ast.Field         anonymous parameter *Var (incl. unnamed results)
-	//
-	Implicits map[ast.Node]Object
-
-	// Selections maps selector expressions (excluding qualified identifiers)
-	// to their corresponding selections.
-	Selections map[*ast.SelectorExpr]*Selection
-
-	// Scopes maps ast.Nodes to the scopes they define. Package scopes are not
-	// associated with a specific node but with all files belonging to a package.
-	// Thus, the package scope can be found in the type-checked Package object.
-	// Scopes nest, with the Universe scope being the outermost scope, enclosing
-	// the package scope, which contains (one or more) files scopes, which enclose
-	// function scopes which in turn enclose statement and function literal scopes.
-	// Note that even though package-level functions are declared in the package
-	// scope, the function scopes are embedded in the file scope of the file
-	// containing the function declaration.
-	//
-	// The following node types may appear in Scopes:
-	//
-	//     *ast.File
-	//     *ast.FuncType
-	//     *ast.BlockStmt
-	//     *ast.IfStmt
-	//     *ast.SwitchStmt
-	//     *ast.TypeSwitchStmt
-	//     *ast.CaseClause
-	//     *ast.CommClause
-	//     *ast.ForStmt
-	//     *ast.RangeStmt
-	//
-	Scopes map[ast.Node]*Scope
-
-	// InitOrder is the list of package-level initializers in the order in which
-	// they must be executed. Initializers referring to variables related by an
-	// initialization dependency appear in topological order, the others appear
-	// in source order. Variables without an initialization expression do not
-	// appear in this list.
-	InitOrder []*Initializer
-}
-
-func getInferred(info *Info) map[ast.Expr]_Inferred {
-	return nil
-}
diff --git a/src/go/types/api_test.go b/src/go/types/api_test.go
index f37b91d5a4e..f138af5fbf5 100644
--- a/src/go/types/api_test.go
+++ b/src/go/types/api_test.go
@@ -322,6 +322,18 @@ func TestTypesInfo(t *testing.T) {
 			`[][]struct{}`,
 		},
 
+		// issue 47243
+		{`package issue47243_a; var x int32; var _ = x << 3`, `3`, `untyped int`},
+		{`package issue47243_b; var x int32; var _ = x << 3.`, `3.`, `uint`}, // issue 47410: should be untyped float
+		{`package issue47243_c; var x int32; var _ = 1 << x`, `1 << x`, `int`},
+		{`package issue47243_d; var x int32; var _ = 1 << x`, `1`, `int`},
+		{`package issue47243_e; var x int32; var _ = 1 << 2`, `1`, `untyped int`},
+		{`package issue47243_f; var x int32; var _ = 1 << 2`, `2`, `untyped int`},
+		{`package issue47243_g; var x int32; var _ = int(1) << 2`, `2`, `untyped int`},
+		{`package issue47243_h; var x int32; var _ = 1 << (2 << x)`, `1`, `int`},
+		{`package issue47243_i; var x int32; var _ = 1 << (2 << x)`, `(2 << x)`, `untyped int`},
+		{`package issue47243_j; var x int32; var _ = 1 << (2 << x)`, `2`, `untyped int`},
+
 		// tests for broken code that doesn't parse or type-check
 		{broken + `x0; func _() { var x struct {f string}; x.f := 0 }`, `x.f`, `string`},
 		{broken + `x1; func _() { var z string; type x struct {f string}; y := &x{q: z}}`, `z`, `string`},
@@ -331,16 +343,16 @@ func TestTypesInfo(t *testing.T) {
 		{broken + `x5; func _() { var x map[string][...]int; x = map[string][...]int{"": {1,2,3}} }`, `x`, `map[string][-1]int`},
 
 		// parameterized functions
-		{genericPkg + `p0; func f[T any](T); var _ = f[int]`, `f`, `func[T₁ interface{}](T₁)`},
+		{genericPkg + `p0; func f[T any](T); var _ = f[int]`, `f`, `func[generic_p0.T₁ interface{}](generic_p0.T₁)`},
 		{genericPkg + `p1; func f[T any](T); var _ = f[int]`, `f[int]`, `func(int)`},
-		{genericPkg + `p2; func f[T any](T); func _() { f(42) }`, `f`, `func[T₁ interface{}](T₁)`},
+		{genericPkg + `p2; func f[T any](T); func _() { f(42) }`, `f`, `func[generic_p2.T₁ interface{}](generic_p2.T₁)`},
 		{genericPkg + `p3; func f[T any](T); func _() { f(42) }`, `f(42)`, `()`},
 
 		// type parameters
 		{genericPkg + `t0; type t[] int; var _ t`, `t`, `generic_t0.t`}, // t[] is a syntax error that is ignored in this test in favor of t
-		{genericPkg + `t1; type t[P any] int; var _ t[int]`, `t`, `generic_t1.t[P₁ interface{}]`},
-		{genericPkg + `t2; type t[P interface{}] int; var _ t[int]`, `t`, `generic_t2.t[P₁ interface{}]`},
-		{genericPkg + `t3; type t[P, Q interface{}] int; var _ t[int, int]`, `t`, `generic_t3.t[P₁, Q₂ interface{}]`},
+		{genericPkg + `t1; type t[P any] int; var _ t[int]`, `t`, `generic_t1.t[generic_t1.P₁ interface{}]`},
+		{genericPkg + `t2; type t[P interface{}] int; var _ t[int]`, `t`, `generic_t2.t[generic_t2.P₁ interface{}]`},
+		{genericPkg + `t3; type t[P, Q interface{}] int; var _ t[int, int]`, `t`, `generic_t3.t[generic_t3.P₁, generic_t3.Q₂ interface{}]`},
 
 		// TODO (rFindley): compare with types2, which resolves the type broken_t4.t[P₁, Q₂ interface{m()}] here
 		{broken + `t4; type t[P, Q interface{ m() }] int; var _ t[int, int]`, `t`, `broken_t4.t`},
@@ -349,14 +361,10 @@ func TestTypesInfo(t *testing.T) {
 		{genericPkg + `g0; type t[P any] int; var x struct{ f t[int] }; var _ = x.f`, `x.f`, `generic_g0.t[int]`},
 
 		// issue 45096
-		{genericPkg + `issue45096; func _[T interface{ type int8, int16, int32  }](x T) { _ = x < 0 }`, `0`, `T₁`},
+		{genericPkg + `issue45096; func _[T interface{ ~int8 | ~int16 | ~int32  }](x T) { _ = x < 0 }`, `0`, `generic_issue45096.T₁`},
 	}
 
 	for _, test := range tests {
-		ResetId() // avoid renumbering of type parameter ids when adding tests
-		if strings.HasPrefix(test.src, genericPkg) && !typeparams.Enabled {
-			continue
-		}
 		info := Info{Types: make(map[ast.Expr]TypeAndValue)}
 		var name string
 		if strings.HasPrefix(test.src, broken) {
@@ -390,6 +398,129 @@ func TestTypesInfo(t *testing.T) {
 	}
 }
 
+func TestInferredInfo(t *testing.T) {
+	var tests = []struct {
+		src   string
+		fun   string
+		targs []string
+		sig   string
+	}{
+		{genericPkg + `p0; func f[T any](T); func _() { f(42) }`,
+			`f`,
+			[]string{`int`},
+			`func(int)`,
+		},
+		{genericPkg + `p1; func f[T any](T) T; func _() { f('@') }`,
+			`f`,
+			[]string{`rune`},
+			`func(rune) rune`,
+		},
+		{genericPkg + `p2; func f[T any](...T) T; func _() { f(0i) }`,
+			`f`,
+			[]string{`complex128`},
+			`func(...complex128) complex128`,
+		},
+		{genericPkg + `p3; func f[A, B, C any](A, *B, []C); func _() { f(1.2, new(string), []byte{}) }`,
+			`f`,
+			[]string{`float64`, `string`, `byte`},
+			`func(float64, *string, []byte)`,
+		},
+		{genericPkg + `p4; func f[A, B any](A, *B, ...[]B); func _() { f(1.2, new(byte)) }`,
+			`f`,
+			[]string{`float64`, `byte`},
+			`func(float64, *byte, ...[]byte)`,
+		},
+
+		{genericPkg + `s1; func f[T any, P interface{~*T}](x T); func _(x string) { f(x) }`,
+			`f`,
+			[]string{`string`, `*string`},
+			`func(x string)`,
+		},
+		{genericPkg + `s2; func f[T any, P interface{~*T}](x []T); func _(x []int) { f(x) }`,
+			`f`,
+			[]string{`int`, `*int`},
+			`func(x []int)`,
+		},
+		{genericPkg + `s3; type C[T any] interface{~chan<- T}; func f[T any, P C[T]](x []T); func _(x []int) { f(x) }`,
+			`f`,
+			[]string{`int`, `chan<- int`},
+			`func(x []int)`,
+		},
+		{genericPkg + `s4; type C[T any] interface{~chan<- T}; func f[T any, P C[T], Q C[[]*P]](x []T); func _(x []int) { f(x) }`,
+			`f`,
+			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
+			`func(x []int)`,
+		},
+
+		{genericPkg + `t1; func f[T any, P interface{~*T}]() T; func _() { _ = f[string] }`,
+			`f`,
+			[]string{`string`, `*string`},
+			`func() string`,
+		},
+		{genericPkg + `t2; type C[T any] interface{~chan<- T}; func f[T any, P C[T]]() []T; func _() { _ = f[int] }`,
+			`f`,
+			[]string{`int`, `chan<- int`},
+			`func() []int`,
+		},
+		{genericPkg + `t3; type C[T any] interface{~chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T; func _() { _ = f[int] }`,
+			`f`,
+			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
+			`func() []int`,
+		},
+	}
+
+	for _, test := range tests {
+		info := Info{}
+		info.Inferred = make(map[ast.Expr]Inferred)
+		name, err := mayTypecheck(t, "InferredInfo", test.src, &info)
+		if err != nil {
+			t.Errorf("package %s: %v", name, err)
+			continue
+		}
+
+		// look for inferred type arguments and signature
+		var targs []Type
+		var sig *Signature
+		for call, inf := range info.Inferred {
+			var fun ast.Expr
+			switch x := call.(type) {
+			case *ast.CallExpr:
+				fun = x.Fun
+			case *ast.IndexExpr:
+				fun = x.X
+			default:
+				panic(fmt.Sprintf("unexpected call expression type %T", call))
+			}
+			if ExprString(fun) == test.fun {
+				targs = inf.TArgs
+				sig = inf.Sig
+				break
+			}
+		}
+		if targs == nil {
+			t.Errorf("package %s: no inferred information found for %s", name, test.fun)
+			continue
+		}
+
+		// check that type arguments are correct
+		if len(targs) != len(test.targs) {
+			t.Errorf("package %s: got %d type arguments; want %d", name, len(targs), len(test.targs))
+			continue
+		}
+		for i, targ := range targs {
+			if got := targ.String(); got != test.targs[i] {
+				t.Errorf("package %s, %d. type argument: got %s; want %s", name, i, got, test.targs[i])
+				continue
+			}
+		}
+
+		// check that signature is correct
+		if got := sig.String(); got != test.sig {
+			t.Errorf("package %s: got %s; want %s", name, got, test.sig)
+		}
+	}
+}
+
 func TestDefsInfo(t *testing.T) {
 	var tests = []struct {
 		src  string
@@ -412,9 +543,6 @@ func TestDefsInfo(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		if strings.HasPrefix(test.src, genericPkg) && !typeparams.Enabled {
-			continue
-		}
 		info := Info{
 			Defs: make(map[*ast.Ident]Object),
 		}
@@ -460,9 +588,6 @@ func TestUsesInfo(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		if strings.HasPrefix(test.src, genericPkg) && !typeparams.Enabled {
-			continue
-		}
 		info := Info{
 			Uses: make(map[*ast.Ident]Object),
 		}
@@ -1704,3 +1829,28 @@ func f(x T) T { return foo.F(x) }
 		}
 	}
 }
+
+func TestInstantiate(t *testing.T) {
+	// eventually we like more tests but this is a start
+	const src = genericPkg + "p; type T[P any] *T[P]"
+	pkg, err := pkgFor(".", src, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// type T should have one type parameter
+	T := pkg.Scope().Lookup("T").Type().(*Named)
+	if n := T.TParams().Len(); n != 1 {
+		t.Fatalf("expected 1 type parameter; found %d", n)
+	}
+
+	// instantiation should succeed (no endless recursion)
+	// even with a nil *Checker
+	var check *Checker
+	res := check.Instantiate(token.NoPos, T, []Type{Typ[Int]}, nil, false)
+
+	// instantiated type should point to itself
+	if res.Underlying().(*Pointer).Elem() != res {
+		t.Fatalf("unexpected result type: %s", res)
+	}
+}
diff --git a/src/go/types/api_typeparams.go b/src/go/types/api_typeparams.go
deleted file mode 100644
index ed744c4dba6..00000000000
--- a/src/go/types/api_typeparams.go
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build typeparams
-// +build typeparams
-
-package types
-
-import (
-	"go/ast"
-)
-
-type (
-	Inferred  = _Inferred
-	Sum       = _Sum
-	TypeParam = _TypeParam
-)
-
-func NewSum(types []Type) Type { return _NewSum(types) }
-
-func (s *Signature) TParams() []*TypeName           { return s._TParams() }
-func (s *Signature) SetTParams(tparams []*TypeName) { s._SetTParams(tparams) }
-
-func (t *Interface) HasTypeList() bool  { return t._HasTypeList() }
-func (t *Interface) IsComparable() bool { return t._IsComparable() }
-func (t *Interface) IsConstraint() bool { return t._IsConstraint() }
-
-func (t *Named) TParams() []*TypeName { return t._TParams() }
-func (t *Named) TArgs() []Type        { return t._TArgs() }
-func (t *Named) SetTArgs(args []Type) { t._SetTArgs(args) }
-
-// Info is documented in api_notypeparams.go.
-type Info struct {
-	Types map[ast.Expr]TypeAndValue
-
-	// Inferred maps calls of parameterized functions that use type inference to
-	// the Inferred type arguments and signature of the function called. The
-	// recorded "call" expression may be an *ast.CallExpr (as in f(x)), or an
-	// *ast.IndexExpr (s in f[T]).
-	Inferred map[ast.Expr]_Inferred
-
-	Defs       map[*ast.Ident]Object
-	Uses       map[*ast.Ident]Object
-	Implicits  map[ast.Node]Object
-	Selections map[*ast.SelectorExpr]*Selection
-	Scopes     map[ast.Node]*Scope
-	InitOrder  []*Initializer
-}
-
-func getInferred(info *Info) map[ast.Expr]_Inferred {
-	return info.Inferred
-}
diff --git a/src/go/types/api_typeparams_test.go b/src/go/types/api_typeparams_test.go
deleted file mode 100644
index 15c9bf09f9d..00000000000
--- a/src/go/types/api_typeparams_test.go
+++ /dev/null
@@ -1,139 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build typeparams
-// +build typeparams
-
-package types_test
-
-import (
-	"fmt"
-	"go/ast"
-	"testing"
-
-	. "go/types"
-)
-
-func TestInferredInfo(t *testing.T) {
-	var tests = []struct {
-		src   string
-		fun   string
-		targs []string
-		sig   string
-	}{
-		{genericPkg + `p0; func f[T any](T); func _() { f(42) }`,
-			`f`,
-			[]string{`int`},
-			`func(int)`,
-		},
-		{genericPkg + `p1; func f[T any](T) T; func _() { f('@') }`,
-			`f`,
-			[]string{`rune`},
-			`func(rune) rune`,
-		},
-		{genericPkg + `p2; func f[T any](...T) T; func _() { f(0i) }`,
-			`f`,
-			[]string{`complex128`},
-			`func(...complex128) complex128`,
-		},
-		{genericPkg + `p3; func f[A, B, C any](A, *B, []C); func _() { f(1.2, new(string), []byte{}) }`,
-			`f`,
-			[]string{`float64`, `string`, `byte`},
-			`func(float64, *string, []byte)`,
-		},
-		{genericPkg + `p4; func f[A, B any](A, *B, ...[]B); func _() { f(1.2, new(byte)) }`,
-			`f`,
-			[]string{`float64`, `byte`},
-			`func(float64, *byte, ...[]byte)`,
-		},
-
-		{genericPkg + `s1; func f[T any, P interface{type *T}](x T); func _(x string) { f(x) }`,
-			`f`,
-			[]string{`string`, `*string`},
-			`func(x string)`,
-		},
-		{genericPkg + `s2; func f[T any, P interface{type *T}](x []T); func _(x []int) { f(x) }`,
-			`f`,
-			[]string{`int`, `*int`},
-			`func(x []int)`,
-		},
-		{genericPkg + `s3; type C[T any] interface{type chan<- T}; func f[T any, P C[T]](x []T); func _(x []int) { f(x) }`,
-			`f`,
-			[]string{`int`, `chan<- int`},
-			`func(x []int)`,
-		},
-		{genericPkg + `s4; type C[T any] interface{type chan<- T}; func f[T any, P C[T], Q C[[]*P]](x []T); func _(x []int) { f(x) }`,
-			`f`,
-			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
-			`func(x []int)`,
-		},
-
-		{genericPkg + `t1; func f[T any, P interface{type *T}]() T; func _() { _ = f[string] }`,
-			`f`,
-			[]string{`string`, `*string`},
-			`func() string`,
-		},
-		{genericPkg + `t2; type C[T any] interface{type chan<- T}; func f[T any, P C[T]]() []T; func _() { _ = f[int] }`,
-			`f`,
-			[]string{`int`, `chan<- int`},
-			`func() []int`,
-		},
-		{genericPkg + `t3; type C[T any] interface{type chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T; func _() { _ = f[int] }`,
-			`f`,
-			[]string{`int`, `chan<- int`, `chan<- []*chan<- int`},
-			`func() []int`,
-		},
-	}
-
-	for _, test := range tests {
-		info := Info{}
-		info.Inferred = make(map[ast.Expr]Inferred)
-		name, err := mayTypecheck(t, "InferredInfo", test.src, &info)
-		if err != nil {
-			t.Errorf("package %s: %v", name, err)
-			continue
-		}
-
-		// look for inferred type arguments and signature
-		var targs []Type
-		var sig *Signature
-		for call, inf := range info.Inferred {
-			var fun ast.Expr
-			switch x := call.(type) {
-			case *ast.CallExpr:
-				fun = x.Fun
-			case *ast.IndexExpr:
-				fun = x.X
-			default:
-				panic(fmt.Sprintf("unexpected call expression type %T", call))
-			}
-			if ExprString(fun) == test.fun {
-				targs = inf.Targs
-				sig = inf.Sig
-				break
-			}
-		}
-		if targs == nil {
-			t.Errorf("package %s: no inferred information found for %s", name, test.fun)
-			continue
-		}
-
-		// check that type arguments are correct
-		if len(targs) != len(test.targs) {
-			t.Errorf("package %s: got %d type arguments; want %d", name, len(targs), len(test.targs))
-			continue
-		}
-		for i, targ := range targs {
-			if got := targ.String(); got != test.targs[i] {
-				t.Errorf("package %s, %d. type argument: got %s; want %s", name, i, got, test.targs[i])
-				continue
-			}
-		}
-
-		// check that signature is correct
-		if got := sig.String(); got != test.sig {
-			t.Errorf("package %s: got %s; want %s", name, got, test.sig)
-		}
-	}
-}
diff --git a/src/go/types/array.go b/src/go/types/array.go
new file mode 100644
index 00000000000..5b28474bb33
--- /dev/null
+++ b/src/go/types/array.go
@@ -0,0 +1,25 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// An Array represents an array type.
+type Array struct {
+	len  int64
+	elem Type
+}
+
+// NewArray returns a new array type for the given element type and length.
+// A negative length indicates an unknown length.
+func NewArray(elem Type, len int64) *Array { return &Array{len: len, elem: elem} }
+
+// Len returns the length of array a.
+// A negative result indicates an unknown length.
+func (a *Array) Len() int64 { return a.len }
+
+// Elem returns element type of array a.
+func (a *Array) Elem() Type { return a.elem }
+
+func (t *Array) Underlying() Type { return t }
+func (t *Array) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/assignments.go b/src/go/types/assignments.go
index 18eae621840..595f426e109 100644
--- a/src/go/types/assignments.go
+++ b/src/go/types/assignments.go
@@ -71,7 +71,7 @@ func (check *Checker) assignment(x *operand, T Type, context string) {
 	}
 
 	// A generic (non-instantiated) function value cannot be assigned to a variable.
-	if sig := asSignature(x.typ); sig != nil && len(sig.tparams) > 0 {
+	if sig := asSignature(x.typ); sig != nil && sig.TParams().Len() > 0 {
 		check.errorf(x, _Todo, "cannot use generic function %s without instantiation in %s", x, context)
 	}
 
diff --git a/src/go/types/basic.go b/src/go/types/basic.go
new file mode 100644
index 00000000000..215923f6573
--- /dev/null
+++ b/src/go/types/basic.go
@@ -0,0 +1,82 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// BasicKind describes the kind of basic type.
+type BasicKind int
+
+const (
+	Invalid BasicKind = iota // type is invalid
+
+	// predeclared types
+	Bool
+	Int
+	Int8
+	Int16
+	Int32
+	Int64
+	Uint
+	Uint8
+	Uint16
+	Uint32
+	Uint64
+	Uintptr
+	Float32
+	Float64
+	Complex64
+	Complex128
+	String
+	UnsafePointer
+
+	// types for untyped values
+	UntypedBool
+	UntypedInt
+	UntypedRune
+	UntypedFloat
+	UntypedComplex
+	UntypedString
+	UntypedNil
+
+	// aliases
+	Byte = Uint8
+	Rune = Int32
+)
+
+// BasicInfo is a set of flags describing properties of a basic type.
+type BasicInfo int
+
+// Properties of basic types.
+const (
+	IsBoolean BasicInfo = 1 << iota
+	IsInteger
+	IsUnsigned
+	IsFloat
+	IsComplex
+	IsString
+	IsUntyped
+
+	IsOrdered   = IsInteger | IsFloat | IsString
+	IsNumeric   = IsInteger | IsFloat | IsComplex
+	IsConstType = IsBoolean | IsNumeric | IsString
+)
+
+// A Basic represents a basic type.
+type Basic struct {
+	kind BasicKind
+	info BasicInfo
+	name string
+}
+
+// Kind returns the kind of basic type b.
+func (b *Basic) Kind() BasicKind { return b.kind }
+
+// Info returns information about properties of basic type b.
+func (b *Basic) Info() BasicInfo { return b.info }
+
+// Name returns the name of basic type b.
+func (b *Basic) Name() string { return b.name }
+
+func (t *Basic) Underlying() Type { return t }
+func (t *Basic) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/builtins.go b/src/go/types/builtins.go
index 739051cc611..c73d94658ab 100644
--- a/src/go/types/builtins.go
+++ b/src/go/types/builtins.go
@@ -179,9 +179,9 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 				mode = value
 			}
 
-		case *_Sum:
-			if t.is(func(t Type) bool {
-				switch t := under(t).(type) {
+		case *Union:
+			if t.underIs(func(t Type) bool {
+				switch t := t.(type) {
 				case *Basic:
 					if isString(t) && id == _Len {
 						return true
@@ -217,19 +217,23 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 
 	case _Close:
 		// close(c)
-		c := asChan(x.typ)
-		if c == nil {
-			check.invalidArg(x, _InvalidClose, "%s is not a channel", x)
+		if !underIs(x.typ, func(u Type) bool {
+			uch, _ := u.(*Chan)
+			if uch == nil {
+				check.invalidOp(x, _InvalidClose, "cannot close non-channel %s", x)
+				return false
+			}
+			if uch.dir == RecvOnly {
+				check.invalidOp(x, _InvalidClose, "cannot close receive-only channel %s", x)
+				return false
+			}
+			return true
+		}) {
 			return
 		}
-		if c.dir == RecvOnly {
-			check.invalidArg(x, _InvalidClose, "%s must not be a receive-only channel", x)
-			return
-		}
-
 		x.mode = novalue
 		if check.Types != nil {
-			check.recordBuiltinType(call.Fun, makeSig(nil, c))
+			check.recordBuiltinType(call.Fun, makeSig(nil, x.typ))
 		}
 
 	case _Complex:
@@ -286,7 +290,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 		}
 
 		// both argument types must be identical
-		if !check.identical(x.typ, y.typ) {
+		if !Identical(x.typ, y.typ) {
 			check.invalidArg(x, _InvalidComplex, "mismatched types %s and %s", x.typ, y.typ)
 			return
 		}
@@ -337,13 +341,15 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 			return
 		}
 		var src Type
-		switch t := optype(y.typ).(type) {
+		switch t := under(y.typ).(type) {
 		case *Basic:
 			if isString(y.typ) {
 				src = universeByte
 			}
 		case *Slice:
 			src = t.elem
+		case *TypeParam:
+			check.error(x, _Todo, "copy on generic operands not yet implemented")
 		}
 
 		if dst == nil || src == nil {
@@ -351,7 +357,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 			return
 		}
 
-		if !check.identical(dst, src) {
+		if !Identical(dst, src) {
 			check.invalidArg(x, _InvalidCopy, "arguments to copy %s and %s have different element types %s and %s", x, &y, dst, src)
 			return
 		}
@@ -363,25 +369,40 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 		x.typ = Typ[Int]
 
 	case _Delete:
-		// delete(m, k)
-		m := asMap(x.typ)
-		if m == nil {
-			check.invalidArg(x, _InvalidDelete, "%s is not a map", x)
+		// delete(map_, key)
+		// map_ must be a map type or a type parameter describing map types.
+		// The key cannot be a type parameter for now.
+		map_ := x.typ
+		var key Type
+		if !underIs(map_, func(u Type) bool {
+			map_, _ := u.(*Map)
+			if map_ == nil {
+				check.invalidArg(x, _InvalidDelete, "%s is not a map", x)
+				return false
+			}
+			if key != nil && !Identical(map_.key, key) {
+				check.invalidArg(x, _Todo, "maps of %s must have identical key types", x)
+				return false
+			}
+			key = map_.key
+			return true
+		}) {
 			return
 		}
+
 		arg(x, 1) // k
 		if x.mode == invalid {
 			return
 		}
 
-		check.assignment(x, m.key, "argument to delete")
+		check.assignment(x, key, "argument to delete")
 		if x.mode == invalid {
 			return
 		}
 
 		x.mode = novalue
 		if check.Types != nil {
-			check.recordBuiltinType(call.Fun, makeSig(nil, m, m.key))
+			check.recordBuiltinType(call.Fun, makeSig(nil, map_, key))
 		}
 
 	case _Imag, _Real:
@@ -464,13 +485,13 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 		var valid func(t Type) bool
 		valid = func(t Type) bool {
 			var m int
-			switch t := optype(t).(type) {
+			switch t := under(t).(type) {
 			case *Slice:
 				m = 2
 			case *Map, *Chan:
 				m = 1
-			case *_Sum:
-				return t.is(valid)
+			case *TypeParam:
+				return t.underIs(valid)
 			default:
 				return false
 			}
@@ -588,6 +609,11 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 
 	case _Add:
 		// unsafe.Add(ptr unsafe.Pointer, len IntegerType) unsafe.Pointer
+		if !check.allowVersion(check.pkg, 1, 17) {
+			check.errorf(call.Fun, _InvalidUnsafeAdd, "unsafe.Add requires go1.17 or later")
+			return
+		}
+
 		check.assignment(x, Typ[UnsafePointer], "argument to unsafe.Add")
 		if x.mode == invalid {
 			return
@@ -607,19 +633,22 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 
 	case _Alignof:
 		// unsafe.Alignof(x T) uintptr
-		if asTypeParam(x.typ) != nil {
-			check.invalidOp(call, _Todo, "unsafe.Alignof undefined for %s", x)
-			return
-		}
 		check.assignment(x, nil, "argument to unsafe.Alignof")
 		if x.mode == invalid {
 			return
 		}
 
-		x.mode = constant_
-		x.val = constant.MakeInt64(check.conf.alignof(x.typ))
+		if hasVarSize(x.typ) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], x.typ))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.alignof(x.typ))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Offsetof:
 		// unsafe.Offsetof(x T) uintptr, where x must be a selector
@@ -639,7 +668,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 
 		base := derefStructPtr(x.typ)
 		sel := selx.Sel.Name
-		obj, index, indirect := check.lookupFieldOrMethod(base, false, check.pkg, sel)
+		obj, index, indirect := LookupFieldOrMethod(base, false, check.pkg, sel)
 		switch obj.(type) {
 		case nil:
 			check.invalidArg(x, _MissingFieldOrMethod, "%s has no single field %s", base, sel)
@@ -657,33 +686,51 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 			return
 		}
 
-		// TODO(gri) Should we pass x.typ instead of base (and indirect report if derefStructPtr indirected)?
+		// TODO(gri) Should we pass x.typ instead of base (and have indirect report if derefStructPtr indirected)?
 		check.recordSelection(selx, FieldVal, base, obj, index, false)
 
-		offs := check.conf.offsetof(base, index)
-		x.mode = constant_
-		x.val = constant.MakeInt64(offs)
+		// The field offset is considered a variable even if the field is declared before
+		// the part of the struct which is variable-sized. This makes both the rules
+		// simpler and also permits (or at least doesn't prevent) a compiler from re-
+		// arranging struct fields if it wanted to.
+		if hasVarSize(base) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], obj.Type()))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.offsetof(base, index))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Sizeof:
 		// unsafe.Sizeof(x T) uintptr
-		if asTypeParam(x.typ) != nil {
-			check.invalidOp(call, _Todo, "unsafe.Sizeof undefined for %s", x)
-			return
-		}
 		check.assignment(x, nil, "argument to unsafe.Sizeof")
 		if x.mode == invalid {
 			return
 		}
 
-		x.mode = constant_
-		x.val = constant.MakeInt64(check.conf.sizeof(x.typ))
+		if hasVarSize(x.typ) {
+			x.mode = value
+			if check.Types != nil {
+				check.recordBuiltinType(call.Fun, makeSig(Typ[Uintptr], x.typ))
+			}
+		} else {
+			x.mode = constant_
+			x.val = constant.MakeInt64(check.conf.sizeof(x.typ))
+			// result is constant - no need to record signature
+		}
 		x.typ = Typ[Uintptr]
-		// result is constant - no need to record signature
 
 	case _Slice:
 		// unsafe.Slice(ptr *T, len IntegerType) []T
+		if !check.allowVersion(check.pkg, 1, 17) {
+			check.errorf(call.Fun, _InvalidUnsafeSlice, "unsafe.Slice requires go1.17 or later")
+			return
+		}
+
 		typ := asPointer(x.typ)
 		if typ == nil {
 			check.invalidArg(x, _InvalidUnsafeSlice, "%s is not a pointer", x)
@@ -747,6 +794,25 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	return true
 }
 
+// hasVarSize reports if the size of type t is variable due to type parameters.
+func hasVarSize(t Type) bool {
+	switch t := under(t).(type) {
+	case *Array:
+		return hasVarSize(t.elem)
+	case *Struct:
+		for _, f := range t.fields {
+			if hasVarSize(f.typ) {
+				return true
+			}
+		}
+	case *TypeParam:
+		return true
+	case *Named, *Union, *top:
+		unreachable()
+	}
+	return false
+}
+
 // applyTypeFunc applies f to x. If x is a type parameter,
 // the result is a type parameter constrained by an new
 // interface bound. The type bounds for that interface
@@ -759,9 +825,11 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
 		// Test if t satisfies the requirements for the argument
 		// type and collect possible result types at the same time.
 		var rtypes []Type
-		if !tp.Bound().is(func(x Type) bool {
-			if r := f(x); r != nil {
+		var tildes []bool
+		if !tp.iface().is(func(typ Type, tilde bool) bool {
+			if r := f(typ); r != nil {
 				rtypes = append(rtypes, r)
+				tildes = append(tildes, tilde)
 				return true
 			}
 			return false
@@ -769,11 +837,14 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
 			return nil
 		}
 
-		// construct a suitable new type parameter
-		tpar := NewTypeName(token.NoPos, nil /* = Universe pkg */, "", nil)
-		ptyp := check.newTypeParam(tpar, 0, &emptyInterface) // assigns type to tpar as a side-effect
-		tsum := _NewSum(rtypes)
-		ptyp.bound = &Interface{types: tsum, allMethods: markComplete, allTypes: tsum}
+		// Construct a suitable new type parameter for the sum type. The
+		// type param is placed in the current package so export/import
+		// works as expected.
+		tpar := NewTypeName(token.NoPos, check.pkg, "", nil)
+		ptyp := check.NewTypeParam(tpar, &emptyInterface) // assigns type to tpar as a side-effect
+		ptyp.index = tp.index
+		tsum := newUnion(rtypes, tildes)
+		ptyp.bound = &Interface{complete: true, tset: &_TypeSet{types: tsum}}
 
 		return ptyp
 	}
diff --git a/src/go/types/builtins_test.go b/src/go/types/builtins_test.go
index 11de9a1ac1a..cee3d315e59 100644
--- a/src/go/types/builtins_test.go
+++ b/src/go/types/builtins_test.go
@@ -113,12 +113,15 @@ var builtinCalls = []struct {
 
 	{"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`},                 // constant
 	{"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
+	{"Alignof", `var x P; _ = unsafe.Alignof(x)`, `func(p.P₁) uintptr`},
 
 	{"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`},           // constant
 	{"Offsetof", `var x struct{_ int; f bool}; _ = unsafe.Offsetof((&x).f)`, `invalid type`}, // constant
+	{"Offsetof", `var x struct{_ int; f P}; _ = unsafe.Offsetof((&x).f)`, `func(p.P₁) uintptr`},
 
 	{"Sizeof", `_ = unsafe.Sizeof(0)`, `invalid type`},                 // constant
 	{"Sizeof", `var x struct{}; _ = unsafe.Sizeof(x)`, `invalid type`}, // constant
+	{"Sizeof", `var x P; _ = unsafe.Sizeof(x)`, `func(p.P₁) uintptr`},
 
 	{"Slice", `var p *int; _ = unsafe.Slice(p, 1)`, `func(*int, int) []int`},
 	{"Slice", `var p *byte; var n uintptr; _ = unsafe.Slice(p, n)`, `func(*byte, uintptr) []byte`},
@@ -151,8 +154,10 @@ func TestBuiltinSignatures(t *testing.T) {
 	}
 }
 
+// parseGenericSrc in types2 is not necessary. We can just parse in testBuiltinSignature below.
+
 func testBuiltinSignature(t *testing.T, name, src0, want string) {
-	src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _() { %s }`, src0)
+	src := fmt.Sprintf(`package p; import "unsafe"; type _ unsafe.Pointer /* use unsafe */; func _[P any]() { %s }`, src0)
 	f, err := parser.ParseFile(fset, "", src, 0)
 	if err != nil {
 		t.Errorf("%s: %s", src0, err)
diff --git a/src/go/types/call.go b/src/go/types/call.go
index 631ea426c6b..da2f319a4a7 100644
--- a/src/go/types/call.go
+++ b/src/go/types/call.go
@@ -16,23 +16,22 @@ import (
 
 // funcInst type-checks a function instantiation inst and returns the result in x.
 // The operand x must be the evaluation of inst.X and its type must be a signature.
-func (check *Checker) funcInst(x *operand, inst *ast.IndexExpr) {
-	xlist := typeparams.UnpackExpr(inst.Index)
-	targs := check.typeList(xlist)
+func (check *Checker) funcInst(x *operand, ix *typeparams.IndexExpr) {
+	targs := check.typeList(ix.Indices)
 	if targs == nil {
 		x.mode = invalid
-		x.expr = inst
+		x.expr = ix.Orig
 		return
 	}
-	assert(len(targs) == len(xlist))
+	assert(len(targs) == len(ix.Indices))
 
 	// check number of type arguments (got) vs number of type parameters (want)
 	sig := x.typ.(*Signature)
-	got, want := len(targs), len(sig.tparams)
+	got, want := len(targs), sig.TParams().Len()
 	if got > want {
-		check.errorf(xlist[got-1], _Todo, "got %d type arguments but want %d", got, want)
+		check.errorf(ix.Indices[got-1], _Todo, "got %d type arguments but want %d", got, want)
 		x.mode = invalid
-		x.expr = inst
+		x.expr = ix.Orig
 		return
 	}
 
@@ -40,11 +39,11 @@ func (check *Checker) funcInst(x *operand, inst *ast.IndexExpr) {
 	inferred := false
 
 	if got < want {
-		targs = check.infer(inst, sig.tparams, targs, nil, nil, true)
+		targs = check.infer(ix.Orig, sig.TParams().list(), targs, nil, nil, true)
 		if targs == nil {
 			// error was already reported
 			x.mode = invalid
-			x.expr = inst
+			x.expr = ix.Orig
 			return
 		}
 		got = len(targs)
@@ -55,34 +54,36 @@ func (check *Checker) funcInst(x *operand, inst *ast.IndexExpr) {
 	// determine argument positions (for error reporting)
 	// TODO(rFindley) use a positioner here? instantiate would need to be
 	//                updated accordingly.
-	poslist := make([]token.Pos, len(xlist))
-	for i, x := range xlist {
+	poslist := make([]token.Pos, len(ix.Indices))
+	for i, x := range ix.Indices {
 		poslist[i] = x.Pos()
 	}
 
 	// instantiate function signature
-	res := check.instantiate(x.Pos(), sig, targs, poslist).(*Signature)
-	assert(res.tparams == nil) // signature is not generic anymore
+	res := check.Instantiate(x.Pos(), sig, targs, poslist, true).(*Signature)
+	assert(res.TParams().Len() == 0) // signature is not generic anymore
 	if inferred {
-		check.recordInferred(inst, targs, res)
+		check.recordInferred(ix.Orig, targs, res)
 	}
 	x.typ = res
 	x.mode = value
-	x.expr = inst
+	x.expr = ix.Orig
 }
 
 func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
-	var inst *ast.IndexExpr
-	if iexpr, _ := call.Fun.(*ast.IndexExpr); iexpr != nil {
-		if check.indexExpr(x, iexpr) {
+	ix := typeparams.UnpackIndexExpr(call.Fun)
+	if ix != nil {
+		if check.indexExpr(x, ix) {
 			// Delay function instantiation to argument checking,
 			// where we combine type and value arguments for type
 			// inference.
 			assert(x.mode == value)
-			inst = iexpr
+		} else {
+			ix = nil
 		}
-		x.expr = iexpr
+		x.expr = call.Fun
 		check.record(x)
+
 	} else {
 		check.exprOrType(x, call.Fun)
 	}
@@ -108,8 +109,7 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
 					break
 				}
 				if t := asInterface(T); t != nil {
-					check.completeInterface(token.NoPos, t)
-					if t._IsConstraint() {
+					if t.IsConstraint() {
 						check.errorf(call, _Todo, "cannot use interface %s in conversion (contains type list or is comparable)", T)
 						break
 					}
@@ -149,21 +149,20 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
 
 	// evaluate type arguments, if any
 	var targs []Type
-	if inst != nil {
-		xlist := typeparams.UnpackExpr(inst.Index)
-		targs = check.typeList(xlist)
+	if ix != nil {
+		targs = check.typeList(ix.Indices)
 		if targs == nil {
 			check.use(call.Args...)
 			x.mode = invalid
 			x.expr = call
 			return statement
 		}
-		assert(len(targs) == len(xlist))
+		assert(len(targs) == len(ix.Indices))
 
 		// check number of type arguments (got) vs number of type parameters (want)
-		got, want := len(targs), len(sig.tparams)
+		got, want := len(targs), sig.TParams().Len()
 		if got > want {
-			check.errorf(xlist[want], _Todo, "got %d type arguments but want %d", got, want)
+			check.errorf(ix.Indices[want], _Todo, "got %d type arguments but want %d", got, want)
 			check.use(call.Args...)
 			x.mode = invalid
 			x.expr = call
@@ -195,7 +194,7 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
 
 	// if type inference failed, a parametrized result must be invalidated
 	// (operands cannot have a parametrized type)
-	if x.mode == value && len(sig.tparams) > 0 && isParameterized(sig.tparams, x.typ) {
+	if x.mode == value && sig.TParams().Len() > 0 && isParameterized(sig.TParams().list(), x.typ) {
 		x.mode = invalid
 	}
 
@@ -325,24 +324,24 @@ func (check *Checker) arguments(call *ast.CallExpr, sig *Signature, targs []Type
 	}
 
 	// infer type arguments and instantiate signature if necessary
-	if len(sig.tparams) > 0 {
+	if sig.TParams().Len() > 0 {
 		// TODO(gri) provide position information for targs so we can feed
 		//           it to the instantiate call for better error reporting
-		targs := check.infer(call, sig.tparams, targs, sigParams, args, true)
+		targs := check.infer(call, sig.TParams().list(), targs, sigParams, args, true)
 		if targs == nil {
 			return // error already reported
 		}
 
 		// compute result signature
-		rsig = check.instantiate(call.Pos(), sig, targs, nil).(*Signature)
-		assert(rsig.tparams == nil) // signature is not generic anymore
+		rsig = check.Instantiate(call.Pos(), sig, targs, nil, true).(*Signature)
+		assert(rsig.TParams().Len() == 0) // signature is not generic anymore
 		check.recordInferred(call, targs, rsig)
 
 		// Optimization: Only if the parameter list was adjusted do we
 		// need to compute it from the adjusted list; otherwise we can
 		// simply use the result signature's parameter list.
 		if adjusted {
-			sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(sig.tparams, targs)).(*Tuple)
+			sigParams = check.subst(call.Pos(), sigParams, makeSubstMap(sig.TParams().list(), targs)).(*Tuple)
 		} else {
 			sigParams = rsig.params
 		}
@@ -471,7 +470,7 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 
 	check.instantiatedOperand(x)
 
-	obj, index, indirect = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel)
+	obj, index, indirect = LookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel)
 	if obj == nil {
 		switch {
 		case index != nil:
@@ -483,11 +482,10 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 			var why string
 			if tpar := asTypeParam(x.typ); tpar != nil {
 				// Type parameter bounds don't specify fields, so don't mention "field".
-				switch obj := tpar.Bound().obj.(type) {
-				case nil:
+				if tname := tpar.iface().obj; tname != nil {
+					why = check.sprintf("interface %s has no method %s", tname.name, sel)
+				} else {
 					why = check.sprintf("type bound for %s has no method %s", x.typ, sel)
-				case *TypeName:
-					why = check.sprintf("interface %s has no method %s", obj.name, sel)
 				}
 			} else {
 				why = check.sprintf("type %s has no field or method %s", x.typ, sel)
@@ -501,7 +499,7 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 				} else {
 					changeCase = string(unicode.ToUpper(r)) + sel[1:]
 				}
-				if obj, _, _ = check.lookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, changeCase); obj != nil {
+				if obj, _, _ = LookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, changeCase); obj != nil {
 					why += ", but does have " + changeCase
 				}
 			}
@@ -519,7 +517,7 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 		// the signature accordingly.
 		// TODO(gri) factor this code out
 		sig := m.typ.(*Signature)
-		if len(sig.rparams) > 0 {
+		if sig.RParams().Len() > 0 {
 			// For inference to work, we must use the receiver type
 			// matching the receiver in the actual method declaration.
 			// If the method is embedded, the matching receiver is the
@@ -547,7 +545,7 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 			// the receiver type arguments here, the receiver must be be otherwise invalid
 			// and an error has been reported elsewhere.
 			arg := operand{mode: variable, expr: x.expr, typ: recv}
-			targs := check.infer(m, sig.rparams, nil, NewTuple(sig.recv), []*operand{&arg}, false /* no error reporting */)
+			targs := check.infer(m, sig.RParams().list(), nil, NewTuple(sig.recv), []*operand{&arg}, false /* no error reporting */)
 			if targs == nil {
 				// We may reach here if there were other errors (see issue #40056).
 				goto Error
@@ -556,7 +554,7 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 			// (If we modify m, some tests will fail; possibly because the m is in use.)
 			// TODO(gri) investigate and provide a correct explanation here
 			copy := *m
-			copy.typ = check.subst(e.Pos(), m.typ, makeSubstMap(sig.rparams, targs))
+			copy.typ = check.subst(e.Pos(), m.typ, makeSubstMap(sig.RParams().list(), targs))
 			obj = ©
 		}
 		// TODO(gri) we also need to do substitution for parameterized interface methods
@@ -575,17 +573,37 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 
 		check.recordSelection(e, MethodExpr, x.typ, m, index, indirect)
 
+		sig := m.typ.(*Signature)
+		if sig.recv == nil {
+			check.error(e, _InvalidDeclCycle, "illegal cycle in method declaration")
+			goto Error
+		}
+
 		// the receiver type becomes the type of the first function
 		// argument of the method expression's function type
 		var params []*Var
-		sig := m.typ.(*Signature)
 		if sig.params != nil {
 			params = sig.params.vars
 		}
+		// Be consistent about named/unnamed parameters. This is not needed
+		// for type-checking, but the newly constructed signature may appear
+		// in an error message and then have mixed named/unnamed parameters.
+		// (An alternative would be to not print parameter names in errors,
+		// but it's useful to see them; this is cheap and method expressions
+		// are rare.)
+		name := ""
+		if len(params) > 0 && params[0].name != "" {
+			// name needed
+			name = sig.recv.name
+			if name == "" {
+				name = "_"
+			}
+		}
+		params = append([]*Var{NewVar(sig.recv.pos, sig.recv.pkg, name, x.typ)}, params...)
 		x.mode = value
 		x.typ = &Signature{
 			tparams:  sig.tparams,
-			params:   NewTuple(append([]*Var{NewVar(token.NoPos, check.pkg, "_", x.typ)}, params...)...),
+			params:   NewTuple(params...),
 			results:  sig.results,
 			variadic: sig.variadic,
 		}
diff --git a/src/go/types/chan.go b/src/go/types/chan.go
new file mode 100644
index 00000000000..1f7b72be309
--- /dev/null
+++ b/src/go/types/chan.go
@@ -0,0 +1,35 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// A Chan represents a channel type.
+type Chan struct {
+	dir  ChanDir
+	elem Type
+}
+
+// A ChanDir value indicates a channel direction.
+type ChanDir int
+
+// The direction of a channel is indicated by one of these constants.
+const (
+	SendRecv ChanDir = iota
+	SendOnly
+	RecvOnly
+)
+
+// NewChan returns a new channel type for the given direction and element type.
+func NewChan(dir ChanDir, elem Type) *Chan {
+	return &Chan{dir: dir, elem: elem}
+}
+
+// Dir returns the direction of channel c.
+func (c *Chan) Dir() ChanDir { return c.dir }
+
+// Elem returns the element type of channel c.
+func (c *Chan) Elem() Type { return c.elem }
+
+func (t *Chan) Underlying() Type { return t }
+func (t *Chan) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/check.go b/src/go/types/check.go
index 25ea4906be3..b2d076dc680 100644
--- a/src/go/types/check.go
+++ b/src/go/types/check.go
@@ -73,7 +73,7 @@ type importKey struct {
 // A dotImportKey describes a dot-imported object in the given scope.
 type dotImportKey struct {
 	scope *Scope
-	obj   Object
+	name  string
 }
 
 // A Checker maintains the state of the type checker.
@@ -85,11 +85,11 @@ type Checker struct {
 	fset *token.FileSet
 	pkg  *Package
 	*Info
-	version version                    // accepted language version
-	objMap  map[Object]*declInfo       // maps package-level objects and (non-interface) methods to declaration info
-	impMap  map[importKey]*Package     // maps (import path, source directory) to (complete or fake) package
-	posMap  map[*Interface][]token.Pos // maps interface types to lists of embedded interface positions
-	typMap  map[string]*Named          // maps an instantiated named type hash to a *Named type
+	version version                // accepted language version
+	nextID  uint64                 // unique Id for type parameters (first valid Id is 1)
+	objMap  map[Object]*declInfo   // maps package-level objects and (non-interface) methods to declaration info
+	impMap  map[importKey]*Package // maps (import path, source directory) to (complete or fake) package
+	typMap  map[string]*Named      // maps an instantiated named type hash to a *Named type
 
 	// pkgPathMap maps package names to the set of distinct import paths we've
 	// seen for that name, anywhere in the import graph. It is used for
@@ -192,7 +192,6 @@ func NewChecker(conf *Config, fset *token.FileSet, pkg *Package, info *Info) *Ch
 		version: version,
 		objMap:  make(map[Object]*declInfo),
 		impMap:  make(map[importKey]*Package),
-		posMap:  make(map[*Interface][]token.Pos),
 		typMap:  make(map[string]*Named),
 	}
 }
@@ -274,10 +273,6 @@ func (check *Checker) checkFiles(files []*ast.File) (err error) {
 
 	check.recordUntyped()
 
-	if check.Info != nil {
-		sanitizeInfo(check.Info)
-	}
-
 	check.pkg.complete = true
 
 	// no longer needed - release memory
@@ -411,8 +406,8 @@ func (check *Checker) recordCommaOkTypes(x ast.Expr, a [2]Type) {
 func (check *Checker) recordInferred(call ast.Expr, targs []Type, sig *Signature) {
 	assert(call != nil)
 	assert(sig != nil)
-	if m := getInferred(check.Info); m != nil {
-		m[call] = _Inferred{targs, sig}
+	if m := check.Info.Inferred; m != nil {
+		m[call] = Inferred{targs, sig}
 	}
 }
 
diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
index c5dc93eade6..8c8452c9c68 100644
--- a/src/go/types/check_test.go
+++ b/src/go/types/check_test.go
@@ -202,17 +202,18 @@ func asGoVersion(s string) string {
 	return ""
 }
 
-func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string, srcs [][]byte, manual bool) {
+func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool, imp Importer) {
 	if len(filenames) == 0 {
 		t.Fatal("no source files")
 	}
 
+	if strings.HasSuffix(filenames[0], ".go1") {
+		// TODO(rfindley): re-enable this test by using GoVersion.
+		t.Skip("type params are enabled")
+	}
+
 	mode := parser.AllErrors
-	if strings.HasSuffix(filenames[0], ".go2") {
-		if !typeparams.Enabled {
-			t.Skip("type params are not enabled")
-		}
-	} else {
+	if !strings.HasSuffix(filenames[0], ".go2") {
 		mode |= typeparams.DisallowParsing
 	}
 
@@ -225,6 +226,7 @@ func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string,
 	}
 
 	// if no Go version is given, consider the package name
+	goVersion := *goVersion
 	if goVersion == "" {
 		goVersion = asGoVersion(pkgName)
 	}
@@ -249,7 +251,10 @@ func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string,
 		}
 	}
 
-	conf.Importer = importer.Default()
+	conf.Importer = imp
+	if imp == nil {
+		conf.Importer = importer.Default()
+	}
 	conf.Error = func(err error) {
 		if *haltOnError {
 			defer panic(err)
@@ -297,29 +302,48 @@ func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string,
 	}
 }
 
-// TestManual is for manual testing of input files, provided as a list
-// of arguments after the test arguments (and a separating "--"). For
-// instance, to check the files foo.go and bar.go, use:
+// TestManual is for manual testing of a package - either provided
+// as a list of filenames belonging to the package, or a directory
+// name containing the package files - after the test arguments
+// (and a separating "--"). For instance, to test the package made
+// of the files foo.go and bar.go, use:
 //
 // 	go test -run Manual -- foo.go bar.go
 //
-// Provide the -verify flag to verify errors against ERROR comments in
-// the input files rather than having a list of errors reported.
-// The accepted Go language version can be controlled with the -lang flag.
+// If no source arguments are provided, the file testdata/manual.go2
+// is used instead.
+// Provide the -verify flag to verify errors against ERROR comments
+// in the input files rather than having a list of errors reported.
+// The accepted Go language version can be controlled with the -lang
+// flag.
 func TestManual(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
 	filenames := flag.Args()
 	if len(filenames) == 0 {
-		return
+		filenames = []string{filepath.FromSlash("testdata/manual.go2")}
 	}
-	testenv.MustHaveGoBuild(t)
+
+	info, err := os.Stat(filenames[0])
+	if err != nil {
+		t.Fatalf("TestManual: %v", err)
+	}
+
 	DefPredeclaredTestFuncs()
-	testPkg(t, filenames, *goVersion, true)
+	if info.IsDir() {
+		if len(filenames) > 1 {
+			t.Fatal("TestManual: must have only one directory argument")
+		}
+		testDir(t, filenames[0], true)
+	} else {
+		testPkg(t, filenames, true)
+	}
 }
 
 func TestLongConstants(t *testing.T) {
 	format := "package longconst\n\nconst _ = %s\nconst _ = %s // ERROR excessively long constant"
 	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
-	checkFiles(t, nil, "", []string{"longconst.go"}, [][]byte{[]byte(src)}, false)
+	testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false, nil)
 }
 
 // TestIndexRepresentability tests that constant index operands must
@@ -327,17 +351,24 @@ func TestLongConstants(t *testing.T) {
 // represent larger values.
 func TestIndexRepresentability(t *testing.T) {
 	const src = "package index\n\nvar s []byte\nvar _ = s[int64 /* ERROR \"int64\\(1\\) << 40 \\(.*\\) overflows int\" */ (1) << 40]"
-	checkFiles(t, &StdSizes{4, 4}, "", []string{"index.go"}, [][]byte{[]byte(src)}, false)
+	testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil)
 }
 
-func TestCheck(t *testing.T)     { DefPredeclaredTestFuncs(); testDir(t, "check") }
-func TestExamples(t *testing.T)  { testDir(t, "examples") }
-func TestFixedbugs(t *testing.T) { testDir(t, "fixedbugs") }
+func TestIssue47243_TypedRHS(t *testing.T) {
+	// The RHS of the shift expression below overflows uint on 32bit platforms,
+	// but this is OK as it is explicitly typed.
+	const src = "package issue47243\n\nvar a uint64; var _ = a << uint64(4294967296)" // uint64(1<<32)
+	testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil)
+}
 
-func testDir(t *testing.T, dir string) {
+func TestCheck(t *testing.T)     { DefPredeclaredTestFuncs(); testDirFiles(t, "testdata/check", false) }
+func TestExamples(t *testing.T)  { testDirFiles(t, "testdata/examples", false) }
+func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) }
+
+func testDirFiles(t *testing.T, dir string, manual bool) {
 	testenv.MustHaveGoBuild(t)
+	dir = filepath.FromSlash(dir)
 
-	dir = filepath.Join("testdata", dir)
 	fis, err := os.ReadDir(dir)
 	if err != nil {
 		t.Error(err)
@@ -347,28 +378,38 @@ func testDir(t *testing.T, dir string) {
 	for _, fi := range fis {
 		path := filepath.Join(dir, fi.Name())
 
-		// if fi is a directory, its files make up a single package
-		var filenames []string
+		// If fi is a directory, its files make up a single package.
 		if fi.IsDir() {
-			fis, err := os.ReadDir(path)
-			if err != nil {
-				t.Error(err)
-				continue
-			}
-			for _, fi := range fis {
-				filenames = append(filenames, filepath.Join(path, fi.Name()))
-			}
+			testDir(t, path, manual)
 		} else {
-			filenames = []string{path}
+			t.Run(filepath.Base(path), func(t *testing.T) {
+				testPkg(t, []string{path}, manual)
+			})
 		}
-		t.Run(filepath.Base(path), func(t *testing.T) {
-			testPkg(t, filenames, "", false)
-		})
 	}
 }
 
+func testDir(t *testing.T, dir string, manual bool) {
+	testenv.MustHaveGoBuild(t)
+
+	fis, err := os.ReadDir(dir)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	var filenames []string
+	for _, fi := range fis {
+		filenames = append(filenames, filepath.Join(dir, fi.Name()))
+	}
+
+	t.Run(filepath.Base(dir), func(t *testing.T) {
+		testPkg(t, filenames, manual)
+	})
+}
+
 // TODO(rFindley) reconcile the different test setup in go/types with types2.
-func testPkg(t *testing.T, filenames []string, goVersion string, manual bool) {
+func testPkg(t *testing.T, filenames []string, manual bool) {
 	srcs := make([][]byte, len(filenames))
 	for i, filename := range filenames {
 		src, err := os.ReadFile(filename)
@@ -377,5 +418,5 @@ func testPkg(t *testing.T, filenames []string, goVersion string, manual bool) {
 		}
 		srcs[i] = src
 	}
-	checkFiles(t, nil, goVersion, filenames, srcs, manual)
+	testFiles(t, nil, filenames, srcs, manual, nil)
 }
diff --git a/src/go/types/conversions.go b/src/go/types/conversions.go
index ad6d3eef102..a1fcdd4fd8d 100644
--- a/src/go/types/conversions.go
+++ b/src/go/types/conversions.go
@@ -94,7 +94,7 @@ func (x *operand) convertibleTo(check *Checker, T Type, reason *string) bool {
 	V := x.typ
 	Vu := under(V)
 	Tu := under(T)
-	if check.identicalIgnoreTags(Vu, Tu) {
+	if IdenticalIgnoreTags(Vu, Tu) {
 		return true
 	}
 
@@ -102,7 +102,7 @@ func (x *operand) convertibleTo(check *Checker, T Type, reason *string) bool {
 	// have identical underlying types if tags are ignored"
 	if V, ok := V.(*Pointer); ok {
 		if T, ok := T.(*Pointer); ok {
-			if check.identicalIgnoreTags(under(V.base), under(T.base)) {
+			if IdenticalIgnoreTags(under(V.base), under(T.base)) {
 				return true
 			}
 		}
@@ -143,7 +143,7 @@ func (x *operand) convertibleTo(check *Checker, T Type, reason *string) bool {
 	if s := asSlice(V); s != nil {
 		if p := asPointer(T); p != nil {
 			if a := asArray(p.Elem()); a != nil {
-				if check.identical(s.Elem(), a.Elem()) {
+				if Identical(s.Elem(), a.Elem()) {
 					if check == nil || check.allowVersion(check.pkg, 1, 17) {
 						return true
 					}
diff --git a/src/go/types/decl.go b/src/go/types/decl.go
index 5f38a346cee..831b1da5896 100644
--- a/src/go/types/decl.go
+++ b/src/go/types/decl.go
@@ -317,6 +317,7 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 		}
 
 	case *Named:
+		t.expand()
 		// don't touch the type if it is from a different package or the Universe scope
 		// (doing so would lead to a race condition - was issue #35049)
 		if t.obj.pkg != check.pkg {
@@ -333,7 +334,7 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 		switch t.info {
 		case unknown:
 			t.info = marked
-			t.info = check.validType(t.orig, append(path, t.obj)) // only types of current package added to path
+			t.info = check.validType(t.fromRHS, append(path, t.obj)) // only types of current package added to path
 		case marked:
 			// cycle detected
 			for i, tn := range path {
@@ -349,9 +350,6 @@ func (check *Checker) validType(typ Type, path []Object) typeInfo {
 			panic("internal error: cycle start not found")
 		}
 		return t.info
-
-	case *instance:
-		return check.validType(t.expand(), path)
 	}
 
 	return valid
@@ -569,75 +567,6 @@ func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init ast.Expr) {
 	check.initVars(lhs, []ast.Expr{init}, token.NoPos)
 }
 
-// under returns the expanded underlying type of n0; possibly by following
-// forward chains of named types. If an underlying type is found, resolve
-// the chain by setting the underlying type for each defined type in the
-// chain before returning it. If no underlying type is found or a cycle
-// is detected, the result is Typ[Invalid]. If a cycle is detected and
-// n0.check != nil, the cycle is reported.
-func (n0 *Named) under() Type {
-	u := n0.underlying
-	if u == nil {
-		return Typ[Invalid]
-	}
-
-	// If the underlying type of a defined type is not a defined
-	// type, then that is the desired underlying type.
-	n := asNamed(u)
-	if n == nil {
-		return u // common case
-	}
-
-	// Otherwise, follow the forward chain.
-	seen := map[*Named]int{n0: 0}
-	path := []Object{n0.obj}
-	for {
-		u = n.underlying
-		if u == nil {
-			u = Typ[Invalid]
-			break
-		}
-		n1 := asNamed(u)
-		if n1 == nil {
-			break // end of chain
-		}
-
-		seen[n] = len(seen)
-		path = append(path, n.obj)
-		n = n1
-
-		if i, ok := seen[n]; ok {
-			// cycle
-			// TODO(rFindley) revert this to a method on Checker. Having a possibly
-			// nil Checker on Named and TypeParam is too subtle.
-			if n0.check != nil {
-				n0.check.cycleError(path[i:])
-			}
-			u = Typ[Invalid]
-			break
-		}
-	}
-
-	for n := range seen {
-		// We should never have to update the underlying type of an imported type;
-		// those underlying types should have been resolved during the import.
-		// Also, doing so would lead to a race condition (was issue #31749).
-		// Do this check always, not just in debug more (it's cheap).
-		if n0.check != nil && n.obj.pkg != n0.check.pkg {
-			panic("internal error: imported type with unresolved underlying type")
-		}
-		n.underlying = u
-	}
-
-	return u
-}
-
-func (n *Named) setUnderlying(typ Type) {
-	if n != nil {
-		n.underlying = typ
-	}
-}
-
 func (check *Checker) typeDecl(obj *TypeName, tdecl *ast.TypeSpec, def *Named) {
 	assert(obj.typ == nil)
 
@@ -653,58 +582,57 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *ast.TypeSpec, def *Named) {
 		alias = false
 	}
 
+	// alias declaration
 	if alias {
-		// type alias declaration
 		if !check.allowVersion(check.pkg, 1, 9) {
 			check.errorf(atPos(tdecl.Assign), _BadDecl, "type aliases requires go1.9 or later")
 		}
 
 		obj.typ = Typ[Invalid]
 		obj.typ = check.anyType(tdecl.Type)
-
-	} else {
-		// defined type declaration
-
-		named := &Named{check: check, obj: obj}
-		def.setUnderlying(named)
-		obj.typ = named // make sure recursive type declarations terminate
-
-		if tparams := typeparams.Get(tdecl); tparams != nil {
-			check.openScope(tdecl, "type parameters")
-			defer check.closeScope()
-			named.tparams = check.collectTypeParams(tparams)
-		}
-
-		// determine underlying type of named
-		named.orig = check.definedType(tdecl.Type, named)
-
-		// The underlying type of named may be itself a named type that is
-		// incomplete:
-		//
-		//	type (
-		//		A B
-		//		B *C
-		//		C A
-		//	)
-		//
-		// The type of C is the (named) type of A which is incomplete,
-		// and which has as its underlying type the named type B.
-		// Determine the (final, unnamed) underlying type by resolving
-		// any forward chain.
-		// TODO(gri) Investigate if we can just use named.origin here
-		//           and rely on lazy computation of the underlying type.
-		named.underlying = under(named)
-	}
-
-}
-
-func (check *Checker) collectTypeParams(list *ast.FieldList) (tparams []*TypeName) {
-	// Type parameter lists should not be empty. The parser will
-	// complain but we still may get an incorrect AST: ignore it.
-	if list.NumFields() == 0 {
 		return
 	}
 
+	// type definition or generic type declaration
+	named := check.newNamed(obj, nil, nil, nil, nil)
+	def.setUnderlying(named)
+
+	if tparams := typeparams.Get(tdecl); tparams != nil {
+		check.openScope(tdecl, "type parameters")
+		defer check.closeScope()
+		named.tparams = check.collectTypeParams(tparams)
+	}
+
+	// determine underlying type of named
+	named.fromRHS = check.definedType(tdecl.Type, named)
+	assert(named.fromRHS != nil)
+
+	// The underlying type of named may be itself a named type that is
+	// incomplete:
+	//
+	//	type (
+	//		A B
+	//		B *C
+	//		C A
+	//	)
+	//
+	// The type of C is the (named) type of A which is incomplete,
+	// and which has as its underlying type the named type B.
+	// Determine the (final, unnamed) underlying type by resolving
+	// any forward chain.
+	// TODO(gri) Investigate if we can just use named.fromRHS here
+	//           and rely on lazy computation of the underlying type.
+	named.underlying = under(named)
+
+	// If the RHS is a type parameter, it must be from this type declaration.
+	if tpar, _ := named.underlying.(*TypeParam); tpar != nil && tparamIndex(named.TParams().list(), tpar) < 0 {
+		check.errorf(tdecl.Type, _Todo, "cannot use function type parameter %s as RHS in type declaration", tpar)
+		named.underlying = Typ[Invalid]
+	}
+}
+
+func (check *Checker) collectTypeParams(list *ast.FieldList) *TypeParams {
+	var tparams []*TypeName
 	// Declare type parameters up-front, with empty interface as type bound.
 	// The scope of type parameters starts at the beginning of the type parameter
 	// list (so we can have mutually recursive parameterized interfaces).
@@ -712,52 +640,28 @@ func (check *Checker) collectTypeParams(list *ast.FieldList) (tparams []*TypeNam
 		tparams = check.declareTypeParams(tparams, f.Names)
 	}
 
-	setBoundAt := func(at int, bound Type) {
-		assert(IsInterface(bound))
-		tparams[at].typ.(*_TypeParam).bound = bound
-	}
-
 	index := 0
 	var bound Type
 	for _, f := range list.List {
 		if f.Type == nil {
 			goto next
 		}
-
-		// The predeclared identifier "any" is visible only as a constraint
-		// in a type parameter list. Look for it before general constraint
-		// resolution.
-		if tident, _ := unparen(f.Type).(*ast.Ident); tident != nil && tident.Name == "any" && check.lookup("any") == nil {
-			bound = universeAny
-		} else {
-			bound = check.typ(f.Type)
-		}
-
-		// type bound must be an interface
-		// TODO(gri) We should delay the interface check because
-		//           we may not have a complete interface yet:
-		//           type C(type T C) interface {}
-		//           (issue #39724).
-		if _, ok := under(bound).(*Interface); ok {
-			// Otherwise, set the bound for each type parameter.
-			for i := range f.Names {
-				setBoundAt(index+i, bound)
-			}
-		} else if bound != Typ[Invalid] {
-			check.errorf(f.Type, _Todo, "%s is not an interface", bound)
+		bound = check.boundType(f.Type)
+		for i := range f.Names {
+			tparams[index+i].typ.(*TypeParam).bound = bound
 		}
 
 	next:
 		index += len(f.Names)
 	}
 
-	return
+	return bindTParams(tparams)
 }
 
 func (check *Checker) declareTypeParams(tparams []*TypeName, names []*ast.Ident) []*TypeName {
 	for _, name := range names {
 		tpar := NewTypeName(name.Pos(), check.pkg, name.Name, nil)
-		check.newTypeParam(tpar, len(tparams), &emptyInterface) // assigns type to tpar as a side-effect
+		check.NewTypeParam(tpar, &emptyInterface)               // assigns type to tpar as a side-effect
 		check.declare(check.scope, name, tpar, check.scope.pos) // TODO(gri) check scope position
 		tparams = append(tparams, tpar)
 	}
@@ -769,6 +673,25 @@ func (check *Checker) declareTypeParams(tparams []*TypeName, names []*ast.Ident)
 	return tparams
 }
 
+// boundType type-checks the type expression e and returns its type, or Typ[Invalid].
+// The type must be an interface, including the predeclared type "any".
+func (check *Checker) boundType(e ast.Expr) Type {
+	// The predeclared identifier "any" is visible only as a type bound in a type parameter list.
+	// If we allow "any" for general use, this if-statement can be removed (issue #33232).
+	if name, _ := unparen(e).(*ast.Ident); name != nil && name.Name == "any" && check.lookup("any") == universeAny {
+		return universeAny.Type()
+	}
+
+	bound := check.typ(e)
+	check.later(func() {
+		u := under(bound)
+		if _, ok := u.(*Interface); !ok && u != Typ[Invalid] {
+			check.errorf(e, _Todo, "%s is not an interface", bound)
+		}
+	})
+	return bound
+}
+
 func (check *Checker) collectMethods(obj *TypeName) {
 	// get associated methods
 	// (Checker.collectObjects only collects methods with non-blank names;
@@ -788,7 +711,7 @@ func (check *Checker) collectMethods(obj *TypeName) {
 	// and field names must be distinct."
 	base := asNamed(obj.typ) // shouldn't fail but be conservative
 	if base != nil {
-		if t, _ := base.underlying.(*Struct); t != nil {
+		if t, _ := base.Underlying().(*Struct); t != nil {
 			for _, fld := range t.fields {
 				if fld.name != "_" {
 					assert(mset.insert(fld) == nil)
@@ -824,6 +747,7 @@ func (check *Checker) collectMethods(obj *TypeName) {
 		}
 
 		if base != nil {
+			base.load() // TODO(mdempsky): Probably unnecessary.
 			base.methods = append(base.methods, m)
 		}
 	}
diff --git a/src/go/types/errorcodes.go b/src/go/types/errorcodes.go
index 3d24da7b533..bcc850f7538 100644
--- a/src/go/types/errorcodes.go
+++ b/src/go/types/errorcodes.go
@@ -281,16 +281,7 @@ const (
 	_IncomparableMapKey
 
 	// _InvalidIfaceEmbed occurs when a non-interface type is embedded in an
-	// interface.
-	//
-	// Example:
-	//  type T struct {}
-	//
-	//  func (T) m()
-	//
-	//  type I interface {
-	//  	T
-	//  }
+	// interface (for go 1.17 or earlier).
 	_InvalidIfaceEmbed
 
 	// _InvalidPtrEmbed occurs when an embedded field is of the pointer form *T,
@@ -884,7 +875,7 @@ const (
 	// context in which it is used.
 	//
 	// Example:
-	//  var _ = 1 + ""
+	//  var _ = 1 + nil
 	_InvalidUntypedConversion
 
 	// _BadOffsetofSyntax occurs when unsafe.Offsetof is called with an argument
diff --git a/src/go/types/errors.go b/src/go/types/errors.go
index 19e9ae8d44a..22631064173 100644
--- a/src/go/types/errors.go
+++ b/src/go/types/errors.go
@@ -31,7 +31,7 @@ func (check *Checker) qualifier(pkg *Package) string {
 		if check.pkgPathMap == nil {
 			check.pkgPathMap = make(map[string]map[string]bool)
 			check.seenPkgMap = make(map[*Package]bool)
-			check.markImports(pkg)
+			check.markImports(check.pkg)
 		}
 		// If the same package name was used by multiple packages, display the full path.
 		if len(check.pkgPathMap[pkg.name]) > 1 {
diff --git a/src/go/types/expr.go b/src/go/types/expr.go
index 5c65fad4479..c9a55aa871e 100644
--- a/src/go/types/expr.go
+++ b/src/go/types/expr.go
@@ -144,6 +144,14 @@ var op2str2 = [...]string{
 	token.SHL: "shift",
 }
 
+func underIs(typ Type, f func(Type) bool) bool {
+	u := under(typ)
+	if tpar, _ := u.(*TypeParam); tpar != nil {
+		return tpar.underIs(f)
+	}
+	return f(u)
+}
+
 // The unary expression e may be nil. It's passed in for better error messages only.
 func (check *Checker) unary(x *operand, e *ast.UnaryExpr) {
 	check.expr(x, e.X)
@@ -164,19 +172,29 @@ func (check *Checker) unary(x *operand, e *ast.UnaryExpr) {
 		return
 
 	case token.ARROW:
-		typ := asChan(x.typ)
-		if typ == nil {
-			check.invalidOp(x, _InvalidReceive, "cannot receive from non-channel %s", x)
-			x.mode = invalid
-			return
-		}
-		if typ.dir == SendOnly {
-			check.invalidOp(x, _InvalidReceive, "cannot receive from send-only channel %s", x)
+		var elem Type
+		if !underIs(x.typ, func(u Type) bool {
+			ch, _ := u.(*Chan)
+			if ch == nil {
+				check.invalidOp(x, _InvalidReceive, "cannot receive from non-channel %s", x)
+				return false
+			}
+			if ch.dir == SendOnly {
+				check.invalidOp(x, _InvalidReceive, "cannot receive from send-only channel %s", x)
+				return false
+			}
+			if elem != nil && !Identical(ch.elem, elem) {
+				check.invalidOp(x, _Todo, "channels of %s must have the same element type", x)
+				return false
+			}
+			elem = ch.elem
+			return true
+		}) {
 			x.mode = invalid
 			return
 		}
 		x.mode = commaok
-		x.typ = typ.elem
+		x.typ = elem
 		check.hasCallOrRecv = true
 		return
 	}
@@ -622,7 +640,7 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 		return x.typ, nil, 0
 	}
 
-	switch t := optype(target).(type) {
+	switch t := under(target).(type) {
 	case *Basic:
 		if x.mode == constant_ {
 			v, code := check.representation(x, t)
@@ -661,8 +679,8 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 		default:
 			return nil, nil, _InvalidUntypedConversion
 		}
-	case *_Sum:
-		ok := t.is(func(t Type) bool {
+	case *TypeParam:
+		ok := t.underIs(func(t Type) bool {
 			target, _, _ := check.implicitTypeAndValue(x, t)
 			return target != nil
 		})
@@ -682,7 +700,6 @@ func (check *Checker) implicitTypeAndValue(x *operand, target Type) (Type, const
 			return Typ[UntypedNil], nil, 0
 		}
 		// cannot assign untyped values to non-empty interfaces
-		check.completeInterface(token.NoPos, t)
 		if !t.Empty() {
 			return nil, nil, _InvalidUntypedConversion
 		}
@@ -778,32 +795,48 @@ func (check *Checker) shift(x, y *operand, e ast.Expr, op token.Token) {
 	// spec: "The right operand in a shift expression must have integer type
 	// or be an untyped constant representable by a value of type uint."
 
-	// Provide a good error message for negative shift counts.
+	// Check that constants are representable by uint, but do not convert them
+	// (see also issue #47243).
 	if y.mode == constant_ {
+		// Provide a good error message for negative shift counts.
 		yval := constant.ToInt(y.val) // consider -1, 1.0, but not -1.1
 		if yval.Kind() == constant.Int && constant.Sign(yval) < 0 {
 			check.invalidOp(y, _InvalidShiftCount, "negative shift count %s", y)
 			x.mode = invalid
 			return
 		}
+
+		if isUntyped(y.typ) {
+			// Caution: Check for representability here, rather than in the switch
+			// below, because isInteger includes untyped integers (was bug #43697).
+			check.representable(y, Typ[Uint])
+			if y.mode == invalid {
+				x.mode = invalid
+				return
+			}
+		}
 	}
 
-	// Caution: Check for isUntyped first because isInteger includes untyped
-	//          integers (was bug #43697).
-	if isUntyped(y.typ) {
+	// Check that RHS is otherwise at least of integer type.
+	switch {
+	case isInteger(y.typ):
+		if !isUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) {
+			check.invalidOp(y, _InvalidShiftCount, "signed shift count %s requires go1.13 or later", y)
+			x.mode = invalid
+			return
+		}
+	case isUntyped(y.typ):
+		// This is incorrect, but preserves pre-existing behavior.
+		// See also bug #47410.
 		check.convertUntyped(y, Typ[Uint])
 		if y.mode == invalid {
 			x.mode = invalid
 			return
 		}
-	} else if !isInteger(y.typ) {
+	default:
 		check.invalidOp(y, _InvalidShiftCount, "shift count %s must be integer", y)
 		x.mode = invalid
 		return
-	} else if !isUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) {
-		check.invalidOp(y, _InvalidShiftCount, "signed shift count %s requires go1.13 or later", y)
-		x.mode = invalid
-		return
 	}
 
 	if x.mode == constant_ {
@@ -927,14 +960,28 @@ func (check *Checker) binary(x *operand, e ast.Expr, lhs, rhs ast.Expr, op token
 		return
 	}
 
-	check.convertUntyped(x, y.typ)
-	if x.mode == invalid {
-		return
+	canMix := func(x, y *operand) bool {
+		if IsInterface(x.typ) || IsInterface(y.typ) {
+			return true
+		}
+		if isBoolean(x.typ) != isBoolean(y.typ) {
+			return false
+		}
+		if isString(x.typ) != isString(y.typ) {
+			return false
+		}
+		return true
 	}
-	check.convertUntyped(&y, x.typ)
-	if y.mode == invalid {
-		x.mode = invalid
-		return
+	if canMix(x, &y) {
+		check.convertUntyped(x, y.typ)
+		if x.mode == invalid {
+			return
+		}
+		check.convertUntyped(&y, x.typ)
+		if y.mode == invalid {
+			x.mode = invalid
+			return
+		}
 	}
 
 	if isComparison(op) {
@@ -942,7 +989,7 @@ func (check *Checker) binary(x *operand, e ast.Expr, lhs, rhs ast.Expr, op token
 		return
 	}
 
-	if !check.identical(x.typ, y.typ) {
+	if !Identical(x.typ, y.typ) {
 		// only report an error if we have valid types
 		// (otherwise we had an error reported elsewhere already)
 		if x.typ != Typ[Invalid] && y.typ != Typ[Invalid] {
@@ -1138,7 +1185,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 			goto Error
 		}
 
-		switch utyp := optype(base).(type) {
+		switch utyp := under(base).(type) {
 		case *Struct:
 			if len(e.Elts) == 0 {
 				break
@@ -1268,7 +1315,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 					xkey := keyVal(x.val)
 					if asInterface(utyp.key) != nil {
 						for _, vtyp := range visited[xkey] {
-							if check.identical(vtyp, x.typ) {
+							if Identical(vtyp, x.typ) {
 								duplicate = true
 								break
 							}
@@ -1317,9 +1364,10 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 	case *ast.SelectorExpr:
 		check.selector(x, e)
 
-	case *ast.IndexExpr:
-		if check.indexExpr(x, e) {
-			check.funcInst(x, e)
+	case *ast.IndexExpr, *ast.MultiIndexExpr:
+		ix := typeparams.UnpackIndexExpr(e)
+		if check.indexExpr(x, ix) {
+			check.funcInst(x, ix)
 		}
 		if x.mode == invalid {
 			goto Error
@@ -1368,13 +1416,24 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 		case typexpr:
 			x.typ = &Pointer{base: x.typ}
 		default:
-			if typ := asPointer(x.typ); typ != nil {
-				x.mode = variable
-				x.typ = typ.base
-			} else {
-				check.invalidOp(x, _InvalidIndirection, "cannot indirect %s", x)
+			var base Type
+			if !underIs(x.typ, func(u Type) bool {
+				p, _ := u.(*Pointer)
+				if p == nil {
+					check.invalidOp(x, _InvalidIndirection, "cannot indirect %s", x)
+					return false
+				}
+				if base != nil && !Identical(p.base, base) {
+					check.invalidOp(x, _Todo, "pointers of %s must have identical base types", x)
+					return false
+				}
+				base = p.base
+				return true
+			}) {
 				goto Error
 			}
+			x.mode = variable
+			x.typ = base
 		}
 
 	case *ast.UnaryExpr:
@@ -1409,12 +1468,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 		// types, which are comparatively rare.
 
 	default:
-		if typeparams.IsListExpr(e) {
-			// catch-all for unexpected expression lists
-			check.errorf(e, _Todo, "unexpected list of expressions")
-		} else {
-			panic(fmt.Sprintf("%s: unknown expression type %T", check.fset.Position(e.Pos()), e))
-		}
+		panic(fmt.Sprintf("%s: unknown expression type %T", check.fset.Position(e.Pos()), e))
 	}
 
 	// everything went well
@@ -1459,7 +1513,7 @@ func (check *Checker) typeAssertion(at positioner, x *operand, xtyp *Interface,
 	}
 	var msg string
 	if wrongType != nil {
-		if check.identical(method.typ, wrongType.typ) {
+		if Identical(method.typ, wrongType.typ) {
 			msg = fmt.Sprintf("missing method %s (%s has pointer receiver)", method.name, method.name)
 		} else {
 			msg = fmt.Sprintf("wrong type for method %s (have %s, want %s)", method.name, wrongType.typ, method.typ)
diff --git a/src/go/types/exprstring.go b/src/go/types/exprstring.go
index f05e6424d44..aee8a5ba5f7 100644
--- a/src/go/types/exprstring.go
+++ b/src/go/types/exprstring.go
@@ -67,11 +67,11 @@ func WriteExpr(buf *bytes.Buffer, x ast.Expr) {
 		buf.WriteByte('.')
 		buf.WriteString(x.Sel.Name)
 
-	case *ast.IndexExpr:
-		WriteExpr(buf, x.X)
+	case *ast.IndexExpr, *ast.MultiIndexExpr:
+		ix := typeparams.UnpackIndexExpr(x)
+		WriteExpr(buf, ix.X)
 		buf.WriteByte('[')
-		exprs := typeparams.UnpackExpr(x.Index)
-		for i, e := range exprs {
+		for i, e := range ix.Indices {
 			if i > 0 {
 				buf.WriteString(", ")
 			}
diff --git a/src/go/types/exprstring_test.go b/src/go/types/exprstring_test.go
index 51102881c9f..a67f6a978a9 100644
--- a/src/go/types/exprstring_test.go
+++ b/src/go/types/exprstring_test.go
@@ -27,6 +27,40 @@ var testExprs = []testEntry{
 	{"func(x int) complex128 {}", "(func(x int) complex128 literal)"},
 	{"[]int{1, 2, 3}", "([]int literal)"},
 
+	// type expressions
+	dup("[1 << 10]byte"),
+	dup("[]int"),
+	dup("*int"),
+	dup("struct{x int}"),
+	dup("func()"),
+	dup("func(int, float32) string"),
+	dup("interface{m()}"),
+	dup("interface{m() string; n(x int)}"),
+	dup("interface{type int}"),
+
+	// The following exprs do not get formatted correctly: each element in the
+	// type list is printed on a separate line. This is left as a placeholder
+	// until type lists are removed.
+	// TODO(rfindley): remove this once type lists are gone.
+	// dup("interface{type int, float64, string}"),
+	// dup("interface{type int; m()}"),
+	// dup("interface{type int, float64, string; m() string; n(x int)}"),
+	dup("map[string]int"),
+	dup("chan E"),
+	dup("<-chan E"),
+	dup("chan<- E"),
+
+	// new interfaces
+	dup("interface{int}"),
+	dup("interface{~int}"),
+	dup("interface{~int}"),
+	dup("interface{int | string}"),
+	dup("interface{~int | ~string; float64; m()}"),
+
+	// See above.
+	// dup("interface{type a, b, c; ~int | ~string; float64; m()}"),
+	dup("interface{~T[int, string] | string}"),
+
 	// non-type expressions
 	dup("(x)"),
 	dup("x.f"),
diff --git a/src/go/types/index.go b/src/go/types/index.go
index 2ba3475f897..a49bc5519cf 100644
--- a/src/go/types/index.go
+++ b/src/go/types/index.go
@@ -15,25 +15,25 @@ import (
 // If e is a valid function instantiation, indexExpr returns true.
 // In that case x represents the uninstantiated function value and
 // it is the caller's responsibility to instantiate the function.
-func (check *Checker) indexExpr(x *operand, e *ast.IndexExpr) (isFuncInst bool) {
+func (check *Checker) indexExpr(x *operand, e *typeparams.IndexExpr) (isFuncInst bool) {
 	check.exprOrType(x, e.X)
 
 	switch x.mode {
 	case invalid:
-		check.use(typeparams.UnpackExpr(e.Index)...)
+		check.use(e.Indices...)
 		return false
 
 	case typexpr:
 		// type instantiation
 		x.mode = invalid
-		x.typ = check.varType(e)
+		x.typ = check.varType(e.Orig)
 		if x.typ != Typ[Invalid] {
 			x.mode = typexpr
 		}
 		return false
 
 	case value:
-		if sig := asSignature(x.typ); sig != nil && len(sig.tparams) > 0 {
+		if sig := asSignature(x.typ); sig != nil && sig.TParams().Len() > 0 {
 			// function instantiation
 			return true
 		}
@@ -41,7 +41,7 @@ func (check *Checker) indexExpr(x *operand, e *ast.IndexExpr) (isFuncInst bool)
 
 	valid := false
 	length := int64(-1) // valid if >= 0
-	switch typ := optype(x.typ).(type) {
+	switch typ := under(x.typ).(type) {
 	case *Basic:
 		if isString(typ) {
 			valid = true
@@ -80,7 +80,7 @@ func (check *Checker) indexExpr(x *operand, e *ast.IndexExpr) (isFuncInst bool)
 		index := check.singleIndex(e)
 		if index == nil {
 			x.mode = invalid
-			return
+			return false
 		}
 		var key operand
 		check.expr(&key, index)
@@ -88,88 +88,81 @@ func (check *Checker) indexExpr(x *operand, e *ast.IndexExpr) (isFuncInst bool)
 		// ok to continue even if indexing failed - map element type is known
 		x.mode = mapindex
 		x.typ = typ.elem
-		x.expr = e
-		return
+		x.expr = e.Orig
+		return false
 
-	case *_Sum:
-		// A sum type can be indexed if all of the sum's types
-		// support indexing and have the same index and element
-		// type. Special rules apply for maps in the sum type.
-		var tkey, telem Type // key is for map types only
-		nmaps := 0           // number of map types in sum type
-		if typ.is(func(t Type) bool {
-			var e Type
-			switch t := under(t).(type) {
+	case *TypeParam:
+		// TODO(gri) report detailed failure cause for better error messages
+		var tkey, telem Type // tkey != nil if we have maps
+		if typ.underIs(func(u Type) bool {
+			var key, elem Type
+			alen := int64(-1) // valid if >= 0
+			switch t := u.(type) {
 			case *Basic:
-				if isString(t) {
-					e = universeByte
-				}
-			case *Array:
-				e = t.elem
-			case *Pointer:
-				if t := asArray(t.base); t != nil {
-					e = t.elem
-				}
-			case *Slice:
-				e = t.elem
-			case *Map:
-				// If there are multiple maps in the sum type,
-				// they must have identical key types.
-				// TODO(gri) We may be able to relax this rule
-				// but it becomes complicated very quickly.
-				if tkey != nil && !Identical(t.key, tkey) {
+				if !isString(t) {
 					return false
 				}
-				tkey = t.key
-				e = t.elem
-				nmaps++
-			case *_TypeParam:
-				check.errorf(x, 0, "type of %s contains a type parameter - cannot index (implementation restriction)", x)
-			case *instance:
-				panic("unimplemented")
-			}
-			if e == nil || telem != nil && !Identical(e, telem) {
+				elem = universeByte
+			case *Array:
+				elem = t.elem
+				alen = t.len
+			case *Pointer:
+				a, _ := under(t.base).(*Array)
+				if a == nil {
+					return false
+				}
+				elem = a.elem
+				alen = a.len
+			case *Slice:
+				elem = t.elem
+			case *Map:
+				key = t.key
+				elem = t.elem
+			default:
 				return false
 			}
-			telem = e
+			assert(elem != nil)
+			if telem == nil {
+				// first type
+				tkey, telem = key, elem
+				length = alen
+			} else {
+				// all map keys must be identical (incl. all nil)
+				if !Identical(key, tkey) {
+					return false
+				}
+				// all element types must be identical
+				if !Identical(elem, telem) {
+					return false
+				}
+				tkey, telem = key, elem
+				// track the minimal length for arrays
+				if alen >= 0 && alen < length {
+					length = alen
+				}
+			}
 			return true
 		}) {
-			// If there are maps, the index expression must be assignable
-			// to the map key type (as for simple map index expressions).
-			if nmaps > 0 {
+			// For maps, the index expression must be assignable to the map key type.
+			if tkey != nil {
 				index := check.singleIndex(e)
 				if index == nil {
 					x.mode = invalid
-					return
+					return false
 				}
 				var key operand
 				check.expr(&key, index)
 				check.assignment(&key, tkey, "map index")
 				// ok to continue even if indexing failed - map element type is known
-
-				// If there are only maps, we are done.
-				if nmaps == len(typ.types) {
-					x.mode = mapindex
-					x.typ = telem
-					x.expr = e
-					return
-				}
-
-				// Otherwise we have mix of maps and other types. For
-				// now we require that the map key be an integer type.
-				// TODO(gri) This is probably not good enough.
-				valid = isInteger(tkey)
-				// avoid 2nd indexing error if indexing failed above
-				if !valid && key.mode == invalid {
-					x.mode = invalid
-					return
-				}
-				x.mode = value // map index expressions are not addressable
-			} else {
-				// no maps
-				valid = true
-				x.mode = variable
+				x.mode = mapindex
+				x.typ = telem
+				x.expr = e
+				return false
 			}
+
+			// no maps
+			valid = true
+			x.mode = variable
 			x.typ = telem
 		}
 	}
@@ -177,13 +170,13 @@ func (check *Checker) indexExpr(x *operand, e *ast.IndexExpr) (isFuncInst bool)
 	if !valid {
 		check.invalidOp(x, _NonIndexableOperand, "cannot index %s", x)
 		x.mode = invalid
-		return
+		return false
 	}
 
 	index := check.singleIndex(e)
 	if index == nil {
 		x.mode = invalid
-		return
+		return false
 	}
 
 	// In pathological (invalid) cases (e.g.: type T1 [][[]T1{}[0][0]]T0)
@@ -206,7 +199,7 @@ func (check *Checker) sliceExpr(x *operand, e *ast.SliceExpr) {
 
 	valid := false
 	length := int64(-1) // valid if >= 0
-	switch typ := optype(x.typ).(type) {
+	switch typ := under(x.typ).(type) {
 	case *Basic:
 		if isString(typ) {
 			if e.Slice3 {
@@ -246,8 +239,8 @@ func (check *Checker) sliceExpr(x *operand, e *ast.SliceExpr) {
 		valid = true
 		// x.typ doesn't change
 
-	case *_Sum, *_TypeParam:
-		check.errorf(x, 0, "generic slice expressions not yet implemented")
+	case *TypeParam:
+		check.errorf(x, _Todo, "generic slice expressions not yet implemented")
 		x.mode = invalid
 		return
 	}
@@ -311,23 +304,16 @@ L:
 // singleIndex returns the (single) index from the index expression e.
 // If the index is missing, or if there are multiple indices, an error
 // is reported and the result is nil.
-func (check *Checker) singleIndex(e *ast.IndexExpr) ast.Expr {
-	index := e.Index
-	if index == nil {
-		check.invalidAST(e, "missing index for %s", e)
+func (check *Checker) singleIndex(expr *typeparams.IndexExpr) ast.Expr {
+	if len(expr.Indices) == 0 {
+		check.invalidAST(expr.Orig, "index expression %v with 0 indices", expr)
 		return nil
 	}
-
-	indexes := typeparams.UnpackExpr(index)
-	if len(indexes) == 0 {
-		check.invalidAST(index, "index expression %v with 0 indices", index)
-		return nil
-	}
-	if len(indexes) > 1 {
+	if len(expr.Indices) > 1 {
 		// TODO(rFindley) should this get a distinct error code?
-		check.invalidOp(indexes[1], _InvalidIndex, "more than one index")
+		check.invalidOp(expr.Indices[1], _InvalidIndex, "more than one index")
 	}
-	return indexes[0]
+	return expr.Indices[0]
 }
 
 // index checks an index expression for validity.
diff --git a/src/go/types/infer.go b/src/go/types/infer.go
index 5d49351e1f0..6e70a103e72 100644
--- a/src/go/types/infer.go
+++ b/src/go/types/infer.go
@@ -93,7 +93,7 @@ func (check *Checker) infer(posn positioner, tparams []*TypeName, targs []Type,
 	// Unify parameter and argument types for generic parameters with typed arguments
 	// and collect the indices of generic parameters with untyped arguments.
 	// Terminology: generic parameter = function parameter with a type-parameterized type
-	u := newUnifier(check, false)
+	u := newUnifier(false)
 	u.x.init(tparams)
 
 	// Set the type arguments which we know already.
@@ -189,7 +189,7 @@ func (check *Checker) infer(posn positioner, tparams []*TypeName, targs []Type,
 		// only parameter type it can possibly match against is a *TypeParam.
 		// Thus, only consider untyped arguments for generic parameters that
 		// are not of composite types and which don't have a type inferred yet.
-		if tpar, _ := par.typ.(*_TypeParam); tpar != nil && targs[tpar.index] == nil {
+		if tpar, _ := par.typ.(*TypeParam); tpar != nil && targs[tpar.index] == nil {
 			arg := args[i]
 			targ := Default(arg.typ)
 			// The default type for an untyped nil is untyped nil. We must not
@@ -302,8 +302,8 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 			}
 		}
 
-	case *_Sum:
-		return w.isParameterizedList(t.types)
+	case *Union:
+		return w.isParameterizedTermList(t.terms)
 
 	case *Signature:
 		// t.tparams may not be nil if we are looking at a signature
@@ -316,24 +316,13 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 		return w.isParameterized(t.params) || w.isParameterized(t.results)
 
 	case *Interface:
-		if t.allMethods != nil {
-			// TODO(rFindley) at some point we should enforce completeness here
-			for _, m := range t.allMethods {
-				if w.isParameterized(m.typ) {
-					return true
-				}
+		tset := t.typeSet()
+		for _, m := range tset.methods {
+			if w.isParameterized(m.typ) {
+				return true
 			}
-			return w.isParameterizedList(unpackType(t.allTypes))
 		}
-
-		return t.iterate(func(t *Interface) bool {
-			for _, m := range t.methods {
-				if w.isParameterized(m.typ) {
-					return true
-				}
-			}
-			return w.isParameterizedList(unpackType(t.types))
-		}, nil)
+		return w.isParameterized(tset.types)
 
 	case *Map:
 		return w.isParameterized(t.key) || w.isParameterized(t.elem)
@@ -342,15 +331,12 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 		return w.isParameterized(t.elem)
 
 	case *Named:
-		return w.isParameterizedList(t.targs)
+		return w.isParameterizedTypeList(t.targs)
 
-	case *_TypeParam:
+	case *TypeParam:
 		// t must be one of w.tparams
 		return t.index < len(w.tparams) && w.tparams[t.index].typ == t
 
-	case *instance:
-		return w.isParameterizedList(t.targs)
-
 	default:
 		unreachable()
 	}
@@ -358,7 +344,7 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
 	return false
 }
 
-func (w *tpWalker) isParameterizedList(list []Type) bool {
+func (w *tpWalker) isParameterizedTypeList(list []Type) bool {
 	for _, t := range list {
 		if w.isParameterized(t) {
 			return true
@@ -367,6 +353,15 @@ func (w *tpWalker) isParameterizedList(list []Type) bool {
 	return false
 }
 
+func (w *tpWalker) isParameterizedTermList(list []*term) bool {
+	for _, t := range list {
+		if w.isParameterized(t.typ) {
+			return true
+		}
+	}
+	return false
+}
+
 // inferB returns the list of actual type arguments inferred from the type parameters'
 // bounds and an initial set of type arguments. If type inference is impossible because
 // unification fails, an error is reported if report is set to true, the resulting types
@@ -380,7 +375,7 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	// Setup bidirectional unification between those structural bounds
 	// and the corresponding type arguments (which may be nil!).
-	u := newUnifier(check, false)
+	u := newUnifier(false)
 	u.x.init(tparams)
 	u.y = u.x // type parameters between LHS and RHS of unification are identical
 
@@ -393,7 +388,7 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	// Unify type parameters with their structural constraints, if any.
 	for _, tpar := range tparams {
-		typ := tpar.typ.(*_TypeParam)
+		typ := tpar.typ.(*TypeParam)
 		sbound := check.structuralType(typ.bound)
 		if sbound != nil {
 			if !u.unify(typ, sbound) {
@@ -407,8 +402,8 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 
 	// u.x.types() now contains the incoming type arguments plus any additional type
 	// arguments for which there were structural constraints. The newly inferred non-
-	// nil entries may still contain references to other type parameters. For instance,
-	// for [A any, B interface{type []C}, C interface{type *A}], if A == int
+	// nil entries may still contain references to other type parameters.
+	// For instance, for [A any, B interface{ []C }, C interface{ *A }], if A == int
 	// was given, unification produced the type list [int, []C, *A]. We eliminate the
 	// remaining type parameters by substituting the type parameters in this type list
 	// until nothing changes anymore.
@@ -471,12 +466,16 @@ func (check *Checker) inferB(tparams []*TypeName, targs []Type, report bool) (ty
 // structuralType returns the structural type of a constraint, if any.
 func (check *Checker) structuralType(constraint Type) Type {
 	if iface, _ := under(constraint).(*Interface); iface != nil {
-		check.completeInterface(token.NoPos, iface)
-		types := unpackType(iface.allTypes)
-		if len(types) == 1 {
-			return types[0]
+		types := iface.typeSet().types
+		if u, _ := types.(*Union); u != nil {
+			if u.NumTerms() == 1 {
+				// TODO(gri) do we need to respect tilde?
+				t, _ := u.Term(0)
+				return t
+			}
+			return nil
 		}
-		return nil
+		return types
 	}
-	return constraint
+	return nil
 }
diff --git a/src/go/types/instantiate.go b/src/go/types/instantiate.go
new file mode 100644
index 00000000000..6d56eb7ea21
--- /dev/null
+++ b/src/go/types/instantiate.go
@@ -0,0 +1,248 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements instantiation of generic types
+// through substitution of type parameters by type arguments.
+
+package types
+
+import (
+	"fmt"
+	"go/token"
+)
+
+// Instantiate instantiates the type typ with the given type arguments
+// targs. To check type constraint satisfaction, verify must be set.
+// pos and posList correspond to the instantiation and type argument
+// positions respectively; posList may be nil or shorter than the number
+// of type arguments provided.
+// typ must be a *Named or a *Signature type, and its number of type
+// parameters must match the number of provided type arguments.
+// The receiver (check) may be nil if and only if verify is not set.
+// The result is a new, instantiated (not generic) type of the same kind
+// (either a *Named or a *Signature).
+// Any methods attached to a *Named are simply copied; they are not
+// instantiated.
+func (check *Checker) Instantiate(pos token.Pos, typ Type, targs []Type, posList []token.Pos, verify bool) (res Type) {
+	var tparams []*TypeName
+	switch t := typ.(type) {
+	case *Named:
+		tparams = t.TParams().list()
+	case *Signature:
+		tparams = t.TParams().list()
+		defer func() {
+			// If we had an unexpected failure somewhere don't panic below when
+			// asserting res.(*Signature). Check for *Signature in case Typ[Invalid]
+			// is returned.
+			if _, ok := res.(*Signature); !ok {
+				return
+			}
+			// If the signature doesn't use its type parameters, subst
+			// will not make a copy. In that case, make a copy now (so
+			// we can set tparams to nil w/o causing side-effects).
+			if t == res {
+				copy := *t
+				res = ©
+			}
+			// After instantiating a generic signature, it is not generic
+			// anymore; we need to set tparams to nil.
+			res.(*Signature).tparams = nil
+		}()
+	default:
+		// only types and functions can be generic
+		panic(fmt.Sprintf("%v: cannot instantiate %v", pos, typ))
+	}
+
+	inst := check.instantiate(pos, typ, tparams, targs, posList)
+	if verify && len(tparams) == len(targs) {
+		check.verify(pos, tparams, targs, posList)
+	}
+	return inst
+}
+
+func (check *Checker) instantiate(pos token.Pos, typ Type, tparams []*TypeName, targs []Type, posList []token.Pos) (res Type) {
+	// the number of supplied types must match the number of type parameters
+	if len(targs) != len(tparams) {
+		// TODO(gri) provide better error message
+		if check != nil {
+			check.errorf(atPos(pos), _Todo, "got %d arguments but %d type parameters", len(targs), len(tparams))
+			return Typ[Invalid]
+		}
+		panic(fmt.Sprintf("%v: got %d arguments but %d type parameters", pos, len(targs), len(tparams)))
+	}
+
+	if check != nil && trace {
+		check.trace(pos, "-- instantiating %s with %s", typ, typeListString(targs))
+		check.indent++
+		defer func() {
+			check.indent--
+			var under Type
+			if res != nil {
+				// Calling under() here may lead to endless instantiations.
+				// Test case: type T[P any] T[P]
+				// TODO(gri) investigate if that's a bug or to be expected.
+				under = res.Underlying()
+			}
+			check.trace(pos, "=> %s (under = %s)", res, under)
+		}()
+	}
+
+	assert(len(posList) <= len(targs))
+
+	// TODO(gri) What is better here: work with TypeParams, or work with TypeNames?
+
+	if len(tparams) == 0 {
+		return typ // nothing to do (minor optimization)
+	}
+
+	smap := makeSubstMap(tparams, targs)
+
+	return check.subst(pos, typ, smap)
+}
+
+// InstantiateLazy is like Instantiate, but avoids actually
+// instantiating the type until needed. typ must be a *Named
+// type.
+func (check *Checker) InstantiateLazy(pos token.Pos, typ Type, targs []Type, posList []token.Pos, verify bool) Type {
+	// Don't use asNamed here: we don't want to expand the base during lazy
+	// instantiation.
+	base := typ.(*Named)
+	if base == nil {
+		panic(fmt.Sprintf("%v: cannot instantiate %v", pos, typ))
+	}
+	if verify && base.TParams().Len() == len(targs) {
+		check.later(func() {
+			check.verify(pos, base.tparams.list(), targs, posList)
+		})
+	}
+	h := instantiatedHash(base, targs)
+	if check != nil {
+		// typ may already have been instantiated with identical type arguments. In
+		// that case, re-use the existing instance.
+		if named := check.typMap[h]; named != nil {
+			return named
+		}
+	}
+
+	tname := NewTypeName(pos, base.obj.pkg, base.obj.name, nil)
+	named := check.newNamed(tname, base, nil, nil, nil) // methods and tparams are set when named is loaded.
+	named.targs = targs
+	named.instance = &instance{pos, posList}
+
+	if check != nil {
+		check.typMap[h] = named
+	}
+
+	return named
+}
+
+func (check *Checker) verify(pos token.Pos, tparams []*TypeName, targs []Type, posList []token.Pos) {
+	if check == nil {
+		panic("cannot have nil Checker if verifying constraints")
+	}
+
+	smap := makeSubstMap(tparams, targs)
+	for i, tname := range tparams {
+		// best position for error reporting
+		pos := pos
+		if i < len(posList) {
+			pos = posList[i]
+		}
+
+		// stop checking bounds after the first failure
+		if !check.satisfies(pos, targs[i], tname.typ.(*TypeParam), smap) {
+			break
+		}
+	}
+}
+
+// satisfies reports whether the type argument targ satisfies the constraint of type parameter
+// parameter tpar (after any of its type parameters have been substituted through smap).
+// A suitable error is reported if the result is false.
+// TODO(gri) This should be a method of interfaces or type sets.
+func (check *Checker) satisfies(pos token.Pos, targ Type, tpar *TypeParam, smap *substMap) bool {
+	iface := tpar.iface()
+	if iface.Empty() {
+		return true // no type bound
+	}
+
+	// The type parameter bound is parameterized with the same type parameters
+	// as the instantiated type; before we can use it for bounds checking we
+	// need to instantiate it with the type arguments with which we instantiate
+	// the parameterized type.
+	iface = check.subst(pos, iface, smap).(*Interface)
+
+	// if iface is comparable, targ must be comparable
+	// TODO(gri) the error messages needs to be better, here
+	if iface.IsComparable() && !Comparable(targ) {
+		if tpar := asTypeParam(targ); tpar != nil && tpar.iface().typeSet().IsTop() {
+			check.softErrorf(atPos(pos), _Todo, "%s has no constraints", targ)
+			return false
+		}
+		check.softErrorf(atPos(pos), _Todo, "%s does not satisfy comparable", targ)
+		return false
+	}
+
+	// targ must implement iface (methods)
+	// - check only if we have methods
+	if iface.NumMethods() > 0 {
+		// If the type argument is a pointer to a type parameter, the type argument's
+		// method set is empty.
+		// TODO(gri) is this what we want? (spec question)
+		if base, isPtr := deref(targ); isPtr && asTypeParam(base) != nil {
+			check.errorf(atPos(pos), 0, "%s has no methods", targ)
+			return false
+		}
+		if m, wrong := check.missingMethod(targ, iface, true); m != nil {
+			// TODO(gri) needs to print updated name to avoid major confusion in error message!
+			//           (print warning for now)
+			// Old warning:
+			// check.softErrorf(pos, "%s does not satisfy %s (warning: name not updated) = %s (missing method %s)", targ, tpar.bound, iface, m)
+			if wrong != nil {
+				// TODO(gri) This can still report uninstantiated types which makes the error message
+				//           more difficult to read then necessary.
+				// TODO(rFindley) should this use parentheses rather than ':' for qualification?
+				check.softErrorf(atPos(pos), _Todo,
+					"%s does not satisfy %s: wrong method signature\n\tgot  %s\n\twant %s",
+					targ, tpar.bound, wrong, m,
+				)
+			} else {
+				check.softErrorf(atPos(pos), 0, "%s does not satisfy %s (missing method %s)", targ, tpar.bound, m.name)
+			}
+			return false
+		}
+	}
+
+	// targ's underlying type must also be one of the interface types listed, if any
+	if iface.typeSet().types == nil {
+		return true // nothing to do
+	}
+
+	// If targ is itself a type parameter, each of its possible types, but at least one, must be in the
+	// list of iface types (i.e., the targ type list must be a non-empty subset of the iface types).
+	if targ := asTypeParam(targ); targ != nil {
+		targBound := targ.iface()
+		if targBound.typeSet().types == nil {
+			check.softErrorf(atPos(pos), _Todo, "%s does not satisfy %s (%s has no type constraints)", targ, tpar.bound, targ)
+			return false
+		}
+		return iface.is(func(typ Type, tilde bool) bool {
+			// TODO(gri) incorporate tilde information!
+			if !iface.isSatisfiedBy(typ) {
+				// TODO(gri) match this error message with the one below (or vice versa)
+				check.softErrorf(atPos(pos), 0, "%s does not satisfy %s (%s type constraint %s not found in %s)", targ, tpar.bound, targ, typ, iface.typeSet().types)
+				return false
+			}
+			return true
+		})
+	}
+
+	// Otherwise, targ's type or underlying type must also be one of the interface types listed, if any.
+	if !iface.isSatisfiedBy(targ) {
+		check.softErrorf(atPos(pos), _Todo, "%s does not satisfy %s (%s not found in %s)", targ, tpar.bound, targ, iface.typeSet().types)
+		return false
+	}
+
+	return true
+}
diff --git a/src/go/types/interface.go b/src/go/types/interface.go
new file mode 100644
index 00000000000..d8f96718571
--- /dev/null
+++ b/src/go/types/interface.go
@@ -0,0 +1,280 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"go/ast"
+	"go/internal/typeparams"
+	"go/token"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// An Interface represents an interface type.
+type Interface struct {
+	obj       *TypeName    // type name object defining this interface; or nil (for better error messages)
+	methods   []*Func      // ordered list of explicitly declared methods
+	embeddeds []Type       // ordered list of explicitly embedded elements
+	embedPos  *[]token.Pos // positions of embedded elements; or nil (for error messages) - use pointer to save space
+	complete  bool         // indicates that obj, methods, and embeddeds are set and type set can be computed
+
+	tset *_TypeSet // type set described by this interface, computed lazily
+}
+
+// typeSet returns the type set for interface t.
+func (t *Interface) typeSet() *_TypeSet { return computeTypeSet(nil, token.NoPos, t) }
+
+// is reports whether interface t represents types that all satisfy f.
+func (t *Interface) is(f func(Type, bool) bool) bool {
+	switch t := t.typeSet().types.(type) {
+	case nil, *top:
+		// TODO(gri) should settle on top or nil to represent this case
+		return false // we must have at least one type! (was bug)
+	case *Union:
+		return t.is(func(t *term) bool { return f(t.typ, t.tilde) })
+	default:
+		return f(t, false)
+	}
+}
+
+// emptyInterface represents the empty (completed) interface
+var emptyInterface = Interface{complete: true, tset: &topTypeSet}
+
+// NewInterface returns a new interface for the given methods and embedded types.
+// NewInterface takes ownership of the provided methods and may modify their types
+// by setting missing receivers.
+//
+// Deprecated: Use NewInterfaceType instead which allows arbitrary embedded types.
+func NewInterface(methods []*Func, embeddeds []*Named) *Interface {
+	tnames := make([]Type, len(embeddeds))
+	for i, t := range embeddeds {
+		tnames[i] = t
+	}
+	return NewInterfaceType(methods, tnames)
+}
+
+// NewInterfaceType returns a new interface for the given methods and embedded types.
+// NewInterfaceType takes ownership of the provided methods and may modify their types
+// by setting missing receivers.
+func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
+	if len(methods) == 0 && len(embeddeds) == 0 {
+		return &emptyInterface
+	}
+
+	// set method receivers if necessary
+	typ := new(Interface)
+	for _, m := range methods {
+		if sig := m.typ.(*Signature); sig.recv == nil {
+			sig.recv = NewVar(m.pos, m.pkg, "", typ)
+		}
+	}
+
+	// sort for API stability
+	sortMethods(methods)
+
+	typ.methods = methods
+	typ.embeddeds = embeddeds
+	typ.complete = true
+
+	return typ
+}
+
+// NumExplicitMethods returns the number of explicitly declared methods of interface t.
+func (t *Interface) NumExplicitMethods() int { return len(t.methods) }
+
+// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods().
+// The methods are ordered by their unique Id.
+func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] }
+
+// NumEmbeddeds returns the number of embedded types in interface t.
+func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) }
+
+// Embedded returns the i'th embedded defined (*Named) type of interface t for 0 <= i < t.NumEmbeddeds().
+// The result is nil if the i'th embedded type is not a defined type.
+//
+// Deprecated: Use EmbeddedType which is not restricted to defined (*Named) types.
+func (t *Interface) Embedded(i int) *Named { tname, _ := t.embeddeds[i].(*Named); return tname }
+
+// EmbeddedType returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds().
+func (t *Interface) EmbeddedType(i int) Type { return t.embeddeds[i] }
+
+// NumMethods returns the total number of methods of interface t.
+func (t *Interface) NumMethods() int { return t.typeSet().NumMethods() }
+
+// Method returns the i'th method of interface t for 0 <= i < t.NumMethods().
+// The methods are ordered by their unique Id.
+func (t *Interface) Method(i int) *Func { return t.typeSet().Method(i) }
+
+// Empty reports whether t is the empty interface.
+func (t *Interface) Empty() bool { return t.typeSet().IsTop() }
+
+// IsComparable reports whether each type in interface t's type set is comparable.
+func (t *Interface) IsComparable() bool { return t.typeSet().IsComparable() }
+
+// IsConstraint reports whether interface t is not just a method set.
+func (t *Interface) IsConstraint() bool { return !t.typeSet().IsMethodSet() }
+
+// isSatisfiedBy reports whether interface t's type list is satisfied by the type typ.
+// If the type list is empty (absent), typ trivially satisfies the interface.
+// TODO(gri) This is not a great name. Eventually, we should have a more comprehensive
+//           "implements" predicate.
+func (t *Interface) isSatisfiedBy(typ Type) bool {
+	t.Complete()
+	switch t := t.typeSet().types.(type) {
+	case nil:
+		return true // no type restrictions
+	case *Union:
+		r, _ := t.intersect(typ, false)
+		return r != nil
+	default:
+		return Identical(t, typ)
+	}
+}
+
+// Complete computes the interface's type set. It must be called by users of
+// NewInterfaceType and NewInterface after the interface's embedded types are
+// fully defined and before using the interface type in any way other than to
+// form other types. The interface must not contain duplicate methods or a
+// panic occurs. Complete returns the receiver.
+//
+// Deprecated: Type sets are now computed lazily, on demand; this function
+//             is only here for backward-compatibility. It does not have to
+//             be called explicitly anymore.
+func (t *Interface) Complete() *Interface {
+	// Some tests are still depending on the state change
+	// (string representation of an Interface not containing an
+	// /* incomplete */ marker) caused by the explicit Complete
+	// call, so we compute the type set eagerly here.
+	t.complete = true
+	t.typeSet()
+	return t
+}
+
+func (t *Interface) Underlying() Type { return t }
+func (t *Interface) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, def *Named) {
+	var tlist []ast.Expr
+	var tname *ast.Ident // "type" name of first entry in a type list declaration
+
+	addEmbedded := func(pos token.Pos, typ Type) {
+		ityp.embeddeds = append(ityp.embeddeds, typ)
+		if ityp.embedPos == nil {
+			ityp.embedPos = new([]token.Pos)
+		}
+		*ityp.embedPos = append(*ityp.embedPos, pos)
+	}
+
+	for _, f := range iface.Methods.List {
+		if len(f.Names) == 0 {
+			// We have an embedded type; possibly a union of types.
+			addEmbedded(f.Type.Pos(), parseUnion(check, flattenUnion(nil, f.Type)))
+			continue
+		}
+
+		// We have a method with name f.Names[0], or a type
+		// of a type list (name.Name == "type").
+		// (The parser ensures that there's only one method
+		// and we don't care if a constructed AST has more.)
+		name := f.Names[0]
+		if name.Name == "_" {
+			check.errorf(name, _BlankIfaceMethod, "invalid method name _")
+			continue // ignore
+		}
+
+		// TODO(rfindley) Remove type list handling once the parser doesn't accept type lists anymore.
+		if name.Name == "type" {
+			// Report an error for the first type list per interface
+			// if we don't allow type lists, but continue.
+			if !allowTypeLists && tlist == nil {
+				check.softErrorf(name, _Todo, "use generalized embedding syntax instead of a type list")
+			}
+			// For now, collect all type list entries as if it
+			// were a single union, where each union element is
+			// of the form ~T.
+			// TODO(rfindley) remove once we disallow type lists
+			op := new(ast.UnaryExpr)
+			op.Op = token.TILDE
+			op.X = f.Type
+			tlist = append(tlist, op)
+			// Report an error if we have multiple type lists in an
+			// interface, but only if they are permitted in the first place.
+			if allowTypeLists && tname != nil && tname != name {
+				check.errorf(name, _Todo, "cannot have multiple type lists in an interface")
+			}
+			tname = name
+			continue
+		}
+
+		typ := check.typ(f.Type)
+		sig, _ := typ.(*Signature)
+		if sig == nil {
+			if typ != Typ[Invalid] {
+				check.invalidAST(f.Type, "%s is not a method signature", typ)
+			}
+			continue // ignore
+		}
+
+		// Always type-check method type parameters but complain if they are not enabled.
+		// (This extra check is needed here because interface method signatures don't have
+		// a receiver specification.)
+		if sig.tparams != nil {
+			var at positioner = f.Type
+			if tparams := typeparams.Get(f.Type); tparams != nil {
+				at = tparams
+			}
+			check.errorf(at, _Todo, "methods cannot have type parameters")
+		}
+
+		// use named receiver type if available (for better error messages)
+		var recvTyp Type = ityp
+		if def != nil {
+			recvTyp = def
+		}
+		sig.recv = NewVar(name.Pos(), check.pkg, "", recvTyp)
+
+		m := NewFunc(name.Pos(), check.pkg, name.Name, sig)
+		check.recordDef(name, m)
+		ityp.methods = append(ityp.methods, m)
+	}
+
+	// type constraints
+	if tlist != nil {
+		// TODO(rfindley): this differs from types2 due to the use of Pos() below,
+		// which should actually be on the ~. Confirm that this position is correct.
+		addEmbedded(tlist[0].Pos(), parseUnion(check, tlist))
+	}
+
+	// All methods and embedded elements for this interface are collected;
+	// i.e., this interface is may be used in a type set computation.
+	ityp.complete = true
+
+	if len(ityp.methods) == 0 && len(ityp.embeddeds) == 0 {
+		// empty interface
+		ityp.tset = &topTypeSet
+		return
+	}
+
+	// sort for API stability
+	sortMethods(ityp.methods)
+	// (don't sort embeddeds: they must correspond to *embedPos entries)
+
+	// Compute type set with a non-nil *Checker as soon as possible
+	// to report any errors. Subsequent uses of type sets will use
+	// this computed type set and won't need to pass in a *Checker.
+	check.later(func() { computeTypeSet(check, iface.Pos(), ityp) })
+}
+
+func flattenUnion(list []ast.Expr, x ast.Expr) []ast.Expr {
+	if o, _ := x.(*ast.BinaryExpr); o != nil && o.Op == token.OR {
+		list = flattenUnion(list, o.X)
+		x = o.Y
+	}
+	return append(list, x)
+}
diff --git a/src/go/types/issues_test.go b/src/go/types/issues_test.go
index 44926919efe..51995af30af 100644
--- a/src/go/types/issues_test.go
+++ b/src/go/types/issues_test.go
@@ -577,42 +577,64 @@ func TestIssue44515(t *testing.T) {
 }
 
 func TestIssue43124(t *testing.T) {
-	// TODO(rFindley) enhance the testdata tests to be able to express this type
-	//                of setup.
+	// TODO(rFindley) move this to testdata by enhancing support for importing.
 
 	// All involved packages have the same name (template). Error messages should
 	// disambiguate between text/template and html/template by printing the full
 	// path.
 	const (
 		asrc = `package a; import "text/template"; func F(template.Template) {}; func G(int) {}`
-		bsrc = `package b; import ("a"; "html/template"); func _() { a.F(template.Template{}) }`
-		csrc = `package c; import ("a"; "html/template"); func _() { a.G(template.Template{}) }`
+		bsrc = `
+package b
+
+import (
+	"a"
+	"html/template"
+)
+
+func _() {
+	// Packages should be fully qualified when there is ambiguity within the
+	// error string itself.
+	a.F(template /* ERROR cannot use.*html/template.* as .*text/template */ .Template{})
+}
+`
+		csrc = `
+package c
+
+import (
+	"a"
+	"fmt"
+	"html/template"
+)
+
+// Issue #46905: make sure template is not the first package qualified.
+var _ fmt.Stringer = 1 // ERROR cannot use 1.*as fmt\.Stringer
+
+// Packages should be fully qualified when there is ambiguity in reachable
+// packages. In this case both a (and for that matter html/template) import
+// text/template.
+func _() { a.G(template /* ERROR cannot use .*html/template.*Template */ .Template{}) }
+`
+
+		tsrc = `
+package template
+
+import "text/template"
+
+type T int
+
+// Verify that the current package name also causes disambiguation.
+var _ T = template /* ERROR cannot use.*text/template.* as T value */.Template{}
+`
 	)
 
 	a, err := pkgFor("a", asrc, nil)
 	if err != nil {
 		t.Fatalf("package a failed to typecheck: %v", err)
 	}
-	conf := Config{Importer: importHelper{pkg: a, fallback: importer.Default()}}
+	imp := importHelper{pkg: a, fallback: importer.Default()}
 
-	// Packages should be fully qualified when there is ambiguity within the
-	// error string itself.
-	bast := mustParse(t, bsrc)
-	_, err = conf.Check(bast.Name.Name, fset, []*ast.File{bast}, nil)
-	if err == nil {
-		t.Fatal("package b had no errors")
-	}
-	if !strings.Contains(err.Error(), "text/template") || !strings.Contains(err.Error(), "html/template") {
-		t.Errorf("type checking error for b does not disambiguate package template: %q", err)
-	}
-
-	// ...and also when there is any ambiguity in reachable packages.
-	cast := mustParse(t, csrc)
-	_, err = conf.Check(cast.Name.Name, fset, []*ast.File{cast}, nil)
-	if err == nil {
-		t.Fatal("package c had no errors")
-	}
-	if !strings.Contains(err.Error(), "html/template") {
-		t.Errorf("type checking error for c does not disambiguate package template: %q", err)
-	}
+	testFiles(t, nil, []string{"b.go"}, [][]byte{[]byte(bsrc)}, false, imp)
+	testFiles(t, nil, []string{"c.go"}, [][]byte{[]byte(csrc)}, false, imp)
+	testFiles(t, nil, []string{"t.go"}, [][]byte{[]byte(tsrc)}, false, imp)
 }
diff --git a/src/go/types/labels.go b/src/go/types/labels.go
index 8cf6e63645e..f3b7f211f37 100644
--- a/src/go/types/labels.go
+++ b/src/go/types/labels.go
@@ -36,7 +36,8 @@ func (check *Checker) labels(body *ast.BlockStmt) {
 	}
 
 	// spec: "It is illegal to define a label that is never used."
-	for _, obj := range all.elems {
+	for name, obj := range all.elems {
+		obj = resolve(name, obj)
 		if lbl := obj.(*Label); !lbl.used {
 			check.softErrorf(lbl, _UnusedLabel, "label %s declared but not used", lbl.name)
 		}
diff --git a/src/go/types/lookup.go b/src/go/types/lookup.go
index 9c7bfd4bb97..7cab336dbe2 100644
--- a/src/go/types/lookup.go
+++ b/src/go/types/lookup.go
@@ -8,6 +8,11 @@ package types
 
 import "go/token"
 
+// Internal use of LookupFieldOrMethod: If the obj result is a method
+// associated with a concrete (non-interface) type, the method's signature
+// may not be fully set up. Call Checker.objDecl(obj, nil) before accessing
+// the method's type.
+
 // LookupFieldOrMethod looks up a field or method with given package and name
 // in T and returns the corresponding *Var or *Func, an index sequence, and a
 // bool indicating if there were any pointer indirections on the path to the
@@ -35,19 +40,6 @@ import "go/token"
 //	the method's formal receiver base type, nor was the receiver addressable.
 //
 func LookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
-	return (*Checker)(nil).lookupFieldOrMethod(T, addressable, pkg, name)
-}
-
-// Internal use of Checker.lookupFieldOrMethod: If the obj result is a method
-// associated with a concrete (non-interface) type, the method's signature
-// may not be fully set up. Call Checker.objDecl(obj, nil) before accessing
-// the method's type.
-// TODO(gri) Now that we provide the *Checker, we can probably remove this
-// caveat by calling Checker.objDecl from lookupFieldOrMethod. Investigate.
-
-// lookupFieldOrMethod is like the external version but completes interfaces
-// as necessary.
-func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
 	// Methods cannot be associated to a named pointer type
 	// (spec: "The type denoted by T is called the receiver base type;
 	// it must not be a pointer or interface type and it must be declared
@@ -56,8 +48,8 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 	// pointer type but discard the result if it is a method since we would
 	// not have found it for T (see also issue 8590).
 	if t := asNamed(T); t != nil {
-		if p, _ := t.underlying.(*Pointer); p != nil {
-			obj, index, indirect = check.rawLookupFieldOrMethod(p, false, pkg, name)
+		if p, _ := t.Underlying().(*Pointer); p != nil {
+			obj, index, indirect = lookupFieldOrMethod(p, false, pkg, name)
 			if _, ok := obj.(*Func); ok {
 				return nil, nil, false
 			}
@@ -65,7 +57,7 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 		}
 	}
 
-	return check.rawLookupFieldOrMethod(T, addressable, pkg, name)
+	return lookupFieldOrMethod(T, addressable, pkg, name)
 }
 
 // TODO(gri) The named type consolidation and seen maps below must be
@@ -73,10 +65,9 @@ func (check *Checker) lookupFieldOrMethod(T Type, addressable bool, pkg *Package
 //           types always have only one representation (even when imported
 //           indirectly via different packages.)
 
-// rawLookupFieldOrMethod should only be called by lookupFieldOrMethod and missingMethod.
-func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
+// lookupFieldOrMethod should only be called by LookupFieldOrMethod and missingMethod.
+func lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) {
 	// WARNING: The code in this function is extremely subtle - do not modify casually!
-	//          This function and NewMethodSet should be kept in sync.
 
 	if name == "_" {
 		return // blank fields/methods are never found
@@ -84,10 +75,12 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 
 	typ, isPtr := deref(T)
 
-	// *typ where typ is an interface has no methods.
-	// Be cautious: typ may be nil (issue 39634, crash #3).
-	if typ == nil || isPtr && IsInterface(typ) {
-		return
+	// *typ where typ is an interface or type parameter has no methods.
+	switch under(typ).(type) {
+	case *Interface, *TypeParam:
+		if isPtr {
+			return
+		}
 	}
 
 	// Start with typ as single entry at shallowest depth.
@@ -107,7 +100,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 		var next []embeddedType // embedded types found at current depth
 
 		// look for (pkg, name) in all types at current depth
-		var tpar *_TypeParam // set if obj receiver is a type parameter
+		var tpar *TypeParam // set if obj receiver is a type parameter
 		for _, e := range current {
 			typ := e.typ
 
@@ -128,6 +121,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 				seen[named] = true
 
 				// look for a matching attached method
+				named.load()
 				if i, m := lookupMethod(named.methods, pkg, name); m != nil {
 					// potential match
 					// caution: method may not have a proper signature yet
@@ -185,9 +179,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 
 			case *Interface:
 				// look for a matching method
-				// TODO(gri) t.allMethods is sorted - use binary search
-				check.completeInterface(token.NoPos, t)
-				if i, m := lookupMethod(t.allMethods, pkg, name); m != nil {
+				if i, m := t.typeSet().LookupMethod(pkg, name); m != nil {
 					assert(m.typ != nil)
 					index = concat(e.index, i)
 					if obj != nil || e.multiples {
@@ -197,10 +189,8 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 					indirect = e.indirect
 				}
 
-			case *_TypeParam:
-				// only consider explicit methods in the type parameter bound, not
-				// methods that may be common to all types in the type list.
-				if i, m := lookupMethod(t.Bound().allMethods, pkg, name); m != nil {
+			case *TypeParam:
+				if i, m := t.iface().typeSet().LookupMethod(pkg, name); m != nil {
 					assert(m.typ != nil)
 					index = concat(e.index, i)
 					if obj != nil || e.multiples {
@@ -229,7 +219,7 @@ func (check *Checker) rawLookupFieldOrMethod(T Type, addressable bool, pkg *Pack
 			return
 		}
 
-		current = check.consolidateMultiples(next)
+		current = consolidateMultiples(next)
 	}
 
 	return nil, nil, false // not found
@@ -246,7 +236,7 @@ type embeddedType struct {
 // consolidateMultiples collects multiple list entries with the same type
 // into a single entry marked as containing multiples. The result is the
 // consolidated list.
-func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
+func consolidateMultiples(list []embeddedType) []embeddedType {
 	if len(list) <= 1 {
 		return list // at most one entry - nothing to do
 	}
@@ -254,7 +244,7 @@ func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
 	n := 0                     // number of entries w/ unique type
 	prev := make(map[Type]int) // index at which type was previously seen
 	for _, e := range list {
-		if i, found := check.lookupType(prev, e.typ); found {
+		if i, found := lookupType(prev, e.typ); found {
 			list[i].multiples = true
 			// ignore this entry
 		} else {
@@ -266,14 +256,14 @@ func (check *Checker) consolidateMultiples(list []embeddedType) []embeddedType {
 	return list[:n]
 }
 
-func (check *Checker) lookupType(m map[Type]int, typ Type) (int, bool) {
+func lookupType(m map[Type]int, typ Type) (int, bool) {
 	// fast path: maybe the types are equal
 	if i, found := m[typ]; found {
 		return i, true
 	}
 
 	for t, i := range m {
-		if check.identical(t, typ) {
+		if Identical(t, typ) {
 			return i, true
 		}
 	}
@@ -306,40 +296,40 @@ func MissingMethod(V Type, T *Interface, static bool) (method *Func, wrongType b
 // To improve error messages, also report the wrong signature
 // when the method exists on *V instead of V.
 func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method, wrongType *Func) {
-	check.completeInterface(token.NoPos, T)
-
 	// fast path for common case
 	if T.Empty() {
 		return
 	}
 
 	if ityp := asInterface(V); ityp != nil {
-		check.completeInterface(token.NoPos, ityp)
-		// TODO(gri) allMethods is sorted - can do this more efficiently
-		for _, m := range T.allMethods {
-			_, f := lookupMethod(ityp.allMethods, m.pkg, m.name)
+		// TODO(gri) the methods are sorted - could do this more efficiently
+		for _, m := range T.typeSet().methods {
+			_, f := ityp.typeSet().LookupMethod(m.pkg, m.name)
 
 			if f == nil {
-				// if m is the magic method == we're ok (interfaces are comparable)
-				if m.name == "==" || !static {
+				if !static {
 					continue
 				}
 				return m, f
 			}
 
+			// both methods must have the same number of type parameters
 			ftyp := f.typ.(*Signature)
 			mtyp := m.typ.(*Signature)
-			if len(ftyp.tparams) != len(mtyp.tparams) {
+			if ftyp.TParams().Len() != mtyp.TParams().Len() {
 				return m, f
 			}
+			if ftyp.TParams().Len() > 0 {
+				panic("internal error: method with type parameters")
+			}
 
 			// If the methods have type parameters we don't care whether they
 			// are the same or not, as long as they match up. Use unification
 			// to see if they can be made to match.
 			// TODO(gri) is this always correct? what about type bounds?
 			// (Alternative is to rename/subst type parameters and compare.)
-			u := newUnifier(check, true)
-			u.x.init(ftyp.tparams)
+			u := newUnifier(true)
+			u.x.init(ftyp.TParams().list())
 			if !u.unify(ftyp, mtyp) {
 				return m, f
 			}
@@ -351,14 +341,14 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 	// A concrete type implements T if it implements all methods of T.
 	Vd, _ := deref(V)
 	Vn := asNamed(Vd)
-	for _, m := range T.allMethods {
+	for _, m := range T.typeSet().methods {
 		// TODO(gri) should this be calling lookupFieldOrMethod instead (and why not)?
-		obj, _, _ := check.rawLookupFieldOrMethod(V, false, m.pkg, m.name)
+		obj, _, _ := lookupFieldOrMethod(V, false, m.pkg, m.name)
 
 		// Check if *V implements this method of T.
 		if obj == nil {
 			ptr := NewPointer(V)
-			obj, _, _ = check.rawLookupFieldOrMethod(ptr, false, m.pkg, m.name)
+			obj, _, _ = lookupFieldOrMethod(ptr, false, m.pkg, m.name)
 			if obj != nil {
 				return m, obj.(*Func)
 			}
@@ -367,10 +357,6 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// we must have a method (not a field of matching function type)
 		f, _ := obj.(*Func)
 		if f == nil {
-			// if m is the magic method == and V is comparable, we're ok
-			if m.name == "==" && Comparable(V) {
-				continue
-			}
 			return m, nil
 		}
 
@@ -382,9 +368,12 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// both methods must have the same number of type parameters
 		ftyp := f.typ.(*Signature)
 		mtyp := m.typ.(*Signature)
-		if len(ftyp.tparams) != len(mtyp.tparams) {
+		if ftyp.TParams().Len() != mtyp.TParams().Len() {
 			return m, f
 		}
+		if ftyp.TParams().Len() > 0 {
+			panic("internal error: method with type parameters")
+		}
 
 		// If V is a (instantiated) generic type, its methods are still
 		// parameterized using the original (declaration) receiver type
@@ -393,17 +382,17 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// In order to compare the signatures, substitute the receiver
 		// type parameters of ftyp with V's instantiation type arguments.
 		// This lazily instantiates the signature of method f.
-		if Vn != nil && len(Vn.tparams) > 0 {
+		if Vn != nil && Vn.TParams().Len() > 0 {
 			// Be careful: The number of type arguments may not match
 			// the number of receiver parameters. If so, an error was
 			// reported earlier but the length discrepancy is still
 			// here. Exit early in this case to prevent an assertion
 			// failure in makeSubstMap.
 			// TODO(gri) Can we avoid this check by fixing the lengths?
-			if len(ftyp.rparams) != len(Vn.targs) {
+			if len(ftyp.RParams().list()) != len(Vn.targs) {
 				return
 			}
-			ftyp = check.subst(token.NoPos, ftyp, makeSubstMap(ftyp.rparams, Vn.targs)).(*Signature)
+			ftyp = check.subst(token.NoPos, ftyp, makeSubstMap(ftyp.RParams().list(), Vn.targs)).(*Signature)
 		}
 
 		// If the methods have type parameters we don't care whether they
@@ -411,8 +400,8 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
 		// to see if they can be made to match.
 		// TODO(gri) is this always correct? what about type bounds?
 		// (Alternative is to rename/subst type parameters and compare.)
-		u := newUnifier(check, true)
-		u.x.init(ftyp.tparams)
+		u := newUnifier(true)
+		u.x.init(ftyp.RParams().list())
 		if !u.unify(ftyp, mtyp) {
 			return m, f
 		}
diff --git a/src/go/types/map.go b/src/go/types/map.go
new file mode 100644
index 00000000000..01e13b214e9
--- /dev/null
+++ b/src/go/types/map.go
@@ -0,0 +1,24 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// A Map represents a map type.
+type Map struct {
+	key, elem Type
+}
+
+// NewMap returns a new map for the given key and element types.
+func NewMap(key, elem Type) *Map {
+	return &Map{key: key, elem: elem}
+}
+
+// Key returns the key type of map m.
+func (m *Map) Key() Type { return m.key }
+
+// Elem returns the element type of map m.
+func (m *Map) Elem() Type { return m.elem }
+
+func (t *Map) Underlying() Type { return t }
+func (t *Map) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/methodset.go b/src/go/types/methodset.go
index ae8011a2eee..1462601d586 100644
--- a/src/go/types/methodset.go
+++ b/src/go/types/methodset.go
@@ -130,7 +130,7 @@ func NewMethodSet(T Type) *MethodSet {
 				// continue with underlying type, but only if it's not a type parameter
 				// TODO(rFindley): should this use named.under()? Can there be a difference?
 				typ = named.underlying
-				if _, ok := typ.(*_TypeParam); ok {
+				if _, ok := typ.(*TypeParam); ok {
 					continue
 				}
 			}
@@ -157,10 +157,10 @@ func NewMethodSet(T Type) *MethodSet {
 				}
 
 			case *Interface:
-				mset = mset.add(t.allMethods, e.index, true, e.multiples)
+				mset = mset.add(t.typeSet().methods, e.index, true, e.multiples)
 
-			case *_TypeParam:
-				mset = mset.add(t.Bound().allMethods, e.index, true, e.multiples)
+			case *TypeParam:
+				mset = mset.add(t.iface().typeSet().methods, e.index, true, e.multiples)
 			}
 		}
 
@@ -190,12 +190,7 @@ func NewMethodSet(T Type) *MethodSet {
 			}
 		}
 
-		// It's ok to call consolidateMultiples with a nil *Checker because
-		// MethodSets are not used internally (outside debug mode). When used
-		// externally, interfaces are expected to be completed and then we do
-		// not need a *Checker to complete them when (indirectly) calling
-		// Checker.identical via consolidateMultiples.
-		current = (*Checker)(nil).consolidateMultiples(next)
+		current = consolidateMultiples(next)
 	}
 
 	if len(base) == 0 {
diff --git a/src/go/types/methodset_test.go b/src/go/types/methodset_test.go
index 4a373fa2c4f..73a8442f214 100644
--- a/src/go/types/methodset_test.go
+++ b/src/go/types/methodset_test.go
@@ -7,7 +7,6 @@ package types_test
 import (
 	"testing"
 
-	"go/internal/typeparams"
 	. "go/types"
 )
 
@@ -47,12 +46,15 @@ func TestNewMethodSet(t *testing.T) {
 
 	genericTests := map[string][]method{
 		// By convention, look up a in the scope of "g"
-		"type C interface{ f() }; func g[T C](a T){}":                       {{"f", []int{0}, true}},
-		"type C interface{ f() }; func g[T C]() { var a T; _ = a }":         {{"f", []int{0}, true}},
-		"type C interface{ f() }; func g[T C]() { var a struct{T}; _ = a }": {{"f", []int{0, 0}, true}},
+		"type C interface{ f() }; func g[T C](a T){}":               {{"f", []int{0}, true}},
+		"type C interface{ f() }; func g[T C]() { var a T; _ = a }": {{"f", []int{0}, true}},
 
-		// Issue #45639.
-		"type C interface{ f() }; func g[T C]() { type Y T; var a Y; _ = a }": {},
+		// Issue #43621: We don't allow this anymore. Keep this code in case we
+		// decide to revisit this decision.
+		// "type C interface{ f() }; func g[T C]() { var a struct{T}; _ = a }": {{"f", []int{0, 0}, true}},
+
+		// Issue #45639: We also don't allow this anymore.
+		// "type C interface{ f() }; func g[T C]() { type Y T; var a Y; _ = a }": {},
 	}
 
 	check := func(src string, methods []method, generic bool) {
@@ -101,9 +103,7 @@ func TestNewMethodSet(t *testing.T) {
 		check(src, methods, false)
 	}
 
-	if typeparams.Enabled {
-		for src, methods := range genericTests {
-			check(src, methods, true)
-		}
+	for src, methods := range genericTests {
+		check(src, methods, true)
 	}
 }
diff --git a/src/go/types/named.go b/src/go/types/named.go
new file mode 100644
index 00000000000..f26b50aa811
--- /dev/null
+++ b/src/go/types/named.go
@@ -0,0 +1,296 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"go/token"
+	"sync"
+)
+
+// TODO(rfindley) Clean up Named struct below; specifically the fromRHS field (can we use underlying?).
+
+// A Named represents a named (defined) type.
+type Named struct {
+	check      *Checker
+	info       typeInfo    // for cycle detection
+	obj        *TypeName   // corresponding declared object
+	orig       *Named      // original, uninstantiated type
+	fromRHS    Type        // type (on RHS of declaration) this *Named type is derived of (for cycle reporting)
+	underlying Type        // possibly a *Named during setup; never a *Named once set up completely
+	instance   *instance   // syntactic information for lazy instantiation
+	tparams    *TypeParams // type parameters, or nil
+	targs      []Type      // type arguments (after instantiation), or nil
+	methods    []*Func     // methods declared for this type (not the method set of this type); signatures are type-checked lazily
+
+	resolve func(*Named) ([]*TypeName, Type, []*Func)
+	once    sync.Once
+}
+
+// NewNamed returns a new named type for the given type name, underlying type, and associated methods.
+// If the given type name obj doesn't have a type yet, its type is set to the returned named type.
+// The underlying type must not be a *Named.
+func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
+	if _, ok := underlying.(*Named); ok {
+		panic("types.NewNamed: underlying type must not be *Named")
+	}
+	return (*Checker)(nil).newNamed(obj, nil, underlying, nil, methods)
+}
+
+func (t *Named) load() *Named {
+	// If t is an instantiated type, it derives its methods and tparams from its
+	// base type. Since we expect type parameters and methods to be set after a
+	// call to load, we must load the base and copy here.
+	//
+	// underlying is set when t is expanded.
+	//
+	// By convention, a type instance is loaded iff its tparams are set.
+	if len(t.targs) > 0 && t.tparams == nil {
+		t.orig.load()
+		t.tparams = t.orig.tparams
+		t.methods = t.orig.methods
+	}
+	if t.resolve == nil {
+		return t
+	}
+
+	t.once.Do(func() {
+		// TODO(mdempsky): Since we're passing t to resolve anyway
+		// (necessary because types2 expects the receiver type for methods
+		// on defined interface types to be the Named rather than the
+		// underlying Interface), maybe it should just handle calling
+		// SetTParams, SetUnderlying, and AddMethod instead?  Those
+		// methods would need to support reentrant calls though.  It would
+		// also make the API more future-proof towards further extensions
+		// (like SetTParams).
+
+		tparams, underlying, methods := t.resolve(t)
+
+		switch underlying.(type) {
+		case nil, *Named:
+			panic("invalid underlying type")
+		}
+
+		t.tparams = bindTParams(tparams)
+		t.underlying = underlying
+		t.methods = methods
+	})
+	return t
+}
+
+// newNamed is like NewNamed but with a *Checker receiver and additional orig argument.
+func (check *Checker) newNamed(obj *TypeName, orig *Named, underlying Type, tparams *TypeParams, methods []*Func) *Named {
+	typ := &Named{check: check, obj: obj, orig: orig, fromRHS: underlying, underlying: underlying, tparams: tparams, methods: methods}
+	if typ.orig == nil {
+		typ.orig = typ
+	}
+	if obj.typ == nil {
+		obj.typ = typ
+	}
+	// Ensure that typ is always expanded, at which point the check field can be
+	// nilled out.
+	//
+	// Note that currently we cannot nil out check inside typ.under(), because
+	// it's possible that typ is expanded multiple times.
+	//
+	// TODO(rFindley): clean this up so that under is the only function mutating
+	//                 named types.
+	if check != nil {
+		check.later(func() {
+			switch typ.under().(type) {
+			case *Named:
+				panic("internal error: unexpanded underlying type")
+			}
+			typ.check = nil
+		})
+	}
+	return typ
+}
+
+// Obj returns the type name for the named type t.
+func (t *Named) Obj() *TypeName { return t.obj }
+
+// _Orig returns the original generic type an instantiated type is derived from.
+// If t is not an instantiated type, the result is t.
+func (t *Named) _Orig() *Named { return t.orig }
+
+// TODO(gri) Come up with a better representation and API to distinguish
+//           between parameterized instantiated and non-instantiated types.
+
+// TParams returns the type parameters of the named type t, or nil.
+// The result is non-nil for an (originally) parameterized type even if it is instantiated.
+func (t *Named) TParams() *TypeParams { return t.load().tparams }
+
+// SetTParams sets the type parameters of the named type t.
+func (t *Named) SetTParams(tparams []*TypeName) { t.load().tparams = bindTParams(tparams) }
+
+// NumTArgs returns the number of type arguments used to instantiate the named
+// type t, or 0 if t is not an instantiated type.
+func (t *Named) NumTArgs() int { return len(t.targs) }
+
+// TArgs returns the i'th type argument of the named type t for 0 <= i < t.NumTArgs().
+func (t *Named) TArg(i int) Type { return t.targs[i] }
+
+// SetTArgs sets the type arguments of the named type t.
+func (t *Named) SetTArgs(args []Type) { t.targs = args }
+
+// NumMethods returns the number of explicit methods whose receiver is named type t.
+func (t *Named) NumMethods() int { return len(t.load().methods) }
+
+// Method returns the i'th method of named type t for 0 <= i < t.NumMethods().
+func (t *Named) Method(i int) *Func { return t.load().methods[i] }
+
+// SetUnderlying sets the underlying type and marks t as complete.
+func (t *Named) SetUnderlying(underlying Type) {
+	if underlying == nil {
+		panic("types.Named.SetUnderlying: underlying type must not be nil")
+	}
+	if _, ok := underlying.(*Named); ok {
+		panic("types.Named.SetUnderlying: underlying type must not be *Named")
+	}
+	t.load().underlying = underlying
+}
+
+// AddMethod adds method m unless it is already in the method list.
+func (t *Named) AddMethod(m *Func) {
+	t.load()
+	if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 {
+		t.methods = append(t.methods, m)
+	}
+}
+
+func (t *Named) Underlying() Type { return t.load().underlying }
+func (t *Named) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// under returns the expanded underlying type of n0; possibly by following
+// forward chains of named types. If an underlying type is found, resolve
+// the chain by setting the underlying type for each defined type in the
+// chain before returning it. If no underlying type is found or a cycle
+// is detected, the result is Typ[Invalid]. If a cycle is detected and
+// n0.check != nil, the cycle is reported.
+func (n0 *Named) under() Type {
+	n0.expand()
+
+	u := n0.Underlying()
+
+	if u == Typ[Invalid] {
+		return u
+	}
+
+	// If the underlying type of a defined type is not a defined
+	// (incl. instance) type, then that is the desired underlying
+	// type.
+	switch u.(type) {
+	case nil:
+		return Typ[Invalid]
+	default:
+		// common case
+		return u
+	case *Named:
+		// handled below
+	}
+
+	if n0.check == nil {
+		panic("internal error: Named.check == nil but type is incomplete")
+	}
+
+	// Invariant: after this point n0 as well as any named types in its
+	// underlying chain should be set up when this function exits.
+	check := n0.check
+
+	// If we can't expand u at this point, it is invalid.
+	n := asNamed(u)
+	if n == nil {
+		n0.underlying = Typ[Invalid]
+		return n0.underlying
+	}
+
+	// Otherwise, follow the forward chain.
+	seen := map[*Named]int{n0: 0}
+	path := []Object{n0.obj}
+	for {
+		u = n.Underlying()
+		if u == nil {
+			u = Typ[Invalid]
+			break
+		}
+		var n1 *Named
+		switch u1 := u.(type) {
+		case *Named:
+			u1.expand()
+			n1 = u1
+		}
+		if n1 == nil {
+			break // end of chain
+		}
+
+		seen[n] = len(seen)
+		path = append(path, n.obj)
+		n = n1
+
+		if i, ok := seen[n]; ok {
+			// cycle
+			check.cycleError(path[i:])
+			u = Typ[Invalid]
+			break
+		}
+	}
+
+	for n := range seen {
+		// We should never have to update the underlying type of an imported type;
+		// those underlying types should have been resolved during the import.
+		// Also, doing so would lead to a race condition (was issue #31749).
+		// Do this check always, not just in debug mode (it's cheap).
+		if n.obj.pkg != check.pkg {
+			panic("internal error: imported type with unresolved underlying type")
+		}
+		n.underlying = u
+	}
+
+	return u
+}
+
+func (n *Named) setUnderlying(typ Type) {
+	if n != nil {
+		n.underlying = typ
+	}
+}
+
+// instance holds position information for use in lazy instantiation.
+//
+// TODO(rfindley): come up with a better name for this type, now that its usage
+// has changed.
+type instance struct {
+	pos     token.Pos   // position of type instantiation; for error reporting only
+	posList []token.Pos // position of each targ; for error reporting only
+}
+
+// expand ensures that the underlying type of n is instantiated.
+// The underlying type will be Typ[Invalid] if there was an error.
+// TODO(rfindley): expand would be a better name for this method, but conflicts
+// with the existing concept of lazy expansion. Need to reconcile this.
+func (n *Named) expand() {
+	if n.instance != nil {
+		// n must be loaded before instantiation, in order to have accurate
+		// tparams. This is done implicitly by the call to n.TParams, but making it
+		// explicit is harmless: load is idempotent.
+		n.load()
+		inst := n.check.instantiate(n.instance.pos, n.orig.underlying, n.TParams().list(), n.targs, n.instance.posList)
+		n.underlying = inst
+		n.fromRHS = inst
+		n.instance = nil
+	}
+}
+
+// expand expands uninstantiated named types and leaves all other types alone.
+// expand does not recurse.
+func expand(typ Type) Type {
+	if t, _ := typ.(*Named); t != nil {
+		t.expand()
+	}
+	return typ
+}
diff --git a/src/go/types/object.go b/src/go/types/object.go
index 50346ec6919..7266623fbe9 100644
--- a/src/go/types/object.go
+++ b/src/go/types/object.go
@@ -230,6 +230,14 @@ func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeName {
 	return &TypeName{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}}
 }
 
+// _NewTypeNameLazy returns a new defined type like NewTypeName, but it
+// lazily calls resolve to finish constructing the Named object.
+func _NewTypeNameLazy(pos token.Pos, pkg *Package, name string, resolve func(named *Named) (tparams []*TypeName, underlying Type, methods []*Func)) *TypeName {
+	obj := NewTypeName(pos, pkg, name, nil)
+	NewNamed(obj, nil, nil).resolve = resolve
+	return obj
+}
+
 // IsAlias reports whether obj is an alias name for a type.
 func (obj *TypeName) IsAlias() bool {
 	switch t := obj.typ.(type) {
@@ -421,6 +429,9 @@ func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) {
 		if _, ok := typ.(*Basic); ok {
 			return
 		}
+		if named, _ := typ.(*Named); named != nil && named.TParams().Len() > 0 {
+			writeTParamList(buf, named.TParams().list(), qf, nil)
+		}
 		if tname.IsAlias() {
 			buf.WriteString(" =")
 		} else {
diff --git a/src/go/types/object_test.go b/src/go/types/object_test.go
index 2b6057bd934..0ff8fdd6fa6 100644
--- a/src/go/types/object_test.go
+++ b/src/go/types/object_test.go
@@ -22,7 +22,7 @@ func TestIsAlias(t *testing.T) {
 	check(Unsafe.Scope().Lookup("Pointer").(*TypeName), false)
 	for _, name := range Universe.Names() {
 		if obj, _ := Universe.Lookup(name).(*TypeName); obj != nil {
-			check(obj, name == "byte" || name == "rune")
+			check(obj, name == "any" || name == "byte" || name == "rune")
 		}
 	}
 
diff --git a/src/go/types/operand.go b/src/go/types/operand.go
index 6463728cec6..aea8bf5e7ad 100644
--- a/src/go/types/operand.go
+++ b/src/go/types/operand.go
@@ -159,16 +159,20 @@ func operandString(x *operand, qf Qualifier) string {
 	if hasType {
 		if x.typ != Typ[Invalid] {
 			var intro string
-			switch {
-			case isGeneric(x.typ):
-				intro = " of generic type "
-			case asTypeParam(x.typ) != nil:
-				intro = " of type parameter type "
-			default:
+			var tpar *TypeParam
+			if isGeneric(x.typ) {
+				intro = " of parameterized type "
+			} else if tpar = asTypeParam(x.typ); tpar != nil {
+				intro = " of type parameter "
+			} else {
 				intro = " of type "
 			}
 			buf.WriteString(intro)
 			WriteType(&buf, x.typ, qf)
+			if tpar != nil {
+				buf.WriteString(" constrained by ")
+				WriteType(&buf, tpar.bound, qf) // do not compute interface type sets here
+			}
 		} else {
 			buf.WriteString(" with invalid type")
 		}
@@ -233,20 +237,35 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 
 	V := x.typ
 
+	const debugAssignableTo = false
+	if debugAssignableTo && check != nil {
+		check.dump("V = %s", V)
+		check.dump("T = %s", T)
+	}
+
 	// x's type is identical to T
-	if check.identical(V, T) {
+	if Identical(V, T) {
 		return true, 0
 	}
 
 	Vu := optype(V)
 	Tu := optype(T)
 
+	if debugAssignableTo && check != nil {
+		check.dump("Vu = %s", Vu)
+		check.dump("Tu = %s", Tu)
+	}
+
 	// x is an untyped value representable by a value of type T.
 	if isUntyped(Vu) {
-		if t, ok := Tu.(*_Sum); ok {
-			return t.is(func(t Type) bool {
+		if t, ok := Tu.(*Union); ok {
+			return t.is(func(t *term) bool {
 				// TODO(gri) this could probably be more efficient
-				ok, _ := x.assignableTo(check, t, reason)
+				if t.tilde {
+					// TODO(gri) We need to check assignability
+					//           for the underlying type of x.
+				}
+				ok, _ := x.assignableTo(check, t.typ, reason)
 				return ok
 			}), _IncompatibleAssign
 		}
@@ -257,7 +276,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 
 	// x's type V and T have identical underlying types
 	// and at least one of V or T is not a named type
-	if check.identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) {
+	if Identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) {
 		return true, 0
 	}
 
@@ -266,7 +285,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 		if m, wrongType := check.missingMethod(V, Ti, true); m != nil /* Implements(V, Ti) */ {
 			if reason != nil {
 				if wrongType != nil {
-					if check.identical(m.typ, wrongType.typ) {
+					if Identical(m.typ, wrongType.typ) {
 						*reason = fmt.Sprintf("missing method %s (%s has pointer receiver)", m.name, m.name)
 					} else {
 						*reason = fmt.Sprintf("wrong type for method %s (have %s, want %s)", m.Name(), wrongType.typ, m.typ)
@@ -285,7 +304,7 @@ func (x *operand) assignableTo(check *Checker, T Type, reason *string) (bool, er
 	// type, x's type V and T have identical element types,
 	// and at least one of V or T is not a named type
 	if Vc, ok := Vu.(*Chan); ok && Vc.dir == SendRecv {
-		if Tc, ok := Tu.(*Chan); ok && check.identical(Vc.elem, Tc.elem) {
+		if Tc, ok := Tu.(*Chan); ok && Identical(Vc.elem, Tc.elem) {
 			return !isNamed(V) || !isNamed(T), _InvalidChanAssign
 		}
 	}
diff --git a/src/go/types/pointer.go b/src/go/types/pointer.go
new file mode 100644
index 00000000000..6352ee57e2c
--- /dev/null
+++ b/src/go/types/pointer.go
@@ -0,0 +1,19 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// A Pointer represents a pointer type.
+type Pointer struct {
+	base Type // element type
+}
+
+// NewPointer returns a new pointer type for the given element (base) type.
+func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} }
+
+// Elem returns the element type for the given pointer p.
+func (p *Pointer) Elem() Type { return p.base }
+
+func (t *Pointer) Underlying() Type { return t }
+func (t *Pointer) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/predicates.go b/src/go/types/predicates.go
index 7bb026414f8..23924693fd2 100644
--- a/src/go/types/predicates.go
+++ b/src/go/types/predicates.go
@@ -6,15 +6,11 @@
 
 package types
 
-import (
-	"go/token"
-)
-
 // isNamed reports whether typ has a name.
 // isNamed may be called with types that are not fully set up.
 func isNamed(typ Type) bool {
 	switch typ.(type) {
-	case *Basic, *Named, *_TypeParam, *instance:
+	case *Basic, *Named, *TypeParam:
 		return true
 	}
 	return false
@@ -25,15 +21,15 @@ func isNamed(typ Type) bool {
 func isGeneric(typ Type) bool {
 	// A parameterized type is only instantiated if it doesn't have an instantiation already.
 	named, _ := typ.(*Named)
-	return named != nil && named.obj != nil && named.tparams != nil && named.targs == nil
+	return named != nil && named.obj != nil && named.targs == nil && named.TParams() != nil
 }
 
 func is(typ Type, what BasicInfo) bool {
-	switch t := optype(typ).(type) {
+	switch t := under(typ).(type) {
 	case *Basic:
 		return t.info&what != 0
-	case *_Sum:
-		return t.is(func(typ Type) bool { return is(typ, what) })
+	case *TypeParam:
+		return t.underIs(func(typ Type) bool { return is(typ, what) })
 	}
 	return false
 }
@@ -61,9 +57,6 @@ func isNumericOrString(typ Type) bool { return is(typ, IsNumeric|IsString) }
 func isTyped(typ Type) bool {
 	// isTyped is called with types that are not fully
 	// set up. Must not call asBasic()!
-	// A *Named or *instance type is always typed, so
-	// we only need to check if we have a true *Basic
-	// type.
 	t, _ := typ.(*Basic)
 	return t == nil || t.info&IsUntyped == 0
 }
@@ -100,19 +93,7 @@ func comparable(T Type, seen map[Type]bool) bool {
 	}
 	seen[T] = true
 
-	// If T is a type parameter not constrained by any type
-	// list (i.e., it's underlying type is the top type),
-	// T is comparable if it has the == method. Otherwise,
-	// the underlying type "wins". For instance
-	//
-	//     interface{ comparable; type []byte }
-	//
-	// is not comparable because []byte is not comparable.
-	if t := asTypeParam(T); t != nil && optype(t) == theTop {
-		return t.Bound()._IsComparable()
-	}
-
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Basic:
 		// assume invalid types to be comparable
 		// to avoid follow-up errors
@@ -128,42 +109,25 @@ func comparable(T Type, seen map[Type]bool) bool {
 		return true
 	case *Array:
 		return comparable(t.elem, seen)
-	case *_Sum:
-		pred := func(t Type) bool {
-			return comparable(t, seen)
-		}
-		return t.is(pred)
-	case *_TypeParam:
-		return t.Bound()._IsComparable()
+	case *TypeParam:
+		return t.iface().IsComparable()
 	}
 	return false
 }
 
 // hasNil reports whether a type includes the nil value.
 func hasNil(typ Type) bool {
-	switch t := optype(typ).(type) {
+	switch t := under(typ).(type) {
 	case *Basic:
 		return t.kind == UnsafePointer
 	case *Slice, *Pointer, *Signature, *Interface, *Map, *Chan:
 		return true
-	case *_Sum:
-		return t.is(hasNil)
+	case *TypeParam:
+		return t.underIs(hasNil)
 	}
 	return false
 }
 
-// identical reports whether x and y are identical types.
-// Receivers of Signature types are ignored.
-func (check *Checker) identical(x, y Type) bool {
-	return check.identical0(x, y, true, nil)
-}
-
-// identicalIgnoreTags reports whether x and y are identical types if tags are ignored.
-// Receivers of Signature types are ignored.
-func (check *Checker) identicalIgnoreTags(x, y Type) bool {
-	return check.identical0(x, y, false, nil)
-}
-
 // An ifacePair is a node in a stack of interface type pairs compared for identity.
 type ifacePair struct {
 	x, y *Interface
@@ -175,10 +139,10 @@ func (p *ifacePair) identical(q *ifacePair) bool {
 }
 
 // For changes to this code the corresponding changes should be made to unifier.nify.
-func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
+func identical(x, y Type, cmpTags bool, p *ifacePair) bool {
 	// types must be expanded for comparison
-	x = expandf(x)
-	y = expandf(y)
+	x = expand(x)
+	y = expand(y)
 
 	if x == y {
 		return true
@@ -199,13 +163,13 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 		if y, ok := y.(*Array); ok {
 			// If one or both array lengths are unknown (< 0) due to some error,
 			// assume they are the same to avoid spurious follow-on errors.
-			return (x.len < 0 || y.len < 0 || x.len == y.len) && check.identical0(x.elem, y.elem, cmpTags, p)
+			return (x.len < 0 || y.len < 0 || x.len == y.len) && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Slice:
 		// Two slice types are identical if they have identical element types.
 		if y, ok := y.(*Slice); ok {
-			return check.identical0(x.elem, y.elem, cmpTags, p)
+			return identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Struct:
@@ -220,7 +184,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 					if f.embedded != g.embedded ||
 						cmpTags && x.Tag(i) != y.Tag(i) ||
 						!f.sameId(g.pkg, g.name) ||
-						!check.identical0(f.typ, g.typ, cmpTags, p) {
+						!identical(f.typ, g.typ, cmpTags, p) {
 						return false
 					}
 				}
@@ -231,7 +195,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	case *Pointer:
 		// Two pointer types are identical if they have identical base types.
 		if y, ok := y.(*Pointer); ok {
-			return check.identical0(x.base, y.base, cmpTags, p)
+			return identical(x.base, y.base, cmpTags, p)
 		}
 
 	case *Tuple:
@@ -242,7 +206,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 				if x != nil {
 					for i, v := range x.vars {
 						w := y.vars[i]
-						if !check.identical0(v.typ, w.typ, cmpTags, p) {
+						if !identical(v.typ, w.typ, cmpTags, p) {
 							return false
 						}
 					}
@@ -260,49 +224,37 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 		// parameter names.
 		if y, ok := y.(*Signature); ok {
 			return x.variadic == y.variadic &&
-				check.identicalTParams(x.tparams, y.tparams, cmpTags, p) &&
-				check.identical0(x.params, y.params, cmpTags, p) &&
-				check.identical0(x.results, y.results, cmpTags, p)
+				identicalTParams(x.TParams().list(), y.TParams().list(), cmpTags, p) &&
+				identical(x.params, y.params, cmpTags, p) &&
+				identical(x.results, y.results, cmpTags, p)
 		}
 
-	case *_Sum:
-		// Two sum types are identical if they contain the same types.
-		// (Sum types always consist of at least two types. Also, the
-		// the set (list) of types in a sum type consists of unique
-		// types - each type appears exactly once. Thus, two sum types
+	case *Union:
+		// Two union types are identical if they contain the same terms.
+		// The set (list) of types in a union type consists of unique
+		// types - each type appears exactly once. Thus, two union types
 		// must contain the same number of types to have chance of
 		// being equal.
-		if y, ok := y.(*_Sum); ok && len(x.types) == len(y.types) {
-			// Every type in x.types must be in y.types.
-			// Quadratic algorithm, but probably good enough for now.
-			// TODO(gri) we need a fast quick type ID/hash for all types.
-		L:
-			for _, x := range x.types {
-				for _, y := range y.types {
-					if Identical(x, y) {
-						continue L // x is in y.types
-					}
-				}
-				return false // x is not in y.types
-			}
-			return true
+		if y, ok := y.(*Union); ok {
+			return identicalTerms(x.terms, y.terms)
 		}
 
 	case *Interface:
+		// Two interface types are identical if they describe the same type sets.
+		// With the existing implementation restriction, this simplifies to:
+		//
 		// Two interface types are identical if they have the same set of methods with
-		// the same names and identical function types. Lower-case method names from
-		// different packages are always different. The order of the methods is irrelevant.
+		// the same names and identical function types, and if any type restrictions
+		// are the same. Lower-case method names from different packages are always
+		// different. The order of the methods is irrelevant.
 		if y, ok := y.(*Interface); ok {
-			// If identical0 is called (indirectly) via an external API entry point
-			// (such as Identical, IdenticalIgnoreTags, etc.), check is nil. But in
-			// that case, interfaces are expected to be complete and lazy completion
-			// here is not needed.
-			if check != nil {
-				check.completeInterface(token.NoPos, x)
-				check.completeInterface(token.NoPos, y)
+			xset := x.typeSet()
+			yset := y.typeSet()
+			if !Identical(xset.types, yset.types) {
+				return false
 			}
-			a := x.allMethods
-			b := y.allMethods
+			a := xset.methods
+			b := yset.methods
 			if len(a) == len(b) {
 				// Interface types are the only types where cycles can occur
 				// that are not "terminated" via named types; and such cycles
@@ -339,7 +291,7 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 				}
 				for i, f := range a {
 					g := b[i]
-					if f.Id() != g.Id() || !check.identical0(f.typ, g.typ, cmpTags, q) {
+					if f.Id() != g.Id() || !identical(f.typ, g.typ, cmpTags, q) {
 						return false
 					}
 				}
@@ -350,14 +302,14 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	case *Map:
 		// Two map types are identical if they have identical key and value types.
 		if y, ok := y.(*Map); ok {
-			return check.identical0(x.key, y.key, cmpTags, p) && check.identical0(x.elem, y.elem, cmpTags, p)
+			return identical(x.key, y.key, cmpTags, p) && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Chan:
 		// Two channel types are identical if they have identical value types
 		// and the same direction.
 		if y, ok := y.(*Chan); ok {
-			return x.dir == y.dir && check.identical0(x.elem, y.elem, cmpTags, p)
+			return x.dir == y.dir && identical(x.elem, y.elem, cmpTags, p)
 		}
 
 	case *Named:
@@ -370,16 +322,12 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 			return x.obj == y.obj
 		}
 
-	case *_TypeParam:
+	case *TypeParam:
 		// nothing to do (x and y being equal is caught in the very beginning of this function)
 
-	// case *instance:
-	//	unreachable since types are expanded
-
-	case *bottom, *top:
-		// Either both types are theBottom, or both are theTop in which
-		// case the initial x == y check will have caught them. Otherwise
-		// they are not identical.
+	case *top:
+		// Either both types are theTop in which case the initial x == y check
+		// will have caught them. Otherwise they are not identical.
 
 	case nil:
 		// avoid a crash in case of nil type
@@ -391,13 +339,13 @@ func (check *Checker) identical0(x, y Type, cmpTags bool, p *ifacePair) bool {
 	return false
 }
 
-func (check *Checker) identicalTParams(x, y []*TypeName, cmpTags bool, p *ifacePair) bool {
+func identicalTParams(x, y []*TypeName, cmpTags bool, p *ifacePair) bool {
 	if len(x) != len(y) {
 		return false
 	}
 	for i, x := range x {
 		y := y[i]
-		if !check.identical0(x.typ.(*_TypeParam).bound, y.typ.(*_TypeParam).bound, cmpTags, p) {
+		if !identical(x.typ.(*TypeParam).bound, y.typ.(*TypeParam).bound, cmpTags, p) {
 			return false
 		}
 	}
diff --git a/src/go/types/resolver.go b/src/go/types/resolver.go
index f67fc65cd18..5e58c3dcfd5 100644
--- a/src/go/types/resolver.go
+++ b/src/go/types/resolver.go
@@ -276,7 +276,7 @@ func (check *Checker) collectObjects() {
 				}
 
 				if name == "init" {
-					check.errorf(d.spec.Name, _InvalidInitDecl, "cannot import package as init - init must be a func")
+					check.errorf(d.spec, _InvalidInitDecl, "cannot import package as init - init must be a func")
 					return
 				}
 
@@ -309,20 +309,24 @@ func (check *Checker) collectObjects() {
 						check.dotImportMap = make(map[dotImportKey]*PkgName)
 					}
 					// merge imported scope with file scope
-					for _, obj := range imp.scope.elems {
+					for name, obj := range imp.scope.elems {
+						// Note: Avoid eager resolve(name, obj) here, so we only
+						// resolve dot-imported objects as needed.
+
 						// A package scope may contain non-exported objects,
 						// do not import them!
-						if obj.Exported() {
+						if token.IsExported(name) {
 							// declare dot-imported object
 							// (Do not use check.declare because it modifies the object
 							// via Object.setScopePos, which leads to a race condition;
 							// the object may be imported into more than one file scope
 							// concurrently. See issue #32154.)
-							if alt := fileScope.Insert(obj); alt != nil {
-								check.errorf(d.spec.Name, _DuplicateDecl, "%s redeclared in this block", obj.Name())
+							if alt := fileScope.Lookup(name); alt != nil {
+								check.errorf(d.spec.Name, _DuplicateDecl, "%s redeclared in this block", alt.Name())
 								check.reportAltDecl(alt)
 							} else {
-								check.dotImportMap[dotImportKey{fileScope, obj}] = pkgName
+								fileScope.insert(name, obj)
+								check.dotImportMap[dotImportKey{fileScope, name}] = pkgName
 							}
 						}
 					}
@@ -383,7 +387,7 @@ func (check *Checker) collectObjects() {
 				info := &declInfo{file: fileScope, fdecl: d.decl}
 				name := d.decl.Name.Name
 				obj := NewFunc(d.decl.Name.Pos(), pkg, name, nil)
-				if !d.decl.IsMethod() {
+				if d.decl.Recv.NumFields() == 0 {
 					// regular function
 					if d.decl.Recv != nil {
 						check.error(d.decl.Recv, _BadRecv, "method is missing receiver")
@@ -443,8 +447,9 @@ func (check *Checker) collectObjects() {
 
 	// verify that objects in package and file scopes have different names
 	for _, scope := range fileScopes {
-		for _, obj := range scope.elems {
-			if alt := pkg.scope.Lookup(obj.Name()); alt != nil {
+		for name, obj := range scope.elems {
+			if alt := pkg.scope.Lookup(name); alt != nil {
+				obj = resolve(name, obj)
 				if pkg, ok := obj.(*PkgName); ok {
 					check.errorf(alt, _DuplicateDecl, "%s already declared through import of %s", alt.Name(), pkg.Imported())
 					check.reportAltDecl(pkg)
@@ -499,10 +504,12 @@ L: // unpack receiver type
 	}
 
 	// unpack type parameters, if any
-	if ptyp, _ := rtyp.(*ast.IndexExpr); ptyp != nil {
-		rtyp = ptyp.X
+	switch rtyp.(type) {
+	case *ast.IndexExpr, *ast.MultiIndexExpr:
+		ix := typeparams.UnpackIndexExpr(rtyp)
+		rtyp = ix.X
 		if unpackParams {
-			for _, arg := range typeparams.UnpackExpr(ptyp.Index) {
+			for _, arg := range ix.Indices {
 				var par *ast.Ident
 				switch arg := arg.(type) {
 				case *ast.Ident:
@@ -510,7 +517,7 @@ L: // unpack receiver type
 				case *ast.BadExpr:
 					// ignore - error already reported by parser
 				case nil:
-					check.invalidAST(ptyp, "parameterized receiver contains nil parameters")
+					check.invalidAST(ix.Orig, "parameterized receiver contains nil parameters")
 				default:
 					check.errorf(arg, _Todo, "receiver type parameter %s must be an identifier", arg)
 				}
diff --git a/src/go/types/sanitize.go b/src/go/types/sanitize.go
deleted file mode 100644
index 5970ab38c71..00000000000
--- a/src/go/types/sanitize.go
+++ /dev/null
@@ -1,203 +0,0 @@
-// Copyright 2020 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package types
-
-// sanitizeInfo walks the types contained in info to ensure that all instances
-// are expanded.
-//
-// This includes some objects that may be shared across concurrent
-// type-checking passes (such as those in the universe scope), so we are
-// careful here not to write types that are already sanitized. This avoids a
-// data race as any shared types should already be sanitized.
-func sanitizeInfo(info *Info) {
-	var s sanitizer = make(map[Type]Type)
-
-	// Note: Some map entries are not references.
-	// If modified, they must be assigned back.
-
-	for e, tv := range info.Types {
-		if typ := s.typ(tv.Type); typ != tv.Type {
-			tv.Type = typ
-			info.Types[e] = tv
-		}
-	}
-
-	inferred := getInferred(info)
-	for e, inf := range inferred {
-		changed := false
-		for i, targ := range inf.Targs {
-			if typ := s.typ(targ); typ != targ {
-				inf.Targs[i] = typ
-				changed = true
-			}
-		}
-		if typ := s.typ(inf.Sig); typ != inf.Sig {
-			inf.Sig = typ.(*Signature)
-			changed = true
-		}
-		if changed {
-			inferred[e] = inf
-		}
-	}
-
-	for _, obj := range info.Defs {
-		if obj != nil {
-			if typ := s.typ(obj.Type()); typ != obj.Type() {
-				obj.setType(typ)
-			}
-		}
-	}
-
-	for _, obj := range info.Uses {
-		if obj != nil {
-			if typ := s.typ(obj.Type()); typ != obj.Type() {
-				obj.setType(typ)
-			}
-		}
-	}
-
-	// TODO(gri) sanitize as needed
-	// - info.Implicits
-	// - info.Selections
-	// - info.Scopes
-	// - info.InitOrder
-}
-
-type sanitizer map[Type]Type
-
-func (s sanitizer) typ(typ Type) Type {
-	if typ == nil {
-		return nil
-	}
-
-	if t, found := s[typ]; found {
-		return t
-	}
-	s[typ] = typ
-
-	switch t := typ.(type) {
-	case *Basic, *bottom, *top:
-		// nothing to do
-
-	case *Array:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Slice:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Struct:
-		s.varList(t.fields)
-
-	case *Pointer:
-		if base := s.typ(t.base); base != t.base {
-			t.base = base
-		}
-
-	case *Tuple:
-		s.tuple(t)
-
-	case *Signature:
-		s.var_(t.recv)
-		s.tuple(t.params)
-		s.tuple(t.results)
-
-	case *_Sum:
-		s.typeList(t.types)
-
-	case *Interface:
-		s.funcList(t.methods)
-		if types := s.typ(t.types); types != t.types {
-			t.types = types
-		}
-		s.typeList(t.embeddeds)
-		s.funcList(t.allMethods)
-		if allTypes := s.typ(t.allTypes); allTypes != t.allTypes {
-			t.allTypes = allTypes
-		}
-
-	case *Map:
-		if key := s.typ(t.key); key != t.key {
-			t.key = key
-		}
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Chan:
-		if elem := s.typ(t.elem); elem != t.elem {
-			t.elem = elem
-		}
-
-	case *Named:
-		if orig := s.typ(t.orig); orig != t.orig {
-			t.orig = orig
-		}
-		if under := s.typ(t.underlying); under != t.underlying {
-			t.underlying = under
-		}
-		s.typeList(t.targs)
-		s.funcList(t.methods)
-
-	case *_TypeParam:
-		if bound := s.typ(t.bound); bound != t.bound {
-			t.bound = bound
-		}
-
-	case *instance:
-		typ = t.expand()
-		s[t] = typ
-
-	default:
-		panic("unimplemented")
-	}
-
-	return typ
-}
-
-func (s sanitizer) var_(v *Var) {
-	if v != nil {
-		if typ := s.typ(v.typ); typ != v.typ {
-			v.typ = typ
-		}
-	}
-}
-
-func (s sanitizer) varList(list []*Var) {
-	for _, v := range list {
-		s.var_(v)
-	}
-}
-
-func (s sanitizer) tuple(t *Tuple) {
-	if t != nil {
-		s.varList(t.vars)
-	}
-}
-
-func (s sanitizer) func_(f *Func) {
-	if f != nil {
-		if typ := s.typ(f.typ); typ != f.typ {
-			f.typ = typ
-		}
-	}
-}
-
-func (s sanitizer) funcList(list []*Func) {
-	for _, f := range list {
-		s.func_(f)
-	}
-}
-
-func (s sanitizer) typeList(list []Type) {
-	for i, t := range list {
-		if typ := s.typ(t); typ != t {
-			list[i] = typ
-		}
-	}
-}
diff --git a/src/go/types/scope.go b/src/go/types/scope.go
index 26c28d1c4e3..010727eb722 100644
--- a/src/go/types/scope.go
+++ b/src/go/types/scope.go
@@ -13,6 +13,7 @@ import (
 	"io"
 	"sort"
 	"strings"
+	"sync"
 )
 
 // A Scope maintains a set of objects and links to its containing
@@ -22,6 +23,7 @@ import (
 type Scope struct {
 	parent   *Scope
 	children []*Scope
+	number   int               // parent.children[number-1] is this scope; 0 if there is no parent
 	elems    map[string]Object // lazily allocated
 	pos, end token.Pos         // scope extent; may be invalid
 	comment  string            // for debugging only
@@ -31,10 +33,11 @@ type Scope struct {
 // NewScope returns a new, empty scope contained in the given parent
 // scope, if any. The comment is for debugging only.
 func NewScope(parent *Scope, pos, end token.Pos, comment string) *Scope {
-	s := &Scope{parent, nil, nil, pos, end, comment, false}
+	s := &Scope{parent, nil, 0, nil, pos, end, comment, false}
 	// don't add children to Universe scope!
 	if parent != nil && parent != Universe {
 		parent.children = append(parent.children, s)
+		s.number = len(parent.children)
 	}
 	return s
 }
@@ -66,7 +69,7 @@ func (s *Scope) Child(i int) *Scope { return s.children[i] }
 // Lookup returns the object in scope s with the given name if such an
 // object exists; otherwise the result is nil.
 func (s *Scope) Lookup(name string) Object {
-	return s.elems[name]
+	return resolve(name, s.elems[name])
 }
 
 // LookupParent follows the parent chain of scopes starting with s until
@@ -81,7 +84,7 @@ func (s *Scope) Lookup(name string) Object {
 // whose scope is the scope of the package that exported them.
 func (s *Scope) LookupParent(name string, pos token.Pos) (*Scope, Object) {
 	for ; s != nil; s = s.parent {
-		if obj := s.elems[name]; obj != nil && (!pos.IsValid() || obj.scopePos() <= pos) {
+		if obj := s.Lookup(name); obj != nil && (!pos.IsValid() || obj.scopePos() <= pos) {
 			return s, obj
 		}
 	}
@@ -95,19 +98,38 @@ func (s *Scope) LookupParent(name string, pos token.Pos) (*Scope, Object) {
 // if not already set, and returns nil.
 func (s *Scope) Insert(obj Object) Object {
 	name := obj.Name()
-	if alt := s.elems[name]; alt != nil {
+	if alt := s.Lookup(name); alt != nil {
 		return alt
 	}
-	if s.elems == nil {
-		s.elems = make(map[string]Object)
-	}
-	s.elems[name] = obj
+	s.insert(name, obj)
 	if obj.Parent() == nil {
 		obj.setParent(s)
 	}
 	return nil
 }
 
+// _InsertLazy is like Insert, but allows deferring construction of the
+// inserted object until it's accessed with Lookup. The Object
+// returned by resolve must have the same name as given to _InsertLazy.
+// If s already contains an alternative object with the same name,
+// _InsertLazy leaves s unchanged and returns false. Otherwise it
+// records the binding and returns true. The object's parent scope
+// will be set to s after resolve is called.
+func (s *Scope) _InsertLazy(name string, resolve func() Object) bool {
+	if s.elems[name] != nil {
+		return false
+	}
+	s.insert(name, &lazyObject{parent: s, resolve: resolve})
+	return true
+}
+
+func (s *Scope) insert(name string, obj Object) {
+	if s.elems == nil {
+		s.elems = make(map[string]Object)
+	}
+	s.elems[name] = obj
+}
+
 // squash merges s with its parent scope p by adding all
 // objects of s to p, adding all children of s to the
 // children of p, and removing s from p's children.
@@ -117,7 +139,8 @@ func (s *Scope) Insert(obj Object) Object {
 func (s *Scope) squash(err func(obj, alt Object)) {
 	p := s.parent
 	assert(p != nil)
-	for _, obj := range s.elems {
+	for name, obj := range s.elems {
+		obj = resolve(name, obj)
 		obj.setParent(nil)
 		if alt := p.Insert(obj); alt != nil {
 			err(obj, alt)
@@ -196,7 +219,7 @@ func (s *Scope) WriteTo(w io.Writer, n int, recurse bool) {
 
 	indn1 := indn + ind
 	for _, name := range s.Names() {
-		fmt.Fprintf(w, "%s%s\n", indn1, s.elems[name])
+		fmt.Fprintf(w, "%s%s\n", indn1, s.Lookup(name))
 	}
 
 	if recurse {
@@ -214,3 +237,57 @@ func (s *Scope) String() string {
 	s.WriteTo(&buf, 0, false)
 	return buf.String()
 }
+
+// A lazyObject represents an imported Object that has not been fully
+// resolved yet by its importer.
+type lazyObject struct {
+	parent  *Scope
+	resolve func() Object
+	obj     Object
+	once    sync.Once
+}
+
+// resolve returns the Object represented by obj, resolving lazy
+// objects as appropriate.
+func resolve(name string, obj Object) Object {
+	if lazy, ok := obj.(*lazyObject); ok {
+		lazy.once.Do(func() {
+			obj := lazy.resolve()
+
+			if _, ok := obj.(*lazyObject); ok {
+				panic("recursive lazy object")
+			}
+			if obj.Name() != name {
+				panic("lazy object has unexpected name")
+			}
+
+			if obj.Parent() == nil {
+				obj.setParent(lazy.parent)
+			}
+			lazy.obj = obj
+		})
+
+		obj = lazy.obj
+	}
+	return obj
+}
+
+// stub implementations so *lazyObject implements Object and we can
+// store them directly into Scope.elems.
+func (*lazyObject) Parent() *Scope                        { panic("unreachable") }
+func (*lazyObject) Pos() token.Pos                        { panic("unreachable") }
+func (*lazyObject) Pkg() *Package                         { panic("unreachable") }
+func (*lazyObject) Name() string                          { panic("unreachable") }
+func (*lazyObject) Type() Type                            { panic("unreachable") }
+func (*lazyObject) Exported() bool                        { panic("unreachable") }
+func (*lazyObject) Id() string                            { panic("unreachable") }
+func (*lazyObject) String() string                        { panic("unreachable") }
+func (*lazyObject) order() uint32                         { panic("unreachable") }
+func (*lazyObject) color() color                          { panic("unreachable") }
+func (*lazyObject) setType(Type)                          { panic("unreachable") }
+func (*lazyObject) setOrder(uint32)                       { panic("unreachable") }
+func (*lazyObject) setColor(color color)                  { panic("unreachable") }
+func (*lazyObject) setParent(*Scope)                      { panic("unreachable") }
+func (*lazyObject) sameId(pkg *Package, name string) bool { panic("unreachable") }
+func (*lazyObject) scopePos() token.Pos                   { panic("unreachable") }
+func (*lazyObject) setScopePos(pos token.Pos)             { panic("unreachable") }
diff --git a/src/go/types/signature.go b/src/go/types/signature.go
new file mode 100644
index 00000000000..5a69bb17b57
--- /dev/null
+++ b/src/go/types/signature.go
@@ -0,0 +1,352 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"fmt"
+	"go/ast"
+	"go/internal/typeparams"
+	"go/token"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Signature represents a (non-builtin) function or method type.
+// The receiver is ignored when comparing signatures for identity.
+type Signature struct {
+	// We need to keep the scope in Signature (rather than passing it around
+	// and store it in the Func Object) because when type-checking a function
+	// literal we call the general type checker which returns a general Type.
+	// We then unpack the *Signature and use the scope for the literal body.
+	rparams  *TypeParams // receiver type parameters from left to right, or nil
+	tparams  *TypeParams // type parameters from left to right, or nil
+	scope    *Scope      // function scope, present for package-local signatures
+	recv     *Var        // nil if not a method
+	params   *Tuple      // (incoming) parameters from left to right; or nil
+	results  *Tuple      // (outgoing) results from left to right; or nil
+	variadic bool        // true if the last parameter's type is of the form ...T (or string, for append built-in only)
+}
+
+// NewSignature returns a new function type for the given receiver, parameters,
+// and results, either of which may be nil. If variadic is set, the function
+// is variadic, it must have at least one parameter, and the last parameter
+// must be of unnamed slice type.
+func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature {
+	if variadic {
+		n := params.Len()
+		if n == 0 {
+			panic("types.NewSignature: variadic function must have at least one parameter")
+		}
+		if _, ok := params.At(n - 1).typ.(*Slice); !ok {
+			panic("types.NewSignature: variadic parameter must be of unnamed slice type")
+		}
+	}
+	return &Signature{recv: recv, params: params, results: results, variadic: variadic}
+}
+
+// Recv returns the receiver of signature s (if a method), or nil if a
+// function. It is ignored when comparing signatures for identity.
+//
+// For an abstract method, Recv returns the enclosing interface either
+// as a *Named or an *Interface. Due to embedding, an interface may
+// contain methods whose receiver type is a different interface.
+func (s *Signature) Recv() *Var { return s.recv }
+
+// TParams returns the type parameters of signature s, or nil.
+func (s *Signature) TParams() *TypeParams { return s.tparams }
+
+// SetTParams sets the type parameters of signature s.
+func (s *Signature) SetTParams(tparams []*TypeName) { s.tparams = bindTParams(tparams) }
+
+// RParams returns the receiver type parameters of signature s, or nil.
+func (s *Signature) RParams() *TypeParams { return s.rparams }
+
+// SetRParams sets the receiver type params of signature s.
+func (s *Signature) SetRParams(rparams []*TypeName) { s.rparams = bindTParams(rparams) }
+
+// Params returns the parameters of signature s, or nil.
+func (s *Signature) Params() *Tuple { return s.params }
+
+// Results returns the results of signature s, or nil.
+func (s *Signature) Results() *Tuple { return s.results }
+
+// Variadic reports whether the signature s is variadic.
+func (s *Signature) Variadic() bool { return s.variadic }
+
+func (t *Signature) Underlying() Type { return t }
+func (t *Signature) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// funcType type-checks a function or method type.
+func (check *Checker) funcType(sig *Signature, recvPar *ast.FieldList, ftyp *ast.FuncType) {
+	check.openScope(ftyp, "function")
+	check.scope.isFunc = true
+	check.recordScope(ftyp, check.scope)
+	sig.scope = check.scope
+	defer check.closeScope()
+
+	var recvTyp ast.Expr // rewritten receiver type; valid if != nil
+	if recvPar != nil && len(recvPar.List) > 0 {
+		// collect generic receiver type parameters, if any
+		// - a receiver type parameter is like any other type parameter, except that it is declared implicitly
+		// - the receiver specification acts as local declaration for its type parameters, which may be blank
+		_, rname, rparams := check.unpackRecv(recvPar.List[0].Type, true)
+		if len(rparams) > 0 {
+			// Blank identifiers don't get declared and regular type-checking of the instantiated
+			// parameterized receiver type expression fails in Checker.collectParams of receiver.
+			// Identify blank type parameters and substitute each with a unique new identifier named
+			// "n_" (where n is the parameter index) and which cannot conflict with any user-defined
+			// name.
+			var smap map[*ast.Ident]*ast.Ident // substitution map from "_" to "n_" identifiers
+			for i, p := range rparams {
+				if p.Name == "_" {
+					new := *p
+					new.Name = fmt.Sprintf("%d_", i)
+					rparams[i] = &new // use n_ identifier instead of _ so it can be looked up
+					if smap == nil {
+						smap = make(map[*ast.Ident]*ast.Ident)
+					}
+					smap[p] = &new
+				}
+			}
+			if smap != nil {
+				// blank identifiers were found => use rewritten receiver type
+				recvTyp = isubst(recvPar.List[0].Type, smap)
+			}
+			sig.rparams = bindTParams(check.declareTypeParams(nil, rparams))
+			// determine receiver type to get its type parameters
+			// and the respective type parameter bounds
+			var recvTParams []*TypeName
+			if rname != nil {
+				// recv should be a Named type (otherwise an error is reported elsewhere)
+				// Also: Don't report an error via genericType since it will be reported
+				//       again when we type-check the signature.
+				// TODO(gri) maybe the receiver should be marked as invalid instead?
+				if recv := asNamed(check.genericType(rname, false)); recv != nil {
+					recvTParams = recv.TParams().list()
+				}
+			}
+			// provide type parameter bounds
+			// - only do this if we have the right number (otherwise an error is reported elsewhere)
+			if sig.RParams().Len() == len(recvTParams) {
+				// We have a list of *TypeNames but we need a list of Types.
+				list := make([]Type, sig.RParams().Len())
+				for i, t := range sig.RParams().list() {
+					list[i] = t.typ
+				}
+				smap := makeSubstMap(recvTParams, list)
+				for i, tname := range sig.RParams().list() {
+					bound := recvTParams[i].typ.(*TypeParam).bound
+					// bound is (possibly) parameterized in the context of the
+					// receiver type declaration. Substitute parameters for the
+					// current context.
+					// TODO(gri) should we assume now that bounds always exist?
+					//           (no bound == empty interface)
+					if bound != nil {
+						bound = check.subst(tname.pos, bound, smap)
+						tname.typ.(*TypeParam).bound = bound
+					}
+				}
+			}
+		}
+	}
+
+	if tparams := typeparams.Get(ftyp); tparams != nil {
+		sig.tparams = check.collectTypeParams(tparams)
+		// Always type-check method type parameters but complain that they are not allowed.
+		// (A separate check is needed when type-checking interface method signatures because
+		// they don't have a receiver specification.)
+		if recvPar != nil {
+			check.errorf(tparams, _Todo, "methods cannot have type parameters")
+		}
+	}
+
+	// Value (non-type) parameters' scope starts in the function body. Use a temporary scope for their
+	// declarations and then squash that scope into the parent scope (and report any redeclarations at
+	// that time).
+	scope := NewScope(check.scope, token.NoPos, token.NoPos, "function body (temp. scope)")
+	recvList, _ := check.collectParams(scope, recvPar, recvTyp, false) // use rewritten receiver type, if any
+	params, variadic := check.collectParams(scope, ftyp.Params, nil, true)
+	results, _ := check.collectParams(scope, ftyp.Results, nil, false)
+	scope.squash(func(obj, alt Object) {
+		check.errorf(obj, _DuplicateDecl, "%s redeclared in this block", obj.Name())
+		check.reportAltDecl(alt)
+	})
+
+	if recvPar != nil {
+		// recv parameter list present (may be empty)
+		// spec: "The receiver is specified via an extra parameter section preceding the
+		// method name. That parameter section must declare a single parameter, the receiver."
+		var recv *Var
+		switch len(recvList) {
+		case 0:
+			// error reported by resolver
+			recv = NewParam(0, nil, "", Typ[Invalid]) // ignore recv below
+		default:
+			// more than one receiver
+			check.error(recvList[len(recvList)-1], _BadRecv, "method must have exactly one receiver")
+			fallthrough // continue with first receiver
+		case 1:
+			recv = recvList[0]
+		}
+
+		// TODO(gri) We should delay rtyp expansion to when we actually need the
+		//           receiver; thus all checks here should be delayed to later.
+		rtyp, _ := deref(recv.typ)
+		rtyp = expand(rtyp)
+
+		// spec: "The receiver type must be of the form T or *T where T is a type name."
+		// (ignore invalid types - error was reported before)
+		if rtyp != Typ[Invalid] {
+			var err string
+			switch T := rtyp.(type) {
+			case *Named:
+				// spec: "The type denoted by T is called the receiver base type; it must not
+				// be a pointer or interface type and it must be declared in the same package
+				// as the method."
+				if T.obj.pkg != check.pkg {
+					err = "type not defined in this package"
+				} else {
+					// The underlying type of a receiver base type can be a type parameter;
+					// e.g. for methods with a generic receiver T[P] with type T[P any] P.
+					underIs(T, func(u Type) bool {
+						switch u := u.(type) {
+						case *Basic:
+							// unsafe.Pointer is treated like a regular pointer
+							if u.kind == UnsafePointer {
+								err = "unsafe.Pointer"
+								return false
+							}
+						case *Pointer, *Interface:
+							err = "pointer or interface type"
+							return false
+						}
+						return true
+					})
+				}
+			case *Basic:
+				err = "basic or unnamed type"
+			default:
+				check.errorf(recv, _InvalidRecv, "invalid receiver type %s", recv.typ)
+			}
+			if err != "" {
+				check.errorf(recv, _InvalidRecv, "invalid receiver type %s (%s)", recv.typ, err)
+				// ok to continue
+			}
+		}
+		sig.recv = recv
+	}
+
+	sig.params = NewTuple(params...)
+	sig.results = NewTuple(results...)
+	sig.variadic = variadic
+}
+
+// collectParams declares the parameters of list in scope and returns the corresponding
+// variable list. If type0 != nil, it is used instead of the first type in list.
+func (check *Checker) collectParams(scope *Scope, list *ast.FieldList, type0 ast.Expr, variadicOk bool) (params []*Var, variadic bool) {
+	if list == nil {
+		return
+	}
+
+	var named, anonymous bool
+	for i, field := range list.List {
+		ftype := field.Type
+		if i == 0 && type0 != nil {
+			ftype = type0
+		}
+		if t, _ := ftype.(*ast.Ellipsis); t != nil {
+			ftype = t.Elt
+			if variadicOk && i == len(list.List)-1 && len(field.Names) <= 1 {
+				variadic = true
+			} else {
+				check.softErrorf(t, _MisplacedDotDotDot, "can only use ... with final parameter in list")
+				// ignore ... and continue
+			}
+		}
+		typ := check.varType(ftype)
+		// The parser ensures that f.Tag is nil and we don't
+		// care if a constructed AST contains a non-nil tag.
+		if len(field.Names) > 0 {
+			// named parameter
+			for _, name := range field.Names {
+				if name.Name == "" {
+					check.invalidAST(name, "anonymous parameter")
+					// ok to continue
+				}
+				par := NewParam(name.Pos(), check.pkg, name.Name, typ)
+				check.declare(scope, name, par, scope.pos)
+				params = append(params, par)
+			}
+			named = true
+		} else {
+			// anonymous parameter
+			par := NewParam(ftype.Pos(), check.pkg, "", typ)
+			check.recordImplicit(field, par)
+			params = append(params, par)
+			anonymous = true
+		}
+	}
+
+	if named && anonymous {
+		check.invalidAST(list, "list contains both named and anonymous parameters")
+		// ok to continue
+	}
+
+	// For a variadic function, change the last parameter's type from T to []T.
+	// Since we type-checked T rather than ...T, we also need to retro-actively
+	// record the type for ...T.
+	if variadic {
+		last := params[len(params)-1]
+		last.typ = &Slice{elem: last.typ}
+		check.recordTypeAndValue(list.List[len(list.List)-1].Type, typexpr, last.typ, nil)
+	}
+
+	return
+}
+
+// isubst returns an x with identifiers substituted per the substitution map smap.
+// isubst only handles the case of (valid) method receiver type expressions correctly.
+func isubst(x ast.Expr, smap map[*ast.Ident]*ast.Ident) ast.Expr {
+	switch n := x.(type) {
+	case *ast.Ident:
+		if alt := smap[n]; alt != nil {
+			return alt
+		}
+	case *ast.StarExpr:
+		X := isubst(n.X, smap)
+		if X != n.X {
+			new := *n
+			new.X = X
+			return &new
+		}
+	case *ast.IndexExpr, *ast.MultiIndexExpr:
+		ix := typeparams.UnpackIndexExpr(x)
+		var newIndexes []ast.Expr
+		for i, index := range ix.Indices {
+			new := isubst(index, smap)
+			if new != index {
+				if newIndexes == nil {
+					newIndexes = make([]ast.Expr, len(ix.Indices))
+					copy(newIndexes, ix.Indices)
+				}
+				newIndexes[i] = new
+			}
+		}
+		if newIndexes != nil {
+			return typeparams.PackIndexExpr(ix.X, ix.Lbrack, newIndexes, ix.Rbrack)
+		}
+	case *ast.ParenExpr:
+		return isubst(n.X, smap) // no need to keep parentheses
+	default:
+		// Other receiver type expressions are invalid.
+		// It's fine to ignore those here as they will
+		// be checked elsewhere.
+	}
+	return x
+}
diff --git a/src/go/types/sizeof_test.go b/src/go/types/sizeof_test.go
index 5a9d07ca418..67a9b39558e 100644
--- a/src/go/types/sizeof_test.go
+++ b/src/go/types/sizeof_test.go
@@ -25,15 +25,14 @@ func TestSizeof(t *testing.T) {
 		{Struct{}, 24, 48},
 		{Pointer{}, 8, 16},
 		{Tuple{}, 12, 24},
-		{Signature{}, 44, 88},
-		{_Sum{}, 12, 24},
-		{Interface{}, 60, 120},
+		{Signature{}, 28, 56},
+		{Union{}, 12, 24},
+		{Interface{}, 40, 80},
 		{Map{}, 16, 32},
 		{Chan{}, 12, 24},
-		{Named{}, 64, 128},
-		{_TypeParam{}, 28, 48},
-		{instance{}, 44, 88},
-		{bottom{}, 0, 0},
+		{Named{}, 80, 152},
+		{TypeParam{}, 28, 48},
+		{term{}, 12, 24},
 		{top{}, 0, 0},
 
 		// Objects
@@ -47,8 +46,9 @@ func TestSizeof(t *testing.T) {
 		{Nil{}, 40, 72},
 
 		// Misc
-		{Scope{}, 40, 80},
+		{Scope{}, 44, 88},
 		{Package{}, 40, 80},
+		{_TypeSet{}, 24, 48},
 	}
 	for _, test := range tests {
 		got := reflect.TypeOf(test.val).Size()
diff --git a/src/go/types/sizes.go b/src/go/types/sizes.go
index 67052bb816e..4c85bfe057f 100644
--- a/src/go/types/sizes.go
+++ b/src/go/types/sizes.go
@@ -48,7 +48,7 @@ type StdSizes struct {
 func (s *StdSizes) Alignof(T Type) int64 {
 	// For arrays and structs, alignment is defined in terms
 	// of alignment of the elements and fields, respectively.
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Array:
 		// spec: "For a variable x of array type: unsafe.Alignof(x)
 		// is the same as unsafe.Alignof(x[0]), but at least 1."
@@ -73,6 +73,8 @@ func (s *StdSizes) Alignof(T Type) int64 {
 		if t.Info()&IsString != 0 {
 			return s.WordSize
 		}
+	case *TypeParam, *Union:
+		unreachable()
 	}
 	a := s.Sizeof(T) // may be 0
 	// spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1."
@@ -118,7 +120,7 @@ var basicSizes = [...]byte{
 }
 
 func (s *StdSizes) Sizeof(T Type) int64 {
-	switch t := optype(T).(type) {
+	switch t := under(T).(type) {
 	case *Basic:
 		assert(isTyped(T))
 		k := t.kind
@@ -148,10 +150,10 @@ func (s *StdSizes) Sizeof(T Type) int64 {
 		}
 		offsets := s.Offsetsof(t.fields)
 		return offsets[n-1] + s.Sizeof(t.fields[n-1].typ)
-	case *_Sum:
-		panic("Sizeof unimplemented for type sum")
 	case *Interface:
 		return s.WordSize * 2
+	case *TypeParam, *Union:
+		unreachable()
 	}
 	return s.WordSize // catch-all
 }
diff --git a/src/go/types/slice.go b/src/go/types/slice.go
new file mode 100644
index 00000000000..debdd81586c
--- /dev/null
+++ b/src/go/types/slice.go
@@ -0,0 +1,19 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// A Slice represents a slice type.
+type Slice struct {
+	elem Type
+}
+
+// NewSlice returns a new slice type for the given element type.
+func NewSlice(elem Type) *Slice { return &Slice{elem: elem} }
+
+// Elem returns the element type of slice s.
+func (s *Slice) Elem() Type { return s.elem }
+
+func (t *Slice) Underlying() Type { return t }
+func (t *Slice) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/stdlib_test.go b/src/go/types/stdlib_test.go
index 3dea8dcf1ed..3eb7519a91a 100644
--- a/src/go/types/stdlib_test.go
+++ b/src/go/types/stdlib_test.go
@@ -26,9 +26,15 @@ import (
 	. "go/types"
 )
 
+// The cmd/*/internal packages may have been deleted as part of a binary
+// release. Import from source instead.
+//
+// (See https://golang.org/issue/43232 and
+// https://github.com/golang/build/blob/df58bbac082bc87c4a3cdfe336d1ffe60bbaa916/cmd/release/release.go#L533-L545.)
+//
 // Use the same importer for all std lib tests to
 // avoid repeated importing of the same packages.
-var stdLibImporter = importer.Default()
+var stdLibImporter = importer.ForCompiler(token.NewFileSet(), "source", nil)
 
 func TestStdlib(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
diff --git a/src/go/types/stmt.go b/src/go/types/stmt.go
index 47f6dcfbd1c..0f0a2e4d9fd 100644
--- a/src/go/types/stmt.go
+++ b/src/go/types/stmt.go
@@ -65,7 +65,8 @@ func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body
 
 func (check *Checker) usage(scope *Scope) {
 	var unused []*Var
-	for _, elem := range scope.elems {
+	for name, elem := range scope.elems {
+		elem = resolve(name, elem)
 		if v, _ := elem.(*Var); v != nil && !v.used {
 			unused = append(unused, v)
 		}
@@ -264,7 +265,7 @@ L:
 			// look for duplicate types for a given value
 			// (quadratic algorithm, but these lists tend to be very short)
 			for _, vt := range seen[val] {
-				if check.identical(v.typ, vt.typ) {
+				if Identical(v.typ, vt.typ) {
 					check.errorf(&v, _DuplicateCase, "duplicate case %s in expression switch", &v)
 					check.error(atPos(vt.pos), _DuplicateCase, "\tprevious case") // secondary error, \t indented
 					continue L
@@ -288,7 +289,7 @@ L:
 		// look for duplicate types
 		// (quadratic algorithm, but type switches tend to be reasonably small)
 		for t, other := range seen {
-			if T == nil && t == nil || T != nil && t != nil && check.identical(T, t) {
+			if T == nil && t == nil || T != nil && t != nil && Identical(T, t) {
 				// talk about "case" rather than "type" because of nil case
 				Ts := "nil"
 				if T != nil {
@@ -360,25 +361,33 @@ func (check *Checker) stmt(ctxt stmtContext, s ast.Stmt) {
 		check.errorf(&x, code, "%s %s", &x, msg)
 
 	case *ast.SendStmt:
-		var ch, x operand
+		var ch, val operand
 		check.expr(&ch, s.Chan)
-		check.expr(&x, s.Value)
-		if ch.mode == invalid || x.mode == invalid {
+		check.expr(&val, s.Value)
+		if ch.mode == invalid || val.mode == invalid {
 			return
 		}
-
-		tch := asChan(ch.typ)
-		if tch == nil {
-			check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to non-chan type %s", ch.typ)
+		var elem Type
+		if !underIs(ch.typ, func(u Type) bool {
+			uch, _ := u.(*Chan)
+			if uch == nil {
+				check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to non-channel %s", &ch)
+				return false
+			}
+			if uch.dir == RecvOnly {
+				check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to receive-only channel %s", &ch)
+				return false
+			}
+			if elem != nil && !Identical(uch.elem, elem) {
+				check.invalidOp(inNode(s, s.Arrow), _Todo, "channels of %s must have the same element type", &ch)
+				return false
+			}
+			elem = uch.elem
+			return true
+		}) {
 			return
 		}
-
-		if tch.dir == RecvOnly {
-			check.invalidOp(inNode(s, s.Arrow), _InvalidSend, "cannot send to receive-only type %s", tch)
-			return
-		}
-
-		check.assignment(&x, tch.elem, "send")
+		check.assignment(&val, elem, "send")
 
 	case *ast.IncDecStmt:
 		var op token.Token
@@ -911,12 +920,12 @@ func rangeKeyVal(typ Type, wantKey, wantVal bool) (Type, Type, string) {
 			msg = "send-only channel"
 		}
 		return typ.elem, Typ[Invalid], msg
-	case *_Sum:
+	case *Union:
 		first := true
 		var key, val Type
 		var msg string
-		typ.is(func(t Type) bool {
-			k, v, m := rangeKeyVal(under(t), wantKey, wantVal)
+		typ.underIs(func(t Type) bool {
+			k, v, m := rangeKeyVal(t, wantKey, wantVal)
 			if k == nil || m != "" {
 				key, val, msg = k, v, m
 				return false
diff --git a/src/go/types/struct.go b/src/go/types/struct.go
new file mode 100644
index 00000000000..48b07346dc3
--- /dev/null
+++ b/src/go/types/struct.go
@@ -0,0 +1,202 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"go/ast"
+	"go/token"
+	"strconv"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Struct represents a struct type.
+type Struct struct {
+	fields []*Var
+	tags   []string // field tags; nil if there are no tags
+}
+
+// NewStruct returns a new struct with the given fields and corresponding field tags.
+// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be
+// only as long as required to hold the tag with the largest index i. Consequently,
+// if no field has a tag, tags may be nil.
+func NewStruct(fields []*Var, tags []string) *Struct {
+	var fset objset
+	for _, f := range fields {
+		if f.name != "_" && fset.insert(f) != nil {
+			panic("multiple fields with the same name")
+		}
+	}
+	if len(tags) > len(fields) {
+		panic("more tags than fields")
+	}
+	return &Struct{fields: fields, tags: tags}
+}
+
+// NumFields returns the number of fields in the struct (including blank and embedded fields).
+func (s *Struct) NumFields() int { return len(s.fields) }
+
+// Field returns the i'th field for 0 <= i < NumFields().
+func (s *Struct) Field(i int) *Var { return s.fields[i] }
+
+// Tag returns the i'th field tag for 0 <= i < NumFields().
+func (s *Struct) Tag(i int) string {
+	if i < len(s.tags) {
+		return s.tags[i]
+	}
+	return ""
+}
+
+func (t *Struct) Underlying() Type { return t }
+func (t *Struct) String() string   { return TypeString(t, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (check *Checker) structType(styp *Struct, e *ast.StructType) {
+	list := e.Fields
+	if list == nil {
+		return
+	}
+
+	// struct fields and tags
+	var fields []*Var
+	var tags []string
+
+	// for double-declaration checks
+	var fset objset
+
+	// current field typ and tag
+	var typ Type
+	var tag string
+	add := func(ident *ast.Ident, embedded bool, pos token.Pos) {
+		if tag != "" && tags == nil {
+			tags = make([]string, len(fields))
+		}
+		if tags != nil {
+			tags = append(tags, tag)
+		}
+
+		name := ident.Name
+		fld := NewField(pos, check.pkg, name, typ, embedded)
+		// spec: "Within a struct, non-blank field names must be unique."
+		if name == "_" || check.declareInSet(&fset, pos, fld) {
+			fields = append(fields, fld)
+			check.recordDef(ident, fld)
+		}
+	}
+
+	// addInvalid adds an embedded field of invalid type to the struct for
+	// fields with errors; this keeps the number of struct fields in sync
+	// with the source as long as the fields are _ or have different names
+	// (issue #25627).
+	addInvalid := func(ident *ast.Ident, pos token.Pos) {
+		typ = Typ[Invalid]
+		tag = ""
+		add(ident, true, pos)
+	}
+
+	for _, f := range list.List {
+		typ = check.varType(f.Type)
+		tag = check.tag(f.Tag)
+		if len(f.Names) > 0 {
+			// named fields
+			for _, name := range f.Names {
+				add(name, false, name.Pos())
+			}
+		} else {
+			// embedded field
+			// spec: "An embedded type must be specified as a type name T or as a
+			// pointer to a non-interface type name *T, and T itself may not be a
+			// pointer type."
+			pos := f.Type.Pos()
+			name := embeddedFieldIdent(f.Type)
+			if name == nil {
+				// TODO(rFindley): using invalidAST here causes test failures (all
+				//                 errors should have codes). Clean this up.
+				check.errorf(f.Type, _Todo, "invalid AST: embedded field type %s has no name", f.Type)
+				name = ast.NewIdent("_")
+				name.NamePos = pos
+				addInvalid(name, pos)
+				continue
+			}
+			add(name, true, pos)
+
+			// Because we have a name, typ must be of the form T or *T, where T is the name
+			// of a (named or alias) type, and t (= deref(typ)) must be the type of T.
+			// We must delay this check to the end because we don't want to instantiate
+			// (via under(t)) a possibly incomplete type.
+
+			// for use in the closure below
+			embeddedTyp := typ
+			embeddedPos := f.Type
+
+			check.later(func() {
+				t, isPtr := deref(embeddedTyp)
+				switch t := under(t).(type) {
+				case *Basic:
+					if t == Typ[Invalid] {
+						// error was reported before
+						return
+					}
+					// unsafe.Pointer is treated like a regular pointer
+					if t.kind == UnsafePointer {
+						check.error(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be unsafe.Pointer")
+					}
+				case *Pointer:
+					check.error(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be a pointer")
+				case *TypeParam:
+					check.error(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be a (pointer to a) type parameter")
+				case *Interface:
+					if isPtr {
+						check.error(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be a pointer to an interface")
+					}
+				}
+			})
+		}
+	}
+
+	styp.fields = fields
+	styp.tags = tags
+}
+
+func embeddedFieldIdent(e ast.Expr) *ast.Ident {
+	switch e := e.(type) {
+	case *ast.Ident:
+		return e
+	case *ast.StarExpr:
+		// *T is valid, but **T is not
+		if _, ok := e.X.(*ast.StarExpr); !ok {
+			return embeddedFieldIdent(e.X)
+		}
+	case *ast.SelectorExpr:
+		return e.Sel
+	case *ast.IndexExpr:
+		return embeddedFieldIdent(e.X)
+	}
+	return nil // invalid embedded field
+}
+
+func (check *Checker) declareInSet(oset *objset, pos token.Pos, obj Object) bool {
+	if alt := oset.insert(obj); alt != nil {
+		check.errorf(atPos(pos), _DuplicateDecl, "%s redeclared", obj.Name())
+		check.reportAltDecl(alt)
+		return false
+	}
+	return true
+}
+
+func (check *Checker) tag(t *ast.BasicLit) string {
+	if t != nil {
+		if t.Kind == token.STRING {
+			if val, err := strconv.Unquote(t.Value); err == nil {
+				return val
+			}
+		}
+		check.invalidAST(t, "incorrect tag syntax: %q", t.Value)
+	}
+	return ""
+}
diff --git a/src/go/types/subst.go b/src/go/types/subst.go
index 931375f1f2b..322e30d3577 100644
--- a/src/go/types/subst.go
+++ b/src/go/types/subst.go
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// This file implements instantiation of generic types
-// through substitution of type parameters by actual
-// types.
+// This file implements type parameter substitution.
 
 package types
 
@@ -22,21 +20,16 @@ type substMap struct {
 	// TODO(gri) rewrite that code, get rid of this field, and make this
 	//           struct just the map (proj)
 	targs []Type
-	proj  map[*_TypeParam]Type
+	proj  map[*TypeParam]Type
 }
 
 // makeSubstMap creates a new substitution map mapping tpars[i] to targs[i].
 // If targs[i] is nil, tpars[i] is not substituted.
 func makeSubstMap(tpars []*TypeName, targs []Type) *substMap {
 	assert(len(tpars) == len(targs))
-	proj := make(map[*_TypeParam]Type, len(tpars))
+	proj := make(map[*TypeParam]Type, len(tpars))
 	for i, tpar := range tpars {
-		// We must expand type arguments otherwise *instance
-		// types end up as components in composite types.
-		// TODO(gri) explain why this causes problems, if it does
-		targ := expand(targs[i]) // possibly nil
-		targs[i] = targ
-		proj[tpar.typ.(*_TypeParam)] = targ
+		proj[tpar.typ.(*TypeParam)] = targs[i]
 	}
 	return &substMap{targs, proj}
 }
@@ -49,165 +42,13 @@ func (m *substMap) empty() bool {
 	return len(m.proj) == 0
 }
 
-func (m *substMap) lookup(tpar *_TypeParam) Type {
+func (m *substMap) lookup(tpar *TypeParam) Type {
 	if t := m.proj[tpar]; t != nil {
 		return t
 	}
 	return tpar
 }
 
-func (check *Checker) instantiate(pos token.Pos, typ Type, targs []Type, poslist []token.Pos) (res Type) {
-	if trace {
-		check.trace(pos, "-- instantiating %s with %s", typ, typeListString(targs))
-		check.indent++
-		defer func() {
-			check.indent--
-			var under Type
-			if res != nil {
-				// Calling under() here may lead to endless instantiations.
-				// Test case: type T[P any] T[P]
-				// TODO(gri) investigate if that's a bug or to be expected.
-				under = res.Underlying()
-			}
-			check.trace(pos, "=> %s (under = %s)", res, under)
-		}()
-	}
-
-	assert(len(poslist) <= len(targs))
-
-	// TODO(gri) What is better here: work with TypeParams, or work with TypeNames?
-	var tparams []*TypeName
-	switch t := typ.(type) {
-	case *Named:
-		tparams = t.tparams
-	case *Signature:
-		tparams = t.tparams
-		defer func() {
-			// If we had an unexpected failure somewhere don't panic below when
-			// asserting res.(*Signature). Check for *Signature in case Typ[Invalid]
-			// is returned.
-			if _, ok := res.(*Signature); !ok {
-				return
-			}
-			// If the signature doesn't use its type parameters, subst
-			// will not make a copy. In that case, make a copy now (so
-			// we can set tparams to nil w/o causing side-effects).
-			if t == res {
-				copy := *t
-				res = ©
-			}
-			// After instantiating a generic signature, it is not generic
-			// anymore; we need to set tparams to nil.
-			res.(*Signature).tparams = nil
-		}()
-
-	default:
-		check.dump("%v: cannot instantiate %v", pos, typ)
-		unreachable() // only defined types and (defined) functions can be generic
-	}
-
-	// the number of supplied types must match the number of type parameters
-	if len(targs) != len(tparams) {
-		// TODO(gri) provide better error message
-		check.errorf(atPos(pos), _Todo, "got %d arguments but %d type parameters", len(targs), len(tparams))
-		return Typ[Invalid]
-	}
-
-	if len(tparams) == 0 {
-		return typ // nothing to do (minor optimization)
-	}
-
-	smap := makeSubstMap(tparams, targs)
-
-	// check bounds
-	for i, tname := range tparams {
-		tpar := tname.typ.(*_TypeParam)
-		iface := tpar.Bound()
-		if iface.Empty() {
-			continue // no type bound
-		}
-
-		targ := targs[i]
-
-		// best position for error reporting
-		pos := pos
-		if i < len(poslist) {
-			pos = poslist[i]
-		}
-
-		// The type parameter bound is parameterized with the same type parameters
-		// as the instantiated type; before we can use it for bounds checking we
-		// need to instantiate it with the type arguments with which we instantiate
-		// the parameterized type.
-		iface = check.subst(pos, iface, smap).(*Interface)
-
-		// targ must implement iface (methods)
-		// - check only if we have methods
-		check.completeInterface(token.NoPos, iface)
-		if len(iface.allMethods) > 0 {
-			// If the type argument is a pointer to a type parameter, the type argument's
-			// method set is empty.
-			// TODO(gri) is this what we want? (spec question)
-			if base, isPtr := deref(targ); isPtr && asTypeParam(base) != nil {
-				check.errorf(atPos(pos), 0, "%s has no methods", targ)
-				break
-			}
-			if m, wrong := check.missingMethod(targ, iface, true); m != nil {
-				// TODO(gri) needs to print updated name to avoid major confusion in error message!
-				//           (print warning for now)
-				// Old warning:
-				// check.softErrorf(pos, "%s does not satisfy %s (warning: name not updated) = %s (missing method %s)", targ, tpar.bound, iface, m)
-				if m.name == "==" {
-					// We don't want to report "missing method ==".
-					check.softErrorf(atPos(pos), 0, "%s does not satisfy comparable", targ)
-				} else if wrong != nil {
-					// TODO(gri) This can still report uninstantiated types which makes the error message
-					//           more difficult to read then necessary.
-					// TODO(rFindley) should this use parentheses rather than ':' for qualification?
-					check.softErrorf(atPos(pos), _Todo,
-						"%s does not satisfy %s: wrong method signature\n\tgot  %s\n\twant %s",
-						targ, tpar.bound, wrong, m,
-					)
-				} else {
-					check.softErrorf(atPos(pos), 0, "%s does not satisfy %s (missing method %s)", targ, tpar.bound, m.name)
-				}
-				break
-			}
-		}
-
-		// targ's underlying type must also be one of the interface types listed, if any
-		if iface.allTypes == nil {
-			continue // nothing to do
-		}
-
-		// If targ is itself a type parameter, each of its possible types, but at least one, must be in the
-		// list of iface types (i.e., the targ type list must be a non-empty subset of the iface types).
-		if targ := asTypeParam(targ); targ != nil {
-			targBound := targ.Bound()
-			if targBound.allTypes == nil {
-				check.softErrorf(atPos(pos), _Todo, "%s does not satisfy %s (%s has no type constraints)", targ, tpar.bound, targ)
-				break
-			}
-			for _, t := range unpackType(targBound.allTypes) {
-				if !iface.isSatisfiedBy(t) {
-					// TODO(gri) match this error message with the one below (or vice versa)
-					check.softErrorf(atPos(pos), 0, "%s does not satisfy %s (%s type constraint %s not found in %s)", targ, tpar.bound, targ, t, iface.allTypes)
-					break
-				}
-			}
-			break
-		}
-
-		// Otherwise, targ's type or underlying type must also be one of the interface types listed, if any.
-		if !iface.isSatisfiedBy(targ) {
-			check.softErrorf(atPos(pos), _Todo, "%s does not satisfy %s (%s or %s not found in %s)", targ, tpar.bound, targ, under(targ), iface.allTypes)
-			break
-		}
-	}
-
-	return check.subst(pos, typ, smap)
-}
-
 // subst returns the type typ with its type parameters tpars replaced by
 // the corresponding type arguments targs, recursively.
 // subst is functional in the sense that it doesn't modify the incoming
@@ -222,20 +63,33 @@ func (check *Checker) subst(pos token.Pos, typ Type, smap *substMap) Type {
 	switch t := typ.(type) {
 	case *Basic:
 		return typ // nothing to do
-	case *_TypeParam:
+	case *TypeParam:
 		return smap.lookup(t)
 	}
 
 	// general case
-	subst := subster{check, pos, make(map[Type]Type), smap}
+	var subst subster
+	subst.pos = pos
+	subst.smap = smap
+	if check != nil {
+		subst.check = check
+		subst.typMap = check.typMap
+	} else {
+		// If we don't have a *Checker and its global type map,
+		// use a local version. Besides avoiding duplicate work,
+		// the type map prevents infinite recursive substitution
+		// for recursive types (example: type T[P any] *T[P]).
+		subst.typMap = make(map[string]*Named)
+	}
+
 	return subst.typ(typ)
 }
 
 type subster struct {
-	check *Checker
-	pos   token.Pos
-	cache map[Type]Type
-	smap  *substMap
+	pos    token.Pos
+	smap   *substMap
+	check  *Checker // nil if called via Instantiate
+	typMap map[string]*Named
 }
 
 func (subst *subster) typ(typ Type) Type {
@@ -244,7 +98,7 @@ func (subst *subster) typ(typ Type) Type {
 		// Call typOrNil if it's possible that typ is nil.
 		panic("nil typ")
 
-	case *Basic, *bottom, *top:
+	case *Basic, *top:
 		// nothing to do
 
 	case *Array:
@@ -293,26 +147,23 @@ func (subst *subster) typ(typ Type) Type {
 			}
 		}
 
-	case *_Sum:
-		types, copied := subst.typeList(t.types)
+	case *Union:
+		terms, copied := subst.termList(t.terms)
 		if copied {
-			// Don't do it manually, with a Sum literal: the new
-			// types list may not be unique and NewSum may remove
-			// duplicates.
-			return _NewSum(types)
+			// TODO(gri) Remove duplicates that may have crept in after substitution
+			//           (unlikely but possible). This matters for the Identical
+			//           predicate on unions.
+			return &Union{terms}
 		}
 
 	case *Interface:
 		methods, mcopied := subst.funcList(t.methods)
-		types := t.types
-		if t.types != nil {
-			types = subst.typ(t.types)
-		}
 		embeddeds, ecopied := subst.typeList(t.embeddeds)
-		if mcopied || types != t.types || ecopied {
-			iface := &Interface{methods: methods, types: types, embeddeds: embeddeds}
-			subst.check.posMap[iface] = subst.check.posMap[t] // satisfy completeInterface requirement
-			subst.check.completeInterface(token.NoPos, iface)
+		if mcopied || ecopied {
+			iface := &Interface{methods: methods, embeddeds: embeddeds, complete: t.complete}
+			if subst.check == nil {
+				panic("internal error: cannot instantiate interfaces yet")
+			}
 			return iface
 		}
 
@@ -330,17 +181,19 @@ func (subst *subster) typ(typ Type) Type {
 		}
 
 	case *Named:
-		subst.check.indent++
-		defer func() {
-			subst.check.indent--
-		}()
-		dump := func(format string, args ...interface{}) {
-			if trace {
+		// dump is for debugging
+		dump := func(string, ...interface{}) {}
+		if subst.check != nil && trace {
+			subst.check.indent++
+			defer func() {
+				subst.check.indent--
+			}()
+			dump = func(format string, args ...interface{}) {
 				subst.check.trace(subst.pos, format, args...)
 			}
 		}
 
-		if t.tparams == nil {
+		if t.TParams().Len() == 0 {
 			dump(">>> %s is not parameterized", t)
 			return t // type is not parameterized
 		}
@@ -350,7 +203,7 @@ func (subst *subster) typ(typ Type) Type {
 		if len(t.targs) > 0 {
 			// already instantiated
 			dump(">>> %s already instantiated", t)
-			assert(len(t.targs) == len(t.tparams))
+			assert(len(t.targs) == t.TParams().Len())
 			// For each (existing) type argument targ, determine if it needs
 			// to be substituted; i.e., if it is or contains a type parameter
 			// that has a type argument for it.
@@ -360,7 +213,7 @@ func (subst *subster) typ(typ Type) Type {
 				if newTarg != targ {
 					dump(">>> substituted %d targ %s => %s", i, targ, newTarg)
 					if newTargs == nil {
-						newTargs = make([]Type, len(t.tparams))
+						newTargs = make([]Type, t.TParams().Len())
 						copy(newTargs, t.targs)
 					}
 					newTargs[i] = newTarg
@@ -381,34 +234,30 @@ func (subst *subster) typ(typ Type) Type {
 		// before creating a new named type, check if we have this one already
 		h := instantiatedHash(t, newTargs)
 		dump(">>> new type hash: %s", h)
-		if named, found := subst.check.typMap[h]; found {
+		if named, found := subst.typMap[h]; found {
 			dump(">>> found %s", named)
-			subst.cache[t] = named
 			return named
 		}
 
-		// create a new named type and populate caches to avoid endless recursion
+		// create a new named type and populate typMap to avoid endless recursion
 		tname := NewTypeName(subst.pos, t.obj.pkg, t.obj.name, nil)
-		named := subst.check.newNamed(tname, t.underlying, t.methods) // method signatures are updated lazily
-		named.tparams = t.tparams                                     // new type is still parameterized
+		named := subst.check.newNamed(tname, t, t.Underlying(), t.TParams(), t.methods) // method signatures are updated lazily
 		named.targs = newTargs
-		subst.check.typMap[h] = named
-		subst.cache[t] = named
+		subst.typMap[h] = named
+		t.expand() // must happen after typMap update to avoid infinite recursion
 
 		// do the substitution
 		dump(">>> subst %s with %s (new: %s)", t.underlying, subst.smap, newTargs)
-		named.underlying = subst.typOrNil(t.underlying)
-		named.orig = named.underlying // for cycle detection (Checker.validType)
+		named.underlying = subst.typOrNil(t.Underlying())
+		dump(">>> underlying: %v", named.underlying)
+		assert(named.underlying != nil)
+		named.fromRHS = named.underlying // for cycle detection (Checker.validType)
 
 		return named
 
-	case *_TypeParam:
+	case *TypeParam:
 		return subst.smap.lookup(t)
 
-	case *instance:
-		// TODO(gri) can we avoid the expansion here and just substitute the type parameters?
-		return subst.typ(t.expand())
-
 	default:
 		panic("unimplemented")
 	}
@@ -416,14 +265,17 @@ func (subst *subster) typ(typ Type) Type {
 	return typ
 }
 
-// TODO(gri) Eventually, this should be more sophisticated.
-//           It won't work correctly for locally declared types.
+var instanceHashing = 0
+
 func instantiatedHash(typ *Named, targs []Type) string {
+	assert(instanceHashing == 0)
+	instanceHashing++
 	var buf bytes.Buffer
 	writeTypeName(&buf, typ.obj, nil)
 	buf.WriteByte('[')
 	writeTypeList(&buf, targs, nil, nil)
 	buf.WriteByte(']')
+	instanceHashing--
 
 	// With respect to the represented type, whether a
 	// type is fully expanded or stored as instance
@@ -541,3 +393,21 @@ func (subst *subster) typeList(in []Type) (out []Type, copied bool) {
 	}
 	return
 }
+
+func (subst *subster) termList(in []*term) (out []*term, copied bool) {
+	out = in
+	for i, t := range in {
+		if u := subst.typ(t.typ); u != t.typ {
+			if !copied {
+				// first function that got substituted => allocate new out slice
+				// and copy all functions
+				new := make([]*term, len(in))
+				copy(new, out)
+				out = new
+				copied = true
+			}
+			out[i] = &term{t.tilde, u}
+		}
+	}
+	return
+}
diff --git a/src/go/types/testdata/check/builtins.go2 b/src/go/types/testdata/check/builtins.go2
index 3918d836b52..3881090603e 100644
--- a/src/go/types/testdata/check/builtins.go2
+++ b/src/go/types/testdata/check/builtins.go2
@@ -6,48 +6,231 @@
 
 package builtins
 
+import "unsafe"
+
+// close
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func _[T any](ch T) {
+	close(ch /* ERROR cannot close non-channel */)
+}
+
+func _[T C0](ch T) {
+	close(ch /* ERROR cannot close non-channel */)
+}
+
+func _[T C1](ch T) {
+	close(ch)
+}
+
+func _[T C2](ch T) {
+	close(ch /* ERROR cannot close receive-only channel */)
+}
+
+func _[T C3](ch T) {
+	close(ch)
+}
+
+func _[T C4](ch T) {
+	close(ch)
+}
+
+func _[T C5[X], X any](ch T) {
+	close(ch)
+}
+
+// delete
+
+type M0 interface{ int }
+type M1 interface{ map[string]int }
+type M2 interface { map[string]int | map[string]float64 }
+type M3 interface{ map[string]int | map[rune]int }
+type M4[K comparable, V any] interface{ map[K]V | map[rune]V }
+
+func _[T any](m T) {
+	delete(m /* ERROR not a map */, "foo")
+}
+
+func _[T M0](m T) {
+	delete(m /* ERROR not a map */, "foo")
+}
+
+func _[T M1](m T) {
+	delete(m, "foo")
+}
+
+func _[T M2](m T) {
+	delete(m, "foo")
+	delete(m, 0 /* ERROR cannot use .* as string */)
+}
+
+func _[T M3](m T) {
+	delete(m /* ERROR must have identical key types */, "foo")
+}
+
+func _[T M4[rune, V], V any](m T) {
+	delete(m, 'k')
+}
+
+func _[T M4[K, V], K comparable, V any](m T) {
+	delete(m /* ERROR must have identical key types */, "foo")
+}
+
+// make
+
 type Bmc interface {
-	type map[rune]string, chan int
+	~map[rune]string | ~chan int
 }
 
 type Bms interface {
-	type map[string]int, []int
+	~map[string]int | ~[]int
 }
 
 type Bcs interface {
-	type chan bool, []float64
+	~chan bool | ~[]float64
 }
 
 type Bss interface {
-	type []int, []string
+	~[]int | ~[]string
 }
 
-func _[T any] () {
-	_ = make(T /* ERROR invalid argument */ )
-	_ = make(T /* ERROR invalid argument */ , 10)
-	_ = make(T /* ERROR invalid argument */ , 10, 20)
+func _[T any]() {
+	_ = make(T /* ERROR invalid argument */)
+	_ = make(T /* ERROR invalid argument */, 10)
+	_ = make(T /* ERROR invalid argument */, 10, 20)
 }
 
-func _[T Bmc] () {
+func _[T Bmc]() {
 	_ = make(T)
 	_ = make(T, 10)
 	_ = make /* ERROR expects 1 or 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bms] () {
+func _[T Bms]() {
 	_ = make /* ERROR expects 2 arguments */ (T)
 	_ = make(T, 10)
 	_ = make /* ERROR expects 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bcs] () {
+func _[T Bcs]() {
 	_ = make /* ERROR expects 2 arguments */ (T)
 	_ = make(T, 10)
 	_ = make /* ERROR expects 2 arguments */ (T, 10, 20)
 }
 
-func _[T Bss] () {
+func _[T Bss]() {
 	_ = make /* ERROR expects 2 or 3 arguments */ (T)
 	_ = make(T, 10)
 	_ = make(T, 10, 20)
 }
+
+// unsafe.Alignof
+
+func _[T comparable]() {
+	var (
+		b int64
+		a [10]T
+		s struct{ f T }
+		p *T
+		l []T
+		f func(T)
+		i interface{ m() T }
+		c chan T
+		m map[T]T
+		t T
+	)
+
+	const bb = unsafe.Alignof(b)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Alignof(p)
+	assert(pp == 8)
+	const ll = unsafe.Alignof(l)
+	assert(ll == 8)
+	const ff = unsafe.Alignof(f)
+	assert(ff == 8)
+	const ii = unsafe.Alignof(i)
+	assert(ii == 8)
+	const cc = unsafe.Alignof(c)
+	assert(cc == 8)
+	const mm = unsafe.Alignof(m)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
+}
+
+// unsafe.Offsetof
+
+func _[T comparable]() {
+	var (
+		b struct{ _, f int64 }
+		a struct{ _, f [10]T }
+		s struct{ _, f struct{ f T } }
+		p struct{ _, f *T }
+		l struct{ _, f []T }
+		f struct{ _, f func(T) }
+		i struct{ _, f interface{ m() T } }
+		c struct{ _, f chan T }
+		m struct{ _, f map[T]T }
+		t struct{ _, f T }
+	)
+
+	const bb = unsafe.Offsetof(b.f)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Offsetof(p.f)
+	assert(pp == 8)
+	const ll = unsafe.Offsetof(l.f)
+	assert(ll == 24)
+	const ff = unsafe.Offsetof(f.f)
+	assert(ff == 8)
+	const ii = unsafe.Offsetof(i.f)
+	assert(ii == 16)
+	const cc = unsafe.Offsetof(c.f)
+	assert(cc == 8)
+	const mm = unsafe.Offsetof(m.f)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
+}
+
+// unsafe.Sizeof
+
+func _[T comparable]() {
+	var (
+		b int64
+		a [10]T
+		s struct{ f T }
+		p *T
+		l []T
+		f func(T)
+		i interface{ m() T }
+		c chan T
+		m map[T]T
+		t T
+	)
+
+	const bb = unsafe.Sizeof(b)
+	assert(bb == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(a)
+	const _ = unsafe /* ERROR not constant */ .Alignof(s)
+	const pp = unsafe.Sizeof(p)
+	assert(pp == 8)
+	const ll = unsafe.Sizeof(l)
+	assert(ll == 24)
+	const ff = unsafe.Sizeof(f)
+	assert(ff == 8)
+	const ii = unsafe.Sizeof(i)
+	assert(ii == 16)
+	const cc = unsafe.Sizeof(c)
+	assert(cc == 8)
+	const mm = unsafe.Sizeof(m)
+	assert(mm == 8)
+	const _ = unsafe /* ERROR not constant */ .Alignof(t)
+}
diff --git a/src/go/types/testdata/check/builtins.src b/src/go/types/testdata/check/builtins.src
index 37075289140..7fd6a4b0329 100644
--- a/src/go/types/testdata/check/builtins.src
+++ b/src/go/types/testdata/check/builtins.src
@@ -144,7 +144,7 @@ func close1() {
 	var r <-chan int
 	close() // ERROR not enough arguments
 	close(1, 2) // ERROR too many arguments
-	close(42 /* ERROR not a channel */)
+	close(42 /* ERROR cannot close non-channel */)
 	close(r /* ERROR receive-only channel */)
 	close(c)
 	_ = close /* ERROR used as value */ (c)
diff --git a/src/go/types/testdata/check/const0.src b/src/go/types/testdata/check/const0.src
index 5608b1549ba..3cffdf904c8 100644
--- a/src/go/types/testdata/check/const0.src
+++ b/src/go/types/testdata/check/const0.src
@@ -27,7 +27,7 @@ const (
 	ub1 = true
 	ub2 = 2 < 1
 	ub3 = ui1 == uf1
-	ub4 = true /* ERROR "cannot convert" */ == 0
+	ub4 = true /* ERROR "mismatched types untyped bool and untyped int" */ == 0
 
 	// integer values
 	ui0 = 0
diff --git a/src/go/types/testdata/check/cycles4.src b/src/go/types/testdata/check/cycles4.src
index 445babca68b..924aabf475f 100644
--- a/src/go/types/testdata/check/cycles4.src
+++ b/src/go/types/testdata/check/cycles4.src
@@ -4,6 +4,8 @@
 
 package p
 
+import "unsafe"
+
 // Check that all methods of T are collected before
 // determining the result type of m (which embeds
 // all methods of T).
@@ -13,7 +15,7 @@ type T interface {
 	E
 }
 
-var _ = T.m(nil).m().e()
+var _ int = T.m(nil).m().e()
 
 type E interface {
 	e() int
@@ -22,7 +24,7 @@ type E interface {
 // Check that unresolved forward chains are followed
 // (see also comment in resolver.go, checker.typeDecl).
 
-var _ = C.m(nil).m().e()
+var _ int = C.m(nil).m().e()
 
 type A B
 
@@ -108,3 +110,12 @@ type Element interface {
 type Event interface {
 	Target() Element
 }
+
+// Check that accessing an interface method too early doesn't lead
+// to follow-on errors due to an incorrectly computed type set.
+
+type T8 interface {
+	m() [unsafe.Sizeof(T8.m /* ERROR undefined */ )]int
+}
+
+var _ = T8.m // no error expected here
diff --git a/src/go/types/testdata/check/decls0.src b/src/go/types/testdata/check/decls0.src
index 5ad8f53f65a..1224e46377a 100644
--- a/src/go/types/testdata/check/decls0.src
+++ b/src/go/types/testdata/check/decls0.src
@@ -4,7 +4,7 @@
 
 // type declarations
 
-package decls0
+package go1_17 // don't permit non-interface elements in interfaces
 
 import "unsafe"
 
@@ -187,10 +187,10 @@ func f4() (x *f4 /* ERROR "not a type" */ ) { return }
 // TODO(#43215) this should be detected as a cycle error
 func f5([unsafe.Sizeof(f5)]int) {}
 
-func (S0) m1 (x S0 /* ERROR value .* is not a type */ .m1) {}
-func (S0) m2 (x *S0 /* ERROR value .* is not a type */ .m2) {}
-func (S0) m3 () (x S0 /* ERROR value .* is not a type */ .m3) { return }
-func (S0) m4 () (x *S0 /* ERROR value .* is not a type */ .m4) { return }
+func (S0) m1 (x S0 /* ERROR illegal cycle in method declaration */ .m1) {}
+func (S0) m2 (x *S0 /* ERROR illegal cycle in method declaration */ .m2) {}
+func (S0) m3 () (x S0 /* ERROR illegal cycle in method declaration */ .m3) { return }
+func (S0) m4 () (x *S0 /* ERROR illegal cycle in method declaration */ .m4) { return }
 
 // interfaces may not have any blank methods
 type BlankI interface {
diff --git a/src/go/types/testdata/check/decls1.src b/src/go/types/testdata/check/decls1.src
index f4d2eaba911..6fe349b0b2f 100644
--- a/src/go/types/testdata/check/decls1.src
+++ b/src/go/types/testdata/check/decls1.src
@@ -83,7 +83,7 @@ var (
 
 // Constant expression initializations
 var (
-	v1 = 1 /* ERROR "cannot convert" */ + "foo"
+	v1 = 1 /* ERROR "mismatched types untyped int and untyped string" */ + "foo"
 	v2 = c + 255
 	v3 = c + 256 /* ERROR "overflows" */
 	v4 = r + 2147483647
diff --git a/src/go/types/testdata/check/expr1.src b/src/go/types/testdata/check/expr1.src
index 4ead815158f..42b95fbb37b 100644
--- a/src/go/types/testdata/check/expr1.src
+++ b/src/go/types/testdata/check/expr1.src
@@ -111,10 +111,10 @@ type mystring string
 func _(x, y string, z mystring) {
 	x = x + "foo"
 	x = x /* ERROR not defined */ - "foo"
-	x = x + 1 // ERROR cannot convert
+	x = x /* ERROR mismatched types string and untyped int */ + 1
 	x = x + y
 	x = x /* ERROR not defined */ - y
-	x = x * 10 // ERROR cannot convert
+	x = x /* ERROR mismatched types string and untyped int */* 10
 }
 
 func f() (a, b int) { return }
diff --git a/src/go/types/testdata/check/expr2.src b/src/go/types/testdata/check/expr2.src
index 0c959e80119..f9726b5de53 100644
--- a/src/go/types/testdata/check/expr2.src
+++ b/src/go/types/testdata/check/expr2.src
@@ -10,7 +10,7 @@ func _bool() {
 	const t = true == true
 	const f = true == false
 	_ = t /* ERROR "cannot compare" */ < f
-	_ = 0 /* ERROR "cannot convert" */ == t
+	_ = 0 /* ERROR "mismatched types untyped int and untyped bool" */ == t
 	var b bool
 	var x, y float32
 	b = x < y
diff --git a/src/go/types/testdata/check/expr3.src b/src/go/types/testdata/check/expr3.src
index 0525a5a33ae..3ab367810f5 100644
--- a/src/go/types/testdata/check/expr3.src
+++ b/src/go/types/testdata/check/expr3.src
@@ -103,7 +103,7 @@ func indexes() {
 	var ok mybool
 	_, ok = m["bar"]
 	_ = ok
-	_ = m[0 /* ERROR "cannot use 0" */ ] + "foo" // ERROR "cannot convert"
+	_ = m/* ERROR "mismatched types int and untyped string" */[0 /* ERROR "cannot use 0" */ ] + "foo"
 
 	var t string
 	_ = t[- /* ERROR "negative" */ 1]
diff --git a/src/go/types/testdata/check/issues.go2 b/src/go/types/testdata/check/issues.go2
index 8994164eacf..6a1a10ad49b 100644
--- a/src/go/types/testdata/check/issues.go2
+++ b/src/go/types/testdata/check/issues.go2
@@ -24,22 +24,20 @@ func _() {
 	eql[io.Reader](nil, nil)
 }
 
-// If we have a receiver of pointer type (below: *T) we must ignore
-// the pointer in the implementation of the method lookup because
-// the type bound of T is an interface and pointer to interface types
-// have no methods and then the lookup would fail.
+// If we have a receiver of pointer to type parameter type (below: *T)
+// we don't have any methods, like for interfaces.
 type C[T any] interface {
     m()
 }
 
 // using type bound C
 func _[T C[T]](x *T) {
-	x.m()
+	x.m  /* ERROR x\.m undefined */ ()
 }
 
 // using an interface literal as bound
 func _[T interface{ m() }](x *T) {
-	x.m()
+	x.m  /* ERROR x\.m undefined */ ()
 }
 
 // In a generic function body all method calls will be pointer method calls.
@@ -64,15 +62,15 @@ func _() {
 // type with a type list constraint, all of the type argument's types in its
 // bound, but at least one (!), must be in the type list of the bound of the
 // corresponding parameterized type's type parameter.
-type T1[P interface{type uint}] struct{}
+type T1[P interface{~uint}] struct{}
 
 func _[P any]() {
-    _ = T1[P /* ERROR P has no type constraints */ ]{}
+    _ = T1[P /* ERROR P has no constraints */ ]{}
 }
 
 // This is the original (simplified) program causing the same issue.
 type Unsigned interface {
-	type uint
+	~uint
 }
 
 type T2[U Unsigned] struct {
@@ -83,8 +81,8 @@ func (u T2[U]) Add1() U {
     return u.s + 1
 }
 
-func NewT2[U any]() T2[U /* ERROR U has no type constraints */ ] {
-    return T2[U /* ERROR U has no type constraints */ ]{}
+func NewT2[U any]() T2[U /* ERROR U has no constraints */ ] {
+    return T2[U /* ERROR U has no constraints */ ]{}
 }
 
 func _() {
@@ -163,7 +161,7 @@ type inf2[T any] struct{ inf2 /* ERROR illegal cycle */ [T] }
 // predicate disjunction in the implementation was wrong because if a type list
 // contains both an integer and a floating-point type, the type parameter is
 // neither an integer or a floating-point number.
-func convert[T1, T2 interface{type int, uint, float32}](v T1) T2 {
+func convert[T1, T2 interface{~int | ~uint | ~float32}](v T1) T2 {
 	return T2(v)
 }
 
@@ -175,12 +173,12 @@ func _() {
 // both numeric, or both strings. The implementation had the same problem
 // with this check as the conversion issue above (issue #39623).
 
-func issue39623[T interface{type int, string}](x, y T) T {
+func issue39623[T interface{~int | ~string}](x, y T) T {
 	return x + y
 }
 
 // Simplified, from https://go2goplay.golang.org/p/efS6x6s-9NI:
-func Sum[T interface{type int, string}](s []T) (sum T) {
+func Sum[T interface{~int | ~string}](s []T) (sum T) {
 	for _, v := range s {
 		sum += v
 	}
@@ -189,19 +187,19 @@ func Sum[T interface{type int, string}](s []T) (sum T) {
 
 // Assignability of an unnamed pointer type to a type parameter that
 // has a matching underlying type.
-func _[T interface{}, PT interface{type *T}] (x T) PT {
+func _[T interface{}, PT interface{~*T}] (x T) PT {
     return &x
 }
 
 // Indexing of generic types containing type parameters in their type list:
-func at[T interface{ type []E }, E interface{}](x T, i int) E {
+func at[T interface{ ~[]E }, E interface{}](x T, i int) E {
         return x[i]
 }
 
 // A generic type inside a function acts like a named type. Its underlying
 // type is itself, its "operational type" is defined by the type list in
 // the tybe bound, if any.
-func _[T interface{type int}](x T) {
+func _[T interface{~int}](x T) {
 	type myint int
 	var _ int = int(x)
 	var _ T = 42
@@ -210,24 +208,24 @@ func _[T interface{type int}](x T) {
 
 // Indexing a generic type with an array type bound checks length.
 // (Example by mdempsky@.)
-func _[T interface { type [10]int }](x T) {
+func _[T interface { ~[10]int }](x T) {
 	_ = x[9] // ok
 	_ = x[20 /* ERROR out of bounds */ ]
 }
 
 // Pointer indirection of a generic type.
-func _[T interface{ type *int }](p T) int {
+func _[T interface{ ~*int }](p T) int {
 	return *p
 }
 
 // Channel sends and receives on generic types.
-func _[T interface{ type chan int }](ch T) int {
+func _[T interface{ ~chan int }](ch T) int {
 	ch <- 0
 	return <- ch
 }
 
 // Calling of a generic variable.
-func _[T interface{ type func() }](f T) {
+func _[T interface{ ~func() }](f T) {
 	f()
 	go f()
 }
@@ -239,9 +237,9 @@ func _[T interface{ type func() }](f T) {
 // type parameter that was substituted with a defined type.
 // Test case from an (originally) failing example.
 
-type sliceOf[E any] interface{ type []E }
+type sliceOf[E any] interface{ ~[]E }
 
-func append[T interface{}, S sliceOf[T], T2 interface{ type T }](s S, t ...T2) S
+func append[T interface{}, S sliceOf[T], T2 interface{}](s S, t ...T2) S
 
 var f           func()
 var cancelSlice []context.CancelFunc
diff --git a/src/go/types/testdata/check/issues.src b/src/go/types/testdata/check/issues.src
index e2ac06759ba..ef1737331d7 100644
--- a/src/go/types/testdata/check/issues.src
+++ b/src/go/types/testdata/check/issues.src
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package issues
+package go1_17 // don't permit non-interface elements in interfaces
 
 import (
 	"fmt"
-	syn "cmd/compile/internal/syntax"
+	syn "regexp/syntax"
 	t1 "text/template"
 	t2 "html/template"
 )
@@ -329,10 +329,10 @@ func (... /* ERROR can only use ... with final parameter */ TT) f()
 func issue28281g() (... /* ERROR can only use ... with final parameter */ TT)
 
 // Issue #26234: Make various field/method lookup errors easier to read by matching cmd/compile's output
-func issue26234a(f *syn.File) {
+func issue26234a(f *syn.Prog) {
 	// The error message below should refer to the actual package name (syntax)
 	// not the local package name (syn).
-	f.foo /* ERROR f.foo undefined \(type \*syntax.File has no field or method foo\) */
+	f.foo /* ERROR f\.foo undefined \(type \*syntax\.Prog has no field or method foo\) */
 }
 
 type T struct {
@@ -357,11 +357,11 @@ func issue35895() {
 	var _ T = 0 // ERROR cannot use 0 \(untyped int constant\) as T
 
 	// There is only one package with name syntax imported, only use the (global) package name in error messages.
-	var _ *syn.File = 0 // ERROR cannot use 0 \(untyped int constant\) as \*syntax.File
+	var _ *syn.Prog = 0 // ERROR cannot use 0 \(untyped int constant\) as \*syntax.Prog
 
 	// Because both t1 and t2 have the same global package name (template),
 	// qualify packages with full path name in this case.
-	var _ t1.Template = t2 /* ERROR cannot use .* \(value of type "html/template".Template\) as "text/template".Template */ .Template{}
+	var _ t1.Template = t2 /* ERROR cannot use .* \(value of type .html/template.\.Template\) as .text/template.\.Template */ .Template{}
 }
 
 func issue42989(s uint) {
diff --git a/src/go/types/testdata/check/linalg.go2 b/src/go/types/testdata/check/linalg.go2
index 0d27603a583..efc090a1d1f 100644
--- a/src/go/types/testdata/check/linalg.go2
+++ b/src/go/types/testdata/check/linalg.go2
@@ -9,10 +9,10 @@ import "math"
 // Numeric is type bound that matches any numeric type.
 // It would likely be in a constraints package in the standard library.
 type Numeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		complex64, complex128
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~complex64 | ~complex128
 }
 
 func DotProduct[T Numeric](s1, s2 []T) T {
@@ -42,14 +42,14 @@ func AbsDifference[T NumericAbs[T]](a, b T) T {
 
 // OrderedNumeric is a type bound that matches numeric types that support the < operator.
 type OrderedNumeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
 }
 
 // Complex is a type bound that matches the two complex types, which do not have a < operator.
 type Complex interface {
-	type complex64, complex128
+	~complex64 | ~complex128
 }
 
 // OrderedAbs is a helper type that defines an Abs method for
diff --git a/src/go/types/testdata/check/stmt0.src b/src/go/types/testdata/check/stmt0.src
index 76b6e70d63b..15df37703c1 100644
--- a/src/go/types/testdata/check/stmt0.src
+++ b/src/go/types/testdata/check/stmt0.src
@@ -49,18 +49,18 @@ func assignments1() {
 	b = true
 
 	i += 1
-	i += "foo" /* ERROR "cannot convert.*int" */
+	i /* ERROR "mismatched types int and untyped string" */+= "foo"
 
 	f -= 1
 	f /= 0
 	f = float32(0)/0 /* ERROR "division by zero" */
-	f -= "foo" /* ERROR "cannot convert.*float64" */
+	f /* ERROR "mismatched types float64 and untyped string" */-= "foo"
 
 	c *= 1
 	c /= 0
 
 	s += "bar"
-	s += 1 /* ERROR "cannot convert.*string" */
+	s /* ERROR "mismatched types string and untyped int" */+= 1
 
 	var u64 uint64
 	u64 += 1< 0 {
 		x0 = x[0]
@@ -210,5 +210,5 @@ func _() {
 func h[] /* ERROR empty type parameter list */ ()
 
 func _() {
-	h[] /* ERROR operand */ ()
+	h /* ERROR cannot index */ [] /* ERROR operand */ ()
 }
diff --git a/src/go/types/testdata/examples/inference.go2 b/src/go/types/testdata/examples/inference.go2
index b4f3369aa0c..1142e569b47 100644
--- a/src/go/types/testdata/examples/inference.go2
+++ b/src/go/types/testdata/examples/inference.go2
@@ -7,7 +7,7 @@
 package p
 
 type Ordered interface {
-	type int, float64, string
+	~int|~float64|~string
 }
 
 func min[T Ordered](x, y T) T
@@ -54,7 +54,7 @@ func _() {
 	mixed[int, string](1.1 /* ERROR cannot use 1.1 */ , "", false)
 }
 
-func related1[Slice interface{type []Elem}, Elem any](s Slice, e Elem)
+func related1[Slice interface{~[]Elem}, Elem any](s Slice, e Elem)
 
 func _() {
 	// related1 can be called with explicit instantiation.
@@ -78,7 +78,7 @@ func _() {
 	related1(si, "foo" /* ERROR cannot use "foo" */ )
 }
 
-func related2[Elem any, Slice interface{type []Elem}](e Elem, s Slice)
+func related2[Elem any, Slice interface{~[]Elem}](e Elem, s Slice)
 
 func _() {
 	// related2 can be called with explicit instantiation.
diff --git a/src/go/types/testdata/examples/methods.go2 b/src/go/types/testdata/examples/methods.go2
index 76c6539e1b7..4e87041e547 100644
--- a/src/go/types/testdata/examples/methods.go2
+++ b/src/go/types/testdata/examples/methods.go2
@@ -6,6 +6,8 @@
 
 package p
 
+import "unsafe"
+
 // Parameterized types may have methods.
 type T1[A any] struct{ a A }
 
@@ -94,3 +96,18 @@ func (_ T2[_, _, _]) _() int { return 42 }
 type T0 struct{}
 func (T0) _() {}
 func (T1[A]) _() {}
+
+// A generic receiver type may constrain its type parameter such
+// that it must be a pointer type. Such receiver types are not
+// permitted.
+type T3a[P interface{ ~int | ~string | ~float64 }] P
+
+func (T3a[_]) m() {} // this is ok
+
+type T3b[P interface{ ~unsafe.Pointer }] P
+
+func (T3b /* ERROR invalid receiver */ [_]) m() {}
+
+type T3c[P interface{ *int | *string }] P
+
+func (T3c /* ERROR invalid receiver */ [_]) m() {}
diff --git a/src/go/types/testdata/examples/operations.go2 b/src/go/types/testdata/examples/operations.go2
new file mode 100644
index 00000000000..18e4d6080c5
--- /dev/null
+++ b/src/go/types/testdata/examples/operations.go2
@@ -0,0 +1,29 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+// indirection
+
+func _[P any](p P) {
+        _ = *p // ERROR cannot indirect p
+}
+
+func _[P interface{ int }](p P) {
+        _ = *p // ERROR cannot indirect p
+}
+
+func _[P interface{ *int }](p P) {
+        _ = *p
+}
+
+func _[P interface{ *int | *string }](p P) {
+        _ = *p // ERROR must have identical base types
+}
+
+type intPtr *int
+
+func _[P interface{ *int | intPtr } ](p P) {
+        var _ int = *p
+}
diff --git a/src/go/types/testdata/examples/types.go2 b/src/go/types/testdata/examples/types.go2
index 59c8804ad27..a7544f79ea0 100644
--- a/src/go/types/testdata/examples/types.go2
+++ b/src/go/types/testdata/examples/types.go2
@@ -161,30 +161,40 @@ type _ struct {
 	* /* ERROR List redeclared */ List[int]
 }
 
+// Issue #45639: We don't allow this anymore. Keep this code
+//               in case we decide to revisit this decision.
+//
 // It's possible to declare local types whose underlying types
 // are type parameters. As with ordinary type definitions, the
 // types underlying properties are "inherited" but the methods
 // are not.
-func _[T interface{ m(); type int }]() {
-	type L T
-	var x L
+//func _[T interface{ m(); ~int }]() {
+//	type L T
+//	var x L
+//
+//	// m is not defined on L (it is not "inherited" from
+//	// its underlying type).
+//	x.m /* ERROR x.m undefined */ ()
+//
+//	// But the properties of T, such that as that it supports
+//	// the operations of the types given by its type bound,
+//	// are also the properties of L.
+//	x++
+//	_ = x - x
+//
+//	// On the other hand, if we define a local alias for T,
+//	// that alias stands for T as expected.
+//	type A = T
+//	var y A
+//	y.m()
+//	_ = y < 0
+//}
 
-	// m is not defined on L (it is not "inherited" from
-	// its underlying type).
-	x.m /* ERROR x.m undefined */ ()
-
-	// But the properties of T, such that as that it supports
-	// the operations of the types given by its type bound,
-	// are also the properties of L.
-	x++
-	_ = x - x
-
-	// On the other hand, if we define a local alias for T,
-	// that alias stands for T as expected.
-	type A = T
-	var y A
-	y.m()
-	_ = y < 0
+// It is not permitted to declare a local type whose underlying
+// type is a type parameters not declared by that type declaration.
+func _[T any]() {
+	type _ T         // ERROR cannot use function type parameter T as RHS in type declaration
+	type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
 }
 
 // As a special case, an explicit type argument may be omitted
@@ -238,11 +248,11 @@ func _[A Adder[A], B Adder[B], C Adder[A]]() {
 // The type of variables (incl. parameters and return values) cannot
 // be an interface with type constraints or be/embed comparable.
 type I interface {
-	type int
+	~int
 }
 
 var (
-	_ interface /* ERROR contains type constraints */ {type int}
+	_ interface /* ERROR contains type constraints */ {~int}
 	_ I /* ERROR contains type constraints */
 )
 
@@ -273,7 +283,7 @@ func _() {
 // (If a type list contains just a single const type, we could
 // allow it, but such type lists don't make much sense in the
 // first place.)
-func _[T interface { type int, float64 }]() {
+func _[T interface {~int|~float64}]() {
 	// not valid
 	const _ = T /* ERROR not constant */ (0)
 	const _ T /* ERROR invalid constant type T */ = 1
diff --git a/src/go/types/testdata/fixedbugs/issue28251.src b/src/go/types/testdata/fixedbugs/issue28251.src
index cd79e0e8b5d..ef5e61df47f 100644
--- a/src/go/types/testdata/fixedbugs/issue28251.src
+++ b/src/go/types/testdata/fixedbugs/issue28251.src
@@ -60,6 +60,6 @@ type (
         T11 = T
 )
 
-func (T9 /* ERROR invalid receiver \*\*T */ ) m9() {}
+func (T9 /* ERROR invalid receiver type \*\*T */ ) m9() {}
 func _() { (T{}).m9 /* ERROR has no field or method m9 */ () }
 func _() { (&T{}).m9 /* ERROR has no field or method m9 */ () }
diff --git a/src/go/types/testdata/fixedbugs/issue39634.go2 b/src/go/types/testdata/fixedbugs/issue39634.go2
index a13ed13ce5f..aec404e294b 100644
--- a/src/go/types/testdata/fixedbugs/issue39634.go2
+++ b/src/go/types/testdata/fixedbugs/issue39634.go2
@@ -31,13 +31,14 @@ type x7[A any] struct{ foo7 }
 func main7() { var _ foo7 = x7[int]{} }
 
 // crash 8
-type foo8[A any] interface { type A }
-func bar8[A foo8[A]](a A) {}
-func main8() {}
+// Embedding stand-alone type parameters is not permitted for now. Disabled.
+// type foo8[A any] interface { ~A }
+// func bar8[A foo8[A]](a A) {}
+// func main8() {}
 
 // crash 9
-type foo9[A any] interface { type foo9 /* ERROR interface contains type constraints */ [A] }
-func _() { var _ = new(foo9 /* ERROR interface contains type constraints */ [int]) }
+type foo9[A any] interface { foo9 /* ERROR illegal cycle */ [A] }
+func _() { var _ = new(foo9 /* ERROR illegal cycle */ [int]) }
 
 // crash 12
 var u /* ERROR cycle */ , i [func /* ERROR used as value */ /* ERROR used as value */ (u, c /* ERROR undeclared */ /* ERROR undeclared */ ) {}(0, len /* ERROR must be called */ /* ERROR must be called */ )]c /* ERROR undeclared */ /* ERROR undeclared */
diff --git a/src/go/types/testdata/fixedbugs/issue39680.go2 b/src/go/types/testdata/fixedbugs/issue39680.go2
index 9bc26f35461..e56bc354758 100644
--- a/src/go/types/testdata/fixedbugs/issue39680.go2
+++ b/src/go/types/testdata/fixedbugs/issue39680.go2
@@ -4,16 +4,19 @@
 
 package p
 
+// Embedding stand-alone type parameters is not permitted for now. Disabled.
+
+/*
 import "fmt"
 
 // Minimal test case.
-func _[T interface{type T}](x T) T{
+func _[T interface{~T}](x T) T{
 	return x
 }
 
 // Test case from issue.
 type constr[T any] interface {
-	type T
+	~T
 }
 
 func Print[T constr[T]](s []T) {
@@ -25,3 +28,4 @@ func Print[T constr[T]](s []T) {
 func f() {
 	Print([]string{"Hello, ", "playground\n"})
 }
+*/
diff --git a/src/go/types/testdata/fixedbugs/issue39693.go2 b/src/go/types/testdata/fixedbugs/issue39693.go2
index 316ab1982e8..ec7641902a1 100644
--- a/src/go/types/testdata/fixedbugs/issue39693.go2
+++ b/src/go/types/testdata/fixedbugs/issue39693.go2
@@ -4,11 +4,20 @@
 
 package p
 
-type Number interface {
-	int     /* ERROR int is not an interface */
-	float64 /* ERROR float64 is not an interface */
+type Number1 interface {
+	// embedding non-interface types is permitted
+	int
+	float64
 }
 
-func Add[T Number](a, b T) T {
+func Add[T Number1](a, b T) T {
 	return a /* ERROR not defined */ + b
 }
+
+type Number2 interface {
+	int|float64
+}
+
+func Add2[T Number2](a, b T) T {
+	return a + b
+}
diff --git a/src/go/types/testdata/fixedbugs/issue39699.go2 b/src/go/types/testdata/fixedbugs/issue39699.go2
index 75491e7e26f..72f83997c24 100644
--- a/src/go/types/testdata/fixedbugs/issue39699.go2
+++ b/src/go/types/testdata/fixedbugs/issue39699.go2
@@ -8,7 +8,7 @@ type T0 interface{
 }
 
 type T1 interface{
-	type int
+	~int
 }
 
 type T2 interface{
diff --git a/src/go/types/testdata/fixedbugs/issue39711.go2 b/src/go/types/testdata/fixedbugs/issue39711.go2
index df621a4c173..cf1f90545f6 100644
--- a/src/go/types/testdata/fixedbugs/issue39711.go2
+++ b/src/go/types/testdata/fixedbugs/issue39711.go2
@@ -7,5 +7,7 @@ package p
 // Do not report a duplicate type error for this type list.
 // (Check types after interfaces have been completed.)
 type _ interface {
-	type interface{ Error() string }, interface{ String() string }
+	// TODO(rfindley) Once we have full type sets we can enable this again.
+	// Fow now we don't permit interfaces in type lists.
+	// type interface{ Error() string }, interface{ String() string }
 }
diff --git a/src/go/types/testdata/fixedbugs/issue39723.go2 b/src/go/types/testdata/fixedbugs/issue39723.go2
index 55464e6b775..367b3f1360f 100644
--- a/src/go/types/testdata/fixedbugs/issue39723.go2
+++ b/src/go/types/testdata/fixedbugs/issue39723.go2
@@ -6,4 +6,4 @@ package p
 
 // A constraint must be an interface; it cannot
 // be a type parameter, for instance.
-func _[A interface{ type interface{} }, B A /* ERROR not an interface */ ]()
+func _[A interface{ ~int }, B A /* ERROR not an interface */ ]()
diff --git a/src/go/types/testdata/fixedbugs/issue39755.go2 b/src/go/types/testdata/fixedbugs/issue39755.go2
index b7ab68818e9..257b73a2fbe 100644
--- a/src/go/types/testdata/fixedbugs/issue39755.go2
+++ b/src/go/types/testdata/fixedbugs/issue39755.go2
@@ -4,14 +4,14 @@
 
 package p
 
-func _[T interface{type map[string]int}](x T) {
+func _[T interface{~map[string]int}](x T) {
 	_ = x == nil
 }
 
 // simplified test case from issue
 
 type PathParamsConstraint interface {
-        type map[string]string, []struct{key, value string}
+        ~map[string]string | ~[]struct{key, value string}
 }
 
 type PathParams[T PathParamsConstraint] struct {
diff --git a/src/go/types/testdata/fixedbugs/issue39938.go2 b/src/go/types/testdata/fixedbugs/issue39938.go2
index 76e7e369ca1..0da6e103fd1 100644
--- a/src/go/types/testdata/fixedbugs/issue39938.go2
+++ b/src/go/types/testdata/fixedbugs/issue39938.go2
@@ -8,8 +8,8 @@ package p
 
 type E0[P any] P
 type E1[P any] *P
-type E2[P any] struct{ P }
-type E3[P any] struct{ *P }
+type E2[P any] struct{ _ P }
+type E3[P any] struct{ _ *P }
 
 type T0 /* ERROR illegal cycle */ struct {
         _ E0[T0]
diff --git a/src/go/types/testdata/fixedbugs/issue39948.go2 b/src/go/types/testdata/fixedbugs/issue39948.go2
index c2b460902cc..e38e57268d6 100644
--- a/src/go/types/testdata/fixedbugs/issue39948.go2
+++ b/src/go/types/testdata/fixedbugs/issue39948.go2
@@ -5,5 +5,5 @@
 package p
 
 type T[P any] interface{
-	P // ERROR P is a type parameter, not an interface
+	P // ERROR cannot embed a type parameter
 }
diff --git a/src/go/types/testdata/fixedbugs/issue40301.go2 b/src/go/types/testdata/fixedbugs/issue40301.go2
index 5d97855f8a1..c78f9a1fa04 100644
--- a/src/go/types/testdata/fixedbugs/issue40301.go2
+++ b/src/go/types/testdata/fixedbugs/issue40301.go2
@@ -7,6 +7,6 @@ package p
 import "unsafe"
 
 func _[T any](x T) {
-	_ = unsafe /* ERROR undefined */ .Alignof(x)
-	_ = unsafe /* ERROR undefined */ .Sizeof(x)
+	_ = unsafe.Alignof(x)
+	_ = unsafe.Sizeof(x)
 }
diff --git a/src/go/types/testdata/fixedbugs/issue40789.go2 b/src/go/types/testdata/fixedbugs/issue40789.go2
new file mode 100644
index 00000000000..9eea4ad60a6
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue40789.go2
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+func main() {
+	m := map[string]int{
+		"a": 6,
+		"b": 7,
+	}
+	fmt.Println(copyMap[map[string]int, string, int](m))
+}
+
+type Map[K comparable, V any] interface {
+	map[K] V
+}
+
+func copyMap[M Map[K, V], K comparable, V any](m M) M {
+	m1 := make(M)
+	for k, v := range m {
+		m1[k] = v
+	}
+	return m1
+}
+
+// simpler test case from the same issue
+
+type A[X comparable] interface {
+	[]X
+}
+
+func f[B A[X], X comparable]() B {
+	return nil
+}
diff --git a/src/go/types/testdata/fixedbugs/issue41124.go2 b/src/go/types/testdata/fixedbugs/issue41124.go2
index 61f766bcbd7..ab535049dd7 100644
--- a/src/go/types/testdata/fixedbugs/issue41124.go2
+++ b/src/go/types/testdata/fixedbugs/issue41124.go2
@@ -7,7 +7,7 @@ package p
 // Test case from issue.
 
 type Nat interface {
-	type Zero, Succ
+	Zero|Succ
 }
 
 type Zero struct{}
@@ -22,7 +22,7 @@ type I1 interface {
 }
 
 type I2 interface {
-	type int
+	~int
 }
 
 type I3 interface {
diff --git a/src/go/types/testdata/fixedbugs/issue42758.go2 b/src/go/types/testdata/fixedbugs/issue42758.go2
index 698cb8a16ba..bf0031f5d24 100644
--- a/src/go/types/testdata/fixedbugs/issue42758.go2
+++ b/src/go/types/testdata/fixedbugs/issue42758.go2
@@ -17,7 +17,7 @@ func _[T any](x interface{}){
 }
 
 type constraint interface {
-	type int
+	~int
 }
 
 func _[T constraint](x interface{}){
diff --git a/src/go/types/testdata/fixedbugs/issue43671.go2 b/src/go/types/testdata/fixedbugs/issue43671.go2
new file mode 100644
index 00000000000..6cc3801cc96
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue43671.go2
@@ -0,0 +1,58 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | <-chan T }
+
+func _[T any](ch T) {
+	<-ch // ERROR cannot receive from non-channel
+}
+
+func _[T C0](ch T) {
+	<-ch // ERROR cannot receive from non-channel
+}
+
+func _[T C1](ch T) {
+	<-ch
+}
+
+func _[T C2](ch T) {
+	<-ch
+}
+
+func _[T C3](ch T) {
+	<-ch // ERROR channels of ch .* must have the same element type
+}
+
+func _[T C4](ch T) {
+	<-ch // ERROR cannot receive from send-only channel
+}
+
+func _[T C5[X], X any](ch T, x X) {
+	x = <-ch
+}
+
+// test case from issue, slightly modified
+type RecvChan[T any] interface {
+	~chan T | ~<-chan T
+}
+
+func _[T any, C RecvChan[T]](ch C) T {
+	return <-ch
+}
+
+func f[T any, C interface{ chan T }](ch C) T {
+	return <-ch
+}
+
+func _(ch chan int) {
+	var x int = f(ch) // test constraint type inference for this case
+	_ = x
+}
diff --git a/src/go/types/testdata/fixedbugs/issue45548.go2 b/src/go/types/testdata/fixedbugs/issue45548.go2
index b1e42497e85..b8ba0ad4a70 100644
--- a/src/go/types/testdata/fixedbugs/issue45548.go2
+++ b/src/go/types/testdata/fixedbugs/issue45548.go2
@@ -4,7 +4,7 @@
 
 package p
 
-func f[F interface{type *Q}, G interface{type *R}, Q, R any](q Q, r R) {}
+func f[F interface{~*Q}, G interface{~*R}, Q, R any](q Q, r R) {}
 
 func _() {
 	f[*float64, *int](1, 2)
diff --git a/src/go/types/testdata/fixedbugs/issue45635.go2 b/src/go/types/testdata/fixedbugs/issue45635.go2
index 3e2cceca2d4..fc50797b17c 100644
--- a/src/go/types/testdata/fixedbugs/issue45635.go2
+++ b/src/go/types/testdata/fixedbugs/issue45635.go2
@@ -10,10 +10,10 @@ func main() {
 
 type N[T any] struct{}
 
-var _ N /* ERROR "0 arguments but 1 type parameters" */ []
+var _ N [] // ERROR expected type argument list
 
 type I interface {
-	type map[int]int, []int
+	~[]int
 }
 
 func _[T I](i, j int) {
@@ -27,6 +27,5 @@ func _[T I](i, j int) {
 	_ = s[i, j /* ERROR "more than one index" */ ]
 
 	var t T
-	// TODO(rFindley) Fix the duplicate error below.
-	_ = t[i, j /* ERROR "more than one index" */ /* ERROR "more than one index" */ ]
+	_ = t[i, j /* ERROR "more than one index" */ ]
 }
diff --git a/src/go/types/testdata/fixedbugs/issue45639.go2 b/src/go/types/testdata/fixedbugs/issue45639.go2
new file mode 100644
index 00000000000..441fb4cb346
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue45639.go2
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package P
+
+// It is not permitted to declare a local type whose underlying
+// type is a type parameters not declared by that type declaration.
+func _[T any]() {
+	type _ T         // ERROR cannot use function type parameter T as RHS in type declaration
+	type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
+}
diff --git a/src/go/types/testdata/fixedbugs/issue45985.go2 b/src/go/types/testdata/fixedbugs/issue45985.go2
index 550b9c67127..6e42dbb6339 100644
--- a/src/go/types/testdata/fixedbugs/issue45985.go2
+++ b/src/go/types/testdata/fixedbugs/issue45985.go2
@@ -5,7 +5,7 @@
 package issue45985
 
 // TODO(rFindley): this error should be on app[int] below.
-func app[S /* ERROR "type S = S does not match" */ interface{ type []T }, T any](s S, e T) S {
+func app[S /* ERROR "type S = S does not match" */ interface{ ~[]T }, T any](s S, e T) S {
     return append(s, e)
 }
 
diff --git a/src/go/types/testdata/fixedbugs/issue46090.go2 b/src/go/types/testdata/fixedbugs/issue46090.go2
new file mode 100644
index 00000000000..81b31974c8d
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue46090.go2
@@ -0,0 +1,9 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The predeclared type comparable is not visible before Go 1.18.
+
+package go1_17
+
+type _ comparable // ERROR undeclared
diff --git a/src/go/types/testdata/fixedbugs/issue46275.go2 b/src/go/types/testdata/fixedbugs/issue46275.go2
new file mode 100644
index 00000000000..0ebde31c8e9
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue46275.go2
@@ -0,0 +1,27 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue46275
+
+type N[T any] struct {
+        *N[T]
+        t T
+}
+
+func (n *N[T]) Elem() T {
+        return n.t
+}
+
+type I interface {
+        Elem() string
+}
+
+func _() {
+        var n1 *N[string]
+        var _ I = n1
+        type NS N[string]
+        var n2 *NS
+        var _ I = n2
+}
+
diff --git a/src/go/types/testdata/fixedbugs/issue46403.src b/src/go/types/testdata/fixedbugs/issue46403.src
new file mode 100644
index 00000000000..9d475222adb
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue46403.src
@@ -0,0 +1,11 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue46403
+
+func _() {
+	// a should be used, despite the parser error below.
+	var a []int
+	var _ = a[] // ERROR expected operand
+}
diff --git a/src/go/types/testdata/fixedbugs/issue46404.go1 b/src/go/types/testdata/fixedbugs/issue46404.go1
new file mode 100644
index 00000000000..db604bc1ac3
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue46404.go1
@@ -0,0 +1,8 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue46404
+
+// Check that we don't type check t[_] as an instantiation.
+type t [t /* ERROR not a type */ [_]]_ // ERROR cannot use
diff --git a/src/go/types/testdata/fixedbugs/issue47031.go2 b/src/go/types/testdata/fixedbugs/issue47031.go2
new file mode 100644
index 00000000000..b184f9b5b7d
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue47031.go2
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type Mer interface { M() }
+
+func F[T Mer](p *T) {
+	p.M /* ERROR p\.M undefined */ ()
+}
+
+type MyMer int
+
+func (MyMer) M() {}
+
+func _() {
+	F(new(MyMer))
+	F[Mer](nil)
+}
diff --git a/src/go/types/testdata/fixedbugs/issue47115.go2 b/src/go/types/testdata/fixedbugs/issue47115.go2
new file mode 100644
index 00000000000..6694219b549
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue47115.go2
@@ -0,0 +1,40 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func _[T any](ch T) {
+	ch <- /* ERROR cannot send to non-channel */ 0
+}
+
+func _[T C0](ch T) {
+	ch <- /* ERROR cannot send to non-channel */ 0
+}
+
+func _[T C1](ch T) {
+	ch <- 0
+}
+
+func _[T C2](ch T) {
+	ch  <-/* ERROR cannot send to receive-only channel */ 0
+}
+
+func _[T C3](ch T) {
+	ch <- /* ERROR channels of ch .* must have the same element type */ 0
+}
+
+func _[T C4](ch T) {
+	ch <- 0
+}
+
+func _[T C5[X], X any](ch T, x X) {
+	ch <- x
+}
diff --git a/src/go/types/testdata/fixedbugs/issue47127.go2 b/src/go/types/testdata/fixedbugs/issue47127.go2
new file mode 100644
index 00000000000..387c946957c
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue47127.go2
@@ -0,0 +1,37 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Embedding of stand-alone type parameters is not permitted.
+
+package p
+
+type (
+        _[P any] interface{ *P | []P | chan P | map[string]P }
+        _[P any] interface{ P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+        _[P any] interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+)
+
+func _[P any]() {
+        type (
+                _[P any] interface{ *P | []P | chan P | map[string]P }
+                _[P any] interface{ P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+                _[P any] interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+
+                _ interface{ *P | []P | chan P | map[string]P }
+                _ interface{ P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ ~P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ int | P /* ERROR "cannot embed a type parameter" */ }
+                _ interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }
+        )
+}
+
+func _[P any, Q interface{ *P | []P | chan P | map[string]P }]()
+func _[P any, Q interface{ P /* ERROR "cannot embed a type parameter" */ }]()
+func _[P any, Q interface{ ~P /* ERROR "cannot embed a type parameter" */ }]()
+func _[P any, Q interface{ int | P /* ERROR "cannot embed a type parameter" */ }]()
+func _[P any, Q interface{ int | ~P /* ERROR "cannot embed a type parameter" */ }]()
diff --git a/src/go/types/testdata/fixedbugs/issue47411.go2 b/src/go/types/testdata/fixedbugs/issue47411.go2
new file mode 100644
index 00000000000..7326205863f
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue47411.go2
@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func f[_ comparable]()
+func g[_ interface{interface{comparable; ~int|~string}}]()
+
+func _[P comparable,
+        Q interface{ comparable; ~int|~string },
+        R any,                               // not comparable
+        S interface{ comparable; ~func() },  // not comparable
+]() {
+        _ = f[int]
+        _ = f[P]
+        _ = f[Q]
+        _ = f[func /* ERROR does not satisfy comparable */ ()]
+        _ = f[R /* ERROR R has no constraints */ ]
+
+        _ = g[int]
+        _ = g[P /* ERROR P has no type constraints */ ]
+        _ = g[Q]
+        _ = g[func /* ERROR does not satisfy comparable */()]
+        _ = g[R /* ERROR R has no constraints */ ]
+}
diff --git a/src/go/types/testdata/manual.go2 b/src/go/types/testdata/manual.go2
new file mode 100644
index 00000000000..25e6f22f94b
--- /dev/null
+++ b/src/go/types/testdata/manual.go2
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is tested when running "go test -run Manual"
+// without source arguments. Use for one-off debugging.
+
+package p
+
diff --git a/src/go/types/tuple.go b/src/go/types/tuple.go
new file mode 100644
index 00000000000..16d28bc9a6f
--- /dev/null
+++ b/src/go/types/tuple.go
@@ -0,0 +1,36 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple.
+// Tuples are used as components of signatures and to represent the type of multiple
+// assignments; they are not first class types of Go.
+type Tuple struct {
+	vars []*Var
+}
+
+// NewTuple returns a new tuple for the given variables.
+func NewTuple(x ...*Var) *Tuple {
+	if len(x) > 0 {
+		return &Tuple{vars: x}
+	}
+	// TODO(gri) Don't represent empty tuples with a (*Tuple)(nil) pointer;
+	//           it's too subtle and causes problems.
+	return nil
+}
+
+// Len returns the number variables of tuple t.
+func (t *Tuple) Len() int {
+	if t != nil {
+		return len(t.vars)
+	}
+	return 0
+}
+
+// At returns the i'th variable of tuple t.
+func (t *Tuple) At(i int) *Var { return t.vars[i] }
+
+func (t *Tuple) Underlying() Type { return t }
+func (t *Tuple) String() string   { return TypeString(t, nil) }
diff --git a/src/go/types/type.go b/src/go/types/type.go
index 3303cfc0774..5819dd290ca 100644
--- a/src/go/types/type.go
+++ b/src/go/types/type.go
@@ -4,12 +4,6 @@
 
 package types
 
-import (
-	"fmt"
-	"go/token"
-	"sync/atomic"
-)
-
 // A Type represents a type of Go.
 // All types implement the Type interface.
 type Type interface {
@@ -22,740 +16,31 @@ type Type interface {
 	String() string
 }
 
-// BasicKind describes the kind of basic type.
-type BasicKind int
+// top represents the top of the type lattice.
+// It is the underlying type of a type parameter that
+// can be satisfied by any type (ignoring methods),
+// because its type constraint contains no restrictions
+// besides methods.
+type top struct{}
 
-const (
-	Invalid BasicKind = iota // type is invalid
+// theTop is the singleton top type.
+var theTop = &top{}
 
-	// predeclared types
-	Bool
-	Int
-	Int8
-	Int16
-	Int32
-	Int64
-	Uint
-	Uint8
-	Uint16
-	Uint32
-	Uint64
-	Uintptr
-	Float32
-	Float64
-	Complex64
-	Complex128
-	String
-	UnsafePointer
+func (t *top) Underlying() Type { return t }
+func (t *top) String() string   { return TypeString(t, nil) }
 
-	// types for untyped values
-	UntypedBool
-	UntypedInt
-	UntypedRune
-	UntypedFloat
-	UntypedComplex
-	UntypedString
-	UntypedNil
-
-	// aliases
-	Byte = Uint8
-	Rune = Int32
-)
-
-// BasicInfo is a set of flags describing properties of a basic type.
-type BasicInfo int
-
-// Properties of basic types.
-const (
-	IsBoolean BasicInfo = 1 << iota
-	IsInteger
-	IsUnsigned
-	IsFloat
-	IsComplex
-	IsString
-	IsUntyped
-
-	IsOrdered   = IsInteger | IsFloat | IsString
-	IsNumeric   = IsInteger | IsFloat | IsComplex
-	IsConstType = IsBoolean | IsNumeric | IsString
-)
-
-// A Basic represents a basic type.
-type Basic struct {
-	kind BasicKind
-	info BasicInfo
-	name string
-}
-
-// Kind returns the kind of basic type b.
-func (b *Basic) Kind() BasicKind { return b.kind }
-
-// Info returns information about properties of basic type b.
-func (b *Basic) Info() BasicInfo { return b.info }
-
-// Name returns the name of basic type b.
-func (b *Basic) Name() string { return b.name }
-
-// An Array represents an array type.
-type Array struct {
-	len  int64
-	elem Type
-}
-
-// NewArray returns a new array type for the given element type and length.
-// A negative length indicates an unknown length.
-func NewArray(elem Type, len int64) *Array { return &Array{len: len, elem: elem} }
-
-// Len returns the length of array a.
-// A negative result indicates an unknown length.
-func (a *Array) Len() int64 { return a.len }
-
-// Elem returns element type of array a.
-func (a *Array) Elem() Type { return a.elem }
-
-// A Slice represents a slice type.
-type Slice struct {
-	elem Type
-}
-
-// NewSlice returns a new slice type for the given element type.
-func NewSlice(elem Type) *Slice { return &Slice{elem: elem} }
-
-// Elem returns the element type of slice s.
-func (s *Slice) Elem() Type { return s.elem }
-
-// A Struct represents a struct type.
-type Struct struct {
-	fields []*Var
-	tags   []string // field tags; nil if there are no tags
-}
-
-// NewStruct returns a new struct with the given fields and corresponding field tags.
-// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be
-// only as long as required to hold the tag with the largest index i. Consequently,
-// if no field has a tag, tags may be nil.
-func NewStruct(fields []*Var, tags []string) *Struct {
-	var fset objset
-	for _, f := range fields {
-		if f.name != "_" && fset.insert(f) != nil {
-			panic("multiple fields with the same name")
-		}
+// under returns the true expanded underlying type.
+// If it doesn't exist, the result is Typ[Invalid].
+// under must only be called when a type is known
+// to be fully set up.
+func under(t Type) Type {
+	// TODO(gri) is this correct for *Union?
+	if n := asNamed(t); n != nil {
+		return n.under()
 	}
-	if len(tags) > len(fields) {
-		panic("more tags than fields")
-	}
-	return &Struct{fields: fields, tags: tags}
-}
-
-// NumFields returns the number of fields in the struct (including blank and embedded fields).
-func (s *Struct) NumFields() int { return len(s.fields) }
-
-// Field returns the i'th field for 0 <= i < NumFields().
-func (s *Struct) Field(i int) *Var { return s.fields[i] }
-
-// Tag returns the i'th field tag for 0 <= i < NumFields().
-func (s *Struct) Tag(i int) string {
-	if i < len(s.tags) {
-		return s.tags[i]
-	}
-	return ""
-}
-
-// A Pointer represents a pointer type.
-type Pointer struct {
-	base Type // element type
-}
-
-// NewPointer returns a new pointer type for the given element (base) type.
-func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} }
-
-// Elem returns the element type for the given pointer p.
-func (p *Pointer) Elem() Type { return p.base }
-
-// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple.
-// Tuples are used as components of signatures and to represent the type of multiple
-// assignments; they are not first class types of Go.
-type Tuple struct {
-	vars []*Var
-}
-
-// NewTuple returns a new tuple for the given variables.
-func NewTuple(x ...*Var) *Tuple {
-	if len(x) > 0 {
-		return &Tuple{vars: x}
-	}
-	// TODO(gri) Don't represent empty tuples with a (*Tuple)(nil) pointer;
-	//           it's too subtle and causes problems.
-	return nil
-}
-
-// Len returns the number variables of tuple t.
-func (t *Tuple) Len() int {
-	if t != nil {
-		return len(t.vars)
-	}
-	return 0
-}
-
-// At returns the i'th variable of tuple t.
-func (t *Tuple) At(i int) *Var { return t.vars[i] }
-
-// A Signature represents a (non-builtin) function or method type.
-// The receiver is ignored when comparing signatures for identity.
-type Signature struct {
-	// We need to keep the scope in Signature (rather than passing it around
-	// and store it in the Func Object) because when type-checking a function
-	// literal we call the general type checker which returns a general Type.
-	// We then unpack the *Signature and use the scope for the literal body.
-	rparams  []*TypeName // receiver type parameters from left to right, or nil
-	tparams  []*TypeName // type parameters from left to right, or nil
-	scope    *Scope      // function scope, present for package-local signatures
-	recv     *Var        // nil if not a method
-	params   *Tuple      // (incoming) parameters from left to right; or nil
-	results  *Tuple      // (outgoing) results from left to right; or nil
-	variadic bool        // true if the last parameter's type is of the form ...T (or string, for append built-in only)
-}
-
-// NewSignature returns a new function type for the given receiver, parameters,
-// and results, either of which may be nil. If variadic is set, the function
-// is variadic, it must have at least one parameter, and the last parameter
-// must be of unnamed slice type.
-func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature {
-	if variadic {
-		n := params.Len()
-		if n == 0 {
-			panic("types.NewSignature: variadic function must have at least one parameter")
-		}
-		if _, ok := params.At(n - 1).typ.(*Slice); !ok {
-			panic("types.NewSignature: variadic parameter must be of unnamed slice type")
-		}
-	}
-	return &Signature{recv: recv, params: params, results: results, variadic: variadic}
-}
-
-// Recv returns the receiver of signature s (if a method), or nil if a
-// function. It is ignored when comparing signatures for identity.
-//
-// For an abstract method, Recv returns the enclosing interface either
-// as a *Named or an *Interface. Due to embedding, an interface may
-// contain methods whose receiver type is a different interface.
-func (s *Signature) Recv() *Var { return s.recv }
-
-// _TParams returns the type parameters of signature s, or nil.
-func (s *Signature) _TParams() []*TypeName { return s.tparams }
-
-// _SetTParams sets the type parameters of signature s.
-func (s *Signature) _SetTParams(tparams []*TypeName) { s.tparams = tparams }
-
-// Params returns the parameters of signature s, or nil.
-func (s *Signature) Params() *Tuple { return s.params }
-
-// Results returns the results of signature s, or nil.
-func (s *Signature) Results() *Tuple { return s.results }
-
-// Variadic reports whether the signature s is variadic.
-func (s *Signature) Variadic() bool { return s.variadic }
-
-// A _Sum represents a set of possible types.
-// Sums are currently used to represent type lists of interfaces
-// and thus the underlying types of type parameters; they are not
-// first class types of Go.
-type _Sum struct {
-	types []Type // types are unique
-}
-
-// _NewSum returns a new Sum type consisting of the provided
-// types if there are more than one. If there is exactly one
-// type, it returns that type. If the list of types is empty
-// the result is nil.
-func _NewSum(types []Type) Type {
-	if len(types) == 0 {
-		return nil
-	}
-
-	// What should happen if types contains a sum type?
-	// Do we flatten the types list? For now we check
-	// and panic. This should not be possible for the
-	// current use case of type lists.
-	// TODO(gri) Come up with the rules for sum types.
-	for _, t := range types {
-		if _, ok := t.(*_Sum); ok {
-			panic("sum type contains sum type - unimplemented")
-		}
-	}
-
-	if len(types) == 1 {
-		return types[0]
-	}
-	return &_Sum{types: types}
-}
-
-// is reports whether all types in t satisfy pred.
-func (s *_Sum) is(pred func(Type) bool) bool {
-	if s == nil {
-		return false
-	}
-	for _, t := range s.types {
-		if !pred(t) {
-			return false
-		}
-	}
-	return true
-}
-
-// An Interface represents an interface type.
-type Interface struct {
-	methods   []*Func // ordered list of explicitly declared methods
-	types     Type    // (possibly a Sum) type declared with a type list (TODO(gri) need better field name)
-	embeddeds []Type  // ordered list of explicitly embedded types
-
-	allMethods []*Func // ordered list of methods declared with or embedded in this interface (TODO(gri): replace with mset)
-	allTypes   Type    // intersection of all embedded and locally declared types  (TODO(gri) need better field name)
-
-	obj Object // type declaration defining this interface; or nil (for better error messages)
-}
-
-// unpack unpacks a type into a list of types.
-// TODO(gri) Try to eliminate the need for this function.
-func unpackType(typ Type) []Type {
-	if typ == nil {
-		return nil
-	}
-	if sum := asSum(typ); sum != nil {
-		return sum.types
-	}
-	return []Type{typ}
-}
-
-// is reports whether interface t represents types that all satisfy pred.
-func (t *Interface) is(pred func(Type) bool) bool {
-	if t.allTypes == nil {
-		return false // we must have at least one type! (was bug)
-	}
-	for _, t := range unpackType(t.allTypes) {
-		if !pred(t) {
-			return false
-		}
-	}
-	return true
-}
-
-// emptyInterface represents the empty (completed) interface
-var emptyInterface = Interface{allMethods: markComplete}
-
-// markComplete is used to mark an empty interface as completely
-// set up by setting the allMethods field to a non-nil empty slice.
-var markComplete = make([]*Func, 0)
-
-// NewInterface returns a new (incomplete) interface for the given methods and embedded types.
-// Each embedded type must have an underlying type of interface type.
-// NewInterface takes ownership of the provided methods and may modify their types by setting
-// missing receivers. To compute the method set of the interface, Complete must be called.
-//
-// Deprecated: Use NewInterfaceType instead which allows any (even non-defined) interface types
-// to be embedded. This is necessary for interfaces that embed alias type names referring to
-// non-defined (literal) interface types.
-func NewInterface(methods []*Func, embeddeds []*Named) *Interface {
-	tnames := make([]Type, len(embeddeds))
-	for i, t := range embeddeds {
-		tnames[i] = t
-	}
-	return NewInterfaceType(methods, tnames)
-}
-
-// NewInterfaceType returns a new (incomplete) interface for the given methods and embedded types.
-// Each embedded type must have an underlying type of interface type (this property is not
-// verified for defined types, which may be in the process of being set up and which don't
-// have a valid underlying type yet).
-// NewInterfaceType takes ownership of the provided methods and may modify their types by setting
-// missing receivers. To compute the method set of the interface, Complete must be called.
-func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
-	if len(methods) == 0 && len(embeddeds) == 0 {
-		return &emptyInterface
-	}
-
-	// set method receivers if necessary
-	typ := new(Interface)
-	for _, m := range methods {
-		if sig := m.typ.(*Signature); sig.recv == nil {
-			sig.recv = NewVar(m.pos, m.pkg, "", typ)
-		}
-	}
-
-	// All embedded types should be interfaces; however, defined types
-	// may not yet be fully resolved. Only verify that non-defined types
-	// are interfaces. This matches the behavior of the code before the
-	// fix for #25301 (issue #25596).
-	for _, t := range embeddeds {
-		if _, ok := t.(*Named); !ok && !IsInterface(t) {
-			panic("embedded type is not an interface")
-		}
-	}
-
-	// sort for API stability
-	sortMethods(methods)
-	sortTypes(embeddeds)
-
-	typ.methods = methods
-	typ.embeddeds = embeddeds
-	return typ
-}
-
-// NumExplicitMethods returns the number of explicitly declared methods of interface t.
-func (t *Interface) NumExplicitMethods() int { return len(t.methods) }
-
-// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods().
-// The methods are ordered by their unique Id.
-func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] }
-
-// NumEmbeddeds returns the number of embedded types in interface t.
-func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) }
-
-// Embedded returns the i'th embedded defined (*Named) type of interface t for 0 <= i < t.NumEmbeddeds().
-// The result is nil if the i'th embedded type is not a defined type.
-//
-// Deprecated: Use EmbeddedType which is not restricted to defined (*Named) types.
-func (t *Interface) Embedded(i int) *Named { tname, _ := t.embeddeds[i].(*Named); return tname }
-
-// EmbeddedType returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds().
-func (t *Interface) EmbeddedType(i int) Type { return t.embeddeds[i] }
-
-// NumMethods returns the total number of methods of interface t.
-// The interface must have been completed.
-func (t *Interface) NumMethods() int { t.assertCompleteness(); return len(t.allMethods) }
-
-func (t *Interface) assertCompleteness() {
-	if t.allMethods == nil {
-		panic("interface is incomplete")
-	}
-}
-
-// Method returns the i'th method of interface t for 0 <= i < t.NumMethods().
-// The methods are ordered by their unique Id.
-// The interface must have been completed.
-func (t *Interface) Method(i int) *Func { t.assertCompleteness(); return t.allMethods[i] }
-
-// Empty reports whether t is the empty interface.
-func (t *Interface) Empty() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		// A non-nil allTypes may still be empty and represents the bottom type.
-		return len(t.allMethods) == 0 && t.allTypes == nil
-	}
-	return !t.iterate(func(t *Interface) bool {
-		return len(t.methods) > 0 || t.types != nil
-	}, nil)
-}
-
-// _HasTypeList reports whether interface t has a type list, possibly from an embedded type.
-func (t *Interface) _HasTypeList() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		return t.allTypes != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		return t.types != nil
-	}, nil)
-}
-
-// _IsComparable reports whether interface t is or embeds the predeclared interface "comparable".
-func (t *Interface) _IsComparable() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		_, m := lookupMethod(t.allMethods, nil, "==")
-		return m != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		_, m := lookupMethod(t.methods, nil, "==")
-		return m != nil
-	}, nil)
-}
-
-// _IsConstraint reports t.HasTypeList() || t.IsComparable().
-func (t *Interface) _IsConstraint() bool {
-	if t.allMethods != nil {
-		// interface is complete - quick test
-		if t.allTypes != nil {
-			return true
-		}
-		_, m := lookupMethod(t.allMethods, nil, "==")
-		return m != nil
-	}
-
-	return t.iterate(func(t *Interface) bool {
-		if t.types != nil {
-			return true
-		}
-		_, m := lookupMethod(t.methods, nil, "==")
-		return m != nil
-	}, nil)
-}
-
-// iterate calls f with t and then with any embedded interface of t, recursively, until f returns true.
-// iterate reports whether any call to f returned true.
-func (t *Interface) iterate(f func(*Interface) bool, seen map[*Interface]bool) bool {
-	if f(t) {
-		return true
-	}
-	for _, e := range t.embeddeds {
-		// e should be an interface but be careful (it may be invalid)
-		if e := asInterface(e); e != nil {
-			// Cyclic interfaces such as "type E interface { E }" are not permitted
-			// but they are still constructed and we need to detect such cycles.
-			if seen[e] {
-				continue
-			}
-			if seen == nil {
-				seen = make(map[*Interface]bool)
-			}
-			seen[e] = true
-			if e.iterate(f, seen) {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-// isSatisfiedBy reports whether interface t's type list is satisfied by the type typ.
-// If the type list is empty (absent), typ trivially satisfies the interface.
-// TODO(gri) This is not a great name. Eventually, we should have a more comprehensive
-//           "implements" predicate.
-func (t *Interface) isSatisfiedBy(typ Type) bool {
-	t.Complete()
-	if t.allTypes == nil {
-		return true
-	}
-	types := unpackType(t.allTypes)
-	return includes(types, typ) || includes(types, under(typ))
-}
-
-// Complete computes the interface's method set. It must be called by users of
-// NewInterfaceType and NewInterface after the interface's embedded types are
-// fully defined and before using the interface type in any way other than to
-// form other types. The interface must not contain duplicate methods or a
-// panic occurs. Complete returns the receiver.
-func (t *Interface) Complete() *Interface {
-	// TODO(gri) consolidate this method with Checker.completeInterface
-	if t.allMethods != nil {
-		return t
-	}
-
-	t.allMethods = markComplete // avoid infinite recursion
-
-	var todo []*Func
-	var methods []*Func
-	var seen objset
-	addMethod := func(m *Func, explicit bool) {
-		switch other := seen.insert(m); {
-		case other == nil:
-			methods = append(methods, m)
-		case explicit:
-			panic("duplicate method " + m.name)
-		default:
-			// check method signatures after all locally embedded interfaces are computed
-			todo = append(todo, m, other.(*Func))
-		}
-	}
-
-	for _, m := range t.methods {
-		addMethod(m, true)
-	}
-
-	allTypes := t.types
-
-	for _, typ := range t.embeddeds {
-		utyp := under(typ)
-		etyp := asInterface(utyp)
-		if etyp == nil {
-			if utyp != Typ[Invalid] {
-				panic(fmt.Sprintf("%s is not an interface", typ))
-			}
-			continue
-		}
-		etyp.Complete()
-		for _, m := range etyp.allMethods {
-			addMethod(m, false)
-		}
-		allTypes = intersect(allTypes, etyp.allTypes)
-	}
-
-	for i := 0; i < len(todo); i += 2 {
-		m := todo[i]
-		other := todo[i+1]
-		if !Identical(m.typ, other.typ) {
-			panic("duplicate method " + m.name)
-		}
-	}
-
-	if methods != nil {
-		sortMethods(methods)
-		t.allMethods = methods
-	}
-	t.allTypes = allTypes
-
 	return t
 }
 
-// A Map represents a map type.
-type Map struct {
-	key, elem Type
-}
-
-// NewMap returns a new map for the given key and element types.
-func NewMap(key, elem Type) *Map {
-	return &Map{key: key, elem: elem}
-}
-
-// Key returns the key type of map m.
-func (m *Map) Key() Type { return m.key }
-
-// Elem returns the element type of map m.
-func (m *Map) Elem() Type { return m.elem }
-
-// A Chan represents a channel type.
-type Chan struct {
-	dir  ChanDir
-	elem Type
-}
-
-// A ChanDir value indicates a channel direction.
-type ChanDir int
-
-// The direction of a channel is indicated by one of these constants.
-const (
-	SendRecv ChanDir = iota
-	SendOnly
-	RecvOnly
-)
-
-// NewChan returns a new channel type for the given direction and element type.
-func NewChan(dir ChanDir, elem Type) *Chan {
-	return &Chan{dir: dir, elem: elem}
-}
-
-// Dir returns the direction of channel c.
-func (c *Chan) Dir() ChanDir { return c.dir }
-
-// Elem returns the element type of channel c.
-func (c *Chan) Elem() Type { return c.elem }
-
-// A Named represents a named (defined) type.
-type Named struct {
-	check      *Checker    // for Named.under implementation
-	info       typeInfo    // for cycle detection
-	obj        *TypeName   // corresponding declared object
-	orig       Type        // type (on RHS of declaration) this *Named type is derived of (for cycle reporting)
-	underlying Type        // possibly a *Named during setup; never a *Named once set up completely
-	tparams    []*TypeName // type parameters, or nil
-	targs      []Type      // type arguments (after instantiation), or nil
-	methods    []*Func     // methods declared for this type (not the method set of this type); signatures are type-checked lazily
-}
-
-// NewNamed returns a new named type for the given type name, underlying type, and associated methods.
-// If the given type name obj doesn't have a type yet, its type is set to the returned named type.
-// The underlying type must not be a *Named.
-func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
-	if _, ok := underlying.(*Named); ok {
-		panic("types.NewNamed: underlying type must not be *Named")
-	}
-	typ := &Named{obj: obj, orig: underlying, underlying: underlying, methods: methods}
-	if obj.typ == nil {
-		obj.typ = typ
-	}
-	return typ
-}
-
-func (check *Checker) newNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
-	typ := &Named{check: check, obj: obj, orig: underlying, underlying: underlying, methods: methods}
-	if obj.typ == nil {
-		obj.typ = typ
-	}
-	return typ
-}
-
-// Obj returns the type name for the named type t.
-func (t *Named) Obj() *TypeName { return t.obj }
-
-// TODO(gri) Come up with a better representation and API to distinguish
-//           between parameterized instantiated and non-instantiated types.
-
-// _TParams returns the type parameters of the named type t, or nil.
-// The result is non-nil for an (originally) parameterized type even if it is instantiated.
-func (t *Named) _TParams() []*TypeName { return t.tparams }
-
-// _TArgs returns the type arguments after instantiation of the named type t, or nil if not instantiated.
-func (t *Named) _TArgs() []Type { return t.targs }
-
-// _SetTArgs sets the type arguments of Named.
-func (t *Named) _SetTArgs(args []Type) { t.targs = args }
-
-// NumMethods returns the number of explicit methods whose receiver is named type t.
-func (t *Named) NumMethods() int { return len(t.methods) }
-
-// Method returns the i'th method of named type t for 0 <= i < t.NumMethods().
-func (t *Named) Method(i int) *Func { return t.methods[i] }
-
-// SetUnderlying sets the underlying type and marks t as complete.
-func (t *Named) SetUnderlying(underlying Type) {
-	if underlying == nil {
-		panic("types.Named.SetUnderlying: underlying type must not be nil")
-	}
-	if _, ok := underlying.(*Named); ok {
-		panic("types.Named.SetUnderlying: underlying type must not be *Named")
-	}
-	t.underlying = underlying
-}
-
-// AddMethod adds method m unless it is already in the method list.
-func (t *Named) AddMethod(m *Func) {
-	if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 {
-		t.methods = append(t.methods, m)
-	}
-}
-
-// Note: This is a uint32 rather than a uint64 because the
-// respective 64 bit atomic instructions are not available
-// on all platforms.
-var lastId uint32
-
-// nextId returns a value increasing monotonically by 1 with
-// each call, starting with 1. It may be called concurrently.
-func nextId() uint64 { return uint64(atomic.AddUint32(&lastId, 1)) }
-
-// A _TypeParam represents a type parameter type.
-type _TypeParam struct {
-	check *Checker  // for lazy type bound completion
-	id    uint64    // unique id
-	obj   *TypeName // corresponding type name
-	index int       // parameter index
-	bound Type      // *Named or *Interface; underlying type is always *Interface
-}
-
-// newTypeParam returns a new TypeParam.
-func (check *Checker) newTypeParam(obj *TypeName, index int, bound Type) *_TypeParam {
-	assert(bound != nil)
-	typ := &_TypeParam{check: check, id: nextId(), obj: obj, index: index, bound: bound}
-	if obj.typ == nil {
-		obj.typ = typ
-	}
-	return typ
-}
-
-func (t *_TypeParam) Bound() *Interface {
-	iface := asInterface(t.bound)
-	// use the type bound position if we have one
-	pos := token.NoPos
-	if n, _ := t.bound.(*Named); n != nil {
-		pos = n.obj.pos
-	}
-	// TODO(rFindley) switch this to an unexported method on Checker.
-	t.check.completeInterface(pos, iface)
-	return iface
-}
-
 // optype returns a type's operational type. Except for
 // type parameters, the operational type is the same
 // as the underlying type (as returned by under). For
@@ -771,130 +56,22 @@ func optype(typ Type) Type {
 		// for a type parameter list of the form:
 		// (type T interface { type T }).
 		// See also issue #39680.
-		if u := t.Bound().allTypes; u != nil && u != typ {
-			// u != typ and u is a type parameter => under(u) != typ, so this is ok
-			return under(u)
+		if a := t.iface().typeSet().types; a != nil && a != typ {
+			// If we have a union with a single entry, ignore
+			// any tilde because under(~t) == under(t).
+			if u, _ := a.(*Union); u != nil && u.NumTerms() == 1 {
+				a, _ = u.Term(0)
+			}
+			if a != typ {
+				// a != typ and a is a type parameter => under(a) != typ, so this is ok
+				return under(a)
+			}
 		}
 		return theTop
 	}
 	return under(typ)
 }
 
-// An instance represents an instantiated generic type syntactically
-// (without expanding the instantiation). Type instances appear only
-// during type-checking and are replaced by their fully instantiated
-// (expanded) types before the end of type-checking.
-type instance struct {
-	check   *Checker    // for lazy instantiation
-	pos     token.Pos   // position of type instantiation; for error reporting only
-	base    *Named      // parameterized type to be instantiated
-	targs   []Type      // type arguments
-	poslist []token.Pos // position of each targ; for error reporting only
-	value   Type        // base(targs...) after instantiation or Typ[Invalid]; nil if not yet set
-}
-
-// expand returns the instantiated (= expanded) type of t.
-// The result is either an instantiated *Named type, or
-// Typ[Invalid] if there was an error.
-func (t *instance) expand() Type {
-	v := t.value
-	if v == nil {
-		v = t.check.instantiate(t.pos, t.base, t.targs, t.poslist)
-		if v == nil {
-			v = Typ[Invalid]
-		}
-		t.value = v
-	}
-	// After instantiation we must have an invalid or a *Named type.
-	if debug && v != Typ[Invalid] {
-		_ = v.(*Named)
-	}
-	return v
-}
-
-// expand expands a type instance into its instantiated
-// type and leaves all other types alone. expand does
-// not recurse.
-func expand(typ Type) Type {
-	if t, _ := typ.(*instance); t != nil {
-		return t.expand()
-	}
-	return typ
-}
-
-// expandf is set to expand.
-// Call expandf when calling expand causes compile-time cycle error.
-var expandf func(Type) Type
-
-func init() { expandf = expand }
-
-// bottom represents the bottom of the type lattice.
-// It is the underlying type of a type parameter that
-// cannot be satisfied by any type, usually because
-// the intersection of type constraints left nothing).
-type bottom struct{}
-
-// theBottom is the singleton bottom type.
-var theBottom = &bottom{}
-
-// top represents the top of the type lattice.
-// It is the underlying type of a type parameter that
-// can be satisfied by any type (ignoring methods),
-// usually because the type constraint has no type
-// list.
-type top struct{}
-
-// theTop is the singleton top type.
-var theTop = &top{}
-
-// Type-specific implementations of Underlying.
-func (t *Basic) Underlying() Type      { return t }
-func (t *Array) Underlying() Type      { return t }
-func (t *Slice) Underlying() Type      { return t }
-func (t *Struct) Underlying() Type     { return t }
-func (t *Pointer) Underlying() Type    { return t }
-func (t *Tuple) Underlying() Type      { return t }
-func (t *Signature) Underlying() Type  { return t }
-func (t *_Sum) Underlying() Type       { return t }
-func (t *Interface) Underlying() Type  { return t }
-func (t *Map) Underlying() Type        { return t }
-func (t *Chan) Underlying() Type       { return t }
-func (t *Named) Underlying() Type      { return t.underlying }
-func (t *_TypeParam) Underlying() Type { return t }
-func (t *instance) Underlying() Type   { return t }
-func (t *bottom) Underlying() Type     { return t }
-func (t *top) Underlying() Type        { return t }
-
-// Type-specific implementations of String.
-func (t *Basic) String() string      { return TypeString(t, nil) }
-func (t *Array) String() string      { return TypeString(t, nil) }
-func (t *Slice) String() string      { return TypeString(t, nil) }
-func (t *Struct) String() string     { return TypeString(t, nil) }
-func (t *Pointer) String() string    { return TypeString(t, nil) }
-func (t *Tuple) String() string      { return TypeString(t, nil) }
-func (t *Signature) String() string  { return TypeString(t, nil) }
-func (t *_Sum) String() string       { return TypeString(t, nil) }
-func (t *Interface) String() string  { return TypeString(t, nil) }
-func (t *Map) String() string        { return TypeString(t, nil) }
-func (t *Chan) String() string       { return TypeString(t, nil) }
-func (t *Named) String() string      { return TypeString(t, nil) }
-func (t *_TypeParam) String() string { return TypeString(t, nil) }
-func (t *instance) String() string   { return TypeString(t, nil) }
-func (t *bottom) String() string     { return TypeString(t, nil) }
-func (t *top) String() string        { return TypeString(t, nil) }
-
-// under returns the true expanded underlying type.
-// If it doesn't exist, the result is Typ[Invalid].
-// under must only be called when a type is known
-// to be fully set up.
-func under(t Type) Type {
-	// TODO(gri) is this correct for *Sum?
-	if n := asNamed(t); n != nil {
-		return n.under()
-	}
-	return t
-}
-
 // Converters
 //
 // A converter must only be called when a type is
@@ -928,46 +105,26 @@ func asPointer(t Type) *Pointer {
 	return op
 }
 
-func asTuple(t Type) *Tuple {
-	op, _ := optype(t).(*Tuple)
-	return op
-}
-
 func asSignature(t Type) *Signature {
 	op, _ := optype(t).(*Signature)
 	return op
 }
 
-func asSum(t Type) *_Sum {
-	op, _ := optype(t).(*_Sum)
-	return op
-}
+// If the argument to asInterface, asNamed, or asTypeParam is of the respective type
+// (possibly after expanding an instance type), these methods return that type.
+// Otherwise the result is nil.
 
 func asInterface(t Type) *Interface {
 	op, _ := optype(t).(*Interface)
 	return op
 }
 
-func asMap(t Type) *Map {
-	op, _ := optype(t).(*Map)
-	return op
-}
-
-func asChan(t Type) *Chan {
-	op, _ := optype(t).(*Chan)
-	return op
-}
-
-// If the argument to asNamed and asTypeParam is of the respective types
-// (possibly after expanding an instance type), these methods return that type.
-// Otherwise the result is nil.
-
 func asNamed(t Type) *Named {
 	e, _ := expand(t).(*Named)
 	return e
 }
 
-func asTypeParam(t Type) *_TypeParam {
-	u, _ := under(t).(*_TypeParam)
+func asTypeParam(t Type) *TypeParam {
+	u, _ := under(t).(*TypeParam)
 	return u
 }
diff --git a/src/go/types/typeparam.go b/src/go/types/typeparam.go
new file mode 100644
index 00000000000..33a516c2097
--- /dev/null
+++ b/src/go/types/typeparam.go
@@ -0,0 +1,136 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"go/token"
+	"sync/atomic"
+)
+
+// Note: This is a uint32 rather than a uint64 because the
+// respective 64 bit atomic instructions are not available
+// on all platforms.
+var lastID uint32
+
+// nextID returns a value increasing monotonically by 1 with
+// each call, starting with 1. It may be called concurrently.
+func nextID() uint64 { return uint64(atomic.AddUint32(&lastID, 1)) }
+
+// A TypeParam represents a type parameter type.
+type TypeParam struct {
+	check *Checker  // for lazy type bound completion
+	id    uint64    // unique id, for debugging only
+	obj   *TypeName // corresponding type name
+	index int       // type parameter index in source order, starting at 0
+	// TODO(rfindley): this could also be Typ[Invalid]. Verify that this is handled correctly.
+	bound Type // *Named or *Interface; underlying type is always *Interface
+}
+
+// NewTypeParam returns a new TypeParam. Type parameters may be set on a Named
+// or Signature type by calling SetTParams. Setting a type parameter on more
+// than one type will result in a panic.
+//
+// The bound argument can be nil, and set later via SetBound.
+func (check *Checker) NewTypeParam(obj *TypeName, bound Type) *TypeParam {
+	// Always increment lastID, even if it is not used.
+	id := nextID()
+	if check != nil {
+		check.nextID++
+		id = check.nextID
+	}
+	typ := &TypeParam{check: check, id: id, obj: obj, index: -1, bound: bound}
+	if obj.typ == nil {
+		obj.typ = typ
+	}
+	return typ
+}
+
+// TODO(rfindley): remove or export these placeholder APIs.
+
+// Index returns the index of the type param within its param list.
+func (t *TypeParam) _Index() int {
+	return t.index
+}
+
+// SetId sets the unique id of a type param. Should only be used for type params
+// in imported generic types.
+func (t *TypeParam) _SetId(id uint64) {
+	t.id = id
+}
+
+// Constraint returns the type constraint specified for t.
+func (t *TypeParam) Constraint() Type {
+	// compute the type set if possible (we may not have an interface)
+	if iface, _ := under(t.bound).(*Interface); iface != nil {
+		// use the type bound position if we have one
+		pos := token.NoPos
+		if n, _ := t.bound.(*Named); n != nil {
+			pos = n.obj.pos
+		}
+		computeTypeSet(t.check, pos, iface)
+	}
+	return t.bound
+}
+
+// SetConstraint sets the type constraint for t.
+func (t *TypeParam) SetConstraint(bound Type) {
+	if bound == nil {
+		panic("types2.TypeParam.SetConstraint: bound must not be nil")
+	}
+	t.bound = bound
+}
+
+// iface returns the constraint interface of t.
+func (t *TypeParam) iface() *Interface {
+	if iface, _ := under(t.Constraint()).(*Interface); iface != nil {
+		return iface
+	}
+	return &emptyInterface
+}
+
+func (t *TypeParam) Underlying() Type { return t }
+func (t *TypeParam) String() string   { return TypeString(t, nil) }
+
+// TypeParams holds a list of type parameters bound to a type.
+type TypeParams struct{ tparams []*TypeName }
+
+// Len returns the number of type parameters in the list.
+// It is safe to call on a nil receiver.
+func (tps *TypeParams) Len() int {
+	return len(tps.list())
+}
+
+// At returns the i'th type parameter in the list.
+func (tps *TypeParams) At(i int) *TypeName {
+	return tps.list()[i]
+}
+
+func (tps *TypeParams) list() []*TypeName {
+	if tps == nil {
+		return nil
+	}
+	return tps.tparams
+}
+
+func bindTParams(list []*TypeName) *TypeParams {
+	if len(list) == 0 {
+		return nil
+	}
+	for i, tp := range list {
+		typ := tp.Type().(*TypeParam)
+		if typ.index >= 0 {
+			panic("internal error: type parameter bound more than once")
+		}
+		typ.index = i
+	}
+	return &TypeParams{tparams: list}
+}
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+func (t *TypeParam) underIs(f func(Type) bool) bool {
+	return t.iface().typeSet().underIs(f)
+}
diff --git a/src/go/types/types_test.go b/src/go/types/types_test.go
index fd9462c4a27..f2358c6e198 100644
--- a/src/go/types/types_test.go
+++ b/src/go/types/types_test.go
@@ -4,10 +4,5 @@
 
 package types
 
-import "sync/atomic"
-
-// Upon calling ResetId, nextId starts with 1 again.
-// It may be called concurrently. This is only needed
-// for tests where we may want to have a consistent
-// numbering for each individual test case.
-func ResetId() { atomic.StoreUint32(&lastId, 0) }
+// Debug is set if go/types is built with debug mode enabled.
+const Debug = debug
diff --git a/src/go/types/typeset.go b/src/go/types/typeset.go
new file mode 100644
index 00000000000..836f93047a2
--- /dev/null
+++ b/src/go/types/typeset.go
@@ -0,0 +1,298 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"bytes"
+	"fmt"
+	"go/token"
+	"sort"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A _TypeSet represents the type set of an interface.
+type _TypeSet struct {
+	comparable bool // if set, the interface is or embeds comparable
+	// TODO(gri) consider using a set for the methods for faster lookup
+	methods []*Func // all methods of the interface; sorted by unique ID
+	types   Type    // typically a *Union; nil means no type restrictions
+}
+
+// IsTop reports whether type set s is the top type set (corresponding to the empty interface).
+func (s *_TypeSet) IsTop() bool { return !s.comparable && len(s.methods) == 0 && s.types == nil }
+
+// IsMethodSet reports whether the type set s is described by a single set of methods.
+func (s *_TypeSet) IsMethodSet() bool { return !s.comparable && s.types == nil }
+
+// IsComparable reports whether each type in the set is comparable.
+// TODO(gri) this is not correct - there may be s.types values containing non-comparable types
+func (s *_TypeSet) IsComparable() bool {
+	if s.types == nil {
+		return s.comparable
+	}
+	tcomparable := s.underIs(func(u Type) bool {
+		return Comparable(u)
+	})
+	if !s.comparable {
+		return tcomparable
+	}
+	return s.comparable && tcomparable
+}
+
+// TODO(gri) IsTypeSet is not a great name. Find a better one.
+
+// IsTypeSet reports whether the type set s is represented by a finite set of underlying types.
+func (s *_TypeSet) IsTypeSet() bool {
+	return !s.comparable && len(s.methods) == 0
+}
+
+// NumMethods returns the number of methods available.
+func (s *_TypeSet) NumMethods() int { return len(s.methods) }
+
+// Method returns the i'th method of type set s for 0 <= i < s.NumMethods().
+// The methods are ordered by their unique ID.
+func (s *_TypeSet) Method(i int) *Func { return s.methods[i] }
+
+// LookupMethod returns the index of and method with matching package and name, or (-1, nil).
+func (s *_TypeSet) LookupMethod(pkg *Package, name string) (int, *Func) {
+	// TODO(gri) s.methods is sorted - consider binary search
+	return lookupMethod(s.methods, pkg, name)
+}
+
+func (s *_TypeSet) String() string {
+	if s.IsTop() {
+		return "⊤"
+	}
+
+	var buf bytes.Buffer
+	buf.WriteByte('{')
+	if s.comparable {
+		buf.WriteString(" comparable")
+		if len(s.methods) > 0 || s.types != nil {
+			buf.WriteByte(';')
+		}
+	}
+	for i, m := range s.methods {
+		if i > 0 {
+			buf.WriteByte(';')
+		}
+		buf.WriteByte(' ')
+		buf.WriteString(m.String())
+	}
+	if len(s.methods) > 0 && s.types != nil {
+		buf.WriteByte(';')
+	}
+	if s.types != nil {
+		buf.WriteByte(' ')
+		writeType(&buf, s.types, nil, nil)
+	}
+
+	buf.WriteString(" }") // there was a least one method or type
+	return buf.String()
+}
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+// underIs reports whether f returned true for the underlying types of the
+// enumerable types in the type set s. If the type set comprises all types
+// f is called once with the top type; if the type set is empty, the result
+// is false.
+func (s *_TypeSet) underIs(f func(Type) bool) bool {
+	switch t := s.types.(type) {
+	case nil:
+		return f(theTop)
+	default:
+		return f(t)
+	case *Union:
+		return t.underIs(f)
+	}
+}
+
+// topTypeSet may be used as type set for the empty interface.
+var topTypeSet _TypeSet
+
+// computeTypeSet may be called with check == nil.
+func computeTypeSet(check *Checker, pos token.Pos, ityp *Interface) *_TypeSet {
+	if ityp.tset != nil {
+		return ityp.tset
+	}
+
+	// If the interface is not fully set up yet, the type set will
+	// not be complete, which may lead to errors when using the the
+	// type set (e.g. missing method). Don't compute a partial type
+	// set (and don't store it!), so that we still compute the full
+	// type set eventually. Instead, return the top type set and
+	// let any follow-on errors play out.
+	//
+	// TODO(gri) Consider recording when this happens and reporting
+	// it as an error (but only if there were no other errors so to
+	// to not have unnecessary follow-on errors).
+	if !ityp.complete {
+		return &topTypeSet
+	}
+
+	if check != nil && trace {
+		// Types don't generally have position information.
+		// If we don't have a valid pos provided, try to use
+		// one close enough.
+		if !pos.IsValid() && len(ityp.methods) > 0 {
+			pos = ityp.methods[0].pos
+		}
+
+		check.trace(pos, "type set for %s", ityp)
+		check.indent++
+		defer func() {
+			check.indent--
+			check.trace(pos, "=> %s ", ityp.typeSet())
+		}()
+	}
+
+	// An infinitely expanding interface (due to a cycle) is detected
+	// elsewhere (Checker.validType), so here we simply assume we only
+	// have valid interfaces. Mark the interface as complete to avoid
+	// infinite recursion if the validType check occurs later for some
+	// reason.
+	ityp.tset = new(_TypeSet) // TODO(gri) is this sufficient?
+
+	// Methods of embedded interfaces are collected unchanged; i.e., the identity
+	// of a method I.m's Func Object of an interface I is the same as that of
+	// the method m in an interface that embeds interface I. On the other hand,
+	// if a method is embedded via multiple overlapping embedded interfaces, we
+	// don't provide a guarantee which "original m" got chosen for the embedding
+	// interface. See also issue #34421.
+	//
+	// If we don't care to provide this identity guarantee anymore, instead of
+	// reusing the original method in embeddings, we can clone the method's Func
+	// Object and give it the position of a corresponding embedded interface. Then
+	// we can get rid of the mpos map below and simply use the cloned method's
+	// position.
+
+	var todo []*Func
+	var seen objset
+	var methods []*Func
+	mpos := make(map[*Func]token.Pos) // method specification or method embedding position, for good error messages
+	addMethod := func(pos token.Pos, m *Func, explicit bool) {
+		switch other := seen.insert(m); {
+		case other == nil:
+			methods = append(methods, m)
+			mpos[m] = pos
+		case explicit:
+			if check == nil {
+				panic(fmt.Sprintf("%v: duplicate method %s", m.pos, m.name))
+			}
+			// check != nil
+			check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
+			check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
+		default:
+			// We have a duplicate method name in an embedded (not explicitly declared) method.
+			// Check method signatures after all types are computed (issue #33656).
+			// If we're pre-go1.14 (overlapping embeddings are not permitted), report that
+			// error here as well (even though we could do it eagerly) because it's the same
+			// error message.
+			if check == nil {
+				// check method signatures after all locally embedded interfaces are computed
+				todo = append(todo, m, other.(*Func))
+				break
+			}
+			// check != nil
+			check.later(func() {
+				if !check.allowVersion(m.pkg, 1, 14) || !Identical(m.typ, other.Type()) {
+					check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
+					check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
+				}
+			})
+		}
+	}
+
+	for _, m := range ityp.methods {
+		addMethod(m.pos, m, true)
+	}
+
+	// collect embedded elements
+	var allTypes Type
+	for i, typ := range ityp.embeddeds {
+		// The embedding position is nil for imported interfaces
+		// and also for interface copies after substitution (but
+		// in that case we don't need to report errors again).
+		var pos token.Pos // embedding position
+		if ityp.embedPos != nil {
+			pos = (*ityp.embedPos)[i]
+		}
+		var types Type
+		switch t := under(typ).(type) {
+		case *Interface:
+			tset := computeTypeSet(check, pos, t)
+			if tset.comparable {
+				ityp.tset.comparable = true
+			}
+			for _, m := range tset.methods {
+				addMethod(pos, m, false) // use embedding position pos rather than m.pos
+
+			}
+			types = tset.types
+		case *Union:
+			// TODO(gri) combine with default case once we have
+			//           converted all tests to new notation and we
+			//           can report an error when we don't have an
+			//           interface before go1.18.
+			types = typ
+		case *TypeParam:
+			// Embedding stand-alone type parameters is not permitted for now.
+			// This case is handled during union parsing.
+			unreachable()
+		default:
+			if typ == Typ[Invalid] {
+				continue
+			}
+			if check != nil && !check.allowVersion(check.pkg, 1, 18) {
+				check.errorf(atPos(pos), _InvalidIfaceEmbed, "%s is not an interface", typ)
+				continue
+			}
+			types = typ
+		}
+		allTypes = intersect(allTypes, types)
+	}
+	ityp.embedPos = nil // not needed anymore (errors have been reported)
+
+	// process todo's (this only happens if check == nil)
+	for i := 0; i < len(todo); i += 2 {
+		m := todo[i]
+		other := todo[i+1]
+		if !Identical(m.typ, other.typ) {
+			panic(fmt.Sprintf("%v: duplicate method %s", m.pos, m.name))
+		}
+	}
+
+	if methods != nil {
+		sort.Sort(byUniqueMethodName(methods))
+		ityp.tset.methods = methods
+	}
+	ityp.tset.types = allTypes
+
+	return ityp.tset
+}
+
+func sortMethods(list []*Func) {
+	sort.Sort(byUniqueMethodName(list))
+}
+
+func assertSortedMethods(list []*Func) {
+	if !debug {
+		panic("internal error: assertSortedMethods called outside debug mode")
+	}
+	if !sort.IsSorted(byUniqueMethodName(list)) {
+		panic("internal error: methods not sorted")
+	}
+}
+
+// byUniqueMethodName method lists can be sorted by their unique method names.
+type byUniqueMethodName []*Func
+
+func (a byUniqueMethodName) Len() int           { return len(a) }
+func (a byUniqueMethodName) Less(i, j int) bool { return a[i].Id() < a[j].Id() }
+func (a byUniqueMethodName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
diff --git a/src/go/types/typestring.go b/src/go/types/typestring.go
index fe27f0f276c..c0c69624ec7 100644
--- a/src/go/types/typestring.go
+++ b/src/go/types/typestring.go
@@ -158,12 +158,19 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		buf.WriteString("func")
 		writeSignature(buf, t, qf, visited)
 
-	case *_Sum:
-		for i, t := range t.types {
+	case *Union:
+		if t.IsEmpty() {
+			buf.WriteString("⊥")
+			break
+		}
+		for i, t := range t.terms {
 			if i > 0 {
-				buf.WriteString(", ")
+				buf.WriteByte('|')
 			}
-			writeType(buf, t, qf, visited)
+			if t.tilde {
+				buf.WriteByte('~')
+			}
+			writeType(buf, t.typ, qf, visited)
 		}
 
 	case *Interface:
@@ -183,7 +190,8 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		if gcCompatibilityMode {
 			// print flattened interface
 			// (useful to compare against gc-generated interfaces)
-			for i, m := range t.allMethods {
+			tset := t.typeSet()
+			for i, m := range tset.methods {
 				if i > 0 {
 					buf.WriteString("; ")
 				}
@@ -191,12 +199,12 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				writeSignature(buf, m.typ.(*Signature), qf, visited)
 				empty = false
 			}
-			if !empty && t.allTypes != nil {
+			if !empty && tset.types != nil {
 				buf.WriteString("; ")
 			}
-			if t.allTypes != nil {
+			if tset.types != nil {
 				buf.WriteString("type ")
-				writeType(buf, t.allTypes, qf, visited)
+				writeType(buf, tset.types, qf, visited)
 			}
 		} else {
 			// print explicit interface methods and embedded types
@@ -208,14 +216,6 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				writeSignature(buf, m.typ.(*Signature), qf, visited)
 				empty = false
 			}
-			if !empty && t.types != nil {
-				buf.WriteString("; ")
-			}
-			if t.types != nil {
-				buf.WriteString("type ")
-				writeType(buf, t.types, qf, visited)
-				empty = false
-			}
 			if !empty && len(t.embeddeds) > 0 {
 				buf.WriteString("; ")
 			}
@@ -227,7 +227,9 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				empty = false
 			}
 		}
-		if t.allMethods == nil || len(t.methods) > len(t.allMethods) {
+		// print /* incomplete */ if needed to satisfy existing tests
+		// TODO(gri) get rid of this eventually
+		if debug && t.tset == nil {
 			if !empty {
 				buf.WriteByte(' ')
 			}
@@ -268,39 +270,40 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 		}
 
 	case *Named:
+		if t.instance != nil {
+			buf.WriteByte(instanceMarker)
+		}
 		writeTypeName(buf, t.obj, qf)
 		if t.targs != nil {
 			// instantiated type
 			buf.WriteByte('[')
 			writeTypeList(buf, t.targs, qf, visited)
 			buf.WriteByte(']')
-		} else if t.tparams != nil {
+		} else if t.TParams().Len() != 0 {
 			// parameterized type
-			writeTParamList(buf, t.tparams, qf, visited)
+			writeTParamList(buf, t.TParams().list(), qf, visited)
 		}
 
-	case *_TypeParam:
+	case *TypeParam:
 		s := "?"
 		if t.obj != nil {
+			// Optionally write out package for typeparams (like Named).
+			// TODO(rfindley): this is required for import/export, so
+			// we maybe need a separate function that won't be changed
+			// for debugging purposes.
+			if t.obj.pkg != nil {
+				writePackage(buf, t.obj.pkg, qf)
+			}
 			s = t.obj.name
 		}
 		buf.WriteString(s + subscript(t.id))
 
-	case *instance:
-		buf.WriteByte(instanceMarker) // indicate "non-evaluated" syntactic instance
-		writeTypeName(buf, t.base.obj, qf)
-		buf.WriteByte('[')
-		writeTypeList(buf, t.targs, qf, visited)
-		buf.WriteByte(']')
-
-	case *bottom:
-		buf.WriteString("⊥")
-
 	case *top:
 		buf.WriteString("⊤")
 
 	default:
 		// For externally defined implementations of Type.
+		// Note: In this case cycles won't be caught.
 		buf.WriteString(t.String())
 	}
 }
@@ -321,7 +324,7 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited
 	for i, p := range list {
 		// TODO(rFindley) support 'any' sugar here.
 		var b Type = &emptyInterface
-		if t, _ := p.typ.(*_TypeParam); t != nil && t.bound != nil {
+		if t, _ := p.typ.(*TypeParam); t != nil && t.bound != nil {
 			b = t.bound
 		}
 		if i > 0 {
@@ -334,7 +337,7 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited
 		}
 		prev = b
 
-		if t, _ := p.typ.(*_TypeParam); t != nil {
+		if t, _ := p.typ.(*TypeParam); t != nil {
 			writeType(buf, t, qf, visited)
 		} else {
 			buf.WriteString(p.name)
@@ -348,17 +351,38 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited
 }
 
 func writeTypeName(buf *bytes.Buffer, obj *TypeName, qf Qualifier) {
-	s := ""
-	if obj != nil {
-		if obj.pkg != nil {
-			writePackage(buf, obj.pkg, qf)
-		}
-		// TODO(gri): function-local named types should be displayed
-		// differently from named types at package level to avoid
-		// ambiguity.
-		s = obj.name
+	if obj == nil {
+		buf.WriteString("")
+		return
+	}
+	if obj.pkg != nil {
+		writePackage(buf, obj.pkg, qf)
+	}
+	buf.WriteString(obj.name)
+
+	if instanceHashing != 0 {
+		// For local defined types, use the (original!) TypeName's scope
+		// numbers to disambiguate.
+		typ := obj.typ.(*Named)
+		// TODO(gri) Figure out why typ.orig != typ.orig.orig sometimes
+		//           and whether the loop can iterate more than twice.
+		//           (It seems somehow connected to instance types.)
+		for typ.orig != typ {
+			typ = typ.orig
+		}
+		writeScopeNumbers(buf, typ.obj.parent)
+	}
+}
+
+// writeScopeNumbers writes the number sequence for this scope to buf
+// in the form ".i.j.k" where i, j, k, etc. stand for scope numbers.
+// If a scope is nil or has no parent (such as a package scope), nothing
+// is written.
+func writeScopeNumbers(buf *bytes.Buffer, s *Scope) {
+	if s != nil && s.number > 0 {
+		writeScopeNumbers(buf, s.parent)
+		fmt.Fprintf(buf, ".%d", s.number)
 	}
-	buf.WriteString(s)
 }
 
 func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visited []Type) {
@@ -403,8 +427,8 @@ func WriteSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier) {
 }
 
 func writeSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier, visited []Type) {
-	if sig.tparams != nil {
-		writeTParamList(buf, sig.tparams, qf, visited)
+	if sig.TParams().Len() != 0 {
+		writeTParamList(buf, sig.TParams().list(), qf, visited)
 	}
 
 	writeTuple(buf, sig.params, sig.variadic, qf, visited)
diff --git a/src/go/types/typestring_test.go b/src/go/types/typestring_test.go
index b16529dc641..f02c0d9c18d 100644
--- a/src/go/types/typestring_test.go
+++ b/src/go/types/typestring_test.go
@@ -95,6 +95,8 @@ var independentTestTypes = []testEntry{
 	dup("interface{}"),
 	dup("interface{m()}"),
 	dup(`interface{String() string; m(int) float32}`),
+	dup("interface{int|float32|complex128}"),
+	dup("interface{int|~float32|~complex128}"),
 
 	// TODO(rFindley) uncomment this once this AST is accepted, and add more test
 	// cases.
@@ -143,6 +145,10 @@ func TestTypeString(t *testing.T) {
 }
 
 func TestIncompleteInterfaces(t *testing.T) {
+	if !Debug {
+		t.Skip("requires type checker to be compiled with debug = true")
+	}
+
 	sig := NewSignature(nil, nil, nil, false)
 	m := NewFunc(token.NoPos, nil, "m", sig)
 	for _, test := range []struct {
diff --git a/src/go/types/typeterm.go b/src/go/types/typeterm.go
new file mode 100644
index 00000000000..dbd055a580c
--- /dev/null
+++ b/src/go/types/typeterm.go
@@ -0,0 +1,166 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+// TODO(gri) use a different symbol instead of ⊤ for the set of all types
+//           (⊤ is hard to distinguish from T in some fonts)
+
+// A term describes elementary type sets:
+//
+//   ∅:  (*term)(nil)     == ∅                      // set of no types (empty set)
+//   ⊤:  &term{}          == ⊤                      // set of all types
+//   T:  &term{false, T}  == {T}                    // set of type T
+//  ~t:  &term{true, t}   == {t' | under(t') == t}  // set of types with underlying type t
+//
+type term struct {
+	tilde bool // valid if typ != nil
+	typ   Type
+}
+
+func (x *term) String() string {
+	switch {
+	case x == nil:
+		return "∅"
+	case x.typ == nil:
+		return "⊤"
+	case x.tilde:
+		return "~" + x.typ.String()
+	default:
+		return x.typ.String()
+	}
+}
+
+// equal reports whether x and y represent the same type set.
+func (x *term) equal(y *term) bool {
+	// easy cases
+	switch {
+	case x == nil || y == nil:
+		return x == y
+	case x.typ == nil || y.typ == nil:
+		return x.typ == y.typ
+	}
+	// ∅ ⊂ x, y ⊂ ⊤
+
+	return x.tilde == y.tilde && Identical(x.typ, y.typ)
+}
+
+// union returns the union x ∪ y: zero, one, or two non-nil terms.
+func (x *term) union(y *term) (_, _ *term) {
+	// easy cases
+	switch {
+	case x == nil && y == nil:
+		return nil, nil // ∅ ∪ ∅ == ∅
+	case x == nil:
+		return y, nil // ∅ ∪ y == y
+	case y == nil:
+		return x, nil // x ∪ ∅ == x
+	case x.typ == nil:
+		return x, nil // ⊤ ∪ y == ⊤
+	case y.typ == nil:
+		return y, nil // x ∪ ⊤ == ⊤
+	}
+	// ∅ ⊂ x, y ⊂ ⊤
+
+	if x.disjoint(y) {
+		return x, y // x ∪ y == (x, y) if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ∪ ~t == ~t
+	// ~t ∪  T == ~t
+	//  T ∪ ~t == ~t
+	//  T ∪  T ==  T
+	if x.tilde || !y.tilde {
+		return x, nil
+	}
+	return y, nil
+}
+
+// intersect returns the intersection x ∩ y.
+func (x *term) intersect(y *term) *term {
+	// easy cases
+	switch {
+	case x == nil || y == nil:
+		return nil // ∅ ∩ y == ∅ and ∩ ∅ == ∅
+	case x.typ == nil:
+		return y // ⊤ ∩ y == y
+	case y.typ == nil:
+		return x // x ∩ ⊤ == x
+	}
+	// ∅ ⊂ x, y ⊂ ⊤
+
+	if x.disjoint(y) {
+		return nil // x ∩ y == ∅ if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ∩ ~t == ~t
+	// ~t ∩  T ==  T
+	//  T ∩ ~t ==  T
+	//  T ∩  T ==  T
+	if !x.tilde || y.tilde {
+		return x
+	}
+	return y
+}
+
+// includes reports whether t ∈ x.
+func (x *term) includes(t Type) bool {
+	// easy cases
+	switch {
+	case x == nil:
+		return false // t ∈ ∅ == false
+	case x.typ == nil:
+		return true // t ∈ ⊤ == true
+	}
+	// ∅ ⊂ x ⊂ ⊤
+
+	u := t
+	if x.tilde {
+		u = under(u)
+	}
+	return Identical(x.typ, u)
+}
+
+// subsetOf reports whether x ⊆ y.
+func (x *term) subsetOf(y *term) bool {
+	// easy cases
+	switch {
+	case x == nil:
+		return true // ∅ ⊆ y == true
+	case y == nil:
+		return false // x ⊆ ∅ == false since x != ∅
+	case y.typ == nil:
+		return true // x ⊆ ⊤ == true
+	case x.typ == nil:
+		return false // ⊤ ⊆ y == false since y != ⊤
+	}
+	// ∅ ⊂ x, y ⊂ ⊤
+
+	if x.disjoint(y) {
+		return false // x ⊆ y == false if x ∩ y == ∅
+	}
+	// x.typ == y.typ
+
+	// ~t ⊆ ~t == true
+	// ~t ⊆ T == false
+	//  T ⊆ ~t == true
+	//  T ⊆  T == true
+	return !x.tilde || y.tilde
+}
+
+// disjoint reports whether x ∩ y == ∅.
+// x.typ and y.typ must not be nil.
+func (x *term) disjoint(y *term) bool {
+	ux := x.typ
+	if y.tilde {
+		ux = under(ux)
+	}
+	uy := y.typ
+	if x.tilde {
+		uy = under(uy)
+	}
+	return !Identical(ux, uy)
+}
diff --git a/src/go/types/typeterm_test.go b/src/go/types/typeterm_test.go
new file mode 100644
index 00000000000..391ff3e05f8
--- /dev/null
+++ b/src/go/types/typeterm_test.go
@@ -0,0 +1,205 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"strings"
+	"testing"
+)
+
+var testTerms = map[string]*term{
+	"∅":       nil,
+	"⊤":       {},
+	"int":     {false, Typ[Int]},
+	"~int":    {true, Typ[Int]},
+	"string":  {false, Typ[String]},
+	"~string": {true, Typ[String]},
+	// TODO(gri) add a defined type
+}
+
+func TestTermString(t *testing.T) {
+	for want, x := range testTerms {
+		if got := x.String(); got != want {
+			t.Errorf("%v.String() == %v; want %v", x, got, want)
+		}
+	}
+}
+
+func split(s string, n int) []string {
+	r := strings.Split(s, " ")
+	if len(r) != n {
+		panic("invalid test case: " + s)
+	}
+	return r
+}
+
+func testTerm(name string) *term {
+	r, ok := testTerms[name]
+	if !ok {
+		panic("invalid test argument: " + name)
+	}
+	return r
+}
+
+func TestTermEqual(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ T",
+		"⊤ ⊤ T",
+		"int int T",
+		"~int ~int T",
+		"∅ ⊤ F",
+		"∅ int F",
+		"∅ ~int F",
+		"⊤ int F",
+		"⊤ ~int F",
+		"int ~int F",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.equal(y); got != want {
+			t.Errorf("%v.equal(%v) = %v; want %v", x, y, got, want)
+		}
+		// equal is symmetric
+		x, y = y, x
+		if got := x.equal(y); got != want {
+			t.Errorf("%v.equal(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermUnion(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ ∅ ∅",
+		"∅ ⊤ ⊤ ∅",
+		"∅ int int ∅",
+		"∅ ~int ~int ∅",
+		"⊤ ⊤ ⊤ ∅",
+		"⊤ int ⊤ ∅",
+		"⊤ ~int ⊤ ∅",
+		"int int int ∅",
+		"int ~int ~int ∅",
+		"int string int string",
+		"int ~string int ~string",
+		"~int ~string ~int ~string",
+
+		// union is symmetric, but the result order isn't - repeat symmetric cases explictly
+		"⊤ ∅ ⊤ ∅",
+		"int ∅ int ∅",
+		"~int ∅ ~int ∅",
+		"int ⊤ ⊤ ∅",
+		"~int ⊤ ⊤ ∅",
+		"~int int ~int ∅",
+		"string int string int",
+		"~string int ~string int",
+		"~string ~int ~string ~int",
+	} {
+		args := split(test, 4)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want1 := testTerm(args[2])
+		want2 := testTerm(args[3])
+		if got1, got2 := x.union(y); !got1.equal(want1) || !got2.equal(want2) {
+			t.Errorf("%v.union(%v) = %v, %v; want %v, %v", x, y, got1, got2, want1, want2)
+		}
+	}
+}
+
+func TestTermIntersection(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ ∅",
+		"∅ ⊤ ∅",
+		"∅ int ∅",
+		"∅ ~int ∅",
+		"⊤ ⊤ ⊤",
+		"⊤ int int",
+		"⊤ ~int ~int",
+		"int int int",
+		"int ~int int",
+		"int string ∅",
+		"int ~string ∅",
+		"~int ~string ∅",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := testTerm(args[2])
+		if got := x.intersect(y); !got.equal(want) {
+			t.Errorf("%v.intersect(%v) = %v; want %v", x, y, got, want)
+		}
+		// intersect is symmetric
+		x, y = y, x
+		if got := x.intersect(y); !got.equal(want) {
+			t.Errorf("%v.intersect(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermIncludes(t *testing.T) {
+	for _, test := range []string{
+		"∅ int F",
+		"⊤ int T",
+		"int int T",
+		"~int int T",
+		"string int F",
+		"~string int F",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1]).typ
+		want := args[2] == "T"
+		if got := x.includes(y); got != want {
+			t.Errorf("%v.includes(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermSubsetOf(t *testing.T) {
+	for _, test := range []string{
+		"∅ ∅ T",
+		"⊤ ⊤ T",
+		"int int T",
+		"~int ~int T",
+		"∅ ⊤ T",
+		"∅ int T",
+		"∅ ~int T",
+		"⊤ int F",
+		"⊤ ~int F",
+		"int ~int T",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.subsetOf(y); got != want {
+			t.Errorf("%v.subsetOf(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
+
+func TestTermDisjoint(t *testing.T) {
+	for _, test := range []string{
+		"int int F",
+		"~int ~int F",
+		"int ~int F",
+		"int string T",
+		"int ~string T",
+		"~int ~string T",
+	} {
+		args := split(test, 3)
+		x := testTerm(args[0])
+		y := testTerm(args[1])
+		want := args[2] == "T"
+		if got := x.disjoint(y); got != want {
+			t.Errorf("%v.disjoint(%v) = %v; want %v", x, y, got, want)
+		}
+		// disjoint is symmetric
+		x, y = y, x
+		if got := x.disjoint(y); got != want {
+			t.Errorf("%v.disjoint(%v) = %v; want %v", x, y, got, want)
+		}
+	}
+}
diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
index 5185c33fcbf..a812ba6519a 100644
--- a/src/go/types/typexpr.go
+++ b/src/go/types/typexpr.go
@@ -12,8 +12,6 @@ import (
 	"go/constant"
 	"go/internal/typeparams"
 	"go/token"
-	"sort"
-	"strconv"
 	"strings"
 )
 
@@ -29,13 +27,24 @@ func (check *Checker) ident(x *operand, e *ast.Ident, def *Named, wantType bool)
 	// Note that we cannot use check.lookup here because the returned scope
 	// may be different from obj.Parent(). See also Scope.LookupParent doc.
 	scope, obj := check.scope.LookupParent(e.Name, check.pos)
-	if obj == nil {
+	switch obj {
+	case nil:
 		if e.Name == "_" {
-			check.errorf(e, _InvalidBlank, "cannot use _ as value or type")
+			check.error(e, _InvalidBlank, "cannot use _ as value or type")
 		} else {
 			check.errorf(e, _UndeclaredName, "undeclared name: %s", e.Name)
 		}
 		return
+	case universeAny, universeComparable:
+		if !check.allowVersion(check.pkg, 1, 18) {
+			check.errorf(e, _UndeclaredName, "undeclared name: %s (requires version go1.18 or later)", e.Name)
+			return
+		}
+		// If we allow "any" for general use, this if-statement can be removed (issue #33232).
+		if obj == universeAny {
+			check.error(e, _Todo, "cannot use any outside constraint position")
+			return
+		}
 	}
 	check.recordUse(e, obj)
 
@@ -58,7 +67,7 @@ func (check *Checker) ident(x *operand, e *ast.Ident, def *Named, wantType bool)
 	// If so, mark the respective package as used.
 	// (This code is only needed for dot-imports. Without them,
 	// we only have to mark variables, see *Var case below).
-	if pkgName := check.dotImportMap[dotImportKey{scope, obj}]; pkgName != nil {
+	if pkgName := check.dotImportMap[dotImportKey{scope, obj.Name()}]; pkgName != nil {
 		pkgName.used = true
 	}
 
@@ -142,12 +151,12 @@ func (check *Checker) ordinaryType(pos positioner, typ Type) {
 	// type-checking.
 	check.later(func() {
 		if t := asInterface(typ); t != nil {
-			check.completeInterface(pos.Pos(), t) // TODO(gri) is this the correct position?
-			if t.allTypes != nil {
-				check.softErrorf(pos, _Todo, "interface contains type constraints (%s)", t.allTypes)
+			tset := computeTypeSet(check, pos.Pos(), t) // TODO(gri) is this the correct position?
+			if tset.types != nil {
+				check.softErrorf(pos, _Todo, "interface contains type constraints (%s)", tset.types)
 				return
 			}
-			if t._IsComparable() {
+			if tset.IsComparable() {
 				check.softErrorf(pos, _Todo, "interface is (or embeds) comparable")
 			}
 		}
@@ -194,205 +203,6 @@ func (check *Checker) genericType(e ast.Expr, reportErr bool) Type {
 	return typ
 }
 
-// isubst returns an x with identifiers substituted per the substitution map smap.
-// isubst only handles the case of (valid) method receiver type expressions correctly.
-func isubst(x ast.Expr, smap map[*ast.Ident]*ast.Ident) ast.Expr {
-	switch n := x.(type) {
-	case *ast.Ident:
-		if alt := smap[n]; alt != nil {
-			return alt
-		}
-	case *ast.StarExpr:
-		X := isubst(n.X, smap)
-		if X != n.X {
-			new := *n
-			new.X = X
-			return &new
-		}
-	case *ast.IndexExpr:
-		elems := typeparams.UnpackExpr(n.Index)
-		var newElems []ast.Expr
-		for i, elem := range elems {
-			new := isubst(elem, smap)
-			if new != elem {
-				if newElems == nil {
-					newElems = make([]ast.Expr, len(elems))
-					copy(newElems, elems)
-				}
-				newElems[i] = new
-			}
-		}
-		if newElems != nil {
-			index := typeparams.PackExpr(newElems)
-			new := *n
-			new.Index = index
-			return &new
-		}
-	case *ast.ParenExpr:
-		return isubst(n.X, smap) // no need to keep parentheses
-	default:
-		// Other receiver type expressions are invalid.
-		// It's fine to ignore those here as they will
-		// be checked elsewhere.
-	}
-	return x
-}
-
-// funcType type-checks a function or method type.
-func (check *Checker) funcType(sig *Signature, recvPar *ast.FieldList, ftyp *ast.FuncType) {
-	check.openScope(ftyp, "function")
-	check.scope.isFunc = true
-	check.recordScope(ftyp, check.scope)
-	sig.scope = check.scope
-	defer check.closeScope()
-
-	var recvTyp ast.Expr // rewritten receiver type; valid if != nil
-	if recvPar != nil && len(recvPar.List) > 0 {
-		// collect generic receiver type parameters, if any
-		// - a receiver type parameter is like any other type parameter, except that it is declared implicitly
-		// - the receiver specification acts as local declaration for its type parameters, which may be blank
-		_, rname, rparams := check.unpackRecv(recvPar.List[0].Type, true)
-		if len(rparams) > 0 {
-			// Blank identifiers don't get declared and regular type-checking of the instantiated
-			// parameterized receiver type expression fails in Checker.collectParams of receiver.
-			// Identify blank type parameters and substitute each with a unique new identifier named
-			// "n_" (where n is the parameter index) and which cannot conflict with any user-defined
-			// name.
-			var smap map[*ast.Ident]*ast.Ident // substitution map from "_" to "n_" identifiers
-			for i, p := range rparams {
-				if p.Name == "_" {
-					new := *p
-					new.Name = fmt.Sprintf("%d_", i)
-					rparams[i] = &new // use n_ identifier instead of _ so it can be looked up
-					if smap == nil {
-						smap = make(map[*ast.Ident]*ast.Ident)
-					}
-					smap[p] = &new
-				}
-			}
-			if smap != nil {
-				// blank identifiers were found => use rewritten receiver type
-				recvTyp = isubst(recvPar.List[0].Type, smap)
-			}
-			sig.rparams = check.declareTypeParams(nil, rparams)
-			// determine receiver type to get its type parameters
-			// and the respective type parameter bounds
-			var recvTParams []*TypeName
-			if rname != nil {
-				// recv should be a Named type (otherwise an error is reported elsewhere)
-				// Also: Don't report an error via genericType since it will be reported
-				//       again when we type-check the signature.
-				// TODO(gri) maybe the receiver should be marked as invalid instead?
-				if recv := asNamed(check.genericType(rname, false)); recv != nil {
-					recvTParams = recv.tparams
-				}
-			}
-			// provide type parameter bounds
-			// - only do this if we have the right number (otherwise an error is reported elsewhere)
-			if len(sig.rparams) == len(recvTParams) {
-				// We have a list of *TypeNames but we need a list of Types.
-				list := make([]Type, len(sig.rparams))
-				for i, t := range sig.rparams {
-					list[i] = t.typ
-				}
-				smap := makeSubstMap(recvTParams, list)
-				for i, tname := range sig.rparams {
-					bound := recvTParams[i].typ.(*_TypeParam).bound
-					// bound is (possibly) parameterized in the context of the
-					// receiver type declaration. Substitute parameters for the
-					// current context.
-					// TODO(gri) should we assume now that bounds always exist?
-					//           (no bound == empty interface)
-					if bound != nil {
-						bound = check.subst(tname.pos, bound, smap)
-						tname.typ.(*_TypeParam).bound = bound
-					}
-				}
-			}
-		}
-	}
-
-	if tparams := typeparams.Get(ftyp); tparams != nil {
-		sig.tparams = check.collectTypeParams(tparams)
-		// Always type-check method type parameters but complain that they are not allowed.
-		// (A separate check is needed when type-checking interface method signatures because
-		// they don't have a receiver specification.)
-		if recvPar != nil {
-			check.errorf(tparams, _Todo, "methods cannot have type parameters")
-		}
-	}
-
-	// Value (non-type) parameters' scope starts in the function body. Use a temporary scope for their
-	// declarations and then squash that scope into the parent scope (and report any redeclarations at
-	// that time).
-	scope := NewScope(check.scope, token.NoPos, token.NoPos, "function body (temp. scope)")
-	recvList, _ := check.collectParams(scope, recvPar, recvTyp, false) // use rewritten receiver type, if any
-	params, variadic := check.collectParams(scope, ftyp.Params, nil, true)
-	results, _ := check.collectParams(scope, ftyp.Results, nil, false)
-	scope.squash(func(obj, alt Object) {
-		check.errorf(obj, _DuplicateDecl, "%s redeclared in this block", obj.Name())
-		check.reportAltDecl(alt)
-	})
-
-	if recvPar != nil {
-		// recv parameter list present (may be empty)
-		// spec: "The receiver is specified via an extra parameter section preceding the
-		// method name. That parameter section must declare a single parameter, the receiver."
-		var recv *Var
-		switch len(recvList) {
-		case 0:
-			// error reported by resolver
-			recv = NewParam(0, nil, "", Typ[Invalid]) // ignore recv below
-		default:
-			// more than one receiver
-			check.error(recvList[len(recvList)-1], _BadRecv, "method must have exactly one receiver")
-			fallthrough // continue with first receiver
-		case 1:
-			recv = recvList[0]
-		}
-
-		// TODO(gri) We should delay rtyp expansion to when we actually need the
-		//           receiver; thus all checks here should be delayed to later.
-		rtyp, _ := deref(recv.typ)
-		rtyp = expand(rtyp)
-
-		// spec: "The receiver type must be of the form T or *T where T is a type name."
-		// (ignore invalid types - error was reported before)
-		if t := rtyp; t != Typ[Invalid] {
-			var err string
-			if T := asNamed(t); T != nil {
-				// spec: "The type denoted by T is called the receiver base type; it must not
-				// be a pointer or interface type and it must be declared in the same package
-				// as the method."
-				if T.obj.pkg != check.pkg {
-					err = "type not defined in this package"
-				} else {
-					switch u := optype(T).(type) {
-					case *Basic:
-						// unsafe.Pointer is treated like a regular pointer
-						if u.kind == UnsafePointer {
-							err = "unsafe.Pointer"
-						}
-					case *Pointer, *Interface:
-						err = "pointer or interface type"
-					}
-				}
-			} else {
-				err = "basic or unnamed type"
-			}
-			if err != "" {
-				check.errorf(recv, _InvalidRecv, "invalid receiver %s (%s)", recv.typ, err)
-				// ok to continue
-			}
-		}
-		sig.recv = recv
-	}
-
-	sig.params = NewTuple(params...)
-	sig.results = NewTuple(results...)
-	sig.variadic = variadic
-}
-
 // goTypeName returns the Go type name for typ and
 // removes any occurrences of "types." from that name.
 func goTypeName(typ Type) string {
@@ -462,9 +272,10 @@ func (check *Checker) typInternal(e0 ast.Expr, def *Named) (T Type) {
 			check.errorf(&x, _NotAType, "%s is not a type", &x)
 		}
 
-	case *ast.IndexExpr:
-		exprs := typeparams.UnpackExpr(e.Index)
-		return check.instantiatedType(e.X, exprs, def)
+	case *ast.IndexExpr, *ast.MultiIndexExpr:
+		ix := typeparams.UnpackIndexExpr(e)
+		// TODO(rfindley): type instantiation should require go1.18
+		return check.instantiatedType(ix.X, ix.Indices, def)
 
 	case *ast.ParenExpr:
 		// Generic types must be instantiated before they can be used in any form.
@@ -600,43 +411,32 @@ func (check *Checker) typeOrNil(e ast.Expr) Type {
 	return Typ[Invalid]
 }
 
-func (check *Checker) instantiatedType(x ast.Expr, targs []ast.Expr, def *Named) Type {
-	b := check.genericType(x, true) // TODO(gri) what about cycles?
-	if b == Typ[Invalid] {
-		return b // error already reported
-	}
-	base := asNamed(b)
-	if base == nil {
-		unreachable() // should have been caught by genericType
+func (check *Checker) instantiatedType(x ast.Expr, targsx []ast.Expr, def *Named) Type {
+	base := check.genericType(x, true)
+	if base == Typ[Invalid] {
+		return base // error already reported
 	}
 
-	// create a new type instance rather than instantiate the type
-	// TODO(gri) should do argument number check here rather than
-	//           when instantiating the type?
-	typ := new(instance)
-	def.setUnderlying(typ)
-
-	typ.check = check
-	typ.pos = x.Pos()
-	typ.base = base
-
-	// evaluate arguments (always)
-	typ.targs = check.typeList(targs)
-	if typ.targs == nil {
+	// evaluate arguments
+	targs := check.typeList(targsx)
+	if targs == nil {
 		def.setUnderlying(Typ[Invalid]) // avoid later errors due to lazy instantiation
 		return Typ[Invalid]
 	}
 
-	// determine argument positions (for error reporting)
-	typ.poslist = make([]token.Pos, len(targs))
-	for i, arg := range targs {
-		typ.poslist[i] = arg.Pos()
+	// determine argument positions
+	posList := make([]token.Pos, len(targs))
+	for i, arg := range targsx {
+		posList[i] = arg.Pos()
 	}
 
+	typ := check.InstantiateLazy(x.Pos(), base, targs, posList, true)
+	def.setUnderlying(typ)
+
 	// make sure we check instantiation works at least once
 	// and that the resulting type is valid
 	check.later(func() {
-		t := typ.expand()
+		t := expand(typ)
 		check.validType(t, nil)
 	})
 
@@ -685,518 +485,3 @@ func (check *Checker) typeList(list []ast.Expr) []Type {
 	}
 	return res
 }
-
-// collectParams declares the parameters of list in scope and returns the corresponding
-// variable list. If type0 != nil, it is used instead of the first type in list.
-func (check *Checker) collectParams(scope *Scope, list *ast.FieldList, type0 ast.Expr, variadicOk bool) (params []*Var, variadic bool) {
-	if list == nil {
-		return
-	}
-
-	var named, anonymous bool
-	for i, field := range list.List {
-		ftype := field.Type
-		if i == 0 && type0 != nil {
-			ftype = type0
-		}
-		if t, _ := ftype.(*ast.Ellipsis); t != nil {
-			ftype = t.Elt
-			if variadicOk && i == len(list.List)-1 && len(field.Names) <= 1 {
-				variadic = true
-			} else {
-				check.softErrorf(t, _MisplacedDotDotDot, "can only use ... with final parameter in list")
-				// ignore ... and continue
-			}
-		}
-		typ := check.varType(ftype)
-		// The parser ensures that f.Tag is nil and we don't
-		// care if a constructed AST contains a non-nil tag.
-		if len(field.Names) > 0 {
-			// named parameter
-			for _, name := range field.Names {
-				if name.Name == "" {
-					check.invalidAST(name, "anonymous parameter")
-					// ok to continue
-				}
-				par := NewParam(name.Pos(), check.pkg, name.Name, typ)
-				check.declare(scope, name, par, scope.pos)
-				params = append(params, par)
-			}
-			named = true
-		} else {
-			// anonymous parameter
-			par := NewParam(ftype.Pos(), check.pkg, "", typ)
-			check.recordImplicit(field, par)
-			params = append(params, par)
-			anonymous = true
-		}
-	}
-
-	if named && anonymous {
-		check.invalidAST(list, "list contains both named and anonymous parameters")
-		// ok to continue
-	}
-
-	// For a variadic function, change the last parameter's type from T to []T.
-	// Since we type-checked T rather than ...T, we also need to retro-actively
-	// record the type for ...T.
-	if variadic {
-		last := params[len(params)-1]
-		last.typ = &Slice{elem: last.typ}
-		check.recordTypeAndValue(list.List[len(list.List)-1].Type, typexpr, last.typ, nil)
-	}
-
-	return
-}
-
-func (check *Checker) declareInSet(oset *objset, pos token.Pos, obj Object) bool {
-	if alt := oset.insert(obj); alt != nil {
-		check.errorf(atPos(pos), _DuplicateDecl, "%s redeclared", obj.Name())
-		check.reportAltDecl(alt)
-		return false
-	}
-	return true
-}
-
-func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, def *Named) {
-	var tlist *ast.Ident // "type" name of first entry in a type list declaration
-	var types []ast.Expr
-	for _, f := range iface.Methods.List {
-		if len(f.Names) > 0 {
-			// We have a method with name f.Names[0], or a type
-			// of a type list (name.Name == "type").
-			// (The parser ensures that there's only one method
-			// and we don't care if a constructed AST has more.)
-			name := f.Names[0]
-			if name.Name == "_" {
-				check.errorf(name, _BlankIfaceMethod, "invalid method name _")
-				continue // ignore
-			}
-
-			if name.Name == "type" {
-				// Always collect all type list entries, even from
-				// different type lists, under the assumption that
-				// the author intended to include all types.
-				types = append(types, f.Type)
-				if tlist != nil && tlist != name {
-					check.errorf(name, _Todo, "cannot have multiple type lists in an interface")
-				}
-				tlist = name
-				continue
-			}
-
-			typ := check.typ(f.Type)
-			sig, _ := typ.(*Signature)
-			if sig == nil {
-				if typ != Typ[Invalid] {
-					check.invalidAST(f.Type, "%s is not a method signature", typ)
-				}
-				continue // ignore
-			}
-
-			// Always type-check method type parameters but complain if they are not enabled.
-			// (This extra check is needed here because interface method signatures don't have
-			// a receiver specification.)
-			if sig.tparams != nil {
-				var at positioner = f.Type
-				if tparams := typeparams.Get(f.Type); tparams != nil {
-					at = tparams
-				}
-				check.errorf(at, _Todo, "methods cannot have type parameters")
-			}
-
-			// use named receiver type if available (for better error messages)
-			var recvTyp Type = ityp
-			if def != nil {
-				recvTyp = def
-			}
-			sig.recv = NewVar(name.Pos(), check.pkg, "", recvTyp)
-
-			m := NewFunc(name.Pos(), check.pkg, name.Name, sig)
-			check.recordDef(name, m)
-			ityp.methods = append(ityp.methods, m)
-		} else {
-			// We have an embedded type. completeInterface will
-			// eventually verify that we have an interface.
-			ityp.embeddeds = append(ityp.embeddeds, check.typ(f.Type))
-			check.posMap[ityp] = append(check.posMap[ityp], f.Type.Pos())
-		}
-	}
-
-	// type constraints
-	ityp.types = _NewSum(check.collectTypeConstraints(iface.Pos(), types))
-
-	if len(ityp.methods) == 0 && ityp.types == nil && len(ityp.embeddeds) == 0 {
-		// empty interface
-		ityp.allMethods = markComplete
-		return
-	}
-
-	// sort for API stability
-	sortMethods(ityp.methods)
-	sortTypes(ityp.embeddeds)
-
-	check.later(func() { check.completeInterface(iface.Pos(), ityp) })
-}
-
-func (check *Checker) completeInterface(pos token.Pos, ityp *Interface) {
-	if ityp.allMethods != nil {
-		return
-	}
-
-	// completeInterface may be called via the LookupFieldOrMethod,
-	// MissingMethod, Identical, or IdenticalIgnoreTags external API
-	// in which case check will be nil. In this case, type-checking
-	// must be finished and all interfaces should have been completed.
-	if check == nil {
-		panic("internal error: incomplete interface")
-	}
-
-	if trace {
-		// Types don't generally have position information.
-		// If we don't have a valid pos provided, try to use
-		// one close enough.
-		if !pos.IsValid() && len(ityp.methods) > 0 {
-			pos = ityp.methods[0].pos
-		}
-
-		check.trace(pos, "complete %s", ityp)
-		check.indent++
-		defer func() {
-			check.indent--
-			check.trace(pos, "=> %s (methods = %v, types = %v)", ityp, ityp.allMethods, ityp.allTypes)
-		}()
-	}
-
-	// An infinitely expanding interface (due to a cycle) is detected
-	// elsewhere (Checker.validType), so here we simply assume we only
-	// have valid interfaces. Mark the interface as complete to avoid
-	// infinite recursion if the validType check occurs later for some
-	// reason.
-	ityp.allMethods = markComplete
-
-	// Methods of embedded interfaces are collected unchanged; i.e., the identity
-	// of a method I.m's Func Object of an interface I is the same as that of
-	// the method m in an interface that embeds interface I. On the other hand,
-	// if a method is embedded via multiple overlapping embedded interfaces, we
-	// don't provide a guarantee which "original m" got chosen for the embedding
-	// interface. See also issue #34421.
-	//
-	// If we don't care to provide this identity guarantee anymore, instead of
-	// reusing the original method in embeddings, we can clone the method's Func
-	// Object and give it the position of a corresponding embedded interface. Then
-	// we can get rid of the mpos map below and simply use the cloned method's
-	// position.
-
-	var seen objset
-	var methods []*Func
-	mpos := make(map[*Func]token.Pos) // method specification or method embedding position, for good error messages
-	addMethod := func(pos token.Pos, m *Func, explicit bool) {
-		switch other := seen.insert(m); {
-		case other == nil:
-			methods = append(methods, m)
-			mpos[m] = pos
-		case explicit:
-			check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
-			check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
-		default:
-			// We have a duplicate method name in an embedded (not explicitly declared) method.
-			// Check method signatures after all types are computed (issue #33656).
-			// If we're pre-go1.14 (overlapping embeddings are not permitted), report that
-			// error here as well (even though we could do it eagerly) because it's the same
-			// error message.
-			check.later(func() {
-				if !check.allowVersion(m.pkg, 1, 14) || !check.identical(m.typ, other.Type()) {
-					check.errorf(atPos(pos), _DuplicateDecl, "duplicate method %s", m.name)
-					check.errorf(atPos(mpos[other.(*Func)]), _DuplicateDecl, "\tother declaration of %s", m.name) // secondary error, \t indented
-				}
-			})
-		}
-	}
-
-	for _, m := range ityp.methods {
-		addMethod(m.pos, m, true)
-	}
-
-	// collect types
-	allTypes := ityp.types
-
-	posList := check.posMap[ityp]
-	for i, typ := range ityp.embeddeds {
-		pos := posList[i] // embedding position
-		utyp := under(typ)
-		etyp := asInterface(utyp)
-		if etyp == nil {
-			if utyp != Typ[Invalid] {
-				var format string
-				if _, ok := utyp.(*_TypeParam); ok {
-					format = "%s is a type parameter, not an interface"
-				} else {
-					format = "%s is not an interface"
-				}
-				// TODO: correct error code.
-				check.errorf(atPos(pos), _InvalidIfaceEmbed, format, typ)
-			}
-			continue
-		}
-		check.completeInterface(pos, etyp)
-		for _, m := range etyp.allMethods {
-			addMethod(pos, m, false) // use embedding position pos rather than m.pos
-		}
-		allTypes = intersect(allTypes, etyp.allTypes)
-	}
-
-	if methods != nil {
-		sort.Sort(byUniqueMethodName(methods))
-		ityp.allMethods = methods
-	}
-	ityp.allTypes = allTypes
-}
-
-// intersect computes the intersection of the types x and y.
-// Note: A incomming nil type stands for the top type. A top
-// type result is returned as nil.
-func intersect(x, y Type) (r Type) {
-	defer func() {
-		if r == theTop {
-			r = nil
-		}
-	}()
-
-	switch {
-	case x == theBottom || y == theBottom:
-		return theBottom
-	case x == nil || x == theTop:
-		return y
-	case y == nil || x == theTop:
-		return x
-	}
-
-	xtypes := unpackType(x)
-	ytypes := unpackType(y)
-	// Compute the list rtypes which includes only
-	// types that are in both xtypes and ytypes.
-	// Quadratic algorithm, but good enough for now.
-	// TODO(gri) fix this
-	var rtypes []Type
-	for _, x := range xtypes {
-		if includes(ytypes, x) {
-			rtypes = append(rtypes, x)
-		}
-	}
-
-	if rtypes == nil {
-		return theBottom
-	}
-	return _NewSum(rtypes)
-}
-
-func sortTypes(list []Type) {
-	sort.Stable(byUniqueTypeName(list))
-}
-
-// byUniqueTypeName named type lists can be sorted by their unique type names.
-type byUniqueTypeName []Type
-
-func (a byUniqueTypeName) Len() int           { return len(a) }
-func (a byUniqueTypeName) Less(i, j int) bool { return sortName(a[i]) < sortName(a[j]) }
-func (a byUniqueTypeName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
-func sortName(t Type) string {
-	if named := asNamed(t); named != nil {
-		return named.obj.Id()
-	}
-	return ""
-}
-
-func sortMethods(list []*Func) {
-	sort.Sort(byUniqueMethodName(list))
-}
-
-func assertSortedMethods(list []*Func) {
-	if !debug {
-		panic("internal error: assertSortedMethods called outside debug mode")
-	}
-	if !sort.IsSorted(byUniqueMethodName(list)) {
-		panic("internal error: methods not sorted")
-	}
-}
-
-// byUniqueMethodName method lists can be sorted by their unique method names.
-type byUniqueMethodName []*Func
-
-func (a byUniqueMethodName) Len() int           { return len(a) }
-func (a byUniqueMethodName) Less(i, j int) bool { return a[i].Id() < a[j].Id() }
-func (a byUniqueMethodName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
-func (check *Checker) tag(t *ast.BasicLit) string {
-	if t != nil {
-		if t.Kind == token.STRING {
-			if val, err := strconv.Unquote(t.Value); err == nil {
-				return val
-			}
-		}
-		check.invalidAST(t, "incorrect tag syntax: %q", t.Value)
-	}
-	return ""
-}
-
-func (check *Checker) structType(styp *Struct, e *ast.StructType) {
-	list := e.Fields
-	if list == nil {
-		return
-	}
-
-	// struct fields and tags
-	var fields []*Var
-	var tags []string
-
-	// for double-declaration checks
-	var fset objset
-
-	// current field typ and tag
-	var typ Type
-	var tag string
-	add := func(ident *ast.Ident, embedded bool, pos token.Pos) {
-		if tag != "" && tags == nil {
-			tags = make([]string, len(fields))
-		}
-		if tags != nil {
-			tags = append(tags, tag)
-		}
-
-		name := ident.Name
-		fld := NewField(pos, check.pkg, name, typ, embedded)
-		// spec: "Within a struct, non-blank field names must be unique."
-		if name == "_" || check.declareInSet(&fset, pos, fld) {
-			fields = append(fields, fld)
-			check.recordDef(ident, fld)
-		}
-	}
-
-	// addInvalid adds an embedded field of invalid type to the struct for
-	// fields with errors; this keeps the number of struct fields in sync
-	// with the source as long as the fields are _ or have different names
-	// (issue #25627).
-	addInvalid := func(ident *ast.Ident, pos token.Pos) {
-		typ = Typ[Invalid]
-		tag = ""
-		add(ident, true, pos)
-	}
-
-	for _, f := range list.List {
-		typ = check.varType(f.Type)
-		tag = check.tag(f.Tag)
-		if len(f.Names) > 0 {
-			// named fields
-			for _, name := range f.Names {
-				add(name, false, name.Pos())
-			}
-		} else {
-			// embedded field
-			// spec: "An embedded type must be specified as a type name T or as a
-			// pointer to a non-interface type name *T, and T itself may not be a
-			// pointer type."
-			pos := f.Type.Pos()
-			name := embeddedFieldIdent(f.Type)
-			if name == nil {
-				// TODO(rFindley): using invalidAST here causes test failures (all
-				//                 errors should have codes). Clean this up.
-				check.errorf(f.Type, _Todo, "invalid AST: embedded field type %s has no name", f.Type)
-				name = ast.NewIdent("_")
-				name.NamePos = pos
-				addInvalid(name, pos)
-				continue
-			}
-			add(name, true, pos)
-
-			// Because we have a name, typ must be of the form T or *T, where T is the name
-			// of a (named or alias) type, and t (= deref(typ)) must be the type of T.
-			// We must delay this check to the end because we don't want to instantiate
-			// (via under(t)) a possibly incomplete type.
-
-			// for use in the closure below
-			embeddedTyp := typ
-			embeddedPos := f.Type
-
-			check.later(func() {
-				t, isPtr := deref(embeddedTyp)
-				switch t := optype(t).(type) {
-				case *Basic:
-					if t == Typ[Invalid] {
-						// error was reported before
-						return
-					}
-					// unsafe.Pointer is treated like a regular pointer
-					if t.kind == UnsafePointer {
-						check.errorf(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be unsafe.Pointer")
-					}
-				case *Pointer:
-					check.errorf(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be a pointer")
-				case *Interface:
-					if isPtr {
-						check.errorf(embeddedPos, _InvalidPtrEmbed, "embedded field type cannot be a pointer to an interface")
-					}
-				}
-			})
-		}
-	}
-
-	styp.fields = fields
-	styp.tags = tags
-}
-
-func embeddedFieldIdent(e ast.Expr) *ast.Ident {
-	switch e := e.(type) {
-	case *ast.Ident:
-		return e
-	case *ast.StarExpr:
-		// *T is valid, but **T is not
-		if _, ok := e.X.(*ast.StarExpr); !ok {
-			return embeddedFieldIdent(e.X)
-		}
-	case *ast.SelectorExpr:
-		return e.Sel
-	case *ast.IndexExpr:
-		return embeddedFieldIdent(e.X)
-	}
-	return nil // invalid embedded field
-}
-
-func (check *Checker) collectTypeConstraints(pos token.Pos, types []ast.Expr) []Type {
-	list := make([]Type, 0, len(types)) // assume all types are correct
-	for _, texpr := range types {
-		if texpr == nil {
-			check.invalidAST(atPos(pos), "missing type constraint")
-			continue
-		}
-		list = append(list, check.varType(texpr))
-	}
-
-	// Ensure that each type is only present once in the type list.  Types may be
-	// interfaces, which may not be complete yet. It's ok to do this check at the
-	// end because it's not a requirement for correctness of the code.
-	// Note: This is a quadratic algorithm, but type lists tend to be short.
-	check.later(func() {
-		for i, t := range list {
-			if t := asInterface(t); t != nil {
-				check.completeInterface(types[i].Pos(), t)
-			}
-			if includes(list[:i], t) {
-				check.softErrorf(types[i], _Todo, "duplicate type %s in type list", t)
-			}
-		}
-	})
-
-	return list
-}
-
-// includes reports whether typ is in list.
-func includes(list []Type, typ Type) bool {
-	for _, e := range list {
-		if Identical(typ, e) {
-			return true
-		}
-	}
-	return false
-}
diff --git a/src/go/types/unify.go b/src/go/types/unify.go
index db06e21cf72..90a5cf7c728 100644
--- a/src/go/types/unify.go
+++ b/src/go/types/unify.go
@@ -8,7 +8,7 @@ package types
 
 import (
 	"bytes"
-	"go/token"
+	"fmt"
 	"sort"
 )
 
@@ -38,7 +38,6 @@ import (
 // and the respective types inferred for each type parameter.
 // A unifier is created by calling newUnifier.
 type unifier struct {
-	check *Checker
 	exact bool
 	x, y  tparamsList // x and y must initialized via tparamsList.init
 	types []Type      // inferred types, shared by x and y
@@ -49,8 +48,8 @@ type unifier struct {
 // exactly. If exact is not set, a named type's underlying type
 // is considered if unification would fail otherwise, and the
 // direction of channels is ignored.
-func newUnifier(check *Checker, exact bool) *unifier {
-	u := &unifier{check: check, exact: exact}
+func newUnifier(exact bool) *unifier {
+	u := &unifier{exact: exact}
 	u.x.unifier = u
 	u.y.unifier = u
 	return u
@@ -100,7 +99,7 @@ func (d *tparamsList) init(tparams []*TypeName) {
 	}
 	if debug {
 		for i, tpar := range tparams {
-			assert(i == tpar.typ.(*_TypeParam).index)
+			assert(i == tpar.typ.(*TypeParam).index)
 		}
 	}
 	d.tparams = tparams
@@ -148,10 +147,17 @@ func (u *unifier) join(i, j int) bool {
 // If typ is a type parameter of d, index returns the type parameter index.
 // Otherwise, the result is < 0.
 func (d *tparamsList) index(typ Type) int {
-	if t, ok := typ.(*_TypeParam); ok {
-		if i := t.index; i < len(d.tparams) && d.tparams[i].typ == t {
-			return i
-		}
+	if tpar, ok := typ.(*TypeParam); ok {
+		return tparamIndex(d.tparams, tpar)
+	}
+	return -1
+}
+
+// If tpar is a type parameter in list, tparamIndex returns the type parameter index.
+// Otherwise, the result is < 0. tpar must not be nil.
+func tparamIndex(list []*TypeName, tpar *TypeParam) int {
+	if i := tpar.index; i < len(list) && list[i].typ == tpar {
+		return i
 	}
 	return -1
 }
@@ -352,25 +358,21 @@ func (u *unifier) nify(x, y Type, p *ifacePair) bool {
 				u.nify(x.results, y.results, p)
 		}
 
-	case *_Sum:
-		// This should not happen with the current internal use of sum types.
-		panic("type inference across sum types not implemented")
+	case *Union:
+		panic("unimplemented: unification with type sets described by types")
 
 	case *Interface:
 		// Two interface types are identical if they have the same set of methods with
 		// the same names and identical function types. Lower-case method names from
 		// different packages are always different. The order of the methods is irrelevant.
 		if y, ok := y.(*Interface); ok {
-			// If identical0 is called (indirectly) via an external API entry point
-			// (such as Identical, IdenticalIgnoreTags, etc.), check is nil. But in
-			// that case, interfaces are expected to be complete and lazy completion
-			// here is not needed.
-			if u.check != nil {
-				u.check.completeInterface(token.NoPos, x)
-				u.check.completeInterface(token.NoPos, y)
+			xset := x.typeSet()
+			yset := y.typeSet()
+			if !Identical(xset.types, yset.types) {
+				return false
 			}
-			a := x.allMethods
-			b := y.allMethods
+			a := xset.methods
+			b := yset.methods
 			if len(a) == len(b) {
 				// Interface types are the only types where cycles can occur
 				// that are not "terminated" via named types; and such cycles
@@ -448,21 +450,17 @@ func (u *unifier) nify(x, y Type, p *ifacePair) bool {
 			}
 		}
 
-	case *_TypeParam:
+	case *TypeParam:
 		// Two type parameters (which are not part of the type parameters of the
 		// enclosing type as those are handled in the beginning of this function)
 		// are identical if they originate in the same declaration.
 		return x == y
 
-	// case *instance:
-	//	unreachable since types are expanded
-
 	case nil:
 		// avoid a crash in case of nil type
 
 	default:
-		u.check.dump("### u.nify(%s, %s), u.x.tparams = %s", x, y, u.x.tparams)
-		unreachable()
+		panic(fmt.Sprintf("### u.nify(%s, %s), u.x.tparams = %s", x, y, u.x.tparams))
 	}
 
 	return false
diff --git a/src/go/types/union.go b/src/go/types/union.go
new file mode 100644
index 00000000000..a56f9d29f34
--- /dev/null
+++ b/src/go/types/union.go
@@ -0,0 +1,271 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package types
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+// ----------------------------------------------------------------------------
+// API
+
+// A Union represents a union of terms.
+type Union struct {
+	terms []*term
+}
+
+// NewUnion returns a new Union type with the given terms (types[i], tilde[i]).
+// The lengths of both arguments must match. An empty union represents the set
+// of no types.
+func NewUnion(types []Type, tilde []bool) *Union { return newUnion(types, tilde) }
+
+func (u *Union) IsEmpty() bool           { return len(u.terms) == 0 }
+func (u *Union) NumTerms() int           { return len(u.terms) }
+func (u *Union) Term(i int) (Type, bool) { t := u.terms[i]; return t.typ, t.tilde }
+
+func (u *Union) Underlying() Type { return u }
+func (u *Union) String() string   { return TypeString(u, nil) }
+
+// ----------------------------------------------------------------------------
+// Implementation
+
+var emptyUnion = new(Union)
+
+func newUnion(types []Type, tilde []bool) *Union {
+	assert(len(types) == len(tilde))
+	if len(types) == 0 {
+		return emptyUnion
+	}
+	t := new(Union)
+	t.terms = make([]*term, len(types))
+	for i, typ := range types {
+		t.terms[i] = &term{tilde[i], typ}
+	}
+	return t
+}
+
+// is reports whether f returns true for all terms of u.
+func (u *Union) is(f func(*term) bool) bool {
+	if u.IsEmpty() {
+		return false
+	}
+	for _, t := range u.terms {
+		if !f(t) {
+			return false
+		}
+	}
+	return true
+}
+
+// underIs reports whether f returned true for the underlying types of all terms of u.
+func (u *Union) underIs(f func(Type) bool) bool {
+	if u.IsEmpty() {
+		return false
+	}
+	for _, t := range u.terms {
+		if !f(under(t.typ)) {
+			return false
+		}
+	}
+	return true
+}
+
+func parseUnion(check *Checker, tlist []ast.Expr) Type {
+	var types []Type
+	var tilde []bool
+	for _, x := range tlist {
+		t, d := parseTilde(check, x)
+		if len(tlist) == 1 && !d {
+			return t // single type
+		}
+		types = append(types, t)
+		tilde = append(tilde, d)
+	}
+
+	// Ensure that each type is only present once in the type list.
+	// It's ok to do this check later because it's not a requirement
+	// for correctness of the code.
+	// Note: This is a quadratic algorithm, but unions tend to be short.
+	check.later(func() {
+		for i, t := range types {
+			t := expand(t)
+			if t == Typ[Invalid] {
+				continue
+			}
+
+			x := tlist[i]
+			pos := x.Pos()
+			// We may not know the position of x if it was a typechecker-
+			// introduced ~T term for a type list entry T. Use the position
+			// of T instead.
+			// TODO(rfindley) remove this test once we don't support type lists anymore
+			if !pos.IsValid() {
+				if op, _ := x.(*ast.UnaryExpr); op != nil {
+					pos = op.X.Pos()
+				}
+			}
+
+			u := under(t)
+			f, _ := u.(*Interface)
+			if tilde[i] {
+				if f != nil {
+					check.errorf(x, _Todo, "invalid use of ~ (%s is an interface)", t)
+					continue // don't report another error for t
+				}
+
+				if !Identical(u, t) {
+					check.errorf(x, _Todo, "invalid use of ~ (underlying type of %s is %s)", t, u)
+					continue // don't report another error for t
+				}
+			}
+
+			// Stand-alone embedded interfaces are ok and are handled by the single-type case
+			// in the beginning. Embedded interfaces with tilde are excluded above. If we reach
+			// here, we must have at least two terms in the union.
+			if f != nil && !f.typeSet().IsTypeSet() {
+				check.errorf(atPos(pos), _Todo, "cannot use %s in union (interface contains methods)", t)
+				continue // don't report another error for t
+			}
+
+			// Complain about duplicate entries a|a, but also a|~a, and ~a|~a.
+			// TODO(gri) We should also exclude myint|~int since myint is included in ~int.
+			if includes(types[:i], t) {
+				// TODO(rfindley) this currently doesn't print the ~ if present
+				check.softErrorf(atPos(pos), _Todo, "duplicate term %s in union element", t)
+			}
+		}
+	})
+
+	return newUnion(types, tilde)
+}
+
+func parseTilde(check *Checker, x ast.Expr) (typ Type, tilde bool) {
+	if op, _ := x.(*ast.UnaryExpr); op != nil && op.Op == token.TILDE {
+		x = op.X
+		tilde = true
+	}
+	typ = check.anyType(x)
+	// embedding stand-alone type parameters is not permitted (issue #47127).
+	if _, ok := under(typ).(*TypeParam); ok {
+		check.error(x, _Todo, "cannot embed a type parameter")
+		typ = Typ[Invalid]
+	}
+	return
+}
+
+// intersect computes the intersection of the types x and y,
+// A nil type stands for the set of all types; an empty union
+// stands for the set of no types.
+func intersect(x, y Type) (r Type) {
+	// If one of the types is nil (no restrictions)
+	// the result is the other type.
+	switch {
+	case x == nil:
+		return y
+	case y == nil:
+		return x
+	}
+
+	// Compute the terms which are in both x and y.
+	// TODO(gri) This is not correct as it may not always compute
+	//           the "largest" intersection. For instance, for
+	//           x = myInt|~int, y = ~int
+	//           we get the result myInt but we should get ~int.
+	xu, _ := x.(*Union)
+	yu, _ := y.(*Union)
+	switch {
+	case xu != nil && yu != nil:
+		return &Union{intersectTerms(xu.terms, yu.terms)}
+
+	case xu != nil:
+		if r, _ := xu.intersect(y, false); r != nil {
+			return y
+		}
+
+	case yu != nil:
+		if r, _ := yu.intersect(x, false); r != nil {
+			return x
+		}
+
+	default: // xu == nil && yu == nil
+		if Identical(x, y) {
+			return x
+		}
+	}
+
+	return emptyUnion
+}
+
+// includes reports whether typ is in list.
+func includes(list []Type, typ Type) bool {
+	for _, e := range list {
+		if Identical(typ, e) {
+			return true
+		}
+	}
+	return false
+}
+
+// intersect computes the intersection of the union u and term (y, yt)
+// and returns the intersection term, if any. Otherwise the result is
+// (nil, false).
+// TODO(gri) this needs to cleaned up/removed once we switch to lazy
+//           union type set computation.
+func (u *Union) intersect(y Type, yt bool) (Type, bool) {
+	under_y := under(y)
+	for _, x := range u.terms {
+		xt := x.tilde
+		// determine which types xx, yy to compare
+		xx := x.typ
+		if yt {
+			xx = under(xx)
+		}
+		yy := y
+		if xt {
+			yy = under_y
+		}
+		if Identical(xx, yy) {
+			//  T ∩  T =  T
+			//  T ∩ ~t =  T
+			// ~t ∩  T =  T
+			// ~t ∩ ~t = ~t
+			return xx, xt && yt
+		}
+	}
+	return nil, false
+}
+
+func identicalTerms(list1, list2 []*term) bool {
+	if len(list1) != len(list2) {
+		return false
+	}
+	// Every term in list1 must be in list2.
+	// Quadratic algorithm, but probably good enough for now.
+	// TODO(gri) we need a fast quick type ID/hash for all types.
+L:
+	for _, x := range list1 {
+		for _, y := range list2 {
+			if x.equal(y) {
+				continue L // x is in list2
+			}
+		}
+		return false
+	}
+	return true
+}
+
+func intersectTerms(list1, list2 []*term) (list []*term) {
+	// Quadratic algorithm, but good enough for now.
+	// TODO(gri) fix asymptotic performance
+	for _, x := range list1 {
+		for _, y := range list2 {
+			if r := x.intersect(y); r != nil {
+				list = append(list, r)
+			}
+		}
+	}
+	return
+}
diff --git a/src/go/types/universe.go b/src/go/types/universe.go
index 7c211fa6f7e..83c54c8cd33 100644
--- a/src/go/types/universe.go
+++ b/src/go/types/universe.go
@@ -21,11 +21,12 @@ var Universe *Scope
 var Unsafe *Package
 
 var (
-	universeIota  *Const
-	universeByte  *Basic // uint8 alias, but has name "byte"
-	universeRune  *Basic // int32 alias, but has name "rune"
-	universeAny   *Interface
-	universeError *Named
+	universeIota       Object
+	universeByte       Type // uint8 alias, but has name "byte"
+	universeRune       Type // int32 alias, but has name "rune"
+	universeAny        Object
+	universeError      Type
+	universeComparable Object
 )
 
 // Typ contains the predeclared *Basic types indexed by their
@@ -78,20 +79,30 @@ func defPredeclaredTypes() {
 		def(NewTypeName(token.NoPos, nil, t.name, t))
 	}
 
-	// any
-	// (Predeclared and entered into universe scope so we do all the
-	// usual checks; but removed again from scope later since it's
-	// only visible as constraint in a type parameter list.)
+	// type any = interface{}
 	def(NewTypeName(token.NoPos, nil, "any", &emptyInterface))
 
-	// Error has a nil package in its qualified name since it is in no package
+	// type error interface{ Error() string }
 	{
+		obj := NewTypeName(token.NoPos, nil, "error", nil)
+		obj.setColor(black)
 		res := NewVar(token.NoPos, nil, "", Typ[String])
-		sig := &Signature{results: NewTuple(res)}
+		sig := NewSignature(nil, nil, NewTuple(res), false)
 		err := NewFunc(token.NoPos, nil, "Error", sig)
-		typ := &Named{underlying: NewInterfaceType([]*Func{err}, nil).Complete()}
+		ityp := &Interface{obj, []*Func{err}, nil, nil, true, nil}
+		computeTypeSet(nil, token.NoPos, ityp) // prevent races due to lazy computation of tset
+		typ := NewNamed(obj, ityp, nil)
 		sig.recv = NewVar(token.NoPos, nil, "", typ)
-		def(NewTypeName(token.NoPos, nil, "error", typ))
+		def(obj)
+	}
+
+	// type comparable interface{ /* type set marked comparable */ }
+	{
+		obj := NewTypeName(token.NoPos, nil, "comparable", nil)
+		obj.setColor(black)
+		ityp := &Interface{obj, nil, nil, nil, true, &_TypeSet{true, nil, nil}}
+		NewNamed(obj, ityp, nil)
+		def(obj)
 	}
 }
 
@@ -201,33 +212,6 @@ func DefPredeclaredTestFuncs() {
 	def(newBuiltin(_Trace))
 }
 
-func defPredeclaredComparable() {
-	// The "comparable" interface can be imagined as defined like
-	//
-	// type comparable interface {
-	//         == () untyped bool
-	//         != () untyped bool
-	// }
-	//
-	// == and != cannot be user-declared but we can declare
-	// a magic method == and check for its presence when needed.
-
-	// Define interface { == () }. We don't care about the signature
-	// for == so leave it empty except for the receiver, which is
-	// set up later to match the usual interface method assumptions.
-	sig := new(Signature)
-	eql := NewFunc(token.NoPos, nil, "==", sig)
-	iface := NewInterfaceType([]*Func{eql}, nil).Complete()
-
-	// set up the defined type for the interface
-	obj := NewTypeName(token.NoPos, nil, "comparable", nil)
-	named := NewNamed(obj, iface, nil)
-	obj.color_ = black
-	sig.recv = NewVar(token.NoPos, nil, "", named) // complete == signature
-
-	def(obj)
-}
-
 func init() {
 	Universe = NewScope(nil, token.NoPos, token.NoPos, "universe")
 	Unsafe = NewPackage("unsafe", "unsafe")
@@ -237,16 +221,13 @@ func init() {
 	defPredeclaredConsts()
 	defPredeclaredNil()
 	defPredeclaredFuncs()
-	defPredeclaredComparable()
 
-	universeIota = Universe.Lookup("iota").(*Const)
-	universeByte = Universe.Lookup("byte").(*TypeName).typ.(*Basic)
-	universeRune = Universe.Lookup("rune").(*TypeName).typ.(*Basic)
-	universeAny = Universe.Lookup("any").(*TypeName).typ.(*Interface)
-	universeError = Universe.Lookup("error").(*TypeName).typ.(*Named)
-
-	// "any" is only visible as constraint in a type parameter list
-	delete(Universe.elems, "any")
+	universeIota = Universe.Lookup("iota")
+	universeByte = Universe.Lookup("byte").Type()
+	universeRune = Universe.Lookup("rune").Type()
+	universeAny = Universe.Lookup("any")
+	universeError = Universe.Lookup("error").Type()
+	universeComparable = Universe.Lookup("comparable")
 }
 
 // Objects with names containing blanks are internal and not entered into
diff --git a/src/image/draw/draw.go b/src/image/draw/draw.go
index 8f96aa2d180..13f66682938 100644
--- a/src/image/draw/draw.go
+++ b/src/image/draw/draw.go
@@ -23,6 +23,16 @@ type Image interface {
 	Set(x, y int, c color.Color)
 }
 
+// RGBA64Image extends both the Image and image.RGBA64Image interfaces with a
+// SetRGBA64 method to change a single pixel. SetRGBA64 is equivalent to
+// calling Set, but it can avoid allocations from converting concrete color
+// types to the color.Color interface type.
+type RGBA64Image interface {
+	image.RGBA64Image
+	Set(x, y int, c color.Color)
+	SetRGBA64(x, y int, c color.RGBA64)
+}
+
 // Quantizer produces a palette for an image.
 type Quantizer interface {
 	// Quantize appends up to cap(p) - len(p) colors to p and returns the
diff --git a/src/image/geom.go b/src/image/geom.go
index 78e9e49d4f6..e71aa611872 100644
--- a/src/image/geom.go
+++ b/src/image/geom.go
@@ -246,6 +246,14 @@ func (r Rectangle) At(x, y int) color.Color {
 	return color.Transparent
 }
 
+// RGBA64At implements the RGBA64Image interface.
+func (r Rectangle) RGBA64At(x, y int) color.RGBA64 {
+	if (Point{x, y}).In(r) {
+		return color.RGBA64{0xffff, 0xffff, 0xffff, 0xffff}
+	}
+	return color.RGBA64{}
+}
+
 // Bounds implements the Image interface.
 func (r Rectangle) Bounds() Rectangle {
 	return r
diff --git a/src/image/gif/reader.go b/src/image/gif/reader.go
index e580ab049e6..9e8268c86f3 100644
--- a/src/image/gif/reader.go
+++ b/src/image/gif/reader.go
@@ -116,7 +116,7 @@ type decoder struct {
 // consumed when checking that the blockReader is exhausted.
 //
 // To avoid the allocation of a bufio.Reader for the lzw Reader, blockReader
-// implements io.ReadByte and buffers blocks into the decoder's "tmp" buffer.
+// implements io.ByteReader and buffers blocks into the decoder's "tmp" buffer.
 type blockReader struct {
 	d    *decoder
 	i, j uint8 // d.tmp[i:j] contains the buffered bytes
diff --git a/src/image/image.go b/src/image/image.go
index 8adba96ab6e..930d9ac6c7b 100644
--- a/src/image/image.go
+++ b/src/image/image.go
@@ -45,6 +45,17 @@ type Image interface {
 	At(x, y int) color.Color
 }
 
+// RGBA64Image is an Image whose pixels can be converted directly to a
+// color.RGBA64.
+type RGBA64Image interface {
+	// RGBA64At returns the RGBA64 color of the pixel at (x, y). It is
+	// equivalent to calling At(x, y).RGBA() and converting the resulting
+	// 32-bit return values to a color.RGBA64, but it can avoid allocations
+	// from converting concrete color types to the color.Color interface type.
+	RGBA64At(x, y int) color.RGBA64
+	Image
+}
+
 // PalettedImage is an image whose colors may come from a limited palette.
 // If m is a PalettedImage and m.ColorModel() returns a color.Palette p,
 // then m.At(x, y) should be equivalent to p[m.ColorIndexAt(x, y)]. If m's
@@ -90,6 +101,24 @@ func (p *RGBA) At(x, y int) color.Color {
 	return p.RGBAAt(x, y)
 }
 
+func (p *RGBA) RGBA64At(x, y int) color.RGBA64 {
+	if !(Point{x, y}.In(p.Rect)) {
+		return color.RGBA64{}
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	r := uint16(s[0])
+	g := uint16(s[1])
+	b := uint16(s[2])
+	a := uint16(s[3])
+	return color.RGBA64{
+		(r << 8) | r,
+		(g << 8) | g,
+		(b << 8) | b,
+		(a << 8) | a,
+	}
+}
+
 func (p *RGBA) RGBAAt(x, y int) color.RGBA {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.RGBA{}
@@ -118,6 +147,18 @@ func (p *RGBA) Set(x, y int, c color.Color) {
 	s[3] = c1.A
 }
 
+func (p *RGBA) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(c.R >> 8)
+	s[1] = uint8(c.G >> 8)
+	s[2] = uint8(c.B >> 8)
+	s[3] = uint8(c.A >> 8)
+}
+
 func (p *RGBA) SetRGBA(x, y int, c color.RGBA) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -311,6 +352,11 @@ func (p *NRGBA) At(x, y int) color.Color {
 	return p.NRGBAAt(x, y)
 }
 
+func (p *NRGBA) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NRGBAAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NRGBA) NRGBAAt(x, y int) color.NRGBA {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.NRGBA{}
@@ -339,6 +385,24 @@ func (p *NRGBA) Set(x, y int, c color.Color) {
 	s[3] = c1.A
 }
 
+func (p *NRGBA) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+	if (a != 0) && (a != 0xffff) {
+		r = (r * 0xffff) / a
+		g = (g * 0xffff) / a
+		b = (b * 0xffff) / a
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(r >> 8)
+	s[1] = uint8(g >> 8)
+	s[2] = uint8(b >> 8)
+	s[3] = uint8(a >> 8)
+}
+
 func (p *NRGBA) SetNRGBA(x, y int, c color.NRGBA) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -415,6 +479,11 @@ func (p *NRGBA64) At(x, y int) color.Color {
 	return p.NRGBA64At(x, y)
 }
 
+func (p *NRGBA64) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NRGBA64At(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NRGBA64) NRGBA64At(x, y int) color.NRGBA64 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.NRGBA64{}
@@ -452,6 +521,28 @@ func (p *NRGBA64) Set(x, y int, c color.Color) {
 	s[7] = uint8(c1.A)
 }
 
+func (p *NRGBA64) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+	if (a != 0) && (a != 0xffff) {
+		r = (r * 0xffff) / a
+		g = (g * 0xffff) / a
+		b = (b * 0xffff) / a
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+8 : i+8] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(r >> 8)
+	s[1] = uint8(r)
+	s[2] = uint8(g >> 8)
+	s[3] = uint8(g)
+	s[4] = uint8(b >> 8)
+	s[5] = uint8(b)
+	s[6] = uint8(a >> 8)
+	s[7] = uint8(a)
+}
+
 func (p *NRGBA64) SetNRGBA64(x, y int, c color.NRGBA64) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -532,6 +623,12 @@ func (p *Alpha) At(x, y int) color.Color {
 	return p.AlphaAt(x, y)
 }
 
+func (p *Alpha) RGBA64At(x, y int) color.RGBA64 {
+	a := uint16(p.AlphaAt(x, y).A)
+	a |= a << 8
+	return color.RGBA64{a, a, a, a}
+}
+
 func (p *Alpha) AlphaAt(x, y int) color.Alpha {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Alpha{}
@@ -554,6 +651,14 @@ func (p *Alpha) Set(x, y int, c color.Color) {
 	p.Pix[i] = color.AlphaModel.Convert(c).(color.Alpha).A
 }
 
+func (p *Alpha) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(c.A >> 8)
+}
+
 func (p *Alpha) SetAlpha(x, y int, c color.Alpha) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -626,6 +731,11 @@ func (p *Alpha16) At(x, y int) color.Color {
 	return p.Alpha16At(x, y)
 }
 
+func (p *Alpha16) RGBA64At(x, y int) color.RGBA64 {
+	a := p.Alpha16At(x, y).A
+	return color.RGBA64{a, a, a, a}
+}
+
 func (p *Alpha16) Alpha16At(x, y int) color.Alpha16 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Alpha16{}
@@ -650,6 +760,15 @@ func (p *Alpha16) Set(x, y int, c color.Color) {
 	p.Pix[i+1] = uint8(c1.A)
 }
 
+func (p *Alpha16) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i+0] = uint8(c.A >> 8)
+	p.Pix[i+1] = uint8(c.A)
+}
+
 func (p *Alpha16) SetAlpha16(x, y int, c color.Alpha16) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -723,6 +842,12 @@ func (p *Gray) At(x, y int) color.Color {
 	return p.GrayAt(x, y)
 }
 
+func (p *Gray) RGBA64At(x, y int) color.RGBA64 {
+	gray := uint16(p.GrayAt(x, y).Y)
+	gray |= gray << 8
+	return color.RGBA64{gray, gray, gray, 0xffff}
+}
+
 func (p *Gray) GrayAt(x, y int) color.Gray {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Gray{}
@@ -745,6 +870,16 @@ func (p *Gray) Set(x, y int, c color.Color) {
 	p.Pix[i] = color.GrayModel.Convert(c).(color.Gray).Y
 }
 
+func (p *Gray) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	// This formula is the same as in color.grayModel.
+	gray := (19595*uint32(c.R) + 38470*uint32(c.G) + 7471*uint32(c.B) + 1<<15) >> 24
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(gray)
+}
+
 func (p *Gray) SetGray(x, y int, c color.Gray) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -804,6 +939,11 @@ func (p *Gray16) At(x, y int) color.Color {
 	return p.Gray16At(x, y)
 }
 
+func (p *Gray16) RGBA64At(x, y int) color.RGBA64 {
+	gray := p.Gray16At(x, y).Y
+	return color.RGBA64{gray, gray, gray, 0xffff}
+}
+
 func (p *Gray16) Gray16At(x, y int) color.Gray16 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Gray16{}
@@ -828,6 +968,17 @@ func (p *Gray16) Set(x, y int, c color.Color) {
 	p.Pix[i+1] = uint8(c1.Y)
 }
 
+func (p *Gray16) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	// This formula is the same as in color.gray16Model.
+	gray := (19595*uint32(c.R) + 38470*uint32(c.G) + 7471*uint32(c.B) + 1<<15) >> 16
+	i := p.PixOffset(x, y)
+	p.Pix[i+0] = uint8(gray >> 8)
+	p.Pix[i+1] = uint8(gray)
+}
+
 func (p *Gray16) SetGray16(x, y int, c color.Gray16) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -888,6 +1039,11 @@ func (p *CMYK) At(x, y int) color.Color {
 	return p.CMYKAt(x, y)
 }
 
+func (p *CMYK) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.CMYKAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *CMYK) CMYKAt(x, y int) color.CMYK {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.CMYK{}
@@ -916,6 +1072,19 @@ func (p *CMYK) Set(x, y int, c color.Color) {
 	s[3] = c1.K
 }
 
+func (p *CMYK) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	cc, mm, yy, kk := color.RGBToCMYK(uint8(c.R>>8), uint8(c.G>>8), uint8(c.B>>8))
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = cc
+	s[1] = mm
+	s[2] = yy
+	s[3] = kk
+}
+
 func (p *CMYK) SetCMYK(x, y int, c color.CMYK) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -988,6 +1157,26 @@ func (p *Paletted) At(x, y int) color.Color {
 	return p.Palette[p.Pix[i]]
 }
 
+func (p *Paletted) RGBA64At(x, y int) color.RGBA64 {
+	if len(p.Palette) == 0 {
+		return color.RGBA64{}
+	}
+	c := color.Color(nil)
+	if !(Point{x, y}.In(p.Rect)) {
+		c = p.Palette[0]
+	} else {
+		i := p.PixOffset(x, y)
+		c = p.Palette[p.Pix[i]]
+	}
+	r, g, b, a := c.RGBA()
+	return color.RGBA64{
+		uint16(r),
+		uint16(g),
+		uint16(b),
+		uint16(a),
+	}
+}
+
 // PixOffset returns the index of the first element of Pix that corresponds to
 // the pixel at (x, y).
 func (p *Paletted) PixOffset(x, y int) int {
@@ -1002,6 +1191,14 @@ func (p *Paletted) Set(x, y int, c color.Color) {
 	p.Pix[i] = uint8(p.Palette.Index(c))
 }
 
+func (p *Paletted) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(p.Palette.Index(c))
+}
+
 func (p *Paletted) ColorIndexAt(x, y int) uint8 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return 0
diff --git a/src/image/image_test.go b/src/image/image_test.go
index b9b9bfaa28c..7f41bcb6c70 100644
--- a/src/image/image_test.go
+++ b/src/image/image_test.go
@@ -6,6 +6,7 @@ package image
 
 import (
 	"image/color"
+	"image/color/palette"
 	"testing"
 )
 
@@ -191,6 +192,92 @@ func Test16BitsPerColorChannel(t *testing.T) {
 	}
 }
 
+func TestRGBA64Image(t *testing.T) {
+	// memset sets every element of s to v.
+	memset := func(s []byte, v byte) {
+		for i := range s {
+			s[i] = v
+		}
+	}
+
+	r := Rect(0, 0, 3, 2)
+	testCases := []Image{
+		NewAlpha(r),
+		NewAlpha16(r),
+		NewCMYK(r),
+		NewGray(r),
+		NewGray16(r),
+		NewNRGBA(r),
+		NewNRGBA64(r),
+		NewNYCbCrA(r, YCbCrSubsampleRatio444),
+		NewPaletted(r, palette.Plan9),
+		NewRGBA(r),
+		NewRGBA64(r),
+		NewUniform(color.RGBA64{}),
+		NewYCbCr(r, YCbCrSubsampleRatio444),
+		r,
+	}
+	for _, tc := range testCases {
+		switch tc := tc.(type) {
+		// Most of the concrete image types in the testCases implement the
+		// draw.RGBA64Image interface: they have a SetRGBA64 method. We use an
+		// interface literal here, instead of importing "image/draw", to avoid
+		// an import cycle.
+		//
+		// The YCbCr and NYCbCrA types are special-cased. Chroma subsampling
+		// means that setting one pixel can modify neighboring pixels. They
+		// don't have Set or SetRGBA64 methods because that side effect could
+		// be surprising. Here, we just memset the channel buffers instead.
+		//
+		// The Uniform and Rectangle types are also special-cased, as they
+		// don't have a Set or SetRGBA64 method.
+		case interface {
+			SetRGBA64(x, y int, c color.RGBA64)
+		}:
+			tc.SetRGBA64(1, 1, color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF})
+
+		case *NYCbCrA:
+			memset(tc.YCbCr.Y, 0x77)
+			memset(tc.YCbCr.Cb, 0x88)
+			memset(tc.YCbCr.Cr, 0x99)
+			memset(tc.A, 0xAA)
+
+		case *Uniform:
+			tc.C = color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF}
+
+		case *YCbCr:
+			memset(tc.Y, 0x77)
+			memset(tc.Cb, 0x88)
+			memset(tc.Cr, 0x99)
+
+		case Rectangle:
+			// No-op. Rectangle pixels' colors are immutable. They're always
+			// color.Opaque.
+
+		default:
+			t.Errorf("could not initialize pixels for %T", tc)
+			continue
+		}
+
+		// Check that RGBA64At(x, y) is equivalent to At(x, y).RGBA().
+		rgba64Image, ok := tc.(RGBA64Image)
+		if !ok {
+			t.Errorf("%T is not an RGBA64Image", tc)
+			continue
+		}
+		got := rgba64Image.RGBA64At(1, 1)
+		wantR, wantG, wantB, wantA := tc.At(1, 1).RGBA()
+		if (uint32(got.R) != wantR) || (uint32(got.G) != wantG) ||
+			(uint32(got.B) != wantB) || (uint32(got.A) != wantA) {
+			t.Errorf("%T:\ngot  (0x%04X, 0x%04X, 0x%04X, 0x%04X)\n"+
+				"want (0x%04X, 0x%04X, 0x%04X, 0x%04X)", tc,
+				got.R, got.G, got.B, got.A,
+				wantR, wantG, wantB, wantA)
+			continue
+		}
+	}
+}
+
 func BenchmarkAt(b *testing.B) {
 	for _, tc := range testImages {
 		b.Run(tc.name, func(b *testing.B) {
diff --git a/src/image/names.go b/src/image/names.go
index 8595a35014d..17b06588ac5 100644
--- a/src/image/names.go
+++ b/src/image/names.go
@@ -41,6 +41,11 @@ func (c *Uniform) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point
 
 func (c *Uniform) At(x, y int) color.Color { return c.C }
 
+func (c *Uniform) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := c.C.RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 // Opaque scans the entire image and reports whether it is fully opaque.
 func (c *Uniform) Opaque() bool {
 	_, _, _, a := c.C.RGBA()
diff --git a/src/image/ycbcr.go b/src/image/ycbcr.go
index fbdffe1bd1b..328b90d1525 100644
--- a/src/image/ycbcr.go
+++ b/src/image/ycbcr.go
@@ -71,6 +71,11 @@ func (p *YCbCr) At(x, y int) color.Color {
 	return p.YCbCrAt(x, y)
 }
 
+func (p *YCbCr) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.YCbCrAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *YCbCr) YCbCrAt(x, y int) color.YCbCr {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.YCbCr{}
@@ -210,6 +215,11 @@ func (p *NYCbCrA) At(x, y int) color.Color {
 	return p.NYCbCrAAt(x, y)
 }
 
+func (p *NYCbCrA) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NYCbCrAAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NYCbCrA) NYCbCrAAt(x, y int) color.NYCbCrA {
 	if !(Point{X: x, Y: y}.In(p.Rect)) {
 		return color.NYCbCrA{}
diff --git a/src/internal/abi/abi.go b/src/internal/abi/abi.go
index aaff9cece35..eadff248d99 100644
--- a/src/internal/abi/abi.go
+++ b/src/internal/abi/abi.go
@@ -4,7 +4,10 @@
 
 package abi
 
-import "unsafe"
+import (
+	"internal/goarch"
+	"unsafe"
+)
 
 // RegArgs is a struct that has space for each argument
 // and return value register on the current architecture.
@@ -33,6 +36,46 @@ type RegArgs struct {
 	ReturnIsPtr IntArgRegBitmap
 }
 
+// IntRegArgAddr returns a pointer inside of r.Ints[reg] that is appropriately
+// offset for an argument of size argSize.
+//
+// argSize must be non-zero, fit in a register, and a power-of-two.
+//
+// This method is a helper for dealing with the endianness of different CPU
+// architectures, since sub-word-sized arguments in big endian architectures
+// need to be "aligned" to the upper edge of the register to be interpreted
+// by the CPU correctly.
+func (r *RegArgs) IntRegArgAddr(reg int, argSize uintptr) unsafe.Pointer {
+	if argSize > goarch.PtrSize || argSize == 0 || argSize&(argSize-1) != 0 {
+		panic("invalid argSize")
+	}
+	offset := uintptr(0)
+	if goarch.BigEndian {
+		offset = goarch.PtrSize - argSize
+	}
+	return unsafe.Pointer(uintptr(unsafe.Pointer(&r.Ints[reg])) + offset)
+}
+
+// FloatRegArgAddr returns a pointer inside of r.Floats[reg] that is appropriately
+// offset for an argument of size argSize.
+//
+// argSize must be non-zero, fit in a register, and a power-of-two.
+//
+// This method is a helper for dealing with the endianness of different CPU
+// architectures, since sub-word-sized arguments in big endian architectures
+// need to be "aligned" to the upper edge of the register to be interpreted
+// by the CPU correctly.
+func (r *RegArgs) FloatRegArgAddr(reg int, argSize uintptr) unsafe.Pointer {
+	if argSize > EffectiveFloatRegSize || argSize == 0 || argSize&(argSize-1) != 0 {
+		panic("invalid argSize")
+	}
+	offset := uintptr(0)
+	if goarch.BigEndian {
+		offset = EffectiveFloatRegSize - argSize
+	}
+	return unsafe.Pointer(uintptr(unsafe.Pointer(&r.Floats[reg])) + offset)
+}
+
 // IntArgRegBitmap is a bitmap large enough to hold one bit per
 // integer argument/return register.
 type IntArgRegBitmap [(IntArgRegs + 7) / 8]uint8
diff --git a/src/internal/abi/abi_amd64.go b/src/internal/abi/abi_amd64.go
index aff71f6a58a..d3c56782231 100644
--- a/src/internal/abi/abi_amd64.go
+++ b/src/internal/abi/abi_amd64.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build goexperiment.regabireflect
-// +build goexperiment.regabireflect
-
 package abi
 
 const (
diff --git a/src/internal/abi/abi_arm64.go b/src/internal/abi/abi_arm64.go
new file mode 100644
index 00000000000..7544d7506ed
--- /dev/null
+++ b/src/internal/abi/abi_arm64.go
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build goexperiment.regabireflect
+// +build goexperiment.regabireflect
+
+package abi
+
+const (
+	// See abi_generic.go.
+
+	// R0 - R15.
+	IntArgRegs = 16
+
+	// F0 - F15.
+	FloatArgRegs = 16
+
+	EffectiveFloatRegSize = 8
+)
diff --git a/src/internal/abi/abi_generic.go b/src/internal/abi/abi_generic.go
index 69400f930fb..e8f94f805f5 100644
--- a/src/internal/abi/abi_generic.go
+++ b/src/internal/abi/abi_generic.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !goexperiment.regabireflect
-// +build !goexperiment.regabireflect
+//go:build !goexperiment.regabireflect && !amd64
+// +build !goexperiment.regabireflect,!amd64
 
 package abi
 
diff --git a/src/internal/buildcfg/exp.go b/src/internal/buildcfg/exp.go
index 2435a79dcec..384f2f96af1 100644
--- a/src/internal/buildcfg/exp.go
+++ b/src/internal/buildcfg/exp.go
@@ -6,7 +6,6 @@ package buildcfg
 
 import (
 	"fmt"
-	"os"
 	"reflect"
 	"strings"
 
@@ -18,20 +17,19 @@ import (
 //
 // (This is not necessarily the set of experiments the compiler itself
 // was built with.)
-var Experiment goexperiment.Flags = parseExperiments()
-
-var regabiSupported = GOARCH == "amd64" && (GOOS == "android" || GOOS == "linux" || GOOS == "darwin" || GOOS == "windows")
-
+//
 // experimentBaseline specifies the experiment flags that are enabled by
 // default in the current toolchain. This is, in effect, the "control"
 // configuration and any variation from this is an experiment.
-var experimentBaseline = goexperiment.Flags{
-	RegabiWrappers: regabiSupported,
-	RegabiG:        regabiSupported,
-	RegabiReflect:  regabiSupported,
-	RegabiDefer:    regabiSupported,
-	RegabiArgs:     regabiSupported,
-}
+var Experiment, experimentBaseline = func() (goexperiment.Flags, goexperiment.Flags) {
+	flags, baseline, err := ParseGOEXPERIMENT(GOOS, GOARCH, envOr("GOEXPERIMENT", defaultGOEXPERIMENT))
+	if err != nil {
+		Error = err
+	}
+	return flags, baseline
+}()
+
+const DefaultGOEXPERIMENT = defaultGOEXPERIMENT
 
 // FramePointerEnabled enables the use of platform conventions for
 // saving frame pointers.
@@ -42,16 +40,27 @@ var experimentBaseline = goexperiment.Flags{
 // Note: must agree with runtime.framepointer_enabled.
 var FramePointerEnabled = GOARCH == "amd64" || GOARCH == "arm64"
 
-func parseExperiments() goexperiment.Flags {
+// ParseGOEXPERIMENT parses a (GOOS, GOARCH, GOEXPERIMENT)
+// configuration tuple and returns the enabled and baseline experiment
+// flag sets.
+//
+// TODO(mdempsky): Move to internal/goexperiment.
+func ParseGOEXPERIMENT(goos, goarch, goexp string) (flags, baseline goexperiment.Flags, err error) {
+	regabiSupported := goarch == "amd64" || goarch == "arm64"
+
+	baseline = goexperiment.Flags{
+		RegabiWrappers: regabiSupported,
+		RegabiReflect:  regabiSupported,
+		RegabiArgs:     regabiSupported,
+	}
+
 	// Start with the statically enabled set of experiments.
-	flags := experimentBaseline
+	flags = baseline
 
 	// Pick up any changes to the baseline configuration from the
 	// GOEXPERIMENT environment. This can be set at make.bash time
 	// and overridden at build time.
-	env := envOr("GOEXPERIMENT", defaultGOEXPERIMENT)
-
-	if env != "" {
+	if goexp != "" {
 		// Create a map of known experiment names.
 		names := make(map[string]func(bool))
 		rv := reflect.ValueOf(&flags).Elem()
@@ -67,14 +76,12 @@ func parseExperiments() goexperiment.Flags {
 		// do the right thing.
 		names["regabi"] = func(v bool) {
 			flags.RegabiWrappers = v
-			flags.RegabiG = v
 			flags.RegabiReflect = v
-			flags.RegabiDefer = v
 			flags.RegabiArgs = v
 		}
 
 		// Parse names.
-		for _, f := range strings.Split(env, ",") {
+		for _, f := range strings.Split(goexp, ",") {
 			if f == "" {
 				continue
 			}
@@ -91,29 +98,29 @@ func parseExperiments() goexperiment.Flags {
 			}
 			set, ok := names[f]
 			if !ok {
-				fmt.Printf("unknown experiment %s\n", f)
-				os.Exit(2)
+				err = fmt.Errorf("unknown GOEXPERIMENT %s", f)
+				return
 			}
 			set(val)
 		}
 	}
 
-	// regabi is only supported on amd64.
-	if GOARCH != "amd64" {
-		flags.RegabiWrappers = false
-		flags.RegabiG = false
+	// regabi is always enabled on amd64.
+	if goarch == "amd64" {
+		flags.RegabiWrappers = true
+		flags.RegabiReflect = true
+		flags.RegabiArgs = true
+	}
+	// regabi is only supported on amd64 and arm64.
+	if goarch != "amd64" && goarch != "arm64" {
 		flags.RegabiReflect = false
-		flags.RegabiDefer = false
 		flags.RegabiArgs = false
 	}
 	// Check regabi dependencies.
-	if flags.RegabiG && !flags.RegabiWrappers {
-		Error = fmt.Errorf("GOEXPERIMENT regabig requires regabiwrappers")
+	if flags.RegabiArgs && !(flags.RegabiWrappers && flags.RegabiReflect) {
+		err = fmt.Errorf("GOEXPERIMENT regabiargs requires regabiwrappers,regabireflect")
 	}
-	if flags.RegabiArgs && !(flags.RegabiWrappers && flags.RegabiG && flags.RegabiReflect && flags.RegabiDefer) {
-		Error = fmt.Errorf("GOEXPERIMENT regabiargs requires regabiwrappers,regabig,regabireflect,regabidefer")
-	}
-	return flags
+	return
 }
 
 // expList returns the list of lower-cased experiment names for
@@ -165,3 +172,14 @@ func EnabledExperiments() []string {
 func AllExperiments() []string {
 	return expList(&Experiment, nil, true)
 }
+
+// UpdateExperiments updates the Experiment global based on a new GOARCH value.
+// This is only required for cmd/go, which can change GOARCH after
+// program startup due to use of "go env -w".
+func UpdateExperiments(goos, goarch, goexperiment string) {
+	var err error
+	Experiment, experimentBaseline, err = ParseGOEXPERIMENT(goos, goarch, goexperiment)
+	if err != nil {
+		Error = err
+	}
+}
diff --git a/src/internal/bytealg/compare_amd64.s b/src/internal/bytealg/compare_amd64.s
index 8295acb03a1..4ccaca5e87b 100644
--- a/src/internal/bytealg/compare_amd64.s
+++ b/src/internal/bytealg/compare_amd64.s
@@ -6,7 +6,6 @@
 #include "textflag.h"
 
 TEXT ·Compare(SB),NOSPLIT,$0-56
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = a_base (want in SI)
 	// BX = a_len  (want in BX)
 	// CX = a_cap  (unused)
@@ -15,17 +14,9 @@ TEXT ·Compare(SB),NOSPLIT,$0-56
 	// R8 = b_cap  (unused)
 	MOVQ	SI, DX
 	MOVQ	AX, SI
-#else
-	MOVQ	a_base+0(FP), SI
-	MOVQ	a_len+8(FP), BX
-	MOVQ	b_base+24(FP), DI
-	MOVQ	b_len+32(FP), DX
-	LEAQ	ret+48(FP), R9
-#endif
 	JMP	cmpbody<>(SB)
 
 TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = a_base (want in SI)
 	// BX = a_len  (want in BX)
 	// CX = b_base (want in DI)
@@ -33,13 +24,6 @@ TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
 	MOVQ	AX, SI
 	MOVQ	DI, DX
 	MOVQ	CX, DI
-#else
-	MOVQ	a_base+0(FP), SI
-	MOVQ	a_len+8(FP), BX
-	MOVQ	b_base+16(FP), DI
-	MOVQ	b_len+24(FP), DX
-	LEAQ	ret+32(FP), R9
-#endif
 	JMP	cmpbody<>(SB)
 
 // input:
@@ -47,12 +31,8 @@ TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
 //   DI = b
 //   BX = alen
 //   DX = blen
-#ifndef GOEXPERIMENT_regabiargs
-//   R9 = address of output word (stores -1/0/1 here)
-#else
 // output:
 //   AX = output (-1/0/1)
-#endif
 TEXT cmpbody<>(SB),NOSPLIT,$0-0
 	CMPQ	SI, DI
 	JEQ	allsame
@@ -100,9 +80,6 @@ diff16:
 	CMPB	CX, (DI)(BX*1)
 	SETHI	AX
 	LEAQ	-1(AX*2), AX	// convert 1/0 to +1/-1
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	AX, (R9)
-#endif
 	RET
 
 	// 0 through 16 bytes left, alen>=8, blen>=8
@@ -128,9 +105,6 @@ diff8:
 	SHRQ	CX, AX	// move a's bit to bottom
 	ANDQ	$1, AX	// mask bit
 	LEAQ	-1(AX*2), AX // 1/0 => +1/-1
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	AX, (R9)
-#endif
 	RET
 
 	// 0-7 bytes in common
@@ -169,9 +143,6 @@ di_finish:
 	SHRQ	CX, SI	// move a's bit to bottom
 	ANDQ	$1, SI	// mask bit
 	LEAQ	-1(SI*2), AX // 1/0 => +1/-1
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	AX, (R9)
-#endif
 	RET
 
 allsame:
@@ -181,9 +152,6 @@ allsame:
 	SETGT	AX	// 1 if alen > blen
 	SETEQ	CX	// 1 if alen == blen
 	LEAQ	-1(CX)(AX*2), AX	// 1,0,-1 result
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	AX, (R9)
-#endif
 	RET
 
 	// this works for >= 64 bytes of data.
diff --git a/src/internal/bytealg/compare_arm64.s b/src/internal/bytealg/compare_arm64.s
index 56d56f241eb..5a802072583 100644
--- a/src/internal/bytealg/compare_arm64.s
+++ b/src/internal/bytealg/compare_arm64.s
@@ -5,65 +5,88 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-TEXT ·Compare(SB),NOSPLIT|NOFRAME,$0-56
-	MOVD	a_base+0(FP), R2
-	MOVD	a_len+8(FP), R0
-	MOVD	b_base+24(FP), R3
-	MOVD	b_len+32(FP), R1
+TEXT ·Compare(SB),NOSPLIT|NOFRAME,$0-56
+#ifdef GOEXPERIMENT_regabiargs
+	// R0 = a_base (want in R0)
+	// R1 = a_len  (want in R1)
+	// R2 = a_cap  (unused)
+	// R3 = b_base (want in R2)
+	// R4 = b_len  (want in R3)
+	// R5 = b_cap  (unused)
+	MOVD	R3, R2
+	MOVD	R4, R3
+#else
+	MOVD	a_base+0(FP), R0
+	MOVD	a_len+8(FP), R1
+	MOVD	b_base+24(FP), R2
+	MOVD	b_len+32(FP), R3
 	MOVD	$ret+48(FP), R7
+#endif
 	B	cmpbody<>(SB)
 
-TEXT runtime·cmpstring(SB),NOSPLIT|NOFRAME,$0-40
-	MOVD	a_base+0(FP), R2
-	MOVD	a_len+8(FP), R0
-	MOVD	b_base+16(FP), R3
-	MOVD	b_len+24(FP), R1
+TEXT runtime·cmpstring(SB),NOSPLIT|NOFRAME,$0-40
+#ifdef GOEXPERIMENT_regabiargs
+	// R0 = a_base
+	// R1 = a_len
+	// R2 = b_base
+	// R3 = b_len
+#else
+	MOVD	a_base+0(FP), R0
+	MOVD	a_len+8(FP), R1
+	MOVD	b_base+16(FP), R2
+	MOVD	b_len+24(FP), R3
 	MOVD	$ret+32(FP), R7
+#endif
 	B	cmpbody<>(SB)
 
 // On entry:
-// R0 is the length of a
-// R1 is the length of b
-// R2 points to the start of a
-// R3 points to the start of b
+// R0 points to the start of a
+// R1 is the length of a
+// R2 points to the start of b
+// R3 is the length of b
+#ifndef GOEXPERIMENT_regabiargs
 // R7 points to return value (-1/0/1 will be written here)
+#endif
 //
 // On exit:
+#ifdef GOEXPERIMENT_regabiargs
+// R0 is the result
+#endif
 // R4, R5, R6, R8, R9 and R10 are clobbered
 TEXT cmpbody<>(SB),NOSPLIT|NOFRAME,$0-0
-	CMP	R2, R3
+	CMP	R0, R2
 	BEQ	samebytes         // same starting pointers; compare lengths
-	CMP	R0, R1
-	CSEL	LT, R1, R0, R6    // R6 is min(R0, R1)
+	CMP	R1, R3
+	CSEL	LT, R3, R1, R6    // R6 is min(R1, R3)
 
 	CBZ	R6, samebytes
 	BIC	$0xf, R6, R10
 	CBZ	R10, small        // length < 16
-	ADD	R2, R10           // end of chunk16
+	ADD	R0, R10           // end of chunk16
 	// length >= 16
 chunk16_loop:
-	LDP.P	16(R2), (R4, R8)
-	LDP.P	16(R3), (R5, R9)
+	LDP.P	16(R0), (R4, R8)
+	LDP.P	16(R2), (R5, R9)
 	CMP	R4, R5
 	BNE	cmp
 	CMP	R8, R9
 	BNE	cmpnext
-	CMP	R10, R2
+	CMP	R10, R0
 	BNE	chunk16_loop
 	AND	$0xf, R6, R6
 	CBZ	R6, samebytes
 	SUBS	$8, R6
 	BLT	tail
 	// the length of tail > 8 bytes
-	MOVD.P	8(R2), R4
-	MOVD.P	8(R3), R5
+	MOVD.P	8(R0), R4
+	MOVD.P	8(R2), R5
 	CMP	R4, R5
 	BNE	cmp
 	SUB	$8, R6
 	// compare last 8 bytes
 tail:
-	MOVD	(R2)(R6), R4
-	MOVD	(R3)(R6), R5
+	MOVD	(R0)(R6), R4
+	MOVD	(R2)(R6), R5
 	CMP	R4, R5
 	BEQ	samebytes
 cmp:
@@ -71,52 +94,56 @@ cmp:
 	REV	R5, R5
 	CMP	R4, R5
 ret:
-	MOVD	$1, R4
-	CNEG	HI, R4, R4
-	MOVD	R4, (R7)
+	MOVD	$1, R0
+	CNEG	HI, R0, R0
+#ifndef GOEXPERIMENT_regabiargs
+	MOVD	R0, (R7)
+#endif
 	RET
 small:
 	TBZ	$3, R6, lt_8
-	MOVD	(R2), R4
-	MOVD	(R3), R5
+	MOVD	(R0), R4
+	MOVD	(R2), R5
 	CMP	R4, R5
 	BNE	cmp
 	SUBS	$8, R6
 	BEQ	samebytes
+	ADD	$8, R0
 	ADD	$8, R2
-	ADD	$8, R3
 	SUB	$8, R6
 	B	tail
 lt_8:
 	TBZ	$2, R6, lt_4
-	MOVWU	(R2), R4
-	MOVWU	(R3), R5
+	MOVWU	(R0), R4
+	MOVWU	(R2), R5
 	CMPW	R4, R5
 	BNE	cmp
 	SUBS	$4, R6
 	BEQ	samebytes
+	ADD	$4, R0
 	ADD	$4, R2
-	ADD	$4, R3
 lt_4:
 	TBZ	$1, R6, lt_2
-	MOVHU	(R2), R4
-	MOVHU	(R3), R5
+	MOVHU	(R0), R4
+	MOVHU	(R2), R5
 	CMPW	R4, R5
 	BNE	cmp
+	ADD	$2, R0
 	ADD	$2, R2
-	ADD	$2, R3
 lt_2:
 	TBZ	$0, R6, samebytes
 one:
-	MOVBU	(R2), R4
-	MOVBU	(R3), R5
+	MOVBU	(R0), R4
+	MOVBU	(R2), R5
 	CMPW	R4, R5
 	BNE	ret
 samebytes:
-	CMP	R1, R0
-	CSET	NE, R4
-	CNEG	LO, R4, R4
-	MOVD	R4, (R7)
+	CMP	R3, R1
+	CSET	NE, R0
+	CNEG	LO, R0, R0
+#ifndef GOEXPERIMENT_regabiargs
+	MOVD	R0, (R7)
+#endif
 	RET
 cmpnext:
 	REV	R8, R4
diff --git a/src/internal/bytealg/compare_mips64x.s b/src/internal/bytealg/compare_mips64x.s
index 4f05fceaca5..b472e510bce 100644
--- a/src/internal/bytealg/compare_mips64x.s
+++ b/src/internal/bytealg/compare_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/compare_mipsx.s b/src/internal/bytealg/compare_mipsx.s
index 9ac5ba56877..dcc4916e567 100644
--- a/src/internal/bytealg/compare_mipsx.s
+++ b/src/internal/bytealg/compare_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/compare_ppc64x.s b/src/internal/bytealg/compare_ppc64x.s
index 7819da31cd0..83444fa8260 100644
--- a/src/internal/bytealg/compare_ppc64x.s
+++ b/src/internal/bytealg/compare_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/count_ppc64x.s b/src/internal/bytealg/count_ppc64x.s
index a64d7d792d0..94163cbd8a3 100644
--- a/src/internal/bytealg/count_ppc64x.s
+++ b/src/internal/bytealg/count_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64le || ppc64
 // +build ppc64le ppc64
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/equal_amd64.s b/src/internal/bytealg/equal_amd64.s
index 6f12d2a1690..dd46e2e0fdf 100644
--- a/src/internal/bytealg/equal_amd64.s
+++ b/src/internal/bytealg/equal_amd64.s
@@ -7,7 +7,6 @@
 
 // memequal(a, b unsafe.Pointer, size uintptr) bool
 TEXT runtime·memequal(SB),NOSPLIT,$0-25
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = a    (want in SI)
 	// BX = b    (want in DI)
 	// CX = size (want in BX)
@@ -20,22 +19,9 @@ neq:
 	MOVQ	BX, DI
 	MOVQ	CX, BX
 	JMP	memeqbody<>(SB)
-#else
-	MOVQ	a+0(FP), SI
-	MOVQ	b+8(FP), DI
-	CMPQ	SI, DI
-	JEQ	eq
-	MOVQ	size+16(FP), BX
-	LEAQ	ret+24(FP), AX
-	JMP	memeqbody<>(SB)
-eq:
-	MOVB	$1, ret+24(FP)
-	RET
-#endif
 
 // memequal_varlen(a, b unsafe.Pointer) bool
 TEXT runtime·memequal_varlen(SB),NOSPLIT,$0-17
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = a       (want in SI)
 	// BX = b       (want in DI)
 	// 8(DX) = size (want in BX)
@@ -48,29 +34,13 @@ neq:
 	MOVQ	BX, DI
 	MOVQ	8(DX), BX    // compiler stores size at offset 8 in the closure
 	JMP	memeqbody<>(SB)
-#else
-	MOVQ	a+0(FP), SI
-	MOVQ	b+8(FP), DI
-	CMPQ	SI, DI
-	JEQ	eq
-	MOVQ	8(DX), BX    // compiler stores size at offset 8 in the closure
-	LEAQ	ret+16(FP), AX
-	JMP	memeqbody<>(SB)
-eq:
-	MOVB	$1, ret+16(FP)
-	RET
-#endif
 
 // Input:
 //   a in SI
 //   b in DI
 //   count in BX
-#ifndef GOEXPERIMENT_regabiargs
-//   address of result byte in AX
-#else
 // Output:
 //   result in AX
-#endif
 TEXT memeqbody<>(SB),NOSPLIT,$0-0
 	CMPQ	BX, $8
 	JB	small
@@ -104,11 +74,7 @@ hugeloop:
 	SUBQ	$64, BX
 	CMPL	DX, $0xffff
 	JEQ	hugeloop
-#ifdef GOEXPERIMENT_regabiargs
 	XORQ	AX, AX	// return 0
-#else
-	MOVB	$0, (AX)
-#endif
 	RET
 
 	// 64 bytes at a time using ymm registers
@@ -129,11 +95,7 @@ hugeloop_avx2:
 	CMPL	DX, $0xffffffff
 	JEQ	hugeloop_avx2
 	VZEROUPPER
-#ifdef GOEXPERIMENT_regabiargs
 	XORQ	AX, AX	// return 0
-#else
-	MOVB	$0, (AX)
-#endif
 	RET
 
 bigloop_avx2:
@@ -150,11 +112,7 @@ bigloop:
 	SUBQ	$8, BX
 	CMPQ	CX, DX
 	JEQ	bigloop
-#ifdef GOEXPERIMENT_regabiargs
 	XORQ	AX, AX	// return 0
-#else
-	MOVB	$0, (AX)
-#endif
 	RET
 
 	// remaining 0-8 bytes
@@ -162,11 +120,7 @@ leftover:
 	MOVQ	-8(SI)(BX*1), CX
 	MOVQ	-8(DI)(BX*1), DX
 	CMPQ	CX, DX
-#ifdef GOEXPERIMENT_regabiargs
 	SETEQ	AX
-#else
-	SETEQ	(AX)
-#endif
 	RET
 
 small:
@@ -201,10 +155,5 @@ di_finish:
 	SUBQ	SI, DI
 	SHLQ	CX, DI
 equal:
-#ifdef GOEXPERIMENT_regabiargs
 	SETEQ	AX
-#else
-	SETEQ	(AX)
-#endif
 	RET
-
diff --git a/src/internal/bytealg/equal_arm64.s b/src/internal/bytealg/equal_arm64.s
index 01aa7b7b7aa..cf5cf54e597 100644
--- a/src/internal/bytealg/equal_arm64.s
+++ b/src/internal/bytealg/equal_arm64.s
@@ -6,58 +6,70 @@
 #include "textflag.h"
 
 // memequal(a, b unsafe.Pointer, size uintptr) bool
-TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-25
-	MOVD	size+16(FP), R1
+TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-25
+#ifndef GOEXPERIMENT_regabiargs
+	MOVD	size+16(FP), R2
+#endif
 	// short path to handle 0-byte case
-	CBZ	R1, equal
+	CBZ	R2, equal
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	a+0(FP), R0
-	MOVD	b+8(FP), R2
+	MOVD	b+8(FP), R1
 	MOVD	$ret+24(FP), R8
+#endif
 	B	memeqbody<>(SB)
 equal:
 	MOVD	$1, R0
+#ifndef GOEXPERIMENT_regabiargs
 	MOVB	R0, ret+24(FP)
+#endif
 	RET
 
 // memequal_varlen(a, b unsafe.Pointer) bool
-TEXT runtime·memequal_varlen(SB),NOSPLIT,$40-17
-	MOVD	a+0(FP), R3
-	MOVD	b+8(FP), R4
-	CMP	R3, R4
+TEXT runtime·memequal_varlen(SB),NOSPLIT,$0-17
+#ifndef GOEXPERIMENT_regabiargs
+	MOVD	a+0(FP), R0
+	MOVD	b+8(FP), R1
+#endif
+	CMP	R0, R1
 	BEQ	eq
-	MOVD	8(R26), R5    // compiler stores size at offset 8 in the closure
-	CBZ	R5, eq
-	MOVD	R3, 8(RSP)
-	MOVD	R4, 16(RSP)
-	MOVD	R5, 24(RSP)
-	BL	runtime·memequal(SB)
-	MOVBU	32(RSP), R3
-	MOVB	R3, ret+16(FP)
-	RET
+	MOVD	8(R26), R2    // compiler stores size at offset 8 in the closure
+	CBZ	R2, eq
+#ifndef GOEXPERIMENT_regabiargs
+	MOVD	$ret+16(FP), R8
+#endif
+	B	memeqbody<>(SB)
 eq:
-	MOVD	$1, R3
-	MOVB	R3, ret+16(FP)
+	MOVD	$1, R0
+#ifndef GOEXPERIMENT_regabiargs
+	MOVB	R0, ret+16(FP)
+#endif
 	RET
 
 // input:
 // R0: pointer a
-// R1: data len
-// R2: pointer b
+// R1: pointer b
+// R2: data len
+#ifdef GOEXPERIMENT_regabiargs
+// at return: result in R0
+#else
 // R8: address to put result
+#endif
+
 TEXT memeqbody<>(SB),NOSPLIT,$0
-	CMP	$1, R1
+	CMP	$1, R2
 	// handle 1-byte special case for better performance
 	BEQ	one
-	CMP	$16, R1
+	CMP	$16, R2
 	// handle specially if length < 16
 	BLO	tail
-	BIC	$0x3f, R1, R3
+	BIC	$0x3f, R2, R3
 	CBZ	R3, chunk16
 	// work with 64-byte chunks
 	ADD	R3, R0, R6	// end of chunks
 chunk64_loop:
 	VLD1.P	(R0), [V0.D2, V1.D2, V2.D2, V3.D2]
-	VLD1.P	(R2), [V4.D2, V5.D2, V6.D2, V7.D2]
+	VLD1.P	(R1), [V4.D2, V5.D2, V6.D2, V7.D2]
 	VCMEQ	V0.D2, V4.D2, V8.D2
 	VCMEQ	V1.D2, V5.D2, V9.D2
 	VCMEQ	V2.D2, V6.D2, V10.D2
@@ -71,66 +83,72 @@ chunk64_loop:
 	CBZ	R4, not_equal
 	CBZ	R5, not_equal
 	BNE	chunk64_loop
-	AND	$0x3f, R1, R1
-	CBZ	R1, equal
+	AND	$0x3f, R2, R2
+	CBZ	R2, equal
 chunk16:
 	// work with 16-byte chunks
-	BIC	$0xf, R1, R3
+	BIC	$0xf, R2, R3
 	CBZ	R3, tail
 	ADD	R3, R0, R6	// end of chunks
 chunk16_loop:
 	LDP.P	16(R0), (R4, R5)
-	LDP.P	16(R2), (R7, R9)
+	LDP.P	16(R1), (R7, R9)
 	EOR	R4, R7
 	CBNZ	R7, not_equal
 	EOR	R5, R9
 	CBNZ	R9, not_equal
 	CMP	R0, R6
 	BNE	chunk16_loop
-	AND	$0xf, R1, R1
-	CBZ	R1, equal
+	AND	$0xf, R2, R2
+	CBZ	R2, equal
 tail:
 	// special compare of tail with length < 16
-	TBZ	$3, R1, lt_8
+	TBZ	$3, R2, lt_8
 	MOVD	(R0), R4
-	MOVD	(R2), R5
+	MOVD	(R1), R5
 	EOR	R4, R5
 	CBNZ	R5, not_equal
-	SUB	$8, R1, R6	// offset of the last 8 bytes
+	SUB	$8, R2, R6	// offset of the last 8 bytes
 	MOVD	(R0)(R6), R4
-	MOVD	(R2)(R6), R5
+	MOVD	(R1)(R6), R5
 	EOR	R4, R5
 	CBNZ	R5, not_equal
 	B	equal
 lt_8:
-	TBZ	$2, R1, lt_4
+	TBZ	$2, R2, lt_4
 	MOVWU	(R0), R4
-	MOVWU	(R2), R5
+	MOVWU	(R1), R5
 	EOR	R4, R5
 	CBNZ	R5, not_equal
-	SUB	$4, R1, R6	// offset of the last 4 bytes
+	SUB	$4, R2, R6	// offset of the last 4 bytes
 	MOVWU	(R0)(R6), R4
-	MOVWU	(R2)(R6), R5
+	MOVWU	(R1)(R6), R5
 	EOR	R4, R5
 	CBNZ	R5, not_equal
 	B	equal
 lt_4:
-	TBZ	$1, R1, lt_2
+	TBZ	$1, R2, lt_2
 	MOVHU.P	2(R0), R4
-	MOVHU.P	2(R2), R5
+	MOVHU.P	2(R1), R5
 	CMP	R4, R5
 	BNE	not_equal
 lt_2:
-	TBZ	$0, R1, equal
+	TBZ	$0, R2, equal
 one:
 	MOVBU	(R0), R4
-	MOVBU	(R2), R5
+	MOVBU	(R1), R5
 	CMP	R4, R5
 	BNE	not_equal
 equal:
 	MOVD	$1, R0
+#ifndef GOEXPERIMENT_regabiargs
 	MOVB	R0, (R8)
+#endif
 	RET
 not_equal:
+#ifdef GOEXPERIMENT_regabiargs
+	MOVB	ZR, R0
+#else
 	MOVB	ZR, (R8)
+#endif
 	RET
diff --git a/src/internal/bytealg/equal_mips64x.s b/src/internal/bytealg/equal_mips64x.s
index 641e3ff06ca..c2f7d3997ed 100644
--- a/src/internal/bytealg/equal_mips64x.s
+++ b/src/internal/bytealg/equal_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/equal_mipsx.s b/src/internal/bytealg/equal_mipsx.s
index 1cabc70178b..11e5549e45a 100644
--- a/src/internal/bytealg/equal_mipsx.s
+++ b/src/internal/bytealg/equal_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/equal_ppc64x.s b/src/internal/bytealg/equal_ppc64x.s
index 18171eaedc9..5f0fea521b2 100644
--- a/src/internal/bytealg/equal_ppc64x.s
+++ b/src/internal/bytealg/equal_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/index_generic.go b/src/internal/bytealg/index_generic.go
index 287bdba4c68..0a6eb90d2d9 100644
--- a/src/internal/bytealg/index_generic.go
+++ b/src/internal/bytealg/index_generic.go
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// go:build !amd64 && !arm64 && !s390x && !ppc64le && !ppc64
 //go:build !amd64 && !arm64 && !s390x && !ppc64le && !ppc64
 // +build !amd64,!arm64,!s390x,!ppc64le,!ppc64
 
diff --git a/src/internal/bytealg/index_native.go b/src/internal/bytealg/index_native.go
index 75aff4b3cb0..9547a5d8e2a 100644
--- a/src/internal/bytealg/index_native.go
+++ b/src/internal/bytealg/index_native.go
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// go:build amd64 || arm64 || s390x || ppc64le || ppc64
 //go:build amd64 || arm64 || s390x || ppc64le || ppc64
 // +build amd64 arm64 s390x ppc64le ppc64
 
diff --git a/src/internal/bytealg/index_ppc64x.s b/src/internal/bytealg/index_ppc64x.s
index b7a1e2d7a22..3ed94421256 100644
--- a/src/internal/bytealg/index_ppc64x.s
+++ b/src/internal/bytealg/index_ppc64x.s
@@ -21,6 +21,7 @@
 // work is still needed for a big endian
 // implementation on power9.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/indexbyte_mips64x.s b/src/internal/bytealg/indexbyte_mips64x.s
index 6ebf0dee24b..0f377f5a4c9 100644
--- a/src/internal/bytealg/indexbyte_mips64x.s
+++ b/src/internal/bytealg/indexbyte_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/indexbyte_mipsx.s b/src/internal/bytealg/indexbyte_mipsx.s
index e44440b5f9e..bed015bbd6b 100644
--- a/src/internal/bytealg/indexbyte_mipsx.s
+++ b/src/internal/bytealg/indexbyte_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
diff --git a/src/internal/bytealg/indexbyte_ppc64x.s b/src/internal/bytealg/indexbyte_ppc64x.s
index 6e14e80af13..8e13c5a56e3 100644
--- a/src/internal/bytealg/indexbyte_ppc64x.s
+++ b/src/internal/bytealg/indexbyte_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
diff --git a/src/internal/cpu/cpu_x86.s b/src/internal/cpu/cpu_x86.s
index 93c712d784c..0df5da1cc74 100644
--- a/src/internal/cpu/cpu_x86.s
+++ b/src/internal/cpu/cpu_x86.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build 386 || amd64
 // +build 386 amd64
 
 #include "textflag.h"
diff --git a/src/internal/goarch/gengoarch.go b/src/internal/goarch/gengoarch.go
new file mode 100644
index 00000000000..af15518ad8b
--- /dev/null
+++ b/src/internal/goarch/gengoarch.go
@@ -0,0 +1,59 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var goarches []string
+
+func main() {
+	data, err := os.ReadFile("../../go/build/syslist.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	const goarchPrefix = `const goarchList = `
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.HasPrefix(line, goarchPrefix) {
+			text, err := strconv.Unquote(strings.TrimPrefix(line, goarchPrefix))
+			if err != nil {
+				log.Fatalf("parsing goarchList: %v", err)
+			}
+			goarches = strings.Fields(text)
+		}
+	}
+
+	for _, target := range goarches {
+		if target == "amd64p32" {
+			continue
+		}
+		var buf bytes.Buffer
+		fmt.Fprintf(&buf, "// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.\n\n")
+		fmt.Fprintf(&buf, "//go:build %s\n", target)
+		fmt.Fprintf(&buf, "// +build %s\n\n", target) // must explicitly include target for bootstrapping purposes
+		fmt.Fprintf(&buf, "package goarch\n\n")
+		fmt.Fprintf(&buf, "const GOARCH = `%s`\n\n", target)
+		for _, goarch := range goarches {
+			value := 0
+			if goarch == target {
+				value = 1
+			}
+			fmt.Fprintf(&buf, "const Is%s = %d\n", strings.Title(goarch), value)
+		}
+		err := os.WriteFile("zgoarch_"+target+".go", buf.Bytes(), 0666)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+}
diff --git a/src/runtime/internal/sys/arch.go b/src/internal/goarch/goarch.go
similarity index 74%
rename from src/runtime/internal/sys/arch.go
rename to src/internal/goarch/goarch.go
index 3c99a2f7da0..921f5a208fc 100644
--- a/src/runtime/internal/sys/arch.go
+++ b/src/internal/goarch/goarch.go
@@ -1,8 +1,15 @@
-// Copyright 2014 The Go Authors. All rights reserved.
+// Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+// package goarch contains GOARCH-specific constants.
+package goarch
+
+// The next line makes 'go generate' write the zgoarch*.go files with
+// per-arch information, including constants named $GOARCH for every
+// GOARCH. The constant is 1 on the current system, 0 otherwise; multiplying
+// by them is useful for defining GOARCH-specific constants.
+//go:generate go run gengoarch.go
 
 type ArchFamilyType int
 
@@ -23,14 +30,11 @@ const (
 // It is also the size of the machine's native word size (that is, 4 on 32-bit systems, 8 on 64-bit).
 const PtrSize = 4 << (^uintptr(0) >> 63)
 
-// AIX requires a larger stack for syscalls.
-const StackGuardMultiplier = StackGuardMultiplierDefault*(1-GoosAix) + 2*GoosAix
-
 // ArchFamily is the architecture family (AMD64, ARM, ...)
 const ArchFamily ArchFamilyType = _ArchFamily
 
 // BigEndian reports whether the architecture is big-endian.
-const BigEndian = GoarchArmbe|GoarchArm64be|GoarchMips|GoarchMips64|GoarchPpc|GoarchPpc64|GoarchS390|GoarchS390x|GoarchSparc|GoarchSparc64 == 1
+const BigEndian = IsArmbe|IsArm64be|IsMips|IsMips64|IsPpc|IsPpc64|IsS390|IsS390x|IsSparc|IsSparc64 == 1
 
 // DefaultPhysPageSize is the default physical page size.
 const DefaultPhysPageSize = _DefaultPhysPageSize
diff --git a/src/runtime/internal/sys/arch_386.go b/src/internal/goarch/goarch_386.go
similarity index 95%
rename from src/runtime/internal/sys/arch_386.go
rename to src/internal/goarch/goarch_386.go
index 1ebce3435e4..c6214217fcf 100644
--- a/src/runtime/internal/sys/arch_386.go
+++ b/src/internal/goarch/goarch_386.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = I386
diff --git a/src/runtime/internal/sys/arch_amd64.go b/src/internal/goarch/goarch_amd64.go
similarity index 95%
rename from src/runtime/internal/sys/arch_amd64.go
rename to src/internal/goarch/goarch_amd64.go
index 7f003d0f1d5..911e3e72421 100644
--- a/src/runtime/internal/sys/arch_amd64.go
+++ b/src/internal/goarch/goarch_amd64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = AMD64
diff --git a/src/runtime/internal/sys/arch_arm.go b/src/internal/goarch/goarch_arm.go
similarity index 95%
rename from src/runtime/internal/sys/arch_arm.go
rename to src/internal/goarch/goarch_arm.go
index ef2048bb71a..a6591713c82 100644
--- a/src/runtime/internal/sys/arch_arm.go
+++ b/src/internal/goarch/goarch_arm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = ARM
diff --git a/src/runtime/internal/sys/arch_arm64.go b/src/internal/goarch/goarch_arm64.go
similarity index 95%
rename from src/runtime/internal/sys/arch_arm64.go
rename to src/internal/goarch/goarch_arm64.go
index b9f2f7b1fe2..85d0b476391 100644
--- a/src/runtime/internal/sys/arch_arm64.go
+++ b/src/internal/goarch/goarch_arm64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = ARM64
diff --git a/src/runtime/internal/sys/arch_mips.go b/src/internal/goarch/goarch_mips.go
similarity index 95%
rename from src/runtime/internal/sys/arch_mips.go
rename to src/internal/goarch/goarch_mips.go
index 4cb0eebea7b..59f3995e2a5 100644
--- a/src/runtime/internal/sys/arch_mips.go
+++ b/src/internal/goarch/goarch_mips.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = MIPS
diff --git a/src/runtime/internal/sys/arch_mips64.go b/src/internal/goarch/goarch_mips64.go
similarity index 95%
rename from src/runtime/internal/sys/arch_mips64.go
rename to src/internal/goarch/goarch_mips64.go
index 57636ac4a4e..9e4f82797d4 100644
--- a/src/runtime/internal/sys/arch_mips64.go
+++ b/src/internal/goarch/goarch_mips64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = MIPS64
diff --git a/src/runtime/internal/sys/arch_mips64le.go b/src/internal/goarch/goarch_mips64le.go
similarity index 95%
rename from src/runtime/internal/sys/arch_mips64le.go
rename to src/internal/goarch/goarch_mips64le.go
index 57636ac4a4e..9e4f82797d4 100644
--- a/src/runtime/internal/sys/arch_mips64le.go
+++ b/src/internal/goarch/goarch_mips64le.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = MIPS64
diff --git a/src/runtime/internal/sys/arch_mipsle.go b/src/internal/goarch/goarch_mipsle.go
similarity index 95%
rename from src/runtime/internal/sys/arch_mipsle.go
rename to src/internal/goarch/goarch_mipsle.go
index 4240f5ce47b..3e6642bb863 100644
--- a/src/runtime/internal/sys/arch_mipsle.go
+++ b/src/internal/goarch/goarch_mipsle.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = MIPS
diff --git a/src/runtime/internal/sys/arch_ppc64.go b/src/internal/goarch/goarch_ppc64.go
similarity index 95%
rename from src/runtime/internal/sys/arch_ppc64.go
rename to src/internal/goarch/goarch_ppc64.go
index 1869213ce24..60cc846e6a3 100644
--- a/src/runtime/internal/sys/arch_ppc64.go
+++ b/src/internal/goarch/goarch_ppc64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = PPC64
diff --git a/src/runtime/internal/sys/arch_ppc64le.go b/src/internal/goarch/goarch_ppc64le.go
similarity index 95%
rename from src/runtime/internal/sys/arch_ppc64le.go
rename to src/internal/goarch/goarch_ppc64le.go
index 1869213ce24..60cc846e6a3 100644
--- a/src/runtime/internal/sys/arch_ppc64le.go
+++ b/src/internal/goarch/goarch_ppc64le.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = PPC64
diff --git a/src/runtime/internal/sys/arch_riscv64.go b/src/internal/goarch/goarch_riscv64.go
similarity index 95%
rename from src/runtime/internal/sys/arch_riscv64.go
rename to src/internal/goarch/goarch_riscv64.go
index 360d236e320..3b6da1e02fe 100644
--- a/src/runtime/internal/sys/arch_riscv64.go
+++ b/src/internal/goarch/goarch_riscv64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = RISCV64
diff --git a/src/runtime/internal/sys/arch_s390x.go b/src/internal/goarch/goarch_s390x.go
similarity index 95%
rename from src/runtime/internal/sys/arch_s390x.go
rename to src/internal/goarch/goarch_s390x.go
index e33e0b7f2b8..20c5705581e 100644
--- a/src/runtime/internal/sys/arch_s390x.go
+++ b/src/internal/goarch/goarch_s390x.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = S390X
diff --git a/src/runtime/internal/sys/arch_wasm.go b/src/internal/goarch/goarch_wasm.go
similarity index 95%
rename from src/runtime/internal/sys/arch_wasm.go
rename to src/internal/goarch/goarch_wasm.go
index ee919ff9e63..98618d6980e 100644
--- a/src/runtime/internal/sys/arch_wasm.go
+++ b/src/internal/goarch/goarch_wasm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package sys
+package goarch
 
 const (
 	_ArchFamily          = WASM
diff --git a/src/internal/goarch/zgoarch_386.go b/src/internal/goarch/zgoarch_386.go
new file mode 100644
index 00000000000..2395b809514
--- /dev/null
+++ b/src/internal/goarch/zgoarch_386.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build 386
+// +build 386
+
+package goarch
+
+const GOARCH = `386`
+
+const Is386 = 1
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_amd64.go b/src/internal/goarch/zgoarch_amd64.go
new file mode 100644
index 00000000000..c301d279c17
--- /dev/null
+++ b/src/internal/goarch/zgoarch_amd64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build amd64
+// +build amd64
+
+package goarch
+
+const GOARCH = `amd64`
+
+const Is386 = 0
+const IsAmd64 = 1
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_arm.go b/src/internal/goarch/zgoarch_arm.go
new file mode 100644
index 00000000000..4a5ff379995
--- /dev/null
+++ b/src/internal/goarch/zgoarch_arm.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build arm
+// +build arm
+
+package goarch
+
+const GOARCH = `arm`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 1
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_arm64.go b/src/internal/goarch/zgoarch_arm64.go
new file mode 100644
index 00000000000..840e280f94b
--- /dev/null
+++ b/src/internal/goarch/zgoarch_arm64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build arm64
+// +build arm64
+
+package goarch
+
+const GOARCH = `arm64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 1
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_arm64be.go b/src/internal/goarch/zgoarch_arm64be.go
new file mode 100644
index 00000000000..bdbe5faacf1
--- /dev/null
+++ b/src/internal/goarch/zgoarch_arm64be.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build arm64be
+// +build arm64be
+
+package goarch
+
+const GOARCH = `arm64be`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 1
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_armbe.go b/src/internal/goarch/zgoarch_armbe.go
new file mode 100644
index 00000000000..36be514a0b4
--- /dev/null
+++ b/src/internal/goarch/zgoarch_armbe.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build armbe
+// +build armbe
+
+package goarch
+
+const GOARCH = `armbe`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 1
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_loong64.go b/src/internal/goarch/zgoarch_loong64.go
new file mode 100644
index 00000000000..9465cf5bf5d
--- /dev/null
+++ b/src/internal/goarch/zgoarch_loong64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build loong64
+// +build loong64
+
+package goarch
+
+const GOARCH = `loong64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 1
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mips.go b/src/internal/goarch/zgoarch_mips.go
new file mode 100644
index 00000000000..e1458c0485e
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mips.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mips
+// +build mips
+
+package goarch
+
+const GOARCH = `mips`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 1
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mips64.go b/src/internal/goarch/zgoarch_mips64.go
new file mode 100644
index 00000000000..7de345e3219
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mips64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mips64
+// +build mips64
+
+package goarch
+
+const GOARCH = `mips64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 1
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mips64le.go b/src/internal/goarch/zgoarch_mips64le.go
new file mode 100644
index 00000000000..96b1c3c021c
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mips64le.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mips64le
+// +build mips64le
+
+package goarch
+
+const GOARCH = `mips64le`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 1
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mips64p32.go b/src/internal/goarch/zgoarch_mips64p32.go
new file mode 100644
index 00000000000..91d1f3c4df8
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mips64p32.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mips64p32
+// +build mips64p32
+
+package goarch
+
+const GOARCH = `mips64p32`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 1
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mips64p32le.go b/src/internal/goarch/zgoarch_mips64p32le.go
new file mode 100644
index 00000000000..18f2ef2347b
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mips64p32le.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mips64p32le
+// +build mips64p32le
+
+package goarch
+
+const GOARCH = `mips64p32le`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 1
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_mipsle.go b/src/internal/goarch/zgoarch_mipsle.go
new file mode 100644
index 00000000000..4551de1a325
--- /dev/null
+++ b/src/internal/goarch/zgoarch_mipsle.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build mipsle
+// +build mipsle
+
+package goarch
+
+const GOARCH = `mipsle`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 1
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_ppc.go b/src/internal/goarch/zgoarch_ppc.go
new file mode 100644
index 00000000000..ffed58c2e51
--- /dev/null
+++ b/src/internal/goarch/zgoarch_ppc.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build ppc
+// +build ppc
+
+package goarch
+
+const GOARCH = `ppc`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 1
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_ppc64.go b/src/internal/goarch/zgoarch_ppc64.go
new file mode 100644
index 00000000000..c369c741664
--- /dev/null
+++ b/src/internal/goarch/zgoarch_ppc64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build ppc64
+// +build ppc64
+
+package goarch
+
+const GOARCH = `ppc64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 1
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_ppc64le.go b/src/internal/goarch/zgoarch_ppc64le.go
new file mode 100644
index 00000000000..de5bae2a810
--- /dev/null
+++ b/src/internal/goarch/zgoarch_ppc64le.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build ppc64le
+// +build ppc64le
+
+package goarch
+
+const GOARCH = `ppc64le`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 1
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_riscv.go b/src/internal/goarch/zgoarch_riscv.go
new file mode 100644
index 00000000000..07c9d81b397
--- /dev/null
+++ b/src/internal/goarch/zgoarch_riscv.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build riscv
+// +build riscv
+
+package goarch
+
+const GOARCH = `riscv`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 1
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_riscv64.go b/src/internal/goarch/zgoarch_riscv64.go
new file mode 100644
index 00000000000..24e6ef3fdf4
--- /dev/null
+++ b/src/internal/goarch/zgoarch_riscv64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build riscv64
+// +build riscv64
+
+package goarch
+
+const GOARCH = `riscv64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 1
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_s390.go b/src/internal/goarch/zgoarch_s390.go
new file mode 100644
index 00000000000..429206d653a
--- /dev/null
+++ b/src/internal/goarch/zgoarch_s390.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build s390
+// +build s390
+
+package goarch
+
+const GOARCH = `s390`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 1
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_s390x.go b/src/internal/goarch/zgoarch_s390x.go
new file mode 100644
index 00000000000..0c590052164
--- /dev/null
+++ b/src/internal/goarch/zgoarch_s390x.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build s390x
+// +build s390x
+
+package goarch
+
+const GOARCH = `s390x`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 1
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_sparc.go b/src/internal/goarch/zgoarch_sparc.go
new file mode 100644
index 00000000000..83a356e4c7a
--- /dev/null
+++ b/src/internal/goarch/zgoarch_sparc.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build sparc
+// +build sparc
+
+package goarch
+
+const GOARCH = `sparc`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 1
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_sparc64.go b/src/internal/goarch/zgoarch_sparc64.go
new file mode 100644
index 00000000000..7c9d40986ec
--- /dev/null
+++ b/src/internal/goarch/zgoarch_sparc64.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build sparc64
+// +build sparc64
+
+package goarch
+
+const GOARCH = `sparc64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 1
+const IsWasm = 0
diff --git a/src/internal/goarch/zgoarch_wasm.go b/src/internal/goarch/zgoarch_wasm.go
new file mode 100644
index 00000000000..5aac1dfc479
--- /dev/null
+++ b/src/internal/goarch/zgoarch_wasm.go
@@ -0,0 +1,33 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build wasm
+// +build wasm
+
+package goarch
+
+const GOARCH = `wasm`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 1
diff --git a/src/internal/goexperiment/exp_regabi_off.go b/src/internal/goexperiment/exp_regabi_off.go
deleted file mode 100644
index 5d8823843d9..00000000000
--- a/src/internal/goexperiment/exp_regabi_off.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build !goexperiment.regabi
-// +build !goexperiment.regabi
-
-package goexperiment
-
-const Regabi = false
-const RegabiInt = 0
diff --git a/src/internal/goexperiment/exp_regabi_on.go b/src/internal/goexperiment/exp_regabi_on.go
deleted file mode 100644
index c08d58e9b2a..00000000000
--- a/src/internal/goexperiment/exp_regabi_on.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build goexperiment.regabi
-// +build goexperiment.regabi
-
-package goexperiment
-
-const Regabi = true
-const RegabiInt = 1
diff --git a/src/internal/goexperiment/exp_regabidefer_off.go b/src/internal/goexperiment/exp_regabidefer_off.go
deleted file mode 100644
index b47c0c2cf55..00000000000
--- a/src/internal/goexperiment/exp_regabidefer_off.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build !goexperiment.regabidefer
-// +build !goexperiment.regabidefer
-
-package goexperiment
-
-const RegabiDefer = false
-const RegabiDeferInt = 0
diff --git a/src/internal/goexperiment/exp_regabidefer_on.go b/src/internal/goexperiment/exp_regabidefer_on.go
deleted file mode 100644
index bbf2f6c69be..00000000000
--- a/src/internal/goexperiment/exp_regabidefer_on.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build goexperiment.regabidefer
-// +build goexperiment.regabidefer
-
-package goexperiment
-
-const RegabiDefer = true
-const RegabiDeferInt = 1
diff --git a/src/internal/goexperiment/exp_regabig_off.go b/src/internal/goexperiment/exp_regabig_off.go
deleted file mode 100644
index 1b37d451868..00000000000
--- a/src/internal/goexperiment/exp_regabig_off.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build !goexperiment.regabig
-// +build !goexperiment.regabig
-
-package goexperiment
-
-const RegabiG = false
-const RegabiGInt = 0
diff --git a/src/internal/goexperiment/exp_regabig_on.go b/src/internal/goexperiment/exp_regabig_on.go
deleted file mode 100644
index 7e5b162e0b2..00000000000
--- a/src/internal/goexperiment/exp_regabig_on.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Code generated by mkconsts.go. DO NOT EDIT.
-
-//go:build goexperiment.regabig
-// +build goexperiment.regabig
-
-package goexperiment
-
-const RegabiG = true
-const RegabiGInt = 1
diff --git a/src/internal/goexperiment/exp_unified_off.go b/src/internal/goexperiment/exp_unified_off.go
new file mode 100644
index 00000000000..4c16fd85624
--- /dev/null
+++ b/src/internal/goexperiment/exp_unified_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.unified
+// +build !goexperiment.unified
+
+package goexperiment
+
+const Unified = false
+const UnifiedInt = 0
diff --git a/src/internal/goexperiment/exp_unified_on.go b/src/internal/goexperiment/exp_unified_on.go
new file mode 100644
index 00000000000..2b17ba3e79b
--- /dev/null
+++ b/src/internal/goexperiment/exp_unified_on.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build goexperiment.unified
+// +build goexperiment.unified
+
+package goexperiment
+
+const Unified = true
+const UnifiedInt = 1
diff --git a/src/internal/goexperiment/flags.go b/src/internal/goexperiment/flags.go
index cd4c1788184..0a61a0e5fc1 100644
--- a/src/internal/goexperiment/flags.go
+++ b/src/internal/goexperiment/flags.go
@@ -59,6 +59,10 @@ type Flags struct {
 	PreemptibleLoops  bool
 	StaticLockRanking bool
 
+	// Unified enables the compiler's unified IR construction
+	// experiment.
+	Unified bool
+
 	// Regabi is split into several sub-experiments that can be
 	// enabled individually. Not all combinations work.
 	// The "regabi" GOEXPERIMENT is an alias for all "working"
@@ -68,26 +72,15 @@ type Flags struct {
 	// ABI0 and ABIInternal functions. Without this, the ABIs are
 	// assumed to be identical so cross-ABI calls are direct.
 	RegabiWrappers bool
-	// RegabiG enables dedicated G and zero registers in
-	// ABIInternal.
-	//
-	// Requires wrappers because it makes the ABIs incompatible.
-	RegabiG bool
 	// RegabiReflect enables the register-passing paths in
 	// reflection calls. This is also gated by intArgRegs in
 	// reflect and runtime (which are disabled by default) so it
 	// can be used in targeted tests.
 	RegabiReflect bool
-	// RegabiDefer enables desugaring defer and go calls
-	// into argument-less closures.
-	RegabiDefer bool
 	// RegabiArgs enables register arguments/results in all
 	// compiled Go functions.
 	//
-	// Requires wrappers (to do ABI translation), g (because
-	// runtime assembly that's been ported to ABIInternal uses the
-	// G register), reflect (so reflection calls use registers),
-	// and defer (because the runtime doesn't support passing
-	// register arguments to defer/go).
+	// Requires wrappers (to do ABI translation), and reflect (so
+	// reflection calls use registers).
 	RegabiArgs bool
 }
diff --git a/src/internal/goos/gengoos.go b/src/internal/goos/gengoos.go
new file mode 100644
index 00000000000..1860cd700df
--- /dev/null
+++ b/src/internal/goos/gengoos.go
@@ -0,0 +1,70 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var gooses []string
+
+func main() {
+	data, err := os.ReadFile("../../go/build/syslist.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	const goosPrefix = `const goosList = `
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.HasPrefix(line, goosPrefix) {
+			text, err := strconv.Unquote(strings.TrimPrefix(line, goosPrefix))
+			if err != nil {
+				log.Fatalf("parsing goosList: %v", err)
+			}
+			gooses = strings.Fields(text)
+		}
+	}
+
+	for _, target := range gooses {
+		if target == "nacl" {
+			continue
+		}
+		var tags []string
+		if target == "linux" {
+			tags = append(tags, "!android") // must explicitly exclude android for linux
+		}
+		if target == "solaris" {
+			tags = append(tags, "!illumos") // must explicitly exclude illumos for solaris
+		}
+		if target == "darwin" {
+			tags = append(tags, "!ios") // must explicitly exclude ios for darwin
+		}
+		tags = append(tags, target) // must explicitly include target for bootstrapping purposes
+		var buf bytes.Buffer
+		fmt.Fprintf(&buf, "// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.\n\n")
+		fmt.Fprintf(&buf, "//go:build %s\n", strings.Join(tags, " && "))
+		fmt.Fprintf(&buf, "// +build %s\n\n", strings.Join(tags, ","))
+		fmt.Fprintf(&buf, "package goos\n\n")
+		fmt.Fprintf(&buf, "const GOOS = `%s`\n\n", target)
+		for _, goos := range gooses {
+			value := 0
+			if goos == target {
+				value = 1
+			}
+			fmt.Fprintf(&buf, "const Is%s = %d\n", strings.Title(goos), value)
+		}
+		err := os.WriteFile("zgoos_"+target+".go", buf.Bytes(), 0666)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+}
diff --git a/src/internal/goos/goos.go b/src/internal/goos/goos.go
new file mode 100644
index 00000000000..ebb521fec68
--- /dev/null
+++ b/src/internal/goos/goos.go
@@ -0,0 +1,12 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// package goos contains GOOS-specific constants.
+package goos
+
+// The next line makes 'go generate' write the zgoos*.go files with
+// per-OS information, including constants named Is$GOOS for every
+// known GOOS. The constant is 1 on the current system, 0 otherwise;
+// multiplying by them is useful for defining GOOS-specific constants.
+//go:generate go run gengoos.go
diff --git a/src/internal/goos/zgoos_aix.go b/src/internal/goos/zgoos_aix.go
new file mode 100644
index 00000000000..063e698b82c
--- /dev/null
+++ b/src/internal/goos/zgoos_aix.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build aix
+// +build aix
+
+package goos
+
+const GOOS = `aix`
+
+const IsAix = 1
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_android.go b/src/internal/goos/zgoos_android.go
new file mode 100644
index 00000000000..e9e48649782
--- /dev/null
+++ b/src/internal/goos/zgoos_android.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build android
+// +build android
+
+package goos
+
+const GOOS = `android`
+
+const IsAix = 0
+const IsAndroid = 1
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_darwin.go b/src/internal/goos/zgoos_darwin.go
new file mode 100644
index 00000000000..309d6a27172
--- /dev/null
+++ b/src/internal/goos/zgoos_darwin.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build !ios && darwin
+// +build !ios,darwin
+
+package goos
+
+const GOOS = `darwin`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 1
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_dragonfly.go b/src/internal/goos/zgoos_dragonfly.go
new file mode 100644
index 00000000000..4e8711b94c5
--- /dev/null
+++ b/src/internal/goos/zgoos_dragonfly.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build dragonfly
+// +build dragonfly
+
+package goos
+
+const GOOS = `dragonfly`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 1
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_freebsd.go b/src/internal/goos/zgoos_freebsd.go
new file mode 100644
index 00000000000..f312bd16081
--- /dev/null
+++ b/src/internal/goos/zgoos_freebsd.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build freebsd
+// +build freebsd
+
+package goos
+
+const GOOS = `freebsd`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 1
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_hurd.go b/src/internal/goos/zgoos_hurd.go
new file mode 100644
index 00000000000..0f0dd28b81b
--- /dev/null
+++ b/src/internal/goos/zgoos_hurd.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build hurd
+// +build hurd
+
+package goos
+
+const GOOS = `hurd`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 1
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_illumos.go b/src/internal/goos/zgoos_illumos.go
new file mode 100644
index 00000000000..17e7c53a403
--- /dev/null
+++ b/src/internal/goos/zgoos_illumos.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build illumos
+// +build illumos
+
+package goos
+
+const GOOS = `illumos`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 1
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_ios.go b/src/internal/goos/zgoos_ios.go
new file mode 100644
index 00000000000..e4745ca4134
--- /dev/null
+++ b/src/internal/goos/zgoos_ios.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build ios
+// +build ios
+
+package goos
+
+const GOOS = `ios`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 1
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_js.go b/src/internal/goos/zgoos_js.go
new file mode 100644
index 00000000000..bd2417e9cea
--- /dev/null
+++ b/src/internal/goos/zgoos_js.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build js
+// +build js
+
+package goos
+
+const GOOS = `js`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 1
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_linux.go b/src/internal/goos/zgoos_linux.go
new file mode 100644
index 00000000000..476702f442a
--- /dev/null
+++ b/src/internal/goos/zgoos_linux.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build !android && linux
+// +build !android,linux
+
+package goos
+
+const GOOS = `linux`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 1
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_netbsd.go b/src/internal/goos/zgoos_netbsd.go
new file mode 100644
index 00000000000..97b7564babd
--- /dev/null
+++ b/src/internal/goos/zgoos_netbsd.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build netbsd
+// +build netbsd
+
+package goos
+
+const GOOS = `netbsd`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 1
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_openbsd.go b/src/internal/goos/zgoos_openbsd.go
new file mode 100644
index 00000000000..384a96480d6
--- /dev/null
+++ b/src/internal/goos/zgoos_openbsd.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build openbsd
+// +build openbsd
+
+package goos
+
+const GOOS = `openbsd`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 1
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_plan9.go b/src/internal/goos/zgoos_plan9.go
new file mode 100644
index 00000000000..fcc279a79ec
--- /dev/null
+++ b/src/internal/goos/zgoos_plan9.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build plan9
+// +build plan9
+
+package goos
+
+const GOOS = `plan9`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 1
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_solaris.go b/src/internal/goos/zgoos_solaris.go
new file mode 100644
index 00000000000..3f366cf7101
--- /dev/null
+++ b/src/internal/goos/zgoos_solaris.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build !illumos && solaris
+// +build !illumos,solaris
+
+package goos
+
+const GOOS = `solaris`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 1
+const IsWindows = 0
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_windows.go b/src/internal/goos/zgoos_windows.go
new file mode 100644
index 00000000000..dfa55339d34
--- /dev/null
+++ b/src/internal/goos/zgoos_windows.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build windows
+// +build windows
+
+package goos
+
+const GOOS = `windows`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 1
+const IsZos = 0
diff --git a/src/internal/goos/zgoos_zos.go b/src/internal/goos/zgoos_zos.go
new file mode 100644
index 00000000000..714f24963a2
--- /dev/null
+++ b/src/internal/goos/zgoos_zos.go
@@ -0,0 +1,26 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build zos
+// +build zos
+
+package goos
+
+const GOOS = `zos`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 1
diff --git a/src/internal/goversion/goversion.go b/src/internal/goversion/goversion.go
index 4cc15688c0b..8fcea100dc6 100644
--- a/src/internal/goversion/goversion.go
+++ b/src/internal/goversion/goversion.go
@@ -9,4 +9,4 @@ package goversion
 //
 // It should be updated at the start of each development cycle to be
 // the version of the next Go 1.x release. See golang.org/issue/40705.
-const Version = 17
+const Version = 18
diff --git a/src/internal/reflectlite/all_test.go b/src/internal/reflectlite/all_test.go
index e2c4f30487b..e15f364fcd3 100644
--- a/src/internal/reflectlite/all_test.go
+++ b/src/internal/reflectlite/all_test.go
@@ -982,19 +982,6 @@ func TestNames(t *testing.T) {
 	}
 }
 
-type embed struct {
-	EmbedWithUnexpMeth
-}
-
-func TestNameBytesAreAligned(t *testing.T) {
-	typ := TypeOf(embed{})
-	b := FirstMethodNameBytes(typ)
-	v := uintptr(unsafe.Pointer(b))
-	if v%unsafe.Alignof((*byte)(nil)) != 0 {
-		t.Errorf("reflect.name.bytes pointer is not aligned: %x", v)
-	}
-}
-
 // TestUnaddressableField tests that the reflect package will not allow
 // a type from another package to be used as a named type with an
 // unexported field.
diff --git a/src/internal/reflectlite/swapper.go b/src/internal/reflectlite/swapper.go
index 6330ab2d346..ac081d49bbb 100644
--- a/src/internal/reflectlite/swapper.go
+++ b/src/internal/reflectlite/swapper.go
@@ -5,6 +5,7 @@
 package reflectlite
 
 import (
+	"internal/goarch"
 	"internal/unsafeheader"
 	"unsafe"
 )
@@ -36,7 +37,7 @@ func Swapper(slice interface{}) func(i, j int) {
 
 	// Some common & small cases, without using memmove:
 	if hasPtr {
-		if size == ptrSize {
+		if size == goarch.PtrSize {
 			ps := *(*[]unsafe.Pointer)(v.ptr)
 			return func(i, j int) { ps[i], ps[j] = ps[j], ps[i] }
 		}
diff --git a/src/internal/reflectlite/type.go b/src/internal/reflectlite/type.go
index 15ba30da36c..b1899b0191f 100644
--- a/src/internal/reflectlite/type.go
+++ b/src/internal/reflectlite/type.go
@@ -68,7 +68,7 @@ type Type interface {
 }
 
 /*
- * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go).
+ * These data structures are known to the compiler (../../cmd/internal/reflectdata/reflect.go).
  * A few are known to ../runtime/type.go to convey to debuggers.
  * They are also known to ../runtime/type.go.
  */
@@ -111,7 +111,7 @@ const (
 // available in the memory directly following the rtype value.
 //
 // tflag values must be kept in sync with copies in:
-//	cmd/compile/internal/gc/reflect.go
+//	cmd/compile/internal/reflectdata/reflect.go
 //	cmd/link/internal/ld/decodesym.go
 //	runtime/type.go
 type tflag uint8
@@ -321,49 +321,55 @@ func (n name) isExported() bool {
 	return (*n.bytes)&(1<<0) != 0
 }
 
-func (n name) nameLen() int {
-	return int(uint16(*n.data(1, "name len field"))<<8 | uint16(*n.data(2, "name len field")))
+func (n name) hasTag() bool {
+	return (*n.bytes)&(1<<1) != 0
 }
 
-func (n name) tagLen() int {
-	if *n.data(0, "name flag field")&(1<<1) == 0 {
-		return 0
+// readVarint parses a varint as encoded by encoding/binary.
+// It returns the number of encoded bytes and the encoded value.
+func (n name) readVarint(off int) (int, int) {
+	v := 0
+	for i := 0; ; i++ {
+		x := *n.data(off+i, "read varint")
+		v += int(x&0x7f) << (7 * i)
+		if x&0x80 == 0 {
+			return i + 1, v
+		}
 	}
-	off := 3 + n.nameLen()
-	return int(uint16(*n.data(off, "name taglen field"))<<8 | uint16(*n.data(off+1, "name taglen field")))
 }
 
 func (n name) name() (s string) {
 	if n.bytes == nil {
 		return
 	}
-	b := (*[4]byte)(unsafe.Pointer(n.bytes))
-
+	i, l := n.readVarint(1)
 	hdr := (*unsafeheader.String)(unsafe.Pointer(&s))
-	hdr.Data = unsafe.Pointer(&b[3])
-	hdr.Len = int(b[1])<<8 | int(b[2])
-	return s
+	hdr.Data = unsafe.Pointer(n.data(1+i, "non-empty string"))
+	hdr.Len = l
+	return
 }
 
 func (n name) tag() (s string) {
-	tl := n.tagLen()
-	if tl == 0 {
+	if !n.hasTag() {
 		return ""
 	}
-	nl := n.nameLen()
+	i, l := n.readVarint(1)
+	i2, l2 := n.readVarint(1 + i + l)
 	hdr := (*unsafeheader.String)(unsafe.Pointer(&s))
-	hdr.Data = unsafe.Pointer(n.data(3+nl+2, "non-empty string"))
-	hdr.Len = tl
-	return s
+	hdr.Data = unsafe.Pointer(n.data(1+i+l+i2, "non-empty string"))
+	hdr.Len = l2
+	return
 }
 
 func (n name) pkgPath() string {
 	if n.bytes == nil || *n.data(0, "name flag field")&(1<<2) == 0 {
 		return ""
 	}
-	off := 3 + n.nameLen()
-	if tl := n.tagLen(); tl > 0 {
-		off += 2 + tl
+	i, l := n.readVarint(1)
+	off := 1 + i + l
+	if n.hasTag() {
+		i2, l2 := n.readVarint(off)
+		off += i2 + l2
 	}
 	var nameOff int32
 	// Note that this field may not be aligned in memory,
diff --git a/src/internal/reflectlite/value.go b/src/internal/reflectlite/value.go
index 0365eeeabf6..136273842ce 100644
--- a/src/internal/reflectlite/value.go
+++ b/src/internal/reflectlite/value.go
@@ -5,13 +5,12 @@
 package reflectlite
 
 import (
+	"internal/goarch"
 	"internal/unsafeheader"
 	"runtime"
 	"unsafe"
 )
 
-const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const
-
 // Value is the reflection interface to a Go value.
 //
 // Not all methods apply to all kinds of values. Restrictions,
@@ -90,7 +89,7 @@ func (f flag) ro() flag {
 // pointer returns the underlying pointer represented by v.
 // v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer
 func (v Value) pointer() unsafe.Pointer {
-	if v.typ.size != ptrSize || !v.typ.pointers() {
+	if v.typ.size != goarch.PtrSize || !v.typ.pointers() {
 		panic("can't call pointer on a non-pointer Value")
 	}
 	if v.flag&flagIndir != 0 {
diff --git a/src/internal/syscall/windows/exec_windows_test.go b/src/internal/syscall/windows/exec_windows_test.go
index 283d7cea94b..0db626636e9 100644
--- a/src/internal/syscall/windows/exec_windows_test.go
+++ b/src/internal/syscall/windows/exec_windows_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package windows_test
diff --git a/src/internal/syscall/windows/mksyscall.go b/src/internal/syscall/windows/mksyscall.go
index 599f07601bd..39f745db7a3 100644
--- a/src/internal/syscall/windows/mksyscall.go
+++ b/src/internal/syscall/windows/mksyscall.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build generate
 // +build generate
 
 package windows
diff --git a/src/internal/syscall/windows/registry/export_test.go b/src/internal/syscall/windows/registry/export_test.go
index 8badf6fdcf1..d02d93f2875 100644
--- a/src/internal/syscall/windows/registry/export_test.go
+++ b/src/internal/syscall/windows/registry/export_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package registry
diff --git a/src/internal/syscall/windows/registry/key.go b/src/internal/syscall/windows/registry/key.go
index 612c48f0840..ebe73a2e024 100644
--- a/src/internal/syscall/windows/registry/key.go
+++ b/src/internal/syscall/windows/registry/key.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 // Package registry provides access to the Windows registry.
diff --git a/src/internal/syscall/windows/registry/mksyscall.go b/src/internal/syscall/windows/registry/mksyscall.go
index 320abf7fc69..0a007df7ccd 100644
--- a/src/internal/syscall/windows/registry/mksyscall.go
+++ b/src/internal/syscall/windows/registry/mksyscall.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build generate
 // +build generate
 
 package registry
diff --git a/src/internal/syscall/windows/registry/registry_test.go b/src/internal/syscall/windows/registry/registry_test.go
index 57971629006..69b84e1c4c5 100644
--- a/src/internal/syscall/windows/registry/registry_test.go
+++ b/src/internal/syscall/windows/registry/registry_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package registry_test
diff --git a/src/internal/syscall/windows/registry/syscall.go b/src/internal/syscall/windows/registry/syscall.go
index a6525dac5d9..bb612793613 100644
--- a/src/internal/syscall/windows/registry/syscall.go
+++ b/src/internal/syscall/windows/registry/syscall.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package registry
diff --git a/src/internal/syscall/windows/registry/value.go b/src/internal/syscall/windows/registry/value.go
index dc3930a6bc2..e1fc99c40d4 100644
--- a/src/internal/syscall/windows/registry/value.go
+++ b/src/internal/syscall/windows/registry/value.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package registry
diff --git a/src/internal/syscall/windows/sysdll/sysdll.go b/src/internal/syscall/windows/sysdll/sysdll.go
index c587c19c77d..61b998e4cfc 100644
--- a/src/internal/syscall/windows/sysdll/sysdll.go
+++ b/src/internal/syscall/windows/sysdll/sysdll.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 // Package sysdll is an internal leaf package that records and reports
diff --git a/src/io/fs/example_test.go b/src/io/fs/example_test.go
new file mode 100644
index 00000000000..c9027034c4a
--- /dev/null
+++ b/src/io/fs/example_test.go
@@ -0,0 +1,25 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs_test
+
+import (
+	"fmt"
+	"io/fs"
+	"log"
+	"os"
+)
+
+func ExampleWalkDir() {
+	root := "/usr/local/go/bin"
+	fileSystem := os.DirFS(root)
+
+	fs.WalkDir(fileSystem, ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Println(path)
+		return nil
+	})
+}
diff --git a/src/io/fs/fs.go b/src/io/fs/fs.go
index e1be32478e0..e603afadb0b 100644
--- a/src/io/fs/fs.go
+++ b/src/io/fs/fs.go
@@ -86,7 +86,7 @@ type File interface {
 type DirEntry interface {
 	// Name returns the name of the file (or subdirectory) described by the entry.
 	// This name is only the final element of the path (the base name), not the entire path.
-	// For example, Name would return "hello.go" not "/home/gopher/hello.go".
+	// For example, Name would return "hello.go" not "home/gopher/hello.go".
 	Name() string
 
 	// IsDir reports whether the entry describes a directory.
diff --git a/src/io/fs/sub.go b/src/io/fs/sub.go
index 7822e555eaa..ae20e030a93 100644
--- a/src/io/fs/sub.go
+++ b/src/io/fs/sub.go
@@ -19,10 +19,10 @@ type SubFS interface {
 
 // Sub returns an FS corresponding to the subtree rooted at fsys's dir.
 //
-// If fs implements SubFS, Sub calls returns fsys.Sub(dir).
-// Otherwise, if dir is ".", Sub returns fsys unchanged.
+// If dir is ".", Sub returns fsys unchanged.
+// Otherwise, if fs implements SubFS, Sub returns fsys.Sub(dir).
 // Otherwise, Sub returns a new FS implementation sub that,
-// in effect, implements sub.Open(dir) as fsys.Open(path.Join(dir, name)).
+// in effect, implements sub.Open(name) as fsys.Open(path.Join(dir, name)).
 // The implementation also translates calls to ReadDir, ReadFile, and Glob appropriately.
 //
 // Note that Sub(os.DirFS("/"), "prefix") is equivalent to os.DirFS("/prefix")
diff --git a/src/make.bash b/src/make.bash
index 3d1b0c87e75..7986125a06f 100755
--- a/src/make.bash
+++ b/src/make.bash
@@ -130,12 +130,13 @@ if [ "$(uname -s)" = "GNU/kFreeBSD" ]; then
 	export CGO_ENABLED=0
 fi
 
-# Test which linker/loader our system is using
-if type readelf >/dev/null 2>&1; then
-	echo "int main() { return 0; }" | ${CC:-cc} -o ./test-musl-ldso -x c - || continue
-	LDSO=$(readelf -l ./test-musl-ldso | grep 'interpreter:' | sed -e 's/^.*interpreter: \(.*\)[]]/\1/') >/dev/null 2>&1
-	[ -z "$LDSO" ] || export GO_LDSO="$LDSO"
-	rm -f ./test-musl-ldso
+# Test which linker/loader our system is using, if GO_LDSO is not set.
+if [ -z "$GO_LDSO" ] && type readelf >/dev/null 2>&1; then
+	if echo "int main() { return 0; }" | ${CC:-cc} -o ./test-musl-ldso -x c - >/dev/null 2>&1; then
+		LDSO=$(readelf -l ./test-musl-ldso | grep 'interpreter:' | sed -e 's/^.*interpreter: \(.*\)[]]/\1/') >/dev/null 2>&1
+		[ -z "$LDSO" ] || export GO_LDSO="$LDSO"
+		rm -f ./test-musl-ldso
+	fi
 fi
 
 # Clean old generated file that will cause problems in the build.
@@ -202,16 +203,10 @@ if [ "$1" = "--dist-tool" ]; then
 	exit 0
 fi
 
-buildall="-a"
-if [ "$1" = "--no-clean" ]; then
-	buildall=""
-	shift
-fi
-
 # Run dist bootstrap to complete make.bash.
 # Bootstrap installs a proper cmd/dist, built with the new toolchain.
 # Throw ours, built with Go 1.4, away after bootstrap.
-./cmd/dist/dist bootstrap $buildall $vflag $GO_DISTFLAGS "$@"
+./cmd/dist/dist bootstrap -a $vflag $GO_DISTFLAGS "$@"
 rm -f ./cmd/dist/dist
 
 # DO NOT ADD ANY NEW CODE HERE.
diff --git a/src/make.bat b/src/make.bat
index b4a8e708490..8f2825b09a9 100644
--- a/src/make.bat
+++ b/src/make.bat
@@ -112,20 +112,20 @@ if x%2==x--dist-tool goto copydist
 if x%3==x--dist-tool goto copydist
 if x%4==x--dist-tool goto copydist
 
-set buildall=-a
-if x%1==x--no-clean set buildall=
-if x%2==x--no-clean set buildall=
-if x%3==x--no-clean set buildall=
-if x%4==x--no-clean set buildall=
-if x%1==x--no-banner set buildall=%buildall% --no-banner
-if x%2==x--no-banner set buildall=%buildall% --no-banner
-if x%3==x--no-banner set buildall=%buildall% --no-banner
-if x%4==x--no-banner set buildall=%buildall% --no-banner
+set bootstrapflags=
+if x%1==x--no-clean set bootstrapflags=--no-clean
+if x%2==x--no-clean set bootstrapflags=--no-clean
+if x%3==x--no-clean set bootstrapflags=--no-clean
+if x%4==x--no-clean set bootstrapflags=--no-clean
+if x%1==x--no-banner set bootstrapflags=%bootstrapflags% --no-banner
+if x%2==x--no-banner set bootstrapflags=%bootstrapflags% --no-banner
+if x%3==x--no-banner set bootstrapflags=%bootstrapflags% --no-banner
+if x%4==x--no-banner set bootstrapflags=%bootstrapflags% --no-banner
 
 :: Run dist bootstrap to complete make.bash.
 :: Bootstrap installs a proper cmd/dist, built with the new toolchain.
 :: Throw ours, built with Go 1.4, away after bootstrap.
-.\cmd\dist\dist.exe bootstrap %vflag% %buildall%
+.\cmd\dist\dist.exe bootstrap -a %vflag% %bootstrapflags%
 if errorlevel 1 goto fail
 del .\cmd\dist\dist.exe
 goto end
diff --git a/src/make.rc b/src/make.rc
index f5e57e97556..7bdc7dea1c1 100755
--- a/src/make.rc
+++ b/src/make.rc
@@ -92,15 +92,10 @@ if(~ $1 --dist-tool){
 	exit
 }
 
-buildall = -a
-if(~ $1 --no-clean) {
-	buildall = ()
-	shift
-}
 # Run dist bootstrap to complete make.bash.
 # Bootstrap installs a proper cmd/dist, built with the new toolchain.
 # Throw ours, built with Go 1.4, away after bootstrap.
-./cmd/dist/dist bootstrap $vflag $buildall $*
+./cmd/dist/dist bootstrap -a $vflag $*
 rm -f ./cmd/dist/dist
 
 # DO NOT ADD ANY NEW CODE HERE.
diff --git a/src/math/big/arith.go b/src/math/big/arith.go
index e1947936d49..8f55c195d4b 100644
--- a/src/math/big/arith.go
+++ b/src/math/big/arith.go
@@ -267,20 +267,6 @@ func divWW(x1, x0, y, m Word) (q, r Word) {
 	return Word(qq), Word(r0 >> s)
 }
 
-func divWVW(z []Word, xn Word, x []Word, y Word) (r Word) {
-	r = xn
-	if len(x) == 1 {
-		qq, rr := bits.Div(uint(r), uint(x[0]), uint(y))
-		z[0] = Word(qq)
-		return Word(rr)
-	}
-	rec := reciprocalWord(y)
-	for i := len(z) - 1; i >= 0; i-- {
-		z[i], r = divWW(r, x[i], y, rec)
-	}
-	return r
-}
-
 // reciprocalWord return the reciprocal of the divisor. rec = floor(( _B^2 - 1 ) / u - _B). u = d1 << nlz(d1).
 func reciprocalWord(d1 Word) Word {
 	u := uint(d1 << nlz(d1))
diff --git a/src/math/big/arith_386.s b/src/math/big/arith_386.s
index d0ea949fe66..acf2b06665a 100644
--- a/src/math/big/arith_386.s
+++ b/src/math/big/arith_386.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go
 // +build !math_big_pure_go
 
 #include "textflag.h"
diff --git a/src/math/big/arith_amd64.s b/src/math/big/arith_amd64.s
index 61043ca2d97..59be952200f 100644
--- a/src/math/big/arith_amd64.s
+++ b/src/math/big/arith_amd64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go
 // +build !math_big_pure_go
 
 #include "textflag.h"
diff --git a/src/math/big/arith_arm.s b/src/math/big/arith_arm.s
index cbf7445e7ab..f2872d80a1a 100644
--- a/src/math/big/arith_arm.s
+++ b/src/math/big/arith_arm.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go
 // +build !math_big_pure_go
 
 #include "textflag.h"
diff --git a/src/math/big/arith_arm64.s b/src/math/big/arith_arm64.s
index 22357d088e4..7bfe08e7b7c 100644
--- a/src/math/big/arith_arm64.s
+++ b/src/math/big/arith_arm64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go
 // +build !math_big_pure_go
 
 #include "textflag.h"
diff --git a/src/math/big/arith_mips64x.s b/src/math/big/arith_mips64x.s
index 804b9fe06ed..4b5c502440f 100644
--- a/src/math/big/arith_mips64x.s
+++ b/src/math/big/arith_mips64x.s
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !math_big_pure_go,mips64 !math_big_pure_go,mips64le
+//go:build !math_big_pure_go && (mips64 || mips64le)
+// +build !math_big_pure_go
+// +build mips64 mips64le
 
 #include "textflag.h"
 
diff --git a/src/math/big/arith_mipsx.s b/src/math/big/arith_mipsx.s
index efdecb80f32..e72e6d6377e 100644
--- a/src/math/big/arith_mipsx.s
+++ b/src/math/big/arith_mipsx.s
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !math_big_pure_go,mips !math_big_pure_go,mipsle
+//go:build !math_big_pure_go && (mips || mipsle)
+// +build !math_big_pure_go
+// +build mips mipsle
 
 #include "textflag.h"
 
diff --git a/src/math/big/arith_ppc64x.s b/src/math/big/arith_ppc64x.s
index b299ccc2fb8..68c62864946 100644
--- a/src/math/big/arith_ppc64x.s
+++ b/src/math/big/arith_ppc64x.s
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !math_big_pure_go,ppc64 !math_big_pure_go,ppc64le
+//go:build !math_big_pure_go && (ppc64 || ppc64le)
+// +build !math_big_pure_go
+// +build ppc64 ppc64le
 
 #include "textflag.h"
 
diff --git a/src/math/big/arith_riscv64.s b/src/math/big/arith_riscv64.s
index a2f7666c7b9..2e950ddd0f3 100644
--- a/src/math/big/arith_riscv64.s
+++ b/src/math/big/arith_riscv64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go && riscv64
 // +build !math_big_pure_go,riscv64
 
 #include "textflag.h"
diff --git a/src/math/big/arith_s390x.s b/src/math/big/arith_s390x.s
index e96480699af..ad822f76b39 100644
--- a/src/math/big/arith_s390x.s
+++ b/src/math/big/arith_s390x.s
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !math_big_pure_go,s390x
+//go:build !math_big_pure_go
+// +build !math_big_pure_go
 
 #include "textflag.h"
 
diff --git a/src/math/big/arith_wasm.s b/src/math/big/arith_wasm.s
index add10644690..e8605f1e153 100644
--- a/src/math/big/arith_wasm.s
+++ b/src/math/big/arith_wasm.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !math_big_pure_go
 // +build !math_big_pure_go
 
 #include "textflag.h"
diff --git a/src/math/big/int.go b/src/math/big/int.go
index 65f32487b58..7647346486c 100644
--- a/src/math/big/int.go
+++ b/src/math/big/int.go
@@ -425,7 +425,7 @@ func (z *Int) SetString(s string, base int) (*Int, bool) {
 	return z.setFromScanner(strings.NewReader(s), base)
 }
 
-// setFromScanner implements SetString given an io.BytesScanner.
+// setFromScanner implements SetString given an io.ByteScanner.
 // For documentation see comments of SetString.
 func (z *Int) setFromScanner(r io.ByteScanner, base int) (*Int, bool) {
 	if _, _, err := z.scan(r, base); err != nil {
diff --git a/src/math/big/nat.go b/src/math/big/nat.go
index bbd6c8850b6..140c619c8ca 100644
--- a/src/math/big/nat.go
+++ b/src/math/big/nat.go
@@ -631,48 +631,6 @@ func (z nat) mulRange(a, b uint64) nat {
 	return z.mul(nat(nil).mulRange(a, m), nat(nil).mulRange(m+1, b))
 }
 
-// q = (x-r)/y, with 0 <= r < y
-func (z nat) divW(x nat, y Word) (q nat, r Word) {
-	m := len(x)
-	switch {
-	case y == 0:
-		panic("division by zero")
-	case y == 1:
-		q = z.set(x) // result is x
-		return
-	case m == 0:
-		q = z[:0] // result is 0
-		return
-	}
-	// m > 0
-	z = z.make(m)
-	r = divWVW(z, 0, x, y)
-	q = z.norm()
-	return
-}
-
-func (z nat) div(z2, u, v nat) (q, r nat) {
-	if len(v) == 0 {
-		panic("division by zero")
-	}
-
-	if u.cmp(v) < 0 {
-		q = z[:0]
-		r = z2.set(u)
-		return
-	}
-
-	if len(v) == 1 {
-		var r2 Word
-		q, r2 = z.divW(u, v[0])
-		r = z2.setWord(r2)
-		return
-	}
-
-	q, r = z.divLarge(z2, u, v)
-	return
-}
-
 // getNat returns a *nat of len n. The contents may not be zero.
 // The pool holds *nat to avoid allocation when converting to interface{}.
 func getNat(n int) *nat {
@@ -693,276 +651,6 @@ func putNat(x *nat) {
 
 var natPool sync.Pool
 
-// q = (uIn-r)/vIn, with 0 <= r < vIn
-// Uses z as storage for q, and u as storage for r if possible.
-// See Knuth, Volume 2, section 4.3.1, Algorithm D.
-// Preconditions:
-//    len(vIn) >= 2
-//    len(uIn) >= len(vIn)
-//    u must not alias z
-func (z nat) divLarge(u, uIn, vIn nat) (q, r nat) {
-	n := len(vIn)
-	m := len(uIn) - n
-
-	// D1.
-	shift := nlz(vIn[n-1])
-	// do not modify vIn, it may be used by another goroutine simultaneously
-	vp := getNat(n)
-	v := *vp
-	shlVU(v, vIn, shift)
-
-	// u may safely alias uIn or vIn, the value of uIn is used to set u and vIn was already used
-	u = u.make(len(uIn) + 1)
-	u[len(uIn)] = shlVU(u[0:len(uIn)], uIn, shift)
-
-	// z may safely alias uIn or vIn, both values were used already
-	if alias(z, u) {
-		z = nil // z is an alias for u - cannot reuse
-	}
-	q = z.make(m + 1)
-
-	if n < divRecursiveThreshold {
-		q.divBasic(u, v)
-	} else {
-		q.divRecursive(u, v)
-	}
-	putNat(vp)
-
-	q = q.norm()
-	shrVU(u, u, shift)
-	r = u.norm()
-
-	return q, r
-}
-
-// divBasic performs word-by-word division of u by v.
-// The quotient is written in pre-allocated q.
-// The remainder overwrites input u.
-//
-// Precondition:
-// - q is large enough to hold the quotient u / v
-//   which has a maximum length of len(u)-len(v)+1.
-func (q nat) divBasic(u, v nat) {
-	n := len(v)
-	m := len(u) - n
-
-	qhatvp := getNat(n + 1)
-	qhatv := *qhatvp
-
-	// D2.
-	vn1 := v[n-1]
-	rec := reciprocalWord(vn1)
-	for j := m; j >= 0; j-- {
-		// D3.
-		qhat := Word(_M)
-		var ujn Word
-		if j+n < len(u) {
-			ujn = u[j+n]
-		}
-		if ujn != vn1 {
-			var rhat Word
-			qhat, rhat = divWW(ujn, u[j+n-1], vn1, rec)
-
-			// x1 | x2 = q̂v_{n-2}
-			vn2 := v[n-2]
-			x1, x2 := mulWW(qhat, vn2)
-			// test if q̂v_{n-2} > br̂ + u_{j+n-2}
-			ujn2 := u[j+n-2]
-			for greaterThan(x1, x2, rhat, ujn2) {
-				qhat--
-				prevRhat := rhat
-				rhat += vn1
-				// v[n-1] >= 0, so this tests for overflow.
-				if rhat < prevRhat {
-					break
-				}
-				x1, x2 = mulWW(qhat, vn2)
-			}
-		}
-
-		// D4.
-		// Compute the remainder u - (q̂*v) << (_W*j).
-		// The subtraction may overflow if q̂ estimate was off by one.
-		qhatv[n] = mulAddVWW(qhatv[0:n], v, qhat, 0)
-		qhl := len(qhatv)
-		if j+qhl > len(u) && qhatv[n] == 0 {
-			qhl--
-		}
-		c := subVV(u[j:j+qhl], u[j:], qhatv)
-		if c != 0 {
-			c := addVV(u[j:j+n], u[j:], v)
-			// If n == qhl, the carry from subVV and the carry from addVV
-			// cancel out and don't affect u[j+n].
-			if n < qhl {
-				u[j+n] += c
-			}
-			qhat--
-		}
-
-		if j == m && m == len(q) && qhat == 0 {
-			continue
-		}
-		q[j] = qhat
-	}
-
-	putNat(qhatvp)
-}
-
-const divRecursiveThreshold = 100
-
-// divRecursive performs word-by-word division of u by v.
-// The quotient is written in pre-allocated z.
-// The remainder overwrites input u.
-//
-// Precondition:
-// - len(z) >= len(u)-len(v)
-//
-// See Burnikel, Ziegler, "Fast Recursive Division", Algorithm 1 and 2.
-func (z nat) divRecursive(u, v nat) {
-	// Recursion depth is less than 2 log2(len(v))
-	// Allocate a slice of temporaries to be reused across recursion.
-	recDepth := 2 * bits.Len(uint(len(v)))
-	// large enough to perform Karatsuba on operands as large as v
-	tmp := getNat(3 * len(v))
-	temps := make([]*nat, recDepth)
-	z.clear()
-	z.divRecursiveStep(u, v, 0, tmp, temps)
-	for _, n := range temps {
-		if n != nil {
-			putNat(n)
-		}
-	}
-	putNat(tmp)
-}
-
-// divRecursiveStep computes the division of u by v.
-// - z must be large enough to hold the quotient
-// - the quotient will overwrite z
-// - the remainder will overwrite u
-func (z nat) divRecursiveStep(u, v nat, depth int, tmp *nat, temps []*nat) {
-	u = u.norm()
-	v = v.norm()
-
-	if len(u) == 0 {
-		z.clear()
-		return
-	}
-	n := len(v)
-	if n < divRecursiveThreshold {
-		z.divBasic(u, v)
-		return
-	}
-	m := len(u) - n
-	if m < 0 {
-		return
-	}
-
-	// Produce the quotient by blocks of B words.
-	// Division by v (length n) is done using a length n/2 division
-	// and a length n/2 multiplication for each block. The final
-	// complexity is driven by multiplication complexity.
-	B := n / 2
-
-	// Allocate a nat for qhat below.
-	if temps[depth] == nil {
-		temps[depth] = getNat(n)
-	} else {
-		*temps[depth] = temps[depth].make(B + 1)
-	}
-
-	j := m
-	for j > B {
-		// Divide u[j-B:j+n] by vIn. Keep remainder in u
-		// for next block.
-		//
-		// The following property will be used (Lemma 2):
-		// if u = u1 << s + u0
-		//    v = v1 << s + v0
-		// then floor(u1/v1) >= floor(u/v)
-		//
-		// Moreover, the difference is at most 2 if len(v1) >= len(u/v)
-		// We choose s = B-1 since len(v)-s >= B+1 >= len(u/v)
-		s := (B - 1)
-		// Except for the first step, the top bits are always
-		// a division remainder, so the quotient length is <= n.
-		uu := u[j-B:]
-
-		qhat := *temps[depth]
-		qhat.clear()
-		qhat.divRecursiveStep(uu[s:B+n], v[s:], depth+1, tmp, temps)
-		qhat = qhat.norm()
-		// Adjust the quotient:
-		//    u = u_h << s + u_l
-		//    v = v_h << s + v_l
-		//  u_h = q̂ v_h + rh
-		//    u = q̂ (v - v_l) + rh << s + u_l
-		// After the above step, u contains a remainder:
-		//    u = rh << s + u_l
-		// and we need to subtract q̂ v_l
-		//
-		// But it may be a bit too large, in which case q̂ needs to be smaller.
-		qhatv := tmp.make(3 * n)
-		qhatv.clear()
-		qhatv = qhatv.mul(qhat, v[:s])
-		for i := 0; i < 2; i++ {
-			e := qhatv.cmp(uu.norm())
-			if e <= 0 {
-				break
-			}
-			subVW(qhat, qhat, 1)
-			c := subVV(qhatv[:s], qhatv[:s], v[:s])
-			if len(qhatv) > s {
-				subVW(qhatv[s:], qhatv[s:], c)
-			}
-			addAt(uu[s:], v[s:], 0)
-		}
-		if qhatv.cmp(uu.norm()) > 0 {
-			panic("impossible")
-		}
-		c := subVV(uu[:len(qhatv)], uu[:len(qhatv)], qhatv)
-		if c > 0 {
-			subVW(uu[len(qhatv):], uu[len(qhatv):], c)
-		}
-		addAt(z, qhat, j-B)
-		j -= B
-	}
-
-	// Now u < (v< 0 {
-			subVW(qhat, qhat, 1)
-			c := subVV(qhatv[:s], qhatv[:s], v[:s])
-			if len(qhatv) > s {
-				subVW(qhatv[s:], qhatv[s:], c)
-			}
-			addAt(u[s:], v[s:], 0)
-		}
-	}
-	if qhatv.cmp(u.norm()) > 0 {
-		panic("impossible")
-	}
-	c := subVV(u[0:len(qhatv)], u[0:len(qhatv)], qhatv)
-	if c > 0 {
-		c = subVW(u[len(qhatv):], u[len(qhatv):], c)
-	}
-	if c > 0 {
-		panic("impossible")
-	}
-
-	// Done!
-	addAt(z, qhat.norm(), 0)
-}
-
 // Length of x in bits. x must be normalized.
 func (x nat) bitLen() int {
 	if i := len(x) - 1; i >= 0 {
@@ -1170,19 +858,6 @@ func (z nat) xor(x, y nat) nat {
 	return z.norm()
 }
 
-// greaterThan reports whether (x1<<_W + x2) > (y1<<_W + y2)
-func greaterThan(x1, x2, y1, y2 Word) bool {
-	return x1 > y1 || x1 == y1 && x2 > y2
-}
-
-// modW returns x % d.
-func (x nat) modW(d Word) (r Word) {
-	// TODO(agl): we don't actually need to store the q value.
-	var q nat
-	q = q.make(len(x))
-	return divWVW(q, 0, x, d)
-}
-
 // random creates a random integer in [0..limit), using the space in z if
 // possible. n is the bit length of limit.
 func (z nat) random(rand *rand.Rand, limit nat, n int) nat {
diff --git a/src/math/big/natdiv.go b/src/math/big/natdiv.go
new file mode 100644
index 00000000000..882bb6d3bac
--- /dev/null
+++ b/src/math/big/natdiv.go
@@ -0,0 +1,884 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+
+Multi-precision division. Here be dragons.
+
+Given u and v, where u is n+m digits, and v is n digits (with no leading zeros),
+the goal is to return quo, rem such that u = quo*v + rem, where 0 ≤ rem < v.
+That is, quo = ⌊u/v⌋ where ⌊x⌋ denotes the floor (truncation to integer) of x,
+and rem = u - quo·v.
+
+
+Long Division
+
+Division in a computer proceeds the same as long division in elementary school,
+but computers are not as good as schoolchildren at following vague directions,
+so we have to be much more precise about the actual steps and what can happen.
+
+We work from most to least significant digit of the quotient, doing:
+
+ • Guess a digit q, the number of v to subtract from the current
+   section of u to zero out the topmost digit.
+ • Check the guess by multiplying q·v and comparing it against
+   the current section of u, adjusting the guess as needed.
+ • Subtract q·v from the current section of u.
+ • Add q to the corresponding section of the result quo.
+
+When all digits have been processed, the final remainder is left in u
+and returned as rem.
+
+For example, here is a sketch of dividing 5 digits by 3 digits (n=3, m=2).
+
+	                 q₂ q₁ q₀
+	         _________________
+	v₂ v₁ v₀ ) u₄ u₃ u₂ u₁ u₀
+	           ↓  ↓  ↓  |  |
+	          [u₄ u₃ u₂]|  |
+	        - [  q₂·v  ]|  |
+	        ----------- ↓  |
+	          [  rem  | u₁]|
+	        - [    q₁·v   ]|
+	           ----------- ↓
+	             [  rem  | u₀]
+	           - [    q₀·v   ]
+	              ------------
+	                [  rem   ]
+
+Instead of creating new storage for the remainders and copying digits from u
+as indicated by the arrows, we use u's storage directly as both the source
+and destination of the subtractions, so that the remainders overwrite
+successive overlapping sections of u as the division proceeds, using a slice
+of u to identify the current section. This avoids all the copying as well as
+shifting of remainders.
+
+Division of u with n+m digits by v with n digits (in base B) can in general
+produce at most m+1 digits, because:
+
+  • u < B^(n+m)               [B^(n+m) has n+m+1 digits]
+  • v ≥ B^(n-1)               [B^(n-1) is the smallest n-digit number]
+  • u/v < B^(n+m) / B^(n-1)   [divide bounds for u, v]
+  • u/v < B^(m+1)             [simplify]
+
+The first step is special: it takes the top n digits of u and divides them by
+the n digits of v, producing the first quotient digit and an n-digit remainder.
+In the example, q₂ = ⌊u₄u₃u₂ / v⌋.
+
+The first step divides n digits by n digits to ensure that it produces only a
+single digit.
+
+Each subsequent step appends the next digit from u to the remainder and divides
+those n+1 digits by the n digits of v, producing another quotient digit and a
+new n-digit remainder.
+
+Subsequent steps divide n+1 digits by n digits, an operation that in general
+might produce two digits. However, as used in the algorithm, that division is
+guaranteed to produce only a single digit. The dividend is of the form
+rem·B + d, where rem is a remainder from the previous step and d is a single
+digit, so:
+
+ • rem ≤ v - 1                 [rem is a remainder from dividing by v]
+ • rem·B ≤ v·B - B             [multiply by B]
+ • d ≤ B - 1                   [d is a single digit]
+ • rem·B + d ≤ v·B - 1         [add]
+ • rem·B + d < v·B             [change ≤ to <]
+ • (rem·B + d)/v < B           [divide by v]
+
+
+Guess and Check
+
+At each step we need to divide n+1 digits by n digits, but this is for the
+implementation of division by n digits, so we can't just invoke a division
+routine: we _are_ the division routine. Instead, we guess at the answer and
+then check it using multiplication. If the guess is wrong, we correct it.
+
+How can this guessing possibly be efficient? It turns out that the following
+statement (let's call it the Good Guess Guarantee) is true.
+
+If
+
+ • q = ⌊u/v⌋ where u is n+1 digits and v is n digits,
+ • q < B, and
+ • the topmost digit of v = vₙ₋₁ ≥ B/2,
+
+then q̂ = ⌊uₙuₙ₋₁ / vₙ₋₁⌋ satisfies q ≤ q̂ ≤ q+2. (Proof below.)
+
+That is, if we know the answer has only a single digit and we guess an answer
+by ignoring the bottom n-1 digits of u and v, using a 2-by-1-digit division,
+then that guess is at least as large as the correct answer. It is also not
+too much larger: it is off by at most two from the correct answer.
+
+Note that in the first step of the overall division, which is an n-by-n-digit
+division, the 2-by-1 guess uses an implicit uₙ = 0.
+
+Note that using a 2-by-1-digit division here does not mean calling ourselves
+recursively. Instead, we use an efficient direct hardware implementation of
+that operation.
+
+Note that because q is u/v rounded down, q·v must not exceed u: u ≥ q·v.
+If a guess q̂ is too big, it will not satisfy this test. Viewed a different way,
+the remainder r̂ for a given q̂ is u - q̂·v, which must be positive. If it is
+negative, then the guess q̂ is too big.
+
+This gives us a way to compute q. First compute q̂ with 2-by-1-digit division.
+Then, while u < q̂·v, decrement q̂; this loop executes at most twice, because
+q̂ ≤ q+2.
+
+
+Scaling Inputs
+
+The Good Guess Guarantee requires that the top digit of v (vₙ₋₁) be at least B/2.
+For example in base 10, ⌊172/19⌋ = 9, but ⌊18/1⌋ = 18: the guess is wildly off
+because the first digit 1 is smaller than B/2 = 5.
+
+We can ensure that v has a large top digit by multiplying both u and v by the
+right amount. Continuing the example, if we multiply both 172 and 19 by 3, we
+now have ⌊516/57⌋, the leading digit of v is now ≥ 5, and sure enough
+⌊51/5⌋ = 10 is much closer to the correct answer 9. It would be easier here
+to multiply by 4, because that can be done with a shift. Specifically, we can
+always count the number of leading zeros i in the first digit of v and then
+shift both u and v left by i bits.
+
+Having scaled u and v, the value ⌊u/v⌋ is unchanged, but the remainder will
+be scaled: 172 mod 19 is 1, but 516 mod 57 is 3. We have to divide the remainder
+by the scaling factor (shifting right i bits) when we finish.
+
+Note that these shifts happen before and after the entire division algorithm,
+not at each step in the per-digit iteration.
+
+Note the effect of scaling inputs on the size of the possible quotient.
+In the scaled u/v, u can gain a digit from scaling; v never does, because we
+pick the scaling factor to make v's top digit larger but without overflowing.
+If u and v have n+m and n digits after scaling, then:
+
+  • u < B^(n+m)               [B^(n+m) has n+m+1 digits]
+  • v ≥ B^n / 2               [vₙ₋₁ ≥ B/2, so vₙ₋₁·B^(n-1) ≥ B^n/2]
+  • u/v < B^(n+m) / (B^n / 2) [divide bounds for u, v]
+  • u/v < 2 B^m               [simplify]
+
+The quotient can still have m+1 significant digits, but if so the top digit
+must be a 1. This provides a different way to handle the first digit of the
+result: compare the top n digits of u against v and fill in either a 0 or a 1.
+
+
+Refining Guesses
+
+Before we check whether u < q̂·v, we can adjust our guess to change it from
+q̂ = ⌊uₙuₙ₋₁ / vₙ₋₁⌋ into the refined guess ⌊uₙuₙ₋₁uₙ₋₂ / vₙ₋₁vₙ₋₂⌋.
+Although not mentioned above, the Good Guess Guarantee also promises that this
+3-by-2-digit division guess is more precise and at most one away from the real
+answer q. The improvement from the 2-by-1 to the 3-by-2 guess can also be done
+without n-digit math.
+
+If we have a guess q̂ = ⌊uₙuₙ₋₁ / vₙ₋₁⌋ and we want to see if it also equal to
+⌊uₙuₙ₋₁uₙ₋₂ / vₙ₋₁vₙ₋₂⌋, we can use the same check we would for the full division:
+if uₙuₙ₋₁uₙ₋₂ < q̂·vₙ₋₁vₙ₋₂, then the guess is too large and should be reduced.
+
+Checking uₙuₙ₋₁uₙ₋₂ < q̂·vₙ₋₁vₙ₋₂ is the same as uₙuₙ₋₁uₙ₋₂ - q̂·vₙ₋₁vₙ₋₂ < 0,
+and
+
+	uₙuₙ₋₁uₙ₋₂ - q̂·vₙ₋₁vₙ₋₂ = (uₙuₙ₋₁·B + uₙ₋₂) - q̂·(vₙ₋₁·B + vₙ₋₂)
+	                          [splitting off the bottom digit]
+	                      = (uₙuₙ₋₁ - q̂·vₙ₋₁)·B + uₙ₋₂ - q̂·vₙ₋₂
+	                          [regrouping]
+
+The expression (uₙuₙ₋₁ - q̂·vₙ₋₁) is the remainder of uₙuₙ₋₁ / vₙ₋₁.
+If the initial guess returns both q̂ and its remainder r̂, then checking
+whether uₙuₙ₋₁uₙ₋₂ < q̂·vₙ₋₁vₙ₋₂ is the same as checking r̂·B + uₙ₋₂ < q̂·vₙ₋₂.
+
+If we find that r̂·B + uₙ₋₂ < q̂·vₙ₋₂, then we can adjust the guess by
+decrementing q̂ and adding vₙ₋₁ to r̂. We repeat until r̂·B + uₙ₋₂ ≥ q̂·vₙ₋₂.
+(As before, this fixup is only needed at most twice.)
+
+Now that q̂ = ⌊uₙuₙ₋₁uₙ₋₂ / vₙ₋₁vₙ₋₂⌋, as mentioned above it is at most one
+away from the correct q, and we've avoided doing any n-digit math.
+(If we need the new remainder, it can be computed as r̂·B + uₙ₋₂ - q̂·vₙ₋₂.)
+
+The final check u < q̂·v and the possible fixup must be done at full precision.
+For random inputs, a fixup at this step is exceedingly rare: the 3-by-2 guess
+is not often wrong at all. But still we must do the check. Note that since the
+3-by-2 guess is off by at most 1, it can be convenient to perform the final
+u < q̂·v as part of the computation of the remainder r = u - q̂·v. If the
+subtraction underflows, decremeting q̂ and adding one v back to r is enough to
+arrive at the final q, r.
+
+That's the entirety of long division: scale the inputs, and then loop over
+each output position, guessing, checking, and correcting the next output digit.
+
+For a 2n-digit number divided by an n-digit number (the worst size-n case for
+division complexity), this algorithm uses n+1 iterations, each of which must do
+at least the 1-by-n-digit multiplication q̂·v. That's O(n) iterations of
+O(n) time each, so O(n²) time overall.
+
+
+Recursive Division
+
+For very large inputs, it is possible to improve on the O(n²) algorithm.
+Let's call a group of n/2 real digits a (very) “wide digit”. We can run the
+standard long division algorithm explained above over the wide digits instead of
+the actual digits. This will result in many fewer steps, but the math involved in
+each step is more work.
+
+Where basic long division uses a 2-by-1-digit division to guess the initial q̂,
+the new algorithm must use a 2-by-1-wide-digit division, which is of course
+really an n-by-n/2-digit division. That's OK: if we implement n-digit division
+in terms of n/2-digit division, the recursion will terminate when the divisor
+becomes small enough to handle with standard long division or even with the
+2-by-1 hardware instruction.
+
+For example, here is a sketch of dividing 10 digits by 4, proceeding with
+wide digits corresponding to two regular digits. The first step, still special,
+must leave off a (regular) digit, dividing 5 by 4 and producing a 4-digit
+remainder less than v. The middle steps divide 6 digits by 4, guaranteed to
+produce two output digits each (one wide digit) with 4-digit remainders.
+The final step must use what it has: the 4-digit remainder plus one more,
+5 digits to divide by 4.
+
+	                       q₆ q₅ q₄ q₃ q₂ q₁ q₀
+	            _______________________________
+	v₃ v₂ v₁ v₀ ) u₉ u₈ u₇ u₆ u₅ u₄ u₃ u₂ u₁ u₀
+	              ↓  ↓  ↓  ↓  ↓  |  |  |  |  |
+	             [u₉ u₈ u₇ u₆ u₅]|  |  |  |  |
+	           - [    q₆q₅·v    ]|  |  |  |  |
+	           ----------------- ↓  ↓  |  |  |
+	                [    rem    |u₄ u₃]|  |  |
+	              - [     q₄q₃·v      ]|  |  |
+	              -------------------- ↓  ↓  |
+	                      [    rem    |u₂ u₁]|
+	                    - [     q₂q₁·v      ]|
+	                    -------------------- ↓
+	                            [    rem    |u₀]
+	                          - [     q₀·v     ]
+	                          ------------------
+	                               [    rem    ]
+
+An alternative would be to look ahead to how well n/2 divides into n+m and
+adjust the first step to use fewer digits as needed, making the first step
+more special to make the last step not special at all. For example, using the
+same input, we could choose to use only 4 digits in the first step, leaving
+a full wide digit for the last step:
+
+	                       q₆ q₅ q₄ q₃ q₂ q₁ q₀
+	            _______________________________
+	v₃ v₂ v₁ v₀ ) u₉ u₈ u₇ u₆ u₅ u₄ u₃ u₂ u₁ u₀
+	              ↓  ↓  ↓  ↓  |  |  |  |  |  |
+	             [u₉ u₈ u₇ u₆]|  |  |  |  |  |
+	           - [    q₆·v   ]|  |  |  |  |  |
+	           -------------- ↓  ↓  |  |  |  |
+	             [    rem    |u₅ u₄]|  |  |  |
+	           - [     q₅q₄·v      ]|  |  |  |
+	           -------------------- ↓  ↓  |  |
+	                   [    rem    |u₃ u₂]|  |
+	                 - [     q₃q₂·v      ]|  |
+	                 -------------------- ↓  ↓
+	                         [    rem    |u₁ u₀]
+	                       - [     q₁q₀·v      ]
+	                       ---------------------
+	                               [    rem    ]
+
+Today, the code in divRecursiveStep works like the first example. Perhaps in
+the future we will make it work like the alternative, to avoid a special case
+in the final iteration.
+
+Either way, each step is a 3-by-2-wide-digit division approximated first by
+a 2-by-1-wide-digit division, just as we did for regular digits in long division.
+Because the actual answer we want is a 3-by-2-wide-digit division, instead of
+multiplying q̂·v directly during the fixup, we can use the quick refinement
+from long division (an n/2-by-n/2 multiply) to correct q to its actual value
+and also compute the remainder (as mentioned above), and then stop after that,
+never doing a full n-by-n multiply.
+
+Instead of using an n-by-n/2-digit division to produce n/2 digits, we can add
+(not discard) one more real digit, doing an (n+1)-by-(n/2+1)-digit division that
+produces n/2+1 digits. That single extra digit tightens the Good Guess Guarantee
+to q ≤ q̂ ≤ q+1 and lets us drop long division's special treatment of the first
+digit. These benefits are discussed more after the Good Guess Guarantee proof
+below.
+
+
+How Fast is Recursive Division?
+
+For a 2n-by-n-digit division, this algorithm runs a 4-by-2 long division over
+wide digits, producing two wide digits plus a possible leading regular digit 1,
+which can be handled without a recursive call. That is, the algorithm uses two
+full iterations, each using an n-by-n/2-digit division and an n/2-by-n/2-digit
+multiplication, along with a few n-digit additions and subtractions. The standard
+n-by-n-digit multiplication algorithm requires O(n²) time, making the overall
+algorithm require time T(n) where
+
+	T(n) = 2T(n/2) + O(n) + O(n²)
+
+which, by the Bentley-Haken-Saxe theorem, ends up reducing to T(n) = O(n²).
+This is not an improvement over regular long division.
+
+When the number of digits n becomes large enough, Karatsuba's algorithm for
+multiplication can be used instead, which takes O(n^log₂3) = O(n^1.6) time.
+(Karatsuba multiplication is implemented in func karatsuba in nat.go.)
+That makes the overall recursive division algorithm take O(n^1.6) time as well,
+which is an improvement, but again only for large enough numbers.
+
+It is not critical to make sure that every recursion does only two recursive
+calls. While in general the number of recursive calls can change the time
+analysis, in this case doing three calls does not change the analysis:
+
+	T(n) = 3T(n/2) + O(n) + O(n^log₂3)
+
+ends up being T(n) = O(n^log₂3). Because the Karatsuba multiplication taking
+time O(n^log₂3) is itself doing 3 half-sized recursions, doing three for the
+division does not hurt the asymptotic performance. Of course, it is likely
+still faster in practice to do two.
+
+
+Proof of the Good Guess Guarantee
+
+Given numbers x, y, let us break them into the quotients and remainders when
+divided by some scaling factor S, with the added constraints that the quotient
+x/y and the high part of y are both less than some limit T, and that the high
+part of y is at least half as big as T.
+
+	x₁ = ⌊x/S⌋        y₁ = ⌊y/S⌋
+	x₀ = x mod S      y₀ = y mod S
+
+	x  = x₁·S + x₀    0 ≤ x₀ < S    x/y < T
+	y  = y₁·S + y₀    0 ≤ y₀ < S    T/2 ≤ y₁ < T
+
+And consider the two truncated quotients:
+
+	q = ⌊x/y⌋
+	q̂ = ⌊x₁/y₁⌋
+
+We will prove that q ≤ q̂ ≤ q+2.
+
+The guarantee makes no real demands on the scaling factor S: it is simply the
+magnitude of the digits cut from both x and y to produce x₁ and y₁.
+The guarantee makes only limited demands on T: it must be large enough to hold
+the quotient x/y, and y₁ must have roughly the same size.
+
+To apply to the earlier discussion of 2-by-1 guesses in long division,
+we would choose:
+
+	S  = Bⁿ⁻¹
+	T  = B
+	x  = u
+	x₁ = uₙuₙ₋₁
+	x₀ = uₙ₋₂...u₀
+	y  = v
+	y₁ = vₙ₋₁
+	y₀ = vₙ₋₂...u₀
+
+These simpler variables avoid repeating those longer expressions in the proof.
+
+Note also that, by definition, truncating division ⌊x/y⌋ satisfies
+
+	x/y - 1 < ⌊x/y⌋ ≤ x/y.
+
+This fact will be used a few times in the proofs.
+
+Proof that q ≤ q̂:
+
+	q̂·y₁ = ⌊x₁/y₁⌋·y₁                      [by definition, q̂ = ⌊x₁/y₁⌋]
+	     > (x₁/y₁ - 1)·y₁                  [x₁/y₁ - 1 < ⌊x₁/y₁⌋]
+	     = x₁ - y₁                         [distribute y₁]
+
+	So q̂·y₁ > x₁ - y₁.
+	Since q̂·y₁ is an integer, q̂·y₁ ≥ x₁ - y₁ + 1.
+
+	q̂ - q = q̂ - ⌊x/y⌋                      [by definition, q = ⌊x/y⌋]
+	      ≥ q̂ - x/y                        [⌊x/y⌋ < x/y]
+	      = (1/y)·(q̂·y - x)                [factor out 1/y]
+	      ≥ (1/y)·(q̂·y₁·S - x)             [y = y₁·S + y₀ ≥ y₁·S]
+	      ≥ (1/y)·((x₁ - y₁ + 1)·S - x)    [above: q̂·y₁ ≥ x₁ - y₁ + 1]
+	      = (1/y)·(x₁·S - y₁·S + S - x)    [distribute S]
+	      = (1/y)·(S - x₀ - y₁·S)          [-x = -x₁·S - x₀]
+	      > -y₁·S / y                      [x₀ < S, so S - x₀ < 0; drop it]
+	      ≥ -1                             [y₁·S ≤ y]
+
+	So q̂ - q > -1.
+	Since q̂ - q is an integer, q̂ - q ≥ 0, or equivalently q ≤ q̂.
+
+Proof that q̂ ≤ q+2:
+
+	x₁/y₁ - x/y = x₁·S/y₁·S - x/y          [multiply left term by S/S]
+	            ≤ x/y₁·S - x/y             [x₁S ≤ x]
+	            = (x/y)·(y/y₁·S - 1)       [factor out x/y]
+	            = (x/y)·((y - y₁·S)/y₁·S)  [move -1 into y/y₁·S fraction]
+	            = (x/y)·(y₀/y₁·S)          [y - y₁·S = y₀]
+	            = (x/y)·(1/y₁)·(y₀/S)      [factor out 1/y₁]
+	            < (x/y)·(1/y₁)             [y₀ < S, so y₀/S < 1]
+	            ≤ (x/y)·(2/T)              [y₁ ≥ T/2, so 1/y₁ ≤ 2/T]
+	            < T·(2/T)                  [x/y < T]
+	            = 2                        [T·(2/T) = 2]
+
+	So x₁/y₁ - x/y < 2.
+
+	q̂ - q = ⌊x₁/y₁⌋ - q                    [by definition, q̂ = ⌊x₁/y₁⌋]
+	      = ⌊x₁/y₁⌋ - ⌊x/y⌋                [by definition, q = ⌊x/y⌋]
+	      ≤ x₁/y₁ - ⌊x/y⌋                  [⌊x₁/y₁⌋ ≤ x₁/y₁]
+	      < x₁/y₁ - (x/y - 1)              [⌊x/y⌋ > x/y - 1]
+	      = (x₁/y₁ - x/y) + 1              [regrouping]
+	      < 2 + 1                          [above: x₁/y₁ - x/y < 2]
+	      = 3
+
+	So q̂ - q < 3.
+	Since q̂ - q is an integer, q̂ - q ≤ 2.
+
+Note that when x/y < T/2, the bounds tighten to x₁/y₁ - x/y < 1 and therefore
+q̂ - q ≤ 1.
+
+Note also that in the general case 2n-by-n division where we don't know that
+x/y < T, we do know that x/y < 2T, yielding the bound q̂ - q ≤ 4. So we could
+remove the special case first step of long division as long as we allow the
+first fixup loop to run up to four times. (Using a simple comparison to decide
+whether the first digit is 0 or 1 is still more efficient, though.)
+
+Finally, note that when dividing three leading base-B digits by two (scaled),
+we have T = B² and x/y < B = T/B, a much tighter bound than x/y < T.
+This in turn yields the much tighter bound x₁/y₁ - x/y < 2/B. This means that
+⌊x₁/y₁⌋ and ⌊x/y⌋ can only differ when x/y is less than 2/B greater than an
+integer. For random x and y, the chance of this is 2/B, or, for large B,
+approximately zero. This means that after we produce the 3-by-2 guess in the
+long division algorithm, the fixup loop essentially never runs.
+
+In the recursive algorithm, the extra digit in (2·⌊n/2⌋+1)-by-(⌊n/2⌋+1)-digit
+division has exactly the same effect: the probability of needing a fixup is the
+same 2/B. Even better, we can allow the general case x/y < 2T and the fixup
+probability only grows to 4/B, still essentially zero.
+
+
+References
+
+There are no great references for implementing long division; thus this comment.
+Here are some notes about what to expect from the obvious references.
+
+Knuth Volume 2 (Seminumerical Algorithms) section 4.3.1 is the usual canonical
+reference for long division, but that entire series is highly compressed, never
+repeating a necessary fact and leaving important insights to the exercises.
+For example, no rationale whatsoever is given for the calculation that extends
+q̂ from a 2-by-1 to a 3-by-2 guess, nor why it reduces the error bound.
+The proof that the calculation even has the desired effect is left to exercises.
+The solutions to those exercises provided at the back of the book are entirely
+calculations, still with no explanation as to what is going on or how you would
+arrive at the idea of doing those exact calculations. Nowhere is it mentioned
+that this test extends the 2-by-1 guess into a 3-by-2 guess. The proof of the
+Good Guess Guarantee is only for the 2-by-1 guess and argues by contradiction,
+making it difficult to understand how modifications like adding another digit
+or adjusting the quotient range affects the overall bound.
+
+All that said, Knuth remains the canonical reference. It is dense but packed
+full of information and references, and the proofs are simpler than many other
+presentations. The proofs above are reworkings of Knuth's to remove the
+arguments by contradiction and add explanations or steps that Knuth omitted.
+But beware of errors in older printings. Take the published errata with you.
+
+Brinch Hansen's “Multiple-length Division Revisited: a Tour of the Minefield”
+starts with a blunt critique of Knuth's presentation (among others) and then
+presents a more detailed and easier to follow treatment of long division,
+including an implementation in Pascal. But the algorithm and implementation
+work entirely in terms of 3-by-2 division, which is much less useful on modern
+hardware than an algorithm using 2-by-1 division. The proofs are a bit too
+focused on digit counting and seem needlessly complex, especially compared to
+the ones given above.
+
+Burnikel and Ziegler's “Fast Recursive Division” introduced the key insight of
+implementing division by an n-digit divisor using recursive calls to division
+by an n/2-digit divisor, relying on Karatsuba multiplication to yield a
+sub-quadratic run time. However, the presentation decisions are made almost
+entirely for the purpose of simplifying the run-time analysis, rather than
+simplifying the presentation. Instead of a single algorithm that loops over
+quotient digits, the paper presents two mutually-recursive algorithms, for
+2n-by-n and 3n-by-2n. The paper also does not present any general (n+m)-by-n
+algorithm.
+
+The proofs in the paper are remarkably complex, especially considering that
+the algorithm is at its core just long division on wide digits, so that the
+usual long division proofs apply essentially unaltered.
+*/
+
+package big
+
+import "math/bits"
+
+// div returns q, r such that q = ⌊u/v⌋ and r = u%v = u - q·v.
+// It uses z and z2 as the storage for q and r.
+func (z nat) div(z2, u, v nat) (q, r nat) {
+	if len(v) == 0 {
+		panic("division by zero")
+	}
+
+	if u.cmp(v) < 0 {
+		q = z[:0]
+		r = z2.set(u)
+		return
+	}
+
+	if len(v) == 1 {
+		// Short division: long optimized for a single-word divisor.
+		// In that case, the 2-by-1 guess is all we need at each step.
+		var r2 Word
+		q, r2 = z.divW(u, v[0])
+		r = z2.setWord(r2)
+		return
+	}
+
+	q, r = z.divLarge(z2, u, v)
+	return
+}
+
+// divW returns q, r such that q = ⌊x/y⌋ and r = x%y = x - q·y.
+// It uses z as the storage for q.
+// Note that y is a single digit (Word), not a big number.
+func (z nat) divW(x nat, y Word) (q nat, r Word) {
+	m := len(x)
+	switch {
+	case y == 0:
+		panic("division by zero")
+	case y == 1:
+		q = z.set(x) // result is x
+		return
+	case m == 0:
+		q = z[:0] // result is 0
+		return
+	}
+	// m > 0
+	z = z.make(m)
+	r = divWVW(z, 0, x, y)
+	q = z.norm()
+	return
+}
+
+// modW returns x % d.
+func (x nat) modW(d Word) (r Word) {
+	// TODO(agl): we don't actually need to store the q value.
+	var q nat
+	q = q.make(len(x))
+	return divWVW(q, 0, x, d)
+}
+
+// divWVW overwrites z with ⌊x/y⌋, returning the remainder r.
+// The caller must ensure that len(z) = len(x).
+func divWVW(z []Word, xn Word, x []Word, y Word) (r Word) {
+	r = xn
+	if len(x) == 1 {
+		qq, rr := bits.Div(uint(r), uint(x[0]), uint(y))
+		z[0] = Word(qq)
+		return Word(rr)
+	}
+	rec := reciprocalWord(y)
+	for i := len(z) - 1; i >= 0; i-- {
+		z[i], r = divWW(r, x[i], y, rec)
+	}
+	return r
+}
+
+// div returns q, r such that q = ⌊uIn/vIn⌋ and r = uIn%vIn = uIn - q·vIn.
+// It uses z and u as the storage for q and r.
+// The caller must ensure that len(vIn) ≥ 2 (use divW otherwise)
+// and that len(uIn) ≥ len(vIn) (the answer is 0, uIn otherwise).
+func (z nat) divLarge(u, uIn, vIn nat) (q, r nat) {
+	n := len(vIn)
+	m := len(uIn) - n
+
+	// Scale the inputs so vIn's top bit is 1 (see “Scaling Inputs” above).
+	// vIn is treated as a read-only input (it may be in use by another
+	// goroutine), so we must make a copy.
+	// uIn is copied to u.
+	shift := nlz(vIn[n-1])
+	vp := getNat(n)
+	v := *vp
+	shlVU(v, vIn, shift)
+	u = u.make(len(uIn) + 1)
+	u[len(uIn)] = shlVU(u[0:len(uIn)], uIn, shift)
+
+	// The caller should not pass aliased z and u, since those are
+	// the two different outputs, but correct just in case.
+	if alias(z, u) {
+		z = nil
+	}
+	q = z.make(m + 1)
+
+	// Use basic or recursive long division depending on size.
+	if n < divRecursiveThreshold {
+		q.divBasic(u, v)
+	} else {
+		q.divRecursive(u, v)
+	}
+	putNat(vp)
+
+	q = q.norm()
+
+	// Undo scaling of remainder.
+	shrVU(u, u, shift)
+	r = u.norm()
+
+	return q, r
+}
+
+// divBasic implements long division as described above.
+// It overwrites q with ⌊u/v⌋ and overwrites u with the remainder r.
+// q must be large enough to hold ⌊u/v⌋.
+func (q nat) divBasic(u, v nat) {
+	n := len(v)
+	m := len(u) - n
+
+	qhatvp := getNat(n + 1)
+	qhatv := *qhatvp
+
+	// Set up for divWW below, precomputing reciprocal argument.
+	vn1 := v[n-1]
+	rec := reciprocalWord(vn1)
+
+	// Compute each digit of quotient.
+	for j := m; j >= 0; j-- {
+		// Compute the 2-by-1 guess q̂.
+		// The first iteration must invent a leading 0 for u.
+		qhat := Word(_M)
+		var ujn Word
+		if j+n < len(u) {
+			ujn = u[j+n]
+		}
+
+		// ujn ≤ vn1, or else q̂ would be more than one digit.
+		// For ujn == vn1, we set q̂ to the max digit M above.
+		// Otherwise, we compute the 2-by-1 guess.
+		if ujn != vn1 {
+			var rhat Word
+			qhat, rhat = divWW(ujn, u[j+n-1], vn1, rec)
+
+			// Refine q̂ to a 3-by-2 guess. See “Refining Guesses” above.
+			vn2 := v[n-2]
+			x1, x2 := mulWW(qhat, vn2)
+			ujn2 := u[j+n-2]
+			for greaterThan(x1, x2, rhat, ujn2) { // x1x2 > r̂ u[j+n-2]
+				qhat--
+				prevRhat := rhat
+				rhat += vn1
+				// If r̂  overflows, then
+				// r̂ u[j+n-2]v[n-1] is now definitely > x1 x2.
+				if rhat < prevRhat {
+					break
+				}
+				// TODO(rsc): No need for a full mulWW.
+				// x2 += vn2; if x2 overflows, x1++
+				x1, x2 = mulWW(qhat, vn2)
+			}
+		}
+
+		// Compute q̂·v.
+		qhatv[n] = mulAddVWW(qhatv[0:n], v, qhat, 0)
+		qhl := len(qhatv)
+		if j+qhl > len(u) && qhatv[n] == 0 {
+			qhl--
+		}
+
+		// Subtract q̂·v from the current section of u.
+		// If it underflows, q̂·v > u, which we fix up
+		// by decrementing q̂ and adding v back.
+		c := subVV(u[j:j+qhl], u[j:], qhatv)
+		if c != 0 {
+			c := addVV(u[j:j+n], u[j:], v)
+			// If n == qhl, the carry from subVV and the carry from addVV
+			// cancel out and don't affect u[j+n].
+			if n < qhl {
+				u[j+n] += c
+			}
+			qhat--
+		}
+
+		// Save quotient digit.
+		// Caller may know the top digit is zero and not leave room for it.
+		if j == m && m == len(q) && qhat == 0 {
+			continue
+		}
+		q[j] = qhat
+	}
+
+	putNat(qhatvp)
+}
+
+// greaterThan reports whether the two digit numbers x1 x2 > y1 y2.
+// TODO(rsc): In contradiction to most of this file, x1 is the high
+// digit and x2 is the low digit. This should be fixed.
+func greaterThan(x1, x2, y1, y2 Word) bool {
+	return x1 > y1 || x1 == y1 && x2 > y2
+}
+
+// divRecursiveThreshold is the number of divisor digits
+// at which point divRecursive is faster than divBasic.
+const divRecursiveThreshold = 100
+
+// divRecursive implements recursive division as described above.
+// It overwrites z with ⌊u/v⌋ and overwrites u with the remainder r.
+// z must be large enough to hold ⌊u/v⌋.
+// This function is just for allocating and freeing temporaries
+// around divRecursiveStep, the real implementation.
+func (z nat) divRecursive(u, v nat) {
+	// Recursion depth is (much) less than 2 log₂(len(v)).
+	// Allocate a slice of temporaries to be reused across recursion,
+	// plus one extra temporary not live across the recursion.
+	recDepth := 2 * bits.Len(uint(len(v)))
+	tmp := getNat(3 * len(v))
+	temps := make([]*nat, recDepth)
+
+	z.clear()
+	z.divRecursiveStep(u, v, 0, tmp, temps)
+
+	// Free temporaries.
+	for _, n := range temps {
+		if n != nil {
+			putNat(n)
+		}
+	}
+	putNat(tmp)
+}
+
+// divRecursiveStep is the actual implementation of recursive division.
+// It adds ⌊u/v⌋ to z and overwrites u with the remainder r.
+// z must be large enough to hold ⌊u/v⌋.
+// It uses temps[depth] (allocating if needed) as a temporary live across
+// the recursive call. It also uses tmp, but not live across the recursion.
+func (z nat) divRecursiveStep(u, v nat, depth int, tmp *nat, temps []*nat) {
+	// u is a subsection of the original and may have leading zeros.
+	// TODO(rsc): The v = v.norm() is useless and should be removed.
+	// We know (and require) that v's top digit is ≥ B/2.
+	u = u.norm()
+	v = v.norm()
+	if len(u) == 0 {
+		z.clear()
+		return
+	}
+
+	// Fall back to basic division if the problem is now small enough.
+	n := len(v)
+	if n < divRecursiveThreshold {
+		z.divBasic(u, v)
+		return
+	}
+
+	// Nothing to do if u is shorter than v (implies u < v).
+	m := len(u) - n
+	if m < 0 {
+		return
+	}
+
+	// We consider B digits in a row as a single wide digit.
+	// (See “Recursive Division” above.)
+	//
+	// TODO(rsc): rename B to Wide, to avoid confusion with _B,
+	// which is something entirely different.
+	// TODO(rsc): Look into whether using ⌈n/2⌉ is better than ⌊n/2⌋.
+	B := n / 2
+
+	// Allocate a nat for qhat below.
+	if temps[depth] == nil {
+		temps[depth] = getNat(n) // TODO(rsc): Can be just B+1.
+	} else {
+		*temps[depth] = temps[depth].make(B + 1)
+	}
+
+	// Compute each wide digit of the quotient.
+	//
+	// TODO(rsc): Change the loop to be
+	//	for j := (m+B-1)/B*B; j > 0; j -= B {
+	// which will make the final step a regular step, letting us
+	// delete what amounts to an extra copy of the loop body below.
+	j := m
+	for j > B {
+		// Divide u[j-B:j+n] (3 wide digits) by v (2 wide digits).
+		// First make the 2-by-1-wide-digit guess using a recursive call.
+		// Then extend the guess to the full 3-by-2 (see “Refining Guesses”).
+		//
+		// For the 2-by-1-wide-digit guess, instead of doing 2B-by-B-digit,
+		// we use a (2B+1)-by-(B+1) digit, which handles the possibility that
+		// the result has an extra leading 1 digit as well as guaranteeing
+		// that the computed q̂ will be off by at most 1 instead of 2.
+
+		// s is the number of digits to drop from the 3B- and 2B-digit chunks.
+		// We drop B-1 to be left with 2B+1 and B+1.
+		s := (B - 1)
+
+		// uu is the up-to-3B-digit section of u we are working on.
+		uu := u[j-B:]
+
+		// Compute the 2-by-1 guess q̂, leaving r̂ in uu[s:B+n].
+		qhat := *temps[depth]
+		qhat.clear()
+		qhat.divRecursiveStep(uu[s:B+n], v[s:], depth+1, tmp, temps)
+		qhat = qhat.norm()
+
+		// Extend to a 3-by-2 quotient and remainder.
+		// Because divRecursiveStep overwrote the top part of uu with
+		// the remainder r̂, the full uu already contains the equivalent
+		// of r̂·B + uₙ₋₂ from the “Refining Guesses” discussion.
+		// Subtracting q̂·vₙ₋₂ from it will compute the full-length remainder.
+		// If that subtraction underflows, q̂·v > u, which we fix up
+		// by decrementing q̂ and adding v back, same as in long division.
+
+		// TODO(rsc): Instead of subtract and fix-up, this code is computing
+		// q̂·vₙ₋₂ and decrementing q̂ until that product is ≤ u.
+		// But we can do the subtraction directly, as in the comment above
+		// and in long division, because we know that q̂ is wrong by at most one.
+		qhatv := tmp.make(3 * n)
+		qhatv.clear()
+		qhatv = qhatv.mul(qhat, v[:s])
+		for i := 0; i < 2; i++ {
+			e := qhatv.cmp(uu.norm())
+			if e <= 0 {
+				break
+			}
+			subVW(qhat, qhat, 1)
+			c := subVV(qhatv[:s], qhatv[:s], v[:s])
+			if len(qhatv) > s {
+				subVW(qhatv[s:], qhatv[s:], c)
+			}
+			addAt(uu[s:], v[s:], 0)
+		}
+		if qhatv.cmp(uu.norm()) > 0 {
+			panic("impossible")
+		}
+		c := subVV(uu[:len(qhatv)], uu[:len(qhatv)], qhatv)
+		if c > 0 {
+			subVW(uu[len(qhatv):], uu[len(qhatv):], c)
+		}
+		addAt(z, qhat, j-B)
+		j -= B
+	}
+
+	// TODO(rsc): Rewrite loop as described above and delete all this code.
+
+	// Now u < (v< 0 {
+			subVW(qhat, qhat, 1)
+			c := subVV(qhatv[:s], qhatv[:s], v[:s])
+			if len(qhatv) > s {
+				subVW(qhatv[s:], qhatv[s:], c)
+			}
+			addAt(u[s:], v[s:], 0)
+		}
+	}
+	if qhatv.cmp(u.norm()) > 0 {
+		panic("impossible")
+	}
+	c := subVV(u[0:len(qhatv)], u[0:len(qhatv)], qhatv)
+	if c > 0 {
+		c = subVW(u[len(qhatv):], u[len(qhatv):], c)
+	}
+	if c > 0 {
+		panic("impossible")
+	}
+
+	// Done!
+	addAt(z, qhat.norm(), 0)
+}
diff --git a/src/math/floor_ppc64x.s b/src/math/floor_ppc64x.s
index 29b92a62c34..584c27e28f6 100644
--- a/src/math/floor_ppc64x.s
+++ b/src/math/floor_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/math/modf_ppc64x.s b/src/math/modf_ppc64x.s
index caa435eef91..1303067661c 100644
--- a/src/math/modf_ppc64x.s
+++ b/src/math/modf_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/math/rand/rand.go b/src/math/rand/rand.go
index 8179d9f4649..13f20ca5efb 100644
--- a/src/math/rand/rand.go
+++ b/src/math/rand/rand.go
@@ -12,9 +12,6 @@
 // The default Source is safe for concurrent use by multiple goroutines, but
 // Sources created by NewSource are not.
 //
-// Mathematical interval notation such as [0, n) is used throughout the
-// documentation for this package.
-//
 // This package's outputs might be easily predictable regardless of how it's
 // seeded. For random numbers suitable for security-sensitive work, see the
 // crypto/rand package.
@@ -106,7 +103,7 @@ func (r *Rand) Int() int {
 	return int(u << 1 >> 1) // clear sign bit if int == int32
 }
 
-// Int63n returns, as an int64, a non-negative pseudo-random number in [0,n).
+// Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Int63n(n int64) int64 {
 	if n <= 0 {
@@ -123,7 +120,7 @@ func (r *Rand) Int63n(n int64) int64 {
 	return v % n
 }
 
-// Int31n returns, as an int32, a non-negative pseudo-random number in [0,n).
+// Int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Int31n(n int32) int32 {
 	if n <= 0 {
@@ -140,7 +137,7 @@ func (r *Rand) Int31n(n int32) int32 {
 	return v % n
 }
 
-// int31n returns, as an int32, a non-negative pseudo-random number in [0,n).
+// int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n).
 // n must be > 0, but int31n does not check this; the caller must ensure it.
 // int31n exists because Int31n is inefficient, but Go 1 compatibility
 // requires that the stream of values produced by math/rand remain unchanged.
@@ -164,7 +161,7 @@ func (r *Rand) int31n(n int32) int32 {
 	return int32(prod >> 32)
 }
 
-// Intn returns, as an int, a non-negative pseudo-random number in [0,n).
+// Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Intn(n int) int {
 	if n <= 0 {
@@ -176,7 +173,7 @@ func (r *Rand) Intn(n int) int {
 	return int(r.Int63n(int64(n)))
 }
 
-// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0).
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0).
 func (r *Rand) Float64() float64 {
 	// A clearer, simpler implementation would be:
 	//	return float64(r.Int63n(1<<53)) / (1<<53)
@@ -202,7 +199,7 @@ again:
 	return f
 }
 
-// Float32 returns, as a float32, a pseudo-random number in [0.0,1.0).
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0).
 func (r *Rand) Float32() float32 {
 	// Same rationale as in Float64: we want to preserve the Go 1 value
 	// stream except we want to fix it not to return 1.0
@@ -215,7 +212,8 @@ again:
 	return f
 }
 
-// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers [0,n).
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
+// in the half-open interval [0,n).
 func (r *Rand) Perm(n int) []int {
 	m := make([]int, n)
 	// In the following loop, the iteration when i=0 always swaps m[0] with m[0].
@@ -323,31 +321,31 @@ func Int31() int32 { return globalRand.Int31() }
 // Int returns a non-negative pseudo-random int from the default Source.
 func Int() int { return globalRand.Int() }
 
-// Int63n returns, as an int64, a non-negative pseudo-random number in [0,n)
+// Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Int63n(n int64) int64 { return globalRand.Int63n(n) }
 
-// Int31n returns, as an int32, a non-negative pseudo-random number in [0,n)
+// Int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Int31n(n int32) int32 { return globalRand.Int31n(n) }
 
-// Intn returns, as an int, a non-negative pseudo-random number in [0,n)
+// Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Intn(n int) int { return globalRand.Intn(n) }
 
-// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0)
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0)
 // from the default Source.
 func Float64() float64 { return globalRand.Float64() }
 
-// Float32 returns, as a float32, a pseudo-random number in [0.0,1.0)
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0)
 // from the default Source.
 func Float32() float32 { return globalRand.Float32() }
 
-// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers [0,n)
-// from the default Source.
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
+// in the half-open interval [0,n) from the default Source.
 func Perm(n int) []int { return globalRand.Perm(n) }
 
 // Shuffle pseudo-randomizes the order of elements using the default Source.
diff --git a/src/math/sqrt_mipsx.s b/src/math/sqrt_mipsx.s
index c619c19ec22..291d4af39cf 100644
--- a/src/math/sqrt_mipsx.s
+++ b/src/math/sqrt_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/math/sqrt_ppc64x.s b/src/math/sqrt_ppc64x.s
index 174b63e35a5..c929da2159a 100644
--- a/src/math/sqrt_ppc64x.s
+++ b/src/math/sqrt_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/math/sqrt_riscv64.s b/src/math/sqrt_riscv64.s
index f223510c424..0dbdbc99ed6 100644
--- a/src/math/sqrt_riscv64.s
+++ b/src/math/sqrt_riscv64.s
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build riscv64
-
 #include "textflag.h"
 
 // func archSqrt(x float64) float64
diff --git a/src/mime/type.go b/src/mime/type.go
index 9bbbf216a1d..26424339af8 100644
--- a/src/mime/type.go
+++ b/src/mime/type.go
@@ -96,9 +96,11 @@ func initMime() {
 // Extensions are looked up first case-sensitively, then case-insensitively.
 //
 // The built-in table is small but on unix it is augmented by the local
-// system's mime.types file(s) if available under one or more of these
-// names:
+// system's MIME-info database or mime.types file(s) if available under one or
+// more of these names:
 //
+//   /usr/local/share/mime/globs2
+//   /usr/share/mime/globs2
 //   /etc/mime.types
 //   /etc/apache2/mime.types
 //   /etc/apache/mime.types
diff --git a/src/net/dial_test.go b/src/net/dial_test.go
index 394bdb047e7..723038c7a22 100644
--- a/src/net/dial_test.go
+++ b/src/net/dial_test.go
@@ -155,40 +155,27 @@ func slowDialTCP(ctx context.Context, network string, laddr, raddr *TCPAddr) (*T
 	return c, err
 }
 
-func dialClosedPort(t *testing.T) (actual, expected time.Duration) {
-	// Estimate the expected time for this platform.
-	// On Windows, dialing a closed port takes roughly 1 second,
-	// but other platforms should be instantaneous.
-	if runtime.GOOS == "windows" {
-		expected = 1500 * time.Millisecond
-	} else if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
-		expected = 150 * time.Millisecond
-	} else {
-		expected = 95 * time.Millisecond
-	}
+func dialClosedPort(t *testing.T) (dialLatency time.Duration) {
+	// On most platforms, dialing a closed port should be nearly instantaneous —
+	// less than a few hundred milliseconds. However, on some platforms it may be
+	// much slower: on Windows and OpenBSD, it has been observed to take up to a
+	// few seconds.
 
 	l, err := Listen("tcp", "127.0.0.1:0")
 	if err != nil {
-		t.Logf("dialClosedPort: Listen failed: %v", err)
-		return 999 * time.Hour, expected
+		t.Fatalf("dialClosedPort: Listen failed: %v", err)
 	}
 	addr := l.Addr().String()
 	l.Close()
-	// On OpenBSD, interference from TestTCPSelfConnect is mysteriously
-	// causing the first attempt to hang for a few seconds, so we throw
-	// away the first result and keep the second.
-	for i := 1; ; i++ {
-		startTime := time.Now()
-		c, err := Dial("tcp", addr)
-		if err == nil {
-			c.Close()
-		}
-		elapsed := time.Now().Sub(startTime)
-		if i == 2 {
-			t.Logf("dialClosedPort: measured delay %v", elapsed)
-			return elapsed, expected
-		}
+
+	startTime := time.Now()
+	c, err := Dial("tcp", addr)
+	if err == nil {
+		c.Close()
 	}
+	elapsed := time.Now().Sub(startTime)
+	t.Logf("dialClosedPort: measured delay %v", elapsed)
+	return elapsed
 }
 
 func TestDialParallel(t *testing.T) {
@@ -198,10 +185,7 @@ func TestDialParallel(t *testing.T) {
 		t.Skip("both IPv4 and IPv6 are required")
 	}
 
-	closedPortDelay, expectClosedPortDelay := dialClosedPort(t)
-	if closedPortDelay > expectClosedPortDelay {
-		t.Errorf("got %v; want <= %v", closedPortDelay, expectClosedPortDelay)
-	}
+	closedPortDelay := dialClosedPort(t)
 
 	const instant time.Duration = 0
 	const fallbackDelay = 200 * time.Millisecond
@@ -656,15 +640,7 @@ func TestDialerLocalAddr(t *testing.T) {
 		}
 		c, err := d.Dial(tt.network, addr)
 		if err == nil && tt.error != nil || err != nil && tt.error == nil {
-			// A suspected kernel bug in macOS 10.12 occasionally results in
-			// timeout errors when dialing address ::1. The errors have not
-			// been observed on newer versions of the OS, so we don't plan to work
-			// around them. See https://golang.org/issue/22019.
-			if tt.raddr == "::1" && os.Getenv("GO_BUILDER_NAME") == "darwin-amd64-10_12" && os.IsTimeout(err) {
-				t.Logf("ignoring timeout error on Darwin; see https://golang.org/issue/22019")
-			} else {
-				t.Errorf("%s %v->%s: got %v; want %v", tt.network, tt.laddr, tt.raddr, err, tt.error)
-			}
+			t.Errorf("%s %v->%s: got %v; want %v", tt.network, tt.laddr, tt.raddr, err, tt.error)
 		}
 		if err != nil {
 			if perr := parseDialError(err); perr != nil {
@@ -683,10 +659,7 @@ func TestDialerDualStack(t *testing.T) {
 		t.Skip("both IPv4 and IPv6 are required")
 	}
 
-	closedPortDelay, expectClosedPortDelay := dialClosedPort(t)
-	if closedPortDelay > expectClosedPortDelay {
-		t.Errorf("got %v; want <= %v", closedPortDelay, expectClosedPortDelay)
-	}
+	closedPortDelay := dialClosedPort(t)
 
 	origTestHookLookupIP := testHookLookupIP
 	defer func() { testHookLookupIP = origTestHookLookupIP }()
diff --git a/src/net/dnsclient_unix_test.go b/src/net/dnsclient_unix_test.go
index ec690a1c0cf..350ad5def79 100644
--- a/src/net/dnsclient_unix_test.go
+++ b/src/net/dnsclient_unix_test.go
@@ -1799,3 +1799,325 @@ func TestPTRandNonPTR(t *testing.T) {
 		t.Errorf("names = %q; want %q", names, want)
 	}
 }
+
+func TestCVE202133195(t *testing.T) {
+	fake := fakeDNSServer{
+		rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) {
+			r := dnsmessage.Message{
+				Header: dnsmessage.Header{
+					ID:                 q.Header.ID,
+					Response:           true,
+					RCode:              dnsmessage.RCodeSuccess,
+					RecursionAvailable: true,
+				},
+				Questions: q.Questions,
+			}
+			switch q.Questions[0].Type {
+			case dnsmessage.TypeCNAME:
+				r.Answers = []dnsmessage.Resource{}
+			case dnsmessage.TypeA: // CNAME lookup uses a A/AAAA as a proxy
+				r.Answers = append(r.Answers,
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName(".golang.org."),
+							Type:   dnsmessage.TypeA,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.AResource{
+							A: TestAddr,
+						},
+					},
+				)
+			case dnsmessage.TypeSRV:
+				n := q.Questions[0].Name
+				if n.String() == "_hdr._tcp.golang.org." {
+					n = dnsmessage.MustNewName(".golang.org.")
+				}
+				r.Answers = append(r.Answers,
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   n,
+							Type:   dnsmessage.TypeSRV,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.SRVResource{
+							Target: dnsmessage.MustNewName(".golang.org."),
+						},
+					},
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   n,
+							Type:   dnsmessage.TypeSRV,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.SRVResource{
+							Target: dnsmessage.MustNewName("good.golang.org."),
+						},
+					},
+				)
+			case dnsmessage.TypeMX:
+				r.Answers = append(r.Answers,
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName(".golang.org."),
+							Type:   dnsmessage.TypeMX,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.MXResource{
+							MX: dnsmessage.MustNewName(".golang.org."),
+						},
+					},
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName("good.golang.org."),
+							Type:   dnsmessage.TypeMX,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.MXResource{
+							MX: dnsmessage.MustNewName("good.golang.org."),
+						},
+					},
+				)
+			case dnsmessage.TypeNS:
+				r.Answers = append(r.Answers,
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName(".golang.org."),
+							Type:   dnsmessage.TypeNS,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.NSResource{
+							NS: dnsmessage.MustNewName(".golang.org."),
+						},
+					},
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName("good.golang.org."),
+							Type:   dnsmessage.TypeNS,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.NSResource{
+							NS: dnsmessage.MustNewName("good.golang.org."),
+						},
+					},
+				)
+			case dnsmessage.TypePTR:
+				r.Answers = append(r.Answers,
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName(".golang.org."),
+							Type:   dnsmessage.TypePTR,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.PTRResource{
+							PTR: dnsmessage.MustNewName(".golang.org."),
+						},
+					},
+					dnsmessage.Resource{
+						Header: dnsmessage.ResourceHeader{
+							Name:   dnsmessage.MustNewName("good.golang.org."),
+							Type:   dnsmessage.TypePTR,
+							Class:  dnsmessage.ClassINET,
+							Length: 4,
+						},
+						Body: &dnsmessage.PTRResource{
+							PTR: dnsmessage.MustNewName("good.golang.org."),
+						},
+					},
+				)
+			}
+			return r, nil
+		},
+	}
+
+	r := Resolver{PreferGo: true, Dial: fake.DialContext}
+	// Change the default resolver to match our manipulated resolver
+	originalDefault := DefaultResolver
+	DefaultResolver = &r
+	defer func() { DefaultResolver = originalDefault }()
+	// Redirect host file lookups.
+	defer func(orig string) { testHookHostsPath = orig }(testHookHostsPath)
+	testHookHostsPath = "testdata/hosts"
+
+	tests := []struct {
+		name string
+		f    func(*testing.T)
+	}{
+		{
+			name: "CNAME",
+			f: func(t *testing.T) {
+				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "golang.org"}
+				_, err := r.LookupCNAME(context.Background(), "golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				_, err = LookupCNAME("golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+			},
+		},
+		{
+			name: "SRV (bad record)",
+			f: func(t *testing.T) {
+				expected := []*SRV{
+					{
+						Target: "good.golang.org.",
+					},
+				}
+				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "golang.org"}
+				_, records, err := r.LookupSRV(context.Background(), "target", "tcp", "golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+				_, records, err = LookupSRV("target", "tcp", "golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Errorf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+			},
+		},
+		{
+			name: "SRV (bad header)",
+			f: func(t *testing.T) {
+				_, _, err := r.LookupSRV(context.Background(), "hdr", "tcp", "golang.org.")
+				if expected := "lookup golang.org.: SRV header name is invalid"; err == nil || err.Error() != expected {
+					t.Errorf("Resolver.LookupSRV returned unexpected error, got %q, want %q", err, expected)
+				}
+				_, _, err = LookupSRV("hdr", "tcp", "golang.org.")
+				if expected := "lookup golang.org.: SRV header name is invalid"; err == nil || err.Error() != expected {
+					t.Errorf("LookupSRV returned unexpected error, got %q, want %q", err, expected)
+				}
+			},
+		},
+		{
+			name: "MX",
+			f: func(t *testing.T) {
+				expected := []*MX{
+					{
+						Host: "good.golang.org.",
+					},
+				}
+				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "golang.org"}
+				records, err := r.LookupMX(context.Background(), "golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+				records, err = LookupMX("golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+			},
+		},
+		{
+			name: "NS",
+			f: func(t *testing.T) {
+				expected := []*NS{
+					{
+						Host: "good.golang.org.",
+					},
+				}
+				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "golang.org"}
+				records, err := r.LookupNS(context.Background(), "golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+				records, err = LookupNS("golang.org")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+			},
+		},
+		{
+			name: "Addr",
+			f: func(t *testing.T) {
+				expected := []string{"good.golang.org."}
+				expectedErr := &DNSError{Err: errMalformedDNSRecordsDetail, Name: "192.0.2.42"}
+				records, err := r.LookupAddr(context.Background(), "192.0.2.42")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+				records, err = LookupAddr("192.0.2.42")
+				if err.Error() != expectedErr.Error() {
+					t.Fatalf("unexpected error: %s", err)
+				}
+				if !reflect.DeepEqual(records, expected) {
+					t.Error("Unexpected record set")
+				}
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, tc.f)
+	}
+
+}
+
+func TestNullMX(t *testing.T) {
+	fake := fakeDNSServer{
+		rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) {
+			r := dnsmessage.Message{
+				Header: dnsmessage.Header{
+					ID:       q.Header.ID,
+					Response: true,
+					RCode:    dnsmessage.RCodeSuccess,
+				},
+				Questions: q.Questions,
+				Answers: []dnsmessage.Resource{
+					{
+						Header: dnsmessage.ResourceHeader{
+							Name:  q.Questions[0].Name,
+							Type:  dnsmessage.TypeMX,
+							Class: dnsmessage.ClassINET,
+						},
+						Body: &dnsmessage.MXResource{
+							MX: dnsmessage.MustNewName("."),
+						},
+					},
+				},
+			}
+			return r, nil
+		},
+	}
+	r := Resolver{PreferGo: true, Dial: fake.DialContext}
+	rrset, err := r.LookupMX(context.Background(), "golang.org")
+	if err != nil {
+		t.Fatalf("LookupMX: %v", err)
+	}
+	if want := []*MX{&MX{Host: "."}}; !reflect.DeepEqual(rrset, want) {
+		records := []string{}
+		for _, rr := range rrset {
+			records = append(records, fmt.Sprintf("%v", rr))
+		}
+		t.Errorf("records = [%v]; want [%v]", strings.Join(records, " "), want[0])
+	}
+}
diff --git a/src/net/hosts_test.go b/src/net/hosts_test.go
index f850e2fccfd..19c43999f92 100644
--- a/src/net/hosts_test.go
+++ b/src/net/hosts_test.go
@@ -36,7 +36,7 @@ var lookupStaticHostTests = []struct {
 		},
 	},
 	{
-		"testdata/ipv4-hosts", // see golang.org/issue/8996
+		"testdata/ipv4-hosts",
 		[]staticHostEntry{
 			{"localhost", []string{"127.0.0.1", "127.0.0.2", "127.0.0.3"}},
 			{"localhost.localdomain", []string{"127.0.0.3"}},
@@ -102,7 +102,7 @@ var lookupStaticAddrTests = []struct {
 		},
 	},
 	{
-		"testdata/ipv4-hosts", // see golang.org/issue/8996
+		"testdata/ipv4-hosts",
 		[]staticHostEntry{
 			{"127.0.0.1", []string{"localhost"}},
 			{"127.0.0.2", []string{"localhost"}},
diff --git a/src/net/http/client.go b/src/net/http/client.go
index 82e665829e9..4d380c65db9 100644
--- a/src/net/http/client.go
+++ b/src/net/http/client.go
@@ -17,6 +17,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"net/http/internal/ascii"
 	"net/url"
 	"reflect"
 	"sort"
@@ -432,8 +433,7 @@ func basicAuth(username, password string) string {
 // An error is returned if there were too many redirects or if there
 // was an HTTP protocol error. A non-2xx response doesn't cause an
 // error. Any returned error will be of type *url.Error. The url.Error
-// value's Timeout method will report true if request timed out or was
-// canceled.
+// value's Timeout method will report true if the request timed out.
 //
 // When err is nil, resp always contains a non-nil resp.Body.
 // Caller should close resp.Body when done reading from it.
@@ -547,7 +547,10 @@ func urlErrorOp(method string) string {
 	if method == "" {
 		return "Get"
 	}
-	return method[:1] + strings.ToLower(method[1:])
+	if lowerMethod, ok := ascii.ToLower(method); ok {
+		return method[:1] + lowerMethod[1:]
+	}
+	return method
 }
 
 // Do sends an HTTP request and returns an HTTP response, following
@@ -585,8 +588,7 @@ func urlErrorOp(method string) string {
 // standard library body types.
 //
 // Any returned error will be of type *url.Error. The url.Error
-// value's Timeout method will report true if request timed out or was
-// canceled.
+// value's Timeout method will report true if the request timed out.
 func (c *Client) Do(req *Request) (*Response, error) {
 	return c.do(req)
 }
@@ -725,7 +727,6 @@ func (c *Client) do(req *Request) (retres *Response, reterr error) {
 			reqBodyClosed = true
 			if !deadline.IsZero() && didTimeout() {
 				err = &httpError{
-					// TODO: early in cycle: s/Client.Timeout exceeded/timeout or context cancellation/
 					err:     err.Error() + " (Client.Timeout exceeded while awaiting headers)",
 					timeout: true,
 				}
@@ -950,7 +951,7 @@ func (c *Client) CloseIdleConnections() {
 }
 
 // cancelTimerBody is an io.ReadCloser that wraps rc with two features:
-// 1) on Read error or close, the stop func is called.
+// 1) On Read error or close, the stop func is called.
 // 2) On Read failure, if reqDidTimeout is true, the error is wrapped and
 //    marked as net.Error that hit its timeout.
 type cancelTimerBody struct {
diff --git a/src/net/http/cookie.go b/src/net/http/cookie.go
index 141bc947f6e..ca2c1c25066 100644
--- a/src/net/http/cookie.go
+++ b/src/net/http/cookie.go
@@ -7,6 +7,7 @@ package http
 import (
 	"log"
 	"net"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"strconv"
 	"strings"
@@ -93,15 +94,23 @@ func readSetCookies(h Header) []*Cookie {
 			if j := strings.Index(attr, "="); j >= 0 {
 				attr, val = attr[:j], attr[j+1:]
 			}
-			lowerAttr := strings.ToLower(attr)
+			lowerAttr, isASCII := ascii.ToLower(attr)
+			if !isASCII {
+				continue
+			}
 			val, ok = parseCookieValue(val, false)
 			if !ok {
 				c.Unparsed = append(c.Unparsed, parts[i])
 				continue
 			}
+
 			switch lowerAttr {
 			case "samesite":
-				lowerVal := strings.ToLower(val)
+				lowerVal, ascii := ascii.ToLower(val)
+				if !ascii {
+					c.SameSite = SameSiteDefaultMode
+					continue
+				}
 				switch lowerVal {
 				case "lax":
 					c.SameSite = SameSiteLaxMode
diff --git a/src/net/http/cookiejar/jar.go b/src/net/http/cookiejar/jar.go
index 9f199170847..e6583da7fe6 100644
--- a/src/net/http/cookiejar/jar.go
+++ b/src/net/http/cookiejar/jar.go
@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"net/http/internal/ascii"
 	"net/url"
 	"sort"
 	"strings"
@@ -296,7 +297,6 @@ func (j *Jar) setCookies(u *url.URL, cookies []*http.Cookie, now time.Time) {
 // host name.
 func canonicalHost(host string) (string, error) {
 	var err error
-	host = strings.ToLower(host)
 	if hasPort(host) {
 		host, _, err = net.SplitHostPort(host)
 		if err != nil {
@@ -307,7 +307,13 @@ func canonicalHost(host string) (string, error) {
 		// Strip trailing dot from fully qualified domain names.
 		host = host[:len(host)-1]
 	}
-	return toASCII(host)
+	encoded, err := toASCII(host)
+	if err != nil {
+		return "", err
+	}
+	// We know this is ascii, no need to check.
+	lower, _ := ascii.ToLower(encoded)
+	return lower, nil
 }
 
 // hasPort reports whether host contains a port number. host may be a host
@@ -469,7 +475,12 @@ func (j *Jar) domainAndType(host, domain string) (string, bool, error) {
 		// both are illegal.
 		return "", false, errMalformedDomain
 	}
-	domain = strings.ToLower(domain)
+
+	domain, isASCII := ascii.ToLower(domain)
+	if !isASCII {
+		// Received non-ASCII domain, e.g. "perché.com" instead of "xn--perch-fsa.com"
+		return "", false, errMalformedDomain
+	}
 
 	if domain[len(domain)-1] == '.' {
 		// We received stuff like "Domain=www.example.com.".
diff --git a/src/net/http/cookiejar/punycode.go b/src/net/http/cookiejar/punycode.go
index a9cc666e8c9..c7f438dd007 100644
--- a/src/net/http/cookiejar/punycode.go
+++ b/src/net/http/cookiejar/punycode.go
@@ -8,6 +8,7 @@ package cookiejar
 
 import (
 	"fmt"
+	"net/http/internal/ascii"
 	"strings"
 	"unicode/utf8"
 )
@@ -133,12 +134,12 @@ const acePrefix = "xn--"
 // toASCII("bücher.example.com") is "xn--bcher-kva.example.com", and
 // toASCII("golang") is "golang".
 func toASCII(s string) (string, error) {
-	if ascii(s) {
+	if ascii.Is(s) {
 		return s, nil
 	}
 	labels := strings.Split(s, ".")
 	for i, label := range labels {
-		if !ascii(label) {
+		if !ascii.Is(label) {
 			a, err := encode(acePrefix, label)
 			if err != nil {
 				return "", err
@@ -148,12 +149,3 @@ func toASCII(s string) (string, error) {
 	}
 	return strings.Join(labels, "."), nil
 }
-
-func ascii(s string) bool {
-	for i := 0; i < len(s); i++ {
-		if s[i] >= utf8.RuneSelf {
-			return false
-		}
-	}
-	return true
-}
diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index fd540ff255e..a948ff3eed4 100644
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -53,6 +53,48 @@ import (
 	"golang.org/x/net/idna"
 )
 
+// asciiEqualFold is strings.EqualFold, ASCII only. It reports whether s and t
+// are equal, ASCII-case-insensitively.
+func http2asciiEqualFold(s, t string) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i := 0; i < len(s); i++ {
+		if http2lower(s[i]) != http2lower(t[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// lower returns the ASCII lowercase version of b.
+func http2lower(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+// isASCIIPrint returns whether s is ASCII and printable according to
+// https://tools.ietf.org/html/rfc20#section-4.2.
+func http2isASCIIPrint(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < ' ' || s[i] > '~' {
+			return false
+		}
+	}
+	return true
+}
+
+// asciiToLower returns the lowercase version of s if s is ASCII and printable,
+// and whether or not it was.
+func http2asciiToLower(s string) (lower string, ok bool) {
+	if !http2isASCIIPrint(s) {
+		return "", false
+	}
+	return strings.ToLower(s), true
+}
+
 // A list of the possible cipher suite ids. Taken from
 // https://www.iana.org/assignments/tls-parameters/tls-parameters.txt
 
@@ -2907,6 +2949,20 @@ func http2traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textpr
 	return nil
 }
 
+// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
+// connection.
+func (t *http2Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	dialer := &tls.Dialer{
+		Config: cfg,
+	}
+	cn, err := dialer.DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, err
+	}
+	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
+	return tlsCn, nil
+}
+
 var http2DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1"
 
 type http2goroutineLock uint64
@@ -3128,12 +3184,12 @@ func http2buildCommonHeaderMaps() {
 	}
 }
 
-func http2lowerHeader(v string) string {
+func http2lowerHeader(v string) (lower string, ascii bool) {
 	http2buildCommonHeaderMapsOnce()
 	if s, ok := http2commonLowerHeader[v]; ok {
-		return s
+		return s, true
 	}
-	return strings.ToLower(v)
+	return http2asciiToLower(v)
 }
 
 var (
@@ -3831,13 +3887,12 @@ func http2ConfigureServer(s *Server, conf *http2Server) error {
 
 	if s.TLSConfig == nil {
 		s.TLSConfig = new(tls.Config)
-	} else if s.TLSConfig.CipherSuites != nil {
-		// If they already provided a CipherSuite list, return
-		// an error if it has a bad order or is missing
-		// ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
+	} else if s.TLSConfig.CipherSuites != nil && s.TLSConfig.MinVersion < tls.VersionTLS13 {
+		// If they already provided a TLS 1.0–1.2 CipherSuite list, return an
+		// error if it is missing ECDHE_RSA_WITH_AES_128_GCM_SHA256 or
+		// ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
 		haveRequired := false
-		sawBad := false
-		for i, cs := range s.TLSConfig.CipherSuites {
+		for _, cs := range s.TLSConfig.CipherSuites {
 			switch cs {
 			case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 				// Alternative MTI cipher to not discourage ECDSA-only servers.
@@ -3845,14 +3900,9 @@ func http2ConfigureServer(s *Server, conf *http2Server) error {
 				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
 				haveRequired = true
 			}
-			if http2isBadCipher(cs) {
-				sawBad = true
-			} else if sawBad {
-				return fmt.Errorf("http2: TLSConfig.CipherSuites index %d contains an HTTP/2-approved cipher suite (%#04x), but it comes after unapproved cipher suites. With this configuration, clients that don't support previous, approved cipher suites may be given an unapproved one and reject the connection.", i, cs)
-			}
 		}
 		if !haveRequired {
-			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).")
+			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)")
 		}
 	}
 
@@ -6394,8 +6444,12 @@ func (w *http2responseWriter) Push(target string, opts *PushOptions) error {
 		// but PUSH_PROMISE requests cannot have a body.
 		// http://tools.ietf.org/html/rfc7540#section-8.2
 		// Also disallow Host, since the promised URL must be absolute.
-		switch strings.ToLower(k) {
-		case "content-length", "content-encoding", "trailer", "te", "expect", "host":
+		if http2asciiEqualFold(k, "content-length") ||
+			http2asciiEqualFold(k, "content-encoding") ||
+			http2asciiEqualFold(k, "trailer") ||
+			http2asciiEqualFold(k, "te") ||
+			http2asciiEqualFold(k, "expect") ||
+			http2asciiEqualFold(k, "host") {
 			return fmt.Errorf("promised request headers cannot include %q", k)
 		}
 	}
@@ -7148,14 +7202,10 @@ func (t *http2Transport) dialTLS(ctx context.Context) func(string, string, *tls.
 		return t.DialTLS
 	}
 	return func(network, addr string, cfg *tls.Config) (net.Conn, error) {
-		dialer := &tls.Dialer{
-			Config: cfg,
-		}
-		cn, err := dialer.DialContext(ctx, network, addr)
+		tlsCn, err := t.dialTLSWithContext(ctx, network, addr, cfg)
 		if err != nil {
 			return nil, err
 		}
-		tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
 		state := tlsCn.ConnectionState()
 		if p := state.NegotiatedProtocol; p != http2NextProtoTLS {
 			return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, http2NextProtoTLS)
@@ -7163,7 +7213,7 @@ func (t *http2Transport) dialTLS(ctx context.Context) func(string, string, *tls.
 		if !state.NegotiatedProtocolIsMutual {
 			return nil, errors.New("http2: could not negotiate protocol mutually")
 		}
-		return cn, nil
+		return tlsCn, nil
 	}
 }
 
@@ -7552,7 +7602,7 @@ func http2checkConnHeaders(req *Request) error {
 	if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") {
 		return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv)
 	}
-	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !strings.EqualFold(vv[0], "close") && !strings.EqualFold(vv[0], "keep-alive")) {
+	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !http2asciiEqualFold(vv[0], "close") && !http2asciiEqualFold(vv[0], "keep-alive")) {
 		return fmt.Errorf("http2: invalid Connection request header: %q", vv)
 	}
 	return nil
@@ -8078,19 +8128,21 @@ func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trail
 
 		var didUA bool
 		for k, vv := range req.Header {
-			if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
+			if http2asciiEqualFold(k, "host") || http2asciiEqualFold(k, "content-length") {
 				// Host is :authority, already sent.
 				// Content-Length is automatic, set below.
 				continue
-			} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
-				strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
-				strings.EqualFold(k, "keep-alive") {
+			} else if http2asciiEqualFold(k, "connection") ||
+				http2asciiEqualFold(k, "proxy-connection") ||
+				http2asciiEqualFold(k, "transfer-encoding") ||
+				http2asciiEqualFold(k, "upgrade") ||
+				http2asciiEqualFold(k, "keep-alive") {
 				// Per 8.1.2.2 Connection-Specific Header
 				// Fields, don't send connection-specific
 				// fields. We have already checked if any
 				// are error-worthy so just ignore the rest.
 				continue
-			} else if strings.EqualFold(k, "user-agent") {
+			} else if http2asciiEqualFold(k, "user-agent") {
 				// Match Go's http1 behavior: at most one
 				// User-Agent. If set to nil or empty string,
 				// then omit it. Otherwise if not mentioned,
@@ -8103,7 +8155,7 @@ func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trail
 				if vv[0] == "" {
 					continue
 				}
-			} else if strings.EqualFold(k, "cookie") {
+			} else if http2asciiEqualFold(k, "cookie") {
 				// Per 8.1.2.5 To allow for better compression efficiency, the
 				// Cookie header field MAY be split into separate header fields,
 				// each with one or more cookie-pairs.
@@ -8162,7 +8214,12 @@ func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trail
 
 	// Header list size is ok. Write the headers.
 	enumerateHeaders(func(name, value string) {
-		name = strings.ToLower(name)
+		name, ascii := http2asciiToLower(name)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			return
+		}
 		cc.writeHeader(name, value)
 		if traceHeaders {
 			http2traceWroteHeaderField(trace, name, value)
@@ -8210,9 +8267,14 @@ func (cc *http2ClientConn) encodeTrailers(req *Request) ([]byte, error) {
 	}
 
 	for k, vv := range req.Trailer {
+		lowKey, ascii := http2asciiToLower(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		// Transfer-Encoding, etc.. have already been filtered at the
 		// start of RoundTrip
-		lowKey := strings.ToLower(k)
 		for _, v := range vv {
 			cc.writeHeader(lowKey, v)
 		}
@@ -9635,7 +9697,12 @@ func http2encodeHeaders(enc *hpack.Encoder, h Header, keys []string) {
 	}
 	for _, k := range keys {
 		vv := h[k]
-		k = http2lowerHeader(k)
+		k, ascii := http2lowerHeader(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		if !http2validWireHeaderFieldName(k) {
 			// Skip it as backup paranoia. Per
 			// golang.org/issue/14048, these should
diff --git a/src/net/http/header.go b/src/net/http/header.go
index b9b53911f38..4c72dcb2c88 100644
--- a/src/net/http/header.go
+++ b/src/net/http/header.go
@@ -7,6 +7,7 @@ package http
 import (
 	"io"
 	"net/http/httptrace"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"sort"
 	"strings"
@@ -251,7 +252,7 @@ func hasToken(v, token string) bool {
 		if endPos := sp + len(token); endPos != len(v) && !isTokenBoundary(v[endPos]) {
 			continue
 		}
-		if strings.EqualFold(v[sp:sp+len(token)], token) {
+		if ascii.EqualFold(v[sp:sp+len(token)], token) {
 			return true
 		}
 	}
diff --git a/src/net/http/http.go b/src/net/http/http.go
index 4c5054b3994..101799f574f 100644
--- a/src/net/http/http.go
+++ b/src/net/http/http.go
@@ -62,15 +62,6 @@ func isNotToken(r rune) bool {
 	return !httpguts.IsTokenRune(r)
 }
 
-func isASCII(s string) bool {
-	for i := 0; i < len(s); i++ {
-		if s[i] >= utf8.RuneSelf {
-			return false
-		}
-	}
-	return true
-}
-
 // stringContainsCTLByte reports whether s contains any ASCII control character.
 func stringContainsCTLByte(s string) bool {
 	for i := 0; i < len(s); i++ {
diff --git a/src/net/http/http_test.go b/src/net/http/http_test.go
index 3f1d7cee710..0d92fe5f964 100644
--- a/src/net/http/http_test.go
+++ b/src/net/http/http_test.go
@@ -9,9 +9,13 @@ package http
 import (
 	"bytes"
 	"internal/testenv"
+	"io/fs"
 	"net/url"
+	"os"
 	"os/exec"
 	"reflect"
+	"regexp"
+	"strings"
 	"testing"
 )
 
@@ -156,3 +160,61 @@ func BenchmarkCopyValues(b *testing.B) {
 		b.Fatal("Benchmark wasn't run")
 	}
 }
+
+var forbiddenStringsFunctions = map[string]bool{
+	// Functions that use Unicode-aware case folding.
+	"EqualFold":      true,
+	"Title":          true,
+	"ToLower":        true,
+	"ToLowerSpecial": true,
+	"ToTitle":        true,
+	"ToTitleSpecial": true,
+	"ToUpper":        true,
+	"ToUpperSpecial": true,
+
+	// Functions that use Unicode-aware spaces.
+	"Fields":    true,
+	"TrimSpace": true,
+}
+
+// TestNoUnicodeStrings checks that nothing in net/http uses the Unicode-aware
+// strings and bytes package functions. HTTP is mostly ASCII based, and doing
+// Unicode-aware case folding or space stripping can introduce vulnerabilities.
+func TestNoUnicodeStrings(t *testing.T) {
+	if !testenv.HasSrc() {
+		t.Skip("source code not available")
+	}
+
+	re := regexp.MustCompile(`(strings|bytes).([A-Za-z]+)`)
+	if err := fs.WalkDir(os.DirFS("."), ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if path == "internal/ascii" {
+			return fs.SkipDir
+		}
+		if !strings.HasSuffix(path, ".go") ||
+			strings.HasSuffix(path, "_test.go") ||
+			path == "h2_bundle.go" || d.IsDir() {
+			return nil
+		}
+
+		contents, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for lineNum, line := range strings.Split(string(contents), "\n") {
+			for _, match := range re.FindAllStringSubmatch(line, -1) {
+				if !forbiddenStringsFunctions[match[2]] {
+					continue
+				}
+				t.Errorf("disallowed call to %s at %s:%d", match[0], path, lineNum+1)
+			}
+		}
+
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/src/net/http/httptest/server.go b/src/net/http/httptest/server.go
index a02a6d64c39..4f85ff55d89 100644
--- a/src/net/http/httptest/server.go
+++ b/src/net/http/httptest/server.go
@@ -14,7 +14,7 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"os"
 	"strings"
 	"sync"
@@ -144,7 +144,7 @@ func (s *Server) StartTLS() {
 	if s.client == nil {
 		s.client = &http.Client{Transport: &http.Transport{}}
 	}
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		panic(fmt.Sprintf("httptest: NewTLSServer: %v", err))
 	}
diff --git a/src/net/http/httputil/reverseproxy.go b/src/net/http/httputil/reverseproxy.go
index db42ac6ba55..8b63368386f 100644
--- a/src/net/http/httputil/reverseproxy.go
+++ b/src/net/http/httputil/reverseproxy.go
@@ -13,6 +13,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"net/url"
 	"strings"
@@ -234,6 +235,15 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	if req.ContentLength == 0 {
 		outreq.Body = nil // Issue 16036: nil Body for http.Transport retries
 	}
+	if outreq.Body != nil {
+		// Reading from the request body after returning from a handler is not
+		// allowed, and the RoundTrip goroutine that reads the Body can outlive
+		// this handler. This can lead to a crash if the handler panics (see
+		// Issue 46866). Although calling Close doesn't guarantee there isn't
+		// any Read in flight after the handle returns, in practice it's safe to
+		// read after closing it.
+		defer outreq.Body.Close()
+	}
 	if outreq.Header == nil {
 		outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate
 	}
@@ -242,28 +252,28 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	outreq.Close = false
 
 	reqUpType := upgradeType(outreq.Header)
+	if !ascii.IsPrint(reqUpType) {
+		p.getErrorHandler()(rw, req, fmt.Errorf("client tried to switch to invalid protocol %q", reqUpType))
+		return
+	}
 	removeConnectionHeaders(outreq.Header)
 
 	// Remove hop-by-hop headers to the backend. Especially
 	// important is "Connection" because we want a persistent
 	// connection, regardless of what the client sent to us.
 	for _, h := range hopHeaders {
-		hv := outreq.Header.Get(h)
-		if hv == "" {
-			continue
-		}
-		if h == "Te" && hv == "trailers" {
-			// Issue 21096: tell backend applications that
-			// care about trailer support that we support
-			// trailers. (We do, but we don't go out of
-			// our way to advertise that unless the
-			// incoming client request thought it was
-			// worth mentioning)
-			continue
-		}
 		outreq.Header.Del(h)
 	}
 
+	// Issue 21096: tell backend applications that care about trailer support
+	// that we support trailers. (We do, but we don't go out of our way to
+	// advertise that unless the incoming client request thought it was worth
+	// mentioning.) Note that we look at req.Header, not outreq.Header, since
+	// the latter has passed through removeConnectionHeaders.
+	if httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") {
+		outreq.Header.Set("Te", "trailers")
+	}
+
 	// After stripping all the hop-by-hop connection headers above, add back any
 	// necessary for protocol upgrades, such as for websockets.
 	if reqUpType != "" {
@@ -538,13 +548,16 @@ func upgradeType(h http.Header) string {
 	if !httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade") {
 		return ""
 	}
-	return strings.ToLower(h.Get("Upgrade"))
+	return h.Get("Upgrade")
 }
 
 func (p *ReverseProxy) handleUpgradeResponse(rw http.ResponseWriter, req *http.Request, res *http.Response) {
 	reqUpType := upgradeType(req.Header)
 	resUpType := upgradeType(res.Header)
-	if reqUpType != resUpType {
+	if !ascii.IsPrint(resUpType) { // We know reqUpType is ASCII, it's checked by the caller.
+		p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch to invalid protocol %q", resUpType))
+	}
+	if !ascii.EqualFold(reqUpType, resUpType) {
 		p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch protocol %q when %q was requested", resUpType, reqUpType))
 		return
 	}
diff --git a/src/net/http/httputil/reverseproxy_test.go b/src/net/http/httputil/reverseproxy_test.go
index 3acbd940e4b..4b6ad77a294 100644
--- a/src/net/http/httputil/reverseproxy_test.go
+++ b/src/net/http/httputil/reverseproxy_test.go
@@ -16,6 +16,7 @@ import (
 	"log"
 	"net/http"
 	"net/http/httptest"
+	"net/http/internal/ascii"
 	"net/url"
 	"os"
 	"reflect"
@@ -90,8 +91,9 @@ func TestReverseProxy(t *testing.T) {
 
 	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
 	getReq.Host = "some-name"
-	getReq.Header.Set("Connection", "close")
-	getReq.Header.Set("Te", "trailers")
+	getReq.Header.Set("Connection", "close, TE")
+	getReq.Header.Add("Te", "foo")
+	getReq.Header.Add("Te", "bar, trailers")
 	getReq.Header.Set("Proxy-Connection", "should be deleted")
 	getReq.Header.Set("Upgrade", "foo")
 	getReq.Close = true
@@ -235,6 +237,64 @@ func TestReverseProxyStripHeadersPresentInConnection(t *testing.T) {
 	}
 }
 
+func TestReverseProxyStripEmptyConnection(t *testing.T) {
+	// See Issue 46313.
+	const backendResponse = "I am the backend"
+
+	// someConnHeader is some arbitrary header to be declared as a hop-by-hop header
+	// in the Request's Connection header.
+	const someConnHeader = "X-Some-Conn-Header"
+
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if c := r.Header.Values("Connection"); len(c) != 0 {
+			t.Errorf("handler got header %q = %v; want empty", "Connection", c)
+		}
+		if c := r.Header.Get(someConnHeader); c != "" {
+			t.Errorf("handler got header %q = %q; want empty", someConnHeader, c)
+		}
+		w.Header().Add("Connection", "")
+		w.Header().Add("Connection", someConnHeader)
+		w.Header().Set(someConnHeader, "should be deleted")
+		io.WriteString(w, backendResponse)
+	}))
+	defer backend.Close()
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	frontend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		proxyHandler.ServeHTTP(w, r)
+		if c := r.Header.Get(someConnHeader); c != "should be deleted" {
+			t.Errorf("handler modified header %q = %q; want %q", someConnHeader, c, "should be deleted")
+		}
+	}))
+	defer frontend.Close()
+
+	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
+	getReq.Header.Add("Connection", "")
+	getReq.Header.Add("Connection", someConnHeader)
+	getReq.Header.Set(someConnHeader, "should be deleted")
+	res, err := frontend.Client().Do(getReq)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	defer res.Body.Close()
+	bodyBytes, err := io.ReadAll(res.Body)
+	if err != nil {
+		t.Fatalf("reading body: %v", err)
+	}
+	if got, want := string(bodyBytes), backendResponse; got != want {
+		t.Errorf("got body %q; want %q", got, want)
+	}
+	if c := res.Header.Get("Connection"); c != "" {
+		t.Errorf("handler got header %q = %q; want empty", "Connection", c)
+	}
+	if c := res.Header.Get(someConnHeader); c != "" {
+		t.Errorf("handler got header %q = %q; want empty", someConnHeader, c)
+	}
+}
+
 func TestXForwardedFor(t *testing.T) {
 	const prevForwardedFor = "client ip"
 	const backendResponse = "I am the backend"
@@ -1062,6 +1122,45 @@ func TestReverseProxy_PanicBodyError(t *testing.T) {
 	rproxy.ServeHTTP(httptest.NewRecorder(), req)
 }
 
+// Issue #46866: panic without closing incoming request body causes a panic
+func TestReverseProxy_PanicClosesIncomingBody(t *testing.T) {
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		out := "this call was relayed by the reverse proxy"
+		// Coerce a wrong content length to induce io.ErrUnexpectedEOF
+		w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out)*2))
+		fmt.Fprintln(w, out)
+	}))
+	defer backend.Close()
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+	frontendClient := frontend.Client()
+
+	var wg sync.WaitGroup
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for j := 0; j < 10; j++ {
+				const reqLen = 6 * 1024 * 1024
+				req, _ := http.NewRequest("POST", frontend.URL, &io.LimitedReader{R: neverEnding('x'), N: reqLen})
+				req.ContentLength = reqLen
+				resp, _ := frontendClient.Transport.RoundTrip(req)
+				if resp != nil {
+					io.Copy(io.Discard, resp.Body)
+					resp.Body.Close()
+				}
+			}
+		}()
+	}
+	wg.Wait()
+}
+
 func TestSelectFlushInterval(t *testing.T) {
 	tests := []struct {
 		name string
@@ -1183,7 +1282,7 @@ func TestReverseProxyWebSocket(t *testing.T) {
 		t.Errorf("Header(XHeader) = %q; want %q", got, want)
 	}
 
-	if upgradeType(res.Header) != "websocket" {
+	if !ascii.EqualFold(upgradeType(res.Header), "websocket") {
 		t.Fatalf("not websocket upgrade; got %#v", res.Header)
 	}
 	rwc, ok := res.Body.(io.ReadWriteCloser)
@@ -1208,7 +1307,7 @@ func TestReverseProxyWebSocket(t *testing.T) {
 	}
 }
 
-func TestReverseProxyWebSocketCancelation(t *testing.T) {
+func TestReverseProxyWebSocketCancellation(t *testing.T) {
 	n := 5
 	triggerCancelCh := make(chan bool, n)
 	nthResponse := func(i int) string {
@@ -1300,7 +1399,7 @@ func TestReverseProxyWebSocketCancelation(t *testing.T) {
 		t.Errorf("X-Header mismatch\n\tgot:  %q\n\twant: %q", g, w)
 	}
 
-	if g, w := upgradeType(res.Header), "websocket"; g != w {
+	if g, w := upgradeType(res.Header), "websocket"; !ascii.EqualFold(g, w) {
 		t.Fatalf("Upgrade header mismatch\n\tgot:  %q\n\twant: %q", g, w)
 	}
 
diff --git a/src/net/http/internal/ascii/print.go b/src/net/http/internal/ascii/print.go
new file mode 100644
index 00000000000..585e5baba40
--- /dev/null
+++ b/src/net/http/internal/ascii/print.go
@@ -0,0 +1,61 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ascii
+
+import (
+	"strings"
+	"unicode"
+)
+
+// EqualFold is strings.EqualFold, ASCII only. It reports whether s and t
+// are equal, ASCII-case-insensitively.
+func EqualFold(s, t string) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i := 0; i < len(s); i++ {
+		if lower(s[i]) != lower(t[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// lower returns the ASCII lowercase version of b.
+func lower(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+// IsPrint returns whether s is ASCII and printable according to
+// https://tools.ietf.org/html/rfc20#section-4.2.
+func IsPrint(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < ' ' || s[i] > '~' {
+			return false
+		}
+	}
+	return true
+}
+
+// Is returns whether s is ASCII.
+func Is(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] > unicode.MaxASCII {
+			return false
+		}
+	}
+	return true
+}
+
+// ToLower returns the lowercase version of s if s is ASCII and printable.
+func ToLower(s string) (lower string, ok bool) {
+	if !IsPrint(s) {
+		return "", false
+	}
+	return strings.ToLower(s), true
+}
diff --git a/src/net/http/internal/ascii/print_test.go b/src/net/http/internal/ascii/print_test.go
new file mode 100644
index 00000000000..0b7767ca331
--- /dev/null
+++ b/src/net/http/internal/ascii/print_test.go
@@ -0,0 +1,95 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ascii
+
+import "testing"
+
+func TestEqualFold(t *testing.T) {
+	var tests = []struct {
+		name string
+		a, b string
+		want bool
+	}{
+		{
+			name: "empty",
+			want: true,
+		},
+		{
+			name: "simple match",
+			a:    "CHUNKED",
+			b:    "chunked",
+			want: true,
+		},
+		{
+			name: "same string",
+			a:    "chunked",
+			b:    "chunked",
+			want: true,
+		},
+		{
+			name: "Unicode Kelvin symbol",
+			a:    "chunKed", // This "K" is 'KELVIN SIGN' (\u212A)
+			b:    "chunked",
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := EqualFold(tt.a, tt.b); got != tt.want {
+				t.Errorf("AsciiEqualFold(%q,%q): got %v want %v", tt.a, tt.b, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestIsPrint(t *testing.T) {
+	var tests = []struct {
+		name string
+		in   string
+		want bool
+	}{
+		{
+			name: "empty",
+			want: true,
+		},
+		{
+			name: "ASCII low",
+			in:   "This is a space: ' '",
+			want: true,
+		},
+		{
+			name: "ASCII high",
+			in:   "This is a tilde: '~'",
+			want: true,
+		},
+		{
+			name: "ASCII low non-print",
+			in:   "This is a unit separator: \x1F",
+			want: false,
+		},
+		{
+			name: "Ascii high non-print",
+			in:   "This is a Delete: \x7F",
+			want: false,
+		},
+		{
+			name: "Unicode letter",
+			in:   "Today it's 280K outside: it's freezing!", // This "K" is 'KELVIN SIGN' (\u212A)
+			want: false,
+		},
+		{
+			name: "Unicode emoji",
+			in:   "Gophers like 🧀",
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := IsPrint(tt.in); got != tt.want {
+				t.Errorf("IsASCIIPrint(%q): got %v want %v", tt.in, got, tt.want)
+			}
+		})
+	}
+}
diff --git a/src/net/http/internal/testcert.go b/src/net/http/internal/testcert/testcert.go
similarity index 94%
rename from src/net/http/internal/testcert.go
rename to src/net/http/internal/testcert/testcert.go
index 2284a836fb7..5f94704ef59 100644
--- a/src/net/http/internal/testcert.go
+++ b/src/net/http/internal/testcert/testcert.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package internal
+// Package testcert contains a test-only localhost certificate.
+package testcert
 
 import "strings"
 
@@ -25,7 +26,7 @@ h1fIw3cSS2OolhloGw/XM6RWPWtPAlGykKLciQrBru5NAPvCMsb/I1DAceTiotQM
 fblo6RBxUQ==
 -----END CERTIFICATE-----`)
 
-// LocalhostKey is the private key for localhostCert.
+// LocalhostKey is the private key for LocalhostCert.
 var LocalhostKey = []byte(testingKey(`-----BEGIN RSA TESTING KEY-----
 MIICXgIBAAKBgQDuLnQAI3mDgey3VBzWnB2L39JUU4txjeVE6myuDqkM/uGlfjb9
 SjY1bIw4iA5sBBZzHi3z0h1YV8QPuxEbi4nW91IJm2gsvvZhIrCHS3l6afab4pZB
diff --git a/src/net/http/request.go b/src/net/http/request.go
index 4a07eb1c798..09cb0c7f564 100644
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -19,6 +19,7 @@ import (
 	"mime/multipart"
 	"net"
 	"net/http/httptrace"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"net/url"
 	urlpkg "net/url"
@@ -723,7 +724,7 @@ func idnaASCII(v string) (string, error) {
 	// version does not.
 	// Note that for correct ASCII IDNs ToASCII will only do considerably more
 	// work, but it will not cause an allocation.
-	if isASCII(v) {
+	if ascii.Is(v) {
 		return v, nil
 	}
 	return idna.Lookup.ToASCII(v)
@@ -948,7 +949,7 @@ func (r *Request) BasicAuth() (username, password string, ok bool) {
 func parseBasicAuth(auth string) (username, password string, ok bool) {
 	const prefix = "Basic "
 	// Case insensitive prefix match. See Issue 22736.
-	if len(auth) < len(prefix) || !strings.EqualFold(auth[:len(prefix)], prefix) {
+	if len(auth) < len(prefix) || !ascii.EqualFold(auth[:len(prefix)], prefix) {
 		return
 	}
 	c, err := base64.StdEncoding.DecodeString(auth[len(prefix):])
@@ -1292,16 +1293,18 @@ func (r *Request) ParseForm() error {
 // its file parts are stored in memory, with the remainder stored on
 // disk in temporary files.
 // ParseMultipartForm calls ParseForm if necessary.
+// If ParseForm returns an error, ParseMultipartForm returns it but also
+// continues parsing the request body.
 // After one call to ParseMultipartForm, subsequent calls have no effect.
 func (r *Request) ParseMultipartForm(maxMemory int64) error {
 	if r.MultipartForm == multipartByReader {
 		return errors.New("http: multipart handled by MultipartReader")
 	}
+	var parseFormErr error
 	if r.Form == nil {
-		err := r.ParseForm()
-		if err != nil {
-			return err
-		}
+		// Let errors in ParseForm fall through, and just
+		// return it at the end.
+		parseFormErr = r.ParseForm()
 	}
 	if r.MultipartForm != nil {
 		return nil
@@ -1328,7 +1331,7 @@ func (r *Request) ParseMultipartForm(maxMemory int64) error {
 
 	r.MultipartForm = f
 
-	return nil
+	return parseFormErr
 }
 
 // FormValue returns the first value for the named component of the query.
@@ -1456,5 +1459,5 @@ func requestMethodUsuallyLacksBody(method string) bool {
 // an HTTP/1 connection.
 func (r *Request) requiresHTTP1() bool {
 	return hasToken(r.Header.Get("Connection"), "upgrade") &&
-		strings.EqualFold(r.Header.Get("Upgrade"), "websocket")
+		ascii.EqualFold(r.Header.Get("Upgrade"), "websocket")
 }
diff --git a/src/net/http/request_test.go b/src/net/http/request_test.go
index 952828b395e..4e0c4ba207f 100644
--- a/src/net/http/request_test.go
+++ b/src/net/http/request_test.go
@@ -32,9 +32,26 @@ func TestQuery(t *testing.T) {
 	}
 }
 
+// Issue #25192: Test that ParseForm fails but still parses the form when an URL
+// containing a semicolon is provided.
+func TestParseFormSemicolonSeparator(t *testing.T) {
+	for _, method := range []string{"POST", "PATCH", "PUT", "GET"} {
+		req, _ := NewRequest(method, "http://www.google.com/search?q=foo;q=bar&a=1",
+			strings.NewReader("q"))
+		err := req.ParseForm()
+		if err == nil {
+			t.Fatalf(`for method %s, ParseForm expected an error, got success`, method)
+		}
+		wantForm := url.Values{"a": []string{"1"}}
+		if !reflect.DeepEqual(req.Form, wantForm) {
+			t.Fatalf("for method %s, ParseForm expected req.Form = %v, want %v", method, req.Form, wantForm)
+		}
+	}
+}
+
 func TestParseFormQuery(t *testing.T) {
 	req, _ := NewRequest("POST", "http://www.google.com/search?q=foo&q=bar&both=x&prio=1&orphan=nope&empty=not",
-		strings.NewReader("z=post&both=y&prio=2&=nokey&orphan;empty=&"))
+		strings.NewReader("z=post&both=y&prio=2&=nokey&orphan&empty=&"))
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded; param=value")
 
 	if q := req.FormValue("q"); q != "foo" {
@@ -365,6 +382,18 @@ func TestMultipartRequest(t *testing.T) {
 	validateTestMultipartContents(t, req, false)
 }
 
+// Issue #25192: Test that ParseMultipartForm fails but still parses the
+// multi-part form when an URL containing a semicolon is provided.
+func TestParseMultipartFormSemicolonSeparator(t *testing.T) {
+	req := newTestMultipartRequest(t)
+	req.URL = &url.URL{RawQuery: "q=foo;q=bar"}
+	if err := req.ParseMultipartForm(25); err == nil {
+		t.Fatal("ParseMultipartForm expected error due to invalid semicolon, got nil")
+	}
+	defer req.MultipartForm.RemoveAll()
+	validateTestMultipartContents(t, req, false)
+}
+
 func TestMultipartRequestAuto(t *testing.T) {
 	// Test that FormValue and FormFile automatically invoke
 	// ParseMultipartForm and return the right values.
diff --git a/src/net/http/serve_test.go b/src/net/http/serve_test.go
index a9714682c7e..6394da3bb7c 100644
--- a/src/net/http/serve_test.go
+++ b/src/net/http/serve_test.go
@@ -25,6 +25,7 @@ import (
 	"net/http/httptest"
 	"net/http/httputil"
 	"net/http/internal"
+	"net/http/internal/testcert"
 	"net/url"
 	"os"
 	"os/exec"
@@ -1475,7 +1476,7 @@ func TestServeTLS(t *testing.T) {
 	defer afterTest(t)
 	defer SetTestHookServerServe(nil)
 
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1599,7 +1600,7 @@ func TestAutomaticHTTP2_Serve_WithTLSConfig(t *testing.T) {
 }
 
 func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1609,7 +1610,7 @@ func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
 }
 
 func TestAutomaticHTTP2_ListenAndServe_GetCertificate(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -6524,3 +6525,87 @@ func TestMuxRedirectRelative(t *testing.T) {
 		t.Errorf("Expected response code %d; got %d", want, got)
 	}
 }
+
+// TestQuerySemicolon tests the behavior of semicolons in queries. See Issue 25192.
+func TestQuerySemicolon(t *testing.T) {
+	t.Cleanup(func() { afterTest(t) })
+
+	tests := []struct {
+		query           string
+		xNoSemicolons   string
+		xWithSemicolons string
+		warning         bool
+	}{
+		{"?a=1;x=bad&x=good", "good", "bad", true},
+		{"?a=1;b=bad&x=good", "good", "good", true},
+		{"?a=1%3Bx=bad&x=good%3B", "good;", "good;", false},
+		{"?a=1;x=good;x=bad", "", "good", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.query+"/allow=false", func(t *testing.T) {
+			allowSemicolons := false
+			testQuerySemicolon(t, tt.query, tt.xNoSemicolons, allowSemicolons, tt.warning)
+		})
+		t.Run(tt.query+"/allow=true", func(t *testing.T) {
+			allowSemicolons, expectWarning := true, false
+			testQuerySemicolon(t, tt.query, tt.xWithSemicolons, allowSemicolons, expectWarning)
+		})
+	}
+}
+
+func testQuerySemicolon(t *testing.T, query string, wantX string, allowSemicolons, expectWarning bool) {
+	setParallel(t)
+
+	writeBackX := func(w ResponseWriter, r *Request) {
+		x := r.URL.Query().Get("x")
+		if expectWarning {
+			if err := r.ParseForm(); err == nil || !strings.Contains(err.Error(), "semicolon") {
+				t.Errorf("expected error mentioning semicolons from ParseForm, got %v", err)
+			}
+		} else {
+			if err := r.ParseForm(); err != nil {
+				t.Errorf("expected no error from ParseForm, got %v", err)
+			}
+		}
+		if got := r.FormValue("x"); x != got {
+			t.Errorf("got %q from FormValue, want %q", got, x)
+		}
+		fmt.Fprintf(w, "%s", x)
+	}
+
+	h := Handler(HandlerFunc(writeBackX))
+	if allowSemicolons {
+		h = AllowQuerySemicolons(h)
+	}
+
+	ts := httptest.NewUnstartedServer(h)
+	logBuf := &bytes.Buffer{}
+	ts.Config.ErrorLog = log.New(logBuf, "", 0)
+	ts.Start()
+	defer ts.Close()
+
+	req, _ := NewRequest("GET", ts.URL+query, nil)
+	res, err := ts.Client().Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	slurp, _ := io.ReadAll(res.Body)
+	res.Body.Close()
+	if got, want := res.StatusCode, 200; got != want {
+		t.Errorf("Status = %d; want = %d", got, want)
+	}
+	if got, want := string(slurp), wantX; got != want {
+		t.Errorf("Body = %q; want = %q", got, want)
+	}
+
+	if expectWarning {
+		if !strings.Contains(logBuf.String(), "semicolon") {
+			t.Errorf("got %q from ErrorLog, expected a mention of semicolons", logBuf.String())
+		}
+	} else {
+		if strings.Contains(logBuf.String(), "semicolon") {
+			t.Errorf("got %q from ErrorLog, expected no mention of semicolons", logBuf.String())
+		}
+	}
+}
diff --git a/src/net/http/server.go b/src/net/http/server.go
index 4e73508973a..5b113cff970 100644
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -333,7 +333,7 @@ func (c *conn) hijackLocked() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
 const bufferBeforeChunkingSize = 2048
 
 // chunkWriter writes to a response's conn buffer, and is the writer
-// wrapped by the response.bufw buffered writer.
+// wrapped by the response.w buffered writer.
 //
 // chunkWriter also is responsible for finalizing the Header, including
 // conditionally setting the Content-Type and setting a Content-Length
@@ -577,37 +577,17 @@ func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
 		return io.CopyBuffer(writerOnly{w}, src, buf)
 	}
 
-	// sendfile path:
-
-	// Do not start actually writing response until src is readable.
-	// If body length is <= sniffLen, sendfile/splice path will do
-	// little anyway. This small read also satisfies sniffing the
-	// body in case Content-Type is missing.
-	nr, er := src.Read(buf[:sniffLen])
-	atEOF := errors.Is(er, io.EOF)
-	n += int64(nr)
-
-	if nr > 0 {
-		// Write the small amount read normally.
-		nw, ew := w.Write(buf[:nr])
-		if ew != nil {
-			err = ew
-		} else if nr != nw {
-			err = io.ErrShortWrite
+	// Copy the first sniffLen bytes before switching to ReadFrom.
+	// This ensures we don't start writing the response before the
+	// source is available (see golang.org/issue/5660) and provides
+	// enough bytes to perform Content-Type sniffing when required.
+	if !w.cw.wroteHeader {
+		n0, err := io.CopyBuffer(writerOnly{w}, io.LimitReader(src, sniffLen), buf)
+		n += n0
+		if err != nil || n0 < sniffLen {
+			return n, err
 		}
 	}
-	if err == nil && er != nil && !atEOF {
-		err = er
-	}
-
-	// Do not send StatusOK in the error case where nothing has been written.
-	if err == nil && !w.wroteHeader {
-		w.WriteHeader(StatusOK) // nr == 0, no error (or EOF)
-	}
-
-	if err != nil || atEOF {
-		return n, err
-	}
 
 	w.w.Flush()  // get rid of any previous writes
 	w.cw.flush() // make sure Header is written; flush data to rwc
@@ -620,7 +600,7 @@ func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
 		return n, err
 	}
 
-	n0, err := io.Copy(writerOnly{w}, src)
+	n0, err := io.CopyBuffer(writerOnly{w}, src, buf)
 	n += n0
 	return n, err
 }
@@ -1549,12 +1529,12 @@ func (w *response) bodyAllowed() bool {
 // The Writers are wired together like:
 //
 // 1. *response (the ResponseWriter) ->
-// 2. (*response).w, a *bufio.Writer of bufferBeforeChunkingSize bytes
+// 2. (*response).w, a *bufio.Writer of bufferBeforeChunkingSize bytes ->
 // 3. chunkWriter.Writer (whose writeHeader finalizes Content-Length/Type)
-//    and which writes the chunk headers, if needed.
-// 4. conn.buf, a bufio.Writer of default (4kB) bytes, writing to ->
+//    and which writes the chunk headers, if needed ->
+// 4. conn.bufw, a *bufio.Writer of default (4kB) bytes, writing to ->
 // 5. checkConnErrorWriter{c}, which notes any non-nil error on Write
-//    and populates c.werr with it if so. but otherwise writes to:
+//    and populates c.werr with it if so, but otherwise writes to ->
 // 6. the rwc, the net.Conn.
 //
 // TODO(bradfitz): short-circuit some of the buffering when the
@@ -2882,9 +2862,51 @@ func (sh serverHandler) ServeHTTP(rw ResponseWriter, req *Request) {
 	if req.RequestURI == "*" && req.Method == "OPTIONS" {
 		handler = globalOptionsHandler{}
 	}
+
+	if req.URL != nil && strings.Contains(req.URL.RawQuery, ";") {
+		var allowQuerySemicolonsInUse int32
+		req = req.WithContext(context.WithValue(req.Context(), silenceSemWarnContextKey, func() {
+			atomic.StoreInt32(&allowQuerySemicolonsInUse, 1)
+		}))
+		defer func() {
+			if atomic.LoadInt32(&allowQuerySemicolonsInUse) == 0 {
+				sh.srv.logf("http: URL query contains semicolon, which is no longer a supported separator; parts of the query may be stripped when parsed; see golang.org/issue/25192")
+			}
+		}()
+	}
+
 	handler.ServeHTTP(rw, req)
 }
 
+var silenceSemWarnContextKey = &contextKey{"silence-semicolons"}
+
+// AllowQuerySemicolons returns a handler that serves requests by converting any
+// unescaped semicolons in the URL query to ampersands, and invoking the handler h.
+//
+// This restores the pre-Go 1.17 behavior of splitting query parameters on both
+// semicolons and ampersands. (See golang.org/issue/25192). Note that this
+// behavior doesn't match that of many proxies, and the mismatch can lead to
+// security issues.
+//
+// AllowQuerySemicolons should be invoked before Request.ParseForm is called.
+func AllowQuerySemicolons(h Handler) Handler {
+	return HandlerFunc(func(w ResponseWriter, r *Request) {
+		if silenceSemicolonsWarning, ok := r.Context().Value(silenceSemWarnContextKey).(func()); ok {
+			silenceSemicolonsWarning()
+		}
+		if strings.Contains(r.URL.RawQuery, ";") {
+			r2 := new(Request)
+			*r2 = *r
+			r2.URL = new(url.URL)
+			*r2.URL = *r.URL
+			r2.URL.RawQuery = strings.ReplaceAll(r.URL.RawQuery, ";", "&")
+			h.ServeHTTP(w, r2)
+		} else {
+			h.ServeHTTP(w, r)
+		}
+	})
+}
+
 // ListenAndServe listens on the TCP network address srv.Addr and then
 // calls Serve to handle requests on incoming connections.
 // Accepted connections are configured to enable TCP keep-alives.
diff --git a/src/net/http/sniff_test.go b/src/net/http/sniff_test.go
index 8d5350374dd..e91335729af 100644
--- a/src/net/http/sniff_test.go
+++ b/src/net/http/sniff_test.go
@@ -157,9 +157,25 @@ func testServerIssue5953(t *testing.T, h2 bool) {
 	resp.Body.Close()
 }
 
-func TestContentTypeWithCopy_h1(t *testing.T) { testContentTypeWithCopy(t, h1Mode) }
-func TestContentTypeWithCopy_h2(t *testing.T) { testContentTypeWithCopy(t, h2Mode) }
-func testContentTypeWithCopy(t *testing.T, h2 bool) {
+type byteAtATimeReader struct {
+	buf []byte
+}
+
+func (b *byteAtATimeReader) Read(p []byte) (n int, err error) {
+	if len(p) < 1 {
+		return 0, nil
+	}
+	if len(b.buf) == 0 {
+		return 0, io.EOF
+	}
+	p[0] = b.buf[0]
+	b.buf = b.buf[1:]
+	return 1, nil
+}
+
+func TestContentTypeWithVariousSources_h1(t *testing.T) { testContentTypeWithVariousSources(t, h1Mode) }
+func TestContentTypeWithVariousSources_h2(t *testing.T) { testContentTypeWithVariousSources(t, h2Mode) }
+func testContentTypeWithVariousSources(t *testing.T, h2 bool) {
 	defer afterTest(t)
 
 	const (
@@ -167,30 +183,86 @@ func testContentTypeWithCopy(t *testing.T, h2 bool) {
 		expected = "text/html; charset=utf-8"
 	)
 
-	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
-		// Use io.Copy from a bytes.Buffer to trigger ReadFrom.
-		buf := bytes.NewBuffer([]byte(input))
-		n, err := io.Copy(w, buf)
-		if int(n) != len(input) || err != nil {
-			t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
-		}
-	}))
-	defer cst.close()
+	for _, test := range []struct {
+		name    string
+		handler func(ResponseWriter, *Request)
+	}{{
+		name: "write",
+		handler: func(w ResponseWriter, r *Request) {
+			// Write the whole input at once.
+			n, err := w.Write([]byte(input))
+			if int(n) != len(input) || err != nil {
+				t.Errorf("w.Write(%q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "write one byte at a time",
+		handler: func(w ResponseWriter, r *Request) {
+			// Write the input one byte at a time.
+			buf := []byte(input)
+			for i := range buf {
+				n, err := w.Write(buf[i : i+1])
+				if n != 1 || err != nil {
+					t.Errorf("w.Write(%q) = %v, %v want 1, nil", input, n, err)
+				}
+			}
+		},
+	}, {
+		name: "copy from Reader",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a plain Reader.
+			type readerOnly struct{ io.Reader }
+			buf := bytes.NewBuffer([]byte(input))
+			n, err := io.Copy(w, readerOnly{buf})
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "copy from bytes.Buffer",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a bytes.Buffer to trigger ReadFrom.
+			buf := bytes.NewBuffer([]byte(input))
+			n, err := io.Copy(w, buf)
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "copy one byte at a time",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a Reader that returns one byte at a time.
+			n, err := io.Copy(w, &byteAtATimeReader{[]byte(input)})
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}} {
+		t.Run(test.name, func(t *testing.T) {
+			cst := newClientServerTest(t, h2, HandlerFunc(test.handler))
+			defer cst.close()
+
+			resp, err := cst.c.Get(cst.ts.URL)
+			if err != nil {
+				t.Fatalf("Get: %v", err)
+			}
+			if ct := resp.Header.Get("Content-Type"); ct != expected {
+				t.Errorf("Content-Type = %q, want %q", ct, expected)
+			}
+			if want, got := resp.Header.Get("Content-Length"), fmt.Sprint(len(input)); want != got {
+				t.Errorf("Content-Length = %q, want %q", want, got)
+			}
+			data, err := io.ReadAll(resp.Body)
+			if err != nil {
+				t.Errorf("reading body: %v", err)
+			} else if !bytes.Equal(data, []byte(input)) {
+				t.Errorf("data is %q, want %q", data, input)
+			}
+			resp.Body.Close()
+
+		})
 
-	resp, err := cst.c.Get(cst.ts.URL)
-	if err != nil {
-		t.Fatalf("Get: %v", err)
 	}
-	if ct := resp.Header.Get("Content-Type"); ct != expected {
-		t.Errorf("Content-Type = %q, want %q", ct, expected)
-	}
-	data, err := io.ReadAll(resp.Body)
-	if err != nil {
-		t.Errorf("reading body: %v", err)
-	} else if !bytes.Equal(data, []byte(input)) {
-		t.Errorf("data is %q, want %q", data, input)
-	}
-	resp.Body.Close()
 }
 
 func TestSniffWriteSize_h1(t *testing.T) { testSniffWriteSize(t, h1Mode) }
diff --git a/src/net/http/transfer.go b/src/net/http/transfer.go
index fbb0c39829d..85c2e5a360d 100644
--- a/src/net/http/transfer.go
+++ b/src/net/http/transfer.go
@@ -12,6 +12,7 @@ import (
 	"io"
 	"net/http/httptrace"
 	"net/http/internal"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"reflect"
 	"sort"
@@ -638,7 +639,7 @@ func (t *transferReader) parseTransferEncoding() error {
 	if len(raw) != 1 {
 		return &unsupportedTEError{fmt.Sprintf("too many transfer encodings: %q", raw)}
 	}
-	if strings.ToLower(textproto.TrimString(raw[0])) != "chunked" {
+	if !ascii.EqualFold(textproto.TrimString(raw[0]), "chunked") {
 		return &unsupportedTEError{fmt.Sprintf("unsupported transfer encoding: %q", raw[0])}
 	}
 
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 57018d23924..309194e8e52 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -21,6 +21,7 @@ import (
 	"log"
 	"net"
 	"net/http/httptrace"
+	"net/http/internal/ascii"
 	"net/textproto"
 	"net/url"
 	"os"
@@ -426,6 +427,7 @@ func (t *Transport) onceSetNextProtoDefaults() {
 //
 // The environment values may be either a complete URL or a
 // "host[:port]", in which case the "http" scheme is assumed.
+// The schemes "http", "https", and "socks5" are supported.
 // An error is returned if the value is a different form.
 //
 // A nil URL and nil error are returned if no proxy is defined in the
@@ -2185,7 +2187,7 @@ func (pc *persistConn) readLoop() {
 		}
 
 		resp.Body = body
-		if rc.addedGzip && strings.EqualFold(resp.Header.Get("Content-Encoding"), "gzip") {
+		if rc.addedGzip && ascii.EqualFold(resp.Header.Get("Content-Encoding"), "gzip") {
 			resp.Body = &gzipReader{body: body}
 			resp.Header.Del("Content-Encoding")
 			resp.Header.Del("Content-Length")
diff --git a/src/net/http/transport_internal_test.go b/src/net/http/transport_internal_test.go
index 1097ffd1739..1cce27235df 100644
--- a/src/net/http/transport_internal_test.go
+++ b/src/net/http/transport_internal_test.go
@@ -12,7 +12,7 @@ import (
 	"errors"
 	"io"
 	"net"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"strings"
 	"testing"
 )
@@ -191,7 +191,7 @@ func (f roundTripFunc) RoundTrip(r *Request) (*Response, error) {
 
 // Issue 25009
 func TestTransportBodyAltRewind(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index 5b6a5aa9925..eeaa4926445 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -30,7 +30,7 @@ import (
 	"net/http/httptest"
 	"net/http/httptrace"
 	"net/http/httputil"
-	"net/http/internal"
+	"net/http/internal/testcert"
 	"net/textproto"
 	"net/url"
 	"os"
@@ -4299,7 +4299,7 @@ func TestTransportReuseConnEmptyResponseBody(t *testing.T) {
 
 // Issue 13839
 func TestNoCrashReturningTransportAltConn(t *testing.T) {
-	cert, err := tls.X509KeyPair(internal.LocalhostCert, internal.LocalhostKey)
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -5322,7 +5322,6 @@ func TestMissingStatusNoPanic(t *testing.T) {
 
 	ln := newLocalListener(t)
 	addr := ln.Addr().String()
-	shutdown := make(chan bool, 1)
 	done := make(chan bool)
 	fullAddrURL := fmt.Sprintf("http://%s", addr)
 	raw := "HTTP/1.1 400\r\n" +
@@ -5334,10 +5333,7 @@ func TestMissingStatusNoPanic(t *testing.T) {
 		"Aloha Olaa"
 
 	go func() {
-		defer func() {
-			ln.Close()
-			close(done)
-		}()
+		defer close(done)
 
 		conn, _ := ln.Accept()
 		if conn != nil {
@@ -5368,7 +5364,7 @@ func TestMissingStatusNoPanic(t *testing.T) {
 		t.Errorf("got=%v want=%q", err, want)
 	}
 
-	close(shutdown)
+	ln.Close()
 	<-done
 }
 
@@ -6445,10 +6441,11 @@ func TestErrorWriteLoopRace(t *testing.T) {
 // Test that a new request which uses the connection of an active request
 // cannot cause it to be canceled as well.
 func TestCancelRequestWhenSharingConnection(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping in short mode")
-	}
+	reqc := make(chan chan struct{}, 2)
 	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, req *Request) {
+		ch := make(chan struct{}, 1)
+		reqc <- ch
+		<-ch
 		w.Header().Add("Content-Length", "0")
 	}))
 	defer ts.Close()
@@ -6460,34 +6457,58 @@ func TestCancelRequestWhenSharingConnection(t *testing.T) {
 
 	var wg sync.WaitGroup
 
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-
-	for i := 0; i < 10; i++ {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			for ctx.Err() == nil {
-				reqctx, reqcancel := context.WithCancel(ctx)
-				go reqcancel()
-				req, _ := NewRequestWithContext(reqctx, "GET", ts.URL, nil)
-				res, err := client.Do(req)
-				if err == nil {
-					res.Body.Close()
-				}
-			}
-		}()
-	}
-
-	for ctx.Err() == nil {
-		req, _ := NewRequest("GET", ts.URL, nil)
-		if res, err := client.Do(req); err != nil {
-			t.Errorf("unexpected: %p %v", req, err)
-			break
-		} else {
+	wg.Add(1)
+	putidlec := make(chan chan struct{})
+	go func() {
+		defer wg.Done()
+		ctx := httptrace.WithClientTrace(context.Background(), &httptrace.ClientTrace{
+			PutIdleConn: func(error) {
+				// Signal that the idle conn has been returned to the pool,
+				// and wait for the order to proceed.
+				ch := make(chan struct{})
+				putidlec <- ch
+				<-ch
+			},
+		})
+		req, _ := NewRequestWithContext(ctx, "GET", ts.URL, nil)
+		res, err := client.Do(req)
+		if err == nil {
 			res.Body.Close()
 		}
-	}
+		if err != nil {
+			t.Errorf("request 1: got err %v, want nil", err)
+		}
+	}()
 
+	// Wait for the first request to receive a response and return the
+	// connection to the idle pool.
+	r1c := <-reqc
+	close(r1c)
+	idlec := <-putidlec
+
+	wg.Add(1)
+	cancelctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		defer wg.Done()
+		req, _ := NewRequestWithContext(cancelctx, "GET", ts.URL, nil)
+		res, err := client.Do(req)
+		if err == nil {
+			res.Body.Close()
+		}
+		if !errors.Is(err, context.Canceled) {
+			t.Errorf("request 2: got err %v, want Canceled", err)
+		}
+	}()
+
+	// Wait for the second request to arrive at the server, and then cancel
+	// the request context.
+	r2c := <-reqc
 	cancel()
+
+	// Give the cancelation a moment to take effect, and then unblock the first request.
+	time.Sleep(1 * time.Millisecond)
+	close(idlec)
+
+	close(r2c)
 	wg.Wait()
 }
diff --git a/src/net/ip.go b/src/net/ip.go
index 04772697618..b016bef144a 100644
--- a/src/net/ip.go
+++ b/src/net/ip.go
@@ -308,7 +308,7 @@ func ubtoa(dst []byte, start int, v byte) int {
 // It returns one of 4 forms:
 //   - "", if ip has length 0
 //   - dotted decimal ("192.0.2.1"), if ip is an IPv4 or IP4-mapped IPv6 address
-//   - IPv6 ("2001:db8::1"), if ip is a valid IPv6 address
+//   - IPv6 conforming to RFC 5952 ("2001:db8::1"), if ip is a valid IPv6 address
 //   - the hexadecimal form of ip, without punctuation, if no other cases apply
 func (ip IP) String() string {
 	p := ip
@@ -574,6 +574,10 @@ func parseIPv4(s string) IP {
 		if !ok || n > 0xFF {
 			return nil
 		}
+		if c > 1 && s[0] == '0' {
+			// Reject non-zero components with leading zeroes.
+			return nil
+		}
 		s = s[c:]
 		p[i] = byte(n)
 	}
diff --git a/src/net/ip_test.go b/src/net/ip_test.go
index 3af5e41ceb4..5bbda6024dc 100644
--- a/src/net/ip_test.go
+++ b/src/net/ip_test.go
@@ -21,9 +21,7 @@ var parseIPTests = []struct {
 }{
 	{"127.0.1.2", IPv4(127, 0, 1, 2)},
 	{"127.0.0.1", IPv4(127, 0, 0, 1)},
-	{"127.001.002.003", IPv4(127, 1, 2, 3)},
 	{"::ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
-	{"::ffff:127.001.002.003", IPv4(127, 1, 2, 3)},
 	{"::ffff:7f01:0203", IPv4(127, 1, 2, 3)},
 	{"0:0:0:0:0000:ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
 	{"0:0:0:0:000000:ffff:127.1.2.3", IPv4(127, 1, 2, 3)},
@@ -43,6 +41,11 @@ var parseIPTests = []struct {
 	{"fe80::1%911", nil},
 	{"", nil},
 	{"a1:a2:a3:a4::b1:b2:b3:b4", nil}, // Issue 6628
+	{"127.001.002.003", nil},
+	{"::ffff:127.001.002.003", nil},
+	{"123.000.000.000", nil},
+	{"1.2..4", nil},
+	{"0123.0.0.1", nil},
 }
 
 func TestParseIP(t *testing.T) {
@@ -358,6 +361,7 @@ var parseCIDRTests = []struct {
 	{"0.0.-2.0/32", nil, nil, &ParseError{Type: "CIDR address", Text: "0.0.-2.0/32"}},
 	{"0.0.0.-3/32", nil, nil, &ParseError{Type: "CIDR address", Text: "0.0.0.-3/32"}},
 	{"0.0.0.0/-0", nil, nil, &ParseError{Type: "CIDR address", Text: "0.0.0.0/-0"}},
+	{"127.000.000.001/32", nil, nil, &ParseError{Type: "CIDR address", Text: "127.000.000.001/32"}},
 	{"", nil, nil, &ParseError{Type: "CIDR address", Text: ""}},
 }
 
diff --git a/src/net/lookup.go b/src/net/lookup.go
index 03599503bd1..d350ef7fc03 100644
--- a/src/net/lookup.go
+++ b/src/net/lookup.go
@@ -396,10 +396,13 @@ func (r *Resolver) LookupPort(ctx context.Context, network, service string) (por
 // contain DNS "CNAME" records, as long as host resolves to
 // address records.
 //
+// The returned canonical name is validated to be a properly
+// formatted presentation-format domain name.
+//
 // LookupCNAME uses context.Background internally; to specify the context, use
 // Resolver.LookupCNAME.
 func LookupCNAME(host string) (cname string, err error) {
-	return DefaultResolver.lookupCNAME(context.Background(), host)
+	return DefaultResolver.LookupCNAME(context.Background(), host)
 }
 
 // LookupCNAME returns the canonical name for the given host.
@@ -412,8 +415,18 @@ func LookupCNAME(host string) (cname string, err error) {
 // LookupCNAME does not return an error if host does not
 // contain DNS "CNAME" records, as long as host resolves to
 // address records.
-func (r *Resolver) LookupCNAME(ctx context.Context, host string) (cname string, err error) {
-	return r.lookupCNAME(ctx, host)
+//
+// The returned canonical name is validated to be a properly
+// formatted presentation-format domain name.
+func (r *Resolver) LookupCNAME(ctx context.Context, host string) (string, error) {
+	cname, err := r.lookupCNAME(ctx, host)
+	if err != nil {
+		return "", err
+	}
+	if !isDomainName(cname) {
+		return "", &DNSError{Err: errMalformedDNSRecordsDetail, Name: host}
+	}
+	return cname, nil
 }
 
 // LookupSRV tries to resolve an SRV query of the given service,
@@ -425,8 +438,13 @@ func (r *Resolver) LookupCNAME(ctx context.Context, host string) (cname string,
 // That is, it looks up _service._proto.name. To accommodate services
 // publishing SRV records under non-standard names, if both service
 // and proto are empty strings, LookupSRV looks up name directly.
+//
+// The returned service names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
 func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
-	return DefaultResolver.lookupSRV(context.Background(), service, proto, name)
+	return DefaultResolver.LookupSRV(context.Background(), service, proto, name)
 }
 
 // LookupSRV tries to resolve an SRV query of the given service,
@@ -438,34 +456,115 @@ func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
 // That is, it looks up _service._proto.name. To accommodate services
 // publishing SRV records under non-standard names, if both service
 // and proto are empty strings, LookupSRV looks up name directly.
-func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*SRV, err error) {
-	return r.lookupSRV(ctx, service, proto, name)
+//
+// The returned service names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
+func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV, error) {
+	cname, addrs, err := r.lookupSRV(ctx, service, proto, name)
+	if err != nil {
+		return "", nil, err
+	}
+	if cname != "" && !isDomainName(cname) {
+		return "", nil, &DNSError{Err: "SRV header name is invalid", Name: name}
+	}
+	filteredAddrs := make([]*SRV, 0, len(addrs))
+	for _, addr := range addrs {
+		if addr == nil {
+			continue
+		}
+		if !isDomainName(addr.Target) {
+			continue
+		}
+		filteredAddrs = append(filteredAddrs, addr)
+	}
+	if len(addrs) != len(filteredAddrs) {
+		return cname, filteredAddrs, &DNSError{Err: errMalformedDNSRecordsDetail, Name: name}
+	}
+	return cname, filteredAddrs, nil
 }
 
 // LookupMX returns the DNS MX records for the given domain name sorted by preference.
 //
+// The returned mail server names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
+//
 // LookupMX uses context.Background internally; to specify the context, use
 // Resolver.LookupMX.
 func LookupMX(name string) ([]*MX, error) {
-	return DefaultResolver.lookupMX(context.Background(), name)
+	return DefaultResolver.LookupMX(context.Background(), name)
 }
 
 // LookupMX returns the DNS MX records for the given domain name sorted by preference.
+//
+// The returned mail server names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
 func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
-	return r.lookupMX(ctx, name)
+	records, err := r.lookupMX(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	filteredMX := make([]*MX, 0, len(records))
+	for _, mx := range records {
+		if mx == nil {
+			continue
+		}
+		// Bypass the hostname validity check for targets which contain only a dot,
+		// as this is used to represent a 'Null' MX record.
+		if mx.Host != "." && !isDomainName(mx.Host) {
+			continue
+		}
+		filteredMX = append(filteredMX, mx)
+	}
+	if len(records) != len(filteredMX) {
+		return filteredMX, &DNSError{Err: errMalformedDNSRecordsDetail, Name: name}
+	}
+	return filteredMX, nil
 }
 
 // LookupNS returns the DNS NS records for the given domain name.
 //
+// The returned name server names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
+//
 // LookupNS uses context.Background internally; to specify the context, use
 // Resolver.LookupNS.
 func LookupNS(name string) ([]*NS, error) {
-	return DefaultResolver.lookupNS(context.Background(), name)
+	return DefaultResolver.LookupNS(context.Background(), name)
 }
 
 // LookupNS returns the DNS NS records for the given domain name.
+//
+// The returned name server names are validated to be properly
+// formatted presentation-format domain names. If the response contains
+// invalid names, those records are filtered out and an error
+// will be returned alongside the the remaining results, if any.
 func (r *Resolver) LookupNS(ctx context.Context, name string) ([]*NS, error) {
-	return r.lookupNS(ctx, name)
+	records, err := r.lookupNS(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	filteredNS := make([]*NS, 0, len(records))
+	for _, ns := range records {
+		if ns == nil {
+			continue
+		}
+		if !isDomainName(ns.Host) {
+			continue
+		}
+		filteredNS = append(filteredNS, ns)
+	}
+	if len(records) != len(filteredNS) {
+		return filteredNS, &DNSError{Err: errMalformedDNSRecordsDetail, Name: name}
+	}
+	return filteredNS, nil
 }
 
 // LookupTXT returns the DNS TXT records for the given domain name.
@@ -484,17 +583,43 @@ func (r *Resolver) LookupTXT(ctx context.Context, name string) ([]string, error)
 // LookupAddr performs a reverse lookup for the given address, returning a list
 // of names mapping to that address.
 //
+// The returned names are validated to be properly formatted presentation-format
+// domain names. If the response contains invalid names, those records are filtered
+// out and an error will be returned alongside the the remaining results, if any.
+//
 // When using the host C library resolver, at most one result will be
 // returned. To bypass the host resolver, use a custom Resolver.
 //
 // LookupAddr uses context.Background internally; to specify the context, use
 // Resolver.LookupAddr.
 func LookupAddr(addr string) (names []string, err error) {
-	return DefaultResolver.lookupAddr(context.Background(), addr)
+	return DefaultResolver.LookupAddr(context.Background(), addr)
 }
 
 // LookupAddr performs a reverse lookup for the given address, returning a list
 // of names mapping to that address.
-func (r *Resolver) LookupAddr(ctx context.Context, addr string) (names []string, err error) {
-	return r.lookupAddr(ctx, addr)
+//
+// The returned names are validated to be properly formatted presentation-format
+// domain names. If the response contains invalid names, those records are filtered
+// out and an error will be returned alongside the the remaining results, if any.
+func (r *Resolver) LookupAddr(ctx context.Context, addr string) ([]string, error) {
+	names, err := r.lookupAddr(ctx, addr)
+	if err != nil {
+		return nil, err
+	}
+	filteredNames := make([]string, 0, len(names))
+	for _, name := range names {
+		if isDomainName(name) {
+			filteredNames = append(filteredNames, name)
+		}
+	}
+	if len(names) != len(filteredNames) {
+		return filteredNames, &DNSError{Err: errMalformedDNSRecordsDetail, Name: addr}
+	}
+	return filteredNames, nil
 }
+
+// errMalformedDNSRecordsDetail is the DNSError detail which is returned when a Resolver.Lookup...
+// method recieves DNS records which contain invalid DNS names. This may be returned alongside
+// results which have had the malformed records filtered out.
+var errMalformedDNSRecordsDetail = "DNS response contained records which contain invalid names"
diff --git a/src/net/lookup_windows_test.go b/src/net/lookup_windows_test.go
index 62b61ed6c2f..aa95501d023 100644
--- a/src/net/lookup_windows_test.go
+++ b/src/net/lookup_windows_test.go
@@ -299,7 +299,7 @@ func lookupPTR(name string) (ptr []string, err error) {
 	ptr = make([]string, 0, 10)
 	rx := regexp.MustCompile(`(?m)^Pinging\s+([a-zA-Z0-9.\-]+)\s+\[.*$`)
 	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
-		ptr = append(ptr, ans[1]+".")
+		ptr = append(ptr, absDomainName([]byte(ans[1])))
 	}
 	return
 }
diff --git a/src/net/server_test.go b/src/net/server_test.go
index 8d4db7233d1..7cbf1522988 100644
--- a/src/net/server_test.go
+++ b/src/net/server_test.go
@@ -105,13 +105,6 @@ func TestTCPServer(t *testing.T) {
 					if perr := parseDialError(err); perr != nil {
 						t.Error(perr)
 					}
-					if tt.taddr == "::1" && os.Getenv("GO_BUILDER_NAME") == "darwin-amd64-10_12" && os.IsTimeout(err) {
-						// A suspected kernel bug in macOS 10.12 occasionally results in
-						// "i/o timeout" errors when dialing address ::1. The errors have not
-						// been observed on newer versions of the OS, so we don't plan to work
-						// around them. See https://golang.org/issue/32919.
-						t.Skipf("skipping due to error on known-flaky macOS 10.12 builder: %v", err)
-					}
 					t.Fatal(err)
 				}
 				defer c.Close()
diff --git a/src/net/testdata/ipv4-hosts b/src/net/testdata/ipv4-hosts
index 5208bb44ac8..6b99675dfc8 100644
--- a/src/net/testdata/ipv4-hosts
+++ b/src/net/testdata/ipv4-hosts
@@ -1,12 +1,8 @@
 # See https://tools.ietf.org/html/rfc1123.
-#
-# The literal IPv4 address parser in the net package is a relaxed
-# one. It may accept a literal IPv4 address in dotted-decimal notation
-# with leading zeros such as "001.2.003.4".
 
 # internet address and host name
 127.0.0.1	localhost	# inline comment separated by tab
-127.000.000.002	localhost       # inline comment separated by space
+127.0.0.2	localhost   # inline comment separated by space
 
 # internet address, host name and aliases
-127.000.000.003	localhost	localhost.localdomain
+127.0.0.3	localhost	localhost.localdomain
diff --git a/src/net/udpsock_posix.go b/src/net/udpsock_posix.go
index fcfb9c004cd..96fb373ce77 100644
--- a/src/net/udpsock_posix.go
+++ b/src/net/udpsock_posix.go
@@ -50,6 +50,9 @@ func (c *UDPConn) readFrom(b []byte, addr *UDPAddr) (int, *UDPAddr, error) {
 		*addr = UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
 	case *syscall.SockaddrInet6:
 		*addr = UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
+	default:
+		// No sockaddr, so don't return UDPAddr.
+		addr = nil
 	}
 	return n, addr, err
 }
diff --git a/src/net/udpsock_test.go b/src/net/udpsock_test.go
index b4000b5664d..0e8c3511c36 100644
--- a/src/net/udpsock_test.go
+++ b/src/net/udpsock_test.go
@@ -8,7 +8,9 @@
 package net
 
 import (
+	"errors"
 	"internal/testenv"
+	"os"
 	"reflect"
 	"runtime"
 	"testing"
@@ -446,6 +448,33 @@ func TestUDPReadSizeError(t *testing.T) {
 	}
 }
 
+// TestUDPReadTimeout verifies that ReadFromUDP with timeout returns an error
+// without data or an address.
+func TestUDPReadTimeout(t *testing.T) {
+	la, err := ResolveUDPAddr("udp4", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, err := ListenUDP("udp4", la)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	c.SetDeadline(time.Now())
+	b := make([]byte, 1)
+	n, addr, err := c.ReadFromUDP(b)
+	if !errors.Is(err, os.ErrDeadlineExceeded) {
+		t.Errorf("ReadFromUDP got err %v want os.ErrDeadlineExceeded", err)
+	}
+	if n != 0 {
+		t.Errorf("ReadFromUDP got n %d want 0", n)
+	}
+	if addr != nil {
+		t.Errorf("ReadFromUDP got addr %+#v want nil", addr)
+	}
+}
+
 func BenchmarkWriteToReadFromUDP(b *testing.B) {
 	conn, err := ListenUDP("udp4", &UDPAddr{IP: IPv4(127, 0, 0, 1)})
 	if err != nil {
diff --git a/src/net/url/example_test.go b/src/net/url/example_test.go
index cb9e8922a2e..476132a1c93 100644
--- a/src/net/url/example_test.go
+++ b/src/net/url/example_test.go
@@ -72,13 +72,13 @@ func ExampleURL_ResolveReference() {
 }
 
 func ExampleParseQuery() {
-	m, err := url.ParseQuery(`x=1&y=2&y=3;z`)
+	m, err := url.ParseQuery(`x=1&y=2&y=3`)
 	if err != nil {
 		log.Fatal(err)
 	}
 	fmt.Println(toJSON(m))
 	// Output:
-	// {"x":["1"], "y":["2", "3"], "z":[""]}
+	// {"x":["1"], "y":["2", "3"]}
 }
 
 func ExampleURL_EscapedPath() {
diff --git a/src/net/url/url.go b/src/net/url/url.go
index 73bef22e456..20de0f6f517 100644
--- a/src/net/url/url.go
+++ b/src/net/url/url.go
@@ -921,9 +921,10 @@ func (v Values) Has(key string) bool {
 // valid query parameters found; err describes the first decoding error
 // encountered, if any.
 //
-// Query is expected to be a list of key=value settings separated by
-// ampersands or semicolons. A setting without an equals sign is
-// interpreted as a key set to an empty value.
+// Query is expected to be a list of key=value settings separated by ampersands.
+// A setting without an equals sign is interpreted as a key set to an empty
+// value.
+// Settings containing a non-URL-encoded semicolon are considered invalid.
 func ParseQuery(query string) (Values, error) {
 	m := make(Values)
 	err := parseQuery(m, query)
@@ -933,11 +934,15 @@ func ParseQuery(query string) (Values, error) {
 func parseQuery(m Values, query string) (err error) {
 	for query != "" {
 		key := query
-		if i := strings.IndexAny(key, "&;"); i >= 0 {
+		if i := strings.IndexAny(key, "&"); i >= 0 {
 			key, query = key[:i], key[i+1:]
 		} else {
 			query = ""
 		}
+		if strings.Contains(key, ";") {
+			err = fmt.Errorf("invalid semicolon separator in query")
+			continue
+		}
 		if key == "" {
 			continue
 		}
diff --git a/src/net/url/url_test.go b/src/net/url/url_test.go
index 55348c4a7da..63c8e695af7 100644
--- a/src/net/url/url_test.go
+++ b/src/net/url/url_test.go
@@ -1334,57 +1334,125 @@ func TestQueryValues(t *testing.T) {
 type parseTest struct {
 	query string
 	out   Values
+	ok    bool
 }
 
 var parseTests = []parseTest{
+	{
+		query: "a=1",
+		out:   Values{"a": []string{"1"}},
+		ok:    true,
+	},
 	{
 		query: "a=1&b=2",
 		out:   Values{"a": []string{"1"}, "b": []string{"2"}},
+		ok:    true,
 	},
 	{
 		query: "a=1&a=2&a=banana",
 		out:   Values{"a": []string{"1", "2", "banana"}},
+		ok:    true,
 	},
 	{
 		query: "ascii=%3Ckey%3A+0x90%3E",
 		out:   Values{"ascii": []string{""}},
+		ok:    true,
+	}, {
+		query: "a=1;b=2",
+		out:   Values{},
+		ok:    false,
+	}, {
+		query: "a;b=1",
+		out:   Values{},
+		ok:    false,
+	}, {
+		query: "a=%3B", // hex encoding for semicolon
+		out:   Values{"a": []string{";"}},
+		ok:    true,
 	},
 	{
-		query: "a=1;b=2",
-		out:   Values{"a": []string{"1"}, "b": []string{"2"}},
+		query: "a%3Bb=1",
+		out:   Values{"a;b": []string{"1"}},
+		ok:    true,
 	},
 	{
 		query: "a=1&a=2;a=banana",
-		out:   Values{"a": []string{"1", "2", "banana"}},
+		out:   Values{"a": []string{"1"}},
+		ok:    false,
+	},
+	{
+		query: "a;b&c=1",
+		out:   Values{"c": []string{"1"}},
+		ok:    false,
+	},
+	{
+		query: "a=1&b=2;a=3&c=4",
+		out:   Values{"a": []string{"1"}, "c": []string{"4"}},
+		ok:    false,
+	},
+	{
+		query: "a=1&b=2;c=3",
+		out:   Values{"a": []string{"1"}},
+		ok:    false,
+	},
+	{
+		query: ";",
+		out:   Values{},
+		ok:    false,
+	},
+	{
+		query: "a=1;",
+		out:   Values{},
+		ok:    false,
+	},
+	{
+		query: "a=1&;",
+		out:   Values{"a": []string{"1"}},
+		ok:    false,
+	},
+	{
+		query: ";a=1&b=2",
+		out:   Values{"b": []string{"2"}},
+		ok:    false,
+	},
+	{
+		query: "a=1&b=2;",
+		out:   Values{"a": []string{"1"}},
+		ok:    false,
 	},
 }
 
 func TestParseQuery(t *testing.T) {
-	for i, test := range parseTests {
-		form, err := ParseQuery(test.query)
-		if err != nil {
-			t.Errorf("test %d: Unexpected error: %v", i, err)
-			continue
-		}
-		if len(form) != len(test.out) {
-			t.Errorf("test %d: len(form) = %d, want %d", i, len(form), len(test.out))
-		}
-		for k, evs := range test.out {
-			vs, ok := form[k]
-			if !ok {
-				t.Errorf("test %d: Missing key %q", i, k)
-				continue
+	for _, test := range parseTests {
+		t.Run(test.query, func(t *testing.T) {
+			form, err := ParseQuery(test.query)
+			if test.ok != (err == nil) {
+				want := ""
+				if test.ok {
+					want = ""
+				}
+				t.Errorf("Unexpected error: %v, want %v", err, want)
 			}
-			if len(vs) != len(evs) {
-				t.Errorf("test %d: len(form[%q]) = %d, want %d", i, k, len(vs), len(evs))
-				continue
+			if len(form) != len(test.out) {
+				t.Errorf("len(form) = %d, want %d", len(form), len(test.out))
 			}
-			for j, ev := range evs {
-				if v := vs[j]; v != ev {
-					t.Errorf("test %d: form[%q][%d] = %q, want %q", i, k, j, v, ev)
+			for k, evs := range test.out {
+				vs, ok := form[k]
+				if !ok {
+					t.Errorf("Missing key %q", k)
+					continue
+				}
+				if len(vs) != len(evs) {
+					t.Errorf("len(form[%q]) = %d, want %d", k, len(vs), len(evs))
+					continue
+				}
+				for j, ev := range evs {
+					if v := vs[j]; v != ev {
+						t.Errorf("form[%q][%d] = %q, want %q", k, j, v, ev)
+					}
 				}
 			}
-		}
+		})
 	}
 }
 
diff --git a/src/os/example_test.go b/src/os/example_test.go
index 3adce517848..e8554b0b122 100644
--- a/src/os/example_test.go
+++ b/src/os/example_test.go
@@ -5,6 +5,7 @@
 package os_test
 
 import (
+	"errors"
 	"fmt"
 	"io/fs"
 	"log"
@@ -71,9 +72,9 @@ func ExampleFileMode() {
 	}
 }
 
-func ExampleIsNotExist() {
+func ExampleErrNotExist() {
 	filename := "a-nonexistent-file"
-	if _, err := os.Stat(filename); os.IsNotExist(err) {
+	if _, err := os.Stat(filename); errors.Is(err, fs.ErrNotExist) {
 		fmt.Println("file does not exist")
 	}
 	// Output:
diff --git a/src/os/exec.go b/src/os/exec.go
index edb773a092b..bc75d4dd66c 100644
--- a/src/os/exec.go
+++ b/src/os/exec.go
@@ -54,6 +54,9 @@ type ProcAttr struct {
 	// standard error. An implementation may support additional entries,
 	// depending on the underlying operating system. A nil entry corresponds
 	// to that file being closed when the process starts.
+	// On Unix systems, StartProcess will change these File values
+	// to blocking mode, which means that SetDeadline will stop working
+	// and calling Close will not interrupt a Read or Write.
 	Files []*File
 
 	// Operating system-specific process creation attributes.
diff --git a/src/os/exec/lp_windows_test.go b/src/os/exec/lp_windows_test.go
index f834ffede03..bbf6a9b7f13 100644
--- a/src/os/exec/lp_windows_test.go
+++ b/src/os/exec/lp_windows_test.go
@@ -312,9 +312,6 @@ func TestLookPath(t *testing.T) {
 	// Run all tests.
 	for i, test := range lookPathTests {
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
-			if i == 16 {
-				t.Skip("golang.org/issue/44379")
-			}
 			dir := filepath.Join(tmp, "d"+strconv.Itoa(i))
 			err := os.Mkdir(dir, 0700)
 			if err != nil {
diff --git a/src/os/exec_windows.go b/src/os/exec_windows.go
index 5710401acdb..239bed198f7 100644
--- a/src/os/exec_windows.go
+++ b/src/os/exec_windows.go
@@ -45,16 +45,6 @@ func (p *Process) wait() (ps *ProcessState, err error) {
 	return &ProcessState{p.Pid, syscall.WaitStatus{ExitCode: ec}, &u}, nil
 }
 
-func terminateProcess(pid, exitcode int) error {
-	h, e := syscall.OpenProcess(syscall.PROCESS_TERMINATE, false, uint32(pid))
-	if e != nil {
-		return NewSyscallError("OpenProcess", e)
-	}
-	defer syscall.CloseHandle(h)
-	e = syscall.TerminateProcess(h, uint32(exitcode))
-	return NewSyscallError("TerminateProcess", e)
-}
-
 func (p *Process) signal(sig Signal) error {
 	handle := atomic.LoadUintptr(&p.handle)
 	if handle == uintptr(syscall.InvalidHandle) {
@@ -64,16 +54,22 @@ func (p *Process) signal(sig Signal) error {
 		return ErrProcessDone
 	}
 	if sig == Kill {
-		err := terminateProcess(p.Pid, 1)
+		var terminationHandle syscall.Handle
+		e := syscall.DuplicateHandle(^syscall.Handle(0), syscall.Handle(handle), ^syscall.Handle(0), &terminationHandle, syscall.PROCESS_TERMINATE, false, 0)
+		if e != nil {
+			return NewSyscallError("DuplicateHandle", e)
+		}
 		runtime.KeepAlive(p)
-		return err
+		defer syscall.CloseHandle(terminationHandle)
+		e = syscall.TerminateProcess(syscall.Handle(terminationHandle), 1)
+		return NewSyscallError("TerminateProcess", e)
 	}
 	// TODO(rsc): Handle Interrupt too?
 	return syscall.Errno(syscall.EWINDOWS)
 }
 
 func (p *Process) release() error {
-	handle := atomic.LoadUintptr(&p.handle)
+	handle := atomic.SwapUintptr(&p.handle, uintptr(syscall.InvalidHandle))
 	if handle == uintptr(syscall.InvalidHandle) {
 		return syscall.EINVAL
 	}
@@ -81,7 +77,6 @@ func (p *Process) release() error {
 	if e != nil {
 		return NewSyscallError("CloseHandle", e)
 	}
-	atomic.StoreUintptr(&p.handle, uintptr(syscall.InvalidHandle))
 	// no need for a finalizer anymore
 	runtime.SetFinalizer(p, nil)
 	return nil
diff --git a/src/os/fifo_test.go b/src/os/fifo_test.go
index 9b262f8205a..007ed291293 100644
--- a/src/os/fifo_test.go
+++ b/src/os/fifo_test.go
@@ -26,9 +26,6 @@ func TestFifoEOF(t *testing.T) {
 	switch runtime.GOOS {
 	case "android":
 		t.Skip("skipping on Android; mkfifo syscall not available")
-	case "openbsd":
-		// On OpenBSD 6.2 this test just hangs for some reason.
-		t.Skip("skipping on OpenBSD; issue 25877")
 	}
 
 	dir := t.TempDir()
diff --git a/src/os/pipe_test.go b/src/os/pipe_test.go
index b6636185029..41a1e9c78aa 100644
--- a/src/os/pipe_test.go
+++ b/src/os/pipe_test.go
@@ -442,12 +442,14 @@ func TestFdReadRace(t *testing.T) {
 	defer r.Close()
 	defer w.Close()
 
-	c := make(chan bool)
+	const count = 10
+
+	c := make(chan bool, 1)
 	var wg sync.WaitGroup
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		var buf [10]byte
+		var buf [count]byte
 		r.SetReadDeadline(time.Now().Add(time.Minute))
 		c <- true
 		if _, err := r.Read(buf[:]); os.IsTimeout(err) {
@@ -466,8 +468,9 @@ func TestFdReadRace(t *testing.T) {
 		r.Fd()
 
 		// The bug was that Fd would hang until Read timed out.
-		// If the bug is fixed, then closing r here will cause
-		// the Read to exit before the timeout expires.
+		// If the bug is fixed, then writing to w and closing r here
+		// will cause the Read to exit before the timeout expires.
+		w.Write(make([]byte, count))
 		r.Close()
 	}()
 
diff --git a/src/os/signal/signal_test.go b/src/os/signal/signal_test.go
index cea68742d26..649854b746c 100644
--- a/src/os/signal/signal_test.go
+++ b/src/os/signal/signal_test.go
@@ -32,6 +32,11 @@ import (
 // The current value is set based on flakes observed in the Go builders.
 var settleTime = 100 * time.Millisecond
 
+// fatalWaitingTime is an absurdly long time to wait for signals to be
+// delivered but, using it, we (hopefully) eliminate test flakes on the
+// build servers. See #46736 for discussion.
+var fatalWaitingTime = 30 * time.Second
+
 func init() {
 	if testenv.Builder() == "solaris-amd64-oraclerel" {
 		// The solaris-amd64-oraclerel builder has been observed to time out in
@@ -84,7 +89,7 @@ func waitSig1(t *testing.T, c <-chan os.Signal, sig os.Signal, all bool) {
 	// General user code should filter out all unexpected signals instead of just
 	// SIGURG, but since os/signal is tightly coupled to the runtime it seems
 	// appropriate to be stricter here.
-	for time.Since(start) < settleTime {
+	for time.Since(start) < fatalWaitingTime {
 		select {
 		case s := <-c:
 			if s == sig {
@@ -97,7 +102,7 @@ func waitSig1(t *testing.T, c <-chan os.Signal, sig os.Signal, all bool) {
 			timer.Reset(settleTime / 10)
 		}
 	}
-	t.Fatalf("timeout after %v waiting for %v", settleTime, sig)
+	t.Fatalf("timeout after %v waiting for %v", fatalWaitingTime, sig)
 }
 
 // quiesce waits until we can be reasonably confident that all pending signals
diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
index cd107b6c85a..bc5509b49cf 100644
--- a/src/path/filepath/path_test.go
+++ b/src/path/filepath/path_test.go
@@ -1469,11 +1469,16 @@ func TestEvalSymlinksAboveRoot(t *testing.T) {
 	// Try different numbers of "..".
 	for _, i := range []int{c, c + 1, c + 2} {
 		check := strings.Join([]string{evalTmpDir, strings.Join(dd[:i], string(os.PathSeparator)), evalTmpDir[len(vol)+1:], "b", "file"}, string(os.PathSeparator))
-		if resolved, err := filepath.EvalSymlinks(check); err != nil {
+		resolved, err := filepath.EvalSymlinks(check)
+		switch {
+		case runtime.GOOS == "darwin" && errors.Is(err, fs.ErrNotExist):
+			// On darwin, the temp dir is sometimes cleaned up mid-test (issue 37910).
+			testenv.SkipFlaky(t, 37910)
+		case err != nil:
 			t.Errorf("EvalSymlinks(%q) failed: %v", check, err)
-		} else if !strings.HasSuffix(resolved, wantSuffix) {
+		case !strings.HasSuffix(resolved, wantSuffix):
 			t.Errorf("EvalSymlinks(%q) = %q does not end with %q", check, resolved, wantSuffix)
-		} else {
+		default:
 			t.Logf("EvalSymlinks(%q) = %q", check, resolved)
 		}
 	}
diff --git a/src/reflect/abi.go b/src/reflect/abi.go
index 17b79a8394f..9ddde3ae57c 100644
--- a/src/reflect/abi.go
+++ b/src/reflect/abi.go
@@ -6,6 +6,7 @@ package reflect
 
 import (
 	"internal/abi"
+	"internal/goarch"
 	"internal/goexperiment"
 	"unsafe"
 )
@@ -167,7 +168,7 @@ func (a *abiSeq) addRcvr(rcvr *rtype) (*abiStep, bool) {
 	a.valueStart = append(a.valueStart, len(a.steps))
 	var ok, ptr bool
 	if ifaceIndir(rcvr) || rcvr.pointers() {
-		ok = a.assignIntN(0, ptrSize, 1, 0b1)
+		ok = a.assignIntN(0, goarch.PtrSize, 1, 0b1)
 		ptr = true
 	} else {
 		// TODO(mknyszek): Is this case even possible?
@@ -176,11 +177,11 @@ func (a *abiSeq) addRcvr(rcvr *rtype) (*abiStep, bool) {
 		// in the reflect package which only conditionally added
 		// a pointer bit to the reflect.(Value).Call stack frame's
 		// GC bitmap.
-		ok = a.assignIntN(0, ptrSize, 1, 0b0)
+		ok = a.assignIntN(0, goarch.PtrSize, 1, 0b0)
 		ptr = false
 	}
 	if !ok {
-		a.stackAssign(ptrSize, ptrSize)
+		a.stackAssign(goarch.PtrSize, goarch.PtrSize)
 		return &a.steps[len(a.steps)-1], ptr
 	}
 	return nil, ptr
@@ -202,7 +203,7 @@ func (a *abiSeq) regAssign(t *rtype, offset uintptr) bool {
 	case Bool, Int, Uint, Int8, Uint8, Int16, Uint16, Int32, Uint32, Uintptr:
 		return a.assignIntN(offset, t.size, 1, 0b0)
 	case Int64, Uint64:
-		switch ptrSize {
+		switch goarch.PtrSize {
 		case 4:
 			return a.assignIntN(offset, 4, 2, 0b0)
 		case 8:
@@ -215,11 +216,11 @@ func (a *abiSeq) regAssign(t *rtype, offset uintptr) bool {
 	case Complex128:
 		return a.assignFloatN(offset, 8, 2)
 	case String:
-		return a.assignIntN(offset, ptrSize, 2, 0b01)
+		return a.assignIntN(offset, goarch.PtrSize, 2, 0b01)
 	case Interface:
-		return a.assignIntN(offset, ptrSize, 2, 0b10)
+		return a.assignIntN(offset, goarch.PtrSize, 2, 0b10)
 	case Slice:
-		return a.assignIntN(offset, ptrSize, 3, 0b001)
+		return a.assignIntN(offset, goarch.PtrSize, 3, 0b001)
 	case Array:
 		tt := (*arrayType)(unsafe.Pointer(t))
 		switch tt.len {
@@ -262,7 +263,7 @@ func (a *abiSeq) assignIntN(offset, size uintptr, n int, ptrMap uint8) bool {
 	if n > 8 || n < 0 {
 		panic("invalid n")
 	}
-	if ptrMap != 0 && size != ptrSize {
+	if ptrMap != 0 && size != goarch.PtrSize {
 		panic("non-empty pointer map passed for non-pointer-size values")
 	}
 	if a.iregs+n > intArgRegs {
@@ -413,7 +414,7 @@ func newAbiDesc(t *funcType, rcvr *rtype) abiDesc {
 				stackPtrs.append(0)
 			}
 		} else {
-			spill += ptrSize
+			spill += goarch.PtrSize
 		}
 	}
 	for i, arg := range t.in() {
@@ -430,12 +431,12 @@ func newAbiDesc(t *funcType, rcvr *rtype) abiDesc {
 			}
 		}
 	}
-	spill = align(spill, ptrSize)
+	spill = align(spill, goarch.PtrSize)
 
 	// From the input parameters alone, we now know
 	// the stackCallArgsSize and retOffset.
 	stackCallArgsSize := in.stackBytes
-	retOffset := align(in.stackBytes, ptrSize)
+	retOffset := align(in.stackBytes, goarch.PtrSize)
 
 	// Compute the stack frame pointer bitmap and register
 	// pointer bitmap for return values.
diff --git a/src/reflect/abi_test.go b/src/reflect/abi_test.go
index 1a2a48b5ed9..2b247d1d798 100644
--- a/src/reflect/abi_test.go
+++ b/src/reflect/abi_test.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build goexperiment.regabireflect
-// +build goexperiment.regabireflect
+//go:build goexperiment.regabireflect && goexperiment.regabiargs
+// +build goexperiment.regabireflect,goexperiment.regabiargs
 
 package reflect_test
 
@@ -79,7 +79,34 @@ func TestMethodValueCallABI(t *testing.T) {
 		t.Errorf("bad method value call: got %#v, want %#v", r2, a2)
 	}
 	if s.Value != 3 {
-		t.Errorf("bad method value call: failed to set s.Value: got %d, want %d", s.Value, 1)
+		t.Errorf("bad method value call: failed to set s.Value: got %d, want %d", s.Value, 3)
+	}
+
+	s, i = makeMethodValue("ValueRegMethodSpillInt")
+	f3 := i.(func(StructFillRegs, int, MagicLastTypeNameForTestingRegisterABI) (StructFillRegs, int))
+	r3a, r3b := f3(a2, 42, MagicLastTypeNameForTestingRegisterABI{})
+	if r3a != a2 {
+		t.Errorf("bad method value call: got %#v, want %#v", r3a, a2)
+	}
+	if r3b != 42 {
+		t.Errorf("bad method value call: got %#v, want %#v", r3b, 42)
+	}
+	if s.Value != 4 {
+		t.Errorf("bad method value call: failed to set s.Value: got %d, want %d", s.Value, 4)
+	}
+
+	s, i = makeMethodValue("ValueRegMethodSpillPtr")
+	f4 := i.(func(StructFillRegs, *byte, MagicLastTypeNameForTestingRegisterABI) (StructFillRegs, *byte))
+	vb := byte(10)
+	r4a, r4b := f4(a2, &vb, MagicLastTypeNameForTestingRegisterABI{})
+	if r4a != a2 {
+		t.Errorf("bad method value call: got %#v, want %#v", r4a, a2)
+	}
+	if r4b != &vb {
+		t.Errorf("bad method value call: got %#v, want %#v", r4b, &vb)
+	}
+	if s.Value != 5 {
+		t.Errorf("bad method value call: failed to set s.Value: got %d, want %d", s.Value, 5)
 	}
 }
 
@@ -112,6 +139,20 @@ func (m *StructWithMethods) SpillStructCall(s StructFillRegs, _ MagicLastTypeNam
 	return s
 }
 
+// When called as a method value, i is passed on the stack.
+// When called as a method, i is passed in a register.
+func (m *StructWithMethods) ValueRegMethodSpillInt(s StructFillRegs, i int, _ MagicLastTypeNameForTestingRegisterABI) (StructFillRegs, int) {
+	m.Value = 4
+	return s, i
+}
+
+// When called as a method value, i is passed on the stack.
+// When called as a method, i is passed in a register.
+func (m *StructWithMethods) ValueRegMethodSpillPtr(s StructFillRegs, i *byte, _ MagicLastTypeNameForTestingRegisterABI) (StructFillRegs, *byte) {
+	m.Value = 5
+	return s, i
+}
+
 func TestReflectCallABI(t *testing.T) {
 	// Enable register-based reflect.Call and ensure we don't
 	// use potentially incorrect cached versions by clearing
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index 065ff046115..5e5e4c1e604 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -10,6 +10,7 @@ import (
 	"flag"
 	"fmt"
 	"go/token"
+	"internal/goarch"
 	"io"
 	"math"
 	"math/rand"
@@ -4304,6 +4305,9 @@ func TestConvert(t *testing.T) {
 
 		// vout1 represents the in value converted to the in type.
 		v1 := tt.in
+		if !v1.CanConvert(t1) {
+			t.Errorf("ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t1)
+		}
 		vout1 := v1.Convert(t1)
 		out1 := vout1.Interface()
 		if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
@@ -4311,6 +4315,9 @@ func TestConvert(t *testing.T) {
 		}
 
 		// vout2 represents the in value converted to the out type.
+		if !v1.CanConvert(t2) {
+			t.Errorf("ValueOf(%T(%[1]v)).CanConvert(%s) = false, want true", tt.in.Interface(), t2)
+		}
 		vout2 := v1.Convert(t2)
 		out2 := vout2.Interface()
 		if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) {
@@ -4371,7 +4378,10 @@ func TestConvertPanic(t *testing.T) {
 	if !v.Type().ConvertibleTo(pt) {
 		t.Errorf("[]byte should be convertible to *[8]byte")
 	}
-	shouldPanic("reflect: cannot convert slice with length 4 to array pointer with length 8", func() {
+	if v.CanConvert(pt) {
+		t.Errorf("slice with length 4 should not be convertible to *[8]byte")
+	}
+	shouldPanic("reflect: cannot convert slice with length 4 to pointer to array with length 8", func() {
 		_ = v.Convert(pt)
 	})
 }
@@ -6457,10 +6467,10 @@ func clobber() {
 
 func TestFuncLayout(t *testing.T) {
 	align := func(x uintptr) uintptr {
-		return (x + PtrSize - 1) &^ (PtrSize - 1)
+		return (x + goarch.PtrSize - 1) &^ (goarch.PtrSize - 1)
 	}
 	var r []byte
-	if PtrSize == 4 {
+	if goarch.PtrSize == 4 {
 		r = []byte{0, 0, 0, 1}
 	} else {
 		r = []byte{0, 0, 1}
@@ -6481,56 +6491,56 @@ func TestFuncLayout(t *testing.T) {
 	tests := []test{
 		{
 			typ:       ValueOf(func(a, b string) string { return "" }).Type(),
-			size:      6 * PtrSize,
-			argsize:   4 * PtrSize,
-			retOffset: 4 * PtrSize,
+			size:      6 * goarch.PtrSize,
+			argsize:   4 * goarch.PtrSize,
+			retOffset: 4 * goarch.PtrSize,
 			stack:     []byte{1, 0, 1, 0, 1},
 			gc:        []byte{1, 0, 1, 0, 1},
 		},
 		{
 			typ:       ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
-			size:      align(align(3*4) + PtrSize + 2),
-			argsize:   align(3*4) + PtrSize + 2,
-			retOffset: align(align(3*4) + PtrSize + 2),
+			size:      align(align(3*4) + goarch.PtrSize + 2),
+			argsize:   align(3*4) + goarch.PtrSize + 2,
+			retOffset: align(align(3*4) + goarch.PtrSize + 2),
 			stack:     r,
 			gc:        r,
 		},
 		{
 			typ:       ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(),
-			size:      4 * PtrSize,
-			argsize:   4 * PtrSize,
-			retOffset: 4 * PtrSize,
+			size:      4 * goarch.PtrSize,
+			argsize:   4 * goarch.PtrSize,
+			retOffset: 4 * goarch.PtrSize,
 			stack:     []byte{1, 0, 1, 1},
 			gc:        []byte{1, 0, 1, 1},
 		},
 		{
 			typ:       ValueOf(func(a S) {}).Type(),
-			size:      4 * PtrSize,
-			argsize:   4 * PtrSize,
-			retOffset: 4 * PtrSize,
+			size:      4 * goarch.PtrSize,
+			argsize:   4 * goarch.PtrSize,
+			retOffset: 4 * goarch.PtrSize,
 			stack:     []byte{0, 0, 1, 1},
 			gc:        []byte{0, 0, 1, 1},
 		},
 		{
 			rcvr:      ValueOf((*byte)(nil)).Type(),
 			typ:       ValueOf(func(a uintptr, b *int) {}).Type(),
-			size:      3 * PtrSize,
-			argsize:   3 * PtrSize,
-			retOffset: 3 * PtrSize,
+			size:      3 * goarch.PtrSize,
+			argsize:   3 * goarch.PtrSize,
+			retOffset: 3 * goarch.PtrSize,
 			stack:     []byte{1, 0, 1},
 			gc:        []byte{1, 0, 1},
 		},
 		{
 			typ:       ValueOf(func(a uintptr) {}).Type(),
-			size:      PtrSize,
-			argsize:   PtrSize,
-			retOffset: PtrSize,
+			size:      goarch.PtrSize,
+			argsize:   goarch.PtrSize,
+			retOffset: goarch.PtrSize,
 			stack:     []byte{},
 			gc:        []byte{},
 		},
 		{
 			typ:       ValueOf(func() uintptr { return 0 }).Type(),
-			size:      PtrSize,
+			size:      goarch.PtrSize,
 			argsize:   0,
 			retOffset: 0,
 			stack:     []byte{},
@@ -6539,9 +6549,9 @@ func TestFuncLayout(t *testing.T) {
 		{
 			rcvr:      ValueOf(uintptr(0)).Type(),
 			typ:       ValueOf(func(a uintptr) {}).Type(),
-			size:      2 * PtrSize,
-			argsize:   2 * PtrSize,
-			retOffset: 2 * PtrSize,
+			size:      2 * goarch.PtrSize,
+			argsize:   2 * goarch.PtrSize,
+			retOffset: 2 * goarch.PtrSize,
 			stack:     []byte{1},
 			gc:        []byte{1},
 			// Note: this one is tricky, as the receiver is not a pointer. But we
@@ -6747,7 +6757,7 @@ func TestGCBits(t *testing.T) {
 	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
 	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
 
-	hdr := make([]byte, 8/PtrSize)
+	hdr := make([]byte, 8/goarch.PtrSize)
 
 	verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) {
 		verifyGCBits(t, MapBucketOf(k, e), want)
@@ -6763,7 +6773,7 @@ func TestGCBits(t *testing.T) {
 		join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1)))
 	verifyMapBucket(t, Tint64, Tptr,
 		map[int64]Xptr(nil),
-		join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), lit(1)))
+		join(hdr, rep(8, rep(8/goarch.PtrSize, lit(0))), rep(8, lit(1)), lit(1)))
 	verifyMapBucket(t,
 		Tscalar, Tscalar,
 		map[Xscalar]Xscalar(nil),
@@ -6773,20 +6783,20 @@ func TestGCBits(t *testing.T) {
 		map[[2]Xscalarptr][3]Xptrscalar(nil),
 		join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1)))
 	verifyMapBucket(t,
-		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
-		map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
-		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
+		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
+		map[[64 / goarch.PtrSize]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
+		join(hdr, rep(8*64/goarch.PtrSize, lit(0, 1)), rep(8*64/goarch.PtrSize, lit(1, 0)), lit(1)))
 	verifyMapBucket(t,
-		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
-		map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
-		join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
+		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
+		map[[64/goarch.PtrSize + 1]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
+		join(hdr, rep(8, lit(1)), rep(8*64/goarch.PtrSize, lit(1, 0)), lit(1)))
 	verifyMapBucket(t,
-		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
-		map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
-		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
+		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
+		map[[64 / goarch.PtrSize]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
+		join(hdr, rep(8*64/goarch.PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
 	verifyMapBucket(t,
-		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
-		map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
+		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
+		map[[64/goarch.PtrSize + 1]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
 		join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1)))
 }
 
@@ -6942,19 +6952,6 @@ func TestExported(t *testing.T) {
 	}
 }
 
-type embed struct {
-	EmbedWithUnexpMeth
-}
-
-func TestNameBytesAreAligned(t *testing.T) {
-	typ := TypeOf(embed{})
-	b := FirstMethodNameBytes(typ)
-	v := uintptr(unsafe.Pointer(b))
-	if v%unsafe.Alignof((*byte)(nil)) != 0 {
-		t.Errorf("reflect.name.bytes pointer is not aligned: %x", v)
-	}
-}
-
 func TestTypeStrings(t *testing.T) {
 	type stringTest struct {
 		typ  Type
diff --git a/src/reflect/asm_amd64.s b/src/reflect/asm_amd64.s
index facf07516d8..d21d498063b 100644
--- a/src/reflect/asm_amd64.s
+++ b/src/reflect/asm_amd64.s
@@ -24,15 +24,13 @@
 // See the comment on the declaration of makeFuncStub in makefunc.go
 // for more details.
 // No arg size here; runtime pulls arg map out of the func value.
-// makeFuncStub must be ABIInternal because it is placed directly
-// in function values.
 // This frame contains two locals. See the comment above LOCAL_RETVALID.
-TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$312
+TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$312
 	NO_LOCAL_POINTERS
 	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
 	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
 	LEAQ	LOCAL_REGARGS(SP), R12
-	CALL	runtime·spillArgs(SB)
+	CALL	runtime·spillArgs(SB)
 	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
 	MOVQ	DX, 0(SP)
 	MOVQ	R12, 8(SP)
@@ -48,22 +46,20 @@ TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$312
 	MOVQ	AX, 24(SP)
 	CALL	·callReflect(SB)
 	LEAQ	LOCAL_REGARGS(SP), R12
-	CALL	runtime·unspillArgs(SB)
+	CALL	runtime·unspillArgs(SB)
 	RET
 
 // methodValueCall is the code half of the function returned by makeMethodValue.
 // See the comment on the declaration of methodValueCall in makefunc.go
 // for more details.
 // No arg size here; runtime pulls arg map out of the func value.
-// methodValueCall must be ABIInternal because it is placed directly
-// in function values.
 // This frame contains two locals. See the comment above LOCAL_RETVALID.
-TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$312
+TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$312
 	NO_LOCAL_POINTERS
 	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
 	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
 	LEAQ	LOCAL_REGARGS(SP), R12
-	CALL	runtime·spillArgs(SB)
+	CALL	runtime·spillArgs(SB)
 	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
 	MOVQ	DX, 0(SP)
 	MOVQ	R12, 8(SP)
@@ -79,5 +75,5 @@ TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$312
 	MOVQ	AX, 24(SP)
 	CALL	·callMethod(SB)
 	LEAQ	LOCAL_REGARGS(SP), R12
-	CALL	runtime·unspillArgs(SB)
+	CALL	runtime·unspillArgs(SB)
 	RET
diff --git a/src/reflect/asm_arm64.s b/src/reflect/asm_arm64.s
index 5fe88e27e40..5b9b3573fa2 100644
--- a/src/reflect/asm_arm64.s
+++ b/src/reflect/asm_arm64.s
@@ -5,34 +5,75 @@
 #include "textflag.h"
 #include "funcdata.h"
 
+// The frames of each of the two functions below contain two locals, at offsets
+// that are known to the runtime.
+//
+// The first local is a bool called retValid with a whole pointer-word reserved
+// for it on the stack. The purpose of this word is so that the runtime knows
+// whether the stack-allocated return space contains valid values for stack
+// scanning.
+//
+// The second local is an abi.RegArgs value whose offset is also known to the
+// runtime, so that a stack map for it can be constructed, since it contains
+// pointers visible to the GC.
+#define LOCAL_RETVALID 40
+#define LOCAL_REGARGS 48
+
+// The frame size of the functions below is
+// 32 (args of callReflect) + 8 (bool + padding) + 392 (abi.RegArgs) = 432.
+
 // makeFuncStub is the code half of the function returned by MakeFunc.
 // See the comment on the declaration of makeFuncStub in makefunc.go
 // for more details.
 // No arg size here, runtime pulls arg map out of the func value.
-TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$40
+TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$432
 	NO_LOCAL_POINTERS
+	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
+	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
+	ADD	$LOCAL_REGARGS, RSP, R20
+	CALL	runtime·spillArgs(SB)
+	MOVD	R26, 32(RSP) // outside of moveMakeFuncArgPtrs's arg area
+	MOVD	R26, 8(RSP)
+	MOVD	R20, 16(RSP)
+	CALL	·moveMakeFuncArgPtrs(SB)
+	MOVD	32(RSP), R26
 	MOVD	R26, 8(RSP)
 	MOVD	$argframe+0(FP), R3
 	MOVD	R3, 16(RSP)
-	MOVB	$0, 40(RSP)
-	ADD	$40, RSP, R3
+	MOVB	$0, LOCAL_RETVALID(RSP)
+	ADD	$LOCAL_RETVALID, RSP, R3
 	MOVD	R3, 24(RSP)
-	MOVD	$0, 32(RSP)
-	BL	·callReflect(SB)
+	ADD	$LOCAL_REGARGS, RSP, R3
+	MOVD	R3, 32(RSP)
+	CALL	·callReflect(SB)
+	ADD	$LOCAL_REGARGS, RSP, R20
+	CALL	runtime·unspillArgs(SB)
 	RET
 
 // methodValueCall is the code half of the function returned by makeMethodValue.
 // See the comment on the declaration of methodValueCall in makefunc.go
 // for more details.
 // No arg size here; runtime pulls arg map out of the func value.
-TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$40
+TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$432
 	NO_LOCAL_POINTERS
+	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
+	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
+	ADD	$LOCAL_REGARGS, RSP, R20
+	CALL	runtime·spillArgs(SB)
+	MOVD	R26, 32(RSP) // outside of moveMakeFuncArgPtrs's arg area
+	MOVD	R26, 8(RSP)
+	MOVD	R20, 16(RSP)
+	CALL	·moveMakeFuncArgPtrs(SB)
+	MOVD	32(RSP), R26
 	MOVD	R26, 8(RSP)
 	MOVD	$argframe+0(FP), R3
 	MOVD	R3, 16(RSP)
-	MOVB	$0, 40(RSP)
-	ADD	$40, RSP, R3
+	MOVB	$0, LOCAL_RETVALID(RSP)
+	ADD	$LOCAL_RETVALID, RSP, R3
 	MOVD	R3, 24(RSP)
-	MOVD	$0, 32(RSP)
-	BL	·callMethod(SB)
+	ADD	$LOCAL_REGARGS, RSP, R3
+	MOVD	R3, 32(RSP)
+	CALL	·callMethod(SB)
+	ADD	$LOCAL_REGARGS, RSP, R20
+	CALL	runtime·unspillArgs(SB)
 	RET
diff --git a/src/reflect/asm_mips64x.s b/src/reflect/asm_mips64x.s
index ae661262cb4..8d01c5fb7ed 100644
--- a/src/reflect/asm_mips64x.s
+++ b/src/reflect/asm_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
diff --git a/src/reflect/asm_mipsx.s b/src/reflect/asm_mipsx.s
index 47fef844a19..6ea82331084 100644
--- a/src/reflect/asm_mipsx.s
+++ b/src/reflect/asm_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/reflect/asm_ppc64x.s b/src/reflect/asm_ppc64x.s
index 010811c31a5..d955e4110f8 100644
--- a/src/reflect/asm_ppc64x.s
+++ b/src/reflect/asm_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/reflect/export_test.go b/src/reflect/export_test.go
index b6830a98020..01749e30d85 100644
--- a/src/reflect/export_test.go
+++ b/src/reflect/export_test.go
@@ -5,6 +5,7 @@
 package reflect
 
 import (
+	"internal/goarch"
 	"sync"
 	"unsafe"
 )
@@ -22,8 +23,6 @@ func IsRO(v Value) bool {
 
 var CallGC = &callGC
 
-const PtrSize = ptrSize
-
 // FuncLayout calls funcLayout and returns a subset of the results for testing.
 //
 // Bitmaps like stack, gc, inReg, and outReg are expanded such that each bit
@@ -65,7 +64,7 @@ func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr,
 	// Expand frame type's GC bitmap into byte-map.
 	ptrs = ft.ptrdata != 0
 	if ptrs {
-		nptrs := ft.ptrdata / ptrSize
+		nptrs := ft.ptrdata / goarch.PtrSize
 		gcdata := ft.gcSlice(0, (nptrs+7)/8)
 		for i := uintptr(0); i < nptrs; i++ {
 			gc = append(gc, gcdata[i/8]>>(i%8)&1)
diff --git a/src/reflect/makefunc.go b/src/reflect/makefunc.go
index d53e68a3594..588be8bcc15 100644
--- a/src/reflect/makefunc.go
+++ b/src/reflect/makefunc.go
@@ -52,11 +52,7 @@ func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value {
 	t := typ.common()
 	ftyp := (*funcType)(unsafe.Pointer(t))
 
-	// Indirect Go func value (dummy) to obtain
-	// actual code address. (A Go func value is a pointer
-	// to a C function pointer. https://golang.org/s/go11func.)
-	dummy := makeFuncStub
-	code := **(**uintptr)(unsafe.Pointer(&dummy))
+	code := abi.FuncPCABI0(makeFuncStub)
 
 	// makeFuncImpl contains a stack map for use by the runtime
 	_, _, abi := funcLayout(ftyp, nil)
@@ -111,11 +107,7 @@ func makeMethodValue(op string, v Value) Value {
 	// v.Type returns the actual type of the method value.
 	ftyp := (*funcType)(unsafe.Pointer(v.Type().(*rtype)))
 
-	// Indirect Go func value (dummy) to obtain
-	// actual code address. (A Go func value is a pointer
-	// to a C function pointer. https://golang.org/s/go11func.)
-	dummy := methodValueCall
-	code := **(**uintptr)(unsafe.Pointer(&dummy))
+	code := abi.FuncPCABI0(methodValueCall)
 
 	// methodValue contains a stack map for use by the runtime
 	_, _, abi := funcLayout(ftyp, nil)
diff --git a/src/reflect/swapper.go b/src/reflect/swapper.go
index 0cf40666b1e..67b7fbe59be 100644
--- a/src/reflect/swapper.go
+++ b/src/reflect/swapper.go
@@ -5,6 +5,7 @@
 package reflect
 
 import (
+	"internal/goarch"
 	"internal/unsafeheader"
 	"unsafe"
 )
@@ -36,7 +37,7 @@ func Swapper(slice interface{}) func(i, j int) {
 
 	// Some common & small cases, without using memmove:
 	if hasPtr {
-		if size == ptrSize {
+		if size == goarch.PtrSize {
 			ps := *(*[]unsafe.Pointer)(v.ptr)
 			return func(i, j int) { ps[i], ps[j] = ps[j], ps[i] }
 		}
diff --git a/src/reflect/type.go b/src/reflect/type.go
index 9727bfe467c..278426da09e 100644
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -16,6 +16,7 @@
 package reflect
 
 import (
+	"internal/goarch"
 	"internal/unsafeheader"
 	"strconv"
 	"sync"
@@ -107,10 +108,14 @@ type Type interface {
 
 	// ConvertibleTo reports whether a value of the type is convertible to type u.
 	// Even if ConvertibleTo returns true, the conversion may still panic.
+	// For example, a slice of type []T is convertible to *[N]T,
+	// but the conversion will panic if its length is less than N.
 	ConvertibleTo(u Type) bool
 
 	// Comparable reports whether values of this type are comparable.
 	// Even if Comparable returns true, the comparison may still panic.
+	// For example, values of interface type are comparable,
+	// but the comparison will panic if their dynamic type is not comparable.
 	Comparable() bool
 
 	// Methods applicable only to some types, depending on Kind.
@@ -224,7 +229,7 @@ type Type interface {
 // See https://golang.org/issue/4876 for more details.
 
 /*
- * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go).
+ * These data structures are known to the compiler (../../cmd/internal/reflectdata/reflect.go).
  * A few are known to ../runtime/type.go to convey to debuggers.
  * They are also known to ../runtime/type.go.
  */
@@ -267,7 +272,7 @@ const (
 // available in the memory directly following the rtype value.
 //
 // tflag values must be kept in sync with copies in:
-//	cmd/compile/internal/gc/reflect.go
+//	cmd/compile/internal/reflectdata/reflect.go
 //	cmd/link/internal/ld/decodesym.go
 //	runtime/type.go
 type tflag uint8
@@ -450,14 +455,11 @@ type structType struct {
 //	1<<1 tag data follows the name
 //	1<<2 pkgPath nameOff follows the name and tag
 //
-// The next two bytes are the data length:
+// Following that, there is a varint-encoded length of the name,
+// followed by the name itself.
 //
-//	 l := uint16(data[1])<<8 | uint16(data[2])
-//
-// Bytes [3:3+l] are the string data.
-//
-// If tag data follows then bytes 3+l and 3+l+1 are the tag length,
-// with the data following.
+// If tag data is present, it also has a varint-encoded length
+// followed by the tag itself.
 //
 // If the import path follows, then 4 bytes at the end of
 // the data form a nameOff. The import path is only set for concrete
@@ -465,6 +467,13 @@ type structType struct {
 //
 // If a name starts with "*", then the exported bit represents
 // whether the pointed to type is exported.
+//
+// Note: this encoding must match here and in:
+//   cmd/compile/internal/reflectdata/reflect.go
+//   runtime/type.go
+//   internal/reflectlite/type.go
+//   cmd/link/internal/ld/decodesym.go
+
 type name struct {
 	bytes *byte
 }
@@ -477,49 +486,70 @@ func (n name) isExported() bool {
 	return (*n.bytes)&(1<<0) != 0
 }
 
-func (n name) nameLen() int {
-	return int(uint16(*n.data(1, "name len field"))<<8 | uint16(*n.data(2, "name len field")))
+func (n name) hasTag() bool {
+	return (*n.bytes)&(1<<1) != 0
 }
 
-func (n name) tagLen() int {
-	if *n.data(0, "name flag field")&(1<<1) == 0 {
-		return 0
+// readVarint parses a varint as encoded by encoding/binary.
+// It returns the number of encoded bytes and the encoded value.
+func (n name) readVarint(off int) (int, int) {
+	v := 0
+	for i := 0; ; i++ {
+		x := *n.data(off+i, "read varint")
+		v += int(x&0x7f) << (7 * i)
+		if x&0x80 == 0 {
+			return i + 1, v
+		}
+	}
+}
+
+// writeVarint writes n to buf in varint form. Returns the
+// number of bytes written. n must be nonnegative.
+// Writes at most 10 bytes.
+func writeVarint(buf []byte, n int) int {
+	for i := 0; ; i++ {
+		b := byte(n & 0x7f)
+		n >>= 7
+		if n == 0 {
+			buf[i] = b
+			return i + 1
+		}
+		buf[i] = b | 0x80
 	}
-	off := 3 + n.nameLen()
-	return int(uint16(*n.data(off, "name taglen field"))<<8 | uint16(*n.data(off+1, "name taglen field")))
 }
 
 func (n name) name() (s string) {
 	if n.bytes == nil {
 		return
 	}
-	b := (*[4]byte)(unsafe.Pointer(n.bytes))
-
+	i, l := n.readVarint(1)
 	hdr := (*unsafeheader.String)(unsafe.Pointer(&s))
-	hdr.Data = unsafe.Pointer(&b[3])
-	hdr.Len = int(b[1])<<8 | int(b[2])
-	return s
+	hdr.Data = unsafe.Pointer(n.data(1+i, "non-empty string"))
+	hdr.Len = l
+	return
 }
 
 func (n name) tag() (s string) {
-	tl := n.tagLen()
-	if tl == 0 {
+	if !n.hasTag() {
 		return ""
 	}
-	nl := n.nameLen()
+	i, l := n.readVarint(1)
+	i2, l2 := n.readVarint(1 + i + l)
 	hdr := (*unsafeheader.String)(unsafe.Pointer(&s))
-	hdr.Data = unsafe.Pointer(n.data(3+nl+2, "non-empty string"))
-	hdr.Len = tl
-	return s
+	hdr.Data = unsafe.Pointer(n.data(1+i+l+i2, "non-empty string"))
+	hdr.Len = l2
+	return
 }
 
 func (n name) pkgPath() string {
 	if n.bytes == nil || *n.data(0, "name flag field")&(1<<2) == 0 {
 		return ""
 	}
-	off := 3 + n.nameLen()
-	if tl := n.tagLen(); tl > 0 {
-		off += 2 + tl
+	i, l := n.readVarint(1)
+	off := 1 + i + l
+	if n.hasTag() {
+		i2, l2 := n.readVarint(off)
+		off += i2 + l2
 	}
 	var nameOff int32
 	// Note that this field may not be aligned in memory,
@@ -530,33 +560,35 @@ func (n name) pkgPath() string {
 }
 
 func newName(n, tag string, exported bool) name {
-	if len(n) > 1<<16-1 {
-		panic("reflect.nameFrom: name too long: " + n)
+	if len(n) >= 1<<29 {
+		panic("reflect.nameFrom: name too long: " + n[:1024] + "...")
 	}
-	if len(tag) > 1<<16-1 {
-		panic("reflect.nameFrom: tag too long: " + tag)
+	if len(tag) >= 1<<29 {
+		panic("reflect.nameFrom: tag too long: " + tag[:1024] + "...")
 	}
+	var nameLen [10]byte
+	var tagLen [10]byte
+	nameLenLen := writeVarint(nameLen[:], len(n))
+	tagLenLen := writeVarint(tagLen[:], len(tag))
 
 	var bits byte
-	l := 1 + 2 + len(n)
+	l := 1 + nameLenLen + len(n)
 	if exported {
 		bits |= 1 << 0
 	}
 	if len(tag) > 0 {
-		l += 2 + len(tag)
+		l += tagLenLen + len(tag)
 		bits |= 1 << 1
 	}
 
 	b := make([]byte, l)
 	b[0] = bits
-	b[1] = uint8(len(n) >> 8)
-	b[2] = uint8(len(n))
-	copy(b[3:], n)
+	copy(b[1:], nameLen[:nameLenLen])
+	copy(b[1+nameLenLen:], n)
 	if len(tag) > 0 {
-		tb := b[3+len(n):]
-		tb[0] = uint8(len(tag) >> 8)
-		tb[1] = uint8(len(tag))
-		copy(tb[2:], tag)
+		tb := b[1+nameLenLen+len(n):]
+		copy(tb, tagLen[:tagLenLen])
+		copy(tb[tagLenLen:], tag)
 	}
 
 	return name{bytes: &b[0]}
@@ -1879,7 +1911,7 @@ func MapOf(key, elem Type) Type {
 
 	// Make a map type.
 	// Note: flag values must match those used in the TMAP case
-	// in ../cmd/compile/internal/gc/reflect.go:writeType.
+	// in ../cmd/compile/internal/reflectdata/reflect.go:writeType.
 	var imap interface{} = (map[unsafe.Pointer]unsafe.Pointer)(nil)
 	mt := **(**mapType)(unsafe.Pointer(&imap))
 	mt.str = resolveReflectName(newName(s, "", false))
@@ -1893,13 +1925,13 @@ func MapOf(key, elem Type) Type {
 	}
 	mt.flags = 0
 	if ktyp.size > maxKeySize {
-		mt.keysize = uint8(ptrSize)
+		mt.keysize = uint8(goarch.PtrSize)
 		mt.flags |= 1 // indirect key
 	} else {
 		mt.keysize = uint8(ktyp.size)
 	}
 	if etyp.size > maxValSize {
-		mt.valuesize = uint8(ptrSize)
+		mt.valuesize = uint8(goarch.PtrSize)
 		mt.flags |= 2 // indirect value
 	} else {
 		mt.valuesize = uint8(etyp.size)
@@ -2200,31 +2232,31 @@ func bucketOf(ktyp, etyp *rtype) *rtype {
 	var ptrdata uintptr
 	var overflowPad uintptr
 
-	size := bucketSize*(1+ktyp.size+etyp.size) + overflowPad + ptrSize
+	size := bucketSize*(1+ktyp.size+etyp.size) + overflowPad + goarch.PtrSize
 	if size&uintptr(ktyp.align-1) != 0 || size&uintptr(etyp.align-1) != 0 {
 		panic("reflect: bad size computation in MapOf")
 	}
 
 	if ktyp.ptrdata != 0 || etyp.ptrdata != 0 {
-		nptr := (bucketSize*(1+ktyp.size+etyp.size) + ptrSize) / ptrSize
+		nptr := (bucketSize*(1+ktyp.size+etyp.size) + goarch.PtrSize) / goarch.PtrSize
 		mask := make([]byte, (nptr+7)/8)
-		base := bucketSize / ptrSize
+		base := bucketSize / goarch.PtrSize
 
 		if ktyp.ptrdata != 0 {
 			emitGCMask(mask, base, ktyp, bucketSize)
 		}
-		base += bucketSize * ktyp.size / ptrSize
+		base += bucketSize * ktyp.size / goarch.PtrSize
 
 		if etyp.ptrdata != 0 {
 			emitGCMask(mask, base, etyp, bucketSize)
 		}
-		base += bucketSize * etyp.size / ptrSize
-		base += overflowPad / ptrSize
+		base += bucketSize * etyp.size / goarch.PtrSize
+		base += overflowPad / goarch.PtrSize
 
 		word := base
 		mask[word/8] |= 1 << (word % 8)
 		gcdata = &mask[0]
-		ptrdata = (word + 1) * ptrSize
+		ptrdata = (word + 1) * goarch.PtrSize
 
 		// overflow word must be last
 		if ptrdata != size {
@@ -2233,7 +2265,7 @@ func bucketOf(ktyp, etyp *rtype) *rtype {
 	}
 
 	b := &rtype{
-		align:   ptrSize,
+		align:   goarch.PtrSize,
 		size:    size,
 		kind:    uint8(Struct),
 		ptrdata: ptrdata,
@@ -2257,8 +2289,8 @@ func emitGCMask(out []byte, base uintptr, typ *rtype, n uintptr) {
 	if typ.kind&kindGCProg != 0 {
 		panic("reflect: unexpected GC program")
 	}
-	ptrs := typ.ptrdata / ptrSize
-	words := typ.size / ptrSize
+	ptrs := typ.ptrdata / goarch.PtrSize
+	words := typ.size / goarch.PtrSize
 	mask := typ.gcSlice(0, (ptrs+7)/8)
 	for j := uintptr(0); j < ptrs; j++ {
 		if (mask[j/8]>>(j%8))&1 != 0 {
@@ -2281,7 +2313,7 @@ func appendGCProg(dst []byte, typ *rtype) []byte {
 	}
 
 	// Element is small with pointer mask; use as literal bits.
-	ptrs := typ.ptrdata / ptrSize
+	ptrs := typ.ptrdata / goarch.PtrSize
 	mask := typ.gcSlice(0, (ptrs+7)/8)
 
 	// Emit 120-bit chunks of full bytes (max is 127 but we avoid using partial bytes).
@@ -2570,7 +2602,7 @@ func StructOf(fields []StructField) Type {
 		hash = fnv1(hash, byte(ft.hash>>24), byte(ft.hash>>16), byte(ft.hash>>8), byte(ft.hash))
 
 		repr = append(repr, (" " + ft.String())...)
-		if f.name.tagLen() > 0 {
+		if f.name.hasTag() {
 			hash = fnv1(hash, []byte(f.name.tag())...)
 			repr = append(repr, (" " + strconv.Quote(f.name.tag()))...)
 		}
@@ -2728,7 +2760,7 @@ func StructOf(fields []StructField) Type {
 			}
 			// Pad to start of this field with zeros.
 			if ft.offset() > off {
-				n := (ft.offset() - off) / ptrSize
+				n := (ft.offset() - off) / goarch.PtrSize
 				prog = append(prog, 0x01, 0x00) // emit a 0 bit
 				if n > 1 {
 					prog = append(prog, 0x81)      // repeat previous bit
@@ -2810,7 +2842,7 @@ func runtimeStructField(field StructField) (structField, string) {
 
 // typeptrdata returns the length in bytes of the prefix of t
 // containing pointer data. Anything after this offset is scalar data.
-// keep in sync with ../cmd/compile/internal/gc/reflect.go
+// keep in sync with ../cmd/compile/internal/reflectdata/reflect.go
 func typeptrdata(t *rtype) uintptr {
 	switch t.Kind() {
 	case Struct:
@@ -2834,7 +2866,7 @@ func typeptrdata(t *rtype) uintptr {
 	}
 }
 
-// See cmd/compile/internal/gc/reflect.go for derivation of constant.
+// See cmd/compile/internal/reflectdata/reflect.go for derivation of constant.
 const maxPtrmaskBytes = 2048
 
 // ArrayOf returns the array type with the given length and element type.
@@ -2905,11 +2937,11 @@ func ArrayOf(length int, elem Type) Type {
 		array.gcdata = typ.gcdata
 		array.ptrdata = typ.ptrdata
 
-	case typ.kind&kindGCProg == 0 && array.size <= maxPtrmaskBytes*8*ptrSize:
+	case typ.kind&kindGCProg == 0 && array.size <= maxPtrmaskBytes*8*goarch.PtrSize:
 		// Element is small with pointer mask; array is still small.
 		// Create direct pointer mask by turning each 1 bit in elem
 		// into length 1 bits in larger mask.
-		mask := make([]byte, (array.ptrdata/ptrSize+7)/8)
+		mask := make([]byte, (array.ptrdata/goarch.PtrSize+7)/8)
 		emitGCMask(mask, 0, typ, array.len)
 		array.gcdata = &mask[0]
 
@@ -2919,8 +2951,8 @@ func ArrayOf(length int, elem Type) Type {
 		prog := []byte{0, 0, 0, 0} // will be length of prog
 		prog = appendGCProg(prog, typ)
 		// Pad from ptrdata to size.
-		elemPtrs := typ.ptrdata / ptrSize
-		elemWords := typ.size / ptrSize
+		elemPtrs := typ.ptrdata / goarch.PtrSize
+		elemWords := typ.size / goarch.PtrSize
 		if elemPtrs < elemWords {
 			// Emit literal 0 bit, then repeat as needed.
 			prog = append(prog, 0x01, 0x00)
@@ -3032,13 +3064,13 @@ func funcLayout(t *funcType, rcvr *rtype) (frametype *rtype, framePool *sync.Poo
 
 	// build dummy rtype holding gc program
 	x := &rtype{
-		align: ptrSize,
+		align: goarch.PtrSize,
 		// Don't add spill space here; it's only necessary in
 		// reflectcall's frame, not in the allocated frame.
 		// TODO(mknyszek): Remove this comment when register
 		// spill space in the frame is no longer required.
-		size:    align(abi.retOffset+abi.ret.stackBytes, ptrSize),
-		ptrdata: uintptr(abi.stackPtrs.n) * ptrSize,
+		size:    align(abi.retOffset+abi.ret.stackBytes, goarch.PtrSize),
+		ptrdata: uintptr(abi.stackPtrs.n) * goarch.PtrSize,
 	}
 	if abi.stackPtrs.n > 0 {
 		x.gcdata = &abi.stackPtrs.data[0]
@@ -3093,14 +3125,14 @@ func addTypeBits(bv *bitVector, offset uintptr, t *rtype) {
 	switch Kind(t.kind & kindMask) {
 	case Chan, Func, Map, Ptr, Slice, String, UnsafePointer:
 		// 1 pointer at start of representation
-		for bv.n < uint32(offset/uintptr(ptrSize)) {
+		for bv.n < uint32(offset/uintptr(goarch.PtrSize)) {
 			bv.append(0)
 		}
 		bv.append(1)
 
 	case Interface:
 		// 2 pointers
-		for bv.n < uint32(offset/uintptr(ptrSize)) {
+		for bv.n < uint32(offset/uintptr(goarch.PtrSize)) {
 			bv.append(0)
 		}
 		bv.append(1)
diff --git a/src/reflect/value.go b/src/reflect/value.go
index 418dff781f4..b4b2d2e38b8 100644
--- a/src/reflect/value.go
+++ b/src/reflect/value.go
@@ -6,6 +6,7 @@ package reflect
 
 import (
 	"internal/abi"
+	"internal/goarch"
 	"internal/itoa"
 	"internal/unsafeheader"
 	"math"
@@ -13,8 +14,6 @@ import (
 	"unsafe"
 )
 
-const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const
-
 // Value is the reflection interface to a Go value.
 //
 // Not all methods apply to all kinds of values. Restrictions,
@@ -94,7 +93,7 @@ func (f flag) ro() flag {
 // v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer
 // if v.Kind() == Ptr, the base type must not be go:notinheap.
 func (v Value) pointer() unsafe.Pointer {
-	if v.typ.size != ptrSize || !v.typ.pointers() {
+	if v.typ.size != goarch.PtrSize || !v.typ.pointers() {
 		panic("can't call pointer on a non-pointer Value")
 	}
 	if v.flag&flagIndir != 0 {
@@ -533,7 +532,7 @@ func (v Value) call(op string, in []Value) []Value {
 	}
 	// TODO(mknyszek): Remove this when we no longer have
 	// caller reserved spill space.
-	frameSize = align(frameSize, ptrSize)
+	frameSize = align(frameSize, goarch.PtrSize)
 	frameSize += abi.spill
 
 	// Mark pointers in registers for the return path.
@@ -952,25 +951,44 @@ func callMethod(ctxt *methodValue, frame unsafe.Pointer, retValid *bool, regs *a
 			continue
 		}
 
-		// There are three cases to handle in translating each
+		// There are four cases to handle in translating each
 		// argument:
 		// 1. Stack -> stack translation.
-		// 2. Registers -> stack translation.
-		// 3. Registers -> registers translation.
-		// The fourth cases can't happen, because a method value
-		// call uses strictly fewer registers than a method call.
+		// 2. Stack -> registers translation.
+		// 3. Registers -> stack translation.
+		// 4. Registers -> registers translation.
 
 		// If the value ABI passes the value on the stack,
 		// then the method ABI does too, because it has strictly
 		// fewer arguments. Simply copy between the two.
 		if vStep := valueSteps[0]; vStep.kind == abiStepStack {
 			mStep := methodSteps[0]
-			if mStep.kind != abiStepStack || vStep.size != mStep.size {
-				panic("method ABI and value ABI do not align")
+			// Handle stack -> stack translation.
+			if mStep.kind == abiStepStack {
+				if vStep.size != mStep.size {
+					panic("method ABI and value ABI do not align")
+				}
+				typedmemmove(t,
+					add(methodFrame, mStep.stkOff, "precomputed stack offset"),
+					add(valueFrame, vStep.stkOff, "precomputed stack offset"))
+				continue
+			}
+			// Handle stack -> register translation.
+			for _, mStep := range methodSteps {
+				from := add(valueFrame, vStep.stkOff+mStep.offset, "precomputed stack offset")
+				switch mStep.kind {
+				case abiStepPointer:
+					// Do the pointer copy directly so we get a write barrier.
+					methodRegs.Ptrs[mStep.ireg] = *(*unsafe.Pointer)(from)
+					fallthrough // We need to make sure this ends up in Ints, too.
+				case abiStepIntReg:
+					memmove(methodRegs.IntRegArgAddr(mStep.ireg, mStep.size), from, mStep.size)
+				case abiStepFloatReg:
+					memmove(methodRegs.FloatRegArgAddr(mStep.freg, mStep.size), from, mStep.size)
+				default:
+					panic("unexpected method step")
+				}
 			}
-			typedmemmove(t,
-				add(methodFrame, mStep.stkOff, "precomputed stack offset"),
-				add(valueFrame, vStep.stkOff, "precomputed stack offset"))
 			continue
 		}
 		// Handle register -> stack translation.
@@ -982,9 +1000,9 @@ func callMethod(ctxt *methodValue, frame unsafe.Pointer, retValid *bool, regs *a
 					// Do the pointer copy directly so we get a write barrier.
 					*(*unsafe.Pointer)(to) = valueRegs.Ptrs[vStep.ireg]
 				case abiStepIntReg:
-					memmove(to, unsafe.Pointer(&valueRegs.Ints[vStep.ireg]), vStep.size)
+					memmove(to, valueRegs.IntRegArgAddr(vStep.ireg, vStep.size), vStep.size)
 				case abiStepFloatReg:
-					memmove(to, unsafe.Pointer(&valueRegs.Floats[vStep.freg]), vStep.size)
+					memmove(to, valueRegs.FloatRegArgAddr(vStep.freg, vStep.size), vStep.size)
 				default:
 					panic("unexpected value step")
 				}
@@ -1021,7 +1039,7 @@ func callMethod(ctxt *methodValue, frame unsafe.Pointer, retValid *bool, regs *a
 	methodFrameSize := methodFrameType.size
 	// TODO(mknyszek): Remove this when we no longer have
 	// caller reserved spill space.
-	methodFrameSize = align(methodFrameSize, ptrSize)
+	methodFrameSize = align(methodFrameSize, goarch.PtrSize)
 	methodFrameSize += methodABI.spill
 
 	// Mark pointers in registers for the return path.
@@ -1359,10 +1377,16 @@ func valueInterface(v Value, safe bool) interface{} {
 	return packEface(v)
 }
 
-// InterfaceData returns the interface v's value as a uintptr pair.
+// InterfaceData returns a pair of unspecified uintptr values.
 // It panics if v's Kind is not Interface.
+//
+// In earlier versions of Go, this function returned the interface's
+// value as a uintptr pair. As of Go 1.4, the implementation of
+// interface values precludes any defined use of InterfaceData.
+//
+// Deprecated: The memory representation of interface values is not
+// compatible with InterfaceData.
 func (v Value) InterfaceData() [2]uintptr {
-	// TODO: deprecate this
 	v.mustBe(Interface)
 	// We treat this as a read operation, so we allow
 	// it even for unexported data, because the caller
@@ -2783,6 +2807,26 @@ func (v Value) Convert(t Type) Value {
 	return op(v, t)
 }
 
+// CanConvert reports whether the value v can be converted to type t.
+// If v.CanConvert(t) returns true then v.Convert(t) will not panic.
+func (v Value) CanConvert(t Type) bool {
+	vt := v.Type()
+	if !vt.ConvertibleTo(t) {
+		return false
+	}
+	// Currently the only conversion that is OK in terms of type
+	// but that can panic depending on the value is converting
+	// from slice to pointer-to-array.
+	if vt.Kind() == Slice && t.Kind() == Ptr && t.Elem().Kind() == Array {
+		n := t.Elem().Len()
+		h := (*unsafeheader.Slice)(v.ptr)
+		if n > h.Len {
+			return false
+		}
+	}
+	return true
+}
+
 // convertOp returns the function to convert a value of type src
 // to a value of type dst. If the conversion is illegal, convertOp returns nil.
 func convertOp(dst, src *rtype) func(Value, Type) Value {
@@ -3045,7 +3089,7 @@ func cvtSliceArrayPtr(v Value, t Type) Value {
 	n := t.Elem().Len()
 	h := (*unsafeheader.Slice)(v.ptr)
 	if n > h.Len {
-		panic("reflect: cannot convert slice with length " + itoa.Itoa(h.Len) + " to array pointer with length " + itoa.Itoa(n))
+		panic("reflect: cannot convert slice with length " + itoa.Itoa(h.Len) + " to pointer to array with length " + itoa.Itoa(n))
 	}
 	return Value{t.common(), h.Data, v.flag&^(flagIndir|flagAddr|flagKindMask) | flag(Ptr)}
 }
diff --git a/src/reflect/visiblefields.go b/src/reflect/visiblefields.go
index c068979dcc8..1a2b53570be 100644
--- a/src/reflect/visiblefields.go
+++ b/src/reflect/visiblefields.go
@@ -1,3 +1,7 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package reflect
 
 // VisibleFields returns all the visible fields in t, which must be a
diff --git a/src/reflect/visiblefields_test.go b/src/reflect/visiblefields_test.go
index 2688b63091a..915bbee867c 100644
--- a/src/reflect/visiblefields_test.go
+++ b/src/reflect/visiblefields_test.go
@@ -1,3 +1,7 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package reflect_test
 
 import (
diff --git a/src/regexp/find_test.go b/src/regexp/find_test.go
index 87c49b074fa..64c2239d905 100644
--- a/src/regexp/find_test.go
+++ b/src/regexp/find_test.go
@@ -97,6 +97,7 @@ var findTests = []FindTest{
 	{`\B`, "xx", build(1, 1, 1)},
 	{`\B`, "x y", nil},
 	{`\B`, "xx yy", build(2, 1, 1, 4, 4)},
+	{`(|a)*`, "aa", build(3, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2)},
 
 	// RE2 tests
 	{`[^\S\s]`, "abcd", nil},
diff --git a/src/regexp/onepass_test.go b/src/regexp/onepass_test.go
index 32264d5f1ef..6a42eda391c 100644
--- a/src/regexp/onepass_test.go
+++ b/src/regexp/onepass_test.go
@@ -142,7 +142,7 @@ var onePassTests = []struct {
 	{`^(?:(a)|(?:a*))$`, false},
 	{`^(?:(?:(?:.(?:$))?))$`, true},
 	{`^abcd$`, true},
-	{`^(?:(?:a{0,})*?)$`, true},
+	{`^(?:(?:a{0,})*?)$`, false},
 	{`^(?:(?:a+)*)$`, true},
 	{`^(?:(?:a|(?:aa)))$`, true},
 	{`^(?:[^\s\S])$`, true},
diff --git a/src/regexp/syntax/compile.go b/src/regexp/syntax/compile.go
index 7524d628fe1..c9f9fa024bf 100644
--- a/src/regexp/syntax/compile.go
+++ b/src/regexp/syntax/compile.go
@@ -57,8 +57,9 @@ func (l1 patchList) append(p *Prog, l2 patchList) patchList {
 
 // A frag represents a compiled program fragment.
 type frag struct {
-	i   uint32    // index of first instruction
-	out patchList // where to record end instruction
+	i        uint32    // index of first instruction
+	out      patchList // where to record end instruction
+	nullable bool      // whether fragment can match empty string
 }
 
 type compiler struct {
@@ -159,7 +160,7 @@ func (c *compiler) compile(re *Regexp) frag {
 
 func (c *compiler) inst(op InstOp) frag {
 	// TODO: impose length limit
-	f := frag{i: uint32(len(c.p.Inst))}
+	f := frag{i: uint32(len(c.p.Inst)), nullable: true}
 	c.p.Inst = append(c.p.Inst, Inst{Op: op})
 	return f
 }
@@ -194,7 +195,7 @@ func (c *compiler) cat(f1, f2 frag) frag {
 	// TODO: elide nop
 
 	f1.out.patch(c.p, f2.i)
-	return frag{f1.i, f2.out}
+	return frag{f1.i, f2.out, f1.nullable && f2.nullable}
 }
 
 func (c *compiler) alt(f1, f2 frag) frag {
@@ -211,6 +212,7 @@ func (c *compiler) alt(f1, f2 frag) frag {
 	i.Out = f1.i
 	i.Arg = f2.i
 	f.out = f1.out.append(c.p, f2.out)
+	f.nullable = f1.nullable || f2.nullable
 	return f
 }
 
@@ -228,7 +230,12 @@ func (c *compiler) quest(f1 frag, nongreedy bool) frag {
 	return f
 }
 
-func (c *compiler) star(f1 frag, nongreedy bool) frag {
+// loop returns the fragment for the main loop of a plus or star.
+// For plus, it can be used after changing the entry to f1.i.
+// For star, it can be used directly when f1 can't match an empty string.
+// (When f1 can match an empty string, f1* must be implemented as (f1+)?
+// to get the priority match order correct.)
+func (c *compiler) loop(f1 frag, nongreedy bool) frag {
 	f := c.inst(InstAlt)
 	i := &c.p.Inst[f.i]
 	if nongreedy {
@@ -242,8 +249,17 @@ func (c *compiler) star(f1 frag, nongreedy bool) frag {
 	return f
 }
 
+func (c *compiler) star(f1 frag, nongreedy bool) frag {
+	if f1.nullable {
+		// Use (f1+)? to get priority match order correct.
+		// See golang.org/issue/46123.
+		return c.quest(c.plus(f1, nongreedy), nongreedy)
+	}
+	return c.loop(f1, nongreedy)
+}
+
 func (c *compiler) plus(f1 frag, nongreedy bool) frag {
-	return frag{f1.i, c.star(f1, nongreedy).out}
+	return frag{f1.i, c.loop(f1, nongreedy).out, f1.nullable}
 }
 
 func (c *compiler) empty(op EmptyOp) frag {
@@ -255,6 +271,7 @@ func (c *compiler) empty(op EmptyOp) frag {
 
 func (c *compiler) rune(r []rune, flags Flags) frag {
 	f := c.inst(InstRune)
+	f.nullable = false
 	i := &c.p.Inst[f.i]
 	i.Rune = r
 	flags &= FoldCase // only relevant flag is FoldCase
diff --git a/src/regexp/syntax/prog_test.go b/src/regexp/syntax/prog_test.go
index 50bfa3d4bef..5603aea2289 100644
--- a/src/regexp/syntax/prog_test.go
+++ b/src/regexp/syntax/prog_test.go
@@ -88,6 +88,21 @@ var compileTests = []struct {
   1*	empty 4 -> 2
   2	anynotnl -> 3
   3	match
+`},
+	{"(?:|a)+", `  0	fail
+  1	nop -> 4
+  2	rune1 "a" -> 4
+  3*	alt -> 1, 2
+  4	alt -> 3, 5
+  5	match
+`},
+	{"(?:|a)*", `  0	fail
+  1	nop -> 4
+  2	rune1 "a" -> 4
+  3	alt -> 1, 2
+  4	alt -> 3, 6
+  5*	alt -> 3, 6
+  6	match
 `},
 }
 
diff --git a/src/regexp/testdata/basic.dat b/src/regexp/testdata/basic.dat
index 7859290ba1d..1776b1ff96b 100644
--- a/src/regexp/testdata/basic.dat
+++ b/src/regexp/testdata/basic.dat
@@ -124,24 +124,20 @@ E	((a))			abc		(0,1)(0,1)(0,1)
 E	(a)b(c)			abc		(0,3)(0,1)(2,3)
 E	a+b+c			aabbabc		(4,7)
 E	a*			aaa		(0,3)
-#E	(a*)*			-		(0,0)(0,0)
-E	(a*)*			-		(0,0)(?,?)	RE2/Go
+E	(a*)*			-		(0,0)(0,0)
 E	(a*)+			-		(0,0)(0,0)
-#E	(a*|b)*			-		(0,0)(0,0)
-E	(a*|b)*			-		(0,0)(?,?)	RE2/Go
+E	(a*|b)*			-		(0,0)(0,0)
 E	(a+|b)*			ab		(0,2)(1,2)
 E	(a+|b)+			ab		(0,2)(1,2)
 E	(a+|b)?			ab		(0,1)(0,1)
 BE	[^ab]*			cde		(0,3)
-#E	(^)*			-		(0,0)(0,0)
-E	(^)*			-		(0,0)(?,?)	RE2/Go
+E	(^)*			-		(0,0)(0,0)
 BE	a*			NULL		(0,0)
 E	([abc])*d		abbbcd		(0,6)(4,5)
 E	([abc])*bcd		abcd		(0,4)(0,1)
 E	a|b|c|d|e		e		(0,1)
 E	(a|b|c|d|e)f		ef		(0,2)(0,1)
-#E	((a*|b))*		-		(0,0)(0,0)(0,0)
-E	((a*|b))*		-		(0,0)(?,?)(?,?)	RE2/Go
+E	((a*|b))*		-		(0,0)(0,0)(0,0)
 BE	abcd*efg		abcdefg		(0,7)
 BE	ab*			xabyabbbz	(1,3)
 BE	ab*			xayabbbz	(1,2)
diff --git a/src/regexp/testdata/nullsubexpr.dat b/src/regexp/testdata/nullsubexpr.dat
index 2e18fbb9170..68d9c99996a 100644
--- a/src/regexp/testdata/nullsubexpr.dat
+++ b/src/regexp/testdata/nullsubexpr.dat
@@ -1,8 +1,7 @@
 NOTE	null subexpression matches : 2002-06-06
 
 E	(a*)*		a		(0,1)(0,1)
-#E	SAME		x		(0,0)(0,0)
-E	SAME		x		(0,0)(?,?)	RE2/Go
+E	SAME		x		(0,0)(0,0)
 E	SAME		aaaaaa		(0,6)(0,6)
 E	SAME		aaaaaax		(0,6)(0,6)
 E	(a*)+		a		(0,1)(0,1)
@@ -19,8 +18,7 @@ E	SAME		aaaaaa		(0,6)(0,6)
 E	SAME		aaaaaax		(0,6)(0,6)
 
 E	([a]*)*		a		(0,1)(0,1)
-#E	SAME		x		(0,0)(0,0)
-E	SAME		x		(0,0)(?,?)	RE2/Go
+E	SAME		x		(0,0)(0,0)
 E	SAME		aaaaaa		(0,6)(0,6)
 E	SAME		aaaaaax		(0,6)(0,6)
 E	([a]*)+		a		(0,1)(0,1)
@@ -28,8 +26,7 @@ E	SAME		x		(0,0)(0,0)
 E	SAME		aaaaaa		(0,6)(0,6)
 E	SAME		aaaaaax		(0,6)(0,6)
 E	([^b]*)*	a		(0,1)(0,1)
-#E	SAME		b		(0,0)(0,0)
-E	SAME		b		(0,0)(?,?)	RE2/Go
+E	SAME		b		(0,0)(0,0)
 E	SAME		aaaaaa		(0,6)(0,6)
 E	SAME		aaaaaab		(0,6)(0,6)
 E	([ab]*)*	a		(0,1)(0,1)
@@ -41,11 +38,9 @@ E	SAME		bbbbbb		(0,6)(0,6)
 E	SAME		aaaabcde	(0,5)(0,5)
 E	([^a]*)*	b		(0,1)(0,1)
 E	SAME		bbbbbb		(0,6)(0,6)
-#E	SAME		aaaaaa		(0,0)(0,0)
-E	SAME		aaaaaa		(0,0)(?,?)	RE2/Go
+E	SAME		aaaaaa		(0,0)(0,0)
 E	([^ab]*)*	ccccxx		(0,6)(0,6)
-#E	SAME		ababab		(0,0)(0,0)
-E	SAME		ababab		(0,0)(?,?)	RE2/Go
+E	SAME		ababab		(0,0)(0,0)
 
 E	((z)+|a)*	zabcde		(0,2)(1,2)
 
@@ -65,8 +60,7 @@ B	\(a*\)*\(x\)\(\1\)	axa	(0,3)(0,1)(1,2)(2,3)
 B	\(a*\)*\(x\)\(\1\)\(x\)	axax	(0,4)(0,1)(1,2)(2,3)(3,4)
 B	\(a*\)*\(x\)\(\1\)\(x\)	axxa	(0,3)(1,1)(1,2)(2,2)(2,3)
 
-#E	(a*)*(x)		x	(0,1)(0,0)(0,1)
-E	(a*)*(x)		x	(0,1)(?,?)(0,1)	RE2/Go
+E	(a*)*(x)		x	(0,1)(0,0)(0,1)
 E	(a*)*(x)		ax	(0,2)(0,1)(1,2)
 E	(a*)*(x)		axa	(0,2)(0,1)(1,2)
 
diff --git a/src/regexp/testdata/re2-exhaustive.txt.bz2 b/src/regexp/testdata/re2-exhaustive.txt.bz2
index a357f280169..6638476dec0 100644
Binary files a/src/regexp/testdata/re2-exhaustive.txt.bz2 and b/src/regexp/testdata/re2-exhaustive.txt.bz2 differ
diff --git a/src/regexp/testdata/re2-search.txt b/src/regexp/testdata/re2-search.txt
index 4d02e9cebd6..8c4098a4f18 100644
--- a/src/regexp/testdata/re2-search.txt
+++ b/src/regexp/testdata/re2-search.txt
@@ -1,5 +1,5 @@
 # RE2 basic search tests built by make log
-# Thu Sep 8 13:43:43 EDT 2011
+# Wed May 12 12:13:22 EDT 2021
 Regexp.SearchTests
 strings
 ""
@@ -227,22 +227,6 @@ regexps
 0-0;0-0;0-0;0-0
 strings
 ""
-""
-regexps
-"a*"
-0-0;0-0;0-0;0-0
-0-0;0-0;0-0;0-0
-"^(?:a*)$"
-0-0;0-0;0-0;0-0
-0-0;0-0;0-0;0-0
-"^(?:a*)"
-0-0;0-0;0-0;0-0
-0-0;0-0;0-0;0-0
-"(?:a*)$"
-0-0;0-0;0-0;0-0
-0-0;0-0;0-0;0-0
-strings
-""
 "xabcdx"
 regexps
 "ab|cd"
@@ -3651,6 +3635,86 @@ regexps
 0-1;0-1;0-1;0-1
 strings
 ""
+"a"
+regexps
+"a\\C+"
+-;-;-;-
+-;-;-;-
+"^(?:a\\C+)$"
+-;-;-;-
+-;-;-;-
+"^(?:a\\C+)"
+-;-;-;-
+-;-;-;-
+"(?:a\\C+)$"
+-;-;-;-
+-;-;-;-
+strings
+""
+"a"
+regexps
+"a\\C?"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C?)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C?)"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"(?:a\\C?)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+strings
+""
+"a"
+regexps
+"a\\C*?"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C*?)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C*?)"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"(?:a\\C*?)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+strings
+""
+"a"
+regexps
+"a\\C+?"
+-;-;-;-
+-;-;-;-
+"^(?:a\\C+?)$"
+-;-;-;-
+-;-;-;-
+"^(?:a\\C+?)"
+-;-;-;-
+-;-;-;-
+"(?:a\\C+?)$"
+-;-;-;-
+-;-;-;-
+strings
+""
+"a"
+regexps
+"a\\C??"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C??)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"^(?:a\\C??)"
+-;-;-;-
+0-1;0-1;0-1;0-1
+"(?:a\\C??)$"
+-;-;-;-
+0-1;0-1;0-1;0-1
+strings
+""
 "baba"
 regexps
 "a\\C*|ba\\C"
@@ -3666,7 +3730,50 @@ regexps
 -;-;-;-
 -;1-4;-;1-4
 strings
-"abc"
+""
+"Inc."
 regexps
-"a.*?c|a.*?b"
+"\\w*I\\w*"
+-;-;-;-
+-;0-3;-;0-3
+"^(?:\\w*I\\w*)$"
+-;-;-;-
+-;-;-;-
+"^(?:\\w*I\\w*)"
+-;-;-;-
+-;0-3;-;0-3
+"(?:\\w*I\\w*)$"
+-;-;-;-
+-;-;-;-
+strings
+""
+"aaa"
+regexps
+"(?:|a)*"
+0-0;0-0;0-0;0-0
+0-3;0-0;0-3;0-3
+"^(?:(?:|a)*)$"
+0-0;0-0;0-0;0-0
+0-3;0-3;0-3;0-3
+"^(?:(?:|a)*)"
+0-0;0-0;0-0;0-0
+0-3;0-0;0-3;0-3
+"(?:(?:|a)*)$"
+0-0;0-0;0-0;0-0
+0-3;0-3;0-3;0-3
+strings
+""
+"aaa"
+regexps
+"(?:|a)+"
+0-0;0-0;0-0;0-0
+0-3;0-0;0-3;0-3
+"^(?:(?:|a)+)$"
+0-0;0-0;0-0;0-0
+0-3;0-3;0-3;0-3
+"^(?:(?:|a)+)"
+0-0;0-0;0-0;0-0
+0-3;0-0;0-3;0-3
+"(?:(?:|a)+)$"
+0-0;0-0;0-0;0-0
 0-3;0-3;0-3;0-3
diff --git a/src/runtime/alg.go b/src/runtime/alg.go
index 1b3bf1180d9..978a3b85dcb 100644
--- a/src/runtime/alg.go
+++ b/src/runtime/alg.go
@@ -6,13 +6,13 @@ package runtime
 
 import (
 	"internal/cpu"
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
 const (
-	c0 = uintptr((8-sys.PtrSize)/4*2860486313 + (sys.PtrSize-4)/4*33054211828000289)
-	c1 = uintptr((8-sys.PtrSize)/4*3267000013 + (sys.PtrSize-4)/4*23344194077549503)
+	c0 = uintptr((8-goarch.PtrSize)/4*2860486313 + (goarch.PtrSize-4)/4*33054211828000289)
+	c1 = uintptr((8-goarch.PtrSize)/4*3267000013 + (goarch.PtrSize-4)/4*23344194077549503)
 )
 
 func memhash0(p unsafe.Pointer, h uintptr) uintptr {
@@ -178,28 +178,11 @@ func typehash(t *_type, p unsafe.Pointer, h uintptr) uintptr {
 		return h
 	case kindStruct:
 		s := (*structtype)(unsafe.Pointer(t))
-		memStart := uintptr(0)
-		memEnd := uintptr(0)
 		for _, f := range s.fields {
-			if memEnd > memStart && (f.name.isBlank() || f.offset() != memEnd || f.typ.tflag&tflagRegularMemory == 0) {
-				// flush any pending regular memory hashing
-				h = memhash(add(p, memStart), h, memEnd-memStart)
-				memStart = memEnd
-			}
 			if f.name.isBlank() {
 				continue
 			}
-			if f.typ.tflag&tflagRegularMemory == 0 {
-				h = typehash(f.typ, add(p, f.offset()), h)
-				continue
-			}
-			if memStart == memEnd {
-				memStart = f.offset()
-			}
-			memEnd = f.offset() + f.typ.size
-		}
-		if memEnd > memStart {
-			h = memhash(add(p, memStart), h, memEnd-memStart)
+			h = typehash(f.typ, add(p, f.offset()), h)
 		}
 		return h
 	default:
@@ -317,7 +300,7 @@ func ifaceHash(i interface {
 	return interhash(noescape(unsafe.Pointer(&i)), seed)
 }
 
-const hashRandomBytes = sys.PtrSize / 4 * 64
+const hashRandomBytes = goarch.PtrSize / 4 * 64
 
 // used in asm_{386,amd64,arm64}.s to seed the hash function
 var aeskeysched [hashRandomBytes]byte
@@ -338,7 +321,7 @@ func alginit() {
 		initAlgAES()
 		return
 	}
-	getRandomData((*[len(hashkey) * sys.PtrSize]byte)(unsafe.Pointer(&hashkey))[:])
+	getRandomData((*[len(hashkey) * goarch.PtrSize]byte)(unsafe.Pointer(&hashkey))[:])
 	hashkey[0] |= 1 // make sure these numbers are odd
 	hashkey[1] |= 1
 	hashkey[2] |= 1
@@ -354,7 +337,7 @@ func initAlgAES() {
 // Note: These routines perform the read with a native endianness.
 func readUnaligned32(p unsafe.Pointer) uint32 {
 	q := (*[4]byte)(p)
-	if sys.BigEndian {
+	if goarch.BigEndian {
 		return uint32(q[3]) | uint32(q[2])<<8 | uint32(q[1])<<16 | uint32(q[0])<<24
 	}
 	return uint32(q[0]) | uint32(q[1])<<8 | uint32(q[2])<<16 | uint32(q[3])<<24
@@ -362,7 +345,7 @@ func readUnaligned32(p unsafe.Pointer) uint32 {
 
 func readUnaligned64(p unsafe.Pointer) uint64 {
 	q := (*[8]byte)(p)
-	if sys.BigEndian {
+	if goarch.BigEndian {
 		return uint64(q[7]) | uint64(q[6])<<8 | uint64(q[5])<<16 | uint64(q[4])<<24 |
 			uint64(q[3])<<32 | uint64(q[2])<<40 | uint64(q[1])<<48 | uint64(q[0])<<56
 	}
diff --git a/src/runtime/asm.s b/src/runtime/asm.s
index 72c744925d8..0e14fcd3e6a 100644
--- a/src/runtime/asm.s
+++ b/src/runtime/asm.s
@@ -13,6 +13,6 @@ DATA runtime·no_pointers_stackmap+0x04(SB)/4, $0
 GLOBL runtime·no_pointers_stackmap(SB),RODATA, $8
 
 #ifndef GOARCH_amd64
-TEXT ·sigpanic0(SB),NOSPLIT,$0-0
+TEXT ·sigpanic0(SB),NOSPLIT,$0-0
 	JMP	·sigpanic(SB)
 #endif
diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s
index ec5ea58028b..11c60309f4e 100644
--- a/src/runtime/asm_386.s
+++ b/src/runtime/asm_386.s
@@ -244,10 +244,8 @@ ok:
 
 	// create a new goroutine to start program
 	PUSHL	$runtime·mainPC(SB)	// entry
-	PUSHL	$0	// arg size
 	CALL	runtime·newproc(SB)
 	POPL	AX
-	POPL	AX
 
 	// start this M
 	CALL	runtime·mstart(SB)
@@ -584,26 +582,6 @@ TEXT ·publicationBarrier(SB),NOSPLIT,$0-0
 	// compile barrier.
 	RET
 
-// void jmpdefer(fn, sp);
-// called from deferreturn.
-// 1. pop the caller
-// 2. sub 5 bytes (the length of CALL & a 32 bit displacement) from the callers
-//    return (when building for shared libraries, subtract 16 bytes -- 5 bytes
-//    for CALL & displacement to call __x86.get_pc_thunk.cx, 6 bytes for the
-//    LEAL to load the offset into BX, and finally 5 for the call & displacement)
-// 3. jmp to the argument
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0-8
-	MOVL	fv+0(FP), DX	// fn
-	MOVL	argp+4(FP), BX	// caller sp
-	LEAL	-4(BX), SP	// caller sp after CALL
-#ifdef GOBUILDMODE_shared
-	SUBL	$16, (SP)	// return to CALL again
-#else
-	SUBL	$5, (SP)	// return to CALL again
-#endif
-	MOVL	0(DX), BX
-	JMP	BX	// but first run the deferred function
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s
index 14f29e19647..2083ecb53e8 100644
--- a/src/runtime/asm_amd64.s
+++ b/src/runtime/asm_amd64.s
@@ -214,10 +214,8 @@ ok:
 	// create a new goroutine to start program
 	MOVQ	$runtime·mainPC(SB), AX		// entry
 	PUSHQ	AX
-	PUSHQ	$0			// arg size
 	CALL	runtime·newproc(SB)
 	POPQ	AX
-	POPQ	AX
 
 	// start this M
 	CALL	runtime·mstart(SB)
@@ -279,7 +277,6 @@ TEXT gogo<>(SB), NOSPLIT, $0
 // Switch to m->g0's stack, call fn(g).
 // Fn must never return. It should gogo(&g->sched)
 // to keep running g.
-#ifdef GOEXPERIMENT_regabiargs
 TEXT runtime·mcall(SB), NOSPLIT, $0-8
 	MOVQ	AX, DX	// DX = fn
 
@@ -308,38 +305,6 @@ goodm:
 	POPQ	AX
 	JMP	runtime·badmcall2(SB)
 	RET
-#else
-TEXT runtime·mcall(SB), NOSPLIT, $0-8
-	MOVQ	fn+0(FP), DI
-
-	get_tls(CX)
-	MOVQ	g(CX), AX	// save state in g->sched
-	MOVQ	0(SP), BX	// caller's PC
-	MOVQ	BX, (g_sched+gobuf_pc)(AX)
-	LEAQ	fn+0(FP), BX	// caller's SP
-	MOVQ	BX, (g_sched+gobuf_sp)(AX)
-	MOVQ	BP, (g_sched+gobuf_bp)(AX)
-
-	// switch to m->g0 & its stack, call fn
-	MOVQ	g(CX), BX
-	MOVQ	g_m(BX), BX
-	MOVQ	m_g0(BX), SI
-	CMPQ	SI, AX	// if g == m->g0 call badmcall
-	JNE	3(PC)
-	MOVQ	$runtime·badmcall(SB), AX
-	JMP	AX
-	MOVQ	SI, g(CX)	// g = m->g0
-	MOVQ	SI, R14	// set the g register
-	MOVQ	(g_sched+gobuf_sp)(SI), SP	// sp = m->g0->sched.sp
-	PUSHQ	AX
-	MOVQ	DI, DX
-	MOVQ	0(DI), DI
-	CALL	DI
-	POPQ	AX
-	MOVQ	$runtime·badmcall2(SB), AX
-	JMP	AX
-	RET
-#endif
 
 // systemstack_switch is a dummy routine that systemstack leaves at the bottom
 // of the G stack. We need to distinguish the routine that
@@ -467,9 +432,8 @@ TEXT runtime·morestack_noctxt(SB),NOSPLIT,$0
 	MOVL	$0, DX
 	JMP	runtime·morestack(SB)
 
-#ifdef GOEXPERIMENT_regabireflect
 // spillArgs stores return values from registers to a *internal/abi.RegArgs in R12.
-TEXT ·spillArgs(SB),NOSPLIT,$0-0
+TEXT ·spillArgs(SB),NOSPLIT,$0-0
 	MOVQ AX, 0(R12)
 	MOVQ BX, 8(R12)
 	MOVQ CX, 16(R12)
@@ -497,7 +461,7 @@ TEXT ·spillArgs(SB),NOSPLIT,$0-0
 	RET
 
 // unspillArgs loads args into registers from a *internal/abi.RegArgs in R12.
-TEXT ·unspillArgs(SB),NOSPLIT,$0-0
+TEXT ·unspillArgs(SB),NOSPLIT,$0-0
 	MOVQ 0(R12), AX
 	MOVQ 8(R12), BX
 	MOVQ 16(R12), CX
@@ -523,15 +487,6 @@ TEXT ·unspillArgs(SB),NOSPLIT,$0-0
 	MOVQ 176(R12), X13
 	MOVQ 184(R12), X14
 	RET
-#else
-// spillArgs stores return values from registers to a pointer in R12.
-TEXT ·spillArgs(SB),NOSPLIT,$0-0
-	RET
-
-// unspillArgs loads args into registers from a pointer in R12.
-TEXT ·unspillArgs(SB),NOSPLIT,$0-0
-	RET
-#endif
 
 // reflectcall: call a function with the given argument list
 // func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
@@ -588,7 +543,7 @@ TEXT NAME(SB), WRAPPER, $MAXSIZE-48;		\
 	REP;MOVSB;				\
 	/* set up argument registers */		\
 	MOVQ    regArgs+40(FP), R12;		\
-	CALL    ·unspillArgs(SB);		\
+	CALL    ·unspillArgs(SB);		\
 	/* call function */			\
 	MOVQ	f+8(FP), DX;			\
 	PCDATA  $PCDATA_StackMapIndex, $0;	\
@@ -596,7 +551,7 @@ TEXT NAME(SB), WRAPPER, $MAXSIZE-48;		\
 	CALL	R12;				\
 	/* copy register return values back */		\
 	MOVQ    regArgs+40(FP), R12;		\
-	CALL    ·spillArgs(SB);		\
+	CALL    ·spillArgs(SB);		\
 	MOVLQZX	stackArgsSize+24(FP), CX;		\
 	MOVLQZX	stackRetOffset+28(FP), BX;		\
 	MOVQ	stackArgs+16(FP), DI;		\
@@ -664,31 +619,12 @@ TEXT ·publicationBarrier(SB),NOSPLIT,$0-0
 	// compile barrier.
 	RET
 
-// func jmpdefer(fv *funcval, argp uintptr)
-// argp is a caller SP.
-// called from deferreturn.
-// 1. pop the caller
-// 2. sub 5 bytes from the callers return
-// 3. jmp to the argument
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0-16
-	MOVQ	fv+0(FP), DX	// fn
-	MOVQ	argp+8(FP), BX	// caller sp
-	LEAQ	-8(BX), SP	// caller sp after CALL
-	MOVQ	-8(SP), BP	// restore BP as if deferreturn returned (harmless if framepointers not in use)
-	SUBQ	$5, (SP)	// return to CALL again
-	MOVQ	0(DX), BX
-	JMP	BX	// but first run the deferred function
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
 // or else unwinding from systemstack_switch is incorrect.
 // Smashes R9.
 TEXT gosave_systemstack_switch<>(SB),NOSPLIT,$0
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R14)
-	MOVQ	g(R14), R14
-#endif
 	MOVQ	$runtime·systemstack_switch(SB), R9
 	MOVQ	R9, (g_sched+gobuf_pc)(R14)
 	LEAQ	8(SP), R9
@@ -1009,61 +945,34 @@ done:
 // func memhash(p unsafe.Pointer, h, s uintptr) uintptr
 // hash function using AES hardware instructions
 TEXT runtime·memhash(SB),NOSPLIT,$0-32
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = ptr to data
 	// BX = seed
 	// CX = size
-#endif
 	CMPB	runtime·useAeshash(SB), $0
 	JEQ	noaes
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	p+0(FP), AX	// ptr to data
-	MOVQ	s+16(FP), CX	// size
-	LEAQ	ret+24(FP), DX
-#endif
 	JMP	aeshashbody<>(SB)
 noaes:
 	JMP	runtime·memhashFallback(SB)
 
 // func strhash(p unsafe.Pointer, h uintptr) uintptr
 TEXT runtime·strhash(SB),NOSPLIT,$0-24
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = ptr to string struct
 	// BX = seed
-#endif
 	CMPB	runtime·useAeshash(SB), $0
 	JEQ	noaes
-#ifndef GOEXPERIMENT_regabiargs
-	MOVQ	p+0(FP), AX	// ptr to string struct
-#endif
 	MOVQ	8(AX), CX	// length of string
 	MOVQ	(AX), AX	// string data
-#ifndef GOEXPERIMENT_regabiargs
-	LEAQ	ret+16(FP), DX
-#endif
 	JMP	aeshashbody<>(SB)
 noaes:
 	JMP	runtime·strhashFallback(SB)
 
 // AX: data
-#ifdef GOEXPERIMENT_regabiargs
 // BX: hash seed
-#else
-// h+8(FP): hash seed
-#endif
 // CX: length
-#ifdef GOEXPERIMENT_regabiargs
 // At return: AX = return value
-#else
-// DX: address to put return value
-#endif
 TEXT aeshashbody<>(SB),NOSPLIT,$0-0
 	// Fill an SSE register with our seeds.
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	BX, X0				// 64 bits of per-table hash seed
-#else
-	MOVQ	h+8(FP), X0			// 64 bits of per-table hash seed
-#endif
 	PINSRW	$4, CX, X0			// 16 bits of length
 	PSHUFHW $0, X0, X0			// repeat length 4 times total
 	MOVO	X0, X1				// save unscrambled seed
@@ -1100,11 +1009,7 @@ final1:
 	AESENC	X1, X1	// scramble combo 3 times
 	AESENC	X1, X1
 	AESENC	X1, X1
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X1, AX	// return X1
-#else
-	MOVQ	X1, (DX)
-#endif
 	RET
 
 endofpage:
@@ -1120,11 +1025,7 @@ endofpage:
 aes0:
 	// Return scrambled input seed
 	AESENC	X0, X0
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X0, AX	// return X0
-#else
-	MOVQ	X0, (DX)
-#endif
 	RET
 
 aes16:
@@ -1154,11 +1055,7 @@ aes17to32:
 
 	// combine results
 	PXOR	X3, X2
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X2, AX	// return X2
-#else
-	MOVQ	X2, (DX)
-#endif
 	RET
 
 aes33to64:
@@ -1200,11 +1097,7 @@ aes33to64:
 	PXOR	X6, X4
 	PXOR	X7, X5
 	PXOR	X5, X4
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X4, AX	// return X4
-#else
-	MOVQ	X4, (DX)
-#endif
 	RET
 
 aes65to128:
@@ -1286,15 +1179,9 @@ aes65to128:
 	PXOR	X10, X8
 	PXOR	X11, X9
 	PXOR	X9, X8
-#ifdef GOEXPERIMENT_regabig
 	// X15 must be zero on return
 	PXOR	X15, X15
-#endif
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X8, AX	// return X8
-#else
-	MOVQ	X8, (DX)
-#endif
 	RET
 
 aes129plus:
@@ -1410,41 +1297,24 @@ aesloop:
 	PXOR	X10, X8
 	PXOR	X11, X9
 	PXOR	X9, X8
-#ifdef GOEXPERIMENT_regabig
 	// X15 must be zero on return
 	PXOR	X15, X15
-#endif
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X8, AX	// return X8
-#else
-	MOVQ	X8, (DX)
-#endif
 	RET
 
 // func memhash32(p unsafe.Pointer, h uintptr) uintptr
 // ABIInternal for performance.
 TEXT runtime·memhash32(SB),NOSPLIT,$0-24
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = ptr to data
 	// BX = seed
-#endif
 	CMPB	runtime·useAeshash(SB), $0
 	JEQ	noaes
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	BX, X0	// X0 = seed
-#else
-	MOVQ	p+0(FP), AX	// ptr to data
-	MOVQ	h+8(FP), X0	// seed
-#endif
 	PINSRD	$2, (AX), X0	// data
 	AESENC	runtime·aeskeysched+0(SB), X0
 	AESENC	runtime·aeskeysched+16(SB), X0
 	AESENC	runtime·aeskeysched+32(SB), X0
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X0, AX	// return X0
-#else
-	MOVQ	X0, ret+16(FP)
-#endif
 	RET
 noaes:
 	JMP	runtime·memhash32Fallback(SB)
@@ -1452,28 +1322,16 @@ noaes:
 // func memhash64(p unsafe.Pointer, h uintptr) uintptr
 // ABIInternal for performance.
 TEXT runtime·memhash64(SB),NOSPLIT,$0-24
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = ptr to data
 	// BX = seed
-#else
-#endif
 	CMPB	runtime·useAeshash(SB), $0
 	JEQ	noaes
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	BX, X0	// X0 = seed
-#else
-	MOVQ	p+0(FP), AX	// ptr to data
-	MOVQ	h+8(FP), X0	// seed
-#endif
 	PINSRQ	$1, (AX), X0	// data
 	AESENC	runtime·aeskeysched+0(SB), X0
 	AESENC	runtime·aeskeysched+16(SB), X0
 	AESENC	runtime·aeskeysched+32(SB), X0
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	X0, AX	// return X0
-#else
-	MOVQ	X0, ret+16(FP)
-#endif
 	RET
 noaes:
 	JMP	runtime·memhash64Fallback(SB)
@@ -1596,10 +1454,10 @@ TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
 // This function is injected from the signal handler for panicking
 // signals. It is quite painful to set X15 in the signal context,
 // so we do it here.
-TEXT ·sigpanic0(SB),NOSPLIT,$0-0
-#ifdef GOEXPERIMENT_regabig
+TEXT ·sigpanic0(SB),NOSPLIT,$0-0
 	get_tls(R14)
 	MOVQ	g(R14), R14
+#ifndef GOOS_plan9
 	XORPS	X15, X15
 #endif
 	JMP	·sigpanic(SB)
@@ -1619,13 +1477,7 @@ TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$112
 	MOVQ	R13, 104(SP)
 	// TODO: Consider passing g.m.p in as an argument so they can be shared
 	// across a sequence of write barriers.
-#ifdef GOEXPERIMENT_regabig
 	MOVQ	g_m(R14), R13
-#else
-	get_tls(R13)
-	MOVQ	g(R13), R13
-	MOVQ	g_m(R13), R13
-#endif
 	MOVQ	m_p(R13), R13
 	MOVQ	(p_wbBuf+wbBuf_next)(R13), R12
 	// Increment wbBuf.next position.
@@ -1956,146 +1808,61 @@ TEXT runtime·debugCallPanicked(SB),NOSPLIT,$16-16
 // The tail call makes these stubs disappear in backtraces.
 // Defined as ABIInternal since they do not use the stack-based Go ABI.
 TEXT runtime·panicIndex(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicIndex(SB)
 TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicIndexU(SB)
 TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceAlen(SB)
 TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceAlenU(SB)
 TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceAcap(SB)
 TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceAcapU(SB)
 TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceB(SB)
 TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceBU(SB)
 TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	DX, AX
-#else
-	MOVQ	DX, x+0(FP)
-	MOVQ	BX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3Alen(SB)
 TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	DX, AX
-#else
-	MOVQ	DX, x+0(FP)
-	MOVQ	BX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3AlenU(SB)
 TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	DX, AX
-#else
-	MOVQ	DX, x+0(FP)
-	MOVQ	BX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3Acap(SB)
 TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	DX, AX
-#else
-	MOVQ	DX, x+0(FP)
-	MOVQ	BX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3AcapU(SB)
 TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3B(SB)
 TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, AX
 	MOVQ	DX, BX
-#else
-	MOVQ	CX, x+0(FP)
-	MOVQ	DX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3BU(SB)
 TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3C(SB)
 TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	CX, BX
-#else
-	MOVQ	AX, x+0(FP)
-	MOVQ	CX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSlice3CU(SB)
 TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	DX, AX
-#else
-	MOVQ	DX, x+0(FP)
-	MOVQ	BX, y+8(FP)
-#endif
 	JMP	runtime·goPanicSliceConvert(SB)
 
 #ifdef GOOS_android
diff --git a/src/runtime/asm_arm.s b/src/runtime/asm_arm.s
index e779fc8f844..a1164781d2e 100644
--- a/src/runtime/asm_arm.s
+++ b/src/runtime/asm_arm.s
@@ -142,6 +142,11 @@ TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
 
 	BL	runtime·emptyfunc(SB)	// fault if stack check is wrong
 
+#ifdef GOOS_openbsd
+	// Save g to TLS so that it is available from signal trampoline.
+	BL	runtime·save_g(SB)
+#endif
+
 	BL	runtime·_initcgo(SB)	// will clobber R0-R3
 
 	// update stackguard after _cgo_init
@@ -163,14 +168,13 @@ TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
 	BL	runtime·schedinit(SB)
 
 	// create a new goroutine to start program
+	SUB	$8, R13
 	MOVW	$runtime·mainPC(SB), R0
-	MOVW.W	R0, -4(R13)
-	MOVW	$8, R0
-	MOVW.W	R0, -4(R13)
+	MOVW	R0, 4(R13)	// arg 1: fn
 	MOVW	$0, R0
-	MOVW.W	R0, -4(R13)	// push $0 as guard
+	MOVW	R0, 0(R13)	// dummy LR
 	BL	runtime·newproc(SB)
-	MOVW	$12(R13), R13	// pop args and LR
+	ADD	$8, R13	// pop args and LR
 
 	// start this M
 	BL	runtime·mstart(SB)
@@ -502,20 +506,6 @@ CALLFN(·call268435456, 268435456)
 CALLFN(·call536870912, 536870912)
 CALLFN(·call1073741824, 1073741824)
 
-// void jmpdefer(fn, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 4 bytes to get back to BL deferreturn
-// 3. B to fn
-TEXT runtime·jmpdefer(SB),NOSPLIT,$0-8
-	MOVW	0(R13), LR
-	MOVW	$-4(LR), LR	// BL deferreturn
-	MOVW	fv+0(FP), R7
-	MOVW	argp+4(FP), R13
-	MOVW	$-4(R13), R13	// SP is 4 below argp, due to saved LR
-	MOVW	0(R7), R1
-	B	(R1)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
@@ -633,9 +623,13 @@ TEXT	·cgocallback(SB),NOSPLIT,$12-12
 	NO_LOCAL_POINTERS
 
 	// Load m and g from thread-local storage.
+#ifdef GOOS_openbsd
+	BL	runtime·load_g(SB)
+#else
 	MOVB	runtime·iscgo(SB), R0
 	CMP	$0, R0
 	BL.NE	runtime·load_g(SB)
+#endif
 
 	// If g is nil, Go did not create the current thread.
 	// Call needm to obtain one for temporary use.
@@ -744,6 +738,9 @@ TEXT setg<>(SB),NOSPLIT|NOFRAME,$0-0
 	// Save g to thread-local storage.
 #ifdef GOOS_windows
 	B	runtime·save_g(SB)
+#else
+#ifdef GOOS_openbsd
+	B	runtime·save_g(SB)
 #else
 	MOVB	runtime·iscgo(SB), R0
 	CMP	$0, R0
@@ -753,6 +750,7 @@ TEXT setg<>(SB),NOSPLIT|NOFRAME,$0-0
 	MOVW	g, R0
 	RET
 #endif
+#endif
 
 TEXT runtime·emptyfunc(SB),0,$0-0
 	RET
diff --git a/src/runtime/asm_arm64.s b/src/runtime/asm_arm64.s
index 2d495397a8d..e51ce2f8316 100644
--- a/src/runtime/asm_arm64.s
+++ b/src/runtime/asm_arm64.s
@@ -87,14 +87,11 @@ nocgo:
 
 	// create a new goroutine to start program
 	MOVD	$runtime·mainPC(SB), R0		// entry
-	MOVD	RSP, R7
-	MOVD.W	$0, -8(R7)
-	MOVD.W	R0, -8(R7)
-	MOVD.W	$0, -8(R7)
-	MOVD.W	$0, -8(R7)
-	MOVD	R7, RSP
+	SUB	$16, RSP
+	MOVD	R0, 8(RSP) // arg
+	MOVD	$0, 0(RSP) // dummy LR
 	BL	runtime·newproc(SB)
-	ADD	$32, RSP
+	ADD	$16, RSP
 
 	// start this M
 	BL	runtime·mstart(SB)
@@ -103,7 +100,7 @@ nocgo:
 	MOVD	R0, (R0)	// boom
 	UNDEF
 
-DATA	runtime·mainPC+0(SB)/8,$runtime·main(SB)
+DATA	runtime·mainPC+0(SB)/8,$runtime·main(SB)
 GLOBL	runtime·mainPC(SB),RODATA,$8
 
 TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0
@@ -152,7 +149,13 @@ TEXT gogo<>(SB), NOSPLIT|NOFRAME, $0
 // Switch to m->g0's stack, call fn(g).
 // Fn must never return. It should gogo(&g->sched)
 // to keep running g.
-TEXT runtime·mcall(SB), NOSPLIT|NOFRAME, $0-8
+TEXT runtime·mcall(SB), NOSPLIT|NOFRAME, $0-8
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R0, R26				// context
+#else
+	MOVD	fn+0(FP), R26			// context
+#endif
+
 	// Save caller state in g->sched
 	MOVD	RSP, R0
 	MOVD	R0, (g_sched+gobuf_sp)(g)
@@ -168,14 +171,18 @@ TEXT runtime·mcall(SB), NOSPLIT|NOFRAME, $0-8
 	CMP	g, R3
 	BNE	2(PC)
 	B	runtime·badmcall(SB)
-	MOVD	fn+0(FP), R26			// context
-	MOVD	0(R26), R4			// code pointer
+
 	MOVD	(g_sched+gobuf_sp)(g), R0
 	MOVD	R0, RSP	// sp = m->g0->sched.sp
 	MOVD	(g_sched+gobuf_bp)(g), R29
-	MOVD	R3, -8(RSP)
-	MOVD	$0, -16(RSP)
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R3, R0				// arg = g
+#else
+	MOVD	R3, -8(RSP)			// arg = g
+#endif
+	MOVD	$0, -16(RSP)			// dummy LR
 	SUB	$16, RSP
+	MOVD	0(R26), R4			// code pointer
 	BL	(R4)
 	B	runtime·badmcall2(SB)
 
@@ -310,6 +317,86 @@ TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVW	$0, R26
 	B runtime·morestack(SB)
 
+#ifdef GOEXPERIMENT_regabireflect
+// spillArgs stores return values from registers to a *internal/abi.RegArgs in R20.
+TEXT ·spillArgs(SB),NOSPLIT,$0-0
+	MOVD	R0, (0*8)(R20)
+	MOVD	R1, (1*8)(R20)
+	MOVD	R2, (2*8)(R20)
+	MOVD	R3, (3*8)(R20)
+	MOVD	R4, (4*8)(R20)
+	MOVD	R5, (5*8)(R20)
+	MOVD	R6, (6*8)(R20)
+	MOVD	R7, (7*8)(R20)
+	MOVD	R8, (8*8)(R20)
+	MOVD	R9, (9*8)(R20)
+	MOVD	R10, (10*8)(R20)
+	MOVD	R11, (11*8)(R20)
+	MOVD	R12, (12*8)(R20)
+	MOVD	R13, (13*8)(R20)
+	MOVD	R14, (14*8)(R20)
+	MOVD	R15, (15*8)(R20)
+	FMOVD	F0, (16*8)(R20)
+	FMOVD	F1, (17*8)(R20)
+	FMOVD	F2, (18*8)(R20)
+	FMOVD	F3, (19*8)(R20)
+	FMOVD	F4, (20*8)(R20)
+	FMOVD	F5, (21*8)(R20)
+	FMOVD	F6, (22*8)(R20)
+	FMOVD	F7, (23*8)(R20)
+	FMOVD	F8, (24*8)(R20)
+	FMOVD	F9, (25*8)(R20)
+	FMOVD	F10, (26*8)(R20)
+	FMOVD	F11, (27*8)(R20)
+	FMOVD	F12, (28*8)(R20)
+	FMOVD	F13, (29*8)(R20)
+	FMOVD	F14, (30*8)(R20)
+	FMOVD	F15, (31*8)(R20)
+	RET
+
+// unspillArgs loads args into registers from a *internal/abi.RegArgs in R20.
+TEXT ·unspillArgs(SB),NOSPLIT,$0-0
+	MOVD	(0*8)(R20), R0
+	MOVD	(1*8)(R20), R1
+	MOVD	(2*8)(R20), R2
+	MOVD	(3*8)(R20), R3
+	MOVD	(4*8)(R20), R4
+	MOVD	(5*8)(R20), R5
+	MOVD	(6*8)(R20), R6
+	MOVD	(7*8)(R20), R7
+	MOVD	(8*8)(R20), R8
+	MOVD	(9*8)(R20), R9
+	MOVD	(10*8)(R20), R10
+	MOVD	(11*8)(R20), R11
+	MOVD	(12*8)(R20), R12
+	MOVD	(13*8)(R20), R13
+	MOVD	(14*8)(R20), R14
+	MOVD	(15*8)(R20), R15
+	FMOVD	(16*8)(R20), F0
+	FMOVD	(17*8)(R20), F1
+	FMOVD	(18*8)(R20), F2
+	FMOVD	(19*8)(R20), F3
+	FMOVD	(20*8)(R20), F4
+	FMOVD	(21*8)(R20), F5
+	FMOVD	(22*8)(R20), F6
+	FMOVD	(23*8)(R20), F7
+	FMOVD	(24*8)(R20), F8
+	FMOVD	(25*8)(R20), F9
+	FMOVD	(26*8)(R20), F10
+	FMOVD	(27*8)(R20), F11
+	FMOVD	(28*8)(R20), F12
+	FMOVD	(29*8)(R20), F13
+	FMOVD	(30*8)(R20), F14
+	FMOVD	(31*8)(R20), F15
+	RET
+#else
+TEXT ·spillArgs(SB),NOSPLIT,$0-0
+	RET
+
+TEXT ·unspillArgs(SB),NOSPLIT,$0-0
+	RET
+#endif
+
 // reflectcall: call a function with the given argument list
 // func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
 // we don't have variable-sized frames, so we use a small number
@@ -381,12 +468,17 @@ TEXT NAME(SB), WRAPPER, $MAXSIZE-48;		\
 	MOVBU.P	R7, 1(R5);			\
 	CMP	R5, R6;				\
 	BNE	-3(PC);				\
+	/* set up argument registers */		\
+	MOVD	regArgs+40(FP), R20;		\
+	CALL	·unspillArgs(SB);		\
 	/* call function */			\
 	MOVD	f+8(FP), R26;			\
-	MOVD	(R26), R0;			\
-	PCDATA  $PCDATA_StackMapIndex, $0;	\
-	BL	(R0);				\
+	MOVD	(R26), R20;			\
+	PCDATA	$PCDATA_StackMapIndex, $0;	\
+	BL	(R20);				\
 	/* copy return values back */		\
+	MOVD	regArgs+40(FP), R20;		\
+	CALL	·spillArgs(SB);		\
 	MOVD	stackArgsType+0(FP), R7;		\
 	MOVD	stackArgs+16(FP), R3;			\
 	MOVWU	stackArgsSize+24(FP), R4;			\
@@ -403,11 +495,12 @@ TEXT NAME(SB), WRAPPER, $MAXSIZE-48;		\
 // to reflectcallmove. It does not follow the Go ABI; it expects its
 // arguments in registers.
 TEXT callRet<>(SB), NOSPLIT, $48-0
+	NO_LOCAL_POINTERS
 	MOVD	R7, 8(RSP)
 	MOVD	R3, 16(RSP)
 	MOVD	R5, 24(RSP)
 	MOVD	R4, 32(RSP)
-	MOVD	$0, 40(RSP)
+	MOVD	R20, 40(RSP)
 	BL	runtime·reflectcallmove(SB)
 	RET
 
@@ -440,12 +533,14 @@ CALLFN(·call536870912, 536870912)
 CALLFN(·call1073741824, 1073741824)
 
 // func memhash32(p unsafe.Pointer, h uintptr) uintptr
-TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-24
-	MOVB	runtime·useAeshash(SB), R0
-	CBZ	R0, noaes
+TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-24
+	MOVB	runtime·useAeshash(SB), R10
+	CBZ	R10, noaes
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	p+0(FP), R0
 	MOVD	h+8(FP), R1
 	MOVD	$ret+16(FP), R2
+#endif
 	MOVD	$runtime·aeskeysched+0(SB), R3
 
 	VEOR	V0.B16, V0.B16, V0.B16
@@ -459,18 +554,24 @@ TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-24
 	AESMC	V0.B16, V0.B16
 	AESE	V2.B16, V0.B16
 
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V0.D[0], R0
+#else
 	VST1	[V0.D1], (R2)
+#endif
 	RET
 noaes:
-	B	runtime·memhash32Fallback(SB)
+	B	runtime·memhash32Fallback(SB)
 
 // func memhash64(p unsafe.Pointer, h uintptr) uintptr
-TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-24
-	MOVB	runtime·useAeshash(SB), R0
-	CBZ	R0, noaes
+TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-24
+	MOVB	runtime·useAeshash(SB), R10
+	CBZ	R10, noaes
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	p+0(FP), R0
 	MOVD	h+8(FP), R1
 	MOVD	$ret+16(FP), R2
+#endif
 	MOVD	$runtime·aeskeysched+0(SB), R3
 
 	VEOR	V0.B16, V0.B16, V0.B16
@@ -484,75 +585,89 @@ TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-24
 	AESMC	V0.B16, V0.B16
 	AESE	V2.B16, V0.B16
 
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V0.D[0], R0
+#else
 	VST1	[V0.D1], (R2)
+#endif
 	RET
 noaes:
-	B	runtime·memhash64Fallback(SB)
+	B	runtime·memhash64Fallback(SB)
 
 // func memhash(p unsafe.Pointer, h, size uintptr) uintptr
-TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-32
-	MOVB	runtime·useAeshash(SB), R0
-	CBZ	R0, noaes
+TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-32
+	MOVB	runtime·useAeshash(SB), R10
+	CBZ	R10, noaes
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	p+0(FP), R0
-	MOVD	s+16(FP), R1
-	MOVD	h+8(FP), R3
-	MOVD	$ret+24(FP), R2
+	MOVD	h+8(FP), R1
+	MOVD	s+16(FP), R2
+	MOVD	$ret+24(FP), R8
+#endif
 	B	aeshashbody<>(SB)
 noaes:
-	B	runtime·memhashFallback(SB)
+	B	runtime·memhashFallback(SB)
 
 // func strhash(p unsafe.Pointer, h uintptr) uintptr
-TEXT runtime·strhash(SB),NOSPLIT|NOFRAME,$0-24
-	MOVB	runtime·useAeshash(SB), R0
-	CBZ	R0, noaes
-	MOVD	p+0(FP), R10 // string pointer
-	LDP	(R10), (R0, R1) //string data/ length
-	MOVD	h+8(FP), R3
-	MOVD	$ret+16(FP), R2 // return adddress
+TEXT runtime·strhash(SB),NOSPLIT|NOFRAME,$0-24
+	MOVB	runtime·useAeshash(SB), R10
+	CBZ	R10, noaes
+#ifdef GOEXPERIMENT_regabiargs
+	LDP	(R0), (R0, R2)	// string data / length
+#else
+	MOVD	p+0(FP), R10	// string pointer
+	LDP	(R10), (R0, R2)	// string data / length
+	MOVD	h+8(FP), R1
+	MOVD	$ret+16(FP), R8	// return adddress
+#endif
 	B	aeshashbody<>(SB)
 noaes:
-	B	runtime·strhashFallback(SB)
+	B	runtime·strhashFallback(SB)
 
 // R0: data
-// R1: length
-// R2: address to put return value
-// R3: seed data
+// R1: seed data
+// R2: length
+#ifdef GOEXPERIMENT_regabiargs
+// At return, R0 = return value
+#else
+// R8: address to put return value
+#endif
 TEXT aeshashbody<>(SB),NOSPLIT|NOFRAME,$0
 	VEOR	V30.B16, V30.B16, V30.B16
-	VMOV	R3, V30.D[0]
-	VMOV	R1, V30.D[1] // load length into seed
+	VMOV	R1, V30.D[0]
+	VMOV	R2, V30.D[1] // load length into seed
 
 	MOVD	$runtime·aeskeysched+0(SB), R4
 	VLD1.P	16(R4), [V0.B16]
 	AESE	V30.B16, V0.B16
 	AESMC	V0.B16, V0.B16
-	CMP	$16, R1
+	CMP	$16, R2
 	BLO	aes0to15
 	BEQ	aes16
-	CMP	$32, R1
+	CMP	$32, R2
 	BLS	aes17to32
-	CMP	$64, R1
+	CMP	$64, R2
 	BLS	aes33to64
-	CMP	$128, R1
+	CMP	$128, R2
 	BLS	aes65to128
 	B	aes129plus
 
 aes0to15:
-	CBZ	R1, aes0
+	CBZ	R2, aes0
 	VEOR	V2.B16, V2.B16, V2.B16
-	TBZ	$3, R1, less_than_8
+	TBZ	$3, R2, less_than_8
 	VLD1.P	8(R0), V2.D[0]
 
 less_than_8:
-	TBZ	$2, R1, less_than_4
+	TBZ	$2, R2, less_than_4
 	VLD1.P	4(R0), V2.S[2]
 
 less_than_4:
-	TBZ	$1, R1, less_than_2
+	TBZ	$1, R2, less_than_2
 	VLD1.P	2(R0), V2.H[6]
 
 less_than_2:
-	TBZ	$0, R1, done
+	TBZ	$0, R2, done
 	VLD1	(R0), V2.B[14]
 done:
 	AESE	V0.B16, V2.B16
@@ -561,11 +676,21 @@ done:
 	AESMC	V2.B16, V2.B16
 	AESE	V0.B16, V2.B16
 
-	VST1	[V2.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V2.D[0], R0
+#else
+	VST1	[V2.D1], (R8)
+#endif
 	RET
+
 aes0:
-	VST1	[V0.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V0.D[0], R0
+#else
+	VST1	[V0.D1], (R8)
+#endif
 	RET
+
 aes16:
 	VLD1	(R0), [V2.B16]
 	B	done
@@ -575,7 +700,7 @@ aes17to32:
 	VLD1	(R4), [V1.B16]
 	AESE	V30.B16, V1.B16
 	AESMC	V1.B16, V1.B16
-	SUB	$16, R1, R10
+	SUB	$16, R2, R10
 	VLD1.P	(R0)(R10), [V2.B16]
 	VLD1	(R0), [V3.B16]
 
@@ -593,7 +718,11 @@ aes17to32:
 	AESE	V1.B16, V3.B16
 
 	VEOR	V3.B16, V2.B16, V2.B16
-	VST1	[V2.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V2.D[0], R0
+#else
+	VST1	[V2.D1], (R8)
+#endif
 	RET
 
 aes33to64:
@@ -604,7 +733,7 @@ aes33to64:
 	AESMC	V2.B16, V2.B16
 	AESE	V30.B16, V3.B16
 	AESMC	V3.B16, V3.B16
-	SUB	$32, R1, R10
+	SUB	$32, R2, R10
 
 	VLD1.P	(R0)(R10), [V4.B16, V5.B16]
 	VLD1	(R0), [V6.B16, V7.B16]
@@ -636,7 +765,11 @@ aes33to64:
 	VEOR	V7.B16, V5.B16, V5.B16
 	VEOR	V5.B16, V4.B16, V4.B16
 
-	VST1	[V4.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V4.D[0], R0
+#else
+	VST1	[V4.D1], (R8)
+#endif
 	RET
 
 aes65to128:
@@ -657,7 +790,7 @@ aes65to128:
 	AESE	V30.B16, V7.B16
 	AESMC	V7.B16, V7.B16
 
-	SUB	$64, R1, R10
+	SUB	$64, R2, R10
 	VLD1.P	(R0)(R10), [V8.B16, V9.B16, V10.B16, V11.B16]
 	VLD1	(R0), [V12.B16, V13.B16, V14.B16, V15.B16]
 	AESE	V0.B16,	 V8.B16
@@ -711,7 +844,11 @@ aes65to128:
 	VEOR	V11.B16, V9.B16, V9.B16
 	VEOR	V9.B16, V8.B16, V8.B16
 
-	VST1	[V8.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V8.D[0], R0
+#else
+	VST1	[V8.D1], (R8)
+#endif
 	RET
 
 aes129plus:
@@ -732,12 +869,12 @@ aes129plus:
 	AESMC	V6.B16, V6.B16
 	AESE	V30.B16, V7.B16
 	AESMC	V7.B16, V7.B16
-	ADD	R0, R1, R10
+	ADD	R0, R2, R10
 	SUB	$128, R10, R10
 	VLD1.P	64(R10), [V8.B16, V9.B16, V10.B16, V11.B16]
 	VLD1	(R10), [V12.B16, V13.B16, V14.B16, V15.B16]
-	SUB	$1, R1, R1
-	LSR	$7, R1, R1
+	SUB	$1, R2, R2
+	LSR	$7, R2, R2
 
 aesloop:
 	AESE	V8.B16,	 V0.B16
@@ -776,8 +913,8 @@ aesloop:
 	AESMC	V6.B16,  V6.B16
 	AESE	V15.B16, V7.B16
 	AESMC	V7.B16,  V7.B16
-	SUB	$1, R1, R1
-	CBNZ	R1, aesloop
+	SUB	$1, R2, R2
+	CBNZ	R2, aesloop
 
 	AESE	V8.B16,	 V0.B16
 	AESMC	V0.B16,  V0.B16
@@ -830,7 +967,11 @@ aesloop:
 	VEOR	V4.B16, V6.B16, V4.B16
 	VEOR	V4.B16, V0.B16, V0.B16
 
-	VST1	[V0.D1], (R2)
+#ifdef GOEXPERIMENT_regabiargs
+	VMOV	V0.D[0], R0
+#else
+	VST1	[V0.D1], (R8)
+#endif
 	RET
 
 TEXT runtime·procyield(SB),NOSPLIT,$0-0
@@ -841,23 +982,6 @@ again:
 	CBNZ	R0, again
 	RET
 
-// void jmpdefer(fv, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 4 bytes to get back to BL deferreturn
-// 3. BR to fn
-TEXT runtime·jmpdefer(SB), NOSPLIT|NOFRAME, $0-16
-	MOVD	0(RSP), R0
-	SUB	$4, R0
-	MOVD	R0, LR
-
-	MOVD	fv+0(FP), R26
-	MOVD	argp+8(FP), R0
-	MOVD	R0, RSP
-	SUB	$8, RSP
-	MOVD	0(R26), R3
-	B	(R3)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
@@ -1052,7 +1176,8 @@ havem:
 	MOVD	R1, 8(RSP)
 	MOVD	R2, 16(RSP)
 	MOVD	R3, 24(RSP)
-	BL	runtime·cgocallbackg(SB)
+	MOVD	$runtime·cgocallbackg(SB), R0
+	CALL	(R0) // indirect call to bypass nosplit check. We're on a different stack now.
 
 	// Restore g->sched (== m->curg->sched) from saved values.
 	MOVD	0(RSP), R5
@@ -1158,7 +1283,10 @@ TEXT ·checkASM(SB),NOSPLIT,$0-1
 // It does not clobber any general-purpose registers,
 // but may clobber others (e.g., floating point registers)
 // The act of CALLing gcWriteBarrier will clobber R30 (LR).
-TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$200
+//
+// Defined as ABIInternal since the compiler generates ABIInternal
+// calls to it directly and it does not use the stack-based Go ABI.
+TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$200
 	// Save the registers clobbered by the fast path.
 	MOVD	R0, 184(RSP)
 	MOVD	R1, 192(RSP)
@@ -1250,71 +1378,129 @@ flush:
 // in the caller's stack frame. These stubs write the args into that stack space and
 // then tail call to the corresponding runtime handler.
 // The tail call makes these stubs disappear in backtraces.
-TEXT runtime·panicIndex(SB),NOSPLIT,$0-16
+//
+// Defined as ABIInternal since the compiler generates ABIInternal
+// calls to it directly and it does not use the stack-based Go ABI.
+TEXT runtime·panicIndex(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicIndex(SB)
-TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicIndex(SB)
+TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicIndexU(SB)
-TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicIndexU(SB)
+TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAlen(SB)
-TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSliceAlen(SB)
+TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAlenU(SB)
-TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSliceAlenU(SB)
+TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAcap(SB)
-TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSliceAcap(SB)
+TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAcapU(SB)
-TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSliceAcapU(SB)
+TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSliceB(SB)
-TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicSliceB(SB)
+TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSliceBU(SB)
-TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicSliceBU(SB)
+TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R2, R0
+	MOVD	R3, R1
+#else
 	MOVD	R2, x+0(FP)
 	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3Alen(SB)
-TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3Alen(SB)
+TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R2, R0
+	MOVD	R3, R1
+#else
 	MOVD	R2, x+0(FP)
 	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3AlenU(SB)
-TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3AlenU(SB)
+TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R2, R0
+	MOVD	R3, R1
+#else
 	MOVD	R2, x+0(FP)
 	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3Acap(SB)
-TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3Acap(SB)
+TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R2, R0
+	MOVD	R3, R1
+#else
 	MOVD	R2, x+0(FP)
 	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3AcapU(SB)
-TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3AcapU(SB)
+TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSlice3B(SB)
-TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3B(SB)
+TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R0
+	MOVD	R2, R1
+#else
 	MOVD	R1, x+0(FP)
 	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSlice3BU(SB)
-TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16
+#endif
+	JMP	runtime·goPanicSlice3BU(SB)
+TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSlice3C(SB)
-TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicSlice3C(SB)
+TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
 	MOVD	R0, x+0(FP)
 	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSlice3CU(SB)
-TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
+	JMP	runtime·goPanicSlice3CU(SB)
+TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R2, R0
+	MOVD	R3, R1
+#else
 	MOVD	R2, x+0(FP)
 	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSliceConvert(SB)
+#endif
+	JMP	runtime·goPanicSliceConvert(SB)
diff --git a/src/runtime/asm_mips64x.s b/src/runtime/asm_mips64x.s
index c3b57e472a2..b2e2384c368 100644
--- a/src/runtime/asm_mips64x.s
+++ b/src/runtime/asm_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
@@ -62,12 +63,11 @@ nocgo:
 
 	// create a new goroutine to start program
 	MOVV	$runtime·mainPC(SB), R1		// entry
-	ADDV	$-24, R29
-	MOVV	R1, 16(R29)
-	MOVV	R0, 8(R29)
+	ADDV	$-16, R29
+	MOVV	R1, 8(R29)
 	MOVV	R0, 0(R29)
 	JAL	runtime·newproc(SB)
-	ADDV	$24, R29
+	ADDV	$16, R29
 
 	// start this M
 	JAL	runtime·mstart(SB)
@@ -384,22 +384,6 @@ CALLFN(·call1073741824, 1073741824)
 TEXT runtime·procyield(SB),NOSPLIT,$0-0
 	RET
 
-// void jmpdefer(fv, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 8 bytes to get back to JAL deferreturn
-// 3. JMP to fn
-TEXT runtime·jmpdefer(SB), NOSPLIT|NOFRAME, $0-16
-	MOVV	0(R29), R31
-	ADDV	$-8, R31
-
-	MOVV	fv+0(FP), REGCTXT
-	MOVV	argp+8(FP), R29
-	ADDV	$-8, R29
-	NOR	R0, R0	// prevent scheduling
-	MOVV	0(REGCTXT), R4
-	JMP	(R4)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
diff --git a/src/runtime/asm_mipsx.s b/src/runtime/asm_mipsx.s
index 1d828b03cfb..87a1344e8f6 100644
--- a/src/runtime/asm_mipsx.s
+++ b/src/runtime/asm_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
@@ -63,12 +64,11 @@ nocgo:
 
 	// create a new goroutine to start program
 	MOVW	$runtime·mainPC(SB), R1	// entry
-	ADDU	$-12, R29
-	MOVW	R1, 8(R29)
-	MOVW	R0, 4(R29)
+	ADDU	$-8, R29
+	MOVW	R1, 4(R29)
 	MOVW	R0, 0(R29)
 	JAL	runtime·newproc(SB)
-	ADDU	$12, R29
+	ADDU	$8, R29
 
 	// start this M
 	JAL	runtime·mstart(SB)
@@ -382,22 +382,6 @@ CALLFN(·call1073741824, 1073741824)
 TEXT runtime·procyield(SB),NOSPLIT,$0-4
 	RET
 
-// void jmpdefer(fv, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 8 bytes to get back to JAL deferreturn
-// 3. JMP to fn
-TEXT runtime·jmpdefer(SB),NOSPLIT,$0-8
-	MOVW	0(R29), R31
-	ADDU	$-8, R31
-
-	MOVW	fv+0(FP), REGCTXT
-	MOVW	argp+4(FP), R29
-	ADDU	$-4, R29
-	NOR	R0, R0	// prevent scheduling
-	MOVW	0(REGCTXT), R4
-	JMP	(R4)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
diff --git a/src/runtime/asm_ppc64x.s b/src/runtime/asm_ppc64x.s
index 2c39b38912f..5dc96c59473 100644
--- a/src/runtime/asm_ppc64x.s
+++ b/src/runtime/asm_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
@@ -93,9 +94,8 @@ nocgo:
 	MOVDU	R0, -8(R1)
 	MOVDU	R0, -8(R1)
 	MOVDU	R0, -8(R1)
-	MOVDU	R0, -8(R1)
 	BL	runtime·newproc(SB)
-	ADD	$(16+FIXED_FRAME), R1
+	ADD	$(8+FIXED_FRAME), R1
 
 	// start this M
 	BL	runtime·mstart(SB)
@@ -503,34 +503,6 @@ again:
 	OR	R6, R6, R6	// Set PPR priority back to medium-low
 	RET
 
-// void jmpdefer(fv, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 8 bytes to get back to either nop or toc reload before deferreturn
-// 3. BR to fn
-// When dynamically linking Go, it is not sufficient to rewind to the BL
-// deferreturn -- we might be jumping between modules and so we need to reset
-// the TOC pointer in r2. To do this, codegen inserts MOVD 24(R1), R2 *before*
-// the BL deferreturn and jmpdefer rewinds to that.
-TEXT runtime·jmpdefer(SB), NOSPLIT|NOFRAME, $0-16
-	MOVD	0(R1), R31
-	SUB     $8, R31
-	MOVD	R31, LR
-
-	MOVD	fv+0(FP), R11
-	MOVD	argp+8(FP), R1
-	SUB	$FIXED_FRAME, R1
-#ifdef GOOS_aix
-	// AIX won't trigger a SIGSEGV if R11 = nil
-	// So it manually triggers it
-	CMP	R0, R11
-	BNE	2(PC)
-	MOVD	R0, 0(R0)
-#endif
-	MOVD	0(R11), R12
-	MOVD	R12, CTR
-	BR	(CTR)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
diff --git a/src/runtime/asm_riscv64.s b/src/runtime/asm_riscv64.s
index ef7af4e10d8..9927a817f72 100644
--- a/src/runtime/asm_riscv64.s
+++ b/src/runtime/asm_riscv64.s
@@ -57,12 +57,11 @@ nocgo:
 
 	// create a new goroutine to start program
 	MOV	$runtime·mainPC(SB), T0		// entry
-	ADD	$-24, X2
-	MOV	T0, 16(X2)
-	MOV	ZERO, 8(X2)
+	ADD	$-16, X2
+	MOV	T0, 8(X2)
 	MOV	ZERO, 0(X2)
 	CALL	runtime·newproc(SB)
-	ADD	$24, X2
+	ADD	$16, X2
 
 	// start this M
 	CALL	runtime·mstart(SB)
@@ -249,21 +248,6 @@ TEXT gogo<>(SB), NOSPLIT|NOFRAME, $0
 	MOV	gobuf_pc(T0), T0
 	JALR	ZERO, T0
 
-// func jmpdefer(fv *funcval, argp uintptr)
-// called from deferreturn
-// 1. grab stored return address from the caller's frame
-// 2. sub 8 bytes to get back to JAL deferreturn
-// 3. JMP to fn
-TEXT runtime·jmpdefer(SB), NOSPLIT|NOFRAME, $0-16
-	MOV	0(X2), RA
-	ADD	$-8, RA
-
-	MOV	fv+0(FP), CTXT
-	MOV	argp+8(FP), X2
-	ADD	$-8, X2
-	MOV	0(CTXT), T0
-	JALR	ZERO, T0
-
 // func procyield(cycles uint32)
 TEXT runtime·procyield(SB),NOSPLIT,$0-0
 	RET
diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
index fb382716303..d4110d563f4 100644
--- a/src/runtime/asm_s390x.s
+++ b/src/runtime/asm_s390x.s
@@ -147,12 +147,11 @@ nocgo:
 
 	// create a new goroutine to start program
 	MOVD	$runtime·mainPC(SB), R2		// entry
-	SUB     $24, R15
-	MOVD 	R2, 16(R15)
-	MOVD 	$0, 8(R15)
+	SUB     $16, R15
+	MOVD 	R2, 8(R15)
 	MOVD 	$0, 0(R15)
 	BL	runtime·newproc(SB)
-	ADD	$24, R15
+	ADD	$16, R15
 
 	// start this M
 	BL	runtime·mstart(SB)
@@ -481,21 +480,6 @@ TEXT callfnMVC<>(SB),NOSPLIT|NOFRAME,$0-0
 TEXT runtime·procyield(SB),NOSPLIT,$0-0
 	RET
 
-// void jmpdefer(fv, sp);
-// called from deferreturn.
-// 1. grab stored LR for caller
-// 2. sub 6 bytes to get back to BL deferreturn (size of BRASL instruction)
-// 3. BR to fn
-TEXT runtime·jmpdefer(SB),NOSPLIT|NOFRAME,$0-16
-	MOVD	0(R15), R1
-	SUB	$6, R1, LR
-
-	MOVD	fv+0(FP), R12
-	MOVD	argp+8(FP), R15
-	SUB	$8, R15
-	MOVD	0(R12), R3
-	BR	(R3)
-
 // Save state of caller into g->sched,
 // but using fake PC from systemstack_switch.
 // Must only be called from functions with no locals ($0)
diff --git a/src/runtime/asm_wasm.s b/src/runtime/asm_wasm.s
index 33c335ba5af..d885da6e70f 100644
--- a/src/runtime/asm_wasm.s
+++ b/src/runtime/asm_wasm.s
@@ -18,8 +18,7 @@ TEXT runtime·rt0_go(SB), NOSPLIT|NOFRAME|TOPFRAME, $0
 	CALLNORESUME runtime·args(SB)
 	CALLNORESUME runtime·osinit(SB)
 	CALLNORESUME runtime·schedinit(SB)
-	MOVD $0, 0(SP)
-	MOVD $runtime·mainPC(SB), 8(SP)
+	MOVD $runtime·mainPC(SB), 0(SP)
 	CALLNORESUME runtime·newproc(SB)
 	CALL runtime·mstart(SB) // WebAssembly stack will unwind when switching to another goroutine
 	UNDEF
@@ -194,35 +193,6 @@ TEXT runtime·return0(SB), NOSPLIT, $0-0
 	MOVD $0, RET0
 	RET
 
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0-16
-	MOVD fv+0(FP), CTXT
-
-	Get CTXT
-	I64Eqz
-	If
-		CALLNORESUME runtime·sigpanic(SB)
-	End
-
-	// caller sp after CALL
-	I64Load argp+8(FP)
-	I64Const $8
-	I64Sub
-	I32WrapI64
-	Set SP
-
-	// decrease PC_B by 1 to CALL again
-	Get SP
-	I32Load16U (SP)
-	I32Const $1
-	I32Sub
-	I32Store16 $0
-
-	// but first run the deferred function
-	Get CTXT
-	I32WrapI64
-	I64Load $0
-	JMP
-
 TEXT runtime·asminit(SB), NOSPLIT, $0-0
 	// No per-thread init.
 	RET
diff --git a/src/runtime/atomic_mips64x.s b/src/runtime/atomic_mips64x.s
index 6f42412502b..e2118e6a20b 100644
--- a/src/runtime/atomic_mips64x.s
+++ b/src/runtime/atomic_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
diff --git a/src/runtime/atomic_mipsx.s b/src/runtime/atomic_mipsx.s
index ed078a2d8a6..1eacd273b44 100644
--- a/src/runtime/atomic_mipsx.s
+++ b/src/runtime/atomic_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/runtime/atomic_ppc64x.s b/src/runtime/atomic_ppc64x.s
index 57f672f3301..b63de2dbd31 100644
--- a/src/runtime/atomic_ppc64x.s
+++ b/src/runtime/atomic_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/runtime/cgo/asm_mips64x.s b/src/runtime/cgo/asm_mips64x.s
index e51cdf3d127..ba948071fa9 100644
--- a/src/runtime/cgo/asm_mips64x.s
+++ b/src/runtime/cgo/asm_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
diff --git a/src/runtime/cgo/asm_mipsx.s b/src/runtime/cgo/asm_mipsx.s
index 1127c8beb48..fd5d78ef97a 100644
--- a/src/runtime/cgo/asm_mipsx.s
+++ b/src/runtime/cgo/asm_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/runtime/cgo/asm_ppc64x.s b/src/runtime/cgo/asm_ppc64x.s
index f4efc1e67d6..187b2d42f63 100644
--- a/src/runtime/cgo/asm_ppc64x.s
+++ b/src/runtime/cgo/asm_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
@@ -11,17 +12,20 @@
 // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
 // Saves C callee-saved registers and calls cgocallback with three arguments.
 // fn is the PC of a func(a unsafe.Pointer) function.
+// The value of R2 is saved on the new stack frame, and not
+// the caller's frame due to issue #43228.
 TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
 	// Start with standard C stack frame layout and linkage
 	MOVD	LR, R0
 	MOVD	R0, 16(R1)	// Save LR in caller's frame
 	MOVW	CR, R0		// Save CR in caller's frame
-	MOVD	R0, 8(R1)
-	MOVD	R2, 24(R1)	// Save TOC in caller's frame
+	MOVW	R0, 8(R1)
 
 	BL	saveregs2<>(SB)
 
 	MOVDU	R1, (-288-3*8-FIXED_FRAME)(R1)
+	// Save the caller's R2
+	MOVD	R2, 24(R1)
 
 	// Initialize Go ABI environment
 	BL	runtime·reginit(SB)
@@ -40,12 +44,13 @@ TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
 	MOVD	R6, FIXED_FRAME+16(R1)	// ctxt uintptr
 	BL	runtime·cgocallback(SB)
 
+	// Restore the caller's R2
+	MOVD	24(R1), R2
 	ADD	$(288+3*8+FIXED_FRAME), R1
 
 	BL	restoreregs2<>(SB)
 
-	MOVD	24(R1), R2
-	MOVD	8(R1), R0
+	MOVW	8(R1), R0
 	MOVFL	R0, $0xff
 	MOVD	16(R1), R0
 	MOVD	R0, LR
diff --git a/src/runtime/cgo/asm_riscv64.s b/src/runtime/cgo/asm_riscv64.s
index b4ddbb020f0..fcd1d36ca84 100644
--- a/src/runtime/cgo/asm_riscv64.s
+++ b/src/runtime/cgo/asm_riscv64.s
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build riscv64
-
 #include "textflag.h"
 
 // Called by C code generated by cmd/cgo.
diff --git a/src/runtime/cgo/gcc_mmap.c b/src/runtime/cgo/gcc_mmap.c
index e6a621d5a37..698a7e3cd24 100644
--- a/src/runtime/cgo/gcc_mmap.c
+++ b/src/runtime/cgo/gcc_mmap.c
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,amd64 linux,arm64
+// +build linux,amd64 linux,arm64 linux,ppc64le
 
 #include 
 #include 
diff --git a/src/runtime/cgo/gcc_sigaction.c b/src/runtime/cgo/gcc_sigaction.c
index 890008e327d..dd283151f17 100644
--- a/src/runtime/cgo/gcc_sigaction.c
+++ b/src/runtime/cgo/gcc_sigaction.c
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,amd64 linux,arm64
+// +build linux,amd64 linux,arm64 linux,ppc64le
 
 #include 
 #include 
diff --git a/src/runtime/cgo/gcc_traceback.c b/src/runtime/cgo/gcc_traceback.c
index d86331c583a..6e9470c43c2 100644
--- a/src/runtime/cgo/gcc_traceback.c
+++ b/src/runtime/cgo/gcc_traceback.c
@@ -7,6 +7,14 @@
 #include 
 #include "libcgo.h"
 
+#ifndef __has_feature
+#define __has_feature(x) 0
+#endif
+
+#if __has_feature(memory_sanitizer)
+#include 
+#endif
+
 // Call the user's traceback function and then call sigtramp.
 // The runtime signal handler will jump to this code.
 // We do it this way so that the user's traceback function will be called
@@ -19,6 +27,18 @@ x_cgo_callers(uintptr_t sig, void *info, void *context, void (*cgoTraceback)(str
 	arg.SigContext = (uintptr_t)(context);
 	arg.Buf = cgoCallers;
 	arg.Max = 32; // must match len(runtime.cgoCallers)
+
+#if __has_feature(memory_sanitizer)
+        // This function is called directly from the signal handler.
+        // The arguments are passed in registers, so whether msan
+        // considers cgoCallers to be initialized depends on whether
+        // it considers the appropriate register to be initialized.
+        // That can cause false reports in rare cases.
+        // Explicitly unpoison the memory to avoid that.
+        // See issue #47543 for more details.
+        __msan_unpoison(&arg, sizeof arg);
+#endif
+
 	(*cgoTraceback)(&arg);
 	sigtramp(sig, info, context);
 }
diff --git a/src/runtime/cgo/sigaction.go b/src/runtime/cgo/sigaction.go
index ee63ea4c09e..692fd2675f9 100644
--- a/src/runtime/cgo/sigaction.go
+++ b/src/runtime/cgo/sigaction.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && amd64) || (freebsd && amd64) || (linux && arm64)
-// +build linux,amd64 freebsd,amd64 linux,arm64
+//go:build (linux && amd64) || (freebsd && amd64) || (linux && arm64) || (linux && ppc64le)
+// +build linux,amd64 freebsd,amd64 linux,arm64 linux,ppc64le
 
 package cgo
 
@@ -11,8 +11,8 @@ package cgo
 import _ "unsafe"
 
 // When using cgo, call the C library for sigaction, so that we call into
-// any sanitizer interceptors. This supports using the memory
-// sanitizer with Go programs. The memory sanitizer only applies to
+// any sanitizer interceptors. This supports using the sanitizers
+// with Go programs. The thread and memory sanitizers only apply to
 // C/C++ code; this permits that code to see the Go runtime's existing signal
 // handlers when registering new signal handlers for the process.
 
diff --git a/src/runtime/cgo_sigaction.go b/src/runtime/cgo_sigaction.go
index 15690ecb0bf..6099d1b746f 100644
--- a/src/runtime/cgo_sigaction.go
+++ b/src/runtime/cgo_sigaction.go
@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Support for memory sanitizer. See runtime/cgo/sigaction.go.
+// Support for sanitizers. See runtime/cgo/sigaction.go.
 
-//go:build (linux && amd64) || (freebsd && amd64) || (linux && arm64)
-// +build linux,amd64 freebsd,amd64 linux,arm64
+//go:build (linux && amd64) || (freebsd && amd64) || (linux && arm64) || (linux && ppc64le)
+// +build linux,amd64 freebsd,amd64 linux,arm64 linux,ppc64le
 
 package runtime
 
diff --git a/src/runtime/cgocall.go b/src/runtime/cgocall.go
index 0e287d0b8ed..2f3c6099076 100644
--- a/src/runtime/cgocall.go
+++ b/src/runtime/cgocall.go
@@ -85,6 +85,7 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -110,6 +111,8 @@ func syscall_cgocaller(fn unsafe.Pointer, args ...uintptr) uintptr {
 	return as.retval
 }
 
+var ncgocall uint64 // number of cgo calls in total for dead m
+
 // Call from Go to C.
 //
 // This must be nosplit because it's used for syscalls on some
@@ -210,6 +213,8 @@ func cgocallbackg(fn, frame unsafe.Pointer, ctxt uintptr) {
 	// a different M. The call to unlockOSThread is in unwindm.
 	lockOSThread()
 
+	checkm := gp.m
+
 	// Save current syscall parameters, so m.syscall can be
 	// used again if callback decide to make syscall.
 	syscall := gp.m.syscall
@@ -225,15 +230,20 @@ func cgocallbackg(fn, frame unsafe.Pointer, ctxt uintptr) {
 
 	osPreemptExtExit(gp.m)
 
-	cgocallbackg1(fn, frame, ctxt)
+	cgocallbackg1(fn, frame, ctxt) // will call unlockOSThread
 
 	// At this point unlockOSThread has been called.
 	// The following code must not change to a different m.
 	// This is enforced by checking incgo in the schedule function.
 
+	gp.m.incgo = true
+
+	if gp.m != checkm {
+		throw("m changed unexpectedly in cgocallbackg")
+	}
+
 	osPreemptExtEnter(gp.m)
 
-	gp.m.incgo = true
 	// going back to cgo call
 	reentersyscall(savedpc, uintptr(savedsp))
 
@@ -242,6 +252,11 @@ func cgocallbackg(fn, frame unsafe.Pointer, ctxt uintptr) {
 
 func cgocallbackg1(fn, frame unsafe.Pointer, ctxt uintptr) {
 	gp := getg()
+
+	// When we return, undo the call to lockOSThread in cgocallbackg.
+	// We must still stay on the same m.
+	defer unlockOSThread()
+
 	if gp.m.needextram || atomic.Load(&extraMWaiters) > 0 {
 		gp.m.needextram = false
 		systemstack(newextram)
@@ -321,10 +336,6 @@ func unwindm(restore *bool) {
 
 		releasem(mp)
 	}
-
-	// Undo the call to lockOSThread in cgocallbackg.
-	// We must still stay on the same m.
-	unlockOSThread()
 }
 
 // called from assembly
@@ -470,7 +481,7 @@ func cgoCheckArg(t *_type, p unsafe.Pointer, indir, top bool, msg string) {
 		if inheap(uintptr(unsafe.Pointer(it))) {
 			panic(errorString(msg))
 		}
-		p = *(*unsafe.Pointer)(add(p, sys.PtrSize))
+		p = *(*unsafe.Pointer)(add(p, goarch.PtrSize))
 		if !cgoIsGoPointer(p) {
 			return
 		}
@@ -550,7 +561,7 @@ func cgoCheckUnknownPointer(p unsafe.Pointer, msg string) (base, i uintptr) {
 		}
 		hbits := heapBitsForAddr(base)
 		n := span.elemsize
-		for i = uintptr(0); i < n; i += sys.PtrSize {
+		for i = uintptr(0); i < n; i += goarch.PtrSize {
 			if !hbits.morePointers() {
 				// No more possible pointers.
 				break
diff --git a/src/runtime/cgocheck.go b/src/runtime/cgocheck.go
index 516045c1633..3acbadf803d 100644
--- a/src/runtime/cgocheck.go
+++ b/src/runtime/cgocheck.go
@@ -8,7 +8,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -151,7 +151,7 @@ func cgoCheckTypedBlock(typ *_type, src unsafe.Pointer, off, size uintptr) {
 	// src must be in the regular heap.
 
 	hbits := heapBitsForAddr(uintptr(src))
-	for i := uintptr(0); i < off+size; i += sys.PtrSize {
+	for i := uintptr(0); i < off+size; i += goarch.PtrSize {
 		bits := hbits.bits()
 		if i >= off && bits&bitPointer != 0 {
 			v := *(*unsafe.Pointer)(add(src, i))
@@ -169,22 +169,22 @@ func cgoCheckTypedBlock(typ *_type, src unsafe.Pointer, off, size uintptr) {
 //go:nosplit
 //go:nowritebarrier
 func cgoCheckBits(src unsafe.Pointer, gcbits *byte, off, size uintptr) {
-	skipMask := off / sys.PtrSize / 8
-	skipBytes := skipMask * sys.PtrSize * 8
+	skipMask := off / goarch.PtrSize / 8
+	skipBytes := skipMask * goarch.PtrSize * 8
 	ptrmask := addb(gcbits, skipMask)
 	src = add(src, skipBytes)
 	off -= skipBytes
 	size += off
 	var bits uint32
-	for i := uintptr(0); i < size; i += sys.PtrSize {
-		if i&(sys.PtrSize*8-1) == 0 {
+	for i := uintptr(0); i < size; i += goarch.PtrSize {
+		if i&(goarch.PtrSize*8-1) == 0 {
 			bits = uint32(*ptrmask)
 			ptrmask = addb(ptrmask, 1)
 		} else {
 			bits >>= 1
 		}
 		if off > 0 {
-			off -= sys.PtrSize
+			off -= goarch.PtrSize
 		} else {
 			if bits&1 != 0 {
 				v := *(*unsafe.Pointer)(add(src, i))
diff --git a/src/runtime/chan.go b/src/runtime/chan.go
index f2a75b30f44..3cdb5dce117 100644
--- a/src/runtime/chan.go
+++ b/src/runtime/chan.go
@@ -18,6 +18,7 @@ package runtime
 //  c.qcount < c.dataqsiz implies that c.sendq is empty.
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"runtime/internal/math"
 	"unsafe"
@@ -169,7 +170,7 @@ func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {
 	}
 
 	if raceenabled {
-		racereadpc(c.raceaddr(), callerpc, funcPC(chansend))
+		racereadpc(c.raceaddr(), callerpc, abi.FuncPCABIInternal(chansend))
 	}
 
 	// Fast path: check for failed non-blocking operation without acquiring the lock.
@@ -365,7 +366,7 @@ func closechan(c *hchan) {
 
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(c.raceaddr(), callerpc, funcPC(closechan))
+		racewritepc(c.raceaddr(), callerpc, abi.FuncPCABIInternal(closechan))
 		racerelease(c.raceaddr())
 	}
 
diff --git a/src/runtime/checkptr.go b/src/runtime/checkptr.go
index 59891a06a56..2d4afd5cf68 100644
--- a/src/runtime/checkptr.go
+++ b/src/runtime/checkptr.go
@@ -7,6 +7,11 @@ package runtime
 import "unsafe"
 
 func checkptrAlignment(p unsafe.Pointer, elem *_type, n uintptr) {
+	// nil pointer is always suitably aligned (#47430).
+	if p == nil {
+		return
+	}
+
 	// Check that (*[n]elem)(p) is appropriately aligned.
 	// Note that we allow unaligned pointers if the types they point to contain
 	// no pointers themselves. See issue 37298.
@@ -16,11 +21,32 @@ func checkptrAlignment(p unsafe.Pointer, elem *_type, n uintptr) {
 	}
 
 	// Check that (*[n]elem)(p) doesn't straddle multiple heap objects.
-	if size := n * elem.size; size > 1 && checkptrBase(p) != checkptrBase(add(p, size-1)) {
+	// TODO(mdempsky): Fix #46938 so we don't need to worry about overflow here.
+	if checkptrStraddles(p, n*elem.size) {
 		throw("checkptr: converted pointer straddles multiple allocations")
 	}
 }
 
+// checkptrStraddles reports whether the first size-bytes of memory
+// addressed by ptr is known to straddle more than one Go allocation.
+func checkptrStraddles(ptr unsafe.Pointer, size uintptr) bool {
+	if size <= 1 {
+		return false
+	}
+
+	// Check that add(ptr, size-1) won't overflow. This avoids the risk
+	// of producing an illegal pointer value (assuming ptr is legal).
+	if uintptr(ptr) >= -(size - 1) {
+		return true
+	}
+	end := add(ptr, size-1)
+
+	// TODO(mdempsky): Detect when [ptr, end] contains Go allocations,
+	// but neither ptr nor end point into one themselves.
+
+	return checkptrBase(ptr) != checkptrBase(end)
+}
+
 func checkptrArithmetic(p unsafe.Pointer, originals []unsafe.Pointer) {
 	if 0 < uintptr(p) && uintptr(p) < minLegalPointer {
 		throw("checkptr: pointer arithmetic computed bad pointer value")
diff --git a/src/runtime/checkptr_test.go b/src/runtime/checkptr_test.go
index 194cc1243a9..d5dd101adbe 100644
--- a/src/runtime/checkptr_test.go
+++ b/src/runtime/checkptr_test.go
@@ -26,10 +26,13 @@ func TestCheckPtr(t *testing.T) {
 	}{
 		{"CheckPtrAlignmentPtr", "fatal error: checkptr: misaligned pointer conversion\n"},
 		{"CheckPtrAlignmentNoPtr", ""},
+		{"CheckPtrAlignmentNilPtr", ""},
 		{"CheckPtrArithmetic", "fatal error: checkptr: pointer arithmetic result points to invalid allocation\n"},
 		{"CheckPtrArithmetic2", "fatal error: checkptr: pointer arithmetic result points to invalid allocation\n"},
 		{"CheckPtrSize", "fatal error: checkptr: converted pointer straddles multiple allocations\n"},
 		{"CheckPtrSmall", "fatal error: checkptr: pointer arithmetic computed bad pointer value\n"},
+		{"CheckPtrSliceOK", ""},
+		{"CheckPtrSliceFail", "fatal error: checkptr: unsafe.Slice result straddles multiple allocations\n"},
 	}
 
 	for _, tc := range testCases {
diff --git a/src/runtime/cpuprof.go b/src/runtime/cpuprof.go
index e5d0193b9cb..c81ab710c20 100644
--- a/src/runtime/cpuprof.go
+++ b/src/runtime/cpuprof.go
@@ -13,6 +13,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -166,8 +167,8 @@ func (p *cpuProfile) addExtra() {
 	if p.lostExtra > 0 {
 		hdr := [1]uint64{p.lostExtra}
 		lostStk := [2]uintptr{
-			funcPC(_LostExternalCode) + sys.PCQuantum,
-			funcPC(_ExternalCode) + sys.PCQuantum,
+			abi.FuncPCABIInternal(_LostExternalCode) + sys.PCQuantum,
+			abi.FuncPCABIInternal(_ExternalCode) + sys.PCQuantum,
 		}
 		p.log.write(nil, 0, hdr[:], lostStk[:])
 		p.lostExtra = 0
@@ -176,8 +177,8 @@ func (p *cpuProfile) addExtra() {
 	if p.lostAtomic > 0 {
 		hdr := [1]uint64{p.lostAtomic}
 		lostStk := [2]uintptr{
-			funcPC(_LostSIGPROFDuringAtomic64) + sys.PCQuantum,
-			funcPC(_System) + sys.PCQuantum,
+			abi.FuncPCABIInternal(_LostSIGPROFDuringAtomic64) + sys.PCQuantum,
+			abi.FuncPCABIInternal(_System) + sys.PCQuantum,
 		}
 		p.log.write(nil, 0, hdr[:], lostStk[:])
 		p.lostAtomic = 0
diff --git a/src/runtime/crash_cgo_test.go b/src/runtime/crash_cgo_test.go
index 7d25c51aa2a..5729942cee3 100644
--- a/src/runtime/crash_cgo_test.go
+++ b/src/runtime/crash_cgo_test.go
@@ -282,6 +282,15 @@ func TestCgoTracebackContext(t *testing.T) {
 	}
 }
 
+func TestCgoTracebackContextPreemption(t *testing.T) {
+	t.Parallel()
+	got := runTestProg(t, "testprogcgo", "TracebackContextPreemption")
+	want := "OK\n"
+	if got != want {
+		t.Errorf("expected %q got %v", want, got)
+	}
+}
+
 func testCgoPprof(t *testing.T, buildArg, runArg, top, bottom string) {
 	t.Parallel()
 	if runtime.GOOS != "linux" || (runtime.GOARCH != "amd64" && runtime.GOARCH != "ppc64le") {
diff --git a/src/runtime/crash_test.go b/src/runtime/crash_test.go
index e5bd7973b70..e0c0bac8926 100644
--- a/src/runtime/crash_test.go
+++ b/src/runtime/crash_test.go
@@ -470,14 +470,6 @@ func TestRecoverBeforePanicAfterGoexit2(t *testing.T) {
 }
 
 func TestNetpollDeadlock(t *testing.T) {
-	if os.Getenv("GO_BUILDER_NAME") == "darwin-amd64-10_12" {
-		// A suspected kernel bug in macOS 10.12 occasionally results in
-		// an apparent deadlock when dialing localhost. The errors have not
-		// been observed on newer versions of the OS, so we don't plan to work
-		// around them. See https://golang.org/issue/22019.
-		testenv.SkipFlaky(t, 22019)
-	}
-
 	t.Parallel()
 	output := runTestProg(t, "testprognet", "NetpollDeadlock")
 	want := "done\n"
diff --git a/src/runtime/crash_unix_test.go b/src/runtime/crash_unix_test.go
index 9469d5e6a64..694cc3d138b 100644
--- a/src/runtime/crash_unix_test.go
+++ b/src/runtime/crash_unix_test.go
@@ -69,7 +69,8 @@ func TestCrashDumpsAllThreads(t *testing.T) {
 		t.Skipf("skipping; not supported on %v", runtime.GOOS)
 	}
 
-	if runtime.GOOS == "openbsd" && runtime.GOARCH == "mips64" {
+	if runtime.GOOS == "openbsd" && (runtime.GOARCH == "arm" || runtime.GOARCH == "mips64") {
+		// This may be ncpu < 2 related...
 		t.Skipf("skipping; test fails on %s/%s - see issue #42464", runtime.GOOS, runtime.GOARCH)
 	}
 
diff --git a/src/runtime/debug.go b/src/runtime/debug.go
index f411b226766..82deefa200c 100644
--- a/src/runtime/debug.go
+++ b/src/runtime/debug.go
@@ -45,7 +45,7 @@ func NumCPU() int {
 
 // NumCgoCall returns the number of cgo calls made by the current process.
 func NumCgoCall() int64 {
-	var n int64
+	var n = int64(atomic.Load64(&ncgocall))
 	for mp := (*m)(atomic.Loadp(unsafe.Pointer(&allm))); mp != nil; mp = mp.alllink {
 		n += int64(mp.ncgocall)
 	}
diff --git a/src/runtime/debug/panic_test.go b/src/runtime/debug/panic_test.go
index b93631e1d83..65f9555f376 100644
--- a/src/runtime/debug/panic_test.go
+++ b/src/runtime/debug/panic_test.go
@@ -24,6 +24,9 @@ func TestPanicOnFault(t *testing.T) {
 	if runtime.GOOS == "ios" {
 		t.Skip("iOS doesn't provide fault addresses")
 	}
+	if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm" {
+		t.Skip("netbsd-arm doesn't provide fault address (golang.org/issue/45026)")
+	}
 	m, err := syscall.Mmap(-1, 0, 0x1000, syscall.PROT_READ /* Note: no PROT_WRITE */, syscall.MAP_SHARED|syscall.MAP_ANON)
 	if err != nil {
 		t.Fatalf("can't map anonymous memory: %s", err)
diff --git a/src/runtime/debugcall.go b/src/runtime/debugcall.go
index faddf59eed6..ad66a18c26c 100644
--- a/src/runtime/debugcall.go
+++ b/src/runtime/debugcall.go
@@ -112,7 +112,7 @@ func debugCallWrap(dispatch uintptr) {
 		// closure and start the goroutine with that closure, but the compiler disallows
 		// implicit closure allocation in the runtime.
 		fn := debugCallWrap1
-		newg := newproc1(*(**funcval)(unsafe.Pointer(&fn)), nil, 0, gp, callerpc)
+		newg := newproc1(*(**funcval)(unsafe.Pointer(&fn)), gp, callerpc)
 		args := &debugCallWrapArgs{
 			dispatch: dispatch,
 			callingG: gp,
diff --git a/src/runtime/defs_openbsd_arm.go b/src/runtime/defs_openbsd_arm.go
index 170bb3876c4..6f128c4284b 100644
--- a/src/runtime/defs_openbsd_arm.go
+++ b/src/runtime/defs_openbsd_arm.go
@@ -30,6 +30,13 @@ const (
 	_SA_RESTART = 0x2
 	_SA_ONSTACK = 0x1
 
+	_PTHREAD_CREATE_DETACHED = 0x1
+
+	_F_SETFD    = 0x2
+	_F_GETFL    = 0x3
+	_F_SETFL    = 0x4
+	_FD_CLOEXEC = 0x1
+
 	_SIGHUP    = 0x1
 	_SIGINT    = 0x2
 	_SIGQUIT   = 0x3
@@ -174,3 +181,10 @@ type keventt struct {
 	udata     *byte
 	pad_cgo_1 [4]byte
 }
+
+type pthread uintptr
+type pthreadattr uintptr
+type pthreadcond uintptr
+type pthreadcondattr uintptr
+type pthreadmutex uintptr
+type pthreadmutexattr uintptr
diff --git a/src/runtime/defs_plan9_386.go b/src/runtime/defs_plan9_386.go
index 49129b3c3fc..428044df687 100644
--- a/src/runtime/defs_plan9_386.go
+++ b/src/runtime/defs_plan9_386.go
@@ -61,4 +61,4 @@ func dumpregs(u *ureg) {
 	print("gs    ", hex(u.gs), "\n")
 }
 
-func sigpanictramp() {}
+func sigpanictramp()
diff --git a/src/runtime/defs_plan9_amd64.go b/src/runtime/defs_plan9_amd64.go
index 00995630341..15a27fc7db9 100644
--- a/src/runtime/defs_plan9_amd64.go
+++ b/src/runtime/defs_plan9_amd64.go
@@ -78,4 +78,4 @@ func dumpregs(u *ureg) {
 	print("gs    ", hex(u.gs), "\n")
 }
 
-func sigpanictramp() {}
+func sigpanictramp()
diff --git a/src/runtime/duff_arm64.s b/src/runtime/duff_arm64.s
index 128b076af9d..33c4905078d 100644
--- a/src/runtime/duff_arm64.s
+++ b/src/runtime/duff_arm64.s
@@ -4,7 +4,7 @@
 
 #include "textflag.h"
 
-TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0
+TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0
 	STP.P	(ZR, ZR), 16(R20)
 	STP.P	(ZR, ZR), 16(R20)
 	STP.P	(ZR, ZR), 16(R20)
@@ -71,7 +71,7 @@ TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0
 	STP	(ZR, ZR), (R20)
 	RET
 
-TEXT runtime·duffcopy(SB), NOSPLIT|NOFRAME, $0-0
+TEXT runtime·duffcopy(SB), NOSPLIT|NOFRAME, $0-0
 	LDP.P	16(R20), (R26, R27)
 	STP.P	(R26, R27), 16(R21)
 
diff --git a/src/runtime/duff_mips64x.s b/src/runtime/duff_mips64x.s
index c4e04ccc9da..a897d7fd9bf 100644
--- a/src/runtime/duff_mips64x.s
+++ b/src/runtime/duff_mips64x.s
@@ -2,6 +2,7 @@
 // Run go generate from src/runtime to update.
 // See mkduff.go for comments.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
diff --git a/src/runtime/duff_ppc64x.s b/src/runtime/duff_ppc64x.s
index d6b89ba9401..d4e3b409d24 100644
--- a/src/runtime/duff_ppc64x.s
+++ b/src/runtime/duff_ppc64x.s
@@ -2,6 +2,7 @@
 // Run go generate from src/runtime to update.
 // See mkduff.go for comments.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/runtime/example_test.go b/src/runtime/example_test.go
index e4912a51588..dcb8f7798e2 100644
--- a/src/runtime/example_test.go
+++ b/src/runtime/example_test.go
@@ -12,12 +12,15 @@ import (
 
 func ExampleFrames() {
 	c := func() {
-		// Ask runtime.Callers for up to 10 pcs, including runtime.Callers itself.
+		// Ask runtime.Callers for up to 10 PCs, including runtime.Callers itself.
 		pc := make([]uintptr, 10)
 		n := runtime.Callers(0, pc)
 		if n == 0 {
-			// No pcs available. Stop now.
-			// This can happen if the first argument to runtime.Callers is large.
+			// No PCs available. This can happen if the first argument to
+			// runtime.Callers is large.
+			//
+			// Return now to avoid processing the zero Frame that would
+			// otherwise be returned by frames.Next below.
 			return
 		}
 
@@ -25,9 +28,12 @@ func ExampleFrames() {
 		frames := runtime.CallersFrames(pc)
 
 		// Loop to get frames.
-		// A fixed number of pcs can expand to an indefinite number of Frames.
+		// A fixed number of PCs can expand to an indefinite number of Frames.
 		for {
 			frame, more := frames.Next()
+
+			// Process this frame.
+			//
 			// To keep this example's output stable
 			// even if there are changes in the testing package,
 			// stop unwinding when we leave package runtime.
@@ -35,6 +41,8 @@ func ExampleFrames() {
 				break
 			}
 			fmt.Printf("- more:%v | %s\n", more, frame.Function)
+
+			// Check whether there are more frames to process after this one.
 			if !more {
 				break
 			}
diff --git a/src/runtime/export_debug_regabiargs_off_test.go b/src/runtime/export_debug_regabiargs_off_test.go
index fce37ab4d19..5009003d27d 100644
--- a/src/runtime/export_debug_regabiargs_off_test.go
+++ b/src/runtime/export_debug_regabiargs_off_test.go
@@ -3,8 +3,7 @@
 // license that can be found in the LICENSE file.
 
 //go:build amd64 && linux && !goexperiment.regabiargs
-// +build amd64,linux
-// +build !goexperiment.regabiargs
+// +build amd64,linux,!goexperiment.regabiargs
 
 package runtime
 
diff --git a/src/runtime/export_debug_regabiargs_on_test.go b/src/runtime/export_debug_regabiargs_on_test.go
index 3c65127e560..e1b72efd0f7 100644
--- a/src/runtime/export_debug_regabiargs_on_test.go
+++ b/src/runtime/export_debug_regabiargs_on_test.go
@@ -3,8 +3,7 @@
 // license that can be found in the LICENSE file.
 
 //go:build amd64 && linux && goexperiment.regabiargs
-// +build amd64,linux
-// +build goexperiment.regabiargs
+// +build amd64,linux,goexperiment.regabiargs
 
 package runtime
 
diff --git a/src/runtime/export_debug_test.go b/src/runtime/export_debug_test.go
index fe4c9045c10..a2cef02cf86 100644
--- a/src/runtime/export_debug_test.go
+++ b/src/runtime/export_debug_test.go
@@ -9,7 +9,7 @@ package runtime
 
 import (
 	"internal/abi"
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -115,7 +115,7 @@ func (h *debugCallHandler) inject(info *siginfo, ctxt *sigctxt, gp2 *g) bool {
 			return false
 		}
 		// Push current PC on the stack.
-		rsp := ctxt.rsp() - sys.PtrSize
+		rsp := ctxt.rsp() - goarch.PtrSize
 		*(*uint64)(unsafe.Pointer(uintptr(rsp))) = ctxt.rip()
 		ctxt.set_rsp(rsp)
 		// Write the argument frame size.
@@ -125,7 +125,7 @@ func (h *debugCallHandler) inject(info *siginfo, ctxt *sigctxt, gp2 *g) bool {
 		h.savedFP = *h.savedRegs.fpstate
 		h.savedRegs.fpstate = nil
 		// Set PC to debugCallV2.
-		ctxt.set_rip(uint64(funcPC(debugCallV2)))
+		ctxt.set_rip(uint64(abi.FuncPCABIInternal(debugCallV2)))
 		// Call injected. Switch to the debugCall protocol.
 		testSigtrap = h.handleF
 	case _Grunnable:
@@ -166,7 +166,7 @@ func (h *debugCallHandler) handle(info *siginfo, ctxt *sigctxt, gp2 *g) bool {
 			storeRegArgs(ctxt.regs(), h.regArgs)
 		}
 		// Push return PC.
-		sp -= sys.PtrSize
+		sp -= goarch.PtrSize
 		ctxt.set_rsp(sp)
 		*(*uint64)(unsafe.Pointer(uintptr(sp))) = ctxt.rip()
 		// Set PC to call and context register.
@@ -182,7 +182,7 @@ func (h *debugCallHandler) handle(info *siginfo, ctxt *sigctxt, gp2 *g) bool {
 	case 2:
 		// Function panicked. Copy panic out.
 		sp := ctxt.rsp()
-		memmove(unsafe.Pointer(&h.panic), unsafe.Pointer(uintptr(sp)), 2*sys.PtrSize)
+		memmove(unsafe.Pointer(&h.panic), unsafe.Pointer(uintptr(sp)), 2*goarch.PtrSize)
 	case 8:
 		// Call isn't safe. Get the reason.
 		sp := ctxt.rsp()
diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index a6fc1e4785f..e7279564e3f 100644
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -7,6 +7,8 @@
 package runtime
 
 import (
+	"internal/goarch"
+	"internal/goos"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -27,8 +29,6 @@ var Exitsyscall = exitsyscall
 var LockedOSThread = lockedOSThread
 var Xadduintptr = atomic.Xadduintptr
 
-var FuncPC = funcPC
-
 var Fastlog2 = fastlog2
 
 var Atoi = atoi
@@ -147,40 +147,28 @@ func RunSchedLocalQueueStealTest() {
 	}
 }
 
-// Temporary to enable register ABI bringup.
-// TODO(register args): convert back to local variables in RunSchedLocalQueueEmptyTest that
-// get passed to the "go" stmts there.
-var RunSchedLocalQueueEmptyState struct {
-	done  chan bool
-	ready *uint32
-	p     *p
-}
-
 func RunSchedLocalQueueEmptyTest(iters int) {
 	// Test that runq is not spuriously reported as empty.
 	// Runq emptiness affects scheduling decisions and spurious emptiness
 	// can lead to underutilization (both runnable Gs and idle Ps coexist
 	// for arbitrary long time).
 	done := make(chan bool, 1)
-	RunSchedLocalQueueEmptyState.done = done
 	p := new(p)
-	RunSchedLocalQueueEmptyState.p = p
 	gs := make([]g, 2)
 	ready := new(uint32)
-	RunSchedLocalQueueEmptyState.ready = ready
 	for i := 0; i < iters; i++ {
 		*ready = 0
 		next0 := (i & 1) == 0
 		next1 := (i & 2) == 0
 		runqput(p, &gs[0], next0)
 		go func() {
-			for atomic.Xadd(RunSchedLocalQueueEmptyState.ready, 1); atomic.Load(RunSchedLocalQueueEmptyState.ready) != 2; {
+			for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
 			}
-			if runqempty(RunSchedLocalQueueEmptyState.p) {
-				//println("next:", next0, next1)
+			if runqempty(p) {
+				println("next:", next0, next1)
 				throw("queue is empty")
 			}
-			RunSchedLocalQueueEmptyState.done <- true
+			done <- true
 		}()
 		for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
 		}
@@ -228,8 +216,6 @@ var Write = write
 func Envs() []string     { return envs }
 func SetEnvs(e []string) { envs = e }
 
-var BigEndian = sys.BigEndian
-
 // For benchmarking.
 
 func BenchSetType(n int, x interface{}) {
@@ -259,7 +245,7 @@ func BenchSetType(n int, x interface{}) {
 	})
 }
 
-const PtrSize = sys.PtrSize
+const PtrSize = goarch.PtrSize
 
 var ForceGCPeriod = &forcegcperiod
 
@@ -1066,7 +1052,7 @@ func FreePageAlloc(pp *PageAlloc) {
 //
 // This should not be higher than 0x100*pallocChunkBytes to support
 // mips and mipsle, which only have 31-bit address spaces.
-var BaseChunkIdx = ChunkIdx(chunkIndex(((0xc000*pageAlloc64Bit + 0x100*pageAlloc32Bit) * pallocChunkBytes) + arenaBaseOffset*sys.GoosAix))
+var BaseChunkIdx = ChunkIdx(chunkIndex(((0xc000*pageAlloc64Bit + 0x100*pageAlloc32Bit) * pallocChunkBytes) + arenaBaseOffset*goos.IsAix))
 
 // PageBase returns an address given a chunk index and a page index
 // relative to that chunk.
@@ -1148,31 +1134,6 @@ func SemNwait(addr *uint32) uint32 {
 	return atomic.Load(&root.nwait)
 }
 
-// MapHashCheck computes the hash of the key k for the map m, twice.
-// Method 1 uses the built-in hasher for the map.
-// Method 2 uses the typehash function (the one used by reflect).
-// Returns the two hash values, which should always be equal.
-func MapHashCheck(m interface{}, k interface{}) (uintptr, uintptr) {
-	// Unpack m.
-	mt := (*maptype)(unsafe.Pointer(efaceOf(&m)._type))
-	mh := (*hmap)(efaceOf(&m).data)
-
-	// Unpack k.
-	kt := efaceOf(&k)._type
-	var p unsafe.Pointer
-	if isDirectIface(kt) {
-		q := efaceOf(&k).data
-		p = unsafe.Pointer(&q)
-	} else {
-		p = efaceOf(&k).data
-	}
-
-	// Compute the hash functions.
-	x := mt.hasher(noescape(p), uintptr(mh.hash0))
-	y := typehash(kt, noescape(p), uintptr(mh.hash0))
-	return x, y
-}
-
 // mspan wrapper for testing.
 //go:notinheap
 type MSpan mspan
diff --git a/src/runtime/extern.go b/src/runtime/extern.go
index 48e1e6603b7..eca4062e68c 100644
--- a/src/runtime/extern.go
+++ b/src/runtime/extern.go
@@ -186,7 +186,10 @@ of the run-time system.
 */
 package runtime
 
-import "runtime/internal/sys"
+import (
+	"internal/goarch"
+	"internal/goos"
+)
 
 // Caller reports file and line number information about function invocations on
 // the calling goroutine's stack. The argument skip is the number of stack frames
@@ -260,8 +263,8 @@ func Version() string {
 // GOOS is the running program's operating system target:
 // one of darwin, freebsd, linux, and so on.
 // To view possible combinations of GOOS and GOARCH, run "go tool dist list".
-const GOOS string = sys.GOOS
+const GOOS string = goos.GOOS
 
 // GOARCH is the running program's architecture target:
 // one of 386, amd64, arm, s390x, and so on.
-const GOARCH string = sys.GOARCH
+const GOARCH string = goarch.GOARCH
diff --git a/src/runtime/gc_test.go b/src/runtime/gc_test.go
index 5e7c6c574fe..0ec53315348 100644
--- a/src/runtime/gc_test.go
+++ b/src/runtime/gc_test.go
@@ -21,6 +21,7 @@ import (
 )
 
 func TestGcSys(t *testing.T) {
+	t.Skip("skipping known-flaky test; golang.org/issue/37331")
 	if os.Getenv("GOGC") == "off" {
 		t.Skip("skipping test; GOGC=off in environment")
 	}
diff --git a/src/runtime/hash_test.go b/src/runtime/hash_test.go
index 502383557b8..7048874a71f 100644
--- a/src/runtime/hash_test.go
+++ b/src/runtime/hash_test.go
@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
-	"reflect"
 	. "runtime"
 	"strings"
 	"testing"
@@ -49,54 +48,6 @@ func TestMemHash64Equality(t *testing.T) {
 	}
 }
 
-func TestCompilerVsRuntimeHash(t *testing.T) {
-	// Test to make sure the compiler's hash function and the runtime's hash function agree.
-	// See issue 37716.
-	for _, m := range []interface{}{
-		map[bool]int{},
-		map[int8]int{},
-		map[uint8]int{},
-		map[int16]int{},
-		map[uint16]int{},
-		map[int32]int{},
-		map[uint32]int{},
-		map[int64]int{},
-		map[uint64]int{},
-		map[int]int{},
-		map[uint]int{},
-		map[uintptr]int{},
-		map[*byte]int{},
-		map[chan int]int{},
-		map[unsafe.Pointer]int{},
-		map[float32]int{},
-		map[float64]int{},
-		map[complex64]int{},
-		map[complex128]int{},
-		map[string]int{},
-		//map[interface{}]int{},
-		//map[interface{F()}]int{},
-		map[[8]uint64]int{},
-		map[[8]string]int{},
-		map[struct{ a, b, c, d int32 }]int{}, // Note: tests AMEM128
-		map[struct{ a, b, _, d int32 }]int{},
-		map[struct {
-			a, b int32
-			c    float32
-			d, e [8]byte
-		}]int{},
-		map[struct {
-			a int16
-			b int64
-		}]int{},
-	} {
-		k := reflect.New(reflect.TypeOf(m).Key()).Elem().Interface() // the zero key
-		x, y := MapHashCheck(m, k)
-		if x != y {
-			t.Errorf("hashes did not match (%x vs %x) for map %T", x, y, m)
-		}
-	}
-}
-
 // Smhasher is a torture test for hash functions.
 // https://code.google.com/p/smhasher/
 // This code is a port of some of the Smhasher tests to Go.
diff --git a/src/runtime/heapdump.go b/src/runtime/heapdump.go
index 934e55f4952..8fb30d95b9b 100644
--- a/src/runtime/heapdump.go
+++ b/src/runtime/heapdump.go
@@ -12,7 +12,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -247,7 +247,7 @@ func dumpbv(cbv *bitvector, offset uintptr) {
 	for i := uintptr(0); i < uintptr(cbv.n); i++ {
 		if cbv.ptrbit(i) == 1 {
 			dumpint(fieldKindPtr)
-			dumpint(uint64(offset + i*sys.PtrSize))
+			dumpint(uint64(offset + i*goarch.PtrSize))
 		}
 	}
 }
@@ -298,7 +298,7 @@ func dumpframe(s *stkframe, arg unsafe.Pointer) bool {
 		dumpbv(&child.args, child.argoff)
 	} else {
 		// conservative - everything might be a pointer
-		for off := child.argoff; off < child.argoff+child.arglen; off += sys.PtrSize {
+		for off := child.argoff; off < child.argoff+child.arglen; off += goarch.PtrSize {
 			dumpint(fieldKindPtr)
 			dumpint(uint64(off))
 		}
@@ -307,21 +307,21 @@ func dumpframe(s *stkframe, arg unsafe.Pointer) bool {
 	// Dump fields in the local vars section
 	if stkmap == nil {
 		// No locals information, dump everything.
-		for off := child.arglen; off < s.varp-s.sp; off += sys.PtrSize {
+		for off := child.arglen; off < s.varp-s.sp; off += goarch.PtrSize {
 			dumpint(fieldKindPtr)
 			dumpint(uint64(off))
 		}
 	} else if stkmap.n < 0 {
 		// Locals size information, dump just the locals.
 		size := uintptr(-stkmap.n)
-		for off := s.varp - size - s.sp; off < s.varp-s.sp; off += sys.PtrSize {
+		for off := s.varp - size - s.sp; off < s.varp-s.sp; off += goarch.PtrSize {
 			dumpint(fieldKindPtr)
 			dumpint(uint64(off))
 		}
 	} else if stkmap.n > 0 {
 		// Locals bitmap information, scan just the pointers in
 		// locals.
-		dumpbv(&bv, s.varp-uintptr(bv.n)*sys.PtrSize-s.sp)
+		dumpbv(&bv, s.varp-uintptr(bv.n)*goarch.PtrSize-s.sp)
 	}
 	dumpint(fieldKindEol)
 
@@ -381,12 +381,13 @@ func dumpgoroutine(gp *g) {
 		dumpint(uint64(uintptr(unsafe.Pointer(gp))))
 		dumpint(uint64(d.sp))
 		dumpint(uint64(d.pc))
-		dumpint(uint64(uintptr(unsafe.Pointer(d.fn))))
+		fn := *(**funcval)(unsafe.Pointer(&d.fn))
+		dumpint(uint64(uintptr(unsafe.Pointer(fn))))
 		if d.fn == nil {
 			// d.fn can be nil for open-coded defers
 			dumpint(uint64(0))
 		} else {
-			dumpint(uint64(uintptr(unsafe.Pointer(d.fn.fn))))
+			dumpint(uint64(uintptr(unsafe.Pointer(fn.fn))))
 		}
 		dumpint(uint64(uintptr(unsafe.Pointer(d.link))))
 	}
@@ -510,7 +511,7 @@ func dumpparams() {
 	} else {
 		dumpbool(true) // big-endian ptrs
 	}
-	dumpint(sys.PtrSize)
+	dumpint(goarch.PtrSize)
 	var arenaStart, arenaEnd uintptr
 	for i1 := range mheap_.arenas {
 		if mheap_.arenas[i1] == nil {
@@ -531,7 +532,7 @@ func dumpparams() {
 	}
 	dumpint(uint64(arenaStart))
 	dumpint(uint64(arenaEnd))
-	dumpstr(sys.GOARCH)
+	dumpstr(goarch.GOARCH)
 	dumpstr(buildVersion)
 	dumpint(uint64(ncpu))
 }
@@ -725,7 +726,7 @@ func dumpfields(bv bitvector) {
 
 func makeheapobjbv(p uintptr, size uintptr) bitvector {
 	// Extend the temp buffer if necessary.
-	nptr := size / sys.PtrSize
+	nptr := size / goarch.PtrSize
 	if uintptr(len(tmpbuf)) < nptr/8+1 {
 		if tmpbuf != nil {
 			sysFree(unsafe.Pointer(&tmpbuf[0]), uintptr(len(tmpbuf)), &memstats.other_sys)
diff --git a/src/runtime/iface.go b/src/runtime/iface.go
index cd5fead9990..3d1d9d6ba18 100644
--- a/src/runtime/iface.go
+++ b/src/runtime/iface.go
@@ -5,8 +5,9 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -63,7 +64,7 @@ func getitab(inter *interfacetype, typ *_type, canfail bool) *itab {
 	}
 
 	// Entry doesn't exist yet. Make a new entry & add it.
-	m = (*itab)(persistentalloc(unsafe.Sizeof(itab{})+uintptr(len(inter.mhdr)-1)*sys.PtrSize, 0, &memstats.other_sys))
+	m = (*itab)(persistentalloc(unsafe.Sizeof(itab{})+uintptr(len(inter.mhdr)-1)*goarch.PtrSize, 0, &memstats.other_sys))
 	m.inter = inter
 	m._type = typ
 	// The hash is used in type switches. However, compiler statically generates itab's
@@ -100,7 +101,7 @@ func (t *itabTableType) find(inter *interfacetype, typ *_type) *itab {
 	mask := t.size - 1
 	h := itabHashFunc(inter, typ) & mask
 	for i := uintptr(1); ; i++ {
-		p := (**itab)(add(unsafe.Pointer(&t.entries), h*sys.PtrSize))
+		p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize))
 		// Use atomic read here so if we see m != nil, we also see
 		// the initializations of the fields of m.
 		// m := *p
@@ -133,7 +134,7 @@ func itabAdd(m *itab) {
 		// t2 = new(itabTableType) + some additional entries
 		// We lie and tell malloc we want pointer-free memory because
 		// all the pointed-to values are not in the heap.
-		t2 := (*itabTableType)(mallocgc((2+2*t.size)*sys.PtrSize, nil, true))
+		t2 := (*itabTableType)(mallocgc((2+2*t.size)*goarch.PtrSize, nil, true))
 		t2.size = t.size * 2
 
 		// Copy over entries.
@@ -161,7 +162,7 @@ func (t *itabTableType) add(m *itab) {
 	mask := t.size - 1
 	h := itabHashFunc(m.inter, m._type) & mask
 	for i := uintptr(1); ; i++ {
-		p := (**itab)(add(unsafe.Pointer(&t.entries), h*sys.PtrSize))
+		p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize))
 		m2 := *p
 		if m2 == m {
 			// A given itab may be used in more than one module
@@ -315,26 +316,36 @@ var (
 // The convXXX functions succeed on a nil input, whereas the assertXXX
 // functions fail on a nil input.
 
-func convT2E(t *_type, elem unsafe.Pointer) (e eface) {
+// convT converts a value of type t, which is pointed to by v, to a pointer that can
+// be used as the second word of an interface value.
+func convT(t *_type, v unsafe.Pointer) unsafe.Pointer {
 	if raceenabled {
-		raceReadObjectPC(t, elem, getcallerpc(), funcPC(convT2E))
+		raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convT))
 	}
 	if msanenabled {
-		msanread(elem, t.size)
+		msanread(v, t.size)
 	}
 	x := mallocgc(t.size, t, true)
-	// TODO: We allocate a zeroed object only to overwrite it with actual data.
-	// Figure out how to avoid zeroing. Also below in convT2Eslice, convT2I, convT2Islice.
-	typedmemmove(t, x, elem)
-	e._type = t
-	e.data = x
-	return
+	typedmemmove(t, x, v)
+	return x
+}
+func convTnoptr(t *_type, v unsafe.Pointer) unsafe.Pointer {
+	// TODO: maybe take size instead of type?
+	if raceenabled {
+		raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convTnoptr))
+	}
+	if msanenabled {
+		msanread(v, t.size)
+	}
+	x := mallocgc(t.size, t, false)
+	memmove(x, v, t.size)
+	return x
 }
 
 func convT16(val uint16) (x unsafe.Pointer) {
 	if val < uint16(len(staticuint64s)) {
 		x = unsafe.Pointer(&staticuint64s[val])
-		if sys.BigEndian {
+		if goarch.BigEndian {
 			x = add(x, 6)
 		}
 	} else {
@@ -347,7 +358,7 @@ func convT16(val uint16) (x unsafe.Pointer) {
 func convT32(val uint32) (x unsafe.Pointer) {
 	if val < uint32(len(staticuint64s)) {
 		x = unsafe.Pointer(&staticuint64s[val])
-		if sys.BigEndian {
+		if goarch.BigEndian {
 			x = add(x, 4)
 		}
 	} else {
@@ -388,63 +399,16 @@ func convTslice(val []byte) (x unsafe.Pointer) {
 	return
 }
 
-func convT2Enoptr(t *_type, elem unsafe.Pointer) (e eface) {
-	if raceenabled {
-		raceReadObjectPC(t, elem, getcallerpc(), funcPC(convT2Enoptr))
+// convI2I returns the new itab to be used for the destination value
+// when converting a value with itab src to the dst interface.
+func convI2I(dst *interfacetype, src *itab) *itab {
+	if src == nil {
+		return nil
 	}
-	if msanenabled {
-		msanread(elem, t.size)
+	if src.inter == dst {
+		return src
 	}
-	x := mallocgc(t.size, t, false)
-	memmove(x, elem, t.size)
-	e._type = t
-	e.data = x
-	return
-}
-
-func convT2I(tab *itab, elem unsafe.Pointer) (i iface) {
-	t := tab._type
-	if raceenabled {
-		raceReadObjectPC(t, elem, getcallerpc(), funcPC(convT2I))
-	}
-	if msanenabled {
-		msanread(elem, t.size)
-	}
-	x := mallocgc(t.size, t, true)
-	typedmemmove(t, x, elem)
-	i.tab = tab
-	i.data = x
-	return
-}
-
-func convT2Inoptr(tab *itab, elem unsafe.Pointer) (i iface) {
-	t := tab._type
-	if raceenabled {
-		raceReadObjectPC(t, elem, getcallerpc(), funcPC(convT2Inoptr))
-	}
-	if msanenabled {
-		msanread(elem, t.size)
-	}
-	x := mallocgc(t.size, t, false)
-	memmove(x, elem, t.size)
-	i.tab = tab
-	i.data = x
-	return
-}
-
-func convI2I(inter *interfacetype, i iface) (r iface) {
-	tab := i.tab
-	if tab == nil {
-		return
-	}
-	if tab.inter == inter {
-		r.tab = tab
-		r.data = i.data
-		return
-	}
-	r.tab = getitab(inter, tab._type, false)
-	r.data = i.data
-	return
+	return getitab(dst, src._type, false)
 }
 
 func assertI2I(inter *interfacetype, tab *itab) *itab {
@@ -511,7 +475,7 @@ func iterate_itabs(fn func(*itab)) {
 	// so no other locks/atomics needed.
 	t := itabTable
 	for i := uintptr(0); i < t.size; i++ {
-		m := *(**itab)(add(unsafe.Pointer(&t.entries), i*sys.PtrSize))
+		m := *(**itab)(add(unsafe.Pointer(&t.entries), i*goarch.PtrSize))
 		if m != nil {
 			fn(m)
 		}
diff --git a/src/runtime/internal/atomic/atomic_386.s b/src/runtime/internal/atomic/atomic_386.s
index 37318e0ad76..724d5152313 100644
--- a/src/runtime/internal/atomic/atomic_386.s
+++ b/src/runtime/internal/atomic/atomic_386.s
@@ -65,7 +65,7 @@ TEXT ·Xaddint64(SB), NOSPLIT, $0-20
 
 // bool ·Cas64(uint64 *val, uint64 old, uint64 new)
 // Atomically:
-//	if(*val == *old){
+//	if(*val == old){
 //		*val = new;
 //		return 1;
 //	} else {
diff --git a/src/runtime/internal/atomic/atomic_amd64.s b/src/runtime/internal/atomic/atomic_amd64.s
index 57cd59dd8cc..d21514b36b9 100644
--- a/src/runtime/internal/atomic/atomic_amd64.s
+++ b/src/runtime/internal/atomic/atomic_amd64.s
@@ -37,7 +37,7 @@ TEXT ·Cas(SB),NOSPLIT,$0-17
 
 // bool	·Cas64(uint64 *val, uint64 old, uint64 new)
 // Atomically:
-//	if(*val == *old){
+//	if(*val == old){
 //		*val = new;
 //		return 1;
 //	} else {
diff --git a/src/runtime/internal/atomic/atomic_arm64.go b/src/runtime/internal/atomic/atomic_arm64.go
index 131c687e1ba..dbb1796ec09 100644
--- a/src/runtime/internal/atomic/atomic_arm64.go
+++ b/src/runtime/internal/atomic/atomic_arm64.go
@@ -7,7 +7,14 @@
 
 package atomic
 
-import "unsafe"
+import (
+	"internal/cpu"
+	"unsafe"
+)
+
+const (
+	offsetARM64HasATOMICS = unsafe.Offsetof(cpu.ARM64.HasATOMICS)
+)
 
 //go:noescape
 func Xadd(ptr *uint32, delta int32) uint32
diff --git a/src/runtime/internal/atomic/atomic_arm64.s b/src/runtime/internal/atomic/atomic_arm64.s
index 587e7f05e25..5f77d92deba 100644
--- a/src/runtime/internal/atomic/atomic_arm64.s
+++ b/src/runtime/internal/atomic/atomic_arm64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+#include "go_asm.h"
 #include "textflag.h"
 
 TEXT ·Casint32(SB), NOSPLIT, $0-17
@@ -127,10 +128,15 @@ TEXT ·Store64(SB), NOSPLIT, $0-16
 TEXT ·Xchg(SB), NOSPLIT, $0-20
 	MOVD	ptr+0(FP), R0
 	MOVW	new+8(FP), R1
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	SWPALW	R1, (R0), R2
+	MOVW	R2, ret+16(FP)
+	RET
+load_store_loop:
 	LDAXRW	(R0), R2
 	STLXRW	R1, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 	MOVW	R2, ret+16(FP)
 	RET
 
@@ -142,10 +148,15 @@ again:
 TEXT ·Xchg64(SB), NOSPLIT, $0-24
 	MOVD	ptr+0(FP), R0
 	MOVD	new+8(FP), R1
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	SWPALD	R1, (R0), R2
+	MOVD	R2, ret+16(FP)
+	RET
+load_store_loop:
 	LDAXR	(R0), R2
 	STLXR	R1, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 	MOVD	R2, ret+16(FP)
 	RET
 
@@ -160,12 +171,20 @@ TEXT ·Cas(SB), NOSPLIT, $0-17
 	MOVD	ptr+0(FP), R0
 	MOVW	old+8(FP), R1
 	MOVW	new+12(FP), R2
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	MOVD	R1, R3
+	CASALW	R3, (R0), R2
+	CMP 	R1, R3
+	CSET	EQ, R0
+	MOVB	R0, ret+16(FP)
+	RET
+load_store_loop:
 	LDAXRW	(R0), R3
 	CMPW	R1, R3
 	BNE	ok
 	STLXRW	R2, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 ok:
 	CSET	EQ, R0
 	MOVB	R0, ret+16(FP)
@@ -173,7 +192,7 @@ ok:
 
 // bool ·Cas64(uint64 *ptr, uint64 old, uint64 new)
 // Atomically:
-//      if(*val == *old){
+//      if(*val == old){
 //              *val = new;
 //              return 1;
 //      } else {
@@ -183,12 +202,20 @@ TEXT ·Cas64(SB), NOSPLIT, $0-25
 	MOVD	ptr+0(FP), R0
 	MOVD	old+8(FP), R1
 	MOVD	new+16(FP), R2
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	MOVD	R1, R3
+	CASALD	R3, (R0), R2
+	CMP 	R1, R3
+	CSET	EQ, R0
+	MOVB	R0, ret+24(FP)
+	RET
+load_store_loop:
 	LDAXR	(R0), R3
 	CMP	R1, R3
 	BNE	ok
 	STLXR	R2, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 ok:
 	CSET	EQ, R0
 	MOVB	R0, ret+24(FP)
@@ -201,11 +228,17 @@ ok:
 TEXT ·Xadd(SB), NOSPLIT, $0-20
 	MOVD	ptr+0(FP), R0
 	MOVW	delta+8(FP), R1
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	LDADDALW	R1, (R0), R2
+	ADD 	R1, R2
+	MOVW	R2, ret+16(FP)
+	RET
+load_store_loop:
 	LDAXRW	(R0), R2
 	ADDW	R2, R1, R2
 	STLXRW	R2, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 	MOVW	R2, ret+16(FP)
 	RET
 
@@ -216,11 +249,17 @@ again:
 TEXT ·Xadd64(SB), NOSPLIT, $0-24
 	MOVD	ptr+0(FP), R0
 	MOVD	delta+8(FP), R1
-again:
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	LDADDALD	R1, (R0), R2
+	ADD 	R1, R2
+	MOVD	R2, ret+16(FP)
+	RET
+load_store_loop:
 	LDAXR	(R0), R2
 	ADD	R2, R1, R2
 	STLXR	R2, (R0), R3
-	CBNZ	R3, again
+	CBNZ	R3, load_store_loop
 	MOVD	R2, ret+16(FP)
 	RET
 
@@ -236,37 +275,59 @@ TEXT ·Xchguintptr(SB), NOSPLIT, $0-24
 TEXT ·And8(SB), NOSPLIT, $0-9
 	MOVD	ptr+0(FP), R0
 	MOVB	val+8(FP), R1
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	MVN 	R1, R2
+	LDCLRALB	R2, (R0), R3
+	RET
+load_store_loop:
 	LDAXRB	(R0), R2
 	AND	R1, R2
 	STLXRB	R2, (R0), R3
-	CBNZ	R3, -3(PC)
+	CBNZ	R3, load_store_loop
 	RET
 
 TEXT ·Or8(SB), NOSPLIT, $0-9
 	MOVD	ptr+0(FP), R0
 	MOVB	val+8(FP), R1
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	LDORALB	R1, (R0), R2
+	RET
+load_store_loop:
 	LDAXRB	(R0), R2
 	ORR	R1, R2
 	STLXRB	R2, (R0), R3
-	CBNZ	R3, -3(PC)
+	CBNZ	R3, load_store_loop
 	RET
 
 // func And(addr *uint32, v uint32)
 TEXT ·And(SB), NOSPLIT, $0-12
 	MOVD	ptr+0(FP), R0
 	MOVW	val+8(FP), R1
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	MVN 	R1, R2
+	LDCLRALW	R2, (R0), R3
+	RET
+load_store_loop:
 	LDAXRW	(R0), R2
 	AND	R1, R2
 	STLXRW	R2, (R0), R3
-	CBNZ	R3, -3(PC)
+	CBNZ	R3, load_store_loop
 	RET
 
 // func Or(addr *uint32, v uint32)
 TEXT ·Or(SB), NOSPLIT, $0-12
 	MOVD	ptr+0(FP), R0
 	MOVW	val+8(FP), R1
+	MOVBU	internal∕cpu·ARM64+const_offsetARM64HasATOMICS(SB), R4
+	CBZ 	R4, load_store_loop
+	LDORALW	R1, (R0), R2
+	RET
+load_store_loop:
 	LDAXRW	(R0), R2
 	ORR	R1, R2
 	STLXRW	R2, (R0), R3
-	CBNZ	R3, -3(PC)
+	CBNZ	R3, load_store_loop
 	RET
diff --git a/src/runtime/internal/atomic/atomic_mips64x.s b/src/runtime/internal/atomic/atomic_mips64x.s
index 2751c6f8082..fedfc4a175c 100644
--- a/src/runtime/internal/atomic/atomic_mips64x.s
+++ b/src/runtime/internal/atomic/atomic_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
@@ -36,7 +37,7 @@ cas_fail:
 
 // bool	cas64(uint64 *ptr, uint64 old, uint64 new)
 // Atomically:
-//	if(*val == *old){
+//	if(*val == old){
 //		*val = new;
 //		return 1;
 //	} else {
diff --git a/src/runtime/internal/atomic/atomic_mipsx.s b/src/runtime/internal/atomic/atomic_mipsx.s
index 3f613214507..c0835d66ed8 100644
--- a/src/runtime/internal/atomic/atomic_mipsx.s
+++ b/src/runtime/internal/atomic/atomic_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/runtime/internal/atomic/atomic_ppc64x.s b/src/runtime/internal/atomic/atomic_ppc64x.s
index 37c8515d37e..226b3b62162 100644
--- a/src/runtime/internal/atomic/atomic_ppc64x.s
+++ b/src/runtime/internal/atomic/atomic_ppc64x.s
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
 
-
 // For more details about how various memory models are
 // enforced on POWER, the following paper provides more
 // details about how they enforce C/C++ like models. This
@@ -107,7 +107,7 @@ cas_fail:
 
 // bool	·Cas64(uint64 *ptr, uint64 old, uint64 new)
 // Atomically:
-//	if(*val == *old){
+//	if(*val == old){
 //		*val = new;
 //		return 1;
 //	} else {
diff --git a/src/runtime/internal/atomic/atomic_riscv64.s b/src/runtime/internal/atomic/atomic_riscv64.s
index ec05302a784..21d5adcdbc5 100644
--- a/src/runtime/internal/atomic/atomic_riscv64.s
+++ b/src/runtime/internal/atomic/atomic_riscv64.s
@@ -30,8 +30,9 @@
 
 #include "textflag.h"
 
+// func Cas(ptr *uint64, old, new uint64) bool
 // Atomically:
-//      if(*val == *old){
+//      if(*val == old){
 //              *val = new;
 //              return 1;
 //      } else {
diff --git a/src/runtime/internal/atomic/atomic_test.go b/src/runtime/internal/atomic/atomic_test.go
index c9c2eba248c..2ae60b8507e 100644
--- a/src/runtime/internal/atomic/atomic_test.go
+++ b/src/runtime/internal/atomic/atomic_test.go
@@ -5,9 +5,9 @@
 package atomic_test
 
 import (
+	"internal/goarch"
 	"runtime"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"testing"
 	"unsafe"
 )
@@ -56,7 +56,7 @@ func TestXadduintptr(t *testing.T) {
 // Tests that xadduintptr correctly updates 64-bit values. The place where
 // we actually do so is mstats.go, functions mSysStat{Inc,Dec}.
 func TestXadduintptrOnUint64(t *testing.T) {
-	if sys.BigEndian {
+	if goarch.BigEndian {
 		// On big endian architectures, we never use xadduintptr to update
 		// 64-bit values and hence we skip the test.  (Note that functions
 		// mSysStat{Inc,Dec} in mstats.go have explicit checks for
diff --git a/src/runtime/internal/atomic/sys_nonlinux_arm.s b/src/runtime/internal/atomic/sys_nonlinux_arm.s
index 57568b2238d..04036ca9702 100644
--- a/src/runtime/internal/atomic/sys_nonlinux_arm.s
+++ b/src/runtime/internal/atomic/sys_nonlinux_arm.s
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !linux,arm
+//go:build !linux
+// +build !linux
 
 #include "textflag.h"
 
diff --git a/src/runtime/internal/math/math.go b/src/runtime/internal/math/math.go
index b6bd12d3e8b..c3fac366be0 100644
--- a/src/runtime/internal/math/math.go
+++ b/src/runtime/internal/math/math.go
@@ -4,14 +4,14 @@
 
 package math
 
-import "runtime/internal/sys"
+import "internal/goarch"
 
 const MaxUintptr = ^uintptr(0)
 
 // MulUintptr returns a * b and whether the multiplication overflowed.
 // On supported platforms this is an intrinsic lowered by the compiler.
 func MulUintptr(a, b uintptr) (uintptr, bool) {
-	if a|b < 1<<(4*sys.PtrSize) || a == 0 {
+	if a|b < 1<<(4*goarch.PtrSize) || a == 0 {
 		return a * b, false
 	}
 	overflow := b > MaxUintptr/a
diff --git a/src/runtime/internal/sys/consts.go b/src/runtime/internal/sys/consts.go
new file mode 100644
index 00000000000..fffcf81d1f3
--- /dev/null
+++ b/src/runtime/internal/sys/consts.go
@@ -0,0 +1,34 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sys
+
+import (
+	"internal/goarch"
+	"internal/goos"
+)
+
+// AIX requires a larger stack for syscalls.
+const StackGuardMultiplier = StackGuardMultiplierDefault*(1-goos.IsAix) + 2*goos.IsAix
+
+// DefaultPhysPageSize is the default physical page size.
+const DefaultPhysPageSize = goarch.DefaultPhysPageSize
+
+// PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).
+// The various PC tables record PC deltas pre-divided by PCQuantum.
+const PCQuantum = goarch.PCQuantum
+
+// Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).
+const Int64Align = goarch.PtrSize
+
+// MinFrameSize is the size of the system-reserved words at the bottom
+// of a frame (just above the architectural stack pointer).
+// It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
+// On PowerPC it is larger, to cover three more reserved words:
+// the compiler word, the link editor word, and the TOC save word.
+const MinFrameSize = goarch.MinFrameSize
+
+// StackAlign is the required alignment of the SP register.
+// The stack must be at least word aligned, but some architectures require more.
+const StackAlign = goarch.StackAlign
diff --git a/src/runtime/internal/sys/gengoos.go b/src/runtime/internal/sys/gengoos.go
deleted file mode 100644
index 51f64a6e5c6..00000000000
--- a/src/runtime/internal/sys/gengoos.go
+++ /dev/null
@@ -1,99 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build ignore
-// +build ignore
-
-package main
-
-import (
-	"bytes"
-	"fmt"
-	"log"
-	"os"
-	"strconv"
-	"strings"
-)
-
-var gooses, goarches []string
-
-func main() {
-	data, err := os.ReadFile("../../../go/build/syslist.go")
-	if err != nil {
-		log.Fatal(err)
-	}
-	const (
-		goosPrefix   = `const goosList = `
-		goarchPrefix = `const goarchList = `
-	)
-	for _, line := range strings.Split(string(data), "\n") {
-		if strings.HasPrefix(line, goosPrefix) {
-			text, err := strconv.Unquote(strings.TrimPrefix(line, goosPrefix))
-			if err != nil {
-				log.Fatalf("parsing goosList: %v", err)
-			}
-			gooses = strings.Fields(text)
-		}
-		if strings.HasPrefix(line, goarchPrefix) {
-			text, err := strconv.Unquote(strings.TrimPrefix(line, goarchPrefix))
-			if err != nil {
-				log.Fatalf("parsing goarchList: %v", err)
-			}
-			goarches = strings.Fields(text)
-		}
-	}
-
-	for _, target := range gooses {
-		if target == "nacl" {
-			continue
-		}
-		var buf bytes.Buffer
-		fmt.Fprintf(&buf, "// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.\n\n")
-		if target == "linux" {
-			fmt.Fprintf(&buf, "// +build !android\n") // must explicitly exclude android for linux
-		}
-		if target == "solaris" {
-			fmt.Fprintf(&buf, "// +build !illumos\n") // must explicitly exclude illumos for solaris
-		}
-		if target == "darwin" {
-			fmt.Fprintf(&buf, "// +build !ios\n") // must explicitly exclude ios for darwin
-		}
-		fmt.Fprintf(&buf, "// +build %s\n\n", target) // must explicitly include target for bootstrapping purposes
-		fmt.Fprintf(&buf, "package sys\n\n")
-		fmt.Fprintf(&buf, "const GOOS = `%s`\n\n", target)
-		for _, goos := range gooses {
-			value := 0
-			if goos == target {
-				value = 1
-			}
-			fmt.Fprintf(&buf, "const Goos%s = %d\n", strings.Title(goos), value)
-		}
-		err := os.WriteFile("zgoos_"+target+".go", buf.Bytes(), 0666)
-		if err != nil {
-			log.Fatal(err)
-		}
-	}
-
-	for _, target := range goarches {
-		if target == "amd64p32" {
-			continue
-		}
-		var buf bytes.Buffer
-		fmt.Fprintf(&buf, "// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.\n\n")
-		fmt.Fprintf(&buf, "// +build %s\n\n", target) // must explicitly include target for bootstrapping purposes
-		fmt.Fprintf(&buf, "package sys\n\n")
-		fmt.Fprintf(&buf, "const GOARCH = `%s`\n\n", target)
-		for _, goarch := range goarches {
-			value := 0
-			if goarch == target {
-				value = 1
-			}
-			fmt.Fprintf(&buf, "const Goarch%s = %d\n", strings.Title(goarch), value)
-		}
-		err := os.WriteFile("zgoarch_"+target+".go", buf.Bytes(), 0666)
-		if err != nil {
-			log.Fatal(err)
-		}
-	}
-}
diff --git a/src/runtime/internal/sys/sys.go b/src/runtime/internal/sys/sys.go
index 9d9ac4507f6..694101d36fd 100644
--- a/src/runtime/internal/sys/sys.go
+++ b/src/runtime/internal/sys/sys.go
@@ -5,11 +5,3 @@
 // package sys contains system- and configuration- and architecture-specific
 // constants used by the runtime.
 package sys
-
-// The next line makes 'go generate' write the zgo*.go files with
-// per-OS and per-arch information, including constants
-// named Goos$GOOS and Goarch$GOARCH for every
-// known GOOS and GOARCH. The constant is 1 on the
-// current system, 0 otherwise; multiplying by them is
-// useful for defining GOOS- or GOARCH-specific constants.
-//go:generate go run gengoos.go
diff --git a/src/runtime/internal/sys/zgoarch_386.go b/src/runtime/internal/sys/zgoarch_386.go
deleted file mode 100644
index 98a2401bfe9..00000000000
--- a/src/runtime/internal/sys/zgoarch_386.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build 386
-// +build 386
-
-package sys
-
-const GOARCH = `386`
-
-const Goarch386 = 1
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_amd64.go b/src/runtime/internal/sys/zgoarch_amd64.go
deleted file mode 100644
index d8faa5c7860..00000000000
--- a/src/runtime/internal/sys/zgoarch_amd64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build amd64
-// +build amd64
-
-package sys
-
-const GOARCH = `amd64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 1
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_arm.go b/src/runtime/internal/sys/zgoarch_arm.go
deleted file mode 100644
index b64a69c9b44..00000000000
--- a/src/runtime/internal/sys/zgoarch_arm.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build arm
-// +build arm
-
-package sys
-
-const GOARCH = `arm`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 1
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_arm64.go b/src/runtime/internal/sys/zgoarch_arm64.go
deleted file mode 100644
index de6f85347b1..00000000000
--- a/src/runtime/internal/sys/zgoarch_arm64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build arm64
-// +build arm64
-
-package sys
-
-const GOARCH = `arm64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 1
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_arm64be.go b/src/runtime/internal/sys/zgoarch_arm64be.go
deleted file mode 100644
index b762bb069f8..00000000000
--- a/src/runtime/internal/sys/zgoarch_arm64be.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build arm64be
-// +build arm64be
-
-package sys
-
-const GOARCH = `arm64be`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 1
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_armbe.go b/src/runtime/internal/sys/zgoarch_armbe.go
deleted file mode 100644
index e5297e4b169..00000000000
--- a/src/runtime/internal/sys/zgoarch_armbe.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build armbe
-// +build armbe
-
-package sys
-
-const GOARCH = `armbe`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 1
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mips.go b/src/runtime/internal/sys/zgoarch_mips.go
deleted file mode 100644
index b5f4ed390c6..00000000000
--- a/src/runtime/internal/sys/zgoarch_mips.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mips
-// +build mips
-
-package sys
-
-const GOARCH = `mips`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 1
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mips64.go b/src/runtime/internal/sys/zgoarch_mips64.go
deleted file mode 100644
index 73777cceb21..00000000000
--- a/src/runtime/internal/sys/zgoarch_mips64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mips64
-// +build mips64
-
-package sys
-
-const GOARCH = `mips64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 1
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mips64le.go b/src/runtime/internal/sys/zgoarch_mips64le.go
deleted file mode 100644
index 0c81c36c097..00000000000
--- a/src/runtime/internal/sys/zgoarch_mips64le.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mips64le
-// +build mips64le
-
-package sys
-
-const GOARCH = `mips64le`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 1
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mips64p32.go b/src/runtime/internal/sys/zgoarch_mips64p32.go
deleted file mode 100644
index d63ce27d24d..00000000000
--- a/src/runtime/internal/sys/zgoarch_mips64p32.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mips64p32
-// +build mips64p32
-
-package sys
-
-const GOARCH = `mips64p32`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 1
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mips64p32le.go b/src/runtime/internal/sys/zgoarch_mips64p32le.go
deleted file mode 100644
index 2d577890b2e..00000000000
--- a/src/runtime/internal/sys/zgoarch_mips64p32le.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mips64p32le
-// +build mips64p32le
-
-package sys
-
-const GOARCH = `mips64p32le`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 1
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_mipsle.go b/src/runtime/internal/sys/zgoarch_mipsle.go
deleted file mode 100644
index 8af919d03a3..00000000000
--- a/src/runtime/internal/sys/zgoarch_mipsle.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build mipsle
-// +build mipsle
-
-package sys
-
-const GOARCH = `mipsle`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 1
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_ppc.go b/src/runtime/internal/sys/zgoarch_ppc.go
deleted file mode 100644
index f6f12a5ddce..00000000000
--- a/src/runtime/internal/sys/zgoarch_ppc.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build ppc
-// +build ppc
-
-package sys
-
-const GOARCH = `ppc`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 1
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_ppc64.go b/src/runtime/internal/sys/zgoarch_ppc64.go
deleted file mode 100644
index a8379601f47..00000000000
--- a/src/runtime/internal/sys/zgoarch_ppc64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build ppc64
-// +build ppc64
-
-package sys
-
-const GOARCH = `ppc64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 1
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_ppc64le.go b/src/runtime/internal/sys/zgoarch_ppc64le.go
deleted file mode 100644
index f2ec5dcba72..00000000000
--- a/src/runtime/internal/sys/zgoarch_ppc64le.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build ppc64le
-// +build ppc64le
-
-package sys
-
-const GOARCH = `ppc64le`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 1
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_riscv.go b/src/runtime/internal/sys/zgoarch_riscv.go
deleted file mode 100644
index 83a3312f5f3..00000000000
--- a/src/runtime/internal/sys/zgoarch_riscv.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build riscv
-// +build riscv
-
-package sys
-
-const GOARCH = `riscv`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 1
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_riscv64.go b/src/runtime/internal/sys/zgoarch_riscv64.go
deleted file mode 100644
index 1dfcc84997b..00000000000
--- a/src/runtime/internal/sys/zgoarch_riscv64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build riscv64
-// +build riscv64
-
-package sys
-
-const GOARCH = `riscv64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 1
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_s390.go b/src/runtime/internal/sys/zgoarch_s390.go
deleted file mode 100644
index 91aba5a0f6c..00000000000
--- a/src/runtime/internal/sys/zgoarch_s390.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build s390
-// +build s390
-
-package sys
-
-const GOARCH = `s390`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 1
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_s390x.go b/src/runtime/internal/sys/zgoarch_s390x.go
deleted file mode 100644
index edce50234e5..00000000000
--- a/src/runtime/internal/sys/zgoarch_s390x.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build s390x
-// +build s390x
-
-package sys
-
-const GOARCH = `s390x`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 1
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_sparc.go b/src/runtime/internal/sys/zgoarch_sparc.go
deleted file mode 100644
index 5ae9560ab01..00000000000
--- a/src/runtime/internal/sys/zgoarch_sparc.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build sparc
-// +build sparc
-
-package sys
-
-const GOARCH = `sparc`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 1
-const GoarchSparc64 = 0
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_sparc64.go b/src/runtime/internal/sys/zgoarch_sparc64.go
deleted file mode 100644
index e2a0134affd..00000000000
--- a/src/runtime/internal/sys/zgoarch_sparc64.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build sparc64
-// +build sparc64
-
-package sys
-
-const GOARCH = `sparc64`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 1
-const GoarchWasm = 0
diff --git a/src/runtime/internal/sys/zgoarch_wasm.go b/src/runtime/internal/sys/zgoarch_wasm.go
deleted file mode 100644
index 52e85dea371..00000000000
--- a/src/runtime/internal/sys/zgoarch_wasm.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build wasm
-// +build wasm
-
-package sys
-
-const GOARCH = `wasm`
-
-const Goarch386 = 0
-const GoarchAmd64 = 0
-const GoarchAmd64p32 = 0
-const GoarchArm = 0
-const GoarchArmbe = 0
-const GoarchArm64 = 0
-const GoarchArm64be = 0
-const GoarchPpc64 = 0
-const GoarchPpc64le = 0
-const GoarchMips = 0
-const GoarchMipsle = 0
-const GoarchMips64 = 0
-const GoarchMips64le = 0
-const GoarchMips64p32 = 0
-const GoarchMips64p32le = 0
-const GoarchPpc = 0
-const GoarchRiscv = 0
-const GoarchRiscv64 = 0
-const GoarchS390 = 0
-const GoarchS390x = 0
-const GoarchSparc = 0
-const GoarchSparc64 = 0
-const GoarchWasm = 1
diff --git a/src/runtime/internal/sys/zgoos_aix.go b/src/runtime/internal/sys/zgoos_aix.go
deleted file mode 100644
index f3b907471f6..00000000000
--- a/src/runtime/internal/sys/zgoos_aix.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build aix
-// +build aix
-
-package sys
-
-const GOOS = `aix`
-
-const GoosAix = 1
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_android.go b/src/runtime/internal/sys/zgoos_android.go
deleted file mode 100644
index e28baf7c481..00000000000
--- a/src/runtime/internal/sys/zgoos_android.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build android
-// +build android
-
-package sys
-
-const GOOS = `android`
-
-const GoosAix = 0
-const GoosAndroid = 1
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_darwin.go b/src/runtime/internal/sys/zgoos_darwin.go
deleted file mode 100644
index 3c7f7b543ee..00000000000
--- a/src/runtime/internal/sys/zgoos_darwin.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build !ios && darwin
-// +build !ios,darwin
-
-package sys
-
-const GOOS = `darwin`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 1
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_dragonfly.go b/src/runtime/internal/sys/zgoos_dragonfly.go
deleted file mode 100644
index f844d29e2a1..00000000000
--- a/src/runtime/internal/sys/zgoos_dragonfly.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build dragonfly
-// +build dragonfly
-
-package sys
-
-const GOOS = `dragonfly`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 1
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_freebsd.go b/src/runtime/internal/sys/zgoos_freebsd.go
deleted file mode 100644
index 8999a2797af..00000000000
--- a/src/runtime/internal/sys/zgoos_freebsd.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build freebsd
-// +build freebsd
-
-package sys
-
-const GOOS = `freebsd`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 1
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_hurd.go b/src/runtime/internal/sys/zgoos_hurd.go
deleted file mode 100644
index a546488bf89..00000000000
--- a/src/runtime/internal/sys/zgoos_hurd.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build hurd
-// +build hurd
-
-package sys
-
-const GOOS = `hurd`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 1
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_illumos.go b/src/runtime/internal/sys/zgoos_illumos.go
deleted file mode 100644
index 02a4ca06e82..00000000000
--- a/src/runtime/internal/sys/zgoos_illumos.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build illumos
-// +build illumos
-
-package sys
-
-const GOOS = `illumos`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 1
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_ios.go b/src/runtime/internal/sys/zgoos_ios.go
deleted file mode 100644
index 033eec623df..00000000000
--- a/src/runtime/internal/sys/zgoos_ios.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build ios
-// +build ios
-
-package sys
-
-const GOOS = `ios`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 1
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_js.go b/src/runtime/internal/sys/zgoos_js.go
deleted file mode 100644
index 28226ad60ad..00000000000
--- a/src/runtime/internal/sys/zgoos_js.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build js
-// +build js
-
-package sys
-
-const GOOS = `js`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 1
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_linux.go b/src/runtime/internal/sys/zgoos_linux.go
deleted file mode 100644
index 01546e4b9f2..00000000000
--- a/src/runtime/internal/sys/zgoos_linux.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build !android && linux
-// +build !android,linux
-
-package sys
-
-const GOOS = `linux`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 1
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_netbsd.go b/src/runtime/internal/sys/zgoos_netbsd.go
deleted file mode 100644
index 9d658b20ee2..00000000000
--- a/src/runtime/internal/sys/zgoos_netbsd.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build netbsd
-// +build netbsd
-
-package sys
-
-const GOOS = `netbsd`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 1
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_openbsd.go b/src/runtime/internal/sys/zgoos_openbsd.go
deleted file mode 100644
index 0f55454a953..00000000000
--- a/src/runtime/internal/sys/zgoos_openbsd.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build openbsd
-// +build openbsd
-
-package sys
-
-const GOOS = `openbsd`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 1
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_plan9.go b/src/runtime/internal/sys/zgoos_plan9.go
deleted file mode 100644
index d0347464d6d..00000000000
--- a/src/runtime/internal/sys/zgoos_plan9.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build plan9
-// +build plan9
-
-package sys
-
-const GOOS = `plan9`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 1
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_solaris.go b/src/runtime/internal/sys/zgoos_solaris.go
deleted file mode 100644
index 05c3007e2c2..00000000000
--- a/src/runtime/internal/sys/zgoos_solaris.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build !illumos && solaris
-// +build !illumos,solaris
-
-package sys
-
-const GOOS = `solaris`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 1
-const GoosWindows = 0
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_windows.go b/src/runtime/internal/sys/zgoos_windows.go
deleted file mode 100644
index 7d07fa3a451..00000000000
--- a/src/runtime/internal/sys/zgoos_windows.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build windows
-// +build windows
-
-package sys
-
-const GOOS = `windows`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 1
-const GoosZos = 0
diff --git a/src/runtime/internal/sys/zgoos_zos.go b/src/runtime/internal/sys/zgoos_zos.go
deleted file mode 100644
index d6e5b9b0cb2..00000000000
--- a/src/runtime/internal/sys/zgoos_zos.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
-
-//go:build zos
-// +build zos
-
-package sys
-
-const GOOS = `zos`
-
-const GoosAix = 0
-const GoosAndroid = 0
-const GoosDarwin = 0
-const GoosDragonfly = 0
-const GoosFreebsd = 0
-const GoosHurd = 0
-const GoosIllumos = 0
-const GoosIos = 0
-const GoosJs = 0
-const GoosLinux = 0
-const GoosNacl = 0
-const GoosNetbsd = 0
-const GoosOpenbsd = 0
-const GoosPlan9 = 0
-const GoosSolaris = 0
-const GoosWindows = 0
-const GoosZos = 1
diff --git a/src/runtime/libfuzzer_amd64.s b/src/runtime/libfuzzer_amd64.s
index 890fde341bc..13645fc7af8 100644
--- a/src/runtime/libfuzzer_amd64.s
+++ b/src/runtime/libfuzzer_amd64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build libfuzzer
 // +build libfuzzer
 
 #include "go_asm.h"
diff --git a/src/runtime/libfuzzer_arm64.s b/src/runtime/libfuzzer_arm64.s
index 121673e0922..4ad8242804e 100644
--- a/src/runtime/libfuzzer_arm64.s
+++ b/src/runtime/libfuzzer_arm64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build libfuzzer
 // +build libfuzzer
 
 #include "go_asm.h"
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 81e52258830..f8d5d48a28d 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -101,6 +101,8 @@
 package runtime
 
 import (
+	"internal/goarch"
+	"internal/goos"
 	"runtime/internal/atomic"
 	"runtime/internal/math"
 	"runtime/internal/sys"
@@ -150,7 +152,7 @@ const (
 	//   windows/32       | 4KB        | 3
 	//   windows/64       | 8KB        | 2
 	//   plan9            | 4KB        | 3
-	_NumStackOrders = 4 - sys.PtrSize/4*sys.GoosWindows - 1*sys.GoosPlan9
+	_NumStackOrders = 4 - goarch.PtrSize/4*goos.IsWindows - 1*goos.IsPlan9
 
 	// heapAddrBits is the number of bits in a heap address. On
 	// amd64, addresses are sign-extended beyond heapAddrBits. On
@@ -207,7 +209,7 @@ const (
 	// arenaBaseOffset to offset into the top 4 GiB.
 	//
 	// WebAssembly currently has a limit of 4GB linear memory.
-	heapAddrBits = (_64bit*(1-sys.GoarchWasm)*(1-sys.GoosIos*sys.GoarchArm64))*48 + (1-_64bit+sys.GoarchWasm)*(32-(sys.GoarchMips+sys.GoarchMipsle)) + 33*sys.GoosIos*sys.GoarchArm64
+	heapAddrBits = (_64bit*(1-goarch.IsWasm)*(1-goos.IsIos*goarch.IsArm64))*48 + (1-_64bit+goarch.IsWasm)*(32-(goarch.IsMips+goarch.IsMipsle)) + 33*goos.IsIos*goarch.IsArm64
 
 	// maxAlloc is the maximum size of an allocation. On 64-bit,
 	// it's theoretically possible to allocate 1< typ.size {
 			// Array allocation. If there are any
@@ -1135,13 +1126,21 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 		msanmalloc(x, size)
 	}
 
+	if rate := MemProfileRate; rate > 0 {
+		// Note cache c only valid while m acquired; see #47302
+		if rate != 1 && size < c.nextSample {
+			c.nextSample -= size
+		} else {
+			profilealloc(mp, x, size)
+		}
+	}
 	mp.mallocing = 0
 	releasem(mp)
 
 	// Pointerfree data can be zeroed late in a context where preemption can occur.
 	// x will keep the memory alive.
 	if !isZeroed && needzero {
-		memclrNoHeapPointersChunked(size, x)
+		memclrNoHeapPointersChunked(size, x) // This is a possible preemption point: see #47302
 	}
 
 	if debug.malloc {
@@ -1155,16 +1154,6 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 		}
 	}
 
-	if rate := MemProfileRate; rate > 0 {
-		if rate != 1 && size < c.nextSample {
-			c.nextSample -= size
-		} else {
-			mp := acquirem()
-			profilealloc(mp, x, size)
-			releasem(mp)
-		}
-	}
-
 	if assistG != nil {
 		// Account for internal fragmentation in the assist
 		// debt now that we know it.
@@ -1421,7 +1410,7 @@ func persistentalloc1(size, align uintptr, sysStat *sysMemStat) *notInHeap {
 				break
 			}
 		}
-		persistent.off = alignUp(sys.PtrSize, align)
+		persistent.off = alignUp(goarch.PtrSize, align)
 	}
 	p := persistent.base.add(persistent.off)
 	persistent.off += size
diff --git a/src/runtime/map.go b/src/runtime/map.go
index 111db56b01a..0cad1a354de 100644
--- a/src/runtime/map.go
+++ b/src/runtime/map.go
@@ -54,9 +54,10 @@ package runtime
 // before the table grows. Typical tables will be somewhat less loaded.
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/math"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -103,7 +104,7 @@ const (
 	sameSizeGrow = 8 // the current map growth is to a new map of the same size
 
 	// sentinel bucket ID for iterator checks
-	noCheck = 1<<(8*sys.PtrSize) - 1
+	noCheck = 1<<(8*goarch.PtrSize) - 1
 )
 
 // isEmpty reports whether the given tophash array entry represents an empty bucket entry.
@@ -182,7 +183,7 @@ type hiter struct {
 // bucketShift returns 1<> (sys.PtrSize*8 - 8))
+	top := uint8(hash >> (goarch.PtrSize*8 - 8))
 	if top < minTopHash {
 		top += minTopHash
 	}
@@ -205,11 +206,11 @@ func evacuated(b *bmap) bool {
 }
 
 func (b *bmap) overflow(t *maptype) *bmap {
-	return *(**bmap)(add(unsafe.Pointer(b), uintptr(t.bucketsize)-sys.PtrSize))
+	return *(**bmap)(add(unsafe.Pointer(b), uintptr(t.bucketsize)-goarch.PtrSize))
 }
 
 func (b *bmap) setoverflow(t *maptype, ovf *bmap) {
-	*(**bmap)(add(unsafe.Pointer(b), uintptr(t.bucketsize)-sys.PtrSize)) = ovf
+	*(**bmap)(add(unsafe.Pointer(b), uintptr(t.bucketsize)-goarch.PtrSize)) = ovf
 }
 
 func (b *bmap) keys() unsafe.Pointer {
@@ -394,7 +395,7 @@ func makeBucketArray(t *maptype, b uint8, dirtyalloc unsafe.Pointer) (buckets un
 func mapaccess1(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		pc := funcPC(mapaccess1)
+		pc := abi.FuncPCABIInternal(mapaccess1)
 		racereadpc(unsafe.Pointer(h), callerpc, pc)
 		raceReadObjectPC(t.key, key, callerpc, pc)
 	}
@@ -452,7 +453,7 @@ bucketloop:
 func mapaccess2(t *maptype, h *hmap, key unsafe.Pointer) (unsafe.Pointer, bool) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		pc := funcPC(mapaccess2)
+		pc := abi.FuncPCABIInternal(mapaccess2)
 		racereadpc(unsafe.Pointer(h), callerpc, pc)
 		raceReadObjectPC(t.key, key, callerpc, pc)
 	}
@@ -574,7 +575,7 @@ func mapassign(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		pc := funcPC(mapassign)
+		pc := abi.FuncPCABIInternal(mapassign)
 		racewritepc(unsafe.Pointer(h), callerpc, pc)
 		raceReadObjectPC(t.key, key, callerpc, pc)
 	}
@@ -685,7 +686,7 @@ done:
 func mapdelete(t *maptype, h *hmap, key unsafe.Pointer) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		pc := funcPC(mapdelete)
+		pc := abi.FuncPCABIInternal(mapdelete)
 		racewritepc(unsafe.Pointer(h), callerpc, pc)
 		raceReadObjectPC(t.key, key, callerpc, pc)
 	}
@@ -802,14 +803,14 @@ search:
 func mapiterinit(t *maptype, h *hmap, it *hiter) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapiterinit))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapiterinit))
 	}
 
 	if h == nil || h.count == 0 {
 		return
 	}
 
-	if unsafe.Sizeof(hiter{})/sys.PtrSize != 12 {
+	if unsafe.Sizeof(hiter{})/goarch.PtrSize != 12 {
 		throw("hash_iter size incorrect") // see cmd/compile/internal/reflectdata/reflect.go
 	}
 	it.t = t
@@ -852,7 +853,7 @@ func mapiternext(it *hiter) {
 	h := it.h
 	if raceenabled {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapiternext))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapiternext))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map iteration and map write")
@@ -978,7 +979,7 @@ next:
 func mapclear(t *maptype, h *hmap) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		pc := funcPC(mapclear)
+		pc := abi.FuncPCABIInternal(mapclear)
 		racewritepc(unsafe.Pointer(h), callerpc, pc)
 	}
 
@@ -1280,11 +1281,11 @@ func reflect_makemap(t *maptype, cap int) *hmap {
 	if t.key.equal == nil {
 		throw("runtime.reflect_makemap: unsupported map key type")
 	}
-	if t.key.size > maxKeySize && (!t.indirectkey() || t.keysize != uint8(sys.PtrSize)) ||
+	if t.key.size > maxKeySize && (!t.indirectkey() || t.keysize != uint8(goarch.PtrSize)) ||
 		t.key.size <= maxKeySize && (t.indirectkey() || t.keysize != uint8(t.key.size)) {
 		throw("key size wrong")
 	}
-	if t.elem.size > maxElemSize && (!t.indirectelem() || t.elemsize != uint8(sys.PtrSize)) ||
+	if t.elem.size > maxElemSize && (!t.indirectelem() || t.elemsize != uint8(goarch.PtrSize)) ||
 		t.elem.size <= maxElemSize && (t.indirectelem() || t.elemsize != uint8(t.elem.size)) {
 		throw("elem size wrong")
 	}
@@ -1363,7 +1364,7 @@ func reflect_maplen(h *hmap) int {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(reflect_maplen))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(reflect_maplen))
 	}
 	return h.count
 }
@@ -1375,7 +1376,7 @@ func reflectlite_maplen(h *hmap) int {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(reflect_maplen))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(reflect_maplen))
 	}
 	return h.count
 }
diff --git a/src/runtime/map_fast32.go b/src/runtime/map_fast32.go
index 8d52dad217a..e80caeef552 100644
--- a/src/runtime/map_fast32.go
+++ b/src/runtime/map_fast32.go
@@ -5,14 +5,15 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
 func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast32))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess1_fast32))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0])
@@ -52,7 +53,7 @@ func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
 func mapaccess2_fast32(t *maptype, h *hmap, key uint32) (unsafe.Pointer, bool) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast32))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess2_fast32))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0]), false
@@ -95,7 +96,7 @@ func mapassign_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast32))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapassign_fast32))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map writes")
@@ -185,7 +186,7 @@ func mapassign_fast32ptr(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast32))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapassign_fast32))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map writes")
@@ -272,7 +273,7 @@ done:
 func mapdelete_fast32(t *maptype, h *hmap, key uint32) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapdelete_fast32))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapdelete_fast32))
 	}
 	if h == nil || h.count == 0 {
 		return
@@ -301,7 +302,7 @@ search:
 			// Only clear key if there are pointers in it.
 			// This can only happen if pointers are 32 bit
 			// wide as 64 bit pointers do not fit into a 32 bit key.
-			if sys.PtrSize == 4 && t.key.ptrdata != 0 {
+			if goarch.PtrSize == 4 && t.key.ptrdata != 0 {
 				// The key must be a pointer as we checked pointers are
 				// 32 bits wide and the key is 32 bits wide also.
 				*(*unsafe.Pointer)(k) = nil
@@ -427,7 +428,7 @@ func evacuate_fast32(t *maptype, h *hmap, oldbucket uintptr) {
 				dst.b.tophash[dst.i&(bucketCnt-1)] = top // mask dst.i as an optimization, to avoid a bounds check
 
 				// Copy key.
-				if sys.PtrSize == 4 && t.key.ptrdata != 0 && writeBarrier.enabled {
+				if goarch.PtrSize == 4 && t.key.ptrdata != 0 && writeBarrier.enabled {
 					// Write with a write barrier.
 					*(*unsafe.Pointer)(dst.k) = *(*unsafe.Pointer)(k)
 				} else {
diff --git a/src/runtime/map_fast64.go b/src/runtime/map_fast64.go
index f1368dc774e..69d8872885a 100644
--- a/src/runtime/map_fast64.go
+++ b/src/runtime/map_fast64.go
@@ -5,14 +5,15 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
 func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast64))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess1_fast64))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0])
@@ -52,7 +53,7 @@ func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
 func mapaccess2_fast64(t *maptype, h *hmap, key uint64) (unsafe.Pointer, bool) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast64))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess2_fast64))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0]), false
@@ -95,7 +96,7 @@ func mapassign_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast64))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapassign_fast64))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map writes")
@@ -185,7 +186,7 @@ func mapassign_fast64ptr(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast64))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapassign_fast64))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map writes")
@@ -272,7 +273,7 @@ done:
 func mapdelete_fast64(t *maptype, h *hmap, key uint64) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapdelete_fast64))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapdelete_fast64))
 	}
 	if h == nil || h.count == 0 {
 		return
@@ -300,7 +301,7 @@ search:
 			}
 			// Only clear key if there are pointers in it.
 			if t.key.ptrdata != 0 {
-				if sys.PtrSize == 8 {
+				if goarch.PtrSize == 8 {
 					*(*unsafe.Pointer)(k) = nil
 				} else {
 					// There are three ways to squeeze at one ore more 32 bit pointers into 64 bits.
@@ -430,7 +431,7 @@ func evacuate_fast64(t *maptype, h *hmap, oldbucket uintptr) {
 
 				// Copy key.
 				if t.key.ptrdata != 0 && writeBarrier.enabled {
-					if sys.PtrSize == 8 {
+					if goarch.PtrSize == 8 {
 						// Write with a write barrier.
 						*(*unsafe.Pointer)(dst.k) = *(*unsafe.Pointer)(k)
 					} else {
diff --git a/src/runtime/map_faststr.go b/src/runtime/map_faststr.go
index 0673dd39c8f..4dca882c636 100644
--- a/src/runtime/map_faststr.go
+++ b/src/runtime/map_faststr.go
@@ -5,14 +5,15 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
 func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_faststr))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess1_faststr))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0])
@@ -26,7 +27,7 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 		b := (*bmap)(h.buckets)
 		if key.len < 32 {
 			// short key, doing lots of comparisons is ok
-			for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+			for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 				k := (*stringStruct)(kptr)
 				if k.len != key.len || isEmpty(b.tophash[i]) {
 					if b.tophash[i] == emptyRest {
@@ -35,14 +36,14 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 					continue
 				}
 				if k.str == key.str || memequal(k.str, key.str, uintptr(key.len)) {
-					return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize))
+					return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize))
 				}
 			}
 			return unsafe.Pointer(&zeroVal[0])
 		}
 		// long key, try not to do more comparisons than necessary
 		keymaybe := uintptr(bucketCnt)
-		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 			k := (*stringStruct)(kptr)
 			if k.len != key.len || isEmpty(b.tophash[i]) {
 				if b.tophash[i] == emptyRest {
@@ -51,7 +52,7 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 				continue
 			}
 			if k.str == key.str {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize))
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize))
 			}
 			// check first 4 bytes
 			if *((*[4]byte)(key.str)) != *((*[4]byte)(k.str)) {
@@ -68,9 +69,9 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 			keymaybe = i
 		}
 		if keymaybe != bucketCnt {
-			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*sys.PtrSize))
+			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*goarch.PtrSize))
 			if memequal(k.str, key.str, uintptr(key.len)) {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+keymaybe*uintptr(t.elemsize))
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+keymaybe*uintptr(t.elemsize))
 			}
 		}
 		return unsafe.Pointer(&zeroVal[0])
@@ -91,13 +92,13 @@ dohash:
 	}
 	top := tophash(hash)
 	for ; b != nil; b = b.overflow(t) {
-		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 			k := (*stringStruct)(kptr)
 			if k.len != key.len || b.tophash[i] != top {
 				continue
 			}
 			if k.str == key.str || memequal(k.str, key.str, uintptr(key.len)) {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize))
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize))
 			}
 		}
 	}
@@ -107,7 +108,7 @@ dohash:
 func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_faststr))
+		racereadpc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapaccess2_faststr))
 	}
 	if h == nil || h.count == 0 {
 		return unsafe.Pointer(&zeroVal[0]), false
@@ -121,7 +122,7 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
 		b := (*bmap)(h.buckets)
 		if key.len < 32 {
 			// short key, doing lots of comparisons is ok
-			for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+			for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 				k := (*stringStruct)(kptr)
 				if k.len != key.len || isEmpty(b.tophash[i]) {
 					if b.tophash[i] == emptyRest {
@@ -130,14 +131,14 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
 					continue
 				}
 				if k.str == key.str || memequal(k.str, key.str, uintptr(key.len)) {
-					return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize)), true
+					return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize)), true
 				}
 			}
 			return unsafe.Pointer(&zeroVal[0]), false
 		}
 		// long key, try not to do more comparisons than necessary
 		keymaybe := uintptr(bucketCnt)
-		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 			k := (*stringStruct)(kptr)
 			if k.len != key.len || isEmpty(b.tophash[i]) {
 				if b.tophash[i] == emptyRest {
@@ -146,7 +147,7 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
 				continue
 			}
 			if k.str == key.str {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize)), true
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize)), true
 			}
 			// check first 4 bytes
 			if *((*[4]byte)(key.str)) != *((*[4]byte)(k.str)) {
@@ -163,9 +164,9 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
 			keymaybe = i
 		}
 		if keymaybe != bucketCnt {
-			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*sys.PtrSize))
+			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*goarch.PtrSize))
 			if memequal(k.str, key.str, uintptr(key.len)) {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+keymaybe*uintptr(t.elemsize)), true
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+keymaybe*uintptr(t.elemsize)), true
 			}
 		}
 		return unsafe.Pointer(&zeroVal[0]), false
@@ -186,13 +187,13 @@ dohash:
 	}
 	top := tophash(hash)
 	for ; b != nil; b = b.overflow(t) {
-		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 			k := (*stringStruct)(kptr)
 			if k.len != key.len || b.tophash[i] != top {
 				continue
 			}
 			if k.str == key.str || memequal(k.str, key.str, uintptr(key.len)) {
-				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize)), true
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize)), true
 			}
 		}
 	}
@@ -205,7 +206,7 @@ func mapassign_faststr(t *maptype, h *hmap, s string) unsafe.Pointer {
 	}
 	if raceenabled {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_faststr))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapassign_faststr))
 	}
 	if h.flags&hashWriting != 0 {
 		throw("concurrent map writes")
@@ -245,7 +246,7 @@ bucketloop:
 				}
 				continue
 			}
-			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*sys.PtrSize))
+			k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*goarch.PtrSize))
 			if k.len != key.len {
 				continue
 			}
@@ -283,13 +284,13 @@ bucketloop:
 	}
 	insertb.tophash[inserti&(bucketCnt-1)] = top // mask inserti to avoid bounds checks
 
-	insertk = add(unsafe.Pointer(insertb), dataOffset+inserti*2*sys.PtrSize)
+	insertk = add(unsafe.Pointer(insertb), dataOffset+inserti*2*goarch.PtrSize)
 	// store new key at insert position
 	*((*stringStruct)(insertk)) = *key
 	h.count++
 
 done:
-	elem := add(unsafe.Pointer(insertb), dataOffset+bucketCnt*2*sys.PtrSize+inserti*uintptr(t.elemsize))
+	elem := add(unsafe.Pointer(insertb), dataOffset+bucketCnt*2*goarch.PtrSize+inserti*uintptr(t.elemsize))
 	if h.flags&hashWriting == 0 {
 		throw("concurrent map writes")
 	}
@@ -300,7 +301,7 @@ done:
 func mapdelete_faststr(t *maptype, h *hmap, ky string) {
 	if raceenabled && h != nil {
 		callerpc := getcallerpc()
-		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapdelete_faststr))
+		racewritepc(unsafe.Pointer(h), callerpc, abi.FuncPCABIInternal(mapdelete_faststr))
 	}
 	if h == nil || h.count == 0 {
 		return
@@ -324,7 +325,7 @@ func mapdelete_faststr(t *maptype, h *hmap, ky string) {
 	top := tophash(hash)
 search:
 	for ; b != nil; b = b.overflow(t) {
-		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*sys.PtrSize) {
+		for i, kptr := uintptr(0), b.keys(); i < bucketCnt; i, kptr = i+1, add(kptr, 2*goarch.PtrSize) {
 			k := (*stringStruct)(kptr)
 			if k.len != key.len || b.tophash[i] != top {
 				continue
@@ -334,7 +335,7 @@ search:
 			}
 			// Clear key's pointer.
 			k.str = nil
-			e := add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.elemsize))
+			e := add(unsafe.Pointer(b), dataOffset+bucketCnt*2*goarch.PtrSize+i*uintptr(t.elemsize))
 			if t.elem.ptrdata != 0 {
 				memclrHasPointers(e, t.elem.size)
 			} else {
@@ -410,7 +411,7 @@ func evacuate_faststr(t *maptype, h *hmap, oldbucket uintptr) {
 		x := &xy[0]
 		x.b = (*bmap)(add(h.buckets, oldbucket*uintptr(t.bucketsize)))
 		x.k = add(unsafe.Pointer(x.b), dataOffset)
-		x.e = add(x.k, bucketCnt*2*sys.PtrSize)
+		x.e = add(x.k, bucketCnt*2*goarch.PtrSize)
 
 		if !h.sameSizeGrow() {
 			// Only calculate y pointers if we're growing bigger.
@@ -418,13 +419,13 @@ func evacuate_faststr(t *maptype, h *hmap, oldbucket uintptr) {
 			y := &xy[1]
 			y.b = (*bmap)(add(h.buckets, (oldbucket+newbit)*uintptr(t.bucketsize)))
 			y.k = add(unsafe.Pointer(y.b), dataOffset)
-			y.e = add(y.k, bucketCnt*2*sys.PtrSize)
+			y.e = add(y.k, bucketCnt*2*goarch.PtrSize)
 		}
 
 		for ; b != nil; b = b.overflow(t) {
 			k := add(unsafe.Pointer(b), dataOffset)
-			e := add(k, bucketCnt*2*sys.PtrSize)
-			for i := 0; i < bucketCnt; i, k, e = i+1, add(k, 2*sys.PtrSize), add(e, uintptr(t.elemsize)) {
+			e := add(k, bucketCnt*2*goarch.PtrSize)
+			for i := 0; i < bucketCnt; i, k, e = i+1, add(k, 2*goarch.PtrSize), add(e, uintptr(t.elemsize)) {
 				top := b.tophash[i]
 				if isEmpty(top) {
 					b.tophash[i] = evacuatedEmpty
@@ -450,7 +451,7 @@ func evacuate_faststr(t *maptype, h *hmap, oldbucket uintptr) {
 					dst.b = h.newoverflow(t, dst.b)
 					dst.i = 0
 					dst.k = add(unsafe.Pointer(dst.b), dataOffset)
-					dst.e = add(dst.k, bucketCnt*2*sys.PtrSize)
+					dst.e = add(dst.k, bucketCnt*2*goarch.PtrSize)
 				}
 				dst.b.tophash[dst.i&(bucketCnt-1)] = top // mask dst.i as an optimization, to avoid a bounds check
 
@@ -463,7 +464,7 @@ func evacuate_faststr(t *maptype, h *hmap, oldbucket uintptr) {
 				// key or elem arrays.  That's ok, as we have the overflow pointer
 				// at the end of the bucket to protect against pointing past the
 				// end of the bucket.
-				dst.k = add(dst.k, 2*sys.PtrSize)
+				dst.k = add(dst.k, 2*goarch.PtrSize)
 				dst.e = add(dst.e, uintptr(t.elemsize))
 			}
 		}
diff --git a/src/runtime/map_test.go b/src/runtime/map_test.go
index 302b3c23c12..24556b4093c 100644
--- a/src/runtime/map_test.go
+++ b/src/runtime/map_test.go
@@ -6,10 +6,10 @@ package runtime_test
 
 import (
 	"fmt"
+	"internal/goarch"
 	"math"
 	"reflect"
 	"runtime"
-	"runtime/internal/sys"
 	"sort"
 	"strconv"
 	"strings"
@@ -21,7 +21,7 @@ func TestHmapSize(t *testing.T) {
 	// The structure of hmap is defined in runtime/map.go
 	// and in cmd/compile/internal/gc/reflect.go and must be in sync.
 	// The size of hmap should be 48 bytes on 64 bit and 28 bytes on 32 bit platforms.
-	var hmapSize = uintptr(8 + 5*sys.PtrSize)
+	var hmapSize = uintptr(8 + 5*goarch.PtrSize)
 	if runtime.RuntimeHmapSize != hmapSize {
 		t.Errorf("sizeof(runtime.hmap{})==%d, want %d", runtime.RuntimeHmapSize, hmapSize)
 	}
diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go
index 4994347bdeb..3fd1cca42cc 100644
--- a/src/runtime/mbarrier.go
+++ b/src/runtime/mbarrier.go
@@ -15,7 +15,7 @@ package runtime
 
 import (
 	"internal/abi"
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -177,8 +177,8 @@ func typedmemmove(typ *_type, dst, src unsafe.Pointer) {
 //go:linkname reflect_typedmemmove reflect.typedmemmove
 func reflect_typedmemmove(typ *_type, dst, src unsafe.Pointer) {
 	if raceenabled {
-		raceWriteObjectPC(typ, dst, getcallerpc(), funcPC(reflect_typedmemmove))
-		raceReadObjectPC(typ, src, getcallerpc(), funcPC(reflect_typedmemmove))
+		raceWriteObjectPC(typ, dst, getcallerpc(), abi.FuncPCABIInternal(reflect_typedmemmove))
+		raceReadObjectPC(typ, src, getcallerpc(), abi.FuncPCABIInternal(reflect_typedmemmove))
 	}
 	if msanenabled {
 		msanwrite(dst, typ.size)
@@ -197,11 +197,11 @@ func reflectlite_typedmemmove(typ *_type, dst, src unsafe.Pointer) {
 // off must be a multiple of sys.PtrSize.
 //go:linkname reflect_typedmemmovepartial reflect.typedmemmovepartial
 func reflect_typedmemmovepartial(typ *_type, dst, src unsafe.Pointer, off, size uintptr) {
-	if writeBarrier.needed && typ.ptrdata > off && size >= sys.PtrSize {
-		if off&(sys.PtrSize-1) != 0 {
+	if writeBarrier.needed && typ.ptrdata > off && size >= goarch.PtrSize {
+		if off&(goarch.PtrSize-1) != 0 {
 			panic("reflect: internal error: misaligned offset")
 		}
-		pwsize := alignDown(size, sys.PtrSize)
+		pwsize := alignDown(size, goarch.PtrSize)
 		if poff := typ.ptrdata - off; pwsize > poff {
 			pwsize = poff
 		}
@@ -225,7 +225,7 @@ func reflect_typedmemmovepartial(typ *_type, dst, src unsafe.Pointer, off, size
 //
 //go:nosplit
 func reflectcallmove(typ *_type, dst, src unsafe.Pointer, size uintptr, regs *abi.RegArgs) {
-	if writeBarrier.needed && typ != nil && typ.ptrdata != 0 && size >= sys.PtrSize {
+	if writeBarrier.needed && typ != nil && typ.ptrdata != 0 && size >= goarch.PtrSize {
 		bulkBarrierPreWrite(uintptr(dst), uintptr(src), size)
 	}
 	memmove(dst, src, size)
@@ -254,7 +254,7 @@ func typedslicecopy(typ *_type, dstPtr unsafe.Pointer, dstLen int, srcPtr unsafe
 	// code and needs its own instrumentation.
 	if raceenabled {
 		callerpc := getcallerpc()
-		pc := funcPC(slicecopy)
+		pc := abi.FuncPCABIInternal(slicecopy)
 		racewriterangepc(dstPtr, uintptr(n)*typ.size, callerpc, pc)
 		racereadrangepc(srcPtr, uintptr(n)*typ.size, callerpc, pc)
 	}
diff --git a/src/runtime/mbitmap.go b/src/runtime/mbitmap.go
index 32b8db7a502..9363409e361 100644
--- a/src/runtime/mbitmap.go
+++ b/src/runtime/mbitmap.go
@@ -46,6 +46,7 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -326,8 +327,8 @@ func heapBitsForAddr(addr uintptr) (h heapBits) {
 		// we expect to crash in the caller.
 		return
 	}
-	h.bitp = &ha.bitmap[(addr/(sys.PtrSize*4))%heapArenaBitmapBytes]
-	h.shift = uint32((addr / sys.PtrSize) & 3)
+	h.bitp = &ha.bitmap[(addr/(goarch.PtrSize*4))%heapArenaBitmapBytes]
+	h.shift = uint32((addr / goarch.PtrSize) & 3)
 	h.arena = uint32(arena)
 	h.last = &ha.bitmap[len(ha.bitmap)-1]
 	return
@@ -386,10 +387,10 @@ func findObject(p, refBase, refOff uintptr) (base uintptr, s *mspan, objIndex ui
 	// If s is nil, the virtual address has never been part of the heap.
 	// This pointer may be to some mmap'd region, so we allow it.
 	if s == nil {
-		if GOARCH == "amd64" && p == clobberdeadPtr && debug.invalidptr != 0 {
-			// Crash if clobberdeadPtr is seen. Only on AMD64 for now, as
-			// it is the only platform where compiler's clobberdead mode is
-			// implemented. On AMD64 clobberdeadPtr cannot be a valid address.
+		if (GOARCH == "amd64" || GOARCH == "arm64") && p == clobberdeadPtr && debug.invalidptr != 0 {
+			// Crash if clobberdeadPtr is seen. Only on AMD64 and ARM64 for now,
+			// as they are the only platform where compiler's clobberdead mode is
+			// implemented. On these platforms clobberdeadPtr cannot be a valid address.
 			badPointer(s, p, refBase, refOff)
 		}
 		return
@@ -557,7 +558,7 @@ func (h heapBits) isPointer() bool {
 //
 //go:nosplit
 func bulkBarrierPreWrite(dst, src, size uintptr) {
-	if (dst|src|size)&(sys.PtrSize-1) != 0 {
+	if (dst|src|size)&(goarch.PtrSize-1) != 0 {
 		throw("bulkBarrierPreWrite: unaligned arguments")
 	}
 	if !writeBarrier.needed {
@@ -592,7 +593,7 @@ func bulkBarrierPreWrite(dst, src, size uintptr) {
 	buf := &getg().m.p.ptr().wbBuf
 	h := heapBitsForAddr(dst)
 	if src == 0 {
-		for i := uintptr(0); i < size; i += sys.PtrSize {
+		for i := uintptr(0); i < size; i += goarch.PtrSize {
 			if h.isPointer() {
 				dstx := (*uintptr)(unsafe.Pointer(dst + i))
 				if !buf.putFast(*dstx, 0) {
@@ -602,7 +603,7 @@ func bulkBarrierPreWrite(dst, src, size uintptr) {
 			h = h.next()
 		}
 	} else {
-		for i := uintptr(0); i < size; i += sys.PtrSize {
+		for i := uintptr(0); i < size; i += goarch.PtrSize {
 			if h.isPointer() {
 				dstx := (*uintptr)(unsafe.Pointer(dst + i))
 				srcx := (*uintptr)(unsafe.Pointer(src + i))
@@ -625,7 +626,7 @@ func bulkBarrierPreWrite(dst, src, size uintptr) {
 // created and zeroed with malloc.
 //go:nosplit
 func bulkBarrierPreWriteSrcOnly(dst, src, size uintptr) {
-	if (dst|src|size)&(sys.PtrSize-1) != 0 {
+	if (dst|src|size)&(goarch.PtrSize-1) != 0 {
 		throw("bulkBarrierPreWrite: unaligned arguments")
 	}
 	if !writeBarrier.needed {
@@ -633,7 +634,7 @@ func bulkBarrierPreWriteSrcOnly(dst, src, size uintptr) {
 	}
 	buf := &getg().m.p.ptr().wbBuf
 	h := heapBitsForAddr(dst)
-	for i := uintptr(0); i < size; i += sys.PtrSize {
+	for i := uintptr(0); i < size; i += goarch.PtrSize {
 		if h.isPointer() {
 			srcx := (*uintptr)(unsafe.Pointer(src + i))
 			if !buf.putFast(0, *srcx) {
@@ -653,17 +654,17 @@ func bulkBarrierPreWriteSrcOnly(dst, src, size uintptr) {
 //
 //go:nosplit
 func bulkBarrierBitmap(dst, src, size, maskOffset uintptr, bits *uint8) {
-	word := maskOffset / sys.PtrSize
+	word := maskOffset / goarch.PtrSize
 	bits = addb(bits, word/8)
 	mask := uint8(1) << (word % 8)
 
 	buf := &getg().m.p.ptr().wbBuf
-	for i := uintptr(0); i < size; i += sys.PtrSize {
+	for i := uintptr(0); i < size; i += goarch.PtrSize {
 		if mask == 0 {
 			bits = addb(bits, 1)
 			if *bits == 0 {
 				// Skip 8 words.
-				i += 7 * sys.PtrSize
+				i += 7 * goarch.PtrSize
 				continue
 			}
 			mask = 1
@@ -720,8 +721,8 @@ func typeBitsBulkBarrier(typ *_type, dst, src, size uintptr) {
 	ptrmask := typ.gcdata
 	buf := &getg().m.p.ptr().wbBuf
 	var bits uint32
-	for i := uintptr(0); i < typ.ptrdata; i += sys.PtrSize {
-		if i&(sys.PtrSize*8-1) == 0 {
+	for i := uintptr(0); i < typ.ptrdata; i += goarch.PtrSize {
+		if i&(goarch.PtrSize*8-1) == 0 {
 			bits = uint32(*ptrmask)
 			ptrmask = addb(ptrmask, 1)
 		} else {
@@ -751,14 +752,14 @@ func typeBitsBulkBarrier(typ *_type, dst, src, size uintptr) {
 // Otherwise, it initializes all words to scalar/dead.
 func (h heapBits) initSpan(s *mspan) {
 	// Clear bits corresponding to objects.
-	nw := (s.npages << _PageShift) / sys.PtrSize
+	nw := (s.npages << _PageShift) / goarch.PtrSize
 	if nw%wordsPerBitmapByte != 0 {
 		throw("initSpan: unaligned length")
 	}
 	if h.shift != 0 {
 		throw("initSpan: unaligned base")
 	}
-	isPtrs := sys.PtrSize == 8 && s.elemsize == sys.PtrSize
+	isPtrs := goarch.PtrSize == 8 && s.elemsize == goarch.PtrSize
 	for nw > 0 {
 		hNext, anw := h.forwardOrBoundary(nw)
 		nbyte := anw / wordsPerBitmapByte
@@ -836,7 +837,7 @@ func heapBitsSetType(x, size, dataSize uintptr, typ *_type) {
 	// The checks for size == sys.PtrSize and size == 2*sys.PtrSize can therefore
 	// assume that dataSize == size without checking it explicitly.
 
-	if sys.PtrSize == 8 && size == sys.PtrSize {
+	if goarch.PtrSize == 8 && size == goarch.PtrSize {
 		// It's one word and it has pointers, it must be a pointer.
 		// Since all allocated one-word objects are pointers
 		// (non-pointers are aggregated into tinySize allocations),
@@ -862,8 +863,8 @@ func heapBitsSetType(x, size, dataSize uintptr, typ *_type) {
 	// objects are at least 4 words long and that their bitmaps start either at the beginning
 	// of a bitmap byte, or half-way in (h.shift of 0 and 2 respectively).
 
-	if size == 2*sys.PtrSize {
-		if typ.size == sys.PtrSize {
+	if size == 2*goarch.PtrSize {
+		if typ.size == goarch.PtrSize {
 			// We're allocating a block big enough to hold two pointers.
 			// On 64-bit, that means the actual object must be two pointers,
 			// or else we'd have used the one-pointer-sized block.
@@ -872,7 +873,7 @@ func heapBitsSetType(x, size, dataSize uintptr, typ *_type) {
 			// just the smallest block available. Distinguish by checking dataSize.
 			// (In general the number of instances of typ being allocated is
 			// dataSize/typ.size.)
-			if sys.PtrSize == 4 && dataSize == sys.PtrSize {
+			if goarch.PtrSize == 4 && dataSize == goarch.PtrSize {
 				// 1 pointer object. On 32-bit machines clear the bit for the
 				// unused second word.
 				*h.bitp &^= (bitPointer | bitScan | (bitPointer|bitScan)<> h.shift) & (bitPointer | bitScan)
@@ -1446,7 +1447,7 @@ Phase4:
 				print("initial bits h0.bitp=", h0.bitp, " h0.shift=", h0.shift, "\n")
 				print("current bits h.bitp=", h.bitp, " h.shift=", h.shift, " *h.bitp=", hex(*h.bitp), "\n")
 				print("ptrmask=", ptrmask, " p=", p, " endp=", endp, " endnb=", endnb, " pbits=", hex(pbits), " b=", hex(b), " nb=", nb, "\n")
-				println("at word", i, "offset", i*sys.PtrSize, "have", hex(have), "want", hex(want))
+				println("at word", i, "offset", i*goarch.PtrSize, "have", hex(have), "want", hex(want))
 				if typ.kind&kindGCProg != 0 {
 					println("GC program:")
 					dumpGCProg(addb(typ.gcdata, 4))
@@ -1477,14 +1478,14 @@ var debugPtrmask struct {
 // so that the relevant bitmap bytes are not shared with surrounding
 // objects.
 func heapBitsSetTypeGCProg(h heapBits, progSize, elemSize, dataSize, allocSize uintptr, prog *byte) {
-	if sys.PtrSize == 8 && allocSize%(4*sys.PtrSize) != 0 {
+	if goarch.PtrSize == 8 && allocSize%(4*goarch.PtrSize) != 0 {
 		// Alignment will be wrong.
 		throw("heapBitsSetTypeGCProg: small allocation")
 	}
 	var totalBits uintptr
 	if elemSize == dataSize {
 		totalBits = runGCProg(prog, nil, h.bitp, 2)
-		if totalBits*sys.PtrSize != progSize {
+		if totalBits*goarch.PtrSize != progSize {
 			println("runtime: heapBitsSetTypeGCProg: total bits", totalBits, "but progSize", progSize)
 			throw("heapBitsSetTypeGCProg: unexpected bit count")
 		}
@@ -1499,7 +1500,7 @@ func heapBitsSetTypeGCProg(h heapBits, progSize, elemSize, dataSize, allocSize u
 		// repeats that first element to fill the array.
 		var trailer [40]byte // 3 varints (max 10 each) + some bytes
 		i := 0
-		if n := elemSize/sys.PtrSize - progSize/sys.PtrSize; n > 0 {
+		if n := elemSize/goarch.PtrSize - progSize/goarch.PtrSize; n > 0 {
 			// literal(0)
 			trailer[i] = 0x01
 			i++
@@ -1521,7 +1522,7 @@ func heapBitsSetTypeGCProg(h heapBits, progSize, elemSize, dataSize, allocSize u
 		// repeat(elemSize/ptrSize, count-1)
 		trailer[i] = 0x80
 		i++
-		n := elemSize / sys.PtrSize
+		n := elemSize / goarch.PtrSize
 		for ; n >= 0x80; n >>= 7 {
 			trailer[i] = byte(n | 0x80)
 			i++
@@ -1545,10 +1546,10 @@ func heapBitsSetTypeGCProg(h heapBits, progSize, elemSize, dataSize, allocSize u
 		// last element. This will cause the code below to
 		// memclr the dead section of the final array element,
 		// so that scanobject can stop early in the final element.
-		totalBits = (elemSize*(count-1) + progSize) / sys.PtrSize
+		totalBits = (elemSize*(count-1) + progSize) / goarch.PtrSize
 	}
 	endProg := unsafe.Pointer(addb(h.bitp, (totalBits+3)/4))
-	endAlloc := unsafe.Pointer(addb(h.bitp, allocSize/sys.PtrSize/wordsPerBitmapByte))
+	endAlloc := unsafe.Pointer(addb(h.bitp, allocSize/goarch.PtrSize/wordsPerBitmapByte))
 	memclrNoHeapPointers(endProg, uintptr(endAlloc)-uintptr(endProg))
 }
 
@@ -1556,7 +1557,7 @@ func heapBitsSetTypeGCProg(h heapBits, progSize, elemSize, dataSize, allocSize u
 // size the size of the region described by prog, in bytes.
 // The resulting bitvector will have no more than size/sys.PtrSize bits.
 func progToPointerMask(prog *byte, size uintptr) bitvector {
-	n := (size/sys.PtrSize + 7) / 8
+	n := (size/goarch.PtrSize + 7) / 8
 	x := (*[1 << 30]byte)(persistentalloc(n+1, 1, &memstats.buckhash_sys))[:n+1]
 	x[len(x)-1] = 0xa1 // overflow check sentinel
 	n = runGCProg(prog, nil, &x[0], 1)
@@ -1691,7 +1692,7 @@ Run:
 		// the pattern to a bit buffer holding at most 7 bits (a partial byte)
 		// it will not overflow.
 		src := dst
-		const maxBits = sys.PtrSize*8 - 7
+		const maxBits = goarch.PtrSize*8 - 7
 		if n <= maxBits {
 			// Start with bits in output buffer.
 			pattern := bits
@@ -1744,7 +1745,7 @@ Run:
 				nb := npattern
 				if nb+nb <= maxBits {
 					// Double pattern until the whole uintptr is filled.
-					for nb <= sys.PtrSize*8 {
+					for nb <= goarch.PtrSize*8 {
 						b |= b << nb
 						nb += nb
 					}
@@ -1872,7 +1873,7 @@ Run:
 // The result must be deallocated with dematerializeGCProg.
 func materializeGCProg(ptrdata uintptr, prog *byte) *mspan {
 	// Each word of ptrdata needs one bit in the bitmap.
-	bitmapBytes := divRoundUp(ptrdata, 8*sys.PtrSize)
+	bitmapBytes := divRoundUp(ptrdata, 8*goarch.PtrSize)
 	// Compute the number of pages needed for bitmapBytes.
 	pages := divRoundUp(bitmapBytes, pageSize)
 	s := mheap_.allocManual(pages, spanAllocPtrScalarBits)
@@ -1945,7 +1946,7 @@ func getgcmaskcb(frame *stkframe, ctxt unsafe.Pointer) bool {
 func reflect_gcbits(x interface{}) []byte {
 	ret := getgcmask(x)
 	typ := (*ptrtype)(unsafe.Pointer(efaceOf(&x)._type)).elem
-	nptr := typ.ptrdata / sys.PtrSize
+	nptr := typ.ptrdata / goarch.PtrSize
 	for uintptr(len(ret)) > nptr && ret[len(ret)-1] == 0 {
 		ret = ret[:len(ret)-1]
 	}
@@ -1965,10 +1966,10 @@ func getgcmask(ep interface{}) (mask []byte) {
 		if datap.data <= uintptr(p) && uintptr(p) < datap.edata {
 			bitmap := datap.gcdatamask.bytedata
 			n := (*ptrtype)(unsafe.Pointer(t)).elem.size
-			mask = make([]byte, n/sys.PtrSize)
-			for i := uintptr(0); i < n; i += sys.PtrSize {
-				off := (uintptr(p) + i - datap.data) / sys.PtrSize
-				mask[i/sys.PtrSize] = (*addb(bitmap, off/8) >> (off % 8)) & 1
+			mask = make([]byte, n/goarch.PtrSize)
+			for i := uintptr(0); i < n; i += goarch.PtrSize {
+				off := (uintptr(p) + i - datap.data) / goarch.PtrSize
+				mask[i/goarch.PtrSize] = (*addb(bitmap, off/8) >> (off % 8)) & 1
 			}
 			return
 		}
@@ -1977,10 +1978,10 @@ func getgcmask(ep interface{}) (mask []byte) {
 		if datap.bss <= uintptr(p) && uintptr(p) < datap.ebss {
 			bitmap := datap.gcbssmask.bytedata
 			n := (*ptrtype)(unsafe.Pointer(t)).elem.size
-			mask = make([]byte, n/sys.PtrSize)
-			for i := uintptr(0); i < n; i += sys.PtrSize {
-				off := (uintptr(p) + i - datap.bss) / sys.PtrSize
-				mask[i/sys.PtrSize] = (*addb(bitmap, off/8) >> (off % 8)) & 1
+			mask = make([]byte, n/goarch.PtrSize)
+			for i := uintptr(0); i < n; i += goarch.PtrSize {
+				off := (uintptr(p) + i - datap.bss) / goarch.PtrSize
+				mask[i/goarch.PtrSize] = (*addb(bitmap, off/8) >> (off % 8)) & 1
 			}
 			return
 		}
@@ -1990,13 +1991,13 @@ func getgcmask(ep interface{}) (mask []byte) {
 	if base, s, _ := findObject(uintptr(p), 0, 0); base != 0 {
 		hbits := heapBitsForAddr(base)
 		n := s.elemsize
-		mask = make([]byte, n/sys.PtrSize)
-		for i := uintptr(0); i < n; i += sys.PtrSize {
+		mask = make([]byte, n/goarch.PtrSize)
+		for i := uintptr(0); i < n; i += goarch.PtrSize {
 			if hbits.isPointer() {
-				mask[i/sys.PtrSize] = 1
+				mask[i/goarch.PtrSize] = 1
 			}
 			if !hbits.morePointers() {
-				mask = mask[:i/sys.PtrSize]
+				mask = mask[:i/goarch.PtrSize]
 				break
 			}
 			hbits = hbits.next()
@@ -2015,12 +2016,12 @@ func getgcmask(ep interface{}) (mask []byte) {
 			if locals.n == 0 {
 				return
 			}
-			size := uintptr(locals.n) * sys.PtrSize
+			size := uintptr(locals.n) * goarch.PtrSize
 			n := (*ptrtype)(unsafe.Pointer(t)).elem.size
-			mask = make([]byte, n/sys.PtrSize)
-			for i := uintptr(0); i < n; i += sys.PtrSize {
-				off := (uintptr(p) + i - frame.varp + size) / sys.PtrSize
-				mask[i/sys.PtrSize] = locals.ptrbit(off)
+			mask = make([]byte, n/goarch.PtrSize)
+			for i := uintptr(0); i < n; i += goarch.PtrSize {
+				off := (uintptr(p) + i - frame.varp + size) / goarch.PtrSize
+				mask[i/goarch.PtrSize] = locals.ptrbit(off)
 			}
 		}
 		return
diff --git a/src/runtime/mcheckmark.go b/src/runtime/mcheckmark.go
index ba80ac1bdf4..1dd28585f1c 100644
--- a/src/runtime/mcheckmark.go
+++ b/src/runtime/mcheckmark.go
@@ -13,8 +13,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -24,7 +24,7 @@ import (
 // allocation.
 //
 //go:notinheap
-type checkmarksMap [heapArenaBytes / sys.PtrSize / 8]uint8
+type checkmarksMap [heapArenaBytes / goarch.PtrSize / 8]uint8
 
 // If useCheckmark is true, marking of an object uses the checkmark
 // bits instead of the standard mark bits.
diff --git a/src/runtime/memclr_386.s b/src/runtime/memclr_386.s
index d2ef17f7cee..046c3441198 100644
--- a/src/runtime/memclr_386.s
+++ b/src/runtime/memclr_386.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !plan9
 // +build !plan9
 
 #include "go_asm.h"
diff --git a/src/runtime/memclr_amd64.s b/src/runtime/memclr_amd64.s
index 5d2bebb901b..918a4b9e0e4 100644
--- a/src/runtime/memclr_amd64.s
+++ b/src/runtime/memclr_amd64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !plan9
 // +build !plan9
 
 #include "go_asm.h"
@@ -12,14 +13,9 @@
 // func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
 // ABIInternal for performance.
 TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT, $0-16
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = ptr
 	// BX = n
 	MOVQ	AX, DI	// DI = ptr
-#else
-	MOVQ	ptr+0(FP), DI
-	MOVQ	n+8(FP), BX
-#endif
 	XORQ	AX, AX
 
 	// MOVOU seems always faster than REP STOSQ.
@@ -36,9 +32,6 @@ tail:
 	JE	_8
 	CMPQ	BX, $16
 	JBE	_9through16
-#ifndef GOEXPERIMENT_regabig
-	PXOR	X15, X15
-#endif
 	CMPQ	BX, $32
 	JBE	_17through32
 	CMPQ	BX, $64
diff --git a/src/runtime/memclr_arm64.s b/src/runtime/memclr_arm64.s
index c1a0dcef584..b80cca6a1cd 100644
--- a/src/runtime/memclr_arm64.s
+++ b/src/runtime/memclr_arm64.s
@@ -8,9 +8,11 @@
 
 // func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
 // Also called from assembly in sys_windows_arm64.s without g (but using Go stack convention).
-TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-16
+TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-16
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	ptr+0(FP), R0
 	MOVD	n+8(FP), R1
+#endif
 
 	CMP	$16, R1
 	// If n is equal to 16 bytes, use zero_exact_16 to zero
diff --git a/src/runtime/memclr_mips64x.s b/src/runtime/memclr_mips64x.s
index d7a3251e204..bc037013fe7 100644
--- a/src/runtime/memclr_mips64x.s
+++ b/src/runtime/memclr_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
diff --git a/src/runtime/memclr_mipsx.s b/src/runtime/memclr_mipsx.s
index eb2a8a7219c..3d21c3c414c 100644
--- a/src/runtime/memclr_mipsx.s
+++ b/src/runtime/memclr_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/runtime/memclr_ppc64x.s b/src/runtime/memclr_ppc64x.s
index 75126208942..65639322b2a 100644
--- a/src/runtime/memclr_ppc64x.s
+++ b/src/runtime/memclr_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/runtime/memmove_386.s b/src/runtime/memmove_386.s
index d99546c6336..1a43a1f724d 100644
--- a/src/runtime/memmove_386.s
+++ b/src/runtime/memmove_386.s
@@ -23,6 +23,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+//go:build !plan9
 // +build !plan9
 
 #include "go_asm.h"
diff --git a/src/runtime/memmove_amd64.s b/src/runtime/memmove_amd64.s
index f1e34035962..fa0c0e414f4 100644
--- a/src/runtime/memmove_amd64.s
+++ b/src/runtime/memmove_amd64.s
@@ -23,6 +23,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+//go:build !plan9
 // +build !plan9
 
 #include "go_asm.h"
@@ -33,18 +34,12 @@
 // func memmove(to, from unsafe.Pointer, n uintptr)
 // ABIInternal for performance.
 TEXT runtime·memmove(SB), NOSPLIT, $0-24
-#ifdef GOEXPERIMENT_regabiargs
 	// AX = to
 	// BX = from
 	// CX = n
 	MOVQ	AX, DI
 	MOVQ	BX, SI
 	MOVQ	CX, BX
-#else
-	MOVQ	to+0(FP), DI
-	MOVQ	from+8(FP), SI
-	MOVQ	n+16(FP), BX
-#endif
 
 	// REP instructions have a high startup cost, so we handle small sizes
 	// with some straightline code. The REP MOVSQ instruction is really fast
@@ -253,10 +248,8 @@ move_129through256:
 	MOVOU	X13, -48(DI)(BX*1)
 	MOVOU	X14, -32(DI)(BX*1)
 	MOVOU	X15, -16(DI)(BX*1)
-#ifdef GOEXPERIMENT_regabig
 	// X15 must be zero on return
 	PXOR	X15, X15
-#endif
 	RET
 move_256through2048:
 	SUBQ	$256, BX
@@ -296,10 +289,8 @@ move_256through2048:
 	LEAQ	256(SI), SI
 	LEAQ	256(DI), DI
 	JGE	move_256through2048
-#ifdef GOEXPERIMENT_regabig
 	// X15 must be zero on return
 	PXOR	X15, X15
-#endif
 	JMP	tail
 
 avxUnaligned:
diff --git a/src/runtime/memmove_arm64.s b/src/runtime/memmove_arm64.s
index 43d27629e5b..bee3b00c47d 100644
--- a/src/runtime/memmove_arm64.s
+++ b/src/runtime/memmove_arm64.s
@@ -26,10 +26,12 @@
 // The loop tail is handled by always copying 64 bytes from the end.
 
 // func memmove(to, from unsafe.Pointer, n uintptr)
-TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24
+TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24
+#ifndef GOEXPERIMENT_regabiargs
 	MOVD	to+0(FP), R0
 	MOVD	from+8(FP), R1
 	MOVD	n+16(FP), R2
+#endif
 	CBZ	R2, copy0
 
 	// Small copies: 1..16 bytes
diff --git a/src/runtime/memmove_mips64x.s b/src/runtime/memmove_mips64x.s
index 8a1b88afba7..fef3c6be827 100644
--- a/src/runtime/memmove_mips64x.s
+++ b/src/runtime/memmove_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "textflag.h"
diff --git a/src/runtime/memmove_mipsx.s b/src/runtime/memmove_mipsx.s
index 6c86558f8d2..cd02fc25c4b 100644
--- a/src/runtime/memmove_mipsx.s
+++ b/src/runtime/memmove_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "textflag.h"
diff --git a/src/runtime/memmove_ppc64x.s b/src/runtime/memmove_ppc64x.s
index dbd835506f6..fd16ad8129b 100644
--- a/src/runtime/memmove_ppc64x.s
+++ b/src/runtime/memmove_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "textflag.h"
diff --git a/src/runtime/mfinal.go b/src/runtime/mfinal.go
index fd318d49a8d..3cdb81e2fb9 100644
--- a/src/runtime/mfinal.go
+++ b/src/runtime/mfinal.go
@@ -8,8 +8,8 @@ package runtime
 
 import (
 	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -26,14 +26,14 @@ type finblock struct {
 	next    *finblock
 	cnt     uint32
 	_       int32
-	fin     [(_FinBlockSize - 2*sys.PtrSize - 2*4) / unsafe.Sizeof(finalizer{})]finalizer
+	fin     [(_FinBlockSize - 2*goarch.PtrSize - 2*4) / unsafe.Sizeof(finalizer{})]finalizer
 }
 
 var finlock mutex  // protects the following variables
 var fing *g        // goroutine that runs finalizers
 var finq *finblock // list of finalizers that are to be executed
 var finc *finblock // cache of free blocks
-var finptrmask [_FinBlockSize / sys.PtrSize / 8]byte
+var finptrmask [_FinBlockSize / goarch.PtrSize / 8]byte
 var fingwait bool
 var fingwake bool
 var allfin *finblock // list of all blocks
@@ -95,12 +95,12 @@ func queuefinalizer(p unsafe.Pointer, fn *funcval, nret uintptr, fint *_type, ot
 			if finptrmask[0] == 0 {
 				// Build pointer mask for Finalizer array in block.
 				// Check assumptions made in finalizer1 array above.
-				if (unsafe.Sizeof(finalizer{}) != 5*sys.PtrSize ||
+				if (unsafe.Sizeof(finalizer{}) != 5*goarch.PtrSize ||
 					unsafe.Offsetof(finalizer{}.fn) != 0 ||
-					unsafe.Offsetof(finalizer{}.arg) != sys.PtrSize ||
-					unsafe.Offsetof(finalizer{}.nret) != 2*sys.PtrSize ||
-					unsafe.Offsetof(finalizer{}.fint) != 3*sys.PtrSize ||
-					unsafe.Offsetof(finalizer{}.ot) != 4*sys.PtrSize) {
+					unsafe.Offsetof(finalizer{}.arg) != goarch.PtrSize ||
+					unsafe.Offsetof(finalizer{}.nret) != 2*goarch.PtrSize ||
+					unsafe.Offsetof(finalizer{}.fint) != 3*goarch.PtrSize ||
+					unsafe.Offsetof(finalizer{}.ot) != 4*goarch.PtrSize) {
 					throw("finalizer out of sync")
 				}
 				for i := range finptrmask {
@@ -432,7 +432,7 @@ okarg:
 	for _, t := range ft.out() {
 		nret = alignUp(nret, uintptr(t.align)) + uintptr(t.size)
 	}
-	nret = alignUp(nret, sys.PtrSize)
+	nret = alignUp(nret, goarch.PtrSize)
 
 	// make sure we have a finalizer goroutine
 	createfing()
@@ -466,6 +466,10 @@ okarg:
 // Without the KeepAlive call, the finalizer could run at the start of
 // syscall.Read, closing the file descriptor before syscall.Read makes
 // the actual system call.
+//
+// Note: KeepAlive should only be used to prevent finalizers from
+// running prematurely. In particular, when used with unsafe.Pointer,
+// the rules for valid uses of unsafe.Pointer still apply.
 func KeepAlive(x interface{}) {
 	// Introduce a use of x that the compiler can't eliminate.
 	// This makes sure x is alive on entry. We need x to be alive
diff --git a/src/runtime/mgc.go b/src/runtime/mgc.go
index 45856635353..34b5b482a35 100644
--- a/src/runtime/mgc.go
+++ b/src/runtime/mgc.go
@@ -167,22 +167,17 @@ func gcinit() {
 	lockInit(&work.wbufSpans.lock, lockRankWbufSpans)
 }
 
-// Temporary in order to enable register ABI work.
-// TODO(register args): convert back to local chan in gcenabled, passed to "go" stmts.
-var gcenable_setup chan int
-
 // gcenable is called after the bulk of the runtime initialization,
 // just before we're about to start letting user code run.
 // It kicks off the background sweeper goroutine, the background
 // scavenger goroutine, and enables GC.
 func gcenable() {
 	// Kick off sweeping and scavenging.
-	gcenable_setup = make(chan int, 2)
-	go bgsweep()
-	go bgscavenge()
-	<-gcenable_setup
-	<-gcenable_setup
-	gcenable_setup = nil
+	c := make(chan int, 2)
+	go bgsweep(c)
+	go bgscavenge(c)
+	<-c
+	<-c
 	memstats.enablegc = true // now that runtime is initialized, GC is okay
 }
 
@@ -1563,19 +1558,17 @@ func clearpools() {
 	sched.sudogcache = nil
 	unlock(&sched.sudoglock)
 
-	// Clear central defer pools.
+	// Clear central defer pool.
 	// Leave per-P pools alone, they have strictly bounded size.
 	lock(&sched.deferlock)
-	for i := range sched.deferpool {
-		// disconnect cached list before dropping it on the floor,
-		// so that a dangling ref to one entry does not pin all of them.
-		var d, dlink *_defer
-		for d = sched.deferpool[i]; d != nil; d = dlink {
-			dlink = d.link
-			d.link = nil
-		}
-		sched.deferpool[i] = nil
+	// disconnect cached list before dropping it on the floor,
+	// so that a dangling ref to one entry does not pin all of them.
+	var d, dlink *_defer
+	for d = sched.deferpool; d != nil; d = dlink {
+		dlink = d.link
+		d.link = nil
 	}
+	sched.deferpool = nil
 	unlock(&sched.deferlock)
 }
 
diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go
index 1fd0732d62d..874d9107209 100644
--- a/src/runtime/mgcmark.go
+++ b/src/runtime/mgcmark.go
@@ -7,8 +7,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -245,7 +245,7 @@ func markroot(gcw *gcWork, i uint32) {
 //
 //go:nowritebarrier
 func markrootBlock(b0, n0 uintptr, ptrmask0 *uint8, gcw *gcWork, shard int) {
-	if rootBlockBytes%(8*sys.PtrSize) != 0 {
+	if rootBlockBytes%(8*goarch.PtrSize) != 0 {
 		// This is necessary to pick byte offsets in ptrmask0.
 		throw("rootBlockBytes must be a multiple of 8*ptrSize")
 	}
@@ -258,7 +258,7 @@ func markrootBlock(b0, n0 uintptr, ptrmask0 *uint8, gcw *gcWork, shard int) {
 		return
 	}
 	b := b0 + off
-	ptrmask := (*uint8)(add(unsafe.Pointer(ptrmask0), uintptr(shard)*(rootBlockBytes/(8*sys.PtrSize))))
+	ptrmask := (*uint8)(add(unsafe.Pointer(ptrmask0), uintptr(shard)*(rootBlockBytes/(8*goarch.PtrSize))))
 	n := uintptr(rootBlockBytes)
 	if off+n > n0 {
 		n = n0 - off
@@ -372,7 +372,7 @@ func markrootSpans(gcw *gcWork, shard int) {
 				scanobject(p, gcw)
 
 				// The special itself is a root.
-				scanblock(uintptr(unsafe.Pointer(&spf.fn)), sys.PtrSize, &oneptrmask[0], gcw, nil)
+				scanblock(uintptr(unsafe.Pointer(&spf.fn)), goarch.PtrSize, &oneptrmask[0], gcw, nil)
 			}
 			unlock(&s.speciallock)
 		}
@@ -737,7 +737,7 @@ func scanstack(gp *g, gcw *gcWork) {
 	// register that gets moved back and forth between the
 	// register and sched.ctxt without a write barrier.
 	if gp.sched.ctxt != nil {
-		scanblock(uintptr(unsafe.Pointer(&gp.sched.ctxt)), sys.PtrSize, &oneptrmask[0], gcw, &state)
+		scanblock(uintptr(unsafe.Pointer(&gp.sched.ctxt)), goarch.PtrSize, &oneptrmask[0], gcw, &state)
 	}
 
 	// Scan the stack. Accumulate a list of stack objects.
@@ -750,26 +750,23 @@ func scanstack(gp *g, gcw *gcWork) {
 	// Find additional pointers that point into the stack from the heap.
 	// Currently this includes defers and panics. See also function copystack.
 
-	// Find and trace all defer arguments.
-	tracebackdefers(gp, scanframe, nil)
-
 	// Find and trace other pointers in defer records.
 	for d := gp._defer; d != nil; d = d.link {
 		if d.fn != nil {
-			// tracebackdefers above does not scan the func value, which could
-			// be a stack allocated closure. See issue 30453.
-			scanblock(uintptr(unsafe.Pointer(&d.fn)), sys.PtrSize, &oneptrmask[0], gcw, &state)
+			// Scan the func value, which could be a stack allocated closure.
+			// See issue 30453.
+			scanblock(uintptr(unsafe.Pointer(&d.fn)), goarch.PtrSize, &oneptrmask[0], gcw, &state)
 		}
 		if d.link != nil {
 			// The link field of a stack-allocated defer record might point
 			// to a heap-allocated defer record. Keep that heap record live.
-			scanblock(uintptr(unsafe.Pointer(&d.link)), sys.PtrSize, &oneptrmask[0], gcw, &state)
+			scanblock(uintptr(unsafe.Pointer(&d.link)), goarch.PtrSize, &oneptrmask[0], gcw, &state)
 		}
 		// Retain defers records themselves.
 		// Defer records might not be reachable from the G through regular heap
 		// tracing because the defer linked list might weave between the stack and the heap.
 		if d.heap {
-			scanblock(uintptr(unsafe.Pointer(&d)), sys.PtrSize, &oneptrmask[0], gcw, &state)
+			scanblock(uintptr(unsafe.Pointer(&d)), goarch.PtrSize, &oneptrmask[0], gcw, &state)
 		}
 	}
 	if gp._panic != nil {
@@ -913,13 +910,13 @@ func scanframeworker(frame *stkframe, state *stackScanState, gcw *gcWork) {
 
 	// Scan local variables if stack frame has been allocated.
 	if locals.n > 0 {
-		size := uintptr(locals.n) * sys.PtrSize
+		size := uintptr(locals.n) * goarch.PtrSize
 		scanblock(frame.varp-size, size, locals.bytedata, gcw, state)
 	}
 
 	// Scan arguments.
 	if args.n > 0 {
-		scanblock(frame.argp, uintptr(args.n)*sys.PtrSize, args.bytedata, gcw, state)
+		scanblock(frame.argp, uintptr(args.n)*goarch.PtrSize, args.bytedata, gcw, state)
 	}
 
 	// Add all stack objects to the stack object list.
@@ -1172,9 +1169,9 @@ func scanblock(b0, n0 uintptr, ptrmask *uint8, gcw *gcWork, stk *stackScanState)
 
 	for i := uintptr(0); i < n; {
 		// Find bits for the next word.
-		bits := uint32(*addb(ptrmask, i/(sys.PtrSize*8)))
+		bits := uint32(*addb(ptrmask, i/(goarch.PtrSize*8)))
 		if bits == 0 {
-			i += sys.PtrSize * 8
+			i += goarch.PtrSize * 8
 			continue
 		}
 		for j := 0; j < 8 && i < n; j++ {
@@ -1190,7 +1187,7 @@ func scanblock(b0, n0 uintptr, ptrmask *uint8, gcw *gcWork, stk *stackScanState)
 				}
 			}
 			bits >>= 1
-			i += sys.PtrSize
+			i += goarch.PtrSize
 		}
 	}
 }
@@ -1251,7 +1248,7 @@ func scanobject(b uintptr, gcw *gcWork) {
 	}
 
 	var i uintptr
-	for i = 0; i < n; i, hbits = i+sys.PtrSize, hbits.next() {
+	for i = 0; i < n; i, hbits = i+goarch.PtrSize, hbits.next() {
 		// Load bits once. See CL 22712 and issue 16973 for discussion.
 		bits := hbits.bits()
 		if bits&bitScan == 0 {
@@ -1300,7 +1297,7 @@ func scanConservative(b, n uintptr, ptrmask *uint8, gcw *gcWork, state *stackSca
 		print("conservatively scanning [", hex(b), ",", hex(b+n), ")\n")
 		hexdumpWords(b, b+n, func(p uintptr) byte {
 			if ptrmask != nil {
-				word := (p - b) / sys.PtrSize
+				word := (p - b) / goarch.PtrSize
 				bits := *addb(ptrmask, word/8)
 				if (bits>>(word%8))&1 == 0 {
 					return '$'
@@ -1325,9 +1322,9 @@ func scanConservative(b, n uintptr, ptrmask *uint8, gcw *gcWork, state *stackSca
 		printunlock()
 	}
 
-	for i := uintptr(0); i < n; i += sys.PtrSize {
+	for i := uintptr(0); i < n; i += goarch.PtrSize {
 		if ptrmask != nil {
-			word := i / sys.PtrSize
+			word := i / goarch.PtrSize
 			bits := *addb(ptrmask, word/8)
 			if bits == 0 {
 				// Skip 8 words (the loop increment will do the 8th)
@@ -1336,10 +1333,10 @@ func scanConservative(b, n uintptr, ptrmask *uint8, gcw *gcWork, state *stackSca
 				// seen this word of ptrmask, so i
 				// must be 8-word-aligned, but check
 				// our reasoning just in case.
-				if i%(sys.PtrSize*8) != 0 {
+				if i%(goarch.PtrSize*8) != 0 {
 					throw("misaligned mask")
 				}
-				i += sys.PtrSize*8 - sys.PtrSize
+				i += goarch.PtrSize*8 - goarch.PtrSize
 				continue
 			}
 			if (bits>>(word%8))&1 == 0 {
@@ -1401,7 +1398,7 @@ func shade(b uintptr) {
 //go:nowritebarrierrec
 func greyobject(obj, base, off uintptr, span *mspan, gcw *gcWork, objIndex uintptr) {
 	// obj should be start of allocation, and so must be at least pointer-aligned.
-	if obj&(sys.PtrSize-1) != 0 {
+	if obj&(goarch.PtrSize-1) != 0 {
 		throw("greyobject: obj not pointer-aligned")
 	}
 	mbits := span.markBitsForIndex(objIndex)
@@ -1473,13 +1470,13 @@ func gcDumpObject(label string, obj, off uintptr) {
 		// We're printing something from a stack frame. We
 		// don't know how big it is, so just show up to an
 		// including off.
-		size = off + sys.PtrSize
+		size = off + goarch.PtrSize
 	}
-	for i := uintptr(0); i < size; i += sys.PtrSize {
+	for i := uintptr(0); i < size; i += goarch.PtrSize {
 		// For big objects, just print the beginning (because
 		// that usually hints at the object's type) and the
 		// fields around off.
-		if !(i < 128*sys.PtrSize || off-16*sys.PtrSize < i && i < off+16*sys.PtrSize) {
+		if !(i < 128*goarch.PtrSize || off-16*goarch.PtrSize < i && i < off+16*goarch.PtrSize) {
 			skipped = true
 			continue
 		}
diff --git a/src/runtime/mgcscavenge.go b/src/runtime/mgcscavenge.go
index 7578129f9d1..2bb19985db0 100644
--- a/src/runtime/mgcscavenge.go
+++ b/src/runtime/mgcscavenge.go
@@ -56,6 +56,7 @@
 package runtime
 
 import (
+	"internal/goos"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -90,7 +91,7 @@ const (
 	//
 	// This ratio is used as part of multiplicative factor to help the scavenger account
 	// for the additional costs of using scavenged memory in its pacing.
-	scavengeCostRatio = 0.7 * (sys.GoosDarwin + sys.GoosIos)
+	scavengeCostRatio = 0.7 * (goos.IsDarwin + goos.IsIos)
 
 	// scavengeReservationShards determines the amount of memory the scavenger
 	// should reserve for scavenging at a time. Specifically, the amount of
@@ -249,7 +250,7 @@ func scavengeSleep(ns int64) int64 {
 // The background scavenger maintains the RSS of the application below
 // the line described by the proportional scavenging statistics in
 // the mheap struct.
-func bgscavenge() {
+func bgscavenge(c chan int) {
 	scavenge.g = getg()
 
 	lockInit(&scavenge.lock, lockRankScavenge)
@@ -261,7 +262,7 @@ func bgscavenge() {
 		wakeScavenger()
 	}
 
-	gcenable_setup <- 1
+	c <- 1
 	goparkunlock(&scavenge.lock, waitReasonGCScavengeWait, traceEvGoBlock, 1)
 
 	// Exponentially-weighted moving average of the fraction of time this
diff --git a/src/runtime/mgcstack.go b/src/runtime/mgcstack.go
index 92d58485f6f..49dc54e1652 100644
--- a/src/runtime/mgcstack.go
+++ b/src/runtime/mgcstack.go
@@ -95,7 +95,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -107,7 +107,7 @@ const stackTraceDebug = false
 //go:notinheap
 type stackWorkBuf struct {
 	stackWorkBufHdr
-	obj [(_WorkbufSize - unsafe.Sizeof(stackWorkBufHdr{})) / sys.PtrSize]uintptr
+	obj [(_WorkbufSize - unsafe.Sizeof(stackWorkBufHdr{})) / goarch.PtrSize]uintptr
 }
 
 // Header declaration must come after the buf declaration above, because of issue #14620.
diff --git a/src/runtime/mgcsweep.go b/src/runtime/mgcsweep.go
index 8fe3a653407..1812644623b 100644
--- a/src/runtime/mgcsweep.go
+++ b/src/runtime/mgcsweep.go
@@ -153,13 +153,13 @@ func finishsweep_m() {
 	nextMarkBitArenaEpoch()
 }
 
-func bgsweep() {
+func bgsweep(c chan int) {
 	sweep.g = getg()
 
 	lockInit(&sweep.lock, lockRankSweep)
 	lock(&sweep.lock)
 	sweep.parked = true
-	gcenable_setup <- 1
+	c <- 1
 	goparkunlock(&sweep.lock, waitReasonGCSweepWait, traceEvGoBlock, 1)
 
 	for {
diff --git a/src/runtime/mgcwork.go b/src/runtime/mgcwork.go
index 667c7afa971..8787d93d873 100644
--- a/src/runtime/mgcwork.go
+++ b/src/runtime/mgcwork.go
@@ -5,8 +5,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -322,7 +322,7 @@ type workbufhdr struct {
 type workbuf struct {
 	workbufhdr
 	// account for the above fields
-	obj [(_WorkbufSize - unsafe.Sizeof(workbufhdr{})) / sys.PtrSize]uintptr
+	obj [(_WorkbufSize - unsafe.Sizeof(workbufhdr{})) / goarch.PtrSize]uintptr
 }
 
 // workbuf factory routines. These funcs are used to manage the
diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index 84c00ce8f85..b78f752ded6 100644
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -10,8 +10,8 @@ package runtime
 
 import (
 	"internal/cpu"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -497,13 +497,13 @@ func recordspan(vh unsafe.Pointer, p unsafe.Pointer) {
 	assertLockHeld(&h.lock)
 
 	if len(h.allspans) >= cap(h.allspans) {
-		n := 64 * 1024 / sys.PtrSize
+		n := 64 * 1024 / goarch.PtrSize
 		if n < cap(h.allspans)*3/2 {
 			n = cap(h.allspans) * 3 / 2
 		}
 		var new []*mspan
 		sp := (*slice)(unsafe.Pointer(&new))
-		sp.array = sysAlloc(uintptr(n)*sys.PtrSize, &memstats.other_sys)
+		sp.array = sysAlloc(uintptr(n)*goarch.PtrSize, &memstats.other_sys)
 		if sp.array == nil {
 			throw("runtime: cannot allocate memory")
 		}
@@ -1822,7 +1822,7 @@ func addfinalizer(p unsafe.Pointer, f *funcval, nret uintptr, fint *_type, ot *p
 			scanobject(base, gcw)
 			// Mark the finalizer itself, since the
 			// special isn't part of the GC'd heap.
-			scanblock(uintptr(unsafe.Pointer(&s.fn)), sys.PtrSize, &oneptrmask[0], gcw, nil)
+			scanblock(uintptr(unsafe.Pointer(&s.fn)), goarch.PtrSize, &oneptrmask[0], gcw, nil)
 			releasem(mp)
 		}
 		return true
diff --git a/src/runtime/mkduff.go b/src/runtime/mkduff.go
index 8632fe08a3d..f0367450923 100644
--- a/src/runtime/mkduff.go
+++ b/src/runtime/mkduff.go
@@ -154,7 +154,7 @@ func zeroARM64(w io.Writer) {
 	// ZR: always zero
 	// R20: ptr to memory to be zeroed
 	// On return, R20 points to the last zeroed dword.
-	fmt.Fprintln(w, "TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0")
+	fmt.Fprintln(w, "TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0")
 	for i := 0; i < 63; i++ {
 		fmt.Fprintln(w, "\tSTP.P\t(ZR, ZR), 16(R20)")
 	}
@@ -167,7 +167,7 @@ func copyARM64(w io.Writer) {
 	// R21: ptr to destination memory
 	// R26, R27 (aka REGTMP): scratch space
 	// R20 and R21 are updated as a side effect
-	fmt.Fprintln(w, "TEXT runtime·duffcopy(SB), NOSPLIT|NOFRAME, $0-0")
+	fmt.Fprintln(w, "TEXT runtime·duffcopy(SB), NOSPLIT|NOFRAME, $0-0")
 
 	for i := 0; i < 64; i++ {
 		fmt.Fprintln(w, "\tLDP.P\t16(R20), (R26, R27)")
@@ -179,6 +179,7 @@ func copyARM64(w io.Writer) {
 
 func tagsPPC64x(w io.Writer) {
 	fmt.Fprintln(w)
+	fmt.Fprintln(w, "//go:build ppc64 || ppc64le")
 	fmt.Fprintln(w, "// +build ppc64 ppc64le")
 	fmt.Fprintln(w)
 }
@@ -202,6 +203,7 @@ func copyPPC64x(w io.Writer) {
 
 func tagsMIPS64x(w io.Writer) {
 	fmt.Fprintln(w)
+	fmt.Fprintln(w, "//go:build mips64 || mips64le")
 	fmt.Fprintln(w, "// +build mips64 mips64le")
 	fmt.Fprintln(w)
 }
diff --git a/src/runtime/mkpreempt.go b/src/runtime/mkpreempt.go
index 3a9e6cc4780..f2b90307cab 100644
--- a/src/runtime/mkpreempt.go
+++ b/src/runtime/mkpreempt.go
@@ -123,12 +123,12 @@ func header(arch string) {
 	fmt.Fprintf(out, "// Code generated by mkpreempt.go; DO NOT EDIT.\n\n")
 	if beLe[arch] {
 		base := arch[:len(arch)-1]
+		fmt.Fprintf(out, "//go:build %s || %sle\n", base, base)
 		fmt.Fprintf(out, "// +build %s %sle\n\n", base, base)
 	}
 	fmt.Fprintf(out, "#include \"go_asm.h\"\n")
 	fmt.Fprintf(out, "#include \"textflag.h\"\n\n")
-	fmt.Fprintf(out, "// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.\n")
-	fmt.Fprintf(out, "TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0\n")
+	fmt.Fprintf(out, "TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0\n")
 }
 
 func p(f string, args ...interface{}) {
diff --git a/src/runtime/mprof.go b/src/runtime/mprof.go
index 5235b898e4f..0ba415ba5ac 100644
--- a/src/runtime/mprof.go
+++ b/src/runtime/mprof.go
@@ -8,6 +8,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"unsafe"
 )
@@ -621,7 +622,7 @@ func record(r *MemProfileRecord, b *bucket) {
 	r.AllocObjects = int64(mp.active.allocs)
 	r.FreeObjects = int64(mp.active.frees)
 	if raceenabled {
-		racewriterangepc(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0), getcallerpc(), funcPC(MemProfile))
+		racewriterangepc(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0), getcallerpc(), abi.FuncPCABIInternal(MemProfile))
 	}
 	if msanenabled {
 		msanwrite(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0))
@@ -674,7 +675,7 @@ func BlockProfile(p []BlockProfileRecord) (n int, ok bool) {
 			}
 			r.Cycles = bp.cycles
 			if raceenabled {
-				racewriterangepc(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0), getcallerpc(), funcPC(BlockProfile))
+				racewriterangepc(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0), getcallerpc(), abi.FuncPCABIInternal(BlockProfile))
 			}
 			if msanenabled {
 				msanwrite(unsafe.Pointer(&r.Stack0[0]), unsafe.Sizeof(r.Stack0))
diff --git a/src/runtime/mranges.go b/src/runtime/mranges.go
index 84a2c06dbb2..e0be1e134ed 100644
--- a/src/runtime/mranges.go
+++ b/src/runtime/mranges.go
@@ -10,7 +10,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -167,7 +167,7 @@ func (a *addrRanges) init(sysStat *sysMemStat) {
 	ranges := (*notInHeapSlice)(unsafe.Pointer(&a.ranges))
 	ranges.len = 0
 	ranges.cap = 16
-	ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), sys.PtrSize, sysStat))
+	ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), goarch.PtrSize, sysStat))
 	a.sysStat = sysStat
 	a.totalBytes = 0
 }
@@ -294,7 +294,7 @@ func (a *addrRanges) add(r addrRange) {
 			ranges := (*notInHeapSlice)(unsafe.Pointer(&a.ranges))
 			ranges.len = len(oldRanges) + 1
 			ranges.cap = cap(oldRanges) * 2
-			ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), sys.PtrSize, a.sysStat))
+			ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), goarch.PtrSize, a.sysStat))
 
 			// Copy in the old array, but make space for the new range.
 			copy(a.ranges[:i], oldRanges[:i])
@@ -364,7 +364,7 @@ func (a *addrRanges) cloneInto(b *addrRanges) {
 		ranges := (*notInHeapSlice)(unsafe.Pointer(&b.ranges))
 		ranges.len = 0
 		ranges.cap = cap(a.ranges)
-		ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), sys.PtrSize, b.sysStat))
+		ranges.array = (*notInHeap)(persistentalloc(unsafe.Sizeof(addrRange{})*uintptr(ranges.cap), goarch.PtrSize, b.sysStat))
 	}
 	b.ranges = b.ranges[:len(a.ranges)]
 	b.totalBytes = a.totalBytes
diff --git a/src/runtime/msan/msan.go b/src/runtime/msan/msan.go
index c81577dddac..9908a8ec221 100644
--- a/src/runtime/msan/msan.go
+++ b/src/runtime/msan/msan.go
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build msan,linux
+//go:build msan && linux && (amd64 || arm64)
+// +build msan
+// +build linux
 // +build amd64 arm64
 
 package msan
diff --git a/src/runtime/msan_amd64.s b/src/runtime/msan_amd64.s
index 669e9ca73f8..1bb57a3b7e8 100644
--- a/src/runtime/msan_amd64.s
+++ b/src/runtime/msan_amd64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build msan
 // +build msan
 
 #include "go_asm.h"
diff --git a/src/runtime/msan_arm64.s b/src/runtime/msan_arm64.s
index f19906cfc83..93ade8dd897 100644
--- a/src/runtime/msan_arm64.s
+++ b/src/runtime/msan_arm64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build msan
 // +build msan
 
 #include "go_asm.h"
diff --git a/src/runtime/mspanset.go b/src/runtime/mspanset.go
index 10d2596c38c..29f14910ccd 100644
--- a/src/runtime/mspanset.go
+++ b/src/runtime/mspanset.go
@@ -6,8 +6,8 @@ package runtime
 
 import (
 	"internal/cpu"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -82,7 +82,7 @@ func (b *spanSet) push(s *mspan) {
 retry:
 	if top < spineLen {
 		spine := atomic.Loadp(unsafe.Pointer(&b.spine))
-		blockp := add(spine, sys.PtrSize*top)
+		blockp := add(spine, goarch.PtrSize*top)
 		block = (*spanSetBlock)(atomic.Loadp(blockp))
 	} else {
 		// Add a new block to the spine, potentially growing
@@ -102,11 +102,11 @@ retry:
 			if newCap == 0 {
 				newCap = spanSetInitSpineCap
 			}
-			newSpine := persistentalloc(newCap*sys.PtrSize, cpu.CacheLineSize, &memstats.gcMiscSys)
+			newSpine := persistentalloc(newCap*goarch.PtrSize, cpu.CacheLineSize, &memstats.gcMiscSys)
 			if b.spineCap != 0 {
 				// Blocks are allocated off-heap, so
 				// no write barriers.
-				memmove(newSpine, b.spine, b.spineCap*sys.PtrSize)
+				memmove(newSpine, b.spine, b.spineCap*goarch.PtrSize)
 			}
 			// Spine is allocated off-heap, so no write barrier.
 			atomic.StorepNoWB(unsafe.Pointer(&b.spine), newSpine)
@@ -124,7 +124,7 @@ retry:
 		block = spanSetBlockPool.alloc()
 
 		// Add it to the spine.
-		blockp := add(b.spine, sys.PtrSize*top)
+		blockp := add(b.spine, goarch.PtrSize*top)
 		// Blocks are allocated off-heap, so no write barrier.
 		atomic.StorepNoWB(blockp, unsafe.Pointer(block))
 		atomic.Storeuintptr(&b.spineLen, spineLen+1)
@@ -181,7 +181,7 @@ claimLoop:
 	// grows monotonically and we've already verified it, we'll definitely
 	// be reading from a valid block.
 	spine := atomic.Loadp(unsafe.Pointer(&b.spine))
-	blockp := add(spine, sys.PtrSize*uintptr(top))
+	blockp := add(spine, goarch.PtrSize*uintptr(top))
 
 	// Given that the spine length is correct, we know we will never
 	// see a nil block here, since the length is always updated after
@@ -241,7 +241,7 @@ func (b *spanSet) reset() {
 		// since it may be pushed into again. In order to avoid leaking
 		// memory since we're going to reset the head and tail, clean
 		// up such a block now, if it exists.
-		blockp := (**spanSetBlock)(add(b.spine, sys.PtrSize*uintptr(top)))
+		blockp := (**spanSetBlock)(add(b.spine, goarch.PtrSize*uintptr(top)))
 		block := *blockp
 		if block != nil {
 			// Sanity check the popped value.
diff --git a/src/runtime/mstats.go b/src/runtime/mstats.go
index eeb2a7b4bc7..341ba9a9365 100644
--- a/src/runtime/mstats.go
+++ b/src/runtime/mstats.go
@@ -7,8 +7,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -713,7 +713,7 @@ type heapStatsDelta struct {
 
 	// Add a uint32 to ensure this struct is a multiple of 8 bytes in size.
 	// Only necessary on 32-bit platforms.
-	_ [(sys.PtrSize / 4) % 2]uint32
+	_ [(goarch.PtrSize / 4) % 2]uint32
 }
 
 // merge adds in the deltas from b into a.
diff --git a/src/runtime/mwbbuf.go b/src/runtime/mwbbuf.go
index 6efc00007d5..78d9382620b 100644
--- a/src/runtime/mwbbuf.go
+++ b/src/runtime/mwbbuf.go
@@ -23,8 +23,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -145,7 +145,7 @@ func (b *wbBuf) putFast(old, new uintptr) bool {
 	p := (*[2]uintptr)(unsafe.Pointer(b.next))
 	p[0] = old
 	p[1] = new
-	b.next += 2 * sys.PtrSize
+	b.next += 2 * goarch.PtrSize
 	return b.next != b.end
 }
 
diff --git a/src/runtime/norace_linux_test.go b/src/runtime/norace_linux_test.go
index 94b7c7a4677..b199aa633c1 100644
--- a/src/runtime/norace_linux_test.go
+++ b/src/runtime/norace_linux_test.go
@@ -9,6 +9,7 @@
 package runtime_test
 
 import (
+	"internal/abi"
 	"runtime"
 	"testing"
 	"time"
@@ -25,7 +26,7 @@ func newOSProcCreated() {
 // Can't be run with -race because it inserts calls into newOSProcCreated()
 // that require a valid G/M.
 func TestNewOSProc0(t *testing.T) {
-	runtime.NewOSProc0(0x800000, unsafe.Pointer(runtime.FuncPC(newOSProcCreated)))
+	runtime.NewOSProc0(0x800000, unsafe.Pointer(abi.FuncPCABIInternal(newOSProcCreated)))
 	check := time.NewTicker(100 * time.Millisecond)
 	defer check.Stop()
 	end := time.After(5 * time.Second)
diff --git a/src/runtime/os3_plan9.go b/src/runtime/os3_plan9.go
index c5dc23de8b6..a06d74e279f 100644
--- a/src/runtime/os3_plan9.go
+++ b/src/runtime/os3_plan9.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -92,15 +93,15 @@ func sighandler(_ureg *ureg, note *byte, gp *g) int {
 			if usesLR {
 				c.setlr(pc)
 			} else {
-				sp -= sys.PtrSize
+				sp -= goarch.PtrSize
 				*(*uintptr)(unsafe.Pointer(sp)) = pc
 				c.setsp(sp)
 			}
 		}
 		if usesLR {
-			c.setpc(funcPC(sigpanictramp))
+			c.setpc(abi.FuncPCABI0(sigpanictramp))
 		} else {
-			c.setpc(funcPC(sigpanic0))
+			c.setpc(abi.FuncPCABI0(sigpanic0))
 		}
 		return _NCONT
 	}
diff --git a/src/runtime/os3_solaris.go b/src/runtime/os3_solaris.go
index 39ef831acfe..84194a3050d 100644
--- a/src/runtime/os3_solaris.go
+++ b/src/runtime/os3_solaris.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -172,7 +173,7 @@ func newosproc(mp *m) {
 	// Disable signals during create, so that the new thread starts
 	// with signals disabled. It will enable them in minit.
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
-	ret = pthread_create(&tid, &attr, funcPC(tstart_sysvicall), unsafe.Pointer(mp))
+	ret = pthread_create(&tid, &attr, abi.FuncPCABI0(tstart_sysvicall), unsafe.Pointer(mp))
 	sigprocmask(_SIG_SETMASK, &oset, nil)
 	if ret != 0 {
 		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", ret, ")\n")
@@ -215,7 +216,7 @@ func miniterrno()
 // Called to initialize a new m (including the bootstrap m).
 // Called on the new thread, cannot allocate memory.
 func minit() {
-	asmcgocall(unsafe.Pointer(funcPC(miniterrno)), unsafe.Pointer(&libc____errno))
+	asmcgocall(unsafe.Pointer(abi.FuncPCABI0(miniterrno)), unsafe.Pointer(&libc____errno))
 
 	minitSignals()
 
@@ -241,8 +242,8 @@ func setsig(i uint32, fn uintptr) {
 
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
-		fn = funcPC(sigtramp)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
 	}
 	*((*uintptr)(unsafe.Pointer(&sa._funcptr))) = fn
 	sigaction(i, &sa, nil)
@@ -390,6 +391,7 @@ func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (un
 }
 
 //go:nosplit
+//go:cgo_unsafe_args
 func doMmap(addr, n, prot, flags, fd, off uintptr) (uintptr, uintptr) {
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(&libc_mmap))
@@ -598,7 +600,7 @@ func sysargs(argc int32, argv **byte) {
 	n++
 
 	// now argv+n is auxv
-	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
 	sysauxv(auxv[:])
 }
 
diff --git a/src/runtime/os_aix.go b/src/runtime/os_aix.go
index 4fb1c8e845c..478dde2fc3f 100644
--- a/src/runtime/os_aix.go
+++ b/src/runtime/os_aix.go
@@ -8,6 +8,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"unsafe"
 )
 
@@ -267,7 +268,7 @@ func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
 		fn = uintptr(unsafe.Pointer(&sigtramp))
 	}
 	sa.sa_handler = fn
diff --git a/src/runtime/os_darwin.go b/src/runtime/os_darwin.go
index 00139351abc..ca61f20e8ac 100644
--- a/src/runtime/os_darwin.go
+++ b/src/runtime/os_darwin.go
@@ -118,10 +118,15 @@ func sigNoteWakeup(*note) {
 
 // sigNoteSleep waits for a note created by sigNoteSetup to be woken.
 func sigNoteSleep(*note) {
-	entersyscallblock()
-	var b byte
-	read(sigNoteRead, unsafe.Pointer(&b), 1)
-	exitsyscall()
+	for {
+		var b byte
+		entersyscallblock()
+		n := read(sigNoteRead, unsafe.Pointer(&b), 1)
+		exitsyscall()
+		if n != -_EINTR {
+			return
+		}
+	}
 }
 
 // BSD interface for threading.
@@ -364,7 +369,7 @@ func setsig(i uint32, fn uintptr) {
 	var sa usigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = ^uint32(0)
-	if fn == funcPC(sighandler) { // funcPC(sighandler) matches the callers in signal_unix.go
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
 		if iscgo {
 			fn = abi.FuncPCABI0(cgoSigtramp)
 		} else {
diff --git a/src/runtime/os_dragonfly.go b/src/runtime/os_dragonfly.go
index 5c688a31096..191a560667c 100644
--- a/src/runtime/os_dragonfly.go
+++ b/src/runtime/os_dragonfly.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -147,14 +148,14 @@ func lwp_start(uintptr)
 func newosproc(mp *m) {
 	stk := unsafe.Pointer(mp.g0.stack.hi)
 	if false {
-		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " lwp_start=", funcPC(lwp_start), " id=", mp.id, " ostk=", &mp, "\n")
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " lwp_start=", abi.FuncPCABI0(lwp_start), " id=", mp.id, " ostk=", &mp, "\n")
 	}
 
 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
 
 	params := lwpparams{
-		start_func: funcPC(lwp_start),
+		start_func: abi.FuncPCABI0(lwp_start),
 		arg:        unsafe.Pointer(mp),
 		stack:      uintptr(stk),
 		tid1:       nil, // minit will record tid
@@ -226,8 +227,8 @@ func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
-		fn = funcPC(sigtramp)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
 	}
 	sa.sa_sigaction = fn
 	sigaction(i, &sa, nil)
@@ -278,7 +279,7 @@ func sysargs(argc int32, argv **byte) {
 	// skip NULL separator
 	n++
 
-	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
 	sysauxv(auxv[:])
 }
 
diff --git a/src/runtime/os_freebsd.go b/src/runtime/os_freebsd.go
index 09dd50ce594..5a8121a420f 100644
--- a/src/runtime/os_freebsd.go
+++ b/src/runtime/os_freebsd.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -116,8 +117,8 @@ func getncpu() int32 {
 	}
 
 	maskSize := int(maxcpus+7) / 8
-	if maskSize < sys.PtrSize {
-		maskSize = sys.PtrSize
+	if maskSize < goarch.PtrSize {
+		maskSize = goarch.PtrSize
 	}
 	if maskSize > len(mask) {
 		maskSize = len(mask)
@@ -197,11 +198,11 @@ func thr_start()
 func newosproc(mp *m) {
 	stk := unsafe.Pointer(mp.g0.stack.hi)
 	if false {
-		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " thr_start=", funcPC(thr_start), " id=", mp.id, " ostk=", &mp, "\n")
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " thr_start=", abi.FuncPCABI0(thr_start), " id=", mp.id, " ostk=", &mp, "\n")
 	}
 
 	param := thrparam{
-		start_func: funcPC(thr_start),
+		start_func: abi.FuncPCABI0(thr_start),
 		arg:        unsafe.Pointer(mp),
 		stack_base: mp.g0.stack.lo,
 		stack_size: uintptr(stk) - mp.g0.stack.lo,
@@ -236,7 +237,7 @@ func newosproc0(stacksize uintptr, fn unsafe.Pointer) {
 	// However, newosproc0 is currently unreachable because builds
 	// utilizing c-shared/c-archive force external linking.
 	param := thrparam{
-		start_func: funcPC(fn),
+		start_func: uintptr(fn),
 		arg:        nil,
 		stack_base: uintptr(stack), //+stacksize?
 		stack_size: stacksize,
@@ -391,7 +392,7 @@ func sysargs(argc int32, argv **byte) {
 	n++
 
 	// now argv+n is auxv
-	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
 	sysauxv(auxv[:])
 }
 
diff --git a/src/runtime/os_freebsd2.go b/src/runtime/os_freebsd2.go
index fde6fbf1b14..7e266dc27e2 100644
--- a/src/runtime/os_freebsd2.go
+++ b/src/runtime/os_freebsd2.go
@@ -7,14 +7,16 @@
 
 package runtime
 
+import "internal/abi"
+
 //go:nosplit
 //go:nowritebarrierrec
 func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
-		fn = funcPC(sigtramp)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
 	}
 	sa.sa_handler = fn
 	sigaction(i, &sa, nil)
diff --git a/src/runtime/os_freebsd_amd64.go b/src/runtime/os_freebsd_amd64.go
index dc0bb9ff96f..b179383eacc 100644
--- a/src/runtime/os_freebsd_amd64.go
+++ b/src/runtime/os_freebsd_amd64.go
@@ -4,6 +4,8 @@
 
 package runtime
 
+import "internal/abi"
+
 func cgoSigtramp()
 
 //go:nosplit
@@ -12,11 +14,11 @@ func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
 		if iscgo {
-			fn = funcPC(cgoSigtramp)
+			fn = abi.FuncPCABI0(cgoSigtramp)
 		} else {
-			fn = funcPC(sigtramp)
+			fn = abi.FuncPCABI0(sigtramp)
 		}
 	}
 	sa.sa_handler = fn
diff --git a/src/runtime/os_linux.go b/src/runtime/os_linux.go
index c8b29e396c7..88c16f71639 100644
--- a/src/runtime/os_linux.go
+++ b/src/runtime/os_linux.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -142,14 +143,14 @@ func newosproc(mp *m) {
 	 * note: strace gets confused if we use CLONE_PTRACE here.
 	 */
 	if false {
-		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " clone=", funcPC(clone), " id=", mp.id, " ostk=", &mp, "\n")
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " clone=", abi.FuncPCABI0(clone), " id=", mp.id, " ostk=", &mp, "\n")
 	}
 
 	// Disable signals during clone, so that the new thread starts
 	// with signals disabled. It will enable them in minit.
 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
-	ret := clone(cloneFlags, stk, unsafe.Pointer(mp), unsafe.Pointer(mp.g0), unsafe.Pointer(funcPC(mstart)))
+	ret := clone(cloneFlags, stk, unsafe.Pointer(mp), unsafe.Pointer(mp.g0), unsafe.Pointer(abi.FuncPCABI0(mstart)))
 	sigprocmask(_SIG_SETMASK, &oset, nil)
 
 	if ret < 0 {
@@ -205,7 +206,7 @@ func sysargs(argc int32, argv **byte) {
 	n++
 
 	// now argv+n is auxv
-	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
 	if sysauxv(auxv[:]) != 0 {
 		return
 	}
@@ -429,13 +430,13 @@ func setsig(i uint32, fn uintptr) {
 	// should not be used". x86_64 kernel requires it. Only use it on
 	// x86.
 	if GOARCH == "386" || GOARCH == "amd64" {
-		sa.sa_restorer = funcPC(sigreturn)
+		sa.sa_restorer = abi.FuncPCABI0(sigreturn)
 	}
-	if fn == funcPC(sighandler) {
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
 		if iscgo {
-			fn = funcPC(cgoSigtramp)
+			fn = abi.FuncPCABI0(cgoSigtramp)
 		} else {
-			fn = funcPC(sigtramp)
+			fn = abi.FuncPCABI0(sigtramp)
 		}
 	}
 	sa.sa_handler = fn
diff --git a/src/runtime/os_netbsd.go b/src/runtime/os_netbsd.go
index 6fbb3aa6947..2c20ee21734 100644
--- a/src/runtime/os_netbsd.go
+++ b/src/runtime/os_netbsd.go
@@ -5,8 +5,9 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -215,7 +216,7 @@ func newosproc(mp *m) {
 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
 
-	lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp.g0, funcPC(netbsdMstart))
+	lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp.g0, abi.FuncPCABI0(netbsdMstart))
 
 	ret := lwp_create(unsafe.Pointer(&uc), _LWP_DETACHED, unsafe.Pointer(&mp.procid))
 	sigprocmask(_SIG_SETMASK, &oset, nil)
@@ -318,8 +319,8 @@ func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = sigset_all
-	if fn == funcPC(sighandler) {
-		fn = funcPC(sigtramp)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
 	}
 	sa.sa_sigaction = fn
 	sigaction(i, &sa, nil)
@@ -371,7 +372,7 @@ func sysargs(argc int32, argv **byte) {
 	n++
 
 	// now argv+n is auxv
-	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
 	sysauxv(auxv[:])
 }
 
diff --git a/src/runtime/os_netbsd_386.go b/src/runtime/os_netbsd_386.go
index 037f7e36dc6..ac89b9852c7 100644
--- a/src/runtime/os_netbsd_386.go
+++ b/src/runtime/os_netbsd_386.go
@@ -4,11 +4,14 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
 	// Machine dependent mcontext initialisation for LWP.
-	mc.__gregs[_REG_EIP] = uint32(funcPC(lwp_tramp))
+	mc.__gregs[_REG_EIP] = uint32(abi.FuncPCABI0(lwp_tramp))
 	mc.__gregs[_REG_UESP] = uint32(uintptr(stk))
 	mc.__gregs[_REG_EBX] = uint32(uintptr(unsafe.Pointer(mp)))
 	mc.__gregs[_REG_EDX] = uint32(uintptr(unsafe.Pointer(gp)))
diff --git a/src/runtime/os_netbsd_amd64.go b/src/runtime/os_netbsd_amd64.go
index 5118b0c4ffd..74eea0ceabc 100644
--- a/src/runtime/os_netbsd_amd64.go
+++ b/src/runtime/os_netbsd_amd64.go
@@ -4,11 +4,14 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
 	// Machine dependent mcontext initialisation for LWP.
-	mc.__gregs[_REG_RIP] = uint64(funcPC(lwp_tramp))
+	mc.__gregs[_REG_RIP] = uint64(abi.FuncPCABI0(lwp_tramp))
 	mc.__gregs[_REG_RSP] = uint64(uintptr(stk))
 	mc.__gregs[_REG_R8] = uint64(uintptr(unsafe.Pointer(mp)))
 	mc.__gregs[_REG_R9] = uint64(uintptr(unsafe.Pointer(gp)))
diff --git a/src/runtime/os_netbsd_arm.go b/src/runtime/os_netbsd_arm.go
index b5ec23e45b0..5fb4e08d66a 100644
--- a/src/runtime/os_netbsd_arm.go
+++ b/src/runtime/os_netbsd_arm.go
@@ -4,11 +4,14 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
 	// Machine dependent mcontext initialisation for LWP.
-	mc.__gregs[_REG_R15] = uint32(funcPC(lwp_tramp))
+	mc.__gregs[_REG_R15] = uint32(abi.FuncPCABI0(lwp_tramp))
 	mc.__gregs[_REG_R13] = uint32(uintptr(stk))
 	mc.__gregs[_REG_R0] = uint32(uintptr(unsafe.Pointer(mp)))
 	mc.__gregs[_REG_R1] = uint32(uintptr(unsafe.Pointer(gp)))
diff --git a/src/runtime/os_netbsd_arm64.go b/src/runtime/os_netbsd_arm64.go
index 8d21b0a430f..2dda9c9274d 100644
--- a/src/runtime/os_netbsd_arm64.go
+++ b/src/runtime/os_netbsd_arm64.go
@@ -4,11 +4,14 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
 	// Machine dependent mcontext initialisation for LWP.
-	mc.__gregs[_REG_ELR] = uint64(funcPC(lwp_tramp))
+	mc.__gregs[_REG_ELR] = uint64(abi.FuncPCABI0(lwp_tramp))
 	mc.__gregs[_REG_X31] = uint64(uintptr(stk))
 	mc.__gregs[_REG_X0] = uint64(uintptr(unsafe.Pointer(mp)))
 	mc.__gregs[_REG_X1] = uint64(uintptr(unsafe.Pointer(mp.g0)))
diff --git a/src/runtime/os_openbsd.go b/src/runtime/os_openbsd.go
index 6259b96c22b..54f36c6ebff 100644
--- a/src/runtime/os_openbsd.go
+++ b/src/runtime/os_openbsd.go
@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"unsafe"
 )
@@ -191,8 +192,8 @@ func setsig(i uint32, fn uintptr) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
 	sa.sa_mask = uint32(sigset_all)
-	if fn == funcPC(sighandler) {
-		fn = funcPC(sigtramp)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		fn = abi.FuncPCABI0(sigtramp)
 	}
 	sa.sa_sigaction = fn
 	sigaction(i, &sa, nil)
diff --git a/src/runtime/os_openbsd_libc.go b/src/runtime/os_openbsd_libc.go
index cff5a092d7c..981e49827fb 100644
--- a/src/runtime/os_openbsd_libc.go
+++ b/src/runtime/os_openbsd_libc.go
@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package runtime
 
 import (
+	"internal/abi"
 	"unsafe"
 )
 
@@ -48,7 +49,7 @@ func newosproc(mp *m) {
 	// setup and then calls mstart.
 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
-	err := pthread_create(&attr, funcPC(mstart_stub), unsafe.Pointer(mp))
+	err := pthread_create(&attr, abi.FuncPCABI0(mstart_stub), unsafe.Pointer(mp))
 	sigprocmask(_SIG_SETMASK, &oset, nil)
 	if err != 0 {
 		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
diff --git a/src/runtime/os_openbsd_syscall.go b/src/runtime/os_openbsd_syscall.go
index 53154879618..1ddee1864e4 100644
--- a/src/runtime/os_openbsd_syscall.go
+++ b/src/runtime/os_openbsd_syscall.go
@@ -2,13 +2,14 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build openbsd && !386 && openbsd && !amd64 && openbsd && !arm64
-// +build openbsd,!386,openbsd,!amd64,openbsd,!arm64
+//go:build openbsd && mips64
+// +build openbsd,mips64
 
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -28,12 +29,12 @@ func newosproc(mp *m) {
 	param := tforkt{
 		tf_tcb:   unsafe.Pointer(&mp.tls[0]),
 		tf_tid:   nil, // minit will record tid
-		tf_stack: uintptr(stk) - sys.PtrSize,
+		tf_stack: uintptr(stk) - goarch.PtrSize,
 	}
 
 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
-	ret := tfork(¶m, unsafe.Sizeof(param), mp, mp.g0, funcPC(mstart))
+	ret := tfork(¶m, unsafe.Sizeof(param), mp, mp.g0, abi.FuncPCABI0(mstart))
 	sigprocmask(_SIG_SETMASK, &oset, nil)
 
 	if ret < 0 {
diff --git a/src/runtime/os_openbsd_syscall1.go b/src/runtime/os_openbsd_syscall1.go
index ecae67aa2fc..c20ee8300e3 100644
--- a/src/runtime/os_openbsd_syscall1.go
+++ b/src/runtime/os_openbsd_syscall1.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build openbsd && !386 && !amd64 && !arm64
-// +build openbsd,!386,!amd64,!arm64
+//go:build openbsd && mips64
+// +build openbsd,mips64
 
 package runtime
 
diff --git a/src/runtime/os_openbsd_syscall2.go b/src/runtime/os_openbsd_syscall2.go
index 6aa57a99da1..af1997131fe 100644
--- a/src/runtime/os_openbsd_syscall2.go
+++ b/src/runtime/os_openbsd_syscall2.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build openbsd && !386 && !amd64 && !arm64
-// +build openbsd,!386,!amd64,!arm64
+//go:build openbsd && mips64
+// +build openbsd,mips64
 
 package runtime
 
diff --git a/src/runtime/os_plan9.go b/src/runtime/os_plan9.go
index 4d428346f0e..975d460a7da 100644
--- a/src/runtime/os_plan9.go
+++ b/src/runtime/os_plan9.go
@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"unsafe"
 )
@@ -346,7 +347,7 @@ func getRandomData(r []byte) {
 
 func initsig(preinit bool) {
 	if !preinit {
-		notify(unsafe.Pointer(funcPC(sigtramp)))
+		notify(unsafe.Pointer(abi.FuncPCABI0(sigtramp)))
 	}
 }
 
diff --git a/src/runtime/os_solaris.go b/src/runtime/os_solaris.go
index 89129e5f1ac..8ac1b08f690 100644
--- a/src/runtime/os_solaris.go
+++ b/src/runtime/os_solaris.go
@@ -179,6 +179,7 @@ func sysvicall3Err(fn *libcFunc, a1, a2, a3 uintptr) (r1, err uintptr) {
 }
 
 //go:nosplit
+//go:cgo_unsafe_args
 func sysvicall4(fn *libcFunc, a1, a2, a3, a4 uintptr) uintptr {
 	// Leave caller's PC/SP around for traceback.
 	gp := getg()
@@ -208,6 +209,7 @@ func sysvicall4(fn *libcFunc, a1, a2, a3, a4 uintptr) uintptr {
 }
 
 //go:nosplit
+//go:cgo_unsafe_args
 func sysvicall5(fn *libcFunc, a1, a2, a3, a4, a5 uintptr) uintptr {
 	// Leave caller's PC/SP around for traceback.
 	gp := getg()
@@ -237,6 +239,7 @@ func sysvicall5(fn *libcFunc, a1, a2, a3, a4, a5 uintptr) uintptr {
 }
 
 //go:nosplit
+//go:cgo_unsafe_args
 func sysvicall6(fn *libcFunc, a1, a2, a3, a4, a5, a6 uintptr) uintptr {
 	// Leave caller's PC/SP around for traceback.
 	gp := getg()
diff --git a/src/runtime/os_windows.go b/src/runtime/os_windows.go
index f0935264ac6..648239fb366 100644
--- a/src/runtime/os_windows.go
+++ b/src/runtime/os_windows.go
@@ -5,8 +5,9 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -543,7 +544,7 @@ func initLongPathSupport() {
 }
 
 func osinit() {
-	asmstdcallAddr = unsafe.Pointer(funcPC(asmstdcall))
+	asmstdcallAddr = unsafe.Pointer(abi.FuncPCABI0(asmstdcall))
 
 	setBadSignalMsg()
 
@@ -906,7 +907,7 @@ func semacreate(mp *m) {
 func newosproc(mp *m) {
 	// We pass 0 for the stack size to use the default for this binary.
 	thandle := stdcall6(_CreateThread, 0, 0,
-		funcPC(tstart_stdcall), uintptr(unsafe.Pointer(mp)),
+		abi.FuncPCABI0(tstart_stdcall), uintptr(unsafe.Pointer(mp)),
 		0, 0)
 
 	if thandle == 0 {
@@ -1385,14 +1386,14 @@ func preemptM(mp *m) {
 	if gp != nil && wantAsyncPreempt(gp) {
 		if ok, newpc := isAsyncSafePoint(gp, c.ip(), c.sp(), c.lr()); ok {
 			// Inject call to asyncPreempt
-			targetPC := funcPC(asyncPreempt)
+			targetPC := abi.FuncPCABI0(asyncPreempt)
 			switch GOARCH {
 			default:
 				throw("unsupported architecture")
 			case "386", "amd64":
 				// Make it look like the thread called targetPC.
 				sp := c.sp()
-				sp -= sys.PtrSize
+				sp -= goarch.PtrSize
 				*(*uintptr)(unsafe.Pointer(sp)) = newpc
 				c.set_sp(sp)
 				c.set_ip(targetPC)
diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index f6c38aafcc8..e4bdceb32f1 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -5,8 +5,7 @@
 package runtime
 
 import (
-	"internal/abi"
-	"internal/goexperiment"
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -31,7 +30,7 @@ import (
 // pc should be the program counter of the compiler-generated code that
 // triggered this panic.
 func panicCheck1(pc uintptr, msg string) {
-	if sys.GoarchWasm == 0 && hasPrefix(funcname(findfunc(pc)), "runtime.") {
+	if goarch.IsWasm == 0 && hasPrefix(funcname(findfunc(pc)), "runtime.") {
 		// Note: wasm can't tail call, so we can't get the original caller's pc.
 		throw(msg)
 	}
@@ -226,47 +225,27 @@ func panicmemAddr(addr uintptr) {
 	panic(errorAddressString{msg: "invalid memory address or nil pointer dereference", addr: addr})
 }
 
-// Create a new deferred function fn with siz bytes of arguments.
+// Create a new deferred function fn, which has no arguments and results.
 // The compiler turns a defer statement into a call to this.
-//go:nosplit
-func deferproc(siz int32, fn *funcval) { // arguments of fn follow fn
+func deferproc(fn func()) {
 	gp := getg()
 	if gp.m.curg != gp {
 		// go code on the system stack can't defer
 		throw("defer on system stack")
 	}
 
-	if goexperiment.RegabiDefer && siz != 0 {
-		// TODO: Make deferproc just take a func().
-		throw("defer with non-empty frame")
-	}
-
-	// the arguments of fn are in a perilous state. The stack map
-	// for deferproc does not describe them. So we can't let garbage
-	// collection or stack copying trigger until we've copied them out
-	// to somewhere safe. The memmove below does that.
-	// Until the copy completes, we can only call nosplit routines.
-	sp := getcallersp()
-	argp := uintptr(unsafe.Pointer(&fn)) + unsafe.Sizeof(fn)
-	callerpc := getcallerpc()
-
-	d := newdefer(siz)
+	d := newdefer()
 	if d._panic != nil {
 		throw("deferproc: d.panic != nil after newdefer")
 	}
 	d.link = gp._defer
 	gp._defer = d
 	d.fn = fn
-	d.pc = callerpc
-	d.sp = sp
-	switch siz {
-	case 0:
-		// Do nothing.
-	case sys.PtrSize:
-		*(*uintptr)(deferArgs(d)) = *(*uintptr)(unsafe.Pointer(argp))
-	default:
-		memmove(deferArgs(d), unsafe.Pointer(argp), uintptr(siz))
-	}
+	d.pc = getcallerpc()
+	// We must not be preempted between calling getcallersp and
+	// storing it to d.sp because getcallersp's result is a
+	// uintptr stack pointer.
+	d.sp = getcallersp()
 
 	// deferproc returns 0 normally.
 	// a deferred func that stops a panic
@@ -280,12 +259,10 @@ func deferproc(siz int32, fn *funcval) { // arguments of fn follow fn
 }
 
 // deferprocStack queues a new deferred function with a defer record on the stack.
-// The defer record must have its siz and fn fields initialized.
+// The defer record must have its fn field initialized.
 // All other fields can contain junk.
-// The defer record must be immediately followed in memory by
-// the arguments of the defer.
-// Nosplit because the arguments on the stack won't be scanned
-// until the defer record is spliced into the gp._defer list.
+// Nosplit because of the uninitialized pointer fields on the stack.
+//
 //go:nosplit
 func deferprocStack(d *_defer) {
 	gp := getg()
@@ -293,10 +270,7 @@ func deferprocStack(d *_defer) {
 		// go code on the system stack can't defer
 		throw("defer on system stack")
 	}
-	if goexperiment.RegabiDefer && d.siz != 0 {
-		throw("defer with non-empty frame")
-	}
-	// siz and fn are already set.
+	// fn is already set.
 	// The other fields are junk on entry to deferprocStack and
 	// are initialized here.
 	d.started = false
@@ -327,132 +301,37 @@ func deferprocStack(d *_defer) {
 	// been set and must not be clobbered.
 }
 
-// Small malloc size classes >= 16 are the multiples of 16: 16, 32, 48, 64, 80, 96, 112, 128, 144, ...
-// Each P holds a pool for defers with small arg sizes.
-// Assign defer allocations to pools by rounding to 16, to match malloc size classes.
-
-const (
-	deferHeaderSize = unsafe.Sizeof(_defer{})
-	minDeferAlloc   = (deferHeaderSize + 15) &^ 15
-	minDeferArgs    = minDeferAlloc - deferHeaderSize
-)
-
-// defer size class for arg size sz
-//go:nosplit
-func deferclass(siz uintptr) uintptr {
-	if siz <= minDeferArgs {
-		return 0
-	}
-	return (siz - minDeferArgs + 15) / 16
-}
-
-// total size of memory block for defer with arg size sz
-func totaldefersize(siz uintptr) uintptr {
-	if siz <= minDeferArgs {
-		return minDeferAlloc
-	}
-	return deferHeaderSize + siz
-}
-
-// Ensure that defer arg sizes that map to the same defer size class
-// also map to the same malloc size class.
-func testdefersizes() {
-	var m [len(p{}.deferpool)]int32
-
-	for i := range m {
-		m[i] = -1
-	}
-	for i := uintptr(0); ; i++ {
-		defersc := deferclass(i)
-		if defersc >= uintptr(len(m)) {
-			break
-		}
-		siz := roundupsize(totaldefersize(i))
-		if m[defersc] < 0 {
-			m[defersc] = int32(siz)
-			continue
-		}
-		if m[defersc] != int32(siz) {
-			print("bad defer size class: i=", i, " siz=", siz, " defersc=", defersc, "\n")
-			throw("bad defer size class")
-		}
-	}
-}
-
-// The arguments associated with a deferred call are stored
-// immediately after the _defer header in memory.
-//go:nosplit
-func deferArgs(d *_defer) unsafe.Pointer {
-	if d.siz == 0 {
-		// Avoid pointer past the defer allocation.
-		return nil
-	}
-	return add(unsafe.Pointer(d), unsafe.Sizeof(*d))
-}
-
-// deferFunc returns d's deferred function. This is temporary while we
-// support both modes of GOEXPERIMENT=regabidefer. Once we commit to
-// that experiment, we should change the type of d.fn.
-//go:nosplit
-func deferFunc(d *_defer) func() {
-	if !goexperiment.RegabiDefer {
-		throw("requires GOEXPERIMENT=regabidefer")
-	}
-	var fn func()
-	*(**funcval)(unsafe.Pointer(&fn)) = d.fn
-	return fn
-}
-
-var deferType *_type // type of _defer struct
-
-func init() {
-	var x interface{}
-	x = (*_defer)(nil)
-	deferType = (*(**ptrtype)(unsafe.Pointer(&x))).elem
-}
+// Each P holds a pool for defers.
 
 // Allocate a Defer, usually using per-P pool.
 // Each defer must be released with freedefer.  The defer is not
 // added to any defer chain yet.
-//
-// This must not grow the stack because there may be a frame without
-// stack map information when this is called.
-//
-//go:nosplit
-func newdefer(siz int32) *_defer {
+func newdefer() *_defer {
 	var d *_defer
-	sc := deferclass(uintptr(siz))
-	gp := getg()
-	if sc < uintptr(len(p{}.deferpool)) {
-		pp := gp.m.p.ptr()
-		if len(pp.deferpool[sc]) == 0 && sched.deferpool[sc] != nil {
-			// Take the slow path on the system stack so
-			// we don't grow newdefer's stack.
-			systemstack(func() {
-				lock(&sched.deferlock)
-				for len(pp.deferpool[sc]) < cap(pp.deferpool[sc])/2 && sched.deferpool[sc] != nil {
-					d := sched.deferpool[sc]
-					sched.deferpool[sc] = d.link
-					d.link = nil
-					pp.deferpool[sc] = append(pp.deferpool[sc], d)
-				}
-				unlock(&sched.deferlock)
-			})
-		}
-		if n := len(pp.deferpool[sc]); n > 0 {
-			d = pp.deferpool[sc][n-1]
-			pp.deferpool[sc][n-1] = nil
-			pp.deferpool[sc] = pp.deferpool[sc][:n-1]
+	mp := acquirem()
+	pp := mp.p.ptr()
+	if len(pp.deferpool) == 0 && sched.deferpool != nil {
+		lock(&sched.deferlock)
+		for len(pp.deferpool) < cap(pp.deferpool)/2 && sched.deferpool != nil {
+			d := sched.deferpool
+			sched.deferpool = d.link
+			d.link = nil
+			pp.deferpool = append(pp.deferpool, d)
 		}
+		unlock(&sched.deferlock)
 	}
+	if n := len(pp.deferpool); n > 0 {
+		d = pp.deferpool[n-1]
+		pp.deferpool[n-1] = nil
+		pp.deferpool = pp.deferpool[:n-1]
+	}
+	releasem(mp)
+	mp, pp = nil, nil
+
 	if d == nil {
-		// Allocate new defer+args.
-		systemstack(func() {
-			total := roundupsize(totaldefersize(uintptr(siz)))
-			d = (*_defer)(mallocgc(total, deferType, true))
-		})
+		// Allocate new defer.
+		d = new(_defer)
 	}
-	d.siz = siz
 	d.heap = true
 	return d
 }
@@ -460,11 +339,16 @@ func newdefer(siz int32) *_defer {
 // Free the given defer.
 // The defer cannot be used after this call.
 //
-// This must not grow the stack because there may be a frame without a
-// stack map when this is called.
+// This is nosplit because the incoming defer is in a perilous state.
+// It's not on any defer list, so stack copying won't adjust stack
+// pointers in it (namely, d.link). Hence, if we were to copy the
+// stack, d could then contain a stale pointer.
 //
 //go:nosplit
 func freedefer(d *_defer) {
+	d.link = nil
+	// After this point we can copy the stack.
+
 	if d._panic != nil {
 		freedeferpanic()
 	}
@@ -474,53 +358,36 @@ func freedefer(d *_defer) {
 	if !d.heap {
 		return
 	}
-	sc := deferclass(uintptr(d.siz))
-	if sc >= uintptr(len(p{}.deferpool)) {
-		return
-	}
-	pp := getg().m.p.ptr()
-	if len(pp.deferpool[sc]) == cap(pp.deferpool[sc]) {
+
+	mp := acquirem()
+	pp := mp.p.ptr()
+	if len(pp.deferpool) == cap(pp.deferpool) {
 		// Transfer half of local cache to the central cache.
-		//
-		// Take this slow path on the system stack so
-		// we don't grow freedefer's stack.
-		systemstack(func() {
-			var first, last *_defer
-			for len(pp.deferpool[sc]) > cap(pp.deferpool[sc])/2 {
-				n := len(pp.deferpool[sc])
-				d := pp.deferpool[sc][n-1]
-				pp.deferpool[sc][n-1] = nil
-				pp.deferpool[sc] = pp.deferpool[sc][:n-1]
-				if first == nil {
-					first = d
-				} else {
-					last.link = d
-				}
-				last = d
+		var first, last *_defer
+		for len(pp.deferpool) > cap(pp.deferpool)/2 {
+			n := len(pp.deferpool)
+			d := pp.deferpool[n-1]
+			pp.deferpool[n-1] = nil
+			pp.deferpool = pp.deferpool[:n-1]
+			if first == nil {
+				first = d
+			} else {
+				last.link = d
 			}
-			lock(&sched.deferlock)
-			last.link = sched.deferpool[sc]
-			sched.deferpool[sc] = first
-			unlock(&sched.deferlock)
-		})
+			last = d
+		}
+		lock(&sched.deferlock)
+		last.link = sched.deferpool
+		sched.deferpool = first
+		unlock(&sched.deferlock)
 	}
 
-	// These lines used to be simply `*d = _defer{}` but that
-	// started causing a nosplit stack overflow via typedmemmove.
-	d.siz = 0
-	d.started = false
-	d.openDefer = false
-	d.sp = 0
-	d.pc = 0
-	d.framepc = 0
-	d.varp = 0
-	d.fd = nil
-	// d._panic and d.fn must be nil already.
-	// If not, we would have called freedeferpanic or freedeferfn above,
-	// both of which throw.
-	d.link = nil
+	*d = _defer{}
 
-	pp.deferpool[sc] = append(pp.deferpool[sc], d)
+	pp.deferpool = append(pp.deferpool, d)
+
+	releasem(mp)
+	mp, pp = nil, nil
 }
 
 // Separate function so that it can split stack.
@@ -535,66 +402,39 @@ func freedeferfn() {
 	throw("freedefer with d.fn != nil")
 }
 
-// Run a deferred function if there is one.
+// deferreturn runs deferred functions for the caller's frame.
 // The compiler inserts a call to this at the end of any
 // function which calls defer.
-// If there is a deferred function, this will call runtime·jmpdefer,
-// which will jump to the deferred function such that it appears
-// to have been called by the caller of deferreturn at the point
-// just before deferreturn was called. The effect is that deferreturn
-// is called again and again until there are no more deferred functions.
-//
-// Declared as nosplit, because the function should not be preempted once we start
-// modifying the caller's frame in order to reuse the frame to call the deferred
-// function.
-//
-//go:nosplit
 func deferreturn() {
 	gp := getg()
-	d := gp._defer
-	if d == nil {
-		return
-	}
-	sp := getcallersp()
-	if d.sp != sp {
-		return
-	}
-	if d.openDefer {
-		done := runOpenDeferFrame(gp, d)
-		if !done {
-			throw("unfinished open-coded defers in deferreturn")
+	for {
+		d := gp._defer
+		if d == nil {
+			return
 		}
+		sp := getcallersp()
+		if d.sp != sp {
+			return
+		}
+		if d.openDefer {
+			done := runOpenDeferFrame(gp, d)
+			if !done {
+				throw("unfinished open-coded defers in deferreturn")
+			}
+			gp._defer = d.link
+			freedefer(d)
+			// If this frame uses open defers, then this
+			// must be the only defer record for the
+			// frame, so we can just return.
+			return
+		}
+
+		fn := d.fn
+		d.fn = nil
 		gp._defer = d.link
 		freedefer(d)
-		return
+		fn()
 	}
-
-	// Moving arguments around.
-	//
-	// Everything called after this point must be recursively
-	// nosplit because the garbage collector won't know the form
-	// of the arguments until the jmpdefer can flip the PC over to
-	// fn.
-	argp := getcallersp() + sys.MinFrameSize
-	switch d.siz {
-	case 0:
-		// Do nothing.
-	case sys.PtrSize:
-		*(*uintptr)(unsafe.Pointer(argp)) = *(*uintptr)(deferArgs(d))
-	default:
-		memmove(unsafe.Pointer(argp), deferArgs(d), uintptr(d.siz))
-	}
-	fn := d.fn
-	d.fn = nil
-	gp._defer = d.link
-	freedefer(d)
-	// If the defer function pointer is nil, force the seg fault to happen
-	// here rather than in jmpdefer. gentraceback() throws an error if it is
-	// called with a callback on an LR architecture and jmpdefer is on the
-	// stack, because the stack trace can be incorrect in that case - see
-	// issue #8153).
-	_ = fn.fn
-	jmpdefer(fn, argp)
 }
 
 // Goexit terminates the goroutine that calls it. No other goroutine is affected.
@@ -655,15 +495,9 @@ func Goexit() {
 				addOneOpenDeferFrame(gp, 0, nil)
 			}
 		} else {
-			if goexperiment.RegabiDefer {
-				// Save the pc/sp in deferCallSave(), so we can "recover" back to this
-				// loop if necessary.
-				deferCallSave(&p, deferFunc(d))
-			} else {
-				// Save the pc/sp in reflectcallSave(), so we can "recover" back to this
-				// loop if necessary.
-				reflectcallSave(&p, unsafe.Pointer(d.fn), deferArgs(d), uint32(d.siz))
-			}
+			// Save the pc/sp in deferCallSave(), so we can "recover" back to this
+			// loop if necessary.
+			deferCallSave(&p, d.fn)
 		}
 		if p.aborted {
 			// We had a recursive panic in the defer d we started, and
@@ -783,8 +617,7 @@ func addOneOpenDeferFrame(gp *g, pc uintptr, sp unsafe.Pointer) {
 					throw("missing deferreturn")
 				}
 
-				maxargsize, _ := readvarintUnsafe(fd)
-				d1 := newdefer(int32(maxargsize))
+				d1 := newdefer()
 				d1.openDefer = true
 				d1._panic = nil
 				// These are the pc/sp to set after we've
@@ -845,57 +678,29 @@ func runOpenDeferFrame(gp *g, d *_defer) bool {
 	done := true
 	fd := d.fd
 
-	// Skip the maxargsize
-	_, fd = readvarintUnsafe(fd)
 	deferBitsOffset, fd := readvarintUnsafe(fd)
 	nDefers, fd := readvarintUnsafe(fd)
 	deferBits := *(*uint8)(unsafe.Pointer(d.varp - uintptr(deferBitsOffset)))
 
 	for i := int(nDefers) - 1; i >= 0; i-- {
 		// read the funcdata info for this defer
-		var argWidth, closureOffset, nArgs uint32
-		argWidth, fd = readvarintUnsafe(fd)
+		var closureOffset uint32
 		closureOffset, fd = readvarintUnsafe(fd)
-		nArgs, fd = readvarintUnsafe(fd)
-		if goexperiment.RegabiDefer && argWidth != 0 {
-			throw("defer with non-empty frame")
-		}
 		if deferBits&(1< 0 {
 		growstack(n - 1)
@@ -619,7 +632,7 @@ func growstack(n int) {
 }
 
 //go:noinline
-func use(x [8 << 16]byte) {}
+func use(x [8 << 18]byte) {}
 
 func TestBlockProfile(t *testing.T) {
 	type TestCase struct {
diff --git a/src/runtime/pprof/proto.go b/src/runtime/pprof/proto.go
index bdb4454b6e1..68625139566 100644
--- a/src/runtime/pprof/proto.go
+++ b/src/runtime/pprof/proto.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"compress/gzip"
 	"fmt"
+	"internal/abi"
 	"io"
 	"os"
 	"runtime"
@@ -21,11 +22,6 @@ import (
 // (The name shows up in the pprof graphs.)
 func lostProfileEvent() { lostProfileEvent() }
 
-// funcPC returns the PC for the func value f.
-func funcPC(f interface{}) uintptr {
-	return *(*[2]*uintptr)(unsafe.Pointer(&f))[1]
-}
-
 // A profileBuilder writes a profile incrementally from a
 // stream of profile samples delivered by the runtime.
 type profileBuilder struct {
@@ -325,7 +321,7 @@ func (b *profileBuilder) addCPUData(data []uint64, tags []unsafe.Pointer) error
 				// gentraceback guarantees that PCs in the
 				// stack can be unconditionally decremented and
 				// still be valid, so we must do the same.
-				uint64(funcPC(lostProfileEvent) + 1),
+				uint64(abi.FuncPCABIInternal(lostProfileEvent) + 1),
 			}
 		}
 		b.m.lookup(stk, tag).count += int64(count)
diff --git a/src/runtime/pprof/proto_test.go b/src/runtime/pprof/proto_test.go
index 5eb1aab1401..d052b9fa421 100644
--- a/src/runtime/pprof/proto_test.go
+++ b/src/runtime/pprof/proto_test.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"internal/abi"
 	"internal/profile"
 	"internal/testenv"
 	"os"
@@ -97,11 +98,11 @@ func testPCs(t *testing.T) (addr1, addr2 uint64, map1, map2 *profile.Mapping) {
 		map2 = mprof.Mapping[1]
 		map2.BuildID, _ = elfBuildID(map2.File)
 	case "js":
-		addr1 = uint64(funcPC(f1))
-		addr2 = uint64(funcPC(f2))
+		addr1 = uint64(abi.FuncPCABIInternal(f1))
+		addr2 = uint64(abi.FuncPCABIInternal(f2))
 	default:
-		addr1 = uint64(funcPC(f1))
-		addr2 = uint64(funcPC(f2))
+		addr1 = uint64(abi.FuncPCABIInternal(f1))
+		addr2 = uint64(abi.FuncPCABIInternal(f2))
 		// Fake mapping - HasFunctions will be true because two PCs from Go
 		// will be fully symbolized.
 		fake := &profile.Mapping{ID: 1, HasFunctions: true}
diff --git a/src/runtime/preempt.go b/src/runtime/preempt.go
index 372185266f7..a38ab793986 100644
--- a/src/runtime/preempt.go
+++ b/src/runtime/preempt.go
@@ -53,8 +53,9 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -315,12 +316,12 @@ func asyncPreempt2() {
 var asyncPreemptStack = ^uintptr(0)
 
 func init() {
-	f := findfunc(funcPC(asyncPreempt))
+	f := findfunc(abi.FuncPCABI0(asyncPreempt))
 	total := funcMaxSPDelta(f)
-	f = findfunc(funcPC(asyncPreempt2))
+	f = findfunc(abi.FuncPCABIInternal(asyncPreempt2))
 	total += funcMaxSPDelta(f)
 	// Add some overhead for return PCs, etc.
-	asyncPreemptStack = uintptr(total) + 8*sys.PtrSize
+	asyncPreemptStack = uintptr(total) + 8*goarch.PtrSize
 	if asyncPreemptStack > _StackLimit {
 		// We need more than the nosplit limit. This isn't
 		// unsafe, but it may limit asynchronous preemption.
@@ -413,6 +414,8 @@ func isAsyncSafePoint(gp *g, pc, sp, lr uintptr) (bool, uintptr) {
 		//
 		// TODO: Are there cases that are safe but don't have a
 		// locals pointer map, like empty frame functions?
+		// It might be possible to preempt any assembly functions
+		// except the ones that have funcFlag_SPWRITE set in f.flag.
 		return false, 0
 	}
 	name := funcname(f)
diff --git a/src/runtime/preempt_386.s b/src/runtime/preempt_386.s
index a803b24dc6f..c3a5fa1f361 100644
--- a/src/runtime/preempt_386.s
+++ b/src/runtime/preempt_386.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	PUSHFL
 	ADJSP $156
 	NOP SP
diff --git a/src/runtime/preempt_amd64.s b/src/runtime/preempt_amd64.s
index dc7af806d32..31f7c8b66f5 100644
--- a/src/runtime/preempt_amd64.s
+++ b/src/runtime/preempt_amd64.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	PUSHQ BP
 	MOVQ SP, BP
 	// Save flags before clobbering them
diff --git a/src/runtime/preempt_arm.s b/src/runtime/preempt_arm.s
index bbc9fbb1eae..8f243c0dcd6 100644
--- a/src/runtime/preempt_arm.s
+++ b/src/runtime/preempt_arm.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVW.W R14, -188(R13)
 	MOVW R0, 4(R13)
 	MOVW R1, 8(R13)
diff --git a/src/runtime/preempt_arm64.s b/src/runtime/preempt_arm64.s
index 2b70a28479d..36ee13282c7 100644
--- a/src/runtime/preempt_arm64.s
+++ b/src/runtime/preempt_arm64.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVD R30, -496(RSP)
 	SUB $496, RSP
 	#ifdef GOOS_linux
diff --git a/src/runtime/preempt_mips64x.s b/src/runtime/preempt_mips64x.s
index 0d0c157c36c..c1249e382e2 100644
--- a/src/runtime/preempt_mips64x.s
+++ b/src/runtime/preempt_mips64x.s
@@ -1,12 +1,12 @@
 // Code generated by mkpreempt.go; DO NOT EDIT.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVV R31, -488(R29)
 	SUBV $488, R29
 	MOVV R1, 8(R29)
diff --git a/src/runtime/preempt_mipsx.s b/src/runtime/preempt_mipsx.s
index 86d3a918d33..70b79e05b99 100644
--- a/src/runtime/preempt_mipsx.s
+++ b/src/runtime/preempt_mipsx.s
@@ -1,12 +1,12 @@
 // Code generated by mkpreempt.go; DO NOT EDIT.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVW R31, -244(R29)
 	SUB $244, R29
 	MOVW R1, 4(R29)
diff --git a/src/runtime/preempt_ppc64x.s b/src/runtime/preempt_ppc64x.s
index 90634386dbf..7ed4021dde7 100644
--- a/src/runtime/preempt_ppc64x.s
+++ b/src/runtime/preempt_ppc64x.s
@@ -1,12 +1,12 @@
 // Code generated by mkpreempt.go; DO NOT EDIT.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVD R31, -488(R1)
 	MOVD LR, R31
 	MOVDU R31, -520(R1)
diff --git a/src/runtime/preempt_riscv64.s b/src/runtime/preempt_riscv64.s
index d4f9cc277f4..eb68dcba2b9 100644
--- a/src/runtime/preempt_riscv64.s
+++ b/src/runtime/preempt_riscv64.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOV X1, -472(X2)
 	ADD $-472, X2
 	MOV X3, 8(X2)
diff --git a/src/runtime/preempt_s390x.s b/src/runtime/preempt_s390x.s
index c6f11571df7..ca9e47cde17 100644
--- a/src/runtime/preempt_s390x.s
+++ b/src/runtime/preempt_s390x.s
@@ -3,8 +3,7 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	IPM R10
 	MOVD R14, -248(R15)
 	ADD $-248, R15
diff --git a/src/runtime/preempt_wasm.s b/src/runtime/preempt_wasm.s
index da90e8aa6dd..0cf57d3d226 100644
--- a/src/runtime/preempt_wasm.s
+++ b/src/runtime/preempt_wasm.s
@@ -3,7 +3,6 @@
 #include "go_asm.h"
 #include "textflag.h"
 
-// Note: asyncPreempt doesn't use the internal ABI, but we must be able to inject calls to it from the signal handler, so Go code has to see the PC of this function literally.
-TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
+TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	// No async preemption on wasm
 	UNDEF
diff --git a/src/runtime/print.go b/src/runtime/print.go
index f15296cf024..59a91203b9f 100644
--- a/src/runtime/print.go
+++ b/src/runtime/print.go
@@ -5,8 +5,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -271,7 +271,7 @@ func hexdumpWords(p, end uintptr, mark func(uintptr) byte) {
 	var markbuf [1]byte
 	markbuf[0] = ' '
 	minhexdigits = int(unsafe.Sizeof(uintptr(0)) * 2)
-	for i := uintptr(0); p+i < end; i += sys.PtrSize {
+	for i := uintptr(0); p+i < end; i += goarch.PtrSize {
 		if i%16 == 0 {
 			if i != 0 {
 				println()
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index d9f8c65530c..cde1a115830 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -7,7 +7,7 @@ package runtime
 import (
 	"internal/abi"
 	"internal/cpu"
-	"internal/goexperiment"
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -152,7 +152,7 @@ func main() {
 	// Max stack size is 1 GB on 64-bit, 250 MB on 32-bit.
 	// Using decimal instead of binary GB and MB because
 	// they look nicer in the stack overflow failure message.
-	if sys.PtrSize == 8 {
+	if goarch.PtrSize == 8 {
 		maxstacksize = 1000000000
 	} else {
 		maxstacksize = 250000000
@@ -466,18 +466,6 @@ func releaseSudog(s *sudog) {
 	releasem(mp)
 }
 
-// funcPC returns the entry PC of the function f.
-// It assumes that f is a func value. Otherwise the behavior is undefined.
-// CAREFUL: In programs with plugins, funcPC can return different values
-// for the same function (because there are actually multiple copies of
-// the same function in the address space). To be safe, don't use the
-// results of this function in any == expression. It is only safe to
-// use the result as an address at which to start executing code.
-//go:nosplit
-func funcPC(f interface{}) uintptr {
-	return *(*uintptr)(efaceOf(&f).data)
-}
-
 // called from assembly
 func badmcall(fn func(*g)) {
 	throw("runtime: mcall called on m->g0 stack")
@@ -529,8 +517,8 @@ var (
 	allglock mutex
 	allgs    []*g
 
-	// allglen and allgptr are atomic variables that contain len(allg) and
-	// &allg[0] respectively. Proper ordering depends on totally-ordered
+	// allglen and allgptr are atomic variables that contain len(allgs) and
+	// &allgs[0] respectively. Proper ordering depends on totally-ordered
 	// loads and stores. Writes are protected by allglock.
 	//
 	// allgptr is updated before allglen. Readers should read allglen
@@ -568,7 +556,7 @@ func atomicAllG() (**g, uintptr) {
 
 // atomicAllGIndex returns ptr[i] with the allgptr returned from atomicAllG.
 func atomicAllGIndex(ptr **g, i uintptr) *g {
-	return *(**g)(add(unsafe.Pointer(ptr), i*sys.PtrSize))
+	return *(**g)(add(unsafe.Pointer(ptr), i*goarch.PtrSize))
 }
 
 // forEachG calls fn on every G from allgs.
@@ -1303,7 +1291,7 @@ func usesLibcall() bool {
 	case "aix", "darwin", "illumos", "ios", "solaris", "windows":
 		return true
 	case "openbsd":
-		return GOARCH == "386" || GOARCH == "amd64" || GOARCH == "arm64"
+		return GOARCH == "386" || GOARCH == "amd64" || GOARCH == "arm" || GOARCH == "arm64"
 	}
 	return false
 }
@@ -1316,7 +1304,7 @@ func mStackIsSystemAllocated() bool {
 		return true
 	case "openbsd":
 		switch GOARCH {
-		case "386", "amd64", "arm64":
+		case "386", "amd64", "arm", "arm64":
 			return true
 		}
 	}
@@ -1522,6 +1510,8 @@ found:
 	}
 	unlock(&sched.lock)
 
+	atomic.Xadd64(&ncgocall, int64(m.ncgocall))
+
 	// Release the P.
 	handoffp(releasep())
 	// After this point we must not have write barriers.
@@ -2025,7 +2015,7 @@ func oneNewExtraM() {
 	gp := malg(4096)
 	gp.sched.pc = abi.FuncPCABI0(goexit) + sys.PCQuantum
 	gp.sched.sp = gp.stack.hi
-	gp.sched.sp -= 4 * sys.PtrSize // extra space in case of reads slightly beyond frame
+	gp.sched.sp -= 4 * goarch.PtrSize // extra space in case of reads slightly beyond frame
 	gp.sched.lr = 0
 	gp.sched.g = guintptr(unsafe.Pointer(gp))
 	gp.syscallpc = gp.sched.pc
@@ -2043,7 +2033,7 @@ func oneNewExtraM() {
 	gp.lockedm.set(mp)
 	gp.goid = int64(atomic.Xadd64(&sched.goidgen, 1))
 	if raceenabled {
-		gp.racectx = racegostart(funcPC(newextram) + sys.PCQuantum)
+		gp.racectx = racegostart(abi.FuncPCABIInternal(newextram) + sys.PCQuantum)
 	}
 	// put on allg for garbage collector
 	allgadd(gp)
@@ -2236,7 +2226,7 @@ func newm1(mp *m) {
 		}
 		ts.g.set(mp.g0)
 		ts.tls = (*uint64)(unsafe.Pointer(&mp.tls[0]))
-		ts.fn = unsafe.Pointer(funcPC(mstart))
+		ts.fn = unsafe.Pointer(abi.FuncPCABI0(mstart))
 		if msanenabled {
 			msanwrite(unsafe.Pointer(&ts), unsafe.Sizeof(ts))
 		}
@@ -3132,24 +3122,33 @@ func checkIdleGCNoP() (*p, *g) {
 		return nil, nil
 	}
 
-	// Work is available; we can start an idle GC worker only if
-	// there is an available P and available worker G.
+	// Work is available; we can start an idle GC worker only if there is
+	// an available P and available worker G.
 	//
-	// We can attempt to acquire these in either order. Workers are
-	// almost always available (see comment in findRunnableGCWorker
-	// for the one case there may be none). Since we're slightly
-	// less likely to find a P, check for that first.
+	// We can attempt to acquire these in either order, though both have
+	// synchronization concerns (see below). Workers are almost always
+	// available (see comment in findRunnableGCWorker for the one case
+	// there may be none). Since we're slightly less likely to find a P,
+	// check for that first.
+	//
+	// Synchronization: note that we must hold sched.lock until we are
+	// committed to keeping it. Otherwise we cannot put the unnecessary P
+	// back in sched.pidle without performing the full set of idle
+	// transition checks.
+	//
+	// If we were to check gcBgMarkWorkerPool first, we must somehow handle
+	// the assumption in gcControllerState.findRunnableGCWorker that an
+	// empty gcBgMarkWorkerPool is only possible if gcMarkDone is running.
 	lock(&sched.lock)
 	pp := pidleget()
-	unlock(&sched.lock)
 	if pp == nil {
+		unlock(&sched.lock)
 		return nil, nil
 	}
 
-	// Now that we own a P, gcBlackenEnabled can't change
-	// (as it requires STW).
+	// Now that we own a P, gcBlackenEnabled can't change (as it requires
+	// STW).
 	if gcBlackenEnabled == 0 {
-		lock(&sched.lock)
 		pidleput(pp)
 		unlock(&sched.lock)
 		return nil, nil
@@ -3157,12 +3156,13 @@ func checkIdleGCNoP() (*p, *g) {
 
 	node := (*gcBgMarkWorkerNode)(gcBgMarkWorkerPool.pop())
 	if node == nil {
-		lock(&sched.lock)
 		pidleput(pp)
 		unlock(&sched.lock)
 		return nil, nil
 	}
 
+	unlock(&sched.lock)
+
 	return pp, node.gp.ptr()
 }
 
@@ -3560,6 +3560,21 @@ func preemptPark(gp *g) {
 		throw("bad g status")
 	}
 	gp.waitreason = waitReasonPreempted
+
+	if gp.asyncSafePoint {
+		// Double-check that async preemption does not
+		// happen in SPWRITE assembly functions.
+		// isAsyncSafePoint must exclude this case.
+		f := findfunc(gp.sched.pc)
+		if !f.valid() {
+			throw("preempt at unknown pc")
+		}
+		if f.flag&funcFlag_SPWRITE != 0 {
+			println("runtime: unexpected SPWRITE function", funcname(f), "in async preempt")
+			throw("preempt SPWRITE")
+		}
+	}
+
 	// Transition from _Grunning to _Gscan|_Gpreempted. We can't
 	// be in _Grunning when we dropg because then we'd be running
 	// without an M, but the moment we're in _Gpreempted,
@@ -4058,8 +4073,16 @@ func exitsyscall0(gp *g) {
 	if schedEnabled(gp) {
 		_p_ = pidleget()
 	}
+	var locked bool
 	if _p_ == nil {
 		globrunqput(gp)
+
+		// Below, we stoplockedm if gp is locked. globrunqput releases
+		// ownership of gp, so we must check if gp is locked prior to
+		// committing the release by unlocking sched.lock, otherwise we
+		// could race with another M transitioning gp from unlocked to
+		// locked.
+		locked = gp.lockedm != 0
 	} else if atomic.Load(&sched.sysmonwait) != 0 {
 		atomic.Store(&sched.sysmonwait, 0)
 		notewakeup(&sched.sysmonnote)
@@ -4069,7 +4092,7 @@ func exitsyscall0(gp *g) {
 		acquirep(_p_)
 		execute(gp, false) // Never returns.
 	}
-	if gp.lockedm != 0 {
+	if locked {
 		// Wait until another thread schedules gp and so m again.
 		//
 		// N.B. lockedm must be this M, as this g was running on this M
@@ -4081,7 +4104,10 @@ func exitsyscall0(gp *g) {
 	schedule() // Never returns.
 }
 
-func beforefork() {
+// Called from syscall package before fork.
+//go:linkname syscall_runtime_BeforeFork syscall.runtime_BeforeFork
+//go:nosplit
+func syscall_runtime_BeforeFork() {
 	gp := getg().m.curg
 
 	// Block signals during a fork, so that the child does not run
@@ -4098,14 +4124,10 @@ func beforefork() {
 	gp.stackguard0 = stackFork
 }
 
-// Called from syscall package before fork.
-//go:linkname syscall_runtime_BeforeFork syscall.runtime_BeforeFork
+// Called from syscall package after fork in parent.
+//go:linkname syscall_runtime_AfterFork syscall.runtime_AfterFork
 //go:nosplit
-func syscall_runtime_BeforeFork() {
-	systemstack(beforefork)
-}
-
-func afterfork() {
+func syscall_runtime_AfterFork() {
 	gp := getg().m.curg
 
 	// See the comments in beforefork.
@@ -4116,13 +4138,6 @@ func afterfork() {
 	gp.m.locks--
 }
 
-// Called from syscall package after fork in parent.
-//go:linkname syscall_runtime_AfterFork syscall.runtime_AfterFork
-//go:nosplit
-func syscall_runtime_AfterFork() {
-	systemstack(afterfork)
-}
-
 // inForkedChild is true while manipulating signals in the child process.
 // This is used to avoid calling libc functions in case we are using vfork.
 var inForkedChild bool
@@ -4197,27 +4212,14 @@ func malg(stacksize int32) *g {
 	return newg
 }
 
-// Create a new g running fn with siz bytes of arguments.
+// Create a new g running fn.
 // Put it on the queue of g's waiting to run.
 // The compiler turns a go statement into a call to this.
-//
-// The stack layout of this call is unusual: it assumes that the
-// arguments to pass to fn are on the stack sequentially immediately
-// after &fn. Hence, they are logically part of newproc's argument
-// frame, even though they don't appear in its signature (and can't
-// because their types differ between call sites).
-//
-// This must be nosplit because this stack layout means there are
-// untyped arguments in newproc's argument frame. Stack copies won't
-// be able to adjust them and stack splits won't be able to copy them.
-//
-//go:nosplit
-func newproc(siz int32, fn *funcval) {
-	argp := add(unsafe.Pointer(&fn), sys.PtrSize)
+func newproc(fn *funcval) {
 	gp := getg()
 	pc := getcallerpc()
 	systemstack(func() {
-		newg := newproc1(fn, argp, siz, gp, pc)
+		newg := newproc1(fn, gp, pc)
 
 		_p_ := getg().m.p.ptr()
 		runqput(_p_, newg, true)
@@ -4228,24 +4230,10 @@ func newproc(siz int32, fn *funcval) {
 	})
 }
 
-// Create a new g in state _Grunnable, starting at fn, with narg bytes
-// of arguments starting at argp. callerpc is the address of the go
-// statement that created this. The caller is responsible for adding
-// the new g to the scheduler.
-//
-// This must run on the system stack because it's the continuation of
-// newproc, which cannot split the stack.
-//
-//go:systemstack
-func newproc1(fn *funcval, argp unsafe.Pointer, narg int32, callergp *g, callerpc uintptr) *g {
-	if goexperiment.RegabiDefer && narg != 0 {
-		// TODO: When we commit to GOEXPERIMENT=regabidefer,
-		// rewrite the comments for newproc and newproc1.
-		// newproc will no longer have a funny stack layout or
-		// need to be nosplit.
-		throw("go with non-empty frame")
-	}
-
+// Create a new g in state _Grunnable, starting at fn. callerpc is the
+// address of the go statement that created this. The caller is responsible
+// for adding the new g to the scheduler.
+func newproc1(fn *funcval, callergp *g, callerpc uintptr) *g {
 	_g_ := getg()
 
 	if fn == nil {
@@ -4253,16 +4241,6 @@ func newproc1(fn *funcval, argp unsafe.Pointer, narg int32, callergp *g, callerp
 		throw("go of nil func value")
 	}
 	acquirem() // disable preemption because it can be holding p in a local var
-	siz := narg
-	siz = (siz + 7) &^ 7
-
-	// We could allocate a larger initial stack if necessary.
-	// Not worth it: this is almost always an error.
-	// 4*PtrSize: extra space added below
-	// PtrSize: caller's LR (arm) or return address (x86, in gostartcall).
-	if siz >= _StackMin-4*sys.PtrSize-sys.PtrSize {
-		throw("newproc: function arguments too large for new goroutine")
-	}
 
 	_p_ := _g_.m.p.ptr()
 	newg := gfget(_p_)
@@ -4279,8 +4257,8 @@ func newproc1(fn *funcval, argp unsafe.Pointer, narg int32, callergp *g, callerp
 		throw("newproc1: new g is not Gdead")
 	}
 
-	totalSize := 4*sys.PtrSize + uintptr(siz) + sys.MinFrameSize // extra space in case of reads slightly beyond frame
-	totalSize += -totalSize & (sys.StackAlign - 1)               // align to StackAlign
+	totalSize := uintptr(4*goarch.PtrSize + sys.MinFrameSize) // extra space in case of reads slightly beyond frame
+	totalSize = alignUp(totalSize, sys.StackAlign)
 	sp := newg.stack.hi - totalSize
 	spArg := sp
 	if usesLR {
@@ -4289,24 +4267,6 @@ func newproc1(fn *funcval, argp unsafe.Pointer, narg int32, callergp *g, callerp
 		prepGoExitFrame(sp)
 		spArg += sys.MinFrameSize
 	}
-	if narg > 0 {
-		memmove(unsafe.Pointer(spArg), argp, uintptr(narg))
-		// This is a stack-to-stack copy. If write barriers
-		// are enabled and the source stack is grey (the
-		// destination is always black), then perform a
-		// barrier copy. We do this *after* the memmove
-		// because the destination stack may have garbage on
-		// it.
-		if writeBarrier.needed && !_g_.m.curg.gcscandone {
-			f := findfunc(fn.fn)
-			stkmap := (*stackmap)(funcdata(f, _FUNCDATA_ArgsPointerMaps))
-			if stkmap.nbit > 0 {
-				// We're in the prologue, so it's always stack map index 0.
-				bv := stackmapdata(stkmap, 0)
-				bulkBarrierBitmap(spArg, spArg, uintptr(bv.n)*sys.PtrSize, 0, bv.bytedata)
-			}
-		}
-	}
 
 	memclrNoHeapPointers(unsafe.Pointer(&newg.sched), unsafe.Sizeof(newg.sched))
 	newg.sched.sp = sp
@@ -4651,7 +4611,7 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) {
 		return
 	}
 
-	// On mips{,le}, 64bit atomics are emulated with spinlocks, in
+	// On mips{,le}/arm, 64bit atomics are emulated with spinlocks, in
 	// runtime/internal/atomic. If SIGPROF arrives while the program is inside
 	// the critical section, it creates a deadlock (when writing the sample).
 	// As a workaround, create a counter of SIGPROFs while in critical section
@@ -4664,6 +4624,13 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) {
 				return
 			}
 		}
+		if GOARCH == "arm" && goarm < 7 && GOOS == "linux" && pc&0xffff0000 == 0xffff0000 {
+			// runtime/internal/atomic functions call into kernel
+			// helpers on arm < 7. See
+			// runtime/internal/atomic/sys_linux_arm.s.
+			cpuprof.lostAtomic++
+			return
+		}
 	}
 
 	// Profiling runs concurrently with GC, so it must not allocate.
@@ -4716,16 +4683,16 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) {
 			// If all of the above has failed, account it against abstract "System" or "GC".
 			n = 2
 			if inVDSOPage(pc) {
-				pc = funcPC(_VDSO) + sys.PCQuantum
+				pc = abi.FuncPCABIInternal(_VDSO) + sys.PCQuantum
 			} else if pc > firstmoduledata.etext {
 				// "ExternalCode" is better than "etext".
-				pc = funcPC(_ExternalCode) + sys.PCQuantum
+				pc = abi.FuncPCABIInternal(_ExternalCode) + sys.PCQuantum
 			}
 			stk[0] = pc
 			if mp.preemptoff != "" {
-				stk[1] = funcPC(_GC) + sys.PCQuantum
+				stk[1] = abi.FuncPCABIInternal(_GC) + sys.PCQuantum
 			} else {
-				stk[1] = funcPC(_System) + sys.PCQuantum
+				stk[1] = abi.FuncPCABIInternal(_System) + sys.PCQuantum
 			}
 		}
 	}
@@ -4769,7 +4736,7 @@ func sigprofNonGoPC(pc uintptr) {
 	if prof.hz != 0 {
 		stk := []uintptr{
 			pc,
-			funcPC(_ExternalCode) + sys.PCQuantum,
+			abi.FuncPCABIInternal(_ExternalCode) + sys.PCQuantum,
 		}
 		cpuprof.addNonGo(stk)
 	}
@@ -4819,9 +4786,7 @@ func (pp *p) init(id int32) {
 	pp.id = id
 	pp.status = _Pgcstop
 	pp.sudogcache = pp.sudogbuf[:0]
-	for i := range pp.deferpool {
-		pp.deferpool[i] = pp.deferpoolbuf[i][:0]
-	}
+	pp.deferpool = pp.deferpoolbuf[:0]
 	pp.wbBuf.reset()
 	if pp.mcache == nil {
 		if id == 0 {
@@ -4884,7 +4849,6 @@ func (pp *p) destroy() {
 		moveTimers(plocal, pp.timers)
 		pp.timers = nil
 		pp.numTimers = 0
-		pp.adjustTimers = 0
 		pp.deletedTimers = 0
 		atomic.Store64(&pp.timer0When, 0)
 		unlock(&pp.timersLock)
@@ -4899,12 +4863,10 @@ func (pp *p) destroy() {
 		pp.sudogbuf[i] = nil
 	}
 	pp.sudogcache = pp.sudogbuf[:0]
-	for i := range pp.deferpool {
-		for j := range pp.deferpoolbuf[i] {
-			pp.deferpoolbuf[i][j] = nil
-		}
-		pp.deferpool[i] = pp.deferpoolbuf[i][:0]
+	for j := range pp.deferpoolbuf {
+		pp.deferpoolbuf[j] = nil
 	}
+	pp.deferpool = pp.deferpoolbuf[:0]
 	systemstack(func() {
 		for i := 0; i < pp.mspancache.len; i++ {
 			// Safe to call since the world is stopped.
@@ -6429,7 +6391,7 @@ func doInit(t *initTask) {
 		t.state = 1 // initialization in progress
 
 		for i := uintptr(0); i < t.ndeps; i++ {
-			p := add(unsafe.Pointer(t), (3+i)*sys.PtrSize)
+			p := add(unsafe.Pointer(t), (3+i)*goarch.PtrSize)
 			t2 := *(**initTask)(p)
 			doInit(t2)
 		}
@@ -6450,9 +6412,9 @@ func doInit(t *initTask) {
 			before = inittrace
 		}
 
-		firstFunc := add(unsafe.Pointer(t), (3+t.ndeps)*sys.PtrSize)
+		firstFunc := add(unsafe.Pointer(t), (3+t.ndeps)*goarch.PtrSize)
 		for i := uintptr(0); i < t.nfns; i++ {
-			p := add(firstFunc, i*sys.PtrSize)
+			p := add(firstFunc, i*goarch.PtrSize)
 			f := *(*func())(unsafe.Pointer(&p))
 			f()
 		}
@@ -6462,7 +6424,8 @@ func doInit(t *initTask) {
 			// Load stats non-atomically since tracinit is updated only by this init goroutine.
 			after := inittrace
 
-			pkg := funcpkgpath(findfunc(funcPC(firstFunc)))
+			f := *(*func())(unsafe.Pointer(&firstFunc))
+			pkg := funcpkgpath(findfunc(abi.FuncPCABIInternal(f)))
 
 			var sbuf [24]byte
 			print("init ", pkg, " @")
diff --git a/src/runtime/race.go b/src/runtime/race.go
index cc8c5db1bd2..7eaa9d2b721 100644
--- a/src/runtime/race.go
+++ b/src/runtime/race.go
@@ -8,6 +8,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"unsafe"
 )
 
@@ -343,7 +344,7 @@ func racereadrangepc1(addr, size, pc uintptr)
 func racewriterangepc1(addr, size, pc uintptr)
 func racecallbackthunk(uintptr)
 
-// racecall allows calling an arbitrary function f from C race runtime
+// racecall allows calling an arbitrary function fn from C race runtime
 // with up to 4 uintptr arguments.
 func racecall(fn *byte, arg0, arg1, arg2, arg3 uintptr)
 
@@ -361,7 +362,7 @@ func raceinit() (gctx, pctx uintptr) {
 		throw("raceinit: race build must use cgo")
 	}
 
-	racecall(&__tsan_init, uintptr(unsafe.Pointer(&gctx)), uintptr(unsafe.Pointer(&pctx)), funcPC(racecallbackthunk), 0)
+	racecall(&__tsan_init, uintptr(unsafe.Pointer(&gctx)), uintptr(unsafe.Pointer(&pctx)), abi.FuncPCABI0(racecallbackthunk), 0)
 
 	// Round data segment to page boundaries, because it's used in mmap().
 	start := ^uintptr(0)
diff --git a/src/runtime/race/output_test.go b/src/runtime/race/output_test.go
index 99052071d00..63fcd847dc7 100644
--- a/src/runtime/race/output_test.go
+++ b/src/runtime/race/output_test.go
@@ -148,7 +148,7 @@ exit status 66
 package main
 func main() {
 	done := make(chan bool)
-	x := 0
+	x := 0; _ = x
 	go func() {
 		x = 42
 		done <- true
@@ -162,7 +162,7 @@ func main() {
 package main
 func main() {
 	done := make(chan bool)
-	x := 0
+	x := 0; _ = x
 	go func() {
 		x = 42
 		done <- true
@@ -178,7 +178,7 @@ func main() {
 package main
 func main() {
 	done := make(chan bool)
-	x := 0
+	x := 0; _ = x
 	go func() {
 		x = 42
 		done <- true
diff --git a/src/runtime/race/syso_test.go b/src/runtime/race/syso_test.go
index cbce5a8f184..f5095737a4f 100644
--- a/src/runtime/race/syso_test.go
+++ b/src/runtime/race/syso_test.go
@@ -2,14 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !android && !js && !ppc64le
-// +build !android,!js,!ppc64le
-
-// Note: we don't run on Android or ppc64 because if there is any non-race test
-// file in this package, the OS tries to link the .syso file into the
-// test (even when we're not in race mode), which fails. I'm not sure
-// why, but easiest to just punt - as long as a single builder runs
-// this test, we're good.
+//go:build race
+// +build race
 
 package race
 
diff --git a/src/runtime/race_amd64.s b/src/runtime/race_amd64.s
index 58a919efe8d..d42e415dca5 100644
--- a/src/runtime/race_amd64.s
+++ b/src/runtime/race_amd64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build race
 // +build race
 
 #include "go_asm.h"
@@ -45,11 +46,7 @@
 // Defined as ABIInternal so as to avoid introducing a wrapper,
 // which would render runtime.getcallerpc ineffective.
 TEXT	runtime·raceread(SB), NOSPLIT, $0-8
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	AX, RARG1
-#else
-	MOVQ	addr+0(FP), RARG1
-#endif
 	MOVQ	(SP), RARG2
 	// void __tsan_read(ThreadState *thr, void *addr, void *pc);
 	MOVQ	$__tsan_read(SB), AX
@@ -75,11 +72,7 @@ TEXT	runtime·racereadpc(SB), NOSPLIT, $0-24
 // Defined as ABIInternal so as to avoid introducing a wrapper,
 // which would render runtime.getcallerpc ineffective.
 TEXT	runtime·racewrite(SB), NOSPLIT, $0-8
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	AX, RARG1
-#else
-	MOVQ	addr+0(FP), RARG1
-#endif
 	MOVQ	(SP), RARG2
 	// void __tsan_write(ThreadState *thr, void *addr, void *pc);
 	MOVQ	$__tsan_write(SB), AX
@@ -130,13 +123,8 @@ TEXT	runtime·racereadrangepc1(SB), NOSPLIT, $0-24
 // Defined as ABIInternal so as to avoid introducing a wrapper,
 // which would render runtime.getcallerpc ineffective.
 TEXT	runtime·racewriterange(SB), NOSPLIT, $0-16
-#ifdef GOEXPERIMENT_regabiargs
 	MOVQ	AX, RARG1
 	MOVQ	BX, RARG2
-#else
-	MOVQ	addr+0(FP), RARG1
-	MOVQ	size+8(FP), RARG2
-#endif
 	MOVQ	(SP), RARG3
 	// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
 	MOVQ	$__tsan_write_range(SB), AX
@@ -160,10 +148,6 @@ TEXT	runtime·racewriterangepc1(SB), NOSPLIT, $0-24
 // If addr (RARG1) is out of range, do nothing.
 // Otherwise, setup goroutine context and invoke racecall. Other arguments already set.
 TEXT	racecalladdr<>(SB), NOSPLIT, $0-0
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_racectx(R14), RARG0	// goroutine context
 	// Check that addr is within [arenastart, arenaend) or within [racedatastart, racedataend).
 	CMPQ	RARG1, runtime·racearenastart(SB)
@@ -191,10 +175,6 @@ TEXT	runtime·racefuncenter(SB), NOSPLIT, $0-8
 // R11 = caller's return address
 TEXT	racefuncenter<>(SB), NOSPLIT, $0-0
 	MOVQ	DX, BX		// save function entry context (for closures)
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_racectx(R14), RARG0	// goroutine context
 	MOVQ	R11, RARG1
 	// void __tsan_func_enter(ThreadState *thr, void *pc);
@@ -207,10 +187,6 @@ TEXT	racefuncenter<>(SB), NOSPLIT, $0-0
 // func runtime·racefuncexit()
 // Called from instrumented code.
 TEXT	runtime·racefuncexit(SB), NOSPLIT, $0-0
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_racectx(R14), RARG0	// goroutine context
 	// void __tsan_func_exit(ThreadState *thr);
 	MOVQ	$__tsan_func_exit(SB), AX
@@ -369,10 +345,6 @@ racecallatomic_data:
 	JAE	racecallatomic_ignore
 racecallatomic_ok:
 	// Addr is within the good range, call the atomic function.
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_racectx(R14), RARG0	// goroutine context
 	MOVQ	8(SP), RARG1	// caller pc
 	MOVQ	(SP), RARG2	// pc
@@ -384,10 +356,6 @@ racecallatomic_ignore:
 	// An attempt to synchronize on the address would cause crash.
 	MOVQ	AX, BX	// remember the original function
 	MOVQ	$__tsan_go_ignore_sync_begin(SB), AX
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_racectx(R14), RARG0	// goroutine context
 	CALL	racecall<>(SB)
 	MOVQ	BX, AX	// restore the original function
@@ -415,10 +383,6 @@ TEXT	runtime·racecall(SB), NOSPLIT, $0-0
 
 // Switches SP to g0 stack and calls (AX). Arguments already set.
 TEXT	racecall<>(SB), NOSPLIT, $0-0
-#ifndef GOEXPERIMENT_regabig
-	get_tls(R12)
-	MOVQ	g(R12), R14
-#endif
 	MOVQ	g_m(R14), R13
 	// Switch to g0 stack.
 	MOVQ	SP, R12		// callee-saved, preserved across the CALL
@@ -440,9 +404,7 @@ call:
 // The overall effect of Go->C->Go call chain is similar to that of mcall.
 // RARG0 contains command code. RARG1 contains command-specific context.
 // See racecallback for command codes.
-// Defined as ABIInternal so as to avoid introducing a wrapper,
-// because its address is passed to C via funcPC.
-TEXT	runtime·racecallbackthunk(SB), NOSPLIT, $0-0
+TEXT	runtime·racecallbackthunk(SB), NOSPLIT, $0-0
 	// Handle command raceGetProcCmd (0) here.
 	// First, code below assumes that we are on curg, while raceGetProcCmd
 	// can be executed on g0. Second, it is called frequently, so will
diff --git a/src/runtime/race_arm64.s b/src/runtime/race_arm64.s
index 82e3caadc8f..2b2413b6b77 100644
--- a/src/runtime/race_arm64.s
+++ b/src/runtime/race_arm64.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build race
 // +build race
 
 #include "go_asm.h"
@@ -42,8 +43,14 @@
 
 // func runtime·raceread(addr uintptr)
 // Called from instrumented code.
-TEXT	runtime·raceread(SB), NOSPLIT, $0-8
+// Defined as ABIInternal so as to avoid introducing a wrapper,
+// which would make caller's PC ineffective.
+TEXT	runtime·raceread(SB), NOSPLIT, $0-8
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R0, R1	// addr
+#else
 	MOVD	addr+0(FP), R1
+#endif
 	MOVD	LR, R2
 	// void __tsan_read(ThreadState *thr, void *addr, void *pc);
 	MOVD	$__tsan_read(SB), R9
@@ -65,8 +72,14 @@ TEXT	runtime·racereadpc(SB), NOSPLIT, $0-24
 
 // func runtime·racewrite(addr uintptr)
 // Called from instrumented code.
-TEXT	runtime·racewrite(SB), NOSPLIT, $0-8
+// Defined as ABIInternal so as to avoid introducing a wrapper,
+// which would make caller's PC ineffective.
+TEXT	runtime·racewrite(SB), NOSPLIT, $0-8
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R0, R1	// addr
+#else
 	MOVD	addr+0(FP), R1
+#endif
 	MOVD	LR, R2
 	// void __tsan_write(ThreadState *thr, void *addr, void *pc);
 	MOVD	$__tsan_write(SB), R9
@@ -88,9 +101,16 @@ TEXT	runtime·racewritepc(SB), NOSPLIT, $0-24
 
 // func runtime·racereadrange(addr, size uintptr)
 // Called from instrumented code.
-TEXT	runtime·racereadrange(SB), NOSPLIT, $0-16
+// Defined as ABIInternal so as to avoid introducing a wrapper,
+// which would make caller's PC ineffective.
+TEXT	runtime·racereadrange(SB), NOSPLIT, $0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R2	// size
+	MOVD	R0, R1	// addr
+#else
 	MOVD	addr+0(FP), R1
 	MOVD	size+8(FP), R2
+#endif
 	MOVD	LR, R3
 	// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
 	MOVD	$__tsan_read_range(SB), R9
@@ -113,9 +133,16 @@ TEXT	runtime·racereadrangepc1(SB), NOSPLIT, $0-24
 
 // func runtime·racewriterange(addr, size uintptr)
 // Called from instrumented code.
-TEXT	runtime·racewriterange(SB), NOSPLIT, $0-16
+// Defined as ABIInternal so as to avoid introducing a wrapper,
+// which would make caller's PC ineffective.
+TEXT	runtime·racewriterange(SB), NOSPLIT, $0-16
+#ifdef GOEXPERIMENT_regabiargs
+	MOVD	R1, R2	// size
+	MOVD	R0, R1	// addr
+#else
 	MOVD	addr+0(FP), R1
 	MOVD	size+8(FP), R2
+#endif
 	MOVD	LR, R3
 	// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
 	MOVD	$__tsan_write_range(SB), R9
diff --git a/src/runtime/race_ppc64le.s b/src/runtime/race_ppc64le.s
index 069e4d86dd4..963e57099c9 100644
--- a/src/runtime/race_ppc64le.s
+++ b/src/runtime/race_ppc64le.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build race
 // +build race
 
 #include "go_asm.h"
diff --git a/src/runtime/rt0_linux_mips64x.s b/src/runtime/rt0_linux_mips64x.s
index 55506755df2..fabd8570b57 100644
--- a/src/runtime/rt0_linux_mips64x.s
+++ b/src/runtime/rt0_linux_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (mips64 || mips64le)
 // +build linux
 // +build mips64 mips64le
 
diff --git a/src/runtime/rt0_linux_mipsx.s b/src/runtime/rt0_linux_mipsx.s
index 74b8f50b73f..9f5842b51a2 100644
--- a/src/runtime/rt0_linux_mipsx.s
+++ b/src/runtime/rt0_linux_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (mips || mipsle)
 // +build linux
 // +build mips mipsle
 
diff --git a/src/runtime/runtime1.go b/src/runtime/runtime1.go
index b238da8f514..b6c3cbfff48 100644
--- a/src/runtime/runtime1.go
+++ b/src/runtime/runtime1.go
@@ -6,8 +6,8 @@ package runtime
 
 import (
 	"internal/bytealg"
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -55,7 +55,7 @@ var (
 // nosplit for use in linux startup sysargs
 //go:nosplit
 func argv_index(argv **byte, i int32) *byte {
-	return *(**byte)(add(unsafe.Pointer(argv), uintptr(i)*sys.PtrSize))
+	return *(**byte)(add(unsafe.Pointer(argv), uintptr(i)*goarch.PtrSize))
 }
 
 func args(c int32, v **byte) {
@@ -190,10 +190,10 @@ func check() {
 	if unsafe.Sizeof(j) != 8 {
 		throw("bad j")
 	}
-	if unsafe.Sizeof(k) != sys.PtrSize {
+	if unsafe.Sizeof(k) != goarch.PtrSize {
 		throw("bad k")
 	}
-	if unsafe.Sizeof(l) != sys.PtrSize {
+	if unsafe.Sizeof(l) != goarch.PtrSize {
 		throw("bad l")
 	}
 	if unsafe.Sizeof(x1) != 1 {
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 0e0eb0b7285..e4e9ee50b80 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -5,8 +5,8 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -505,7 +505,7 @@ const (
 	// tlsSlots is the number of pointer-sized slots reserved for TLS on some platforms,
 	// like Windows.
 	tlsSlots = 6
-	tlsSize  = tlsSlots * sys.PtrSize
+	tlsSize  = tlsSlots * goarch.PtrSize
 )
 
 type m struct {
@@ -613,8 +613,8 @@ type p struct {
 	pcache      pageCache
 	raceprocctx uintptr
 
-	deferpool    [5][]*_defer // pool of available defer structs of different sizes (see panic.go)
-	deferpoolbuf [5][32]*_defer
+	deferpool    []*_defer // pool of available defer structs (see panic.go)
+	deferpoolbuf [32]*_defer
 
 	// Cache of goroutine ids, amortizes accesses to runtime·sched.goidgen.
 	goidcache    uint64
@@ -681,7 +681,7 @@ type p struct {
 	// timerModifiedEarlier status. Because the timer may have been
 	// modified again, there need not be any timer with this value.
 	// This is updated using atomic functions.
-	// This is 0 if the value is unknown.
+	// This is 0 if there are no timerModifiedEarlier timers.
 	timerModifiedEarliest uint64
 
 	// Per-P GC state
@@ -727,12 +727,6 @@ type p struct {
 	// Modified using atomic instructions.
 	numTimers uint32
 
-	// Number of timerModifiedEarlier timers on P's heap.
-	// This should only be modified while holding timersLock,
-	// or while the timer status is in a transient state
-	// such as timerModifying.
-	adjustTimers uint32
-
 	// Number of timerDeleted timers in P's heap.
 	// Modified using atomic instructions.
 	deletedTimers uint32
@@ -801,9 +795,9 @@ type schedt struct {
 	sudoglock  mutex
 	sudogcache *sudog
 
-	// Central pool of available defer structs of different sizes.
+	// Central pool of available defer structs.
 	deferlock mutex
-	deferpool [5]*_defer
+	deferpool *_defer
 
 	// freem is the list of m's waiting to be freed when their
 	// m.exited is set. Linked through m.freelink.
@@ -895,7 +889,7 @@ type funcinl struct {
 // layout of Itab known to compilers
 // allocated in non-garbage-collected memory
 // Needs to be in sync with
-// ../cmd/compile/internal/gc/reflect.go:/^func.WriteTabs.
+// ../cmd/compile/internal/reflectdata/reflect.go:/^func.WriteTabs.
 type itab struct {
 	inter *interfacetype
 	_type *_type
@@ -930,7 +924,7 @@ func extendRandom(r []byte, n int) {
 			w = 16
 		}
 		h := memhash(unsafe.Pointer(&r[n-w]), uintptr(nanotime()), uintptr(w))
-		for i := 0; i < sys.PtrSize && n < len(r); i++ {
+		for i := 0; i < goarch.PtrSize && n < len(r); i++ {
 			r[n] = byte(h)
 			n++
 			h >>= 8
@@ -940,25 +934,24 @@ func extendRandom(r []byte, n int) {
 
 // A _defer holds an entry on the list of deferred calls.
 // If you add a field here, add code to clear it in freedefer and deferProcStack
-// This struct must match the code in cmd/compile/internal/gc/reflect.go:deferstruct
-// and cmd/compile/internal/gc/ssa.go:(*state).call.
+// This struct must match the code in cmd/compile/internal/ssagen/ssa.go:deferstruct
+// and cmd/compile/internal/ssagen/ssa.go:(*state).call.
 // Some defers will be allocated on the stack and some on the heap.
 // All defers are logically part of the stack, so write barriers to
 // initialize them are not required. All defers must be manually scanned,
 // and for heap defers, marked.
 type _defer struct {
-	siz     int32 // includes both arguments and results
 	started bool
 	heap    bool
 	// openDefer indicates that this _defer is for a frame with open-coded
 	// defers. We have only one defer record for the entire frame (which may
 	// currently have 0, 1, or more defers active).
 	openDefer bool
-	sp        uintptr  // sp at time of defer
-	pc        uintptr  // pc at time of defer
-	fn        *funcval // can be nil for open-coded defers
-	_panic    *_panic  // panic that is running defer
-	link      *_defer
+	sp        uintptr // sp at time of defer
+	pc        uintptr // pc at time of defer
+	fn        func()  // can be nil for open-coded defers
+	_panic    *_panic // panic that is running defer
+	link      *_defer // next defer on G; can point to either heap or stack!
 
 	// If openDefer is true, the fields below record values about the stack
 	// frame and associated function that has the open-coded defer(s). sp
diff --git a/src/runtime/select.go b/src/runtime/select.go
index e72761bfa91..ee1f95ffa9e 100644
--- a/src/runtime/select.go
+++ b/src/runtime/select.go
@@ -7,6 +7,7 @@ package runtime
 // This file contains the implementation of Go select statements.
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"unsafe"
 )
@@ -15,15 +16,15 @@ const debugSelect = false
 
 // Select case descriptor.
 // Known to compiler.
-// Changes here must also be made in src/cmd/internal/gc/select.go's scasetype.
+// Changes here must also be made in src/cmd/compile/internal/walk/select.go's scasetype.
 type scase struct {
 	c    *hchan         // chan
 	elem unsafe.Pointer // data element
 }
 
 var (
-	chansendpc = funcPC(chansend)
-	chanrecvpc = funcPC(chanrecv)
+	chansendpc = abi.FuncPCABIInternal(chansend)
+	chanrecvpc = abi.FuncPCABIInternal(chanrecv)
 )
 
 func selectsetpc(pc *uintptr) {
diff --git a/src/runtime/sigaction.go b/src/runtime/sigaction.go
index 76f37b1b535..30050efcc78 100644
--- a/src/runtime/sigaction.go
+++ b/src/runtime/sigaction.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && !amd64 && !arm64) || (freebsd && !amd64)
-// +build linux,!amd64,!arm64 freebsd,!amd64
+//go:build (linux && !amd64 && !arm64 && !ppc64le) || (freebsd && !amd64)
+// +build linux,!amd64,!arm64,!ppc64le freebsd,!amd64
 
 package runtime
 
diff --git a/src/runtime/signal_386.go b/src/runtime/signal_386.go
index 5824eaddb56..69a59e6dcff 100644
--- a/src/runtime/signal_386.go
+++ b/src/runtime/signal_386.go
@@ -8,7 +8,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -42,17 +43,17 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	sp := uintptr(c.esp())
 
 	if shouldPushSigpanic(gp, pc, *(*uintptr)(unsafe.Pointer(sp))) {
-		c.pushCall(funcPC(sigpanic), pc)
+		c.pushCall(abi.FuncPCABIInternal(sigpanic), pc)
 	} else {
 		// Not safe to push the call. Just clobber the frame.
-		c.set_eip(uint32(funcPC(sigpanic)))
+		c.set_eip(uint32(abi.FuncPCABIInternal(sigpanic)))
 	}
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
 	// Make it look like we called target at resumePC.
 	sp := uintptr(c.esp())
-	sp -= sys.PtrSize
+	sp -= goarch.PtrSize
 	*(*uintptr)(unsafe.Pointer(sp)) = resumePC
 	c.set_esp(uint32(sp))
 	c.set_eip(uint32(targetPC))
diff --git a/src/runtime/signal_aix_ppc64.go b/src/runtime/signal_aix_ppc64.go
index a0becd431eb..5999d9dc3d0 100644
--- a/src/runtime/signal_aix_ppc64.go
+++ b/src/runtime/signal_aix_ppc64.go
@@ -8,7 +8,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -82,5 +82,5 @@ func (c *sigctxt) set_link(x uint64) { c.regs().lr = x }
 
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_amd64.go b/src/runtime/signal_amd64.go
index e45fbb4a87a..20490cffbf5 100644
--- a/src/runtime/signal_amd64.go
+++ b/src/runtime/signal_amd64.go
@@ -9,7 +9,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -70,17 +71,17 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	// Go special registers. We inject sigpanic0 (instead of sigpanic),
 	// which takes care of that.
 	if shouldPushSigpanic(gp, pc, *(*uintptr)(unsafe.Pointer(sp))) {
-		c.pushCall(funcPC(sigpanic0), pc)
+		c.pushCall(abi.FuncPCABI0(sigpanic0), pc)
 	} else {
 		// Not safe to push the call. Just clobber the frame.
-		c.set_rip(uint64(funcPC(sigpanic0)))
+		c.set_rip(uint64(abi.FuncPCABI0(sigpanic0)))
 	}
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
 	// Make it look like we called target at resumePC.
 	sp := uintptr(c.rsp())
-	sp -= sys.PtrSize
+	sp -= goarch.PtrSize
 	*(*uintptr)(unsafe.Pointer(sp)) = resumePC
 	c.set_rsp(uint64(sp))
 	c.set_rip(uint64(targetPC))
diff --git a/src/runtime/signal_arm.go b/src/runtime/signal_arm.go
index 4d9c6224a29..a0780788f80 100644
--- a/src/runtime/signal_arm.go
+++ b/src/runtime/signal_arm.go
@@ -7,7 +7,10 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 func dumpregs(c *sigctxt) {
 	print("trap    ", hex(c.trap()), "\n")
@@ -61,7 +64,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 
 	// In case we are panicking from external C code
 	c.set_r10(uint32(uintptr(unsafe.Pointer(gp))))
-	c.set_pc(uint32(funcPC(sigpanic)))
+	c.set_pc(uint32(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
diff --git a/src/runtime/signal_arm64.go b/src/runtime/signal_arm64.go
index f04750084f4..9d4a8b8a99d 100644
--- a/src/runtime/signal_arm64.go
+++ b/src/runtime/signal_arm64.go
@@ -8,6 +8,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -77,7 +78,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 
 	// In case we are panicking from external C code
 	c.set_r28(uint64(uintptr(unsafe.Pointer(gp))))
-	c.set_pc(uint64(funcPC(sigpanic)))
+	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
diff --git a/src/runtime/signal_linux_386.go b/src/runtime/signal_linux_386.go
index 13d9df40710..321518c18e3 100644
--- a/src/runtime/signal_linux_386.go
+++ b/src/runtime/signal_linux_386.go
@@ -5,7 +5,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -42,5 +42,5 @@ func (c *sigctxt) set_eip(x uint32)     { c.regs().eip = x }
 func (c *sigctxt) set_esp(x uint32)     { c.regs().esp = x }
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint32) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_amd64.go b/src/runtime/signal_linux_amd64.go
index 210e8967e5d..573b1183974 100644
--- a/src/runtime/signal_linux_amd64.go
+++ b/src/runtime/signal_linux_amd64.go
@@ -5,7 +5,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -52,5 +52,5 @@ func (c *sigctxt) set_rip(x uint64)     { c.regs().rip = x }
 func (c *sigctxt) set_rsp(x uint64)     { c.regs().rsp = x }
 func (c *sigctxt) set_sigcode(x uint64) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_arm.go b/src/runtime/signal_linux_arm.go
index 876b5059173..eb107d68d1b 100644
--- a/src/runtime/signal_linux_arm.go
+++ b/src/runtime/signal_linux_arm.go
@@ -5,7 +5,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -54,5 +54,5 @@ func (c *sigctxt) set_r10(x uint32) { c.regs().r10 = x }
 
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint32) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_arm64.go b/src/runtime/signal_linux_arm64.go
index 2075f253d7d..4ccc0307923 100644
--- a/src/runtime/signal_linux_arm64.go
+++ b/src/runtime/signal_linux_arm64.go
@@ -5,7 +5,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -67,5 +67,5 @@ func (c *sigctxt) set_lr(x uint64)  { c.regs().regs[30] = x }
 func (c *sigctxt) set_r28(x uint64) { c.regs().regs[28] = x }
 
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_mips64x.go b/src/runtime/signal_linux_mips64x.go
index f0a75ac3ea5..e62d6a93fd2 100644
--- a/src/runtime/signal_linux_mips64x.go
+++ b/src/runtime/signal_linux_mips64x.go
@@ -9,7 +9,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -75,5 +75,5 @@ func (c *sigctxt) set_link(x uint64) { c.regs().sc_regs[31] = x }
 
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_ppc64x.go b/src/runtime/signal_linux_ppc64x.go
index d9d3e55ec20..d2eeb39eadd 100644
--- a/src/runtime/signal_linux_ppc64x.go
+++ b/src/runtime/signal_linux_ppc64x.go
@@ -9,7 +9,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -79,5 +79,5 @@ func (c *sigctxt) set_link(x uint64) { c.regs().link = x }
 
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_riscv64.go b/src/runtime/signal_linux_riscv64.go
index 9f68e5c548f..b26450dbfac 100644
--- a/src/runtime/signal_linux_riscv64.go
+++ b/src/runtime/signal_linux_riscv64.go
@@ -5,7 +5,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -64,5 +64,5 @@ func (c *sigctxt) set_gp(x uint64) { c.regs().sc_regs.gp = x }
 
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
diff --git a/src/runtime/signal_linux_s390x.go b/src/runtime/signal_linux_s390x.go
index 12d5c315931..18c3b115efc 100644
--- a/src/runtime/signal_linux_s390x.go
+++ b/src/runtime/signal_linux_s390x.go
@@ -5,6 +5,8 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -53,7 +55,7 @@ func (c *sigctxt) set_sp(x uint64)      { c.regs().gregs[15] = x }
 func (c *sigctxt) set_pc(x uint64)      { c.regs().psw_addr = x }
 func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
 func (c *sigctxt) set_sigaddr(x uint64) {
-	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize)) = uintptr(x)
 }
 
 func dumpregs(c *sigctxt) {
@@ -107,7 +109,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	// In case we are panicking from external C code
 	c.set_r0(0)
 	c.set_r13(uint64(uintptr(unsafe.Pointer(gp))))
-	c.set_pc(uint64(funcPC(sigpanic)))
+	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
diff --git a/src/runtime/signal_mips64x.go b/src/runtime/signal_mips64x.go
index 1616b570278..87dfa724c47 100644
--- a/src/runtime/signal_mips64x.go
+++ b/src/runtime/signal_mips64x.go
@@ -9,7 +9,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -68,7 +69,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	// functions are correctly handled. This smashes
 	// the stack frame but we're not going back there
 	// anyway.
-	sp := c.sp() - sys.PtrSize
+	sp := c.sp() - goarch.PtrSize
 	c.set_sp(sp)
 	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.link()
 
@@ -80,7 +81,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	}
 
 	// In case we are panicking from external C code
-	sigpanicPC := uint64(funcPC(sigpanic))
+	sigpanicPC := uint64(abi.FuncPCABIInternal(sigpanic))
 	c.set_r28(sigpanicPC >> 32 << 32) // RSB register
 	c.set_r30(uint64(uintptr(unsafe.Pointer(gp))))
 	c.set_pc(sigpanicPC)
diff --git a/src/runtime/signal_mipsx.go b/src/runtime/signal_mipsx.go
index dcc7f1e9dd5..5067799bd6b 100644
--- a/src/runtime/signal_mipsx.go
+++ b/src/runtime/signal_mipsx.go
@@ -9,6 +9,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -78,7 +79,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 
 	// In case we are panicking from external C code
 	c.set_r30(uint32(uintptr(unsafe.Pointer(gp))))
-	c.set_pc(uint32(funcPC(sigpanic)))
+	c.set_pc(uint32(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
diff --git a/src/runtime/signal_ppc64x.go b/src/runtime/signal_ppc64x.go
index f2225da9a17..8a39d599576 100644
--- a/src/runtime/signal_ppc64x.go
+++ b/src/runtime/signal_ppc64x.go
@@ -9,6 +9,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -83,8 +84,8 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	// In case we are panicking from external C code
 	c.set_r0(0)
 	c.set_r30(uint64(uintptr(unsafe.Pointer(gp))))
-	c.set_r12(uint64(funcPC(sigpanic)))
-	c.set_pc(uint64(funcPC(sigpanic)))
+	c.set_r12(uint64(abi.FuncPCABIInternal(sigpanic)))
+	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
diff --git a/src/runtime/signal_riscv64.go b/src/runtime/signal_riscv64.go
index e6b1b14130e..8a24e4e36a9 100644
--- a/src/runtime/signal_riscv64.go
+++ b/src/runtime/signal_riscv64.go
@@ -8,7 +8,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -63,7 +64,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 	// functions are correctly handled. This smashes
 	// the stack frame but we're not going back there
 	// anyway.
-	sp := c.sp() - sys.PtrSize
+	sp := c.sp() - goarch.PtrSize
 	c.set_sp(sp)
 	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.ra()
 
@@ -76,7 +77,7 @@ func (c *sigctxt) preparePanic(sig uint32, gp *g) {
 
 	// In case we are panicking from external C code
 	c.set_gp(uint64(uintptr(unsafe.Pointer(gp))))
-	c.set_pc(uint64(funcPC(sigpanic)))
+	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
 }
 
 func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
@@ -84,7 +85,7 @@ func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
 	// push the call. The function being pushed is responsible
 	// for restoring the LR and setting the SP back.
 	// This extra slot is known to gentraceback.
-	sp := c.sp() - sys.PtrSize
+	sp := c.sp() - goarch.PtrSize
 	c.set_sp(sp)
 	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.ra()
 	// Set up PC and LR to pretend the function being signaled
diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go
index f2e526973df..8117582855d 100644
--- a/src/runtime/signal_unix.go
+++ b/src/runtime/signal_unix.go
@@ -8,6 +8,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"unsafe"
 )
@@ -143,7 +144,7 @@ func initsig(preinit bool) {
 		}
 
 		handlingSig[i] = 1
-		setsig(i, funcPC(sighandler))
+		setsig(i, abi.FuncPCABIInternal(sighandler))
 	}
 }
 
@@ -194,7 +195,7 @@ func sigenable(sig uint32) {
 		<-maskUpdatedChan
 		if atomic.Cas(&handlingSig[sig], 0, 1) {
 			atomic.Storeuintptr(&fwdSig[sig], getsig(sig))
-			setsig(sig, funcPC(sighandler))
+			setsig(sig, abi.FuncPCABIInternal(sighandler))
 		}
 	}
 }
@@ -271,7 +272,7 @@ func setProcessCPUProfiler(hz int32) {
 		// Enable the Go signal handler if not enabled.
 		if atomic.Cas(&handlingSig[_SIGPROF], 0, 1) {
 			atomic.Storeuintptr(&fwdSig[_SIGPROF], getsig(_SIGPROF))
-			setsig(_SIGPROF, funcPC(sighandler))
+			setsig(_SIGPROF, abi.FuncPCABIInternal(sighandler))
 		}
 
 		var it itimerval
@@ -280,6 +281,8 @@ func setProcessCPUProfiler(hz int32) {
 		it.it_value = it.it_interval
 		setitimer(_ITIMER_PROF, &it, nil)
 	} else {
+		setitimer(_ITIMER_PROF, &itimerval{}, nil)
+
 		// If the Go signal handler should be disabled by default,
 		// switch back to the signal handler that was installed
 		// when we enabled profiling. We don't try to handle the case
@@ -303,8 +306,6 @@ func setProcessCPUProfiler(hz int32) {
 				setsig(_SIGPROF, h)
 			}
 		}
-
-		setitimer(_ITIMER_PROF, &itimerval{}, nil)
 	}
 }
 
@@ -329,7 +330,7 @@ func doSigPreempt(gp *g, ctxt *sigctxt) {
 	if wantAsyncPreempt(gp) {
 		if ok, newpc := isAsyncSafePoint(gp, ctxt.sigpc(), ctxt.sigsp(), ctxt.siglr()); ok {
 			// Adjust the PC and inject a call to asyncPreempt.
-			ctxt.pushCall(funcPC(asyncPreempt), newpc)
+			ctxt.pushCall(abi.FuncPCABI0(asyncPreempt), newpc)
 		}
 	}
 
@@ -382,7 +383,7 @@ func preemptM(mp *m) {
 //go:nosplit
 func sigFetchG(c *sigctxt) *g {
 	switch GOARCH {
-	case "arm", "arm64":
+	case "arm", "arm64", "ppc64", "ppc64le":
 		if !iscgo && inVDSOPage(c.sigpc()) {
 			// When using cgo, we save the g on TLS and load it from there
 			// in sigtramp. Just use that.
@@ -843,7 +844,7 @@ func raisebadsignal(sig uint32, c *sigctxt) {
 	// We may receive another instance of the signal before we
 	// restore the Go handler, but that is not so bad: we know
 	// that the Go program has been ignoring the signal.
-	setsig(sig, funcPC(sighandler))
+	setsig(sig, abi.FuncPCABIInternal(sighandler))
 }
 
 //go:nosplit
diff --git a/src/runtime/signal_windows.go b/src/runtime/signal_windows.go
index f2ce24d735c..3fe352ef575 100644
--- a/src/runtime/signal_windows.go
+++ b/src/runtime/signal_windows.go
@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -27,15 +28,15 @@ func firstcontinuetramp()
 func lastcontinuetramp()
 
 func initExceptionHandler() {
-	stdcall2(_AddVectoredExceptionHandler, 1, funcPC(exceptiontramp))
+	stdcall2(_AddVectoredExceptionHandler, 1, abi.FuncPCABI0(exceptiontramp))
 	if _AddVectoredContinueHandler == nil || GOARCH == "386" {
 		// use SetUnhandledExceptionFilter for windows-386 or
 		// if VectoredContinueHandler is unavailable.
 		// note: SetUnhandledExceptionFilter handler won't be called, if debugging.
-		stdcall1(_SetUnhandledExceptionFilter, funcPC(lastcontinuetramp))
+		stdcall1(_SetUnhandledExceptionFilter, abi.FuncPCABI0(lastcontinuetramp))
 	} else {
-		stdcall2(_AddVectoredContinueHandler, 1, funcPC(firstcontinuetramp))
-		stdcall2(_AddVectoredContinueHandler, 0, funcPC(lastcontinuetramp))
+		stdcall2(_AddVectoredContinueHandler, 1, abi.FuncPCABI0(firstcontinuetramp))
+		stdcall2(_AddVectoredContinueHandler, 0, abi.FuncPCABI0(lastcontinuetramp))
 	}
 }
 
@@ -133,7 +134,7 @@ func exceptionhandler(info *exceptionrecord, r *context, gp *g) int32 {
 	// The exception is not from asyncPreempt, so not to push a
 	// sigpanic call to make it look like that. Instead, just
 	// overwrite the PC. (See issue #35773)
-	if r.ip() != 0 && r.ip() != funcPC(asyncPreempt) {
+	if r.ip() != 0 && r.ip() != abi.FuncPCABI0(asyncPreempt) {
 		sp := unsafe.Pointer(r.sp())
 		delta := uintptr(sys.StackAlign)
 		sp = add(sp, -delta)
@@ -145,7 +146,7 @@ func exceptionhandler(info *exceptionrecord, r *context, gp *g) int32 {
 			*((*uintptr)(sp)) = r.ip()
 		}
 	}
-	r.set_ip(funcPC(sigpanic0))
+	r.set_ip(abi.FuncPCABI0(sigpanic0))
 	return _EXCEPTION_CONTINUE_EXECUTION
 }
 
@@ -183,6 +184,17 @@ func lastcontinuehandler(info *exceptionrecord, r *context, gp *g) int32 {
 		return _EXCEPTION_CONTINUE_SEARCH
 	}
 
+	// VEH is called before SEH, but arm64 MSVC DLLs use SEH to trap
+	// illegal instructions during runtime initialization to determine
+	// CPU features, so if we make it to the last handler and we're
+	// arm64 and it's an illegal instruction and this is coming from
+	// non-Go code, then assume it's this runtime probing happen, and
+	// pass that onward to SEH.
+	if GOARCH == "arm64" && info.exceptioncode == _EXCEPTION_ILLEGAL_INSTRUCTION &&
+		(r.ip() < firstmoduledata.text || firstmoduledata.etext < r.ip()) {
+		return _EXCEPTION_CONTINUE_SEARCH
+	}
+
 	winthrow(info, r, gp)
 	return 0 // not reached
 }
diff --git a/src/runtime/slice.go b/src/runtime/slice.go
index f9d4154acfd..e8267be885d 100644
--- a/src/runtime/slice.go
+++ b/src/runtime/slice.go
@@ -5,6 +5,8 @@
 package runtime
 
 import (
+	"internal/abi"
+	"internal/goarch"
 	"runtime/internal/math"
 	"runtime/internal/sys"
 	"unsafe"
@@ -68,7 +70,7 @@ func makeslicecopy(et *_type, tolen int, fromlen int, from unsafe.Pointer) unsaf
 
 	if raceenabled {
 		callerpc := getcallerpc()
-		pc := funcPC(makeslicecopy)
+		pc := abi.FuncPCABIInternal(makeslicecopy)
 		racereadrangepc(from, copymem, callerpc, pc)
 	}
 	if msanenabled {
@@ -112,19 +114,37 @@ func makeslice64(et *_type, len64, cap64 int64) unsafe.Pointer {
 	return makeslice(et, len, cap)
 }
 
-func unsafeslice(et *_type, len int) {
+func unsafeslice(et *_type, ptr unsafe.Pointer, len int) {
+	if len == 0 {
+		return
+	}
+
+	if ptr == nil {
+		panic(errorString("unsafe.Slice: ptr is nil and len is not zero"))
+	}
+
 	mem, overflow := math.MulUintptr(et.size, uintptr(len))
 	if overflow || mem > maxAlloc || len < 0 {
 		panicunsafeslicelen()
 	}
 }
 
-func unsafeslice64(et *_type, len64 int64) {
+func unsafeslice64(et *_type, ptr unsafe.Pointer, len64 int64) {
 	len := int(len64)
 	if int64(len) != len64 {
 		panicunsafeslicelen()
 	}
-	unsafeslice(et, len)
+	unsafeslice(et, ptr, len)
+}
+
+func unsafeslicecheckptr(et *_type, ptr unsafe.Pointer, len64 int64) {
+	unsafeslice64(et, ptr, len64)
+
+	// Check that underlying array doesn't straddle multiple heap objects.
+	// unsafeslice64 has already checked for overflow.
+	if checkptrStraddles(ptr, uintptr(len64)*et.size) {
+		throw("checkptr: unsafe.Slice result straddles multiple allocations")
+	}
 }
 
 func panicunsafeslicelen() {
@@ -144,7 +164,7 @@ func panicunsafeslicelen() {
 func growslice(et *_type, old slice, cap int) slice {
 	if raceenabled {
 		callerpc := getcallerpc()
-		racereadrangepc(old.array, uintptr(old.len*int(et.size)), callerpc, funcPC(growslice))
+		racereadrangepc(old.array, uintptr(old.len*int(et.size)), callerpc, abi.FuncPCABIInternal(growslice))
 	}
 	if msanenabled {
 		msanread(old.array, uintptr(old.len*int(et.size)))
@@ -194,15 +214,15 @@ func growslice(et *_type, old slice, cap int) slice {
 		capmem = roundupsize(uintptr(newcap))
 		overflow = uintptr(newcap) > maxAlloc
 		newcap = int(capmem)
-	case et.size == sys.PtrSize:
-		lenmem = uintptr(old.len) * sys.PtrSize
-		newlenmem = uintptr(cap) * sys.PtrSize
-		capmem = roundupsize(uintptr(newcap) * sys.PtrSize)
-		overflow = uintptr(newcap) > maxAlloc/sys.PtrSize
-		newcap = int(capmem / sys.PtrSize)
+	case et.size == goarch.PtrSize:
+		lenmem = uintptr(old.len) * goarch.PtrSize
+		newlenmem = uintptr(cap) * goarch.PtrSize
+		capmem = roundupsize(uintptr(newcap) * goarch.PtrSize)
+		overflow = uintptr(newcap) > maxAlloc/goarch.PtrSize
+		newcap = int(capmem / goarch.PtrSize)
 	case isPowerOfTwo(et.size):
 		var shift uintptr
-		if sys.PtrSize == 8 {
+		if goarch.PtrSize == 8 {
 			// Mask shift for better code generation.
 			shift = uintptr(sys.Ctz64(uint64(et.size))) & 63
 		} else {
@@ -280,7 +300,7 @@ func slicecopy(toPtr unsafe.Pointer, toLen int, fromPtr unsafe.Pointer, fromLen
 	size := uintptr(n) * width
 	if raceenabled {
 		callerpc := getcallerpc()
-		pc := funcPC(slicecopy)
+		pc := abi.FuncPCABIInternal(slicecopy)
 		racereadrangepc(fromPtr, size, callerpc, pc)
 		racewriterangepc(toPtr, size, callerpc, pc)
 	}
diff --git a/src/runtime/softfloat64.go b/src/runtime/softfloat64.go
index 13bee6c1d7a..084aa132d9c 100644
--- a/src/runtime/softfloat64.go
+++ b/src/runtime/softfloat64.go
@@ -562,36 +562,38 @@ func f64toint64(x uint64) int64 {
 	return val
 }
 
-func f64touint64(x float64) uint64 {
-	if x < float64(1<<63) {
-		return uint64(int64(x))
+func f64touint64(x uint64) uint64 {
+	var m uint64 = 0x43e0000000000000 // float64 1<<63
+	if fgt64(m, x) {
+		return uint64(f64toint64(x))
 	}
-	y := x - float64(1<<63)
-	z := uint64(int64(y))
+	y := fadd64(x, -m)
+	z := uint64(f64toint64(y))
 	return z | (1 << 63)
 }
 
-func f32touint64(x float32) uint64 {
-	if x < float32(1<<63) {
-		return uint64(int64(x))
+func f32touint64(x uint32) uint64 {
+	var m uint32 = 0x5f000000 // float32 1<<63
+	if fgt32(m, x) {
+		return uint64(f32toint64(x))
 	}
-	y := x - float32(1<<63)
-	z := uint64(int64(y))
+	y := fadd32(x, -m)
+	z := uint64(f32toint64(y))
 	return z | (1 << 63)
 }
 
-func fuint64to64(x uint64) float64 {
+func fuint64to64(x uint64) uint64 {
 	if int64(x) >= 0 {
-		return float64(int64(x))
+		return fint64to64(int64(x))
 	}
-	// See ../cmd/compile/internal/gc/ssa.go:uint64Tofloat
+	// See ../cmd/compile/internal/ssagen/ssa.go:uint64Tofloat
 	y := x & 1
 	z := x >> 1
 	z = z | y
-	r := float64(int64(z))
-	return r + r
+	r := fint64to64(int64(z))
+	return fadd64(r, r)
 }
 
-func fuint64to32(x uint64) float32 {
-	return float32(fuint64to64(x))
+func fuint64to32(x uint64) uint32 {
+	return f64to32(fuint64to64(x))
 }
diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index b21c9c95182..54ad66dca2d 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -7,6 +7,8 @@ package runtime
 import (
 	"internal/abi"
 	"internal/cpu"
+	"internal/goarch"
+	"internal/goos"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -67,7 +69,7 @@ const (
 	// to each stack below the usual guard area for OS-specific
 	// purposes like signal handling. Used on Windows, Plan 9,
 	// and iOS because they do not use a separate stack.
-	_StackSystem = sys.GoosWindows*512*sys.PtrSize + sys.GoosPlan9*512 + sys.GoosIos*sys.GoarchArm64*1024
+	_StackSystem = goos.IsWindows*512*goarch.PtrSize + goos.IsPlan9*512 + goos.IsIos*goarch.IsArm64*1024
 
 	// The minimum size of stack used by Go code
 	_StackMin = 2048
@@ -125,7 +127,7 @@ const (
 )
 
 const (
-	uintptrMask = 1<<(8*sys.PtrSize) - 1
+	uintptrMask = 1<<(8*goarch.PtrSize) - 1
 
 	// The values below can be stored to g.stackguard0 to force
 	// the next stack check to fail.
@@ -599,14 +601,14 @@ func adjustpointers(scanp unsafe.Pointer, bv *bitvector, adjinfo *adjustinfo, f
 	for i := uintptr(0); i < num; i += 8 {
 		if stackDebug >= 4 {
 			for j := uintptr(0); j < 8; j++ {
-				print("        ", add(scanp, (i+j)*sys.PtrSize), ":", ptrnames[bv.ptrbit(i+j)], ":", hex(*(*uintptr)(add(scanp, (i+j)*sys.PtrSize))), " # ", i, " ", *addb(bv.bytedata, i/8), "\n")
+				print("        ", add(scanp, (i+j)*goarch.PtrSize), ":", ptrnames[bv.ptrbit(i+j)], ":", hex(*(*uintptr)(add(scanp, (i+j)*goarch.PtrSize))), " # ", i, " ", *addb(bv.bytedata, i/8), "\n")
 			}
 		}
 		b := *(addb(bv.bytedata, i/8))
 		for b != 0 {
 			j := uintptr(sys.Ctz8(b))
 			b &= b - 1
-			pp := (*uintptr)(add(scanp, (i+j)*sys.PtrSize))
+			pp := (*uintptr)(add(scanp, (i+j)*goarch.PtrSize))
 		retry:
 			p := *pp
 			if f.valid() && 0 < p && p < minLegalPointer && debug.invalidptr != 0 {
@@ -655,13 +657,13 @@ func adjustframe(frame *stkframe, arg unsafe.Pointer) bool {
 
 	// Adjust local variables if stack frame has been allocated.
 	if locals.n > 0 {
-		size := uintptr(locals.n) * sys.PtrSize
+		size := uintptr(locals.n) * goarch.PtrSize
 		adjustpointers(unsafe.Pointer(frame.varp-size), &locals, adjinfo, f)
 	}
 
 	// Adjust saved base pointer if there is one.
 	// TODO what about arm64 frame pointer adjustment?
-	if sys.ArchFamily == sys.AMD64 && frame.argp-frame.varp == 2*sys.PtrSize {
+	if goarch.ArchFamily == goarch.AMD64 && frame.argp-frame.varp == 2*goarch.PtrSize {
 		if stackDebug >= 3 {
 			print("      saved bp\n")
 		}
@@ -710,8 +712,8 @@ func adjustframe(frame *stkframe, arg unsafe.Pointer) bool {
 				s = materializeGCProg(ptrdata, gcdata)
 				gcdata = (*byte)(unsafe.Pointer(s.startAddr))
 			}
-			for i := uintptr(0); i < ptrdata; i += sys.PtrSize {
-				if *addb(gcdata, i/(8*sys.PtrSize))>>(i/sys.PtrSize&7)&1 != 0 {
+			for i := uintptr(0); i < ptrdata; i += goarch.PtrSize {
+				if *addb(gcdata, i/(8*goarch.PtrSize))>>(i/goarch.PtrSize&7)&1 != 0 {
 					adjustpointer(adjinfo, unsafe.Pointer(p+i))
 				}
 			}
@@ -753,11 +755,6 @@ func adjustdefers(gp *g, adjinfo *adjustinfo) {
 		adjustpointer(adjinfo, unsafe.Pointer(&d.varp))
 		adjustpointer(adjinfo, unsafe.Pointer(&d.fd))
 	}
-
-	// Adjust defer argument blocks the same way we adjust active stack frames.
-	// Note: this code is after the loop above, so that if a defer record is
-	// stack allocated, we work on the copy in the new stack.
-	tracebackdefers(gp, adjustframe, noescape(unsafe.Pointer(adjinfo)))
 }
 
 func adjustpanics(gp *g, adjinfo *adjustinfo) {
@@ -1017,9 +1014,9 @@ func newstack() {
 		throw("missing stack in newstack")
 	}
 	sp := gp.sched.sp
-	if sys.ArchFamily == sys.AMD64 || sys.ArchFamily == sys.I386 || sys.ArchFamily == sys.WASM {
+	if goarch.ArchFamily == goarch.AMD64 || goarch.ArchFamily == goarch.I386 || goarch.ArchFamily == goarch.WASM {
 		// The call to morestack cost a word.
-		sp -= sys.PtrSize
+		sp -= goarch.PtrSize
 	}
 	if stackDebug >= 1 || sp < gp.stack.lo {
 		print("runtime: newstack sp=", hex(sp), " stack=[", hex(gp.stack.lo), ", ", hex(gp.stack.hi), "]\n",
@@ -1064,7 +1061,9 @@ func newstack() {
 	// recheck the bounds on return.)
 	if f := findfunc(gp.sched.pc); f.valid() {
 		max := uintptr(funcMaxSPDelta(f))
-		for newsize-gp.sched.sp < max+_StackGuard {
+		needed := max + _StackGuard
+		used := gp.stack.hi - gp.sched.sp
+		for newsize-used < needed {
 			newsize *= 2
 		}
 	}
@@ -1112,7 +1111,7 @@ func gostartcallfn(gobuf *gobuf, fv *funcval) {
 	if fv != nil {
 		fn = unsafe.Pointer(fv.fn)
 	} else {
-		fn = unsafe.Pointer(funcPC(nilfunc))
+		fn = unsafe.Pointer(abi.FuncPCABIInternal(nilfunc))
 	}
 	gostartcall(gobuf, fn, unsafe.Pointer(fv))
 }
@@ -1260,8 +1259,8 @@ func getStackMap(frame *stkframe, cache *pcvalueCache, debug bool) (locals, args
 	// Local variables.
 	size := frame.varp - frame.sp
 	var minsize uintptr
-	switch sys.ArchFamily {
-	case sys.ARM64:
+	switch goarch.ArchFamily {
+	case goarch.ARM64:
 		minsize = sys.StackAlign
 	default:
 		minsize = sys.MinFrameSize
@@ -1296,7 +1295,7 @@ func getStackMap(frame *stkframe, cache *pcvalueCache, debug bool) (locals, args
 			// In this case, arglen specifies how much of the args section is actually live.
 			// (It could be either all the args + results, or just the args.)
 			args = *frame.argmap
-			n := int32(frame.arglen / sys.PtrSize)
+			n := int32(frame.arglen / goarch.PtrSize)
 			if n < args.n {
 				args.n = n // Don't use more of the arguments than arglen.
 			}
@@ -1318,17 +1317,17 @@ func getStackMap(frame *stkframe, cache *pcvalueCache, debug bool) (locals, args
 	}
 
 	// stack objects.
-	if GOARCH == "amd64" && unsafe.Sizeof(abi.RegArgs{}) > 0 && frame.argmap != nil {
+	if (GOARCH == "amd64" || GOARCH == "arm64") && unsafe.Sizeof(abi.RegArgs{}) > 0 && frame.argmap != nil {
 		// argmap is set when the function is reflect.makeFuncStub or reflect.methodValueCall.
 		// We don't actually use argmap in this case, but we need to fake the stack object
-		// record for these frames which contain an internal/abi.RegArgs at a hard-coded offset
-		// on amd64.
+		// record for these frames which contain an internal/abi.RegArgs at a hard-coded offset.
+		// This offset matches the assembly code on amd64 and arm64.
 		objs = methodValueCallFrameObjs
 	} else {
 		p := funcdata(f, _FUNCDATA_StackObjects)
 		if p != nil {
 			n := *(*uintptr)(p)
-			p = add(p, sys.PtrSize)
+			p = add(p, goarch.PtrSize)
 			*(*slice)(unsafe.Pointer(&objs)) = slice{array: noescape(p), len: int(n), cap: int(n)}
 			// Note: the noescape above is needed to keep
 			// getStackMap from "leaking param content:
diff --git a/src/runtime/string.go b/src/runtime/string.go
index d6030a1dca4..d6990dab9aa 100644
--- a/src/runtime/string.go
+++ b/src/runtime/string.go
@@ -5,8 +5,9 @@
 package runtime
 
 import (
+	"internal/abi"
 	"internal/bytealg"
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -88,14 +89,14 @@ func slicebytetostring(buf *tmpBuf, ptr *byte, n int) (str string) {
 		racereadrangepc(unsafe.Pointer(ptr),
 			uintptr(n),
 			getcallerpc(),
-			funcPC(slicebytetostring))
+			abi.FuncPCABIInternal(slicebytetostring))
 	}
 	if msanenabled {
 		msanread(unsafe.Pointer(ptr), uintptr(n))
 	}
 	if n == 1 {
 		p := unsafe.Pointer(&staticuint64s[*ptr])
-		if sys.BigEndian {
+		if goarch.BigEndian {
 			p = add(p, 7)
 		}
 		stringStructOf(&str).str = p
@@ -152,7 +153,7 @@ func slicebytetostringtmp(ptr *byte, n int) (str string) {
 		racereadrangepc(unsafe.Pointer(ptr),
 			uintptr(n),
 			getcallerpc(),
-			funcPC(slicebytetostringtmp))
+			abi.FuncPCABIInternal(slicebytetostringtmp))
 	}
 	if msanenabled && n > 0 {
 		msanread(unsafe.Pointer(ptr), uintptr(n))
@@ -203,7 +204,7 @@ func slicerunetostring(buf *tmpBuf, a []rune) string {
 		racereadrangepc(unsafe.Pointer(&a[0]),
 			uintptr(len(a))*unsafe.Sizeof(a[0]),
 			getcallerpc(),
-			funcPC(slicerunetostring))
+			abi.FuncPCABIInternal(slicerunetostring))
 	}
 	if msanenabled && len(a) > 0 {
 		msanread(unsafe.Pointer(&a[0]), uintptr(len(a))*unsafe.Sizeof(a[0]))
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go
index 16d75832029..8a520d7839e 100644
--- a/src/runtime/stubs.go
+++ b/src/runtime/stubs.go
@@ -6,6 +6,7 @@ package runtime
 
 import (
 	"internal/abi"
+	"internal/goarch"
 	"internal/goexperiment"
 	"unsafe"
 )
@@ -176,8 +177,6 @@ func cgocallback(fn, frame, ctxt uintptr)
 
 func gogo(buf *gobuf)
 
-//go:noescape
-func jmpdefer(fv *funcval, argp uintptr)
 func asminit()
 func setg(gg *g)
 func breakpoint()
@@ -421,12 +420,5 @@ func sigpanic0()
 // structure that is at least large enough to hold the
 // registers the system supports.
 //
-// Currently it's set to zero because using the actual
-// constant will break every part of the toolchain that
-// uses finalizers or Windows callbacks to call functions
-// The value that is currently commented out there should be
-// the actual value once we're ready to use the register ABI
-// everywhere.
-//
 // Protected by finlock.
-var intArgRegs = abi.IntArgRegs * goexperiment.RegabiArgsInt
+var intArgRegs = abi.IntArgRegs * (goexperiment.RegabiArgsInt | goarch.IsAmd64)
diff --git a/src/runtime/stubs_arm64.go b/src/runtime/stubs_arm64.go
index f5e3bb48540..bd0533d1581 100644
--- a/src/runtime/stubs_arm64.go
+++ b/src/runtime/stubs_arm64.go
@@ -14,3 +14,10 @@ func save_g()
 func asmcgocall_no_g(fn, arg unsafe.Pointer)
 
 func emptyfunc()
+
+// Used by reflectcall and the reflect package.
+//
+// Spills/loads arguments in registers to/from an internal/abi.RegArgs
+// respectively. Does not follow the Go ABI.
+func spillArgs()
+func unspillArgs()
diff --git a/src/runtime/stubs_ppc64.go b/src/runtime/stubs_ppc64.go
new file mode 100644
index 00000000000..f692947109a
--- /dev/null
+++ b/src/runtime/stubs_ppc64.go
@@ -0,0 +1,16 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build linux
+// +build linux
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()
+func reginit()
+
+//go:noescape
+func callCgoSigaction(sig uintptr, new, old *sigactiont) int32
diff --git a/src/runtime/stubs_ppc64x.go b/src/runtime/stubs_ppc64le.go
similarity index 83%
rename from src/runtime/stubs_ppc64x.go
rename to src/runtime/stubs_ppc64le.go
index 0841b413fdb..5b733136e3b 100644
--- a/src/runtime/stubs_ppc64x.go
+++ b/src/runtime/stubs_ppc64le.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ppc64 || ppc64le
-// +build ppc64 ppc64le
-
 package runtime
 
 // Called from assembly only; declared for go vet.
diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index 6b535dfcbfc..d08aa0b3204 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -68,8 +69,15 @@ func CallersFrames(callers []uintptr) *Frames {
 	return f
 }
 
-// Next returns frame information for the next caller.
-// If more is false, there are no more callers (the Frame value is valid).
+// Next returns a Frame representing the next call frame in the slice
+// of PC values. If it has already returned all call frames, Next
+// returns a zero Frame.
+//
+// The more result indicates whether the next call to Next will return
+// a valid Frame. It does not necessarily indicate whether this call
+// returned one.
+//
+// See the Frames example for idiomatic usage.
 func (ci *Frames) Next() (frame Frame, more bool) {
 	for len(ci.frames) < 2 {
 		// Find the next frame.
@@ -323,7 +331,6 @@ const (
 	funcID_gogo
 	funcID_gopanic
 	funcID_handleAsyncEvent
-	funcID_jmpdefer
 	funcID_mcall
 	funcID_morestack
 	funcID_mstart
@@ -561,7 +568,7 @@ const debugPcln = false
 func moduledataverify1(datap *moduledata) {
 	// Check that the pclntab's format is valid.
 	hdr := datap.pcHeader
-	if hdr.magic != 0xfffffffa || hdr.pad1 != 0 || hdr.pad2 != 0 || hdr.minLC != sys.PCQuantum || hdr.ptrSize != sys.PtrSize {
+	if hdr.magic != 0xfffffffa || hdr.pad1 != 0 || hdr.pad2 != 0 || hdr.minLC != sys.PCQuantum || hdr.ptrSize != goarch.PtrSize {
 		print("runtime: function symbol table header:", hex(hdr.magic), hex(hdr.pad1), hex(hdr.pad2), hex(hdr.minLC), hex(hdr.ptrSize))
 		if datap.pluginpath != "" {
 			print(", plugin:", datap.pluginpath)
@@ -779,7 +786,7 @@ type pcvalueCacheEnt struct {
 // For now, align to sys.PtrSize and reduce mod the number of entries.
 // In practice, this appears to be fairly randomly and evenly distributed.
 func pcvalueCacheKey(targetpc uintptr) uintptr {
-	return (targetpc / sys.PtrSize) % uintptr(len(pcvalueCache{}.entries))
+	return (targetpc / goarch.PtrSize) % uintptr(len(pcvalueCache{}.entries))
 }
 
 // Returns the PCData value, and the PC where this value starts.
@@ -948,7 +955,7 @@ func funcline(f funcInfo, targetpc uintptr) (file string, line int32) {
 
 func funcspdelta(f funcInfo, targetpc uintptr, cache *pcvalueCache) int32 {
 	x, _ := pcvalue(f, f.pcsp, targetpc, cache, true)
-	if x&(sys.PtrSize-1) != 0 {
+	if x&(goarch.PtrSize-1) != 0 {
 		print("invalid spdelta ", funcname(f), " ", hex(f.entry), " ", hex(targetpc), " ", hex(f.pcsp), " ", x, "\n")
 	}
 	return x
@@ -1007,13 +1014,13 @@ func funcdata(f funcInfo, i uint8) unsafe.Pointer {
 		return nil
 	}
 	p := add(unsafe.Pointer(&f.nfuncdata), unsafe.Sizeof(f.nfuncdata)+uintptr(f.npcdata)*4)
-	if sys.PtrSize == 8 && uintptr(p)&4 != 0 {
+	if goarch.PtrSize == 8 && uintptr(p)&4 != 0 {
 		if uintptr(unsafe.Pointer(f._func))&4 != 0 {
 			println("runtime: misaligned func", f._func)
 		}
 		p = add(p, 4)
 	}
-	return *(*unsafe.Pointer)(add(p, uintptr(i)*sys.PtrSize))
+	return *(*unsafe.Pointer)(add(p, uintptr(i)*goarch.PtrSize))
 }
 
 // step advances to the next pc, value pair in the encoded table.
diff --git a/src/runtime/sys_aix_ppc64.s b/src/runtime/sys_aix_ppc64.s
index a56d043f425..c171c191c0e 100644
--- a/src/runtime/sys_aix_ppc64.s
+++ b/src/runtime/sys_aix_ppc64.s
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build aix
-// +build ppc64 ppc64le
-
 //
 // System calls and other sys.stuff for ppc64, Aix
 //
diff --git a/src/runtime/sys_darwin_arm64.go b/src/runtime/sys_darwin_arm64.go
index 9c14f33a1ce..e6d4c1be484 100644
--- a/src/runtime/sys_darwin_arm64.go
+++ b/src/runtime/sys_darwin_arm64.go
@@ -5,7 +5,8 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/abi"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -14,14 +15,14 @@ import (
 //go:nosplit
 //go:cgo_unsafe_args
 func g0_pthread_key_create(k *pthreadkey, destructor uintptr) int32 {
-	return asmcgocall(unsafe.Pointer(funcPC(pthread_key_create_trampoline)), unsafe.Pointer(&k))
+	return asmcgocall(unsafe.Pointer(abi.FuncPCABI0(pthread_key_create_trampoline)), unsafe.Pointer(&k))
 }
 func pthread_key_create_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func g0_pthread_setspecific(k pthreadkey, value uintptr) int32 {
-	return asmcgocall(unsafe.Pointer(funcPC(pthread_setspecific_trampoline)), unsafe.Pointer(&k))
+	return asmcgocall(unsafe.Pointer(abi.FuncPCABI0(pthread_setspecific_trampoline)), unsafe.Pointer(&k))
 }
 func pthread_setspecific_trampoline()
 
@@ -53,7 +54,7 @@ func tlsinit(tlsg *uintptr, tlsbase *[_PTHREAD_KEYS_MAX]uintptr) {
 
 	for i, x := range tlsbase {
 		if x == magic {
-			*tlsg = uintptr(i * sys.PtrSize)
+			*tlsg = uintptr(i * goarch.PtrSize)
 			g0_pthread_setspecific(k, 0)
 			return
 		}
diff --git a/src/runtime/sys_libc.go b/src/runtime/sys_libc.go
index 91195eb3c01..b1a9f8b5365 100644
--- a/src/runtime/sys_libc.go
+++ b/src/runtime/sys_libc.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build darwin || (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build darwin openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build darwin || (openbsd && !mips64)
+// +build darwin openbsd,!mips64
 
 package runtime
 
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index 33cc670b641..64ddc2354e6 100644
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -215,13 +215,7 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
 
 	MOVQ	SP, R12	// Save old SP; R12 unchanged by C code.
 
-#ifdef GOEXPERIMENT_regabig
 	MOVQ	g_m(R14), BX // BX unchanged by C code.
-#else
-	get_tls(CX)
-	MOVQ	g(CX), AX
-	MOVQ	g_m(AX), BX // BX unchanged by C code.
-#endif
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
 	// Save the old values on stack and restore them on exit,
@@ -236,11 +230,7 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
 	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	DX, m_vdsoSP(BX)
 
-#ifdef GOEXPERIMENT_regabig
 	CMPQ	R14, m_curg(BX)	// Only switch if on curg.
-#else
-	CMPQ	AX, m_curg(BX)	// Only switch if on curg.
-#endif
 	JNE	noswitch
 
 	MOVQ	m_g0(BX), DX
@@ -328,9 +318,8 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	POPQ	BP
 	RET
 
-// Defined as ABIInternal since it does not use the stack-based Go ABI.
 // Called using C ABI.
-TEXT runtime·sigtramp(SB),NOSPLIT,$0
+TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
@@ -348,8 +337,7 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 
 // Used instead of sigtramp in programs that use cgo.
 // Arguments from kernel are in DI, SI, DX.
-// Defined as ABIInternal since it does not use the stack-based Go ABI.
-TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
+TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
 	// If no traceback function, do usual sigtramp.
 	MOVQ	runtime·cgoTraceback(SB), AX
 	TESTQ	AX, AX
@@ -392,12 +380,12 @@ TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
 	// The first three arguments, and the fifth, are already in registers.
 	// Set the two remaining arguments now.
 	MOVQ	runtime·cgoTraceback(SB), CX
-	MOVQ	$runtime·sigtramp(SB), R9
+	MOVQ	$runtime·sigtramp(SB), R9
 	MOVQ	_cgo_callers(SB), AX
 	JMP	AX
 
 sigtramp:
-	JMP	runtime·sigtramp(SB)
+	JMP	runtime·sigtramp(SB)
 
 sigtrampnog:
 	// Signal arrived on a non-Go thread. If this is SIGPROF, get a
@@ -428,8 +416,7 @@ sigtrampnog:
 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/x86_64/sigaction.c
 // The code that cares about the precise instructions used is:
 // https://gcc.gnu.org/viewcvs/gcc/trunk/libgcc/config/i386/linux-unwind.h?revision=219188&view=markup
-// Defined as ABIInternal since it does not use the stack-based Go ABI.
-TEXT runtime·sigreturn(SB),NOSPLIT,$0
+TEXT runtime·sigreturn(SB),NOSPLIT,$0
 	MOVQ	$SYS_rt_sigreturn, AX
 	SYSCALL
 	INT $3	// not reached
diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index 0206cb88bd4..e18d2914456 100644
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (mips64 || mips64le)
 // +build linux
 // +build mips64 mips64le
 
diff --git a/src/runtime/sys_linux_mipsx.s b/src/runtime/sys_linux_mipsx.s
index d5317d39570..b3970be9cf8 100644
--- a/src/runtime/sys_linux_mipsx.s
+++ b/src/runtime/sys_linux_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (mips || mipsle)
 // +build linux
 // +build mips mipsle
 
diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index 75da130357a..005fa4d2b4d 100644
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (ppc64 || ppc64le)
 // +build linux
 // +build ppc64 ppc64le
 
@@ -215,15 +216,45 @@ TEXT runtime·walltime(SB),NOSPLIT,$16-12
 	MOVD	(g_sched+gobuf_sp)(R7), R1	// Set SP to g0 stack
 
 noswitch:
-	SUB	$16, R1			// Space for results
-	RLDICR	$0, R1, $59, R1		// Align for C code
+	SUB	$16, R1                 // Space for results
+	RLDICR	$0, R1, $59, R1         // Align for C code
 	MOVD	R12, CTR
 	MOVD	R1, R4
-	BL	(CTR)			// Call from VDSO
-	MOVD	$0, R0			// Restore R0
-	MOVD	0(R1), R3		// sec
-	MOVD	8(R1), R5		// nsec
-	MOVD	R15, R1			// Restore SP
+
+	// Store g on gsignal's stack, so if we receive a signal
+	// during VDSO code we can find the g.
+	// If we don't have a signal stack, we won't receive signal,
+	// so don't bother saving g.
+	// When using cgo, we already saved g on TLS, also don't save
+	// g here.
+	// Also don't save g if we are already on the signal stack.
+	// We won't get a nested signal.
+	MOVBZ	runtime·iscgo(SB), R22
+	CMP	R22, $0
+	BNE	nosaveg
+	MOVD	m_gsignal(R21), R22	// g.m.gsignal
+	CMP	R22, $0
+	BEQ	nosaveg
+
+	CMP	g, R22
+	BEQ	nosaveg
+	MOVD	(g_stack+stack_lo)(R22), R22 // g.m.gsignal.stack.lo
+	MOVD	g, (R22)
+
+	BL	(CTR)	// Call from VDSO
+
+	MOVD	$0, (R22)	// clear g slot, R22 is unchanged by C code
+
+	JMP	finish
+
+nosaveg:
+	BL	(CTR)	// Call from VDSO
+
+finish:
+	MOVD	$0, R0		// Restore R0
+	MOVD	0(R1), R3	// sec
+	MOVD	8(R1), R5	// nsec
+	MOVD	R15, R1		// Restore SP
 
 	// Restore vdsoPC, vdsoSP
 	// We don't worry about being signaled between the two stores.
@@ -235,7 +266,7 @@ noswitch:
 	MOVD	32(R1), R6
 	MOVD	R6, m_vdsoPC(R21)
 
-finish:
+return:
 	MOVD	R3, sec+0(FP)
 	MOVW	R5, nsec+8(FP)
 	RET
@@ -246,7 +277,7 @@ fallback:
 	SYSCALL $SYS_clock_gettime
 	MOVD	32(R1), R3
 	MOVD	40(R1), R5
-	JMP	finish
+	JMP	return
 
 TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
 	MOVD	$1, R3		// CLOCK_MONOTONIC
@@ -282,7 +313,37 @@ noswitch:
 	RLDICR	$0, R1, $59, R1		// Align for C code
 	MOVD	R12, CTR
 	MOVD	R1, R4
-	BL	(CTR)			// Call from VDSO
+
+	// Store g on gsignal's stack, so if we receive a signal
+	// during VDSO code we can find the g.
+	// If we don't have a signal stack, we won't receive signal,
+	// so don't bother saving g.
+	// When using cgo, we already saved g on TLS, also don't save
+	// g here.
+	// Also don't save g if we are already on the signal stack.
+	// We won't get a nested signal.
+	MOVBZ	runtime·iscgo(SB), R22
+	CMP	R22, $0
+	BNE	nosaveg
+	MOVD	m_gsignal(R21), R22	// g.m.gsignal
+	CMP	R22, $0
+	BEQ	nosaveg
+
+	CMP	g, R22
+	BEQ	nosaveg
+	MOVD	(g_stack+stack_lo)(R22), R22 // g.m.gsignal.stack.lo
+	MOVD	g, (R22)
+
+	BL	(CTR)	// Call from VDSO
+
+	MOVD	$0, (R22)	// clear g slot, R22 is unchanged by C code
+
+	JMP	finish
+
+nosaveg:
+	BL	(CTR)	// Call from VDSO
+
+finish:
 	MOVD	$0, R0			// Restore R0
 	MOVD	0(R1), R3		// sec
 	MOVD	8(R1), R5		// nsec
@@ -298,7 +359,7 @@ noswitch:
 	MOVD	32(R1), R6
 	MOVD	R6, m_vdsoPC(R21)
 
-finish:
+return:
 	// sec is in R3, nsec in R5
 	// return nsec in R3
 	MOVD	$1000000000, R4
@@ -313,7 +374,7 @@ fallback:
 	SYSCALL $SYS_clock_gettime
 	MOVD	32(R1), R3
 	MOVD	40(R1), R5
-	JMP	finish
+	JMP	return
 
 TEXT runtime·rtsigprocmask(SB),NOSPLIT|NOFRAME,$0-28
 	MOVW	how+0(FP), R3
@@ -336,6 +397,26 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT|NOFRAME,$0-36
 	MOVW	R3, ret+32(FP)
 	RET
 
+#ifdef GOARCH_ppc64le
+// Call the function stored in _cgo_sigaction using the GCC calling convention.
+TEXT runtime·callCgoSigaction(SB),NOSPLIT,$0
+	MOVD    sig+0(FP), R3
+	MOVD    new+8(FP), R4
+	MOVD    old+16(FP), R5
+	MOVD     _cgo_sigaction(SB), R12
+	MOVD    R12, CTR                // R12 should contain the function address
+	MOVD    R1, R15                 // Save R1
+	MOVD    R2, 24(R1)              // Save R2
+	SUB     $48, R1                 // reserve 32 (frame) + 16 bytes for sp-8 where fp may be saved.
+	RLDICR  $0, R1, $59, R1         // Align to 16 bytes for C code
+	BL      (CTR)
+	XOR     R0, R0, R0              // Clear R0 as Go expects
+	MOVD    R15, R1                 // Restore R1
+	MOVD    24(R1), R2              // Restore R2
+	MOVW    R3, ret+24(FP)          // Return result
+	RET
+#endif
+
 TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	MOVW	sig+8(FP), R3
 	MOVD	info+16(FP), R4
@@ -351,22 +432,104 @@ TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
 
 #ifdef GOARCH_ppc64le
 // ppc64le doesn't need function descriptors
-TEXT runtime·sigtramp(SB),NOSPLIT,$64
+// Save callee-save registers in the case of signal forwarding.
+// Same as on ARM64 https://golang.org/issue/31827 .
+TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
 #else
 // function descriptor for the real sigtramp
 TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
 	DWORD	$sigtramp<>(SB)
 	DWORD	$0
 	DWORD	$0
-TEXT sigtramp<>(SB),NOSPLIT,$64
+TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0
 #endif
+	// Start with standard C stack frame layout and linkage.
+	MOVD    LR, R0
+	MOVD    R0, 16(R1) // Save LR in caller's frame.
+	MOVW    CR, R0     // Save CR in caller's frame
+	MOVD    R0, 8(R1)
+	// The stack must be acquired here and not
+	// in the automatic way based on stack size
+	// since that sequence clobbers R31 before it
+	// gets saved.
+	// We are being ultra safe here in saving the
+	// Vregs. The case where they might need to
+	// be saved is very unlikely.
+	MOVDU   R1, -544(R1)
+	MOVD    R14, 64(R1)
+	MOVD    R15, 72(R1)
+	MOVD    R16, 80(R1)
+	MOVD    R17, 88(R1)
+	MOVD    R18, 96(R1)
+	MOVD    R19, 104(R1)
+	MOVD    R20, 112(R1)
+	MOVD    R21, 120(R1)
+	MOVD    R22, 128(R1)
+	MOVD    R23, 136(R1)
+	MOVD    R24, 144(R1)
+	MOVD    R25, 152(R1)
+	MOVD    R26, 160(R1)
+	MOVD    R27, 168(R1)
+	MOVD    R28, 176(R1)
+	MOVD    R29, 184(R1)
+	MOVD    g, 192(R1) // R30
+	MOVD    R31, 200(R1)
+	FMOVD   F14, 208(R1)
+	FMOVD   F15, 216(R1)
+	FMOVD   F16, 224(R1)
+	FMOVD   F17, 232(R1)
+	FMOVD   F18, 240(R1)
+	FMOVD   F19, 248(R1)
+	FMOVD   F20, 256(R1)
+	FMOVD   F21, 264(R1)
+	FMOVD   F22, 272(R1)
+	FMOVD   F23, 280(R1)
+	FMOVD   F24, 288(R1)
+	FMOVD   F25, 296(R1)
+	FMOVD   F26, 304(R1)
+	FMOVD   F27, 312(R1)
+	FMOVD   F28, 320(R1)
+	FMOVD   F29, 328(R1)
+	FMOVD   F30, 336(R1)
+	FMOVD   F31, 344(R1)
+	// Save V regs
+	// STXVD2X and LXVD2X used since
+	// we aren't sure of alignment.
+	// Endianness doesn't matter
+	// if we are just loading and
+	// storing values.
+	MOVD	$352, R7 // V20
+	STXVD2X VS52, (R7)(R1)
+	ADD	$16, R7 // V21 368
+	STXVD2X VS53, (R7)(R1)
+	ADD	$16, R7 // V22 384
+	STXVD2X VS54, (R7)(R1)
+	ADD	$16, R7 // V23 400
+	STXVD2X VS55, (R7)(R1)
+	ADD	$16, R7 // V24 416
+	STXVD2X	VS56, (R7)(R1)
+	ADD	$16, R7 // V25 432
+	STXVD2X	VS57, (R7)(R1)
+	ADD	$16, R7 // V26 448
+	STXVD2X VS58, (R7)(R1)
+	ADD	$16, R7 // V27 464
+	STXVD2X VS59, (R7)(R1)
+	ADD	$16, R7 // V28 480
+	STXVD2X VS60, (R7)(R1)
+	ADD	$16, R7 // V29 496
+	STXVD2X VS61, (R7)(R1)
+	ADD	$16, R7 // V30 512
+	STXVD2X VS62, (R7)(R1)
+	ADD	$16, R7 // V31 528
+	STXVD2X VS63, (R7)(R1)
+
 	// initialize essential registers (just in case)
 	BL	runtime·reginit(SB)
 
 	// this might be called in external code context,
 	// where g is not set.
 	MOVBZ	runtime·iscgo(SB), R6
-	CMP 	R6, $0
+	CMP	R6, $0
 	BEQ	2(PC)
 	BL	runtime·load_g(SB)
 
@@ -376,7 +539,74 @@ TEXT sigtramp<>(SB),NOSPLIT,$64
 	MOVD	$runtime·sigtrampgo(SB), R12
 	MOVD	R12, CTR
 	BL	(CTR)
-	MOVD	24(R1), R2
+	MOVD	24(R1), R2 // Should this be here? Where is it saved?
+	// Starts at 64; FIXED_FRAME is 32
+	MOVD    64(R1), R14
+	MOVD    72(R1), R15
+	MOVD    80(R1), R16
+	MOVD    88(R1), R17
+	MOVD    96(R1), R18
+	MOVD    104(R1), R19
+	MOVD    112(R1), R20
+	MOVD    120(R1), R21
+	MOVD    128(R1), R22
+	MOVD    136(R1), R23
+	MOVD    144(R1), R24
+	MOVD    152(R1), R25
+	MOVD    160(R1), R26
+	MOVD    168(R1), R27
+	MOVD    176(R1), R28
+	MOVD    184(R1), R29
+	MOVD    192(R1), g // R30
+	MOVD    200(R1), R31
+	FMOVD   208(R1), F14
+	FMOVD   216(R1), F15
+	FMOVD   224(R1), F16
+	FMOVD   232(R1), F17
+	FMOVD   240(R1), F18
+	FMOVD   248(R1), F19
+	FMOVD   256(R1), F20
+	FMOVD   264(R1), F21
+	FMOVD   272(R1), F22
+	FMOVD   280(R1), F23
+	FMOVD   288(R1), F24
+	FMOVD   292(R1), F25
+	FMOVD   300(R1), F26
+	FMOVD   308(R1), F27
+	FMOVD   316(R1), F28
+	FMOVD   328(R1), F29
+	FMOVD   336(R1), F30
+	FMOVD   344(R1), F31
+	MOVD	$352, R7
+	LXVD2X	(R7)(R1), VS52
+	ADD	$16, R7 // 368 V21
+	LXVD2X	(R7)(R1), VS53
+	ADD	$16, R7 // 384 V22
+	LXVD2X	(R7)(R1), VS54
+	ADD	$16, R7 // 400 V23
+	LXVD2X	(R7)(R1), VS55
+	ADD	$16, R7 // 416 V24
+	LXVD2X	(R7)(R1), VS56
+	ADD	$16, R7 // 432 V25
+	LXVD2X	(R7)(R1), VS57
+	ADD	$16, R7 // 448 V26
+	LXVD2X	(R7)(R1), VS58
+	ADD	$16, R8 // 464 V27
+	LXVD2X	(R7)(R1), VS59
+	ADD	$16, R7 // 480 V28
+	LXVD2X	(R7)(R1), VS60
+	ADD	$16, R7 // 496 V29
+	LXVD2X	(R7)(R1), VS61
+	ADD	$16, R7 // 512 V30
+	LXVD2X	(R7)(R1), VS62
+	ADD	$16, R7 // 528 V31
+	LXVD2X	(R7)(R1), VS63
+	ADD	$544, R1
+	MOVD	8(R1), R0
+	MOVFL	R0, $0xff
+	MOVD	16(R1), R0
+	MOVD	R0, LR
+
 	RET
 
 #ifdef GOARCH_ppc64le
@@ -406,6 +636,7 @@ TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
 
 	// Figure out if we are currently in a cgo call.
 	// If not, just do usual sigtramp.
+	// compared to ARM64 and others.
 	CMP	$0, g
 	BEQ	sigtrampnog // g == nil
 	MOVD	g_m(g), R6
diff --git a/src/runtime/sys_openbsd.go b/src/runtime/sys_openbsd.go
index f6146c2e1d1..15888619b17 100644
--- a/src/runtime/sys_openbsd.go
+++ b/src/runtime/sys_openbsd.go
@@ -2,12 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 // The *_trampoline functions convert from the Go calling convention to the C calling convention
 // and then call the underlying libc function. These are defined in sys_openbsd_$ARCH.s.
@@ -15,35 +18,35 @@ import "unsafe"
 //go:nosplit
 //go:cgo_unsafe_args
 func pthread_attr_init(attr *pthreadattr) int32 {
-	return libcCall(unsafe.Pointer(funcPC(pthread_attr_init_trampoline)), unsafe.Pointer(&attr))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(pthread_attr_init_trampoline)), unsafe.Pointer(&attr))
 }
 func pthread_attr_init_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func pthread_attr_destroy(attr *pthreadattr) int32 {
-	return libcCall(unsafe.Pointer(funcPC(pthread_attr_destroy_trampoline)), unsafe.Pointer(&attr))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(pthread_attr_destroy_trampoline)), unsafe.Pointer(&attr))
 }
 func pthread_attr_destroy_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func pthread_attr_getstacksize(attr *pthreadattr, size *uintptr) int32 {
-	return libcCall(unsafe.Pointer(funcPC(pthread_attr_getstacksize_trampoline)), unsafe.Pointer(&attr))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(pthread_attr_getstacksize_trampoline)), unsafe.Pointer(&attr))
 }
 func pthread_attr_getstacksize_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func pthread_attr_setdetachstate(attr *pthreadattr, state int) int32 {
-	return libcCall(unsafe.Pointer(funcPC(pthread_attr_setdetachstate_trampoline)), unsafe.Pointer(&attr))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(pthread_attr_setdetachstate_trampoline)), unsafe.Pointer(&attr))
 }
 func pthread_attr_setdetachstate_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func pthread_create(attr *pthreadattr, start uintptr, arg unsafe.Pointer) int32 {
-	return libcCall(unsafe.Pointer(funcPC(pthread_create_trampoline)), unsafe.Pointer(&attr))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(pthread_create_trampoline)), unsafe.Pointer(&attr))
 }
 func pthread_create_trampoline()
 
diff --git a/src/runtime/sys_openbsd1.go b/src/runtime/sys_openbsd1.go
index b007b6d3f59..b4e9f54538e 100644
--- a/src/runtime/sys_openbsd1.go
+++ b/src/runtime/sys_openbsd1.go
@@ -2,35 +2,39 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 //go:nosplit
 //go:cgo_unsafe_args
 func thrsleep(ident uintptr, clock_id int32, tsp *timespec, lock uintptr, abort *uint32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(thrsleep_trampoline)), unsafe.Pointer(&ident))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(thrsleep_trampoline)), unsafe.Pointer(&ident))
 }
 func thrsleep_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func thrwakeup(ident uintptr, n int32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(thrwakeup_trampoline)), unsafe.Pointer(&ident))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(thrwakeup_trampoline)), unsafe.Pointer(&ident))
 }
 func thrwakeup_trampoline()
 
+//go:nosplit
 func osyield() {
-	libcCall(unsafe.Pointer(funcPC(sched_yield_trampoline)), unsafe.Pointer(nil))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(sched_yield_trampoline)), unsafe.Pointer(nil))
 }
 func sched_yield_trampoline()
 
 //go:nosplit
 func osyield_no_g() {
-	asmcgocall_no_g(unsafe.Pointer(funcPC(sched_yield_trampoline)), unsafe.Pointer(nil))
+	asmcgocall_no_g(unsafe.Pointer(abi.FuncPCABI0(sched_yield_trampoline)), unsafe.Pointer(nil))
 }
 
 //go:cgo_import_dynamic libc_thrsleep __thrsleep "libc.so"
diff --git a/src/runtime/sys_openbsd2.go b/src/runtime/sys_openbsd2.go
index 91ed04fb486..190ee4716a6 100644
--- a/src/runtime/sys_openbsd2.go
+++ b/src/runtime/sys_openbsd2.go
@@ -2,26 +2,29 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 // This is exported via linkname to assembly in runtime/cgo.
 //go:linkname exit
 //go:nosplit
 //go:cgo_unsafe_args
 func exit(code int32) {
-	libcCall(unsafe.Pointer(funcPC(exit_trampoline)), unsafe.Pointer(&code))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(exit_trampoline)), unsafe.Pointer(&code))
 }
 func exit_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func getthrid() (tid int32) {
-	libcCall(unsafe.Pointer(funcPC(getthrid_trampoline)), unsafe.Pointer(&tid))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(getthrid_trampoline)), unsafe.Pointer(&tid))
 	return
 }
 func getthrid_trampoline()
@@ -29,14 +32,14 @@ func getthrid_trampoline()
 //go:nosplit
 //go:cgo_unsafe_args
 func raiseproc(sig uint32) {
-	libcCall(unsafe.Pointer(funcPC(raiseproc_trampoline)), unsafe.Pointer(&sig))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(raiseproc_trampoline)), unsafe.Pointer(&sig))
 }
 func raiseproc_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func thrkill(tid int32, sig int) {
-	libcCall(unsafe.Pointer(funcPC(thrkill_trampoline)), unsafe.Pointer(&tid))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(thrkill_trampoline)), unsafe.Pointer(&tid))
 }
 func thrkill_trampoline()
 
@@ -53,7 +56,7 @@ func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (un
 		ret1            unsafe.Pointer
 		ret2            int
 	}{addr, n, prot, flags, fd, off, nil, 0}
-	libcCall(unsafe.Pointer(funcPC(mmap_trampoline)), unsafe.Pointer(&args))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(mmap_trampoline)), unsafe.Pointer(&args))
 	return args.ret1, args.ret2
 }
 func mmap_trampoline()
@@ -61,42 +64,42 @@ func mmap_trampoline()
 //go:nosplit
 //go:cgo_unsafe_args
 func munmap(addr unsafe.Pointer, n uintptr) {
-	libcCall(unsafe.Pointer(funcPC(munmap_trampoline)), unsafe.Pointer(&addr))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(munmap_trampoline)), unsafe.Pointer(&addr))
 }
 func munmap_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func madvise(addr unsafe.Pointer, n uintptr, flags int32) {
-	libcCall(unsafe.Pointer(funcPC(madvise_trampoline)), unsafe.Pointer(&addr))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(madvise_trampoline)), unsafe.Pointer(&addr))
 }
 func madvise_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func open(name *byte, mode, perm int32) (ret int32) {
-	return libcCall(unsafe.Pointer(funcPC(open_trampoline)), unsafe.Pointer(&name))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(open_trampoline)), unsafe.Pointer(&name))
 }
 func open_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func closefd(fd int32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(close_trampoline)), unsafe.Pointer(&fd))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(close_trampoline)), unsafe.Pointer(&fd))
 }
 func close_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func read(fd int32, p unsafe.Pointer, n int32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(read_trampoline)), unsafe.Pointer(&fd))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(read_trampoline)), unsafe.Pointer(&fd))
 }
 func read_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(write_trampoline)), unsafe.Pointer(&fd))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(write_trampoline)), unsafe.Pointer(&fd))
 }
 func write_trampoline()
 
@@ -110,7 +113,7 @@ func pipe2(flags int32) (r, w int32, errno int32) {
 		p     unsafe.Pointer
 		flags int32
 	}{noescape(unsafe.Pointer(&p)), flags}
-	errno = libcCall(unsafe.Pointer(funcPC(pipe2_trampoline)), unsafe.Pointer(&args))
+	errno = libcCall(unsafe.Pointer(abi.FuncPCABI0(pipe2_trampoline)), unsafe.Pointer(&args))
 	return p[0], p[1], errno
 }
 func pipe2_trampoline()
@@ -118,34 +121,34 @@ func pipe2_trampoline()
 //go:nosplit
 //go:cgo_unsafe_args
 func setitimer(mode int32, new, old *itimerval) {
-	libcCall(unsafe.Pointer(funcPC(setitimer_trampoline)), unsafe.Pointer(&mode))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(setitimer_trampoline)), unsafe.Pointer(&mode))
 }
 func setitimer_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func usleep(usec uint32) {
-	libcCall(unsafe.Pointer(funcPC(usleep_trampoline)), unsafe.Pointer(&usec))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(usleep_trampoline)), unsafe.Pointer(&usec))
 }
 func usleep_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func usleep_no_g(usec uint32) {
-	asmcgocall_no_g(unsafe.Pointer(funcPC(usleep_trampoline)), unsafe.Pointer(&usec))
+	asmcgocall_no_g(unsafe.Pointer(abi.FuncPCABI0(usleep_trampoline)), unsafe.Pointer(&usec))
 }
 
 //go:nosplit
 //go:cgo_unsafe_args
 func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32 {
-	return libcCall(unsafe.Pointer(funcPC(sysctl_trampoline)), unsafe.Pointer(&mib))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(sysctl_trampoline)), unsafe.Pointer(&mib))
 }
 func sysctl_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func fcntl(fd, cmd, arg int32) int32 {
-	return libcCall(unsafe.Pointer(funcPC(fcntl_trampoline)), unsafe.Pointer(&fd))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(fcntl_trampoline)), unsafe.Pointer(&fd))
 }
 func fcntl_trampoline()
 
@@ -156,7 +159,7 @@ func nanotime1() int64 {
 		clock_id int32
 		tp       unsafe.Pointer
 	}{_CLOCK_MONOTONIC, unsafe.Pointer(&ts)}
-	libcCall(unsafe.Pointer(funcPC(clock_gettime_trampoline)), unsafe.Pointer(&args))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(clock_gettime_trampoline)), unsafe.Pointer(&args))
 	return ts.tv_sec*1e9 + int64(ts.tv_nsec)
 }
 func clock_gettime_trampoline()
@@ -168,42 +171,42 @@ func walltime() (int64, int32) {
 		clock_id int32
 		tp       unsafe.Pointer
 	}{_CLOCK_REALTIME, unsafe.Pointer(&ts)}
-	libcCall(unsafe.Pointer(funcPC(clock_gettime_trampoline)), unsafe.Pointer(&args))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(clock_gettime_trampoline)), unsafe.Pointer(&args))
 	return ts.tv_sec, int32(ts.tv_nsec)
 }
 
 //go:nosplit
 //go:cgo_unsafe_args
 func kqueue() int32 {
-	return libcCall(unsafe.Pointer(funcPC(kqueue_trampoline)), nil)
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(kqueue_trampoline)), nil)
 }
 func kqueue_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32 {
-	return libcCall(unsafe.Pointer(funcPC(kevent_trampoline)), unsafe.Pointer(&kq))
+	return libcCall(unsafe.Pointer(abi.FuncPCABI0(kevent_trampoline)), unsafe.Pointer(&kq))
 }
 func kevent_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func sigaction(sig uint32, new *sigactiont, old *sigactiont) {
-	libcCall(unsafe.Pointer(funcPC(sigaction_trampoline)), unsafe.Pointer(&sig))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(sigaction_trampoline)), unsafe.Pointer(&sig))
 }
 func sigaction_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func sigprocmask(how uint32, new *sigset, old *sigset) {
-	libcCall(unsafe.Pointer(funcPC(sigprocmask_trampoline)), unsafe.Pointer(&how))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(sigprocmask_trampoline)), unsafe.Pointer(&how))
 }
 func sigprocmask_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
 func sigaltstack(new *stackt, old *stackt) {
-	libcCall(unsafe.Pointer(funcPC(sigaltstack_trampoline)), unsafe.Pointer(&new))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(sigaltstack_trampoline)), unsafe.Pointer(&new))
 }
 func sigaltstack_trampoline()
 
diff --git a/src/runtime/sys_openbsd3.go b/src/runtime/sys_openbsd3.go
index 8fdee05733c..a917ebde610 100644
--- a/src/runtime/sys_openbsd3.go
+++ b/src/runtime/sys_openbsd3.go
@@ -2,12 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 // The X versions of syscall expect the libc call to return a 64-bit result.
 // Otherwise (the non-X version) expects a 32-bit result.
@@ -20,7 +23,7 @@ import "unsafe"
 //go:cgo_unsafe_args
 func syscall_syscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscall)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -31,7 +34,7 @@ func syscall()
 //go:cgo_unsafe_args
 func syscall_syscallX(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscallX)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscallX)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -42,7 +45,7 @@ func syscallX()
 //go:cgo_unsafe_args
 func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscall6)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall6)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -53,7 +56,7 @@ func syscall6()
 //go:cgo_unsafe_args
 func syscall_syscall6X(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscall6X)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall6X)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -64,7 +67,7 @@ func syscall6X()
 //go:cgo_unsafe_args
 func syscall_syscall10(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscall10)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall10)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -75,7 +78,7 @@ func syscall10()
 //go:cgo_unsafe_args
 func syscall_syscall10X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10 uintptr) (r1, r2, err uintptr) {
 	entersyscall()
-	libcCall(unsafe.Pointer(funcPC(syscall10X)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall10X)), unsafe.Pointer(&fn))
 	exitsyscall()
 	return
 }
@@ -85,7 +88,7 @@ func syscall10X()
 //go:nosplit
 //go:cgo_unsafe_args
 func syscall_rawSyscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
-	libcCall(unsafe.Pointer(funcPC(syscall)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall)), unsafe.Pointer(&fn))
 	return
 }
 
@@ -93,7 +96,7 @@ func syscall_rawSyscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 //go:nosplit
 //go:cgo_unsafe_args
 func syscall_rawSyscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
-	libcCall(unsafe.Pointer(funcPC(syscall6)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall6)), unsafe.Pointer(&fn))
 	return
 }
 
@@ -101,7 +104,7 @@ func syscall_rawSyscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintpt
 //go:nosplit
 //go:cgo_unsafe_args
 func syscall_rawSyscall6X(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
-	libcCall(unsafe.Pointer(funcPC(syscall6X)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall6X)), unsafe.Pointer(&fn))
 	return
 }
 
@@ -109,6 +112,6 @@ func syscall_rawSyscall6X(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintp
 //go:nosplit
 //go:cgo_unsafe_args
 func syscall_rawSyscall10X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10 uintptr) (r1, r2, err uintptr) {
-	libcCall(unsafe.Pointer(funcPC(syscall10X)), unsafe.Pointer(&fn))
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall10X)), unsafe.Pointer(&fn))
 	return
 }
diff --git a/src/runtime/sys_openbsd_amd64.s b/src/runtime/sys_openbsd_amd64.s
index 522e98cf4f5..fc89ee6cbbd 100644
--- a/src/runtime/sys_openbsd_amd64.s
+++ b/src/runtime/sys_openbsd_amd64.s
@@ -58,7 +58,7 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	RET
 
 // Called using C ABI.
-TEXT runtime·sigtramp(SB),NOSPLIT,$0
+TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// Transition from C ABI to Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
diff --git a/src/runtime/sys_openbsd_arm.s b/src/runtime/sys_openbsd_arm.s
index 45d69a312a8..143fcf05184 100644
--- a/src/runtime/sys_openbsd_arm.s
+++ b/src/runtime/sys_openbsd_arm.s
@@ -10,7 +10,7 @@
 #include "go_tls.h"
 #include "textflag.h"
 
-#define CLOCK_REALTIME	$0
+#define	CLOCK_REALTIME	$0
 #define	CLOCK_MONOTONIC	$3
 
 // With OpenBSD 6.7 onwards, an armv7 syscall returns two instructions
@@ -25,238 +25,40 @@
 	NOOP;		\
 	NOOP
 
-// Exit the entire program (like C exit)
-TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0
-	MOVW	code+0(FP), R0	// arg 1 - status
-	MOVW	$1, R12			// sys_exit
-	INVOKE_SYSCALL
-	MOVW.CS	$0, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	RET
+// mstart_stub is the first function executed on a new thread started by pthread_create.
+// It just does some low-level setup and then calls mstart.
+// Note: called with the C calling convention.
+TEXT runtime·mstart_stub(SB),NOSPLIT,$0
+	// R0 points to the m.
+	// We are already on m's g0 stack.
 
-// func exitThread(wait *uint32)
-TEXT runtime·exitThread(SB),NOSPLIT,$0-4
-	MOVW	wait+0(FP), R0		// arg 1 - notdead
-	MOVW	$302, R12		// sys___threxit
-	INVOKE_SYSCALL
-	MOVW.CS	$1, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	JMP	0(PC)
+	// Save callee-save registers.
+	MOVM.DB.W [R4-R11], (R13)
 
-TEXT runtime·open(SB),NOSPLIT|NOFRAME,$0
-	MOVW	name+0(FP), R0		// arg 1 - path
-	MOVW	mode+4(FP), R1		// arg 2 - mode
-	MOVW	perm+8(FP), R2		// arg 3 - perm
-	MOVW	$5, R12			// sys_open
-	INVOKE_SYSCALL
-	MOVW.CS	$-1, R0
-	MOVW	R0, ret+12(FP)
-	RET
+	MOVW	m_g0(R0), g
+	BL	runtime·save_g(SB)
 
-TEXT runtime·closefd(SB),NOSPLIT|NOFRAME,$0
-	MOVW	fd+0(FP), R0		// arg 1 - fd
-	MOVW	$6, R12			// sys_close
-	INVOKE_SYSCALL
-	MOVW.CS	$-1, R0
-	MOVW	R0, ret+4(FP)
-	RET
+	BL	runtime·mstart(SB)
 
-TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
-	MOVW	fd+0(FP), R0		// arg 1 - fd
-	MOVW	p+4(FP), R1		// arg 2 - buf
-	MOVW	n+8(FP), R2		// arg 3 - nbyte
-	MOVW	$3, R12			// sys_read
-	INVOKE_SYSCALL
-	RSB.CS	$0, R0		// caller expects negative errno
-	MOVW	R0, ret+12(FP)
-	RET
+	// Restore callee-save registers.
+	MOVM.IA.W (R13), [R4-R11]
 
-// func pipe() (r, w int32, errno int32)
-TEXT runtime·pipe(SB),NOSPLIT,$0-12
-	MOVW	$r+0(FP), R0
-	MOVW	$263, R12
-	INVOKE_SYSCALL
-	MOVW	R0, errno+8(FP)
-	RET
-
-// func pipe2(flags int32) (r, w int32, errno int32)
-TEXT runtime·pipe2(SB),NOSPLIT,$0-16
-	MOVW	$r+4(FP), R0
-	MOVW	flags+0(FP), R1
-	MOVW	$101, R12
-	INVOKE_SYSCALL
-	MOVW	R0, errno+12(FP)
-	RET
-
-TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
-	MOVW	fd+0(FP), R0		// arg 1 - fd
-	MOVW	p+4(FP), R1		// arg 2 - buf
-	MOVW	n+8(FP), R2		// arg 3 - nbyte
-	MOVW	$4, R12			// sys_write
-	INVOKE_SYSCALL
-	RSB.CS	$0, R0		// caller expects negative errno
-	MOVW	R0, ret+12(FP)
-	RET
-
-TEXT runtime·usleep(SB),NOSPLIT,$16
-	MOVW	usec+0(FP), R0
-	CALL	runtime·usplitR0(SB)
-	MOVW	R0, 4(R13)		// tv_sec - l32
+	// Go is all done with this OS thread.
+	// Tell pthread everything is ok (we never join with this thread, so
+	// the value here doesn't really matter).
 	MOVW	$0, R0
-	MOVW	R0, 8(R13)		// tv_sec - h32
-	MOVW	$1000, R2
-	MUL	R1, R2
-	MOVW	R2, 12(R13)		// tv_nsec
-
-	MOVW	$4(R13), R0		// arg 1 - rqtp
-	MOVW	$0, R1			// arg 2 - rmtp
-	MOVW	$91, R12		// sys_nanosleep
-	INVOKE_SYSCALL
-	RET
-
-TEXT runtime·getthrid(SB),NOSPLIT,$0-4
-	MOVW	$299, R12		// sys_getthrid
-	INVOKE_SYSCALL
-	MOVW	R0, ret+0(FP)
-	RET
-
-TEXT runtime·thrkill(SB),NOSPLIT,$0-8
-	MOVW	tid+0(FP), R0		// arg 1 - tid
-	MOVW	sig+4(FP), R1		// arg 2 - signum
-	MOVW	$0, R2			// arg 3 - tcb
-	MOVW	$119, R12		// sys_thrkill
-	INVOKE_SYSCALL
-	RET
-
-TEXT runtime·raiseproc(SB),NOSPLIT,$12
-	MOVW	$20, R12		// sys_getpid
-	INVOKE_SYSCALL
-					// arg 1 - pid, already in R0
-	MOVW	sig+0(FP), R1		// arg 2 - signum
-	MOVW	$122, R12		// sys_kill
-	INVOKE_SYSCALL
-	RET
-
-TEXT runtime·mmap(SB),NOSPLIT,$16
-	MOVW	addr+0(FP), R0		// arg 1 - addr
-	MOVW	n+4(FP), R1		// arg 2 - len
-	MOVW	prot+8(FP), R2		// arg 3 - prot
-	MOVW	flags+12(FP), R3	// arg 4 - flags
-	MOVW	fd+16(FP), R4		// arg 5 - fd (on stack)
-	MOVW	R4, 4(R13)
-	MOVW	$0, R5			// arg 6 - pad (on stack)
-	MOVW	R5, 8(R13)
-	MOVW	off+20(FP), R6		// arg 7 - offset (on stack)
-	MOVW	R6, 12(R13)		// lower 32 bits (from Go runtime)
-	MOVW	$0, R7
-	MOVW	R7, 16(R13)		// high 32 bits
-	ADD	$4, R13
-	MOVW	$197, R12		// sys_mmap
-	INVOKE_SYSCALL
-	SUB	$4, R13
-	MOVW	$0, R1
-	MOVW.CS	R0, R1			// if error, move to R1
-	MOVW.CS $0, R0
-	MOVW	R0, p+24(FP)
-	MOVW	R1, err+28(FP)
-	RET
-
-TEXT runtime·munmap(SB),NOSPLIT,$0
-	MOVW	addr+0(FP), R0		// arg 1 - addr
-	MOVW	n+4(FP), R1		// arg 2 - len
-	MOVW	$73, R12		// sys_munmap
-	INVOKE_SYSCALL
-	MOVW.CS	$0, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	RET
-
-TEXT runtime·madvise(SB),NOSPLIT,$0
-	MOVW	addr+0(FP), R0		// arg 1 - addr
-	MOVW	n+4(FP), R1		// arg 2 - len
-	MOVW	flags+8(FP), R2		// arg 2 - flags
-	MOVW	$75, R12		// sys_madvise
-	INVOKE_SYSCALL
-	MOVW.CS	$-1, R0
-	MOVW	R0, ret+12(FP)
-	RET
-
-TEXT runtime·setitimer(SB),NOSPLIT,$0
-	MOVW	mode+0(FP), R0		// arg 1 - mode
-	MOVW	new+4(FP), R1		// arg 2 - new value
-	MOVW	old+8(FP), R2		// arg 3 - old value
-	MOVW	$69, R12		// sys_setitimer
-	INVOKE_SYSCALL
-	RET
-
-// func walltime() (sec int64, nsec int32)
-TEXT runtime·walltime(SB), NOSPLIT, $32
-	MOVW	CLOCK_REALTIME, R0	// arg 1 - clock_id
-	MOVW	$8(R13), R1		// arg 2 - tp
-	MOVW	$87, R12		// sys_clock_gettime
-	INVOKE_SYSCALL
-
-	MOVW	8(R13), R0		// sec - l32
-	MOVW	12(R13), R1		// sec - h32
-	MOVW	16(R13), R2		// nsec
-
-	MOVW	R0, sec_lo+0(FP)
-	MOVW	R1, sec_hi+4(FP)
-	MOVW	R2, nsec+8(FP)
-
-	RET
-
-// int64 nanotime1(void) so really
-// void nanotime1(int64 *nsec)
-TEXT runtime·nanotime1(SB),NOSPLIT,$32
-	MOVW	CLOCK_MONOTONIC, R0	// arg 1 - clock_id
-	MOVW	$8(R13), R1		// arg 2 - tp
-	MOVW	$87, R12		// sys_clock_gettime
-	INVOKE_SYSCALL
-
-	MOVW	8(R13), R0		// sec - l32
-	MOVW	12(R13), R4		// sec - h32
-	MOVW	16(R13), R2		// nsec
-
-	MOVW	$1000000000, R3
-	MULLU	R0, R3, (R1, R0)
-	MUL	R3, R4
-	ADD.S	R2, R0
-	ADC	R4, R1
-
-	MOVW	R0, ret_lo+0(FP)
-	MOVW	R1, ret_hi+4(FP)
-	RET
-
-TEXT runtime·sigaction(SB),NOSPLIT,$0
-	MOVW	sig+0(FP), R0		// arg 1 - signum
-	MOVW	new+4(FP), R1		// arg 2 - new sigaction
-	MOVW	old+8(FP), R2		// arg 3 - old sigaction
-	MOVW	$46, R12		// sys_sigaction
-	INVOKE_SYSCALL
-	MOVW.CS	$3, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	RET
-
-TEXT runtime·obsdsigprocmask(SB),NOSPLIT,$0
-	MOVW	how+0(FP), R0		// arg 1 - mode
-	MOVW	new+4(FP), R1		// arg 2 - new
-	MOVW	$48, R12		// sys_sigprocmask
-	INVOKE_SYSCALL
-	MOVW.CS	$3, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	MOVW	R0, ret+8(FP)
 	RET
 
 TEXT runtime·sigfwd(SB),NOSPLIT,$0-16
 	MOVW	sig+4(FP), R0
 	MOVW	info+8(FP), R1
 	MOVW	ctx+12(FP), R2
-	MOVW	fn+0(FP), R11
-	MOVW	R13, R4
+	MOVW	fn+0(FP), R3
+	MOVW	R13, R9
 	SUB	$24, R13
 	BIC	$0x7, R13 // alignment for ELF ABI
-	BL	(R11)
-	MOVW	R4, R13
+	BL	(R3)
+	MOVW	R9, R13
 	RET
 
 TEXT runtime·sigtramp(SB),NOSPLIT,$0
@@ -267,9 +69,7 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 	// If called from an external code context, g will not be set.
 	// Save R0, since runtime·load_g will clobber it.
 	MOVW	R0, 4(R13)		// signum
-	MOVB	runtime·iscgo(SB), R0
-	CMP	$0, R0
-	BL.NE	runtime·load_g(SB)
+	BL	runtime·load_g(SB)
 
 	MOVW	R1, 8(R13)
 	MOVW	R2, 12(R13)
@@ -281,155 +81,726 @@ TEXT runtime·sigtramp(SB),NOSPLIT,$0
 
 	RET
 
-// int32 tfork(void *param, uintptr psize, M *mp, G *gp, void (*fn)(void));
-TEXT runtime·tfork(SB),NOSPLIT,$0
-
-	// Copy mp, gp and fn off parent stack for use by child.
-	MOVW	mm+8(FP), R4
-	MOVW	gg+12(FP), R5
-	MOVW	fn+16(FP), R6
-
-	MOVW	param+0(FP), R0		// arg 1 - param
-	MOVW	psize+4(FP), R1		// arg 2 - psize
-	MOVW	$8, R12			// sys___tfork
-	INVOKE_SYSCALL
-
-	// Return if syscall failed.
-	B.CC	4(PC)
-	RSB	$0, R0
-	MOVW	R0, ret+20(FP)
-	RET
-
-	// In parent, return.
-	CMP	$0, R0
-	BEQ	3(PC)
-	MOVW	R0, ret+20(FP)
-	RET
-
-	// Initialise m, g.
-	MOVW	R5, g
-	MOVW	R4, g_m(g)
-
-	// Paranoia; check that stack splitting code works.
-	BL	runtime·emptyfunc(SB)
-
-	// Call fn.
-	BL	(R6)
-
-	// fn should never return.
-	MOVW	$2, R8			// crash if reached
-	MOVW	R8, (R8)
-	RET
-
-TEXT runtime·sigaltstack(SB),NOSPLIT,$0
-	MOVW	new+0(FP), R0		// arg 1 - new sigaltstack
-	MOVW	old+4(FP), R1		// arg 2 - old sigaltstack
-	MOVW	$288, R12		// sys_sigaltstack
-	INVOKE_SYSCALL
-	MOVW.CS	$0, R8			// crash on syscall failure
-	MOVW.CS	R8, (R8)
-	RET
-
-TEXT runtime·osyield(SB),NOSPLIT,$0
-	MOVW	$298, R12		// sys_sched_yield
-	INVOKE_SYSCALL
-	RET
-
-TEXT runtime·thrsleep(SB),NOSPLIT,$4
-	MOVW	ident+0(FP), R0		// arg 1 - ident
-	MOVW	clock_id+4(FP), R1	// arg 2 - clock_id
-	MOVW	tsp+8(FP), R2		// arg 3 - tsp
-	MOVW	lock+12(FP), R3		// arg 4 - lock
-	MOVW	abort+16(FP), R4	// arg 5 - abort (on stack)
-	MOVW	R4, 4(R13)
-	ADD	$4, R13
-	MOVW	$94, R12		// sys___thrsleep
-	INVOKE_SYSCALL
-	SUB	$4, R13
-	MOVW	R0, ret+20(FP)
-	RET
-
-TEXT runtime·thrwakeup(SB),NOSPLIT,$0
-	MOVW	ident+0(FP), R0		// arg 1 - ident
-	MOVW	n+4(FP), R1		// arg 2 - n
-	MOVW	$301, R12		// sys___thrwakeup
-	INVOKE_SYSCALL
-	MOVW	R0, ret+8(FP)
-	RET
-
-TEXT runtime·sysctl(SB),NOSPLIT,$8
-	MOVW	mib+0(FP), R0		// arg 1 - mib
-	MOVW	miblen+4(FP), R1	// arg 2 - miblen
-	MOVW	out+8(FP), R2		// arg 3 - out
-	MOVW	size+12(FP), R3		// arg 4 - size
-	MOVW	dst+16(FP), R4		// arg 5 - dest (on stack)
-	MOVW	R4, 4(R13)
-	MOVW	ndst+20(FP), R5		// arg 6 - newlen (on stack)
-	MOVW	R5, 8(R13)
-	ADD	$4, R13
-	MOVW	$202, R12		// sys___sysctl
-	INVOKE_SYSCALL
-	SUB	$4, R13
-	MOVW.CC	$0, R0
-	RSB.CS	$0, R0
-	MOVW	R0, ret+24(FP)
-	RET
-
-// int32 runtime·kqueue(void);
-TEXT runtime·kqueue(SB),NOSPLIT,$0
-	MOVW	$269, R12		// sys_kqueue
-	INVOKE_SYSCALL
-	RSB.CS	$0, R0
-	MOVW	R0, ret+0(FP)
-	RET
-
-// int32 runtime·kevent(int kq, Kevent *changelist, int nchanges, Kevent *eventlist, int nevents, Timespec *timeout);
-TEXT runtime·kevent(SB),NOSPLIT,$8
-	MOVW	kq+0(FP), R0		// arg 1 - kq
-	MOVW	ch+4(FP), R1		// arg 2 - changelist
-	MOVW	nch+8(FP), R2		// arg 3 - nchanges
-	MOVW	ev+12(FP), R3		// arg 4 - eventlist
-	MOVW	nev+16(FP), R4		// arg 5 - nevents (on stack)
-	MOVW	R4, 4(R13)
-	MOVW	ts+20(FP), R5		// arg 6 - timeout (on stack)
-	MOVW	R5, 8(R13)
-	ADD	$4, R13
-	MOVW	$72, R12		// sys_kevent
-	INVOKE_SYSCALL
-	RSB.CS	$0, R0
-	SUB	$4, R13
-	MOVW	R0, ret+24(FP)
-	RET
-
-// func closeonexec(fd int32)
-TEXT runtime·closeonexec(SB),NOSPLIT,$0
-	MOVW	fd+0(FP), R0		// arg 1 - fd
-	MOVW	$2, R1			// arg 2 - cmd (F_SETFD)
-	MOVW	$1, R2			// arg 3 - arg (FD_CLOEXEC)
-	MOVW	$92, R12		// sys_fcntl
-	INVOKE_SYSCALL
-	RET
-
-// func runtime·setNonblock(fd int32)
-TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
-	MOVW	fd+0(FP), R0	// fd
-	MOVW	$3, R1	// F_GETFL
-	MOVW	$0, R2
-	MOVW	$92, R12
-	INVOKE_SYSCALL
-	ORR	$0x4, R0, R2	// O_NONBLOCK
-	MOVW	fd+0(FP), R0	// fd
-	MOVW	$4, R1	// F_SETFL
-	MOVW	$92, R12
-	INVOKE_SYSCALL
-	RET
-
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
 	B	runtime·armPublicationBarrier(SB)
 
+// TODO(jsing): OpenBSD only supports GOARM=7 machines... this
+// should not be needed, however the linker still allows GOARM=5
+// on this platform.
 TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0
 	MOVM.WP	[R1, R2, R3, R12], (R13)
 	MOVW	$330, R12		// sys___get_tcb
 	INVOKE_SYSCALL
 	MOVM.IAW (R13), [R1, R2, R3, R12]
 	RET
+
+// These trampolines help convert from Go calling convention to C calling convention.
+// They should be called with asmcgocall - note that while asmcgocall does
+// stack alignment, creation of a frame undoes it again.
+// A pointer to the arguments is passed in R0.
+// A single int32 result is returned in R0.
+// (For more results, make an args/results structure.)
+TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R0		// arg 1 attr
+	CALL	libc_pthread_attr_init(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·pthread_attr_destroy_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R0		// arg 1 attr
+	CALL	libc_pthread_attr_destroy(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 size
+	MOVW	0(R0), R0		// arg 1 attr
+	CALL	libc_pthread_attr_getstacksize(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·pthread_attr_setdetachstate_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 state
+	MOVW	0(R0), R0		// arg 1 attr
+	CALL	libc_pthread_attr_setdetachstate(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·pthread_create_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$16, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R1		// arg 2 attr
+	MOVW	4(R0), R2		// arg 3 start
+	MOVW	8(R0), R3		// arg 4 arg
+	MOVW	R13, R0			// arg 1 &threadid (discarded)
+	CALL	libc_pthread_create(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·thrkill_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 - signal
+	MOVW	$0, R2			// arg 3 - tcb
+	MOVW	0(R0), R0		// arg 1 - tid
+	CALL	libc_thrkill(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·thrsleep_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$16, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 - clock_id
+	MOVW	8(R0), R2		// arg 3 - abstime
+	MOVW	12(R0), R3		// arg 4 - lock
+	MOVW	16(R0), R4		// arg 5 - abort (on stack)
+	MOVW	R4, 0(R13)
+	MOVW	0(R0), R0		// arg 1 - id
+	CALL	libc_thrsleep(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·thrwakeup_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 - count
+	MOVW	0(R0), R0		// arg 1 - id
+	CALL	libc_thrwakeup(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·exit_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R0		// arg 1 exit status
+	BL	libc_exit(SB)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·getthrid_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	MOVW	R0, R8
+	BIC     $0x7, R13		// align for ELF ABI
+	BL	libc_getthrid(SB)
+	MOVW	R0, 0(R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·raiseproc_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	R0, R4
+	BL	libc_getpid(SB)		// arg 1 pid
+	MOVW	R4, R1			// arg 2 signal
+	BL	libc_kill(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·sched_yield_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	BL	libc_sched_yield(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·mmap_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$16, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	R0, R8
+	MOVW	4(R0), R1		// arg 2 len
+	MOVW	8(R0), R2		// arg 3 prot
+	MOVW	12(R0), R3		// arg 4 flags
+	MOVW	16(R0), R4		// arg 5 fid (on stack)
+	MOVW	R4, 0(R13)
+	MOVW	$0, R5			// pad (on stack)
+	MOVW	R5, 4(R13)
+	MOVW	20(R0), R6		// arg 6 offset (on stack)
+	MOVW	R6, 8(R13)		// low 32 bits
+	MOVW    $0, R7
+	MOVW	R7, 12(R13)		// high 32 bits
+	MOVW	0(R0), R0		// arg 1 addr
+	BL	libc_mmap(SB)
+	MOVW	$0, R1
+	CMP	$-1, R0
+	BNE	ok
+	BL	libc_errno(SB)
+	MOVW	(R0), R1		// errno
+	MOVW	$0, R0
+ok:
+	MOVW	R0, 24(R8)
+	MOVW	R1, 28(R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·munmap_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 len
+	MOVW	0(R0), R0		// arg 1 addr
+	BL	libc_munmap(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·madvise_trampoline(SB), NOSPLIT, $0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 len
+	MOVW	8(R0), R2		// arg 3 advice
+	MOVW	0(R0), R0		// arg 1 addr
+	BL	libc_madvise(SB)
+	// ignore failure - maybe pages are locked
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·open_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 - flags
+	MOVW	8(R0), R2		// arg 3 - mode (vararg, on stack)
+	MOVW	R2, 0(R13)
+	MOVW	0(R0), R0		// arg 1 - path
+	MOVW	R13, R4
+	BIC     $0x7, R13		// align for ELF ABI
+	BL	libc_open(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·close_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R0		// arg 1 - fd
+	BL	libc_close(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·read_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 - buf
+	MOVW	8(R0), R2		// arg 3 - count
+	MOVW	0(R0), R0		// arg 1 - fd
+	BL	libc_read(SB)
+	CMP	$-1, R0
+	BNE	noerr
+	BL	libc_errno(SB)
+	MOVW	(R0), R0		// errno
+	RSB.CS	$0, R0			// caller expects negative errno
+noerr:
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·write_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 buf
+	MOVW	8(R0), R2		// arg 3 count
+	MOVW	0(R0), R0		// arg 1 fd
+	BL	libc_write(SB)
+	CMP	$-1, R0
+	BNE	noerr
+	BL	libc_errno(SB)
+	MOVW	(R0), R0		// errno
+	RSB.CS	$0, R0			// caller expects negative errno
+noerr:
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·pipe2_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 flags
+	MOVW	0(R0), R0		// arg 1 filedes
+	BL	libc_pipe2(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	BL	libc_errno(SB)
+	MOVW	(R0), R0		// errno
+	RSB.CS	$0, R0			// caller expects negative errno
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·setitimer_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 new
+	MOVW	8(R0), R2		// arg 3 old
+	MOVW	0(R0), R0		// arg 1 which
+	BL	libc_setitimer(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·usleep_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	0(R0), R0		// arg 1 usec
+	BL	libc_usleep(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·sysctl_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 miblen
+	MOVW	8(R0), R2		// arg 3 out
+	MOVW	12(R0), R3		// arg 4 size
+	MOVW	16(R0), R4		// arg 5 dst (on stack)
+	MOVW	R4, 0(R13)
+	MOVW	20(R0), R5		// arg 6 ndst (on stack)
+	MOVW	R5, 4(R13)
+	MOVW	0(R0), R0		// arg 1 mib
+	BL	libc_sysctl(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·kqueue_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	BL	libc_kqueue(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·kevent_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 keventt
+	MOVW	8(R0), R2		// arg 3 nch
+	MOVW	12(R0), R3		// arg 4 ev
+	MOVW	16(R0), R4		// arg 5 nev (on stack)
+	MOVW	R4, 0(R13)
+	MOVW	20(R0), R5		// arg 6 ts (on stack)
+	MOVW	R5, 4(R13)
+	MOVW	0(R0), R0		// arg 1 kq
+	BL	libc_kevent(SB)
+	CMP	$-1, R0
+	BNE	ok
+	BL	libc_errno(SB)
+	MOVW	(R0), R0		// errno
+	RSB.CS	$0, R0			// caller expects negative errno
+ok:
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·clock_gettime_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 tp
+	MOVW	0(R0), R0		// arg 1 clock_id
+	BL	libc_clock_gettime(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·fcntl_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 cmd
+	MOVW	8(R0), R2		// arg 3 arg (vararg, on stack)
+	MOVW	R2, 0(R13)
+	MOVW	0(R0), R0		// arg 1 fd
+	BL	libc_fcntl(SB)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·sigaction_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 new
+	MOVW	8(R0), R2		// arg 3 old
+	MOVW	0(R0), R0		// arg 1 sig
+	BL	libc_sigaction(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·sigprocmask_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 new
+	MOVW	8(R0), R2		// arg 3 old
+	MOVW	0(R0), R0		// arg 1 how
+	BL	libc_pthread_sigmask(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+TEXT runtime·sigaltstack_trampoline(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+	MOVW	4(R0), R1		// arg 2 old
+	MOVW	0(R0), R0		// arg 1 new
+	BL	libc_sigaltstack(SB)
+	CMP	$-1, R0
+	BNE	3(PC)
+	MOVW	$0, R8			// crash on failure
+	MOVW	R8, (R8)
+	MOVW	R9, R13
+	RET
+
+// syscall calls a function in libc on behalf of the syscall package.
+// syscall takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscall must be called on the g0 stack with the
+// C calling convention (use libcCall).
+//
+// syscall expects a 32-bit result and tests for 32-bit -1
+// to decide there was an error.
+TEXT runtime·syscall(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+
+	BL	(R7)
+
+	MOVW	R0, (4*4)(R8) // r1
+	MOVW	R1, (5*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (6*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
+
+// syscallX calls a function in libc on behalf of the syscall package.
+// syscallX takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscallX must be called on the g0 stack with the
+// C calling convention (use libcCall).
+//
+// syscallX is like syscall but expects a 64-bit result
+// and tests for 64-bit -1 to decide there was an error.
+TEXT runtime·syscallX(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+
+	BL	(R7)
+
+	MOVW	R0, (4*4)(R8) // r1
+	MOVW	R1, (5*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+	CMP	$-1, R1
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (6*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
+
+// syscall6 calls a function in libc on behalf of the syscall package.
+// syscall6 takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	a4    uintptr
+//	a5    uintptr
+//	a6    uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscall6 must be called on the g0 stack with the
+// C calling convention (use libcCall).
+//
+// syscall6 expects a 32-bit result and tests for 32-bit -1
+// to decide there was an error.
+TEXT runtime·syscall6(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+	MOVW	(4*4)(R8), R3 // a4
+	MOVW	(5*4)(R8), R4 // a5
+	MOVW	R4, 0(R13)
+	MOVW	(6*4)(R8), R5 // a6
+	MOVW	R5, 4(R13)
+
+	BL	(R7)
+
+	MOVW	R0, (7*4)(R8) // r1
+	MOVW	R1, (8*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (9*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
+
+// syscall6X calls a function in libc on behalf of the syscall package.
+// syscall6X takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	a4    uintptr
+//	a5    uintptr
+//	a6    uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscall6X must be called on the g0 stack with the
+// C calling convention (use libcCall).
+//
+// syscall6X is like syscall6 but expects a 64-bit result
+// and tests for 64-bit -1 to decide there was an error.
+TEXT runtime·syscall6X(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$8, R13
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+	MOVW	(4*4)(R8), R3 // a4
+	MOVW	(5*4)(R8), R4 // a5
+	MOVW	R4, 0(R13)
+	MOVW	(6*4)(R8), R5 // a6
+	MOVW	R5, 4(R13)
+
+	BL	(R7)
+
+	MOVW	R0, (7*4)(R8) // r1
+	MOVW	R1, (8*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+	CMP	$-1, R1
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (9*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
+
+// syscall10 calls a function in libc on behalf of the syscall package.
+// syscall10 takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	a4    uintptr
+//	a5    uintptr
+//	a6    uintptr
+//	a7    uintptr
+//	a8    uintptr
+//	a9    uintptr
+//	a10   uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscall10 must be called on the g0 stack with the
+// C calling convention (use libcCall).
+TEXT runtime·syscall10(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$24, R13
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+	MOVW	(4*4)(R8), R3 // a4
+	MOVW	(5*4)(R8), R4 // a5
+	MOVW	R4, 0(R13)
+	MOVW	(6*4)(R8), R5 // a6
+	MOVW	R5, 4(R13)
+	MOVW	(7*4)(R8), R6 // a7
+	MOVW	R6, 8(R13)
+	MOVW	(8*4)(R8), R4 // a8
+	MOVW	R4, 12(R13)
+	MOVW	(9*4)(R8), R5 // a9
+	MOVW	R5, 16(R13)
+	MOVW	(10*4)(R8), R6 // a10
+	MOVW	R6, 20(R13)
+
+	BL	(R7)
+
+	MOVW	R0, (11*4)(R8) // r1
+	MOVW	R1, (12*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (13*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
+
+// syscall10X calls a function in libc on behalf of the syscall package.
+// syscall10X takes a pointer to a struct like:
+// struct {
+//	fn    uintptr
+//	a1    uintptr
+//	a2    uintptr
+//	a3    uintptr
+//	a4    uintptr
+//	a5    uintptr
+//	a6    uintptr
+//	a7    uintptr
+//	a8    uintptr
+//	a9    uintptr
+//	a10   uintptr
+//	r1    uintptr
+//	r2    uintptr
+//	err   uintptr
+// }
+// syscall10X must be called on the g0 stack with the
+// C calling convention (use libcCall).
+//
+// syscall10X is like syscall10 but expects a 64-bit result
+// and tests for 64-bit -1 to decide there was an error.
+TEXT runtime·syscall10X(SB),NOSPLIT,$0
+	MOVW	R13, R9
+	SUB	$24, R13
+	BIC     $0x7, R13		// align for ELF ABI
+
+	MOVW	R0, R8
+
+	MOVW	(0*4)(R8), R7 // fn
+	MOVW	(1*4)(R8), R0 // a1
+	MOVW	(2*4)(R8), R1 // a2
+	MOVW	(3*4)(R8), R2 // a3
+	MOVW	(4*4)(R8), R3 // a4
+	MOVW	(5*4)(R8), R4 // a5
+	MOVW	R4, 0(R13)
+	MOVW	(6*4)(R8), R5 // a6
+	MOVW	R5, 4(R13)
+	MOVW	(7*4)(R8), R6 // a7
+	MOVW	R6, 8(R13)
+	MOVW	(8*4)(R8), R4 // a8
+	MOVW	R4, 12(R13)
+	MOVW	(9*4)(R8), R5 // a9
+	MOVW	R5, 16(R13)
+	MOVW	(10*4)(R8), R6 // a10
+	MOVW	R6, 20(R13)
+
+	BL	(R7)
+
+	MOVW	R0, (11*4)(R8) // r1
+	MOVW	R1, (12*4)(R8) // r2
+
+	// Standard libc functions return -1 on error and set errno.
+	CMP	$-1, R0
+	BNE	ok
+	CMP	$-1, R1
+	BNE	ok
+
+	// Get error code from libc.
+	BL	libc_errno(SB)
+	MOVW	(R0), R1
+	MOVW	R1, (13*4)(R8) // err
+
+ok:
+	MOVW	$0, R0		// no error (it's ignored anyway)
+	MOVW	R9, R13
+	RET
diff --git a/src/runtime/sys_plan9_386.s b/src/runtime/sys_plan9_386.s
index b3d2f1376d6..bdcb98e19e0 100644
--- a/src/runtime/sys_plan9_386.s
+++ b/src/runtime/sys_plan9_386.s
@@ -250,3 +250,7 @@ TEXT runtime·errstr(SB),NOSPLIT,$8-8
 	MOVL	0(SP), AX
 	MOVL	AX, ret_base+0(FP)
 	RET
+
+// never called on this platform
+TEXT ·sigpanictramp(SB),NOSPLIT,$0-0
+	UNDEF
diff --git a/src/runtime/sys_plan9_amd64.s b/src/runtime/sys_plan9_amd64.s
index 731306ab448..39fc4c68e4c 100644
--- a/src/runtime/sys_plan9_amd64.s
+++ b/src/runtime/sys_plan9_amd64.s
@@ -251,3 +251,7 @@ TEXT runtime·errstr(SB),NOSPLIT,$16-16
 	MOVQ	0(SP), AX
 	MOVQ	AX, ret_base+0(FP)
 	RET
+
+// never called on this platform
+TEXT ·sigpanictramp(SB),NOSPLIT,$0-0
+	UNDEF
diff --git a/src/runtime/sys_wasm.go b/src/runtime/sys_wasm.go
index 057ed4ccd90..e6e7f471eea 100644
--- a/src/runtime/sys_wasm.go
+++ b/src/runtime/sys_wasm.go
@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/sys"
 	"unsafe"
 )
@@ -30,7 +31,7 @@ func wasmExit(code int32)
 // and then stopped before the first instruction in fn.
 func gostartcall(buf *gobuf, fn, ctxt unsafe.Pointer) {
 	sp := buf.sp
-	sp -= sys.PtrSize
+	sp -= goarch.PtrSize
 	*(*uintptr)(unsafe.Pointer(sp)) = buf.pc
 	buf.sp = sp
 	buf.pc = uintptr(fn)
diff --git a/src/runtime/sys_windows_386.s b/src/runtime/sys_windows_386.s
index 0b3933502ab..cf3a439523c 100644
--- a/src/runtime/sys_windows_386.s
+++ b/src/runtime/sys_windows_386.s
@@ -8,7 +8,7 @@
 #include "time_windows.h"
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT,$0
+TEXT runtime·asmstdcall(SB),NOSPLIT,$0
 	MOVL	fn+0(FP), BX
 
 	// SetLastError(0).
@@ -147,21 +147,21 @@ done:
 	BYTE $0xC2; WORD $4
 	RET // unreached; make assembler happy
 
-TEXT runtime·exceptiontramp(SB),NOSPLIT,$0
+TEXT runtime·exceptiontramp(SB),NOSPLIT,$0
 	MOVL	$runtime·exceptionhandler(SB), AX
 	JMP	sigtramp<>(SB)
 
-TEXT runtime·firstcontinuetramp(SB),NOSPLIT,$0-0
+TEXT runtime·firstcontinuetramp(SB),NOSPLIT,$0-0
 	// is never called
 	INT	$3
 
-TEXT runtime·lastcontinuetramp(SB),NOSPLIT,$0-0
+TEXT runtime·lastcontinuetramp(SB),NOSPLIT,$0-0
 	MOVL	$runtime·lastcontinuehandler(SB), AX
 	JMP	sigtramp<>(SB)
 
 GLOBL runtime·cbctxts(SB), NOPTR, $4
 
-TEXT runtime·callbackasm1(SB),NOSPLIT,$0
+TEXT runtime·callbackasm1(SB),NOSPLIT,$0
   	MOVL	0(SP), AX	// will use to find our callback context
 
 	// remove return address from stack, we are not returning to callbackasm, but to its caller.
@@ -180,7 +180,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$0
 	CLD
 
 	// determine index into runtime·cbs table
-	SUBL	$runtime·callbackasm(SB), AX
+	SUBL	$runtime·callbackasm(SB), AX
 	MOVL	$0, DX
 	MOVL	$5, BX	// divide by 5 because each call instruction in runtime·callbacks is 5 bytes long
 	DIVL	BX
@@ -250,7 +250,7 @@ TEXT tstart<>(SB),NOSPLIT,$0
 	RET
 
 // uint32 tstart_stdcall(M *newm);
-TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
+TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
 	MOVL	newm+0(FP), BX
 
 	PUSHL	BX
diff --git a/src/runtime/sys_windows_amd64.s b/src/runtime/sys_windows_amd64.s
index e7782846b25..6cc5bba2b73 100644
--- a/src/runtime/sys_windows_amd64.s
+++ b/src/runtime/sys_windows_amd64.s
@@ -13,7 +13,7 @@
 #define maxargs 18
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
 	// asmcgocall will put first argument into CX.
 	PUSHQ	CX			// save for later
 	MOVQ	libcall_fn(CX), AX
@@ -179,15 +179,15 @@ done:
 
 	RET
 
-TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
 	MOVQ	$runtime·exceptionhandler(SB), AX
 	JMP	sigtramp<>(SB)
 
-TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
+TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
 	MOVQ	$runtime·firstcontinuehandler(SB), AX
 	JMP	sigtramp<>(SB)
 
-TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
+TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
 	MOVQ	$runtime·lastcontinuehandler(SB), AX
 	JMP	sigtramp<>(SB)
 
@@ -212,7 +212,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$0
 	ADDQ	$8, SP
 
 	// determine index into runtime·cbs table
-	MOVQ	$runtime·callbackasm(SB), DX
+	MOVQ	$runtime·callbackasm(SB), DX
 	SUBQ	DX, AX
 	MOVQ	$0, DX
 	MOVQ	$5, CX	// divide by 5 because each call instruction in runtime·callbacks is 5 bytes long
@@ -245,7 +245,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$0
 	RET
 
 // uint32 tstart_stdcall(M *newm);
-TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
+TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
 	// Switch from the host ABI to the Go ABI.
 	PUSH_REGS_HOST_TO_ABI0()
 
diff --git a/src/runtime/sys_windows_arm.s b/src/runtime/sys_windows_arm.s
index 48f8c7dedff..c9e96cb6522 100644
--- a/src/runtime/sys_windows_arm.s
+++ b/src/runtime/sys_windows_arm.s
@@ -10,7 +10,7 @@
 // Note: For system ABI, R0-R3 are args, R4-R11 are callee-save.
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
 	MOVM.DB.W [R4, R5, R14], (R13)	// push {r4, r5, lr}
 	MOVW	R0, R4			// put libcall * in r4
 	MOVW	R13, R5			// save stack pointer in r5
@@ -222,21 +222,21 @@ TEXT sigresume<>(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R0, R13
 	B	(R1)
 
-TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
 	MOVW	$runtime·exceptionhandler(SB), R1
 	B	sigtramp<>(SB)
 
-TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0
 	MOVW	$runtime·firstcontinuehandler(SB), R1
 	B	sigtramp<>(SB)
 
-TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0
 	MOVW	$runtime·lastcontinuehandler(SB), R1
 	B	sigtramp<>(SB)
 
 GLOBL runtime·cbctxts(SB), NOPTR, $4
 
-TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0
 	// On entry, the trampoline in zcallback_windows_arm.s left
 	// the callback index in R12 (which is volatile in the C ABI).
 
@@ -275,7 +275,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0
 	B	(R12)	// return
 
 // uint32 tstart_stdcall(M *newm);
-TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0
 	MOVM.DB.W [R4-R11, R14], (R13)		// push {r4-r11, lr}
 
 	MOVW	m_g0(R0), g
diff --git a/src/runtime/sys_windows_arm64.s b/src/runtime/sys_windows_arm64.s
index 7a2e11f5ae2..44145c53fb7 100644
--- a/src/runtime/sys_windows_arm64.s
+++ b/src/runtime/sys_windows_arm64.s
@@ -18,7 +18,7 @@
 // load_g and save_g (in tls_arm64.s) clobber R27 (REGTMP) and R0.
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
 	STP.W	(R29, R30), -32(RSP)	// allocate C ABI stack frame
 	STP	(R19, R20), 16(RSP) // save old R19, R20
 	MOVD	R0, R19	// save libcall pointer
@@ -290,21 +290,21 @@ TEXT sigresume<>(SB),NOSPLIT|NOFRAME,$0
 	MOVD	R0, RSP
 	B	(R1)
 
-TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
-	MOVD	$runtime·exceptionhandler(SB), R1
+TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
+	MOVD	$runtime·exceptionhandler(SB), R1
 	B	sigtramp<>(SB)
 
-TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0
-	MOVD	$runtime·firstcontinuehandler(SB), R1
+TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0
+	MOVD	$runtime·firstcontinuehandler(SB), R1
 	B	sigtramp<>(SB)
 
 TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0
-	MOVD	$runtime·lastcontinuehandler(SB), R1
+	MOVD	$runtime·lastcontinuehandler(SB), R1
 	B	sigtramp<>(SB)
 
 GLOBL runtime·cbctxts(SB), NOPTR, $4
 
-TEXT runtime·callbackasm1(SB),NOSPLIT,$208-0
+TEXT runtime·callbackasm1(SB),NOSPLIT,$208-0
 	NO_LOCAL_POINTERS
 
 	// On entry, the trampoline in zcallback_windows_arm64.s left
@@ -339,7 +339,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$208-0
 	MOVD	R0, callbackArgs_result(R13)	// result
 
 	// Call cgocallback, which will call callbackWrap(frame).
-	MOVD	$·callbackWrap(SB), R0	// PC of function to call
+	MOVD	$·callbackWrap(SB), R0	// PC of function to call, cgocallback takes an ABIInternal entry-point
 	MOVD	R13, R1	// frame (&callbackArgs{...})
 	MOVD	$0, R2	// context
 	MOVD	R0, (1*8)(RSP)
@@ -356,7 +356,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$208-0
 	RET
 
 // uint32 tstart_stdcall(M *newm);
-TEXT runtime·tstart_stdcall(SB),NOSPLIT,$96-0
+TEXT runtime·tstart_stdcall(SB),NOSPLIT,$96-0
 	SAVE_R19_TO_R28(-10*8)
 
 	MOVD	m_g0(R0), g
diff --git a/src/runtime/sys_x86.go b/src/runtime/sys_x86.go
index 0866e3140e0..856c73a2f6c 100644
--- a/src/runtime/sys_x86.go
+++ b/src/runtime/sys_x86.go
@@ -8,7 +8,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -16,7 +16,7 @@ import (
 // and then stopped before the first instruction in fn.
 func gostartcall(buf *gobuf, fn, ctxt unsafe.Pointer) {
 	sp := buf.sp
-	sp -= sys.PtrSize
+	sp -= goarch.PtrSize
 	*(*uintptr)(unsafe.Pointer(sp)) = buf.pc
 	buf.sp = sp
 	buf.pc = uintptr(fn)
diff --git a/src/runtime/syscall_solaris.go b/src/runtime/syscall_solaris.go
index 094516927f3..15be8e1c61a 100644
--- a/src/runtime/syscall_solaris.go
+++ b/src/runtime/syscall_solaris.go
@@ -35,6 +35,7 @@ func pipe1() // declared for vet; do NOT call
 
 //go:nosplit
 //go:linkname syscall_sysvicall6
+//go:cgo_unsafe_args
 func syscall_sysvicall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
 	call := libcall{
 		fn:   fn,
@@ -49,6 +50,7 @@ func syscall_sysvicall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err
 
 //go:nosplit
 //go:linkname syscall_rawsysvicall6
+//go:cgo_unsafe_args
 func syscall_rawsysvicall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
 	call := libcall{
 		fn:   fn,
@@ -104,6 +106,7 @@ func syscall_dup2(oldfd, newfd uintptr) (val, err uintptr) {
 
 //go:nosplit
 //go:linkname syscall_execve
+//go:cgo_unsafe_args
 func syscall_execve(path, argv, envp uintptr) (err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_execve)),
@@ -123,6 +126,7 @@ func syscall_exit(code uintptr) {
 
 //go:nosplit
 //go:linkname syscall_fcntl
+//go:cgo_unsafe_args
 func syscall_fcntl(fd, cmd, arg uintptr) (val, err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_fcntl)),
@@ -181,6 +185,7 @@ func syscall_getpid() (pid, err uintptr) {
 
 //go:nosplit
 //go:linkname syscall_ioctl
+//go:cgo_unsafe_args
 func syscall_ioctl(fd, req, arg uintptr) (err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_ioctl)),
@@ -234,6 +239,7 @@ func syscall_setgid(gid uintptr) (err uintptr) {
 
 //go:nosplit
 //go:linkname syscall_setgroups
+//go:cgo_unsafe_args
 func syscall_setgroups(ngid, gid uintptr) (err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_setgroups)),
@@ -270,6 +276,7 @@ func syscall_setuid(uid uintptr) (err uintptr) {
 
 //go:nosplit
 //go:linkname syscall_setpgid
+//go:cgo_unsafe_args
 func syscall_setpgid(pid, pgid uintptr) (err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_setpgid)),
@@ -281,6 +288,7 @@ func syscall_setpgid(pid, pgid uintptr) (err uintptr) {
 }
 
 //go:linkname syscall_syscall
+//go:cgo_unsafe_args
 func syscall_syscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_syscall)),
@@ -294,6 +302,7 @@ func syscall_syscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 }
 
 //go:linkname syscall_wait4
+//go:cgo_unsafe_args
 func syscall_wait4(pid uintptr, wstatus *uint32, options uintptr, rusage unsafe.Pointer) (wpid int, err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_wait4)),
@@ -308,6 +317,7 @@ func syscall_wait4(pid uintptr, wstatus *uint32, options uintptr, rusage unsafe.
 
 //go:nosplit
 //go:linkname syscall_write
+//go:cgo_unsafe_args
 func syscall_write(fd, buf, nbyte uintptr) (n, err uintptr) {
 	call := libcall{
 		fn:   uintptr(unsafe.Pointer(&libc_write)),
diff --git a/src/runtime/syscall_windows.go b/src/runtime/syscall_windows.go
index 6b9195bcd52..e872d74e97f 100644
--- a/src/runtime/syscall_windows.go
+++ b/src/runtime/syscall_windows.go
@@ -6,7 +6,7 @@ package runtime
 
 import (
 	"internal/abi"
-	"runtime/internal/sys"
+	"internal/goarch"
 	"unsafe"
 )
 
@@ -64,6 +64,7 @@ type abiDesc struct {
 
 	srcStackSize uintptr // stdcall/fastcall stack space tracking
 	dstStackSize uintptr // Go stack space used
+	dstSpill     uintptr // Extra stack space for argument spill slots
 	dstRegisters int     // Go ABI int argument registers used
 
 	// retOffset is the offset of the uintptr-sized result in the Go
@@ -72,7 +73,7 @@ type abiDesc struct {
 }
 
 func (p *abiDesc) assignArg(t *_type) {
-	if t.size > sys.PtrSize {
+	if t.size > goarch.PtrSize {
 		// We don't support this right now. In
 		// stdcall/cdecl, 64-bit ints and doubles are
 		// passed as two words (little endian); and
@@ -110,7 +111,14 @@ func (p *abiDesc) assignArg(t *_type) {
 	// arguments. The same is true on arm.
 
 	oldParts := p.parts
-	if !p.tryRegAssignArg(t, 0) {
+	if p.tryRegAssignArg(t, 0) {
+		// Account for spill space.
+		//
+		// TODO(mknyszek): Remove this when we no longer have
+		// caller reserved spill space.
+		p.dstSpill = alignUp(p.dstSpill, uintptr(t.align))
+		p.dstSpill += t.size
+	} else {
 		// Register assignment failed.
 		// Undo the work and stack assign.
 		p.parts = oldParts
@@ -138,7 +146,7 @@ func (p *abiDesc) assignArg(t *_type) {
 
 	// cdecl, stdcall, fastcall, and arm pad arguments to word size.
 	// TODO(rsc): On arm and arm64 do we need to skip the caller's saved LR?
-	p.srcStackSize += sys.PtrSize
+	p.srcStackSize += goarch.PtrSize
 }
 
 // tryRegAssignArg tries to register-assign a value of type t.
@@ -154,7 +162,7 @@ func (p *abiDesc) tryRegAssignArg(t *_type, offset uintptr) bool {
 		return p.assignReg(t.size, offset)
 	case kindInt64, kindUint64:
 		// Only register-assign if the registers are big enough.
-		if sys.PtrSize == 8 {
+		if goarch.PtrSize == 8 {
 			return p.assignReg(t.size, offset)
 		}
 	case kindArray:
@@ -224,10 +232,10 @@ func callbackasmAddr(i int) uintptr {
 		// followed by a branch instruction
 		entrySize = 8
 	}
-	return funcPC(callbackasm) + uintptr(i*entrySize)
+	return abi.FuncPCABI0(callbackasm) + uintptr(i*entrySize)
 }
 
-const callbackMaxFrame = 64 * sys.PtrSize
+const callbackMaxFrame = 64 * goarch.PtrSize
 
 // compileCallback converts a Go function fn into a C function pointer
 // that can be passed to Windows APIs.
@@ -255,13 +263,13 @@ func compileCallback(fn eface, cdecl bool) (code uintptr) {
 	}
 	// The Go ABI aligns the result to the word size. src is
 	// already aligned.
-	abiMap.dstStackSize = alignUp(abiMap.dstStackSize, sys.PtrSize)
+	abiMap.dstStackSize = alignUp(abiMap.dstStackSize, goarch.PtrSize)
 	abiMap.retOffset = abiMap.dstStackSize
 
 	if len(ft.out()) != 1 {
 		panic("compileCallback: expected function with one uintptr-sized result")
 	}
-	if ft.out()[0].size != sys.PtrSize {
+	if ft.out()[0].size != goarch.PtrSize {
 		panic("compileCallback: expected function with one uintptr-sized result")
 	}
 	if k := ft.out()[0].kind & kindMask; k == kindFloat32 || k == kindFloat64 {
@@ -274,10 +282,14 @@ func compileCallback(fn eface, cdecl bool) (code uintptr) {
 		// Make room for the uintptr-sized result.
 		// If there are argument registers, the return value will
 		// be passed in the first register.
-		abiMap.dstStackSize += sys.PtrSize
+		abiMap.dstStackSize += goarch.PtrSize
 	}
 
-	if abiMap.dstStackSize > callbackMaxFrame {
+	// TODO(mknyszek): Remove dstSpill from this calculation when we no longer have
+	// caller reserved spill space.
+	frameSize := alignUp(abiMap.dstStackSize, goarch.PtrSize)
+	frameSize += abiMap.dstSpill
+	if frameSize > callbackMaxFrame {
 		panic("compileCallback: function argument frame too large")
 	}
 
@@ -356,9 +368,14 @@ func callbackWrap(a *callbackArgs) {
 		}
 	}
 
+	// TODO(mknyszek): Remove this when we no longer have
+	// caller reserved spill space.
+	frameSize := alignUp(c.abiMap.dstStackSize, goarch.PtrSize)
+	frameSize += c.abiMap.dstSpill
+
 	// Even though this is copying back results, we can pass a nil
 	// type because those results must not require write barriers.
-	reflectcall(nil, unsafe.Pointer(c.fn), noescape(goArgs), uint32(c.abiMap.dstStackSize), uint32(c.abiMap.retOffset), uint32(c.abiMap.dstStackSize), ®s)
+	reflectcall(nil, unsafe.Pointer(c.fn), noescape(goArgs), uint32(c.abiMap.dstStackSize), uint32(c.abiMap.retOffset), uint32(frameSize), ®s)
 
 	// Extract the result.
 	//
diff --git a/src/runtime/syscall_windows_test.go b/src/runtime/syscall_windows_test.go
index 5e9694d444c..e3f772ac4bb 100644
--- a/src/runtime/syscall_windows_test.go
+++ b/src/runtime/syscall_windows_test.go
@@ -389,6 +389,10 @@ var cbFuncs = []cbFunc{
 	{func(i1, i2, i3, i4, i5 uint8Pair) uintptr {
 		return uintptr(i1.x + i1.y + i2.x + i2.y + i3.x + i3.y + i4.x + i4.y + i5.x + i5.y)
 	}},
+	{func(i1, i2, i3, i4, i5, i6, i7, i8, i9 uint32) uintptr {
+		runtime.GC()
+		return uintptr(i1 + i2 + i3 + i4 + i5 + i6 + i7 + i8 + i9)
+	}},
 }
 
 //go:registerparams
@@ -461,6 +465,16 @@ func sum5andPair(i1, i2, i3, i4, i5 uint8Pair) uintptr {
 	return uintptr(i1.x + i1.y + i2.x + i2.y + i3.x + i3.y + i4.x + i4.y + i5.x + i5.y)
 }
 
+// This test forces a GC. The idea is to have enough arguments
+// that insufficient spill slots allocated (according to the ABI)
+// may cause compiler-generated spills to clobber the return PC.
+// Then, the GC stack scanning will catch that.
+//go:registerparams
+func sum9andGC(i1, i2, i3, i4, i5, i6, i7, i8, i9 uint32) uintptr {
+	runtime.GC()
+	return uintptr(i1 + i2 + i3 + i4 + i5 + i6 + i7 + i8 + i9)
+}
+
 // TODO(register args): Remove this once we switch to using the register
 // calling convention by default, since this is redundant with the existing
 // tests.
@@ -479,6 +493,7 @@ var cbFuncsRegABI = []cbFunc{
 	{sum9int8},
 	{sum5mix},
 	{sum5andPair},
+	{sum9andGC},
 }
 
 func getCallbackTestFuncs() []cbFunc {
diff --git a/src/runtime/testdata/testprog/checkptr.go b/src/runtime/testdata/testprog/checkptr.go
index e0a2794f4c1..9c5561396e5 100644
--- a/src/runtime/testdata/testprog/checkptr.go
+++ b/src/runtime/testdata/testprog/checkptr.go
@@ -4,15 +4,22 @@
 
 package main
 
-import "unsafe"
+import (
+	"runtime"
+	"time"
+	"unsafe"
+)
 
 func init() {
 	register("CheckPtrAlignmentNoPtr", CheckPtrAlignmentNoPtr)
 	register("CheckPtrAlignmentPtr", CheckPtrAlignmentPtr)
+	register("CheckPtrAlignmentNilPtr", CheckPtrAlignmentNilPtr)
 	register("CheckPtrArithmetic", CheckPtrArithmetic)
 	register("CheckPtrArithmetic2", CheckPtrArithmetic2)
 	register("CheckPtrSize", CheckPtrSize)
 	register("CheckPtrSmall", CheckPtrSmall)
+	register("CheckPtrSliceOK", CheckPtrSliceOK)
+	register("CheckPtrSliceFail", CheckPtrSliceFail)
 }
 
 func CheckPtrAlignmentNoPtr() {
@@ -27,6 +34,35 @@ func CheckPtrAlignmentPtr() {
 	sink2 = (**int64)(unsafe.Pointer(uintptr(p) + 1))
 }
 
+// CheckPtrAlignmentNilPtr tests that checkptrAlignment doesn't crash
+// on nil pointers (#47430).
+func CheckPtrAlignmentNilPtr() {
+	var do func(int)
+	do = func(n int) {
+		// Inflate the stack so runtime.shrinkstack gets called during GC
+		if n > 0 {
+			do(n - 1)
+		}
+
+		var p unsafe.Pointer
+		_ = (*int)(p)
+	}
+
+	go func() {
+		for {
+			runtime.GC()
+		}
+	}()
+
+	go func() {
+		for i := 0; ; i++ {
+			do(i % 1024)
+		}
+	}()
+
+	time.Sleep(time.Second)
+}
+
 func CheckPtrArithmetic() {
 	var x int
 	i := uintptr(unsafe.Pointer(&x))
@@ -49,3 +85,14 @@ func CheckPtrSize() {
 func CheckPtrSmall() {
 	sink2 = unsafe.Pointer(uintptr(1))
 }
+
+func CheckPtrSliceOK() {
+	p := new([4]int64)
+	sink2 = unsafe.Slice(&p[1], 3)
+}
+
+func CheckPtrSliceFail() {
+	p := new(int64)
+	sink2 = p
+	sink2 = unsafe.Slice(p, 100)
+}
diff --git a/src/runtime/testdata/testprogcgo/aprof.go b/src/runtime/testdata/testprogcgo/aprof.go
index aabca9e1ebd..44a15b08650 100644
--- a/src/runtime/testdata/testprogcgo/aprof.go
+++ b/src/runtime/testdata/testprogcgo/aprof.go
@@ -10,7 +10,7 @@ package main
 // The test fails when the function is the first C function.
 // The exported functions are the first C functions, so we use that.
 
-// extern void GoNop();
+// extern void CallGoNop();
 import "C"
 
 import (
@@ -38,7 +38,7 @@ func CgoCCodeSIGPROF() {
 					break
 				}
 			}
-			C.GoNop()
+			C.CallGoNop()
 		}
 		c <- true
 	}()
diff --git a/src/runtime/testdata/testprogcgo/aprof_c.c b/src/runtime/testdata/testprogcgo/aprof_c.c
new file mode 100644
index 00000000000..d588e13045f
--- /dev/null
+++ b/src/runtime/testdata/testprogcgo/aprof_c.c
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "_cgo_export.h"
+
+void CallGoNop() {
+	GoNop();
+}
diff --git a/src/runtime/testdata/testprogcgo/bigstack1_windows.c b/src/runtime/testdata/testprogcgo/bigstack1_windows.c
new file mode 100644
index 00000000000..551fb683093
--- /dev/null
+++ b/src/runtime/testdata/testprogcgo/bigstack1_windows.c
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is not in bigstack_windows.c because it needs to be part of
+// testprogcgo but is not part of the DLL built from bigstack_windows.c.
+
+#include "_cgo_export.h"
+
+void CallGoBigStack1(char* p) {
+	goBigStack1(p);
+}
diff --git a/src/runtime/testdata/testprogcgo/bigstack_windows.go b/src/runtime/testdata/testprogcgo/bigstack_windows.go
index f58fcf993f0..135b5fcfe04 100644
--- a/src/runtime/testdata/testprogcgo/bigstack_windows.go
+++ b/src/runtime/testdata/testprogcgo/bigstack_windows.go
@@ -6,7 +6,7 @@ package main
 
 /*
 typedef void callback(char*);
-extern void goBigStack1(char*);
+extern void CallGoBigStack1(char*);
 extern void bigStack(callback*);
 */
 import "C"
@@ -18,7 +18,7 @@ func init() {
 func BigStack() {
 	// Create a large thread stack and call back into Go to test
 	// if Go correctly determines the stack bounds.
-	C.bigStack((*C.callback)(C.goBigStack1))
+	C.bigStack((*C.callback)(C.CallGoBigStack1))
 }
 
 //export goBigStack1
diff --git a/src/runtime/testdata/testprogcgo/tracebackctxt.go b/src/runtime/testdata/testprogcgo/tracebackctxt.go
index 51fa4ad25c3..62ff8eccd67 100644
--- a/src/runtime/testdata/testprogcgo/tracebackctxt.go
+++ b/src/runtime/testdata/testprogcgo/tracebackctxt.go
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// The __attribute__((weak)) used below doesn't seem to work on Windows.
-
 package main
 
 // Test the context argument to SetCgoTraceback.
@@ -14,20 +12,24 @@ package main
 extern void C1(void);
 extern void C2(void);
 extern void tcContext(void*);
+extern void tcContextSimple(void*);
 extern void tcTraceback(void*);
 extern void tcSymbolizer(void*);
 extern int getContextCount(void);
+extern void TracebackContextPreemptionCallGo(int);
 */
 import "C"
 
 import (
 	"fmt"
 	"runtime"
+	"sync"
 	"unsafe"
 )
 
 func init() {
 	register("TracebackContext", TracebackContext)
+	register("TracebackContextPreemption", TracebackContextPreemption)
 }
 
 var tracebackOK bool
@@ -105,3 +107,30 @@ wantLoop:
 		tracebackOK = false
 	}
 }
+
+// Issue 47441.
+func TracebackContextPreemption() {
+	runtime.SetCgoTraceback(0, unsafe.Pointer(C.tcTraceback), unsafe.Pointer(C.tcContextSimple), unsafe.Pointer(C.tcSymbolizer))
+
+	const funcs = 10
+	const calls = 1e5
+	var wg sync.WaitGroup
+	for i := 0; i < funcs; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			for j := 0; j < calls; j++ {
+				C.TracebackContextPreemptionCallGo(C.int(i*calls + j))
+			}
+		}(i)
+	}
+	wg.Wait()
+
+	fmt.Println("OK")
+}
+
+//export TracebackContextPreemptionGoFunction
+func TracebackContextPreemptionGoFunction(i C.int) {
+	// Do some busy work.
+	fmt.Sprintf("%d\n", i)
+}
diff --git a/src/runtime/testdata/testprogcgo/tracebackctxt_c.c b/src/runtime/testdata/testprogcgo/tracebackctxt_c.c
index 900cada0d3d..910cb7b8997 100644
--- a/src/runtime/testdata/testprogcgo/tracebackctxt_c.c
+++ b/src/runtime/testdata/testprogcgo/tracebackctxt_c.c
@@ -11,6 +11,7 @@
 // Functions exported from Go.
 extern void G1(void);
 extern void G2(void);
+extern void TracebackContextPreemptionGoFunction(int);
 
 void C1() {
 	G1();
@@ -62,10 +63,17 @@ void tcContext(void* parg) {
 	}
 }
 
+void tcContextSimple(void* parg) {
+	struct cgoContextArg* arg = (struct cgoContextArg*)(parg);
+	if (arg->context == 0) {
+		arg->context = 1;
+	}
+}
+
 void tcTraceback(void* parg) {
 	int base, i;
 	struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
-	if (arg->context == 0) {
+	if (arg->context == 0 && arg->sigContext == 0) {
 		// This shouldn't happen in this program.
 		abort();
 	}
@@ -89,3 +97,7 @@ void tcSymbolizer(void *parg) {
 	arg->func = "cFunction";
 	arg->lineno = arg->pc + (arg->more << 16);
 }
+
+void TracebackContextPreemptionCallGo(int i) {
+	TracebackContextPreemptionGoFunction(i);
+}
diff --git a/src/runtime/testdata/testwinlibsignal/main.c b/src/runtime/testdata/testwinlibsignal/main.c
index 1787fef3b94..37f24823e66 100644
--- a/src/runtime/testdata/testwinlibsignal/main.c
+++ b/src/runtime/testdata/testwinlibsignal/main.c
@@ -19,13 +19,13 @@ int main(void)
 {
     waitForCtrlBreakEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
     if (!waitForCtrlBreakEvent) {
-        fprintf(stderr, "ERROR: Could not create event");
+        fprintf(stderr, "ERROR: Could not create event\n");
         return 1;
     }
 
     if (!SetConsoleCtrlHandler(CtrlHandler, TRUE))
     {
-        fprintf(stderr, "ERROR: Could not set control handler");
+        fprintf(stderr, "ERROR: Could not set control handler\n");
         return 1;
     }
 
@@ -34,7 +34,14 @@ int main(void)
     // This way the library handler gets called first.
     HMODULE dummyDll = LoadLibrary("dummy.dll");
     if (!dummyDll) {
-        fprintf(stderr, "ERROR: Could not load dummy.dll");
+        fprintf(stderr, "ERROR: Could not load dummy.dll\n");
+        return 1;
+    }
+
+    // Call the Dummy function so that Go initialization completes, since
+    // all cgo entry points call out to _cgo_wait_runtime_init_done.
+    if (((int(*)(void))GetProcAddress(dummyDll, "Dummy"))() != 42) {
+        fprintf(stderr, "ERROR: Dummy function did not return 42\n");
         return 1;
     }
 
@@ -42,7 +49,7 @@ int main(void)
     fflush(stdout);
 
     if (WaitForSingleObject(waitForCtrlBreakEvent, 5000) != WAIT_OBJECT_0) {
-        fprintf(stderr, "FAILURE: No signal received");
+        fprintf(stderr, "FAILURE: No signal received\n");
         return 1;
     }
 
diff --git a/src/runtime/textflag.h b/src/runtime/textflag.h
index e727208cd03..214075e360c 100644
--- a/src/runtime/textflag.h
+++ b/src/runtime/textflag.h
@@ -32,8 +32,8 @@
 #define NOFRAME 512
 // Function can call reflect.Type.Method or reflect.Type.MethodByName.
 #define REFLECTMETHOD 1024
-// Function is the top of the call stack. Call stack unwinders should stop
-// at this function.
+// Function is the outermost frame of the call stack. Call stack unwinders
+// should stop at this function.
 #define TOPFRAME 2048
 // Function is an ABI wrapper.
 #define ABIWRAPPER 4096
diff --git a/src/runtime/time.go b/src/runtime/time.go
index dee6a674e4c..ad267c33656 100644
--- a/src/runtime/time.go
+++ b/src/runtime/time.go
@@ -7,6 +7,7 @@
 package runtime
 
 import (
+	"internal/abi"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -333,7 +334,6 @@ func deltimer(t *timer) bool {
 				// Must fetch t.pp before setting status
 				// to timerDeleted.
 				tpp := t.pp.ptr()
-				atomic.Xadd(&tpp.adjustTimers, -1)
 				if !atomic.Cas(&t.status, timerModifying, timerDeleted) {
 					badTimer()
 				}
@@ -510,20 +510,9 @@ loop:
 
 		tpp := t.pp.ptr()
 
-		// Update the adjustTimers field.  Subtract one if we
-		// are removing a timerModifiedEarlier, add one if we
-		// are adding a timerModifiedEarlier.
-		adjust := int32(0)
-		if status == timerModifiedEarlier {
-			adjust--
-		}
 		if newStatus == timerModifiedEarlier {
-			adjust++
 			updateTimerModifiedEarliest(tpp, when)
 		}
-		if adjust != 0 {
-			atomic.Xadd(&tpp.adjustTimers, adjust)
-		}
 
 		// Set the new status of the timer.
 		if !atomic.Cas(&t.status, timerModifying, newStatus) {
@@ -591,9 +580,6 @@ func cleantimers(pp *p) {
 			// Move t to the right position.
 			dodeltimer0(pp)
 			doaddtimer(pp, t)
-			if s == timerModifiedEarlier {
-				atomic.Xadd(&pp.adjustTimers, -1)
-			}
 			if !atomic.Cas(&t.status, timerMoving, timerWaiting) {
 				badTimer()
 			}
@@ -664,37 +650,23 @@ func moveTimers(pp *p, timers []*timer) {
 // it also moves timers that have been modified to run later,
 // and removes deleted timers. The caller must have locked the timers for pp.
 func adjusttimers(pp *p, now int64) {
-	if atomic.Load(&pp.adjustTimers) == 0 {
-		if verifyTimers {
-			verifyTimerHeap(pp)
-		}
-		// There are no timers to adjust, so it is safe to clear
-		// timerModifiedEarliest. Do so in case it is stale.
-		// Everything will work if we don't do this,
-		// but clearing here may save future calls to adjusttimers.
-		atomic.Store64(&pp.timerModifiedEarliest, 0)
-		return
-	}
-
 	// If we haven't yet reached the time of the first timerModifiedEarlier
 	// timer, don't do anything. This speeds up programs that adjust
 	// a lot of timers back and forth if the timers rarely expire.
 	// We'll postpone looking through all the adjusted timers until
 	// one would actually expire.
-	if first := atomic.Load64(&pp.timerModifiedEarliest); first != 0 {
-		if int64(first) > now {
-			if verifyTimers {
-				verifyTimerHeap(pp)
-			}
-			return
+	first := atomic.Load64(&pp.timerModifiedEarliest)
+	if first == 0 || int64(first) > now {
+		if verifyTimers {
+			verifyTimerHeap(pp)
 		}
-
-		// We are going to clear all timerModifiedEarlier timers.
-		atomic.Store64(&pp.timerModifiedEarliest, 0)
+		return
 	}
 
+	// We are going to clear all timerModifiedEarlier timers.
+	atomic.Store64(&pp.timerModifiedEarliest, 0)
+
 	var moved []*timer
-loop:
 	for i := 0; i < len(pp.timers); i++ {
 		t := pp.timers[i]
 		if t.pp.ptr() != pp {
@@ -721,11 +693,6 @@ loop:
 				// loop to skip some other timer.
 				dodeltimer(pp, i)
 				moved = append(moved, t)
-				if s == timerModifiedEarlier {
-					if n := atomic.Xadd(&pp.adjustTimers, -1); int32(n) <= 0 {
-						break loop
-					}
-				}
 				// Look at this heap position again.
 				i--
 			}
@@ -824,9 +791,6 @@ func runtimer(pp *p, now int64) int64 {
 			t.when = t.nextwhen
 			dodeltimer0(pp)
 			doaddtimer(pp, t)
-			if s == timerModifiedEarlier {
-				atomic.Xadd(&pp.adjustTimers, -1)
-			}
 			if !atomic.Cas(&t.status, timerMoving, timerWaiting) {
 				badTimer()
 			}
@@ -856,7 +820,7 @@ func runOneTimer(pp *p, t *timer, now int64) {
 	if raceenabled {
 		ppcur := getg().m.p.ptr()
 		if ppcur.timerRaceCtx == 0 {
-			ppcur.timerRaceCtx = racegostart(funcPC(runtimer) + sys.PCQuantum)
+			ppcur.timerRaceCtx = racegostart(abi.FuncPCABIInternal(runtimer) + sys.PCQuantum)
 		}
 		raceacquirectx(ppcur.timerRaceCtx, unsafe.Pointer(t))
 	}
@@ -921,7 +885,6 @@ func clearDeletedTimers(pp *p) {
 	atomic.Store64(&pp.timerModifiedEarliest, 0)
 
 	cdel := int32(0)
-	cearlier := int32(0)
 	to := 0
 	changedHeap := false
 	timers := pp.timers
@@ -946,9 +909,6 @@ nextTimer:
 					if !atomic.Cas(&t.status, timerMoving, timerWaiting) {
 						badTimer()
 					}
-					if s == timerModifiedEarlier {
-						cearlier++
-					}
 					continue nextTimer
 				}
 			case timerDeleted:
@@ -985,7 +945,6 @@ nextTimer:
 
 	atomic.Xadd(&pp.deletedTimers, -cdel)
 	atomic.Xadd(&pp.numTimers, -cdel)
-	atomic.Xadd(&pp.adjustTimers, -cearlier)
 
 	timers = timers[:to]
 	pp.timers = timers
diff --git a/src/runtime/time_linux_amd64.s b/src/runtime/time_linux_amd64.s
index 0dd79198968..c88e92bd0ca 100644
--- a/src/runtime/time_linux_amd64.s
+++ b/src/runtime/time_linux_amd64.s
@@ -15,13 +15,7 @@
 TEXT time·now(SB),NOSPLIT,$16-24
 	MOVQ	SP, R12 // Save old SP; R12 unchanged by C code.
 
-#ifdef GOEXPERIMENT_regabig
 	MOVQ	g_m(R14), BX // BX unchanged by C code.
-#else
-	get_tls(CX)
-	MOVQ	g(CX), AX
-	MOVQ	g_m(AX), BX // BX unchanged by C code.
-#endif
 
 	// Store CLOCK_REALTIME results directly to return space.
 	LEAQ	sec+0(FP), SI
@@ -38,11 +32,7 @@ TEXT time·now(SB),NOSPLIT,$16-24
 	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	SI, m_vdsoSP(BX)
 
-#ifdef GOEXPERIMENT_regabig
 	CMPQ	R14, m_curg(BX)	// Only switch if on curg.
-#else
-	CMPQ	AX, m_curg(BX)	// Only switch if on curg.
-#endif
 	JNE	noswitch
 
 	MOVQ	m_g0(BX), DX
diff --git a/src/runtime/tls_arm.s b/src/runtime/tls_arm.s
index e42de8deb4f..879caac9e16 100644
--- a/src/runtime/tls_arm.s
+++ b/src/runtime/tls_arm.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !windows
 // +build !windows
 
 #include "go_asm.h"
diff --git a/src/runtime/tls_mips64x.s b/src/runtime/tls_mips64x.s
index 888c0efec6a..779d64ba31a 100644
--- a/src/runtime/tls_mips64x.s
+++ b/src/runtime/tls_mips64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 #include "go_asm.h"
diff --git a/src/runtime/tls_mipsx.s b/src/runtime/tls_mipsx.s
index d2ffcd954c9..ada8d06a9e7 100644
--- a/src/runtime/tls_mipsx.s
+++ b/src/runtime/tls_mipsx.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 #include "go_asm.h"
diff --git a/src/runtime/tls_ppc64x.s b/src/runtime/tls_ppc64x.s
index 25d796fcc6e..7e935d0eb29 100644
--- a/src/runtime/tls_ppc64x.s
+++ b/src/runtime/tls_ppc64x.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 #include "go_asm.h"
diff --git a/src/runtime/trace.go b/src/runtime/trace.go
index 1530178c853..00544e4283c 100644
--- a/src/runtime/trace.go
+++ b/src/runtime/trace.go
@@ -13,6 +13,7 @@
 package runtime
 
 import (
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -85,7 +86,7 @@ const (
 	// and ppc64le.
 	// Tracing won't work reliably for architectures where cputicks is emulated
 	// by nanotime, so the value doesn't matter for those architectures.
-	traceTickDiv = 16 + 48*(sys.Goarch386|sys.GoarchAmd64)
+	traceTickDiv = 16 + 48*(goarch.Is386|goarch.IsAmd64)
 	// Maximum number of PCs in a single stack trace.
 	// Since events contain only stack id rather than whole stack trace,
 	// we can allow quite large values here.
@@ -829,7 +830,7 @@ Search:
 
 // newStack allocates a new stack of size n.
 func (tab *traceStackTable) newStack(n int) *traceStack {
-	return (*traceStack)(tab.mem.alloc(unsafe.Sizeof(traceStack{}) + uintptr(n)*sys.PtrSize))
+	return (*traceStack)(tab.mem.alloc(unsafe.Sizeof(traceStack{}) + uintptr(n)*goarch.PtrSize))
 }
 
 // allFrames returns all of the Frames corresponding to pcs.
@@ -929,7 +930,7 @@ type traceAlloc struct {
 //go:notinheap
 type traceAllocBlock struct {
 	next traceAllocBlockPtr
-	data [64<<10 - sys.PtrSize]byte
+	data [64<<10 - goarch.PtrSize]byte
 }
 
 // TODO: Since traceAllocBlock is now go:notinheap, this isn't necessary.
@@ -940,7 +941,7 @@ func (p *traceAllocBlockPtr) set(x *traceAllocBlock) { *p = traceAllocBlockPtr(u
 
 // alloc allocates n-byte block.
 func (a *traceAlloc) alloc(n uintptr) unsafe.Pointer {
-	n = alignUp(n, sys.PtrSize)
+	n = alignUp(n, goarch.PtrSize)
 	if a.head == 0 || a.off+n > uintptr(len(a.head.ptr().data)) {
 		if n > uintptr(len(a.head.ptr().data)) {
 			throw("trace: alloc too large")
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go
index 167d51c452a..addfa6faac8 100644
--- a/src/runtime/traceback.go
+++ b/src/runtime/traceback.go
@@ -6,6 +6,7 @@ package runtime
 
 import (
 	"internal/bytealg"
+	"internal/goarch"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -21,43 +22,6 @@ import (
 
 const usesLR = sys.MinFrameSize > 0
 
-// Traceback over the deferred function calls.
-// Report them like calls that have been invoked but not started executing yet.
-func tracebackdefers(gp *g, callback func(*stkframe, unsafe.Pointer) bool, v unsafe.Pointer) {
-	var frame stkframe
-	for d := gp._defer; d != nil; d = d.link {
-		fn := d.fn
-		if fn == nil {
-			// Defer of nil function. Args don't matter.
-			frame.pc = 0
-			frame.fn = funcInfo{}
-			frame.argp = 0
-			frame.arglen = 0
-			frame.argmap = nil
-		} else {
-			frame.pc = fn.fn
-			f := findfunc(frame.pc)
-			if !f.valid() {
-				print("runtime: unknown pc in defer ", hex(frame.pc), "\n")
-				throw("unknown pc")
-			}
-			frame.fn = f
-			frame.argp = uintptr(deferArgs(d))
-			var ok bool
-			frame.arglen, frame.argmap, ok = getArgInfoFast(f, true)
-			if !ok {
-				frame.arglen, frame.argmap = getArgInfo(&frame, f, true, fn)
-			}
-		}
-		frame.continpc = frame.pc
-		if !callback((*stkframe)(noescape(unsafe.Pointer(&frame))), v) {
-			return
-		}
-	}
-}
-
-const sizeofSkipFunction = 256
-
 // Generic traceback. Handles runtime stack prints (pcbuf == nil),
 // the runtime.Callers function (pcbuf != nil), as well as the garbage
 // collector (callback != nil).  A little clunky to merge these, but avoids
@@ -65,9 +29,7 @@ const sizeofSkipFunction = 256
 //
 // The skip argument is only valid with pcbuf != nil and counts the number
 // of logical frames to skip rather than physical frames (with inlining, a
-// PC in pcbuf can represent multiple calls). If a PC is partially skipped
-// and max > 1, pcbuf[1] will be runtime.skipPleaseUseCallersFrames+N where
-// N indicates the number of logical frames to skip in pcbuf[0].
+// PC in pcbuf can represent multiple calls).
 func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max int, callback func(*stkframe, unsafe.Pointer) bool, v unsafe.Pointer, flags uint) int {
 	if skip > 0 && callback != nil {
 		throw("gentraceback callback cannot be used with non-zero skip")
@@ -130,7 +92,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 			frame.lr = 0
 		} else {
 			frame.pc = uintptr(*(*uintptr)(unsafe.Pointer(frame.sp)))
-			frame.sp += sys.PtrSize
+			frame.sp += goarch.PtrSize
 		}
 	}
 
@@ -211,7 +173,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 			frame.fp = frame.sp + uintptr(funcspdelta(f, frame.pc, &cache))
 			if !usesLR {
 				// On x86, call instruction pushes return PC before entering new function.
-				frame.fp += sys.PtrSize
+				frame.fp += goarch.PtrSize
 			}
 		}
 		var flr funcInfo
@@ -219,18 +181,25 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 			// This function marks the top of the stack. Stop the traceback.
 			frame.lr = 0
 			flr = funcInfo{}
-		} else if flag&funcFlag_SPWRITE != 0 {
+		} else if flag&funcFlag_SPWRITE != 0 && (callback == nil || n > 0) {
 			// The function we are in does a write to SP that we don't know
 			// how to encode in the spdelta table. Examples include context
 			// switch routines like runtime.gogo but also any code that switches
 			// to the g0 stack to run host C code. Since we can't reliably unwind
 			// the SP (we might not even be on the stack we think we are),
 			// we stop the traceback here.
+			// This only applies for profiling signals (callback == nil).
+			//
+			// For a GC stack traversal (callback != nil), we should only see
+			// a function when it has voluntarily preempted itself on entry
+			// during the stack growth check. In that case, the function has
+			// not yet had a chance to do any writes to SP and is safe to unwind.
+			// isAsyncSafePoint does not allow assembly functions to be async preempted,
+			// and preemptPark double-checks that SPWRITE functions are not async preempted.
+			// So for GC stack traversal we leave things alone (this if body does not execute for n == 0)
+			// at the bottom frame of the stack. But farther up the stack we'd better not
+			// find any.
 			if callback != nil {
-				// Finding an SPWRITE should only happen for a profiling signal, which can
-				// arrive at any time. For a GC stack traversal (callback != nil),
-				// we shouldn't see this case, and we must be sure to walk the
-				// entire stack or the GC is invalid. So crash.
 				println("traceback: unexpected SPWRITE function", funcname(f))
 				throw("traceback")
 			}
@@ -245,7 +214,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 				}
 			} else {
 				if frame.lr == 0 {
-					lrPtr = frame.fp - sys.PtrSize
+					lrPtr = frame.fp - goarch.PtrSize
 					frame.lr = uintptr(*(*uintptr)(unsafe.Pointer(lrPtr)))
 				}
 			}
@@ -276,7 +245,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 		frame.varp = frame.fp
 		if !usesLR {
 			// On x86, call instruction pushes return PC before entering new function.
-			frame.varp -= sys.PtrSize
+			frame.varp -= goarch.PtrSize
 		}
 
 		// For architectures with frame pointers, if there's
@@ -297,7 +266,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in
 		// And it happens to end up mimicking the x86 layout.
 		// Other architectures may make different decisions.
 		if frame.varp > frame.sp && framepointer_enabled {
-			frame.varp -= sys.PtrSize
+			frame.varp -= goarch.PtrSize
 		}
 
 		// Derive size of arguments.
@@ -600,7 +569,7 @@ func printArgs(f funcInfo, argp unsafe.Pointer) {
 		// mask out irrelavant bits
 		if sz < 8 {
 			shift := 64 - sz*8
-			if sys.BigEndian {
+			if goarch.BigEndian {
 				x = x >> shift
 			} else {
 				x = x << shift >> shift
@@ -697,16 +666,16 @@ func getArgInfo(frame *stkframe, f funcInfo, needArgMap bool, ctxt *funcval) (ar
 				// Figure out whether the return values are valid.
 				// Reflect will update this value after it copies
 				// in the return values.
-				retValid = *(*bool)(unsafe.Pointer(arg0 + 4*sys.PtrSize))
+				retValid = *(*bool)(unsafe.Pointer(arg0 + 4*goarch.PtrSize))
 			}
 			if mv.fn != f.entry {
 				print("runtime: confused by ", funcname(f), "\n")
 				throw("reflect mismatch")
 			}
 			bv := mv.stack
-			arglen = uintptr(bv.n * sys.PtrSize)
+			arglen = uintptr(bv.n * goarch.PtrSize)
 			if !retValid {
-				arglen = uintptr(mv.argLen) &^ (sys.PtrSize - 1)
+				arglen = uintptr(mv.argLen) &^ (goarch.PtrSize - 1)
 			}
 			argmap = bv
 		}
@@ -1042,8 +1011,8 @@ func tracebackothers(me *g) {
 // for debugging purposes. If the address bad is included in the
 // hexdumped range, it will mark it as well.
 func tracebackHexdump(stk stack, frame *stkframe, bad uintptr) {
-	const expand = 32 * sys.PtrSize
-	const maxExpand = 256 * sys.PtrSize
+	const expand = 32 * goarch.PtrSize
+	const maxExpand = 256 * goarch.PtrSize
 	// Start around frame.sp.
 	lo, hi := frame.sp, frame.sp
 	// Expand to include frame.fp.
diff --git a/src/runtime/traceback_test.go b/src/runtime/traceback_test.go
index 2a0497e9a90..83b86a7e909 100644
--- a/src/runtime/traceback_test.go
+++ b/src/runtime/traceback_test.go
@@ -19,8 +19,8 @@ func TestTracebackArgs(t *testing.T) {
 	}{
 		// simple ints
 		{
-			func() int { return testTracebackArgs1(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) },
-			"testTracebackArgs1(0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, ...)",
+			func() int { return testTracebackArgs1(1, 2, 3, 4, 5) },
+			"testTracebackArgs1(0x1, 0x2, 0x3, 0x4, 0x5)",
 		},
 		// some aggregates
 		{
@@ -53,6 +53,58 @@ func TestTracebackArgs(t *testing.T) {
 			},
 			"testTracebackArgs5(0x0, {0x1, {}, {{}, {}}}, {}, {}, {}, {}, {}, ...)",
 		},
+
+		// edge cases for ...
+		// no ... for 10 args
+		{
+			func() int { return testTracebackArgs6a(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) },
+			"testTracebackArgs6a(0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa)",
+		},
+		// has ... for 11 args
+		{
+			func() int { return testTracebackArgs6b(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) },
+			"testTracebackArgs6b(0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, ...)",
+		},
+		// no ... for aggregates with 10 words
+		{
+			func() int { return testTracebackArgs7a([10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}) },
+			"testTracebackArgs7a({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa})",
+		},
+		// has ... for aggregates with 11 words
+		{
+			func() int { return testTracebackArgs7b([11]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}) },
+			"testTracebackArgs7b({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, ...})",
+		},
+		// no ... for aggregates, but with more args
+		{
+			func() int { return testTracebackArgs7c([10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, 11) },
+			"testTracebackArgs7c({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa}, ...)",
+		},
+		// has ... for aggregates and also for more args
+		{
+			func() int { return testTracebackArgs7d([11]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}, 12) },
+			"testTracebackArgs7d({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, ...}, ...)",
+		},
+		// nested aggregates, no ...
+		{
+			func() int { return testTracebackArgs8a(testArgsType8a{1, 2, 3, 4, 5, 6, 7, 8, [2]int{9, 10}}) },
+			"testTracebackArgs8a({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, {0x9, 0xa}})",
+		},
+		// nested aggregates, ... in inner but not outer
+		{
+			func() int { return testTracebackArgs8b(testArgsType8b{1, 2, 3, 4, 5, 6, 7, 8, [3]int{9, 10, 11}}) },
+			"testTracebackArgs8b({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, {0x9, 0xa, ...}})",
+		},
+		// nested aggregates, ... in outer but not inner
+		{
+			func() int { return testTracebackArgs8c(testArgsType8c{1, 2, 3, 4, 5, 6, 7, 8, [2]int{9, 10}, 11}) },
+			"testTracebackArgs8c({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, {0x9, 0xa}, ...})",
+		},
+		// nested aggregates, ... in both inner and outer
+		{
+			func() int { return testTracebackArgs8d(testArgsType8d{1, 2, 3, 4, 5, 6, 7, 8, [3]int{9, 10, 11}, 12}) },
+			"testTracebackArgs8d({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, {0x9, 0xa, ...}, ...})",
+		},
 	}
 	for _, test := range tests {
 		n := test.fn()
@@ -64,11 +116,11 @@ func TestTracebackArgs(t *testing.T) {
 }
 
 //go:noinline
-func testTracebackArgs1(a, b, c, d, e, f, g, h, i, j, k, l int) int {
+func testTracebackArgs1(a, b, c, d, e int) int {
 	n := runtime.Stack(testTracebackArgsBuf[:], false)
 	if a < 0 {
 		// use in-reg args to keep them alive
-		return a + b + c + d + e + f + g + h + i + j + k + l
+		return a + b + c + d + e
 	}
 	return n
 }
@@ -119,3 +171,122 @@ func testTracebackArgs5(a bool, x struct {
 	}
 	return n
 }
+
+//go:noinline
+func testTracebackArgs6a(a, b, c, d, e, f, g, h, i, j int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a < 0 {
+		// use in-reg args to keep them alive
+		return a + b + c + d + e + f + g + h + i + j
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs6b(a, b, c, d, e, f, g, h, i, j, k int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a < 0 {
+		// use in-reg args to keep them alive
+		return a + b + c + d + e + f + g + h + i + j + k
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs7a(a [10]int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a[0] < 0 {
+		// use in-reg args to keep them alive
+		return a[1] + a[2] + a[3] + a[4] + a[5] + a[6] + a[7] + a[8] + a[9]
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs7b(a [11]int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a[0] < 0 {
+		// use in-reg args to keep them alive
+		return a[1] + a[2] + a[3] + a[4] + a[5] + a[6] + a[7] + a[8] + a[9] + a[10]
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs7c(a [10]int, b int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a[0] < 0 {
+		// use in-reg args to keep them alive
+		return a[1] + a[2] + a[3] + a[4] + a[5] + a[6] + a[7] + a[8] + a[9] + b
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs7d(a [11]int, b int) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a[0] < 0 {
+		// use in-reg args to keep them alive
+		return a[1] + a[2] + a[3] + a[4] + a[5] + a[6] + a[7] + a[8] + a[9] + a[10] + b
+	}
+	return n
+}
+
+type testArgsType8a struct {
+	a, b, c, d, e, f, g, h int
+	i                      [2]int
+}
+type testArgsType8b struct {
+	a, b, c, d, e, f, g, h int
+	i                      [3]int
+}
+type testArgsType8c struct {
+	a, b, c, d, e, f, g, h int
+	i                      [2]int
+	j                      int
+}
+type testArgsType8d struct {
+	a, b, c, d, e, f, g, h int
+	i                      [3]int
+	j                      int
+}
+
+//go:noinline
+func testTracebackArgs8a(a testArgsType8a) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a.a < 0 {
+		// use in-reg args to keep them alive
+		return a.b + a.c + a.d + a.e + a.f + a.g + a.h + a.i[0] + a.i[1]
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs8b(a testArgsType8b) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a.a < 0 {
+		// use in-reg args to keep them alive
+		return a.b + a.c + a.d + a.e + a.f + a.g + a.h + a.i[0] + a.i[1] + a.i[2]
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs8c(a testArgsType8c) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a.a < 0 {
+		// use in-reg args to keep them alive
+		return a.b + a.c + a.d + a.e + a.f + a.g + a.h + a.i[0] + a.i[1] + a.j
+	}
+	return n
+}
+
+//go:noinline
+func testTracebackArgs8d(a testArgsType8d) int {
+	n := runtime.Stack(testTracebackArgsBuf[:], false)
+	if a.a < 0 {
+		// use in-reg args to keep them alive
+		return a.b + a.c + a.d + a.e + a.f + a.g + a.h + a.i[0] + a.i[1] + a.i[2] + a.j
+	}
+	return n
+}
diff --git a/src/runtime/type.go b/src/runtime/type.go
index c0911b1dcb1..ad01d5095e5 100644
--- a/src/runtime/type.go
+++ b/src/runtime/type.go
@@ -6,12 +6,15 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"internal/abi"
+	"unsafe"
+)
 
 // tflag is documented in reflect/type.go.
 //
 // tflag values must be kept in sync with copies in:
-//	cmd/compile/internal/gc/reflect.go
+//	cmd/compile/internal/reflectdata/reflect.go
 //	cmd/link/internal/ld/decodesym.go
 //	reflect/type.go
 //      internal/reflectlite/type.go
@@ -25,7 +28,7 @@ const (
 )
 
 // Needs to be in sync with ../cmd/link/internal/ld/decodesym.go:/^func.commonsize,
-// ../cmd/compile/internal/gc/reflect.go:/^func.dcommontype and
+// ../cmd/compile/internal/reflectdata/reflect.go:/^func.dcommontype and
 // ../reflect/type.go:/^type.rtype.
 // ../internal/reflectlite/type.go:/^type.rtype.
 type _type struct {
@@ -262,7 +265,7 @@ func (t *_type) textOff(off textOff) unsafe.Pointer {
 	if off == -1 {
 		// -1 is the sentinel value for unreachable code.
 		// See cmd/link/internal/ld/data.go:relocsym.
-		return unsafe.Pointer(funcPC(unreachableMethod))
+		return unsafe.Pointer(abi.FuncPCABIInternal(unreachableMethod))
 	}
 	base := uintptr(unsafe.Pointer(t))
 	var md *moduledata
@@ -383,7 +386,7 @@ type maptype struct {
 }
 
 // Note: flag values must match those used in the TMAP case
-// in ../cmd/compile/internal/gc/reflect.go:writeType.
+// in ../cmd/compile/internal/reflectdata/reflect.go:writeType.
 func (mt *maptype) indirectkey() bool { // store ptr to key instead of key itself
 	return mt.flags&1 != 0
 }
@@ -459,51 +462,52 @@ func (n name) isExported() bool {
 	return (*n.bytes)&(1<<0) != 0
 }
 
-func (n name) nameLen() int {
-	return int(uint16(*n.data(1))<<8 | uint16(*n.data(2)))
-}
-
-func (n name) tagLen() int {
-	if *n.data(0)&(1<<1) == 0 {
-		return 0
+func (n name) readvarint(off int) (int, int) {
+	v := 0
+	for i := 0; ; i++ {
+		x := *n.data(off + i)
+		v += int(x&0x7f) << (7 * i)
+		if x&0x80 == 0 {
+			return i + 1, v
+		}
 	}
-	off := 3 + n.nameLen()
-	return int(uint16(*n.data(off))<<8 | uint16(*n.data(off + 1)))
 }
 
 func (n name) name() (s string) {
 	if n.bytes == nil {
 		return ""
 	}
-	nl := n.nameLen()
-	if nl == 0 {
+	i, l := n.readvarint(1)
+	if l == 0 {
 		return ""
 	}
 	hdr := (*stringStruct)(unsafe.Pointer(&s))
-	hdr.str = unsafe.Pointer(n.data(3))
-	hdr.len = nl
-	return s
+	hdr.str = unsafe.Pointer(n.data(1 + i))
+	hdr.len = l
+	return
 }
 
 func (n name) tag() (s string) {
-	tl := n.tagLen()
-	if tl == 0 {
+	if *n.data(0)&(1<<1) == 0 {
 		return ""
 	}
-	nl := n.nameLen()
+	i, l := n.readvarint(1)
+	i2, l2 := n.readvarint(1 + i + l)
 	hdr := (*stringStruct)(unsafe.Pointer(&s))
-	hdr.str = unsafe.Pointer(n.data(3 + nl + 2))
-	hdr.len = tl
-	return s
+	hdr.str = unsafe.Pointer(n.data(1 + i + l + i2))
+	hdr.len = l2
+	return
 }
 
 func (n name) pkgPath() string {
 	if n.bytes == nil || *n.data(0)&(1<<2) == 0 {
 		return ""
 	}
-	off := 3 + n.nameLen()
-	if tl := n.tagLen(); tl > 0 {
-		off += 2 + tl
+	i, l := n.readvarint(1)
+	off := 1 + i + l
+	if *n.data(0)&(1<<1) != 0 {
+		i2, l2 := n.readvarint(off)
+		off += i2 + l2
 	}
 	var nameOff nameOff
 	copy((*[4]byte)(unsafe.Pointer(&nameOff))[:], (*[4]byte)(unsafe.Pointer(n.data(off)))[:])
@@ -515,10 +519,8 @@ func (n name) isBlank() bool {
 	if n.bytes == nil {
 		return false
 	}
-	if n.nameLen() != 1 {
-		return false
-	}
-	return *n.data(3) == '_'
+	_, l := n.readvarint(1)
+	return l == 1 && *n.data(2) == '_'
 }
 
 // typelinksinit scans the types from extra modules and builds the
diff --git a/src/runtime/wincallback.go b/src/runtime/wincallback.go
index 8411c98412d..73f1e567cec 100644
--- a/src/runtime/wincallback.go
+++ b/src/runtime/wincallback.go
@@ -22,7 +22,9 @@ func genasm386Amd64() {
 
 	buf.WriteString(`// Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
 
+//go:build 386 || amd64
 // +build 386 amd64
+
 // runtime·callbackasm is called by external code to
 // execute Go implemented callback function. It is not
 // called from the start, instead runtime·compilecallback
@@ -31,7 +33,7 @@ func genasm386Amd64() {
 // CALL instruction in runtime·callbackasm. This determines
 // which Go callback function is executed later on.
 
-TEXT runtime·callbackasm(SB),7,$0
+TEXT runtime·callbackasm(SB),7,$0
 `)
 	for i := 0; i < maxCallback; i++ {
 		buf.WriteString("\tCALL\truntime·callbackasm1(SB)\n")
@@ -59,7 +61,7 @@ func genasmArm() {
 // It then calls the Go implementation for that callback.
 #include "textflag.h"
 
-TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
 `)
 	for i := 0; i < maxCallback; i++ {
 		buf.WriteString(fmt.Sprintf("\tMOVW\t$%d, R12\n", i))
@@ -87,7 +89,7 @@ func genasmArm64() {
 // It then calls the Go implementation for that callback.
 #include "textflag.h"
 
-TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
 `)
 	for i := 0; i < maxCallback; i++ {
 		buf.WriteString(fmt.Sprintf("\tMOVD\t$%d, R12\n", i))
diff --git a/src/runtime/zcallback_windows.s b/src/runtime/zcallback_windows.s
index 37ffb38aca5..561527c90d1 100644
--- a/src/runtime/zcallback_windows.s
+++ b/src/runtime/zcallback_windows.s
@@ -1,6 +1,8 @@
 // Code generated by wincallback.go using 'go generate'. DO NOT EDIT.
 
+//go:build 386 || amd64
 // +build 386 amd64
+
 // runtime·callbackasm is called by external code to
 // execute Go implemented callback function. It is not
 // called from the start, instead runtime·compilecallback
@@ -9,7 +11,7 @@
 // CALL instruction in runtime·callbackasm. This determines
 // which Go callback function is executed later on.
 
-TEXT runtime·callbackasm(SB),7,$0
+TEXT runtime·callbackasm(SB),7,$0
 	CALL	runtime·callbackasm1(SB)
 	CALL	runtime·callbackasm1(SB)
 	CALL	runtime·callbackasm1(SB)
diff --git a/src/runtime/zcallback_windows_arm.s b/src/runtime/zcallback_windows_arm.s
index a73a813acb3..f943d84cbfe 100644
--- a/src/runtime/zcallback_windows_arm.s
+++ b/src/runtime/zcallback_windows_arm.s
@@ -9,7 +9,7 @@
 // It then calls the Go implementation for that callback.
 #include "textflag.h"
 
-TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
 	MOVW	$0, R12
 	B	runtime·callbackasm1(SB)
 	MOVW	$1, R12
diff --git a/src/runtime/zcallback_windows_arm64.s b/src/runtime/zcallback_windows_arm64.s
index 2a6bda0990c..69fb05788cd 100644
--- a/src/runtime/zcallback_windows_arm64.s
+++ b/src/runtime/zcallback_windows_arm64.s
@@ -9,7 +9,7 @@
 // It then calls the Go implementation for that callback.
 #include "textflag.h"
 
-TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
+TEXT runtime·callbackasm(SB),NOSPLIT|NOFRAME,$0
 	MOVD	$0, R12
 	B	runtime·callbackasm1(SB)
 	MOVD	$1, R12
diff --git a/src/strconv/atof.go b/src/strconv/atof.go
index 9010a66ca89..57556c70475 100644
--- a/src/strconv/atof.go
+++ b/src/strconv/atof.go
@@ -689,7 +689,7 @@ func atof64(s string) (f float64, n int, err error) {
 // as their respective special floating point values. It ignores case when matching.
 func ParseFloat(s string, bitSize int) (float64, error) {
 	f, n, err := parseFloatPrefix(s, bitSize)
-	if err == nil && n != len(s) {
+	if n != len(s) && (err == nil || err.(*NumError).Err != ErrSyntax) {
 		return 0, syntaxError(fnParseFloat, s)
 	}
 	return f, err
diff --git a/src/strconv/atof_test.go b/src/strconv/atof_test.go
index 3c058b9be5a..aa587a473cd 100644
--- a/src/strconv/atof_test.go
+++ b/src/strconv/atof_test.go
@@ -342,6 +342,9 @@ var atoftests = []atofTest{
 	{"0x12.345p-_12", "0", ErrSyntax},
 	{"0x12.345p+1__2", "0", ErrSyntax},
 	{"0x12.345p+12_", "0", ErrSyntax},
+
+	{"1e100x", "0", ErrSyntax},
+	{"1e1000x", "0", ErrSyntax},
 }
 
 var atof32tests = []atofTest{
diff --git a/src/strconv/atoi.go b/src/strconv/atoi.go
index c9ba0383b3f..631b487d976 100644
--- a/src/strconv/atoi.go
+++ b/src/strconv/atoi.go
@@ -57,6 +57,8 @@ const IntSize = intSize
 const maxUint64 = 1<<64 - 1
 
 // ParseUint is like ParseInt but for unsigned numbers.
+//
+// A sign prefix is not permitted.
 func ParseUint(s string, base int, bitSize int) (uint64, error) {
 	const fnParseUint = "ParseUint"
 
@@ -159,10 +161,13 @@ func ParseUint(s string, base int, bitSize int) (uint64, error) {
 // ParseInt interprets a string s in the given base (0, 2 to 36) and
 // bit size (0 to 64) and returns the corresponding value i.
 //
+// The string may begin with a leading sign: "+" or "-".
+//
 // If the base argument is 0, the true base is implied by the string's
-// prefix: 2 for "0b", 8 for "0" or "0o", 16 for "0x", and 10 otherwise.
-// Also, for argument base 0 only, underscore characters are permitted
-// as defined by the Go syntax for integer literals.
+// prefix following the sign (if present): 2 for "0b", 8 for "0" or "0o",
+// 16 for "0x", and 10 otherwise. Also, for argument base 0 only,
+// underscore characters are permitted as defined by the Go syntax for
+// integer literals.
 //
 // The bitSize argument specifies the integer type
 // that the result must fit into. Bit sizes 0, 8, 16, 32, and 64
diff --git a/src/strconv/atoi_test.go b/src/strconv/atoi_test.go
index 178fb01ea7e..867fa66a14c 100644
--- a/src/strconv/atoi_test.go
+++ b/src/strconv/atoi_test.go
@@ -33,6 +33,9 @@ var parseUint64Tests = []parseUint64Test{
 	{"_12345", 0, ErrSyntax},
 	{"1__2345", 0, ErrSyntax},
 	{"12345_", 0, ErrSyntax},
+	{"-0", 0, ErrSyntax},
+	{"-1", 0, ErrSyntax},
+	{"+1", 0, ErrSyntax},
 }
 
 type parseUint64BaseTest struct {
@@ -140,8 +143,10 @@ var parseInt64Tests = []parseInt64Test{
 	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"-0", 0, nil},
+	{"+0", 0, nil},
 	{"1", 1, nil},
 	{"-1", -1, nil},
+	{"+1", 1, nil},
 	{"12345", 12345, nil},
 	{"-12345", -12345, nil},
 	{"012345", 12345, nil},
@@ -236,6 +241,11 @@ var parseInt64BaseTests = []parseInt64BaseTest{
 	{"0__12345", 0, 0, ErrSyntax},
 	{"01234__5", 0, 0, ErrSyntax},
 	{"012345_", 0, 0, ErrSyntax},
+
+	{"+0xf", 0, 0xf, nil},
+	{"-0xf", 0, -0xf, nil},
+	{"0x+f", 0, 0, ErrSyntax},
+	{"0x-f", 0, 0, ErrSyntax},
 }
 
 type parseUint32Test struct {
diff --git a/src/sync/atomic/asm.s b/src/sync/atomic/asm.s
index f86726f3a1a..7b8c9b9430e 100644
--- a/src/sync/atomic/asm.s
+++ b/src/sync/atomic/asm.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !race
 // +build !race
 
 #include "textflag.h"
diff --git a/src/sync/atomic/race.s b/src/sync/atomic/race.s
index fd6ca22700c..0866487cc71 100644
--- a/src/sync/atomic/race.s
+++ b/src/sync/atomic/race.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build race
 // +build race
 
 // This file is here only to allow external functions.
diff --git a/src/sync/atomic/value.go b/src/sync/atomic/value.go
index 61f81d8fd37..3500cd22f4e 100644
--- a/src/sync/atomic/value.go
+++ b/src/sync/atomic/value.go
@@ -126,7 +126,7 @@ func (v *Value) Swap(new interface{}) (old interface{}) {
 	}
 }
 
-// CompareAndSwapPointer executes the compare-and-swap operation for the Value.
+// CompareAndSwap executes the compare-and-swap operation for the Value.
 //
 // All calls to CompareAndSwap for a given Value must use values of the same
 // concrete type. CompareAndSwap of an inconsistent type panics, as does
diff --git a/src/syscall/asm_openbsd_arm.s b/src/syscall/asm_openbsd_arm.s
index 26fd791fdad..520da91bf32 100644
--- a/src/syscall/asm_openbsd_arm.s
+++ b/src/syscall/asm_openbsd_arm.s
@@ -3,137 +3,30 @@
 // license that can be found in the LICENSE file.
 
 #include "textflag.h"
-#include "funcdata.h"
 
 //
 // System call support for ARM, OpenBSD
 //
 
-// func Syscall(trap int32, a1, a2, a3 int32) (r1, r2, err int32);
-// func Syscall6(trap int32, a1, a2, a3, a4, a5, a6 int32) (r1, r2, err int32);
-// func Syscall9(trap int32, a1, a2, a3, a4, a5, a6, a7, a8, a9 int64) (r1, r2, err int32)
-// func RawSyscall(trap int32, a1, a2, a3 int32) (r1, r2, err int32);
-// func RawSyscall6(trap int32, a1, a2, a3, a4, a5, a6 int32) (r1, r2, err int32);
-
-// See comment in runtime/sys_openbsd_arm.s re this construction.
-#define NOOP	MOVW    R0, R0
-#define	INVOKE_SYSCALL	\
-	SWI	$0;	\
-	NOOP;		\
-	NOOP
+// Provide these function names via assembly so they are provided as ABI0,
+// rather than ABIInternal.
 
+// func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 TEXT	·Syscall(SB),NOSPLIT,$0-28
-	BL runtime·entersyscall(SB)
-	MOVW trap+0(FP), R12		// syscall number
-	MOVW a1+4(FP), R0		// arg 1
-	MOVW a2+8(FP), R1		// arg 2
-	MOVW a3+12(FP), R2		// arg 3
-	INVOKE_SYSCALL
-	MOVW $0, R2
-	BCS error
-	MOVW R0, r1+16(FP)		// ret 1
-	MOVW R1, r2+20(FP)		// ret 2
-	MOVW R2, err+24(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
-error:
-	MOVW $-1, R3
-	MOVW R3, r1+16(FP)		// ret 1
-	MOVW R2, r2+20(FP)		// ret 2
-	MOVW R0, err+24(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
+	JMP	·syscallInternal(SB)
 
+// func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
 TEXT	·Syscall6(SB),NOSPLIT,$0-40
-	BL runtime·entersyscall(SB)
-	MOVW trap+0(FP), R12		// syscall number
-	MOVW a1+4(FP), R0		// arg 1
-	MOVW a2+8(FP), R1		// arg 2
-	MOVW a3+12(FP), R2		// arg 3
-	MOVW a4+16(FP), R3		// arg 4
-	MOVW R13, R4
-	MOVW $a5+20(FP), R13		// arg 5 to arg 6 are passed on stack
-	INVOKE_SYSCALL
-	MOVW R4, R13
-	MOVW $0, R2
-	BCS error6
-	MOVW R0, r1+28(FP)		// ret 1
-	MOVW R1, r2+32(FP)		// ret 2
-	MOVW R2, err+36(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
-error6:
-	MOVW $-1, R3
-	MOVW R3, r1+28(FP)		// ret 1
-	MOVW R2, r2+32(FP)		// ret 2
-	MOVW R0, err+36(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
-
-TEXT	·Syscall9(SB),NOSPLIT,$0-52
-	BL runtime·entersyscall(SB)
-	MOVW num+0(FP), R12		// syscall number
-	MOVW a1+4(FP), R0		// arg 1
-	MOVW a2+8(FP), R1		// arg 2
-	MOVW a3+12(FP), R2		// arg 3
-	MOVW a4+16(FP), R3		// arg 4
-	MOVW R13, R4
-	MOVW $a5+20(FP), R13		// arg 5 to arg 9 are passed on stack
-	INVOKE_SYSCALL
-	MOVW R4, R13
-	MOVW $0, R2
-	BCS error9
-	MOVW R0, r1+40(FP)		// ret 1
-	MOVW R1, r2+44(FP)		// ret 2
-	MOVW R2, err+48(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
-error9:
-	MOVW $-1, R3
-	MOVW R3, r1+40(FP)		// ret 1
-	MOVW R2, r2+44(FP)		// ret 2
-	MOVW R0, err+48(FP)		// err
-	BL runtime·exitsyscall(SB)
-	RET
+	JMP	·syscall6Internal(SB)
 
+// func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 TEXT	·RawSyscall(SB),NOSPLIT,$0-28
-	MOVW trap+0(FP), R12		// syscall number
-	MOVW a1+4(FP), R0		// arg 1
-	MOVW a2+8(FP), R1		// arg 2
-	MOVW a3+12(FP), R2		// arg 3
-	INVOKE_SYSCALL
-	MOVW $0, R2
-	BCS errorr
-	MOVW R0, r1+16(FP)		// ret 1
-	MOVW R1, r2+20(FP)		// ret 2
-	MOVW R2, err+24(FP)		// err
-	RET
-errorr:
-	MOVW $-1, R3
-	MOVW R3, r1+16(FP)		// ret 1
-	MOVW R2, r2+20(FP)		// ret 2
-	MOVW R0, err+24(FP)		// err
-	RET
+	JMP	·rawSyscallInternal(SB)
 
+// func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
 TEXT	·RawSyscall6(SB),NOSPLIT,$0-40
-	MOVW trap+0(FP), R12		// syscall number
-	MOVW a1+4(FP), R0		// arg 1
-	MOVW a2+8(FP), R1		// arg 2
-	MOVW a3+12(FP), R2		// arg 3
-	MOVW a4+16(FP), R3		// arg 4
-	MOVW R13, R4
-	MOVW $a5+20(FP), R13		// arg 5 to arg 6 are passed on stack
-	INVOKE_SYSCALL
-	MOVW R4, R13
-	MOVW $0, R2
-	BCS errorr6
-	MOVW R0, r1+28(FP)		// ret 1
-	MOVW R1, r2+32(FP)		// ret 2
-	MOVW R2, err+36(FP)		// err
-	RET
-errorr6:
-	MOVW $-1, R3
-	MOVW R3, r1+28(FP)		// ret 1
-	MOVW R2, r2+32(FP)		// ret 2
-	MOVW R0, err+36(FP)		// err
-	RET
+	JMP	·rawSyscall6Internal(SB)
+
+// func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err Errno)
+TEXT	·Syscall9(SB),NOSPLIT,$0-52
+	JMP	·syscall9Internal(SB)
diff --git a/src/syscall/exec_bsd.go b/src/syscall/exec_bsd.go
index 41d1f693b2b..709066e809b 100644
--- a/src/syscall/exec_bsd.go
+++ b/src/syscall/exec_bsd.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || netbsd || (openbsd && !386 && !amd64 && !arm64)
-// +build dragonfly freebsd netbsd openbsd,!386,!amd64,!arm64
+//go:build dragonfly || freebsd || netbsd || (openbsd && mips64)
+// +build dragonfly freebsd netbsd openbsd,mips64
 
 package syscall
 
diff --git a/src/syscall/exec_libc2.go b/src/syscall/exec_libc2.go
index 8e957b3d4a0..b999754c2e8 100644
--- a/src/syscall/exec_libc2.go
+++ b/src/syscall/exec_libc2.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build darwin || (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build darwin openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build darwin || (openbsd && !mips64)
+// +build darwin openbsd,!mips64
 
 package syscall
 
diff --git a/src/syscall/exec_linux_test.go b/src/syscall/exec_linux_test.go
index 7d89eaae63a..85b59ad00d9 100644
--- a/src/syscall/exec_linux_test.go
+++ b/src/syscall/exec_linux_test.go
@@ -318,6 +318,7 @@ func TestGroupCleanupUserNamespace(t *testing.T) {
 		"uid=0(root) gid=0(root) groups=0(root),65534",
 		"uid=0(root) gid=0(root) groups=0(root),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody)", // Alpine; see https://golang.org/issue/19938
 		"uid=0(root) gid=0(root) groups=0(root) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023",                                                                               // CentOS with SELinux context, see https://golang.org/issue/34547
+		"uid=0(root) gid=0(root) groups=0(root),65534(nobody) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023",                                                                 // Fedora with SElinux context, see https://golang.org/issue/46752
 	}
 	for _, e := range expected {
 		if strOut == e {
diff --git a/src/syscall/exec_unix.go b/src/syscall/exec_unix.go
index 206a1e17d67..54b18dccd73 100644
--- a/src/syscall/exec_unix.go
+++ b/src/syscall/exec_unix.go
@@ -301,7 +301,7 @@ func Exec(argv0 string, argv []string, envv []string) (err error) {
 	} else if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
 		// Similarly on Darwin.
 		err1 = execveDarwin(argv0p, &argvp[0], &envvp[0])
-	} else if runtime.GOOS == "openbsd" && (runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "arm64") {
+	} else if runtime.GOOS == "openbsd" && (runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
 		// Similarly on OpenBSD.
 		err1 = execveOpenBSD(argv0p, &argvp[0], &envvp[0])
 	} else {
diff --git a/src/syscall/exec_windows.go b/src/syscall/exec_windows.go
index 253e9e8c1f9..18d15028c3d 100644
--- a/src/syscall/exec_windows.go
+++ b/src/syscall/exec_windows.go
@@ -313,6 +313,17 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 		}
 	}
 
+	var maj, min, build uint32
+	rtlGetNtVersionNumbers(&maj, &min, &build)
+	isWin7 := maj < 6 || (maj == 6 && min <= 1)
+	// NT kernel handles are divisible by 4, with the bottom 3 bits left as
+	// a tag. The fully set tag correlates with the types of handles we're
+	// concerned about here.  Except, the kernel will interpret some
+	// special handle values, like -1, -2, and so forth, so kernelbase.dll
+	// checks to see that those bottom three bits are checked, but that top
+	// bit is not checked.
+	isLegacyWin7ConsoleHandle := func(handle Handle) bool { return isWin7 && handle&0x10000003 == 3 }
+
 	p, _ := GetCurrentProcess()
 	parentProcess := p
 	if sys.ParentProcess != 0 {
@@ -321,7 +332,15 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	fd := make([]Handle, len(attr.Files))
 	for i := range attr.Files {
 		if attr.Files[i] > 0 {
-			err := DuplicateHandle(p, Handle(attr.Files[i]), parentProcess, &fd[i], 0, true, DUPLICATE_SAME_ACCESS)
+			destinationProcessHandle := parentProcess
+
+			// On Windows 7, console handles aren't real handles, and can only be duplicated
+			// into the current process, not a parent one, which amounts to the same thing.
+			if parentProcess != p && isLegacyWin7ConsoleHandle(Handle(attr.Files[i])) {
+				destinationProcessHandle = p
+			}
+
+			err := DuplicateHandle(p, Handle(attr.Files[i]), destinationProcessHandle, &fd[i], 0, true, DUPLICATE_SAME_ACCESS)
 			if err != nil {
 				return 0, 0, err
 			}
@@ -351,19 +370,40 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	si.StdErr = fd[2]
 
 	fd = append(fd, sys.AdditionalInheritedHandles...)
+
+	// On Windows 7, console handles aren't real handles, so don't pass them
+	// through to PROC_THREAD_ATTRIBUTE_HANDLE_LIST.
+	for i := range fd {
+		if isLegacyWin7ConsoleHandle(fd[i]) {
+			fd[i] = 0
+		}
+	}
+
+	// The presence of a NULL handle in the list is enough to cause PROC_THREAD_ATTRIBUTE_HANDLE_LIST
+	// to treat the entire list as empty, so remove NULL handles.
+	j := 0
+	for i := range fd {
+		if fd[i] != 0 {
+			fd[j] = fd[i]
+			j++
+		}
+	}
+	fd = fd[:j]
+
 	// Do not accidentally inherit more than these handles.
-	err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_HANDLE_LIST, unsafe.Pointer(&fd[0]), uintptr(len(fd))*unsafe.Sizeof(fd[0]), nil, nil)
-	if err != nil {
-		return 0, 0, err
+	if len(fd) > 0 {
+		err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_HANDLE_LIST, unsafe.Pointer(&fd[0]), uintptr(len(fd))*unsafe.Sizeof(fd[0]), nil, nil)
+		if err != nil {
+			return 0, 0, err
+		}
 	}
 
 	pi := new(ProcessInformation)
-
 	flags := sys.CreationFlags | CREATE_UNICODE_ENVIRONMENT | _EXTENDED_STARTUPINFO_PRESENT
 	if sys.Token != 0 {
-		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	} else {
-		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	}
 	if err != nil {
 		return 0, 0, err
diff --git a/src/syscall/js/export_test.go b/src/syscall/js/export_test.go
index 1b5ed3ce849..4bd9c5d595e 100644
--- a/src/syscall/js/export_test.go
+++ b/src/syscall/js/export_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build js && wasm
 // +build js,wasm
 
 package js
diff --git a/src/syscall/js/func.go b/src/syscall/js/func.go
index da4cf68774d..ab23e5fbfc0 100644
--- a/src/syscall/js/func.go
+++ b/src/syscall/js/func.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build js && wasm
 // +build js,wasm
 
 package js
diff --git a/src/syscall/js/js.go b/src/syscall/js/js.go
index a48bbd4dd79..d805d691664 100644
--- a/src/syscall/js/js.go
+++ b/src/syscall/js/js.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build js && wasm
 // +build js,wasm
 
 // Package js gives access to the WebAssembly host environment when using the js/wasm architecture.
diff --git a/src/syscall/js/js_test.go b/src/syscall/js/js_test.go
index 5fc9107d402..8088a897f60 100644
--- a/src/syscall/js/js_test.go
+++ b/src/syscall/js/js_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build js && wasm
 // +build js,wasm
 
 // To run these tests:
diff --git a/src/syscall/mkall.sh b/src/syscall/mkall.sh
index 7739147310c..dffb52864ba 100755
--- a/src/syscall/mkall.sh
+++ b/src/syscall/mkall.sh
@@ -303,15 +303,16 @@ openbsd_amd64)
 	mkasm="go run mkasm.go"
 	;;
 openbsd_arm)
-	GOOSARCH_in="syscall_openbsd1.go syscall_openbsd_$GOARCH.go"
+	GOOSARCH_in="syscall_openbsd_libc.go syscall_openbsd_$GOARCH.go"
 	mkerrors="$mkerrors"
-	mksyscall="./mksyscall.pl -l32 -openbsd -arm"
+	mksyscall="./mksyscall.pl -l32 -openbsd -arm -libc"
 	mksysctl="./mksysctl_openbsd.pl"
 	zsysctl="zsysctl_openbsd.go"
 	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
 	# Let the type of C char be signed to make the bare syscall
 	# API consistent between platforms.
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs -- -fsigned-char"
+	mkasm="go run mkasm.go"
 	;;
 openbsd_arm64)
 	GOOSARCH_in="syscall_openbsd_libc.go syscall_openbsd_$GOARCH.go"
diff --git a/src/syscall/mksyscall.pl b/src/syscall/mksyscall.pl
index 5ca3b465d80..758948bc53f 100755
--- a/src/syscall/mksyscall.pl
+++ b/src/syscall/mksyscall.pl
@@ -191,6 +191,10 @@ while(<>) {
 			if (!$libc) {
 				push @args, "0";
 			}
+			if($libc && $arm && @args % 2) {
+				# arm abi specifies 64 bit argument must be 64 bit aligned.
+				push @args, "0"
+			}
 			if($_32bit eq "big-endian") {
 				push @args, "uintptr($name>>32)", "uintptr($name)";
 			} elsif($_32bit eq "little-endian") {
diff --git a/src/syscall/syscall_linux_test.go b/src/syscall/syscall_linux_test.go
index adeb7c9ebbf..442dc9f10eb 100644
--- a/src/syscall/syscall_linux_test.go
+++ b/src/syscall/syscall_linux_test.go
@@ -14,6 +14,7 @@ import (
 	"os/signal"
 	"path/filepath"
 	"runtime"
+	"sort"
 	"strconv"
 	"strings"
 	"syscall"
@@ -583,11 +584,23 @@ func compareStatus(filter, expect string) error {
 				// "Pid:\t".
 			}
 			if strings.HasPrefix(line, filter) {
-				if line != expected {
-					return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc)
+				if line == expected {
+					foundAThread = true
+					break
 				}
-				foundAThread = true
-				break
+				if filter == "Groups:" && strings.HasPrefix(line, "Groups:\t") {
+					// https://github.com/golang/go/issues/46145
+					// Containers don't reliably output this line in sorted order so manually sort and compare that.
+					a := strings.Split(line[8:], " ")
+					sort.Strings(a)
+					got := strings.Join(a, " ")
+					if got == expected[8:] {
+						foundAThread = true
+						break
+					}
+
+				}
+				return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc)
 			}
 		}
 	}
diff --git a/src/syscall/syscall_openbsd1.go b/src/syscall/syscall_openbsd1.go
index c446768aab6..15870ce1ee1 100644
--- a/src/syscall/syscall_openbsd1.go
+++ b/src/syscall/syscall_openbsd1.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build openbsd && !386 && !amd64 && !arm64
-// +build openbsd,!386,!amd64,!arm64
+//go:build openbsd && mips64
+// +build openbsd,mips64
 
 package syscall
 
diff --git a/src/syscall/syscall_openbsd_libc.go b/src/syscall/syscall_openbsd_libc.go
index 750be6f7078..e67ee4e571c 100644
--- a/src/syscall/syscall_openbsd_libc.go
+++ b/src/syscall/syscall_openbsd_libc.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (openbsd && 386) || (openbsd && amd64) || (openbsd && arm64)
-// +build openbsd,386 openbsd,amd64 openbsd,arm64
+//go:build openbsd && !mips64
+// +build openbsd,!mips64
 
 package syscall
 
diff --git a/src/syscall/syscall_windows.go b/src/syscall/syscall_windows.go
index f9f78bd2b30..660179ae9e8 100644
--- a/src/syscall/syscall_windows.go
+++ b/src/syscall/syscall_windows.go
@@ -174,6 +174,9 @@ func compileCallback(fn interface{}, cleanstack bool) uintptr
 // NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
 // This is useful when interoperating with Windows code requiring callbacks.
 // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
+// Only a limited number of callbacks may be created in a single Go process, and any memory allocated
+// for these callbacks is never released.
+// Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
 func NewCallback(fn interface{}) uintptr {
 	return compileCallback(fn, true)
 }
@@ -181,6 +184,9 @@ func NewCallback(fn interface{}) uintptr {
 // NewCallbackCDecl converts a Go function to a function pointer conforming to the cdecl calling convention.
 // This is useful when interoperating with Windows code requiring callbacks.
 // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
+// Only a limited number of callbacks may be created in a single Go process, and any memory allocated
+// for these callbacks is never released.
+// Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
 func NewCallbackCDecl(fn interface{}) uintptr {
 	return compileCallback(fn, false)
 }
@@ -192,6 +198,7 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	FreeLibrary(handle Handle) (err error)
 //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
 //sys	GetVersion() (ver uint32, err error)
+//sys	rtlGetNtVersionNumbers(majorVersion *uint32, minorVersion *uint32, buildNumber *uint32) = ntdll.RtlGetNtVersionNumbers
 //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
 //sys	ExitProcess(exitcode uint32)
 //sys	CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval==InvalidHandle] = CreateFileW
@@ -472,7 +479,6 @@ var (
 
 func getStdHandle(h int) (fd Handle) {
 	r, _ := GetStdHandle(h)
-	CloseOnExec(r)
 	return r
 }
 
diff --git a/src/syscall/syscall_windows_test.go b/src/syscall/syscall_windows_test.go
index b8ec6bee39b..194c87805cd 100644
--- a/src/syscall/syscall_windows_test.go
+++ b/src/syscall/syscall_windows_test.go
@@ -5,8 +5,12 @@
 package syscall_test
 
 import (
+	"fmt"
+	"internal/testenv"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 	"syscall"
 	"testing"
 )
@@ -71,3 +75,75 @@ func TestTOKEN_ALL_ACCESS(t *testing.T) {
 		t.Errorf("TOKEN_ALL_ACCESS = %x, want 0xF01FF", syscall.TOKEN_ALL_ACCESS)
 	}
 }
+
+func TestStdioAreInheritable(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveExecPath(t, "gcc")
+
+	tmpdir := t.TempDir()
+
+	// build go dll
+	const dlltext = `
+package main
+
+import "C"
+import (
+	"fmt"
+)
+
+//export HelloWorld
+func HelloWorld() {
+	fmt.Println("Hello World")
+}
+
+func main() {}
+`
+	dllsrc := filepath.Join(tmpdir, "helloworld.go")
+	err := os.WriteFile(dllsrc, []byte(dlltext), 0644)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dll := filepath.Join(tmpdir, "helloworld.dll")
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", dll, "-buildmode", "c-shared", dllsrc)
+	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build go library: %s\n%s", err, out)
+	}
+
+	// build c exe
+	const exetext = `
+#include 
+#include 
+int main(int argc, char *argv[])
+{
+	system("hostname");
+	((void(*)(void))GetProcAddress(LoadLibraryA(%q), "HelloWorld"))();
+	system("hostname");
+	return 0;
+}
+`
+	exe := filepath.Join(tmpdir, "helloworld.exe")
+	cmd = exec.Command("gcc", "-o", exe, "-xc", "-")
+	cmd.Stdin = strings.NewReader(fmt.Sprintf(exetext, dll))
+	out, err = testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build c executable: %s\n%s", err, out)
+	}
+	out, err = exec.Command(exe).CombinedOutput()
+	if err != nil {
+		t.Fatalf("c program execution failed: %v: %v", err, string(out))
+	}
+
+	hostname, err := os.Hostname()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	have := strings.ReplaceAll(string(out), "\n", "")
+	have = strings.ReplaceAll(have, "\r", "")
+	want := fmt.Sprintf("%sHello World%s", hostname, hostname)
+	if have != want {
+		t.Fatalf("c program output is wrong: got %q, want %q", have, want)
+	}
+}
diff --git a/src/syscall/zsyscall_openbsd_arm.go b/src/syscall/zsyscall_openbsd_arm.go
index 31425b35588..04a2fadccdd 100644
--- a/src/syscall/zsyscall_openbsd_arm.go
+++ b/src/syscall/zsyscall_openbsd_arm.go
@@ -1,4 +1,4 @@
-// mksyscall.pl -l32 -openbsd -arm -tags openbsd,arm syscall_bsd.go syscall_openbsd.go syscall_openbsd_arm.go
+// mksyscall.pl -l32 -openbsd -arm -libc -tags openbsd,arm syscall_bsd.go syscall_openbsd.go syscall_openbsd_libc.go syscall_openbsd_arm.go
 // Code generated by the command above; DO NOT EDIT.
 
 //go:build openbsd && arm
@@ -7,11 +7,12 @@
 package syscall
 
 import "unsafe"
+import "internal/abi"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
-	r0, _, e1 := RawSyscall(SYS_GETGROUPS, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -19,20 +20,28 @@ func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
 	return
 }
 
+func libc_getgroups_trampoline()
+
+//go:cgo_import_dynamic libc_getgroups getgroups "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setgroups(ngid int, gid *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setgroups_trampoline), uintptr(ngid), uintptr(unsafe.Pointer(gid)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setgroups_trampoline()
+
+//go:cgo_import_dynamic libc_setgroups setgroups "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) {
-	r0, _, e1 := Syscall6(SYS_WAIT4, uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_wait4_trampoline), uintptr(pid), uintptr(unsafe.Pointer(wstatus)), uintptr(options), uintptr(unsafe.Pointer(rusage)), 0, 0)
 	wpid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -40,10 +49,14 @@ func wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err
 	return
 }
 
+func libc_wait4_trampoline()
+
+//go:cgo_import_dynamic libc_wait4 wait4 "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
-	r0, _, e1 := Syscall(SYS_ACCEPT, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_accept_trampoline), uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -51,30 +64,42 @@ func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) {
 	return
 }
 
+func libc_accept_trampoline()
+
+//go:cgo_import_dynamic libc_accept accept "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := Syscall(SYS_BIND, uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_bind_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_bind_trampoline()
+
+//go:cgo_import_dynamic libc_bind bind "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) {
-	_, _, e1 := Syscall(SYS_CONNECT, uintptr(s), uintptr(addr), uintptr(addrlen))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_connect_trampoline), uintptr(s), uintptr(addr), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_connect_trampoline()
+
+//go:cgo_import_dynamic libc_connect connect "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socket(domain int, typ int, proto int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_SOCKET, uintptr(domain), uintptr(typ), uintptr(proto))
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_socket_trampoline), uintptr(domain), uintptr(typ), uintptr(proto))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -82,66 +107,94 @@ func socket(domain int, typ int, proto int) (fd int, err error) {
 	return
 }
 
+func libc_socket_trampoline()
+
+//go:cgo_import_dynamic libc_socket socket "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
-	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_getsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_getsockopt_trampoline()
+
+//go:cgo_import_dynamic libc_getsockopt getsockopt "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) {
-	_, _, e1 := Syscall6(SYS_SETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_setsockopt_trampoline), uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(vallen), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setsockopt_trampoline()
+
+//go:cgo_import_dynamic libc_setsockopt setsockopt "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := RawSyscall(SYS_GETPEERNAME, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getpeername_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_getpeername_trampoline()
+
+//go:cgo_import_dynamic libc_getpeername getpeername "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) {
-	_, _, e1 := RawSyscall(SYS_GETSOCKNAME, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getsockname_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_getsockname_trampoline()
+
+//go:cgo_import_dynamic libc_getsockname getsockname "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Shutdown(s int, how int) (err error) {
-	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(s), uintptr(how), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_shutdown_trampoline), uintptr(s), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_shutdown_trampoline()
+
+//go:cgo_import_dynamic libc_shutdown shutdown "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func socketpair(domain int, typ int, proto int, fd *[2]int32) (err error) {
-	_, _, e1 := RawSyscall6(SYS_SOCKETPAIR, uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
+	_, _, e1 := rawSyscall6(abi.FuncPCABI0(libc_socketpair_trampoline), uintptr(domain), uintptr(typ), uintptr(proto), uintptr(unsafe.Pointer(fd)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_socketpair_trampoline()
+
+//go:cgo_import_dynamic libc_socketpair socketpair "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) {
@@ -151,7 +204,7 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall6(SYS_RECVFROM, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_recvfrom_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -159,6 +212,10 @@ func recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Sockl
 	return
 }
 
+func libc_recvfrom_trampoline()
+
+//go:cgo_import_dynamic libc_recvfrom recvfrom "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error) {
@@ -168,17 +225,21 @@ func sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	_, _, e1 := Syscall6(SYS_SENDTO, uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_sendto_trampoline), uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_sendto_trampoline()
+
+//go:cgo_import_dynamic libc_sendto sendto "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := Syscall(SYS_RECVMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_recvmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -186,10 +247,14 @@ func recvmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
+func libc_recvmsg_trampoline()
+
+//go:cgo_import_dynamic libc_recvmsg recvmsg "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
-	r0, _, e1 := Syscall(SYS_SENDMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_sendmsg_trampoline), uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -197,10 +262,14 @@ func sendmsg(s int, msg *Msghdr, flags int) (n int, err error) {
 	return
 }
 
+func libc_sendmsg_trampoline()
+
+//go:cgo_import_dynamic libc_sendmsg sendmsg "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error) {
-	r0, _, e1 := Syscall6(SYS_KEVENT, uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_kevent_trampoline), uintptr(kq), uintptr(change), uintptr(nchange), uintptr(event), uintptr(nevent), uintptr(unsafe.Pointer(timeout)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -208,21 +277,9 @@ func kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, ne
 	return
 }
 
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func libc_kevent_trampoline()
 
-func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) {
-	var _p0 unsafe.Pointer
-	if len(mib) > 0 {
-		_p0 = unsafe.Pointer(&mib[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := Syscall6(SYS___SYSCTL, uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
+//go:cgo_import_dynamic libc_kevent kevent "libc.so"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
@@ -232,27 +289,35 @@ func utimes(path string, timeval *[2]Timeval) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_UTIMES, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_utimes_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_utimes_trampoline()
+
+//go:cgo_import_dynamic libc_utimes utimes "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func futimes(fd int, timeval *[2]Timeval) (err error) {
-	_, _, e1 := Syscall(SYS_FUTIMES, uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_futimes_trampoline), uintptr(fd), uintptr(unsafe.Pointer(timeval)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_futimes_trampoline()
+
+//go:cgo_import_dynamic libc_futimes futimes "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func fcntl(fd int, cmd int, arg int) (val int, err error) {
-	r0, _, e1 := Syscall(SYS_FCNTL, uintptr(fd), uintptr(cmd), uintptr(arg))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -260,20 +325,28 @@ func fcntl(fd int, cmd int, arg int) (val int, err error) {
 	return
 }
 
+func libc_fcntl_trampoline()
+
+//go:cgo_import_dynamic libc_fcntl fcntl "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_pipe2_trampoline), uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_pipe2_trampoline()
+
+//go:cgo_import_dynamic libc_pipe2 pipe2 "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error) {
-	r0, _, e1 := Syscall6(SYS_ACCEPT4, uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)), uintptr(flags), 0, 0)
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_accept4_trampoline), uintptr(fd), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)), uintptr(flags), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -281,6 +354,10 @@ func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int
 	return
 }
 
+func libc_accept4_trampoline()
+
+//go:cgo_import_dynamic libc_accept4 accept4 "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getdents(fd int, buf []byte) (n int, err error) {
@@ -290,7 +367,7 @@ func getdents(fd int, buf []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_GETDENTS, uintptr(fd), uintptr(_p0), uintptr(len(buf)))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_getdents_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(buf)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -298,6 +375,10 @@ func getdents(fd int, buf []byte) (n int, err error) {
 	return
 }
 
+func libc_getdents_trampoline()
+
+//go:cgo_import_dynamic libc_getdents getdents "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Access(path string, mode uint32) (err error) {
@@ -306,23 +387,31 @@ func Access(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_ACCESS, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_access_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_access_trampoline()
+
+//go:cgo_import_dynamic libc_access access "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Adjtime(delta *Timeval, olddelta *Timeval) (err error) {
-	_, _, e1 := Syscall(SYS_ADJTIME, uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_adjtime_trampoline), uintptr(unsafe.Pointer(delta)), uintptr(unsafe.Pointer(olddelta)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_adjtime_trampoline()
+
+//go:cgo_import_dynamic libc_adjtime adjtime "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Chdir(path string) (err error) {
@@ -331,13 +420,17 @@ func Chdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_chdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_chdir_trampoline()
+
+//go:cgo_import_dynamic libc_chdir chdir "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Chflags(path string, flags int) (err error) {
@@ -346,13 +439,17 @@ func Chflags(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_CHFLAGS, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_chflags_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_chflags_trampoline()
+
+//go:cgo_import_dynamic libc_chflags chflags "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Chmod(path string, mode uint32) (err error) {
@@ -361,13 +458,17 @@ func Chmod(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_CHMOD, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_chmod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_chmod_trampoline()
+
+//go:cgo_import_dynamic libc_chmod chmod "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Chown(path string, uid int, gid int) (err error) {
@@ -376,13 +477,17 @@ func Chown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_CHOWN, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_chown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_chown_trampoline()
+
+//go:cgo_import_dynamic libc_chown chown "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Chroot(path string) (err error) {
@@ -391,27 +496,35 @@ func Chroot(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_CHROOT, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_chroot_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_chroot_trampoline()
+
+//go:cgo_import_dynamic libc_chroot chroot "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Close(fd int) (err error) {
-	_, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_close_trampoline), uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_close_trampoline()
+
+//go:cgo_import_dynamic libc_close close "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_dup_trampoline), uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -419,70 +532,98 @@ func Dup(fd int) (nfd int, err error) {
 	return
 }
 
+func libc_dup_trampoline()
+
+//go:cgo_import_dynamic libc_dup dup "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_dup2_trampoline), uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_dup2_trampoline()
+
+//go:cgo_import_dynamic libc_dup2 dup2 "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchdir(fd int) (err error) {
-	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fchdir_trampoline), uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fchdir_trampoline()
+
+//go:cgo_import_dynamic libc_fchdir fchdir "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchflags(fd int, flags int) (err error) {
-	_, _, e1 := Syscall(SYS_FCHFLAGS, uintptr(fd), uintptr(flags), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fchflags_trampoline), uintptr(fd), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fchflags_trampoline()
+
+//go:cgo_import_dynamic libc_fchflags fchflags "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchmod(fd int, mode uint32) (err error) {
-	_, _, e1 := Syscall(SYS_FCHMOD, uintptr(fd), uintptr(mode), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fchmod_trampoline), uintptr(fd), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fchmod_trampoline()
+
+//go:cgo_import_dynamic libc_fchmod fchmod "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fchown(fd int, uid int, gid int) (err error) {
-	_, _, e1 := Syscall(SYS_FCHOWN, uintptr(fd), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fchown_trampoline), uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fchown_trampoline()
+
+//go:cgo_import_dynamic libc_fchown fchown "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Flock(fd int, how int) (err error) {
-	_, _, e1 := Syscall(SYS_FLOCK, uintptr(fd), uintptr(how), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_flock_trampoline), uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_flock_trampoline()
+
+//go:cgo_import_dynamic libc_flock flock "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fpathconf(fd int, name int) (val int, err error) {
-	r0, _, e1 := Syscall(SYS_FPATHCONF, uintptr(fd), uintptr(name), 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_fpathconf_trampoline), uintptr(fd), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -490,74 +631,106 @@ func Fpathconf(fd int, name int) (val int, err error) {
 	return
 }
 
+func libc_fpathconf_trampoline()
+
+//go:cgo_import_dynamic libc_fpathconf fpathconf "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstat(fd int, stat *Stat_t) (err error) {
-	_, _, e1 := Syscall(SYS_FSTAT, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fstat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fstat_trampoline()
+
+//go:cgo_import_dynamic libc_fstat fstat "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fstatfs(fd int, stat *Statfs_t) (err error) {
-	_, _, e1 := Syscall(SYS_FSTATFS, uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fstatfs_trampoline), uintptr(fd), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fstatfs_trampoline()
+
+//go:cgo_import_dynamic libc_fstatfs fstatfs "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fsync(fd int) (err error) {
-	_, _, e1 := Syscall(SYS_FSYNC, uintptr(fd), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_fsync_trampoline), uintptr(fd), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_fsync_trampoline()
+
+//go:cgo_import_dynamic libc_fsync fsync "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Ftruncate(fd int, length int64) (err error) {
-	_, _, e1 := Syscall6(SYS_FTRUNCATE, uintptr(fd), 0, uintptr(length), uintptr(length>>32), 0, 0)
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_ftruncate_trampoline), uintptr(fd), 0, uintptr(length), uintptr(length>>32), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_ftruncate_trampoline()
+
+//go:cgo_import_dynamic libc_ftruncate ftruncate "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getegid() (egid int) {
-	r0, _, _ := RawSyscall(SYS_GETEGID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getegid_trampoline), 0, 0, 0)
 	egid = int(r0)
 	return
 }
 
+func libc_getegid_trampoline()
+
+//go:cgo_import_dynamic libc_getegid getegid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Geteuid() (uid int) {
-	r0, _, _ := RawSyscall(SYS_GETEUID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_geteuid_trampoline), 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
+func libc_geteuid_trampoline()
+
+//go:cgo_import_dynamic libc_geteuid geteuid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getgid() (gid int) {
-	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getgid_trampoline), 0, 0, 0)
 	gid = int(r0)
 	return
 }
 
+func libc_getgid_trampoline()
+
+//go:cgo_import_dynamic libc_getgid getgid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgid(pid int) (pgid int, err error) {
-	r0, _, e1 := RawSyscall(SYS_GETPGID, uintptr(pid), 0, 0)
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getpgid_trampoline), uintptr(pid), 0, 0)
 	pgid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -565,34 +738,50 @@ func Getpgid(pid int) (pgid int, err error) {
 	return
 }
 
+func libc_getpgid_trampoline()
+
+//go:cgo_import_dynamic libc_getpgid getpgid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpgrp() (pgrp int) {
-	r0, _, _ := RawSyscall(SYS_GETPGRP, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getpgrp_trampoline), 0, 0, 0)
 	pgrp = int(r0)
 	return
 }
 
+func libc_getpgrp_trampoline()
+
+//go:cgo_import_dynamic libc_getpgrp getpgrp "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpid() (pid int) {
-	r0, _, _ := RawSyscall(SYS_GETPID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getpid_trampoline), 0, 0, 0)
 	pid = int(r0)
 	return
 }
 
+func libc_getpid_trampoline()
+
+//go:cgo_import_dynamic libc_getpid getpid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getppid() (ppid int) {
-	r0, _, _ := RawSyscall(SYS_GETPPID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getppid_trampoline), 0, 0, 0)
 	ppid = int(r0)
 	return
 }
 
+func libc_getppid_trampoline()
+
+//go:cgo_import_dynamic libc_getppid getppid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getpriority(which int, who int) (prio int, err error) {
-	r0, _, e1 := Syscall(SYS_GETPRIORITY, uintptr(which), uintptr(who), 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_getpriority_trampoline), uintptr(which), uintptr(who), 0)
 	prio = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -600,30 +789,42 @@ func Getpriority(which int, who int) (prio int, err error) {
 	return
 }
 
+func libc_getpriority_trampoline()
+
+//go:cgo_import_dynamic libc_getpriority getpriority "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := RawSyscall(SYS_GETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_getrlimit_trampoline()
+
+//go:cgo_import_dynamic libc_getrlimit getrlimit "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getrusage(who int, rusage *Rusage) (err error) {
-	_, _, e1 := RawSyscall(SYS_GETRUSAGE, uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getrusage_trampoline), uintptr(who), uintptr(unsafe.Pointer(rusage)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_getrusage_trampoline()
+
+//go:cgo_import_dynamic libc_getrusage getrusage "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getsid(pid int) (sid int, err error) {
-	r0, _, e1 := RawSyscall(SYS_GETSID, uintptr(pid), 0, 0)
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getsid_trampoline), uintptr(pid), 0, 0)
 	sid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -631,46 +832,66 @@ func Getsid(pid int) (sid int, err error) {
 	return
 }
 
+func libc_getsid_trampoline()
+
+//go:cgo_import_dynamic libc_getsid getsid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Gettimeofday(tv *Timeval) (err error) {
-	_, _, e1 := RawSyscall(SYS_GETTIMEOFDAY, uintptr(unsafe.Pointer(tv)), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_gettimeofday_trampoline), uintptr(unsafe.Pointer(tv)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_gettimeofday_trampoline()
+
+//go:cgo_import_dynamic libc_gettimeofday gettimeofday "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Getuid() (uid int) {
-	r0, _, _ := RawSyscall(SYS_GETUID, 0, 0, 0)
+	r0, _, _ := rawSyscall(abi.FuncPCABI0(libc_getuid_trampoline), 0, 0, 0)
 	uid = int(r0)
 	return
 }
 
+func libc_getuid_trampoline()
+
+//go:cgo_import_dynamic libc_getuid getuid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Issetugid() (tainted bool) {
-	r0, _, _ := Syscall(SYS_ISSETUGID, 0, 0, 0)
+	r0, _, _ := syscall(abi.FuncPCABI0(libc_issetugid_trampoline), 0, 0, 0)
 	tainted = bool(r0 != 0)
 	return
 }
 
+func libc_issetugid_trampoline()
+
+//go:cgo_import_dynamic libc_issetugid issetugid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Kill(pid int, signum Signal) (err error) {
-	_, _, e1 := Syscall(SYS_KILL, uintptr(pid), uintptr(signum), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_kill_trampoline), uintptr(pid), uintptr(signum), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_kill_trampoline()
+
+//go:cgo_import_dynamic libc_kill kill "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Kqueue() (fd int, err error) {
-	r0, _, e1 := Syscall(SYS_KQUEUE, 0, 0, 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_kqueue_trampoline), 0, 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -678,6 +899,10 @@ func Kqueue() (fd int, err error) {
 	return
 }
 
+func libc_kqueue_trampoline()
+
+//go:cgo_import_dynamic libc_kqueue kqueue "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Lchown(path string, uid int, gid int) (err error) {
@@ -686,13 +911,17 @@ func Lchown(path string, uid int, gid int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_LCHOWN, uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_lchown_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(uid), uintptr(gid))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_lchown_trampoline()
+
+//go:cgo_import_dynamic libc_lchown lchown "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Link(path string, link string) (err error) {
@@ -706,23 +935,31 @@ func Link(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_LINK, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_link_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_link_trampoline()
+
+//go:cgo_import_dynamic libc_link link "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Listen(s int, backlog int) (err error) {
-	_, _, e1 := Syscall(SYS_LISTEN, uintptr(s), uintptr(backlog), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_listen_trampoline), uintptr(s), uintptr(backlog), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_listen_trampoline()
+
+//go:cgo_import_dynamic libc_listen listen "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Lstat(path string, stat *Stat_t) (err error) {
@@ -731,13 +968,17 @@ func Lstat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_LSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_lstat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_lstat_trampoline()
+
+//go:cgo_import_dynamic libc_lstat lstat "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Mkdir(path string, mode uint32) (err error) {
@@ -746,13 +987,17 @@ func Mkdir(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_MKDIR, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_mkdir_trampoline()
+
+//go:cgo_import_dynamic libc_mkdir mkdir "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Mkfifo(path string, mode uint32) (err error) {
@@ -761,13 +1006,17 @@ func Mkfifo(path string, mode uint32) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_MKFIFO, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_mkfifo_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_mkfifo_trampoline()
+
+//go:cgo_import_dynamic libc_mkfifo mkfifo "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Mknod(path string, mode uint32, dev int) (err error) {
@@ -776,23 +1025,31 @@ func Mknod(path string, mode uint32, dev int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_MKNOD, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_mknod_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(dev))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_mknod_trampoline()
+
+//go:cgo_import_dynamic libc_mknod mknod "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
-	_, _, e1 := Syscall(SYS_NANOSLEEP, uintptr(unsafe.Pointer(time)), uintptr(unsafe.Pointer(leftover)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_nanosleep_trampoline), uintptr(unsafe.Pointer(time)), uintptr(unsafe.Pointer(leftover)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_nanosleep_trampoline()
+
+//go:cgo_import_dynamic libc_nanosleep nanosleep "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Open(path string, mode int, perm uint32) (fd int, err error) {
@@ -801,7 +1058,7 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_OPEN, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_open_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
 	fd = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -809,6 +1066,10 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
 	return
 }
 
+func libc_open_trampoline()
+
+//go:cgo_import_dynamic libc_open open "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Pathconf(path string, name int) (val int, err error) {
@@ -817,7 +1078,7 @@ func Pathconf(path string, name int) (val int, err error) {
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_PATHCONF, uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_pathconf_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(name), 0)
 	val = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -825,6 +1086,10 @@ func Pathconf(path string, name int) (val int, err error) {
 	return
 }
 
+func libc_pathconf_trampoline()
+
+//go:cgo_import_dynamic libc_pathconf pathconf "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
@@ -834,7 +1099,7 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_pread_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -842,6 +1107,10 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
+func libc_pread_trampoline()
+
+//go:cgo_import_dynamic libc_pread pread "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
@@ -851,7 +1120,7 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_pwrite_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -859,6 +1128,10 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	return
 }
 
+func libc_pwrite_trampoline()
+
+//go:cgo_import_dynamic libc_pwrite pwrite "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func read(fd int, p []byte) (n int, err error) {
@@ -868,7 +1141,7 @@ func read(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_READ, uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_read_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -876,6 +1149,10 @@ func read(fd int, p []byte) (n int, err error) {
 	return
 }
 
+func libc_read_trampoline()
+
+//go:cgo_import_dynamic libc_read read "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Readlink(path string, buf []byte) (n int, err error) {
@@ -890,7 +1167,7 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	} else {
 		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_READLINK, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_readlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(buf)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -898,6 +1175,10 @@ func Readlink(path string, buf []byte) (n int, err error) {
 	return
 }
 
+func libc_readlink_trampoline()
+
+//go:cgo_import_dynamic libc_readlink readlink "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Rename(from string, to string) (err error) {
@@ -911,13 +1192,17 @@ func Rename(from string, to string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_RENAME, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_rename_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_rename_trampoline()
+
+//go:cgo_import_dynamic libc_rename rename "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Revoke(path string) (err error) {
@@ -926,13 +1211,17 @@ func Revoke(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_REVOKE, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_revoke_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_revoke_trampoline()
+
+//go:cgo_import_dynamic libc_revoke revoke "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Rmdir(path string) (err error) {
@@ -941,64 +1230,73 @@ func Rmdir(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_RMDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_rmdir_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func libc_rmdir_trampoline()
 
-func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
-	r0, r1, e1 := Syscall6(SYS_LSEEK, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), uintptr(whence), 0)
-	newoffset = int64(int64(r1)<<32 | int64(r0))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
+//go:cgo_import_dynamic libc_rmdir rmdir "libc.so"
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Select(n int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (err error) {
-	_, _, e1 := Syscall6(SYS_SELECT, uintptr(n), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_select_trampoline), uintptr(n), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_select_trampoline()
+
+//go:cgo_import_dynamic libc_select select "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setegid(egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETEGID, uintptr(egid), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setegid_trampoline), uintptr(egid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setegid_trampoline()
+
+//go:cgo_import_dynamic libc_setegid setegid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Seteuid(euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETEUID, uintptr(euid), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_seteuid_trampoline), uintptr(euid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_seteuid_trampoline()
+
+//go:cgo_import_dynamic libc_seteuid seteuid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setgid(gid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGID, uintptr(gid), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setgid_trampoline), uintptr(gid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setgid_trampoline()
+
+//go:cgo_import_dynamic libc_setgid setgid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setlogin(name string) (err error) {
@@ -1007,67 +1305,91 @@ func Setlogin(name string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_SETLOGIN, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_setlogin_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setlogin_trampoline()
+
+//go:cgo_import_dynamic libc_setlogin setlogin "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpgid(pid int, pgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETPGID, uintptr(pid), uintptr(pgid), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setpgid_trampoline), uintptr(pid), uintptr(pgid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setpgid_trampoline()
+
+//go:cgo_import_dynamic libc_setpgid setpgid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setpriority(which int, who int, prio int) (err error) {
-	_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_setpriority_trampoline), uintptr(which), uintptr(who), uintptr(prio))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setpriority_trampoline()
+
+//go:cgo_import_dynamic libc_setpriority setpriority "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setregid_trampoline), uintptr(rgid), uintptr(egid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setregid_trampoline()
+
+//go:cgo_import_dynamic libc_setregid setregid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setreuid_trampoline), uintptr(ruid), uintptr(euid), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setreuid_trampoline()
+
+//go:cgo_import_dynamic libc_setreuid setreuid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setrlimit(which int, lim *Rlimit) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setrlimit_trampoline), uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setrlimit_trampoline()
+
+//go:cgo_import_dynamic libc_setrlimit setrlimit "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setsid() (pid int, err error) {
-	r0, _, e1 := RawSyscall(SYS_SETSID, 0, 0, 0)
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setsid_trampoline), 0, 0, 0)
 	pid = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1075,26 +1397,38 @@ func Setsid() (pid int, err error) {
 	return
 }
 
+func libc_setsid_trampoline()
+
+//go:cgo_import_dynamic libc_setsid setsid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Settimeofday(tp *Timeval) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETTIMEOFDAY, uintptr(unsafe.Pointer(tp)), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_settimeofday_trampoline), uintptr(unsafe.Pointer(tp)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_settimeofday_trampoline()
+
+//go:cgo_import_dynamic libc_settimeofday settimeofday "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Setuid(uid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETUID, uintptr(uid), 0, 0)
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_setuid_trampoline), uintptr(uid), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_setuid_trampoline()
+
+//go:cgo_import_dynamic libc_setuid setuid "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Stat(path string, stat *Stat_t) (err error) {
@@ -1103,13 +1437,17 @@ func Stat(path string, stat *Stat_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_stat_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_stat_trampoline()
+
+//go:cgo_import_dynamic libc_stat stat "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Statfs(path string, stat *Statfs_t) (err error) {
@@ -1118,13 +1456,17 @@ func Statfs(path string, stat *Statfs_t) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_STATFS, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_statfs_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_statfs_trampoline()
+
+//go:cgo_import_dynamic libc_statfs statfs "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Symlink(path string, link string) (err error) {
@@ -1138,23 +1480,31 @@ func Symlink(path string, link string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_SYMLINK, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_symlink_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_symlink_trampoline()
+
+//go:cgo_import_dynamic libc_symlink symlink "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Sync() (err error) {
-	_, _, e1 := Syscall(SYS_SYNC, 0, 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_sync_trampoline), 0, 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_sync_trampoline()
+
+//go:cgo_import_dynamic libc_sync sync "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Truncate(path string, length int64) (err error) {
@@ -1163,21 +1513,29 @@ func Truncate(path string, length int64) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall6(SYS_TRUNCATE, uintptr(unsafe.Pointer(_p0)), 0, uintptr(length), uintptr(length>>32), 0, 0)
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_truncate_trampoline), uintptr(unsafe.Pointer(_p0)), 0, uintptr(length), uintptr(length>>32), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_truncate_trampoline()
+
+//go:cgo_import_dynamic libc_truncate truncate "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Umask(newmask int) (oldmask int) {
-	r0, _, _ := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
+	r0, _, _ := syscall(abi.FuncPCABI0(libc_umask_trampoline), uintptr(newmask), 0, 0)
 	oldmask = int(r0)
 	return
 }
 
+func libc_umask_trampoline()
+
+//go:cgo_import_dynamic libc_umask umask "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Unlink(path string) (err error) {
@@ -1186,13 +1544,17 @@ func Unlink(path string) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_UNLINK, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_unlink_trampoline), uintptr(unsafe.Pointer(_p0)), 0, 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_unlink_trampoline()
+
+//go:cgo_import_dynamic libc_unlink unlink "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Unmount(path string, flags int) (err error) {
@@ -1201,13 +1563,17 @@ func Unmount(path string, flags int) (err error) {
 	if err != nil {
 		return
 	}
-	_, _, e1 := Syscall(SYS_UNMOUNT, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_unmount_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_unmount_trampoline()
+
+//go:cgo_import_dynamic libc_unmount unmount "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func write(fd int, p []byte) (n int, err error) {
@@ -1217,7 +1583,7 @@ func write(fd int, p []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_WRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_write_trampoline), uintptr(fd), uintptr(_p0), uintptr(len(p)))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1225,10 +1591,14 @@ func write(fd int, p []byte) (n int, err error) {
 	return
 }
 
+func libc_write_trampoline()
+
+//go:cgo_import_dynamic libc_write write "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error) {
-	r0, _, e1 := Syscall9(SYS_MMAP, uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), 0, uintptr(pos), uintptr(pos>>32), 0)
+	r0, _, e1 := syscall9(abi.FuncPCABI0(libc_mmap_trampoline), uintptr(addr), uintptr(length), uintptr(prot), uintptr(flag), uintptr(fd), 0, uintptr(pos), uintptr(pos>>32), 0)
 	ret = uintptr(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1236,20 +1606,62 @@ func mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (
 	return
 }
 
+func libc_mmap_trampoline()
+
+//go:cgo_import_dynamic libc_mmap mmap "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func munmap(addr uintptr, length uintptr) (err error) {
-	_, _, e1 := Syscall(SYS_MUNMAP, uintptr(addr), uintptr(length), 0)
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_munmap_trampoline), uintptr(addr), uintptr(length), 0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_munmap_trampoline()
+
+//go:cgo_import_dynamic libc_munmap munmap "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_utimensat_trampoline), uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)), uintptr(flag), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_utimensat_trampoline()
+
+//go:cgo_import_dynamic libc_utimensat utimensat "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func directSyscall(trap uintptr, a1 uintptr, a2 uintptr, a3 uintptr, a4 uintptr, a5 uintptr) (ret uintptr, err error) {
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_syscall_trampoline), uintptr(trap), uintptr(a1), uintptr(a2), uintptr(a3), uintptr(a4), uintptr(a5))
+	ret = uintptr(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_syscall_trampoline()
+
+//go:cgo_import_dynamic libc_syscall syscall "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := Syscall(SYS_READ, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1260,7 +1672,7 @@ func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := Syscall(SYS_WRITE, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_write_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -1270,19 +1682,19 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)), uintptr(flag), 0, 0)
+func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
+	r0, r1, e1 := syscall6X(abi.FuncPCABI0(libc_lseek_trampoline), uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), uintptr(whence), 0)
+	newoffset = int64(int64(r1)<<32 | int64(r0))
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
 
+func libc_lseek_trampoline()
+
+//go:cgo_import_dynamic libc_lseek lseek "libc.so"
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getcwd(buf []byte) (n int, err error) {
@@ -1292,10 +1704,195 @@ func getcwd(buf []byte) (n int, err error) {
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_getcwd_trampoline), uintptr(_p0), uintptr(len(buf)), 0)
 	n = int(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}
 	return
 }
+
+func libc_getcwd_trampoline()
+
+//go:cgo_import_dynamic libc_getcwd getcwd "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) {
+	var _p0 unsafe.Pointer
+	if len(mib) > 0 {
+		_p0 = unsafe.Pointer(&mib[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_sysctl_trampoline), uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_sysctl_trampoline()
+
+//go:cgo_import_dynamic libc_sysctl sysctl "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func fork() (pid int, err error) {
+	r0, _, e1 := rawSyscall(abi.FuncPCABI0(libc_fork_trampoline), 0, 0, 0)
+	pid = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_fork_trampoline()
+
+//go:cgo_import_dynamic libc_fork fork "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func ioctl(fd int, req int, arg int) (err error) {
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_ioctl_trampoline), uintptr(fd), uintptr(req), uintptr(arg))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_ioctl_trampoline()
+
+//go:cgo_import_dynamic libc_ioctl ioctl "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func execve(path *byte, argv **byte, envp **byte) (err error) {
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_execve_trampoline), uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(argv)), uintptr(unsafe.Pointer(envp)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_execve_trampoline()
+
+//go:cgo_import_dynamic libc_execve execve "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func exit(res int) (err error) {
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_exit_trampoline), uintptr(res), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_exit_trampoline()
+
+//go:cgo_import_dynamic libc_exit exit "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+//go:nosplit
+func ptrace(request int, pid int, addr uintptr, data uintptr) (err error) {
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_ptrace_trampoline), uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_ptrace_trampoline()
+
+//go:cgo_import_dynamic libc_ptrace ptrace "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getentropy(p []byte) (err error) {
+	var _p0 unsafe.Pointer
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_getentropy_trampoline), uintptr(_p0), uintptr(len(p)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_getentropy_trampoline()
+
+//go:cgo_import_dynamic libc_getentropy getentropy "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func fstatat(fd int, path string, stat *Stat_t, flags int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := syscall6(abi.FuncPCABI0(libc_fstatat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_fstatat_trampoline()
+
+//go:cgo_import_dynamic libc_fstatat fstatat "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func fcntlPtr(fd int, cmd int, arg unsafe.Pointer) (val int, err error) {
+	r0, _, e1 := syscall(abi.FuncPCABI0(libc_fcntl_trampoline), uintptr(fd), uintptr(cmd), uintptr(arg))
+	val = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func unlinkat(fd int, path string, flags int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := syscall(abi.FuncPCABI0(libc_unlinkat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(flags))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_unlinkat_trampoline()
+
+//go:cgo_import_dynamic libc_unlinkat unlinkat "libc.so"
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func openat(fd int, path string, flags int, perm uint32) (fdret int, err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	r0, _, e1 := syscall6(abi.FuncPCABI0(libc_openat_trampoline), uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(flags), uintptr(perm), 0, 0)
+	fdret = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func libc_openat_trampoline()
+
+//go:cgo_import_dynamic libc_openat openat "libc.so"
diff --git a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.s b/src/syscall/zsyscall_openbsd_arm.s
similarity index 73%
rename from src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.s
rename to src/syscall/zsyscall_openbsd_arm.s
index a99f9c1113e..d33f3aa3e05 100644
--- a/src/cmd/vendor/golang.org/x/sys/unix/zsyscall_darwin_arm.s
+++ b/src/syscall/zsyscall_openbsd_arm.s
@@ -1,9 +1,5 @@
-// go run mkasm_darwin.go arm
+// go run mkasm.go openbsd arm
 // Code generated by the command above; DO NOT EDIT.
-
-//go:build go1.12
-// +build go1.12
-
 #include "textflag.h"
 TEXT ·libc_getgroups_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_getgroups(SB)
@@ -45,52 +41,14 @@ TEXT ·libc_utimes_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_utimes(SB)
 TEXT ·libc_futimes_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_futimes(SB)
-TEXT ·libc_poll_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_poll(SB)
-TEXT ·libc_madvise_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_madvise(SB)
-TEXT ·libc_mlock_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mlock(SB)
-TEXT ·libc_mlockall_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mlockall(SB)
-TEXT ·libc_mprotect_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mprotect(SB)
-TEXT ·libc_msync_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_msync(SB)
-TEXT ·libc_munlock_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_munlock(SB)
-TEXT ·libc_munlockall_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_munlockall(SB)
-TEXT ·libc_pipe_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_pipe(SB)
-TEXT ·libc_getxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getxattr(SB)
-TEXT ·libc_fgetxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fgetxattr(SB)
-TEXT ·libc_setxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setxattr(SB)
-TEXT ·libc_fsetxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fsetxattr(SB)
-TEXT ·libc_removexattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_removexattr(SB)
-TEXT ·libc_fremovexattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fremovexattr(SB)
-TEXT ·libc_listxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_listxattr(SB)
-TEXT ·libc_flistxattr_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_flistxattr(SB)
-TEXT ·libc_setattrlist_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setattrlist(SB)
 TEXT ·libc_fcntl_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fcntl(SB)
-TEXT ·libc_kill_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_kill(SB)
-TEXT ·libc_ioctl_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_ioctl(SB)
-TEXT ·libc_sysctl_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sysctl(SB)
-TEXT ·libc_sendfile_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_sendfile(SB)
+TEXT ·libc_pipe2_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_pipe2(SB)
+TEXT ·libc_accept4_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_accept4(SB)
+TEXT ·libc_getdents_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_getdents(SB)
 TEXT ·libc_access_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_access(SB)
 TEXT ·libc_adjtime_trampoline(SB),NOSPLIT,$0-0
@@ -105,50 +63,32 @@ TEXT ·libc_chown_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_chown(SB)
 TEXT ·libc_chroot_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_chroot(SB)
-TEXT ·libc_clock_gettime_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clock_gettime(SB)
 TEXT ·libc_close_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_close(SB)
-TEXT ·libc_clonefile_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clonefile(SB)
-TEXT ·libc_clonefileat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_clonefileat(SB)
 TEXT ·libc_dup_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_dup(SB)
 TEXT ·libc_dup2_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_dup2(SB)
-TEXT ·libc_exchangedata_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_exchangedata(SB)
-TEXT ·libc_exit_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_exit(SB)
-TEXT ·libc_faccessat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_faccessat(SB)
 TEXT ·libc_fchdir_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fchdir(SB)
 TEXT ·libc_fchflags_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fchflags(SB)
 TEXT ·libc_fchmod_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fchmod(SB)
-TEXT ·libc_fchmodat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchmodat(SB)
 TEXT ·libc_fchown_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fchown(SB)
-TEXT ·libc_fchownat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fchownat(SB)
-TEXT ·libc_fclonefileat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fclonefileat(SB)
 TEXT ·libc_flock_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_flock(SB)
 TEXT ·libc_fpathconf_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fpathconf(SB)
+TEXT ·libc_fstat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_fstat(SB)
+TEXT ·libc_fstatfs_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_fstatfs(SB)
 TEXT ·libc_fsync_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fsync(SB)
 TEXT ·libc_ftruncate_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_ftruncate(SB)
-TEXT ·libc_getcwd_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getcwd(SB)
-TEXT ·libc_getdtablesize_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getdtablesize(SB)
 TEXT ·libc_getegid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_getegid(SB)
 TEXT ·libc_geteuid_trampoline(SB),NOSPLIT,$0-0
@@ -177,28 +117,28 @@ TEXT ·libc_getuid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_getuid(SB)
 TEXT ·libc_issetugid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_issetugid(SB)
+TEXT ·libc_kill_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_kill(SB)
 TEXT ·libc_kqueue_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_kqueue(SB)
 TEXT ·libc_lchown_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_lchown(SB)
 TEXT ·libc_link_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_link(SB)
-TEXT ·libc_linkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_linkat(SB)
 TEXT ·libc_listen_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_listen(SB)
+TEXT ·libc_lstat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_lstat(SB)
 TEXT ·libc_mkdir_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_mkdir(SB)
-TEXT ·libc_mkdirat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_mkdirat(SB)
 TEXT ·libc_mkfifo_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_mkfifo(SB)
 TEXT ·libc_mknod_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_mknod(SB)
+TEXT ·libc_nanosleep_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_nanosleep(SB)
 TEXT ·libc_open_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_open(SB)
-TEXT ·libc_openat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_openat(SB)
 TEXT ·libc_pathconf_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_pathconf(SB)
 TEXT ·libc_pread_trampoline(SB),NOSPLIT,$0-0
@@ -209,18 +149,12 @@ TEXT ·libc_read_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_read(SB)
 TEXT ·libc_readlink_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_readlink(SB)
-TEXT ·libc_readlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_readlinkat(SB)
 TEXT ·libc_rename_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_rename(SB)
-TEXT ·libc_renameat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_renameat(SB)
 TEXT ·libc_revoke_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_revoke(SB)
 TEXT ·libc_rmdir_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_rmdir(SB)
-TEXT ·libc_lseek_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_lseek(SB)
 TEXT ·libc_select_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_select(SB)
 TEXT ·libc_setegid_trampoline(SB),NOSPLIT,$0-0
@@ -235,8 +169,6 @@ TEXT ·libc_setpgid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_setpgid(SB)
 TEXT ·libc_setpriority_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_setpriority(SB)
-TEXT ·libc_setprivexec_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_setprivexec(SB)
 TEXT ·libc_setregid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_setregid(SB)
 TEXT ·libc_setreuid_trampoline(SB),NOSPLIT,$0-0
@@ -249,22 +181,20 @@ TEXT ·libc_settimeofday_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_settimeofday(SB)
 TEXT ·libc_setuid_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_setuid(SB)
+TEXT ·libc_stat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_stat(SB)
+TEXT ·libc_statfs_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_statfs(SB)
 TEXT ·libc_symlink_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_symlink(SB)
-TEXT ·libc_symlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_symlinkat(SB)
 TEXT ·libc_sync_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_sync(SB)
 TEXT ·libc_truncate_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_truncate(SB)
 TEXT ·libc_umask_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_umask(SB)
-TEXT ·libc_undelete_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_undelete(SB)
 TEXT ·libc_unlink_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_unlink(SB)
-TEXT ·libc_unlinkat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_unlinkat(SB)
 TEXT ·libc_unmount_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_unmount(SB)
 TEXT ·libc_write_trampoline(SB),NOSPLIT,$0-0
@@ -273,17 +203,31 @@ TEXT ·libc_mmap_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_mmap(SB)
 TEXT ·libc_munmap_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_munmap(SB)
-TEXT ·libc_fstat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fstat(SB)
+TEXT ·libc_utimensat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_utimensat(SB)
+TEXT ·libc_syscall_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_syscall(SB)
+TEXT ·libc_lseek_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_lseek(SB)
+TEXT ·libc_getcwd_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_getcwd(SB)
+TEXT ·libc_sysctl_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_sysctl(SB)
+TEXT ·libc_fork_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_fork(SB)
+TEXT ·libc_ioctl_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_ioctl(SB)
+TEXT ·libc_execve_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_execve(SB)
+TEXT ·libc_exit_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_exit(SB)
+TEXT ·libc_ptrace_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_ptrace(SB)
+TEXT ·libc_getentropy_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_getentropy(SB)
 TEXT ·libc_fstatat_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_fstatat(SB)
-TEXT ·libc_fstatfs_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_fstatfs(SB)
-TEXT ·libc_getfsstat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_getfsstat(SB)
-TEXT ·libc_lstat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_lstat(SB)
-TEXT ·libc_stat_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_stat(SB)
-TEXT ·libc_statfs_trampoline(SB),NOSPLIT,$0-0
-	JMP	libc_statfs(SB)
+TEXT ·libc_unlinkat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_unlinkat(SB)
+TEXT ·libc_openat_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_openat(SB)
diff --git a/src/syscall/zsyscall_windows.go b/src/syscall/zsyscall_windows.go
index 10d0f54e8c7..7bfff16be6a 100644
--- a/src/syscall/zsyscall_windows.go
+++ b/src/syscall/zsyscall_windows.go
@@ -43,6 +43,7 @@ var (
 	modkernel32 = NewLazyDLL(sysdll.Add("kernel32.dll"))
 	modmswsock  = NewLazyDLL(sysdll.Add("mswsock.dll"))
 	modnetapi32 = NewLazyDLL(sysdll.Add("netapi32.dll"))
+	modntdll    = NewLazyDLL(sysdll.Add("ntdll.dll"))
 	modsecur32  = NewLazyDLL(sysdll.Add("secur32.dll"))
 	modshell32  = NewLazyDLL(sysdll.Add("shell32.dll"))
 	moduserenv  = NewLazyDLL(sysdll.Add("userenv.dll"))
@@ -167,6 +168,7 @@ var (
 	procNetApiBufferFree                   = modnetapi32.NewProc("NetApiBufferFree")
 	procNetGetJoinInformation              = modnetapi32.NewProc("NetGetJoinInformation")
 	procNetUserGetInfo                     = modnetapi32.NewProc("NetUserGetInfo")
+	procRtlGetNtVersionNumbers             = modntdll.NewProc("RtlGetNtVersionNumbers")
 	procGetUserNameExW                     = modsecur32.NewProc("GetUserNameExW")
 	procTranslateNameW                     = modsecur32.NewProc("TranslateNameW")
 	procCommandLineToArgvW                 = modshell32.NewProc("CommandLineToArgvW")
@@ -1213,6 +1215,11 @@ func NetUserGetInfo(serverName *uint16, userName *uint16, level uint32, buf **by
 	return
 }
 
+func rtlGetNtVersionNumbers(majorVersion *uint32, minorVersion *uint32, buildNumber *uint32) {
+	Syscall(procRtlGetNtVersionNumbers.Addr(), 3, uintptr(unsafe.Pointer(majorVersion)), uintptr(unsafe.Pointer(minorVersion)), uintptr(unsafe.Pointer(buildNumber)))
+	return
+}
+
 func GetUserNameEx(nameFormat uint32, nameBuffre *uint16, nSize *uint32) (err error) {
 	r1, _, e1 := Syscall(procGetUserNameExW.Addr(), 3, uintptr(nameFormat), uintptr(unsafe.Pointer(nameBuffre)), uintptr(unsafe.Pointer(nSize)))
 	if r1&0xff == 0 {
diff --git a/src/testing/testing.go b/src/testing/testing.go
index 85a7fec65f1..a19238d31e2 100644
--- a/src/testing/testing.go
+++ b/src/testing/testing.go
@@ -233,6 +233,8 @@
 //		os.Exit(m.Run())
 //	}
 //
+// TestMain is a low-level primitive and should not be necessary for casual
+// testing needs, where ordinary test functions suffice.
 package testing
 
 import (
@@ -252,6 +254,8 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var initRan bool
@@ -642,6 +646,7 @@ type TB interface {
 	Log(args ...interface{})
 	Logf(format string, args ...interface{})
 	Name() string
+	Setenv(key, value string)
 	Skip(args ...interface{})
 	SkipNow()
 	Skipf(format string, args ...interface{})
@@ -675,7 +680,11 @@ type T struct {
 
 func (c *common) private() {}
 
-// Name returns the name of the running test or benchmark.
+// Name returns the name of the running (sub-) test or benchmark.
+//
+// The name will include the name of the test along with the names of
+// any nested sub-tests. If two sibling sub-tests have the same name,
+// Name will append a suffix to guarantee the returned name is unique.
 func (c *common) Name() string {
 	return c.name
 }
@@ -908,11 +917,6 @@ func (c *common) Cleanup(f func()) {
 	c.cleanups = append(c.cleanups, fn)
 }
 
-var tempDirReplacer struct {
-	sync.Once
-	r *strings.Replacer
-}
-
 // TempDir returns a temporary directory for the test to use.
 // The directory is automatically removed by Cleanup when the test and
 // all its subtests complete.
@@ -936,13 +940,26 @@ func (c *common) TempDir() string {
 	if nonExistent {
 		c.Helper()
 
-		// os.MkdirTemp doesn't like path separators in its pattern,
-		// so mangle the name to accommodate subtests.
-		tempDirReplacer.Do(func() {
-			tempDirReplacer.r = strings.NewReplacer("/", "_", "\\", "_", ":", "_")
-		})
-		pattern := tempDirReplacer.r.Replace(c.Name())
-
+		// Drop unusual characters (such as path separators or
+		// characters interacting with globs) from the directory name to
+		// avoid surprising os.MkdirTemp behavior.
+		mapper := func(r rune) rune {
+			if r < utf8.RuneSelf {
+				const allowed = "!#$%&()+,-.=@^_{}~ "
+				if '0' <= r && r <= '9' ||
+					'a' <= r && r <= 'z' ||
+					'A' <= r && r <= 'Z' {
+					return r
+				}
+				if strings.ContainsRune(allowed, r) {
+					return r
+				}
+			} else if unicode.IsLetter(r) || unicode.IsNumber(r) {
+				return r
+			}
+			return -1
+		}
+		pattern := strings.Map(mapper, c.Name())
 		c.tempDir, c.tempDirErr = os.MkdirTemp("", pattern)
 		if c.tempDirErr == nil {
 			c.Cleanup(func() {
diff --git a/src/testing/testing_test.go b/src/testing/testing_test.go
index 55a4df4739e..08ae23991f1 100644
--- a/src/testing/testing_test.go
+++ b/src/testing/testing_test.go
@@ -58,6 +58,9 @@ func TestTempDir(t *testing.T) {
 	t.Run("test:subtest", testTempDir)
 	t.Run("test/..", testTempDir)
 	t.Run("../test", testTempDir)
+	t.Run("test[]", testTempDir)
+	t.Run("test*", testTempDir)
+	t.Run("äöüéè", testTempDir)
 }
 
 func testTempDir(t *testing.T) {
@@ -74,7 +77,7 @@ func testTempDir(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			t.Errorf("directory %q stil exists: %v, isDir=%v", dir, fi, fi.IsDir())
+			t.Errorf("directory %q still exists: %v, isDir=%v", dir, fi, fi.IsDir())
 		default:
 			if !t.Failed() {
 				t.Fatal("never received dir channel")
@@ -108,6 +111,11 @@ func testTempDir(t *testing.T) {
 	if len(files) > 0 {
 		t.Errorf("unexpected %d files in TempDir: %v", len(files), files)
 	}
+
+	glob := filepath.Join(dir, "*.txt")
+	if _, err := filepath.Glob(glob); err != nil {
+		t.Error(err)
+	}
 }
 
 func TestSetenv(t *testing.T) {
diff --git a/src/text/scanner/scanner.go b/src/text/scanner/scanner.go
index e0847a72396..c5fc4ff93b9 100644
--- a/src/text/scanner/scanner.go
+++ b/src/text/scanner/scanner.go
@@ -23,7 +23,7 @@ import (
 	"unicode/utf8"
 )
 
-// A source position is represented by a Position value.
+// Position is a value that represents a source position.
 // A position is valid if Line > 0.
 type Position struct {
 	Filename string // filename, if any
diff --git a/src/time/format.go b/src/time/format.go
index f6dc8ee621b..f4b4f48142f 100644
--- a/src/time/format.go
+++ b/src/time/format.go
@@ -7,58 +7,18 @@ package time
 import "errors"
 
 // These are predefined layouts for use in Time.Format and time.Parse.
-// The reference time used in the layouts is the specific time:
-//	Mon Jan 2 15:04:05 MST 2006
-// which is Unix time 1136239445. Since MST is GMT-0700,
-// the reference time can be thought of as
+// The reference time used in these layouts is the specific time stamp:
 //	01/02 03:04:05PM '06 -0700
-// To define your own format, write down what the reference time would look
-// like formatted your way; see the values of constants like ANSIC,
-// StampMicro or Kitchen for examples. The model is to demonstrate what the
-// reference time looks like so that the Format and Parse methods can apply
-// the same transformation to a general time value.
+// (January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
+// That value is recorded as the constant named Layout, listed below. As a Unix
+// time, this is 1136239445. Since MST is GMT-0700, the reference would be
+// printed by the Unix date command as:
+//	Mon Jan 2 15:04:05 MST 2006
+// It is a regrettable historic error that the date uses the American convention
+// of putting the numerical month before the day.
 //
-// Some valid layouts are invalid time values for time.Parse, due to formats
-// such as _ for space padding and Z for zone information.
-//
-// Within the format string, an underscore _ represents a space that may be
-// replaced by a digit if the following number (a day) has two digits; for
-// compatibility with fixed-width Unix time formats.
-//
-// A decimal point followed by one or more zeros represents a fractional
-// second, printed to the given number of decimal places.
-// Either a comma or decimal point followed by one or more nines represents
-// a fractional second, printed to the given number of decimal places, with
-// trailing zeros removed.
-// When parsing (only), the input may contain a fractional second
-// field immediately after the seconds field, even if the layout does not
-// signify its presence. In that case either a comma or a decimal point
-// followed by a maximal series of digits is parsed as a fractional second.
-//
-// Numeric time zone offsets format as follows:
-//	-0700  ±hhmm
-//	-07:00 ±hh:mm
-//	-07    ±hh
-// Replacing the sign in the format with a Z triggers
-// the ISO 8601 behavior of printing Z instead of an
-// offset for the UTC zone. Thus:
-//	Z0700  Z or ±hhmm
-//	Z07:00 Z or ±hh:mm
-//	Z07    Z or ±hh
-//
-// The recognized day of week formats are "Mon" and "Monday".
-// The recognized month formats are "Jan" and "January".
-//
-// The formats 2, _2, and 02 are unpadded, space-padded, and zero-padded
-// day of month. The formats __2 and 002 are space-padded and zero-padded
-// three-character day of year; there is no unpadded day of year format.
-//
-// Text in the format string that is not recognized as part of the reference
-// time is echoed verbatim during Format and expected to appear verbatim
-// in the input to Parse.
-//
-// The executable example for Time.Format demonstrates the working
-// of the layout string in detail and is a good reference.
+// The example for Time.Format demonstrates the working of the layout string
+// in detail and is a good reference.
 //
 // Note that the RFC822, RFC850, and RFC1123 formats should be applied
 // only to local times. Applying them to UTC times will use "UTC" as the
@@ -71,7 +31,65 @@ import "errors"
 // permitted by the RFCs and they do accept time formats not formally defined.
 // The RFC3339Nano format removes trailing zeros from the seconds field
 // and thus may not sort correctly once formatted.
+//
+// Most programs can use one of the defined constants as the layout passed to
+// Format or Parse. The rest of this comment can be ignored unless you are
+// creating a custom layout string.
+//
+// To define your own format, write down what the reference time would look like
+// formatted your way; see the values of constants like ANSIC, StampMicro or
+// Kitchen for examples. The model is to demonstrate what the reference time
+// looks like so that the Format and Parse methods can apply the same
+// transformation to a general time value.
+//
+// Here is a summary of the components of a layout string. Each element shows by
+// example the formatting of an element of the reference time. Only these values
+// are recognized. Text in the layout string that is not recognized as part of
+// the reference time is echoed verbatim during Format and expected to appear
+// verbatim in the input to Parse.
+//
+//	Year: "2006" "06"
+//	Month: "Jan" "January"
+//	Textual day of the week: "Mon" "Monday"
+//	Numeric day of the month: "2" "_2" "02"
+//	Numeric day of the year: "__2" "002"
+//	Hour: "15" "3" "03" (PM or AM)
+//	Minute: "4" "04"
+//	Second: "5" "05"
+//	AM/PM mark: "PM"
+//
+// Numeric time zone offsets format as follows:
+//	"-0700"  ±hhmm
+//	"-07:00" ±hh:mm
+//	"-07"    ±hh
+// Replacing the sign in the format with a Z triggers
+// the ISO 8601 behavior of printing Z instead of an
+// offset for the UTC zone. Thus:
+//	"Z0700"  Z or ±hhmm
+//	"Z07:00" Z or ±hh:mm
+//	"Z07"    Z or ±hh
+//
+// Within the format string, the underscores in "_2" and "__2" represent spaces
+// that may be replaced by digits if the following number has multiple digits,
+// for compatibility with fixed-width Unix time formats. A leading zero represents
+// a zero-padded value.
+//
+// The formats  and 002 are space-padded and zero-padded
+// three-character day of year; there is no unpadded day of year format.
+//
+// A comma or decimal point followed by one or more zeros represents
+// a fractional second, printed to the given number of decimal places.
+// A comma or decimal point followed by one or more nines represents
+// a fractional second, printed to the given number of decimal places, with
+// trailing zeros removed.
+// For example "15:04:05,000" or "15:04:05.000" formats or parses with
+// millisecond precision.
+//
+// Some valid layouts are invalid time values for time.Parse, due to formats
+// such as _ for space padding and Z for zone information.
+//
 const (
+	Layout      = "01/02 03:04:05PM '06 -0700" // The reference time, in numerical order.
 	ANSIC       = "Mon Jan _2 15:04:05 2006"
 	UnixDate    = "Mon Jan _2 15:04:05 MST 2006"
 	RubyDate    = "Mon Jan 02 15:04:05 -0700 2006"
@@ -531,23 +549,12 @@ func (t Time) GoString() string {
 	return string(buf)
 }
 
-// Format returns a textual representation of the time value formatted
-// according to layout, which defines the format by showing how the reference
-// time, defined to be
-//	Mon Jan 2 15:04:05 -0700 MST 2006
-// would be displayed if it were the value; it serves as an example of the
-// desired output. The same display rules will then be applied to the time
-// value.
+// Format returns a textual representation of the time value formatted according
+// to the layout defined by the argument. See the documentation for the
+// constant called Layout to see how to represent the layout format.
 //
-// A fractional second is represented by adding either a comma or a
-// period and zeros to the end of the seconds section of layout string,
-// as in "15:04:05,000" or "15:04:05.000" to format a time stamp with
-// millisecond precision.
-//
-// Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard
-// and convenient representations of the reference time. For more information
-// about the formats and the definition of the reference time, see the
-// documentation for ANSIC and the other constants defined by this package.
+// The executable example for Time.Format demonstrates the working
+// of the layout string in detail and is a good reference.
 func (t Time) Format(layout string) string {
 	const bufSize = 64
 	var b []byte
@@ -744,8 +751,11 @@ type ParseError struct {
 
 // These are borrowed from unicode/utf8 and strconv and replicate behavior in
 // that package, since we can't take a dependency on either.
-const runeSelf = 0x80
-const lowerhex = "0123456789abcdef"
+const (
+	lowerhex  = "0123456789abcdef"
+	runeSelf  = 0x80
+	runeError = '\uFFFD'
+)
 
 func quote(s string) string {
 	buf := make([]byte, 1, len(s)+2) // slice will be at least len(s) + quotes
@@ -758,7 +768,16 @@ func quote(s string) string {
 			// reproduce strconv.Quote's behavior with full fidelity but
 			// given how rarely we expect to hit these edge cases, speed and
 			// conciseness are better.
-			for j := 0; j < len(string(c)) && j < len(s); j++ {
+			var width int
+			if c == runeError {
+				width = 1
+				if i+2 < len(s) && s[i:i+3] == string(runeError) {
+					width = 3
+				}
+			} else {
+				width = len(string(c))
+			}
+			for j := 0; j < width; j++ {
 				buf = append(buf, `\x`...)
 				buf = append(buf, lowerhex[s[i+j]>>4])
 				buf = append(buf, lowerhex[s[i+j]&0xF])
@@ -855,21 +874,19 @@ func skip(value, prefix string) (string, error) {
 }
 
 // Parse parses a formatted string and returns the time value it represents.
-// The layout defines the format by showing how the reference time,
-// defined to be
-//	Mon Jan 2 15:04:05 -0700 MST 2006
-// would be interpreted if it were the value; it serves as an example of
-// the input format. The same interpretation will then be made to the
-// input string.
+// See the documentation for the constant called Layout to see how to
+// represent the format. The second argument must be parseable using
+// the format string (layout) provided as the first argument.
 //
-// Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard
-// and convenient representations of the reference time. For more information
-// about the formats and the definition of the reference time, see the
-// documentation for ANSIC and the other constants defined by this package.
-// Also, the executable example for Time.Format demonstrates the working
-// of the layout string in detail and is a good reference.
+// The example for Time.Format demonstrates the working of the layout string
+// in detail and is a good reference.
 //
-// Elements omitted from the value are assumed to be zero or, when
+// When parsing (only), the input may contain a fractional second
+// field immediately after the seconds field, even if the layout does not
+// signify its presence. In that case either a comma or a decimal point
+// followed by a maximal series of digits is parsed as a fractional second.
+//
+// Elements omitted from the layout are assumed to be zero or, when
 // zero is impossible, one, so parsing "3:04pm" returns the time
 // corresponding to Jan 1, year 0, 15:04:00 UTC (note that because the year is
 // 0, this time is before the zero Time).
@@ -879,6 +896,8 @@ func skip(value, prefix string) (string, error) {
 // For layouts specifying the two-digit year 06, a value NN >= 69 will be treated
 // as 19NN and a value NN < 69 will be treated as 20NN.
 //
+// The remainder of this comment describes the handling of time zones.
+//
 // In the absence of a time zone indicator, Parse returns a time in UTC.
 //
 // When parsing a time with a zone offset like -0700, if the offset corresponds
diff --git a/src/time/sleep_test.go b/src/time/sleep_test.go
index 6ee0631a855..e0172bf5e0b 100644
--- a/src/time/sleep_test.go
+++ b/src/time/sleep_test.go
@@ -527,6 +527,40 @@ func TestZeroTimer(t *testing.T) {
 	}
 }
 
+// Test that rapidly moving a timer earlier doesn't cause it to get dropped.
+// Issue 47329.
+func TestTimerModifiedEarlier(t *testing.T) {
+	past := Until(Unix(0, 0))
+	count := 1000
+	fail := 0
+	for i := 0; i < count; i++ {
+		timer := NewTimer(Hour)
+		for j := 0; j < 10; j++ {
+			if !timer.Stop() {
+				<-timer.C
+			}
+			timer.Reset(past)
+		}
+
+		deadline := NewTimer(10 * Second)
+		defer deadline.Stop()
+		now := Now()
+		select {
+		case <-timer.C:
+			if since := Since(now); since > 8*Second {
+				t.Errorf("timer took too long (%v)", since)
+				fail++
+			}
+		case <-deadline.C:
+			t.Error("deadline expired")
+		}
+	}
+
+	if fail > 0 {
+		t.Errorf("%d failures", fail)
+	}
+}
+
 // Benchmark timer latency when the thread that creates the timer is busy with
 // other work and the timers must be serviced by other threads.
 // https://golang.org/issue/38860
diff --git a/src/time/time.go b/src/time/time.go
index cd756bbf5f2..4ecc3d82dcc 100644
--- a/src/time/time.go
+++ b/src/time/time.go
@@ -1334,13 +1334,13 @@ func UnixMilli(msec int64) Time {
 }
 
 // UnixMicro returns the local Time corresponding to the given Unix time,
-// usec milliseconds since January 1, 1970 UTC.
+// usec microseconds since January 1, 1970 UTC.
 func UnixMicro(usec int64) Time {
 	return Unix(usec/1e6, (usec%1e6)*1e3)
 }
 
 // IsDST reports whether the time in the configured location is in Daylight Savings Time.
-func (t *Time) IsDST() bool {
+func (t Time) IsDST() bool {
 	_, _, _, _, isDST := t.loc.lookup(t.Unix())
 	return isDST
 }
diff --git a/src/time/time_test.go b/src/time/time_test.go
index f272bbd5587..cea5f2d3f5a 100644
--- a/src/time/time_test.go
+++ b/src/time/time_test.go
@@ -917,6 +917,11 @@ var parseDurationErrorTests = []struct {
 	{".s", `".s"`},
 	{"+.s", `"+.s"`},
 	{"1d", `"1d"`},
+	{"\x85\x85", `"\x85\x85"`},
+	{"\xffff", `"\xffff"`},
+	{"hello \xffff world", `"hello \xffff world"`},
+	{"\uFFFD", `"\xef\xbf\xbd"`},                                             // utf8.RuneError
+	{"\uFFFD hello \uFFFD world", `"\xef\xbf\xbd hello \xef\xbf\xbd world"`}, // utf8.RuneError
 	// overflow
 	{"9223372036854775810ns", `"9223372036854775810ns"`},
 	{"9223372036854775808ns", `"9223372036854775808ns"`},
diff --git a/src/time/tzdata/generate_zipdata.go b/src/time/tzdata/generate_zipdata.go
index 64b5b1b22c2..0869c8458c6 100644
--- a/src/time/tzdata/generate_zipdata.go
+++ b/src/time/tzdata/generate_zipdata.go
@@ -31,8 +31,8 @@ const header = `// Copyright 2020 The Go Authors. All rights reserved.
 
 // For more information, see
 // https://www.iana.org/time-zones
-// ftp://ftp.iana.org/tz/code/tz-link.htm
-// http://tools.ietf.org/html/rfc6557
+// ftp://ftp.iana.org/tz/code/tz-link.html
+// https://datatracker.ietf.org/doc/html/rfc6557
 
 package tzdata
 
diff --git a/src/time/tzdata/zipdata.go b/src/time/tzdata/zipdata.go
index 03b59720e27..60c07840082 100644
--- a/src/time/tzdata/zipdata.go
+++ b/src/time/tzdata/zipdata.go
@@ -11,8 +11,8 @@
 
 // For more information, see
 // https://www.iana.org/time-zones
-// ftp://ftp.iana.org/tz/code/tz-link.htm
-// http://tools.ietf.org/html/rfc6557
+// ftp://ftp.iana.org/tz/code/tz-link.html
+// https://datatracker.ietf.org/doc/html/rfc6557
 
 package tzdata
 
diff --git a/src/unsafe/unsafe.go b/src/unsafe/unsafe.go
index ecbd28c523e..16e3890d0be 100644
--- a/src/unsafe/unsafe.go
+++ b/src/unsafe/unsafe.go
@@ -217,12 +217,17 @@ func Alignof(x ArbitraryType) uintptr
 func Add(ptr Pointer, len IntegerType) Pointer
 
 // The function Slice returns a slice whose underlying array starts at ptr
-// and whose length and capacity are len:
+// and whose length and capacity are len.
+// Slice(ptr, len) is equivalent to
 //
 //	(*[len]ArbitraryType)(unsafe.Pointer(ptr))[:]
 //
+// except that, as a special case, if ptr is nil and len is zero,
+// Slice returns nil.
+//
 // The len argument must be of integer type or an untyped constant.
 // A constant len argument must be non-negative and representable by a value of type int;
 // if it is an untyped constant it is given type int.
-// If ptr is nil or len is negative at run time, a run-time panic occurs.
+// At run time, if len is negative, or if ptr is nil and len is not zero,
+// a run-time panic occurs.
 func Slice(ptr *ArbitraryType, len IntegerType) []ArbitraryType
diff --git a/src/vendor/golang.org/x/net/route/empty.s b/src/vendor/golang.org/x/net/route/empty.s
index bff0231c7d5..90ab4ca3d8e 100644
--- a/src/vendor/golang.org/x/net/route/empty.s
+++ b/src/vendor/golang.org/x/net/route/empty.s
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && go1.12
 // +build darwin,go1.12
 
 // This exists solely so we can linkname in symbols from syscall.
diff --git a/src/vendor/golang.org/x/sys/cpu/cpu.go b/src/vendor/golang.org/x/sys/cpu/cpu.go
index f77701fe868..abbec2d44bf 100644
--- a/src/vendor/golang.org/x/sys/cpu/cpu.go
+++ b/src/vendor/golang.org/x/sys/cpu/cpu.go
@@ -154,14 +154,13 @@ var MIPS64X struct {
 // For ppc64/ppc64le, it is safe to check only for ISA level starting on ISA v3.00,
 // since there are no optional categories. There are some exceptions that also
 // require kernel support to work (DARN, SCV), so there are feature bits for
-// those as well. The minimum processor requirement is POWER8 (ISA 2.07).
-// The struct is padded to avoid false sharing.
+// those as well. The struct is padded to avoid false sharing.
 var PPC64 struct {
 	_        CacheLinePad
 	HasDARN  bool // Hardware random number generator (requires kernel enablement)
 	HasSCV   bool // Syscall vectored (requires kernel enablement)
 	IsPOWER8 bool // ISA v2.07 (POWER8)
-	IsPOWER9 bool // ISA v3.00 (POWER9)
+	IsPOWER9 bool // ISA v3.00 (POWER9), implies IsPOWER8
 	_        CacheLinePad
 }
 
diff --git a/src/vendor/golang.org/x/sys/cpu/cpu_aix.go b/src/vendor/golang.org/x/sys/cpu/cpu_aix.go
index 28b521643b1..8aaeef545a7 100644
--- a/src/vendor/golang.org/x/sys/cpu/cpu_aix.go
+++ b/src/vendor/golang.org/x/sys/cpu/cpu_aix.go
@@ -20,6 +20,7 @@ func archInit() {
 		PPC64.IsPOWER8 = true
 	}
 	if impl&_IMPL_POWER9 != 0 {
+		PPC64.IsPOWER8 = true
 		PPC64.IsPOWER9 = true
 	}
 
diff --git a/src/vendor/modules.txt b/src/vendor/modules.txt
index 5b939af60db..ff01db5cdc7 100644
--- a/src/vendor/modules.txt
+++ b/src/vendor/modules.txt
@@ -8,7 +8,7 @@ golang.org/x/crypto/curve25519
 golang.org/x/crypto/hkdf
 golang.org/x/crypto/internal/subtle
 golang.org/x/crypto/poly1305
-# golang.org/x/net v0.0.0-20210505024714-0287a6fb4125
+# golang.org/x/net v0.0.0-20210510120150-4163338589ed
 ## explicit; go 1.17
 golang.org/x/net/dns/dnsmessage
 golang.org/x/net/http/httpguts
@@ -18,7 +18,7 @@ golang.org/x/net/idna
 golang.org/x/net/lif
 golang.org/x/net/nettest
 golang.org/x/net/route
-# golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6
+# golang.org/x/sys v0.0.0-20210511113859-b0526f3d8744
 ## explicit; go 1.17
 golang.org/x/sys/cpu
 # golang.org/x/text v0.3.7-0.20210503195748-5c7c50ebbd4f
diff --git a/test/bench/go1/regexp_test.go b/test/bench/go1/regexp_test.go
index 3ce9f3a2c67..dd1034fde5d 100644
--- a/test/bench/go1/regexp_test.go
+++ b/test/bench/go1/regexp_test.go
@@ -53,7 +53,7 @@ func BenchmarkRegexpMatchEasy0_32(b *testing.B)  { benchmark(b, easy0, 32<<0) }
 func BenchmarkRegexpMatchEasy0_1K(b *testing.B)  { benchmark(b, easy0, 1<<10) }
 func BenchmarkRegexpMatchEasy1_32(b *testing.B)  { benchmark(b, easy1, 32<<0) }
 func BenchmarkRegexpMatchEasy1_1K(b *testing.B)  { benchmark(b, easy1, 1<<10) }
-func BenchmarkRegexpMatchMedium_32(b *testing.B) { benchmark(b, medium, 1<<0) }
+func BenchmarkRegexpMatchMedium_32(b *testing.B) { benchmark(b, medium, 32<<0) }
 func BenchmarkRegexpMatchMedium_1K(b *testing.B) { benchmark(b, medium, 1<<10) }
 func BenchmarkRegexpMatchHard_32(b *testing.B)   { benchmark(b, hard, 32<<0) }
 func BenchmarkRegexpMatchHard_1K(b *testing.B)   { benchmark(b, hard, 1<<10) }
diff --git a/test/chan/perm.go b/test/chan/perm.go
index 4c94ab7ffae..04046723a4f 100644
--- a/test/chan/perm.go
+++ b/test/chan/perm.go
@@ -66,5 +66,5 @@ func main() {
 	close(c)
 	close(cs)
 	close(cr) // ERROR "receive"
-	close(n)  // ERROR "invalid operation.*non-chan type|must be channel|not a channel"
+	close(n)  // ERROR "invalid operation.*non-chan type|must be channel|non-channel"
 }
diff --git a/test/closure3.dir/main.go b/test/closure3.dir/main.go
index 2fc33753ed7..662a2e967bb 100644
--- a/test/closure3.dir/main.go
+++ b/test/closure3.dir/main.go
@@ -94,10 +94,10 @@ func main() {
 			return x + 2
 		}
 		y, sink = func() (func(int) int, int) { // ERROR "can inline main.func12"
-			return func(x int) int { // ERROR "can inline main.func12"
+			return func(x int) int { // ERROR "func literal does not escape" "can inline main.func12"
 				return x + 1
 			}, 42
-		}() // ERROR "func literal does not escape" "inlining call to main.func12"
+		}() // ERROR "inlining call to main.func12"
 		if y(40) != 41 {
 			ppanic("y(40) != 41")
 		}
@@ -109,10 +109,10 @@ func main() {
 				return x + 2
 			}
 			y, sink = func() (func(int) int, int) { // ERROR "can inline main.func13.2"
-				return func(x int) int { // ERROR "can inline main.func13.2"
+				return func(x int) int { // ERROR  "func literal does not escape" "can inline main.func13.2"
 					return x + 1
 				}, 42
-			}() // ERROR "inlining call to main.func13.2" "func literal does not escape"
+			}() // ERROR "inlining call to main.func13.2"
 			if y(40) != 41 {
 				ppanic("y(40) != 41")
 			}
diff --git a/test/codegen/arithmetic.go b/test/codegen/arithmetic.go
index a27a17f6e11..eb0f338036c 100644
--- a/test/codegen/arithmetic.go
+++ b/test/codegen/arithmetic.go
@@ -202,7 +202,7 @@ func ConstDivs(n1 uint, n2 int) (uint, int) {
 
 	// amd64:"MOVQ\t[$]-1085102592571150095","IMULQ",-"IDIVQ"
 	// 386:"MOVL\t[$]-252645135","IMULL",-"IDIVL"
-	// arm64:`MOVD`,`SMULH`,-`DIV`
+	// arm64:`SMULH`,-`DIV`
 	// arm:`MOVW`,`MUL`,-`.*udiv`
 	b := n2 / 17 // signed
 
@@ -266,7 +266,7 @@ func ConstMods(n1 uint, n2 int) (uint, int) {
 
 	// amd64:"MOVQ\t[$]-1085102592571150095","IMULQ",-"IDIVQ"
 	// 386:"MOVL\t[$]-252645135","IMULL",-"IDIVL"
-	// arm64:`MOVD`,`SMULH`,-`DIV`
+	// arm64:`SMULH`,-`DIV`
 	// arm:`MOVW`,`MUL`,-`.*udiv`
 	b := n2 % 17 // signed
 
diff --git a/test/codegen/clobberdead.go b/test/codegen/clobberdead.go
index f8d964cba68..c490790bb63 100644
--- a/test/codegen/clobberdead.go
+++ b/test/codegen/clobberdead.go
@@ -1,6 +1,6 @@
 // asmcheck -gcflags=-clobberdead
 
-// +build amd64
+// +build amd64 arm64
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -13,15 +13,18 @@ type T [2]*int // contain pointer, not SSA-able (so locals are not registerized)
 var p1, p2, p3 T
 
 func F() {
-	// 3735936685 is 0xdeaddead
+	// 3735936685 is 0xdeaddead. On ARM64 R27 is REGTMP.
 	// clobber x, y at entry. not clobber z (stack object).
 	// amd64:`MOVL\t\$3735936685, ""\.x`, `MOVL\t\$3735936685, ""\.y`, -`MOVL\t\$3735936685, ""\.z`
+	// arm64:`MOVW\tR27, ""\.x`, `MOVW\tR27, ""\.y`, -`MOVW\tR27, ""\.z`
 	x, y, z := p1, p2, p3
 	addrTaken(&z)
 	// x is dead at the call (the value of x is loaded before the CALL), y is not
 	// amd64:`MOVL\t\$3735936685, ""\.x`, -`MOVL\t\$3735936685, ""\.y`
+	// arm64:`MOVW\tR27, ""\.x`, -`MOVW\tR27, ""\.y`
 	use(x)
 	// amd64:`MOVL\t\$3735936685, ""\.x`, `MOVL\t\$3735936685, ""\.y`
+	// arm64:`MOVW\tR27, ""\.x`, `MOVW\tR27, ""\.y`
 	use(y)
 }
 
diff --git a/test/codegen/copy.go b/test/codegen/copy.go
index 0cd86d1161a..ea8a01f803f 100644
--- a/test/codegen/copy.go
+++ b/test/codegen/copy.go
@@ -97,6 +97,42 @@ func moveDisjointNoOverlap(a *[256]byte) {
 	copy(a[:], a[128:])
 }
 
+// Check arch-specific memmove lowering. See issue 41662 fot details
+
+func moveArchLowering1(b []byte, x *[1]byte) {
+	_ = b[1]
+	// amd64:-".*memmove"
+	// arm64:-".*memmove"
+	copy(b, x[:])
+}
+
+func moveArchLowering2(b []byte, x *[2]byte) {
+	_ = b[2]
+	// amd64:-".*memmove"
+	// arm64:-".*memmove"
+	copy(b, x[:])
+}
+
+func moveArchLowering4(b []byte, x *[4]byte) {
+	_ = b[4]
+	// amd64:-".*memmove"
+	// arm64:-".*memmove"
+	copy(b, x[:])
+}
+
+func moveArchLowering8(b []byte, x *[8]byte) {
+	_ = b[8]
+	// amd64:-".*memmove"
+	// arm64:-".*memmove"
+	copy(b, x[:])
+}
+
+func moveArchLowering16(b []byte, x *[16]byte) {
+	_ = b[16]
+	// amd64:-".*memmove"
+	copy(b, x[:])
+}
+
 // Check that no branches are generated when the pointers are [not] equal.
 
 func ptrEqual() {
diff --git a/test/complit1.go b/test/complit1.go
index 7c2a4e2996d..8cbcd63ee0d 100644
--- a/test/complit1.go
+++ b/test/complit1.go
@@ -46,20 +46,20 @@ var (
 	_ = &T{0, 0, "", nil}               // ok
 	_ = &T{i: 0, f: 0, s: "", next: {}} // ERROR "missing type in composite literal|omit types within composite literal"
 	_ = &T{0, 0, "", {}}                // ERROR "missing type in composite literal|omit types within composite literal"
-	_ = TP{i: 0, f: 0, s: "", next: {}} // ERROR "invalid composite literal type TP|omit types within composite literal"
+	_ = TP{i: 0, f: 0, s: ""}           // ERROR "invalid composite literal type TP"
 	_ = &Ti{}                           // ERROR "invalid composite literal type Ti|expected.*type for composite literal"
 )
 
 type M map[T]T
 
 var (
-	_ = M{{i:1}: {i:2}}
-	_ = M{T{i:1}: {i:2}}
-	_ = M{{i:1}: T{i:2}}
-	_ = M{T{i:1}: T{i:2}}
+	_ = M{{i: 1}: {i: 2}}
+	_ = M{T{i: 1}: {i: 2}}
+	_ = M{{i: 1}: T{i: 2}}
+	_ = M{T{i: 1}: T{i: 2}}
 )
 
-type S struct { s [1]*M1 }
+type S struct{ s [1]*M1 }
 type M1 map[S]int
-var _ = M1{{s:[1]*M1{&M1{{}:1}}}:2}
 
+var _ = M1{{s: [1]*M1{&M1{{}: 1}}}: 2}
diff --git a/test/ddd1.go b/test/ddd1.go
index ad49b347f49..f7381b7c946 100644
--- a/test/ddd1.go
+++ b/test/ddd1.go
@@ -17,8 +17,8 @@ var (
 	_ = sum(1, 2, 3)
 	_ = sum()
 	_ = sum(1.0, 2.0)
-	_ = sum(1.5)      // ERROR "integer"
-	_ = sum("hello")  // ERROR ".hello. .type untyped string. as type int|incompatible"
+	_ = sum(1.5)      // ERROR "1\.5 .untyped float constant. as int|integer"
+	_ = sum("hello")  // ERROR ".hello. (.untyped string constant. as int|.type untyped string. as type int)|incompatible"
 	_ = sum([]int{1}) // ERROR "\[\]int{...}.*as type int|incompatible"
 )
 
@@ -27,9 +27,9 @@ func tuple() (int, int, int) { return 1, 2, 3 }
 
 var (
 	_ = sum(tuple())
-	_ = sum(tuple()...) // ERROR "multiple-value"
+	_ = sum(tuple()...) // ERROR "\.{3} with 3-valued|multiple-value"
 	_ = sum3(tuple())
-	_ = sum3(tuple()...) // ERROR "multiple-value" ERROR "invalid use of .*[.][.][.]"
+	_ = sum3(tuple()...) // ERROR "\.{3} in call to non-variadic|multiple-value|invalid use of .*[.][.][.]"
 )
 
 type T []T
@@ -60,5 +60,5 @@ func bad(args ...int) {
 	_ = [...]byte("foo") // ERROR "[.][.][.]"
 	_ = [...][...]int{{1,2,3},{4,5,6}}	// ERROR "[.][.][.]"
 
-	Foo(x...) // ERROR "invalid use of .*[.][.][.]"
+	Foo(x...) // ERROR "\.{3} in call to non-variadic|invalid use of .*[.][.][.]"
 }
diff --git a/test/declbad.go b/test/declbad.go
index 728eceb7f1e..b978652a2b1 100644
--- a/test/declbad.go
+++ b/test/declbad.go
@@ -23,13 +23,13 @@ func main() {
 	{
 		// change of type for f
 		i, f, s := f3()
-		f, g, t := f3() // ERROR "redeclared|cannot assign|incompatible"
+		f, g, t := f3() // ERROR "redeclared|cannot assign|incompatible|cannot use"
 		_, _, _, _, _ = i, f, s, g, t
 	}
 	{
 		// change of type for i
 		i, f, s := f3()
-		j, i, t := f3() // ERROR "redeclared|cannot assign|incompatible"
+		j, i, t := f3() // ERROR "redeclared|cannot assign|incompatible|cannot use"
 		_, _, _, _, _ = i, f, s, j, t
 	}
 	{
diff --git a/test/devirt.go b/test/devirt.go
index e0149d82292..d5c815222e4 100644
--- a/test/devirt.go
+++ b/test/devirt.go
@@ -31,9 +31,8 @@ func main() {
 		panic("not 3")
 	}
 
-	// Can't do types that aren't "direct" interfaces (yet).
 	r = indirectiface{3, 4, 5}
-	if r.Value() != 12 {
+	if r.Value() != 12 { // ERROR "de-virtualizing call$"
 		panic("not 12")
 	}
 }
diff --git a/test/escape2.go b/test/escape2.go
index b9b723d8666..e3e5904cde5 100644
--- a/test/escape2.go
+++ b/test/escape2.go
@@ -59,7 +59,7 @@ func foo8(xx, yy *int) int { // ERROR "xx does not escape$" "yy does not escape$
 	return *xx
 }
 
-func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2 level=0$" "leaking param: yy to result ~r2 level=0$"
+func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r0 level=0$" "leaking param: yy to result ~r0 level=0$"
 	xx = yy
 	return xx
 }
@@ -343,11 +343,11 @@ func indaddr1(x int) *int { // ERROR "moved to heap: x$"
 	return &x
 }
 
-func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return *&x
 }
 
-func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return *(**int)(unsafe.Pointer(&x))
 }
 
@@ -374,11 +374,11 @@ func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: f$"
 	return (*uint64)(unsafe.Pointer(&f))
 }
 
-func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1 level=0$"
+func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r0 level=0$"
 	return (*uint64)(unsafe.Pointer(f))
 }
 
-func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	switch val := i.(type) {
 	case *int:
 		return val
@@ -389,7 +389,7 @@ func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level
 	return nil
 }
 
-func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	switch j := i; *j + 110 {
 	case 12:
 		return j
@@ -401,7 +401,7 @@ func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
 }
 
 // assigning to an array element is like assigning to the array
-func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func foo60(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	var a [12]*int
 	a[0] = i
 	return a[1]
@@ -414,7 +414,7 @@ func foo60a(i *int) *int { // ERROR "i does not escape$"
 }
 
 // assigning to a struct field  is like assigning to the struct
-func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func foo61(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	type S struct {
 		a, b *int
 	}
@@ -611,11 +611,11 @@ func foo74c() {
 	}
 }
 
-func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2 level=0$" "x does not escape$"
+func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r0 level=0$" "x does not escape$"
 	return y
 }
 
-func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2 level=0$" "y does not escape$"
+func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r0 level=0$" "y does not escape$"
 	return &x[0]
 }
 
@@ -667,13 +667,13 @@ func foo76e() {
 func foo76f() {
 	for {
 		// TODO: This one really only escapes its scope, but we don't distinguish yet.
-		defer myprint(nil, 1, 2, 3) // ERROR "... argument escapes to heap$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
+		defer myprint(nil, 1, 2, 3) // ERROR "... argument does not escape$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
 	}
 }
 
 func foo76g() {
 	for {
-		defer myprint1(nil, 1, 2, 3) // ERROR "... argument escapes to heap$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
+		defer myprint1(nil, 1, 2, 3) // ERROR "... argument does not escape$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
 	}
 }
 
@@ -770,7 +770,7 @@ func foo91(x *int) map[*int]*int { // ERROR "leaking param: x$"
 	return map[*int]*int{x: nil} // ERROR "map\[\*int\]\*int{...} escapes to heap$"
 }
 
-func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return [2]*int{x, nil}
 }
 
@@ -783,7 +783,7 @@ func foo93(c chan *int) *int { // ERROR "c does not escape$"
 }
 
 // does not leak m
-func foo94(m map[*int]*int, b bool) *int { // ERROR "leaking param: m to result ~r2 level=1"
+func foo94(m map[*int]*int, b bool) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	for k, v := range m {
 		if b {
 			return k
@@ -799,12 +799,12 @@ func foo95(m map[*int]*int, x *int) { // ERROR "m does not escape$" "leaking par
 }
 
 // does not leak m but does leak content
-func foo96(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
+func foo96(m []*int) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	return m[0]
 }
 
 // does leak m
-func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r0 level=0$"
 	return m[0]
 }
 
@@ -814,12 +814,12 @@ func foo98(m map[int]*int) *int { // ERROR "m does not escape$"
 }
 
 // does leak m
-func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r0 level=0$"
 	return m[:]
 }
 
 // does not leak m
-func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
+func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	for _, v := range m {
 		return v
 	}
@@ -827,7 +827,7 @@ func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
 }
 
 // does leak m
-func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r0 level=0$"
 	for _, v := range m {
 		return v
 	}
@@ -890,27 +890,27 @@ func foo110(x *int) *int { // ERROR "leaking param: x$"
 	return m[nil]
 }
 
-func foo111(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0"
+func foo111(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0"
 	m := []*int{x} // ERROR "\[\]\*int{...} does not escape$"
 	return m[0]
 }
 
-func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo112(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := [1]*int{x}
 	return m[0]
 }
 
-func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo113(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := Bar{ii: x}
 	return m.ii
 }
 
-func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo114(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := &Bar{ii: x} // ERROR "&Bar{...} does not escape$"
 	return m.ii
 }
 
-func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo115(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x)) + 1))
 }
 
@@ -1148,16 +1148,16 @@ L100:
 
 func foo121() {
 	for i := 0; i < 10; i++ {
-		defer myprint(nil, i) // ERROR "... argument escapes to heap$" "i escapes to heap$"
-		go myprint(nil, i)    // ERROR "... argument escapes to heap$" "i escapes to heap$"
+		defer myprint(nil, i) // ERROR "... argument does not escape$" "i escapes to heap$"
+		go myprint(nil, i)    // ERROR "... argument does not escape$" "i escapes to heap$"
 	}
 }
 
 // same as foo121 but check across import
 func foo121b() {
 	for i := 0; i < 10; i++ {
-		defer fmt.Printf("%d", i) // ERROR "... argument escapes to heap$" "i escapes to heap$"
-		go fmt.Printf("%d", i)    // ERROR "... argument escapes to heap$" "i escapes to heap$"
+		defer fmt.Printf("%d", i) // ERROR "... argument does not escape$" "i escapes to heap$"
+		go fmt.Printf("%d", i)    // ERROR "... argument does not escape$" "i escapes to heap$"
 	}
 }
 
diff --git a/test/escape2n.go b/test/escape2n.go
index 7c8208aa73c..57cc1a01639 100644
--- a/test/escape2n.go
+++ b/test/escape2n.go
@@ -59,7 +59,7 @@ func foo8(xx, yy *int) int { // ERROR "xx does not escape$" "yy does not escape$
 	return *xx
 }
 
-func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2 level=0$" "leaking param: yy to result ~r2 level=0$"
+func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r0 level=0$" "leaking param: yy to result ~r0 level=0$"
 	xx = yy
 	return xx
 }
@@ -343,11 +343,11 @@ func indaddr1(x int) *int { // ERROR "moved to heap: x$"
 	return &x
 }
 
-func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return *&x
 }
 
-func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return *(**int)(unsafe.Pointer(&x))
 }
 
@@ -374,11 +374,11 @@ func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: f$"
 	return (*uint64)(unsafe.Pointer(&f))
 }
 
-func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1 level=0$"
+func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r0 level=0$"
 	return (*uint64)(unsafe.Pointer(f))
 }
 
-func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	switch val := i.(type) {
 	case *int:
 		return val
@@ -389,7 +389,7 @@ func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level
 	return nil
 }
 
-func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	switch j := i; *j + 110 {
 	case 12:
 		return j
@@ -401,7 +401,7 @@ func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
 }
 
 // assigning to an array element is like assigning to the array
-func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func foo60(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	var a [12]*int
 	a[0] = i
 	return a[1]
@@ -414,7 +414,7 @@ func foo60a(i *int) *int { // ERROR "i does not escape$"
 }
 
 // assigning to a struct field  is like assigning to the struct
-func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$"
+func foo61(i *int) *int { // ERROR "leaking param: i to result ~r0 level=0$"
 	type S struct {
 		a, b *int
 	}
@@ -611,11 +611,11 @@ func foo74c() {
 	}
 }
 
-func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2 level=0$" "x does not escape$"
+func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r0 level=0$" "x does not escape$"
 	return y
 }
 
-func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2 level=0$" "y does not escape$"
+func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r0 level=0$" "y does not escape$"
 	return &x[0]
 }
 
@@ -667,13 +667,13 @@ func foo76e() {
 func foo76f() {
 	for {
 		// TODO: This one really only escapes its scope, but we don't distinguish yet.
-		defer myprint(nil, 1, 2, 3) // ERROR "... argument escapes to heap$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
+		defer myprint(nil, 1, 2, 3) // ERROR "... argument does not escape$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
 	}
 }
 
 func foo76g() {
 	for {
-		defer myprint1(nil, 1, 2, 3) // ERROR "... argument escapes to heap$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
+		defer myprint1(nil, 1, 2, 3) // ERROR "... argument does not escape$" "1 escapes to heap$" "2 escapes to heap$" "3 escapes to heap$"
 	}
 }
 
@@ -770,7 +770,7 @@ func foo91(x *int) map[*int]*int { // ERROR "leaking param: x$"
 	return map[*int]*int{x: nil} // ERROR "map\[\*int\]\*int{...} escapes to heap$"
 }
 
-func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return [2]*int{x, nil}
 }
 
@@ -783,7 +783,7 @@ func foo93(c chan *int) *int { // ERROR "c does not escape$"
 }
 
 // does not leak m
-func foo94(m map[*int]*int, b bool) *int { // ERROR "leaking param: m to result ~r2 level=1"
+func foo94(m map[*int]*int, b bool) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	for k, v := range m {
 		if b {
 			return k
@@ -799,12 +799,12 @@ func foo95(m map[*int]*int, x *int) { // ERROR "m does not escape$" "leaking par
 }
 
 // does not leak m but does leak content
-func foo96(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
+func foo96(m []*int) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	return m[0]
 }
 
 // does leak m
-func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r0 level=0$"
 	return m[0]
 }
 
@@ -814,12 +814,12 @@ func foo98(m map[int]*int) *int { // ERROR "m does not escape$"
 }
 
 // does leak m
-func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r0 level=0$"
 	return m[:]
 }
 
 // does not leak m
-func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
+func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r0 level=1"
 	for _, v := range m {
 		return v
 	}
@@ -827,7 +827,7 @@ func foo100(m []*int) *int { // ERROR "leaking param: m to result ~r1 level=1"
 }
 
 // does leak m
-func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$"
+func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r0 level=0$"
 	for _, v := range m {
 		return v
 	}
@@ -890,27 +890,27 @@ func foo110(x *int) *int { // ERROR "leaking param: x$"
 	return m[nil]
 }
 
-func foo111(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0"
+func foo111(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0"
 	m := []*int{x} // ERROR "\[\]\*int{...} does not escape$"
 	return m[0]
 }
 
-func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo112(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := [1]*int{x}
 	return m[0]
 }
 
-func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo113(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := Bar{ii: x}
 	return m.ii
 }
 
-func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo114(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	m := &Bar{ii: x} // ERROR "&Bar{...} does not escape$"
 	return m.ii
 }
 
-func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo115(x *int) *int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x)) + 1))
 }
 
@@ -1148,16 +1148,16 @@ L100:
 
 func foo121() {
 	for i := 0; i < 10; i++ {
-		defer myprint(nil, i) // ERROR "... argument escapes to heap$" "i escapes to heap$"
-		go myprint(nil, i)    // ERROR "... argument escapes to heap$" "i escapes to heap$"
+		defer myprint(nil, i) // ERROR "... argument does not escape$" "i escapes to heap$"
+		go myprint(nil, i)    // ERROR "... argument does not escape$" "i escapes to heap$"
 	}
 }
 
 // same as foo121 but check across import
 func foo121b() {
 	for i := 0; i < 10; i++ {
-		defer fmt.Printf("%d", i) // ERROR "... argument escapes to heap$" "i escapes to heap$"
-		go fmt.Printf("%d", i)    // ERROR "... argument escapes to heap$" "i escapes to heap$"
+		defer fmt.Printf("%d", i) // ERROR "... argument does not escape$" "i escapes to heap$"
+		go fmt.Printf("%d", i)    // ERROR "... argument does not escape$" "i escapes to heap$"
 	}
 }
 
diff --git a/test/escape5.go b/test/escape5.go
index 82be2c38e79..089130dad5c 100644
--- a/test/escape5.go
+++ b/test/escape5.go
@@ -22,19 +22,19 @@ func leaktoret(p *int) *int { // ERROR "leaking param: p to result"
 	return p
 }
 
-func leaktoret2(p *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: p to result ~r2"
+func leaktoret2(p *int) (*int, *int) { // ERROR "leaking param: p to result ~r0" "leaking param: p to result ~r1"
 	return p, p
 }
 
-func leaktoret22(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r2" "leaking param: q to result ~r3"
+func leaktoret22(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r0" "leaking param: q to result ~r1"
 	return p, q
 }
 
-func leaktoret22b(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r3" "leaking param: q to result ~r2"
+func leaktoret22b(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: q to result ~r0"
 	return leaktoret22(q, p)
 }
 
-func leaktoret22c(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r3" "leaking param: q to result ~r2"
+func leaktoret22c(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: q to result ~r0"
 	r, s := leaktoret22(q, p)
 	return r, s
 }
@@ -173,15 +173,14 @@ type U int
 func (*U) M()   {}
 func (_ *U) N() {}
 
-func _() {
+func fbad24305a() {
 	var u U
 	u.M()
 	u.N()
 }
 
-func fbad24305() {
-	// BAD u should not be heap allocated
-	var u U // ERROR "moved to heap: u"
+func fbad24305b() {
+	var u U
 	(*U).M(&u)
 	(*U).N(&u)
 }
diff --git a/test/escape_array.go b/test/escape_array.go
index 0d07fd861ff..83062c9436e 100644
--- a/test/escape_array.go
+++ b/test/escape_array.go
@@ -12,15 +12,15 @@ var Ssink *string
 
 type U [2]*string
 
-func bar(a, b *string) U { // ERROR "leaking param: a to result ~r2 level=0$" "leaking param: b to result ~r2 level=0$"
+func bar(a, b *string) U { // ERROR "leaking param: a to result ~r0 level=0$" "leaking param: b to result ~r0 level=0$"
 	return U{a, b}
 }
 
-func foo(x U) U { // ERROR "leaking param: x to result ~r1 level=0$"
+func foo(x U) U { // ERROR "leaking param: x to result ~r0 level=0$"
 	return U{x[1], x[0]}
 }
 
-func bff(a, b *string) U { // ERROR "leaking param: a to result ~r2 level=0$" "leaking param: b to result ~r2 level=0$"
+func bff(a, b *string) U { // ERROR "leaking param: a to result ~r0 level=0$" "leaking param: b to result ~r0 level=0$"
 	return foo(foo(bar(a, b)))
 }
 
@@ -41,27 +41,27 @@ func tbff2() *string {
 	return u[1]
 }
 
-func car(x U) *string { // ERROR "leaking param: x to result ~r1 level=0$"
+func car(x U) *string { // ERROR "leaking param: x to result ~r0 level=0$"
 	return x[0]
 }
 
 // BAD: need fine-grained analysis to track x[0] and x[1] differently.
-func fun(x U, y *string) *string { // ERROR "leaking param: x to result ~r2 level=0$" "leaking param: y to result ~r2 level=0$"
+func fun(x U, y *string) *string { // ERROR "leaking param: x to result ~r0 level=0$" "leaking param: y to result ~r0 level=0$"
 	x[0] = y
 	return x[1]
 }
 
-func fup(x *U, y *string) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param: y$"
+func fup(x *U, y *string) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param: y$"
 	x[0] = y // leaking y to heap is intended
 	return x[1]
 }
 
-func fum(x *U, y **string) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param content: y$"
+func fum(x *U, y **string) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param content: y$"
 	x[0] = *y
 	return x[1]
 }
 
-func fuo(x *U, y *U) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param content: y$"
+func fuo(x *U, y *U) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param content: y$"
 	x[0] = y[0]
 	return x[1]
 }
diff --git a/test/escape_calls.go b/test/escape_calls.go
index 9e1db5426ed..aa7c7f516cf 100644
--- a/test/escape_calls.go
+++ b/test/escape_calls.go
@@ -11,7 +11,7 @@
 
 package foo
 
-func f(buf []byte) []byte { // ERROR "leaking param: buf to result ~r1 level=0$"
+func f(buf []byte) []byte { // ERROR "leaking param: buf to result ~r0 level=0$"
 	return buf
 }
 
diff --git a/test/escape_closure.go b/test/escape_closure.go
index 9152319fe04..bd6c025476e 100644
--- a/test/escape_closure.go
+++ b/test/escape_closure.go
@@ -44,7 +44,7 @@ func ClosureCallArgs3() {
 
 func ClosureCallArgs4() {
 	x := 0
-	_ = func(p *int) *int { // ERROR "leaking param: p to result ~r1" "func literal does not escape"
+	_ = func(p *int) *int { // ERROR "leaking param: p to result ~r0" "func literal does not escape"
 		return p
 	}(&x)
 }
@@ -111,7 +111,7 @@ func ClosureCallArgs11() {
 
 func ClosureCallArgs12() {
 	x := 0
-	defer func(p *int) *int { // ERROR "leaking param: p to result ~r1" "func literal does not escape"
+	defer func(p *int) *int { // ERROR "leaking param: p to result ~r0" "func literal does not escape"
 		return p
 	}(&x)
 }
@@ -126,7 +126,7 @@ func ClosureCallArgs13() {
 func ClosureCallArgs14() {
 	x := 0
 	p := &x
-	_ = func(p **int) *int { // ERROR "leaking param: p to result ~r1 level=1" "func literal does not escape"
+	_ = func(p **int) *int { // ERROR "leaking param: p to result ~r0 level=1" "func literal does not escape"
 		return *p
 	}(&p)
 }
@@ -145,7 +145,7 @@ func ClosureLeak1(s string) string { // ERROR "s does not escape"
 }
 
 // See #14409 -- returning part of captured var leaks it.
-func ClosureLeak1a(a ...string) string { // ERROR "leaking param: a to result ~r1 level=1$"
+func ClosureLeak1a(a ...string) string { // ERROR "leaking param: a to result ~r0 level=1$"
 	return func() string { // ERROR "func literal does not escape"
 		return a[0]
 	}()
diff --git a/test/escape_goto.go b/test/escape_goto.go
index f024a9afe37..90da5a21512 100644
--- a/test/escape_goto.go
+++ b/test/escape_goto.go
@@ -10,7 +10,7 @@ package escape
 
 var x bool
 
-func _() {
+func f1() {
 	var p *int
 loop:
 	if x {
@@ -22,7 +22,7 @@ loop:
 	_ = p
 }
 
-func _() {
+func f2() {
 	var p *int
 	if x {
 	loop:
@@ -33,7 +33,7 @@ func _() {
 	_ = p
 }
 
-func _() {
+func f3() {
 	var p *int
 	if x {
 	loop:
diff --git a/test/escape_param.go b/test/escape_param.go
index dc93f689cf9..b630bae88fc 100644
--- a/test/escape_param.go
+++ b/test/escape_param.go
@@ -16,7 +16,7 @@ func zero() int { return 0 }
 var sink interface{}
 
 // in -> out
-func param0(p *int) *int { // ERROR "leaking param: p to result ~r1"
+func param0(p *int) *int { // ERROR "leaking param: p to result ~r0"
 	return p
 }
 
@@ -31,7 +31,7 @@ func caller0b() {
 }
 
 // in, in -> out, out
-func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r2" "leaking param: p2 to result ~r3"
+func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r0" "leaking param: p2 to result ~r1"
 	return p1, p2
 }
 
@@ -222,7 +222,7 @@ func caller8() {
 }
 
 // *in -> out
-func param9(p ***int) **int { // ERROR "leaking param: p to result ~r1 level=1"
+func param9(p ***int) **int { // ERROR "leaking param: p to result ~r0 level=1"
 	return *p
 }
 
@@ -241,7 +241,7 @@ func caller9b() {
 }
 
 // **in -> out
-func param10(p ***int) *int { // ERROR "leaking param: p to result ~r1 level=2"
+func param10(p ***int) *int { // ERROR "leaking param: p to result ~r0 level=2"
 	return **p
 }
 
@@ -436,6 +436,6 @@ func param14a(x [4]*int) interface{} { // ERROR "leaking param: x$"
 
 // Convert to a direct interface, does not need an allocation.
 // So x only leaks to result.
-func param14b(x *int) interface{} { // ERROR "leaking param: x to result ~r1 level=0"
+func param14b(x *int) interface{} { // ERROR "leaking param: x to result ~r0 level=0"
 	return x
 }
diff --git a/test/escape_runtime_atomic.go b/test/escape_runtime_atomic.go
index 62e8fede278..30d1d0c0c1d 100644
--- a/test/escape_runtime_atomic.go
+++ b/test/escape_runtime_atomic.go
@@ -13,8 +13,8 @@ import (
 	"unsafe"
 )
 
-// BAD: should always be "leaking param: addr to result ~r1 level=1$".
-func Loadp(addr unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr( to result ~r1 level=1)?$"
+// BAD: should always be "leaking param: addr to result ~r0 level=1$".
+func Loadp(addr unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr( to result ~r0 level=1)?$"
 	return atomic.Loadp(addr)
 }
 
diff --git a/test/escape_slice.go b/test/escape_slice.go
index d60414736c3..055b60be417 100644
--- a/test/escape_slice.go
+++ b/test/escape_slice.go
@@ -101,7 +101,7 @@ func slice11() {
 	_ = s
 }
 
-func slice12(x []int) *[1]int { // ERROR "leaking param: x to result ~r1 level=0$"
+func slice12(x []int) *[1]int { // ERROR "leaking param: x to result ~r0 level=0$"
 	return (*[1]int)(x)
 }
 
@@ -110,7 +110,7 @@ func envForDir(dir string) []string { // ERROR "dir does not escape"
 	return mergeEnvLists([]string{"PWD=" + dir}, env) // ERROR ".PWD=. \+ dir escapes to heap" "\[\]string{...} does not escape"
 }
 
-func mergeEnvLists(in, out []string) []string { // ERROR "leaking param content: in" "leaking param content: out" "leaking param: out to result ~r2 level=0"
+func mergeEnvLists(in, out []string) []string { // ERROR "leaking param content: in" "leaking param content: out" "leaking param: out to result ~r0 level=0"
 NextVar:
 	for _, inkv := range in {
 		k := strings.SplitAfterN(inkv, "=", 2)[0]
diff --git a/test/escape_struct_return.go b/test/escape_struct_return.go
index 222ef8bc22a..a42ae1e8c9b 100644
--- a/test/escape_struct_return.go
+++ b/test/escape_struct_return.go
@@ -15,11 +15,11 @@ type U struct {
 	_spp **string
 }
 
-func A(sp *string, spp **string) U { // ERROR "leaking param: sp to result ~r2 level=0$" "leaking param: spp to result ~r2 level=0$"
+func A(sp *string, spp **string) U { // ERROR "leaking param: sp to result ~r0 level=0$" "leaking param: spp to result ~r0 level=0$"
 	return U{sp, spp}
 }
 
-func B(spp **string) U { // ERROR "leaking param: spp to result ~r1 level=0$"
+func B(spp **string) U { // ERROR "leaking param: spp to result ~r0 level=0$"
 	return U{*spp, spp}
 }
 
diff --git a/test/escape_unsafe.go b/test/escape_unsafe.go
index b34beacccb5..cec6674a142 100644
--- a/test/escape_unsafe.go
+++ b/test/escape_unsafe.go
@@ -15,7 +15,7 @@ import (
 
 // (1) Conversion of a *T1 to Pointer to *T2.
 
-func convert(p *float64) *uint64 { // ERROR "leaking param: p to result ~r1 level=0$"
+func convert(p *float64) *uint64 { // ERROR "leaking param: p to result ~r0 level=0$"
 	return (*uint64)(unsafe.Pointer(p))
 }
 
@@ -39,12 +39,12 @@ func arithMask() unsafe.Pointer {
 // (5) Conversion of the result of reflect.Value.Pointer or
 // reflect.Value.UnsafeAddr from uintptr to Pointer.
 
-// BAD: should be "leaking param: p to result ~r1 level=0$"
+// BAD: should be "leaking param: p to result ~r0 level=0$"
 func valuePointer(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
 	return unsafe.Pointer(reflect.ValueOf(p).Pointer())
 }
 
-// BAD: should be "leaking param: p to result ~r1 level=0$"
+// BAD: should be "leaking param: p to result ~r0 level=0$"
 func valueUnsafeAddr(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
 	return unsafe.Pointer(reflect.ValueOf(p).Elem().UnsafeAddr())
 }
@@ -52,11 +52,11 @@ func valueUnsafeAddr(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
 // (6) Conversion of a reflect.SliceHeader or reflect.StringHeader
 // Data field to or from Pointer.
 
-func fromSliceData(s []int) unsafe.Pointer { // ERROR "leaking param: s to result ~r1 level=0$"
+func fromSliceData(s []int) unsafe.Pointer { // ERROR "leaking param: s to result ~r0 level=0$"
 	return unsafe.Pointer((*reflect.SliceHeader)(unsafe.Pointer(&s)).Data)
 }
 
-func fromStringData(s string) unsafe.Pointer { // ERROR "leaking param: s to result ~r1 level=0$"
+func fromStringData(s string) unsafe.Pointer { // ERROR "leaking param: s to result ~r0 level=0$"
 	return unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data)
 }
 
diff --git a/test/fixedbugs/bug195.go b/test/fixedbugs/bug195.go
index 94f61fff7f1..6d8578d6cb0 100644
--- a/test/fixedbugs/bug195.go
+++ b/test/fixedbugs/bug195.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -lang=go1.17
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/bug248.dir/bug2.go b/test/fixedbugs/bug248.dir/bug2.go
index c0fdecfdb7b..92a7974679e 100644
--- a/test/fixedbugs/bug248.dir/bug2.go
+++ b/test/fixedbugs/bug248.dir/bug2.go
@@ -50,8 +50,8 @@ var p0i2 p1.I = t0(0) // ERROR "does not implement|incompatible"
 func foobar() {
 	// check that cannot assign one to the other,
 	// but can convert.
-	v0 = v1 // ERROR "assign"
-	v1 = v0 // ERROR "assign"
+	v0 = v1 // ERROR "assign|cannot use"
+	v1 = v0 // ERROR "assign|cannot use"
 
 	v0 = p0.T(v1)
 	v1 = p1.T(v0)
diff --git a/test/fixedbugs/bug267.go b/test/fixedbugs/bug267.go
index cf8bf841f8b..b61216a9d5a 100644
--- a/test/fixedbugs/bug267.go
+++ b/test/fixedbugs/bug267.go
@@ -10,7 +10,7 @@ type T []int
 
 var a []bool
 
-func _() {
+func f1() {
 	if a[T{42}[0]] {
 	}
 	// if (a[T{42}[0]]) {}  // this compiles
diff --git a/test/fixedbugs/bug345.dir/main.go b/test/fixedbugs/bug345.dir/main.go
index b77a2fad5fb..a53d3e8586e 100644
--- a/test/fixedbugs/bug345.dir/main.go
+++ b/test/fixedbugs/bug345.dir/main.go
@@ -23,7 +23,7 @@ func main() {
 	// main.go:27: cannot use &x (type *"io".SectionReader) as type *"/Users/rsc/g/go/test/fixedbugs/bug345.dir/io".SectionReader in function argument
 
 	var w io.Writer
-	bufio.NewWriter(w) // ERROR "[\w.]+[^.]/io|has incompatible type"
+	bufio.NewWriter(w) // ERROR "[\w.]+[^.]/io|has incompatible type|cannot use"
 	var x goio.SectionReader
-	io.SR(&x) // ERROR "[\w.]+[^.]/io|has incompatible type"
+	io.SR(&x) // ERROR "[\w.]+[^.]/io|has incompatible type|cannot use"
 }
diff --git a/test/fixedbugs/bug460.dir/b.go b/test/fixedbugs/bug460.dir/b.go
index ef646946cf1..5d388fc413f 100644
--- a/test/fixedbugs/bug460.dir/b.go
+++ b/test/fixedbugs/bug460.dir/b.go
@@ -9,9 +9,9 @@ import "./a"
 var x a.Foo
 
 func main() {
-	x.int = 20    // ERROR "unexported field"
-	x.int8 = 20   // ERROR "unexported field"
-	x.error = nil // ERROR "unexported field"
-	x.rune = 'a'  // ERROR "unexported field"
-	x.byte = 20   // ERROR "unexported field"
+	x.int = 20    // ERROR "unexported field|undefined"
+	x.int8 = 20   // ERROR "unexported field|undefined"
+	x.error = nil // ERROR "unexported field|undefined"
+	x.rune = 'a'  // ERROR "unexported field|undefined"
+	x.byte = 20   // ERROR "unexported field|undefined"
 }
diff --git a/test/fixedbugs/bug514.go b/test/fixedbugs/bug514.go
new file mode 100644
index 00000000000..3fb7f32a300
--- /dev/null
+++ b/test/fixedbugs/bug514.go
@@ -0,0 +1,55 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type iface interface {
+	Get() int
+}
+
+//go:notinheap
+type notInHeap struct {
+	i int
+}
+
+type myInt struct {
+	f *notInHeap
+}
+
+func (mi myInt) Get() int {
+	return int(mi.f.i)
+}
+
+type embed struct {
+	*myInt
+}
+
+var val = 1234
+
+var valNotInHeap = notInHeap{val}
+
+func main() {
+	i := val
+	check(i)
+	mi := myInt{f: &valNotInHeap}
+	check(mi.Get())
+	ifv := iface(mi)
+	check(ifv.Get())
+	ifv = iface(&mi)
+	check(ifv.Get())
+	em := embed{&mi}
+	check(em.Get())
+	ifv = em
+	check(ifv.Get())
+	ifv = &em
+	check(ifv.Get())
+}
+
+func check(v int) {
+	if v != val {
+		panic(v)
+	}
+}
diff --git a/test/fixedbugs/issue10441.go b/test/fixedbugs/issue10441.go
index 9bc4948b15b..7cd26d841b6 100644
--- a/test/fixedbugs/issue10441.go
+++ b/test/fixedbugs/issue10441.go
@@ -1,4 +1,4 @@
-// build
+// compile
 
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue10607.go b/test/fixedbugs/issue10607.go
index 448a37dcac2..8a04bc9def7 100644
--- a/test/fixedbugs/issue10607.go
+++ b/test/fixedbugs/issue10607.go
@@ -1,4 +1,4 @@
-// +build linux,!ppc64,!riscv64,gc
+// +build linux,!ppc64,gc
 // run
 
 // Copyright 2015 The Go Authors. All rights reserved.
@@ -8,9 +8,6 @@
 // Test that a -B option is passed through when using both internal
 // and external linking mode.
 
-// TODO(jsing): Re-enable on riscv64 when it has support for external
-// linking - see golang.org/issue/36739
-
 package main
 
 import (
diff --git a/test/fixedbugs/issue10975.go b/test/fixedbugs/issue10975.go
index 89ef23c1a86..876ea58ef97 100644
--- a/test/fixedbugs/issue10975.go
+++ b/test/fixedbugs/issue10975.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -lang=go1.17
 
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue11614.go b/test/fixedbugs/issue11614.go
index de15f9827ff..6ea463b7fe9 100644
--- a/test/fixedbugs/issue11614.go
+++ b/test/fixedbugs/issue11614.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -lang=go1.17
 
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue12006.go b/test/fixedbugs/issue12006.go
index 0a2ef8dad04..e878bc48e24 100644
--- a/test/fixedbugs/issue12006.go
+++ b/test/fixedbugs/issue12006.go
@@ -87,7 +87,7 @@ func TFooI() {
 	FooI(a, b, c) // ERROR "a escapes to heap" "b escapes to heap" "... argument does not escape"
 }
 
-func FooJ(args ...interface{}) *int32 { // ERROR "leaking param: args to result ~r1 level=1"
+func FooJ(args ...interface{}) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
 	for i := 0; i < len(args); i++ {
 		switch x := args[i].(type) {
 		case nil:
@@ -123,7 +123,7 @@ type fakeSlice struct {
 	a *[4]interface{}
 }
 
-func FooK(args fakeSlice) *int32 { // ERROR "leaking param: args to result ~r1 level=1"
+func FooK(args fakeSlice) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
 	for i := 0; i < args.l; i++ {
 		switch x := (*args.a)[i].(type) {
 		case nil:
@@ -148,7 +148,7 @@ func TFooK2() {
 	isink = FooK(fs)
 }
 
-func FooL(args []interface{}) *int32 { // ERROR "leaking param: args to result ~r1 level=1"
+func FooL(args []interface{}) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
 	for i := 0; i < len(args); i++ {
 		switch x := args[i].(type) {
 		case nil:
diff --git a/test/fixedbugs/issue12588.go b/test/fixedbugs/issue12588.go
index 950ef36e206..dc8111198c4 100644
--- a/test/fixedbugs/issue12588.go
+++ b/test/fixedbugs/issue12588.go
@@ -35,7 +35,7 @@ func g(a *A) int { // ERROR "a does not escape"
 	return 0
 }
 
-func h(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1"
+func h(a *B) *uint64 { // ERROR "leaking param: a to result ~r0 level=1"
 	for i, x := range &a.b {
 		if i == 0 {
 			return x
@@ -44,7 +44,7 @@ func h(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1"
 	return nil
 }
 
-func h2(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1"
+func h2(a *B) *uint64 { // ERROR "leaking param: a to result ~r0 level=1"
 	p := &a.b
 	for i, x := range p {
 		if i == 0 {
@@ -55,7 +55,7 @@ func h2(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1"
 }
 
 // Seems like below should be level=1, not 0.
-func k(a B) *uint64 { // ERROR "leaking param: a to result ~r1 level=0"
+func k(a B) *uint64 { // ERROR "leaking param: a to result ~r0 level=0"
 	for i, x := range &a.b {
 		if i == 0 {
 			return x
diff --git a/test/fixedbugs/issue14652.go b/test/fixedbugs/issue14652.go
index d53b4126683..14a223977b4 100644
--- a/test/fixedbugs/issue14652.go
+++ b/test/fixedbugs/issue14652.go
@@ -6,4 +6,4 @@
 
 package p
 
-var x any // ERROR "undefined: any|undefined type .*any.*"
+var x any // ERROR "undefined: any|undefined type .*any.*|cannot use any outside constraint position"
diff --git a/test/fixedbugs/issue14999.go b/test/fixedbugs/issue14999.go
index b648441fc29..a25a50e519a 100644
--- a/test/fixedbugs/issue14999.go
+++ b/test/fixedbugs/issue14999.go
@@ -7,11 +7,11 @@
 package p
 
 func f(x int) func(int) int {
-	return func(y int) int { return x + y } // ERROR "heap-allocated closure, not allowed in runtime"
+	return func(y int) int { return x + y } // ERROR "heap-allocated closure f\.func1, not allowed in runtime"
 }
 
 func g(x int) func(int) int { // ERROR "x escapes to heap, not allowed in runtime"
-	return func(y int) int { // ERROR "heap-allocated closure, not allowed in runtime"
+	return func(y int) int { // ERROR "heap-allocated closure g\.func1, not allowed in runtime"
 		x += y
 		return x + y
 	}
diff --git a/test/fixedbugs/issue20250.go b/test/fixedbugs/issue20250.go
index 1a513bea56d..aed7b25d1bf 100644
--- a/test/fixedbugs/issue20250.go
+++ b/test/fixedbugs/issue20250.go
@@ -17,7 +17,7 @@ type T struct {
 func f(a T) { // ERROR "live at entry to f: a"
 	var e interface{} // ERROR "stack object e interface \{\}$"
 	func() {          // ERROR "live at entry to f.func1: a &e"
-		e = a.s // ERROR "live at call to convT2E: &e" "stack object a T$"
+		e = a.s // ERROR "live at call to convT: &e" "stack object a T$"
 	}()
 	// Before the fix, both a and e were live at the previous line.
 	_ = e
diff --git a/test/fixedbugs/issue22076.go b/test/fixedbugs/issue22076.go
index 5d628b96bd3..b383a674e2f 100644
--- a/test/fixedbugs/issue22076.go
+++ b/test/fixedbugs/issue22076.go
@@ -13,12 +13,12 @@ import . "bytes"
 
 var _ Reader // use "bytes" import
 
-func _() {
+func f1() {
 	Buffer := 0
 	_ = Buffer
 }
 
-func _() {
+func f2() {
 	for Buffer := range []int{} {
 		_ = Buffer
 	}
diff --git a/test/fixedbugs/issue24651a.go b/test/fixedbugs/issue24651a.go
index 6c7bf309087..1bfe8ac1ce8 100644
--- a/test/fixedbugs/issue24651a.go
+++ b/test/fixedbugs/issue24651a.go
@@ -21,5 +21,5 @@ var x = 5
 //go:noinline Provide a clean, constant reason for not inlining main
 func main() { // ERROR "cannot inline main: marked go:noinline$"
 	println("Foo(", x, ")=", Foo(x))
-	println("Bar(", x, ")=", Bar(x)) // ERROR "inlining call to Bar func\(int\) int { return x \* \(x \+ 1\) \* \(x \+ 2\) }$"
+	println("Bar(", x, ")=", Bar(x)) // ERROR "inlining call to Bar"
 }
diff --git a/test/fixedbugs/issue24651b.go b/test/fixedbugs/issue24651b.go
index aa88a6787b9..2af54fc4b53 100644
--- a/test/fixedbugs/issue24651b.go
+++ b/test/fixedbugs/issue24651b.go
@@ -19,6 +19,6 @@ var x = 5
 
 //go:noinline Provide a clean, constant reason for not inlining main
 func main() { // ERROR "cannot inline main: marked go:noinline$"
-	println("Foo(", x, ")=", Foo(x)) // ERROR "inlining call to Foo func\(int\) int { return x \* \(x \+ 1\) \* \(x \+ 2\) }$"
-	println("Bar(", x, ")=", Bar(x)) // ERROR "inlining call to Bar func\(int\) int { return x \* \(x \+ 1\) \* \(x \+ 2\) }$"
+	println("Foo(", x, ")=", Foo(x)) // ERROR "inlining call to Foo"
+	println("Bar(", x, ")=", Bar(x)) // ERROR "inlining call to Bar"
 }
diff --git a/test/fixedbugs/issue26163.go b/test/fixedbugs/issue26163.go
index d141a2797d6..3f3d77859de 100644
--- a/test/fixedbugs/issue26163.go
+++ b/test/fixedbugs/issue26163.go
@@ -1,4 +1,4 @@
-// compile -N -d=softfloat -goexperiment noregabiargs
+// compile -N -d=softfloat
 
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue27557.go b/test/fixedbugs/issue27557.go
index e35ab5a1690..f609b27faa5 100644
--- a/test/fixedbugs/issue27557.go
+++ b/test/fixedbugs/issue27557.go
@@ -8,19 +8,19 @@ package p
 
 var sink interface{}
 
-func _() {
+func f1() {
 	var t T
 	f := t.noescape // ERROR "t.noescape does not escape"
 	f()
 }
 
-func _() {
+func f2() {
 	var t T       // ERROR "moved to heap"
 	f := t.escape // ERROR "t.escape does not escape"
 	f()
 }
 
-func _() {
+func f3() {
 	var t T        // ERROR "moved to heap"
 	f := t.returns // ERROR "t.returns does not escape"
 	sink = f()
diff --git a/test/fixedbugs/issue28688.go b/test/fixedbugs/issue28688.go
index 8ef0802812c..0d2000e1498 100644
--- a/test/fixedbugs/issue28688.go
+++ b/test/fixedbugs/issue28688.go
@@ -1,4 +1,4 @@
-// run -gcflags=-d=softfloat -goexperiment noregabiargs
+// run -gcflags=-d=softfloat
 
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue30862.dir/a.go b/test/fixedbugs/issue30862.dir/a/a.go
similarity index 100%
rename from test/fixedbugs/issue30862.dir/a.go
rename to test/fixedbugs/issue30862.dir/a/a.go
diff --git a/test/fixedbugs/issue30862.dir/b.go b/test/fixedbugs/issue30862.dir/b/b.go
similarity index 95%
rename from test/fixedbugs/issue30862.dir/b.go
rename to test/fixedbugs/issue30862.dir/b/b.go
index 3e501bb8dcb..230221d5036 100644
--- a/test/fixedbugs/issue30862.dir/b.go
+++ b/test/fixedbugs/issue30862.dir/b/b.go
@@ -4,7 +4,7 @@
 
 package b
 
-import "./a"
+import "issue30862.dir/a"
 
 type EmbedImported struct {
 	a.NoitfStruct
diff --git a/test/fixedbugs/issue30862.dir/main.go b/test/fixedbugs/issue30862.dir/main.go
index 80db0e13a84..1489c5a3425 100644
--- a/test/fixedbugs/issue30862.dir/main.go
+++ b/test/fixedbugs/issue30862.dir/main.go
@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"os"
 
-	"./b"
+	"issue30862.dir/b"
 )
 
 // Test case for issue 30862.
diff --git a/test/fixedbugs/issue30862.go b/test/fixedbugs/issue30862.go
index ba122cc3c8b..acac71e2cca 100644
--- a/test/fixedbugs/issue30862.go
+++ b/test/fixedbugs/issue30862.go
@@ -1,4 +1,4 @@
-// rundir
+// runindir -goexperiment fieldtrack
 
 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -9,6 +9,4 @@
 // is set when building it, whereas gccgo has field tracking
 // enabled by default (hence the build tag below).
 
-// +build gccgo
-
 package ignored
diff --git a/test/fixedbugs/issue30898.go b/test/fixedbugs/issue30898.go
index b6376d3f9e7..c7f6f2d3712 100644
--- a/test/fixedbugs/issue30898.go
+++ b/test/fixedbugs/issue30898.go
@@ -15,5 +15,5 @@ func debugf(format string, args ...interface{}) { // ERROR "can inline debugf" "
 
 func bar() { // ERROR "can inline bar"
 	value := 10
-	debugf("value is %d", value) // ERROR "inlining call to debugf" "value does not escape" "\[\]interface {}{...} does not escape"
+	debugf("value is %d", value) // ERROR "inlining call to debugf" "value does not escape" "\.\.\. argument does not escape"
 }
diff --git a/test/fixedbugs/issue31573.go b/test/fixedbugs/issue31573.go
index 005910e00d1..eaab5634316 100644
--- a/test/fixedbugs/issue31573.go
+++ b/test/fixedbugs/issue31573.go
@@ -19,31 +19,31 @@ func g() {
 	defer f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} does not escape$" "new\(int\) does not escape$"
 
 	go f()
-	go f(new(int))           // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
-	go f(new(int), new(int)) // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
+	go f(new(int))           // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
+	go f(new(int), new(int)) // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
 
 	go f(nil...)
-	go f([]*int{}...)                   // ERROR "\[\]\*int{} escapes to heap$"
-	go f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
-	go f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
+	go f([]*int{}...)                   // ERROR "\[\]\*int{} does not escape$"
+	go f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
+	go f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
 
 	for {
 		defer f()
-		defer f(new(int))           // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
-		defer f(new(int), new(int)) // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
+		defer f(new(int))           // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
+		defer f(new(int), new(int)) // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
 
 		defer f(nil...)
-		defer f([]*int{}...)                   // ERROR "\[\]\*int{} escapes to heap$"
-		defer f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
-		defer f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
+		defer f([]*int{}...)                   // ERROR "\[\]\*int{} does not escape$"
+		defer f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
+		defer f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
 
 		go f()
-		go f(new(int))           // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
-		go f(new(int), new(int)) // ERROR "... argument escapes to heap$" "new\(int\) escapes to heap$"
+		go f(new(int))           // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
+		go f(new(int), new(int)) // ERROR "... argument does not escape$" "new\(int\) escapes to heap$"
 
 		go f(nil...)
-		go f([]*int{}...)                   // ERROR "\[\]\*int{} escapes to heap$"
-		go f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
-		go f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} escapes to heap$" "new\(int\) escapes to heap$"
+		go f([]*int{}...)                   // ERROR "\[\]\*int{} does not escape$"
+		go f([]*int{new(int)}...)           // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
+		go f([]*int{new(int), new(int)}...) // ERROR "\[\]\*int{...} does not escape$" "new\(int\) escapes to heap$"
 	}
 }
diff --git a/test/fixedbugs/issue41500.go b/test/fixedbugs/issue41500.go
index 3ec23a0dfe0..b0ae7cfd59f 100644
--- a/test/fixedbugs/issue41500.go
+++ b/test/fixedbugs/issue41500.go
@@ -13,8 +13,8 @@ type s struct {
 func f() {
 	var x *s
 
-	_ = x == nil || len(x.slice) // ERROR "invalid operation: .+ \(operator \|\| not defined on int\)|incompatible types|cannot convert"
-	_ = len(x.slice) || x == nil // ERROR "invalid operation: .+ \(operator \|\| not defined on int\)|incompatible types|cannot convert"
-	_ = x == nil && len(x.slice) // ERROR "invalid operation: .+ \(operator && not defined on int\)|incompatible types|cannot convert"
-	_ = len(x.slice) && x == nil // ERROR "invalid operation: .+ \(operator && not defined on int\)|incompatible types|cannot convert"
+	_ = x == nil || len(x.slice) // ERROR "invalid operation: .+ \(operator \|\| not defined on int\)|incompatible types|mismatched types untyped bool and int"
+	_ = len(x.slice) || x == nil // ERROR "invalid operation: .+ \(operator \|\| not defined on int\)|incompatible types|mismatched types int and untyped bool"
+	_ = x == nil && len(x.slice) // ERROR "invalid operation: .+ \(operator && not defined on int\)|incompatible types|mismatched types untyped bool and int"
+	_ = len(x.slice) && x == nil // ERROR "invalid operation: .+ \(operator && not defined on int\)|incompatible types|mismatched types int and untyped bool"
 }
diff --git a/test/fixedbugs/issue42284.dir/a.go b/test/fixedbugs/issue42284.dir/a.go
index ffe9310be35..f7fd80bd207 100644
--- a/test/fixedbugs/issue42284.dir/a.go
+++ b/test/fixedbugs/issue42284.dir/a.go
@@ -13,7 +13,7 @@ func E() I { // ERROR "can inline E"
 	return T(0) // ERROR "T\(0\) escapes to heap"
 }
 
-func F(i I) I { // ERROR "can inline F" "leaking param: i to result ~r1 level=0"
+func F(i I) I { // ERROR "can inline F" "leaking param: i to result ~r0 level=0"
 	i = nil
 	return i
 }
diff --git a/test/fixedbugs/issue43762.go b/test/fixedbugs/issue43762.go
index 9f7682ad6ac..bf950c8f524 100644
--- a/test/fixedbugs/issue43762.go
+++ b/test/fixedbugs/issue43762.go
@@ -6,6 +6,6 @@
 
 package p
 
-var _ = true == '\\' // ERROR "invalid operation: true == '\\\\'|cannot convert true"
-var _ = true == '\'' // ERROR "invalid operation: true == '\\''|cannot convert true"
-var _ = true == '\n' // ERROR "invalid operation: true == '\\n'|cannot convert true"
+var _ = true == '\\' // ERROR "invalid operation: (cannot compare true)|(true) == '\\\\' \(mismatched types untyped bool and untyped rune\)"
+var _ = true == '\'' // ERROR "invalid operation: (cannot compare true)|(true) == '\\'' \(mismatched types untyped bool and untyped rune\)"
+var _ = true == '\n' // ERROR "invalid operation: (cannot compare true)|(true) == '\\n' \(mismatched types untyped bool and untyped rune\)"
diff --git a/test/fixedbugs/issue44432.go b/test/fixedbugs/issue44432.go
index c5fb67e0d78..eec53f30008 100644
--- a/test/fixedbugs/issue44432.go
+++ b/test/fixedbugs/issue44432.go
@@ -8,6 +8,6 @@ package p
 
 var m = map[string]int{
 	"a": 1,
-	1:   1, // ERROR "cannot use 1.*as type string in map key"
-	2:   2, // ERROR "cannot use 2.*as type string in map key"
+	1:   1, // ERROR "cannot use 1.*as.*string.*in map"
+	2:   2, // ERROR "cannot use 2.*as.*string.*in map"
 }
diff --git a/test/fixedbugs/issue45258.go b/test/fixedbugs/issue45258.go
index f4d6fccf17d..b026c0c8f53 100644
--- a/test/fixedbugs/issue45258.go
+++ b/test/fixedbugs/issue45258.go
@@ -22,7 +22,7 @@ func (r *impl) Foo() Barer {
 
 func (r *impl) Bar() {}
 
-func _() {
+func f1() {
 	var r Fooer = &impl{}
 	r.Foo().Bar()
 }
diff --git a/test/fixedbugs/issue46234.go b/test/fixedbugs/issue46234.go
new file mode 100644
index 00000000000..8e7eb8bf8d2
--- /dev/null
+++ b/test/fixedbugs/issue46234.go
@@ -0,0 +1,103 @@
+// buildrun -t 30
+
+// +build !js
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Ensure that runtime traceback does not infinite loop for
+// the testcase below.
+
+package main
+
+import (
+	"bytes"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+const prog = `
+
+package main
+
+import "context"
+
+var gpi *int
+
+type nAO struct {
+	eE bool
+}
+
+type NAO func(*nAO)
+
+func WEA() NAO {
+	return func(o *nAO) { o.eE = true }
+}
+
+type R struct {
+	cM *CM
+}
+
+type CM int
+
+type A string
+
+func (m *CM) NewA(ctx context.Context, cN string, nn *nAO, opts ...NAO) (*A, error) {
+	for _, o := range opts {
+		o(nn)
+	}
+	s := A("foo")
+	return &s, nil
+}
+
+func (r *R) CA(ctx context.Context, cN string, nn *nAO) (*int, error) {
+	cA, err := r.cM.NewA(ctx, cN, nn, WEA(), WEA())
+	if err == nil {
+		return nil, err
+	}
+	println(cA)
+	x := int(42)
+	return &x, nil
+}
+
+func main() {
+	c := CM(1)
+	r := R{cM: &c}
+	var ctx context.Context
+	nnr := nAO{}
+	pi, err := r.CA(ctx, "foo", nil)
+	if err != nil {
+		panic("bad")
+	}
+	println(nnr.eE)
+	gpi = pi
+}
+`
+
+func main() {
+	dir, err := ioutil.TempDir("", "46234")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	file := filepath.Join(dir, "main.go")
+	if err := ioutil.WriteFile(file, []byte(prog), 0655); err != nil {
+		log.Fatalf("Write error %v", err)
+	}
+
+	cmd := exec.Command("go", "run", file)
+	output, err := cmd.CombinedOutput()
+	if err == nil {
+		log.Fatalf("Passed, expected an error")
+	}
+
+	want := []byte("nil pointer dereference")
+	if !bytes.Contains(output, want) {
+		log.Fatalf("Unmatched error message %q:\nin\n%s\nError: %v", want, output, err)
+	}
+}
diff --git a/test/fixedbugs/issue46304.go b/test/fixedbugs/issue46304.go
new file mode 100644
index 00000000000..b8ecfc93a59
--- /dev/null
+++ b/test/fixedbugs/issue46304.go
@@ -0,0 +1,76 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This testcase caused a crash when the register ABI was in effect,
+// on amd64 (problem with register allocation).
+
+package main
+
+type Op struct {
+	tag   string
+	_x    []string
+	_q    [20]uint64
+	plist []P
+}
+
+type P struct {
+	tag string
+	_x  [10]uint64
+	b   bool
+}
+
+type M int
+
+//go:noinline
+func (w *M) walkP(p *P) *P {
+	np := &P{}
+	*np = *p
+	np.tag += "new"
+	return np
+}
+
+func (w *M) walkOp(op *Op) *Op {
+	if op == nil {
+		return nil
+	}
+
+	orig := op
+	cloned := false
+	clone := func() {
+		if !cloned {
+			cloned = true
+			op = &Op{}
+			*op = *orig
+		}
+	}
+
+	pCloned := false
+	for i := range op.plist {
+		if s := w.walkP(&op.plist[i]); s != &op.plist[i] {
+			if !pCloned {
+				pCloned = true
+				clone()
+				op.plist = make([]P, len(orig.plist))
+				copy(op.plist, orig.plist)
+			}
+			op.plist[i] = *s
+		}
+	}
+
+	return op
+}
+
+func main() {
+	var ww M
+	w := &ww
+	p1 := P{tag: "a"}
+	p1._x[1] = 9
+	o := Op{tag: "old", plist: []P{p1}}
+	no := w.walkOp(&o)
+	if no.plist[0].tag != "anew" {
+		panic("bad")
+	}
+}
diff --git a/test/fixedbugs/issue46386.go b/test/fixedbugs/issue46386.go
new file mode 100644
index 00000000000..89dea8abf3b
--- /dev/null
+++ b/test/fixedbugs/issue46386.go
@@ -0,0 +1,32 @@
+// compile -p=main
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface {
+	M() interface{}
+}
+
+type S1 struct{}
+
+func (S1) M() interface{} {
+	return nil
+}
+
+type EI interface{}
+
+type S struct{}
+
+func (S) M(as interface{ I }) {}
+
+func f() interface{ EI } {
+	return &S1{}
+}
+
+func main() {
+	var i interface{ I }
+	(&S{}).M(i)
+}
diff --git a/test/fixedbugs/issue46525.go b/test/fixedbugs/issue46525.go
new file mode 100644
index 00000000000..164e1473ce6
--- /dev/null
+++ b/test/fixedbugs/issue46525.go
@@ -0,0 +1,14 @@
+// errorcheck -lang=go1.16
+
+// Copyright 2021 The Go Authors. All rights reserved.  Use of this
+// source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package p
+
+import "unsafe"
+
+func main() {
+	_ = unsafe.Add(unsafe.Pointer(nil), 0) // ERROR "unsafe.Add requires go1.17 or later"
+	_ = unsafe.Slice(new(byte), 1)         // ERROR "unsafe.Slice requires go1.17 or later"
+}
diff --git a/test/fixedbugs/issue46556.go b/test/fixedbugs/issue46556.go
new file mode 100644
index 00000000000..b159f61b0c5
--- /dev/null
+++ b/test/fixedbugs/issue46556.go
@@ -0,0 +1,16 @@
+// compile
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type A = interface{}
+type B interface{}
+
+// Test that embedding both anonymous and defined types is supported.
+type C interface {
+	A
+	B
+}
diff --git a/test/fixedbugs/issue46653.dir/bad/bad.go b/test/fixedbugs/issue46653.dir/bad/bad.go
new file mode 100644
index 00000000000..c1611b8347a
--- /dev/null
+++ b/test/fixedbugs/issue46653.dir/bad/bad.go
@@ -0,0 +1,64 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func Bad() {
+	m := make(map[int64]A)
+	a := m[0]
+	if len(a.B.C1.D2.E2.F1) != 0 ||
+		len(a.B.C1.D2.E2.F2) != 0 ||
+		len(a.B.C1.D2.E2.F3) != 0 ||
+		len(a.B.C1.D2.E2.F4) != 0 ||
+		len(a.B.C1.D2.E2.F5) != 0 ||
+		len(a.B.C1.D2.E2.F6) != 0 ||
+		len(a.B.C1.D2.E2.F7) != 0 ||
+		len(a.B.C1.D2.E2.F8) != 0 ||
+		len(a.B.C1.D2.E2.F9) != 0 ||
+		len(a.B.C1.D2.E2.F10) != 0 ||
+		len(a.B.C1.D2.E2.F11) != 0 ||
+		len(a.B.C1.D2.E2.F16) != 0 {
+		panic("bad")
+	}
+}
+
+type A struct {
+	B
+}
+
+type B struct {
+	C1 C
+	C2 C
+}
+
+type C struct {
+	D1 D
+	D2 D
+}
+
+type D struct {
+	E1 E
+	E2 E
+	E3 E
+	E4 E
+}
+
+type E struct {
+	F1  string
+	F2  string
+	F3  string
+	F4  string
+	F5  string
+	F6  string
+	F7  string
+	F8  string
+	F9  string
+	F10 string
+	F11 string
+	F12 string
+	F13 string
+	F14 string
+	F15 string
+	F16 string
+}
diff --git a/test/fixedbugs/issue46653.dir/main.go b/test/fixedbugs/issue46653.dir/main.go
new file mode 100644
index 00000000000..e2a96e54ec5
--- /dev/null
+++ b/test/fixedbugs/issue46653.dir/main.go
@@ -0,0 +1,27 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	bad "issue46653.dir/bad"
+)
+
+func main() {
+	bad.Bad()
+}
+
+func neverCalled() L {
+	m := make(map[string]L)
+	return m[""]
+}
+
+type L struct {
+	A Data
+	B Data
+}
+
+type Data struct {
+	F1 [22][]string
+}
diff --git a/test/fixedbugs/issue46653.go b/test/fixedbugs/issue46653.go
new file mode 100644
index 00000000000..e6283b1de50
--- /dev/null
+++ b/test/fixedbugs/issue46653.go
@@ -0,0 +1,10 @@
+// runindir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test to verify compiler and linker handling of multiple
+// competing map.zero symbol definitions.
+
+package ignored
diff --git a/test/fixedbugs/issue46720.go b/test/fixedbugs/issue46720.go
new file mode 100644
index 00000000000..3b0151ae84f
--- /dev/null
+++ b/test/fixedbugs/issue46720.go
@@ -0,0 +1,15 @@
+// compile
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func f() {
+	nonce := make([]byte, 24)
+	g((*[24]byte)(nonce))
+}
+
+//go:noinline
+func g(*[24]byte) {}
diff --git a/test/fixedbugs/issue46725.go b/test/fixedbugs/issue46725.go
new file mode 100644
index 00000000000..29799c7d7ee
--- /dev/null
+++ b/test/fixedbugs/issue46725.go
@@ -0,0 +1,48 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "runtime"
+
+type T [4]int
+
+//go:noinline
+func g(x []*T) ([]*T, []*T) { return x, x }
+
+func main() {
+	const Jenny = 8675309
+	s := [10]*T{{Jenny}}
+
+	done := make(chan struct{})
+	runtime.SetFinalizer(s[0], func(p *T) { close(done) })
+
+	var h, _ interface{} = g(s[:])
+
+	if wait(done) {
+		panic("GC'd early")
+	}
+
+	if h.([]*T)[0][0] != Jenny {
+		panic("lost Jenny's number")
+	}
+
+	if !wait(done) {
+		panic("never GC'd")
+	}
+}
+
+func wait(done <-chan struct{}) bool {
+	for i := 0; i < 10; i++ {
+		runtime.GC()
+		select {
+		case <-done:
+			return true
+		default:
+		}
+	}
+	return false
+}
diff --git a/test/fixedbugs/issue46749.go b/test/fixedbugs/issue46749.go
new file mode 100644
index 00000000000..faf1f884a6b
--- /dev/null
+++ b/test/fixedbugs/issue46749.go
@@ -0,0 +1,37 @@
+// errorcheck
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+var s string
+var b bool
+var i int
+var iface interface{}
+
+var (
+	_ = "" + b   // ERROR "invalid operation.*mismatched types.*untyped string and bool"
+	_ = "" + i   // ERROR "invalid operation.*mismatched types.*untyped string and int"
+	_ = "" + nil // ERROR "invalid operation.*mismatched types.*untyped string and nil|(untyped nil)"
+)
+
+var (
+	_ = s + false // ERROR "invalid operation.*mismatched types.*string and untyped bool"
+	_ = s + 1     // ERROR "invalid operation.*mismatched types.*string and untyped int"
+	_ = s + nil   // ERROR "invalid operation.*mismatched types.*string and nil|(untyped nil)"
+)
+
+var (
+	_ = "" + false // ERROR "invalid operation.*mismatched types.*untyped string and untyped bool"
+	_ = "" + 1     // ERROR "invalid operation.*mismatched types.*untyped string and untyped int"
+)
+
+var (
+	_ = b + 1         // ERROR "invalid operation.*mismatched types.*bool and untyped int"
+	_ = i + false     // ERROR "invalid operation.*mismatched types.*int and untyped bool"
+	_ = iface + 1     // ERROR "invalid operation.*mismatched types.*interface *{} and int"
+	_ = iface + 1.0   // ERROR "invalid operation.*mismatched types.*interface *{} and float64"
+	_ = iface + false // ERROR "invalid operation.*mismatched types.*interface *{} and bool"
+)
diff --git a/test/fixedbugs/issue46903.go b/test/fixedbugs/issue46903.go
new file mode 100644
index 00000000000..3237a583d54
--- /dev/null
+++ b/test/fixedbugs/issue46903.go
@@ -0,0 +1,32 @@
+// run
+//go:build goexperiment.unified
+// +build goexperiment.unified
+
+// TODO(mdempsky): Enable test unconditionally. This test should pass
+// for non-unified mode too.
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+//go:notinheap
+type A struct{ B }
+type B struct{ x byte }
+type I interface{ M() *B }
+
+func (p *B) M() *B { return p }
+
+var (
+	a A
+	i I = &a
+)
+
+func main() {
+	got, want := i.M(), &a.B
+	if got != want {
+		println(got, "!=", want)
+		panic("FAIL")
+	}
+}
diff --git a/test/fixedbugs/issue46907.go b/test/fixedbugs/issue46907.go
new file mode 100644
index 00000000000..bd82f4f2b10
--- /dev/null
+++ b/test/fixedbugs/issue46907.go
@@ -0,0 +1,11 @@
+// compile
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func f(b []byte) []byte {
+	return (*[32]byte)(b[:32])[:]
+}
diff --git a/test/fixedbugs/issue46957.go b/test/fixedbugs/issue46957.go
new file mode 100644
index 00000000000..f3ed3c3def0
--- /dev/null
+++ b/test/fixedbugs/issue46957.go
@@ -0,0 +1,13 @@
+// errorcheck
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f(a int, b ...int) {}
+
+func main() {
+	f(nil...) // ERROR "not enough arguments in call to f$"
+}
diff --git a/test/fixedbugs/issue47087.dir/a.go b/test/fixedbugs/issue47087.dir/a.go
new file mode 100644
index 00000000000..6093092acee
--- /dev/null
+++ b/test/fixedbugs/issue47087.dir/a.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func F() interface{} { return struct{ _ []int }{} }
+
+var X = F()
diff --git a/test/fixedbugs/issue47087.dir/b.go b/test/fixedbugs/issue47087.dir/b.go
new file mode 100644
index 00000000000..8f96d25a12b
--- /dev/null
+++ b/test/fixedbugs/issue47087.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+func F() interface{} { return struct{ _ []int }{} }
+
+var X = F()
diff --git a/test/fixedbugs/issue47087.dir/main.go b/test/fixedbugs/issue47087.dir/main.go
new file mode 100644
index 00000000000..ccd0891a61a
--- /dev/null
+++ b/test/fixedbugs/issue47087.dir/main.go
@@ -0,0 +1,19 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"b"
+)
+
+func main() {
+	if a.F() == b.F() {
+		panic("FAIL")
+	}
+	if a.X == b.X {
+		panic("FAIL")
+	}
+}
diff --git a/test/fixedbugs/issue47087.go b/test/fixedbugs/issue47087.go
new file mode 100644
index 00000000000..40df49f83be
--- /dev/null
+++ b/test/fixedbugs/issue47087.go
@@ -0,0 +1,7 @@
+// rundir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/fixedbugs/issue47131.dir/a.go b/test/fixedbugs/issue47131.dir/a.go
new file mode 100644
index 00000000000..6e798d1d0c8
--- /dev/null
+++ b/test/fixedbugs/issue47131.dir/a.go
@@ -0,0 +1,13 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type MyInt int
+
+type MyIntAlias = MyInt
+
+func (mia *MyIntAlias) Get() int {
+	return int(*mia)
+}
diff --git a/test/fixedbugs/issue47131.dir/b.go b/test/fixedbugs/issue47131.dir/b.go
new file mode 100644
index 00000000000..c658127ca9d
--- /dev/null
+++ b/test/fixedbugs/issue47131.dir/b.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+func F2() int {
+	var mia a.MyIntAlias
+	return mia.Get()
+}
diff --git a/test/fixedbugs/issue47131.go b/test/fixedbugs/issue47131.go
new file mode 100644
index 00000000000..b83fbd7af16
--- /dev/null
+++ b/test/fixedbugs/issue47131.go
@@ -0,0 +1,7 @@
+// compiledir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/fixedbugs/issue47185.dir/bad/bad.go b/test/fixedbugs/issue47185.dir/bad/bad.go
new file mode 100644
index 00000000000..1aa4fbb9095
--- /dev/null
+++ b/test/fixedbugs/issue47185.dir/bad/bad.go
@@ -0,0 +1,72 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+// Note that the use of CGO here is solely to trigger external
+// linking, since that is required to trigger that bad behavior
+// in this bug.
+
+// #include 
+import "C"
+
+func Bad() {
+	m := make(map[int64]A)
+	a := m[0]
+	if len(a.B.C1.D2.E2.F1) != 0 ||
+		len(a.B.C1.D2.E2.F2) != 0 ||
+		len(a.B.C1.D2.E2.F3) != 0 ||
+		len(a.B.C1.D2.E2.F4) != 0 ||
+		len(a.B.C1.D2.E2.F5) != 0 ||
+		len(a.B.C1.D2.E2.F6) != 0 ||
+		len(a.B.C1.D2.E2.F7) != 0 ||
+		len(a.B.C1.D2.E2.F8) != 0 ||
+		len(a.B.C1.D2.E2.F9) != 0 ||
+		len(a.B.C1.D2.E2.F10) != 0 ||
+		len(a.B.C1.D2.E2.F11) != 0 ||
+		len(a.B.C1.D2.E2.F16) != 0 {
+		panic("bad")
+	}
+	C.malloc(100)
+}
+
+type A struct {
+	B
+}
+
+type B struct {
+	C1 C
+	C2 C
+}
+
+type C struct {
+	D1 D
+	D2 D
+}
+
+type D struct {
+	E1 E
+	E2 E
+	E3 E
+	E4 E
+}
+
+type E struct {
+	F1  string
+	F2  string
+	F3  string
+	F4  string
+	F5  string
+	F6  string
+	F7  string
+	F8  string
+	F9  string
+	F10 string
+	F11 string
+	F12 string
+	F13 string
+	F14 string
+	F15 string
+	F16 string
+}
diff --git a/test/fixedbugs/issue47185.dir/main.go b/test/fixedbugs/issue47185.dir/main.go
new file mode 100644
index 00000000000..7b46e55d8b5
--- /dev/null
+++ b/test/fixedbugs/issue47185.dir/main.go
@@ -0,0 +1,28 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	bad "issue47185.dir/bad"
+)
+
+func main() {
+	another()
+	bad.Bad()
+}
+
+func another() L {
+	m := make(map[string]L)
+	return m[""]
+}
+
+type L struct {
+	A Data
+	B Data
+}
+
+type Data struct {
+	F1 [22][]string
+}
diff --git a/test/fixedbugs/issue47185.go b/test/fixedbugs/issue47185.go
new file mode 100644
index 00000000000..9c921b86984
--- /dev/null
+++ b/test/fixedbugs/issue47185.go
@@ -0,0 +1,11 @@
+// +build cgo
+// runindir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Another test to verify compiler and linker handling of multiple
+// competing map.zero symbol definitions.
+
+package ignored
diff --git a/test/fixedbugs/issue47201.dir/a.go b/test/fixedbugs/issue47201.dir/a.go
new file mode 100644
index 00000000000..54b70790926
--- /dev/null
+++ b/test/fixedbugs/issue47201.dir/a.go
@@ -0,0 +1,13 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	. "fmt"
+)
+
+func test() {
+	Println("foo")
+}
diff --git a/test/fixedbugs/issue47201.dir/b.go b/test/fixedbugs/issue47201.dir/b.go
new file mode 100644
index 00000000000..5fd0635af2e
--- /dev/null
+++ b/test/fixedbugs/issue47201.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func Println() {} // ERROR "Println redeclared in this block"
+
+func main() {}
diff --git a/test/fixedbugs/issue47201.go b/test/fixedbugs/issue47201.go
new file mode 100644
index 00000000000..e3a470b4195
--- /dev/null
+++ b/test/fixedbugs/issue47201.go
@@ -0,0 +1,7 @@
+// errorcheckdir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/fixedbugs/issue47227.go b/test/fixedbugs/issue47227.go
new file mode 100644
index 00000000000..a14efc9a689
--- /dev/null
+++ b/test/fixedbugs/issue47227.go
@@ -0,0 +1,23 @@
+// run fake-arg-to-force-use-of-go-run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build cgo
+// +build cgo
+
+package main
+
+// void f(int *p) { *p = 0x12345678; }
+import "C"
+
+func main() {
+	var x C.int
+	func() {
+		defer C.f(&x)
+	}()
+	if x != 0x12345678 {
+		panic("FAIL")
+	}
+}
diff --git a/test/fixedbugs/issue47317.dir/a.s b/test/fixedbugs/issue47317.dir/a.s
new file mode 100644
index 00000000000..b969ddb972c
--- /dev/null
+++ b/test/fixedbugs/issue47317.dir/a.s
@@ -0,0 +1,6 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+TEXT	·G(SB),4,$0
+	RET
diff --git a/test/fixedbugs/issue47317.dir/x.go b/test/fixedbugs/issue47317.dir/x.go
new file mode 100644
index 00000000000..83b5542144d
--- /dev/null
+++ b/test/fixedbugs/issue47317.dir/x.go
@@ -0,0 +1,17 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 47317: ICE when calling ABI0 function via func value.
+
+package main
+
+func main() { F() }
+
+func F() interface{} {
+	g := G
+	g(1)
+	return G
+}
+
+func G(x int) [2]int
diff --git a/test/fixedbugs/issue47317.go b/test/fixedbugs/issue47317.go
new file mode 100644
index 00000000000..3548e90d020
--- /dev/null
+++ b/test/fixedbugs/issue47317.go
@@ -0,0 +1,7 @@
+// builddir
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/fixedbugs/issue4909b.go b/test/fixedbugs/issue4909b.go
index 0f594e3db67..7d7922701a2 100644
--- a/test/fixedbugs/issue4909b.go
+++ b/test/fixedbugs/issue4909b.go
@@ -73,7 +73,7 @@ func writeDot(ns ...int) {
 		}
 		fmt.Print(")")
 		if isIndirect {
-			fmt.Print(` // ERROR "indirection"`)
+			fmt.Print(` // ERROR "indirection|embedded via a pointer"`)
 		}
 		fmt.Print("\n")
 	}
diff --git a/test/fixedbugs/issue8042.go b/test/fixedbugs/issue8042.go
index 5639f97bb89..be15ef06cd2 100644
--- a/test/fixedbugs/issue8042.go
+++ b/test/fixedbugs/issue8042.go
@@ -9,7 +9,7 @@
 
 package p
 
-func _() {
+func f1() {
 	goto L1
 	const x = 0
 L1:
@@ -18,7 +18,7 @@ L1:
 L2:
 }
 
-func _() {
+func f2() {
 	{
 		goto L1
 	}
@@ -31,7 +31,7 @@ L1:
 L2:
 }
 
-func _(d int) {
+func f3(d int) {
 	if d > 0 {
 		goto L1
 	} else {
diff --git a/test/fixedbugs/issue8761.go b/test/fixedbugs/issue8761.go
index 7f458f7f033..e5130e1ff5c 100644
--- a/test/fixedbugs/issue8761.go
+++ b/test/fixedbugs/issue8761.go
@@ -10,17 +10,17 @@
 
 package p
 
-func _() {
+func f1() {
 	type C chan int
 	_ = [1][]C{[]C{make(chan int)}}
 }
 
-func _() {
+func f2() {
 	type C interface{}
 	_ = [1][]C{[]C{recover()}}
 }
 
-func _() {
+func f3() {
 	type C *int
 	_ = [1][]C{[]C{new(int)}}
 }
diff --git a/test/inline.go b/test/inline.go
index bc23768d016..a73c0ba7b1d 100644
--- a/test/inline.go
+++ b/test/inline.go
@@ -1,4 +1,4 @@
-// errorcheck -0 -m -d=inlfuncswithclosures=1
+// errorcheckwithauto -0 -m -d=inlfuncswithclosures=1
 
 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -49,7 +49,7 @@ func j(x int) int { // ERROR "can inline j"
 	}
 }
 
-func _() int { // ERROR "can inline _"
+func f2() int { // ERROR "can inline f2"
 	tmp1 := h
 	tmp2 := tmp1
 	return tmp2(0) // ERROR "inlining call to h"
@@ -92,9 +92,9 @@ func o() int {
 	foo := func() int { return 1 } // ERROR "can inline o.func1" "func literal does not escape"
 	func(x int) {                  // ERROR "can inline o.func2"
 		if x > 10 {
-			foo = func() int { return 2 } // ERROR "can inline o.func2"
+			foo = func() int { return 2 } // ERROR "func literal does not escape" "can inline o.func2"
 		}
-	}(11) // ERROR "func literal does not escape" "inlining call to o.func2"
+	}(11) // ERROR "inlining call to o.func2"
 	return foo()
 }
 
@@ -167,8 +167,9 @@ func (T) meth(int, int) {} // ERROR "can inline T.meth"
 
 func k() (T, int, int) { return T{}, 0, 0 } // ERROR "can inline k"
 
-func _() { // ERROR "can inline _"
+func f3() { // ERROR "can inline f3"
 	T.meth(k()) // ERROR "inlining call to k" "inlining call to T.meth"
+	// ERRORAUTO "inlining call to T.meth"
 }
 
 func small1() { // ERROR "can inline small1"
@@ -232,12 +233,13 @@ Loop:
 // Issue #18493 - make sure we can do inlining of functions with a method value
 type T1 struct{}
 
-func (a T1) meth(val int) int { // ERROR "can inline T1.meth" "inlining call to T1.meth"
+func (a T1) meth(val int) int { // ERROR "can inline T1.meth"
 	return val + 5
 }
 
 func getMeth(t1 T1) func(int) int { // ERROR "can inline getMeth"
 	return t1.meth // ERROR "t1.meth escapes to heap"
+	// ERRORAUTO "inlining call to T1.meth"
 }
 
 func ii() { // ERROR "can inline ii"
diff --git a/test/inline_big.go b/test/inline_big.go
index 68e1101d3b0..83672753f78 100644
--- a/test/inline_big.go
+++ b/test/inline_big.go
@@ -1023,7 +1023,7 @@ func f(a []int) int { // ERROR "cannot inline f:.*" "a does not escape"
 	a[997] = 0
 	a[998] = 0
 	a[999] = 0
-	x := small(a)  // ERROR "inlining call to small .*"
+	x := small(a)  // ERROR "inlining call to small"
 	y := medium(a) // The crux of this test: medium is not inlined.
 	return x + y
 }
diff --git a/test/inline_variadic.go b/test/inline_variadic.go
index 687048a1922..49483d77f79 100644
--- a/test/inline_variadic.go
+++ b/test/inline_variadic.go
@@ -14,6 +14,6 @@ func head(xs ...string) string { // ERROR "can inline head" "leaking param: xs t
 }
 
 func f() string { // ERROR "can inline f"
-	x := head("hello", "world") // ERROR "inlining call to head" "\[\]string{...} does not escape"
+	x := head("hello", "world") // ERROR "inlining call to head" "\.\.\. argument does not escape"
 	return x
 }
diff --git a/test/live.go b/test/live.go
index bc7b3849cf3..6130f7f0694 100644
--- a/test/live.go
+++ b/test/live.go
@@ -1,5 +1,5 @@
 // errorcheckwithauto -0 -l -live -wb=0 -d=ssa/insert_resched_checks/off
-// +build !ppc64,!ppc64le,!goexperiment.regabi,!goexperiment.regabidefer
+// +build !ppc64,!ppc64le,!goexperiment.regabiargs
 
 // ppc64 needs a better tighten pass to make f18 pass
 // rescheduling checks need to be turned off because there are some live variables across the inserted check call
@@ -144,8 +144,8 @@ var i9 interface{}
 func f9() bool {
 	g8()
 	x := i9
-	y := interface{}(g18()) // ERROR "live at call to convT2E: x.data$" "live at call to g18: x.data$" "stack object .autotmp_[0-9]+ \[2\]string$"
-	i9 = y                  // make y escape so the line above has to call convT2E
+	y := interface{}(g18()) // ERROR "live at call to convT: x.data$" "live at call to g18: x.data$" "stack object .autotmp_[0-9]+ \[2\]string$"
+	i9 = y                  // make y escape so the line above has to call convT
 	return x != y
 }
 
@@ -424,7 +424,7 @@ func f27defer(b bool) {
 	}
 	defer call27(func() { x++ }) // ERROR "stack object .autotmp_[0-9]+ struct \{"
 	printnl()                    // ERROR "live at call to printnl: .autotmp_[0-9]+ .autotmp_[0-9]+"
-	return                       // ERROR "live at call to call27: .autotmp_[0-9]+"
+	return                       // ERROR "live at indirect call: .autotmp_[0-9]+"
 }
 
 // and newproc (go) escapes to the heap
@@ -432,9 +432,9 @@ func f27defer(b bool) {
 func f27go(b bool) {
 	x := 0
 	if b {
-		go call27(func() { x++ }) // ERROR "live at call to newobject: &x$" "live at call to newproc: &x$"
+		go call27(func() { x++ }) // ERROR "live at call to newobject: &x$" "live at call to newobject: &x .autotmp_[0-9]+$" "live at call to newproc: &x$" // allocate two closures, the func literal, and the wrapper for go
 	}
-	go call27(func() { x++ }) // ERROR "live at call to newobject: &x$"
+	go call27(func() { x++ }) // ERROR "live at call to newobject: &x$" "live at call to newobject: .autotmp_[0-9]+$" // allocate two closures, the func literal, and the wrapper for go
 	printnl()
 }
 
@@ -503,7 +503,7 @@ func f31(b1, b2, b3 bool) {
 		g31(g18()) // ERROR "stack object .autotmp_[0-9]+ \[2\]string$"
 	}
 	if b2 {
-		h31(g18()) // ERROR "live at call to convT2E: .autotmp_[0-9]+$" "live at call to newobject: .autotmp_[0-9]+$"
+		h31(g18()) // ERROR "live at call to convT: .autotmp_[0-9]+$" "live at call to newobject: .autotmp_[0-9]+$"
 	}
 	if b3 {
 		panic(g18())
@@ -688,7 +688,7 @@ type T struct{}
 
 func (*T) Foo(ptr *int) {}
 
-type R struct{ *T } // ERRORAUTO "live at entry to \(\*R\)\.Foo: \.this ptr" "live at entry to R\.Foo: \.this ptr"
+type R struct{ *T }
 
 // issue 18860: output arguments must be live all the time if there is a defer.
 // In particular, at printint r must be live.
diff --git a/test/live_regabi.go b/test/live_regabi.go
index 2b0278ecb83..2883b83baed 100644
--- a/test/live_regabi.go
+++ b/test/live_regabi.go
@@ -1,5 +1,5 @@
 // errorcheckwithauto -0 -l -live -wb=0 -d=ssa/insert_resched_checks/off
-// +build amd64,goexperiment.regabidefer,goexperiment.regabiargs
+// +build amd64,goexperiment.regabiargs
 
 // Copyright 2014 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -139,8 +139,8 @@ var i9 interface{}
 func f9() bool {
 	g8()
 	x := i9
-	y := interface{}(g18()) // ERROR "live at call to convT2E: x.data$" "live at call to g18: x.data$" "stack object .autotmp_[0-9]+ \[2\]string$"
-	i9 = y                  // make y escape so the line above has to call convT2E
+	y := interface{}(g18()) // ERROR "live at call to convT: x.data$" "live at call to g18: x.data$" "stack object .autotmp_[0-9]+ \[2\]string$"
+	i9 = y                  // make y escape so the line above has to call convT
 	return x != y
 }
 
@@ -498,7 +498,7 @@ func f31(b1, b2, b3 bool) {
 		g31(g18()) // ERROR "stack object .autotmp_[0-9]+ \[2\]string$"
 	}
 	if b2 {
-		h31(g18()) // ERROR "live at call to convT2E: .autotmp_[0-9]+$" "live at call to newobject: .autotmp_[0-9]+$"
+		h31(g18()) // ERROR "live at call to convT: .autotmp_[0-9]+$" "live at call to newobject: .autotmp_[0-9]+$"
 	}
 	if b3 {
 		panic(g18())
@@ -683,7 +683,7 @@ type T struct{}
 
 func (*T) Foo(ptr *int) {}
 
-type R struct{ *T } // ERRORAUTO "live at entry to \(\*R\)\.Foo: \.this ptr" "live at entry to R\.Foo: \.this ptr"
+type R struct{ *T }
 
 // issue 18860: output arguments must be live all the time if there is a defer.
 // In particular, at printint r must be live.
diff --git a/test/reflectmethod8.go b/test/reflectmethod8.go
new file mode 100644
index 00000000000..482163bae6f
--- /dev/null
+++ b/test/reflectmethod8.go
@@ -0,0 +1,26 @@
+// compile
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Make sure that the compiler can analyze non-reflect
+// Type.{Method,MethodByName} calls.
+
+package p
+
+type I interface {
+	MethodByName(string)
+	Method(int)
+}
+
+type M struct{}
+
+func (M) MethodByName(string) {}
+func (M) Method(int)          {}
+
+func f() {
+	var m M
+	I.MethodByName(m, "")
+	I.Method(m, 42)
+}
diff --git a/test/run.go b/test/run.go
index 5e60de76248..6296234d565 100644
--- a/test/run.go
+++ b/test/run.go
@@ -9,6 +9,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
@@ -42,11 +43,55 @@ var (
 	linkshared     = flag.Bool("linkshared", false, "")
 	updateErrors   = flag.Bool("update_errors", false, "update error messages in test file based on compiler output")
 	runoutputLimit = flag.Int("l", defaultRunOutputLimit(), "number of parallel runoutput tests to run")
+	force          = flag.Bool("f", false, "ignore expected-failure test lists")
+	generics       = flag.String("G", defaultGLevels, "a comma-separated list of -G compiler flags to test with")
 
 	shard  = flag.Int("shard", 0, "shard index to run. Only applicable if -shards is non-zero.")
 	shards = flag.Int("shards", 0, "number of shards. If 0, all tests are run. This is used by the continuous build.")
 )
 
+type envVars struct {
+	GOOS         string
+	GOARCH       string
+	GOEXPERIMENT string
+	CGO_ENABLED  string
+}
+
+var env = func() (res envVars) {
+	cmd := exec.Command("go", "env", "-json")
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		log.Fatal("StdoutPipe:", err)
+	}
+	if err := cmd.Start(); err != nil {
+		log.Fatal("Start:", err)
+	}
+	if err := json.NewDecoder(stdout).Decode(&res); err != nil {
+		log.Fatal("Decode:", err)
+	}
+	if err := cmd.Wait(); err != nil {
+		log.Fatal("Wait:", err)
+	}
+	return
+}()
+
+var unifiedEnabled, defaultGLevels = func() (bool, string) {
+	// TODO(mdempsky): This will give false negatives if the unified
+	// experiment is enabled by default, but presumably at that point we
+	// won't need to disable tests for it anymore anyway.
+	enabled := strings.Contains(","+env.GOEXPERIMENT+",", ",unified,")
+
+	// Normal test runs should test with both -G=0 and -G=3 for types2
+	// coverage. But the unified experiment always uses types2, so
+	// testing with -G=3 is redundant.
+	glevels := "0,3"
+	if enabled {
+		glevels = "0"
+	}
+
+	return enabled, glevels
+}()
+
 // defaultAllCodeGen returns the default value of the -all_codegen
 // flag. By default, we prefer to be fast (returning false), except on
 // the linux-amd64 builder that's already very fast, so we get more
@@ -56,12 +101,13 @@ func defaultAllCodeGen() bool {
 }
 
 var (
-	goos, goarch string
-	cgoEnabled   bool
+	goos          = env.GOOS
+	goarch        = env.GOARCH
+	cgoEnabled, _ = strconv.ParseBool(env.CGO_ENABLED)
 
 	// dirs are the directories to look for *.go files in.
 	// TODO(bradfitz): just use all directories?
-	dirs = []string{".", "ken", "chan", "interface", "syntax", "dwarf", "fixedbugs", "codegen", "runtime", "abi", "typeparam"}
+	dirs = []string{".", "ken", "chan", "interface", "syntax", "dwarf", "fixedbugs", "codegen", "runtime", "abi", "typeparam", "typeparam/mdempsky"}
 
 	// ratec controls the max number of tests running at a time.
 	ratec chan bool
@@ -82,11 +128,13 @@ const maxTests = 5000
 func main() {
 	flag.Parse()
 
-	goos = getenv("GOOS", runtime.GOOS)
-	goarch = getenv("GOARCH", runtime.GOARCH)
-	cgoEnv, err := exec.Command(goTool(), "env", "CGO_ENABLED").Output()
-	if err == nil {
-		cgoEnabled, _ = strconv.ParseBool(strings.TrimSpace(string(cgoEnv)))
+	var glevels []int
+	for _, s := range strings.Split(*generics, ",") {
+		glevel, err := strconv.Atoi(s)
+		if err != nil {
+			log.Fatalf("invalid -G flag: %v", err)
+		}
+		glevels = append(glevels, glevel)
 	}
 
 	findExecCmd()
@@ -113,11 +161,11 @@ func main() {
 			}
 			if fi, err := os.Stat(arg); err == nil && fi.IsDir() {
 				for _, baseGoFile := range goFiles(arg) {
-					tests = append(tests, startTest(arg, baseGoFile))
+					tests = append(tests, startTests(arg, baseGoFile, glevels)...)
 				}
 			} else if strings.HasSuffix(arg, ".go") {
 				dir, file := filepath.Split(arg)
-				tests = append(tests, startTest(dir, file))
+				tests = append(tests, startTests(dir, file, glevels)...)
 			} else {
 				log.Fatalf("can't yet deal with non-directory and non-go file %q", arg)
 			}
@@ -125,7 +173,7 @@ func main() {
 	} else {
 		for _, dir := range dirs {
 			for _, baseGoFile := range goFiles(dir) {
-				tests = append(tests, startTest(dir, baseGoFile))
+				tests = append(tests, startTests(dir, baseGoFile, glevels)...)
 			}
 		}
 	}
@@ -142,8 +190,15 @@ func main() {
 			status = "FAIL"
 		}
 		if test.err != nil {
-			status = "FAIL"
 			errStr = test.err.Error()
+			if test.expectFail {
+				errStr += " (expected)"
+			} else {
+				status = "FAIL"
+			}
+		} else if test.expectFail {
+			status = "FAIL"
+			errStr = "unexpected success"
 		}
 		if status == "FAIL" {
 			failed = true
@@ -151,7 +206,8 @@ func main() {
 		resCount[status]++
 		dt := fmt.Sprintf("%.3fs", test.dt.Seconds())
 		if status == "FAIL" {
-			fmt.Printf("# go run run.go -- %s\n%s\nFAIL\t%s\t%s\n",
+			fmt.Printf("# go run run.go -G=%v %s\n%s\nFAIL\t%s\t%s\n",
+				test.glevel,
 				path.Join(test.dir, test.gofile),
 				errStr, test.goFileName(), dt)
 			continue
@@ -270,30 +326,73 @@ type test struct {
 	dir, gofile string
 	donec       chan bool // closed when done
 	dt          time.Duration
+	glevel      int // what -G level this test should use
 
 	src string
 
 	tempDir string
 	err     error
+
+	// expectFail indicates whether the (overall) test recipe is
+	// expected to fail under the current test configuration (e.g., -G=3
+	// or GOEXPERIMENT=unified).
+	expectFail bool
 }
 
-// startTest
-func startTest(dir, gofile string) *test {
-	t := &test{
-		dir:    dir,
-		gofile: gofile,
-		donec:  make(chan bool, 1),
+// initExpectFail initializes t.expectFail based on the build+test
+// configuration. It should only be called for tests known to use
+// types2.
+func (t *test) initExpectFail() {
+	if *force {
+		return
 	}
-	if toRun == nil {
-		toRun = make(chan *test, maxTests)
-		go runTests()
+
+	failureSets := []map[string]bool{types2Failures}
+
+	// Note: gccgo supports more 32-bit architectures than this, but
+	// hopefully the 32-bit failures are fixed before this matters.
+	switch goarch {
+	case "386", "arm", "mips", "mipsle":
+		failureSets = append(failureSets, types2Failures32Bit)
 	}
-	select {
-	case toRun <- t:
-	default:
-		panic("toRun buffer size (maxTests) is too small")
+
+	if unifiedEnabled {
+		failureSets = append(failureSets, unifiedFailures)
+	} else {
+		failureSets = append(failureSets, g3Failures)
 	}
-	return t
+
+	filename := strings.Replace(t.goFileName(), "\\", "/", -1) // goFileName() uses \ on Windows
+
+	for _, set := range failureSets {
+		if set[filename] {
+			t.expectFail = true
+			return
+		}
+	}
+}
+
+func startTests(dir, gofile string, glevels []int) []*test {
+	tests := make([]*test, len(glevels))
+	for i, glevel := range glevels {
+		t := &test{
+			dir:    dir,
+			gofile: gofile,
+			glevel: glevel,
+			donec:  make(chan bool, 1),
+		}
+		if toRun == nil {
+			toRun = make(chan *test, maxTests)
+			go runTests()
+		}
+		select {
+		case toRun <- t:
+		default:
+			panic("toRun buffer size (maxTests) is too small")
+		}
+		tests[i] = t
+	}
+	return tests
 }
 
 // runTests runs tests in parallel, but respecting the order they
@@ -480,12 +579,16 @@ func init() { checkShouldTest() }
 // This must match the flags used for building the standard library,
 // or else the commands will rebuild any needed packages (like runtime)
 // over and over.
-func goGcflags() string {
-	return "-gcflags=all=" + os.Getenv("GO_GCFLAGS")
+func (t *test) goGcflags() string {
+	flags := os.Getenv("GO_GCFLAGS")
+	if t.glevel != 0 {
+		flags = fmt.Sprintf("%s -G=%v", flags, t.glevel)
+	}
+	return "-gcflags=all=" + flags
 }
 
-func goGcflagsIsEmpty() bool {
-	return "" == os.Getenv("GO_GCFLAGS")
+func (t *test) goGcflagsIsEmpty() bool {
+	return "" == os.Getenv("GO_GCFLAGS") && t.glevel == 0
 }
 
 var errTimeout = errors.New("command exceeded time limit")
@@ -541,7 +644,11 @@ func (t *test) run() {
 	singlefilepkgs := false
 	setpkgpaths := false
 	localImports := true
-	f := strings.Fields(action)
+	f, err := splitQuoted(action)
+	if err != nil {
+		t.err = fmt.Errorf("invalid test recipe: %v", err)
+		return
+	}
 	if len(f) > 0 {
 		action = f[0]
 		args = f[1:]
@@ -569,6 +676,8 @@ func (t *test) run() {
 		return
 	}
 
+	goexp := env.GOEXPERIMENT
+
 	// collect flags
 	for len(args) > 0 && strings.HasPrefix(args[0], "-") {
 		switch args[0] {
@@ -595,7 +704,11 @@ func (t *test) run() {
 			}
 		case "-goexperiment": // set GOEXPERIMENT environment
 			args = args[1:]
-			runenv = append(runenv, "GOEXPERIMENT="+args[0])
+			if goexp != "" {
+				goexp += ","
+			}
+			goexp += args[0]
+			runenv = append(runenv, "GOEXPERIMENT="+goexp)
 
 		default:
 			flags = append(flags, args[0])
@@ -616,6 +729,63 @@ func (t *test) run() {
 		}
 	}
 
+	type Tool int
+
+	const (
+		_ Tool = iota
+		AsmCheck
+		Build
+		Run
+		Compile
+	)
+
+	// validForGLevel reports whether the current test is valid to run
+	// at the specified -G level. If so, it may update flags as
+	// necessary to test with -G.
+	validForGLevel := func(tool Tool) bool {
+		hasGFlag := false
+		for _, flag := range flags {
+			if strings.Contains(flag, "-G") {
+				hasGFlag = true
+			}
+		}
+
+		if hasGFlag && t.glevel != 0 {
+			// test provides explicit -G flag already; don't run again
+			if *verbose {
+				fmt.Printf("excl\t%s\n", t.goFileName())
+			}
+			return false
+		}
+
+		if t.glevel == 0 && !hasGFlag && !unifiedEnabled {
+			// tests should always pass when run w/o types2 (i.e., using the
+			// legacy typechecker).
+			return true
+		}
+
+		t.initExpectFail()
+
+		switch tool {
+		case Build, Run:
+			// ok; handled in goGcflags
+
+		case Compile:
+			if !hasGFlag {
+				flags = append(flags, fmt.Sprintf("-G=%v", t.glevel))
+			}
+
+		default:
+			// we don't know how to add -G for this test yet
+			if *verbose {
+				fmt.Printf("excl\t%s\n", t.goFileName())
+			}
+			return false
+		}
+
+		return true
+	}
+
 	t.makeTempDir()
 	if !*keep {
 		defer os.RemoveAll(t.tempDir)
@@ -692,6 +862,10 @@ func (t *test) run() {
 		t.err = fmt.Errorf("unimplemented action %q", action)
 
 	case "asmcheck":
+		if !validForGLevel(AsmCheck) {
+			return
+		}
+
 		// Compile Go file and match the generated assembly
 		// against a set of regexps in comments.
 		ops := t.wantedAsmOpcodes(long)
@@ -746,6 +920,10 @@ func (t *test) run() {
 		return
 
 	case "errorcheck":
+		if !validForGLevel(Compile) {
+			return
+		}
+
 		// Compile Go file.
 		// Fail if wantError is true and compilation was successful and vice versa.
 		// Match errors produced by gc against errors in comments.
@@ -774,72 +952,20 @@ func (t *test) run() {
 			t.updateErrors(string(out), long)
 		}
 		t.err = t.errorCheck(string(out), wantAuto, long, t.gofile)
-		if t.err != nil {
-			return // don't hide error if run below succeeds
-		}
-
-		// The following is temporary scaffolding to get types2 typechecker
-		// up and running against the existing test cases. The explicitly
-		// listed files don't pass yet, usually because the error messages
-		// are slightly different (this list is not complete). Any errorcheck
-		// tests that require output from analysis phases past initial type-
-		// checking are also excluded since these phases are not running yet.
-		// We can get rid of this code once types2 is fully plugged in.
-
-		// For now we're done when we can't handle the file or some of the flags.
-		// The first goal is to eliminate the excluded list; the second goal is to
-		// eliminate the flag list.
-
-		// Excluded files.
-		filename := strings.Replace(t.goFileName(), "\\", "/", -1) // goFileName() uses \ on Windows
-		if excluded[filename] {
-			if *verbose {
-				fmt.Printf("excl\t%s\n", filename)
-			}
-			return // cannot handle file yet
-		}
-
-		// Excluded flags.
-		for _, flag := range flags {
-			for _, pattern := range []string{
-				"-m",
-			} {
-				if strings.Contains(flag, pattern) {
-					if *verbose {
-						fmt.Printf("excl\t%s\t%s\n", filename, flags)
-					}
-					return // cannot handle flag
-				}
-			}
-		}
-
-		// Run errorcheck again with -G option (new typechecker).
-		cmdline = []string{goTool(), "tool", "compile", "-G=3", "-C", "-e", "-o", "a.o"}
-		// No need to add -dynlink even if linkshared if we're just checking for errors...
-		cmdline = append(cmdline, flags...)
-		cmdline = append(cmdline, long)
-		out, err = runcmd(cmdline...)
-		if wantError {
-			if err == nil {
-				t.err = fmt.Errorf("compilation succeeded unexpectedly\n%s", out)
-				return
-			}
-		} else {
-			if err != nil {
-				t.err = err
-				return
-			}
-		}
-		if *updateErrors {
-			t.updateErrors(string(out), long)
-		}
-		t.err = t.errorCheck(string(out), wantAuto, long, t.gofile)
 
 	case "compile":
+		if !validForGLevel(Compile) {
+			return
+		}
+
 		// Compile Go file.
 		_, t.err = compileFile(runcmd, long, flags)
 
 	case "compiledir":
+		if !validForGLevel(Compile) {
+			return
+		}
+
 		// Compile all files in the directory as packages in lexicographic order.
 		longdir := filepath.Join(cwd, t.goDirName())
 		pkgs, err := goDirPackages(longdir, singlefilepkgs)
@@ -855,6 +981,10 @@ func (t *test) run() {
 		}
 
 	case "errorcheckdir", "errorcheckandrundir":
+		if !validForGLevel(Compile) {
+			return
+		}
+
 		flags = append(flags, "-d=panic")
 		// Compile and errorCheck all files in the directory as packages in lexicographic order.
 		// If errorcheckdir and wantError, compilation of the last package must fail.
@@ -900,6 +1030,10 @@ func (t *test) run() {
 		fallthrough
 
 	case "rundir":
+		if !validForGLevel(Run) {
+			return
+		}
+
 		// Compile all files in the directory as packages in lexicographic order.
 		// In case of errorcheckandrundir, ignore failed compilation of the package before the last.
 		// Link as if the last file is the main package, run it.
@@ -958,6 +1092,10 @@ func (t *test) run() {
 		}
 
 	case "runindir":
+		if !validForGLevel(Run) {
+			return
+		}
+
 		// Make a shallow copy of t.goDirName() in its own module and GOPATH, and
 		// run "go run ." in it. The module path (and hence import path prefix) of
 		// the copy is equal to the basename of the source directory.
@@ -983,7 +1121,7 @@ func (t *test) run() {
 			return
 		}
 
-		cmd := []string{goTool(), "run", goGcflags()}
+		cmd := []string{goTool(), "run", t.goGcflags()}
 		if *linkshared {
 			cmd = append(cmd, "-linkshared")
 		}
@@ -997,13 +1135,21 @@ func (t *test) run() {
 		t.checkExpectedOutput(out)
 
 	case "build":
+		if !validForGLevel(Build) {
+			return
+		}
+
 		// Build Go file.
-		_, err := runcmd(goTool(), "build", goGcflags(), "-o", "a.exe", long)
+		_, err := runcmd(goTool(), "build", t.goGcflags(), "-o", "a.exe", long)
 		if err != nil {
 			t.err = err
 		}
 
 	case "builddir", "buildrundir":
+		if !validForGLevel(Build) {
+			return
+		}
+
 		// Build an executable from all the .go and .s files in a subdirectory.
 		// Run it and verify its output in the buildrundir case.
 		longdir := filepath.Join(cwd, t.goDirName())
@@ -1083,10 +1229,14 @@ func (t *test) run() {
 		}
 
 	case "buildrun":
+		if !validForGLevel(Build) {
+			return
+		}
+
 		// Build an executable from Go file, then run it, verify its output.
 		// Useful for timeout tests where failure mode is infinite loop.
 		// TODO: not supported on NaCl
-		cmd := []string{goTool(), "build", goGcflags(), "-o", "a.exe"}
+		cmd := []string{goTool(), "build", t.goGcflags(), "-o", "a.exe"}
 		if *linkshared {
 			cmd = append(cmd, "-linkshared")
 		}
@@ -1108,13 +1258,17 @@ func (t *test) run() {
 		t.checkExpectedOutput(out)
 
 	case "run":
+		if !validForGLevel(Run) {
+			return
+		}
+
 		// Run Go file if no special go command flags are provided;
 		// otherwise build an executable and run it.
 		// Verify the output.
 		runInDir = ""
 		var out []byte
 		var err error
-		if len(flags)+len(args) == 0 && goGcflagsIsEmpty() && !*linkshared && goarch == runtime.GOARCH && goos == runtime.GOOS {
+		if len(flags)+len(args) == 0 && t.goGcflagsIsEmpty() && !*linkshared && goarch == runtime.GOARCH && goos == runtime.GOOS && goexp == env.GOEXPERIMENT {
 			// If we're not using special go command flags,
 			// skip all the go command machinery.
 			// This avoids any time the go command would
@@ -1136,7 +1290,7 @@ func (t *test) run() {
 			}
 			out, err = runcmd(append([]string{exe}, args...)...)
 		} else {
-			cmd := []string{goTool(), "run", goGcflags()}
+			cmd := []string{goTool(), "run", t.goGcflags()}
 			if *linkshared {
 				cmd = append(cmd, "-linkshared")
 			}
@@ -1151,6 +1305,10 @@ func (t *test) run() {
 		t.checkExpectedOutput(out)
 
 	case "runoutput":
+		if !validForGLevel(Run) {
+			return
+		}
+
 		// Run Go file and write its output into temporary Go file.
 		// Run generated Go file and verify its output.
 		rungatec <- true
@@ -1158,7 +1316,7 @@ func (t *test) run() {
 			<-rungatec
 		}()
 		runInDir = ""
-		cmd := []string{goTool(), "run", goGcflags()}
+		cmd := []string{goTool(), "run", t.goGcflags()}
 		if *linkshared {
 			cmd = append(cmd, "-linkshared")
 		}
@@ -1173,7 +1331,7 @@ func (t *test) run() {
 			t.err = fmt.Errorf("write tempfile:%s", err)
 			return
 		}
-		cmd = []string{goTool(), "run", goGcflags()}
+		cmd = []string{goTool(), "run", t.goGcflags()}
 		if *linkshared {
 			cmd = append(cmd, "-linkshared")
 		}
@@ -1186,10 +1344,14 @@ func (t *test) run() {
 		t.checkExpectedOutput(out)
 
 	case "errorcheckoutput":
+		if !validForGLevel(Compile) {
+			return
+		}
+
 		// Run Go file and write its output into temporary Go file.
 		// Compile and errorCheck generated Go file.
 		runInDir = ""
-		cmd := []string{goTool(), "run", goGcflags()}
+		cmd := []string{goTool(), "run", t.goGcflags()}
 		if *linkshared {
 			cmd = append(cmd, "-linkshared")
 		}
@@ -1941,65 +2103,165 @@ func overlayDir(dstRoot, srcRoot string) error {
 	})
 }
 
+// The following is temporary scaffolding to get types2 typechecker
+// up and running against the existing test cases. The explicitly
+// listed files don't pass yet, usually because the error messages
+// are slightly different (this list is not complete). Any errorcheck
+// tests that require output from analysis phases past initial type-
+// checking are also excluded since these phases are not running yet.
+// We can get rid of this code once types2 is fully plugged in.
+
 // List of files that the compiler cannot errorcheck with the new typechecker (compiler -G option).
 // Temporary scaffolding until we pass all the tests at which point this map can be removed.
-var excluded = map[string]bool{
-	"complit1.go":     true, // types2 reports extra errors
-	"const2.go":       true, // types2 not run after syntax errors
-	"ddd1.go":         true, // issue #42987
-	"directive.go":    true, // misplaced compiler directive checks
-	"float_lit3.go":   true, // types2 reports extra errors
-	"import1.go":      true, // types2 reports extra errors
-	"import5.go":      true, // issue #42988
-	"import6.go":      true, // issue #43109
-	"initializerr.go": true, // types2 reports extra errors
-	"linkname2.go":    true, // error reported by noder (not running for types2 errorcheck test)
-	"notinheap.go":    true, // types2 doesn't report errors about conversions that are invalid due to //go:notinheap
-	"shift1.go":       true, // issue #42989
-	"typecheck.go":    true, // invalid function is not causing errors when called
-	"writebarrier.go": true, // correct diagnostics, but different lines (probably irgen's fault)
+var types2Failures = setOf(
+	"directive.go",    // misplaced compiler directive checks
+	"float_lit3.go",   // types2 reports extra errors
+	"import1.go",      // types2 reports extra errors
+	"import6.go",      // issue #43109
+	"initializerr.go", // types2 reports extra errors
+	"linkname2.go",    // error reported by noder (not running for types2 errorcheck test)
+	"notinheap.go",    // types2 doesn't report errors about conversions that are invalid due to //go:notinheap
+	"shift1.go",       // issue #42989
+	"typecheck.go",    // invalid function is not causing errors when called
 
-	"fixedbugs/bug176.go":    true, // types2 reports all errors (pref: types2)
-	"fixedbugs/bug195.go":    true, // types2 reports slightly different (but correct) bugs
-	"fixedbugs/bug228.go":    true, // types2 not run after syntax errors
-	"fixedbugs/bug231.go":    true, // types2 bug? (same error reported twice)
-	"fixedbugs/bug255.go":    true, // types2 reports extra errors
-	"fixedbugs/bug351.go":    true, // types2 reports extra errors
-	"fixedbugs/bug374.go":    true, // types2 reports extra errors
-	"fixedbugs/bug385_32.go": true, // types2 doesn't produce missing error "type .* too large" (32-bit specific)
-	"fixedbugs/bug388.go":    true, // types2 not run due to syntax errors
-	"fixedbugs/bug412.go":    true, // types2 produces a follow-on error
+	"interface/private.go", // types2 phrases errors differently (doesn't use non-spec "private" term)
 
-	"fixedbugs/issue11590.go":  true, // types2 doesn't report a follow-on error (pref: types2)
-	"fixedbugs/issue11610.go":  true, // types2 not run after syntax errors
-	"fixedbugs/issue11614.go":  true, // types2 reports an extra error
-	"fixedbugs/issue13415.go":  true, // declared but not used conflict
-	"fixedbugs/issue14520.go":  true, // missing import path error by types2
-	"fixedbugs/issue16428.go":  true, // types2 reports two instead of one error
-	"fixedbugs/issue17038.go":  true, // types2 doesn't report a follow-on error (pref: types2)
-	"fixedbugs/issue17645.go":  true, // multiple errors on same line
-	"fixedbugs/issue18331.go":  true, // missing error about misuse of //go:noescape (irgen needs code from noder)
-	"fixedbugs/issue18393.go":  true, // types2 not run after syntax errors
-	"fixedbugs/issue19012.go":  true, // multiple errors on same line
-	"fixedbugs/issue20233.go":  true, // types2 reports two instead of one error (pref: compiler)
-	"fixedbugs/issue20245.go":  true, // types2 reports two instead of one error (pref: compiler)
-	"fixedbugs/issue20250.go":  true, // correct diagnostics, but different lines (probably irgen's fault)
-	"fixedbugs/issue21979.go":  true, // types2 doesn't report a follow-on error (pref: types2)
-	"fixedbugs/issue23732.go":  true, // types2 reports different (but ok) line numbers
-	"fixedbugs/issue25958.go":  true, // types2 doesn't report a follow-on error (pref: types2)
-	"fixedbugs/issue28079b.go": true, // types2 reports follow-on errors
-	"fixedbugs/issue28268.go":  true, // types2 reports follow-on errors
-	"fixedbugs/issue33460.go":  true, // types2 reports alternative positions in separate error
-	"fixedbugs/issue41575.go":  true, // types2 reports alternative positions in separate error
-	"fixedbugs/issue42058a.go": true, // types2 doesn't report "channel element type too large"
-	"fixedbugs/issue42058b.go": true, // types2 doesn't report "channel element type too large"
-	"fixedbugs/issue4232.go":   true, // types2 reports (correct) extra errors
-	"fixedbugs/issue4452.go":   true, // types2 reports (correct) extra errors
-	"fixedbugs/issue5609.go":   true, // types2 needs a better error message
-	"fixedbugs/issue6889.go":   true, // types2 can handle this without constant overflow
-	"fixedbugs/issue7525.go":   true, // types2 reports init cycle error on different line - ok otherwise
-	"fixedbugs/issue7525b.go":  true, // types2 reports init cycle error on different line - ok otherwise
-	"fixedbugs/issue7525c.go":  true, // types2 reports init cycle error on different line - ok otherwise
-	"fixedbugs/issue7525d.go":  true, // types2 reports init cycle error on different line - ok otherwise
-	"fixedbugs/issue7525e.go":  true, // types2 reports init cycle error on different line - ok otherwise
+	"fixedbugs/bug176.go", // types2 reports all errors (pref: types2)
+	"fixedbugs/bug195.go", // types2 reports slightly different (but correct) bugs
+	"fixedbugs/bug228.go", // types2 doesn't run when there are syntax errors
+	"fixedbugs/bug231.go", // types2 bug? (same error reported twice)
+	"fixedbugs/bug255.go", // types2 reports extra errors
+	"fixedbugs/bug374.go", // types2 reports extra errors
+	"fixedbugs/bug388.go", // types2 not run due to syntax errors
+	"fixedbugs/bug412.go", // types2 produces a follow-on error
+
+	"fixedbugs/issue10700.go",  // types2 reports ok hint, but does not match regexp
+	"fixedbugs/issue11590.go",  // types2 doesn't report a follow-on error (pref: types2)
+	"fixedbugs/issue11610.go",  // types2 not run after syntax errors
+	"fixedbugs/issue11614.go",  // types2 reports an extra error
+	"fixedbugs/issue14520.go",  // missing import path error by types2
+	"fixedbugs/issue16428.go",  // types2 reports two instead of one error
+	"fixedbugs/issue17038.go",  // types2 doesn't report a follow-on error (pref: types2)
+	"fixedbugs/issue17645.go",  // multiple errors on same line
+	"fixedbugs/issue18331.go",  // missing error about misuse of //go:noescape (irgen needs code from noder)
+	"fixedbugs/issue18419.go",  // types2 reports
+	"fixedbugs/issue19012.go",  // multiple errors on same line
+	"fixedbugs/issue20233.go",  // types2 reports two instead of one error (pref: compiler)
+	"fixedbugs/issue20245.go",  // types2 reports two instead of one error (pref: compiler)
+	"fixedbugs/issue21979.go",  // types2 doesn't report a follow-on error (pref: types2)
+	"fixedbugs/issue23732.go",  // types2 reports different (but ok) line numbers
+	"fixedbugs/issue25958.go",  // types2 doesn't report a follow-on error (pref: types2)
+	"fixedbugs/issue28079b.go", // types2 reports follow-on errors
+	"fixedbugs/issue28268.go",  // types2 reports follow-on errors
+	"fixedbugs/issue31053.go",  // types2 reports "unknown field" instead of "cannot refer to unexported field"
+	"fixedbugs/issue33460.go",  // types2 reports alternative positions in separate error
+	"fixedbugs/issue42058a.go", // types2 doesn't report "channel element type too large"
+	"fixedbugs/issue42058b.go", // types2 doesn't report "channel element type too large"
+	"fixedbugs/issue4232.go",   // types2 reports (correct) extra errors
+	"fixedbugs/issue4452.go",   // types2 reports (correct) extra errors
+	"fixedbugs/issue4510.go",   // types2 reports different (but ok) line numbers
+	"fixedbugs/issue47201.go",  // types2 spells the error message differently
+	"fixedbugs/issue5609.go",   // types2 needs a better error message
+	"fixedbugs/issue7525b.go",  // types2 reports init cycle error on different line - ok otherwise
+	"fixedbugs/issue7525c.go",  // types2 reports init cycle error on different line - ok otherwise
+	"fixedbugs/issue7525d.go",  // types2 reports init cycle error on different line - ok otherwise
+	"fixedbugs/issue7525e.go",  // types2 reports init cycle error on different line - ok otherwise
+	"fixedbugs/issue7525.go",   // types2 reports init cycle error on different line - ok otherwise
+)
+
+var types2Failures32Bit = setOf(
+	"printbig.go",             // large untyped int passed to print (32-bit)
+	"fixedbugs/bug114.go",     // large untyped int passed to println (32-bit)
+	"fixedbugs/issue23305.go", // large untyped int passed to println (32-bit)
+	"fixedbugs/bug385_32.go",  // types2 doesn't produce missing error "type .* too large" (32-bit specific)
+)
+
+var g3Failures = setOf(
+	"writebarrier.go", // correct diagnostics, but different lines (probably irgen's fault)
+
+	"fixedbugs/issue30862.go", // -G=3 doesn't handle //go:nointerface
+
+	"typeparam/nested.go", // -G=3 doesn't support function-local types with generics
+
+	"typeparam/mdempsky/4.go",  // -G=3 can't export functions with labeled breaks in loops
+	"typeparam/mdempsky/15.go", // ICE in (*irgen).buildClosure
+)
+
+var unifiedFailures = setOf(
+	"closure3.go", // unified IR numbers closures differently than -d=inlfuncswithclosures
+	"escape4.go",  // unified IR can inline f5 and f6; test doesn't expect this
+	"inline.go",   // unified IR reports function literal diagnostics on different lines than -d=inlfuncswithclosures
+
+	"fixedbugs/issue42284.go", // prints "T(0) does not escape", but test expects "a.I(a.T(0)) does not escape"
+	"fixedbugs/issue7921.go",  // prints "… escapes to heap", but test expects "string(…) escapes to heap"
+)
+
+func setOf(keys ...string) map[string]bool {
+	m := make(map[string]bool, len(keys))
+	for _, key := range keys {
+		m[key] = true
+	}
+	return m
+}
+
+// splitQuoted splits the string s around each instance of one or more consecutive
+// white space characters while taking into account quotes and escaping, and
+// returns an array of substrings of s or an empty list if s contains only white space.
+// Single quotes and double quotes are recognized to prevent splitting within the
+// quoted region, and are removed from the resulting substrings. If a quote in s
+// isn't closed err will be set and r will have the unclosed argument as the
+// last element. The backslash is used for escaping.
+//
+// For example, the following string:
+//
+//     a b:"c d" 'e''f'  "g\""
+//
+// Would be parsed as:
+//
+//     []string{"a", "b:c d", "ef", `g"`}
+//
+// [copied from src/go/build/build.go]
+func splitQuoted(s string) (r []string, err error) {
+	var args []string
+	arg := make([]rune, len(s))
+	escaped := false
+	quoted := false
+	quote := '\x00'
+	i := 0
+	for _, rune := range s {
+		switch {
+		case escaped:
+			escaped = false
+		case rune == '\\':
+			escaped = true
+			continue
+		case quote != '\x00':
+			if rune == quote {
+				quote = '\x00'
+				continue
+			}
+		case rune == '"' || rune == '\'':
+			quoted = true
+			quote = rune
+			continue
+		case unicode.IsSpace(rune):
+			if quoted || i > 0 {
+				quoted = false
+				args = append(args, string(arg[:i]))
+				i = 0
+			}
+			continue
+		}
+		arg[i] = rune
+		i++
+	}
+	if quoted || i > 0 {
+		args = append(args, string(arg[:i]))
+	}
+	if quote != 0 {
+		err = errors.New("unclosed quote")
+	} else if escaped {
+		err = errors.New("unfinished escaping")
+	}
+	return args, err
 }
diff --git a/test/typeparam/absdiff.go b/test/typeparam/absdiff.go
index 1381d7c92c9..cad6e84c4e4 100644
--- a/test/typeparam/absdiff.go
+++ b/test/typeparam/absdiff.go
@@ -12,10 +12,10 @@ import (
 )
 
 type Numeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		complex64, complex128
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~complex64 | ~complex128
 }
 
 // numericAbs matches numeric types with an Abs method.
@@ -33,14 +33,14 @@ func absDifference[T numericAbs[T]](a, b T) T {
 
 // orderedNumeric matches numeric types that support the < operator.
 type orderedNumeric interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
 }
 
 // Complex matches the two complex types, which do not have a < operator.
 type Complex interface {
-	type complex64, complex128
+	~complex64 | ~complex128
 }
 
 // orderedAbs is a helper type that defines an Abs method for
@@ -48,8 +48,7 @@ type Complex interface {
 type orderedAbs[T orderedNumeric] T
 
 func (a orderedAbs[T]) Abs() orderedAbs[T] {
-	// TODO(danscales): orderedAbs[T] conversion shouldn't be needed
-	if a < orderedAbs[T](0) {
+	if a < 0 {
 		return -a
 	}
 	return a
@@ -62,7 +61,7 @@ type complexAbs[T Complex] T
 func (a complexAbs[T]) Abs() complexAbs[T] {
 	r := float64(real(a))
 	i := float64(imag(a))
-	d := math.Sqrt(r * r + i * i)
+	d := math.Sqrt(r*r + i*i)
 	return complexAbs[T](complex(d, 0))
 }
 
@@ -89,10 +88,10 @@ func main() {
 		panic(fmt.Sprintf("got = %v, want = %v", got, want))
 	}
 
-	if got, want := complexAbsDifference(5.0 + 2.0i, 2.0 - 2.0i), 5+0i; got != want {
+	if got, want := complexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
 		panic(fmt.Sprintf("got = %v, want = %v", got, want))
 	}
-	if got, want := complexAbsDifference(2.0 - 2.0i, 5.0 + 2.0i), 5+0i; got != want {
+	if got, want := complexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
 		panic(fmt.Sprintf("got = %v, want = %v", got, want))
 	}
 }
diff --git a/test/typeparam/absdiffimp.dir/a.go b/test/typeparam/absdiffimp.dir/a.go
new file mode 100644
index 00000000000..7b5bfbe2ace
--- /dev/null
+++ b/test/typeparam/absdiffimp.dir/a.go
@@ -0,0 +1,75 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+import (
+	"math"
+)
+
+type Numeric interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~complex64 | ~complex128
+}
+
+// numericAbs matches numeric types with an Abs method.
+type numericAbs[T any] interface {
+	Numeric
+	Abs() T
+}
+
+// AbsDifference computes the absolute value of the difference of
+// a and b, where the absolute value is determined by the Abs method.
+func absDifference[T numericAbs[T]](a, b T) T {
+	d := a - b
+	return d.Abs()
+}
+
+// orderedNumeric matches numeric types that support the < operator.
+type orderedNumeric interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
+}
+
+// Complex matches the two complex types, which do not have a < operator.
+type Complex interface {
+	~complex64 | ~complex128
+}
+
+// orderedAbs is a helper type that defines an Abs method for
+// ordered numeric types.
+type orderedAbs[T orderedNumeric] T
+
+func (a orderedAbs[T]) Abs() orderedAbs[T] {
+	if a < 0 {
+		return -a
+	}
+	return a
+}
+
+// complexAbs is a helper type that defines an Abs method for
+// complex types.
+type complexAbs[T Complex] T
+
+func (a complexAbs[T]) Abs() complexAbs[T] {
+	r := float64(real(a))
+	i := float64(imag(a))
+	d := math.Sqrt(r*r + i*i)
+	return complexAbs[T](complex(d, 0))
+}
+
+// OrderedAbsDifference returns the absolute value of the difference
+// between a and b, where a and b are of an ordered type.
+func OrderedAbsDifference[T orderedNumeric](a, b T) T {
+	return T(absDifference(orderedAbs[T](a), orderedAbs[T](b)))
+}
+
+// ComplexAbsDifference returns the absolute value of the difference
+// between a and b, where a and b are of a complex type.
+func ComplexAbsDifference[T Complex](a, b T) T {
+	return T(absDifference(complexAbs[T](a), complexAbs[T](b)))
+}
diff --git a/test/typeparam/absdiffimp.dir/main.go b/test/typeparam/absdiffimp.dir/main.go
new file mode 100644
index 00000000000..8eefdbdf384
--- /dev/null
+++ b/test/typeparam/absdiffimp.dir/main.go
@@ -0,0 +1,29 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	if got, want := a.OrderedAbsDifference(1.0, -2.0), 3.0; got != want {
+		panic(fmt.Sprintf("got = %v, want = %v", got, want))
+	}
+	if got, want := a.OrderedAbsDifference(-1.0, 2.0), 3.0; got != want {
+		panic(fmt.Sprintf("got = %v, want = %v", got, want))
+	}
+	if got, want := a.OrderedAbsDifference(-20, 15), 35; got != want {
+		panic(fmt.Sprintf("got = %v, want = %v", got, want))
+	}
+
+	if got, want := a.ComplexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
+		panic(fmt.Sprintf("got = %v, want = %v", got, want))
+	}
+	if got, want := a.ComplexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
+		panic(fmt.Sprintf("got = %v, want = %v", got, want))
+	}
+}
diff --git a/test/typeparam/absdiffimp.go b/test/typeparam/absdiffimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/absdiffimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/adder.go b/test/typeparam/adder.go
index 0c25ad4ef2d..79319bd2369 100644
--- a/test/typeparam/adder.go
+++ b/test/typeparam/adder.go
@@ -11,19 +11,19 @@ import (
 )
 
 type AddType interface {
-	type int, int64, string
+	int | int64 | string
 }
 
-// _Add can add numbers or strings
-func _Add[T AddType](a, b T) T {
+// Add can add numbers or strings
+func Add[T AddType](a, b T) T {
 	return a + b
 }
 
 func main() {
-	if got, want := _Add(5, 3), 8; got != want {
+	if got, want := Add(5, 3), 8; got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
-	if got, want := _Add("ab", "cd"), "abcd"; got != want {
+	if got, want := Add("ab", "cd"), "abcd"; got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 }
diff --git a/test/typeparam/aliasimp.dir/a.go b/test/typeparam/aliasimp.dir/a.go
new file mode 100644
index 00000000000..c64e87c10fa
--- /dev/null
+++ b/test/typeparam/aliasimp.dir/a.go
@@ -0,0 +1,9 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Rimp[T any] struct {
+	F T
+}
diff --git a/test/typeparam/aliasimp.dir/main.go b/test/typeparam/aliasimp.dir/main.go
new file mode 100644
index 00000000000..221a6c758dc
--- /dev/null
+++ b/test/typeparam/aliasimp.dir/main.go
@@ -0,0 +1,38 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "a"
+
+type R[T any] struct {
+	F T
+}
+
+type S = R
+
+type Sint = R[int]
+
+type Simp = a.Rimp
+
+type SimpString Simp[string]
+
+func main() {
+	var s S[int]
+	if s.F != 0 {
+		panic(s.F)
+	}
+	var s2 Sint
+	if s2.F != 0 {
+		panic(s2.F)
+	}
+	var s3 Simp[string]
+	if s3.F != "" {
+		panic(s3.F)
+	}
+	var s4 SimpString
+	if s4.F != "" {
+		panic(s4.F)
+	}
+}
diff --git a/test/typeparam/aliasimp.go b/test/typeparam/aliasimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/aliasimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/boundmethod.go b/test/typeparam/boundmethod.go
new file mode 100644
index 00000000000..22f416422da
--- /dev/null
+++ b/test/typeparam/boundmethod.go
@@ -0,0 +1,106 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This test illustrates how a type bound method (String below) can be implemented
+// either by a concrete type (myint below) or a instantiated generic type
+// (StringInt[myint] below).
+
+package main
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+type myint int
+
+//go:noinline
+func (m myint) String() string {
+	return strconv.Itoa(int(m))
+}
+
+type Stringer interface {
+	String() string
+}
+
+func stringify[T Stringer](s []T) (ret []string) {
+	for _, v := range s {
+		// Test normal bounds method call on type param
+		x1 := v.String()
+
+		// Test converting type param to its bound interface first
+		v1 := Stringer(v)
+		x2 := v1.String()
+
+		// Test method expression with type param type
+		f1 := T.String
+		x3 := f1(v)
+
+		// Test creating and calling closure equivalent to the method expression
+		f2 := func(v1 T) string {
+			return Stringer(v1).String()
+		}
+		x4 := f2(v)
+
+		if x1 != x2 || x2 != x3 || x3 != x4 {
+			panic(fmt.Sprintf("Mismatched values %v, %v, %v, %v\n", x1, x2, x3, x4))
+		}
+
+		ret = append(ret, v.String())
+	}
+	return ret
+}
+
+type Ints interface {
+	~int32 | ~int
+}
+
+type StringInt[T Ints] T
+
+//go:noinline
+func (m StringInt[T]) String() string {
+	return strconv.Itoa(int(m))
+}
+
+type StringStruct[T Ints] struct {
+	f T
+}
+
+func (m StringStruct[T]) String() string {
+	return strconv.Itoa(int(m.f))
+}
+
+func main() {
+	x := []myint{myint(1), myint(2), myint(3)}
+
+	// stringify on a normal type, whose bound method is associated with the base type.
+	got := stringify(x)
+	want := []string{"1", "2", "3"}
+	if !reflect.DeepEqual(got, want) {
+		panic(fmt.Sprintf("got %s, want %s", got, want))
+	}
+
+	x2 := []StringInt[myint]{StringInt[myint](5), StringInt[myint](7), StringInt[myint](6)}
+
+	// stringify on an instantiated type, whose bound method is associated with
+	// the generic type StringInt[T], which maps directly to T.
+	got2 := stringify(x2)
+	want2 := []string{ "5", "7", "6" }
+	if !reflect.DeepEqual(got2, want2) {
+		panic(fmt.Sprintf("got %s, want %s", got2, want2))
+	}
+
+	// stringify on an instantiated type, whose bound method is associated with
+	// the generic type StringStruct[T], which maps to a struct containing T.
+	x3 := []StringStruct[myint]{StringStruct[myint]{f: 11}, StringStruct[myint]{f: 10}, StringStruct[myint]{f: 9}}
+
+	got3 := stringify(x3)
+	want3 := []string{ "11", "10", "9" }
+	if !reflect.DeepEqual(got3, want3) {
+		panic(fmt.Sprintf("got %s, want %s", got3, want3))
+	}
+}
diff --git a/test/typeparam/builtins.go b/test/typeparam/builtins.go
new file mode 100644
index 00000000000..844cdae8ab3
--- /dev/null
+++ b/test/typeparam/builtins.go
@@ -0,0 +1,111 @@
+// compile -G=3
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file tests built-in calls on generic types.
+
+// derived and expanded from cmd/compile/internal/types2/testdata/check/builtins.go2
+
+package builtins
+
+// close
+
+type C0 interface{ int }
+type C1 interface{ chan int }
+type C2 interface{ chan int | <-chan int }
+type C3 interface{ chan int | chan float32 }
+type C4 interface{ chan int | chan<- int }
+type C5[T any] interface{ ~chan T | chan<- T }
+
+func f1[T C1](ch T) {
+	close(ch)
+}
+
+func f2[T C3](ch T) {
+	close(ch)
+}
+
+func f3[T C4](ch T) {
+	close(ch)
+}
+
+func f4[T C5[X], X any](ch T) {
+	close(ch)
+}
+
+// delete
+
+type M0 interface{ int }
+type M1 interface{ map[string]int }
+type M2 interface {
+	map[string]int | map[string]float64
+}
+type M3 interface{ map[string]int | map[rune]int }
+type M4[K comparable, V any] interface{ map[K]V | map[rune]V }
+
+func g1[T M1](m T) {
+	delete(m, "foo")
+}
+
+func g2[T M2](m T) {
+	delete(m, "foo")
+}
+
+func g3[T M4[rune, V], V any](m T) {
+	delete(m, 'k')
+}
+
+// make
+
+func m1[
+	S1 interface{ []int },
+	S2 interface{ []int | chan int },
+
+	M1 interface{ map[string]int },
+	M2 interface{ map[string]int | chan int },
+
+	C1 interface{ chan int },
+	C2 interface{ chan int | chan string },
+]() {
+	type S0 []int
+	_ = make([]int, 10)
+	_ = make(S0, 10)
+	_ = make(S1, 10)
+	_ = make(S1, 10, 20)
+
+	type M0 map[string]int
+	_ = make(map[string]int)
+	_ = make(M0)
+	_ = make(M1)
+	_ = make(M1, 10)
+
+	type C0 chan int
+	_ = make(chan int)
+	_ = make(C0)
+	_ = make(C1)
+	_ = make(C1, 10)
+}
+
+// len/cap
+
+type Slice[T any] interface {
+	[]T
+}
+
+func c1[T any, S Slice[T]]() {
+	x := make(S, 5, 10)
+	_ = len(x)
+	_ = cap(x)
+}
+
+// append
+
+func a1[T any, S Slice[T]]() {
+	x := make(S, 5)
+	y := make(S, 2)
+	var z T
+	_ = append(x, y...)
+	_ = append(x, z)
+}
diff --git a/test/typeparam/chans.go b/test/typeparam/chans.go
index 2fcd4af75e5..c30c21c37bf 100644
--- a/test/typeparam/chans.go
+++ b/test/typeparam/chans.go
@@ -183,7 +183,7 @@ func _Ranger[Elem any]() (*_Sender[Elem], *_Receiver[Elem]) {
 		values: c,
 		done:   d,
 	}
-	r := &_Receiver[Elem] {
+	r := &_Receiver[Elem]{
 		values: c,
 		done:   d,
 	}
diff --git a/test/typeparam/chansimp.dir/a.go b/test/typeparam/chansimp.dir/a.go
new file mode 100644
index 00000000000..73219927041
--- /dev/null
+++ b/test/typeparam/chansimp.dir/a.go
@@ -0,0 +1,232 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+import (
+	"context"
+	"runtime"
+)
+
+// Equal reports whether two slices are equal: the same length and all
+// elements equal. All floating point NaNs are considered equal.
+func SliceEqual[Elem comparable](s1, s2 []Elem) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if v1 != v2 {
+			isNaN := func(f Elem) bool { return f != f }
+			if !isNaN(v1) || !isNaN(v2) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// ReadAll reads from c until the channel is closed or the context is
+// canceled, returning all the values read.
+func ReadAll[Elem any](ctx context.Context, c <-chan Elem) []Elem {
+	var r []Elem
+	for {
+		select {
+		case <-ctx.Done():
+			return r
+		case v, ok := <-c:
+			if !ok {
+				return r
+			}
+			r = append(r, v)
+		}
+	}
+}
+
+// Merge merges two channels into a single channel.
+// This will leave a goroutine running until either both channels are closed
+// or the context is canceled, at which point the returned channel is closed.
+func Merge[Elem any](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem {
+	r := make(chan Elem)
+	go func(ctx context.Context, c1, c2 <-chan Elem, r chan<- Elem) {
+		defer close(r)
+		for c1 != nil || c2 != nil {
+			select {
+			case <-ctx.Done():
+				return
+			case v1, ok := <-c1:
+				if ok {
+					r <- v1
+				} else {
+					c1 = nil
+				}
+			case v2, ok := <-c2:
+				if ok {
+					r <- v2
+				} else {
+					c2 = nil
+				}
+			}
+		}
+	}(ctx, c1, c2, r)
+	return r
+}
+
+// Filter calls f on each value read from c. If f returns true the value
+// is sent on the returned channel. This will leave a goroutine running
+// until c is closed or the context is canceled, at which point the
+// returned channel is closed.
+func Filter[Elem any](ctx context.Context, c <-chan Elem, f func(Elem) bool) <-chan Elem {
+	r := make(chan Elem)
+	go func(ctx context.Context, c <-chan Elem, f func(Elem) bool, r chan<- Elem) {
+		defer close(r)
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case v, ok := <-c:
+				if !ok {
+					return
+				}
+				if f(v) {
+					r <- v
+				}
+			}
+		}
+	}(ctx, c, f, r)
+	return r
+}
+
+// Sink returns a channel that discards all values sent to it.
+// This will leave a goroutine running until the context is canceled
+// or the returned channel is closed.
+func Sink[Elem any](ctx context.Context) chan<- Elem {
+	r := make(chan Elem)
+	go func(ctx context.Context, r <-chan Elem) {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case _, ok := <-r:
+				if !ok {
+					return
+				}
+			}
+		}
+	}(ctx, r)
+	return r
+}
+
+// An Exclusive is a value that may only be used by a single goroutine
+// at a time. This is implemented using channels rather than a mutex.
+type Exclusive[Val any] struct {
+	c chan Val
+}
+
+// MakeExclusive makes an initialized exclusive value.
+func MakeExclusive[Val any](initial Val) *Exclusive[Val] {
+	r := &Exclusive[Val]{
+		c: make(chan Val, 1),
+	}
+	r.c <- initial
+	return r
+}
+
+// Acquire acquires the exclusive value for private use.
+// It must be released using the Release method.
+func (e *Exclusive[Val]) Acquire() Val {
+	return <-e.c
+}
+
+// TryAcquire attempts to acquire the value. The ok result reports whether
+// the value was acquired. If the value is acquired, it must be released
+// using the Release method.
+func (e *Exclusive[Val]) TryAcquire() (v Val, ok bool) {
+	select {
+	case r := <-e.c:
+		return r, true
+	default:
+		return v, false
+	}
+}
+
+// Release updates and releases the value.
+// This method panics if the value has not been acquired.
+func (e *Exclusive[Val]) Release(v Val) {
+	select {
+	case e.c <- v:
+	default:
+		panic("Exclusive Release without Acquire")
+	}
+}
+
+// Ranger returns a Sender and a Receiver. The Receiver provides a
+// Next method to retrieve values. The Sender provides a Send method
+// to send values and a Close method to stop sending values. The Next
+// method indicates when the Sender has been closed, and the Send
+// method indicates when the Receiver has been freed.
+//
+// This is a convenient way to exit a goroutine sending values when
+// the receiver stops reading them.
+func Ranger[Elem any]() (*Sender[Elem], *Receiver[Elem]) {
+	c := make(chan Elem)
+	d := make(chan struct{})
+	s := &Sender[Elem]{
+		values: c,
+		done:   d,
+	}
+	r := &Receiver[Elem]{
+		values: c,
+		done:   d,
+	}
+	runtime.SetFinalizer(r, (*Receiver[Elem]).finalize)
+	return s, r
+}
+
+// A Sender is used to send values to a Receiver.
+type Sender[Elem any] struct {
+	values chan<- Elem
+	done   <-chan struct{}
+}
+
+// Send sends a value to the receiver. It reports whether the value was sent.
+// The value will not be sent if the context is closed or the receiver
+// is freed.
+func (s *Sender[Elem]) Send(ctx context.Context, v Elem) bool {
+	select {
+	case <-ctx.Done():
+		return false
+	case s.values <- v:
+		return true
+	case <-s.done:
+		return false
+	}
+}
+
+// Close tells the receiver that no more values will arrive.
+// After Close is called, the Sender may no longer be used.
+func (s *Sender[Elem]) Close() {
+	close(s.values)
+}
+
+// A Receiver receives values from a Sender.
+type Receiver[Elem any] struct {
+	values <-chan Elem
+	done   chan<- struct{}
+}
+
+// Next returns the next value from the channel. The bool result indicates
+// whether the value is valid.
+func (r *Receiver[Elem]) Next(ctx context.Context) (v Elem, ok bool) {
+	select {
+	case <-ctx.Done():
+	case v, ok = <-r.values:
+	}
+	return v, ok
+}
+
+// finalize is a finalizer for the receiver.
+func (r *Receiver[Elem]) finalize() {
+	close(r.done)
+}
diff --git a/test/typeparam/chansimp.dir/main.go b/test/typeparam/chansimp.dir/main.go
new file mode 100644
index 00000000000..ca271675982
--- /dev/null
+++ b/test/typeparam/chansimp.dir/main.go
@@ -0,0 +1,189 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"context"
+	"fmt"
+	"runtime"
+	"sort"
+	"sync"
+	"time"
+)
+
+func TestReadAll() {
+	c := make(chan int)
+	go func() {
+		c <- 4
+		c <- 2
+		c <- 5
+		close(c)
+	}()
+	got := a.ReadAll(context.Background(), c)
+	want := []int{4, 2, 5}
+	if !a.SliceEqual(got, want) {
+		panic(fmt.Sprintf("ReadAll returned %v, want %v", got, want))
+	}
+}
+
+func TestMerge() {
+	c1 := make(chan int)
+	c2 := make(chan int)
+	go func() {
+		c1 <- 1
+		c1 <- 3
+		c1 <- 5
+		close(c1)
+	}()
+	go func() {
+		c2 <- 2
+		c2 <- 4
+		c2 <- 6
+		close(c2)
+	}()
+	ctx := context.Background()
+	got := a.ReadAll(ctx, a.Merge(ctx, c1, c2))
+	sort.Ints(got)
+	want := []int{1, 2, 3, 4, 5, 6}
+	if !a.SliceEqual(got, want) {
+		panic(fmt.Sprintf("Merge returned %v, want %v", got, want))
+	}
+}
+
+func TestFilter() {
+	c := make(chan int)
+	go func() {
+		c <- 1
+		c <- 2
+		c <- 3
+		close(c)
+	}()
+	even := func(i int) bool { return i%2 == 0 }
+	ctx := context.Background()
+	got := a.ReadAll(ctx, a.Filter(ctx, c, even))
+	want := []int{2}
+	if !a.SliceEqual(got, want) {
+		panic(fmt.Sprintf("Filter returned %v, want %v", got, want))
+	}
+}
+
+func TestSink() {
+	c := a.Sink[int](context.Background())
+	after := time.NewTimer(time.Minute)
+	defer after.Stop()
+	send := func(v int) {
+		select {
+		case c <- v:
+		case <-after.C:
+			panic("timed out sending to Sink")
+		}
+	}
+	send(1)
+	send(2)
+	send(3)
+	close(c)
+}
+
+func TestExclusive() {
+	val := 0
+	ex := a.MakeExclusive(&val)
+
+	var wg sync.WaitGroup
+	f := func() {
+		defer wg.Done()
+		for i := 0; i < 10; i++ {
+			p := ex.Acquire()
+			(*p)++
+			ex.Release(p)
+		}
+	}
+
+	wg.Add(2)
+	go f()
+	go f()
+
+	wg.Wait()
+	if val != 20 {
+		panic(fmt.Sprintf("after Acquire/Release loop got %d, want 20", val))
+	}
+}
+
+func TestExclusiveTry() {
+	s := ""
+	ex := a.MakeExclusive(&s)
+	p, ok := ex.TryAcquire()
+	if !ok {
+		panic("TryAcquire failed")
+	}
+	*p = "a"
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		_, ok := ex.TryAcquire()
+		if ok {
+			panic(fmt.Sprintf("TryAcquire succeeded unexpectedly"))
+		}
+	}()
+	wg.Wait()
+
+	ex.Release(p)
+
+	p, ok = ex.TryAcquire()
+	if !ok {
+		panic(fmt.Sprintf("TryAcquire failed"))
+	}
+}
+
+func TestRanger() {
+	s, r := a.Ranger[int]()
+
+	ctx := context.Background()
+	go func() {
+		// Receive one value then exit.
+		v, ok := r.Next(ctx)
+		if !ok {
+			panic(fmt.Sprintf("did not receive any values"))
+		} else if v != 1 {
+			panic(fmt.Sprintf("received %d, want 1", v))
+		}
+	}()
+
+	c1 := make(chan bool)
+	c2 := make(chan bool)
+	go func() {
+		defer close(c2)
+		if !s.Send(ctx, 1) {
+			panic(fmt.Sprintf("Send failed unexpectedly"))
+		}
+		close(c1)
+		if s.Send(ctx, 2) {
+			panic(fmt.Sprintf("Send succeeded unexpectedly"))
+		}
+	}()
+
+	<-c1
+
+	// Force a garbage collection to try to get the finalizers to run.
+	runtime.GC()
+
+	select {
+	case <-c2:
+	case <-time.After(time.Minute):
+		panic("Ranger Send should have failed, but timed out")
+	}
+}
+
+func main() {
+	TestReadAll()
+	TestMerge()
+	TestFilter()
+	TestSink()
+	TestExclusive()
+	TestExclusiveTry()
+	TestRanger()
+}
diff --git a/test/typeparam/chansimp.go b/test/typeparam/chansimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/chansimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/combine.go b/test/typeparam/combine.go
index d4a2988a7b0..5dfdb784425 100644
--- a/test/typeparam/combine.go
+++ b/test/typeparam/combine.go
@@ -10,56 +10,56 @@ import (
 	"fmt"
 )
 
-type _Gen[A any] func() (A, bool)
+type Gen[A any] func() (A, bool)
 
-func combine[T1, T2, T any](g1 _Gen[T1], g2 _Gen[T2], join func(T1, T2) T) _Gen[T] {
-    return func() (T, bool) {
-        var t T
-        t1, ok := g1()
-        if !ok {
-            return t, false
-        }
-        t2, ok := g2()
-        if !ok {
-            return t, false
-        }
-        return join(t1, t2), true
-    }
+func Combine[T1, T2, T any](g1 Gen[T1], g2 Gen[T2], join func(T1, T2) T) Gen[T] {
+	return func() (T, bool) {
+		var t T
+		t1, ok := g1()
+		if !ok {
+			return t, false
+		}
+		t2, ok := g2()
+		if !ok {
+			return t, false
+		}
+		return join(t1, t2), true
+	}
 }
 
-type _Pair[A, B any] struct {
+type Pair[A, B any] struct {
 	A A
 	B B
 }
 
-func _NewPair[A, B any](a A, b B) _Pair[A, B] {
-	return _Pair[A, B]{a, b}
+func _NewPair[A, B any](a A, b B) Pair[A, B] {
+	return Pair[A, B]{a, b}
 }
 
-func _Combine2[A, B any](ga _Gen[A], gb _Gen[B]) _Gen[_Pair[A, B]] {
-    return combine(ga, gb, _NewPair[A, B])
+func Combine2[A, B any](ga Gen[A], gb Gen[B]) Gen[Pair[A, B]] {
+	return Combine(ga, gb, _NewPair[A, B])
 }
 
 func main() {
-	var g1 _Gen[int] = func() (int, bool) { return 3, true }
-	var g2 _Gen[string] = func() (string, bool) { return "x", false }
-	var g3 _Gen[string] = func() (string, bool) { return "y", true }
+	var g1 Gen[int] = func() (int, bool) { return 3, true }
+	var g2 Gen[string] = func() (string, bool) { return "x", false }
+	var g3 Gen[string] = func() (string, bool) { return "y", true }
 
-	gc := combine(g1, g2, _NewPair[int, string])
+	gc := Combine(g1, g2, _NewPair[int, string])
 	if got, ok := gc(); ok {
 		panic(fmt.Sprintf("got %v, %v, wanted -/false", got, ok))
 	}
-	gc2 := _Combine2(g1, g2)
+	gc2 := Combine2(g1, g2)
 	if got, ok := gc2(); ok {
 		panic(fmt.Sprintf("got %v, %v, wanted -/false", got, ok))
 	}
 
-	gc3 := combine(g1, g3, _NewPair[int, string])
+	gc3 := Combine(g1, g3, _NewPair[int, string])
 	if got, ok := gc3(); !ok || got.A != 3 || got.B != "y" {
 		panic(fmt.Sprintf("got %v, %v, wanted {3, y}, true", got, ok))
 	}
-	gc4 := _Combine2(g1, g3)
+	gc4 := Combine2(g1, g3)
 	if got, ok := gc4(); !ok || got.A != 3 || got.B != "y" {
-		panic (fmt.Sprintf("got %v, %v, wanted {3, y}, true", got, ok))
+		panic(fmt.Sprintf("got %v, %v, wanted {3, y}, true", got, ok))
 	}
 }
diff --git a/test/typeparam/cons.go b/test/typeparam/cons.go
index 8d255ebdb83..4750392a955 100644
--- a/test/typeparam/cons.go
+++ b/test/typeparam/cons.go
@@ -12,7 +12,7 @@ import "fmt"
 // argument
 type any interface{}
 
-type _Function[a, b any] interface {
+type Function[a, b any] interface {
 	Apply(x a) b
 }
 
@@ -29,8 +29,8 @@ func (this pos) Apply(x int) bool {
 }
 
 type compose[a, b, c any] struct {
-	f _Function[a, b]
-	g _Function[b, c]
+	f Function[a, b]
+	g Function[b, c]
 }
 
 func (this compose[a, b, c]) Apply(x a) c {
@@ -47,52 +47,52 @@ func (this Int) Equal(that int) bool {
 	return int(this) == that
 }
 
-type _List[a any] interface {
-	Match(casenil _Function[_Nil[a], any], casecons _Function[_Cons[a], any]) any
+type List[a any] interface {
+	Match(casenil Function[Nil[a], any], casecons Function[Cons[a], any]) any
 }
 
-type _Nil[a any] struct{
+type Nil[a any] struct {
 }
 
-func (xs _Nil[a]) Match(casenil _Function[_Nil[a], any], casecons _Function[_Cons[a], any]) any {
+func (xs Nil[a]) Match(casenil Function[Nil[a], any], casecons Function[Cons[a], any]) any {
 	return casenil.Apply(xs)
 }
 
-type _Cons[a any] struct {
+type Cons[a any] struct {
 	Head a
-	Tail _List[a]
+	Tail List[a]
 }
 
-func (xs _Cons[a]) Match(casenil _Function[_Nil[a], any], casecons _Function[_Cons[a], any]) any {
+func (xs Cons[a]) Match(casenil Function[Nil[a], any], casecons Function[Cons[a], any]) any {
 	return casecons.Apply(xs)
 }
 
-type mapNil[a, b any] struct{
+type mapNil[a, b any] struct {
 }
 
-func (m mapNil[a, b]) Apply(_ _Nil[a]) any {
-	return _Nil[b]{}
+func (m mapNil[a, b]) Apply(_ Nil[a]) any {
+	return Nil[b]{}
 }
 
 type mapCons[a, b any] struct {
-	f _Function[a, b]
+	f Function[a, b]
 }
 
-func (m mapCons[a, b]) Apply(xs _Cons[a]) any {
-	return _Cons[b]{m.f.Apply(xs.Head), _Map[a, b](m.f, xs.Tail)}
+func (m mapCons[a, b]) Apply(xs Cons[a]) any {
+	return Cons[b]{m.f.Apply(xs.Head), Map[a, b](m.f, xs.Tail)}
 }
 
-func _Map[a, b any](f _Function[a, b], xs _List[a]) _List[b] {
-	return xs.Match(mapNil[a, b]{}, mapCons[a, b]{f}).(_List[b])
+func Map[a, b any](f Function[a, b], xs List[a]) List[b] {
+	return xs.Match(mapNil[a, b]{}, mapCons[a, b]{f}).(List[b])
 }
 
 func main() {
-	var xs _List[int] = _Cons[int]{3, _Cons[int]{6, _Nil[int]{}}}
-	var ys _List[int] = _Map[int, int](incr{-5}, xs)
-	var xz _List[bool] = _Map[int, bool](pos{}, ys)
-	cs1 := xz.(_Cons[bool])
-	cs2 := cs1.Tail.(_Cons[bool])
-	_, ok := cs2.Tail.(_Nil[bool])
+	var xs List[int] = Cons[int]{3, Cons[int]{6, Nil[int]{}}}
+	var ys List[int] = Map[int, int](incr{-5}, xs)
+	var xz List[bool] = Map[int, bool](pos{}, ys)
+	cs1 := xz.(Cons[bool])
+	cs2 := cs1.Tail.(Cons[bool])
+	_, ok := cs2.Tail.(Nil[bool])
 	if cs1.Head != false || cs2.Head != true || !ok {
 		panic(fmt.Sprintf("got %v, %v, %v, expected false, true, true",
 			cs1.Head, cs2.Head, ok))
diff --git a/test/typeparam/dedup.dir/a.go b/test/typeparam/dedup.dir/a.go
new file mode 100644
index 00000000000..f5cb6dc7623
--- /dev/null
+++ b/test/typeparam/dedup.dir/a.go
@@ -0,0 +1,10 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+//go:noinline
+func F[T comparable](a, b T) bool {
+	return a == b
+}
diff --git a/test/typeparam/dedup.dir/b.go b/test/typeparam/dedup.dir/b.go
new file mode 100644
index 00000000000..ce037e2d8a3
--- /dev/null
+++ b/test/typeparam/dedup.dir/b.go
@@ -0,0 +1,14 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "a"
+
+func B() {
+	var x int64
+	println(a.F(&x, &x))
+	var y int32
+	println(a.F(&y, &y))
+}
diff --git a/test/typeparam/dedup.dir/c.go b/test/typeparam/dedup.dir/c.go
new file mode 100644
index 00000000000..11a5d97642b
--- /dev/null
+++ b/test/typeparam/dedup.dir/c.go
@@ -0,0 +1,14 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package c
+
+import "a"
+
+func C() {
+	var x int64
+	println(a.F(&x, &x))
+	var y int32
+	println(a.F(&y, &y))
+}
diff --git a/test/typeparam/dedup.dir/main.go b/test/typeparam/dedup.dir/main.go
new file mode 100644
index 00000000000..dc3ff6f75ff
--- /dev/null
+++ b/test/typeparam/dedup.dir/main.go
@@ -0,0 +1,15 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"b"
+	"c"
+)
+
+func main() {
+	b.B()
+	c.C()
+}
diff --git a/test/typeparam/dedup.go b/test/typeparam/dedup.go
new file mode 100644
index 00000000000..dca4cf3a84f
--- /dev/null
+++ b/test/typeparam/dedup.go
@@ -0,0 +1,12 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Note: this doesn't really test the deduplication of
+// instantiations. It just provides an easy mechanism to build a
+// binary that you can then check with objdump manually to make sure
+// deduplication is happening. TODO: automate this somehow?
+
+package ignored
diff --git a/test/typeparam/dedup.out b/test/typeparam/dedup.out
new file mode 100644
index 00000000000..1140ff52e2b
--- /dev/null
+++ b/test/typeparam/dedup.out
@@ -0,0 +1,4 @@
+true
+true
+true
+true
diff --git a/test/typeparam/dictionaryCapture-noinline.go b/test/typeparam/dictionaryCapture-noinline.go
new file mode 100644
index 00000000000..ad5bfa008e9
--- /dev/null
+++ b/test/typeparam/dictionaryCapture-noinline.go
@@ -0,0 +1,126 @@
+// run -gcflags="-G=3 -l"
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test situations where functions/methods are not
+// immediately called and we need to capture the dictionary
+// required for later invocation.
+
+package main
+
+func main() {
+	functions()
+	methodExpressions()
+	methodValues()
+	interfaceMethods()
+	globals()
+}
+
+func g0[T any](x T) {
+}
+func g1[T any](x T) T {
+	return x
+}
+func g2[T any](x T) (T, T) {
+	return x, x
+}
+
+func functions() {
+	f0 := g0[int]
+	f0(7)
+	f1 := g1[int]
+	is7(f1(7))
+	f2 := g2[int]
+	is77(f2(7))
+}
+
+func is7(x int) {
+	if x != 7 {
+		println(x)
+		panic("assertion failed")
+	}
+}
+func is77(x, y int) {
+	if x != 7 || y != 7 {
+		println(x, y)
+		panic("assertion failed")
+	}
+}
+
+type s[T any] struct {
+	a T
+}
+
+func (x s[T]) g0() {
+}
+func (x s[T]) g1() T {
+	return x.a
+}
+func (x s[T]) g2() (T, T) {
+	return x.a, x.a
+}
+
+func methodExpressions() {
+	x := s[int]{a: 7}
+	f0 := s[int].g0
+	f0(x)
+	f1 := s[int].g1
+	is7(f1(x))
+	f2 := s[int].g2
+	is77(f2(x))
+}
+
+func methodValues() {
+	x := s[int]{a: 7}
+	f0 := x.g0
+	f0()
+	f1 := x.g1
+	is7(f1())
+	f2 := x.g2
+	is77(f2())
+}
+
+var x interface {
+	g0()
+	g1() int
+	g2() (int, int)
+} = s[int]{a: 7}
+var y interface{} = s[int]{a: 7}
+
+func interfaceMethods() {
+	x.g0()
+	is7(x.g1())
+	is77(x.g2())
+	y.(interface{ g0() }).g0()
+	is7(y.(interface{ g1() int }).g1())
+	is77(y.(interface{ g2() (int, int) }).g2())
+}
+
+// Also check for instantiations outside functions.
+var gg0 = g0[int]
+var gg1 = g1[int]
+var gg2 = g2[int]
+
+var hh0 = s[int].g0
+var hh1 = s[int].g1
+var hh2 = s[int].g2
+
+var xtop = s[int]{a: 7}
+var ii0 = x.g0
+var ii1 = x.g1
+var ii2 = x.g2
+
+func globals() {
+	gg0(7)
+	is7(gg1(7))
+	is77(gg2(7))
+	x := s[int]{a: 7}
+	hh0(x)
+	is7(hh1(x))
+	is77(hh2(x))
+	ii0()
+	is7(ii1())
+	is77(ii2())
+}
diff --git a/test/typeparam/dictionaryCapture.go b/test/typeparam/dictionaryCapture.go
new file mode 100644
index 00000000000..7c7948145a8
--- /dev/null
+++ b/test/typeparam/dictionaryCapture.go
@@ -0,0 +1,203 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test situations where functions/methods are not
+// immediately called and we need to capture the dictionary
+// required for later invocation.
+
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	functions()
+	methodExpressions()
+	genMethodExpressions[int](7)
+	methodValues()
+	genMethodValues[int](7)
+	interfaceMethods()
+	globals()
+	recursive()
+}
+
+func g0[T any](x T) {
+}
+func g1[T any](x T) T {
+	return x
+}
+func g2[T any](x T) (T, T) {
+	return x, x
+}
+
+func functions() {
+	f0 := g0[int]
+	f0(7)
+	f1 := g1[int]
+	is7(f1(7))
+	f2 := g2[int]
+	is77(f2(7))
+}
+
+func is7(x int) {
+	if x != 7 {
+		println(x)
+		panic("assertion failed")
+	}
+}
+func is77(x, y int) {
+	if x != 7 || y != 7 {
+		println(x, y)
+		panic("assertion failed")
+	}
+}
+
+type s[T any] struct {
+	a T
+}
+
+func (x s[T]) g0() {
+}
+func (x s[T]) g1() T {
+	return x.a
+}
+func (x s[T]) g2() (T, T) {
+	return x.a, x.a
+}
+
+func methodExpressions() {
+	x := s[int]{a: 7}
+	f0 := s[int].g0
+	f0(x)
+	f0p := (*s[int]).g0
+	f0p(&x)
+	f1 := s[int].g1
+	is7(f1(x))
+	f1p := (*s[int]).g1
+	is7(f1p(&x))
+	f2 := s[int].g2
+	is77(f2(x))
+	f2p := (*s[int]).g2
+	is77(f2p(&x))
+}
+
+func genMethodExpressions[T comparable](want T) {
+	x := s[T]{a: want}
+	f0 := s[T].g0
+	f0(x)
+	f0p := (*s[T]).g0
+	f0p(&x)
+	f1 := s[T].g1
+	if got := f1(x); got != want {
+		panic(fmt.Sprintf("f1(x) == %d, want %d", got, want))
+	}
+	f1p := (*s[T]).g1
+	if got := f1p(&x); got != want {
+		panic(fmt.Sprintf("f1p(&x) == %d, want %d", got, want))
+	}
+	f2 := s[T].g2
+	if got1, got2 := f2(x); got1 != want || got2 != want {
+		panic(fmt.Sprintf("f2(x) == %d, %d, want %d, %d", got1, got2, want, want))
+	}
+}
+
+func methodValues() {
+	x := s[int]{a: 7}
+	f0 := x.g0
+	f0()
+	f1 := x.g1
+	is7(f1())
+	f2 := x.g2
+	is77(f2())
+}
+
+func genMethodValues[T comparable](want T) {
+	x := s[T]{a: want}
+	f0 := x.g0
+	f0()
+	f1 := x.g1
+	if got := f1(); got != want {
+		panic(fmt.Sprintf("f1() == %d, want %d", got, want))
+	}
+	f2 := x.g2
+	if got1, got2 := f2(); got1 != want || got2 != want {
+		panic(fmt.Sprintf("f2() == %d, %d, want %d, %d", got1, got2, want, want))
+	}
+}
+
+var x interface {
+	g0()
+	g1() int
+	g2() (int, int)
+} = s[int]{a: 7}
+var y interface{} = s[int]{a: 7}
+
+func interfaceMethods() {
+	x.g0()
+	is7(x.g1())
+	is77(x.g2())
+	y.(interface{ g0() }).g0()
+	is7(y.(interface{ g1() int }).g1())
+	is77(y.(interface{ g2() (int, int) }).g2())
+}
+
+// Also check for instantiations outside functions.
+var gg0 = g0[int]
+var gg1 = g1[int]
+var gg2 = g2[int]
+
+var hh0 = s[int].g0
+var hh1 = s[int].g1
+var hh2 = s[int].g2
+
+var xtop = s[int]{a: 7}
+var ii0 = x.g0
+var ii1 = x.g1
+var ii2 = x.g2
+
+func globals() {
+	gg0(7)
+	is7(gg1(7))
+	is77(gg2(7))
+	x := s[int]{a: 7}
+	hh0(x)
+	is7(hh1(x))
+	is77(hh2(x))
+	ii0()
+	is7(ii1())
+	is77(ii2())
+}
+
+func recursive() {
+	if got, want := recur1[int](5), 110; got != want {
+		panic(fmt.Sprintf("recur1[int](5) = %d, want = %d", got, want))
+	}
+}
+
+type Integer interface {
+	int | int32 | int64
+}
+
+func recur1[T Integer](n T) T {
+	if n == 0 || n == 1 {
+		return T(1)
+	} else {
+		return n * recur2(n-1)
+	}
+}
+
+func recur2[T Integer](n T) T {
+	list := make([]T, n)
+	for i, _ := range list {
+		list[i] = T(i + 1)
+	}
+	var sum T
+	for _, elt := range list {
+		sum += elt
+	}
+	return sum + recur1(n-1)
+}
diff --git a/test/typeparam/dottype.go b/test/typeparam/dottype.go
new file mode 100644
index 00000000000..c9c900c0962
--- /dev/null
+++ b/test/typeparam/dottype.go
@@ -0,0 +1,86 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f[T any](x interface{}) T {
+	return x.(T)
+}
+func f2[T any](x interface{}) (T, bool) {
+	t, ok := x.(T)
+	return t, ok
+}
+
+type I interface {
+	foo()
+}
+
+type myint int
+
+func (myint) foo() {
+}
+
+type myfloat float64
+
+func (myfloat) foo() {
+}
+
+func g[T I](x I) T {
+	return x.(T)
+}
+func g2[T I](x I) (T, bool) {
+	t, ok := x.(T)
+	return t, ok
+}
+
+func h[T any](x interface{}) struct{ a, b T } {
+	return x.(struct{ a, b T })
+}
+
+func k[T any](x interface{}) interface{ bar() T } {
+	return x.(interface{ bar() T })
+}
+
+type mybar int
+
+func (x mybar) bar() int {
+	return int(x)
+}
+
+func main() {
+	var i interface{} = int(3)
+	var j I = myint(3)
+	var x interface{} = float64(3)
+	var y I = myfloat(3)
+
+	println(f[int](i))
+	shouldpanic(func() { f[int](x) })
+	println(f2[int](i))
+	println(f2[int](x))
+
+	println(g[myint](j))
+	shouldpanic(func() { g[myint](y) })
+	println(g2[myint](j))
+	println(g2[myint](y))
+
+	println(h[int](struct{ a, b int }{3, 5}).a)
+
+	println(k[int](mybar(3)).bar())
+
+	type large struct {a,b,c,d,e,f int}
+	println(f[large](large{}).a)
+	l2, ok := f2[large](large{})
+	println(l2.a, ok)
+}
+func shouldpanic(x func()) {
+	defer func() {
+		e := recover()
+		if e == nil {
+			panic("didn't panic")
+		}
+	}()
+	x()
+}
diff --git a/test/typeparam/dottype.out b/test/typeparam/dottype.out
new file mode 100644
index 00000000000..8e6a3c25526
--- /dev/null
+++ b/test/typeparam/dottype.out
@@ -0,0 +1,10 @@
+3
+3 true
+0 false
+3
+3 true
+0 false
+3
+3
+0
+0 true
diff --git a/test/typeparam/double.go b/test/typeparam/double.go
index ce78ec97483..6ddb6b2d08b 100644
--- a/test/typeparam/double.go
+++ b/test/typeparam/double.go
@@ -12,7 +12,7 @@ import (
 )
 
 type Number interface {
-	type int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, uintptr, float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | ~float32 | ~float64
 }
 
 type MySlice []int
@@ -44,29 +44,29 @@ func main() {
 	want := MySlice{2, 4, 6}
 	got := _DoubleElems[MySlice, int](arg)
 	if !reflect.DeepEqual(got, want) {
-                panic(fmt.Sprintf("got %s, want %s", got, want))
+		panic(fmt.Sprintf("got %s, want %s", got, want))
 	}
 
 	// constraint type inference
 	got = _DoubleElems[MySlice](arg)
 	if !reflect.DeepEqual(got, want) {
-                panic(fmt.Sprintf("got %s, want %s", got, want))
+		panic(fmt.Sprintf("got %s, want %s", got, want))
 	}
 
 	got = _DoubleElems(arg)
 	if !reflect.DeepEqual(got, want) {
-                panic(fmt.Sprintf("got %s, want %s", got, want))
+		panic(fmt.Sprintf("got %s, want %s", got, want))
 	}
 
 	farg := MyFloatSlice{1.2, 2.0, 3.5}
 	fwant := MyFloatSlice{2.4, 4.0, 7.0}
 	fgot := _DoubleElems(farg)
 	if !reflect.DeepEqual(fgot, fwant) {
-                panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
+		panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
 	}
 
 	fgot = _DoubleElems2(farg)
 	if !reflect.DeepEqual(fgot, fwant) {
-                panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
+		panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
 	}
 }
diff --git a/test/typeparam/equal.go b/test/typeparam/equal.go
new file mode 100644
index 00000000000..a1d3e8ae023
--- /dev/null
+++ b/test/typeparam/equal.go
@@ -0,0 +1,69 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// comparisons of type parameters to interfaces
+
+package main
+
+func f[T comparable](t, u T) bool {
+	// Comparing two type parameters directly.
+	// (Not really testing comparisons to interfaces, but just 'cause we're here.)
+	return t == u
+}
+
+func g[T comparable](t T, i interface{}) bool {
+	// Compare type parameter value to empty interface.
+	return t == i
+}
+
+type I interface {
+	foo()
+}
+
+type C interface {
+	comparable
+	I
+}
+
+func h[T C](t T, i I) bool {
+	// Compare type parameter value to nonempty interface.
+	return t == i
+}
+
+type myint int
+
+func (x myint) foo() {
+}
+
+func k[T comparable](t T, i interface{}) bool {
+	// Compare derived type value to interface.
+	return struct{ a, b T }{t, t} == i
+}
+
+func main() {
+	assert(f(3, 3))
+	assert(!f(3, 5))
+	assert(g(3, 3))
+	assert(!g(3, 5))
+	assert(h(myint(3), myint(3)))
+	assert(!h(myint(3), myint(5)))
+
+	type S struct{ a, b float64 }
+
+	assert(f(S{3, 5}, S{3, 5}))
+	assert(!f(S{3, 5}, S{4, 6}))
+	assert(g(S{3, 5}, S{3, 5}))
+	assert(!g(S{3, 5}, S{4, 6}))
+
+	assert(k(3, struct{ a, b int }{3, 3}))
+	assert(!k(3, struct{ a, b int }{3, 4}))
+}
+
+func assert(b bool) {
+	if !b {
+		panic("assertion failed")
+	}
+}
diff --git a/test/typeparam/fact.go b/test/typeparam/fact.go
index 16b2adf6fb7..e19cfe69565 100644
--- a/test/typeparam/fact.go
+++ b/test/typeparam/fact.go
@@ -8,11 +8,11 @@ package main
 
 import "fmt"
 
-func fact[T interface { type int, int64, float64 }](n T) T {
-	if n == T(1) {
-		return T(1)
+func fact[T interface{ ~int | ~int64 | ~float64 }](n T) T {
+	if n == 1 {
+		return 1
 	}
-	return n * fact(n - T(1))
+	return n * fact(n-1)
 }
 
 func main() {
diff --git a/test/typeparam/factimp.dir/a.go b/test/typeparam/factimp.dir/a.go
new file mode 100644
index 00000000000..0bd73a88e7d
--- /dev/null
+++ b/test/typeparam/factimp.dir/a.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func Fact[T interface{ int | int64 | float64 }](n T) T {
+	if n == 1 {
+		return 1
+	}
+	return n * Fact(n-1)
+}
diff --git a/test/typeparam/factimp.dir/main.go b/test/typeparam/factimp.dir/main.go
new file mode 100644
index 00000000000..c2238002aeb
--- /dev/null
+++ b/test/typeparam/factimp.dir/main.go
@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	const want = 120
+
+	if got := a.Fact(5); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Fact[int64](5); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Fact(5.0); got != want {
+		panic(fmt.Sprintf("got %f, want %f", got, want))
+	}
+}
diff --git a/test/typeparam/factimp.go b/test/typeparam/factimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/factimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/graph.go b/test/typeparam/graph.go
index f2a2630ad09..cecf349a9ad 100644
--- a/test/typeparam/graph.go
+++ b/test/typeparam/graph.go
@@ -225,7 +225,6 @@ func TestShortestPath() {
 	}
 }
 
-
 func main() {
 	TestShortestPath()
 }
diff --git a/test/typeparam/ifaceconv.go b/test/typeparam/ifaceconv.go
new file mode 100644
index 00000000000..ee3a9e0dc3a
--- /dev/null
+++ b/test/typeparam/ifaceconv.go
@@ -0,0 +1,83 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that we can convert type parameters to both empty
+// and nonempty interfaces, and named and nonnamed versions
+// thereof.
+
+package main
+
+import "fmt"
+
+type E interface{}
+
+func f[T any](x T) interface{} {
+	var i interface{} = x
+	return i
+}
+
+func fs[T any](x T) interface{} {
+	y := []T{x}
+	var i interface{} = y
+	return i
+}
+
+func g[T any](x T) E {
+	var i E = x
+	return i
+}
+
+type C interface {
+	foo() int
+}
+
+type myInt int
+
+func (x myInt) foo() int {
+	return int(x + 1)
+}
+
+func h[T C](x T) interface{ foo() int } {
+	var i interface{ foo() int } = x
+	return i
+}
+func i[T C](x T) C {
+	var i C = x // conversion in assignment
+	return i
+}
+
+func j[T C](t T) C {
+	return C(t) // explicit conversion
+}
+
+func js[T any](x T) interface{} {
+	y := []T{x}
+	return interface{}(y)
+}
+
+func main() {
+	if got, want := f[int](7), 7; got != want {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := fs[int](7), []int{7}; got.([]int)[0] != want[0] {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := g[int](7), 7; got != want {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := h[myInt](7).foo(), 8; got != want {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := i[myInt](7).foo(), 8; got != want {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := j[myInt](7).foo(), 8; got != want {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+	if got, want := js[int](7), []int{7}; got.([]int)[0] != want[0] {
+		panic(fmt.Sprintf("got %d want %d", got, want))
+	}
+}
diff --git a/test/typeparam/index.go b/test/typeparam/index.go
index 83e65acdd00..906f76d325c 100644
--- a/test/typeparam/index.go
+++ b/test/typeparam/index.go
@@ -11,7 +11,7 @@ import (
 )
 
 // Index returns the index of x in s, or -1 if not found.
-func index[T comparable](s []T, x T) int {
+func Index[T comparable](s []T, x T) int {
 	for i, v := range s {
 		// v and x are type T, which has the comparable
 		// constraint, so we can use == here.
@@ -26,21 +26,56 @@ type obj struct {
 	x int
 }
 
+type obj2 struct {
+	x int8
+	y float64
+}
+
+type obj3 struct {
+	x int64
+	y int8
+}
+
+type inner struct {
+	y int64
+	z int32
+}
+
+type obj4 struct {
+	x int32
+	s inner
+}
+
 func main() {
 	want := 2
 
 	vec1 := []string{"ab", "cd", "ef"}
-	if got := index(vec1, "ef"); got != want {
+	if got := Index(vec1, "ef"); got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 
 	vec2 := []byte{'c', '6', '@'}
-	if got := index(vec2, '@'); got != want {
+	if got := Index(vec2, '@'); got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 
 	vec3 := []*obj{&obj{2}, &obj{42}, &obj{1}}
-	if got := index(vec3, vec3[2]); got != want {
+	if got := Index(vec3, vec3[2]); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	vec4 := []obj2{obj2{2, 3.0}, obj2{3, 4.0}, obj2{4, 5.0}}
+	if got := Index(vec4, vec4[2]); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	vec5 := []obj3{obj3{2, 3}, obj3{3, 4}, obj3{4, 5}}
+	if got := Index(vec5, vec5[2]); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	vec6 := []obj4{obj4{2, inner{3, 4}}, obj4{3, inner{4, 5}}, obj4{4, inner{5, 6}}}
+	if got := Index(vec6, vec6[2]); got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 }
diff --git a/test/typeparam/interfacearg.go b/test/typeparam/interfacearg.go
index e2d85e3647b..28ea3e3afbb 100644
--- a/test/typeparam/interfacearg.go
+++ b/test/typeparam/interfacearg.go
@@ -9,23 +9,25 @@ package main
 type I interface{}
 
 type _S[T any] struct {
-	*T
+	x *T
 }
 
 // F is a non-generic function, but has a type _S[I] which is instantiated from a
 // generic type. Test that _S[I] is successfully exported.
 func F() {
 	v := _S[I]{}
-	if v.T != nil {
+	if v.x != nil {
 		panic(v)
 	}
 }
 
 // Testing the various combinations of method expressions.
 type S1 struct{}
+
 func (*S1) M() {}
 
 type S2 struct{}
+
 func (S2) M() {}
 
 func _F1[T interface{ M() }](t T) {
@@ -33,9 +35,9 @@ func _F1[T interface{ M() }](t T) {
 }
 
 func F2() {
-        _F1(&S1{})
-        _F1(S2{})
-        _F1(&S2{})
+	_F1(&S1{})
+	_F1(S2{})
+	_F1(&S2{})
 }
 
 func main() {
diff --git a/test/typeparam/issue39755.go b/test/typeparam/issue39755.go
new file mode 100644
index 00000000000..c4b6902eead
--- /dev/null
+++ b/test/typeparam/issue39755.go
@@ -0,0 +1,27 @@
+// compile -G=3
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// copied from cmd/compile/internal/types2/testdata/fixedbugs/issue39755.go
+
+package p
+
+func _[T interface{ ~map[string]int }](x T) {
+	_ = x == nil
+}
+
+// simplified test case from issue
+
+type PathParamsConstraint interface {
+	~map[string]string | ~[]struct{ key, value string }
+}
+
+type PathParams[T PathParamsConstraint] struct {
+	t T
+}
+
+func (pp *PathParams[T]) IsNil() bool {
+	return pp.t == nil // this must succeed
+}
diff --git a/test/typeparam/issue44688.go b/test/typeparam/issue44688.go
new file mode 100644
index 00000000000..5ebce72628f
--- /dev/null
+++ b/test/typeparam/issue44688.go
@@ -0,0 +1,148 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// derived & expanded from cmd/compile/internal/types2/testdata/fixedbugs/issue44688.go2
+
+package main
+
+type A1[T any] struct {
+	val T
+}
+
+func (p *A1[T]) m1(val T) {
+	p.val = val
+}
+
+type A2[T any] interface {
+	m2(T)
+}
+
+type B1[T any] struct {
+	filler int
+	*A1[T]
+	A2[T]
+}
+
+type B2[T any] interface {
+	A2[T]
+}
+
+type ImpA2[T any] struct {
+	f T
+}
+
+func (a2 *ImpA2[T]) m2(s T) {
+	a2.f = s
+}
+
+type C[T any] struct {
+	filler1 int
+	filler2 int
+	B1[T]
+}
+
+type D[T any] struct {
+	filler1 int
+	filler2 int
+	filler3 int
+	C[T]
+}
+
+func test1[T any](arg T) {
+	// calling embedded methods
+	var b1 B1[T]
+	b1.A1 = &A1[T]{}
+	b1.A2 = &ImpA2[T]{}
+
+	b1.A1.m1(arg)
+	b1.m1(arg)
+
+	b1.A2.m2(arg)
+	b1.m2(arg)
+
+	var b2 B2[T]
+	b2 = &ImpA2[T]{}
+	b2.m2(arg)
+
+	// a deeper nesting
+	var d D[T]
+	d.C.B1.A1 = &A1[T]{}
+	d.C.B1.A2 = &ImpA2[T]{}
+	d.m1(arg)
+	d.m2(arg)
+
+	// calling method expressions
+	m1x := B1[T].m1
+	m1x(b1, arg)
+	m2x := B2[T].m2
+	m2x(b2, arg)
+
+	// calling method values
+	m1v := b1.m1
+	m1v(arg)
+	m2v := b1.m2
+	m2v(arg)
+	b2v := b2.m2
+	b2v(arg)
+}
+
+func test2() {
+	// calling embedded methods
+	var b1 B1[string]
+	b1.A1 = &A1[string]{}
+	b1.A2 = &ImpA2[string]{}
+
+	b1.A1.m1("")
+	b1.m1("")
+
+	b1.A2.m2("")
+	b1.m2("")
+
+	var b2 B2[string]
+	b2 = &ImpA2[string]{}
+	b2.m2("")
+
+	// a deeper nesting
+	var d D[string]
+	d.C.B1.A1 = &A1[string]{}
+	d.C.B1.A2 = &ImpA2[string]{}
+	d.m1("")
+	d.m2("")
+
+	// calling method expressions
+	m1x := B1[string].m1
+	m1x(b1, "")
+	m2x := B2[string].m2
+	m2x(b2, "")
+
+	// calling method values
+	m1v := b1.m1
+	m1v("")
+	m2v := b1.m2
+	m2v("")
+	b2v := b2.m2
+	b2v("")
+}
+
+// actual test case from issue
+
+type A[T any] struct{}
+
+func (*A[T]) f(T) {}
+
+type B[T any] struct{ A[T] }
+
+func test3() {
+	var b B[string]
+	b.A.f("")
+	b.f("")
+}
+
+func main() {
+	test1[string]("")
+	test2()
+	test3()
+}
diff --git a/test/typeparam/issue45547.go b/test/typeparam/issue45547.go
index 0a08d66b70e..b354d4d7f64 100644
--- a/test/typeparam/issue45547.go
+++ b/test/typeparam/issue45547.go
@@ -11,7 +11,7 @@ func f[T any]() (f, g T) { return f, g }
 // Tests for generic function instantiation on the right hande side of multi-value
 // assignments.
 
-func _() {
+func g() {
 	// Multi-value assignment within a function
 	var _, _ = f[int]()
 }
diff --git a/test/typeparam/issue45817.go b/test/typeparam/issue45817.go
new file mode 100644
index 00000000000..1efee3b0af2
--- /dev/null
+++ b/test/typeparam/issue45817.go
@@ -0,0 +1,26 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+)
+
+type s[T any] struct {
+	a T
+}
+
+func (x s[T]) f() T {
+	return x.a
+}
+func main() {
+	x := s[int]{a: 7}
+	f := x.f
+	if got, want := f(), 7; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+}
diff --git a/test/typeparam/issue46472.go b/test/typeparam/issue46472.go
new file mode 100644
index 00000000000..cd4d923ef55
--- /dev/null
+++ b/test/typeparam/issue46472.go
@@ -0,0 +1,20 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func foo[T any](d T) {
+	switch v := interface{}(d).(type) {
+	case string:
+		if v != "x" {
+			panic("unexpected v: " + v)
+		}
+	}
+
+}
+func main() {
+	foo("x")
+}
diff --git a/test/typeparam/issue47258.go b/test/typeparam/issue47258.go
new file mode 100644
index 00000000000..717329471e1
--- /dev/null
+++ b/test/typeparam/issue47258.go
@@ -0,0 +1,32 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+)
+
+type Numeric interface {
+	int32 | int64 | float64 | complex64
+}
+
+//go:noline
+func inc[T Numeric](x T) T {
+	x++
+	return x
+}
+func main() {
+	if got, want := inc(int32(5)), int32(6); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+	if got, want := inc(float64(5)), float64(6.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+	if got, want := inc(complex64(5)), complex64(6.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+}
diff --git a/test/typeparam/issue47514.go b/test/typeparam/issue47514.go
new file mode 100644
index 00000000000..947f254003d
--- /dev/null
+++ b/test/typeparam/issue47514.go
@@ -0,0 +1,20 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that closures inside a generic function are not exported,
+// even though not themselves generic.
+
+package main
+
+func Do[T any]() {
+	_ = func() string {
+		return ""
+	}
+}
+
+func main() {
+	Do[int]()
+}
diff --git a/test/typeparam/issue47514b.go b/test/typeparam/issue47514b.go
new file mode 100644
index 00000000000..5428a0edc5f
--- /dev/null
+++ b/test/typeparam/issue47514b.go
@@ -0,0 +1,19 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func Do[T any](do func() (T, string)) {
+	_ = func() (T, string) {
+		return do()
+	}
+}
+
+func main() {
+	Do[int](func() (int, string) {
+		return 3, "3"
+	})
+}
diff --git a/test/typeparam/list.go b/test/typeparam/list.go
index 579078f02f7..adfe72f1de1 100644
--- a/test/typeparam/list.go
+++ b/test/typeparam/list.go
@@ -11,10 +11,10 @@ import (
 )
 
 type Ordered interface {
-        type int, int8, int16, int32, int64,
-                uint, uint8, uint16, uint32, uint64, uintptr,
-                float32, float64,
-                string
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
 }
 
 // _List is a linked list of ordered values of type T.
@@ -34,9 +34,9 @@ func (l *_List[T]) Largest() T {
 }
 
 type OrderedNum interface {
-        type int, int8, int16, int32, int64,
-                uint, uint8, uint16, uint32, uint64, uintptr,
-                float32, float64
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
 }
 
 // _ListNum is a linked _List of ordered numeric values of type T.
@@ -64,40 +64,40 @@ func main() {
 	i2 := &_List[int]{i3, 3}
 	i1 := &_List[int]{i2, 2}
 	if got, want := i1.Largest(), 3; got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 
 	b3 := &_List[byte]{nil, byte(1)}
 	b2 := &_List[byte]{b3, byte(3)}
 	b1 := &_List[byte]{b2, byte(2)}
 	if got, want := b1.Largest(), byte(3); got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 
 	f3 := &_List[float64]{nil, 13.5}
 	f2 := &_List[float64]{f3, 1.2}
 	f1 := &_List[float64]{f2, 4.5}
 	if got, want := f1.Largest(), 13.5; got != want {
-                panic(fmt.Sprintf("got %f, want %f", got, want))
+		panic(fmt.Sprintf("got %f, want %f", got, want))
 	}
 
 	s3 := &_List[string]{nil, "dd"}
 	s2 := &_List[string]{s3, "aa"}
 	s1 := &_List[string]{s2, "bb"}
 	if got, want := s1.Largest(), "dd"; got != want {
-                panic(fmt.Sprintf("got %s, want %s", got, want))
+		panic(fmt.Sprintf("got %s, want %s", got, want))
 	}
 
 	j3 := &_ListNum[int]{nil, 1}
 	j2 := &_ListNum[int]{j3, 32}
 	j1 := &_ListNum[int]{j2, 2}
 	if got, want := j1.ClippedLargest(), 2; got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 	g3 := &_ListNum[float64]{nil, 13.5}
 	g2 := &_ListNum[float64]{g3, 1.2}
 	g1 := &_ListNum[float64]{g2, 4.5}
 	if got, want := g1.ClippedLargest(), 4.5; got != want {
-                panic(fmt.Sprintf("got %f, want %f", got, want))
+		panic(fmt.Sprintf("got %f, want %f", got, want))
 	}
 }
diff --git a/test/typeparam/list2.go b/test/typeparam/list2.go
index 385193d8765..e7f346c78e1 100644
--- a/test/typeparam/list2.go
+++ b/test/typeparam/list2.go
@@ -50,7 +50,7 @@ func (e *_Element[T]) Prev() *_Element[T] {
 // The zero value for _List is an empty list ready to use.
 type _List[T any] struct {
 	root _Element[T] // sentinel list element, only &root, root.prev, and root.next are used
-	len  int     // current list length excluding (this) sentinel element
+	len  int         // current list length excluding (this) sentinel element
 }
 
 // Init initializes or clears list l.
@@ -594,8 +594,15 @@ func TestTransform() {
 	checkList(l2, []interface{}{"1", "2"})
 }
 
-
 func main() {
 	TestList()
+	TestExtending()
+	TestRemove()
+	TestIssue4103()
+	TestIssue6349()
+	TestMove()
+	TestZeroList()
+	TestInsertBeforeUnknownMark()
+	TestInsertAfterUnknownMark()
+	TestTransform()
 }
-
diff --git a/test/typeparam/listimp.dir/a.go b/test/typeparam/listimp.dir/a.go
new file mode 100644
index 00000000000..bf1641af9c3
--- /dev/null
+++ b/test/typeparam/listimp.dir/a.go
@@ -0,0 +1,53 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// List is a linked list of ordered values of type T.
+type List[T Ordered] struct {
+	Next *List[T]
+	Val  T
+}
+
+func (l *List[T]) Largest() T {
+	var max T
+	for p := l; p != nil; p = p.Next {
+		if p.Val > max {
+			max = p.Val
+		}
+	}
+	return max
+}
+
+type OrderedNum interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
+}
+
+// ListNum is a linked _List of ordered numeric values of type T.
+type ListNum[T OrderedNum] struct {
+	Next *ListNum[T]
+	Val  T
+}
+
+const Clip = 5
+
+// clippedLargest returns the largest in the list of OrderNums, but a max of 5.
+func (l *ListNum[T]) ClippedLargest() T {
+	var max T
+	for p := l; p != nil; p = p.Next {
+		if p.Val > max && p.Val < Clip {
+			max = p.Val
+		}
+	}
+	return max
+}
diff --git a/test/typeparam/listimp.dir/main.go b/test/typeparam/listimp.dir/main.go
new file mode 100644
index 00000000000..985ff59a189
--- /dev/null
+++ b/test/typeparam/listimp.dir/main.go
@@ -0,0 +1,52 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	i3 := &a.List[int]{nil, 1}
+	i2 := &a.List[int]{i3, 3}
+	i1 := &a.List[int]{i2, 2}
+	if got, want := i1.Largest(), 3; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	b3 := &a.List[byte]{nil, byte(1)}
+	b2 := &a.List[byte]{b3, byte(3)}
+	b1 := &a.List[byte]{b2, byte(2)}
+	if got, want := b1.Largest(), byte(3); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	f3 := &a.List[float64]{nil, 13.5}
+	f2 := &a.List[float64]{f3, 1.2}
+	f1 := &a.List[float64]{f2, 4.5}
+	if got, want := f1.Largest(), 13.5; got != want {
+		panic(fmt.Sprintf("got %f, want %f", got, want))
+	}
+
+	s3 := &a.List[string]{nil, "dd"}
+	s2 := &a.List[string]{s3, "aa"}
+	s1 := &a.List[string]{s2, "bb"}
+	if got, want := s1.Largest(), "dd"; got != want {
+		panic(fmt.Sprintf("got %s, want %s", got, want))
+	}
+	j3 := &a.ListNum[int]{nil, 1}
+	j2 := &a.ListNum[int]{j3, 32}
+	j1 := &a.ListNum[int]{j2, 2}
+	if got, want := j1.ClippedLargest(), 2; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+	g3 := &a.ListNum[float64]{nil, 13.5}
+	g2 := &a.ListNum[float64]{g3, 1.2}
+	g1 := &a.ListNum[float64]{g2, 4.5}
+	if got, want := g1.ClippedLargest(), 4.5; got != want {
+		panic(fmt.Sprintf("got %f, want %f", got, want))
+	}
+}
diff --git a/test/typeparam/listimp.go b/test/typeparam/listimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/listimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/listimp2.dir/a.go b/test/typeparam/listimp2.dir/a.go
new file mode 100644
index 00000000000..3a7dfc3999a
--- /dev/null
+++ b/test/typeparam/listimp2.dir/a.go
@@ -0,0 +1,298 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+import (
+	"fmt"
+)
+
+// Element is an element of a linked list.
+type Element[T any] struct {
+	// Next and previous pointers in the doubly-linked list of elements.
+	// To simplify the implementation, internally a list l is implemented
+	// as a ring, such that &l.root is both the next element of the last
+	// list element (l.Back()) and the previous element of the first list
+	// element (l.Front()).
+	next, prev *Element[T]
+
+	// The list to which this element belongs.
+	list *List[T]
+
+	// The value stored with this element.
+	Value T
+}
+
+// Next returns the next list element or nil.
+func (e *Element[T]) Next() *Element[T] {
+	if p := e.next; e.list != nil && p != &e.list.root {
+		return p
+	}
+	return nil
+}
+
+// Prev returns the previous list element or nil.
+func (e *Element[T]) Prev() *Element[T] {
+	if p := e.prev; e.list != nil && p != &e.list.root {
+		return p
+	}
+	return nil
+}
+
+// List represents a doubly linked list.
+// The zero value for List is an empty list ready to use.
+type List[T any] struct {
+	root Element[T] // sentinel list element, only &root, root.prev, and root.next are used
+	len  int        // current list length excluding (this) sentinel element
+}
+
+// Init initializes or clears list l.
+func (l *List[T]) Init() *List[T] {
+	l.root.next = &l.root
+	l.root.prev = &l.root
+	l.len = 0
+	return l
+}
+
+// New returns an initialized list.
+func New[T any]() *List[T] { return new(List[T]).Init() }
+
+// Len returns the number of elements of list l.
+// The complexity is O(1).
+func (l *List[_]) Len() int { return l.len }
+
+// Front returns the first element of list l or nil if the list is empty.
+func (l *List[T]) Front() *Element[T] {
+	if l.len == 0 {
+		return nil
+	}
+	return l.root.next
+}
+
+// Back returns the last element of list l or nil if the list is empty.
+func (l *List[T]) Back() *Element[T] {
+	if l.len == 0 {
+		return nil
+	}
+	return l.root.prev
+}
+
+// lazyInit lazily initializes a zero List value.
+func (l *List[_]) lazyInit() {
+	if l.root.next == nil {
+		l.Init()
+	}
+}
+
+// insert inserts e after at, increments l.len, and returns e.
+func (l *List[T]) insert(e, at *Element[T]) *Element[T] {
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+	e.list = l
+	l.len++
+	return e
+}
+
+// insertValue is a convenience wrapper for insert(&Element[T]{Value: v}, at).
+func (l *List[T]) insertValue(v T, at *Element[T]) *Element[T] {
+	return l.insert(&Element[T]{Value: v}, at)
+}
+
+// remove removes e from its list, decrements l.len, and returns e.
+func (l *List[T]) remove(e *Element[T]) *Element[T] {
+	e.prev.next = e.next
+	e.next.prev = e.prev
+	e.next = nil // avoid memory leaks
+	e.prev = nil // avoid memory leaks
+	e.list = nil
+	l.len--
+	return e
+}
+
+// move moves e to next to at and returns e.
+func (l *List[T]) move(e, at *Element[T]) *Element[T] {
+	if e == at {
+		return e
+	}
+	e.prev.next = e.next
+	e.next.prev = e.prev
+
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+
+	return e
+}
+
+// Remove removes e from l if e is an element of list l.
+// It returns the element value e.Value.
+// The element must not be nil.
+func (l *List[T]) Remove(e *Element[T]) T {
+	if e.list == l {
+		// if e.list == l, l must have been initialized when e was inserted
+		// in l or l == nil (e is a zero Element) and l.remove will crash
+		l.remove(e)
+	}
+	return e.Value
+}
+
+// PushFront inserts a new element e with value v at the front of list l and returns e.
+func (l *List[T]) PushFront(v T) *Element[T] {
+	l.lazyInit()
+	return l.insertValue(v, &l.root)
+}
+
+// PushBack inserts a new element e with value v at the back of list l and returns e.
+func (l *List[T]) PushBack(v T) *Element[T] {
+	l.lazyInit()
+	return l.insertValue(v, l.root.prev)
+}
+
+// InsertBefore inserts a new element e with value v immediately before mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertBefore(v T, mark *Element[T]) *Element[T] {
+	if mark.list != l {
+		return nil
+	}
+	// see comment in List.Remove about initialization of l
+	return l.insertValue(v, mark.prev)
+}
+
+// InsertAfter inserts a new element e with value v immediately after mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertAfter(v T, mark *Element[T]) *Element[T] {
+	if mark.list != l {
+		return nil
+	}
+	// see comment in List.Remove about initialization of l
+	return l.insertValue(v, mark)
+}
+
+// MoveToFront moves element e to the front of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToFront(e *Element[T]) {
+	if e.list != l || l.root.next == e {
+		return
+	}
+	// see comment in List.Remove about initialization of l
+	l.move(e, &l.root)
+}
+
+// MoveToBack moves element e to the back of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToBack(e *Element[T]) {
+	if e.list != l || l.root.prev == e {
+		return
+	}
+	// see comment in List.Remove about initialization of l
+	l.move(e, l.root.prev)
+}
+
+// MoveBefore moves element e to its new position before mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveBefore(e, mark *Element[T]) {
+	if e.list != l || e == mark || mark.list != l {
+		return
+	}
+	l.move(e, mark.prev)
+}
+
+// MoveAfter moves element e to its new position after mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveAfter(e, mark *Element[T]) {
+	if e.list != l || e == mark || mark.list != l {
+		return
+	}
+	l.move(e, mark)
+}
+
+// PushBackList inserts a copy of an other list at the back of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushBackList(other *List[T]) {
+	l.lazyInit()
+	for i, e := other.Len(), other.Front(); i > 0; i, e = i-1, e.Next() {
+		l.insertValue(e.Value, l.root.prev)
+	}
+}
+
+// PushFrontList inserts a copy of an other list at the front of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushFrontList(other *List[T]) {
+	l.lazyInit()
+	for i, e := other.Len(), other.Back(); i > 0; i, e = i-1, e.Prev() {
+		l.insertValue(e.Value, &l.root)
+	}
+}
+
+// Transform runs a transform function on a list returning a new list.
+func Transform[TElem1, TElem2 any](lst *List[TElem1], f func(TElem1) TElem2) *List[TElem2] {
+	ret := New[TElem2]()
+	for p := lst.Front(); p != nil; p = p.Next() {
+		ret.PushBack(f(p.Value))
+	}
+	return ret
+}
+
+func CheckListLen[T any](l *List[T], len int) bool {
+	if n := l.Len(); n != len {
+		panic(fmt.Sprintf("l.Len() = %d, want %d", n, len))
+		return false
+	}
+	return true
+}
+
+func CheckListPointers[T any](l *List[T], es []*Element[T]) {
+	root := &l.root
+
+	if !CheckListLen(l, len(es)) {
+		return
+	}
+
+	// zero length lists must be the zero value or properly initialized (sentinel circle)
+	if len(es) == 0 {
+		if l.root.next != nil && l.root.next != root || l.root.prev != nil && l.root.prev != root {
+			panic(fmt.Sprintf("l.root.next = %p, l.root.prev = %p; both should both be nil or %p", l.root.next, l.root.prev, root))
+		}
+		return
+	}
+	// len(es) > 0
+
+	// check internal and external prev/next connections
+	for i, e := range es {
+		prev := root
+		Prev := (*Element[T])(nil)
+		if i > 0 {
+			prev = es[i-1]
+			Prev = prev
+		}
+		if p := e.prev; p != prev {
+			panic(fmt.Sprintf("elt[%d](%p).prev = %p, want %p", i, e, p, prev))
+		}
+		if p := e.Prev(); p != Prev {
+			panic(fmt.Sprintf("elt[%d](%p).Prev() = %p, want %p", i, e, p, Prev))
+		}
+
+		next := root
+		Next := (*Element[T])(nil)
+		if i < len(es)-1 {
+			next = es[i+1]
+			Next = next
+		}
+		if n := e.next; n != next {
+			panic(fmt.Sprintf("elt[%d](%p).next = %p, want %p", i, e, n, next))
+		}
+		if n := e.Next(); n != Next {
+			panic(fmt.Sprintf("elt[%d](%p).Next() = %p, want %p", i, e, n, Next))
+		}
+	}
+}
diff --git a/test/typeparam/listimp2.dir/main.go b/test/typeparam/listimp2.dir/main.go
new file mode 100644
index 00000000000..226e1a9a571
--- /dev/null
+++ b/test/typeparam/listimp2.dir/main.go
@@ -0,0 +1,315 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"strconv"
+)
+
+func TestList() {
+	l := a.New[string]()
+	a.CheckListPointers(l, []*(a.Element[string]){})
+
+	// Single element list
+	e := l.PushFront("a")
+	a.CheckListPointers(l, []*(a.Element[string]){e})
+	l.MoveToFront(e)
+	a.CheckListPointers(l, []*(a.Element[string]){e})
+	l.MoveToBack(e)
+	a.CheckListPointers(l, []*(a.Element[string]){e})
+	l.Remove(e)
+	a.CheckListPointers(l, []*(a.Element[string]){})
+
+	// Bigger list
+	l2 := a.New[int]()
+	e2 := l2.PushFront(2)
+	e1 := l2.PushFront(1)
+	e3 := l2.PushBack(3)
+	e4 := l2.PushBack(600)
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e3, e4})
+
+	l2.Remove(e2)
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e3, e4})
+
+	l2.MoveToFront(e3) // move from middle
+	a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+
+	l2.MoveToFront(e1)
+	l2.MoveToBack(e3) // move from middle
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+
+	l2.MoveToFront(e3) // move from back
+	a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+	l2.MoveToFront(e3) // should be no-op
+	a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+
+	l2.MoveToBack(e3) // move from front
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+	l2.MoveToBack(e3) // should be no-op
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+
+	e2 = l2.InsertBefore(2, e1) // insert before front
+	a.CheckListPointers(l2, []*(a.Element[int]){e2, e1, e4, e3})
+	l2.Remove(e2)
+	e2 = l2.InsertBefore(2, e4) // insert before middle
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e4, e3})
+	l2.Remove(e2)
+	e2 = l2.InsertBefore(2, e3) // insert before back
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e2, e3})
+	l2.Remove(e2)
+
+	e2 = l2.InsertAfter(2, e1) // insert after front
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e4, e3})
+	l2.Remove(e2)
+	e2 = l2.InsertAfter(2, e4) // insert after middle
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e2, e3})
+	l2.Remove(e2)
+	e2 = l2.InsertAfter(2, e3) // insert after back
+	a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3, e2})
+	l2.Remove(e2)
+
+	// Check standard iteration.
+	sum := 0
+	for e := l2.Front(); e != nil; e = e.Next() {
+		sum += e.Value
+	}
+	if sum != 604 {
+		panic(fmt.Sprintf("sum over l = %d, want 604", sum))
+	}
+
+	// Clear all elements by iterating
+	var next *a.Element[int]
+	for e := l2.Front(); e != nil; e = next {
+		next = e.Next()
+		l2.Remove(e)
+	}
+	a.CheckListPointers(l2, []*(a.Element[int]){})
+}
+
+func checkList[T comparable](l *a.List[T], es []interface{}) {
+	if !a.CheckListLen(l, len(es)) {
+		return
+	}
+
+	i := 0
+	for e := l.Front(); e != nil; e = e.Next() {
+		le := e.Value
+		// Comparison between a generically-typed variable le and an interface.
+		if le != es[i] {
+			panic(fmt.Sprintf("elt[%d].Value = %v, want %v", i, le, es[i]))
+		}
+		i++
+	}
+}
+
+func TestExtending() {
+	l1 := a.New[int]()
+	l2 := a.New[int]()
+
+	l1.PushBack(1)
+	l1.PushBack(2)
+	l1.PushBack(3)
+
+	l2.PushBack(4)
+	l2.PushBack(5)
+
+	l3 := a.New[int]()
+	l3.PushBackList(l1)
+	checkList(l3, []interface{}{1, 2, 3})
+	l3.PushBackList(l2)
+	checkList(l3, []interface{}{1, 2, 3, 4, 5})
+
+	l3 = a.New[int]()
+	l3.PushFrontList(l2)
+	checkList(l3, []interface{}{4, 5})
+	l3.PushFrontList(l1)
+	checkList(l3, []interface{}{1, 2, 3, 4, 5})
+
+	checkList(l1, []interface{}{1, 2, 3})
+	checkList(l2, []interface{}{4, 5})
+
+	l3 = a.New[int]()
+	l3.PushBackList(l1)
+	checkList(l3, []interface{}{1, 2, 3})
+	l3.PushBackList(l3)
+	checkList(l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+	l3 = a.New[int]()
+	l3.PushFrontList(l1)
+	checkList(l3, []interface{}{1, 2, 3})
+	l3.PushFrontList(l3)
+	checkList(l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+	l3 = a.New[int]()
+	l1.PushBackList(l3)
+	checkList(l1, []interface{}{1, 2, 3})
+	l1.PushFrontList(l3)
+	checkList(l1, []interface{}{1, 2, 3})
+}
+
+func TestRemove() {
+	l := a.New[int]()
+	e1 := l.PushBack(1)
+	e2 := l.PushBack(2)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e2})
+	e := l.Front()
+	l.Remove(e)
+	a.CheckListPointers(l, []*(a.Element[int]){e2})
+	l.Remove(e)
+	a.CheckListPointers(l, []*(a.Element[int]){e2})
+}
+
+func TestIssue4103() {
+	l1 := a.New[int]()
+	l1.PushBack(1)
+	l1.PushBack(2)
+
+	l2 := a.New[int]()
+	l2.PushBack(3)
+	l2.PushBack(4)
+
+	e := l1.Front()
+	l2.Remove(e) // l2 should not change because e is not an element of l2
+	if n := l2.Len(); n != 2 {
+		panic(fmt.Sprintf("l2.Len() = %d, want 2", n))
+	}
+
+	l1.InsertBefore(8, e)
+	if n := l1.Len(); n != 3 {
+		panic(fmt.Sprintf("l1.Len() = %d, want 3", n))
+	}
+}
+
+func TestIssue6349() {
+	l := a.New[int]()
+	l.PushBack(1)
+	l.PushBack(2)
+
+	e := l.Front()
+	l.Remove(e)
+	if e.Value != 1 {
+		panic(fmt.Sprintf("e.value = %d, want 1", e.Value))
+	}
+	if e.Next() != nil {
+		panic(fmt.Sprintf("e.Next() != nil"))
+	}
+	if e.Prev() != nil {
+		panic(fmt.Sprintf("e.Prev() != nil"))
+	}
+}
+
+func TestMove() {
+	l := a.New[int]()
+	e1 := l.PushBack(1)
+	e2 := l.PushBack(2)
+	e3 := l.PushBack(3)
+	e4 := l.PushBack(4)
+
+	l.MoveAfter(e3, e3)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+	l.MoveBefore(e2, e2)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+
+	l.MoveAfter(e3, e2)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+	l.MoveBefore(e2, e3)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+
+	l.MoveBefore(e2, e4)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e3, e2, e4})
+	e2, e3 = e3, e2
+
+	l.MoveBefore(e4, e1)
+	a.CheckListPointers(l, []*(a.Element[int]){e4, e1, e2, e3})
+	e1, e2, e3, e4 = e4, e1, e2, e3
+
+	l.MoveAfter(e4, e1)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e4, e2, e3})
+	e2, e3, e4 = e4, e2, e3
+
+	l.MoveAfter(e2, e3)
+	a.CheckListPointers(l, []*(a.Element[int]){e1, e3, e2, e4})
+	e2, e3 = e3, e2
+}
+
+// Test PushFront, PushBack, PushFrontList, PushBackList with uninitialized a.List
+func TestZeroList() {
+	var l1 = new(a.List[int])
+	l1.PushFront(1)
+	checkList(l1, []interface{}{1})
+
+	var l2 = new(a.List[int])
+	l2.PushBack(1)
+	checkList(l2, []interface{}{1})
+
+	var l3 = new(a.List[int])
+	l3.PushFrontList(l1)
+	checkList(l3, []interface{}{1})
+
+	var l4 = new(a.List[int])
+	l4.PushBackList(l2)
+	checkList(l4, []interface{}{1})
+}
+
+// Test that a list l is not modified when calling InsertBefore with a mark that is not an element of l.
+func TestInsertBeforeUnknownMark() {
+	var l a.List[int]
+	l.PushBack(1)
+	l.PushBack(2)
+	l.PushBack(3)
+	l.InsertBefore(1, new(a.Element[int]))
+	checkList(&l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling InsertAfter with a mark that is not an element of l.
+func TestInsertAfterUnknownMark() {
+	var l a.List[int]
+	l.PushBack(1)
+	l.PushBack(2)
+	l.PushBack(3)
+	l.InsertAfter(1, new(a.Element[int]))
+	checkList(&l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling MoveAfter or MoveBefore with a mark that is not an element of l.
+func TestMoveUnknownMark() {
+	var l1 a.List[int]
+	e1 := l1.PushBack(1)
+
+	var l2 a.List[int]
+	e2 := l2.PushBack(2)
+
+	l1.MoveAfter(e1, e2)
+	checkList(&l1, []interface{}{1})
+	checkList(&l2, []interface{}{2})
+
+	l1.MoveBefore(e1, e2)
+	checkList(&l1, []interface{}{1})
+	checkList(&l2, []interface{}{2})
+}
+
+// Test the Transform function.
+func TestTransform() {
+	l1 := a.New[int]()
+	l1.PushBack(1)
+	l1.PushBack(2)
+	l2 := a.Transform(l1, strconv.Itoa)
+	checkList(l2, []interface{}{"1", "2"})
+}
+
+func main() {
+	TestList()
+	TestExtending()
+	TestRemove()
+	TestIssue4103()
+	TestIssue6349()
+	TestMove()
+	TestZeroList()
+	TestInsertBeforeUnknownMark()
+	TestInsertAfterUnknownMark()
+	TestTransform()
+}
diff --git a/test/typeparam/listimp2.go b/test/typeparam/listimp2.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/listimp2.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/lockable.go b/test/typeparam/lockable.go
index d53817521f3..9b20d87bb77 100644
--- a/test/typeparam/lockable.go
+++ b/test/typeparam/lockable.go
@@ -8,29 +8,29 @@ package main
 
 import "sync"
 
-// A _Lockable is a value that may be safely simultaneously accessed
+// A Lockable is a value that may be safely simultaneously accessed
 // from multiple goroutines via the Get and Set methods.
-type _Lockable[T any] struct {
-	T
+type Lockable[T any] struct {
+	x  T
 	mu sync.Mutex
 }
 
-// Get returns the value stored in a _Lockable.
-func (l *_Lockable[T]) get() T {
+// Get returns the value stored in a Lockable.
+func (l *Lockable[T]) get() T {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	return l.T
+	return l.x
 }
 
-// set sets the value in a _Lockable.
-func (l *_Lockable[T]) set(v T) {
+// set sets the value in a Lockable.
+func (l *Lockable[T]) set(v T) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	l.T = v
+	l.x = v
 }
 
 func main() {
-	sl := _Lockable[string]{T: "a"}
+	sl := Lockable[string]{x: "a"}
 	if got := sl.get(); got != "a" {
 		panic(got)
 	}
@@ -39,7 +39,7 @@ func main() {
 		panic(got)
 	}
 
-	il := _Lockable[int]{T: 1}
+	il := Lockable[int]{x: 1}
 	if got := il.get(); got != 1 {
 		panic(got)
 	}
diff --git a/test/typeparam/mapimp.dir/a.go b/test/typeparam/mapimp.dir/a.go
new file mode 100644
index 00000000000..cbfa80ac6b1
--- /dev/null
+++ b/test/typeparam/mapimp.dir/a.go
@@ -0,0 +1,15 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+// Map calls the function f on every element of the slice s,
+// returning a new slice of the results.
+func Mapper[F, T any](s []F, f func(F) T) []T {
+	r := make([]T, len(s))
+	for i, v := range s {
+		r[i] = f(v)
+	}
+	return r
+}
diff --git a/test/typeparam/mapimp.dir/main.go b/test/typeparam/mapimp.dir/main.go
new file mode 100644
index 00000000000..4d4a4d9eb0b
--- /dev/null
+++ b/test/typeparam/mapimp.dir/main.go
@@ -0,0 +1,28 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+func main() {
+	got := a.Mapper([]int{1, 2, 3}, strconv.Itoa)
+	want := []string{"1", "2", "3"}
+	if !reflect.DeepEqual(got, want) {
+		panic(fmt.Sprintf("got %s, want %s", got, want))
+	}
+
+	fgot := a.Mapper([]float64{2.5, 2.3, 3.5}, func(f float64) string {
+		return strconv.FormatFloat(f, 'f', -1, 64)
+	})
+	fwant := []string{"2.5", "2.3", "3.5"}
+	if !reflect.DeepEqual(fgot, fwant) {
+		panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
+	}
+}
diff --git a/test/typeparam/mapimp.go b/test/typeparam/mapimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/mapimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mapsimp.dir/a.go b/test/typeparam/mapsimp.dir/a.go
new file mode 100644
index 00000000000..696e2a56801
--- /dev/null
+++ b/test/typeparam/mapsimp.dir/a.go
@@ -0,0 +1,108 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+// SliceEqual reports whether two slices are equal: the same length and all
+// elements equal. All floating point NaNs are considered equal.
+func SliceEqual[Elem comparable](s1, s2 []Elem) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if v1 != v2 {
+			isNaN := func(f Elem) bool { return f != f }
+			if !isNaN(v1) || !isNaN(v2) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Keys returns the keys of the map m.
+// The keys will be an indeterminate order.
+func Keys[K comparable, V any](m map[K]V) []K {
+	r := make([]K, 0, len(m))
+	for k := range m {
+		r = append(r, k)
+	}
+	return r
+}
+
+// Values returns the values of the map m.
+// The values will be in an indeterminate order.
+func Values[K comparable, V any](m map[K]V) []V {
+	r := make([]V, 0, len(m))
+	for _, v := range m {
+		r = append(r, v)
+	}
+	return r
+}
+
+// Equal reports whether two maps contain the same key/value pairs.
+// Values are compared using ==.
+func Equal[K, V comparable](m1, m2 map[K]V) bool {
+	if len(m1) != len(m2) {
+		return false
+	}
+	for k, v1 := range m1 {
+		if v2, ok := m2[k]; !ok || v1 != v2 {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy returns a copy of m.
+func Copy[K comparable, V any](m map[K]V) map[K]V {
+	r := make(map[K]V, len(m))
+	for k, v := range m {
+		r[k] = v
+	}
+	return r
+}
+
+// Add adds all key/value pairs in m2 to m1. Keys in m2 that are already
+// present in m1 will be overwritten with the value in m2.
+func Add[K comparable, V any](m1, m2 map[K]V) {
+	for k, v := range m2 {
+		m1[k] = v
+	}
+}
+
+// Sub removes all keys in m2 from m1. Keys in m2 that are not present
+// in m1 are ignored. The values in m2 are ignored.
+func Sub[K comparable, V any](m1, m2 map[K]V) {
+	for k := range m2 {
+		delete(m1, k)
+	}
+}
+
+// Intersect removes all keys from m1 that are not present in m2.
+// Keys in m2 that are not in m1 are ignored. The values in m2 are ignored.
+func Intersect[K comparable, V any](m1, m2 map[K]V) {
+	for k := range m1 {
+		if _, ok := m2[k]; !ok {
+			delete(m1, k)
+		}
+	}
+}
+
+// Filter deletes any key/value pairs from m for which f returns false.
+func Filter[K comparable, V any](m map[K]V, f func(K, V) bool) {
+	for k, v := range m {
+		if !f(k, v) {
+			delete(m, k)
+		}
+	}
+}
+
+// TransformValues applies f to each value in m. The keys remain unchanged.
+func TransformValues[K comparable, V any](m map[K]V, f func(V) V) {
+	for k, v := range m {
+		m[k] = f(v)
+	}
+}
diff --git a/test/typeparam/mapsimp.dir/main.go b/test/typeparam/mapsimp.dir/main.go
new file mode 100644
index 00000000000..873660e4cd5
--- /dev/null
+++ b/test/typeparam/mapsimp.dir/main.go
@@ -0,0 +1,156 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"math"
+	"sort"
+)
+
+var m1 = map[int]int{1: 2, 2: 4, 4: 8, 8: 16}
+var m2 = map[int]string{1: "2", 2: "4", 4: "8", 8: "16"}
+
+func TestKeys() {
+	want := []int{1, 2, 4, 8}
+
+	got1 := a.Keys(m1)
+	sort.Ints(got1)
+	if !a.SliceEqual(got1, want) {
+		panic(fmt.Sprintf("a.Keys(%v) = %v, want %v", m1, got1, want))
+	}
+
+	got2 := a.Keys(m2)
+	sort.Ints(got2)
+	if !a.SliceEqual(got2, want) {
+		panic(fmt.Sprintf("a.Keys(%v) = %v, want %v", m2, got2, want))
+	}
+}
+
+func TestValues() {
+	got1 := a.Values(m1)
+	want1 := []int{2, 4, 8, 16}
+	sort.Ints(got1)
+	if !a.SliceEqual(got1, want1) {
+		panic(fmt.Sprintf("a.Values(%v) = %v, want %v", m1, got1, want1))
+	}
+
+	got2 := a.Values(m2)
+	want2 := []string{"16", "2", "4", "8"}
+	sort.Strings(got2)
+	if !a.SliceEqual(got2, want2) {
+		panic(fmt.Sprintf("a.Values(%v) = %v, want %v", m2, got2, want2))
+	}
+}
+
+func TestEqual() {
+	if !a.Equal(m1, m1) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", m1, m1))
+	}
+	if a.Equal(m1, nil) {
+		panic(fmt.Sprintf("a.Equal(%v, nil) = true, want false", m1))
+	}
+	if a.Equal(nil, m1) {
+		panic(fmt.Sprintf("a.Equal(nil, %v) = true, want false", m1))
+	}
+	if !a.Equal[int, int](nil, nil) {
+		panic("a.Equal(nil, nil) = false, want true")
+	}
+	if ms := map[int]int{1: 2}; a.Equal(m1, ms) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", m1, ms))
+	}
+
+	// Comparing NaN for equality is expected to fail.
+	mf := map[int]float64{1: 0, 2: math.NaN()}
+	if a.Equal(mf, mf) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", mf, mf))
+	}
+}
+
+func TestCopy() {
+	m2 := a.Copy(m1)
+	if !a.Equal(m1, m2) {
+		panic(fmt.Sprintf("a.Copy(%v) = %v, want %v", m1, m2, m1))
+	}
+	m2[16] = 32
+	if a.Equal(m1, m2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", m1, m2))
+	}
+}
+
+func TestAdd() {
+	mc := a.Copy(m1)
+	a.Add(mc, mc)
+	if !a.Equal(mc, m1) {
+		panic(fmt.Sprintf("a.Add(%v, %v) = %v, want %v", m1, m1, mc, m1))
+	}
+	a.Add(mc, map[int]int{16: 32})
+	want := map[int]int{1: 2, 2: 4, 4: 8, 8: 16, 16: 32}
+	if !a.Equal(mc, want) {
+		panic(fmt.Sprintf("a.Add result = %v, want %v", mc, want))
+	}
+}
+
+func TestSub() {
+	mc := a.Copy(m1)
+	a.Sub(mc, mc)
+	if len(mc) > 0 {
+		panic(fmt.Sprintf("a.Sub(%v, %v) = %v, want empty map", m1, m1, mc))
+	}
+	mc = a.Copy(m1)
+	a.Sub(mc, map[int]int{1: 0})
+	want := map[int]int{2: 4, 4: 8, 8: 16}
+	if !a.Equal(mc, want) {
+		panic(fmt.Sprintf("a.Sub result = %v, want %v", mc, want))
+	}
+}
+
+func TestIntersect() {
+	mc := a.Copy(m1)
+	a.Intersect(mc, mc)
+	if !a.Equal(mc, m1) {
+		panic(fmt.Sprintf("a.Intersect(%v, %v) = %v, want %v", m1, m1, mc, m1))
+	}
+	a.Intersect(mc, map[int]int{1: 0, 2: 0})
+	want := map[int]int{1: 2, 2: 4}
+	if !a.Equal(mc, want) {
+		panic(fmt.Sprintf("a.Intersect result = %v, want %v", mc, want))
+	}
+}
+
+func TestFilter() {
+	mc := a.Copy(m1)
+	a.Filter(mc, func(int, int) bool { return true })
+	if !a.Equal(mc, m1) {
+		panic(fmt.Sprintf("a.Filter(%v, true) = %v, want %v", m1, mc, m1))
+	}
+	a.Filter(mc, func(k, v int) bool { return k < 3 })
+	want := map[int]int{1: 2, 2: 4}
+	if !a.Equal(mc, want) {
+		panic(fmt.Sprintf("a.Filter result = %v, want %v", mc, want))
+	}
+}
+
+func TestTransformValues() {
+	mc := a.Copy(m1)
+	a.TransformValues(mc, func(i int) int { return i / 2 })
+	want := map[int]int{1: 1, 2: 2, 4: 4, 8: 8}
+	if !a.Equal(mc, want) {
+		panic(fmt.Sprintf("a.TransformValues result = %v, want %v", mc, want))
+	}
+}
+
+func main() {
+	TestKeys()
+	TestValues()
+	TestEqual()
+	TestCopy()
+	TestAdd()
+	TestSub()
+	TestIntersect()
+	TestFilter()
+	TestTransformValues()
+}
diff --git a/test/typeparam/mapsimp.go b/test/typeparam/mapsimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/mapsimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/1.dir/a.go b/test/typeparam/mdempsky/1.dir/a.go
new file mode 100644
index 00000000000..a668eb52dc9
--- /dev/null
+++ b/test/typeparam/mdempsky/1.dir/a.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type T[_ any] int
+
+func F() { _ = new(T[int]) }
diff --git a/test/typeparam/mdempsky/1.dir/b.go b/test/typeparam/mdempsky/1.dir/b.go
new file mode 100644
index 00000000000..af6fef3f6d8
--- /dev/null
+++ b/test/typeparam/mdempsky/1.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "./a"
+
+func main() { a.F() }
diff --git a/test/typeparam/mdempsky/1.go b/test/typeparam/mdempsky/1.go
new file mode 100644
index 00000000000..87b4ff46c1e
--- /dev/null
+++ b/test/typeparam/mdempsky/1.go
@@ -0,0 +1,7 @@
+// compiledir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/10.dir/a.go b/test/typeparam/mdempsky/10.dir/a.go
new file mode 100644
index 00000000000..95e111d3470
--- /dev/null
+++ b/test/typeparam/mdempsky/10.dir/a.go
@@ -0,0 +1,7 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type I[T any] interface{ M() T }
diff --git a/test/typeparam/mdempsky/10.dir/b.go b/test/typeparam/mdempsky/10.dir/b.go
new file mode 100644
index 00000000000..0ef28fd02de
--- /dev/null
+++ b/test/typeparam/mdempsky/10.dir/b.go
@@ -0,0 +1,17 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "./a"
+
+var m = a.I[int].M
+
+var never bool
+
+func main() {
+	if never {
+		m(nil)
+	}
+}
diff --git a/test/typeparam/mdempsky/10.go b/test/typeparam/mdempsky/10.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/mdempsky/10.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/11.go b/test/typeparam/mdempsky/11.go
new file mode 100644
index 00000000000..e86c038a104
--- /dev/null
+++ b/test/typeparam/mdempsky/11.go
@@ -0,0 +1,16 @@
+// errorcheck
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Reported by Cuong Manh Le.
+
+package p
+
+type a struct{}
+
+//go:notinheap
+type b a
+
+var _ = (*b)(new(a)) // ERROR "cannot convert"
diff --git a/test/typeparam/mdempsky/12.dir/a.go b/test/typeparam/mdempsky/12.dir/a.go
new file mode 100644
index 00000000000..ee8be939a8f
--- /dev/null
+++ b/test/typeparam/mdempsky/12.dir/a.go
@@ -0,0 +1,11 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type S[T any] struct {
+	F T
+}
+
+var X = S[int]{}
diff --git a/test/typeparam/mdempsky/12.dir/main.go b/test/typeparam/mdempsky/12.dir/main.go
new file mode 100644
index 00000000000..2891322e298
--- /dev/null
+++ b/test/typeparam/mdempsky/12.dir/main.go
@@ -0,0 +1,13 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"./a"
+)
+
+func main() {
+	_ = a.X
+}
diff --git a/test/typeparam/mdempsky/12.go b/test/typeparam/mdempsky/12.go
new file mode 100644
index 00000000000..a2dc4daaccc
--- /dev/null
+++ b/test/typeparam/mdempsky/12.go
@@ -0,0 +1,9 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Reported by Cuong Manh Le.
+
+package ignored
diff --git a/test/typeparam/mdempsky/13.go b/test/typeparam/mdempsky/13.go
new file mode 100644
index 00000000000..b492774d3d8
--- /dev/null
+++ b/test/typeparam/mdempsky/13.go
@@ -0,0 +1,84 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// Interface which will be used as a regular interface type and as a type bound.
+type Mer interface{
+	M()
+}
+
+// Interface that is a superset of Mer.
+type Mer2 interface {
+	M()
+	String() string
+}
+
+func F[T Mer](t T) {
+	T.M(t)
+	t.M()
+}
+
+type MyMer int
+
+func (MyMer) M() {}
+func (MyMer) String() string {
+	return "aa"
+}
+
+// Parameterized interface
+type Abs[T any] interface {
+	Abs() T
+}
+
+func G[T Abs[U], U any](t T) {
+	T.Abs(t)
+	t.Abs()
+}
+
+type MyInt int
+func (m MyInt) Abs() MyInt {
+	if m < 0 {
+		return -m
+	}
+	return m
+}
+
+type Abs2 interface {
+	Abs() MyInt
+}
+
+
+func main() {
+	mm := MyMer(3)
+	ms := struct{ Mer }{Mer: mm }
+
+	// Testing F with an interface type arg: Mer and Mer2
+	F[Mer](mm)
+	F[Mer2](mm)
+	F[struct{ Mer }](ms)
+	F[*struct{ Mer }](&ms)
+
+	ms2 := struct { MyMer }{MyMer: mm}
+	ms3 := struct { *MyMer }{MyMer: &mm}
+
+	// Testing F with a concrete type arg
+	F[MyMer](mm)
+	F[*MyMer](&mm)
+	F[struct{ MyMer }](ms2)
+	F[struct{ *MyMer }](ms3)
+	F[*struct{ MyMer }](&ms2)
+	F[*struct{ *MyMer }](&ms3)
+
+	// Testing G with a concrete type args
+	mi := MyInt(-3)
+	G[MyInt,MyInt](mi)
+
+	// Interface Abs[MyInt] holding an mi.
+	intMi := Abs[MyInt](mi)
+	// First type arg here is Abs[MyInt], an interface type.
+	G[Abs[MyInt],MyInt](intMi)
+}
diff --git a/test/typeparam/mdempsky/14.go b/test/typeparam/mdempsky/14.go
new file mode 100644
index 00000000000..ba685bc35c8
--- /dev/null
+++ b/test/typeparam/mdempsky/14.go
@@ -0,0 +1,40 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// Zero returns the zero value of T
+func Zero[T any]() (_ T) {
+	return
+}
+
+type AnyInt[X any] int
+
+func (AnyInt[X]) M() {
+	var have interface{} = Zero[X]()
+	var want interface{} = Zero[MyInt]()
+
+	if have != want {
+		println("FAIL")
+	}
+}
+
+type I interface{ M() }
+
+type MyInt int
+type U = AnyInt[MyInt]
+
+var x = U(0)
+var i I = x
+
+func main() {
+	x.M()
+	U.M(x)
+	(*U).M(&x)
+
+	i.M()
+	I.M(x)
+}
diff --git a/test/typeparam/mdempsky/15.go b/test/typeparam/mdempsky/15.go
new file mode 100644
index 00000000000..4899fc75eec
--- /dev/null
+++ b/test/typeparam/mdempsky/15.go
@@ -0,0 +1,69 @@
+// run -goexperiment fieldtrack -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that generics, promoted methods, and //go:nointerface
+// interoperate as expected.
+
+package main
+
+import (
+	"reflect"
+)
+
+func TypeString[T any]() string {
+	return reflect.TypeOf(new(T)).Elem().String()
+}
+
+func Test[T, Bad, Good any]() {
+	switch interface{}(new(T)).(type) {
+	case Bad:
+		println("FAIL:", TypeString[T](), "matched", TypeString[Bad]())
+	case Good:
+		// ok
+	default:
+		println("FAIL:", TypeString[T](), "did not match", TypeString[Good]())
+	}
+}
+
+func TestE[T any]() { Test[T, interface{ EBad() }, interface{ EGood() }]() }
+func TestX[T any]() { Test[T, interface{ XBad() }, interface{ XGood() }]() }
+
+type E struct{}
+
+//go:nointerface
+func (E) EBad()  {}
+func (E) EGood() {}
+
+type X[T any] struct{ E }
+
+//go:nointerface
+func (X[T]) XBad()  {}
+func (X[T]) XGood() {}
+
+type W struct{ X[int] }
+
+func main() {
+	_ = E.EGood
+	_ = E.EBad
+
+	TestE[E]()
+
+	_ = X[int].EGood
+	_ = X[int].EBad
+	_ = X[int].XGood
+	_ = X[int].XBad
+
+	TestE[X[int]]()
+	TestX[X[int]]()
+
+	_ = W.EGood
+	_ = W.EBad
+	_ = W.XGood
+	_ = W.XBad
+
+	TestE[W]()
+	TestX[W]()
+}
diff --git a/test/typeparam/mdempsky/2.go b/test/typeparam/mdempsky/2.go
new file mode 100644
index 00000000000..f09730f9491
--- /dev/null
+++ b/test/typeparam/mdempsky/2.go
@@ -0,0 +1,20 @@
+// compile -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type T[A, B, C any] int
+
+func (T[A, B, C]) m(x int) {
+	if x <= 0 {
+		return
+	}
+	T[B, C, A](0).m(x - 1)
+}
+
+func main() {
+	T[int8, int16, int32](0).m(3)
+}
diff --git a/test/typeparam/mdempsky/3.dir/a.go b/test/typeparam/mdempsky/3.dir/a.go
new file mode 100644
index 00000000000..cf456e8d48f
--- /dev/null
+++ b/test/typeparam/mdempsky/3.dir/a.go
@@ -0,0 +1,7 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func F[T interface{ chan int }](c T) {}
diff --git a/test/typeparam/mdempsky/3.dir/b.go b/test/typeparam/mdempsky/3.dir/b.go
new file mode 100644
index 00000000000..0cfd142f4c4
--- /dev/null
+++ b/test/typeparam/mdempsky/3.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+func g() { a.F(make(chan int)) }
diff --git a/test/typeparam/mdempsky/3.go b/test/typeparam/mdempsky/3.go
new file mode 100644
index 00000000000..87b4ff46c1e
--- /dev/null
+++ b/test/typeparam/mdempsky/3.go
@@ -0,0 +1,7 @@
+// compiledir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/4.dir/a.go b/test/typeparam/mdempsky/4.dir/a.go
new file mode 100644
index 00000000000..cb672949eae
--- /dev/null
+++ b/test/typeparam/mdempsky/4.dir/a.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func F[T any](T) {
+Loop:
+	for {
+		break Loop
+	}
+}
diff --git a/test/typeparam/mdempsky/4.dir/b.go b/test/typeparam/mdempsky/4.dir/b.go
new file mode 100644
index 00000000000..e1fb0e7c5ea
--- /dev/null
+++ b/test/typeparam/mdempsky/4.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+func f() { a.F(0) }
diff --git a/test/typeparam/mdempsky/4.go b/test/typeparam/mdempsky/4.go
new file mode 100644
index 00000000000..87b4ff46c1e
--- /dev/null
+++ b/test/typeparam/mdempsky/4.go
@@ -0,0 +1,7 @@
+// compiledir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/5.go b/test/typeparam/mdempsky/5.go
new file mode 100644
index 00000000000..0d1ad399462
--- /dev/null
+++ b/test/typeparam/mdempsky/5.go
@@ -0,0 +1,15 @@
+// compile -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type X[T any] int
+
+func (X[T]) F(T) {}
+
+func x() {
+	X[interface{}](0).F(0)
+}
diff --git a/test/typeparam/mdempsky/6.go b/test/typeparam/mdempsky/6.go
new file mode 100644
index 00000000000..a26ff62f6d4
--- /dev/null
+++ b/test/typeparam/mdempsky/6.go
@@ -0,0 +1,11 @@
+// compile -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type I[T any] interface{ M() T }
+
+var _ = I[int].M
diff --git a/test/typeparam/mdempsky/7.dir/a.go b/test/typeparam/mdempsky/7.dir/a.go
new file mode 100644
index 00000000000..59c59956118
--- /dev/null
+++ b/test/typeparam/mdempsky/7.dir/a.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type I[T any] interface{ M() T }
+
+var X I[int]
diff --git a/test/typeparam/mdempsky/7.dir/b.go b/test/typeparam/mdempsky/7.dir/b.go
new file mode 100644
index 00000000000..9f705308114
--- /dev/null
+++ b/test/typeparam/mdempsky/7.dir/b.go
@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+var _ = a.X
diff --git a/test/typeparam/mdempsky/7.go b/test/typeparam/mdempsky/7.go
new file mode 100644
index 00000000000..87b4ff46c1e
--- /dev/null
+++ b/test/typeparam/mdempsky/7.go
@@ -0,0 +1,7 @@
+// compiledir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/8.dir/a.go b/test/typeparam/mdempsky/8.dir/a.go
new file mode 100644
index 00000000000..607fe5e0af2
--- /dev/null
+++ b/test/typeparam/mdempsky/8.dir/a.go
@@ -0,0 +1,7 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func F[T interface{ comparable }]() {}
diff --git a/src/cmd/gofmt/gofmt_typeparams_test.go b/test/typeparam/mdempsky/8.dir/b.go
similarity index 68%
rename from src/cmd/gofmt/gofmt_typeparams_test.go
rename to test/typeparam/mdempsky/8.dir/b.go
index 10641a77cb2..ef2637b894f 100644
--- a/src/cmd/gofmt/gofmt_typeparams_test.go
+++ b/test/typeparam/mdempsky/8.dir/b.go
@@ -2,11 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build typeparams
-// +build typeparams
+package b
 
-package main
+import "./a"
 
 func init() {
-	typeParamsEnabled = true
+	a.F[func()]() // ERROR "does not satisfy comparable"
 }
diff --git a/test/typeparam/mdempsky/8.go b/test/typeparam/mdempsky/8.go
new file mode 100644
index 00000000000..32cf4b830d2
--- /dev/null
+++ b/test/typeparam/mdempsky/8.go
@@ -0,0 +1,7 @@
+// errorcheckdir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mdempsky/9.go b/test/typeparam/mdempsky/9.go
new file mode 100644
index 00000000000..b72516c4eab
--- /dev/null
+++ b/test/typeparam/mdempsky/9.go
@@ -0,0 +1,11 @@
+// compile -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+func f[V any]() []V { return []V{0: *new(V)} }
+
+func g() { f[int]() }
diff --git a/test/typeparam/min.go b/test/typeparam/min.go
index a3e4464a303..d6c65d68b79 100644
--- a/test/typeparam/min.go
+++ b/test/typeparam/min.go
@@ -11,7 +11,7 @@ import (
 )
 
 type Ordered interface {
-	type int, int64, float64
+	~int | ~int64 | ~float64 | ~string
 }
 
 func min[T Ordered](x, y T) T {
@@ -38,4 +38,13 @@ func main() {
 	if got := min(3.5, 2.0); got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
+
+	const want2 = "ay"
+	if got := min[string]("bb", "ay"); got != want2 {
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
+
+	if got := min("bb", "ay"); got != want2 {
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
 }
diff --git a/test/typeparam/mincheck.dir/a.go b/test/typeparam/mincheck.dir/a.go
new file mode 100644
index 00000000000..fa0f249e615
--- /dev/null
+++ b/test/typeparam/mincheck.dir/a.go
@@ -0,0 +1,16 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Ordered interface {
+	int | int64 | float64
+}
+
+func Min[T Ordered](x, y T) T {
+	if x < y {
+		return x
+	}
+	return y
+}
diff --git a/test/typeparam/mincheck.dir/main.go b/test/typeparam/mincheck.dir/main.go
new file mode 100644
index 00000000000..9cf2c6bafd6
--- /dev/null
+++ b/test/typeparam/mincheck.dir/main.go
@@ -0,0 +1,38 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	const want = 2
+	if got := a.Min[int](2, 3); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Min(2, 3); got != want {
+		panic(fmt.Sprintf("want %d, got %d", want, got))
+	}
+
+	if got := a.Min[float64](3.5, 2.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Min(3.5, 2.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	const want2 = "ay"
+	if got := a.Min[string]("bb", "ay"); got != want2 { // ERROR "string does not satisfy"
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
+
+	if got := a.Min("bb", "ay"); got != want2 { // ERROR "string does not satisfy"
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
+}
diff --git a/test/typeparam/mincheck.go b/test/typeparam/mincheck.go
new file mode 100644
index 00000000000..32cf4b830d2
--- /dev/null
+++ b/test/typeparam/mincheck.go
@@ -0,0 +1,7 @@
+// errorcheckdir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/minimp.dir/a.go b/test/typeparam/minimp.dir/a.go
new file mode 100644
index 00000000000..fabde62c5d7
--- /dev/null
+++ b/test/typeparam/minimp.dir/a.go
@@ -0,0 +1,16 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Ordered interface {
+	~int | ~int64 | ~float64 | ~string
+}
+
+func Min[T Ordered](x, y T) T {
+	if x < y {
+		return x
+	}
+	return y
+}
diff --git a/test/typeparam/minimp.dir/main.go b/test/typeparam/minimp.dir/main.go
new file mode 100644
index 00000000000..509f5aaed2b
--- /dev/null
+++ b/test/typeparam/minimp.dir/main.go
@@ -0,0 +1,38 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	const want = 2
+	if got := a.Min[int](2, 3); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Min(2, 3); got != want {
+		panic(fmt.Sprintf("want %d, got %d", want, got))
+	}
+
+	if got := a.Min[float64](3.5, 2.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	if got := a.Min(3.5, 2.0); got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
+	}
+
+	const want2 = "ay"
+	if got := a.Min[string]("bb", "ay"); got != want2 {
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
+
+	if got := a.Min("bb", "ay"); got != want2 {
+		panic(fmt.Sprintf("got %d, want %d", got, want2))
+	}
+}
diff --git a/test/typeparam/minimp.go b/test/typeparam/minimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/minimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/mutualimp.dir/a.go b/test/typeparam/mutualimp.dir/a.go
new file mode 100644
index 00000000000..5b924d3ce5d
--- /dev/null
+++ b/test/typeparam/mutualimp.dir/a.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type X int
+
+func (x X) M() X { return x }
+
+func F[T interface{ M() U }, U interface{ M() T }]() {}
+func G()                                             { F[X, X]() }
diff --git a/test/typeparam/mutualimp.dir/b.go b/test/typeparam/mutualimp.dir/b.go
new file mode 100644
index 00000000000..83cc3af2835
--- /dev/null
+++ b/test/typeparam/mutualimp.dir/b.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+func H() {
+	a.F[a.X, a.X]()
+	a.G()
+}
diff --git a/test/typeparam/mutualimp.go b/test/typeparam/mutualimp.go
new file mode 100644
index 00000000000..87b4ff46c1e
--- /dev/null
+++ b/test/typeparam/mutualimp.go
@@ -0,0 +1,7 @@
+// compiledir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/nested.go b/test/typeparam/nested.go
new file mode 100644
index 00000000000..c0037a3e6e4
--- /dev/null
+++ b/test/typeparam/nested.go
@@ -0,0 +1,134 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This test case stress tests a number of subtle cases involving
+// nested type-parameterized declarations. At a high-level, it
+// declares a generic function that contains a generic type
+// declaration:
+//
+//	func F[A intish]() {
+//		type T[B intish] struct{}
+//
+//		// store reflect.Type tuple (A, B, F[A].T[B]) in tests
+//	}
+//
+// It then instantiates this function with a variety of type arguments
+// for A and B. Particularly tricky things like shadowed types.
+//
+// From this data it tests two things:
+//
+// 1. Given tuples (A, B, F[A].T[B]) and (A', B', F[A'].T[B']),
+//    F[A].T[B] should be identical to F[A'].T[B'] iff (A, B) is
+//    identical to (A', B').
+//
+// 2. A few of the instantiations are constructed to be identical, and
+//    it tests that exactly these pairs are duplicated (by golden
+//    output comparison to nested.out).
+//
+// In both cases, we're effectively using the compiler's existing
+// runtime.Type handling (which is well tested) of type identity of A
+// and B as a way to help bootstrap testing and validate its new
+// runtime.Type handling of F[A].T[B].
+//
+// This isn't perfect, but it smoked out a handful of issues in
+// gotypes2 and unified IR.
+
+package main
+
+import (
+	"fmt"
+	"reflect"
+)
+
+type test struct {
+	TArgs    [2]reflect.Type
+	Instance reflect.Type
+}
+
+var tests []test
+
+type intish interface{ ~int }
+
+type Int int
+type GlobalInt = Int // allow access to global Int, even when shadowed
+
+func F[A intish]() {
+	add := func(B, T interface{}) {
+		tests = append(tests, test{
+			TArgs: [2]reflect.Type{
+				reflect.TypeOf(A(0)),
+				reflect.TypeOf(B),
+			},
+			Instance: reflect.TypeOf(T),
+		})
+	}
+
+	type Int int
+
+	type T[B intish] struct{}
+
+	add(int(0), T[int]{})
+	add(Int(0), T[Int]{})
+	add(GlobalInt(0), T[GlobalInt]{})
+	add(A(0), T[A]{}) // NOTE: intentionally dups with int and GlobalInt
+
+	type U[_ any] int
+	type V U[int]
+	type W V
+
+	add(U[int](0), T[U[int]]{})
+	add(U[Int](0), T[U[Int]]{})
+	add(U[GlobalInt](0), T[U[GlobalInt]]{})
+	add(U[A](0), T[U[A]]{}) // NOTE: intentionally dups with U[int] and U[GlobalInt]
+	add(V(0), T[V]{})
+	add(W(0), T[W]{})
+}
+
+func main() {
+	type Int int
+
+	F[int]()
+	F[Int]()
+	F[GlobalInt]()
+
+	type U[_ any] int
+	type V U[int]
+	type W V
+
+	F[U[int]]()
+	F[U[Int]]()
+	F[U[GlobalInt]]()
+	F[V]()
+	F[W]()
+
+	type X[A any] U[X[A]]
+
+	F[X[int]]()
+	F[X[Int]]()
+	F[X[GlobalInt]]()
+
+	for j, tj := range tests {
+		for i, ti := range tests[:j+1] {
+			if (ti.TArgs == tj.TArgs) != (ti.Instance == tj.Instance) {
+				fmt.Printf("FAIL: %d,%d: %s, but %s\n", i, j, eq(ti.TArgs, tj.TArgs), eq(ti.Instance, tj.Instance))
+			}
+
+			// The test is constructed so we should see a few identical types.
+			// See "NOTE" comments above.
+			if i != j && ti.Instance == tj.Instance {
+				fmt.Printf("%d,%d: %v\n", i, j, ti.Instance)
+			}
+		}
+	}
+}
+
+func eq(a, b interface{}) string {
+	op := "=="
+	if a != b {
+		op = "!="
+	}
+	return fmt.Sprintf("%v %s %v", a, op, b)
+}
diff --git a/test/typeparam/nested.out b/test/typeparam/nested.out
new file mode 100644
index 00000000000..91105182482
--- /dev/null
+++ b/test/typeparam/nested.out
@@ -0,0 +1,4 @@
+0,3: main.T·2[int;int]
+4,7: main.T·2[int;"".U·3[int;int]]
+22,23: main.T·2["".Int;"".Int]
+26,27: main.T·2["".Int;"".U·3["".Int;"".Int]]
diff --git a/test/typeparam/ordered.go b/test/typeparam/ordered.go
index 448db68bb55..0f539d659c3 100644
--- a/test/typeparam/ordered.go
+++ b/test/typeparam/ordered.go
@@ -13,15 +13,15 @@ import (
 )
 
 type Ordered interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		string
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
 }
 
 type orderedSlice[Elem Ordered] []Elem
 
-func (s orderedSlice[Elem]) Len() int           { return len(s) }
+func (s orderedSlice[Elem]) Len() int { return len(s) }
 func (s orderedSlice[Elem]) Less(i, j int) bool {
 	if s[i] < s[j] {
 		return true
@@ -32,7 +32,7 @@ func (s orderedSlice[Elem]) Less(i, j int) bool {
 	}
 	return false
 }
-func (s orderedSlice[Elem]) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s orderedSlice[Elem]) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
 
 func _OrderedSlice[Elem Ordered](s []Elem) {
 	sort.Sort(orderedSlice[Elem](s))
@@ -68,7 +68,7 @@ func testOrdered[Elem Ordered](name string, s []Elem, sorter func([]Elem)) bool
 	}
 	for i := len(s1) - 1; i > 0; i-- {
 		if s1[i] < s1[i-1] {
-			fmt.Printf("%s: element %d (%v) < element %d (%v)", name, i, s1[i], i - 1, s1[i - 1])
+			fmt.Printf("%s: element %d (%v) < element %d (%v)", name, i, s1[i], i-1, s1[i-1])
 			ok = false
 		}
 	}
diff --git a/test/typeparam/orderedmap.go b/test/typeparam/orderedmap.go
index db1b3742674..1f077333b8f 100644
--- a/test/typeparam/orderedmap.go
+++ b/test/typeparam/orderedmap.go
@@ -15,10 +15,10 @@ import (
 )
 
 type Ordered interface {
-        type int, int8, int16, int32, int64,
-                uint, uint8, uint16, uint32, uint64, uintptr,
-                float32, float64,
-                string
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
 }
 
 // _Map is an ordered map.
@@ -230,7 +230,7 @@ func _Ranger[Elem any]() (*_Sender[Elem], *_Receiver[Elem]) {
 		values: c,
 		done:   d,
 	}
-	r := &_Receiver[Elem] {
+	r := &_Receiver[Elem]{
 		values: c,
 		done:   d,
 	}
diff --git a/test/typeparam/orderedmapsimp.dir/a.go b/test/typeparam/orderedmapsimp.dir/a.go
new file mode 100644
index 00000000000..d6a2de5d7b3
--- /dev/null
+++ b/test/typeparam/orderedmapsimp.dir/a.go
@@ -0,0 +1,226 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+import (
+	"context"
+	"runtime"
+)
+
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// Map is an ordered map.
+type Map[K, V any] struct {
+	root    *node[K, V]
+	compare func(K, K) int
+}
+
+// node is the type of a node in the binary tree.
+type node[K, V any] struct {
+	key         K
+	val         V
+	left, right *node[K, V]
+}
+
+// New returns a new map. It takes a comparison function that compares two
+// keys and returns < 0 if the first is less, == 0 if they are equal,
+// > 0 if the first is greater.
+func New[K, V any](compare func(K, K) int) *Map[K, V] {
+	return &Map[K, V]{compare: compare}
+}
+
+// NewOrdered returns a new map whose key is an ordered type.
+// This is like New, but does not require providing a compare function.
+// The map compare function uses the obvious key ordering.
+func NewOrdered[K Ordered, V any]() *Map[K, V] {
+	return New[K, V](func(k1, k2 K) int {
+		switch {
+		case k1 < k2:
+			return -1
+		case k1 > k2:
+			return 1
+		default:
+			return 0
+		}
+	})
+}
+
+// find looks up key in the map, returning either a pointer to the slot of the
+// node holding key, or a pointer to the slot where a node would go.
+func (m *Map[K, V]) find(key K) **node[K, V] {
+	pn := &m.root
+	for *pn != nil {
+		switch cmp := m.compare(key, (*pn).key); {
+		case cmp < 0:
+			pn = &(*pn).left
+		case cmp > 0:
+			pn = &(*pn).right
+		default:
+			return pn
+		}
+	}
+	return pn
+}
+
+// Insert inserts a new key/value into the map.
+// If the key is already present, the value is replaced.
+// Reports whether this is a new key.
+func (m *Map[K, V]) Insert(key K, val V) bool {
+	pn := m.find(key)
+	if *pn != nil {
+		(*pn).val = val
+		return false
+	}
+	*pn = &node[K, V]{key: key, val: val}
+	return true
+}
+
+// Find returns the value associated with a key, or the zero value
+// if not present. The second result reports whether the key was found.
+func (m *Map[K, V]) Find(key K) (V, bool) {
+	pn := m.find(key)
+	if *pn == nil {
+		var zero V
+		return zero, false
+	}
+	return (*pn).val, true
+}
+
+// keyValue is a pair of key and value used while iterating.
+type keyValue[K, V any] struct {
+	key K
+	val V
+}
+
+// iterate returns an iterator that traverses the map.
+func (m *Map[K, V]) Iterate() *Iterator[K, V] {
+	sender, receiver := Ranger[keyValue[K, V]]()
+	var f func(*node[K, V]) bool
+	f = func(n *node[K, V]) bool {
+		if n == nil {
+			return true
+		}
+		// Stop the traversal if Send fails, which means that
+		// nothing is listening to the receiver.
+		return f(n.left) &&
+			sender.Send(context.Background(), keyValue[K, V]{n.key, n.val}) &&
+			f(n.right)
+	}
+	go func() {
+		f(m.root)
+		sender.Close()
+	}()
+	return &Iterator[K, V]{receiver}
+}
+
+// Iterator is used to iterate over the map.
+type Iterator[K, V any] struct {
+	r *Receiver[keyValue[K, V]]
+}
+
+// Next returns the next key and value pair, and a boolean that reports
+// whether they are valid. If not valid, we have reached the end of the map.
+func (it *Iterator[K, V]) Next() (K, V, bool) {
+	keyval, ok := it.r.Next(context.Background())
+	if !ok {
+		var zerok K
+		var zerov V
+		return zerok, zerov, false
+	}
+	return keyval.key, keyval.val, true
+}
+
+// Equal reports whether two slices are equal: the same length and all
+// elements equal. All floating point NaNs are considered equal.
+func SliceEqual[Elem comparable](s1, s2 []Elem) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if v1 != v2 {
+			isNaN := func(f Elem) bool { return f != f }
+			if !isNaN(v1) || !isNaN(v2) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Ranger returns a Sender and a Receiver. The Receiver provides a
+// Next method to retrieve values. The Sender provides a Send method
+// to send values and a Close method to stop sending values. The Next
+// method indicates when the Sender has been closed, and the Send
+// method indicates when the Receiver has been freed.
+//
+// This is a convenient way to exit a goroutine sending values when
+// the receiver stops reading them.
+func Ranger[Elem any]() (*Sender[Elem], *Receiver[Elem]) {
+	c := make(chan Elem)
+	d := make(chan struct{})
+	s := &Sender[Elem]{
+		values: c,
+		done:   d,
+	}
+	r := &Receiver[Elem]{
+		values: c,
+		done:   d,
+	}
+	runtime.SetFinalizer(r, (*Receiver[Elem]).finalize)
+	return s, r
+}
+
+// A Sender is used to send values to a Receiver.
+type Sender[Elem any] struct {
+	values chan<- Elem
+	done   <-chan struct{}
+}
+
+// Send sends a value to the receiver. It reports whether the value was sent.
+// The value will not be sent if the context is closed or the receiver
+// is freed.
+func (s *Sender[Elem]) Send(ctx context.Context, v Elem) bool {
+	select {
+	case <-ctx.Done():
+		return false
+	case s.values <- v:
+		return true
+	case <-s.done:
+		return false
+	}
+}
+
+// Close tells the receiver that no more values will arrive.
+// After Close is called, the Sender may no longer be used.
+func (s *Sender[Elem]) Close() {
+	close(s.values)
+}
+
+// A Receiver receives values from a Sender.
+type Receiver[Elem any] struct {
+	values <-chan Elem
+	done   chan<- struct{}
+}
+
+// Next returns the next value from the channel. The bool result indicates
+// whether the value is valid.
+func (r *Receiver[Elem]) Next(ctx context.Context) (v Elem, ok bool) {
+	select {
+	case <-ctx.Done():
+	case v, ok = <-r.values:
+	}
+	return v, ok
+}
+
+// finalize is a finalizer for the receiver.
+func (r *Receiver[Elem]) finalize() {
+	close(r.done)
+}
diff --git a/test/typeparam/orderedmapsimp.dir/main.go b/test/typeparam/orderedmapsimp.dir/main.go
new file mode 100644
index 00000000000..978f1e763c0
--- /dev/null
+++ b/test/typeparam/orderedmapsimp.dir/main.go
@@ -0,0 +1,64 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"bytes"
+	"fmt"
+)
+
+func TestMap() {
+	m := a.New[[]byte, int](bytes.Compare)
+
+	if _, found := m.Find([]byte("a")); found {
+		panic(fmt.Sprintf("unexpectedly found %q in empty map", []byte("a")))
+	}
+
+	for _, c := range []int{'a', 'c', 'b'} {
+		if !m.Insert([]byte(string(c)), c) {
+			panic(fmt.Sprintf("key %q unexpectedly already present", []byte(string(c))))
+		}
+	}
+	if m.Insert([]byte("c"), 'x') {
+		panic(fmt.Sprintf("key %q unexpectedly not present", []byte("c")))
+	}
+
+	if v, found := m.Find([]byte("a")); !found {
+		panic(fmt.Sprintf("did not find %q", []byte("a")))
+	} else if v != 'a' {
+		panic(fmt.Sprintf("key %q returned wrong value %c, expected %c", []byte("a"), v, 'a'))
+	}
+	if v, found := m.Find([]byte("c")); !found {
+		panic(fmt.Sprintf("did not find %q", []byte("c")))
+	} else if v != 'x' {
+		panic(fmt.Sprintf("key %q returned wrong value %c, expected %c", []byte("c"), v, 'x'))
+	}
+
+	if _, found := m.Find([]byte("d")); found {
+		panic(fmt.Sprintf("unexpectedly found %q", []byte("d")))
+	}
+
+	gather := func(it *a.Iterator[[]byte, int]) []int {
+		var r []int
+		for {
+			_, v, ok := it.Next()
+			if !ok {
+				return r
+			}
+			r = append(r, v)
+		}
+	}
+	got := gather(m.Iterate())
+	want := []int{'a', 'b', 'x'}
+	if !a.SliceEqual(got, want) {
+		panic(fmt.Sprintf("Iterate returned %v, want %v", got, want))
+	}
+
+}
+
+func main() {
+	TestMap()
+}
diff --git a/test/typeparam/orderedmapsimp.go b/test/typeparam/orderedmapsimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/orderedmapsimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/pair.go b/test/typeparam/pair.go
index 7faf083c89d..c1427b9c52c 100644
--- a/test/typeparam/pair.go
+++ b/test/typeparam/pair.go
@@ -24,7 +24,11 @@ func main() {
 	if got, want := unsafe.Sizeof(p.f2), uintptr(8); got != want {
 		panic(fmt.Sprintf("unexpected f2 size == %d, want %d", got, want))
 	}
-	type mypair struct { f1 int32; f2 int64 }
+
+	type mypair struct {
+		f1 int32
+		f2 int64
+	}
 	mp := mypair(p)
 	if mp.f1 != 1 || mp.f2 != 2 {
 		panic(fmt.Sprintf("mp == %#v, want %#v", mp, mypair{1, 2}))
diff --git a/test/typeparam/pairimp.dir/a.go b/test/typeparam/pairimp.dir/a.go
new file mode 100644
index 00000000000..a984fba37b6
--- /dev/null
+++ b/test/typeparam/pairimp.dir/a.go
@@ -0,0 +1,10 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Pair[F1, F2 any] struct {
+	Field1 F1
+	Field2 F2
+}
diff --git a/test/typeparam/pairimp.dir/main.go b/test/typeparam/pairimp.dir/main.go
new file mode 100644
index 00000000000..027fdd9ce76
--- /dev/null
+++ b/test/typeparam/pairimp.dir/main.go
@@ -0,0 +1,30 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"unsafe"
+)
+
+func main() {
+	p := a.Pair[int32, int64]{1, 2}
+	if got, want := unsafe.Sizeof(p.Field1), uintptr(4); got != want {
+		panic(fmt.Sprintf("unexpected f1 size == %d, want %d", got, want))
+	}
+	if got, want := unsafe.Sizeof(p.Field2), uintptr(8); got != want {
+		panic(fmt.Sprintf("unexpected f2 size == %d, want %d", got, want))
+	}
+
+	type mypair struct {
+		Field1 int32
+		Field2 int64
+	}
+	mp := mypair(p)
+	if mp.Field1 != 1 || mp.Field2 != 2 {
+		panic(fmt.Sprintf("mp == %#v, want %#v", mp, mypair{1, 2}))
+	}
+}
diff --git a/test/typeparam/pairimp.go b/test/typeparam/pairimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/pairimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/sets.go b/test/typeparam/sets.go
index 258514489e1..4f07b590e36 100644
--- a/test/typeparam/sets.go
+++ b/test/typeparam/sets.go
@@ -160,7 +160,7 @@ func TestSet() {
 	vals := s1.Values()
 	sort.Ints(vals)
 	w1 := []int{1, 2, 3, 4}
-	if !_SliceEqual(vals,  w1) {
+	if !_SliceEqual(vals, w1) {
 		panic(fmt.Sprintf("(%v).Values() == %v, want %v", s1, vals, w1))
 	}
 }
diff --git a/test/typeparam/setsimp.dir/a.go b/test/typeparam/setsimp.dir/a.go
new file mode 100644
index 00000000000..92449ce9562
--- /dev/null
+++ b/test/typeparam/setsimp.dir/a.go
@@ -0,0 +1,128 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+// SliceEqual reports whether two slices are equal: the same length and all
+// elements equal. All floating point NaNs are considered equal.
+func SliceEqual[Elem comparable](s1, s2 []Elem) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if v1 != v2 {
+			isNaN := func(f Elem) bool { return f != f }
+			if !isNaN(v1) || !isNaN(v2) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// A Set is a set of elements of some type.
+type Set[Elem comparable] struct {
+	m map[Elem]struct{}
+}
+
+// Make makes a new set.
+func Make[Elem comparable]() Set[Elem] {
+	return Set[Elem]{m: make(map[Elem]struct{})}
+}
+
+// Add adds an element to a set.
+func (s Set[Elem]) Add(v Elem) {
+	s.m[v] = struct{}{}
+}
+
+// Delete removes an element from a set. If the element is not present
+// in the set, this does nothing.
+func (s Set[Elem]) Delete(v Elem) {
+	delete(s.m, v)
+}
+
+// Contains reports whether v is in the set.
+func (s Set[Elem]) Contains(v Elem) bool {
+	_, ok := s.m[v]
+	return ok
+}
+
+// Len returns the number of elements in the set.
+func (s Set[Elem]) Len() int {
+	return len(s.m)
+}
+
+// Values returns the values in the set.
+// The values will be in an indeterminate order.
+func (s Set[Elem]) Values() []Elem {
+	r := make([]Elem, 0, len(s.m))
+	for v := range s.m {
+		r = append(r, v)
+	}
+	return r
+}
+
+// Equal reports whether two sets contain the same elements.
+func Equal[Elem comparable](s1, s2 Set[Elem]) bool {
+	if len(s1.m) != len(s2.m) {
+		return false
+	}
+	for v1 := range s1.m {
+		if !s2.Contains(v1) {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy returns a copy of s.
+func (s Set[Elem]) Copy() Set[Elem] {
+	r := Set[Elem]{m: make(map[Elem]struct{}, len(s.m))}
+	for v := range s.m {
+		r.m[v] = struct{}{}
+	}
+	return r
+}
+
+// AddSet adds all the elements of s2 to s.
+func (s Set[Elem]) AddSet(s2 Set[Elem]) {
+	for v := range s2.m {
+		s.m[v] = struct{}{}
+	}
+}
+
+// SubSet removes all elements in s2 from s.
+// Values in s2 that are not in s are ignored.
+func (s Set[Elem]) SubSet(s2 Set[Elem]) {
+	for v := range s2.m {
+		delete(s.m, v)
+	}
+}
+
+// Intersect removes all elements from s that are not present in s2.
+// Values in s2 that are not in s are ignored.
+func (s Set[Elem]) Intersect(s2 Set[Elem]) {
+	for v := range s.m {
+		if !s2.Contains(v) {
+			delete(s.m, v)
+		}
+	}
+}
+
+// Iterate calls f on every element in the set.
+func (s Set[Elem]) Iterate(f func(Elem)) {
+	for v := range s.m {
+		f(v)
+	}
+}
+
+// Filter deletes any elements from s for which f returns false.
+func (s Set[Elem]) Filter(f func(Elem) bool) {
+	for v := range s.m {
+		if !f(v) {
+			delete(s.m, v)
+		}
+	}
+}
diff --git a/test/typeparam/setsimp.dir/main.go b/test/typeparam/setsimp.dir/main.go
new file mode 100644
index 00000000000..8fd16571439
--- /dev/null
+++ b/test/typeparam/setsimp.dir/main.go
@@ -0,0 +1,156 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"sort"
+)
+
+func TestSet() {
+	s1 := a.Make[int]()
+	if got := s1.Len(); got != 0 {
+		panic(fmt.Sprintf("Len of empty set = %d, want 0", got))
+	}
+	s1.Add(1)
+	s1.Add(1)
+	s1.Add(1)
+	if got := s1.Len(); got != 1 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got))
+	}
+	s1.Add(2)
+	s1.Add(3)
+	s1.Add(4)
+	if got := s1.Len(); got != 4 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 4", s1, got))
+	}
+	if !s1.Contains(1) {
+		panic(fmt.Sprintf("(%v).Contains(1) == false, want true", s1))
+	}
+	if s1.Contains(5) {
+		panic(fmt.Sprintf("(%v).Contains(5) == true, want false", s1))
+	}
+	vals := s1.Values()
+	sort.Ints(vals)
+	w1 := []int{1, 2, 3, 4}
+	if !a.SliceEqual(vals, w1) {
+		panic(fmt.Sprintf("(%v).Values() == %v, want %v", s1, vals, w1))
+	}
+}
+
+func TestEqual() {
+	s1 := a.Make[string]()
+	s2 := a.Make[string]()
+	if !a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s1, s2))
+	}
+	s1.Add("hello")
+	s1.Add("world")
+	if got := s1.Len(); got != 2 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 2", s1, got))
+	}
+	if a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", s1, s2))
+	}
+}
+
+func TestCopy() {
+	s1 := a.Make[float64]()
+	s1.Add(0)
+	s2 := s1.Copy()
+	if !a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s1, s2))
+	}
+	s1.Add(1)
+	if a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", s1, s2))
+	}
+}
+
+func TestAddSet() {
+	s1 := a.Make[int]()
+	s1.Add(1)
+	s1.Add(2)
+	s2 := a.Make[int]()
+	s2.Add(2)
+	s2.Add(3)
+	s1.AddSet(s2)
+	if got := s1.Len(); got != 3 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 3", s1, got))
+	}
+	s2.Add(1)
+	if !a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s1, s2))
+	}
+}
+
+func TestSubSet() {
+	s1 := a.Make[int]()
+	s1.Add(1)
+	s1.Add(2)
+	s2 := a.Make[int]()
+	s2.Add(2)
+	s2.Add(3)
+	s1.SubSet(s2)
+	if got := s1.Len(); got != 1 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got))
+	}
+	if vals, want := s1.Values(), []int{1}; !a.SliceEqual(vals, want) {
+		panic(fmt.Sprintf("after SubSet got %v, want %v", vals, want))
+	}
+}
+
+func TestIntersect() {
+	s1 := a.Make[int]()
+	s1.Add(1)
+	s1.Add(2)
+	s2 := a.Make[int]()
+	s2.Add(2)
+	s2.Add(3)
+	s1.Intersect(s2)
+	if got := s1.Len(); got != 1 {
+		panic(fmt.Sprintf("(%v).Len() == %d, want 1", s1, got))
+	}
+	if vals, want := s1.Values(), []int{2}; !a.SliceEqual(vals, want) {
+		panic(fmt.Sprintf("after Intersect got %v, want %v", vals, want))
+	}
+}
+
+func TestIterate() {
+	s1 := a.Make[int]()
+	s1.Add(1)
+	s1.Add(2)
+	s1.Add(3)
+	s1.Add(4)
+	tot := 0
+	s1.Iterate(func(i int) { tot += i })
+	if tot != 10 {
+		panic(fmt.Sprintf("total of %v == %d, want 10", s1, tot))
+	}
+}
+
+func TestFilter() {
+	s1 := a.Make[int]()
+	s1.Add(1)
+	s1.Add(2)
+	s1.Add(3)
+	s1.Filter(func(v int) bool { return v%2 == 0 })
+	if vals, want := s1.Values(), []int{2}; !a.SliceEqual(vals, want) {
+		panic(fmt.Sprintf("after Filter got %v, want %v", vals, want))
+	}
+
+}
+
+func main() {
+	TestSet()
+	TestEqual()
+	TestCopy()
+	TestAddSet()
+	TestSubSet()
+	TestIntersect()
+	TestIterate()
+	TestFilter()
+}
diff --git a/test/typeparam/setsimp.go b/test/typeparam/setsimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/setsimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/settable.go b/test/typeparam/settable.go
index 588166da858..99455e93fa1 100644
--- a/test/typeparam/settable.go
+++ b/test/typeparam/settable.go
@@ -13,13 +13,13 @@ import (
 
 // Various implementations of fromStrings().
 
-type _Setter[B any] interface {
+type Setter[B any] interface {
 	Set(string)
 	type *B
 }
 
 // Takes two type parameters where PT = *T
-func fromStrings1[T any, PT _Setter[T]](s []string) []T {
+func fromStrings1[T any, PT Setter[T]](s []string) []T {
 	result := make([]T, len(s))
 	for i, v := range s {
 		// The type of &result[i] is *T which is in the type list
@@ -31,7 +31,7 @@ func fromStrings1[T any, PT _Setter[T]](s []string) []T {
 	return result
 }
 
-func fromStrings1a[T any, PT _Setter[T]](s []string) []PT {
+func fromStrings1a[T any, PT Setter[T]](s []string) []PT {
 	result := make([]PT, len(s))
 	for i, v := range s {
 		// The type new(T) is *T which is in the type list
@@ -44,7 +44,6 @@ func fromStrings1a[T any, PT _Setter[T]](s []string) []PT {
 	return result
 }
 
-
 // Takes one type parameter and a set function
 func fromStrings2[T any](s []string, set func(*T, string)) []T {
 	results := make([]T, len(s))
@@ -54,12 +53,12 @@ func fromStrings2[T any](s []string, set func(*T, string)) []T {
 	return results
 }
 
-type _Setter2 interface {
+type Setter2 interface {
 	Set(string)
 }
 
 // Takes only one type parameter, but causes a panic (see below)
-func fromStrings3[T _Setter2](s []string) []T {
+func fromStrings3[T Setter2](s []string) []T {
 	results := make([]T, len(s))
 	for i, v := range s {
 		// Panics if T is a pointer type because receiver is T(nil).
diff --git a/test/typeparam/shape1.go b/test/typeparam/shape1.go
new file mode 100644
index 00000000000..de1ea65ed22
--- /dev/null
+++ b/test/typeparam/shape1.go
@@ -0,0 +1,50 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface {
+	foo() int
+}
+
+// There should be one instantiation of f for both squarer and doubler.
+// Similarly, there should be one instantiation of f for both *incrementer and *decrementer.
+func f[T I](x T) int {
+	return x.foo()
+}
+
+type squarer int
+
+func (x squarer) foo() int {
+	return int(x*x)
+}
+
+type doubler int
+
+func (x doubler) foo() int {
+	return int(2*x)
+}
+
+type incrementer int16
+
+func (x *incrementer) foo() int {
+	return int(*x+1)
+}
+
+type decrementer int32
+
+func (x *decrementer) foo() int{
+	return int(*x-1)
+}
+
+func main() {
+	println(f(squarer(5)))
+	println(f(doubler(5)))
+	var i incrementer = 5
+	println(f(&i))
+	var d decrementer = 5
+	println(f(&d))
+}
diff --git a/test/typeparam/shape1.out b/test/typeparam/shape1.out
new file mode 100644
index 00000000000..da9a12ded55
--- /dev/null
+++ b/test/typeparam/shape1.out
@@ -0,0 +1,4 @@
+25
+10
+6
+4
diff --git a/test/typeparam/sliceimp.dir/a.go b/test/typeparam/sliceimp.dir/a.go
new file mode 100644
index 00000000000..da12e9f9fc9
--- /dev/null
+++ b/test/typeparam/sliceimp.dir/a.go
@@ -0,0 +1,141 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// Max returns the maximum of two values of some ordered type.
+func Max[T Ordered](a, b T) T {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// Min returns the minimum of two values of some ordered type.
+func Min[T Ordered](a, b T) T {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+// Equal reports whether two slices are equal: the same length and all
+// elements equal. All floating point NaNs are considered equal.
+func Equal[Elem comparable](s1, s2 []Elem) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if v1 != v2 {
+			isNaN := func(f Elem) bool { return f != f }
+			if !isNaN(v1) || !isNaN(v2) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// EqualFn reports whether two slices are equal using a comparision
+// function on each element.
+func EqualFn[Elem any](s1, s2 []Elem, eq func(Elem, Elem) bool) bool {
+	if len(s1) != len(s2) {
+		return false
+	}
+	for i, v1 := range s1 {
+		v2 := s2[i]
+		if !eq(v1, v2) {
+			return false
+		}
+	}
+	return true
+}
+
+// Map turns a []Elem1 to a []Elem2 using a mapping function.
+func Map[Elem1, Elem2 any](s []Elem1, f func(Elem1) Elem2) []Elem2 {
+	r := make([]Elem2, len(s))
+	for i, v := range s {
+		r[i] = f(v)
+	}
+	return r
+}
+
+// Reduce reduces a []Elem1 to a single value of type Elem2 using
+// a reduction function.
+func Reduce[Elem1, Elem2 any](s []Elem1, initializer Elem2, f func(Elem2, Elem1) Elem2) Elem2 {
+	r := initializer
+	for _, v := range s {
+		r = f(r, v)
+	}
+	return r
+}
+
+// Filter filters values from a slice using a filter function.
+func Filter[Elem any](s []Elem, f func(Elem) bool) []Elem {
+	var r []Elem
+	for _, v := range s {
+		if f(v) {
+			r = append(r, v)
+		}
+	}
+	return r
+}
+
+// Max returns the maximum element in a slice of some ordered type.
+// If the slice is empty it returns the zero value of the element type.
+func SliceMax[Elem Ordered](s []Elem) Elem {
+	if len(s) == 0 {
+		var zero Elem
+		return zero
+	}
+	return Reduce(s[1:], s[0], Max[Elem])
+}
+
+// Min returns the minimum element in a slice of some ordered type.
+// If the slice is empty it returns the zero value of the element type.
+func SliceMin[Elem Ordered](s []Elem) Elem {
+	if len(s) == 0 {
+		var zero Elem
+		return zero
+	}
+	return Reduce(s[1:], s[0], Min[Elem])
+}
+
+// Append adds values to the end of a slice, returning a new slice.
+// This is like the predeclared append function; it's an example
+// of how to write it using generics. We used to write code like
+// this before append was added to the language, but we had to write
+// a separate copy for each type.
+func Append[T any](s []T, t ...T) []T {
+	lens := len(s)
+	tot := lens + len(t)
+	if tot <= cap(s) {
+		s = s[:tot]
+	} else {
+		news := make([]T, tot, tot+tot/2)
+		Copy(news, s)
+		s = news
+	}
+	Copy(s[lens:tot], t)
+	return s
+}
+
+// Copy copies values from t to s, stopping when either slice is full,
+// returning the number of values copied. This is like the predeclared
+// copy function; it's an example of how to write it using generics.
+func Copy[T any](s, t []T) int {
+	i := 0
+	for ; i < len(s) && i < len(t); i++ {
+		s[i] = t[i]
+	}
+	return i
+}
diff --git a/test/typeparam/sliceimp.dir/main.go b/test/typeparam/sliceimp.dir/main.go
new file mode 100644
index 00000000000..0f79e10018b
--- /dev/null
+++ b/test/typeparam/sliceimp.dir/main.go
@@ -0,0 +1,179 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"math"
+	"strings"
+)
+
+type Integer interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+func TestEqual() {
+	s1 := []int{1, 2, 3}
+	if !a.Equal(s1, s1) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s1, s1))
+	}
+	s2 := []int{1, 2, 3}
+	if !a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s1, s2))
+	}
+	s2 = append(s2, 4)
+	if a.Equal(s1, s2) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = true, want false", s1, s2))
+	}
+
+	s3 := []float64{1, 2, math.NaN()}
+	if !a.Equal(s3, s3) {
+		panic(fmt.Sprintf("a.Equal(%v, %v) = false, want true", s3, s3))
+	}
+
+	if a.Equal(s1, nil) {
+		panic(fmt.Sprintf("a.Equal(%v, nil) = true, want false", s1))
+	}
+	if a.Equal(nil, s1) {
+		panic(fmt.Sprintf("a.Equal(nil, %v) = true, want false", s1))
+	}
+	if !a.Equal(s1[:0], nil) {
+		panic(fmt.Sprintf("a.Equal(%v, nil = false, want true", s1[:0]))
+	}
+}
+
+func offByOne[Elem Integer](a, b Elem) bool {
+	return a == b+1 || a == b-1
+}
+
+func TestEqualFn() {
+	s1 := []int{1, 2, 3}
+	s2 := []int{2, 3, 4}
+	if a.EqualFn(s1, s1, offByOne[int]) {
+		panic(fmt.Sprintf("a.EqualFn(%v, %v, offByOne) = true, want false", s1, s1))
+	}
+	if !a.EqualFn(s1, s2, offByOne[int]) {
+		panic(fmt.Sprintf("a.EqualFn(%v, %v, offByOne) = false, want true", s1, s2))
+	}
+
+	if !a.EqualFn(s1[:0], nil, offByOne[int]) {
+		panic(fmt.Sprintf("a.EqualFn(%v, nil, offByOne) = false, want true", s1[:0]))
+	}
+
+	s3 := []string{"a", "b", "c"}
+	s4 := []string{"A", "B", "C"}
+	if !a.EqualFn(s3, s4, strings.EqualFold) {
+		panic(fmt.Sprintf("a.EqualFn(%v, %v, strings.EqualFold) = false, want true", s3, s4))
+	}
+}
+
+func TestMap() {
+	s1 := []int{1, 2, 3}
+	s2 := a.Map(s1, func(i int) float64 { return float64(i) * 2.5 })
+	if want := []float64{2.5, 5, 7.5}; !a.Equal(s2, want) {
+		panic(fmt.Sprintf("a.Map(%v, ...) = %v, want %v", s1, s2, want))
+	}
+
+	s3 := []string{"Hello", "World"}
+	s4 := a.Map(s3, strings.ToLower)
+	if want := []string{"hello", "world"}; !a.Equal(s4, want) {
+		panic(fmt.Sprintf("a.Map(%v, strings.ToLower) = %v, want %v", s3, s4, want))
+	}
+
+	s5 := a.Map(nil, func(i int) int { return i })
+	if len(s5) != 0 {
+		panic(fmt.Sprintf("a.Map(nil, identity) = %v, want empty slice", s5))
+	}
+}
+
+func TestReduce() {
+	s1 := []int{1, 2, 3}
+	r := a.Reduce(s1, 0, func(f float64, i int) float64 { return float64(i)*2.5 + f })
+	if want := 15.0; r != want {
+		panic(fmt.Sprintf("a.Reduce(%v, 0, ...) = %v, want %v", s1, r, want))
+	}
+
+	if got := a.Reduce(nil, 0, func(i, j int) int { return i + j }); got != 0 {
+		panic(fmt.Sprintf("a.Reduce(nil, 0, add) = %v, want 0", got))
+	}
+}
+
+func TestFilter() {
+	s1 := []int{1, 2, 3}
+	s2 := a.Filter(s1, func(i int) bool { return i%2 == 0 })
+	if want := []int{2}; !a.Equal(s2, want) {
+		panic(fmt.Sprintf("a.Filter(%v, even) = %v, want %v", s1, s2, want))
+	}
+
+	if s3 := a.Filter(s1[:0], func(i int) bool { return true }); len(s3) > 0 {
+		panic(fmt.Sprintf("a.Filter(%v, identity) = %v, want empty slice", s1[:0], s3))
+	}
+}
+
+func TestMax() {
+	s1 := []int{1, 2, 3, -5}
+	if got, want := a.SliceMax(s1), 3; got != want {
+		panic(fmt.Sprintf("a.Max(%v) = %d, want %d", s1, got, want))
+	}
+
+	s2 := []string{"aaa", "a", "aa", "aaaa"}
+	if got, want := a.SliceMax(s2), "aaaa"; got != want {
+		panic(fmt.Sprintf("a.Max(%v) = %q, want %q", s2, got, want))
+	}
+
+	if got, want := a.SliceMax(s2[:0]), ""; got != want {
+		panic(fmt.Sprintf("a.Max(%v) = %q, want %q", s2[:0], got, want))
+	}
+}
+
+func TestMin() {
+	s1 := []int{1, 2, 3, -5}
+	if got, want := a.SliceMin(s1), -5; got != want {
+		panic(fmt.Sprintf("a.Min(%v) = %d, want %d", s1, got, want))
+	}
+
+	s2 := []string{"aaa", "a", "aa", "aaaa"}
+	if got, want := a.SliceMin(s2), "a"; got != want {
+		panic(fmt.Sprintf("a.Min(%v) = %q, want %q", s2, got, want))
+	}
+
+	if got, want := a.SliceMin(s2[:0]), ""; got != want {
+		panic(fmt.Sprintf("a.Min(%v) = %q, want %q", s2[:0], got, want))
+	}
+}
+
+func TestAppend() {
+	s := []int{1, 2, 3}
+	s = a.Append(s, 4, 5, 6)
+	want := []int{1, 2, 3, 4, 5, 6}
+	if !a.Equal(s, want) {
+		panic(fmt.Sprintf("after a.Append got %v, want %v", s, want))
+	}
+}
+
+func TestCopy() {
+	s1 := []int{1, 2, 3}
+	s2 := []int{4, 5}
+	if got := a.Copy(s1, s2); got != 2 {
+		panic(fmt.Sprintf("a.Copy returned %d, want 2", got))
+	}
+	want := []int{4, 5, 3}
+	if !a.Equal(s1, want) {
+		panic(fmt.Sprintf("after a.Copy got %v, want %v", s1, want))
+	}
+}
+func main() {
+	TestEqual()
+	TestEqualFn()
+	TestMap()
+	TestReduce()
+	TestFilter()
+	TestMax()
+	TestMin()
+	TestAppend()
+	TestCopy()
+}
diff --git a/test/typeparam/sliceimp.go b/test/typeparam/sliceimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/sliceimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/slices.go b/test/typeparam/slices.go
index 149199eb649..b5e8e0c6063 100644
--- a/test/typeparam/slices.go
+++ b/test/typeparam/slices.go
@@ -15,31 +15,31 @@ import (
 )
 
 type Ordered interface {
-        type int, int8, int16, int32, int64,
-                uint, uint8, uint16, uint32, uint64, uintptr,
-                float32, float64,
-                string
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
 }
 
 type Integer interface {
-        type int, int8, int16, int32, int64,
-                uint, uint8, uint16, uint32, uint64, uintptr
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
 }
 
 // Max returns the maximum of two values of some ordered type.
 func _Max[T Ordered](a, b T) T {
-        if a > b {
-                return a
-        }
-        return b
+	if a > b {
+		return a
+	}
+	return b
 }
 
 // Min returns the minimum of two values of some ordered type.
 func _Min[T Ordered](a, b T) T {
-        if a < b {
-                return a
-        }
-        return b
+	if a < b {
+		return a
+	}
+	return b
 }
 
 // _Equal reports whether two slices are equal: the same length and all
@@ -136,7 +136,7 @@ func _Append[T any](s []T, t ...T) []T {
 	if tot <= cap(s) {
 		s = s[:tot]
 	} else {
-		news := make([]T, tot, tot + tot/2)
+		news := make([]T, tot, tot+tot/2)
 		_Copy(news, s)
 		s = news
 	}
@@ -156,37 +156,37 @@ func _Copy[T any](s, t []T) int {
 }
 
 func TestEqual() {
-        s1 := []int{1, 2, 3}
-        if !_Equal(s1, s1) {
-                panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s1))
-        }
-        s2 := []int{1, 2, 3}
-        if !_Equal(s1, s2) {
-                panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2))
-        }
-        s2 = append(s2, 4)
-        if _Equal(s1, s2) {
-                panic(fmt.Sprintf("_Equal(%v, %v) = true, want false", s1, s2))
-        }
+	s1 := []int{1, 2, 3}
+	if !_Equal(s1, s1) {
+		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s1))
+	}
+	s2 := []int{1, 2, 3}
+	if !_Equal(s1, s2) {
+		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2))
+	}
+	s2 = append(s2, 4)
+	if _Equal(s1, s2) {
+		panic(fmt.Sprintf("_Equal(%v, %v) = true, want false", s1, s2))
+	}
 
-        s3 := []float64{1, 2, math.NaN()}
-        if !_Equal(s3, s3) {
-                panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s3, s3))
-        }
+	s3 := []float64{1, 2, math.NaN()}
+	if !_Equal(s3, s3) {
+		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s3, s3))
+	}
 
-        if _Equal(s1, nil) {
-                panic(fmt.Sprintf("_Equal(%v, nil) = true, want false", s1))
-        }
-        if _Equal(nil, s1) {
-                panic(fmt.Sprintf("_Equal(nil, %v) = true, want false", s1))
-        }
-        if !_Equal(s1[:0], nil) {
-                panic(fmt.Sprintf("_Equal(%v, nil = false, want true", s1[:0]))
-        }
+	if _Equal(s1, nil) {
+		panic(fmt.Sprintf("_Equal(%v, nil) = true, want false", s1))
+	}
+	if _Equal(nil, s1) {
+		panic(fmt.Sprintf("_Equal(nil, %v) = true, want false", s1))
+	}
+	if !_Equal(s1[:0], nil) {
+		panic(fmt.Sprintf("_Equal(%v, nil = false, want true", s1[:0]))
+	}
 }
 
 func offByOne[Elem Integer](a, b Elem) bool {
-	return a == b + 1 || a == b - 1
+	return a == b+1 || a == b-1
 }
 
 func TestEqualFn() {
@@ -231,12 +231,12 @@ func TestMap() {
 
 func TestReduce() {
 	s1 := []int{1, 2, 3}
-	r := _Reduce(s1, 0, func(f float64, i int) float64 { return float64(i) * 2.5 + f })
+	r := _Reduce(s1, 0, func(f float64, i int) float64 { return float64(i)*2.5 + f })
 	if want := 15.0; r != want {
 		panic(fmt.Sprintf("_Reduce(%v, 0, ...) = %v, want %v", s1, r, want))
 	}
 
-	if got := _Reduce(nil, 0, func(i, j int) int { return i + j}); got != 0 {
+	if got := _Reduce(nil, 0, func(i, j int) int { return i + j }); got != 0 {
 		panic(fmt.Sprintf("_Reduce(nil, 0, add) = %v, want 0", got))
 	}
 }
diff --git a/test/typeparam/smallest.go b/test/typeparam/smallest.go
index 63dd9ddb700..af1d72d8992 100644
--- a/test/typeparam/smallest.go
+++ b/test/typeparam/smallest.go
@@ -11,13 +11,13 @@ import (
 )
 
 type Ordered interface {
-	type int, int8, int16, int32, int64,
-		uint, uint8, uint16, uint32, uint64, uintptr,
-		float32, float64,
-		string
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
 }
 
-func smallest[T Ordered](s []T) T {
+func Smallest[T Ordered](s []T) T {
 	r := s[0] // panics if slice is empty
 	for _, v := range s[1:] {
 		if v < r {
@@ -32,11 +32,11 @@ func main() {
 	vec2 := []string{"abc", "def", "aaa"}
 
 	want1 := 1.2
-	if got := smallest(vec1); got != want1 {
+	if got := Smallest(vec1); got != want1 {
 		panic(fmt.Sprintf("got %d, want %d", got, want1))
 	}
 	want2 := "aaa"
-	if got := smallest(vec2); got != want2 {
+	if got := Smallest(vec2); got != want2 {
 		panic(fmt.Sprintf("got %d, want %d", got, want2))
 	}
 }
diff --git a/test/typeparam/smoketest.go b/test/typeparam/smoketest.go
index b7d6201b2c1..5243dc5c3c1 100644
--- a/test/typeparam/smoketest.go
+++ b/test/typeparam/smoketest.go
@@ -9,9 +9,9 @@
 package smoketest
 
 // type parameters for functions
-func f1[P any]()
-func f2[P1, P2 any, P3 any]()
-func f3[P interface{}](x P, y T1[int])
+func f1[P any]() {}
+func f2[P1, P2 any, P3 any]() {}
+func f3[P interface{}](x P, y T1[int]) {}
 
 // function instantiations
 var _ = f1[int]
@@ -29,15 +29,15 @@ type _ T2[int, string, struct{}]
 type _ T3[bool]
 
 // methods
-func (T1[P]) m1() {}
-func (T1[_]) m2() {}
+func (T1[P]) m1()           {}
+func (T1[_]) m2()           {}
 func (x T2[P1, P2, P3]) m() {}
 
 // type lists
 type _ interface {
 	m1()
 	m2()
-	type int, float32, string
+	int | float32 | string
 	m3()
 }
 
diff --git a/test/typeparam/stringable.go b/test/typeparam/stringable.go
index 9340a3b10a9..855a1edb3bf 100644
--- a/test/typeparam/stringable.go
+++ b/test/typeparam/stringable.go
@@ -16,11 +16,11 @@ type Stringer interface {
 	String() string
 }
 
-// stringableList is a slice of some type, where the type
+// StringableList is a slice of some type, where the type
 // must have a String method.
-type stringableList[T Stringer] []T
+type StringableList[T Stringer] []T
 
-func (s stringableList[T]) String() string {
+func (s StringableList[T]) String() string {
 	var sb strings.Builder
 	for i, v := range s {
 		if i > 0 {
@@ -38,9 +38,9 @@ func (a myint) String() string {
 }
 
 func main() {
-	v := stringableList[myint]{ myint(1), myint(2) }
+	v := StringableList[myint]{myint(1), myint(2)}
 
 	if got, want := v.String(), "1, 2"; got != want {
-                panic(fmt.Sprintf("got %s, want %s", got, want))
+		panic(fmt.Sprintf("got %s, want %s", got, want))
 	}
 }
diff --git a/test/typeparam/stringerimp.dir/a.go b/test/typeparam/stringerimp.dir/a.go
new file mode 100644
index 00000000000..3f70937ff55
--- /dev/null
+++ b/test/typeparam/stringerimp.dir/a.go
@@ -0,0 +1,16 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Stringer interface {
+	String() string
+}
+
+func Stringify[T Stringer](s []T) (ret []string) {
+	for _, v := range s {
+		ret = append(ret, v.String())
+	}
+	return ret
+}
diff --git a/test/typeparam/stringerimp.dir/main.go b/test/typeparam/stringerimp.dir/main.go
new file mode 100644
index 00000000000..e30bdf1abeb
--- /dev/null
+++ b/test/typeparam/stringerimp.dir/main.go
@@ -0,0 +1,38 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+type myint int
+
+func (i myint) String() string {
+	return strconv.Itoa(int(i))
+}
+
+func main() {
+	x := []myint{myint(1), myint(2), myint(3)}
+
+	got := a.Stringify(x)
+	want := []string{"1", "2", "3"}
+	if !reflect.DeepEqual(got, want) {
+		panic(fmt.Sprintf("got %s, want %s", got, want))
+	}
+
+	m1 := myint(1)
+	m2 := myint(2)
+	m3 := myint(3)
+	y := []*myint{&m1, &m2, &m3}
+	got2 := a.Stringify(y)
+	want2 := []string{"1", "2", "3"}
+	if !reflect.DeepEqual(got2, want2) {
+		panic(fmt.Sprintf("got %s, want %s", got2, want2))
+	}
+}
diff --git a/test/typeparam/stringerimp.go b/test/typeparam/stringerimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/stringerimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/struct.go b/test/typeparam/struct.go
index 98f0fcd8888..ad1b41ddac4 100644
--- a/test/typeparam/struct.go
+++ b/test/typeparam/struct.go
@@ -10,40 +10,40 @@ import (
 	"fmt"
 )
 
-type _E[T any] struct {
+type E[T any] struct {
 	v T
 }
 
-type _S1 struct {
-	_E[int]
+type S1 struct {
+	E[int]
 	v string
 }
 
-type _Eint = _E[int]
-type _Ebool = _E[bool]
+type Eint = E[int]
+type Ebool = E[bool]
 
-type _S2 struct {
-	_Eint
-	_Ebool
+type S2 struct {
+	Eint
+	Ebool
 	v string
 }
 
-type _S3 struct {
-	*_E[int]
+type S3 struct {
+	*E[int]
 }
 
 func main() {
-	s1 := _S1{_Eint{2}, "foo"}
-	if got, want := s1._E.v, 2; got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+	s1 := S1{Eint{2}, "foo"}
+	if got, want := s1.E.v, 2; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
-	s2 := _S2{_Eint{3}, _Ebool{true}, "foo"}
-	if got, want := s2._Eint.v, 3; got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+	s2 := S2{Eint{3}, Ebool{true}, "foo"}
+	if got, want := s2.Eint.v, 3; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
-	var s3 _S3
-	s3._E = &_Eint{4}
-	if got, want := s3._E.v, 4; got != want {
-                panic(fmt.Sprintf("got %d, want %d", got, want))
+	var s3 S3
+	s3.E = &Eint{4}
+	if got, want := s3.E.v, 4; got != want {
+		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 }
diff --git a/test/typeparam/subdict.go b/test/typeparam/subdict.go
new file mode 100644
index 00000000000..b4e84baf8a7
--- /dev/null
+++ b/test/typeparam/subdict.go
@@ -0,0 +1,41 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test cases where a main dictionary is needed inside a generic function/method, because
+// we are calling a method on a fully-instantiated type or a fully-instantiated function.
+// (probably not common situations, of course)
+
+package main
+
+import (
+	"fmt"
+)
+
+type value[T comparable] struct {
+	val T
+}
+
+func (v *value[T]) test(def T) bool {
+	return (v.val == def)
+}
+
+func (v *value[T]) get(def T) T {
+	var c value[int]
+	if c.test(32) {
+		return def
+	} else if v.test(def) {
+		return def
+	} else {
+		return v.val
+	}
+}
+
+func main() {
+	var s value[string]
+	if got, want := s.get("ab"), ""; got != want {
+		panic(fmt.Sprintf("get() == %d, want %d", got, want))
+	}
+}
diff --git a/test/typeparam/sum.go b/test/typeparam/sum.go
index f0f5e6aa075..d444e007a3a 100644
--- a/test/typeparam/sum.go
+++ b/test/typeparam/sum.go
@@ -10,7 +10,7 @@ import (
 	"fmt"
 )
 
-func sum[T interface{ type int, float64 }](vec []T) T {
+func Sum[T interface{ int | float64 }](vec []T) T {
 	var sum T
 	for _, elt := range vec {
 		sum = sum + elt
@@ -18,7 +18,7 @@ func sum[T interface{ type int, float64 }](vec []T) T {
 	return sum
 }
 
-func abs(f float64) float64 {
+func Abs(f float64) float64 {
 	if f < 0.0 {
 		return -f
 	}
@@ -28,23 +28,23 @@ func abs(f float64) float64 {
 func main() {
 	vec1 := []int{3, 4}
 	vec2 := []float64{5.8, 9.6}
-	got := sum[int](vec1)
+	got := Sum[int](vec1)
 	want := vec1[0] + vec1[1]
 	if got != want {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
-	got = sum(vec1)
+	got = Sum(vec1)
 	if want != got {
 		panic(fmt.Sprintf("got %d, want %d", got, want))
 	}
 
 	fwant := vec2[0] + vec2[1]
-	fgot := sum[float64](vec2)
-	if abs(fgot - fwant) > 1e-10 {
+	fgot := Sum[float64](vec2)
+	if Abs(fgot-fwant) > 1e-10 {
 		panic(fmt.Sprintf("got %f, want %f", fgot, fwant))
 	}
-	fgot = sum(vec2)
-	if abs(fgot - fwant) > 1e-10 {
+	fgot = Sum(vec2)
+	if Abs(fgot-fwant) > 1e-10 {
 		panic(fmt.Sprintf("got %f, want %f", fgot, fwant))
 	}
 }
diff --git a/test/typeparam/tparam1.go b/test/typeparam/tparam1.go
index 70439333269..698877a6f00 100644
--- a/test/typeparam/tparam1.go
+++ b/test/typeparam/tparam1.go
@@ -10,33 +10,33 @@ package tparam1
 
 // The predeclared identifier "any" is only visible as a constraint
 // in a type parameter list.
-var _ any // ERROR "undefined"
-func _(_ any) // ERROR "undefined"
-type _[_ any /* ok here */ ] struct{}
+var _ any     // ERROR "cannot use any outside constraint position"
+func _(_ any) // ERROR "cannot use any outside constraint position"
+type _[_ any /* ok here */] struct{}
 
 const N = 10
 
 type (
-        _[] struct{} // slice
-        _[N] struct{} // array
-        _[T any] struct{}
-        _[T, T any] struct{} // ERROR "T redeclared"
-        _[T1, T2 any, T3 any] struct{}
+	_                     []struct{}  // slice
+	_                     [N]struct{} // array
+	_[T any]              struct{}
+	_[T, T any]           struct{} // ERROR "T redeclared"
+	_[T1, T2 any, T3 any] struct{}
 )
 
-func _[T any]()
-func _[T, T any]() // ERROR "T redeclared"
-func _[T1, T2 any](x T1) T2
+func _[T any]() {}
+func _[T, T any]() {} // ERROR "T redeclared"
+func _[T1, T2 any](x T1) T2 { panic(0) }
 
 // Type parameters are visible from opening [ to end of function.
 type C interface{}
 
-func _[T interface{}]()
-func _[T C]()
-func _[T struct{}]() // ERROR "not an interface"
-func _[T interface{ m() T }]()
+func _[T interface{}]() {}
+func _[T C]() {}
+func _[T struct{}]() {}// ERROR "not an interface"
+func _[T interface{ m() T }]() {}
 func _[T1 interface{ m() T2 }, T2 interface{ m() T1 }]() {
-        var _ T1
+	var _ T1
 }
 
 // TODO(gri) expand this
diff --git a/test/typeparam/typelist.go b/test/typeparam/typelist.go
index bd90d86fcf2..5ba14261ab0 100644
--- a/test/typeparam/typelist.go
+++ b/test/typeparam/typelist.go
@@ -10,19 +10,19 @@ package p
 
 // Assignability of an unnamed pointer type to a type parameter that
 // has a matching underlying type.
-func _[T interface{}, PT interface{type *T}] (x T) PT {
-    return &x
+func _[T interface{}, PT interface{ type *T }](x T) PT {
+	return &x
 }
 
 // Indexing of generic types containing type parameters in their type list:
 func at[T interface{ type []E }, E any](x T, i int) E {
-        return x[i]
+	return x[i]
 }
 
 // A generic type inside a function acts like a named type. Its underlying
 // type is itself, its "operational type" is defined by the type list in
 // the tybe bound, if any.
-func _[T interface{type int}](x T) {
+func _[T interface{ type int }](x T) {
 	type myint int
 	var _ int = int(x)
 	var _ T = 42
@@ -30,7 +30,7 @@ func _[T interface{type int}](x T) {
 }
 
 // Indexing a generic type which has a structural contraints to be an array.
-func _[T interface { type [10]int }](x T) {
+func _[T interface{ type [10]int }](x T) {
 	_ = x[9] // ok
 }
 
@@ -44,7 +44,7 @@ func _[T interface{ type *int }](p T) int {
 func _[T interface{ type chan int }](ch T) int {
 	// This would deadlock if executed (but ok for a compile test)
 	ch <- 0
-	return <- ch
+	return <-ch
 }
 
 // Calling of a generic type which has a structural constraint to be a function.
@@ -59,32 +59,34 @@ func _[T interface{ type func(string) int }](f T) int {
 }
 
 // Map access of a generic type which has a structural constraint to be a map.
-func _[V any, T interface { type map[string]V }](p T) V {
+func _[V any, T interface{ type map[string]V }](p T) V {
 	return p["test"]
 }
 
-
 // Testing partial and full type inference, including the case where the types can
 // be inferred without needing the types of the function arguments.
 
+// Cannot embed stand-alone type parameters. Disabled for now.
+/*
 func f0[A any, B interface{type C}, C interface{type D}, D interface{type A}](A, B, C, D)
-func _() {
+func f0x() {
         f := f0[string]
         f("a", "b", "c", "d")
         f0("a", "b", "c", "d")
 }
 
 func f1[A any, B interface{type A}](A, B)
-func _() {
+func f1x() {
         f := f1[int]
         f(int(0), int(0))
         f1(int(0), int(0))
         f(0, 0)
         f1(0, 0)
 }
+*/
 
-func f2[A any, B interface{type []A}](_ A, _ B)
-func _() {
+func f2[A any, B interface{ type []A }](_ A, _ B) {}
+func f2x() {
 	f := f2[byte]
 	f(byte(0), []byte{})
 	f2(byte(0), []byte{})
@@ -92,31 +94,39 @@ func _() {
 	// f2(0, []byte{}) - this one doesn't work
 }
 
+// Cannot embed stand-alone type parameters. Disabled for now.
+/*
 func f3[A any, B interface{type C}, C interface{type *A}](a A, _ B, c C)
-func _() {
+func f3x() {
 	f := f3[int]
 	var x int
 	f(x, &x, &x)
 	f3(x, &x, &x)
 }
+*/
 
-func f4[A any, B interface{type []C}, C interface{type *A}](_ A, _ B, c C)
-func _() {
+func f4[A any, B interface{ type []C }, C interface{ type *A }](_ A, _ B, c C) {}
+func f4x() {
 	f := f4[int]
 	var x int
 	f(x, []*int{}, &x)
 	f4(x, []*int{}, &x)
 }
 
-func f5[A interface{type struct{b B; c C}}, B any, C interface{type *B}](x B) A
-func _() {
+func f5[A interface {
+	type struct {
+		b B
+		c C
+	}
+}, B any, C interface{ type *B }](x B) A { panic(0) }
+func f5x() {
 	x := f5(1.2)
 	var _ float64 = x.b
 	var _ float64 = *x.c
 }
 
-func f6[A any, B interface{type struct{f []A}}](B) A
-func _() {
-	x := f6(struct{f []string}{})
+func f6[A any, B interface{ type struct{ f []A } }](B) A { panic(0) }
+func f6x() {
+	x := f6(struct{ f []string }{})
 	var _ string = x
 }
diff --git a/test/typeparam/typeswitch1.go b/test/typeparam/typeswitch1.go
new file mode 100644
index 00000000000..27161b3db80
--- /dev/null
+++ b/test/typeparam/typeswitch1.go
@@ -0,0 +1,29 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f[T any](i interface{}) {
+	switch i.(type) {
+	case T:
+		println("T")
+	case int:
+		println("int")
+	case int32, int16:
+		println("int32/int16")
+	case struct { a, b T }:
+		println("struct{T,T}")
+	default:
+		println("other")
+	}
+}
+func main() {
+	f[float64](float64(6))
+	f[float64](int(7))
+	f[float64](int32(8))
+	f[float64](struct{a, b float64}{a:1, b:2})
+	f[float64](int8(9))
+}
diff --git a/test/typeparam/typeswitch1.out b/test/typeparam/typeswitch1.out
new file mode 100644
index 00000000000..4bdbccfddb3
--- /dev/null
+++ b/test/typeparam/typeswitch1.out
@@ -0,0 +1,5 @@
+T
+int
+int32/int16
+struct{T,T}
+other
diff --git a/test/typeparam/typeswitch2.go b/test/typeparam/typeswitch2.go
new file mode 100644
index 00000000000..913c56321cc
--- /dev/null
+++ b/test/typeparam/typeswitch2.go
@@ -0,0 +1,31 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "reflect"
+
+func f[T any](i interface{}) {
+	switch x := i.(type) {
+	case T:
+		println("T", x)
+	case int:
+		println("int", x)
+	case int32, int16:
+		println("int32/int16", reflect.ValueOf(x).Int())
+	case struct { a, b T }:
+		println("struct{T,T}", x.a, x.b)
+	default:
+		println("other", reflect.ValueOf(x).Int())
+	}
+}
+func main() {
+	f[float64](float64(6))
+	f[float64](int(7))
+	f[float64](int32(8))
+	f[float64](struct{a, b float64}{a:1, b:2})
+	f[float64](int8(9))
+}
diff --git a/test/typeparam/typeswitch2.out b/test/typeparam/typeswitch2.out
new file mode 100644
index 00000000000..944cc04cc6e
--- /dev/null
+++ b/test/typeparam/typeswitch2.out
@@ -0,0 +1,5 @@
+T +6.000000e+000
+int 7
+int32/int16 8
+struct{T,T} +1.000000e+000 +2.000000e+000
+other 9
diff --git a/test/typeparam/typeswitch3.go b/test/typeparam/typeswitch3.go
new file mode 100644
index 00000000000..6ab03011409
--- /dev/null
+++ b/test/typeparam/typeswitch3.go
@@ -0,0 +1,35 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface { foo() int }
+
+type myint int
+
+func (x myint) foo() int { return int(x) }
+
+type myfloat float64
+func (x myfloat) foo() int { return int(x) }
+
+type myint32 int32
+func (x myint32) foo() int { return int(x) }
+
+func f[T I](i I) {
+	switch x := i.(type) {
+	case T:
+		println("T", x.foo())
+	case myint:
+		println("myint", x.foo())
+	default:
+		println("other", x.foo())
+	}
+}
+func main() {
+	f[myfloat](myint(6))
+	f[myfloat](myfloat(7))
+	f[myfloat](myint32(8))
+}
diff --git a/test/typeparam/typeswitch3.out b/test/typeparam/typeswitch3.out
new file mode 100644
index 00000000000..2c69c72c300
--- /dev/null
+++ b/test/typeparam/typeswitch3.out
@@ -0,0 +1,3 @@
+myint 6
+T 7
+other 8
diff --git a/test/typeparam/typeswitch4.go b/test/typeparam/typeswitch4.go
new file mode 100644
index 00000000000..6113026b658
--- /dev/null
+++ b/test/typeparam/typeswitch4.go
@@ -0,0 +1,33 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface { foo() int }
+
+type myint int
+
+func (x myint) foo() int {return int(x)}
+
+type myfloat float64
+func (x myfloat) foo() int {return int(x)}
+
+type myint32 int32
+func (x myint32) foo() int { return int(x) }
+
+func f[T I](i I) {
+	switch x := i.(type) {
+	case T, myint32:
+		println("T/myint32", x.foo())
+	default:
+		println("other", x.foo())
+	}
+}
+func main() {
+	f[myfloat](myint(6))
+	f[myfloat](myfloat(7))
+	f[myfloat](myint32(8))
+}
diff --git a/test/typeparam/typeswitch4.out b/test/typeparam/typeswitch4.out
new file mode 100644
index 00000000000..b0d54077c92
--- /dev/null
+++ b/test/typeparam/typeswitch4.out
@@ -0,0 +1,3 @@
+other 6
+T/myint32 7
+T/myint32 8
diff --git a/test/typeparam/typeswitch5.go b/test/typeparam/typeswitch5.go
new file mode 100644
index 00000000000..1fc6e0a14ee
--- /dev/null
+++ b/test/typeparam/typeswitch5.go
@@ -0,0 +1,28 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type myint int
+func (x myint) foo() int {return int(x)}
+
+type myfloat float64
+func (x myfloat) foo() float64 {return float64(x) }
+
+func f[T any](i interface{}) {
+	switch x := i.(type) {
+	case interface { foo() T }:
+		println("fooer", x.foo())
+	default:
+		println("other")
+	}
+}
+func main() {
+	f[int](myint(6))
+	f[int](myfloat(7))
+	f[float64](myint(8))
+	f[float64](myfloat(9))
+}
diff --git a/test/typeparam/typeswitch5.out b/test/typeparam/typeswitch5.out
new file mode 100644
index 00000000000..6b4cb4416f4
--- /dev/null
+++ b/test/typeparam/typeswitch5.out
@@ -0,0 +1,4 @@
+fooer 6
+other
+other
+fooer +9.000000e+000
diff --git a/test/typeparam/typeswitch6.go b/test/typeparam/typeswitch6.go
new file mode 100644
index 00000000000..574f4aa819e
--- /dev/null
+++ b/test/typeparam/typeswitch6.go
@@ -0,0 +1,30 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f[T any](i interface{}) {
+	switch i.(type) {
+	case T:
+		println("T")
+	case int:
+		println("int")
+	default:
+		println("other")
+	}
+}
+
+type myint int
+func (myint) foo() {
+}
+
+func main() {
+	f[interface{}](nil)
+	f[interface{}](6)
+	f[interface{foo()}](nil)
+	f[interface{foo()}](7)
+	f[interface{foo()}](myint(8))
+}
diff --git a/test/typeparam/typeswitch6.out b/test/typeparam/typeswitch6.out
new file mode 100644
index 00000000000..441add5ec5b
--- /dev/null
+++ b/test/typeparam/typeswitch6.out
@@ -0,0 +1,5 @@
+other
+T
+other
+int
+T
diff --git a/test/typeparam/typeswitch7.go b/test/typeparam/typeswitch7.go
new file mode 100644
index 00000000000..f2e1279fb41
--- /dev/null
+++ b/test/typeparam/typeswitch7.go
@@ -0,0 +1,37 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f[T any](i interface{foo()}) {
+	switch i.(type) {
+	case interface{bar() T}:
+		println("barT")
+	case myint:
+		println("myint")
+	case myfloat:
+		println("myfloat")
+	default:
+		println("other")
+	}
+}
+
+type myint int
+func (myint) foo() {
+}
+func (x myint) bar() int {
+	return int(x)
+}
+
+type myfloat float64
+func (myfloat) foo() {
+}
+
+func main() {
+	f[int](nil)
+	f[int](myint(6))
+	f[int](myfloat(7))
+}
diff --git a/test/typeparam/typeswitch7.out b/test/typeparam/typeswitch7.out
new file mode 100644
index 00000000000..d7fcad4fee1
--- /dev/null
+++ b/test/typeparam/typeswitch7.out
@@ -0,0 +1,3 @@
+other
+barT
+myfloat
diff --git a/test/typeparam/valimp.dir/a.go b/test/typeparam/valimp.dir/a.go
new file mode 100644
index 00000000000..2ed0063cfd6
--- /dev/null
+++ b/test/typeparam/valimp.dir/a.go
@@ -0,0 +1,32 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Value[T any] struct {
+	val T
+}
+
+// The noinline directive should survive across import, and prevent instantiations
+// of these functions from being inlined.
+
+//go:noinline
+func Get[T any](v *Value[T]) T {
+	return v.val
+}
+
+//go:noinline
+func Set[T any](v *Value[T], val T) {
+	v.val = val
+}
+
+//go:noinline
+func (v *Value[T]) Set(val T) {
+	v.val = val
+}
+
+//go:noinline
+func (v *Value[T]) Get() T {
+	return v.val
+}
diff --git a/test/typeparam/valimp.dir/main.go b/test/typeparam/valimp.dir/main.go
new file mode 100644
index 00000000000..606ff2273af
--- /dev/null
+++ b/test/typeparam/valimp.dir/main.go
@@ -0,0 +1,55 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"a"
+	"fmt"
+)
+
+func main() {
+	var v1 a.Value[int]
+
+	a.Set(&v1, 1)
+	if got, want := a.Get(&v1), 1; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+	v1.Set(2)
+	if got, want := v1.Get(), 2; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+	v1p := new(a.Value[int])
+	a.Set(v1p, 3)
+	if got, want := a.Get(v1p), 3; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+
+	v1p.Set(4)
+	if got, want := v1p.Get(), 4; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+
+	var v2 a.Value[string]
+	a.Set(&v2, "a")
+	if got, want := a.Get(&v2), "a"; got != want {
+		panic(fmt.Sprintf("Get() == %q, want %q", got, want))
+	}
+
+	v2.Set("b")
+	if got, want := a.Get(&v2), "b"; got != want {
+		panic(fmt.Sprintf("Get() == %q, want %q", got, want))
+	}
+
+	v2p := new(a.Value[string])
+	a.Set(v2p, "c")
+	if got, want := a.Get(v2p), "c"; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+
+	v2p.Set("d")
+	if got, want := v2p.Get(), "d"; got != want {
+		panic(fmt.Sprintf("Get() == %d, want %d", got, want))
+	}
+}
diff --git a/test/typeparam/valimp.go b/test/typeparam/valimp.go
new file mode 100644
index 00000000000..76930e5e4f6
--- /dev/null
+++ b/test/typeparam/valimp.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored
diff --git a/test/typeparam/value.go b/test/typeparam/value.go
index 5dd7449d9c7..6c6dabcf7ca 100644
--- a/test/typeparam/value.go
+++ b/test/typeparam/value.go
@@ -12,7 +12,7 @@ type value[T any] struct {
 	val T
 }
 
-func get[T2 any](v *value[T2]) T2 {
+func get[T any](v *value[T]) T {
 	return v.val
 }
 
@@ -20,11 +20,11 @@ func set[T any](v *value[T], val T) {
 	v.val = val
 }
 
-func (v *value[T2]) set(val T2) {
+func (v *value[T]) set(val T) {
 	v.val = val
 }
 
-func (v *value[T2]) get() T2 {
+func (v *value[T]) get() T {
 	return v.val
 }
 
diff --git a/test/uintptrescapes2.go b/test/uintptrescapes2.go
index 3ff1d940425..656286c0ff2 100644
--- a/test/uintptrescapes2.go
+++ b/test/uintptrescapes2.go
@@ -30,7 +30,7 @@ type T struct{}
 func (T) M1(a uintptr) {} // ERROR "escaping uintptr"
 
 //go:uintptrescapes
-func (T) M2(a ...uintptr) {} // ERROR "escaping ...uintptr" "leaking param: a"
+func (T) M2(a ...uintptr) {} // ERROR "escaping ...uintptr"
 
 func TestF1() {
 	var t int                        // ERROR "moved to heap"
diff --git a/test/unsafebuiltins.go b/test/unsafebuiltins.go
index c10f8084a75..4c940aa8559 100644
--- a/test/unsafebuiltins.go
+++ b/test/unsafebuiltins.go
@@ -30,8 +30,11 @@ func main() {
 		assert(len(s) == len(p))
 		assert(cap(s) == len(p))
 
-		// nil pointer
-		mustPanic(func() { _ = unsafe.Slice((*int)(nil), 0) })
+		// nil pointer with zero length returns nil
+		assert(unsafe.Slice((*int)(nil), 0) == nil)
+
+		// nil pointer with positive length panics
+		mustPanic(func() { _ = unsafe.Slice((*int)(nil), 1) })
 
 		// negative length
 		var neg int = -1