Commit graph

187 commits

Author SHA1 Message Date
Matthew Dempsky
35693d037f cmd/compile: fix miscompilation during inlining
When inlining a function call expression, it's possible that the
function callee subexpression has side effects that need to be
preserved. This used to not be an issue, because inlining wouldn't
recognize these as inlinable anyway. But golang.org/cl/266199 extended
the inlining logic to recognize more cases, but did not notice that
the actual inlining code was discarding side effects.

Issue identified by danscales@.

Fixes #42703.

Change-Id: I95f8fc076b6ca4e9362e80ec26dad9d87a5bc44a
Reviewed-on: https://go-review.googlesource.com/c/go/+/271219
Reviewed-by: Dan Scales <danscales@google.com>
Trust: Dan Scales <danscales@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
2020-11-18 22:24:21 +00:00
Dan Scales
4f63e0a1f8 cmd/compile: update comments only for Node types and some functions
Improve the comments in syntax.go on Node structs and constants. Also, updated a
few function header comments.

Change-Id: I3e6e4a3c5678fc0b4e18844507b3460303ce1240
Reviewed-on: https://go-review.googlesource.com/c/go/+/269538
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
2020-11-13 23:26:54 +00:00
Matthew Dempsky
5736eb0013 cmd/compile: support inlining of type switches
This CL adds support for inlining type switches, including exporting
and importing them.

Type switches are represented mostly the same as expression switches.
However, if the type switch guard includes a short variable
declaration, then there are two differences: (1) there's an ONONAME
(in the OTYPESW's Left) to represent the overall pseudo declaration;
and (2) there's an ONAME (in each OCASE's Rlist) to represent the
per-case variables.

For simplicity, this CL simply writes out each variable separately
using iimport/iiexport's normal Vargen mechanism for disambiguating
identically named variables within a function. This could be improved
somewhat, but inlinable type switches are probably too uncommon to
merit the complexity.

While here, remove "case OCASE" from typecheck1. We only type check
"case" clauses as part of a "select" or "switch" statement, never as
standalone statements.

Fixes #37837

Change-Id: I8f42f6c9afdd821d6202af4a6bf1dbcbba0ef424
Reviewed-on: https://go-review.googlesource.com/c/go/+/266203
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
2020-11-06 20:49:11 +00:00
Matthew Dempsky
063a91c0ab cmd/compile: fix recognition of unnamed return variables
In golang.org/cl/266199, I reused the existing code in inlining that
recognizes anonymous variables. However, it turns out that code
mistakenly recognizes anonymous return parameters as named when
inlining a function from the same package.

The issue is funcargs (which is only used for functions parsed from
source) synthesizes ~r names for anonymous return parameters, but
funcargs2 (which is only used for functions imported from export data)
does not.

This CL fixes the behavior so that anonymous return parameters are
handled identically whether a function is inlined within the same
package or across packages. It also adds a proper cross-package test
case demonstrating #33160 is fixed in both cases.

Change-Id: Iaa39a23f5666979a1f5ca6d09fc8c398e55b784c
Reviewed-on: https://go-review.googlesource.com/c/go/+/266719
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
2020-11-01 01:06:56 +00:00
Matthew Dempsky
7191f1136b cmd/compile: fix reassignVisitor
reassignVisitor was short-circuiting on assignment statements after
checking the LHS, but there might be further assignment statements
nested within the RHS expressions.

Fixes #42284.

Change-Id: I175eef87513b973ed5ebe6a6527adb9766dde6cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/266618
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-30 19:30:44 +00:00
Matthew Dempsky
e62adb1c0b cmd/compile: fix devirtualization of promoted interface methods
A method selector expression can pick out a method or promoted method
(represented by ODOTMETH), but it can also pick out an interface
method from an embedded interface-typed field (represented by
ODOTINTER).

In the case that we're picking out an interface method, we're not able
to fully devirtualize the method call. However, we're still able to
improve escape analysis somewhat. E.g., the included test case
demonstrates that we can optimize "i.M()" to "i.(T).I.M()", which
means the T literal can be stack allocated instead of heap allocated.

Fixes #42279.

Change-Id: Ifa21d19011e2f008d84f9624b7055b4676b6d188
Reviewed-on: https://go-review.googlesource.com/c/go/+/266300
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2020-10-30 00:47:37 +00:00
Matthew Dempsky
aa4f48b751 cmd/compile: gracefully fail when devirtualization fails
We should still be able to devirtualize here, but I need to understand
the AST better. While I'm doing that, at least switch to a graceful
failure case (i.e., skip the optimization and print a warning message)
to fix the x/text builders.

Updates #42279.

Change-Id: Ie2b0b701fccf590d0cabfead703fc2fa999072cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/266359
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-29 20:19:24 +00:00
Matthew Dempsky
5cc43c51c9 cmd/compile: early devirtualization of interface method calls
After inlining, add a pass that looks for interface calls where we can
statically determine the interface value's concrete type. If such a
case is found, insert an explicit type assertion to the concrete type
so that escape analysis can see it.

Fixes #33160.

Change-Id: I36932c691693f0069e34384086d63133e249b06b
Reviewed-on: https://go-review.googlesource.com/c/go/+/264837
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2020-10-29 19:06:32 +00:00
Matthew Dempsky
f2c0c2b902 cmd/compile: improve inlining and static analysis
When inlining a function call "f()", if "f" contains exactly 1
"return" statement and doesn't name its result parameters, it's
inlined to declare+initialize the result value using the AST
representation that's compatible with staticValue.

Also, extend staticValue to skip over OCONVNOP nodes (often introduced
by inlining), and fix various bits of code related to handling method
expressions.

Updates #33160.

Change-Id: If8652e319f0a5700cf9d40a7a62e369a2a359229
Reviewed-on: https://go-review.googlesource.com/c/go/+/266199
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2020-10-29 19:03:09 +00:00
Branden J Brown
4fb4291388 cmd/compile: inline functions evaluated in go and defer statements
The inlining pass previously bailed upon encountering a go or defer statement, so it would not inline functions e.g. used to provide arguments to the deferred function. This change preserves the behavior of not inlining the
deferred function itself, but it allows the inlining walk to proceed into its arguments.

Fixes #42194

Change-Id: I4e82029d8dcbe69019cc83ae63a4b29af45ec777
Reviewed-on: https://go-review.googlesource.com/c/go/+/264997
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-10-29 16:47:10 +00:00
Alberto Donizetti
3bac5faa4a cmd/compile: make gc debug flags collector a struct
gc debug flags are currently stored in a 256-long array, that is then
addressed using the ASCII numeric value of the flag itself (a quirk
inherited from the old C compiler). It is also a little wasteful,
since we only define 16 flags, and the other 240 array elements are
always empty.

This change makes Debug a struct, which also provides static checking
that we're not referencing flags that does not exist.

Change-Id: I2f0dfef2529325514b3398cf78635543cdf48fe0
Reviewed-on: https://go-review.googlesource.com/c/go/+/263539
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-10-22 09:33:46 +00:00
Dan Scales
8fe372c7b3 cmd/compile: allowing inlining of functions with OCALLPART
OCALLPART is exported in its original form, which is as an OXDOT.

The body of the method value wrapper created in makepartialcall() was
not being typechecked, and that was causing a problem during escape
analysis, so I added code to typecheck the body.

The go executable got slightly bigger with this change (13598111 ->
13598905), because of extra exported methods with OCALLPART (I
believe), while the text size got slightly smaller (9686964 ->
9686643).

This is mainly part of the work to make sure all function bodies can
be exported (for purposes of generics), but might as well fix the
OCALLPART inlining bug as well.

Fixes #18493

Change-Id: If7aa055ff78ed7a6330c6a1e22f836ec567d04fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/263620
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-10-20 00:07:42 +00:00
Matthew Dempsky
1bcf6beec5 cmd/compile: use staticValue for inlining logic
This CL replaces the ad hoc and duplicated logic for detecting
inlinable calls with a single "inlCallee" function, which uses the
"staticValue" helper function introduced in an earlier commit.

Updates #41474.

Change-Id: I103d4091b10366fce1344ef2501222b7df68f21d
Reviewed-on: https://go-review.googlesource.com/c/go/+/256460
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Trust: Matthew Dempsky <mdempsky@google.com>
2020-10-15 18:35:44 +00:00
Matthew Dempsky
497ea0610e cmd/compile: allow inlining of "for" loops
We already allow inlining "if" and "goto" statements, so we might as
well allow "for" loops too. The majority of frontend support is
already there too.

The critical missing feature at the moment is that inlining doesn't
properly reassociate OLABEL nodes with their control statement (e.g.,
OFOR) after inlining. This eventually causes SSA construction to fail.

As a workaround, this CL only enables inlining for unlabeled "for"
loops. It's left to a (yet unplanned) future CL to add support for
labeled "for" loops.

The increased opportunity for inlining leads to a small growth in
binary size. For example:

$ size go.old go.new
   text	   data	    bss	    dec	    hex	filename
9740163	 320064	 230656	10290883	 9d06c3	go.old
9793399	 320064	 230656	10344119	 9dd6b7	go.new

Updates #14768.
Fixes #41474.

Change-Id: I827db0b2b9d9fa2934db05caf6baa463f0cd032a
Reviewed-on: https://go-review.googlesource.com/c/go/+/256459
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-10-15 18:26:33 +00:00
Matthew Dempsky
c0417df156 cmd/compile: improve escape analysis of known calls
Escape analysis is currently very naive about identifying calls to
known functions: it only recognizes direct calls to a declared
function, or direct calls to a closure.

This CL adds a new "staticValue" helper function that can trace back
through local variables that were initialized and never reassigned
based on a similar optimization already used by inlining. (And to be
used by inlining in a followup CL.)

Updates #41474.

Change-Id: I8204fd3b1e150ab77a27f583985cf099a8572b2e
Reviewed-on: https://go-review.googlesource.com/c/go/+/256458
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
2020-10-15 18:26:06 +00:00
Matthew Dempsky
cced777026 cmd/compile: set n.Name.Defn for inlined parameters
Normally, when variables are declared and initialized using ":=", we
set the variable's n.Name.Defn to point to the initialization
assignment node (i.e., OAS or OAS2). Further, some frontend
optimizations look for variables that are initialized but never
reassigned.

However, when inl.go inlines calls, it was declaring the inlined
variables, and then separately assigning to them. This CL changes
inl.go tweaks the AST to fit the combined declaration+initialization
pattern.

This isn't terribly useful by itself, but it allows further followup
optimizations.

Updates #41474.

Change-Id: I62a9752c60414305679e0ed15a6563baa0224efa
Reviewed-on: https://go-review.googlesource.com/c/go/+/256457
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-10-15 18:25:47 +00:00
Cuong Manh Le
62ccee49d6 cmd/compile: refactor detecting package reflect logic
Passes toolstash-check.

Change-Id: Ie4b1f61528bb183dc66bb6955851a47b2641549c
Reviewed-on: https://go-review.googlesource.com/c/go/+/228859
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-20 02:39:16 +00:00
David Chase
fced302aa1 cmd/compile: change gc logging to report inline failure instead of success
I've been experimenting with this, success is the wrong thing to report
even though it seems to log much less.

Change-Id: I7c25a45d2f41e82b6c8dd8b0a56ba848c63fb21a
Reviewed-on: https://go-review.googlesource.com/c/go/+/223298
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-10 20:34:40 +00:00
Dan Scales
ed7a8332c4 cmd/compile: allow mid-stack inlining when there is a cycle of recursion
We still disallow inlining for an immediately-recursive function, but allow
inlining if a function is in a recursion chain.

If all functions in the recursion chain are simple, then we could inline
forever down the recursion chain (eventually running out of stack on the
compiler), so we add a map to keep track of the functions we have
already inlined at a call site. We stop inlining when we reach a
function that we have already inlined in the recursive chain. Of course,
normally the inlining will have stopped earlier, because of the cost
function.

We could also limit the depth of inlining by a simple count (say, limit
max inlining of 10 at any given site). Would that limit other
opportunities too much?

Added a test in test/inline.go. runtime.BenchmarkStackCopyNoCache() is
also already a good test that triggers the check to stop inlining
when we reach the start of the recursive chain again.

For the bent benchmark suite, the performance improvement was mostly not
statistically significant, but the geomean averaged out to: -0.68%. The text size
increase was less than .1% for all bent benchmarks. The cmd/go text size increase
was 0.02% and the cmd/compile text size increase was .1%.

Fixes #29737

Change-Id: I892fa84bb07a947b3125ec8f25ed0e508bf2bdf5
Reviewed-on: https://go-review.googlesource.com/c/go/+/226818
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-03 21:43:52 +00:00
Cuong Manh Le
e9850462aa cmd/compile: don't inline reflect.Value.UnsafeAddr/Pointer if enable checkptr
Fixes #35073

Change-Id: I4b555bbc33d39a97544e6dd9c61d95ae212f472b
Reviewed-on: https://go-review.googlesource.com/c/go/+/222878
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-01 06:12:05 +00:00
Josh Bleecher Snyder
956f64888d cmd/compile: make inlining intrinsics cost one
We were assigning a cost of 2 for intrinsics:
One when we recognized an intrinsic,
and one for the OCALLFUNC node.

I believe that the intent was that intrinsics should
cost 1, since they are typically an arithmetic op,
and because they tend to occur in performance-sensitive code.
(Not that any of this is particularly principled right now.)

Stop charging when we recognize an intrinsic;
let the OCALLFUNC node cover the cost.

This has a negligible impact on std+cmd.

Change-Id: Ie6ae5c18da3ae7e40aec425aed95c6999c2831a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/221357
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-02-27 20:01:59 +00:00
TennyZhuang
ee46f135a9 cmd/compile: output cost while inlining function with Debug['m'] > 1
The existing implementation outputs inline cost iff function cannot be inlined with Debug['m'] > 1, the cost info is also useful if the function is inlineable.

Fixes #36780

Change-Id: Ic96f6baf96aee25fb4b33d31d4d644dc2310e536
Reviewed-on: https://go-review.googlesource.com/c/go/+/216778
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-02-26 14:44:24 +00:00
David Chase
4d0ed149ff cmd/compile: enable optimizer logging for inline-related events
Change-Id: I72de8cb5e1df7a73e46a4b7e5b4e7290fcca4bc1
Reviewed-on: https://go-review.googlesource.com/c/go/+/204162
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-11-12 19:48:38 +00:00
Matthew Dempsky
80a6fedea0 cmd/compile: add -d=checkptr to validate unsafe.Pointer rules
This CL adds -d=checkptr as a compile-time option for adding
instrumentation to check that Go code is following unsafe.Pointer
safety rules dynamically. In particular, it currently checks two
things:

1. When converting unsafe.Pointer to *T, make sure the resulting
pointer is aligned appropriately for T.

2. When performing pointer arithmetic, if the result points to a Go
heap object, make sure we can find an unsafe.Pointer-typed operand
that pointed into the same object.

These checks are currently disabled for the runtime, and can also be
disabled through a new //go:nocheckptr annotation. The latter is
necessary for functions like strings.noescape, which intentionally
violate safety rules to workaround escape analysis limitations.

Fixes #22218.

Change-Id: If5a51273881d93048f74bcff10a3275c9c91da6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/162237
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-10-17 00:40:21 +00:00
Matthew Dempsky
06b12e660c cmd/compile: move some ONAME-specific flags from Node to Name
The IsClosureVar, IsOutputParamHeapAddr, Assigned, Addrtaken,
InlFormal, and InlLocal flags are only interesting for ONAME nodes, so
it's better to set these flags on Name.flags instead of Node.flags.

Two caveats though:

1. Previously, we would set Assigned and Addrtaken on the entire
expression tree involved in an assignment or addressing operation.
However, the rest of the compiler only actually cares about knowing
whether the underlying ONAME (if any) was assigned/addressed.

2. This actually requires bumping Name.flags from bitset8 to bitset16,
whereas it doesn't allow shrinking Node.flags any. However, Name has
some trailing padding bytes, so expanding Name.flags doesn't cost any
memory.

Passes toolstash-check.

Change-Id: I7775d713566a38d5b9723360b1659b79391744c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/200898
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-14 18:57:11 +00:00
Mohit Verma
c729116332 cmd/compile: use Node.Right for OAS2* nodes (cleanup)
This CL changes cmd/compile to use Node.Right instead of
Node.Rlist for OAS2FUNC/OAS2RECV/OAS2MAPR/OAS2DOTTYPE nodes.
Fixes #32293

Change-Id: I4c9d9100be2d98d15e016797f934f64d385f5faa
Reviewed-on: https://go-review.googlesource.com/c/go/+/197817
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-09-28 05:04:49 +00:00
Keith Randall
6c842cc610 cmd/compile: mention issue 28603 when discussing where inline marks go
Update #28603

Change-Id: I8bdbea57b3661e15dcc760d27252b794daa476db
Reviewed-on: https://go-review.googlesource.com/c/go/+/177697
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2019-05-17 03:46:38 +00:00
LE Manh Cuong
19f5c233d1 cmd/compile: remove outdate TODO in inl.go
Mid-stack inlining is enable now, see #19348, but we still can not
remove the special case for runtime.heapBits.nextArena, because
runtime.heapBits.next is too complex to be inlined
(cost 96 exceeds budget 80).

Change-Id: I04ea86509074afdc83a3f70d68b8a1a8829763d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/174839
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-02 14:44:05 +00:00
Keith Randall
fd788a86b6 cmd/compile: always mark atColumn1 results as statements
In 31618, we end up comparing the is-stmt-ness of positions
to repurpose real instructions as inline marks. If the is-stmt-ness
doesn't match, we end up not being able to remove the inline mark.

Always use statement-full positions to do the matching, so we
always find a match if there is one.

Also always use positions that are statements for inline marks.

Fixes #31618

Change-Id: Idaf39bdb32fa45238d5cd52973cadf4504f947d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/173324
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-04-23 17:39:11 +00:00
David Chase
376ce8c880 cmd/compile: shortcut intrinsic inlining AFTER getcallerXX check
A check in inl.go to prevent inlining of functions calling
either getcallerpc or getcallersp does not work when these
functions are intrinsics. Swap checks to fix.

Includes test.

No bug, this was discovered in the course of a ridiculous
experiment with inlining.

Change-Id: Ie1392523bb89882d586678f2674e1a4eadc5e431
Reviewed-on: https://go-review.googlesource.com/c/go/+/172217
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-19 20:18:29 +00:00
Keith Randall
c46ebec322 cmd/compile: get rid of unnecessary inline marks
If no other instruction mentions an inline mark, we can get rid of it.
This normally happens when the inlined function is empty, or when all
of its code is folded into other instructions.

Also use consistent statement-ness for inline mark positions, so that
more of them can be removed in favor of existing instructions.

Update #29571
Fixes #31172

Change-Id: I71f84d355101f37a27960d9e8528f42f92767496
Reviewed-on: https://go-review.googlesource.com/c/go/+/170445
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-04-08 16:46:20 +00:00
Matthew Dempsky
c0cfe9687f cmd/compile: rewrite f(g()) for multi-value g() during typecheck
This is a re-attempt at CL 153841, which caused two regressions:

1. crypto/ecdsa failed to build with -gcflags=-l=4. This was because
when "t1, t2, ... := g(); f(t1, t2, ...)" was exported, we were losing
the first assignment from the call's Ninit field.

2. net/http/pprof failed to run with -gcflags=-N. This is due to a
conflict with CL 159717: as of that CL, package-scope initialization
statements are executed within the "init.ializer" function, rather
than the "init" function, and the generated temp variables need to be
moved accordingly too.

[Rest of description is as before.]

This CL moves order.go's copyRet logic for rewriting f(g()) into t1,
t2, ... := g(); f(t1, t2, ...) earlier into typecheck. This allows the
rest of the compiler to stop worrying about multi-value functions
appearing outside of OAS2FUNC nodes.

This changes compiler behavior in a few observable ways:

1. Typechecking error messages for builtin functions now use general
case error messages rather than unnecessarily differing ones.

2. Because f(g()) is rewritten before inlining, saved inline bodies
now see the rewritten form too. This could be addressed, but doesn't
seem worthwhile.

3. Most notably, this simplifies escape analysis and fixes a memory
corruption issue in esc.go. See #29197 for details.

Fixes #15992.
Fixes #29197.

Change-Id: I930b10f7e27af68a0944d6c9bfc8707c3fab27a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/166983
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-03-14 21:00:20 +00:00
Matthew Dempsky
38642b9fce Revert "cmd/compile: rewrite f(g()) for multi-value g() during typecheck"
This reverts commit d96b7fbf98.

Reason for revert: broke noopt and longtest builders.

Change-Id: Ifaec64d817c4336cb255a2e9db00526b7bc5606a
Reviewed-on: https://go-review.googlesource.com/c/164757
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-01 05:58:51 +00:00
Matthew Dempsky
d96b7fbf98 cmd/compile: rewrite f(g()) for multi-value g() during typecheck
This CL moves order.go's copyRet logic for rewriting f(g()) into t1,
t2, ... = g(); f(t1, t2, ...) earlier into typecheck. This allows the
rest of the compiler to stop worrying about multi-value functions
appearing outside of OAS2FUNC nodes.

This changes compiler behavior in a few observable ways:

1. Typechecking error messages for builtin functions now use general
case error messages rather than unnecessarily differing ones.

2. Because f(g()) is rewritten before inlining, saved inline bodies
now see the rewritten form too. This could be addressed, but doesn't
seem worthwhile.

3. Most notably, this simplifies escape analysis and fixes a memory
corruption issue in esc.go. See #29197 for details.

Fixes #15992.
Fixes #29197.

Change-Id: I86a70668301efeec8fbd11fe2d242e359a3ad0af
Reviewed-on: https://go-review.googlesource.com/c/153841
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-02-28 22:50:08 +00:00
Keith Randall
69c2c56453 cmd/compile,runtime: redo mid-stack inlining tracebacks
Work involved in getting a stack trace is divided between
runtime.Callers and runtime.CallersFrames.

Before this CL, runtime.Callers returns a pc per runtime frame.
runtime.CallersFrames is responsible for expanding a runtime frame
into potentially multiple user frames.

After this CL, runtime.Callers returns a pc per user frame.
runtime.CallersFrames just maps those to user frame info.

Entries in the result of runtime.Callers are now pcs
of the calls (or of the inline marks), not of the instruction
just after the call.

Fixes #29007
Fixes #28640
Update #26320

Change-Id: I1c9567596ff73dc73271311005097a9188c3406f
Reviewed-on: https://go-review.googlesource.com/c/152537
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-12-28 20:55:36 +00:00
David Chase
624e197c71 cmd/compile: decrease inlining call cost from 60 to 57
A Go user made a well-documented request for a slightly
lower threshold.  I tested against a selection of other
people's benchmarks, and saw a tiny benefit (possibly noise)
at equally tiny cost, and no unpleasant surprises observed
in benchmarking.

I.e., might help, doesn't hurt, low risk, request was
delivered on a silver platter.

It did, however, change the behavior of one test because
now bytes.Buffer.Grow is eligible for inlining.

Updates #19348.

Change-Id: I85e3088a4911290872b8c6bda9601b5354c48695
Reviewed-on: https://go-review.googlesource.com/c/151977
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-12-01 15:03:28 +00:00
Josh Bleecher Snyder
bc43889566 cmd/compile: bulk rename
This change does a bulk rename of several identifiers in the compiler.
See #27167 and https://docs.google.com/document/d/19_ExiylD9MRfeAjKIfEsMU1_RGhuxB9sA0b5Zv7byVI/
for context and for discussion of these particular renames.

Commands run to generate this change:

gorename -from '"cmd/compile/internal/gc".OPROC' -to OGO
gorename -from '"cmd/compile/internal/gc".OCOM' -to OBITNOT
gorename -from '"cmd/compile/internal/gc".OMINUS' -to ONEG
gorename -from '"cmd/compile/internal/gc".OIND' -to ODEREF
gorename -from '"cmd/compile/internal/gc".OARRAYBYTESTR' -to OBYTES2STR
gorename -from '"cmd/compile/internal/gc".OARRAYBYTESTRTMP' -to OBYTES2STRTMP
gorename -from '"cmd/compile/internal/gc".OARRAYRUNESTR' -to ORUNES2STR
gorename -from '"cmd/compile/internal/gc".OSTRARRAYBYTE' -to OSTR2BYTES
gorename -from '"cmd/compile/internal/gc".OSTRARRAYBYTETMP' -to OSTR2BYTESTMP
gorename -from '"cmd/compile/internal/gc".OSTRARRAYRUNE' -to OSTR2RUNES

gorename -from '"cmd/compile/internal/gc".Etop' -to ctxStmt
gorename -from '"cmd/compile/internal/gc".Erv' -to ctxExpr
gorename -from '"cmd/compile/internal/gc".Ecall' -to ctxCallee
gorename -from '"cmd/compile/internal/gc".Efnstruct' -to ctxMultiOK
gorename -from '"cmd/compile/internal/gc".Easgn' -to ctxAssign
gorename -from '"cmd/compile/internal/gc".Ecomplit' -to ctxCompLit

Not altered: parameters and local variables (mostly in typecheck.go) named top,
which should probably now be called ctx (and which should probably have a named type).
Also not altered: Field called Top in gc.Func.

gorename -from '"cmd/compile/internal/gc".Node.Isddd' -to IsDDD
gorename -from '"cmd/compile/internal/gc".Node.SetIsddd' -to SetIsDDD
gorename -from '"cmd/compile/internal/gc".nodeIsddd' -to nodeIsDDD
gorename -from '"cmd/compile/internal/types".Field.Isddd' -to IsDDD
gorename -from '"cmd/compile/internal/types".Field.SetIsddd' -to SetIsDDD
gorename -from '"cmd/compile/internal/types".fieldIsddd' -to fieldIsDDD

Not altered: function gc.hasddd, params and local variables called isddd
Also not altered: fmt.go prints nodes using "isddd(%v)".

cd cmd/compile/internal/gc; go generate

I then manually found impacted comments using exact string match
and fixed them up by hand. The comment changes were trivial.

Passes toolstash-check.

Fixes #27167. If this experiment is deemed a success,
we will open a new tracking issue for renames to do
at the end of the 1.13 cycles.

Change-Id: I2dc541533d2ab0d06cb3d31d65df205ecfb151e8
Reviewed-on: https://go-review.googlesource.com/c/150140
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-11-19 00:02:53 +00:00
Keith Randall
13baf4b2cd cmd/compile: encourage inlining of functions with single-call bodies
This is a simple tweak to allow a bit more mid-stack inlining.
In cases like this:

func f() {
    g()
}

We'd really like to inline f into its callers. It can't hurt.

We implement this optimization by making calls a bit cheaper, enough
to afford a single call in the function body, but not 2.
The remaining budget allows for some argument modification, or perhaps
a wrapping conditional:

func f(x int) {
    g(x, 0)
}
func f(x int) {
    if x > 0 {
        g()
    }
}

Update #19348

Change-Id: Ifb1ea0dd1db216c3fd5c453c31c3355561fe406f
Reviewed-on: https://go-review.googlesource.com/c/147361
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
2018-11-08 17:29:23 +00:00
Matthew Dempsky
2dda040f19 cmd/compile/internal/gc: represent labels as bare Syms
Avoids allocating an ONAME for OLABEL, OGOTO, and named OBREAK and
OCONTINUE nodes.

Passes toolstash-check.

Change-Id: I359142cd48e8987b5bf29ac100752f8c497261c1
Reviewed-on: https://go-review.googlesource.com/c/145200
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-10-27 07:32:06 +00:00
Matthew Dempsky
5185744962 cmd/compile: remove obsolete "safe" mode
Nowadays there are better ways to safely run untrusted Go programs, like
NaCl and gVisor.

Change-Id: I20c45f13a50dbcf35c343438b720eb93e7b4e13a
Reviewed-on: https://go-review.googlesource.com/c/142717
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2018-10-17 19:00:37 +00:00
Josh Bleecher Snyder
555d8c455a cmd/compile: remove some inl budget hacks
Prior to stack tracing, inlining could cause
dead pointers to be kept alive in some loops.
See #18336 and CL 31674.

The adjustment removed by this change preserved the inlining status quo
in the face of Node structure changes, to avoid creating new problems.
Now that stack tracing provides precision, these hacks can be removed.

Of course, our inlining code model is already hacky (#17566),
but at least now there will be fewer epicyclical hacks.

Newly inline-able functions in std cmd as a result of this change:

hash/adler32/adler32.go:65:6: can inline (*digest).UnmarshalBinary
hash/fnv/fnv.go:281:6: can inline (*sum32).UnmarshalBinary
hash/fnv/fnv.go:292:6: can inline (*sum32a).UnmarshalBinary
reflect/value.go:1298:6: can inline Value.OverflowComplex
compress/bzip2/bit_reader.go:25:6: can inline newBitReader
encoding/xml/xml.go:365:6: can inline (*Decoder).switchToReader
vendor/golang_org/x/crypto/cryptobyte/builder.go:77:6: can inline (*Builder).AddUint16
crypto/x509/x509.go:1851:58: can inline buildExtensions.func2.1.1
crypto/x509/x509.go:1871:58: can inline buildExtensions.func2.3.1
crypto/x509/x509.go:1883:58: can inline buildExtensions.func2.4.1
cmd/vet/internal/cfg/builder.go:463:6: can inline (*builder).labeledBlock
crypto/tls/handshake_messages.go:1450:6: can inline (*newSessionTicketMsg).marshal
crypto/tls/handshake_server.go:769:6: can inline (*serverHandshakeState).clientHelloInfo
crypto/tls/handshake_messages.go:1171:6: can inline (*nextProtoMsg).unmarshal
cmd/link/internal/amd64/obj.go:40:6: can inline Init
cmd/link/internal/ppc64/obj.go:40:6: can inline Init
net/http/httputil/persist.go:54:6: can inline NewServerConn
net/http/fcgi/child.go:83:6: can inline newResponse
cmd/compile/internal/ssa/poset.go:245:6: can inline (*poset).newnode

Change-Id: I19e8e383a6273849673d35189a9358870665f82f
Reviewed-on: https://go-review.googlesource.com/c/141117
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-10-10 19:29:34 +00:00
Matthew Dempsky
d546bebe34 cmd/compile/internal/gc: disable binary package export format
The new indexed package export format appears stable, and no reports
of needing to revert back to binary package export.

This CL disables the binary package export format by mechanically
replacing 'flagiexport' with 'true', and then superficial code
cleanups to keep the resulting code idiomatic. The resulting dead code
is removed in a followup CL.

Change-Id: Ic30d85f78778a31d279a56b9ab14e80836d50135
Reviewed-on: https://go-review.googlesource.com/c/139337
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-10-03 19:24:11 +00:00
Yury Smolsky
9e2a04d5eb cmd/compile: add sources for inlined functions to ssa.html
This CL adds the source code of all inlined functions
into the function specified in $GOSSAFUNC.
The code is appended to the sources column of ssa.html.

ssaDumpInlined is populated with references to inlined functions.
Then it is used for dumping the sources in buildssa.

The source columns contains code in following order:
target function, inlined functions sorted by filename, lineno.

Fixes #25904

Change-Id: I4f6d4834376f1efdfda1f968a5335c0543ed36bc
Reviewed-on: https://go-review.googlesource.com/126606
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-08-23 05:11:33 +00:00
Keith Randall
5fc70b6fac cmd/compile: set stricter inlining threshold in large functions
If we're compiling a large function, be more picky about how big
the function we're inlining is.  If the function is >5000 nodes,
we lower the inlining threshold from a cost of 80 to 20.

Turns out reflect.Value's cost is exactly 80.  That's the function
at issue in #26546.

20 was chosen as a proxy for "inlined body is smaller than the call would be".
Simple functions still get inlined, like this one at cost 7:

func ifaceIndir(t *rtype) bool {
	return t.kind&kindDirectIface == 0
}

5000 nodes was chosen as the big function size.  Here are all the
5000+ node (~~1000+ lines) functions in the stdlib:

5187 cmd/internal/obj/arm (*ctxt5).asmout
6879 cmd/internal/obj/s390x (*ctxtz).asmout
6567 cmd/internal/obj/ppc64 (*ctxt9).asmout
9643 cmd/internal/obj/arm64 (*ctxt7).asmout
5042 cmd/internal/obj/x86 (*AsmBuf).doasm
8768 cmd/compile/internal/ssa rewriteBlockAMD64
8878 cmd/compile/internal/ssa rewriteBlockARM
8344 cmd/compile/internal/ssa rewriteValueARM64_OpARM64OR_20
7916 cmd/compile/internal/ssa rewriteValueARM64_OpARM64OR_30
5427 cmd/compile/internal/ssa rewriteBlockARM64
5126 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_50
6152 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_60
6412 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_70
6486 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_80
6534 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_90
6534 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_100
6534 cmd/compile/internal/ssa rewriteValuePPC64_OpPPC64OR_110
6675 cmd/compile/internal/gc typecheck1
5433 cmd/compile/internal/gc walkexpr
14070 cmd/vendor/golang.org/x/arch/arm64/arm64asm decodeArg

There are a lot more smaller (~1000 node) functions in the stdlib.
The function in #26546 has 12477 nodes.

At some point it might be nice to have a better heuristic for "inlined
body is smaller than the call", a non-cliff way to scale down the cost
as the function gets bigger, doing cheaper inlined calls first, etc.
All that can wait for another release. I'd like to do this CL for
1.11.

Fixes #26546
Update #17566

Change-Id: Idda13020e46ec2b28d79a17217f44b189f8139ac
Reviewed-on: https://go-review.googlesource.com/125516
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-07-24 16:11:08 +00:00
David Chase
c6e455bb11 cmd/compile: conditional on -race, disable inline of go:norace
Adds the appropriate check to inl.go.
Includes tests of both -race+go:norace and plain go:norace.

Fixes #24651.

Change-Id: Id806342430c20baf4679a985d12eea3b677092e0
Reviewed-on: https://go-review.googlesource.com/119195
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-06-19 20:59:10 +00:00
David Chase
c08b01ecb4 cmd/compile: fix panic-okay-to-inline change; adjust tests
This line of the inlining tuning experiment
https://go-review.googlesource.com/c/go/+/109918/1/src/cmd/compile/internal/gc/inl.go#347
was incorrectly rewritten in a later patch to use the call
cost, not the panic cost, and thus the inlining of panic
didn't occur when it should.  I discovered this when I
realized that tests should have failed, but didn't.

Fix is to make the correct change, and also to modify the
tests that this causes to fail.  One test now asserts the
new normal, the other calls "ppanic" instead which is
designed to behave like panic but not be inlined.

Change-Id: I423bb7f08bd66a70d999826dd9b87027abf34cdf
Reviewed-on: https://go-review.googlesource.com/116656
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-06-06 20:35:23 +00:00
Than McIntosh
1ba26a33ce cmd/compile: fix DWARF inline debug issue with dead local vars
Fix a problem in DWARF inline debug generation relating to handling of
statically unreachable local variables. For a function such as:

    const always = true

    func HasDeadLocal() int {
      if always {
        return 9
      }
      x := new(Something)
      ...
      return x.y
    }

the variable "x" is placed onto the Dcl list for the function during
parsing, but the actual declaration node is deleted later on when
gc.Main invokes "deadcode". Later in the compile the DWARF code emits
an abstract function with "x" (since "x" was on the Dcl list at the
point of the inline), but the export data emitted does not contain
"x". This then creates clashing/inconsistant DWARF abstract function
DIEs later on if HasDeadLocal is inlined in somewhere else.

As a fix, the inliner now pruned away variables such as "x" when
creating a copy of the Dcl list as part of the inlining; this means
that both the export data generator and the DWARF emitter wind up
seeing a consistent picture.

Fixes #25459

Change-Id: I753dc4e9f9ec694340adba5f43c907ba8cc9badc
Reviewed-on: https://go-review.googlesource.com/114090
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-05-25 19:37:35 +00:00
David Chase
87a18c6109 cmd/compile: refactor inlining parameters; inline panic
Inlining was refactored to perform tuning experiments,
with the "knobs" now set to also inline functions/methods
that include panic(), and -l=4 (inline calls) now expressed
as a change to costs, rather than scattered if-thens.

The -l=4 inline-calls penalty is chosen to be the best
found during experiments; it makes some programs much
larger and slower (notably, the compiler itself) and is
believed to be risky for machine-generated code in general,
which is why it is not the default.  It is also not
well-tested with the debugger and DWARF output.

This change includes an explicit go:noinline applied to the
method that is the largest cause of compiler binary growth
and slowdown for midstack inlining; there are others,
ideally whatever heuristic eventually appears will make
this unnecessary.

Change-Id: Idf7056ed2f961472cf49d2fd154ee98bef9421e2
Reviewed-on: https://go-review.googlesource.com/109918
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-05-22 02:58:04 +00:00
Matthew Dempsky
ca2f85fd3f cmd/compile: add indexed export format
This CL introduces a new indexed data format for package export
data. This improves on the previous (sequential) binary format by
allowing the compiler to selectively (and lazily) load only the data
that's actually needed for compilation.

In large Go projects, the package export data can become very large
due to transitive type declaration dependencies and inline
function/method bodies. By lazily loading these declarations and
bodies as needed, we avoid wasting time and memory processing
unnecessary and/or redundant data.

In the benchmarks below, "old" is -iexport=false and "new" is
-iexport=true. The suffixes indicate the compiler concurrency (-c) and
inlining (-l) settings used for the build (using -gcflags=all=-foo).
Benchmarks were run on an HP Z620.

Juju is "go build -a github.com/juju/juju/cmd/...":

name          old real-time/op  new real-time/op  delta
Juju/c=1/l=0        44.0s ± 1%        38.7s ± 9%  -11.97%  (p=0.001 n=7+7)
Juju/c=1/l=4        53.7s ± 3%        45.3s ± 4%  -15.53%  (p=0.001 n=7+7)
Juju/c=4/l=0        39.7s ± 8%        32.0s ± 4%  -19.38%  (p=0.001 n=7+7)
Juju/c=4/l=4        46.3s ± 4%        38.0s ± 4%  -18.06%  (p=0.001 n=7+7)

name          old user-time/op  new user-time/op  delta
Juju/c=1/l=0         371s ± 1%         300s ± 0%  -19.07%  (p=0.001 n=7+6)
Juju/c=1/l=4         482s ± 0%         374s ± 1%  -22.37%  (p=0.001 n=7+7)
Juju/c=4/l=0         410s ± 1%         340s ± 1%  -17.19%  (p=0.001 n=7+7)
Juju/c=4/l=4         532s ± 1%         424s ± 1%  -20.26%  (p=0.001 n=7+7)

name          old sys-time/op   new sys-time/op   delta
Juju/c=1/l=0        33.4s ± 1%        28.4s ± 2%  -15.02%  (p=0.001 n=7+7)
Juju/c=1/l=4        40.7s ± 2%        32.8s ± 3%  -19.51%  (p=0.001 n=7+7)
Juju/c=4/l=0        39.8s ± 2%        34.4s ± 2%  -13.74%  (p=0.001 n=7+7)
Juju/c=4/l=4        48.4s ± 2%        40.4s ± 2%  -16.50%  (p=0.001 n=7+7)

Kubelet is "go build -a k8s.io/kubernetes/cmd/kubelet":

name             old real-time/op  new real-time/op  delta
Kubelet/c=1/l=0        42.0s ± 1%        34.8s ± 1%  -17.27%  (p=0.008 n=5+5)
Kubelet/c=1/l=4        55.4s ± 3%        45.4s ± 3%  -18.06%  (p=0.002 n=6+6)
Kubelet/c=4/l=0        37.4s ± 3%        29.9s ± 1%  -20.25%  (p=0.004 n=6+5)
Kubelet/c=4/l=4        48.1s ± 2%        39.0s ± 5%  -18.93%  (p=0.002 n=6+6)

name             old user-time/op  new user-time/op  delta
Kubelet/c=1/l=0         291s ± 1%         233s ± 1%  -19.96%  (p=0.002 n=6+6)
Kubelet/c=1/l=4         385s ± 1%         298s ± 1%  -22.51%  (p=0.002 n=6+6)
Kubelet/c=4/l=0         325s ± 0%         268s ± 1%  -17.48%  (p=0.004 n=5+6)
Kubelet/c=4/l=4         429s ± 1%         343s ± 1%  -20.08%  (p=0.002 n=6+6)

name             old sys-time/op   new sys-time/op   delta
Kubelet/c=1/l=0        25.1s ± 2%        20.9s ± 4%  -16.69%  (p=0.002 n=6+6)
Kubelet/c=1/l=4        31.2s ± 3%        24.4s ± 0%  -21.67%  (p=0.010 n=6+4)
Kubelet/c=4/l=0        30.2s ± 2%        25.6s ± 1%  -15.34%  (p=0.002 n=6+6)
Kubelet/c=4/l=4        37.3s ± 1%        30.9s ± 2%  -17.11%  (p=0.002 n=6+6)

Change-Id: Ie43eb3bbe1392cbb61c86792a17a57b33b9561f0
Reviewed-on: https://go-review.googlesource.com/106796
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-24 01:05:27 +00:00
Matthew Dempsky
7759b32a62 cmd/compile: replace Field.Nname.Pos with Field.Pos
For struct fields and methods, Field.Nname was only used to store
position information, which means we're allocating an entire ONAME
Node+Name+Param structure just for one field. We can optimize away
these ONAME allocations by instead adding a Field.Pos field.

Unfortunately, we can't get rid of Field.Nname, because it's needed
for function parameters, so Field grows a little bit and now has more
redundant information in those cases. However, that was already the
case (e.g., Field.Sym and Field.Nname.Sym), and it's still a net win
for allocations as demonstrated by the benchmarks below.

Additionally, by moving the ONAME allocation for function parameters
to funcargs, we can avoid allocating them for function parameters that
aren't used in corresponding function bodies (e.g., interface methods,
function-typed variables, and imported functions/methods without
inline bodies).

name       old time/op       new time/op       delta
Template         254ms ± 6%        251ms ± 6%  -1.04%  (p=0.000 n=487+488)
Unicode          128ms ± 7%        128ms ± 7%    ~     (p=0.294 n=482+467)
GoTypes          862ms ± 5%        860ms ± 4%    ~     (p=0.075 n=488+471)
Compiler         3.91s ± 4%        3.90s ± 4%  -0.39%  (p=0.000 n=468+473)

name       old user-time/op  new user-time/op  delta
Template         339ms ±14%        336ms ±14%  -1.02%  (p=0.001 n=498+494)
Unicode          176ms ±18%        176ms ±25%    ~     (p=0.940 n=491+499)
GoTypes          1.13s ± 8%        1.13s ± 9%    ~     (p=0.157 n=496+493)
Compiler         5.24s ± 6%        5.21s ± 6%  -0.57%  (p=0.000 n=485+489)

name       old alloc/op      new alloc/op      delta
Template        38.3MB ± 0%       37.3MB ± 0%  -2.58%  (p=0.000 n=499+497)
Unicode         29.1MB ± 0%       29.1MB ± 0%  -0.03%  (p=0.000 n=500+493)
GoTypes          116MB ± 0%        115MB ± 0%  -0.65%  (p=0.000 n=498+499)
Compiler         492MB ± 0%        487MB ± 0%  -1.00%  (p=0.000 n=497+498)

name       old allocs/op     new allocs/op     delta
Template          364k ± 0%         360k ± 0%  -1.15%  (p=0.000 n=499+499)
Unicode           336k ± 0%         336k ± 0%  -0.01%  (p=0.000 n=500+493)
GoTypes          1.16M ± 0%        1.16M ± 0%  -0.30%  (p=0.000 n=499+499)
Compiler         4.54M ± 0%        4.51M ± 0%  -0.58%  (p=0.000 n=494+495)

Passes toolstash-check -gcflags=-dwarf=false. Changes DWARF output
because position information is now tracked more precisely for
function parameters.

Change-Id: Ib8077d70d564cc448c5e4290baceab3a4396d712
Reviewed-on: https://go-review.googlesource.com/108217
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-04-23 18:05:57 +00:00