Unlikely to happen in practice, but easy enough to prevent and might
as well do so for completeness.
Fixes#28243.
Change-Id: I848c3af49cb923f088e9490c6a79373e182fad08
Reviewed-on: https://go-review.googlesource.com/c/142719
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
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>
This is supposed to print out function stack frames, but it's been
broken since golang.org/cl/38593, and no one has noticed.
Change-Id: Iad428a9097d452b878b1f8c5df22afd6f671ac2e
Reviewed-on: https://go-review.googlesource.com/c/145199
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
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>
Node.copy used to make a shallow copy of a node. Often, this is not
correct: If a node n's Orig field pointed to itself, the copy's Orig
field has to be adjusted to point to the copy. Otherwise, if n is
modified later, the copy's Orig appears modified as well (because it
points to n).
This was fixed for one specific case with
https://go-review.googlesource.com/c/go/+/136395 (issue #26855).
This change instead addresses copy in general:
In two cases we don't want the Orig adjustment as it causes escape
analysis output to fail (not match the existing error messages).
rawcopy is used in those cases.
In several cases Orig is set to the copy immediately after making
a copy; a new function sepcopy is used there.
Updates #26855.
Fixes#27765.
Change-Id: Idaadeb5c4b9a027daabd46a2361348f7a93f2b00
Reviewed-on: https://go-review.googlesource.com/136540
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Like the conv helper function but for creating OCONVNOP nodes
instead of OCONV nodes.
passes toolstash -cmp
Change-Id: Ib93ffe66590ebaa2b4fa552c81f1a2902e789d8e
Reviewed-on: https://go-review.googlesource.com/112597
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This reduces the API surface of Type slightly (for #25056), but also
makes it more consistent with the reflect and go/types APIs.
Passes toolstash-check.
Change-Id: Ief9a8eb461ae6e88895f347e2a1b7b8a62423222
Reviewed-on: https://go-review.googlesource.com/109138
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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>
There are a bunch of places where we generate functions: equality and
hash functions; method expression and promoted method wrappers; and
print/delete wrappers for defer/go statements.
This CL brings them in sync by:
1) Always using dclfunc and funcbody. Most were already using this,
but makepartialcall needed some changes.
2) Removing duplicate types.Markdcl/types.Popdcl calls. These are
already handled by dclfunc and funcbody.
3) Using structargs (already used by genwrapper) to construct new
param/result lists from existing types.
4) Always accessing the parameter ONAME nodes through Field.Nname
instead of poking into the ODCLFIELD. Also, since creating a slice of
the entire parameter list is common, extract this out into a
paramNnames helper function.
5) Add a Type.IsVariadic method to simplify identifying variadic
function types.
Passes toolstash-check -gcflags=-dwarf=false. DWARF output changes
because using structargs in makepartialcall changes the generated
parameter names.
Change-Id: I6661d3699afdbe7852ad60db5a4ec6eeb2b696e4
Reviewed-on: https://go-review.googlesource.com/108216
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Focus on "isfoo" funcs that take a *Node, and conver them to isFoo
methods instead. This makes for more idiomatic Go code, and also more
readable func names.
Found candidates with grep, and applied most changes with sed. The funcs
chosen were isgoconst, isnil, and isblank. All had the same signature,
func(*Node) bool.
While at it, camelCase the isliteral and iszero function names. Don't
move these to methods, as they are only used in the backend part of gc,
which might one day be split into a separate package.
Passes toolstash -cmp on std cmd.
Change-Id: I4df081b12d36c46c253167c8841c5a841f1c5a16
Reviewed-on: https://go-review.googlesource.com/105555
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
We'll always generate method expression wrappers for declared
interface types in their own package, so no need to generate them in
downstream packages.
Noticed by gri@ while looking into #21282.
Change-Id: I4fb7051b4e15297933da05fdd2b111d6b8f4178e
Reviewed-on: https://go-review.googlesource.com/106175
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
This used to be duplicated in methcmp and siglt, because Sig used its
own representation for Syms. Instead, just use Syms, and add a
(*Sym).Less method that both methcmp and siglt can use.
Also, prune some impossible cases purportedly related to blank
methods: the Go spec disallows blank methods in interface method sets,
and addmethod drops blank methods without actually recording them in
the type's method set.
Passes toolstash-check.
Updates #24693.
Change-Id: I24e981659b68504d71518160486989a82505f513
Reviewed-on: https://go-review.googlesource.com/105936
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There were multiple ad hoc ways to create method symbols, with subtle
and confusing differences between them. This CL unifies them into a
single well-documented encoding and implementation.
This introduces some inconsequential changes to symbol format for the
sake of simplicity and consistency. Two notable changes:
1) Symbol construction is now insensitive to the package currently
being compiled. Previously, non-exported methods on anonymous types
received different method symbols depending on whether the method was
local or imported.
2) Symbols for method values parenthesized non-pointer receiver types
and non-exported method names, and also always package-qualified
non-exported method names. Now they use the same rules as normal
method symbols.
The methodSym function is also now stricter about rejecting
non-sensical method/receiver combinations. Notably, this means that
typecheckfunc needs to call addmethod to validate the method before
calling declare, which also means we no longer emit errors about
redeclaring bogus methods.
Change-Id: I9501c7a53dd70ef60e5c74603974e5ecc06e2003
Reviewed-on: https://go-review.googlesource.com/104876
Reviewed-by: Robert Griesemer <gri@golang.org>
Originally, scalar values were directly stored within interface values
as long as they fit into a pointer-sized slot of memory. And since
interface method calls always pass the full pointer-sized value as the
receiver argument, value-narrowing wrappers were necessary to adapt to
the calling convention for methods with smaller receiver types.
However, for precise garbage collection, we now only store actual
pointers within interface values, so these wrappers are no longer
necessary.
Passes toolstash-check.
Change-Id: I5303bfeb8d0f11db619b5a5d06b37ac898588670
Reviewed-on: https://go-review.googlesource.com/104875
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
When making a shallow copy of a node, various methods were used,
including calling nod(OXXX, nil, nil) and then overwriting it, or
"n1 := *n" and then using &n1.
Add a copy method instead, simplifying all of those and making them
consistent.
Passes toolstash -cmp on std cmd.
Change-Id: I3f3fc88bad708edc712bf6d87214cda4ddc43b01
Reviewed-on: https://go-review.googlesource.com/72710
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Previously, n.Pos was reassigned to lineno when declare was called,
which might not match where the identifier actually appeared in the
source. This caused a loss of position precision for function
parameters (which were all declared at the last parameter's position),
and required some clumsy workarounds in bimport.go.
This CL changes declare to leave n.Pos alone and also fixes a few
places where n.Pos was not being set correctly.
Change-Id: Ibe5b5fd30609c684367207df701f9a1bfa82867f
Reviewed-on: https://go-review.googlesource.com/104275
Reviewed-by: Robert Griesemer <gri@golang.org>
We used to have three Sym flags for dealing with export/reexport:
Export, Package, and Exported.
Export and Package were used to distinguish whether a symbol is
exported or package-scope (i.e., mutually exclusive), except that for
local declarations Export served double-duty as tracking whether the
symbol had been added to exportlist.
Meanwhile, imported declarations that needed reexporting could be
added to exportlist multiple times, necessitating a flag to track
whether they'd already been written out by exporter.
Simplify all of these into a single OnExportList flag so that we can
ensure symbols on exportlist are present exactly once. Merge
reexportsym into exportsym so there's a single place where we append
to exportlist.
Code that used to set Exported to prevent a symbol from being exported
can now just set OnExportList before calling declare to prevent it
from even appearing on exportlist.
Lastly, drop the IsAlias check in exportsym: we call exportsym too
early for local symbols to detect if they're an alias, and we never
reexport aliases.
Passes toolstash-check.
Change-Id: Icdea3719105dc169fcd7651606589cd08b0a80ff
Reviewed-on: https://go-review.googlesource.com/103865
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Extract all rewrite-to-OLITERAL expressions to use a single setconst
helper function.
Does not pass toolstash-check for two reasons:
1) We now consistently clear Left/Right/etc when rewriting Nodes into
OLITERALs, which results in their inlining complexity being correctly
computed. So more functions can now be inlined.
2) We preserve Pos, so PC line tables change somewhat.
Change-Id: I2b5c293bee7c69c2ccd704677f5aba4ec40e3155
Reviewed-on: https://go-review.googlesource.com/103860
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
In expandmeth, we call expand1/expand0 to build a list of all
candidate methods to promote, and then we use dotpath to prune down
which names actually resolve to a promoted method and how.
However, previously we still computed "followsptr" based on the
expand1/expand0 traversal (which is depth-first), rather than
dotpath (which is breadth-first). The result is that we could
sometimes end up miscomputing whether a particular promoted method
involves a pointer traversal, which could result in bad code
generation for method trampolines.
Fixes#24547.
Change-Id: I57dc014466d81c165b05d78b98610dc3765b7a90
Reviewed-on: https://go-review.googlesource.com/102618
Reviewed-by: Robert Griesemer <gri@golang.org>
Slightly simplifies the code. Made sure to exclude the cases that would
change behavior, such as when the iterated value is a string, when the
index is modified within the body, or when the slice is modified.
Also checked that all the elements are of pointer type, to avoid the
corner case where non-pointer types could be copied by mistake.
Change-Id: Iea64feb2a9a6a4c94ada9ff3ace40ee173505849
Reviewed-on: https://go-review.googlesource.com/100557
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
By moving exported methods to the front of method lists, filtering
down to only the exported methods just needs a count of how many
exported methods exist, which the compiler can statically
provide. This allows getting rid of the exported method cache.
For #22075.
Change-Id: I8eeb274563a2940e1347c34d673f843ae2569064
Reviewed-on: https://go-review.googlesource.com/100846
Reviewed-by: Ian Lance Taylor <iant@golang.org>
By sorting method sets earlier, we can change the interface
satisfaction problem from taking O(NM) time to O(N+M). This is the
same algorithm already used by runtime and reflect for dynamic
interface satisfaction testing.
For #22075.
Change-Id: I3d889f0227f37704535739bbde11f5107b4eea17
Reviewed-on: https://go-review.googlesource.com/100845
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Currently, tail calls on x86 don't adjust the SP on return, so it's
important that the compiler produce a zero-sized frame and disable the
frame pointer. However, these constraints aren't necessary. For
example, on other architectures it's generally necessary to restore
the saved LR before a tail call, so obj simply makes this work.
Likewise, on x86, there's no reason we can't simply make this work.
Hence, this CL adjusts the compiler to use the same tail call
convention for x86 that we use on LR machines by producing a RET with
a target, rather than a JMP with a target. In fact, obj already
understands this convention for x86 except that it's buggy with
non-zero frame sizes. So we also fix this bug obj. As a result of
these fixes, the compiler no longer needs to mark wrappers as
NoFramePointer since it's now perfectly fine to save the frame
pointer.
In fact, this eliminates the only use of NoFramePointer in the
compiler, which will enable further cleanups.
This also fixes what is very nearly, but not quite, a code generation
bug. NoFramePointer becomes obj.NOFRAME in the object file, which on
ppc64 and s390x means to omit the saved LR. Hence, on these
architectures, NoFramePointer (and NOFRAME) is only safe to set on
leaf functions. However, on *most* architectures, wrappers aren't
necessarily leaf functions because they may call DUFFZERO. We're saved
on ppc64 and s390x only because the compiler doesn't have the rules to
produce DUFFZERO calls on these architectures. Hence, this only works
because the set of LR architectures that implement NOFRAME is disjoint
from the set where the compiler produces DUFFZERO operations. (I
discovered this whole mess when I attempted to add NOFRAME support to
arm.)
Change-Id: Icc589aeb86beacb850d0a6a80bd3024974a33947
Reviewed-on: https://go-review.googlesource.com/92035
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Also, with this change, error locations don't print absolute positions
in [] brackets following positions relative to line directives. To get
the absolute positions as well, specify the -L flag.
Fixes#22660.
Change-Id: I9ecfa254f053defba9c802222874155fa12fee2c
Reviewed-on: https://go-review.googlesource.com/77090
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
These are likely from the time when gc was written in C. There is no
need for any of these to be passed pointers, as the previous values are
not kept in any way, and the pointers are never nil. Others were left
untouched as they fell into one of these useful cases.
While at it, also turn some 0/1 integers into booleans.
Passes toolstash -cmp on std cmd.
Change-Id: Id3a9c9e84ef89536c4dc69a7fdbacd0fd7a76a9b
Reviewed-on: https://go-review.googlesource.com/72990
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Handle make(map[any]any) and make(map[any]any, hint) where
hint <= BUCKETSIZE special to allow for faster map initialization
and to improve binary size by using runtime calls with fewer arguments.
Given hint is smaller or equal to BUCKETSIZE in which case
overLoadFactor(hint, 0) is false and no buckets would be allocated by makemap:
* If hmap needs to be allocated on the stack then only hmap's hash0
field needs to be initialized and no call to makemap is needed.
* If hmap needs to be allocated on the heap then a new special
makehmap function will allocate hmap and intialize hmap's
hash0 field.
Reduces size of the godoc by ~36kb.
AMD64
name old time/op new time/op delta
NewEmptyMap 16.6ns ± 2% 5.5ns ± 2% -66.72% (p=0.000 n=10+10)
NewSmallMap 64.8ns ± 1% 56.5ns ± 1% -12.75% (p=0.000 n=9+10)
Updates #6853
Change-Id: I624e90da6775afaa061178e95db8aca674f44e9b
Reviewed-on: https://go-review.googlesource.com/61190
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
When compiling a package that defines a type T with method T.M, we
already compile and emit the wrapper method (*T).M. There's no need
for every package that uses T to do the same.
Change-Id: I3ca2659029907570f8b98d66111686435fad7ed0
Reviewed-on: https://go-review.googlesource.com/74412
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
* replace a copy of IsMethod with a call of it.
* a few more switches where they simplify the code.
* prefer composite literals over "n := new(...); n.x = y; ...".
* use defers to get rid of three goto labels.
* rewrite updateHasCall into two funcs to remove gotos.
Passes toolstash-check on std cmd.
Change-Id: Icb5442a89a87319ef4b640bbc5faebf41b193ef1
Reviewed-on: https://go-review.googlesource.com/72070
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The write barrier insertion has moved to the SSA backend's
writebarrier pass. There is still needwritebarrier function
left in the frontend. This function is used in two places:
- fncall, which is called in ascompatet, which is called in
walking OAS2FUNC. For OAS2FUNC, in order pass we've already
created temporaries, and there is no write barrier for the
assignments of these temporaries.
- updateHasCall, which updates the HasCall flag of a node. the
HasCall flag is then used in
- fncall, mentioned above.
- ascompatet. As mentioned above, this is an assignment to
a temporary, no write barrier.
- reorder1, which is always called with a list produced by
ascompatte, which is a list of assignments to stack, which
have no write barrier.
- vmatch1, which is called in oaslit with r.Op as OSTRUCTLIT,
OARRAYLIT, OSLICELIT, or OMAPLIT. There is no write barrier
in those literals.
Therefore, the needwritebarrier function is unnecessary. This
CL removes it.
Passes "toolstash -cmp" on std cmd.
Updates #17583.
Change-Id: I4b87ba8363d6583e4282a9e607a9ec8ce3ab124a
Reviewed-on: https://go-review.googlesource.com/43640
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reduce the scope of some. Also remove vars that were simply the index or
the value in a range statement. While at it, remove a var that was
exactly the length of a slice.
Also replaced 'bad' with a more clear 'errored' of type bool, and
renamed a single-char name with a comment to a name that is
self-explanatory.
And removed a few unnecessary Index calls within loops.
Passes toolstash -cmp on std cmd.
Change-Id: I26eee5f04e8f7e5418e43e25dca34f89cca5c80a
Reviewed-on: https://go-review.googlesource.com/70930
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
After we detect errors, the AST is in a precarious state and more
likely to trip useless ICE failures. Instead let the user fix any
existing errors and see if the ICE persists. This makes Fatalf more
consistent with how panics are handled by hidePanic.
While here, also fix detection for release versions: release version
strings begin with "go" ("go1.8", "go1.9.1", etc), not "release".
Fixes#22252.
Change-Id: I1c400af62fb49dd979b96e1bf0fb295a81c8b336
Reviewed-on: https://go-review.googlesource.com/70850
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
ORETJMP doesn't need an ONAME if we just set the target method on Sym
instead of Left. Conveniently, this is where fmt.go was looking for it
anyway.
Change the iface parameter and global compiling_wrappers to bool.
Passes toolstash-check.
Change-Id: I5333f8bcb4e06bf8161808041125eb95c439aafe
Reviewed-on: https://go-review.googlesource.com/68252
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Robert Griesemer <gri@golang.org>
Rework the logic to remove them. These were the low hanging fruit,
with labels that were used only once and logic that was fairly
straightforward.
Change-Id: I02a01c59c247b8b2972d8d73ff23f96f271de038
Reviewed-on: https://go-review.googlesource.com/63410
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Rather than emitting spaces and newlines for println
as we walk the expression, construct it all up front.
This enables further optimizations.
This requires using printstring instead of print in
the implementation of printsp and printnl,
on pain of infinite recursion.
That's ok; it's more efficient anyway, and just as simple.
While we're here, do it for other print routines as well.
Change-Id: I61d7df143810e00710c4d4d948d904007a7fd190
Reviewed-on: https://go-review.googlesource.com/55097
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Mostly node and position parameters that are no longer used.
Also remove an unnecessary node variable while at it.
Found with github.com/mvdan/unparam.
Change-Id: I88f9bd5d20bfc5b0f6f63ea81869daa246175061
Reviewed-on: https://go-review.googlesource.com/54130
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This doesn't change the existing restriction with disallows
spaces in import paths (as found in an import declaration).
It simply permits packages to be under a directory name that
may contain spaces.
Verified manually that it works. This could use a test, but the
change is trivial. We also can't use the existing test framework
(under test/) because the way those tests are run with test/run.go,
the mechanims for compiling a directory, even if it contains blanks
it its name, does't produce compiler paths with blanks
(the compilation is local).
Fixes#20306.
Change-Id: I6cbffb86c3394347897c3c94b110da0aadc5bfdf
Reviewed-on: https://go-review.googlesource.com/46001
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
This CL adds initial support for concurrent backend compilation.
BACKGROUND
The compiler currently consists (very roughly) of the following phases:
1. Initialization.
2. Lexing and parsing into the cmd/compile/internal/syntax AST.
3. Translation into the cmd/compile/internal/gc AST.
4. Some gc AST passes: typechecking, escape analysis, inlining,
closure handling, expression evaluation ordering (order.go),
and some lowering and optimization (walk.go).
5. Translation into the cmd/compile/internal/ssa SSA form.
6. Optimization and lowering of SSA form.
7. Translation from SSA form to assembler instructions.
8. Translation from assembler instructions to machine code.
9. Writing lots of output: machine code, DWARF symbols,
type and reflection info, export data.
Phase 2 was already concurrent as of Go 1.8.
Phase 3 is planned for eventual removal;
we hope to go straight from syntax AST to SSA.
Phases 5–8 are per-function; this CL adds support for
processing multiple functions concurrently.
The slowest phases in the compiler are 5 and 6,
so this offers the opportunity for some good speed-ups.
Unfortunately, it's not quite that straightforward.
In the current compiler, the latter parts of phase 4
(order, walk) are done function-at-a-time as needed.
Making order and walk concurrency-safe proved hard,
and they're not particularly slow, so there wasn't much reward.
To enable phases 5–8 to be done concurrently,
when concurrent backend compilation is requested,
we complete phase 4 for all functions
before starting later phases for any functions.
Also, in reality, we automatically generate new
functions in phase 9, such as method wrappers
and equality and has routines.
Those new functions then go through phases 4–8.
This CL disables concurrent backend compilation
after the first, big, user-provided batch of
functions has been compiled.
This is done to keep things simple,
and because the autogenerated functions
tend to be small, few, simple, and fast to compile.
USAGE
Concurrent backend compilation still defaults to off.
To set the number of functions that may be backend-compiled
concurrently, use the compiler flag -c.
In future work, cmd/go will automatically set -c.
Furthermore, this CL has been intentionally written
so that the c=1 path has no backend concurrency whatsoever,
not even spawning any goroutines.
This helps ensure that, should problems arise
late in the development cycle,
we can simply have cmd/go set c=1 always,
and revert to the original compiler behavior.
MUTEXES
Most of the work required to make concurrent backend
compilation safe has occurred over the past month.
This CL adds a handful of mutexes to get the rest of the way there;
they are the mutexes that I didn't see a clean way to avoid.
Some of them may still be eliminable in future work.
In no particular order:
* gc.funcsymsmu. The global funcsyms slice is populated
lazily when we need function symbols for closures.
This occurs during gc AST to SSA translation.
The function funcsym also does a package lookup,
which is a source of races on types.Pkg.Syms;
funcsymsmu also covers that package lookup.
This mutex is low priority: it adds a single global,
it is in an infrequently used code path, and it is low contention.
Since funcsyms may now be added in any order,
we must sort them to preserve reproducible builds.
* gc.largeStackFramesMu. We don't discover until after SSA compilation
that a function's stack frame is gigantic.
Recording that error happens basically never,
but it does happen concurrently.
Fix with a low priority mutex and sorting.
* obj.Link.hashmu. ctxt.hash stores the mapping from
types.Syms (compiler symbols) to obj.LSyms (linker symbols).
It is accessed fairly heavily through all the phases.
This is the only heavily contended mutex.
* gc.signatlistmu. The global signatlist map is
populated with types through several of the concurrent phases,
including notably via ngotype during DWARF generation.
It is low priority for removal.
* gc.typepkgmu. Looking up symbols in the types package
happens a fair amount during backend compilation
and DWARF generation, particularly via ngotype.
This mutex helps us to avoid a broader mutex on types.Pkg.Syms.
It has low-to-moderate contention.
* types.internedStringsmu. gc AST to SSA conversion and
some SSA work introduce new autotmps.
Those autotmps have their names interned to reduce allocations.
That interning requires protecting types.internedStrings.
The autotmp names are heavily re-used, and the mutex
overhead and contention here are low, so it is probably
a worthwhile performance optimization to keep this mutex.
TESTING
I have been testing this code locally by running
'go install -race cmd/compile'
and then doing
'go build -a -gcflags=-c=128 std cmd'
for all architectures and a variety of compiler flags.
This obviously needs to be made part of the builders,
but it is too expensive to make part of all.bash.
I have filed #19962 for this.
REPRODUCIBLE BUILDS
This version of the compiler generates reproducible builds.
Testing reproducible builds also needs automation, however,
and is also too expensive for all.bash.
This is #19961.
Also of note is that some of the compiler flags used by 'toolstash -cmp'
are currently incompatible with concurrent backend compilation.
They still work fine with c=1.
Time will tell whether this is a problem.
NEXT STEPS
* Continue to find and fix races and bugs,
using a combination of code inspection, fuzzing,
and hopefully some community experimentation.
I do not know of any outstanding races,
but there probably are some.
* Improve testing.
* Improve performance, for many values of c.
* Integrate with cmd/go and fine tune.
* Support concurrent compilation with the -race flag.
It is a sad irony that it does not yet work.
* Minor code cleanup that has been deferred during
the last month due to uncertainty about the
ultimate shape of this CL.
PERFORMANCE
Here's the buried lede, at last. :)
All benchmarks are from my 8 core 2.9 GHz Intel Core i7 darwin/amd64 laptop.
First, going from tip to this CL with c=1 has almost no impact.
name old time/op new time/op delta
Template 195ms ± 3% 194ms ± 5% ~ (p=0.370 n=30+29)
Unicode 86.6ms ± 3% 87.0ms ± 7% ~ (p=0.958 n=29+30)
GoTypes 548ms ± 3% 555ms ± 4% +1.35% (p=0.001 n=30+28)
Compiler 2.51s ± 2% 2.54s ± 2% +1.17% (p=0.000 n=28+30)
SSA 5.16s ± 3% 5.16s ± 2% ~ (p=0.910 n=30+29)
Flate 124ms ± 5% 124ms ± 4% ~ (p=0.947 n=30+30)
GoParser 146ms ± 3% 146ms ± 3% ~ (p=0.150 n=29+28)
Reflect 354ms ± 3% 352ms ± 4% ~ (p=0.096 n=29+29)
Tar 107ms ± 5% 106ms ± 3% ~ (p=0.370 n=30+29)
XML 200ms ± 4% 201ms ± 4% ~ (p=0.313 n=29+28)
[Geo mean] 332ms 333ms +0.10%
name old user-time/op new user-time/op delta
Template 227ms ± 5% 225ms ± 5% ~ (p=0.457 n=28+27)
Unicode 109ms ± 4% 109ms ± 5% ~ (p=0.758 n=29+29)
GoTypes 713ms ± 4% 721ms ± 5% ~ (p=0.051 n=30+29)
Compiler 3.36s ± 2% 3.38s ± 3% ~ (p=0.146 n=30+30)
SSA 7.46s ± 3% 7.47s ± 3% ~ (p=0.804 n=30+29)
Flate 146ms ± 7% 147ms ± 3% ~ (p=0.833 n=29+27)
GoParser 179ms ± 5% 179ms ± 5% ~ (p=0.866 n=30+30)
Reflect 431ms ± 4% 429ms ± 4% ~ (p=0.593 n=29+30)
Tar 124ms ± 5% 123ms ± 5% ~ (p=0.140 n=29+29)
XML 243ms ± 4% 242ms ± 7% ~ (p=0.404 n=29+29)
[Geo mean] 415ms 415ms +0.02%
name old obj-bytes new obj-bytes delta
Template 382k ± 0% 382k ± 0% ~ (all equal)
Unicode 203k ± 0% 203k ± 0% ~ (all equal)
GoTypes 1.18M ± 0% 1.18M ± 0% ~ (all equal)
Compiler 3.98M ± 0% 3.98M ± 0% ~ (all equal)
SSA 8.28M ± 0% 8.28M ± 0% ~ (all equal)
Flate 230k ± 0% 230k ± 0% ~ (all equal)
GoParser 287k ± 0% 287k ± 0% ~ (all equal)
Reflect 1.00M ± 0% 1.00M ± 0% ~ (all equal)
Tar 190k ± 0% 190k ± 0% ~ (all equal)
XML 416k ± 0% 416k ± 0% ~ (all equal)
[Geo mean] 660k 660k +0.00%
Comparing this CL to itself, from c=1 to c=2
improves real times 20-30%, costs 5-10% more CPU time,
and adds about 2% alloc.
The allocation increase comes from allocating more ssa.Caches.
name old time/op new time/op delta
Template 202ms ± 3% 149ms ± 3% -26.15% (p=0.000 n=49+49)
Unicode 87.4ms ± 4% 84.2ms ± 3% -3.68% (p=0.000 n=48+48)
GoTypes 560ms ± 2% 398ms ± 2% -28.96% (p=0.000 n=49+49)
Compiler 2.46s ± 3% 1.76s ± 2% -28.61% (p=0.000 n=48+46)
SSA 6.17s ± 2% 4.04s ± 1% -34.52% (p=0.000 n=49+49)
Flate 126ms ± 3% 92ms ± 2% -26.81% (p=0.000 n=49+48)
GoParser 148ms ± 4% 107ms ± 2% -27.78% (p=0.000 n=49+48)
Reflect 361ms ± 3% 281ms ± 3% -22.10% (p=0.000 n=49+49)
Tar 109ms ± 4% 86ms ± 3% -20.81% (p=0.000 n=49+47)
XML 204ms ± 3% 144ms ± 2% -29.53% (p=0.000 n=48+45)
name old user-time/op new user-time/op delta
Template 246ms ± 9% 246ms ± 4% ~ (p=0.401 n=50+48)
Unicode 109ms ± 4% 111ms ± 4% +1.47% (p=0.000 n=44+50)
GoTypes 728ms ± 3% 765ms ± 3% +5.04% (p=0.000 n=46+50)
Compiler 3.33s ± 3% 3.41s ± 2% +2.31% (p=0.000 n=49+48)
SSA 8.52s ± 2% 9.11s ± 2% +6.93% (p=0.000 n=49+47)
Flate 149ms ± 4% 161ms ± 3% +8.13% (p=0.000 n=50+47)
GoParser 181ms ± 5% 192ms ± 2% +6.40% (p=0.000 n=49+46)
Reflect 452ms ± 9% 474ms ± 2% +4.99% (p=0.000 n=50+48)
Tar 126ms ± 6% 136ms ± 4% +7.95% (p=0.000 n=50+49)
XML 247ms ± 5% 264ms ± 3% +6.94% (p=0.000 n=48+50)
name old alloc/op new alloc/op delta
Template 38.8MB ± 0% 39.3MB ± 0% +1.48% (p=0.008 n=5+5)
Unicode 29.8MB ± 0% 30.2MB ± 0% +1.19% (p=0.008 n=5+5)
GoTypes 113MB ± 0% 114MB ± 0% +0.69% (p=0.008 n=5+5)
Compiler 443MB ± 0% 447MB ± 0% +0.95% (p=0.008 n=5+5)
SSA 1.25GB ± 0% 1.26GB ± 0% +0.89% (p=0.008 n=5+5)
Flate 25.3MB ± 0% 25.9MB ± 1% +2.35% (p=0.008 n=5+5)
GoParser 31.7MB ± 0% 32.2MB ± 0% +1.59% (p=0.008 n=5+5)
Reflect 78.2MB ± 0% 78.9MB ± 0% +0.91% (p=0.008 n=5+5)
Tar 26.6MB ± 0% 27.0MB ± 0% +1.80% (p=0.008 n=5+5)
XML 42.4MB ± 0% 43.4MB ± 0% +2.35% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Template 379k ± 0% 378k ± 0% ~ (p=0.421 n=5+5)
Unicode 322k ± 0% 321k ± 0% ~ (p=0.222 n=5+5)
GoTypes 1.14M ± 0% 1.14M ± 0% ~ (p=0.548 n=5+5)
Compiler 4.12M ± 0% 4.11M ± 0% -0.14% (p=0.032 n=5+5)
SSA 9.72M ± 0% 9.72M ± 0% ~ (p=0.421 n=5+5)
Flate 234k ± 1% 234k ± 0% ~ (p=0.421 n=5+5)
GoParser 316k ± 1% 315k ± 0% ~ (p=0.222 n=5+5)
Reflect 980k ± 0% 979k ± 0% ~ (p=0.095 n=5+5)
Tar 249k ± 1% 249k ± 1% ~ (p=0.841 n=5+5)
XML 392k ± 0% 391k ± 0% ~ (p=0.095 n=5+5)
From c=1 to c=4, real time is down ~40%, CPU usage up 10-20%, alloc up ~5%:
name old time/op new time/op delta
Template 203ms ± 3% 131ms ± 5% -35.45% (p=0.000 n=50+50)
Unicode 87.2ms ± 4% 84.1ms ± 2% -3.61% (p=0.000 n=48+47)
GoTypes 560ms ± 4% 310ms ± 2% -44.65% (p=0.000 n=50+49)
Compiler 2.47s ± 3% 1.41s ± 2% -43.10% (p=0.000 n=50+46)
SSA 6.17s ± 2% 3.20s ± 2% -48.06% (p=0.000 n=49+49)
Flate 126ms ± 4% 74ms ± 2% -41.06% (p=0.000 n=49+48)
GoParser 148ms ± 4% 89ms ± 3% -39.97% (p=0.000 n=49+50)
Reflect 360ms ± 3% 242ms ± 3% -32.81% (p=0.000 n=49+49)
Tar 108ms ± 4% 73ms ± 4% -32.48% (p=0.000 n=50+49)
XML 203ms ± 3% 119ms ± 3% -41.56% (p=0.000 n=49+48)
name old user-time/op new user-time/op delta
Template 246ms ± 9% 287ms ± 9% +16.98% (p=0.000 n=50+50)
Unicode 109ms ± 4% 118ms ± 5% +7.56% (p=0.000 n=46+50)
GoTypes 735ms ± 4% 806ms ± 2% +9.62% (p=0.000 n=50+50)
Compiler 3.34s ± 4% 3.56s ± 2% +6.78% (p=0.000 n=49+49)
SSA 8.54s ± 3% 10.04s ± 3% +17.55% (p=0.000 n=50+50)
Flate 149ms ± 6% 176ms ± 3% +17.82% (p=0.000 n=50+48)
GoParser 181ms ± 5% 213ms ± 3% +17.47% (p=0.000 n=50+50)
Reflect 453ms ± 6% 499ms ± 2% +10.11% (p=0.000 n=50+48)
Tar 126ms ± 5% 149ms ±11% +18.76% (p=0.000 n=50+50)
XML 246ms ± 5% 287ms ± 4% +16.53% (p=0.000 n=49+50)
name old alloc/op new alloc/op delta
Template 38.8MB ± 0% 40.4MB ± 0% +4.21% (p=0.008 n=5+5)
Unicode 29.8MB ± 0% 30.9MB ± 0% +3.68% (p=0.008 n=5+5)
GoTypes 113MB ± 0% 116MB ± 0% +2.71% (p=0.008 n=5+5)
Compiler 443MB ± 0% 455MB ± 0% +2.75% (p=0.008 n=5+5)
SSA 1.25GB ± 0% 1.27GB ± 0% +1.84% (p=0.008 n=5+5)
Flate 25.3MB ± 0% 26.9MB ± 1% +6.31% (p=0.008 n=5+5)
GoParser 31.7MB ± 0% 33.2MB ± 0% +4.61% (p=0.008 n=5+5)
Reflect 78.2MB ± 0% 80.2MB ± 0% +2.53% (p=0.008 n=5+5)
Tar 26.6MB ± 0% 27.9MB ± 0% +5.19% (p=0.008 n=5+5)
XML 42.4MB ± 0% 44.6MB ± 0% +5.20% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Template 380k ± 0% 379k ± 0% -0.39% (p=0.032 n=5+5)
Unicode 321k ± 0% 321k ± 0% ~ (p=0.841 n=5+5)
GoTypes 1.14M ± 0% 1.14M ± 0% ~ (p=0.421 n=5+5)
Compiler 4.12M ± 0% 4.14M ± 0% +0.52% (p=0.008 n=5+5)
SSA 9.72M ± 0% 9.76M ± 0% +0.37% (p=0.008 n=5+5)
Flate 234k ± 1% 234k ± 1% ~ (p=0.690 n=5+5)
GoParser 316k ± 0% 317k ± 1% ~ (p=0.841 n=5+5)
Reflect 981k ± 0% 981k ± 0% ~ (p=1.000 n=5+5)
Tar 250k ± 0% 249k ± 1% ~ (p=0.151 n=5+5)
XML 393k ± 0% 392k ± 0% ~ (p=0.056 n=5+5)
Going beyond c=4 on my machine tends to increase CPU time and allocs
without impacting real time.
The CPU time numbers matter, because when there are many concurrent
compilation processes, that will impact the overall throughput.
The numbers above are in many ways the best case scenario;
we can take full advantage of all cores.
Fortunately, the most common compilation scenario is incremental
re-compilation of a single package during a build/test cycle.
Updates #15756
Change-Id: I6725558ca2069edec0ac5b0d1683105a9fff6bea
Reviewed-on: https://go-review.googlesource.com/40693
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
