Commit graph

144 commits

Author SHA1 Message Date
Alessandro Arzilli
c8b889cc48 cmd/compile: output DWARF lexical blocks for local variables
Change compiler and linker to emit DWARF lexical blocks in debug_info.
Version of debug_info is updated from DWARF v.2 to DWARF v.3 since version 2
does not allow lexical blocks with discontinuous ranges.

Second attempt at https://go-review.googlesource.com/#/c/29591/

Remaining open problems:
- scope information is removed from inlined functions
- variables in debug_info do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, before its declaration.

Updates golang/go#12899, golang/go#6913

Change-Id: I0e260a45b564d14a87b88974eb16c5387cb410a5
Reviewed-on: https://go-review.googlesource.com/36879
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 18:15:06 +00:00
Robert Griesemer
f68f292820 cmd/compile: factor out Pkg, Sym, and Type into package types
- created new package cmd/compile/internal/types
- moved Pkg, Sym, Type to new package
- to break cycles, for now we need the (ugly) types/utils.go
  file which contains a handful of functions that must be installed
  early by the gc frontend
- to break cycles, for now we need two functions to convert between
  *gc.Node and *types.Node (the latter is a dummy type)
- adjusted the gc's code to use the new package and the conversion
  functions as needed
- made several Pkg, Sym, and Type methods functions as needed
- renamed constructors typ, typPtr, typArray, etc. to types.New,
  types.NewPtr, types.NewArray, etc.

Passes toolstash-check -all.

Change-Id: I8adfa5e85c731645d0a7fd2030375ed6ebf54b72
Reviewed-on: https://go-review.googlesource.com/39855
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 03:04:00 +00:00
Josh Bleecher Snyder
c311488283 cmd/internal/obj: remove Linklookup
It was simply a wrapper around Link.Lookup.
Unwrap everything.

CL prepared using eg with template:

package p

import "cmd/internal/obj"

func before(ctxt *obj.Link, name string, version int) *obj.LSym {
	return obj.Linklookup(ctxt, name, version)
}

func after(ctxt *obj.Link, name string, version int) *obj.LSym {
	return ctxt.Lookup(name, version)
}

Then one comment in cmd/asm/internal/asm/parse.go
was manually updated (and gofmt'ed!),
and func Linklookup deleted.

Passes toolstash-check (as a sanity measure).

Change-Id: Icc4d56b0b2b5c8888d3184c1898c48359ea1e638
Reviewed-on: https://go-review.googlesource.com/39715
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-06 19:01:41 +00:00
Josh Bleecher Snyder
5c359d8083 cmd/compile: add Prog cache to Progs
The existing bulk/cached Prog allocator, Ctxt.NewProg, is not concurrency-safe.
This CL moves Prog allocation to its clients, the compiler and the assembler.

The assembler is so fast and generates so few Progs that it does not need
optimization of Prog allocation. I could not generate measureable changes.
And even if I could, the assembly is a miniscule portion of build times.

The compiler already has a natural place to manage Prog allocation;
this CL migrates the Prog cache there.
It will be made concurrency-safe in a later CL by
partitioning the Prog cache into chunks and assigning each chunk
to a different goroutine to manage.

This CL does cause a performance degradation when the compiler
is invoked with the -S flag (to dump assembly).
However, such usage is rare and almost always done manually.
The one instance I know of in a test is TestAssembly
in cmd/compile/internal/gc, and I did not detect
a measurable performance impact there.

Passes toolstash-check -all.
Minor compiler performance impact.

Updates #15756

Performance impact from just this CL:

name        old time/op     new time/op     delta
Template        213ms ± 4%      213ms ± 4%    ~     (p=0.571 n=49+49)
Unicode        89.1ms ± 3%     89.4ms ± 3%    ~     (p=0.388 n=47+48)
GoTypes         581ms ± 2%      584ms ± 3%  +0.56%  (p=0.019 n=47+48)
SSA             6.48s ± 2%      6.53s ± 2%  +0.84%  (p=0.000 n=47+49)
Flate           128ms ± 4%      128ms ± 4%    ~     (p=0.832 n=49+49)
GoParser        152ms ± 3%      152ms ± 3%    ~     (p=0.815 n=48+47)
Reflect         371ms ± 4%      371ms ± 3%    ~     (p=0.617 n=50+47)
Tar             112ms ± 4%      112ms ± 3%    ~     (p=0.724 n=49+49)
XML             208ms ± 3%      208ms ± 4%    ~     (p=0.678 n=49+50)
[Geo mean]      284ms           285ms       +0.18%

name        old user-ns/op  new user-ns/op  delta
Template         251M ± 7%       252M ±11%    ~     (p=0.704 n=49+50)
Unicode          107M ± 7%       108M ± 5%  +1.25%  (p=0.036 n=50+49)
GoTypes          738M ± 3%       740M ± 3%    ~     (p=0.305 n=49+48)
SSA             8.83G ± 2%      8.86G ± 4%    ~     (p=0.098 n=47+50)
Flate            146M ± 6%       147M ± 3%    ~     (p=0.584 n=48+41)
GoParser         178M ± 6%       179M ± 5%  +0.93%  (p=0.036 n=49+48)
Reflect          441M ± 4%       446M ± 7%    ~     (p=0.218 n=44+49)
Tar              126M ± 5%       126M ± 5%    ~     (p=0.766 n=48+49)
XML              245M ± 5%       244M ± 4%    ~     (p=0.359 n=50+50)
[Geo mean]       341M            342M       +0.51%

Performance impact from this CL combined with its parent:

name        old time/op     new time/op     delta
Template        213ms ± 3%      214ms ± 4%    ~     (p=0.685 n=47+50)
Unicode        89.8ms ± 6%     90.5ms ± 6%    ~     (p=0.055 n=50+50)
GoTypes         584ms ± 3%      585ms ± 2%    ~     (p=0.710 n=49+47)
SSA             6.50s ± 2%      6.53s ± 2%  +0.39%  (p=0.011 n=46+50)
Flate           128ms ± 3%      128ms ± 4%    ~     (p=0.855 n=47+49)
GoParser        152ms ± 3%      152ms ± 3%    ~     (p=0.666 n=49+49)
Reflect         371ms ± 3%      372ms ± 3%    ~     (p=0.298 n=48+48)
Tar             112ms ± 5%      113ms ± 3%    ~     (p=0.107 n=49+49)
XML             208ms ± 3%      208ms ± 2%    ~     (p=0.881 n=50+49)
[Geo mean]      285ms           285ms       +0.26%

name        old user-ns/op  new user-ns/op  delta
Template         254M ± 9%       252M ± 8%    ~     (p=0.290 n=49+50)
Unicode          106M ± 6%       108M ± 7%  +1.44%  (p=0.034 n=50+50)
GoTypes          741M ± 4%       743M ± 4%    ~     (p=0.992 n=50+49)
SSA             8.86G ± 2%      8.83G ± 3%    ~     (p=0.158 n=47+49)
Flate            147M ± 4%       148M ± 5%    ~     (p=0.832 n=50+49)
GoParser         179M ± 5%       178M ± 5%    ~     (p=0.370 n=48+50)
Reflect          441M ± 6%       445M ± 7%    ~     (p=0.246 n=45+47)
Tar              126M ± 6%       126M ± 6%    ~     (p=0.815 n=49+50)
XML              244M ± 3%       245M ± 4%    ~     (p=0.190 n=50+50)
[Geo mean]       342M            342M       +0.17%

Change-Id: I020f1c079d495fbe2e15ccb51e1ea2cc1b5a1855
Reviewed-on: https://go-review.googlesource.com/39634
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-06 04:53:50 +00:00
Josh Bleecher Snyder
877574725b cmd/compile: enforce that all nodes are used when generating DWARF
No particular need for this,
but it's nice to enforce invariants
when they are available.

Change-Id: Ia6fa88dc4116f65dac2879509746e123e2c1862a
Reviewed-on: https://go-review.googlesource.com/39201
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-03 01:23:06 +00:00
Josh Bleecher Snyder
3751513562 cmd/compile: don't modify nodfp in AllocFrame
nodfp is a global, so modifying it is unsafe in a concurrent backend.
It is also not necessary, since the Used marks
are only relevant for nodes in fn.Dcl.
For good measure, mark nodfp as always used.

Passes toolstash-check.

Updates #15756

Change-Id: I5320459f5eced2898615a17b395a10c1064bcaf5
Reviewed-on: https://go-review.googlesource.com/39200
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-03 01:22:58 +00:00
Josh Bleecher Snyder
4927b9a9ff cmd/compile: remove makefuncdatasym_nsym global
This causes a minor reduction in allocations,
because the old funcdatasym names were
being interned unnecessarily.

Updates #15756

name       old alloc/op    new alloc/op    delta
Template      39.9MB ± 0%     39.9MB ± 0%    ~     (p=0.280 n=10+10)
Unicode       29.9MB ± 0%     29.8MB ± 0%  -0.26%  (p=0.000 n=10+10)
GoTypes        113MB ± 0%      113MB ± 0%  -0.12%  (p=0.000 n=10+10)
SSA            855MB ± 0%      855MB ± 0%  -0.03%  (p=0.001 n=10+10)
Flate         25.4MB ± 0%     25.3MB ± 0%  -0.30%  (p=0.000 n=10+10)
GoParser      31.9MB ± 0%     31.8MB ± 0%    ~     (p=0.065 n=10+9)
Reflect       78.4MB ± 0%     78.2MB ± 0%  -0.15%  (p=0.000 n=9+10)
Tar           26.7MB ± 0%     26.7MB ± 0%  -0.17%  (p=0.000 n=9+10)
XML           42.3MB ± 0%     42.4MB ± 0%  +0.07%  (p=0.011 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        390k ± 0%       390k ± 0%    ~     (p=0.905 n=9+10)
Unicode         319k ± 1%       319k ± 1%    ~     (p=0.724 n=10+10)
GoTypes        1.14M ± 0%      1.14M ± 0%    ~     (p=0.393 n=10+10)
SSA            7.60M ± 0%      7.60M ± 0%    ~     (p=0.604 n=9+10)
Flate           235k ± 1%       234k ± 1%    ~     (p=0.105 n=10+10)
GoParser        317k ± 0%       316k ± 1%    ~     (p=0.280 n=10+10)
Reflect         979k ± 0%       979k ± 0%    ~     (p=0.315 n=10+10)
Tar             251k ± 0%       251k ± 1%    ~     (p=0.762 n=8+10)
XML             393k ± 0%       394k ± 1%    ~     (p=0.095 n=9+10)

name       old text-bytes  new text-bytes  delta
HelloSize       684k ± 0%       684k ± 0%    ~     (all equal)

name       old data-bytes  new data-bytes  delta
HelloSize       138k ± 0%       138k ± 0%    ~     (all equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize      1.03M ± 0%      1.03M ± 0%    ~     (all equal)

Change-Id: Idba33da4e89c325984ac46e4852cf12e4a7fd1a9
Reviewed-on: https://go-review.googlesource.com/39032
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-03-31 19:53:26 +00:00
Josh Bleecher Snyder
0323895cc0 cmd/compile: catch and report nowritebarrier violations later
Prior to this CL, the SSA backend reported violations
of the //go:nowritebarrier annotation immediately.
This necessitated emitting errors during SSA compilation,
which is not compatible with a concurrent backend.

Instead, check for such violations later.
We already save the data required to do a late check
for violations of the //go:nowritebarrierrec annotation.
Use the same data, and check //go:nowritebarrier at the same time.

One downside to doing this is that now only a single
violation will be reported per function.
Given that this is for the runtime only,
and violations are rare, this seems an acceptable cost.

While we are here, remove several 'nerrors != 0' checks
that are rendered pointless.

Updates #15756
Fixes #19250 (as much as it ever can be)

Change-Id: Ia44c4ad5b6fd6f804d9f88d9571cec8d23665cb3
Reviewed-on: https://go-review.googlesource.com/38973
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-03-31 16:31:20 +00:00
Josh Bleecher Snyder
ca33e10971 cmd/compile: rework reporting of oversized stack frames
We don't support stack frames over 2GB.
Rather than detect this during backend compilation,
check for it at the end of compilation.
This is arguably a more accurate check anyway,
since it takes into account the full frame,
including local stack, arguments, and arch-specific
rounding, although it's unlikely anyone would ever notice.

Also, rather than reporting the error right away,
take note of it and report it later, at the top level.
This is not relevant now, but it will help with making
the backend concurrent, as the append to the list of
oversized functions can be cheaply protected by a plain mutex.

Updates #15756
Updates #19250

Change-Id: Id3fa21906616d62e9dc66e27a17fd5f83304e96e
Reviewed-on: https://go-review.googlesource.com/38972
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-03-31 16:31:09 +00:00
Josh Bleecher Snyder
7efb0779be cmd/compile: remove scratchFpMem global
Instead, add a scratchFpMem field to ssafn,
so that it may be passed on to genssa.

Updates #15756

Change-Id: Icdeae290d3098d14d31659fa07a9863964bb76ed
Reviewed-on: https://go-review.googlesource.com/38728
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-30 22:09:48 +00:00
Josh Bleecher Snyder
beb833f124 cmd/compile: initialize SSA runtime functions in initssaconfig
This is a better home for it.

Change-Id: I7ce96c16378d841613edaa53c07347b0ac99ea6e
Reviewed-on: https://go-review.googlesource.com/38970
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-30 20:44:51 +00:00
Josh Bleecher Snyder
ef1ab0f0f4 cmd/compile: enforce no uses of Curfn in backend
Updates #15756

Change-Id: Id8d65ca9a3f1a7f9ea43e26cdd5e7d3befef8ba0
Reviewed-on: https://go-review.googlesource.com/38593
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-25 00:09:33 +00:00
Josh Bleecher Snyder
34975095d0 cmd/compile: provide pos and curfn to temp
Concurrent compilation requires providing an
explicit position and curfn to temp.
This implementation of tempAt temporarily
continues to use the globals lineno and Curfn,
so as not to collide with mdempsky's
work for #19683 eliminating the Curfn dependency
from func nod.

Updates #15756
Updates #19683

Change-Id: Ib3149ca4b0740e9f6eea44babc6f34cdd63028a9
Reviewed-on: https://go-review.googlesource.com/38592
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-25 00:09:21 +00:00
Josh Bleecher Snyder
6652572b75 cmd/compile: thread Curfn through to debuginfo
Updates #15756

Change-Id: I860dd45cae9d851c7844654621bbc99efe7c7f03
Reviewed-on: https://go-review.googlesource.com/38591
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-24 16:22:58 +00:00
Josh Bleecher Snyder
c3a50ad3c7 cmd/compile: eliminate Prog-related globals
Introduce a new type, gc.Progs, to manage
generation of Progs for a function.
Use it to replace globals pc and pcloc.

Passes toolstash-check -all.

Updates #15756

Change-Id: I2206998d7c58fe2a76b620904909f2e1cec8a57d
Reviewed-on: https://go-review.googlesource.com/38418
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-23 16:52:28 +00:00
Josh Bleecher Snyder
352e19c92c cmd/compile: eliminate Gins and Naddr
Preparation for eliminating Prog-related globals.

Passes toolstash-check -all.

Updates #15756

Change-Id: Ia199fcb282cc3a84903a6e92a3ce342c5faba79c
Reviewed-on: https://go-review.googlesource.com/38409
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-22 19:05:52 +00:00
Josh Bleecher Snyder
0dafb7d962 cmd/compile: check for missing function body earlier
Tested by fixedbugs/issue3705.go.

This removes a dependency on lineno
from near the backend.

Change-Id: I228bd0ad7295cf881b9bdeb0df9d18483fb96821
Reviewed-on: https://go-review.googlesource.com/38382
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-21 04:04:46 +00:00
Matthew Dempsky
325904fe6a cmd/compile: port liveness analysis to SSA
Passes toolstash-check -all.

Change-Id: I92c3c25d6c053f971f346f4fa3bbc76419b58183
Reviewed-on: https://go-review.googlesource.com/38087
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-20 22:58:50 +00:00
Josh Bleecher Snyder
dc4434a0c0 cmd/compile: make stkptrsize local
While we're here, also eliminate a few more Curfn uses.

Passes toolstash -cmp. No compiler performance impact.

Updates #15756

Change-Id: Ib8db9e23467bbaf16cc44bf62d604910f733d6b8
Reviewed-on: https://go-review.googlesource.com/38331
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 23:57:27 +00:00
Josh Bleecher Snyder
758b5b3284 cmd/compile: make Stksize local
Passes toolstash -cmp. No compiler performance impact.

Updates #15756

Change-Id: I85b45244453ae28d4da76be4313badddcbf3f5dc
Reviewed-on: https://go-review.googlesource.com/38330
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 23:57:15 +00:00
Josh Bleecher Snyder
da8e939ba9 cmd/compile: thread Curfn through SSA
This is a first step towards eliminating the
Curfn global in the backend.
There's more to do.

Passes toolstash -cmp. No compiler performance impact.

Updates #15756

Change-Id: Ib09f550a001e279a5aeeed0f85698290f890939c
Reviewed-on: https://go-review.googlesource.com/38232
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 23:45:22 +00:00
Matthew Dempsky
09272ae981 cmd/compile/internal/gc: rename Thearch to thearch
Prepared using gorename.

Change-Id: Id55dac9ae5446a8bfeac06e7995b35f4c249eeca
Reviewed-on: https://go-review.googlesource.com/38302
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-03-17 22:10:58 +00:00
Josh Bleecher Snyder
a5e3cac895 cmd/compile: rearrange fields between ssa.Func, ssa.Cache, and ssa.Config
This makes ssa.Func, ssa.Cache, and ssa.Config fulfill
the roles laid out for them in CL 38160.

The only non-trivial change in this CL is how cached
values and blocks get IDs. Prior to this CL, their IDs were
assigned as part of resetting the cache, and only modified
IDs were reset. This required knowing how many values and
blocks were modified, which required a tight coupling between
ssa.Func and ssa.Config. To eliminate that coupling,
we now zero values and blocks during reset,
and assign their IDs when they are used.
Since unused values and blocks have ID == 0,
we can efficiently find the last used value/block,
to avoid zeroing everything.
Bulk zeroing is efficient, but not efficient enough
to obviate the need to avoid zeroing everything every time.
As a happy side-effect, ssa.Func.Free is no longer necessary.

DebugHashMatch and friends now belong in func.go.
They have been left in place for clarity and review.
I will move them in a subsequent CL.

Passes toolstash -cmp. No compiler performance impact.
No change in 'go test cmd/compile/internal/ssa' execution time.

Change-Id: I2eb7af58da067ef6a36e815a6f386cfe8634d098
Reviewed-on: https://go-review.googlesource.com/38167
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-17 05:21:42 +00:00
Josh Bleecher Snyder
0cfb23135c cmd/compile: move hasdefer to Func
Passes toolstash -cmp.

Updates #15756

Change-Id: Ia071dbbd7f2ee0f8433d8c37af4f7b588016244e
Reviewed-on: https://go-review.googlesource.com/38231
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 04:56:11 +00:00
Josh Bleecher Snyder
c03e75e539 cmd/compile: check labels and gotos before building SSA
This CL introduces yet another compiler pass,
which checks for correct control flow constructs
prior to converting from AST to SSA form.

It cannot be integrated with walk, since walk rewrites
switch and select statements on the fly.

To reduce code duplication, this CL also does some
minor refactoring.

With this pass in place, the AST to SSA converter
can now stop generating SSA for any known-dead code.
This minor savings pays for the minor cost of the new pass.

Performance is almost a wash:

name       old time/op     new time/op     delta
Template       206ms ± 4%      205ms ± 4%   ~     (p=0.108 n=43+43)
Unicode       84.0ms ± 4%     84.0ms ± 4%   ~     (p=0.979 n=43+43)
GoTypes        550ms ± 3%      553ms ± 3%   ~     (p=0.065 n=40+41)
Compiler       2.57s ± 4%      2.58s ± 2%   ~     (p=0.103 n=44+41)
SSA            3.94s ± 3%      3.93s ± 2%   ~     (p=0.833 n=44+42)
Flate          126ms ± 6%      125ms ± 4%   ~     (p=0.941 n=43+39)
GoParser       147ms ± 4%      148ms ± 3%   ~     (p=0.164 n=42+39)
Reflect        359ms ± 3%      357ms ± 5%   ~     (p=0.241 n=43+44)
Tar            106ms ± 5%      106ms ± 7%   ~     (p=0.853 n=40+43)
XML            202ms ± 3%      203ms ± 3%   ~     (p=0.488 n=42+41)

name       old user-ns/op  new user-ns/op  delta
Template        240M ± 4%       239M ± 4%   ~     (p=0.844 n=42+43)
Unicode         107M ± 5%       107M ± 4%   ~     (p=0.332 n=40+43)
GoTypes         735M ± 3%       731M ± 4%   ~     (p=0.141 n=43+44)
Compiler       3.51G ± 3%      3.52G ± 3%   ~     (p=0.208 n=42+43)
SSA            5.72G ± 4%      5.72G ± 3%   ~     (p=0.928 n=44+42)
Flate           151M ± 7%       150M ± 8%   ~     (p=0.662 n=44+43)
GoParser        181M ± 5%       181M ± 4%   ~     (p=0.379 n=41+44)
Reflect         447M ± 4%       445M ± 4%   ~     (p=0.344 n=43+43)
Tar             125M ± 7%       124M ± 6%   ~     (p=0.353 n=43+43)
XML             248M ± 4%       250M ± 6%   ~     (p=0.158 n=44+44)

name       old alloc/op    new alloc/op    delta
Template      40.3MB ± 0%     40.2MB ± 0%  -0.27%  (p=0.000 n=10+10)
Unicode       30.3MB ± 0%     30.2MB ± 0%  -0.10%  (p=0.015 n=10+10)
GoTypes        114MB ± 0%      114MB ± 0%  -0.06%  (p=0.000 n=7+9)
Compiler       480MB ± 0%      481MB ± 0%  +0.07%  (p=0.000 n=10+10)
SSA            864MB ± 0%      862MB ± 0%  -0.25%  (p=0.000 n=9+10)
Flate         25.9MB ± 0%     25.9MB ± 0%    ~     (p=0.123 n=10+10)
GoParser      32.1MB ± 0%     32.1MB ± 0%    ~     (p=0.631 n=10+10)
Reflect       79.9MB ± 0%     79.6MB ± 0%  -0.39%  (p=0.000 n=10+9)
Tar           27.1MB ± 0%     27.0MB ± 0%  -0.18%  (p=0.003 n=10+10)
XML           42.6MB ± 0%     42.6MB ± 0%    ~     (p=0.143 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        401k ± 0%       401k ± 1%    ~     (p=0.353 n=10+10)
Unicode         322k ± 0%       322k ± 0%    ~     (p=0.739 n=10+10)
GoTypes        1.18M ± 0%      1.18M ± 0%  +0.25%  (p=0.001 n=7+8)
Compiler       4.51M ± 0%      4.53M ± 0%  +0.37%  (p=0.000 n=10+10)
SSA            7.91M ± 0%      7.93M ± 0%  +0.20%  (p=0.000 n=9+10)
Flate           244k ± 0%       245k ± 0%    ~     (p=0.123 n=10+10)
GoParser        323k ± 1%       324k ± 1%  +0.40%  (p=0.035 n=10+10)
Reflect        1.01M ± 0%      1.02M ± 0%  +0.37%  (p=0.000 n=10+9)
Tar             258k ± 1%       258k ± 1%    ~     (p=0.661 n=10+9)
XML             403k ± 0%       405k ± 0%  +0.47%  (p=0.004 n=10+10)

Updates #15756
Updates #19250

Change-Id: I647bfbb745c35630447eb79dfcaa994b490ce942
Reviewed-on: https://go-review.googlesource.com/38159
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-15 21:44:57 +00:00
Josh Bleecher Snyder
5f5d882f5c cmd/compile: catch bad pragma combination earlier
Bad pragmas should never make it to the backend.
I've confirmed manually that the error position is unchanged.

Updates #15756
Updates #19250

Change-Id: If14f7ce868334f809e337edc270a49680b26f48e
Reviewed-on: https://go-review.googlesource.com/38152
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-14 18:33:26 +00:00
Josh Bleecher Snyder
50520f1543 cmd/compile: use Fatalf for more internal errors
There were a surprising number of places
in the tree that used yyerror for failed internal
consistency checks. Switch them to Fatalf.

Updates #15756
Updates #19250

Change-Id: Ie4278148185795a28ff3c27dacffc211cda5bbdd
Reviewed-on: https://go-review.googlesource.com/38153
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-14 17:58:38 +00:00
Josh Bleecher Snyder
57107f300a cmd/compile: use local fn variable in compile
fn == Curfn in this context. Prefer the local variable.

Passes toolstash -cmp. Updates #15756.

Change-Id: I75b589c682d0c1b524cac2bbf2bba368a6027b06
Reviewed-on: https://go-review.googlesource.com/38151
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-14 17:57:09 +00:00
Cherry Zhang
e471ad9189 cmd/compile: remove duplicated zeroing of outgoing args
Outgoing arg zeroing code is inserted at walk.go:paramstoheap.
Don't do it twice.

Change-Id: I70afac6af9e39b3efce0a6a79d6193428d922708
Reviewed-on: https://go-review.googlesource.com/37863
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-09 21:34:14 +00:00
Matthew Dempsky
527f3518da cmd/compile/internal/gc: skip autotmp vars in gc again
Instead of skipping them based on string matching much later in the
compilation process, skip them up front using the proper API.

Passes toolstash-check.

Change-Id: Ibd4c0448a0701ba0de3235d4689ef300235fa1d9
Reviewed-on: https://go-review.googlesource.com/37930
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-07 19:23:25 +00:00
Matthew Dempsky
68177d9ec0 cmd/internal/obj: move dwarf.Var generation into compiler
Passes toolstash -cmp.

Change-Id: I4bd60f7ebba5457e7b3ece688fee2351bfeeb59a
Reviewed-on: https://go-review.googlesource.com/37874
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2017-03-07 17:32:54 +00:00
Matthew Dempsky
1874d4a883 cmd/internal/obj, cmd/compile: rip off some toolstash bandaids
Change-Id: I402383e893223facae451adbd640113126d5edd9
Reviewed-on: https://go-review.googlesource.com/37873
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-06 23:29:36 +00:00
Matthew Dempsky
9cb2ee0ff2 cmd/internal/obj: move STEXT-only LSym fields into new FuncInfo struct
Shrinks LSym somewhat for non-STEXT LSyms, which are much more common.

While here, switch to tracking Automs in a slice instead of a linked
list. (Previously, this would have made LSyms larger.)

Passes toolstash-check.

Change-Id: I082e50e1d1f1b544c9e06b6e412a186be6a4a2b5
Reviewed-on: https://go-review.googlesource.com/37872
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-03-06 22:17:23 +00:00
Matthew Dempsky
7a98bdf1c2 cmd/internal/obj: remove AUSEFIELD pseudo-op
Instead, cmd/compile can directly emit R_USEFIELD relocations.

Manually verified rsc.io/tmp/fieldtrack still passes.

Change-Id: Ib1fb5ab902ff0ad17ef6a862a9a5692caf7f87d1
Reviewed-on: https://go-review.googlesource.com/37871
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-03-06 22:16:13 +00:00
Aliaksandr Valialkin
ed70f37e73 cmd/compile: pack bool fields in Node, Name, Func and Type structs to bitsets
This reduces compiler memory usage by up to 4% - see compilebench
results below.

name       old time/op     new time/op     delta
Template       245ms ± 4%      241ms ± 2%  -1.88%  (p=0.029 n=10+10)
Unicode        126ms ± 3%      124ms ± 3%    ~     (p=0.105 n=10+10)
GoTypes        805ms ± 2%      813ms ± 3%    ~     (p=0.515 n=8+10)
Compiler       3.95s ± 2%      3.83s ± 1%  -2.96%  (p=0.000 n=9+10)
MakeBash       47.4s ± 4%      46.6s ± 1%  -1.59%  (p=0.028 n=9+10)

name       old user-ns/op  new user-ns/op  delta
Template        324M ± 5%       326M ± 3%    ~     (p=0.935 n=10+10)
Unicode         186M ± 5%       178M ±10%    ~     (p=0.067 n=9+10)
GoTypes        1.08G ± 7%      1.09G ± 4%    ~     (p=0.956 n=10+10)
Compiler       5.34G ± 4%      5.31G ± 1%    ~     (p=0.501 n=10+8)

name       old alloc/op    new alloc/op    delta
Template      41.0MB ± 0%     39.8MB ± 0%  -3.03%  (p=0.000 n=10+10)
Unicode       32.3MB ± 0%     31.0MB ± 0%  -4.13%  (p=0.000 n=10+10)
GoTypes        119MB ± 0%      116MB ± 0%  -2.39%  (p=0.000 n=10+10)
Compiler       499MB ± 0%      487MB ± 0%  -2.48%  (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        380k ± 1%       379k ± 1%    ~     (p=0.436 n=10+10)
Unicode         324k ± 1%       324k ± 0%    ~     (p=0.853 n=10+10)
GoTypes        1.15M ± 0%      1.15M ± 0%    ~     (p=0.481 n=10+10)
Compiler       4.41M ± 0%      4.41M ± 0%  -0.12%  (p=0.007 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       623k ± 0%       623k ± 0%    ~     (all equal)
CmdGoSize      6.64M ± 0%      6.64M ± 0%    ~     (all equal)

name       old data-bytes  new data-bytes  delta
HelloSize      5.81k ± 0%      5.81k ± 0%    ~     (all equal)
CmdGoSize       238k ± 0%       238k ± 0%    ~     (all equal)

name       old bss-bytes   new bss-bytes   delta
HelloSize       134k ± 0%       134k ± 0%    ~     (all equal)
CmdGoSize       152k ± 0%       152k ± 0%    ~     (all equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       967k ± 0%       967k ± 0%    ~     (all equal)
CmdGoSize      10.2M ± 0%      10.2M ± 0%    ~     (all equal)

Change-Id: I1f40af738254892bd6c8ba2eb43390b175753d52
Reviewed-on: https://go-review.googlesource.com/37445
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-03 21:06:03 +00:00
Heschi Kreinick
ac7761e1a4 cmd/compile, cmd/asm: remove Link.Plists
Link.Plists never contained more than one Plist, and sometimes none.
Passing around the Plist being worked on is straightforward and makes
the data flow easier to follow.

Change-Id: I79cb30cb2bd3d319fdbb1dfa5d35b27fcb748e5c
Reviewed-on: https://go-review.googlesource.com/37169
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-01 00:29:23 +00:00
Matthew Dempsky
02de5ed748 cmd/internal/obj: add AddrName type and cleanup AddrType values
Passes toolstash -cmp.

Change-Id: Ida3eda9bd9d79a34c1c3f18cb41aea9392698076
Reviewed-on: https://go-review.googlesource.com/36950
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-13 21:56:17 +00:00
Keith Randall
5a75d6a08e cmd/compile: optimize non-empty-interface type conversions
When doing i.(T) for non-empty-interface i and concrete type T,
there's no need to read the type out of the itab. Just compare the
itab to the itab we expect for that interface/type pair.

Also optimize type switches by putting the type hash of the
concrete type in the itab. That way we don't need to load the
type pointer out of the itab.

Update #18492

Change-Id: I49e280a21e5687e771db5b8a56b685291ac168ce
Reviewed-on: https://go-review.googlesource.com/34810
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
2017-02-13 18:16:31 +00:00
Austin Clements
450472989b cmd/compile: disallow combining nosplit and systemstack
go:systemstack works by tweaking the stack check prologue to check
against a different bound, while go:nosplit removes the stack check
prologue entirely. Hence, they can't be used together. Make the build
fail if they are.

Change-Id: I2d180c4b1d31ff49ec193291ecdd42921d253359
Reviewed-on: https://go-review.googlesource.com/36710
Run-TryBot: Austin Clements <austin@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-02-09 22:27:17 +00:00
Matthew Dempsky
7bad00366b cmd/internal/obj: remove ATYPE
In cmd/compile, we can directly construct obj.Auto to represent local
variables and attach them to the function's obj.LSym.

In preparation for being able to emit more precise DWARF info based on
other compiler available information (e.g., lexical scoping).

Change-Id: I9c4225ec59306bec42552838493022e0e9d70228
Reviewed-on: https://go-review.googlesource.com/36420
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-07 22:38:18 +00:00
Matthew Dempsky
6a29440dcc cmd/compile/internal/gc: remove more backend Sym uses
Removes all external uses of Linksym and Pkglookup, which are the only
two exported functions that return Syms.

Also add Duffcopy and Duffzero since they're used often enough across
SSA backends.

Passes toolstash -cmp.

Change-Id: I8d3fd048ad5cd676fc46378f09a917569ffc9b2c
Reviewed-on: https://go-review.googlesource.com/36418
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-06 23:25:44 +00:00
Matthew Dempsky
5f374ea8fb cmd/compile/internal/gc: stop exporting *gc.Sym-typed globals
The arch-specific SSA backends now no longer use gc.Sym either.

Passes toolstash -cmp.

Change-Id: Ic13b934b92a1b89b4b79c6c4796ab0a137608163
Reviewed-on: https://go-review.googlesource.com/36416
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-06 22:45:49 +00:00
Robert Griesemer
472c792e0a [dev.inline] cmd/internal/src: introduce compact source position representation
XPos is a compact (8 instead of 16 bytes on a 64bit machine) source
position representation. There is a 1:1 correspondence between each
XPos and each regular Pos, translated via a global table.

In some sense this brings back the LineHist, though positions can
track line and column information; there is a O(1) translation
between the representations (no binary search), and the translation
is factored out.

The size increase with the prior change is brought down again and
the compiler speed is in line with the master repo (measured on
the same "quiet" machine as for prior change):

name       old time/op     new time/op     delta
Template       256ms ± 1%      262ms ± 2%    ~             (p=0.063 n=5+4)
Unicode        132ms ± 1%      135ms ± 2%    ~             (p=0.063 n=5+4)
GoTypes        891ms ± 1%      871ms ± 1%  -2.28%          (p=0.016 n=5+4)
Compiler       3.84s ± 2%      3.89s ± 2%    ~             (p=0.413 n=5+4)
MakeBash       47.1s ± 1%      46.2s ± 2%    ~             (p=0.095 n=5+5)

name       old user-ns/op  new user-ns/op  delta
Template        309M ± 1%       314M ± 2%    ~             (p=0.111 n=5+4)
Unicode         165M ± 1%       172M ± 9%    ~             (p=0.151 n=5+5)
GoTypes        1.14G ± 2%      1.12G ± 1%    ~             (p=0.063 n=5+4)
Compiler       5.00G ± 1%      4.96G ± 1%    ~             (p=0.286 n=5+4)

Change-Id: Icc570cc60ab014d8d9af6976f1f961ab8828cc47
Reviewed-on: https://go-review.googlesource.com/34506
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-01-09 22:43:22 +00:00
Robert Griesemer
24597c080b [dev.inline] cmd/compile: introduce cmd/internal/src.Pos type for line numbers
This is a step toward chosing a different position representation.
By introducing an explicit type, it will be easier to make the
transition step-wise while ensuring everything keeps running.

This has been reviewed via https://go-review.googlesource.com/#/c/34025/.

Change-Id: Ibceddcd62d8f346321ac3250e3940e9c436ed684
Reviewed-on: https://go-review.googlesource.com/34132
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Lazar <lazard@golang.org>
2016-12-08 21:26:25 +00:00
Keith Randall
c96e94e69d cmd/compile: generate frame pointers for otherwise frameless functions
func f() {
    g()
}

We mistakenly don't add a frame pointer for f.  This means f
isn't seen when walking the frame pointer linked list.  That
matters for kernel-gathered profiles, and is an impediment for
issues like #16638.

To fix, allocate a stack frame even for otherwise frameless functions
like f.  It is a bit tricky because we need to avoid some runtime
internals that really, really don't want one.

No test at the moment, as only kernel CPU profiles would catch it.
Tests will come with the implementation of #16638.

Fixes #18103

Change-Id: I411206cc9de4c8fdd265bee2e4fa61d161ad1847
Reviewed-on: https://go-review.googlesource.com/33754
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2016-12-01 19:25:17 +00:00
David Chase
9f5673d930 cmd/compile: ensure necessary types appear in .debug_info
Autotmp filtering was too aggressive and excluded types
necessary to make debuggers work properly.  Restore the
"late filter" in dwarf.go based on names to exclude autotmps,
and remove the "early filter" in pgen.go based on how the
name was introduced.  However, the updated naming scheme
with a dot prefix is retained to prevent accidental clashes
with legal Go identifier names.

Includes test (grouped with runtime gdb tests),
verified to fail without the fix.

Updates #17644.
Fixes #17830.

Change-Id: I7ec3f7230083889660236e5f6bc77ba5fe434e93
Reviewed-on: https://go-review.googlesource.com/33233
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-11-16 22:05:19 +00:00
Vladimir Stefanovic
7f033933ce cmd/compile/internal/gc: add support for GOARCH=mips{,le}
Change-Id: Ida4cd647525abce3441bfcb9fdee059344fe717f
Reviewed-on: https://go-review.googlesource.com/31477
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2016-11-04 20:15:23 +00:00
Keith Randall
688995d1e9 cmd/compile: do more type conversion inline
The code to do the conversion is smaller than the
call to the runtime.
The 1-result asserts need to call panic if they fail, but that
code is out of line.

The only conversions left in the runtime are those which
might allocate and those which might need to generate an itab.

Given the following types:
  type E interface{}
  type I interface { foo() }
  type I2 iterface { foo(); bar() }
  type Big [10]int
  func (b Big) foo() { ... }

This CL inlines the following conversions:

was assertE2T
  var e E = ...
  b := i.(Big)
was assertE2T2
  var e E = ...
  b, ok := i.(Big)
was assertI2T
  var i I = ...
  b := i.(Big)
was assertI2T2
  var i I = ...
  b, ok := i.(Big)
was assertI2E
  var i I = ...
  e := i.(E)
was assertI2E2
  var i I = ...
  e, ok := i.(E)

These are the remaining runtime calls:

convT2E:
  var b Big = ...
  var e E = b
convT2I:
  var b Big = ...
  var i I = b
convI2I:
  var i2 I2 = ...
  var i I = i2
assertE2I:
  var e E = ...
  i := e.(I)
assertE2I2:
  var e E = ...
  i, ok := e.(I)
assertI2I:
  var i I = ...
  i2 := i.(I2)
assertI2I2:
  var i I = ...
  i2, ok := i.(I2)

Fixes #17405
Fixes #8422

Change-Id: Ida2367bf8ce3cd2c6bb599a1814f1d275afabe21
Reviewed-on: https://go-review.googlesource.com/32313
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-11-02 21:33:03 +00:00
David Chase
9c066bab64 cmd/compile: mark temps with new AutoTemp flag, and use it.
This is an extension of
https://go-review.googlesource.com/c/31662/
to mark all the temporaries, not just the ssa-generated ones.

Before-and-after ls -l `go tool -n compile` shows a 3%
reduction in size (or rather, a prior 3% inflation for
failing to filter temps out properly.)

Replaced name-dependent "is it a temp?" tests with calls to
*Node.IsAutoTmp(), which depends on AutoTemp.  Also replace
calls to istemp(n) with n.IsAutoTmp(), to reduce duplication
and clean up function name space.  Generated temporaries
now come with a "." prefix to avoid (apparently harmless)
clashes with legal Go variable names.

Fixes #17644.
Fixes #17240.

Change-Id: If1417f29c79a7275d7303ddf859b51472890fd43
Reviewed-on: https://go-review.googlesource.com/32255
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-10-31 19:38:50 +00:00
Than McIntosh
d80e8de54e cmd/compile: avoid truncating fieldname var locations
Don't include package path when creating LSyms for auto and param
variables during Prog generation, and update the DWARF emit routine
accordingly (remove the code that chops off package path from names in
DWARF var location expressions). Implementation suggested by mdempsky@.

The intent of this change is to have saner location expressions in cases
where the variable corresponds to a structure field. For example, the
SSA compiler's "decompose" phase can take a slice value and break it
apart into three scalar variables corresponding to the fields (slice "X"
gets split into "X.len", "X.cap", "X.ptr"). In such cases we want the
name in the location expression to omit the package path but preserve
the original variable name (e.g. "X").

Fixes #16338

Change-Id: Ibc444e7f3454b70fc500a33f0397e669d127daa1
Reviewed-on: https://go-review.googlesource.com/31819
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-10-26 21:14:46 +00:00