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32335 Commits

Author SHA1 Message Date
Josh Bleecher Snyder
63c1aff60b cmd/internal/obj: eagerly initialize assemblers
CL 38662 changed the x86 assembler to be eagerly
initialized, for a concurrent backend.

This CL puts in place a proper mechanism for doing so,
and switches all architectures to use it.

Passes toolstash-check -all.

Updates #15756

Change-Id: Id2aa527d3a8259c95797d63a2f0d1123e3ca2a1c
Reviewed-on: https://go-review.googlesource.com/39917
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-07 16:57:03 +00:00
Chris Broadfoot
817c1023b0 doc: document go1.8.1
Change-Id: I9282c1907204ec5c6363de84faec222a38300c9f
Reviewed-on: https://go-review.googlesource.com/39919
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-07 16:45:08 +00:00
Josh Bleecher Snyder
6297f06cbd cmd/compile: fix build by updating to new types package
CL 38776 was not updated to use the new types package.

Fixes build.

Change-Id: Ie80ff4837cac95bd628e0405a937045171d56e0c
Reviewed-on: https://go-review.googlesource.com/39918
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-07 16:02:57 +00:00
Josh Bleecher Snyder
9eddc3a356 cmd/vet/all: add countBytes exemption to amd64 whitelist
Fixes vetall build broken by CL 38693.

Change-Id: I5c98f2164e0c7bb43f022c363b3b7c0650c4bcbe
Reviewed-on: https://go-review.googlesource.com/39916
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2017-04-07 15:49:22 +00:00
Ilya Tocar
e4a500ce14 cmd/compile/internal/gc: improve comparison with constant strings
Currently we expand comparison with small constant strings into len check
and a sequence of byte comparisons. Generate 16/32/64-bit comparisons,
instead of bytewise on 386 and amd64. Also increase limits on what is
considered small constant string.
Shaves ~30kb (0.5%) from go executable.

This also updates test/prove.go to keep test case valid.

Change-Id: I99ae8871a1d00c96363c6d03d0b890782fa7e1d9
Reviewed-on: https://go-review.googlesource.com/38776
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-07 15:40:25 +00:00
Josselin Costanzi
d206af1e6c strings: optimize Count for amd64
Move optimized Count implementation from bytes to runtime. Use in
both bytes and strings packages.
Add CountByte benchmark to strings.

Strings benchmarks:
name                       old time/op    new time/op    delta
CountHard1-4                 226µs ± 1%      226µs ± 2%      ~     (p=0.247 n=10+10)
CountHard2-4                 316µs ± 1%      315µs ± 0%      ~     (p=0.133 n=9+10)
CountHard3-4                 919µs ± 1%      920µs ± 1%      ~     (p=0.968 n=10+9)
CountTorture-4              15.4µs ± 1%     15.7µs ± 1%    +2.47%  (p=0.000 n=10+9)
CountTortureOverlapping-4   9.60ms ± 0%     9.65ms ± 1%      ~     (p=0.247 n=10+10)
CountByte/10-4              26.3ns ± 1%     10.9ns ± 1%   -58.71%  (p=0.000 n=9+9)
CountByte/32-4              42.7ns ± 0%     14.2ns ± 0%   -66.64%  (p=0.000 n=10+10)
CountByte/4096-4            3.07µs ± 0%     0.31µs ± 2%   -89.99%  (p=0.000 n=9+10)
CountByte/4194304-4         3.48ms ± 1%     0.34ms ± 1%   -90.09%  (p=0.000 n=10+9)
CountByte/67108864-4        55.6ms ± 1%      7.0ms ± 0%   -87.49%  (p=0.000 n=9+8)

name                      old speed      new speed       delta
CountByte/10-4             380MB/s ± 1%    919MB/s ± 1%  +142.21%  (p=0.000 n=9+9)
CountByte/32-4             750MB/s ± 0%   2247MB/s ± 0%  +199.62%  (p=0.000 n=10+10)
CountByte/4096-4          1.33GB/s ± 0%  13.32GB/s ± 2%  +898.13%  (p=0.000 n=9+10)
CountByte/4194304-4       1.21GB/s ± 1%  12.17GB/s ± 1%  +908.87%  (p=0.000 n=10+9)
CountByte/67108864-4      1.21GB/s ± 1%   9.65GB/s ± 0%  +699.29%  (p=0.000 n=9+8)

Fixes #19411

Change-Id: I8d2d409f0fa6df6d03b60790aa86e540b4a4e3b0
Reviewed-on: https://go-review.googlesource.com/38693
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-07 14:25:13 +00:00
Tamir Duberstein
03d1aa6024 syscall: mark WSAECONNABORTED, WSAECONNRESET as temporary network errors
Windows was missed in https://golang.org/cl/141600043.

Fixes #6163 (again).

Change-Id: I09076be80fb6b2148d3e5618461ebaa79f27d5b3
Reviewed-on: https://go-review.googlesource.com/39490
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-07 04:46:42 +00:00
Robert Griesemer
e8475c94b8 cmd/compile/internal/types: shorten struct type names
They are in the types package, no need to mention the Type suffix.

Change-Id: Ie4fe1e3c1793514145e33f9df373d715f63e1aad
Reviewed-on: https://go-review.googlesource.com/39911
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 03:44:05 +00:00
Robert Griesemer
5c850cc207 cmd/compile: move sizeof tests for types structs to package types
Change-Id: I04cd4dd0ed55b88247a056b429fc496539cd0985
Reviewed-on: https://go-review.googlesource.com/39910
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 03:43:34 +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
Matthew Dempsky
19bd145d07 Revert "cmd/compile: make typenamesym do less work"
This reverts commit 91433eb577.

Reason for revert: broke deterministic build.

Fixes #19872.

Change-Id: Ia1a0fc651b818bdf69454df43bd189689c0348a0
Reviewed-on: https://go-review.googlesource.com/39871
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-04-07 00:47:56 +00:00
Matthew Dempsky
385c13cf18 cmd/compile/internal/gc: remove a bunch of uses of iterField
Passes toolstash-check -all.

Change-Id: I9fb91dd78dff149b5e1e1329d00855fd41f12523
Reviewed-on: https://go-review.googlesource.com/39796
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-06 23:08:54 +00:00
Matthew Dempsky
a680a85ea7 cmd/compile/internal/gc: simplify export info
Followup to previous typenod CL. Changes export data format, but only
the compiler-specific section, so no version bump.

Change-Id: I0c21737141f3d257366b29b2a9211bc7217c39ee
Reviewed-on: https://go-review.googlesource.com/39797
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-06 22:56:15 +00:00
Matthew Dempsky
2e1b42a814 cmd/compile/internal/gc: remove a bunch of uses of typenod
Passes toolstash-check -all.

Change-Id: Ic9eb0c52bedac185ab86cc62207f199d93700344
Reviewed-on: https://go-review.googlesource.com/39795
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-04-06 22:47:08 +00:00
Josh Bleecher Snyder
25fc842f17 cmd/compile: remove forceObjFileStability
The textual import/export format is ancient history.

Change-Id: Iebe90bfd9bd3074eb191186d86e5f4286ce3b1f3
Reviewed-on: https://go-review.googlesource.com/39850
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-06 22:25:19 +00:00
Josh Bleecher Snyder
91433eb577 cmd/compile: make typenamesym do less work
typenamesym is called from three places:
typename, ngotype, and Type.Symbol.
Only in typename do we actually need a Node.
ngotype and Type.Symbol require only a Sym.
And writing the newly created Node to
Sym.Def is unsafe in a concurrent backend.
Rather than use a mutex protect to Sym.Def,
make typenamesym not touch Sym.Def.

The assignment to Sym.Def was serving a second purpose,
namely to prevent duplicate entries on signatlist.
Preserve that functionality by switching signatlist to a map.
This in turn requires that we sort signatlist
when exporting it, to preserve reproducibility.

We'd like to use Type.cmp for sorting,
but that causes infinite recursion at the moment;
see #19869.

For now, use Type.LongString as the sort key,
which is a complete description of the type.
Type.LongString is relatively expensive,
but we calculate it only once per type,
and signatlist is generally fairly small,
so the performance impact is minimal.

Updates #15756

name       old alloc/op    new alloc/op    delta
Template      39.4MB ± 0%     39.4MB ± 0%    ~     (p=0.222 n=5+5)
Unicode       29.8MB ± 0%     29.8MB ± 0%    ~     (p=0.151 n=5+5)
GoTypes        113MB ± 0%      113MB ± 0%    ~     (p=0.095 n=5+5)
SSA           1.25GB ± 0%     1.25GB ± 0%  +0.04%  (p=0.008 n=5+5)
Flate         25.3MB ± 0%     25.4MB ± 0%    ~     (p=0.056 n=5+5)
GoParser      31.8MB ± 0%     31.8MB ± 0%    ~     (p=0.310 n=5+5)
Reflect       78.3MB ± 0%     78.3MB ± 0%    ~     (p=0.690 n=5+5)
Tar           26.7MB ± 0%     26.7MB ± 0%    ~     (p=0.548 n=5+5)
XML           42.2MB ± 0%     42.2MB ± 0%    ~     (p=0.222 n=5+5)

name       old allocs/op   new allocs/op   delta
Template        387k ± 0%       388k ± 0%    ~     (p=0.056 n=5+5)
Unicode         320k ± 0%       321k ± 0%  +0.32%  (p=0.032 n=5+5)
GoTypes        1.14M ± 0%      1.15M ± 0%    ~     (p=0.095 n=5+5)
SSA            9.70M ± 0%      9.72M ± 0%  +0.18%  (p=0.008 n=5+5)
Flate           234k ± 0%       235k ± 0%  +0.60%  (p=0.008 n=5+5)
GoParser        317k ± 0%       317k ± 0%    ~     (p=1.000 n=5+5)
Reflect         982k ± 0%       983k ± 0%    ~     (p=0.841 n=5+5)
Tar             252k ± 1%       252k ± 0%    ~     (p=0.310 n=5+5)
XML             393k ± 0%       392k ± 0%    ~     (p=0.548 n=5+5)

Change-Id: I53a3b95d19cf1a7b7511a94fba896706addf84fb
Reviewed-on: https://go-review.googlesource.com/39710
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-06 21:51:38 +00:00
Kale Blankenship
b599c1fe0d net/http: add tests for http2 Server WriteTimeout enforcement per stream
Updates #18437

Change-Id: Iaa8a35d18eca8be24763dd151ad9e324ecbf7f7b
Reviewed-on: https://go-review.googlesource.com/34726
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-06 19:52:20 +00:00
Josh Bleecher Snyder
99683483d6 cmd/internal/obj: unify creation of numeric literal syms
This is a straightforward refactoring,
to reduce the scope of upcoming changes.

The symbol size and AttrLocal=true was not
set universally, but it appears not to matter,
since toolstash -cmp is happy.

Passes toolstash-check -all.

Change-Id: I7f8392f939592d3a1bc6f61dec992f5661f42fca
Reviewed-on: https://go-review.googlesource.com/39791
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 19:01:50 +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
Daniel Martí
2c1888bf48 net/http: fix ineffective break in etag scanning
In particular, this lead to the code accepting invalid ETags as long as
they finished with a '"'.

Also remove a duplicate test case.

Change-Id: Id59db3ebc4e4969562f891faef29111e77ee0e65
Reviewed-on: https://go-review.googlesource.com/39690
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-06 18:44:29 +00:00
Cherry Zhang
0bae9b083b cmd/internal/obj/arm64: fix encoding of AND MBCON
When a constant is both MOVCON (can fit into a MOV instruction)
and BITCON (can fit into a logical instruction), the assembler
chooses to use the MOVCON encoding, which is actually longer for
logical instructions. We add MBCON rules explicitly to make sure
it uses the BITCON encoding.

Updates #19857.

Change-Id: Ib9881be363cbc491ac2a0792b36b87e74eff34a8
Reviewed-on: https://go-review.googlesource.com/39652
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-06 17:59:39 +00:00
Cherry Zhang
257b01f8f4 cmd/compile: use ANDconst to mask out leading/trailing bits on ARM64
For an AND that masks out leading or trailing bits, generic rules
rewrite it to a pair of shifts. On ARM64, the mask actually can
fit into an AND instruction. So we rewrite it back to AND.

Fixes #19857.

Change-Id: I479d7320ae4f29bb3f0056d5979bde4478063a8f
Reviewed-on: https://go-review.googlesource.com/39651
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-06 17:59:32 +00:00
Jeff Wendling
168eb9cf33 cmd/dist: disable plugin test on linux-arm with GOARM=5
Plugin support is patchy at the moment, so disable the test for
now until the test can be fixed. This way, we can get builders
for ARMv5 running for the rest of the code.

Updates #19674

Change-Id: I08aa211c08a85688656afe2ad2e680a2a6e5dfac
Reviewed-on: https://go-review.googlesource.com/39716
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-06 17:39:20 +00:00
Daniel Martí
4e7724b2db runtime: remove unused parameter from bestFitTreap
This code was added recently, and it doesn't seem like the parameter
will be useful in the near future.

Change-Id: I5d64dadb6820c159b588262ab90df2461b5fdf04
Reviewed-on: https://go-review.googlesource.com/39692
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2017-04-06 17:20:43 +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
Robert Griesemer
52d8d7b93a cmd/compile: remove InterMethod type - not used anywhere
Change-Id: I2c402d9491b373316775b515ce389555e58acb1a
Reviewed-on: https://go-review.googlesource.com/39636
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-06 03:54:03 +00:00
Josh Bleecher Snyder
5b59b32c97 cmd/compile: teach assemblers to accept a Prog allocator
The existing bulk Prog allocator is not concurrency-safe.
To allow for concurrency-safe bulk allocation of Progs,
I want to move Prog allocation and caching upstream,
to the clients of cmd/internal/obj.

This is a preliminary enabling refactoring.
After this CL, instead of calling Ctxt.NewProg
throughout the assemblers, we thread through
a newprog function that returns a new Prog.

That function is set up to be Ctxt.NewProg,
so there are no real changes in this CL;
this CL only establishes the plumbing.

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

Updates #15756

name        old time/op     new time/op     delta
Template        213ms ± 3%      214ms ± 4%    ~     (p=0.574 n=49+47)
Unicode        90.1ms ± 5%     89.9ms ± 4%    ~     (p=0.417 n=50+49)
GoTypes         585ms ± 4%      584ms ± 3%    ~     (p=0.466 n=49+49)
SSA             6.50s ± 3%      6.52s ± 2%    ~     (p=0.251 n=49+49)
Flate           128ms ± 4%      128ms ± 4%    ~     (p=0.673 n=49+50)
GoParser        152ms ± 3%      152ms ± 3%    ~     (p=0.810 n=48+49)
Reflect         372ms ± 4%      372ms ± 5%    ~     (p=0.778 n=49+50)
Tar             113ms ± 5%      111ms ± 4%  -0.98%  (p=0.016 n=50+49)
XML             208ms ± 3%      208ms ± 2%    ~     (p=0.483 n=47+49)
[Geo mean]      285ms           285ms       -0.17%

name        old user-ns/op  new user-ns/op  delta
Template         253M ± 8%       254M ± 9%    ~     (p=0.899 n=50+50)
Unicode          106M ± 9%       106M ±11%    ~     (p=0.642 n=50+50)
GoTypes          736M ± 4%       740M ± 4%    ~     (p=0.121 n=50+49)
SSA             8.82G ± 3%      8.88G ± 2%  +0.65%  (p=0.006 n=49+48)
Flate            147M ± 4%       147M ± 5%    ~     (p=0.844 n=47+48)
GoParser         179M ± 4%       178M ± 6%    ~     (p=0.785 n=50+50)
Reflect          443M ± 6%       441M ± 5%    ~     (p=0.850 n=48+47)
Tar              126M ± 5%       126M ± 5%    ~     (p=0.734 n=50+50)
XML              244M ± 5%       244M ± 5%    ~     (p=0.594 n=49+50)
[Geo mean]       341M            341M       +0.11%

Change-Id: Ice962f61eb3a524c2db00a166cb582c22caa7d68
Reviewed-on: https://go-review.googlesource.com/39633
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 02:07:21 +00:00
Josh Bleecher Snyder
7e068895c3 cmd/compile: add mutex profiling support
Updates #15756
Updates #19822

Change-Id: I98b17dcbbfd80e7e164b0523185382175fe2d89b
Reviewed-on: https://go-review.googlesource.com/39554
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-05 22:10:54 +00:00
Austin Clements
9741f0275c runtime: initialize more fields of stack spans
Stack spans don't internally use many of the fields of the mspan,
which means things like the size class and element size get left over
from whatever last used the mspan. This can lead to confusing crashes
and debugging.

Zero these fields or initialize them to something reasonable. This
also lets us simplify some code that currently has to distinguish
between heap and stack spans.

Change-Id: I9bd114e76c147bb32de497045b932f8bf1988bbf
Reviewed-on: https://go-review.googlesource.com/38573
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2017-04-05 19:17:41 +00:00
Russ Cox
92cf05daf3 test: deflake locklinear again
Fixes #19276.

Change-Id: I64f8f80331d09956b6698c0b004ed7f7d70857fc
Reviewed-on: https://go-review.googlesource.com/39591
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-05 18:46:31 +00:00
Russ Cox
10991fd5af cmd/go: add test for test -race -i behavior
This was fixed in CL 37598 but the test was (rightly) dropped
because it modified $GOROOT. Here's a variant that does not.

For #19151.

Change-Id: Iccdbbf9ae8ac4c252e52f4f8ff996963573c4682
Reviewed-on: https://go-review.googlesource.com/39592
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-05 18:46:16 +00:00
Austin Clements
ecb7b63820 runtime: fix gcpacertrace printing of sweep ratio
Commit 44ed88a5a7 moved printing of the "sweep done" gcpacertrace
message so that it is printed when the final sweeper finishes.
However, by this point some other thread has often already observed
that there are no more spans to sweep and zeroed sweepPagesPerByte.

Avoid printing a 0 sweep ratio in the trace when this race happens by
getting the value of the sweep ratio upon entry to sweepone and
printing that.

Change-Id: Iac0c48ae899e12f193267cdfb012c921f8b71c85
Reviewed-on: https://go-review.googlesource.com/39492
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2017-04-05 18:24:52 +00:00
Josh Bleecher Snyder
92cffa1391 cmd/internal/obj: remove dead func Copyp
Change-Id: Iaeb7bcbcdbc46c0e0e40b0aa070c706e0ca53013
Reviewed-on: https://go-review.googlesource.com/39555
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-05 15:18:14 +00:00
Lynn Boger
ed2f913b4c syscall: update comments for x/sys migration
The comments in this package state that users should be
migrating code that uses the syscall package to its
corresponding package in x/sys. However, the syscall.Signal
and syscall.Errno types and the syscall.SysProcAttr struct is
not defined in the x/sys package and still need to be referenced
from within syscall.  This adds a change to the comments to
clarify that the migration will need to continue to use some
references to syscall for now.

Fixes #19560

Change-Id: I8abb96b93bea90070ce461da16dc7bcf7b4b29c1
Reviewed-on: https://go-review.googlesource.com/39450
Reviewed-by: Rob Pike <r@golang.org>
2017-04-05 14:22:15 +00:00
Russ Cox
a7b51cfb47 testing/quick: use Uint64 instead of Int63
Followup to CL 39152.

Change-Id: I9bfed0c6071ea3d3a43294a6c4a50edc131368cf
Reviewed-on: https://go-review.googlesource.com/39313
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-05 14:03:03 +00:00
Lorenzo Masini
476f55fd8a cmd/objdump: print Go code alongside assembly
Added -S flag to print go source file line above corresponding disassembly:

$ go tool objdump -S -s main.main fmthello
TEXT main.main(SB) /home/rugginoso/Documents/src/go/src/cmd/objdump/testdata/fmthello.go
func main() {
  0x47d450		64488b0c25f8ffffff	FS MOVQ FS:0xfffffff8, CX
  0x47d459		483b6110		CMPQ 0x10(CX), SP
  0x47d45d		7631			JBE 0x47d490
  0x47d45f		4883ec18		SUBQ $0x18, SP
  0x47d463		48896c2410		MOVQ BP, 0x10(SP)
  0x47d468		488d6c2410		LEAQ 0x10(SP), BP
	Println("hello, world")
  0x47d46d		488d0563b00200		LEAQ 0x2b063(IP), AX
  0x47d474		48890424		MOVQ AX, 0(SP)
  0x47d478		48c74424080c000000	MOVQ $0xc, 0x8(SP)
  0x47d481		e81a000000		CALL main.Println(SB)
}
  0x47d486		488b6c2410		MOVQ 0x10(SP), BP
  0x47d48b		4883c418		ADDQ $0x18, SP
  0x47d48f		c3			RET
func main() {
  0x47d490		e8ebf1fcff		CALL runtime.morestack_noctxt(SB)
  0x47d495		ebb9			JMP main.main(SB)

Execution time:

$ time go tool objdump testdata/fmthello > /dev/null
real	0m0.430s
user	0m0.440s
sys	0m0.000s

$ time go tool objdump -S testdata/fmthello > /dev/null
real	0m0.471s
user	0m0.476s
sys	0m0.012s

Fixes #18245

Change-Id: I9b2f8338f9ee443c1352efd270d3ba85e3dd9b78
Reviewed-on: https://go-review.googlesource.com/37953
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-05 06:20:40 +00:00
Alex Brainman
acc1f47299 path/filepath: add test to walk symlink
For #17540.

Change-Id: Ie01f39797526934fa553f4279cbde6c7cbf14154
Reviewed-on: https://go-review.googlesource.com/36854
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-05 02:31:45 +00:00
Josh Bleecher Snyder
4c1622082e cmd/compile: don't catch panics during rewrite
This is a holdover from the days when we did not
have full SSA coverage and compiled things optimistically,
and catching the panic obscures useful information.

Change-Id: I196790cb6b97419d92b318a2dfa7f1e1097cefb7
Reviewed-on: https://go-review.googlesource.com/39534
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-04 23:37:17 +00:00
Josh Bleecher Snyder
fc327a14c4 cmd/compile: remove order canonicalization rules from mips
CL 38801 introduced automatic commutative rule generation.
Manual order canonicalization rules thus lead to infinite loops.

Fixes #19842

Change-Id: I877c476152f4d207fdc67bc6f3018265aa9bc5ac
Reviewed-on: https://go-review.googlesource.com/39533
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-04 23:17:23 +00:00
Filip Gruszczyński
6c5a819a5e reflect: add MakeMapWithSize for creating maps with size hint
Providing size hint when creating a map allows avoiding re-allocating
underlying data structure if we know how many elements are going to
be inserted. This can be used for example during decoding maps in
gob.

Fixes #19599

Change-Id: I108035fec29391215d2261a73eaed1310b46bab1
Reviewed-on: https://go-review.googlesource.com/38335
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-04 20:01:43 +00:00
Rob Pike
be5a201e2a text/template: fix handling of empty blocks
This was a subtle bug introduced in the previous release's fix for
issue 16156.

The definition of empty template was broken, causing the answer
to depend on the order of templates in the map.

Fixes #16156 (for real).
Fixes #19294.
Fixes #19204.

Change-Id: I1cd915c94534cad3116d83bd158cbc28700510b9
Reviewed-on: https://go-review.googlesource.com/38420
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-04 15:46:02 +00:00
Martin Möhrmann
bebfd4ba41 strings: speed up Fields
- use a string lookup to detect if a single byte is a space character
- determine the exact number of fields for ASCII and
  a possibly underestimated number of fields for non ASCII strings
  by doing a separate byte for byte scan of the input string
  before collecting the fields in an extra pass
- provide a fast path for ASCII only strings when collecting the fields
- avoid utf8.DecodeRuneInString and unicode.IsSpace for ASCII characters

Used golang.org/cl/33108 from Joe Tsai as starting point.

name                      old time/op    new time/op     delta
Fields/ASCII/16              284ns ± 1%      116ns ± 2%   -59.30%  (p=0.000 n=9+10)
Fields/ASCII/256            3.81µs ± 1%     0.80µs ± 1%   -79.10%  (p=0.000 n=10+10)
Fields/ASCII/4096           61.4µs ± 1%     12.3µs ± 1%   -79.96%  (p=0.000 n=10+9)
Fields/ASCII/65536           982µs ± 1%      235µs ± 0%   -76.04%  (p=0.000 n=10+9)
Fields/ASCII/1048576        16.7ms ± 2%      5.4ms ± 1%   -67.52%  (p=0.000 n=10+10)
Fields/Mixed/16              314ns ± 1%      168ns ± 1%   -46.33%  (p=0.000 n=9+10)
Fields/Mixed/256            3.92µs ± 1%     1.17µs ± 1%   -70.19%  (p=0.000 n=10+10)
Fields/Mixed/4096           69.1µs ± 1%     19.0µs ± 1%   -72.53%  (p=0.000 n=10+10)
Fields/Mixed/65536          1.12ms ± 1%     0.39ms ± 0%   -65.37%  (p=0.000 n=10+9)
Fields/Mixed/1048576        19.0ms ± 2%      7.3ms ± 4%   -61.75%  (p=0.000 n=10+9)

name                      old speed      new speed       delta
Fields/ASCII/16           56.3MB/s ± 1%  138.1MB/s ± 2%  +145.31%  (p=0.000 n=9+10)
Fields/ASCII/256          67.1MB/s ± 1%  321.0MB/s ± 1%  +378.26%  (p=0.000 n=10+10)
Fields/ASCII/4096         66.7MB/s ± 1%  333.0MB/s ± 1%  +398.97%  (p=0.000 n=10+9)
Fields/ASCII/65536        66.7MB/s ± 1%  278.4MB/s ± 0%  +317.39%  (p=0.000 n=10+9)
Fields/ASCII/1048576      62.7MB/s ± 2%  192.9MB/s ± 1%  +207.82%  (p=0.000 n=10+10)
Fields/Mixed/16           51.0MB/s ± 2%   94.9MB/s ± 1%   +85.87%  (p=0.000 n=10+10)
Fields/Mixed/256          65.4MB/s ± 1%  219.2MB/s ± 1%  +235.33%  (p=0.000 n=10+10)
Fields/Mixed/4096         59.3MB/s ± 1%  215.7MB/s ± 1%  +263.98%  (p=0.000 n=10+10)
Fields/Mixed/65536        58.6MB/s ± 1%  169.1MB/s ± 0%  +188.73%  (p=0.000 n=10+9)
Fields/Mixed/1048576      55.1MB/s ± 2%  144.0MB/s ± 4%  +161.44%  (p=0.000 n=10+9)

Updates #19789
Updates #17856

Change-Id: If2ce1479542702e9cd65a82a462ba55ac8eb3876
Reviewed-on: https://go-review.googlesource.com/37959
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2017-04-04 06:26:11 +00:00
Keith Randall
5cadc91b3c cmd/compile: intrinsics for math/bits.OnesCount
Popcount instructions on amd64 are not guaranteed to be
present, so we must guard their call.  Rewrite rules can't
generate control flow at the moment, so the intrinsifier
needs to generate that code.

name           old time/op  new time/op  delta
OnesCount-8    2.47ns ± 5%  1.04ns ± 2%  -57.70%  (p=0.000 n=10+10)
OnesCount16-8  1.05ns ± 1%  0.78ns ± 0%  -25.56%    (p=0.000 n=9+8)
OnesCount32-8  1.63ns ± 5%  1.04ns ± 2%  -35.96%  (p=0.000 n=10+10)
OnesCount64-8  2.45ns ± 0%  1.04ns ± 1%  -57.55%   (p=0.000 n=6+10)

Update #18616

Change-Id: I4aff2cc9aa93787898d7b22055fe272a7cf95673
Reviewed-on: https://go-review.googlesource.com/38320
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-04-04 02:40:11 +00:00
Eric Lagergren
59f6549d1c bytes, strings: declare variables inside loop they're used in
The recently updated Count functions declare variables before
special-cased returns.

Change-Id: I8f726118336b7b0ff72117d12adc48b6e37e60ea
Reviewed-on: https://go-review.googlesource.com/39357
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-03 23:30:36 +00:00
Josh Bleecher Snyder
42426ed411 cmd/compile: Fatal instead of panic in large bvbulkalloc
This provides better diagnostics when it occurs.

Updates #19751

Change-Id: I87db54c22e1345891b418c1741dc76ac5fb8ed00
Reviewed-on: https://go-review.googlesource.com/39358
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 23:28:29 +00:00
Eric Lagergren
094498c9a1 all: fix minor misspellings
Change-Id: I1f1cfb161640eb8756fb1a283892d06b30b7a8fa
Reviewed-on: https://go-review.googlesource.com/39356
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-03 23:19:07 +00:00
Josh Bleecher Snyder
50688fcb6e cmd/compile: unroll small static maps
When a map is small, it's not worth putting
the contents in an array and then looping over the array.
Just generate code instead.

This makes smaller binaries.
It might also be better for cache lines.

It also can avoids adding control flow in the middle
of the init function, which can be very large.
Eliminating this source of extra blocks
makes phi insertion easier for temp-heavy init functions.
This reduces the time required for compiler to
panic while compiling the code in #19751
from 15 minutes to 45 seconds.

The cutoff of 25 was chosen fairly unscientifically
by looking at the size of cmd/go.

Cutoff of   0: 10689604
Cutoff of   5: 10683572
Cutoff of  15: 10682324
Cutoff of  25: 10681700
Cutoff of  50: 10685476
Cutoff of 100: 10689412

There are probably more sophisticated mechanisms available.
For example, the smaller the key/value sizes, the better
generated code will be vs a table.
Nevertheless this is simple and seems like a good start.

Updates #19751

name       old time/op     new time/op     delta
Template       204ms ± 6%      202ms ± 5%  -0.78%  (p=0.027 n=47+45)
Unicode       84.8ms ± 6%     85.2ms ± 7%    ~     (p=0.146 n=46+45)
GoTypes        551ms ± 2%      556ms ± 3%  +0.76%  (p=0.004 n=43+45)
SSA            3.93s ± 3%      3.95s ± 4%    ~     (p=0.179 n=50+49)
Flate          123ms ± 4%      123ms ± 5%    ~     (p=0.201 n=47+49)
GoParser       145ms ± 3%      145ms ± 4%    ~     (p=0.937 n=50+50)
Reflect        356ms ± 3%      354ms ± 5%  -0.44%  (p=0.048 n=46+50)
Tar            107ms ± 6%      106ms ± 6%    ~     (p=0.188 n=50+49)
XML            201ms ± 4%      200ms ± 4%    ~     (p=0.085 n=50+49)

name       old user-ns/op  new user-ns/op  delta
Template        252M ± 9%       250M ± 7%    ~     (p=0.206 n=49+47)
Unicode         106M ± 7%       106M ± 9%    ~     (p=0.331 n=47+46)
GoTypes         724M ± 5%       729M ± 5%    ~     (p=0.160 n=47+49)
SSA            5.64G ± 2%      5.62G ± 4%    ~     (p=0.148 n=47+50)
Flate           147M ± 6%       147M ± 5%    ~     (p=0.466 n=50+49)
GoParser        179M ± 5%       179M ± 6%    ~     (p=0.584 n=50+49)
Reflect         448M ± 6%       441M ± 8%  -1.39%  (p=0.027 n=50+49)
Tar             124M ± 6%       123M ± 5%    ~     (p=0.221 n=50+47)
XML             244M ± 5%       243M ± 4%    ~     (p=0.275 n=49+49)

name       old alloc/op    new alloc/op    delta
Template      39.9MB ± 0%     39.4MB ± 0%  -1.28%  (p=0.008 n=5+5)
Unicode       29.8MB ± 0%     29.8MB ± 0%    ~     (p=0.310 n=5+5)
GoTypes        113MB ± 0%      113MB ± 0%    ~     (p=0.421 n=5+5)
SSA            854MB ± 0%      854MB ± 0%    ~     (p=0.151 n=5+5)
Flate         25.3MB ± 0%     25.3MB ± 0%    ~     (p=1.000 n=5+5)
GoParser      31.8MB ± 0%     31.8MB ± 0%    ~     (p=0.222 n=5+5)
Reflect       78.2MB ± 0%     78.2MB ± 0%    ~     (p=1.000 n=5+5)
Tar           26.7MB ± 0%     26.7MB ± 0%    ~     (p=0.841 n=5+5)
XML           42.3MB ± 0%     42.3MB ± 0%  -0.15%  (p=0.008 n=5+5)

name       old allocs/op   new allocs/op   delta
Template        390k ± 1%       386k ± 1%  -1.05%  (p=0.016 n=5+5)
Unicode         319k ± 0%       320k ± 0%    ~     (p=0.310 n=5+5)
GoTypes        1.14M ± 0%      1.14M ± 0%    ~     (p=0.421 n=5+5)
SSA            7.60M ± 0%      7.59M ± 0%    ~     (p=0.310 n=5+5)
Flate           234k ± 0%       235k ± 1%    ~     (p=1.000 n=5+5)
GoParser        315k ± 1%       317k ± 0%    ~     (p=0.151 n=5+5)
Reflect         978k ± 0%       978k ± 0%    ~     (p=0.841 n=5+5)
Tar             251k ± 1%       251k ± 1%    ~     (p=0.690 n=5+5)
XML             394k ± 0%       392k ± 0%    ~     (p=0.056 n=5+5)


Change-Id: Ic53a18627082abe075a1cbc33330ce015e50850a
Reviewed-on: https://go-review.googlesource.com/39354
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-03 22:41:06 +00:00
Keith Randall
53f8a6aeb0 cmd/compile: automatically handle commuting ops in rewrite rules
Note that this is a redo of an undo of the original buggy CL 38666.

We have lots of rewrite rules that vary only in the fact that
we have 2 versions for the 2 different orderings of various
commuting ops. For example:

(ADDL x (MOVLconst [c])) -> (ADDLconst [c] x)
(ADDL (MOVLconst [c]) x) -> (ADDLconst [c] x)

It can get unwieldly quickly, especially when there is more than
one commuting op in a rule.

Our existing "fix" for this problem is to have rules that
canonicalize the operations first. For example:

(Eq64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Eq64 (Const64 <t> [c]) x)

Subsequent rules can then assume if there is a constant arg to Eq64,
it will be the first one. This fix kinda works, but it is fragile and
only works when we remember to include the required extra rules.

The fundamental problem is that the rule matcher doesn't
know anything about commuting ops. This CL fixes that fact.

We already have information about which ops commute. (The register
allocator takes advantage of commutivity.)  The rule generator now
automatically generates multiple rules for a single source rule when
there are commutative ops in the rule. We can now drop all of our
almost-duplicate source-level rules and the canonicalization rules.

I have some CLs in progress that will be a lot less verbose when
the rule generator handles commutivity for me.

I had to reorganize the load-combining rules a bit. The 8-way OR rules
generated 128 different reorderings, which was causing the generator
to put too much code in the rewrite*.go files (the big ones were going
from 25K lines to 132K lines). Instead I reorganized the rules to
combine pairs of loads at a time. The generated rule files are now
actually a bit (5%) smaller.

Make.bash times are ~unchanged.

Compiler benchmarks are not observably different. Probably because
we don't spend much compiler time in rule matching anyway.

I've also done a pass over all of our ops adding commutative markings
for ops which hadn't had them previously.

Fixes #18292

Change-Id: Ic1c0e43fbf579539f459971625f69690c9ab8805
Reviewed-on: https://go-review.googlesource.com/38801
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-03 22:03:43 +00:00
Keith Randall
63a72fd447 cmd/compile: strength-reduce floating point
x*2 -> x+x
x/c, c power of 2 -> x*(1/c)

Fixes #19827

Change-Id: I74c9f0b5b49b2ed26c0990314c7d1d5f9631b6f1
Reviewed-on: https://go-review.googlesource.com/39295
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-03 21:27:03 +00:00
Josh Bleecher Snyder
095a62c349 cmd/compile: refactor maplit
Instead of walking the list of nodes twice,
once to find static entries to add to an array
and once to find dynamic entries to generate code for,
do the split once up front, into two slices.
Then process each slice individually.
This makes the code easier to read
and more importantly, easier to modify.

While we're here, add a TODO to avoid
using temporaries for mapassign_fast calls.
It's not an important TODO;
the generated code would be basically identical.
It would just avoid a minor amount of
pointless SSA optimization work.

Passes toolstash-check.
No measureable compiler performance impact.

Updates #19751

Change-Id: I84a8f2c22f9025c718ef34639059d7bd02a3c406
Reviewed-on: https://go-review.googlesource.com/39351
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-03 20:10:17 +00:00