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  1. 17 May, 2017 7 commits
    • Carl Henrik Lunde's avatar
      runtime/pprof: deflake TestGoroutineCounts · 2dc27839
      Carl Henrik Lunde authored 
      TestGoroutineCounts was flaky when running on a system under load.
This happened on three builds the last couple of days.

Fix this by running this test with a single operating system thread, so
we do not depend on the operating system scheduler.  50 000 tests ran
without failure with the new version, the old version failed 0.5% of the
time.

Fixes #15156.

Change-Id: I1e5a18d0fef4f72cc9a56e376822b2849cdb0f8b
Reviewed-on: https://go-review.googlesource.com/43590Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: 's avatarAustin Clements <austin@google.com>
      2dc27839
    • Josh Bleecher Snyder's avatar
      cmd/compile: fuse from end to beginning · b3e577b9
      Josh Bleecher Snyder authored 
      fuseBlockPlain was accidentally quadratic.
If you had plain blocks b1 -> b2 -> b3 -> b4,
each containing single values v1, v2, v3, and v4 respectively,
fuseBlockPlain would move v1 from b1 to b2 to b3 to b4,
then v2 from b2 to b3 to b4, etc.

There are two obvious fixes.

* Look for runs of blocks in fuseBlockPlain
  and handle them in a single go.
* Fuse from end to beginning; any given value in a run
  of blocks to fuse then moves only once.

The latter is much simpler, so that's what this CL does.

Somewhat surprisingly, this change does not pass toolstash-check.

The resulting set of blocks is the same,
and the values in them are the same,
but the order of values in them differ,
and that order of values (while arbitrary)
is enough to change the compiler's output.
This may be due to #20178; deadstore is the next pass after fuse.

Adding basic sorting to the beginning of deadstore
is enough to make this CL pass toolstash-check:

	for _, b := range f.Blocks {
		obj.SortSlice(b.Values, func(i, j int) bool { return b.Values[i].ID < b.Values[j].ID })
	}

Happily, this CL appears to result in better code on average,
if only by accident. It cuts 4k off of cmd/go; go1 benchmarks
are noisy as always but don't regress (numbers below).

No impact on the standard compilebench benchmarks.
For the code in #13554, this speeds up compilation dramatically:

name  old time/op       new time/op       delta
Pkg         53.1s ± 2%        12.8s ± 3%  -75.92%  (p=0.008 n=5+5)

name  old user-time/op  new user-time/op  delta
Pkg         55.0s ± 2%        14.9s ± 3%  -73.00%  (p=0.008 n=5+5)

name  old alloc/op      new alloc/op      delta
Pkg        2.04GB ± 0%       2.04GB ± 0%   +0.18%  (p=0.008 n=5+5)

name  old allocs/op     new allocs/op     delta
Pkg         6.21M ± 0%        6.21M ± 0%     ~     (p=0.222 n=5+5)

name  old object-bytes  new object-bytes  delta
Pkg         28.4M ± 0%        28.4M ± 0%   +0.00%  (p=0.008 n=5+5)

name  old export-bytes  new export-bytes  delta
Pkg           208 ± 0%          208 ± 0%     ~     (all equal)


Updates #13554


go1 benchmarks:

name                     old time/op    new time/op    delta
BinaryTree17-8              2.29s ± 2%     2.26s ± 2%  -1.43%  (p=0.000 n=48+50)
Fannkuch11-8                2.74s ± 2%     2.79s ± 2%  +1.63%  (p=0.000 n=50+49)
FmtFprintfEmpty-8          36.6ns ± 3%    34.6ns ± 4%  -5.29%  (p=0.000 n=49+50)
FmtFprintfString-8         58.3ns ± 3%    59.1ns ± 3%  +1.35%  (p=0.000 n=50+49)
FmtFprintfInt-8            62.4ns ± 2%    63.2ns ± 3%  +1.19%  (p=0.000 n=49+49)
FmtFprintfIntInt-8         95.1ns ± 2%    96.7ns ± 3%  +1.61%  (p=0.000 n=49+50)
FmtFprintfPrefixedInt-8     118ns ± 3%     113ns ± 2%  -4.00%  (p=0.000 n=50+49)
FmtFprintfFloat-8           191ns ± 2%     192ns ± 2%  +0.40%  (p=0.034 n=50+50)
FmtManyArgs-8               419ns ± 2%     420ns ± 2%    ~     (p=0.228 n=49+49)
GobDecode-8                5.26ms ± 3%    5.19ms ± 2%  -1.33%  (p=0.000 n=50+49)
GobEncode-8                4.12ms ± 2%    4.15ms ± 3%  +0.68%  (p=0.007 n=49+50)
Gzip-8                      198ms ± 2%     197ms ± 2%  -0.50%  (p=0.018 n=48+48)
Gunzip-8                   31.9ms ± 3%    31.8ms ± 3%  -0.47%  (p=0.024 n=50+50)
HTTPClientServer-8         64.4µs ± 0%    64.0µs ± 0%  -0.55%  (p=0.000 n=43+46)
JSONEncode-8               10.6ms ± 2%    10.6ms ± 3%    ~     (p=0.543 n=49+49)
JSONDecode-8               43.3ms ± 3%    43.1ms ± 2%    ~     (p=0.079 n=50+50)
Mandelbrot200-8            3.70ms ± 2%    3.70ms ± 2%    ~     (p=0.553 n=47+50)
GoParse-8                  2.70ms ± 2%    2.71ms ± 3%    ~     (p=0.843 n=49+50)
RegexpMatchEasy0_32-8      70.5ns ± 4%    70.4ns ± 4%    ~     (p=0.867 n=48+50)
RegexpMatchEasy0_1K-8       162ns ± 3%     162ns ± 2%    ~     (p=0.739 n=48+48)
RegexpMatchEasy1_32-8      66.1ns ± 5%    66.2ns ± 4%    ~     (p=0.970 n=50+50)
RegexpMatchEasy1_1K-8       297ns ± 7%     296ns ± 7%    ~     (p=0.406 n=50+50)
RegexpMatchMedium_32-8      105ns ± 5%     105ns ± 5%    ~     (p=0.702 n=50+50)
RegexpMatchMedium_1K-8     32.3µs ± 4%    32.2µs ± 3%    ~     (p=0.614 n=49+49)
RegexpMatchHard_32-8       1.75µs ±18%    1.74µs ±12%    ~     (p=0.738 n=50+48)
RegexpMatchHard_1K-8       52.2µs ±14%    51.3µs ±13%    ~     (p=0.230 n=50+50)
Revcomp-8                   366ms ± 3%     367ms ± 3%    ~     (p=0.745 n=49+49)
Template-8                 48.5ms ± 4%    48.5ms ± 4%    ~     (p=0.824 n=50+48)
TimeParse-8                 263ns ± 2%     256ns ± 2%  -2.98%  (p=0.000 n=48+49)
TimeFormat-8                265ns ± 3%     262ns ± 3%  -1.35%  (p=0.000 n=48+49)
[Geo mean]                 41.1µs         40.9µs       -0.48%


Change-Id: Ib35fa15b54282abb39c077d150beee27f610891a
Reviewed-on: https://go-review.googlesource.com/43570
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarDavid Chase <drchase@google.com>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      b3e577b9
    • Josh Bleecher Snyder's avatar
      cmd/compile: seed rand with time when race enabled · ff262913
      Josh Bleecher Snyder authored 
      When the race detector is enabled,
the compiler randomizes the order in which functions are compiled,
in an attempt to shake out bugs.
But we never re-seed the rand source, so every execution is identical.
Fix that to get more coverage.

Change-Id: If5cdde03ef4f1bab5f45e07f03fb6614945481d7
Reviewed-on: https://go-review.googlesource.com/43572
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      ff262913
    • Hiroshi Ioka's avatar
      cmd/cgo: support large unsigned macros · 7555a45d
      Hiroshi Ioka authored 
      Currently, cgo converts integer macros into int64 if it's possible.
As a result, some macros which satisfy

math.MaxInt64 < x <= math.MaxUint64

will lose their original values.

This CL introduces the new probe to check signs,
so we can handle signed ints and unsigned ints separately.

Fixes #20369

Change-Id: I002ba452a82514b3a87440960473676f842cc9ee
Reviewed-on: https://go-review.googlesource.com/43476Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      7555a45d
    • Ian Lance Taylor's avatar
      cmd/go: don't fail on missing runtime/internal/sys/zversion.go · c20e5453
      Ian Lance Taylor authored 
      The generated file runtime/internal/sys/zversion.go is deleted by
`go tool cmd dist clean` as part of running clean.bash. Don't treat
a missing file as a reason to stop running the go tool; just treat
is as meaning that runtime/internal/sys is stale.

No test because I don't particularly want to clobber $GOROOT.

Fixes #20385.

Change-Id: I5251a99542cc93c33f627f133d7118df56e18af1
Reviewed-on: https://go-review.googlesource.com/43559
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      c20e5453
    • Ian Lance Taylor's avatar
      cmd/go: fix TestExecutableGOROOT if GOROOT is a symlink · acc56909
      Ian Lance Taylor authored 
      Fixes #20365.

Change-Id: If1a4866193cff3bc836d8bbf18b6a1f5deb9808d
Reviewed-on: https://go-review.googlesource.com/43550
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: 's avatarAlessandro Arzilli <alessandro.arzilli@gmail.com>
      acc56909
    • Ian Lance Taylor's avatar
      os: fix handling of ErrShortWrite in (*File).Write · 0fd7de49
      Ian Lance Taylor authored 
      Restore the handling of io.ErrShortWrite in (*File).Write:
if we write less than the requested amount, and there is no error from
the syscall, then return io.ErrShortWrite.

I can't figure out how to write a test for this. It would require a
non-pollable file (not a pipe) on a device that is almost but not
quite entirely full. The original code (https://golang.org/cl/36800043,
committed as part of https://golang.org/cl/36930044) does not have a test.

Fixes #20386.

Change-Id: Ied7b411e621e1eaf49f864f8db90069f276256f5
Reviewed-on: https://go-review.googlesource.com/43558
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      0fd7de49
  3. 16 May, 2017 8 commits
    • Sean Chittenden's avatar
      runtime: mmap(2) on Solaris & Illumos can return EAGAIN. · 13cdd814
      Sean Chittenden authored 
      In low memory situations mmap(2) on Illumos[2] can return EAGAIN when it
is unable to reserve the necessary space for the requested mapping.  Go
was not previously handling this correctly for Illumos and would fail to
recognize it was in a low-memory situation, the result being the program
would terminate with a panic instead of running the GC.

Fixes: #14930

[1]: https://www.illumos.org/man/2/mmap

Change-Id: I889cc0547e23f9d6c56e4fdd7bcbd0e15403873a
Reviewed-on: https://go-review.googlesource.com/43461Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      13cdd814
    • Cherry Zhang's avatar
      runtime, syscall: in Plan 9 ARM asm, replace "SWI 0" with "SWI $0" · 3b263e43
      Cherry Zhang authored 
      On other systems we use "SWI $n". Change Plan 9 files to be
consistent. Generated binary is unchanged.

Fixes #20378.

Change-Id: Ia2a722061da2450c7b30cb707ed4f172fafecf74
Reviewed-on: https://go-review.googlesource.com/43533Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      3b263e43
    • Adam Langley's avatar
      crypto/tls: pass argument to serverInit rather than using a field in Config. · 46f4bfb2
      Adam Langley authored 
      Updates #20164.

Change-Id: Ib900095e7885f25cd779750674a712c770603ca8
Reviewed-on: https://go-review.googlesource.com/42137Reviewed-by: 's avatarRuss Cox <rsc@golang.org>
Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      46f4bfb2
    • Cherry Zhang's avatar
      cmd/internal/obj/mips: add support of LLV, SCV, NOOP instructions · b53acd89
      Cherry Zhang authored 
      LLV and SCV are 64-bit load-linked and store-conditional. They
were used in runtime as #define WORD. Change them to normal
instruction form.

NOOP is hardware no-op. It was written as WORD $0. Make a name
for it for better disassembly output.

Fixes #12561.
Fixes #18238.

Change-Id: I82c667ce756fa83ef37b034b641e8c4366335e83
Reviewed-on: https://go-review.googlesource.com/40297Reviewed-by: 's avatarMinux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      b53acd89
    • Mark Harrison's avatar
      path: add examples · 84a51432
      Mark Harrison authored 
      This change adds several examples, with emphasis on special or edge
cases such as a directory parameter consisting of an empty string.

Change-Id: Ib4ac3d0f6d503493eeed0c4fda7c12acf782e9e2
Reviewed-on: https://go-review.googlesource.com/43010Reviewed-by: 's avatarSteve Francia <spf@golang.org>
Run-TryBot: Jaana Burcu Dogan <jbd@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      84a51432
    • Josh Bleecher Snyder's avatar
      cmd/compile: eliminate some bounds checks from generated rewrite rules · 5548f7d5
      Josh Bleecher Snyder authored 
      Noticed while looking at #20356.

Cuts 160k (1%) off of the cmd/compile binary.

Change-Id: If2397bc6971d6be9be6975048adecb0b5efa6d66
Reviewed-on: https://go-review.googlesource.com/43501
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      5548f7d5
    • Josh Bleecher Snyder's avatar
      cmd/compile: lay out exit blocks last · 4b0d74f8
      Josh Bleecher Snyder authored 
      In Go 1.8.x, panics are generally scheduled at the very end of functions.
That property was lost in Go 1.9; this CL restores it.

This helps with the Fannkuch benchmark:

name          old time/op  new time/op  delta
Fannkuch11-8   2.74s ± 2%   2.55s ± 2%  -7.03%  (p=0.000 n=20+20)

This increases the fannkuch function size from 801 bytes to 831 bytes,
but that is still smaller than Go 1.8.1 at 844 bytes.

It generally increases binary size a tiny amount.
Negligible compiler performance impact.

For the code in #14758:

name   old time/op    new time/op    delta
Foo-8     326ns ± 3%     312ns ± 3%  -4.32%  (p=0.000 n=28+30)
Bar-8     560ns ± 2%     565ns ± 2%  +0.96%  (p=0.002 n=30+27)

Updates #18977

name        old alloc/op      new alloc/op      delta
Template         38.8MB ± 0%       38.8MB ± 0%    ~     (p=0.690 n=5+5)
Unicode          28.7MB ± 0%       28.7MB ± 0%    ~     (p=0.841 n=5+5)
GoTypes           109MB ± 0%        109MB ± 0%    ~     (p=0.690 n=5+5)
Compiler          457MB ± 0%        457MB ± 0%    ~     (p=0.841 n=5+5)
SSA              1.10GB ± 0%       1.10GB ± 0%  +0.03%  (p=0.032 n=5+5)
Flate            24.4MB ± 0%       24.5MB ± 0%    ~     (p=0.690 n=5+5)
GoParser         30.9MB ± 0%       30.9MB ± 0%    ~     (p=0.421 n=5+5)
Reflect          73.3MB ± 0%       73.3MB ± 0%    ~     (p=1.000 n=5+5)
Tar              25.5MB ± 0%       25.5MB ± 0%    ~     (p=0.095 n=5+5)
XML              40.8MB ± 0%       40.9MB ± 0%    ~     (p=0.056 n=5+5)
[Geo mean]       71.6MB            71.6MB       +0.01%

name        old allocs/op     new allocs/op     delta
Template           395k ± 0%         394k ± 1%    ~     (p=1.000 n=5+5)
Unicode            344k ± 0%         344k ± 0%    ~     (p=0.690 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=0.421 n=5+5)
Compiler          4.41M ± 0%        4.41M ± 0%    ~     (p=0.841 n=5+5)
SSA               9.79M ± 0%        9.79M ± 0%    ~     (p=0.310 n=5+5)
Flate              237k ± 0%         237k ± 0%    ~     (p=0.841 n=5+5)
GoParser           321k ± 0%         321k ± 1%    ~     (p=0.421 n=5+5)
Reflect            956k ± 0%         956k ± 0%    ~     (p=1.000 n=5+5)
Tar                251k ± 1%         252k ± 0%    ~     (p=0.095 n=5+5)
XML                399k ± 0%         400k ± 0%    ~     (p=0.222 n=5+5)
[Geo mean]         741k              741k       +0.03%

name        old object-bytes  new object-bytes  delta
Template           386k ± 0%         386k ± 0%  +0.05%  (p=0.008 n=5+5)
Unicode            202k ± 0%         202k ± 0%  +0.02%  (p=0.008 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%  +0.07%  (p=0.008 n=5+5)
Compiler          3.91M ± 0%        3.91M ± 0%  +0.05%  (p=0.008 n=5+5)
SSA               7.86M ± 0%        7.87M ± 0%  +0.07%  (p=0.008 n=5+5)
Flate              227k ± 0%         227k ± 0%  +0.10%  (p=0.008 n=5+5)
GoParser           283k ± 0%         283k ± 0%  +0.04%  (p=0.008 n=5+5)
Reflect            950k ± 0%         951k ± 0%  +0.04%  (p=0.008 n=5+5)
Tar                187k ± 0%         187k ± 0%  -0.03%  (p=0.008 n=5+5)
XML                406k ± 0%         406k ± 0%  +0.04%  (p=0.008 n=5+5)
[Geo mean]         647k              647k       +0.04%

Change-Id: I2015aa26338b90cf41e47f89564e336dc02608df
Reviewed-on: https://go-review.googlesource.com/43293Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      4b0d74f8
    • Wei Xiao's avatar
      cmd/internal/objabi: fix the bug of shrinking SymType down to a uint8 · b2363ee9
      Wei Xiao authored 
      Previous CL (cmd/internal/objabi: shrink SymType down to a uint8) shrinks
SymType down to a uint8 but forgot making according change in goobj.

Fixes #20296
Also add a test to catch such Goobj format inconsistency bug

Change-Id: Ib43dd7122cfcacf611a643814e95f8c5a924941f
Reviewed-on: https://go-review.googlesource.com/42971
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarMichael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      b2363ee9
  5. 15 May, 2017 8 commits
  7. 14 May, 2017 3 commits
    • Robert Griesemer's avatar
      text/scanner: clarify documentation on Pos and Position · fca6ad45
      Robert Griesemer authored 
      For #20292. (See discussion in that issue.)

Change-Id: I44cd69394fc47a01776905ec34305ba524c89883
Reviewed-on: https://go-review.googlesource.com/43452Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      fca6ad45
    • Josh Bleecher Snyder's avatar
      cmd/compile: tweak ssa.html colors · cfae61b6
      Josh Bleecher Snyder authored 
      Make yellow the last highlight color rather than the first.
Yellow is also the color that Chrome uses to highlight
search results, which can be confusing.
Also, when Night Shift is on on macOS,
yellow highlighting is completely invisible.
I suppose should be sleeping instead.

Also, remove a completed TODO.

Change-Id: I0eb4439272fad9ccb5fe8e2cf409fdd5dc15b26e
Reviewed-on: https://go-review.googlesource.com/43463
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      cfae61b6
    • Josh Bleecher Snyder's avatar
      cmd/compile: don't update outer variables after capturevars is complete · 61336b78
      Josh Bleecher Snyder authored 
      When compiling concurrently, we walk all functions before compiling
any of them. Walking functions can cause variables to switch from
being non-addrtaken to addrtaken, e.g. to prepare for a runtime call.
Typechecking propagates addrtaken-ness of closure variables to
their outer variables, so that capturevars can decide whether to
pass the variable's value or a pointer to it.

When all functions are compiled immediately, as long as the containing
function is compiled prior to the closure, this propagation has no effect.
When compilation is deferred, though, in rare cases, this results in 
a change in the addrtaken-ness of a variable in the outer function,
which in turn changes the compiler's output.
(This is rare because in a great many cases, a temporary has been
introduced, insulating the outer variable from modification.)
But concurrent compilation must generate identical results.

To fix this, track whether capturevars has run.
If it has, there is no need to update outer variables
when closure variables change.
Capturevars always runs before any functions are walked or compiled.

The remainder of the changes in this CL are to support the test.
In particular, -d=compilelater forces the compiler to walk all
functions before compiling any of them, despite being non-concurrent.
This is useful because -live is fundamentally incompatible with
concurrent compilation, but we want -c=1 to have no behavior changes.

Fixes #20250

Change-Id: I89bcb54268a41e8588af1ac8cc37fbef856a90c2
Reviewed-on: https://go-review.googlesource.com/42853
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarRobert Griesemer <gri@golang.org>
      61336b78
  9. 13 May, 2017 3 commits
  11. 12 May, 2017 7 commits
  13. 11 May, 2017 4 commits
    • Keith Randall's avatar
      cmd/compile: fix store chain in schedule pass · 978af9c2
      Keith Randall authored 
      Tuple ops are weird. They are essentially a pair of ops,
one which consumes a mem and one which generates a mem (the Select1).
The schedule pass didn't handle these quite right.

Fix the scheduler to include both parts of the paired op in
the store chain. That makes sure that loads are correctly ordered
with respect to the first of the pair.

Add a check for the ssacheck builder, that there is only one
live store at a time. I thought we already had such a check, but
apparently not...

Fixes #20335

Change-Id: I59eb3446a329100af38d22820b1ca2190ca46a78
Reviewed-on: https://go-review.googlesource.com/43294
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      978af9c2
    • Josh Bleecher Snyder's avatar
      cmd/compile: restore panic deduplication · e5bb5e39
      Josh Bleecher Snyder authored 
      The switch to detailed position information broke
the removal of duplicate panics on the same line.
Restore it.

Neutral compiler performance impact:

name        old alloc/op      new alloc/op      delta
Template         38.8MB ± 0%       38.8MB ± 0%    ~     (p=0.690 n=5+5)
Unicode          28.7MB ± 0%       28.7MB ± 0%  +0.13%  (p=0.032 n=5+5)
GoTypes           109MB ± 0%        109MB ± 0%    ~     (p=1.000 n=5+5)
Compiler          457MB ± 0%        457MB ± 0%    ~     (p=0.151 n=5+5)
SSA              1.09GB ± 0%       1.10GB ± 0%  +0.17%  (p=0.008 n=5+5)
Flate            24.6MB ± 0%       24.5MB ± 0%  -0.35%  (p=0.008 n=5+5)
GoParser         30.9MB ± 0%       31.0MB ± 0%    ~     (p=0.421 n=5+5)
Reflect          73.4MB ± 0%       73.4MB ± 0%    ~     (p=0.056 n=5+5)
Tar              25.6MB ± 0%       25.5MB ± 0%  -0.61%  (p=0.008 n=5+5)
XML              40.9MB ± 0%       40.9MB ± 0%    ~     (p=0.841 n=5+5)
[Geo mean]       71.6MB            71.6MB       -0.07%

name        old allocs/op     new allocs/op     delta
Template           394k ± 0%         395k ± 1%    ~     (p=0.151 n=5+5)
Unicode            343k ± 0%         344k ± 0%  +0.38%  (p=0.032 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=1.000 n=5+5)
Compiler          4.41M ± 0%        4.42M ± 0%    ~     (p=0.151 n=5+5)
SSA               9.79M ± 0%        9.79M ± 0%    ~     (p=0.690 n=5+5)
Flate              238k ± 1%         238k ± 0%    ~     (p=0.151 n=5+5)
GoParser           321k ± 0%         321k ± 1%    ~     (p=0.548 n=5+5)
Reflect            958k ± 0%         957k ± 0%    ~     (p=0.841 n=5+5)
Tar                252k ± 0%         252k ± 1%    ~     (p=0.151 n=5+5)
XML                401k ± 0%         400k ± 0%    ~     (p=1.000 n=5+5)
[Geo mean]         741k              742k       +0.08%


Reduces object files a little bit:

name        old object-bytes  new object-bytes  delta
Template           386k ± 0%         386k ± 0%  -0.04%  (p=0.008 n=5+5)
Unicode            202k ± 0%         202k ± 0%    ~     (all equal)
GoTypes           1.16M ± 0%        1.16M ± 0%  -0.04%  (p=0.008 n=5+5)
Compiler          3.91M ± 0%        3.91M ± 0%  -0.08%  (p=0.008 n=5+5)
SSA               7.91M ± 0%        7.91M ± 0%  -0.04%  (p=0.008 n=5+5)
Flate              228k ± 0%         227k ± 0%  -0.28%  (p=0.008 n=5+5)
GoParser           283k ± 0%         283k ± 0%  -0.01%  (p=0.008 n=5+5)
Reflect            952k ± 0%         951k ± 0%  -0.03%  (p=0.008 n=5+5)
Tar                188k ± 0%         187k ± 0%  -0.09%  (p=0.008 n=5+5)
XML                406k ± 0%         406k ± 0%  -0.04%  (p=0.008 n=5+5)
[Geo mean]         648k              648k       -0.06%


This was discovered in the context for the Fannkuch benchmark.
It shrinks the number of panicindex calls in that function
from 13 back to 9, their 1.8.1 level.

It shrinks the function text a bit, from 829 to 801 bytes.
It slows down execution a little, presumably due to alignment (?).

name          old time/op  new time/op  delta
Fannkuch11-8   2.68s ± 2%   2.74s ± 1%  +2.09%  (p=0.000 n=19+20)

After this CL, 1.8.1 and tip are identical:

name          old time/op  new time/op  delta
Fannkuch11-8   2.74s ± 2%   2.74s ± 1%   ~     (p=0.301 n=20+20)

Fixes #20332

Change-Id: I2aeacc3e8cf2ac1ff10f36c572a27856f4f8f7c9
Reviewed-on: https://go-review.googlesource.com/43291
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      e5bb5e39
    • Josh Bleecher Snyder's avatar
      cmd/compile: don't use statictmps for SSA-able composite literals · ee69c217
      Josh Bleecher Snyder authored 
      The writebarrier test has to change.
Now that T23 composite literals are passed to the backend,
they get SSA'd, so writes to their fields are treated separately,
so the relevant part of the first write to t23 is now a dead store.
Preserve the intent of the test by splitting it up into two functions.

Reduces code size a bit:

name        old object-bytes  new object-bytes  delta
Template           386k ± 0%         386k ± 0%    ~     (all equal)
Unicode            202k ± 0%         202k ± 0%    ~     (all equal)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (all equal)
Compiler          3.92M ± 0%        3.91M ± 0%  -0.19%  (p=0.008 n=5+5)
SSA               7.91M ± 0%        7.91M ± 0%    ~     (all equal)
Flate              228k ± 0%         228k ± 0%  -0.05%  (p=0.008 n=5+5)
GoParser           283k ± 0%         283k ± 0%    ~     (all equal)
Reflect            952k ± 0%         952k ± 0%  -0.06%  (p=0.008 n=5+5)
Tar                188k ± 0%         188k ± 0%  -0.09%  (p=0.008 n=5+5)
XML                406k ± 0%         406k ± 0%  -0.02%  (p=0.008 n=5+5)
[Geo mean]         649k              648k       -0.04%

Fixes #18872

Change-Id: Ifeed0f71f13849732999aa731cc2bf40c0f0e32a
Reviewed-on: https://go-review.googlesource.com/43154
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarDavid Chase <drchase@google.com>
Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      ee69c217
    • Josh Bleecher Snyder's avatar
      cmd/compile: avoid checkwidth of [...] arrays · dccc653a
      Josh Bleecher Snyder authored 
      Fixes #20333

Change-Id: I0653cc859076f146d8ea8f5bd55cb22b0b8d987f
Reviewed-on: https://go-review.googlesource.com/43290
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarJoe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      dccc653a