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  1. 23 Mar, 2016 11 commits
    • Lynn Boger's avatar
      bytes: Equal perf improvements on ppc64le/ppc64 · baec1487
      Lynn Boger authored 
      The existing implementation for Equal and similar
functions in the bytes package operate on one byte at
at time.  This performs poorly on ppc64/ppc64le especially
when the byte buffers are large.  This change improves
those functions by loading and comparing double words where
possible.  The common code has been moved to a function
that can be shared by the other functions in this
file which perform the same type of comparison.
Further optimizations are done for the case where
>= 32 bytes are being compared.  The new function
memeqbody is used by memeq_varlen, Equal, and eqstring.

When running the bytes test with -test.bench=Equal

benchmark                     old MB/s     new MB/s     speedup
BenchmarkEqual1               164.83       129.49       0.79x
BenchmarkEqual6               563.51       445.47       0.79x
BenchmarkEqual9               656.15       1099.00      1.67x
BenchmarkEqual15              591.93       1024.30      1.73x
BenchmarkEqual16              613.25       1914.12      3.12x
BenchmarkEqual20              682.37       1687.04      2.47x
BenchmarkEqual32              807.96       3843.29      4.76x
BenchmarkEqual4K              1076.25      23280.51     21.63x
BenchmarkEqual4M              1079.30      13120.14     12.16x
BenchmarkEqual64M             1073.28      10876.92     10.13x

It was determined that the degradation in the smaller byte tests
were due to unfavorable code alignment of the single byte loop.

Fixes #14368

Change-Id: I0dd87382c28887c70f4fbe80877a8ba03c31d7cd
Reviewed-on: https://go-review.googlesource.com/20249Reviewed-by: default avatarMinux Ma <minux@golang.org>
      baec1487
    • Shahar Kohanim's avatar
      cmd/link: Clean up Pcln struct · 516c6b40
      Shahar Kohanim authored 
      Removes unnecessary fields from Pcln.

Change-Id: I175049ca749b510eedaf65162355bc4d7a93315e
Reviewed-on: https://go-review.googlesource.com/21041Reviewed-by: default avatarDavid Crawshaw <crawshaw@golang.org>
      516c6b40
    • Klaus Post's avatar
      compress/flate: rework matching algorithm · 53efe1e1
      Klaus Post authored 
      This changes how matching is done in deflate algorithm.

The major change is that we do not look for matches that are only
3 bytes in length, matches must be 4 bytes at least.
Contrary to what you would expect this actually improves the
compresion ratio, since 3 literal bytes will often be shorter
than a match after huffman encoding.
This varies a bit by source, but is most often the case when the
source is "easy" to compress.

Second of all, a "stronger" hash is used. The hash is similar to
the hashing function used by Snappy.

Overall, the speed impact is biggest on higher compression levels.
I intend to replace the "speed" compression level, which can be
seen in CL 21021.

The built-in benchmark using "digits" is slower at level 1.
I see this as an exception, since "digits" is a special type
of data, where you have low entropy (numbers 0->9), but no
significant matches. Again, CL 20021 fixes that case.

NewWriterDict is also made considerably faster, by not running data
through the entire encoder. This is not reflected by the benchmark.

Overall, the speed impact is biggest on higher compression levels.
I intend to replace the "speed" compression level.

COMPARED to tip/master:
name                       old time/op    new time/op     delta
EncodeDigitsSpeed1e4-4        401µs ± 1%      345µs ± 2%   -13.95%
EncodeDigitsSpeed1e5-4       3.19ms ± 1%     4.27ms ± 3%   +33.96%
EncodeDigitsSpeed1e6-4       27.7ms ± 4%     43.8ms ± 3%   +58.00%
EncodeDigitsDefault1e4-4      641µs ± 0%      403µs ± 1%   -37.15%
EncodeDigitsDefault1e5-4     13.8ms ± 1%      6.4ms ± 3%   -53.73%
EncodeDigitsDefault1e6-4      162ms ± 1%       64ms ± 2%   -60.51%
EncodeDigitsCompress1e4-4     627µs ± 1%      405µs ± 2%   -35.45%
EncodeDigitsCompress1e5-4    13.9ms ± 0%      6.3ms ± 2%   -54.46%
EncodeDigitsCompress1e6-4     159ms ± 1%       64ms ± 0%   -59.91%
EncodeTwainSpeed1e4-4         433µs ± 4%      331µs ± 1%   -23.53%
EncodeTwainSpeed1e5-4        2.82ms ± 1%     3.08ms ± 0%    +9.10%
EncodeTwainSpeed1e6-4        28.1ms ± 2%     28.8ms ± 0%    +2.82%
EncodeTwainDefault1e4-4       695µs ± 4%      474µs ± 1%   -31.78%
EncodeTwainDefault1e5-4      11.8ms ± 0%      7.4ms ± 0%   -37.31%
EncodeTwainDefault1e6-4       128ms ± 0%       75ms ± 0%   -40.93%
EncodeTwainCompress1e4-4      719µs ± 3%      480µs ± 0%   -33.27%
EncodeTwainCompress1e5-4     15.0ms ± 3%      8.2ms ± 2%   -45.55%
EncodeTwainCompress1e6-4      170ms ± 0%       85ms ± 1%   -49.99%

name                       old speed      new speed       delta
EncodeDigitsSpeed1e4-4     25.0MB/s ± 1%   29.0MB/s ± 2%   +16.24%
EncodeDigitsSpeed1e5-4     31.4MB/s ± 1%   23.4MB/s ± 3%   -25.34%
EncodeDigitsSpeed1e6-4     36.1MB/s ± 4%   22.8MB/s ± 3%   -36.74%
EncodeDigitsDefault1e4-4   15.6MB/s ± 0%   24.8MB/s ± 1%   +59.11%
EncodeDigitsDefault1e5-4   7.27MB/s ± 1%  15.72MB/s ± 3%  +116.23%
EncodeDigitsDefault1e6-4   6.16MB/s ± 0%  15.60MB/s ± 2%  +153.25%
EncodeDigitsCompress1e4-4  15.9MB/s ± 1%   24.7MB/s ± 2%   +54.97%
EncodeDigitsCompress1e5-4  7.19MB/s ± 0%  15.78MB/s ± 2%  +119.62%
EncodeDigitsCompress1e6-4  6.27MB/s ± 1%  15.65MB/s ± 0%  +149.52%
EncodeTwainSpeed1e4-4      23.1MB/s ± 4%   30.2MB/s ± 1%   +30.68%
EncodeTwainSpeed1e5-4      35.4MB/s ± 1%   32.5MB/s ± 0%    -8.34%
EncodeTwainSpeed1e6-4      35.6MB/s ± 2%   34.7MB/s ± 0%    -2.77%
EncodeTwainDefault1e4-4    14.4MB/s ± 4%   21.1MB/s ± 1%   +46.48%
EncodeTwainDefault1e5-4    8.49MB/s ± 0%  13.55MB/s ± 0%   +59.50%
EncodeTwainDefault1e6-4    7.83MB/s ± 0%  13.25MB/s ± 0%   +69.19%
EncodeTwainCompress1e4-4   13.9MB/s ± 3%   20.8MB/s ± 0%   +49.83%
EncodeTwainCompress1e5-4   6.65MB/s ± 3%  12.20MB/s ± 2%   +83.51%
EncodeTwainCompress1e6-4   5.88MB/s ± 0%  11.76MB/s ± 1%  +100.06%

Change-Id: I724e33c1dd3e3a6a1b0a68e094baa959352baf32
Reviewed-on: https://go-review.googlesource.com/20929
Run-TryBot: Nigel Tao <nigeltao@golang.org>
Reviewed-by: default avatarNigel Tao <nigeltao@golang.org>
      53efe1e1
    • Dave Cheney's avatar
      cmd/compile/internal/ssa: avoid string conversion in zcse · e6beec1f
      Dave Cheney authored 
      Some ssa.Type implementations fell through to gc.Tconv which generated
garbage to produce a string form of the Type.

name      old time/op    new time/op    delta
Template     405ms ± 7%     401ms ± 6%    ~     (p=0.478 n=20+20)
GoTypes      1.32s ± 1%     1.30s ± 2%  -1.27%  (p=0.000 n=19+20)
Compiler     6.07s ± 2%     6.03s ± 2%    ~     (p=0.121 n=20+20)

name      old alloc/op   new alloc/op   delta
Template    63.9MB ± 0%    63.7MB ± 0%  -0.21%  (p=0.000 n=19+20)
GoTypes      220MB ± 0%     219MB ± 0%  -0.21%  (p=0.000 n=20+20)
Compiler     966MB ± 0%     965MB ± 0%  -0.11%  (p=0.000 n=20+20)

name      old allocs/op  new allocs/op  delta
Template      708k ± 0%      701k ± 0%  -0.99%  (p=0.000 n=20+20)
GoTypes      2.20M ± 0%     2.17M ± 0%  -1.43%  (p=0.000 n=17+20)
Compiler     9.45M ± 0%     9.36M ± 0%  -0.91%  (p=0.000 n=20+20)

Change-Id: I5fcc30e0f76a823d1c301d4980b583d716a75ce3
Reviewed-on: https://go-review.googlesource.com/20844Reviewed-by: default avatarKeith Randall <khr@golang.org>
      e6beec1f
    • Dave Cheney's avatar
      cmd/compile/internal/gc: remove redundant Nod(OXXX, ...) pattern · a4be24cb
      Dave Cheney authored 
      The pattern

    n := Nod(OXXX, nil, nil)
    Nodconst(n, ...)

was a leftover from the C days where n must be heap allocated.

No change in benchmarks, none expected as n escapes anyway.

name      old time/op    new time/op    delta
Template     391ms ± 6%     388ms ± 5%    ~     (p=0.659 n=20+20)
GoTypes      1.27s ± 1%     1.27s ± 2%    ~     (p=0.828 n=18+20)
Compiler     6.16s ± 2%     6.15s ± 1%    ~     (p=0.947 n=20+20)

name      old alloc/op   new alloc/op   delta
Template    63.7MB ± 0%    63.7MB ± 0%    ~     (p=0.414 n=20+20)
GoTypes      219MB ± 0%     219MB ± 0%    ~     (p=0.904 n=20+20)
Compiler     980MB ± 0%     980MB ± 0%  +0.00%  (p=0.007 n=20+19)

name      old allocs/op  new allocs/op  delta
Template      586k ± 0%      586k ± 0%    ~     (p=0.564 n=19+20)
GoTypes      1.80M ± 0%     1.80M ± 0%    ~     (p=0.718 n=20+20)
Compiler     7.74M ± 0%     7.74M ± 0%    ~     (p=0.358 n=20+20)

The reuse of nc in multiple overlapping scopes in walk.go is the worst.

Change-Id: I4ed6a63f7ffbfff68124ad609f6e3a68d95cbbba
Reviewed-on: https://go-review.googlesource.com/21015Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      a4be24cb
    • Aliaksandr Valialkin's avatar
      cmd/vet: check lock copy in function calls and return statements · 1374515a
      Aliaksandr Valialkin authored 
      Fixes #14529

Change-Id: I6ed059d279ba0fe12d76416859659f28d61781d2
Reviewed-on: https://go-review.googlesource.com/20832
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: default avatarRob Pike <r@golang.org>
      1374515a
    • Martin Möhrmann's avatar
      fmt: cleanup and optimize doPrintf for simple formats · 49da9312
      Martin Möhrmann authored 
      Make a fast path for format strings that do not use
precision or width specifications or argument indices.

Only check and enforce the restriction to not pad left with zeros
in code paths that change either f.minus or f.zero.

Consolidate the if chains at the end of the main doPrintf loop
into a switch statement. Move error printing into extra
functions to reduce size of this switch statement.

name                             old time/op  new time/op  delta
SprintfPadding-2                  234ns ± 1%   233ns ± 1%   -0.54%  (p=0.010 n=19+19)
SprintfEmpty-2                   37.0ns ± 3%  39.1ns ±14%     ~     (p=0.501 n=17+20)
SprintfString-2                   112ns ± 1%   101ns ± 1%   -9.21%  (p=0.000 n=19+20)
SprintfTruncateString-2           139ns ± 1%   139ns ± 0%   +0.57%  (p=0.000 n=19+19)
SprintfQuoteString-2              402ns ± 0%   392ns ± 0%   -2.35%  (p=0.000 n=19+20)
SprintfInt-2                      114ns ± 1%   102ns ± 2%  -10.92%  (p=0.000 n=20+20)
SprintfIntInt-2                   177ns ± 2%   155ns ± 2%  -12.67%  (p=0.000 n=18+18)
SprintfPrefixedInt-2              260ns ± 3%   249ns ± 3%   -4.55%  (p=0.000 n=20+20)
SprintfFloat-2                    190ns ± 1%   178ns ± 2%   -6.54%  (p=0.000 n=20+20)
SprintfComplex-2                  533ns ± 1%   517ns ± 3%   -2.95%  (p=0.000 n=20+20)
SprintfBoolean-2                  102ns ± 1%    93ns ± 2%   -9.30%  (p=0.000 n=20+20)
SprintfHexString-2                176ns ± 0%   168ns ± 2%   -4.49%  (p=0.000 n=16+19)
SprintfHexBytes-2                 181ns ± 1%   174ns ± 2%   -4.27%  (p=0.000 n=20+20)
SprintfBytes-2                    326ns ± 1%   311ns ± 1%   -4.51%  (p=0.000 n=20+20)
ManyArgs-2                        540ns ± 2%   497ns ± 1%   -8.08%  (p=0.000 n=18+16)
FprintInt-2                       150ns ± 0%   149ns ± 0%   -0.33%  (p=0.000 n=20+18)
FprintfBytes-2                    185ns ± 0%   165ns ± 0%  -10.98%  (p=0.000 n=20+18)
FprintIntNoAlloc-2                113ns ± 0%   112ns ± 0%   -0.88%  (p=0.000 n=20+20)

Change-Id: I9ada8faa1f46aa67ea116a94ab3f4ad3e405c8fe
Reviewed-on: https://go-review.googlesource.com/20919
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarRob Pike <r@golang.org>
      49da9312
    • Tamir Duberstein's avatar
      database/sql/driver: remove string exclusion · 7162c4d0
      Tamir Duberstein authored 
      The exclusion of string from IsScanValue prevents driver authors from
writing their drivers in such a way that would allow users to
distinguish between strings and byte arrays returned from a database.
Such drivers are possible today, but require their authors to deviate
from the guidance provided by the standard library.

This exclusion has been in place since the birth of this package in
https://github.com/golang/go/commit/357f2cb1a385f4d1418e48856f9abe0cce,
but the fakedb implementation shipped in the same commit violates the
exclusion!

Strictly speaking this is a breaking change, but it increases the set
of permissible Scan types, and should not cause breakage in practice.

No test changes are necessary because fakedb already exercises this.

Fixes #6497.

Change-Id: I69dbd3a59d90464bcae8c852d7ec6c97bfd120f8
Reviewed-on: https://go-review.googlesource.com/19439
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
      7162c4d0
    • Ian Lance Taylor's avatar
      misc/cgo/testcarchive: rewrite test from bash to Go · bac0005e
      Ian Lance Taylor authored 
      This is to support https://golang.org/cl/18057, which is going to add
Windows support to this directory.  Better to write the test in Go then
to have both test.bash and test.bat.

Update #13494.

Change-Id: I4af7004416309e885049ee60b9470926282f210d
Reviewed-on: https://go-review.googlesource.com/20892
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
      bac0005e
    • Mikio Hara's avatar
      cmd/dist: disable misc/cgo/fortran test on dragonfly · bafa0275
      Mikio Hara authored 
      Updates #14544.

Change-Id: I24ab8e6f9ad9d290a672216fc2f50f78c3ed8812
Reviewed-on: https://go-review.googlesource.com/21014
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
      bafa0275
    • Keith Randall's avatar
      cmd/compile: MOVBload and MOVBQZXload are the same op · 68e86e6d
      Keith Randall authored 
      No need to have both ops when they do the same thing.
Just declare MOVBload to zero extend and we can get rid
of MOVBQZXload.  Same for W and L.

Kind of a followon cleanup for https://go-review.googlesource.com/c/19506/
Should enable an easier fix for #14920

Change-Id: I7cfac909a8ba387f433a6ae75c050740ebb34d42
Reviewed-on: https://go-review.googlesource.com/21004
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
      68e86e6d
  3. 22 Mar, 2016 18 commits
  5. 21 Mar, 2016 11 commits
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