delta/go-git.git/src/strings, branch master github.com: golang/go strings: correct NewReader documentation 2023-05-12T17:40:51+00:00 Jabar Asadi jasadi@d2iq.com 2023-05-10T21:44:14+00:00 9eceffdf12dc4497ee162c005d5e14bb509797b9 The provided description for `NewReader` says that the underlying string is read-only. but the following example shows that this is not the case. <br /> rd := strings.NewReader("this is a text") rd.Reset("new text") <--- underlying string gets updated here Change-Id: I95c7099c2e63670c84307d4317b702bf13a4025a GitHub-Last-Rev: a16a60b0f1e25d19e05e664c5b41ca57c4fcd9b2 GitHub-Pull-Request: golang/go#60074 Reviewed-on: https://go-review.googlesource.com/c/go/+/493817 Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> 
The provided description for `NewReader` says that the underlying string is read-only. but the following example shows that this is not the case.
<br />

rd := strings.NewReader("this is a text")

rd.Reset("new text") <--- underlying string gets updated here

Change-Id: I95c7099c2e63670c84307d4317b702bf13a4025a
GitHub-Last-Rev: a16a60b0f1e25d19e05e664c5b41ca57c4fcd9b2
GitHub-Pull-Request: golang/go#60074
Reviewed-on: https://go-review.googlesource.com/c/go/+/493817
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
bytes, strings: avoid unnecessary zero initialization 2023-02-27T19:11:00+00:00 Joe Tsai joetsai@digital-static.net 2022-12-08T11:51:04+00:00 132fae93b789ce512068ff4300c665b40635b74e Add bytealg.MakeNoZero that specially allocates a []byte without zeroing it. It assumes the caller will populate every byte. From within the bytes and strings packages, we can use bytealg.MakeNoZero in a way where our logic ensures that the entire slice is overwritten such that uninitialized bytes are never leaked to the end user. We use bytealg.MakeNoZero from within the following functions: * bytes.Join * bytes.Repeat * bytes.ToUpper * bytes.ToLower * strings.Builder.Grow The optimization in strings.Builder transitively benefits the following: * strings.Join * strings.Map * strings.Repeat * strings.ToUpper * strings.ToLower * strings.ToValidUTF8 * strings.Replace * any user logic that depends on strings.Builder This optimization is especially notable on large buffers that do not fit in the CPU cache, such that the cost of runtime.memclr and runtime.memmove are non-trivial since they are both limited by the relatively slow speed of physical RAM. Performance: RepeatLarge/256/1 66.0ns ± 3% 64.5ns ± 1% ~ (p=0.095 n=5+5) RepeatLarge/256/16 55.4ns ± 5% 53.1ns ± 3% -4.17% (p=0.016 n=5+5) RepeatLarge/512/1 95.5ns ± 7% 87.1ns ± 2% -8.78% (p=0.008 n=5+5) RepeatLarge/512/16 84.4ns ± 9% 76.2ns ± 5% -9.73% (p=0.016 n=5+5) RepeatLarge/1024/1 161ns ± 4% 144ns ± 7% -10.45% (p=0.016 n=5+5) RepeatLarge/1024/16 148ns ± 3% 141ns ± 5% ~ (p=0.095 n=5+5) RepeatLarge/2048/1 296ns ± 7% 288ns ± 5% ~ (p=0.841 n=5+5) RepeatLarge/2048/16 298ns ± 8% 281ns ± 5% ~ (p=0.151 n=5+5) RepeatLarge/4096/1 593ns ± 8% 539ns ± 8% -8.99% (p=0.032 n=5+5) RepeatLarge/4096/16 568ns ±12% 526ns ± 7% ~ (p=0.056 n=5+5) RepeatLarge/8192/1 1.15µs ± 8% 1.08µs ±12% ~ (p=0.095 n=5+5) RepeatLarge/8192/16 1.12µs ± 4% 1.07µs ± 7% ~ (p=0.310 n=5+5) RepeatLarge/8192/4097 1.77ns ± 1% 1.76ns ± 2% ~ (p=0.310 n=5+5) RepeatLarge/16384/1 2.06µs ± 7% 1.94µs ± 5% ~ (p=0.222 n=5+5) RepeatLarge/16384/16 2.02µs ± 4% 1.92µs ± 6% ~ (p=0.095 n=5+5) RepeatLarge/16384/4097 1.50µs ±15% 1.44µs ±11% ~ (p=0.802 n=5+5) RepeatLarge/32768/1 3.90µs ± 8% 3.65µs ±11% ~ (p=0.151 n=5+5) RepeatLarge/32768/16 3.92µs ±14% 3.68µs ±12% ~ (p=0.222 n=5+5) RepeatLarge/32768/4097 3.71µs ± 5% 3.43µs ± 4% -7.54% (p=0.032 n=5+5) RepeatLarge/65536/1 7.47µs ± 8% 6.88µs ± 9% ~ (p=0.056 n=5+5) RepeatLarge/65536/16 7.29µs ± 4% 6.74µs ± 6% -7.60% (p=0.016 n=5+5) RepeatLarge/65536/4097 7.90µs ±11% 6.34µs ± 5% -19.81% (p=0.008 n=5+5) RepeatLarge/131072/1 17.0µs ±18% 14.1µs ± 6% -17.32% (p=0.008 n=5+5) RepeatLarge/131072/16 15.2µs ± 2% 16.2µs ±17% ~ (p=0.151 n=5+5) RepeatLarge/131072/4097 15.7µs ± 6% 14.8µs ±11% ~ (p=0.095 n=5+5) RepeatLarge/262144/1 30.4µs ± 5% 31.4µs ±13% ~ (p=0.548 n=5+5) RepeatLarge/262144/16 30.1µs ± 4% 30.7µs ±11% ~ (p=1.000 n=5+5) RepeatLarge/262144/4097 31.2µs ± 7% 32.7µs ±13% ~ (p=0.310 n=5+5) RepeatLarge/524288/1 67.5µs ± 9% 63.7µs ± 3% ~ (p=0.095 n=5+5) RepeatLarge/524288/16 67.2µs ± 5% 62.9µs ± 6% ~ (p=0.151 n=5+5) RepeatLarge/524288/4097 65.5µs ± 4% 65.2µs ±18% ~ (p=0.548 n=5+5) RepeatLarge/1048576/1 141µs ± 6% 137µs ±14% ~ (p=0.421 n=5+5) RepeatLarge/1048576/16 140µs ± 2% 134µs ±11% ~ (p=0.222 n=5+5) RepeatLarge/1048576/4097 141µs ± 3% 134µs ±10% ~ (p=0.151 n=5+5) RepeatLarge/2097152/1 258µs ± 2% 271µs ±10% ~ (p=0.222 n=5+5) RepeatLarge/2097152/16 263µs ± 6% 273µs ± 9% ~ (p=0.151 n=5+5) RepeatLarge/2097152/4097 270µs ± 2% 277µs ± 6% ~ (p=0.690 n=5+5) RepeatLarge/4194304/1 684µs ± 3% 467µs ± 6% -31.69% (p=0.008 n=5+5) RepeatLarge/4194304/16 682µs ± 1% 471µs ± 7% -30.91% (p=0.008 n=5+5) RepeatLarge/4194304/4097 685µs ± 2% 465µs ±20% -32.12% (p=0.008 n=5+5) RepeatLarge/8388608/1 1.50ms ± 1% 1.16ms ± 8% -22.63% (p=0.008 n=5+5) RepeatLarge/8388608/16 1.50ms ± 2% 1.22ms ±17% -18.49% (p=0.008 n=5+5) RepeatLarge/8388608/4097 1.51ms ± 7% 1.33ms ±11% -11.56% (p=0.008 n=5+5) RepeatLarge/16777216/1 3.48ms ± 4% 2.66ms ±13% -23.76% (p=0.008 n=5+5) RepeatLarge/16777216/16 3.37ms ± 3% 2.57ms ±13% -23.72% (p=0.008 n=5+5) RepeatLarge/16777216/4097 3.38ms ± 9% 2.50ms ±11% -26.16% (p=0.008 n=5+5) RepeatLarge/33554432/1 7.74ms ± 1% 4.70ms ±19% -39.31% (p=0.016 n=4+5) RepeatLarge/33554432/16 7.90ms ± 4% 4.78ms ± 9% -39.50% (p=0.008 n=5+5) RepeatLarge/33554432/4097 7.80ms ± 2% 4.86ms ±11% -37.60% (p=0.008 n=5+5) RepeatLarge/67108864/1 16.4ms ± 3% 9.7ms ±15% -41.29% (p=0.008 n=5+5) RepeatLarge/67108864/16 16.5ms ± 1% 9.9ms ±15% -39.83% (p=0.008 n=5+5) RepeatLarge/67108864/4097 16.5ms ± 1% 11.0ms ±18% -32.95% (p=0.008 n=5+5) RepeatLarge/134217728/1 35.2ms ±12% 19.2ms ±10% -45.58% (p=0.008 n=5+5) RepeatLarge/134217728/16 34.6ms ± 6% 19.3ms ± 7% -44.07% (p=0.008 n=5+5) RepeatLarge/134217728/4097 33.2ms ± 2% 19.3ms ±14% -41.79% (p=0.008 n=5+5) RepeatLarge/268435456/1 70.9ms ± 2% 36.2ms ± 5% -48.87% (p=0.008 n=5+5) RepeatLarge/268435456/16 77.4ms ± 7% 36.1ms ± 8% -53.33% (p=0.008 n=5+5) RepeatLarge/268435456/4097 75.8ms ± 4% 37.0ms ± 4% -51.15% (p=0.008 n=5+5) RepeatLarge/536870912/1 163ms ±14% 77ms ± 9% -52.94% (p=0.008 n=5+5) RepeatLarge/536870912/16 156ms ± 4% 76ms ± 6% -51.42% (p=0.008 n=5+5) RepeatLarge/536870912/4097 151ms ± 2% 76ms ± 6% -49.64% (p=0.008 n=5+5) RepeatLarge/1073741824/1 293ms ± 5% 149ms ± 8% -49.18% (p=0.008 n=5+5) RepeatLarge/1073741824/16 308ms ± 9% 150ms ± 8% -51.19% (p=0.008 n=5+5) RepeatLarge/1073741824/4097 299ms ± 5% 151ms ± 6% -49.51% (p=0.008 n=5+5) Updates #57153 Change-Id: I024553b7e676d6da6408278109ac1fa8def0a802 Reviewed-on: https://go-review.googlesource.com/c/go/+/456336 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Joseph Tsai <joetsai@digital-static.net> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> 
Add bytealg.MakeNoZero that specially allocates a []byte
without zeroing it. It assumes the caller will populate every byte.
From within the bytes and strings packages, we can use
bytealg.MakeNoZero in a way where our logic ensures that
the entire slice is overwritten such that uninitialized bytes
are never leaked to the end user.

We use bytealg.MakeNoZero from within the following functions:

* bytes.Join
* bytes.Repeat
* bytes.ToUpper
* bytes.ToLower
* strings.Builder.Grow

The optimization in strings.Builder transitively benefits the following:

* strings.Join
* strings.Map
* strings.Repeat
* strings.ToUpper
* strings.ToLower
* strings.ToValidUTF8
* strings.Replace
* any user logic that depends on strings.Builder

This optimization is especially notable on large buffers that
do not fit in the CPU cache, such that the cost of
runtime.memclr and runtime.memmove are non-trivial since they are
both limited by the relatively slow speed of physical RAM.

Performance:

	RepeatLarge/256/1             66.0ns ± 3%    64.5ns ± 1%      ~     (p=0.095 n=5+5)
	RepeatLarge/256/16            55.4ns ± 5%    53.1ns ± 3%    -4.17%  (p=0.016 n=5+5)
	RepeatLarge/512/1             95.5ns ± 7%    87.1ns ± 2%    -8.78%  (p=0.008 n=5+5)
	RepeatLarge/512/16            84.4ns ± 9%    76.2ns ± 5%    -9.73%  (p=0.016 n=5+5)
	RepeatLarge/1024/1             161ns ± 4%     144ns ± 7%   -10.45%  (p=0.016 n=5+5)
	RepeatLarge/1024/16            148ns ± 3%     141ns ± 5%      ~     (p=0.095 n=5+5)
	RepeatLarge/2048/1             296ns ± 7%     288ns ± 5%      ~     (p=0.841 n=5+5)
	RepeatLarge/2048/16            298ns ± 8%     281ns ± 5%      ~     (p=0.151 n=5+5)
	RepeatLarge/4096/1             593ns ± 8%     539ns ± 8%    -8.99%  (p=0.032 n=5+5)
	RepeatLarge/4096/16            568ns ±12%     526ns ± 7%      ~     (p=0.056 n=5+5)
	RepeatLarge/8192/1            1.15µs ± 8%    1.08µs ±12%      ~     (p=0.095 n=5+5)
	RepeatLarge/8192/16           1.12µs ± 4%    1.07µs ± 7%      ~     (p=0.310 n=5+5)
	RepeatLarge/8192/4097         1.77ns ± 1%    1.76ns ± 2%      ~     (p=0.310 n=5+5)
	RepeatLarge/16384/1           2.06µs ± 7%    1.94µs ± 5%      ~     (p=0.222 n=5+5)
	RepeatLarge/16384/16          2.02µs ± 4%    1.92µs ± 6%      ~     (p=0.095 n=5+5)
	RepeatLarge/16384/4097        1.50µs ±15%    1.44µs ±11%      ~     (p=0.802 n=5+5)
	RepeatLarge/32768/1           3.90µs ± 8%    3.65µs ±11%      ~     (p=0.151 n=5+5)
	RepeatLarge/32768/16          3.92µs ±14%    3.68µs ±12%      ~     (p=0.222 n=5+5)
	RepeatLarge/32768/4097        3.71µs ± 5%    3.43µs ± 4%    -7.54%  (p=0.032 n=5+5)
	RepeatLarge/65536/1           7.47µs ± 8%    6.88µs ± 9%      ~     (p=0.056 n=5+5)
	RepeatLarge/65536/16          7.29µs ± 4%    6.74µs ± 6%    -7.60%  (p=0.016 n=5+5)
	RepeatLarge/65536/4097        7.90µs ±11%    6.34µs ± 5%   -19.81%  (p=0.008 n=5+5)
	RepeatLarge/131072/1          17.0µs ±18%    14.1µs ± 6%   -17.32%  (p=0.008 n=5+5)
	RepeatLarge/131072/16         15.2µs ± 2%    16.2µs ±17%      ~     (p=0.151 n=5+5)
	RepeatLarge/131072/4097       15.7µs ± 6%    14.8µs ±11%      ~     (p=0.095 n=5+5)
	RepeatLarge/262144/1          30.4µs ± 5%    31.4µs ±13%      ~     (p=0.548 n=5+5)
	RepeatLarge/262144/16         30.1µs ± 4%    30.7µs ±11%      ~     (p=1.000 n=5+5)
	RepeatLarge/262144/4097       31.2µs ± 7%    32.7µs ±13%      ~     (p=0.310 n=5+5)
	RepeatLarge/524288/1          67.5µs ± 9%    63.7µs ± 3%      ~     (p=0.095 n=5+5)
	RepeatLarge/524288/16         67.2µs ± 5%    62.9µs ± 6%      ~     (p=0.151 n=5+5)
	RepeatLarge/524288/4097       65.5µs ± 4%    65.2µs ±18%      ~     (p=0.548 n=5+5)
	RepeatLarge/1048576/1          141µs ± 6%     137µs ±14%      ~     (p=0.421 n=5+5)
	RepeatLarge/1048576/16         140µs ± 2%     134µs ±11%      ~     (p=0.222 n=5+5)
	RepeatLarge/1048576/4097       141µs ± 3%     134µs ±10%      ~     (p=0.151 n=5+5)
	RepeatLarge/2097152/1          258µs ± 2%     271µs ±10%      ~     (p=0.222 n=5+5)
	RepeatLarge/2097152/16         263µs ± 6%     273µs ± 9%      ~     (p=0.151 n=5+5)
	RepeatLarge/2097152/4097       270µs ± 2%     277µs ± 6%      ~     (p=0.690 n=5+5)
	RepeatLarge/4194304/1          684µs ± 3%     467µs ± 6%   -31.69%  (p=0.008 n=5+5)
	RepeatLarge/4194304/16         682µs ± 1%     471µs ± 7%   -30.91%  (p=0.008 n=5+5)
	RepeatLarge/4194304/4097       685µs ± 2%     465µs ±20%   -32.12%  (p=0.008 n=5+5)
	RepeatLarge/8388608/1         1.50ms ± 1%    1.16ms ± 8%   -22.63%  (p=0.008 n=5+5)
	RepeatLarge/8388608/16        1.50ms ± 2%    1.22ms ±17%   -18.49%  (p=0.008 n=5+5)
	RepeatLarge/8388608/4097      1.51ms ± 7%    1.33ms ±11%   -11.56%  (p=0.008 n=5+5)
	RepeatLarge/16777216/1        3.48ms ± 4%    2.66ms ±13%   -23.76%  (p=0.008 n=5+5)
	RepeatLarge/16777216/16       3.37ms ± 3%    2.57ms ±13%   -23.72%  (p=0.008 n=5+5)
	RepeatLarge/16777216/4097     3.38ms ± 9%    2.50ms ±11%   -26.16%  (p=0.008 n=5+5)
	RepeatLarge/33554432/1        7.74ms ± 1%    4.70ms ±19%   -39.31%  (p=0.016 n=4+5)
	RepeatLarge/33554432/16       7.90ms ± 4%    4.78ms ± 9%   -39.50%  (p=0.008 n=5+5)
	RepeatLarge/33554432/4097     7.80ms ± 2%    4.86ms ±11%   -37.60%  (p=0.008 n=5+5)
	RepeatLarge/67108864/1        16.4ms ± 3%     9.7ms ±15%   -41.29%  (p=0.008 n=5+5)
	RepeatLarge/67108864/16       16.5ms ± 1%     9.9ms ±15%   -39.83%  (p=0.008 n=5+5)
	RepeatLarge/67108864/4097     16.5ms ± 1%    11.0ms ±18%   -32.95%  (p=0.008 n=5+5)
	RepeatLarge/134217728/1       35.2ms ±12%    19.2ms ±10%   -45.58%  (p=0.008 n=5+5)
	RepeatLarge/134217728/16      34.6ms ± 6%    19.3ms ± 7%   -44.07%  (p=0.008 n=5+5)
	RepeatLarge/134217728/4097    33.2ms ± 2%    19.3ms ±14%   -41.79%  (p=0.008 n=5+5)
	RepeatLarge/268435456/1       70.9ms ± 2%    36.2ms ± 5%   -48.87%  (p=0.008 n=5+5)
	RepeatLarge/268435456/16      77.4ms ± 7%    36.1ms ± 8%   -53.33%  (p=0.008 n=5+5)
	RepeatLarge/268435456/4097    75.8ms ± 4%    37.0ms ± 4%   -51.15%  (p=0.008 n=5+5)
	RepeatLarge/536870912/1        163ms ±14%      77ms ± 9%   -52.94%  (p=0.008 n=5+5)
	RepeatLarge/536870912/16       156ms ± 4%      76ms ± 6%   -51.42%  (p=0.008 n=5+5)
	RepeatLarge/536870912/4097     151ms ± 2%      76ms ± 6%   -49.64%  (p=0.008 n=5+5)
	RepeatLarge/1073741824/1       293ms ± 5%     149ms ± 8%   -49.18%  (p=0.008 n=5+5)
	RepeatLarge/1073741824/16      308ms ± 9%     150ms ± 8%   -51.19%  (p=0.008 n=5+5)
	RepeatLarge/1073741824/4097    299ms ± 5%     151ms ± 6%   -49.51%  (p=0.008 n=5+5)

Updates #57153

Change-Id: I024553b7e676d6da6408278109ac1fa8def0a802
Reviewed-on: https://go-review.googlesource.com/c/go/+/456336
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
bytes, strings: add ContainsFunc 2023-01-24T22:06:45+00:00 hopehook hopehook@qq.com 2023-01-03T08:23:16+00:00 0b3f58c48e3298e49e27f80dc748f0652339d63e Fixes #54386. Change-Id: I78747da337ed6129e4f7426dd0483a644bed82e3 Reviewed-on: https://go-review.googlesource.com/c/go/+/460216 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: hopehook <hopehook@golangcn.org> Auto-Submit: Ian Lance Taylor <iant@golang.org> 
Fixes #54386.

Change-Id: I78747da337ed6129e4f7426dd0483a644bed82e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/460216
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: hopehook <hopehook@golangcn.org>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
bytes,strings: add some examples 2023-01-20T23:21:39+00:00 fangguizhen 1297394526@qq.com 2023-01-20T09:43:40+00:00 85b49d7f21dfbee9946bece01a168de239094716 Change-Id: Ic93ad59119f3549c0f13c4f366f71e9d01b88c47 GitHub-Last-Rev: afb518047288976f440d3fe0d65923c1905a9b26 GitHub-Pull-Request: golang/go#57907 Reviewed-on: https://go-review.googlesource.com/c/go/+/462283 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com> 
Change-Id: Ic93ad59119f3549c0f13c4f366f71e9d01b88c47
GitHub-Last-Rev: afb518047288976f440d3fe0d65923c1905a9b26
GitHub-Pull-Request: golang/go#57907
Reviewed-on: https://go-review.googlesource.com/c/go/+/462283
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
bytes, strings: rename field in CutSuffix tests 2023-01-20T01:25:45+00:00 fangguizhen 1297394526@qq.com 2023-01-19T03:12:12+00:00 e590afcf2c2d046b1a4b6a11986a8e38a2b93ed7 Change-Id: I63181f6540fc1bfcfc988a16bf9fafbd3575cfdf GitHub-Last-Rev: d90528730a92a087866c1bfc227a0a0bf1cdffbe GitHub-Pull-Request: golang/go#57909 Reviewed-on: https://go-review.googlesource.com/c/go/+/462284 Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> 
Change-Id: I63181f6540fc1bfcfc988a16bf9fafbd3575cfdf
GitHub-Last-Rev: d90528730a92a087866c1bfc227a0a0bf1cdffbe
GitHub-Pull-Request: golang/go#57909
Reviewed-on: https://go-review.googlesource.com/c/go/+/462284
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
strings: remove redundant symbols 2023-01-17T17:24:17+00:00 fangguizhen 1297394526@qq.com 2023-01-17T16:37:42+00:00 8e199294361de59b637f25a7d5eebdee1b131415 Change-Id: Ie3fe0274288d6cb6303acdcec1340c480e5c0b20 GitHub-Last-Rev: ce9d44619e970b1319fbccf3aace1ddf719bcec1 GitHub-Pull-Request: golang/go#57848 Reviewed-on: https://go-review.googlesource.com/c/go/+/462277 Run-TryBot: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Keith Randall <khr@golang.org> 
Change-Id: Ie3fe0274288d6cb6303acdcec1340c480e5c0b20
GitHub-Last-Rev: ce9d44619e970b1319fbccf3aace1ddf719bcec1
GitHub-Pull-Request: golang/go#57848
Reviewed-on: https://go-review.googlesource.com/c/go/+/462277
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
internal/bytealg: fix bug in index function for ppc64le/power9 2022-10-31T12:52:07+00:00 Archana R aravind5@in.ibm.com 2022-10-28T07:42:39+00:00 6774ddfec758ecf2cc64d58392c438dd64660a00 The index function was not handling certain corner cases where there were two more bytes to be examined in the tail end of the string to complete the comparison. Fix code to ensure that when the string has to be shifted two more times the correct bytes are examined. Also hoisted vsplat to V10 so that all paths use the correct value. Some comments had incorrect register names and corrected the same. Added the strings that were failing to strings test for verification. Fixes #56457 Change-Id: Idba7cbc802e3d73c8f4fe89309871cc8447792f5 Reviewed-on: https://go-review.googlesource.com/c/go/+/446135 Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Heschi Kreinick <heschi@google.com> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Archana Ravindar <ravindararchana@gmail.com> 
The index function was not handling certain corner cases where there
were two more bytes to be examined in the tail end of the string to
complete the comparison. Fix code to ensure that when the string has
to be shifted two more times the correct bytes are examined.
Also hoisted vsplat to V10 so that all paths use the correct value.
Some comments had incorrect register names and corrected the same.
Added the strings that were failing to strings test for verification.

Fixes #56457

Change-Id: Idba7cbc802e3d73c8f4fe89309871cc8447792f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/446135
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Archana Ravindar <ravindararchana@gmail.com>
bytes,strings: optimize Repeat 2022-09-27T16:55:15+00:00 Carlo Alberto Ferraris cafxx@strayorange.com 2022-07-22T05:18:33+00:00 dcb90152a444be97fcc45bb12d176641c1b0d90e When generating long strings or slices with Repeat we currently reuse intermediate states as a way to quickly build exponentially longer results. This works well as long as the intermediate states fit into the processor D-cache. If they don't we start thrashing the D-cache by reading in the whole intermediate state over and over on each iteration. Instead, once we reach a large enough intermediate state (that allows the memcpy operation to perform at peak) we cap the size of chunk of the state that is used as source for subsequent appends. This ensures that this smaller source chunk is always present in the D-cache, and the append operation does not need to read the state contents from memory. Currently the cap is set to 8KB, a number derived via experimentation to yield the highest performance across a a large range of result sizes. Slightly higher caps also produced similar results: 8KB was chosen as the smallest one in this performance plateau with the intention to minimize D-cache pollution. For result sizes larger than the fastest cache levels we get significantly higher performance compared to the current implementation: strings: name old speed new speed delta RepeatLarge/256/1-16 1.73GB/s ± 1% 1.73GB/s ± 0% ~ (p=0.556 n=5+4) RepeatLarge/256/16-16 2.02GB/s ± 0% 1.95GB/s ± 8% ~ (p=0.222 n=5+5) RepeatLarge/512/1-16 2.30GB/s ±13% 2.47GB/s ± 1% ~ (p=0.548 n=5+5) RepeatLarge/512/16-16 2.38GB/s ±16% 2.77GB/s ± 1% +16.27% (p=0.032 n=5+5) RepeatLarge/1024/1-16 3.17GB/s ± 1% 3.18GB/s ± 0% ~ (p=0.730 n=4+5) RepeatLarge/1024/16-16 3.39GB/s ± 2% 3.38GB/s ± 1% ~ (p=0.548 n=5+5) RepeatLarge/2048/1-16 3.32GB/s ± 2% 3.32GB/s ± 2% ~ (p=1.000 n=5+5) RepeatLarge/2048/16-16 3.41GB/s ± 4% 3.46GB/s ± 2% ~ (p=0.310 n=5+5) RepeatLarge/4096/1-16 3.60GB/s ± 4% 3.67GB/s ± 3% ~ (p=0.690 n=5+5) RepeatLarge/4096/16-16 3.74GB/s ± 3% 3.71GB/s ± 5% ~ (p=0.690 n=5+5) RepeatLarge/8192/1-16 3.94GB/s ± 4% 4.01GB/s ± 1% ~ (p=0.222 n=5+5) RepeatLarge/8192/16-16 3.94GB/s ± 6% 4.05GB/s ± 1% ~ (p=0.222 n=5+5) RepeatLarge/8192/4097-16 4.25GB/s ± 6% 4.32GB/s ± 3% ~ (p=0.690 n=5+5) RepeatLarge/16384/1-16 4.96GB/s ± 1% 5.02GB/s ± 2% ~ (p=0.421 n=5+5) RepeatLarge/16384/16-16 4.99GB/s ± 2% 5.07GB/s ± 1% ~ (p=0.421 n=5+5) RepeatLarge/16384/4097-16 5.15GB/s ± 3% 5.17GB/s ± 1% ~ (p=1.000 n=5+5) RepeatLarge/32768/1-16 5.44GB/s ± 2% 5.42GB/s ± 1% ~ (p=0.841 n=5+5) RepeatLarge/32768/16-16 5.46GB/s ± 4% 5.44GB/s ± 1% ~ (p=0.905 n=5+4) RepeatLarge/32768/4097-16 4.84GB/s ± 2% 4.59GB/s ±12% -5.05% (p=0.032 n=5+5) RepeatLarge/65536/1-16 5.85GB/s ± 0% 5.84GB/s ± 1% ~ (p=0.690 n=5+5) RepeatLarge/65536/16-16 5.81GB/s ± 2% 5.84GB/s ± 2% ~ (p=0.421 n=5+5) RepeatLarge/65536/4097-16 5.38GB/s ± 6% 5.45GB/s ± 1% ~ (p=1.000 n=5+5) RepeatLarge/131072/1-16 6.20GB/s ± 1% 6.31GB/s ± 1% +1.80% (p=0.008 n=5+5) RepeatLarge/131072/16-16 6.12GB/s ± 3% 6.25GB/s ± 3% ~ (p=0.095 n=5+5) RepeatLarge/131072/4097-16 5.95GB/s ± 1% 5.85GB/s ±10% ~ (p=1.000 n=5+5) RepeatLarge/262144/1-16 6.33GB/s ± 1% 6.56GB/s ± 0% +3.62% (p=0.016 n=5+4) RepeatLarge/262144/16-16 6.42GB/s ± 0% 6.65GB/s ± 1% +3.58% (p=0.016 n=4+5) RepeatLarge/262144/4097-16 6.31GB/s ± 1% 6.44GB/s ± 1% +1.94% (p=0.008 n=5+5) RepeatLarge/524288/1-16 6.23GB/s ± 1% 6.92GB/s ± 3% +11.02% (p=0.008 n=5+5) RepeatLarge/524288/16-16 6.24GB/s ± 1% 6.97GB/s ± 2% +11.77% (p=0.016 n=4+5) RepeatLarge/524288/4097-16 6.14GB/s ± 2% 6.73GB/s ± 3% +9.50% (p=0.008 n=5+5) RepeatLarge/1048576/1-16 5.23GB/s ± 1% 6.53GB/s ± 6% +24.85% (p=0.008 n=5+5) RepeatLarge/1048576/16-16 5.21GB/s ± 1% 6.56GB/s ± 4% +25.93% (p=0.008 n=5+5) RepeatLarge/1048576/4097-16 5.22GB/s ± 1% 6.26GB/s ± 2% +20.09% (p=0.008 n=5+5) RepeatLarge/2097152/1-16 3.95GB/s ± 1% 5.96GB/s ± 1% +51.01% (p=0.008 n=5+5) RepeatLarge/2097152/16-16 3.94GB/s ± 1% 5.98GB/s ± 2% +51.99% (p=0.008 n=5+5) RepeatLarge/2097152/4097-16 4.94GB/s ± 1% 5.71GB/s ± 2% +15.63% (p=0.008 n=5+5) RepeatLarge/4194304/1-16 3.10GB/s ± 1% 5.89GB/s ± 1% +89.90% (p=0.008 n=5+5) RepeatLarge/4194304/16-16 3.09GB/s ± 1% 5.86GB/s ± 1% +89.89% (p=0.008 n=5+5) RepeatLarge/4194304/4097-16 3.13GB/s ± 1% 5.89GB/s ± 1% +88.36% (p=0.008 n=5+5) RepeatLarge/8388608/1-16 3.06GB/s ± 1% 6.31GB/s ±16% +105.84% (p=0.008 n=5+5) RepeatLarge/8388608/16-16 3.08GB/s ± 1% 6.62GB/s ± 1% +114.66% (p=0.008 n=5+5) RepeatLarge/8388608/4097-16 3.13GB/s ± 2% 6.87GB/s ± 1% +119.62% (p=0.008 n=5+5) RepeatLarge/16777216/1-16 3.21GB/s ± 3% 5.88GB/s ± 1% +83.27% (p=0.008 n=5+5) RepeatLarge/16777216/16-16 3.23GB/s ± 2% 5.84GB/s ± 2% +80.49% (p=0.008 n=5+5) RepeatLarge/16777216/4097-16 3.30GB/s ± 6% 5.88GB/s ± 2% +78.18% (p=0.008 n=5+5) RepeatLarge/33554432/1-16 3.71GB/s ± 3% 5.91GB/s ± 2% +59.17% (p=0.008 n=5+5) RepeatLarge/33554432/16-16 3.67GB/s ± 3% 5.91GB/s ± 2% +61.13% (p=0.008 n=5+5) RepeatLarge/33554432/4097-16 3.71GB/s ± 1% 5.77GB/s ± 6% +55.51% (p=0.008 n=5+5) RepeatLarge/67108864/1-16 4.61GB/s ±11% 6.00GB/s ± 5% +30.15% (p=0.008 n=5+5) RepeatLarge/67108864/16-16 4.62GB/s ± 7% 6.11GB/s ± 2% +32.35% (p=0.008 n=5+5) RepeatLarge/67108864/4097-16 4.71GB/s ± 2% 6.24GB/s ± 2% +32.60% (p=0.008 n=5+5) RepeatLarge/134217728/1-16 4.53GB/s ± 8% 6.28GB/s ±11% +38.57% (p=0.008 n=5+5) RepeatLarge/134217728/16-16 4.78GB/s ± 3% 6.36GB/s ± 3% +33.16% (p=0.008 n=5+5) RepeatLarge/134217728/4097-16 4.73GB/s ± 6% 6.46GB/s ± 3% +36.63% (p=0.008 n=5+5) RepeatLarge/268435456/1-16 4.09GB/s ±25% 6.37GB/s ±19% +56.00% (p=0.008 n=5+5) RepeatLarge/268435456/16-16 4.50GB/s ± 4% 6.86GB/s ± 0% +52.49% (p=0.016 n=5+4) RepeatLarge/268435456/4097-16 4.73GB/s ± 5% 6.90GB/s ± 0% +45.94% (p=0.008 n=5+5) RepeatLarge/536870912/1-16 4.38GB/s ±36% 6.52GB/s ± 8% +48.68% (p=0.008 n=5+5) RepeatLarge/536870912/16-16 4.69GB/s ±12% 6.90GB/s ± 1% +46.97% (p=0.008 n=5+5) RepeatLarge/536870912/4097-16 4.87GB/s ± 8% 6.98GB/s ± 0% +43.36% (p=0.008 n=5+5) RepeatLarge/1073741824/1-16 3.87GB/s ±28% 6.96GB/s ± 1% +79.94% (p=0.016 n=5+4) RepeatLarge/1073741824/16-16 4.79GB/s ± 9% 6.93GB/s ± 0% +44.79% (p=0.008 n=5+5) RepeatLarge/1073741824/4097-16 4.65GB/s ± 8% 7.02GB/s ± 1% +51.02% (p=0.008 n=5+5) bytes: name old speed new speed delta RepeatLarge/256/1-16 1.93GB/s ± 1% 1.84GB/s ± 1% -4.81% (p=0.000 n=10+10) RepeatLarge/256/16-16 2.25GB/s ± 2% 2.15GB/s ± 1% -4.45% (p=0.000 n=9+8) RepeatLarge/512/1-16 2.71GB/s ± 1% 2.62GB/s ± 1% -3.27% (p=0.000 n=10+9) RepeatLarge/512/16-16 2.96GB/s ± 4% 2.91GB/s ± 1% ~ (p=0.243 n=9+10) RepeatLarge/1024/1-16 3.35GB/s ± 1% 3.27GB/s ± 1% -2.61% (p=0.000 n=9+10) RepeatLarge/1024/16-16 3.56GB/s ± 2% 3.52GB/s ± 1% -1.10% (p=0.010 n=10+9) RepeatLarge/2048/1-16 3.52GB/s ± 1% 3.45GB/s ± 1% -1.92% (p=0.000 n=10+10) RepeatLarge/2048/16-16 3.61GB/s ± 1% 3.58GB/s ± 0% -0.82% (p=0.008 n=9+8) RepeatLarge/4096/1-16 3.85GB/s ± 2% 3.80GB/s ± 2% ~ (p=0.165 n=10+10) RepeatLarge/4096/16-16 3.88GB/s ± 3% 3.84GB/s ± 4% ~ (p=0.393 n=10+10) RepeatLarge/8192/1-16 4.12GB/s ± 2% 4.04GB/s ± 1% -1.96% (p=0.000 n=10+10) RepeatLarge/8192/16-16 4.11GB/s ± 2% 4.09GB/s ± 1% ~ (p=0.278 n=9+10) RepeatLarge/8192/4097-16 4.38GB/s ± 1% 4.39GB/s ± 4% ~ (p=0.720 n=9+10) RepeatLarge/16384/1-16 5.06GB/s ± 2% 4.95GB/s ± 3% -2.29% (p=0.001 n=10+9) RepeatLarge/16384/16-16 5.11GB/s ± 3% 5.06GB/s ± 3% ~ (p=0.315 n=10+9) RepeatLarge/16384/4097-16 5.22GB/s ± 3% 5.26GB/s ± 3% ~ (p=0.211 n=9+10) RepeatLarge/32768/1-16 5.54GB/s ± 2% 5.50GB/s ± 3% ~ (p=0.353 n=10+10) RepeatLarge/32768/16-16 5.55GB/s ± 1% 5.60GB/s ± 1% +0.91% (p=0.035 n=10+9) RepeatLarge/32768/4097-16 4.88GB/s ± 2% 4.85GB/s ± 2% ~ (p=0.447 n=10+9) RepeatLarge/65536/1-16 5.86GB/s ± 1% 5.93GB/s ± 2% +1.18% (p=0.043 n=8+10) RepeatLarge/65536/16-16 5.83GB/s ± 2% 5.98GB/s ± 1% +2.67% (p=0.000 n=10+10) RepeatLarge/65536/4097-16 5.57GB/s ± 0% 5.56GB/s ± 3% ~ (p=0.696 n=8+10) RepeatLarge/131072/1-16 6.23GB/s ± 1% 6.38GB/s ± 2% +2.51% (p=0.000 n=9+10) RepeatLarge/131072/16-16 6.21GB/s ± 2% 6.37GB/s ± 1% +2.72% (p=0.000 n=9+10) RepeatLarge/131072/4097-16 6.04GB/s ± 1% 6.09GB/s ± 3% ~ (p=0.356 n=9+10) RepeatLarge/262144/1-16 6.47GB/s ± 1% 6.63GB/s ± 2% +2.57% (p=0.003 n=10+10) RepeatLarge/262144/16-16 6.45GB/s ± 2% 6.69GB/s ± 2% +3.65% (p=0.000 n=10+10) RepeatLarge/262144/4097-16 6.35GB/s ± 1% 6.51GB/s ± 2% +2.48% (p=0.000 n=9+10) RepeatLarge/524288/1-16 6.21GB/s ± 2% 6.95GB/s ± 1% +11.95% (p=0.000 n=10+10) RepeatLarge/524288/16-16 6.24GB/s ± 2% 6.93GB/s ± 2% +11.11% (p=0.000 n=10+10) RepeatLarge/524288/4097-16 6.18GB/s ± 2% 6.82GB/s ± 1% +10.39% (p=0.000 n=9+10) RepeatLarge/1048576/1-16 5.34GB/s ± 2% 6.41GB/s ± 2% +20.05% (p=0.000 n=10+10) RepeatLarge/1048576/16-16 5.33GB/s ± 1% 6.45GB/s ± 2% +20.84% (p=0.000 n=10+9) RepeatLarge/1048576/4097-16 5.28GB/s ± 1% 6.17GB/s ± 2% +16.75% (p=0.000 n=10+10) RepeatLarge/2097152/1-16 4.04GB/s ± 1% 6.21GB/s ± 1% +53.89% (p=0.000 n=9+8) RepeatLarge/2097152/16-16 4.02GB/s ± 1% 6.20GB/s ± 2% +54.37% (p=0.000 n=10+9) RepeatLarge/2097152/4097-16 4.94GB/s ± 1% 6.04GB/s ± 1% +22.36% (p=0.000 n=10+10) RepeatLarge/4194304/1-16 3.10GB/s ± 1% 5.74GB/s ± 0% +85.04% (p=0.000 n=10+9) RepeatLarge/4194304/16-16 3.10GB/s ± 2% 5.72GB/s ± 1% +84.26% (p=0.000 n=9+10) RepeatLarge/4194304/4097-16 3.03GB/s ± 4% 5.61GB/s ± 1% +85.06% (p=0.000 n=10+9) RepeatLarge/8388608/1-16 3.08GB/s ± 2% 6.25GB/s ± 1% +103.09% (p=0.000 n=9+9) RepeatLarge/8388608/16-16 3.07GB/s ± 2% 6.26GB/s ± 3% +104.07% (p=0.000 n=10+9) RepeatLarge/8388608/4097-16 3.08GB/s ± 2% 6.23GB/s ± 2% +102.09% (p=0.000 n=9+10) RepeatLarge/16777216/1-16 3.25GB/s ± 2% 5.78GB/s ± 3% +78.03% (p=0.000 n=9+9) RepeatLarge/16777216/16-16 3.25GB/s ± 1% 5.75GB/s ± 1% +77.21% (p=0.000 n=9+10) RepeatLarge/16777216/4097-16 3.29GB/s ± 3% 5.72GB/s ± 2% +73.74% (p=0.000 n=10+10) RepeatLarge/33554432/1-16 3.68GB/s ± 2% 5.90GB/s ± 1% +60.20% (p=0.000 n=10+10) RepeatLarge/33554432/16-16 3.69GB/s ± 3% 5.88GB/s ± 1% +59.54% (p=0.000 n=10+9) RepeatLarge/33554432/4097-16 3.74GB/s ± 1% 5.94GB/s ± 2% +58.68% (p=0.000 n=7+10) RepeatLarge/67108864/1-16 4.62GB/s ±12% 6.11GB/s ± 3% +32.23% (p=0.000 n=10+9) RepeatLarge/67108864/16-16 4.77GB/s ± 2% 6.09GB/s ± 2% +27.88% (p=0.000 n=9+9) RepeatLarge/67108864/4097-16 4.78GB/s ± 1% 6.19GB/s ± 1% +29.51% (p=0.000 n=9+10) RepeatLarge/134217728/1-16 4.60GB/s ±16% 6.52GB/s ± 9% +41.67% (p=0.000 n=10+10) RepeatLarge/134217728/16-16 4.80GB/s ± 4% 6.81GB/s ± 2% +41.82% (p=0.000 n=10+9) RepeatLarge/134217728/4097-16 4.79GB/s ± 4% 6.81GB/s ± 2% +42.31% (p=0.000 n=9+10) RepeatLarge/268435456/1-16 4.43GB/s ±25% 6.27GB/s ±14% +41.52% (p=0.000 n=10+10) RepeatLarge/268435456/16-16 4.75GB/s ± 4% 6.68GB/s ± 4% +40.50% (p=0.000 n=9+10) RepeatLarge/268435456/4097-16 4.75GB/s ± 3% 6.58GB/s ± 4% +38.68% (p=0.000 n=9+10) RepeatLarge/536870912/1-16 4.96GB/s ± 9% 6.39GB/s ±16% +28.90% (p=0.000 n=8+10) RepeatLarge/536870912/16-16 4.66GB/s ± 6% 6.57GB/s ± 7% +40.82% (p=0.000 n=10+9) RepeatLarge/536870912/4097-16 4.68GB/s ±11% 6.88GB/s ± 3% +47.01% (p=0.000 n=10+9) RepeatLarge/1073741824/1-16 4.39GB/s ±23% 6.57GB/s ± 5% +49.75% (p=0.000 n=10+8) RepeatLarge/1073741824/16-16 4.73GB/s ±13% 6.89GB/s ± 1% +45.68% (p=0.000 n=9+8) RepeatLarge/1073741824/4097-16 4.97GB/s ±15% 6.73GB/s ± 9% +35.45% (p=0.000 n=10+10) The results above come from a Intel i9-9980HK (256KB L2) with TurboBoost disabled. Change-Id: I79dd57da0429aee9020ffd7bc458a034b999b740 Reviewed-on: https://go-review.googlesource.com/c/go/+/419054 Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> 
When generating long strings or slices with Repeat we
currently reuse intermediate states as a way to quickly
build exponentially longer results.

This works well as long as the intermediate states fit into
the processor D-cache. If they don't we start thrashing the
D-cache by reading in the whole intermediate state over and
over on each iteration.

Instead, once we reach a large enough intermediate state (that
allows the memcpy operation to perform at peak) we cap the
size of chunk of the state that is used as source for subsequent
appends. This ensures that this smaller source chunk is always
present in the D-cache, and the append operation does not need
to read the state contents from memory.

Currently the cap is set to 8KB, a number derived via
experimentation to yield the highest performance across a
a large range of result sizes. Slightly higher caps also
produced similar results: 8KB was chosen as the smallest one
in this performance plateau with the intention to minimize
D-cache pollution.

For result sizes larger than the fastest cache levels we get
significantly higher performance compared to the current
implementation:
strings:
name                            old speed      new speed      delta
RepeatLarge/256/1-16            1.73GB/s ± 1%  1.73GB/s ± 0%      ~     (p=0.556 n=5+4)
RepeatLarge/256/16-16           2.02GB/s ± 0%  1.95GB/s ± 8%      ~     (p=0.222 n=5+5)
RepeatLarge/512/1-16            2.30GB/s ±13%  2.47GB/s ± 1%      ~     (p=0.548 n=5+5)
RepeatLarge/512/16-16           2.38GB/s ±16%  2.77GB/s ± 1%   +16.27%  (p=0.032 n=5+5)
RepeatLarge/1024/1-16           3.17GB/s ± 1%  3.18GB/s ± 0%      ~     (p=0.730 n=4+5)
RepeatLarge/1024/16-16          3.39GB/s ± 2%  3.38GB/s ± 1%      ~     (p=0.548 n=5+5)
RepeatLarge/2048/1-16           3.32GB/s ± 2%  3.32GB/s ± 2%      ~     (p=1.000 n=5+5)
RepeatLarge/2048/16-16          3.41GB/s ± 4%  3.46GB/s ± 2%      ~     (p=0.310 n=5+5)
RepeatLarge/4096/1-16           3.60GB/s ± 4%  3.67GB/s ± 3%      ~     (p=0.690 n=5+5)
RepeatLarge/4096/16-16          3.74GB/s ± 3%  3.71GB/s ± 5%      ~     (p=0.690 n=5+5)
RepeatLarge/8192/1-16           3.94GB/s ± 4%  4.01GB/s ± 1%      ~     (p=0.222 n=5+5)
RepeatLarge/8192/16-16          3.94GB/s ± 6%  4.05GB/s ± 1%      ~     (p=0.222 n=5+5)
RepeatLarge/8192/4097-16        4.25GB/s ± 6%  4.32GB/s ± 3%      ~     (p=0.690 n=5+5)
RepeatLarge/16384/1-16          4.96GB/s ± 1%  5.02GB/s ± 2%      ~     (p=0.421 n=5+5)
RepeatLarge/16384/16-16         4.99GB/s ± 2%  5.07GB/s ± 1%      ~     (p=0.421 n=5+5)
RepeatLarge/16384/4097-16       5.15GB/s ± 3%  5.17GB/s ± 1%      ~     (p=1.000 n=5+5)
RepeatLarge/32768/1-16          5.44GB/s ± 2%  5.42GB/s ± 1%      ~     (p=0.841 n=5+5)
RepeatLarge/32768/16-16         5.46GB/s ± 4%  5.44GB/s ± 1%      ~     (p=0.905 n=5+4)
RepeatLarge/32768/4097-16       4.84GB/s ± 2%  4.59GB/s ±12%    -5.05%  (p=0.032 n=5+5)
RepeatLarge/65536/1-16          5.85GB/s ± 0%  5.84GB/s ± 1%      ~     (p=0.690 n=5+5)
RepeatLarge/65536/16-16         5.81GB/s ± 2%  5.84GB/s ± 2%      ~     (p=0.421 n=5+5)
RepeatLarge/65536/4097-16       5.38GB/s ± 6%  5.45GB/s ± 1%      ~     (p=1.000 n=5+5)
RepeatLarge/131072/1-16         6.20GB/s ± 1%  6.31GB/s ± 1%    +1.80%  (p=0.008 n=5+5)
RepeatLarge/131072/16-16        6.12GB/s ± 3%  6.25GB/s ± 3%      ~     (p=0.095 n=5+5)
RepeatLarge/131072/4097-16      5.95GB/s ± 1%  5.85GB/s ±10%      ~     (p=1.000 n=5+5)
RepeatLarge/262144/1-16         6.33GB/s ± 1%  6.56GB/s ± 0%    +3.62%  (p=0.016 n=5+4)
RepeatLarge/262144/16-16        6.42GB/s ± 0%  6.65GB/s ± 1%    +3.58%  (p=0.016 n=4+5)
RepeatLarge/262144/4097-16      6.31GB/s ± 1%  6.44GB/s ± 1%    +1.94%  (p=0.008 n=5+5)
RepeatLarge/524288/1-16         6.23GB/s ± 1%  6.92GB/s ± 3%   +11.02%  (p=0.008 n=5+5)
RepeatLarge/524288/16-16        6.24GB/s ± 1%  6.97GB/s ± 2%   +11.77%  (p=0.016 n=4+5)
RepeatLarge/524288/4097-16      6.14GB/s ± 2%  6.73GB/s ± 3%    +9.50%  (p=0.008 n=5+5)
RepeatLarge/1048576/1-16        5.23GB/s ± 1%  6.53GB/s ± 6%   +24.85%  (p=0.008 n=5+5)
RepeatLarge/1048576/16-16       5.21GB/s ± 1%  6.56GB/s ± 4%   +25.93%  (p=0.008 n=5+5)
RepeatLarge/1048576/4097-16     5.22GB/s ± 1%  6.26GB/s ± 2%   +20.09%  (p=0.008 n=5+5)
RepeatLarge/2097152/1-16        3.95GB/s ± 1%  5.96GB/s ± 1%   +51.01%  (p=0.008 n=5+5)
RepeatLarge/2097152/16-16       3.94GB/s ± 1%  5.98GB/s ± 2%   +51.99%  (p=0.008 n=5+5)
RepeatLarge/2097152/4097-16     4.94GB/s ± 1%  5.71GB/s ± 2%   +15.63%  (p=0.008 n=5+5)
RepeatLarge/4194304/1-16        3.10GB/s ± 1%  5.89GB/s ± 1%   +89.90%  (p=0.008 n=5+5)
RepeatLarge/4194304/16-16       3.09GB/s ± 1%  5.86GB/s ± 1%   +89.89%  (p=0.008 n=5+5)
RepeatLarge/4194304/4097-16     3.13GB/s ± 1%  5.89GB/s ± 1%   +88.36%  (p=0.008 n=5+5)
RepeatLarge/8388608/1-16        3.06GB/s ± 1%  6.31GB/s ±16%  +105.84%  (p=0.008 n=5+5)
RepeatLarge/8388608/16-16       3.08GB/s ± 1%  6.62GB/s ± 1%  +114.66%  (p=0.008 n=5+5)
RepeatLarge/8388608/4097-16     3.13GB/s ± 2%  6.87GB/s ± 1%  +119.62%  (p=0.008 n=5+5)
RepeatLarge/16777216/1-16       3.21GB/s ± 3%  5.88GB/s ± 1%   +83.27%  (p=0.008 n=5+5)
RepeatLarge/16777216/16-16      3.23GB/s ± 2%  5.84GB/s ± 2%   +80.49%  (p=0.008 n=5+5)
RepeatLarge/16777216/4097-16    3.30GB/s ± 6%  5.88GB/s ± 2%   +78.18%  (p=0.008 n=5+5)
RepeatLarge/33554432/1-16       3.71GB/s ± 3%  5.91GB/s ± 2%   +59.17%  (p=0.008 n=5+5)
RepeatLarge/33554432/16-16      3.67GB/s ± 3%  5.91GB/s ± 2%   +61.13%  (p=0.008 n=5+5)
RepeatLarge/33554432/4097-16    3.71GB/s ± 1%  5.77GB/s ± 6%   +55.51%  (p=0.008 n=5+5)
RepeatLarge/67108864/1-16       4.61GB/s ±11%  6.00GB/s ± 5%   +30.15%  (p=0.008 n=5+5)
RepeatLarge/67108864/16-16      4.62GB/s ± 7%  6.11GB/s ± 2%   +32.35%  (p=0.008 n=5+5)
RepeatLarge/67108864/4097-16    4.71GB/s ± 2%  6.24GB/s ± 2%   +32.60%  (p=0.008 n=5+5)
RepeatLarge/134217728/1-16      4.53GB/s ± 8%  6.28GB/s ±11%   +38.57%  (p=0.008 n=5+5)
RepeatLarge/134217728/16-16     4.78GB/s ± 3%  6.36GB/s ± 3%   +33.16%  (p=0.008 n=5+5)
RepeatLarge/134217728/4097-16   4.73GB/s ± 6%  6.46GB/s ± 3%   +36.63%  (p=0.008 n=5+5)
RepeatLarge/268435456/1-16      4.09GB/s ±25%  6.37GB/s ±19%   +56.00%  (p=0.008 n=5+5)
RepeatLarge/268435456/16-16     4.50GB/s ± 4%  6.86GB/s ± 0%   +52.49%  (p=0.016 n=5+4)
RepeatLarge/268435456/4097-16   4.73GB/s ± 5%  6.90GB/s ± 0%   +45.94%  (p=0.008 n=5+5)
RepeatLarge/536870912/1-16      4.38GB/s ±36%  6.52GB/s ± 8%   +48.68%  (p=0.008 n=5+5)
RepeatLarge/536870912/16-16     4.69GB/s ±12%  6.90GB/s ± 1%   +46.97%  (p=0.008 n=5+5)
RepeatLarge/536870912/4097-16   4.87GB/s ± 8%  6.98GB/s ± 0%   +43.36%  (p=0.008 n=5+5)
RepeatLarge/1073741824/1-16     3.87GB/s ±28%  6.96GB/s ± 1%   +79.94%  (p=0.016 n=5+4)
RepeatLarge/1073741824/16-16    4.79GB/s ± 9%  6.93GB/s ± 0%   +44.79%  (p=0.008 n=5+5)
RepeatLarge/1073741824/4097-16  4.65GB/s ± 8%  7.02GB/s ± 1%   +51.02%  (p=0.008 n=5+5)

bytes:
name                            old speed      new speed      delta
RepeatLarge/256/1-16            1.93GB/s ± 1%  1.84GB/s ± 1%    -4.81%  (p=0.000 n=10+10)
RepeatLarge/256/16-16           2.25GB/s ± 2%  2.15GB/s ± 1%    -4.45%  (p=0.000 n=9+8)
RepeatLarge/512/1-16            2.71GB/s ± 1%  2.62GB/s ± 1%    -3.27%  (p=0.000 n=10+9)
RepeatLarge/512/16-16           2.96GB/s ± 4%  2.91GB/s ± 1%      ~     (p=0.243 n=9+10)
RepeatLarge/1024/1-16           3.35GB/s ± 1%  3.27GB/s ± 1%    -2.61%  (p=0.000 n=9+10)
RepeatLarge/1024/16-16          3.56GB/s ± 2%  3.52GB/s ± 1%    -1.10%  (p=0.010 n=10+9)
RepeatLarge/2048/1-16           3.52GB/s ± 1%  3.45GB/s ± 1%    -1.92%  (p=0.000 n=10+10)
RepeatLarge/2048/16-16          3.61GB/s ± 1%  3.58GB/s ± 0%    -0.82%  (p=0.008 n=9+8)
RepeatLarge/4096/1-16           3.85GB/s ± 2%  3.80GB/s ± 2%      ~     (p=0.165 n=10+10)
RepeatLarge/4096/16-16          3.88GB/s ± 3%  3.84GB/s ± 4%      ~     (p=0.393 n=10+10)
RepeatLarge/8192/1-16           4.12GB/s ± 2%  4.04GB/s ± 1%    -1.96%  (p=0.000 n=10+10)
RepeatLarge/8192/16-16          4.11GB/s ± 2%  4.09GB/s ± 1%      ~     (p=0.278 n=9+10)
RepeatLarge/8192/4097-16        4.38GB/s ± 1%  4.39GB/s ± 4%      ~     (p=0.720 n=9+10)
RepeatLarge/16384/1-16          5.06GB/s ± 2%  4.95GB/s ± 3%    -2.29%  (p=0.001 n=10+9)
RepeatLarge/16384/16-16         5.11GB/s ± 3%  5.06GB/s ± 3%      ~     (p=0.315 n=10+9)
RepeatLarge/16384/4097-16       5.22GB/s ± 3%  5.26GB/s ± 3%      ~     (p=0.211 n=9+10)
RepeatLarge/32768/1-16          5.54GB/s ± 2%  5.50GB/s ± 3%      ~     (p=0.353 n=10+10)
RepeatLarge/32768/16-16         5.55GB/s ± 1%  5.60GB/s ± 1%    +0.91%  (p=0.035 n=10+9)
RepeatLarge/32768/4097-16       4.88GB/s ± 2%  4.85GB/s ± 2%      ~     (p=0.447 n=10+9)
RepeatLarge/65536/1-16          5.86GB/s ± 1%  5.93GB/s ± 2%    +1.18%  (p=0.043 n=8+10)
RepeatLarge/65536/16-16         5.83GB/s ± 2%  5.98GB/s ± 1%    +2.67%  (p=0.000 n=10+10)
RepeatLarge/65536/4097-16       5.57GB/s ± 0%  5.56GB/s ± 3%      ~     (p=0.696 n=8+10)
RepeatLarge/131072/1-16         6.23GB/s ± 1%  6.38GB/s ± 2%    +2.51%  (p=0.000 n=9+10)
RepeatLarge/131072/16-16        6.21GB/s ± 2%  6.37GB/s ± 1%    +2.72%  (p=0.000 n=9+10)
RepeatLarge/131072/4097-16      6.04GB/s ± 1%  6.09GB/s ± 3%      ~     (p=0.356 n=9+10)
RepeatLarge/262144/1-16         6.47GB/s ± 1%  6.63GB/s ± 2%    +2.57%  (p=0.003 n=10+10)
RepeatLarge/262144/16-16        6.45GB/s ± 2%  6.69GB/s ± 2%    +3.65%  (p=0.000 n=10+10)
RepeatLarge/262144/4097-16      6.35GB/s ± 1%  6.51GB/s ± 2%    +2.48%  (p=0.000 n=9+10)
RepeatLarge/524288/1-16         6.21GB/s ± 2%  6.95GB/s ± 1%   +11.95%  (p=0.000 n=10+10)
RepeatLarge/524288/16-16        6.24GB/s ± 2%  6.93GB/s ± 2%   +11.11%  (p=0.000 n=10+10)
RepeatLarge/524288/4097-16      6.18GB/s ± 2%  6.82GB/s ± 1%   +10.39%  (p=0.000 n=9+10)
RepeatLarge/1048576/1-16        5.34GB/s ± 2%  6.41GB/s ± 2%   +20.05%  (p=0.000 n=10+10)
RepeatLarge/1048576/16-16       5.33GB/s ± 1%  6.45GB/s ± 2%   +20.84%  (p=0.000 n=10+9)
RepeatLarge/1048576/4097-16     5.28GB/s ± 1%  6.17GB/s ± 2%   +16.75%  (p=0.000 n=10+10)
RepeatLarge/2097152/1-16        4.04GB/s ± 1%  6.21GB/s ± 1%   +53.89%  (p=0.000 n=9+8)
RepeatLarge/2097152/16-16       4.02GB/s ± 1%  6.20GB/s ± 2%   +54.37%  (p=0.000 n=10+9)
RepeatLarge/2097152/4097-16     4.94GB/s ± 1%  6.04GB/s ± 1%   +22.36%  (p=0.000 n=10+10)
RepeatLarge/4194304/1-16        3.10GB/s ± 1%  5.74GB/s ± 0%   +85.04%  (p=0.000 n=10+9)
RepeatLarge/4194304/16-16       3.10GB/s ± 2%  5.72GB/s ± 1%   +84.26%  (p=0.000 n=9+10)
RepeatLarge/4194304/4097-16     3.03GB/s ± 4%  5.61GB/s ± 1%   +85.06%  (p=0.000 n=10+9)
RepeatLarge/8388608/1-16        3.08GB/s ± 2%  6.25GB/s ± 1%  +103.09%  (p=0.000 n=9+9)
RepeatLarge/8388608/16-16       3.07GB/s ± 2%  6.26GB/s ± 3%  +104.07%  (p=0.000 n=10+9)
RepeatLarge/8388608/4097-16     3.08GB/s ± 2%  6.23GB/s ± 2%  +102.09%  (p=0.000 n=9+10)
RepeatLarge/16777216/1-16       3.25GB/s ± 2%  5.78GB/s ± 3%   +78.03%  (p=0.000 n=9+9)
RepeatLarge/16777216/16-16      3.25GB/s ± 1%  5.75GB/s ± 1%   +77.21%  (p=0.000 n=9+10)
RepeatLarge/16777216/4097-16    3.29GB/s ± 3%  5.72GB/s ± 2%   +73.74%  (p=0.000 n=10+10)
RepeatLarge/33554432/1-16       3.68GB/s ± 2%  5.90GB/s ± 1%   +60.20%  (p=0.000 n=10+10)
RepeatLarge/33554432/16-16      3.69GB/s ± 3%  5.88GB/s ± 1%   +59.54%  (p=0.000 n=10+9)
RepeatLarge/33554432/4097-16    3.74GB/s ± 1%  5.94GB/s ± 2%   +58.68%  (p=0.000 n=7+10)
RepeatLarge/67108864/1-16       4.62GB/s ±12%  6.11GB/s ± 3%   +32.23%  (p=0.000 n=10+9)
RepeatLarge/67108864/16-16      4.77GB/s ± 2%  6.09GB/s ± 2%   +27.88%  (p=0.000 n=9+9)
RepeatLarge/67108864/4097-16    4.78GB/s ± 1%  6.19GB/s ± 1%   +29.51%  (p=0.000 n=9+10)
RepeatLarge/134217728/1-16      4.60GB/s ±16%  6.52GB/s ± 9%   +41.67%  (p=0.000 n=10+10)
RepeatLarge/134217728/16-16     4.80GB/s ± 4%  6.81GB/s ± 2%   +41.82%  (p=0.000 n=10+9)
RepeatLarge/134217728/4097-16   4.79GB/s ± 4%  6.81GB/s ± 2%   +42.31%  (p=0.000 n=9+10)
RepeatLarge/268435456/1-16      4.43GB/s ±25%  6.27GB/s ±14%   +41.52%  (p=0.000 n=10+10)
RepeatLarge/268435456/16-16     4.75GB/s ± 4%  6.68GB/s ± 4%   +40.50%  (p=0.000 n=9+10)
RepeatLarge/268435456/4097-16   4.75GB/s ± 3%  6.58GB/s ± 4%   +38.68%  (p=0.000 n=9+10)
RepeatLarge/536870912/1-16      4.96GB/s ± 9%  6.39GB/s ±16%   +28.90%  (p=0.000 n=8+10)
RepeatLarge/536870912/16-16     4.66GB/s ± 6%  6.57GB/s ± 7%   +40.82%  (p=0.000 n=10+9)
RepeatLarge/536870912/4097-16   4.68GB/s ±11%  6.88GB/s ± 3%   +47.01%  (p=0.000 n=10+9)
RepeatLarge/1073741824/1-16     4.39GB/s ±23%  6.57GB/s ± 5%   +49.75%  (p=0.000 n=10+8)
RepeatLarge/1073741824/16-16    4.73GB/s ±13%  6.89GB/s ± 1%   +45.68%  (p=0.000 n=9+8)
RepeatLarge/1073741824/4097-16  4.97GB/s ±15%  6.73GB/s ± 9%   +35.45%  (p=0.000 n=10+10)

The results above come from a Intel i9-9980HK (256KB L2) with
TurboBoost disabled.

Change-Id: I79dd57da0429aee9020ffd7bc458a034b999b740
Reviewed-on: https://go-review.googlesource.com/c/go/+/419054
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
bytes, strings: add ASCII fast path to EqualFold 2022-09-21T14:00:37+00:00 Charlie Vieth charlie.vieth@gmail.com 2022-08-24T18:23:28+00:00 c70fd4b30aba5db2df7b5f6b0833c62b909f50eb This commit adds an ASCII fast path to bytes/strings EqualFold that roughly doubles performance when all characters are ASCII. It also changes strings.EqualFold to use `for range` for the first string since this is ~10% faster than using utf8.DecodeRuneInString for both (see #31666). Performance (similar results on arm64 and amd64): name old time/op new time/op delta EqualFold/Tests-10 238ns ± 0% 172ns ± 1% -27.91% (p=0.000 n=10+10) EqualFold/ASCII-10 20.5ns ± 0% 9.7ns ± 0% -52.73% (p=0.000 n=10+10) EqualFold/UnicodePrefix-10 86.5ns ± 0% 77.6ns ± 0% -10.37% (p=0.000 n=10+10) EqualFold/UnicodeSuffix-10 86.8ns ± 2% 71.3ns ± 0% -17.88% (p=0.000 n=10+8) Change-Id: I058f3f97a08dc04d65af895674d85420f920abe1 Reviewed-on: https://go-review.googlesource.com/c/go/+/425459 Reviewed-by: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> 
This commit adds an ASCII fast path to bytes/strings EqualFold that
roughly doubles performance when all characters are ASCII.

It also changes strings.EqualFold to use `for range` for the first
string since this is ~10% faster than using utf8.DecodeRuneInString for
both (see #31666).

Performance (similar results on arm64 and amd64):

name                        old time/op  new time/op  delta
EqualFold/Tests-10           238ns ± 0%   172ns ± 1%  -27.91%  (p=0.000 n=10+10)
EqualFold/ASCII-10          20.5ns ± 0%   9.7ns ± 0%  -52.73%  (p=0.000 n=10+10)
EqualFold/UnicodePrefix-10  86.5ns ± 0%  77.6ns ± 0%  -10.37%  (p=0.000 n=10+10)
EqualFold/UnicodeSuffix-10  86.8ns ± 2%  71.3ns ± 0%  -17.88%  (p=0.000 n=10+8)

Change-Id: I058f3f97a08dc04d65af895674d85420f920abe1
Reviewed-on: https://go-review.googlesource.com/c/go/+/425459
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
strings: reuse the input string for Repeat count of 1 2022-09-14T14:56:07+00:00 Anuraag Agrawal anuraaga@gmail.com 2022-06-10T05:41:02+00:00 9503bcae2b20d290332d00d78672881b7fcfedf0 The existing implementation allocates a new string even when the count is 1, where we know the output is the same as the input. While we wouldn't expect a count of 1 for hardcoded values of the parameter, it is expected when the parameter is computed based on a different value (e.g., the length of a input slice). name old time/op new time/op delta Repeat/5x0-10 2.03ns ± 0% 2.02ns ± 0% ~ (p=1.000 n=1+1) Repeat/5x1-10 13.7ns ± 0% 2.0ns ± 0% ~ (p=1.000 n=1+1) Repeat/5x2-10 18.2ns ± 0% 18.1ns ± 0% ~ (p=1.000 n=1+1) Repeat/5x6-10 27.0ns ± 0% 27.0ns ± 0% ~ (p=1.000 n=1+1) Repeat/10x0-10 2.02ns ± 0% 2.02ns ± 0% ~ (p=1.000 n=1+1) Repeat/10x1-10 16.1ns ± 0% 2.0ns ± 0% ~ (p=1.000 n=1+1) Repeat/10x2-10 20.8ns ± 0% 20.9ns ± 0% ~ (p=1.000 n=1+1) Repeat/10x6-10 29.2ns ± 0% 29.4ns ± 0% ~ (p=1.000 n=1+1) Change-Id: I48e08e08f8f6d6914d62b3d6a61d563d637bec59 GitHub-Last-Rev: 068f58e08b8f5c4105e7a210f242ca1ff3a61177 GitHub-Pull-Request: golang/go#53321 Reviewed-on: https://go-review.googlesource.com/c/go/+/411477 Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Keith Randall <khr@google.com> 
The existing implementation allocates a new string even when the
count is 1, where we know the output is the same as the input.
While we wouldn't expect a count of 1 for hardcoded values of the
parameter, it is expected when the parameter is computed based on
a different value (e.g., the length of a input slice).

name            old time/op  new time/op  delta
Repeat/5x0-10   2.03ns ± 0%  2.02ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/5x1-10   13.7ns ± 0%   2.0ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/5x2-10   18.2ns ± 0%  18.1ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/5x6-10   27.0ns ± 0%  27.0ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/10x0-10  2.02ns ± 0%  2.02ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/10x1-10  16.1ns ± 0%   2.0ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/10x2-10  20.8ns ± 0%  20.9ns ± 0%   ~     (p=1.000 n=1+1)
Repeat/10x6-10  29.2ns ± 0%  29.4ns ± 0%   ~     (p=1.000 n=1+1)

Change-Id: I48e08e08f8f6d6914d62b3d6a61d563d637bec59
GitHub-Last-Rev: 068f58e08b8f5c4105e7a210f242ca1ff3a61177
GitHub-Pull-Request: golang/go#53321
Reviewed-on: https://go-review.googlesource.com/c/go/+/411477
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>