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Author SHA1 Message Date
go101 44b54b99c9 strings,bytes: improve Repeat panic messages
The Repeat("-", maxInt) call should produce

   panic: runtime error: makeslice: len out of range

instead of

   panic: strings: Repeat output length overflow

This PR is only for theory perfection.

Change-Id: If67d87b147d666fbbb7238656f2a0cb6cf1dbb5b
GitHub-Last-Rev: 29dc0cb9c9
GitHub-Pull-Request: golang/go#67068
Reviewed-on: https://go-review.googlesource.com/c/go/+/581936
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2024-05-03 12:58:37 +00:00
Mateusz Poliwczak 968b71bce4 strings: make use of sizeclasses in (*Builder).Grow
Fixes #64833

Change-Id: Ice3f5dfab65f5525bc7a6f57ddeaabda8d64dfa3
GitHub-Last-Rev: 38f1d6c19d
GitHub-Pull-Request: golang/go#64835
Reviewed-on: https://go-review.googlesource.com/c/go/+/552135
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-02-19 19:51:15 +00:00
Jes Cok a05a25cb19 bytes,internal/bytealg: add func bytealg.LastIndexRabinKarp
Also rename 'substr' to 'sep' in IndexRabinKarp for consistency.

Change-Id: Icc2ad1116aecaf002c8264daa2fa608306c9a88a
GitHub-Last-Rev: 1784b93f53
GitHub-Pull-Request: golang/go#63854
Reviewed-on: https://go-review.googlesource.com/c/go/+/538716
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2023-11-01 19:02:57 +00:00
Jes Cok 68e52bc03c bytes,internal/bytealg: eliminate IndexRabinKarpBytes using generics
This is a follow-up to CL 538175.

Change-Id: Iec2523b36a16d7e157c17858c89fcd43c2470d58
GitHub-Last-Rev: 812d36e57c
GitHub-Pull-Request: golang/go#63770
Reviewed-on: https://go-review.googlesource.com/c/go/+/538195
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
2023-10-31 17:14:04 +00:00
Jes Cok b46aec0765 bytes,internal/bytealg: eliminate HashStrBytes,HashStrRevBytes using …
…generics

The logic of HashStrBytes, HashStrRevBytes and HashStr, HashStrRev,
are exactly the same, except that the types are different.

Since the bootstrap toolchain is bumped to 1.20, we can eliminate them
by using generics.

Change-Id: I4336b1cab494ba963f09646c169b45f6b1ee62e3
GitHub-Last-Rev: b11a2bf947
GitHub-Pull-Request: golang/go#63766
Reviewed-on: https://go-review.googlesource.com/c/go/+/538175
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-10-27 15:55:16 +00:00
Matthew Dempsky 62fb281cf7 bytes, strings: use "reports whether" in HasPrefix and HasSuffix
Update the doc comments to use the more idiomatic and common phrase
"reports whether" instead of "tests whether".

Change-Id: I2b7f8cce2d192f66e296ebaa9b37f37e8276b4ae
Reviewed-on: https://go-review.googlesource.com/c/go/+/524898
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-09-01 04:29:02 +00:00
Tobias Klauser 890a62bf1b internal/bytealg: add generic LastIndexByte{,String}
To avoid duplicating them in net/netip and os and to allow these
packages automatically benefiting from future performance improvements
when optimized native LastIndexByte{,String} implementations are added.

For #36891

Change-Id: I4905a4742273570c2c36b867df57762c5bfbe1e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/522475
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-08-25 15:08:28 +00:00
Daniel Martí 9768f736ea all: add a few links in package godocs
I noticed the one in path/filepath while reading the docs,
and the other ones were found via some quick grepping.

Change-Id: I386f2f74ef816a6d18aa2f58ee6b64dbd0147c9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/478795
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-03-25 10:16:23 +00:00
Joe Tsai 132fae93b7 bytes, strings: avoid unnecessary zero initialization
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>
2023-02-27 19:11:00 +00:00
hopehook 0b3f58c48e bytes, strings: add ContainsFunc
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>
2023-01-24 22:06:45 +00:00
Carlo Alberto Ferraris dcb90152a4 bytes,strings: optimize Repeat
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>
2022-09-27 16:55:15 +00:00
Charlie Vieth c70fd4b30a bytes, strings: add ASCII fast path to EqualFold
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>
2022-09-21 14:00:37 +00:00
Joe Tsai 70de482d17 bytes: rely on utf8.AppendRune
This is both simpler and more performant.

WriteRune                                 23.9µs ± 1%   22.8µs ± 8%   -4.43%  (p=0.006 n=8+10)
ToUpper/longɐstringɐwithɐnonasciiⱯchars    573ns ± 4%    474ns ± 6%  -17.27%  (p=0.000 n=10+10)
ToUpper/ɐɐɐɐɐ                              236ns ± 6%    202ns ± 5%  -14.12%  (p=0.000 n=10+10)
ToUpper/a\u0080\U0010ffff                 98.8ns ± 6%   91.2ns ± 3%   -7.67%  (p=0.000 n=10+10)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS    511ns ± 3%    409ns ± 4%  -20.02%  (p=0.000 n=10+10)
ToLower/ⱭⱭⱭⱭⱭ                              178ns ± 4%    173ns ± 2%   -2.76%  (p=0.005 n=10+10)
ToLower/A\u0080\U0010ffff                  100ns ± 3%     91ns ± 2%   -8.55%  (p=0.000 n=10+10)

Change-Id: I968ef194da2c115cbdcac2d3575c34c65e6a8a56
Reviewed-on: https://go-review.googlesource.com/c/go/+/412337
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
2022-08-23 20:26:47 +00:00
Michal Bohuslávek 5f0170f9a5 bytes, strings: s/after/before/ in CutSuffix
This follows on CL 407176 which added this function (in both
packages). This CL makes it consistent with the Cut function,
which uses “before” and “after” in return variable names.

Change-Id: Id4345d2fe0f50bf301a880803e87bf356986b518
Reviewed-on: https://go-review.googlesource.com/c/go/+/424922
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
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Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-08-19 20:56:43 +00:00
Changkun Ou 68005592b3 strings, bytes: add CutPrefix and CutSuffix
Fixes #42537

Change-Id: Ie03c2614ffee30ebe707acad6b9f6c28fb134a45
Reviewed-on: https://go-review.googlesource.com/c/go/+/407176
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Changkun Ou <mail@changkun.de>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-08-16 19:48:39 +00:00
Martin Möhrmann 7b45edb450 bytes: add Clone function
The new Clone function returns a copy of b[:len(b)]
for the input byte slice b.
The result may have additional unused capacity.
Clone(nil) returns nil.

Fixes #45038

Change-Id: I0469a202d77a7b491f1341c08915d07ddd1f0300
Reviewed-on: https://go-review.googlesource.com/c/go/+/359675
Run-TryBot: Martin Möhrmann <martin@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-08-15 19:17:20 +00:00
Philippe Antoine 5e4543c29f bytes: explode checks for n too large
As is already done in strings package.

Change-Id: Ia45e6443ddf6beac5e70a1cc493119030e173139
GitHub-Last-Rev: 1174c25035
GitHub-Pull-Request: golang/go#52348
Reviewed-on: https://go-review.googlesource.com/c/go/+/400239
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2022-04-16 02:01:19 +00:00
Russ Cox 19309779ac all: gofmt main repo
[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-11 16:34:30 +00:00
hopehook c451a02a6d strings, bytes: improve the description of simple case-folding in EqualFold
This CL removes the problem description pointed out by @bjkail.
Second, synchronously modify the comments of the bytes package.

Updates #52022
Fixes #52204

Change-Id: I0aa52c774f40bb91f32bebdd2a62a11067a77be0
Reviewed-on: https://go-review.googlesource.com/c/go/+/398736
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
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Trust: Cherry Mui <cherryyz@google.com>
2022-04-07 23:06:24 +00:00
Philippe Antoine 5bb2628c6f bytes: limit allocation in SplitN
So that bytes.SplitN("", "T", int(144115188075855872)) does not panic.

Change-Id: I7c068852bd708416164fc2ed8b84cf6b2d593666
GitHub-Last-Rev: f8df09d65e
GitHub-Pull-Request: golang/go#52147
Reviewed-on: https://go-review.googlesource.com/c/go/+/398076
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: mzh <mzh@golangcn.org>
2022-04-06 03:13:34 +00:00
Ian Lance Taylor 32fdad19a2 bytes: restore old Trim/TrimLeft behavior for nil
Keep returning nil for the cases where we historically returned nil,
even though this is slightly different for TrimLeft and TrimRight.

Fixes #51793

Change-Id: Ifbdfc6b09d52b8e063cfe6341019f9b2eb8b70e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/393876
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Keith Randall <khr@golang.org>
2022-03-28 22:06:49 +00:00
Ian Lance Taylor 540632841e bytes, strings: mention Cut in docs for Split and SplitN
For #46336

Change-Id: Idc23302085e14e24d571f5995d6d33ca964a0021
Reviewed-on: https://go-review.googlesource.com/c/go/+/382954
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2022-02-08 22:25:54 +00:00
smasher164 7aed6dd7e1 strings, bytes: deprecate Title
Title doesn't handle Unicode punctuation and language-specific
capitalization rules. Replace the BUG comment with a Deprecated
one, suggesting a more robust alternative, and allowing Title
to be exposed to tooling.

Fixes #48367.

Change-Id: I952f1f37cd35b587a95893fb022827bdd9ec7de9
Reviewed-on: https://go-review.googlesource.com/c/go/+/359485
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Mui <cherryyz@google.com>
2021-11-05 21:27:34 +00:00
Brad Fitzpatrick a59e33224e net/netip: add new IP address package
Co-authored-by: Alex Willmer <alex@moreati.org.uk> (GitHub @moreati)
Co-authored-by: Alexander Yastrebov <yastrebov.alex@gmail.com>
Co-authored-by: David Anderson <dave@natulte.net> (Tailscale CLA)
Co-authored-by: David Crawshaw <crawshaw@tailscale.com> (Tailscale CLA)
Co-authored-by: Dmytro Shynkevych <dmytro@tailscale.com> (Tailscale CLA)
Co-authored-by: Elias Naur <mail@eliasnaur.com>
Co-authored-by: Joe Tsai <joetsai@digital-static.net> (Tailscale CLA)
Co-authored-by: Jonathan Yu <jawnsy@cpan.org> (GitHub @jawnsy)
Co-authored-by: Josh Bleecher Snyder <josharian@gmail.com> (Tailscale CLA)
Co-authored-by: Maisem Ali <maisem@tailscale.com> (Tailscale CLA)
Co-authored-by: Manuel Mendez (Go AUTHORS mmendez534@...)
Co-authored-by: Matt Layher <mdlayher@gmail.com>
Co-authored-by: Noah Treuhaft <noah.treuhaft@gmail.com> (GitHub @nwt)
Co-authored-by: Stefan Majer <stefan.majer@gmail.com>
Co-authored-by: Terin Stock <terinjokes@gmail.com> (Cloudflare CLA)
Co-authored-by: Tobias Klauser <tklauser@distanz.ch>

Fixes #46518

Change-Id: I0041f9e1115d61fa6e95fcf32b01d9faee708712
Reviewed-on: https://go-review.googlesource.com/c/go/+/339309
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
2021-11-02 01:28:01 +00:00
Alexander Melentyev 3fa9ee49a0 bytes: remove redundant type conversion
Change-Id: Icafb2d9fd11b23d3acaf9df07e7f90d8bcd829fa
GitHub-Last-Rev: 2b76646055
GitHub-Pull-Request: golang/go#49243
Reviewed-on: https://go-review.googlesource.com/c/go/+/360096
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
Trust: Martin Möhrmann <martin@golang.org>
2021-10-31 17:52:41 +00:00
kjgorman 3986e5c8e7 bytes: fix Cut godoc typo
If sep does not appear in s, we return nil here
rather than the empty string. Presumably the docs
were copied from the  strings package implementation
and brought that along.

Change-Id: I3706c94fe04abd9e2a2c8840f7cc6116386965c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/354969
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Alexander Rakoczy <alex@golang.org>
2021-10-13 16:39:23 +00:00
Carlo Alberto Ferraris 4002616f9a strings,bytes: avoid allocations in Trim/TrimLeft/TrimRight
There is evidence that the vast majority of uses for Trim* involve
cutsets with a single ASCII character, and the vast majority of
remaining uses involve cutsets with a small (<4) ASCII characters.
For this reason it makes sense to provide better fast paths for these
common cases.

Furthermore the current implementation needlessly allocates for unclear
benefits. This CL also replaces all paths to avoid allocations and, as
a side effect, it speeds up also the slow path.

strings:
name                    old time/op    new time/op    delta
Trim                      1.71µs ± 1%    0.70µs ± 0%   -58.93%  (p=0.008 n=5+5)
TrimASCII/1:1             6.43ns ± 0%    6.34ns ± 0%    -1.41%  (p=0.008 n=5+5)
TrimASCII/1:2             97.3ns ± 0%    18.2ns ± 1%   -81.34%  (p=0.008 n=5+5)
TrimASCII/1:4              101ns ± 0%      21ns ± 0%   -78.77%  (p=0.008 n=5+5)
TrimASCII/1:8              109ns ± 0%      29ns ± 0%   -73.60%  (p=0.008 n=5+5)
TrimASCII/1:16             124ns ± 0%      43ns ± 0%   -65.16%  (p=0.008 n=5+5)
TrimASCII/16:1            19.8ns ± 0%    18.6ns ± 0%    -5.90%  (p=0.008 n=5+5)
TrimASCII/16:2             167ns ± 0%      33ns ± 0%   -80.21%  (p=0.008 n=5+5)
TrimASCII/16:4             169ns ± 0%      35ns ± 0%   -79.01%  (p=0.008 n=5+5)
TrimASCII/16:8             177ns ± 0%      43ns ± 0%   -75.88%  (p=0.008 n=5+5)
TrimASCII/16:16            193ns ± 2%      57ns ± 1%   -70.30%  (p=0.008 n=5+5)
TrimASCII/256:1            232ns ± 0%     232ns ± 0%      ~     (p=1.000 n=5+5)
TrimASCII/256:2           1.28µs ± 1%    0.26µs ± 0%   -79.46%  (p=0.008 n=5+5)
TrimASCII/256:4           1.27µs ± 0%    0.27µs ± 0%   -78.95%  (p=0.008 n=5+5)
TrimASCII/256:8           1.28µs ± 0%    0.28µs ± 1%   -78.28%  (p=0.008 n=5+5)
TrimASCII/256:16          1.30µs ± 1%    0.29µs ± 0%   -77.49%  (p=0.008 n=5+5)
TrimASCII/4096:1          3.47µs ± 0%    3.47µs ± 0%    -0.14%  (p=0.008 n=5+5)
TrimASCII/4096:2          18.2µs ± 0%     3.9µs ± 0%   -78.53%  (p=0.008 n=5+5)
TrimASCII/4096:4          18.2µs ± 0%     3.9µs ± 0%   -78.55%  (p=0.008 n=5+5)
TrimASCII/4096:8          18.2µs ± 0%     3.9µs ± 0%   -78.49%  (p=0.008 n=5+5)
TrimASCII/4096:16         18.3µs ± 0%     3.9µs ± 0%   -78.44%  (p=0.008 n=5+5)
TrimByte                  10.6ns ± 1%    10.1ns ± 0%    -5.01%  (p=0.008 n=5+5)
TrimSpace/NoTrim          5.90ns ± 0%    5.89ns ± 0%      ~     (p=0.135 n=5+5)
TrimSpace/ASCII           10.6ns ± 0%     9.9ns ± 0%    -6.21%  (p=0.008 n=5+5)
TrimSpace/SomeNonASCII     127ns ± 0%     126ns ± 0%    -0.96%  (p=0.008 n=5+5)
TrimSpace/JustNonASCII     178ns ± 0%     178ns ± 0%      ~     (p=0.825 n=5+4)

name                    old alloc/op   new alloc/op   delta
Trim                        456B ± 0%        0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:1              0.00B          0.00B           ~     (all equal)
TrimASCII/1:2              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:4              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:8              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:16             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:1             0.00B          0.00B           ~     (all equal)
TrimASCII/16:2             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:4             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:8             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:16            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:1            0.00B          0.00B           ~     (all equal)
TrimASCII/256:2            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:4            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:8            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:16           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:1           0.00B          0.00B           ~     (all equal)
TrimASCII/4096:2           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:4           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:8           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:16          48.0B ± 0%      0.0B           ~     (p=0.079 n=4+5)
TrimByte                   0.00B          0.00B           ~     (all equal)
TrimSpace/NoTrim           0.00B          0.00B           ~     (all equal)
TrimSpace/ASCII            0.00B          0.00B           ~     (all equal)
TrimSpace/SomeNonASCII     0.00B          0.00B           ~     (all equal)
TrimSpace/JustNonASCII     0.00B          0.00B           ~     (all equal)

name                    old allocs/op  new allocs/op  delta
Trim                        18.0 ± 0%       0.0       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:1               0.00           0.00           ~     (all equal)
TrimASCII/1:2               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:4               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:8               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:16              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:1              0.00           0.00           ~     (all equal)
TrimASCII/16:2              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:4              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:8              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:16             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:1             0.00           0.00           ~     (all equal)
TrimASCII/256:2             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:4             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:8             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:16            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:1            0.00           0.00           ~     (all equal)
TrimASCII/4096:2            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:4            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:8            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:16           2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimByte                    0.00           0.00           ~     (all equal)
TrimSpace/NoTrim            0.00           0.00           ~     (all equal)
TrimSpace/ASCII             0.00           0.00           ~     (all equal)
TrimSpace/SomeNonASCII      0.00           0.00           ~     (all equal)
TrimSpace/JustNonASCII      0.00           0.00           ~     (all equal)

bytes:
name                    old time/op    new time/op    delta
TrimSpace/NoTrim          5.89ns ± 0%    5.91ns ± 0%      ~     (p=0.095 n=5+4)
TrimSpace/ASCII           10.3ns ± 1%    10.2ns ± 0%      ~     (p=0.095 n=5+5)
TrimSpace/SomeNonASCII     120ns ± 1%     121ns ± 0%    +1.13%  (p=0.008 n=5+5)
TrimSpace/JustNonASCII     194ns ± 1%     195ns ± 0%      ~     (p=0.143 n=5+5)
TrimASCII/1:1             6.28ns ± 0%    5.95ns ± 0%    -5.26%  (p=0.008 n=5+5)
TrimASCII/1:2             95.8ns ± 1%    18.6ns ± 0%   -80.63%  (p=0.008 n=5+5)
TrimASCII/1:4             98.8ns ± 0%    22.1ns ± 0%   -77.62%  (p=0.008 n=5+5)
TrimASCII/1:8              107ns ± 0%      29ns ± 0%   -72.72%  (p=0.008 n=5+5)
TrimASCII/1:16             123ns ± 0%      44ns ± 1%   -64.30%  (p=0.008 n=5+5)
TrimASCII/16:1            13.2ns ± 0%    12.8ns ± 1%    -2.75%  (p=0.008 n=5+5)
TrimASCII/16:2             169ns ± 0%      33ns ± 0%   -80.33%  (p=0.008 n=5+5)
TrimASCII/16:4             173ns ± 0%      36ns ± 0%   -79.31%  (p=0.008 n=5+5)
TrimASCII/16:8             180ns ± 0%      43ns ± 0%   -76.02%  (p=0.008 n=5+5)
TrimASCII/16:16            197ns ± 2%      58ns ± 0%   -70.73%  (p=0.008 n=5+5)
TrimASCII/256:1            137ns ± 1%     136ns ± 0%    -0.82%  (p=0.016 n=5+5)
TrimASCII/256:2           1.40µs ± 0%    0.26µs ± 0%   -81.02%  (p=0.008 n=5+5)
TrimASCII/256:4           1.40µs ± 0%    0.27µs ± 0%   -80.83%  (p=0.008 n=5+5)
TrimASCII/256:8           1.41µs ± 0%    0.28µs ± 0%   -80.36%  (p=0.008 n=5+5)
TrimASCII/256:16          1.42µs ± 0%    0.29µs ± 0%   -79.48%  (p=0.008 n=5+5)
TrimASCII/4096:1          1.75µs ± 0%    1.75µs ± 0%      ~     (p=0.595 n=5+5)
TrimASCII/4096:2          20.9µs ± 0%     3.9µs ± 0%   -81.29%  (p=0.008 n=5+5)
TrimASCII/4096:4          20.9µs ± 0%     3.9µs ± 0%   -81.27%  (p=0.008 n=5+5)
TrimASCII/4096:8          20.9µs ± 0%     3.9µs ± 0%   -81.22%  (p=0.008 n=5+5)
TrimASCII/4096:16         20.9µs ± 0%     3.9µs ± 0%   -81.21%  (p=0.008 n=5+5)
TrimByte                  9.21ns ± 0%    9.30ns ± 0%    +0.91%  (p=0.008 n=5+5)

name                    old alloc/op   new alloc/op   delta
TrimSpace/NoTrim           0.00B          0.00B           ~     (all equal)
TrimSpace/ASCII            0.00B          0.00B           ~     (all equal)
TrimSpace/SomeNonASCII     0.00B          0.00B           ~     (all equal)
TrimSpace/JustNonASCII     0.00B          0.00B           ~     (all equal)
TrimASCII/1:1              0.00B          0.00B           ~     (all equal)
TrimASCII/1:2              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:4              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:8              48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:16             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:1             0.00B          0.00B           ~     (all equal)
TrimASCII/16:2             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:4             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:8             48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:16            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:1            0.00B          0.00B           ~     (all equal)
TrimASCII/256:2            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:4            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:8            48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:16           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:1           0.00B          0.00B           ~     (all equal)
TrimASCII/4096:2           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:4           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:8           48.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:16          49.0B ± 0%      0.0B       -100.00%  (p=0.008 n=5+5)
TrimByte                   0.00B          0.00B           ~     (all equal)

name                    old allocs/op  new allocs/op  delta
TrimSpace/NoTrim            0.00           0.00           ~     (all equal)
TrimSpace/ASCII             0.00           0.00           ~     (all equal)
TrimSpace/SomeNonASCII      0.00           0.00           ~     (all equal)
TrimSpace/JustNonASCII      0.00           0.00           ~     (all equal)
TrimASCII/1:1               0.00           0.00           ~     (all equal)
TrimASCII/1:2               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:4               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:8               2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/1:16              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:1              0.00           0.00           ~     (all equal)
TrimASCII/16:2              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:4              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:8              2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/16:16             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:1             0.00           0.00           ~     (all equal)
TrimASCII/256:2             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:4             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:8             2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/256:16            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:1            0.00           0.00           ~     (all equal)
TrimASCII/4096:2            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:4            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:8            2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimASCII/4096:16           2.00 ± 0%      0.00       -100.00%  (p=0.008 n=5+5)
TrimByte                    0.00           0.00           ~     (all equal)

Fixes #46446

Change-Id: I9537c86f888af6285027f67bda4a97aeedb41d4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/332771
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Joe Tsai <joetsai@digital-static.net>
Trust: Joe Tsai <joetsai@digital-static.net>
Trust: Than McIntosh <thanm@google.com>
2021-10-06 22:42:28 +00:00
Russ Cox 8e36ab0551 bytes, strings: add Cut
Using Cut is a clearer way to write the vast majority (>70%)
of existing code that calls Index, IndexByte, IndexRune, and SplitN.
There is more discussion on https://golang.org/issue/46336.

Fixes #46336.

Change-Id: Ia418ed7c3706c65bf61e1b2c5baf534cb783e4d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/351710
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-10-06 15:53:00 +00:00
Joe Tsai 5baf60d472 bytes, strings: optimize Trim for single byte cutsets
Using the latest version of all modules known by the module proxy,
we determine that for all Trim usages (and related functionality):
* 76.6% have cutsets of len=1, and
* 13.4% have cutsets of len=2.

Given that a vast majority of usages only have a cutset of len=1,
we should more heavily optimize for that situation.
Previously, there was some optimization for cutsets of len=1,
but it's within the internal makeCutsetFunc function.
This is sub-optimal as it incurs an allocation in makeCutsetFunc
for the closure over that single byte.

This CL removes special-casing of one-byte cutsets from makeCutsetFunc
and instead distributes it directly in Trim, TrimRight, and TrimLeft.
Whether we should distribute the entire ASCII cutset logic into Trim
is a future CL that should be discussed and handled separately.
The evidence for multibyte cutsets is not as obviously compelling.

name                old time/op  new time/op  delta
bytes/TrimByte-4    84.1ns ± 2%   7.5ns ± 1%  -91.10%  (p=0.000 n=9+7)
strings/TrimByte-4  86.2ns ± 3%   8.3ns ± 1%  -90.33%  (p=0.000 n=9+10)

Fixes #46446

Change-Id: Ia0e31a8384c3ce111ae35465605bcec45df2ebec
Reviewed-on: https://go-review.googlesource.com/c/go/+/323318
Trust: Joe Tsai <joetsai@digital-static.net>
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
2021-08-25 19:29:15 +00:00
Michael Munday 11cdbab9d4 bytes, internal/bytealg: fix incorrect IndexString usage
The IndexString implementation in the bytealg package requires that
the string passed into it be in the range '2 <= len(s) <= MaxLen'
where MaxLen may be any value (including 0).

CL 156998 added calls to bytealg.IndexString where MaxLen was not
first checked. This led to an illegal instruction on s390x with
the vector facility disabled.

This CL guards the calls to bytealg.IndexString with a MaxLen check.
If the check fails then the code now falls back to the pre CL 156998
implementation (a loop over the runes in the string).

Since the MaxLen check is now in place the generic implementation is
no longer called so I have returned it to its original unimplemented
state.

In future we may want to drop MaxLen to prevent this kind of
confusion.

Fixes #41552.

Change-Id: Ibeb3f08720444a05c08d719ed97f6cef2423bbe9
Reviewed-on: https://go-review.googlesource.com/c/go/+/256717
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Michael Munday <mike.munday@ibm.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-09-23 19:55:33 +00:00
Robert Griesemer 45d288718d bytes: simpler and faster FieldsFunc (apply same changes as for strings)
This change applies the recent changes to the strings package
(https://golang.org/cl/229765) to this package, with relevant
local adjustments.

In contrast to the changes in strings, for the bytes package
this change leads to a nice performance improvement of >10%.

Benchmarks run on a "quiet" MacBook Pro, 3.3GHz Dual-Core Intel Core i7,
with 16GB 2133MHz LPDDR3 RAM running macOS 10.15.4.

name                        old time/op    new time/op     delta
FieldsFunc/ASCII/16-4          191ns ± 9%      163ns ± 2%  -14.66%  (p=0.008 n=5+5)
FieldsFunc/ASCII/256-4        2.08µs ± 5%     1.80µs ± 8%  -13.51%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4       36.1µs ± 2%     31.7µs ± 7%  -12.34%  (p=0.008 n=5+5)
FieldsFunc/ASCII/65536-4       584µs ± 3%      517µs ± 3%  -11.52%  (p=0.008 n=5+5)
FieldsFunc/ASCII/1048576-4    9.45ms ± 3%     8.11ms ± 8%  -14.19%  (p=0.008 n=5+5)
FieldsFunc/Mixed/16-4          202ns ± 2%      181ns ± 2%  -10.02%  (p=0.008 n=5+5)
FieldsFunc/Mixed/256-4        2.12µs ± 6%     1.78µs ± 3%  -16.16%  (p=0.008 n=5+5)
FieldsFunc/Mixed/4096-4       40.4µs ± 2%     36.1µs ± 1%  -10.66%  (p=0.008 n=5+5)
FieldsFunc/Mixed/65536-4       700µs ± 5%      612µs ± 1%  -12.59%  (p=0.008 n=5+5)
FieldsFunc/Mixed/1048576-4    11.2ms ± 8%     10.3ms ± 4%   -8.15%  (p=0.008 n=5+5)

name                        old speed      new speed       delta
FieldsFunc/ASCII/16-4       84.0MB/s ± 9%   98.3MB/s ± 2%  +17.04%  (p=0.008 n=5+5)
FieldsFunc/ASCII/256-4       123MB/s ± 5%    143MB/s ± 8%  +15.74%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4      113MB/s ± 2%    130MB/s ± 6%  +14.20%  (p=0.008 n=5+5)
FieldsFunc/ASCII/65536-4     112MB/s ± 2%    127MB/s ± 3%  +13.05%  (p=0.008 n=5+5)
FieldsFunc/ASCII/1048576-4   111MB/s ± 3%    130MB/s ± 8%  +16.66%  (p=0.008 n=5+5)
FieldsFunc/Mixed/16-4       79.3MB/s ± 2%   88.2MB/s ± 2%  +11.15%  (p=0.008 n=5+5)
FieldsFunc/Mixed/256-4       121MB/s ± 5%    144MB/s ± 3%  +19.19%  (p=0.008 n=5+5)
FieldsFunc/Mixed/4096-4      101MB/s ± 2%    113MB/s ± 1%  +11.92%  (p=0.008 n=5+5)
FieldsFunc/Mixed/65536-4    93.7MB/s ± 5%  107.1MB/s ± 1%  +14.31%  (p=0.008 n=5+5)
FieldsFunc/Mixed/1048576-4  93.6MB/s ± 8%  101.8MB/s ± 4%   +8.77%  (p=0.008 n=5+5)

name                        old alloc/op   new alloc/op    delta
FieldsFunc/ASCII/16-4          80.0B ± 0%      80.0B ± 0%     ~     (all equal)
FieldsFunc/ASCII/256-4          768B ± 0%       768B ± 0%     ~     (all equal)
FieldsFunc/ASCII/4096-4       24.8kB ± 0%     24.8kB ± 0%     ~     (all equal)
FieldsFunc/ASCII/65536-4       497kB ± 0%      497kB ± 0%     ~     (p=0.444 n=5+5)
FieldsFunc/ASCII/1048576-4    9.61MB ± 0%     9.61MB ± 0%     ~     (p=0.500 n=5+5)
FieldsFunc/Mixed/16-4          96.0B ± 0%      96.0B ± 0%     ~     (all equal)
FieldsFunc/Mixed/256-4          768B ± 0%       768B ± 0%     ~     (all equal)
FieldsFunc/Mixed/4096-4       24.8kB ± 0%     24.8kB ± 0%     ~     (all equal)
FieldsFunc/Mixed/65536-4       497kB ± 0%      497kB ± 0%     ~     (all equal)
FieldsFunc/Mixed/1048576-4    9.61MB ± 0%     9.61MB ± 0%     ~     (p=0.881 n=5+5)

name                        old allocs/op  new allocs/op   delta
FieldsFunc/ASCII/16-4           1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/256-4          1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/4096-4         5.00 ± 0%       5.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/65536-4        12.0 ± 0%       12.0 ± 0%     ~     (all equal)
FieldsFunc/ASCII/1048576-4      24.0 ± 0%       24.0 ± 0%     ~     (all equal)
FieldsFunc/Mixed/16-4           1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/256-4          1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/4096-4         5.00 ± 0%       5.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/65536-4        12.0 ± 0%       12.0 ± 0%     ~     (all equal)
FieldsFunc/Mixed/1048576-4      24.0 ± 0%       24.0 ± 0%     ~     (all equal)

Change-Id: I59a2ed52563851c693b2c8dfce7e3cde640f62a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/231120
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-05-01 03:49:21 +00:00
Martin Möhrmann f2163c4d45 bytes, strings: align requirements for functions passed to FieldFuncs
golang.org/cl/229763 removed the documentation of requirements of
the function passed to FieldsFunc. The current implementation does
not require functions to return consistent results but this had not
been the case for previous implementations.

Add the requirement for consistent results back to the documentation
to allow for future implementations to be more allocation efficient
for an output with more than 32 fields. This is possible with a two
pass algorithm first determining the number of fields used to allocate
the output slice and then splitting the input into fields.

While at it align the documentation of bytes.FieldsFunc with
strings.FieldFunc.

Fixes #38630

Change-Id: Iabbf9ca3dff0daa41f4ec930a21a3dd98e19f122
Reviewed-on: https://go-review.googlesource.com/c/go/+/230797
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-29 19:58:47 +00:00
Andy Pan 1250a324b4 bytes: narrow the search of IndexByte in Index
Change-Id: I5a47b18b64e7f781dcc77440b06de36966e3d01d
GitHub-Last-Rev: 8576f1931d
GitHub-Pull-Request: golang/go#37993
Reviewed-on: https://go-review.googlesource.com/c/go/+/224589
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-23 03:44:45 +00:00
erifan01 3af92acb9f strings, bytes: improve IndexAny and LastIndexAny performance
For the case of a pattern containing multi-byte rune, the time complexity of the
previous algorithm is O(nm), and if both input arguments are long, the search
performance will be poor. This CL improves the searching performance for these
cases by using IndexRune, which is mainly implemented with IndexByte and Index.
As IndexByte and Index are specially optimized with some powerful instructions
for short patterns (an UTF8 rune is 1 to 4 bytes), so they can help to reduce the
runtime complexity of IndexAny and LastIndexAny.

Another optimization method is using hash table, however, the actual test results
show that using indexrune is better, and the space complexity is lower.

There are two fast paths in IndexAny and LastIndexAny for cases where the length
of the input arguements are 1, and their locations are not exactly the same, which
is determined based on the actual test results.

Benchmarks on arm64 and amd64:

name                        old time/op  new time/op  delta
pkg:strings goos:linux goarch:arm64
IndexAnyASCII/1:1-8         23.7ns ± 3%  28.5ns ± 0%  +20.15%  (p=0.008 n=5+5)
IndexAnyASCII/1:2-8         18.0ns ± 0%  33.1ns ± 0%  +83.67%  (p=0.008 n=5+5)
IndexAnyASCII/1:4-8         20.0ns ± 0%  36.0ns ± 0%  +80.00%  (p=0.029 n=4+4)
IndexAnyASCII/1:8-8         36.1ns ± 0%  36.0ns ± 0%     ~     (p=0.095 n=5+4)
IndexAnyASCII/1:16-8        48.1ns ± 0%  36.0ns ± 0%  -25.19%  (p=0.029 n=4+4)
IndexAnyASCII/1:32-8        72.1ns ± 0%  36.0ns ± 0%  -50.01%  (p=0.008 n=5+5)
IndexAnyASCII/1:64-8         120ns ± 0%    39ns ± 0%  -67.83%  (p=0.008 n=5+5)
IndexAnyASCII/16:1-8        73.0ns ± 0%  28.5ns ± 0%  -60.95%  (p=0.008 n=5+5)
IndexAnyASCII/16:2-8        76.8ns ± 0%  77.0ns ± 0%     ~     (p=1.000 n=5+5)
IndexAnyASCII/16:4-8        83.2ns ± 1%  83.0ns ± 0%     ~     (p=0.770 n=5+5)
IndexAnyASCII/16:8-8         111ns ± 1%   107ns ± 0%   -3.25%  (p=0.008 n=5+5)
IndexAnyASCII/16:16-8        139ns ± 1%   137ns ± 0%   -1.58%  (p=0.008 n=5+5)
IndexAnyASCII/16:32-8        199ns ± 1%   197ns ± 0%   -1.20%  (p=0.008 n=5+5)
IndexAnyASCII/16:64-8        307ns ± 0%   313ns ± 0%   +1.82%  (p=0.016 n=5+4)
IndexAnyASCII/256:1-8        674ns ± 0%    65ns ± 0%  -90.31%  (p=0.008 n=5+5)
IndexAnyASCII/256:2-8        678ns ± 0%   683ns ± 0%   +0.68%  (p=0.008 n=5+5)
IndexAnyASCII/256:4-8        685ns ± 0%   683ns ± 0%   -0.29%  (p=0.000 n=5+4)
IndexAnyASCII/256:8-8        711ns ± 0%   708ns ± 0%   -0.48%  (p=0.008 n=5+5)
IndexAnyASCII/256:16-8       740ns ± 0%   740ns ± 0%     ~     (p=0.444 n=5+5)
IndexAnyASCII/256:32-8       799ns ± 0%   798ns ± 0%   -0.18%  (p=0.008 n=5+5)
IndexAnyASCII/256:64-8       910ns ± 0%   914ns ± 0%   +0.44%  (p=0.016 n=4+5)
IndexAnyUTF8/1:1-8          27.1ns ± 0%  19.0ns ± 0%  -29.79%  (p=0.008 n=5+5)
IndexAnyUTF8/1:2-8          44.1ns ± 0%  33.0ns ± 0%  -25.17%  (p=0.008 n=5+5)
IndexAnyUTF8/1:4-8          46.1ns ± 0%  33.1ns ± 0%  -28.29%  (p=0.016 n=4+5)
IndexAnyUTF8/1:8-8          85.1ns ± 0%  33.0ns ± 0%  -61.18%  (p=0.008 n=5+5)
IndexAnyUTF8/1:16-8          110ns ± 1%    36ns ± 0%  -67.27%  (p=0.008 n=5+5)
IndexAnyUTF8/1:32-8          188ns ± 0%    36ns ± 0%  -80.85%  (p=0.008 n=5+5)
IndexAnyUTF8/1:64-8          332ns ± 0%    39ns ± 0%     ~     (p=0.079 n=4+5)
IndexAnyUTF8/16:1-8          293ns ± 0%    54ns ± 0%  -81.56%  (p=0.008 n=5+5)
IndexAnyUTF8/16:2-8          563ns ± 0%   349ns ± 0%  -37.98%  (p=0.008 n=5+5)
IndexAnyUTF8/16:4-8          546ns ± 1%   349ns ± 0%  -36.10%  (p=0.000 n=5+4)
IndexAnyUTF8/16:8-8         1.22µs ± 0%  0.35µs ± 0%  -71.39%  (p=0.008 n=5+5)
IndexAnyUTF8/16:16-8        1.63µs ± 1%  0.42µs ± 0%  -73.98%  (p=0.008 n=5+5)
IndexAnyUTF8/16:32-8        2.87µs ± 0%  0.42µs ± 0%  -85.22%  (p=0.008 n=5+5)
IndexAnyUTF8/16:64-8        5.18µs ± 0%  0.47µs ± 0%  -90.98%  (p=0.008 n=5+5)
IndexAnyUTF8/256:1-8        4.26µs ± 0%  0.47µs ± 0%  -88.85%  (p=0.000 n=4+5)
IndexAnyUTF8/256:2-8        8.62µs ± 0%  5.15µs ± 0%  -40.21%  (p=0.008 n=5+5)
IndexAnyUTF8/256:4-8        8.25µs ± 0%  5.15µs ± 0%  -37.50%  (p=0.016 n=5+4)
IndexAnyUTF8/256:8-8        19.2µs ± 1%   5.2µs ± 0%  -73.08%  (p=0.016 n=5+4)
IndexAnyUTF8/256:16-8       25.6µs ± 1%   6.3µs ± 0%  -75.32%  (p=0.008 n=5+5)
IndexAnyUTF8/256:32-8       45.6µs ± 0%   6.3µs ± 0%  -86.15%  (p=0.008 n=5+5)
IndexAnyUTF8/256:64-8       82.4µs ± 0%   7.0µs ± 0%  -91.53%  (p=0.016 n=5+4)
LastIndexAnyASCII/1:1-8     23.0ns ± 0%  33.5ns ± 0%  +45.65%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:2-8     24.5ns ± 0%  33.5ns ± 0%  +36.73%  (p=0.016 n=4+5)
LastIndexAnyASCII/1:4-8     27.5ns ± 0%  35.5ns ± 0%  +29.09%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:8-8     44.5ns ± 0%  35.5ns ± 0%  -20.13%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:16-8    56.5ns ± 0%  35.5ns ± 0%  -37.15%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:32-8    80.3ns ± 0%  35.5ns ± 0%  -55.79%  (p=0.000 n=5+4)
LastIndexAnyASCII/1:64-8     129ns ± 0%    40ns ± 0%  -68.85%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:1-8    72.8ns ± 0%  72.7ns ± 0%   -0.19%  (p=0.016 n=4+5)
LastIndexAnyASCII/16:2-8    75.4ns ± 0%  75.1ns ± 0%     ~     (p=0.127 n=5+5)
LastIndexAnyASCII/16:4-8    81.9ns ± 1%  80.2ns ± 0%   -2.00%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:8-8     110ns ± 1%   108ns ± 0%   -1.46%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:16-8    138ns ± 1%   134ns ± 0%   -3.18%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:32-8    198ns ± 0%   197ns ± 0%   -0.51%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:64-8    309ns ± 0%   313ns ± 0%   +1.30%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:1-8    652ns ± 0%   653ns ± 0%   +0.21%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:2-8    656ns ± 0%   656ns ± 0%     ~     (all equal)
LastIndexAnyASCII/256:4-8    663ns ± 0%   663ns ± 0%     ~     (p=0.444 n=5+5)
LastIndexAnyASCII/256:8-8    691ns ± 0%   690ns ± 0%     ~     (p=0.079 n=4+5)
LastIndexAnyASCII/256:16-8   719ns ± 0%   715ns ± 0%   -0.53%  (p=0.000 n=5+4)
LastIndexAnyASCII/256:32-8   779ns ± 0%   780ns ± 0%   +0.13%  (p=0.029 n=4+4)
LastIndexAnyASCII/256:64-8   890ns ± 0%   894ns ± 0%   +0.45%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:1-8      31.6ns ± 0%  33.5ns ± 0%   +6.01%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:2-8      48.6ns ± 0%  33.5ns ± 0%  -30.99%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:4-8      48.6ns ± 0%  33.5ns ± 0%  -31.13%  (p=0.000 n=5+4)
LastIndexAnyUTF8/1:8-8      89.6ns ± 0%  33.5ns ± 0%  -62.56%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:16-8      113ns ± 1%    36ns ± 0%  -68.47%  (p=0.000 n=5+4)
LastIndexAnyUTF8/1:32-8      190ns ± 0%    36ns ± 0%  -81.26%  (p=0.029 n=4+4)
LastIndexAnyUTF8/1:64-8      327ns ± 0%    40ns ± 0%  -87.77%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:1-8      364ns ± 0%   158ns ± 0%     ~     (p=0.079 n=4+5)
LastIndexAnyUTF8/16:2-8      636ns ± 0%   472ns ± 0%  -25.79%  (p=0.000 n=5+4)
LastIndexAnyUTF8/16:4-8      630ns ± 0%   472ns ± 0%  -25.03%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:8-8     1.28µs ± 0%  0.47µs ± 0%  -63.09%  (p=0.016 n=5+4)
LastIndexAnyUTF8/16:16-8    1.66µs ± 0%  0.53µs ± 0%  -68.39%  (p=0.016 n=5+4)
LastIndexAnyUTF8/16:32-8    2.88µs ± 0%  0.53µs ± 0%  -81.72%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:64-8    5.08µs ± 0%  0.57µs ± 0%  -88.79%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:1-8    5.41µs ± 0%  2.03µs ± 0%  -62.46%  (p=0.016 n=4+5)
LastIndexAnyUTF8/256:2-8    9.77µs ± 0%  7.14µs ± 0%  -26.97%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:4-8    9.63µs ± 0%  7.14µs ± 0%  -25.86%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:8-8    20.0µs ± 0%   7.1µs ± 0%  -64.30%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:16-8   26.1µs ± 1%   8.0µs ± 0%  -69.40%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:32-8   45.6µs ± 1%   8.0µs ± 0%  -82.51%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:64-8   80.8µs ± 0%   8.6µs ± 0%  -89.33%  (p=0.016 n=5+4)
pkg:bytes goos:linux goarch:arm64
IndexAnyASCII/1:1-8         26.2ns ± 1%  26.5ns ± 0%   +1.30%  (p=0.016 n=5+4)
IndexAnyASCII/1:2-8         18.5ns ± 0%  26.5ns ± 0%  +43.24%  (p=0.008 n=5+5)
IndexAnyASCII/1:4-8         21.0ns ± 0%  26.5ns ± 0%  +26.38%  (p=0.008 n=5+5)
IndexAnyASCII/1:8-8         37.5ns ± 0%  26.5ns ± 0%  -29.33%  (p=0.000 n=5+4)
IndexAnyASCII/1:16-8        49.6ns ± 0%  26.5ns ± 0%  -46.49%  (p=0.008 n=5+5)
IndexAnyASCII/1:32-8        73.6ns ± 0%  30.1ns ± 0%  -59.16%  (p=0.008 n=5+5)
IndexAnyASCII/1:64-8         122ns ± 0%    33ns ± 0%  -73.23%  (p=0.008 n=5+5)
IndexAnyASCII/16:1-8        73.7ns ± 0%  33.4ns ± 0%  -54.71%  (p=0.008 n=5+5)
IndexAnyASCII/16:2-8        79.1ns ± 0%  78.9ns ± 0%   -0.30%  (p=0.016 n=4+5)
IndexAnyASCII/16:4-8        84.8ns ± 0%  86.1ns ± 0%   +1.58%  (p=0.016 n=5+4)
IndexAnyASCII/16:8-8         111ns ± 0%   111ns ± 0%     ~     (all equal)
IndexAnyASCII/16:16-8        139ns ± 0%   144ns ± 0%   +3.60%  (p=0.016 n=4+5)
IndexAnyASCII/16:32-8        196ns ± 0%   207ns ± 0%   +5.61%  (p=0.016 n=5+4)
IndexAnyASCII/16:64-8        311ns ± 0%   320ns ± 0%   +2.89%  (p=0.016 n=4+5)
IndexAnyASCII/256:1-8        674ns ± 0%    65ns ± 1%  -90.35%  (p=0.008 n=5+5)
IndexAnyASCII/256:2-8        680ns ± 0%   680ns ± 0%     ~     (p=0.444 n=5+5)
IndexAnyASCII/256:4-8        686ns ± 0%   687ns ± 0%     ~     (p=0.167 n=5+5)
IndexAnyASCII/256:8-8        713ns ± 0%   712ns ± 0%   -0.14%  (p=0.008 n=5+5)
IndexAnyASCII/256:16-8       740ns ± 0%   744ns ± 0%   +0.54%  (p=0.016 n=5+4)
IndexAnyASCII/256:32-8       797ns ± 0%   808ns ± 0%   +1.43%  (p=0.008 n=5+5)
IndexAnyASCII/256:64-8       912ns ± 0%   921ns ± 0%   +0.99%  (p=0.016 n=4+5)
IndexAnyUTF8/1:1-8          27.5ns ± 0%  26.5ns ± 0%   -3.64%  (p=0.008 n=5+5)
IndexAnyUTF8/1:2-8          44.5ns ± 0%  26.5ns ± 0%  -40.50%  (p=0.008 n=5+5)
IndexAnyUTF8/1:4-8          45.6ns ± 0%  26.5ns ± 0%  -41.89%  (p=0.000 n=5+4)
IndexAnyUTF8/1:8-8          85.8ns ± 1%  26.5ns ± 0%  -69.11%  (p=0.008 n=5+5)
IndexAnyUTF8/1:16-8          110ns ± 1%    26ns ± 0%  -76.00%  (p=0.016 n=5+4)
IndexAnyUTF8/1:32-8          188ns ± 0%    30ns ± 0%  -84.04%  (p=0.008 n=5+5)
IndexAnyUTF8/1:64-8          333ns ± 0%    33ns ± 0%  -90.20%  (p=0.008 n=5+5)
IndexAnyUTF8/16:1-8          294ns ± 0%   235ns ± 0%  -20.07%  (p=0.008 n=5+5)
IndexAnyUTF8/16:2-8          563ns ± 0%   309ns ± 0%  -45.12%  (p=0.008 n=5+5)
IndexAnyUTF8/16:4-8          558ns ± 1%   309ns ± 0%  -44.60%  (p=0.000 n=5+4)
IndexAnyUTF8/16:8-8         1.23µs ± 0%  0.31µs ± 0%  -74.79%  (p=0.008 n=5+5)
IndexAnyUTF8/16:16-8        1.62µs ± 2%  0.31µs ± 0%  -80.93%  (p=0.008 n=5+5)
IndexAnyUTF8/16:32-8        2.86µs ± 0%  0.38µs ± 0%  -86.87%  (p=0.008 n=5+5)
IndexAnyUTF8/16:64-8        5.18µs ± 0%  0.42µs ± 0%  -91.86%  (p=0.008 n=5+5)
IndexAnyUTF8/256:1-8        4.27µs ± 1%  3.30µs ± 1%  -22.75%  (p=0.008 n=5+5)
IndexAnyUTF8/256:2-8        8.61µs ± 0%  4.45µs ± 0%  -48.31%  (p=0.016 n=4+5)
IndexAnyUTF8/256:4-8        8.44µs ± 0%  4.45µs ± 0%  -47.23%  (p=0.008 n=5+5)
IndexAnyUTF8/256:8-8        19.2µs ± 0%   4.5µs ± 0%  -76.78%  (p=0.008 n=5+5)
IndexAnyUTF8/256:16-8       25.6µs ± 0%   4.5µs ± 0%  -82.63%  (p=0.008 n=5+5)
IndexAnyUTF8/256:32-8       45.4µs ± 0%   5.5µs ± 0%  -87.85%  (p=0.016 n=4+5)
IndexAnyUTF8/256:64-8       82.5µs ± 0%   6.2µs ± 0%  -92.49%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:1-8     23.0ns ± 0%  26.5ns ± 0%  +15.02%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:2-8     24.5ns ± 0%  26.5ns ± 0%   +8.16%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:4-8     27.8ns ± 0%  26.5ns ± 0%   -4.68%  (p=0.029 n=4+4)
LastIndexAnyASCII/1:8-8     45.1ns ± 1%  26.5ns ± 0%  -41.29%  (p=0.000 n=5+4)
LastIndexAnyASCII/1:16-8    57.1ns ± 0%  26.5ns ± 0%  -53.61%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:32-8    81.5ns ± 0%  30.0ns ± 0%     ~     (p=0.079 n=4+5)
LastIndexAnyASCII/1:64-8     129ns ± 0%    32ns ± 0%  -74.81%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:1-8    72.6ns ± 0%  72.1ns ± 0%   -0.63%  (p=0.000 n=4+5)
LastIndexAnyASCII/16:2-8    77.2ns ± 0%  77.2ns ± 0%     ~     (p=0.167 n=5+5)
LastIndexAnyASCII/16:4-8    83.1ns ± 0%  83.2ns ± 0%     ~     (p=0.444 n=5+5)
LastIndexAnyASCII/16:8-8     109ns ± 1%   108ns ± 0%     ~     (p=0.167 n=5+5)
LastIndexAnyASCII/16:16-8    136ns ± 0%   136ns ± 0%     ~     (all equal)
LastIndexAnyASCII/16:32-8    195ns ± 0%   197ns ± 0%   +0.82%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:64-8    309ns ± 0%   309ns ± 0%     ~     (all equal)
LastIndexAnyASCII/256:1-8    653ns ± 0%   657ns ± 0%   +0.61%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:2-8    659ns ± 0%   658ns ± 0%     ~     (p=0.167 n=5+5)
LastIndexAnyASCII/256:4-8    664ns ± 0%   663ns ± 0%     ~     (p=0.095 n=5+4)
LastIndexAnyASCII/256:8-8    698ns ± 0%   689ns ± 0%   -1.29%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:16-8   726ns ± 0%   717ns ± 0%   -1.24%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:32-8   777ns ± 0%   779ns ± 0%     ~     (p=0.079 n=5+4)
LastIndexAnyASCII/256:64-8   889ns ± 0%   890ns ± 0%     ~     (p=0.444 n=5+5)
LastIndexAnyUTF8/1:1-8      32.1ns ± 0%  26.5ns ± 0%  -17.45%  (p=0.000 n=5+4)
LastIndexAnyUTF8/1:2-8      48.6ns ± 0%  26.5ns ± 0%  -45.52%  (p=0.000 n=5+4)
LastIndexAnyUTF8/1:4-8      49.6ns ± 0%  26.5ns ± 0%  -46.62%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:8-8      91.9ns ± 0%  26.5ns ± 0%  -71.18%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:16-8      114ns ± 1%    26ns ± 0%  -76.84%  (p=0.000 n=5+4)
LastIndexAnyUTF8/1:32-8      203ns ± 6%    30ns ± 0%  -85.25%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:64-8      330ns ± 0%    33ns ± 0%  -90.14%  (p=0.000 n=4+5)
LastIndexAnyUTF8/16:1-8      365ns ± 0%   164ns ± 0%  -55.04%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:2-8      638ns ± 0%   296ns ± 0%  -53.58%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:4-8      634ns ± 0%   296ns ± 0%  -53.31%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:8-8     1.30µs ± 0%  0.30µs ± 0%  -77.18%  (p=0.000 n=4+5)
LastIndexAnyUTF8/16:16-8    1.66µs ± 0%  0.30µs ± 0%  -82.19%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:32-8    2.90µs ± 0%  0.38µs ± 0%  -87.00%  (p=0.029 n=4+4)
LastIndexAnyUTF8/16:64-8    5.10µs ± 0%  0.42µs ± 0%  -91.78%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:1-8    5.42µs ± 0%  2.12µs ± 0%  -60.92%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:2-8    9.79µs ± 0%  4.26µs ± 0%  -56.47%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:4-8    9.66µs ± 0%  4.26µs ± 0%  -55.87%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:8-8    20.4µs ± 0%   4.3µs ± 0%  -79.10%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:16-8   26.0µs ± 1%   4.3µs ± 0%  -83.62%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:32-8   46.0µs ± 0%   5.5µs ± 0%  -88.09%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:64-8   81.1µs ± 0%   6.2µs ± 0%  -92.38%  (p=0.008 n=5+5)

name                         old time/op  new time/op   delta
pkg:strings goos:linux goarch:amd64
IndexAnyASCII/1:1-48         10.0ns ± 0%   13.3ns ± 0%  +33.00%  (p=0.008 n=5+5)
IndexAnyASCII/1:2-48         11.0ns ± 0%   15.5ns ± 0%  +40.55%  (p=0.016 n=4+5)
IndexAnyASCII/1:4-48         12.9ns ± 0%   15.4ns ± 0%  +19.69%  (p=0.008 n=5+5)
IndexAnyASCII/1:8-48         18.6ns ± 0%   15.5ns ± 0%  -16.45%  (p=0.000 n=4+5)
IndexAnyASCII/1:16-48        30.1ns ± 0%   16.9ns ± 0%     ~     (p=0.079 n=4+5)
IndexAnyASCII/1:32-48        53.1ns ± 0%   18.6ns ± 0%  -64.95%  (p=0.000 n=5+4)
IndexAnyASCII/1:64-48        98.9ns ± 0%   17.4ns ± 0%  -82.41%  (p=0.000 n=5+4)
IndexAnyASCII/16:1-48        35.0ns ± 0%   14.2ns ± 0%  -59.47%  (p=0.000 n=5+4)
IndexAnyASCII/16:2-48        35.5ns ± 0%   35.6ns ± 0%     ~     (p=0.238 n=5+4)
IndexAnyASCII/16:4-48        40.8ns ± 0%   40.7ns ± 1%     ~     (p=0.643 n=5+5)
IndexAnyASCII/16:8-48        50.8ns ± 0%   50.9ns ± 1%     ~     (p=1.000 n=4+5)
IndexAnyASCII/16:16-48       64.0ns ± 1%   64.5ns ± 1%     ~     (p=0.071 n=5+5)
IndexAnyASCII/16:32-48       98.3ns ± 0%  100.8ns ± 1%   +2.52%  (p=0.008 n=5+5)
IndexAnyASCII/16:64-48        156ns ± 0%    157ns ± 0%     ~     (p=0.238 n=4+5)
IndexAnyASCII/256:1-48        299ns ± 0%     24ns ± 3%  -92.12%  (p=0.008 n=5+5)
IndexAnyASCII/256:2-48        303ns ± 0%    304ns ± 0%     ~     (p=0.762 n=5+5)
IndexAnyASCII/256:4-48        311ns ± 0%    311ns ± 0%     ~     (p=0.476 n=5+5)
IndexAnyASCII/256:8-48        321ns ± 0%    321ns ± 0%     ~     (p=0.429 n=4+5)
IndexAnyASCII/256:16-48       334ns ± 0%    335ns ± 0%     ~     (p=0.079 n=5+4)
IndexAnyASCII/256:32-48       367ns ± 0%    365ns ± 0%     ~     (p=0.079 n=4+5)
IndexAnyASCII/256:64-48       431ns ± 1%    421ns ± 0%   -2.27%  (p=0.008 n=5+5)
IndexAnyUTF8/1:1-48          17.2ns ± 0%   10.8ns ± 0%  -37.21%  (p=0.029 n=4+4)
IndexAnyUTF8/1:2-48          26.7ns ± 0%   15.6ns ± 0%     ~     (p=0.079 n=4+5)
IndexAnyUTF8/1:4-48          28.2ns ± 0%   15.6ns ± 0%  -44.68%  (p=0.000 n=5+4)
IndexAnyUTF8/1:8-48          48.8ns ± 0%   15.6ns ± 0%  -68.03%  (p=0.029 n=4+4)
IndexAnyUTF8/1:16-48         58.3ns ± 0%   16.2ns ± 0%     ~     (p=0.079 n=4+5)
IndexAnyUTF8/1:32-48          103ns ± 0%     18ns ± 0%  -82.27%  (p=0.008 n=5+5)
IndexAnyUTF8/1:64-48          182ns ± 0%     17ns ± 0%  -90.53%  (p=0.008 n=5+5)
IndexAnyUTF8/16:1-48          197ns ± 0%     25ns ± 0%  -87.34%  (p=0.000 n=5+4)
IndexAnyUTF8/16:2-48          348ns ± 0%    163ns ± 0%  -53.11%  (p=0.000 n=5+4)
IndexAnyUTF8/16:4-48          374ns ± 0%    163ns ± 0%  -56.37%  (p=0.000 n=5+4)
IndexAnyUTF8/16:8-48          716ns ± 0%    163ns ± 0%  -77.22%  (p=0.000 n=5+4)
IndexAnyUTF8/16:16-48         859ns ± 0%    175ns ± 0%  -79.63%  (p=0.000 n=5+4)
IndexAnyUTF8/16:32-48        1.58µs ± 0%   0.20µs ± 0%  -87.01%  (p=0.029 n=4+4)
IndexAnyUTF8/16:64-48        2.84µs ± 0%   0.19µs ± 1%  -93.34%  (p=0.008 n=5+5)
IndexAnyUTF8/256:1-48        2.61µs ± 0%   0.27µs ± 0%  -89.81%  (p=0.008 n=5+5)
IndexAnyUTF8/256:2-48        4.95µs ± 0%   2.23µs ± 0%  -54.91%  (p=0.016 n=5+4)
IndexAnyUTF8/256:4-48        5.55µs ± 0%   2.23µs ± 0%  -59.72%  (p=0.008 n=5+5)
IndexAnyUTF8/256:8-48        10.8µs ± 0%    2.2µs ± 0%  -79.39%  (p=0.008 n=5+5)
IndexAnyUTF8/256:16-48       13.1µs ± 0%    2.5µs ± 0%  -81.21%  (p=0.016 n=4+5)
IndexAnyUTF8/256:32-48       24.7µs ± 0%    2.8µs ± 0%  -88.49%  (p=0.008 n=5+5)
IndexAnyUTF8/256:64-48       45.0µs ± 0%    2.6µs ± 1%  -94.23%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:1-48     13.9ns ± 0%   15.2ns ± 0%   +9.35%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:2-48     14.4ns ± 0%   15.2ns ± 0%   +5.56%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:4-48     16.7ns ± 0%   15.2ns ± 0%   -8.98%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:8-48     24.0ns ± 0%   15.2ns ± 0%  -36.67%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:16-48    35.6ns ± 0%   15.0ns ± 0%  -57.82%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:32-48    68.9ns ± 0%   16.7ns ± 0%  -75.75%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:64-48     104ns ± 0%     17ns ± 1%  -83.81%  (p=0.008 n=5+5)
LastIndexAnyASCII/16:1-48    35.0ns ± 0%   35.0ns ± 0%     ~     (all equal)
LastIndexAnyASCII/16:2-48    35.6ns ± 0%   35.6ns ± 0%     ~     (all equal)
LastIndexAnyASCII/16:4-48    41.0ns ± 0%   40.8ns ± 0%   -0.49%  (p=0.032 n=5+5)
LastIndexAnyASCII/16:8-48    50.9ns ± 0%   50.7ns ± 1%     ~     (p=0.397 n=5+5)
LastIndexAnyASCII/16:16-48   64.3ns ± 1%   64.4ns ± 1%     ~     (p=1.000 n=4+5)
LastIndexAnyASCII/16:32-48    100ns ± 0%    100ns ± 0%   +0.38%  (p=0.016 n=4+5)
LastIndexAnyASCII/16:64-48    157ns ± 1%    163ns ± 0%   +3.82%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:1-48    302ns ± 0%    300ns ± 0%   -0.53%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:2-48    305ns ± 0%    303ns ± 0%   -0.66%  (p=0.000 n=5+4)
LastIndexAnyASCII/256:4-48    313ns ± 0%    307ns ± 0%   -2.04%  (p=0.000 n=4+5)
LastIndexAnyASCII/256:8-48    323ns ± 0%    315ns ± 0%   -2.48%  (p=0.029 n=4+4)
LastIndexAnyASCII/256:16-48   333ns ± 0%    332ns ± 0%   -0.30%  (p=0.048 n=5+5)
LastIndexAnyASCII/256:32-48   366ns ± 0%    367ns ± 0%     ~     (p=0.238 n=4+5)
LastIndexAnyASCII/256:64-48   430ns ± 0%    430ns ± 0%     ~     (p=1.000 n=5+5)
LastIndexAnyUTF8/1:1-48      21.1ns ± 0%   13.9ns ± 0%  -34.00%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:2-48      29.5ns ± 0%   13.9ns ± 0%  -52.95%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:4-48      31.6ns ± 0%   13.9ns ± 0%  -55.96%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:8-48      51.1ns ± 0%   13.9ns ± 0%  -72.81%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:16-48     58.9ns ± 0%   14.6ns ± 0%  -75.23%  (p=0.016 n=5+4)
LastIndexAnyUTF8/1:32-48      103ns ± 0%     16ns ± 1%  -84.12%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:64-48      177ns ± 0%     17ns ± 1%  -90.62%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:1-48      275ns ± 1%    105ns ± 0%  -61.85%  (p=0.000 n=5+4)
LastIndexAnyUTF8/16:2-48      406ns ± 0%    216ns ± 0%  -46.70%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:4-48      458ns ± 0%    216ns ± 0%  -52.75%  (p=0.000 n=4+5)
LastIndexAnyUTF8/16:8-48      753ns ± 0%    216ns ± 0%  -71.31%  (p=0.029 n=4+4)
LastIndexAnyUTF8/16:16-48     902ns ± 0%    221ns ± 0%  -75.50%  (p=0.016 n=5+4)
LastIndexAnyUTF8/16:32-48    1.57µs ± 0%   0.24µs ± 0%  -84.46%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:64-48    2.77µs ± 0%   0.24µs ± 0%  -91.22%  (p=0.000 n=5+4)
LastIndexAnyUTF8/256:1-48    4.06µs ± 0%   1.53µs ± 0%  -62.26%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:2-48    5.92µs ± 0%   3.04µs ± 0%  -48.55%  (p=0.016 n=4+5)
LastIndexAnyUTF8/256:4-48    6.82µs ± 0%   3.04µs ± 0%  -55.34%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:8-48    11.5µs ± 0%    3.0µs ± 0%  -73.48%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:16-48   14.1µs ± 0%    3.1µs ± 0%  -77.85%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:32-48   24.5µs ± 0%    3.5µs ± 0%  -85.85%  (p=0.016 n=5+4)
LastIndexAnyUTF8/256:64-48   44.0µs ± 0%    3.5µs ± 0%  -92.12%  (p=0.008 n=5+5)
pkg:bytes goos:linux goarch:amd64
IndexAnyASCII/1:1-48         9.56ns ± 0%  11.00ns ± 0%  +15.06%  (p=0.016 n=5+4)
IndexAnyASCII/1:2-48         11.0ns ± 0%   10.8ns ± 2%   -1.64%  (p=0.048 n=5+5)
IndexAnyASCII/1:4-48         13.9ns ± 0%   11.0ns ± 1%  -21.15%  (p=0.008 n=5+5)
IndexAnyASCII/1:8-48         19.6ns ± 0%   10.8ns ± 3%  -44.90%  (p=0.008 n=5+5)
IndexAnyASCII/1:16-48        31.1ns ± 0%   11.5ns ± 0%  -63.02%  (p=0.008 n=5+5)
IndexAnyASCII/1:32-48        54.0ns ± 0%   11.8ns ± 0%  -78.15%  (p=0.000 n=5+4)
IndexAnyASCII/1:64-48         100ns ± 0%     13ns ± 0%  -86.89%  (p=0.008 n=5+5)
IndexAnyASCII/16:1-48        35.5ns ± 0%   14.8ns ± 0%  -58.26%  (p=0.008 n=5+5)
IndexAnyASCII/16:2-48        36.2ns ± 1%   36.0ns ± 1%     ~     (p=0.087 n=5+5)
IndexAnyASCII/16:4-48        40.3ns ± 1%   39.7ns ± 4%     ~     (p=0.175 n=4+5)
IndexAnyASCII/16:8-48        48.7ns ± 5%   45.8ns ± 0%   -6.02%  (p=0.016 n=5+4)
IndexAnyASCII/16:16-48       64.1ns ±11%   62.1ns ± 1%     ~     (p=0.143 n=5+5)
IndexAnyASCII/16:32-48       97.9ns ± 1%   98.3ns ± 1%     ~     (p=0.294 n=5+5)
IndexAnyASCII/16:64-48        163ns ± 0%    157ns ± 0%   -3.68%  (p=0.008 n=5+5)
IndexAnyASCII/256:1-48        389ns ± 0%     25ns ± 0%  -93.65%  (p=0.000 n=5+4)
IndexAnyASCII/256:2-48        391ns ± 0%    307ns ± 0%  -21.48%  (p=0.000 n=5+4)
IndexAnyASCII/256:4-48        394ns ± 0%    323ns ± 0%  -17.92%  (p=0.008 n=5+5)
IndexAnyASCII/256:8-48        402ns ± 0%    323ns ± 0%  -19.51%  (p=0.008 n=5+5)
IndexAnyASCII/256:16-48       414ns ± 0%    334ns ± 0%  -19.32%  (p=0.016 n=4+5)
IndexAnyASCII/256:32-48       446ns ± 0%    367ns ± 0%  -17.75%  (p=0.016 n=5+4)
IndexAnyASCII/256:64-48       511ns ± 0%    424ns ± 0%  -17.02%  (p=0.008 n=5+5)
IndexAnyUTF8/1:1-48          17.4ns ± 0%   11.0ns ± 0%  -36.64%  (p=0.008 n=5+5)
IndexAnyUTF8/1:2-48          27.3ns ± 1%   11.0ns ± 0%  -59.74%  (p=0.008 n=5+5)
IndexAnyUTF8/1:4-48          28.7ns ± 0%   11.0ns ± 0%  -61.73%  (p=0.008 n=5+5)
IndexAnyUTF8/1:8-48          49.2ns ± 0%   11.0ns ± 0%  -77.66%  (p=0.008 n=5+5)
IndexAnyUTF8/1:16-48         56.0ns ± 0%   11.5ns ± 0%  -79.46%  (p=0.000 n=5+4)
IndexAnyUTF8/1:32-48          102ns ± 0%     12ns ± 0%  -88.24%  (p=0.008 n=5+5)
IndexAnyUTF8/1:64-48          177ns ± 0%     13ns ± 0%  -92.51%  (p=0.008 n=5+5)
IndexAnyUTF8/16:1-48          212ns ± 0%    112ns ± 0%  -47.17%  (p=0.008 n=5+5)
IndexAnyUTF8/16:2-48          356ns ± 0%    159ns ± 1%  -55.28%  (p=0.000 n=4+5)
IndexAnyUTF8/16:4-48          372ns ± 0%    158ns ± 0%  -57.47%  (p=0.008 n=5+5)
IndexAnyUTF8/16:8-48          712ns ± 0%    159ns ± 1%  -77.70%  (p=0.008 n=5+5)
IndexAnyUTF8/16:16-48         829ns ± 0%    129ns ± 0%  -84.44%  (p=0.008 n=5+5)
IndexAnyUTF8/16:32-48        1.55µs ± 0%   0.16µs ± 0%  -89.87%  (p=0.008 n=5+5)
IndexAnyUTF8/16:64-48        2.77µs ± 0%   0.14µs ± 0%  -94.94%  (p=0.008 n=5+5)
IndexAnyUTF8/256:1-48        2.85µs ± 0%   1.63µs ± 1%  -42.74%  (p=0.008 n=5+5)
IndexAnyUTF8/256:2-48        5.14µs ± 1%   2.03µs ± 0%  -60.51%  (p=0.008 n=5+5)
IndexAnyUTF8/256:4-48        5.56µs ± 0%   2.03µs ± 0%  -63.52%  (p=0.008 n=5+5)
IndexAnyUTF8/256:8-48        10.8µs ± 0%    2.0µs ± 0%  -81.22%  (p=0.008 n=5+5)
IndexAnyUTF8/256:16-48       12.9µs ± 0%    1.9µs ± 0%  -85.55%  (p=0.008 n=5+5)
IndexAnyUTF8/256:32-48       24.2µs ± 0%    2.1µs ± 0%  -91.29%  (p=0.016 n=5+4)
IndexAnyUTF8/256:64-48       43.7µs ± 0%    2.0µs ± 0%  -95.32%  (p=0.016 n=5+4)
LastIndexAnyASCII/1:1-48     13.7ns ± 1%   12.8ns ± 0%   -6.57%  (p=0.016 n=5+4)
LastIndexAnyASCII/1:2-48     14.7ns ± 0%   12.7ns ± 1%  -13.33%  (p=0.000 n=4+5)
LastIndexAnyASCII/1:4-48     16.9ns ± 0%   12.7ns ± 1%  -24.73%  (p=0.000 n=4+5)
LastIndexAnyASCII/1:8-48     20.5ns ± 0%   12.7ns ± 0%  -37.85%  (p=0.000 n=4+5)
LastIndexAnyASCII/1:16-48    28.0ns ± 0%   11.7ns ± 0%     ~     (p=0.079 n=4+5)
LastIndexAnyASCII/1:32-48    69.8ns ± 0%   12.4ns ± 0%  -82.19%  (p=0.008 n=5+5)
LastIndexAnyASCII/1:64-48    73.8ns ± 0%   13.3ns ± 0%  -82.03%  (p=0.000 n=4+5)
LastIndexAnyASCII/16:1-48    35.5ns ± 0%   35.5ns ± 0%     ~     (all equal)
LastIndexAnyASCII/16:2-48    36.0ns ± 0%   36.1ns ± 0%   +0.28%  (p=0.016 n=4+5)
LastIndexAnyASCII/16:4-48    40.3ns ± 2%   40.0ns ± 6%     ~     (p=0.651 n=5+5)
LastIndexAnyASCII/16:8-48    50.3ns ± 0%   50.2ns ± 9%     ~     (p=0.175 n=4+5)
LastIndexAnyASCII/16:16-48   62.4ns ± 4%   64.4ns ± 0%   +3.28%  (p=0.016 n=5+4)
LastIndexAnyASCII/16:32-48   98.9ns ± 0%   98.4ns ± 0%   -0.53%  (p=0.016 n=5+4)
LastIndexAnyASCII/16:64-48    160ns ± 1%    161ns ± 1%     ~     (p=0.325 n=5+5)
LastIndexAnyASCII/256:1-48    300ns ± 0%    301ns ± 0%   +0.33%  (p=0.008 n=5+5)
LastIndexAnyASCII/256:2-48    304ns ± 0%    304ns ± 0%     ~     (p=1.000 n=5+5)
LastIndexAnyASCII/256:4-48    311ns ± 0%    311ns ± 0%     ~     (p=0.556 n=4+5)
LastIndexAnyASCII/256:8-48    320ns ± 0%    321ns ± 0%     ~     (p=0.143 n=5+5)
LastIndexAnyASCII/256:16-48   333ns ± 0%    335ns ± 0%   +0.60%  (p=0.029 n=4+4)
LastIndexAnyASCII/256:32-48   367ns ± 0%    366ns ± 0%     ~     (p=0.095 n=4+5)
LastIndexAnyASCII/256:64-48   431ns ± 0%    424ns ± 0%   -1.62%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:1-48      19.7ns ± 1%   11.9ns ± 0%  -39.47%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:2-48      27.6ns ± 1%   11.9ns ± 0%  -56.82%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:4-48      29.9ns ± 0%   11.9ns ± 0%     ~     (p=0.079 n=4+5)
LastIndexAnyUTF8/1:8-48      48.7ns ± 0%   11.9ns ± 0%  -75.54%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:16-48     57.8ns ± 0%   11.4ns ± 0%  -80.26%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:32-48     94.7ns ± 0%   12.2ns ± 0%  -87.07%  (p=0.008 n=5+5)
LastIndexAnyUTF8/1:64-48      163ns ± 0%     13ns ± 1%  -91.93%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:1-48      258ns ± 0%     88ns ± 0%  -65.76%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:2-48      400ns ± 0%    162ns ± 0%  -59.38%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:4-48      415ns ± 0%    162ns ± 0%  -60.87%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:8-48      737ns ± 0%    162ns ± 0%  -78.02%  (p=0.000 n=5+4)
LastIndexAnyUTF8/16:16-48     882ns ± 0%    128ns ± 0%  -85.49%  (p=0.008 n=5+5)
LastIndexAnyUTF8/16:32-48    1.47µs ± 0%   0.16µs ± 0%  -89.29%  (p=0.000 n=4+5)
LastIndexAnyUTF8/16:64-48    2.56µs ± 0%   0.14µs ± 0%  -94.41%  (p=0.016 n=5+4)
LastIndexAnyUTF8/256:1-48    3.60µs ± 0%   1.23µs ± 0%  -65.67%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:2-48    5.78µs ± 0%   2.18µs ± 0%  -62.32%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:4-48    6.26µs ± 0%   2.18µs ± 0%  -65.15%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:8-48    11.2µs ± 0%    2.2µs ± 0%  -80.53%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:16-48   13.5µs ± 0%    1.9µs ± 0%  -86.02%  (p=0.016 n=4+5)
LastIndexAnyUTF8/256:32-48   23.0µs ± 0%    2.1µs ± 0%  -90.72%  (p=0.008 n=5+5)
LastIndexAnyUTF8/256:64-48   40.5µs ± 0%    2.1µs ± 0%  -94.73%  (p=0.008 n=5+5)

Change-Id: Ie05e306f8b184b989701868cb161ce8b3f18203b
Reviewed-on: https://go-review.googlesource.com/c/go/+/156998
Run-TryBot: eric fang <eric.fang@arm.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-11 05:13:13 +00:00
erifan01 18a6fd44bb bytes, strings: moves indexRabinKarp function to internal/bytealg
In order to facilitate optimization of IndexAny and LastIndexAny, this patch moves
three Rabin-Karp related functions indexRabinKarp, hashStr and hashStrRev in strings
package to initernal/bytealg. There are also three functions in the bytes package with
the same names and functions but different parameter types. To highlight this, this
patch also moves them to internal/bytealg and gives them slightly different names.

Related benchmark changes on amd64 and arm64:

name          old time/op    new time/op    delta
pkg:strings goos:linux goarch:amd64
Index-16        14.0ns ± 1%    14.1ns ± 2%    ~     (p=0.738 n=5+5)
LastIndex-16    15.5ns ± 1%    15.7ns ± 4%    ~     (p=0.897 n=5+5)
pkg:bytes goos:linux goarch:amd64
Index/10-16     26.5ns ± 1%    26.5ns ± 0%    ~     (p=0.873 n=5+5)
Index/32-16     26.2ns ± 0%    25.7ns ± 0%  -1.68%  (p=0.008 n=5+5)
Index/4K-16     5.12µs ± 4%    5.14µs ± 2%    ~     (p=0.841 n=5+5)
Index/4M-16     5.44ms ± 3%    5.34ms ± 2%    ~     (p=0.056 n=5+5)
Index/64M-16    85.8ms ± 3%    84.6ms ± 0%  -1.37%  (p=0.016 n=5+5)

name          old speed      new speed      delta
pkg:bytes goos:linux goarch:amd64
Index/10-16    377MB/s ± 1%   377MB/s ± 0%    ~     (p=1.000 n=5+5)
Index/32-16   1.22GB/s ± 1%  1.24GB/s ± 0%  +1.66%  (p=0.008 n=5+5)
Index/4K-16    800MB/s ± 4%   797MB/s ± 2%    ~     (p=0.841 n=5+5)
Index/4M-16    771MB/s ± 3%   786MB/s ± 2%    ~     (p=0.056 n=5+5)
Index/64M-16   783MB/s ± 3%   793MB/s ± 0%  +1.36%  (p=0.016 n=5+5)

name         old time/op   new time/op   delta
pkg:strings goos:linux goarch:arm64
Index-8       22.6ns ± 0%   22.5ns ± 0%    ~     (p=0.167 n=5+5)
LastIndex-8   17.5ns ± 0%   17.5ns ± 0%    ~     (all equal)
pkg:bytes goos:linux goarch:arm64
Index/10-8    25.0ns ± 0%   25.0ns ± 0%    ~     (all equal)
Index/32-8     160ns ± 0%    160ns ± 0%    ~     (all equal)
Index/4K-8    6.26µs ± 0%   6.26µs ± 0%    ~     (p=0.167 n=5+5)
Index/4M-8    6.30ms ± 0%   6.31ms ± 0%    ~     (p=1.000 n=5+5)
Index/64M-8    101ms ± 0%    101ms ± 0%    ~     (p=0.690 n=5+5)

name         old speed     new speed     delta
pkg:bytes goos:linux goarch:arm64
Index/10-8   399MB/s ± 0%  400MB/s ± 0%  +0.08%  (p=0.008 n=5+5)
Index/32-8   200MB/s ± 0%  200MB/s ± 0%    ~     (p=0.127 n=4+5)
Index/4K-8   654MB/s ± 0%  654MB/s ± 0%  +0.01%  (p=0.016 n=5+5)
Index/4M-8   665MB/s ± 0%  665MB/s ± 0%    ~     (p=0.833 n=5+5)
Index/64M-8  665MB/s ± 0%  665MB/s ± 0%    ~     (p=0.913 n=5+5)

Change-Id: Icce3bc162bb8613ac36dc963a46c51f8e82ab842
Reviewed-on: https://go-review.googlesource.com/c/go/+/208638
Run-TryBot: eric fang <eric.fang@arm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-03-04 17:36:05 +00:00
Andrew Medvedev 78e5288b5c strings, bytes: clarify usage of EqualFolds
This clarifies meaning of "case folding" Unicode equality with more familiar "case insensitive" wording.
For case folding properties see ftp://ftp.unicode.org/Public/UNIDATA/CaseFolding.txt.

Fixes #33447

Change-Id: I6ee85ab398679bf2a0b7d18693985ff0979d6c5a
GitHub-Last-Rev: accc915933
GitHub-Pull-Request: golang/go#34434
Reviewed-on: https://go-review.googlesource.com/c/go/+/196717
Reviewed-by: Rob Pike <r@golang.org>
2019-09-21 21:45:58 +00:00
Martin Möhrmann 3259bc4419 strings, bytes: add ToValidUTF8
The newly added functions create a copy of their input with all bytes in
invalid UTF-8 byte sequences mapped to the UTF-8 byte sequence
given as replacement parameter.

Fixes #25805

Change-Id: Iaf65f65b40c0581c6bb000f1590408d6628321d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/142003
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-01 18:31:47 +00:00
Josh Bleecher Snyder ca0c449a6b bytes, internal/bytealg: simplify Equal
The compiler has advanced enough that it is cheaper
to convert to strings than to go through the assembly
trampolines to call runtime.memequal.

Simplify Equal accordingly, and cull dead code from bytealg.

While we're here, simplify Equal's documentation.

Fixes #31587

Change-Id: Ie721d33f9a6cbd86b1d873398b20e7882c2c63e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/173323
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-24 00:56:36 +00:00
Tobias Klauser 08e1823a63 bytes: optimize ToLower and ToUpper for ASCII-only case
Follow what CL 68370 and CL 76470 did for the respective functions in
package strings.

Also adjust godoc strings to match the respective strings functions and
mention the special case for ASCII-only byte slices which don't need
conversion.

name                                       old time/op  new time/op  delta
ToUpper/#00-8                              9.35ns ± 3%  6.08ns ± 2%  -35.04%  (p=0.000 n=9+9)
ToUpper/ONLYUPPER-8                        77.7ns ± 1%  16.9ns ± 2%  -78.22%  (p=0.000 n=10+10)
ToUpper/abc-8                              36.5ns ± 1%  22.1ns ± 1%  -39.43%  (p=0.000 n=10+8)
ToUpper/AbC123-8                           56.9ns ± 2%  28.2ns ± 2%  -50.54%  (p=0.000 n=8+10)
ToUpper/azAZ09_-8                          62.3ns ± 1%  26.9ns ± 1%  -56.82%  (p=0.000 n=9+10)
ToUpper/longStrinGwitHmixofsmaLLandcAps-8   219ns ± 2%    63ns ± 2%  -71.17%  (p=0.000 n=10+10)
ToUpper/longɐstringɐwithɐnonasciiⱯchars-8   367ns ± 2%   374ns ± 3%   +2.05%  (p=0.000 n=9+10)
ToUpper/ɐɐɐɐɐ-8                             200ns ± 1%   206ns ± 1%   +2.49%  (p=0.000 n=10+10)
ToUpper/a\u0080\U0010ffff-8                90.4ns ± 1%  93.8ns ± 0%   +3.82%  (p=0.000 n=10+7)
ToLower/#00-8                              9.59ns ± 1%  6.13ns ± 2%  -36.08%  (p=0.000 n=10+10)
ToLower/abc-8                              36.4ns ± 1%  10.4ns ± 1%  -71.50%  (p=0.000 n=10+10)
ToLower/AbC123-8                           55.8ns ± 1%  27.5ns ± 1%  -50.61%  (p=0.000 n=10+10)
ToLower/azAZ09_-8                          61.7ns ± 1%  30.2ns ± 1%  -50.98%  (p=0.000 n=8+10)
ToLower/longStrinGwitHmixofsmaLLandcAps-8   226ns ± 1%    64ns ± 1%  -71.53%  (p=0.000 n=10+9)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-8   354ns ± 0%   361ns ± 0%   +2.18%  (p=0.000 n=10+10)
ToLower/ⱭⱭⱭⱭⱭ-8                             180ns ± 1%   186ns ± 0%   +3.45%  (p=0.000 n=10+9)
ToLower/A\u0080\U0010ffff-8                91.7ns ± 0%  94.5ns ± 0%   +2.99%  (p=0.000 n=10+10)

Change-Id: Ifdb8ae328ff9feacd1c170db8eebbf98c399e204
Reviewed-on: https://go-review.googlesource.com/c/go/+/170954
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-09 05:45:34 +00:00
Ben Hoyt f24e1099cb bytes: make TrimSpace return nil on all-space input
Issue #29122 introduced a subtle regression due to the way that
TrimFuncLeft is written: previously TrimSpace returned nil when given
an input of all whitespace, but with the #29122 changes it returned an
empty slice on all-space input.

This change adds a special case to the new, optimized TrimSpace to go
back to that behavior. While it is odd behavior and people shouldn't be
relying on these functions returning a nil slice in practice, it's not
worth the breakage of code that does.

This tweak doesn't change the TrimSpace benchmarks significantly.

Fixes #31038

Change-Id: Idb495d02b474054d2b2f593c2e318a7a6625688a
Reviewed-on: https://go-review.googlesource.com/c/go/+/169518
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-27 13:52:52 +00:00
Ben Hoyt 4b4f222a0d bytes, strings: speed up TrimSpace 4-5x for common ASCII cases
This change adds a fast path for ASCII strings to both
strings.TrimSpace and bytes.TrimSpace. It doesn't slow down the
non-ASCII path much, if at all.

I added benchmarks for strings.TrimSpace as it didn't have any, and
I fleshed out the benchmarks for bytes.TrimSpace as it just had one
case (for ASCII). The benchmarks (and the code!) are now the same
between the two versions. Below are the benchmark results:

strings.TrimSpace:

name                      old time/op  new time/op  delta
TrimSpace/NoTrim-8        18.6ns ± 0%   3.8ns ± 0%  -79.53%  (p=0.000 n=5+4)
TrimSpace/ASCII-8         33.5ns ± 2%   6.0ns ± 3%  -82.05%  (p=0.008 n=5+5)
TrimSpace/SomeNonASCII-8  97.1ns ± 1%  88.6ns ± 1%   -8.68%  (p=0.008 n=5+5)
TrimSpace/JustNonASCII-8   144ns ± 0%   143ns ± 0%     ~     (p=0.079 n=4+5)

bytes.TrimSpace:

name                      old time/op  new time/op  delta
TrimSpace/NoTrim-8        18.9ns ± 1%   4.1ns ± 1%  -78.34%  (p=0.008 n=5+5)
TrimSpace/ASCII-8         29.9ns ± 0%   6.3ns ± 1%  -79.06%  (p=0.008 n=5+5)
TrimSpace/SomeNonASCII-8  91.5ns ± 0%  82.3ns ± 0%  -10.03%  (p=0.008 n=5+5)
TrimSpace/JustNonASCII-8   150ns ± 0%   150ns ± 0%     ~     (all equal)

Fixes #29122

Change-Id: Ica45cd86a219cadf60173ec9db260133cd1d7951
Reviewed-on: https://go-review.googlesource.com/c/go/+/152917
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-12 15:52:17 +00:00
Tobias Klauser 0e9d7d430b bytes: return early in Repeat if count is 0
This matches the implementation of strings.Repeat and slightly increases
performance:

name      old time/op  new time/op  delta
Repeat-8   145ns ±12%   125ns ±29%  -13.35%  (p=0.009 n=10+10)

Change-Id: Ic0a0e2ea9e36591286a49def320ddb67fe0b2c50
Reviewed-on: https://go-review.googlesource.com/c/go/+/166399
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-09 14:17:13 +00:00
Tobias Klauser ce7534ff06 bytes: use Rabin-Karp algorithm for LastIndex
Implement LastIndex using the Rabin-Karp algorithm akin to
strings.LastIndex

name              old time/op  new time/op  delta
LastIndexHard1-8  3.16ms ± 1%  1.44ms ± 0%  -54.35%  (p=0.008 n=5+5)
LastIndexHard2-8  3.17ms ± 1%  1.45ms ± 0%  -54.27%  (p=0.008 n=5+5)
LastIndexHard3-8  3.05ms ± 1%  1.44ms ± 1%  -52.58%  (p=0.008 n=5+5)

Change-Id: Ie8ddd179cd84dfa00e3e4e2327ef932975c88670
Reviewed-on: https://go-review.googlesource.com/c/go/+/166258
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-08 13:46:43 +00:00
Keith Randall ad4a58e315 strings,bytes: use inlineable function trampolines instead of linkname
Cleans things up quite a bit.

There's still a few more, like runtime.cmpstring, which might also
be worth fixing.

Change-Id: Ide18dd621efc129cc686db223f47fa0b044b5580
Reviewed-on: https://go-review.googlesource.com/c/148578
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-11-08 20:52:47 +00:00
Brad Fitzpatrick ebdc0b8d68 bytes, strings: add ReplaceAll
Credit to Harald Nordgren for the proposal in
https://golang.org/cl/137456 and #27864.

Fixes #27864

Change-Id: I80546683b0623124fe4627a71af88add2f6c1c27
Reviewed-on: https://go-review.googlesource.com/137855
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-09-26 20:51:23 +00:00
erifan01 691f5c34ad strings, bytes: optimize function Index
This change compares the first two characters instead of the first one,
and if they match, the entire string is compared. Comparing the first two
characters helps to filter out the case where the first character matches
but the subsequent characters do not match, thereby improving the substring
search speed in this case.

Benchmarks with no effect or minimal impact (less than 5%) is not listed,
the following are improved benchmarks:
On arm64:
strings:
IndexPeriodic/IndexPeriodic16-8   172890.00ns +- 2%   124156.20ns +- 0%  -28.19%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-8    78092.80ns +- 0%    65138.60ns +- 0%  -16.59%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-8    42322.20ns +- 0%    34661.60ns +- 0%  -18.10%  (p=0.008 n=5+5)
bytes:
IndexPeriodic/IndexPeriodic16-8     183468.20ns +- 6%     123759.00ns +- 0%  -32.54%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-8      84776.40ns +- 0%      63907.80ns +- 0%  -24.62%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-8      45835.60ns +- 0%      34194.20ns +- 0%  -25.40%  (p=0.008 n=5+5)

On amd64:
strings:
IndexPeriodic/IndexPeriodic8-16    219499.00ns +- 0%   178123.40ns +- 0%  -18.85%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic16-16   109760.20ns +- 0%    88957.80ns +- 0%  -18.95%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-16    54943.00ns +- 0%    44573.80ns +- 0%  -18.87%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-16    29804.80ns +- 0%    24417.80ns +- 0%  -18.07%  (p=0.008 n=5+5)
bytes:
IndexPeriodic/IndexPeriodic8-16     226592.60ns +- 0%    181183.20ns +- 0%  -20.04%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic16-16    111432.60ns +- 0%     90634.60ns +- 0%  -18.66%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-16     55640.60ns +- 0%     45433.00ns +- 0%  -18.35%  (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-16     30833.00ns +- 0%     24784.20ns +- 0%  -19.62%  (p=0.008 n=5+5)

Change-Id: I2d9e7e138d29e960d20a203eb74dc2ec976a9d71
Reviewed-on: https://go-review.googlesource.com/131177
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-09-13 16:21:55 +00:00
Johan Brandhorst 841a9136b3 strings, bytes: avoid unnecessary function literals
A number of explicit function literals found through the
unlambda linter are removed.

Fixes #26802

Change-Id: I0b122bdd95e9cb804c77efe20483fdf681c8154e
Reviewed-on: https://go-review.googlesource.com/127756
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-08-22 16:09:06 +00:00
Eric Pauley 9d11c63b64 bytes, strings: improve EqualFold fast version for ASCII
The existing implementation only considers the special ASCII
case when the lower character is an upper case letter. This
means that most ASCII comparisons use unicode.SimpleFold even
when it is not necessary.

benchmark                old ns/op     new ns/op     delta
BenchmarkEqualFold-8     450           390           -13.33%

Change-Id: I735ca3c30fc0145c186d2a54f31fd39caab2c3fa
Reviewed-on: https://go-review.googlesource.com/110018
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-01 18:52:19 +00:00
Keith Randall ee58eccc56 internal/bytealg: move short string Index implementations into bytealg
Also move the arm64 CountByte implementation while we're here.

Fixes #19792

Change-Id: I1e0fdf1e03e3135af84150a2703b58dad1b0d57e
Reviewed-on: https://go-review.googlesource.com/98518
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-04 19:49:44 +00:00
Keith Randall 45964e4f9c internal/bytealg: move Count to bytealg
Move bytes.Count and strings.Count to bytealg.

Update #19792

Change-Id: I3e4e14b504a0b71758885bb131e5656e342cf8cb
Reviewed-on: https://go-review.googlesource.com/98495
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-04 17:49:25 +00:00