This change adds a Square root method to the big.Float type, with
signature

  (z *Float) Sqrt(x *Float) *Float

Fixes #20460

Change-Id: I050aaed0615fe0894e11c800744600648343c223
Reviewed-on: https://go-review.googlesource.com/67830
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: I3141076c0db7b70ea408c941a857ed1f82dcb2df
Reviewed-on: https://go-review.googlesource.com/73557Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>

Both the linker and the plugin package were inconsistent
about when they applied the path encoding defined in
objabi.PathToPrefix. As a result, only some symbols from
a package path that required encoding were being found.

So always encoding the path.

Fixes #22295

Change-Id: Ife86c79ca20b2e9307008ed83885e193d32b7dc4
Reviewed-on: https://go-review.googlesource.com/72390
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

MOVBS/MOVBU/MOVHS/MOVHU can be optimized with a single instruction
on ARMv6 and ARMv7, instead of a pair of left/right shifts.

The benchmark tests show big improvement in special cases and a little
improvement in total.

1. A special case gets about 29% improvement.
name                     old time/op    new time/op    delta
TypePro-4                  3.81ms ± 1%    2.71ms ± 1%  -28.97%  (p=0.000 n=26+25)
The source code of this case can be found at
https://github.com/benshi001/ugo1/blob/master/typepromotion_test.go

2. There is a little improvement in the go1 benchmark, excluding the noise.
name                     old time/op    new time/op    delta
BinaryTree17-4              42.1s ± 3%     42.1s ± 2%    ~     (p=0.883 n=28+30)
Fannkuch11-4                24.3s ± 4%     24.7s ± 7%  +1.64%  (p=0.026 n=30+30)
FmtFprintfEmpty-4           833ns ± 2%     835ns ± 2%    ~     (p=0.371 n=26+28)
FmtFprintfString-4         1.36µs ± 3%    1.35µs ± 1%    ~     (p=0.202 n=26+23)
FmtFprintfInt-4            1.42µs ± 3%    1.43µs ± 1%  +0.66%  (p=0.000 n=26+27)
FmtFprintfIntInt-4         2.10µs ± 1%    2.10µs ± 2%    ~     (p=0.104 n=25+26)
FmtFprintfPrefixedInt-4    2.37µs ± 2%    2.33µs ± 1%  -1.75%  (p=0.000 n=25+28)
FmtFprintfFloat-4          4.50µs ± 0%    4.37µs ± 1%  -2.81%  (p=0.000 n=23+25)
FmtManyArgs-4              8.08µs ± 0%    8.13µs ± 3%    ~     (p=0.160 n=23+26)
GobDecode-4                 102ms ± 4%     103ms ± 4%  +1.08%  (p=0.001 n=28+26)
GobEncode-4                96.0ms ± 2%    95.2ms ± 3%  -0.81%  (p=0.000 n=24+25)
Gzip-4                      4.17s ± 3%     4.11s ± 2%  -1.45%  (p=0.000 n=25+25)
Gunzip-4                    597ms ± 2%     594ms ± 2%  -0.57%  (p=0.000 n=24+26)
HTTPClientServer-4          708µs ± 4%     708µs ± 4%    ~     (p=0.852 n=28+28)
JSONEncode-4                241ms ± 1%     245ms ± 3%  +1.62%  (p=0.000 n=27+28)
JSONDecode-4                906ms ± 3%     889ms ± 3%  -1.85%  (p=0.000 n=23+24)
Mandelbrot200-4            41.8ms ± 1%    41.8ms ± 1%    ~     (p=0.929 n=25+24)
GoParse-4                  47.1ms ± 2%    45.3ms ± 4%  -3.80%  (p=0.000 n=28+24)
RegexpMatchEasy0_32-4      1.27µs ± 2%    1.28µs ± 1%  +0.77%  (p=0.000 n=26+28)
RegexpMatchEasy0_1K-4      8.08µs ± 9%    7.83µs ±10%  -3.10%  (p=0.012 n=26+26)
RegexpMatchEasy1_32-4      1.29µs ± 5%    1.29µs ± 2%    ~     (p=0.301 n=26+29)
RegexpMatchEasy1_1K-4      10.5µs ± 4%    10.3µs ± 5%  -1.95%  (p=0.003 n=26+26)
RegexpMatchMedium_32-4     1.94µs ± 1%    1.95µs ± 1%    ~     (p=0.251 n=24+27)
RegexpMatchMedium_1K-4      502µs ± 2%     502µs ± 2%    ~     (p=0.336 n=25+28)
RegexpMatchHard_32-4       26.7µs ± 1%    26.6µs ± 3%    ~     (p=0.454 n=27+26)
RegexpMatchHard_1K-4        801µs ± 3%     799µs ± 2%    ~     (p=0.097 n=24+26)
Revcomp-4                  73.5ms ± 5%    73.2ms ± 3%    ~     (p=0.240 n=26+26)
Template-4                  1.07s ± 2%     1.05s ± 1%  -2.39%  (p=0.000 n=26+24)
TimeParse-4                6.87µs ± 1%    6.85µs ± 1%    ~     (p=0.094 n=28+23)
TimeFormat-4               13.4µs ± 1%    13.4µs ± 1%    ~     (p=0.664 n=25+29)
[Geo mean]                  717µs          713µs       -0.54%

name                     old speed      new speed      delta
GobDecode-4              7.52MB/s ± 4%  7.44MB/s ± 4%  -1.10%  (p=0.001 n=28+26)
GobEncode-4              7.99MB/s ± 2%  8.06MB/s ± 3%  +0.81%  (p=0.000 n=24+25)
Gzip-4                   4.66MB/s ± 3%  4.72MB/s ± 2%  +1.43%  (p=0.000 n=25+25)
Gunzip-4                 32.5MB/s ± 2%  32.7MB/s ± 2%  +0.56%  (p=0.001 n=24+26)
JSONEncode-4             8.04MB/s ± 1%  7.92MB/s ± 3%  -1.59%  (p=0.000 n=27+28)
JSONDecode-4             2.14MB/s ± 3%  2.18MB/s ± 3%  +1.90%  (p=0.000 n=23+24)
GoParse-4                1.23MB/s ± 3%  1.28MB/s ± 4%  +4.23%  (p=0.000 n=30+24)
RegexpMatchEasy0_32-4    25.2MB/s ± 2%  25.0MB/s ± 1%  -0.76%  (p=0.000 n=26+28)
RegexpMatchEasy0_1K-4     127MB/s ± 8%   131MB/s ± 9%  +3.29%  (p=0.012 n=26+26)
RegexpMatchEasy1_32-4    24.8MB/s ± 5%  24.8MB/s ± 2%    ~     (p=0.339 n=26+29)
RegexpMatchEasy1_1K-4    97.9MB/s ± 4%  99.8MB/s ± 5%  +1.98%  (p=0.004 n=26+26)
RegexpMatchMedium_32-4    514kB/s ± 3%   515kB/s ± 3%    ~     (p=0.391 n=28+28)
RegexpMatchMedium_1K-4   2.04MB/s ± 2%  2.04MB/s ± 2%    ~     (p=0.517 n=25+28)
RegexpMatchHard_32-4     1.20MB/s ± 3%  1.20MB/s ± 3%    ~     (p=0.203 n=28+28)
RegexpMatchHard_1K-4     1.28MB/s ± 3%  1.28MB/s ± 2%    ~     (p=0.499 n=24+26)
Revcomp-4                34.6MB/s ± 4%  34.7MB/s ± 3%    ~     (p=0.245 n=26+26)
Template-4               1.81MB/s ± 2%  1.85MB/s ± 3%  +2.30%  (p=0.000 n=26+25)
[Geo mean]               6.82MB/s       6.88MB/s       +0.84%

fixes #20653

Change-Id: Ief0d6e726e517e51ae511325b21ee72598e759ff
Reviewed-on: https://go-review.googlesource.com/71992Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

For #9060.

Change-Id: Ibd0f047083f3c98cec96c655a3e2024df8e1d2a0
Reviewed-on: https://go-review.googlesource.com/73554Reviewed-by: Ian Lance Taylor <iant@golang.org>

...because that's an illegal addressing mode.

I double-checked handling of this code, and 387 is the only
place where this check is missing.

Fixes #22429

Change-Id: I2284fe729ea86251c6af2f04076ddf7a5e66367c
Reviewed-on: https://go-review.googlesource.com/73551
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

drawPaletted has to discover R,G,B,A color values of each source image
pixel in a given rectangle. Doing that by calling image.Image.At()
method returning color.Color interface is quite taxing allocation-wise
since interface values go through heap. Introduce special cases for some
concrete source types by fetching color values using type-specific
methods.

name        old time/op    new time/op    delta
Paletted-4    7.62ms ± 4%    3.72ms ± 3%   -51.20%  (p=0.008 n=5+5)

name        old alloc/op   new alloc/op   delta
Paletted-4     480kB ± 0%       0kB ± 0%   -99.99%  (p=0.000 n=4+5)

name        old allocs/op  new allocs/op  delta
Paletted-4      120k ± 0%        0k ± 0%  -100.00%  (p=0.008 n=5+5)

Updates #15759.

Change-Id: I0ce1770ff600ac80599541aaad4c2c826855c8fb
Reviewed-on: https://go-review.googlesource.com/72370Reviewed-by: Nigel Tao <nigeltao@golang.org>

A method expression is of the form T.m where T is a type and m
is a method of that type. The spec restricted T essentially to
a type name. Both cmd/compile and go/types accepted any type
syntactically, and a method expression was really just a form
of a selector expression x.f where x denotes a type.

This CL removes the spec syntax restriction from MethodExpr
to match the actual implementation. It also moves MethodExpr
from Operand to PrimaryExpr, because that's what it is.

It still keeps the separate notion of MethodExpr even though
it looks just like a selector expresion, since a MethodExpr
must start with a type rather than a value, and the spec's
syntax expresses this bit of semantics via distinct productions
(e.g., conversions look like calls but also must start with
a type).

Fixes #9060.

Change-Id: Idd84655b5b4f85d7ee53ebf749f73f0414a05f4a
Reviewed-on: https://go-review.googlesource.com/73233Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Not perfect, but it's a start.

Change-Id: I3283385223a39ea73567b0130290bfe4de69d018
Reviewed-on: https://go-review.googlesource.com/73552Reviewed-by: Robert Griesemer <gri@golang.org>

CL 39570 added support for automatically setting flag bit 11 to
indicate that the filename and comment fields are encoded in UTF-8,
which is (conventionally) the encoding using for most Go strings.

However, the detection added is too lose for two reasons:
* We need to ensure both fields are at least possibly UTF-8.
That is, if any field is definitely not UTF-8, then we can't set the bit.
* The utf8.ValidRune returns true for utf8.RuneError, which iterating
over a Go string automatically returns for invalid UTF-8.
Thus, we manually check for that value.

Updates #22367
Updates #10741

Change-Id: Ie8aae388432e546e44c6bebd06a00434373ca99e
Reviewed-on: https://go-review.googlesource.com/72791Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

CL 40112 intended to allow full flag processing in go vet, but missed
vet's -shift flag; this corrects the omission.

Fixes #22442

Change-Id: I47525018306bd8b9aa452fb378d0d45319f8cf11
Reviewed-on: https://go-review.googlesource.com/73553
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Replace any nested Writer that is a MultiWriter with its associated
Writers.

Fixes #22431

Change-Id: Ida7c4c83926363c1780689e216cf0c5241a5b8eb
Reviewed-on: https://go-review.googlesource.com/73470
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This test was previously disabled when external linking was
unsupported on ppc64le. It should still be disabled on ppc64
since there is no cgo or external linking there, but I removed
the if test for GOARCH=ppc64 since the initial test for cgo
enabled will cause it to be skipped on ppc64.

Fixes #22360

Change-Id: I5a0e3e4a1bd71ac7bf0ed0c792f7b78fb4a5e100
Reviewed-on: https://go-review.googlesource.com/73510
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This adds a Noop() function to the net/stmp client.

It allows for testing if a connaction is still healthy.

Fixes #22321

Change-Id: I023b613b1536ea21274cc36d41f5720c9bbdecbc
Reviewed-on: https://go-review.googlesource.com/71650
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This change adds the syscall.Conn interface to Listener types, with the caveat that only RawConn.Control is supported. Custom socket options can now be set safely.

Updates #19435
Fixes #22065

Change-Id: I7e74780d00318dc54a923d1c628a18a36009acab
Reviewed-on: https://go-review.googlesource.com/71651
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Previously scanning time.Time into a *time.Time required reflection.
Now it does not. Scanning already checked if the source value was of
type time.Time. The only addition was checking the destination was
of type *time.Time.

Existing tests already scan time.Time into *time.Time, so no new
tests were added. Linked issue has performance justification.

Fixes #22300

Change-Id: I4eea461c78fad71ce76e7677c8503a1919666931
Reviewed-on: https://go-review.googlesource.com/73232
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Add SetDeadline, SetReadDeadline, and SetWriteDeadline methods to os.File,
just as they exist today for the net package.

Fixes #22114

Change-Id: I4d390d739169b991175baba676010897dc8568fa
Reviewed-on: https://go-review.googlesource.com/71770
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

Russ pointed out in a previous CL golang.org/cl/65731 that not only
was the locking incomplete, previous changes did not correctly
lock driver calls in other sections. After inspecting
driverConn, driverStmt, driverResult, Tx, and Rows structs
where driver interfaces are stored, I discovered a few more places
that failed to lock driver calls. The largest of these
was the parameter type converter "driverArgs".

driverArgs was typically called right before another call to the
driver in a locked region, so I made the entire driverArgs expect
a locked driver mutex and combined the region. This should not
be a problem because the connection is pulled out of the connection
pool either way so there shouldn't be contention.

Fixes #21117

Change-Id: I88d46f74dca25fb11a30f0bf8e79785a73133d23
Reviewed-on: https://go-review.googlesource.com/71433
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Otherwise low-res timers cause problems at call sites that expect to
be able to use 0 as meaning "no time set" and therefore expect that
nanotime never returns 0 itself. For example, sched.lastpoll == 0
means no last poll.

Fixes #22394.

Change-Id: Iea28acfddfff6f46bc90f041ec173e0fea591285
Reviewed-on: https://go-review.googlesource.com/73410
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I7d63e747e798d588bdcf2b79b6ecd21fce7bbc9c
Reviewed-on: https://go-review.googlesource.com/73391
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>

Change-Id: I9241e6acb65c337b961eed9cdeaf4c041b6326a3
Reviewed-on: https://go-review.googlesource.com/73390
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>

Fixes #20918.

Change-Id: I84306242084631bbe7a9adc839f92e72ac1a3e75
Reviewed-on: https://go-review.googlesource.com/73331
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Use SIMD instructions when comparing chunks bigger than 16 bytes.
Benchmark results of bytes:

name                 old time/op    new time/op    delta
Equal/0-8              6.52ns ± 1%    5.51ns ± 0%   -15.43%  (p=0.000 n=8+9)
Equal/1-8              11.5ns ± 0%    10.5ns ± 0%    -8.70%  (p=0.000 n=10+10)
Equal/6-8              19.0ns ± 0%    13.5ns ± 0%   -28.95%  (p=0.000 n=10+10)
Equal/9-8              31.0ns ± 0%    13.5ns ± 0%   -56.45%  (p=0.000 n=10+10)
Equal/15-8             40.0ns ± 0%    15.5ns ± 0%   -61.25%  (p=0.000 n=10+10)
Equal/16-8             41.5ns ± 0%    14.5ns ± 0%   -65.06%  (p=0.000 n=10+10)
Equal/20-8             47.5ns ± 0%    17.0ns ± 0%   -64.21%  (p=0.000 n=10+10)
Equal/32-8             65.6ns ± 0%    17.0ns ± 0%   -74.09%  (p=0.000 n=10+10)
Equal/4K-8             6.17µs ± 0%    0.57µs ± 1%   -90.76%  (p=0.000 n=10+10)
Equal/4M-8             6.41ms ± 0%    1.11ms ±14%   -82.71%  (p=0.000 n=8+10)
Equal/64M-8             104ms ± 0%      33ms ± 0%   -68.64%  (p=0.000 n=10+10)
EqualPort/1-8          13.0ns ± 0%    13.0ns ± 0%      ~     (all equal)
EqualPort/6-8          22.0ns ± 0%    22.7ns ± 0%    +3.06%  (p=0.000 n=8+9)
EqualPort/32-8         78.1ns ± 0%    78.1ns ± 0%      ~     (all equal)
EqualPort/4K-8         7.54µs ± 0%    7.61µs ± 0%    +0.92%  (p=0.000 n=10+8)
EqualPort/4M-8         8.16ms ± 2%    8.05ms ± 1%    -1.31%  (p=0.023 n=10+10)
EqualPort/64M-8         142ms ± 0%     142ms ± 0%    +0.37%  (p=0.000 n=10+10)
CompareBytesEqual-8    39.0ns ± 0%    41.6ns ± 2%    +6.67%  (p=0.000 n=9+10)

name                 old speed      new speed      delta
Equal/1-8            86.9MB/s ± 0%  95.2MB/s ± 0%    +9.53%  (p=0.000 n=8+8)
Equal/6-8             315MB/s ± 0%   444MB/s ± 0%   +40.74%  (p=0.000 n=9+10)
Equal/9-8             290MB/s ± 0%   666MB/s ± 0%  +129.63%  (p=0.000 n=8+10)
Equal/15-8            375MB/s ± 0%   967MB/s ± 0%  +158.09%  (p=0.000 n=10+10)
Equal/16-8            385MB/s ± 0%  1103MB/s ± 0%  +186.24%  (p=0.000 n=10+9)
Equal/20-8            421MB/s ± 0%  1175MB/s ± 0%  +179.44%  (p=0.000 n=9+10)
Equal/32-8            488MB/s ± 0%  1881MB/s ± 0%  +285.34%  (p=0.000 n=10+8)
Equal/4K-8            664MB/s ± 0%  7181MB/s ± 1%  +981.32%  (p=0.000 n=10+10)
Equal/4M-8            654MB/s ± 0%  3822MB/s ±16%  +484.15%  (p=0.000 n=8+10)
Equal/64M-8           645MB/s ± 0%  2056MB/s ± 0%  +218.90%  (p=0.000 n=10+10)
EqualPort/1-8        76.8MB/s ± 0%  76.7MB/s ± 0%    -0.09%  (p=0.023 n=10+10)
EqualPort/6-8         272MB/s ± 0%   264MB/s ± 0%    -2.94%  (p=0.000 n=8+10)
EqualPort/32-8        410MB/s ± 0%   410MB/s ± 0%    +0.01%  (p=0.004 n=9+10)
EqualPort/4K-8        543MB/s ± 0%   538MB/s ± 0%    -0.91%  (p=0.000 n=9+9)
EqualPort/4M-8        514MB/s ± 2%   521MB/s ± 1%    +1.31%  (p=0.023 n=10+10)
EqualPort/64M-8       473MB/s ± 0%   472MB/s ± 0%    -0.37%  (p=0.000 n=10+10)

Benchmark results of go1:

name                     old time/op    new time/op    delta
BinaryTree17-8              6.53s ± 0%     6.52s ± 2%    ~     (p=0.286 n=4+5)
Fannkuch11-8                6.35s ± 1%     6.33s ± 0%    ~     (p=0.690 n=5+5)
FmtFprintfEmpty-8           108ns ± 1%      99ns ± 1%  -8.31%  (p=0.008 n=5+5)
FmtFprintfString-8          172ns ± 1%     188ns ± 0%  +9.43%  (p=0.016 n=5+4)
FmtFprintfInt-8             207ns ± 0%     202ns ± 0%  -2.42%  (p=0.008 n=5+5)
FmtFprintfIntInt-8          277ns ± 1%     271ns ± 1%  -2.02%  (p=0.008 n=5+5)
FmtFprintfPrefixedInt-8     386ns ± 0%     380ns ± 0%  -1.55%  (p=0.008 n=5+5)
FmtFprintfFloat-8           492ns ± 0%     494ns ± 1%    ~     (p=0.175 n=4+5)
FmtManyArgs-8              1.32µs ± 1%    1.31µs ± 2%    ~     (p=0.651 n=5+5)
GobDecode-8                16.8ms ± 2%    16.9ms ± 1%    ~     (p=0.310 n=5+5)
GobEncode-8                14.1ms ± 1%    14.1ms ± 1%    ~     (p=1.000 n=5+5)
Gzip-8                      788ms ± 0%     789ms ± 0%    ~     (p=0.548 n=5+5)
Gunzip-8                   83.6ms ± 0%    83.6ms ± 0%    ~     (p=0.548 n=5+5)
HTTPClientServer-8          120µs ± 0%     120µs ± 1%    ~     (p=0.690 n=5+5)
JSONEncode-8               33.2ms ± 0%    33.6ms ± 0%  +1.20%  (p=0.008 n=5+5)
JSONDecode-8                152ms ± 1%     146ms ± 1%  -3.70%  (p=0.008 n=5+5)
Mandelbrot200-8            10.0ms ± 0%    10.0ms ± 0%    ~     (p=0.151 n=5+5)
GoParse-8                  7.97ms ± 0%    8.06ms ± 0%  +1.15%  (p=0.008 n=5+5)
RegexpMatchEasy0_32-8       233ns ± 1%     239ns ± 4%    ~     (p=0.135 n=5+5)
RegexpMatchEasy0_1K-8      1.86µs ± 0%    1.86µs ± 0%    ~     (p=0.167 n=5+5)
RegexpMatchEasy1_32-8       250ns ± 0%     263ns ± 1%  +5.28%  (p=0.008 n=5+5)
RegexpMatchEasy1_1K-8      2.28µs ± 0%    2.13µs ± 0%  -6.64%  (p=0.000 n=4+5)
RegexpMatchMedium_32-8      332ns ± 1%     319ns ± 0%  -3.97%  (p=0.008 n=5+5)
RegexpMatchMedium_1K-8     85.5µs ± 2%    79.1µs ± 1%  -7.42%  (p=0.008 n=5+5)
RegexpMatchHard_32-8       4.34µs ± 1%    4.42µs ± 7%    ~     (p=0.881 n=5+5)
RegexpMatchHard_1K-8        130µs ± 1%     127µs ± 0%  -2.18%  (p=0.008 n=5+5)
Revcomp-8                   1.35s ± 1%     1.34s ± 0%  -0.58%  (p=0.016 n=5+4)
Template-8                  160ms ± 2%     158ms ± 1%    ~     (p=0.222 n=5+5)
TimeParse-8                 795ns ± 2%     772ns ± 2%  -2.87%  (p=0.024 n=5+5)
TimeFormat-8                782ns ± 0%     784ns ± 0%    ~     (p=0.198 n=5+5)

name                     old speed      new speed      delta
GobDecode-8              45.8MB/s ± 2%  45.5MB/s ± 1%    ~     (p=0.310 n=5+5)
GobEncode-8              54.3MB/s ± 1%  54.4MB/s ± 1%    ~     (p=0.984 n=5+5)
Gzip-8                   24.6MB/s ± 0%  24.6MB/s ± 0%    ~     (p=0.540 n=5+5)
Gunzip-8                  232MB/s ± 0%   232MB/s ± 0%    ~     (p=0.548 n=5+5)
JSONEncode-8             58.4MB/s ± 0%  57.7MB/s ± 0%  -1.19%  (p=0.008 n=5+5)
JSONDecode-8             12.8MB/s ± 1%  13.3MB/s ± 1%  +3.85%  (p=0.008 n=5+5)
GoParse-8                7.27MB/s ± 0%  7.18MB/s ± 0%  -1.13%  (p=0.008 n=5+5)
RegexpMatchEasy0_32-8     137MB/s ± 1%   134MB/s ± 4%    ~     (p=0.151 n=5+5)
RegexpMatchEasy0_1K-8     551MB/s ± 0%   550MB/s ± 0%    ~     (p=0.222 n=5+5)
RegexpMatchEasy1_32-8     128MB/s ± 0%   121MB/s ± 1%  -5.09%  (p=0.008 n=5+5)
RegexpMatchEasy1_1K-8     449MB/s ± 0%   481MB/s ± 0%  +7.12%  (p=0.016 n=4+5)
RegexpMatchMedium_32-8   3.00MB/s ± 0%  3.13MB/s ± 0%  +4.33%  (p=0.016 n=4+5)
RegexpMatchMedium_1K-8   12.0MB/s ± 2%  12.9MB/s ± 1%  +7.98%  (p=0.008 n=5+5)
RegexpMatchHard_32-8     7.38MB/s ± 1%  7.25MB/s ± 7%    ~     (p=0.952 n=5+5)
RegexpMatchHard_1K-8     7.88MB/s ± 1%  8.05MB/s ± 0%  +2.21%  (p=0.008 n=5+5)
Revcomp-8                 188MB/s ± 1%   189MB/s ± 0%  +0.58%  (p=0.016 n=5+4)
Template-8               12.2MB/s ± 2%  12.3MB/s ± 1%    ~     (p=0.183 n=5+5)

Change-Id: I65e79f3f8f8b2914678311c4f1b0a2d98459e220
Reviewed-on: https://go-review.googlesource.com/71110Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>

The BigEndian constant is only used in boolean context so assign it
boolean constants.

Change-Id: If19d61dd71cdfbffede1d98b401f11e6535fba59
Reviewed-on: https://go-review.googlesource.com/73270
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I6b16cfcbe824f999c9b64df539deea567e327db7
Reviewed-on: https://go-review.googlesource.com/73090Reviewed-by: Gabriel Aszalos <gabriel.aszalos@gmail.com>
Reviewed-by: Jason Wangsadinata <jwangsadinata@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Gabriel Aszalos <gabriel.aszalos@gmail.com>

Change-Id: I868f5101dd44f427d6504a8dbb198c06107be00e
Reviewed-on: https://go-review.googlesource.com/72380
Run-TryBot: Gabriel Aszalos <gabriel.aszalos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

The new pagezero_size introduced by CL 72730 breaks
on 32-bit systems, since it is 2³². Restrict the change to
darwin/arm64, since it is intended for iOS only.

We could plausibly allow GOARCH=amd64 as well, but
without a compelling reason, changing the zero page size
doesn't seem worth the risk.

Change-Id: I5d6adcbaff8d0e5b169ff13512f188332cc7ed9a
Reviewed-on: https://go-review.googlesource.com/73250
Run-TryBot: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

The record delimiter (not configurable by user) is "\r\n" or "\n".
It is insensible for the user to set Comma or Comment delimiters
to be some character that conflicts with the record delimiter.
Furthermore, it is insensible for Comma or Comment to be the same rune.
Allowing this leaks implementation details to the user in regards to
the evaluation order of which rune is checked for first.

Fixes #22404

Change-Id: I31e86abc9b3a8fb4584e090477795587740970ae
Reviewed-on: https://go-review.googlesource.com/72793Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL expands the job of "dist bootstrap" to be "finish make.bash".
I need to change that logic in upcoming CLs related to cmd/go
changes, and I'd rather not change it in three places in three different
shell script languages.

Change-Id: I545dc215e408289e4d0b28f7c2ffcd849d89ad3b
Reviewed-on: https://go-review.googlesource.com/72870Reviewed-by: David Crawshaw <crawshaw@golang.org>

Change-Id: Id51a2d63f7199b3ff71cedd415345ad20e5bd981
Reviewed-on: https://go-review.googlesource.com/70791Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I54c73afd4fb2ad4d5854d2568524f57542c64fe5
Reviewed-on: https://go-review.googlesource.com/42182
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

There is some stuff I don't understand very well involved in SSUB, better words
for the documentation gratefully accepted.

As this is the last use of a bit in SMASK, kill that off too.

Change-Id: Iddff1c9b2af02c9dfb12ac8e668d004e4642f997
Reviewed-on: https://go-review.googlesource.com/42026
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #15833

Lehmer's GCD algorithm uses single precision calculations
to simulate several steps of multiple precision calculations
in Euclid's GCD algorithm which leads to a considerable
speed up.  This implementation uses Collins' simplified
testing condition on the single digit cosequences which
requires only one quotient and avoids any possibility of
overflow.

name                          old time/op  new time/op  delta
GCD10x10/WithoutXY-4          1.82µs ±24%  0.28µs ± 6%  -84.40%  (p=0.008 n=5+5)
GCD10x10/WithXY-4             1.69µs ± 6%  1.71µs ± 6%     ~     (p=0.595 n=5+5)
GCD10x100/WithoutXY-4         1.87µs ± 2%  0.56µs ± 4%  -70.13%  (p=0.008 n=5+5)
GCD10x100/WithXY-4            2.61µs ± 2%  2.65µs ± 4%     ~     (p=0.635 n=5+5)
GCD10x1000/WithoutXY-4        2.75µs ± 2%  1.48µs ± 1%  -46.06%  (p=0.008 n=5+5)
GCD10x1000/WithXY-4           5.29µs ± 2%  5.25µs ± 2%     ~     (p=0.548 n=5+5)
GCD10x10000/WithoutXY-4       10.7µs ± 2%  10.3µs ± 0%   -4.38%  (p=0.008 n=5+5)
GCD10x10000/WithXY-4          22.3µs ± 6%  22.1µs ± 1%     ~     (p=1.000 n=5+5)
GCD10x100000/WithoutXY-4      93.7µs ± 2%  99.4µs ± 2%   +6.09%  (p=0.008 n=5+5)
GCD10x100000/WithXY-4          196µs ± 2%   199µs ± 2%     ~     (p=0.222 n=5+5)
GCD100x100/WithoutXY-4        10.1µs ± 2%   2.5µs ± 2%  -74.84%  (p=0.008 n=5+5)
GCD100x100/WithXY-4           21.4µs ± 2%  21.3µs ± 7%     ~     (p=0.548 n=5+5)
GCD100x1000/WithoutXY-4       11.3µs ± 2%   4.4µs ± 4%  -60.87%  (p=0.008 n=5+5)
GCD100x1000/WithXY-4          24.7µs ± 3%  23.9µs ± 1%     ~     (p=0.056 n=5+5)
GCD100x10000/WithoutXY-4      26.6µs ± 1%  20.0µs ± 2%  -24.82%  (p=0.008 n=5+5)
GCD100x10000/WithXY-4         78.7µs ± 2%  78.2µs ± 2%     ~     (p=0.690 n=5+5)
GCD100x100000/WithoutXY-4      174µs ± 2%   171µs ± 1%     ~     (p=0.056 n=5+5)
GCD100x100000/WithXY-4         563µs ± 4%   561µs ± 2%     ~     (p=1.000 n=5+5)
GCD1000x1000/WithoutXY-4       120µs ± 5%    29µs ± 3%  -75.71%  (p=0.008 n=5+5)
GCD1000x1000/WithXY-4          355µs ± 4%   358µs ± 2%     ~     (p=0.841 n=5+5)
GCD1000x10000/WithoutXY-4      140µs ± 2%    49µs ± 2%  -65.07%  (p=0.008 n=5+5)
GCD1000x10000/WithXY-4         626µs ± 3%   628µs ± 9%     ~     (p=0.690 n=5+5)
GCD1000x100000/WithoutXY-4     340µs ± 4%   259µs ± 6%  -23.79%  (p=0.008 n=5+5)
GCD1000x100000/WithXY-4       3.76ms ± 4%  3.82ms ± 5%     ~     (p=0.310 n=5+5)
GCD10000x10000/WithoutXY-4    3.11ms ± 3%  0.54ms ± 2%  -82.74%  (p=0.008 n=5+5)
GCD10000x10000/WithXY-4       7.96ms ± 3%  7.69ms ± 3%     ~     (p=0.151 n=5+5)
GCD10000x100000/WithoutXY-4   3.88ms ± 1%  1.27ms ± 2%  -67.21%  (p=0.008 n=5+5)
GCD10000x100000/WithXY-4      38.1ms ± 2%  38.8ms ± 1%     ~     (p=0.095 n=5+5)
GCD100000x100000/WithoutXY-4   208ms ± 1%    25ms ± 4%  -88.07%  (p=0.008 n=5+5)
GCD100000x100000/WithXY-4      533ms ± 5%   525ms ± 4%     ~     (p=0.548 n=5+5)

Change-Id: Ic1e007eb807b93e75f4752e968e98c1f0cb90e43
Reviewed-on: https://go-review.googlesource.com/59450
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Rounding ties to even is statistically useful for some applications.
This implementation completes IEEE float64 rounding mode support (in
addition to Round, Ceil, Floor, Trunc).

This function avoids subtle faults found in ad-hoc implementations, and
is simple enough to be inlined by the compiler.

Fixes #21748

Change-Id: I09415df2e42435f9e7dabe3bdc0148e9b9ebd609
Reviewed-on: https://go-review.googlesource.com/61211Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Eliminates lots of ad hoc code for recognizing the same thing in
different ways.

Passes toolstash-check.

Change-Id: Ic0bb005308e96331b4ef30f455b860e476725b61
Reviewed-on: https://go-review.googlesource.com/73190
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

A single database connection ususally maps to a single session.
A connection pool is logically also a session pool. Most
sessions have a way to reset the session state which is desirable
to prevent one bad query from poisoning another later query with
temp table name conflicts or other persistent session resources.

It also lets drivers provide users with better error messages from
queryies when the underlying transport or query method fails.
Internally the driver connection should now be marked as bad, but
return the actual connection. When ResetSession is called on the
connection it should return driver.ErrBadConn to remove it from
the connection pool. Previously drivers had to choose between
meaningful error messages or poisoning the connection pool.

Lastly update TestPoolExhaustOnCancel from relying on a
WAIT query fixing a flaky timeout issue exposed by this
change.

Fixes #22049
Fixes #20807

Change-Id: I2b5df6d954a38d0ad93bf1922ec16e74c827274c
Reviewed-on: https://go-review.googlesource.com/73033
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #20986.

Change-Id: Ic3cf5c0ab260f259ecff7b92cfdf5f4ae432aef3
Reviewed-on: https://go-review.googlesource.com/73072
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Instead of the hand-written control flow analysis in debug info
generation, use a reverse postorder traversal, which is basically the
same thing. It should be slightly faster.

More importantly, the previous version simply gave up in the case of
non-reducible functions, and produced output that caused a later stage
to crash. It turns out that there's a non-reducible function in
compress/flate, so that wasn't a theoretical issue.

With this change, all blocks will be visited, even for non-reducible
functions.

Change-Id: Id47536764ee93203c6b4105a1a3013fe3265aa12
Reviewed-on: https://go-review.googlesource.com/73110
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Fixes #19183

Change-Id: I11502d855f5b521b03ed7a63a990cca2d0ed4083
Reviewed-on: https://go-review.googlesource.com/70931Reviewed-by: Ian Lance Taylor <iant@golang.org>

This reverts commit 2620ac3a.

Reason for revert: broke all the builds.

Change-Id: I26fc09a13f5f80fa708de66c843442ff9d934694
Reviewed-on: https://go-review.googlesource.com/73050Reviewed-by: Russ Cox <rsc@golang.org>