The comment states that cmd/internal/sys.RaceDetectorSupported is a copy,
so make the two identical. No functional difference, since ppce64le is
only supported on linux anyway.

Change-Id: Id3e4d445fb700b9b3bb53bf15ea05b8911b4f95e
Reviewed-on: https://go-review.googlesource.com/134595
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

At the very beginning of timediv, inside a for loop,
we reduce the base value by at most (1<<31)-1, while
incrementing the quotient result by 1<<uint(bit).
However, since the quotient value was 0 to begin with,
we are essentially just doing bitsets.

This change is in the hot path of various concurrency and
scheduling operations that require sleeping, waiting
on mutexes and futexes etc. On the following OSes:
* Dragonfly
* FreeBSD
* Linux
* NetBSD
* OpenBSD
* Plan9
* Windows

and paired with architectures that provide the BTS instruction, this
change shaves off a couple of nanoseconds per invocation of timediv.

Fixes #27529

Change-Id: Ia2fea5022c1109e02d86d1f962a3b0bd70967aa6
Reviewed-on: https://go-review.googlesource.com/134231
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

This adds an asm implementation for the Count function in ppc64x.
The Go code that manipulates a byte at a time is especially
inefficient on ppc64x, so an asm implementation is a significant
improvement.

bytes:
name               old time/op   new time/op    delta
CountSingle/10-8    23.1ns ± 0%    18.6ns ± 0%    -19.48%  (p=1.000 n=1+1)
CountSingle/32-8    60.4ns ± 0%    19.0ns ± 0%    -68.54%  (p=1.000 n=1+1)
CountSingle/4K-8    7.29µs ± 0%    0.45µs ± 0%    -93.80%  (p=1.000 n=1+1)
CountSingle/4M-8    7.49ms ± 0%    0.45ms ± 0%    -93.97%  (p=1.000 n=1+1)
CountSingle/64M-8    127ms ± 0%       9ms ± 0%    -92.53%  (p=1.000 n=1+1)

html:
name              old time/op  new time/op  delta
Escape-8          57.5µs ± 0%  36.1µs ± 0%  -37.13%  (p=1.000 n=1+1)
EscapeNone-8      20.0µs ± 0%   2.0µs ± 0%  -90.14%  (p=1.000 n=1+1)

Change-Id: Iadbf422c0e9a37b47d2d95fb8c778420f3aabb58
Reviewed-on: https://go-review.googlesource.com/131695
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>

The current assembler accepts the non-integer register as the base register,
which should be an illegal combination.

Add the test cases.

Change-Id: Ia21596bbb5b1e212e34bd3a170748ae788860422
Reviewed-on: https://go-review.googlesource.com/134575Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The CL 132915 added the wrong codegen test for math.Copysign(c, -1),
it should test that AND is not emitted. This CL fixes this error.

Change-Id: Ida1d3d54ebfc7f238abccbc1f70f914e1b5bfd91
Reviewed-on: https://go-review.googlesource.com/134815Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Having these panic-like errors used to be ok, since they were used in
the internal decoder state instead of passed around via return
parameters.

Recently, the decoder was rewritten to use explicit error returns
instead. This error is a terrible fit for error returns; a handful of
functions must return an error because of it, and their callers must
check for an error that should never happen.

This is precisely what panics are for, so use them. The test coverage of
the package goes up from 91.3% to 91.6%, and performance is unaffected.
We can also get rid of some unnecessary verbosity in the code.

name           old time/op    new time/op    delta
CodeDecoder-4    27.5ms ± 1%    27.5ms ± 1%   ~     (p=0.937 n=6+6)

Change-Id: I01033b3f5b7c0cf0985082fa272754f96bf6353c
Reviewed-on: https://go-review.googlesource.com/134835
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

The overall coverage of the json package goes up from 90.8% to 91.3%.

While at it, apply two minor code simplifications found while inspecting
the HTML coverage report.

Change-Id: I0fba968afeedc813b1385e4bde72d93b878854d7
Reviewed-on: https://go-review.googlesource.com/134735
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Some linker flags can actually be input files, which can cause
misleading errors when doing the trial link, which can cause the
linker to incorrectly decide that the flag is not supported, which can
cause the link to fail.

Fixes #27510
Updates #27110
Updates #27293

Change-Id: I70c1e913cee3c813e7b267bf779bcff26d4d194a
Reviewed-on: https://go-review.googlesource.com/134057
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Damien Neil <dneil@google.com>

Change-Id: I2a55cda76f1074b997349dfd6e001dc7277faade
Reviewed-on: https://go-review.googlesource.com/134655Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

Port math/big pure go versions of add-with-carry, subtract-with-borrow,
full-width multiply, and full-width divide.

Updates #24813

Change-Id: Ifae5d2f6ee4237137c9dcba931f69c91b80a4b1c
Reviewed-on: https://go-review.googlesource.com/123157Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

n.Pos.IsKnown() is not needed because it is performed in setlineno.

toolstash-check passed.

Updates #19683.

Change-Id: I34d6a0e6dc9970679d99e8f3424f289ebf1e86ba
Reviewed-on: https://go-review.googlesource.com/114915
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Use the binary.{Big,Little}Endian integer encoding methods rather than
variations found in local implementations. The functions in
the binary package have been tested to ensure they inline correctly and
don't add unnecessary bounds checking.

Change-Id: Ie10111ca6edb7c11e8e5e21c58a5748ae99b7f87
Reviewed-on: https://go-review.googlesource.com/134375
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>

BFC (Bit Field Clear) was introduced in ARMv7, which can simplify
ANDconst and BICconst. And this CL implements that optimization.

1. The total size of pkg/android_arm decreases about 3KB, excluding
cmd/compile/.

2. There is no regression in the go1 benchmark result, and some
cases (FmtFprintfEmpty-4 and RegexpMatchMedium_32-4) even get
slight improvement.

name                     old time/op    new time/op    delta
BinaryTree17-4              25.3s ± 1%     25.2s ± 1%    ~     (p=0.072 n=30+29)
Fannkuch11-4                13.3s ± 0%     13.3s ± 0%  +0.13%  (p=0.000 n=30+26)
FmtFprintfEmpty-4           407ns ± 0%     394ns ± 0%  -3.19%  (p=0.000 n=26+28)
FmtFprintfString-4          664ns ± 0%     662ns ± 0%  -0.22%  (p=0.000 n=30+30)
FmtFprintfInt-4             712ns ± 0%     706ns ± 0%  -0.79%  (p=0.000 n=30+30)
FmtFprintfIntInt-4         1.06µs ± 0%    1.05µs ± 0%  -0.38%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4    1.16µs ± 0%    1.16µs ± 0%  -0.13%  (p=0.000 n=30+29)
FmtFprintfFloat-4          2.24µs ± 0%    2.23µs ± 0%  -0.51%  (p=0.000 n=29+21)
FmtManyArgs-4              4.09µs ± 0%    4.06µs ± 0%  -0.83%  (p=0.000 n=28+30)
GobDecode-4                55.0ms ± 5%    55.4ms ± 5%    ~     (p=0.307 n=30+30)
GobEncode-4                51.2ms ± 1%    51.9ms ± 1%  +1.23%  (p=0.000 n=29+30)
Gzip-4                      2.64s ± 0%     2.60s ± 0%  -1.35%  (p=0.000 n=30+29)
Gunzip-4                    309ms ± 0%     308ms ± 0%  -0.27%  (p=0.000 n=30+30)
HTTPClientServer-4         1.03ms ± 5%    1.02ms ± 4%    ~     (p=0.117 n=30+29)
JSONEncode-4                101ms ± 2%     101ms ± 2%    ~     (p=0.338 n=29+29)
JSONDecode-4                383ms ± 2%     382ms ± 2%    ~     (p=0.751 n=26+30)
Mandelbrot200-4            18.4ms ± 0%    18.4ms ± 0%  -0.10%  (p=0.000 n=29+29)
GoParse-4                  22.6ms ± 0%    22.5ms ± 0%  -0.39%  (p=0.000 n=30+30)
RegexpMatchEasy0_32-4       761ns ± 0%     750ns ± 0%  -1.47%  (p=0.000 n=26+29)
RegexpMatchEasy0_1K-4      4.33µs ± 0%    4.34µs ± 0%  +0.27%  (p=0.000 n=25+28)
RegexpMatchEasy1_32-4       809ns ± 0%     795ns ± 0%  -1.74%  (p=0.000 n=27+25)
RegexpMatchEasy1_1K-4      5.54µs ± 0%    5.53µs ± 0%  -0.18%  (p=0.000 n=29+29)
RegexpMatchMedium_32-4     1.11µs ± 0%    1.08µs ± 0%  -2.78%  (p=0.000 n=27+29)
RegexpMatchMedium_1K-4      255µs ± 0%     255µs ± 0%  -0.02%  (p=0.029 n=30+30)
RegexpMatchHard_32-4       14.7µs ± 0%    14.7µs ± 0%  -0.28%  (p=0.000 n=30+29)
RegexpMatchHard_1K-4        439µs ± 0%     439µs ± 0%    ~     (p=0.907 n=23+27)
Revcomp-4                  41.9ms ± 1%    41.9ms ± 1%    ~     (p=0.230 n=28+30)
Template-4                  522ms ± 1%     528ms ± 1%  +1.25%  (p=0.000 n=30+30)
TimeParse-4                3.34µs ± 0%    3.35µs ± 0%  +0.23%  (p=0.000 n=30+27)
TimeFormat-4               6.06µs ± 0%    6.13µs ± 0%  +1.08%  (p=0.000 n=29+29)
[Geo mean]                  384µs          382µs       -0.37%

name                     old speed      new speed      delta
GobDecode-4              14.0MB/s ± 5%  13.9MB/s ± 5%    ~     (p=0.308 n=30+30)
GobEncode-4              15.0MB/s ± 1%  14.8MB/s ± 1%  -1.22%  (p=0.000 n=29+30)
Gzip-4                   7.36MB/s ± 0%  7.46MB/s ± 0%  +1.35%  (p=0.000 n=30+30)
Gunzip-4                 62.8MB/s ± 0%  63.0MB/s ± 0%  +0.27%  (p=0.000 n=30+30)
JSONEncode-4             19.2MB/s ± 2%  19.2MB/s ± 2%    ~     (p=0.312 n=29+29)
JSONDecode-4             5.05MB/s ± 3%  5.08MB/s ± 2%    ~     (p=0.356 n=29+30)
GoParse-4                2.56MB/s ± 0%  2.57MB/s ± 0%  +0.39%  (p=0.000 n=23+27)
RegexpMatchEasy0_32-4    42.0MB/s ± 0%  42.6MB/s ± 0%  +1.50%  (p=0.000 n=26+28)
RegexpMatchEasy0_1K-4     236MB/s ± 0%   236MB/s ± 0%  -0.27%  (p=0.000 n=25+28)
RegexpMatchEasy1_32-4    39.6MB/s ± 0%  40.2MB/s ± 0%  +1.73%  (p=0.000 n=27+27)
RegexpMatchEasy1_1K-4     185MB/s ± 0%   185MB/s ± 0%  +0.18%  (p=0.000 n=29+29)
RegexpMatchMedium_32-4    900kB/s ± 0%   920kB/s ± 0%  +2.22%  (p=0.000 n=29+29)
RegexpMatchMedium_1K-4   4.02MB/s ± 0%  4.02MB/s ± 0%  +0.07%  (p=0.004 n=30+27)
RegexpMatchHard_32-4     2.17MB/s ± 0%  2.18MB/s ± 0%  +0.46%  (p=0.000 n=30+26)
RegexpMatchHard_1K-4     2.33MB/s ± 0%  2.33MB/s ± 0%    ~     (all equal)
Revcomp-4                60.6MB/s ± 1%  60.7MB/s ± 1%    ~     (p=0.207 n=28+30)
Template-4               3.72MB/s ± 1%  3.67MB/s ± 1%  -1.23%  (p=0.000 n=30+30)
[Geo mean]               12.9MB/s       12.9MB/s       +0.29%

Change-Id: I07f497f8bb476c950dc555491d00c9066fb64a4e
Reviewed-on: https://go-review.googlesource.com/134232
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Use a 64 byte array to avoid an allocation on the assumption that
most url escaping is performed on short strings. Also adds a fast
path for escaping strings whose only replacements are spaces which
is common in query components.

Adds benchmarks for QueryEscape, PathEscape, QueryUnescape and
PathUnescape but no optimizations are include for the unescape functions
so I don't include those benchmark results here.

Reduces allocations by 10% in the existing String benchmark with a
modest performance increase.

name               old time/op    new time/op    delta
QueryEscape/#00-8    64.6ns ± 1%    43.8ns ± 0%  -32.14%  (p=0.000 n=9+9)
QueryEscape/#01-8     276ns ± 3%     249ns ± 0%   -9.62%  (p=0.000 n=10+7)
QueryEscape/#02-8     176ns ± 2%     155ns ± 3%  -12.21%  (p=0.000 n=10+10)
QueryEscape/#03-8     388ns ± 1%     362ns ± 0%   -6.55%  (p=0.000 n=10+8)
QueryEscape/#04-8    2.32µs ± 2%    2.27µs ± 2%   -2.26%  (p=0.001 n=10+10)
PathEscape/#00-8     78.0ns ± 3%    63.4ns ± 1%  -18.69%  (p=0.000 n=10+10)
PathEscape/#01-8      276ns ± 2%     260ns ± 0%   -6.01%  (p=0.000 n=10+10)
PathEscape/#02-8      175ns ± 0%     153ns ± 0%  -12.53%  (p=0.000 n=8+10)
PathEscape/#03-8      389ns ± 2%     361ns ± 0%   -7.21%  (p=0.000 n=10+9)
PathEscape/#04-8     2.30µs ± 2%    2.27µs ± 1%   -1.33%  (p=0.001 n=9+10)
String-8             3.56µs ± 4%    3.42µs ± 7%   -4.00%  (p=0.003 n=10+10)

name               old alloc/op   new alloc/op   delta
QueryEscape/#00-8     16.0B ± 0%      8.0B ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#01-8      128B ± 0%       64B ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#02-8     64.0B ± 0%     32.0B ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#03-8      128B ± 0%       64B ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#04-8      832B ± 0%      832B ± 0%     ~     (all equal)
PathEscape/#00-8      32.0B ± 0%     16.0B ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#01-8       128B ± 0%       64B ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#02-8      64.0B ± 0%     32.0B ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#03-8       128B ± 0%       64B ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#04-8       704B ± 0%      704B ± 0%     ~     (all equal)
String-8             1.84kB ± 0%    1.66kB ± 0%   -9.57%  (p=0.000 n=10+10)

name               old allocs/op  new allocs/op  delta
QueryEscape/#00-8      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#01-8      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#02-8      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#03-8      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
QueryEscape/#04-8      2.00 ± 0%      2.00 ± 0%     ~     (all equal)
PathEscape/#00-8       2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#01-8       2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#02-8       2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#03-8       2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)
PathEscape/#04-8       2.00 ± 0%      2.00 ± 0%     ~     (all equal)
String-8               69.0 ± 0%      61.0 ± 0%  -11.59%  (p=0.000 n=10+10)

Updates #17860

Change-Id: I45c5e9d40b242f874c61f6ccc73bf94c494bb868
Reviewed-on: https://go-review.googlesource.com/134296
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

LineStart returns the position of the start of a given line.
Like MergeLine, it panics if the 1-based line number is invalid.

This function is especially useful in programs that occasionally
handle non-Go files such as assembly but wish to use the token.Pos
mechanism to identify file positions.

Change-Id: I5f774c0690074059553cdb38c0f681f5aafc8da1
Reviewed-on: https://go-review.googlesource.com/134075Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: I855a9c88c379978099ea53c7d28b87cefd7f5d73
Reviewed-on: https://go-review.googlesource.com/134295Reviewed-by: Robert Griesemer <gri@golang.org>

Per golang/go#27524 there are situations where the username for the
uid does not match the value in the $USER environment variable and it
seems sensible to choose the value in /etc/passwd when they disagree.

This may make the Current() call slightly more expensive, since we
read /etc/passwd with cgo disabled instead of just checking the
environment. However, we cache the result of Current() calls, so we
only invoke this cost once in the lifetime of the process.

Fixes #14626.
Fixes #27524.
Updates #24884.

Change-Id: I0dcd224cf7f61dd5292f3fcc363aa2e9656a2cb1
Reviewed-on: https://go-review.googlesource.com/134218Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Zero-byte write was fixed by CL 132781, that was submitted 3 days ago.
But I just submitted CL 129137, and the CL broken zero-byte write
functionality without me noticing. CL 129137 was based on old commit
(older than 3 days ago), and try-bots did not discover the breakage.

Fix zero-byte write again.

Fixes windows build.

Change-Id: Ib403b25fd25cb881963f25706eecca92b924aaa1
Reviewed-on: https://go-review.googlesource.com/134275
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Fixes #26923

Change-Id: I62fec814220ccdf7acd8d79a133d1add3f24cf98
Reviewed-on: https://go-review.googlesource.com/129137Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Merge two case-statements together, since they have similar logic.

1. That makes the assembly generator more clear.
2. The total size of cmd/compile decreases about 0.8KB.

Change-Id: I0144a07152202ee7b21e323bcd5dea80a351a6e3
Reviewed-on: https://go-review.googlesource.com/134215
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

The discussion list was buried beneath the developer mailing list.
This change puts the discussion list first and gives it a more
prominent heading.

Change-Id: I8dcb4af98e454ae3a0140f9758a5656909126983
Reviewed-on: https://go-review.googlesource.com/134136Reviewed-by: Ian Lance Taylor <iant@golang.org>

This simplifies the rewrite rules.

Change-Id: Iff062297d42a23cb31ad55e8c733842ecbc07da2
Reviewed-on: https://go-review.googlesource.com/129377
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

raise uses tkill to send a signal to the current thread. For this use,
tgkill is functionally equivalent to tkill expect that it also takes the
pid as the first argument.

Using tgkill makes it simpler to run a Go program in a strict sandbox.
With kill and tgkill, the sandbox policy (e.g., seccomp) can prevent the
program from sending signals to other processes by checking that the
first argument == getpid().

With tkill, the policy must whitelist all tids in the process, which is
effectively impossible given Go's dynamic thread creation.

Fixes #27548

Change-Id: I8ed282ef1f7215b02ef46de144493e36454029ea
Reviewed-on: https://go-review.googlesource.com/133975
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #27496

Change-Id: I53538c7697729294a9e50ace26a6a7183131e837
Reviewed-on: https://go-review.googlesource.com/134016
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>

Added some more cases that should be guarded against regression.

Change-Id: I9f1dda2fd0be9b6e167ef1cc018fc8cce55c066c
Reviewed-on: https://go-review.googlesource.com/134017
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

At least one popular service puts a hostname which contains a ":"
in the Common Name field. On the other hand, I don't know of any name
constrained certificates that only work if we ignore such CNs.

Updates #24151

Change-Id: I2d813e3e522ebd65ab5ea5cd83390467a869eea3
Reviewed-on: https://go-review.googlesource.com/134076
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When pthread_cond_timedwait_relative_np gets a spurious wakeup
(due to a signal, typically), we used to retry with the same
relative timeout. That's incorrect, we should lower the timeout
by the time we've spent in this function so far.

In the worst case, signals come in and cause spurious wakeups
faster than the timeout, causing semasleep to never time out.

Also fix nacl and netbsd while we're here. They have similar issues.

Fixes #27520

Change-Id: I6601e120e44a4b8ef436eef75a1e7c8cf1d39e39
Reviewed-on: https://go-review.googlesource.com/133655
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Add some rules to match the Go code like:
	y &= 63
	x << y | x >> (64-y)
or
	y &= 63
	x >> y | x << (64-y)
as a ROR instruction. Make math/bits.RotateLeft faster on arm64.

Extends CL 132435 to arm64.

Benchmarks of math/bits.RotateLeftxxN:
name            old time/op       new time/op       delta
RotateLeft-8    3.548750ns +- 1%  2.003750ns +- 0%  -43.54%  (p=0.000 n=8+8)
RotateLeft8-8   3.925000ns +- 0%  3.925000ns +- 0%     ~     (p=1.000 n=8+8)
RotateLeft16-8  3.925000ns +- 0%  3.927500ns +- 0%     ~     (p=0.608 n=8+8)
RotateLeft32-8  3.925000ns +- 0%  2.002500ns +- 0%  -48.98%  (p=0.000 n=8+8)
RotateLeft64-8  3.536250ns +- 0%  2.003750ns +- 0%  -43.34%  (p=0.000 n=8+8)

Change-Id: I77622cd7f39b917427e060647321f5513973232c
Reviewed-on: https://go-review.googlesource.com/122542
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

This is needed in addition to CL 102555 in order to be able to generate
Go type definitions for linux/sparc64 in the golang.org/x/sys/unix
package.

Change-Id: I928185e320572fecb0c89396f871ea16cba8b9a6
Reviewed-on: https://go-review.googlesource.com/132155
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Updates #27376

Change-Id: I9ce6541a95b5ecd13f3932558427de1f597df07a
Reviewed-on: https://go-review.googlesource.com/134036
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Updates #27376

Change-Id: I2fa63b0d1981a419626072d985e6f3326f6013ff
Reviewed-on: https://go-review.googlesource.com/134035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Updates #27376

Change-Id: I0ceb672a9fcd7bbf491be1577d7f135ef35b2561
Reviewed-on: https://go-review.googlesource.com/133455
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This were missed in CL 107339 as it is not documented (yet) in
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md

But binutils already uses it. See
https://github.com/riscv/riscv-elf-psabi-doc/issues/36

Change-Id: I1b084cbf70eb6ac966136bed1bb654883a97b6a9
Reviewed-on: https://go-review.googlesource.com/134015
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

If binary file of a running program was deleted or moved, maps
file (/proc/pid/maps) will contain lines that have this binary
filename suffixed with "(deleted)" string. This suffix stayed
as a part of the filename and made remote profiling slightly more
difficult by requiring from a user to rename binary file to
include this suffix.

This change cleans up the filename and removes this suffix and
thus simplify debugging.

Fixes #25740

Change-Id: Ib3c8c3b9ef536c2ac037fcc14e8037fa5c960036
Reviewed-on: https://go-review.googlesource.com/116395
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

Optimization of "(CMPconst [0] (ANDL x y)) -> (TESTL x y)" only
get benefits if there is no further use of the result of x&y. A
condition of uses==1 will have slight improvements.

1. The code size of pkg/linux_386 decreases about 300 bytes, excluding
cmd/compile/.

2. The go1 benchmark shows no regression, and even a slight improvement
in test case FmtFprintfEmpty-4, excluding noise.

name                     old time/op    new time/op    delta
BinaryTree17-4              3.34s ± 3%     3.32s ± 2%    ~     (p=0.197 n=30+30)
Fannkuch11-4                3.48s ± 2%     3.47s ± 1%  -0.33%  (p=0.015 n=30+30)
FmtFprintfEmpty-4          46.3ns ± 4%    44.8ns ± 4%  -3.33%  (p=0.000 n=30+30)
FmtFprintfString-4         78.8ns ± 7%    77.3ns ± 5%    ~     (p=0.098 n=30+26)
FmtFprintfInt-4            90.2ns ± 1%    90.0ns ± 7%  -0.23%  (p=0.027 n=18+30)
FmtFprintfIntInt-4          144ns ± 4%     143ns ± 5%    ~     (p=0.945 n=30+29)
FmtFprintfPrefixedInt-4     180ns ± 4%     180ns ± 5%    ~     (p=0.858 n=30+30)
FmtFprintfFloat-4           409ns ± 4%     406ns ± 3%  -0.87%  (p=0.028 n=30+30)
FmtManyArgs-4               611ns ± 5%     608ns ± 4%    ~     (p=0.812 n=30+30)
GobDecode-4                7.30ms ± 5%    7.26ms ± 5%    ~     (p=0.522 n=30+29)
GobEncode-4                6.90ms ± 7%    6.82ms ± 4%    ~     (p=0.086 n=29+28)
Gzip-4                      396ms ± 4%     400ms ± 4%  +0.99%  (p=0.026 n=30+30)
Gunzip-4                   41.1ms ± 3%    41.2ms ± 3%    ~     (p=0.495 n=30+30)
HTTPClientServer-4         63.7µs ± 3%    63.3µs ± 2%    ~     (p=0.113 n=29+29)
JSONEncode-4               16.1ms ± 2%    16.1ms ± 2%  -0.30%  (p=0.041 n=30+30)
JSONDecode-4               60.9ms ± 3%    61.2ms ± 6%    ~     (p=0.187 n=30+30)
Mandelbrot200-4            5.17ms ± 2%    5.19ms ± 3%    ~     (p=0.676 n=30+30)
GoParse-4                  3.28ms ± 3%    3.25ms ± 2%  -0.97%  (p=0.002 n=30+30)
RegexpMatchEasy0_32-4       103ns ± 4%     104ns ± 4%    ~     (p=0.352 n=30+30)
RegexpMatchEasy0_1K-4       849ns ± 2%     845ns ± 2%    ~     (p=0.381 n=30+30)
RegexpMatchEasy1_32-4       113ns ± 4%     113ns ± 4%    ~     (p=0.795 n=30+30)
RegexpMatchEasy1_1K-4      1.03µs ± 3%    1.03µs ± 4%    ~     (p=0.275 n=25+30)
RegexpMatchMedium_32-4      132ns ± 3%     132ns ± 3%    ~     (p=0.970 n=30+30)
RegexpMatchMedium_1K-4     41.4µs ± 3%    41.4µs ± 3%    ~     (p=0.212 n=30+30)
RegexpMatchHard_32-4       2.22µs ± 4%    2.22µs ± 4%    ~     (p=0.399 n=30+30)
RegexpMatchHard_1K-4       67.2µs ± 3%    67.6µs ± 4%    ~     (p=0.359 n=30+30)
Revcomp-4                   1.84s ± 2%     1.83s ± 2%    ~     (p=0.532 n=30+30)
Template-4                 69.1ms ± 4%    68.8ms ± 3%    ~     (p=0.146 n=30+30)
TimeParse-4                 441ns ± 3%     442ns ± 3%    ~     (p=0.154 n=30+30)
TimeFormat-4                413ns ± 3%     414ns ± 3%    ~     (p=0.275 n=30+30)
[Geo mean]                 66.2µs         66.0µs       -0.28%

name                     old speed      new speed      delta
GobDecode-4               105MB/s ± 5%   106MB/s ± 5%    ~     (p=0.514 n=30+29)
GobEncode-4               111MB/s ± 5%   113MB/s ± 4%  +1.37%  (p=0.046 n=28+28)
Gzip-4                   49.1MB/s ± 4%  48.6MB/s ± 4%  -0.98%  (p=0.028 n=30+30)
Gunzip-4                  472MB/s ± 4%   472MB/s ± 3%    ~     (p=0.496 n=30+30)
JSONEncode-4              120MB/s ± 2%   121MB/s ± 2%  +0.29%  (p=0.042 n=30+30)
JSONDecode-4             31.9MB/s ± 3%  31.7MB/s ± 6%    ~     (p=0.186 n=30+30)
GoParse-4                17.6MB/s ± 3%  17.8MB/s ± 2%  +0.98%  (p=0.002 n=30+30)
RegexpMatchEasy0_32-4     309MB/s ± 4%   307MB/s ± 4%    ~     (p=0.501 n=30+30)
RegexpMatchEasy0_1K-4    1.21GB/s ± 2%  1.21GB/s ± 2%    ~     (p=0.301 n=30+30)
RegexpMatchEasy1_32-4     283MB/s ± 4%   282MB/s ± 3%    ~     (p=0.877 n=30+30)
RegexpMatchEasy1_1K-4    1.00GB/s ± 3%  0.99GB/s ± 4%    ~     (p=0.276 n=25+30)
RegexpMatchMedium_32-4   7.54MB/s ± 3%  7.55MB/s ± 3%    ~     (p=0.528 n=30+30)
RegexpMatchMedium_1K-4   24.7MB/s ± 3%  24.7MB/s ± 3%    ~     (p=0.203 n=30+30)
RegexpMatchHard_32-4     14.4MB/s ± 4%  14.4MB/s ± 4%    ~     (p=0.407 n=30+30)
RegexpMatchHard_1K-4     15.3MB/s ± 3%  15.1MB/s ± 4%    ~     (p=0.306 n=30+30)
Revcomp-4                 138MB/s ± 2%   139MB/s ± 2%    ~     (p=0.520 n=30+30)
Template-4               28.1MB/s ± 4%  28.2MB/s ± 3%    ~     (p=0.149 n=30+30)
[Geo mean]               81.5MB/s       81.5MB/s       +0.06%

Change-Id: I7f75425f79eec93cdd8fdd94db13ad4f61b6a2f5
Reviewed-on: https://go-review.googlesource.com/133657
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Add rewrite rules to optimize math.Copysign() when the second
argument is negative floating point constant.

For example, math.Copysign(c, -2): The previous compile output is
"AND $9223372036854775807, R0, R0; ORR $-9223372036854775808, R0, R0".
The optimized compile output is "ORR $-9223372036854775808, R0, R0"

Math package benchmark results.
name                   old time/op  new time/op  delta
Copysign-8             2.61ns ± 2%  2.49ns ± 0%  -4.55%  (p=0.000 n=10+10)
Cos-8                  43.0ns ± 0%  41.5ns ± 0%  -3.49%  (p=0.000 n=10+10)
Cosh-8                 98.6ns ± 0%  98.1ns ± 0%  -0.51%  (p=0.000 n=10+10)
ExpGo-8                 107ns ± 0%   105ns ± 0%  -1.87%  (p=0.000 n=10+10)
Exp2Go-8                100ns ± 0%   100ns ± 0%  +0.39%  (p=0.000 n=10+8)
Max-8                  6.56ns ± 2%  6.45ns ± 1%  -1.63%  (p=0.002 n=10+10)
Min-8                  6.66ns ± 3%  6.47ns ± 2%  -2.82%  (p=0.006 n=10+10)
Mod-8                   107ns ± 1%   104ns ± 1%  -2.72%  (p=0.000 n=10+10)
Frexp-8                11.5ns ± 1%  11.0ns ± 0%  -4.56%  (p=0.000 n=8+10)
HypotGo-8              19.4ns ± 0%  19.4ns ± 0%  +0.36%  (p=0.019 n=10+10)
Ilogb-8                8.63ns ± 0%  8.51ns ± 0%  -1.36%  (p=0.000 n=10+10)
Jn-8                    584ns ± 0%   585ns ± 0%  +0.17%  (p=0.000 n=7+8)
Ldexp-8                13.8ns ± 0%  13.5ns ± 0%  -2.17%  (p=0.002 n=8+10)
Logb-8                 10.2ns ± 0%   9.9ns ± 0%  -2.65%  (p=0.000 n=10+7)
Nextafter64-8          7.54ns ± 0%  7.51ns ± 0%  -0.37%  (p=0.000 n=10+10)
Remainder-8            73.5ns ± 1%  70.4ns ± 1%  -4.27%  (p=0.000 n=10+10)
SqrtGoLatency-8        79.6ns ± 0%  76.2ns ± 0%  -4.30%  (p=0.000 n=9+10)
Yn-8                    582ns ± 0%   579ns ± 0%  -0.52%  (p=0.000 n=10+10)

Change-Id: I0c9cd1ea87435e7b8bab94b4e79e6e29785f25b1
Reviewed-on: https://go-review.googlesource.com/132915Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

According to ARM64 manual, it is "constrained unpredictable behavior"
if the src and dst registers of some load/store instructions are same.
In order to completely prevent such unpredictable behavior, adding the
check for load/store instructions that are supported by the assembler
in the assembler.

Add test cases.

Update #25823

Change-Id: I64c14ad99ee543d778e7ec8ae6516a532293dbb3
Reviewed-on: https://go-review.googlesource.com/120660
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Rationale: small buffer optimization does not work and it has
made things slower since 2014. Until we can make it work,
we should prefer simpler code that also turns out to be more
efficient.

With this change, it's possible to use
NewBuffer(make([]byte, 0, bootstrapSize)) to get the desired
stack-allocated initial buffer since escape analysis can
prove the created slice to be non-escaping.

New implementation key points:

    - Zero value bytes.Buffer performs better than before
    - You can have a truly stack-allocated buffer, and it's not even limited to 64 bytes
    - The unsafe.Sizeof(bytes.Buffer{}) is reduced significantly
    - Empty writes don't cause allocations

Buffer benchmarks from bytes package:

    name                       old time/op    new time/op    delta
    ReadString-8                 9.20µs ± 1%    9.22µs ± 1%     ~     (p=0.148 n=10+10)
    WriteByte-8                  28.1µs ± 0%    26.2µs ± 0%   -6.78%  (p=0.000 n=10+10)
    WriteRune-8                  64.9µs ± 0%    65.0µs ± 0%   +0.16%  (p=0.000 n=10+10)
    BufferNotEmptyWriteRead-8     469µs ± 0%     461µs ± 0%   -1.76%  (p=0.000 n=9+10)
    BufferFullSmallReads-8        108µs ± 0%     108µs ± 0%   -0.21%  (p=0.000 n=10+10)

    name                       old speed      new speed      delta
    ReadString-8               3.56GB/s ± 1%  3.55GB/s ± 1%     ~     (p=0.165 n=10+10)
    WriteByte-8                 146MB/s ± 0%   156MB/s ± 0%   +7.26%  (p=0.000 n=9+10)
    WriteRune-8                 189MB/s ± 0%   189MB/s ± 0%   -0.16%  (p=0.000 n=10+10)

    name                       old alloc/op   new alloc/op   delta
    ReadString-8                 32.8kB ± 0%    32.8kB ± 0%     ~     (all equal)
    WriteByte-8                   0.00B          0.00B          ~     (all equal)
    WriteRune-8                   0.00B          0.00B          ~     (all equal)
    BufferNotEmptyWriteRead-8    4.72kB ± 0%    4.67kB ± 0%   -1.02%  (p=0.000 n=10+10)
    BufferFullSmallReads-8       3.44kB ± 0%    3.33kB ± 0%   -3.26%  (p=0.000 n=10+10)

    name                       old allocs/op  new allocs/op  delta
    ReadString-8                   1.00 ± 0%      1.00 ± 0%     ~     (all equal)
    WriteByte-8                    0.00           0.00          ~     (all equal)
    WriteRune-8                    0.00           0.00          ~     (all equal)
    BufferNotEmptyWriteRead-8      3.00 ± 0%      3.00 ± 0%     ~     (all equal)
    BufferFullSmallReads-8         3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=10+10)

The most notable thing in go1 benchmarks is reduced allocs in HTTPClientServer (-1 alloc):

    HTTPClientServer-8           64.0 ± 0%      63.0 ± 0%  -1.56%  (p=0.000 n=10+10)

For more explanations and benchmarks see the referenced issue.

Updates #7921

Change-Id: Ica0bf85e1b70fb4f5dc4f6a61045e2cf4ef72aa3
Reviewed-on: https://go-review.googlesource.com/133715Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This builds on:
https://github.com/golang/go/pull/27445

"...And then send change to fix windows internal/poll.FD.WriteTo - together with making TestUDPZeroBytePayload run again."
- alexbrainman - https://github.com/golang/go/issues/26668#issuecomment-408657503

Fixes #26668

Change-Id: Icd9ecb07458f13e580b3e7163a5946ccec342509
GitHub-Last-Rev: 3bf2b8b46bb8cf79903930631433a1f2ce50ec42
GitHub-Pull-Request: golang/go#27446
Reviewed-on: https://go-review.googlesource.com/132781
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Fixes: #27464

Change-Id: I270c56fd0d5ae8787a1293029aff3072f4f52f33
Reviewed-on: https://go-review.googlesource.com/132955Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>