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>

Change-Id: Ibc40237981fdd20316f73f7f6f3dfa918dd0af5d
Reviewed-on: https://go-review.googlesource.com/133658Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates golang/go#27376.

Change-Id: Ia8608561eb6a268aa7eae8c39c7098df100b643a
Reviewed-on: https://go-review.googlesource.com/133075Reviewed-by: Kevin Burke <kev@inburke.com>
Run-TryBot: Kevin Burke <kev@inburke.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The existing implementation causes a compiler panic if a function parameter shadows a built-in function, and then calling that shadowed name.

Fixes #27356
Change-Id: I1ffb6dc01e63c7f499e5f6f75f77ce2318f35bcd
Reviewed-on: https://go-review.googlesource.com/132876Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

First, move the strings.Count logic out of emit, since only itemText
requires that. Use it in those call sites. itemLeftDelim and
itemRightDelim cannot contain newlines, as they're the "{{" and "}}"
tokens.

Secondly, introduce a startLine lexer field so that we don't have to
keep track of it elsewhere. That's also a requirement to move the
strings.Count out of emit, as emit modifies the start position field.

Change-Id: I69175f403487607a8e5b561b3f1916ee9dc3c0c6
Reviewed-on: https://go-review.googlesource.com/132275
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

The formatting verb '%#x' was used for uint32 values in CL 132956.
This fixes TestFormats.

Change-Id: I3ab6519bde2cb74410fdca14829689cb46bf7022
Reviewed-on: https://go-review.googlesource.com/133595
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

https://go-review.googlesource.com/c/go/+/132355 addressed
a crash and inadvertently fixed #27346; however the comment
added to the type-checker was incorrect and misleading.

This CL fixes the comment, and adds a test case for #27346.

Fixes #27346.
Updates #22467.

Change-Id: Ib6d5caedf302fd42929c4dacc55e973c1aebfe85
Reviewed-on: https://go-review.googlesource.com/133415
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>

Signalling NaNs were being converted to quiet NaNs during constant
propagation through integer <-> float store-to-load forwarding.
This occurs because we store float32 constants as float64
values and CPU hardware 'quietens' NaNs during conversion between
the two.

Eventually we want to move to using float32 values to store float32
constants, however this will be a big change since both the compiler
and the assembler expect float64 values. So for now this is a small
change that will fix the immediate issue.

Fixes #27193.

Change-Id: Iac54bd8c13abe26f9396712bc71f9b396f842724
Reviewed-on: https://go-review.googlesource.com/132956
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Optimize (CMPconst [0] (ADD x y)) to (CMN x y) will only get benefits
when the result of the addition is no longer used, otherwise there
might be even performance drop. And this CL fixes that issue for
CMP/CMN/TST/TEQ.

There is little regression in the go1 benchmark (excluding noise),
and the test case JSONDecode-4 even gets improvement.

name                     old time/op    new time/op    delta
BinaryTree17-4              21.6s ± 1%     21.6s ± 0%  -0.22%  (p=0.013 n=30+30)
Fannkuch11-4                11.1s ± 0%     11.1s ± 0%  +0.11%  (p=0.000 n=30+29)
FmtFprintfEmpty-4           297ns ± 0%     297ns ± 0%  +0.08%  (p=0.007 n=26+28)
FmtFprintfString-4          589ns ± 1%     589ns ± 0%    ~     (p=0.659 n=30+25)
FmtFprintfInt-4             644ns ± 1%     650ns ± 0%  +0.88%  (p=0.000 n=30+24)
FmtFprintfIntInt-4          964ns ± 0%     977ns ± 0%  +1.33%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4    1.06µs ± 0%    1.07µs ± 0%  +1.31%  (p=0.000 n=29+27)
FmtFprintfFloat-4          1.89µs ± 0%    1.92µs ± 0%  +1.25%  (p=0.000 n=29+29)
FmtManyArgs-4              3.63µs ± 0%    3.67µs ± 0%  +1.33%  (p=0.000 n=29+27)
GobDecode-4                38.1ms ± 1%    37.9ms ± 1%  -0.60%  (p=0.000 n=29+29)
GobEncode-4                35.3ms ± 2%    35.2ms ± 1%    ~     (p=0.286 n=30+30)
Gzip-4                      2.36s ± 0%     2.37s ± 2%    ~     (p=0.277 n=24+28)
Gunzip-4                    264ms ± 1%     264ms ± 1%    ~     (p=0.104 n=28+30)
HTTPClientServer-4         1.04ms ± 4%    1.02ms ± 4%  -1.65%  (p=0.000 n=28+28)
JSONEncode-4               78.5ms ± 1%    79.6ms ± 1%  +1.34%  (p=0.000 n=27+28)
JSONDecode-4                379ms ± 4%     352ms ± 5%  -7.09%  (p=0.000 n=29+30)
Mandelbrot200-4            17.6ms ± 0%    17.6ms ± 0%    ~     (p=0.206 n=28+29)
GoParse-4                  21.9ms ± 1%    22.1ms ± 1%  +0.87%  (p=0.000 n=28+26)
RegexpMatchEasy0_32-4       631ns ± 0%     641ns ± 0%  +1.63%  (p=0.000 n=29+30)
RegexpMatchEasy0_1K-4      4.11µs ± 0%    4.11µs ± 0%    ~     (p=0.700 n=30+30)
RegexpMatchEasy1_32-4       670ns ± 0%     679ns ± 0%  +1.37%  (p=0.000 n=21+30)
RegexpMatchEasy1_1K-4      5.31µs ± 0%    5.26µs ± 0%  -1.03%  (p=0.000 n=25+28)
RegexpMatchMedium_32-4      905ns ± 0%     906ns ± 0%  +0.14%  (p=0.001 n=30+30)
RegexpMatchMedium_1K-4      192µs ± 0%     191µs ± 0%  -0.45%  (p=0.000 n=29+27)
RegexpMatchHard_32-4       11.8µs ± 0%    11.7µs ± 0%  -0.39%  (p=0.000 n=29+28)
RegexpMatchHard_1K-4        347µs ± 0%     347µs ± 0%    ~     (p=0.084 n=29+30)
Revcomp-4                  37.5ms ± 1%    37.5ms ± 1%    ~     (p=0.279 n=29+29)
Template-4                  519ms ± 2%     519ms ± 2%    ~     (p=0.652 n=28+29)
TimeParse-4                2.83µs ± 0%    2.78µs ± 0%  -1.90%  (p=0.000 n=27+28)
TimeFormat-4               5.79µs ± 0%    5.60µs ± 0%  -3.23%  (p=0.000 n=29+29)
[Geo mean]                  331µs          330µs       -0.16%

name                     old speed      new speed      delta
GobDecode-4              20.1MB/s ± 1%  20.3MB/s ± 1%  +0.61%  (p=0.000 n=29+29)
GobEncode-4              21.7MB/s ± 2%  21.8MB/s ± 1%    ~     (p=0.294 n=30+30)
Gzip-4                   8.23MB/s ± 1%  8.20MB/s ± 2%    ~     (p=0.099 n=26+28)
Gunzip-4                 73.5MB/s ± 1%  73.4MB/s ± 1%    ~     (p=0.107 n=28+30)
JSONEncode-4             24.7MB/s ± 1%  24.4MB/s ± 1%  -1.32%  (p=0.000 n=27+28)
JSONDecode-4             5.13MB/s ± 4%  5.52MB/s ± 5%  +7.65%  (p=0.000 n=29+30)
GoParse-4                2.65MB/s ± 1%  2.63MB/s ± 1%  -0.87%  (p=0.000 n=28+26)
RegexpMatchEasy0_32-4    50.7MB/s ± 0%  49.9MB/s ± 0%  -1.58%  (p=0.000 n=29+29)
RegexpMatchEasy0_1K-4     249MB/s ± 0%   249MB/s ± 0%    ~     (p=0.342 n=30+28)
RegexpMatchEasy1_32-4    47.7MB/s ± 0%  47.1MB/s ± 0%  -1.39%  (p=0.000 n=26+30)
RegexpMatchEasy1_1K-4     193MB/s ± 0%   195MB/s ± 0%  +1.04%  (p=0.000 n=25+28)
RegexpMatchMedium_32-4   1.10MB/s ± 0%  1.10MB/s ± 0%  -0.42%  (p=0.000 n=30+26)
RegexpMatchMedium_1K-4   5.33MB/s ± 0%  5.36MB/s ± 0%  +0.43%  (p=0.000 n=29+29)
RegexpMatchHard_32-4     2.72MB/s ± 0%  2.73MB/s ± 0%  +0.37%  (p=0.000 n=29+30)
RegexpMatchHard_1K-4     2.95MB/s ± 0%  2.95MB/s ± 0%    ~     (all equal)
Revcomp-4                67.8MB/s ± 1%  67.7MB/s ± 1%    ~     (p=0.273 n=29+29)
Template-4               3.74MB/s ± 2%  3.74MB/s ± 2%    ~     (p=0.665 n=28+29)
[Geo mean]               15.2MB/s       15.2MB/s       +0.21%

Change-Id: Ifed1fb8cc02d5ca52c8bc6c21b6b5bf6dbb2701a
Reviewed-on: https://go-review.googlesource.com/132115
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Current assembler rewrites float constants to values stored in memory
except 0.0, which is not performant. This patch uses the FMOVS/FMOVD
instructions to move some available floating-point immediate constants
into SIMD&FP destination registers. These available constants can be
encoded into FMOVS/FMOVD instructions, checked by the chipfloat7() function.

go1 benchmark results.
name                     old time/op    new time/op    delta
BinaryTree17-8              6.27s ± 1%     6.27s ± 1%    ~     (p=0.762 n=10+8)
Fannkuch11-8                5.42s ± 1%     5.38s ± 0%  -0.63%  (p=0.000 n=10+10)
FmtFprintfEmpty-8          92.9ns ± 1%    93.4ns ± 0%  +0.47%  (p=0.004 n=9+8)
FmtFprintfString-8          169ns ± 2%     170ns ± 4%    ~     (p=0.378 n=10+10)
FmtFprintfInt-8             197ns ± 1%     196ns ± 1%  -0.77%  (p=0.009 n=10+9)
FmtFprintfIntInt-8          284ns ± 1%     286ns ± 1%    ~     (p=0.051 n=10+10)
FmtFprintfPrefixedInt-8     419ns ± 0%     422ns ± 1%  +0.69%  (p=0.038 n=6+10)
FmtFprintfFloat-8           458ns ± 0%     463ns ± 1%  +1.14%  (p=0.000 n=10+10)
FmtManyArgs-8              1.35µs ± 2%    1.36µs ± 1%  +0.91%  (p=0.043 n=10+10)
GobDecode-8                16.0ms ± 2%    15.5ms ± 1%   -3.39%  (p=0.000 n=10+10)
GobEncode-8                11.9ms ± 3%    11.4ms ± 1%   -3.98%  (p=0.000 n=10+9)
Gzip-8                      621ms ± 0%     625ms ± 0%   +0.59%  (p=0.000 n=9+10)
Gunzip-8                   74.0ms ± 1%    74.3ms ± 0%     ~     (p=0.059 n=9+8)
HTTPClientServer-8          116µs ± 1%     116µs ± 1%     ~     (p=0.165 n=10+10)
JSONEncode-8               29.3ms ± 1%    29.5ms ± 0%   +0.72%  (p=0.001 n=10+10)
JSONDecode-8                145ms ± 1%     148ms ± 2%   +2.06%  (p=0.000 n=10+10)
Mandelbrot200-8            9.67ms ± 0%    9.48ms ± 1%   -1.92%  (p=0.000 n=8+10)
GoParse-8                  7.55ms ± 0%    7.60ms ± 0%   +0.57%  (p=0.000 n=9+10)
RegexpMatchEasy0_32-8       234ns ± 0%     210ns ± 0%  -10.13%  (p=0.000 n=8+10)
RegexpMatchEasy0_1K-8       753ns ± 1%     729ns ± 0%   -3.17%  (p=0.000 n=10+8)
RegexpMatchEasy1_32-8       225ns ± 0%     224ns ± 0%   -0.44%  (p=0.000 n=9+9)
RegexpMatchEasy1_1K-8      1.03µs ± 0%    1.04µs ± 1%   +1.29%  (p=0.000 n=10+10)
RegexpMatchMedium_32-8      320ns ± 3%     296ns ± 6%   -7.50%  (p=0.000 n=10+10)
RegexpMatchMedium_1K-8     77.0µs ± 5%    73.6µs ± 1%     ~     (p=0.393 n=10+10)
RegexpMatchHard_32-8       3.93µs ± 0%    3.89µs ± 1%   -0.95%  (p=0.000 n=10+9)
RegexpMatchHard_1K-8        120µs ± 5%     115µs ± 1%     ~     (p=0.739 n=10+10)
Revcomp-8                   1.07s ± 0%     1.08s ± 1%   +0.63%  (p=0.000 n=10+9)
Template-8                  165ms ± 1%     163ms ± 1%   -1.05%  (p=0.001 n=8+10)
TimeParse-8                 751ns ± 1%     749ns ± 1%     ~     (p=0.209 n=10+10)
TimeFormat-8                759ns ± 1%     751ns ± 1%   -0.96%  (p=0.001 n=10+10)

name                     old speed      new speed      delta
GobDecode-8              48.0MB/s ± 2%  49.6MB/s ± 1%   +3.50%  (p=0.000 n=10+10)
GobEncode-8              64.5MB/s ± 3%  67.1MB/s ± 1%   +4.08%  (p=0.000 n=10+9)
Gzip-8                   31.2MB/s ± 0%  31.1MB/s ± 0%   -0.55%  (p=0.000 n=9+8)
Gunzip-8                  262MB/s ± 1%   261MB/s ± 0%     ~     (p=0.059 n=9+8)
JSONEncode-8             66.3MB/s ± 1%  65.8MB/s ± 0%   -0.72%  (p=0.001 n=10+10)
JSONDecode-8             13.4MB/s ± 1%  13.2MB/s ± 1%   -2.02%  (p=0.000 n=10+10)
GoParse-8                7.67MB/s ± 0%  7.63MB/s ± 0%   -0.57%  (p=0.000 n=9+10)
RegexpMatchEasy0_32-8     136MB/s ± 0%   152MB/s ± 0%  +11.45%  (p=0.000 n=10+10)
RegexpMatchEasy0_1K-8    1.36GB/s ± 1%  1.40GB/s ± 0%   +3.25%  (p=0.000 n=10+8)
RegexpMatchEasy1_32-8     142MB/s ± 0%   143MB/s ± 0%   +0.35%  (p=0.000 n=10+9)
RegexpMatchEasy1_1K-8     992MB/s ± 0%   980MB/s ± 1%   -1.27%  (p=0.000 n=10+10)
RegexpMatchMedium_32-8   3.12MB/s ± 3%  3.38MB/s ± 6%   +8.17%  (p=0.000 n=10+10)
RegexpMatchMedium_1K-8   13.3MB/s ± 5%  13.9MB/s ± 1%     ~     (p=0.362 n=10+10)
RegexpMatchHard_32-8     8.14MB/s ± 0%  8.21MB/s ± 1%   +0.95%  (p=0.000 n=10+9)
RegexpMatchHard_1K-8     8.54MB/s ± 5%  8.90MB/s ± 1%     ~     (p=0.636 n=10+10)
Revcomp-8                 238MB/s ± 0%   236MB/s ± 1%   -0.63%  (p=0.000 n=10+9)
Template-8               11.8MB/s ± 1%  11.9MB/s ± 1%   +1.07%  (p=0.001 n=8+10)

Change-Id: I57b372d8dcd47e6aec39893843b20385d5d9c37e
Reviewed-on: https://go-review.googlesource.com/129555
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The ppc64x builders are failing on the new splice test from CL 113997
but the actual failure is being obscured by a test deadlock.

Change-Id: I7747f88bcdba9776a3c0d2f5066cfec572706108
Reviewed-on: https://go-review.googlesource.com/133417
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

The android builders are failing on the AF_UNIX part of the new splice
test from CL 113997. Skip them.

Change-Id: Ia0519aae922acb11d2845aa687633935bcd4b1b0
Reviewed-on: https://go-review.googlesource.com/133515
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

For OINDEX and other Left+Right nodes, we want the whole
node to be considered as "may affect memory" if either
of Left or Right affect memory. Initial implementation
only considered node as such if both Left and Right were non-safe.

Change-Id: Icfb965a0b4c24d8f83f3722216db068dad2eba95
Reviewed-on: https://go-review.googlesource.com/133275
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

For some reason on darwin the linker still can't add debug sections to
plugins. Executables importing "plugin" do have them, however.

Because of issue 25841, plugins on darwin would likely have bad debug
info anyway so, for now, this isn't a great loss.

This disables the check for debug sections in plugins for darwin only.

Updates #27502

Change-Id: Ib8f62dac1e485006b0c2b3ba04f86d733db5ee9a
Reviewed-on: https://go-review.googlesource.com/133435Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

File is compiled with "-l" flag, so go:noinline is redundant.

Change-Id: Ia269f3b9de9466857fc578ba5164613393e82369
Reviewed-on: https://go-review.googlesource.com/133295Reviewed-by: Cherry Zhang <cherryyz@google.com>

Fixes #27258

Change-Id: I1ac75087e2b811e6479990e12d71f2c1f4f47b64
Reviewed-on: https://go-review.googlesource.com/132015Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

On linux/ppc64{,le} the SYS_SYNC_FILE_RANGE2 syscall is used to
implement SyncFileRange. This syscall has a different argument order
than SYS_SYNC_FILE_RANGE. Apart from that the implementations of both
syscalls are the same, so use a simple wrapper to invoke the syscall
with the correct argument order.

For context see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=edd5cd4a9424f22b0fa08bef5e299d41befd5622

Updates #27485

Change-Id: Ib94fb98376bf6c879df6f1b68c3bdd11ebcb5a44
Reviewed-on: https://go-review.googlesource.com/133195
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>