Popcnt has false dependency on output register and generates
MOVQ $0, reg to break it. But recently we switched MOVQ $0, reg
encoding from xor reg, reg  to actual mov $0, reg. This CL updates
code generation for popcnt to use actual XOR.

Change-Id: I4c1fc11e85758b53ba2679165fa55614ec54b27d
Reviewed-on: https://go-review.googlesource.com/82516
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Because getStackOffset is a function pointer, the compiler assumes that
its arguments escape. Pass a value instead to avoid heap allocations.

Change-Id: Ib94e5941847f134cd00e873040a4d7fcf15ced26
Reviewed-on: https://go-review.googlesource.com/92397
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Not a big improvement, but does help edge cases like the SSA package.
Change-Id: I40e531110b97efd5f45955be477fd0f4faa8d545
Reviewed-on: https://go-review.googlesource.com/92396
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Using bits.TrailingZeroes instead of iterating over each bit is a small
but easy win for the common case of only one or two registers being set.

I copied in the implementation for use with pre-1.9 bootstraps.

Change-Id: Ieaa768554d7d5239a5617fbf34f1ee0b32ce1de5
Reviewed-on: https://go-review.googlesource.com/92395
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Put everything that showed up in the allocation profile into the cache,
and reuse it across functions.

After this CL, the overhead of enabling location lists is getting
pretty close to the desired 5%:

compilecmp -all -beforeflags -dwarflocationlists=0 -afterflags -dwarflocationlists=1 -n 30 4ebad42292b6a4090faf37753dd768d2965e38c4 4ebad42292b6a4090faf37753dd768d2965e38c4
compilecmp  -dwarflocationlists=0 4ebad42292b6a4090faf37753dd768d2965e38c4  -dwarflocationlists=1 4ebad42292b6a4090faf37753dd768d2965e38c4
benchstat -geomean  /tmp/869550129 /tmp/143495132
completed   30 of   30, estimated time remaining 0s (eta 3:24PM)
name        old time/op       new time/op       delta
Template          199ms ± 4%        209ms ± 6%   +5.17%  (p=0.000 n=29+30)
Unicode          99.2ms ± 8%      100.5ms ± 6%     ~     (p=0.112 n=30+30)
GoTypes           642ms ± 3%        684ms ± 3%   +6.54%  (p=0.000 n=29+30)
SSA               8.00s ± 1%        8.71s ± 1%   +8.78%  (p=0.000 n=29+29)
Flate             129ms ± 7%        134ms ± 5%   +3.77%  (p=0.000 n=30+30)
GoParser          157ms ± 4%        164ms ± 5%   +4.35%  (p=0.000 n=29+30)
Reflect           428ms ± 3%        450ms ± 4%   +5.09%  (p=0.000 n=30+30)
Tar               195ms ± 5%        204ms ± 8%   +4.78%  (p=0.000 n=30+30)
XML               228ms ± 4%        241ms ± 4%   +5.62%  (p=0.000 n=30+29)
StdCmd            15.4s ± 1%        16.7s ± 1%   +8.29%  (p=0.000 n=29+29)
[Geo mean]        476ms             502ms        +5.35%

name        old user-time/op  new user-time/op  delta
Template          294ms ±18%        304ms ±15%     ~     (p=0.242 n=29+29)
Unicode           182ms ±27%        172ms ±28%     ~     (p=0.104 n=30+30)
GoTypes           957ms ±15%       1016ms ±12%   +6.16%  (p=0.000 n=30+30)
SSA               13.3s ± 5%        14.3s ± 3%   +7.32%  (p=0.000 n=30+28)
Flate             188ms ±17%        193ms ±17%     ~     (p=0.288 n=28+29)
GoParser          232ms ±16%        238ms ±13%     ~     (p=0.065 n=30+29)
Reflect           585ms ±13%        620ms ±10%   +5.88%  (p=0.000 n=30+30)
Tar               298ms ±21%        332ms ±23%  +11.32%  (p=0.000 n=30+30)
XML               329ms ±17%        343ms ±12%   +4.18%  (p=0.032 n=30+30)
[Geo mean]        492ms             513ms        +4.13%

name        old alloc/op      new alloc/op      delta
Template         38.3MB ± 0%       40.3MB ± 0%   +5.29%  (p=0.000 n=30+30)
Unicode          29.3MB ± 0%       29.6MB ± 0%   +1.28%  (p=0.000 n=30+29)
GoTypes           110MB ± 0%        118MB ± 0%   +6.97%  (p=0.000 n=29+30)
SSA              1.48GB ± 0%       1.61GB ± 0%   +9.06%  (p=0.000 n=30+30)
Flate            24.8MB ± 0%       26.0MB ± 0%   +4.99%  (p=0.000 n=29+30)
GoParser         30.9MB ± 0%       32.2MB ± 0%   +4.20%  (p=0.000 n=30+30)
Reflect          76.8MB ± 0%       80.6MB ± 0%   +4.97%  (p=0.000 n=30+30)
Tar              39.6MB ± 0%       41.7MB ± 0%   +5.22%  (p=0.000 n=29+30)
XML              42.0MB ± 0%       45.4MB ± 0%   +8.22%  (p=0.000 n=29+30)
[Geo mean]       63.9MB            67.5MB        +5.56%

name        old allocs/op     new allocs/op     delta
Template           383k ± 0%         405k ± 0%   +5.69%  (p=0.000 n=30+30)
Unicode            343k ± 0%         346k ± 0%   +0.98%  (p=0.000 n=30+27)
GoTypes           1.15M ± 0%        1.22M ± 0%   +6.17%  (p=0.000 n=29+29)
SSA               12.2M ± 0%        13.2M ± 0%   +8.15%  (p=0.000 n=30+30)
Flate              234k ± 0%         249k ± 0%   +6.44%  (p=0.000 n=30+30)
GoParser           315k ± 0%         332k ± 0%   +5.31%  (p=0.000 n=30+28)
Reflect            972k ± 0%        1010k ± 0%   +3.89%  (p=0.000 n=30+30)
Tar                394k ± 0%         415k ± 0%   +5.35%  (p=0.000 n=28+30)
XML                404k ± 0%         429k ± 0%   +6.31%  (p=0.000 n=29+29)
[Geo mean]         651k              686k        +5.35%

Change-Id: Ia005a8d6b33ce9f8091322f004376a3d6e5c1a94
Reviewed-on: https://go-review.googlesource.com/89357
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Completely redesign and reimplement location list generation to be more
efficient, and hopefully not too hard to understand.

RegKills are gone. Instead of using the regalloc's liveness
calculations, redo them using the Ops' clobber information. Besides
saving a lot of Values, this avoids adding RegKills to blocks that would
be empty otherwise, which was messing up optimizations. This does mean
that it's much harder to tell whether the generation process is buggy
(there's nothing to cross-check it with), and there may be disagreements
with GC liveness. But the performance gain is significant, and it's nice
not to be messing with earlier compiler phases.

The intermediate representations are gone. Instead of producing
ssa.BlockDebugs, then dwarf.LocationLists, and then finally real
location lists, go directly from the SSA to a (mostly) real location
list. Because the SSA analysis happens before assembly, it stores
encoded block/value IDs where PCs would normally go. It would be easier
to do the SSA analysis after assembly, but I didn't want to retain the
SSA just for that.

Generation proceeds in two phases: first, it traverses the function in
CFG order, storing the state of the block at the beginning and end. End
states are used to produce the start states of the successor blocks. In
the second phase, it traverses in program text order and produces the
location lists. The processing in the second phase is redundant, but
much cheaper than storing the intermediate representation. It might be
possible to combine the two phases somewhat to take advantage of cases
where the CFG matches the block layout, but I haven't tried.

Location lists are finalized by adding a base address selection entry,
translating each encoded block/value ID to a real PC, and adding the
terminating zero entry. This probably won't work on OSX, where dsymutil
will choke on the base address selection. I tried emitting CU-relative
relocations for each address, and it was *very* bad for performance --
it uses more memory storing all the relocations than it does for the
actual location list bytes. I think I'm going to end up synthesizing the
relocations in the linker only on OSX, but TBD.

TestNexting needs updating: with more optimizations working, the
debugger doesn't stop on the continue (line 88) any more, and the test's
duplicate suppression kicks in. Also, dx and dy live a little longer
now, but they have the correct values.

Change-Id: Ie772dfe23a4e389ca573624fac4d05401ae32307
Reviewed-on: https://go-review.googlesource.com/89356
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

We're trying to enable location lists by default, and it's easier to do
that if we don't have to worry about scope tracking at the same time.
We can evaluate their performance impact separately.

However, that does mean that "err" is ambiguous in the test case, so
rename it to err2 for now.

Change-Id: I24f119016185c52b7d9affc74207f6a5b450fb6f
Reviewed-on: https://go-review.googlesource.com/89355
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

By default futexes are permitted in shared memory regions, which
requires the kernel to translate the memory address. Since our futexes
are never in shared memory, set FUTEX_PRIVATE_FLAG, which makes futex
operations slightly more efficient.

Change-Id: I2a82365ed27d5cd8d53c5382ebaca1a720a80952
Reviewed-on: https://go-review.googlesource.com/80144Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

The current assembler cannot handle PRFM(immediate) instruciton.
The fix creates a prfopfield struct that contains the eight
prefetch operations and the value to use in instruction. And add
the test cases.

Fixes #22932

Change-Id: I621d611bd930ef3c42306a4372447c46d53b2ccf
Reviewed-on: https://go-review.googlesource.com/81675
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Add support of NEG{V,W} pseudo-instructions, which are translated
to a SUB instruction from R0 with proper width.

Also turn illegal instruction to UNDEF, to avoid crashing in
asmout when it tries to read the operands.

Fixes #23548.

Change-Id: I047b27559ccd9594c3dcf62ab039b636098f30a3
Reviewed-on: https://go-review.googlesource.com/89896
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Just like all.bash passes flags to make.bash, I think it makes
sense that naclmake.bash and nacltest.bash do so as well. For
example, on a slow machine I can do "./nacltest.bash -v" to see
the build progress.

Change-Id: Id766dd590e6b83e8b5345822580dc1b05eac8ea3
Reviewed-on: https://go-review.googlesource.com/93117
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

On nacl/arm, R12 is clobbered by the RET instruction in function
that has a frame. runtime.udiv doesn't have a frame, so it does
not clobber R12.

Change-Id: I0de448749f615908f6659e92d201ba3eb2f8266d
Reviewed-on: https://go-review.googlesource.com/93116
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

If nil, fault before taking the lock or calling into the kernel.

Change-Id: I013d78a5f9233c2a9197660025f679940655d384
Reviewed-on: https://go-review.googlesource.com/93636
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Updates #23778.

Change-Id: I80e57a15b6e3bbc2e25ea186399ff0e360fc5c21
Reviewed-on: https://go-review.googlesource.com/93635
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Replace explicit range loop that applies orderexprinplace on a
list of nodes with existing helper function orderexprlistinplace.

Passes toolstash -cmp.

Change-Id: Ic8098ed08cf67f319de3faa83b00a5b73bbde95d
Reviewed-on: https://go-review.googlesource.com/88815Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I02938b2435e3a98efea7ee5545a6f8f5f6f794b4
Reviewed-on: https://go-review.googlesource.com/93915Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The tbz/tbnz checks the sign bit to determine if the value is >= 0 or < 0.

go1 benchmark results:
name                   old speed      new speed      delta
JSONEncode             94.4MB/s ± 1%  95.7MB/s ± 0%  +1.36%  (p=0.000 n=10+9)
JSONDecode             19.7MB/s ± 1%  19.9MB/s ± 1%  +1.08%  (p=0.000 n=9+10)
Gzip                   45.5MB/s ± 0%  46.0MB/s ± 0%  +1.06%  (p=0.000 n=10+10)
Revcomp                 376MB/s ± 0%   379MB/s ± 0%  +0.69%  (p=0.000 n=10+10)
RegexpMatchHard_1K     12.6MB/s ± 0%  12.7MB/s ± 0%  +0.57%  (p=0.000 n=10+8)
RegexpMatchMedium_32   3.21MB/s ± 0%  3.22MB/s ± 0%  +0.31%  (p=0.000 n=9+10)
RegexpMatchEasy1_1K    1.27GB/s ± 0%  1.27GB/s ± 0%  +0.23%  (p=0.000 n=9+9)
RegexpMatchHard_32     11.4MB/s ± 0%  11.4MB/s ± 1%  +0.19%  (p=0.036 n=10+8)
RegexpMatchEasy0_1K    1.77GB/s ± 0%  1.77GB/s ± 0%  +0.13%  (p=0.000 n=9+10)
RegexpMatchMedium_1K   19.3MB/s ± 0%  19.3MB/s ± 0%  +0.04%  (p=0.008 n=10+8)
RegexpMatchEasy0_32     131MB/s ± 0%   131MB/s ± 0%    ~     (p=0.211 n=10+10)
GobDecode              57.5MB/s ± 1%  57.6MB/s ± 2%    ~     (p=0.469 n=10+10)
GobEncode              58.6MB/s ± 1%  58.5MB/s ± 2%    ~     (p=0.781 n=10+10)
GoParse                9.40MB/s ± 0%  9.39MB/s ± 0%  -0.19%  (p=0.005 n=10+9)
RegexpMatchEasy1_32     133MB/s ± 0%   133MB/s ± 0%  -0.48%  (p=0.000 n=10+10)
Template               20.9MB/s ± 0%  20.6MB/s ± 0%  -1.54%  (p=0.000 n=8+10)

Change-Id: I411efe44db35c3962445618d5a47c12e31b3925b
Reviewed-on: https://go-review.googlesource.com/92715
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The pipe2 syscall is part of NetBSD since version 6.0 and thus exists in
all officially supported versions (6.0 through 6.1 and 7.0+).

Follows CL 38426

Change-Id: I7b62b507300c3dfbcc6ae56408a7d7088ddccc77
Reviewed-on: https://go-review.googlesource.com/94035
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The previous fix had "bug" and "build" in the wrong order.

Fixes #23791

Change-Id: I4897428516b159966c13c1054574c4f6fbf0fbac
Reviewed-on: https://go-review.googlesource.com/94017Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Include reader / writer interactions of RWMutex in the mutex profile.
Writer contention is already included in the profile, since a plain Mutex
is used to control exclusion.

Fixes #18496

Change-Id: Ib0dc1ffa0fd5e6d964a6f7764d7f09556eb63f00
Reviewed-on: https://go-review.googlesource.com/87095
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Peter Weinberger <pjw@google.com>

GCM allows using tag sizes smaller than the block size. This adds a
NewGCMWithNonceAndTagSize function which allows specifying the tag
size.

Fixes #19594

Change-Id: Ib2008c6f13ad6d916638b1523c0ded8a80eaf42d
Reviewed-on: https://go-review.googlesource.com/48510Reviewed-by: Filippo Valsorda <hi@filippo.io>
Run-TryBot: Filippo Valsorda <hi@filippo.io>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #23736

Change-Id: I850d91a512394c4292927d51c475064bfa4e3053
Reviewed-on: https://go-review.googlesource.com/92815Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Gccgo failed this test.

Updates #23620

Change-Id: I3979a6d3b87d2d014850accf9cb7f356349e6195
Reviewed-on: https://go-review.googlesource.com/91138
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

The stackguard is set to stackPreempt earlier in reentersyscall, and
as it comes with throwsplit = true there's no way for the stackguard
to be set to anything else by the end of reentersyscall.

Change-Id: I4e942005b22ac784c52398c74093ac887fc8ec24
Reviewed-on: https://go-review.googlesource.com/65673
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

FNMULS&FNMULD are efficient arm64 instructions, which can be used
to improve FP performance. This CL use them to optimize pairs of neg-mul
operations.

Here are benchmark test results on Raspberry Pi 3 with ArchLinux.

1. A special test case gets about 15% improvement.
(https://github.com/benshi001/ugo1/blob/master/fpmul_test.go)
FPMul-4                     485µs ± 0%     410µs ± 0%  -15.49%  (p=0.000 n=26+23)

2. There is little regression in the go1 benchmark (excluding noise).
name                     old time/op    new time/op    delta
BinaryTree17-4              42.0s ± 3%     42.1s ± 2%    ~     (p=0.542 n=39+40)
Fannkuch11-4                33.3s ± 3%     32.9s ± 1%    ~     (p=0.200 n=40+32)
FmtFprintfEmpty-4           534ns ± 0%     534ns ± 0%    ~     (all equal)
FmtFprintfString-4         1.09µs ± 1%    1.09µs ± 0%    ~     (p=0.950 n=32+32)
FmtFprintfInt-4            1.14µs ± 0%    1.14µs ± 1%    ~     (p=0.571 n=32+31)
FmtFprintfIntInt-4         1.79µs ± 3%    1.76µs ± 0%  -1.42%  (p=0.004 n=40+34)
FmtFprintfPrefixedInt-4    2.17µs ± 0%    2.17µs ± 0%    ~     (p=0.073 n=31+34)
FmtFprintfFloat-4          3.33µs ± 3%    3.28µs ± 0%  -1.46%  (p=0.001 n=40+34)
FmtManyArgs-4              7.28µs ± 6%    7.19µs ± 0%    ~     (p=0.641 n=40+33)
GobDecode-4                96.5ms ± 4%    96.5ms ± 9%    ~     (p=0.214 n=40+40)
GobEncode-4                79.5ms ± 0%    80.7ms ± 4%  +1.51%  (p=0.000 n=34+40)
Gzip-4                      4.53s ± 4%     4.56s ± 4%  +0.60%  (p=0.000 n=40+40)
Gunzip-4                    451ms ± 3%     442ms ± 0%  -1.93%  (p=0.000 n=40+32)
HTTPClientServer-4          530µs ± 1%     535µs ± 1%  +0.88%  (p=0.000 n=39+39)
JSONEncode-4                214ms ± 4%     211ms ± 0%    ~     (p=0.059 n=40+31)
JSONDecode-4                865ms ± 5%     864ms ± 4%  -0.06%  (p=0.003 n=40+40)
Mandelbrot200-4            52.0ms ± 3%    52.1ms ± 3%    ~     (p=0.556 n=40+40)
GoParse-4                  43.1ms ± 8%    42.1ms ± 0%    ~     (p=0.083 n=40+33)
RegexpMatchEasy0_32-4      1.02µs ± 3%    1.02µs ± 4%  +0.06%  (p=0.020 n=40+40)
RegexpMatchEasy0_1K-4      3.90µs ± 0%    3.96µs ± 3%  +1.58%  (p=0.000 n=31+40)
RegexpMatchEasy1_32-4       967ns ± 4%     981ns ± 3%  +1.40%  (p=0.000 n=40+40)
RegexpMatchEasy1_1K-4      6.41µs ± 4%    6.43µs ± 3%    ~     (p=0.386 n=40+40)
RegexpMatchMedium_32-4     1.76µs ± 3%    1.78µs ± 3%  +1.08%  (p=0.000 n=40+40)
RegexpMatchMedium_1K-4      561µs ± 0%     562µs ± 0%  +0.09%  (p=0.003 n=34+31)
RegexpMatchHard_32-4       31.5µs ± 2%    31.1µs ± 4%  -1.17%  (p=0.000 n=30+40)
RegexpMatchHard_1K-4        960µs ± 3%     950µs ± 4%  -1.02%  (p=0.016 n=40+40)
Revcomp-4                   7.79s ± 7%     7.79s ± 4%    ~     (p=0.859 n=40+40)
Template-4                  889ms ± 6%     872ms ± 3%  -1.86%  (p=0.025 n=40+31)
TimeParse-4                4.80µs ± 0%    4.89µs ± 3%  +1.71%  (p=0.001 n=31+40)
TimeFormat-4               4.70µs ± 1%    4.78µs ± 3%  +1.57%  (p=0.000 n=33+40)
[Geo mean]                  710µs          709µs       -0.13%

name                     old speed      new speed      delta
GobDecode-4              7.96MB/s ± 4%  7.96MB/s ± 9%    ~     (p=0.174 n=40+40)
GobEncode-4              9.65MB/s ± 0%  9.51MB/s ± 4%  -1.45%  (p=0.000 n=34+40)
Gzip-4                   4.29MB/s ± 4%  4.26MB/s ± 4%  -0.59%  (p=0.000 n=40+40)
Gunzip-4                 43.0MB/s ± 3%  43.9MB/s ± 0%  +1.90%  (p=0.000 n=40+32)
JSONEncode-4             9.09MB/s ± 4%  9.22MB/s ± 0%    ~     (p=0.429 n=40+31)
JSONDecode-4             2.25MB/s ± 5%  2.25MB/s ± 4%    ~     (p=0.278 n=40+40)
GoParse-4                1.35MB/s ± 7%  1.37MB/s ± 0%    ~     (p=0.071 n=40+25)
RegexpMatchEasy0_32-4    31.5MB/s ± 3%  31.5MB/s ± 4%  -0.08%  (p=0.018 n=40+40)
RegexpMatchEasy0_1K-4     263MB/s ± 0%   259MB/s ± 3%  -1.51%  (p=0.000 n=31+40)
RegexpMatchEasy1_32-4    33.1MB/s ± 4%  32.6MB/s ± 3%  -1.38%  (p=0.000 n=40+40)
RegexpMatchEasy1_1K-4     160MB/s ± 4%   159MB/s ± 3%    ~     (p=0.364 n=40+40)
RegexpMatchMedium_32-4    565kB/s ± 3%   562kB/s ± 2%    ~     (p=0.208 n=40+40)
RegexpMatchMedium_1K-4   1.82MB/s ± 0%  1.82MB/s ± 0%  -0.27%  (p=0.000 n=34+31)
RegexpMatchHard_32-4     1.02MB/s ± 3%  1.03MB/s ± 4%  +1.04%  (p=0.000 n=32+40)
RegexpMatchHard_1K-4     1.07MB/s ± 4%  1.08MB/s ± 4%  +0.94%  (p=0.003 n=40+40)
Revcomp-4                32.6MB/s ± 7%  32.6MB/s ± 4%    ~     (p=0.965 n=40+40)
Template-4               2.18MB/s ± 6%  2.22MB/s ± 3%  +1.83%  (p=0.020 n=40+31)
[Geo mean]               7.77MB/s       7.78MB/s       +0.16%

3. There is little change in the compilecmp benchmark (excluding noise).
name        old time/op       new time/op       delta
Template          2.37s ± 3%        2.35s ± 4%    ~     (p=0.529 n=10+10)
Unicode           1.38s ± 8%        1.36s ± 5%    ~     (p=0.247 n=10+10)
GoTypes           8.10s ± 2%        8.10s ± 2%    ~     (p=0.971 n=10+10)
Compiler          40.5s ± 4%        40.8s ± 1%    ~     (p=0.529 n=10+10)
SSA                115s ± 2%         115s ± 3%    ~     (p=0.684 n=10+10)
Flate             1.45s ± 5%        1.46s ± 3%    ~     (p=0.796 n=10+10)
GoParser          1.86s ± 4%        1.84s ± 2%    ~     (p=0.095 n=9+10)
Reflect           5.11s ± 2%        5.13s ± 2%    ~     (p=0.315 n=10+10)
Tar               2.22s ± 3%        2.23s ± 1%    ~     (p=0.299 n=9+7)
XML               2.72s ± 3%        2.72s ± 3%    ~     (p=0.912 n=10+10)
[Geo mean]        5.03s             5.02s       -0.21%

name        old user-time/op  new user-time/op  delta
Template          2.92s ± 2%        2.89s ± 1%    ~     (p=0.247 n=10+10)
Unicode           1.71s ± 5%        1.69s ± 4%    ~     (p=0.393 n=10+10)
GoTypes           9.78s ± 2%        9.76s ± 2%    ~     (p=0.631 n=10+10)
Compiler          49.1s ± 2%        49.1s ± 1%    ~     (p=0.796 n=10+10)
SSA                144s ± 1%         144s ± 2%    ~     (p=0.796 n=10+10)
Flate             1.74s ± 2%        1.73s ± 3%    ~     (p=0.842 n=10+9)
GoParser          2.23s ± 3%        2.25s ± 2%    ~     (p=0.143 n=10+10)
Reflect           5.93s ± 3%        5.98s ± 2%    ~     (p=0.211 n=10+9)
Tar               2.65s ± 2%        2.69s ± 3%  +1.51%  (p=0.010 n=9+10)
XML               3.25s ± 2%        3.21s ± 1%  -1.24%  (p=0.035 n=10+9)
[Geo mean]        6.07s             6.07s       -0.08%

name        old text-bytes    new text-bytes    delta
HelloSize         641kB ± 0%        641kB ± 0%    ~     (all equal)

name        old data-bytes    new data-bytes    delta
HelloSize        9.46kB ± 0%       9.46kB ± 0%    ~     (all equal)

name        old bss-bytes     new bss-bytes     delta
HelloSize         125kB ± 0%        125kB ± 0%    ~     (all equal)

name        old exe-bytes     new exe-bytes     delta
HelloSize        1.24MB ± 0%       1.24MB ± 0%    ~     (all equal)

Change-Id: Id095d998c380eef929755124084df02446a6b7c1
Reviewed-on: https://go-review.googlesource.com/92555
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Increase the sleep and wait for up to 2 seconds for the dup2.
Apparently it can sometimes take a long time.

Fixes #23784

Change-Id: I929530b057bbcd842b28a7640c39dd68d719ff7d
Reviewed-on: https://go-review.googlesource.com/93895
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Backslashes are ignored in Match and Glob on Windows, since those
collide with the separator character. However, they should still work in
both functions on other operating systems.

hasMeta did not reflect this logic - it always treated a backslash as a
non-special character. Do that only on Windows.

Assuming this is what the TODO was referring to, remove it. There are no
other characters that scanChunk treats especially.

Fixes #23418.

Change-Id: Ie0bd795812e0ed9d8c8c1bbc3137f29d960cba84
Reviewed-on: https://go-review.googlesource.com/87455
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

path.Match works purely with strings, not file paths. That's what sets
it apart from filepath.Match. For example, only filepath.Match will
change its behavior towards backslashes on Windows, to accomodate for
the file path separator on that system.

As such, path.Match should make no mention of file names. Nor should
path.ErrBadPattern mention globbing at all - the package has no notion
of globbing, and the error concerns only patterns.

For a similar reason, remove the mention of globbing from
filepath.ErrBadPattern. The error isn't reserved to just globbing, as it
can be returned from filepath.Match. And, as before, it only concerns
the patterns themselves.

Change-Id: I58a83ffa3e2549625d8e546ef916652525504bd1
Reviewed-on: https://go-review.googlesource.com/87857Reviewed-by: Rob Pike <r@golang.org>

Fatalf calls in two Float tests use the %s verb with Floats values,
which is not allowed and results in failure messages that look like
this:

    float_test.go:1385: i = 0, prec = 1, ToZero:
                     %!s(*big.Float=1) [0]
                /    %!s(*big.Float=1) [0]
                =    %!s(*big.Float=0.0625)
                want %!s(*big.Float=1)

Switch to %v.

Change-Id: Ifdc80bf19c91ca1b190f6551a6d0a51b42ed5919
Reviewed-on: https://go-review.googlesource.com/87199
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

ordercopyexpr is only called with 0 or 1 as value for the clear
argument. The clear variable in ordercopyexpr is only used in the
call to ordertemp which has a clear argument of type bool.

Change the clear argument of ordercopyexpr from int to bool and change
calls to ordercopyexpr to use false instead of 0 and true instead of 1.

Passes toolstash -cmp.

Change-Id: Ic264aafd3b0c8b99f6ef028ffaa2e30f23f9125a
Reviewed-on: https://go-review.googlesource.com/88115Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

This makes the constant names less verbose and aligns them more
with the Linux kernel which uses HWCAP_XXX for the constant names.

Change-Id: Ia7d079b59b57978adc045945951eaa1d99b41fac
Reviewed-on: https://go-review.googlesource.com/91738
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also order the syscall number list by numerically for mips64x.

Follow-up for CL 92895.

Change-Id: I5f01f8c626132a06160997fce8a2aef0c486bb1c
Reviewed-on: https://go-review.googlesource.com/93616
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This moves the paragraph mentioning the use of _ higher up
to emphasize the warning and thereby reducing chances of getting
stuck.

Fixes #22617

Change-Id: I64352a3e966a22d86fc9d381332bade49d74714a
Reviewed-on: https://go-review.googlesource.com/87375Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #23574

Change-Id: I69573de47daa6fd53cc99a78c0c4b867460242e3
Reviewed-on: https://go-review.googlesource.com/90275Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

The sub-word shifts need to sign-extend before shifting, to avoid
bringing in data from higher in the argument.

Fixes #23812

Change-Id: I0a95a0b49c48f3b40b85765bb4a9bb492be0cd73
Reviewed-on: https://go-review.googlesource.com/93716
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

As usual, adding go1.11 early in the cycle so that we can start
regression testing of the master toolchain.

Change-Id: Ie96eca7223722d60d7acc6b3b996b76740c36419
Reviewed-on: https://go-review.googlesource.com/93775Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

CL 92916 added the GOMAXPROCS test in TestTraceSymbolize.

This test only succeeds when the value of GOMAXPROCS changes.

Since the test calls runtime.GOMAXPROCS(1), it will fails
on machines where GOMAXPROCS=1.

This change fixes the test by calling runtime.GOMAXPROCS(oldGoMaxProcs+1).

Fixes #23816.

Change-Id: I1183dbbd7db6077cbd7fa0754032ff32793b2195
Reviewed-on: https://go-review.googlesource.com/93735
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Id057dcc85d64e5c670710fbab6cacd4b906cf594
Reviewed-on: https://go-review.googlesource.com/93655
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It makes no sense to try to get the zero value of a nil type, hence the
panic. When we have a nil type, use reflect.ValueOf(nil) instead.

This was showing itself if one used a missing field on the data between
parentheses, when the data was a nil interface:

	t := template.Must(template.New("test").Parse(`{{ (.).foo }}`))
	var v interface{}
	t.Execute(os.Stdout, v)

Resulting in:

	panic: reflect: Zero(nil) [recovered]
		panic: reflect: Zero(nil)

Fixes #21171.

Change-Id: Ifcc4a0c67e6df425b65bc9f82fde6fcf03828579
Reviewed-on: https://go-review.googlesource.com/84482
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I8a6c3e225038cbeb315433fabf8835f582836d3e
Reviewed-on: https://go-review.googlesource.com/93657Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>