This change adds Conn and RawConn interfaces which can be used to
manipulate raw network connection end points typically represented as
socket descriptors.

Fixes #19435.

Change-Id: Ide2d28eeab91bfd27473ab47a87bec69950b64c9
Reviewed-on: https://go-review.googlesource.com/37913
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Ic6d2de92e1f533a9f9a0cd6d7dab463bdafb0e11
Reviewed-on: https://go-review.googlesource.com/43691Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>

Change-Id: If5cb80c3c086684ce6c2e8ed9bb23b2a20c8aacd
Reviewed-on: https://go-review.googlesource.com/43690Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Recent CL 41834 made windows Stat work for all symlinks.
But CL 41834 also made Stat slow.

John Starks sugested
(see https://github.com/golang/go/issues/19922#issuecomment-300031421)
to use GetFileAttributesEx for files and directories instead.
This makes Stat as fast as at go1.9.

I see these improvements on my Windows 7

name       old time/op  new time/op  delta
StatDot    26.5µs ± 1%  20.6µs ± 2%  -22.37%  (p=0.000 n=9+10)
StatFile   22.8µs ± 2%   6.2µs ± 1%  -72.69%  (p=0.000 n=10+10)
StatDir    21.0µs ± 2%   6.1µs ± 3%  -71.12%  (p=0.000 n=10+9)
LstatDot   20.1µs ± 1%  20.7µs ± 6%   +3.37%  (p=0.000 n=9+10)
LstatFile  6.23µs ± 1%  6.36µs ± 8%     ~     (p=0.587 n=9+10)
LstatDir   6.10µs ± 0%  6.14µs ± 4%     ~     (p=0.590 n=9+10)

and on my Windows XP

name         old time/op  new time/op  delta
StatDot-2    20.6µs ± 0%  10.8µs ± 0%  -47.44%  (p=0.000 n=10+10)
StatFile-2   20.2µs ± 0%   7.9µs ± 0%  -60.91%  (p=0.000 n=8+10)
StatDir-2    19.3µs ± 0%   7.6µs ± 0%  -60.51%  (p=0.000 n=10+9)
LstatDot-2   10.8µs ± 0%  10.8µs ± 0%   -0.48%  (p=0.000 n=10+8)
LstatFile-2  7.83µs ± 0%  7.83µs ± 0%     ~     (p=0.844 n=10+8)
LstatDir-2   7.59µs ± 0%  7.56µs ± 0%   -0.46%  (p=0.000 n=10+10)

Updates #19922

Change-Id: Ice1fb5825defb05c79bab4dec0692e0fd1bcfcd5
Reviewed-on: https://go-review.googlesource.com/43071Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I4b8f1b61c10f60ddb3687759af0be1641c1f78ce
Reviewed-on: https://go-review.googlesource.com/43111Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

TestScopeRanges has been added in CL 40095. This
test is failing on Plan 9 because executables don't
have a DWARF symbol table.

Fixes #20418.

Change-Id: I6dd3baa636998134ccd042203c8b5c3199a4d6e1
Reviewed-on: https://go-review.googlesource.com/43670
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

This slightly clarifies the just-submitted CL 40577.

Updates #19647

Change-Id: I5584ad0e1abbc31796e3e5752351857f2a13d6d7
Reviewed-on: https://go-review.googlesource.com/43625
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change compiler and linker to emit DWARF lexical blocks in .debug_info
section when compiling with -N -l.

Version of debug_info is updated from DWARF v2 to DWARF v3 since
version 2 does not allow lexical blocks with discontinuous PC ranges.

Remaining open problems:
- scope information is removed from inlined functions
- variables records do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, even before its declaration.

Updates #6913.
Updates #12899.

Change-Id: Idc6808788512ea20e7e45bcf782453acb416fb49
Reviewed-on: https://go-review.googlesource.com/40095
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Fixes #19647

Change-Id: Ife4f98cf2c55ee9490843797213dae2f2647b0a3
Reviewed-on: https://go-review.googlesource.com/40577Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

A number of issues in decoder.Read and newlineFilteringReader.Read were
preventing errors from the reader supplying the encoded data from being
propagated to the caller.  Fixing these issues revealed some additional
problems in which valid decoded data was not always returned to the user
when errors were actually propagated.

This commit fixes both the error propagation and the lost decoded data
problems.  It also adds some new unit tests to ensure errors are handled
correctly by decoder.Read.  The new unit tests increase the test coverage
of this package from 96.2% to 97.9%.

Fixes #20044

Change-Id: I1a8632da20135906e2d191c2a8825b10e7ecc4c5
Reviewed-on: https://go-review.googlesource.com/42094Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

These are functional tests, so it is safe to gofmt them.

Change-Id: I3067279c1d49809ac6a62054448ab8a6c3de9bda
Reviewed-on: https://go-review.googlesource.com/43623Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Previously all arguments were passed through driver.IsValid.
This checked arguments against a few fundamental go types and
prevented others from being passed in as arguments.

The new interface driver.NamedValueChecker may be implemented
by both driver.Stmt and driver.Conn. This allows
this new interface to completely supersede the
driver.ColumnConverter interface as it can be used for
checking arguments known to a prepared statement and
arbitrary query arguments. The NamedValueChecker may be
skipped with driver.ErrSkip after all special cases are
exhausted to use the default argument converter.

In addition if driver.ErrRemoveArgument is returned
the argument will not be passed to the query at all,
useful for passing in driver specific per-query options.

Add a canonical Out argument wrapper to be passed
to OUTPUT parameters. This will unify checks that need to
be written in the NameValueChecker.

The statement number check is also moved to the argument
converter so the NamedValueChecker may remove arguments
passed to the query.

Fixes #13567
Fixes #18079
Updates #18417
Updates #17834
Updates #16235
Updates #13067
Updates #19797

Change-Id: I89088bd9cca4596a48bba37bfd20d987453ef237
Reviewed-on: https://go-review.googlesource.com/38533Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Cannot reproduce original problem. Compiler internals
have changed enough such that this appears to work now.

Restore original test (exported interfaces), but also
keep version of the test using non-exported interfaces.

Fixes #15596.

Change-Id: Idb32da80239963242bd5d1609343c80f19773b0c
Reviewed-on: https://go-review.googlesource.com/43622
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Updates #18636

Change-Id: I143c670c3940231e29f1814e0a03165682f53243
Reviewed-on: https://go-review.googlesource.com/43621Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

The writebarrier pass processes WB ops from beginning to end,
replacing them by other values.
But it also checks whether there are more ops to process
by walking from beginning to end.
This is quadratic, so walk from end to beginning instead.

This speeds up compiling the code in issue 13554:

name  old time/op       new time/op       delta
Pkg         11.9s ± 2%         8.3s ± 3%  -29.88%  (p=0.000 n=18+17)

Updates #13554

Passes toolstash-check.

Change-Id: I5f8a872ddc4b783540220d89ea2ee188a6d2b2ff
Reviewed-on: https://go-review.googlesource.com/43571
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

looprotate finds loop headers and arranges for them to be placed
after the body of the loop. This eliminates a jump from the body.

However, if the loop header is a series of contiguously laid out blocks,
the rotation introduces a new jump in that series.
This CL expands the "loop header" to move to be the entire
run of contiguously laid out blocks in the same loop.

This shrinks object files a little, and actually speeds up
the compiler noticeably. Numbers below.

Fannkuch performance seems to vary a lot by machine. On my laptop:

name          old time/op  new time/op  delta
Fannkuch11-8   2.89s ± 2%   2.85s ± 3%  -1.22%  (p=0.000 n=50+50)

This has a significant affect on the append benchmarks in #14758:

name   old time/op    new time/op    delta
Foo-8     312ns ± 3%     276ns ± 2%  -11.37%  (p=0.000 n=30+29)
Bar-8     565ns ± 2%     456ns ± 2%  -19.27%  (p=0.000 n=27+28)

Updates #18977
Fixes #20355

name        old time/op       new time/op       delta
Template          205ms ± 5%        204ms ± 8%    ~     (p=0.903 n=92+99)
Unicode          85.3ms ± 4%       85.1ms ± 3%    ~     (p=0.191 n=92+94)
GoTypes           512ms ± 4%        507ms ± 4%  -0.93%  (p=0.000 n=95+97)
Compiler          2.38s ± 3%        2.35s ± 3%  -1.27%  (p=0.000 n=98+95)
SSA               4.67s ± 3%        4.64s ± 3%  -0.62%  (p=0.000 n=95+96)
Flate             117ms ± 3%        117ms ± 3%    ~     (p=0.099 n=84+86)
GoParser          139ms ± 4%        137ms ± 4%  -0.90%  (p=0.000 n=97+98)
Reflect           329ms ± 5%        326ms ± 6%  -0.97%  (p=0.002 n=99+98)
Tar               102ms ± 6%        101ms ± 5%  -0.97%  (p=0.006 n=97+97)
XML               198ms ±10%        196ms ±13%    ~     (p=0.087 n=100+100)
[Geo mean]        318ms             316ms       -0.72%

name        old user-time/op  new user-time/op  delta
Template          250ms ± 7%        250ms ± 7%    ~     (p=0.850 n=94+92)
Unicode           107ms ± 8%        106ms ± 5%  -0.76%  (p=0.005 n=98+91)
GoTypes           665ms ± 5%        659ms ± 5%  -0.85%  (p=0.003 n=93+98)
Compiler          3.15s ± 3%        3.10s ± 3%  -1.60%  (p=0.000 n=99+98)
SSA               6.82s ± 3%        6.72s ± 4%  -1.55%  (p=0.000 n=94+98)
Flate             138ms ± 8%        138ms ± 6%    ~     (p=0.369 n=94+92)
GoParser          170ms ± 5%        168ms ± 6%  -1.13%  (p=0.002 n=96+98)
Reflect           412ms ± 8%        416ms ± 8%    ~     (p=0.169 n=100+100)
Tar               123ms ±18%        123ms ±14%    ~     (p=0.896 n=100+100)
XML               236ms ± 9%        234ms ±11%    ~     (p=0.124 n=100+100)
[Geo mean]        401ms             398ms       -0.63%

name        old alloc/op      new alloc/op      delta
Template         38.8MB ± 0%       38.8MB ± 0%    ~     (p=0.222 n=5+5)
Unicode          28.7MB ± 0%       28.7MB ± 0%    ~     (p=0.421 n=5+5)
GoTypes           109MB ± 0%        109MB ± 0%    ~     (p=0.056 n=5+5)
Compiler          457MB ± 0%        457MB ± 0%  +0.07%  (p=0.008 n=5+5)
SSA              1.10GB ± 0%       1.10GB ± 0%  +0.05%  (p=0.008 n=5+5)
Flate            24.5MB ± 0%       24.5MB ± 0%    ~     (p=0.222 n=5+5)
GoParser         30.9MB ± 0%       31.0MB ± 0%  +0.21%  (p=0.016 n=5+5)
Reflect          73.4MB ± 0%       73.4MB ± 0%    ~     (p=0.421 n=5+5)
Tar              25.5MB ± 0%       25.5MB ± 0%    ~     (p=0.548 n=5+5)
XML              40.9MB ± 0%       40.9MB ± 0%    ~     (p=0.151 n=5+5)
[Geo mean]       71.6MB            71.6MB       +0.07%

name        old allocs/op     new allocs/op     delta
Template           394k ± 0%         394k ± 0%    ~     (p=1.000 n=5+5)
Unicode            344k ± 0%         343k ± 0%    ~     (p=0.310 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=1.000 n=5+5)
Compiler          4.42M ± 0%        4.42M ± 0%    ~     (p=1.000 n=5+5)
SSA               9.80M ± 0%        9.80M ± 0%    ~     (p=0.095 n=5+5)
Flate              237k ± 1%         238k ± 1%    ~     (p=0.310 n=5+5)
GoParser           320k ± 0%         322k ± 1%  +0.50%  (p=0.032 n=5+5)
Reflect            958k ± 0%         957k ± 0%    ~     (p=0.548 n=5+5)
Tar                252k ± 1%         252k ± 0%    ~     (p=1.000 n=5+5)
XML                400k ± 0%         400k ± 0%    ~     (p=0.841 n=5+5)
[Geo mean]         741k              742k       +0.06%

name        old object-bytes  new object-bytes  delta
Template           386k ± 0%         386k ± 0%  -0.05%  (p=0.008 n=5+5)
Unicode            202k ± 0%         202k ± 0%  -0.01%  (p=0.008 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%  -0.06%  (p=0.008 n=5+5)
Compiler          3.91M ± 0%        3.91M ± 0%  -0.06%  (p=0.008 n=5+5)
SSA               7.91M ± 0%        7.92M ± 0%  +0.01%  (p=0.008 n=5+5)
Flate              228k ± 0%         227k ± 0%  -0.04%  (p=0.008 n=5+5)
GoParser           283k ± 0%         283k ± 0%  -0.06%  (p=0.008 n=5+5)
Reflect            952k ± 0%         951k ± 0%  -0.02%  (p=0.008 n=5+5)
Tar                187k ± 0%         187k ± 0%  -0.04%  (p=0.008 n=5+5)
XML                406k ± 0%         406k ± 0%  -0.05%  (p=0.008 n=5+5)
[Geo mean]         648k              648k       -0.04%

Change-Id: I8630c4291a0eb2f7e7927bc04d7cc0efef181094
Reviewed-on: https://go-review.googlesource.com/43491Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #20023

Change-Id: I1bec3e69031ffcfd7ad71716be9597ec322528ff
Reviewed-on: https://go-review.googlesource.com/41211Reviewed-by: Russ Cox <rsc@golang.org>

Updates #20227

Change-Id: Idadc3137490181a5d380367660cee21e8313cf3b
Reviewed-on: https://go-review.googlesource.com/42650
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

SWI only support "SWI $imm", but currently "SWI (Reg)" is also
accepted. This patch fixes it.

And more instruction tests are added to cmd/asm/internal/asm/testdata/arm.s

fixes #20375

Change-Id: Id437d853924a403e41da9b6cbddd20d994b624ff
Reviewed-on: https://go-review.googlesource.com/43552
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Ignore adapters with "Transport Name:   N/A" line in getmac
command output. This allows us to skip duplicate MAC addresses.

Fixes #19537.

Change-Id: I6b7be9d31322f963e02023c8f1037f6e9042b479
Reviewed-on: https://go-review.googlesource.com/39071Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Second attempt to fix #14710.

CL 35272 already tried to fix this issue. But CL 35272 assumed
that runtime.epclntab type is STEXT, while it is actually SRODATA.

This CL uses Symbol.Sect.Seg to determine if symbol is part
of Segtext or Segdata.

Fixes #14710

Change-Id: Ic6b6f657555c87a64d2bc36cc4c07ab0591d00c4
Reviewed-on: https://go-review.googlesource.com/42390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Iafeb8e033c876f482caa17cca414fe13b0fadb12
Reviewed-on: https://go-review.googlesource.com/43613
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

profileBuilder.locForPC returns 0 to mean "no location" because 0 is
an invalid location index. However, the code to build count profiles
doesn't check the result of locForPC, so this 0 location index ends up
in the profile's location list. This, in turn, causes problems later
when we decode the profile because it puts a nil *Location in the
sample's location slice, which can later lead to a nil pointer panic.

Fix this by making printCountProfile correctly discard the result of
locForPC if it returns 0. This makes this call match the other two
calls of locForPC.

Updates #15156.

Change-Id: I4492b3652b513448bc56f4cfece4e37da5e42f94
Reviewed-on: https://go-review.googlesource.com/43630Reviewed-by: Michael Matloob <matloob@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

TestGoroutineCounts was flaky when running on a system under load.
This happened on three builds the last couple of days.

Fix this by running this test with a single operating system thread, so
we do not depend on the operating system scheduler.  50 000 tests ran
without failure with the new version, the old version failed 0.5% of the
time.

Fixes #15156.

Change-Id: I1e5a18d0fef4f72cc9a56e376822b2849cdb0f8b
Reviewed-on: https://go-review.googlesource.com/43590Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

fuseBlockPlain was accidentally quadratic.
If you had plain blocks b1 -> b2 -> b3 -> b4,
each containing single values v1, v2, v3, and v4 respectively,
fuseBlockPlain would move v1 from b1 to b2 to b3 to b4,
then v2 from b2 to b3 to b4, etc.

There are two obvious fixes.

* Look for runs of blocks in fuseBlockPlain
  and handle them in a single go.
* Fuse from end to beginning; any given value in a run
  of blocks to fuse then moves only once.

The latter is much simpler, so that's what this CL does.

Somewhat surprisingly, this change does not pass toolstash-check.

The resulting set of blocks is the same,
and the values in them are the same,
but the order of values in them differ,
and that order of values (while arbitrary)
is enough to change the compiler's output.
This may be due to #20178; deadstore is the next pass after fuse.

Adding basic sorting to the beginning of deadstore
is enough to make this CL pass toolstash-check:

	for _, b := range f.Blocks {
		obj.SortSlice(b.Values, func(i, j int) bool { return b.Values[i].ID < b.Values[j].ID })
	}

Happily, this CL appears to result in better code on average,
if only by accident. It cuts 4k off of cmd/go; go1 benchmarks
are noisy as always but don't regress (numbers below).

No impact on the standard compilebench benchmarks.
For the code in #13554, this speeds up compilation dramatically:

name  old time/op       new time/op       delta
Pkg         53.1s ± 2%        12.8s ± 3%  -75.92%  (p=0.008 n=5+5)

name  old user-time/op  new user-time/op  delta
Pkg         55.0s ± 2%        14.9s ± 3%  -73.00%  (p=0.008 n=5+5)

name  old alloc/op      new alloc/op      delta
Pkg        2.04GB ± 0%       2.04GB ± 0%   +0.18%  (p=0.008 n=5+5)

name  old allocs/op     new allocs/op     delta
Pkg         6.21M ± 0%        6.21M ± 0%     ~     (p=0.222 n=5+5)

name  old object-bytes  new object-bytes  delta
Pkg         28.4M ± 0%        28.4M ± 0%   +0.00%  (p=0.008 n=5+5)

name  old export-bytes  new export-bytes  delta
Pkg           208 ± 0%          208 ± 0%     ~     (all equal)


Updates #13554


go1 benchmarks:

name                     old time/op    new time/op    delta
BinaryTree17-8              2.29s ± 2%     2.26s ± 2%  -1.43%  (p=0.000 n=48+50)
Fannkuch11-8                2.74s ± 2%     2.79s ± 2%  +1.63%  (p=0.000 n=50+49)
FmtFprintfEmpty-8          36.6ns ± 3%    34.6ns ± 4%  -5.29%  (p=0.000 n=49+50)
FmtFprintfString-8         58.3ns ± 3%    59.1ns ± 3%  +1.35%  (p=0.000 n=50+49)
FmtFprintfInt-8            62.4ns ± 2%    63.2ns ± 3%  +1.19%  (p=0.000 n=49+49)
FmtFprintfIntInt-8         95.1ns ± 2%    96.7ns ± 3%  +1.61%  (p=0.000 n=49+50)
FmtFprintfPrefixedInt-8     118ns ± 3%     113ns ± 2%  -4.00%  (p=0.000 n=50+49)
FmtFprintfFloat-8           191ns ± 2%     192ns ± 2%  +0.40%  (p=0.034 n=50+50)
FmtManyArgs-8               419ns ± 2%     420ns ± 2%    ~     (p=0.228 n=49+49)
GobDecode-8                5.26ms ± 3%    5.19ms ± 2%  -1.33%  (p=0.000 n=50+49)
GobEncode-8                4.12ms ± 2%    4.15ms ± 3%  +0.68%  (p=0.007 n=49+50)
Gzip-8                      198ms ± 2%     197ms ± 2%  -0.50%  (p=0.018 n=48+48)
Gunzip-8                   31.9ms ± 3%    31.8ms ± 3%  -0.47%  (p=0.024 n=50+50)
HTTPClientServer-8         64.4µs ± 0%    64.0µs ± 0%  -0.55%  (p=0.000 n=43+46)
JSONEncode-8               10.6ms ± 2%    10.6ms ± 3%    ~     (p=0.543 n=49+49)
JSONDecode-8               43.3ms ± 3%    43.1ms ± 2%    ~     (p=0.079 n=50+50)
Mandelbrot200-8            3.70ms ± 2%    3.70ms ± 2%    ~     (p=0.553 n=47+50)
GoParse-8                  2.70ms ± 2%    2.71ms ± 3%    ~     (p=0.843 n=49+50)
RegexpMatchEasy0_32-8      70.5ns ± 4%    70.4ns ± 4%    ~     (p=0.867 n=48+50)
RegexpMatchEasy0_1K-8       162ns ± 3%     162ns ± 2%    ~     (p=0.739 n=48+48)
RegexpMatchEasy1_32-8      66.1ns ± 5%    66.2ns ± 4%    ~     (p=0.970 n=50+50)
RegexpMatchEasy1_1K-8       297ns ± 7%     296ns ± 7%    ~     (p=0.406 n=50+50)
RegexpMatchMedium_32-8      105ns ± 5%     105ns ± 5%    ~     (p=0.702 n=50+50)
RegexpMatchMedium_1K-8     32.3µs ± 4%    32.2µs ± 3%    ~     (p=0.614 n=49+49)
RegexpMatchHard_32-8       1.75µs ±18%    1.74µs ±12%    ~     (p=0.738 n=50+48)
RegexpMatchHard_1K-8       52.2µs ±14%    51.3µs ±13%    ~     (p=0.230 n=50+50)
Revcomp-8                   366ms ± 3%     367ms ± 3%    ~     (p=0.745 n=49+49)
Template-8                 48.5ms ± 4%    48.5ms ± 4%    ~     (p=0.824 n=50+48)
TimeParse-8                 263ns ± 2%     256ns ± 2%  -2.98%  (p=0.000 n=48+49)
TimeFormat-8                265ns ± 3%     262ns ± 3%  -1.35%  (p=0.000 n=48+49)
[Geo mean]                 41.1µs         40.9µs       -0.48%


Change-Id: Ib35fa15b54282abb39c077d150beee27f610891a
Reviewed-on: https://go-review.googlesource.com/43570
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

When the race detector is enabled,
the compiler randomizes the order in which functions are compiled,
in an attempt to shake out bugs.
But we never re-seed the rand source, so every execution is identical.
Fix that to get more coverage.

Change-Id: If5cdde03ef4f1bab5f45e07f03fb6614945481d7
Reviewed-on: https://go-review.googlesource.com/43572
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Currently, cgo converts integer macros into int64 if it's possible.
As a result, some macros which satisfy

math.MaxInt64 < x <= math.MaxUint64

will lose their original values.

This CL introduces the new probe to check signs,
so we can handle signed ints and unsigned ints separately.

Fixes #20369

Change-Id: I002ba452a82514b3a87440960473676f842cc9ee
Reviewed-on: https://go-review.googlesource.com/43476Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The generated file runtime/internal/sys/zversion.go is deleted by
`go tool cmd dist clean` as part of running clean.bash. Don't treat
a missing file as a reason to stop running the go tool; just treat
is as meaning that runtime/internal/sys is stale.

No test because I don't particularly want to clobber $GOROOT.

Fixes #20385.

Change-Id: I5251a99542cc93c33f627f133d7118df56e18af1
Reviewed-on: https://go-review.googlesource.com/43559
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #20365.

Change-Id: If1a4866193cff3bc836d8bbf18b6a1f5deb9808d
Reviewed-on: https://go-review.googlesource.com/43550
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>

Restore the handling of io.ErrShortWrite in (*File).Write:
if we write less than the requested amount, and there is no error from
the syscall, then return io.ErrShortWrite.

I can't figure out how to write a test for this. It would require a
non-pollable file (not a pipe) on a device that is almost but not
quite entirely full. The original code (https://golang.org/cl/36800043,
committed as part of https://golang.org/cl/36930044) does not have a test.

Fixes #20386.

Change-Id: Ied7b411e621e1eaf49f864f8db90069f276256f5
Reviewed-on: https://go-review.googlesource.com/43558
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

In low memory situations mmap(2) on Illumos[2] can return EAGAIN when it
is unable to reserve the necessary space for the requested mapping.  Go
was not previously handling this correctly for Illumos and would fail to
recognize it was in a low-memory situation, the result being the program
would terminate with a panic instead of running the GC.

Fixes: #14930

[1]: https://www.illumos.org/man/2/mmap

Change-Id: I889cc0547e23f9d6c56e4fdd7bcbd0e15403873a
Reviewed-on: https://go-review.googlesource.com/43461Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

On other systems we use "SWI $n". Change Plan 9 files to be
consistent. Generated binary is unchanged.

Fixes #20378.

Change-Id: Ia2a722061da2450c7b30cb707ed4f172fafecf74
Reviewed-on: https://go-review.googlesource.com/43533Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates #20164.

Change-Id: Ib900095e7885f25cd779750674a712c770603ca8
Reviewed-on: https://go-review.googlesource.com/42137Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

LLV and SCV are 64-bit load-linked and store-conditional. They
were used in runtime as #define WORD. Change them to normal
instruction form.

NOOP is hardware no-op. It was written as WORD $0. Make a name
for it for better disassembly output.

Fixes #12561.
Fixes #18238.

Change-Id: I82c667ce756fa83ef37b034b641e8c4366335e83
Reviewed-on: https://go-review.googlesource.com/40297Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This change adds several examples, with emphasis on special or edge
cases such as a directory parameter consisting of an empty string.

Change-Id: Ib4ac3d0f6d503493eeed0c4fda7c12acf782e9e2
Reviewed-on: https://go-review.googlesource.com/43010Reviewed-by: Steve Francia <spf@golang.org>
Run-TryBot: Jaana Burcu Dogan <jbd@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Noticed while looking at #20356.

Cuts 160k (1%) off of the cmd/compile binary.

Change-Id: If2397bc6971d6be9be6975048adecb0b5efa6d66
Reviewed-on: https://go-review.googlesource.com/43501
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

In Go 1.8.x, panics are generally scheduled at the very end of functions.
That property was lost in Go 1.9; this CL restores it.

This helps with the Fannkuch benchmark:

name          old time/op  new time/op  delta
Fannkuch11-8   2.74s ± 2%   2.55s ± 2%  -7.03%  (p=0.000 n=20+20)

This increases the fannkuch function size from 801 bytes to 831 bytes,
but that is still smaller than Go 1.8.1 at 844 bytes.

It generally increases binary size a tiny amount.
Negligible compiler performance impact.

For the code in #14758:

name   old time/op    new time/op    delta
Foo-8     326ns ± 3%     312ns ± 3%  -4.32%  (p=0.000 n=28+30)
Bar-8     560ns ± 2%     565ns ± 2%  +0.96%  (p=0.002 n=30+27)

Updates #18977

name        old alloc/op      new alloc/op      delta
Template         38.8MB ± 0%       38.8MB ± 0%    ~     (p=0.690 n=5+5)
Unicode          28.7MB ± 0%       28.7MB ± 0%    ~     (p=0.841 n=5+5)
GoTypes           109MB ± 0%        109MB ± 0%    ~     (p=0.690 n=5+5)
Compiler          457MB ± 0%        457MB ± 0%    ~     (p=0.841 n=5+5)
SSA              1.10GB ± 0%       1.10GB ± 0%  +0.03%  (p=0.032 n=5+5)
Flate            24.4MB ± 0%       24.5MB ± 0%    ~     (p=0.690 n=5+5)
GoParser         30.9MB ± 0%       30.9MB ± 0%    ~     (p=0.421 n=5+5)
Reflect          73.3MB ± 0%       73.3MB ± 0%    ~     (p=1.000 n=5+5)
Tar              25.5MB ± 0%       25.5MB ± 0%    ~     (p=0.095 n=5+5)
XML              40.8MB ± 0%       40.9MB ± 0%    ~     (p=0.056 n=5+5)
[Geo mean]       71.6MB            71.6MB       +0.01%

name        old allocs/op     new allocs/op     delta
Template           395k ± 0%         394k ± 1%    ~     (p=1.000 n=5+5)
Unicode            344k ± 0%         344k ± 0%    ~     (p=0.690 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=0.421 n=5+5)
Compiler          4.41M ± 0%        4.41M ± 0%    ~     (p=0.841 n=5+5)
SSA               9.79M ± 0%        9.79M ± 0%    ~     (p=0.310 n=5+5)
Flate              237k ± 0%         237k ± 0%    ~     (p=0.841 n=5+5)
GoParser           321k ± 0%         321k ± 1%    ~     (p=0.421 n=5+5)
Reflect            956k ± 0%         956k ± 0%    ~     (p=1.000 n=5+5)
Tar                251k ± 1%         252k ± 0%    ~     (p=0.095 n=5+5)
XML                399k ± 0%         400k ± 0%    ~     (p=0.222 n=5+5)
[Geo mean]         741k              741k       +0.03%

name        old object-bytes  new object-bytes  delta
Template           386k ± 0%         386k ± 0%  +0.05%  (p=0.008 n=5+5)
Unicode            202k ± 0%         202k ± 0%  +0.02%  (p=0.008 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%  +0.07%  (p=0.008 n=5+5)
Compiler          3.91M ± 0%        3.91M ± 0%  +0.05%  (p=0.008 n=5+5)
SSA               7.86M ± 0%        7.87M ± 0%  +0.07%  (p=0.008 n=5+5)
Flate              227k ± 0%         227k ± 0%  +0.10%  (p=0.008 n=5+5)
GoParser           283k ± 0%         283k ± 0%  +0.04%  (p=0.008 n=5+5)
Reflect            950k ± 0%         951k ± 0%  +0.04%  (p=0.008 n=5+5)
Tar                187k ± 0%         187k ± 0%  -0.03%  (p=0.008 n=5+5)
XML                406k ± 0%         406k ± 0%  +0.04%  (p=0.008 n=5+5)
[Geo mean]         647k              647k       +0.04%

Change-Id: I2015aa26338b90cf41e47f89564e336dc02608df
Reviewed-on: https://go-review.googlesource.com/43293Reviewed-by: Keith Randall <khr@golang.org>

Previous CL (cmd/internal/objabi: shrink SymType down to a uint8) shrinks
SymType down to a uint8 but forgot making according change in goobj.

Fixes #20296
Also add a test to catch such Goobj format inconsistency bug

Change-Id: Ib43dd7122cfcacf611a643814e95f8c5a924941f
Reviewed-on: https://go-review.googlesource.com/42971
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Mark variables as used even when they appear within an expression
context which we can't type-check; e.g., because the expression is
erroneous, or comes from an import "C" declaration.

Fixes #20358.

Change-Id: Ib28cc78d3867c597c7a1ace54de09ada02f5b33a
Reviewed-on: https://go-review.googlesource.com/43500Reviewed-by: Alan Donovan <adonovan@google.com>

Attaching positions to SB, SP, initial mem can result in
less-good line-numbering when compiled for debugging.
This "fix" also removes source position from a zero-valued
struct (but not from its fields) and from a zero-length
array constant.

This may be a general problem for constants in entry blocks.

Fixes #20367.

Change-Id: I7e9df3341be2e2f60f127d35bb31e43cdcfce9a1
Reviewed-on: https://go-review.googlesource.com/43531
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>