Without this, literals keep their original source positions through
inlining, which results in strange jumps in line numbers of inlined
function bodies. By copying literals, inlining can update their source
position like other nodes.

Fixes #15453.

Change-Id: Iad5d9bbfe183883794213266dc30e31bab89ee69
Reviewed-on: https://go-review.googlesource.com/37232
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

In order to generate accurate tracebacks, the runtime needs to know the
inlined call stack for a given PC. This creates two tables per function
for this purpose. The first table is the inlining tree (stored in the
function's funcdata), which has a node containing the file, line, and
function name for every inlined call. The second table is a PC-value
table that maps each PC to a node in the inlining tree (or -1 if the PC
is not the result of inlining).

To give the appearance that inlining hasn't happened, the runtime also
needs the original source position information of inlined AST nodes.
Previously the compiler plastered over the line numbers of inlined AST
nodes with the line number of the call. This meant that the PC-line
table mapped each PC to line number of the outermost call in its inlined
call stack, with no way to access the innermost line number.

Now the compiler retains line numbers of inlined AST nodes and writes
the innermost source position information to the PC-line and PC-file
tables. Some tools and tests expect to see outermost line numbers, so we
provide the OutermostLine function for displaying line info.

To keep track of the inlined call stack for an AST node, we extend the
src.PosBase type with an index into a global inlining tree. Every time
the compiler inlines a call, it creates a node in the global inlining
tree for the call, and writes its index to the PosBase of every inlined
AST node. The parent of this node is the inlining tree index of the
call. -1 signifies no parent.

For each function, the compiler creates a local inlining tree and a
PC-value table mapping each PC to an index in the local tree.  These are
written to an object file, which is read by the linker.  The linker
re-encodes these tables compactly by deduplicating function names and
file names.

This change increases the size of binaries by 4-5%. For example, this is
how the go1 benchmark binary is impacted by this change:

section             old bytes   new bytes   delta
.text               3.49M ± 0%  3.49M ± 0%   +0.06%
.rodata             1.12M ± 0%  1.21M ± 0%   +8.21%
.gopclntab          1.50M ± 0%  1.68M ± 0%  +11.89%
.debug_line          338k ± 0%   435k ± 0%  +28.78%
Total               9.21M ± 0%  9.58M ± 0%   +4.01%

Updates #19348.

Change-Id: Ic4f180c3b516018138236b0c35e0218270d957d3
Reviewed-on: https://go-review.googlesource.com/37231
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

This reduces compiler memory usage by up to 4% - see compilebench
results below.

name       old time/op     new time/op     delta
Template       245ms ± 4%      241ms ± 2%  -1.88%  (p=0.029 n=10+10)
Unicode        126ms ± 3%      124ms ± 3%    ~     (p=0.105 n=10+10)
GoTypes        805ms ± 2%      813ms ± 3%    ~     (p=0.515 n=8+10)
Compiler       3.95s ± 2%      3.83s ± 1%  -2.96%  (p=0.000 n=9+10)
MakeBash       47.4s ± 4%      46.6s ± 1%  -1.59%  (p=0.028 n=9+10)

name       old user-ns/op  new user-ns/op  delta
Template        324M ± 5%       326M ± 3%    ~     (p=0.935 n=10+10)
Unicode         186M ± 5%       178M ±10%    ~     (p=0.067 n=9+10)
GoTypes        1.08G ± 7%      1.09G ± 4%    ~     (p=0.956 n=10+10)
Compiler       5.34G ± 4%      5.31G ± 1%    ~     (p=0.501 n=10+8)

name       old alloc/op    new alloc/op    delta
Template      41.0MB ± 0%     39.8MB ± 0%  -3.03%  (p=0.000 n=10+10)
Unicode       32.3MB ± 0%     31.0MB ± 0%  -4.13%  (p=0.000 n=10+10)
GoTypes        119MB ± 0%      116MB ± 0%  -2.39%  (p=0.000 n=10+10)
Compiler       499MB ± 0%      487MB ± 0%  -2.48%  (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        380k ± 1%       379k ± 1%    ~     (p=0.436 n=10+10)
Unicode         324k ± 1%       324k ± 0%    ~     (p=0.853 n=10+10)
GoTypes        1.15M ± 0%      1.15M ± 0%    ~     (p=0.481 n=10+10)
Compiler       4.41M ± 0%      4.41M ± 0%  -0.12%  (p=0.007 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       623k ± 0%       623k ± 0%    ~     (all equal)
CmdGoSize      6.64M ± 0%      6.64M ± 0%    ~     (all equal)

name       old data-bytes  new data-bytes  delta
HelloSize      5.81k ± 0%      5.81k ± 0%    ~     (all equal)
CmdGoSize       238k ± 0%       238k ± 0%    ~     (all equal)

name       old bss-bytes   new bss-bytes   delta
HelloSize       134k ± 0%       134k ± 0%    ~     (all equal)
CmdGoSize       152k ± 0%       152k ± 0%    ~     (all equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       967k ± 0%       967k ± 0%    ~     (all equal)
CmdGoSize      10.2M ± 0%      10.2M ± 0%    ~     (all equal)

Change-Id: I1f40af738254892bd6c8ba2eb43390b175753d52
Reviewed-on: https://go-review.googlesource.com/37445Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Adds a function for easily accessing the x509.Certificate
of a Server, if there is one. Also adds a helper function
for getting a http.Client suitable for use with the server.

This makes the steps required to test a httptest
TLS server simpler.

Fixes #18411

Change-Id: I2e78fe1e54e31bed9c641be2d9a099f698c7bbde
Reviewed-on: https://go-review.googlesource.com/34639Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I90865921584ae4bdfb6c220d439b14593d72b6f9
Reviewed-on: https://go-review.googlesource.com/37752
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The Zero op right after newobject has been removed. But this rule
does not cover Store of constant zero (for SSA-able types). Add
rules to cover Store op as well.

Updates #19027.

Change-Id: I5d2b62eeca0aa9ce8dc7205b264b779de01c660b
Reviewed-on: https://go-review.googlesource.com/36836
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

On amd64p32, PtrSize and RegSize don't agree, and function return
value is aligned with RegSize. Fix this rule. Other architectures
are not affected, where PtrSize and RegSize are the same.

Change-Id: If187d3dfde3dc3b931b8e97db5eeff49a781551b
Reviewed-on: https://go-review.googlesource.com/37720
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Previously the compiler rewrote constant division into OHMUL
operations, but that rewriting was moved to SSA in CL 37015. Now OHMUL
is unused, so we can get rid of it.

Change-Id: Ib6fc7c2b6435510bafb5735b3b4f42cfd8ed8cdb
Reviewed-on: https://go-review.googlesource.com/37750
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

There are two accesses to mheap_.busy that are guarded by checks
against len(mheap_.free). This works because both lists are (and must
be) the same length, but it makes the code less clear. Change these to
use len(mheap_.busy) so the access more clearly parallels the check.

Fixes #18944.

Change-Id: I9bacbd3663988df351ed4396ae9018bc71018311
Reviewed-on: https://go-review.googlesource.com/36354
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

Currently sweep counts the number of allocated objects, computes the
number of free objects from that, then re-computes the number of
allocated objects from that. Simplify and clean this up by skipping
these intermediate steps.

Change-Id: I3ed98e371eb54bbcab7c8530466c4ab5fde35f0a
Reviewed-on: https://go-review.googlesource.com/34935
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>
Reviewed-by: Rick Hudson <rlh@golang.org>

Currently we scan the finalizers queue both during concurrent mark and
during mark termination. This costs roughly 20ns per queued finalizer
and about 1ns per unused finalizer queue slot (allocated queue length
never decreases), which can drive up STW time if there are many
finalizers.

However, we only add finalizers to this queue during sweeping, which
means that the second scan will never find anything new. Hence, we can
fix this by simply not scanning the finalizers queue during mark
termination. This brings the STW time under the 100µs goal even with
1,000,000 queued finalizers.

Fixes #18869.

Change-Id: I4ce5620c66fb7f13ebeb39ca313ce57047d1d0fb
Reviewed-on: https://go-review.googlesource.com/36013
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

Since workbuf is now marked go:notinheap, the write barrier-preventing
wrapper type wbufptr is no longer necessary. Remove it.

Change-Id: I3e5b5803a1547d65de1c1a9c22458a38e08549b7
Reviewed-on: https://go-review.googlesource.com/35971
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

The compiler's -d flag accepts string-valued flags, but currently only
for SSA debug flags. Extend it to support string values for other
flags. This also makes the syntax somewhat more sane so flag=value and
flag:value now both accept integers and strings.

Change-Id: Idd144d8479a430970cc1688f824bffe0a56ed2df
Reviewed-on: https://go-review.googlesource.com/37345
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

A value is "volatile" if it is a pointer to the argument region
on stack which will be clobbered by function call. This is used
to make sure the value is safe when inserting write barrier calls.
The writebarrier pass can tell whether a value is such a pointer.
Therefore no need to mark it when building SSA and thread this
information through.

Passes "toolstash -cmp" on std.

Updates #17583.

Change-Id: Idc5fc0d710152b94b3c504ce8db55ea9ff5b5195
Reviewed-on: https://go-review.googlesource.com/36835
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

This changes the decoder's behaviour when there is stray/extra data
found after an image is decompressed (e.g., data sub-blocks after an LZW
End of Information Code). Instead of raising an error, we silently skip
over such data until we find the end of the image data marked by a Block
Terminator. We skip at most one byte as sample problem GIFs exhibit this
property.

GIFs should not have and do not need such stray data (though the
specification is arguably ambiguous). However GIFs with such properties
have been seen in the wild.

Fixes #16146

Change-Id: Ie7e69052bab5256b4834992304e6ca58e93c1879
Reviewed-on: https://go-review.googlesource.com/37258Reviewed-by: Nigel Tao <nigeltao@golang.org>
Run-TryBot: Nigel Tao <nigeltao@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

p.m is accessed in WriteTo without holding p.mu.
Move the access inside the critical section.

The race detector catches this bug using this program:


package main

import (
	"os"
	"runtime/pprof"
	"time"
)

func main() {
	p := pprof.NewProfile("ABC")
	go func() {
		p.WriteTo(os.Stdout, 1)
		time.Sleep(time.Second)
	}()
	p.Add("abc", 0)
	time.Sleep(time.Second)
}


$ go run -race x.go 
==================
WARNING: DATA RACE
Write at 0x00c42007c240 by main goroutine:
  runtime.mapassign()
      /Users/josh/go/tip/src/runtime/hashmap.go:485 +0x0
  runtime/pprof.(*Profile).Add()
      /Users/josh/go/tip/src/runtime/pprof/pprof.go:281 +0x255
  main.main()
      /Users/josh/go/tip/src/p.go:15 +0x9d

Previous read at 0x00c42007c240 by goroutine 6:
  runtime/pprof.(*Profile).WriteTo()
      /Users/josh/go/tip/src/runtime/pprof/pprof.go:314 +0xc5
  main.main.func1()
      /Users/josh/go/tip/src/x.go:12 +0x69

Goroutine 6 (running) created at:
  main.main()
      /Users/josh/go/tip/src/x.go:11 +0x6e
==================
ABC profile: total 1
1 @ 0x110ccb4 0x111aeee 0x1055053 0x107f031

Found 1 data race(s)
exit status 66


(Exit status 66?)

Change-Id: I49d884dc3af9cce2209057a3448fe6bf50653523
Reviewed-on: https://go-review.googlesource.com/37730
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

There's no good reason to exclude it and it only makes the code more
complicated and less consistent. Having it in the list provides an
easy way to detect if a package uses operations from package unsafe.

Change-Id: I2f9b0485db0a680bd82f3b93a350b048db3f7701
Reviewed-on: https://go-review.googlesource.com/37694Reviewed-by: Alan Donovan <adonovan@google.com>

- renamed -a flag to -t
- added -x flag to specify external test files
- improved documentation and usage string

Change-Id: I7c850bd28a10ceaa55d599c22db07774147aa3f7
Reviewed-on: https://go-review.googlesource.com/37656Reviewed-by: Alan Donovan <adonovan@google.com>

The old code may have reported different errors given an
erroneous package depending on the order in which files
were parsed concurrently. The new code always reports
errors in "file order", independent of processing order.

Also:
- simplified parsing code and internal concurrency control
- removed -seq flag which didn't really add useful functionality

Change-Id: I18e24e630f458f2bc107a7b83926ae761d63c334
Reviewed-on: https://go-review.googlesource.com/37655Reviewed-by: Alan Donovan <adonovan@google.com>

This is now handled by os/exec.

Updates #12868

Change-Id: Ic21a6ff76a9b9517437ff1acf3a9195f9604bb45
Reviewed-on: https://go-review.googlesource.com/37698Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

If I put a 10 millisecond sleep at testHookWaitResLoop, before the big
select in (*persistConn).roundTrip, two flakes immediately started
happening, TestTransportBodyReadError (#19231) and
TestTransportPersistConnReadLoopEOF.

The problem was that there are many ways for a RoundTrip call to fail
(errors reading from Request.Body while writing the response, errors
writing the response, errors reading the response due to server
closes, errors due to servers sending malformed responses,
cancelations, timeouts, etc.), and many of those failures then tear
down the TCP connection, causing more failures, since there are always
at least three goroutines involved (reading, writing, RoundTripping).

Because the errors were communicated over buffered channels to a giant
select, the error returned to the caller was a function of which
random select case was called, which was why a 10ms delay before the
select brought out so many bugs. (several fixed in my previous CLs the past
few days).

Instead, track the error explicitly in the transportRequest, guarded
by a mutex.

In addition, this CL now:

* differentiates between the two ways writing a request can fail: the
  io.Copy reading from the Request.Body or the io.Copy writing to the
  network. A new io.Reader type notes read errors from the
  Request.Body. The read-from-body vs write-to-network errors are now
  prioritized differently.

* unifies the two mapRoundTripErrorFromXXX methods into one
  mapRoundTripError method since their logic is now the same.

* adds a (*Request).WithT(*testing.T) method in export_test.go, usable
  by tests, to call t.Logf at points during RoundTrip. This is disabled
  behind a constant except when debugging.

* documents and deflakes TestClientRedirectContext

I've tested this CL with high -count values, with/without -race,
with/without delays before the select, etc. So far it seems robust.

Fixes #19231 (TestTransportBodyReadError flake)
Updates #14203 (source of errors unclear; they're now tracked more)
Updates #15935 (document Transport errors more; at least understood more now)

Change-Id: I3cccc3607f369724b5344763e35ad2b7ea415738
Reviewed-on: https://go-review.googlesource.com/37495
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Using GetClientCertificate with the http client is currently completely
broken because inside the transport we clone the tls.Config and pass it
off to the tls.Client. Since tls.Config.Clone() does not pass forward
the GetClientCertificate field, GetClientCertificate is ignored in this
context.

Fixes #19264

Change-Id: Ie214f9f0039ac7c3a2dab8ffd14d30668bdb4c71
Signed-off-by: Mike Danese <mikedanese@google.com>
Reviewed-on: https://go-review.googlesource.com/37541Reviewed-by: Filippo Valsorda <hi@filippo.io>
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This reverts commit 9bd1cc3f.

Reason for revert: New fixes in from upstream. Try this again.

Change-Id: Iea46f32857e8467f8d5a49b31e20a52fda8bce60
Reviewed-on: https://go-review.googlesource.com/37693Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Now that vet loads from source,
fmt can always be correctly resolved,
so the fmt.Formatter type is always available,
so we can reinstate the check.

Change-Id: I17f0c7fccf6960c9415de8774b15123135d57be8
Reviewed-on: https://go-review.googlesource.com/37692
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This simplifies the code and speeds it up.
It also allows us to eliminate some other TODOs;
those will come in a follow-up CL.

Running for the host platform, before:

real	0m9.907s
user	0m14.566s
sys	0m1.058s

After:

real	0m7.841s
user	0m12.339s
sys	0m0.572s

Running for a single non-host platform, before:

real	0m8.784s
user	0m15.451s
sys	0m3.445s

After:

real	0m7.681s
user	0m12.122s
sys	0m0.577s

Running for all platforms, before:

real	7m4.480s
user	8m43.398s
sys	1m15.683s

After:

real	4m37.596s
user	7m30.729s
sys	0m18.533s

It also makes my laptop considerably more
responsive while running for all platforms.

Change-Id: I748689fea0d2d4ef61aca2ce5524d03d8fafa5ca
Reviewed-on: https://go-review.googlesource.com/37691Reviewed-by: Rob Pike <r@golang.org>

Add a -source flag to cmd/vet that instructs
it to typecheck purely from source code.

Updates #16086
Fixes #19332

Change-Id: Ic83d0f14d5bb837a329d539b2873aeccdf7bf669
Reviewed-on: https://go-review.googlesource.com/37690Reviewed-by: Rob Pike <r@golang.org>

Instead of constructing the importer in init, do it lazily as needed.
This lets us select the importer using a command line flag.
The addition of the command line flag will come in a follow-up CL.

Change-Id: Ieb3a5f01a34fb5bd220a95086daf5d6b37e83bb5
Reviewed-on: https://go-review.googlesource.com/37669Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

There's no guarantee that all in-progress mark assists will finish
before the trace does. Don't crash if that happens.

I haven't added a test because there's quite a bit of ceremony involved
and the bug is fairly straightforward.

Change-Id: Ia1369a8e2260fc6a328ad204a1eab1063d2e2c90
Reviewed-on: https://go-review.googlesource.com/37540Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #19359

Change-Id: I196b47cf0471915b6dc63785e8542aa1876ff695
Reviewed-on: https://go-review.googlesource.com/37665
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Fixes #19168.

Change-Id: I3f4fcc0b189c53819ac29ef8de86fdad76a17488
Reviewed-on: https://go-review.googlesource.com/37663Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I99706807782f11e8d24baf953424a9e292a2cbac
Reviewed-on: https://go-review.googlesource.com/37668
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This eliminates a duplicate copy of
the SizesFor map.

Change-Id: I51e44ea8ee860901086616e3f4dfa32aaa9b4d2d
Reviewed-on: https://go-review.googlesource.com/37667
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The current StdSizes most closely matches
the gc compiler, and the uses I know of that care
which compiler the sizes are for are all for
the gc compiler, so call the existing
implementation "gc".

Updates #17586
Fixes #19351

Change-Id: I2bdd694518fbe233473896321a1f9758b46ed79b
Reviewed-on: https://go-review.googlesource.com/37666
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Fixes #19323

Change-Id: I92d1bdefb15de6178a577a4fa0f0dc004f791904
Reviewed-on: https://go-review.googlesource.com/37584
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

The original analysis of the Go corpus assumed that these
stripped monotonic time. During the design discussion we
decided to try not stripping monotonic time here, but existing
code works better if we do.

See the discussion on golang.org/issue/18991 for more details.

For #18991.

Change-Id: I04d355ffe56ca0317acdd2ca76cb3033c277f6d1
Reviewed-on: https://go-review.googlesource.com/37542Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

It fails on Solaris often, but nowhere else.

Not sure why. Add some debugging.

Change-Id: I79fc710bd339ae972d624c73a46bd8d215729c10
Reviewed-on: https://go-review.googlesource.com/37659Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This is a follow-up to CL 36893.

Move the unlikely branch in the wrapper prologue to the end
of the function, where it has minimal impact on the instruction
cache. Static branch prediction is also less likely to choose
a forward branch.

Updates #19042

sort benchmarks:
name                  old time/op  new time/op  delta
SearchWrappers-4      1.44µs ± 0%  1.45µs ± 0%  +1.15%  (p=0.000 n=9+10)
SortString1K-4        1.02ms ± 0%  1.04ms ± 0%  +2.39%  (p=0.000 n=10+10)
SortString1K_Slice-4   960µs ± 0%   989µs ± 0%  +2.95%  (p=0.000 n=9+10)
StableString1K-4       218µs ± 0%   213µs ± 0%  -2.13%  (p=0.000 n=10+10)
SortInt1K-4            541µs ± 0%   543µs ± 0%  +0.30%  (p=0.003 n=9+10)
StableInt1K-4          760µs ± 1%   763µs ± 1%  +0.38%  (p=0.011 n=10+10)
StableInt1K_Slice-4    840µs ± 1%   779µs ± 0%  -7.31%  (p=0.000 n=9+10)
SortInt64K-4          55.2ms ± 0%  55.4ms ± 1%  +0.34%  (p=0.012 n=10+8)
SortInt64K_Slice-4    56.2ms ± 0%  55.6ms ± 1%  -1.16%  (p=0.000 n=10+10)
StableInt64K-4        70.9ms ± 1%  71.0ms ± 0%    ~     (p=0.315 n=10+7)
Sort1e2-4              250µs ± 0%   249µs ± 1%    ~     (p=0.315 n=9+10)
Stable1e2-4            600µs ± 0%   594µs ± 0%  -1.09%  (p=0.000 n=9+10)
Sort1e4-4             51.2ms ± 0%  51.4ms ± 1%  +0.40%  (p=0.001 n=9+10)
Stable1e4-4            204ms ± 1%   199ms ± 1%  -2.27%  (p=0.000 n=10+10)
Sort1e6-4              8.42s ± 0%   8.44s ± 0%  +0.28%  (p=0.000 n=8+9)
Stable1e6-4            43.3s ± 0%   42.5s ± 1%  -1.89%  (p=0.000 n=9+9)

Change-Id: I827559aa557fdba211a38ce3f77137b471c5c67e
Reviewed-on: https://go-review.googlesource.com/37611
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

The test assumed that passing an unknown option to the Fortran
compiler would cause the compiler to fail. Unfortunately it appears
that some succeed. It's irrelevant to the actual test, which is
verifying that the flag was indeed passed.

Fixes #19080.

Change-Id: Ib9e89447a2104e4742f4b98938373fc2522772aa
Reviewed-on: https://go-review.googlesource.com/37658
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Fixes #19069.

Change-Id: I211a304ec57d6b94366af4c0db413c8055b9634d
Reviewed-on: https://go-review.googlesource.com/37531Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Steve Francia <spf@golang.org>

Add golang.org/x/net/proxy from x/net git rev a689eb3bc4b5

Change-Id: I4ceb2cf5686042c545fe69868537a66e083139de
Reviewed-on: https://go-review.googlesource.com/35552Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>