name       old secs    new secs    delta
LinkCmdGo   0.53 ± 9%   0.53 ±10%  -1.30%  (p=0.022 n=100+99)

name       old MaxRSS  new MaxRSS  delta
LinkCmdGo   151k ± 4%   142k ± 6%  -5.92%  (p=0.000 n=98+100)

Change-Id: Ic30e63a948f8e626b3396f458a0163f7234810c1
Reviewed-on: https://go-review.googlesource.com/21920
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: Iba40edc9ddad62534b06c5af20bbc3dd3dc14d0a
Reviewed-on: https://go-review.googlesource.com/21881Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Gccgo was erroneously marking Call results as addressable, which led to
an obscure bug using text/template, as text/template calls CanAddr to
check whether to take the address of a value when looking up methods.
When a function returned a pointer, and CanAddr was true, the result was
a pointer to a pointer that had no methods.

Fixed in gccgo by https://golang.org/cl/21908.  Adding the test here so
that it doesn't regress.

Change-Id: I1d25b868e1b8e2348b21cbac6404a636376d1a4a
Reviewed-on: https://go-review.googlesource.com/21930
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Use one comparison to detect underflow and overflow simultaneously.
Use a shift, bitwise complement and uint8 type conversion to handle
clamping to upper and lower bound without additional branching.

Overall the new code is faster for a mix of
common case, underflow and overflow.

name     old time/op  new time/op  delta
YCbCr-2  1.12ms ± 0%  0.64ms ± 0%  -43.01%  (p=0.000 n=48+47)

name              old time/op  new time/op  delta
YCbCrToRGB/0-2    5.52ns ± 0%  5.77ns ± 0%  +4.48%  (p=0.000 n=50+49)
YCbCrToRGB/128-2  6.05ns ± 0%  5.52ns ± 0%  -8.69%  (p=0.000 n=39+50)
YCbCrToRGB/255-2  5.80ns ± 0%  5.77ns ± 0%  -0.58%  (p=0.000 n=50+49)

Found in collaboration with Josh Bleecher Snyder and Ralph Corderoy.

Change-Id: Ic5020320f704966f545fdc1ae6bc24ddb5d3d09a
Reviewed-on: https://go-review.googlesource.com/21910Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #15262

Change-Id: I3eb1f6f71d6285d039f11ba6a34b8a599a33bf49
Reviewed-on: https://go-review.googlesource.com/21909
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Fixes the darwin/arm builder, which has a special test runner which
makes the assumption that tests never use testdata from another
package.

This looks large, but it's no more space in git.

Change-Id: I81921b516443d12d21b77617d323ddebedbe40f8
Reviewed-on: https://go-review.googlesource.com/21907Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Ie8323cfcd1193f390729d0d3dd67863aedf47d13
Reviewed-on: https://go-review.googlesource.com/21906
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Running

stress -p 1 go test -short std

on a heavily loaded machine causes net timeouts
every 15 or 20 runs.
Making these tests not run in parallel helps.
With this change, I haven’t seen a single failure
in over 100 runs.

Fixes #14986

Change-Id: Ibaa14869ce8d95b00266aee94d62d195927ede68
Reviewed-on: https://go-review.googlesource.com/21905
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Standardize on space between "RFC" and number. Additionally change
the couple "a RFC" instances to "an RFC."

Fixes #15258

Change-Id: I2b17ecd06be07dfbb4207c690f52a59ea9b04808
Reviewed-on: https://go-review.googlesource.com/21902Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Only splits into separate files, no other changes.

Change-Id: Icc0da2c5f18e03e9ed7c0043bd7c790f741900f2
Reviewed-on: https://go-review.googlesource.com/21804Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This is the first in a series of CLs to replace the use of pointers
in binary read-only data with offsets.

In standard Go binaries these CLs have a small effect, shrinking
8-byte pointers to 4-bytes. In position-independent code, it also
saves the dynamic relocation for the pointer. This has a significant
effect on the binary size when building as PIE, c-archive, or
c-shared.

darwin/amd64:
	cmd/go: -12KB (0.1%)
	jujud:  -82KB (0.1%)

linux/amd64 PIE:
	cmd/go:  -86KB (0.7%)
	jujud:  -569KB (0.7%)

For #6853.

Change-Id: Iad5625bbeba58dabfd4d334dbee3fcbfe04b2dcf
Reviewed-on: https://go-review.googlesource.com/21284Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

These builders (on Linaro) have a different network configuration
which is incompatible with this test. Or so it seems.

Updates #15191

Change-Id: Ibfeacddc98dac1da316e704b5c8491617a13e3bf
Reviewed-on: https://go-review.googlesource.com/21901Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Fixes #15225

Change-Id: I1f85590b2c3293463c6476beebcd3256adc1bf23
Reviewed-on: https://go-review.googlesource.com/21802Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14776

Change-Id: I55423ac643f18542b9fd1386ed98dec47fb678aa
Reviewed-on: https://go-review.googlesource.com/21890Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Passes toolstash -cmp.

Change-Id: Id504e71ed1f23900e24a9aed25143c94f4d7d50c
Reviewed-on: https://go-review.googlesource.com/21899
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

In the event of a partial write on Solaris and some BSDs, the offset
pointer passed to sendfile() will be updated even though the function
returns -1 if errno is set to EAGAIN/EINTR.  In that case, calculate the
bytes written based on the difference between the updated offset and the
original offset.  If no bytes were written, and errno is set to
EAGAIN/EINTR, ignore the errno.

Fixes #13892

Change-Id: I6334b5ef2edcbebdaa7db36fa4f7785967313c2d
Reviewed-on: https://go-review.googlesource.com/21769
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also: Adjust go/importer accordingly.

Change-Id: Ia6669563793e218946af45b9fba1cf986a21c031
Reviewed-on: https://go-review.googlesource.com/21896Reviewed-by: Alan Donovan <adonovan@google.com>

The disassembler is not yet implemented on s390x.

Updates #15255.

Change-Id: Ibab319c8c087b1a619baa1529398305c1e721877
Reviewed-on: https://go-review.googlesource.com/21894Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

s390x doesn't have sendfile64 so apply the same fix as MIPS
(eebf7d27) and just use sendfile.

Change-Id: If8fe2e974ed44a9883282430157c3545d5bd04bd
Reviewed-on: https://go-review.googlesource.com/21892Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Allows instructions with a From3 field to be used in regopt so
long as From3 represents a constant. This is needed because the
storage-to-storage instructions on s390x place the length of the
data into From3.

Change-Id: I12cd32d4f997baf2fe97937bb7d45bbf716dfcb5
Reviewed-on: https://go-review.googlesource.com/20875Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>

Fixes #15246
Re-opens #14969

Change-Id: Ic0b41c5aa42bbb229a0d62b7f3e5888c6b29293d
Reviewed-on: https://go-review.googlesource.com/21891
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

It seems cleaner and more consistent with other files to list the
architectures that have assembly implementations rather than to
list those that do not.

This means we don't have to add s390x and future platforms to this
list.

Change-Id: I2ad3f66b76eb1711333c910236ca7f5151b698e5
Reviewed-on: https://go-review.googlesource.com/21770Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I64ada9fe34c3cfc4bd514ec5d8c8f4d4c99074fb
Reviewed-on: https://go-review.googlesource.com/20950Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Needed for the header check to accept the header generated for
s390x as Go 1.2 style rather than Go 1.1 style.

Change-Id: I7b3713d4cc7514cfc58f947a45702348f6d7b824
Reviewed-on: https://go-review.googlesource.com/20966Reviewed-by: Minux Ma <minux@golang.org>

Load and store instructions are atomic on the s390x.

Change-Id: I0031ed2fba43f33863bca114d0fdec2e7d1ce807
Reviewed-on: https://go-review.googlesource.com/20938Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Most architectures can only generate nil checks when the
the address to check is in a register. Currently only
amd64 and 386 can generate checks for addresses that
reside in memory. This is unlikely to change so the architecture
check has been inverted.

Change-Id: I73697488a183406c79a9039c62823712b510bb6a
Reviewed-on: https://go-review.googlesource.com/21861Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

We need to make sure that when we combine loads, we only do
so if there are no other uses of the load.  We can't split
one load into two because that can then lead to inconsistent
loaded values in the presence of races.

Add some aggressive copy removal code so that phantom
"dead copy" uses of values are cleaned up promptly.  This lets
us use x.Uses==1 conditions reliably.

Change-Id: I9037311db85665f3868dbeb3adb3de5c20728b38
Reviewed-on: https://go-review.googlesource.com/21853Reviewed-by: Todd Neal <todd@tneal.org>

Make internal pprof packages available to cmd/trace.
cmd/trace needs access to them to generate symbolized
svg profiles (create and serialize Profile struct).
And potentially generate svg programmatically instead
of invoking go tool pprof.

Change-Id: Iafd0c87ffdd4ddc081093be0b39761f19507907a
Reviewed-on: https://go-review.googlesource.com/21870
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

These passes do not modify the dominator tree too much.

% benchstat old.txt new.txt
name       old time/op     new time/op     delta
Template       335ms ± 3%      325ms ± 8%    ~             (p=0.074 n=8+9)
GoTypes        1.05s ± 1%      1.05s ± 3%    ~            (p=0.095 n=9+10)
Compiler       5.37s ± 4%      5.29s ± 1%  -1.42%         (p=0.022 n=9+10)
MakeBash       34.9s ± 3%      34.4s ± 2%    ~            (p=0.095 n=9+10)

name       old alloc/op    new alloc/op    delta
Template      55.4MB ± 0%     54.9MB ± 0%  -0.81%        (p=0.000 n=10+10)
GoTypes        179MB ± 0%      178MB ± 0%  -0.89%        (p=0.000 n=10+10)
Compiler       807MB ± 0%      798MB ± 0%  -1.10%        (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        498k ± 0%       496k ± 0%  -0.29%          (p=0.000 n=9+9)
GoTypes        1.42M ± 0%      1.41M ± 0%  -0.24%        (p=0.000 n=10+10)
Compiler       5.61M ± 0%      5.60M ± 0%  -0.12%        (p=0.000 n=10+10)

Change-Id: I4cd20cfba3f132ebf371e16046ab14d7e42799ec
Reviewed-on: https://go-review.googlesource.com/21806
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

s390x does not require duffzero/duffcopy since it has
storage-to-storage instructions that can copy/clear up to 256
bytes at a time.

peep contains several new passes to optimize instruction
sequences that match s390x instructions such as the
compare-and-branch and load/store multiple instructions.

copyprop and subprop have been extended to work with moves that
require sign/zero extension. This work could be ported to other
architectures that do not used sized math however it does add
complexity and will probably be rendered unnecessary by ssa in
the near future.

Change-Id: I1b64b281b452ed82a85655a0df69cb224d2a6941
Reviewed-on: https://go-review.googlesource.com/20873
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #15102

Change-Id: I7fdb6464afd0b7af9b6652051416f0fddd34dc9a
Reviewed-on: https://go-review.googlesource.com/21730Reviewed-by: Austin Clements <austin@google.com>

Apply golang/tools@5804fef4c0556d3e5e7d2440740a3d7aced7d58b.

In the context of cmd/go build tool, import path is a '/'-separated path.
This can be inferred from `go help importpath` and `go help packages`.
vcsFromDir documentation says on return, root is the import path
corresponding to the root of the repository. On Windows and other
OSes where os.PathSeparator is not '/', that wasn't true since root
would contain characters other than '/', and therefore it wasn't a
valid import path corresponding to the root of the repository.
Fix that by using filepath.ToSlash.

Add test coverage for vcsFromDir, it was previously not tested.
It's taken from golang.org/x/tools/go/vcs tests, and modified to
improve style.

Additionally, remove an unneccessary statement from the documentation
"(thus root is a prefix of importPath)". There is no variable
importPath that is being referred to (it's possible p.ImportPath
was being referred to). Without it, the description of root value
matches the documentation of repoRoot.root struct field:

	// root is the import path corresponding to the root of the
	// repository
	root string

Rename and change signature of vcsForDir(p *Package) to
vcsFromDir(dir, srcRoot string). This is more in sync with the x/tools
version. It's also simpler, since vcsFromDir only needs those two
values from Package, and nothing more. Change "for" to "from" in name
because it's more consistent and clear.

Update usage of vcsFromDir to match the new signature, and respect
that returned root is a '/'-separated path rather than a os.PathSeparator
separated path.

Fixes #15040.
Updates #7723.
Helps #11490.

Change-Id: Idf51b9239f57248739daaa200aa1c6e633cb5f7f
Reviewed-on: https://go-review.googlesource.com/21345Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Removes dynimport, dynexport, dynlinker cases since they can not
be reached due to prefix check for "go:cgo_" in getlinepragma.

Replaces the if chains for verb distinction by a switch statement.
Replaces fmt.Sprintf by fmt.Sprintln for string concatenation.

Removes the more, getimpsym and getquoted functions by introducing a
pragmaFields function that partitions a pragma into its components.

Adds tests for cgo pragmas.

Change-Id: I43c7b9550feb3ddccaff7fb02198a3f994444123
Reviewed-on: https://go-review.googlesource.com/21607Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Needed by the build system to shard tests. nacl was the last unsharded
builder.

(I considered also adding a -make-only flag to nacltest.bash, but that
wouldn't fail fast when the file didn't exist.)

Updates #15242

Change-Id: I6afc1c1fe4268ab98c0724b5764c67d3784caebe
Reviewed-on: https://go-review.googlesource.com/21851Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Per RFC 5246, 7.4.1.3:

   cipher_suite
      The single cipher suite selected by the server from the list in
      ClientHello.cipher_suites.  For resumed sessions, this field is
      the value from the state of the session being resumed.

The specifications are not very clearly written about resuming sessions
at the wrong version (i.e. is the TLS 1.0 notion of "session" the same
type as the TLS 1.1 notion of "session"?). But every other
implementation enforces this check and not doing so has some odd
semantics.

Change-Id: I6234708bd02b636c25139d83b0d35381167e5cad
Reviewed-on: https://go-review.googlesource.com/21153Reviewed-by: Adam Langley <agl@golang.org>

Fixes #13849

Change-Id: Idd7f06b547a0179fe15571807a8c48b7c3b78d7c
Reviewed-on: https://go-review.googlesource.com/21852Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change makes String and MarshalText methods of IP return a
hexadecial form of IP with no punctuation as part of error
notification. It doesn't affect the existing behavior of ParseIP.

Also fixes bad shadowing in ipToSockaddr and makes use of reserved
IP address blocks for documnetation.

Fixes #15052.
Updates #15228.

Change-Id: I9e9ecce308952ed5683066c3d1bb6a7b36458c65
Reviewed-on: https://go-review.googlesource.com/21642Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Apparently we forgot to test this.

Fixes #15092

Change-Id: I33d4fef0f659dfbdfc1ebf8401e96610c8215592
Reviewed-on: https://go-review.googlesource.com/21860Reviewed-by: Robert Griesemer <gri@golang.org>

Passes on OpenBSD now when running it with -count=500.

Presumably this will also fix the same problems seen on FreeBSD and
Windows.

Fixes #15158

Change-Id: I86451c901613dfa5ecff0c2ecc516527a3c011b3
Reviewed-on: https://go-review.googlesource.com/21840
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

The way that -all works was unclear from the documentation and made
worse by recent changes to the flag package. Improve matters by making
the help message say "default true" for the tests that do default to true,
and tweak some of the wording.

Before:

Usage of vet:
	vet [flags] directory...
	vet [flags] files... # Must be a single package
For more information run
	go doc cmd/vet

Flags:
  -all
    	enable all non-experimental checks (default unset)
  -asmdecl
    	check assembly against Go declarations (default unset)
...

After:

Usage of vet:
	vet [flags] directory...
	vet [flags] files... # Must be a single package
By default, -all is set and all non-experimental checks are run.
For more information run
	go doc cmd/vet

Flags:
  -all
    	enable all non-experimental checks (default true)
  -asmdecl
    	check assembly against Go declarations (default true)
...

Change-Id: Ie94b27381a9ad2382a10a7542a93bce1d59fa8f5
Reviewed-on: https://go-review.googlesource.com/21495Reviewed-by: Andrew Gerrand <adg@golang.org>