This has a notable impact on systems with very large passwd files.

Before:
BenchmarkCurrent-12    	   30000	     42546 ns/op

After:
BenchmarkCurrent-12    	20000000	        77.5 ns/op

Saved in perf dashboard:
https://perf.golang.org/search?q=upload:20170206.1

Fixes #11625

Change-Id: Iebc9bf122cc64a4cab24ac06843c7b2bc450ded9
Reviewed-on: https://go-review.googlesource.com/36391Reviewed-by: Ian Lance Taylor <iant@golang.org>

Use fewer instructions to calculate the average of i and j without
overflowing at the addition.

Even if both i and j are math.MaxInt{32,64}, the sum fits into a
uint{32,64}. Because the sum of i and j is always ≥ 0, the right
shift by one does the same as a division by two. The result of the
shift operation is at most math.MaxInt{32,64} and fits again into
an int{32,64}.

name              old time/op  new time/op  delta
SearchWrappers-4   153ns ± 3%   143ns ± 6%  -6.33%  (p=0.000 n=90+100)

This calculation is documented in:
https://research.googleblog.com/2006/06/extra-extra-read-all-about-it-nearly.html

Change-Id: I2be7922afc03b3617fce32e59364606c37a83678
Reviewed-on: https://go-review.googlesource.com/36332Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This change defines WithLabels, Labels, Label, and ForLabels.
This is the first step of the profile labels implemention for go 1.9.

Updates #17280

Change-Id: I2dfc9aae90f7a4aa1ff7080d5747f0a1f0728e75
Reviewed-on: https://go-review.googlesource.com/34198
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Replace with generic rewrite rules.

Change-Id: I3ee32076cfd9db5801f1a7bdbb73a994255884a9
Reviewed-on: https://go-review.googlesource.com/36323
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>

It's not used, it's never been used, and it doesn't do what its doc
comment says it does.

Fixes #18941.

Change-Id: Ia89d97fb87525f5b861d7701f919e0d6b7cbd376
Reviewed-on: https://go-review.googlesource.com/36322Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Refs #12914.

Change-Id: Iadac4cbef70db6a95b47f86eaffcfc63bfdb8e90
Reviewed-on: https://go-review.googlesource.com/36334Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #18933.

Change-Id: I8bb98e95bb4486a086d93bcf99e3a37488e77b03
Reviewed-on: https://go-review.googlesource.com/36318
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Dir(`\\server\share`) returns `\\server\share.`. Change Dir so it
returns `\\server\share` instead.

Fixes #18783

Change-Id: I9e0dd71ea6aea85e6c6114aaa4bb3bea3270d818
Reviewed-on: https://go-review.googlesource.com/35690Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes build.

Change-Id: I2fee624c8a4b228bb9f2889e241ea016a317bb11
Reviewed-on: https://go-review.googlesource.com/36373
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

CL 18057 added underscore to most external pe symbols
on windows/386/cgo. The CL changed runtime.epclntab and
runtime.pclntab pe symbols into _runtime.pclntab and
_runtime.epclntab, and now cmd/nm cannot find them.
Revert correspondent CL 18057 changes, because most pe
symbols do not need underscore prefix.

This CL also removes code that added obj.SHOSTOBJ symbols
explicitly, because each of those was also added via
genasmsym call. These created duplicate pe symbols (like
_GetProcAddress@8 and __GetProcAddress@8), and external
linker would complain.

This CL adds new test in cmd/nm to verify go programs
built with cgo.

Fixes #18416

Change-Id: I68b1be8fb631d95ec69bd485c77c79604fb23f26
Reviewed-on: https://go-review.googlesource.com/35076Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Avoid confusing use of $(( in non-arithmetic context.

Permit added targets linux-386-387 linux-arm-arm5 to be correctly
matched against pattern argument.

Change-Id: Ib004c926457acb760c7e270fdd2f4095b1787a6d
Reviewed-on: https://go-review.googlesource.com/33492
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Passes toolstash -cmp.

Change-Id: I4a72e3e130c38868ee8ecef32cad58748aa5be52
Reviewed-on: https://go-review.googlesource.com/36353Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

No performance impact, just cleanup.

Passes toolstash -cmp.

Change-Id: Ic7957d2686de53a9680c2bdefe926cccccd73a5c
Reviewed-on: https://go-review.googlesource.com/36316
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Rather than collecting static data nodes to be written out later, just
write them out immediately.

Change-Id: I51708b690e94bc3e288b4d6ba3307bf738a80f64
Reviewed-on: https://go-review.googlesource.com/36352
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

go/build already ignores them, but they cause make.bash to fail.

Fixes #18931.

Change-Id: Idd5c8c2a6f2309ecd5f0d669660704d6f5612710
Reviewed-on: https://go-review.googlesource.com/36351
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently the net/rpc/jsonrpc package only implements JSON-RPC version
1.0. This change updates the package's documentation with link to find
packages for JSON-RPC 2.0.

Fixes #10929

Change-Id: I3b6f1d17738a1759d7b62ab7b3ecef5b248d30ca
Reviewed-on: https://go-review.googlesource.com/36330Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This CL fixes two issues:

1. Load ops were initially always lowered to unsigned loads, even
   for signed types. This was fine by itself however LoadReg ops
   (used to re-load spilled values) were lowered to signed loads
   for signed types. This meant that spills could invalidate
   optimizations that assumed the original unsigned load.

2. Types were not always being maintained correctly through rules
   designed to eliminate unnecessary zero and sign extensions.

Fixes #18906.

Change-Id: I95785dcadba03f7e3e94524677e7d8d3d3b9b737
Reviewed-on: https://go-review.googlesource.com/36256
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Address review comments from earlier CLs.
These are changes I was too scared to try to push
down into the original CLs (thanks, Git).

Change-Id: I0e428fad73d71bd2a7d08178cf2e856de3cef19f
Reviewed-on: https://go-review.googlesource.com/36257Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: Ib22fc435827d4a05a77a5200ac437ce00e2a4da3
Reviewed-on: https://go-review.googlesource.com/36204Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I05629567cc33fef41bc74eba4f7ff66e4851343c
Reviewed-on: https://go-review.googlesource.com/36203Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: Iec17bf2243de129942ae5fba126ec5f217be7303
Reviewed-on: https://go-review.googlesource.com/36202Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I2f349150659b6ddf6be4c675abba38dfe57ff652
Reviewed-on: https://go-review.googlesource.com/36201Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I28b20d53d20dff06eede574eb5c20359db0d3991
Reviewed-on: https://go-review.googlesource.com/36200Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I8e325d75f553b5d0b6224b56a705d2e2cb895de4
Reviewed-on: https://go-review.googlesource.com/36199Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I2d0ccdb84814537ab8b8842aa1b5f5bc0a88a0fc
Reviewed-on: https://go-review.googlesource.com/36198Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: Icdd181098f9f0e81f68bf201e6867cdd8f820300
Reviewed-on: https://go-review.googlesource.com/36197Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: Ic802483e50598def638f1e2e706d5fdf7822d32d
Reviewed-on: https://go-review.googlesource.com/36196Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I20dbc352c3df3c83a75811dd8e78c580a46b2202
Reviewed-on: https://go-review.googlesource.com/36195Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I4cf05b076d81b780c87a31378523929b5da8964b
Reviewed-on: https://go-review.googlesource.com/36194Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I7c5dde6e7fe4f390e6607303b4d42535c674eac3
Reviewed-on: https://go-review.googlesource.com/36193Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I6ee5b053683034ea9462a9a0a4ea4f5ad24fa5a1
Reviewed-on: https://go-review.googlesource.com/36192Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: Icb3f168ade91e7da5fcab89ac75b768daefff359
Reviewed-on: https://go-review.googlesource.com/36191Reviewed-by: David Crawshaw <crawshaw@golang.org>

This is one CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I63f578f5ac99c707b599ac5659293c46b275567d
Reviewed-on: https://go-review.googlesource.com/36190Reviewed-by: David Crawshaw <crawshaw@golang.org>

This CL makes a few naming changes to break dependencies
between different parts of the go command, to make it easier
to split into different packages.

This is the first CL in a long sequence of changes to break up the
go command from one package into a plausible group of packages.

This sequence is concerned only with moving code, not changing
or cleaning up code. There will still be more cleanup after this sequence.

The entire sequence will be submitted together: it is not a goal
for the tree to build at every step.

For #18653.

Change-Id: I69a98b9ea48e61b1e1cda95273d29860b525415f
Reviewed-on: https://go-review.googlesource.com/36129Reviewed-by: David Crawshaw <crawshaw@golang.org>

Before this CL, Go programs in c-archive or c-shared buildmodes
would not handle SIGPIPE. That leads to surprising behaviour where
writes on a closed pipe or socket would raise SIGPIPE and terminate
the program. This CL changes the Go runtime to handle
SIGPIPE regardless of buildmode. In addition, SIGPIPE from non-Go
code is forwarded.

This is a refinement of CL 32796 that fixes the case where a non-default
handler for SIGPIPE is installed by the host C program.

Fixes #17393

Change-Id: Ia41186e52c1ac209d0a594bae9904166ae7df7de
Reviewed-on: https://go-review.googlesource.com/35960
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

When the number of variables in a function is very large,
liveness analysis gets less efficient, since every bit vector
is O(number of variables).

Improve the situation by returning a sparse representation
from progeffects. In all scenarios, progeffects either
returns a slice that is shared function-wide, 
and which is usually small, or a slice that is guaranteed
to have at most three values.

Reduces compilation time for the code in #8225 Comment 1 by ~10%.
Minor effects on regular packages (below).

Passes toolstash -cmp.

Updates #8225

name       old time/op      new time/op      delta
Template        215ms ± 2%       212ms ± 4%  -1.31%  (p=0.001 n=30+30)
Unicode        98.3ms ± 3%      98.4ms ± 5%    ~     (p=0.971 n=30+30)
GoTypes         657ms ± 3%       651ms ± 2%  -0.98%  (p=0.001 n=30+27)
Compiler        2.78s ± 2%       2.77s ± 2%  -0.60%  (p=0.006 n=30+30)
Flate           130ms ± 4%       130ms ± 4%    ~     (p=0.712 n=29+30)
GoParser        159ms ± 5%       158ms ± 3%    ~     (p=0.331 n=29+30)
Reflect         406ms ± 3%       404ms ± 3%  -0.69%  (p=0.041 n=29+30)
Tar             117ms ± 4%       117ms ± 3%    ~     (p=0.886 n=30+29)
XML             219ms ± 2%       217ms ± 2%    ~     (p=0.091 n=29+24)

name       old user-ns/op   new user-ns/op   delta
Template   272user-ms ± 3%  270user-ms ± 3%  -1.03%  (p=0.004 n=30+30)
Unicode    138user-ms ± 2%  138user-ms ± 3%    ~     (p=0.902 n=29+29)
GoTypes    891user-ms ± 2%  883user-ms ± 2%  -0.95%  (p=0.000 n=29+29)
Compiler   3.85user-s ± 2%  3.84user-s ± 2%    ~     (p=0.236 n=30+30)
Flate      167user-ms ± 2%  166user-ms ± 4%    ~     (p=0.511 n=28+30)
GoParser   211user-ms ± 4%  210user-ms ± 3%    ~     (p=0.287 n=29+30)
Reflect    539user-ms ± 3%  536user-ms ± 2%  -0.59%  (p=0.034 n=29+30)
Tar        154user-ms ± 3%  155user-ms ± 4%    ~     (p=0.786 n=30+30)
XML        289user-ms ± 3%  288user-ms ± 4%    ~     (p=0.249 n=30+26)

name       old alloc/op     new alloc/op     delta
Template       40.7MB ± 0%      40.8MB ± 0%  +0.09%  (p=0.001 n=30+30)
Unicode        30.8MB ± 0%      30.8MB ± 0%    ~     (p=0.112 n=30+30)
GoTypes         123MB ± 0%       124MB ± 0%  +0.09%  (p=0.000 n=30+30)
Compiler        473MB ± 0%       473MB ± 0%  +0.05%  (p=0.000 n=30+30)
Flate          26.5MB ± 0%      26.5MB ± 0%    ~     (p=0.186 n=29+30)
GoParser       32.3MB ± 0%      32.4MB ± 0%  +0.07%  (p=0.021 n=28+30)
Reflect        84.4MB ± 0%      84.6MB ± 0%  +0.21%  (p=0.000 n=30+30)
Tar            27.3MB ± 0%      27.3MB ± 0%  +0.09%  (p=0.010 n=30+28)
XML            44.7MB ± 0%      44.7MB ± 0%  +0.07%  (p=0.002 n=30+30)

name       old allocs/op    new allocs/op    delta
Template         401k ± 1%        400k ± 1%    ~     (p=0.321 n=30+30)
Unicode          331k ± 1%        331k ± 1%    ~     (p=0.357 n=30+28)
GoTypes         1.24M ± 0%       1.24M ± 1%  -0.19%  (p=0.001 n=30+30)
Compiler        4.27M ± 0%       4.27M ± 0%  -0.13%  (p=0.000 n=30+30)
Flate            252k ± 1%        251k ± 1%  -0.30%  (p=0.005 n=30+30)
GoParser         325k ± 1%        325k ± 1%    ~     (p=0.224 n=28+30)
Reflect         1.06M ± 0%       1.05M ± 0%  -0.34%  (p=0.000 n=30+30)
Tar              266k ± 1%        266k ± 1%    ~     (p=0.333 n=30+30)
XML              416k ± 1%        415k ± 1%    ~     (p=0.144 n=30+29)


Change-Id: I6ba67a9203516373062a2618122306da73333d98
Reviewed-on: https://go-review.googlesource.com/36211
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: I3b1317f0ab46e03d8c5a0af74c83183710a75055
Reviewed-on: https://go-review.googlesource.com/36214Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

See https://golang.org/design/12914-monotonic for details.

Fixes #12914.

Change-Id: I80edc2e6c012b4ace7161c84cf067d444381a009
Reviewed-on: https://go-review.googlesource.com/36255
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Caleb Spare <cespare@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

If there is a defer, and that defer recovers, then the caller
can see all of the output parameters.  That means that we must
mark all the output parameters live at any point which might panic.

If there is no defer then this is not necessary.  This is implemented.

We could also detect whether there is a recover in any of the defers.
If not, we would need to mark only output params that the defer
actually references (and the closure mechanism already does that).
This is not implemented.

Fixes #18860.

Change-Id: If984fe6686eddce9408bf25e725dd17fc16b8578
Reviewed-on: https://go-review.googlesource.com/36030Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

These rules trigger 116 times while running make.bash.
And at least for the sample code at
https://github.com/golang/go/issues/18906#issuecomment-277174241
they are providing optimizations not already present
in amd64.

Updates #18906

Change-Id: I410a480f566f5ab176fc573fb5ac74f9cffec225
Reviewed-on: https://go-review.googlesource.com/36217
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>