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>

This speeds up compilation of the code in #8225 by 25%-30%.
The complexity of the algorithm is unchanged,
but this shrinks the constant factor so much that it doesn't matter,
even the size of the giant type switch gets scaled up dramatically.

name       old time/op      new time/op      delta
Template        218ms ± 5%       217ms ±10%    ~           (p=0.163 n=27+30)
Unicode        98.2ms ± 6%      97.7ms ±10%    ~           (p=0.150 n=27+29)
GoTypes         654ms ± 5%       650ms ± 5%    ~           (p=0.350 n=30+30)
Compiler        2.70s ± 4%       2.68s ± 3%    ~           (p=0.128 n=30+29)

name       old user-ns/op   new user-ns/op   delta
Template   276user-ms ± 6%  271user-ms ± 7%  -1.83%        (p=0.003 n=29+28)
Unicode    138user-ms ± 5%  137user-ms ± 4%    ~           (p=0.071 n=27+27)
GoTypes    881user-ms ± 4%  877user-ms ± 4%    ~           (p=0.423 n=30+30)
Compiler   3.76user-s ± 4%  3.72user-s ± 2%  -0.84%        (p=0.028 n=30+29)

name       old alloc/op     new alloc/op     delta
Template       40.7MB ± 0%      40.7MB ± 0%    ~           (p=0.936 n=30+30)
Unicode        30.8MB ± 0%      30.8MB ± 0%    ~           (p=0.859 n=28+30)
GoTypes         123MB ± 0%       123MB ± 0%    ~           (p=0.273 n=30+30)
Compiler        472MB ± 0%       472MB ± 0%    ~           (p=0.432 n=30+30)

name       old allocs/op    new allocs/op    delta
Template         401k ± 1%        401k ± 1%    ~           (p=0.859 n=30+30)
Unicode          331k ± 0%        331k ± 1%    ~           (p=0.823 n=28+30)
GoTypes         1.24M ± 0%       1.24M ± 0%    ~           (p=0.286 n=30+30)
Compiler        4.26M ± 0%       4.26M ± 0%    ~           (p=0.359 n=30+30)

Change-Id: Ia850065a9a84c07a5b0b4e23c1758b5679498da7
Reviewed-on: https://go-review.googlesource.com/36112
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

sigtramp was calling sigtrampgo and depending on the fact that
the 3rd argument slot will not be modified on return.  Our calling
convention doesn't guarantee that.  Avoid that assumption.

There's no actual bug here, as sigtrampgo does not in fact modify its
argument slots.  But I found this while working on the dead stack slot
clobbering tool.  https://go-review.googlesource.com/c/23924/

Change-Id: Ia7e791a2b4c1c74fff24cba8169e7840b4b06ffc
Reviewed-on: https://go-review.googlesource.com/36216
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The name lookups are unrooted; the test should be unrooted too.
Correctly skips the tests if the DNS config specifies a domain
suffix that has a wildcard entry causing all unrooted names to resolve.

Change-Id: I80470326a5d332f3b8d64663f765fd304c5e0811
Reviewed-on: https://go-review.googlesource.com/36253
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

name       old time/op      new time/op      delta
Template        218ms ± 3%       214ms ± 3%  -1.70%  (p=0.000 n=30+30)
Unicode         100ms ± 3%       100ms ± 4%    ~     (p=0.614 n=29+30)
GoTypes         657ms ± 1%       660ms ± 3%  +0.46%  (p=0.046 n=29+30)
Compiler        2.80s ± 2%       2.80s ± 1%    ~     (p=0.451 n=28+29)
Flate           131ms ± 2%       132ms ± 4%    ~     (p=1.000 n=29+29)
GoParser        159ms ± 3%       160ms ± 5%    ~     (p=0.341 n=28+30)
Reflect         406ms ± 3%       408ms ± 4%    ~     (p=0.511 n=28+30)
Tar             118ms ± 4%       118ms ± 4%    ~     (p=0.827 n=29+30)
XML             222ms ± 6%       222ms ± 3%    ~     (p=0.532 n=30+30)

name       old user-ns/op   new user-ns/op   delta
Template   274user-ms ± 3%  272user-ms ± 3%  -0.87%  (p=0.015 n=29+30)
Unicode    140user-ms ± 4%  140user-ms ± 3%    ~     (p=0.735 n=29+30)
GoTypes    890user-ms ± 1%  897user-ms ± 2%  +0.88%  (p=0.002 n=29+30)
Compiler   3.88user-s ± 2%  3.89user-s ± 1%    ~     (p=0.132 n=30+29)
Flate      168user-ms ± 2%  157user-ms ± 4%  -6.21%  (p=0.000 n=25+28)
GoParser   211user-ms ± 2%  213user-ms ± 5%    ~     (p=0.086 n=28+30)
Reflect    539user-ms ± 2%  541user-ms ± 3%    ~     (p=0.267 n=27+29)
Tar        156user-ms ± 7%  155user-ms ± 5%    ~     (p=0.708 n=30+30)
XML        291user-ms ± 5%  294user-ms ± 3%  +0.83%  (p=0.029 n=29+30)

name       old alloc/op     new alloc/op     delta
Template       40.7MB ± 0%      39.4MB ± 0%  -3.26%  (p=0.000 n=29+26)
Unicode        30.8MB ± 0%      30.7MB ± 0%  -0.40%  (p=0.000 n=28+30)
GoTypes         123MB ± 0%       119MB ± 0%  -3.47%  (p=0.000 n=30+29)
Compiler        472MB ± 0%       455MB ± 0%  -3.60%  (p=0.000 n=30+30)
Flate          26.5MB ± 0%      25.6MB ± 0%  -3.21%  (p=0.000 n=28+30)
GoParser       32.3MB ± 0%      31.4MB ± 0%  -2.98%  (p=0.000 n=29+30)
Reflect        84.4MB ± 0%      82.1MB ± 0%  -2.83%  (p=0.000 n=30+30)
Tar            27.3MB ± 0%      26.5MB ± 0%  -2.70%  (p=0.000 n=29+29)
XML            44.6MB ± 0%      43.1MB ± 0%  -3.49%  (p=0.000 n=30+30)

name       old allocs/op    new allocs/op    delta
Template         401k ± 1%        399k ± 0%  -0.35%  (p=0.000 n=30+28)
Unicode          331k ± 0%        331k ± 1%    ~     (p=0.907 n=28+30)
GoTypes         1.24M ± 0%       1.23M ± 0%  -0.43%  (p=0.000 n=30+30)
Compiler        4.26M ± 0%       4.25M ± 0%  -0.34%  (p=0.000 n=29+30)
Flate            252k ± 1%        251k ± 1%  -0.41%  (p=0.000 n=30+30)
GoParser         325k ± 1%        324k ± 1%  -0.31%  (p=0.000 n=27+30)
Reflect         1.06M ± 0%       1.05M ± 0%  -0.69%  (p=0.000 n=30+30)
Tar              266k ± 1%        265k ± 1%  -0.51%  (p=0.000 n=29+30)
XML              416k ± 1%        415k ± 1%  -0.36%  (p=0.002 n=30+30)

Change-Id: I8f784001324df83b2764c44f0e83a540e5beab34
Reviewed-on: https://go-review.googlesource.com/36212
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

It seems the problem is on gdb and the dynamic linker. Skip the
test for now until we figure out what's going on with the system.

Updates #18784.

Change-Id: Ic9320ffd463f6c231b2c4192652263b1cf7f4231
Reviewed-on: https://go-review.googlesource.com/36250
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I4fdd81aa7c9b180cb72ec4af3e7d9d803c99ecac
Reviewed-on: https://go-review.googlesource.com/36033Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I9ed5a2065cef06708e319b16c801da2eff42004e
Reviewed-on: https://go-review.googlesource.com/35497
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Fixes #18003.

Change-Id: Iadcc5c424c64badecfb5fdbd4dbd9197df56182c
Reviewed-on: https://go-review.googlesource.com/33421
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Also: Remove double "go:" prefix in related error message.

Fixes #18882.

Change-Id: Ifbbd8e2f7529b43f035d3dbf7ca4a91f212bc6b6
Reviewed-on: https://go-review.googlesource.com/36121
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

The existing darwin/amd64 implementation of runtime.nanotime returns the
wallclock time, which results in timers not functioning properly when
system time runs backwards. By implementing the algorithm used by the
darwin syscall mach_absolute_time, timers will function as expected.

The algorithm is described at
https://opensource.apple.com/source/xnu/xnu-3248.60.10/libsyscall/wrappers/mach_absolute_time.s

Fixes #17610

Change-Id: I9c8d35240d48249a6837dca1111b1406e2686f67
Reviewed-on: https://go-review.googlesource.com/35292Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #18402

Change-Id: I5af800857fb2e365ce4224eece9171277106ec7d
Reviewed-on: https://go-review.googlesource.com/35562
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Use (-x)>>63 instead of ((x-1)>>63)^-1 to get a mask that
is 0 when x is 0 and all ones when x is positive.

Saves one instruction when slicing.

Change-Id: Ib46d53d3aac6530ac481fa2f265a6eadf3df0567
Reviewed-on: https://go-review.googlesource.com/35641
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Based in part on khr's CL 2500.

Updates #17725
Updates #18121

Change-Id: I744e1f92fc2104e6c5bd883a898c30b2eea8cc31
Reviewed-on: https://go-review.googlesource.com/35555
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

The order pass is responsible for ensuring that
values passed to runtime functions, including
convT2E/convT2I, are addressable.

Prior to this CL, this was always accomplished
by creating a temp, which frequently escaped to
the heap, causing allocations, perhaps most
notably in code like:

fmt.Println(1, 2, 3) // allocates three times

None of the runtime routines modify the contents
of the pointers they receive, so in the case of
constants, instead of creating a temp value,
we can create a static value.

(Marking the static value as read-only provides
protection against accidental attempts by the runtime
to modify the constant data.)

This improves code generation for code like:

panic("abc")
c <- 2 // c is a chan int

which can now simply refer to "abc" and 2,
rather than going by way of a temporary.

It also allows us to optimize convT2E/convT2I,
by recognizing static readonly values
and directly constructing the interface.

This CL adds ~0.5% to binary size, despite
decreasing the size of many functions,
because it also adds many static symbols.

This binary size regression could be recovered in
future (but currently unplanned) work.

There is a lot of content-duplication in these
symbols; this statement generates six new symbols,
three containing an int 1 and three containing
a pointer to the string "a":

fmt.Println(1, 1, 1, "a", "a", "a")

These symbols could be made content-addressable.

Furthermore, these symbols are small, so the
alignment and naming overhead is large.
As with the go.strings section, these symbols
could be hidden and have their alignment reduced.

The changes to test/live.go make it impossible
(at least with current optimization techniques)
to place the values being passed to the runtime
in static symbols, preserving autotmp creation.

Fixes #18704

Benchmarks from fmt and go-kit's logging package:

github.com/go-kit/kit/log

name                      old time/op    new time/op    delta
JSONLoggerSimple-8          1.91µs ± 2%    2.11µs ±22%     ~     (p=1.000 n=9+10)
JSONLoggerContextual-8      2.60µs ± 6%    2.43µs ± 2%   -6.29%  (p=0.000 n=9+10)
Discard-8                    101ns ± 2%      34ns ±14%  -66.33%  (p=0.000 n=10+9)
OneWith-8                    161ns ± 1%     102ns ±16%  -36.78%  (p=0.000 n=10+10)
TwoWith-8                    175ns ± 3%     106ns ± 7%  -39.36%  (p=0.000 n=10+9)
TenWith-8                    293ns ± 3%     227ns ±15%  -22.44%  (p=0.000 n=9+10)
LogfmtLoggerSimple-8         704ns ± 2%     608ns ± 2%  -13.65%  (p=0.000 n=10+9)
LogfmtLoggerContextual-8     962ns ± 1%     860ns ±17%  -10.57%  (p=0.003 n=9+10)
NopLoggerSimple-8            188ns ± 1%     120ns ± 1%  -36.39%  (p=0.000 n=9+10)
NopLoggerContextual-8        379ns ± 1%     243ns ± 0%  -35.77%  (p=0.000 n=9+10)
ValueBindingTimestamp-8      577ns ± 1%     499ns ± 1%  -13.51%  (p=0.000 n=10+10)
ValueBindingCaller-8         898ns ± 2%     844ns ± 2%   -6.00%  (p=0.000 n=10+10)

name                      old alloc/op   new alloc/op   delta
JSONLoggerSimple-8            904B ± 0%      872B ± 0%   -3.54%  (p=0.000 n=10+10)
JSONLoggerContextual-8      1.20kB ± 0%    1.14kB ± 0%   -5.33%  (p=0.000 n=10+10)
Discard-8                    64.0B ± 0%     32.0B ± 0%  -50.00%  (p=0.000 n=10+10)
OneWith-8                    96.0B ± 0%     64.0B ± 0%  -33.33%  (p=0.000 n=10+10)
TwoWith-8                     160B ± 0%      128B ± 0%  -20.00%  (p=0.000 n=10+10)
TenWith-8                     672B ± 0%      640B ± 0%   -4.76%  (p=0.000 n=10+10)
LogfmtLoggerSimple-8          128B ± 0%       96B ± 0%  -25.00%  (p=0.000 n=10+10)
LogfmtLoggerContextual-8      304B ± 0%      240B ± 0%  -21.05%  (p=0.000 n=10+10)
NopLoggerSimple-8             128B ± 0%       96B ± 0%  -25.00%  (p=0.000 n=10+10)
NopLoggerContextual-8         304B ± 0%      240B ± 0%  -21.05%  (p=0.000 n=10+10)
ValueBindingTimestamp-8       159B ± 0%      127B ± 0%  -20.13%  (p=0.000 n=10+10)
ValueBindingCaller-8          112B ± 0%       80B ± 0%  -28.57%  (p=0.000 n=10+10)

name                      old allocs/op  new allocs/op  delta
JSONLoggerSimple-8            19.0 ± 0%      17.0 ± 0%  -10.53%  (p=0.000 n=10+10)
JSONLoggerContextual-8        25.0 ± 0%      21.0 ± 0%  -16.00%  (p=0.000 n=10+10)
Discard-8                     3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
OneWith-8                     3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
TwoWith-8                     3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
TenWith-8                     3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
LogfmtLoggerSimple-8          4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.000 n=10+10)
LogfmtLoggerContextual-8      7.00 ± 0%      3.00 ± 0%  -57.14%  (p=0.000 n=10+10)
NopLoggerSimple-8             4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.000 n=10+10)
NopLoggerContextual-8         7.00 ± 0%      3.00 ± 0%  -57.14%  (p=0.000 n=10+10)
ValueBindingTimestamp-8       5.00 ± 0%      3.00 ± 0%  -40.00%  (p=0.000 n=10+10)
ValueBindingCaller-8          4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.000 n=10+10)

fmt

name                             old time/op    new time/op    delta
SprintfPadding-8                   88.9ns ± 3%    79.1ns ± 1%   -11.09%  (p=0.000 n=10+7)
SprintfEmpty-8                     12.6ns ± 3%    12.8ns ± 3%      ~     (p=0.136 n=10+10)
SprintfString-8                    38.7ns ± 5%    26.9ns ± 6%   -30.65%  (p=0.000 n=10+10)
SprintfTruncateString-8            56.7ns ± 2%    47.0ns ± 3%   -17.05%  (p=0.000 n=10+10)
SprintfQuoteString-8                164ns ± 2%     153ns ± 2%    -7.01%  (p=0.000 n=10+10)
SprintfInt-8                       38.9ns ±15%    26.5ns ± 2%   -31.93%  (p=0.000 n=10+9)
SprintfIntInt-8                    60.3ns ± 9%    38.2ns ± 1%   -36.67%  (p=0.000 n=10+8)
SprintfPrefixedInt-8               58.6ns ±13%    51.2ns ±11%   -12.66%  (p=0.001 n=10+10)
SprintfFloat-8                     71.4ns ± 3%    64.2ns ± 3%   -10.08%  (p=0.000 n=8+10)
SprintfComplex-8                    175ns ± 3%     159ns ± 2%    -9.03%  (p=0.000 n=10+10)
SprintfBoolean-8                   33.5ns ± 4%    25.7ns ± 5%   -23.28%  (p=0.000 n=10+10)
SprintfHexString-8                 65.3ns ± 3%    51.7ns ± 5%   -20.86%  (p=0.000 n=10+9)
SprintfHexBytes-8                  67.2ns ± 5%    67.9ns ± 4%      ~     (p=0.383 n=10+10)
SprintfBytes-8                      129ns ± 7%     124ns ± 7%      ~     (p=0.074 n=9+10)
SprintfStringer-8                   127ns ± 4%     126ns ± 8%      ~     (p=0.506 n=9+10)
SprintfStructure-8                  357ns ± 3%     359ns ± 3%      ~     (p=0.469 n=10+10)
ManyArgs-8                          203ns ± 6%     126ns ± 3%   -37.94%  (p=0.000 n=10+10)
FprintInt-8                         119ns ±10%      74ns ± 3%   -37.54%  (p=0.000 n=10+10)
FprintfBytes-8                      122ns ± 4%     120ns ± 3%      ~     (p=0.124 n=10+10)
FprintIntNoAlloc-8                 78.2ns ± 5%    74.1ns ± 3%    -5.28%  (p=0.000 n=10+10)
ScanInts-8                          349µs ± 1%     349µs ± 0%      ~     (p=0.606 n=9+8)
ScanRecursiveInt-8                 43.8ms ± 7%    40.1ms ± 2%    -8.42%  (p=0.000 n=10+10)
ScanRecursiveIntReaderWrapper-8    43.5ms ± 4%    40.4ms ± 2%    -7.16%  (p=0.000 n=10+9)

name                             old alloc/op   new alloc/op   delta
SprintfPadding-8                    24.0B ± 0%     16.0B ± 0%   -33.33%  (p=0.000 n=10+10)
SprintfEmpty-8                      0.00B          0.00B           ~     (all equal)
SprintfString-8                     21.0B ± 0%      5.0B ± 0%   -76.19%  (p=0.000 n=10+10)
SprintfTruncateString-8             32.0B ± 0%     16.0B ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfQuoteString-8                48.0B ± 0%     32.0B ± 0%   -33.33%  (p=0.000 n=10+10)
SprintfInt-8                        16.0B ± 0%      1.0B ± 0%   -93.75%  (p=0.000 n=10+10)
SprintfIntInt-8                     24.0B ± 0%      3.0B ± 0%   -87.50%  (p=0.000 n=10+10)
SprintfPrefixedInt-8                72.0B ± 0%     64.0B ± 0%   -11.11%  (p=0.000 n=10+10)
SprintfFloat-8                      16.0B ± 0%      8.0B ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfComplex-8                    48.0B ± 0%     32.0B ± 0%   -33.33%  (p=0.000 n=10+10)
SprintfBoolean-8                    8.00B ± 0%     4.00B ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfHexString-8                  96.0B ± 0%     80.0B ± 0%   -16.67%  (p=0.000 n=10+10)
SprintfHexBytes-8                    112B ± 0%      112B ± 0%      ~     (all equal)
SprintfBytes-8                      96.0B ± 0%     96.0B ± 0%      ~     (all equal)
SprintfStringer-8                   32.0B ± 0%     32.0B ± 0%      ~     (all equal)
SprintfStructure-8                   256B ± 0%      256B ± 0%      ~     (all equal)
ManyArgs-8                          80.0B ± 0%      0.0B       -100.00%  (p=0.000 n=10+10)
FprintInt-8                         8.00B ± 0%     0.00B       -100.00%  (p=0.000 n=10+10)
FprintfBytes-8                      32.0B ± 0%     32.0B ± 0%      ~     (all equal)
FprintIntNoAlloc-8                  0.00B          0.00B           ~     (all equal)
ScanInts-8                         15.2kB ± 0%    15.2kB ± 0%      ~     (p=0.248 n=9+10)
ScanRecursiveInt-8                 21.6kB ± 0%    21.6kB ± 0%      ~     (all equal)
ScanRecursiveIntReaderWrapper-8    21.7kB ± 0%    21.7kB ± 0%      ~     (all equal)

name                             old allocs/op  new allocs/op  delta
SprintfPadding-8                     2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfEmpty-8                       0.00           0.00           ~     (all equal)
SprintfString-8                      2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfTruncateString-8              2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfQuoteString-8                 2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfInt-8                         2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfIntInt-8                      3.00 ± 0%      1.00 ± 0%   -66.67%  (p=0.000 n=10+10)
SprintfPrefixedInt-8                 2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfFloat-8                       2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfComplex-8                     2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfBoolean-8                     2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfHexString-8                   2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
SprintfHexBytes-8                    2.00 ± 0%      2.00 ± 0%      ~     (all equal)
SprintfBytes-8                       2.00 ± 0%      2.00 ± 0%      ~     (all equal)
SprintfStringer-8                    4.00 ± 0%      4.00 ± 0%      ~     (all equal)
SprintfStructure-8                   7.00 ± 0%      7.00 ± 0%      ~     (all equal)
ManyArgs-8                           8.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
FprintInt-8                          1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
FprintfBytes-8                       1.00 ± 0%      1.00 ± 0%      ~     (all equal)
FprintIntNoAlloc-8                   0.00           0.00           ~     (all equal)
ScanInts-8                          1.60k ± 0%     1.60k ± 0%      ~     (all equal)
ScanRecursiveInt-8                  1.71k ± 0%     1.71k ± 0%      ~     (all equal)
ScanRecursiveIntReaderWrapper-8     1.71k ± 0%     1.71k ± 0%      ~     (all equal)

Change-Id: I7ba72a25fea4140a0ba40a9f443103ed87cc69b5
Reviewed-on: https://go-review.googlesource.com/35554
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

This ensures there isn't a live reference to buf1 on our stack
when MultiReader is inlined.

Fixes #18819.

Change-Id: I96a8cdc1ffad8f8a10c0ddcbf0299005f3176b61
Reviewed-on: https://go-review.googlesource.com/35931
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Instead of always appending to c.Values,
choose whichever slice is larger;
b.Values will be set to nil anyway.

Appending once instead of in a loop also
limits slice growth to once per function call
and is more efficient.

Reduces max rss for the program in #18602 by 6.5%,
and eliminates fuseBlockPlain from the alloc_space
pprof output. fuseBlockPlain previously accounted
for 16.74% of allocated memory.

Updates #18602.

Change-Id: I417b03722d011a59a679157da43dc91f4425210e
Reviewed-on: https://go-review.googlesource.com/35114
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Remove rotate generation from walk.  Remove OLROT and ssa.Lrot* opcodes.
Generate rotates during SSA lowering for architectures that have them.

This CL will allow rotates to be generated in more situations,
like when the shift values are determined to be constant
only after some analysis.

Fixes #18254

Change-Id: I8d6d684ff5ce2511aceaddfda98b908007851079
Reviewed-on: https://go-review.googlesource.com/34232
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Intrinsics are ok to inline as they don't rewrite to actual calls.

Change-Id: Ieb19c834c61579823c62c6d1a1b425d6c4d4de23
Reviewed-on: https://go-review.googlesource.com/34272
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>