Results are a bit noisy, but show good improvement (haswell)

name            old time/op    new time/op     delta
Memclr5-48        6.06ns ± 8%     5.65ns ± 8%    -6.81%  (p=0.000 n=20+20)
Memclr16-48       5.75ns ± 6%     5.71ns ± 6%      ~     (p=0.545 n=20+19)
Memclr64-48       6.54ns ± 5%     6.14ns ± 9%    -6.12%  (p=0.000 n=18+20)
Memclr256-48      10.1ns ±12%      9.9ns ±14%      ~     (p=0.285 n=20+19)
Memclr4096-48      104ns ± 8%       57ns ±15%   -44.98%  (p=0.000 n=20+20)
Memclr65536-48    2.45µs ± 5%     2.43µs ± 8%      ~     (p=0.665 n=16+20)
Memclr1M-48       58.7µs ±13%     56.4µs ±11%    -3.92%  (p=0.033 n=20+19)
Memclr4M-48        233µs ± 9%      234µs ± 9%      ~     (p=0.728 n=20+19)
Memclr8M-48        469µs ±11%      472µs ±16%      ~     (p=0.947 n=20+20)
Memclr16M-48       947µs ±10%      916µs ±10%      ~     (p=0.050 n=20+19)
Memclr64M-48      10.9ms ±10%      4.5ms ± 9%   -58.43%  (p=0.000 n=20+20)
GoMemclr5-48      3.80ns ±13%     3.38ns ± 6%   -11.02%  (p=0.000 n=20+20)
GoMemclr16-48     3.34ns ±15%     3.40ns ± 9%      ~     (p=0.351 n=20+20)
GoMemclr64-48     4.10ns ±15%     4.04ns ±10%      ~     (p=1.000 n=20+19)
GoMemclr256-48    7.75ns ±20%     7.88ns ± 9%      ~     (p=0.227 n=20+19)

name            old speed      new speed       delta
Memclr5-48       826MB/s ± 7%    886MB/s ± 8%    +7.32%  (p=0.000 n=20+20)
Memclr16-48     2.78GB/s ± 5%   2.81GB/s ± 6%      ~     (p=0.550 n=20+19)
Memclr64-48     9.79GB/s ± 5%  10.44GB/s ±10%    +6.64%  (p=0.000 n=18+20)
Memclr256-48    25.4GB/s ±14%   25.6GB/s ±12%      ~     (p=0.647 n=20+19)
Memclr4096-48   39.4GB/s ± 8%   72.0GB/s ±13%   +82.81%  (p=0.000 n=20+20)
Memclr65536-48  26.6GB/s ± 6%   27.0GB/s ± 9%      ~     (p=0.517 n=17+20)
Memclr1M-48     17.9GB/s ±12%   18.5GB/s ±11%      ~     (p=0.068 n=20+20)
Memclr4M-48     18.0GB/s ± 9%   17.8GB/s ±14%      ~     (p=0.547 n=20+20)
Memclr8M-48     17.9GB/s ±10%   17.8GB/s ±14%      ~     (p=0.947 n=20+20)
Memclr16M-48    17.8GB/s ± 9%   18.4GB/s ± 9%      ~     (p=0.050 n=20+19)
Memclr64M-48    6.19GB/s ±10%  14.87GB/s ± 9%  +140.11%  (p=0.000 n=20+20)
GoMemclr5-48    1.31GB/s ±10%   1.48GB/s ± 6%   +13.06%  (p=0.000 n=19+20)
GoMemclr16-48   4.81GB/s ±14%   4.71GB/s ± 8%      ~     (p=0.341 n=20+20)
GoMemclr64-48   15.7GB/s ±13%   15.8GB/s ±11%      ~     (p=0.967 n=20+19)

Change-Id: I393f3f20e2f31538d1b1dd70d6e5c201c106a095
Reviewed-on: https://go-review.googlesource.com/16773
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Klaus Post <klauspost@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>

Fixes #11959
Fixes #12035

Skip the CallbackGC test on linux/arm. This test takes between 30 and 60
seconds to run by itself, and is run 4 times over the course of ./run.bash
(once during the runtime test, three times more later in the build).

Change-Id: I4e7d3046031cd8c08f39634bdd91da6e00054caf
Reviewed-on: https://go-review.googlesource.com/14485Reviewed-by: Russ Cox <rsc@golang.org>

Original code is mistakenly panics on VirtualAlloc failure - we want
it to go looking for smaller memory region that VirtualAlloc will
succeed to allocate. Also return immediately if VirtualAlloc succeeds.
See rsc comment on issue #12587 for details.

I still don't have a test for this. So I can only hope that this

Fixes #12587

Change-Id: I052068ec627fdcb466c94ae997ad112016f734b7
Reviewed-on: https://go-review.googlesource.com/17169Reviewed-by: Russ Cox <rsc@golang.org>

See https://go-review.googlesource.com/#/c/17047/ for the bug fix.

Change-Id: Id5b0a37439d0f8f1e668f7c2ac84335b37f3a300
Reviewed-on: https://go-review.googlesource.com/17177Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #13073

Change-Id: I4fd9c6c61f1b9d49f66816839ca35209b4147ae3
Reviewed-on: https://go-review.googlesource.com/17167Reviewed-by: Russ Cox <rsc@golang.org>

Get rid of residue after removing old parser.

Change-Id: I0dace1037d50959071a082c276f9f374eef6edb2
Reviewed-on: https://go-review.googlesource.com/17179
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

It relates to an obsolete notion of 'skipped-but-okay' tests.

Fixes #12394

Change-Id: Ib7e6444dc8565e1390bd42d65d30fac136593f78
Reviewed-on: https://go-review.googlesource.com/17000
Run-TryBot: Caleb Spare <cespare@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <shurcool@gmail.com>

These are methods that are "obviously" going to get inlined -- until you build
with -l, when they can trigger a stack split at a bad time.

Fixes #11482

Change-Id: Ia065c385978a2e7fe9f587811991d088c4d68325
Reviewed-on: https://go-review.googlesource.com/17165
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Commit bbd1a1c7 prevented SIGPROF from scanning stacks that were being
copied, but it didn't prevent a stack copy (specifically a stack
shrink) from happening while SIGPROF is scanning the stack. As a
result, a stack copy may adjust stack barriers while SIGPROF is in the
middle of scanning a stack, causing SIGPROF to panic when it detects
an inconsistent stack barrier.

Fix this by taking the stack barrier lock while adjusting the stack.
In addition to preventing SIGPROF from scanning this stack, this will
block until any in-progress SIGPROF is done scanning the stack.

For 1.5.2.

Fixes #13362.
Updates #12932.

Change-Id: I422219c363054410dfa56381f7b917e04690e5dd
Reviewed-on: https://go-review.googlesource.com/17191
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Calling timeBeginPeriod changes Windows global timer resolution
from 15ms to 1ms. This used to improve Go runtime scheduler
performance, but not anymore. Thanks to @aclements, scheduler now
behaves the same way if we call timeBeginPeriod or not.

Remove call to timeBeginPeriod, since it is machine global
resource, and there are downsides of using low timer resolution.
See issue #8687 for details.

Fixes #8687

Change-Id: Ib7e41aa4a81861b62a900e0e62776c9ef19bfb73
Reviewed-on: https://go-review.googlesource.com/17164Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Yasuhiro MATSUMOTO <mattn.jp@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>

- moved yySymType and token constants (L...) to lex.go
- removed oldparser flag and related code
- removed go generate that generated y.go

Fixes #13240.

Change-Id: I2576ec61ee1efe482f2a5132175725c9c02ef977
Reviewed-on: https://go-review.googlesource.com/17176Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This relocation is found in libgcc.a in the .eh_frame, and therefore
needs to be handled when doing an internal link.

Fixes #13375.

Change-Id: Idd9e8178e08851a101b43261a30939bcfaf394f9
Reviewed-on: https://go-review.googlesource.com/17173
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>

It is not important to add, since it's only used for creating an error message,
but for consistency in the API between text/template and html/template
it should be provided here.

The implementation just calls the one in text/template.

Fixes #13349.

Change-Id: I0882849e06a58f1e38b00eb89d79ac39777309b2
Reviewed-on: https://go-review.googlesource.com/17172Reviewed-by: Andrew Gerrand <adg@golang.org>

Introduce a try_ntype function which doesn't return an error upon
not finding a type. Use it instead of having separate repeated
token checks. Simpler, less code, and more efficient.

Change-Id: I81e482158b71901eb179470269349688636aa0ba
Reviewed-on: https://go-review.googlesource.com/17157Reviewed-by: Chris Manghane <cmang@golang.org>

Change-Id: Icdce5cdb8676c3bcb73bd943b406000252509521
Reviewed-on: https://go-review.googlesource.com/17174Reviewed-by: Rob Pike <r@golang.org>

Sscanf doc says:
Newlines in the input must match newlines in the format.

However Sscanf didn't check newline in the end of input (EOF).
A test for the case is broken.

* check newline in EOF
* fix the test
* slightly simplify ss.doScanf

Fixes #12788

Change-Id: Iaf6b7d81324a72e557543ac22ecea5cecb72e0d6
Reviewed-on: https://go-review.googlesource.com/16165
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

This improves the documentation comment on gcMarkDone, replaces a
recursive call with a simple goto, and disables preemption before
stopping the world in accordance with the documentation comment on
stopTheWorldWithSema.

Updates #13363, but, sadly, doesn't fix it.

Change-Id: I6cb2a5836b35685bf82f7b1ce7e48a7625906656
Reviewed-on: https://go-review.googlesource.com/17149Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This improves stack barrier debugging messages in various ways:

1) Rather than printing only the remaining stack barriers (of which
   there may be none, which isn't very useful), print all of the G's
   stack barriers with a marker at the position the stack itself has
   unwound to and a marker at the problematic stack barrier (where
   applicable).

2) Rather than crashing if we encounter a stack barrier when there are
   no more stkbar entries, print the same debug message we would if we
   had encountered a stack barrier at an unexpected location.

Hopefully this will help with debugging #12528.

Change-Id: I2e6fe6a778e0d36dd8ef30afd4c33d5d94731262
Reviewed-on: https://go-review.googlesource.com/17147Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

The stack barrier locking functions use a simple cas lock because they
need to support trylock, but currently don't increment g.m.locks. This
is okay right now because they always run on the system stack or the
signal stack and are hence non-preemtible, but this could lead to
difficult-to-reproduce deadlocks if these conditions change in the
future.

Make these functions more robust by incrementing g.m.locks and making
them nosplit to enforce non-preemtibility.

Change-Id: I73d60a35bd2ad2d81c73aeb20dbd37665730eb1b
Reviewed-on: https://go-review.googlesource.com/17058
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ingo Oeser <nightlyone@googlemail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #13344.

Change-Id: I33c6721fd33d144c85c87840ddf27ce15aa72328
Reviewed-on: https://go-review.googlesource.com/17151
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

It started failing on the dragonfly builder at an unrelated commit
(one that changed the wording in a few comments in the compiler).

Created #13364 to track this.

Change-Id: I462880bed8ff565a9950e7e185de97d43999c5e2
Reviewed-on: https://go-review.googlesource.com/17143Reviewed-by: Russ Cox <rsc@golang.org>

This appears to be an unintended omission. The check func is declared
just above, and the err value from template.Parse is captured rather
than discarded via blank identifier. All following calls that similarly
return err are checked, so it can't be that this example elides error
checking for brevity. Finally, if you look at Example_autoescaping,
it does check err from template.Parse and its code is very similar.

Change-Id: I076e1846302d5f2cdb1d027ed85ca0db85e33ace
Reviewed-on: https://go-review.googlesource.com/17170Reviewed-by: Andrew Gerrand <adg@golang.org>

Found by cmd/vet

Change-Id: I29dd207ecd40fe703054e8ad4e81b3267ca89da2
Reviewed-on: https://go-review.googlesource.com/17160Reviewed-by: David Crawshaw <crawshaw@golang.org>

- fix/check location of popdcl calls where questioned
- remove unnecessary handling of ... (LDDD) in ntype (couldn't be reached)
- inlined and fnret_type and simplified fnres as a consequence
- leave handling of ... (LDDD) in arg_list alone (remove TODO)
- verify that parser requires a ';' after last statement in a case/default
  (added test case)

Fixes #13243.

Change-Id: Iad94b498591a5e85f4cb15bbc01e8e101415560d
Reviewed-on: https://go-review.googlesource.com/17155
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Chris Manghane <cmang@golang.org>

Change-Id: I7c084542996226f3ed464314a5622fcfaac02d61
Reviewed-on: https://go-review.googlesource.com/17103Reviewed-by: Chris Manghane <cmang@golang.org>

No code changes.

Change-Id: Ibbba7c86007d74b853fb59aa742f87783bd69503
Reviewed-on: https://go-review.googlesource.com/16541Reviewed-by: Ian Lance Taylor <iant@golang.org>

The gccgo bug report https://gcc.gnu.org/PR65785 points out that the
multicast listen tests will use the network even with -test.short.
Fix test by checking testing.Short with a nil interface.

Change-Id: I7eab8df34fe3b78fc376912312fac9d0f94977f1
Reviewed-on: https://go-review.googlesource.com/17154Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Previously it said, "bad verb %% for ...", which is not only wrong,
it's ironic as the fix is to use %% rather than % at the end of the
string. Diagnose the case where a simple % is at EOF.

If there's anything after the percent, the error is already good
but this CL also puts quotes around the verb designation ('%d' etc.)
to make it even clearer, especially when there is a space involved.

Fixes #12315.

Change-Id: I31d30659965e940d0bd9ce92a475aab3e2369ef0
Reviewed-on: https://go-review.googlesource.com/17150Reviewed-by: Ian Lance Taylor <iant@golang.org>

For #13243.

Change-Id: I214945278255a49f93120f9407f536a6c01a29fb
Reviewed-on: https://go-review.googlesource.com/17101Reviewed-by: Chris Manghane <cmang@golang.org>

Use a combination of follow- and stop-token lists and nesting levels
to better synchronize parser after a syntax error.

Fixes #13319.

Change-Id: I9592e0b5b3ba782fb9f9315fea16163328e204f7
Reviewed-on: https://go-review.googlesource.com/17080Reviewed-by: Chris Manghane <cmang@golang.org>

Change-Id: I22a8a233bc157fa09cd0283fcd4bc14d90faed70
Reviewed-on: https://go-review.googlesource.com/17066Reviewed-by: Chris Manghane <cmang@golang.org>

Minor internal optimization.

Change-Id: I229d4a9df3da542b77f830c2830f63ec23ec1d61
Reviewed-on: https://go-review.googlesource.com/17065Reviewed-by: Chris Manghane <cmang@golang.org>

This never happens but for pathological input where a BOM sequence
is unfinished and ends in EOF (src: "package p\n\nfunc \xef\xef").
No test case added because the /test framework doesn't lend itself
easily to it in this case (file must end in EOF rather than comment).
Instead, tested manually.

Fixes #13268.

Change-Id: I049034e6dde7ad884b0a8c329921adac1866ff18
Reviewed-on: https://go-review.googlesource.com/17047Reviewed-by: Chris Manghane <cmang@golang.org>

Change-Id: If22b8f358e78deca31bd0b1a25e7966987853405
Reviewed-on: https://go-review.googlesource.com/17083Reviewed-by: Rob Pike <r@golang.org>

This test depends on GODEBUG=gcstackbarrierall, which doesn't work on
ppc64.

Updates #13334.

Change-Id: Ie554117b783c4e999387f97dd660484488499d85
Reviewed-on: https://go-review.googlesource.com/17120
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

During a crash showing goroutine stacks of all threads
(with GOTRACEBACK=crash), it can be that f == nil.

Only happens on Solaris; not sure why.

Change-Id: Iee2c394a0cf19fa0a24f6befbc70776b9e42d25a
Reviewed-on: https://go-review.googlesource.com/17110Reviewed-by: Austin Clements <austin@google.com>

(TestStackBarrierProfiling is failing on darwin/arm.)

Change-Id: I8006d6222ccafc213821e02105896440079caa37
Reviewed-on: https://go-review.googlesource.com/17091Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Some Android OS installations have very strange permissions on their
/system/etc directory, meaning that Readdir fails. Instead use
/system/framework, which is far more regular.

Change-Id: Iefc140614183cda0f875e0f6ef859f4d4eaad9da
Reviewed-on: https://go-review.googlesource.com/17078Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Update golang/go#9327.

Change-Id: Iab7dad31cf6b9f9347c3f34faebb67ecb38b17fc
Reviewed-on: https://go-review.googlesource.com/16701
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

Change-Id: Ife9e019063473bb0a976cfef4b6e78d951fcb09e
Reviewed-on: https://go-review.googlesource.com/17081
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>