I was surprised to see readvarint show up in a cpu profile.

Use a few simple optimizations to speed up stack copying:

* Avoid making a copy of the cache.entries array or any of its elements.
* Use a shift instead of a signed division in stackmapdata.
* Change readvarint to return the number of bytes consumed
  rather than an updated slice.
* Make some minor optimizations to readvarint to help the compiler.
* Avoid called readvarint when the value fits in a single byte.

The first and last optimizations are the most significant,
although they all contribute a little.

Add a benchmark for stack copying that includes lots of different
functions in a recursive loop, to bust the cache.

This might speed up other runtime operations as well;
I only benchmarked stack copying.

name                old time/op  new time/op  delta
StackCopy-8         96.4ms ± 2%  82.7ms ± 1%  -14.24%  (p=0.000 n=20+19)
StackCopyNoCache-8   167ms ± 1%   131ms ± 1%  -21.58%  (p=0.000 n=20+20)

Change-Id: I13d5c455c65073c73b656acad86cf8e8e3c9807b
Reviewed-on: https://go-review.googlesource.com/43150
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

The path package has a reference to the path/filepath package, so add
a reverse reference.

And clarify the path package doesn't do Windows paths.

Fixes #20117

Change-Id: I65c5ce24e600b32ea20c5821b744bd89f6aff98c
Reviewed-on: https://go-review.googlesource.com/45653Reviewed-by: Jaana Burcu Dogan <jbd@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

There are currently two arrays indexed by P ID: allp and pdesc.
Consolidate these by moving the pdesc fields into type p so they can
be indexed off allp along with all other per-P state.

For #15131.

Change-Id: Ib6c4e6e7612281a1171ba4a0d62e52fd59e960b4
Reviewed-on: https://go-review.googlesource.com/45572
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

Current CommentedNode cannot handle associated comments which satisfy
    node.End() < comment.Pos()

This CL solves it.

Fixes #20635

Change-Id: I58e2e3703999bb38a6ce37112e986c4b1b2eace0
Reviewed-on: https://go-review.googlesource.com/45292
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Updates #20266.
Fixes #20664.

Change-Id: Ifca30409fc7971497efb6d84f3f98760157c2233
Reviewed-on: https://go-review.googlesource.com/45650Reviewed-by: Austin Clements <austin@google.com>

Currently MaxGomaxprocs is 256. The previous CL saved enough per-P
static space that we can quadruple MaxGomaxprocs (and hence the static
size of allp) and still come out ahead.

This is safe for Go 1.9. In Go 1.10 we'll eliminate the hard-coded
limit entirely.

Updates #15131.

Change-Id: I919ea821c1ce64c27812541dccd7cd7db4122d16
Reviewed-on: https://go-review.googlesource.com/45673
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

According to the language spec, a struct field name should
be an identifier.

  identifier = letter { letter | unicode_digit } .
  letter = unicode_letter | "_" .

Implements a function 'isValidFieldName(fieldName string) bool'.
To check if the field name is a valid identifier or not.
It will panic if the field name is invalid.

It uses the non-exported function implementation 'isLetter'
from the package 'scanner', used to parse an identifier.

Fixes #20600.

Change-Id: I1db7db1ad88cab5dbea6565be15cc7461cc56c44
Reviewed-on: https://go-review.googlesource.com/45590Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

I accidentally set the wrong pattern mask as
* []byte("\x4F\x67\x67\x53\x00") --> "OggS", the byte pattern itself.
instead of
* []byte("\xFF\xFF\xFF\xFF\xFF")
which was a copy-paste error.

The correct pattern is described at
https://mimesniff.spec.whatwg.org/#matching-an-audio-or-video-type-pattern
which I was using as a reference but I mistyped.

Fixes #20513

Change-Id: Ie9cb60ac7edbf03075070878775b964116ce92d0
Reviewed-on: https://go-review.googlesource.com/44336
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

Change-Id: I9b0f17e123805ad9f526f5ea44b23cf4dbadcdcc
Reviewed-on: https://go-review.googlesource.com/45611Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The compiler now also prints column information - make sure we use
the correct regexp for compiler error cleanups. Accept both, error
positions with columns and without, since column printing may be
disabled with -gcflags=-C.

Fixes #20628.

Change-Id: I46dc921dd5c29d7b8172cd19a3df57951f60d889
Reviewed-on: https://go-review.googlesource.com/45612
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: Ib6e2b858fcb15ea95fa8cfcba3bfac4e210605fe
Reviewed-on: https://go-review.googlesource.com/45610Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Ensure a Stmt prepared on a Conn executes on the same driver.Conn.
This also removes another instance of duplicated prepare logic
as a side effect.

Fixes #20647

Change-Id: Ia00a19e4dd15e19e4d754105babdff5dc127728f
Reviewed-on: https://go-review.googlesource.com/45391Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Back in the day, allp was just a pointer to an array. As a result, the
runtime has a few loops of the form:

    for i := 0; ; i++ {
        p := allp[i]
	if p == nil {
	    break
	}
	...
    }

This is silly now because it requires that allp be one longer than the
maximum possible number of Ps, but now that allp is in Go it has a
length.

Replace these with range loops.

Change-Id: I91ef4bc7bd3c9d4fda2264f4aa1b1d0271d7f578
Reviewed-on: https://go-review.googlesource.com/45571
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #20266.

Change-Id: I51383820880e3d3566ef3d70650a0863756003ba
Reviewed-on: https://go-review.googlesource.com/44291
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I4c2c82cb0354f843a3283a650ed2cd2b6aef5895
Reviewed-on: https://go-review.googlesource.com/36900Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #20587

Change-Id: I160da21ecdee07c6370be8c46cbd04d4fbb07abb
Reviewed-on: https://go-review.googlesource.com/45550Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Otherwise the packages will not pick up the way that -installsuffix is
changed by -buildmode and -race.

Fixes #20512.

Change-Id: Ieca32c958a531beb6331dff30d7e9a4998867dbb
Reviewed-on: https://go-review.googlesource.com/44630
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

"MOVW FPSR, g" should be assembled to 0xeef1aa10, but actually
0xee30a110 (RFS). "MOVW g, FPSR" should be 0xeee1aa10, but actually
0xee20a110 (WFS). They should be updated to VFP forms, since the ARM
back end doesn't support non-VFP floating points.

The patch fixes them and adds more assembly encoding tests.

fixes #20643

Change-Id: I3b29490337c6e8d891b400fcedc8b0a87b82b527
Reviewed-on: https://go-review.googlesource.com/45276
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Last time zoneinfo_abbrs_windows.go was updated in CL 27832.
Time for another update.

Change-Id: I8dc3a1de6f22e90e634b2176188f257a260b6463
Reviewed-on: https://go-review.googlesource.com/45450Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Per golang.org/s/generatedcode

Updates #nnn

Change-Id: Ia7513ef6bd26c20b62b57b29f7770684a315d389
Reviewed-on: https://go-review.googlesource.com/45470
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Rather then write to the same variable per fakeConn, write to either
fakeConn or rowsCursor.

Fixes #20646

Change-Id: Ifc79f989bd1606b8e3ebecb1e7844cce3ad06e17
Reviewed-on: https://go-review.googlesource.com/45393Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ib59e1eea64b0bd2cf8ed778607aafcf74a6239a3
Reviewed-on: https://go-review.googlesource.com/45087Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes golang/go#20163

Change-Id: I0caf95fc84aa502715848151c93b6e7bee003ea5
Reviewed-on: https://go-review.googlesource.com/44890Reviewed-by: Daniel Theophanes <kardianos@gmail.com>

Fixes #20636

Change-Id: Icea0012fecb73944c95f6037922505c63b57b245
Reviewed-on: https://go-review.googlesource.com/45295Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

In addition to adding a guard to the Rows close, add a var
in the fakeConn that gets read and written to on each
operation, simulating writing or reading from the server.

TestConcurrency/TxStmt* tests have been commented out
as they now fail after checking for races on the fakeConn.
See issue #20646 for more information.

Fixes #20622

Change-Id: I80b36ea33d776e5b4968be1683ff8c61728ee1ea
Reviewed-on: https://go-review.googlesource.com/45275
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This reverts commit ef0f7fb9.

Reason for revert: Altered behavior of Queries prior to Tx commit. See #20631.

Change-Id: I2548507c2935a7c60b92aae377dcc8e9aca66331
Reviewed-on: https://go-review.googlesource.com/45231
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Bulat Gaifullin <gaifullinbf@gmail.com>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #20587

Change-Id: If1f17a110ef3cc367849bd01e2733c60d85f124b
Reviewed-on: https://go-review.googlesource.com/45118Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It listens on all addresses, which users might not want.

Updates #18806 (follow-up to feedback from CL 45088)

Change-Id: I51de2d3fc3cd88a61eb3c63018c47aea920c0549
Reviewed-on: https://go-review.googlesource.com/45157
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

ARM currently does not use a hardware yield instruction in the spin
loop in procyield because the YIELD instruction was only added in
ARMv6K. However, it appears earlier ARM chips will interpret the YIELD
encoding as an effective NOP (specifically an MSR instruction that
ultimately has no effect on the CPSR register).

Hence, use YIELD in procyield on ARM since it should be, at worst,
harmless.

Fixes #16663.

Change-Id: Id1787ac48862b785b92c28f1ac84cb4908d2173d
Reviewed-on: https://go-review.googlesource.com/45250
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Done with grep & interactive search & replace, to double-check
replacements. Not many remained after CL 20022.

Fixes #18572

Change-Id: Idbe90ba3b584f9b9661d2bbd141607daaadfa41a
Reviewed-on: https://go-review.googlesource.com/45270Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

Nobody uses 10.6 these days anyway.

Fixes #20623

Change-Id: I698c83cbc288082558e34097ff54d1428aed75ec
Reviewed-on: https://go-review.googlesource.com/45171Reviewed-by: Matt Layher <mdlayher@gmail.com>

If we're in a situation where printing the fp and sp in the traceback
is useful, it's almost certainly also useful to print the PC.

Change-Id: Ie48a0d5de8a54b5b90ab1d18638a897958e48f70
Reviewed-on: https://go-review.googlesource.com/45210
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Updates #20587

Change-Id: I551a21c0226bc66fd7bca737c30cba679b958c37
Reviewed-on: https://go-review.googlesource.com/45091Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This results in names to unexported fields like
net.(*Dialer)."".deadline instead of net.(*Dialer).deadline.

Fixes #18419.

Change-Id: I0415c68b77cc16125c2401320f56308060ac3f25
Reviewed-on: https://go-review.googlesource.com/44070
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

The golang.org/x/tools/cmd/bundle tool previously had a bug where it
dropped some comments.

This regenerates it with the fixed version (https://golang.org/cl/45117).

(Upstream is still git rev 3470a06c1, from https://golang.org/cl/44331)

Updates #20548

Change-Id: Ic5d9208a0c8f7facdb7b315c6acab66ace34c0a9
Reviewed-on: https://go-review.googlesource.com/45158Reviewed-by: Hiroshi Ioka <hirochachacha@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Several of the CLs that were against the runtime are noted in other
places in the release notes, depending on where they are most
user-visible.

Change-Id: I167dc7ff17a4c5f9a5d22d5bd123aa0e99f5639e
Reviewed-on: https://go-review.googlesource.com/45137Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

Change-Id: I361587ba0ddffb5ee4a3d1bdb6219710a30da197
Reviewed-on: https://go-review.googlesource.com/45132Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

"MOVW R1, CPSR" is assembled to 0xe129f001, which should be 0xe12cf001.
"MOVW $255, CPSR" is assembled to 0xe329f0ff, which should be 0xe32cf0ff.

This patch fixes them and adds more assembly encoding tests.

fix #20626

Change-Id: Iefc945879ea774edf40438ce39f52c144e1501a1
Reviewed-on: https://go-review.googlesource.com/45170Reviewed-by: Cherry Zhang <cherryyz@google.com>

Because of parallel tests, which have stalled executions, the RUN
output of a test can be much earlier than its completion output resulting
in hard-to-read verbose output.

The tests are displayed in the order in which the output shows
that they began, to make it easy to line up with the "RUN" output.
Similarly, the definitions of when tests begin and complete is
determined by when RUN and FAIL/SKIP/PASS are output since the
focus of this code is on enhancing readability.

Fixes #19397

Change-Id: I4d0ca3fd268b620484e7a190117f79a33b3dc461
Reviewed-on: https://go-review.googlesource.com/44352
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

No test because as far as I can tell, there aren't existing tests for
these.

Fixes #18383

Change-Id: I06eaef05777a1474886167e3797c5bcd93189d1b
Reviewed-on: https://go-review.googlesource.com/45156
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>