Fixes #17224.

Some systems have more than just "lo" in a fresh network namespace, due
to IPv6. Instead of testing for exactly 3 lines of output (implying 1
interface), just test to make sure that the unshare call resulted in
fewer interfaces than before. This should still verify that unshare did
something.

Change-Id: Iaf84c2b0e673fc207059d62e2f4dd7583a753419
Reviewed-on: https://go-review.googlesource.com/30372Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Jessica Frazelle <me@jessfraz.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change float32/float64 formatting to use non-exponential form
for a slightly wider range, to more closely match ES6 JSON.stringify
and other JSON generators.

Most notably:

	1e20 now formats as 100000000000000000000 (previously 1e+20)
	1e-6 now formats as 0.000001 (previously 1e-06)
	1e-7 now formats as 1e-7 (previously 1e-07)

This also brings the int64 and float64 formatting in line with each other,
for all shared representable values. For example both int64(1234567)
and float64(1234567) now format as "1234567", where before the
float64 formatted as "1.234567e+06".

The only variation now compared to ES6 JSON.stringify is that
Go continues to encode negative zero as "-0", not "0", so that
the value continues to be preserved during JSON round trips.

Fixes #6384.
Fixes #14135.

Change-Id: Ib0e0e009cd9181d75edc0424a28fe776bcc5bbf8
Reviewed-on: https://go-review.googlesource.com/30371Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

These are conditional branches that takes a register instead of
flags as control value.

Reduce binary size by 0.7%, text size by 2.4% (cmd/go as an
exmaple).

Change-Id: I0020cfde745f9eab680b8b949ad28c87fe183afd
Reviewed-on: https://go-review.googlesource.com/30030Reviewed-by: David Chase <drchase@google.com>

In the function prologue, we emit a jump to the beginning of
the function immediately after calling morestack. And in the
runtime stack growing code, it decodes and emulates that jump.
This emulation was necessary before we had per-PC SP deltas,
since the traceback code assumed that the frame size was fixed
for the whole function, except on the first instruction where
it was 0. Since we now have per-PC SP deltas and PCDATA, we
can correctly record that the frame size is 0. This makes the
emulation unnecessary.

This may be helpful for registerized calling convention, where
there may be unspills of arguments after calling morestack. It
also simplifies the runtime.

Change-Id: I7ebee31eaee81795445b33f521ab6a79624c4ceb
Reviewed-on: https://go-review.googlesource.com/30138Reviewed-by: David Chase <drchase@google.com>

Windows doesn't remove an open file.

Fixes #17345

Change-Id: I283930c7d6eb3bc09ad208191afefe989804ce32
Reviewed-on: https://go-review.googlesource.com/30430
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change updates PPC64.rules to recognize constant shift
counts and generate more efficient code sequences in those cases.

Fixes #17336

Change-Id: I8a7b812408d7a68388df41e42bad045dd214be17
Reviewed-on: https://go-review.googlesource.com/30310
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

complex64 and complex128 are treated like [2]float32 and [2]float64,
so it makes sense to align them the same way.

Change-Id: Ic614bcdcc91b080aeb1ad1fed6fc15ba5a2971f8
Reviewed-on: https://go-review.googlesource.com/19800
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

To refine a set of possibly equivalent values, the old CSE algorithm
picked one value, compared it against all the others, and made two sets
out of the results (the values that match the picked value and the
values that didn't).  Unfortunately, this leads to O(n^2) behavior. The
picked value ends up being equal to no other values, we make size 1 and
size n-1 sets, and then recurse on the size n-1 set.

Instead, sort the set by the equivalence classes of its arguments.  Then
we just look for spots in the sorted list where the equivalence classes
of the arguments change.  This lets us do a multi-way split for O(n lg
n) time.

This change makes cmpDepth unnecessary.

The refinement portion used to call the type comparator.  That is
unnecessary as the type was already part of the initial partition.

Lowers time of 16361 from 8 sec to 3 sec.
Lowers time of 15112 from 282 sec to 20 sec. That's kind of unfair, as
CL 30257 changed it from 21 sec to 282 sec. But that CL fixed other bad
compile times (issue #17127) by large factors, so net still a big win.

Fixes #15112
Fixes #16361

Change-Id: I351ce111bae446608968c6d48710eeb6a3d8e527
Reviewed-on: https://go-review.googlesource.com/30354Reviewed-by: Todd Neal <todd@tneal.org>

This commit changes parseRecord to allocate a single string per record,
instead of per field, by using indexes into the raw record.

Benchstat (done with f69991c1)

name                          old time/op    new time/op    delta
Read-8                          3.17µs ± 0%    2.78µs ± 1%  -12.35%  (p=0.016 n=4+5)
ReadWithFieldsPerRecord-8       3.18µs ± 1%    2.79µs ± 1%  -12.23%  (p=0.008 n=5+5)
ReadWithoutFieldsPerRecord-8    4.59µs ± 0%    2.77µs ± 0%  -39.58%  (p=0.016 n=4+5)
ReadLargeFields-8               57.0µs ± 0%    55.7µs ± 0%   -2.18%  (p=0.008 n=5+5)

name                          old alloc/op   new alloc/op   delta
Read-8                            660B ± 0%      664B ± 0%   +0.61%  (p=0.008 n=5+5)
ReadWithFieldsPerRecord-8         660B ± 0%      664B ± 0%   +0.61%  (p=0.008 n=5+5)
ReadWithoutFieldsPerRecord-8    1.14kB ± 0%    0.66kB ± 0%  -41.75%  (p=0.008 n=5+5)
ReadLargeFields-8               3.86kB ± 0%    3.94kB ± 0%   +1.86%  (p=0.008 n=5+5)

name                          old allocs/op  new allocs/op  delta
Read-8                            30.0 ± 0%      18.0 ± 0%  -40.00%  (p=0.008 n=5+5)
ReadWithFieldsPerRecord-8         30.0 ± 0%      18.0 ± 0%  -40.00%  (p=0.008 n=5+5)
ReadWithoutFieldsPerRecord-8      50.0 ± 0%      18.0 ± 0%  -64.00%  (p=0.008 n=5+5)
ReadLargeFields-8                 66.0 ± 0%      24.0 ± 0%  -63.64%  (p=0.008 n=5+5)

For a simple application that I wrote, which reads in a CSV file (via
ReadAll) and outputs the number of rows read (15857625 rows), this change
reduces the total time on my notebook from ~58 seconds to ~48 seconds.

This reduces time and allocations (bytes) each by ~6% for a real world
CSV file at work (~230000 rows, 13 colums).

Updates #16791

Change-Id: Ia07177c94624e55cdd3064a7d2751fb69322d3e4
Reviewed-on: https://go-review.googlesource.com/24723Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

plive.go (except for printeffects and livenessprintblock) and
reflect.go changes were prepared mechanically with gofmt -r.

Passes toolstash.

name       old alloc/op    new alloc/op    delta
Template      44.3MB ± 0%     44.3MB ± 0%    ~           (p=0.367 n=30+30)
Unicode       37.4MB ± 0%     37.4MB ± 0%    ~           (p=0.665 n=30+30)
GoTypes        125MB ± 0%      125MB ± 0%    ~           (p=0.067 n=30+30)
Compiler       515MB ± 0%      515MB ± 0%    ~           (p=0.542 n=30+28)

name       old allocs/op   new allocs/op   delta
Template        434k ± 0%       434k ± 0%    ~           (p=0.076 n=30+29)
Unicode         367k ± 0%       367k ± 0%    ~           (p=0.716 n=29+30)
GoTypes        1.24M ± 0%      1.24M ± 0%    ~           (p=0.428 n=29+29)
Compiler       4.47M ± 0%      4.47M ± 0%    ~           (p=0.225 n=28+30)

Change-Id: Ibaf0668567b3f69fba06aa03b7997c8fb152113a
Reviewed-on: https://go-review.googlesource.com/30356
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Always close the file regardless of whether the copy succeeds or fails.
Pass along the close error if the copy succeeds

Fixes #16296

Change-Id: Ib394655b91d25750f029f17b3846d985f673fb50
Reviewed-on: https://go-review.googlesource.com/30410Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

It already implemented the Timeout method,
but implementing the full net.Error is more convenient.

Fixes #14238 (again).

Change-Id: Ia87f897f0f35bcb49865e2355964049227951ca6
Reviewed-on: https://go-review.googlesource.com/30370
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also adds two tests: one to exercise the counter incrementing code
and one which checks the output of the optimized implementation
against that of the generic implementation for large/unaligned data
sizes.

Uses the KIMD instruction for GHASH and the KMCTR instruction for AES
in counter mode.

AESGCMSeal1K  75.0MB/s ± 2%  1008.7MB/s ± 1%  +1245.71%  (p=0.000 n=10+10)
AESGCMOpen1K  75.3MB/s ± 1%  1006.0MB/s ± 1%  +1235.59%   (p=0.000 n=10+9)
AESGCMSeal8K  78.5MB/s ± 1%  1748.4MB/s ± 1%  +2127.34%   (p=0.000 n=9+10)
AESGCMOpen8K  78.5MB/s ± 0%  1752.7MB/s ± 0%  +2134.07%   (p=0.000 n=10+9)

Change-Id: I88dbcfcb5988104bfd290ae15a60a2721c1338be
Reviewed-on: https://go-review.googlesource.com/30361Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Should fix the clang builder.

Change-Id: I3ee34581b6a7ec902420de72a8a08a2426997782
Reviewed-on: https://go-review.googlesource.com/30363
Run-TryBot: Michael Munday <munday@ca.ibm.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I9783d8023d453a72c4605a308064bef98168bcb8
Reviewed-on: https://go-review.googlesource.com/30360Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #17006

Change-Id: I3c2060ca5384a4b9782a7d804305d2cf4388dd5a
Reviewed-on: https://go-review.googlesource.com/29014
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Calling cgocallback from a signal handler can fail when using the race
detector. Calling cgocallback will lead to a call to newextram which
will call oneNewExtraM which will call racegostart. The racegostart
function will set up some race detector data structures, and doing that
will sometimes call the C memory allocator. If we are running the signal
handler from a signal that interrupted the C memory allocator, we will
crash or hang.

Instead, change the signal handler code to call needm and dropm. The
needm function will grab allocated m and g structures and initialize the
g to use the current stack--the signal stack. That is all we need to
safely call code that allocates memory and checks whether it needs to
split the stack. This may temporarily leave us with no m available to
run a cgo callback, but that is OK in this case since the code we call
will quickly either crash or call dropm to return the m.

Implementing this required changing some of the setSignalstackSP
functions to avoid a write barrier. These functions never need a write
barrier but in some cases generated one anyhow because on some systems
the ss_sp field is a pointer.

Change-Id: I3893f47c3a66278f85eab7f94c1ab11d4f3be133
Reviewed-on: https://go-review.googlesource.com/30218
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

Change-Id: I56de359a5ccdc0a10925cd372fa86534353c6ca0
Reviewed-on: https://go-review.googlesource.com/30358
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Benchmarks broken off from https://golang.org/cl/24723 and modified to
allocate less in the places we're not trying to measure.

Updates #16791

Change-Id: I508e4cfeac60322d56f1d71ff1912f6a6f183a63
Reviewed-on: https://go-review.googlesource.com/30357
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

All the prefixes of the testGIF produce errors today,
but they differ wildly in which errors: some are io.EOF,
others are io.ErrUnexpectedEOF, and others are gif-specific.
Make them all gif-specific to explain context, and make
any complaining about EOF be sure to mention the EOF
is unexpected.

Fixes #11390.

Change-Id: I742c39c88591649276268327ea314e68d1de1845
Reviewed-on: https://go-review.googlesource.com/17493
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #11441.

Test tables generated by

	package main

	import (
		"bytes"
		"fmt"
		"log"
		"os/exec"
		"strconv"
		"strings"
	)

	var inputs = []float64{
		0.5,
		1.5,
		2.5,
		3.5,
		-0.5,
		-1.5,
		-2.5,
		-3.5,
		0.1,
		0.01,
		1e-8,
		1e-16,
		1e-3,
		1e-16,
		1e-308,
		5.6e-309,
		5.5e-309,
		1e-309,
		1e-323,
		5e-324,
		-0.1,
		-0.01,
		-1e-8,
		-1e-16,
		-1e-3,
		-1e-16,
		-1e-308,
		-5.6e-309,
		-5.5e-309,
		-1e-300 / 1e9,
		-1e-300 / 1e23,
		-5e-300 / 1e24,
		-0.9999999999999999,
		-1.0000000000000002,
		-1.9999999999999998,
		-2.0000000000000004,
		-100.00000000000001,
		-99.999999999999986,
		17,
		171,
		171.6,
		171.624,
		171.625,
		172,
		2000,
		-100.5,
		-160.5,
		-170.5,
		-171.5,
		-176.5,
		-177.5,
		-178.5,
		-179.5,
		-201.0001,
		-202.9999,
		-1000.5,
		-1000000000.3,
		-4503599627370495.5,
		-63.349078729022985,
		-127.45117632943295,
	}

	func main() {
		var buf bytes.Buffer
		for _, v := range inputs {
			fmt.Fprintf(&buf, "gamma(%.1000g)\n", v)
		}
		cmd := exec.Command("gp", "-q")
		cmd.Stdin = &buf
		out, err := cmd.CombinedOutput()
		if err != nil {
			log.Fatalf("gp: %v", err)
		}
		f := strings.Split(string(out), "\n")
		if len(f) > 0 && f[len(f)-1] == "" {
			f = f[:len(f)-1]
		}
		if len(f) != len(inputs) {
			log.Fatalf("gp: wrong output count\n%s\n", out)
		}
		for i, g := range f {
			gf, err := strconv.ParseFloat(strings.Replace(g, " E", "e", -1), 64)
			if err != nil {
				if strings.Contains(err.Error(), "value out of range") {
					if strings.HasPrefix(g, "-") {
						fmt.Printf("\t{%g, Inf(-1)},\n", inputs[i])
					} else {
						fmt.Printf("\t{%g, Inf(1)},\n", inputs[i])
					}
					continue
				}
				log.Fatal(err)
			}
			if gf == 0 && strings.HasPrefix(g, "-") {
				fmt.Printf("\t{%g, Copysign(0, -1)},\n", inputs[i])
				continue
			}
			fmt.Printf("\t{%g, %g},\n", inputs[i], gf)
		}
	}

Change-Id: Ie98c7751d92b8ffb40e8313f5ea10df0890e2feb
Reviewed-on: https://go-review.googlesource.com/30146
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Quentin Smith <quentin@golang.org>

The 387 implementation is less accurate and slower.

name     old time/op  new time/op  delta
Exp-8    29.7ns ± 2%  24.0ns ± 2%  -19.08%  (p=0.000 n=10+10)

This makes Gamma more accurate too.

Change-Id: Iad33b9cce0b087ccbce3e08ba7a6d285c4999d02
Reviewed-on: https://go-review.googlesource.com/30230
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Quentin Smith <quentin@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The documentation for doc says:
> Doc prints the documentation comments associated with the item identified by its
> arguments (a package, const, func, type, var, or method) followed by a one-line
> summary of each of the first-level items "under" that item (package-level
> declarations for a package, methods for a type, etc.).

Certain variables (and constants, functions, and types) have value specifications
that are multiple lines long. Prior to this change, doc would print out all of the
lines necessary to display the value. This is inconsistent with the documented
behavior, which guarantees a one-line summary for all first-level items.
We fix this here by writing a general oneLineNode method that always returns
a one-line summary (guaranteed!) of any input node.

Packages like image/color/palette and unicode now become much
more readable since large slices are now a single line.

$ go doc image/color/palette
<<<
// Before:
var Plan9 = []color.Color{
	color.RGBA{0x00, 0x00, 0x00, 0xff},
	color.RGBA{0x00, 0x00, 0x44, 0xff},
	color.RGBA{0x00, 0x00, 0x88, 0xff},
	... // Hundreds of more lines!
}
var WebSafe = []color.Color{
	color.RGBA{0x00, 0x00, 0x00, 0xff},
	color.RGBA{0x00, 0x00, 0x33, 0xff},
	color.RGBA{0x00, 0x00, 0x66, 0xff},
	... // Hundreds of more lines!
}

// After:
var Plan9 = []color.Color{ ... }
var WebSafe = []color.Color{ ... }
>>>

In order to test this, I ran `go doc` and `go doc -u` on all of the
standard library packages and diff'd the output with and without the
change to ensure that all differences were intended.

Fixes #13072

Change-Id: Ida10b7796b7e4e174a929b55c60813a9eb7158fe
Reviewed-on: https://go-review.googlesource.com/25420
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I3f13488605ab62eba5d3c59d5e9df1bcf69dd571
Reviewed-on: https://go-review.googlesource.com/30355Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

For #16339

Change-Id: I8927f40e0fd166795f41c784ad92449743f73af5
Reviewed-on: https://go-review.googlesource.com/30213Reviewed-by: Matthew Dempsky <mdempsky@google.com>

For #16339.

Change-Id: Ie2e3338b87e84f45cda0868213bbcd2dae9ab6e3
Reviewed-on: https://go-review.googlesource.com/30212Reviewed-by: Matthew Dempsky <mdempsky@google.com>

For now, we also accept "type p = p.T" (using = instead of =>, for
type aliases only), so we can experiment with an approach that only
uses type aliases. This concession is implemened in the parser.

For #16339

Change-Id: I88b5522a8b6cfc2e97ca146ede8b32af340220f8
Reviewed-on: https://go-review.googlesource.com/30211Reviewed-by: Matthew Dempsky <mdempsky@google.com>

For #16339.

Change-Id: I0f83e46f13b5c8801aacf48fc8b690049edbbbff
Reviewed-on: https://go-review.googlesource.com/30210Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Also add a benchmark that shows off the new behavior.  The
existing benchmarks reuse the same slice, and thus don't ever have
to clear memory.  Running the Append|Grow benchmarks in runtime:

name                              old time/op  new time/op  delta
AppendSliceLarge/1024Bytes-12      265ns ± 1%   265ns ± 3%     ~     (p=0.524 n=17+20)
AppendSliceLarge/4096Bytes-12      807ns ± 3%   772ns ± 1%   -4.38%  (p=0.000 n=20+20)
AppendSliceLarge/16384Bytes-12    3.20µs ± 4%  2.82µs ± 4%  -11.93%  (p=0.000 n=19+20)
AppendSliceLarge/65536Bytes-12    13.0µs ± 4%  11.0µs ± 3%  -15.22%  (p=0.000 n=20+20)
AppendSliceLarge/262144Bytes-12   62.7µs ± 1%  51.6µs ± 1%  -17.67%  (p=0.000 n=19+20)
AppendSliceLarge/1048576Bytes-12   337µs ± 3%   289µs ± 3%  -14.36%  (p=0.000 n=20+20)
GrowSliceBytes-12                 31.2ns ± 4%  31.4ns ±11%     ~     (p=0.308 n=19+18)
GrowSliceInts-12                  53.4ns ±14%  45.0ns ± 6%  -15.74%  (p=0.000 n=20+19)
GrowSlicePtr-12                   87.0ns ± 3%  83.3ns ± 3%   -4.26%  (p=0.000 n=18+17)
GrowSliceStruct24Bytes-12         88.9ns ± 5%  77.8ns ± 2%  -12.45%  (p=0.000 n=20+19)
Append-12                         17.2ns ± 1%  17.3ns ± 2%     ~     (p=0.464 n=18+17)
AppendGrowByte-12                 2.28ms ± 1%  1.92ms ± 2%  -15.65%  (p=0.000 n=20+18)
AppendGrowString-12                255ms ± 3%   253ms ± 4%     ~     (p=0.065 n=19+19)
AppendSlice/1Bytes-12             3.13ns ± 0%  3.11ns ± 1%   -0.65%  (p=0.000 n=17+18)
AppendSlice/4Bytes-12             3.02ns ± 2%  3.11ns ± 1%   +3.27%  (p=0.000 n=18+17)
AppendSlice/7Bytes-12             4.14ns ± 3%  4.13ns ± 2%     ~     (p=0.380 n=19+18)
AppendSlice/8Bytes-12             3.74ns ± 3%  3.68ns ± 1%   -1.76%  (p=0.000 n=19+18)
AppendSlice/15Bytes-12            4.03ns ± 2%  4.04ns ± 2%     ~     (p=0.261 n=19+20)
AppendSlice/16Bytes-12            4.03ns ± 2%  4.03ns ± 0%     ~     (p=0.062 n=18+17)
AppendSlice/32Bytes-12            3.23ns ± 4%  3.43ns ± 1%   +6.10%  (p=0.000 n=17+18)
AppendStr/1Bytes-12               3.51ns ± 1%  3.52ns ± 1%     ~     (p=0.321 n=18+19)
AppendStr/4Bytes-12               3.46ns ± 1%  3.46ns ± 1%     ~     (p=0.977 n=18+20)
AppendStr/8Bytes-12               3.18ns ± 1%  3.19ns ± 1%     ~     (p=0.650 n=16+17)
AppendStr/16Bytes-12              6.08ns ±27%  5.52ns ± 3%   -9.16%  (p=0.002 n=18+19)
AppendStr/32Bytes-12              3.71ns ± 1%  3.53ns ± 1%   -4.73%  (p=0.000 n=20+19)
AppendSpecialCase-12              17.7ns ± 1%  17.8ns ± 3%   +0.86%  (p=0.045 n=17+18)
AppendInPlace/NoGrow/Byte-12       375ns ± 1%   376ns ± 1%   +0.35%  (p=0.021 n=20+18)
AppendInPlace/NoGrow/1Ptr-12      1.01µs ± 1%  1.10µs ± 1%   +9.28%  (p=0.000 n=18+20)
AppendInPlace/NoGrow/2Ptr-12      1.85µs ± 2%  1.71µs ± 1%   -7.51%  (p=0.000 n=19+18)
AppendInPlace/NoGrow/3Ptr-12      2.57µs ± 2%  2.44µs ± 1%   -5.08%  (p=0.000 n=19+19)
AppendInPlace/NoGrow/4Ptr-12      3.52µs ± 2%  3.35µs ± 2%   -4.70%  (p=0.000 n=20+19)
AppendInPlace/Grow/Byte-12         212ns ± 1%   217ns ± 8%   +2.57%  (p=0.000 n=20+20)
AppendInPlace/Grow/1Ptr-12         214ns ± 2%   217ns ± 3%   +1.23%  (p=0.001 n=18+19)
AppendInPlace/Grow/2Ptr-12         298ns ± 2%   300ns ± 2%   +0.55%  (p=0.038 n=19+20)
AppendInPlace/Grow/3Ptr-12         367ns ± 2%   366ns ± 2%     ~     (p=0.452 n=20+18)
AppendInPlace/Grow/4Ptr-12         416ns ± 2%   411ns ± 2%   -1.18%  (p=0.000 n=20+19)
StackGrowth-12                    43.4ns ± 1%  43.4ns ± 0%     ~     (p=1.000 n=16+16)
StackGrowthDeep-12                11.4µs ± 4%  10.3µs ± 4%   -9.65%  (p=0.000 n=20+19)

Change-Id: I69a8afbd942c787c591d95b9d9439bd6db4d1e49
Reviewed-on: https://go-review.googlesource.com/30192Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

BlockCall was removed in golang.org/cl/28950.

Change-Id: Ib8d9f3111bf3dc01956dd776afeb345ede8bc933
Reviewed-on: https://go-review.googlesource.com/30353Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ie7b869892816a171d8c71612998cc32a190aeff9
Reviewed-on: https://go-review.googlesource.com/17227
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Passes toolstash/buildall.

Change-Id: I928a2ef39fb10091957f35bb3f1564498f6f1b83
Reviewed-on: https://go-review.googlesource.com/30312
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Remove the use of io.ReadAll in http.parsePostForm to avoid converting
the whole input from []byte to string and not performing well
space-allocated-wise.

Instead a new function called parsePostFormURLEncoded is used and is
fed directly an io.Reader that is parsed using a bufio.Reader.

Benchmark:

name         old time/op    new time/op    delta
PostQuery-4    2.90µs ± 6%    2.82µs ± 4%     ~       (p=0.094 n=9+9)

name         old alloc/op   new alloc/op   delta
PostQuery-4    1.05kB ± 0%    0.90kB ± 0%  -14.49%  (p=0.000 n=10+10)

name         old allocs/op  new allocs/op  delta
PostQuery-4      6.00 ± 0%      7.00 ± 0%  +16.67%  (p=0.000 n=10+10)

Fixes #14655

Change-Id: I112c263d4221d959ed6153cfe88bc57a2aa8ea73
Reviewed-on: https://go-review.googlesource.com/20301Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Todd originally set cmpDepth to 4.  Quoting:

I picked a depth of 4 by timing tests of `go tool compile arithConst_ssa.go` and `go test -c net/http`.

    3.89 / 3.92  CL w/cmpDepth = 1
    3.78 / 3.92  CL w/cmpDepth = 2
    3.44 / 3.96  CL w/cmpDepth = 3
    3.29 / 3.9   CL w/cmpDepth = 4
    3.3  / 3.93  CL w/cmpDepth = 5
    3.29 / 3.92  CL w/cmpDepth = 10

I don't see the same behavior now, differences in those two benchmarks
are in the noise (between 1 and 4).

In issue 17127, CSE takes a really long time.  Lowering cmpDepth
from 4 to 1 lowers compile time from 8 minutes to 1 minute.

Fixes #17127

Change-Id: I6dc544bbcf2a9dca73637d0182d3de1a5ae6c944
Reviewed-on: https://go-review.googlesource.com/30257
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Missed one in the prior CL.

Change-Id: I6f6d84d52fe4d902a985971a402701fb3b1eed86
Reviewed-on: https://go-review.googlesource.com/30255Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Implementation of spec change https://golang.org/cl/24190/.

For #16085.

Change-Id: Ib7cb513354269282dfad663c7d2c6e624149f3cd
Reviewed-on: https://go-review.googlesource.com/30191Reviewed-by: David Crawshaw <crawshaw@golang.org>

Implementation of spec change https://golang.org/cl/24190/.

For #16085.

Change-Id: I17bbbce38d98a169bc64e84983a7ebfe7142f6e9
Reviewed-on: https://go-review.googlesource.com/30190Reviewed-by: Alan Donovan <adonovan@google.com>

Implementation of spec change https://golang.org/cl/24190/.

For #16085.

Change-Id: Id71ef29af5031b073e8be163f578d1bb768ff97a
Reviewed-on: https://go-review.googlesource.com/30169Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Does not pass toolstash, but only because it causes ATYPE instructions
to be emitted in a different order, and it avoids emitting type
metadata for unused variables.

Change-Id: I3ec8f66a40b5af9213e0d6e852b267a8dd995838
Reviewed-on: https://go-review.googlesource.com/30217
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This is a backwards-compatible language change.

Per the proposal (#16085), the rules for conversions are relaxed
such that struct tags in any of the structs involved in the conversion
are ignored (recursively).

Because this is loosening the existing rules, code that compiled so
far will continue to compile.

For #16085.
Fixes #6858.

Change-Id: I0feef651582db5f23046a2331fc3f179ae577c45
Reviewed-on: https://go-review.googlesource.com/24190Reviewed-by: Russ Cox <rsc@golang.org>