On Plan 9, there's no "kill all threads" system call, so exit is done
by sending a "go: exit" note to each OS process.  If concurrent GC
occurs during this loop, deadlock sometimes results.  Prevent this by
incrementing m.locks before sending notes.

Change-Id: I31aa15134ff6e42d9a82f9f8a308620b3ad1b1b1
Reviewed-on: https://go-review.googlesource.com/20477Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This prevents a fatal "missing stackmap" error if garbage collection
occurs during exit.

Also annotate argument sizes for "go vet".

Change-Id: I2473e0ef6aef8f26d0bbeaee9bd8f8a52eaaf941
Reviewed-on: https://go-review.googlesource.com/20476Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* Move lowering into a separate pass.
* SliceLen/SliceCap is now available to various intermediate passes
which use useful for bounds checking.
* Add a second opt pass to handle the new opportunities

Decreases the code size of binaries in pkg/tool/linux_amd64
by ~45K.

Updates #14564 #14606

Change-Id: I5b2bd6202181c50623a3585fbf15c0d6db6d4685
Reviewed-on: https://go-review.googlesource.com/20172
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

It's only used once, so just make the caller responsible for iterating
both the receiver and input params.

Change-Id: Icb34f3f0cf96e80fbe27f3f49d12eddc26599b92
Reviewed-on: https://go-review.googlesource.com/20454Reviewed-by: Dave Cheney <dave@cheney.net>

so the code is more readable.

Also use n[i] = val instead of n = append(n, val),
because this avoids a function call to append.

NOTE: compiles, but I had trouble running toolstash -cmp and need sleep
now.

@Ian this might save you some grunt work :-)

Change-Id: I2a4c70396c58905f7d5aabf83f3020f11dea0e89
Reviewed-on: https://go-review.googlesource.com/20430Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This helps follow-up CLs ensure that the encoding's core computation does not
allocate. It is a separate CL because it has a non-trivial effect on the
benchmark numbers, even if it's purely an accounting change and not a change to
the underlying performance:

BenchmarkEncodeDigitsSpeed1e4-4        5.65         19.31        3.42x
BenchmarkEncodeDigitsSpeed1e5-4        17.23        26.79        1.55x
BenchmarkEncodeDigitsSpeed1e6-4        26.85        27.51        1.02x
BenchmarkEncodeDigitsDefault1e4-4      4.41         13.21        3.00x
BenchmarkEncodeDigitsDefault1e5-4      5.64         6.28         1.11x
BenchmarkEncodeDigitsDefault1e6-4      5.54         5.65         1.02x
BenchmarkEncodeDigitsCompress1e4-4     4.31         13.15        3.05x
BenchmarkEncodeDigitsCompress1e5-4     5.52         5.91         1.07x
BenchmarkEncodeDigitsCompress1e6-4     5.38         5.63         1.05x
BenchmarkEncodeTwainSpeed1e4-4         5.45         19.06        3.50x
BenchmarkEncodeTwainSpeed1e5-4         17.30        29.25        1.69x
BenchmarkEncodeTwainSpeed1e6-4         28.06        30.86        1.10x
BenchmarkEncodeTwainDefault1e4-4       4.06         12.36        3.04x
BenchmarkEncodeTwainDefault1e5-4       6.15         7.62         1.24x
BenchmarkEncodeTwainDefault1e6-4       6.84         6.99         1.02x
BenchmarkEncodeTwainCompress1e4-4      4.06         12.27        3.02x
BenchmarkEncodeTwainCompress1e5-4      5.29         5.92         1.12x
BenchmarkEncodeTwainCompress1e6-4      5.24         5.29         1.01x

Change-Id: I7d32866b7e2d478b0154332c1edeefe339af9a28
Reviewed-on: https://go-review.googlesource.com/20467Reviewed-by: David Symonds <dsymonds@golang.org>

Adds a type of output to Examples that allows tests to have unordered
output. This is intended to help clarify when the output of a command
will produce a fixed return, but that return might not be in an constant
order.

Examples where this is useful would be documenting the rand.Perm()
call, or perhaps the (os.File).Readdir(), both of which can not guarantee
order, but can guarantee the elements of the output.

Fixes #10149

Change-Id: Iaf0cf1580b686afebd79718ed67ea744f5ed9fc5
Reviewed-on: https://go-review.googlesource.com/19280Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: Ia22f681b0e90876ec87363c50c6a284db050f649
Reviewed-on: https://go-review.googlesource.com/19793Reviewed-by: Andrew Gerrand <adg@golang.org>

Passes toolstash -cmp.

Change-Id: I6ec2143a30c1f2c15f8ec74422c954ed6b9b1a0f
Reviewed-on: https://go-review.googlesource.com/20452Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Suggested by Dave Cheney in golang.org/cl/20405.

Change-Id: I581c11ae80034cb6ebef3de976e8ae9484472322
Reviewed-on: https://go-review.googlesource.com/20453Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL was automatically generated using a special-purpose AST
rewriting tool, followed by manual editing to put some comments back in
the right places and fix some bad line breaks.

The result is not perfect but it's a big step toward getting back to
sanity, and because it was automatically generated there is a decent
chance that it is correct.

Passes toolstash -cmp.

Update #14473.

Change-Id: I01c09078a6d78e2b008bc304d744b79469a38d3d
Reviewed-on: https://go-review.googlesource.com/20440Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

More idiomatic naming (in particular, matches the naming used for
go/types.Signature).

Also, convert more code to use these methods and/or IterFields.
(Still more to go; only made a quick pass for low hanging fruit.)

Passes toolstash -cmp.

Change-Id: I61831bfb1ec2cd50d4c7efc6062bca4e0dcf267b
Reviewed-on: https://go-review.googlesource.com/20451Reviewed-by: Ian Lance Taylor <iant@golang.org>

Alternative to golang.org/cl/19852. This memory layout doesn't have
an easy type representation, but it is noticeably smaller than the
current funcType, and saves significant extra space.

Some notes on the layout are in reflect/type.go:

// A *rtype for each in and out parameter is stored in an array that
// directly follows the funcType (and possibly its uncommonType). So
// a function type with one method, one input, and one output is:
//
//	struct {
//		funcType
//		uncommonType
//		[2]*rtype    // [0] is in, [1] is out
//		uncommonTypeSliceContents
//	}

There are three arbitrary limits introduced by this CL:

1. No more than 65535 function input parameters.
2. No more than 32767 function output parameters.
3. reflect.FuncOf is limited to 128 parameters.

I don't think these are limits in practice, but are worth noting.

Reduces godoc binary size by 2.4%, 330KB.

For #6853.

Change-Id: I225c0a0516ebdbe92d41dfdf43f716da42dfe347
Reviewed-on: https://go-review.googlesource.com/19916Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #14662

Change-Id: I8f7d5e8d2dd8dc763e940e061b424427359246e7
Reviewed-on: https://go-review.googlesource.com/20462Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Iaa23d27043e6a050075b40072e466623418ba977
Reviewed-on: https://go-review.googlesource.com/19878Reviewed-by: Rob Pike <r@golang.org>

Passes toolstash -cmp.

Change-Id: I325b02dcc8412ded0dc304d43377c0bdf59c66a8
Reviewed-on: https://go-review.googlesource.com/20405Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #14687

Change-Id: I51fd8842d35c82db71cc5b28c4c0550871461eb6
Reviewed-on: https://go-review.googlesource.com/20421Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Instead of a pointer on every rtype, use a bit flag to indicate that
the contents of uncommonType directly follows the rtype value when it
is needed.

This requires a bit of juggling in the compiler's rtype encoder. The
backing arrays for fields in the rtype are presently encoded directly
after the slice header. This packing requires separating the encoding
of the uncommonType slice headers from their backing arrays.

Reduces binary size of godoc by ~180KB (1.5%).
No measurable change in all.bash time.
For #6853.

Change-Id: I60205948ceb5c0abba76fdf619652da9c465a597
Reviewed-on: https://go-review.googlesource.com/19790Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Converting an and-K into a pair of shifts for K that will
fit in a one-byte argument is probably not an optimization,
and it also interferes with other patterns that we want to
see fire, like (<< (AND K)) [for small K] and bounds check
elimination for masked indices.

Turns out that on Intel, even 32-bit signed immediates beat
the shift pair; the size reduction of tool binaries is 0.09%
vs 0.07% for only the 8-bit immediates.

RLH found this one working on the new/next GC.

Change-Id: I2414a8de1dd58d680d18587577fbadb7ff4f67d9
Reviewed-on: https://go-review.googlesource.com/20410Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>

Some cleaned up documentation, but no code changes.

Change-Id: I145398bb6d118c626ab3873ef75dbb64ebc286e9
Reviewed-on: https://go-review.googlesource.com/20404
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Don't do a substring search to test for a timeout error.

Fixes #14722 (maybe)

Change-Id: I4e18c749d6fd92c084a1b0b83a805119e1ae5ff2
Reviewed-on: https://go-review.googlesource.com/20403
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* Simplify the nilcheck generated by
for _, e := range a {}
* No effect on the generated code because these nil checks
don't end up in the generated code.
* Useful for other analysis, e.g. it'll remove one dependecy
on the induction variable.

Change-Id: I6ee66ddfdc010ae22aea8dca48163303d93de7a9
Reviewed-on: https://go-review.googlesource.com/20307
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Make more idiomatic with a defer cleanup, which allows declaring
variables closer to their first use, rather than up front before the
first goto statement.

Also, split the legacy code generation code path into a separate
genlegacy function, analogous to the new genssa.

Passes toolstash -cmp.

Change-Id: I86c22838704f6861b75716ae64ba103b0e73b12f
Reviewed-on: https://go-review.googlesource.com/20353Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Same idea as golang.org/cl/20322.

Passes toolstash/buildall.

Change-Id: Ida5960e57ff6e1e8de75c2720f21aeae56a8e415
Reviewed-on: https://go-review.googlesource.com/20352
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Iec323998133ef20ff962f06a46d15dd342a82f5f
Reviewed-on: https://go-review.googlesource.com/20390Reviewed-by: Ian Lance Taylor <iant@golang.org>

getgrouplist is non-standard and has slightly different semantics on
each platform.  Darwin defines the function in terms of ints instead of
gid_ts.  Solaris only recently supported the call, so stubbing out for
now.

Fixes #14696
Fixes #14709

Change-Id: I5a44538d41594909efb6f3f9610c55d638c36757
Reviewed-on: https://go-review.googlesource.com/20348
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Accidentally added in https://golang.org/cl/20242.

This is in preparation for transformation by an automated tool.

Passes toolstash -cmp.

Update #14473.

Change-Id: I28c637d220df3ccaa8e368bfbea7282a6e66662e
Reviewed-on: https://go-review.googlesource.com/20402
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Before, those C files might have been intended for the Plan 9 C compiler,
but that option was removed in Go 1.5. We can simplify the maintenance
of cgo packages now if we assume C files (and C++ and M and SWIG files)
should only be considered when cgo is enabled.

Also remove newly unnecessary build tags in runtime/cgo's C files.

Fixes #14123

Change-Id: Ia5a7fe62b9469965aa7c3547fe43c6c9292b8205
Reviewed-on: https://go-review.googlesource.com/19613Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Bug accidentally inserted in https://golang.org/cl/20210.  Doesn't seem
to make a difference, but restore original code anyhow.

Update #14473.

Change-Id: I9cf87987ff158e27c7231027819317cdde8c132c
Reviewed-on: https://go-review.googlesource.com/20401
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Trailers() returns the headers that were set by the handler after the
headers were written "to the wire" (in this case HeaderMap) and that
were also specified in a proper header called "Trailer".

Neither HeaderMap or trailerMap (used for Trailers()) are manipulated by
the handler code, instead a third stagingMap is given to the
handler. This avoid a reference kept by handler to affect the recorded
results.

If a handler just modify the header but doesn't call any Write or Flush
method from ResponseWriter (or Flusher) interface, HeaderMap will not be
updated. In this case, calling Flush in the recorder is enough to get
the HeaderMap filled.

Fixes #14531.
Fixes #8857.

Change-Id: I42842341ec3e95c7b87d7e6f178c65cd03d63cc3
Reviewed-on: https://go-review.googlesource.com/20047Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14646.

Change-Id: I0bb82ed6d3533633cd8369ba37aa467948bbe155
Reviewed-on: https://go-review.googlesource.com/20381
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I754861147838d0f6c184d8deb8a028062a1d3214
Reviewed-on: https://go-review.googlesource.com/20400Reviewed-by: Russ Cox <rsc@golang.org>

Deleting the string merging pass makes the linker 30-35% faster
but makes jujud (using the github.com/davecheney/benchjuju snapshot) 2.5% larger.
Two optimizations bring the space overhead down to 0.6%.

First, change the default alignment for string data to 1 byte.
(It was previously defaulting to larger amounts, usually pointer width.)

Second, write out the type string for T (usually a bigger expression) as "*T"[1:],
so that the type strings for T and *T share storage.

Combined, these obtain the bulk of the benefit of string merging
at essentially no cost. The remaining benefit from string merging
is not worth the excessive cost, so delete it.

As penance for making the jujud binary 0.6% larger,
the next CL in this sequence trims the reflect functype
information enough to make the jujud binary overall 0.75% smaller
(that is, that CL has a net -1.35% effect).

For #6853.
Fixes #14648.

Change-Id: I3fdd74c85410930c36bb66160ca4174ed540fc6e
Reviewed-on: https://go-review.googlesource.com/20334Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>

cmd/link is clearly the way forward.
The original rationale for cmd/newlink was that it would be a clean Go reimplementation.
But when push came to shove, cmd/link got converted from C instead,
and all the work on build modes and the like is in cmd/link now.
Cleaning up cmd/link is likely a much better plan.

This directory is something to delete from releases and the
testdata is something that breaks every time the .6 format changes.
Fix both problems by just deleting it outright.

Change-Id: Ib00fecda258ba685f1752725971182af9d4459eb
Reviewed-on: https://go-review.googlesource.com/20380
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Passes toolstash -cmp.

Update #14473.

Change-Id: I717ebd948dfc8faf8b9ef5aa02c67484af618d18
Reviewed-on: https://go-review.googlesource.com/20359Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

benchstat master2 arg3b
name      old time/op    new time/op    delta
Template     441ms ± 4%     444ms ± 6%    ~     (p=0.335 n=22+25)
GoTypes      1.51s ± 2%     1.51s ± 2%    ~     (p=0.129 n=25+21)
Compiler     5.59s ± 1%     5.56s ± 2%  -0.65%  (p=0.001 n=24+21)

name      old alloc/op   new alloc/op   delta
Template    85.6MB ± 0%    85.3MB ± 0%  -0.40%  (p=0.000 n=25+24)
GoTypes      307MB ± 0%     305MB ± 0%  -0.38%  (p=0.000 n=25+25)
Compiler    1.06GB ± 0%    1.05GB ± 0%  -0.43%  (p=0.000 n=25+25)

name      old allocs/op  new allocs/op  delta
Template     1.10M ± 0%     1.09M ± 0%  -1.04%  (p=0.000 n=25+25)
GoTypes      3.36M ± 0%     3.32M ± 0%  -1.13%  (p=0.000 n=25+24)
Compiler     13.0M ± 0%     12.9M ± 0%  -1.12%  (p=0.000 n=25+25)

Change-Id: I1280b846e895c00b95bb6664958a7765bd819610
Reviewed-on: https://go-review.googlesource.com/20296Reviewed-by: Keith Randall <khr@golang.org>

Also, add more failure output to debug why linux/mips64le and
linux/ppc64 are failing. They should be working. I suspect their
builder test envs are missing something.

Change-Id: I97273fe72c4e3009db400394636d0da1ef147485
Reviewed-on: https://go-review.googlesource.com/20358
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This adds "slicing by 8" optimization to Castagnoli tables which will
speed up CRC32 calculation on systems without asssembler,
which are all but AMD64.

In my tests, it is faster to use "slicing by 8" for sizes all down to
16 bytes, so the switchover point has been adjusted.

There are no benchmarks for small sizes, so I have added one for 40 bytes,
as well as one for bigger sizes (32KB).

Castagnoli, No assembler, 40 Byte payload: (before, after)
BenchmarkCastagnoli40B-4   10000000     161 ns/op         246.94 MB/s
BenchmarkCastagnoli40B-4   20000000     100 ns/op         398.01 MB/s

Castagnoli, No assembler, 32KB payload: (before, after)
BenchmarkCastagnoli32KB-4     10000     115426 ns/op      283.89 MB/s
BenchmarkCastagnoli32KB-4     30000     45171 ns/op       725.41 MB/s

IEEE, No assembler, 1KB payload: (before, after)
BenchmarkCrc1KB-4       500000     3604 ns/op         284.10 MB/s
BenchmarkCrc1KB-4      1000000     1463 ns/op         699.79 MB/s

Compared:
benchmark                     old ns/op     new ns/op     delta
BenchmarkCastagnoli40B-4      161           100           -37.89%
BenchmarkCastagnoli32KB-4     115426        45171         -60.87%
BenchmarkCrc1KB-4             3604          1463          -59.41%

benchmark                     old MB/s     new MB/s     speedup
BenchmarkCastagnoli40B-4      246.94       398.01       1.61x
BenchmarkCastagnoli32KB-4     283.89       725.41       2.56x
BenchmarkCrc1KB-4             284.10       699.79       2.46x

Change-Id: I303e4ec84e8d4dafd057d64c0e43deb2b498e968
Reviewed-on: https://go-review.googlesource.com/19335
Run-TryBot: Brad Fitzpatrick <bradfitz@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     441ms ± 4%     446ms ± 4%  +1.23%  (p=0.048 n=22+25)
GoTypes      1.51s ± 2%     1.51s ± 2%    ~     (p=0.224 n=25+25)
Compiler     5.59s ± 1%     5.57s ± 2%  -0.38%  (p=0.019 n=24+24)

name      old alloc/op   new alloc/op   delta
Template    85.6MB ± 0%    85.6MB ± 0%  -0.11%  (p=0.000 n=25+24)
GoTypes      307MB ± 0%     305MB ± 0%  -0.45%  (p=0.000 n=25+25)
Compiler    1.06GB ± 0%    1.06GB ± 0%  -0.34%  (p=0.000 n=25+25)

name      old allocs/op  new allocs/op  delta
Template     1.10M ± 0%     1.10M ± 0%  -0.03%  (p=0.001 n=25+24)
GoTypes      3.36M ± 0%     3.35M ± 0%  -0.13%  (p=0.000 n=25+25)
Compiler     13.0M ± 0%     13.0M ± 0%  -0.12%  (p=0.000 n=25+24)

Change-Id: I7fc18acbc3b1588aececef9692e24a0bd3dba974
Reviewed-on: https://go-review.googlesource.com/20295
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: Ifa09bccb8482a6141d0aa862cef674fade30e2eb
Reviewed-on: https://go-review.googlesource.com/20355Reviewed-by: David Crawshaw <crawshaw@golang.org>