cmd/go: avoid registering AtExit handlers in tests

Ever since 'go build' was added (in CL 5483069), it has used an atexit
handler to clean up working directories.

CL 154109 introduced 'cc' command to the script test framework that
called Init on a builder once per invocation. Unfortunately, since
base.AtExit is unsynchronized, the Init added there caused any script
that invokes that command to be unsafe for concurrent use.

This change fixes the race by having the 'cc' command pass in its
working directory instead of allowing the Builder to allocate one.
Following modern Go best practices, it also replaces the in-place Init
method (which is prone to typestate and aliasing bugs) with a
NewBuilder constructor function.

Fixes #54423.

Change-Id: I8fc2127a7d877bb39a1174e398736bb51d03d4d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/425205
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>

cmd/compile: defer transitive inlining until after AST is edited

This CL changes the inliner to process transitive inlining iteratively
after the AST has actually been edited, rather than recursively and
immediately. This is important for handling indirect function calls
correctly, because ir.reassigned walks the function body looking for
reassignments; whereas previously the inlined reassignments might not
have been actually added to the AST yet.

Fixes #54632.

Change-Id: I0dd69813c8a70b965174e0072335bc00afedf286
Reviewed-on: https://go-review.googlesource.com/c/go/+/425257
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>

image/png: have DecodeConfig read tRNS chunks

Fixes #54325

Change-Id: Ie468180c4d6f21db7672dd71bd2a40f3a5881b7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/424917
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Nigel Tao (INACTIVE; USE @golang.org INSTEAD) <nigeltao@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

reflect: optimize Value.IsZero

If a struct or array is comparable, then we can leverage rtype.equal,
which is almost always faster than what Go reflection can achieve.

As a secondary optimization, pre-compute Value.Len and Value.NumField
outside of the loop conditional.

Performance:

name                       old time/op  new time/op  delta
IsZero/ArrayComparable      136ns ± 4%    16ns ± 1%  -88.28%  (p=0.008 n=5+5)
IsZero/ArrayIncomparable    197ns ±10%   123ns ± 1%  -37.74%  (p=0.008 n=5+5)
IsZero/StructComparable    26.4ns ± 0%   9.6ns ± 1%  -63.68%  (p=0.016 n=4+5)
IsZero/StructIncomparable  43.5ns ± 1%  27.8ns ± 1%  -36.21%  (p=0.008 n=5+5)

The incomparable types gain a performance boost since
they are generally constructed from nested comparable types.

Change-Id: If2c1929f8bb1b5b19306ef0c69f3c95a27d4b60d
Reviewed-on: https://go-review.googlesource.com/c/go/+/411478
Reviewed-by: Dan Kortschak <dan@kortschak.io>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

encoding/json: move some misplaced benchmark tests to bench_test.go

Change-Id: I5987eed00ee825421abe62699a06e9b66499f35f
Reviewed-on: https://go-review.googlesource.com/c/go/+/425016
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@google.com>
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Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
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internal/singleflight: make DoChan only return Result channel

So next CL can delete "internal/singleflight" and vendor
"golang.org/x/sync/singleflight" instead.

For #31697

Change-Id: I020da1e5a48d484637b538c010029218f5a4a744
Reviewed-on: https://go-review.googlesource.com/c/go/+/423655
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

net: avoid relying on singleflight.Group.DoChan to detect hook called

So next CLs can revert changes to "internal/singleflight" in CL #82795,
then replace it with "golang.org/x/sync/singleflight" instead.

For #31697

Change-Id: I873ce30d7e051539aa6dc5d4f21e558869a6d132
Reviewed-on: https://go-review.googlesource.com/c/go/+/423654
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Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>

cmd/internal/obj/loong64: add MASKEQZ and MASKNEZ instructions support

Change-Id: Ied16c3be47c863a94d46bd568191057ded4b7d0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/416734
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Run-TryBot: Wayne Zuo <wdvxdr@golangcn.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: xiaodong liu <teaofmoli@gmail.com>

runtime/pprof: remove round-to-file-start adjustment

This causes a problem in the test sometimes. With a mapping like:

00400000-00411000 r--p 00000000 fe:01 4459044                            /tmp/go-build1710804385/b001/pprof.test
00411000-00645000 r-xp 00011000 fe:01 4459044                            /tmp/go-build1710804385/b001/pprof.test

The removed code would make the first mapping 0x400000-0x645000. Tests
then grab the first few addresses to use as PCs, thinking they are in
an executable range. But those addresses are really not in an
executable range, causing the tests to fail.

Change-Id: I5a69d0259d1fd70ff9745df1cbad4d54c5898e7b
Reviewed-on: https://go-review.googlesource.com/c/go/+/424295
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Keith Randall <khr@golang.org>

cmd/compile: generic constant folding: Floor Ceil Trunc RoundToEven

Change-Id: I553a6d0bd3ae45e5bf62191411e71102b3f44cd8
Reviewed-on: https://go-review.googlesource.com/c/go/+/411215
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Reviewed-by: Joedian Reid <joedian@golang.org>
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Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

net/url: consistently remove ../ elements in JoinPath

JoinPath would fail to remove relative elements from the start of
the path when the first path element is "".

In addition, JoinPath would return the original path unmodified
when provided with no elements to join, violating the documented
behavior of always cleaning the resulting path.

Correct both these cases.

    JoinPath("http://go.dev", "../go")
    // before: http://go.dev/../go
    // after:  http://go.dev/go

    JoinPath("http://go.dev/../go")
    // before: http://go.dev/../go
    // after:  http://go.dev/go

Fixes #54385.

Change-Id: I6d22cd160d097c50703dd96e4f453c6c118fd5d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/423514
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

cmd/compile: move SSA rotate instruction detection to arch-independent rules

Detect rotate instructions while still in architecture-independent form.
It's easier to do here, and we don't need to repeat it in each
architecture file.

Change-Id: I9396954b3f3b3bfb96c160d064a02002309935bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/421195
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Eric Fang <eric.fang@arm.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
Reviewed-by: Ruinan Sun <Ruinan.Sun@arm.com>
Run-TryBot: Keith Randall <khr@golang.org>

cmd/compile: fix error message formatting in decomposeBuiltInPhi

Change-Id: Ib2b2eb6bebb59134f671a79739ee1acaf32ed443
Reviewed-on: https://go-review.googlesource.com/c/go/+/411217
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
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all: append(bytes, str...) works out of the box

From the append docs in the builtin package:

As a special case, it is legal to append a string to a byte slice, like this:

slice = append([]byte("hello "), "world"...)

Change-Id: Ib14039a7476873b12a3aefccd8863e8d628b9249
Reviewed-on: https://go-review.googlesource.com/c/go/+/425102
Reviewed-by: hopehook <hopehook@qq.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>
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net/http/httputil: do not duplicate 'Connection: close' headers

Fixes #54616.

Change-Id: I46f41bbccff7b49f26f60c1edf65acfd1701aed5
Reviewed-on: https://go-review.googlesource.com/c/go/+/425155
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>

syscall: rely on utf16.AppendRune

Using utf16.AppendRune instead of utf16.Encode safe a bunch
of allocations across the board, as many higher level functions
use it to call Windows syscalls, for example to `os` package:

name                old alloc/op   new alloc/op   delta
Readdirname-12        15.6kB ± 0%    15.6kB ± 0%   +0.26%  (p=0.008 n=5+5)
Readdir-12            29.4kB ± 0%    29.4kB ± 0%   +0.14%  (p=0.008 n=5+5)
ReadDir-12            29.4kB ± 0%    29.4kB ± 0%   +0.14%  (p=0.016 n=4+5)
StatDot-12              552B ± 0%      560B ± 0%   +1.45%  (p=0.008 n=5+5)
StatFile-12             512B ± 0%      336B ± 0%  -34.38%  (p=0.008 n=5+5)
StatDir-12              432B ± 0%      288B ± 0%  -33.33%  (p=0.008 n=5+5)
LstatDot-12             552B ± 0%      560B ± 0%   +1.45%  (p=0.008 n=5+5)
LstatFile-12            512B ± 0%      336B ± 0%  -34.38%  (p=0.008 n=5+5)
LstatDir-12             432B ± 0%      288B ± 0%  -33.33%  (p=0.008 n=5+5)
StatFile-12             4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.008 n=5+5)
StatDir-12              4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.008 n=5+5)
LstatFile-12            4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.008 n=5+5)
LstatDir-12             4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.008 n=5+5)

Updates #51786

Change-Id: I0a088cf1a96e9c304da9311bb3895b70443c1637
Reviewed-on: https://go-review.googlesource.com/c/go/+/425054
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
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debug/plan9obj: don't crash on EOF before symbol type

No debug/plan9obj test case because the problem can only happen for
invalid data. Let the fuzzer find cases like this.

For #47653
Fixes #54585

Change-Id: I8d3e15725b9bc09dd0e6f2750769987021f5e982
Reviewed-on: https://go-review.googlesource.com/c/go/+/425115
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>

debug/macho: don't use narch for seenArches map size

If narch is very large we would allocate a lot of memory for seenArches.
In practice we aren't going to see many different architectures so
don't bother to specify a size for the seenArches map.

No debug/macho test case because the problem can only happen for
invalid data. Let the fuzzer find cases like this.

For #47653
For #52523

Change-Id: I5a3b0e3aa6172ddffd6f44d9ae513c39a00d8764
Reviewed-on: https://go-review.googlesource.com/c/go/+/425114
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>

strconv: optimize Parse for []byte arguments

When one has a []byte on hand, but desires to call the Parse functions,
the conversion from []byte to string would allocate.

    var b []byte = ...
    v, err := strconv.ParseXXX(string(b), ...)

This changes it such that the input string never escapes from
any of the Parse functions. Together with the compiler optimization
where the compiler stack allocates any string smaller than 32B
this makes most valid inputs for strconv.ParseXXX(string(b), ...)
not require an allocation for the input string.
For example, the longest int64 or uint64 encoded in decimal is 20B.
Also, the longest decimal formatting of a float64 in appendix B
of RFC 8785 is 25B.

Previously, this was not possible since the input leaked to the error,
which causes the prover to give up and instead heap copy the []byte.
We fix this by copying the input string in the error case.
The advantage of this change is that you can now call strconv.ParseXXX
with a []byte without allocations (most times) in the non-error case.
The detriment is that the error-case now has an extra allocation.
We should optimize for the non-error path, rather than the error path.

The effects of this change is transitively seen through packages
that must use strconv.ParseXXX on a []byte such as "encoding/json":

    name              old time/op    new time/op    delta
    UnmarshalFloat64  186ns          157ns          -15.89%  (p=0.000 n=10+10)

    name              old alloc/op   new alloc/op   delta
    UnmarshalFloat64  148B           144B            -2.70%  (p=0.000 n=10+10)

    name              old allocs/op  new allocs/op  delta
    UnmarshalFloat64  2.00           1.00           -50.00%  (p=0.000 n=10+10)

In order for "encoding/json" to benefit, there needs to be a
small change made to how "encoding/json" calls strconv.ParseXXX.
That will be a future change.

Credit goes to Jeff Wendling for a similar patch.

Fixes #42429

Change-Id: I512d6927f965f82e95bd7ec14a28a587f23b7203
Reviewed-on: https://go-review.googlesource.com/c/go/+/345488
Reviewed-by: Martin Möhrmann <martin@golang.org>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

bytes: rely on utf8.AppendRune

This is both simpler and more performant.

WriteRune                                 23.9µs ± 1%   22.8µs ± 8%   -4.43%  (p=0.006 n=8+10)
ToUpper/longɐstringɐwithɐnonasciiⱯchars    573ns ± 4%    474ns ± 6%  -17.27%  (p=0.000 n=10+10)
ToUpper/ɐɐɐɐɐ                              236ns ± 6%    202ns ± 5%  -14.12%  (p=0.000 n=10+10)
ToUpper/a\u0080\U0010ffff                 98.8ns ± 6%   91.2ns ± 3%   -7.67%  (p=0.000 n=10+10)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS    511ns ± 3%    409ns ± 4%  -20.02%  (p=0.000 n=10+10)
ToLower/ⱭⱭⱭⱭⱭ                              178ns ± 4%    173ns ± 2%   -2.76%  (p=0.005 n=10+10)
ToLower/A\u0080\U0010ffff                  100ns ± 3%     91ns ± 2%   -8.55%  (p=0.000 n=10+10)

Change-Id: I968ef194da2c115cbdcac2d3575c34c65e6a8a56
Reviewed-on: https://go-review.googlesource.com/c/go/+/412337
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
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Reviewed-by: David Chase <drchase@google.com>
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runtime: name nil semaphore of pollDesc

Use explicit name pdNil for nil semaphore of a pollDesc to make it self-explanatory like pdReady and pdWait.

Change-Id: Ibfb246e14419d366edadbccac4d3717f0c135cb0
Reviewed-on: https://go-review.googlesource.com/c/go/+/424923
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>

strings: rely on utf8.AppendRune

This is both simpler and more performant.

Change-Id: I66ef8e49c059a722932392ee3ecfb951d9b8e121
Reviewed-on: https://go-review.googlesource.com/c/go/+/412339
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encoding/json: give it a chance to put encodeState back in pool when error occurs

name                       old time/op    new time/op    delta
CodeEncoderError-10           688µs ± 8%     496µs ±15%   -27.92%  (p=0.000 n=10+9)
CodeMarshalError-10           747µs ± 6%     546µs ± 4%   -26.86%  (p=0.000 n=10+10)
MarshalBytesError/32-10       284µs ± 2%     273µs ± 1%    -3.84%  (p=0.000 n=10+10)
MarshalBytesError/256-10      281µs ± 2%     278µs ± 4%      ~     (p=0.053 n=9+10)
MarshalBytesError/4096-10     290µs ± 1%     279µs ± 3%    -3.52%  (p=0.000 n=10+10)

name                       old speed      new speed      delta
CodeEncoderError-10        2.83GB/s ± 8%  3.84GB/s ±20%   +36.03%  (p=0.000 n=10+10)
CodeMarshalError-10        2.60GB/s ± 5%  3.56GB/s ± 4%   +36.61%  (p=0.000 n=10+10)

name                       old alloc/op   new alloc/op   delta
CodeEncoderError-10          4.05MB ± 1%    0.00MB ± 1%  -100.00%  (p=0.000 n=10+9)
CodeMarshalError-10          6.05MB ± 0%    1.99MB ± 1%   -67.13%  (p=0.000 n=10+10)
MarshalBytesError/32-10      66.0kB ± 0%     0.2kB ± 0%   -99.67%  (p=0.000 n=9+8)
MarshalBytesError/256-10     50.1kB ± 0%     0.9kB ± 0%   -98.23%  (p=0.000 n=9+9)
MarshalBytesError/4096-10    87.4kB ± 0%     7.5kB ± 0%   -91.47%  (p=0.000 n=8+10)

name                       old allocs/op  new allocs/op  delta
CodeEncoderError-10            25.0 ± 0%       4.0 ± 0%   -84.00%  (p=0.000 n=9+10)
CodeMarshalError-10            27.0 ± 0%       6.0 ± 0%   -77.78%  (p=0.000 n=10+10)
MarshalBytesError/32-10        18.0 ± 0%       5.0 ± 0%   -72.22%  (p=0.000 n=10+10)
MarshalBytesError/256-10       17.0 ± 0%       6.0 ± 0%   -64.71%  (p=0.000 n=10+10)
MarshalBytesError/4096-10      16.0 ± 0%       6.0 ± 0%   -62.50%  (p=0.000 n=10+10)

Change-Id: I48070bb05f55707251c694e40d2570403bbf61f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/423694
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>
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runtime: initialize pointer bits of noscan spans

Some code paths in the runtime (cgo, heapdump) request heap bits
without first checking that the span is !noscan. Instead of trying
to find and work around all those cases, just set the pointer bits
of noscan spans correctly. It's somewhat safer than ensuring we
caught all the possible cases.

Fixes #54557
Fixes #54558

Change-Id: Ibd476e6cdea77c962e4d15aad26f29df66fd94e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/425194
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

runtime: convert ticksType.val to atomic type

Updates #53821

Change-Id: Ia0c58d7e7e11a1b52bbb7c19ebbb131e3eea5314
Reviewed-on: https://go-review.googlesource.com/c/go/+/424926
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
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Reviewed-by: Michael Pratt <mpratt@google.com>

cmd/compile: handle partially overlapping assignments

Normally, when moving Go values of type T from one location to another,
we don't need to worry about partial overlaps. The two Ts must either be
in disjoint (nonoverlapping) memory or in exactly the same location.
There are 2 cases where this isn't true:
 1) Using unsafe you can arrange partial overlaps.
 2) Since Go 1.17, you can use a cast from a slice to a ptr-to-array.
    https://go.dev/ref/spec#Conversions_from_slice_to_array_pointer
    This feature can be used to construct partial overlaps of array types.
      var a [3]int
      p := (*[2]int)(a[:])
      q := (*[2]int)(a[1:])
      *p = *q
We don't care about solving 1. Or at least, we haven't historically
and no one has complained.
For 2, we need to ensure that if there might be partial overlap,
then we can't use OpMove; we must use memmove instead.
(memmove handles partial overlap by copying in the correct
direction. OpMove does not.)

Note that we have to be careful here not to introduce a call when
we're marshaling arguments to a call or unmarshaling results from a call.

Fixes #54467

Change-Id: I1ca6aba8041576849c1d85f1fa33ae61b80a373d
Reviewed-on: https://go-review.googlesource.com/c/go/+/425076
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
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Run-TryBot: Keith Randall <khr@golang.org>

Revert "cmd/compile: restore test/nested.go test cases"

This reverts CL 424854.

Reason for revert: broke misc/cgo/stdio.TestTestRun on several builders.

Will re-land after CL 421879 is submitted.

Change-Id: I2548c70d33d7c178cc71c1d491cd81c22660348f
Reviewed-on: https://go-review.googlesource.com/c/go/+/425214
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Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>

runtime: fix ppc64 startup on newer linux kernels

R0 needs to be cleared at startup as it may not always be cleared
by the kernel on newer kernels.

Fixes #54547

Change-Id: Id7055699aaa8d8b193b7e3e784f075ce29ac3f1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/424927
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>

all: use go/parser.SkipObjectResolution in more places

None of cgo, "go test", nor srcimporter make use of go/ast's object
resolution via go/ast.Object. As such, we can skip that work during
parse time, which should save some CPU time.

We don't have any benchmark numbers, as none of the three packages have
any usable benchmarks, but we measured gofmt to be about 5% faster
thanks to this tweak in https://go.dev/cl/401454.
These three packages are quite different to gofmt, but one can expect
similar speed-ups in the 1-5% range.

Two notable exceptions, which do make use of go/ast.Object, are cmd/fix
and cmd/doc - we do not modify those here.

See #46485.

Change-Id: Ie3e65600d4790641c4e4d6f1c379be477fa02cee
Reviewed-on: https://go-review.googlesource.com/c/go/+/401455
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Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: David Chase <drchase@google.com>
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encoding/xml: add (*Encoder).Close

Flush can not check for unclosed elements, as more data might be encoded
after Flush is called. Close implicitly calls Flush and also checks that
all opened elements are closed as well.

Fixes #53346

Change-Id: I889b9f5ae54e5dfabb9e6948d96c5ed7bc1110f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/424777
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>

cmd/go/internal/modload: remove ImportMap and PackageDir

These two functions together duplicated much of the functionality of
modload.Lookup. Use that instead in modcmd.vendorPkg, and reduce the
modload surface area.

Updates #42504
Updates #40775
For #26904

Change-Id: Ib8aaac495d090178dd56971aef9e5aa44ffa818b
Reviewed-on: https://go-review.googlesource.com/c/go/+/332571
Reviewed-by: Michael Matloob <matloob@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: David Chase <drchase@google.com>
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Reviewed-by: Jay Conrod <jayconrod@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>

cmd/compile: mark booleans as registerizable

Boolean values fit in registers, mark them accordingly. Improves codegen a bit.

compilecmp for darwin/amd64:

compress/gzip
compress/gzip.(*Reader).Reset 1017 -> 985  (-3.15%)

net
net.newRequest 1002 -> 970  (-3.19%)

crypto/tls
crypto/tls.(*sessionState).unmarshal 1054 -> 968  (-8.16%)

cmd/compile/internal/syntax
cmd/compile/internal/syntax.Fprint 518 -> 453  (-12.55%)

cmd/vendor/github.com/ianlancetaylor/demangle
cmd/vendor/github.com/ianlancetaylor/demangle.ASTToString 389 -> 325  (-16.45%)

cmd/go/internal/load
cmd/go/internal/load.PackagesAndErrors 3453 -> 3381  (-2.09%)

cmd/compile/internal/ssa
cmd/compile/internal/ssa.registerizable 249 -> 255  (+2.41%)

cmd/compile/internal/ssagen
cmd/compile/internal/ssagen.buildssa 9388 -> 9356  (-0.34%)

file                                            before   after    Δ       %
compress/gzip.s                                 8247     8215     -32     -0.388%
net.s                                           266667   266635   -32     -0.012%
crypto/tls.s                                    290324   290238   -86     -0.030%
cmd/compile/internal/syntax.s                   156422   156357   -65     -0.042%
cmd/vendor/github.com/ianlancetaylor/demangle.s 268313   268249   -64     -0.024%
cmd/go/internal/load.s                          122946   122874   -72     -0.059%
cmd/compile/internal/ssa.s                      3551201  3551207  +6      +0.000%
cmd/compile/internal/ssagen.s                   362299   362267   -32     -0.009%
total                                           19725872 19725495 -377    -0.002%

Change-Id: I4cd40b54d8b2da6d1f946e51f16689315a369dca
Reviewed-on: https://go-review.googlesource.com/c/go/+/408474
Run-TryBot: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

cmd/compile: fix unified IR's pointer-shaping

In CL 424734, I implemented pointer shaping for unified IR. Evidently
though, we didn't have any test cases that check that uses of
pointer-shaped expressions were handled correctly.

In the reported test case, the struct field "children items[*node[T]]"
gets shaped to "children items[go.shape.*uint8]" (underlying type
"[]go.shape.*uint8"); and so the expression "n.children[i]" has type
"go.shape.*uint8" and the ".items" field selection expression fails.

The fix implemented in this CL is that any expression of derived type
now gets an explicit "reshape" operation applied to it, to ensure it
has the appropriate type for its context. E.g., the "n.children[i]"
OINDEX expression above gets "reshaped" from "go.shape.*uint8" to
"*node[go.shape.int]", allowing the field selection to succeed.

This CL also adds a "-d=reshape" compiler debugging flag, because I
anticipate debugging reshaping operations will be something to come up
again in the future.

Fixes #54535.

Change-Id: Id847bd8f51300d2491d679505ee4d2e974ca972a
Reviewed-on: https://go-review.googlesource.com/c/go/+/424936
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: hopehook <hopehook@qq.com>
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cmd/compile: fix "expression has untyped type" ICE in generic code

During walk, we sometimes desugar OEQ nodes into multiple "untyped
bool" expressions, and then use typecheck.Conv to convert back to the
original OEQ node's type.

However, typecheck.Conv had a short-circuit path that if the type is
already identical to the target type according to types.Identical,
then we skipped the conversion. This short-circuit is normally fine;
but with generic code and shape types, it considers "untyped bool" and
"go.shape.bool" to be identical types. And we could end up leaving an
expression of "untyped bool", which then fails an internal consistency
check later.

The simple fix is to change Conv to use types.IdenticalStrict, so that
we ensure "untyped bool" gets converted to "go.shape.bool". And for
good measure, make the same change to ConvNop.

This issue was discovered and reported against unified IR, but the
issue was latent within the non-unified frontend too.

Fixes #54537.

Change-Id: I7559a346b063349b35749e8a2da704be18e51654
Reviewed-on: https://go-review.googlesource.com/c/go/+/424937
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Reviewed-by: David Chase <drchase@google.com>

cmd/compile: fix reflect naming of local generic types

To disambiguate local types, we append a "·N" suffix to their name and
then trim it off again when producing their runtime type descriptors.

However, if a local type is generic, then we were further appending
the type arguments after this suffix, and the code in types/fmt.go
responsible for trimming didn't know to handle this.

We could extend the types/fmt.go code to look for the "·N" suffix
elsewhere in the type name, but this is risky because it could
legitimately (albeit unlikely) appear in struct field tags.

Instead, the most robust solution is to just change the mangling logic
to keep the "·N" suffix at the end, where types/fmt.go can easily and
reliably trim it.

Note: the "·N" suffix is still visible within the type arguments
list (e.g., the "·3" suffixes in nested.out), because we currently use
the link strings in the type arguments list.

Fixes #54456.

Change-Id: Ie9beaf7e5330982f539bff57b8d48868a3674a37
Reviewed-on: https://go-review.googlesource.com/c/go/+/424901
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Reviewed-by: Than McIntosh <thanm@google.com>

cmd/compile: restore test/nested.go test cases

When handling a type declaration like:

```
type B A
```

unified IR has been writing out that B's underlying type is A, rather
than the underlying type of A.

This is a bit awkward to implement and adds complexity to importers,
who need to handle resolving the underlying type themselves. But it
was necessary to handle when A was declared like:

```
//go:notinheap
type A int
```

Because we expected A's not-in-heap'ness to be conferred to B, which
required knowing that A was on the path from B to its actual
underlying type int.

However, since #46731 was accepted, we no longer need to support this
case. Instead we can write out B's actual underlying type.

One stumbling point though is the existing code for exporting
interfaces doesn't work for the underlying type of `comparable`, which
is now needed to implement `type C comparable`. As a bit of a hack, we
we instead export its underlying type as `interface{ comparable }`.

Fixes #54512.

Change-Id: I0fb892068d656f1e87bb8ef97da27756051126d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/424854
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Reviewed-by: David Chase <drchase@google.com>

time: fix Parse for time zones

The hours, minutes, and seconds fields for time zones
should not have any plus or minus signs.
Use getnum instead of atoi since the latter implicitly
handles leading signs, while the former does not.

Fixes #54570

Change-Id: If9600170af3af999739c27d81958e3649946913a
Reviewed-on: https://go-review.googlesource.com/c/go/+/425038
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Reviewed-by: Rob Pike <r@golang.org>

time: fix Parse for empty seconds

The error return value of the seconds field is overwritten
and not checked in the presence of a fractional second.
Perform an explicit check for errors.

Fixes #54569

Change-Id: I1204c8bdcd5a5a09b773d9e44748141ed1e5cb20
Reviewed-on: https://go-review.googlesource.com/c/go/+/425036
Reviewed-by: Ian Lance Taylor <iant@google.com>
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Reviewed-by: Rob Pike <r@golang.org>

time: fix Parse to ignore extra sub-nanosecond digits

This modifies the code to match the comment such that
the behavior truly is identical to stdSecond case.
Also, it modifies the behavior to match the documented
behavior where:

    Fractional seconds are truncated to nanosecond precision.

Fixes #54567
Updates #48685

Change-Id: Ie64549e4372ab51624c105ad8ab4cc99b9b5a0b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/425037
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runtime: move traceStackTable.lock to the system stack

This lock is acquired under trace.lock, which as of CL 418956
(6c2e327e35b) must be acquired on the system stack, so this lock must
be, too.

Fixes #54553.

Change-Id: I4fb0c0c2dfc3cb94b76673e842ad416305a31238
Reviewed-on: https://go-review.googlesource.com/c/go/+/425097
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cmd/internal/obj/arm64: remove the transition from $0 to ZR

Previously we convert $0 to the ZR register for some reasons, which causes
two problems:
1. Confusion, the special case of the ZR register needs to be considered
when dealing with constants. For encoding, some places we encode ZR, and
some places we encode $0, although we have converted $0 to ZR.
2. Unexpected instruction format. All instructions that support ZR register
operands can be replaced by $0.

This patch removes this conversion. Note that this patch may cause previously
unintendedly supported instruction formats to no longer be supported.

Change-Id: I3d8d2c06711b7614a38191397da7776417f1861c
Reviewed-on: https://go-review.googlesource.com/c/go/+/404316
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

cmd/compile/internal/ssa: optimize memory moving on arm64

This CL optimizes memory moving with LDP and STP on arm64.

Benchmarks:
name              old time/op  new time/op  delta
ClearFat7-160     1.08ns ± 0%  0.95ns ± 0%  -11.41%  (p=0.008 n=5+5)
ClearFat8-160     0.84ns ± 0%  0.84ns ± 0%   -0.95%  (p=0.008 n=5+5)
ClearFat11-160    1.08ns ± 0%  0.95ns ± 0%  -11.46%  (p=0.008 n=5+5)
ClearFat12-160    0.95ns ± 0%  0.95ns ± 0%     ~     (p=0.063 n=4+5)
ClearFat13-160    1.08ns ± 0%  0.95ns ± 0%  -11.45%  (p=0.008 n=5+5)
ClearFat14-160    1.08ns ± 0%  0.95ns ± 0%  -11.47%  (p=0.008 n=5+5)
ClearFat15-160    1.24ns ± 0%  0.95ns ± 0%  -22.98%  (p=0.029 n=4+4)
ClearFat16-160    0.84ns ± 0%  0.83ns ± 0%   -0.11%  (p=0.008 n=5+5)
ClearFat24-160    2.15ns ± 0%  2.15ns ± 0%     ~     (all equal)
ClearFat32-160    2.86ns ± 0%  2.86ns ± 0%     ~     (p=0.333 n=5+4)
ClearFat40-160    2.15ns ± 0%  2.15ns ± 0%     ~     (all equal)
ClearFat48-160    3.32ns ± 1%  3.31ns ± 1%     ~     (p=0.690 n=5+5)
ClearFat56-160    2.15ns ± 0%  2.15ns ± 0%     ~     (all equal)
ClearFat64-160    3.25ns ± 1%  3.26ns ± 1%     ~     (p=0.841 n=5+5)
ClearFat72-160    2.22ns ± 0%  2.22ns ± 0%     ~     (p=0.444 n=5+5)
ClearFat128-160   4.03ns ± 0%  4.04ns ± 0%   +0.32%  (p=0.008 n=5+5)
ClearFat256-160   6.44ns ± 0%  6.44ns ± 0%   +0.08%  (p=0.016 n=4+5)
ClearFat512-160   12.2ns ± 0%  12.2ns ± 0%   +0.13%  (p=0.008 n=5+5)
ClearFat1024-160  24.3ns ± 0%  24.3ns ± 0%     ~     (p=0.167 n=5+5)
ClearFat1032-160  24.5ns ± 0%  24.5ns ± 0%     ~     (p=0.238 n=4+5)
ClearFat1040-160  29.2ns ± 0%  29.3ns ± 0%   +0.34%  (p=0.008 n=5+5)
CopyFat7-160      1.43ns ± 0%  1.07ns ± 0%  -24.97%  (p=0.008 n=5+5)
CopyFat8-160      0.89ns ± 0%  0.89ns ± 0%     ~     (p=0.238 n=5+5)
CopyFat11-160     1.43ns ± 0%  1.07ns ± 0%  -24.97%  (p=0.008 n=5+5)
CopyFat12-160     1.07ns ± 0%  1.07ns ± 0%     ~     (p=0.238 n=5+4)
CopyFat13-160     1.43ns ± 0%  1.07ns ± 0%     ~     (p=0.079 n=4+5)
CopyFat14-160     1.43ns ± 0%  1.07ns ± 0%  -24.95%  (p=0.008 n=5+5)
CopyFat15-160     1.79ns ± 0%  1.07ns ± 0%     ~     (p=0.079 n=4+5)
CopyFat16-160     1.07ns ± 0%  1.07ns ± 0%     ~     (p=0.444 n=5+5)
CopyFat24-160     1.84ns ± 2%  1.67ns ± 0%   -9.28%  (p=0.008 n=5+5)
CopyFat32-160     3.22ns ± 0%  2.92ns ± 0%   -9.40%  (p=0.008 n=5+5)
CopyFat64-160     3.64ns ± 0%  3.57ns ± 0%   -1.96%  (p=0.008 n=5+5)
CopyFat72-160     3.56ns ± 0%  3.11ns ± 0%  -12.89%  (p=0.008 n=5+5)
CopyFat128-160    5.06ns ± 0%  5.06ns ± 0%   +0.04%  (p=0.048 n=5+5)
CopyFat256-160    9.13ns ± 0%  9.13ns ± 0%     ~     (p=0.659 n=5+5)
CopyFat512-160    17.4ns ± 0%  17.4ns ± 0%     ~     (p=0.167 n=5+5)
CopyFat520-160    17.2ns ± 0%  17.3ns ± 0%   +0.37%  (p=0.008 n=5+5)
CopyFat1024-160   34.1ns ± 0%  34.0ns ± 0%     ~     (p=0.127 n=5+5)
CopyFat1032-160   80.9ns ± 0%  34.2ns ± 0%  -57.74%  (p=0.008 n=5+5)
CopyFat1040-160   94.4ns ± 0%  41.7ns ± 0%  -55.78%  (p=0.016 n=5+4)

Change-Id: I14186f9f82b0ecf8b6c02191dc5da566b9a21e6c
Reviewed-on: https://go-review.googlesource.com/c/go/+/421654
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

encoding/json: rely on utf8.AppendRune

Change-Id: I50e5609ff9c5f2b216b93cec7fb5214d196cae90
Reviewed-on: https://go-review.googlesource.com/c/go/+/412537
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

internal/poll: rely on utf8.AppendRune

This is both simpler and more performant.

Change-Id: I398de29230e578fb7caf1765df7b8fe84d4e8876
Reviewed-on: https://go-review.googlesource.com/c/go/+/412336
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@google.com>

net: turn off dns compression for go resolver queries

We don't need compression enabled here, because we only set one question in the dns message. So there is nothing to compress. Also it reduces 8 allocs per LookupHost.

Change-Id: I0968f837011daf6d7a7b22d9af4a8cc5b2878f4c
GitHub-Last-Rev: 7eb3362bcaa86f47c9d975375b54c7177e8dd15e
GitHub-Pull-Request: golang/go#54576
Reviewed-on: https://go-review.googlesource.com/c/go/+/425043
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>

cmd/compile: fix missing typecheck when rewriting abi.FuncPCABIxxx

Discover when running "go test -run=TestNewOSProc0 -gcflags=-d=checkptr"

Change-Id: I988da56fd3122a21673e86d7dd327ed05914ab72
Reviewed-on: https://go-review.googlesource.com/c/go/+/425040
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

cmd/compile: split Muluhilo op on ARM64

On ARM64 we use two separate instructions to compute the hi and lo
results of a 64x64->128 multiplication. Lower to two separate ops
so if only one result is needed we can deadcode the other.

Fixes #54607.

Change-Id: Ib023e77eb2b2b0bcf467b45471cb8a294bce6f90
Reviewed-on: https://go-review.googlesource.com/c/go/+/425101
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

net/http/cookiejar: remove duplicate words from comments

Change-Id: Id44f587199683fd8018865af1c2442f9f74e0dad
GitHub-Last-Rev: 35b1ab88677586c79918d363f22e05bc0c3c6479
GitHub-Pull-Request: golang/go#54495
Reviewed-on: https://go-review.googlesource.com/c/go/+/424434
Reviewed-by: hopehook <hopehook@qq.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: hopehook <hopehook@qq.com>
Reviewed-by: Joedian Reid <joedian@golang.org>

net/http: skip Get flakes in TestClientTimeout tests on windows/arm4

There is already a skip in case of a later failure in the same test on
these platforms. Skip the failure if it occurs earlier too.

For #43120.

Change-Id: Id530370caa6a7df8cae593f6fdcb66871b86b125
Reviewed-on: https://go-review.googlesource.com/c/go/+/425096
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
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Reviewed-by: Damien Neil <dneil@google.com>

cmd/compile: issue VarDef only for pointer-ful types

Use OpVarDef only when the variable being defined has pointers in it.
VarDef markers are only used for liveness analysis, and that only
runs on pointer-ful variables.

Fixes #53810

Change-Id: I09b0ef7ed31e72528916fe79325f80bbe69ff9b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/419320
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>

cmd/compile: remove OVARDEF and OVARLIVE

Neither are currently used. These concepts only need to exist
in the ssa backend (as ssa.OpVarDef and ssa.OpVarLive).

Change-Id: I8d6bd14aa7967b2156e5e9a103b95146e5552f36
Reviewed-on: https://go-review.googlesource.com/c/go/+/419319
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>

cmd/compile: rip out support for OVARKILL from compiler frontend

Change-Id: I2c5b1064084bade68aaa065cf74dca6886fb752f
Reviewed-on: https://go-review.googlesource.com/c/go/+/419236
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: David Chase <drchase@google.com>

runtime: don't race cmd.Wait and cmd.StdoutPipe read

os/exec.Cmd.Wait closes the read end of os/exec.Cmd.StdoutPipe, meaning
that io.ReadAll can return fs.ErrClosed if the child exits too early,
allowing Wait to complete. The StdoutPipe docs already note this sharp
edge.

Move cmd.Wait until after we finish waiting on stdout. If the child
crashes for some reason, the write end of the pipe will implicitly close
causing io.ReadAll to return as well, so we won't get stuck.

Fixes #52725.

Change-Id: Ifae5745d86206879af2f1523a664236972e07252
Reviewed-on: https://go-review.googlesource.com/c/go/+/420597
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

image/gif: avoid decoding past the first frame in decode()

The existing decode() method offers the ability to keep just one
frame of the GIF image, however it will read and decompress all
subsequent frames regardless.

Fixes #41142

Change-Id: I0c3c11f9c11cd487b6c365e9a8b98e617d555db0
GitHub-Last-Rev: 03ebc8ee7bb19ee80c62d0c935b783d7bc75c2e9
GitHub-Pull-Request: golang/go#46813
Reviewed-on: https://go-review.googlesource.com/c/go/+/329329
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
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Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Paul Tyng <paul@paultyng.net>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Nigel Tao (INACTIVE; USE @golang.org INSTEAD) <nigeltao@google.com>

internal/xcoff: better handling of malformed symbol tables

Check for malformed data when reading the number of aux
symbols associated with a symbol table entry.

Fixes #54584.

Change-Id: Ic2a8d4d6a1d481d585a065b8182de86294c3d3d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/425049
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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go/token: make mutex locking in unpack cheaper

I was profiling the cpu usage of go/printer's only benchmark,
and found that token.File.Unpack was one of the top offenders.

It was mainly the deferred unlock that took a big chunk of time,
and to my surprise, reoving the use of defer helped significantly:

name      old time/op    new time/op    delta
Print-16    5.61ms ± 2%    5.38ms ± 1%  -4.04%  (p=0.000 n=10+8)

name      old speed      new speed      delta
Print-16  9.27MB/s ± 2%  9.64MB/s ± 1%  +4.03%  (p=0.000 n=9+8)

name      old alloc/op   new alloc/op   delta
Print-16     332kB ± 0%     332kB ± 0%    ~     (p=0.363 n=10+10)

name      old allocs/op  new allocs/op  delta
Print-16     3.45k ± 0%     3.45k ± 0%    ~     (all equal)

It seems like #38471 is to blame, as the defer prevents Unlock from
being inlined. Add a TODO as a reminder to come back here once the
compiler issue is fixed.

Change-Id: I5a1c6d36a8e8357435a305a1bc0970ee0358b08a
Reviewed-on: https://go-review.googlesource.com/c/go/+/424920
Reviewed-by: Alan Donovan <adonovan@google.com>
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Reviewed-by: Bryan Mills <bcmills@google.com>
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internal/saferio: avoid returning io.EOF from ReadData if data was read

ReadData follows the error semantics of io.ReadFull for small sizes,
it should do so as well for large sizes.

Change-Id: I6a11b00d903ac5332e1dda074473790dcf21f32a
Reviewed-on: https://go-review.googlesource.com/c/go/+/424919
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>

misc/cgo/test: disable setgid tests with musl

We don't have a good musl detection mechanism, so we detect Alpine (the
most common user of musl) instead.

For #39857.
For #19938.

Change-Id: I2fa39248682aed75884476374fe2212be4427347
Reviewed-on: https://go-review.googlesource.com/c/go/+/425001
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
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debug/buildinfo: add regression tests for different buildmodes

Updates #48187

Change-Id: I2364f248520e77c2e3a4832b9769b52e7aa62f73
Reviewed-on: https://go-review.googlesource.com/c/go/+/357569
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Reviewed-by: Ian Lance Taylor <iant@google.com>
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text/template: compare reflect.Value instances differently

To avoid false positives from the reflectvaluecompare checker #43993

Use v.IsValid() instead of

var zero reflect.Value
v != zero

Also avoid comparing directly with the singleton reflect.Value
representing a missing value. Detect the missing value by type instead.

Change-Id: I3a00d63cf61c077e7c7ae816474aa1f032be325b
Reviewed-on: https://go-review.googlesource.com/c/go/+/308769
Reviewed-by: Cherry Mui <cherryyz@google.com>
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cmd/pprof: fix addr calculation for Windows

This makes it possible to use `disasm` with ASLR windows binaries.

For #46639

Change-Id: I08aff38dc0b33fdfb07e0206766db066e33207d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/416976
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Damien Neil <dneil@google.com>
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runtime/pprof: add memory mapping info for Windows

Fixes #43296

Change-Id: Ib277c2e82c95f71a7a9b7fe1b22215ead7a54a88
Reviewed-on: https://go-review.googlesource.com/c/go/+/416975
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>

misc/cgo/testcarchive: permit SIGQUIT for TestSignalForwardingExternal

Occasionally the signal will be sent to a Go thread, which will cause
the program to exit with SIGQUIT rather than SIGSEGV.

Add TestSignalForwardingGo to test the case where the signal is
expected to be delivered to a Go thread.

This is a roll forward of CL 419014 which was rolled back in CL 424954.
This CL differs from 419014 in that it skips TestSignalForwardingGo
on darwin-amd64.

Fixes #53907

Change-Id: I5df3fd610c068df3bd48d9b3d7a9379248b97999
Reviewed-on: https://go-review.googlesource.com/c/go/+/425002
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

debug/pe: fetch section size directly in (*Section).Data

Change-Id: Idc1f8b3fb6b4b2fdcc6dade048cc14c53715319f
Reviewed-on: https://go-review.googlesource.com/c/go/+/424197
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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go/internal/gcimporter: use saferio to read indexed data

Avoid allocating large amounts of memory for corrupt input.

No test case because the problem can only happen for invalid data.
Let the fuzzer find cases like this.

Fixes #53787

Change-Id: I1b75a4c000b8d1112110309ec44b0ba9b4638d71
Reviewed-on: https://go-review.googlesource.com/c/go/+/416861
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debug/plan9obj: use saferio to read section data

Avoid allocating large amounts of memory for corrupt input.

No test case because the problem can only happen for invalid data.
Let the fuzzer find cases like this.

Fixes #52521

Change-Id: I6a046f2e28e1255cf773ce135c5bb2b967ef43e9
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bytes, strings: s/after/before/ in CutSuffix

This follows on CL 407176 which added this function (in both
packages). This CL makes it consistent with the Cut function,
which uses “before” and “after” in return variable names.

Change-Id: Id4345d2fe0f50bf301a880803e87bf356986b518
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runtime/pprof: check Getrusage return value in addMaxRSS

Depending on the implementation of the getrusage syscall/function, the
value of rusage.Maxrss may be undefined in case of an error. Thus, only
report MaxRSS in case of no error.

Change-Id: I7572ccc53c49eb460e53bded3eb41736eed8d2ed
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runtime/pprof: report MaxRSS on windows

Use GetProcessMemoryInfo to report MaxRSS in memory profiles on windows.

Change-Id: I4ac5fe58961b1d5da8a5c1caa8a6e3d0a3281837
Reviewed-on: https://go-review.googlesource.com/c/go/+/424414
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go/types: match types2 errors for incorrect method receiver count

Use "method has no receiver" and "method has multiple receivers"
in error messages for invalid receiver counts, matching the
corresponding types2 errors.

For #54511.

Change-Id: I96fc99440d6206c74e9416069db052234baa8248
Reviewed-on: https://go-review.googlesource.com/c/go/+/424934
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

go/types: match types2 errors for missing index expressions

Use "middle" and "final" rather than "2nd" and "3rd" in error messages
for invalid slice expressions. This is the original compiler error
message and many tests check for this specific message.

For #54511.

Change-Id: I86eb739aa7218b7f393fab1ab402732cb9e9a1f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/424906
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

go/types: match types2 error for invalid map key

Use "invalid" rather than "incomparable" in error message for map key
types that are not comparable. This is the original compiler error
message and many tests check for this specific message. The type
checker does provide an additional explanation if the reason for
the error is not obvious (e.g. for type parameters).

For #54511.

Change-Id: Idb76c48b4dfbfd66a7deac728a552e07f14e06d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/424905
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

go/parser: match const/var decl parsing of syntax package

Use same approach to parsing const and var declarations
as the syntax package. Specifically, don't complain if
the first const specification in a const declaration
doesn't have a type and initialization expression. This
removes some duplicate errors when combined with the
type checker.

Adjust corresponding type checker tests accordingly.

For #54511.

Change-Id: I96702eba51dda6b581dad44577a7f93e4c02c857
Reviewed-on: https://go-review.googlesource.com/c/go/+/424904
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Revert "misc/cgo/testcarchive: permit SIGQUIT for TestSignalForwardingExternal"

This reverts CL 419014.

Reason for revert: broke darwin-amd64 builders

Change-Id: I77838e696a55c415d322ebb9846503de25b546d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/424954
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runtime: fix a typo in comment of netpollblock()

Change-Id: Ia00acf248f3498d75e2451548f82d3c57cfed06f
Reviewed-on: https://go-review.googlesource.com/c/go/+/424995
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go/parser: fix spelling in error message

Make spelling consistent with uses in other error messages.

Change-Id: I584cd22413842fb8bae1632ed34c8b0e7ef163cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/424902
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

go/types: remove machinery to select parsing mode (cleanup)

All code may be generic. Remove machinery to select parsing
mode (generic vs non-generic) since the parser doesn't support
this anymore. Adjust tests to more closely match corresponding
types2 code.

Change-Id: Id2398afe64d58714974ec96656fdf67c02ff5d04
Reviewed-on: https://go-review.googlesource.com/c/go/+/424900
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go/parser: remove (internal) ability to disable generic code

Generics are part of the language now; there's no need anymore
to switch back to a syntax without generics. Remove the associated
machinery and adjust short tests accordingly.

Change-Id: I6b16c5c75fd9354ee87e3b9bee110f49f514565a
Reviewed-on: https://go-review.googlesource.com/c/go/+/424857
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go/parser: remove import path string syntax checking

The validity of an import path string is checked by the type checker
(and possibly other tools); it doesn't need to be done by the parser.
Remove the respective code and tests.

Also, adjust a corresponding go/types test which resolves a TODO.

For #54511.

Change-Id: Id1fc80df4e3e83be3ef123da3946ccb8f759779f
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cmd/compile/internal/types2: match go/types for "..." related error msg

For #54511.

Change-Id: I571680dfc25d7b7198e84e11bd311ab8b24d72d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/424818
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cmd/compile/internal/types2: use go/types/testdata/examples tests

Since the examples tests are now identical between the two type checkers,
remove the local copy of the examples tests and (for now) use the tests
in go/types/testdata/examples instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).

For #54511.

Change-Id: Ibd8599d09e781b2219a23114b4b2049757971181
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go/types: remove TODO in testdata/examples/types.go

Follow-up on CL 424674. With this change, the files in
testdata/examples are identical to the corresponding
files for types2.

For #54511.

Change-Id: Ic61c089bbf61492094e31057ad2635803f50a30d
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go/parser: disallow parenthesizing embedded types in structs

This was never permitted in Go but the flexibility to do so
was introduced through the generics prototype code where we
experimented with parentheses to enclose type parameters.
Restore original (pre-generics) behavior.

Fixes #51655.

Change-Id: Ia7a4b2e393e0214a70e840c8663cf4474c5c754b
Reviewed-on: https://go-review.googlesource.com/c/go/+/424694
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runtime/internal/atomic: remove double-check in kernelcas on linux/arm

Older kernels which require the double check of the __kuser_cmpxchg
result are no longer supported as of Go 1.18 which requires at least
Linux 2.6.32.

For #45964

Change-Id: Ic3d6691bf006353ac51b9d43e742d970e3d4e961
Reviewed-on: https://go-review.googlesource.com/c/go/+/424556
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io: add OffsetWriter, NewOffsetWriter

Offsetwriter refers to the design of SectionReader and removes
the section parameter n.

Since the size of the written data is determined by the user,
we cannot know where the end offset of the original data is.
The offset of SeekEnd is not valid in Seek method.

Fixes #45899.

Change-Id: I9d9445aecfa0dd4fc5168f2f65e1e3055c201b45
Reviewed-on: https://go-review.googlesource.com/c/go/+/406776
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.github/ISSUE_TEMPLATE: add issue template for Go vulnerability management

Change-Id: Ia8bdd7909e94f3ab7248e88f0947db85ac744d79
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unicode/utf16: add AppendRune

AppendRune appends the UTF-16 encoding of a rune to a []uint16.

    BenchmarkEncodeValidASCII-12                24.61ns 16B 1allocs
    BenchmarkEncodeValidJapaneseChars-12        18.79ns 8B  1allocs
    BenchmarkAppendRuneValidASCII-12            6.826ns 0B  0allocs
    BenchmarkAppendRuneValidJapaneseChars-12    3.547ns 0B  0allocs

The ASCII case is written to be inlineable.

Fixes #51896

Change-Id: I593b1029f603297ef6e80e036f2fee2a0938d38d
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go/printer: rename printPos to setPos

Follow-up on feedback in CL 412557.

Change-Id: I5a693efccade97a62ab880c6e1b9e50cb597c293
Reviewed-on: https://go-review.googlesource.com/c/go/+/424814
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
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strings: reduce allocation for byteReplacer

Though it increases the execution time, the function is already quite
fast for most users, the allocation is much more important.

name                       old time/op    new time/op    delta
ByteReplacerWriteString-8    1.23µs ± 0%    2.16µs ± 1%   +75.31%  (p=0.000 n=10+10)

name                       old alloc/op   new alloc/op   delta
ByteReplacerWriteString-8    2.69kB ± 0%    0.00kB       -100.00%  (p=0.000 n=10+10)

name                       old allocs/op  new allocs/op  delta
ByteReplacerWriteString-8      1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)

Change-Id: I6a36df5fcb8e11ef27e6c7b252aa88e869592f3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/424136
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syscall: remove cloexecSocket fallback path

Support for Linux kernel versions requiring the fallback to CloseOnExec
was dropped from recent Go versions. The minimum Linux kernel version is
2.6.32 as of Go 1.18. The SOCK_CLOEXEC flag for the socket syscall is
supported since kernel version 2.6.27.

Follows a similar change for net.sysSocket in CL 403634.

For #45964

Change-Id: I8b6311f07c4ed7900a9af3ecb2e146c49db08665
Reviewed-on: https://go-review.googlesource.com/c/go/+/422374
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strings: speed up ToUpper()/ToLower() by batch writing data with Builder

Updates #52371
Updates CL 423874

name                                                                    old time/op    new time/op    delta
ToUpper/#00-10                                                            2.85ns ± 0%    2.81ns ± 0%   -1.31%  (p=0.000 n=10+10)
ToUpper/ONLYUPPER-10                                                      12.7ns ± 0%    12.5ns ± 0%   -1.35%  (p=0.000 n=10+10)
ToUpper/abc-10                                                            20.9ns ± 1%    20.1ns ± 1%   -3.92%  (p=0.000 n=8+10)
ToUpper/AbC123-10                                                         26.9ns ± 1%    28.5ns ± 0%   +5.78%  (p=0.000 n=9+9)
ToUpper/azAZ09_-10                                                        27.4ns ± 1%    24.5ns ± 0%  -10.82%  (p=0.000 n=9+9)
ToUpper/longStrinGwitHmixofsmaLLandcAps-10                                95.9ns ± 1%   100.3ns ± 0%   +4.52%  (p=0.000 n=9+10)
ToUpper/RENAN_BASTOS_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10     188ns ± 0%     121ns ± 0%  -35.52%  (p=0.000 n=9+10)
ToUpper/longɐstringɐwithɐnonasciiⱯchars-10                                 168ns ± 0%     164ns ± 0%   -2.02%  (p=0.000 n=8+10)
ToUpper/ɐɐɐɐɐ-10                                                           134ns ± 0%     132ns ± 0%   -1.59%  (p=0.000 n=9+10)
ToUpper/a\u0080\U0010ffff-10                                              67.6ns ± 0%    66.4ns ± 0%   -1.73%  (p=0.000 n=10+10)
ToLower/#00-10                                                            2.87ns ± 4%    2.83ns ± 0%   -1.46%  (p=0.004 n=9+9)
ToLower/abc-10                                                            6.35ns ± 0%    6.29ns ± 0%   -0.98%  (p=0.000 n=9+9)
ToLower/AbC123-10                                                         25.6ns ± 1%    28.1ns ± 1%   +9.81%  (p=0.000 n=10+10)
ToLower/azAZ09_-10                                                        29.9ns ± 1%    30.1ns ± 1%   +0.64%  (p=0.023 n=9+10)
ToLower/longStrinGwitHmixofsmaLLandcAps-10                                96.7ns ± 1%    73.0ns ± 0%  -24.50%  (p=0.000 n=10+10)
ToLower/renan_bastos_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10     177ns ± 0%     118ns ± 0%  -33.61%  (p=0.000 n=7+8)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-10                                 159ns ± 1%     158ns ± 0%   -0.97%  (p=0.000 n=8+10)
ToLower/ⱭⱭⱭⱭⱭ-10                                                           125ns ± 1%     123ns ± 1%   -1.67%  (p=0.000 n=9+9)
ToLower/A\u0080\U0010ffff-10                                              68.4ns ± 1%    67.1ns ± 0%   -1.95%  (p=0.000 n=9+9)

name                                                                    old alloc/op   new alloc/op   delta
ToUpper/#00-10                                                             0.00B          0.00B          ~     (all equal)
ToUpper/ONLYUPPER-10                                                       0.00B          0.00B          ~     (all equal)
ToUpper/abc-10                                                             3.00B ± 0%     3.00B ± 0%     ~     (all equal)
ToUpper/AbC123-10                                                          8.00B ± 0%     8.00B ± 0%     ~     (all equal)
ToUpper/azAZ09_-10                                                         8.00B ± 0%     8.00B ± 0%     ~     (all equal)
ToUpper/longStrinGwitHmixofsmaLLandcAps-10                                 32.0B ± 0%     32.0B ± 0%     ~     (all equal)
ToUpper/RENAN_BASTOS_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10     64.0B ± 0%     64.0B ± 0%     ~     (all equal)
ToUpper/longɐstringɐwithɐnonasciiⱯchars-10                                 48.0B ± 0%     48.0B ± 0%     ~     (all equal)
ToUpper/ɐɐɐɐɐ-10                                                           48.0B ± 0%     48.0B ± 0%     ~     (all equal)
ToUpper/a\u0080\U0010ffff-10                                               16.0B ± 0%     16.0B ± 0%     ~     (all equal)
ToLower/#00-10                                                             0.00B          0.00B          ~     (all equal)
ToLower/abc-10                                                             0.00B          0.00B          ~     (all equal)
ToLower/AbC123-10                                                          8.00B ± 0%     8.00B ± 0%     ~     (all equal)
ToLower/azAZ09_-10                                                         8.00B ± 0%     8.00B ± 0%     ~     (all equal)
ToLower/longStrinGwitHmixofsmaLLandcAps-10                                 32.0B ± 0%     32.0B ± 0%     ~     (all equal)
ToLower/renan_bastos_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10     64.0B ± 0%     64.0B ± 0%     ~     (all equal)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-10                                 48.0B ± 0%     48.0B ± 0%     ~     (all equal)
ToLower/ⱭⱭⱭⱭⱭ-10                                                           24.0B ± 0%     24.0B ± 0%     ~     (all equal)
ToLower/A\u0080\U0010ffff-10                                               16.0B ± 0%     16.0B ± 0%     ~     (all equal)

name                                                                    old allocs/op  new allocs/op  delta
ToUpper/#00-10                                                              0.00           0.00          ~     (all equal)
ToUpper/ONLYUPPER-10                                                        0.00           0.00          ~     (all equal)
ToUpper/abc-10                                                              1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/AbC123-10                                                           1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/azAZ09_-10                                                          1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/longStrinGwitHmixofsmaLLandcAps-10                                  1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/RENAN_BASTOS_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10      1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/longɐstringɐwithɐnonasciiⱯchars-10                                  1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToUpper/ɐɐɐɐɐ-10                                                            2.00 ± 0%      2.00 ± 0%     ~     (all equal)
ToUpper/a\u0080\U0010ffff-10                                                1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/#00-10                                                              0.00           0.00          ~     (all equal)
ToLower/abc-10                                                              0.00           0.00          ~     (all equal)
ToLower/AbC123-10                                                           1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/azAZ09_-10                                                          1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/longStrinGwitHmixofsmaLLandcAps-10                                  1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/renan_bastos_93_AOSDAJDJAIDJAIDAJIaidsjjaidijadsjiadjiOOKKO-10      1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-10                                  1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/ⱭⱭⱭⱭⱭ-10                                                            1.00 ± 0%      1.00 ± 0%     ~     (all equal)
ToLower/A\u0080\U0010ffff-10                                                1.00 ± 0%      1.00 ± 0%     ~     (all equal)

Change-Id: Id3998ac4bae054ba3e6cf30545a257d5992b48be
Reviewed-on: https://go-review.googlesource.com/c/go/+/424139
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>

syscall: add new CLONE_ flags for Linux

The constants for these were auto-generated from the C includes
into zerrors_linux* files quite some time ago. The generator is
currently broken, but some new flags need to be added nevertheless.

As the flags won't change and the values are the same for all
architectures, we can just define them statically (as it's already
done in the runtime package):

 - remove the CLONE_* constants from zerrors_linux_*.go;
 - patch mkerrors.sh to not generate CLONE_ constants
   (in case it will be fixed and used in the future);
 - add the constants and some comments about them to exec_linux.go,
   using Linux v5.17 include/uapi/sched.h as the ultimate source.

This adds the following new flags:

 - CLONE_CLEAR_SIGHAND
 - CLONE_INTO_CGROUP
 - CLONE_NEWCGROUP
 - CLONE_NEWTIME
 - CLONE_PIDFD

For #51246.

Change-Id: I0c635723926218bd403d37e113ee4d62194463a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/407574
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joedian Reid <joedian@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>

cmd/compile: add intrinsic for MulUintptr on arm64

This CL adds intrinsic for runtime/internal/math.MulUintptr on arm64

Benchmark         master     ThisCL(ns/op)   delta
MulUintptr/small  0.95ns     0.79ns          -16%
MulUintptr/large  1.31ns     0.95ns          -27.6%

Change-Id: Ic7b453ad502826beffe93ce5531b8ba752312a1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/419556
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Joedian Reid <joedian@golang.org>

runtime: fix formula for computing number of padding bytes

In order to prevent false sharing of cache lines, structs are
padded with some number of bytes. These bytes are unused, serving
only to make the size of the struct a multiple of the size of the
cache line.

The current calculation of how much to pad is an overestimation,
when the struct size is already a multiple of the cache line size
without padding. For these cases, no padding is necessary, and
the size of the inner pad field should be 0. The bug is that the
pad field is sized to a whole 'nother cache line, wasting space.

Here is the current formula that can never return 0:
cpu.CacheLinePadSize - unsafe.Sizeof(myStruct{})%cpu.CacheLinePadSize

This change simply mods that calculation by cpu.CacheLinePadSize,
so that 0 will be returned instead of cpu.CacheLinePadSize.

Change-Id: I26a2b287171bf47a3b9121873b2722f728381b5e
Reviewed-on: https://go-review.googlesource.com/c/go/+/414214
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>

encoding/gob: use saferio to read large buffer

Avoid allocating large amounts of memory for corrupt input.

No test case because the problem can only happen for invalid data.
Let the fuzzer find cases like this.

Fixes #53369

Change-Id: I67c5e75bf181ad84988d6d6da12507df0e6df8e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/413979
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>

runtime: remove pageAlloc.scav padding for atomic field alignment

CL 404096 makes atomic.Int64 8 bytes aligned everywhere.

Change-Id: I5a676f646260d6391bb071f9376cbdb1553e6e6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/424925
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

test: add test that caused gccgo crash

For #23870

Change-Id: I3bbe0f751254d1354a59a88b45e6f944c7a2fb4d
Reviewed-on: https://go-review.googlesource.com/c/go/+/417874
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

test: add test that caused gccgo to crash

For #23868

Change-Id: I07b001836e8d1411609ab84786398a5b575bf8d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/417481
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>

misc/cgo/testcarchive: permit SIGQUIT for TestSignalForwardingExternal

Occasionally the signal will be sent to a Go thread, which will cause
the program to exit with SIGQUIT rather than SIGSEGV.

Add TestSignalForwardingGo to test the case where the signal is
expected to be delivered to a Go thread.

Fixes #53907

Change-Id: Iaefb964c2be4a815c11c507fa89648f8a7740ba9
Reviewed-on: https://go-review.googlesource.com/c/go/+/419014
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>

net: allow single dot in resolv.conf search statement

A single dot in a search statement doesn't affect DNS lookup, so just ignore it and a syntax error.

Fixes #54124

Change-Id: Idd43bd34c5c16af50cba51f0b6e24f992eec6e57
Reviewed-on: https://go-review.googlesource.com/c/go/+/423875
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>