os: skip Root.Chtimes atime check on netbsd, truncate a/mtime on plan9

The NetBSD builder has noatime set on its filesystem.
Skip testing the atime on this builder.

Plan9 has second precision on its atime and mtimes.
Truncate the values passed to Chtimes.

For #72957

Change-Id: I963e2dd34075a9ba025e80641f0b675d5d912188
Reviewed-on: https://go-review.googlesource.com/c/go/+/659356
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

internal/syscall/unix: fix number of params for unlinkat

This reverts the change to Unlinkat done in CL 659415, as it appears
to be wrong.

While at it, let's unify argument formatting for better readability
(and also so those parameters are easier to count).

Change-Id: I092105f85de107e0495afed3cd66c039343250f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/659357
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/syscall/unix: use correct number of params in unlinkat, fchownat

We were calling syscall6 with an incorrect parameter count, omitting
the flags parameter.

Change-Id: Ife606bd57c1e4b899c0340767e9197bbe0aa81a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/659415
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

os: add Root.Readlink

For #67002

Change-Id: I532a5ffc02c7457796540db54fa2f5ddad86e4b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/658995
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

os: add Root.Lchown

For #67002

Change-Id: I1bbf18838a1dd2281a2b6e56fc8a58ef70007adc
Reviewed-on: https://go-review.googlesource.com/c/go/+/649536
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

runtime/race: detect when TestRace fails to run all tests, skip failures

TestRace runs a collection of tests, some of which are expected
to fail with data races. Make TestRace more robust at detecting
when the test run is cut short, such as when a test causes
an unhandled panic.

Skip TestRaceRangeFuncIterator, which contains an unhandled panic.
This test was causing all subsequent tests to not run.

Skip TestNoRaceRangeFuncIterator, which contains an unexpected data race.
This test was not running due to the above failure.

For #72925

Change-Id: Id662375cc498ea25ae308619709768588bf6a2f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/658875
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Damien Neil <dneil@google.com>

go/types, types2: fix silly logic error in commonUnder

Fixes #72936.

Change-Id: I79ed8d559c8565fa960b974f8c1207ee442f4c26
Reviewed-on: https://go-review.googlesource.com/c/go/+/659256
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>

net/http/httputil: don't call WriteHeader after Hijack

CL 637939 changed ReverseProxy to report errors encountered when
copying data on an hijacked connection. This is generally not useful,
and when using the default error handler results in WriteHeader
being called on a hijacked connection.

While this is harmless with standard net/http ResponseWriter
implementations, it can confuse middleware layers.

Fixes #72954

Change-Id: I21f3d3d515e114dc5c298d7dbc3796c505d3c82f
Reviewed-on: https://go-review.googlesource.com/c/go/+/659255
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/compile: remove implicit deref from len(p) where p is ptr-to-array

func f() *[4]int { return nil }
_ = len(f())

should not panic. We evaluate f, but there isn't a dereference
according to the spec (just "arg is evaluated").

Update #72844

Change-Id: Ia32cefc1b7aa091cd1c13016e015842b4d12d5b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/658096
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Keith Randall <khr@google.com>

runtime: in asan mode unregister root regions on free

CL 651755 introduced registration of root regions when allocating
memory. We also need to unregister that memory to avoid the leak
sanitizer accessing unmapped memory.

Issue #67833

Change-Id: I5d403d66e65a8a003492f4d79dad22d416fd8574
Reviewed-on: https://go-review.googlesource.com/c/go/+/659135
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

cmd/internal/obj/riscv: prevent panics on bad branches

Syntactically incorrect branches, such as

BEQ X5, X6, $1
BEQ X5, X6, 31(X10)

cause the assembler to panic, which they shouldn't really do.  It's
better for the user to see a normal error, as reported for other
syntax errors in riscv64 assembly.  The panics also prevent us
from writing negative tests for these sorts of errors.

Here we fix the issue by ensuring we generate a normal error instead
of panicking when the user provides an invalid branch target.  We
also add a couple of negative tests.

Change-Id: I1da568999a75097484b61a01d418f5d4be3e04fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/637316
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>

cmd/internal/obj/riscv: prevent duplicate error reports

The riscv64 Go assembler can output certain errors, ones produced by
instructionsForProg, multiple times.  These errors are guaranteed to
be output at least twice and can appear three or more times if a
rescan is needed to recompute branch addresses.  For example, the
syntactically incorrect instruction

MOV (X10), $1

will generate at least two identical errors

asm: 86076 (asm.s:21524) MOV (X10), $1: unsupported MOV
asm: 86076 (asm.s:21524) MOV (X10), $1: unsupported MOV
asm: assembly failed

In addition to confusing the user, these duplicate errors make it
difficult to write negative tests for certain types of instructions,
e.g., branches, whose duplicate errors are not always identical,
and so not ignored by endtoend_test.go.

We fix the issue by returning from preprocess if any errors have been
generated by the time we reach the end of the rescan loop. One
implication of this change is that validation errors will no longer
be reported if an error is generated earlier in the preprocess stage.
Negative test cases for validation errors are therefore moved to
their own file as the existing riscv64error.s file contains errors
generated by instructionsForProg that will now suppress the
validation errors.

Change-Id: Iffacdbefce28f44970dd5dda44990b822b8a23d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/637315
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

internal/godebugs: fix changed version for winsymlink and winreadlinkvolume to 1.23

https://go.dev/doc/godebug#go-123 documents changes to winsymlink and
winreadlinkvolume in Go 1.23.

This fixes the registered "changed" minor version to Go 1.23,
so that defaults when building a Go 1.22 module are correct.

Fixes #72935

Change-Id: I5d5bf31ca04f9e95208fb0fdaad2232f9db653ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/659035
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

os: add Root.Chtimes

For #67002

Change-Id: I9b10ac30f852052c85d6d21eb1752a9de5474346
Reviewed-on: https://go-review.googlesource.com/c/go/+/649515
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Kirill Kolyshkin <kolyshkin@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

doc: document change in nil-ptr checking behavior

This could bite people during the 1.25 release, so make sure it
has good documentation in the release notes.

Update #72860

Change-Id: Ie9aaa219025a631e81ebc48461555c5fb898f43f
Reviewed-on: https://go-review.googlesource.com/c/go/+/658955
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

bytes,strings: document Fields trimming of leading and trailing characters

Fixes #72841

Change-Id: I46875c61e3147c69da759bf4bf4f0539cbd4f437
Reviewed-on: https://go-review.googlesource.com/c/go/+/658218
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/compile/internal/amd64: disable FIPS 140-3 mode for TestGoAMD64v1

TestGoAMD64v1 modifies the binary, which will make the FIPS 140-3
integrity self-check fail. Disable FIPS 140-3 mode when running the
modified binary.

Change-Id: I6a6a46566a38f8c44f996f6e1155dac5f67c56e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/658915
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

net/http/httputil: document ProxyRequest.SetURL limitations

Fixes #50337

Change-Id: I898ff6352f46f0f9b540b053049c5116e2165827
Reviewed-on: https://go-review.googlesource.com/c/go/+/658536
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

cmd/go/internal/clean: add logging to help debug openbsd flakes

This change adds extra logging in the case where there's an error
removing all the files in the gomodcache using modfetch.RemoveAll.
It logs the names of the files found in GOMODCACHE as well as their
modes. The modes are included because they should all be writable by the
time we call robustio.RemoveAll.

For #68087

Change-Id: Id9ae68bf6a3392baf88ec002d08fed1faf525927
Reviewed-on: https://go-review.googlesource.com/c/go/+/658816
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Matloob <matloob@golang.org>

net/http: add onClose hook to fake net listener

Avoids a race condition: If we set an onClose hook on a conn
created by a listener, then setting the hook can race with
the connection closing.

Change-Id: Ibadead3abbe4335d41f1e2cf84f4696fe98166b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/658655
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Damien Neil <dneil@google.com>

runtime, time: don't use monotonic clock inside synctest bubbles

Don't include a monotonic time in time.Times created inside
a bubble, to avoid the confusion of different Times using
different monotonic clock epochs.

For #67434

goos: darwin
goarch: arm64
pkg: time
cpu: Apple M1 Pro
         │ /tmp/bench.0 │            /tmp/bench.1            │
         │    sec/op    │   sec/op     vs base               │
Since-10    18.42n ± 2%   18.68n ± 1%       ~ (p=0.101 n=10)
Until-10    18.28n ± 2%   18.46n ± 2%  +0.98% (p=0.009 n=10)
geomean     18.35n        18.57n       +1.20%

Change-Id: Iaf1b80d0a4df52139c5b80d4bde4410ef8a49f2f
Reviewed-on: https://go-review.googlesource.com/c/go/+/657415
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>

runtime: add function runtime.cgoSigtramp support on loong64 and enable cgo-traceback testcases

Change-Id: I82f6ebd5636bfa112ad3e25dd9b77d7778469a1f
Reviewed-on: https://go-review.googlesource.com/c/go/+/604176
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>

runtime, runtime/cgo: use libc for sigaction syscalls when cgo is enabled on loong64

This ensures that runtime's signal handlers pass through the TSAN and
MSAN libc interceptors and subsequent calls to the intercepted
sigaction function from C will correctly see them.

Change-Id: I243a70d9dcb6d95a65c8494d5f9f9f09a316c693
Reviewed-on: https://go-review.googlesource.com/c/go/+/654995
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

crypto/tls: fix ECH compatibility

Previously, the code only checked supportedVersions[0] for TLS 1.3
However, Chromium-based
browsers may list TLS 1.3 at different positions, causing ECH failures.
This fix:
    Iterates through supportedVersions to accept connections as long as TLS 1.3 is present.
    Improves ECH compatibility, ensuring Chrome, Edge, and other browsers work properly.

Fixes #71642

Change-Id: I32f4219fb6654d5cc22c7f33497c6142c0acb4f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/648015
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Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>

log/slog: document Logger ignores Handler.Handle errors

Fixes #66579

Change-Id: Ie75378b087763c3e88303df3b3f8d7565003a92f
Reviewed-on: https://go-review.googlesource.com/c/go/+/658515
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

crypto/internal/hpke: propagate hkdf error value

The hkdf operations done in hpke are not expected to fail given that
we control the inputs. However, propagating the error instead of
doesn't hurt and makes the code more robust to future changes.

Change-Id: I168854593a40f67e2cc275e0dedc3b24b8f1480e
Reviewed-on: https://go-review.googlesource.com/c/go/+/658475
Reviewed-by: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>

crypto/internal/hpke: use crypto/hkdf

The hpke package uses public-facing crypto packages except for hkdf,
which uses crypto/internal/hkdf. We already have a public hkdf package,
crypto/hkdf, so use it instead for consistency.

Change-Id: Icf6afde791234dfe24dbfba715c0891f32005ca2
Reviewed-on: https://go-review.googlesource.com/c/go/+/657556
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/go: point tidy errors to correct URL

The `go mod tidy` errors have been pointing to an older URL. This CL
fixes the URL by pointing to the correct URL: https://go.dev/ref/mod.

Fixes #49394

Change-Id: I707dda407ba032db8a55083998002a5ab72033e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/633421
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/buildcfg: expand spinbitmutex platforms

Go 1.24 included the spinbitmutex GOEXPERIMENT for several popular
architectures, based on their native support an atomic primitive (8-bit
exchange) that aided its efficient implementation.

Move towards making the new mutex implementation permanent, so it fully
replaces the two previous (sema- and futex-based "tristate")
implementations.

For #68578

Change-Id: I888a73959df42eb0ec53875309c446675af8f09d
Reviewed-on: https://go-review.googlesource.com/c/go/+/658455
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Rhys Hiltner <rhys.hiltner@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

reflect: document Method(ByName) w.r.t dead code elimination

The behavior is described in src/cmd/link/internal/ld/deadcode.go
but is not otherwise documented. Since the usage of those functions
could have significant caveats (longer builds, larger binaries),
we are informing the user.

Change-Id: I87571dd14aa16d7aac59fe45dfc52cb7c5b956c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/658255
Auto-Submit: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

doc/next: add release note for work package pattern

For #71294
Fixes #50745

Change-Id: Iff05e98ac860a1764d4c59572f9abc3ae8d9c5fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/658495
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
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Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

html/template: document comment stripping

Fixes #28628

Change-Id: I8b68f55f25e62f747d7cc48a490fec7f426f53d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/658115
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>
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runtime: skip TestCgoCallbackPprof on platforms with broken profiling

CL 658035 added TestCgoCallbackPprof, which is consistently failing on
solaris. runtime/pprof maintains a list of platforms where CPU profiling
does not work properly. Since this test requires CPU profiling, skip the
this test on those platforms.

For #72870.
Fixes #72876.

Change-Id: I6a6a636cbf6b16abcbba8771178fe1d001be9d9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/658415
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cmd/internal/obj/loong64: add {V,XV}NEG{B/H/W/V} instructions support

Go asm syntax:
 VNEG{B/H/W/V} VJ, VD
XVNEG{B/H/W/V} XJ, XD

Equivalent platform assembler syntax:
 vneg.{b/h/w/d} vd, vj
xvneg.{b/h/w/d} xd, xj

Change-Id: Ie0a82a434b0ffbcb77425a65b96eff56e030028c
Reviewed-on: https://go-review.googlesource.com/c/go/+/635935
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
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Reviewed-by: David Chase <drchase@google.com>

doc/go_mem: fix grammar issue

In the passage about buffered channels, remove redundant words and match
the wording of the earlier passage about unbuffered channels.

Change-Id: I35d8a3bf4f176c3f69cf5e6a64595e5d1c23e3a1
GitHub-Last-Rev: 1c4c9390a174d1a66797a025e2fdb0bf56239f48
GitHub-Pull-Request: golang/go#72891
Reviewed-on: https://go-review.googlesource.com/c/go/+/657778
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>
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Auto-Submit: Ian Lance Taylor <iant@google.com>
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Auto-Submit: Keith Randall <khr@golang.org>

cmd/compile: intrinsify math/bits.TrailingZeros on riscv64

For riscv64/rva22u64 and above, we can intrinsify math/bits.TrailingZeros
using the CTZ/CTZW machine instructions.

On a StarFive VisionFive 2 with GORISCV64=rva22u64:

                  │   ctz.b.1    │               ctz.b.2               │
                  │    sec/op    │   sec/op     vs base                │
TrailingZeros-4     25.500n ± 0%   8.052n ± 0%  -68.42% (p=0.000 n=10)
TrailingZeros8-4     14.76n ± 0%   10.74n ± 0%  -27.24% (p=0.000 n=10)
TrailingZeros16-4    26.84n ± 0%   10.74n ± 0%  -59.99% (p=0.000 n=10)
TrailingZeros32-4   25.500n ± 0%   8.052n ± 0%  -68.42% (p=0.000 n=10)
TrailingZeros64-4   25.500n ± 0%   8.052n ± 0%  -68.42% (p=0.000 n=10)
geomean              23.09n        9.035n       -60.88%

Change-Id: I71edf2b988acb7a68e797afda4ee66d7a57d587e
Reviewed-on: https://go-review.googlesource.com/c/go/+/652320
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
Reviewed-by: David Chase <drchase@google.com>
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strings: add FuzzReplace test

While reviewing CL 657935 I've notied there a
couple tricky reslices that depends on multiple
things being correct.

Might as well fuzz it.

Change-Id: Id78921bcb252e73a8a06e6deb4c920445a87d525
Reviewed-on: https://go-review.googlesource.com/c/go/+/658075
Reviewed-by: David Chase <drchase@google.com>
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Reviewed-by: Ian Lance Taylor <iant@google.com>

html/template: replace end-of-life link

Fix #65044

Change-Id: I5bf9c1cf2e9d3ae1e4bbb8f2653512c710db370b
Reviewed-on: https://go-review.googlesource.com/c/go/+/555815
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: David Chase <drchase@google.com>
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os: use slices.Clone

Change-Id: I5a3de1b2fe2ebbb6437df5e7cc55e0d8d69c9cd7
Reviewed-on: https://go-review.googlesource.com/c/go/+/657915
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
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runtime: log profile when mutex profile test fails

For #70602

Change-Id: I3f723ebc17ef690d5be7f4f948c9dd1f890196fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/658095
Auto-Submit: Rhys Hiltner <rhys.hiltner@gmail.com>
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cmd/compile: combine negation and word sign extension on riscv64

Use NEGW to produce a negated and sign extended word, rather than doing
the same via two instructions:

   neg     t0, t0
   sext.w  a0, t0

Becomes:

   negw    t0, t0

Change-Id: I824ab25001bd3304bdbd435e7b244fcc036ef212
Reviewed-on: https://go-review.googlesource.com/c/go/+/652319
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Reviewed-by: Cherry Mui <cherryyz@google.com>

cmd/compile/internal/ssa: remove double negation with addition on riscv64

On riscv64, subtraction from a constant is typically implemented as an
ADDI with the negative constant, followed by a negation. However this can
lead to multiple NEG/ADDI/NEG sequences that can be optimised out.

For example, runtime.(*_panic).nextDefer currently contains:

   lbu     t0, 0(t0)
   addi    t0, t0, -8
   neg     t0, t0
   addi    t0, t0, -7
   neg     t0, t0

Which is now optimised to:

   lbu     t0, 0(t0)
   addi    t0, t0, -1

Change-Id: Idf5815e6db2e3705cc4a4811ca9130a064ae3d80
Reviewed-on: https://go-review.googlesource.com/c/go/+/652318
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
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test/codegen: add a test for negation and conversion to int32

Codify the current code generation used on riscv64 in this case.

Change-Id: If4152e3652fc19d0aa28b79dba08abee2486d5ae
Reviewed-on: https://go-review.googlesource.com/c/go/+/652317
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
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Reviewed-by: David Chase <drchase@google.com>
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test/codegen: add riscv64 codegen for arithmetic tests

Codify the current riscv64 code generation for various subtract from
constant and addition/subtraction tests.

Change-Id: I54ad923280a0578a338bc4431fa5bdc0644c4729
Reviewed-on: https://go-review.googlesource.com/c/go/+/652316
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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test/codegen: add riscv64/rva23u64 specifiers to existing tests

Tests that exist for riscv64/rva22u64 should also be applied to
riscv64/rva23u64.

Change-Id: Ia529fdf0ac55b8bcb3dcd24fa80efef2351f3842
Reviewed-on: https://go-review.googlesource.com/c/go/+/652315
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Reviewed-by: David Chase <drchase@google.com>

internal/runtime/atomic: add Xchg8 for s390x and wasm

This makes the single-byte atomic.Xchg8 operation available on all
GOARCHes, including those without direct / single-instruction support.

Fixes #69735

Change-Id: Icb6aff8f907257db81ea440dc4d29f96b3cff6c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/657936
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
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Auto-Submit: Rhys Hiltner <rhys.hiltner@gmail.com>
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cmd/go: enable fuzz testing on OpenBSD

This change provides support for -fuzz flag on OpenBSD. According to #46554 the flag was unsupported on some OSes due to lack of proper testing.

Fixes: #60491
Change-Id: I49835131d3ee23f6482583b518b9c5c224fc4efe
GitHub-Last-Rev: f697a3c0f2dc36cc3c96c0336281c5e2440f7a1a
GitHub-Pull-Request: golang/go#60520
Reviewed-on: https://go-review.googlesource.com/c/go/+/499335
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Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

debug/elf: add riscv attributes definitions

This CL adds `riscv.attributes` related ELF section header
type and program header type according to
[RISC-V ELF Specification](https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/v1.0/riscv-abi.pdf)

Also an riscv64/linux testcase binary built from:

```
gcc -march=rv64g -no-pie -o gcc-riscv64-linux-exec hello.c
strip gcc-riscv64-linux-exec
```

Fixes #72843

Change-Id: I7710a0516f69141c0efaba71dd997f05b4c88421
Reviewed-on: https://go-review.googlesource.com/c/go/+/657515
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Reviewed-by: Ian Lance Taylor <iant@google.com>

time: optimize quote using byte(c) for ASCII

Since c < runeSelf && c >= ' ' (i.e., 32 <= c < 128), using buf = append(buf, byte(c)) instead of buf = append(buf, string(c)...) is a better choice, as it provides better performance.

Change-Id: Ic0ab25c71634a1814267f4d85be2ebd8a3d44676
GitHub-Last-Rev: 5445b547712bbfc77a5c17d76194291c22eb4a05
GitHub-Pull-Request: golang/go#72820
Reviewed-on: https://go-review.googlesource.com/c/go/+/657055
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
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test/codegen: tighten the TrailingZeros64 test on 386

Make the TrailingZeros64 code generation check more specific for 386.
Just checking for BSFL will match both the generic 64 bit decomposition
and the custom 386 lowering.

Change-Id: I62076f1889af0ef1f29704cba01ab419cae0c6e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/656996
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Reviewed-by: Keith Randall <khr@golang.org>

runtime: only set isExtraInC if there are no Go frames left

mp.isExtraInC is intended to indicate that this M has no Go frames at
all; it is entirely executing in C.

If there was a cgocallback to Go and then a cgocall to C, such that the
leaf frames are C, that is fine. e.g., traceback can handle this fine
with SetCgoTraceback (or by simply skipping the C frames).

However, we currently mismanage isExtraInC, unconditionally setting it
on return from cgocallback. This means that if there are two levels of
cgocallback, we end up running Go code with isExtraInC set.

1. C-created thread calls into Go function 1 (via cgocallback).
2. Go function 1 calls into C function 1 (via cgocall).
3. C function 1 calls into Go function 2 (via cgocallback).
4. Go function 2 returns back to C function 1 (returning via the remainder of cgocallback).
5. C function 1 returns back to Go function 1 (returning via the remainder of cgocall).
6. Go function 1 is now running with mp.isExtraInC == true.

The fix is simple; only set isExtraInC on return from cgocallback if
there are no more Go frames. There can't be more Go frames unless there
is an active cgocall out of the Go frames.

Fixes #72870.

Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
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encoding/asn1: make sure implicit fields roundtrip

Make sure Marshal and Unmarshal support the same field tags for implicit
encoding choices. In particular this adds support for Unmarshalling
implicitly tagged GeneralizedTime fields. Also add tests and update the
docs.

Fixes #72078

Change-Id: I21465ee4bcd73a7db0d0c36b2df53cabfc480185
Reviewed-on: https://go-review.googlesource.com/c/go/+/654275
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cmd/compile: don't move nilCheck operations during tighten

Nil checks need to stay in their original blocks. They cannot
be moved to a following conditionally-executed block.

Fixes #72860

Change-Id: Ic2d66cdf030357d91f8a716a004152ba4c016f77
Reviewed-on: https://go-review.googlesource.com/c/go/+/657715
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Reviewed-by: Keith Randall <khr@google.com>
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cmd/internal/obj/loong64: add {V,XV}{FSQRT/FRECIP/FRSQRT}.{S/D} instructions support

Go asm syntax:
 V{FSQRT/FRECIP/FRSQRT}{F/D} VJ, VD
XV{FSQRT/FRECIP/FRSQRT}{F/D} XJ, XD

Equivalent platform assembler syntax:
 v{fsqrt/frecip/frsqrt}.{s/d} vd, vj
xv{fsqrt/frecip/frsqrt}.{s/d} xd, xj

Change-Id: I3fdbe3193659d7532164451b087ccf725053172f
Reviewed-on: https://go-review.googlesource.com/c/go/+/636395
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
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crypto/x509: change how we retrieve chains on darwin

Instead of using the deprecated SecTrustGetCertificateAtIndex and
SecTrustGetCertificateCount method, use the SecTrustCopyCertificateChain
method.

This method require macOS 12+, which will be the minimum supported
version in 1.25.

Change-Id: I9a5ef75431cdb84f1cbe4eee47e6e9e2da4dea03
Reviewed-on: https://go-review.googlesource.com/c/go/+/654376
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crypto/x509,ecoding/asn1: better handling of weird encodings

For various cursed reasons we need to support the BMPString and
T61String ASN.1 string encodings. These types use the defunct UCS-2 and
T.61 character encodings respectively.

This change rejects some characters when decoding BMPStrings which are
not valid in UCS-2, and properly parses T61Strings instead of treating
them as plain UTF-8.

While still not perfect, this matches the behavior of most other
implementations, particularly BoringSSL. Ideally we'd just remove
support for these ASN.1 types (particularly in crypto/x509, where we
don't actually expose any API), but doing so is likely to break some
deploy certificates which unfortunately still use these types in DNs,
despite them being deprecated since 1999/2002.

Fixes #71862

Change-Id: Ib8f392656a35171e48eaf71a200be6d7605b2f02
Reviewed-on: https://go-review.googlesource.com/c/go/+/651275
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crypto/tls/internal/fips140tls: use crypto/fips140

There is no need for fips140tls to depend on an internal package, it
can use crypto/fips140 directly.

Both approaches are equivalent, but using crypto/fips140 makes us
exercise a public API and sets precedence.

Change-Id: I668e80ee62b711bc60821cee3a54232a33295ee1
Reviewed-on: https://go-review.googlesource.com/c/go/+/642035
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crypto/tls: relax native FIPS 140-3 mode

We are going to stick to BoringSSL's policy for Go+BoringCrypto, but
when using the native FIPS 140-3 module we can allow Ed25519, ML-KEM,
and P-521.

NIST SP 800-52r2 is stricter, but it only applies to some entities, so
they can restrict the profile with Config.

Fixes #71757

Change-Id: I6a6a4656eb02e56d079f0a22f98212275a40a679
Reviewed-on: https://go-review.googlesource.com/c/go/+/650576
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: David Chase <drchase@google.com>

crypto/tls: clean up supported/default/allowed parameters

Cleaned up a lot of the plumbing to make it consistently follow this
logic: clone the preference order; filter by user preference; filter by
FIPS policy. There should be no behavior changes.

Updates #71757

Change-Id: I6a6a4656eb02e56d079f0a22f98212275a400000
Reviewed-on: https://go-review.googlesource.com/c/go/+/657096
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>

cmd/go: permit additional cflags when compiling

In CL 475375 the Go command started to generate the "preferlinkext"
token file for "strange/dangerous" compiler flags. This serves as a hint
to the Go linker whether to call the external linker or not.

Permit compiler flag used by the hermetic_cc_toolchain bzlmod.

As a side effect, it also allows these flags to appear
in #cgo directives in source code. We don't know of any cases
where that is actually useful, but it appears to be harmless
and simplifies the implementation of the internal linking change.

Fixes #72842

Change-Id: Ic6de29b535a4e2c0720f383567ea6b3c7ca4f541
Reviewed-on: https://go-review.googlesource.com/c/go/+/657575
Auto-Submit: Ian Lance Taylor <iant@google.com>
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>

crypto/tls: add ConnectionState.CurveID

This required adding a new field to SessionState for TLS 1.0–1.2, since
the key exchange is not repeated on resumption. The additional field is
unfortunately not backwards compatible because current Go versions check
that the encoding has no extra data at the end, but will cause
cross-version tickets to be ignored. Relaxed that so we can add fields
in a backwards compatible way the next time.

For the cipher suite, we check that the session's is still acceptable
per the Config. That would arguably make sense here, too: if a Config
for example requires PQ, we should reject resumptions of connections
that didn't use PQ. However, that only applies to pre-TLS 1.3
connections, since in TLS 1.3 we always do a fresh key exchange on
resumption. Since PQ is the only main differentiator between key
exchanges (aside from off-by-default non-PFS RSA, which are controlled
by the cipher suite in TLS 1.0–1.2) and it's PQ-only, we can skip that
check.

Fixes #67516

Change-Id: I6a6a465681a6292edf66c7b8df8f4aba4171a76b
Reviewed-on: https://go-review.googlesource.com/c/go/+/653315
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
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Reviewed-by: Roland Shoemaker <roland@golang.org>

crypto/tls: allow P-521 in FIPS 140-3 mode and Go+BoringCrypto

Partially reverts CL 587296, restoring the Go+BoringCrypto 1.23 behavior
in terms of supported curves.

Updates #71757

Change-Id: I6a6a465651a8407056fd0fae091d10a945b37997
Reviewed-on: https://go-review.googlesource.com/c/go/+/657095
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Filippo Valsorda <filippo@golang.org>

doc/next: add release note for new toolchain line behavior

The go command will now no longer update the toolchain line implicitly
to the local toolchain version when updating the go line. Document that
in a release note.

For #65847

Change-Id: I4e970d881a43c22292fe9fa65a9835d0214ef7bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/657178
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/go/internal/load,cmd/link/internal/ld: use objabi.LookupPkgSpecial(pkg).Runtime

As suggested by Michael in CL 655515.

Change-Id: Idf0b879287bd777d03443aebc7351fcb0d724885
GitHub-Last-Rev: 58eda020f5310f873674f56903facec4f212d6c0
GitHub-Pull-Request: golang/go#72806
Reviewed-on: https://go-review.googlesource.com/c/go/+/656856
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
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syscall: use testing.T.Context

Change-Id: I62763878d51598bf1ae0a4e75441e1d3a4b86aa3
Reviewed-on: https://go-review.googlesource.com/c/go/+/656955
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

test/codegen: remove plan9/amd64 specific array zeroing/copying tests

The compiler previously avoided the use of MOVUPS on plan9/amd64. This
was changed in CL 655875, however the codegen tests were not updated
and now fail (seemingly the full codegen tests do not run anywhere,
not even on the longtest builders).

Change-Id: I388b60e7b0911048d4949c5029347f9801c018a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/656997
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Auto-Submit: Keith Randall <khr@google.com>

cmd/internal/dwarf: always use AT_ranges for scopes with DWARF 5

This patch extends the change in CL 657175 to apply the same abbrev
selection strategy to single-range lexical scopes that we're now using
for inlined routine bodies, when DWARF 5 is in effect. Ranges are more
compact and use fewer relocation than explicit hi/lo PC values, so we
might as well always use them.

Updates #26379.

Change-Id: Ieeaddf50e82acc4866010e29af32bcd1fb3b4f02
Reviewed-on: https://go-review.googlesource.com/c/go/+/657177
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Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

doc/next: add tentative DWARF 5 release note fragment

Add a small fragment describing the move to DWARF 5 for this release,
along with the name of the GOEXPERIMENT.

Updates #26379.

Change-Id: I3a30a71436133e2e0a5edf1ba0db84b9cc17cc5c
Reviewed-on: https://go-review.googlesource.com/c/go/+/657176
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Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

cmd/link: only check PIE size difference when the linkmode is the same

Currently we check the size difference between non-PIE and PIE binaries
without specifying a linkmode (and that is presumed to be internal).
However, on some platforms (like openbsd/arm64), the use of
-buildmode=pie results in external linking. Ensure that we only test
internally linked non-PIE against internally linked PIE and externally
linked non-PIE against externally linked PIE, avoiding unexpected
differences.

Fixes #72818

Change-Id: I7e1da0976a4b5de387a59d0d6c04f58498a8eca0
Reviewed-on: https://go-review.googlesource.com/c/go/+/657035
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Than McIntosh <thanm@golang.org>

cmd/compile: simplify bounded shift on loong64

Use the shiftIsBounded function to generate more efficient shift instructions.
This change also optimize shift ops when the shift value is v&63 and v&31.

goos: linux
goarch: loong64
pkg: math/bits
cpu: Loongson-3A6000-HV @ 2500.00MHz
                |  CL 627855   |               this CL                |
                |    sec/op    |    sec/op     vs base                |
LeadingZeros      1.1005n ± 0%   0.8425n ± 1%  -23.44% (p=0.000 n=10)
LeadingZeros8      1.502n ± 0%    1.501n ± 0%   -0.07% (p=0.001 n=10)
LeadingZeros16     1.502n ± 0%    1.501n ± 0%   -0.07% (p=0.000 n=10)
LeadingZeros32    0.9511n ± 0%   0.8050n ± 0%  -15.36% (p=0.000 n=10)
LeadingZeros64    1.1195n ± 0%   0.8423n ± 0%  -24.76% (p=0.000 n=10)
TrailingZeros     0.8086n ± 0%   0.8005n ± 0%   -1.00% (p=0.000 n=10)
TrailingZeros8     1.031n ± 1%    1.035n ± 1%        ~ (p=0.136 n=10)
TrailingZeros16   0.8114n ± 0%   0.8254n ± 1%   +1.73% (p=0.000 n=10)
TrailingZeros32   0.8090n ± 0%   0.8005n ± 0%   -1.05% (p=0.000 n=10)
TrailingZeros64   0.8089n ± 1%   0.8005n ± 0%   -1.04% (p=0.000 n=10)
OnesCount         0.8677n ± 0%   1.2010n ± 0%  +38.41% (p=0.000 n=10)
OnesCount8        0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.000 n=10)
OnesCount16       0.9344n ± 0%   1.2010n ± 0%  +28.53% (p=0.000 n=10)
OnesCount32       0.8677n ± 0%   1.2010n ± 0%  +38.41% (p=0.000 n=10)
OnesCount64       1.2010n ± 0%   0.8671n ± 0%  -27.80% (p=0.000 n=10)
RotateLeft        0.8009n ± 0%   0.6671n ± 0%  -16.71% (p=0.000 n=10)
RotateLeft8        1.202n ± 0%    1.327n ± 0%  +10.40% (p=0.000 n=10)
RotateLeft16      0.8036n ± 0%   0.8218n ± 0%   +2.26% (p=0.000 n=10)
RotateLeft32      0.6674n ± 0%   0.8004n ± 0%  +19.94% (p=0.000 n=10)
RotateLeft64      0.6674n ± 0%   0.8004n ± 0%  +19.94% (p=0.000 n=10)
Reverse           0.4067n ± 1%   0.4122n ± 1%   +1.38% (p=0.001 n=10)
Reverse8          0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.000 n=10)
Reverse16         0.8009n ± 0%   0.8005n ± 0%   -0.05% (p=0.000 n=10)
Reverse32         0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.001 n=10)
Reverse64         0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.008 n=10)
ReverseBytes      0.4057n ± 1%   0.4133n ± 1%   +1.90% (p=0.000 n=10)
ReverseBytes16    0.8009n ± 0%   0.8004n ± 0%   -0.07% (p=0.000 n=10)
ReverseBytes32    0.8009n ± 0%   0.8005n ± 0%   -0.05% (p=0.000 n=10)
ReverseBytes64    0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.000 n=10)
Add                1.201n ± 0%    1.201n ± 0%        ~ (p=1.000 n=10)
Add32              1.201n ± 0%    1.201n ± 0%        ~ (p=0.474 n=10)
Add64              1.201n ± 0%    1.201n ± 0%        ~ (p=1.000 n=10)
Add64multiple      1.832n ± 0%    1.828n ± 0%   -0.22% (p=0.001 n=10)
Sub                1.201n ± 0%    1.201n ± 0%        ~ (p=1.000 n=10)
Sub32              1.602n ± 0%    1.601n ± 0%   -0.06% (p=0.000 n=10)
Sub64              1.201n ± 0%    1.201n ± 0%        ~ (p=0.474 n=10)
Sub64multiple      2.402n ± 0%    2.400n ± 0%   -0.10% (p=0.000 n=10)
Mul               0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.000 n=10)
Mul32             0.8009n ± 0%   0.8004n ± 0%   -0.06% (p=0.000 n=10)
Mul64             0.8008n ± 0%   0.8004n ± 0%   -0.05% (p=0.000 n=10)
Div                9.083n ± 0%    7.638n ± 0%  -15.91% (p=0.000 n=10)
Div32              4.011n ± 0%    4.009n ± 0%   -0.05% (p=0.000 n=10)
Div64              9.711n ± 0%    8.204n ± 0%  -15.51% (p=0.000 n=10)
geomean            1.083n         1.078n        -0.40%

goos: linux
goarch: loong64
pkg: math/bits
cpu: Loongson-3A5000 @ 2500.00MHz
                |  CL 627855   |               this CL                |
                |    sec/op    |    sec/op     vs base                |
LeadingZeros       1.341n ± 4%    1.331n ± 2%   -0.71% (p=0.008 n=10)
LeadingZeros8      1.781n ± 0%    1.766n ± 1%   -0.84% (p=0.011 n=10)
LeadingZeros16     1.782n ± 0%    1.767n ± 0%   -0.79% (p=0.001 n=10)
LeadingZeros32     1.341n ± 1%    1.333n ± 0%   -0.52% (p=0.001 n=10)
LeadingZeros64     1.338n ± 0%    1.333n ± 0%   -0.37% (p=0.008 n=10)
TrailingZeros     0.9025n ± 0%   0.8077n ± 0%  -10.50% (p=0.000 n=10)
TrailingZeros8     1.056n ± 0%    1.089n ± 1%   +3.17% (p=0.001 n=10)
TrailingZeros16    1.101n ± 0%    1.102n ± 0%   +0.09% (p=0.011 n=10)
TrailingZeros32   0.9024n ± 1%   0.8083n ± 0%  -10.43% (p=0.000 n=10)
TrailingZeros64   0.9028n ± 1%   0.8087n ± 0%  -10.43% (p=0.000 n=10)
OnesCount          1.482n ± 1%    1.302n ± 0%  -12.15% (p=0.000 n=10)
OnesCount8         1.206n ± 0%    1.207n ± 2%   +0.12% (p=0.000 n=10)
OnesCount16        1.534n ± 0%    1.402n ± 0%   -8.58% (p=0.000 n=10)
OnesCount32        1.531n ± 1%    1.302n ± 0%  -14.99% (p=0.000 n=10)
OnesCount64        1.302n ± 0%    1.538n ± 1%  +18.16% (p=0.000 n=10)
RotateLeft        0.8083n ± 0%   0.8087n ± 1%        ~ (p=0.579 n=10)
RotateLeft8        1.310n ± 0%    1.323n ± 0%   +0.95% (p=0.001 n=10)
RotateLeft16       1.149n ± 0%    1.165n ± 1%   +1.35% (p=0.001 n=10)
RotateLeft32      0.8093n ± 0%   0.8105n ± 0%        ~ (p=0.393 n=10)
RotateLeft64      0.8088n ± 0%   0.8090n ± 0%        ~ (p=0.739 n=10)
Reverse           0.5109n ± 0%   0.5172n ± 1%   +1.25% (p=0.000 n=10)
Reverse8          0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.000 n=10)
Reverse16         0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.002 n=10)
Reverse32         0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.000 n=10)
Reverse64         0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.005 n=10)
ReverseBytes      0.5122n ± 2%   0.5182n ± 1%        ~ (p=0.060 n=10)
ReverseBytes16    0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.005 n=10)
ReverseBytes32    0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.005 n=10)
ReverseBytes64    0.8010n ± 0%   0.8011n ± 0%   +0.01% (p=0.001 n=10)
Add                1.201n ± 4%    1.202n ± 0%   +0.08% (p=0.028 n=10)
Add32              1.201n ± 0%    1.202n ± 2%   +0.08% (p=0.014 n=10)
Add64              1.201n ± 1%    1.202n ± 0%   +0.08% (p=0.025 n=10)
Add64multiple      1.902n ± 0%    1.913n ± 0%   +0.55% (p=0.004 n=10)
Sub                1.201n ± 0%    1.202n ± 3%   +0.08% (p=0.001 n=10)
Sub32              1.654n ± 0%    1.656n ± 1%        ~ (p=0.117 n=10)
Sub64              1.201n ± 0%    1.202n ± 0%   +0.08% (p=0.001 n=10)
Sub64multiple      2.180n ± 4%    2.159n ± 1%   -0.96% (p=0.006 n=10)
Mul               0.9345n ± 0%   0.9346n ± 0%   +0.01% (p=0.000 n=10)
Mul32              1.030n ± 0%    1.050n ± 1%   +1.94% (p=0.000 n=10)
Mul64             0.9345n ± 0%   0.9346n ± 1%   +0.01% (p=0.000 n=10)
Div                11.57n ± 1%    11.12n ± 0%   -3.85% (p=0.000 n=10)
Div32              4.337n ± 1%    4.341n ± 1%        ~ (p=0.286 n=10)
Div64              12.76n ± 0%    12.02n ± 3%   -5.80% (p=0.000 n=10)
geomean            1.252n         1.235n        -1.32%

Change-Id: Iec4cfd2b83bb0f946068c1d657369ff081d95b04
Reviewed-on: https://go-review.googlesource.com/c/go/+/628575
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: David Chase <drchase@google.com>

cmd/internal/obj/loong64: add {V,XV}DIV{B/H/W/V}[U] and {V,XV}MOD{B/H/W/V}[U] instructions support

Go asm syntax:
 VDIV{B/H/W/V}[U] VK, VJ, VD
XVDIV{B/H/W/V}[U] XK, XJ, XD
 VMOD{B/H/W/V}[U] VK, VJ, VD
XVMOD{B/H/W/V}[U] XK, XJ, XD

Equivalent platform assembler syntax:
 vdiv.{b/h/w/d}[u] vd, vj, vk
xvdiv.{b/h/w/d}[u] xd, xj, xk
 vmod.{b/h/w/d}[u] vd, vj, vk
xvmod.{b/h/w/d}[u] xd, xj, xk

Change-Id: I3676721c3c415de0f2ebbd480ecd1b2400a28dba
Reviewed-on: https://go-review.googlesource.com/c/go/+/636376
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

mime/multipart: add helper to build content-disposition header contents

This PR adds an helper FileContentDisposition that builds multipart
Content-Disposition header contents with field name and file name,
escaping quotes and escape characters.

The  function is then called in the related helper CreateFormFile.

The new function allows users to add other custom MIMEHeaders,
without having to rewrite the char escaping logic of field name and
file name, which is provided by the new helper.

Fixes #46771

Change-Id: Ifc82a79583feb6dd609ca1e6024e612fb58c05ce
GitHub-Last-Rev: 969f846fa967d2b3eca7a21ee096b299b8a94546
GitHub-Pull-Request: golang/go#63324
Reviewed-on: https://go-review.googlesource.com/c/go/+/531995
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

cmd/go: don't write own toolchain line when updating go line

The Go command had a behavior of writing its own toolchain name when
updating the go line in a go.mod (for example when a user runs go get
go@version). This behavior was often undesirable and the toolchain line
was often removed by users before checking in go.mod files (including in
the x/ repos). It also led to user confusion.

This change removes that behavior. A toolchain line will not be added if
one wasn't present before. The toolchain line can still be removed
though: the toolchain line must be at least the go version, so if the go
version is increased above the toolchain version, the toolchain version
will be bumped up to that go version. Then the toolchain line will then
be dropped because go <version> implies toolchain <version>.

Making this change slightly hurts reproducability because future go
commands run on the go.mod file may be run with a different toolchain
than the one that used it, but that doesn't seem to be worth the
confusion the behavior resulted in.

We expect this change will not have negative consequences, but it could
be possible, and we would like to hear from any users that depended on
the previous behavior in case we need to roll it back before the
release.

Fixes #65847

Change-Id: Id795b7f762e4f90ba0fa8c7935d03f32dfc8590e
Reviewed-on: https://go-review.googlesource.com/c/go/+/656835
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

net: deflake recently added TestCloseUnblocksReadUDP

Fixes #72802

Change-Id: I0dd457ef81a354f61c9de306e4609efdbe3d69b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/656857
Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Bypass: Brad Fitzpatrick <bradfitz@golang.org>

cmd/internal/dwarf: fix bug in inlined func DIE range DWARF 5 info

This patch changes the strategy we use in the compiler for handling
range information for inlined subroutine bodies, fixing a bug in how
this was handled for DWARF 5.  The high and lo PC values being emitted
for DW_TAG_inlined_subroutine DIEs were incorrect, pointing to the
start of functions instead of the proper location. The fix in this
patch is to move to unconditionally using DW_AT_ranges for inlined
subroutines, even those with only a single range.

Background: prior to this point, if a given inlined function body had
a single contiguous range, we'd pick an abbrev entry for it with
explicit DW_AT_low_pc and DW_AT_high_pc attributes. If the extent of
the code for the inlined body was not contiguous (which can happen),
we'd select an abbrev that used a DW_AT_ranges attribute instead. This
strategy (preferring explicit hi/lo PC attrs for a single-range func)
made sense for DWARF 4, since in DWARF 4 the representation used in
the .debug_ranges section was especially heavyweight (lots of space,
lots of relocations), so having explicit hi/lo PC attrs was less
expensive.

With DWARF 5 range info is written to the .debug_rnglists section, and
the representation here is much more compact. Specifically, a single
hi/lo range can be represented using a base address in addrx format
(max of 4 bytes, but more likely 2 or 3) followed by start and
endpoints of the range in ULEB128 format. This combination is more
compact spacewise than the explicit hi/lo values, and has fewer
relocations (0 as opposed to 2).

Note: we should at some point consider applying this same strategy to
lexical scopes, since we can probably reap some of the same benefits
there as well.

Updates #26379.
Fixes #72821.

Change-Id: Ifb65ecc6221601bad2ca3939f9b69964c1fafc7c
Reviewed-on: https://go-review.googlesource.com/c/go/+/657175
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>

log/slog: optimize appendKey to reduce allocations

This change introduces a new method, `appendTwoStrings`, which
optimizes the `appendKey` function by avoiding the allocation of a
temporary string (string concatenation of prefix and key). Instead, it
directly appends the prefix and key to the buffer.

Additionally, added `BenchmarkAppendKey` benchmark tests to validate performance improvements.

This change improves performance in cases where large prefixes are used,
as verified by the following benchmarks:

goos: darwin
goarch: arm64
pkg: log/slog
cpu: Apple M1 Max
                             │   old.out   │               new.out               │
                             │   sec/op    │   sec/op     vs base                │
AppendKey/prefix_size_5-10     44.41n ± 0%   35.62n ± 0%  -19.80% (p=0.000 n=10)
AppendKey/prefix_size_10-10    48.17n ± 0%   39.12n ± 0%  -18.80% (p=0.000 n=10)
AppendKey/prefix_size_30-10    84.50n ± 0%   62.30n ± 0%  -26.28% (p=0.000 n=10)
AppendKey/prefix_size_50-10    124.9n ± 0%   102.3n ± 0%  -18.09% (p=0.000 n=10)
AppendKey/prefix_size_100-10   203.6n ± 1%   168.7n ± 0%  -17.14% (p=0.000 n=10)
geomean                        85.61n        68.41n       -20.09%

                             │    old.out    │                 new.out                 │
                             │     B/op      │    B/op     vs base                     │
AppendKey/prefix_size_5-10      0.000 ± 0%     0.000 ± 0%         ~ (p=1.000 n=10) ¹
AppendKey/prefix_size_10-10     0.000 ± 0%     0.000 ± 0%         ~ (p=1.000 n=10) ¹
AppendKey/prefix_size_30-10     48.00 ± 0%      0.00 ± 0%  -100.00% (p=0.000 n=10)
AppendKey/prefix_size_50-10    128.00 ± 0%     64.00 ± 0%   -50.00% (p=0.000 n=10)
AppendKey/prefix_size_100-10    224.0 ± 0%     112.0 ± 0%   -50.00% (p=0.000 n=10)
geomean                                    ²               ?                       ² ³
¹ all samples are equal
² summaries must be >0 to compute geomean
³ ratios must be >0 to compute geomean

                             │   old.out    │                 new.out                 │
                             │  allocs/op   │ allocs/op   vs base                     │
AppendKey/prefix_size_5-10     0.000 ± 0%     0.000 ± 0%         ~ (p=1.000 n=10) ¹
AppendKey/prefix_size_10-10    0.000 ± 0%     0.000 ± 0%         ~ (p=1.000 n=10) ¹
AppendKey/prefix_size_30-10    1.000 ± 0%     0.000 ± 0%  -100.00% (p=0.000 n=10)
AppendKey/prefix_size_50-10    2.000 ± 0%     1.000 ± 0%   -50.00% (p=0.000 n=10)
AppendKey/prefix_size_100-10   2.000 ± 0%     1.000 ± 0%   -50.00% (p=0.000 n=10)
geomean                                   ²               ?                       ² ³
¹ all samples are equal
² summaries must be >0 to compute geomean
³ ratios must be >0 to compute geomean

This patch improves performance without altering the external behavior of the `slog` package.

Change-Id: I8b47718de522196f06e0ddac48af73e352d2e5cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/631415
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/compile/internal/ssagen: use an alias for math/bits.Len

Rather than using a specific intrinsic for math/bits.Len, use a pair of
aliases instead. This requires less code and automatically adapts when
platforms have a math/bits.Len32 or math/bits.Len64 intrinsic.

Change-Id: I28b300172daaee26ef82a7530d9e96123663f541
Reviewed-on: https://go-review.googlesource.com/c/go/+/656995
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Auto-Submit: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>

math/big: update calibration tests and recalibrate

Refactor calibration tests to use the same logic for all.

Choosing thresholds that are broadly appropriate for all systems is part science
but also part guesswork and judgement. We could instead set per-GOOS/GOARCH
thresholds, but that seems like too much work, and even then there would be
variation between different chips within a GOOS/GOARCH.
(For example see the three linux/amd64 systems benchmarked below.)

The thresholds chosen in this CL are:

karatsubaThreshold = 40 // unchanged
basicSqrThreshold = 12 // was 20
karatsubaSqrThreshold = 80 // was 260
divRecursiveThreshold = 40 // was 100

The new file calibrate.md explains the calibration process and links to graphs
justifying those values. (The graphs are hosted on swtch.com to avoid adding
a megabyte of extra data to the Go repo and Go distributions.)

A rendered copy of calibrate.md is at https://swtch.com/math/big/calibrate.html.

goos: linux
goarch: amd64
pkg: math/big
cpu: Intel(R) Xeon(R) Platinum 8481C CPU @ 2.70GHz
                         │     old      │                 new                 │
                         │    sec/op    │   sec/op     vs base                │
Div/20/10-88                13.13n ± 2%   13.14n ± 2%        ~ (p=0.494 n=15)
Div/40/20-88                13.13n ± 2%   13.14n ± 2%        ~ (p=0.137 n=15)
Div/100/50-88               25.50n ± 0%   25.51n ± 0%        ~ (p=0.038 n=15)
Div/200/100-88              113.1n ± 1%   116.0n ± 3%   +2.56% (p=0.000 n=15)
Div/400/200-88              135.3n ± 0%   137.1n ± 1%        ~ (p=0.004 n=15)
Div/1000/500-88             259.9n ± 1%   259.0n ± 2%        ~ (p=0.182 n=15)
Div/2000/1000-88            568.8n ± 1%   564.7n ± 3%        ~ (p=0.927 n=15)
Div/20000/10000-88          25.79µ ± 1%   22.11µ ± 2%  -14.26% (p=0.000 n=15)
Div/200000/100000-88        755.1µ ± 1%   737.6µ ± 1%   -2.32% (p=0.000 n=15)
Div/2000000/1000000-88      31.30m ± 0%   31.20m ± 1%        ~ (p=0.081 n=15)
Div/20000000/10000000-88     1.268 ± 0%    1.265 ± 0%        ~ (p=0.011 n=15)
NatMul/10-88                142.6n ± 0%   142.9n ± 7%        ~ (p=0.145 n=15)
NatMul/100-88               4.347µ ± 0%   4.350µ ± 3%        ~ (p=0.430 n=15)
NatMul/1000-88              187.6µ ± 0%   188.4µ ± 2%        ~ (p=0.004 n=15)
NatMul/10000-88             8.052m ± 0%   8.057m ± 1%        ~ (p=0.148 n=15)
NatMul/100000-88            260.6m ± 0%   260.7m ± 0%        ~ (p=0.512 n=15)
NatSqr/1-88                 26.58n ± 5%   27.96n ± 8%        ~ (p=0.574 n=15)
NatSqr/2-88                 42.35n ± 7%   44.87n ± 6%        ~ (p=0.690 n=15)
NatSqr/3-88                 53.28n ± 4%   55.62n ± 5%        ~ (p=0.151 n=15)
NatSqr/5-88                 76.26n ± 6%   81.43n ± 6%   +6.78% (p=0.000 n=15)
NatSqr/8-88                 110.8n ± 5%   116.4n ± 6%        ~ (p=0.040 n=15)
NatSqr/10-88                141.4n ± 4%   147.8n ± 4%        ~ (p=0.011 n=15)
NatSqr/20-88                325.8n ± 3%   341.7n ± 4%   +4.88% (p=0.000 n=15)
NatSqr/30-88                536.8n ± 3%   556.1n ± 4%        ~ (p=0.027 n=15)
NatSqr/50-88                1.168µ ± 3%   1.197µ ± 3%        ~ (p=0.442 n=15)
NatSqr/80-88                2.527µ ± 2%   2.480µ ± 2%   -1.86% (p=0.000 n=15)
NatSqr/100-88               3.771µ ± 2%   3.535µ ± 2%   -6.26% (p=0.000 n=15)
NatSqr/200-88               14.03µ ± 2%   10.57µ ± 3%  -24.68% (p=0.000 n=15)
NatSqr/300-88               24.06µ ± 2%   20.57µ ± 2%  -14.52% (p=0.000 n=15)
NatSqr/500-88               65.43µ ± 1%   45.45µ ± 1%  -30.55% (p=0.000 n=15)
NatSqr/800-88              126.41µ ± 1%   94.13µ ± 2%  -25.54% (p=0.000 n=15)
NatSqr/1000-88              196.4µ ± 1%   135.1µ ± 1%  -31.18% (p=0.000 n=15)
NatSqr/10000-88             6.404m ± 0%   5.326m ± 1%  -16.84% (p=0.000 n=15)
NatSqr/100000-88            267.2m ± 0%   198.7m ± 0%  -25.64% (p=0.000 n=15)
geomean                     7.318µ        6.948µ        -5.06%

goos: linux
goarch: amd64
pkg: math/big
cpu: Intel(R) Xeon(R) CPU @ 3.10GHz
                         │     old     │                 new                 │
                         │   sec/op    │   sec/op     vs base                │
Div/20/10-16               22.23n ± 0%   22.23n ± 0%        ~ (p=0.973 n=15)
Div/40/20-16               22.23n ± 0%   22.23n ± 0%        ~ (p=0.226 n=15)
Div/100/50-16              55.27n ± 1%   55.59n ± 0%        ~ (p=0.004 n=15)
Div/200/100-16             174.7n ± 3%   175.9n ± 2%        ~ (p=0.645 n=15)
Div/400/200-16             208.8n ± 1%   209.5n ± 2%        ~ (p=0.169 n=15)
Div/1000/500-16            378.7n ± 2%   380.5n ± 2%        ~ (p=0.091 n=15)
Div/2000/1000-16           778.4n ± 1%   781.1n ± 2%        ~ (p=0.104 n=15)
Div/20000/10000-16         25.16µ ± 1%   24.93µ ± 1%   -0.91% (p=0.000 n=15)
Div/200000/100000-16       926.4µ ± 0%   927.7µ ± 1%        ~ (p=0.436 n=15)
Div/2000000/1000000-16     35.58m ± 0%   35.53m ± 0%        ~ (p=0.267 n=15)
Div/20000000/10000000-16    1.333 ± 0%    1.330 ± 0%        ~ (p=0.126 n=15)
NatMul/10-16               172.6n ± 0%   165.4n ± 0%   -4.17% (p=0.000 n=15)
NatMul/100-16              5.706µ ± 0%   5.503µ ± 0%   -3.56% (p=0.000 n=15)
NatMul/1000-16             220.8µ ± 0%   219.1µ ± 0%   -0.76% (p=0.000 n=15)
NatMul/10000-16            8.688m ± 0%   8.621m ± 0%   -0.77% (p=0.000 n=15)
NatMul/100000-16           333.3m ± 0%   333.5m ± 0%        ~ (p=0.512 n=15)
NatSqr/1-16                28.66n ± 1%   28.42n ± 3%   -0.84% (p=0.000 n=15)
NatSqr/2-16                48.29n ± 2%   48.19n ± 2%        ~ (p=0.042 n=15)
NatSqr/3-16                59.93n ± 0%   59.64n ± 2%   -0.48% (p=0.000 n=15)
NatSqr/5-16                88.05n ± 0%   87.89n ± 3%        ~ (p=0.066 n=15)
NatSqr/8-16                127.7n ± 0%   126.9n ± 3%   -0.63% (p=0.000 n=15)
NatSqr/10-16               170.4n ± 0%   169.7n ± 3%        ~ (p=0.004 n=15)
NatSqr/20-16               388.8n ± 0%   392.9n ± 3%        ~ (p=0.123 n=15)
NatSqr/30-16               635.2n ± 0%   641.7n ± 3%        ~ (p=0.123 n=15)
NatSqr/50-16               1.304µ ± 1%   1.314µ ± 3%        ~ (p=0.927 n=15)
NatSqr/80-16               2.709µ ± 1%   2.899µ ± 4%   +7.01% (p=0.000 n=15)
NatSqr/100-16              3.885µ ± 0%   3.981µ ± 4%        ~ (p=0.123 n=15)
NatSqr/200-16              13.29µ ± 2%   12.14µ ± 4%   -8.67% (p=0.000 n=15)
NatSqr/300-16              23.39µ ± 0%   22.51µ ± 3%   -3.78% (p=0.000 n=15)
NatSqr/500-16              58.13µ ± 1%   50.56µ ± 2%  -13.02% (p=0.000 n=15)
NatSqr/800-16              118.4µ ± 1%   107.6µ ± 2%   -9.11% (p=0.000 n=15)
NatSqr/1000-16             172.7µ ± 1%   151.8µ ± 2%  -12.11% (p=0.000 n=15)
NatSqr/10000-16            6.065m ± 1%   5.757m ± 1%   -5.08% (p=0.000 n=15)
NatSqr/100000-16           240.9m ± 0%   228.1m ± 0%   -5.32% (p=0.000 n=15)
geomean                    8.601µ        8.453µ        -1.71%

goos: linux
goarch: amd64
pkg: math/big
cpu: AMD Ryzen 9 7950X 16-Core Processor
                         │     old      │                  new                  │
                         │    sec/op    │    sec/op      vs base                │
Div/20/10-32               11.11n ±  0%    11.11n ±  1%        ~ (p=0.532 n=15)
Div/40/20-32               11.08n ±  1%    11.11n ±  0%        ~ (p=0.815 n=15)
Div/100/50-32              16.81n ±  0%    16.84n ± 29%        ~ (p=0.020 n=15)
Div/200/100-32             73.91n ±  0%    76.85n ± 11%   +3.98% (p=0.000 n=15)
Div/400/200-32             87.35n ±  0%    88.91n ± 34%   +1.79% (p=0.000 n=15)
Div/1000/500-32            169.3n ±  1%    168.9n ±  1%        ~ (p=0.049 n=15)
Div/2000/1000-32           369.3n ±  0%    369.0n ±  0%        ~ (p=0.108 n=15)
Div/20000/10000-32         15.92µ ±  0%    13.55µ ±  2%  -14.91% (p=0.000 n=15)
Div/200000/100000-32       491.4µ ±  0%    482.4µ ±  1%   -1.84% (p=0.000 n=15)
Div/2000000/1000000-32     20.09m ±  0%    19.96m ±  0%   -0.69% (p=0.000 n=15)
Div/20000000/10000000-32   756.5m ±  0%    755.5m ±  0%        ~ (p=0.089 n=15)
NatMul/10-32               125.4n ±  5%    124.8n ±  1%        ~ (p=0.588 n=15)
NatMul/100-32              2.952µ ±  3%    2.969µ ±  0%        ~ (p=0.237 n=15)
NatMul/1000-32             120.7µ ±  0%    121.1µ ±  0%   +0.30% (p=0.000 n=15)
NatMul/10000-32            4.845m ±  0%    4.839m ±  1%        ~ (p=0.653 n=15)
NatMul/100000-32           173.3m ±  0%    173.3m ±  0%        ~ (p=0.838 n=15)
NatSqr/1-32                31.18n ± 23%    32.08n ±  2%        ~ (p=0.015 n=15)
NatSqr/2-32                57.22n ± 28%    58.88n ±  2%        ~ (p=0.054 n=15)
NatSqr/3-32                61.34n ± 18%    64.33n ±  2%        ~ (p=0.237 n=15)
NatSqr/5-32                72.47n ± 17%    79.81n ±  3%        ~ (p=0.067 n=15)
NatSqr/8-32                83.26n ± 26%   100.10n ±  3%        ~ (p=0.016 n=15)
NatSqr/10-32               87.31n ± 43%   125.50n ±  2%        ~ (p=0.003 n=15)
NatSqr/20-32               193.5n ± 25%    244.4n ± 13%        ~ (p=0.002 n=15)
NatSqr/30-32               323.9n ± 17%    380.9n ±  6%        ~ (p=0.003 n=15)
NatSqr/50-32               713.4n ±  9%    761.7n ±  8%        ~ (p=0.419 n=15)
NatSqr/80-32               1.486µ ±  7%    1.609µ ±  5%   +8.28% (p=0.000 n=15)
NatSqr/100-32              2.115µ ±  9%    2.253µ ±  1%        ~ (p=0.104 n=15)
NatSqr/200-32              7.201µ ±  4%    6.610µ ±  1%   -8.21% (p=0.000 n=15)
NatSqr/300-32              13.08µ ±  2%    12.37µ ±  1%   -5.41% (p=0.000 n=15)
NatSqr/500-32              32.56µ ±  2%    27.83µ ±  2%  -14.52% (p=0.000 n=15)
NatSqr/800-32              66.83µ ±  3%    59.59µ ±  1%  -10.83% (p=0.000 n=15)
NatSqr/1000-32             98.09µ ±  1%    83.59µ ±  1%  -14.78% (p=0.000 n=15)
NatSqr/10000-32            3.445m ±  1%    3.245m ±  0%   -5.81% (p=0.000 n=15)
NatSqr/100000-32           137.3m ±  0%    127.0m ±  0%   -7.54% (p=0.000 n=15)
geomean                    4.897µ          4.972µ         +1.52%

goos: linux
goarch: arm64
pkg: math/big
                         │     old     │                 new                 │
                         │   sec/op    │   sec/op     vs base                │
Div/20/10-16               15.26n ± 2%   15.14n ± 1%        ~ (p=0.212 n=15)
Div/40/20-16               15.22n ± 1%   15.16n ± 0%        ~ (p=0.190 n=15)
Div/100/50-16              26.53n ± 2%   26.42n ± 0%   -0.41% (p=0.000 n=15)
Div/200/100-16             124.3n ± 0%   124.0n ± 0%        ~ (p=0.704 n=15)
Div/400/200-16             142.4n ± 0%   141.8n ± 0%        ~ (p=0.074 n=15)
Div/1000/500-16            262.0n ± 1%   261.3n ± 1%        ~ (p=0.046 n=15)
Div/2000/1000-16           532.6n ± 0%   532.5n ± 1%        ~ (p=0.798 n=15)
Div/20000/10000-16         22.27µ ± 0%   22.88µ ± 0%   +2.73% (p=0.000 n=15)
Div/200000/100000-16       890.4µ ± 0%   902.8µ ± 0%   +1.39% (p=0.000 n=15)
Div/2000000/1000000-16     35.03m ± 0%   35.10m ± 0%        ~ (p=0.305 n=15)
Div/20000000/10000000-16    1.380 ± 0%    1.385 ± 0%        ~ (p=0.019 n=15)
NatMul/10-16               177.6n ± 1%   175.6n ± 3%        ~ (p=0.480 n=15)
NatMul/100-16              5.675µ ± 0%   5.669µ ± 1%        ~ (p=0.705 n=15)
NatMul/1000-16             224.3µ ± 0%   224.6µ ± 0%        ~ (p=0.653 n=15)
NatMul/10000-16            8.735m ± 0%   8.739m ± 0%        ~ (p=0.567 n=15)
NatMul/100000-16           331.6m ± 0%   331.6m ± 1%        ~ (p=0.412 n=15)
NatSqr/1-16                43.69n ± 2%   42.77n ± 6%        ~ (p=0.383 n=15)
NatSqr/2-16                65.26n ± 2%   63.91n ± 5%        ~ (p=0.285 n=15)
NatSqr/3-16                73.95n ± 1%   72.25n ± 6%        ~ (p=0.198 n=15)
NatSqr/5-16                95.06n ± 1%   94.21n ± 3%        ~ (p=0.721 n=15)
NatSqr/8-16                155.5n ± 1%   153.4n ± 4%        ~ (p=0.170 n=15)
NatSqr/10-16               175.4n ± 1%   174.0n ± 2%        ~ (p=0.271 n=15)
NatSqr/20-16               360.8n ± 0%   358.5n ± 2%        ~ (p=0.170 n=15)
NatSqr/30-16               584.7n ± 0%   582.9n ± 1%        ~ (p=0.170 n=15)
NatSqr/50-16               1.323µ ± 0%   1.322µ ± 0%        ~ (p=0.627 n=15)
NatSqr/80-16               2.916µ ± 0%   2.674µ ± 0%   -8.30% (p=0.000 n=15)
NatSqr/100-16              4.365µ ± 0%   3.802µ ± 0%  -12.90% (p=0.000 n=15)
NatSqr/200-16              16.42µ ± 0%   11.29µ ± 0%  -31.26% (p=0.000 n=15)
NatSqr/300-16              28.07µ ± 0%   22.83µ ± 0%  -18.68% (p=0.000 n=15)
NatSqr/500-16              76.30µ ± 0%   50.06µ ± 0%  -34.39% (p=0.000 n=15)
NatSqr/800-16              147.5µ ± 0%   101.2µ ± 1%  -31.41% (p=0.000 n=15)
NatSqr/1000-16             228.6µ ± 0%   149.5µ ± 0%  -34.61% (p=0.000 n=15)
NatSqr/10000-16            7.417m ± 0%   6.025m ± 0%  -18.76% (p=0.000 n=15)
NatSqr/100000-16           309.2m ± 0%   214.9m ± 0%  -30.50% (p=0.000 n=15)
geomean                    8.559µ        7.906µ        -7.63%

goos: darwin
goarch: arm64
pkg: math/big
cpu: Apple M3 Pro
                         │     old      │                 new                 │
                         │    sec/op    │   sec/op     vs base                │
Div/20/10-12                9.577n ± 6%   9.473n ± 5%        ~ (p=0.384 n=15)
Div/40/20-12                9.480n ± 1%   9.430n ± 1%        ~ (p=0.019 n=15)
Div/100/50-12               14.82n ± 0%   14.82n ± 0%        ~ (p=0.845 n=15)
Div/200/100-12              83.94n ± 1%   84.35n ± 4%        ~ (p=0.512 n=15)
Div/400/200-12              102.7n ± 1%   102.9n ± 0%        ~ (p=0.845 n=15)
Div/1000/500-12             185.3n ± 1%   181.9n ± 1%   -1.83% (p=0.000 n=15)
Div/2000/1000-12            397.0n ± 1%   396.7n ± 0%        ~ (p=0.959 n=15)
Div/20000/10000-12          14.05µ ± 0%   13.70µ ± 1%        ~ (p=0.002 n=15)
Div/200000/100000-12        529.4µ ± 3%   526.7µ ± 2%        ~ (p=0.967 n=15)
Div/2000000/1000000-12      20.05m ± 0%   20.05m ± 0%        ~ (p=0.653 n=15)
Div/20000000/10000000-12    788.2m ± 1%   789.0m ± 1%        ~ (p=0.412 n=15)
NatMul/10-12                79.95n ± 1%   80.87n ± 1%   +1.15% (p=0.000 n=15)
NatMul/100-12               2.973µ ± 0%   2.986µ ± 2%        ~ (p=0.051 n=15)
NatMul/1000-12              122.6µ ± 5%   123.0µ ± 1%        ~ (p=0.783 n=15)
NatMul/10000-12             4.990m ± 1%   5.000m ± 1%        ~ (p=0.653 n=15)
NatMul/100000-12            185.3m ± 3%   190.3m ± 1%        ~ (p=0.089 n=15)
NatSqr/1-12                 11.84n ± 1%   11.88n ± 1%        ~ (p=0.735 n=15)
NatSqr/2-12                 21.01n ± 1%   21.44n ± 6%        ~ (p=0.039 n=15)
NatSqr/3-12                 25.59n ± 0%   26.74n ± 9%   +4.49% (p=0.000 n=15)
NatSqr/5-12                 36.78n ± 0%   37.04n ± 1%   +0.71% (p=0.000 n=15)
NatSqr/8-12                 63.09n ± 3%   63.22n ± 1%        ~ (p=0.846 n=15)
NatSqr/10-12                79.98n ± 0%   79.78n ± 0%        ~ (p=0.100 n=15)
NatSqr/20-12                174.0n ± 0%   175.5n ± 1%        ~ (p=0.361 n=15)
NatSqr/30-12                290.0n ± 0%   291.4n ± 0%        ~ (p=0.002 n=15)
NatSqr/50-12                655.2n ± 4%   658.1n ± 0%        ~ (p=0.060 n=15)
NatSqr/80-12                1.506µ ± 0%   1.397µ ± 5%   -7.24% (p=0.000 n=15)
NatSqr/100-12               2.273µ ± 0%   2.005µ ± 5%  -11.79% (p=0.000 n=15)
NatSqr/200-12               8.833µ ± 6%   6.109µ ± 0%  -30.84% (p=0.000 n=15)
NatSqr/300-12               15.15µ ± 4%   12.37µ ± 0%  -18.34% (p=0.000 n=15)
NatSqr/500-12               41.89µ ± 0%   27.70µ ± 1%  -33.88% (p=0.000 n=15)
NatSqr/800-12               80.72µ ± 0%   56.40µ ± 0%  -30.12% (p=0.000 n=15)
NatSqr/1000-12             127.06µ ± 1%   84.06µ ± 1%  -33.84% (p=0.000 n=15)
NatSqr/10000-12             4.130m ± 0%   3.390m ± 0%  -17.91% (p=0.000 n=15)
NatSqr/100000-12            173.2m ± 0%   131.2m ± 6%  -24.25% (p=0.000 n=15)
geomean                     4.489µ        4.189µ        -6.68%

Change-Id: Iaf65fd85457b003ebf07a787c875cda321b40cc9
Reviewed-on: https://go-review.googlesource.com/c/go/+/652058
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>

runtime: remove nextSampleNoFP from plan9

Plan 9 can use floating point now.

Change-Id: If721b243daa31853609cb3d2c535d86c106a1ee1
Reviewed-on: https://go-review.googlesource.com/c/go/+/655879
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>

math/big: simplify, speed up Karatsuba multiplication

The old Karatsuba implementation only operated on lengths that are
a power of two times a number smaller than karatsubaThreshold.
For example, when karatsubaThreshold = 40, multiplying a pair
of 99-word numbers runs karatsuba on the low 96 (= 39<<2) words
and then has to fix up the answer to include the high 3 words of each.

I suspect this requirement was needed to make the analysis of
how many temporary words to reserve easier, back when the
answer was 3*n and depended on exactly halving the size at
each Karatsuba step.

Now that we have the more flexible temporary allocation stack,
we can change Karatsuba to accept operands of odd length.
Doing so avoids most of the fixup that the old approach required.
For example, multiplying a pair of 99-word numbers runs
karatsuba on all 99 words now.

This is simpler and about the same speed or, for large cases, faster.

goos: linux
goarch: amd64
pkg: math/big
cpu: Intel(R) Xeon(R) CPU @ 3.10GHz
                            │     old     │                 new                 │
                            │   sec/op    │   sec/op     vs base                │
GCD10x10/WithoutXY-16         99.62n ± 3%   99.10n ± 3%        ~ (p=0.009 n=15)
GCD10x10/WithXY-16            243.4n ± 1%   245.2n ± 1%        ~ (p=0.009 n=15)
GCD100x100/WithoutXY-16       921.9n ± 1%   919.2n ± 1%        ~ (p=0.076 n=15)
GCD100x100/WithXY-16          1.527µ ± 1%   1.526µ ± 0%        ~ (p=0.813 n=15)
GCD1000x1000/WithoutXY-16     9.704µ ± 1%   9.696µ ± 0%        ~ (p=0.532 n=15)
GCD1000x1000/WithXY-16        14.03µ ± 1%   13.96µ ± 0%        ~ (p=0.014 n=15)
GCD10000x10000/WithoutXY-16   206.5µ ± 2%   206.5µ ± 0%        ~ (p=0.967 n=15)
GCD10000x10000/WithXY-16      398.0µ ± 1%   397.4µ ± 0%        ~ (p=0.683 n=15)
Div/20/10-16                  22.22n ± 0%   22.23n ± 0%        ~ (p=0.105 n=15)
Div/40/20-16                  22.23n ± 0%   22.23n ± 0%        ~ (p=0.307 n=15)
Div/100/50-16                 55.47n ± 0%   55.47n ± 0%        ~ (p=0.573 n=15)
Div/200/100-16                174.9n ± 1%   174.6n ± 1%        ~ (p=0.814 n=15)
Div/400/200-16                209.5n ± 1%   210.5n ± 1%        ~ (p=0.454 n=15)
Div/1000/500-16               379.9n ± 0%   383.5n ± 2%        ~ (p=0.123 n=15)
Div/2000/1000-16              780.1n ± 0%   784.6n ± 1%   +0.58% (p=0.000 n=15)
Div/20000/10000-16            25.22µ ± 1%   25.15µ ± 0%        ~ (p=0.213 n=15)
Div/200000/100000-16          921.8µ ± 1%   926.1µ ± 0%        ~ (p=0.009 n=15)
Div/2000000/1000000-16        37.91m ± 0%   35.63m ± 0%   -6.02% (p=0.000 n=15)
Div/20000000/10000000-16       1.378 ± 0%    1.336 ± 0%   -3.03% (p=0.000 n=15)
NatMul/10-16                  166.8n ± 4%   168.9n ± 3%        ~ (p=0.008 n=15)
NatMul/100-16                 5.519µ ± 2%   5.548µ ± 4%        ~ (p=0.032 n=15)
NatMul/1000-16                230.4µ ± 1%   220.2µ ± 1%   -4.43% (p=0.000 n=15)
NatMul/10000-16               8.569m ± 1%   8.640m ± 1%        ~ (p=0.005 n=15)
NatMul/100000-16              376.5m ± 1%   334.1m ± 0%  -11.26% (p=0.000 n=15)
NatSqr/1-16                   27.85n ± 5%   28.60n ± 2%        ~ (p=0.123 n=15)
NatSqr/2-16                   47.99n ± 2%   48.84n ± 1%        ~ (p=0.008 n=15)
NatSqr/3-16                   59.41n ± 2%   60.87n ± 2%   +2.46% (p=0.001 n=15)
NatSqr/5-16                   87.27n ± 2%   89.31n ± 3%        ~ (p=0.087 n=15)
NatSqr/8-16                   124.6n ± 3%   128.9n ± 3%        ~ (p=0.006 n=15)
NatSqr/10-16                  166.3n ± 3%   172.7n ± 3%        ~ (p=0.002 n=15)
NatSqr/20-16                  385.2n ± 2%   394.7n ± 3%        ~ (p=0.036 n=15)
NatSqr/30-16                  622.7n ± 3%   642.9n ± 3%        ~ (p=0.032 n=15)
NatSqr/50-16                  1.274µ ± 3%   1.323µ ± 4%        ~ (p=0.003 n=15)
NatSqr/80-16                  2.606µ ± 4%   2.714µ ± 4%        ~ (p=0.044 n=15)
NatSqr/100-16                 3.731µ ± 4%   3.871µ ± 4%        ~ (p=0.038 n=15)
NatSqr/200-16                 12.99µ ± 2%   13.09µ ± 3%        ~ (p=0.838 n=15)
NatSqr/300-16                 22.87µ ± 2%   23.25µ ± 2%        ~ (p=0.285 n=15)
NatSqr/500-16                 58.43µ ± 1%   58.25µ ± 2%        ~ (p=0.345 n=15)
NatSqr/800-16                 115.3µ ± 3%   116.2µ ± 3%        ~ (p=0.126 n=15)
NatSqr/1000-16                173.9µ ± 1%   174.3µ ± 1%        ~ (p=0.935 n=15)
NatSqr/10000-16               6.133m ± 2%   6.034m ± 1%   -1.62% (p=0.000 n=15)
NatSqr/100000-16              253.8m ± 1%   241.5m ± 0%   -4.87% (p=0.000 n=15)
geomean                       7.745µ        7.760µ        +0.19%

goos: linux
goarch: amd64
pkg: math/big
cpu: Intel(R) Xeon(R) Platinum 8481C CPU @ 2.70GHz
                            │     old     │                 new                  │
                            │   sec/op    │    sec/op     vs base                │
GCD10x10/WithoutXY-88         62.17n ± 4%   61.44n ±  0%   -1.17% (p=0.000 n=15)
GCD10x10/WithXY-88            173.4n ± 2%   172.4n ±  4%        ~ (p=0.615 n=15)
GCD100x100/WithoutXY-88       584.0n ± 1%   582.9n ±  0%        ~ (p=0.009 n=15)
GCD100x100/WithXY-88          1.098µ ± 1%   1.091µ ±  2%        ~ (p=0.002 n=15)
GCD1000x1000/WithoutXY-88     6.055µ ± 0%   6.049µ ±  0%        ~ (p=0.007 n=15)
GCD1000x1000/WithXY-88        9.430µ ± 0%   9.417µ ±  1%        ~ (p=0.123 n=15)
GCD10000x10000/WithoutXY-88   153.4µ ± 2%   149.0µ ±  2%   -2.85% (p=0.000 n=15)
GCD10000x10000/WithXY-88      350.6µ ± 3%   349.0µ ±  2%        ~ (p=0.126 n=15)
Div/20/10-88                  13.12n ± 0%   13.12n ±  1%    0.00% (p=0.042 n=15)
Div/40/20-88                  13.12n ± 0%   13.13n ±  0%        ~ (p=0.004 n=15)
Div/100/50-88                 25.49n ± 0%   25.49n ±  0%        ~ (p=0.452 n=15)
Div/200/100-88                115.7n ± 2%   113.8n ±  2%        ~ (p=0.212 n=15)
Div/400/200-88                135.0n ± 1%   136.1n ±  1%        ~ (p=0.005 n=15)
Div/1000/500-88               257.5n ± 1%   259.9n ±  1%        ~ (p=0.004 n=15)
Div/2000/1000-88              567.5n ± 1%   572.4n ±  2%        ~ (p=0.616 n=15)
Div/20000/10000-88            25.65µ ± 0%   25.77µ ±  1%        ~ (p=0.032 n=15)
Div/200000/100000-88          777.4µ ± 1%   754.3µ ±  1%   -2.97% (p=0.000 n=15)
Div/2000000/1000000-88        33.66m ± 0%   31.37m ±  0%   -6.81% (p=0.000 n=15)
Div/20000000/10000000-88       1.320 ± 0%    1.266 ±  0%   -4.04% (p=0.000 n=15)
NatMul/10-88                  151.9n ± 7%   143.3n ±  7%        ~ (p=0.878 n=15)
NatMul/100-88                 4.418µ ± 2%   4.337µ ±  3%        ~ (p=0.512 n=15)
NatMul/1000-88                206.8µ ± 1%   189.8µ ±  1%   -8.25% (p=0.000 n=15)
NatMul/10000-88               8.531m ± 1%   8.095m ±  0%   -5.12% (p=0.000 n=15)
NatMul/100000-88              298.9m ± 0%   260.5m ±  1%  -12.85% (p=0.000 n=15)
NatSqr/1-88                   27.55n ± 6%   28.25n ±  7%        ~ (p=0.024 n=15)
NatSqr/2-88                   44.71n ± 6%   46.21n ±  9%        ~ (p=0.024 n=15)
NatSqr/3-88                   55.44n ± 4%   58.41n ± 10%        ~ (p=0.126 n=15)
NatSqr/5-88                   80.71n ± 5%   81.41n ±  5%        ~ (p=0.032 n=15)
NatSqr/8-88                   115.7n ± 4%   115.4n ±  5%        ~ (p=0.814 n=15)
NatSqr/10-88                  147.4n ± 4%   147.3n ±  4%        ~ (p=0.505 n=15)
NatSqr/20-88                  337.8n ± 3%   337.3n ±  4%        ~ (p=0.814 n=15)
NatSqr/30-88                  556.9n ± 3%   557.6n ±  4%        ~ (p=0.814 n=15)
NatSqr/50-88                  1.208µ ± 4%   1.208µ ±  3%        ~ (p=0.910 n=15)
NatSqr/80-88                  2.591µ ± 3%   2.581µ ±  3%        ~ (p=0.705 n=15)
NatSqr/100-88                 3.870µ ± 3%   3.858µ ±  3%        ~ (p=0.846 n=15)
NatSqr/200-88                 14.43µ ± 3%   14.28µ ±  2%        ~ (p=0.383 n=15)
NatSqr/300-88                 24.68µ ± 2%   24.49µ ±  2%        ~ (p=0.624 n=15)
NatSqr/500-88                 66.27µ ± 1%   66.18µ ±  1%        ~ (p=0.735 n=15)
NatSqr/800-88                 128.7µ ± 1%   127.4µ ±  1%        ~ (p=0.050 n=15)
NatSqr/1000-88                198.7µ ± 1%   197.7µ ±  1%        ~ (p=0.229 n=15)
NatSqr/10000-88               6.582m ± 1%   6.426m ±  1%   -2.37% (p=0.000 n=15)
NatSqr/100000-88              274.3m ± 0%   267.3m ±  0%   -2.57% (p=0.000 n=15)
geomean                       6.518µ        6.438µ         -1.22%

goos: linux
goarch: arm64
pkg: math/big
                            │     old     │                 new                 │
                            │   sec/op    │   sec/op     vs base                │
GCD10x10/WithoutXY-16         61.70n ± 1%   61.32n ± 1%        ~ (p=0.361 n=15)
GCD10x10/WithXY-16            217.3n ± 1%   217.0n ± 1%        ~ (p=0.395 n=15)
GCD100x100/WithoutXY-16       569.7n ± 0%   572.6n ± 2%        ~ (p=0.213 n=15)
GCD100x100/WithXY-16          1.241µ ± 1%   1.236µ ± 1%        ~ (p=0.157 n=15)
GCD1000x1000/WithoutXY-16     5.558µ ± 0%   5.566µ ± 0%        ~ (p=0.228 n=15)
GCD1000x1000/WithXY-16        9.319µ ± 0%   9.326µ ± 0%        ~ (p=0.233 n=15)
GCD10000x10000/WithoutXY-16   126.4µ ± 2%   128.7µ ± 3%        ~ (p=0.081 n=15)
GCD10000x10000/WithXY-16      279.3µ ± 0%   278.3µ ± 5%        ~ (p=0.187 n=15)
Div/20/10-16                  15.12n ± 1%   15.21n ± 1%        ~ (p=0.490 n=15)
Div/40/20-16                  15.11n ± 0%   15.23n ± 1%        ~ (p=0.107 n=15)
Div/100/50-16                 26.53n ± 0%   26.50n ± 0%        ~ (p=0.299 n=15)
Div/200/100-16                123.7n ± 0%   124.0n ± 0%        ~ (p=0.086 n=15)
Div/400/200-16                142.5n ± 0%   142.4n ± 0%        ~ (p=0.039 n=15)
Div/1000/500-16               259.9n ± 1%   261.2n ± 1%        ~ (p=0.044 n=15)
Div/2000/1000-16              539.4n ± 1%   532.3n ± 1%   -1.32% (p=0.001 n=15)
Div/20000/10000-16            22.43µ ± 0%   22.32µ ± 0%   -0.49% (p=0.000 n=15)
Div/200000/100000-16          898.3µ ± 0%   889.6µ ± 0%   -0.96% (p=0.000 n=15)
Div/2000000/1000000-16        38.37m ± 0%   35.11m ± 0%   -8.49% (p=0.000 n=15)
Div/20000000/10000000-16       1.449 ± 0%    1.384 ± 0%   -4.48% (p=0.000 n=15)
NatMul/10-16                  182.0n ± 1%   177.8n ± 1%   -2.31% (p=0.000 n=15)
NatMul/100-16                 5.537µ ± 0%   5.693µ ± 0%   +2.82% (p=0.000 n=15)
NatMul/1000-16                229.9µ ± 0%   224.8µ ± 0%   -2.24% (p=0.000 n=15)
NatMul/10000-16               8.985m ± 0%   8.751m ± 0%   -2.61% (p=0.000 n=15)
NatMul/100000-16              371.1m ± 0%   331.5m ± 0%  -10.66% (p=0.000 n=15)
NatSqr/1-16                   46.77n ± 6%   42.76n ± 1%   -8.57% (p=0.000 n=15)
NatSqr/2-16                   66.99n ± 4%   63.62n ± 1%   -5.03% (p=0.000 n=15)
NatSqr/3-16                   76.79n ± 4%   73.42n ± 1%        ~ (p=0.007 n=15)
NatSqr/5-16                   99.00n ± 3%   95.35n ± 1%   -3.69% (p=0.000 n=15)
NatSqr/8-16                   160.0n ± 3%   155.1n ± 1%   -3.06% (p=0.001 n=15)
NatSqr/10-16                  178.4n ± 2%   175.9n ± 0%   -1.40% (p=0.001 n=15)
NatSqr/20-16                  361.9n ± 2%   361.3n ± 0%        ~ (p=0.083 n=15)
NatSqr/30-16                  584.7n ± 0%   586.8n ± 0%   +0.36% (p=0.000 n=15)
NatSqr/50-16                  1.327µ ± 0%   1.329µ ± 0%        ~ (p=0.349 n=15)
NatSqr/80-16                  2.893µ ± 1%   2.925µ ± 0%   +1.11% (p=0.000 n=15)
NatSqr/100-16                 4.330µ ± 1%   4.381µ ± 0%   +1.18% (p=0.000 n=15)
NatSqr/200-16                 16.25µ ± 1%   16.43µ ± 0%   +1.07% (p=0.000 n=15)
NatSqr/300-16                 27.85µ ± 1%   28.06µ ± 0%   +0.77% (p=0.000 n=15)
NatSqr/500-16                 76.01µ ± 0%   76.34µ ± 0%        ~ (p=0.002 n=15)
NatSqr/800-16                 146.8µ ± 0%   148.1µ ± 0%   +0.83% (p=0.000 n=15)
NatSqr/1000-16                228.2µ ± 0%   228.6µ ± 0%        ~ (p=0.123 n=15)
NatSqr/10000-16               7.524m ± 0%   7.426m ± 0%   -1.31% (p=0.000 n=15)
NatSqr/100000-16              316.7m ± 0%   309.2m ± 0%   -2.36% (p=0.000 n=15)
geomean                       7.264µ        7.172µ        -1.27%

goos: darwin
goarch: arm64
pkg: math/big
cpu: Apple M3 Pro
                            │     old     │                new                 │
                            │   sec/op    │   sec/op     vs base               │
GCD10x10/WithoutXY-12         32.61n ± 1%   32.42n ± 1%       ~ (p=0.021 n=15)
GCD10x10/WithXY-12            87.70n ± 1%   88.42n ± 1%       ~ (p=0.010 n=15)
GCD100x100/WithoutXY-12       305.9n ± 0%   306.4n ± 0%       ~ (p=0.003 n=15)
GCD100x100/WithXY-12          560.3n ± 2%   556.6n ± 1%       ~ (p=0.018 n=15)
GCD1000x1000/WithoutXY-12     3.509µ ± 2%   3.464µ ± 1%       ~ (p=0.145 n=15)
GCD1000x1000/WithXY-12        5.347µ ± 2%   5.372µ ± 1%       ~ (p=0.046 n=15)
GCD10000x10000/WithoutXY-12   73.75µ ± 1%   73.99µ ± 1%       ~ (p=0.004 n=15)
GCD10000x10000/WithXY-12      148.4µ ± 0%   147.8µ ± 1%       ~ (p=0.076 n=15)
Div/20/10-12                  9.481n ± 0%   9.462n ± 1%       ~ (p=0.631 n=15)
Div/40/20-12                  9.457n ± 0%   9.462n ± 1%       ~ (p=0.798 n=15)
Div/100/50-12                 14.91n ± 0%   14.79n ± 1%  -0.80% (p=0.000 n=15)
Div/200/100-12                84.56n ± 1%   84.60n ± 1%       ~ (p=0.271 n=15)
Div/400/200-12                103.8n ± 0%   102.8n ± 0%  -0.96% (p=0.000 n=15)
Div/1000/500-12               181.3n ± 1%   184.2n ± 2%       ~ (p=0.091 n=15)
Div/2000/1000-12              397.5n ± 0%   397.4n ± 0%       ~ (p=0.299 n=15)
Div/20000/10000-12            14.04µ ± 1%   13.99µ ± 0%       ~ (p=0.221 n=15)
Div/200000/100000-12          523.1µ ± 0%   514.0µ ± 3%       ~ (p=0.775 n=15)
Div/2000000/1000000-12        21.58m ± 0%   20.01m ± 1%  -7.29% (p=0.000 n=15)
Div/20000000/10000000-12      813.5m ± 0%   796.2m ± 1%  -2.13% (p=0.000 n=15)
NatMul/10-12                  80.46n ± 1%   80.02n ± 1%       ~ (p=0.063 n=15)
NatMul/100-12                 2.904µ ± 0%   2.979µ ± 1%  +2.58% (p=0.000 n=15)
NatMul/1000-12                127.8µ ± 0%   122.3µ ± 0%  -4.28% (p=0.000 n=15)
NatMul/10000-12               5.141m ± 0%   4.975m ± 1%  -3.23% (p=0.000 n=15)
NatMul/100000-12              208.8m ± 0%   189.6m ± 3%  -9.21% (p=0.000 n=15)
NatSqr/1-12                   11.90n ± 1%   11.76n ± 1%       ~ (p=0.059 n=15)
NatSqr/2-12                   21.33n ± 1%   21.12n ± 0%       ~ (p=0.063 n=15)
NatSqr/3-12                   26.05n ± 1%   25.79n ± 0%       ~ (p=0.002 n=15)
NatSqr/5-12                   37.31n ± 0%   36.98n ± 1%       ~ (p=0.008 n=15)
NatSqr/8-12                   63.07n ± 0%   62.75n ± 1%       ~ (p=0.061 n=15)
NatSqr/10-12                  79.48n ± 0%   79.59n ± 0%       ~ (p=0.455 n=15)
NatSqr/20-12                  173.1n ± 0%   173.2n ± 1%       ~ (p=0.518 n=15)
NatSqr/30-12                  288.6n ± 1%   289.2n ± 0%       ~ (p=0.030 n=15)
NatSqr/50-12                  653.3n ± 0%   653.3n ± 0%       ~ (p=0.361 n=15)
NatSqr/80-12                  1.492µ ± 0%   1.496µ ± 0%       ~ (p=0.018 n=15)
NatSqr/100-12                 2.270µ ± 1%   2.270µ ± 0%       ~ (p=0.326 n=15)
NatSqr/200-12                 8.776µ ± 1%   8.784µ ± 1%       ~ (p=0.083 n=15)
NatSqr/300-12                 15.07µ ± 0%   15.09µ ± 0%       ~ (p=0.455 n=15)
NatSqr/500-12                 41.71µ ± 0%   41.77µ ± 1%       ~ (p=0.305 n=15)
NatSqr/800-12                 80.77µ ± 1%   80.59µ ± 0%       ~ (p=0.113 n=15)
NatSqr/1000-12                126.4µ ± 1%   126.5µ ± 0%       ~ (p=0.683 n=15)
NatSqr/10000-12               4.204m ± 0%   4.119m ± 0%  -2.02% (p=0.000 n=15)
NatSqr/100000-12              177.0m ± 0%   172.9m ± 0%  -2.31% (p=0.000 n=15)
geomean                       3.790µ        3.757µ       -0.87%

Change-Id: Ifc7a9b61f678df216690511ac8bb9143189a795e
Reviewed-on: https://go-review.googlesource.com/c/go/+/652057
Auto-Submit: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>

cmd/compile: remove noDuffDevice

noDuffDevice was for Plan 9, but Plan 9 doesn't need it anymore.
It was also being set in s390x, mips, mipsle, and wasm, but
on those systems it had no effect since the SSA rules for those
architectures don't refer to it at all.

Change-Id: Ib85c0832674c714f3ad5091f0a022eb7cd3ebcdf
Reviewed-on: https://go-review.googlesource.com/c/go/+/655878
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>

cmd/compile: use FMA on plan9, and drop UseFMA

Every OS uses FMA now.

Change-Id: Ia7ffa77c52c45aefca611ddc54e9dfffb27a48da
Reviewed-on: https://go-review.googlesource.com/c/go/+/655877
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
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cmd/compile: remove useSSE

Every OS uses SSE now.

Change-Id: I4df7e2fbc8e5ccb1fc84a884d4c922b7a2a628e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/655876
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cmd/compile: compute bitsize from type size in prove to clean some switches

Change-Id: I215adda9050d214576433700aed4c371a36aaaed
Reviewed-on: https://go-review.googlesource.com/c/go/+/656335
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cmd/compile: add constant folding for bits.Add64

Change-Id: I0ed4ebeaaa68e274e5902485ccc1165c039440bd
Reviewed-on: https://go-review.googlesource.com/c/go/+/656275
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
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cmd/compile: add MakeTuple generic SSA op to remove duplicate Select[01] rules

Change-Id: Id94a5e503f02aa29dc1e334b521770107d4261db
Reviewed-on: https://go-review.googlesource.com/c/go/+/656615
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Reviewed-by: Keith Randall <khr@golang.org>
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cmd/compile: compute bits.OnesCount's limits from argument's limits

Change-Id: Ia90d48ea0fab363c8592221fad88958b522edefe
Reviewed-on: https://go-review.googlesource.com/c/go/+/656159
Reviewed-by: David Chase <drchase@google.com>
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runtime: increase GDB version testing requirement to 10 from 7.7

Bump the required version of GDB up to 10 from 7.7 in the runtime GDB
tests, so as to ensure that we have something that can handle DWARF 5
when running tests. In theory there is some DWARF 5 support on the
version 9 release branch, but we get "Dwarf Error: DW_FORM_addrx"
errors for some archs on builders where GDB 9.2 is installed.

Updates #26379.

Change-Id: I1b7b45f8e4dd1fafccf22f2dda0124458ecf7cba
Reviewed-on: https://go-review.googlesource.com/c/go/+/656836
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internal/buildcfg: fix typo in DWARF 5 enabling code

Fix a typo in the code that decides which GOOS values will support use
of DWARF 5 ("darwin" was not spelled correctly).

Updates #26379.

Change-Id: I3a7906d708550fcedc3a8e89d0444bf12b9143f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/656895
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cmd/compile: set bits.OnesCount's limits to [0, 64]

Change-Id: I2f60de836f58ef91baae856f44d8f73c190326f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/656158
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
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cmd/compile: use min & max builtins to assert constant bounds in prove's tests

I've originally used |= and &= to setup assumptions exploitable by the
operation under test but theses have multiple issues making it poor
for this usecase:
- &= does not pass the minimum value as-is, rather always set it to 0
- |= rounds up the max value to a number of the same length with all ones set
- I've never implemented them to work with negative signed numbers

Change-Id: Ie43c576fb10393e69d6f989b048823daa02b1df8
Reviewed-on: https://go-review.googlesource.com/c/go/+/656160
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cmd/compile: compute min's & max's limits from argument's limits inside flowLimit

Updates #68857

Change-Id: Ied07e656bba42f3b1b5f9b9f5442806aa2e7959b
Reviewed-on: https://go-review.googlesource.com/c/go/+/656157
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Reviewed-by: Keith Randall <khr@golang.org>
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internal/cpu: use correct variable when parsing CPU features lamcas and lam_bh on loong64

Change-Id: I5019f4e32243911f735f775bcb3c0dba5adb4162
Reviewed-on: https://go-review.googlesource.com/c/go/+/655395
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>
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cmd/internal/script/scripttest: use GOHOSTARCH to find tool directory

Fixes #72800

Change-Id: Idde7eae13d1c0098e5314935cf8ca823cbc7a7cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/656855
Auto-Submit: Ian Lance Taylor <iant@golang.org>
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internal/bytealg: optimize Count{,String} in loong64

Benchmark on Loongson 3A6000 and 3A5000:

goos: linux
goarch: loong64
pkg: bytes
cpu: Loongson-3A6000 @ 2500.00MHz
                |  bench.old   |              bench.new              |
                |    sec/op    |   sec/op     vs base                |
CountSingle/10    13.210n ± 0%   9.984n ± 0%  -24.42% (p=0.000 n=15)
CountSingle/32    31.970n ± 1%   7.205n ± 0%  -77.46% (p=0.000 n=15)
CountSingle/4K    4039.0n ± 0%   108.7n ± 0%  -97.31% (p=0.000 n=15)
CountSingle/4M    4158.9µ ± 0%   117.3µ ± 0%  -97.18% (p=0.000 n=15)
CountSingle/64M   68.641m ± 0%   2.585m ± 1%  -96.23% (p=0.000 n=15)
geomean            13.72µ        1.189µ       -91.34%

                |  bench.old   |                bench.new                 |
                |     B/s      |      B/s        vs base                  |
CountSingle/10    722.0Mi ± 0%     955.2Mi ± 0%    +32.30% (p=0.000 n=15)
CountSingle/32    954.6Mi ± 1%    4235.4Mi ± 0%   +343.68% (p=0.000 n=15)
CountSingle/4K    967.2Mi ± 0%   35947.6Mi ± 0%  +3616.64% (p=0.000 n=15)
CountSingle/4M    961.8Mi ± 0%   34092.7Mi ± 0%  +3444.71% (p=0.000 n=15)
CountSingle/64M   932.4Mi ± 0%   24757.2Mi ± 1%  +2555.24% (p=0.000 n=15)
geomean           902.2Mi          10.17Gi       +1054.77%

goos: linux
goarch: loong64
pkg: bytes
cpu: Loongson-3A5000 @ 2500.00MHz
                |  bench.old   |              bench.new               |
                |    sec/op    |    sec/op     vs base                |
CountSingle/10     14.41n ± 0%   12.81n ±  0%  -11.10% (p=0.000 n=15)
CountSingle/32    36.230n ± 0%   9.609n ±  0%  -73.48% (p=0.000 n=15)
CountSingle/4K    4366.0n ± 0%   165.5n ±  0%  -96.21% (p=0.000 n=15)
CountSingle/4M    4464.7µ ± 0%   325.2µ ±  0%  -92.72% (p=0.000 n=15)
CountSingle/64M   75.627m ± 0%   8.307m ± 69%  -89.02% (p=0.000 n=15)
geomean            15.04µ        2.229µ        -85.18%

                |  bench.old   |                 bench.new                 |
                |     B/s      |       B/s        vs base                  |
CountSingle/10    661.8Mi ± 0%     744.4Mi ±  0%    +12.49% (p=0.000 n=15)
CountSingle/32    842.4Mi ± 0%    3176.1Mi ±  0%   +277.03% (p=0.000 n=15)
CountSingle/4K    894.7Mi ± 0%   23596.7Mi ±  0%  +2537.34% (p=0.000 n=15)
CountSingle/4M    895.9Mi ± 0%   12299.7Mi ±  0%  +1272.88% (p=0.000 n=15)
CountSingle/64M   846.3Mi ± 0%    7703.9Mi ± 41%   +810.34% (p=0.000 n=15)
geomean           823.3Mi          5.424Gi         +574.68%

Change-Id: Ie07592beac61bdb093470c524049ed494df4d703
Reviewed-on: https://go-review.googlesource.com/c/go/+/586055
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
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internal/buildcfg: enable DWARF version 5 by default

This patch enables the DWARF version 5 experiment by default for most
platforms that support DWARF. Note that MacOS is kept at version 4,
due to problems with CGO builds; the "dsymutil" tool from older
versions of Xcode (prior to V16) can't handle DWARF5. Similar we keep
DWARF 4 for GOOS=aix, where XCOFF doesn't appear to support the new
section subtypes in DWARF 5.

Updates #26379.

Change-Id: I5edd600c611f03ce8e11be3ca18c1e6686ac74ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/637895
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cmp: add examples for Compare and Less

Change-Id: I6900f52736d5316ca523a213c65896861d855433
Reviewed-on: https://go-review.googlesource.com/c/go/+/656635
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archive/zip: error on ReadDir if there are invalid file names

Fixes #50179

Change-Id: I616a6d1279d025e345d2daa6d44b687c8a2d09e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/656495
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net/http: document Redirect behavior for non-ASCII characters

For #4385
For #72745

Change-Id: Ibd54fc03467eb948001299001bb2e2529512a7c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/656135
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all: move //go:debug decoratemappings=0 test to cmd/go

test/decoratemappingszero.go is intended to test that
//go:debug decoratemappings=0 disables annonations.

Unfortunately, //go:debug processing is handled by cmd/go, but
cmd/internal/testdir (which runs tests from test/) generally invokes the
compiler directly, thus it does not set default GODEBUGs.

Move this test to the cmd/go script tests, alongside the similar test
for language version.

Fixes #72772.

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