math: rename Modf parameter int to integer

Avoid using int as a parameter name. Also, rename frac to
fractional for consistency.

Addresses comment on CL 694896:
https://go-review.googlesource.com/c/go/+/694896/comment/a9723a07_8352e3aa/

Change-Id: Icedeecf65ad2f51d4e8d5bcf6e64c0eae9885dec
Reviewed-on: https://go-review.googlesource.com/c/go/+/699035
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Reviewed-by: Michael Pratt <mpratt@google.com>
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Reviewed-by: Joel Sing <joel@sing.id.au>

runtime: use one more address bit for tagged pointers

We use one extra bit to placate systems which simulate amd64 binaries on
an arm64 host. Allocated arm64 addresses could be as high as 1<<48-1,
which would be invalid if we assumed 48-bit sign-extended addresses.

(Note that this does not help the other way around, simluating arm64
on amd64, but we don't have that problem at the moment.)

Fixes #69255

Change-Id: Iace17a5d41a65e34abf201d03d8b0ff6f7bf1150
Reviewed-on: https://go-review.googlesource.com/c/go/+/700515
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@google.com>
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cmd/dist: run racebench tests only in longtest mode

The racebench tests represent a significant portion of the race
builders' runtimes, but these tests aren't providing a lot of value.
Disable them and run them only on -longtest-race builders.

For #32032.

Change-Id: Ic4383c3f3b51d123ae9f5c377bc0e2ec02f2ddd7
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runtime: add comment for concatstring2

People always want to remove concatstring{2,3,4,5} for performance,
but we keep them to make the binary smaller. So, add a comment to
document why.

Updates #65020

Change-Id: I819976b700d45ce4d0846bf4481b2654b85708da
Reviewed-on: https://go-review.googlesource.com/c/go/+/700095
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go/doc: linkify interface methods

Create doc links for references to interface methods,
such as "[Context.Err]".

This does not attempt to handle embedded interfaces:
The linked-to method must be declared within the named type.

Fixes #54033

Change-Id: I4d7a132affe682c85958ca785bcc96571404e6c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/687395
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cmd/compile: use generated loops instead of DUFFZERO on loong64

Change-Id: Id43ee4353d4bac96627f8b0f54545cdd3d2a1d1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/699695
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cmd/internal/obj/loong64: add LDPTR.{W/D} and STPTR.{W/D} instructions support

Go asm syntax:
MOVWP 4(R4), R5
MOVVP 8(R4), R5
MOVWP R4, 12(R5)
MOVVP R4, 16(R5)

Equivalent platform assembler syntax:
ldptr.w r5, r4, $1
ldptr.d r5, r4, $2
stptr.w r4, r5, $3
stptr.d r4, r5, $4

Change-Id: I50a341cee2d875cb7c5da9db08b23799c9dc6c64
Reviewed-on: https://go-review.googlesource.com/c/go/+/699055
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internal/runtime/atomic: reset wrong jump target in Cas{,64} on loong64

The implementation here needs to be consistent with ssa.OpLOONG64LoweredAtomicCas{32,64},
which was ignored in CL 613396.

Change-Id: I72e8d2318e0c1935cc3a35ab5098f8a84e48bcd5
Reviewed-on: https://go-review.googlesource.com/c/go/+/699395
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net/http: skip redirecting in ServeMux when URL path for CONNECT is empty

In 1.21 ServeMux, we had a special-case to skip redirection when a given
path is empty for CONNECT requests:
https://go.googlesource.com/go/+/refs/tags/go1.24.4/src/net/http/servemux121.go#205.

This special case seems to not have been carried over to 1.22 ServeMux.
This causes needless redirection, which this CL fixes.

Fixes #74422

Change-Id: I3cc5b4d195ab0591a9139225b632cbe17f4290db
Reviewed-on: https://go-review.googlesource.com/c/go/+/699915
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runtime/race: add race detector support for linux/riscv64

This enables support for the race detector on linux/riscv64.

Fixes #64345

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cmd/cgo: split loadDWARF into two parts

The first part runs gcc to get the debug information, and the second
part processes the debug information. The first part doesn't touch the
global and package level information that's computed so we can run it
earlier and concurrently in a later CL.

For #75167

Change-Id: I6a6a6964769a47792892066d06c16f239f532858
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cmd/cgo: move typedefs and typedefList out of Package

Theyre moved into a new fileTypedefs type so we can better keep track of
their lifetime.

For #75167

Change-Id: I6a6a696491d00eb4b1cc56dfcb9e94ed53573a7a
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all: delete more windows/arm remnants

Updates #71671

Change-Id: I663c4a659ad45bcebfc03d6eb4783e5f5d3afa0d
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cmd/compile: remove sign extension before MULW on riscv64

These sign extensions aren't necessary.

Change-Id: Id68ea596a18b30949d4605b2885f02e49e42d8e1
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cmd/compile/internal/ssa: make oneBit function generic

Allows rewrite rules using oneBit to be made more compact.

Change-Id: I986715f77db5b548759d809fe668e1893048f25c
Reviewed-on: https://go-review.googlesource.com/c/go/+/699295
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internal/cpu: inline DebugOptions

internal/cpu.DebugOptions is only ever set in runtime.cpuinit on
unix-like platforms. DebugOptions itself is only used in
MustHaveDebugOptionsSupport, so inline the GOOS check there.

Change-Id: I6a35d6b8afcdadfc59585258002f53c20026116c
Reviewed-on: https://go-review.googlesource.com/c/go/+/699775
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net: update document on limitation of iprawsock on Windows

Fixed: #23209

Change-Id: I3bfe9f5192cbacf387386efda72f04eeec5ff3be
GitHub-Last-Rev: 660a62d139dda21fcaea1e95394ca38521c7f00a
GitHub-Pull-Request: golang/go#74857
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testing: allow specify temp dir by GOTMPDIR environment variable

Allow change the default temp directory returned by t.TempDir()
by environment variable GOTMPDIR.

Fixes #61585

Change-Id: Iba969bb02744e106cf15d80e0eda0245a55fc290
GitHub-Last-Rev: aeacea00952b11990b49a0fde6a0ce4fe910b777
GitHub-Pull-Request: golang/go#74844
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cmd/link: disallow linkname of runtime.addmoduledata

Although a comment on addmoduledata warns that it should not be
called from Go code, the linker still allow it to be accessed via
go:linkname. Using linkname on this function will cause a linker
crash when building with buildmode=plugin.

Fixes #75180

Change-Id: Ib72c367a8afaef712ca5e29b1d0a4fc98ed8f40f
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bytes, strings: speed up TrimSpace

This change lifts bounds checks out of loops in the TrimSpace functions,
among other micro-optimizations. Here are some benchmark results
(no change to allocations):

goos: darwin
goarch: amd64
pkg: bytes
cpu: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
                         │     old     │                 new                 │
                         │   sec/op    │   sec/op     vs base                │
TrimSpace/NoTrim-8         4.406n ± 0%   3.829n ± 1%  -13.11% (p=0.000 n=20)
TrimSpace/ASCII-8          7.688n ± 1%   5.872n ± 1%  -23.61% (p=0.000 n=20)
TrimSpace/SomeNonASCII-8   82.25n ± 1%   81.00n ± 1%   -1.51% (p=0.001 n=20)
TrimSpace/JustNonASCII-8   131.6n ± 8%   132.2n ± 1%        ~ (p=0.899 n=20)
geomean                    24.61n        22.15n        -9.99%

pkg: strings
                         │     old     │                 new                 │
                         │   sec/op    │   sec/op     vs base                │
TrimSpace/NoTrim-8         4.178n ± 0%   3.857n ± 2%   -7.68% (p=0.001 n=20)
TrimSpace/ASCII-8          7.708n ± 0%   5.585n ± 1%  -27.55% (p=0.000 n=20)
TrimSpace/SomeNonASCII-8   98.70n ± 1%   88.54n ± 1%  -10.30% (p=0.000 n=20)
TrimSpace/JustNonASCII-8   132.8n ± 2%   123.2n ± 0%   -7.16% (p=0.000 n=20)
geomean                    25.49n        22.02n       -13.61%

Change-Id: I523f03a909c82a51940b44c7b2634985b7447982
GitHub-Last-Rev: 35163f04c63ce2ef5e9e831c4371750504edb892
GitHub-Pull-Request: golang/go#75127
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testing/synctest: call out common issues with tests

While each point is explained their respective sections for Time,
Blocking, and Isolation, these appear to be the most common
issues worth calling out up front.

Fixes #75052

Change-Id: I916b559075ee4d1d23810a08459e037e21690193
Reviewed-on: https://go-review.googlesource.com/c/go/+/696736
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os,syscall: pass file flags to CreateFile on Windows

Add support for FILE_FLAG_* constants in the flag argument of
os.OpenFile and syscall.Open on Windows.

Passing invalid flags will result in an error.

Updates #73676

Change-Id: Ie215a3dd14f0d74141533f0a07865a02a67a3846
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crypto/tls: use hash.Cloner

A hash object needs to be cloned when doing certain steps in a
TLS 1.3 server handshake. It is more efficient to use the
hash.Cloner interface to clone a hash than to encode and decode
the hash object using the binary encoding interfaces.

We still need to support the binary encoding path in case the
hash objects come from the fips140 v1.0.0 module, given that
this module doesn't support the hash.Cloner interface.

Change-Id: I8425e14e481dcefafc9aa1e5bfd63b61c22675ad
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go/constant: fix complex != unknown comparison

By the contract of Compare, if one operand is Unknown, the result must be
false.

Fixes #75137

Change-Id: I56420fae808395f89769f5e5d448f9e1df9a622f
GitHub-Last-Rev: 858ba89a91bf966223975541af739ab0ab977075
GitHub-Pull-Request: golang/go#75140
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net: remove redundant cgoLookupCNAME return parameter

`completed bool` just means `err == nil` after CL 446179.

While here, add a test for cgoLookupCNAME.

Co-authored-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
Change-Id: I6081a089fde3cb27af4fbde6f04301fc3755272c
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net/http/httputil: remove redundant pw.Close() call in DumpRequestOut

pw.Close() is already deferred earlier in DumpRequestOut.

Change-Id: Icdc9366c816848ed0bb444022d2aa14e4ceaabac
GitHub-Last-Rev: 7c38f9f2b6a9535a9262c2c40c8f1f8754eba972
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time: skip TestLongAdjustTimers in short mode on single CPU systems

The OpenBSD armv7 port does not support SMP - on this platform the
TestLongAdjustTimers test passes in ~46 seconds on the openbsd/arm
builder when there is no other CPU contention, however it will almost
always fail when there is any other load.

Change-Id: Idf1c47b40376c749886843cdae11289c0984f714
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syscall: only get parent PID if SysProcAttr.Pdeathsig is set

The value of the parent PID is only used to check against get value
returned by getppid(2) in case SysProcAttr.Pdeathsig is non-zero. Avoid
the useless getpid(2) system call otherwise.

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Change-Id: If89f9c7acc82016ec359c79bd861d41460f42218
Reviewed-on: https://go-review.googlesource.com/c/go/+/699175
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Reviewed-by: Carlos Amedee <carlos@golang.org>

strings: remove redundant "runs" from string.Fields docstring

Change-Id: I502b24af186fc56fe953acf7ab7d29f8eefb9c07
GitHub-Last-Rev: 1a4edf431217d9c9ebf78f228926c297e51dd54a
GitHub-Pull-Request: golang/go#75156
Reviewed-on: https://go-review.googlesource.com/c/go/+/699215
Reviewed-by: Sean Liao <sean@liao.dev>
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net/textproto: eliminate some bounds checks

This change lifts bounds checks out of loops in the trim function.
Here are some benchmark results (no change to allocations):

goos: darwin
goarch: amd64
pkg: net/textproto
cpu: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
                                │     old     │                new                 │
                                │   sec/op    │   sec/op     vs base               │
ReadMIMEHeader/client_headers-8   3.531µ ± 3%   3.506µ ± 1%       ~ (p=0.068 n=20)
ReadMIMEHeader/server_headers-8   2.409µ ± 0%   2.384µ ± 1%  -1.02% (p=0.000 n=20)
Uncommon-8                        545.2n ± 1%   536.7n ± 0%  -1.58% (p=0.000 n=20)
geomean                           1.667µ        1.649µ       -1.10%

Change-Id: Ia6d4ac516497fd3521122ce9b97173a285b61e12
GitHub-Last-Rev: 580f35afceda1993da70a023ce5c28280bda1ff6
GitHub-Pull-Request: golang/go#75126
Reviewed-on: https://go-review.googlesource.com/c/go/+/698715
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Sean Liao <sean@liao.dev>
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os: return nil slice when ReadDir is used with a file on file_windows

ReadDir should return (nil, ENOTDIR) when the path points to a file
instead of a directory. That's the behavior on Unix systems, and it also
used to be the behavior on Windows. However, Windows currently returns
([]DirEntry{}, ENOTDIR).

We should change the implementation to match the expected behavior.

Fixed #75157

Change-Id: I3a3ddb71b5cd6e51dbca435a1585f01116844d4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/699375
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cmd/internal/obj/loong64: simplify buildop

The length of array optab is readily available, remove the sentinel and
sentinel scan, like arm64.

Change-Id: Iceeed22587ce2beeedeb5babdde3474e75d70f89
Reviewed-on: https://go-review.googlesource.com/c/go/+/699095
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
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Reviewed-by: Meidan Li <limeidan@loongson.cn>

debug/elf: don't panic if symtab too small

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

For #47653
Fixes #75130

Change-Id: Ie6015564bb98334377383bbc16d79119dc4e36f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/698855
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net/http: Ensure that CONNECT proxied requests respect MaxResponseHeaderBytes

Currently, CONNECT proxied requests use an unlimited Reader. As a
result, a malicious or misbehaving proxy server can send an unlimited
number of bytes to a client; causing the client to indefinitely receive bytes
until it runs out of memory.

To prevent this, we now use a LimitedReader that limits the number of
bytes according to MaxResponseHeaderBytes in Transport. If
MaxResponseHeaderBytes is not provided, we use the default value of 10
MB that has historically been used (see #26315).

Fixes #74633

Change-Id: I0b03bb354139dbc64318874402f7f29cc0fb42ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/698915
Reviewed-by: Damien Neil <dneil@google.com>
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net/http: require exact match for CrossSiteProtection bypass patterns

Fixes #75054
Fixes CVE-2025-47910

Change-Id: I6a6a696440c45c450d2cd681f418b01aa0422a60
Reviewed-on: https://go-review.googlesource.com/c/go/+/699275
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Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>

cmd/cgo: make it safe to run gcc in parallel

Use a new filename for each invocation so invocations run
concurrently don't overwrite the same file.

Change-Id: I6a6a696478b596a4819f41b3ac738263d41bbabf
Reviewed-on: https://go-review.googlesource.com/c/go/+/699017
Reviewed-by: Michael Matloob <matloob@google.com>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
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net: allow zero value destination address in WriteMsgUDPAddrPort

The existing address validity checks already cover both connected and
non-connected sockets. Pass a nil sockaddr just like WriteMsgUDP, when
the address is zero value.

TestWriteToUDP is extended to cover the netip APIs.

Fixes #74841

Change-Id: I2708e7747e224958198fe7abb3fcd8d59bc5a88a
Reviewed-on: https://go-review.googlesource.com/c/go/+/692437
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internall/poll: remove bufs field from Windows' poll.operation

The bufs field is used to avoid allocating it every time it is needed.
We can do better by using a sync.Pool to reuse allocations across
operations and FDs instead of the field.

A side benefit is that FD is now 16 bytes smaller and operation more
stateless.

Change-Id: I5d686d1526f6c63e7ca1ae84da1fbf2044b24703
Reviewed-on: https://go-review.googlesource.com/c/go/+/698798
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internal/poll: remove rsa field from Windows' poll.operation

The rsa field was added to the operation structure to avoid allocating
it every time it is needed. We can do better by using a sync.Pool to
reuse allocations across operations and FDs instead of the field.

A side benefit is that FD is now 16 bytes smaller and operation more
stateless.

Change-Id: I3b69a59e36b27f2cdd076cebd8d27a2a350b9c43
Reviewed-on: https://go-review.googlesource.com/c/go/+/698875
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syscall: sort Windows env block in StartProcess

Fixes #29530

Change-Id: Ia28c78274b9288bfa5de9ccb142a452d291a5b66
Reviewed-on: https://go-review.googlesource.com/c/go/+/694435
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
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internal/poll: don't use stack-allocated WSAMsg parameters

WSAMsg parameters should be passed to Windows as heap pointers instead
of stack pointers. This is because Windows might access the memory
after the syscall returned in case of a non-blocking operation (which
is the common case), and if the WSAMsg is on the stack, the Go
runtime might have moved it around.

Use a sync.Pool to cache WSAMsg structures to avoid a heap allocation
every time a WSAMsg is needed.

Fixes #74933

Cq-Include-Trybots: luci.golang.try:x_net-gotip-windows-amd64
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runtime: identify virtual memory layout for riscv64

Identify sv39, sv48 and sv57 based on the system stack address.
The current approach to memory allocation is less than ideal on
RISC-V hardware that is using sv39 mode. On sv39 we currently end
up doing around 85 mmap and 66 munmap, since we are trying to map
an unusable range. With this change we do 22 mmap and 0 munmap at
runtime initialisation.

This will also be necessary to support the race detector on sv39.

Updates #64345

Cq-Include-Trybots: luci.golang.try:gotip-linux-riscv64
Change-Id: I4f8ba6763b5ecfedfad5438e025d633820e8265c
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Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
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Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
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math: use Trunc to implement Modf

By implementing Modf using Trunc, rather than the other way round,
we can get a significant performance improvement on platforms where
Trunc is implemented as an intrinsic.

Trunc is implemented as an intrinsic on ppc64x and arm64 so the assembly
implementations of Modf are no longer needed (the compiler can generate
very similar code that can now potentially be inlined).

GOAMD64=v1

goos: linux
goarch: amd64
pkg: math
cpu: 12th Gen Intel(R) Core(TM) i7-12700T
        │       sec/op       │    sec/op     vs base                │
Gamma            4.257n ± 0%    3.890n ± 0%   -8.61% (p=0.000 n=10)
Modf            1.6110n ± 0%   0.4243n ± 0%  -73.67% (p=0.000 n=10)
geomean          2.619n         1.285n       -50.94%

GOAMD64=v2

goos: linux
goarch: amd64
pkg: math
cpu: 12th Gen Intel(R) Core(TM) i7-12700T
        │       sec/op       │    sec/op     vs base                │
Gamma            4.100n ± 1%    3.717n ± 0%   -9.35% (p=0.000 n=10)
Modf            1.6070n ± 0%   0.2158n ± 1%  -86.57% (p=0.000 n=10)
geomean          2.567n        0.8957n       -65.11%

Change-Id: I689a560c344cf1d39ef002b540749bacc3179786
Reviewed-on: https://go-review.googlesource.com/c/go/+/694896
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math: implement IsInf using Abs

Abs is an intrinsic (or a relatively cheap operation) on most
architectures. Using it in IsInf typically saves a branch when
`sign` is 0 (note the `sign` variable is typically a constant).

This change doesn't make a huge difference on amd64 (these
benchmarks are fairly noisy too) but removing the branch will
allow rewrite rules to detect and optimize infinity checks on
other architectures. For example, riscv64 can check for
infinities with the FCLASSD instruction and s390x can use the
TCDB instruction.

goos: linux
goarch: amd64
pkg: math
cpu: 12th Gen Intel(R) Core(TM) i7-12700T
                    │          sec/op          │    sec/op      vs base                │
Acos                              4.317n ±  1%    4.321n ±  0%        ~ (p=0.466 n=10)
Acosh                             8.857n ±  1%    8.411n ±  2%   -5.05% (p=0.001 n=10)
Asin                              4.260n ±  1%    4.204n ±  6%   -1.31% (p=0.021 n=10)
Asinh                             10.63n ±  2%    10.37n ±  0%   -2.49% (p=0.000 n=10)
Atan                              2.493n ±  1%    2.368n ±  0%   -5.01% (p=0.000 n=10)
Atanh                             8.820n ±  4%    8.770n ±  2%        ~ (p=0.579 n=10)
Atan2                             4.212n ±  1%    4.066n ± 11%   -3.45% (p=0.023 n=10)
Cbrt                              4.859n ±  0%    4.845n ±  0%   -0.29% (p=0.000 n=10)
Ceil                             0.3877n ±  3%   0.2514n ±  0%  -35.17% (p=0.000 n=10)
Copysign                         0.3479n ±  2%   0.4179n ±  0%  +20.14% (p=0.000 n=10)
Cos                               4.734n ±  2%    4.486n ±  0%   -5.26% (p=0.000 n=10)
Cosh                              5.244n ±  0%    5.071n ±  0%   -3.29% (p=0.000 n=10)
Erf                               2.975n ±  1%    2.788n ±  0%   -6.29% (p=0.000 n=10)
Erfc                              3.259n ±  1%    3.121n ±  0%   -4.23% (p=0.000 n=10)
Erfinv                            4.015n ±  1%    3.904n ±  0%   -2.76% (p=0.000 n=10)
Erfcinv                           4.166n ±  1%    4.039n ±  0%   -3.04% (p=0.000 n=10)
Exp                               3.567n ±  1%    3.429n ±  0%   -3.87% (p=0.000 n=10)
ExpGo                             9.173n ±  1%    8.368n ±  2%   -8.78% (p=0.000 n=10)
Expm1                             4.466n ±  3%    4.419n ±  0%   -1.05% (p=0.000 n=10)
Exp2                              8.328n ±  0%    8.046n ±  0%   -3.39% (p=0.000 n=10)
Exp2Go                            8.796n ±  5%    8.237n ±  2%   -6.36% (p=0.000 n=10)
Abs                              0.2400n ±  2%   0.2144n ±  0%  -10.71% (p=0.000 n=10)
Dim                              0.4077n ±  3%   0.3795n ±  1%   -6.91% (p=0.000 n=10)
Floor                            0.3616n ±  2%   0.2528n ±  3%  -30.10% (p=0.000 n=10)
Max                               1.401n ±  1%    1.344n ±  1%   -4.14% (p=0.000 n=10)
Min                               1.391n ±  1%    1.345n ±  1%   -3.27% (p=0.000 n=10)
Mod                               15.45n ±  1%    15.62n ±  2%        ~ (p=0.066 n=10)
Frexp                             1.838n ±  2%    1.605n ±  1%  -12.70% (p=0.000 n=10)
Gamma                             4.465n ±  1%    4.458n ±  1%        ~ (p=0.256 n=10)
Hypot                             2.237n ±  1%    2.208n ±  0%   -1.32% (p=0.000 n=10)
HypotGo                           2.610n ±  3%    2.663n ±  5%        ~ (p=0.280 n=10)
Ilogb                             1.793n ±  1%    1.566n ±  1%  -12.66% (p=0.000 n=10)
J0                                22.11n ±  1%    21.45n ±  1%   -2.99% (p=0.000 n=10)
J1                                21.71n ±  1%    21.38n ±  1%   -1.54% (p=0.000 n=10)
Jn                                46.43n ±  1%    45.83n ±  1%   -1.30% (p=0.001 n=10)
Ldexp                             2.360n ±  1%    2.111n ±  1%  -10.51% (p=0.000 n=10)
Lgamma                            4.728n ±  1%    4.850n ±  2%   +2.59% (p=0.000 n=10)
Log                               4.304n ±  2%    4.228n ±  1%   -1.78% (p=0.000 n=10)
Logb                              1.833n ±  2%    1.635n ±  2%  -10.80% (p=0.000 n=10)
Log1p                             5.262n ±  2%    5.173n ±  2%   -1.69% (p=0.001 n=10)
Log10                             4.534n ±  1%    4.474n ±  1%   -1.33% (p=0.024 n=10)
Log2                              2.510n ±  2%    2.246n ±  2%  -10.48% (p=0.000 n=10)
Modf                              1.712n ±  3%    1.700n ±  1%        ~ (p=0.055 n=10)
Nextafter32                       2.190n ±  3%    2.187n ±  0%        ~ (p=0.266 n=10)
Nextafter64                       2.184n ±  0%    2.183n ±  0%   -0.05% (p=0.017 n=10)
PowInt                            11.45n ±  7%    11.32n ±  9%        ~ (p=0.137 n=10)
PowFrac                           27.46n ±  3%    27.04n ±  1%   -1.55% (p=0.001 n=10)
Pow10Pos                         0.5367n ±  3%   0.5466n ±  2%   +1.84% (p=0.009 n=10)
Pow10Neg                         0.8939n ±  1%   0.8720n ±  2%   -2.45% (p=0.000 n=10)
Round                             1.218n ±  1%    1.198n ±  1%   -1.56% (p=0.005 n=10)
RoundToEven                       1.711n ±  0%    1.710n ±  0%        ~ (p=0.464 n=10)
Remainder                         12.87n ± 10%    13.79n ± 14%   +7.11% (p=0.027 n=10)
Signbit                          0.4072n ±  2%   0.3839n ±  2%   -5.71% (p=0.000 n=10)
Sin                               4.102n ±  1%    4.058n ±  3%        ~ (p=0.138 n=10)
Sincos                            5.837n ±  1%    5.715n ±  2%   -2.10% (p=0.000 n=10)
Sinh                              5.622n ±  1%    5.567n ±  2%   -0.96% (p=0.006 n=10)
SqrtIndirect                     0.4284n ±  0%   0.4279n ±  0%        ~ (p=0.084 n=10)
SqrtLatency                       2.779n ±  0%    2.777n ±  0%        ~ (p=0.089 n=10)
SqrtIndirectLatency               2.777n ±  0%    2.778n ±  0%        ~ (p=0.305 n=10)
SqrtGoLatency                     24.00n ±  0%    24.51n ±  0%   +2.12% (p=0.000 n=10)
SqrtPrime                         673.0n ±  0%    673.0n ±  0%        ~ (p=0.574 n=10)
Tan                               4.111n ±  4%    4.123n ±  5%        ~ (p=0.424 n=10)
Tanh                              5.787n ±  1%    5.723n ±  1%   -1.11% (p=0.010 n=10)
Trunc                            0.3441n ±  3%   0.2596n ±  2%  -24.56% (p=0.000 n=10)
Y0                                21.63n ±  2%    21.07n ±  2%   -2.61% (p=0.001 n=10)
Y1                                21.42n ±  1%    20.93n ±  3%   -2.29% (p=0.041 n=10)
Yn                                45.78n ±  1%    45.83n ±  1%        ~ (p=0.671 n=10)
Float64bits                      0.2187n ±  2%   0.2199n ±  2%        ~ (p=0.138 n=10)
Float64frombits                  0.2198n ±  1%   0.2199n ±  1%        ~ (p=0.956 n=10)
Float32bits                      0.2237n ±  2%   0.2213n ±  1%        ~ (p=0.060 n=10)
Float32frombits                  0.2251n ±  1%   0.2219n ±  2%   -1.42% (p=0.000 n=10)
FMA                              0.8557n ±  1%   0.8555n ±  0%        ~ (p=0.286 n=10)
geomean                           3.186n          3.070n         -3.61%

Change-Id: I4814bb1e3d9d20e9d8cd7689e8d5383e36b00331
Reviewed-on: https://go-review.googlesource.com/c/go/+/694955
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>

math: optimize Signbit implementation slightly

This small tweak to Signbit improves code generation on riscv64 and
possibly other architectures by removing the need to apply a 64 bit
mask.

Before:
  MOV $-9223372036854775808, X6
  AND X6, X5, X5
  SNEZ X5, X10

After:
  SLTI $0, X5, X10

This transformation could also be added to the optimization rules
but it is quite a special case.

goos: linux
goarch: riscv64
pkg: math
cpu: Spacemit(R) X60
        │    sec/op     │   sec/op     vs base                │
Signbit     13.05n ± 0%   11.42n ± 0%  -12.49% (p=0.000 n=10)

Change-Id: Ic218017c5bbb720ec24c6fe7cc230df539b2630c
Reviewed-on: https://go-review.googlesource.com/c/go/+/698419
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Florian Lehner <lehner.florian86@gmail.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>

cmd/compile/internal: optimizing add+sll rule using ALSLV instruction on loong64

Reduce the number of go toolchain instructions on loong64 as follows:

file     before after     Δ       %
go     1573148 1571708    -1,440  -0.0915%
gofmt     320578 320090    -488    -0.1522%
asm     555066 554406    -660    -0.1189%
cgo     481566 480926    -640    -0.1329%
compile     2475962 2473880    -2,082  -0.0841%
cover     516536 515920    -616    -0.1193%
link     702172 701404    -768    -0.1094%
preprofile  238626 238274    -352    -0.1475%
vet     792928 792100    -828    -0.1044%

Change-Id: I61e462726835959c60e1b4e5256d4020202418ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/693877
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: abner chenc <chenguoqi@loongson.cn>

runtime: skip doInit of plugins in runtime.main

Plugins may be loaded in the user's init code.
If loading fails, md.bad is true, and doInit should not be executed.
If loading succeeds, the plugin must run modulesinit and typelinksinit
before doInit. Here is not protected by pluginsMu, and in concurrent
scenarios it is possible to obtain the moduledata of the plugin that
is still in the loading process.
Any added modules after loop starts will do their own doInit calls.
This fixes the issue introduced by CL 520375.

Fixes #75102

Change-Id: I48e91ae21615a0c54176875a6a2dea8e1dade906
Reviewed-on: https://go-review.googlesource.com/c/go/+/697675
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Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

internal/trace: skip async preempt off tests on low end systems

The OpenBSD armv7 port does not support SMP - on this platform the
trace tests take ~300 seconds to run when async preempt is disabled,
which then times out on the builder. Skip these tests when run in
short mode on a single CPU system.

Change-Id: I9a697d5ba2b20652f76dcc97bd178a4ee8f1a2a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/698555
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Auto-Submit: Joel Sing <joel@sing.id.au>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>

net: fix cgoResSearch

CL 457439 mistakenly redeclared size inside the for loop, causing
cgoResSearch to always fail and fall back to goLookupCNAME.

Change-Id: I3e142d34287388284a8998ac13761b1e0c2911a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/696895
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
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os: set full name for Roots created with Root.OpenRoot

Set the Name for a Root created within a Root to be the
concatenation of the parent's path and the name used to open the child.

This matches the behavior for files opened within a Root
with Root.Open.

Fixes #73868

Change-Id: Idf4021602ac25556721b7ef6924dec652c7bf4db
Reviewed-on: https://go-review.googlesource.com/c/go/+/698376
Reviewed-by: Alan Donovan <adonovan@google.com>
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internal/poll: use fdMutex to provide read/write locking on Windows

On Windows it is not possible to do concurrent I/O on file handles due
to the way FD.Pread and FD.Pwrite are implemented. This serialization is
achieved by having a dedicated mutex locked in the affected FD methods.

This makes the code difficult to reason about, as there is another
layer of locking introduced by the fdMutex. For example, it is not
obvious that concurrent I/O operations are serialized.

This CL removed the dedicated mutex and uses the fdMutex to provide
read/write locking.

Change-Id: I00389662728ce29428a587c3189bab90a0399215
Reviewed-on: https://go-review.googlesource.com/c/go/+/698096
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Reviewed-by: Carlos Amedee <carlos@golang.org>

test/codegen: add Mul2 and DivPow2 test for loong64

Change-Id: I29ccd105c5418955146a3f4873162963da489a70
Reviewed-on: https://go-review.googlesource.com/c/go/+/697935
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Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>

test/codegen: add Mul* test for loong64

Change-Id: Ica285212e4884a96fe9738b53cdc789b223bf2e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/697895
Reviewed-by: David Chase <drchase@google.com>
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test/codegen: add sqrt* abs and copysign test for loong64

Change-Id: I645396fc4b00242f36a06f01550906805c0c1f73
Reviewed-on: https://go-review.googlesource.com/c/go/+/697955
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Reviewed-by: Carlos Amedee <carlos@golang.org>

net/http/httptest: redirect example.com requests to server

The default server cert used by NewServer already includes example.com
in its DNSNames, and by default, the client's RootCA configuration
means it won't trust a response from the real example.com.

Fixes #31054

Change-Id: I0686977e5ffe2c2f22f3fc09a47ee8ecc44765db
Reviewed-on: https://go-review.googlesource.com/c/go/+/666855
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
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internal/syscall/windows: increase internal Windows O_ flags values

The lowercase o_ flags are invented values. These conflict with
constants that will soon be allowed by os.OpenFile, which values will
be mandated by the Windows API. To avoid this overlap, the internal
values have been increased to the 33-63 bit range, as the Windows ones
are in the 0-32 bit range.

Updates #73676

Change-Id: I0f657f3ed3403de150f1730a5a65ae887a18a4e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/697363
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
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crypto/tls: fix quic comment typo

Change-Id: Ibd6b8d10ecac3cdea33de1218d516b7425443313
GitHub-Last-Rev: 3d5568ba087be71f21cf816c5edd9b8b8c629865
GitHub-Pull-Request: golang/go#75092
Reviewed-on: https://go-review.googlesource.com/c/go/+/697575
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Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Auto-Submit: Sean Liao <sean@liao.dev>

internal/poll: don't pass non-nil WSAMsg.Name with 0 namelen on windows

CL 692436 changed WriteMsgInet{4,6} on windows to pass a zero namelen
when the sockaddr is nil. Turns out Windows also requires name to be
nil when namelen is 0.

With this commit, WriteMsgInet4 and WriteMsgInet6 now nicely align with
WriteMsg.

For #74841

Change-Id: Ifadee2d12d9bce2411f11a0e12b9fa2b3d71990e
Reviewed-on: https://go-review.googlesource.com/c/go/+/698395
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Auto-Submit: Sean Liao <sean@liao.dev>
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Reviewed-by: Carlos Amedee <carlos@golang.org>
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runtime/metrics: improve doc

Polish a sentence by removing redundant "in response".

Change-Id: I232198ad904333f8eaa0c25a12824f0dcbf3cfb6
GitHub-Last-Rev: 421bfc03874f84a280e09bbd59d0bd074b4c9574
GitHub-Pull-Request: golang/go#72793
Reviewed-on: https://go-review.googlesource.com/c/go/+/656735
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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os: fix Root.MkdirAll to handle race of directory creation

No tests were added, because in order to reproduce, the directory would
have to be created precisely between the rootOpenDir and mkdirat calls,
which is impossible to do in a test.

Fixes #75114

Change-Id: I6f86a5b33c87452c35728318eaf2169a7534ef37
Reviewed-on: https://go-review.googlesource.com/c/go/+/698215
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Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Sean Liao <sean@liao.dev>

all: delete remaining windows/arm code

Fixes #43800
Updates #71671

Change-Id: Ib7aafe3a3f6ae48f23fa23f03103820e9fcf5161
Reviewed-on: https://go-review.googlesource.com/c/go/+/698415
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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cmd/asm: process forward jump to PCALIGN

The forward jump target are not processed when the target is PCALIGN, so
process it before emit nops for PCALIGN.

Fixes #74648

Change-Id: I690fbfacf79e26d7a37628a2551729b2381616c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/696915
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internal/poll: permit nil destination address in WriteMsg{Inet4,Inet6}

For #74841

Change-Id: If2ea23b1eb23e32680bd576f54a0020d7e115797
Reviewed-on: https://go-review.googlesource.com/c/go/+/692436
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runtime: remove remaining windows/arm files and comments

CL 648795 deleted most of windows/arm code, but some files escaped from
the purge.

This CL finishes the job.

For #71671

Change-Id: Id454c40a673a1a2a9f190d79248e6d56104cdd61
Reviewed-on: https://go-review.googlesource.com/c/go/+/698036
Reviewed-by: qiu laidongfeng <2645477756@qq.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
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cmd/compile: use zero register instead of specialized *zero instructions on loong64

Refer to CL 633075, loong64 has a zero(R0) register that can be used to do this.

Change-Id: I846c6bdfcfd6dbfa18338afc13e34e350580ead4
Reviewed-on: https://go-review.googlesource.com/c/go/+/693876
Reviewed-by: Carlos Amedee <carlos@golang.org>
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cmd/compile: simplify zerorange on loong64

Refer to CL 678936, we also did the same thing on loong64.

Change-Id: I156a9110a034878192f64baf8018115424aa5f0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/697957
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
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cmd/compile/internal/ssa: eliminate unnecessary extension operations

Reduce the number of go toolchain instructions on loong64 as follows:

file      before after      Δ        %
go      1598706 1597230    -1476    -0.0923%
gofmt      325180 324736    -444     -0.1365%
asm      562538 562098    -440     -0.0782%
cgo      488298 487634    -664     -0.1360%
compile      2504502 2503590    -912     -0.0364%
cover      525976 525312    -664     -0.1262%
link      714182 713226    -956     -0.1339%
preprofile   241308 240988    -320     -0.1326%
vet      794112 793316    -796     -0.1002%

Change-Id: I048ef79518b41e83c53da1a3a6b7edaca7cb63f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/693856
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>

cmd/compile: optimize some patterns into revb2h/revb4h instruction on loong64

Pattern1: (the type of c is uint16)
    c>>8 | c<<8
To:
    revb2h c

Pattern2: (the type of c is uint32)
    (c & 0xff00ff00)>>8 | (c & 0x00ff00ff)<<8
To:
    revb2h c

Pattern3: (the type of c is uint64)
    (c & 0xff00ff00ff00ff00)>>8 | (c & 0x00ff00ff00ff00ff)<<8
To:
    revb4h c

Change-Id: Ic6231a3f476cbacbea4bd00e31193d107cb86cda
Reviewed-on: https://go-review.googlesource.com/c/go/+/696335
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
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syscall: simplify execve handling on libc platforms

Rather than providing three different execve variables for different
platforms, use a single variable. Provide a small wrapper that handles
conversion to uintptr for the AIX/Solaris case.

Note that this removes special handling for openbsd/mips64, which is
now a dead port.

Updates #61546

Change-Id: I3d6387c31669f64bfb61639536803e595f478647
Reviewed-on: https://go-review.googlesource.com/c/go/+/693880
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: Carlos Amedee <carlos@golang.org>

cmd/compile: deduplication in the source code generated by mknode

Most types in the ir package don't have hidden children, so having
their doChildrenWithHidden and editChildrenWithHidden methods call
their own doChildren and editChildren methods can save a lot of
duplicate code.

Change-Id: Ib22a29d6a9a32855f3c3191ca2d26dff94ac556b
Reviewed-on: https://go-review.googlesource.com/c/go/+/697476
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
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cmd/compile: optimize rule (x + x) << c to x << c+1 on loong64

Change-Id: I782f93510bba92ba60b298c1c1cde456c8bcec38
Reviewed-on: https://go-review.googlesource.com/c/go/+/697956
Reviewed-by: Keith Randall <khr@google.com>
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cmd/internal/objabi,cmd/link: add support for additional riscv64 relocations

These additional relocation types are encountered when using the
Go race detector with riscv64.

Updates #64345

Change-Id: I6de6430165fb378463da1af9402198a3a31485ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/690496
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>

errors: mention Is/As in Join docs

Fixes #74461

Change-Id: Ic1b1b2b43d59dd67f31c2388ca88650ee847ba93
Reviewed-on: https://go-review.googlesource.com/c/go/+/696737
Reviewed-by: David Chase <drchase@google.com>
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cmd/go/internal/doc: pass URL fragments separately with -http

Plumb URL fragments separately when invoking pkgsite so the `#` doesn't
get %-encoded into the path.

Fixes: #75088
Change-Id: I33814fc6a192dff3e4f3d0b9d81205056dddd438
Reviewed-on: https://go-review.googlesource.com/c/go/+/697435
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Ian Alexander <jitsu@google.com>
Reviewed-by: Michael Matloob <matloob@google.com>
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Reviewed-by: Michael Matloob <matloob@golang.org>

internal/poll: don't call Seek for overlapped Windows handles

Overlapped handles don't have the file pointer updated when performing
I/O operations, so there is no need to call FD.Seek to reset the file
pointer.

Also, some overlapped file handles don't support seeking. See #74951.

Fixes #74951.

Change-Id: I0edd53beed7d3862730f3b2ed5fe9ba490e66c06
Reviewed-on: https://go-review.googlesource.com/c/go/+/697295
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internal/poll: set the correct file offset in FD.Seek for Windows overlapped handles

Windows doesn't keep the file pointer for overlapped file handles.
To work around this, we keep track of the current offset ourselves
and use it on every Read/Write operation.

When the user calls File.Seek with whence == io.SeekCurrent, it expects
that the offset we keep track of is also accounted for, else the
the seek'ed value won't match the file pointer seen by the user.

Updates #74951.
Fixes #75081.

Change-Id: Ieca7c3779e5349292883ffc293a8474088a4dec7
Reviewed-on: https://go-review.googlesource.com/c/go/+/697275
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runtime: save and restore all fcc registers in async preempt on loong64

Currently, all Op implementations on loong64 use fcc0 by default, so only
fcc0 is saved in CL 475577. However, fcc1-fcc7 may also be used by users
when writing assembly code, such as in CL 693878.

Change-Id: Idb60d8101a0f7d602dfcbbb39bd5da9f2c475bfd
Reviewed-on: https://go-review.googlesource.com/c/go/+/696875
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Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Reviewed-by: Carlos Amedee <carlos@golang.org>

cmd/go: document install outputs to $GOOS_$GOARCH when cross compiling

Fixes #74979

Change-Id: I2a93e3a78c953418cf62d93db107b9c8d25e8ed2
Reviewed-on: https://go-review.googlesource.com/c/go/+/696755
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unique: deflake TestCanonMap/LoadOrStore/ConcurrentUnsharedKeys

I do not know yet what's causing this flake, but I've debugged it enough
to be confident that it's not a serious issue; it seems to be a test
flake. There is some path through which the tree nodes or keys might
still be transiently reachable, but I don't yet know what that is.

Details about what I tried and ruled out are in the code.

For #74083.

Change-Id: I97cdaf3f97e8c543fcc2ccde8b7e682893ae2f97
Reviewed-on: https://go-review.googlesource.com/c/go/+/697341
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
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os: fix path in MkdirTemp error message

Fixes #75012

Change-Id: I9dd3ba8987bde9db93769a1b05d13b162ba5332d
Reviewed-on: https://go-review.googlesource.com/c/go/+/696715
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Sean Liao <sean@liao.dev>
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cmd/compile: tweak example command in README

While running ./src/all.bash, I got the following error:

all.bash must be run from $GOROOT/src

Change-Id: Iad271654ff8647501a324c282f01baf39605e3df
GitHub-Last-Rev: 2e289babf1bc81c1a44c9a72a29659d8bf9d827b
GitHub-Pull-Request: golang/go#75050
Reviewed-on: https://go-review.googlesource.com/c/go/+/696296
Reviewed-by: t hepudds <thepudds1460@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: Carlos Amedee <carlos@golang.org>

internal/trace: remove redundant info from Event.String

Remove redundant information from state transition events. They
currently mention the proc and goroutine id that is transitioning twice.

Also reorder the reason to appear after the from->to state transition
information since it is a detail that is not available for all
transition.

Before example:

M=6164541440 P=3 G=17 StateTransition Time=7169014471424 Resource=Goroutine(17) Reason="chan receive" GoID=17 Running->Waiting
M=6166261760 P=3 G=10 StateTransition Time=7169908799040 Resource=Proc(4) Reason="" ProcID=4 Idle->Idle

After example:

M=6164541440 P=3 G=17 StateTransition Time=7169014471424 GoID=17 Running->Waiting Reason="chan receive"
M=6166261760 P=3 G=10 StateTransition Time=7169908799040 ProcID=4 Idle->Idle Reason=""

Change-Id: I6a6a696487ff2905f7c98dae7e887b998a2cb298
Reviewed-on: https://go-review.googlesource.com/c/go/+/697356
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Reviewed-by: Carlos Amedee <carlos@golang.org>

cmd/compile/internal: make function comments match function names

Change-Id: I2ebadb87a4f60487c8f720930a72bc5ef953d7cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/696695
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
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Reviewed-by: Keith Randall <khr@google.com>
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internal/trace: use RFC3339Nano for wall clock snapshots in Event.String

Improve the quality of life for people who use go tool trace -d=parsed
to look at clock snapshot wall timestamps. Many use cases will benefit
from seing the timestamp in sub-second resolution.

Change-Id: I6a6a696403a2164db0c12789c764e22a5c519b1c
Reviewed-on: https://go-review.googlesource.com/c/go/+/697355
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Reviewed-by: Michael Knyszek <mknyszek@google.com>

syscall: forkAndExecInChild1: don't reuse pid variable

A named return variable pid is reused in a few places, and while
the code is not wrong, it is somewhat confusing.

This variable used to be called r1 before CL 456516 (which did the right
thing, but slightly added to the confusion).

Now, the code calling SYS_WRITE (initially added by CL 158298) never
checks the number of bytes written, so let's remove the assignment.

In the code that calls SYS_READ it is used, so let's use a different
variable, c, which seems less confusing.

All this hopefully makes the code more readable.

Change-Id: I0d7ec311615100deb7e0aa3f02384eadcc1b47e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/696835
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Stapelberg <stapelberg@google.com>
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Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
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cmd/go: use modern pprof flags in documentation

This change updates our mentions of pprof flags so that we now refer to
the modern flag names instead of the legacy ones.

Fixes #74336.

Change-Id: Ie8fbc7407178219b84ce5171fa5e94621129267e
Reviewed-on: https://go-review.googlesource.com/c/go/+/689095
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cmd/compile: ensure we use allowed registers for input-clobbering instructions

For instructions which clobber their input register, we make a second
copy of the input value so it is still available in a register for
future instructions.

That second copy might not respect the register input restrictions
for the instruction. So the second copy we make here can't actually
be used by the instruction - it should use the first copy, the second
copy is the one that will persist beyond the clobber.

Fixes #75063

Change-Id: I99acdc63f0c4e54567a174ff7ada601ae4e796b7
Reviewed-on: https://go-review.googlesource.com/c/go/+/697015
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runtime: fix comments in tracetype.go

They seem to have been copy and pasted from tracestack.go without being
updated.

Change-Id: I6a6a69645a778fe8e6e8a2f4a80429f20e90162e
Reviewed-on: https://go-review.googlesource.com/c/go/+/674215
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internal/trace: emit final sync event for generation in Go 1.26+

CL 693398 returned the error from reading a generation immediately, but
this is wrong -- a Sync event must be emitted to indicate the end of the
trace before reporting the error. This caused TestCrashWhileTracing
to fail because that test has a high likelihood of producing a truncated
trace, and it expects at least 2 Sync events. The truncated trace error
would be reported before the second Sync event, which is incorrect.

Fixes #75045.

Change-Id: Ia71592c4ec56a544afc85cdb7b575e143f80e048
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runtime: don't overwrite global stop channel in tests

This is used by TestStopTheWorldDeadlock, and the new
TestReadMetricsSched test accidentally modifies this global variable
instead of (as intended) defining a local one.

Change-Id: I7aaece83f285d051ad8b56b7591c76613c39613a
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internal/trace: add end-of-generation signal to trace

This change takes the EvEndOfGeneration event and promotes it to a real
event that appears in the trace.

This allows the trace parser to unambiguously identify truncated traces
vs. broken traces. It also makes a lot of the logic around parsing
simpler, because there's no more batch spilling necessary.

Fixes #73904.

Change-Id: I37c359b32b6b5f894825aafc02921adeaacf2595
Reviewed-on: https://go-review.googlesource.com/c/go/+/693398
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Reviewed-by: Michael Pratt <mpratt@google.com>
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net: skip TestIPv4WriteMsgUDPAddrPort on plan9

This test uses method (*UDPConn).WriteMsgUDPAddrPort, which is
not supported on Plan 9. The test needs to be skipped, like
for example TestAllocs which is already skipped for the
same reason.

Fixes #75017

Change-Id: Iaa0e6ecdba0938736d8f675fcac43c46db34cb5d
Reviewed-on: https://go-review.googlesource.com/c/go/+/696095
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runtime/metrics: add metric for current Go-owned thread count

Fixes #15490.

Change-Id: I6ce9edc46398030ff639e22d4ca4adebccdfe1b7
Reviewed-on: https://go-review.googlesource.com/c/go/+/690399
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runtime/metrics: add metric for total goroutines created

For #15490.

Change-Id: Ic587dda1f42d613ea131a6b53ce6ba6e6cadf4c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/690398
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runtime/metrics: add metrics for goroutine sched states

This is largely a port of CL 38180.

For #15490.

Change-Id: I2726111e472e81e9f9f0f294df97872c2689f061
Reviewed-on: https://go-review.googlesource.com/c/go/+/690397
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runtime: disable stack shrinking for all waiting-for-suspendG cases

Currently isShrinkStackSafe returns false if a goroutine is put into
_Gwaiting while it actually goes and executes on the system stack.
For a long time, we needed to be robust to the goroutine's stack
shrinking while we're executing on the system stack.

Unfortunately, this has become harder and harder to do over time. First,
the execution tracer might be invoked in these contexts and it may wish
to take a stack trace. We cannot take the stack trace if the garbage
collector might concurrently shrink the stack of the user goroutine we
want to trace. So, isShrinkStackSafe grew the condition that we wouldn't
try to shrink the stack in these cases if execution tracing was enabled.

Today, runtime.mutex may wish to take a stack trace for the mutex
profile, and it can happen in a very similar context. Taking the stack
trace is no longer safe.

This change takes the stance that we stop trying to make this work at
all, and instead guarantee that the stack won't move while we're in
these sensitive contexts.

Change-Id: Ibfad2d7a335ee97cecaa48001df0db9812deeab1
Reviewed-on: https://go-review.googlesource.com/c/go/+/692716
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runtime: remove duff support for amd64

Change-Id: I742b49a3889892b7b1bb354f47f1c0d933c041e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/682395
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

runtime: remove duff support for arm64

Change-Id: Ib290079a77a746a8512cd4638310b24164f6a930
Reviewed-on: https://go-review.googlesource.com/c/go/+/679456
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
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cmd/compile: use generated loops instead of DUFFCOPY on arm64

Change-Id: Ic2aa8959b7fc594b86def70b6c2be38badf7970c
Reviewed-on: https://go-review.googlesource.com/c/go/+/679015
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>

cmd/go: test barrier actions

Add a barrier action between test run action and it's dependencies.
Run will depend on this barrier action, and the barrier action will depend on:
1. The run action's dependencies
2. The previous barrier action

This will force internal/work to schedule test run actions in-order, preventing potential goroutine starvation from
the channel locking mechanism created to force test run actions to start in-order.

Fixes #73106 #61233

Change-Id: I72e9f752f7521093f3c875eef7f2f29b2393fce9
Reviewed-on: https://go-review.googlesource.com/c/go/+/668035
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Matloob <matloob@google.com>