Files
sys/cpu/cpu_gc_x86.s
Vaughn Iverson 8f2aa9fb48 cpu: conditionally re-enable AVX512 support on darwin/amd64
Darwin opmask clobbering bug was fixed in kernel version 21.3.0
as released in MacOS 12.2.0. This commit resolves issue by
checking for Darwin AVX512 support via a sysctl call with the
addition of a kernel minimum version check.

The kernel version check is completed without adding new
dependencies to x/sys/cpu. A sysctl call is accomplished by
copying a minimal amount of code from x/sys/unix, to retrieve
only the needed KERN_OSRELEASE value. This code is structured
in the same manner as an existing analogous AIX/PPC64 syscall.

The resulting dotted version string value is then parsed for
numeric comparison with a dependency free function.

All code in this contribution is structured to ease removal of
the special darwin/amd64 codepaths when that OS/arch combination
is eventually no longer supported by golang.

Resolves issue: golang/go#49233, reinstates fix for issue: golang/go#43089

Change-Id: I4755fc8b3865eb6562b0959ecc910e2c46ac6cb4
Reviewed-on: https://go-review.googlesource.com/c/sys/+/620256
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: vsivsi@yahoo.com <vsivsi@yahoo.com>
2024-11-04 23:17:32 +00:00

27 lines
602 B
ArmAsm

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (386 || amd64 || amd64p32) && gc
#include "textflag.h"
// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
TEXT ·cpuid(SB), NOSPLIT, $0-24
MOVL eaxArg+0(FP), AX
MOVL ecxArg+4(FP), CX
CPUID
MOVL AX, eax+8(FP)
MOVL BX, ebx+12(FP)
MOVL CX, ecx+16(FP)
MOVL DX, edx+20(FP)
RET
// func xgetbv() (eax, edx uint32)
TEXT ·xgetbv(SB), NOSPLIT, $0-8
MOVL $0, CX
XGETBV
MOVL AX, eax+0(FP)
MOVL DX, edx+4(FP)
RET