Files
sys/cpu/cpu_gc_x86.go
Vaughn Iverson b677753862 cpu: fix AVX512 support detection on Darwin
Summary: On darwin/amd64, it is not adequate to use OSXSAVE
bits to determine AVX512 availabilty. The reason is involved.
See github issue for details.

The fix consists of implementing Apple's recommended approach
using the process commpage cpu_capabilities bits to determine
availability of AVX512.

Fixes golang/go#43089

Change-Id: I1ba89965498863d268fbf2e427dbfd6429c7409f
Reviewed-on: https://go-review.googlesource.com/c/sys/+/285572
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
2021-05-03 07:37:44 +00:00

22 lines
681 B
Go

// 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
// +build 386 amd64 amd64p32
// +build gc
package cpu
// cpuid is implemented in cpu_x86.s for gc compiler
// and in cpu_gccgo.c for gccgo.
func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
// xgetbv with ecx = 0 is implemented in cpu_x86.s for gc compiler
// and in cpu_gccgo.c for gccgo.
func xgetbv() (eax, edx uint32)
// darwinSupportsAVX512 is implemented in cpu_x86.s for gc compiler
// and in cpu_gccgo_x86.go for gccgo.
func darwinSupportsAVX512() bool