mirror of
https://github.com/golang/sys.git
synced 2026-01-29 07:02:06 +03:00
0cf7623e9d
The GODEBUG environment variable can be used to disable usage of specific processor features of Go programs that use the sys/cpu package. This is useful for testing and benchmarking different code paths that are guarded by sys/cpu variable checks. Use of processor features can not be enabled through GODEBUG. To disable usage of AVX and SSE41 cpu features on GOARCH amd64 use: GODEBUG=cpu.avx=off,cpu.sse41=off The special "all" option can be used to disable all options: GODEBUG=all=off This aligns the support of GODEBUG for sys/cpu with existing support for GODEBUG in the Go standard library package internal/cpu. Fixes golang/go#33963 Change-Id: I618b71af397bf06c57a49b2a300d032a16d05664 Reviewed-on: https://go-review.googlesource.com/c/sys/+/245237 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Martin Möhrmann <moehrmann@google.com> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
32 lines
776 B
Go
32 lines
776 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.
|
|
|
|
// +build linux
|
|
// +build ppc64 ppc64le
|
|
|
|
package cpu
|
|
|
|
// HWCAP/HWCAP2 bits. These are exposed by the kernel.
|
|
const (
|
|
// ISA Level
|
|
_PPC_FEATURE2_ARCH_2_07 = 0x80000000
|
|
_PPC_FEATURE2_ARCH_3_00 = 0x00800000
|
|
|
|
// CPU features
|
|
_PPC_FEATURE2_DARN = 0x00200000
|
|
_PPC_FEATURE2_SCV = 0x00100000
|
|
)
|
|
|
|
func doinit() {
|
|
// HWCAP2 feature bits
|
|
PPC64.IsPOWER8 = isSet(hwCap2, _PPC_FEATURE2_ARCH_2_07)
|
|
PPC64.IsPOWER9 = isSet(hwCap2, _PPC_FEATURE2_ARCH_3_00)
|
|
PPC64.HasDARN = isSet(hwCap2, _PPC_FEATURE2_DARN)
|
|
PPC64.HasSCV = isSet(hwCap2, _PPC_FEATURE2_SCV)
|
|
}
|
|
|
|
func isSet(hwc uint, value uint) bool {
|
|
return hwc&value != 0
|
|
}
|