| // Copyright 2020 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 arm64 |
| // +build darwin |
| // +build !ios |
| |
| package cpu |
| |
| func osInit() { |
| ARM64.HasATOMICS = sysctlEnabled([]byte("hw.optional.armv8_1_atomics\x00")) |
| ARM64.HasCRC32 = sysctlEnabled([]byte("hw.optional.armv8_crc32\x00")) |
| |
| // There are no hw.optional sysctl values for the below features on Mac OS 11.0 |
| // to detect their supported state dynamically. Assume the CPU features that |
| // Apple Silicon M1 supports to be available as a minimal set of features |
| // to all Go programs running on darwin/arm64. |
| ARM64.HasAES = true |
| ARM64.HasPMULL = true |
| ARM64.HasSHA1 = true |
| ARM64.HasSHA2 = true |
| } |
| |
| //go:noescape |
| func getsysctlbyname(name []byte) (int32, int32) |
| |
| func sysctlEnabled(name []byte) bool { |
| ret, value := getsysctlbyname(name) |
| if ret < 0 { |
| return false |
| } |
| return value > 0 |
| } |