// 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 386 amd64 amd64p32 package cpu const cacheLineSize = 64 func init() { maxID, _, _, _ := cpuid(0, 0) if maxID < 1 { return } _, _, ecx1, edx1 := cpuid(1, 0) X86.HasSSE2 = isSet(26, edx1) X86.HasSSE3 = isSet(0, ecx1) X86.HasPCLMULQDQ = isSet(1, ecx1) X86.HasSSSE3 = isSet(9, ecx1) X86.HasFMA = isSet(12, ecx1) X86.HasSSE41 = isSet(19, ecx1) X86.HasSSE42 = isSet(20, ecx1) X86.HasPOPCNT = isSet(23, ecx1) X86.HasAES = isSet(25, ecx1) X86.HasOSXSAVE = isSet(27, ecx1) X86.HasRDRAND = isSet(30, ecx1) osSupportsAVX := false // For XGETBV, OSXSAVE bit is required and sufficient. if X86.HasOSXSAVE { eax, _ := xgetbv() // Check if XMM and YMM registers have OS support. osSupportsAVX = isSet(1, eax) && isSet(2, eax) } X86.HasAVX = isSet(28, ecx1) && osSupportsAVX if maxID < 7 { return } _, ebx7, _, _ := cpuid(7, 0) X86.HasBMI1 = isSet(3, ebx7) X86.HasAVX2 = isSet(5, ebx7) && osSupportsAVX X86.HasBMI2 = isSet(8, ebx7) X86.HasERMS = isSet(9, ebx7) X86.HasRDSEED = isSet(18, ebx7) X86.HasADX = isSet(19, ebx7) } func isSet(bitpos uint, value uint32) bool { return value&(1<<bitpos) != 0 }