1// Copyright 2018 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// +build 386 amd64 amd64p32 6 7package cpu 8 9const cacheLineSize = 64 10 11func init() { 12 Initialized = true 13 14 maxID, _, _, _ := cpuid(0, 0) 15 16 if maxID < 1 { 17 return 18 } 19 20 _, _, ecx1, edx1 := cpuid(1, 0) 21 X86.HasSSE2 = isSet(26, edx1) 22 23 X86.HasSSE3 = isSet(0, ecx1) 24 X86.HasPCLMULQDQ = isSet(1, ecx1) 25 X86.HasSSSE3 = isSet(9, ecx1) 26 X86.HasFMA = isSet(12, ecx1) 27 X86.HasSSE41 = isSet(19, ecx1) 28 X86.HasSSE42 = isSet(20, ecx1) 29 X86.HasPOPCNT = isSet(23, ecx1) 30 X86.HasAES = isSet(25, ecx1) 31 X86.HasOSXSAVE = isSet(27, ecx1) 32 X86.HasRDRAND = isSet(30, ecx1) 33 34 osSupportsAVX := false 35 // For XGETBV, OSXSAVE bit is required and sufficient. 36 if X86.HasOSXSAVE { 37 eax, _ := xgetbv() 38 // Check if XMM and YMM registers have OS support. 39 osSupportsAVX = isSet(1, eax) && isSet(2, eax) 40 } 41 42 X86.HasAVX = isSet(28, ecx1) && osSupportsAVX 43 44 if maxID < 7 { 45 return 46 } 47 48 _, ebx7, _, _ := cpuid(7, 0) 49 X86.HasBMI1 = isSet(3, ebx7) 50 X86.HasAVX2 = isSet(5, ebx7) && osSupportsAVX 51 X86.HasBMI2 = isSet(8, ebx7) 52 X86.HasERMS = isSet(9, ebx7) 53 X86.HasRDSEED = isSet(18, ebx7) 54 X86.HasADX = isSet(19, ebx7) 55} 56 57func isSet(bitpos uint, value uint32) bool { 58 return value&(1<<bitpos) != 0 59} 60