| // Copyright 2017 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 |
| |
| // cpuid is implemented in cpu_x86.s. |
| func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32) |
| |
| // xgetbv with ecx = 0 is implemented in cpu_x86.s. |
| func xgetbv() (eax, edx uint32) |
| |
| const ( |
| // edx bits |
| cpuid_SSE2 = 1 << 26 |
| |
| // ecx bits |
| cpuid_SSE3 = 1 << 0 |
| cpuid_PCLMULQDQ = 1 << 1 |
| cpuid_SSSE3 = 1 << 9 |
| cpuid_FMA = 1 << 12 |
| cpuid_SSE41 = 1 << 19 |
| cpuid_SSE42 = 1 << 20 |
| cpuid_POPCNT = 1 << 23 |
| cpuid_AES = 1 << 25 |
| cpuid_OSXSAVE = 1 << 27 |
| cpuid_AVX = 1 << 28 |
| |
| // ebx bits |
| cpuid_BMI1 = 1 << 3 |
| cpuid_AVX2 = 1 << 5 |
| cpuid_BMI2 = 1 << 8 |
| cpuid_ERMS = 1 << 9 |
| cpuid_ADX = 1 << 19 |
| ) |
| |
| func doinit() { |
| maxID, _, _, _ := cpuid(0, 0) |
| |
| if maxID < 1 { |
| return |
| } |
| |
| _, _, ecx1, edx1 := cpuid(1, 0) |
| X86.HasSSE2 = isSet(edx1, cpuid_SSE2) |
| |
| X86.HasSSE3 = isSet(ecx1, cpuid_SSE3) |
| X86.HasPCLMULQDQ = isSet(ecx1, cpuid_PCLMULQDQ) |
| X86.HasSSSE3 = isSet(ecx1, cpuid_SSSE3) |
| X86.HasFMA = isSet(ecx1, cpuid_FMA) |
| X86.HasSSE41 = isSet(ecx1, cpuid_SSE41) |
| X86.HasSSE42 = isSet(ecx1, cpuid_SSE42) |
| X86.HasPOPCNT = isSet(ecx1, cpuid_POPCNT) |
| X86.HasAES = isSet(ecx1, cpuid_AES) |
| X86.HasOSXSAVE = isSet(ecx1, cpuid_OSXSAVE) |
| |
| 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(eax, 1<<1) && isSet(eax, 1<<2) |
| } |
| |
| X86.HasAVX = isSet(ecx1, cpuid_AVX) && osSupportsAVX |
| |
| if maxID < 7 { |
| return |
| } |
| |
| _, ebx7, _, _ := cpuid(7, 0) |
| X86.HasBMI1 = isSet(ebx7, cpuid_BMI1) |
| X86.HasAVX2 = isSet(ebx7, cpuid_AVX2) && osSupportsAVX |
| X86.HasBMI2 = isSet(ebx7, cpuid_BMI2) |
| X86.HasERMS = isSet(ebx7, cpuid_ERMS) |
| X86.HasADX = isSet(ebx7, cpuid_ADX) |
| } |
| |
| func isSet(hwc uint32, value uint32) bool { |
| return hwc&value != 0 |
| } |
