mirror of
https://github.com/octoleo/syncthing.git
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60 lines
1.3 KiB
Go
60 lines
1.3 KiB
Go
// Copyright 2017 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build 386 amd64 amd64p32
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package cpufeat
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const CacheLineSize = 64
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// cpuid is implemented in cpu_x86.s.
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func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
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// xgetbv with ecx = 0 is implemented in cpu_x86.s.
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func xgetbv() (eax, edx uint32)
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func init() {
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maxId, _, _, _ := cpuid(0, 0)
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if maxId < 1 {
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return
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}
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_, _, ecx1, edx1 := cpuid(1, 0)
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X86.HasSSE2 = isSet(26, edx1)
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X86.HasSSE3 = isSet(0, ecx1)
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X86.HasPCLMULQDQ = isSet(1, ecx1)
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X86.HasSSSE3 = isSet(9, ecx1)
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X86.HasSSE41 = isSet(19, ecx1)
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X86.HasSSE42 = isSet(20, ecx1)
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X86.HasPOPCNT = isSet(23, ecx1)
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X86.HasAES = isSet(25, ecx1)
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X86.HasOSXSAVE = isSet(27, ecx1)
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osSupportsAVX := false
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// For XGETBV, OSXSAVE bit is required and sufficient.
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if X86.HasOSXSAVE {
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eax, _ := xgetbv()
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// Check if XMM and YMM registers have OS support.
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osSupportsAVX = isSet(1, eax) && isSet(2, eax)
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}
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X86.HasAVX = isSet(28, ecx1) && osSupportsAVX
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if maxId < 7 {
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return
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}
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_, ebx7, _, _ := cpuid(7, 0)
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X86.HasBMI1 = isSet(3, ebx7)
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X86.HasAVX2 = isSet(5, ebx7) && osSupportsAVX
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X86.HasBMI2 = isSet(8, ebx7)
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X86.HasERMS = isSet(9, ebx7)
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}
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func isSet(bitpos uint, value uint32) bool {
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return value&(1<<bitpos) != 0
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}
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