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