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//go:build (386 || amd64 || amd64p32) && gc
6// +build 386 amd64 amd64p32
7// +build gc
8
9#include "textflag.h"
10
11// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
12TEXT ·cpuid(SB), NOSPLIT, $0-24
13	MOVL eaxArg+0(FP), AX
14	MOVL ecxArg+4(FP), CX
15	CPUID
16	MOVL AX, eax+8(FP)
17	MOVL BX, ebx+12(FP)
18	MOVL CX, ecx+16(FP)
19	MOVL DX, edx+20(FP)
20	RET
21
22// func xgetbv() (eax, edx uint32)
23TEXT ·xgetbv(SB),NOSPLIT,$0-8
24	MOVL $0, CX
25	XGETBV
26	MOVL AX, eax+0(FP)
27	MOVL DX, edx+4(FP)
28	RET
29
30// func darwinSupportsAVX512() bool
31TEXT ·darwinSupportsAVX512(SB), NOSPLIT, $0-1
32    MOVB    $0, ret+0(FP) // default to false
33#ifdef GOOS_darwin   // return if not darwin
34#ifdef GOARCH_amd64  // return if not amd64
35// These values from:
36// https://github.com/apple/darwin-xnu/blob/xnu-4570.1.46/osfmk/i386/cpu_capabilities.h
37#define commpage64_base_address         0x00007fffffe00000
38#define commpage64_cpu_capabilities64   (commpage64_base_address+0x010)
39#define commpage64_version              (commpage64_base_address+0x01E)
40#define hasAVX512F                      0x0000004000000000
41    MOVQ    $commpage64_version, BX
42    CMPW    (BX), $13  // cpu_capabilities64 undefined in versions < 13
43    JL      no_avx512
44    MOVQ    $commpage64_cpu_capabilities64, BX
45    MOVQ    $hasAVX512F, CX
46    TESTQ   (BX), CX
47    JZ      no_avx512
48    MOVB    $1, ret+0(FP)
49no_avx512:
50#endif
51#endif
52    RET
53