cpuid_amd64.s raw

   1  // Copyright (c) 2015 Klaus Post, released under MIT License. See LICENSE file.
   2  
   3  //+build amd64,!gccgo,!noasm,!appengine
   4  
   5  // func asmCpuid(op uint32) (eax, ebx, ecx, edx uint32)
   6  TEXT ·asmCpuid(SB), 7, $0
   7  	XORQ CX, CX
   8  	MOVL op+0(FP), AX
   9  	CPUID
  10  	MOVL AX, eax+8(FP)
  11  	MOVL BX, ebx+12(FP)
  12  	MOVL CX, ecx+16(FP)
  13  	MOVL DX, edx+20(FP)
  14  	RET
  15  
  16  // func asmCpuidex(op, op2 uint32) (eax, ebx, ecx, edx uint32)
  17  TEXT ·asmCpuidex(SB), 7, $0
  18  	MOVL op+0(FP), AX
  19  	MOVL op2+4(FP), CX
  20  	CPUID
  21  	MOVL AX, eax+8(FP)
  22  	MOVL BX, ebx+12(FP)
  23  	MOVL CX, ecx+16(FP)
  24  	MOVL DX, edx+20(FP)
  25  	RET
  26  
  27  // func asmXgetbv(index uint32) (eax, edx uint32)
  28  TEXT ·asmXgetbv(SB), 7, $0
  29  	MOVL index+0(FP), CX
  30  	BYTE $0x0f; BYTE $0x01; BYTE $0xd0 // XGETBV
  31  	MOVL AX, eax+8(FP)
  32  	MOVL DX, edx+12(FP)
  33  	RET
  34  
  35  // func asmRdtscpAsm() (eax, ebx, ecx, edx uint32)
  36  TEXT ·asmRdtscpAsm(SB), 7, $0
  37  	BYTE $0x0F; BYTE $0x01; BYTE $0xF9 // RDTSCP
  38  	MOVL AX, eax+0(FP)
  39  	MOVL BX, ebx+4(FP)
  40  	MOVL CX, ecx+8(FP)
  41  	MOVL DX, edx+12(FP)
  42  	RET
  43  
  44  // From https://go-review.googlesource.com/c/sys/+/285572/
  45  // func asmDarwinHasAVX512() bool
  46  TEXT ·asmDarwinHasAVX512(SB), 7, $0-1
  47  	MOVB $0, ret+0(FP) // default to false
  48  
  49  #ifdef GOOS_darwin // return if not darwin
  50  #ifdef GOARCH_amd64 // return if not amd64
  51  // These values from:
  52  // https://github.com/apple/darwin-xnu/blob/xnu-4570.1.46/osfmk/i386/cpu_capabilities.h
  53  #define commpage64_base_address         0x00007fffffe00000
  54  #define commpage64_cpu_capabilities64   (commpage64_base_address+0x010)
  55  #define commpage64_version              (commpage64_base_address+0x01E)
  56  #define hasAVX512F                      0x0000004000000000
  57  	MOVQ $commpage64_version, BX
  58  	MOVW (BX), AX
  59  	CMPW AX, $13                            // versions < 13 do not support AVX512
  60  	JL   no_avx512
  61  	MOVQ $commpage64_cpu_capabilities64, BX
  62  	MOVQ (BX), AX
  63  	MOVQ $hasAVX512F, CX
  64  	ANDQ CX, AX
  65  	JZ   no_avx512
  66  	MOVB $1, ret+0(FP)
  67  
  68  no_avx512:
  69  #endif
  70  #endif
  71  	RET
  72  
  73