diff --git a/cpu/cpu_gc_x86.go b/cpu/cpu_gc_x86.go index fa7cdb9b..3298a87e 100644 --- a/cpu/cpu_gc_x86.go +++ b/cpu/cpu_gc_x86.go @@ -15,3 +15,7 @@ func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32) // xgetbv with ecx = 0 is implemented in cpu_x86.s for gc compiler // and in cpu_gccgo.c for gccgo. func xgetbv() (eax, edx uint32) + +// darwinSupportsAVX512 is implemented in cpu_x86.s for gc compiler +// and in cpu_gccgo_x86.go for gccgo. +func darwinSupportsAVX512() bool diff --git a/cpu/cpu_gccgo_x86.go b/cpu/cpu_gccgo_x86.go index 8478a6d5..863d415a 100644 --- a/cpu/cpu_gccgo_x86.go +++ b/cpu/cpu_gccgo_x86.go @@ -25,3 +25,9 @@ func xgetbv() (eax, edx uint32) { gccgoXgetbv(&a, &d) return a, d } + +// gccgo doesn't build on Darwin, per: +// https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/gcc.rb#L76 +func darwinSupportsAVX512() bool { + return false +} diff --git a/cpu/cpu_x86.go b/cpu/cpu_x86.go index fd380c0a..54ca4667 100644 --- a/cpu/cpu_x86.go +++ b/cpu/cpu_x86.go @@ -87,8 +87,14 @@ func archInit() { // Check if XMM and YMM registers have OS support. osSupportsAVX = isSet(1, eax) && isSet(2, eax) - // Check if OPMASK and ZMM registers have OS support. - osSupportsAVX512 = osSupportsAVX && isSet(5, eax) && isSet(6, eax) && isSet(7, eax) + if runtime.GOOS == "darwin" { + // Check darwin commpage for AVX512 support. Necessary because: + // https://github.com/apple/darwin-xnu/blob/0a798f6738bc1db01281fc08ae024145e84df927/osfmk/i386/fpu.c#L175-L201 + osSupportsAVX512 = osSupportsAVX && darwinSupportsAVX512() + } else { + // Check if OPMASK and ZMM registers have OS support. + osSupportsAVX512 = osSupportsAVX && isSet(5, eax) && isSet(6, eax) && isSet(7, eax) + } } X86.HasAVX = isSet(28, ecx1) && osSupportsAVX diff --git a/cpu/cpu_x86.s b/cpu/cpu_x86.s index 39acab2f..b748ba52 100644 --- a/cpu/cpu_x86.s +++ b/cpu/cpu_x86.s @@ -26,3 +26,27 @@ TEXT ·xgetbv(SB),NOSPLIT,$0-8 MOVL AX, eax+0(FP) MOVL DX, edx+4(FP) RET + +// func darwinSupportsAVX512() bool +TEXT ·darwinSupportsAVX512(SB), NOSPLIT, $0-1 + MOVB $0, ret+0(FP) // default to false +#ifdef GOOS_darwin // return if not darwin +#ifdef GOARCH_amd64 // return if not amd64 +// These values from: +// https://github.com/apple/darwin-xnu/blob/xnu-4570.1.46/osfmk/i386/cpu_capabilities.h +#define commpage64_base_address 0x00007fffffe00000 +#define commpage64_cpu_capabilities64 (commpage64_base_address+0x010) +#define commpage64_version (commpage64_base_address+0x01E) +#define hasAVX512F 0x0000004000000000 + MOVQ $commpage64_version, BX + CMPW (BX), $13 // cpu_capabilities64 undefined in versions < 13 + JL no_avx512 + MOVQ $commpage64_cpu_capabilities64, BX + MOVQ $hasAVX512F, CX + TESTQ (BX), CX + JZ no_avx512 + MOVB $1, ret+0(FP) +no_avx512: +#endif +#endif + RET