// cpuid is implemented in cpu_x86.s for gc compiler // and in cpu_gccgo.c for gccgo. 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)