https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107551
Martin Liška <marxin at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |marxin at gcc dot gnu.org Assignee|unassigned at gcc dot gnu.org |marxin at gcc dot gnu.org --- Comment #7 from Martin Liška <marxin at gcc dot gnu.org> --- Can you please run: $ cat cpuid.c #include "cpuid.h" int main() { int eax, ebx, ecx, edx; __get_cpuid (0, &eax, &ebx, &ecx, &edx); __builtin_printf ("__get_cpuid(0): eax=%#x, ebx=%#x, ecx=%#x, edx=%#x\n", eax, ebx, ecx, edx); __get_cpuid (1, &eax, &ebx, &ecx, &edx); __builtin_printf ("__get_cpuid(1): eax=%#x, ebx=%#x, ecx=%#x, edx=%#x\n", eax, ebx, ecx, edx); } $ gcc cpuid.c && ./a.out And paste here the output?