| --- /usr/local/google/home/waffles/Downloads/C/CpuArch.c 2015-03-25 05:17:41.000000000 -0700 |
| +++ CpuArch.c 2016-02-19 12:42:20.327993932 -0800 |
| @@ -45,7 +45,8 @@ |
| "push %%EDX\n\t" |
| "popf\n\t" |
| "andl %%EAX, %0\n\t": |
| - "=c" (flag) : "c" (flag)); |
| + "=c" (flag) : "c" (flag): |
| + "%eax", "%edx" ); |
| #endif |
| return flag; |
| } |
| @@ -78,8 +79,17 @@ |
| |
| #else |
| |
| + // When built using GCC and -fPIC (until GCC 5.0), ebx points to the global |
| + // offset table, so the value must be preserved before executing cpuid. |
| + // Attempting to explicitly clobber ebx is a compile-time error. |
| __asm__ __volatile__ ( |
| - #if defined(MY_CPU_X86) && defined(__PIC__) |
| + #if defined(MY_CPU_AMD64) && defined(__PIC__) |
| + "mov %%rbx, %%rdi\n" |
| + "cpuid\n" |
| + "xchg %%rdi, %%rbx\n" |
| + : "=a" (*a) , |
| + "=D" (*b) , |
| + #elif defined(MY_CPU_X86) && defined(__PIC__) |
| "mov %%ebx, %%edi;" |
| "cpuid;" |
| "xchgl %%ebx, %%edi;" |
