diff options
| -rw-r--r-- | src/cpu.cpp | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/cpu.cpp b/src/cpu.cpp index 45b7faab4..b1d1c328f 100644 --- a/src/cpu.cpp +++ b/src/cpu.cpp @@ -96,9 +96,21 @@ void ottd_cpuid(int info[4], int type) #elif defined(__x86_64__) || defined(__i386) void ottd_cpuid(int info[4], int type) { + /* The easy variant would be just cpuid, however... ebx gets clobbered by PIC. */ __asm__ __volatile__ ( - "cpuid" - : "=a" (info[0]), "=b" (info[1]), "=c" (info[2]), "=d" (info[3]) +#if defined(__x86_64__) + "pushq %%rbx \n\t" // save %rbx +#else + "pushl %%ebx \n\t" // save %ebx +#endif + "cpuid \n\t" + "movl %%ebx, %1 \n\t" // write the result into output var +#if defined(__x86_64__) + "popq %%rbx \n\t" // restore %rbx +#else + "popl %%ebx \n\t" // restore %ebc +#endif + : "=a" (info[0]), "=r" (info[1]), "=c" (info[2]), "=d" (info[3]) : "a" (type) ); } |