http://bugs.gentoo.org/101627
--- Src/x86/ix86_cpudetect.c
+++ Src/x86/ix86_cpudetect.c
@@ -151,16 +151,18 @@
    }
 
    __asm__ __volatile__ (
+      "mov %%ebx, %%edi\n"
       "mov %4, %%eax\n"
       "cpuid\n"
       "mov %%eax, %0\n"
       "mov %%ebx, %1\n"
       "mov %%ecx, %2\n"
       "mov %%edx, %3\n"
+      "mov %%edi, %%ebx\n"
       : "=m" (regs[0]), "=m" (regs[1]),
         "=m" (regs[2]), "=m" (regs[3])
       : "m"(cmd)
-      : "eax", "ebx", "ecx", "edx"
+      : "eax", "ecx", "edx", "edi"
    );
 
    return 0;