http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46598
--- Comment #12 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-23 15:01:37 UTC --- The original testcase should just use __asm__ __volatile__("rdtsc":"=a"(havege_hardtick)::"dx"); everywhere. That fixes the original testcase for me.