http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56068
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|WAITING |RESOLVED Resolution| |INVALID --- Comment #16 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-23 16:42:19 UTC --- mockbuild@centos6-64bit-builder ~/build/BUILD/tmp (mock-chroot) $ cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 6 model : 13 I think that's the old qemu bug of providing a non-sensical CPUID family/model/vendor combination by default on x86_64. AMD family 6 is 32bits only. Intel family 6 has 64bit support. You'll hit funny issues with GMP as well. Thus, fix your KVM/QEMU config.