http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51258
--- Comment #11 from Uros Bizjak <ubizjak at gmail dot com> 2011-11-25 16:26:41 UTC --- I have additional patch that checks cpuid bit_CMPXCHG16B (and bit_CMPXCHG8B fwiw) for runtime support.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51258
--- Comment #11 from Uros Bizjak <ubizjak at gmail dot com> 2011-11-25 16:26:41 UTC --- I have additional patch that checks cpuid bit_CMPXCHG16B (and bit_CMPXCHG8B fwiw) for runtime support.