http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51617
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-12-19 11:13:25 UTC --- That would require a global integer somewhere to count the threads, which would probably have to be kept forever to maintain ABI compatibility. If I had time to implement a temporary semi-intelligent fix then I'd rather just do it properly instead :)