http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39753
--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-15 11:49:12 UTC --- The easiest way is to attach the may_alias attribute to all object types that should not be subject to TBAA. Bonus point if you transition that attribute to use a flag instead.