http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46217
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-29 13:03:07 UTC --- Actually we rewrite it into SSA form where we have no way to convince the operand scanner to preserve the volatileness. I guess whoever uses automatic volatiles deserves to get stack memory.