http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56597
--- Comment #5 from Kai Tietz <ktietz at gcc dot gnu.org> --- Issue here is that x64 ABI just requires that stack has 16-byte alignment. So that means within a function, using instruction requestion higher-alignment, compiler should either make sure that for those instructions variables get desired alignment, or that unaligned access is used. Otherwise I don't see here a way to resolve that, especially in scenario that code gets used by foreign compiler.
