http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57949
--- Comment #7 from Bill Schmidt <wschmidt at gcc dot gnu.org> --- I rewrote the test case to use the IBM vector extensions and ran it through xlc. The generated code shows that xlc addresses the code as expected by the ABI (and contrary to what's done by gcc). So this adds weight to the argument that gcc should change its default behavior, and provide an option to generate code for the old behavior when necessary.