http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60008
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- E.g. -fcall-saved-rdi option is ABI changing option, so you'd need to have everything (from libc, libgcov, libgcc, libstdc++, ...) built that way. Furthermore, I don't think we consider this case e.g. to disallow tail call optimization (which is generally not possible under such weird ABI).
