http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50079
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-10-28 10:52:51 UTC --- Btw, for the truly anal folks with a memcpy implementation that breaks with src == dest we can add a target hook that specifies to use memmove for block move expansion instead of memcpy (or guard the latter with a if (src != dest) on those targets). Stupid targets/implementations should not pay the penalty of a test-and-branch.