http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56392
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-19 12:25:04 UTC --- (In reply to comment #2) > (In reply to comment #1) > > You are dereferencing a pointer to uint16_t that is not sufficiently aligned > > for that type. The C standard prohibits this, resulting in undefined > > behavior. > > Thanks for your answer, but should not a warning be generated by gcc in such a > circumstance? It is, with -Wcast-align, but only on targets where unaligned accesses are not supported. That vectorization ends up turing x86_64 into such one isn't considered by the warning code ...
