[Bug middle-end/59990] [4.7/4.8/4.9 regression] incorrect memcpy optimization

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59990

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 31991
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31991&action=edit
patch

Must resist turning this fn upside down ...

Anyway, untested patch attached.  We can surely do better selecting a
type, but IIRC most targets have an integer mode that covers all other
modes (even vector modes).