http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55152
--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> 2012-10-31 21:14:12 UTC --- Ignoring signed zeros, sure, that's also required to generate a MAX_EXPR in the first place. NaNs, I don't know, it sounds to me like they have an effect on generating a MAX_EXPR, but turning the MAX into an ABS should be safe. (sometimes I wish for a __builtin_max, and -fno-nans)