http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56355
--- Comment #3 from Marc Glisse <glisse at gcc dot gnu.org> 2013-03-20 15:40:30 UTC --- Jeff Law mentions that it would be good to add this "squares are nonnegative" information to VRP, not just tree_binary_nonnegative_warnv_p. http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00690.html
