https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97888 --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The comments in that commit look incorrect btw, // if a & b >=0 , then a >= 0. should have been // if a % b >=0 , then a >= 0. (ditto the other one).