https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65443
--- Comment #3 from vries at gcc dot gnu.org --- (In reply to vries from comment #2) > The problem with this transformation is that '_20 + 1' might overflow, > that's what the comment 'This may need some additional preconditioning in > case NIT = ~0' refers to. AFAIU, we might also move 'ivtmp_6 = ivtmp_y + 1' to the end of bb4. That way it's not triggered at loop entry, as before the transformation, eliminating the need for '_20 + 1'.
