https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89195
--- Comment #4 from Wilco <wilco at gcc dot gnu.org> --- (In reply to Segher Boessenkool from comment #3) > (In reply to Wilco from comment #1) > > len is unsigned HOST_WIDE_INT, so bits_to_bytes_round_down does an unsigned > > division... > > That shouldn't make a difference though, both dividend and divisor should be > non-negative. Are they? Well I guess not... So pos points outside of the > register here?! pos is a frame offset so always negative. And yes this code is then creating an access outside the original object (starting at -1 or +1 depending on endianness). > Was it correct before that? At least it was symmetric so it *seemed* > correct.. It was broken in the same way. If I cast just len to HOST_WIDE_INT it works fine.
