https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91725
--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #1) > gcc10-pr91725.patch An alternative (I don't claim it is better) would be to make get_nonzero_bits conservatively return -1 on unknown input, like the comment before it seems to suggest.