https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104550
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Even in that case, filling the memory with pattern & mask instead of filling the memory with pattern + __builtin_clear_padding afterwards seems like a win. Sure, in some cases combine etc. will be able to merge those back, but in many cases it won't.
