https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94254
--- Comment #7 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Created attachment 48080 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48080&action=edit Proof-of-concept hack to back up the point in comment 4 This hack shows what I mean in comment 4. It "fixes" the three testcases but almost certainly isn't correct. The point is that before r10-7312 we did the mode change regardless of what rs6000_can_change_mode_class said. I don't know enough about powerpc to know what cases: if (from_size < 8 || to_size < 8) return false; is handling.