https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87361
--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > I think nonzero_bits should use SUBREG_PROMOTED_VAR_P and > SUBREG_PROMOTED_UNSIGNED_P for REGs, not LOAD_EXTEND_OP, which is > only for MEMs. I don't see how SUBREG_PROMOTED_VAR_P/SUBREG_PROMOTED_UNSIGNED_P will fit in the picture here, it's limited to RTL expansion. Ideally the REE pass should deal with that instead, but it doesn't know anything about implicit extensions.
