Recently zero_one_valued_p was changed to handle integer_zerop
case specially, because tree_nonzero_bits (@0) == 1 only returns
true for non-constant values with range [0, 1] or constant 1,
constant 0 has tree_nonzero_bits (integer_zero_node) == 0.
The following patch reverts that change and instead checks
that tree_nonzero_bits is <= 1U.
2023-06-07 Jakub Jelinek <jakub@redhat.com>
* match.pd (zero_one_valued_p): Don't handle integer_zerop specially,
instead compare tree_nonzero_bits <= 1U rather than just == 1.
git://gcc.gnu.org / gcc.git / commit