https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113334
--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:c75579169eba269a7c339d80b5ac0239f36a58b3 commit r14-7182-gc75579169eba269a7c339d80b5ac0239f36a58b3 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Jan 12 11:23:27 2024 +0100 lower-bitint: Fix up handling of unsigned INTEGER_CSTs operands with lots of 1s in the upper bits [PR113334] For INTEGER_CST operands, the code decides if it should emit the whole INTEGER_CST into memory, or if there are enough upper bits either all 0s or all 1s to warrant an optimization, where we use memory for lower limbs or even just an INTEGER_CST for least significant limb and fill in the rest of limbs with 0s or 1s. Unfortunately when not using bitint_min_cst_precision, the code was using tree_int_cst_sgn (op) < 0 to determine whether to fill in the upper bits with 1s or 0s. That is incorrect for TYPE_UNSIGNED INTEGER_CSTs which have higher limbs full of ones, we really want to check here whether the most significant bit is set or clear. Fixed thusly. 2024-01-12 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/113334 * gimple-lower-bitint.cc (bitint_large_huge::handle_operand): Use wi::neg_p (wi::to_wide (op)) instead of tree_int_cst_sgn (op) < 0 to determine if number should be extended by all ones rather than zero extended. * gcc.dg/torture/bitint-46.c: New test.
