https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111048
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Prathamesh Kulkarni <prathamesh3...@gcc.gnu.org>: https://gcc.gnu.org/g:649388462e9a3c2de0b90ce525de8044704cc521 commit r14-3355-g649388462e9a3c2de0b90ce525de8044704cc521 Author: Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> Date: Mon Aug 21 15:25:08 2023 +0530 PR111048: Set arg_npatterns correctly. In valid_mask_for_fold_vec_perm_cst we set arg_npatterns always to VECTOR_CST_NPATTERNS (arg0) because of (q1 & 0) == 0: /* Ensure that the stepped sequence always selects from the same input pattern. */ unsigned arg_npatterns = ((q1 & 0) == 0) ? VECTOR_CST_NPATTERNS (arg0) : VECTOR_CST_NPATTERNS (arg1); resulting in wrong code-gen issues. The patch fixes this by changing the condition to (q1 & 1) == 0. gcc/ChangeLog: PR tree-optimization/111048 * fold-const.cc (valid_mask_for_fold_vec_perm_cst_p): Set arg_npatterns correctly. (fold_vec_perm_cst): Remove workaround and again call valid_mask_fold_vec_perm_cst_p for both VLS and VLA vectors. (test_fold_vec_perm_cst::test_nunits_min_4): Add test-case.
