https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108237
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:4c8e17a6a578b9eb15cd210651b6ea273022db39 commit r12-9136-g4c8e17a6a578b9eb15cd210651b6ea273022db39 Author: Jakub Jelinek <ja...@redhat.com> Date: Wed Jan 4 10:54:38 2023 +0100 generic-match-head: Don't assume GENERIC folding is done only early [PR108237] We ICE on the following testcase, because a valid V2DImode != comparison is folded into an unsupported V2DImode > comparison. The match.pd pattern which does this looks like: /* Transform comparisons of the form (X & Y) CMP 0 to X CMP2 Z where ~Y + 1 == pow2 and Z = ~Y. */ (for cst (VECTOR_CST INTEGER_CST) (for cmp (eq ne) icmp (le gt) (simplify (cmp (bit_and:c@2 @0 cst@1) integer_zerop) (with { tree csts = bitmask_inv_cst_vector_p (@1); } (if (csts && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2))) (with { auto optab = VECTOR_TYPE_P (TREE_TYPE (@1)) ? optab_vector : optab_default; tree utype = unsigned_type_for (TREE_TYPE (@1)); } (if (target_supports_op_p (utype, icmp, optab) || (optimize_vectors_before_lowering_p () && (!target_supports_op_p (type, cmp, optab) || !target_supports_op_p (type, BIT_AND_EXPR, optab)))) (if (TYPE_UNSIGNED (TREE_TYPE (@1))) (icmp @0 { csts; }) (icmp (view_convert:utype @0) { csts; }))))))))) and that optimize_vectors_before_lowering_p () guarded stuff there already deals with this problem, not trying to fold a supported comparison into a non-supported one. The reason it doesn't work in this case is that it isn't GIMPLE folding which does this, but GENERIC folding done during forwprop4 - forward_propagate_into_comparison -> forward_propagate_into_comparison_1 -> combine_cond_expr_cond -> fold_binary_loc -> generic_simplify and we simply assumed that GENERIC folding happens only before gimplification. The following patch fixes that by checking cfun properties instead of always returning true in those cases. 2023-01-04 Jakub Jelinek <ja...@redhat.com> PR middle-end/108237 * generic-match-head.cc: Include tree-pass.h. (canonicalize_math_p, optimize_vectors_before_lowering_p): Define to false if cfun and cfun->curr_properties has PROP_gimple_opt_math resp. PROP_gimple_lvec property set. * gcc.c-torture/compile/pr108237.c: New test. (cherry picked from commit 345dffd0d4ebff7e705dfff1a8a72017a167120a)
