https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103417
--- Comment #6 from CVS 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:94912212d3d1be0b1c490e9b5f45165ef5f30d8a commit r12-5513-g94912212d3d1be0b1c490e9b5f45165ef5f30d8a Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Nov 25 10:47:24 2021 +0100 match.pd: Fix up the recent bitmask_inv_cst_vector_p simplification [PR103417] The following testcase is miscompiled since the r12-5489-g0888d6bbe97e10 changes. The simplification triggers on (x & 4294967040U) >= 0U and turns it into: x <= 255U which is incorrect, it should fold to 1 because unsigned >= 0U is always true and normally the /* Non-equality compare simplifications from fold_binary */ (if (wi::to_wide (cst) == min) (if (cmp == GE_EXPR) { constant_boolean_node (true, type); }) simplification folds that, but this simplification was done earlier. The simplification correctly doesn't include lt which has the same reason why it shouldn't be handled, we'll fold it to 0 elsewhere. But, IMNSHO while it isn't incorrect to handle le and gt there, it is unnecessary. Because (x & cst) <= 0U and (x & cst) > 0U should never appear, again in /* Non-equality compare simplifications from fold_binary */ we have a simplification for it: (if (cmp == LE_EXPR) (eq @2 @1)) (if (cmp == GT_EXPR) (ne @2 @1)))) This is done for (cmp (convert?@2 @0) uniform_integer_cst_p@1) and so should be done for both integers and vectors. As the bitmask_inv_cst_vector_p simplification only handles eq and ne for signed types, I think it can be simplified to just following patch. 2021-11-25 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/103417 * match.pd ((X & Y) CMP 0): Only handle eq and ne. Commonalize common tests. * gcc.c-torture/execute/pr103417.c: New test.
