https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112374
--- Comment #48 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:172a72da368146e0fe34194020eb7a6636db4438 commit r14-5556-g172a72da368146e0fe34194020eb7a6636db4438 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Nov 17 15:09:44 2023 +0100 vect: Fix check_reduction_path [PR112374] As mentioned in the PR, the intent of the r14-5076 changes was that it doesn't count one of the uses on the use_stmt, but what actually got implemented is that it does this processing on any op_use_stmt, even if it is not the use_stmt statement, which means that it can increase count even on debug stmts (-fcompare-debug failures), or if there would be some other use stmt with 2+ uses it could count that as a single use. Though, because it fails whenever cnt != 1 and I believe use_stmt must be one of the uses, it would probably fail in the latter case anyway. The following patch fixes that by doing this extra processing only when op_use_stmt is use_stmt, and using the normal processing otherwise (so ignore debug stmts, and increase on any uses on the stmt). 2023-11-17 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/112374 * tree-vect-loop.cc (check_reduction_path): Perform the cond_fn_p special case only if op_use_stmt == use_stmt, use as_a rather than dyn_cast in that case. * gcc.dg/pr112374-1.c: New test. * gcc.dg/pr112374-2.c: New test. * g++.dg/opt/pr112374.C: New test.
