https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118954
--- Comment #13 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:ee30e2586a3142e63daaf301a561984f1d22d38d commit r15-7665-gee30e2586a3142e63daaf301a561984f1d22d38d Author: Richard Biener <rguent...@suse.de> Date: Fri Feb 21 09:58:04 2025 +0100 tree-optimization/118954 - avoid UB on ref created by predcom When predicitive commoning moves an invariant ref it makes sure to not build a MEM_REF with a base that is negatively offsetted from an object. But in trying to preserve some transforms it does not consider association of a constant offset with the address computation in DR_BASE_ADDRESS leading to exactly this problem again. This is arguably a problem in data-ref analysis producing such an out-of-bound DR_BASE_ADDRESS, but this looks quite involved to fix, so the following avoids the association in one more case. This fixes the testcase while preserving the desired transform in gcc.dg/tree-ssa/predcom-1.c. PR tree-optimization/118954 * tree-predcom.cc (ref_at_iteration): Make sure to not associate the constant offset with DR_BASE_ADDRESS when that is an offsetted pointer. * gcc.dg/torture/pr118954.c: New testcase.
