https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116213
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Sam James from comment #3) > In this case, I suspect the warning might be legit, but bisected to > r14-3460-gabf915193fbf72 anyway. Was this with the reduced testcase or the original one? With the reduced testcase at least it could be store merging is able to merge the stores across the clobber (comment #4) before the patch while after it does not as the clobbers were removed before store merging beforehand. E.g.: NEXT_PASS (pass_fold_builtins); NEXT_PASS (pass_optimize_widening_mul); NEXT_PASS (pass_store_merging);