On Fri, 28 Jan 2022, Jeff Law wrote: > > > On 1/24/2022 7:45 AM, Richard Biener via Gcc-patches wrote: > > There are a few cases where we know we're dealing with (poly-)integer > > constants, so remove the use of multiple_of_p in those cases to make > > the PR100499 fix less impactful. > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu. > > > > OK? > > > > Thanks, > > Richard. > > > > 2022-01-24 Richard Biener <rguent...@suse.de> > > > > PR tree-optimization/100499 > > * tree-cfg.cc (verify_gimple_assign_ternary): Use multiple_p > > on poly-ints instead of multiple_of_p. > > * tree-ssa.cc (maybe_rewrite_mem_ref_base): Likewise. > > (non_rewritable_mem_ref_base): Likewise. > > (non_rewritable_lvalue_p): Likewise. > > (execute_update_addresses_taken): Likewise. > So it's not a full fix for this class of problems, but removes some of the > cases where we could potentially overflow and give the wrong result. I'd be > happier if we had a concrete testcase for these instances you're fixing, but I > think it's a move in the right direction and I obviously trust your judgment > on whether or not to install it now or wait for gcc-13.
No, multiple_of_p has no issues with these cases since we only ever pass it [POLY_]INT_CSTs, it's just that there's no need to use multiple_of_p since we have a better tool for these cases (and thus later do not have to decide whether to use the no-wrap or wrap variant). > So your call. Both on whether or not to try and construct testcases to > trigger these instances and whether or not to install now or wait for gcc-13. I've pushed it now. Richard.
