On June 21, 2019 4:43:10 PM GMT+02:00, Jeff Law <l...@redhat.com> wrote: >On 6/21/19 6:28 AM, Richard Biener wrote: >> On Fri, Jun 21, 2019 at 12:24 AM Jeff Law <l...@redhat.com> wrote: >>> >>> As outlined in the BZ, our alias analysis code is context >insensitive. >>> So when we copy-propagate pointers, we can can and do copy PTA >>> information from members to the representative pointer in the >copy-of >>> chain (we do this when the representative pointer has no associated >PTA >>> information). >>> >>> However, [E]VRP can set the non-nullness of a pointer using context >>> sensitive information. So we have to be more careful when copying >PTA >>> information. >>> >>> We already have similar issues with alignment information as well. >This >>> patch just extends the hack to avoid copying alignment information >in >>> some circumstances to also avoid copying the non-nullness property. >>> >>> Bootstrapped and regression tested on x86_64-linux-gnu. OK for the >trunk? >> >> I think this should be done in reset_flow_sensitive_info () as well >> and tree-ssa-copy.c should use that function instead of calling >> mark_ptr_info_alignment_unknown. >OK. Agreed that's better -- one centralized routine to reset this >stuff >if we find more over time. > >> >> I'd probably avoid the new clear_ptr_nonnull function since it might >make >> people miss the other half (alignment). >OK. Presumably you just want to twiddle the field directly? THat's >easy 'nuff.
Yes indeed. Richard. > >Jeff
