[PATCH] D97244: [SimplifyCFG] Update passingValueIsAlwaysUndefined to check more attributes
Sanjay Patel via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 23 09:41:41 PST 2021
spatel added a comment.
In D97244#2581118 <https://reviews.llvm.org/D97244#2581118>, @aqjune wrote:
> @spatel Now I fully got what https://reviews.llvm.org/D96663#2578814 meant. This change is introducing assume because it introduces unreachable which finally turns into assume.
>
> But, an ongoing clang frontend patch will introduce many more noundefs, and this will anyway create assumes;
> If the assumes inserted by this patch cause problems, it is likely that the problems will happen with the noundef patch as well. I think it is about facing the problem earlier or not.
>
> If we decide to be lightweight (and not to insert assume), I'll move towards SimplifyCFG to simply swap the phi's operand with undef if nonnull without noundef is met.
Another idea - proposal to limit the creation of assumes from simplifycfg:
D97306 <https://reviews.llvm.org/D97306>
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D97244/new/
https://reviews.llvm.org/D97244
More information about the llvm-commits
mailing list