[PATCH] D134178: [SCEV] Calculate PHI range based on its underlying values instead of just its inputs

Wed Sep 21 01:04:47 PDT 2022

nikic requested changes to this revision.
nikic added a comment.
This revision now requires changes to proceed.

Marking as changes requested for now due to known issues.

In D134178#3801903 <https://reviews.llvm.org/D134178#3801903>, @mkazantsev wrote:

> @nikic it shouldn't be a problem. If I'm reading this correctly, `PhiValues` makes computation lazily by request and supports by-value invalidation. If we have preserved SCEV => we have forgotten all values in SCEV that need to be forgotten => we have also invalidated them in PhiValues. This automatically gives what we want, no?

I'm not sure this is true, because PhiValues will also contain phis that are outside loops, and those may not get invalidated by SCEVs invalidation mechanisms, right?

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134178/new/

https://reviews.llvm.org/D134178