tree 7aeabe9a13d6a5140150ca6d2ee6fbc79b847d59
parent f45571b39e1ce8a1105858509e6333e6832bc62d
author Roman Lebedev <lebedev.ri@gmail.com> 1615575955 +0300
committer Copybara-Service <copybara-worker@google.com> 1616071648 -0700

[SCEV] Improve modelling for (null) pointer constants

This is a continuation of D89456.

As it was suggested there, now that SCEV models `PtrToInt`,
we can try to improve SCEV's pointer handling.
In particular, i believe, i will need this in the future
to further fix `SCEVAddExpr`operation type handling.

This removes special handling of `ConstantPointerNull`
from `ScalarEvolution::createSCEV()`, and add constant folding
into `ScalarEvolution::getPtrToIntExpr()`.
This way, `null` constants stay as such in SCEV's,
but gracefully become zero integers when asked.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D98147

GitOrigin-RevId: 61f006ac655431bd44b9e089f74c73bec0c1a48c