[PATCH] D110657: [BasicAA] Don't extend pointer size

Fri Oct 1 03:40:43 PDT 2021

fhahn added reviewers: hfinkel, efriedma.
fhahn added a comment.

> When working on non-canonical code (before first InstCombine), the GEP indices are implicitly truncated to GEP index size. The BasicAA code currently just ignores this fact completely, and pretends that this truncation doesn't happen. This is incorrect.

Agreed. For reference, this was added in D38662 <https://reviews.llvm.org/D38662>.

> I'd like to move this code towards always working on the correct size, and dropping these artificial pointer size adjustments is the first step towards that.

I tried to add a test showing the issue in 413b7ac6b535 <https://reviews.llvm.org/rG413b7ac6b535dfb4c57c2842388a2071901b9d56>, but it still gets it wrong with this patch I think. Do you know which other parts still need adjusting?

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110657/new/

https://reviews.llvm.org/D110657