[PATCH] D113291: [AggressiveInstCombine] Lower Table Based CTTZ

Thu Sep 8 09:28:24 PDT 2022

spatel added a comment.

In D113291#3777356 <https://reviews.llvm.org/D113291#3777356>, @djtodoro wrote:

> Actually, the issue was that your patch D129167 <https://reviews.llvm.org/D129167> introduced `eraseFromParent` and the `tryToRecognizeTableBasedCttz` would try to use the instruction (`dyn_cast`) after free. I just moved the `tryToRecognizeTableBasedCttz` above `foldSqrt`. I guess it does not need any additional test case.

Ah, I see. Please put a comment on that call then - foldSqrt (or any other erasing transform) needs to be accounted for (last in the loop for now), or we might hit that bug. And yes, looks like we don't need another test since the existing regression test was flagged by the asan bot.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113291/new/

https://reviews.llvm.org/D113291