[PATCH] D30446: [IndVars] Do not branch on poison

[Andrew Trick via Phabricator via llvm-commits]

atrick added a comment.

Materializing a new IV isn't a good canonicalization. It may block other loop transformations and there's no guarantee that LSR will undo it. General rule: never pessimize your loop and expect LSR to rewrite it. LSR only works well on a small subset of loops and essentially gives up in a lot of cases. I agree the complexity smells bad. I don't have a better suggestion at the moment.


https://reviews.llvm.org/D30446