[PATCH] D40049: [PATCH] Global reassociation for improved CSE

[Davide Italiano via Phabricator via llvm-commits]

davide added subscribers: zhendongsu, davide.
davide added a comment.

In https://reviews.llvm.org/D40049#939097, @spatel wrote:

> My understanding of 'reassociate' isn't good enough to approve this, but I'm curious about running the main loop multiple times (ReassociateStep) because I noticed an improvement in some other code by running the pass twice.
>
> 1. Can we split that part into a preliminary patch?
> 2. Is it too expensive in compile time to run that to a fixed-point (like instcombine)?


The compile time impact here is a secondary concern.
You first need to prove this reaches a fixpoint, pencil & paper. Not necessarily looking forward to @zhendongsu reports  of this pass indefinitely looping on fuzzer generated testcases.


Repository:
  rL LLVM

https://reviews.llvm.org/D40049