[PATCH] D151616: [Transforms][Reassociate] "Reassociate expressions" pass optimizations not always profitable

[Paul Osmialowski via Phabricator via llvm-commits]

pawosm01 added a comment.

In D151616#4381099 <https://reviews.llvm.org/D151616#4381099>, @fhahn wrote:

> There's been some work to reassoicate in LICM to enable hoisting: D148001 <https://reviews.llvm.org/D148001>. It would probably be more general to extend the logic in LICM to handle those cases, which would also trigger if the user wrote the expression like `reassociate` creates at the moment.

You were right about the user written code like that: we're doing much worse than GCC here! Yet still, addressing it in LICM and not blocking it in Reassociate will create one more place for competing optimization, and LLVM is already haunted by those.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D151616/new/

https://reviews.llvm.org/D151616