[PATCH] D31165: [SDAG] Add AllowContract to SNodeFlags

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In https://reviews.llvm.org/D31165#712746, @anemet wrote:

> In https://reviews.llvm.org/D31165#712632, @spatel wrote:
>
> > I don't know if this is addressed in one of the other patches, but we'll want to extend FMF to more than binops...or we won't be able to propagate the contract flag to FMA nodes.
>
>
> Not, it's not addressed; we can do that later if it's useful.  When is that useful?


I'm not sure, but the examples in https://reviews.llvm.org/D31164 ( x + x + x -> 3*x ) made me think we're probably missing some folds that could involve an FMA. It definitely would help when fast/reassociate/unsafe are in play as we saw in https://reviews.llvm.org/D28675.


Repository:
  rL LLVM

https://reviews.llvm.org/D31165