[PATCH] D28675: [DAGCombine] require UnsafeFPMath for re-association of addition

Matt Arsenault via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Jan 16 16:06:21 PST 2017


arsenm added a comment.

In https://reviews.llvm.org/D28675#645325, @hfinkel wrote:

> In https://reviews.llvm.org/D28675#645313, @mehdi_amini wrote:
>
> > What about individual FMF?
>
>
> I agree; these transforms rely on the associativity of addition. As Mehdi says, you should check the FMFs on the individual instructions.


This would be nice, but it seems right now you can only use FMF flags with a fixed set of binary nodes, so no FMA/FMAD


https://reviews.llvm.org/D28675





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