[PATCH] D98708: [LoopVectorize] relax FMF constraint for FP induction

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

> If we want to make FMF constraints consistent across the IR optimizer, we might want to add nsz too, but that's up for debate (users can't expect associative FP math and preservation of sign-of-zero at the same time?).

What's the logic here? Can we assume that reassoc implies nsz somehow? (It does sound odd/rare to have reassoc without nsz).

We may need to end up adding 0's for predicated reductions, at least in certain modes. We may want to change the identity value for fadd to a -0.0 for in-order reductions anyway though.


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  https://reviews.llvm.org/D98708/new/

https://reviews.llvm.org/D98708