[PATCH] D67434: [InstCombine] Limit FMul constant folding for fma simplifications.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

In D67434#1666337 <https://reviews.llvm.org/D67434#1666337>, @reames wrote:

> First, please revert the previous patch until this review concludes.  We have an active miscompile in tree, and that should be addressed first.


Sure, done.

> Second, I'm not a fan of this approach.  It feels very fragile.  For example, what if someone adds a transform which exploits rounding but doesn't involve constants?  (Say, we know some bits in one of the arguments...)
> 
> I would *strongly* suggest we restructure the code such that a common utility function is used, but with two cover functions which make the appropriate guarantees about rounding for the distinct cases.

Will do, thanks.


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https://reviews.llvm.org/D67434