[PATCH] D42806: [AArch64] optionally filter out denorms when using frsqrte to calculate sqrt

[Sanjay Patel via Phabricator via llvm-commits]

spatel abandoned this revision.
spatel added a comment.

In https://reviews.llvm.org/D42806#995250, @efriedma wrote:

> > Should still change the select operand to FPZero to produce the 'bic' rather than 'bsl' though?
>
> I think that changes the result for sqrt(-0.0)?  I guess we could still do it under appropriate fast-math flags.


Good point. The DAGCombiner estimate generation is only guarded by Options.UnsafeFPMath (doesn't check nodes' flags or NoSignedZerosFPMath), so it's probably wrong currently.


https://reviews.llvm.org/D42806