[PATCH] D43765: [InstSimplify] loosen FMF for sqrt(X) * sqrt(X) --> X

Matt Arsenault via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Mar 5 09:02:38 PST 2018


arsenm added a comment.

In https://reviews.llvm.org/D43765#1027289, @scanon wrote:

> IIRC `Intrinsic::sqrt` is undef for negative inputs (unlike the `sqrt` libcall), so we don't need `FMF.noNaNs` to license this transformation.


Although IMO if we're fixing all of the math in LLVM I would like to fix this. At least do something like ctlz/cttz for whether negative is undef


https://reviews.llvm.org/D43765





More information about the llvm-commits mailing list