[PATCH] D32596: [DAGCombine] Transform (fmul X, -2.0) --> (fneg (fadd X, X)).

[Eli Friedman via Phabricator via llvm-commits]

efriedma added reviewers: RKSimon, craig.topper, arsenm.
efriedma added a comment.

Not sure if we need a target hook for this...?  Replacing one instruction with two might not always be a good idea.

Otherwise looks fine.


https://reviews.llvm.org/D32596