[PATCH] D50913: [FPEnv] Don't need copysign/fabs/fneg constrained intrinsics

[Cameron McInally via Phabricator via llvm-commits]

cameron.mcinally added a comment.

I'm looking into the FNEG handling and found one bad xform in llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:

// Expand Y = FNEG(X) ->  Y = SUB -0.0, X

That's not necessarily a show-stopper though. We could change this code to do a bitwise operation instead. That may even be faster than a FSUB, depending on the target of course.


Repository:
  rL LLVM

https://reviews.llvm.org/D50913