[PATCH] D53205: [FPEnv][NFCI] Convert more BinaryOperator::isFNeg(...) to m_FNeg(...)

[Cameron McInally via Phabricator via llvm-commits]

cameron.mcinally added a comment.

Ah, yeah, there is a silent regression here. From BinaryOperator::isFNeg(...):

if (!IgnoreZeroSign)

  IgnoreZeroSign = cast<Instruction>(V)->hasNoSignedZeros();

So that code is checking the NoSignedZero FastMath flag and then ignoring the sign on a zero if found.

We currently don't have that capability with the PatternMatcher functions. Those functions are fairly rigid too, so it won't be easy to add that capability. Also, it will be ugly to compensate for this shortcoming at the caller.

Any suggestions on how to proceed?


Repository:
  rL LLVM

https://reviews.llvm.org/D53205