[PATCH] D104383: [InstSimplify] propagate poison through FP ops

[Sanjay Patel via Phabricator via llvm-commits]

spatel created this revision.
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We already have this fold:

  fadd float poison, 1.0 --> poison

...via ConstantFolding, so this makes the behavior consistent if the other operand(s) are non-constant.

The fold for undef was added before poison existed as a value/type in IR.

This came up in D102673 <https://reviews.llvm.org/D102673> / D103169 <https://reviews.llvm.org/D103169> because we're trying to sort out the more complicated handling for constrained math ops. 
We should have the handling for the regular instructions done first, so we can build on that (or diverge as needed).


https://reviews.llvm.org/D104383

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp
  llvm/test/Transforms/InstSimplify/call.ll
  llvm/test/Transforms/InstSimplify/fp-undef-poison.ll

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