[PATCH] D134354: [AMDGPU][GlobalISel] Support mad/fma_mix selection

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/Utils.cpp:665-667
+    return isKnownNeverNaN(DefMI->getOperand(1).getReg(), MRI, SNaN) &&
+           isKnownNeverNaN(DefMI->getOperand(2).getReg(), MRI, SNaN) &&
+           isKnownNeverNaN(DefMI->getOperand(3).getReg(), MRI, SNaN);
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This isn't true. You can get a NaN result even if none of the inputs are NaNs, e.g. from +inf + -inf.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134354/new/

https://reviews.llvm.org/D134354