[llvm] expandFMINIMUMNUM_FMAXIMUMNUM: Quiet is not needed for NaN vs NaN (PR #139237)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: YunQiang Su (wzssyqa)

<details>
<summary>Changes</summary>

New LangRef doesn't requires quieting for NaN vs NaN, aka the result may be sNaN for sNaN vs NaN.
See: https://github.com/llvm/llvm-project/pull/139228

---
Full diff: https://github.com/llvm/llvm-project/pull/139237.diff


1 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp (-5) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ba34c72156228..2c63c54fc03f7 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -8683,11 +8683,6 @@ SDValue TargetLowering::expandFMINIMUMNUM_FMAXIMUMNUM(SDNode *Node,
 
   SDValue MinMax =
       DAG.getSelectCC(DL, LHS, RHS, LHS, RHS, IsMax ? ISD::SETGT : ISD::SETLT);
-  // If MinMax is NaN, let's quiet it.
-  if (!Flags.hasNoNaNs() && !DAG.isKnownNeverNaN(LHS) &&
-      !DAG.isKnownNeverNaN(RHS)) {
-    MinMax = DAG.getNode(ISD::FCANONICALIZE, DL, VT, MinMax, Flags);
-  }
 
   // Fixup signed zero behavior.
   if (Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros() ||

``````````

</details>


https://github.com/llvm/llvm-project/pull/139237