[llvm] [DAG] computeKnownFPClass - add ISD::EXTRACT_VECTOR_ELT handling (PR #190307)

[Xinlong Chen via llvm-commits]

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@@ -8379,12 +8398,12 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
     if (N1.isUndef() || N2.isUndef())
       return getUNDEF(VT);
 
-    // EXTRACT_VECTOR_ELT of out-of-bounds element is an UNDEF for fixed length
+    // EXTRACT_VECTOR_ELT of out-of-bounds element is an POISON for fixed length
     // vectors. For scalable vectors we will provide appropriate support for
     // dealing with arbitrary indices.
     if (N2C && N1.getValueType().isFixedLengthVector() &&
         N2C->getAPIntValue().uge(N1.getValueType().getVectorNumElements()))
-      return getUNDEF(VT);
+      return getPOISON(VT);
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Xinlong-Chen wrote:

I have submitted it as a new PR: https://github.com/llvm/llvm-project/pull/192844;

https://github.com/llvm/llvm-project/pull/190307