[Legalizer] Fix wrong operand in split vector helper

[qiucf]

Summary

It's hard to provide a test case now since vector int-to-fp isn't ready on PowerPC. But this should be easy to review. I guess it's a typo introduced in D69275.

It may cause an unknown segfault in getNode.

[uweigand]

Yes, this does look like an obvious typo. LGTM!

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

SDValue DAGTypeLegalizer::SplitVecOp_TruncateHelper(SDNode *N) {
   EVT HalfVT = EVT::getVectorVT(*DAG.getContext(), HalfElementVT,
                                 NumElements/2);
 
   SDValue HalfLo;
   SDValue HalfHi;
   SDValue Chain;
   if (N->isStrictFPOpcode()) {
     HalfLo = DAG.getNode(N->getOpcode(), DL, {HalfVT, MVT::Other},
-                         {N->getOperand(0), HalfLo});
+                         {N->getOperand(0), InLoVec});
     HalfHi = DAG.getNode(N->getOpcode(), DL, {HalfVT, MVT::Other},
-                         {N->getOperand(0), HalfHi});
+                         {N->getOperand(0), InHiVec});
     // Legalize the chain result - switch anything that used the old chain to
     // use the new one.
     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, HalfLo.getValue(1),
                         HalfHi.getValue(1));
   } else {
     HalfLo = DAG.getNode(N->getOpcode(), DL, HalfVT, InLoVec);
     HalfHi = DAG.getNode(N->getOpcode(), DL, HalfVT, InHiVec);
   }