[SelectionDAGBuilder] Remove NodeMap updates from getValueImpl. NFC (llvm#126849)

Both callers already put the result in NodeMap immediately after the
call.

Author: topperc

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -1855,7 +1855,7 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
 
       if (isa<ArrayType>(CDS->getType()))
         return DAG.getMergeValues(Ops, getCurSDLoc());
-      return NodeMap[V] = DAG.getBuildVector(VT, getCurSDLoc(), Ops);
+      return DAG.getBuildVector(VT, getCurSDLoc(), Ops);
     }
 
     if (C->getType()->isStructTy() || C->getType()->isArrayTy()) {
@@ -1898,14 +1898,13 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
 
     if (VT.isRISCVVectorTuple()) {
       assert(C->isNullValue() && "Can only zero this target type!");
-      return NodeMap[V] = DAG.getNode(
-                 ISD::BITCAST, getCurSDLoc(), VT,
-                 DAG.getNode(
-                     ISD::SPLAT_VECTOR, getCurSDLoc(),
-                     EVT::getVectorVT(*DAG.getContext(), MVT::i8,
-                                      VT.getSizeInBits().getKnownMinValue() / 8,
-                                      true),
-                     DAG.getConstant(0, getCurSDLoc(), MVT::getIntegerVT(8))));
+      return DAG.getNode(
+          ISD::BITCAST, getCurSDLoc(), VT,
+          DAG.getNode(
+              ISD::SPLAT_VECTOR, getCurSDLoc(),
+              EVT::getVectorVT(*DAG.getContext(), MVT::i8,
+                               VT.getSizeInBits().getKnownMinValue() / 8, true),
+              DAG.getConstant(0, getCurSDLoc(), MVT::getIntegerVT(8))));
     }
 
     VectorType *VecTy = cast<VectorType>(V->getType());
@@ -1918,7 +1917,7 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
       for (unsigned i = 0; i != NumElements; ++i)
         Ops.push_back(getValue(CV->getOperand(i)));
 
-      return NodeMap[V] = DAG.getBuildVector(VT, getCurSDLoc(), Ops);
+      return DAG.getBuildVector(VT, getCurSDLoc(), Ops);
     }
 
     if (isa<ConstantAggregateZero>(C)) {
@@ -1931,7 +1930,7 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
       else
         Op = DAG.getConstant(0, getCurSDLoc(), EltVT);
 
-      return NodeMap[V] = DAG.getSplat(VT, getCurSDLoc(), Op);
+      return DAG.getSplat(VT, getCurSDLoc(), Op);
     }
 
     llvm_unreachable("Unknown vector constant");