[SelectionDAG] Remove some dead code from vector scalaring

[craig.topper]

Summary

Currently ScalarizeVecRes_SETCC checks for the result type being a vector and jumps to ScalarizeVecRes_VSETCC. But if we're scalarizing a vector result, aren't we guaranteed to be looking at a vector type?

This patch deletes the current ScalarizeVecRes_SETCC and renames ScalarizeVecRes_VSETCC to ScalarizeVecRes_SETCC.

[RKSimon]

LGTM

llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

 SDValue DAGTypeLegalizer::ScalarizeVecRes_SELECT_CC(SDNode *N) {
   SDValue LHS = GetScalarizedVector(N->getOperand(2));
   return DAG.getNode(ISD::SELECT_CC, SDLoc(N), LHS.getValueType(),
                      N->getOperand(0), N->getOperand(1),
                      LHS, GetScalarizedVector(N->getOperand(3)),
                      N->getOperand(4));
 }
 
-SDValue DAGTypeLegalizer::ScalarizeVecRes_SETCC(SDNode *N) {
-  assert(N->getValueType(0).isVector() ==
-         N->getOperand(0).getValueType().isVector() &&
-         "Scalar/Vector type mismatch");
-
-  if (N->getValueType(0).isVector()) return ScalarizeVecRes_VSETCC(N);
-
-  SDValue LHS = GetScalarizedVector(N->getOperand(0));
-  SDValue RHS = GetScalarizedVector(N->getOperand(1));
-  SDLoc DL(N);
-
-  // Turn it into a scalar SETCC.
-  return DAG.getNode(ISD::SETCC, DL, MVT::i1, LHS, RHS, N->getOperand(2));
-}
-
 SDValue DAGTypeLegalizer::ScalarizeVecRes_UNDEF(SDNode *N) {
   return DAG.getUNDEF(N->getValueType(0).getVectorElementType());
 }
 
 SDValue DAGTypeLegalizer::ScalarizeVecRes_VECTOR_SHUFFLE(SDNode *N) {
   // Figure out if the scalar is the LHS or RHS and return it.
   SDValue Arg = N->getOperand(2).getOperand(0);
   if (Arg.isUndef())
     return DAG.getUNDEF(N->getValueType(0).getVectorElementType());
   unsigned Op = !cast<ConstantSDNode>(Arg)->isNullValue();
   return GetScalarizedVector(N->getOperand(Op));
 }
 
-SDValue DAGTypeLegalizer::ScalarizeVecRes_VSETCC(SDNode *N) {
+SDValue DAGTypeLegalizer::ScalarizeVecRes_SETCC(SDNode *N) {
   assert(N->getValueType(0).isVector() &&
          N->getOperand(0).getValueType().isVector() &&
          "Operand types must be vectors");
   SDValue LHS = N->getOperand(0);
   SDValue RHS = N->getOperand(1);
   EVT OpVT = LHS.getValueType();
   EVT NVT = N->getValueType(0).getVectorElementType();
   SDLoc DL(N);