[X86] ExtendToType - directly initialize SmallVector with build vector operands. NFC.

Don't push_back the operands separately.

Author: RKSimon

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -32649,8 +32649,7 @@ static SDValue ExtendToType(SDValue InOp, MVT NVT, SelectionDAG &DAG,
          "Unexpected request for vector widening");
 
   SDLoc dl(InOp);
-  if (InOp.getOpcode() == ISD::CONCAT_VECTORS &&
-      InOp.getNumOperands() == 2) {
+  if (InOp.getOpcode() == ISD::CONCAT_VECTORS && InOp.getNumOperands() == 2) {
     SDValue N1 = InOp.getOperand(1);
     if ((ISD::isBuildVectorAllZeros(N1.getNode()) && FillWithZeroes) ||
         N1.isUndef()) {
@@ -32661,22 +32660,17 @@ static SDValue ExtendToType(SDValue InOp, MVT NVT, SelectionDAG &DAG,
   }
   if (ISD::isBuildVectorOfConstantSDNodes(InOp.getNode()) ||
       ISD::isBuildVectorOfConstantFPSDNodes(InOp.getNode())) {
-    SmallVector<SDValue, 16> Ops;
-    for (unsigned i = 0; i < InNumElts; ++i)
-      Ops.push_back(InOp.getOperand(i));
-
     EVT EltVT = InOp.getOperand(0).getValueType();
-
-    SDValue FillVal = FillWithZeroes ? DAG.getConstant(0, dl, EltVT) :
-      DAG.getUNDEF(EltVT);
-    for (unsigned i = 0; i < WidenNumElts - InNumElts; ++i)
-      Ops.push_back(FillVal);
+    SDValue FillVal =
+        FillWithZeroes ? DAG.getConstant(0, dl, EltVT) : DAG.getUNDEF(EltVT);
+    SmallVector<SDValue, 16> Ops(InOp->op_begin(), InOp->op_end());
+    Ops.append(WidenNumElts - InNumElts, FillVal);
     return DAG.getBuildVector(NVT, dl, Ops);
   }
-  SDValue FillVal = FillWithZeroes ? DAG.getConstant(0, dl, NVT) :
-    DAG.getUNDEF(NVT);
-  return DAG.getNode(ISD::INSERT_SUBVECTOR, dl, NVT, FillVal,
-                     InOp, DAG.getIntPtrConstant(0, dl));
+  SDValue FillVal =
+      FillWithZeroes ? DAG.getConstant(0, dl, NVT) : DAG.getUNDEF(NVT);
+  return DAG.getNode(ISD::INSERT_SUBVECTOR, dl, NVT, FillVal, InOp,
+                     DAG.getIntPtrConstant(0, dl));
 }
 
 static SDValue LowerMSCATTER(SDValue Op, const X86Subtarget &Subtarget,