[X86] Add generic splitVectorOp helper. NFC

Update splitVectorIntUnary/splitVectorIntBinary to use this internally, after some operand type sanity checks.

Avoid code duplication and makes it easier to split other vector instruction forms in the future.

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -6293,57 +6293,55 @@ static std::pair<SDValue, SDValue> splitVector(SDValue Op, SelectionDAG &DAG,
   return std::make_pair(Lo, Hi);
 }
 
-// Split an unary integer op into 2 half sized ops.
-static SDValue splitVectorIntUnary(SDValue Op, SelectionDAG &DAG) {
+/// Break an operation into 2 half sized ops and then concatenate the results.
+static SDValue splitVectorOp(SDValue Op, SelectionDAG &DAG) {
+  unsigned NumOps = Op.getNumOperands();
   EVT VT = Op.getValueType();
+  SDLoc dl(Op);
+
+  // Extract the LHS Lo/Hi vectors
+  SmallVector<SDValue> LoOps(NumOps, SDValue());
+  SmallVector<SDValue> HiOps(NumOps, SDValue());
+  for (unsigned I = 0; I != NumOps; ++I) {
+    SDValue SrcOp = Op.getOperand(I);
+    if (!SrcOp.getValueType().isVector()) {
+      LoOps[I] = HiOps[I] = SrcOp;
+      continue;
+    }
+    std::tie(LoOps[I], HiOps[I]) = splitVector(SrcOp, DAG, dl);
+  }
 
+  EVT LoVT, HiVT;
+  std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
+  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
+                     DAG.getNode(Op.getOpcode(), dl, LoVT, LoOps),
+                     DAG.getNode(Op.getOpcode(), dl, HiVT, HiOps));
+}
+
+/// Break an unary integer operation into 2 half sized ops and then
+/// concatenate the result back.
+static SDValue splitVectorIntUnary(SDValue Op, SelectionDAG &DAG) {
   // Make sure we only try to split 256/512-bit types to avoid creating
   // narrow vectors.
+  EVT VT = Op.getValueType();
   assert((Op.getOperand(0).getValueType().is256BitVector() ||
           Op.getOperand(0).getValueType().is512BitVector()) &&
          (VT.is256BitVector() || VT.is512BitVector()) && "Unsupported VT!");
   assert(Op.getOperand(0).getValueType().getVectorNumElements() ==
              VT.getVectorNumElements() &&
          "Unexpected VTs!");
-
-  SDLoc dl(Op);
-
-  // Extract the Lo/Hi vectors
-  SDValue Lo, Hi;
-  std::tie(Lo, Hi) = splitVector(Op.getOperand(0), DAG, dl);
-
-  EVT LoVT, HiVT;
-  std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
-  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
-                     DAG.getNode(Op.getOpcode(), dl, LoVT, Lo),
-                     DAG.getNode(Op.getOpcode(), dl, HiVT, Hi));
+  return splitVectorOp(Op, DAG);
 }
 
 /// Break a binary integer operation into 2 half sized ops and then
 /// concatenate the result back.
 static SDValue splitVectorIntBinary(SDValue Op, SelectionDAG &DAG) {
-  EVT VT = Op.getValueType();
-
   // Sanity check that all the types match.
+  EVT VT = Op.getValueType();
   assert(Op.getOperand(0).getValueType() == VT &&
          Op.getOperand(1).getValueType() == VT && "Unexpected VTs!");
   assert((VT.is256BitVector() || VT.is512BitVector()) && "Unsupported VT!");
-
-  SDLoc dl(Op);
-
-  // Extract the LHS Lo/Hi vectors
-  SDValue LHS1, LHS2;
-  std::tie(LHS1, LHS2) = splitVector(Op.getOperand(0), DAG, dl);
-
-  // Extract the RHS Lo/Hi vectors
-  SDValue RHS1, RHS2;
-  std::tie(RHS1, RHS2) = splitVector(Op.getOperand(1), DAG, dl);
-
-  EVT LoVT, HiVT;
-  std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
-  return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
-                     DAG.getNode(Op.getOpcode(), dl, LoVT, LHS1, RHS1),
-                     DAG.getNode(Op.getOpcode(), dl, HiVT, LHS2, RHS2));
+  return splitVectorOp(Op, DAG);
 }
 
 // Helper for splitting operands of an operation to legal target size and