Make use of commutable matching in foldBitOrderCrossLogicOp

Author: RKSimon

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -10553,29 +10553,20 @@ static SDValue foldBitOrderCrossLogicOp(SDNode *N, SelectionDAG &DAG) {
   SDValue N0 = N->getOperand(0);
   EVT VT = N->getValueType(0);
   SDLoc DL(N);
+  SDValue X, Y;
 
-  SDValue OldLHS, OldRHS;
-  if (sd_match(N0,
-               m_OneUse(m_BitwiseLogic(m_Value(OldLHS), m_Value(OldRHS))))) {
-    // If both operands are bswap/bitreverse, ignore the multiuse
-    // Otherwise need to ensure logic_op and bswap/bitreverse(x) have one use.
-    if (OldLHS.getOpcode() == Opcode && OldRHS.getOpcode() == Opcode) {
-      return DAG.getNode(N0.getOpcode(), DL, VT, OldLHS.getOperand(0),
-                         OldRHS.getOperand(0));
-    }
+  // If both operands are bswap/bitreverse, ignore the multiuse
+  if (sd_match(N0, m_OneUse(m_BitwiseLogic(m_UnaryOp(Opcode, m_Value(X)),
+                                           m_UnaryOp(Opcode, m_Value(Y))))))
+    return DAG.getNode(N0.getOpcode(), DL, VT, X, Y);
 
-    if (OldLHS.getOpcode() == Opcode && OldLHS.hasOneUse()) {
-      SDValue NewBitReorder = DAG.getNode(Opcode, DL, VT, OldRHS);
-      return DAG.getNode(N0.getOpcode(), DL, VT, OldLHS.getOperand(0),
-                         NewBitReorder);
-    }
-
-    if (OldRHS.getOpcode() == Opcode && OldRHS.hasOneUse()) {
-      SDValue NewBitReorder = DAG.getNode(Opcode, DL, VT, OldLHS);
-      return DAG.getNode(N0.getOpcode(), DL, VT, NewBitReorder,
-                         OldRHS.getOperand(0));
-    }
+  // Otherwise need to ensure logic_op and bswap/bitreverse(x) have one use.
+  if (sd_match(N0, m_OneUse(m_BitwiseLogic(
+                       m_OneUse(m_UnaryOp(Opcode, m_Value(X))), m_Value(Y))))) {
+    SDValue NewBitReorder = DAG.getNode(Opcode, DL, VT, Y);
+    return DAG.getNode(N0.getOpcode(), DL, VT, X, NewBitReorder);
   }
+
   return SDValue();
 }