[llvm] r321280 - [DAGCombiner] Remove (xor (xor x, c1), c2) -> (xor x, (xor c1, c2)) fold. NFCI.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Thu Dec 21 08:54:03 2017
New Revision: 321280

URL: http://llvm.org/viewvc/llvm-project?rev=321280&view=rev
Log:
[DAGCombiner] Remove (xor (xor x, c1), c2) -> (xor x, (xor c1, c2)) fold. NFCI.

More general cases are already handled by constant canonicalization and then the ReassociateOps call at line 5327

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=321280&r1=321279&r2=321280&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Dec 21 08:54:03 2017
@@ -5392,21 +5392,6 @@ SDValue DAGCombiner::visitXOR(SDNode *N)
     AddToWorklist(NotX.getNode());
     return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
   }
-  // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
-  if (N1C && N0.getOpcode() == ISD::XOR) {
-    if (const ConstantSDNode *N00C = getAsNonOpaqueConstant(N0.getOperand(0))) {
-      SDLoc DL(N);
-      return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(1),
-                         DAG.getConstant(N1C->getAPIntValue() ^
-                                         N00C->getAPIntValue(), DL, VT));
-    }
-    if (const ConstantSDNode *N01C = getAsNonOpaqueConstant(N0.getOperand(1))) {
-      SDLoc DL(N);
-      return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(0),
-                         DAG.getConstant(N1C->getAPIntValue() ^
-                                         N01C->getAPIntValue(), DL, VT));
-    }
-  }
 
   // fold Y = sra (X, size(X)-1); xor (add (X, Y), Y) -> (abs X)
   unsigned OpSizeInBits = VT.getScalarSizeInBits();