diff options
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index cb80e25038..9203c81f55 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -696,6 +696,14 @@ SDOperand DAGCombiner::visitADD(SDNode *N) { return DAG.getNode(ISD::ADD, VT, N0.getOperand(0), DAG.getConstant(N1C->getValue()+N01C->getValue(), VT)); } + + // fold ((c1-A)+c2) -> (c1+c2)-A + if (N1C && N0.getOpcode() == ISD::SUB) + if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0))) + return DAG.getNode(ISD::SUB, VT, + DAG.getConstant(N1C->getValue()+N0C->getValue(), VT), + N0.getOperand(1)); + // fold ((0-A) + B) -> B-A if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) && cast<ConstantSDNode>(N0.getOperand(0))->isNullValue()) |