diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index f33ecd7223..7cf89144c3 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -892,6 +892,12 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, return getNode(ISD::SUB, VT, N1, N2.getOperand(0)); if (N1.getOpcode() == ISD::FNEG) // ((-A)+B) -> B-A return getNode(ISD::SUB, VT, N2, N1.getOperand(0)); + if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) && + cast<ConstantSDNode>(N1.getOperand(0))->getValue() == 0) + return getNode(ISD::SUB, VT, N2, N1.getOperand(1)); // (0-A)+B -> B-A + if (N2.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N2.getOperand(0)) && + cast<ConstantSDNode>(N2.getOperand(0))->getValue() == 0) + return getNode(ISD::SUB, VT, N1, N2.getOperand(1)); // A+(0-B) -> A-B break; case ISD::SUB: if (N1.getOpcode() == ISD::ADD) { |