C++ (Cpp) use_iterator::atEnd示例

示例#1

文件： BlackfinISelDAGToDAG.cpp 项目： Gcrosby5269/clamav-bytecode-compiler

// After instruction selection, insert COPY_TO_REGCLASS nodes to help in
// choosing the proper register classes.
void BlackfinDAGToDAGISel::FixRegisterClasses(SelectionDAG &DAG) {
  const BlackfinInstrInfo &TII = getInstrInfo();
  const BlackfinRegisterInfo *TRI = getRegisterInfo();
  DAG.AssignTopologicalOrder();
  HandleSDNode Dummy(DAG.getRoot());

  for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin();
       NI != DAG.allnodes_end(); ++NI) {
    if (NI->use_empty() || !NI->isMachineOpcode())
      continue;
    const TargetInstrDesc &DefTID = TII.get(NI->getMachineOpcode());
    for (SDNode::use_iterator UI = NI->use_begin(); !UI.atEnd(); ++UI) {
      if (!UI->isMachineOpcode())
        continue;

      if (UI.getUse().getResNo() >= DefTID.getNumDefs())
        continue;
      const TargetRegisterClass *DefRC =
        DefTID.OpInfo[UI.getUse().getResNo()].getRegClass(TRI);

      const TargetInstrDesc &UseTID = TII.get(UI->getMachineOpcode());
      if (UseTID.getNumDefs()+UI.getOperandNo() >= UseTID.getNumOperands())
        continue;
      const TargetRegisterClass *UseRC =
        UseTID.OpInfo[UseTID.getNumDefs()+UI.getOperandNo()].getRegClass(TRI);
      if (!DefRC || !UseRC)
        continue;
      // We cannot copy CC <-> !(CC/D)
      if ((isCC(DefRC) && !isDCC(UseRC)) || (isCC(UseRC) && !isDCC(DefRC))) {
        SDNode *Copy =
          DAG.getMachineNode(TargetOpcode::COPY_TO_REGCLASS,
                             NI->getDebugLoc(),
                             MVT::i32,
                             UI.getUse().get(),
                             DAG.getTargetConstant(BF::DRegClassID, MVT::i32));
        UpdateNodeOperand(DAG, *UI, UI.getOperandNo(), SDValue(Copy, 0));
      }
    }
  }
  DAG.setRoot(Dummy.getValue());
}