C++ ListInit::begin方法代码示例

static const std::vector<StringRef>
getValueAsListOfStrings(Record &R, StringRef FieldName) {
  ListInit *List = R.getValueAsListInit(FieldName);
  assert (List && "Got a null ListInit");

  std::vector<StringRef> Strings;
  Strings.reserve(List->getSize());

  for (ListInit::iterator i = List->begin(), e = List->end(); i != e; ++i) {
    assert(*i && "Got a null element in a ListInit");
    if (StringInit *S = dynamic_cast<StringInit *>(*i))
      Strings.push_back(S->getValue());
    else if (CodeInit *C = dynamic_cast<CodeInit *>(*i))
      Strings.push_back(C->getValue());
    else
      assert(false && "Got a non-string, non-code element in a ListInit");
  }

  return Strings;
}

CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank, Record *R)
  : TheDef(R), Name(R->getName()), EnumValue(-1) {
  // Rename anonymous register classes.
  if (R->getName().size() > 9 && R->getName()[9] == '.') {
    static unsigned AnonCounter = 0;
    R->setName("AnonRegClass_"+utostr(AnonCounter++));
  }

  std::vector<Record*> TypeList = R->getValueAsListOfDefs("RegTypes");
  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
    Record *Type = TypeList[i];
    if (!Type->isSubClassOf("ValueType"))
      throw "RegTypes list member '" + Type->getName() +
        "' does not derive from the ValueType class!";
    VTs.push_back(getValueType(Type));
  }
  assert(!VTs.empty() && "RegisterClass must contain at least one ValueType!");

  // Allocation order 0 is the full set. AltOrders provides others.
  const SetTheory::RecVec *Elements = RegBank.getSets().expand(R);
  ListInit *AltOrders = R->getValueAsListInit("AltOrders");
  Orders.resize(1 + AltOrders->size());

  // Default allocation order always contains all registers.
  for (unsigned i = 0, e = Elements->size(); i != e; ++i) {
    Orders[0].push_back((*Elements)[i]);
    Members.insert(RegBank.getReg((*Elements)[i]));
  }

  // Alternative allocation orders may be subsets.
  SetTheory::RecSet Order;
  for (unsigned i = 0, e = AltOrders->size(); i != e; ++i) {
    RegBank.getSets().evaluate(AltOrders->getElement(i), Order);
    Orders[1 + i].append(Order.begin(), Order.end());
    // Verify that all altorder members are regclass members.
    while (!Order.empty()) {
      CodeGenRegister *Reg = RegBank.getReg(Order.back());
      Order.pop_back();
      if (!contains(Reg))
        throw TGError(R->getLoc(), " AltOrder register " + Reg->getName() +
                      " is not a class member");
    }
  }

  // SubRegClasses is a list<dag> containing (RC, subregindex, ...) dags.
  ListInit *SRC = R->getValueAsListInit("SubRegClasses");
  for (ListInit::const_iterator i = SRC->begin(), e = SRC->end(); i != e; ++i) {
    DagInit *DAG = dynamic_cast<DagInit*>(*i);
    if (!DAG) throw "SubRegClasses must contain DAGs";
    DefInit *DAGOp = dynamic_cast<DefInit*>(DAG->getOperator());
    Record *RCRec;
    if (!DAGOp || !(RCRec = DAGOp->getDef())->isSubClassOf("RegisterClass"))
      throw "Operator '" + DAG->getOperator()->getAsString() +
        "' in SubRegClasses is not a RegisterClass";
    // Iterate over args, all SubRegIndex instances.
    for (DagInit::const_arg_iterator ai = DAG->arg_begin(), ae = DAG->arg_end();
         ai != ae; ++ai) {
      DefInit *Idx = dynamic_cast<DefInit*>(*ai);
      Record *IdxRec;
      if (!Idx || !(IdxRec = Idx->getDef())->isSubClassOf("SubRegIndex"))
        throw "Argument '" + (*ai)->getAsString() +
          "' in SubRegClasses is not a SubRegIndex";
      if (!SubRegClasses.insert(std::make_pair(IdxRec, RCRec)).second)
        throw "SubRegIndex '" + IdxRec->getName() + "' mentioned twice";
    }
  }

  // Allow targets to override the size in bits of the RegisterClass.
  unsigned Size = R->getValueAsInt("Size");

  Namespace = R->getValueAsString("Namespace");
  SpillSize = Size ? Size : EVT(VTs[0]).getSizeInBits();
  SpillAlignment = R->getValueAsInt("Alignment");
  CopyCost = R->getValueAsInt("CopyCost");
  Allocatable = R->getValueAsBit("isAllocatable");
  AltOrderSelect = R->getValueAsCode("AltOrderSelect");
}