C++ Pattern::getRecord方法代码示例

void InstrSelectorEmitter::run(std::ostream &OS) {
  // Type-check all of the node types to ensure we "understand" them.
  ReadNodeTypes();
  
  // Read in all of the nonterminals, instructions, and expanders...
  ReadNonterminals();
  ReadInstructionPatterns();
  ReadExpanderPatterns();

  // Instantiate any unresolved nonterminals with information from the context
  // that they are used in.
  InstantiateNonterminals();

  // Clear InstantiatedNTs, we don't need it anymore...
  InstantiatedNTs.clear();

  DEBUG(std::cerr << "Patterns acquired:\n");
  for (std::map<Record*, Pattern*>::iterator I = Patterns.begin(),
         E = Patterns.end(); I != E; ++I)
    if (I->second->isResolved())
      DEBUG(std::cerr << "  " << *I->second << "\n");

  CalculateComputableValues();
  
  OS << "#include \"llvm/CodeGen/MachineInstrBuilder.h\"\n";

  EmitSourceFileHeader("Instruction Selector for the " + Target.getName() +
                       " target", OS);

  // Output the slot number enums...
  OS << "\nenum { // Slot numbers...\n"
     << "  LastBuiltinSlot = ISD::NumBuiltinSlots-1, // Start numbering here\n";
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I)
    OS << "  " << I->first << "_Slot,\n";
  OS << "  NumSlots\n};\n\n// Reduction value typedefs...\n";

  // Output the reduction value typedefs...
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I) {

    OS << "typedef ReducedValue<unsigned, " << I->first
       << "_Slot> ReducedValue_" << I->first << ";\n";
  }

  // Output the pattern enums...
  OS << "\n\n"
     << "enum { // Patterns...\n"
     << "  NotComputed = 0,\n"
     << "  NoMatchPattern, \n";
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I) {
    OS << "  // " << I->first << " patterns...\n";
    for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
           E = I->second.end(); J != E; ++J)
      for (unsigned i = 0, e = J->second.size(); i != e; ++i)
        OS << "  " << J->second[i]->getRecord()->getName() << "_Pattern,\n";
  }
  OS << "};\n\n";

  //===--------------------------------------------------------------------===//
  // Emit the class definition...
  //
  OS << "namespace {\n"
     << "  class " << Target.getName() << "ISel {\n"
     << "    SelectionDAG &DAG;\n"
     << "  public:\n"
     << "    " << Target.getName () << "ISel(SelectionDAG &D) : DAG(D) {}\n"
     << "    void generateCode();\n"
     << "  private:\n"
     << "    unsigned makeAnotherReg(const TargetRegisterClass *RC) {\n"
     << "      return DAG.getMachineFunction().getSSARegMap()->createVirt"
                                       "ualRegister(RC);\n"
     << "    }\n\n"
     << "    // DAG matching methods for classes... all of these methods"
                                       " return the cost\n"
     << "    // of producing a value of the specified class and type, which"
                                       " also gets\n"
     << "    // added to the DAG node.\n";

  // Output all of the matching prototypes for slots...
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I)
    OS << "    unsigned Match_" << I->first << "(SelectionDAGNode *N);\n";
  OS << "\n    // DAG matching methods for DAG nodes...\n";

  // Output all of the matching prototypes for slot/node pairs
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I)
    for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
           E = I->second.end(); J != E; ++J)
      OS << "    unsigned Match_" << I->first << "_" << getNodeName(J->first)
         << "(SelectionDAGNode *N);\n";

  // Output all of the dag reduction methods prototypes...
  OS << "\n    // DAG reduction methods...\n";
  for (PatternOrganizer::iterator I = ComputableValues.begin(),
         E = ComputableValues.end(); I != E; ++I)
    OS << "    ReducedValue_" << I->first << " *Reduce_" << I->first
       << "(SelectionDAGNode *N,\n" << std::string(27+2*I->first.size(), ' ')
//.........这里部分代码省略.........

// EmitMatchCosters - Given a list of patterns, which all have the same root
// pattern operator, emit an efficient decision tree to decide which one to
// pick.  This is structured this way to avoid reevaluations of non-obvious
// subexpressions.
void InstrSelectorEmitter::EmitMatchCosters(std::ostream &OS,
           const std::vector<std::pair<Pattern*, TreePatternNode*> > &Patterns,
                                            const std::string &VarPrefix,
                                            unsigned IndentAmt) {
  assert(!Patterns.empty() && "No patterns to emit matchers for!");
  std::string Indent(IndentAmt, ' ');
  
  // Load all of the operands of the root node into scalars for fast access
  const NodeType &ONT = getNodeType(Patterns[0].second->getOperator());
  for (unsigned i = 0, e = ONT.ArgTypes.size(); i != e; ++i)
    OS << Indent << "SelectionDAGNode *" << VarPrefix << "_Op" << i
       << " = N->getUse(" << i << ");\n";

  // Compute the costs of computing the various nonterminals/registers, which
  // are directly used at this level.
  OS << "\n" << Indent << "// Operand matching costs...\n";
  std::set<std::string> ComputedValues;   // Avoid duplicate computations...
  for (unsigned i = 0, e = Patterns.size(); i != e; ++i) {
    TreePatternNode *NParent = Patterns[i].second;
    for (unsigned c = 0, e = NParent->getNumChildren(); c != e; ++c) {
      TreePatternNode *N = NParent->getChild(c);
      if (N->isLeaf()) {
        Record *VR = N->getValueRecord();
        const std::string &LeafName = VR->getName();
        std::string OpName  = VarPrefix + "_Op" + utostr(c);
        std::string ValName = OpName + "_" + LeafName + "_Cost";
        if (!ComputedValues.count(ValName)) {
          OS << Indent << "unsigned " << ValName << " = Match_"
             << Pattern::getSlotName(VR) << "(" << OpName << ");\n";
          ComputedValues.insert(ValName);
        }
      }
    }
  }
  OS << "\n";


  std::string LocCostName = VarPrefix + "_Cost";
  OS << Indent << "unsigned " << LocCostName << "Min = ~0U >> 1;\n"
     << Indent << "unsigned " << VarPrefix << "_PatternMin = NoMatchPattern;\n";
  
#if 0
  // Separate out all of the patterns into groups based on what their top-level
  // signature looks like...
  std::vector<std::pair<Pattern*, TreePatternNode*> > PatternsLeft(Patterns);
  while (!PatternsLeft.empty()) {
    // Process all of the patterns that have the same signature as the last
    // element...
    std::vector<std::pair<Pattern*, TreePatternNode*> > Group;
    MoveIdenticalPatterns(PatternsLeft.back().second, PatternsLeft, Group);
    assert(!Group.empty() && "Didn't at least pick the source pattern?");

#if 0
    OS << "PROCESSING GROUP:\n";
    for (unsigned i = 0, e = Group.size(); i != e; ++i)
      OS << "  " << *Group[i].first << "\n";
    OS << "\n\n";
#endif

    OS << Indent << "{ // ";

    if (Group.size() != 1) {
      OS << Group.size() << " size group...\n";
      OS << Indent << "  unsigned " << VarPrefix << "_Pattern = NoMatch;\n";
    } else {
      OS << *Group[0].first << "\n";
      OS << Indent << "  unsigned " << VarPrefix << "_Pattern = "
         << Group[0].first->getRecord()->getName() << "_Pattern;\n";
    }

    OS << Indent << "  unsigned " << LocCostName << " = ";
    if (Group.size() == 1)
      OS << "1;\n";    // Add inst cost if at individual rec
    else
      OS << "0;\n";

    // Loop over all of the operands, adding in their costs...
    TreePatternNode *N = Group[0].second;
    const std::vector<TreePatternNode*> &Children = N->getChildren();

    // If necessary, emit conditionals to check for the appropriate tree
    // structure here...
    for (unsigned i = 0, e = Children.size(); i != e; ++i) {
      TreePatternNode *C = Children[i];
      if (C->isLeaf()) {
        // We already calculated the cost for this leaf, add it in now...
        OS << Indent << "  " << LocCostName << " += "
           << VarPrefix << "_Op" << utostr(i) << "_"
           << C->getValueRecord()->getName() << "_Cost;\n";
      } else {
        // If it's not a leaf, we have to check to make sure that the current
        // node has the appropriate structure, then recurse into it...
        OS << Indent << "  if (" << VarPrefix << "_Op" << i
           << "->getNodeType() == ISD::" << getNodeName(C->getOperator())
           << ") {\n";
        std::vector<std::pair<Pattern*, TreePatternNode*> > SubPatterns;
//.........这里部分代码省略.........