Interval.h

//===- llvm/Analysis/Interval.h - Interval Class Declaration ----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the Interval class, which
// represents a set of CFG nodes and is a portion of an interval partition.
//
// Intervals have some interesting and useful properties, including the
// following:
//    1. The header node of an interval dominates all of the elements of the
//       interval
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_INTERVAL_H
#define LLVM_INTERVAL_H

#include "llvm/ADT/GraphTraits.h"
#include <vector>

namespace llvm {

class BasicBlock;
class raw_ostream;

//===----------------------------------------------------------------------===//
//
class Interval {
  BasicBlock *HeaderNode;
public:
  typedef std::vector<BasicBlock*>::iterator succ_iterator;
  typedef std::vector<BasicBlock*>::iterator pred_iterator;
  typedef std::vector<BasicBlock*>::iterator node_iterator;

  inline Interval(BasicBlock *Header) : HeaderNode(Header) {
    Nodes.push_back(Header);
  }

  inline Interval(const Interval &I) // copy ctor
    : HeaderNode(I.HeaderNode), Nodes(I.Nodes), Successors(I.Successors) {}

  inline BasicBlock *getHeaderNode() const { return HeaderNode; }

  std::vector<BasicBlock*> Nodes;

  std::vector<BasicBlock*> Successors;

  std::vector<BasicBlock*> Predecessors;

  inline bool contains(BasicBlock *BB) const {
    for (unsigned i = 0; i < Nodes.size(); ++i)
      if (Nodes[i] == BB) return true;
    return false;
    // I don't want the dependency on <algorithm>
    //return find(Nodes.begin(), Nodes.end(), BB) != Nodes.end();
  }

  inline bool isSuccessor(BasicBlock *BB) const {
    for (unsigned i = 0; i < Successors.size(); ++i)
      if (Successors[i] == BB) return true;
    return false;
    // I don't want the dependency on <algorithm>
    //return find(Successors.begin(), Successors.end(), BB) != Successors.end();
  }

  inline bool operator==(const Interval &I) const {
    return HeaderNode == I.HeaderNode;
  }

  bool isLoop() const;

  void print(raw_ostream &O) const;
};

inline Interval::succ_iterator succ_begin(Interval *I) {
  return I->Successors.begin();
}
inline Interval::succ_iterator succ_end(Interval *I)   {
  return I->Successors.end();
}

inline Interval::pred_iterator pred_begin(Interval *I) {
  return I->Predecessors.begin();
}
inline Interval::pred_iterator pred_end(Interval *I)   {
  return I->Predecessors.end();
}

template <> struct GraphTraits<Interval*> {
  typedef Interval NodeType;
  typedef Interval::succ_iterator ChildIteratorType;

  static NodeType *getEntryNode(Interval *I) { return I; }

  static inline ChildIteratorType child_begin(NodeType *N) {
    return succ_begin(N);
  }
  static inline ChildIteratorType child_end(NodeType *N) {
    return succ_end(N);
  }
};

template <> struct GraphTraits<Inverse<Interval*> > {
  typedef Interval NodeType;
  typedef Interval::pred_iterator ChildIteratorType;
  static NodeType *getEntryNode(Inverse<Interval *> G) { return G.Graph; }
  static inline ChildIteratorType child_begin(NodeType *N) {
    return pred_begin(N);
  }
  static inline ChildIteratorType child_end(NodeType *N) {
    return pred_end(N);
  }
};

} // End llvm namespace

#endif

---