#ifndef ANDERSEN_CONSTRAINT_H

#define ANDERSEN_CONSTRAINT_H

#include "NodeFactory.h"

#include <cassert>

/// AndersConstraint - Objects of this structure are used to represent the

/// various constraints identified by the algorithm.  The constraints are

/// 'copy', for statements like "A = B", 'load' for statements like "A = *B",

/// 'store' for statements like "*A = B", and AddressOf for statements like A =

/// alloca;  The Offset is applied as *(A + K) = B for stores, A = *(B + K) for

/// loads, and A = B + K for copies.  It is illegal on addressof constraints

/// (because it is statically resolvable to A = &C where C = B + K)

class AndersConstraint {

public:

  enum ConstraintType {

    ADDR_OF,

    COPY,

    LOAD,

    STORE,

  };

private:

  ConstraintType type;

  NodeIndex dest;

  NodeIndex src;

public:

  AndersConstraint(ConstraintType Ty, NodeIndex D, NodeIndex S)

      : type(Ty), dest(D), src(S) {}

  ConstraintType getType() const { return type; }

  NodeIndex getDest() const { return dest; }

  NodeIndex getSrc() const { return src; }

  bool operator==(AndersConstraint const &RHS) const {

    return RHS.type == type && RHS.dest == dest && RHS.src == src;

  }

  bool operator!=(AndersConstraint const &RHS) const { return !(*this == RHS); }

  bool operator<(AndersConstraint const &RHS) const {

    if (RHS.type != type)

      return RHS.type < type;

    else if (RHS.dest != dest)

      return RHS.dest < dest;

    return RHS.src < src;

  }

};

#endif