src/libvpsc/constraint.h

   1 /**
   2  * \brief A constraint determines a minimum or exact spacing required between
   3  * two variables.
   4  *
   5  * Authors:
   6  *   Tim Dwyer <tgdwyer@gmail.com>
   7  *
   8  * Copyright (C) 2005 Authors
   9  *
  10  * Released under GNU LGPL.  Read the file 'COPYING' for more information.
  11  */
  12
  13 #ifndef SEEN_REMOVEOVERLAP_CONSTRAINT_H
  14 #define SEEN_REMOVEOVERLAP_CONSTRAINT_H
  15
  16 #include <iostream>
  17 #include "variable.h"
  18 namespace vpsc {
  19
  20 class Constraint
  21 {
  22         friend std::ostream& operator <<(std::ostream &os,const Constraint &c);
  23 public:
  24         Variable *left;
  25         Variable *right;
  26         double gap;
  27         double lm;
  28         Constraint(Variable *left, Variable *right, double gap, bool equality=false);
  29     virtual ~Constraint();
  30         inline double slack() const { return right->position() - gap - left->position(); }
  31         long timeStamp;
  32         bool active;
  33         bool visited;
  34         bool equality;
  35 };
  36 #include <float.h>
  37 #include "block.h"
  38 static inline bool compareConstraints(Constraint *const &l, Constraint *const &r) {
  39         double const sl =
  40                 l->left->block->timeStamp > l->timeStamp
  41                 ||l->left->block==l->right->block
  42                 ?-DBL_MAX:l->slack();
  43         double const sr =
  44                 r->left->block->timeStamp > r->timeStamp
  45                 ||r->left->block==r->right->block
  46                 ?-DBL_MAX:r->slack();
  47         if(sl==sr) {
  48                 // arbitrary choice based on id
  49                 if(l->left->id==r->left->id) {
  50                         if(l->right->id<r->right->id) return true;
  51                         return false;
  52                 }
  53                 if(l->left->id<r->left->id) return true;
  54                 return false;
  55         }
  56         return sl < sr;
  57 }
  58 }
  59
  60 #endif // SEEN_REMOVEOVERLAP_CONSTRAINT_H