simulation.cc 42.3 KB
Newer Older
Thomas Badie's avatar
Thomas Badie committed
1
// -*- coding: utf-8 -*-
2
// Copyright (C) 2012, 2013, 2014 Laboratoire de Recherche et Développement
Thomas Badie's avatar
Thomas Badie committed
3
// de l'Epita (LRDE).
Thomas Badie's avatar
Thomas Badie committed
4
5
6
7
8
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
9
// the Free Software Foundation; either version 3 of the License, or
Thomas Badie's avatar
Thomas Badie committed
10
11
12
13
14
15
16
17
// (at your option) any later version.
//
// Spot is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
18
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
Thomas Badie's avatar
Thomas Badie committed
19
20
21
22

#include <queue>
#include <map>
#include <utility>
Thomas Badie's avatar
Thomas Badie committed
23
24
#include <cmath>
#include <limits>
Thomas Badie's avatar
Thomas Badie committed
25
#include "simulation.hh"
26
#include "priv/acccompl.hh"
Thomas Badie's avatar
Thomas Badie committed
27
28
29
#include "misc/minato.hh"
#include "tgba/bddprint.hh"
#include "tgbaalgos/reachiter.hh"
30
#include "tgbaalgos/sccfilter.hh"
Thomas Badie's avatar
Thomas Badie committed
31
32
#include "tgbaalgos/scc.hh"
#include "tgbaalgos/dupexp.hh"
Thomas Badie's avatar
Thomas Badie committed
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64

// The way we developed this algorithm is the following: We take an
// automaton, and reverse all these acceptance conditions.  We reverse
// them to go make the meaning of the signature easier. We are using
// bdd, and we want to let it make all the simplification. Because of
// the format of the acceptance condition, it doesn't allow easy
// simplification. Instead of encoding them as: "a!b!c + !ab!c", we
// use them as: "ab". We complement them because we want a
// simplification if the condition of the transition A implies the
// transition of B, and if the acceptance condition of A is included
// in the acceptance condition of B. To let the bdd makes the job, we
// revert them.

// Then, to check if a transition i-dominates another, we'll use the bdd:
// "sig(transA) = cond(trans) & acc(trans) & implied(class(trans->state))"
// Idem for sig(transB). The 'implied'
// (represented by a hash table 'relation_' in the implementation) is
// a conjunction of all the class dominated by the class of the
// destination. This is how the relation is included in the
// signature. It makes the simplifications alone, and the work is
// done.  The algorithm is cut into several step:
//
// 1. Run through the tgba and switch the acceptance condition to their
//    negation, and initializing relation_ by the 'init_ -> init_' where
//    init_ is the bdd which represents the class. This function is the
//    constructor of Simulation.
// 2. Enter in the loop (run).
//    - Rename the class.
//    - run through the automaton and computing the signature of each
//      state. This function is `update_sig'.
//    - Enter in a double loop to adapt the partial order, and set
//      'relation_' accordingly. This function is `update_po'.
65
// 3. Rename the class (to actualize the name in the previous_class and
Thomas Badie's avatar
Thomas Badie committed
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
//    in relation_).
// 4. Building an automaton with the result, with the condition:
// "a transition in the original automaton appears in the simulated one
// iff this transition is included in the set of i-maximal neighbour."
// This function is `build_output'.
// The automaton simulated is recomplemented to come back to its initial
// state when the object Simulation is destroyed.
//
// Obviously these functions are possibly cut into several little one.
// This is just the general development idea.

// How to use isop:
// I need all variable non_acceptance & non_class.
// bdd_support(sig(X)): All var
// bdd_support(sig(X)) - allacc - allclassvar


Thomas Badie's avatar
Thomas Badie committed
83
84
85
86
// TODO LIST: Play on the order of the selection in the
// dont_care_simulation. The good place to work is in add_to_map_imply.


Thomas Badie's avatar
Thomas Badie committed
87
88
89
90
91
92
93
namespace spot
{
  namespace
  {
    // Some useful typedef:

    // Used to get the signature of the state.
94
    typedef std::vector<bdd> vector_state_bdd;
Thomas Badie's avatar
Thomas Badie committed
95

96
97
    typedef std::vector<const state*> vector_state_state;

Thomas Badie's avatar
Thomas Badie committed
98

Thomas Badie's avatar
Thomas Badie committed
99
    // Get the list of state for each class.
100
    typedef std::map<bdd, std::list<unsigned>,
Thomas Badie's avatar
Thomas Badie committed
101
102
                     bdd_less_than> map_bdd_lstate;

103
    typedef std::map<bdd, unsigned, bdd_less_than> map_bdd_state;
Thomas Badie's avatar
Thomas Badie committed
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

    // Our constraint: (state_src, state_dst) = to_add.
    // We define the couple of state as the key of the constraint.
    typedef std::pair<const state*, const state*> constraint_key;

    // But we need a comparator for that key.
    struct constraint_key_comparator
    {
      bool operator()(const constraint_key& l,
                      const constraint_key& r) const
      {
        if (l.first->compare(r.first) < 0)
          return true;
        else
          if (l.first->compare(r.first) > 0)
            return false;

        if (l.second->compare(r.second) < 0)
          return true;
        else
          if (l.second->compare(r.second) > 0)
            return false;

        return false;
      }
    };

    // The full definition of the constraint.
    typedef std::map<constraint_key, bdd,
                     constraint_key_comparator> map_constraint;

135
    typedef std::tuple<const state*, const state*, bdd> constraint;
Thomas Badie's avatar
Thomas Badie committed
136
137
138
139
140
141

    // Helper to create the map of constraints to give to the
    // simulation.
    void add_to_map(const std::list<constraint>& list,
                    map_constraint& feed_me)
    {
142
      for (auto& p: list)
143
144
145
	feed_me.emplace(std::make_pair(std::get<0>(p),
				       std::get<1>(p)),
			std::get<2>(p));
Thomas Badie's avatar
Thomas Badie committed
146
147
148
149
150
    }


    // This class helps to compare two automata in term of
    // size.
151
152
153
154
155
156
157
158
    struct automaton_size
    {
      automaton_size()
        : transitions(0),
          states(0)
      {
      }

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
159
      inline bool operator!=(const automaton_size& r)
160
161
162
163
      {
        return transitions != r.transitions || states != r.states;
      }

Thomas Badie's avatar
Thomas Badie committed
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
      inline bool operator<(const automaton_size& r)
      {
        if (states < r.states)
          return true;
        if (states > r.states)
          return false;

        if (transitions < r.transitions)
          return true;
        if (transitions > r.transitions)
          return false;

        return false;
      }

      inline bool operator>(const automaton_size& r)
      {
        if (states < r.states)
          return false;
        if (states > r.states)
          return true;

        if (transitions < r.transitions)
          return false;
        if (transitions > r.transitions)
          return true;

        return false;
      }

194
195
196
      int transitions;
      int states;
    };
Thomas Badie's avatar
Thomas Badie committed
197

Thomas Badie's avatar
Thomas Badie committed
198
    // The direct_simulation. If Cosimulation is true, we are doing a
199
200
    // cosimulation.
    template <bool Cosimulation, bool Sba>
201
    class direct_simulation
Thomas Badie's avatar
Thomas Badie committed
202
    {
Thomas Badie's avatar
Thomas Badie committed
203
    protected:
204
205
206
      // Shortcut used in update_po and go_to_next_it.
      typedef std::map<bdd, bdd, bdd_less_than> map_bdd_bdd;
    public:
Thomas Badie's avatar
Thomas Badie committed
207
208
209
210
211
      direct_simulation(const tgba* t, const map_constraint* map_cst = 0)
        : a_(0),
          po_size_(0),
          all_class_var_(bddtrue),
          map_cst_(map_cst),
212
          original_(t)
213
      {
Thomas Badie's avatar
Thomas Badie committed
214
215
216
217
218
219
220
221
222
223
        // We need to do a dupexp for being able to run scc_map later.
        // new_original_ is the map that contains the relation between
        // the names (addresses) of the states in the automaton
        // returned by dupexp, and in automaton given in argument to
        // the constructor.
        a_ = tgba_dupexp_dfs(t, new_original_);
        scc_map_ = new scc_map(a_);
        scc_map_->build_map();
        old_a_ = a_;

224

225
226
	acc_compl ac(a_->all_acceptance_conditions(),
		     a_->neg_acceptance_conditions());
227

228
229
230
231
232
233
234
235
236
237
	// Replace all the acceptance conditions by their complements.
	// (In the case of Cosimulation, we also flip the transitions.)
	{
	  if (Cosimulation)
	    {
	      bdd_dict* bd = a_->get_dict();
	      a_ = new tgba_digraph(bd);
	      bd->register_all_variables_of(old_a_, a_);
	      a_->copy_acceptance_conditions_of(old_a_);
	    }
238
	  unsigned ns = old_a_->num_states();
239
	  if (Cosimulation)
240
	    a_->new_states(ns);
241
242
	  for (unsigned s = 0; s < ns; ++s)
	    {
243
	      for (auto& t: old_a_->out(s))
244
245
246
247
248
249
250
251
252
253
254
		{
		  bdd acc;
		  if (Sba && Cosimulation)
		    {
		      // If the acceptance is interpreted as
		      // state-based, to apply the reverse simulation
		      // on a SBA, we should pull the acceptance of
		      // the destination state on its incoming arcs
		      // (which now become outgoing arcs after
		      // transposition).
		      acc = bddfalse;
255
		      for (auto& td: old_a_->out(t.dst))
256
257
258
259
260
261
262
263
264
265
			{
			  acc = ac.complement(td.acc);
			  break;
			}
		    }
		  else
		    {
		      acc = ac.complement(t.acc);
		    }
		  if (Cosimulation)
266
		    a_->new_transition(t.dst, s, t.cond, acc);
267
268
269
270
271
272
		  else
		    t.acc = acc;
		}
	    }
	  size_a_ = ns;
	}
273
274
275
276
277

	// Now, we have to get the bdd which will represent the
	// class. We register one bdd by state, because in the worst
	// case, |Class| == |State|.
	unsigned set_num = a_->get_dict()
278
	  ->register_anonymous_variables(size_a_ + 1, this);
279

280
281
        all_acceptance_conditions_ = a_->all_acceptance_conditions();
        all_proms_ = bdd_support(all_acceptance_conditions_);
Thomas Badie's avatar
Thomas Badie committed
282

Thomas Badie's avatar
Thomas Badie committed
283
284
        bdd_initial = bdd_ithvar(set_num++);
	bdd init = bdd_ithvar(set_num++);
285
286
287

	used_var_.push_back(init);

288
289
290
291
	// Initialize all classes to init.
	previous_class_.resize(size_a_);
	for (unsigned s = 0; s < size_a_; ++s)
	  previous_class_[s] = init;
Thomas Badie's avatar
Thomas Badie committed
292

293
294
295
296
	// Put all the anonymous variable in a queue, and record all
	// of these in a variable all_class_var_ which will be used
	// to understand the destination part in the signature when
	// building the resulting automaton.
297
	all_class_var_ = init;
298
	for (unsigned i = set_num; i < set_num + size_a_ - 1; ++i)
Thomas Badie's avatar
Thomas Badie committed
299
300
301
302
303
          {
            free_var_.push(i);
            all_class_var_ &= bdd_ithvar(i);
          }

304
305
	relation_[init] = init;
      }
Thomas Badie's avatar
Thomas Badie committed
306
307


308
309
310
      // Reverse all the acceptance condition at the destruction of
      // this object, because it occurs after the return of the
      // function simulation.
Thomas Badie's avatar
Thomas Badie committed
311
      virtual ~direct_simulation()
312
      {
313
	a_->get_dict()->unregister_all_my_variables(this);
Thomas Badie's avatar
Thomas Badie committed
314
        delete scc_map_;
315

316
	delete old_a_;
317
        // a_ is a new automaton only if we are doing a cosimulation.
Thomas Badie's avatar
Thomas Badie committed
318
319
        if (Cosimulation)
          delete a_;
320
      }
Thomas Badie's avatar
Thomas Badie committed
321

322
      // Update the name of the classes.
323
324
325
326
327
328
      void update_previous_class()
      {
	std::list<bdd>::iterator it_bdd = used_var_.begin();

	// We run through the map bdd/list<state>, and we update
	// the previous_class_ with the new data.
329
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
330
          {
331
332
333
334
335
336
337
338
	    // If the signature of a state is bddfalse (no
	    // transitions) the class of this state is bddfalse
	    // instead of an anonymous variable. It allows
	    // simplifications in the signature by removing a
	    // transition which has as a destination a state with
	    // no outgoing transition.
	    if (p.first == bddfalse)
	      for (auto s: p.second)
339
		previous_class_[s] = bddfalse;
340
341
	    else
	      for (auto s: p.second)
342
		previous_class_[s] = *it_bdd;
343
	    ++it_bdd;
Thomas Badie's avatar
Thomas Badie committed
344
          }
345
346
      }

Thomas Badie's avatar
Thomas Badie committed
347
      void main_loop()
348
349
350
351
352
      {
	unsigned int nb_partition_before = 0;
	unsigned int nb_po_before = po_size_ - 1;
	while (nb_partition_before != bdd_lstate_.size()
	       || nb_po_before != po_size_)
Thomas Badie's avatar
Thomas Badie committed
353
          {
354
            update_previous_class();
Thomas Badie's avatar
Thomas Badie committed
355
356
357
358
359
360
361
362
            nb_partition_before = bdd_lstate_.size();
            bdd_lstate_.clear();
            nb_po_before = po_size_;
            po_size_ = 0;
            update_sig();
            go_to_next_it();
          }

363
	update_previous_class();
Thomas Badie's avatar
Thomas Badie committed
364
365
366
      }

      // The core loop of the algorithm.
367
      tgba_digraph* run()
Thomas Badie's avatar
Thomas Badie committed
368
369
      {
        main_loop();
370
371
	return build_result();
      }
Thomas Badie's avatar
Thomas Badie committed
372

373
      // Take a state and compute its signature.
374
      bdd compute_sig(unsigned src)
375
      {
Thomas Badie's avatar
Thomas Badie committed
376
        bdd res = bddfalse;
Thomas Badie's avatar
Thomas Badie committed
377

378
        for (auto& t: a_->out(src))
Thomas Badie's avatar
Thomas Badie committed
379
          {
Thomas Badie's avatar
Thomas Badie committed
380
            bdd acc = bddtrue;
Thomas Badie's avatar
Thomas Badie committed
381

382
	    map_constraint::const_iterator it;
383
384
	    // Check if we have a constraint about this edge in the
	    // original automaton.
385
386
	    if (map_cst_
		&& ((it = map_cst_
387
388
		     ->find(std::make_pair(new_original_[src],
					   new_original_[t.dst])))
389
390
391
392
393
394
		    != map_cst_->end()))
	      {
		acc = it->second;
	      }
	    else
	      {
395
		acc = t.acc;
396
397
398
399
400
	      }

	    // to_add is a conjunction of the acceptance condition,
	    // the label of the transition and the class of the
	    // destination and all the class it implies.
401
	    bdd to_add = acc & t.cond & relation_[previous_class_[t.dst]];
Thomas Badie's avatar
Thomas Badie committed
402

403
404
	    res |= to_add;
	  }
Thomas Badie's avatar
Thomas Badie committed
405

Thomas Badie's avatar
Thomas Badie committed
406
        // When we Cosimulate, we add a special flag to differentiate
407
        // the initial state from the other.
408
        if (Cosimulation && src == 0)
Thomas Badie's avatar
Thomas Badie committed
409
410
411
          res |= bdd_initial;

        return res;
412
413
      }

Thomas Badie's avatar
Thomas Badie committed
414

415
416
      void update_sig()
      {
417
	for (unsigned s = 0; s < size_a_; ++s)
418
	  bdd_lstate_[compute_sig(s)].push_back(s);
419
      }
Thomas Badie's avatar
Thomas Badie committed
420
421


422
423
424
425
      // This method rename the color set, update the partial order.
      void go_to_next_it()
      {
	int nb_new_color = bdd_lstate_.size() - used_var_.size();
Thomas Badie's avatar
Thomas Badie committed
426

Thomas Badie's avatar
Thomas Badie committed
427
428
429

        // If we have created more partitions, we need to use more
        // variables.
430
	for (int i = 0; i < nb_new_color; ++i)
Thomas Badie's avatar
Thomas Badie committed
431
432
433
434
435
436
          {
            assert(!free_var_.empty());
            used_var_.push_back(bdd_ithvar(free_var_.front()));
            free_var_.pop();
          }

Thomas Badie's avatar
Thomas Badie committed
437
438
439

        // If we have reduced the number of partition, we 'free' them
        // in the free_var_ list.
440
441
442
443
444
445
446
447
448
449
450
	for (int i = 0; i > nb_new_color; --i)
          {
            assert(!used_var_.empty());
            free_var_.push(bdd_var(used_var_.front()));
            used_var_.pop_front();
          }


	assert((bdd_lstate_.size() == used_var_.size())
               || (bdd_lstate_.find(bddfalse) != bdd_lstate_.end()
                   && bdd_lstate_.size() == used_var_.size() + 1));
Thomas Badie's avatar
Thomas Badie committed
451

452
453
454
455
456
457
458
	// Now we make a temporary hash_table which links the tuple
	// "C^(i-1), N^(i-1)" to the new class coloring.  If we
	// rename the class before updating the partial order, we
	// loose the information, and if we make it after, I can't
	// figure out how to apply this renaming on rel_.
	// It adds a data structure but it solves our problem.
	map_bdd_bdd now_to_next;
Thomas Badie's avatar
Thomas Badie committed
459

460
	std::list<bdd>::iterator it_bdd = used_var_.begin();
Thomas Badie's avatar
Thomas Badie committed
461

462
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
463
          {
464
465
466
467
468
469
	    // If the signature of a state is bddfalse (no
	    // transitions) the class of this state is bddfalse
	    // instead of an anonymous variable. It allows
	    // simplifications in the signature by removing a
	    // transition which has as a destination a state with
	    // no outgoing transition.
470
471
472
473
	    bdd acc = bddfalse;
	    if (p.first != bddfalse)
	      acc = *it_bdd;
	    now_to_next[p.first] = acc;
474
	    ++it_bdd;
Thomas Badie's avatar
Thomas Badie committed
475
476
          }

Thomas Badie's avatar
Thomas Badie committed
477
	update_po(now_to_next, relation_);
478
479
      }

Thomas Badie's avatar
Thomas Badie committed
480
481
482
483
484
485
486
487
488
      // This function computes the new po with previous_class_ and
      // the argument. `now_to_next' contains the relation between the
      // signature and the future name of the class.  We need a
      // template parameter because we use this function with a
      // map_bdd_bdd, but later, we need a list_bdd_bdd. So to
      // factorize some code we use a template.
      template <typename container_bdd_bdd>
      void update_po(const container_bdd_bdd& now_to_next,
                     map_bdd_bdd& relation)
489
490
491
492
493
494
495
496
      {
	// This loop follows the pattern given by the paper.
	// foreach class do
	// |  foreach class do
	// |  | update po if needed
	// |  od
	// od

Thomas Badie's avatar
Thomas Badie committed
497
498
	for (typename container_bdd_bdd::const_iterator it1
               = now_to_next.begin();
499
500
	     it1 != now_to_next.end();
	     ++it1)
Thomas Badie's avatar
Thomas Badie committed
501
502
          {
            bdd accu = it1->second;
Thomas Badie's avatar
Thomas Badie committed
503
504
            for (typename container_bdd_bdd::const_iterator it2
                   = now_to_next.begin();
Thomas Badie's avatar
Thomas Badie committed
505
506
                 it2 != now_to_next.end();
                 ++it2)
Thomas Badie's avatar
Thomas Badie committed
507
508
509
510
511
512
513
514
515
516
517
              {
                // Skip the case managed by the initialization of accu.
                if (it1 == it2)
                  continue;

                if (bdd_implies(it1->first, it2->first))
                  {
                    accu &= it2->second;
                    ++po_size_;
                  }
              }
Thomas Badie's avatar
Thomas Badie committed
518
            relation[it1->second] = accu;
Thomas Badie's avatar
Thomas Badie committed
519
          }
520
521
      }

522
523
524
525
526
527
528
      automaton_size get_stat() const
      {
        assert(stat.states != 0);

        return stat;
      }

Thomas Badie's avatar
Thomas Badie committed
529
530
531
532
533
534
535
536
      bool result_is_deterministic() const
      {
        assert(stat.states != 0);

        return res_is_deterministic;
      }


537

538
      // Build the minimal resulting automaton.
539
      tgba_digraph* build_result()
540
541
542
543
544
545
      {
	// We have all the a_'s acceptances conditions
	// complemented.  So we need to complement it when adding a
	// transition.  We *must* keep the complemented because it
	// is easy to know if an acceptance condition is maximal or
	// not.
Thomas Badie's avatar
Thomas Badie committed
546
	acc_compl reverser(all_acceptance_conditions_,
547
548
			   a_->neg_acceptance_conditions());

549
	bdd_dict* d = a_->get_dict();
550
	tgba_digraph* res = new tgba_digraph(d);
551
552
	d->register_all_variables_of(a_, res);
	res->set_acceptance_conditions(all_acceptance_conditions_);
553
554
	if (Sba)
	  res->set_bprop(tgba_digraph::StateBasedAcc);
555

Thomas Badie's avatar
Thomas Badie committed
556
	bdd sup_all_acc = bdd_support(all_acceptance_conditions_);
557
558
559
	// Non atomic propositions variables (= acc and class)
	bdd nonapvars = sup_all_acc & bdd_support(all_class_var_);

560
561
	auto* gb = res->create_namer<int>();

562
	// Create one state per partition.
563
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
564
          {
565
566
567
568
569
            bdd cl = previous_class_[p.second.front()];
	    // A state may be referred to either by
	    // its class, or by all the implied classes.
	    auto s = gb->new_state(cl.id());
	    gb->alias_state(s, relation_[cl].id());
Thomas Badie's avatar
Thomas Badie committed
570
571
          }

572
573
574
	// Acceptance of states.  Only used if Sba && Cosimulation.
	std::vector<bdd> accst;
	if (Sba && Cosimulation)
575
	  accst.resize(res->num_states(), bddfalse);
576

577
578
579
        stat.states = bdd_lstate_.size();
        stat.transitions = 0;

Thomas Badie's avatar
Thomas Badie committed
580
581
582
        unsigned nb_satoneset = 0;
        unsigned nb_minato = 0;

583
	// For each class, we will create
584
	// all the transitions between the states.
585
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
586
          {
587
588
589
590
591
	    // All states in p.second have the same class, so just
	    // pick the class of the first one first one.
	    bdd src = previous_class_[p.second.front()];

            // Get the signature to derive successors.
592
            bdd sig = compute_sig(p.second.front());
Thomas Badie's avatar
Thomas Badie committed
593

Thomas Badie's avatar
Thomas Badie committed
594
595
596
            if (Cosimulation)
              sig = bdd_compose(sig, bddfalse, bdd_var(bdd_initial));

Thomas Badie's avatar
Thomas Badie committed
597
598
599
600
601
602
603
604
605
606
607
608
609
            // Get all the variable in the signature.
            bdd sup_sig = bdd_support(sig);

            // Get the variable in the signature which represents the
            // conditions.
            bdd sup_all_atomic_prop = bdd_exist(sup_sig, nonapvars);

            // Get the part of the signature composed only with the atomic
            // proposition.
            bdd all_atomic_prop = bdd_exist(sig, nonapvars);

	    // First loop over all possible valuations atomic properties.
            while (all_atomic_prop != bddfalse)
610
611
612
613
614
615
	      {
		bdd one = bdd_satoneset(all_atomic_prop,
					sup_all_atomic_prop,
					bddtrue);
		all_atomic_prop -= one;

616
		// For each possible valuation, iterate over all possible
617
618
619
620
621
622
623
624
625
		// destination classes.   We use minato_isop here, because
		// if the same valuation of atomic properties can go
		// to two different classes C1 and C2, iterating on
		// C1 + C2 with the above bdd_satoneset loop will see
		// C1 then (!C1)C2, instead of C1 then C2.
		// With minatop_isop, we ensure that the no negative
		// class variable will be seen (likewise for promises).
		minato_isop isop(sig & one);

Thomas Badie's avatar
Thomas Badie committed
626
627
                ++nb_satoneset;

628
629
630
		bdd cond_acc_dest;
		while ((cond_acc_dest = isop.next()) != bddfalse)
		  {
631
632
                    ++stat.transitions;

Thomas Badie's avatar
Thomas Badie committed
633
634
                    ++nb_minato;

635
636
		    // Take the transition, and keep only the variable which
		    // are used to represent the class.
637
		    bdd dst = bdd_existcomp(cond_acc_dest,
638
639
640
641
642
					     all_class_var_);

		    // Keep only ones who are acceptance condition.
		    bdd acc = bdd_existcomp(cond_acc_dest, sup_all_acc);

643
		    // Keep the other!
644
645
646
647
		    bdd cond = bdd_existcomp(cond_acc_dest,
					     sup_all_atomic_prop);

		    // Because we have complemented all the acceptance
648
649
		    // conditions on the input automaton, we must
		    // revert them to create a new transition.
650
651
		    acc = reverser.reverse_complement(acc);

652
653
654
		    if (Cosimulation)
		      {
			if (Sba)
655
656
657
658
659
660
661
662
663
664
			  {
			    // acc should be attached to src, or rather,
			    // in our transition-based representation)
			    // to all transitions leaving src.  As we
			    // can't do this here, store this in a table
			    // so we can fix it later.
			    accst[gb->get_state(src.id())] = acc;
			    acc = bddfalse;
			  }
			gb->new_transition(dst.id(), src.id(), cond, acc);
665
		      }
666
		    else
667
668
669
		      {
			gb->new_transition(src.id(), dst.id(), cond, acc);
		      }
670
671
		  }
	      }
Thomas Badie's avatar
Thomas Badie committed
672
673
          }

674
675
	res->set_init_state(gb->get_state(previous_class_
					  [a_->get_init_state_number()].id()));
Thomas Badie's avatar
Thomas Badie committed
676

677
	res->merge_transitions(); // FIXME: is this really needed?
Thomas Badie's avatar
Thomas Badie committed
678

679
680
681
	// Mark all accepting state in a second pass, when
	// dealing with SBA in cosimulation.
	if (Sba && Cosimulation)
682
683
684
685
686
687
688
	  {
	    unsigned ns = res->num_states();
	    for (unsigned s = 0; s < ns; ++s)
	      {
		bdd acc = accst[s];
		if (acc == bddfalse)
		  continue;
689
		for (auto& t: res->out(s))
690
691
692
		  t.acc = acc;
	      }
	  }
693

694
	delete gb;
Thomas Badie's avatar
Thomas Badie committed
695
696
        res_is_deterministic = nb_minato == nb_satoneset;

697
698
699
700
701
702
703
704
705
706
707
	return res;
      }


      // Debug:
      // In a first time, print the signature, and the print a list
      // of each state in this partition.
      // In a second time, print foreach state, who is where,
      // where is the new class name.
      void print_partition()
      {
708
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
709
710
          {
            std::cerr << "partition: "
711
                      << bdd_format_isop(a_->get_dict(), p.first)
Thomas Badie's avatar
Thomas Badie committed
712
                      << std::endl;
713
            for (auto s: p.second)
714
715
716
	      std::cerr << "  - "
			<< a_->format_state(a_->state_from_number(s))
			<< '\n';
Thomas Badie's avatar
Thomas Badie committed
717
718
          }

719
	std::cerr << "\nPrevious iteration\n" << std::endl;
Thomas Badie's avatar
Thomas Badie committed
720

721
722
	unsigned ps = previous_class_.size();
	for (unsigned p = 0; p < ps; ++p)
Thomas Badie's avatar
Thomas Badie committed
723
          {
724
            std::cerr << a_->format_state(a_->state_from_number(p))
Thomas Badie's avatar
Thomas Badie committed
725
                      << " was in "
726
                      << bdd_format_set(a_->get_dict(), previous_class_[p])
727
                      << '\n';
Thomas Badie's avatar
Thomas Badie committed
728
          }
729
      }
Thomas Badie's avatar
Thomas Badie committed
730

Thomas Badie's avatar
Thomas Badie committed
731
    protected:
732
      // The automaton which is simulated.
733
734
      tgba_digraph* a_;
      tgba_digraph* old_a_;
Thomas Badie's avatar
Thomas Badie committed
735

736
737
738
739
740
741
742
      // Relation is aimed to represent the same thing than
      // rel_. The difference is in the way it does.
      // If A => A /\ A => B, rel will be (!A U B), but relation_
      // will have A /\ B at the key A. This trick is due to a problem
      // with the computation of the resulting automaton with the signature.
      // rel_ will pollute the meaning of the signature.
      map_bdd_bdd relation_;
Thomas Badie's avatar
Thomas Badie committed
743

744
      // Represent the class of each state at the previous iteration.
745
      vector_state_bdd previous_class_;
Thomas Badie's avatar
Thomas Badie committed
746

747
748
749
      // The list of state for each class at the current_iteration.
      // Computed in `update_sig'.
      map_bdd_lstate bdd_lstate_;
Thomas Badie's avatar
Thomas Badie committed
750

751
752
753
      // The queue of free bdd. They will be used as the identifier
      // for the class.
      std::queue<int> free_var_;
Thomas Badie's avatar
Thomas Badie committed
754

755
756
      // The list of used bdd. They are in used as identifier for class.
      std::list<bdd> used_var_;
Thomas Badie's avatar
Thomas Badie committed
757

758
759
      // Size of the automaton.
      unsigned int size_a_;
Thomas Badie's avatar
Thomas Badie committed
760

761
762
763
      // Used to know when there is no evolution in the po. Updated
      // in the `update_po' method.
      unsigned int po_size_;
Thomas Badie's avatar
Thomas Badie committed
764

765
766
      // All the class variable:
      bdd all_class_var_;
Thomas Badie's avatar
Thomas Badie committed
767
768
769
770

      // The flag to say if the outgoing state is initial or not
      bdd bdd_initial;

Thomas Badie's avatar
Thomas Badie committed
771
772
      bdd all_proms_;

773
      automaton_size stat;
774

Thomas Badie's avatar
Thomas Badie committed
775
      scc_map* scc_map_;
776
      std::vector<const state*> new_original_;
Thomas Badie's avatar
Thomas Badie committed
777
778
779
780
781
782
783
784
785
786
787

      const map_constraint* map_cst_;

      const tgba* original_;

      bdd all_acceptance_conditions_;

      bool res_is_deterministic;
    };

    // For now, we don't try to handle cosimulation.
788
    class direct_simulation_dont_care: public direct_simulation<false, false>
Thomas Badie's avatar
Thomas Badie committed
789
790
791
792
793
794
795
796
797
798
799
800
    {
      typedef std::vector<std::list<constraint> > constraints;
      typedef std::map<bdd,                  // Source Class.
                       std::map<bdd,         // Destination (implied) Class.
                                std::list<constraint>, // Constraints list.
                                bdd_less_than>,
                       bdd_less_than> constraint_list;
      typedef std::list<std::pair<bdd, bdd> > list_bdd_bdd;


    public:
      direct_simulation_dont_care(const tgba* t)
801
      : direct_simulation<false, false>(t)
Thomas Badie's avatar
Thomas Badie committed
802
803
804
      {
        // This variable is used in the new signature.
        on_cycle_ =
805
          bdd_ithvar(a_->get_dict()->register_anonymous_variables(1, this));
Thomas Badie's avatar
Thomas Badie committed
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824

        // This one is used for the iteration on all the
        // possibilities. Avoid computing two times "no constraints".
        empty_seen_ = false;


        // If this variable is set to true, we have a number limit of
        // simulation to run.
        has_limit_ = false;

	notap = (bdd_support(all_acceptance_conditions_)
                 & all_class_var_ & on_cycle_);
      }

      // This function computes the don't care signature of the state
      // src. This signature is similar to the classic one, excepts
      // that if the transition is on a SCC, we add a on_cycle_ on it,
      // otherwise we add !on_cycle_. This allows us to split the
      // signature later.
825
      bdd dont_care_compute_sig(unsigned src)
Thomas Badie's avatar
Thomas Badie committed
826
827
828
      {
        bdd res = bddfalse;

829
        unsigned scc = scc_map_->scc_of_state(old_a_->state_from_number(src));
Thomas Badie's avatar
Thomas Badie committed
830
831
        bool sccacc = scc_map_->accepting(scc);

832
	for (auto& t: a_->out(src))
Thomas Badie's avatar
Thomas Badie committed
833
          {
834
            bdd cl = previous_class_[t.dst];
Thomas Badie's avatar
Thomas Badie committed
835
836
            bdd acc;

837
            if (scc != scc_map_->scc_of_state(old_a_->state_from_number(t.dst)))
Thomas Badie's avatar
Thomas Badie committed
838
839
              acc = !on_cycle_;
            else if (sccacc)
840
              acc = on_cycle_ & t.acc;
Thomas Badie's avatar
Thomas Badie committed
841
842
843
            else
              acc = on_cycle_ & all_proms_;

844
            bdd to_add = acc & t.cond & relation_[cl];
Thomas Badie's avatar
Thomas Badie committed
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
            res |= to_add;
          }
        return res;
      }

      // We used to have
      //   sig(s1) = (f1 | g1)
      //   sig(s2) = (f2 | g2)
      // and we say that s2 simulates s1 if sig(s1)=>sig(s2).
      // This amount to testing whether (f1|g1)=>(f2|g2),
      // which is equivalent to testing both
      //    f1=>(f2|g2)  and g1=>(f2|g2)
      // separately.
      //
      // Now we have a slightly improved version of this rule.
      // g1 and g2 are not on cycle, so they can make as many
      // promises as we wish, if that helps.  Adding promises
      // to g2 will not help, but adding promises to g1 can.
      //
      // So we test whether
      //    f1=>(f2|g2)
      //    g1=>noprom(f2|g2)
      // Where noprom(f2|g2) removes all promises from f2|g2.
      // (g1 do not have promises, and neither do g2).

      bool could_imply_aux(bdd f1, bdd g1, bdd left_class,
			   bdd right, bdd right_class)
      {
        (void) left_class;
        (void) right_class;

        bdd f2g2 = bdd_exist(right, on_cycle_);
        bdd f2g2n = bdd_exist(f2g2, all_proms_);

	bdd both = left_class & right_class;
	int lc = bdd_var(left_class);
        f1 = bdd_compose(f1, both, lc);
        g1 = bdd_compose(g1, both, lc);
        f2g2 = bdd_compose(f2g2, both, lc);
        f2g2n = bdd_compose(f2g2n, both, lc);

        return bdd_implies(f1, f2g2) && bdd_implies(g1, f2g2n);
      }

      bool could_imply(bdd left, bdd left_class,
		       bdd right, bdd right_class)
      {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
892
893
894
895
896
	bdd f1 = bdd_relprod(left, on_cycle_, on_cycle_);
	bdd g1 = bdd_relprod(left, !on_cycle_, on_cycle_);

        //bdd f1 = bdd_restrict(left, on_cycle_);
        //bdd g1 = bdd_restrict(left, !on_cycle_);
Thomas Badie's avatar
Thomas Badie committed
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
	return could_imply_aux(f1, g1, left_class,
			       right, right_class);
      }

      void dont_care_update_po(const list_bdd_bdd& now_to_next,
                               map_bdd_bdd& relation)
      {
        // This loop follows the pattern given by the paper.
        // foreach class do
        // |  foreach class do
        // |  | update po if needed
        // |  od
        // od

        for (list_bdd_bdd::const_iterator it1 = now_to_next.begin();
             it1 != now_to_next.end();
             ++it1)
          {
            bdd accu = it1->second;

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
917
918
919
920
921
	    bdd f1 = bdd_relprod(it1->first, on_cycle_, on_cycle_);
	    bdd g1 = bdd_relprod(it1->first, !on_cycle_, on_cycle_);

            // bdd f1 = bdd_restrict(it1->first_, on_cycle_);
            // bdd g1 = bdd_restrict(it1->first_, !on_cycle_);
Thomas Badie's avatar
Thomas Badie committed
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945

            for (list_bdd_bdd::const_iterator it2 = now_to_next.begin();
                 it2 != now_to_next.end();
                 ++it2)
              {
                // Skip the case managed by the initialization of accu.
                if (it1 == it2)
                  continue;

		if (could_imply_aux(f1, g1, it1->second,
				    it2->first, it2->second))
                  {
                    accu &= it2->second;
                    ++po_size_;
                  }
              }
            relation[it1->second] = accu;
          }
      }

#define ISOP(bdd) #bdd" - " << bdd_format_isop(a_->get_dict(), bdd)

      inline bool is_out_scc(bdd b)
      {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
946
947
	return bddfalse !=  bdd_relprod(b, !on_cycle_, on_cycle_);
        // return bddfalse != bdd_restrict(b, !on_cycle_);
Thomas Badie's avatar
Thomas Badie committed
948
949
950
951
952
953
954
955
956
957
      }

      // This method solves three kind of problems, where we have two
      // conjunctions of variable (that corresponds to a particular
      // transition), and where left could imply right.
      // Three cases:
      //   - αP₁ ⇒ xβP₁ where x is unknown.
      //   - xβP₁ ⇒ αP₁ where x is unknown.
      //   - xαP₁ ⇒ yβP₁ where x, y are unknown.
      void create_simple_constraint(bdd left, bdd right,
958
959
                                    unsigned src_left,
                                    unsigned src_right,
Thomas Badie's avatar
Thomas Badie committed
960
961
                                    std::list<constraint>& constraint)
      {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
962
	assert(src_left != src_right);
Thomas Badie's avatar
Thomas Badie committed
963
964
965
966
967
        // Determine which is the current case.
        bool out_scc_left = is_out_scc(left);
        bool out_scc_right = is_out_scc(right);
        bdd dest_class = bdd_existcomp(left, all_class_var_);
        assert(revert_relation_.find(dest_class) != revert_relation_.end());
968
        unsigned dst_left = revert_relation_[dest_class];
Thomas Badie's avatar
Thomas Badie committed
969
        dest_class = bdd_existcomp(right, all_class_var_);
970
        unsigned dst_right = revert_relation_[dest_class];
Thomas Badie's avatar
Thomas Badie committed
971

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
972
973
	assert(src_left != dst_left || src_right != dst_right);

Thomas Badie's avatar
Thomas Badie committed
974
975
976
977
978
979
980
981
982
983
984
        left = bdd_exist(left, all_class_var_ & on_cycle_);
        right = bdd_exist(right, all_class_var_ & on_cycle_);

        if (!out_scc_left && out_scc_right)
          {
            bdd b = bdd_exist(right, notap);
            bdd add = bdd_exist(left & b, bdd_support(b));

            if (add != bddfalse
                && bdd_exist(add, all_acceptance_conditions_) == bddtrue)
              {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
985
986
		assert(src_right != dst_right);

987
988
                constraint.emplace_back(new_original_[src_right],
					new_original_[dst_right],
989
					add);
Thomas Badie's avatar
Thomas Badie committed
990
991
992
993
994
995
996
997
998
999
              }
          }
        else if (out_scc_left && !out_scc_right)
          {
            bdd b = bdd_exist(left, notap);
            bdd add = bdd_exist(right & b, bdd_support(b));

            if (add != bddfalse
                && bdd_exist(add, all_acceptance_conditions_) == bddtrue)
              {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1000
1001
		assert(src_left != dst_left);

1002
1003
                constraint.emplace_back(new_original_[src_left],
					new_original_[dst_left],
1004
					add);
Thomas Badie's avatar
Thomas Badie committed
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
              }
          }
        else if (out_scc_left && out_scc_right)
          {
            bdd b = bdd_exist(left, notap);
            bdd add = bdd_exist(right & b, bdd_support(b));

            if (add != bddfalse
                && bdd_exist(add, all_acceptance_conditions_) == bddtrue)
              {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1015
		assert(src_left != dst_left && src_right != dst_right);
Thomas Badie's avatar
Thomas Badie committed
1016
		// FIXME: cas pas compris.
1017
1018
                constraint.emplace_back(new_original_[src_left],
					new_original_[dst_left],
1019
					add);
1020
1021
		constraint.emplace_back(new_original_[src_right],
					new_original_[dst_right],
1022
					add);
Thomas Badie's avatar
Thomas Badie committed
1023
1024
1025
1026
              }

          }
        else
1027
          SPOT_UNREACHABLE();
Thomas Badie's avatar
Thomas Badie committed
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
      }


      // This function run over the signatures, and select the
      // transitions that are out of a SCC and call the function
      // create_simple_constraint to solve the problem.

      // NOTE: Currently, this may not be the most accurate method,
      // because we check for equality in the destination part of the
      // signature. We may just check the destination that can be
      // implied instead.
1039
1040
1041
      std::list<constraint> create_new_constraint(unsigned left,
                                                  unsigned right,
                                                  vector_state_bdd& state2sig)
Thomas Badie's avatar
Thomas Badie committed
1042
      {
1043
1044
	bdd pcl = previous_class_[left];
	bdd pcr = previous_class_[right];
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1045

Thomas Badie's avatar
Thomas Badie committed
1046
1047
1048
1049
1050
        bdd sigl = state2sig[left];
        bdd sigr = state2sig[right];

        std::list<constraint> res;

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1051
1052
1053
1054
1055
1056
	bdd ex = all_class_var_ & on_cycle_;

	bdd both = pcl & pcr;
	int lc = bdd_var(pcl);
#define DEST(x) bdd_compose(bdd_existcomp(x, ex), both, lc)

Thomas Badie's avatar
Thomas Badie committed
1057
1058
        // Key is destination class, value is the signature part that
        // led to this destination class.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
	map_bdd_bdd sigl_map;
	{
	  minato_isop isop(sigl & on_cycle_);
	  bdd cond_acc_dest;
	  while ((cond_acc_dest = isop.next()) != bddfalse)
	    sigl_map[DEST(cond_acc_dest)]
	      |= cond_acc_dest;
	}
	{
	  minato_isop isop(sigl & !on_cycle_);
	  bdd cond_acc_dest;
	  while ((cond_acc_dest = isop.next()) != bddfalse)
	    sigl_map[DEST(cond_acc_dest)]
	      |= cond_acc_dest;
	}
Thomas Badie's avatar
Thomas Badie committed
1074
        map_bdd_bdd sigr_map;
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
	{
	  minato_isop isop2(sigr & on_cycle_);
	  bdd cond_acc_dest2;
	  while ((cond_acc_dest2 = isop2.next()) != bddfalse)
	    sigr_map[DEST(cond_acc_dest2)]
	      |= cond_acc_dest2;
	}
	{
	  minato_isop isop2(sigr & !on_cycle_);
	  bdd cond_acc_dest2;
	  while ((cond_acc_dest2 = isop2.next()) != bddfalse)
	    sigr_map[DEST(cond_acc_dest2)]
	      |= cond_acc_dest2;
	}
Thomas Badie's avatar
Thomas Badie committed
1089
1090

        // Iterate over the transitions of both states.
1091
1092
1093
1094
1095
1096
1097
1098
1099
        for (auto lp: sigl_map)
	  for (auto rp: sigr_map)
	    // And create constraints if any of the transitions
	    // is out of the SCC and the left could imply the right.
	    if ((is_out_scc(lp.second) || is_out_scc(rp.second))
		&& (bdd_exist(lp.first, on_cycle_) ==
		    bdd_exist(rp.first, on_cycle_)))
	      create_simple_constraint(lp.second, rp.second,
				       left, right, res);
Thomas Badie's avatar
Thomas Badie committed
1100
1101
1102
1103
1104
1105
1106
1107
        return res;
      }

      inline automaton_size get_stat() const
      {
        return min_size_;
      }

1108
      tgba_digraph* run()
Thomas Badie's avatar
Thomas Badie committed
1109
1110
1111
1112
1113
1114
1115
1116
1117
      {
        // Iterate the simulation until the end. We just don't return
        // an automaton. This allows us to get all the information
        // about the states and their signature.
        main_loop();

        // Compute the don't care signatures,
        map_bdd_lstate dont_care_bdd_lstate;
        // Useful to keep track of who is who.
1118
1119
        vector_state_bdd dont_care_state2sig(size_a_);
        vector_state_bdd state2sig(size_a_);
Thomas Badie's avatar
Thomas Badie committed
1120
1121
1122

        list_bdd_bdd dont_care_now_to_now;
        map_bdd_state class2state;
1123
1124
1125
        list_bdd_bdd now_to_now;
        bdd_lstate_.clear();

Thomas Badie's avatar
Thomas Badie committed
1126
        // Compute the don't care signature for all the states.
1127
	for (unsigned s = 0; s < size_a_; ++s)
Thomas Badie's avatar
Thomas Badie committed
1128
          {
1129
	    bdd clas = previous_class_[s];
1130
1131
            bdd sig = dont_care_compute_sig(s);
            dont_care_bdd_lstate[sig].push_back(s);
1132
            dont_care_state2sig[s] = sig;
1133
            dont_care_now_to_now.emplace_back(sig, clas);
1134
            class2state[clas] = s;
Thomas Badie's avatar
Thomas Badie committed
1135

1136
1137
            sig = compute_sig(s);
            bdd_lstate_[sig].push_back(s);
1138
            state2sig[s] = sig;
1139
            now_to_now.push_back(std::make_pair(sig, clas));
Thomas Badie's avatar
Thomas Badie committed
1140
1141
1142
1143
1144
1145
1146
1147
1148
          }

        map_bdd_bdd dont_care_relation;
        map_bdd_bdd relation;
        update_po(now_to_now, relation);
        dont_care_update_po(dont_care_now_to_now, dont_care_relation);

        constraint_list cc;

1149
1150
        for (auto p: relation)
	  revert_relation_[p.second] = class2state[p.first];
Thomas Badie's avatar
Thomas Badie committed
1151
1152
1153
1154
1155

        int number_constraints = 0;
        relation_ = relation;


1156
1157
1158
        // make the diff between the two tables: imply and
        // could_imply.
	for (unsigned s = 0; s < size_a_; ++s)
Thomas Badie's avatar
Thomas Badie committed
1159
          {
1160
1161
1162
            bdd clas = previous_class_[s];
            assert(relation.find(clas) != relation.end());
            assert(dont_care_relation.find(clas) != dont_care_relation.end());
Thomas Badie's avatar
Thomas Badie committed
1163

1164
1165
            bdd care_rel = relation[clas];
            bdd dont_care_rel = dont_care_relation[clas];
Thomas Badie's avatar
Thomas Badie committed
1166
1167
1168
1169

            if (care_rel == dont_care_rel)
              continue;

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1170
1171
            // If they are different we necessarily have
	    // dont_care_rel == care_rel & diff
Thomas Badie's avatar
Thomas Badie committed
1172
            bdd diff = bdd_exist(dont_care_rel, care_rel);
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1173
1174
	    assert(dont_care_rel == (care_rel & diff));
	    assert(diff != bddtrue);
Thomas Badie's avatar
Thomas Badie committed
1175

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1176
	    do
Thomas Badie's avatar
Thomas Badie committed
1177
              {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1178
                bdd cur_diff = bdd_ithvar(bdd_var(diff));
1179
                cc[clas][cur_diff]
1180
                  = create_new_constraint(s,
Thomas Badie's avatar
Thomas Badie committed
1181
1182
1183
                                          class2state[cur_diff],
                                          dont_care_state2sig);
                ++number_constraints;
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1184
                diff = bdd_high(diff);
Thomas Badie's avatar
Thomas Badie committed
1185
              }
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1186
	    while (diff != bddtrue);
Thomas Badie's avatar
Thomas Badie committed
1187
1188
          }
#ifndef NDEBUG
1189
1190
	for (auto& i: class2state)
	  assert(previous_class_[i.second] == i.first);
Thomas Badie's avatar
Thomas Badie committed
1191
1192
#endif

1193
        tgba_digraph* min = 0;
Thomas Badie's avatar
Thomas Badie committed
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251

        map_constraint cstr;

        if (has_limit_)
          rec(cc, cstr, &min, limit_);
        else
          rec(cc, cstr, &min);

        return min;
      }

#define ERASE(inner_map, bigger_map, it)        \
      inner_map.erase(it);                      \
      if (inner_map.empty())                    \
        bigger_map.erase(bigger_map.begin())

      // Add and erase.
      void add_to_map_imply(constraint_list& constraints,
                            map_constraint& cstr)
      {
        constraint_list::iterator it = constraints.begin();
        std::map<bdd,
                 std::list<constraint>,
                 bdd_less_than>::iterator it2 = it->second.begin();

        add_to_map(it2->second, cstr);

        bdd implied_list = relation_[it2->first]; // it2->first:
                                                  // destination class.

        ERASE(it->second, constraints, it2);
        if (constraints.empty())
          return;
        it = constraints.begin();
        // At worst, implied_list is equal to it2->first.
        while (implied_list != bddtrue)
          {
            bdd cur_implied = bdd_ithvar(bdd_var(implied_list));

            std::map<bdd,
                     std::list<constraint>,
                     bdd_less_than>::iterator tmp
              = it->second.find(cur_implied);
            if (tmp != it->second.end())
              {
                add_to_map(tmp->second, cstr);
                ERASE(it->second, constraints, tmp);
                if (constraints.empty())
                  return;
              }

            implied_list = bdd_high(implied_list);
          }
      }

      // Compute recursively all the combinations.
      void rec(constraint_list constraints,
               map_constraint cstr,
1252
               tgba_digraph** min,
Thomas Badie's avatar
Thomas Badie committed
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
               int max_depth = std::numeric_limits<int>::max())
      {
        assert(max_depth > 0);
        while (!constraints.empty())
          {
            if (!--max_depth)
                break;
            add_to_map_imply(constraints, cstr);
            rec(constraints, cstr, min, max_depth);
          }

        if (empty_seen_ && cstr.empty())
          return;
        else if (cstr.empty())
          empty_seen_ = true;

1269
        direct_simulation<false, false> dir_sim(original_, &cstr);
1270
        tgba_digraph* tmp = dir_sim.run();
Thomas Badie's avatar
Thomas Badie committed
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
        automaton_size cur_size = dir_sim.get_stat();
        if (*min == 0 || min_size_ > cur_size)
          {
            delete *min;
            *min = tmp;
            min_size_ = cur_size;
            res_is_deterministic = dir_sim.result_is_deterministic();
          }
        else
          {
            delete tmp;
          }
      }

      void set_limit(int n)
      {
        has_limit_ = true;
        limit_ = n;
      }

    private:
      // This bdd is used to differentiate parts of the signature that
      // are in a SCC and those that are not.
      bdd on_cycle_;

      map_bdd_bdd dont_care_relation_;

      map_bdd_state revert_relation_;

      automaton_size min_size_;

      bool empty_seen_;

      bool has_limit_;
      int limit_;

      bdd notap;