simulation.cc 42.2 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
26
#include "tgba/tgbaexplicit.hh"
#include "simulation.hh"
27
#include "priv/acccompl.hh"
Thomas Badie's avatar
Thomas Badie committed
28
29
30
#include "misc/minato.hh"
#include "tgba/bddprint.hh"
#include "tgbaalgos/reachiter.hh"
31
#include "tgbaalgos/sccfilter.hh"
Thomas Badie's avatar
Thomas Badie committed
32
33
#include "tgbaalgos/scc.hh"
#include "tgbaalgos/dupexp.hh"
Thomas Badie's avatar
Thomas Badie committed
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
65

// 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'.
66
// 3. Rename the class (to actualize the name in the previous_class and
Thomas Badie's avatar
Thomas Badie committed
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
//    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
84
85
86
87
// 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
88
89
90
91
92
93
94
namespace spot
{
  namespace
  {
    // Some useful typedef:

    // Used to get the signature of the state.
95
    typedef std::vector<bdd> vector_state_bdd;
Thomas Badie's avatar
Thomas Badie committed
96

97
98
    typedef std::vector<const state*> vector_state_state;

Thomas Badie's avatar
Thomas Badie committed
99

Thomas Badie's avatar
Thomas Badie committed
100
    // Get the list of state for each class.
101
    typedef std::map<bdd, std::list<unsigned>,
Thomas Badie's avatar
Thomas Badie committed
102
103
                     bdd_less_than> map_bdd_lstate;

104
    typedef std::map<bdd, unsigned, bdd_less_than> map_bdd_state;
Thomas Badie's avatar
Thomas Badie committed
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
135

    // 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;

136
    typedef std::tuple<const state*, const state*, bdd> constraint;
Thomas Badie's avatar
Thomas Badie committed
137
138
139
140
141
142

    // 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)
    {
143
      for (auto& p: list)
144
145
146
	feed_me.insert(std::make_pair(std::make_pair(std::get<0>(p),
						     std::get<1>(p)),
				      std::get<2>(p)));
Thomas Badie's avatar
Thomas Badie committed
147
148
149
150
151
    }


    // This class helps to compare two automata in term of
    // size.
152
153
154
155
156
157
158
159
    struct automaton_size
    {
      automaton_size()
        : transitions(0),
          states(0)
      {
      }

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
160
      inline bool operator!=(const automaton_size& r)
161
162
163
164
      {
        return transitions != r.transitions || states != r.states;
      }

Thomas Badie's avatar
Thomas Badie committed
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
194
      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;
      }

195
196
197
      int transitions;
      int states;
    };
Thomas Badie's avatar
Thomas Badie committed
198

Thomas Badie's avatar
Thomas Badie committed
199
    // The direct_simulation. If Cosimulation is true, we are doing a
200
201
    // cosimulation.
    template <bool Cosimulation, bool Sba>
202
    class direct_simulation
Thomas Badie's avatar
Thomas Badie committed
203
    {
Thomas Badie's avatar
Thomas Badie committed
204
    protected:
205
206
207
      // 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
208
209
210
211
212
      direct_simulation(const tgba* t, const map_constraint* map_cst = 0)
        : a_(0),
          po_size_(0),
          all_class_var_(bddtrue),
          map_cst_(map_cst),
213
          original_(t)
214
      {
Thomas Badie's avatar
Thomas Badie committed
215
216
217
218
219
220
221
222
223
224
        // 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_;

225

226
227
	acc_compl ac(a_->all_acceptance_conditions(),
		     a_->neg_acceptance_conditions());
228

229
230
231
232
233
234
235
236
237
238
	// 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_);
	    }
239
	  unsigned ns = old_a_->num_states();
240
	  if (Cosimulation)
241
	    a_->new_states(ns);
242
243
	  for (unsigned s = 0; s < ns; ++s)
	    {
244
	      for (auto& t: old_a_->out(s))
245
246
247
248
249
250
251
252
253
254
255
		{
		  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;
256
		      for (auto& td: old_a_->out(t.dst))
257
258
259
260
261
262
263
264
265
266
			{
			  acc = ac.complement(td.acc);
			  break;
			}
		    }
		  else
		    {
		      acc = ac.complement(t.acc);
		    }
		  if (Cosimulation)
267
		    a_->new_transition(t.dst, s, t.cond, acc);
268
269
270
271
272
273
		  else
		    t.acc = acc;
		}
	    }
	  size_a_ = ns;
	}
274
275
276
277
278

	// 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()
279
	  ->register_anonymous_variables(size_a_ + 1, this);
280

281
282
        all_acceptance_conditions_ = a_->all_acceptance_conditions();
        all_proms_ = bdd_support(all_acceptance_conditions_);
Thomas Badie's avatar
Thomas Badie committed
283

Thomas Badie's avatar
Thomas Badie committed
284
285
        bdd_initial = bdd_ithvar(set_num++);
	bdd init = bdd_ithvar(set_num++);
286
287
288

	used_var_.push_back(init);

289
290
291
292
	// 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
293

294
295
296
297
	// 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.
298
	all_class_var_ = init;
299
	for (unsigned i = set_num; i < set_num + size_a_ - 1; ++i)
Thomas Badie's avatar
Thomas Badie committed
300
301
302
303
304
          {
            free_var_.push(i);
            all_class_var_ &= bdd_ithvar(i);
          }

305
306
	relation_[init] = init;
      }
Thomas Badie's avatar
Thomas Badie committed
307
308


309
310
311
      // 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
312
      virtual ~direct_simulation()
313
      {
314
	a_->get_dict()->unregister_all_my_variables(this);
Thomas Badie's avatar
Thomas Badie committed
315
        delete scc_map_;
316

317
	delete old_a_;
318
        // a_ is a new automaton only if we are doing a cosimulation.
Thomas Badie's avatar
Thomas Badie committed
319
320
        if (Cosimulation)
          delete a_;
321
      }
Thomas Badie's avatar
Thomas Badie committed
322

323
      // Update the name of the classes.
324
325
326
327
328
329
      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.
330
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
331
          {
332
333
334
335
336
337
338
339
	    // 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)
340
		previous_class_[s] = bddfalse;
341
342
	    else
	      for (auto s: p.second)
343
		previous_class_[s] = *it_bdd;
344
	    ++it_bdd;
Thomas Badie's avatar
Thomas Badie committed
345
          }
346
347
      }

Thomas Badie's avatar
Thomas Badie committed
348
      void main_loop()
349
350
351
352
353
      {
	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
354
          {
355
            update_previous_class();
Thomas Badie's avatar
Thomas Badie committed
356
357
358
359
360
361
362
363
            nb_partition_before = bdd_lstate_.size();
            bdd_lstate_.clear();
            nb_po_before = po_size_;
            po_size_ = 0;
            update_sig();
            go_to_next_it();
          }

364
	update_previous_class();
Thomas Badie's avatar
Thomas Badie committed
365
366
367
      }

      // The core loop of the algorithm.
368
      tgba_digraph* run()
Thomas Badie's avatar
Thomas Badie committed
369
370
      {
        main_loop();
371
372
	return build_result();
      }
Thomas Badie's avatar
Thomas Badie committed
373

374
      // Take a state and compute its signature.
375
      bdd compute_sig(unsigned src)
376
      {
Thomas Badie's avatar
Thomas Badie committed
377
        bdd res = bddfalse;
Thomas Badie's avatar
Thomas Badie committed
378

379
        for (auto& t: a_->out(src))
Thomas Badie's avatar
Thomas Badie committed
380
          {
Thomas Badie's avatar
Thomas Badie committed
381
            bdd acc = bddtrue;
Thomas Badie's avatar
Thomas Badie committed
382

383
	    map_constraint::const_iterator it;
384
385
	    // Check if we have a constraint about this edge in the
	    // original automaton.
386
387
	    if (map_cst_
		&& ((it = map_cst_
388
389
		     ->find(std::make_pair(new_original_[src],
					   new_original_[t.dst])))
390
391
392
393
394
395
		    != map_cst_->end()))
	      {
		acc = it->second;
	      }
	    else
	      {
396
		acc = t.acc;
397
398
399
400
401
	      }

	    // 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.
402
	    bdd to_add = acc & t.cond & relation_[previous_class_[t.dst]];
Thomas Badie's avatar
Thomas Badie committed
403

404
405
	    res |= to_add;
	  }
Thomas Badie's avatar
Thomas Badie committed
406

Thomas Badie's avatar
Thomas Badie committed
407
        // When we Cosimulate, we add a special flag to differentiate
408
        // the initial state from the other.
409
        if (Cosimulation && src == 0)
Thomas Badie's avatar
Thomas Badie committed
410
411
412
          res |= bdd_initial;

        return res;
413
414
      }

Thomas Badie's avatar
Thomas Badie committed
415

416
417
      void update_sig()
      {
418
	for (unsigned s = 0; s < size_a_; ++s)
419
	  bdd_lstate_[compute_sig(s)].push_back(s);
420
      }
Thomas Badie's avatar
Thomas Badie committed
421
422


423
424
425
426
      // 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
427

Thomas Badie's avatar
Thomas Badie committed
428
429
430

        // If we have created more partitions, we need to use more
        // variables.
431
	for (int i = 0; i < nb_new_color; ++i)
Thomas Badie's avatar
Thomas Badie committed
432
433
434
435
436
437
          {
            assert(!free_var_.empty());
            used_var_.push_back(bdd_ithvar(free_var_.front()));
            free_var_.pop();
          }

Thomas Badie's avatar
Thomas Badie committed
438
439
440

        // If we have reduced the number of partition, we 'free' them
        // in the free_var_ list.
441
442
443
444
445
446
447
448
449
450
451
	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
452

453
454
455
456
457
458
459
	// 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
460

461
	std::list<bdd>::iterator it_bdd = used_var_.begin();
Thomas Badie's avatar
Thomas Badie committed
462

463
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
464
          {
465
466
467
468
469
470
	    // 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.
471
472
473
474
	    bdd acc = bddfalse;
	    if (p.first != bddfalse)
	      acc = *it_bdd;
	    now_to_next[p.first] = acc;
475
	    ++it_bdd;
Thomas Badie's avatar
Thomas Badie committed
476
477
          }

Thomas Badie's avatar
Thomas Badie committed
478
	update_po(now_to_next, relation_);
479
480
      }

Thomas Badie's avatar
Thomas Badie committed
481
482
483
484
485
486
487
488
489
      // 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)
490
491
492
493
494
495
496
497
      {
	// 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
498
499
	for (typename container_bdd_bdd::const_iterator it1
               = now_to_next.begin();
500
501
	     it1 != now_to_next.end();
	     ++it1)
Thomas Badie's avatar
Thomas Badie committed
502
503
          {
            bdd accu = it1->second;
Thomas Badie's avatar
Thomas Badie committed
504
505
            for (typename container_bdd_bdd::const_iterator it2
                   = now_to_next.begin();
Thomas Badie's avatar
Thomas Badie committed
506
507
                 it2 != now_to_next.end();
                 ++it2)
Thomas Badie's avatar
Thomas Badie committed
508
509
510
511
512
513
514
515
516
517
518
              {
                // 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
519
            relation[it1->second] = accu;
Thomas Badie's avatar
Thomas Badie committed
520
          }
521
522
      }

523
524
525
526
527
528
529
      automaton_size get_stat() const
      {
        assert(stat.states != 0);

        return stat;
      }

Thomas Badie's avatar
Thomas Badie committed
530
531
532
533
534
535
536
537
      bool result_is_deterministic() const
      {
        assert(stat.states != 0);

        return res_is_deterministic;
      }


538

539
      // Build the minimal resulting automaton.
540
      tgba_digraph* build_result()
541
542
543
544
545
546
      {
	// 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
547
	acc_compl reverser(all_acceptance_conditions_,
548
549
			   a_->neg_acceptance_conditions());

550
	bdd_dict* d = a_->get_dict();
551
	tgba_digraph* res = new tgba_digraph(d);
552
553
	d->register_all_variables_of(a_, res);
	res->set_acceptance_conditions(all_acceptance_conditions_);
554

Thomas Badie's avatar
Thomas Badie committed
555
	bdd sup_all_acc = bdd_support(all_acceptance_conditions_);
556
557
558
	// Non atomic propositions variables (= acc and class)
	bdd nonapvars = sup_all_acc & bdd_support(all_class_var_);

559
560
	auto* gb = res->create_namer<int>();

561
	// Create one state per partition.
562
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
563
          {
564
565
566
567
568
            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
569
570
          }

571
572
573
	// Acceptance of states.  Only used if Sba && Cosimulation.
	std::vector<bdd> accst;
	if (Sba && Cosimulation)
574
	  accst.resize(res->num_states(), bddfalse);
575

576
577
578
        stat.states = bdd_lstate_.size();
        stat.transitions = 0;

Thomas Badie's avatar
Thomas Badie committed
579
580
581
        unsigned nb_satoneset = 0;
        unsigned nb_minato = 0;

582
	// For each class, we will create
583
	// all the transitions between the states.
584
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
585
          {
586
587
588
589
590
	    // 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.
591
            bdd sig = compute_sig(p.second.front());
Thomas Badie's avatar
Thomas Badie committed
592

Thomas Badie's avatar
Thomas Badie committed
593
594
595
            if (Cosimulation)
              sig = bdd_compose(sig, bddfalse, bdd_var(bdd_initial));

Thomas Badie's avatar
Thomas Badie committed
596
597
598
599
600
601
602
603
604
605
606
607
608
            // 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)
609
610
611
612
613
614
	      {
		bdd one = bdd_satoneset(all_atomic_prop,
					sup_all_atomic_prop,
					bddtrue);
		all_atomic_prop -= one;

615
		// For each possible valuation, iterate over all possible
616
617
618
619
620
621
622
623
624
		// 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
625
626
                ++nb_satoneset;

627
628
629
		bdd cond_acc_dest;
		while ((cond_acc_dest = isop.next()) != bddfalse)
		  {
630
631
                    ++stat.transitions;

Thomas Badie's avatar
Thomas Badie committed
632
633
                    ++nb_minato;

634
635
		    // Take the transition, and keep only the variable which
		    // are used to represent the class.
636
		    bdd dst = bdd_existcomp(cond_acc_dest,
637
638
639
640
641
					     all_class_var_);

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

642
		    // Keep the other!
643
644
645
646
		    bdd cond = bdd_existcomp(cond_acc_dest,
					     sup_all_atomic_prop);

		    // Because we have complemented all the acceptance
647
648
		    // conditions on the input automaton, we must
		    // revert them to create a new transition.
649
650
		    acc = reverser.reverse_complement(acc);

651
652
653
		    if (Cosimulation)
		      {
			if (Sba)
654
655
656
657
658
659
660
661
662
663
			  {
			    // 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);
664
		      }
665
		    else
666
667
668
		      {
			gb->new_transition(src.id(), dst.id(), cond, acc);
		      }
669
670
		  }
	      }
Thomas Badie's avatar
Thomas Badie committed
671
672
          }

673
674
	res->set_init_state(gb->get_state(previous_class_
					  [a_->get_init_state_number()].id()));
Thomas Badie's avatar
Thomas Badie committed
675

676
	res->merge_transitions(); // FIXME: is this really needed?
Thomas Badie's avatar
Thomas Badie committed
677

678
679
680
	// Mark all accepting state in a second pass, when
	// dealing with SBA in cosimulation.
	if (Sba && Cosimulation)
681
682
683
684
685
686
687
	  {
	    unsigned ns = res->num_states();
	    for (unsigned s = 0; s < ns; ++s)
	      {
		bdd acc = accst[s];
		if (acc == bddfalse)
		  continue;
688
		for (auto& t: res->out(s))
689
690
691
		  t.acc = acc;
	      }
	  }
692

693
	delete gb;
Thomas Badie's avatar
Thomas Badie committed
694
695
        res_is_deterministic = nb_minato == nb_satoneset;

696
697
698
699
700
701
702
703
704
705
706
	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()
      {
707
	for (auto& p: bdd_lstate_)
Thomas Badie's avatar
Thomas Badie committed
708
709
          {
            std::cerr << "partition: "
710
                      << bdd_format_isop(a_->get_dict(), p.first)
Thomas Badie's avatar
Thomas Badie committed
711
                      << std::endl;
712
            for (auto s: p.second)
713
714
715
	      std::cerr << "  - "
			<< a_->format_state(a_->state_from_number(s))
			<< '\n';
Thomas Badie's avatar
Thomas Badie committed
716
717
          }

718
	std::cerr << "\nPrevious iteration\n" << std::endl;
Thomas Badie's avatar
Thomas Badie committed
719

720
721
	unsigned ps = previous_class_.size();
	for (unsigned p = 0; p < ps; ++p)
Thomas Badie's avatar
Thomas Badie committed
722
          {
723
            std::cerr << a_->format_state(a_->state_from_number(p))
Thomas Badie's avatar
Thomas Badie committed
724
                      << " was in "
725
                      << bdd_format_set(a_->get_dict(), previous_class_[p])
726
                      << '\n';
Thomas Badie's avatar
Thomas Badie committed
727
          }
728
      }
Thomas Badie's avatar
Thomas Badie committed
729

Thomas Badie's avatar
Thomas Badie committed
730
    protected:
731
      // The automaton which is simulated.
732
733
      tgba_digraph* a_;
      tgba_digraph* old_a_;
Thomas Badie's avatar
Thomas Badie committed
734

735
736
737
738
739
740
741
      // 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
742

743
      // Represent the class of each state at the previous iteration.
744
      vector_state_bdd previous_class_;
Thomas Badie's avatar
Thomas Badie committed
745

746
747
748
      // 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
749

750
751
752
      // 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
753

754
755
      // 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
756

757
758
      // Size of the automaton.
      unsigned int size_a_;
Thomas Badie's avatar
Thomas Badie committed
759

760
761
762
      // 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
763

764
765
      // All the class variable:
      bdd all_class_var_;
Thomas Badie's avatar
Thomas Badie committed
766
767
768
769

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

Thomas Badie's avatar
Thomas Badie committed
770
771
      bdd all_proms_;

772
      automaton_size stat;
773

Thomas Badie's avatar
Thomas Badie committed
774
      scc_map* scc_map_;
775
      std::vector<const state*> new_original_;
Thomas Badie's avatar
Thomas Badie committed
776
777
778
779
780
781
782
783
784
785
786

      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.
787
    class direct_simulation_dont_care: public direct_simulation<false, false>
Thomas Badie's avatar
Thomas Badie committed
788
789
790
791
792
793
794
795
796
797
798
799
    {
      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)
800
      : direct_simulation<false, false>(t)
Thomas Badie's avatar
Thomas Badie committed
801
802
803
      {
        // This variable is used in the new signature.
        on_cycle_ =
804
          bdd_ithvar(a_->get_dict()->register_anonymous_variables(1, this));
Thomas Badie's avatar
Thomas Badie committed
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823

        // 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.
824
      bdd dont_care_compute_sig(unsigned src)
Thomas Badie's avatar
Thomas Badie committed
825
826
827
      {
        bdd res = bddfalse;

828
        unsigned scc = scc_map_->scc_of_state(old_a_->state_from_number(src));
Thomas Badie's avatar
Thomas Badie committed
829
830
        bool sccacc = scc_map_->accepting(scc);

831
	for (auto& t: a_->out(src))
Thomas Badie's avatar
Thomas Badie committed
832
          {
833
            bdd cl = previous_class_[t.dst];
Thomas Badie's avatar
Thomas Badie committed
834
835
            bdd acc;

836
            if (scc != scc_map_->scc_of_state(old_a_->state_from_number(t.dst)))
Thomas Badie's avatar
Thomas Badie committed
837
838
              acc = !on_cycle_;
            else if (sccacc)
839
              acc = on_cycle_ & t.acc;
Thomas Badie's avatar
Thomas Badie committed
840
841
842
            else
              acc = on_cycle_ & all_proms_;

843
            bdd to_add = acc & t.cond & relation_[cl];
Thomas Badie's avatar
Thomas Badie committed
844
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
            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
891
892
893
894
895
	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
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
	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
916
917
918
919
920
	    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
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944

            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
945
946
	return bddfalse !=  bdd_relprod(b, !on_cycle_, on_cycle_);
        // return bddfalse != bdd_restrict(b, !on_cycle_);
Thomas Badie's avatar
Thomas Badie committed
947
948
949
950
951
952
953
954
955
956
      }

      // 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,
957
958
                                    unsigned src_left,
                                    unsigned src_right,
Thomas Badie's avatar
Thomas Badie committed
959
960
                                    std::list<constraint>& constraint)
      {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
961
	assert(src_left != src_right);
Thomas Badie's avatar
Thomas Badie committed
962
963
964
965
966
        // 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());
967
        unsigned dst_left = revert_relation_[dest_class];
Thomas Badie's avatar
Thomas Badie committed
968
        dest_class = bdd_existcomp(right, all_class_var_);
969
        unsigned dst_right = revert_relation_[dest_class];
Thomas Badie's avatar
Thomas Badie committed
970

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
971
972
	assert(src_left != dst_left || src_right != dst_right);

Thomas Badie's avatar
Thomas Badie committed
973
974
975
976
977
978
979
980
981
982
983
        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
984
985
		assert(src_right != dst_right);

986
987
                constraint.emplace_back(new_original_[src_right],
					new_original_[dst_right],
988
					add);
Thomas Badie's avatar
Thomas Badie committed
989
990
991
992
993
994
995
996
997
998
              }
          }
        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
999
1000
		assert(src_left != dst_left);

1001
1002
                constraint.emplace_back(new_original_[src_left],
					new_original_[dst_left],
1003
					add);
Thomas Badie's avatar
Thomas Badie committed
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
              }
          }
        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
1014
		assert(src_left != dst_left && src_right != dst_right);
Thomas Badie's avatar
Thomas Badie committed
1015
		// FIXME: cas pas compris.
1016
1017
                constraint.emplace_back(new_original_[src_left],
					new_original_[dst_left],
1018
					add);
1019
1020
		constraint.emplace_back(new_original_[src_right],
					new_original_[dst_right],
1021
					add);
Thomas Badie's avatar
Thomas Badie committed
1022
1023
1024
1025
              }

          }
        else
1026
          SPOT_UNREACHABLE();
Thomas Badie's avatar
Thomas Badie committed
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
      }


      // 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.
1038
1039
1040
      std::list<constraint> create_new_constraint(unsigned left,
                                                  unsigned right,
                                                  vector_state_bdd& state2sig)
Thomas Badie's avatar
Thomas Badie committed
1041
      {
1042
1043
	bdd pcl = previous_class_[left];
	bdd pcr = previous_class_[right];
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1044

Thomas Badie's avatar
Thomas Badie committed
1045
1046
1047
1048
1049
        bdd sigl = state2sig[left];
        bdd sigr = state2sig[right];

        std::list<constraint> res;

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1050
1051
1052
1053
1054
1055
	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
1056
1057
        // Key is destination class, value is the signature part that
        // led to this destination class.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
	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
1073
        map_bdd_bdd sigr_map;
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
	{
	  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
1088
1089

        // Iterate over the transitions of both states.
1090
1091
1092
1093
1094
1095
1096
1097
1098
        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
1099
1100
1101
1102
1103
1104
1105
1106
        return res;
      }

      inline automaton_size get_stat() const
      {
        return min_size_;
      }

1107
      tgba_digraph* run()
Thomas Badie's avatar
Thomas Badie committed
1108
1109
1110
1111
1112
1113
1114
1115
1116
      {
        // 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.
1117
1118
        vector_state_bdd dont_care_state2sig(size_a_);
        vector_state_bdd state2sig(size_a_);
Thomas Badie's avatar
Thomas Badie committed
1119
1120
1121

        list_bdd_bdd dont_care_now_to_now;
        map_bdd_state class2state;
1122
1123
1124
        list_bdd_bdd now_to_now;
        bdd_lstate_.clear();

Thomas Badie's avatar
Thomas Badie committed
1125
        // Compute the don't care signature for all the states.
1126
	for (unsigned s = 0; s < size_a_; ++s)
Thomas Badie's avatar
Thomas Badie committed
1127
          {
1128
	    bdd clas = previous_class_[s];
1129
1130
            bdd sig = dont_care_compute_sig(s);
            dont_care_bdd_lstate[sig].push_back(s);
1131
            dont_care_state2sig[s] = sig;
1132
            dont_care_now_to_now.emplace_back(sig, clas);
1133
            class2state[clas] = s;
Thomas Badie's avatar
Thomas Badie committed
1134

1135
1136
            sig = compute_sig(s);
            bdd_lstate_[sig].push_back(s);
1137
            state2sig[s] = sig;
1138
            now_to_now.push_back(std::make_pair(sig, clas));
Thomas Badie's avatar
Thomas Badie committed
1139
1140
1141
1142
1143
1144
1145
1146
1147
          }

        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;

1148
1149
        for (auto p: relation)
	  revert_relation_[p.second] = class2state[p.first];
Thomas Badie's avatar
Thomas Badie committed
1150
1151
1152
1153
1154

        int number_constraints = 0;
        relation_ = relation;


1155
1156
1157
        // 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
1158
          {
1159
1160
1161
            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
1162

1163
1164
            bdd care_rel = relation[clas];
            bdd dont_care_rel = dont_care_relation[clas];
Thomas Badie's avatar
Thomas Badie committed
1165
1166
1167
1168

            if (care_rel == dont_care_rel)
              continue;

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1169
1170
            // If they are different we necessarily have
	    // dont_care_rel == care_rel & diff
Thomas Badie's avatar
Thomas Badie committed
1171
            bdd diff = bdd_exist(dont_care_rel, care_rel);
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1172
1173
	    assert(dont_care_rel == (care_rel & diff));
	    assert(diff != bddtrue);
Thomas Badie's avatar
Thomas Badie committed
1174

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1175
	    do
Thomas Badie's avatar
Thomas Badie committed
1176
              {
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1177
                bdd cur_diff = bdd_ithvar(bdd_var(diff));
1178
                cc[clas][cur_diff]
1179
                  = create_new_constraint(s,
Thomas Badie's avatar
Thomas Badie committed
1180
1181
1182
                                          class2state[cur_diff],
                                          dont_care_state2sig);
                ++number_constraints;
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1183
                diff = bdd_high(diff);
Thomas Badie's avatar
Thomas Badie committed
1184
              }
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1185
	    while (diff != bddtrue);
Thomas Badie's avatar
Thomas Badie committed
1186
1187
          }
#ifndef NDEBUG
1188
1189
	for (auto& i: class2state)
	  assert(previous_class_[i.second] == i.first);
Thomas Badie's avatar
Thomas Badie committed
1190
1191
#endif

1192
        tgba_digraph* min = 0;
Thomas Badie's avatar
Thomas Badie committed
1193
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

        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,
1251
               tgba_digraph** min,
Thomas Badie's avatar
Thomas Badie committed
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
               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;

1268
        direct_simulation<false, false> dir_sim(original_, &cstr);
1269
        tgba_digraph* tmp = dir_sim.run();
Thomas Badie's avatar
Thomas Badie committed
1270
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
        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;
Thomas Badie's avatar
Thomas Badie committed
1307
    };
Thomas Badie's avatar
Thomas Badie committed
1308