GCC Code Coverage Report
Directory: . Exec Total Coverage
File: src/theory/quantifiers/ematching/candidate_generator.cpp Lines: 175 185 94.6 %
Date: 2021-09-29 Branches: 326 782 41.7 %

Line Exec Source
1
/******************************************************************************
2
 * Top contributors (to current version):
3
 *   Andrew Reynolds, Morgan Deters, Aina Niemetz
4
 *
5
 * This file is part of the cvc5 project.
6
 *
7
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
8
 * in the top-level source directory and their institutional affiliations.
9
 * All rights reserved.  See the file COPYING in the top-level source
10
 * directory for licensing information.
11
 * ****************************************************************************
12
 *
13
 * Implementation of theory uf candidate generator class.
14
 */
15
16
#include "theory/quantifiers/ematching/candidate_generator.h"
17
18
#include "expr/dtype.h"
19
#include "expr/dtype_cons.h"
20
#include "options/quantifiers_options.h"
21
#include "smt/smt_engine.h"
22
#include "smt/smt_engine_scope.h"
23
#include "theory/datatypes/datatypes_rewriter.h"
24
#include "theory/quantifiers/first_order_model.h"
25
#include "theory/quantifiers/quantifiers_state.h"
26
#include "theory/quantifiers/term_database.h"
27
#include "theory/quantifiers/term_registry.h"
28
#include "theory/quantifiers/term_util.h"
29
30
using namespace cvc5::kind;
31
32
namespace cvc5 {
33
namespace theory {
34
namespace quantifiers {
35
namespace inst {
36
37
13277
CandidateGenerator::CandidateGenerator(QuantifiersState& qs, TermRegistry& tr)
38
13277
    : d_qs(qs), d_treg(tr)
39
{
40
13277
}
41
42
994044
bool CandidateGenerator::isLegalCandidate( Node n ){
43
2982132
  return d_treg.getTermDatabase()->isTermActive(n)
44
3976176
         && (!options::cegqi() || !quantifiers::TermUtil::hasInstConstAttr(n));
45
}
46
47
13253
CandidateGeneratorQE::CandidateGeneratorQE(QuantifiersState& qs,
48
                                           TermRegistry& tr,
49
13253
                                           Node pat)
50
    : CandidateGenerator(qs, tr),
51
      d_term_iter(-1),
52
      d_term_iter_limit(0),
53
13253
      d_mode(cand_term_none)
54
{
55
13253
  d_op = d_treg.getTermDatabase()->getMatchOperator(pat);
56
13253
  Assert(!d_op.isNull());
57
13253
}
58
59
144487
void CandidateGeneratorQE::reset(Node eqc) { resetForOperator(eqc, d_op); }
60
61
147079
void CandidateGeneratorQE::resetForOperator(Node eqc, Node op)
62
{
63
147079
  d_term_iter = 0;
64
147079
  d_eqc = eqc;
65
147079
  d_op = op;
66
147079
  d_term_iter_limit = d_treg.getTermDatabase()->getNumGroundTerms(d_op);
67
147079
  if( eqc.isNull() ){
68
38401
    d_mode = cand_term_db;
69
  }else{
70
108678
    if( isExcludedEqc( eqc ) ){
71
      d_mode = cand_term_none;
72
    }else{
73
108678
      eq::EqualityEngine* ee = d_qs.getEqualityEngine();
74
108678
      if( ee->hasTerm( eqc ) ){
75
108678
        TNodeTrie* tat = d_treg.getTermDatabase()->getTermArgTrie(eqc, op);
76
108678
        if( tat ){
77
          //create an equivalence class iterator in eq class eqc
78
97312
          Node rep = ee->getRepresentative( eqc );
79
48656
          d_eqc_iter = eq::EqClassIterator( rep, ee );
80
48656
          d_mode = cand_term_eqc;
81
        }else{
82
60022
          d_mode = cand_term_none;
83
        }
84
      }else{
85
        //the only match is this term itself
86
        d_mode = cand_term_ident;
87
      }
88
    }
89
  }
90
147079
}
91
104129
bool CandidateGeneratorQE::isLegalOpCandidate( Node n ) {
92
104129
  if( n.hasOperator() ){
93
94576
    if( isLegalCandidate( n ) ){
94
73025
      return d_treg.getTermDatabase()->getMatchOperator(n) == d_op;
95
    }
96
  }
97
31104
  return false;
98
}
99
100
960056
Node CandidateGeneratorQE::getNextCandidate(){
101
960056
  return getNextCandidateInternal();
102
}
103
104
965335
Node CandidateGeneratorQE::getNextCandidateInternal()
105
{
106
965335
  if( d_mode==cand_term_db ){
107
826886
    Debug("cand-gen-qe") << "...get next candidate in tbd" << std::endl;
108
    //get next candidate term in the uf term database
109
1024306
    while( d_term_iter<d_term_iter_limit ){
110
997520
      Node n = d_treg.getTermDatabase()->getGroundTerm(d_op, d_term_iter);
111
898810
      d_term_iter++;
112
898810
      if( isLegalCandidate( n ) ){
113
805829
        if (d_treg.getTermDatabase()->hasTermCurrent(n))
114
        {
115
805829
          if( d_exclude_eqc.empty() ){
116
777256
            return n;
117
          }else{
118
34302
            Node r = d_qs.getRepresentative(n);
119
28573
            if( d_exclude_eqc.find( r )==d_exclude_eqc.end() ){
120
22844
              Debug("cand-gen-qe") << "...returning " << n << std::endl;
121
22844
              return n;
122
            }
123
          }
124
        }
125
      }
126
    }
127
138449
  }else if( d_mode==cand_term_eqc ){
128
77452
    Debug("cand-gen-qe") << "...get next candidate in eqc" << std::endl;
129
181618
    while( !d_eqc_iter.isFinished() ){
130
156212
      Node n = *d_eqc_iter;
131
104129
      ++d_eqc_iter;
132
104129
      if( isLegalOpCandidate( n ) ){
133
52046
        Debug("cand-gen-qe") << "...returning " << n << std::endl;
134
52046
        return n;
135
      }
136
    }
137
60997
  }else if( d_mode==cand_term_ident ){
138
975
    Debug("cand-gen-qe") << "...get next candidate identity" << std::endl;
139
975
    if (!d_eqc.isNull())
140
    {
141
680
      Node n = d_eqc;
142
647
      d_eqc = Node::null();
143
647
      if( isLegalOpCandidate( n ) ){
144
614
        return n;
145
      }
146
    }
147
  }
148
112575
  return Node::null();
149
}
150
151
2
CandidateGeneratorQELitDeq::CandidateGeneratorQELitDeq(QuantifiersState& qs,
152
                                                       TermRegistry& tr,
153
2
                                                       Node mpat)
154
2
    : CandidateGenerator(qs, tr), d_match_pattern(mpat)
155
{
156
2
  Assert(d_match_pattern.getKind() == EQUAL);
157
2
  d_match_pattern_type = d_match_pattern[0].getType();
158
2
}
159
160
9
void CandidateGeneratorQELitDeq::reset( Node eqc ){
161
9
  eq::EqualityEngine* ee = d_qs.getEqualityEngine();
162
18
  Node falset = NodeManager::currentNM()->mkConst(false);
163
9
  d_eqc_false = eq::EqClassIterator(falset, ee);
164
9
}
165
166
30
Node CandidateGeneratorQELitDeq::getNextCandidate(){
167
  //get next candidate term in equivalence class
168
45
  while( !d_eqc_false.isFinished() ){
169
41
    Node n = (*d_eqc_false);
170
26
    ++d_eqc_false;
171
26
    if( n.getKind()==d_match_pattern.getKind() ){
172
68
      if (n[0].getType().isComparableTo(d_match_pattern_type)
173
68
          && isLegalCandidate(n))
174
      {
175
        //found an iff or equality, try to match it
176
        //DO_THIS: cache to avoid redundancies?
177
        //DO_THIS: do we need to try the symmetric equality for n?  or will it also exist in the eq class of false?
178
11
        return n;
179
      }
180
    }
181
  }
182
4
  return Node::null();
183
}
184
185
22
CandidateGeneratorQEAll::CandidateGeneratorQEAll(QuantifiersState& qs,
186
                                                 TermRegistry& tr,
187
22
                                                 Node mpat)
188
22
    : CandidateGenerator(qs, tr), d_match_pattern(mpat)
189
{
190
22
  d_match_pattern_type = mpat.getType();
191
22
  Assert(mpat.getKind() == INST_CONSTANT);
192
22
  d_f = quantifiers::TermUtil::getInstConstAttr( mpat );
193
22
  d_index = mpat.getAttribute(InstVarNumAttribute());
194
22
  d_firstTime = false;
195
22
}
196
197
53
void CandidateGeneratorQEAll::reset( Node eqc ) {
198
53
  d_eq = eq::EqClassesIterator(d_qs.getEqualityEngine());
199
53
  d_firstTime = true;
200
53
}
201
202
83
Node CandidateGeneratorQEAll::getNextCandidate() {
203
83
  quantifiers::TermDb* tdb = d_treg.getTermDatabase();
204
1463
  while( !d_eq.isFinished() ){
205
1433
    TNode n = (*d_eq);
206
743
    ++d_eq;
207
743
    if( n.getType().isComparableTo( d_match_pattern_type ) ){
208
53
      TNode nh = tdb->getEligibleTermInEqc(n);
209
53
      if( !nh.isNull() ){
210
53
        if (options::instMaxLevel() != -1)
211
        {
212
          nh = d_treg.getModel()->getInternalRepresentative(nh, d_f, d_index);
213
          //don't consider this if already the instantiation is ineligible
214
          if (!nh.isNull() && !tdb->isTermEligibleForInstantiation(nh, d_f))
215
          {
216
            nh = Node::null();
217
          }
218
        }
219
53
        if( !nh.isNull() ){
220
53
          d_firstTime = false;
221
          //an equivalence class with the same type as the pattern, return it
222
53
          return nh;
223
        }
224
      }
225
    }
226
  }
227
30
  if( d_firstTime ){
228
    //must return something
229
6
    d_firstTime = false;
230
6
    return d_treg.getTermForType(d_match_pattern_type);
231
  }
232
24
  return Node::null();
233
}
234
235
993
CandidateGeneratorConsExpand::CandidateGeneratorConsExpand(QuantifiersState& qs,
236
                                                           TermRegistry& tr,
237
993
                                                           Node mpat)
238
993
    : CandidateGeneratorQE(qs, tr, mpat)
239
{
240
993
  Assert(mpat.getKind() == APPLY_CONSTRUCTOR);
241
993
  d_mpat_type = mpat.getType();
242
993
}
243
244
1349
void CandidateGeneratorConsExpand::reset(Node eqc)
245
{
246
1349
  d_term_iter = 0;
247
1349
  if (eqc.isNull())
248
  {
249
702
    d_mode = cand_term_db;
250
  }
251
  else
252
  {
253
647
    d_eqc = eqc;
254
647
    d_mode = cand_term_ident;
255
647
    Assert(d_eqc.getType() == d_mpat_type);
256
  }
257
1349
}
258
259
1677
Node CandidateGeneratorConsExpand::getNextCandidate()
260
{
261
  // get the next term from the base class
262
3354
  Node curr = getNextCandidateInternal();
263
1677
  if (curr.isNull() || (curr.hasOperator() && curr.getOperator() == d_op))
264
  {
265
1262
    return curr;
266
  }
267
  // expand it
268
415
  NodeManager* nm = NodeManager::currentNM();
269
830
  std::vector<Node> children;
270
415
  const DType& dt = d_mpat_type.getDType();
271
415
  Assert(dt.getNumConstructors() == 1);
272
415
  children.push_back(d_op);
273
1250
  for (unsigned i = 0, nargs = dt[0].getNumArgs(); i < nargs; i++)
274
  {
275
    Node sel = nm->mkNode(
276
1670
        APPLY_SELECTOR_TOTAL, dt[0].getSelectorInternal(d_mpat_type, i), curr);
277
835
    children.push_back(sel);
278
  }
279
415
  return nm->mkNode(APPLY_CONSTRUCTOR, children);
280
}
281
282
647
bool CandidateGeneratorConsExpand::isLegalOpCandidate(Node n)
283
{
284
647
  return isLegalCandidate(n);
285
}
286
287
82
CandidateGeneratorSelector::CandidateGeneratorSelector(QuantifiersState& qs,
288
                                                       TermRegistry& tr,
289
82
                                                       Node mpat)
290
82
    : CandidateGeneratorQE(qs, tr, mpat)
291
{
292
82
  Trace("sel-trigger") << "Selector trigger: " << mpat << std::endl;
293
82
  Assert(mpat.getKind() == APPLY_SELECTOR);
294
  // NOTE: could use qs.getValuation().getPreprocessedTerm(mpat); when
295
  // expand definitions is eliminated, however, this also requires avoiding
296
  // term formula removal.
297
164
  Node mpatExp = datatypes::DatatypesRewriter::expandApplySelector(mpat);
298
82
  Trace("sel-trigger") << "Expands to: " << mpatExp << std::endl;
299
82
  if (mpatExp.getKind() == ITE)
300
  {
301
82
    Assert(mpatExp[1].getKind() == APPLY_SELECTOR_TOTAL);
302
82
    Assert(mpatExp[2].getKind() == APPLY_UF);
303
82
    d_selOp = d_treg.getTermDatabase()->getMatchOperator(mpatExp[1]);
304
82
    d_ufOp = d_treg.getTermDatabase()->getMatchOperator(mpatExp[2]);
305
  }
306
  else if (mpatExp.getKind() == APPLY_SELECTOR_TOTAL)
307
  {
308
    // corner case of datatype with one constructor
309
    d_selOp = d_treg.getTermDatabase()->getMatchOperator(mpatExp);
310
  }
311
  else
312
  {
313
    // corner case of a wrongly applied selector as a trigger
314
    Assert(mpatExp.getKind() == APPLY_UF);
315
    d_ufOp = d_treg.getTermDatabase()->getMatchOperator(mpatExp);
316
  }
317
82
  Assert(d_selOp != d_ufOp);
318
82
}
319
320
1582
void CandidateGeneratorSelector::reset(Node eqc)
321
{
322
1582
  Trace("sel-trigger-debug") << "Reset in eqc=" << eqc << std::endl;
323
  // start with d_selOp, if it exists
324
1582
  resetForOperator(eqc, !d_selOp.isNull()? d_selOp : d_ufOp);
325
1582
}
326
327
3602
Node CandidateGeneratorSelector::getNextCandidate()
328
{
329
7204
  Node nextc = getNextCandidateInternal();
330
3602
  if (!nextc.isNull())
331
  {
332
1608
    Trace("sel-trigger-debug") << "...next candidate is " << nextc << std::endl;
333
1608
    return nextc;
334
  }
335
1994
  else if (d_op == d_selOp)
336
  {
337
1010
    if (d_ufOp.isNull())
338
    {
339
      // corner case: selector cannot be wrongly applied (1-cons case)
340
      d_op = Node::null();
341
    }
342
    else
343
    {
344
      // finished correctly applied selectors, now try incorrectly applied ones
345
1010
      resetForOperator(d_eqc, d_ufOp);
346
1010
      return getNextCandidate();
347
    }
348
  }
349
984
  Trace("sel-trigger-debug") << "...finished" << std::endl;
350
  // no more candidates
351
984
  return Node::null();
352
}
353
354
}  // namespace inst
355
}  // namespace quantifiers
356
}  // namespace theory
357
22746
}  // namespace cvc5