1 |
|
/****************************************************************************** |
2 |
|
* Top contributors (to current version): |
3 |
|
* Aina Niemetz, Tim King, Andrew Reynolds |
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 |
|
* ITE simplification preprocessing pass. |
14 |
|
*/ |
15 |
|
|
16 |
|
#include "preprocessing/passes/ite_simp.h" |
17 |
|
|
18 |
|
#include <vector> |
19 |
|
|
20 |
|
#include "options/base_options.h" |
21 |
|
#include "options/smt_options.h" |
22 |
|
#include "preprocessing/assertion_pipeline.h" |
23 |
|
#include "preprocessing/preprocessing_pass_context.h" |
24 |
|
#include "smt/smt_statistics_registry.h" |
25 |
|
#include "smt_util/nary_builder.h" |
26 |
|
#include "theory/arith/arith_ite_utils.h" |
27 |
|
#include "theory/theory_engine.h" |
28 |
|
|
29 |
|
using namespace std; |
30 |
|
using namespace cvc5; |
31 |
|
using namespace cvc5::theory; |
32 |
|
|
33 |
|
namespace cvc5 { |
34 |
|
namespace preprocessing { |
35 |
|
namespace passes { |
36 |
|
|
37 |
|
/* -------------------------------------------------------------------------- */ |
38 |
|
|
39 |
|
namespace { |
40 |
|
|
41 |
|
/** |
42 |
|
* Ensures the assertions asserted after index 'before' now effectively come |
43 |
|
* before 'real_assertions_end'. |
44 |
|
*/ |
45 |
1 |
void compressBeforeRealAssertions(AssertionPipeline* assertionsToPreprocess, |
46 |
|
size_t before) |
47 |
|
{ |
48 |
1 |
size_t cur_size = assertionsToPreprocess->size(); |
49 |
2 |
if (before >= cur_size || assertionsToPreprocess->getRealAssertionsEnd() <= 0 |
50 |
2 |
|| assertionsToPreprocess->getRealAssertionsEnd() >= cur_size) |
51 |
|
{ |
52 |
|
return; |
53 |
|
} |
54 |
|
|
55 |
|
// assertions |
56 |
|
// original: [0 ... assertionsToPreprocess.getRealAssertionsEnd()) |
57 |
|
// can be modified |
58 |
|
// ites skolems [assertionsToPreprocess.getRealAssertionsEnd(), before) |
59 |
|
// cannot be moved |
60 |
|
// added [before, cur_size) |
61 |
|
// can be modified |
62 |
1 |
Assert(0 < assertionsToPreprocess->getRealAssertionsEnd()); |
63 |
1 |
Assert(assertionsToPreprocess->getRealAssertionsEnd() <= before); |
64 |
1 |
Assert(before < cur_size); |
65 |
|
|
66 |
2 |
std::vector<Node> intoConjunction; |
67 |
1210 |
for (size_t i = before; i < cur_size; ++i) |
68 |
|
{ |
69 |
1209 |
intoConjunction.push_back((*assertionsToPreprocess)[i]); |
70 |
|
} |
71 |
1 |
assertionsToPreprocess->resize(before); |
72 |
1 |
size_t lastBeforeItes = assertionsToPreprocess->getRealAssertionsEnd() - 1; |
73 |
1 |
intoConjunction.push_back((*assertionsToPreprocess)[lastBeforeItes]); |
74 |
2 |
Node newLast = cvc5::util::NaryBuilder::mkAssoc(kind::AND, intoConjunction); |
75 |
1 |
assertionsToPreprocess->replace(lastBeforeItes, newLast); |
76 |
1 |
Assert(assertionsToPreprocess->size() == before); |
77 |
|
} |
78 |
|
|
79 |
|
} // namespace |
80 |
|
|
81 |
|
/* -------------------------------------------------------------------------- */ |
82 |
|
|
83 |
9942 |
ITESimp::Statistics::Statistics(StatisticsRegistry& reg) |
84 |
|
: d_arithSubstitutionsAdded(reg.registerInt( |
85 |
9942 |
"preprocessing::passes::ITESimp::ArithSubstitutionsAdded")) |
86 |
|
{ |
87 |
9942 |
} |
88 |
|
|
89 |
2 |
Node ITESimp::simpITE(util::ITEUtilities* ite_utils, TNode assertion) |
90 |
|
{ |
91 |
2 |
if (!ite_utils->containsTermITE(assertion)) |
92 |
|
{ |
93 |
1 |
return assertion; |
94 |
|
} |
95 |
|
else |
96 |
|
{ |
97 |
2 |
Node result = ite_utils->simpITE(assertion); |
98 |
2 |
Node res_rewritten = rewrite(result); |
99 |
|
|
100 |
1 |
if (options().smt.simplifyWithCareEnabled) |
101 |
|
{ |
102 |
|
Chat() << "starting simplifyWithCare()" << endl; |
103 |
|
Node postSimpWithCare = ite_utils->simplifyWithCare(res_rewritten); |
104 |
|
Chat() << "ending simplifyWithCare()" |
105 |
|
<< " post simplifyWithCare()" << postSimpWithCare.getId() << endl; |
106 |
|
result = rewrite(postSimpWithCare); |
107 |
|
} |
108 |
|
else |
109 |
|
{ |
110 |
1 |
result = res_rewritten; |
111 |
|
} |
112 |
1 |
return result; |
113 |
|
} |
114 |
|
} |
115 |
|
|
116 |
1 |
bool ITESimp::doneSimpITE(AssertionPipeline* assertionsToPreprocess) |
117 |
|
{ |
118 |
1 |
bool result = true; |
119 |
1 |
bool simpDidALotOfWork = d_iteUtilities.simpIteDidALotOfWorkHeuristic(); |
120 |
1 |
if (simpDidALotOfWork) |
121 |
|
{ |
122 |
1 |
if (options().smt.compressItes) |
123 |
|
{ |
124 |
1 |
result = d_iteUtilities.compress(assertionsToPreprocess); |
125 |
|
} |
126 |
|
|
127 |
1 |
if (result) |
128 |
|
{ |
129 |
|
// if false, don't bother to reclaim memory here. |
130 |
1 |
NodeManager* nm = NodeManager::currentNM(); |
131 |
1 |
if (nm->poolSize() >= options().smt.zombieHuntThreshold) |
132 |
|
{ |
133 |
|
Chat() << "..ite simplifier did quite a bit of work.. " |
134 |
|
<< nm->poolSize() << endl; |
135 |
|
Chat() << "....node manager contains " << nm->poolSize() |
136 |
|
<< " nodes before cleanup" << endl; |
137 |
|
d_iteUtilities.clear(); |
138 |
|
d_env.getRewriter()->clearCaches(); |
139 |
|
nm->reclaimZombiesUntil(options().smt.zombieHuntThreshold); |
140 |
|
Chat() << "....node manager contains " << nm->poolSize() |
141 |
|
<< " nodes after cleanup" << endl; |
142 |
|
} |
143 |
|
} |
144 |
|
} |
145 |
|
|
146 |
|
// Do theory specific preprocessing passes |
147 |
2 |
if (logicInfo().isTheoryEnabled(theory::THEORY_ARITH) |
148 |
1 |
&& !options().base.incrementalSolving) |
149 |
|
{ |
150 |
1 |
if (!simpDidALotOfWork) |
151 |
|
{ |
152 |
|
util::ContainsTermITEVisitor& contains = |
153 |
|
*(d_iteUtilities.getContainsVisitor()); |
154 |
|
arith::ArithIteUtils aiteu( |
155 |
|
contains, |
156 |
|
userContext(), |
157 |
|
d_preprocContext->getTopLevelSubstitutions().get()); |
158 |
|
bool anyItes = false; |
159 |
|
for (size_t i = 0, size = assertionsToPreprocess->size(); i < size; ++i) |
160 |
|
{ |
161 |
|
Node curr = (*assertionsToPreprocess)[i]; |
162 |
|
if (contains.containsTermITE(curr)) |
163 |
|
{ |
164 |
|
anyItes = true; |
165 |
|
Node res = aiteu.reduceVariablesInItes(curr); |
166 |
|
Debug("arith::ite::red") << "@ " << i << " ... " << curr << endl |
167 |
|
<< " ->" << res << endl; |
168 |
|
if (curr != res) |
169 |
|
{ |
170 |
|
Node more = aiteu.reduceConstantIteByGCD(res); |
171 |
|
Debug("arith::ite::red") << " gcd->" << more << endl; |
172 |
|
Node morer = rewrite(more); |
173 |
|
assertionsToPreprocess->replace(i, morer); |
174 |
|
} |
175 |
|
} |
176 |
|
} |
177 |
|
if (!anyItes) |
178 |
|
{ |
179 |
|
unsigned prevSubCount = aiteu.getSubCount(); |
180 |
|
aiteu.learnSubstitutions(assertionsToPreprocess->ref()); |
181 |
|
if (prevSubCount < aiteu.getSubCount()) |
182 |
|
{ |
183 |
|
d_statistics.d_arithSubstitutionsAdded += |
184 |
|
aiteu.getSubCount() - prevSubCount; |
185 |
|
bool anySuccess = false; |
186 |
|
for (size_t i = 0, N = assertionsToPreprocess->size(); i < N; ++i) |
187 |
|
{ |
188 |
|
Node curr = (*assertionsToPreprocess)[i]; |
189 |
|
Node next = rewrite(aiteu.applySubstitutions(curr)); |
190 |
|
Node res = aiteu.reduceVariablesInItes(next); |
191 |
|
Debug("arith::ite::red") << "@ " << i << " ... " << next << endl |
192 |
|
<< " ->" << res << endl; |
193 |
|
Node more = aiteu.reduceConstantIteByGCD(res); |
194 |
|
Debug("arith::ite::red") << " gcd->" << more << endl; |
195 |
|
if (more != next) |
196 |
|
{ |
197 |
|
anySuccess = true; |
198 |
|
break; |
199 |
|
} |
200 |
|
} |
201 |
|
for (size_t i = 0, N = assertionsToPreprocess->size(); |
202 |
|
anySuccess && i < N; |
203 |
|
++i) |
204 |
|
{ |
205 |
|
Node curr = (*assertionsToPreprocess)[i]; |
206 |
|
Node next = rewrite(aiteu.applySubstitutions(curr)); |
207 |
|
Node res = aiteu.reduceVariablesInItes(next); |
208 |
|
Debug("arith::ite::red") << "@ " << i << " ... " << next << endl |
209 |
|
<< " ->" << res << endl; |
210 |
|
Node more = aiteu.reduceConstantIteByGCD(res); |
211 |
|
Debug("arith::ite::red") << " gcd->" << more << endl; |
212 |
|
Node morer = rewrite(more); |
213 |
|
assertionsToPreprocess->replace(i, morer); |
214 |
|
} |
215 |
|
} |
216 |
|
} |
217 |
|
} |
218 |
|
} |
219 |
1 |
return result; |
220 |
|
} |
221 |
|
|
222 |
|
/* -------------------------------------------------------------------------- */ |
223 |
|
|
224 |
9942 |
ITESimp::ITESimp(PreprocessingPassContext* preprocContext) |
225 |
|
: PreprocessingPass(preprocContext, "ite-simp"), |
226 |
|
d_iteUtilities(d_env), |
227 |
9942 |
d_statistics(statisticsRegistry()) |
228 |
|
{ |
229 |
9942 |
} |
230 |
|
|
231 |
1 |
PreprocessingPassResult ITESimp::applyInternal( |
232 |
|
AssertionPipeline* assertionsToPreprocess) |
233 |
|
{ |
234 |
1 |
d_preprocContext->spendResource(Resource::PreprocessStep); |
235 |
|
|
236 |
1 |
size_t nasserts = assertionsToPreprocess->size(); |
237 |
3 |
for (size_t i = 0; i < nasserts; ++i) |
238 |
|
{ |
239 |
2 |
d_preprocContext->spendResource(Resource::PreprocessStep); |
240 |
4 |
Node simp = simpITE(&d_iteUtilities, (*assertionsToPreprocess)[i]); |
241 |
2 |
assertionsToPreprocess->replace(i, simp); |
242 |
2 |
if (simp.isConst() && !simp.getConst<bool>()) |
243 |
|
{ |
244 |
|
return PreprocessingPassResult::CONFLICT; |
245 |
|
} |
246 |
|
} |
247 |
1 |
bool done = doneSimpITE(assertionsToPreprocess); |
248 |
1 |
if (nasserts < assertionsToPreprocess->size()) |
249 |
|
{ |
250 |
1 |
compressBeforeRealAssertions(assertionsToPreprocess, nasserts); |
251 |
|
} |
252 |
1 |
return done ? PreprocessingPassResult::NO_CONFLICT |
253 |
1 |
: PreprocessingPassResult::CONFLICT; |
254 |
|
} |
255 |
|
|
256 |
|
|
257 |
|
/* -------------------------------------------------------------------------- */ |
258 |
|
|
259 |
|
} // namespace passes |
260 |
|
} // namespace preprocessing |
261 |
29577 |
} // namespace cvc5 |