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GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/theory/arith/dual_simplex.cpp	Lines:	105	120	87.5 %
Date:	2021-09-29	Branches:	195	538	36.2 %


/******************************************************************************
 * Top contributors (to current version):
 *   Tim King, Aina Niemetz, Morgan Deters
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
 * in the top-level source directory and their institutional affiliations.
 * All rights reserved.  See the file COPYING in the top-level source
 * directory for licensing information.
 * ****************************************************************************
 *
 * This is an implementation of the Simplex Module for the Simplex for
 * DPLL(T) decision procedure.
 */
#include "theory/arith/dual_simplex.h"

#include "base/output.h"
#include "options/arith_options.h"
#include "smt/smt_statistics_registry.h"
#include "theory/arith/constraint.h"
#include "theory/arith/error_set.h"
#include "theory/arith/linear_equality.h"


using namespace std;

namespace cvc5 {
namespace theory {
namespace arith {

DualSimplexDecisionProcedure::DualSimplexDecisionProcedure(LinearEqualityModule& linEq, ErrorSet& errors, RaiseConflict conflictChannel, TempVarMalloc tvmalloc)
  : SimplexDecisionProcedure(linEq, errors, conflictChannel, tvmalloc)
  , d_pivotsInRound()
  , d_statistics(d_pivots)
{ }

DualSimplexDecisionProcedure::Statistics::Statistics(uint32_t& pivots)
    : d_statUpdateConflicts(smtStatisticsRegistry().registerInt(
        "theory::arith::dual::UpdateConflicts")),
      d_processSignalsTime(smtStatisticsRegistry().registerTimer(
          "theory::arith::dual::findConflictOnTheQueueTime")),
      d_simplexConflicts(smtStatisticsRegistry().registerInt(
          "theory::arith::dual::simplexConflicts")),
      d_recentViolationCatches(smtStatisticsRegistry().registerInt(
          "theory::arith::dual::recentViolationCatches")),
      d_searchTime(smtStatisticsRegistry().registerTimer(
          "theory::arith::dual::searchTime")),
      d_finalCheckPivotCounter(
          smtStatisticsRegistry().registerReference<uint32_t>(
              "theory::arith::dual::lastPivots", pivots))
{
}

Result::Sat DualSimplexDecisionProcedure::dualFindModel(bool exactResult){
  Assert(d_conflictVariables.empty());

  static thread_local unsigned int instance = 0;
  instance = instance + 1;
  d_pivots = 0;

  if(d_errorSet.errorEmpty() && !d_errorSet.moreSignals()){
    Debug("arith::findModel") << "dualFindModel("<< instance <<") trivial" << endl;
    return Result::SAT;
  }

  // We need to reduce this because of
  d_errorSet.reduceToSignals();
  d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);

  if(processSignals()){
    d_conflictVariables.purge();

    Debug("arith::findModel") << "dualFindModel("<< instance <<") early conflict" << endl;
    return Result::UNSAT;
  }else if(d_errorSet.errorEmpty()){
    Debug("arith::findModel") << "dualFindModel("<< instance <<") fixed itself" << endl;
    Assert(!d_errorSet.moreSignals());
    return Result::SAT;
  }

  Debug("arith::findModel") << "dualFindModel(" << instance <<") start non-trivial" << endl;

  Result::Sat result = Result::SAT_UNKNOWN;

  static const bool verbose = false;
  exactResult |= d_varOrderPivotLimit < 0;

  uint32_t checkPeriod = options::arithSimplexCheckPeriod();
  if(result == Result::SAT_UNKNOWN){
    uint32_t numDifferencePivots = options::arithHeuristicPivots() < 0 ?
      d_numVariables + 1 : options::arithHeuristicPivots();
    // The signed to unsigned conversion is safe.
    if(numDifferencePivots > 0){

      d_errorSet.setSelectionRule(d_heuristicRule);
      if(searchForFeasibleSolution(numDifferencePivots)){
        result = Result::UNSAT;
      }
    }

    if (verbose && numDifferencePivots > 0)
    {
      if (result == Result::UNSAT)
      {
        CVC5Message() << "diff order found unsat" << endl;
      }
      else if (d_errorSet.errorEmpty())
      {
        CVC5Message() << "diff order found model" << endl;
      }
      else
      {
        CVC5Message() << "diff order missed" << endl;
      }
    }
  }
  Assert(!d_errorSet.moreSignals());

  if(!d_errorSet.errorEmpty() && result != Result::UNSAT){
    if(exactResult){
      d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);
      while(!d_errorSet.errorEmpty() && result != Result::UNSAT){
        Assert(checkPeriod > 0);
        if(searchForFeasibleSolution(checkPeriod)){
          result = Result::UNSAT;
        }
      }
    }
    else if (d_varOrderPivotLimit > 0)
    {
      d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);
      if (searchForFeasibleSolution(d_varOrderPivotLimit))
      {
        result = Result::UNSAT;
      }
      if (verbose)
      {
        if (result == Result::UNSAT)
        {
          CVC5Message() << "restricted var order found unsat" << endl;
        }
        else if (d_errorSet.errorEmpty())
        {
          CVC5Message() << "restricted var order found model" << endl;
        }
        else
        {
          CVC5Message() << "restricted var order missed" << endl;
        }
      }
    }
  }

  Assert(!d_errorSet.moreSignals());
  if(result == Result::SAT_UNKNOWN && d_errorSet.errorEmpty()){
    result = Result::SAT;
  }

  d_pivotsInRound.purge();
  // ensure that the conflict variable is still in the queue.
  d_conflictVariables.purge();

  Debug("arith::findModel") << "end findModel() " << instance << " " << result <<  endl;

  return result;
}

//corresponds to Check() in dM06
//template <SimplexDecisionProcedure::PreferenceFunction pf>
bool DualSimplexDecisionProcedure::searchForFeasibleSolution(uint32_t remainingIterations){
  TimerStat::CodeTimer codeTimer(d_statistics.d_searchTime);

  Debug("arith") << "searchForFeasibleSolution" << endl;
  Assert(remainingIterations > 0);

  while(remainingIterations > 0 && !d_errorSet.focusEmpty()){
    if(Debug.isOn("paranoid:check_tableau")){ d_linEq.debugCheckTableau(); }
    Assert(d_conflictVariables.empty());
    ArithVar x_i = d_errorSet.topFocusVariable();

    Debug("arith::update::select") << "selectSmallestInconsistentVar()=" << x_i << endl;
    if(x_i == ARITHVAR_SENTINEL){
      Debug("arith::update") << "No inconsistent variables" << endl;
      return false; //sat
    }

    --remainingIterations;

    bool useVarOrderPivot = d_pivotsInRound.count(x_i) >=  options::arithPivotThreshold();
    if(!useVarOrderPivot){
      d_pivotsInRound.add(x_i);
    }


    Debug("arith::update")
      << "pivots in rounds: " <<  d_pivotsInRound.count(x_i)
      << " use " << useVarOrderPivot
      << " threshold " << options::arithPivotThreshold()
      << endl;

    LinearEqualityModule::VarPreferenceFunction pf = useVarOrderPivot ?
      &LinearEqualityModule::minVarOrder : &LinearEqualityModule::minBoundAndColLength;

    //DeltaRational beta_i = d_variables.getAssignment(x_i);
    ArithVar x_j = ARITHVAR_SENTINEL;

    int32_t prevErrorSize CVC5_UNUSED = d_errorSet.errorSize();

    if(d_variables.cmpAssignmentLowerBound(x_i) < 0 ){
      x_j = d_linEq.selectSlackUpperBound(x_i, pf);
      if(x_j == ARITHVAR_SENTINEL ){
        Unreachable();
        // ++(d_statistics.d_statUpdateConflicts);
        // reportConflict(x_i);
        // ++(d_statistics.d_simplexConflicts);
        // Node conflict = d_linEq.generateConflictBelowLowerBound(x_i); //unsat
        // d_conflictVariable = x_i;
        // reportConflict(conflict);
        // return true;
      }else{
        const DeltaRational& l_i = d_variables.getLowerBound(x_i);
        d_linEq.pivotAndUpdate(x_i, x_j, l_i);
      }
    }else if(d_variables.cmpAssignmentUpperBound(x_i) > 0){
      x_j = d_linEq.selectSlackLowerBound(x_i, pf);
      if(x_j == ARITHVAR_SENTINEL ){
        Unreachable();
        // ++(d_statistics.d_statUpdateConflicts);
        // reportConflict(x_i);
        // ++(d_statistics.d_simplexConflicts);
        // Node conflict = d_linEq.generateConflictAboveUpperBound(x_i); //unsat
        // d_conflictVariable = x_i;
        // reportConflict(conflict);
        // return true;
      }else{
        const DeltaRational& u_i = d_variables.getUpperBound(x_i);
        d_linEq.pivotAndUpdate(x_i, x_j, u_i);
      }
    }
    Assert(x_j != ARITHVAR_SENTINEL);

    bool conflict = processSignals();
    int32_t currErrorSize CVC5_UNUSED = d_errorSet.errorSize();
    d_pivots++;

    if(Debug.isOn("arith::dual")){
      Debug("arith::dual")
        << "#" << d_pivots
        << " c" << conflict
        << " d" << (prevErrorSize - currErrorSize)
        << " f"  << d_errorSet.inError(x_j)
        << " h" << d_conflictVariables.isMember(x_j)
        << " " << x_i << "->" << x_j
        << endl;
    }

    if(conflict){
      return true;
    }
  }
  Assert(!d_errorSet.focusEmpty() || d_errorSet.errorEmpty());
  Assert(remainingIterations == 0 || d_errorSet.focusEmpty());
  Assert(d_errorSet.noSignals());

  return false;
}

}  // namespace arith
}  // namespace theory
}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Tim King, Aina Niemetz, Morgan Deters
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		* This is an implementation of the Simplex Module for the Simplex for
14		* DPLL(T) decision procedure.
15		*/
16		#include "theory/arith/dual_simplex.h"
17
18		#include "base/output.h"
19		#include "options/arith_options.h"
20		#include "smt/smt_statistics_registry.h"
21		#include "theory/arith/constraint.h"
22		#include "theory/arith/error_set.h"
23		#include "theory/arith/linear_equality.h"
24
25
26		using namespace std;
27
28		namespace cvc5 {
29		namespace theory {
30		namespace arith {
31
32	6271	DualSimplexDecisionProcedure::DualSimplexDecisionProcedure(LinearEqualityModule& linEq, ErrorSet& errors, RaiseConflict conflictChannel, TempVarMalloc tvmalloc)
33		: SimplexDecisionProcedure(linEq, errors, conflictChannel, tvmalloc)
34		, d_pivotsInRound()
35	6271	, d_statistics(d_pivots)
36	6271	{ }
37
38	6271	DualSimplexDecisionProcedure::Statistics::Statistics(uint32_t& pivots)
39	6271	: d_statUpdateConflicts(smtStatisticsRegistry().registerInt(
40	12542	"theory::arith::dual::UpdateConflicts")),
41	6271	d_processSignalsTime(smtStatisticsRegistry().registerTimer(
42	12542	"theory::arith::dual::findConflictOnTheQueueTime")),
43	6271	d_simplexConflicts(smtStatisticsRegistry().registerInt(
44	12542	"theory::arith::dual::simplexConflicts")),
45	6271	d_recentViolationCatches(smtStatisticsRegistry().registerInt(
46	12542	"theory::arith::dual::recentViolationCatches")),
47	6271	d_searchTime(smtStatisticsRegistry().registerTimer(
48	12542	"theory::arith::dual::searchTime")),
49		d_finalCheckPivotCounter(
50	6271	smtStatisticsRegistry().registerReference<uint32_t>(
51	37626	"theory::arith::dual::lastPivots", pivots))
52		{
53	6271	}
54
55	1128716	Result::Sat DualSimplexDecisionProcedure::dualFindModel(bool exactResult){
56	1128716	Assert(d_conflictVariables.empty());
57
58		static thread_local unsigned int instance = 0;
59	1128716	instance = instance + 1;
60	1128716	d_pivots = 0;
61
62	1128716	if(d_errorSet.errorEmpty() && !d_errorSet.moreSignals()){
63	626417	Debug("arith::findModel") << "dualFindModel("<< instance <<") trivial" << endl;
64	626417	return Result::SAT;
65		}
66
67		// We need to reduce this because of
68	502299	d_errorSet.reduceToSignals();
69	502299	d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);
70
71	502299	if(processSignals()){
72	16524	d_conflictVariables.purge();
73
74	16524	Debug("arith::findModel") << "dualFindModel("<< instance <<") early conflict" << endl;
75	16524	return Result::UNSAT;
76	485775	}else if(d_errorSet.errorEmpty()){
77	429914	Debug("arith::findModel") << "dualFindModel("<< instance <<") fixed itself" << endl;
78	429914	Assert(!d_errorSet.moreSignals());
79	429914	return Result::SAT;
80		}
81
82	55861	Debug("arith::findModel") << "dualFindModel(" << instance <<") start non-trivial" << endl;
83
84	55861	Result::Sat result = Result::SAT_UNKNOWN;
85
86		static const bool verbose = false;
87	55861	exactResult \|= d_varOrderPivotLimit < 0;
88
89	55861	uint32_t checkPeriod = options::arithSimplexCheckPeriod();
90	55861	if(result == Result::SAT_UNKNOWN){
91	55861	uint32_t numDifferencePivots = options::arithHeuristicPivots() < 0 ?
92	55861	d_numVariables + 1 : options::arithHeuristicPivots();
93		// The signed to unsigned conversion is safe.
94	55861	if(numDifferencePivots > 0){
95
96	48622	d_errorSet.setSelectionRule(d_heuristicRule);
97	48622	if(searchForFeasibleSolution(numDifferencePivots)){
98	7808	result = Result::UNSAT;
99		}
100		}
101
102		if (verbose && numDifferencePivots > 0)
103		{
104		if (result == Result::UNSAT)
105		{
106		CVC5Message() << "diff order found unsat" << endl;
107		}
108		else if (d_errorSet.errorEmpty())
109		{
110		CVC5Message() << "diff order found model" << endl;
111		}
112		else
113		{
114		CVC5Message() << "diff order missed" << endl;
115		}
116		}
117		}
118	55861	Assert(!d_errorSet.moreSignals());
119
120	55861	if(!d_errorSet.errorEmpty() && result != Result::UNSAT){
121	8179	if(exactResult){
122	8179	d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);
123	24545	while(!d_errorSet.errorEmpty() && result != Result::UNSAT){
124	8183	Assert(checkPeriod > 0);
125	8183	if(searchForFeasibleSolution(checkPeriod)){
126	2497	result = Result::UNSAT;
127		}
128		}
129		}
130		else if (d_varOrderPivotLimit > 0)
131		{
132		d_errorSet.setSelectionRule(options::ErrorSelectionRule::VAR_ORDER);
133		if (searchForFeasibleSolution(d_varOrderPivotLimit))
134		{
135		result = Result::UNSAT;
136		}
137		if (verbose)
138		{
139		if (result == Result::UNSAT)
140		{
141		CVC5Message() << "restricted var order found unsat" << endl;
142		}
143		else if (d_errorSet.errorEmpty())
144		{
145		CVC5Message() << "restricted var order found model" << endl;
146		}
147		else
148		{
149		CVC5Message() << "restricted var order missed" << endl;
150		}
151		}
152		}
153		}
154
155	55861	Assert(!d_errorSet.moreSignals());
156	55861	if(result == Result::SAT_UNKNOWN && d_errorSet.errorEmpty()){
157	45556	result = Result::SAT;
158		}
159
160	55861	d_pivotsInRound.purge();
161		// ensure that the conflict variable is still in the queue.
162	55861	d_conflictVariables.purge();
163
164	55861	Debug("arith::findModel") << "end findModel() " << instance << " " << result << endl;
165
166	55861	return result;
167		}
168
169		//corresponds to Check() in dM06
170		//template <SimplexDecisionProcedure::PreferenceFunction pf>
171	56805	bool DualSimplexDecisionProcedure::searchForFeasibleSolution(uint32_t remainingIterations){
172	113610	TimerStat::CodeTimer codeTimer(d_statistics.d_searchTime);
173
174	56805	Debug("arith") << "searchForFeasibleSolution" << endl;
175	56805	Assert(remainingIterations > 0);
176
177	305979	while(remainingIterations > 0 && !d_errorSet.focusEmpty()){
178	134892	if(Debug.isOn("paranoid:check_tableau")){ d_linEq.debugCheckTableau(); }
179	134892	Assert(d_conflictVariables.empty());
180	134892	ArithVar x_i = d_errorSet.topFocusVariable();
181
182	134892	Debug("arith::update::select") << "selectSmallestInconsistentVar()=" << x_i << endl;
183	134892	if(x_i == ARITHVAR_SENTINEL){
184		Debug("arith::update") << "No inconsistent variables" << endl;
185	10305	return false; //sat
186		}
187
188	134892	--remainingIterations;
189
190	134892	bool useVarOrderPivot = d_pivotsInRound.count(x_i) >= options::arithPivotThreshold();
191	134892	if(!useVarOrderPivot){
192	134785	d_pivotsInRound.add(x_i);
193		}
194
195
196	269784	Debug("arith::update")
197	269784	<< "pivots in rounds: " << d_pivotsInRound.count(x_i)
198	134892	<< " use " << useVarOrderPivot
199	269784	<< " threshold " << options::arithPivotThreshold()
200	134892	<< endl;
201
202	134892	LinearEqualityModule::VarPreferenceFunction pf = useVarOrderPivot ?
203		&LinearEqualityModule::minVarOrder : &LinearEqualityModule::minBoundAndColLength;
204
205		//DeltaRational beta_i = d_variables.getAssignment(x_i);
206	134892	ArithVar x_j = ARITHVAR_SENTINEL;
207
208	134892	int32_t prevErrorSize CVC5_UNUSED = d_errorSet.errorSize();
209
210	134892	if(d_variables.cmpAssignmentLowerBound(x_i) < 0 ){
211	76635	x_j = d_linEq.selectSlackUpperBound(x_i, pf);
212	76635	if(x_j == ARITHVAR_SENTINEL ){
213		Unreachable();
214		// ++(d_statistics.d_statUpdateConflicts);
215		// reportConflict(x_i);
216		// ++(d_statistics.d_simplexConflicts);
217		// Node conflict = d_linEq.generateConflictBelowLowerBound(x_i); //unsat
218		// d_conflictVariable = x_i;
219		// reportConflict(conflict);
220		// return true;
221		}else{
222	76635	const DeltaRational& l_i = d_variables.getLowerBound(x_i);
223	76635	d_linEq.pivotAndUpdate(x_i, x_j, l_i);
224		}
225	58257	}else if(d_variables.cmpAssignmentUpperBound(x_i) > 0){
226	58257	x_j = d_linEq.selectSlackLowerBound(x_i, pf);
227	58257	if(x_j == ARITHVAR_SENTINEL ){
228		Unreachable();
229		// ++(d_statistics.d_statUpdateConflicts);
230		// reportConflict(x_i);
231		// ++(d_statistics.d_simplexConflicts);
232		// Node conflict = d_linEq.generateConflictAboveUpperBound(x_i); //unsat
233		// d_conflictVariable = x_i;
234		// reportConflict(conflict);
235		// return true;
236		}else{
237	58257	const DeltaRational& u_i = d_variables.getUpperBound(x_i);
238	58257	d_linEq.pivotAndUpdate(x_i, x_j, u_i);
239		}
240		}
241	134892	Assert(x_j != ARITHVAR_SENTINEL);
242
243	134892	bool conflict = processSignals();
244	134892	int32_t currErrorSize CVC5_UNUSED = d_errorSet.errorSize();
245	134892	d_pivots++;
246
247	134892	if(Debug.isOn("arith::dual")){
248		Debug("arith::dual")
249		<< "#" << d_pivots
250		<< " c" << conflict
251		<< " d" << (prevErrorSize - currErrorSize)
252		<< " f" << d_errorSet.inError(x_j)
253		<< " h" << d_conflictVariables.isMember(x_j)
254		<< " " << x_i << "->" << x_j
255		<< endl;
256		}
257
258	134892	if(conflict){
259	10305	return true;
260		}
261		}
262	46500	Assert(!d_errorSet.focusEmpty() \|\| d_errorSet.errorEmpty());
263	46500	Assert(remainingIterations == 0 \|\| d_errorSet.focusEmpty());
264	46500	Assert(d_errorSet.noSignals());
265
266	46500	return false;
267		}
268
269		} // namespace arith
270		} // namespace theory
271	22746	} // namespace cvc5