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/********************* */
/*! \file glucose.cpp
** \verbatim
** Original author: lianah
** Major contributors:
** Minor contributors (to current version):
** This file is part of the CVC4 prototype.
** Copyright (c) 2009-2014 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief SAT Solver.
**
** Implementation of the glucose sat solver for cvc4 (bitvectors).
**/
#include "prop/glucose.h"
#include "smt/options.h"
#ifdef CVC4_USE_GLUCOSE
using namespace CVC4;
using namespace prop;
GlucoseSolver::GlucoseSolver(const std::string& name)
: d_solver(new Glucose::SimpSolver())
, d_statistics(name)
{
d_solver->verbosity = -1;
if (CVC4::options::produceModels()) {
// FIXME: we don't want to freeze everything
d_solver->use_elim = false;
}
d_true = newVar();
d_false = newVar();
d_solver->addClause(Glucose::mkLit(d_true, false));
d_solver->addClause(Glucose::mkLit(d_false, true));
}
GlucoseSolver::~GlucoseSolver() throw(AssertionException) {
delete d_solver;
}
void GlucoseSolver::addClause(SatClause& clause, bool removable, uint64_t proof_id) {
Debug("sat::glucose") << "Add clause " << clause <<"\n";
if (!d_solver->okay()) {
Debug("sat::glucose") << "Solver unsat: not adding clause.\n";
return;
}
++(d_statistics.d_clausesAdded);
Glucose::vec<Glucose::Lit> internal_clause;
toInternalClause(clause, internal_clause);
d_solver->addClause(internal_clause); // check return status?
}
SatVariable GlucoseSolver::newVar(bool isTheoryAtom, bool preRegister, bool canErase){
return d_solver->newVar();
}
SatVariable GlucoseSolver::trueVar() {
return d_true;
}
SatVariable GlucoseSolver::falseVar() {
return d_false;
}
void GlucoseSolver::markUnremovable(SatLiteral lit) {
d_solver->setFrozen(lit.getSatVariable(), true);
return;
}
void GlucoseSolver::interrupt(){
d_solver->interrupt();
}
SatValue GlucoseSolver::solve(){
TimerStat::CodeTimer codeTimer(d_statistics.d_solveTime);
++d_statistics.d_statCallsToSolve;
return toSatLiteralValue(d_solver->solve());
}
SatValue GlucoseSolver::solve(long unsigned int& resource) {
TimerStat::CodeTimer codeTimer(d_statistics.d_solveTime);
if(resource == 0) {
d_solver->budgetOff();
} else {
d_solver->setConfBudget(resource);
}
return solve();
}
SatValue GlucoseSolver::value(SatLiteral l){
Assert (! d_solver->isEliminated(Glucose::var(toInternalLit(l))));
// For some reason value returns unknown for glucose
return toSatLiteralValue(d_solver->modelValue(toInternalLit(l)));
}
SatValue GlucoseSolver::modelValue(SatLiteral l){
return toSatLiteralValue(d_solver->modelValue(toInternalLit(l)));
}
unsigned GlucoseSolver::getAssertionLevel() const {
Unreachable("No interface to get assertion level in Glucose");
return -1;
}
// converting from internal sat solver representation
SatVariable GlucoseSolver::toSatVariable(Glucose::Var var) {
if (var == Glucose::Var(-1)) {
return undefSatVariable;
}
return SatVariable(var);
}
Glucose::Lit GlucoseSolver::toInternalLit(SatLiteral lit) {
if (lit == undefSatLiteral) {
return Glucose::lit_Undef;
}
return Glucose::mkLit(lit.getSatVariable(), lit.isNegated());
}
SatLiteral GlucoseSolver::toSatLiteral(Glucose::Lit lit) {
if (lit == Glucose::lit_Undef) {
return undefSatLiteral;
}
return SatLiteral(SatVariable(Glucose::var(lit)),
Glucose::sign(lit));
}
SatValue GlucoseSolver::toSatLiteralValue(Glucose::lbool res) {
if(res == Glucose::lbool((uint8_t)0)/*Glucose::l_True*/) return SAT_VALUE_TRUE;
if(res == Glucose::lbool((uint8_t)2)/*Glucose::l_Undef*/) return SAT_VALUE_UNKNOWN;
Assert(res == Glucose::lbool((uint8_t)1)/*Glucose::l_False*/);
return SAT_VALUE_FALSE;
}
SatValue GlucoseSolver::toSatLiteralValue(bool res) {
if(res) return SAT_VALUE_TRUE;
return SAT_VALUE_FALSE;
}
void GlucoseSolver::toInternalClause(SatClause& clause,
Glucose::vec<Glucose::Lit>& internal_clause) {
for (unsigned i = 0; i < clause.size(); ++i) {
internal_clause.push(toInternalLit(clause[i]));
}
Assert(clause.size() == (unsigned)internal_clause.size());
}
void GlucoseSolver::toSatClause(Glucose::vec<Glucose::Lit>& clause,
SatClause& sat_clause) {
for (int i = 0; i < clause.size(); ++i) {
sat_clause.push_back(toSatLiteral(clause[i]));
}
Assert((unsigned)clause.size() == sat_clause.size());
}
// Satistics for GlucoseSolver
GlucoseSolver::Statistics::Statistics(const std::string& prefix) :
d_statCallsToSolve("theory::bv::"+prefix+"::glucose::calls_to_solve", 0),
d_xorClausesAdded("theory::bv::"+prefix+"::glucose::xor_clauses", 0),
d_clausesAdded("theory::bv::"+prefix+"::glucose::clauses", 0),
d_solveTime("theory::bv::"+prefix+"::glucose::solve_time"),
d_registerStats(!prefix.empty())
{
if (!d_registerStats)
return;
StatisticsRegistry::registerStat(&d_statCallsToSolve);
StatisticsRegistry::registerStat(&d_xorClausesAdded);
StatisticsRegistry::registerStat(&d_clausesAdded);
StatisticsRegistry::registerStat(&d_solveTime);
}
GlucoseSolver::Statistics::~Statistics() {
if (!d_registerStats)
return;
StatisticsRegistry::unregisterStat(&d_statCallsToSolve);
StatisticsRegistry::unregisterStat(&d_xorClausesAdded);
StatisticsRegistry::unregisterStat(&d_clausesAdded);
StatisticsRegistry::unregisterStat(&d_solveTime);
}
#endif // CVC4_USE_GLUCOSE
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