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/********************* */
/*! \file cadical.cpp
** \verbatim
** Top contributors (to current version):
** Mathias Preiner, Liana Hadarean
** This file is part of the CVC4 project.
** Copyright (c) 2009-2019 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.\endverbatim
**
** \brief Wrapper for CaDiCaL SAT Solver.
**
** Implementation of the CaDiCaL SAT solver for CVC4 (bitvectors).
**/
#include "prop/cadical.h"
#ifdef CVC4_USE_CADICAL
#include "proof/sat_proof.h"
namespace CVC4 {
namespace prop {
using CadicalLit = int;
using CadicalVar = int;
// helper functions
namespace {
SatValue toSatValue(int result)
{
if (result == 10) return SAT_VALUE_TRUE;
if (result == 20) return SAT_VALUE_FALSE;
Assert(result == 0);
return SAT_VALUE_UNKNOWN;
}
/* Note: CaDiCaL returns lit/-lit for true/false. Older versions returned 1/-1.
*/
SatValue toSatValueLit(int value)
{
if (value > 0) return SAT_VALUE_TRUE;
Assert(value < 0);
return SAT_VALUE_FALSE;
}
CadicalLit toCadicalLit(const SatLiteral lit)
{
return lit.isNegated() ? -lit.getSatVariable() : lit.getSatVariable();
}
CadicalVar toCadicalVar(SatVariable var) { return var; }
} // namespace helper functions
CadicalSolver::CadicalSolver(StatisticsRegistry* registry,
const std::string& name)
: d_solver(new CaDiCaL::Solver()),
// Note: CaDiCaL variables start with index 1 rather than 0 since negated
// literals are represented as the negation of the index.
d_nextVarIdx(1),
d_statistics(registry, name)
{
d_true = newVar();
d_false = newVar();
d_solver->set("quiet", 1); // CaDiCaL is verbose by default
d_solver->add(toCadicalVar(d_true));
d_solver->add(0);
d_solver->add(-toCadicalVar(d_false));
d_solver->add(0);
}
CadicalSolver::~CadicalSolver() {}
ClauseId CadicalSolver::addClause(SatClause& clause, bool removable)
{
for (const SatLiteral& lit : clause)
{
d_solver->add(toCadicalLit(lit));
}
d_solver->add(0);
++d_statistics.d_numClauses;
return ClauseIdError;
}
ClauseId CadicalSolver::addXorClause(SatClause& clause,
bool rhs,
bool removable)
{
Unreachable("CaDiCaL does not support adding XOR clauses.");
}
SatVariable CadicalSolver::newVar(bool isTheoryAtom,
bool preRegister,
bool canErase)
{
++d_statistics.d_numVariables;
return d_nextVarIdx++;
}
SatVariable CadicalSolver::trueVar() { return d_true; }
SatVariable CadicalSolver::falseVar() { return d_false; }
SatValue CadicalSolver::solve()
{
TimerStat::CodeTimer codeTimer(d_statistics.d_solveTime);
SatValue res = toSatValue(d_solver->solve());
d_okay = (res == SAT_VALUE_TRUE);
++d_statistics.d_numSatCalls;
return res;
}
SatValue CadicalSolver::solve(long unsigned int&)
{
Unimplemented("Setting limits for CaDiCaL not supported yet");
};
SatValue CadicalSolver::solve(const std::vector<SatLiteral>& assumptions)
{
TimerStat::CodeTimer codeTimer(d_statistics.d_solveTime);
for (const SatLiteral& lit : assumptions)
{
d_solver->assume(toCadicalLit(lit));
}
SatValue res = toSatValue(d_solver->solve());
d_okay = (res == SAT_VALUE_TRUE);
++d_statistics.d_numSatCalls;
return res;
}
void CadicalSolver::interrupt() { d_solver->terminate(); }
SatValue CadicalSolver::value(SatLiteral l)
{
Assert(d_okay);
return toSatValueLit(d_solver->val(toCadicalLit(l)));
}
SatValue CadicalSolver::modelValue(SatLiteral l)
{
Assert(d_okay);
return value(l);
}
unsigned CadicalSolver::getAssertionLevel() const
{
Unreachable("CaDiCal does not support assertion levels.");
}
bool CadicalSolver::ok() const { return d_okay; }
CadicalSolver::Statistics::Statistics(StatisticsRegistry* registry,
const std::string& prefix)
: d_registry(registry),
d_numSatCalls("theory::bv::" + prefix + "::cadical::calls_to_solve", 0),
d_numVariables("theory::bv::" + prefix + "::cadical::variables", 0),
d_numClauses("theory::bv::" + prefix + "::cadical::clauses", 0),
d_solveTime("theory::bv::" + prefix + "::cadical::solve_time")
{
d_registry->registerStat(&d_numSatCalls);
d_registry->registerStat(&d_numVariables);
d_registry->registerStat(&d_numClauses);
d_registry->registerStat(&d_solveTime);
}
CadicalSolver::Statistics::~Statistics() {
d_registry->unregisterStat(&d_numSatCalls);
d_registry->unregisterStat(&d_numVariables);
d_registry->unregisterStat(&d_numClauses);
d_registry->unregisterStat(&d_solveTime);
}
} // namespace prop
} // namespace CVC4
#endif // CVC4_USE_CADICAL
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