yosys/libs/ezsat/ezminisat.cc

135 lines
3.2 KiB
C++

/*
* ezSAT -- A simple and easy to use CNF generator for SAT solvers
*
* Copyright (C) 2013 Clifford Wolf <clifford@clifford.at>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#define __STDC_LIMIT_MACROS 1
#include "ezminisat.h"
#include <limits.h>
#include <stdint.h>
#include <cinttypes>
#include "minisat/core/Solver.h"
ezMiniSAT::ezMiniSAT() : minisatSolver(NULL)
{
minisatSolver = NULL;
foundContradiction = false;
}
ezMiniSAT::~ezMiniSAT()
{
if (minisatSolver != NULL)
delete minisatSolver;
}
void ezMiniSAT::clear()
{
if (minisatSolver != NULL) {
delete minisatSolver;
minisatSolver = NULL;
}
foundContradiction = false;
minisatVars.clear();
ezSAT::clear();
}
bool ezMiniSAT::solver(const std::vector<int> &modelExpressions, std::vector<bool> &modelValues, const std::vector<int> &assumptions)
{
if (0) {
contradiction:
delete minisatSolver;
minisatSolver = NULL;
minisatVars.clear();
foundContradiction = true;
return false;
}
if (foundContradiction) {
consumeCnf();
return false;
}
std::vector<int> extraClauses, modelIdx;
for (auto id : assumptions)
extraClauses.push_back(bind(id));
for (auto id : modelExpressions)
modelIdx.push_back(bind(id));
if (minisatSolver == NULL)
minisatSolver = new Minisat::Solver;
std::vector<std::vector<int>> cnf;
consumeCnf(cnf);
while (int(minisatVars.size()) < numCnfVariables())
minisatVars.push_back(minisatSolver->newVar());
for (auto &clause : cnf) {
Minisat::vec<Minisat::Lit> ps;
for (auto idx : clause)
if (idx > 0)
ps.push(Minisat::mkLit(minisatVars.at(idx-1)));
else
ps.push(Minisat::mkLit(minisatVars.at(-idx-1), true));
if (!minisatSolver->addClause(ps))
goto contradiction;
}
if (cnf.size() > 0 && !minisatSolver->simplify())
goto contradiction;
Minisat::vec<Minisat::Lit> assumps;
for (auto idx : extraClauses)
if (idx > 0)
assumps.push(Minisat::mkLit(minisatVars.at(idx-1)));
else
assumps.push(Minisat::mkLit(minisatVars.at(-idx-1), true));
if (!minisatSolver->solve(assumps))
return false;
modelValues.clear();
modelValues.resize(2 * modelIdx.size());
for (size_t i = 0; i < modelIdx.size(); i++)
{
int idx = modelIdx[i];
bool refvalue = true;
if (idx < 0)
idx = -idx, refvalue = false;
using namespace Minisat;
lbool value = minisatSolver->modelValue(minisatVars.at(idx-1));
if (value == l_Undef) {
modelValues[i] = false;
modelValues[modelIdx.size() + i] = true;
} else {
modelValues[i] = value == Minisat::lbool(refvalue);
modelValues[modelIdx.size() + i] = false;
}
}
return true;
}