void ToSATAIG::add_cnf_to_solver(SATSolver& satSolver, Cnf_Dat_t* cnfData)
{
bm->GetRunTimes()->start(RunTimes::SendingToSAT);
// Create a new sat variable for each of the variables in the CNF.
int satV = satSolver.nVars();
for (int i = 0; i < cnfData->nVars - satV; i++)
satSolver.newVar();
SATSolver::vec_literals satSolverClause;
for (int i = 0; i < cnfData->nClauses; i++)
{
satSolverClause.clear();
for (int* pLit = cnfData->pClauses[i], *pStop = cnfData->pClauses[i + 1];
pLit < pStop; pLit++)
{
uint32_t var = (*pLit) >> 1;
assert((var < satSolver.nVars()));
Minisat::Lit l = SATSolver::mkLit(var, (*pLit) & 1);
satSolverClause.push(l);
}
satSolver.addClause(satSolverClause);
if (!satSolver.okay())
break;
}
bm->GetRunTimes()->stop(RunTimes::SendingToSAT);
}
void
applyAxiomToSAT(SATSolver & SatSolver, AxiomToBe& toBe, ToSATBase::ASTNodeToSATVar & satVar)
{
Minisat::Var a = getEquals(SatSolver, toBe.index0, toBe.index1, satVar, LEFT_ONLY);
Minisat::Var b = getEquals(SatSolver, toBe.value0, toBe.value1, satVar, RIGHT_ONLY);
SATSolver::vec_literals satSolverClause;
satSolverClause.push(SATSolver::mkLit(a, true));
satSolverClause.push(SATSolver::mkLit(b, false));
SatSolver.addClause(satSolverClause);
}
// This function adds the clauses to constrain that "a" and "b" equal a fresh
// variable
// (which it returns).
// Because it's used to create array axionms (a=b)-> (c=d), it can be
// used to only add one of the two polarities.
Minisat::Var getEquals(SATSolver& SatSolver, const ASTNode& a, const ASTNode& b,
ToSATBase::ASTNodeToSATVar& satVar,
Polarity polary = BOTH)
{
const unsigned width = a.GetValueWidth();
assert(width == b.GetValueWidth());
assert(!a.isConstant() || !b.isConstant());
vector<unsigned> v_a;
vector<unsigned> v_b;
getSatVariables(a, v_a, SatSolver, satVar);
getSatVariables(b, v_b, SatSolver, satVar);
// The only time v_a or v_b will be empty is if "a" resp. "b" is a constant.
if (v_a.size() == width && v_b.size() == width)
{
SATSolver::vec_literals all;
const int result = SatSolver.newVar();
for (unsigned i = 0; i < width; i++)
{
SATSolver::vec_literals s;
if (polary != RIGHT_ONLY)
{
int nv0 = SatSolver.newVar();
s.push(SATSolver::mkLit(v_a[i], true));
s.push(SATSolver::mkLit(v_b[i], true));
s.push(SATSolver::mkLit(nv0, false));
SatSolver.addClause(s);
s.clear();
s.push(SATSolver::mkLit(v_a[i], false));
s.push(SATSolver::mkLit(v_b[i], false));
s.push(SATSolver::mkLit(nv0, false));
SatSolver.addClause(s);
s.clear();
all.push(SATSolver::mkLit(nv0, true));
}
if (polary != LEFT_ONLY)
{
s.push(SATSolver::mkLit(v_a[i], true));
s.push(SATSolver::mkLit(v_b[i], false));
s.push(SATSolver::mkLit(result, true));
SatSolver.addClause(s);
s.clear();
s.push(SATSolver::mkLit(v_a[i], false));
s.push(SATSolver::mkLit(v_b[i], true));
s.push(SATSolver::mkLit(result, true));
SatSolver.addClause(s);
s.clear();
}
}
if (all.size() > 0)
{
all.push(SATSolver::mkLit(result, false));
SatSolver.addClause(all);
}
return result;
}
else if ((v_a.size() == 0) ^ (v_b.size() == 0))
{
ASTNode constant = a.isConstant() ? a : b;
vector<unsigned> vec = v_a.size() == 0 ? v_b : v_a;
assert(constant.isConstant());
assert(vec.size() == width);
SATSolver::vec_literals all;
const int result = SatSolver.newVar();
all.push(SATSolver::mkLit(result, false));
CBV v = constant.GetBVConst();
for (unsigned i = 0; i < width; i++)
{
if (polary != RIGHT_ONLY)
{
if (CONSTANTBV::BitVector_bit_test(v, i))
all.push(SATSolver::mkLit(vec[i], true));
else
all.push(SATSolver::mkLit(vec[i], false));
}
if (polary != LEFT_ONLY)
{
SATSolver::vec_literals p;
p.push(SATSolver::mkLit(result, true));
if (CONSTANTBV::BitVector_bit_test(v, i))
p.push(SATSolver::mkLit(vec[i], false));
else
p.push(SATSolver::mkLit(vec[i], true));
SatSolver.addClause(p);
}
}
if (all.size() > 1)
SatSolver.addClause(all);
return result;
}
else {
FatalError("Unexpected, both must be constants..");
exit(-1);
}
}
