Exemplo n.º 1
0
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);
}
Exemplo n.º 2
0
 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);
  }
}