void getSatVariables(const ASTNode& a, vector<unsigned>& v_a,
SATSolver& SatSolver, ToSATBase::ASTNodeToSATVar& satVar)
{
ToSATBase::ASTNodeToSATVar::iterator it = satVar.find(a);
if (it != satVar.end())
v_a = it->second;
else if (!a.isConstant())
{
assert(a.GetKind() == SYMBOL);
// It was ommitted from the initial problem, so assign it freshly.
for (unsigned i = 0; i < a.GetValueWidth(); i++)
{
uint32_t v = SatSolver.newVar();
// We probably don't want the variable eliminated.
SatSolver.setFrozen(v);
v_a.push_back(v);
}
satVar.insert(make_pair(a, v_a));
}
}
void ToCNFAIG::toCNF(const BBNodeAIG& top, Cnf_Dat_t*& cnfData,
ToSATBase::ASTNodeToSATVar& nodeToVar,
bool needAbsRef, BBNodeManagerAIG& mgr) {
assert(cnfData == NULL);
Aig_ObjCreatePo(mgr.aigMgr, top.n);
if (!needAbsRef) {
Aig_ManCleanup( mgr.aigMgr); // remove nodes not connected to the PO.
}
Aig_ManCheck( mgr.aigMgr); // check that AIG looks ok.
assert(Aig_ManPoNum(mgr.aigMgr) == 1);
// UseZeroes gives assertion errors.
// Rewriting is sometimes very slow. Can it be configured to be faster?
// What about refactoring???
int nodeCount = mgr.aigMgr->nObjs[AIG_OBJ_AND];
if (uf.stats_flag)
cerr << "Nodes before AIG rewrite:" << nodeCount << endl;
if (!needAbsRef && uf.isSet("aig-rewrite","0")) {
Dar_LibStart();
Aig_Man_t * pTemp;
Dar_RwrPar_t Pars, *pPars = &Pars;
Dar_ManDefaultRwrParams(pPars);
// Assertion errors occur with this enabled.
// pPars->fUseZeros = 1;
// For mul63bit.smt2 with iterations =3 & nCutsMax = 8
// CNF generation was taking 139 seconds, solving 10 seconds.
// With nCutsMax =2, CNF generation takes 16 seconds, solving 10 seconds.
// The rewriting doesn't remove as many nodes of course..
int iterations = 3;
for (int i = 0; i < iterations; i++) {
mgr.aigMgr = Aig_ManDup(pTemp = mgr.aigMgr, 0);
Aig_ManStop(pTemp);
Dar_ManRewrite(mgr.aigMgr, pPars);
mgr.aigMgr = Aig_ManDup(pTemp = mgr.aigMgr, 0);
Aig_ManStop(pTemp);
if (uf.stats_flag)
cerr << "After rewrite [" << i << "] nodes:"
<< mgr.aigMgr->nObjs[AIG_OBJ_AND] << endl;
if (nodeCount == mgr.aigMgr->nObjs[AIG_OBJ_AND])
break;
}
}
if (!uf.isSet("simple-cnf","0")) {
cnfData = Cnf_Derive(mgr.aigMgr, 0);
if (uf.stats_flag)
cerr << "advanced CNF" << endl;
} else {
cnfData = Cnf_DeriveSimple(mgr.aigMgr, 0);
if (uf.stats_flag)
cerr << "simple CNF" << endl;
}
BBNodeManagerAIG::SymbolToBBNode::const_iterator it;
assert(nodeToVar.size() == 0);
//todo. cf. with addvariables above...
// Each symbol maps to a vector of CNF variables.
for (it = mgr.symbolToBBNode.begin(); it != mgr.symbolToBBNode.end(); it++) {
const ASTNode& n = it->first;
const vector<BBNodeAIG> &b = it->second;
assert(nodeToVar.find(n) == nodeToVar.end());
const int width = (n.GetType() == BOOLEAN_TYPE) ? 1 : n.GetValueWidth();
// INT_MAX for parts of symbols that didn't get encoded.
vector<unsigned> v(width, ~((unsigned) 0));
for (unsigned i = 0; i < b.size(); i++) {
if (!b[i].IsNull()) {
Aig_Obj_t * pObj;
pObj = (Aig_Obj_t*) Vec_PtrEntry(mgr.aigMgr->vPis,
b[i].symbol_index);
v[i] = cnfData->pVarNums[pObj->Id];
}
}
nodeToVar.insert(make_pair(n, v));
}
assert(cnfData != NULL);
}