ABC_NAMESPACE_IMPL_START


////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Performs one iteration of AIG rewriting.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManRewriteDefault( Aig_Man_t * pAig )
{
    Aig_Man_t * pTemp;
    Dar_RwrPar_t Pars, * pPars = &Pars;
    Dar_ManDefaultRwrParams( pPars );
    pAig = Aig_ManDupDfs( pAig ); 
    Dar_ManRewrite( pAig, pPars );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    return pAig;
}
/**Function*************************************************************

  Synopsis    [Reproduces script "compress".]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_NewCompress( Aig_Man_t * pAig, int fBalance, int fUpdateLevel, int fPower, int fVerbose )
//alias compress2   "b -l; rw -l; rwz -l; b -l; rwz -l; b -l"
{
    Aig_Man_t * pTemp;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = fUpdateLevel;
    pParsRef->fUpdateLevel = fUpdateLevel;

    pParsRwr->fPower = fPower;

    pParsRwr->fVerbose = 0;//fVerbose;
    pParsRef->fVerbose = 0;//fVerbose;

//    pAig = Aig_ManDupDfs( pAig ); 
    if ( fVerbose ) printf( "Starting:  " ), Aig_ManPrintStats( pAig );

    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Refactor:  " ), Aig_ManPrintStats( pAig );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }

    pParsRwr->fUseZeros = 1;
    pParsRef->fUseZeros = 1;
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RewriteZ:  " ), Aig_ManPrintStats( pAig );

    return pAig;
}
/**Function*************************************************************

  Synopsis    [Performs one iteration of AIG rewriting.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManRewriteDefault( Aig_Man_t * pAig )
{
    Aig_Man_t * pTemp;
    Dar_RwrPar_t Pars, * pPars = &Pars;
    Dar_ManDefaultRwrParams( pPars );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );
    Dar_ManRewrite( pAig, pPars );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );
    return pAig;
}
/**Function*************************************************************

  Synopsis    [Reproduces script "compress2".]

  Description []
               
  SideEffects [This procedure does not tighten level during restructuring.]

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManRwsat( Aig_Man_t * pAig, int fBalance, int fVerbose )
//alias rwsat       "st; rw -l; b -l; rw -l; rf -l"
{
    Aig_Man_t * pTemp;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = 0;
    pParsRef->fUpdateLevel = 0;

    pParsRwr->fVerbose = fVerbose;
    pParsRef->fVerbose = fVerbose;
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, 0 );
    Aig_ManStop( pTemp );
    }
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    return pAig;
}
/**Function*************************************************************

  Synopsis    [Reproduces script "rwsat".]

  Description []
               
  SideEffects [This procedure does not tighten level during restructuring.]

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManRwsat( Aig_Man_t * pAig, int fBalance, int fVerbose )
//alias rwsat       "st; rw -l; b -l; rw -l; rf -l"
{
    Aig_Man_t * pTemp;
    abctime Time = pAig->Time2Quit;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = 0;
    pParsRef->fUpdateLevel = 0;

    pParsRwr->fVerbose = fVerbose;
    pParsRef->fVerbose = fVerbose;
//printf( "1" );
    pAig = Aig_ManDupDfs( pAig ); 
    if ( fVerbose ) printf( "Starting:  " ), Aig_ManPrintStats( pAig );

//printf( "2" );
    // balance
    if ( fBalance )
    {
    pAig->Time2Quit = Time;
    pAig = Dar_ManBalance( pTemp = pAig, 0 );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    if ( Time && Abc_Clock() > Time )
        { if ( pAig ) Aig_ManStop( pAig ); return NULL; }
    }
   
//Aig_ManDumpBlif( pAig, "inter.blif", NULL, NULL );
//printf( "3" );
    // rewrite
    pAig->Time2Quit = Time;
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    if ( Time && Abc_Clock() > Time )
        { if ( pAig ) Aig_ManStop( pAig ); return NULL; }

//printf( "4" );
    // refactor
    pAig->Time2Quit = Time;
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Refactor:  " ), Aig_ManPrintStats( pAig );
    if ( Time && Abc_Clock() > Time )
        { if ( pAig ) Aig_ManStop( pAig ); return NULL; }

//printf( "5" );
    // balance
    if ( fBalance )
    {
    pAig->Time2Quit = Time;
    pAig = Dar_ManBalance( pTemp = pAig, 0 );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    if ( Time && Abc_Clock() > Time )
        { if ( pAig ) Aig_ManStop( pAig ); return NULL; }
    }

//printf( "6" );
    // rewrite
    pAig->Time2Quit = Time;
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    if ( Time && Abc_Clock() > Time )
        { if ( pAig ) Aig_ManStop( pAig ); return NULL; }

//printf( "7" );
    return pAig;
}
/**Function*************************************************************

  Synopsis    [Reproduces script "compress2".]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_NewCompress2( Aig_Man_t * pAig, int fBalance, int fUpdateLevel, int fFanout, int fPower, int fLightSynth, int fVerbose )
//alias compress2   "b -l; rw -l; rf -l; b -l; rw -l; rwz -l; b -l; rfz -l; rwz -l; b -l"
{
    Aig_Man_t * pTemp;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = fUpdateLevel;
    pParsRef->fUpdateLevel = fUpdateLevel;
    pParsRwr->fFanout = fFanout;
    pParsRwr->fPower = fPower;

    pParsRwr->fVerbose = 0;//fVerbose;
    pParsRef->fVerbose = 0;//fVerbose;

//    pAig = Aig_ManDupDfs( pAig ); 
    if ( fVerbose ) printf( "Starting:  " ), Aig_ManPrintStats( pAig );

    // skip if lighter synthesis is requested
    if ( !fLightSynth )
    {
        // rewrite
        //Dar_ManRewrite( pAig, pParsRwr );
//        pParsRwr->fUpdateLevel = 0;  // disable level update  // this change was requested in July and later disabled
        Dar_ManRewrite( pAig, pParsRwr );
//        pParsRwr->fUpdateLevel = fUpdateLevel;  // reenable level update if needed

        pAig = Aig_ManDupDfs( pTemp = pAig ); 
        Aig_ManStop( pTemp );
        if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    
        // refactor
        Dar_ManRefactor( pAig, pParsRef );
        pAig = Aig_ManDupDfs( pTemp = pAig ); 
        Aig_ManStop( pTemp );
        if ( fVerbose ) printf( "Refactor:  " ), Aig_ManPrintStats( pAig );
    }

    // balance
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    
    // skip if lighter synthesis is requested
    if ( !fLightSynth )
    {
        // rewrite
        Dar_ManRewrite( pAig, pParsRwr );
        pAig = Aig_ManDupDfs( pTemp = pAig ); 
        Aig_ManStop( pTemp );
        if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    }

    pParsRwr->fUseZeros = 1;
    pParsRef->fUseZeros = 1;
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RewriteZ:  " ), Aig_ManPrintStats( pAig );

    // skip if lighter synthesis is requested
    if ( !fLightSynth )
    {
        // balance
        if ( fBalance )
        {
        pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
        Aig_ManStop( pTemp );
        if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
        }
    }
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RefactorZ: " ), Aig_ManPrintStats( pAig );
    
    // skip if lighter synthesis is requested
    if ( !fLightSynth )
    {
        // rewrite
        Dar_ManRewrite( pAig, pParsRwr );
        pAig = Aig_ManDupDfs( pTemp = pAig ); 
        Aig_ManStop( pTemp );
        if ( fVerbose ) printf( "RewriteZ:  " ), Aig_ManPrintStats( pAig );
    }

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }
    return pAig;
}
/**Function*************************************************************

  Synopsis    [Reproduces script "compress2".]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManCompress2( Aig_Man_t * pAig, int fBalance, int fUpdateLevel, int fFanout, int fPower, int fVerbose )
//alias compress2   "b -l; rw -l; rf -l; b -l; rw -l; rwz -l; b -l; rfz -l; rwz -l; b -l"
{
    Aig_Man_t * pTemp;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = fUpdateLevel;
    pParsRef->fUpdateLevel = fUpdateLevel;
    pParsRwr->fFanout = fFanout;
    pParsRwr->fPower = fPower;

    pParsRwr->fVerbose = 0;//fVerbose;
    pParsRef->fVerbose = 0;//fVerbose;

    pAig = Aig_ManDupDfs( pAig ); 
    if ( fVerbose ) printf( "Starting:  " ), Aig_ManPrintStats( pAig );
/*
    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }
*/
    // rewrite
//    Dar_ManRewrite( pAig, pParsRwr );
    pParsRwr->fUpdateLevel = 0;  // disable level update
    Dar_ManRewrite( pAig, pParsRwr );
    pParsRwr->fUpdateLevel = fUpdateLevel;  // reenable level update if needed

    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Refactor:  " ), Aig_ManPrintStats( pAig );

    // balance
//    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Rewrite:   " ), Aig_ManPrintStats( pAig );

    pParsRwr->fUseZeros = 1;
    pParsRef->fUseZeros = 1;
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RewriteZ:  " ), Aig_ManPrintStats( pAig );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RefactorZ: " ), Aig_ManPrintStats( pAig );
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDupDfs( pTemp = pAig ); 
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "RewriteZ:  " ), Aig_ManPrintStats( pAig );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    if ( fVerbose ) printf( "Balance:   " ), Aig_ManPrintStats( pAig );
    }
    return pAig;
}
Example #8
0
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);
}
/**Function*************************************************************

  Synopsis    [Reproduces script "compress2".]

  Description []
               
  SideEffects [This procedure does not tighten level during restructuring.]

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManCompress2( Aig_Man_t * pAig, int fBalance, int fUpdateLevel, int fVerbose )
//alias compress2   "b -l; rw -l; rf -l; b -l; rw -l; rwz -l; b -l; rfz -l; rwz -l; b -l"
{
    Aig_Man_t * pTemp;

    Dar_RwrPar_t ParsRwr, * pParsRwr = &ParsRwr;
    Dar_RefPar_t ParsRef, * pParsRef = &ParsRef;

    Dar_ManDefaultRwrParams( pParsRwr );
    Dar_ManDefaultRefParams( pParsRef );

    pParsRwr->fUpdateLevel = fUpdateLevel;
    pParsRef->fUpdateLevel = fUpdateLevel;

    pParsRwr->fVerbose = fVerbose;
    pParsRef->fVerbose = fVerbose;

    // balance
    if ( fBalance )
    {
//    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
//    Aig_ManStop( pTemp );
    }
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    // balance
//    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    }
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    pParsRwr->fUseZeros = 1;
    pParsRef->fUseZeros = 1;
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    }
    
    // refactor
    Dar_ManRefactor( pAig, pParsRef );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );
    
    // rewrite
    Dar_ManRewrite( pAig, pParsRwr );
    pAig = Aig_ManDup( pTemp = pAig, 0 ); 
    Aig_ManStop( pTemp );

    // balance
    if ( fBalance )
    {
    pAig = Dar_ManBalance( pTemp = pAig, fUpdateLevel );
    Aig_ManStop( pTemp );
    }
    return pAig;
}