/**CFile****************************************************************

  FileName    [llb2Bad.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [BDD based reachability.]

  Synopsis    [Computing bad states.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

  Revision    [$Id: llb2Bad.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

***********************************************************************/

#include "llbInt.h"

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///                        DECLARATIONS                              ///
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///                     FUNCTION DEFINITIONS                         ///
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/**Function*************************************************************

  Synopsis    [Computes bad in working manager.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
DdNode * Llb_BddComputeBad( Aig_Man_t * pInit, DdManager * dd, abctime TimeOut )
{
    Vec_Ptr_t * vNodes;
    DdNode * bBdd0, * bBdd1, * bTemp, * bResult;
    Aig_Obj_t * pObj;
    int i, k;
    assert( Cudd_ReadSize(dd) == Aig_ManCiNum(pInit) );
    // initialize elementary variables
    Aig_ManConst1(pInit)->pData = Cudd_ReadOne( dd );
    Saig_ManForEachLo( pInit, pObj, i )
        pObj->pData = Cudd_bddIthVar( dd, i );
    Saig_ManForEachPi( pInit, pObj, i )
        pObj->pData = Cudd_bddIthVar( dd, Aig_ManRegNum(pInit) + i );
    // compute internal nodes
    vNodes = Aig_ManDfsNodes( pInit, (Aig_Obj_t **)Vec_PtrArray(pInit->vCos), Saig_ManPoNum(pInit) );
    Vec_PtrForEachEntry( Aig_Obj_t *, vNodes, pObj, i )
    {
        if ( !Aig_ObjIsNode(pObj) )
            continue;
        bBdd0 = Cudd_NotCond( (DdNode *)Aig_ObjFanin0(pObj)->pData, Aig_ObjFaninC0(pObj) );
        bBdd1 = Cudd_NotCond( (DdNode *)Aig_ObjFanin1(pObj)->pData, Aig_ObjFaninC1(pObj) );
//        pObj->pData = Extra_bddAndTime( dd, bBdd0, bBdd1, TimeOut );
        pObj->pData = Cudd_bddAnd( dd, bBdd0, bBdd1 );
        if ( pObj->pData == NULL )
        {
            Vec_PtrForEachEntryStop( Aig_Obj_t *, vNodes, pObj, k, i )
                if ( pObj->pData )
                    Cudd_RecursiveDeref( dd, (DdNode *)pObj->pData );
            Vec_PtrFree( vNodes );
            return NULL;
        }
        Cudd_Ref( (DdNode *)pObj->pData );
    }
    // quantify PIs of each PO
    bResult = Cudd_ReadLogicZero( dd );  Cudd_Ref( bResult );
    Saig_ManForEachPo( pInit, pObj, i )
    {
        bBdd0   = Cudd_NotCond( Aig_ObjFanin0(pObj)->pData, Aig_ObjFaninC0(pObj) );
        bResult = Cudd_bddOr( dd, bTemp = bResult, bBdd0 );     Cudd_Ref( bResult );
        Cudd_RecursiveDeref( dd, bTemp );
    }
    // deref
    Vec_PtrForEachEntry( Aig_Obj_t *, vNodes, pObj, i )
    {
        if ( !Aig_ObjIsNode(pObj) )
            continue;
        Cudd_RecursiveDeref( dd, (DdNode *)pObj->pData );
    }
    Vec_PtrFree( vNodes );
    Cudd_Deref( bResult );
    return bResult;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
DdNode * Llb_BddQuantifyPis( Aig_Man_t * pInit, DdManager * dd, DdNode * bFunc )
{
    DdNode * bVar, * bCube, * bTemp;
    Aig_Obj_t * pObj;
    int i;
    abctime TimeStop;
    assert( Cudd_ReadSize(dd) == Aig_ManCiNum(pInit) );
    TimeStop = dd->TimeStop; dd->TimeStop = 0;
    // create PI cube
    bCube = Cudd_ReadOne( dd );  Cudd_Ref( bCube );
    Saig_ManForEachPi( pInit, pObj, i )    {
        bVar  = Cudd_bddIthVar( dd, Aig_ManRegNum(pInit) + i );
        bCube = Cudd_bddAnd( dd, bTemp = bCube, bVar );  Cudd_Ref( bCube );
        Cudd_RecursiveDeref( dd, bTemp );
    }
    // quantify PI cube
    bFunc = Cudd_bddExistAbstract( dd, bFunc, bCube );  Cudd_Ref( bFunc );
    Cudd_RecursiveDeref( dd, bCube );
    Cudd_Deref( bFunc );
    dd->TimeStop = TimeStop;
    return bFunc;
}

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///                       END OF FILE                                ///
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