giaCSatP.c

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

  FileName    [giaCSat.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Scalable AIG package.]

  Synopsis    [A simple circuit-based solver.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "gia.h"
#include "giaCSatP.h"

ABC_NAMESPACE_IMPL_START


//#define gia_assert(exp)     ((void)0)
//#define gia_assert(exp)     (assert(exp))

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


static inline int   CbsP_VarIsAssigned( Gia_Obj_t * pVar )      { return pVar->fMark0;                        }
static inline void  CbsP_VarAssign( Gia_Obj_t * pVar )          { assert(!pVar->fMark0); pVar->fMark0 = 1;    }
static inline void  CbsP_VarUnassign( CbsP_Man_t * pMan, Gia_Obj_t * pVar )        { assert(pVar->fMark0);  pVar->fMark0 = 0; pVar->fMark1 = 0; pMan->vValue->pArray[Gia_ObjId(pMan->pAig,pVar)] = ~0; }
static inline int   CbsP_VarValue( Gia_Obj_t * pVar )           { assert(pVar->fMark0);  return pVar->fMark1; }
static inline void  CbsP_VarSetValue( Gia_Obj_t * pVar, int v ) { assert(pVar->fMark0);  pVar->fMark1 = v;    }
static inline int   CbsP_VarIsJust( Gia_Obj_t * pVar )          { return Gia_ObjIsAnd(pVar) && !CbsP_VarIsAssigned(Gia_ObjFanin0(pVar)) && !CbsP_VarIsAssigned(Gia_ObjFanin1(pVar)); } 
static inline int   CbsP_VarFanin0Value( Gia_Obj_t * pVar )     { return !CbsP_VarIsAssigned(Gia_ObjFanin0(pVar)) ? 2 : (CbsP_VarValue(Gia_ObjFanin0(pVar)) ^ Gia_ObjFaninC0(pVar)); }
static inline int   CbsP_VarFanin1Value( Gia_Obj_t * pVar )     { return !CbsP_VarIsAssigned(Gia_ObjFanin1(pVar)) ? 2 : (CbsP_VarValue(Gia_ObjFanin1(pVar)) ^ Gia_ObjFaninC1(pVar)); }

static inline int         CbsP_VarDecLevel( CbsP_Man_t * p, Gia_Obj_t * pVar )  { int Value = p->vValue->pArray[Gia_ObjId(p->pAig,pVar)]; assert( Value != ~0 ); return Vec_IntEntry(p->vLevReas, 3*Value);          }
static inline Gia_Obj_t * CbsP_VarReason0( CbsP_Man_t * p, Gia_Obj_t * pVar )   { int Value = p->vValue->pArray[Gia_ObjId(p->pAig,pVar)]; assert( Value != ~0 ); return pVar + Vec_IntEntry(p->vLevReas, 3*Value+1); }
static inline Gia_Obj_t * CbsP_VarReason1( CbsP_Man_t * p, Gia_Obj_t * pVar )   { int Value = p->vValue->pArray[Gia_ObjId(p->pAig,pVar)]; assert( Value != ~0 ); return pVar + Vec_IntEntry(p->vLevReas, 3*Value+2); }
static inline int         CbsP_ClauseDecLevel( CbsP_Man_t * p, int hClause )    { return CbsP_VarDecLevel( p, p->pClauses.pData[hClause] );                               }

#define CbsP_QueForEachEntry( Que, pObj, i )                         \
    for ( i = (Que).iHead; (i < (Que).iTail) && ((pObj) = (Que).pData[i]); i++ )

#define CbsP_ClauseForEachVar( p, hClause, pObj )                    \
    for ( (p)->pIter = (p)->pClauses.pData + hClause; (pObj = *pIter); (p)->pIter++ )
#define CbsP_ClauseForEachVar1( p, hClause, pObj )                   \
    for ( (p)->pIter = (p)->pClauses.pData+hClause+1; (pObj = *pIter); (p)->pIter++ )

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

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

  Synopsis    [Sets default values of the parameters.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void CbsP_SetDefaultParams( CbsP_Par_t * pPars )
{
    memset( pPars, 0, sizeof(CbsP_Par_t) );
    pPars->nBTLimit    =  1000;   // limit on the number of conflicts
    pPars->nJustLimit  =   100;   // limit on the size of justification queue
    pPars->fUseHighest =     1;   // use node with the highest ID
    pPars->fUseLowest  =     0;   // use node with the highest ID
    pPars->fUseMaxFF   =     0;   // use node with the largest fanin fanout
    pPars->fVerbose    =     1;   // print detailed statistics

    pPars->fUseProved  =     1;


    pPars->nJscanThis     = 0;
    pPars->nRscanThis     = 0;
    pPars->maxJscanUndec  = 0;
    pPars->maxRscanUndec  = 0;
    pPars->maxJscanSolved = 0;
    pPars->maxRscanSolved = 0;


    pPars->accJscanSat    = 0;
    pPars->accJscanUnsat  = 0;
    pPars->accJscanUndec  = 0;
    pPars->accRscanSat    = 0;
    pPars->accRscanUnsat  = 0;
    pPars->accRscanUndec  = 0;
    pPars->nSat    = 0;
    pPars->nUnsat  = 0;
    pPars->nUndec  = 0;

    pPars->nJscanLimit    = 100;
    pPars->nRscanLimit    = 100;
    pPars->nPropLimit     = 500;
}
void CbsP_ManSetConflictNum( CbsP_Man_t * p, int Num )
{
    p->Pars.nBTLimit = Num;
}

static inline void CbsP_UpdateRecord( CbsP_Par_t * pPars, int res ){
    if( CBS_UNDEC == res ){
        pPars->nUndec ++ ;
        if( pPars-> maxJscanUndec < pPars->nJscanThis )
            pPars-> maxJscanUndec = pPars->nJscanThis; 
        if( pPars-> maxRscanUndec < pPars->nRscanThis )
            pPars-> maxRscanUndec = pPars->nRscanThis; 
        if( pPars->  maxPropUndec < pPars->nPropThis )
            pPars->  maxPropUndec = pPars->nPropThis; 

        pPars->accJscanUndec     += pPars->nJscanThis;
        pPars->accRscanUndec     += pPars->nRscanThis;
        pPars-> accPropUndec     += pPars->nPropThis;
    } else {
        if( pPars->maxJscanSolved < pPars->nJscanThis )
            pPars->maxJscanSolved = pPars->nJscanThis; 
        if( pPars->maxRscanSolved < pPars->nRscanThis )
            pPars->maxRscanSolved = pPars->nRscanThis; 
        if( pPars-> maxPropSolved < pPars->nPropThis )
            pPars-> maxPropSolved = pPars->nPropThis; 
        if( CBS_SAT == res ){
            pPars->nSat ++ ;
            pPars->accJscanSat   += pPars->nJscanThis;
            pPars->accRscanSat   += pPars->nRscanThis;
            pPars-> accPropSat   += pPars->nPropThis;
        } else
        if( CBS_UNSAT == res ){
            pPars->nUnsat ++ ;
            pPars->accJscanUnsat += pPars->nJscanThis;
            pPars->accRscanUnsat += pPars->nRscanThis;
            pPars-> accPropUnsat += pPars->nPropThis;
        }
    }

}

void CbsP_PrintRecord( CbsP_Par_t * pPars ){
    printf("max of solved: jscan# %13d rscan %13d prop %13d\n"   , pPars->maxJscanSolved, pPars->maxRscanSolved , pPars->maxPropSolved );
    printf("max of  undec: jscan# %13d rscan %13d prop %13d\n"   , pPars->maxJscanUndec , pPars->maxRscanUndec  , pPars->maxPropUndec  );
    printf("acc of    sat: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanSat   , pPars->accRscanSat    , pPars->accPropSat    );
    printf("acc of  unsat: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanUnsat , pPars->accRscanUnsat  , pPars->accPropUnsat  );
    printf("acc of  undec: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanUndec , pPars->accRscanUndec  , pPars->accPropUndec  );
    if( pPars->nSat )
        printf("avg of    sat: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanSat   / pPars->nSat   , pPars->accRscanSat   / pPars->nSat   , pPars->accPropSat   / pPars->nSat   );
    if( pPars->nUnsat )
        printf("avg of  unsat: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanUnsat / pPars->nUnsat , pPars->accRscanUnsat / pPars->nUnsat , pPars->accPropUnsat / pPars->nUnsat );
    if( pPars->nUndec )
        printf("avg of  undec: jscan# %13ld rscan %13ld prop %13ld\n", pPars->accJscanUndec / pPars->nUndec , pPars->accRscanUndec / pPars->nUndec , pPars->accPropUndec / pPars->nUndec );
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
CbsP_Man_t * CbsP_ManAlloc( Gia_Man_t * pGia )
{
    CbsP_Man_t * p;
    p = ABC_CALLOC( CbsP_Man_t, 1 );
    p->pProp.nSize = p->pJust.nSize = p->pClauses.nSize = 10000;
    p->pProp.pData = ABC_ALLOC( Gia_Obj_t *, p->pProp.nSize );
    p->pJust.pData = ABC_ALLOC( Gia_Obj_t *, p->pJust.nSize );
    p->pClauses.pData = ABC_ALLOC( Gia_Obj_t *, p->pClauses.nSize );
    p->pClauses.iHead = p->pClauses.iTail = 1;
    p->vModel   = Vec_IntAlloc( 1000 );
    p->vLevReas = Vec_IntAlloc( 1000 );
    p->vTemp    = Vec_PtrAlloc( 1000 );
    p->pAig     = pGia;
    p->vValue   = Vec_IntAlloc( Gia_ManObjNum(pGia) );
    Vec_IntFill( p->vValue, Gia_ManObjNum(pGia), ~0 );
    //memset( p->vValue->pArray, (unsigned) ~0, sizeof(int) * Gia_ManObjNum(pGia) );
    CbsP_SetDefaultParams( &p->Pars );
    return p;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void CbsP_ManStop( CbsP_Man_t * p )
{
    Vec_IntFree( p->vLevReas );
    Vec_IntFree( p->vModel );
    Vec_PtrFree( p->vTemp );
    Vec_IntFree( p->vValue );
    ABC_FREE( p->pClauses.pData );
    ABC_FREE( p->pProp.pData );
    ABC_FREE( p->pJust.pData );
    ABC_FREE( p );
}

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

  Synopsis    [Returns satisfying assignment.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Int_t * CbsP_ReadModel( CbsP_Man_t * p )
{
    return p->vModel;
}




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

  Synopsis    [Returns 1 if the solver is out of limits.]

  Description []
               
  SideEffects []

  SeeAlso     []

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

static inline int CbsP_ManCheckPropLimits( CbsP_Man_t * p )
{
    return p->Pars.nPropThis > p->Pars.nPropLimit;
}
static inline int CbsP_ManCheckLimits( CbsP_Man_t * p )
{
    return CbsP_ManCheckPropLimits(p) || p->Pars.nJscanThis > p->Pars.nJscanLimit || p->Pars.nRscanThis > p->Pars.nRscanLimit || p->Pars.nJustThis > p->Pars.nJustLimit || p->Pars.nBTThis > p->Pars.nBTLimit;
}

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

  Synopsis    [Saves the satisfying assignment as an array of literals.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManSaveModel( CbsP_Man_t * p, Vec_Int_t * vCex )
{
    Gia_Obj_t * pVar;
    int i;
    Vec_IntClear( vCex );
    p->pProp.iHead = 0;
    CbsP_QueForEachEntry( p->pProp, pVar, i )
        if ( Gia_ObjIsCi(pVar) )
            Vec_IntPush( vCex, Abc_Var2Lit(Gia_ObjId(p->pAig,pVar), !CbsP_VarValue(pVar)) );
//            Vec_IntPush( vCex, Abc_Var2Lit(Gia_ObjCioId(pVar), !CbsP_VarValue(pVar)) );
} 
static inline void CbsP_ManSaveModelAll( CbsP_Man_t * p, Vec_Int_t * vCex )
{
    Gia_Obj_t * pVar;
    int i;
    Vec_IntClear( vCex );
    p->pProp.iHead = 0;
    CbsP_QueForEachEntry( p->pProp, pVar, i )
        Vec_IntPush( vCex, Abc_Var2Lit(Gia_ObjId(p->pAig,pVar), !CbsP_VarValue(pVar)) );
} 

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_QueIsEmpty( CbsP_Que_t * p )
{
    return p->iHead == p->iTail;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_QuePush( CbsP_Que_t * p, Gia_Obj_t * pObj )
{
    assert( !Gia_IsComplement(pObj) );
    if ( p->iTail == p->nSize )
    {
        p->nSize *= 2;
        p->pData = ABC_REALLOC( Gia_Obj_t *, p->pData, p->nSize ); 
    }
    p->pData[p->iTail++] = pObj;
}

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

  Synopsis    [Returns 1 if the object in the queue.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_QueHasNode( CbsP_Que_t * p, Gia_Obj_t * pObj )
{
    Gia_Obj_t * pTemp;
    int i;
    CbsP_QueForEachEntry( *p, pTemp, i )
        if ( pTemp == pObj )
            return 1;
    return 0;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_QueStore( CbsP_Que_t * p, int * piHeadOld, int * piTailOld )
{
    int i;
    *piHeadOld = p->iHead;
    *piTailOld = p->iTail;
    for ( i = *piHeadOld; i < *piTailOld; i++ )
        CbsP_QuePush( p, p->pData[i] );
    p->iHead = *piTailOld;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_QueRestore( CbsP_Que_t * p, int iHeadOld, int iTailOld )
{
    p->iHead = iHeadOld;
    p->iTail = iTailOld;
}

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

  Synopsis    [Finalized the clause.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_QueFinish( CbsP_Que_t * p )
{
    int iHeadOld = p->iHead;
    assert( p->iHead < p->iTail );
    CbsP_QuePush( p, NULL );
    p->iHead = p->iTail;
    return iHeadOld;
}


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

  Synopsis    [Max number of fanins fanouts.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_VarFaninFanoutMax( CbsP_Man_t * p, Gia_Obj_t * pObj )
{
    int Count0, Count1;
    assert( !Gia_IsComplement(pObj) );
    assert( Gia_ObjIsAnd(pObj) );
    Count0 = Gia_ObjRefNum( p->pAig, Gia_ObjFanin0(pObj) );
    Count1 = Gia_ObjRefNum( p->pAig, Gia_ObjFanin1(pObj) );
    return Abc_MaxInt( Count0, Count1 );
}

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

  Synopsis    [Find variable with the highest ID.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline Gia_Obj_t * CbsP_ManDecideHighest( CbsP_Man_t * p )
{
    Gia_Obj_t * pObj, * pObjMax = NULL;
    int i;
    CbsP_QueForEachEntry( p->pJust, pObj, i )
        if ( pObjMax == NULL || pObjMax < pObj )
            pObjMax = pObj;
    return pObjMax;
}

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

  Synopsis    [Find variable with the lowest ID.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline Gia_Obj_t * CbsP_ManDecideLowest( CbsP_Man_t * p )
{
    Gia_Obj_t * pObj, * pObjMin = NULL;
    int i;
    CbsP_QueForEachEntry( p->pJust, pObj, i )
        if ( pObjMin == NULL || pObjMin > pObj )
            pObjMin = pObj;
    return pObjMin;
}

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

  Synopsis    [Find variable with the maximum number of fanin fanouts.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline Gia_Obj_t * CbsP_ManDecideMaxFF( CbsP_Man_t * p )
{
    Gia_Obj_t * pObj, * pObjMax = NULL;
    int i, iMaxFF = 0, iCurFF;
    assert( p->pAig->pRefs != NULL );
    CbsP_QueForEachEntry( p->pJust, pObj, i )
    {
        iCurFF = CbsP_VarFaninFanoutMax( p, pObj );
        assert( iCurFF > 0 );
        if ( iMaxFF < iCurFF )
        {
            iMaxFF = iCurFF;
            pObjMax = pObj;
        }
    }
    return pObjMax; 
}



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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManCancelUntil( CbsP_Man_t * p, int iBound )
{
    Gia_Obj_t * pVar;
    int i;
    assert( iBound <= p->pProp.iTail );
    p->pProp.iHead = iBound;
    CbsP_QueForEachEntry( p->pProp, pVar, i )
        CbsP_VarUnassign( p, pVar );
    p->pProp.iTail = iBound;
    Vec_IntShrink( p->vLevReas, 3*iBound );
}

//int s_Counter = 0;

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

  Synopsis    [Assigns the variables a value.]

  Description [Returns 1 if conflict; 0 if no conflict.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManAssign( CbsP_Man_t * p, Gia_Obj_t * pObj, int Level, Gia_Obj_t * pRes0, Gia_Obj_t * pRes1 )
{
    Gia_Obj_t * pObjR = Gia_Regular(pObj);
    assert( Gia_ObjIsCand(pObjR) );
    assert( !CbsP_VarIsAssigned(pObjR) );
    CbsP_VarAssign( pObjR );
    CbsP_VarSetValue( pObjR, !Gia_IsComplement(pObj) );
    assert( p->vValue->pArray[Gia_ObjId(p->pAig,pObjR)] == ~0 );
    p->vValue->pArray[Gia_ObjId(p->pAig,pObjR)] = p->pProp.iTail;
    CbsP_QuePush( &p->pProp, pObjR );
    Vec_IntPush( p->vLevReas, Level );
    Vec_IntPush( p->vLevReas, pRes0 ? pRes0-pObjR : 0 );
    Vec_IntPush( p->vLevReas, pRes1 ? pRes1-pObjR : 0 );
    assert( Vec_IntSize(p->vLevReas) == 3 * p->pProp.iTail );
    if( pRes0 )
        p->Pars.nPropThis ++ ;
//    s_Counter++;
//    s_Counter = Abc_MaxIntInt( s_Counter, Vec_IntSize(p->vLevReas)/3 );
}


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

  Synopsis    [Returns clause size.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_ManClauseSize( CbsP_Man_t * p, int hClause )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t ** pIter;
    for ( pIter = pQue->pData + hClause; *pIter; pIter++ );
    return pIter - pQue->pData - hClause ;
}

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

  Synopsis    [Prints conflict clause.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManPrintClause( CbsP_Man_t * p, int Level, int hClause )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t * pObj;
    int i;
    assert( CbsP_QueIsEmpty( pQue ) );
    printf( "Level %2d : ", Level );
    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
        printf( "%d=%d(%d) ", Gia_ObjId(p->pAig, pObj), CbsP_VarValue(pObj), CbsP_VarDecLevel(p, pObj) );
    printf( "\n" );
}

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

  Synopsis    [Prints conflict clause.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManPrintClauseNew( CbsP_Man_t * p, int Level, int hClause )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t * pObj;
    int i;
    assert( CbsP_QueIsEmpty( pQue ) );
    printf( "Level %2d : ", Level );
    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
        printf( "%c%d ", CbsP_VarValue(pObj)? '+':'-', Gia_ObjId(p->pAig, pObj) );
    printf( "\n" );
}

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

  Synopsis    [Returns conflict clause.]

  Description [Performs conflict analysis.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline void CbsP_ManDeriveReason( CbsP_Man_t * p, int Level )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t * pObj, * pReason;
    int i, k, iLitLevel;
    assert( pQue->pData[pQue->iHead] == NULL );
    assert( pQue->iHead + 1 < pQue->iTail );
/*
    for ( i = pQue->iHead + 1; i < pQue->iTail; i++ )
    {
        pObj = pQue->pData[i];
        assert( pObj->fMark0 == 1 );
    }
*/
    // compact literals
    Vec_PtrClear( p->vTemp );
    for ( i = k = pQue->iHead + 1; i < pQue->iTail; i++ )
    {
        pObj = pQue->pData[i];
        if ( !pObj->fMark0 ) // unassigned - seen again
            continue;
        // assigned - seen first time
        pObj->fMark0 = 0;
        Vec_PtrPush( p->vTemp, pObj );
        // check decision level
        iLitLevel = CbsP_VarDecLevel( p, pObj );
        if ( iLitLevel < Level )
        {
            pQue->pData[k++] = pObj;
            continue;
        }
        assert( iLitLevel == Level );
        pReason = CbsP_VarReason0( p, pObj );
        if ( pReason == pObj ) // no reason
        {
            //assert( pQue->pData[pQue->iHead] == NULL );
            pQue->pData[pQue->iHead] = pObj;
            continue;
        }
        CbsP_QuePush( pQue, pReason );
        pReason = CbsP_VarReason1( p, pObj );
        if ( pReason != pObj ) // second reason
            CbsP_QuePush( pQue, pReason );
    }
    assert( pQue->pData[pQue->iHead] != NULL );
    pQue->iTail = k;
    // clear the marks
    Vec_PtrForEachEntry( Gia_Obj_t *, p->vTemp, pObj, i )
        pObj->fMark0 = 1;
}

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

  Synopsis    [Returns conflict clause.]

  Description [Performs conflict analysis.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_ManAnalyze( CbsP_Man_t * p, int Level, Gia_Obj_t * pVar, Gia_Obj_t * pFan0, Gia_Obj_t * pFan1 )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    assert( CbsP_VarIsAssigned(pVar) );
    assert( CbsP_VarIsAssigned(pFan0) );
    assert( pFan1 == NULL || CbsP_VarIsAssigned(pFan1) );
    assert( CbsP_QueIsEmpty( pQue ) );
    CbsP_QuePush( pQue, NULL );
    CbsP_QuePush( pQue, pVar );
    CbsP_QuePush( pQue, pFan0 );
    if ( pFan1 )
        CbsP_QuePush( pQue, pFan1 );
    CbsP_ManDeriveReason( p, Level );
    return CbsP_QueFinish( pQue );
}


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

  Synopsis    [Performs resolution of two clauses.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_ManResolve( CbsP_Man_t * p, int Level, int hClause0, int hClause1 )
{
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t * pObj;
    int i, LevelMax = -1, LevelCur;
    assert( pQue->pData[hClause0] != NULL );
    assert( pQue->pData[hClause0] == pQue->pData[hClause1] );
/*
    for ( i = hClause0 + 1; (pObj = pQue->pData[i]); i++ )
        assert( pObj->fMark0 == 1 );
    for ( i = hClause1 + 1; (pObj = pQue->pData[i]); i++ )
        assert( pObj->fMark0 == 1 );
*/
    assert( CbsP_QueIsEmpty( pQue ) );
    CbsP_QuePush( pQue, NULL );
    for ( i = hClause0 + 1; (pObj = pQue->pData[i]); i++ )
    {
        if ( !pObj->fMark0 ) // unassigned - seen again
            continue;
        // assigned - seen first time
        pObj->fMark0 = 0;
        CbsP_QuePush( pQue, pObj );
        p->Pars.nRscanThis ++ ;
        LevelCur = CbsP_VarDecLevel( p, pObj );
        if ( LevelMax < LevelCur )
            LevelMax = LevelCur;
    }
    for ( i = hClause1 + 1; (pObj = pQue->pData[i]); i++ )
    {
        if ( !pObj->fMark0 ) // unassigned - seen again
            continue;
        // assigned - seen first time
        pObj->fMark0 = 0;
        CbsP_QuePush( pQue, pObj );
        p->Pars.nRscanThis ++ ;
        LevelCur = CbsP_VarDecLevel( p, pObj );
        if ( LevelMax < LevelCur )
            LevelMax = LevelCur;
    }
    for ( i = pQue->iHead + 1; i < pQue->iTail; i++ )
        pQue->pData[i]->fMark0 = 1;
    CbsP_ManDeriveReason( p, LevelMax );
    return CbsP_QueFinish( pQue );
}

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

  Synopsis    [Propagates a variable.]

  Description [Returns clause handle if conflict; 0 if no conflict.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_ManPropagateOne( CbsP_Man_t * p, Gia_Obj_t * pVar, int Level )
{
    int Value0, Value1;
    assert( !Gia_IsComplement(pVar) );
    assert( CbsP_VarIsAssigned(pVar) );
    if ( Gia_ObjIsCi(pVar) )
        return 0;
    assert( Gia_ObjIsAnd(pVar) );
    Value0 = CbsP_VarFanin0Value(pVar);
    Value1 = CbsP_VarFanin1Value(pVar);
    if ( CbsP_VarValue(pVar) )
    { // value is 1
        if ( Value0 == 0 || Value1 == 0 ) // one is 0
        {
            if ( Value0 == 0 && Value1 != 0 )
                return CbsP_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), NULL );
            if ( Value0 != 0 && Value1 == 0 )
                return CbsP_ManAnalyze( p, Level, pVar, Gia_ObjFanin1(pVar), NULL );
            assert( Value0 == 0 && Value1 == 0 );
            return CbsP_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
        }
        if ( Value0 == 2 ) // first is unassigned
            CbsP_ManAssign( p, Gia_ObjChild0(pVar), Level, pVar, NULL );
        if ( Value1 == 2 ) // first is unassigned
            CbsP_ManAssign( p, Gia_ObjChild1(pVar), Level, pVar, NULL );
        return 0;
    }
    // value is 0
    if ( Value0 == 0 || Value1 == 0 ) // one is 0
        return 0;
    if ( Value0 == 1 && Value1 == 1 ) // both are 1
        return CbsP_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
    if ( Value0 == 1 || Value1 == 1 ) // one is 1 
    {
        if ( Value0 == 2 ) // first is unassigned
            CbsP_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)), Level, pVar, Gia_ObjFanin1(pVar) );
        if ( Value1 == 2 ) // second is unassigned
            CbsP_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)), Level, pVar, Gia_ObjFanin0(pVar) );
        return 0;
    }
    assert( CbsP_VarIsJust(pVar) );
    assert( !CbsP_QueHasNode( &p->pJust, pVar ) );
    CbsP_QuePush( &p->pJust, pVar );
    return 0;
}

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

  Synopsis    [Propagates a variable.]

  Description [Returns 1 if conflict; 0 if no conflict.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int CbsP_ManPropagateTwo( CbsP_Man_t * p, Gia_Obj_t * pVar, int Level )
{
    int Value0, Value1;
    assert( !Gia_IsComplement(pVar) );
    assert( Gia_ObjIsAnd(pVar) );
    assert( CbsP_VarIsAssigned(pVar) );
    assert( !CbsP_VarValue(pVar) );
    Value0 = CbsP_VarFanin0Value(pVar);
    Value1 = CbsP_VarFanin1Value(pVar);
    // value is 0
    if ( Value0 == 0 || Value1 == 0 ) // one is 0
        return 0;
    if ( Value0 == 1 && Value1 == 1 ) // both are 1
        return CbsP_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
    assert( Value0 == 1 || Value1 == 1 );
    if ( Value0 == 2 ) // first is unassigned
        CbsP_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)), Level, pVar, Gia_ObjFanin1(pVar) );
    if ( Value1 == 2 ) // first is unassigned
        CbsP_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)), Level, pVar, Gia_ObjFanin0(pVar) );
    return 0;
}

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

  Synopsis    [Propagates all variables.]

  Description [Returns 1 if conflict; 0 if no conflict.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int CbsP_ManPropagate( CbsP_Man_t * p, int Level )
{
    int hClause;
    Gia_Obj_t * pVar;
    int i, k;
    while ( 1 )
    {
        CbsP_QueForEachEntry( p->pProp, pVar, i )
        {
            if ( (hClause = CbsP_ManPropagateOne( p, pVar, Level )) )
                return hClause;
            if( CbsP_ManCheckPropLimits(p) )
                return 0;
        }
        p->pProp.iHead = p->pProp.iTail;
        k = p->pJust.iHead;
        CbsP_QueForEachEntry( p->pJust, pVar, i )
        {
            if ( CbsP_VarIsJust( pVar ) )
                p->pJust.pData[k++] = pVar;
            else if ( (hClause = CbsP_ManPropagateTwo( p, pVar, Level )) )
                return hClause;
            if( CbsP_ManCheckPropLimits(p) )
                return 0;
        }
        if ( k == p->pJust.iTail )
            break;
        p->pJust.iTail = k;
    }
    return 0;
}

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

  Synopsis    [Solve the problem recursively.]

  Description [Returns learnt clause if unsat, NULL if sat or undecided.]
               
  SideEffects []

  SeeAlso     []
 
***********************************************************************/
int CbsP_ManSolve_rec( CbsP_Man_t * p, int Level )
{ 
    CbsP_Que_t * pQue = &(p->pClauses);
    Gia_Obj_t * pVar = NULL, * pDecVar;
    int hClause, hLearn0, hLearn1;
    int iPropHead, iJustHead, iJustTail;
    // propagate assignments
    assert( !CbsP_QueIsEmpty(&p->pProp) );
    if ( (hClause = CbsP_ManPropagate( p, Level )) )
        return hClause;
    
    // quit using resource limits
    if ( CbsP_ManCheckLimits( p ) )
        return 0;
    // check for satisfying assignment
    assert( CbsP_QueIsEmpty(&p->pProp) );
    if ( CbsP_QueIsEmpty(&p->pJust) )
        return 0;
    p->Pars.nJustThis = Abc_MaxInt( p->Pars.nJustThis, p->pJust.iTail - p->pJust.iHead );
    // remember the state before branching
    iPropHead = p->pProp.iHead;
    CbsP_QueStore( &p->pJust, &iJustHead, &iJustTail );
    p->Pars.nJscanThis += iJustTail - iJustHead;
    if ( CbsP_ManCheckLimits( p ) )
        return 0;
    // find the decision variable
    if ( p->Pars.fUseHighest )
        pVar = CbsP_ManDecideHighest( p );
    else if ( p->Pars.fUseLowest )
        pVar = CbsP_ManDecideLowest( p );
    else if ( p->Pars.fUseMaxFF )
        pVar = CbsP_ManDecideMaxFF( p );
    else assert( 0 );
    assert( CbsP_VarIsJust( pVar ) );
    // chose decision variable using fanout count

    if ( Gia_ObjRefNum(p->pAig, Gia_ObjFanin0(pVar)) > Gia_ObjRefNum(p->pAig, Gia_ObjFanin1(pVar)) )
        pDecVar = Gia_Not(Gia_ObjChild0(pVar));
    else
        pDecVar = Gia_Not(Gia_ObjChild1(pVar));
    
//    pDecVar = Gia_NotCond( Gia_Regular(pDecVar), Gia_Regular(pDecVar)->fPhase );
//    pDecVar = Gia_Not(pDecVar);
    // decide on first fanin
    CbsP_ManAssign( p, pDecVar, Level+1, NULL, NULL );
    if ( !(hLearn0 = CbsP_ManSolve_rec( p, Level+1 )) )
        return 0;
    if ( CbsP_ManCheckLimits( p ) )
        return 0;
    if ( pQue->pData[hLearn0] != Gia_Regular(pDecVar) )
        return hLearn0;
    CbsP_ManCancelUntil( p, iPropHead );
    CbsP_QueRestore( &p->pJust, iJustHead, iJustTail );
    // decide on second fanin
    CbsP_ManAssign( p, Gia_Not(pDecVar), Level+1, NULL, NULL );
    if ( !(hLearn1 = CbsP_ManSolve_rec( p, Level+1 )) )
        return 0;
    if ( CbsP_ManCheckLimits( p ) )
        return 0;
    if ( pQue->pData[hLearn1] != Gia_Regular(pDecVar) )
        return hLearn1;
    hClause = CbsP_ManResolve( p, Level, hLearn0, hLearn1 );
//    CbsP_ManPrintClauseNew( p, Level, hClause );
//    if ( Level > CbsP_ClauseDecLevel(p, hClause) )
//        p->Pars.nBTThisNc++;
    p->Pars.nBTThis++;
    return hClause;
}

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

  Synopsis    [Looking for a satisfying assignment of the node.]

  Description [Assumes that each node has flag pObj->fMark0 set to 0.
  Returns 1 if unsatisfiable, 0 if satisfiable, and -1 if undecided.
  The node may be complemented. ]
               
  SideEffects [The two procedures differ in the CEX format.]

  SeeAlso     []

***********************************************************************/
int CbsP_ManSolve( CbsP_Man_t * p, Gia_Obj_t * pObj )
{
    int RetValue = 0;
//    s_Counter = 0;
    assert( !p->pProp.iHead && !p->pProp.iTail );
    assert( !p->pJust.iHead && !p->pJust.iTail );
    assert( p->pClauses.iHead == 1 && p->pClauses.iTail == 1 );
    p->Pars.nBTThis = p->Pars.nJustThis = p->Pars.nBTThisNc = 0;
    CbsP_ManAssign( p, pObj, 0, NULL, NULL );
    if ( !CbsP_ManSolve_rec(p, 0) && !CbsP_ManCheckLimits(p) )
        CbsP_ManSaveModel( p, p->vModel );
    else
        RetValue = 1;
    CbsP_ManCancelUntil( p, 0 );
    p->pJust.iHead = p->pJust.iTail = 0;
    p->pClauses.iHead = p->pClauses.iTail = 1;
    p->Pars.nBTTotal += p->Pars.nBTThis;
    p->Pars.nJustTotal = Abc_MaxInt( p->Pars.nJustTotal, p->Pars.nJustThis );
    if ( CbsP_ManCheckLimits( p ) )
        RetValue = -1;
//    printf( "%d ", s_Counter );
    return RetValue;
}
int CbsP_ManSolve2( CbsP_Man_t * p, Gia_Obj_t * pObj, Gia_Obj_t * pObj2 )
{
    abctime clk = Abc_Clock();
    int RetValue = 0;
//    s_Counter = 0;
    assert( !p->pProp.iHead && !p->pProp.iTail );
    assert( !p->pJust.iHead && !p->pJust.iTail );
    assert( p->pClauses.iHead == 1 && p->pClauses.iTail == 1 );
    p->Pars.nBTThis = p->Pars.nJustThis = p->Pars.nBTThisNc = 0;
    p->Pars.nJscanThis = p->Pars.nRscanThis = p->Pars.nPropThis = 0;
    CbsP_ManAssign( p, pObj, 0, NULL, NULL );
    if ( pObj2 ) 
    CbsP_ManAssign( p, pObj2, 0, NULL, NULL );
    if ( !CbsP_ManSolve_rec(p, 0) && !CbsP_ManCheckLimits(p) )
        CbsP_ManSaveModel( p, p->vModel );
    else 
        RetValue = 1;
    CbsP_ManCancelUntil( p, 0 );

    p->pJust.iHead = p->pJust.iTail = 0;
    p->pClauses.iHead = p->pClauses.iTail = 1;
    p->Pars.nBTTotal += p->Pars.nBTThis;
    p->Pars.nJustTotal = Abc_MaxInt( p->Pars.nJustTotal, p->Pars.nJustThis );
    if ( CbsP_ManCheckLimits( p ) )
        RetValue = -1;

    if( CBS_SAT == RetValue ){
        p->nSatSat ++;
        p->timeSatSat   += Abc_Clock() - clk;
        p->nConfSat     += p->Pars.nBTThis;
    } else
    if( CBS_UNSAT == RetValue ){
        p->nSatUnsat ++;
        p->timeSatUnsat += Abc_Clock() - clk;
        p->nConfUnsat   += p->Pars.nBTThis;
    } else {
        p->nSatUndec ++;
        p->timeSatUndec += Abc_Clock() - clk;
        p->nConfUndec   += p->Pars.nBTThis;
    }
//    printf( "%d ", s_Counter );
    CbsP_UpdateRecord(&p->Pars,RetValue);
    return RetValue;
}

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

  Synopsis    [Prints statistics of the manager.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void CbsP_ManSatPrintStats( CbsP_Man_t * p )
{
    printf( "CO = %8d  ", Gia_ManCoNum(p->pAig) );
    printf( "AND = %8d  ", Gia_ManAndNum(p->pAig) );
    printf( "Conf = %6d  ", p->Pars.nBTLimit );
    printf( "JustMax = %5d  ", p->Pars.nJustLimit );
    printf( "\n" );
    printf( "Unsat calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
        p->nSatUnsat, p->nSatTotal? 100.0*p->nSatUnsat/p->nSatTotal :0.0, p->nSatUnsat? 1.0*p->nConfUnsat/p->nSatUnsat :0.0 );
    ABC_PRTP( "Time", p->timeSatUnsat, p->timeTotal );
    printf( "Sat   calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
        p->nSatSat,   p->nSatTotal? 100.0*p->nSatSat/p->nSatTotal :0.0, p->nSatSat? 1.0*p->nConfSat/p->nSatSat : 0.0 );
    ABC_PRTP( "Time", p->timeSatSat,   p->timeTotal );
    printf( "Undef calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
        p->nSatUndec, p->nSatTotal? 100.0*p->nSatUndec/p->nSatTotal :0.0, p->nSatUndec? 1.0*p->nConfUndec/p->nSatUndec : 0.0 );
    ABC_PRTP( "Time", p->timeSatUndec, p->timeTotal );
    ABC_PRT( "Total time", p->timeTotal );
}

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

  Synopsis    [Procedure to test the new SAT solver.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Int_t * CbsP_ManSolveMiterNc( Gia_Man_t * pAig, int nConfs, Vec_Str_t ** pvStatus, int f0Proved, int fVerbose )
{
    extern void Gia_ManCollectTest( Gia_Man_t * pAig );
    extern void Cec_ManSatAddToStore( Vec_Int_t * vCexStore, Vec_Int_t * vCex, int Out );
    CbsP_Man_t * p; 
    Vec_Int_t * vCex, * vVisit, * vCexStore;
    Vec_Str_t * vStatus;
    Gia_Obj_t * pRoot; 
    int i, status;
    abctime clk, clkTotal = Abc_Clock();
    assert( Gia_ManRegNum(pAig) == 0 );
//    Gia_ManCollectTest( pAig );
    // prepare AIG
    Gia_ManCreateRefs( pAig );
    Gia_ManCleanMark0( pAig );
    Gia_ManCleanMark1( pAig );
    Gia_ManFillValue( pAig ); // maps nodes into trail ids
    Gia_ManSetPhase( pAig ); // maps nodes into trail ids
    // create logic network
    p = CbsP_ManAlloc( pAig );
    p->Pars.nBTLimit = nConfs;
    // create resulting data-structures
    vStatus   = Vec_StrAlloc( Gia_ManPoNum(pAig) );
    vCexStore = Vec_IntAlloc( 10000 );
    vVisit    = Vec_IntAlloc( 100 );
    vCex      = CbsP_ReadModel( p );
    // solve for each output
    Gia_ManForEachCo( pAig, pRoot, i )
    {
//        printf( "\n" );

        Vec_IntClear( vCex );
        if ( Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) )
        {
            if ( Gia_ObjFaninC0(pRoot) )
            {
//                printf( "Constant 1 output of SRM!!!\n" );
                Cec_ManSatAddToStore( vCexStore, vCex, i ); // trivial counter-example
                Vec_StrPush( vStatus, 0 );
            }
            else
            {
//                printf( "Constant 0 output of SRM!!!\n" );
                Vec_StrPush( vStatus, 1 );
            }
            continue;
        }
        clk = Abc_Clock();
        p->Pars.fUseHighest = 1;
        p->Pars.fUseLowest  = 0;
        status = CbsP_ManSolve( p, Gia_ObjChild0(pRoot) );
//        printf( "\n" );
/*
        if ( status == -1 )
        {
            p->Pars.fUseHighest = 0;
            p->Pars.fUseLowest  = 1;
            status = CbsP_ManSolve( p, Gia_ObjChild0(pRoot) );
        }
*/
        Vec_StrPush( vStatus, (char)status );
        if ( status == -1 )
        {
            p->nSatUndec++;
            p->nConfUndec += p->Pars.nBTThis;
            Cec_ManSatAddToStore( vCexStore, NULL, i ); // timeout
            p->timeSatUndec += Abc_Clock() - clk;
            continue;
        }
        if ( status == 1 )
        {
            if ( f0Proved )
                Gia_ManPatchCoDriver( pAig, i, 0 );
            p->nSatUnsat++;
            p->nConfUnsat += p->Pars.nBTThis;
            p->timeSatUnsat += Abc_Clock() - clk;
            continue;
        }
        p->nSatSat++;
        p->nConfSat += p->Pars.nBTThis;
//        Gia_SatVerifyPattern( pAig, pRoot, vCex, vVisit );
        Cec_ManSatAddToStore( vCexStore, vCex, i );
        p->timeSatSat += Abc_Clock() - clk;
    }
    Vec_IntFree( vVisit );
    p->nSatTotal = Gia_ManPoNum(pAig);
    p->timeTotal = Abc_Clock() - clkTotal;
    if ( fVerbose )
        CbsP_ManSatPrintStats( p );
//    printf( "RecCalls = %8d.  RecClause = %8d.  RecNonChro = %8d.\n", p->nRecCall, p->nRecClause, p->nRecNonChro );
    CbsP_ManStop( p );
    *pvStatus = vStatus;

//    printf( "Total number of cex literals = %d. (Ave = %d)\n", 
//         Vec_IntSize(vCexStore)-2*p->nSatUndec-2*p->nSatSat, 
//        (Vec_IntSize(vCexStore)-2*p->nSatUndec-2*p->nSatSat)/p->nSatSat );
    return vCexStore;
}


////////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


ABC_NAMESPACE_IMPL_END