abcCollapse.c

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

  FileName    [abcCollapse.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Network and node package.]

  Synopsis    [Collapsing the network into two-levels.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "base/abc/abc.h"
#include "aig/gia/gia.h"
#include "misc/vec/vecWec.h"
#include "sat/cnf/cnf.h"
#include "sat/bsat/satStore.h"

#ifdef ABC_USE_CUDD
#include "bdd/extrab/extraBdd.h"
#endif

ABC_NAMESPACE_IMPL_START

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

#ifdef ABC_USE_CUDD

extern int Abc_NodeSupport( DdNode * bFunc, Vec_Str_t * vSupport, int nVars );

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

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

  Synopsis    [Makes nodes minimum base.]

  Description [Returns the number of changed nodes.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NodeMinimumBase2( Abc_Obj_t * pNode )
{
    Vec_Str_t * vSupport;
    Vec_Ptr_t * vFanins;
    DdNode * bTemp;
    int i, nVars;

    assert( Abc_NtkIsBddLogic(pNode->pNtk) );
    assert( Abc_ObjIsNode(pNode) );

    // compute support
    vSupport = Vec_StrAlloc( 10 );
    nVars = Abc_NodeSupport( Cudd_Regular(pNode->pData), vSupport, Abc_ObjFaninNum(pNode) );
    if ( nVars == Abc_ObjFaninNum(pNode) )
    {
        Vec_StrFree( vSupport );
        return 0;
    }

    // add fanins
    vFanins = Vec_PtrAlloc( Abc_ObjFaninNum(pNode) );
    Abc_NodeCollectFanins( pNode, vFanins );
    Vec_IntClear( &pNode->vFanins );
    for ( i = 0; i < vFanins->nSize; i++ )
        if ( vSupport->pArray[i] != 0 ) // useful
            Vec_IntPush( &pNode->vFanins, Abc_ObjId((Abc_Obj_t *)vFanins->pArray[i]) );
    assert( nVars == Abc_ObjFaninNum(pNode) );

    // update the function of the node
    pNode->pData = Extra_bddRemapUp( (DdManager *)pNode->pNtk->pManFunc, bTemp = (DdNode *)pNode->pData );   Cudd_Ref( (DdNode *)pNode->pData );
    Cudd_RecursiveDeref( (DdManager *)pNode->pNtk->pManFunc, bTemp );
    Vec_PtrFree( vFanins );
    Vec_StrFree( vSupport );
    return 1;
}
int Abc_NtkMinimumBase2( Abc_Ntk_t * pNtk )
{
    Abc_Obj_t * pNode, * pFanin;
    int i, k, Counter;
    assert( Abc_NtkIsBddLogic(pNtk) );
    // remove all fanouts
    Abc_NtkForEachObj( pNtk, pNode, i )
        Vec_IntClear( &pNode->vFanouts );
    // add useful fanins
    Counter = 0;
    Abc_NtkForEachNode( pNtk, pNode, i )
        Counter += Abc_NodeMinimumBase2( pNode );
    // add fanouts
    Abc_NtkForEachObj( pNtk, pNode, i )
        Abc_ObjForEachFanin( pNode, pFanin, k )
            Vec_IntPush( &pFanin->vFanouts, Abc_ObjId(pNode) );
    return Counter;
}

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

  Synopsis    [Collapses the network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Obj_t * Abc_NodeFromGlobalBdds( Abc_Ntk_t * pNtkNew, DdManager * dd, DdNode * bFunc, int fReverse )
{
    Abc_Obj_t * pNodeNew, * pTemp;
    int i;
    // create a new node
    pNodeNew = Abc_NtkCreateNode( pNtkNew );
    // add the fanins in the order, in which they appear in the reordered manager
    Abc_NtkForEachCi( pNtkNew, pTemp, i )
        Abc_ObjAddFanin( pNodeNew, Abc_NtkCi(pNtkNew, fReverse ? Abc_NtkCiNum(pNtkNew)-1-dd->invperm[i] : dd->invperm[i]) );
    // transfer the function
    pNodeNew->pData = Extra_TransferLevelByLevel( dd, (DdManager *)pNtkNew->pManFunc, bFunc );  Cudd_Ref( (DdNode *)pNodeNew->pData );
    return pNodeNew;
}
Abc_Ntk_t * Abc_NtkFromGlobalBdds( Abc_Ntk_t * pNtk, int fReverse )
{
    ProgressBar * pProgress;
    Abc_Ntk_t * pNtkNew;
    Abc_Obj_t * pNode, * pDriver, * pNodeNew;
    DdManager * dd = (DdManager *)Abc_NtkGlobalBddMan( pNtk );
    int i;

    // extract don't-care and compute ISOP
    if ( pNtk->pExdc )
    {
        DdManager * ddExdc = NULL;
        DdNode * bBddMin, * bBddDc, * bBddL, * bBddU;
        assert( Abc_NtkIsStrash(pNtk->pExdc) );
        assert( Abc_NtkCoNum(pNtk->pExdc) == 1 );
        // compute the global BDDs
        if ( Abc_NtkBuildGlobalBdds(pNtk->pExdc, 10000000, 1, 1, 0, 0) == NULL )
            return NULL;
        // transfer tot the same manager
        ddExdc = (DdManager *)Abc_NtkGlobalBddMan( pNtk->pExdc );
        bBddDc = (DdNode *)Abc_ObjGlobalBdd(Abc_NtkCo(pNtk->pExdc, 0));
        bBddDc = Cudd_bddTransfer( ddExdc, dd, bBddDc );  Cudd_Ref( bBddDc );
        Abc_NtkFreeGlobalBdds( pNtk->pExdc, 1 );
        // minimize the output
        Abc_NtkForEachCo( pNtk, pNode, i )
        {
            bBddMin = (DdNode *)Abc_ObjGlobalBdd(pNode);
            // derive lower and uppwer bound
            bBddL = Cudd_bddAnd( dd, bBddMin,           Cudd_Not(bBddDc) );  Cudd_Ref( bBddL );
            bBddU = Cudd_bddAnd( dd, Cudd_Not(bBddMin), Cudd_Not(bBddDc) );  Cudd_Ref( bBddU );
            Cudd_RecursiveDeref( dd, bBddMin );
            // compute new one
            bBddMin = Cudd_bddIsop( dd, bBddL, Cudd_Not(bBddU) );            Cudd_Ref( bBddMin );
            Cudd_RecursiveDeref( dd, bBddL );
            Cudd_RecursiveDeref( dd, bBddU );
            // update global BDD
            Abc_ObjSetGlobalBdd( pNode, bBddMin );
            //Extra_bddPrint( dd, bBddMin ); printf( "\n" );
        }
        Cudd_RecursiveDeref( dd, bBddDc );
    }

    // start the new network
    pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_LOGIC, ABC_FUNC_BDD );
    // make sure the new manager has the same number of inputs
    Cudd_bddIthVar( (DdManager *)pNtkNew->pManFunc, dd->size-1 );
    // process the POs
    pProgress = Extra_ProgressBarStart( stdout, Abc_NtkCoNum(pNtk) );
    Abc_NtkForEachCo( pNtk, pNode, i )
    {
        Extra_ProgressBarUpdate( pProgress, i, NULL );
        pDriver = Abc_ObjFanin0(pNode);
        if ( Abc_ObjIsCi(pDriver) && !strcmp(Abc_ObjName(pNode), Abc_ObjName(pDriver)) )
        {
            Abc_ObjAddFanin( pNode->pCopy, pDriver->pCopy );
            continue;
        }
        pNodeNew = Abc_NodeFromGlobalBdds( pNtkNew, dd, (DdNode *)Abc_ObjGlobalBdd(pNode), fReverse );
        Abc_ObjAddFanin( pNode->pCopy, pNodeNew );

    }
    Extra_ProgressBarStop( pProgress );
    return pNtkNew;
}
void Abc_NtkDumpVariableOrder( Abc_Ntk_t * pNtk )
{
    DdManager * dd = (DdManager *)Abc_NtkGlobalBddMan( pNtk );
    FILE * pFile = fopen( "order.txt", "wb" ); int i;
    for ( i = 0; i < dd->size; i++ )
        fprintf( pFile, "%d ", dd->invperm[i] );
    fprintf( pFile, "\n" );
    fclose( pFile );
}
Abc_Ntk_t * Abc_NtkCollapse( Abc_Ntk_t * pNtk, int fBddSizeMax, int fDualRail, int fReorder, int fReverse, int fDumpOrder, int fVerbose )
{
    Abc_Ntk_t * pNtkNew;
    abctime clk = Abc_Clock();

    assert( Abc_NtkIsStrash(pNtk) );
    // compute the global BDDs
    if ( Abc_NtkBuildGlobalBdds(pNtk, fBddSizeMax, 1, fReorder, fReverse, fVerbose) == NULL )
        return NULL;
    if ( fVerbose )
    {
        DdManager * dd = (DdManager *)Abc_NtkGlobalBddMan( pNtk );
        printf( "Shared BDD size = %6d nodes.  ", Cudd_ReadKeys(dd) - Cudd_ReadDead(dd) );
        ABC_PRT( "BDD construction time", Abc_Clock() - clk );
    }
    if ( fDumpOrder ) 
        Abc_NtkDumpVariableOrder( pNtk );

    // create the new network
    pNtkNew = Abc_NtkFromGlobalBdds( pNtk, fReverse );
    Abc_NtkFreeGlobalBdds( pNtk, 1 );
    if ( pNtkNew == NULL )
        return NULL;

    // make the network minimum base
    Abc_NtkMinimumBase2( pNtkNew );

    if ( pNtk->pExdc )
        pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );

    // make sure that everything is okay
    if ( !Abc_NtkCheck( pNtkNew ) )
    {
        printf( "Abc_NtkCollapse: The network check has failed.\n" );
        Abc_NtkDelete( pNtkNew );
        return NULL;
    }
    return pNtkNew;
}


#else

Abc_Ntk_t * Abc_NtkCollapse( Abc_Ntk_t * pNtk, int fBddSizeMax, int fDualRail, int fReorder, int fReverse, int fDumpOrder, int fVerbose )
{
    return NULL;
}

#endif


#if 0

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

  Synopsis    [Derives GIA for the cone of one output and computes its SOP.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkClpOneGia_rec( Gia_Man_t * pNew, Abc_Obj_t * pNode )
{
    int iLit0, iLit1;
    if ( Abc_NodeIsTravIdCurrent(pNode) || Abc_ObjFaninNum(pNode) == 0 || Abc_ObjIsCi(pNode) )
        return pNode->iTemp;
    assert( Abc_ObjIsNode( pNode ) );
    Abc_NodeSetTravIdCurrent( pNode );
    iLit0 = Abc_NtkClpOneGia_rec( pNew, Abc_ObjFanin0(pNode) );
    iLit1 = Abc_NtkClpOneGia_rec( pNew, Abc_ObjFanin1(pNode) );
    iLit0 = Abc_LitNotCond( iLit0, Abc_ObjFaninC0(pNode) );
    iLit1 = Abc_LitNotCond( iLit1, Abc_ObjFaninC1(pNode) );
    return (pNode->iTemp = Gia_ManHashAnd(pNew, iLit0, iLit1));
}
Gia_Man_t * Abc_NtkClpOneGia( Abc_Ntk_t * pNtk, int iCo, Vec_Int_t * vSupp )
{
    int i, iCi, iLit;
    Abc_Obj_t * pNode;
    Gia_Man_t * pNew, * pTemp;
    pNew = Gia_ManStart( 1000 );
    pNew->pName = Abc_UtilStrsav( pNtk->pName );
    pNew->pSpec = Abc_UtilStrsav( pNtk->pSpec );
    Gia_ManHashStart( pNew );
    // primary inputs
    Abc_AigConst1(pNtk)->iTemp = 1;
    Vec_IntForEachEntry( vSupp, iCi, i )
        Abc_NtkCi(pNtk, iCi)->iTemp = Gia_ManAppendCi(pNew);
    // create the first cone
    Abc_NtkIncrementTravId( pNtk );
    pNode = Abc_NtkCo( pNtk, iCo );
    iLit = Abc_NtkClpOneGia_rec( pNew, Abc_ObjFanin0(pNode) );
    iLit = Abc_LitNotCond( iLit, Abc_ObjFaninC0(pNode) );
    Gia_ManAppendCo( pNew, iLit );
    // perform cleanup
    pNew = Gia_ManCleanup( pTemp = pNew );
    Gia_ManStop( pTemp );
    return pNew;
}
Vec_Str_t * Abc_NtkClpOne( Abc_Ntk_t * pNtk, int iCo, int nCubeLim, int nBTLimit, int fVerbose, int fCanon, int fReverse, Vec_Int_t * vSupp )
{
    Vec_Str_t * vSop;
    abctime clk = Abc_Clock();
    extern Vec_Str_t * Bmc_CollapseOne( Gia_Man_t * p, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose );
    Gia_Man_t * pGia  = Abc_NtkClpOneGia( pNtk, iCo, vSupp );
    if ( fVerbose )
        printf( "Output %4d:  Supp = %4d. Cone =%6d.\n", iCo, Vec_IntSize(vSupp), Gia_ManAndNum(pGia) );
    vSop = Bmc_CollapseOne( pGia, nCubeLim, nBTLimit, fCanon, fReverse, fVerbose );
    Gia_ManStop( pGia );
    if ( vSop == NULL )
        return NULL;
    if ( Vec_StrSize(vSop) == 4 ) // constant
        Vec_IntClear(vSupp);
    if ( fVerbose )
        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
    return vSop; 
}

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

  Synopsis    [Collect structural support for all nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Wec_t * Abc_NtkCreateCoSupps( Abc_Ntk_t * pNtk, int fVerbose )
{
    abctime clk = Abc_Clock();
    Abc_Obj_t * pNode; int i;
    Vec_Wec_t * vSupps = Vec_WecStart( Abc_NtkObjNumMax(pNtk) );
    Abc_NtkForEachCi( pNtk, pNode, i )
        Vec_IntPush( Vec_WecEntry(vSupps, pNode->Id), i );
    Abc_NtkForEachNode( pNtk, pNode, i )
        Vec_IntTwoMerge2( Vec_WecEntry(vSupps, Abc_ObjFanin0(pNode)->Id), 
                          Vec_WecEntry(vSupps, Abc_ObjFanin1(pNode)->Id), 
                          Vec_WecEntry(vSupps, pNode->Id) ); 
    if ( fVerbose )
        Abc_PrintTime( 1, "Support computation", Abc_Clock() - clk );
    return vSupps;
}

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

  Synopsis    [Derive array of COs sorted by cone size in the reverse order.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NodeCompareByTemp( Abc_Obj_t ** pp1, Abc_Obj_t ** pp2 )
{
    int Diff = (*pp2)->iTemp - (*pp1)->iTemp;
    if ( Diff < 0 )
        return -1;
    if ( Diff > 0 ) 
        return 1;
    Diff = strcmp( Abc_ObjName(*pp1), Abc_ObjName(*pp2) );
    if ( Diff < 0 )
        return -1;
    if ( Diff > 0 ) 
        return 1;
    return 0; 
}
Vec_Ptr_t * Abc_NtkCreateCoOrder( Abc_Ntk_t * pNtk, Vec_Wec_t * vSupps )
{
    Abc_Obj_t * pNode; int i;
    Vec_Ptr_t * vNodes = Vec_PtrAlloc( Abc_NtkCoNum(pNtk) );
    Abc_NtkForEachCo( pNtk, pNode, i )
    {
        pNode->iTemp = Vec_IntSize( Vec_WecEntry(vSupps, Abc_ObjFaninId0(pNode)) );
        Vec_PtrPush( vNodes, pNode );
    }
    // order objects alphabetically
    qsort( (void *)Vec_PtrArray(vNodes), (size_t)Vec_PtrSize(vNodes), sizeof(Abc_Obj_t *), 
        (int (*)(const void *, const void *)) Abc_NodeCompareByTemp );
    // cleanup
//    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
//        printf( "%s %d ", Abc_ObjName(pNode), pNode->iTemp );
//    printf( "\n" );
    return vNodes;
}

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

  Synopsis    [SAT-based collapsing.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Obj_t * Abc_NtkFromSopsOne( Abc_Ntk_t * pNtkNew, Abc_Ntk_t * pNtk, int iCo, Vec_Int_t * vSupp, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose )
{
    Abc_Obj_t * pNodeNew;
    Vec_Str_t * vSop;
    int i, iCi;
    // compute SOP of the node
    vSop = Abc_NtkClpOne( pNtk, iCo, nCubeLim, nBTLimit, fVerbose, fCanon, fReverse, vSupp );
    if ( vSop == NULL )
        return NULL;
    // create a new node
    pNodeNew = Abc_NtkCreateNode( pNtkNew );
    // add fanins
    if ( Vec_StrSize(vSop) > 4 ) // non-constant SOP
        Vec_IntForEachEntry( vSupp, iCi, i )
            Abc_ObjAddFanin( pNodeNew, Abc_NtkCi(pNtkNew, iCi) );
    // transfer the function
    pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Vec_StrArray(vSop) );
    Vec_StrFree( vSop );
    return pNodeNew;
}
Abc_Ntk_t * Abc_NtkFromSops( Abc_Ntk_t * pNtk, int nCubeLim, int nBTLimit, int nCostMax, int fCanon, int fReverse, int fVerbose )
{
    ProgressBar * pProgress;
    Abc_Ntk_t * pNtkNew;
    Abc_Obj_t * pNode, * pDriver, * pNodeNew;
    Vec_Ptr_t * vDriverCopy, * vCoNodes, * vDfsNodes;
    Vec_Int_t * vNodeCoIds, * vLevel;
    Vec_Wec_t * vSupps;
    int i; 

//    Abc_NtkForEachCi( pNtk, pNode, i )
//        printf( "%d ", Abc_ObjFanoutNum(pNode) );
//    printf( "\n" );

    // compute structural supports
    vSupps = Abc_NtkCreateCoSupps( pNtk, fVerbose );
    // order CO nodes by support size
    vCoNodes = Abc_NtkCreateCoOrder( pNtk, vSupps );
    // compute cost of the largest node
    if ( nCubeLim > 0 )
    {
        word Cost;
        pNode     = (Abc_Obj_t *)Vec_PtrEntry( vCoNodes, 0 );
        vDfsNodes = Abc_NtkDfsNodes( pNtk, &pNode, 1 );
        vLevel    = Vec_WecEntry( vSupps, Abc_ObjFaninId0(pNode) );
        Cost      = (word)Vec_PtrSize(vDfsNodes) * (word)Vec_IntSize(vLevel) * (word)nCubeLim;
        if ( Cost > (word)nCostMax )
        {
            printf( "Cost of the largest output cone exceeded the limit (%d * %d * %d  >  %d).\n", 
                Vec_PtrSize(vDfsNodes), Vec_IntSize(vLevel), nCubeLim, nCostMax );
            Vec_PtrFree( vDfsNodes );
            Vec_PtrFree( vCoNodes );
            Vec_WecFree( vSupps );
            return NULL;
        }
        Vec_PtrFree( vDfsNodes );
    }
    // collect CO IDs in this order
    vNodeCoIds = Vec_IntAlloc( Abc_NtkCoNum(pNtk) );
    Abc_NtkForEachCo( pNtk, pNode, i )
        pNode->iTemp = i;
    Vec_PtrForEachEntry( Abc_Obj_t *, vCoNodes, pNode, i )
        Vec_IntPush( vNodeCoIds, pNode->iTemp );

    // start the new network
    pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_LOGIC, ABC_FUNC_SOP );
    // collect driver copies
    vDriverCopy = Vec_PtrAlloc( Abc_NtkCoNum(pNtk) );
//    Abc_NtkForEachCo( pNtk, pNode, i )
    Vec_PtrForEachEntry( Abc_Obj_t *, vCoNodes, pNode, i )
        Vec_PtrPush( vDriverCopy, Abc_ObjFanin0(pNode)->pCopy );
    // process the POs
    pProgress = Extra_ProgressBarStart( stdout, Abc_NtkCoNum(pNtk) );
//    Abc_NtkForEachCo( pNtk, pNode, i )
    Vec_PtrForEachEntry( Abc_Obj_t *, vCoNodes, pNode, i )
    {
        Extra_ProgressBarUpdate( pProgress, i, NULL );
        pDriver = Abc_ObjFanin0(pNode);
        if ( Abc_ObjIsCi(pDriver) && !strcmp(Abc_ObjName(pNode), Abc_ObjName(pDriver)) )
        {
            Abc_ObjAddFanin( pNode->pCopy, (Abc_Obj_t *)Vec_PtrEntry(vDriverCopy, i) );
            continue;
        }
        if ( Abc_ObjIsCi(pDriver) )
        {
            pNodeNew = Abc_NtkCreateNode( pNtkNew );
            Abc_ObjAddFanin( pNodeNew, (Abc_Obj_t *)Vec_PtrEntry(vDriverCopy, i) ); 
            pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Abc_ObjFaninC0(pNode) ? "0 1\n" : "1 1\n" );
            Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
            continue;
        }
        if ( pDriver == Abc_AigConst1(pNtk) )
        {
            pNodeNew = Abc_NtkCreateNode( pNtkNew );
            pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Abc_ObjFaninC0(pNode) ? " 0\n" : " 1\n" );
            Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
            continue;
        }
        pNodeNew = Abc_NtkFromSopsOne( pNtkNew, pNtk, Vec_IntEntry(vNodeCoIds, i), Vec_WecEntry(vSupps, Abc_ObjFanin0(pNode)->Id), nCubeLim, nBTLimit, fCanon, fReverse, i ? 0 : fVerbose );
        if ( pNodeNew == NULL )
        {
            Abc_NtkDelete( pNtkNew );
            pNtkNew = NULL;
            break;
        }
        Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
    }
    Vec_PtrFree( vDriverCopy );
    Vec_PtrFree( vCoNodes );
    Vec_IntFree( vNodeCoIds );
    Vec_WecFree( vSupps );
    Extra_ProgressBarStop( pProgress );
    return pNtkNew;
}
Abc_Ntk_t * Abc_NtkCollapseSat( Abc_Ntk_t * pNtk, int nCubeLim, int nBTLimit, int nCostMax, int fCanon, int fReverse, int fVerbose )
{
    Abc_Ntk_t * pNtkNew;
    assert( Abc_NtkIsStrash(pNtk) );
    // create the new network
    pNtkNew = Abc_NtkFromSops( pNtk, nCubeLim, nBTLimit, nCostMax, fCanon, fReverse, fVerbose );
    if ( pNtkNew == NULL )
        return NULL;
    if ( pNtk->pExdc )
        pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );
    // make sure that everything is okay
    if ( !Abc_NtkCheck( pNtkNew ) )
    {
        printf( "Abc_NtkCollapseSat: The network check has failed.\n" );
        Abc_NtkDelete( pNtkNew );
        return NULL;
    }
    return pNtkNew;
}

#endif



extern Vec_Wec_t * Gia_ManCreateCoSupps( Gia_Man_t * p, int fVerbose );
extern int         Gia_ManCoLargestSupp( Gia_Man_t * p, Vec_Wec_t * vSupps );
extern Vec_Wec_t * Gia_ManIsoStrashReduceInt( Gia_Man_t * p, Vec_Wec_t * vSupps, int fVerbose );

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

  Synopsis    [Derives GIA for the network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkClpGia_rec( Gia_Man_t * pNew, Abc_Obj_t * pNode )
{
    int iLit0, iLit1;
    if ( pNode->iTemp >= 0 )
        return pNode->iTemp;
    assert( Abc_ObjIsNode( pNode ) );
    iLit0 = Abc_NtkClpGia_rec( pNew, Abc_ObjFanin0(pNode) );
    iLit1 = Abc_NtkClpGia_rec( pNew, Abc_ObjFanin1(pNode) );
    iLit0 = Abc_LitNotCond( iLit0, Abc_ObjFaninC0(pNode) );
    iLit1 = Abc_LitNotCond( iLit1, Abc_ObjFaninC1(pNode) );
    return (pNode->iTemp = Gia_ManAppendAnd(pNew, iLit0, iLit1));
}
Gia_Man_t * Abc_NtkClpGia( Abc_Ntk_t * pNtk )
{
    int i, iLit;
    Gia_Man_t * pNew;
    Abc_Obj_t * pNode;
    assert( Abc_NtkIsStrash(pNtk) );
    pNew = Gia_ManStart( 1000 );
    pNew->pName = Abc_UtilStrsav( pNtk->pName );
    pNew->pSpec = Abc_UtilStrsav( pNtk->pSpec );
    Abc_NtkForEachObj( pNtk, pNode, i )
        pNode->iTemp = -1;
    Abc_AigConst1(pNtk)->iTemp = 1;
    Abc_NtkForEachCi( pNtk, pNode, i )
        pNode->iTemp = Gia_ManAppendCi(pNew);
    Abc_NtkForEachCo( pNtk, pNode, i )
    {
        iLit = Abc_NtkClpGia_rec( pNew, Abc_ObjFanin0(pNode) );
        iLit = Abc_LitNotCond( iLit, Abc_ObjFaninC0(pNode) );
        Gia_ManAppendCo( pNew, iLit );
    }
    return pNew;
}

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

  Synopsis    [Minimize SOP by removing redundant variables.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
#define Abc_NtkSopForEachCube( pSop, nVars, pCube )  for ( pCube = (pSop); *pCube; pCube += (nVars) + 3 )

int Abc_NtkCollapseReduce( Vec_Str_t * vSop, Vec_Int_t * vSupp, Vec_Int_t * vClass, Vec_Wec_t * vSupps )
{
    int j = 0, i, k, iCo, iVar, nVars = Vec_IntSize(vSupp);
    char * pCube, * pSop = Vec_StrArray(vSop);
    Vec_Int_t * vPres;
    if ( Vec_StrSize(vSop) == 4 ) // constant
    {
        Vec_IntForEachEntry( vClass, iCo, i )
            Vec_IntClear( Vec_WecEntry(vSupps, iCo) );
        return 1;
    }
    vPres = Vec_IntStart( nVars );
    Abc_NtkSopForEachCube( pSop, nVars, pCube )
        for ( k = 0; k < nVars; k++ )
            if ( pCube[k] != '-' )
                Vec_IntWriteEntry( vPres, k, 1 );
    if ( Vec_IntCountZero(vPres) == 0 )
    {
        Vec_IntFree( vPres );
        return 0;
    }
    // reduce cubes
    Abc_NtkSopForEachCube( pSop, nVars, pCube )
        for ( k = 0; k < nVars + 3; k++ )
            if ( k >= nVars || Vec_IntEntry(vPres, k) )
                Vec_StrWriteEntry( vSop, j++, pCube[k] );
    Vec_StrWriteEntry( vSop, j++, '\0' );
    Vec_StrShrink( vSop, j );
    // reduce support
    Vec_IntForEachEntry( vClass, iCo, i )
    {
        j = 0;
        vSupp = Vec_WecEntry( vSupps, iCo );
        Vec_IntForEachEntry( vSupp, iVar, k )
            if ( Vec_IntEntry(vPres, k) )
                Vec_IntWriteEntry( vSupp, j++, iVar );
        Vec_IntShrink( vSupp, j );
    }
    Vec_IntFree( vPres );
//    if ( Vec_IntSize(vSupp) != Abc_SopGetVarNum(Vec_StrArray(vSop)) )
//        printf( "Mismatch!!!\n" );
    return 1;
}


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

  Synopsis    [Derives SAT solver for one output from the shared CNF.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
sat_solver * Abc_NtkClpDeriveSatSolver( Cnf_Dat_t * pCnf, int iCoObjId, Vec_Int_t * vSupp, Vec_Int_t * vAnds, Vec_Int_t * vMap, sat_solver ** ppSat1, sat_solver ** ppSat2, sat_solver ** ppSat3 )
{
    int i, k, iObj, status, nVars = 2;
//    int i, k, iObj, status, nVars = 1;
    Vec_Int_t * vLits = Vec_IntAlloc( 16 );
    sat_solver * pSat = sat_solver_new();
    if ( ppSat1 ) *ppSat1 = sat_solver_new();
    if ( ppSat2 ) *ppSat2 = sat_solver_new();
    if ( ppSat3 ) *ppSat3 = sat_solver_new();
    // assign SAT variable numbers
    Vec_IntWriteEntry( vMap, iCoObjId, nVars++ );
    Vec_IntForEachEntry( vSupp, iObj, k )
        Vec_IntWriteEntry( vMap, iObj, nVars++ );
    Vec_IntForEachEntry( vAnds, iObj, k )
        if ( pCnf->pObj2Clause[iObj] != -1 )
            Vec_IntWriteEntry( vMap, iObj, nVars++ );
//    Vec_IntForEachEntry( vSupp, iObj, k )
//        Vec_IntWriteEntry( vMap, iObj, nVars++ );
    // create clauses for the internal nodes and for the output
    sat_solver_setnvars( pSat, nVars );
    if ( ppSat1 ) sat_solver_setnvars( *ppSat1, nVars );
    if ( ppSat2 ) sat_solver_setnvars( *ppSat2, nVars );
    if ( ppSat3 ) sat_solver_setnvars( *ppSat3, nVars );
    Vec_IntPush( vAnds, iCoObjId );
    Vec_IntForEachEntry( vAnds, iObj, k )
    {
        int iClaBeg, iClaEnd, * pLit;
        if ( pCnf->pObj2Clause[iObj] == -1 )
            continue;
        iClaBeg = pCnf->pObj2Clause[iObj];
        iClaEnd = iClaBeg + pCnf->pObj2Count[iObj];
        assert( iClaBeg < iClaEnd );
        for ( i = iClaBeg; i < iClaEnd; i++ )
        {
            Vec_IntClear( vLits );
            for ( pLit = pCnf->pClauses[i]; pLit < pCnf->pClauses[i+1]; pLit++ )
                Vec_IntPush( vLits, Abc_Lit2LitV(Vec_IntArray(vMap), *pLit) );
            status = sat_solver_addclause( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits)+Vec_IntSize(vLits) );
            assert( status );
            (void) status;
            if ( ppSat1 ) sat_solver_addclause( *ppSat1, Vec_IntArray(vLits), Vec_IntArray(vLits)+Vec_IntSize(vLits) );
            if ( ppSat2 ) sat_solver_addclause( *ppSat2, Vec_IntArray(vLits), Vec_IntArray(vLits)+Vec_IntSize(vLits) );
            if ( ppSat3 ) sat_solver_addclause( *ppSat3, Vec_IntArray(vLits), Vec_IntArray(vLits)+Vec_IntSize(vLits) );
        }
    }
    Vec_IntPop( vAnds );
    Vec_IntFree( vLits );
    assert( nVars == sat_solver_nvars(pSat) );
    return pSat;
}

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

  Synopsis    [Computes SOPs for each output.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Str_t * Abc_NtkClpGiaOne( Gia_Man_t * p, int iCo, int nCubeLim, int nBTLimit, int fCanon, int fReverse, Vec_Int_t * vSupp, int fVerbose, Vec_Int_t * vClass, Vec_Wec_t * vSupps )
{
    Vec_Str_t * vSop;
    abctime clk = Abc_Clock();
    extern Vec_Str_t * Bmc_CollapseOneOld( Gia_Man_t * p, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose );
    Gia_Man_t * pGia  = Gia_ManDupCones( p, &iCo, 1, 1 );
    if ( fVerbose )
        printf( "Output %4d:  Supp = %4d. Cone =%6d.\n", iCo, Vec_IntSize(vSupp), Gia_ManAndNum(pGia) );
    vSop = Bmc_CollapseOneOld( pGia, nCubeLim, nBTLimit, fCanon, fReverse, fVerbose );
    Gia_ManStop( pGia );
    if ( vSop == NULL )
        return NULL;
    Abc_NtkCollapseReduce( vSop, vSupp, vClass, vSupps );
    if ( fVerbose )
        printf( "Supp new = %4d. Sop = %4d.  ", Vec_IntSize(vSupp), Vec_StrSize(vSop)/(Vec_IntSize(vSupp) +3) );
    if ( fVerbose )
        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
    return vSop; 
}
Vec_Str_t * Abc_NtkClpGiaOne2( Cnf_Dat_t * pCnf, Gia_Man_t * p, int iCo, int nCubeLim, int nBTLimit, int fCanon, int fReverse, Vec_Int_t * vSupp, Vec_Int_t * vMap, int fVerbose, Vec_Int_t * vClass, Vec_Wec_t * vSupps )
{
    Vec_Str_t * vSop;
    sat_solver * pSat, * pSat1 = NULL, * pSat2 = NULL, * pSat3 = NULL;
    Gia_Obj_t * pObj;
    abctime clk = Abc_Clock();
    extern Vec_Str_t * Bmc_CollapseOne_int( sat_solver * pSat, int nVars, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose );
    extern Vec_Str_t * Bmc_CollapseOne_int2( sat_solver * pSat, sat_solver * pSat2, int nVars, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose );
    extern Vec_Str_t * Bmc_CollapseOne_int3( sat_solver * pSat, sat_solver * pSat1, sat_solver * pSat2, sat_solver * pSat3, int nVars, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose );
    int i, iCoObjId = Gia_ObjId( p, Gia_ManCo(p, iCo) );
    Vec_Int_t * vAnds = Vec_IntAlloc( 100 );
    Vec_Int_t * vSuppObjs = Vec_IntAlloc( 100 );
    Gia_ManForEachCiVec( vSupp, p, pObj, i )
        Vec_IntPush( vSuppObjs, Gia_ObjId(p, pObj) );
    Gia_ManIncrementTravId( p );
    Gia_ManCollectAnds( p, &iCoObjId, 1, vAnds, NULL );
    assert( Vec_IntSize(vAnds) > 0 );
//    pSat = Abc_NtkClpDeriveSatSolver( pCnf, iCoObjId, vSuppObjs, vAnds, vMap, &pSat1, &pSat2, &pSat3 );
    pSat = Abc_NtkClpDeriveSatSolver( pCnf, iCoObjId, vSuppObjs, vAnds, vMap, NULL, NULL, NULL );
    Vec_IntFree( vSuppObjs );
    if ( fVerbose )
        printf( "Output %4d:  Supp = %4d. Cone =%6d.\n", iCo, Vec_IntSize(vSupp), Vec_IntSize(vAnds) );
//    vSop = Bmc_CollapseOne_int3( pSat, pSat1, pSat2, pSat3, Vec_IntSize(vSupp), nCubeLim, nBTLimit, fCanon, fReverse, fVerbose );
//    vSop = Bmc_CollapseOne_int2( pSat, pSat1, Vec_IntSize(vSupp), nCubeLim, nBTLimit, fCanon, fReverse, fVerbose );
    vSop = Bmc_CollapseOne_int( pSat, Vec_IntSize(vSupp), nCubeLim, nBTLimit, fCanon, fReverse, fVerbose );
    sat_solver_delete( pSat );
    if ( pSat1 ) sat_solver_delete( pSat1 );
    if ( pSat2 ) sat_solver_delete( pSat2 );
    if ( pSat3 ) sat_solver_delete( pSat3 );
    Vec_IntFree( vAnds );
    if ( vSop == NULL )
        return NULL;
    Abc_NtkCollapseReduce( vSop, vSupp, vClass, vSupps );
    if ( fVerbose )
        printf( "Supp new = %4d. Sop = %4d.  ", Vec_IntSize(vSupp), Vec_StrSize(vSop)/(Vec_IntSize(vSupp) +3) );
    if ( fVerbose )
        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
    return vSop; 
}
Vec_Ptr_t * Abc_GiaDeriveSops( Abc_Ntk_t * pNtkNew, Gia_Man_t * p, Vec_Wec_t * vSupps, int nCubeLim, int nBTLimit, int nCostMax, int fCanon, int fReverse, int fCnfShared, int fVerbose )
{
    ProgressBar * pProgress;
    abctime clk = Abc_Clock();
    Vec_Ptr_t * vSops = NULL, * vSopsRepr;
    Vec_Int_t * vReprs, * vClass, * vReprSuppSizes;
    int i, k, Entry, iCo, * pOrder;
    Vec_Wec_t * vClasses;
    Cnf_Dat_t * pCnf = NULL;
    Vec_Int_t * vMap = NULL;
    // derive classes of outputs
    vClasses = Gia_ManIsoStrashReduceInt( p, vSupps, 0 );
    if ( fVerbose )
    {
        printf( "Considering %d (out of %d) outputs. ", Vec_WecSize(vClasses), Gia_ManCoNum(p) );
        Abc_PrintTime( 1, "Reduction time", Abc_Clock() - clk );
    }
    // derive representatives
    vReprs = Vec_WecCollectFirsts( vClasses );
    vReprSuppSizes = Vec_IntAlloc( Vec_IntSize(vReprs) );
    Vec_IntForEachEntry( vReprs, Entry, i )
        Vec_IntPush( vReprSuppSizes, Vec_IntSize(Vec_WecEntry(vSupps, Entry)) );
    pOrder = Abc_MergeSortCost( Vec_IntArray(vReprSuppSizes), Vec_IntSize(vReprSuppSizes) );
    Vec_IntFree( vReprSuppSizes );
    // consider SOPs for representatives
    if ( fCnfShared )
    {
        vMap = Vec_IntStartFull( Gia_ManObjNum(p) );
        pCnf = (Cnf_Dat_t *)Mf_ManGenerateCnf( p, 8, 1, 0, 0, 0 );
    }
    vSopsRepr = Vec_PtrStart( Vec_IntSize(vReprs) );
    pProgress = Extra_ProgressBarStart( stdout, Vec_IntSize(vReprs) );
    Extra_ProgressBarUpdate( pProgress, 0, NULL );
    for ( i = 0; i < Vec_IntSize(vReprs); i++ )
    {
        int iEntry        = pOrder[Vec_IntSize(vReprs) - 1 - i];
        int iCoThis       = Vec_IntEntry( vReprs, iEntry );
        Vec_Int_t * vSupp = Vec_WecEntry( vSupps, iCoThis );
        Vec_Str_t * vSop;
        if ( Vec_IntSize(vSupp) < 2 )
        {
            Vec_PtrWriteEntry( vSopsRepr, iEntry, (void *)(ABC_PTRINT_T)1 );
            continue;
        }
        if ( fCnfShared && !fCanon )
            vSop = Abc_NtkClpGiaOne2( pCnf, p, iCoThis, nCubeLim, nBTLimit, fCanon, fReverse, vSupp, vMap, i ? 0 : fVerbose, Vec_WecEntry(vClasses, iEntry), vSupps );
        else
            vSop = Abc_NtkClpGiaOne( p, iCoThis, nCubeLim, nBTLimit, fCanon, fReverse, vSupp, i ? 0 : fVerbose, Vec_WecEntry(vClasses, iEntry), vSupps );
        if ( vSop == NULL )
            goto finish;
        assert( Vec_IntSize( Vec_WecEntry(vSupps, iCoThis) ) == Abc_SopGetVarNum(Vec_StrArray(vSop)) );
        Extra_ProgressBarUpdate( pProgress, i, NULL );
        Vec_PtrWriteEntry( vSopsRepr, iEntry, Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Vec_StrArray(vSop) ) );
        Vec_StrFree( vSop );
    }
    Extra_ProgressBarStop( pProgress );
    if ( fCnfShared )
    {
        Cnf_DataFree( pCnf );
        Vec_IntFree( vMap );
    }
    // derive SOPs for each output
    vSops = Vec_PtrStart( Gia_ManCoNum(p) );
    Vec_WecForEachLevel ( vClasses, vClass, i )
        Vec_IntForEachEntry( vClass, iCo, k )
            Vec_PtrWriteEntry( vSops, iCo, Vec_PtrEntry(vSopsRepr, i) );
    assert( Vec_PtrCountZero(vSops) == 0 );
/*
    // verify
    for ( i = 0; i < Gia_ManCoNum(p); i++ )
    {
        Vec_Int_t * vSupp = Vec_WecEntry( vSupps, i );
        char * pSop = (char *)Vec_PtrEntry( vSops, i );
        assert( Vec_IntSize(vSupp) == Abc_SopGetVarNum(pSop) );
    }
*/
    // cleanup
finish:
    ABC_FREE( pOrder );
    Vec_IntFree( vReprs );
    Vec_WecFree( vClasses );
    Vec_PtrFree( vSopsRepr );
    return vSops;
}
Abc_Ntk_t * Abc_NtkFromSopsInt( Abc_Ntk_t * pNtk, int nCubeLim, int nBTLimit, int nCostMax, int fCanon, int fReverse, int fCnfShared, int fVerbose )
{
    Abc_Ntk_t * pNtkNew;
    Gia_Man_t * pGia;
    Vec_Wec_t * vSupps;
    Vec_Int_t * vSupp;
    Vec_Ptr_t * vSops;
    Abc_Obj_t * pNode, * pNodeNew, * pDriver;
    int i, k, iCi; 
    pGia    = Abc_NtkClpGia( pNtk );
    vSupps  = Gia_ManCreateCoSupps( pGia, fVerbose );
    // check the largest output
    if ( nCubeLim > 0 && nCostMax > 0 )
    {
        int iCoMax   = Gia_ManCoLargestSupp( pGia, vSupps );
        int iObjMax  = Gia_ObjId( pGia, Gia_ManCo(pGia, iCoMax) );
        int nSuppMax = Vec_IntSize( Vec_WecEntry(vSupps, iCoMax) );
        int nNodeMax = Gia_ManConeSize( pGia, &iObjMax, 1 );
        word Cost = (word)nNodeMax * (word)nSuppMax * (word)nCubeLim;
        if ( Cost > (word)nCostMax )
        {
            printf( "Cost of the largest output cone exceeded the limit (%d * %d * %d  >  %d).\n", 
                nNodeMax, nSuppMax, nCubeLim, nCostMax );
            Gia_ManStop( pGia );
            Vec_WecFree( vSupps );
            return NULL;
        }
    }
    pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_LOGIC, ABC_FUNC_SOP );
    vSops   = Abc_GiaDeriveSops( pNtkNew, pGia, vSupps, nCubeLim, nBTLimit, nCostMax, fCanon, fReverse, fCnfShared, fVerbose );
    Gia_ManStop( pGia );
    if ( vSops == NULL )
    {
        Vec_WecFree( vSupps );
        Abc_NtkDelete( pNtkNew );
        return NULL;
    }
    Abc_NtkForEachCo( pNtk, pNode, i )
    {
        pDriver = Abc_ObjFanin0(pNode);
        if ( Abc_ObjIsCi(pDriver) && !strcmp(Abc_ObjName(pNode), Abc_ObjName(pDriver)) )
        {
            Abc_ObjAddFanin( pNode->pCopy, pDriver->pCopy );
            continue;
        }
        if ( Abc_ObjIsCi(pDriver) )
        {
            pNodeNew = Abc_NtkCreateNode( pNtkNew );
            Abc_ObjAddFanin( pNodeNew, pDriver->pCopy ); 
            pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Abc_ObjFaninC0(pNode) ? "0 1\n" : "1 1\n" );
            Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
            continue;
        }
        if ( pDriver == Abc_AigConst1(pNtk) )
        {
            pNodeNew = Abc_NtkCreateNode( pNtkNew );
            pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, Abc_ObjFaninC0(pNode) ? " 0\n" : " 1\n" );
            Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
            continue;
        }
        pNodeNew = Abc_NtkCreateNode( pNtkNew );
        vSupp = Vec_WecEntry( vSupps, i );
        Vec_IntForEachEntry( vSupp, iCi, k )
            Abc_ObjAddFanin( pNodeNew, Abc_NtkCi(pNtkNew, iCi) );
        pNodeNew->pData = Abc_SopRegister( (Mem_Flex_t *)pNtkNew->pManFunc, (const char*)Vec_PtrEntry( vSops, i ) );
        assert( pNodeNew->pData != (void *)(ABC_PTRINT_T)1 );
        Abc_ObjAddFanin( pNode->pCopy, pNodeNew );
    }
    Vec_WecFree( vSupps );
    Vec_PtrFree( vSops );
    Abc_NtkSortSops( pNtkNew );
    return pNtkNew;
}
Abc_Ntk_t * Abc_NtkCollapseSat( Abc_Ntk_t * pNtk, int nCubeLim, int nBTLimit, int nCostMax, int fCanon, int fReverse, int fCnfShared, int fVerbose )
{
    Abc_Ntk_t * pNtkNew;
    assert( Abc_NtkIsStrash(pNtk) );
    pNtkNew = Abc_NtkFromSopsInt( pNtk, nCubeLim, nBTLimit, nCostMax, fCanon, fReverse, fCnfShared, fVerbose );
    if ( pNtkNew == NULL )
        return NULL;
    if ( pNtk->pExdc )
        pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );
    if ( !Abc_NtkCheck( pNtkNew ) )
    {
        printf( "Abc_NtkCollapseSat: The network check has failed.\n" );
        Abc_NtkDelete( pNtkNew );
        return NULL;
    }
    return pNtkNew;
}


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


ABC_NAMESPACE_IMPL_END