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

  FileName    [abcFunc.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Network and node package.]

  Synopsis    [Transformations between different functionality representations.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "abc.h"
#include "base/main/main.h"
#include "map/mio/mio.h"
#include "misc/extra/extraBdd.h"

ABC_NAMESPACE_IMPL_START


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

#define ABC_MAX_CUBES   100000

int Abc_ConvertZddToSop( DdManager * dd, DdNode * zCover, char * pSop, int nFanins, Vec_Str_t * vCube, int fPhase );
static DdNode * Abc_ConvertAigToBdd( DdManager * dd, Hop_Obj_t * pRoot);
static Hop_Obj_t * Abc_ConvertSopToAig( Hop_Man_t * pMan, char * pSop );

extern int Abc_CountZddCubes( DdManager * dd, DdNode * zCover );

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

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

  Synopsis    [Converts the node from SOP to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
DdNode * Abc_ConvertSopToBdd( DdManager * dd, char * pSop, DdNode ** pbVars )
{
    DdNode * bSum, * bCube, * bTemp, * bVar;
    char * pCube;
    int nVars, Value, v;

    // start the cover
    nVars = Abc_SopGetVarNum(pSop);
    bSum = Cudd_ReadLogicZero(dd);   Cudd_Ref( bSum );
    if ( Abc_SopIsExorType(pSop) )
    {
        for ( v = 0; v < nVars; v++ )
        {
            bSum  = Cudd_bddXor( dd, bTemp = bSum, pbVars? pbVars[v] : Cudd_bddIthVar(dd, v) );   Cudd_Ref( bSum );
            Cudd_RecursiveDeref( dd, bTemp );
        }
    }
    else
    {
        // check the logic function of the node
        Abc_SopForEachCube( pSop, nVars, pCube )
        {
            bCube = Cudd_ReadOne(dd);   Cudd_Ref( bCube );
            Abc_CubeForEachVar( pCube, Value, v )
            {
                if ( Value == '0' )
                    bVar = Cudd_Not( pbVars? pbVars[v] : Cudd_bddIthVar( dd, v ) );
                else if ( Value == '1' )
                    bVar = pbVars? pbVars[v] : Cudd_bddIthVar( dd, v );
                else
                    continue;
                bCube  = Cudd_bddAnd( dd, bTemp = bCube, bVar );   Cudd_Ref( bCube );
                Cudd_RecursiveDeref( dd, bTemp );
            }
            bSum = Cudd_bddOr( dd, bTemp = bSum, bCube );   
            Cudd_Ref( bSum );
            Cudd_RecursiveDeref( dd, bTemp );
            Cudd_RecursiveDeref( dd, bCube );
        }
    }
    // complement the result if necessary
    bSum = Cudd_NotCond( bSum, !Abc_SopGetPhase(pSop) );
    Cudd_Deref( bSum );
    return bSum;
}

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

  Synopsis    [Converts the network from SOP to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkSopToBdd( Abc_Ntk_t * pNtk )
{
    Abc_Obj_t * pNode;
    DdManager * dd, * ddTemp = NULL;
    Vec_Int_t * vFanins = NULL;
    int nFaninsMax, i, k, iVar;
 
    assert( Abc_NtkHasSop(pNtk) ); 

    // start the functionality manager
    nFaninsMax = Abc_NtkGetFaninMax( pNtk );
    if ( nFaninsMax == 0 )
        printf( "Warning: The network has only constant nodes.\n" );
    dd = Cudd_Init( nFaninsMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );

    // start temporary manager for reordered local functions
    if ( nFaninsMax > 10 )
    {
        ddTemp = Cudd_Init( nFaninsMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
        Cudd_AutodynEnable( ddTemp,  CUDD_REORDER_SYMM_SIFT );
        vFanins = Vec_IntAlloc( nFaninsMax );
    }

    // convert each node from SOP to BDD
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        assert( pNode->pData );
        if ( Abc_ObjFaninNum(pNode) > 10 )
        {
            DdNode * pFunc = Abc_ConvertSopToBdd( ddTemp, (char *)pNode->pData, NULL );
            if ( pFunc == NULL )
            {
                printf( "Abc_NtkSopToBdd: Error while converting SOP into BDD.\n" );
                return 0;
            }
            Cudd_Ref( pFunc );
            // find variable mapping
            Vec_IntFill( vFanins, Abc_ObjFaninNum(pNode), -1 );
            for ( k = iVar = 0; k < nFaninsMax; k++ )
                if ( ddTemp->invperm[k] < Abc_ObjFaninNum(pNode) )
                    Vec_IntWriteEntry( vFanins, ddTemp->invperm[k], iVar++ );
            assert( iVar == Abc_ObjFaninNum(pNode) );
            // transfer to the main manager
            pNode->pData = Extra_TransferPermute( ddTemp, dd, pFunc, Vec_IntArray(vFanins) );
            Cudd_Ref( (DdNode *)pNode->pData );
            Cudd_RecursiveDeref( ddTemp, pFunc );
            // update variable order
            Vec_IntClear( vFanins );
            for ( k = 0; k < nFaninsMax; k++ )
                if ( ddTemp->invperm[k] < Abc_ObjFaninNum(pNode) )
                    Vec_IntPush( vFanins, Vec_IntEntry(&pNode->vFanins, ddTemp->invperm[k]) );
            for ( k = 0; k < Abc_ObjFaninNum(pNode); k++ )
                Vec_IntWriteEntry( &pNode->vFanins, k, Vec_IntEntry(vFanins, k) );
        }
        else
        {
            pNode->pData = Abc_ConvertSopToBdd( dd, (char *)pNode->pData, NULL );
            if ( pNode->pData == NULL )
            {
                printf( "Abc_NtkSopToBdd: Error while converting SOP into BDD.\n" );
                return 0;
            }
            Cudd_Ref( (DdNode *)pNode->pData );
        }
    }

    if ( ddTemp )
    {
//        printf( "Reorderings performed = %d.\n", Cudd_ReadReorderings(ddTemp) );
        Extra_StopManager( ddTemp );
    }
    Vec_IntFreeP( &vFanins );
    Mem_FlexStop( (Mem_Flex_t *)pNtk->pManFunc, 0 );
    pNtk->pManFunc = dd;

    // update the network type
    pNtk->ntkFunc = ABC_FUNC_BDD;
    return 1;
}




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

  Synopsis    [Converts the node from BDD to SOP representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
char * Abc_ConvertBddToSop( Mem_Flex_t * pMan, DdManager * dd, DdNode * bFuncOn, DdNode * bFuncOnDc, int nFanins, int fAllPrimes, Vec_Str_t * vCube, int fMode )
{
    int fVerify = 0;
    char * pSop;
    DdNode * bFuncNew, * bCover, * zCover, * zCover0, * zCover1;
    int nCubes, nCubes0, nCubes1, fPhase;

    assert( bFuncOn == bFuncOnDc || Cudd_bddLeq( dd, bFuncOn, bFuncOnDc ) );
    if ( Cudd_IsConstant(bFuncOn) || Cudd_IsConstant(bFuncOnDc) )
    {
        if ( fMode == -1 ) // if the phase is not known, write constant 1
            fMode = 1;
        Vec_StrFill( vCube, nFanins, '-' );
        Vec_StrPush( vCube, '\0' );
        if ( pMan )
            pSop = Mem_FlexEntryFetch( pMan, nFanins + 4 );
        else
            pSop = ABC_ALLOC( char, nFanins + 4 );
        if ( bFuncOn == Cudd_ReadOne(dd) )
            sprintf( pSop, "%s %d\n", vCube->pArray, fMode );
        else
            sprintf( pSop, "%s %d\n", vCube->pArray, !fMode );
        return pSop;
    }


    if ( fMode == -1 )
    { // try both phases
        assert( fAllPrimes == 0 );

        // get the ZDD of the negative polarity
        bCover = Cudd_zddIsop( dd, Cudd_Not(bFuncOnDc), Cudd_Not(bFuncOn), &zCover0 );
        Cudd_Ref( zCover0 );
        Cudd_Ref( bCover );
        Cudd_RecursiveDeref( dd, bCover );
        nCubes0 = Abc_CountZddCubes( dd, zCover0 );

        // get the ZDD of the positive polarity
        bCover = Cudd_zddIsop( dd, bFuncOn, bFuncOnDc, &zCover1 );
        Cudd_Ref( zCover1 );
        Cudd_Ref( bCover );
        Cudd_RecursiveDeref( dd, bCover );
        nCubes1 = Abc_CountZddCubes( dd, zCover1 );

        // compare the number of cubes
        if ( nCubes1 <= nCubes0 )
        { // use positive polarity
            nCubes = nCubes1;
            zCover = zCover1;
            Cudd_RecursiveDerefZdd( dd, zCover0 );
            fPhase = 1;
        }
        else
        { // use negative polarity
            nCubes = nCubes0;
            zCover = zCover0;
            Cudd_RecursiveDerefZdd( dd, zCover1 );
            fPhase = 0;
        }
    }
    else if ( fMode == 0 )
    {
        // get the ZDD of the negative polarity
        if ( fAllPrimes )
        {
            zCover = Extra_zddPrimes( dd, Cudd_Not(bFuncOnDc) ); 
            Cudd_Ref( zCover );
        }
        else
        {
            bCover = Cudd_zddIsop( dd, Cudd_Not(bFuncOnDc), Cudd_Not(bFuncOn), &zCover );
            Cudd_Ref( zCover );
            Cudd_Ref( bCover );
            Cudd_RecursiveDeref( dd, bCover );
        }
        nCubes = Abc_CountZddCubes( dd, zCover );
        fPhase = 0;
    }
    else if ( fMode == 1 )
    {
        // get the ZDD of the positive polarity
        if ( fAllPrimes )
        {
            zCover = Extra_zddPrimes( dd, bFuncOnDc ); 
            Cudd_Ref( zCover );
        }
        else
        {
            bCover = Cudd_zddIsop( dd, bFuncOn, bFuncOnDc, &zCover );
            Cudd_Ref( zCover );
            Cudd_Ref( bCover );
            Cudd_RecursiveDeref( dd, bCover );
        }
        nCubes = Abc_CountZddCubes( dd, zCover );
        fPhase = 1;
    }
    else
    {
        assert( 0 );
    }

    if ( nCubes > ABC_MAX_CUBES )
    {
        Cudd_RecursiveDerefZdd( dd, zCover );
        printf( "The number of cubes exceeded the predefined limit (%d).\n", ABC_MAX_CUBES );
        return NULL;
    }

    // allocate memory for the cover
    if ( pMan )
        pSop = Mem_FlexEntryFetch( pMan, (nFanins + 3) * nCubes + 1 );
    else 
        pSop = ABC_ALLOC( char, (nFanins + 3) * nCubes + 1 );
    pSop[(nFanins + 3) * nCubes] = 0;
    // create the SOP
    Vec_StrFill( vCube, nFanins, '-' );
    Vec_StrPush( vCube, '\0' );
    Abc_ConvertZddToSop( dd, zCover, pSop, nFanins, vCube, fPhase );
    Cudd_RecursiveDerefZdd( dd, zCover );

    // verify
    if ( fVerify )
    {
        bFuncNew = Abc_ConvertSopToBdd( dd, pSop, NULL );  Cudd_Ref( bFuncNew );
        if ( bFuncOn == bFuncOnDc )
        {
            if ( bFuncNew != bFuncOn )
                printf( "Verification failed.\n" );
        }
        else
        {
            if ( !Cudd_bddLeq(dd, bFuncOn, bFuncNew) || !Cudd_bddLeq(dd, bFuncNew, bFuncOnDc) )
                printf( "Verification failed.\n" );
        }
        Cudd_RecursiveDeref( dd, bFuncNew );
    }
    return pSop;
}

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

  Synopsis    [Converts the network from BDD to SOP representation.]

  Description [If the flag is set to 1, forces the direct phase of all covers.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkBddToSop( Abc_Ntk_t * pNtk, int fDirect )
{
    extern void Abc_NtkSortSops( Abc_Ntk_t * pNtk );
    Abc_Obj_t * pNode;
    Mem_Flex_t * pManNew;
    DdManager * dd = (DdManager *)pNtk->pManFunc;
    DdNode * bFunc;
    Vec_Str_t * vCube;
    int i, fMode;

    if ( fDirect )
        fMode = 1;
    else
        fMode = -1;

    assert( Abc_NtkHasBdd(pNtk) );
    if ( dd->size > 0 )
    Cudd_zddVarsFromBddVars( dd, 2 );
    // create the new manager
    pManNew = Mem_FlexStart();

    // go through the objects
    vCube = Vec_StrAlloc( 100 );
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        assert( pNode->pData );
        bFunc = (DdNode *)pNode->pData;
        pNode->pNext = (Abc_Obj_t *)Abc_ConvertBddToSop( pManNew, dd, bFunc, bFunc, Abc_ObjFaninNum(pNode), 0, vCube, fMode );
        if ( pNode->pNext == NULL )
        {
            Mem_FlexStop( pManNew, 0 );
            Abc_NtkCleanNext( pNtk );
//            printf( "Converting from BDDs to SOPs has failed.\n" );
            Vec_StrFree( vCube );
            return 0;
        }
    }
    Vec_StrFree( vCube );

    // update the network type
    pNtk->ntkFunc = ABC_FUNC_SOP;
    // set the new manager
    pNtk->pManFunc = pManNew;
    // transfer from next to data
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        Cudd_RecursiveDeref( dd, (DdNode *)pNode->pData );
        pNode->pData = pNode->pNext;
        pNode->pNext = NULL;
    }

    // check for remaining references in the package
    Extra_StopManager( dd );

    // reorder fanins and cubes to make SOPs more human-readable
    Abc_NtkSortSops( pNtk );
    return 1;
}


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

  Synopsis    [Derive the SOP from the ZDD representation of the cubes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ConvertZddToSop_rec( DdManager * dd, DdNode * zCover, char * pSop, int nFanins, Vec_Str_t * vCube, int fPhase, int * pnCubes )
{
    DdNode * zC0, * zC1, * zC2;
    int Index;

    if ( zCover == dd->zero )
        return;
    if ( zCover == dd->one )
    {
        char * pCube;
        pCube = pSop + (*pnCubes) * (nFanins + 3);
        sprintf( pCube, "%s %d\n", vCube->pArray, fPhase );
        (*pnCubes)++;
        return;
    }
    Index = zCover->index/2;
    assert( Index < nFanins );
    extraDecomposeCover( dd, zCover, &zC0, &zC1, &zC2 );
    vCube->pArray[Index] = '0';
    Abc_ConvertZddToSop_rec( dd, zC0, pSop, nFanins, vCube, fPhase, pnCubes );
    vCube->pArray[Index] = '1';
    Abc_ConvertZddToSop_rec( dd, zC1, pSop, nFanins, vCube, fPhase, pnCubes );
    vCube->pArray[Index] = '-';
    Abc_ConvertZddToSop_rec( dd, zC2, pSop, nFanins, vCube, fPhase, pnCubes );
}

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

  Synopsis    [Derive the BDD for the function in the cut.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_ConvertZddToSop( DdManager * dd, DdNode * zCover, char * pSop, int nFanins, Vec_Str_t * vCube, int fPhase )
{
    int nCubes = 0;
    Abc_ConvertZddToSop_rec( dd, zCover, pSop, nFanins, vCube, fPhase, &nCubes );
    return nCubes;
}


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

  Synopsis    [Computes the SOPs of the negative and positive phase of the node.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NodeBddToCnf( Abc_Obj_t * pNode, Mem_Flex_t * pMmMan, Vec_Str_t * vCube, int fAllPrimes, char ** ppSop0, char ** ppSop1 )
{
    assert( Abc_NtkHasBdd(pNode->pNtk) ); 
    *ppSop0 = Abc_ConvertBddToSop( pMmMan, (DdManager *)pNode->pNtk->pManFunc, (DdNode *)pNode->pData, (DdNode *)pNode->pData, Abc_ObjFaninNum(pNode), fAllPrimes, vCube, 0 );
    *ppSop1 = Abc_ConvertBddToSop( pMmMan, (DdManager *)pNode->pNtk->pManFunc, (DdNode *)pNode->pData, (DdNode *)pNode->pData, Abc_ObjFaninNum(pNode), fAllPrimes, vCube, 1 );
}


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

  Synopsis    [Removes complemented SOP covers.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkLogicMakeDirectSops( Abc_Ntk_t * pNtk )
{
    DdManager * dd;
    DdNode * bFunc;
    Vec_Str_t * vCube;
    Abc_Obj_t * pNode;
    int nFaninsMax, fFound, i;

    assert( Abc_NtkHasSop(pNtk) );

    // check if there are nodes with complemented SOPs
    fFound = 0;
    Abc_NtkForEachNode( pNtk, pNode, i )
        if ( !Abc_ObjIsBarBuf(pNode) && Abc_SopIsComplement((char *)pNode->pData) )
        {
            fFound = 1;
            break;
        }
    if ( !fFound )
        return;

    // start the BDD package
    nFaninsMax = Abc_NtkGetFaninMax( pNtk );
    if ( nFaninsMax == 0 )
        printf( "Warning: The network has only constant nodes.\n" );
    dd = Cudd_Init( nFaninsMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );

    // change the cover of negated nodes
    vCube = Vec_StrAlloc( 100 );
    Abc_NtkForEachNode( pNtk, pNode, i )
        if ( !Abc_ObjIsBarBuf(pNode) && Abc_SopIsComplement((char *)pNode->pData) )
        {
            bFunc = Abc_ConvertSopToBdd( dd, (char *)pNode->pData, NULL );  Cudd_Ref( bFunc );
            pNode->pData = Abc_ConvertBddToSop( (Mem_Flex_t *)pNtk->pManFunc, dd, bFunc, bFunc, Abc_ObjFaninNum(pNode), 0, vCube, 1 );
            Cudd_RecursiveDeref( dd, bFunc );
            assert( !Abc_SopIsComplement((char *)pNode->pData) );
        }
    Vec_StrFree( vCube );
    Extra_StopManager( dd );
}




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

  Synopsis    [Count the number of paths in the ZDD.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_CountZddCubes_rec( DdManager * dd, DdNode * zCover, int * pnCubes )
{
    DdNode * zC0, * zC1, * zC2;
    if ( zCover == dd->zero )
        return;
    if ( zCover == dd->one )
    {
        (*pnCubes)++;
        return;
    }
    if ( (*pnCubes) > ABC_MAX_CUBES )
        return;
    extraDecomposeCover( dd, zCover, &zC0, &zC1, &zC2 );
    Abc_CountZddCubes_rec( dd, zC0, pnCubes );
    Abc_CountZddCubes_rec( dd, zC1, pnCubes );
    Abc_CountZddCubes_rec( dd, zC2, pnCubes );
}

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

  Synopsis    [Count the number of paths in the ZDD.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_CountZddCubes( DdManager * dd, DdNode * zCover )
{
    int nCubes = 0;
    Abc_CountZddCubes_rec( dd, zCover, &nCubes );
    return nCubes;
}


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

  Synopsis    [Converts the network from SOP to AIG representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkSopToAig( Abc_Ntk_t * pNtk )
{
    Abc_Obj_t * pNode;
    Hop_Man_t * pMan;
    int i;

    assert( Abc_NtkHasSop(pNtk) ); 

    // make dist1-free and SCC-free
//    Abc_NtkMakeLegit( pNtk );

    // start the functionality manager
    pMan = Hop_ManStart();

    // convert each node from SOP to BDD
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        assert( pNode->pData );
        pNode->pData = Abc_ConvertSopToAig( pMan, (char *)pNode->pData );
        if ( pNode->pData == NULL )
        {
            Hop_ManStop( pMan );
            printf( "Abc_NtkSopToAig: Error while converting SOP into AIG.\n" );
            return 0;
        }
    }
    Mem_FlexStop( (Mem_Flex_t *)pNtk->pManFunc, 0 );
    pNtk->pManFunc = pMan;

    // update the network type
    pNtk->ntkFunc = ABC_FUNC_AIG;
    return 1;
}


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

  Synopsis    [Strashes one logic node using its SOP.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Hop_Obj_t * Abc_ConvertSopToAigInternal( Hop_Man_t * pMan, char * pSop )
{
    Hop_Obj_t * pAnd, * pSum;
    int i, Value, nFanins;
    char * pCube;
    // get the number of variables
    nFanins = Abc_SopGetVarNum(pSop);
    if ( Abc_SopIsExorType(pSop) )
    {
        pSum = Hop_ManConst0(pMan); 
        for ( i = 0; i < nFanins; i++ )
            pSum = Hop_Exor( pMan, pSum, Hop_IthVar(pMan,i) );
    }
    else
    {
        // go through the cubes of the node's SOP
        pSum = Hop_ManConst0(pMan); 
        Abc_SopForEachCube( pSop, nFanins, pCube )
        {
            // create the AND of literals
            pAnd = Hop_ManConst1(pMan);
            Abc_CubeForEachVar( pCube, Value, i )
            {
                if ( Value == '1' )
                    pAnd = Hop_And( pMan, pAnd, Hop_IthVar(pMan,i) );
                else if ( Value == '0' )
                    pAnd = Hop_And( pMan, pAnd, Hop_Not(Hop_IthVar(pMan,i)) );
            }
            // add to the sum of cubes
            pSum = Hop_Or( pMan, pSum, pAnd );
        }
    }
    // decide whether to complement the result
    if ( Abc_SopIsComplement(pSop) )
        pSum = Hop_Not(pSum);
    return pSum;
}

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

  Synopsis    [Converts the network from AIG to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Hop_Obj_t * Abc_ConvertSopToAig( Hop_Man_t * pMan, char * pSop )
{
    extern Hop_Obj_t * Dec_GraphFactorSop( Hop_Man_t * pMan, char * pSop );
    int fUseFactor = 1;
    // consider the constant node
    if ( Abc_SopGetVarNum(pSop) == 0 )
        return Hop_NotCond( Hop_ManConst1(pMan), Abc_SopIsConst0(pSop) );
    // decide when to use factoring
    if ( fUseFactor && Abc_SopGetVarNum(pSop) > 2 && Abc_SopGetCubeNum(pSop) > 1 && !Abc_SopIsExorType(pSop) )
        return Dec_GraphFactorSop( pMan, pSop );
    return Abc_ConvertSopToAigInternal( pMan, pSop );
}

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

  Synopsis    [Converts the network from AIG to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkAigToBdd( Abc_Ntk_t * pNtk )
{
    Abc_Obj_t * pNode;
    Hop_Man_t * pMan;
    DdNode * pFunc;
    DdManager * dd, * ddTemp = NULL;
    Vec_Int_t * vFanins = NULL;
    int nFaninsMax, i, k, iVar;

    assert( Abc_NtkHasAig(pNtk) ); 

    // start the functionality manager
    nFaninsMax = Abc_NtkGetFaninMax( pNtk );
    if ( nFaninsMax == 0 )
        printf( "Warning: The network has only constant nodes.\n" );

    dd = Cudd_Init( nFaninsMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );

    // start temporary manager for reordered local functions
    ddTemp = Cudd_Init( nFaninsMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
    Cudd_AutodynEnable( ddTemp,  CUDD_REORDER_SYMM_SIFT );
    vFanins = Vec_IntAlloc( nFaninsMax );

    // set the mapping of elementary AIG nodes into the elementary BDD nodes
    pMan = (Hop_Man_t *)pNtk->pManFunc;
    assert( Hop_ManPiNum(pMan) >= nFaninsMax ); 
    for ( i = 0; i < nFaninsMax; i++ )
        Hop_ManPi(pMan, i)->pData = Cudd_bddIthVar(ddTemp, i);

    // convert each node from SOP to BDD
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        pFunc = Abc_ConvertAigToBdd( ddTemp, (Hop_Obj_t *)pNode->pData );
        if ( pFunc == NULL )
        {
            printf( "Abc_NtkAigToBdd: Error while converting AIG into BDD.\n" );
            return 0;
        }
        Cudd_Ref( pFunc );
        // find variable mapping
        Vec_IntFill( vFanins, Abc_ObjFaninNum(pNode), -1 );
        for ( k = iVar = 0; k < nFaninsMax; k++ )
            if ( ddTemp->invperm[k] < Abc_ObjFaninNum(pNode) )
                Vec_IntWriteEntry( vFanins, ddTemp->invperm[k], iVar++ );
        assert( iVar == Abc_ObjFaninNum(pNode) );
        // transfer to the main manager
        pNode->pData = Extra_TransferPermute( ddTemp, dd, pFunc, Vec_IntArray(vFanins) );
        Cudd_Ref( (DdNode *)pNode->pData );
        Cudd_RecursiveDeref( ddTemp, pFunc );
        // update variable order
        Vec_IntClear( vFanins );
        for ( k = 0; k < nFaninsMax; k++ )
            if ( ddTemp->invperm[k] < Abc_ObjFaninNum(pNode) )
                Vec_IntPush( vFanins, Vec_IntEntry(&pNode->vFanins, ddTemp->invperm[k]) );
        for ( k = 0; k < Abc_ObjFaninNum(pNode); k++ )
            Vec_IntWriteEntry( &pNode->vFanins, k, Vec_IntEntry(vFanins, k) );
    }

//    printf( "Reorderings performed = %d.\n", Cudd_ReadReorderings(ddTemp) );
    Extra_StopManager( ddTemp );
    Vec_IntFreeP( &vFanins );
    Hop_ManStop( (Hop_Man_t *)pNtk->pManFunc );
    pNtk->pManFunc = dd;

    // update the network type
    pNtk->ntkFunc = ABC_FUNC_BDD;
    return 1;
}

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

  Synopsis    [Construct BDDs and mark AIG nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ConvertAigToBdd_rec1( DdManager * dd, Hop_Obj_t * pObj )
{
    assert( !Hop_IsComplement(pObj) );
    if ( !Hop_ObjIsNode(pObj) || Hop_ObjIsMarkA(pObj) )
        return;
    Abc_ConvertAigToBdd_rec1( dd, Hop_ObjFanin0(pObj) ); 
    Abc_ConvertAigToBdd_rec1( dd, Hop_ObjFanin1(pObj) );
    pObj->pData = Cudd_bddAnd( dd, (DdNode *)Hop_ObjChild0Copy(pObj), (DdNode *)Hop_ObjChild1Copy(pObj) ); 
    Cudd_Ref( (DdNode *)pObj->pData );
    assert( !Hop_ObjIsMarkA(pObj) ); // loop detection
    Hop_ObjSetMarkA( pObj );
}

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

  Synopsis    [Dereference BDDs and unmark AIG nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ConvertAigToBdd_rec2( DdManager * dd, Hop_Obj_t * pObj )
{
    assert( !Hop_IsComplement(pObj) );
    if ( !Hop_ObjIsNode(pObj) || !Hop_ObjIsMarkA(pObj) )
        return;
    Abc_ConvertAigToBdd_rec2( dd, Hop_ObjFanin0(pObj) ); 
    Abc_ConvertAigToBdd_rec2( dd, Hop_ObjFanin1(pObj) );
    Cudd_RecursiveDeref( dd, (DdNode *)pObj->pData );
    pObj->pData = NULL;
    assert( Hop_ObjIsMarkA(pObj) ); // loop detection
    Hop_ObjClearMarkA( pObj );
}

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

  Synopsis    [Converts the network from AIG to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
DdNode * Abc_ConvertAigToBdd( DdManager * dd, Hop_Obj_t * pRoot )
{
    DdNode * bFunc;
    // check the case of a constant
    if ( Hop_ObjIsConst1( Hop_Regular(pRoot) ) )
        return Cudd_NotCond( Cudd_ReadOne(dd), Hop_IsComplement(pRoot) );
    // construct BDD
    Abc_ConvertAigToBdd_rec1( dd, Hop_Regular(pRoot) );
    // hold on to the result
    bFunc = Cudd_NotCond( Hop_Regular(pRoot)->pData, Hop_IsComplement(pRoot) );  Cudd_Ref( bFunc );
    // dereference BDD
    Abc_ConvertAigToBdd_rec2( dd, Hop_Regular(pRoot) );
    // return the result
    Cudd_Deref( bFunc );
    return bFunc;
}



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

  Synopsis    [Converts the network from AIG to GIA representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ConvertAigToGia_rec1( Gia_Man_t * p, Hop_Obj_t * pObj )
{
    assert( !Hop_IsComplement(pObj) );
    if ( !Hop_ObjIsNode(pObj) || Hop_ObjIsMarkA(pObj) )
        return;
    Abc_ConvertAigToGia_rec1( p, Hop_ObjFanin0(pObj) ); 
    Abc_ConvertAigToGia_rec1( p, Hop_ObjFanin1(pObj) );
    pObj->iData = Gia_ManAppendAnd2( p, Hop_ObjChild0CopyI(pObj), Hop_ObjChild1CopyI(pObj) );
    assert( !Hop_ObjIsMarkA(pObj) ); // loop detection
    Hop_ObjSetMarkA( pObj );
}
void Abc_ConvertAigToGia_rec2( Hop_Obj_t * pObj )
{
    assert( !Hop_IsComplement(pObj) );
    if ( !Hop_ObjIsNode(pObj) || !Hop_ObjIsMarkA(pObj) )
        return;
    Abc_ConvertAigToGia_rec2( Hop_ObjFanin0(pObj) ); 
    Abc_ConvertAigToGia_rec2( Hop_ObjFanin1(pObj) );
    assert( Hop_ObjIsMarkA(pObj) ); // loop detection
    Hop_ObjClearMarkA( pObj );
}
int Abc_ConvertAigToGia( Gia_Man_t * p, Hop_Obj_t * pRoot )
{
    assert( !Hop_IsComplement(pRoot) );
    if ( Hop_ObjIsConst1( pRoot ) )
        return 1;
    Abc_ConvertAigToGia_rec1( p, pRoot );
    Abc_ConvertAigToGia_rec2( pRoot );
    return pRoot->iData;
}

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

  Synopsis    [Converts the network from AIG to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Gia_Man_t * Abc_NtkAigToGia( Abc_Ntk_t * p )
{
    Gia_Man_t * pNew;
    Hop_Man_t * pHopMan;
    Hop_Obj_t * pHopObj;
    Vec_Int_t * vMapping;
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pNode, * pFanin;
    int i, k, nObjs;
    assert( Abc_NtkIsAigLogic(p) );
    pHopMan = (Hop_Man_t *)p->pManFunc;
    // create new manager
    pNew = Gia_ManStart( 10000 );
    pNew->pName = Abc_UtilStrsav( Abc_NtkName(p) );
    pNew->pSpec = Abc_UtilStrsav( Abc_NtkSpec(p) );
    Abc_NtkCleanCopy( p );
    Hop_ManConst1(pHopMan)->iData = 1;
    // create primary inputs
    Abc_NtkForEachCi( p, pNode, i )
        pNode->iTemp = Gia_ManAppendCi(pNew);
    // find the number of objects
    nObjs = 1 + Abc_NtkCiNum(p) + Abc_NtkCoNum(p);
    Abc_NtkForEachNode( p, pNode, i )
        nObjs += Abc_ObjIsBarBuf(pNode) ? 1 : Hop_DagSize( (Hop_Obj_t *)pNode->pData );
    vMapping = Vec_IntStart( nObjs );
    // iterate through nodes used in the mapping
    vNodes = Abc_NtkDfs( p, 0 );
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
        {
            assert( !Abc_ObjFaninC0(pNode) );
            pNode->iTemp = Gia_ManAppendBuf( pNew, Abc_ObjFanin0(pNode)->iTemp );
            continue;
        }
        Abc_ObjForEachFanin( pNode, pFanin, k )
            Hop_ManPi(pHopMan, k)->iData = pFanin->iTemp;
        pHopObj = Hop_Regular( (Hop_Obj_t *)pNode->pData );
        if ( Hop_DagSize(pHopObj) > 0 )
        {
            assert( Abc_ObjFaninNum(pNode) <= Hop_ManPiNum(pHopMan) );
            Abc_ConvertAigToGia( pNew, pHopObj );
            if ( !Gia_ObjIsAnd(Gia_ManObj(pNew, Abc_Lit2Var(pHopObj->iData))) )
                continue;
            if ( Vec_IntEntry(vMapping, Abc_Lit2Var(pHopObj->iData)) )
                continue;
            Vec_IntWriteEntry( vMapping, Abc_Lit2Var(pHopObj->iData), Vec_IntSize(vMapping) );
            Vec_IntPush( vMapping, Abc_ObjFaninNum(pNode) );
            Abc_ObjForEachFanin( pNode, pFanin, k )
                Vec_IntPush( vMapping, Abc_Lit2Var(pFanin->iTemp)  );
            Vec_IntPush( vMapping, Abc_Lit2Var(pHopObj->iData) );
        }
        pNode->iTemp = Abc_LitNotCond( pHopObj->iData, Hop_IsComplement( (Hop_Obj_t *)pNode->pData ) );
    }
    Vec_PtrFree( vNodes );
    // create primary outputs
    Abc_NtkForEachCo( p, pNode, i )
        Gia_ManAppendCo( pNew, Abc_ObjFanin0(pNode)->iTemp );
    Gia_ManSetRegNum( pNew, Abc_NtkLatchNum(p) );
    // finish mapping 
    assert( Gia_ManObjNum(pNew) <= nObjs );
    assert( pNew->vMapping == NULL );
    pNew->vMapping = vMapping;
    return pNew;
}


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

  Synopsis    [Construct BDDs and mark AIG nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ConvertAigToAig_rec( Abc_Ntk_t * pNtkAig, Hop_Obj_t * pObj )
{
    assert( !Hop_IsComplement(pObj) );
    if ( !Hop_ObjIsNode(pObj) || Hop_ObjIsMarkA(pObj) )
        return;
    Abc_ConvertAigToAig_rec( pNtkAig, Hop_ObjFanin0(pObj) ); 
    Abc_ConvertAigToAig_rec( pNtkAig, Hop_ObjFanin1(pObj) );
    pObj->pData = Abc_AigAnd( (Abc_Aig_t *)pNtkAig->pManFunc, (Abc_Obj_t *)Hop_ObjChild0Copy(pObj), (Abc_Obj_t *)Hop_ObjChild1Copy(pObj) ); 
    assert( !Hop_ObjIsMarkA(pObj) ); // loop detection
    Hop_ObjSetMarkA( pObj );
}

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

  Synopsis    [Converts the network from AIG to BDD representation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Obj_t * Abc_ConvertAigToAig( Abc_Ntk_t * pNtkAig, Abc_Obj_t * pObjOld )
{
    Hop_Man_t * pHopMan;
    Hop_Obj_t * pRoot;
    Abc_Obj_t * pFanin;
    int i;
    // get the local AIG
    pHopMan = (Hop_Man_t *)pObjOld->pNtk->pManFunc;
    pRoot = (Hop_Obj_t *)pObjOld->pData;
    // check the case of a constant
    if ( Hop_ObjIsConst1( Hop_Regular(pRoot) ) )
        return Abc_ObjNotCond( Abc_AigConst1(pNtkAig), Hop_IsComplement(pRoot) );
    // assign the fanin nodes
    Abc_ObjForEachFanin( pObjOld, pFanin, i )
    {
        assert( pFanin->pCopy != NULL );
        Hop_ManPi(pHopMan, i)->pData = pFanin->pCopy;
    }
    // construct the AIG
    Abc_ConvertAigToAig_rec( pNtkAig, Hop_Regular(pRoot) );
    Hop_ConeUnmark_rec( Hop_Regular(pRoot) );
    // return the result
    return Abc_ObjNotCond( (Abc_Obj_t *)Hop_Regular(pRoot)->pData, Hop_IsComplement(pRoot) );  
}


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

  Synopsis    [Unmaps the network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkMapToSop( Abc_Ntk_t * pNtk )
{
    extern void * Abc_FrameReadLibGen();                    
    Abc_Obj_t * pNode;
    char * pSop;
    int i;

    assert( Abc_NtkHasMapping(pNtk) );
    // update the functionality manager
    assert( pNtk->pManFunc == Abc_FrameReadLibGen() );
    pNtk->pManFunc = Mem_FlexStart();
    // update the nodes
    Abc_NtkForEachNode( pNtk, pNode, i )
    {
        if ( Abc_ObjIsBarBuf(pNode) )
            continue;
        pSop = Mio_GateReadSop((Mio_Gate_t *)pNode->pData);
        assert( Abc_SopGetVarNum(pSop) == Abc_ObjFaninNum(pNode) );
        pNode->pData = Abc_SopRegister( (Mem_Flex_t *)pNtk->pManFunc, pSop );
    }
    pNtk->ntkFunc  = ABC_FUNC_SOP;
    return 1;
}

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

  Synopsis    [Converts SOP functions into BLIF-MV functions.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkSopToBlifMv( Abc_Ntk_t * pNtk )
{
    return 1;
}

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

  Synopsis    [Convers logic network to the SOP form.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkToSop( Abc_Ntk_t * pNtk, int fDirect )
{
    assert( !Abc_NtkIsStrash(pNtk) );
    if ( Abc_NtkHasSop(pNtk) )
    {
        if ( !fDirect )
            return 1;
        if ( !Abc_NtkSopToBdd(pNtk) )
            return 0;
        return Abc_NtkBddToSop(pNtk, fDirect);
    }
    if ( Abc_NtkHasMapping(pNtk) )
        return Abc_NtkMapToSop(pNtk);
    if ( Abc_NtkHasBdd(pNtk) )
        return Abc_NtkBddToSop(pNtk, fDirect);
    if ( Abc_NtkHasAig(pNtk) )
    {
        if ( !Abc_NtkAigToBdd(pNtk) )
            return 0;
        return Abc_NtkBddToSop(pNtk, fDirect);
    }
    assert( 0 );
    return 0;
}

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

  Synopsis    [Convers logic network to the SOP form.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkToBdd( Abc_Ntk_t * pNtk )
{
    assert( !Abc_NtkIsStrash(pNtk) );
    if ( Abc_NtkHasBdd(pNtk) )
        return 1;
    if ( Abc_NtkHasMapping(pNtk) )
    {
        Abc_NtkMapToSop(pNtk);
        return Abc_NtkSopToBdd(pNtk);
    }
    if ( Abc_NtkHasSop(pNtk) )
    {
        Abc_NtkSopToAig(pNtk);
        return Abc_NtkAigToBdd(pNtk);
    }
    if ( Abc_NtkHasAig(pNtk) )
        return Abc_NtkAigToBdd(pNtk);
    assert( 0 );
    return 0;
}

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

  Synopsis    [Convers logic network to the SOP form.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkToAig( Abc_Ntk_t * pNtk )
{
    assert( !Abc_NtkIsStrash(pNtk) );
    if ( Abc_NtkHasAig(pNtk) )
        return 1;
    if ( Abc_NtkHasMapping(pNtk) )
    {
        Abc_NtkMapToSop(pNtk);
        return Abc_NtkSopToAig(pNtk);
    }
    if ( Abc_NtkHasBdd(pNtk) )
    {
        if ( !Abc_NtkBddToSop(pNtk,0) )
            return 0;
        return Abc_NtkSopToAig(pNtk);
    }
    if ( Abc_NtkHasSop(pNtk) )
        return Abc_NtkSopToAig(pNtk);
    assert( 0 );
    return 0;
}


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


ABC_NAMESPACE_IMPL_END