src/sat/fraig/fraigFanout.c

Go to the documentation of this file.

#include "fraigInt.h"

#ifdef FRAIG_ENABLE_FANOUTS



void Fraig_NodeAddFaninFanout( Fraig_Node_t * pFanin, Fraig_Node_t * pFanout )
{
    Fraig_Node_t * pPivot;

    // pFanins is a fanin of pFanout
    assert( !Fraig_IsComplement(pFanin) );
    assert( !Fraig_IsComplement(pFanout) );
    assert( Fraig_Regular(pFanout->p1) == pFanin || Fraig_Regular(pFanout->p2) == pFanin );

    pPivot = pFanin->pFanPivot;
    if ( pPivot == NULL )
    {
        pFanin->pFanPivot = pFanout;
        return;
    }

    if ( Fraig_Regular(pPivot->p1) == pFanin )
    {
        if ( Fraig_Regular(pFanout->p1) == pFanin )
        {
            pFanout->pFanFanin1 = pPivot->pFanFanin1;
            pPivot->pFanFanin1  = pFanout;
        }
        else // if ( Fraig_Regular(pFanout->p2) == pFanin )
        {
            pFanout->pFanFanin2 = pPivot->pFanFanin1;
            pPivot->pFanFanin1  = pFanout;
        }
    }
    else // if ( Fraig_Regular(pPivot->p2) == pFanin )
    {
        assert( Fraig_Regular(pPivot->p2) == pFanin );
        if ( Fraig_Regular(pFanout->p1) == pFanin )
        {
            pFanout->pFanFanin1 = pPivot->pFanFanin2;
            pPivot->pFanFanin2  = pFanout;
        }
        else // if ( Fraig_Regular(pFanout->p2) == pFanin )
        {
            pFanout->pFanFanin2 = pPivot->pFanFanin2;
            pPivot->pFanFanin2  = pFanout;
        }
    }
}

void Fraig_NodeRemoveFaninFanout( Fraig_Node_t * pFanin, Fraig_Node_t * pFanoutToRemove )
{
    Fraig_Node_t * pFanout, * pFanout2, ** ppFanList;
    // start the linked list of fanouts
    ppFanList = &pFanin->pFanPivot; 
    // go through the fanouts
    Fraig_NodeForEachFanoutSafe( pFanin, pFanout, pFanout2 )
    {
        // skip the fanout-to-remove
        if ( pFanout == pFanoutToRemove )
            continue;
        // add useful fanouts to the list
        *ppFanList = pFanout;
        ppFanList = Fraig_NodeReadNextFanoutPlace( pFanin, pFanout );
    }
    *ppFanList = NULL;
}

void Fraig_NodeTransferFanout( Fraig_Node_t * pNodeFrom, Fraig_Node_t * pNodeTo )
{
    Fraig_Node_t * pFanout;
    assert( pNodeTo->pFanPivot == NULL );
    assert( pNodeTo->pFanFanin1 == NULL );
    assert( pNodeTo->pFanFanin2 == NULL );
    // go through the fanouts and update their fanins
    Fraig_NodeForEachFanout( pNodeFrom, pFanout )
    {
        if ( Fraig_Regular(pFanout->p1) == pNodeFrom )
            pFanout->p1 = Fraig_NotCond( pNodeTo, Fraig_IsComplement(pFanout->p1) );
        else if ( Fraig_Regular(pFanout->p2) == pNodeFrom )
            pFanout->p2 = Fraig_NotCond( pNodeTo, Fraig_IsComplement(pFanout->p2) );            
    }
    // move the pointers
    pNodeTo->pFanPivot  = pNodeFrom->pFanPivot;  
    pNodeTo->pFanFanin1 = pNodeFrom->pFanFanin1; 
    pNodeTo->pFanFanin2 = pNodeFrom->pFanFanin2;
    pNodeFrom->pFanPivot  = NULL; 
    pNodeFrom->pFanFanin1 = NULL; 
    pNodeFrom->pFanFanin2 = NULL;  
}

int Fraig_NodeGetFanoutNum( Fraig_Node_t * pNode )
{
    Fraig_Node_t * pFanout;
    int Counter = 0;
    Fraig_NodeForEachFanout( pNode, pFanout )
        Counter++;
    return Counter;
}


#endif

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