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

  FileName    [giaFanout.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Scalable AIG package.]

  Synopsis    []

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "gia.h"

ABC_NAMESPACE_IMPL_START


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

// 0: first iFan
// 1: prev iFan0
// 2: prev iFan1
// 3: next iFan0
// 4: next iFan1

static inline int   Gia_FanoutCreate( int FanId, int Num )    { assert( Num < 2 ); return (FanId << 1) | Num;   } 
static inline int * Gia_FanoutObj( int * pData, int ObjId )   { return pData + 5*ObjId;                         }
static inline int * Gia_FanoutPrev( int * pData, int iFan )   { return pData + 5*(iFan >> 1) + 1 + (iFan & 1);  }
static inline int * Gia_FanoutNext( int * pData, int iFan )   { return pData + 5*(iFan >> 1) + 3 + (iFan & 1);  }

// these two procedures are only here for the use inside the iterator
static inline int     Gia_ObjFanout0Int( Gia_Man_t * p, int ObjId )  { assert(ObjId < p->nFansAlloc);  return p->pFanData[5*ObjId];                         }
static inline int     Gia_ObjFanoutNext( Gia_Man_t * p, int iFan )   { assert(iFan/2 < p->nFansAlloc); return p->pFanData[5*(iFan >> 1) + 3 + (iFan & 1)];  }
// iterator over the fanouts
#define Gia_ObjForEachFanout( p, pObj, pFanout, iFan, i )                       \
    for ( assert(p->pFanData), i = 0; (i < (int)(pObj)->nRefs) &&               \
          (((iFan) = i? Gia_ObjFanoutNext(p, iFan) : Gia_ObjFanout0Int(p, Gia_ObjId(p, pObj))), 1) && \
          (((pFanout) = Gia_ManObj(p, iFan>>1)), 1); i++ )

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

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

  Synopsis    [Create fanout for all objects in the manager.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManFanoutStart( Gia_Man_t * p )
{
    Gia_Obj_t * pObj;
    int i;
    // allocate fanout datastructure
    assert( p->pFanData == NULL );
    p->nFansAlloc = 2 * Gia_ManObjNum(p);
    if ( p->nFansAlloc < (1<<12) )
        p->nFansAlloc = (1<<12);
    p->pFanData = ABC_ALLOC( int, 5 * p->nFansAlloc );
    memset( p->pFanData, 0, sizeof(int) * 5 * p->nFansAlloc );
    // add fanouts for all objects
    Gia_ManForEachObj( p, pObj, i )
    {
        if ( Gia_ObjChild0(pObj) )
            Gia_ObjAddFanout( p, Gia_ObjFanin0(pObj), pObj );
        if ( Gia_ObjChild1(pObj) )
            Gia_ObjAddFanout( p, Gia_ObjFanin1(pObj), pObj );
    }
}

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

  Synopsis    [Deletes fanout for all objects in the manager.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManFanoutStop( Gia_Man_t * p )
{
    assert( p->pFanData != NULL );
    ABC_FREE( p->pFanData );
    p->nFansAlloc = 0;
}

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

  Synopsis    [Adds fanout (pFanout) of node (pObj).]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ObjAddFanout( Gia_Man_t * p, Gia_Obj_t * pObj, Gia_Obj_t * pFanout )
{
    int iFan, * pFirst, * pPrevC, * pNextC, * pPrev, * pNext;
    assert( p->pFanData );
    assert( !Gia_IsComplement(pObj) && !Gia_IsComplement(pFanout) );
    assert( Gia_ObjId(p, pFanout) > 0 );
    if ( Gia_ObjId(p, pObj) >= p->nFansAlloc || Gia_ObjId(p, pFanout) >= p->nFansAlloc )
    {
        int nFansAlloc = 2 * ABC_MAX( Gia_ObjId(p, pObj), Gia_ObjId(p, pFanout) ); 
        p->pFanData = ABC_REALLOC( int, p->pFanData, 5 * nFansAlloc );
        memset( p->pFanData + 5 * p->nFansAlloc, 0, sizeof(int) * 5 * (nFansAlloc - p->nFansAlloc) );
        p->nFansAlloc = nFansAlloc;
    }
    assert( Gia_ObjId(p, pObj) < p->nFansAlloc && Gia_ObjId(p, pFanout) < p->nFansAlloc );
    iFan   = Gia_FanoutCreate( Gia_ObjId(p, pFanout), Gia_ObjWhatFanin(pFanout, pObj) );
    pPrevC = Gia_FanoutPrev( p->pFanData, iFan );
    pNextC = Gia_FanoutNext( p->pFanData, iFan );
    pFirst = Gia_FanoutObj( p->pFanData, Gia_ObjId(p, pObj) );
    if ( *pFirst == 0 )
    {
        *pFirst = iFan;
        *pPrevC = iFan;
        *pNextC = iFan;
    }
    else
    {
        pPrev = Gia_FanoutPrev( p->pFanData, *pFirst );
        pNext = Gia_FanoutNext( p->pFanData, *pPrev );
        assert( *pNext == *pFirst );
        *pPrevC = *pPrev;
        *pNextC = *pFirst;
        *pPrev  = iFan;
        *pNext  = iFan;
    }
}

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

  Synopsis    [Removes fanout (pFanout) of node (pObj).]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ObjRemoveFanout( Gia_Man_t * p, Gia_Obj_t * pObj, Gia_Obj_t * pFanout )
{
    int iFan, * pFirst, * pPrevC, * pNextC, * pPrev, * pNext;
    assert( p->pFanData && Gia_ObjId(p, pObj) < p->nFansAlloc && Gia_ObjId(p, pFanout) < p->nFansAlloc );
    assert( !Gia_IsComplement(pObj) && !Gia_IsComplement(pFanout) );
    assert( Gia_ObjId(p, pFanout) > 0 );
    iFan   = Gia_FanoutCreate( Gia_ObjId(p, pFanout), Gia_ObjWhatFanin(pFanout, pObj) );
    pPrevC = Gia_FanoutPrev( p->pFanData, iFan );
    pNextC = Gia_FanoutNext( p->pFanData, iFan );
    pPrev  = Gia_FanoutPrev( p->pFanData, *pNextC );
    pNext  = Gia_FanoutNext( p->pFanData, *pPrevC );
    assert( *pPrev == iFan );
    assert( *pNext == iFan );
    pFirst = Gia_FanoutObj( p->pFanData, Gia_ObjId(p, pObj) );
    assert( *pFirst > 0 );
    if ( *pFirst == iFan )
    {
        if ( *pNextC == iFan )
        {
            *pFirst = 0;
            *pPrev  = 0;
            *pNext  = 0;
            *pPrevC = 0;
            *pNextC = 0;
            return;
        }
        *pFirst = *pNextC;
    }
    *pPrev  = *pPrevC;
    *pNext  = *pNextC;
    *pPrevC = 0;
    *pNextC = 0;
}

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


ABC_NAMESPACE_IMPL_END

