wnnsc.c

主要进行大规模的电路综合

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

  FileName    [wnNsc.c]

  PackageName [MVSIS 2.0: Multi-valued logic synthesis system.]

  Synopsis    [Prepares the windows for NSC-flexibility computation.]

  Author      [MVSIS Group]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - February 1, 2003.]

  Revision    [$Id: wnNsc.c,v 1.2 2003/05/27 23:14:54 alanmi Exp $]

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

#include "wnInt.h"

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

static bool Wn_WindowPrepareHasReconv( Wn_Window_t * pWnd, Ntk_Node_t * pNode );
static void Wn_WindowPrepareHasReconv_rec( Ntk_Node_t * pNode );

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFITIONS                           ///
////////////////////////////////////////////////////////////////////////

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

  Synopsis    [Prepares the special nodes for NSC flexibility computation.]

  Description [Detects all the ND nodes that have reconvergent fanout
  for at least one root of the window. The nodes are collected by level
  from outputs.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Wn_WindowPrepareNsc( Wn_Window_t * pWnd )
{
    Mvr_Relation_t * pMvr;
    Ntk_Node_t * pNode;
    int Level;

    // levelize the window nodes starting from the leaves
    Wn_WindowLevelizeNodes( pWnd, 0 );

    // go through the nodes and add special nodes them to the special list
    Ntk_NetworkStartSpecial( pWnd->pNet );
    for ( Level = 0; Level <= pWnd->pNet->nLevels; Level++ )
        Ntk_NetworkForEachNodeSpecialByLevel( pWnd->pNet, Level, pNode )
        {
            pMvr = Ntk_NodeReadFuncMvr( pNode );
            if ( Mvr_RelationIsND( pMvr ) && Wn_WindowPrepareHasReconv(pWnd,pNode) )
                Ntk_NetworkAddToSpecial( pNode );
        }

    // move the nodes from the special list to the special array
    pWnd->nSpecials = Ntk_NetworkCountSpecial( pWnd->pNet );
    pWnd->ppSpecials = ALLOC( Ntk_Node_t *, pWnd->nSpecials );
    Ntk_NetworkCreateArrayFromSpecial( pWnd->pNet, pWnd->ppSpecials );
}

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

  Synopsis    [Returns 1 if the node has reconvergence to at least one root.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
bool Wn_WindowPrepareHasReconv( Wn_Window_t * pWnd, Ntk_Node_t * pStart )
{
    Ntk_Node_t * pNode;
    int i;

    // set the traversal ID for this traversal
    Ntk_NetworkIncrementTravId( pWnd->pNet );
    // mark the leaves and set their visit counters to 0
    for ( i = 0; i < pWnd->nRoots; i++ )
    {
        pNode = pWnd->ppRoots[i];
        Ntk_NodeSetTravIdCurrent( pNode );
        pNode->pData = NULL;
    }
    // mark the currently selected special nodes
    Ntk_NetworkForEachNodeSpecial( pWnd->pNet, pNode )
    {
        Ntk_NodeSetTravIdCurrent( pNode );
        pNode->pData = NULL;
    }

    // recursively visit the fanouts of the node
    Wn_WindowPrepareHasReconv_rec( pStart );

    // check if at least one of the nodes has the counter larger than 1
    for ( i = 0; i < pWnd->nRoots; i++ )
    {
        pNode = pWnd->ppRoots[i];
        if ( ((int)pNode->pData) > 1 )
            return 1;
    }
    Ntk_NetworkForEachNodeSpecial( pWnd->pNet, pNode )
    {
        if ( ((int)pNode->pData) > 1 )
            return 1;
    }
    // otherwise, the node has no reconvergence
    return 0;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Wn_WindowPrepareHasReconv_rec( Ntk_Node_t * pNode )
{
    Ntk_Node_t * pFanout;
    Ntk_Pin_t * pLink;

    if ( Ntk_NodeIsTravIdCurrent(pNode) ) // visited node
    {
        pNode->pData = (char *)( ((int)pNode->pData) + 1 );
        return;
    }
    assert( !Ntk_NodeIsCo(pNode) ); // otherwise, the window is wrong
    // visit the transitive fanout
    Ntk_NodeForEachFanout( pNode, pLink, pFanout )
        Wn_WindowPrepareHasReconv_rec( pFanout );
}

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