/**CFile****************************************************************
FileName [resDivs.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Resynthesis package.]
Synopsis [Collect divisors for the given window.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - January 15, 2007.]
Revision [$Id: resDivs.c,v 1.00 2007/01/15 00:00:00 alanmi Exp $]
***********************************************************************/
#include "base/abc/abc.h"
#include "resInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static void Res_WinMarkTfi( Res_Win_t * p );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Adds candidate divisors of the node to its window.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Res_WinDivisors( Res_Win_t * p, int nLevDivMax )
{
Abc_Obj_t * pObj, * pFanout, * pFanin;
int k, f, m;
// set the maximum level of the divisors
p->nLevDivMax = nLevDivMax;
// mark the TFI with the current trav ID
Abc_NtkIncrementTravId( p->pNode->pNtk );
Res_WinMarkTfi( p );
// mark with the current trav ID those nodes that should not be divisors:
// (1) the node and its TFO
// (2) the MFFC of the node
// (3) the node's fanins (these are treated as a special case)
Abc_NtkIncrementTravId( p->pNode->pNtk );
Res_WinSweepLeafTfo_rec( p->pNode, p->nLevDivMax );
Res_WinVisitMffc( p->pNode );
Abc_ObjForEachFanin( p->pNode, pObj, k )
Abc_NodeSetTravIdCurrent( pObj );
// at this point the nodes are marked with two trav IDs:
// nodes to be collected as divisors are marked with previous trav ID
// nodes to be avoided as divisors are marked with current trav ID
// start collecting the divisors
Vec_PtrClear( p->vDivs );
Vec_PtrForEachEntry( Abc_Obj_t *, p->vLeaves, pObj, k )
{
assert( (int)pObj->Level >= p->nLevLeafMin );
if ( !Abc_NodeIsTravIdPrevious(pObj) )
continue;
if ( (int)pObj->Level > p->nLevDivMax )
continue;
Vec_PtrPush( p->vDivs, pObj );
}
// add the internal nodes to the data structure
Vec_PtrForEachEntry( Abc_Obj_t *, p->vNodes, pObj, k )
{
if ( !Abc_NodeIsTravIdPrevious(pObj) )
continue;
if ( (int)pObj->Level > p->nLevDivMax )
continue;
Vec_PtrPush( p->vDivs, pObj );
}
// explore the fanouts of already collected divisors
p->nDivsPlus = 0;
Vec_PtrForEachEntry( Abc_Obj_t *, p->vDivs, pObj, k )
{
// consider fanouts of this node
Abc_ObjForEachFanout( pObj, pFanout, f )
{
// stop if there are too many fanouts
if ( f > 20 )
break;
// skip nodes that are already added
if ( Abc_NodeIsTravIdPrevious(pFanout) )
continue;
// skip nodes in the TFO or in the MFFC of node
if ( Abc_NodeIsTravIdCurrent(pFanout) )
continue;
// skip COs
if ( !Abc_ObjIsNode(pFanout) )
continue;
// skip nodes with large level
if ( (int)pFanout->Level > p->nLevDivMax )
continue;
// skip nodes whose fanins are not divisors
Abc_ObjForEachFanin( pFanout, pFanin, m )
if ( !Abc_NodeIsTravIdPrevious(pFanin) )
break;
if ( m < Abc_ObjFaninNum(pFanout) )
continue;
// add the node to the divisors
Vec_PtrPush( p->vDivs, pFanout );
Vec_PtrPush( p->vNodes, pFanout );
Abc_NodeSetTravIdPrevious( pFanout );
p->nDivsPlus++;
}
}
/*
printf( "Node level = %d. ", Abc_ObjLevel(p->pNode) );
Vec_PtrForEachEntryStart( Abc_Obj_t *, p->vDivs, pObj, k, Vec_PtrSize(p->vDivs)-p->nDivsPlus )
printf( "%d ", Abc_ObjLevel(pObj) );
printf( "\n" );
*/
//printf( "%d ", p->nDivsPlus );
}
/**Function*************************************************************
Synopsis [Marks the TFI cone of the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Res_WinMarkTfi_rec( Res_Win_t * p, Abc_Obj_t * pObj )
{
Abc_Obj_t * pFanin;
int i;
if ( Abc_NodeIsTravIdCurrent(pObj) )
return;
Abc_NodeSetTravIdCurrent( pObj );
assert( Abc_ObjIsNode(pObj) );
// visit the fanins of the node
Abc_ObjForEachFanin( pObj, pFanin, i )
Res_WinMarkTfi_rec( p, pFanin );
}
/**Function*************************************************************
Synopsis [Marks the TFI cone of the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Res_WinMarkTfi( Res_Win_t * p )
{
Abc_Obj_t * pObj;
int i;
// mark the leaves
Vec_PtrForEachEntry( Abc_Obj_t *, p->vLeaves, pObj, i )
Abc_NodeSetTravIdCurrent( pObj );
// start from the node
Res_WinMarkTfi_rec( p, p->pNode );
}
/**Function*************************************************************
Synopsis [Marks the TFO of the collected nodes up to the given level.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Res_WinSweepLeafTfo_rec( Abc_Obj_t * pObj, int nLevelLimit )
{
Abc_Obj_t * pFanout;
int i;
if ( Abc_ObjIsCo(pObj) || (int)pObj->Level > nLevelLimit )
return;
if ( Abc_NodeIsTravIdCurrent(pObj) )
return;
Abc_NodeSetTravIdCurrent( pObj );
Abc_ObjForEachFanout( pObj, pFanout, i )
Res_WinSweepLeafTfo_rec( pFanout, nLevelLimit );
}
/**Function*************************************************************
Synopsis [Dereferences the node's MFFC.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Res_NodeDeref_rec( Abc_Obj_t * pNode )
{
Abc_Obj_t * pFanin;
int i, Counter = 1;
if ( Abc_ObjIsCi(pNode) )
return 0;
Abc_NodeSetTravIdCurrent( pNode );
Abc_ObjForEachFanin( pNode, pFanin, i )
{
assert( pFanin->vFanouts.nSize > 0 );
if ( --pFanin->vFanouts.nSize == 0 )
Counter += Res_NodeDeref_rec( pFanin );
}
return Counter;
}
/**Function*************************************************************
Synopsis [References the node's MFFC.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Res_NodeRef_rec( Abc_Obj_t * pNode )
{
Abc_Obj_t * pFanin;
int i, Counter = 1;
if ( Abc_ObjIsCi(pNode) )
return 0;
Abc_ObjForEachFanin( pNode, pFanin, i )
{
if ( pFanin->vFanouts.nSize++ == 0 )
Counter += Res_NodeRef_rec( pFanin );
}
return Counter;
}
/**Function*************************************************************
Synopsis [Labels MFFC of the node with the current trav ID.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Res_WinVisitMffc( Abc_Obj_t * pNode )
{
int Count1, Count2;
assert( Abc_ObjIsNode(pNode) );
// dereference the node (mark with the current trav ID)
Count1 = Res_NodeDeref_rec( pNode );
// reference it back
Count2 = Res_NodeRef_rec( pNode );
assert( Count1 == Count2 );
return Count1;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END