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/**CFile****************************************************************
FileName [abcMerge.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Network and node package.]
Synopsis [LUT merging algorithm.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: abcMerge.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "base/abc/abc.h"
#include "aig/aig/aig.h"
#include "opt/nwk/nwkMerge.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Marks the fanins of the node with the current trav ID.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkMarkFanins_rec( Abc_Obj_t * pLut, int nLevMin )
{
Abc_Obj_t * pNext;
int i;
if ( !Abc_ObjIsNode(pLut) )
return;
if ( Abc_NodeIsTravIdCurrent( pLut ) )
return;
Abc_NodeSetTravIdCurrent( pLut );
if ( Abc_ObjLevel(pLut) < nLevMin )
return;
Abc_ObjForEachFanin( pLut, pNext, i )
Abc_NtkMarkFanins_rec( pNext, nLevMin );
}
/**Function*************************************************************
Synopsis [Marks the fanouts of the node with the current trav ID.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkMarkFanouts_rec( Abc_Obj_t * pLut, int nLevMax, int nFanMax )
{
Abc_Obj_t * pNext;
int i;
if ( !Abc_ObjIsNode(pLut) )
return;
if ( Abc_NodeIsTravIdCurrent( pLut ) )
return;
Abc_NodeSetTravIdCurrent( pLut );
if ( Abc_ObjLevel(pLut) > nLevMax )
return;
if ( Abc_ObjFanoutNum(pLut) > nFanMax )
return;
Abc_ObjForEachFanout( pLut, pNext, i )
Abc_NtkMarkFanouts_rec( pNext, nLevMax, nFanMax );
}
/**Function*************************************************************
Synopsis [Collects the circle of nodes around the given set.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkCollectCircle( Vec_Ptr_t * vStart, Vec_Ptr_t * vNext, int nFanMax )
{
Abc_Obj_t * pObj, * pNext;
int i, k;
Vec_PtrClear( vNext );
Vec_PtrForEachEntry( Abc_Obj_t *, vStart, pObj, i )
{
Abc_ObjForEachFanin( pObj, pNext, k )
{
if ( !Abc_ObjIsNode(pNext) )
continue;
if ( Abc_NodeIsTravIdCurrent( pNext ) )
continue;
Abc_NodeSetTravIdCurrent( pNext );
Vec_PtrPush( vNext, pNext );
}
Abc_ObjForEachFanout( pObj, pNext, k )
{
if ( !Abc_ObjIsNode(pNext) )
continue;
if ( Abc_NodeIsTravIdCurrent( pNext ) )
continue;
Abc_NodeSetTravIdCurrent( pNext );
if ( Abc_ObjFanoutNum(pNext) > nFanMax )
continue;
Vec_PtrPush( vNext, pNext );
}
}
}
/**Function*************************************************************
Synopsis [Collects the circle of nodes removes from the given one.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkCollectNonOverlapCands( Abc_Obj_t * pLut, Vec_Ptr_t * vStart, Vec_Ptr_t * vNext, Vec_Ptr_t * vCands, Nwk_LMPars_t * pPars )
{
Vec_Ptr_t * vTemp;
Abc_Obj_t * pObj;
int i, k;
Vec_PtrClear( vCands );
if ( pPars->nMaxSuppSize - Abc_ObjFaninNum(pLut) <= 1 )
return;
// collect nodes removed by this distance
assert( pPars->nMaxDistance > 0 );
Vec_PtrClear( vStart );
Vec_PtrPush( vStart, pLut );
Abc_NtkIncrementTravId( pLut->pNtk );
Abc_NodeSetTravIdCurrent( pLut );
for ( i = 1; i <= pPars->nMaxDistance; i++ )
{
Abc_NtkCollectCircle( vStart, vNext, pPars->nMaxFanout );
vTemp = vStart;
vStart = vNext;
vNext = vTemp;
// collect the nodes in vStart
Vec_PtrForEachEntry( Abc_Obj_t *, vStart, pObj, k )
Vec_PtrPush( vCands, pObj );
}
// mark the TFI/TFO nodes
Abc_NtkIncrementTravId( pLut->pNtk );
if ( pPars->fUseTfiTfo )
Abc_NodeSetTravIdCurrent( pLut );
else
{
Abc_NodeSetTravIdPrevious( pLut );
Abc_NtkMarkFanins_rec( pLut, Abc_ObjLevel(pLut) - pPars->nMaxDistance );
Abc_NodeSetTravIdPrevious( pLut );
Abc_NtkMarkFanouts_rec( pLut, Abc_ObjLevel(pLut) + pPars->nMaxDistance, pPars->nMaxFanout );
}
// collect nodes satisfying the following conditions:
// - they are close enough in terms of distance
// - they are not in the TFI/TFO of the LUT
// - they have no more than the given number of fanins
// - they have no more than the given diff in delay
k = 0;
Vec_PtrForEachEntry( Abc_Obj_t *, vCands, pObj, i )
{
if ( Abc_NodeIsTravIdCurrent(pObj) )
continue;
if ( Abc_ObjFaninNum(pLut) + Abc_ObjFaninNum(pObj) > pPars->nMaxSuppSize )
continue;
if ( Abc_ObjLevel(pLut) - Abc_ObjLevel(pObj) > pPars->nMaxLevelDiff ||
Abc_ObjLevel(pObj) - Abc_ObjLevel(pLut) > pPars->nMaxLevelDiff )
continue;
Vec_PtrWriteEntry( vCands, k++, pObj );
}
Vec_PtrShrink( vCands, k );
}
/**Function*************************************************************
Synopsis [Count the total number of fanins.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkCountTotalFanins( Abc_Obj_t * pLut, Abc_Obj_t * pCand )
{
Abc_Obj_t * pFanin;
int i, nCounter = Abc_ObjFaninNum(pLut);
Abc_ObjForEachFanin( pCand, pFanin, i )
nCounter += !pFanin->fMarkC;
return nCounter;
}
/**Function*************************************************************
Synopsis [Collects overlapping candidates.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkCollectOverlapCands( Abc_Obj_t * pLut, Vec_Ptr_t * vCands, Nwk_LMPars_t * pPars )
{
Abc_Obj_t * pFanin, * pObj;
int i, k;
// mark fanins of pLut
Abc_ObjForEachFanin( pLut, pFanin, i )
pFanin->fMarkC = 1;
// collect the matching fanouts of each fanin of the node
Vec_PtrClear( vCands );
Abc_NtkIncrementTravId( pLut->pNtk );
Abc_NodeSetTravIdCurrent( pLut );
Abc_ObjForEachFanin( pLut, pFanin, i )
{
if ( !Abc_ObjIsNode(pFanin) )
continue;
if ( Abc_ObjFanoutNum(pFanin) > pPars->nMaxFanout )
continue;
Abc_ObjForEachFanout( pFanin, pObj, k )
{
if ( !Abc_ObjIsNode(pObj) )
continue;
if ( Abc_NodeIsTravIdCurrent( pObj ) )
continue;
Abc_NodeSetTravIdCurrent( pObj );
// check the difference in delay
if ( Abc_ObjLevel(pLut) - Abc_ObjLevel(pObj) > pPars->nMaxLevelDiff ||
Abc_ObjLevel(pObj) - Abc_ObjLevel(pLut) > pPars->nMaxLevelDiff )
continue;
// check the total number of fanins of the node
if ( Abc_NtkCountTotalFanins(pLut, pObj) > pPars->nMaxSuppSize )
continue;
Vec_PtrPush( vCands, pObj );
}
}
// unmark fanins of pLut
Abc_ObjForEachFanin( pLut, pFanin, i )
pFanin->fMarkC = 0;
}
/**Function*************************************************************
Synopsis [Performs LUT merging with parameters.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Int_t * Abc_NtkLutMerge( Abc_Ntk_t * pNtk, Nwk_LMPars_t * pPars )
{
Nwk_Grf_t * p;
Vec_Int_t * vResult;
Vec_Ptr_t * vStart, * vNext, * vCands1, * vCands2;
Abc_Obj_t * pLut, * pCand;
int i, k, nVertsMax, nCands;
abctime clk = Abc_Clock();
// count the number of vertices
nVertsMax = 0;
Abc_NtkForEachNode( pNtk, pLut, i )
nVertsMax += (int)(Abc_ObjFaninNum(pLut) <= pPars->nMaxLutSize);
p = Nwk_ManGraphAlloc( nVertsMax );
// create graph
vStart = Vec_PtrAlloc( 1000 );
vNext = Vec_PtrAlloc( 1000 );
vCands1 = Vec_PtrAlloc( 1000 );
vCands2 = Vec_PtrAlloc( 1000 );
nCands = 0;
Abc_NtkForEachNode( pNtk, pLut, i )
{
if ( Abc_ObjFaninNum(pLut) > pPars->nMaxLutSize )
continue;
Abc_NtkCollectOverlapCands( pLut, vCands1, pPars );
if ( pPars->fUseDiffSupp )
Abc_NtkCollectNonOverlapCands( pLut, vStart, vNext, vCands2, pPars );
if ( Vec_PtrSize(vCands1) == 0 && Vec_PtrSize(vCands2) == 0 )
continue;
nCands += Vec_PtrSize(vCands1) + Vec_PtrSize(vCands2);
// save candidates
Vec_PtrForEachEntry( Abc_Obj_t *, vCands1, pCand, k )
Nwk_ManGraphHashEdge( p, Abc_ObjId(pLut), Abc_ObjId(pCand) );
Vec_PtrForEachEntry( Abc_Obj_t *, vCands2, pCand, k )
Nwk_ManGraphHashEdge( p, Abc_ObjId(pLut), Abc_ObjId(pCand) );
// print statistics about this node
if ( pPars->fVeryVerbose )
printf( "Node %6d : Fanins = %d. Fanouts = %3d. Cand1 = %3d. Cand2 = %3d.\n",
Abc_ObjId(pLut), Abc_ObjFaninNum(pLut), Abc_ObjFaninNum(pLut),
Vec_PtrSize(vCands1), Vec_PtrSize(vCands2) );
}
Vec_PtrFree( vStart );
Vec_PtrFree( vNext );
Vec_PtrFree( vCands1 );
Vec_PtrFree( vCands2 );
if ( pPars->fVerbose )
{
printf( "Mergable LUTs = %6d. Total cands = %6d. ", p->nVertsMax, nCands );
ABC_PRT( "Deriving graph", Abc_Clock() - clk );
}
// solve the graph problem
clk = Abc_Clock();
Nwk_ManGraphSolve( p );
if ( pPars->fVerbose )
{
printf( "GRAPH: Nodes = %6d. Edges = %6d. Pairs = %6d. ",
p->nVerts, p->nEdges, Vec_IntSize(p->vPairs)/2 );
ABC_PRT( "Solving", Abc_Clock() - clk );
Nwk_ManGraphReportMemoryUsage( p );
}
vResult = p->vPairs; p->vPairs = NULL;
/*
for ( i = 0; i < vResult->nSize; i += 2 )
printf( "(%d,%d) ", vResult->pArray[i], vResult->pArray[i+1] );
printf( "\n" );
*/
Nwk_ManGraphFree( p );
return vResult;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
