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/**CFile****************************************************************
FileName [sfmWin.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [SAT-based optimization using internal don't-cares.]
Synopsis [Structural window computation.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: sfmWin.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "sfmInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Returns the MFFC size.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Sfm_ObjRef_rec( Sfm_Ntk_t * p, int iObj )
{
int i, iFanin, Value, Count;
if ( Sfm_ObjIsPi(p, iObj) )
return 0;
assert( Sfm_ObjIsNode(p, iObj) );
Value = Sfm_ObjRefIncrement(p, iObj);
if ( Value > 1 )
return 0;
assert( Value == 1 );
Count = 1;
Sfm_ObjForEachFanin( p, iObj, iFanin, i )
Count += Sfm_ObjRef_rec( p, iFanin );
return Count;
}
int Sfm_ObjRef( Sfm_Ntk_t * p, int iObj )
{
int i, iFanin, Count = 1;
Sfm_ObjForEachFanin( p, iObj, iFanin, i )
Count += Sfm_ObjRef_rec( p, iFanin );
return Count;
}
int Sfm_ObjDeref_rec( Sfm_Ntk_t * p, int iObj )
{
int i, iFanin, Value, Count;
if ( Sfm_ObjIsPi(p, iObj) )
return 0;
assert( Sfm_ObjIsNode(p, iObj) );
Value = Sfm_ObjRefDecrement(p, iObj);
if ( Value > 0 )
return 0;
assert( Value == 0 );
Count = 1;
Sfm_ObjForEachFanin( p, iObj, iFanin, i )
Count += Sfm_ObjDeref_rec( p, iFanin );
return Count;
}
int Sfm_ObjDeref( Sfm_Ntk_t * p, int iObj )
{
int i, iFanin, Count = 1;
Sfm_ObjForEachFanin( p, iObj, iFanin, i )
Count += Sfm_ObjDeref_rec( p, iFanin );
return Count;
}
int Sfm_ObjMffcSize( Sfm_Ntk_t * p, int iObj )
{
int Count1, Count2;
if ( Sfm_ObjIsPi(p, iObj) )
return 0;
if ( Sfm_ObjFanoutNum(p, iObj) != 1 )
return 0;
assert( Sfm_ObjIsNode( p, iObj ) );
Count1 = Sfm_ObjDeref( p, iObj );
Count2 = Sfm_ObjRef( p, iObj );
assert( Count1 == Count2 );
return Count1;
}
/**Function*************************************************************
Synopsis [Working with traversal IDs.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline void Sfm_NtkIncrementTravId( Sfm_Ntk_t * p ) { p->nTravIds++; }
static inline void Sfm_ObjSetTravIdCurrent( Sfm_Ntk_t * p, int Id ) { Vec_IntWriteEntry( &p->vTravIds, Id, p->nTravIds ); }
static inline int Sfm_ObjIsTravIdCurrent( Sfm_Ntk_t * p, int Id ) { return (Vec_IntEntry(&p->vTravIds, Id) == p->nTravIds); }
static inline void Sfm_NtkIncrementTravId2( Sfm_Ntk_t * p ) { p->nTravIds2++; }
static inline void Sfm_ObjSetTravIdCurrent2( Sfm_Ntk_t * p, int Id ) { Vec_IntWriteEntry( &p->vTravIds2, Id, p->nTravIds2 ); }
static inline int Sfm_ObjIsTravIdCurrent2( Sfm_Ntk_t * p, int Id ) { return (Vec_IntEntry(&p->vTravIds2, Id) == p->nTravIds2); }
/**Function*************************************************************
Synopsis [Check if this fanout overlaps with TFI cone of the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Sfm_NtkCheckOverlap_rec( Sfm_Ntk_t * p, int iThis, int iNode )
{
int i, iFanin;
if ( Sfm_ObjIsTravIdCurrent2(p, iThis) || iThis == iNode )
return 0;
if ( Sfm_ObjIsTravIdCurrent(p, iThis) )
return 1;
Sfm_ObjSetTravIdCurrent2(p, iThis);
Sfm_ObjForEachFanin( p, iThis, iFanin, i )
if ( Sfm_NtkCheckOverlap_rec(p, iFanin, iNode) )
return 1;
return 0;
}
int Sfm_NtkCheckOverlap( Sfm_Ntk_t * p, int iFan, int iNode )
{
Sfm_NtkIncrementTravId2( p );
return Sfm_NtkCheckOverlap_rec( p, iFan, iNode );
}
/**Function*************************************************************
Synopsis [Check fanouts of the node.]
Description [Returns 1 if they can be used instead of the node.]
SideEffects []
SeeAlso []
***********************************************************************/
int Sfm_NtkCheckFanouts( Sfm_Ntk_t * p, int iNode )
{
int i, iFanout;
if ( Sfm_ObjFanoutNum(p, iNode) >= p->pPars->nFanoutMax )
return 0;
Sfm_ObjForEachFanout( p, iNode, iFanout, i )
if ( !Sfm_NtkCheckOverlap( p, iFanout, iNode ) )
return 0;
return 1;
}
/**Function*************************************************************
Synopsis [Collects divisors of the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Sfm_NtkAddDivisors( Sfm_Ntk_t * p, int iNode, int nLevelMax )
{
int i, iFanout;
Sfm_ObjForEachFanout( p, iNode, iFanout, i )
{
// skip some of the fanouts if the number is large
if ( p->pPars->nFanoutMax && i > p->pPars->nFanoutMax )
return;
// skip TFI nodes, PO nodes, or nodes with high logic level
if ( Sfm_ObjIsTravIdCurrent(p, iFanout) || Sfm_ObjIsPo(p, iFanout) ||
(p->pPars->fFixLevel && Sfm_ObjLevel(p, iFanout) >= nLevelMax) )
continue;
// handle single-input nodes
if ( Sfm_ObjFaninNum(p, iFanout) == 1 )
Vec_IntPush( p->vDivs, iFanout );
// visit node for the first time
else if ( !Sfm_ObjIsTravIdCurrent2(p, iFanout) )
{
assert( Sfm_ObjFaninNum(p, iFanout) > 1 );
Sfm_ObjSetTravIdCurrent2( p, iFanout );
Sfm_ObjResetFaninCount( p, iFanout );
}
// visit node again
else if ( Sfm_ObjUpdateFaninCount(p, iFanout) == 0 )
Vec_IntPush( p->vDivs, iFanout );
}
}
/**Function*************************************************************
Synopsis [Fixed object is useful when it has a non-fixed fanout.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int Sfm_ObjIsUseful( Sfm_Ntk_t * p, int iNode )
{
int i, iFanout;
if ( !Sfm_ObjIsFixed(p, iNode) )
return 1;
Sfm_ObjForEachFanout( p, iNode, iFanout, i )
if ( !Sfm_ObjIsFixed(p, iFanout) )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Computes structural window.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Sfm_NtkCollectTfi_rec( Sfm_Ntk_t * p, int iNode, int nWinSizeMax )
{
int i, iFanin;
if ( Sfm_ObjIsTravIdCurrent( p, iNode ) )
return 0;
Sfm_ObjSetTravIdCurrent( p, iNode );
if ( Sfm_ObjIsPi( p, iNode ) )
{
Vec_IntPush( p->vLeaves, iNode );
return 0;
}
Sfm_ObjForEachFanin( p, iNode, iFanin, i )
if ( Sfm_NtkCollectTfi_rec( p, iFanin, nWinSizeMax ) )
return 1;
Vec_IntPush( p->vNodes, iNode );
return nWinSizeMax && (Vec_IntSize(p->vNodes) > nWinSizeMax);
}
int Sfm_NtkCreateWindow( Sfm_Ntk_t * p, int iNode, int fVerbose )
{
int i, k, iTemp, nDivStart;
clock_t clk = clock();
assert( Sfm_ObjIsNode( p, iNode ) );
Vec_IntClear( p->vLeaves ); // leaves
Vec_IntClear( p->vNodes ); // internal
Vec_IntClear( p->vDivs ); // divisors
Vec_IntClear( p->vRoots ); // roots
Vec_IntClear( p->vTfo ); // roots
// collect transitive fanin
Sfm_NtkIncrementTravId( p );
if ( Sfm_NtkCollectTfi_rec( p, iNode, p->pPars->nWinSizeMax ) )
{
p->nMaxDivs++;
p->timeWin += clock() - clk;
return 0;
}
// collect TFO (currently use only one level of TFO)
// if ( Sfm_NtkCheckFanouts(p, iNode) )
if ( 0 )
{
Sfm_ObjForEachFanout( p, iNode, iTemp, i )
{
if ( Sfm_ObjIsPo(p, iTemp) )
continue;
Vec_IntPush( p->vRoots, iTemp );
Vec_IntPush( p->vTfo, iTemp );
}
}
else
Vec_IntPush( p->vRoots, iNode );
p->timeWin += clock() - clk;
clk = clock();
// create divisors
Vec_IntClear( p->vDivs );
Vec_IntForEachEntry( p->vLeaves, iTemp, i )
Vec_IntPush( p->vDivs, iTemp );
Vec_IntForEachEntry( p->vNodes, iTemp, i )
Vec_IntPush( p->vDivs, iTemp );
Vec_IntPop( p->vDivs );
// add non-topological divisors
nDivStart = Vec_IntSize(p->vDivs);
if ( Vec_IntSize(p->vDivs) < p->pPars->nWinSizeMax )
{
Sfm_NtkIncrementTravId2( p );
Vec_IntForEachEntry( p->vDivs, iTemp, i )
if ( Vec_IntSize(p->vDivs) < p->pPars->nWinSizeMax )
Sfm_NtkAddDivisors( p, iTemp, Sfm_ObjLevel(p, iNode) );
}
if ( Vec_IntSize(p->vDivs) > p->pPars->nWinSizeMax )
Vec_IntShrink( p->vDivs, p->pPars->nWinSizeMax );
assert( Vec_IntSize(p->vDivs) <= p->pPars->nWinSizeMax );
p->nMaxDivs += (Vec_IntSize(p->vDivs) == p->pPars->nWinSizeMax);
// create ordering of the nodes
Vec_IntClear( p->vOrder );
Vec_IntForEachEntryReverse( p->vNodes, iTemp, i )
Vec_IntPush( p->vOrder, iTemp );
Vec_IntForEachEntry( p->vLeaves, iTemp, i )
Vec_IntPush( p->vOrder, iTemp );
Vec_IntForEachEntryStart( p->vDivs, iTemp, i, nDivStart )
Vec_IntPush( p->vOrder, iTemp );
// remove fanins from divisors
// mark fanins
Sfm_NtkIncrementTravId2( p );
Sfm_ObjSetTravIdCurrent2( p, iNode );
Sfm_ObjForEachFanin( p, iNode, iTemp, i )
Sfm_ObjSetTravIdCurrent2( p, iTemp );
// compact divisors
k = 0;
Vec_IntForEachEntry( p->vDivs, iTemp, i )
if ( !Sfm_ObjIsTravIdCurrent2(p, iTemp) && Sfm_ObjIsUseful(p, iTemp) )
Vec_IntWriteEntry( p->vDivs, k++, iTemp );
Vec_IntShrink( p->vDivs, k );
assert( Vec_IntSize(p->vDivs) <= p->pPars->nWinSizeMax );
// statistics
p->nTotalDivs += Vec_IntSize(p->vDivs);
p->timeDiv += clock() - clk;
if ( !fVerbose )
return 1;
// print stats about the window
printf( "%6d : ", iNode );
printf( "Leaves = %5d. ", Vec_IntSize(p->vLeaves) );
printf( "Nodes = %5d. ", Vec_IntSize(p->vNodes) );
printf( "Roots = %5d. ", Vec_IntSize(p->vRoots) );
printf( "Divs = %5d. ", Vec_IntSize(p->vDivs) );
printf( "\n" );
return 1;
}
void Sfm_NtkWindowTest( Sfm_Ntk_t * p, int iNode )
{
int i;
Sfm_NtkForEachNode( p, i )
Sfm_NtkCreateWindow( p, i, 1 );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
