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/**CFile****************************************************************
FileName [abcIfif.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Network and node package.]
Synopsis [Experiment with technology mapping.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: abcIfif.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "src/base/abc/abc.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
typedef struct Abc_IffObj_t_ Abc_IffObj_t;
struct Abc_IffObj_t_
{
int Delay0; // separate delay
int Delay1; // combined delay
int nLeaves;
int pLeaves[6];
};
typedef struct Abc_IffMan_t_ Abc_IffMan_t;
struct Abc_IffMan_t_
{
Abc_Ntk_t * pNtk;
int nObjs;
int nDelayLut;
int nDegree;
int fVerbose;
// internal data
Abc_IffObj_t * pObjs;
};
static inline Abc_IffObj_t * Abc_IffObj( Abc_IffMan_t * p, int i ) { assert( i >= 0 && i < p->nObjs ); return p->pObjs + i; }
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_IffMan_t * Abc_NtkIfifStart( Abc_Ntk_t * pNtk, int nDelayLut, int nDegree, int fVerbose )
{
Abc_IffMan_t * p;
p = ABC_CALLOC( Abc_IffMan_t, 1 );
p->pNtk = pNtk;
p->nObjs = Abc_NtkObjNumMax( pNtk );
p->nDelayLut = nDelayLut;
p->nDegree = nDegree;
p->fVerbose = fVerbose;
// internal data
p->pObjs = ABC_CALLOC( Abc_IffObj_t, p->nObjs );
return p;
}
void Abc_NtkIfifStop( Abc_IffMan_t * p )
{
// internal data
ABC_FREE( p->pObjs );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis [Compare nodes by Delay1 stored in pObj->iTemp.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_ObjIfifCompare( Abc_Obj_t ** pp1, Abc_Obj_t ** pp2 )
{
Abc_Obj_t * pObj1 = *pp1;
Abc_Obj_t * pObj2 = *pp2;
assert( Abc_ObjIsNode(pObj1) && Abc_ObjIsNode(pObj2) );
return (int)pObj2->iTemp - (int)pObj1->iTemp;
}
/**Function*************************************************************
Synopsis [This is the delay which object may have all by itself.]
Description [This delay is stored in Delay0.]
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_ObjDelay0( Abc_IffMan_t * p, Abc_Obj_t * pObj )
{
Abc_Obj_t * pFanin;
int i, Delay0 = 0;
Abc_ObjForEachFanin( pObj, pFanin, i )
Delay0 = Abc_MaxInt( Delay0, Abc_IffObj(p, Abc_ObjId(pFanin))->Delay1 );
return p->nDelayLut + Delay0;
}
/**Function*************************************************************
Synopsis [This is the delay object may have in a group.]
Description [This delay is stored in Delay1 and pObj->iTemp.]
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_ObjDelay1( Abc_IffMan_t * p, Abc_Obj_t * pObj )
{
Abc_IffObj_t * pIfif;
Abc_Obj_t * pNodes[6], * pFanin;
int i, nNodes, Delay1, DelayWorst;
// find the object structure
pIfif = Abc_IffObj( p, Abc_ObjId(pObj) );
// collect relevant nodes
nNodes = 0;
Abc_ObjForEachFanin( pObj, pFanin, i )
if ( Abc_ObjIsNode(pFanin) )
{
assert( pFanin->iTemp >= p->nDelayLut );
pNodes[nNodes++] = pFanin;
}
// process the result
Delay1 = 0;
pIfif->nLeaves = 0;
if ( nNodes > 0 )
{
int fVerbose = 0;
// sort fanins by delay
qsort( (void *)pNodes, nNodes, sizeof(Abc_Obj_t *), (int (*)(const void *, const void *)) Abc_ObjIfifCompare );
assert( pNodes[0]->iTemp >= pNodes[nNodes-1]->iTemp );
if ( fVerbose )
{
for ( i = 0; i < nNodes; i++ )
{
printf( "Fanin %d : ", i );
printf( "D0 %4d ", Abc_IffObj(p, Abc_ObjId(pNodes[i]))->Delay0 );
printf( "D0* %4d ", Abc_IffObj(p, Abc_ObjId(pNodes[0]))->Delay0 - (p->nDelayLut-1) );
printf( "D1 %4d ", Abc_IffObj(p, Abc_ObjId(pNodes[i]))->Delay1 );
printf( "\n" );
}
printf( "\n" );
}
// get the worst-case fanin delay
// DelayWorst = Abc_IffObj(p, Abc_ObjId(pNodes[0]))->Delay0 - (p->nDelayLut-1);
DelayWorst = -1;
// find the delay and remember fanins
for ( i = 0; i < nNodes; i++ )
{
if ( pIfif->nLeaves < p->nDegree && Abc_IffObj(p, Abc_ObjId(pNodes[i]))->Delay1 > DelayWorst )
{
Delay1 = Abc_MaxInt( Delay1, Abc_IffObj(p, Abc_ObjId(pNodes[i]))->Delay0 - (p->nDelayLut-1) );
pIfif->pLeaves[pIfif->nLeaves++] = Abc_ObjId(pNodes[i]);
}
else
Delay1 = Abc_MaxInt( Delay1, Abc_IffObj(p, Abc_ObjId(pNodes[i]))->Delay1 );
}
// assert( pIfif->nLeaves > 0 );
assert( Delay1 > 0 );
}
return p->nDelayLut + Delay1;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkPerformIfif( Abc_Ntk_t * pNtk, int nDelayLut, int nDegree, int fVerbose )
{
Abc_IffMan_t * p;
Abc_IffObj_t * pIffObj;
Vec_Ptr_t * vNodes;
Abc_Obj_t * pObj;
int i, Delay, nLutSize = Abc_NtkGetFaninMax( pNtk );
if ( nLutSize > 6 )
{
printf( "LUT size (%d) is more than 6.\n", nLutSize );
return;
}
// convert to AIGs
Abc_NtkToAig( pNtk );
assert( nDegree >= 0 && nDegree <= 6 );
// start manager
p = Abc_NtkIfifStart( pNtk, nDelayLut, nDegree, fVerbose );
// printf( "Running experiment with LUT delay %d and degree %d (LUT size is %d).\n", nDelayLut, nDegree, nLutSize );
// compute the delay
vNodes = Abc_NtkDfs( pNtk, 0 );
Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
{
assert( Abc_ObjIsNode(pObj) );
pIffObj = Abc_IffObj( p, Abc_ObjId(pObj) );
pIffObj->Delay0 = Abc_ObjDelay0( p, pObj );
pIffObj->Delay1 = Abc_ObjDelay1( p, pObj );
pObj->iTemp = pIffObj->Delay1;
// printf( "Node %3d : Lev =%3d Delay0 =%4d Delay1 =%4d Leaves =%3d.\n",
// Abc_ObjId(pObj), Abc_ObjLevel(pObj), pIffObj->Delay0, pIffObj->Delay1, pIffObj->nLeaves );
}
Vec_PtrFree( vNodes );
// consider delay at the outputs
Delay = 0;
Abc_NtkForEachCo( pNtk, pObj, i )
Delay = Abc_MaxInt( Delay, Abc_IffObj(p, Abc_ObjId(Abc_ObjFanin0(pObj)))->Delay1 );
printf( "Critical delay is %5d (%7.2f).\n", Delay, 1.0 * Delay / nDelayLut );
// derive a new network
// stop manager
Abc_NtkIfifStop( p );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
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