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/**CFile****************************************************************
FileName [ifUtil.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Various utilities.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifUtil.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Sets all the node copy to NULL.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManCleanNodeCopy( If_Man_t * p )
{
If_Obj_t * pObj;
int i;
If_ManForEachObj( p, pObj, i )
If_ObjSetCopy( pObj, NULL );
}
/**Function*************************************************************
Synopsis [Sets all the cut data to NULL.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManCleanCutData( If_Man_t * p )
{
If_Obj_t * pObj;
int i;
If_ManForEachObj( p, pObj, i )
If_CutSetData( If_ObjCutBest(pObj), NULL );
}
/**Function*************************************************************
Synopsis [Sets all visited marks to 0.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManCleanMarkV( If_Man_t * p )
{
If_Obj_t * pObj;
int i;
If_ManForEachObj( p, pObj, i )
pObj->fVisit = 0;
}
/**Function*************************************************************
Synopsis [Returns the max delay of the POs.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_ManDelayMax( If_Man_t * p, int fSeq )
{
If_Obj_t * pObj;
float DelayBest;
int i;
if ( p->pPars->fLatchPaths && p->pPars->nLatches == 0 )
{
printf( "Delay optimization of latch path is not performed because there is no latches.\n" );
p->pPars->fLatchPaths = 0;
}
DelayBest = -IF_FLOAT_LARGE;
if ( fSeq )
{
assert( p->pPars->nLatches > 0 );
If_ManForEachPo( p, pObj, i )
if ( DelayBest < If_ObjArrTime(If_ObjFanin0(pObj)) )
DelayBest = If_ObjArrTime(If_ObjFanin0(pObj));
}
else if ( p->pPars->fLatchPaths )
{
If_ManForEachLatchInput( p, pObj, i )
if ( DelayBest < If_ObjArrTime(If_ObjFanin0(pObj)) )
DelayBest = If_ObjArrTime(If_ObjFanin0(pObj));
}
else
{
If_ManForEachCo( p, pObj, i )
if ( DelayBest < If_ObjArrTime(If_ObjFanin0(pObj)) )
DelayBest = If_ObjArrTime(If_ObjFanin0(pObj));
}
return DelayBest;
}
/**Function*************************************************************
Synopsis [Computes the required times of all nodes.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManComputeRequired( If_Man_t * p )
{
If_Obj_t * pObj;
int i;
// compute area, clean required times, collect nodes used in the mapping
p->nNets = 0;
p->AreaGlo = If_ManScanMapping( p );
// consider the case when the required times are given
if ( p->pPars->pTimesReq )
{
assert( !p->pPars->fAreaOnly );
// make sure that the required time hold
If_ManForEachCo( p, pObj, i )
{
if ( If_ObjArrTime(If_ObjFanin0(pObj)) > p->pPars->pTimesReq[i] + p->fEpsilon )
printf( "Required times are violated for output %d (arr = %d; req = %d).\n",
i, (int)If_ObjArrTime(If_ObjFanin0(pObj)), (int)p->pPars->pTimesReq[i] );
If_ObjFanin0(pObj)->Required = p->pPars->pTimesReq[i];
}
}
else
{
// get the global required times
p->RequiredGlo = If_ManDelayMax( p, 0 );
// update the required times according to the target
if ( p->pPars->DelayTarget != -1 )
{
if ( p->RequiredGlo > p->pPars->DelayTarget + p->fEpsilon )
{
if ( p->fNextRound == 0 )
{
p->fNextRound = 1;
printf( "Cannot meet the target required times (%4.2f). Mapping continues anyway.\n", p->pPars->DelayTarget );
}
}
else if ( p->RequiredGlo < p->pPars->DelayTarget - p->fEpsilon )
{
if ( p->fNextRound == 0 )
{
p->fNextRound = 1;
printf( "Relaxing the required times from (%4.2f) to the target (%4.2f).\n", p->RequiredGlo, p->pPars->DelayTarget );
}
p->RequiredGlo = p->pPars->DelayTarget;
}
}
// do not propagate required times if area minimization is requested
if ( p->pPars->fAreaOnly )
return;
// set the required times for the POs
if ( p->pPars->fLatchPaths )
{
If_ManForEachLatchInput( p, pObj, i )
If_ObjFanin0(pObj)->Required = p->RequiredGlo;
}
else
{
If_ManForEachCo( p, pObj, i )
If_ObjFanin0(pObj)->Required = p->RequiredGlo;
}
}
// go through the nodes in the reverse topological order
Vec_PtrForEachEntry( p->vMapped, pObj, i )
If_CutPropagateRequired( p, If_ObjCutBest(pObj), pObj->Required );
}
/**Function*************************************************************
Synopsis [Computes area, references, and nodes used in the mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_ManScanMapping_rec( If_Man_t * p, If_Obj_t * pObj, If_Obj_t ** ppStore )
{
If_Obj_t * pLeaf;
If_Cut_t * pCutBest;
float aArea;
int i;
if ( pObj->nRefs++ || If_ObjIsCi(pObj) || If_ObjIsConst1(pObj) )
return 0.0;
// store the node in the structure by level
assert( If_ObjIsAnd(pObj) );
pObj->pCopy = (char *)ppStore[pObj->Level];
ppStore[pObj->Level] = pObj;
// visit the transitive fanin of the selected cut
pCutBest = If_ObjCutBest(pObj);
p->nNets += pCutBest->nLeaves;
aArea = If_CutLutArea( p, pCutBest );
If_CutForEachLeaf( p, pCutBest, pLeaf, i )
aArea += If_ManScanMapping_rec( p, pLeaf, ppStore );
return aArea;
}
/**Function*************************************************************
Synopsis [Computes area, references, and nodes used in the mapping.]
Description [Collects the nodes in reverse topological order in array
p->vMapping.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_ManScanMapping( If_Man_t * p )
{
If_Obj_t * pObj, ** ppStore;
float aArea;
int i;
assert( !p->pPars->fLiftLeaves );
// clean all references
If_ManForEachObj( p, pObj, i )
{
pObj->Required = IF_FLOAT_LARGE;
pObj->nVisits = pObj->nVisitsCopy;
pObj->nRefs = 0;
}
// allocate place to store the nodes
ppStore = ALLOC( If_Obj_t *, p->nLevelMax + 1 );
memset( ppStore, 0, sizeof(If_Obj_t *) * (p->nLevelMax + 1) );
// collect nodes reachable from POs in the DFS order through the best cuts
aArea = 0;
If_ManForEachCo( p, pObj, i )
aArea += If_ManScanMapping_rec( p, If_ObjFanin0(pObj), ppStore );
// reconnect the nodes in reverse topological order
Vec_PtrClear( p->vMapped );
for ( i = p->nLevelMax; i >= 0; i-- )
for ( pObj = ppStore[i]; pObj; pObj = pObj->pCopy )
Vec_PtrPush( p->vMapped, pObj );
free( ppStore );
return aArea;
}
/**Function*************************************************************
Synopsis [Computes area, references, and nodes used in the mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_ManScanMappingSeq_rec( If_Man_t * p, If_Obj_t * pObj, Vec_Ptr_t * vMapped )
{
If_Obj_t * pLeaf;
If_Cut_t * pCutBest;
float aArea;
int i, Shift;
// treat latches transparently
if ( If_ObjIsLatch(pObj) )
return If_ManScanMappingSeq_rec( p, If_ObjFanin0(pObj), vMapped );
// consider trivial cases
if ( pObj->nRefs++ || If_ObjIsPi(pObj) || If_ObjIsConst1(pObj) )
return 0.0;
// store the node in the structure by level
assert( If_ObjIsAnd(pObj) );
// visit the transitive fanin of the selected cut
pCutBest = If_ObjCutBest(pObj);
aArea = If_ObjIsAnd(pObj)? If_CutLutArea(p, pCutBest) : (float)0.0;
If_CutForEachLeafSeq( p, pCutBest, pLeaf, Shift, i )
aArea += If_ManScanMappingSeq_rec( p, pLeaf, vMapped );
// add the node
Vec_PtrPush( vMapped, pObj );
return aArea;
}
/**Function*************************************************************
Synopsis [Computes area, references, and nodes used in the mapping.]
Description [Collects the nodes in reverse topological order in array
p->vMapping.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_ManScanMappingSeq( If_Man_t * p )
{
If_Obj_t * pObj;
float aArea;
int i;
assert( p->pPars->fLiftLeaves );
// clean all references
If_ManForEachObj( p, pObj, i )
pObj->nRefs = 0;
// collect nodes reachable from POs in the DFS order through the best cuts
aArea = 0;
Vec_PtrClear( p->vMapped );
If_ManForEachPo( p, pObj, i )
aArea += If_ManScanMappingSeq_rec( p, If_ObjFanin0(pObj), p->vMapped );
return aArea;
}
/**Function*************************************************************
Synopsis [Computes area, references, and nodes used in the mapping.]
Description [Collects the nodes in reverse topological order in array
p->vMapping.]
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManResetOriginalRefs( If_Man_t * p )
{
If_Obj_t * pObj;
int i;
If_ManForEachObj( p, pObj, i )
pObj->nRefs = 0;
If_ManForEachObj( p, pObj, i )
{
if ( If_ObjIsAnd(pObj) )
{
pObj->pFanin0->nRefs++;
pObj->pFanin1->nRefs++;
}
else if ( If_ObjIsCo(pObj) )
pObj->pFanin0->nRefs++;
}
}
/**Function*************************************************************
Synopsis [Computes cross-cut of the circuit.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_ManCrossCut( If_Man_t * p )
{
If_Obj_t * pObj, * pFanin;
int i, nCutSize = 0, nCutSizeMax = 0;
If_ManForEachObj( p, pObj, i )
{
if ( !If_ObjIsAnd(pObj) )
continue;
// consider the node
if ( nCutSizeMax < ++nCutSize )
nCutSizeMax = nCutSize;
if ( pObj->nVisits == 0 )
nCutSize--;
// consider the fanins
pFanin = If_ObjFanin0(pObj);
if ( !If_ObjIsCi(pFanin) && --pFanin->nVisits == 0 )
nCutSize--;
pFanin = If_ObjFanin1(pObj);
if ( !If_ObjIsCi(pFanin) && --pFanin->nVisits == 0 )
nCutSize--;
// consider the choice class
if ( pObj->fRepr )
for ( pFanin = pObj; pFanin; pFanin = pFanin->pEquiv )
if ( !If_ObjIsCi(pFanin) && --pFanin->nVisits == 0 )
nCutSize--;
}
If_ManForEachObj( p, pObj, i )
{
assert( If_ObjIsCi(pObj) || pObj->fVisit == 0 );
pObj->nVisits = pObj->nVisitsCopy;
}
assert( nCutSize == 0 );
// printf( "Max cross cut size = %6d.\n", nCutSizeMax );
return nCutSizeMax;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
