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/**CFile****************************************************************
FileName [ifMap.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Mapping procedures.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifMap.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
/*
Ideas to try:
- reverse order of area recovery
- ordering of the outputs by size
- merging Delay, Delay2, and Area
- expand/reduce area recovery
*/
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Counts the number of 1s in the signature.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_WordCountOnes( unsigned uWord )
{
uWord = (uWord & 0x55555555) + ((uWord>>1) & 0x55555555);
uWord = (uWord & 0x33333333) + ((uWord>>2) & 0x33333333);
uWord = (uWord & 0x0F0F0F0F) + ((uWord>>4) & 0x0F0F0F0F);
uWord = (uWord & 0x00FF00FF) + ((uWord>>8) & 0x00FF00FF);
return (uWord & 0x0000FFFF) + (uWord>>16);
}
/**Function*************************************************************
Synopsis [Returns 1 if pDom is contained in pCut.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_CutCheckDominance( If_Cut_t * pDom, If_Cut_t * pCut )
{
int i, k;
for ( i = 0; i < (int)pDom->nLeaves; i++ )
{
for ( k = 0; k < (int)pCut->nLeaves; k++ )
if ( pDom->pLeaves[i] == pCut->pLeaves[k] )
break;
if ( k == (int)pCut->nLeaves ) // node i in pDom is not contained in pCut
return 0;
}
// every node in pDom is contained in pCut
return 1;
}
/**Function*************************************************************
Synopsis [Returns 1 if pDom is equal to pCut.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_CutCheckEquality( If_Cut_t * pDom, If_Cut_t * pCut )
{
int i;
if ( (int)pDom->nLeaves != (int)pCut->nLeaves )
return 0;
for ( i = 0; i < (int)pDom->nLeaves; i++ )
if ( pDom->pLeaves[i] != pCut->pLeaves[i] )
return 0;
return 1;
}
/**Function*************************************************************
Synopsis [Returns 1 if the cut is contained.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutFilter( If_Man_t * p, If_Cut_t * pCut, int Mode )
{
If_Cut_t * pTemp;
int i;
for ( i = 0; i < p->nCuts; i++ )
{
pTemp = p->ppCuts[i];
if ( pTemp->nLeaves > pCut->nLeaves )
{
// continue;
// skip the non-contained cuts
if ( (pTemp->uSign & pCut->uSign) != pCut->uSign )
continue;
// check containment seriously
if ( If_CutCheckDominance( pCut, pTemp ) )
{
// removed contained cut
p->ppCuts[i] = p->ppCuts[p->nCuts-1];
p->ppCuts[p->nCuts-1] = pTemp;
p->nCuts--;
i--;
}
}
else
{
// skip the non-contained cuts
if ( (pTemp->uSign & pCut->uSign) != pTemp->uSign )
continue;
// check containment seriously
if ( If_CutCheckDominance( pTemp, pCut ) )
return 1;
}
}
return 0;
}
/**Function*************************************************************
Synopsis [Merges two cuts.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_CutMergeOrdered( If_Cut_t * pC0, If_Cut_t * pC1, If_Cut_t * pC, int nLimit )
{
int i, k, c;
assert( pC0->nLeaves >= pC1->nLeaves );
// the case of the largest cut sizes
if ( pC0->nLeaves == nLimit && pC1->nLeaves == nLimit )
{
for ( i = 0; i < pC0->nLeaves; i++ )
if ( pC0->pLeaves[i] != pC1->pLeaves[i] )
return 0;
for ( i = 0; i < pC0->nLeaves; i++ )
pC->pLeaves[i] = pC0->pLeaves[i];
pC->nLeaves = pC0->nLeaves;
return 1;
}
// the case when one of the cuts is the largest
if ( pC0->nLeaves == nLimit )
{
for ( i = 0; i < pC1->nLeaves; i++ )
{
for ( k = pC0->nLeaves - 1; k >= 0; k-- )
if ( pC0->pLeaves[k] == pC1->pLeaves[i] )
break;
if ( k == -1 ) // did not find
return 0;
}
for ( i = 0; i < pC0->nLeaves; i++ )
pC->pLeaves[i] = pC0->pLeaves[i];
pC->nLeaves = pC0->nLeaves;
return 1;
}
// compare two cuts with different numbers
i = k = 0;
for ( c = 0; c < nLimit; c++ )
{
if ( k == pC1->nLeaves )
{
if ( i == pC0->nLeaves )
{
pC->nLeaves = c;
return 1;
}
pC->pLeaves[c] = pC0->pLeaves[i++];
continue;
}
if ( i == pC0->nLeaves )
{
if ( k == pC1->nLeaves )
{
pC->nLeaves = c;
return 1;
}
pC->pLeaves[c] = pC1->pLeaves[k++];
continue;
}
if ( pC0->pLeaves[i] < pC1->pLeaves[k] )
{
pC->pLeaves[c] = pC0->pLeaves[i++];
continue;
}
if ( pC0->pLeaves[i] > pC1->pLeaves[k] )
{
pC->pLeaves[c] = pC1->pLeaves[k++];
continue;
}
pC->pLeaves[c] = pC0->pLeaves[i++];
k++;
}
if ( i < pC0->nLeaves || k < pC1->nLeaves )
return 0;
pC->nLeaves = c;
return 1;
}
/**Function*************************************************************
Synopsis [Merges two cuts.]
Description [Special case when the cut is known to exist.]
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_CutMergeOrdered2( If_Cut_t * pC0, If_Cut_t * pC1, If_Cut_t * pC, int nLimit )
{
int i, k, c;
assert( pC0->nLeaves >= pC1->nLeaves );
// copy the first cut
for ( i = 0; i < pC0->nLeaves; i++ )
pC->pLeaves[i] = pC0->pLeaves[i];
pC->nLeaves = pC0->nLeaves;
// the case when one of the cuts is the largest
if ( pC0->nLeaves == nLimit )
return 1;
// add nodes of the second cut
k = 0;
for ( i = 0; i < pC1->nLeaves; i++ )
{
// find k-th node before which i-th node should be added
for ( ; k < pC->nLeaves; k++ )
if ( pC->pLeaves[k] >= pC1->pLeaves[i] )
break;
// check the case when this should be the last node
if ( k == pC->nLeaves )
{
pC->pLeaves[k++] = pC1->pLeaves[i];
pC->nLeaves++;
continue;
}
// check the case when equal node is found
if ( pC1->pLeaves[i] == pC->pLeaves[k] )
continue;
// add the node
for ( c = pC->nLeaves; c > k; c-- )
pC->pLeaves[c] = pC->pLeaves[c-1];
pC->pLeaves[k++] = pC1->pLeaves[i];
pC->nLeaves++;
}
assert( pC->nLeaves <= nLimit );
for ( i = 1; i < pC->nLeaves; i++ )
assert( pC->pLeaves[i-1] < pC->pLeaves[i] );
return 1;
}
/**Function*************************************************************
Synopsis [Prepares the object for FPGA mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutMerge( If_Cut_t * pCut0, If_Cut_t * pCut1, If_Cut_t * pCut, int nLimit )
{
// merge the nodes
if ( pCut0->nLeaves < pCut1->nLeaves )
{
if ( !If_CutMergeOrdered( pCut1, pCut0, pCut, nLimit ) )
return 0;
}
else
{
if ( !If_CutMergeOrdered( pCut0, pCut1, pCut, nLimit ) )
return 0;
}
return 1;
}
/**Function*************************************************************
Synopsis [Prepares the object for FPGA mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutCompareDelay( If_Cut_t ** ppC0, If_Cut_t ** ppC1 )
{
If_Cut_t * pC0 = *ppC0;
If_Cut_t * pC1 = *ppC1;
if ( pC0->Delay < pC1->Delay - 0.0001 )
return -1;
if ( pC0->Delay > pC1->Delay + 0.0001 )
return 1;
if ( pC0->nLeaves < pC1->nLeaves )
return -1;
if ( pC0->nLeaves > pC1->nLeaves )
return 1;
if ( pC0->Area < pC1->Area - 0.0001 )
return -1;
if ( pC0->Area > pC1->Area + 0.0001 )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Prepares the object for FPGA mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutCompareDelayOld( If_Cut_t ** ppC0, If_Cut_t ** ppC1 )
{
If_Cut_t * pC0 = *ppC0;
If_Cut_t * pC1 = *ppC1;
if ( pC0->Delay < pC1->Delay - 0.0001 )
return -1;
if ( pC0->Delay > pC1->Delay + 0.0001 )
return 1;
if ( pC0->Area < pC1->Area - 0.0001 )
return -1;
if ( pC0->Area > pC1->Area + 0.0001 )
return 1;
if ( pC0->nLeaves < pC1->nLeaves )
return -1;
if ( pC0->nLeaves > pC1->nLeaves )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Prepares the object for FPGA mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutCompareArea( If_Cut_t ** ppC0, If_Cut_t ** ppC1 )
{
If_Cut_t * pC0 = *ppC0;
If_Cut_t * pC1 = *ppC1;
if ( pC0->Area < pC1->Area - 0.0001 )
return -1;
if ( pC0->Area > pC1->Area + 0.0001 )
return 1;
if ( pC0->nLeaves < pC1->nLeaves )
return -1;
if ( pC0->nLeaves > pC1->nLeaves )
return 1;
if ( pC0->Delay < pC1->Delay - 0.0001 )
return -1;
if ( pC0->Delay > pC1->Delay + 0.0001 )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Sorts the cuts.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManSortCuts( If_Man_t * p, int Mode )
{
// sort the cuts
if ( Mode || p->pPars->fArea ) // area
qsort( p->ppCuts, p->nCuts, sizeof(If_Cut_t *), (int (*)(const void *, const void *))If_CutCompareArea );
else if ( p->pPars->fFancy )
qsort( p->ppCuts, p->nCuts, sizeof(If_Cut_t *), (int (*)(const void *, const void *))If_CutCompareDelayOld );
else
qsort( p->ppCuts, p->nCuts, sizeof(If_Cut_t *), (int (*)(const void *, const void *))If_CutCompareDelay );
}
/**Function*************************************************************
Synopsis [Computes delay.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutDelay( If_Man_t * p, If_Cut_t * pCut )
{
If_Obj_t * pLeaf;
float Delay;
int i;
assert( pCut->nLeaves > 1 );
Delay = -IF_FLOAT_LARGE;
If_CutForEachLeaf( p, pCut, pLeaf, i )
Delay = IF_MAX( Delay, If_ObjCutBest(pLeaf)->Delay );
return Delay + If_CutLutDelay(p, pCut);
}
/**Function*************************************************************
Synopsis [Computes area flow.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutFlow( If_Man_t * p, If_Cut_t * pCut )
{
If_Obj_t * pLeaf;
float Flow;
int i;
assert( pCut->nLeaves > 1 );
Flow = If_CutLutArea(p, pCut);
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
if ( pLeaf->nRefs == 0 )
Flow += If_ObjCutBest(pLeaf)->Area;
else
{
assert( pLeaf->EstRefs > p->fEpsilon );
Flow += If_ObjCutBest(pLeaf)->Area / pLeaf->EstRefs;
}
}
return Flow;
}
/**Function*************************************************************
Synopsis [Computes area of the first level.]
Description [The cut need to be derefed.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutDeref( If_Man_t * p, If_Cut_t * pCut, int nLevels )
{
If_Obj_t * pLeaf;
float Area;
int i;
Area = If_CutLutArea(p, pCut);
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
assert( pLeaf->nRefs > 0 );
if ( --pLeaf->nRefs > 0 || !If_ObjIsAnd(pLeaf) || nLevels == 1 )
continue;
Area += If_CutDeref( p, If_ObjCutBest(pLeaf), nLevels - 1 );
}
return Area;
}
/**Function*************************************************************
Synopsis [Computes area of the first level.]
Description [The cut need to be derefed.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutRef( If_Man_t * p, If_Cut_t * pCut, int nLevels )
{
If_Obj_t * pLeaf;
float Area;
int i;
Area = If_CutLutArea(p, pCut);
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
assert( pLeaf->nRefs >= 0 );
if ( pLeaf->nRefs++ > 0 || !If_ObjIsAnd(pLeaf) || nLevels == 1 )
continue;
Area += If_CutRef( p, If_ObjCutBest(pLeaf), nLevels - 1 );
}
return Area;
}
/**Function*************************************************************
Synopsis [Prints one cut.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_CutPrint( If_Man_t * p, If_Cut_t * pCut )
{
int i;
printf( "{" );
for ( i = 0; i < pCut->nLeaves; i++ )
printf( " %d", pCut->pLeaves[i] );
printf( " }\n" );
}
/**Function*************************************************************
Synopsis [Computes area of the first level.]
Description [The cut need to be derefed.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutAreaDerefed( If_Man_t * p, If_Cut_t * pCut, int nLevels )
{
float aResult, aResult2;
assert( pCut->nLeaves > 1 );
aResult2 = If_CutRef( p, pCut, nLevels );
aResult = If_CutDeref( p, pCut, nLevels );
assert( aResult == aResult2 );
return aResult;
}
/**Function*************************************************************
Synopsis [Computes area of the first level.]
Description [The cut need to be derefed.]
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutAreaRefed( If_Man_t * p, If_Cut_t * pCut, int nLevels )
{
float aResult, aResult2;
assert( pCut->nLeaves > 1 );
aResult2 = If_CutDeref( p, pCut, nLevels );
aResult = If_CutRef( p, pCut, nLevels );
assert( aResult == aResult2 );
return aResult;
}
/**Function*************************************************************
Synopsis [Computes area of the first level.]
Description [The cut need to be derefed.]
SideEffects []
SeeAlso []
***********************************************************************/
void If_CutCopy( If_Cut_t * pCutDest, If_Cut_t * pCutSrc )
{
int * pArray;
pArray = pCutDest->pLeaves;
*pCutDest = *pCutSrc;
pCutDest->pLeaves = pArray;
memcpy( pCutDest->pLeaves, pCutSrc->pLeaves, sizeof(int) * pCutSrc->nLeaves );
}
/**Function*************************************************************
Synopsis [Finds the best cut.]
Description [Mapping modes: delay (0), area flow (1), area (2).]
SideEffects []
SeeAlso []
***********************************************************************/
void If_ObjPerformMapping( If_Man_t * p, If_Obj_t * pObj, int Mode )
{
If_Cut_t * pCut0, * pCut1, * pCut;
int i, k, iCut;
// prepare
if ( Mode == 0 )
pObj->EstRefs = (float)pObj->nRefs;
else if ( Mode == 1 )
pObj->EstRefs = (float)((2.0 * pObj->EstRefs + pObj->nRefs) / 3.0);
else if ( Mode == 2 && pObj->nRefs > 0 )
If_CutDeref( p, If_ObjCutBest(pObj), 100 );
// recompute the parameters of the best cut
p->nCuts = 0;
p->nCutsMerged++;
if ( Mode )
{
pCut = If_ObjCutBest(pObj);
pCut->Delay = If_CutDelay( p, pCut );
assert( pCut->Delay <= pObj->Required + p->fEpsilon );
pCut->Area = (Mode == 2)? If_CutAreaDerefed( p, pCut, 100 ) : If_CutFlow( p, pCut );
// save the best cut from the previous iteration
If_CutCopy( p->ppCuts[p->nCuts++], pCut );
p->nCutsMerged++;
}
// prepare room for the next cut
iCut = p->nCuts;
pCut = p->ppCuts[iCut];
// generate cuts
If_ObjForEachCut( pObj->pFanin0, pCut0, i )
If_ObjForEachCut( pObj->pFanin1, pCut1, k )
{
// make sure K-feasible cut exists
if ( If_WordCountOnes(pCut0->uSign | pCut1->uSign) > p->pPars->nLutSize )
continue;
// prefilter using arrival times
if ( Mode && (pCut0->Delay > pObj->Required + p->fEpsilon || pCut1->Delay > pObj->Required + p->fEpsilon) )
continue;
// merge the nodes
if ( !If_CutMerge( pCut0, pCut1, pCut, p->pPars->nLutSize ) )
continue;
// check if this cut is contained in any of the available cuts
pCut->uSign = pCut0->uSign | pCut1->uSign;
if ( If_CutFilter( p, pCut, Mode ) )
continue;
// check if the cut satisfies the required times
pCut->Delay = If_CutDelay( p, pCut );
if ( Mode && pCut->Delay > pObj->Required + p->fEpsilon )
continue;
// the cuts have been successfully merged
pCut->pOne = pCut0; pCut->fCompl0 = pObj->fCompl0;
pCut->pTwo = pCut1; pCut->fCompl1 = pObj->fCompl1;
// pCut->Phase = ...
// pCut->Phase = (char)(int)If_CutAreaDerefed( p, pCut, 1 );
pCut->Area = (Mode == 2)? If_CutAreaDerefed( p, pCut, 100 ) : If_CutFlow( p, pCut );
p->nCutsMerged++;
// make sure the cut is the last one (after filtering it may not be so)
assert( pCut == p->ppCuts[iCut] );
p->ppCuts[iCut] = p->ppCuts[p->nCuts];
p->ppCuts[p->nCuts] = pCut;
// prepare room for the next cut
iCut = ++p->nCuts;
pCut = p->ppCuts[iCut];
}
//printf( "%d ", p->nCuts );
assert( p->nCuts > 0 );
// sort if we have more cuts
If_ManSortCuts( p, Mode );
// decide how many cuts to use
pObj->nCuts = IF_MIN( p->nCuts + 1, p->nCutsUsed );
// take the first
If_ObjForEachCutStart( pObj, pCut, i, 1 )
If_CutCopy( pCut, p->ppCuts[i-1] );
assert( If_ObjCutBest(pObj)->nLeaves > 1 );
// assign delay of the trivial cut
If_ObjCutTriv(pObj)->Delay = If_ObjCutBest(pObj)->Delay;
//printf( "%d %d ", pObj->Id, (int)If_ObjCutBest(pObj)->Delay );
//printf( "%d %d ", pObj->Id, pObj->nCuts );
// ref the selected cut
if ( Mode == 2 && pObj->nRefs > 0 )
If_CutRef( p, If_ObjCutBest(pObj), 100 );
// find the largest cut
if ( p->nCutsMax < pObj->nCuts )
p->nCutsMax = pObj->nCuts;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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