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/**CFile****************************************************************
FileName [ifTime.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Computation of delay paramters depending on the library.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifTime.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static void If_CutSortInputPins( If_Man_t * p, If_Cut_t * pCut, int * pPinPerm, float * pPinDelays );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Computes delay.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float If_CutDelay( If_Man_t * p, If_Cut_t * pCut )
{
static int pPinPerm[IF_MAX_LUTSIZE];
static float pPinDelays[IF_MAX_LUTSIZE];
If_Obj_t * pLeaf;
float Delay, DelayCur;
float * pLutDelays;
int i, Shift;
assert( p->pPars->fSeqMap || pCut->nLeaves > 1 );
Delay = -IF_FLOAT_LARGE;
if ( p->pPars->pLutLib )
{
assert( !p->pPars->fLiftLeaves );
pLutDelays = p->pPars->pLutLib->pLutDelays[pCut->nLeaves];
if ( p->pPars->pLutLib->fVarPinDelays )
{
// compute the delay using sorted pins
If_CutSortInputPins( p, pCut, pPinPerm, pPinDelays );
for ( i = 0; i < (int)pCut->nLeaves; i++ )
{
DelayCur = pPinDelays[pPinPerm[i]] + pLutDelays[i];
Delay = IF_MAX( Delay, DelayCur );
}
}
else
{
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
DelayCur = If_ObjCutBest(pLeaf)->Delay + pLutDelays[0];
Delay = IF_MAX( Delay, DelayCur );
}
}
}
else
{
if ( pCut->fUser )
{
assert( !p->pPars->fLiftLeaves );
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
DelayCur = If_ObjCutBest(pLeaf)->Delay + (float)pCut->pPerm[i];
Delay = IF_MAX( Delay, DelayCur );
}
}
else
{
if ( p->pPars->fLiftLeaves )
{
If_CutForEachLeafSeq( p, pCut, pLeaf, Shift, i )
{
DelayCur = If_ObjCutBest(pLeaf)->Delay - Shift * p->Period;
Delay = IF_MAX( Delay, DelayCur );
}
}
else
{
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
DelayCur = If_ObjCutBest(pLeaf)->Delay;
Delay = IF_MAX( Delay, DelayCur );
}
}
Delay += 1.0;
}
}
return Delay;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_CutPropagateRequired( If_Man_t * p, If_Cut_t * pCut, float ObjRequired )
{
static int pPinPerm[IF_MAX_LUTSIZE];
static float pPinDelays[IF_MAX_LUTSIZE];
If_Obj_t * pLeaf;
float * pLutDelays;
float Required;
int i;
assert( !p->pPars->fLiftLeaves );
// compute the pins
if ( p->pPars->pLutLib )
{
pLutDelays = p->pPars->pLutLib->pLutDelays[pCut->nLeaves];
if ( p->pPars->pLutLib->fVarPinDelays )
{
// compute the delay using sorted pins
If_CutSortInputPins( p, pCut, pPinPerm, pPinDelays );
for ( i = 0; i < (int)pCut->nLeaves; i++ )
{
Required = ObjRequired - pLutDelays[i];
pLeaf = If_ManObj( p, pCut->pLeaves[pPinPerm[i]] );
pLeaf->Required = IF_MIN( pLeaf->Required, Required );
}
}
else
{
Required = ObjRequired - pLutDelays[0];
If_CutForEachLeaf( p, pCut, pLeaf, i )
pLeaf->Required = IF_MIN( pLeaf->Required, Required );
}
}
else
{
if ( pCut->fUser )
{
If_CutForEachLeaf( p, pCut, pLeaf, i )
{
Required = ObjRequired - (float)pCut->pPerm[i];
pLeaf->Required = IF_MIN( pLeaf->Required, Required );
}
}
else
{
Required = ObjRequired - (float)1.0;
If_CutForEachLeaf( p, pCut, pLeaf, i )
pLeaf->Required = IF_MIN( pLeaf->Required, Required );
}
}
}
/**Function*************************************************************
Synopsis [Sorts the pins in the degreasing order of delays.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_CutSortInputPins( If_Man_t * p, If_Cut_t * pCut, int * pPinPerm, float * pPinDelays )
{
If_Obj_t * pLeaf;
int i, j, best_i, temp;
// start the trivial permutation and collect pin delays
If_CutForEachLeaf( p, pCut, pLeaf, i );
{
pPinPerm[i] = i;
pPinDelays[i] = If_ObjCutBest(pLeaf)->Delay;
}
// selection sort the pins in the decreasible order of delays
// this order will match the increasing order of LUT input pins
for ( i = 0; i < (int)pCut->nLeaves-1; i++ )
{
best_i = i;
for ( j = i+1; j < (int)pCut->nLeaves; j++ )
if ( pPinDelays[pPinPerm[j]] > pPinDelays[pPinPerm[best_i]] )
best_i = j;
if ( best_i == i )
continue;
temp = pPinPerm[i];
pPinPerm[i] = pPinPerm[best_i];
pPinPerm[best_i] = temp;
}
// verify
for ( i = 1; i < (int)pCut->nLeaves; i++ )
assert( pPinDelays[pPinPerm[i-1]] >= pPinDelays[pPinPerm[i]] );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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