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/**CFile****************************************************************
FileName [ifPrepro.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Selects the starting mapping.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifPrepro.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static void If_ManPerformMappingMoveBestCut( If_Man_t * p, int iPosNew, int iPosOld );
static void If_ManPerformMappingAdjust( If_Man_t * p, int nCuts );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Merges the results of delay, relaxed delay and area-based mapping.]
Description [Delay target may be different from minimum delay!!!]
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManPerformMappingPreprocess( If_Man_t * p )
{
float delayArea, delayDelay, delayPure;
int clk = clock();
assert( p->pPars->nCutsMax >= 4 );
// perform min-area mapping and move the cut to the end
p->pPars->fArea = 1;
If_ManPerformMappingRound( p, p->pPars->nCutsMax, 0, 0 );
p->pPars->fArea = 0;
delayArea = If_ManDelayMax( p );
if ( p->pPars->DelayTarget != -1 && delayArea < p->pPars->DelayTarget - p->fEpsilon )
delayArea = p->pPars->DelayTarget;
If_ManPerformMappingMoveBestCut( p, p->pPars->nCutsMax - 1, 1 );
// perfrom min-delay mapping and move the cut to the end
p->pPars->fFancy = 1;
If_ManPerformMappingRound( p, p->pPars->nCutsMax - 1, 0, 0 );
p->pPars->fFancy = 0;
delayDelay = If_ManDelayMax( p );
if ( p->pPars->DelayTarget != -1 && delayDelay < p->pPars->DelayTarget - p->fEpsilon )
delayDelay = p->pPars->DelayTarget;
If_ManPerformMappingMoveBestCut( p, p->pPars->nCutsMax - 2, 1 );
// perform min-area mapping
If_ManPerformMappingRound( p, p->pPars->nCutsMax - 2, 0, 0 );
delayPure = If_ManDelayMax( p );
if ( p->pPars->DelayTarget != -1 && delayPure < p->pPars->DelayTarget - p->fEpsilon )
delayPure = p->pPars->DelayTarget;
// decide what to do
if ( delayPure < delayDelay - p->fEpsilon && delayPure < delayArea - p->fEpsilon )
{
// copy the remaining two cuts
if ( p->pPars->nCutsMax > 4 )
{
If_ManPerformMappingMoveBestCut( p, 2, p->pPars->nCutsMax - 2 );
If_ManPerformMappingMoveBestCut( p, 3, p->pPars->nCutsMax - 1 );
}
If_ManComputeRequired( p, 1 );
If_ManPerformMappingAdjust( p, 4 );
}
else if ( delayDelay < delayArea - p->fEpsilon )
{
If_ManPerformMappingMoveBestCut( p, 1, p->pPars->nCutsMax - 2 );
If_ManPerformMappingMoveBestCut( p, 2, p->pPars->nCutsMax - 1 );
If_ManComputeRequired( p, 1 );
If_ManPerformMappingAdjust( p, 3 );
}
else
{
If_ManPerformMappingMoveBestCut( p, 1, p->pPars->nCutsMax - 1 );
If_ManComputeRequired( p, 1 );
If_ManPerformMappingAdjust( p, 2 );
}
If_ManComputeRequired( p, 1 );
if ( p->pPars->fVerbose )
{
printf( "S: Del = %6.2f. Area = %8.2f. Cuts = %6d. Lim = %2d. Ave = %5.2f. ",
p->RequiredGlo, p->AreaGlo, p->nCutsMerged, p->nCutsUsed, 1.0 * p->nCutsMerged / If_ManAndNum(p) );
PRT( "T", clock() - clk );
}
}
/**Function*************************************************************
Synopsis [Moves the best cut to the given position.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManPerformMappingMoveBestCut( If_Man_t * p, int iPosNew, int iPosOld )
{
If_Obj_t * pObj;
int i;
assert( iPosOld != iPosNew );
assert( iPosOld > 0 && iPosOld < p->pPars->nCutsMax );
assert( iPosNew > 0 && iPosNew < p->pPars->nCutsMax );
If_ManForEachNode( p, pObj, i )
If_CutCopy( pObj->Cuts + iPosNew, pObj->Cuts + iPosOld );
}
/**Function*************************************************************
Synopsis [Adjusts mapping for the given cuts.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ManPerformMappingAdjust( If_Man_t * p, int nCuts )
{
If_Cut_t * pCut, * pCutBest;
If_Obj_t * pObj;
int i, c;
assert( nCuts >= 2 && nCuts <= 4 );
If_ManForEachNode( p, pObj, i )
{
pCutBest = NULL;
for ( c = 1; c < nCuts; c++ )
{
pCut = pObj->Cuts + c;
pCut->Delay = If_CutDelay( p, pCut );
pCut->Area = If_CutFlow( p, pCut );
assert( pCutBest || pCut->Delay < pObj->Required + p->fEpsilon );
if ( pCutBest == NULL ||
(pCut->Delay < pObj->Required + p->fEpsilon &&
pCut->Area < pCutBest->Area - p->fEpsilon) )
pCutBest = pCut;
}
assert( pCutBest != NULL );
// check if we need to move
if ( pCutBest != pObj->Cuts + 1 )
If_CutCopy( pObj->Cuts + 1, pCutBest );
// set the number of cuts
pObj->nCuts = 2;
}
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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