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/**CFile****************************************************************
FileName [lpkMux.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Fast Boolean matching for LUT structures.]
Synopsis []
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - April 28, 2007.]
Revision [$Id: lpkMux.c,v 1.00 2007/04/28 00:00:00 alanmi Exp $]
***********************************************************************/
#include "lpkInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Find the best cofactoring variable.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Lpk_MapTreeBestCofVar( Lpk_Man_t * p, unsigned * pTruth, int nVars, unsigned * pCof0, unsigned * pCof1 )
{
int i, iBestVar, nSuppSizeCur0, nSuppSizeCur1, nSuppSizeCur, nSuppSizeMin;
// iterate through variables
iBestVar = -1;
nSuppSizeMin = KIT_INFINITY;
for ( i = 0; i < nVars; i++ )
{
// cofactor the functiona and get support sizes
Kit_TruthCofactor0New( pCof0, pTruth, nVars, i );
Kit_TruthCofactor1New( pCof1, pTruth, nVars, i );
nSuppSizeCur0 = Kit_TruthSupportSize( pCof0, nVars );
nSuppSizeCur1 = Kit_TruthSupportSize( pCof1, nVars );
nSuppSizeCur = nSuppSizeCur0 + nSuppSizeCur1;
// skip cofactoring that goes above the limit
if ( nSuppSizeCur0 > p->pPars->nLutSize || nSuppSizeCur1 > p->pPars->nLutSize )
continue;
// compare this variable with other variables
if ( nSuppSizeMin > nSuppSizeCur )
{
nSuppSizeMin = nSuppSizeCur;
iBestVar = i;
}
}
// cofactor w.r.t. this variable
if ( iBestVar != -1 )
{
Kit_TruthCofactor0New( pCof0, pTruth, nVars, iBestVar );
Kit_TruthCofactor1New( pCof1, pTruth, nVars, iBestVar );
}
return iBestVar;
}
/**Function*************************************************************
Synopsis [Maps the function by the best cofactoring.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
If_Obj_t * Lpk_MapTreeMux_rec( Lpk_Man_t * p, unsigned * pTruth, int nVars, If_Obj_t ** ppLeaves )
{
unsigned * pCof0 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 0 );
unsigned * pCof1 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 1 );
If_Obj_t * pObj0, * pObj1;
Kit_DsdNtk_t * ppNtks[2];
int iBestVar;
assert( nVars > 3 );
p->fCalledOnce = 1;
// cofactor w.r.t. the best variable
iBestVar = Lpk_MapTreeBestCofVar( p, pTruth, nVars, pCof0, pCof1 );
if ( iBestVar == -1 )
return NULL;
// decompose the functions
ppNtks[0] = Kit_DsdDecompose( pCof0, nVars );
ppNtks[1] = Kit_DsdDecompose( pCof1, nVars );
if ( p->pPars->fVeryVerbose )
{
printf( "Cofactoring w.r.t. var %c (%d -> %d+%d supp vars):\n",
'a'+iBestVar, nVars, Kit_TruthSupportSize(pCof0, nVars), Kit_TruthSupportSize(pCof1, nVars) );
Kit_DsdPrintExpanded( ppNtks[0] );
Kit_DsdPrintExpanded( ppNtks[1] );
}
// map the DSD structures
pObj0 = Lpk_MapTree_rec( p, ppNtks[0], ppLeaves, ppNtks[0]->Root, NULL );
pObj1 = Lpk_MapTree_rec( p, ppNtks[1], ppLeaves, ppNtks[1]->Root, NULL );
Kit_DsdNtkFree( ppNtks[0] );
Kit_DsdNtkFree( ppNtks[1] );
return If_ManCreateMux( p->pIfMan, pObj0, pObj1, ppLeaves[iBestVar] );
}
/**Function*************************************************************
Synopsis [Implements support-reducing decomposition.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
If_Obj_t * Lpk_MapSuppRedDec_rec( Lpk_Man_t * p, unsigned * pTruth, int nVars, If_Obj_t ** ppLeaves )
{
Kit_DsdNtk_t * pNtkDec, * pNtkComp, * ppNtks[2], * pTemp;
If_Obj_t * pObjNew;
unsigned * pCof0 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 0 );
unsigned * pCof1 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 1 );
unsigned * pDec0 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 2 );
unsigned * pDec1 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 3 );
unsigned * pDec = (unsigned *)Vec_PtrEntry( p->vTtNodes, 4 );
unsigned * pCo00 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 5 );
unsigned * pCo01 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 6 );
unsigned * pCo10 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 7 );
unsigned * pCo11 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 8 );
unsigned * pCo0 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 9 );
unsigned * pCo1 = (unsigned *)Vec_PtrEntry( p->vTtNodes, 10 );
unsigned * pCo = (unsigned *)Vec_PtrEntry( p->vTtNodes, 11 );
int TrueMint0, TrueMint1, FalseMint0, FalseMint1;
int uSubsets, uSubset0, uSubset1, iVar, iVarReused, i;
// determine if supp-red decomposition exists
uSubsets = Lpk_MapSuppRedDecSelect( p, pTruth, nVars, &iVar, &iVarReused );
if ( uSubsets == 0 )
return NULL;
p->nCalledSRed++;
// get the cofactors
Kit_TruthCofactor0New( pCof0, pTruth, nVars, iVar );
Kit_TruthCofactor1New( pCof1, pTruth, nVars, iVar );
// get the bound sets
uSubset0 = uSubsets & 0xFFFF;
uSubset1 = uSubsets >> 16;
// compute the decomposed functions
ppNtks[0] = Kit_DsdDecompose( pCof0, nVars );
ppNtks[1] = Kit_DsdDecompose( pCof1, nVars );
ppNtks[0] = Kit_DsdExpand( pTemp = ppNtks[0] ); Kit_DsdNtkFree( pTemp );
ppNtks[1] = Kit_DsdExpand( pTemp = ppNtks[1] ); Kit_DsdNtkFree( pTemp );
Kit_DsdTruthPartial( p->pDsdMan, ppNtks[0], pDec0, uSubset0 );
Kit_DsdTruthPartial( p->pDsdMan, ppNtks[1], pDec1, uSubset1 );
// Kit_DsdTruthPartialTwo( p->pDsdMan, ppNtks[0], uSubset0, iVarReused, pCo0, pDec0 );
// Kit_DsdTruthPartialTwo( p->pDsdMan, ppNtks[1], uSubset1, iVarReused, pCo1, pDec1 );
Kit_DsdNtkFree( ppNtks[0] );
Kit_DsdNtkFree( ppNtks[1] );
//Kit_DsdPrintFromTruth( pDec0, nVars );
//Kit_DsdPrintFromTruth( pDec1, nVars );
// get the decomposed function
Kit_TruthMuxVar( pDec, pDec0, pDec1, nVars, iVar );
// find any true assignments of the decomposed functions
TrueMint0 = Kit_TruthFindFirstBit( pDec0, nVars );
TrueMint1 = Kit_TruthFindFirstBit( pDec1, nVars );
assert( TrueMint0 >= 0 && TrueMint1 >= 0 );
// find any false assignments of the decomposed functions
FalseMint0 = Kit_TruthFindFirstZero( pDec0, nVars );
FalseMint1 = Kit_TruthFindFirstZero( pDec1, nVars );
assert( FalseMint0 >= 0 && FalseMint1 >= 0 );
// cofactor the cofactors according to these minterms
Kit_TruthCopy( pCo00, pCof0, nVars );
Kit_TruthCopy( pCo01, pCof0, nVars );
for ( i = 0; i < nVars; i++ )
if ( uSubset0 & (1 << i) )
{
if ( FalseMint0 & (1 << i) )
Kit_TruthCofactor1( pCo00, nVars, i );
else
Kit_TruthCofactor0( pCo00, nVars, i );
if ( TrueMint0 & (1 << i) )
Kit_TruthCofactor1( pCo01, nVars, i );
else
Kit_TruthCofactor0( pCo01, nVars, i );
}
Kit_TruthCopy( pCo10, pCof1, nVars );
Kit_TruthCopy( pCo11, pCof1, nVars );
for ( i = 0; i < nVars; i++ )
if ( uSubset1 & (1 << i) )
{
if ( FalseMint1 & (1 << i) )
Kit_TruthCofactor1( pCo10, nVars, i );
else
Kit_TruthCofactor0( pCo10, nVars, i );
if ( TrueMint1 & (1 << i) )
Kit_TruthCofactor1( pCo11, nVars, i );
else
Kit_TruthCofactor0( pCo11, nVars, i );
}
// derive the functions by composing them with the new variable (iVarReused)
Kit_TruthMuxVar( pCo0, pCo00, pCo01, nVars, iVarReused );
Kit_TruthMuxVar( pCo1, pCo10, pCo11, nVars, iVarReused );
//Kit_DsdPrintFromTruth( pCo0, nVars );
//Kit_DsdPrintFromTruth( pCo1, nVars );
// derive the composition function
Kit_TruthMuxVar( pCo , pCo0 , pCo1 , nVars, iVar );
// process the decomposed function
pNtkDec = Kit_DsdDecompose( pDec, nVars );
pNtkComp = Kit_DsdDecompose( pCo, nVars );
//Kit_DsdPrint( stdout, pNtkDec );
//Kit_DsdPrint( stdout, pNtkComp );
//printf( "cofactored variable %c\n", 'a' + iVar );
//printf( "reused variable %c\n", 'a' + iVarReused );
ppLeaves[iVarReused] = Lpk_MapTree_rec( p, pNtkDec, ppLeaves, pNtkDec->Root, NULL );
pObjNew = Lpk_MapTree_rec( p, pNtkComp, ppLeaves, pNtkComp->Root, NULL );
Kit_DsdNtkFree( pNtkDec );
Kit_DsdNtkFree( pNtkComp );
return pObjNew;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
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