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/**CFile****************************************************************
FileName [mfsSat.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [The good old minimization with complete don't-cares.]
Synopsis [Procedures to compute don't-cares using SAT.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: mfsSat.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "mfsInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Enumerates through the SAT assignments.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsSolveSat_iter( Mfs_Man_t * p )
{
int Lits[MFS_FANIN_MAX];
int RetValue, nBTLimit, iVar, b, Mint;
// int nConfs = p->pSat->stats.conflicts;
if ( p->nTotConfLim && p->nTotConfLim <= p->pSat->stats.conflicts )
return -1;
nBTLimit = p->nTotConfLim? p->nTotConfLim - p->pSat->stats.conflicts : 0;
RetValue = sat_solver_solve( p->pSat, NULL, NULL, (ABC_INT64_T)nBTLimit, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
assert( RetValue == l_Undef || RetValue == l_True || RetValue == l_False );
//printf( "%c", RetValue==l_Undef ? '?' : (RetValue==l_False ? '-' : '+') );
//printf( "%d ", p->pSat->stats.conflicts-nConfs );
//if ( RetValue==l_False )
//printf( "\n" );
if ( RetValue == l_Undef )
return -1;
if ( RetValue == l_False )
return 0;
p->nCares++;
// add SAT assignment to the solver
Mint = 0;
Vec_IntForEachEntry( p->vProjVarsSat, iVar, b )
{
Lits[b] = toLit( iVar );
if ( sat_solver_var_value( p->pSat, iVar ) )
{
Mint |= (1 << b);
Lits[b] = lit_neg( Lits[b] );
}
}
assert( !Aig_InfoHasBit(p->uCare, Mint) );
Aig_InfoSetBit( p->uCare, Mint );
// add the blocking clause
RetValue = sat_solver_addclause( p->pSat, Lits, Lits + Vec_IntSize(p->vProjVarsSat) );
if ( RetValue == 0 )
return 0;
return 1;
}
/**Function*************************************************************
Synopsis [Enumerates through the SAT assignments.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsSolveSat( Mfs_Man_t * p, Abc_Obj_t * pNode )
{
Aig_Obj_t * pObjPo;
int RetValue, i;
// collect projection variables
Vec_IntClear( p->vProjVarsSat );
Vec_PtrForEachEntryStart( Aig_Obj_t *, p->pAigWin->vPos, pObjPo, i, Aig_ManPoNum(p->pAigWin) - Abc_ObjFaninNum(pNode) )
{
assert( p->pCnf->pVarNums[pObjPo->Id] >= 0 );
Vec_IntPush( p->vProjVarsSat, p->pCnf->pVarNums[pObjPo->Id] );
}
// prepare the truth table of care set
p->nFanins = Vec_IntSize( p->vProjVarsSat );
p->nWords = Aig_TruthWordNum( p->nFanins );
memset( p->uCare, 0, sizeof(unsigned) * p->nWords );
// iterate through the SAT assignments
p->nCares = 0;
p->nTotConfLim = p->pPars->nBTLimit;
while ( (RetValue = Abc_NtkMfsSolveSat_iter(p)) == 1 );
if ( RetValue == -1 )
return 0;
// write statistics
p->nMintsCare += p->nCares;
p->nMintsTotal += (1<<p->nFanins);
if ( p->pPars->fVeryVerbose )
{
printf( "Node %4d : Care = %2d. Total = %2d. ", pNode->Id, p->nCares, (1<<p->nFanins) );
Extra_PrintBinary( stdout, p->uCare, (1<<p->nFanins) );
printf( "\n" );
}
// map the care
if ( p->nFanins > 4 )
return 1;
if ( p->nFanins == 4 )
p->uCare[0] = p->uCare[0] | (p->uCare[0] << 16);
if ( p->nFanins == 3 )
p->uCare[0] = p->uCare[0] | (p->uCare[0] << 8) | (p->uCare[0] << 16) | (p->uCare[0] << 24);
if ( p->nFanins == 2 )
p->uCare[0] = p->uCare[0] | (p->uCare[0] << 4) | (p->uCare[0] << 8) | (p->uCare[0] << 12) |
(p->uCare[0] << 16) | (p->uCare[0] << 20) | (p->uCare[0] << 24) | (p->uCare[0] << 28);
assert( p->nFanins != 1 );
return 1;
}
/**Function*************************************************************
Synopsis [Adds one-hotness constraints for the window inputs.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkAddOneHotness( Mfs_Man_t * p )
{
Aig_Obj_t * pObj1, * pObj2;
int i, k, Lits[2];
for ( i = 0; i < Vec_PtrSize(p->pAigWin->vPis); i++ )
for ( k = i+1; k < Vec_PtrSize(p->pAigWin->vPis); k++ )
{
pObj1 = Aig_ManPi( p->pAigWin, i );
pObj2 = Aig_ManPi( p->pAigWin, k );
Lits[0] = toLitCond( p->pCnf->pVarNums[pObj1->Id], 1 );
Lits[1] = toLitCond( p->pCnf->pVarNums[pObj2->Id], 1 );
if ( !sat_solver_addclause( p->pSat, Lits, Lits+2 ) )
{
sat_solver_delete( p->pSat );
p->pSat = NULL;
return 0;
}
}
return 1;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
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