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/**CFile****************************************************************
FileName [mfsInter.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [The good old minimization with complete don't-cares.]
Synopsis [Procedures for computing resub function by interpolation.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: mfsInter.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "mfsInt.h"
#include "kit.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Adds constraints for the two-input AND-gate.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_MfsSatAddXor( sat_solver * pSat, int iVarA, int iVarB, int iVarC )
{
lit Lits[3];
Lits[0] = toLitCond( iVarA, 1 );
Lits[1] = toLitCond( iVarB, 1 );
Lits[2] = toLitCond( iVarC, 1 );
if ( !sat_solver_addclause( pSat, Lits, Lits + 3 ) )
return 0;
Lits[0] = toLitCond( iVarA, 1 );
Lits[1] = toLitCond( iVarB, 0 );
Lits[2] = toLitCond( iVarC, 0 );
if ( !sat_solver_addclause( pSat, Lits, Lits + 3 ) )
return 0;
Lits[0] = toLitCond( iVarA, 0 );
Lits[1] = toLitCond( iVarB, 1 );
Lits[2] = toLitCond( iVarC, 0 );
if ( !sat_solver_addclause( pSat, Lits, Lits + 3 ) )
return 0;
Lits[0] = toLitCond( iVarA, 0 );
Lits[1] = toLitCond( iVarB, 0 );
Lits[2] = toLitCond( iVarC, 1 );
if ( !sat_solver_addclause( pSat, Lits, Lits + 3 ) )
return 0;
return 1;
}
/**Function*************************************************************
Synopsis [Creates miter for checking resubsitution.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
sat_solver * Abc_MfsCreateSolverResub( Mfs_Man_t * p, int * pCands, int nCands )
{
sat_solver * pSat;
Aig_Obj_t * pObjPo;
int Lits[2], status, iVar, i, c;
// get the literal for the output of F
pObjPo = Aig_ManPo( p->pAigWin, Aig_ManPoNum(p->pAigWin) - Vec_PtrSize(p->vDivs) - 1 );
Lits[0] = toLitCond( p->pCnf->pVarNums[pObjPo->Id], 0 );
// collect the outputs of the divisors
Vec_IntClear( p->vProjVars );
Vec_PtrForEachEntryStart( p->pAigWin->vPos, pObjPo, i, Aig_ManPoNum(p->pAigWin) - Vec_PtrSize(p->vDivs) )
{
assert( p->pCnf->pVarNums[pObjPo->Id] >= 0 );
Vec_IntPush( p->vProjVars, p->pCnf->pVarNums[pObjPo->Id] );
}
assert( Vec_IntSize(p->vProjVars) == Vec_PtrSize(p->vDivs) );
// start the solver
pSat = sat_solver_new();
sat_solver_setnvars( pSat, 2 * p->pCnf->nVars + Vec_PtrSize(p->vDivs) );
if ( pCands )
sat_solver_store_alloc( pSat );
// load the first copy of the clauses
for ( i = 0; i < p->pCnf->nClauses; i++ )
{
if ( !sat_solver_addclause( pSat, p->pCnf->pClauses[i], p->pCnf->pClauses[i+1] ) )
{
sat_solver_delete( pSat );
return NULL;
}
}
// add the clause for the first output of F
if ( !sat_solver_addclause( pSat, Lits, Lits+1 ) )
{
sat_solver_delete( pSat );
return NULL;
}
// bookmark the clauses of A
if ( pCands )
sat_solver_store_mark_clauses_a( pSat );
// transform the literals
for ( i = 0; i < p->pCnf->nLiterals; i++ )
p->pCnf->pClauses[0][i] += 2 * p->pCnf->nVars;
// load the second copy of the clauses
for ( i = 0; i < p->pCnf->nClauses; i++ )
{
if ( !sat_solver_addclause( pSat, p->pCnf->pClauses[i], p->pCnf->pClauses[i+1] ) )
{
sat_solver_delete( pSat );
return NULL;
}
}
// transform the literals
for ( i = 0; i < p->pCnf->nLiterals; i++ )
p->pCnf->pClauses[0][i] -= 2 * p->pCnf->nVars;
// add the clause for the second output of F
Lits[0] = 2 * p->pCnf->nVars + lit_neg( Lits[0] );
if ( !sat_solver_addclause( pSat, Lits, Lits+1 ) )
{
sat_solver_delete( pSat );
return NULL;
}
if ( pCands )
{
// add relevant clauses for EXOR gates
for ( c = 0; c < nCands; c++ )
{
// get the variable number of this divisor
i = lit_var( pCands[c] ) - 2 * p->pCnf->nVars;
// get the corresponding SAT variable
iVar = Vec_IntEntry( p->vProjVars, i );
// add the corresponding EXOR gate
if ( !Abc_MfsSatAddXor( pSat, iVar, iVar + p->pCnf->nVars, 2 * p->pCnf->nVars + i ) )
{
sat_solver_delete( pSat );
return NULL;
}
// add the corresponding clause
if ( !sat_solver_addclause( pSat, pCands + c, pCands + c + 1 ) )
{
sat_solver_delete( pSat );
return NULL;
}
}
// bookmark the roots
sat_solver_store_mark_roots( pSat );
}
else
{
// add the clauses for the EXOR gates - and remember their outputs
Vec_IntForEachEntry( p->vProjVars, iVar, i )
{
if ( !Abc_MfsSatAddXor( pSat, iVar, iVar + p->pCnf->nVars, 2 * p->pCnf->nVars + i ) )
{
sat_solver_delete( pSat );
return NULL;
}
Vec_IntWriteEntry( p->vProjVars, i, 2 * p->pCnf->nVars + i );
}
// simplify the solver
status = sat_solver_simplify(pSat);
if ( status == 0 )
{
// printf( "Abc_MfsCreateSolverResub(): SAT solver construction has failed. Skipping node.\n" );
sat_solver_delete( pSat );
return NULL;
}
}
return pSat;
}
/**Function*************************************************************
Synopsis [Performs interpolation.]
Description [Derives the new function of the node.]
SideEffects []
SeeAlso []
***********************************************************************/
Hop_Obj_t * Abc_NtkMfsInterplate( Mfs_Man_t * p, int * pCands, int nCands )
{
extern Hop_Obj_t * Kit_GraphToHop( Hop_Man_t * pMan, Kit_Graph_t * pGraph );
sat_solver * pSat;
Sto_Man_t * pCnf = NULL;
unsigned * puTruth;
Kit_Graph_t * pGraph;
Hop_Obj_t * pFunc;
int nFanins, status;
// derive the SAT solver for interpolation
pSat = Abc_MfsCreateSolverResub( p, pCands, nCands );
// solve the problem
status = sat_solver_solve( pSat, NULL, NULL, (sint64)0, (sint64)0, (sint64)0, (sint64)0 );
if ( status != l_False )
{
printf( "Abc_NtkMfsInterplate(): Internal error. The problem is not UNSAT.\n" );
return NULL;
}
// get the learned clauses
pCnf = sat_solver_store_release( pSat );
sat_solver_delete( pSat );
// derive the interpolant
nFanins = Int_ManInterpolate( p->pMan, pCnf, 0, &puTruth );
Sto_ManFree( pCnf );
assert( nFanins == nCands );
// transform interpolant into AIG
pGraph = Kit_TruthToGraph( puTruth, nFanins, p->vMem );
pFunc = Kit_GraphToHop( p->pNtk->pManFunc, pGraph );
Kit_GraphFree( pGraph );
return pFunc;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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