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/**CFile****************************************************************
FileName [saigLoc.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Sequential AIG package.]
Synopsis [K-step induction for one property only.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: saigLoc.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "saig.h"
#include "cnf.h"
#include "satSolver.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Performs localization by unrolling timeframes backward.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Saig_ManInduction( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose )
{
sat_solver * pSat;
Aig_Man_t * pAigPart;
Cnf_Dat_t * pCnfPart;
Vec_Int_t * vTopVarNums;
Vec_Ptr_t * vTop, * vBot;
Aig_Obj_t * pObjPi, * pObjPiCopy, * pObjPo;
int i, f, clk, Lits[2], status, RetValue, nSatVarNum, nConfPrev;
assert( Saig_ManPoNum(p) == 1 );
Aig_ManSetPioNumbers( p );
// start the top by including the PO
vBot = Vec_PtrAlloc( 100 );
vTop = Vec_PtrAlloc( 100 );
Vec_PtrPush( vTop, Aig_ManPo(p, 0) );
// start the array of CNF variables
vTopVarNums = Vec_IntAlloc( 100 );
// start the solver
pSat = sat_solver_new();
sat_solver_setnvars( pSat, 1000 );
// iterate backward unrolling
RetValue = -1;
nSatVarNum = 0;
if ( fVerbose )
printf( "Localization parameters: FramesMax = %5d. ConflictMax = %6d.\n", nFramesMax, nConfMax );
for ( f = 0; ; f++ )
{
if ( f > 0 )
{
Aig_ManStop( pAigPart );
Cnf_DataFree( pCnfPart );
}
clk = clock();
// get the bottom
Aig_SupportNodes( p, (Aig_Obj_t **)Vec_PtrArray(vTop), Vec_PtrSize(vTop), vBot );
// derive AIG for the part between top and bottom
pAigPart = Aig_ManDupSimpleDfsPart( p, vBot, vTop );
// convert it into CNF
pCnfPart = Cnf_Derive( pAigPart, Aig_ManPoNum(pAigPart) );
Cnf_DataLift( pCnfPart, nSatVarNum );
nSatVarNum += pCnfPart->nVars;
// stitch variables of top and bot
assert( Aig_ManPoNum(pAigPart)-1 == Vec_IntSize(vTopVarNums) );
Aig_ManForEachPo( pAigPart, pObjPo, i )
{
if ( i == 0 )
{
// do not perform inductive strengthening
// if ( f > 0 )
// continue;
// add topmost literal
Lits[0] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], f>0 );
if ( !sat_solver_addclause( pSat, Lits, Lits+1 ) )
assert( 0 );
continue;
}
Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i-1), 0 );
Lits[1] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], 1 );
if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
assert( 0 );
Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i-1), 1 );
Lits[1] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], 0 );
if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
assert( 0 );
}
// add CNF to the SAT solver
for ( i = 0; i < pCnfPart->nClauses; i++ )
if ( !sat_solver_addclause( pSat, pCnfPart->pClauses[i], pCnfPart->pClauses[i+1] ) )
break;
if ( i < pCnfPart->nClauses )
{
// printf( "SAT solver became UNSAT after adding clauses.\n" );
RetValue = 1;
break;
}
// run the SAT solver
nConfPrev = pSat->stats.conflicts;
status = sat_solver_solve( pSat, NULL, NULL, (ABC_INT64_T)nConfMax, 0, 0, 0 );
if ( fVerbose )
{
printf( "%3d : PI = %5d. PO = %5d. AIG = %5d. Var = %6d. Conf = %6d. ",
f+1, Aig_ManPiNum(pAigPart), Aig_ManPoNum(pAigPart), Aig_ManNodeNum(pAigPart),
nSatVarNum, pSat->stats.conflicts-nConfPrev );
ABC_PRT( "Time", clock() - clk );
}
if ( status == l_Undef )
break;
if ( status == l_False )
{
RetValue = 1;
break;
}
assert( status == l_True );
if ( f == nFramesMax - 1 )
break;
// the problem is SAT - add more clauses
// create new set of POs to derive new top
Vec_PtrClear( vTop );
Vec_PtrPush( vTop, Aig_ManPo(p, 0) );
Vec_IntClear( vTopVarNums );
Vec_PtrForEachEntry( vBot, pObjPi, i )
{
assert( Aig_ObjIsPi(pObjPi) );
if ( Saig_ObjIsLo(p, pObjPi) )
{
pObjPiCopy = pObjPi->pData;
assert( pObjPiCopy != NULL );
Vec_PtrPush( vTop, Saig_ObjLoToLi(p, pObjPi) );
Vec_IntPush( vTopVarNums, pCnfPart->pVarNums[pObjPiCopy->Id] );
}
}
}
// printf( "Completed %d interations.\n", f+1 );
// cleanup
sat_solver_delete( pSat );
Aig_ManStop( pAigPart );
Cnf_DataFree( pCnfPart );
Vec_IntFree( vTopVarNums );
Vec_PtrFree( vTop );
Vec_PtrFree( vBot );
return RetValue;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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