resSat.c 12.8 KB
Newer Older
Alan Mishchenko committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
/**CFile****************************************************************

  FileName    [resSat.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Resynthesis package.]

  Synopsis    [Interface with the SAT solver.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - January 15, 2007.]

  Revision    [$Id: resSat.c,v 1.00 2007/01/15 00:00:00 alanmi Exp $]

***********************************************************************/

21
#include "base/abc/abc.h"
Alan Mishchenko committed
22
#include "resInt.h"
23 24
#include "aig/hop/hop.h"
#include "sat/bsat/satSolver.h"
Alan Mishchenko committed
25

26 27 28
ABC_NAMESPACE_IMPL_START


Alan Mishchenko committed
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

extern int Res_SatAddConst1( sat_solver * pSat, int iVar, int fCompl );
extern int Res_SatAddEqual( sat_solver * pSat, int iVar0, int iVar1, int fCompl );
extern int Res_SatAddAnd( sat_solver * pSat, int iVar, int iVar0, int iVar1, int fCompl0, int fCompl1 );

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Loads AIG into the SAT solver for checking resubstitution.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Res_SatProveUnsat( Abc_Ntk_t * pAig, Vec_Ptr_t * vFanins )
{
    void * pCnf = NULL;
    sat_solver * pSat;
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pObj;
    int i, nNodes, status;

    // make sure fanins contain POs of the AIG
61
    pObj = (Abc_Obj_t *)Vec_PtrEntry( vFanins, 0 );
Alan Mishchenko committed
62 63 64 65 66 67 68
    assert( pObj->pNtk == pAig && Abc_ObjIsPo(pObj) );

    // collect reachable nodes
    vNodes = Abc_NtkDfsNodes( pAig, (Abc_Obj_t **)vFanins->pArray, vFanins->nSize );

    // assign unique numbers to each node
    nNodes = 0;
69
    Abc_AigConst1(pAig)->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
Alan Mishchenko committed
70
    Abc_NtkForEachPi( pAig, pObj, i )
71 72 73 74 75
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
    Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pObj, i ) // useful POs
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
Alan Mishchenko committed
76 77 78 79 80 81

    // start the solver
    pSat = sat_solver_new();
    sat_solver_store_alloc( pSat );

    // add clause for the constant node
Alan Mishchenko committed
82
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)Abc_AigConst1(pAig)->pCopy, 0 );
Alan Mishchenko committed
83
    // add clauses for AND gates
84
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
Alan Mishchenko committed
85 86
        Res_SatAddAnd( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 
            (int)(ABC_PTRUINT_T)Abc_ObjFanin0(pObj)->pCopy, (int)(ABC_PTRUINT_T)Abc_ObjFanin1(pObj)->pCopy, Abc_ObjFaninC0(pObj), Abc_ObjFaninC1(pObj) );
Alan Mishchenko committed
87 88
    Vec_PtrFree( vNodes );
    // add clauses for POs
89
    Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pObj, i )
Alan Mishchenko committed
90 91
        Res_SatAddEqual( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 
            (int)(ABC_PTRUINT_T)Abc_ObjFanin0(pObj)->pCopy, Abc_ObjFaninC0(pObj) );
Alan Mishchenko committed
92
    // add trivial clauses
93
    pObj = (Abc_Obj_t *)Vec_PtrEntry(vFanins, 0);
Alan Mishchenko committed
94
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 0 ); // care-set
95
    pObj = (Abc_Obj_t *)Vec_PtrEntry(vFanins, 1);
Alan Mishchenko committed
96
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 0 ); // on-set
Alan Mishchenko committed
97 98 99 100 101

    // bookmark the clauses of A
    sat_solver_store_mark_clauses_a( pSat );

    // duplicate the clauses
102
    pObj = (Abc_Obj_t *)Vec_PtrEntry(vFanins, 1);
Alan Mishchenko committed
103
    Sat_SolverDoubleClauses( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy );
Alan Mishchenko committed
104
    // add the equality constraints
105
    Vec_PtrForEachEntryStart( Abc_Obj_t *, vFanins, pObj, i, 2 )
Alan Mishchenko committed
106
        Res_SatAddEqual( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, ((int)(ABC_PTRUINT_T)pObj->pCopy) + nNodes, 0 );
Alan Mishchenko committed
107 108 109 110 111

    // bookmark the roots
    sat_solver_store_mark_roots( pSat );

    // solve the problem
Alan Mishchenko committed
112
    status = sat_solver_solve( pSat, NULL, NULL, (ABC_INT64_T)10000, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
Alan Mishchenko committed
113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
    if ( status == l_False )
    {
        pCnf = sat_solver_store_release( pSat );
//        printf( "unsat\n" );
    }
    else if ( status == l_True )
    {
//        printf( "sat\n" );
    }
    else
    {
//        printf( "undef\n" );
    }
    sat_solver_delete( pSat );
    return pCnf;
}

/**Function*************************************************************

  Synopsis    [Loads AIG into the SAT solver for constrained simulation.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Res_SatSimulateConstr( Abc_Ntk_t * pAig, int fOnSet )
{
    sat_solver * pSat;
    Vec_Ptr_t * vFanins;
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pObj;
    int i, nNodes;

    // start the array
    vFanins = Vec_PtrAlloc( 2 );
    pObj = Abc_NtkPo( pAig, 0 );
    Vec_PtrPush( vFanins, pObj );
    pObj = Abc_NtkPo( pAig, 1 );
    Vec_PtrPush( vFanins, pObj );

    // collect reachable nodes
    vNodes = Abc_NtkDfsNodes( pAig, (Abc_Obj_t **)vFanins->pArray, vFanins->nSize );

    // assign unique numbers to each node
    nNodes = 0;
161
    Abc_AigConst1(pAig)->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
Alan Mishchenko committed
162
    Abc_NtkForEachPi( pAig, pObj, i )
163 164 165 166 167
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
    Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pObj, i ) // useful POs
        pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)nNodes++;
Alan Mishchenko committed
168 169 170 171 172

    // start the solver
    pSat = sat_solver_new();

    // add clause for the constant node
Alan Mishchenko committed
173
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)Abc_AigConst1(pAig)->pCopy, 0 );
Alan Mishchenko committed
174
    // add clauses for AND gates
175
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
Alan Mishchenko committed
176 177
        Res_SatAddAnd( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 
            (int)(ABC_PTRUINT_T)Abc_ObjFanin0(pObj)->pCopy, (int)(ABC_PTRUINT_T)Abc_ObjFanin1(pObj)->pCopy, Abc_ObjFaninC0(pObj), Abc_ObjFaninC1(pObj) );
Alan Mishchenko committed
178 179 180
    Vec_PtrFree( vNodes );
    // add clauses for the first PO
    pObj = Abc_NtkPo( pAig, 0 );
Alan Mishchenko committed
181 182
    Res_SatAddEqual( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 
        (int)(ABC_PTRUINT_T)Abc_ObjFanin0(pObj)->pCopy, Abc_ObjFaninC0(pObj) );
Alan Mishchenko committed
183 184
    // add clauses for the second PO
    pObj = Abc_NtkPo( pAig, 1 );
Alan Mishchenko committed
185 186
    Res_SatAddEqual( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 
        (int)(ABC_PTRUINT_T)Abc_ObjFanin0(pObj)->pCopy, Abc_ObjFaninC0(pObj) );
Alan Mishchenko committed
187 188 189

    // add trivial clauses
    pObj = Abc_NtkPo( pAig, 0 );
Alan Mishchenko committed
190
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, 0 ); // care-set
Alan Mishchenko committed
191 192

    pObj = Abc_NtkPo( pAig, 1 );
Alan Mishchenko committed
193
    Res_SatAddConst1( pSat, (int)(ABC_PTRUINT_T)pObj->pCopy, !fOnSet ); // on-set
Alan Mishchenko committed
194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216

    Vec_PtrFree( vFanins );
    return pSat;
}

/**Function*************************************************************

  Synopsis    [Loads AIG into the SAT solver for constrained simulation.]

  Description [Returns 1 if the required number of patterns are found. 
  Returns 0 if the solver ran out of time or proved a constant. 
  In the latter, case one of the flags, fConst0 or fConst1, are set to 1.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Res_SatSimulate( Res_Sim_t * p, int nPatsLimit, int fOnSet )
{
    Vec_Int_t * vLits;
    Vec_Ptr_t * vPats;
    sat_solver * pSat;
Alan Mishchenko committed
217 218
    int RetValue = -1; // Suppress "might be used uninitialized"
    int i, k, value, status, Lit, Var, iPat;
219
    abctime clk = Abc_Clock();
Alan Mishchenko committed
220 221 222 223

//printf( "Looking for %s:  ", fOnSet? "onset " : "offset" );

    // decide what problem should be solved
Alan Mishchenko committed
224
    Lit = toLitCond( (int)(ABC_PTRUINT_T)Abc_NtkPo(p->pAig,1)->pCopy, !fOnSet );
Alan Mishchenko committed
225 226 227 228 229 230 231 232 233 234 235 236 237
    if ( fOnSet )
    {
        iPat = p->nPats1;
        vPats = p->vPats1;
    }
    else
    {
        iPat = p->nPats0;
        vPats = p->vPats0;
    }
    assert( iPat < nPatsLimit );

    // derive the SAT solver
238
    pSat = (sat_solver *)Res_SatSimulateConstr( p->pAig, fOnSet );
Alan Mishchenko committed
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259
    pSat->fSkipSimplify = 1;
    status = sat_solver_simplify( pSat );
    if ( status == 0 )
    {
        if ( iPat == 0 )
        {
//            if ( fOnSet )
//                p->fConst0 = 1;
//            else
//                p->fConst1 = 1;
            RetValue = 0;
        }
        goto finish;
    }
 
    // enumerate through the SAT assignments
    RetValue = 1;
    vLits = Vec_IntAlloc( 32 );
    for ( k = iPat; k < nPatsLimit; k++ )
    {
        // solve with the assumption
Alan Mishchenko committed
260 261
//        status = sat_solver_solve( pSat, &Lit, &Lit + 1, (ABC_INT64_T)10000, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
        status = sat_solver_solve( pSat, NULL, NULL, (ABC_INT64_T)10000, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
Alan Mishchenko committed
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280
        if ( status == l_False )
        {
//printf( "Const %d\n", !fOnSet );
            if ( k == 0 )
            {
                if ( fOnSet )
                    p->fConst0 = 1;
                else
                    p->fConst1 = 1;
                RetValue = 0;
            }
            break;
        }
        else if ( status == l_True )
        {
            // save the pattern
            Vec_IntClear( vLits );
            for ( i = 0; i < p->nTruePis; i++ )
            {
Alan Mishchenko committed
281
                Var = (int)(ABC_PTRUINT_T)Abc_NtkPi(p->pAig,i)->pCopy;
282 283
//                value = (int)(pSat->model.ptr[Var] == l_True);
                value = sat_solver_var_value(pSat, Var);
Alan Mishchenko committed
284
                if ( value )
285
                    Abc_InfoSetBit( (unsigned *)Vec_PtrEntry(vPats, i), k );
Alan Mishchenko committed
286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
                Lit = toLitCond( Var, value );
                Vec_IntPush( vLits, Lit );
//                printf( "%d", value );
            }
//            printf( "\n" );

            status = sat_solver_addclause( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits) );
            if ( status == 0 )
            {
                k++;
                RetValue = 1; 
                break;
            }
        }
        else
        {
//printf( "Undecided\n" );
            if ( k == 0 )
                RetValue = 0;
            else
                RetValue = 1; 
            break;
        }
    }
    Vec_IntFree( vLits );
//printf( "Found %d patterns\n", k - iPat );

    // set the new number of patterns
    if ( fOnSet )
        p->nPats1 = k;
    else
        p->nPats0 = k;

finish:

    sat_solver_delete( pSat );
322
p->timeSat += Abc_Clock() - clk;
Alan Mishchenko committed
323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
    return RetValue;
}


/**Function*************************************************************

  Synopsis    [Asserts equality of the variable to a constant.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Res_SatAddConst1( sat_solver * pSat, int iVar, int fCompl )
{
    lit Lit = toLitCond( iVar, fCompl );
    if ( !sat_solver_addclause( pSat, &Lit, &Lit + 1 ) )
        return 0;
    return 1;
}

/**Function*************************************************************

  Synopsis    [Asserts equality of two variables.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Res_SatAddEqual( sat_solver * pSat, int iVar0, int iVar1, int fCompl )
{
    lit Lits[2];

    Lits[0] = toLitCond( iVar0, 0 );
    Lits[1] = toLitCond( iVar1, !fCompl );
    if ( !sat_solver_addclause( pSat, Lits, Lits + 2 ) )
        return 0;

    Lits[0] = toLitCond( iVar0, 1 );
    Lits[1] = toLitCond( iVar1, fCompl );
    if ( !sat_solver_addclause( pSat, Lits, Lits + 2 ) )
        return 0;

    return 1;
}

/**Function*************************************************************

  Synopsis    [Adds constraints for the two-input AND-gate.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Res_SatAddAnd( sat_solver * pSat, int iVar, int iVar0, int iVar1, int fCompl0, int fCompl1 )
{
    lit Lits[3];

    Lits[0] = toLitCond( iVar, 1 );
    Lits[1] = toLitCond( iVar0, fCompl0 );
    if ( !sat_solver_addclause( pSat, Lits, Lits + 2 ) )
        return 0;

    Lits[0] = toLitCond( iVar, 1 );
    Lits[1] = toLitCond( iVar1, fCompl1 );
    if ( !sat_solver_addclause( pSat, Lits, Lits + 2 ) )
        return 0;

    Lits[0] = toLitCond( iVar, 0 );
    Lits[1] = toLitCond( iVar0, !fCompl0 );
    Lits[2] = toLitCond( iVar1, !fCompl1 );
    if ( !sat_solver_addclause( pSat, Lits, Lits + 3 ) )
        return 0;

    return 1;
}

////////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


413 414
ABC_NAMESPACE_IMPL_END