summaryrefslogtreecommitdiffstats
path: root/src/base/abci/abcNtbdd.c
blob: a55ea227ab4724a7ce3d4e8fb6bf854bbd9d4ed6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
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
322
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
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
/**CFile****************************************************************

  FileName    [abcNtbdd.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Network and node package.]

  Synopsis    [Procedures to translate between the BDD and the network.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

  Revision    [$Id: abcNtbdd.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

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

#include "base/abc/abc.h"
#include "aig/saig/saig.h"

#ifdef ABC_USE_CUDD
#include "bdd/extrab/extraBdd.h"
#endif

ABC_NAMESPACE_IMPL_START


////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

#ifdef ABC_USE_CUDD

static void        Abc_NtkBddToMuxesPerform( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew );
static Abc_Obj_t * Abc_NodeBddToMuxes( Abc_Obj_t * pNodeOld, Abc_Ntk_t * pNtkNew );
static Abc_Obj_t * Abc_NodeBddToMuxes_rec( DdManager * dd, DdNode * bFunc, Abc_Ntk_t * pNtkNew, st__table * tBdd2Node );
static DdNode *    Abc_NodeGlobalBdds_rec( DdManager * dd, Abc_Obj_t * pNode, int nBddSizeMax, int fDropInternal, ProgressBar * pProgress, int * pCounter, int fVerbose );

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

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

  Synopsis    [Constructs the network isomorphic to the given BDD.]

  Description [Assumes that the BDD depends on the variables whose indexes
  correspond to the names in the array (pNamesPi). Otherwise, returns NULL.
  The resulting network comes with one node, whose functionality is
  equal to the given BDD. To decompose this BDD into the network of
  multiplexers use Abc_NtkBddToMuxes(). To decompose this BDD into
  an And-Inverter Graph, use Abc_NtkStrash().]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Ntk_t * Abc_NtkDeriveFromBdd( void * dd0, void * bFunc, char * pNamePo, Vec_Ptr_t * vNamesPi )
{
    DdManager * dd = (DdManager *)dd0;
    Abc_Ntk_t * pNtk; 
    Vec_Ptr_t * vNamesPiFake = NULL;
    Abc_Obj_t * pNode, * pNodePi, * pNodePo;
    DdNode * bSupp, * bTemp;
    char * pName;
    int i;

    // supply fake names if real names are not given
    if ( pNamePo == NULL )
        pNamePo = "F";
    if ( vNamesPi == NULL )
    {
        vNamesPiFake = Abc_NodeGetFakeNames( dd->size );
        vNamesPi = vNamesPiFake;
    }

    // make sure BDD depends on the variables whose index 
    // does not exceed the size of the array with PI names
    bSupp = Cudd_Support( dd, (DdNode *)bFunc );   Cudd_Ref( bSupp );
    for ( bTemp = bSupp; bTemp != Cudd_ReadOne(dd); bTemp = cuddT(bTemp) )
        if ( (int)Cudd_NodeReadIndex(bTemp) >= Vec_PtrSize(vNamesPi) )
            break;
    Cudd_RecursiveDeref( dd, bSupp );
    if ( bTemp != Cudd_ReadOne(dd) )
        return NULL;

    // start the network
    pNtk = Abc_NtkAlloc( ABC_NTK_LOGIC, ABC_FUNC_BDD, 1 );
    pNtk->pName = Extra_UtilStrsav(pNamePo);
    // make sure the new manager has enough inputs
    Cudd_bddIthVar( (DdManager *)pNtk->pManFunc, Vec_PtrSize(vNamesPi) );
    // add the PIs corresponding to the names
    Vec_PtrForEachEntry( char *, vNamesPi, pName, i )
        Abc_ObjAssignName( Abc_NtkCreatePi(pNtk), pName, NULL );
    // create the node
    pNode = Abc_NtkCreateNode( pNtk );
    pNode->pData = (DdNode *)Cudd_bddTransfer( dd, (DdManager *)pNtk->pManFunc, (DdNode *)bFunc ); Cudd_Ref((DdNode *)pNode->pData);
    Abc_NtkForEachPi( pNtk, pNodePi, i )
        Abc_ObjAddFanin( pNode, pNodePi );
    // create the only PO
    pNodePo = Abc_NtkCreatePo( pNtk );
    Abc_ObjAddFanin( pNodePo, pNode );
    Abc_ObjAssignName( pNodePo, pNamePo, NULL );
    // make the network minimum base
    Abc_NtkMinimumBase( pNtk );
    if ( vNamesPiFake )
        Abc_NodeFreeNames( vNamesPiFake );
    if ( !Abc_NtkCheck( pNtk ) )
        fprintf( stdout, "Abc_NtkDeriveFromBdd(): Network check has failed.\n" );
    return pNtk;
}



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

  Synopsis    [Creates the network isomorphic to the union of local BDDs of the nodes.]

  Description [The nodes of the local BDDs are converted into the network nodes 
  with logic functions equal to the MUX.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Ntk_t * Abc_NtkBddToMuxes( Abc_Ntk_t * pNtk )
{
    Abc_Ntk_t * pNtkNew;
    assert( Abc_NtkIsBddLogic(pNtk) );
    pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_LOGIC, ABC_FUNC_SOP );
    Abc_NtkBddToMuxesPerform( pNtk, pNtkNew );
    Abc_NtkFinalize( pNtk, pNtkNew );
    // make sure everything is okay
    if ( !Abc_NtkCheck( pNtkNew ) )
    {
        printf( "Abc_NtkBddToMuxes: The network check has failed.\n" );
        Abc_NtkDelete( pNtkNew );
        return NULL;
    }
    return pNtkNew;
}

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

  Synopsis    [Converts the network to MUXes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkBddToMuxesPerform( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew )
{
    ProgressBar * pProgress;
    Abc_Obj_t * pNode, * pNodeNew;
    Vec_Ptr_t * vNodes;
    int i;
    // perform conversion in the topological order
    vNodes = Abc_NtkDfs( pNtk, 0 );
    pProgress = Extra_ProgressBarStart( stdout, vNodes->nSize );
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
    {
        Extra_ProgressBarUpdate( pProgress, i, NULL );
        // convert one node
        assert( Abc_ObjIsNode(pNode) );
        pNodeNew = Abc_NodeBddToMuxes( pNode, pNtkNew );
        // mark the old node with the new one
        assert( pNode->pCopy == NULL );
        pNode->pCopy = pNodeNew;
    }
    Vec_PtrFree( vNodes );
    Extra_ProgressBarStop( pProgress );
}

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

  Synopsis    [Converts the node to MUXes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Obj_t * Abc_NodeBddToMuxes( Abc_Obj_t * pNodeOld, Abc_Ntk_t * pNtkNew )
{
    DdManager * dd = (DdManager *)pNodeOld->pNtk->pManFunc;
    DdNode * bFunc = (DdNode *)pNodeOld->pData;
    Abc_Obj_t * pFaninOld, * pNodeNew;
    st__table * tBdd2Node;
    int i;
    // create the table mapping BDD nodes into the ABC nodes
    tBdd2Node = st__init_table( st__ptrcmp, st__ptrhash );
    // add the constant and the elementary vars
    Abc_ObjForEachFanin( pNodeOld, pFaninOld, i )
        st__insert( tBdd2Node, (char *)Cudd_bddIthVar(dd, i), (char *)pFaninOld->pCopy );
    // create the new nodes recursively
    pNodeNew = Abc_NodeBddToMuxes_rec( dd, Cudd_Regular(bFunc), pNtkNew, tBdd2Node );
    st__free_table( tBdd2Node );
    if ( Cudd_IsComplement(bFunc) )
        pNodeNew = Abc_NtkCreateNodeInv( pNtkNew, pNodeNew );
    return pNodeNew;
}

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

  Synopsis    [Converts the node to MUXes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Abc_Obj_t * Abc_NodeBddToMuxes_rec( DdManager * dd, DdNode * bFunc, Abc_Ntk_t * pNtkNew, st__table * tBdd2Node )
{
    Abc_Obj_t * pNodeNew, * pNodeNew0, * pNodeNew1, * pNodeNewC;
    assert( !Cudd_IsComplement(bFunc) );
    if ( bFunc == b1 )
        return Abc_NtkCreateNodeConst1(pNtkNew);
    if ( st__lookup( tBdd2Node, (char *)bFunc, (char **)&pNodeNew ) )
        return pNodeNew;
    // solve for the children nodes
    pNodeNew0 = Abc_NodeBddToMuxes_rec( dd, Cudd_Regular(cuddE(bFunc)), pNtkNew, tBdd2Node );
    if ( Cudd_IsComplement(cuddE(bFunc)) )
        pNodeNew0 = Abc_NtkCreateNodeInv( pNtkNew, pNodeNew0 );
    pNodeNew1 = Abc_NodeBddToMuxes_rec( dd, cuddT(bFunc), pNtkNew, tBdd2Node );
    if ( ! st__lookup( tBdd2Node, (char *)Cudd_bddIthVar(dd, bFunc->index), (char **)&pNodeNewC ) )
        assert( 0 );
    // create the MUX node
    pNodeNew = Abc_NtkCreateNodeMux( pNtkNew, pNodeNewC, pNodeNew1, pNodeNew0 );
    st__insert( tBdd2Node, (char *)bFunc, (char *)pNodeNew );
    return pNodeNew;
}


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

  Synopsis    [Derives global BDDs for the COs of the network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Abc_NtkBuildGlobalBdds( Abc_Ntk_t * pNtk, int nBddSizeMax, int fDropInternal, int fReorder, int fReverse, int fVerbose )
{
    ProgressBar * pProgress;
    Abc_Obj_t * pObj, * pFanin;
    Vec_Att_t * pAttMan;
    DdManager * dd;
    DdNode * bFunc;
    int i, k, Counter;

    // remove dangling nodes
    Abc_AigCleanup( (Abc_Aig_t *)pNtk->pManFunc );

    // start the manager
    assert( Abc_NtkGlobalBdd(pNtk) == NULL );
    dd = Cudd_Init( Abc_NtkCiNum(pNtk), 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
    pAttMan = Vec_AttAlloc( Abc_NtkObjNumMax(pNtk) + 1, dd, (void (*)(void*))Extra_StopManager, NULL, (void (*)(void*,void*))Cudd_RecursiveDeref );
    Vec_PtrWriteEntry( pNtk->vAttrs, VEC_ATTR_GLOBAL_BDD, pAttMan );

    // set reordering
    if ( fReorder )
        Cudd_AutodynEnable( dd, CUDD_REORDER_SYMM_SIFT );

    // assign the constant node BDD
    pObj = Abc_AigConst1(pNtk);
    if ( Abc_ObjFanoutNum(pObj) > 0 )
    {
        bFunc = dd->one;
        Abc_ObjSetGlobalBdd( pObj, bFunc );   Cudd_Ref( bFunc );
    }
    // set the elementary variables
    Abc_NtkForEachCi( pNtk, pObj, i )
        if ( Abc_ObjFanoutNum(pObj) > 0 )
        {
            bFunc = fReverse ? dd->vars[Abc_NtkCiNum(pNtk) - 1 - i] : dd->vars[i];
            Abc_ObjSetGlobalBdd( pObj, bFunc );  Cudd_Ref( bFunc );
        }

    // collect the global functions of the COs
    Counter = 0;
    // construct the BDDs
    pProgress = Extra_ProgressBarStart( stdout, Abc_NtkNodeNum(pNtk) );
    Abc_NtkForEachCo( pNtk, pObj, i )
    {
        bFunc = Abc_NodeGlobalBdds_rec( dd, Abc_ObjFanin0(pObj), nBddSizeMax, fDropInternal, pProgress, &Counter, fVerbose );
        if ( bFunc == NULL )
        {
            if ( fVerbose )
            printf( "Constructing global BDDs is aborted.\n" );
            Abc_NtkFreeGlobalBdds( pNtk, 0 );
            Cudd_Quit( dd ); 

            // reset references
            Abc_NtkForEachObj( pNtk, pObj, i )
                if ( !Abc_ObjIsBox(pObj) && !Abc_ObjIsBi(pObj) )
                    pObj->vFanouts.nSize = 0;
            Abc_NtkForEachObj( pNtk, pObj, i )
                if ( !Abc_ObjIsBox(pObj) && !Abc_ObjIsBo(pObj) )
                    Abc_ObjForEachFanin( pObj, pFanin, k )
                        pFanin->vFanouts.nSize++;
            return NULL;
        }
        bFunc = Cudd_NotCond( bFunc, (int)Abc_ObjFaninC0(pObj) );  Cudd_Ref( bFunc ); 
        Abc_ObjSetGlobalBdd( pObj, bFunc );
    }
    Extra_ProgressBarStop( pProgress );

/*
    // derefence the intermediate BDDs
    Abc_NtkForEachNode( pNtk, pObj, i )
        if ( pObj->pCopy ) 
        {
            Cudd_RecursiveDeref( dd, (DdNode *)pObj->pCopy );
            pObj->pCopy = NULL;
        }
*/
/*
    // make sure all nodes are derefed
    Abc_NtkForEachObj( pNtk, pObj, i )
    {
        if ( pObj->pCopy != NULL )
            printf( "Abc_NtkBuildGlobalBdds() error: Node %d has BDD assigned\n", pObj->Id );
        if ( pObj->vFanouts.nSize > 0 )
            printf( "Abc_NtkBuildGlobalBdds() error: Node %d has refs assigned\n", pObj->Id );
    }
*/
    // reset references
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( !Abc_ObjIsBox(pObj) && !Abc_ObjIsBi(pObj) )
            pObj->vFanouts.nSize = 0;
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( !Abc_ObjIsBox(pObj) && !Abc_ObjIsBo(pObj) )
            Abc_ObjForEachFanin( pObj, pFanin, k )
                pFanin->vFanouts.nSize++;

    // reorder one more time
    if ( fReorder )
    {
        Cudd_ReduceHeap( dd, CUDD_REORDER_SYMM_SIFT, 1 );
        Cudd_AutodynDisable( dd );
    }
//    Cudd_PrintInfo( dd, stdout );
    return dd;
}

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

  Synopsis    [Derives the global BDD for one AIG node.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
DdNode * Abc_NodeGlobalBdds_rec( DdManager * dd, Abc_Obj_t * pNode, int nBddSizeMax, int fDropInternal, ProgressBar * pProgress, int * pCounter, int fVerbose )
{
    DdNode * bFunc, * bFunc0, * bFunc1, * bFuncC;
    int fDetectMuxes = 0;
    assert( !Abc_ObjIsComplement(pNode) );
    if ( Cudd_ReadKeys(dd)-Cudd_ReadDead(dd) > (unsigned)nBddSizeMax )
    {
        Extra_ProgressBarStop( pProgress );
        if ( fVerbose )
        printf( "The number of live nodes reached %d.\n", nBddSizeMax );
        fflush( stdout );
        return NULL;
    }
    // if the result is available return
    if ( Abc_ObjGlobalBdd(pNode) == NULL )
    {
        Abc_Obj_t * pNodeC, * pNode0, * pNode1;
        pNode0 = Abc_ObjFanin0(pNode);
        pNode1 = Abc_ObjFanin1(pNode);
        // check for the special case when it is MUX/EXOR
        if ( fDetectMuxes && 
             Abc_ObjGlobalBdd(pNode0) == NULL && Abc_ObjGlobalBdd(pNode1) == NULL &&
             Abc_ObjIsNode(pNode0) && Abc_ObjFanoutNum(pNode0) == 1 && 
             Abc_ObjIsNode(pNode1) && Abc_ObjFanoutNum(pNode1) == 1 && 
             Abc_NodeIsMuxType(pNode) )
        {
            // deref the fanins
            pNode0->vFanouts.nSize--;
            pNode1->vFanouts.nSize--;
            // recognize the MUX
            pNodeC = Abc_NodeRecognizeMux( pNode, &pNode1, &pNode0 );
            assert( Abc_ObjFanoutNum(pNodeC) > 1 );
            // dereference the control once (the second time it will be derefed when BDDs are computed)
            pNodeC->vFanouts.nSize--;

            // compute the result for all branches
            bFuncC = Abc_NodeGlobalBdds_rec( dd, pNodeC, nBddSizeMax, fDropInternal, pProgress, pCounter, fVerbose ); 
            if ( bFuncC == NULL )
                return NULL;
            Cudd_Ref( bFuncC );
            bFunc0 = Abc_NodeGlobalBdds_rec( dd, Abc_ObjRegular(pNode0), nBddSizeMax, fDropInternal, pProgress, pCounter, fVerbose ); 
            if ( bFunc0 == NULL )
                return NULL;
            Cudd_Ref( bFunc0 );
            bFunc1 = Abc_NodeGlobalBdds_rec( dd, Abc_ObjRegular(pNode1), nBddSizeMax, fDropInternal, pProgress, pCounter, fVerbose ); 
            if ( bFunc1 == NULL )
                return NULL;
            Cudd_Ref( bFunc1 );

            // complement the branch BDDs
            bFunc0 = Cudd_NotCond( bFunc0, (int)Abc_ObjIsComplement(pNode0) );
            bFunc1 = Cudd_NotCond( bFunc1, (int)Abc_ObjIsComplement(pNode1) );
            // get the final result
            bFunc = Cudd_bddIte( dd, bFuncC, bFunc1, bFunc0 );   Cudd_Ref( bFunc );
            Cudd_RecursiveDeref( dd, bFunc0 );
            Cudd_RecursiveDeref( dd, bFunc1 );
            Cudd_RecursiveDeref( dd, bFuncC );
            // add the number of used nodes
            (*pCounter) += 3;
        }
        else
        {
            // compute the result for both branches
            bFunc0 = Abc_NodeGlobalBdds_rec( dd, Abc_ObjFanin(pNode,0), nBddSizeMax, fDropInternal, pProgress, pCounter, fVerbose ); 
            if ( bFunc0 == NULL )
                return NULL;
            Cudd_Ref( bFunc0 );
            bFunc1 = Abc_NodeGlobalBdds_rec( dd, Abc_ObjFanin(pNode,1), nBddSizeMax, fDropInternal, pProgress, pCounter, fVerbose ); 
            if ( bFunc1 == NULL )
                return NULL;
            Cudd_Ref( bFunc1 );
            bFunc0 = Cudd_NotCond( bFunc0, (int)Abc_ObjFaninC0(pNode) );
            bFunc1 = Cudd_NotCond( bFunc1, (int)Abc_ObjFaninC1(pNode) );
            // get the final result
            bFunc = Cudd_bddAndLimit( dd, bFunc0, bFunc1, nBddSizeMax );
            if ( bFunc == NULL )
                return NULL;
            Cudd_Ref( bFunc );
            Cudd_RecursiveDeref( dd, bFunc0 );
            Cudd_RecursiveDeref( dd, bFunc1 );
            // add the number of used nodes
            (*pCounter)++;
        }
        // set the result
        assert( Abc_ObjGlobalBdd(pNode) == NULL );
        Abc_ObjSetGlobalBdd( pNode, bFunc );
        // increment the progress bar
        if ( pProgress )
            Extra_ProgressBarUpdate( pProgress, *pCounter, NULL );
    }
    // prepare the return value
    bFunc = (DdNode *)Abc_ObjGlobalBdd(pNode);
    // dereference BDD at the node
    if ( --pNode->vFanouts.nSize == 0 && fDropInternal )
    {
        Cudd_Deref( bFunc );
        Abc_ObjSetGlobalBdd( pNode, NULL );
    }
    return bFunc;
}

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

  Synopsis    [Frees the global BDDs of the network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Abc_NtkFreeGlobalBdds( Abc_Ntk_t * pNtk, int fFreeMan ) 
{ 
    return Abc_NtkAttrFree( pNtk, VEC_ATTR_GLOBAL_BDD, fFreeMan ); 
}

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

  Synopsis    [Returns the shared size of global BDDs of the COs.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_NtkSizeOfGlobalBdds( Abc_Ntk_t * pNtk ) 
{
    Vec_Ptr_t * vFuncsGlob;
    Abc_Obj_t * pObj;
    int RetValue, i;
    // complement the global functions
    vFuncsGlob = Vec_PtrAlloc( Abc_NtkCoNum(pNtk) );
    Abc_NtkForEachCo( pNtk, pObj, i )
        Vec_PtrPush( vFuncsGlob, Abc_ObjGlobalBdd(pObj) );
    RetValue = Cudd_SharingSize( (DdNode **)Vec_PtrArray(vFuncsGlob), Vec_PtrSize(vFuncsGlob) );
    Vec_PtrFree( vFuncsGlob );
    return RetValue;
}

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

  Synopsis    [Computes the BDD of the logic cone of the node.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
double Abc_NtkSpacePercentage( Abc_Obj_t * pNode )
{
    /*
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pObj, * pNodeR;
    DdManager * dd;
    DdNode * bFunc;
    double Result;
    int i;
    pNodeR = Abc_ObjRegular(pNode);
    assert( Abc_NtkIsStrash(pNodeR->pNtk) );
    Abc_NtkCleanCopy( pNodeR->pNtk );
    // get the CIs in the support of the node
    vNodes = Abc_NtkNodeSupport( pNodeR->pNtk, &pNodeR, 1 );
    // start the manager
    dd = Cudd_Init( Vec_PtrSize(vNodes), 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
    Cudd_AutodynEnable( dd, CUDD_REORDER_SYMM_SIFT );
    // assign elementary BDDs for the CIs
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
        pObj->pCopy = (Abc_Obj_t *)dd->vars[i];
    // build the BDD of the cone
    bFunc = Abc_NodeGlobalBdds_rec( dd, pNodeR, 10000000, 1, NULL, NULL, 1 );  Cudd_Ref( bFunc );
    bFunc = Cudd_NotCond( bFunc, pNode != pNodeR );
    // count minterms
    Result = Cudd_CountMinterm( dd, bFunc, dd->size );
    // get the percentagle
    Result *= 100.0;
    for ( i = 0; i < dd->size; i++ )
        Result /= 2;
    // clean up
    Cudd_Quit( dd );
    Vec_PtrFree( vNodes );
    return Result;
    */
    return 0.0;
}




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

  Synopsis    [Experiment with BDD-based representation of implications.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkBddImplicationTest()
{
    DdManager * dd;
    DdNode * bImp, * bSum, * bTemp;
    int nVars = 200;
    int nImps = 200;
    int i;
    abctime clk;
clk = Abc_Clock();
    dd = Cudd_Init( nVars, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
    Cudd_AutodynEnable( dd, CUDD_REORDER_SIFT );
    bSum = b0;   Cudd_Ref( bSum );
    for ( i = 0; i < nImps; i++ )
    {
        printf( "." );
        bImp = Cudd_bddAnd( dd, dd->vars[rand()%nVars], dd->vars[rand()%nVars] );  Cudd_Ref( bImp );
        bSum = Cudd_bddOr( dd, bTemp = bSum, bImp );     Cudd_Ref( bSum );
        Cudd_RecursiveDeref( dd, bTemp );
        Cudd_RecursiveDeref( dd, bImp );
    }
    printf( "The BDD before = %d.\n", Cudd_DagSize(bSum) );
    Cudd_ReduceHeap( dd, CUDD_REORDER_SIFT, 1 );
    printf( "The BDD after  = %d.\n", Cudd_DagSize(bSum) );
ABC_PRT( "Time", Abc_Clock() - clk );
    Cudd_RecursiveDeref( dd, bSum );
    Cudd_Quit( dd );
}

#else

double Abc_NtkSpacePercentage( Abc_Obj_t * pNode ) { return 0.0; }
Abc_Ntk_t * Abc_NtkBddToMuxes( Abc_Ntk_t * pNtk ) { return NULL; }


#endif

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


ABC_NAMESPACE_IMPL_END