summaryrefslogtreecommitdiffstats
path: root/src/opt/dar/darBalance.c
blob: f51a7852ebfeac3bb0d69a29a89e1d94767fa2f2 (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
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
/**CFile****************************************************************

  FileName    [darBalance.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [DAG-aware AIG rewriting.]

  Synopsis    [Algebraic AIG balancing.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - April 28, 2007.]

  Revision    [$Id: darBalance.c,v 1.00 2007/04/28 00:00:00 alanmi Exp $]

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

#include "darInt.h"
#include "misc/tim/tim.h"

ABC_NAMESPACE_IMPL_START


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

//#define USE_LUTSIZE_BALANCE

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

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

  Synopsis    [Uniqifies the node.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dar_ObjCompareLits( Aig_Obj_t ** pp1, Aig_Obj_t ** pp2 )
{
    int Diff = Aig_ObjToLit(*pp1) - Aig_ObjToLit(*pp2);
    if ( Diff < 0 )
        return -1;
    if ( Diff > 0 ) 
        return 1;
    return 0; 
}
void Dar_BalanceUniqify( Aig_Obj_t * pObj, Vec_Ptr_t * vNodes, int fExor )
{
    Aig_Obj_t * pTemp, * pTempNext;
    int i, k;
    // sort the nodes by their literal
    Vec_PtrSort( vNodes, (int (*)())Dar_ObjCompareLits );
    // remove duplicates
    k = 0;
    Vec_PtrForEachEntry( Aig_Obj_t *, vNodes, pTemp, i )
    {
        if ( i + 1 == Vec_PtrSize(vNodes) )
        {
            Vec_PtrWriteEntry( vNodes, k++, pTemp );
            break;
        }
        pTempNext = (Aig_Obj_t *)Vec_PtrEntry( vNodes, i+1 );
        if ( !fExor && pTemp == Aig_Not(pTempNext) ) // pos_lit & neg_lit = 0
        {
            Vec_PtrClear( vNodes );
            return;
        }
        if ( pTemp != pTempNext )  // save if different
            Vec_PtrWriteEntry( vNodes, k++, pTemp );
        else if ( fExor ) // in case of XOR, remove identical
            i++;
    }
    Vec_PtrShrink( vNodes, k );
    if ( Vec_PtrSize(vNodes) < 2 )
        return;
    // check that there is no duplicates
    pTemp = (Aig_Obj_t *)Vec_PtrEntry( vNodes, 0 );
    Vec_PtrForEachEntryStart( Aig_Obj_t *, vNodes, pTempNext, i, 1 )
    {
        assert( pTemp != pTempNext );
        pTemp = pTempNext;
    }
}

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

  Synopsis    [Collects the nodes of the supergate.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dar_BalanceCone_rec( Aig_Obj_t * pRoot, Aig_Obj_t * pObj, Vec_Ptr_t * vSuper )
{
    if ( pObj != pRoot && (Aig_IsComplement(pObj) || Aig_ObjType(pObj) != Aig_ObjType(pRoot) || Aig_ObjRefs(pObj) > 1 || Vec_PtrSize(vSuper) > 10000) )
        Vec_PtrPush( vSuper, pObj );
    else
    {
        assert( !Aig_IsComplement(pObj) );
        assert( Aig_ObjIsNode(pObj) );
        // go through the branches
        Dar_BalanceCone_rec( pRoot, Aig_ObjReal_rec( Aig_ObjChild0(pObj) ), vSuper );
        Dar_BalanceCone_rec( pRoot, Aig_ObjReal_rec( Aig_ObjChild1(pObj) ), vSuper );
    }
}
Vec_Ptr_t * Dar_BalanceCone( Aig_Obj_t * pObj, Vec_Vec_t * vStore, int Level )
{
    Vec_Ptr_t * vNodes;
    assert( !Aig_IsComplement(pObj) );
    assert( Aig_ObjIsNode(pObj) );
    // extend the storage
    if ( Vec_VecSize( vStore ) <= Level )
        Vec_VecPush( vStore, Level, 0 );
    // get the temporary array of nodes
    vNodes = Vec_VecEntry( vStore, Level );
    Vec_PtrClear( vNodes );
    // collect the nodes in the implication supergate
    Dar_BalanceCone_rec( pObj, pObj, vNodes );
    // remove duplicates
    Dar_BalanceUniqify( pObj, vNodes, Aig_ObjIsExor(pObj) );
    return vNodes;
}


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

  Synopsis    [Collects the nodes of the supergate.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
/*
int Dar_BalanceCone_rec( Aig_Obj_t * pRoot, Aig_Obj_t * pObj, Vec_Ptr_t * vSuper )
{
    int RetValue1, RetValue2, i;
    // check if the node is visited
    if ( Aig_Regular(pObj)->fMarkB )
    {
        if ( Aig_ObjIsExor(pRoot) )
        {
            assert( !Aig_IsComplement(pObj) );
            // check if the node occurs in the same polarity
            Vec_PtrRemove( vSuper, pObj );
            Aig_Regular(pObj)->fMarkB = 0;
//printf( " Duplicated EXOR input!!! " );
            return 1;
        }
        else
        {
            // check if the node occurs in the same polarity
            for ( i = 0; i < vSuper->nSize; i++ )
                if ( vSuper->pArray[i] == pObj )
                    return 1;
            // check if the node is present in the opposite polarity
            for ( i = 0; i < vSuper->nSize; i++ )
                if ( vSuper->pArray[i] == Aig_Not(pObj) )
                    return -1;
        }
        assert( 0 );
        return 0;
    }
    // if the new node is complemented or a PI, another gate begins
    if ( pObj != pRoot && (Aig_IsComplement(pObj) || Aig_ObjType(pObj) != Aig_ObjType(pRoot) || Aig_ObjRefs(pObj) > 1 || Vec_PtrSize(vSuper) > 10000) )
    {
        Vec_PtrPush( vSuper, pObj );
        Aig_Regular(pObj)->fMarkB = 1;
        return 0;
    }
    assert( !Aig_IsComplement(pObj) );
    assert( Aig_ObjIsNode(pObj) );
    // go through the branches
    RetValue1 = Dar_BalanceCone_rec( pRoot, Aig_ObjReal_rec( Aig_ObjChild0(pObj) ), vSuper );
    RetValue2 = Dar_BalanceCone_rec( pRoot, Aig_ObjReal_rec( Aig_ObjChild1(pObj) ), vSuper );
    if ( RetValue1 == -1 || RetValue2 == -1 )
        return -1;
    // return 1 if at least one branch has a duplicate
    return RetValue1 || RetValue2;
}
Vec_Ptr_t * Dar_BalanceCone( Aig_Obj_t * pObj, Vec_Vec_t * vStore, int Level )
{
    Vec_Ptr_t * vNodes;
    int RetValue, i;
    assert( !Aig_IsComplement(pObj) );
    // extend the storage
    if ( Vec_VecSize( vStore ) <= Level )
        Vec_VecPush( vStore, Level, 0 );
    // get the temporary array of nodes
    vNodes = Vec_VecEntry( vStore, Level );
    Vec_PtrClear( vNodes );
    // collect the nodes in the implication supergate
    RetValue = Dar_BalanceCone_rec( pObj, pObj, vNodes );
    assert( RetValue != 0 || vNodes->nSize > 1 );
    // unmark the visited nodes
    Vec_PtrForEachEntry( Aig_Obj_t *, vNodes, pObj, i )
        Aig_Regular(pObj)->fMarkB = 0;
    // if we found the node and its complement in the same implication supergate, 
    // return empty set of nodes (meaning that we should use constant-0 node)
    if ( RetValue == -1 )
        vNodes->nSize = 0;
    return vNodes;
}
*/

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

  Synopsis    [Finds the left bound on the next candidate to be paired.]

  Description [The nodes in the array are in the decreasing order of levels. 
  The last node in the array has the smallest level. By default it would be paired 
  with the next node on the left. However, it may be possible to pair it with some
  other node on the left, in such a way that the new node is shared. This procedure
  finds the index of the left-most node, which can be paired with the last node.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dar_BalanceFindLeft( Vec_Ptr_t * vSuper )
{
    Aig_Obj_t * pObjRight, * pObjLeft;
    int Current;
    // if two or less nodes, pair with the first
    if ( Vec_PtrSize(vSuper) < 3 )
        return 0;
    // set the pointer to the one before the last
    Current = Vec_PtrSize(vSuper) - 2;
    pObjRight = (Aig_Obj_t *)Vec_PtrEntry( vSuper, Current );
    // go through the nodes to the left of this one
    for ( Current--; Current >= 0; Current-- )
    {
        // get the next node on the left
        pObjLeft = (Aig_Obj_t *)Vec_PtrEntry( vSuper, Current );
        // if the level of this node is different, quit the loop
        if ( Aig_ObjLevel(Aig_Regular(pObjLeft)) != Aig_ObjLevel(Aig_Regular(pObjRight)) )
            break;
    }
    Current++;    
    // get the node, for which the equality holds
    pObjLeft = (Aig_Obj_t *)Vec_PtrEntry( vSuper, Current );
    assert( Aig_ObjLevel(Aig_Regular(pObjLeft)) == Aig_ObjLevel(Aig_Regular(pObjRight)) );
    return Current;
}

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

  Synopsis    [Moves closer to the end the node that is best for sharing.]

  Description [If there is no node with sharing, randomly chooses one of 
  the legal nodes.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dar_BalancePermute( Aig_Man_t * p, Vec_Ptr_t * vSuper, int LeftBound, int fExor )
{
    Aig_Obj_t * pObj1, * pObj2, * pObj3, * pGhost;
    int RightBound, i;
    // get the right bound
    RightBound = Vec_PtrSize(vSuper) - 2;
    assert( LeftBound <= RightBound );
    if ( LeftBound == RightBound )
        return;
    // get the two last nodes
    pObj1 = (Aig_Obj_t *)Vec_PtrEntry( vSuper, RightBound + 1 );
    pObj2 = (Aig_Obj_t *)Vec_PtrEntry( vSuper, RightBound     );
    if ( Aig_Regular(pObj1) == p->pConst1 || Aig_Regular(pObj2) == p->pConst1 || Aig_Regular(pObj1) == Aig_Regular(pObj2) )
        return;
    // find the first node that can be shared
    for ( i = RightBound; i >= LeftBound; i-- )
    {
        pObj3 = (Aig_Obj_t *)Vec_PtrEntry( vSuper, i );
        if ( Aig_Regular(pObj3) == p->pConst1 )
        {
            Vec_PtrWriteEntry( vSuper, i,          pObj2 );
            Vec_PtrWriteEntry( vSuper, RightBound, pObj3 );
            return;
        }
        if ( Aig_Regular(pObj1) == Aig_Regular(pObj3) )
        {
            if ( pObj3 == pObj2 )
                return;
            Vec_PtrWriteEntry( vSuper, i,          pObj2 );
            Vec_PtrWriteEntry( vSuper, RightBound, pObj3 );
            return;
        }
        pGhost = Aig_ObjCreateGhost( p, pObj1, pObj3, fExor? AIG_OBJ_EXOR : AIG_OBJ_AND );
        if ( Aig_TableLookup( p, pGhost ) )
        {
            if ( pObj3 == pObj2 )
                return;
            Vec_PtrWriteEntry( vSuper, i,          pObj2 );
            Vec_PtrWriteEntry( vSuper, RightBound, pObj3 );
            return;
        }
    }
/*
    // we did not find the node to share, randomize choice
    {
        int Choice = Aig_ManRandom(0) % (RightBound - LeftBound + 1);
        pObj3 = Vec_PtrEntry( vSuper, LeftBound + Choice );
        if ( pObj3 == pObj2 )
            return;
        Vec_PtrWriteEntry( vSuper, LeftBound + Choice, pObj2 );
        Vec_PtrWriteEntry( vSuper, RightBound,         pObj3 );
    }
*/
}

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

  Synopsis    [Procedure used for sorting the nodes in decreasing order of levels.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Aig_NodeCompareLevelsDecrease( Aig_Obj_t ** pp1, Aig_Obj_t ** pp2 )
{
    int Diff = Aig_ObjLevel(Aig_Regular(*pp1)) - Aig_ObjLevel(Aig_Regular(*pp2));
    if ( Diff > 0 )
        return -1;
    if ( Diff < 0 ) 
        return 1;
    Diff = Aig_ObjId(Aig_Regular(*pp1)) - Aig_ObjId(Aig_Regular(*pp2));
    if ( Diff > 0 )
        return -1;
    if ( Diff < 0 ) 
        return 1;
    return 0; 
}

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

  Synopsis    [Inserts a new node in the order by levels.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dar_BalancePushUniqueOrderByLevel( Vec_Ptr_t * vStore, Aig_Obj_t * pObj, int fExor )
{
    Aig_Obj_t * pObj1, * pObj2;
    int i;
    if ( Vec_PtrPushUnique(vStore, pObj) )
    {
        if ( fExor )
            Vec_PtrRemove(vStore, pObj);
        return;
    }
    // find the p of the node
    for ( i = vStore->nSize-1; i > 0; i-- )
    {
        pObj1 = (Aig_Obj_t *)vStore->pArray[i  ];
        pObj2 = (Aig_Obj_t *)vStore->pArray[i-1];
        if ( Aig_ObjLevel(Aig_Regular(pObj1)) <= Aig_ObjLevel(Aig_Regular(pObj2)) )
            break;
        vStore->pArray[i  ] = pObj2;
        vStore->pArray[i-1] = pObj1;
    }
}

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

  Synopsis    [Builds implication supergate.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Obj_t * Dar_BalanceBuildSuper( Aig_Man_t * p, Vec_Ptr_t * vSuper, Aig_Type_t Type, int fUpdateLevel )
{
    Aig_Obj_t * pObj1, * pObj2;
    int LeftBound;
    assert( vSuper->nSize > 1 );
    // sort the new nodes by level in the decreasing order
    Vec_PtrSort( vSuper, (int (*)(void))Aig_NodeCompareLevelsDecrease );
    // balance the nodes
    while ( vSuper->nSize > 1 )
    {
        // find the left bound on the node to be paired
        LeftBound = (!fUpdateLevel)? 0 : Dar_BalanceFindLeft( vSuper );
        // find the node that can be shared (if no such node, randomize choice)
        Dar_BalancePermute( p, vSuper, LeftBound, Type == AIG_OBJ_EXOR );
        // pull out the last two nodes
        pObj1 = (Aig_Obj_t *)Vec_PtrPop(vSuper);
        pObj2 = (Aig_Obj_t *)Vec_PtrPop(vSuper);
        Dar_BalancePushUniqueOrderByLevel( vSuper, Aig_Oper(p, pObj1, pObj2, Type), Type == AIG_OBJ_EXOR );
    }
    return (Aig_Obj_t *)Vec_PtrEntry(vSuper, 0);
}


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

  Synopsis    [Returns affective support size.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Aig_BaseSize( Aig_Man_t * p, Aig_Obj_t * pObj, int nLutSize )
{
    int nBaseSize;
    pObj = Aig_Regular(pObj);
    if ( Aig_ObjIsConst1(pObj) )
        return 0;
    if ( Aig_ObjLevel(pObj) >= nLutSize )
        return 1;
    nBaseSize = Aig_SupportSize( p, pObj );
    if ( nBaseSize >= nLutSize )
        return 1;
    return nBaseSize;
}

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

  Synopsis    [Builds implication supergate.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Obj_t * Dar_BalanceBuildSuperTop( Aig_Man_t * p, Vec_Ptr_t * vSuper, Aig_Type_t Type, int fUpdateLevel, int nLutSize )
{
    Vec_Ptr_t * vSubset;
    Aig_Obj_t * pObj;
    int i, nBaseSizeAll, nBaseSize;
    assert( vSuper->nSize > 1 );
    // sort the new nodes by level in the decreasing order
    Vec_PtrSort( vSuper, (int (*)(void))Aig_NodeCompareLevelsDecrease );
    // add one LUT at a time
    while ( Vec_PtrSize(vSuper) > 1 )
    {
        // isolate the group of nodes with nLutSize inputs
        nBaseSizeAll = 0;
        vSubset = Vec_PtrAlloc( nLutSize );
        Vec_PtrForEachEntryReverse( Aig_Obj_t *, vSuper, pObj, i )
        {
            nBaseSize = Aig_BaseSize( p, pObj, nLutSize );
            if ( nBaseSizeAll + nBaseSize > nLutSize && Vec_PtrSize(vSubset) > 1 )
                break;
            nBaseSizeAll += nBaseSize;
            Vec_PtrPush( vSubset, pObj );
        }
        // remove them from vSuper
        Vec_PtrShrink( vSuper, Vec_PtrSize(vSuper) - Vec_PtrSize(vSubset) );
        // create the new supergate
        pObj = Dar_BalanceBuildSuper( p, vSubset, Type, fUpdateLevel );
        Vec_PtrFree( vSubset );
        // add the new output
        Dar_BalancePushUniqueOrderByLevel( vSuper, pObj, Type == AIG_OBJ_EXOR );
    }
    return (Aig_Obj_t *)Vec_PtrEntry(vSuper, 0);
}

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

  Synopsis    [Returns the new node constructed.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Obj_t * Dar_Balance_rec( Aig_Man_t * pNew, Aig_Obj_t * pObjOld, Vec_Vec_t * vStore, int Level, int fUpdateLevel )
{
    Aig_Obj_t * pObjNew;
    Vec_Ptr_t * vSuper;
    int i;
    assert( !Aig_IsComplement(pObjOld) );
    assert( !Aig_ObjIsBuf(pObjOld) );
    // return if the result is known
    if ( pObjOld->pData )
        return (Aig_Obj_t *)pObjOld->pData;
    assert( Aig_ObjIsNode(pObjOld) );
    // get the implication supergate
    vSuper = Dar_BalanceCone( pObjOld, vStore, Level );
    // check if supergate contains two nodes in the opposite polarity
    if ( vSuper->nSize == 0 )
        return (Aig_Obj_t *)(pObjOld->pData = Aig_ManConst0(pNew));
    // for each old node, derive the new well-balanced node
    for ( i = 0; i < Vec_PtrSize(vSuper); i++ )
    {
        pObjNew = Dar_Balance_rec( pNew, Aig_Regular((Aig_Obj_t *)vSuper->pArray[i]), vStore, Level + 1, fUpdateLevel );
        if ( pObjNew == NULL )
            return NULL;
        vSuper->pArray[i] = Aig_NotCond( pObjNew, Aig_IsComplement((Aig_Obj_t *)vSuper->pArray[i]) );
    }
    // check for exactly one node
    if ( vSuper->nSize == 1 )
        return (Aig_Obj_t *)Vec_PtrEntry(vSuper, 0);
    // build the supergate
#ifdef USE_LUTSIZE_BALANCE
    pObjNew = Dar_BalanceBuildSuperTop( pNew, vSuper, Aig_ObjType(pObjOld), fUpdateLevel, 6 );
#else
    pObjNew = Dar_BalanceBuildSuper( pNew, vSuper, Aig_ObjType(pObjOld), fUpdateLevel );
#endif
    if ( pNew->Time2Quit && !(Aig_Regular(pObjNew)->Id & 255) && Abc_Clock() > pNew->Time2Quit )
        return NULL;
    // make sure the balanced node is not assigned
//    assert( pObjOld->Level >= Aig_Regular(pObjNew)->Level );
    assert( pObjOld->pData == NULL );
    return (Aig_Obj_t *)(pObjOld->pData = pObjNew);
}

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

  Synopsis    [Performs algebraic balancing of the AIG.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManBalance( Aig_Man_t * p, int fUpdateLevel )
{
    Aig_Man_t * pNew;
    Aig_Obj_t * pObj, * pDriver, * pObjNew;
    Vec_Vec_t * vStore;
    int i;
    assert( Aig_ManVerifyTopoOrder(p) );
    // create the new manager 
    pNew = Aig_ManStart( Aig_ManObjNumMax(p) );
    pNew->pName = Abc_UtilStrsav( p->pName );
    pNew->pSpec = Abc_UtilStrsav( p->pSpec );
    pNew->nAsserts = p->nAsserts;
    pNew->nConstrs = p->nConstrs;
    pNew->nBarBufs = p->nBarBufs;
    pNew->Time2Quit = p->Time2Quit;
    if ( p->vFlopNums )
        pNew->vFlopNums = Vec_IntDup( p->vFlopNums );
    // map the PI nodes
    Aig_ManCleanData( p );
    Aig_ManConst1(p)->pData = Aig_ManConst1(pNew);
    vStore = Vec_VecAlloc( 50 );
    if ( p->pManTime != NULL )
    {
        float arrTime;
        Tim_ManIncrementTravId( (Tim_Man_t *)p->pManTime );
        Aig_ManSetCioIds( p );
        Aig_ManForEachObj( p, pObj, i )
        {
            if ( Aig_ObjIsNode(pObj) || Aig_ObjIsConst1(pObj) )
                continue;
            if ( Aig_ObjIsCi(pObj) )
            {
                // copy the PI
                pObjNew = Aig_ObjCreateCi(pNew); 
                pObj->pData = pObjNew;
                // set the arrival time of the new PI
                arrTime = Tim_ManGetCiArrival( (Tim_Man_t *)p->pManTime, Aig_ObjCioId(pObj) );
                pObjNew->Level = (int)arrTime;
            }
            else if ( Aig_ObjIsCo(pObj) )
            {
                // perform balancing
                pDriver = Aig_ObjReal_rec( Aig_ObjChild0(pObj) );
                pObjNew = Dar_Balance_rec( pNew, Aig_Regular(pDriver), vStore, 0, fUpdateLevel );
                if ( pObjNew == NULL )
                {
                    Vec_VecFree( vStore );
                    Aig_ManStop( pNew );
                    return NULL;
                }
                pObjNew = Aig_NotCond( pObjNew, Aig_IsComplement(pDriver) );
                // save arrival time of the output
                arrTime = (float)Aig_Regular(pObjNew)->Level;
                Tim_ManSetCoArrival( (Tim_Man_t *)p->pManTime, Aig_ObjCioId(pObj), arrTime );
                // create PO
                pObjNew = Aig_ObjCreateCo( pNew, pObjNew );
            }
            else
                assert( 0 );
        }
        Aig_ManCleanCioIds( p );
        pNew->pManTime = Tim_ManDup( (Tim_Man_t *)p->pManTime, 0 );
    }
    else
    {
        Aig_ManForEachCi( p, pObj, i )
        {
            pObjNew = Aig_ObjCreateCi(pNew); 
            pObjNew->Level = pObj->Level;
            pObj->pData = pObjNew;
        }
        if ( p->nBarBufs == 0 )
        {
            Aig_ManForEachCo( p, pObj, i )
            {
                pDriver = Aig_ObjReal_rec( Aig_ObjChild0(pObj) );
                pObjNew = Dar_Balance_rec( pNew, Aig_Regular(pDriver), vStore, 0, fUpdateLevel );
                if ( pObjNew == NULL )
                {
                    Vec_VecFree( vStore );
                    Aig_ManStop( pNew );
                    return NULL;
                }
                pObjNew = Aig_NotCond( pObjNew, Aig_IsComplement(pDriver) );
                pObjNew = Aig_ObjCreateCo( pNew, pObjNew );
            }
        }
        else
        {
            Vec_Ptr_t * vLits = Vec_PtrStart( Aig_ManCoNum(p) );
            Aig_ManForEachCo( p, pObj, i )
            {
                int k = i < p->nBarBufs ? Aig_ManCoNum(p) - p->nBarBufs + i : i - p->nBarBufs;
                pObj = Aig_ManCo( p, k );
                pDriver = Aig_ObjReal_rec( Aig_ObjChild0(pObj) );
                pObjNew = Dar_Balance_rec( pNew, Aig_Regular(pDriver), vStore, 0, fUpdateLevel );
                if ( pObjNew == NULL )
                {
                    Vec_VecFree( vStore );
                    Aig_ManStop( pNew );
                    return NULL;
                }
                pObjNew = Aig_NotCond( pObjNew, Aig_IsComplement(pDriver) );
                Vec_PtrWriteEntry( vLits, k, pObjNew );
                if ( i < p->nBarBufs )
                    Aig_ManCi(pNew, Aig_ManCiNum(p) - p->nBarBufs + i)->Level = Aig_Regular(pObjNew)->Level;
            }
            Aig_ManForEachCo( p, pObj, i )
                Aig_ObjCreateCo( pNew, (Aig_Obj_t *)Vec_PtrEntry(vLits, i) );
            Vec_PtrFree(vLits);
        }
    }
    Vec_VecFree( vStore );
    // remove dangling nodes
    Aig_ManCleanup( pNew );
    Aig_ManSetRegNum( pNew, Aig_ManRegNum(p) );
    // check the resulting AIG
    if ( !Aig_ManCheck(pNew) )
        printf( "Dar_ManBalance(): The check has failed.\n" );
    return pNew;
}

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

  Synopsis    [Reproduces script "compress2".]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Dar_ManBalanceXor( Aig_Man_t * pAig, int fExor, int fUpdateLevel, int fVerbose )
{
    Aig_Man_t * pAigXor, * pRes;
    if ( fExor )
    {
        pAigXor = Aig_ManDupExor( pAig );
        if ( fVerbose )
            Dar_BalancePrintStats( pAigXor );
        pRes = Dar_ManBalance( pAigXor, fUpdateLevel );
        Aig_ManStop( pAigXor );
    }
    else
    {
        pRes = Dar_ManBalance( pAig, fUpdateLevel );
    }
    return pRes;
}

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

  Synopsis    [Inserts a new node in the order by levels.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dar_BalancePrintStats( Aig_Man_t * p )
{
    Vec_Ptr_t * vSuper;
    Aig_Obj_t * pObj, * pTemp;
    int i, k;
    if ( Aig_ManExorNum(p) == 0 )
    {
        printf( "There is no EXOR gates.\n" );
        return;
    }
    Aig_ManForEachExor( p, pObj, i )
    {
        Aig_ObjFanin0(pObj)->fMarkA = 1;
        Aig_ObjFanin1(pObj)->fMarkA = 1;
        assert( !Aig_ObjFaninC0(pObj) );
        assert( !Aig_ObjFaninC1(pObj) );
    }
    vSuper = Vec_PtrAlloc( 1000 );
    Aig_ManForEachExor( p, pObj, i )
    {
        if ( pObj->fMarkA && pObj->nRefs == 1 )
            continue;
        Vec_PtrClear( vSuper );
        Dar_BalanceCone_rec( pObj, pObj, vSuper );
        Vec_PtrForEachEntry( Aig_Obj_t *, vSuper, pTemp, k )
            pTemp->fMarkB = 0;
        if ( Vec_PtrSize(vSuper) < 3 )
            continue;
        printf( "  %d(", Vec_PtrSize(vSuper) );
        Vec_PtrForEachEntry( Aig_Obj_t *, vSuper, pTemp, k )
            printf( " %d", pTemp->Level );
        printf( " )" );
    }
    Vec_PtrFree( vSuper );
    Aig_ManForEachObj( p, pObj, i )
        pObj->fMarkA = 0;
    printf( "\n" );
}

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


ABC_NAMESPACE_IMPL_END