summaryrefslogtreecommitdiffstats
path: root/src/proof/dch/dchChoice.c
blob: 783202e2b9d7c259b5639ac4c17ac8288abb7434 (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
/**CFile****************************************************************

  FileName    [dchChoice.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Choice computation for tech-mapping.]

  Synopsis    [Contrustion of choices.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 29, 2008.]

  Revision    [$Id: dchChoice.c,v 1.00 2008/07/29 00:00:00 alanmi Exp $]

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

#include "dchInt.h"

ABC_NAMESPACE_IMPL_START


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

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

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

  Synopsis    [Counts support nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dch_ObjCountSupp_rec( Aig_Man_t * p, Aig_Obj_t * pObj )
{
    int Count;
    if ( Aig_ObjIsTravIdCurrent( p, pObj ) )
        return 0;
    Aig_ObjSetTravIdCurrent( p, pObj );
    if ( Aig_ObjIsCi(pObj) )
        return 1;
    assert( Aig_ObjIsNode(pObj) );
    Count  = Dch_ObjCountSupp_rec( p, Aig_ObjFanin0(pObj) );
    Count += Dch_ObjCountSupp_rec( p, Aig_ObjFanin1(pObj) );
    return Count;
}
int Dch_ObjCountSupp( Aig_Man_t * p, Aig_Obj_t * pObj )
{
    Aig_ManIncrementTravId( p );
    return Dch_ObjCountSupp_rec( p, pObj );
}

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

  Synopsis    [Counts the number of representatives.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dch_DeriveChoiceCountReprs( Aig_Man_t * pAig )
{
    Aig_Obj_t * pObj, * pRepr;
    int i, nReprs = 0;
    Aig_ManForEachObj( pAig, pObj, i )
    {
        pRepr = Aig_ObjRepr( pAig, pObj );
        if ( pRepr == NULL )
            continue;
        assert( pRepr->Id < pObj->Id );
        nReprs++;
    }
    return nReprs;
}
int Dch_DeriveChoiceCountEquivs( Aig_Man_t * pAig )
{
    Aig_Obj_t * pObj, * pEquiv;
    int i, nEquivs = 0;
    Aig_ManForEachObj( pAig, pObj, i )
    {
        pEquiv = Aig_ObjEquiv( pAig, pObj );
        if ( pEquiv == NULL )
            continue;
        assert( pEquiv->Id > pObj->Id );
        nEquivs++;
    }
    return nEquivs;
}

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

  Synopsis    [Marks the TFI of the node.]

  Description [Returns 1 if there is a CI not marked with previous ID.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dch_ObjMarkTfi_rec( Aig_Man_t * p, Aig_Obj_t * pObj )
{
    int RetValue;
    if ( pObj == NULL )
        return 0;
    if ( Aig_ObjIsTravIdCurrent( p, pObj ) )
        return 0;
    if ( Aig_ObjIsCi(pObj) )
    {
        RetValue = !Aig_ObjIsTravIdPrevious( p, pObj );
        Aig_ObjSetTravIdCurrent( p, pObj );
        return RetValue;
    }
    assert( Aig_ObjIsNode(pObj) );
    Aig_ObjSetTravIdCurrent( p, pObj );
    RetValue  = Dch_ObjMarkTfi_rec( p, Aig_ObjFanin0(pObj) );
    RetValue += Dch_ObjMarkTfi_rec( p, Aig_ObjFanin1(pObj) );
//    RetValue += Dch_ObjMarkTfi_rec( p, Aig_ObjEquiv(p, pObj) );
    return (RetValue > 0);
}
int Dch_ObjCheckSuppRed( Aig_Man_t * p, Aig_Obj_t * pObj, Aig_Obj_t * pRepr )
{
    // mark support of the representative node (pRepr)
    Aig_ManIncrementTravId( p );
    Dch_ObjMarkTfi_rec( p, pRepr );
    // detect if the new node (pObj) depends on additional variables
    Aig_ManIncrementTravId( p );
    if ( Dch_ObjMarkTfi_rec( p, pObj ) )
        return 1;//, printf( "1" );
    // detect if the representative node (pRepr) depends on additional variables
    Aig_ManIncrementTravId( p );
    if ( Dch_ObjMarkTfi_rec( p, pRepr ) )
        return 1;//, printf( "2" );
    // skip the choice if this is what is happening
    return 0;
}

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

  Synopsis    [Make sure reprsentative nodes do not have representatives.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Aig_ManCheckReprs( Aig_Man_t * p )
{
    int fPrintConst = 0;
    Aig_Obj_t * pObj;
    int i, fProb = 0;
    int Class0 = 0, ClassCi = 0;
    Aig_ManForEachObj( p, pObj, i )
    {
        if ( Aig_ObjRepr(p, pObj) == NULL )
            continue;
        if ( !Aig_ObjIsNode(pObj) )
            printf( "Obj %d is not an AND but it has a repr %d.\n", i, Aig_ObjId(Aig_ObjRepr(p, pObj)) ), fProb = 1;
        else if ( Aig_ObjRepr(p, Aig_ObjRepr(p, pObj)) )
            printf( "Obj %d has repr %d with a repr %d.\n", i, Aig_ObjId(Aig_ObjRepr(p, pObj)), Aig_ObjId(Aig_ObjRepr(p, Aig_ObjRepr(p, pObj))) ), fProb = 1;
    }
    if ( !fProb )
        printf( "Representive verification successful.\n" );
    else
        printf( "Representive verification FAILED.\n" );
    if ( !fPrintConst )
        return;
    // count how many representatives are const0 or a CI
    Aig_ManForEachObj( p, pObj, i )
    {
        if ( Aig_ObjRepr(p, pObj) == Aig_ManConst1(p) )
            Class0++;
        if ( Aig_ObjRepr(p, pObj) && Aig_ObjIsCi(Aig_ObjRepr(p, pObj)) )
            ClassCi++;
    }
    printf( "Const0 nodes = %d.  ConstCI nodes = %d.\n", Class0, ClassCi );
}

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

  Synopsis    [Verify correctness of choices.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dch_CheckChoices( Aig_Man_t * p, int fSkipRedSupps )
{
    Aig_Obj_t * pObj;
    int i, fProb = 0;
    Aig_ManCleanMarkA( p );
    Aig_ManForEachNode( p, pObj, i )
    {
        if ( p->pEquivs[i] != NULL )
        {
            if ( pObj->fMarkA == 1 )
                printf( "node %d participates in more than one choice class\n", i ), fProb = 1;
            pObj->fMarkA = 1;
            // check redundancy
            if ( fSkipRedSupps && Dch_ObjCheckSuppRed( p, pObj, p->pEquivs[i]) )
                printf( "node %d and repr %d have diff supports\n", pObj->Id, p->pEquivs[i]->Id );
            // consider the next one
            pObj = p->pEquivs[i];
            if ( p->pEquivs[Aig_ObjId(pObj)] == NULL )
            {
                if ( pObj->fMarkA == 1 )
                    printf( "repr %d has final node %d participates in more than one choice class\n", i, pObj->Id ), fProb = 1;
                pObj->fMarkA = 1;
            }
            // consider the non-head ones
            if ( pObj->nRefs > 0 )
                printf( "node %d belonging to choice has fanout %d\n", pObj->Id, pObj->nRefs );
        }
        if ( p->pReprs && p->pReprs[i] != NULL )
        {
            if ( pObj->nRefs > 0 )
                printf( "node %d has representative %d and fanout count %d\n", pObj->Id, p->pReprs[i]->Id, pObj->nRefs ), fProb = 1;
        }
    }
    Aig_ManCleanMarkA( p );
    if ( !fProb )
        printf( "Verification of choice AIG succeeded.\n" );
    else
        printf( "Verification of choice AIG FAILED.\n" );
}

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

  Synopsis    [Checks for combinational loops in the AIG.]

  Description [Returns 1 if combinational loop is detected.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Aig_ManCheckAcyclic_rec( Aig_Man_t * p, Aig_Obj_t * pNode, int fVerbose )
{
    Aig_Obj_t * pFanin;
    int fAcyclic;
    if ( Aig_ObjIsCi(pNode) || Aig_ObjIsConst1(pNode) )
        return 1;
    assert( Aig_ObjIsNode(pNode) );
    // make sure the node is not visited
    assert( !Aig_ObjIsTravIdPrevious(p, pNode) );
    // check if the node is part of the combinational loop
    if ( Aig_ObjIsTravIdCurrent(p, pNode) )
    {
        if ( fVerbose )
            Abc_Print( 1, "Network \"%s\" contains combinational loop!\n", p->pSpec? p->pSpec : NULL );
        if ( fVerbose )
        Abc_Print( 1, "Node \"%d\" is encountered twice on the following path to the COs:\n", Aig_ObjId(pNode) );
        return 0;
    }
    // mark this node as a node on the current path
    Aig_ObjSetTravIdCurrent( p, pNode );

    // visit the transitive fanin
    pFanin = Aig_ObjFanin0(pNode);
    // check if the fanin is visited
    if ( !Aig_ObjIsTravIdPrevious(p, pFanin) ) 
    {
        // traverse the fanin's cone searching for the loop
        if ( !(fAcyclic = Aig_ManCheckAcyclic_rec(p, pFanin, fVerbose)) )
        {
            // return as soon as the loop is detected
            if ( fVerbose )
            Abc_Print( 1, " %d ->", Aig_ObjId(pFanin) );
            return 0;
        }
    }

    // visit the transitive fanin
    pFanin = Aig_ObjFanin1(pNode);
    // check if the fanin is visited
    if ( !Aig_ObjIsTravIdPrevious(p, pFanin) ) 
    {
        // traverse the fanin's cone searching for the loop
        if ( !(fAcyclic = Aig_ManCheckAcyclic_rec(p, pFanin, fVerbose)) )
        {
            // return as soon as the loop is detected
            if ( fVerbose )
            Abc_Print( 1, " %d ->", Aig_ObjId(pFanin) );
            return 0;
        }
    }

    // visit choices
    if ( Aig_ObjRepr(p, pNode) == NULL && Aig_ObjEquiv(p, pNode) != NULL )
    {
        for ( pFanin = Aig_ObjEquiv(p, pNode); pFanin; pFanin = Aig_ObjEquiv(p, pFanin) )
        {
            // check if the fanin is visited
            if ( Aig_ObjIsTravIdPrevious(p, pFanin) ) 
                continue;
            // traverse the fanin's cone searching for the loop
            if ( (fAcyclic = Aig_ManCheckAcyclic_rec(p, pFanin, fVerbose)) )
                continue;
            // return as soon as the loop is detected
            if ( fVerbose )
            Abc_Print( 1, " %d", Aig_ObjId(pFanin) );
            if ( fVerbose )
            Abc_Print( 1, " (choice of %d) -> ", Aig_ObjId(pNode) );
            return 0;
        }
    }
    // mark this node as a visited node
    Aig_ObjSetTravIdPrevious( p, pNode );
    return 1;
}
int Aig_ManCheckAcyclic( Aig_Man_t * p, int fVerbose )
{
    Aig_Obj_t * pNode;
    int fAcyclic;
    int i;
    // set the traversal ID for this DFS ordering
    Aig_ManIncrementTravId( p );   
    Aig_ManIncrementTravId( p );   
    // pNode->TravId == pNet->nTravIds      means "pNode is on the path"
    // pNode->TravId == pNet->nTravIds - 1  means "pNode is visited but is not on the path"
    // pNode->TravId <  pNet->nTravIds - 1  means "pNode is not visited"
    // traverse the network to detect cycles
    fAcyclic = 1;
    Aig_ManForEachCo( p, pNode, i )
    {
        pNode = Aig_ObjFanin0(pNode);
        if ( Aig_ObjIsTravIdPrevious(p, pNode) )
            continue;
        // traverse the output logic cone
        if ( (fAcyclic = Aig_ManCheckAcyclic_rec(p, pNode, fVerbose)) )
            continue;
        // stop as soon as the first loop is detected
        if ( fVerbose )
        Abc_Print( 1, " CO %d\n", i );
        break;
    }
    return fAcyclic;
}


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

  Synopsis    [Returns 1 if the choice node of pRepr is in the TFI of pObj.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Dch_ObjCheckTfi_rec( Aig_Man_t * p, Aig_Obj_t * pObj )
{
    // check the trivial cases
    if ( pObj == NULL )
        return 0;
    if ( Aig_ObjIsCi(pObj) )
        return 0;
    if ( pObj->fMarkA )
        return 1;
    // skip the visited node
    if ( Aig_ObjIsTravIdCurrent( p, pObj ) )
        return 0;
    Aig_ObjSetTravIdCurrent( p, pObj );
    // check the children
    if ( Dch_ObjCheckTfi_rec( p, Aig_ObjFanin0(pObj) ) )
        return 1;
    if ( Dch_ObjCheckTfi_rec( p, Aig_ObjFanin1(pObj) ) )
        return 1;
    // check equivalent nodes
    return Dch_ObjCheckTfi_rec( p, Aig_ObjEquiv(p, pObj) );
}
int Dch_ObjCheckTfi( Aig_Man_t * p, Aig_Obj_t * pObj, Aig_Obj_t * pRepr )
{
    Aig_Obj_t * pTemp;
    int RetValue;
    assert( !Aig_IsComplement(pObj) );
    assert( !Aig_IsComplement(pRepr) );
    // mark nodes of the choice node
    for ( pTemp = pRepr; pTemp; pTemp = Aig_ObjEquiv(p, pTemp) )
        pTemp->fMarkA = 1;
    // traverse the new node
    Aig_ManIncrementTravId( p );
    RetValue = Dch_ObjCheckTfi_rec( p, pObj );
    // unmark nodes of the choice node
    for ( pTemp = pRepr; pTemp; pTemp = Aig_ObjEquiv(p, pTemp) )
        pTemp->fMarkA = 0;
    return RetValue;
}

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

  Synopsis    [Returns representatives of fanin in approapriate polarity.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline Aig_Obj_t * Aig_ObjGetRepr( Aig_Man_t * p, Aig_Obj_t * pObj )
{
    Aig_Obj_t * pRepr;
    if ( (pRepr = Aig_ObjRepr(p, Aig_Regular(pObj))) )
        return Aig_NotCond( pRepr, Aig_Regular(pObj)->fPhase ^ pRepr->fPhase ^ Aig_IsComplement(pObj) );
    return pObj;
}
static inline Aig_Obj_t * Aig_ObjChild0CopyRepr( Aig_Man_t * p, Aig_Obj_t * pObj ) { return Aig_ObjGetRepr( p, Aig_ObjChild0Copy(pObj) ); }
static inline Aig_Obj_t * Aig_ObjChild1CopyRepr( Aig_Man_t * p, Aig_Obj_t * pObj ) { return Aig_ObjGetRepr( p, Aig_ObjChild1Copy(pObj) ); }

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

  Synopsis    [Derives the AIG with choices from representatives.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Dch_DeriveChoiceAigNode( Aig_Man_t * pAigNew, Aig_Man_t * pAigOld, Aig_Obj_t * pObj, int fSkipRedSupps )
{
    Aig_Obj_t * pRepr, * pObjNew, * pReprNew;
    assert( !Aig_IsComplement(pObj) );
    // get the representative
    pRepr = Aig_ObjRepr( pAigOld, pObj );
    if ( pRepr != NULL && (Aig_ObjIsConst1(pRepr) || Aig_ObjIsCi(pRepr)) )
    {
        assert( pRepr->pData != NULL );
        pObj->pData = Aig_NotCond( (Aig_Obj_t *)pRepr->pData, pObj->fPhase ^ pRepr->fPhase );
        return;
    }
    // get the new node
    pObjNew = Aig_And( pAigNew, 
        Aig_ObjChild0CopyRepr(pAigNew, pObj), 
        Aig_ObjChild1CopyRepr(pAigNew, pObj) );
    pObjNew = Aig_ObjGetRepr( pAigNew, pObjNew );
    assert( Aig_ObjRepr( pAigNew, pObjNew ) == NULL );
    // assign the copy
    assert( pObj->pData == NULL );
    pObj->pData = pObjNew;
    // skip those without reprs
    if ( pRepr == NULL )
        return;
    assert( pRepr->Id < pObj->Id );
    assert( Aig_ObjIsNode(pRepr) );
    // get the corresponding new nodes
    pObjNew  = Aig_Regular((Aig_Obj_t *)pObj->pData);
    pReprNew = Aig_Regular((Aig_Obj_t *)pRepr->pData);
    // skip earlier nodes
    if ( pReprNew->Id >= pObjNew->Id )
        return;
    assert( pReprNew->Id < pObjNew->Id );
    // set the representatives
    Aig_ObjSetRepr( pAigNew, pObjNew, pReprNew );
    // skip used nodes
    if ( pObjNew->nRefs > 0 )
        return;
    assert( pObjNew->nRefs == 0 );
    // skip choices that can lead to combo loops
    if ( Dch_ObjCheckTfi( pAigNew, pObjNew, pReprNew ) )
        return;
    // don't add choice if structural support of pObjNew and pReprNew differ
    if ( fSkipRedSupps && Dch_ObjCheckSuppRed(pAigNew, pObjNew, pReprNew) )
        return;
    // add choice to the end of the list
    while ( pAigNew->pEquivs[pReprNew->Id] != NULL )
        pReprNew = pAigNew->pEquivs[pReprNew->Id];
    assert( pAigNew->pEquivs[pReprNew->Id] == NULL );
    pAigNew->pEquivs[pReprNew->Id] = pObjNew;
}
Aig_Man_t * Dch_DeriveChoiceAigInt( Aig_Man_t * pAig, int fSkipRedSupps )
{
    Aig_Man_t * pChoices;
    Aig_Obj_t * pObj;
    int i;
    // start recording equivalences
    pChoices = Aig_ManStart( Aig_ManObjNumMax(pAig) );
    pChoices->pEquivs = ABC_CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(pAig) );
    pChoices->pReprs  = ABC_CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(pAig) );
    // map constants and PIs
    Aig_ManCleanData( pAig );
    Aig_ManConst1(pAig)->pData = Aig_ManConst1(pChoices);
    Aig_ManForEachCi( pAig, pObj, i )
        pObj->pData = Aig_ObjCreateCi( pChoices );
    // construct choices for the internal nodes
    assert( pAig->pReprs != NULL );
    Aig_ManForEachNode( pAig, pObj, i ) 
        Dch_DeriveChoiceAigNode( pChoices, pAig, pObj, fSkipRedSupps );
    Aig_ManForEachCo( pAig, pObj, i )
        Aig_ObjCreateCo( pChoices, Aig_ObjChild0CopyRepr(pChoices, pObj) );
    Aig_ManSetRegNum( pChoices, Aig_ManRegNum(pAig) );
    return pChoices;
}
Aig_Man_t * Dch_DeriveChoiceAig( Aig_Man_t * pAig, int fSkipRedSupps )
{
    int fCheck = 0;
    Aig_Man_t * pChoices, * pTemp;
    // verify
    if ( fCheck )
        Aig_ManCheckReprs( pAig ); 
    // compute choices
    pChoices = Dch_DeriveChoiceAigInt( pAig, fSkipRedSupps );
    ABC_FREE( pChoices->pReprs );
    // verify
    if ( fCheck )
        Dch_CheckChoices( pChoices, fSkipRedSupps ); 
    // find correct topo order with choices
    pChoices = Aig_ManDupDfs( pTemp = pChoices );
    Aig_ManStop( pTemp );
    // verify
    if ( fCheck )
        Dch_CheckChoices( pChoices, fSkipRedSupps ); 
    return pChoices;
}

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


ABC_NAMESPACE_IMPL_END