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
|
/**CFile****************************************************************
FileName [abcDsd.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Network and node package.]
Synopsis [Decomposes the network using disjoint-support decomposition.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: abcDsd.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "base/abc/abc.h"
#include "misc/extra/extraBdd.h"
#include "bdd/dsd/dsd.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static Abc_Ntk_t * Abc_NtkDsdInternal( Abc_Ntk_t * pNtk, int fVerbose, int fPrint, int fShort );
static void Abc_NtkDsdConstruct( Dsd_Manager_t * pManDsd, Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew );
static Abc_Obj_t * Abc_NtkDsdConstructNode( Dsd_Manager_t * pManDsd, Dsd_Node_t * pNodeDsd, Abc_Ntk_t * pNtkNew, int * pCounters );
static Vec_Ptr_t * Abc_NtkCollectNodesForDsd( Abc_Ntk_t * pNtk );
static void Abc_NodeDecompDsdAndMux( Abc_Obj_t * pNode, Vec_Ptr_t * vNodes, Dsd_Manager_t * pManDsd, int fRecursive, int * pCounters );
static int Abc_NodeIsForDsd( Abc_Obj_t * pNode );
static int Abc_NodeFindMuxVar( DdManager * dd, DdNode * bFunc, int nVars );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Derives the DSD network.]
Description [Takes the strashed network (pNtk), derives global BDDs for
the combinational outputs of this network, and decomposes these BDDs using
disjoint support decomposition. Finally, constructs and return a new
network, which is topologically equivalent to the decomposition tree.
Allocates and frees a new BDD manager and a new DSD manager.]
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkDsdGlobal( Abc_Ntk_t * pNtk, int fVerbose, int fPrint, int fShort )
{
DdManager * dd;
Abc_Ntk_t * pNtkNew;
assert( Abc_NtkIsStrash(pNtk) );
dd = (DdManager *)Abc_NtkBuildGlobalBdds( pNtk, 10000000, 1, 1, fVerbose );
if ( dd == NULL )
return NULL;
if ( fVerbose )
printf( "Shared BDD size = %6d nodes.\n", Cudd_ReadKeys(dd) - Cudd_ReadDead(dd) );
// transform the result of mapping into a BDD network
pNtkNew = Abc_NtkDsdInternal( pNtk, fVerbose, fPrint, fShort );
Extra_StopManager( dd );
if ( pNtkNew == NULL )
return NULL;
// copy EXDC network
if ( pNtk->pExdc )
pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );
if ( !Abc_NtkCheck( pNtkNew ) )
{
printf( "Abc_NtkDsdGlobal: The network check has failed.\n" );
Abc_NtkDelete( pNtkNew );
return NULL;
}
return pNtkNew;
}
/**Function*************************************************************
Synopsis [Constructs the decomposed network.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Ntk_t * Abc_NtkDsdInternal( Abc_Ntk_t * pNtk, int fVerbose, int fPrint, int fShort )
{
char ** ppNamesCi, ** ppNamesCo;
Vec_Ptr_t * vFuncsGlob;
Dsd_Manager_t * pManDsd;
Abc_Ntk_t * pNtkNew;
DdManager * dd;
Abc_Obj_t * pObj;
int i;
// complement the global functions
vFuncsGlob = Vec_PtrAlloc( Abc_NtkCoNum(pNtk) );
Abc_NtkForEachCo( pNtk, pObj, i )
Vec_PtrPush( vFuncsGlob, Cudd_NotCond(Abc_ObjGlobalBdd(pObj), Abc_ObjFaninC0(pObj)) );
// perform the decomposition
dd = (DdManager *)Abc_NtkGlobalBddMan(pNtk);
pManDsd = Dsd_ManagerStart( dd, Abc_NtkCiNum(pNtk), fVerbose );
if ( pManDsd == NULL )
{
Vec_PtrFree( vFuncsGlob );
Cudd_Quit( dd );
return NULL;
}
Dsd_Decompose( pManDsd, (DdNode **)vFuncsGlob->pArray, Abc_NtkCoNum(pNtk) );
Vec_PtrFree( vFuncsGlob );
Abc_NtkFreeGlobalBdds( pNtk, 0 );
// start the new network
pNtkNew = Abc_NtkStartFrom( pNtk, ABC_NTK_LOGIC, ABC_FUNC_BDD );
// make sure the new manager has enough inputs
Cudd_bddIthVar( (DdManager *)pNtkNew->pManFunc, dd->size-1 );
// put the results into the new network (save new CO drivers in old CO drivers)
Abc_NtkDsdConstruct( pManDsd, pNtk, pNtkNew );
// finalize the new network
Abc_NtkFinalize( pNtk, pNtkNew );
// fix the problem with complemented and duplicated CO edges
Abc_NtkLogicMakeSimpleCos( pNtkNew, 0 );
if ( fPrint )
{
ppNamesCi = Abc_NtkCollectCioNames( pNtk, 0 );
ppNamesCo = Abc_NtkCollectCioNames( pNtk, 1 );
Dsd_TreePrint( stdout, pManDsd, ppNamesCi, ppNamesCo, fShort, -1 );
ABC_FREE( ppNamesCi );
ABC_FREE( ppNamesCo );
}
// stop the DSD manager
Dsd_ManagerStop( pManDsd );
return pNtkNew;
}
/**Function*************************************************************
Synopsis [Constructs the decomposed network.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkDsdConstruct( Dsd_Manager_t * pManDsd, Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew )
{
Dsd_Node_t ** ppNodesDsd;
Dsd_Node_t * pNodeDsd;
Abc_Obj_t * pNode, * pNodeNew, * pDriver;
int i, nNodesDsd;
// save the CI nodes in the DSD nodes
Abc_AigConst1(pNtk)->pCopy = pNodeNew = Abc_NtkCreateNodeConst1(pNtkNew);
Dsd_NodeSetMark( Dsd_ManagerReadConst1(pManDsd), (int)(ABC_PTRINT_T)pNodeNew );
Abc_NtkForEachCi( pNtk, pNode, i )
{
pNodeDsd = Dsd_ManagerReadInput( pManDsd, i );
Dsd_NodeSetMark( pNodeDsd, (int)(ABC_PTRINT_T)pNode->pCopy );
}
// collect DSD nodes in DFS order (leaves and const1 are not collected)
ppNodesDsd = Dsd_TreeCollectNodesDfs( pManDsd, &nNodesDsd );
for ( i = 0; i < nNodesDsd; i++ )
Abc_NtkDsdConstructNode( pManDsd, ppNodesDsd[i], pNtkNew, NULL );
ABC_FREE( ppNodesDsd );
// set the pointers to the CO drivers
Abc_NtkForEachCo( pNtk, pNode, i )
{
pDriver = Abc_ObjFanin0( pNode );
if ( !Abc_ObjIsNode(pDriver) )
continue;
if ( !Abc_AigNodeIsAnd(pDriver) )
continue;
pNodeDsd = Dsd_ManagerReadRoot( pManDsd, i );
pNodeNew = (Abc_Obj_t *)(ABC_PTRINT_T)Dsd_NodeReadMark( Dsd_Regular(pNodeDsd) );
assert( !Abc_ObjIsComplement(pNodeNew) );
pDriver->pCopy = Abc_ObjNotCond( pNodeNew, Dsd_IsComplement(pNodeDsd) );
}
}
/**Function*************************************************************
Synopsis [Performs DSD using the manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Obj_t * Abc_NtkDsdConstructNode( Dsd_Manager_t * pManDsd, Dsd_Node_t * pNodeDsd, Abc_Ntk_t * pNtkNew, int * pCounters )
{
DdManager * ddDsd = Dsd_ManagerReadDd( pManDsd );
DdManager * ddNew = (DdManager *)pNtkNew->pManFunc;
Dsd_Node_t * pFaninDsd;
Abc_Obj_t * pNodeNew, * pFanin;
DdNode * bLocal, * bTemp, * bVar;
Dsd_Type_t Type;
int i, nDecs;
// create the new node
pNodeNew = Abc_NtkCreateNode( pNtkNew );
// add the fanins
Type = Dsd_NodeReadType( pNodeDsd );
nDecs = Dsd_NodeReadDecsNum( pNodeDsd );
assert( nDecs > 1 );
for ( i = 0; i < nDecs; i++ )
{
pFaninDsd = Dsd_NodeReadDec( pNodeDsd, i );
pFanin = (Abc_Obj_t *)(ABC_PTRINT_T)Dsd_NodeReadMark(Dsd_Regular(pFaninDsd));
Abc_ObjAddFanin( pNodeNew, pFanin );
assert( Type == DSD_NODE_OR || !Dsd_IsComplement(pFaninDsd) );
}
// create the local function depending on the type of the node
ddNew = (DdManager *)pNtkNew->pManFunc;
switch ( Type )
{
case DSD_NODE_CONST1:
{
bLocal = ddNew->one; Cudd_Ref( bLocal );
break;
}
case DSD_NODE_OR:
{
bLocal = Cudd_Not(ddNew->one); Cudd_Ref( bLocal );
for ( i = 0; i < nDecs; i++ )
{
pFaninDsd = Dsd_NodeReadDec( pNodeDsd, i );
bVar = Cudd_NotCond( ddNew->vars[i], Dsd_IsComplement(pFaninDsd) );
bLocal = Cudd_bddOr( ddNew, bTemp = bLocal, bVar ); Cudd_Ref( bLocal );
Cudd_RecursiveDeref( ddNew, bTemp );
}
break;
}
case DSD_NODE_EXOR:
{
bLocal = Cudd_Not(ddNew->one); Cudd_Ref( bLocal );
for ( i = 0; i < nDecs; i++ )
{
bLocal = Cudd_bddXor( ddNew, bTemp = bLocal, ddNew->vars[i] ); Cudd_Ref( bLocal );
Cudd_RecursiveDeref( ddNew, bTemp );
}
break;
}
case DSD_NODE_PRIME:
{
if ( pCounters )
{
if ( nDecs < 10 )
pCounters[nDecs]++;
else
pCounters[10]++;
}
bLocal = Dsd_TreeGetPrimeFunction( ddDsd, pNodeDsd ); Cudd_Ref( bLocal );
bLocal = Extra_TransferLevelByLevel( ddDsd, ddNew, bTemp = bLocal ); Cudd_Ref( bLocal );
/*
if ( nDecs == 3 )
{
Extra_bddPrint( ddDsd, bTemp );
printf( "\n" );
}
*/
Cudd_RecursiveDeref( ddDsd, bTemp );
// bLocal is now in the new BDD manager
break;
}
default:
{
assert( 0 );
break;
}
}
pNodeNew->pData = bLocal;
Dsd_NodeSetMark( pNodeDsd, (int)(ABC_PTRINT_T)pNodeNew );
return pNodeNew;
}
/**Function*************************************************************
Synopsis [Recursively decomposes internal nodes.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkDsdLocal( Abc_Ntk_t * pNtk, int fVerbose, int fRecursive )
{
Dsd_Manager_t * pManDsd;
DdManager * dd = (DdManager *)pNtk->pManFunc;
Vec_Ptr_t * vNodes;
int i;
int pCounters[11] = {0};
assert( Abc_NtkIsBddLogic(pNtk) );
// make the network minimum base
Abc_NtkMinimumBase( pNtk );
// start the DSD manager
pManDsd = Dsd_ManagerStart( dd, dd->size, 0 );
// collect nodes for decomposition
vNodes = Abc_NtkCollectNodesForDsd( pNtk );
for ( i = 0; i < vNodes->nSize; i++ )
Abc_NodeDecompDsdAndMux( (Abc_Obj_t *)vNodes->pArray[i], vNodes, pManDsd, fRecursive, pCounters );
Vec_PtrFree( vNodes );
printf( "Number of non-decomposable functions:\n" );
for ( i = 3; i < 10; i++ )
printf( "Inputs = %d. Functions = %6d.\n", i, pCounters[i] );
printf( "Inputs > %d. Functions = %6d.\n", 9, pCounters[10] );
// stop the DSD manager
Dsd_ManagerStop( pManDsd );
// make sure everything is okay
if ( !Abc_NtkCheck( pNtk ) )
{
printf( "Abc_NtkDsdRecursive: The network check has failed.\n" );
return 0;
}
return 1;
}
/**Function*************************************************************
Synopsis [Collects the nodes that may need decomposition.]
Description [The nodes that do not need decomposition are those
whose BDD has more internal nodes than the support size.]
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Ptr_t * Abc_NtkCollectNodesForDsd( Abc_Ntk_t * pNtk )
{
Vec_Ptr_t * vNodes;
Abc_Obj_t * pNode;
int i;
vNodes = Vec_PtrAlloc( 100 );
Abc_NtkForEachNode( pNtk, pNode, i )
{
if ( Abc_NodeIsForDsd(pNode) )
Vec_PtrPush( vNodes, pNode );
}
return vNodes;
}
/**Function*************************************************************
Synopsis [Performs decomposition of one node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NodeDecompDsdAndMux( Abc_Obj_t * pNode, Vec_Ptr_t * vNodes, Dsd_Manager_t * pManDsd, int fRecursive, int * pCounters )
{
DdManager * dd = (DdManager *)pNode->pNtk->pManFunc;
Abc_Obj_t * pRoot = NULL, * pFanin, * pNode1, * pNode2, * pNodeC;
Dsd_Node_t ** ppNodesDsd, * pNodeDsd, * pFaninDsd;
int i, nNodesDsd, iVar, fCompl;
// try disjoint support decomposition
pNodeDsd = Dsd_DecomposeOne( pManDsd, (DdNode *)pNode->pData );
fCompl = Dsd_IsComplement( pNodeDsd );
pNodeDsd = Dsd_Regular( pNodeDsd );
// determine what decomposition to use
if ( !fRecursive || Dsd_NodeReadDecsNum(pNodeDsd) != Abc_ObjFaninNum(pNode) )
{ // perform DSD
// set the inputs
Abc_ObjForEachFanin( pNode, pFanin, i )
{
pFaninDsd = Dsd_ManagerReadInput( pManDsd, i );
Dsd_NodeSetMark( pFaninDsd, (int)(ABC_PTRINT_T)pFanin );
}
// construct the intermediate nodes
ppNodesDsd = Dsd_TreeCollectNodesDfsOne( pManDsd, pNodeDsd, &nNodesDsd );
for ( i = 0; i < nNodesDsd; i++ )
{
pRoot = Abc_NtkDsdConstructNode( pManDsd, ppNodesDsd[i], pNode->pNtk, pCounters );
if ( Abc_NodeIsForDsd(pRoot) && fRecursive )
Vec_PtrPush( vNodes, pRoot );
}
ABC_FREE( ppNodesDsd );
assert(pRoot);
// remove the current fanins
Abc_ObjRemoveFanins( pNode );
// add fanin to the root
Abc_ObjAddFanin( pNode, pRoot );
// update the function to be that of buffer
Cudd_RecursiveDeref( dd, (DdNode *)pNode->pData );
pNode->pData = Cudd_NotCond( (DdNode *)dd->vars[0], fCompl ); Cudd_Ref( (DdNode *)pNode->pData );
}
else // perform MUX-decomposition
{
// get the cofactoring variable
iVar = Abc_NodeFindMuxVar( dd, (DdNode *)pNode->pData, Abc_ObjFaninNum(pNode) );
pNodeC = Abc_ObjFanin( pNode, iVar );
// get the negative cofactor
pNode1 = Abc_NtkCloneObj( pNode );
pNode1->pData = Cudd_Cofactor( dd, (DdNode *)pNode->pData, Cudd_Not(dd->vars[iVar]) ); Cudd_Ref( (DdNode *)pNode1->pData );
Abc_NodeMinimumBase( pNode1 );
if ( Abc_NodeIsForDsd(pNode1) )
Vec_PtrPush( vNodes, pNode1 );
// get the positive cofactor
pNode2 = Abc_NtkCloneObj( pNode );
pNode2->pData = Cudd_Cofactor( dd, (DdNode *)pNode->pData, dd->vars[iVar] ); Cudd_Ref( (DdNode *)pNode2->pData );
Abc_NodeMinimumBase( pNode2 );
if ( Abc_NodeIsForDsd(pNode2) )
Vec_PtrPush( vNodes, pNode2 );
// remove the current fanins
Abc_ObjRemoveFanins( pNode );
// add new fanins
Abc_ObjAddFanin( pNode, pNodeC );
Abc_ObjAddFanin( pNode, pNode2 );
Abc_ObjAddFanin( pNode, pNode1 );
// update the function to be that of MUX
Cudd_RecursiveDeref( dd, (DdNode *)pNode->pData );
pNode->pData = Cudd_bddIte( dd, dd->vars[0], dd->vars[1], dd->vars[2] ); Cudd_Ref( (DdNode *)pNode->pData );
}
}
/**Function*************************************************************
Synopsis [Checks if the node should be decomposed by DSD.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NodeIsForDsd( Abc_Obj_t * pNode )
{
// DdManager * dd = pNode->pNtk->pManFunc;
// DdNode * bFunc, * bFunc0, * bFunc1;
assert( Abc_ObjIsNode(pNode) );
// if ( Cudd_DagSize(pNode->pData)-1 > Abc_ObjFaninNum(pNode) )
// return 1;
// return 0;
/*
// this does not catch things like a(b+c), which should be decomposed
for ( bFunc = Cudd_Regular(pNode->pData); !cuddIsConstant(bFunc); )
{
bFunc0 = Cudd_Regular( cuddE(bFunc) );
bFunc1 = cuddT(bFunc);
if ( bFunc0 == b1 )
bFunc = bFunc1;
else if ( bFunc1 == b1 || bFunc0 == bFunc1 )
bFunc = bFunc0;
else
return 1;
}
*/
if ( Abc_ObjFaninNum(pNode) > 2 )
return 1;
return 0;
}
/**Function*************************************************************
Synopsis [Determines a cofactoring variable.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NodeFindMuxVar( DdManager * dd, DdNode * bFunc, int nVars )
{
DdNode * bVar, * bCof0, * bCof1;
int SuppSumMin = 1000000;
int i, nSSD, nSSQ, iVar;
// printf( "\n\nCofactors:\n\n" );
iVar = -1;
for ( i = 0; i < nVars; i++ )
{
bVar = dd->vars[i];
bCof0 = Cudd_Cofactor( dd, bFunc, Cudd_Not(bVar) ); Cudd_Ref( bCof0 );
bCof1 = Cudd_Cofactor( dd, bFunc, bVar ); Cudd_Ref( bCof1 );
// nodD = Cudd_DagSize(bCof0);
// nodQ = Cudd_DagSize(bCof1);
// printf( "+%02d: D=%2d. Q=%2d. ", i, nodD, nodQ );
// printf( "S=%2d. D=%2d. ", nodD + nodQ, abs(nodD-nodQ) );
nSSD = Cudd_SupportSize( dd, bCof0 );
nSSQ = Cudd_SupportSize( dd, bCof1 );
// printf( "SD=%2d. SQ=%2d. ", nSSD, nSSQ );
// printf( "S=%2d. D=%2d. ", nSSD + nSSQ, abs(nSSD - nSSQ) );
// printf( "Cost=%3d. ", Cost(nodD,nodQ,nSSD,nSSQ) );
// printf( "\n" );
Cudd_RecursiveDeref( dd, bCof0 );
Cudd_RecursiveDeref( dd, bCof1 );
if ( SuppSumMin > nSSD + nSSQ )
{
SuppSumMin = nSSD + nSSQ;
iVar = i;
}
}
return iVar;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|