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
|
/**CFile****************************************************************
FileName [abcRefactor.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Network and node package.]
Synopsis [Resynthesis based on collapsing and refactoring.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: abcRefactor.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "base/abc/abc.h"
#include "bool/dec/dec.h"
#include "misc/extra/extraBdd.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
typedef struct Abc_ManRef_t_ Abc_ManRef_t;
struct Abc_ManRef_t_
{
// user specified parameters
int nNodeSizeMax; // the limit on the size of the supernode
int nConeSizeMax; // the limit on the size of the containing cone
int fVerbose; // the verbosity flag
// internal data structures
DdManager * dd; // the BDD manager
Vec_Str_t * vCube; // temporary
Vec_Int_t * vForm; // temporary
Vec_Ptr_t * vVisited; // temporary
Vec_Ptr_t * vLeaves; // temporary
// node statistics
int nLastGain;
int nNodesConsidered;
int nNodesRefactored;
int nNodesGained;
int nNodesBeg;
int nNodesEnd;
// runtime statistics
abctime timeCut;
abctime timeBdd;
abctime timeDcs;
abctime timeSop;
abctime timeFact;
abctime timeEval;
abctime timeRes;
abctime timeNtk;
abctime timeTotal;
};
static void Abc_NtkManRefPrintStats( Abc_ManRef_t * p );
static Abc_ManRef_t * Abc_NtkManRefStart( int nNodeSizeMax, int nConeSizeMax, int fUseDcs, int fVerbose );
static void Abc_NtkManRefStop( Abc_ManRef_t * p );
static Dec_Graph_t * Abc_NodeRefactor( Abc_ManRef_t * p, Abc_Obj_t * pNode, Vec_Ptr_t * vFanins, int fUpdateLevel, int fUseZeros, int fUseDcs, int fVerbose );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Performs incremental resynthesis of the AIG.]
Description [Starting from each node, computes a reconvergence-driven cut,
derives BDD of the cut function, constructs ISOP, factors the ISOP,
and replaces the current implementation of the MFFC of the node by the
new factored form, if the number of AIG nodes is reduced and the total
number of levels of the AIG network is not increated. Returns the
number of AIG nodes saved.]
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkRefactor( Abc_Ntk_t * pNtk, int nNodeSizeMax, int nConeSizeMax, int fUpdateLevel, int fUseZeros, int fUseDcs, int fVerbose )
{
extern void Dec_GraphUpdateNetwork( Abc_Obj_t * pRoot, Dec_Graph_t * pGraph, int fUpdateLevel, int nGain );
ProgressBar * pProgress;
Abc_ManRef_t * pManRef;
Abc_ManCut_t * pManCut;
Dec_Graph_t * pFForm;
Vec_Ptr_t * vFanins;
Abc_Obj_t * pNode;
abctime clk, clkStart = Abc_Clock();
int i, nNodes;
assert( Abc_NtkIsStrash(pNtk) );
// cleanup the AIG
Abc_AigCleanup((Abc_Aig_t *)pNtk->pManFunc);
// start the managers
pManCut = Abc_NtkManCutStart( nNodeSizeMax, nConeSizeMax, 2, 1000 );
pManRef = Abc_NtkManRefStart( nNodeSizeMax, nConeSizeMax, fUseDcs, fVerbose );
pManRef->vLeaves = Abc_NtkManCutReadCutLarge( pManCut );
// compute the reverse levels if level update is requested
if ( fUpdateLevel )
Abc_NtkStartReverseLevels( pNtk, 0 );
// resynthesize each node once
pManRef->nNodesBeg = Abc_NtkNodeNum(pNtk);
nNodes = Abc_NtkObjNumMax(pNtk);
pProgress = Extra_ProgressBarStart( stdout, nNodes );
Abc_NtkForEachNode( pNtk, pNode, i )
{
Extra_ProgressBarUpdate( pProgress, i, NULL );
// skip the constant node
// if ( Abc_NodeIsConst(pNode) )
// continue;
// skip persistant nodes
if ( Abc_NodeIsPersistant(pNode) )
continue;
// skip the nodes with many fanouts
if ( Abc_ObjFanoutNum(pNode) > 1000 )
continue;
// stop if all nodes have been tried once
if ( i >= nNodes )
break;
// compute a reconvergence-driven cut
clk = Abc_Clock();
vFanins = Abc_NodeFindCut( pManCut, pNode, fUseDcs );
pManRef->timeCut += Abc_Clock() - clk;
// evaluate this cut
clk = Abc_Clock();
pFForm = Abc_NodeRefactor( pManRef, pNode, vFanins, fUpdateLevel, fUseZeros, fUseDcs, fVerbose );
pManRef->timeRes += Abc_Clock() - clk;
if ( pFForm == NULL )
continue;
// acceptable replacement found, update the graph
clk = Abc_Clock();
Dec_GraphUpdateNetwork( pNode, pFForm, fUpdateLevel, pManRef->nLastGain );
pManRef->timeNtk += Abc_Clock() - clk;
Dec_GraphFree( pFForm );
// {
// extern int s_TotalChanges;
// s_TotalChanges++;
// }
}
Extra_ProgressBarStop( pProgress );
pManRef->timeTotal = Abc_Clock() - clkStart;
pManRef->nNodesEnd = Abc_NtkNodeNum(pNtk);
// print statistics of the manager
if ( fVerbose )
Abc_NtkManRefPrintStats( pManRef );
// delete the managers
Abc_NtkManCutStop( pManCut );
Abc_NtkManRefStop( pManRef );
// put the nodes into the DFS order and reassign their IDs
Abc_NtkReassignIds( pNtk );
// Abc_AigCheckFaninOrder( pNtk->pManFunc );
// fix the levels
if ( fUpdateLevel )
Abc_NtkStopReverseLevels( pNtk );
else
Abc_NtkLevel( pNtk );
// check
if ( !Abc_NtkCheck( pNtk ) )
{
printf( "Abc_NtkRefactor: The network check has failed.\n" );
return 0;
}
return 1;
}
/**Function*************************************************************
Synopsis [Resynthesizes the node using refactoring.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Dec_Graph_t * Abc_NodeRefactor( Abc_ManRef_t * p, Abc_Obj_t * pNode, Vec_Ptr_t * vFanins, int fUpdateLevel, int fUseZeros, int fUseDcs, int fVerbose )
{
extern DdNode * Abc_NodeConeBdd( DdManager * dd, DdNode ** pbVars, Abc_Obj_t * pNode, Vec_Ptr_t * vFanins, Vec_Ptr_t * vVisited );
extern DdNode * Abc_NodeConeDcs( DdManager * dd, DdNode ** pbVarsX, DdNode ** pbVarsY, Vec_Ptr_t * vLeaves, Vec_Ptr_t * vRoots, Vec_Ptr_t * vVisited );
extern char * Abc_ConvertBddToSop( Mem_Flex_t * pMan, DdManager * dd, DdNode * bFuncOn, DdNode * bFuncOnDc, int nFanins, int fAllPrimes, Vec_Str_t * vCube, int fMode );
extern int Dec_GraphToNetworkCount( Abc_Obj_t * pRoot, Dec_Graph_t * pGraph, int NodeMax, int LevelMax );
int fVeryVerbose = 0;
Abc_Obj_t * pFanin;
Dec_Graph_t * pFForm;
DdNode * bNodeFunc;
int nNodesSaved, nNodesAdded, i;
abctime clk;
char * pSop;
int Required;
Required = fUpdateLevel? Abc_ObjRequiredLevel(pNode) : ABC_INFINITY;
p->nNodesConsidered++;
// get the function of the cut
clk = Abc_Clock();
bNodeFunc = Abc_NodeConeBdd( p->dd, p->dd->vars, pNode, vFanins, p->vVisited ); Cudd_Ref( bNodeFunc );
p->timeBdd += Abc_Clock() - clk;
// if don't-care are used, transform the function into ISOP
if ( fUseDcs )
{
DdNode * bNodeDc, * bNodeOn, * bNodeOnDc;
int nMints, nMintsDc;
clk = Abc_Clock();
// get the don't-cares
bNodeDc = Abc_NodeConeDcs( p->dd, p->dd->vars + vFanins->nSize, p->dd->vars, p->vLeaves, vFanins, p->vVisited ); Cudd_Ref( bNodeDc );
nMints = (1 << vFanins->nSize);
nMintsDc = (int)Cudd_CountMinterm( p->dd, bNodeDc, vFanins->nSize );
// printf( "Percentage of minterms = %5.2f.\n", 100.0 * nMintsDc / nMints );
// get the ISF
bNodeOn = Cudd_bddAnd( p->dd, bNodeFunc, Cudd_Not(bNodeDc) ); Cudd_Ref( bNodeOn );
bNodeOnDc = Cudd_bddOr ( p->dd, bNodeFunc, bNodeDc ); Cudd_Ref( bNodeOnDc );
Cudd_RecursiveDeref( p->dd, bNodeFunc );
Cudd_RecursiveDeref( p->dd, bNodeDc );
// get the ISOP
bNodeFunc = Cudd_bddIsop( p->dd, bNodeOn, bNodeOnDc ); Cudd_Ref( bNodeFunc );
Cudd_RecursiveDeref( p->dd, bNodeOn );
Cudd_RecursiveDeref( p->dd, bNodeOnDc );
p->timeDcs += Abc_Clock() - clk;
}
// always accept the case of constant node
if ( Cudd_IsConstant(bNodeFunc) )
{
p->nLastGain = Abc_NodeMffcSize( pNode );
p->nNodesGained += p->nLastGain;
p->nNodesRefactored++;
Cudd_RecursiveDeref( p->dd, bNodeFunc );
if ( Cudd_IsComplement(bNodeFunc) )
return Dec_GraphCreateConst0();
return Dec_GraphCreateConst1();
}
// get the SOP of the cut
clk = Abc_Clock();
pSop = Abc_ConvertBddToSop( NULL, p->dd, bNodeFunc, bNodeFunc, vFanins->nSize, 0, p->vCube, -1 );
p->timeSop += Abc_Clock() - clk;
// get the factored form
clk = Abc_Clock();
pFForm = Dec_Factor( pSop );
ABC_FREE( pSop );
p->timeFact += Abc_Clock() - clk;
// mark the fanin boundary
// (can mark only essential fanins, belonging to bNodeFunc!)
Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pFanin, i )
pFanin->vFanouts.nSize++;
// label MFFC with current traversal ID
Abc_NtkIncrementTravId( pNode->pNtk );
nNodesSaved = Abc_NodeMffcLabelAig( pNode );
// unmark the fanin boundary and set the fanins as leaves in the form
Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pFanin, i )
{
pFanin->vFanouts.nSize--;
Dec_GraphNode(pFForm, i)->pFunc = pFanin;
}
// detect how many new nodes will be added (while taking into account reused nodes)
clk = Abc_Clock();
nNodesAdded = Dec_GraphToNetworkCount( pNode, pFForm, nNodesSaved, Required );
p->timeEval += Abc_Clock() - clk;
// quit if there is no improvement
if ( nNodesAdded == -1 || (nNodesAdded == nNodesSaved && !fUseZeros) )
{
Cudd_RecursiveDeref( p->dd, bNodeFunc );
Dec_GraphFree( pFForm );
return NULL;
}
// compute the total gain in the number of nodes
p->nLastGain = nNodesSaved - nNodesAdded;
p->nNodesGained += p->nLastGain;
p->nNodesRefactored++;
// report the progress
if ( fVeryVerbose )
{
printf( "Node %6s : ", Abc_ObjName(pNode) );
printf( "Cone = %2d. ", vFanins->nSize );
printf( "BDD = %2d. ", Cudd_DagSize(bNodeFunc) );
printf( "FF = %2d. ", 1 + Dec_GraphNodeNum(pFForm) );
printf( "MFFC = %2d. ", nNodesSaved );
printf( "Add = %2d. ", nNodesAdded );
printf( "GAIN = %2d. ", p->nLastGain );
printf( "\n" );
}
Cudd_RecursiveDeref( p->dd, bNodeFunc );
return pFForm;
}
/**Function*************************************************************
Synopsis [Starts the resynthesis manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_ManRef_t * Abc_NtkManRefStart( int nNodeSizeMax, int nConeSizeMax, int fUseDcs, int fVerbose )
{
Abc_ManRef_t * p;
p = ABC_ALLOC( Abc_ManRef_t, 1 );
memset( p, 0, sizeof(Abc_ManRef_t) );
p->vCube = Vec_StrAlloc( 100 );
p->vVisited = Vec_PtrAlloc( 100 );
p->nNodeSizeMax = nNodeSizeMax;
p->nConeSizeMax = nConeSizeMax;
p->fVerbose = fVerbose;
// start the BDD manager
if ( fUseDcs )
p->dd = Cudd_Init( p->nNodeSizeMax + p->nConeSizeMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
else
p->dd = Cudd_Init( p->nNodeSizeMax, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
Cudd_zddVarsFromBddVars( p->dd, 2 );
return p;
}
/**Function*************************************************************
Synopsis [Stops the resynthesis manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkManRefStop( Abc_ManRef_t * p )
{
Extra_StopManager( p->dd );
Vec_PtrFree( p->vVisited );
Vec_StrFree( p->vCube );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis [Stops the resynthesis manager.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkManRefPrintStats( Abc_ManRef_t * p )
{
printf( "Refactoring statistics:\n" );
printf( "Nodes considered = %8d.\n", p->nNodesConsidered );
printf( "Nodes refactored = %8d.\n", p->nNodesRefactored );
printf( "Gain = %8d. (%6.2f %%).\n", p->nNodesBeg-p->nNodesEnd, 100.0*(p->nNodesBeg-p->nNodesEnd)/p->nNodesBeg );
ABC_PRT( "Cuts ", p->timeCut );
ABC_PRT( "Resynthesis", p->timeRes );
ABC_PRT( " BDD ", p->timeBdd );
ABC_PRT( " DCs ", p->timeDcs );
ABC_PRT( " SOP ", p->timeSop );
ABC_PRT( " FF ", p->timeFact );
ABC_PRT( " Eval ", p->timeEval );
ABC_PRT( "AIG update ", p->timeNtk );
ABC_PRT( "TOTAL ", p->timeTotal );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
