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
|
/**CFile****************************************************************
FileName [ifMap.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Mapping procedures.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifMap.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
/*
Ideas to try:
- reverse order of area recovery
- ordering of the outputs by size
- merging Delay, Delay2, and Area
- expand/reduce area recovery
- use average nrefs for tie-breaking
*/
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Counts the number of 1s in the signature.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int If_WordCountOnes( unsigned uWord )
{
uWord = (uWord & 0x55555555) + ((uWord>>1) & 0x55555555);
uWord = (uWord & 0x33333333) + ((uWord>>2) & 0x33333333);
uWord = (uWord & 0x0F0F0F0F) + ((uWord>>4) & 0x0F0F0F0F);
uWord = (uWord & 0x00FF00FF) + ((uWord>>8) & 0x00FF00FF);
return (uWord & 0x0000FFFF) + (uWord>>16);
}
/**Function*************************************************************
Synopsis [Finds the best cut for the given node.]
Description [Mapping modes: delay (0), area flow (1), area (2).]
SideEffects []
SeeAlso []
***********************************************************************/
void If_ObjPerformMapping( If_Man_t * p, If_Obj_t * pObj, int Mode )
{
If_Cut_t * pCut0, * pCut1, * pCut;
int i, k, iCut;
assert( !If_ObjIsAnd(pObj->pFanin0) || pObj->pFanin0->nCuts > 1 );
assert( !If_ObjIsAnd(pObj->pFanin1) || pObj->pFanin1->nCuts > 1 );
// prepare
if ( Mode == 0 )
pObj->EstRefs = (float)pObj->nRefs;
else if ( Mode == 1 )
pObj->EstRefs = (float)((2.0 * pObj->EstRefs + pObj->nRefs) / 3.0);
else if ( Mode == 2 && pObj->nRefs > 0 )
If_CutDeref( p, If_ObjCutBest(pObj), 100 );
// recompute the parameters of the best cut
p->nCuts = 0;
p->nCutsMerged++;
if ( Mode )
{
pCut = If_ObjCutBest(pObj);
pCut->Delay = If_CutDelay( p, pCut );
assert( pCut->Delay <= pObj->Required + p->fEpsilon );
pCut->Area = (Mode == 2)? If_CutAreaDerefed( p, pCut, 100 ) : If_CutFlow( p, pCut );
// save the best cut from the previous iteration
If_CutCopy( p->ppCuts[p->nCuts++], pCut );
p->nCutsMerged++;
}
// prepare room for the next cut
iCut = p->nCuts;
pCut = p->ppCuts[iCut];
// generate cuts
If_ObjForEachCut( pObj->pFanin0, pCut0, i )
If_ObjForEachCut( pObj->pFanin1, pCut1, k )
{
// make sure K-feasible cut exists
if ( If_WordCountOnes(pCut0->uSign | pCut1->uSign) > p->pPars->nLutSize )
continue;
// merge the nodes
if ( !If_CutMerge( pCut0, pCut1, pCut ) )
continue;
// check if this cut is contained in any of the available cuts
pCut->uSign = pCut0->uSign | pCut1->uSign;
pCut->fCompl = 0;
// if ( p->pPars->pFuncCost == NULL && If_CutFilter( p, pCut ) ) // do not filter functionality cuts
if ( If_CutFilter( p, pCut ) )
continue;
// the cuts have been successfully merged
// compute the truth table
if ( p->pPars->fTruth )
If_CutComputeTruth( p, pCut, pCut0, pCut1, pObj->fCompl0, pObj->fCompl1 );
// compute the application-specific cost and depth
pCut->fUser = (p->pPars->pFuncCost != NULL);
pCut->Cost = p->pPars->pFuncCost? p->pPars->pFuncCost(pCut) : 0;
// check if the cut satisfies the required times
pCut->Delay = If_CutDelay( p, pCut );
// printf( "%.2f ", pCut->Delay );
if ( Mode && pCut->Delay > pObj->Required + p->fEpsilon )
continue;
// compute area of the cut (this area may depend on the application specific cost)
pCut->Area = (Mode == 2)? If_CutAreaDerefed( p, pCut, 100 ) : If_CutFlow( p, pCut );
pCut->AveRefs = (Mode == 0)? (float)0.0 : If_CutAverageRefs( p, pCut );
// make sure the cut is the last one (after filtering it may not be so)
assert( pCut == p->ppCuts[iCut] );
p->ppCuts[iCut] = p->ppCuts[p->nCuts];
p->ppCuts[p->nCuts] = pCut;
// count the cut
p->nCuts++;
p->nCutsMerged++;
// prepare room for the next cut
iCut = p->nCuts;
pCut = p->ppCuts[iCut];
}
assert( p->nCuts > 0 );
// sort if we have more cuts
If_ManSortCuts( p, Mode );
// decide how many cuts to use
pObj->nCuts = IF_MIN( p->nCuts + 1, p->nCutsUsed );
// take the first
If_ObjForEachCutStart( pObj, pCut, i, 1 )
If_CutCopy( pCut, p->ppCuts[i-1] );
assert( If_ObjCutBest(pObj)->nLeaves > 1 );
// ref the selected cut
if ( Mode == 2 && pObj->nRefs > 0 )
If_CutRef( p, If_ObjCutBest(pObj), 100 );
// find the largest cut
if ( p->nCutsMax < pObj->nCuts )
p->nCutsMax = pObj->nCuts;
}
/**Function*************************************************************
Synopsis [Finds the best cut for the choice node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void If_ObjMergeChoice( If_Man_t * p, If_Obj_t * pObj, int Mode )
{
If_Obj_t * pTemp;
If_Cut_t * pCutTemp, * pCut;
int i, iCut;
assert( pObj->pEquiv != NULL );
// prepare
if ( Mode == 2 && pObj->nRefs > 0 )
If_CutDeref( p, If_ObjCutBest(pObj), 100 );
// prepare room for the next cut
p->nCuts = 0;
iCut = p->nCuts;
pCut = p->ppCuts[iCut];
// generate cuts
for ( pTemp = pObj; pTemp; pTemp = pTemp->pEquiv )
If_ObjForEachCutStart( pTemp, pCutTemp, i, 1 )
{
assert( pTemp->nCuts > 1 );
assert( pTemp == pObj || pTemp->nRefs == 0 );
// copy the cut into storage
If_CutCopy( pCut, pCutTemp );
// check if this cut is contained in any of the available cuts
if ( If_CutFilter( p, pCut ) )
continue;
// the cuts have been successfully merged
// check if the cut satisfies the required times
assert( pCut->Delay == If_CutDelay( p, pCut ) );
if ( Mode && pCut->Delay > pObj->Required + p->fEpsilon )
continue;
// set the phase attribute
pCut->fCompl ^= (pObj->fPhase ^ pTemp->fPhase);
// compute area of the cut (this area may depend on the application specific cost)
pCut->Area = (Mode == 2)? If_CutAreaDerefed( p, pCut, 100 ) : If_CutFlow( p, pCut );
pCut->AveRefs = (Mode == 0)? (float)0.0 : If_CutAverageRefs( p, pCut );
// make sure the cut is the last one (after filtering it may not be so)
assert( pCut == p->ppCuts[iCut] );
p->ppCuts[iCut] = p->ppCuts[p->nCuts];
p->ppCuts[p->nCuts] = pCut;
// count the cut
p->nCuts++;
// prepare room for the next cut
iCut = p->nCuts;
pCut = p->ppCuts[iCut];
// quit if we exceeded the number of cuts
if ( p->nCuts >= p->pPars->nCutsMax * p->pPars->nCutsMax )
break;
}
assert( p->nCuts > 0 );
// sort if we have more cuts
If_ManSortCuts( p, Mode );
// decide how many cuts to use
pObj->nCuts = IF_MIN( p->nCuts + 1, p->nCutsUsed );
// take the first
If_ObjForEachCutStart( pObj, pCut, i, 1 )
If_CutCopy( pCut, p->ppCuts[i-1] );
assert( If_ObjCutBest(pObj)->nLeaves > 1 );
// ref the selected cut
if ( Mode == 2 && pObj->nRefs > 0 )
If_CutRef( p, If_ObjCutBest(pObj), 100 );
// find the largest cut
if ( p->nCutsMax < pObj->nCuts )
p->nCutsMax = pObj->nCuts;
}
/**Function*************************************************************
Synopsis [Performs one mapping pass over all nodes.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_ManPerformMappingRound( If_Man_t * p, int nCutsUsed, int Mode, int fRequired, char * pLabel )
{
ProgressBar * pProgress;
If_Obj_t * pObj;
int i, clk = clock();
assert( Mode >= 0 && Mode <= 2 );
// set the cut number
p->nCutsUsed = nCutsUsed;
p->nCutsMerged = 0;
p->nCutsSaved = 0;
p->nCutsMax = 0;
// map the internal nodes
pProgress = Extra_ProgressBarStart( stdout, If_ManObjNum(p) );
If_ManForEachNode( p, pObj, i )
{
Extra_ProgressBarUpdate( pProgress, i, pLabel );
If_ObjPerformMapping( p, pObj, Mode );
if ( pObj->fRepr )
If_ObjMergeChoice( p, pObj, Mode );
}
Extra_ProgressBarStop( pProgress );
// compute required times and stats
if ( fRequired )
{
If_ManComputeRequired( p, Mode==0 );
if ( p->pPars->fVerbose )
{
char Symb = (Mode == 0)? 'D' : ((Mode == 1)? 'F' : 'A');
printf( "%c: Del = %6.2f. Area = %8.2f. Cuts = %8d. Lim = %2d. Ave = %5.2f. ",
Symb, p->RequiredGlo, p->AreaGlo, p->nCutsMerged, p->nCutsUsed, 1.0 * p->nCutsMerged / If_ManAndNum(p) );
PRT( "T", clock() - clk );
// printf( "Saved cuts = %d.\n", p->nCutsSaved );
// printf( "Max number of cuts = %d. Average number of cuts = %5.2f.\n",
// p->nCutsMax, 1.0 * p->nCutsMerged / If_ManAndNum(p) );
}
}
return 1;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
