1 /**CFile****************************************************************
2
3 FileName [bmcMaj2.c]
4
5 SystemName [ABC: Logic synthesis and verification system.]
6
7 PackageName [SAT-based bounded model checking.]
8
9 Synopsis [Exact synthesis with majority gates.]
10
11 Author [Alan Mishchenko]
12
13 Affiliation [UC Berkeley]
14
15 Date [Ver. 1.0. Started - October 1, 2017.]
16
17 Revision [$Id: bmcMaj.c,v 1.00 2017/10/01 00:00:00 alanmi Exp $]
18
19 ***********************************************************************/
20
21 #include "bmc.h"
22 #include "misc/extra/extra.h"
23 #include "misc/util/utilTruth.h"
24 #include "sat/cnf/cnf.h"
25 #include "sat/bsat/satStore.h"
26
27 ABC_NAMESPACE_IMPL_START
28
29 ////////////////////////////////////////////////////////////////////////
30 /// DECLARATIONS ///
31 ////////////////////////////////////////////////////////////////////////
32
33 #define MAJ_NOBJS 32 // Const0 + Const1 + nVars + nNodes
34
35 typedef struct Maj_Man_t_ Maj_Man_t;
36 struct Maj_Man_t_
37 {
38 int nVars; // inputs
39 int nNodes; // internal nodes
40 int nObjs; // total objects (2 consts, nVars inputs, nNodes internal nodes)
41 int nWords; // the truth table size in 64-bit words
42 int iVar; // the next available SAT variable
43 int fUseConst; // use constant fanins
44 int fUseLine; // use cascade topology
45 int fUseRand; // use random topology
46 int nRands; // number of random connections
47 int fVerbose; // verbose flag
48 Vec_Wrd_t * vInfo; // Const0 + Const1 + nVars + nNodes + Maj(nVars)
49 int VarMarks[MAJ_NOBJS][3][MAJ_NOBJS]; // variable marks
50 int VarVals[MAJ_NOBJS+2]; // values of the first 2 + nVars variables
51 Vec_Wec_t * vOutLits; // output vars
52 sat_solver * pSat; // SAT solver
53 };
54
Maj_ManTruth(Maj_Man_t * p,int v)55 static inline word * Maj_ManTruth( Maj_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
56
57 ////////////////////////////////////////////////////////////////////////
58 /// FUNCTION DEFINITIONS ///
59 ////////////////////////////////////////////////////////////////////////
60
61 /**Function*************************************************************
62
63 Synopsis []
64
65 Description []
66
67 SideEffects []
68
69 SeeAlso []
70
71 ***********************************************************************/
Maj_ManValue(int iMint,int nVars)72 static int Maj_ManValue( int iMint, int nVars )
73 {
74 int k, Count = 0;
75 for ( k = 0; k < nVars; k++ )
76 Count += (iMint >> k) & 1;
77 return (int)(Count > nVars/2);
78 }
Maj_ManTruthTables(Maj_Man_t * p)79 static Vec_Wrd_t * Maj_ManTruthTables( Maj_Man_t * p )
80 {
81 Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs + 1) );
82 int i, nMints = Abc_MaxInt( 64, 1 << p->nVars );
83 Abc_TtFill( Maj_ManTruth(p, 1), p->nWords );
84 for ( i = 0; i < p->nVars; i++ )
85 Abc_TtIthVar( Maj_ManTruth(p, i+2), i, p->nVars );
86 for ( i = 0; i < nMints; i++ )
87 if ( Maj_ManValue(i, p->nVars) )
88 Abc_TtSetBit( Maj_ManTruth(p, p->nObjs), i );
89 //Dau_DsdPrintFromTruth( Maj_ManTruth(p, p->nObjs), p->nVars );
90 return vInfo;
91 }
Maj_ManConnect(int VarCons[MAJ_NOBJS][3],int nVars,int nObjs,int nRands,int fVerbose)92 static void Maj_ManConnect( int VarCons[MAJ_NOBJS][3], int nVars, int nObjs, int nRands, int fVerbose )
93 {
94 int i, v, r, x;
95 srand(clock());
96 for ( i = nObjs-2; i >= nVars + 2; i-- )
97 {
98 while ( 1 )
99 {
100 int Index = 1 + (rand() % (nObjs-1-i));
101 for ( v = 2; v >= 0; v-- )
102 // for ( v = 0; v < 3; v++ )
103 if ( VarCons[i+Index][v] == 0 )
104 {
105 VarCons[i+Index][v] = i;
106 if ( fVerbose )
107 printf( "%d -> %d ", i, i+Index );
108 break;
109 }
110 if ( v >= 0 )
111 break;
112 }
113 }
114 for ( r = 0; r < nRands; r++ )
115 {
116 i = nVars+2 + (rand() % ((nObjs-1)-(nVars+2)));
117 for ( x = 0; x < 100; x++ )
118 {
119 int Index = 1 + (rand() % (nObjs-1-i));
120 for ( v = 2; v >= 0; v-- )
121 // for ( v = 0; v < 3; v++ )
122 {
123 if ( VarCons[i+Index][v] == i )
124 {
125 v = -1;
126 break;
127 }
128 if ( VarCons[i+Index][v] == 0 )
129 {
130 VarCons[i+Index][v] = i;
131 if ( fVerbose )
132 printf( "+%d -> %d ", i, i+Index );
133 break;
134 }
135 }
136 if ( v >= 0 )
137 break;
138 }
139 if ( x == 100 )
140 r--;
141 }
142 if ( fVerbose )
143 printf( "\n" );
144 }
Maj_ManConnect2(int VarCons[MAJ_NOBJS][3],int nVars,int nObjs,int nRands)145 static void Maj_ManConnect2( int VarCons[MAJ_NOBJS][3], int nVars, int nObjs, int nRands )
146 {
147 VarCons[8+2][2] = 7+2;
148 VarCons[10+2][2] = 9+2;
149 VarCons[11+2][2] = 7+2;
150 VarCons[11+2][1] = 8+2;
151 VarCons[12+2][2] = 9+2;
152 VarCons[12+2][1] = 10+2;
153 VarCons[13+2][2] = 11+2;
154 VarCons[13+2][1] = 12+2;
155 }
Maj_ManMarkup(Maj_Man_t * p)156 static int Maj_ManMarkup( Maj_Man_t * p )
157 {
158 int VarCons[MAJ_NOBJS][3] = {{0}};
159 int i, k, j, m;
160 p->iVar = 1;
161 assert( p->nObjs <= MAJ_NOBJS );
162 // create connections
163 if ( p->fUseRand )
164 Maj_ManConnect( VarCons, p->nVars, p->nObjs, p->nRands, p->fVerbose );
165 // make exception for the first node
166 i = p->nVars + 2;
167 for ( k = 0; k < 3; k++ )
168 {
169 j = 4-k;
170 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
171 p->VarMarks[i][k][j] = p->iVar++;
172 }
173 // assign variables for other nodes
174 for ( i = p->nVars + 3; i < p->nObjs; i++ )
175 {
176 for ( k = 0; k < 3; k++ )
177 {
178 if ( p->fUseLine && k == 0 )
179 {
180 j = i-1;
181 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
182 p->VarMarks[i][k][j] = p->iVar++;
183 continue;
184 }
185 if ( p->fUseRand && VarCons[i][k] > 0 )
186 {
187 j = VarCons[i][k];
188 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
189 p->VarMarks[i][k][j] = p->iVar++;
190 continue;
191 }
192
193 for ( j = (p->fUseConst && k == 2) ? 0 : 2; j < (p->fUseRand ? p->nVars+2-k : i-k); j++ )
194 {
195 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
196 p->VarMarks[i][k][j] = p->iVar++;
197 }
198 }
199 }
200 printf( "The number of parameter variables = %d.\n", p->iVar );
201 if ( !p->fVerbose )
202 return p->iVar;
203 // printout
204 printf( " " );
205 for ( i = p->nVars + 2; i < p->nObjs; i++ )
206 printf( " Node %2d ", i );
207 printf( "\n" );
208 for ( m = 0; m < p->nObjs; m++ )
209 {
210 printf( "%2d : ", m );
211 for ( i = p->nVars + 2; i < p->nObjs; i++ )
212 {
213 for ( j = 0; j < p->nObjs; j++ )
214 {
215 if ( j != m )
216 continue;
217 for ( k = 0; k < 3; k++ )
218 if ( p->VarMarks[i][k][j] )
219 printf( "%3d ", p->VarMarks[i][k][j] );
220 else
221 printf( "%3c ", '.' );
222 printf( " " );
223 }
224 }
225 printf( "\n" );
226 }
227 return p->iVar;
228 }
Maj_ManAlloc(int nVars,int nNodes,int fUseConst,int fUseLine,int fUseRand,int nRands,int fVerbose)229 static Maj_Man_t * Maj_ManAlloc( int nVars, int nNodes, int fUseConst, int fUseLine, int fUseRand, int nRands, int fVerbose )
230 {
231 Maj_Man_t * p = ABC_CALLOC( Maj_Man_t, 1 );
232 p->nVars = nVars;
233 p->nNodes = nNodes;
234 p->nObjs = 2 + nVars + nNodes;
235 p->fUseConst = fUseConst;
236 p->fUseLine = fUseLine;
237 p->fUseRand = fUseRand;
238 p->fVerbose = fVerbose;
239 p->nRands = nRands;
240 p->nWords = Abc_TtWordNum(nVars);
241 p->vOutLits = Vec_WecStart( p->nObjs );
242 p->iVar = Maj_ManMarkup( p );
243 p->VarVals[1] = 1;
244 p->vInfo = Maj_ManTruthTables( p );
245 p->pSat = sat_solver_new();
246 sat_solver_setnvars( p->pSat, p->iVar );
247 return p;
248 }
Maj_ManFree(Maj_Man_t * p)249 static void Maj_ManFree( Maj_Man_t * p )
250 {
251 sat_solver_delete( p->pSat );
252 Vec_WrdFree( p->vInfo );
253 Vec_WecFree( p->vOutLits );
254 ABC_FREE( p );
255 }
256
257
258 /**Function*************************************************************
259
260 Synopsis []
261
262 Description []
263
264 SideEffects []
265
266 SeeAlso []
267
268 ***********************************************************************/
Maj_ManFindFanin(Maj_Man_t * p,int i,int k)269 static inline int Maj_ManFindFanin( Maj_Man_t * p, int i, int k )
270 {
271 int j, Count = 0, iVar = -1;
272 for ( j = 0; j < p->nObjs; j++ )
273 if ( p->VarMarks[i][k][j] && sat_solver_var_value(p->pSat, p->VarMarks[i][k][j]) )
274 {
275 iVar = j;
276 Count++;
277 }
278 assert( Count == 1 );
279 return iVar;
280 }
Maj_ManEval(Maj_Man_t * p)281 static inline int Maj_ManEval( Maj_Man_t * p )
282 {
283 int fUseMiddle = 1;
284 static int Flag = 0;
285 int i, k, iMint; word * pFanins[3];
286 for ( i = p->nVars + 2; i < p->nObjs; i++ )
287 {
288 for ( k = 0; k < 3; k++ )
289 pFanins[k] = Maj_ManTruth( p, Maj_ManFindFanin(p, i, k) );
290 Abc_TtMaj( Maj_ManTruth(p, i), pFanins[0], pFanins[1], pFanins[2], p->nWords );
291 }
292 if ( fUseMiddle )
293 {
294 iMint = -1;
295 for ( i = 0; i < (1 << p->nVars); i++ )
296 {
297 int nOnes = Abc_TtBitCount16(i);
298 if ( nOnes < p->nVars/2 || nOnes > p->nVars/2+1 )
299 continue;
300 if ( Abc_TtGetBit(Maj_ManTruth(p, p->nObjs), i) == Abc_TtGetBit(Maj_ManTruth(p, p->nObjs-1), i) )
301 continue;
302 iMint = i;
303 break;
304 }
305 }
306 else
307 {
308 if ( Flag && p->nVars >= 6 )
309 iMint = Abc_TtFindLastDiffBit( Maj_ManTruth(p, p->nObjs-1), Maj_ManTruth(p, p->nObjs), p->nVars );
310 else
311 iMint = Abc_TtFindFirstDiffBit( Maj_ManTruth(p, p->nObjs-1), Maj_ManTruth(p, p->nObjs), p->nVars );
312 }
313 //Flag ^= 1;
314 assert( iMint < (1 << p->nVars) );
315 return iMint;
316 }
317
318 /**Function*************************************************************
319
320 Synopsis []
321
322 Description []
323
324 SideEffects []
325
326 SeeAlso []
327
328 ***********************************************************************/
Maj_ManPrintSolution(Maj_Man_t * p)329 static void Maj_ManPrintSolution( Maj_Man_t * p )
330 {
331 int i, k, iVar;
332 printf( "Realization of %d-input majority using %d MAJ3 gates:\n", p->nVars, p->nNodes );
333 // for ( i = p->nVars + 2; i < p->nObjs; i++ )
334 for ( i = p->nObjs - 1; i >= p->nVars + 2; i-- )
335 {
336 printf( "%02d = MAJ(", i-2 );
337 for ( k = 2; k >= 0; k-- )
338 {
339 iVar = Maj_ManFindFanin( p, i, k );
340 if ( iVar >= 2 && iVar < p->nVars + 2 )
341 printf( " %c", 'a'+iVar-2 );
342 else if ( iVar < 2 )
343 printf( " %d", iVar );
344 else
345 printf( " %02d", iVar-2 );
346 }
347 printf( " )\n" );
348 }
349 }
350
351
352 /**Function*************************************************************
353
354 Synopsis []
355
356 Description []
357
358 SideEffects []
359
360 SeeAlso []
361
362 ***********************************************************************/
Maj_ManAddCnfStart(Maj_Man_t * p)363 static int Maj_ManAddCnfStart( Maj_Man_t * p )
364 {
365 int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
366 // input constraints
367 for ( i = p->nVars + 2; i < p->nObjs; i++ )
368 {
369 for ( k = 0; k < 3; k++ )
370 {
371 int nLits = 0;
372 for ( j = 0; j < p->nObjs; j++ )
373 if ( p->VarMarks[i][k][j] )
374 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
375 assert( nLits > 0 );
376 // input uniqueness
377 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
378 return 0;
379 for ( n = 0; n < nLits; n++ )
380 for ( m = n+1; m < nLits; m++ )
381 {
382 pLits2[0] = Abc_LitNot(pLits[n]);
383 pLits2[1] = Abc_LitNot(pLits[m]);
384 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
385 return 0;
386 }
387 if ( k == 2 || p->VarMarks[i][k][2] == 0 || p->VarMarks[i][k+1][2] == 0 )
388 continue;
389 // symmetry breaking
390 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
391 for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
392 {
393 pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
394 pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
395 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
396 return 0;
397 }
398 }
399 }
400 // outputs should be used
401 for ( i = 2; i < p->nObjs - 1; i++ )
402 {
403 Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
404 assert( Vec_IntSize(vArray) > 0 );
405 if ( !sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntLimit(vArray) ) )
406 return 0;
407 }
408 return 1;
409 }
Maj_ManAddCnf(Maj_Man_t * p,int iMint)410 static int Maj_ManAddCnf( Maj_Man_t * p, int iMint )
411 {
412 // save minterm values
413 int i, k, n, j, Value = Maj_ManValue(iMint, p->nVars);
414 for ( i = 0; i < p->nVars; i++ )
415 p->VarVals[i+2] = (iMint >> i) & 1;
416 sat_solver_setnvars( p->pSat, p->iVar + 4*p->nNodes );
417 //printf( "Adding clauses for minterm %d.\n", iMint );
418 for ( i = p->nVars + 2; i < p->nObjs; i++ )
419 {
420 // fanin connectivity
421 int iBaseSatVarI = p->iVar + 4*(i - p->nVars - 2);
422 for ( k = 0; k < 3; k++ )
423 {
424 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
425 {
426 int iBaseSatVarJ = p->iVar + 4*(j - p->nVars - 2);
427 for ( n = 0; n < 2; n++ )
428 {
429 int pLits[3], nLits = 0;
430 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
431 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
432 if ( j >= p->nVars + 2 )
433 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + 3, !n );
434 else if ( p->VarVals[j] == n )
435 continue;
436 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
437 return 0;
438 }
439 }
440 }
441 // node functionality
442 for ( n = 0; n < 2; n++ )
443 {
444 if ( i == p->nObjs - 1 && n == Value )
445 continue;
446 for ( k = 0; k < 3; k++ )
447 {
448 int pLits[3], nLits = 0;
449 if ( k != 0 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, n );
450 if ( k != 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, n );
451 if ( k != 2 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, n );
452 if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 3, !n );
453 assert( nLits <= 3 );
454 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
455 return 0;
456 }
457 }
458 }
459 p->iVar += 4*p->nNodes;
460 return 1;
461 }
Maj_ManExactSynthesis2(int nVars,int nNodes,int fUseConst,int fUseLine,int fUseRand,int nRands,int fVerbose)462 int Maj_ManExactSynthesis2( int nVars, int nNodes, int fUseConst, int fUseLine, int fUseRand, int nRands, int fVerbose )
463 {
464 int i, iMint = 0;
465 abctime clkTotal = Abc_Clock();
466 Maj_Man_t * p = Maj_ManAlloc( nVars, nNodes, fUseConst, fUseLine, fUseRand, nRands, fVerbose );
467 int status = Maj_ManAddCnfStart( p );
468 assert( status );
469 if ( fVerbose )
470 printf( "Running exact synthesis for %d-input majority with %d MAJ3 gates...\n", p->nVars, p->nNodes );
471 for ( i = 0; iMint != -1; i++ )
472 {
473 abctime clk = Abc_Clock();
474 if ( !Maj_ManAddCnf( p, iMint ) )
475 {
476 printf( "The problem has no solution after %2d iterations. ", i+1 );
477 break;
478 }
479 status = sat_solver_solve( p->pSat, NULL, NULL, 0, 0, 0, 0 );
480 if ( fVerbose )
481 {
482 printf( "Iter %3d : ", i );
483 Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
484 printf( " Var =%5d ", p->iVar );
485 printf( "Cla =%6d ", sat_solver_nclauses(p->pSat) );
486 printf( "Conf =%9d ", sat_solver_nconflicts(p->pSat) );
487 Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
488 }
489 if ( status == l_False )
490 {
491 printf( "The problem has no solution after %2d iterations. ", i+1 );
492 break;
493 }
494 iMint = Maj_ManEval( p );
495 }
496 if ( iMint == -1 )
497 Maj_ManPrintSolution( p );
498 Maj_ManFree( p );
499 Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
500 return iMint == -1;
501 }
502
Maj_ManExactSynthesisTest()503 int Maj_ManExactSynthesisTest()
504 {
505 // while ( !Maj_ManExactSynthesis2( 5, 4, 0, 0, 1, 1, 0 ) );
506 // while ( !Maj_ManExactSynthesis2( 7, 7, 0, 0, 1, 2, 0 ) );
507 while ( !Maj_ManExactSynthesis2( 9, 10, 0, 0, 1, 3, 0 ) );
508 return 1;
509 }
510
511
512
513
514
515
516 typedef struct Exa_Man_t_ Exa_Man_t;
517 struct Exa_Man_t_
518 {
519 Bmc_EsPar_t * pPars; // parameters
520 int nVars; // inputs
521 int nNodes; // internal nodes
522 int nObjs; // total objects (nVars inputs + nNodes internal nodes)
523 int nWords; // the truth table size in 64-bit words
524 int iVar; // the next available SAT variable
525 word * pTruth; // truth table
526 Vec_Wrd_t * vInfo; // nVars + nNodes + 1
527 int VarMarks[MAJ_NOBJS][2][MAJ_NOBJS]; // variable marks
528 int VarVals[MAJ_NOBJS]; // values of the first nVars variables
529 Vec_Wec_t * vOutLits; // output vars
530 sat_solver * pSat; // SAT solver
531 };
532
Exa_ManTruth(Exa_Man_t * p,int v)533 static inline word * Exa_ManTruth( Exa_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
534
535
536 /**Function*************************************************************
537
538 Synopsis []
539
540 Description []
541
542 SideEffects []
543
544 SeeAlso []
545
546 ***********************************************************************/
Exa_ManTruthTables(Exa_Man_t * p)547 static Vec_Wrd_t * Exa_ManTruthTables( Exa_Man_t * p )
548 {
549 Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs+1) ); int i;
550 for ( i = 0; i < p->nVars; i++ )
551 Abc_TtIthVar( Exa_ManTruth(p, i), i, p->nVars );
552 //Dau_DsdPrintFromTruth( Exa_ManTruth(p, p->nObjs), p->nVars );
553 return vInfo;
554 }
Exa_ManMarkup(Exa_Man_t * p)555 static int Exa_ManMarkup( Exa_Man_t * p )
556 {
557 int i, k, j;
558 assert( p->nObjs <= MAJ_NOBJS );
559 // assign functionality
560 p->iVar = 1 + p->nNodes * 3;
561 // assign connectivity variables
562 for ( i = p->nVars; i < p->nObjs; i++ )
563 {
564 for ( k = 0; k < 2; k++ )
565 {
566 if ( p->pPars->fFewerVars && i == p->nObjs - 1 && k == 0 )
567 {
568 j = p->nObjs - 2;
569 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
570 p->VarMarks[i][k][j] = p->iVar++;
571 continue;
572 }
573 for ( j = p->pPars->fFewerVars ? 1 - k : 0; j < i - k; j++ )
574 {
575 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
576 p->VarMarks[i][k][j] = p->iVar++;
577 }
578 }
579 }
580 printf( "The number of parameter variables = %d.\n", p->iVar );
581 return p->iVar;
582 // printout
583 for ( i = p->nVars; i < p->nObjs; i++ )
584 {
585 printf( "Node %d\n", i );
586 for ( j = 0; j < p->nObjs; j++ )
587 {
588 for ( k = 0; k < 2; k++ )
589 printf( "%3d ", p->VarMarks[i][k][j] );
590 printf( "\n" );
591 }
592 }
593 return p->iVar;
594 }
Exa_ManAlloc(Bmc_EsPar_t * pPars,word * pTruth)595 static Exa_Man_t * Exa_ManAlloc( Bmc_EsPar_t * pPars, word * pTruth )
596 {
597 Exa_Man_t * p = ABC_CALLOC( Exa_Man_t, 1 );
598 p->pPars = pPars;
599 p->nVars = pPars->nVars;
600 p->nNodes = pPars->nNodes;
601 p->nObjs = pPars->nVars + pPars->nNodes;
602 p->nWords = Abc_TtWordNum(pPars->nVars);
603 p->pTruth = pTruth;
604 p->vOutLits = Vec_WecStart( p->nObjs );
605 p->iVar = Exa_ManMarkup( p );
606 p->vInfo = Exa_ManTruthTables( p );
607 p->pSat = sat_solver_new();
608 sat_solver_setnvars( p->pSat, p->iVar );
609 return p;
610 }
Exa_ManFree(Exa_Man_t * p)611 static void Exa_ManFree( Exa_Man_t * p )
612 {
613 sat_solver_delete( p->pSat );
614 Vec_WrdFree( p->vInfo );
615 Vec_WecFree( p->vOutLits );
616 ABC_FREE( p );
617 }
618
619
620 /**Function*************************************************************
621
622 Synopsis []
623
624 Description []
625
626 SideEffects []
627
628 SeeAlso []
629
630 ***********************************************************************/
Exa_ManFindFanin(Exa_Man_t * p,int i,int k)631 static inline int Exa_ManFindFanin( Exa_Man_t * p, int i, int k )
632 {
633 int j, Count = 0, iVar = -1;
634 for ( j = 0; j < p->nObjs; j++ )
635 if ( p->VarMarks[i][k][j] && sat_solver_var_value(p->pSat, p->VarMarks[i][k][j]) )
636 {
637 iVar = j;
638 Count++;
639 }
640 assert( Count == 1 );
641 return iVar;
642 }
Exa_ManEval(Exa_Man_t * p)643 static inline int Exa_ManEval( Exa_Man_t * p )
644 {
645 static int Flag = 0;
646 int i, k, iMint; word * pFanins[2];
647 for ( i = p->nVars; i < p->nObjs; i++ )
648 {
649 int iVarStart = 1 + 3*(i - p->nVars);
650 for ( k = 0; k < 2; k++ )
651 pFanins[k] = Exa_ManTruth( p, Exa_ManFindFanin(p, i, k) );
652 Abc_TtConst0( Exa_ManTruth(p, i), p->nWords );
653 for ( k = 1; k < 4; k++ )
654 {
655 if ( !sat_solver_var_value(p->pSat, iVarStart+k-1) )
656 continue;
657 Abc_TtAndCompl( Exa_ManTruth(p, p->nObjs), pFanins[0], !(k&1), pFanins[1], !(k>>1), p->nWords );
658 Abc_TtOr( Exa_ManTruth(p, i), Exa_ManTruth(p, i), Exa_ManTruth(p, p->nObjs), p->nWords );
659 }
660 }
661 if ( Flag && p->nVars >= 6 )
662 iMint = Abc_TtFindLastDiffBit( Exa_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
663 else
664 iMint = Abc_TtFindFirstDiffBit( Exa_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
665 //Flag ^= 1;
666 assert( iMint < (1 << p->nVars) );
667 return iMint;
668 }
669
670 /**Function*************************************************************
671
672 Synopsis []
673
674 Description []
675
676 SideEffects []
677
678 SeeAlso []
679
680 ***********************************************************************/
Exa_ManPrintSolution(Exa_Man_t * p,int fCompl)681 static void Exa_ManPrintSolution( Exa_Man_t * p, int fCompl )
682 {
683 int i, k, iVar;
684 printf( "Realization of given %d-input function using %d two-input gates:\n", p->nVars, p->nNodes );
685 // for ( i = p->nVars + 2; i < p->nObjs; i++ )
686 for ( i = p->nObjs - 1; i >= p->nVars; i-- )
687 {
688 int iVarStart = 1 + 3*(i - p->nVars);
689 int Val1 = sat_solver_var_value(p->pSat, iVarStart);
690 int Val2 = sat_solver_var_value(p->pSat, iVarStart+1);
691 int Val3 = sat_solver_var_value(p->pSat, iVarStart+2);
692 if ( i == p->nObjs - 1 && fCompl )
693 printf( "%02d = 4\'b%d%d%d1(", i, !Val3, !Val2, !Val1 );
694 else
695 printf( "%02d = 4\'b%d%d%d0(", i, Val3, Val2, Val1 );
696 for ( k = 1; k >= 0; k-- )
697 {
698 iVar = Exa_ManFindFanin( p, i, k );
699 if ( iVar >= 0 && iVar < p->nVars )
700 printf( " %c", 'a'+iVar );
701 else
702 printf( " %02d", iVar );
703 }
704 printf( " )\n" );
705 }
706 }
707
708
709 /**Function*************************************************************
710
711 Synopsis []
712
713 Description []
714
715 SideEffects []
716
717 SeeAlso []
718
719 ***********************************************************************/
Exa_ManAddCnfStart(Exa_Man_t * p,int fOnlyAnd)720 static int Exa_ManAddCnfStart( Exa_Man_t * p, int fOnlyAnd )
721 {
722 int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
723 // input constraints
724 for ( i = p->nVars; i < p->nObjs; i++ )
725 {
726 int iVarStart = 1 + 3*(i - p->nVars);
727 for ( k = 0; k < 2; k++ )
728 {
729 int nLits = 0;
730 for ( j = 0; j < p->nObjs; j++ )
731 if ( p->VarMarks[i][k][j] )
732 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
733 assert( nLits > 0 );
734 // input uniqueness
735 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
736 return 0;
737 for ( n = 0; n < nLits; n++ )
738 for ( m = n+1; m < nLits; m++ )
739 {
740 pLits2[0] = Abc_LitNot(pLits[n]);
741 pLits2[1] = Abc_LitNot(pLits[m]);
742 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
743 return 0;
744 }
745 if ( k == 1 )
746 break;
747 // symmetry breaking
748 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
749 for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
750 {
751 pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
752 pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
753 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
754 return 0;
755 }
756 }
757 #ifdef USE_NODE_ORDER
758 // node ordering
759 for ( j = p->nVars; j < i; j++ )
760 for ( n = 0; n < p->nObjs; n++ ) if ( p->VarMarks[i][0][n] )
761 for ( m = n+1; m < p->nObjs; m++ ) if ( p->VarMarks[j][0][m] )
762 {
763 pLits2[0] = Abc_Var2Lit( p->VarMarks[i][0][n], 1 );
764 pLits2[1] = Abc_Var2Lit( p->VarMarks[j][0][m], 1 );
765 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
766 return 0;
767 }
768 #endif
769 // two input functions
770 for ( k = 0; k < 3; k++ )
771 {
772 pLits[0] = Abc_Var2Lit( iVarStart, k==1 );
773 pLits[1] = Abc_Var2Lit( iVarStart+1, k==2 );
774 pLits[2] = Abc_Var2Lit( iVarStart+2, k!=0 );
775 if ( !sat_solver_addclause( p->pSat, pLits, pLits+3 ) )
776 return 0;
777 }
778 if ( fOnlyAnd )
779 {
780 pLits[0] = Abc_Var2Lit( iVarStart, 1 );
781 pLits[1] = Abc_Var2Lit( iVarStart+1, 1 );
782 pLits[2] = Abc_Var2Lit( iVarStart+2, 0 );
783 if ( !sat_solver_addclause( p->pSat, pLits, pLits+3 ) )
784 return 0;
785 }
786 }
787 // outputs should be used
788 for ( i = 0; i < p->nObjs - 1; i++ )
789 {
790 Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
791 assert( Vec_IntSize(vArray) > 0 );
792 if ( !sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntLimit(vArray) ) )
793 return 0;
794 }
795 return 1;
796 }
Exa_ManAddCnf(Exa_Man_t * p,int iMint)797 static int Exa_ManAddCnf( Exa_Man_t * p, int iMint )
798 {
799 // save minterm values
800 int i, k, n, j, Value = Abc_TtGetBit(p->pTruth, iMint);
801 for ( i = 0; i < p->nVars; i++ )
802 p->VarVals[i] = (iMint >> i) & 1;
803 sat_solver_setnvars( p->pSat, p->iVar + 3*p->nNodes );
804 //printf( "Adding clauses for minterm %d with value %d.\n", iMint, Value );
805 for ( i = p->nVars; i < p->nObjs; i++ )
806 {
807 // fanin connectivity
808 int iVarStart = 1 + 3*(i - p->nVars);
809 int iBaseSatVarI = p->iVar + 3*(i - p->nVars);
810 for ( k = 0; k < 2; k++ )
811 {
812 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
813 {
814 int iBaseSatVarJ = p->iVar + 3*(j - p->nVars);
815 for ( n = 0; n < 2; n++ )
816 {
817 int pLits[3], nLits = 0;
818 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
819 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
820 if ( j >= p->nVars )
821 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + 2, !n );
822 else if ( p->VarVals[j] == n )
823 continue;
824 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
825 return 0;
826 }
827 }
828 }
829 // node functionality
830 for ( n = 0; n < 2; n++ )
831 {
832 if ( i == p->nObjs - 1 && n == Value )
833 continue;
834 for ( k = 0; k < 4; k++ )
835 {
836 int pLits[4], nLits = 0;
837 if ( k == 0 && n == 1 )
838 continue;
839 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, (k&1) );
840 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, (k>>1) );
841 if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, !n );
842 if ( k > 0 ) pLits[nLits++] = Abc_Var2Lit( iVarStart + k-1, n );
843 assert( nLits <= 4 );
844 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
845 return 0;
846 }
847 }
848 }
849 p->iVar += 3*p->nNodes;
850 return 1;
851 }
Exa_ManExactSynthesis2(Bmc_EsPar_t * pPars)852 void Exa_ManExactSynthesis2( Bmc_EsPar_t * pPars )
853 {
854 int i, status, iMint = 1;
855 abctime clkTotal = Abc_Clock();
856 Exa_Man_t * p; int fCompl = 0;
857 word pTruth[16]; Abc_TtReadHex( pTruth, pPars->pTtStr );
858 assert( pPars->nVars <= 10 );
859 p = Exa_ManAlloc( pPars, pTruth );
860 if ( pTruth[0] & 1 ) { fCompl = 1; Abc_TtNot( pTruth, p->nWords ); }
861 status = Exa_ManAddCnfStart( p, pPars->fOnlyAnd );
862 assert( status );
863 printf( "Running exact synthesis for %d-input function with %d two-input gates...\n", p->nVars, p->nNodes );
864 for ( i = 0; iMint != -1; i++ )
865 {
866 abctime clk = Abc_Clock();
867 if ( !Exa_ManAddCnf( p, iMint ) )
868 break;
869 status = sat_solver_solve( p->pSat, NULL, NULL, 0, 0, 0, 0 );
870 if ( pPars->fVerbose )
871 {
872 printf( "Iter %3d : ", i );
873 Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
874 printf( " Var =%5d ", p->iVar );
875 printf( "Cla =%6d ", sat_solver_nclauses(p->pSat) );
876 printf( "Conf =%9d ", sat_solver_nconflicts(p->pSat) );
877 Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
878 }
879 if ( status == l_False )
880 {
881 printf( "The problem has no solution.\n" );
882 break;
883 }
884 iMint = Exa_ManEval( p );
885 }
886 if ( iMint == -1 )
887 Exa_ManPrintSolution( p, fCompl );
888 Exa_ManFree( p );
889 Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
890 }
891
892
893
894
895
896
897 typedef struct Exa3_Man_t_ Exa3_Man_t;
898 struct Exa3_Man_t_
899 {
900 Bmc_EsPar_t * pPars; // parameters
901 int nVars; // inputs
902 int nNodes; // internal nodes
903 int nLutSize; // lut size
904 int LutMask; // lut mask
905 int nObjs; // total objects (nVars inputs + nNodes internal nodes)
906 int nWords; // the truth table size in 64-bit words
907 int iVar; // the next available SAT variable
908 word * pTruth; // truth table
909 Vec_Wrd_t * vInfo; // nVars + nNodes + 1
910 int VarMarks[MAJ_NOBJS][6][MAJ_NOBJS]; // variable marks
911 int VarVals[MAJ_NOBJS]; // values of the first nVars variables
912 Vec_Wec_t * vOutLits; // output vars
913 sat_solver * pSat; // SAT solver
914 };
915
Exa3_ManTruth(Exa3_Man_t * p,int v)916 static inline word * Exa3_ManTruth( Exa3_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
917
918
919 /**Function*************************************************************
920
921 Synopsis []
922
923 Description []
924
925 SideEffects []
926
927 SeeAlso []
928
929 ***********************************************************************/
Exa3_ManTruthTables(Exa3_Man_t * p)930 static Vec_Wrd_t * Exa3_ManTruthTables( Exa3_Man_t * p )
931 {
932 Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs+1) ); int i;
933 for ( i = 0; i < p->nVars; i++ )
934 Abc_TtIthVar( Exa3_ManTruth(p, i), i, p->nVars );
935 //Dau_DsdPrintFromTruth( Exa3_ManTruth(p, p->nObjs), p->nVars );
936 return vInfo;
937 }
Exa3_ManMarkup(Exa3_Man_t * p)938 static int Exa3_ManMarkup( Exa3_Man_t * p )
939 {
940 int i, k, j;
941 assert( p->nObjs <= MAJ_NOBJS );
942 // assign functionality variables
943 p->iVar = 1 + p->LutMask * p->nNodes;
944 // assign connectivity variables
945 for ( i = p->nVars; i < p->nObjs; i++ )
946 {
947 for ( k = 0; k < p->nLutSize; k++ )
948 {
949 if ( p->pPars->fFewerVars && i == p->nObjs - 1 && k == 0 )
950 {
951 j = p->nObjs - 2;
952 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
953 p->VarMarks[i][k][j] = p->iVar++;
954 continue;
955 }
956 for ( j = p->pPars->fFewerVars ? p->nLutSize - 1 - k : 0; j < i - k; j++ )
957 {
958 Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
959 p->VarMarks[i][k][j] = p->iVar++;
960 }
961 }
962 }
963 printf( "The number of parameter variables = %d.\n", p->iVar );
964 return p->iVar;
965 // printout
966 // for ( i = p->nVars; i < p->nObjs; i++ )
967 for ( i = p->nObjs - 1; i >= p->nVars; i-- )
968 {
969 printf( " Node %2d\n", i );
970 for ( j = 0; j < p->nObjs; j++ )
971 {
972 printf( "Fanin %2d : ", j );
973 for ( k = 0; k < p->nLutSize; k++ )
974 printf( "%3d ", p->VarMarks[i][k][j] );
975 printf( "\n" );
976 }
977 }
978 return p->iVar;
979 }
Exa3_ManInitPolarityFindVar(Exa3_Man_t * p,int i,int k,int * pIndex)980 static int Exa3_ManInitPolarityFindVar( Exa3_Man_t * p, int i, int k, int * pIndex )
981 {
982 int iVar;
983 do {
984 iVar = p->VarMarks[i][k][*pIndex];
985 *pIndex = (*pIndex + 1) % p->nVars;
986 } while ( iVar <= 0 );
987 //intf( "Setting var %d.\n", iVar );
988 return iVar;
989 }
Exa3_ManInitPolarity(Exa3_Man_t * p)990 static void Exa3_ManInitPolarity( Exa3_Man_t * p )
991 {
992 int i, k, iVar, nInputs = 0;
993 for ( i = p->nVars; i < p->nObjs; i++ )
994 {
995 // create AND-gate
996 int iVarStart = 1 + p->LutMask*(i - p->nVars);
997 iVar = iVarStart + p->LutMask-1;
998 p->pSat->polarity[iVar] = 1;
999 //printf( "Setting var %d.\n", iVar );
1000 }
1001 for ( i = p->nVars; i < p->nObjs; i++ )
1002 {
1003 // connect first fanin to previous
1004 if ( i == p->nVars )
1005 {
1006 for ( k = p->nLutSize - 1; k >= 0; k-- )
1007 {
1008 iVar = Exa3_ManInitPolarityFindVar( p, i, k, &nInputs );
1009 p->pSat->polarity[iVar] = 1;
1010 }
1011 }
1012 else
1013 {
1014 for ( k = p->nLutSize - 1; k > 0; k-- )
1015 {
1016 iVar = Exa3_ManInitPolarityFindVar( p, i, k, &nInputs );
1017 p->pSat->polarity[iVar] = 1;
1018 }
1019 iVar = p->VarMarks[i][0][i-1];
1020 if ( iVar <= 0 ) printf( "Variable mapping error.\n" ), fflush(stdout);
1021 assert( iVar > 0 );
1022 p->pSat->polarity[iVar] = 1;
1023 //intf( "Setting var %d.\n", iVar );
1024 }
1025 //intf( "\n" );
1026 }
1027 }
Exa3_ManAlloc(Bmc_EsPar_t * pPars,word * pTruth)1028 static Exa3_Man_t * Exa3_ManAlloc( Bmc_EsPar_t * pPars, word * pTruth )
1029 {
1030 Exa3_Man_t * p = ABC_CALLOC( Exa3_Man_t, 1 );
1031 p->pPars = pPars;
1032 p->nVars = pPars->nVars;
1033 p->nNodes = pPars->nNodes;
1034 p->nLutSize = pPars->nLutSize;
1035 p->LutMask = (1 << pPars->nLutSize) - 1;
1036 p->nObjs = pPars->nVars + pPars->nNodes;
1037 p->nWords = Abc_TtWordNum(pPars->nVars);
1038 p->pTruth = pTruth;
1039 p->vOutLits = Vec_WecStart( p->nObjs );
1040 p->iVar = Exa3_ManMarkup( p );
1041 p->vInfo = Exa3_ManTruthTables( p );
1042 p->pSat = sat_solver_new();
1043 sat_solver_setnvars( p->pSat, p->iVar );
1044 //Exa3_ManInitPolarity( p );
1045 return p;
1046 }
Exa3_ManFree(Exa3_Man_t * p)1047 static void Exa3_ManFree( Exa3_Man_t * p )
1048 {
1049 sat_solver_delete( p->pSat );
1050 Vec_WrdFree( p->vInfo );
1051 Vec_WecFree( p->vOutLits );
1052 ABC_FREE( p );
1053 }
1054
1055
1056 /**Function*************************************************************
1057
1058 Synopsis []
1059
1060 Description []
1061
1062 SideEffects []
1063
1064 SeeAlso []
1065
1066 ***********************************************************************/
Exa3_ManFindFanin(Exa3_Man_t * p,int i,int k)1067 static inline int Exa3_ManFindFanin( Exa3_Man_t * p, int i, int k )
1068 {
1069 int j, Count = 0, iVar = -1;
1070 for ( j = 0; j < p->nObjs; j++ )
1071 if ( p->VarMarks[i][k][j] && sat_solver_var_value(p->pSat, p->VarMarks[i][k][j]) )
1072 {
1073 iVar = j;
1074 Count++;
1075 }
1076 assert( Count == 1 );
1077 return iVar;
1078 }
Exa3_ManEval(Exa3_Man_t * p)1079 static inline int Exa3_ManEval( Exa3_Man_t * p )
1080 {
1081 static int Flag = 0;
1082 int i, k, j, iMint; word * pFanins[6];
1083 for ( i = p->nVars; i < p->nObjs; i++ )
1084 {
1085 int iVarStart = 1 + p->LutMask*(i - p->nVars);
1086 for ( k = 0; k < p->nLutSize; k++ )
1087 pFanins[k] = Exa3_ManTruth( p, Exa3_ManFindFanin(p, i, k) );
1088 Abc_TtConst0( Exa3_ManTruth(p, i), p->nWords );
1089 for ( k = 1; k <= p->LutMask; k++ )
1090 {
1091 if ( !sat_solver_var_value(p->pSat, iVarStart+k-1) )
1092 continue;
1093 // Abc_TtAndCompl( Exa3_ManTruth(p, p->nObjs), pFanins[0], !(k&1), pFanins[1], !(k>>1), p->nWords );
1094 Abc_TtConst1( Exa3_ManTruth(p, p->nObjs), p->nWords );
1095 for ( j = 0; j < p->nLutSize; j++ )
1096 Abc_TtAndCompl( Exa3_ManTruth(p, p->nObjs), Exa3_ManTruth(p, p->nObjs), 0, pFanins[j], !((k >> j) & 1), p->nWords );
1097 Abc_TtOr( Exa3_ManTruth(p, i), Exa3_ManTruth(p, i), Exa3_ManTruth(p, p->nObjs), p->nWords );
1098 }
1099 }
1100 if ( Flag && p->nVars >= 6 )
1101 iMint = Abc_TtFindLastDiffBit( Exa3_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
1102 else
1103 iMint = Abc_TtFindFirstDiffBit( Exa3_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
1104 //Flag ^= 1;
1105 assert( iMint < (1 << p->nVars) );
1106 return iMint;
1107 }
1108
1109 /**Function*************************************************************
1110
1111 Synopsis []
1112
1113 Description []
1114
1115 SideEffects []
1116
1117 SeeAlso []
1118
1119 ***********************************************************************/
Exa3_ManPrintSolution(Exa3_Man_t * p,int fCompl)1120 static void Exa3_ManPrintSolution( Exa3_Man_t * p, int fCompl )
1121 {
1122 int i, k, iVar;
1123 printf( "Realization of given %d-input function using %d %d-input LUTs:\n", p->nVars, p->nNodes, p->nLutSize );
1124 for ( i = p->nObjs - 1; i >= p->nVars; i-- )
1125 {
1126 int Val, iVarStart = 1 + p->LutMask*(i - p->nVars);
1127
1128 // int Val1 = sat_solver_var_value(p->pSat, iVarStart);
1129 // int Val2 = sat_solver_var_value(p->pSat, iVarStart+1);
1130 // int Val3 = sat_solver_var_value(p->pSat, iVarStart+2);
1131 // if ( i == p->nObjs - 1 && fCompl )
1132 // printf( "%02d = 4\'b%d%d%d1(", i, !Val3, !Val2, !Val1 );
1133 // else
1134 // printf( "%02d = 4\'b%d%d%d0(", i, Val3, Val2, Val1 );
1135
1136 printf( "%02d = %d\'b", i, 1 << p->nLutSize );
1137 for ( k = p->LutMask - 1; k >= 0; k-- )
1138 {
1139 Val = sat_solver_var_value(p->pSat, iVarStart+k);
1140 if ( i == p->nObjs - 1 && fCompl )
1141 printf( "%d", !Val );
1142 else
1143 printf( "%d", Val );
1144 }
1145 if ( i == p->nObjs - 1 && fCompl )
1146 printf( "1(" );
1147 else
1148 printf( "0(" );
1149
1150 for ( k = p->nLutSize - 1; k >= 0; k-- )
1151 {
1152 iVar = Exa3_ManFindFanin( p, i, k );
1153 if ( iVar >= 0 && iVar < p->nVars )
1154 printf( " %c", 'a'+iVar );
1155 else
1156 printf( " %02d", iVar );
1157 }
1158 printf( " )\n" );
1159 }
1160 }
1161
1162
1163 /**Function*************************************************************
1164
1165 Synopsis []
1166
1167 Description []
1168
1169 SideEffects []
1170
1171 SeeAlso []
1172
1173 ***********************************************************************/
Exa3_ManAddCnfStart(Exa3_Man_t * p,int fOnlyAnd)1174 static int Exa3_ManAddCnfStart( Exa3_Man_t * p, int fOnlyAnd )
1175 {
1176 int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
1177 // input constraints
1178 for ( i = p->nVars; i < p->nObjs; i++ )
1179 {
1180 int iVarStart = 1 + p->LutMask*(i - p->nVars);
1181 for ( k = 0; k < p->nLutSize; k++ )
1182 {
1183 int nLits = 0;
1184 for ( j = 0; j < p->nObjs; j++ )
1185 if ( p->VarMarks[i][k][j] )
1186 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
1187 assert( nLits > 0 );
1188 // input uniqueness
1189 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
1190 return 0;
1191 for ( n = 0; n < nLits; n++ )
1192 for ( m = n+1; m < nLits; m++ )
1193 {
1194 pLits2[0] = Abc_LitNot(pLits[n]);
1195 pLits2[1] = Abc_LitNot(pLits[m]);
1196 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
1197 return 0;
1198 }
1199 if ( k == p->nLutSize - 1 )
1200 break;
1201 // symmetry breaking
1202 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
1203 for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
1204 {
1205 pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
1206 pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
1207 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
1208 return 0;
1209 }
1210 }
1211 //printf( "Node %d:\n", i );
1212 //sat_solver_flip_print_clause( p->pSat );
1213 #ifdef USE_NODE_ORDER
1214 // node ordering
1215 for ( j = p->nVars; j < i; j++ )
1216 for ( n = 0; n < p->nObjs; n++ ) if ( p->VarMarks[i][0][n] )
1217 for ( m = n+1; m < p->nObjs; m++ ) if ( p->VarMarks[j][0][m] )
1218 {
1219 pLits2[0] = Abc_Var2Lit( p->VarMarks[i][0][n], 1 );
1220 pLits2[1] = Abc_Var2Lit( p->VarMarks[j][0][m], 1 );
1221 if ( !sat_solver_addclause( p->pSat, pLits2, pLits2+2 ) )
1222 return 0;
1223 }
1224 #endif
1225 if ( p->nLutSize != 2 )
1226 continue;
1227 // two-input functions
1228 for ( k = 0; k < 3; k++ )
1229 {
1230 pLits[0] = Abc_Var2Lit( iVarStart, k==1 );
1231 pLits[1] = Abc_Var2Lit( iVarStart+1, k==2 );
1232 pLits[2] = Abc_Var2Lit( iVarStart+2, k!=0 );
1233 if ( !sat_solver_addclause( p->pSat, pLits, pLits+3 ) )
1234 return 0;
1235 }
1236 if ( fOnlyAnd )
1237 {
1238 pLits[0] = Abc_Var2Lit( iVarStart, 1 );
1239 pLits[1] = Abc_Var2Lit( iVarStart+1, 1 );
1240 pLits[2] = Abc_Var2Lit( iVarStart+2, 0 );
1241 if ( !sat_solver_addclause( p->pSat, pLits, pLits+3 ) )
1242 return 0;
1243 }
1244 }
1245 // outputs should be used
1246 for ( i = 0; i < p->nObjs - 1; i++ )
1247 {
1248 Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
1249 assert( Vec_IntSize(vArray) > 0 );
1250 if ( !sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntLimit(vArray) ) )
1251 return 0;
1252 }
1253 return 1;
1254 }
Exa3_ManAddCnf(Exa3_Man_t * p,int iMint)1255 static int Exa3_ManAddCnf( Exa3_Man_t * p, int iMint )
1256 {
1257 // save minterm values
1258 int i, k, n, j, Value = Abc_TtGetBit(p->pTruth, iMint);
1259 for ( i = 0; i < p->nVars; i++ )
1260 p->VarVals[i] = (iMint >> i) & 1;
1261 sat_solver_setnvars( p->pSat, p->iVar + (p->nLutSize+1)*p->nNodes );
1262 //printf( "Adding clauses for minterm %d with value %d.\n", iMint, Value );
1263 for ( i = p->nVars; i < p->nObjs; i++ )
1264 {
1265 // fanin connectivity
1266 int iVarStart = 1 + p->LutMask*(i - p->nVars);
1267 int iBaseSatVarI = p->iVar + (p->nLutSize+1)*(i - p->nVars);
1268 for ( k = 0; k < p->nLutSize; k++ )
1269 {
1270 for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
1271 {
1272 int iBaseSatVarJ = p->iVar + (p->nLutSize+1)*(j - p->nVars);
1273 for ( n = 0; n < 2; n++ )
1274 {
1275 int pLits[3], nLits = 0;
1276 pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
1277 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
1278 if ( j >= p->nVars )
1279 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + p->nLutSize, !n );
1280 else if ( p->VarVals[j] == n )
1281 continue;
1282 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
1283 return 0;
1284 }
1285 }
1286 }
1287 // node functionality
1288 for ( n = 0; n < 2; n++ )
1289 {
1290 if ( i == p->nObjs - 1 && n == Value )
1291 continue;
1292 for ( k = 0; k <= p->LutMask; k++ )
1293 {
1294 int pLits[8], nLits = 0;
1295 if ( k == 0 && n == 1 )
1296 continue;
1297 //pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, (k&1) );
1298 //pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, (k>>1) );
1299 //if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, !n );
1300 for ( j = 0; j < p->nLutSize; j++ )
1301 pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + j, (k >> j) & 1 );
1302 if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + j, !n );
1303 if ( k > 0 ) pLits[nLits++] = Abc_Var2Lit( iVarStart + k-1, n );
1304 assert( nLits <= p->nLutSize+2 );
1305 if ( !sat_solver_addclause( p->pSat, pLits, pLits+nLits ) )
1306 return 0;
1307 }
1308 }
1309 }
1310 p->iVar += (p->nLutSize+1)*p->nNodes;
1311 return 1;
1312 }
Exa3_ManExactSynthesis2(Bmc_EsPar_t * pPars)1313 void Exa3_ManExactSynthesis2( Bmc_EsPar_t * pPars )
1314 {
1315 int i, status, iMint = 1;
1316 abctime clkTotal = Abc_Clock();
1317 Exa3_Man_t * p; int fCompl = 0;
1318 word pTruth[16]; Abc_TtReadHex( pTruth, pPars->pTtStr );
1319 assert( pPars->nVars <= 10 );
1320 assert( pPars->nLutSize <= 6 );
1321 p = Exa3_ManAlloc( pPars, pTruth );
1322 if ( pTruth[0] & 1 ) { fCompl = 1; Abc_TtNot( pTruth, p->nWords ); }
1323 status = Exa3_ManAddCnfStart( p, pPars->fOnlyAnd );
1324 assert( status );
1325 printf( "Running exact synthesis for %d-input function with %d %d-input LUTs...\n", p->nVars, p->nNodes, p->nLutSize );
1326 for ( i = 0; iMint != -1; i++ )
1327 {
1328 abctime clk = Abc_Clock();
1329 if ( !Exa3_ManAddCnf( p, iMint ) )
1330 break;
1331 status = sat_solver_solve( p->pSat, NULL, NULL, 0, 0, 0, 0 );
1332 if ( pPars->fVerbose )
1333 {
1334 printf( "Iter %3d : ", i );
1335 Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
1336 printf( " Var =%5d ", p->iVar );
1337 printf( "Cla =%6d ", sat_solver_nclauses(p->pSat) );
1338 printf( "Conf =%9d ", sat_solver_nconflicts(p->pSat) );
1339 Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
1340 }
1341 if ( status == l_False )
1342 {
1343 printf( "The problem has no solution.\n" );
1344 break;
1345 }
1346 iMint = Exa3_ManEval( p );
1347 }
1348 if ( iMint == -1 )
1349 Exa3_ManPrintSolution( p, fCompl );
1350 Exa3_ManFree( p );
1351 Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
1352 }
1353
1354
1355 ////////////////////////////////////////////////////////////////////////
1356 /// END OF FILE ///
1357 ////////////////////////////////////////////////////////////////////////
1358
1359
1360 ABC_NAMESPACE_IMPL_END
1361
1362