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
|
/**CFile****************************************************************
FileName [sfmSat.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [SAT-based optimization using internal don't-cares.]
Synopsis [SAT-based procedures.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: sfmSat.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "sfmInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static word s_Truths6[6] = {
ABC_CONST(0xAAAAAAAAAAAAAAAA),
ABC_CONST(0xCCCCCCCCCCCCCCCC),
ABC_CONST(0xF0F0F0F0F0F0F0F0),
ABC_CONST(0xFF00FF00FF00FF00),
ABC_CONST(0xFFFF0000FFFF0000),
ABC_CONST(0xFFFFFFFF00000000)
};
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Converts a window into a SAT solver.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Sfm_NtkWindowToSolver( Sfm_Ntk_t * p )
{
// p->vOrder contains all variables in the window in a good order
// p->vDivs is a subset of nodes in p->vOrder used as divisor candidates
// p->vTfo contains TFO of the node (does not include node)
// p->vRoots contains roots of the TFO of the node (may include node)
Vec_Int_t * vClause;
int RetValue, iNode = -1, iFanin, i, k;
abctime clk = Abc_Clock();
// if ( p->pSat )
// printf( "%d ", p->pSat->stats.learnts );
sat_solver_restart( p->pSat );
sat_solver_setnvars( p->pSat, 1 + Vec_IntSize(p->vOrder) + Vec_IntSize(p->vTfo) + Vec_IntSize(p->vRoots) + 10 );
// create SAT variables
Sfm_NtkCleanVars( p );
p->nSatVars = 1;
Vec_IntForEachEntry( p->vOrder, iNode, i )
Sfm_ObjSetSatVar( p, iNode, p->nSatVars++ );
// collect divisor variables
Vec_IntClear( p->vDivVars );
Vec_IntForEachEntry( p->vDivs, iNode, i )
Vec_IntPush( p->vDivVars, Sfm_ObjSatVar(p, iNode) );
// add CNF clauses for the TFI
Vec_IntForEachEntry( p->vOrder, iNode, i )
{
if ( Sfm_ObjIsPi(p, iNode) )
continue;
// collect fanin variables
Vec_IntClear( p->vFaninMap );
Sfm_ObjForEachFanin( p, iNode, iFanin, k )
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iFanin) );
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iNode) );
// generate CNF
Sfm_TranslateCnf( p->vClauses, (Vec_Str_t *)Vec_WecEntry(p->vCnfs, iNode), p->vFaninMap, -1 );
// add clauses
Vec_WecForEachLevel( p->vClauses, vClause, k )
{
if ( Vec_IntSize(vClause) == 0 )
break;
RetValue = sat_solver_addclause( p->pSat, Vec_IntArray(vClause), Vec_IntArray(vClause) + Vec_IntSize(vClause) );
assert( RetValue );
}
}
if ( Vec_IntSize(p->vTfo) > 0 )
{
assert( p->pPars->nTfoLevMax > 0 );
assert( Vec_IntSize(p->vRoots) > 0 );
assert( Vec_IntEntry(p->vTfo, 0) != p->iPivotNode );
// collect variables of root nodes
Vec_IntClear( p->vLits );
Vec_IntForEachEntry( p->vRoots, iNode, i )
Vec_IntPush( p->vLits, Sfm_ObjSatVar(p, iNode) );
// assign new variables to the TFO nodes
Vec_IntForEachEntry( p->vTfo, iNode, i )
{
Sfm_ObjCleanSatVar( p, Sfm_ObjSatVar(p, iNode) );
Sfm_ObjSetSatVar( p, iNode, p->nSatVars++ );
}
// add CNF clauses for the TFO
Vec_IntForEachEntry( p->vTfo, iNode, i )
{
assert( Sfm_ObjIsNode(p, iNode) );
// collect fanin variables
Vec_IntClear( p->vFaninMap );
Sfm_ObjForEachFanin( p, iNode, iFanin, k )
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iFanin) );
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iNode) );
// generate CNF
Sfm_TranslateCnf( p->vClauses, (Vec_Str_t *)Vec_WecEntry(p->vCnfs, iNode), p->vFaninMap, Sfm_ObjSatVar(p, p->iPivotNode) );
// add clauses
Vec_WecForEachLevel( p->vClauses, vClause, k )
{
if ( Vec_IntSize(vClause) == 0 )
break;
RetValue = sat_solver_addclause( p->pSat, Vec_IntArray(vClause), Vec_IntArray(vClause) + Vec_IntSize(vClause) );
assert( RetValue );
}
}
// create XOR clauses for the roots
Vec_IntForEachEntry( p->vRoots, iNode, i )
{
sat_solver_add_xor( p->pSat, Vec_IntEntry(p->vLits, i), Sfm_ObjSatVar(p, iNode), p->nSatVars++, 0 );
Vec_IntWriteEntry( p->vLits, i, Abc_Var2Lit(p->nSatVars-1, 0) );
}
// make OR clause for the last nRoots variables
RetValue = sat_solver_addclause( p->pSat, Vec_IntArray(p->vLits), Vec_IntArray(p->vLits) + Vec_IntSize(p->vLits) );
if ( RetValue == 0 )
return 0;
}
// finalize
RetValue = sat_solver_simplify( p->pSat );
p->timeCnf += Abc_Clock() - clk;
return RetValue;
}
/**Function*************************************************************
Synopsis [Takes SAT solver and returns interpolant.]
Description [If interpolant does not exist, records difference variables.]
SideEffects []
SeeAlso []
***********************************************************************/
word Sfm_ComputeInterpolant( Sfm_Ntk_t * p )
{
word * pSign, uCube, uTruth = 0;
int status, i, Div, iVar, nFinal, * pFinal, nIter = 0;
int pLits[2], nVars = sat_solver_nvars( p->pSat );
sat_solver_setnvars( p->pSat, nVars + 1 );
pLits[0] = Abc_Var2Lit( Sfm_ObjSatVar(p, p->iPivotNode), 0 ); // F = 1
pLits[1] = Abc_Var2Lit( nVars, 0 ); // iNewLit
while ( 1 )
{
// find onset minterm
p->nSatCalls++;
status = sat_solver_solve( p->pSat, pLits, pLits + 2, p->pPars->nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_False )
return uTruth;
assert( status == l_True );
// remember variable values
Vec_IntClear( p->vValues );
Vec_IntForEachEntry( p->vDivVars, iVar, i )
Vec_IntPush( p->vValues, sat_solver_var_value(p->pSat, iVar) );
// collect divisor literals
Vec_IntClear( p->vLits );
Vec_IntPush( p->vLits, Abc_LitNot(pLits[0]) ); // F = 0
Vec_IntForEachEntry( p->vDivIds, Div, i )
Vec_IntPush( p->vLits, sat_solver_var_literal(p->pSat, Div) );
// check against offset
p->nSatCalls++;
status = sat_solver_solve( p->pSat, Vec_IntArray(p->vLits), Vec_IntArray(p->vLits) + Vec_IntSize(p->vLits), p->pPars->nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_True )
break;
assert( status == l_False );
// compute cube and add clause
nFinal = sat_solver_final( p->pSat, &pFinal );
uCube = ~(word)0;
Vec_IntClear( p->vLits );
Vec_IntPush( p->vLits, Abc_LitNot(pLits[1]) ); // NOT(iNewLit)
for ( i = 0; i < nFinal; i++ )
{
if ( pFinal[i] == pLits[0] )
continue;
Vec_IntPush( p->vLits, pFinal[i] );
iVar = Vec_IntFind( p->vDivIds, Abc_Lit2Var(pFinal[i]) ); assert( iVar >= 0 );
uCube &= Abc_LitIsCompl(pFinal[i]) ? s_Truths6[iVar] : ~s_Truths6[iVar];
}
uTruth |= uCube;
status = sat_solver_addclause( p->pSat, Vec_IntArray(p->vLits), Vec_IntArray(p->vLits) + Vec_IntSize(p->vLits) );
assert( status );
nIter++;
}
assert( status == l_True );
// store the counter-example
Vec_IntForEachEntry( p->vDivVars, iVar, i )
if ( Vec_IntEntry(p->vValues, i) ^ sat_solver_var_value(p->pSat, iVar) ) // insert 1
{
pSign = Vec_WrdEntryP( p->vDivCexes, i );
assert( !Abc_InfoHasBit( (unsigned *)pSign, p->nCexes) );
Abc_InfoXorBit( (unsigned *)pSign, p->nCexes );
}
p->nCexes++;
return SFM_SAT_SAT;
}
/**Function*************************************************************
Synopsis [Checks resubstitution.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Sfm_ComputeInterpolantCheck( Sfm_Ntk_t * p )
{
int iNode = 3;
int iDiv0 = 6;
int iDiv1 = 7;
word uTruth;
// int i;
// Sfm_NtkForEachNode( p, i )
{
Sfm_NtkCreateWindow( p, iNode, 1 );
Sfm_NtkWindowToSolver( p );
// collect SAT variables of divisors
Vec_IntClear( p->vDivIds );
Vec_IntPush( p->vDivIds, Sfm_ObjSatVar(p, iDiv0) );
Vec_IntPush( p->vDivIds, Sfm_ObjSatVar(p, iDiv1) );
uTruth = Sfm_ComputeInterpolant( p );
if ( uTruth == SFM_SAT_SAT )
printf( "The problem is SAT.\n" );
else if ( uTruth == SFM_SAT_UNDEC )
printf( "The problem is UNDEC.\n" );
else
Kit_DsdPrintFromTruth( (unsigned *)&uTruth, 2 ); printf( "\n" );
}
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
