summaryrefslogtreecommitdiffstats
path: root/src/aig/gia/giaFront.c
blob: 1d543a8184cd8a9deba5c389bfff41242e87f0bb (plain)
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
/**CFile****************************************************************

  FileName    [giaFront.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Scalable AIG package.]

  Synopsis    [Frontier representation.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

  Revision    [$Id: giaFront.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

***********************************************************************/

#include "gia.h"

ABC_NAMESPACE_IMPL_START


////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Find the next place on the frontier.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
static inline int Gia_ManFrontFindNext( char * pFront, int nFront, int iFront )
{
    assert( iFront < nFront );
    for ( ; pFront[iFront]; iFront = (iFront + 1) % nFront );
    assert( pFront[iFront] == 0 );
    pFront[iFront] = 1;
    return iFront;
}

/**Function*************************************************************

  Synopsis    [Transforms the frontier manager to its initial state.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManFrontTransform( Gia_Man_t * p )
{
    Gia_Obj_t * pObj;
    int i, * pFrontToId; // mapping of nodes into frontier variables
    assert( p->nFront > 0 );
    pFrontToId = ABC_FALLOC( int, p->nFront );
    Gia_ManForEachObj( p, pObj, i )
    {
        if ( Gia_ObjIsCo(pObj) )
        {
            assert( pObj->Value == GIA_NONE );
            pObj->iDiff0 = i - pFrontToId[Gia_ObjDiff0(pObj)];
        }
        else if ( Gia_ObjIsAnd(pObj) )
        {
            assert( (int)pObj->Value < p->nFront );
            pObj->iDiff0 = i - pFrontToId[Gia_ObjDiff0(pObj)];
            pObj->iDiff1 = i - pFrontToId[Gia_ObjDiff1(pObj)];
            pFrontToId[pObj->Value] = i;
        }
        else
        {
            assert( (int)pObj->Value < p->nFront );
            pFrontToId[pObj->Value] = i;
        }
        pObj->Value = 0;
    }
    ABC_FREE( pFrontToId );
}

/**Function*************************************************************

  Synopsis    [Determine the frontier.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Gia_Man_t * Gia_ManFront( Gia_Man_t * p )
{
    Gia_Man_t * pNew;
    Gia_Obj_t * pObj, * pFanin0New, * pFanin1New, * pObjNew;
    char * pFront;    // places used for the frontier
    int i, iLit, nCrossCut = 0, nCrossCutMax = 0;
    int nCrossCutMaxInit = Gia_ManCrossCut( p );
    int iFront = 0;//, clk = clock(); 
    // set references for all objects
    Gia_ManSetRefs( p );
    // start the new manager
    pNew = Gia_ManStart( Gia_ManObjNum(p) );
    pNew->pName = Abc_UtilStrsav( p->pName );
    pNew->nFront = 1 + (int)((float)1.1 * nCrossCutMaxInit); 
    // start the frontier
    pFront = ABC_CALLOC( char, pNew->nFront );
    // add constant node
    Gia_ManConst0(pNew)->Value = iFront = Gia_ManFrontFindNext( pFront, pNew->nFront, iFront );
    if ( Gia_ObjValue(Gia_ManConst0(p)) == 0 )
        pFront[iFront] = 0;
    else
        nCrossCut = 1;
    // iterate through the objects
    Gia_ManForEachObj1( p, pObj, i )
    {
        if ( Gia_ObjIsCi(pObj) )
        {
            if ( Gia_ObjValue(pObj) && nCrossCutMax < ++nCrossCut )
                nCrossCutMax = nCrossCut;
            // create new node
            iLit = Gia_ManAppendCi( pNew );
            pObjNew = Gia_ManObj( pNew, Abc_Lit2Var(iLit) );
            assert( Gia_ObjId(pNew, pObjNew) == Gia_ObjId(p, pObj) );
            pObjNew->Value = iFront = Gia_ManFrontFindNext( pFront, pNew->nFront, iFront );
            // handle CIs without fanout
            if ( Gia_ObjValue(pObj) == 0 )
                pFront[iFront] = 0;
            continue;
        }
        if ( Gia_ObjIsCo(pObj) )
        {
            assert( Gia_ObjValue(pObj) == 0 );
            // create new node
            iLit = Gia_ManAppendCo( pNew, 0 );
            pObjNew = Gia_ManObj( pNew, Abc_Lit2Var(iLit) );
            assert( Gia_ObjId(pNew, pObjNew) == Gia_ObjId(p, pObj) );
            // get the fanin
            pFanin0New = Gia_ManObj( pNew, Gia_ObjFaninId0(pObj, i) );
            assert( pFanin0New->Value != GIA_NONE );
            pObjNew->Value = GIA_NONE;
            pObjNew->iDiff0 = pFanin0New->Value;
            pObjNew->fCompl0 = Gia_ObjFaninC0(pObj);
            // deref the fanin
            if ( --Gia_ObjFanin0(pObj)->Value == 0 )
            {
                pFront[pFanin0New->Value] = 0;
                nCrossCut--;
            }
            continue;
        }
        if ( Gia_ObjValue(pObj) && nCrossCutMax < ++nCrossCut )
            nCrossCutMax = nCrossCut;
        // create new node
        pObjNew = Gia_ManAppendObj( pNew );
        assert( Gia_ObjId(pNew, pObjNew) == Gia_ObjId(p, pObj) );
        // assign the first fanin
        pFanin0New = Gia_ManObj( pNew, Gia_ObjFaninId0(pObj, i) );
        assert( pFanin0New->Value != GIA_NONE );
        pObjNew->iDiff0 = pFanin0New->Value;
        pObjNew->fCompl0 = Gia_ObjFaninC0(pObj);
        // assign the second fanin
        pFanin1New = Gia_ManObj( pNew, Gia_ObjFaninId1(pObj, i) );
        assert( pFanin1New->Value != GIA_NONE );
        pObjNew->iDiff1 = pFanin1New->Value;
        pObjNew->fCompl1 = Gia_ObjFaninC1(pObj);
        // assign the frontier number
        pObjNew->Value = iFront = Gia_ManFrontFindNext( pFront, pNew->nFront, iFront );
        // deref the fanins
        if ( --Gia_ObjFanin0(pObj)->Value == 0 )
        {
            pFront[pFanin0New->Value] = 0;
            nCrossCut--;
        }
        if ( --Gia_ObjFanin1(pObj)->Value == 0 )
        {
            pFront[pFanin1New->Value] = 0;
            nCrossCut--;
        }
        // handle nodes without fanout (choice nodes)
        if ( Gia_ObjValue(pObj) == 0 )
            pFront[iFront] = 0;
    }
    assert( pNew->nObjs == p->nObjs );
    assert( nCrossCut == 0 || nCrossCutMax == nCrossCutMaxInit );
    for ( i = 0; i < pNew->nFront; i++ )
        assert( pFront[i] == 0 );
    ABC_FREE( pFront );
//printf( "Crosscut = %6d. Frontier = %6d. ", nCrossCutMaxInit, pNew->nFront );
//ABC_PRT( "Time", clock() - clk );
    Gia_ManSetRegNum( pNew, Gia_ManRegNum(p) );
    return pNew;
}

/**Function*************************************************************

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManFrontTest( Gia_Man_t * p )
{
    Gia_Man_t * pNew;
    pNew  = Gia_ManFront( p );
    Gia_ManFrontTransform( pNew );
//    Gia_ManCleanValue( p );
//    Gia_ManCleanValue( pNew );
    if ( memcmp( pNew->pObjs, p->pObjs, sizeof(Gia_Obj_t) * p->nObjs ) )
    {
/*
        Gia_Obj_t * pObj, * pObjNew;
        int i;
        Gia_ManForEachObj( p, pObj, i )
        {
            pObjNew = Gia_ManObj( pNew, i );
            printf( "%5d %5d   %5d %5d\n", 
                pObj->iDiff0, pObjNew->iDiff0, 
                pObj->iDiff1, pObjNew->iDiff1 );
        }
*/
        printf( "Verification failed.\n" );
    }
    else
        printf( "Verification successful.\n" );
    Gia_ManStop( pNew );
}

////////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


ABC_NAMESPACE_IMPL_END