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
|
/*
* Revision Control Information
*
* $Source$
* $Author$
* $Revision$
* $Date$
*
*/
#include "espresso.h"
ABC_NAMESPACE_IMPL_START
static bool primes_consensus_special_cases();
static pcover primes_consensus_merge();
static pcover and_with_cofactor();
/* primes_consensus -- generate primes using consensus */
pcover primes_consensus(T)
pcube *T; /* T will be disposed of */
{
register pcube cl, cr;
register int best;
pcover Tnew, Tl, Tr;
if (primes_consensus_special_cases(T, &Tnew) == MAYBE) {
cl = new_cube();
cr = new_cube();
best = binate_split_select(T, cl, cr, COMPL);
Tl = primes_consensus(scofactor(T, cl, best));
Tr = primes_consensus(scofactor(T, cr, best));
Tnew = primes_consensus_merge(Tl, Tr, cl, cr);
free_cube(cl);
free_cube(cr);
free_cubelist(T);
}
return Tnew;
}
static bool
primes_consensus_special_cases(T, Tnew)
pcube *T; /* will be disposed if answer is determined */
pcover *Tnew; /* returned only if answer determined */
{
register pcube *T1, p, ceil, cof=T[0];
pcube last;
pcover A;
/* Check for no cubes in the cover */
if (T[2] == NULL) {
*Tnew = new_cover(0);
free_cubelist(T);
return TRUE;
}
/* Check for only a single cube in the cover */
if (T[3] == NULL) {
*Tnew = sf_addset(new_cover(1), set_or(cof, cof, T[2]));
free_cubelist(T);
return TRUE;
}
/* Check for a row of all 1's (implies function is a tautology) */
for(T1 = T+2; (p = *T1++) != NULL; ) {
if (full_row(p, cof)) {
*Tnew = sf_addset(new_cover(1), cube.fullset);
free_cubelist(T);
return TRUE;
}
}
/* Check for a column of all 0's which can be factored out */
ceil = set_save(cof);
for(T1 = T+2; (p = *T1++) != NULL; ) {
INLINEset_or(ceil, ceil, p);
}
if (! setp_equal(ceil, cube.fullset)) {
p = new_cube();
(void) set_diff(p, cube.fullset, ceil);
(void) set_or(cof, cof, p);
free_cube(p);
A = primes_consensus(T);
foreach_set(A, last, p) {
INLINEset_and(p, p, ceil);
}
*Tnew = A;
set_free(ceil);
return TRUE;
}
set_free(ceil);
/* Collect column counts, determine unate variables, etc. */
massive_count(T);
/* If single active variable not factored out above, then tautology ! */
if (cdata.vars_active == 1) {
*Tnew = sf_addset(new_cover(1), cube.fullset);
free_cubelist(T);
return TRUE;
/* Check for unate cover */
} else if (cdata.vars_unate == cdata.vars_active) {
A = cubeunlist(T);
*Tnew = sf_contain(A);
free_cubelist(T);
return TRUE;
/* Not much we can do about it */
} else {
return MAYBE;
}
}
static pcover
primes_consensus_merge(Tl, Tr, cl, cr)
pcover Tl, Tr;
pcube cl, cr;
{
register pcube pl, pr, lastl, lastr, pt;
pcover T, Tsave;
Tl = and_with_cofactor(Tl, cl);
Tr = and_with_cofactor(Tr, cr);
T = sf_new(500, Tl->sf_size);
pt = T->data;
Tsave = sf_contain(sf_join(Tl, Tr));
foreach_set(Tl, lastl, pl) {
foreach_set(Tr, lastr, pr) {
if (cdist01(pl, pr) == 1) {
consensus(pt, pl, pr);
if (++T->count >= T->capacity) {
Tsave = sf_union(Tsave, sf_contain(T));
T = sf_new(500, Tl->sf_size);
pt = T->data;
} else {
pt += T->wsize;
}
}
}
}
free_cover(Tl);
free_cover(Tr);
Tsave = sf_union(Tsave, sf_contain(T));
return Tsave;
}
static pcover
and_with_cofactor(A, cof)
pset_family A;
register pset cof;
{
register pset last, p;
foreach_set(A, last, p) {
INLINEset_and(p, p, cof);
if (cdist(p, cube.fullset) > 0) {
RESET(p, ACTIVE);
} else {
SET(p, ACTIVE);
}
}
return sf_inactive(A);
}
ABC_NAMESPACE_IMPL_END
|
