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
|
#include <stdio.h>
#include <stdlib.h>
#include "boolector.h"
#include "utils/btorutil.h"
int
main (int argc, char **argv)
{
int num_bits, num_bits_index, num_elements, i;
Btor *btor;
BoolectorNode **indices, *array, *eq;
BoolectorNode *temp, *read, *formula, *val, *index, *found;
BoolectorSort isort, esort, asort;
if (argc != 3)
{
printf ("Usage: ./linearsearch <num-bits> <num-elements>\n");
return 1;
}
num_bits = atoi (argv[1]);
if (num_bits <= 0)
{
printf ("Number of bits must be greater than zero\n");
return 1;
}
num_elements = atoi (argv[2]);
if (num_elements <= 1)
{
printf ("Number of elements must be greater than one\n");
return 1;
}
if (!btor_util_is_power_of_2 (num_elements))
{
printf ("Number of elements must be a power of two\n");
return 1;
}
num_bits_index = btor_util_log_2 (num_elements);
btor = boolector_new ();
boolector_set_opt (btor, BTOR_OPT_REWRITE_LEVEL, 0);
indices = (BoolectorNode **) malloc (sizeof (BoolectorNode *) * num_elements);
isort = boolector_bitvec_sort (btor, num_bits_index);
esort = boolector_bitvec_sort (btor, num_bits);
asort = boolector_array_sort (btor, isort, esort);
for (i = 0; i < num_elements; i++)
indices[i] = boolector_int (btor, i, isort);
array = boolector_array (btor, asort, "array");
/* we write arbitrary search value into array at an arbitrary index */
val = boolector_var (btor, esort, "search_val");
index = boolector_var (btor, isort, "search_index");
temp = boolector_write (btor, array, index, val);
boolector_release (btor, array);
array = temp;
found = boolector_const (btor, "0");
/* we search */
for (i = 0; i < num_elements; i++)
{
read = boolector_read (btor, array, indices[i]);
eq = boolector_eq (btor, read, val);
temp = boolector_or (btor, found, eq);
boolector_release (btor, found);
found = temp;
boolector_release (btor, read);
boolector_release (btor, eq);
}
/* we negate the formula and show that it is unsatisfiable */
formula = boolector_not (btor, found);
boolector_dump_btor_node (btor, stdout, formula);
/* clean up */
for (i = 0; i < num_elements; i++) boolector_release (btor, indices[i]);
boolector_release (btor, formula);
boolector_release (btor, index);
boolector_release (btor, val);
boolector_release (btor, found);
boolector_release (btor, array);
boolector_release_sort (btor, isort);
boolector_release_sort (btor, esort);
boolector_release_sort (btor, asort);
boolector_delete (btor);
free (indices);
return 0;
}
|
