summaryrefslogtreecommitdiffstats
path: root/src/misc/espresso/exact.c
blob: 8bfa1ce39ce212819a5feaf55772d8dfd77838f3 (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
/*
 * Revision Control Information
 *
 * $Source$
 * $Author$
 * $Revision$
 * $Date$
 *
 */
#include "espresso.h"

ABC_NAMESPACE_IMPL_START



static void dump_irredundant();
static pcover do_minimize();


/*
 *  minimize_exact -- main entry point for exact minimization
 *
 *  Global flags which affect this routine are:
 *
 *      debug
 *      skip_make_sparse
 */

pcover
minimize_exact(F, D, R, exact_cover)
pcover F, D, R;
int exact_cover;
{
    return do_minimize(F, D, R, exact_cover, /*weighted*/ 0);
}


pcover
minimize_exact_literals(F, D, R, exact_cover)
pcover F, D, R;
int exact_cover;
{
    return do_minimize(F, D, R, exact_cover, /*weighted*/ 1);
}



static pcover
do_minimize(F, D, R, exact_cover, weighted)
pcover F, D, R;
int exact_cover;
int weighted;
{
    pcover newF, E, Rt, Rp;
    pset p, last;
    int heur, level, *weights, i;
    sm_matrix *table;
    sm_row *cover;
    sm_element *pe;
    int debug_save = debug;

    if (debug & EXACT) {
    debug |= (IRRED | MINCOV);
    }
#if defined(sun) || defined(bsd4_2)            /* hack ... */
    if (debug & MINCOV) {
    setlinebuf(stdout);
    }
#endif
    level = (debug & MINCOV) ? 4 : 0;
    heur = ! exact_cover;

    /* Generate all prime implicants */
    EXEC(F = primes_consensus(cube2list(F, D)), "PRIMES     ", F);

    /* Setup the prime implicant table */
    EXEC(irred_split_cover(F, D, &E, &Rt, &Rp), "ESSENTIALS ", E);
    EXEC(table = irred_derive_table(D, E, Rp),  "PI-TABLE   ", Rp);

    /* Solve either a weighted or nonweighted covering problem */
    if (weighted) {
    /* correct only for all 2-valued variables */
    weights = ALLOC(int, F->count);
    foreach_set(Rp, last, p) {
        weights[SIZE(p)] = cube.size - set_ord(p);
        /* We have added the 0's in the output part instead of the 1's.
           This loop corrects the literal count. */
        for (i = cube.first_part[cube.output];
         i <= cube.last_part[cube.output]; i++) {
        is_in_set(p, i) ? weights[SIZE(p)]++ : weights[SIZE(p)]--;
        }
    }
    } else {
    weights = NIL(int);
    }
    EXEC(cover=sm_minimum_cover(table,weights,heur,level), "MINCOV     ", F);
    if (weights != 0) {
    FREE(weights);
    }

    if (debug & EXACT) {
    dump_irredundant(E, Rt, Rp, table);
    }

    /* Form the result cover */
    newF = new_cover(100);
    foreach_set(E, last, p) {
    newF = sf_addset(newF, p);
    }
    sm_foreach_row_element(cover, pe) {
    newF = sf_addset(newF, GETSET(F, pe->col_num));
    }

    free_cover(E);
    free_cover(Rt);
    free_cover(Rp);
    sm_free(table);
    sm_row_free(cover);
    free_cover(F);

    /* Attempt to make the results more sparse */
    debug &= ~ (IRRED | SHARP | MINCOV);
    if (! skip_make_sparse && R != 0) {
    newF = make_sparse(newF, D, R);
    }

    debug = debug_save;
    return newF;
}

static void
dump_irredundant(E, Rt, Rp, table)
pcover E, Rt, Rp;
sm_matrix *table;
{
    FILE *fp_pi_table, *fp_primes;
    pPLA PLA;
    pset last, p;
    char *file;

    if (filename == 0 || strcmp(filename, "(stdin)") == 0) {
    fp_pi_table = fp_primes = stdout;
    } else {
    file = ALLOC(char, strlen(filename)+20);
    (void) sprintf(file, "%s.primes", filename);
    if ((fp_primes = fopen(file, "w")) == NULL) {
        (void) fprintf(stderr, "espresso: Unable to open %s\n", file);
        fp_primes = stdout;
    }
    (void) sprintf(file, "%s.pi", filename);
    if ((fp_pi_table = fopen(file, "w")) == NULL) {
        (void) fprintf(stderr, "espresso: Unable to open %s\n", file);
        fp_pi_table = stdout;
    }
    FREE(file);
    }

    PLA = new_PLA();
    PLA_labels(PLA);

    fpr_header(fp_primes, PLA, F_type);
    free_PLA(PLA);

    (void) fprintf(fp_primes, "# Essential primes are\n");
    foreach_set(E, last, p) {
    (void) fprintf(fp_primes, "%s\n", pc1(p));
    }
    (void) fprintf(fp_primes, "# Totally redundant primes are\n");
    foreach_set(Rt, last, p) {
    (void) fprintf(fp_primes, "%s\n", pc1(p));
    }
    (void) fprintf(fp_primes, "# Partially redundant primes are\n");
    foreach_set(Rp, last, p) {
    (void) fprintf(fp_primes, "%s\n", pc1(p));
    }
    if (fp_primes != stdout) {
    (void) fclose(fp_primes);
    }
    
    sm_write(fp_pi_table, table);
    if (fp_pi_table != stdout) {
    (void) fclose(fp_pi_table);
    }
}
ABC_NAMESPACE_IMPL_END