1 /* Generate Fibonacci table data.
2
3 Copyright 2001, 2002, 2004, 2012, 2014, 2015 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library.
6
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of either:
9
10 * the GNU Lesser General Public License as published by the Free
11 Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
13
14 or
15
16 * the GNU General Public License as published by the Free Software
17 Foundation; either version 2 of the License, or (at your option) any
18 later version.
19
20 or both in parallel, as here.
21
22 The GNU MP Library is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
25 for more details.
26
27 You should have received copies of the GNU General Public License and the
28 GNU Lesser General Public License along with the GNU MP Library. If not,
29 see https://www.gnu.org/licenses/. */
30
31 #include <stdio.h>
32 #include "bootstrap.c"
33
34 mpz_t *f;
35 int fnum, fib_limit, luc_limit;
36
37 void
generate(int numb_bits)38 generate (int numb_bits)
39 {
40 mpz_t limit, l;
41 int falloc, i;
42
43 mpz_init2 (limit, numb_bits + 1);
44 mpz_setbit (limit, numb_bits);
45
46 /* fib(2n) > 2^n, so use 2n as a limit for the table size */
47 falloc = 2 * numb_bits;
48 f = (mpz_t*) xmalloc (falloc * sizeof (*f));
49
50 mpz_init_set_ui (f[0], 1L); /* F[-1] */
51 mpz_init_set_ui (f[1], 0L); /* F[0] */
52
53 mpz_init (l);
54
55 for (i = 2; ; i++)
56 {
57 assert (i < falloc);
58
59 /* F[i] = F[i-1] + F[i-2] */
60 mpz_init (f[i]);
61 mpz_add (f[i], f[i-1], f[i-2]);
62 if (mpz_cmp (f[i], limit) >= 0)
63 break;
64
65 fnum = i+1;
66 fib_limit = i-1;
67
68 /* L[i] = F[i]+2*F[i-1] */
69 mpz_add (l, f[i], f[i-1]);
70 mpz_add (l, l, f[i-1]);
71
72 if (mpz_cmp (l, limit) < 0)
73 luc_limit = i-1;
74 }
75
76 mpz_clear (limit);
77 }
78
79
80 void
header(int numb_bits)81 header (int numb_bits)
82 {
83 printf ("/* This file generated by gen-fib.c - DO NOT EDIT. */\n");
84 printf ("\n");
85 printf ("#if GMP_NUMB_BITS != %d\n", numb_bits);
86 printf ("Error, error, this data is for %d bits\n", numb_bits);
87 printf ("#endif\n");
88 printf ("\n");
89 printf ("#define FIB_TABLE_LIMIT %d\n", fib_limit);
90 printf ("#define FIB_TABLE_LUCNUM_LIMIT %d\n", luc_limit);
91 }
92
93 void
table(int numb_bits)94 table (int numb_bits)
95 {
96 int i;
97
98 printf ("/* This file generated by gen-fib.c - DO NOT EDIT. */\n");
99 printf ("\n");
100 printf ("#include \"gmp.h\"\n");
101 printf ("#include \"gmp-impl.h\"\n");
102 printf ("\n");
103 printf ("#if GMP_NUMB_BITS != %d\n", numb_bits);
104 printf ("Error, error, this data is for %d bits\n", numb_bits);
105 printf ("#endif\n");
106 printf ("\n");
107 printf ("const mp_limb_t\n");
108 printf ("__gmp_fib_table[FIB_TABLE_LIMIT+2] = {\n");
109
110 for (i = 0; i < fnum; i++)
111 {
112 printf (" CNST_LIMB (0x");
113 mpz_out_str (stdout, 16, f[i]);
114 printf ("), /* %d */\n", i-1);
115 }
116 printf ("};\n");
117 }
118
119 int
main(int argc,char * argv[])120 main (int argc, char *argv[])
121 {
122 int limb_bits, nail_bits, numb_bits;
123
124 if (argc != 4)
125 {
126 fprintf (stderr, "Usage: gen-fib <header|table> <limbbits> <nailbits>\n");
127 exit (1);
128 }
129
130 limb_bits = atoi (argv[2]);
131 nail_bits = atoi (argv[3]);
132
133 if (limb_bits <= 0
134 || nail_bits < 0
135 || nail_bits >= limb_bits)
136 {
137 fprintf (stderr, "Invalid limb/nail bits: %d %d\n",
138 limb_bits, nail_bits);
139 exit (1);
140 }
141 numb_bits = limb_bits - nail_bits;
142
143 generate (numb_bits);
144
145 if (strcmp (argv[1], "header") == 0)
146 header (numb_bits);
147 else if (strcmp (argv[1], "table") == 0)
148 table (numb_bits);
149 else
150 {
151 fprintf (stderr, "Invalid header/table choice: %s\n", argv[1]);
152 exit (1);
153 }
154
155 return 0;
156 }
157