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[xemacs-hg @ 2004-04-05 22:49:31 by james] Add bignum, ratio, and bigfloat support.
author james
date Mon, 05 Apr 2004 22:50:11 +0000
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children 4e6a63799f08
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1982:a748951fd4fb 1983:9c872f33ecbe
1 /* Numeric types for XEmacs using the GNU MP library.
2 Copyright (C) 2004 Jerry James.
3
4 This file is part of XEmacs.
5
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
9 later version.
10
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21 /* Synched up with: Not in FSF. */
22
23 #include <config.h>
24 #include <limits.h>
25 #include <math.h>
26 #include "lisp.h"
27
28 static mpf_t float_print_min, float_print_max;
29 gmp_randstate_t random_state;
30
31 CIbyte *
32 bigfloat_to_string(mpf_t f, int base)
33 {
34 mp_exp_t expt;
35 CIbyte *str = mpf_get_str (NULL, &expt, base, 0, f);
36 const int sign = mpf_sgn (f);
37 const int neg = (sign < 0) ? 1 : 0;
38 int len = strlen (str) + 1; /* Count the null terminator */
39
40 if (sign == 0 || (mpf_cmp (float_print_min, f) <= 0 &&
41 mpf_cmp (f, float_print_max) <= 0))
42 {
43 /* Move digits down to insert a radix point */
44 if (expt <= 0)
45 {
46 /* We need room for a radix point and leading zeroes */
47 const int space = -expt + 2;
48 XREALLOC_ARRAY (str, CIbyte, len + space);
49 memmove (&str[space + neg], &str[neg], len - neg);
50 memset (&str[neg], '0', space);
51 str[neg + 1] = '.';
52 len += space;
53 }
54 else
55 {
56 /* We just need room for a radix point */
57 XREALLOC_ARRAY (str, CIbyte, len + 1);
58 memmove (&str[expt + neg + 1], &str[expt + neg], len - (expt + neg));
59 str[expt + neg] = '.';
60 len++;
61 }
62 }
63 else
64 {
65 /* Computerized scientific notation */
66 /* We need room for a radix point, format identifier, and exponent */
67 const int space = (expt < 0)
68 ? (int)(log (-expt) / log (base)) + 3
69 : (int)(log (expt) / log (base)) + 2;
70 XREALLOC_ARRAY (str, CIbyte, len + space);
71 memmove (&str[neg + 2], &str[neg + 1], len - neg);
72 str[len + 1] = 'l';
73 sprintf (&str[len + 2], "%ld", expt);
74 }
75 return str;
76 }
77
78 /* We need the next two functions since GNU MP insists on giving us an extra
79 parameter. */
80 static void *gmp_realloc (void *ptr, size_t old_size /* unused */,
81 size_t new_size)
82 {
83 return xrealloc (ptr, new_size);
84 }
85
86 static void gmp_free (void *ptr, size_t size /* unused */)
87 {
88 xfree (ptr, void *);
89 }
90
91 void
92 init_number_gmp ()
93 {
94 mp_set_memory_functions ((void *(*) (size_t))xmalloc, gmp_realloc, gmp_free);
95
96 /* The smallest number that is printed without exponents */
97 mpf_init_set_d (float_print_min, 0.001);
98
99 /* The largest number that is printed without exponents */
100 mpf_init_set_ui (float_print_max, 10000000UL);
101
102 /* Prepare the bignum/bigfloat random number generator */
103 gmp_randinit_default (random_state);
104 gmp_randseed_ui (random_state, qxe_getpid () + time (NULL));
105 }