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1 | /* ldtoa.c provide long double floating point string conversion routines. |
2 | ||
3 | Copyright (C) 2009-2022 Free Software Foundation, Inc. | |
4 | Contributed by Gaius Mulley <gaius@glam.ac.uk>. | |
5 | ||
6 | This file is part of GNU Modula-2. | |
7 | ||
8 | GNU Modula-2 is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GNU Modula-2 is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | General Public License for more details. | |
17 | ||
18 | Under Section 7 of GPL version 3, you are granted additional | |
19 | permissions described in the GCC Runtime Library Exception, version | |
20 | 3.1, as published by the Free Software Foundation. | |
21 | ||
22 | You should have received a copy of the GNU General Public License and | |
23 | a copy of the GCC Runtime Library Exception along with this program; | |
24 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
25 | <http://www.gnu.org/licenses/>. */ | |
26 | ||
27 | #include "config.h" | |
28 | #include "system.h" | |
29 | #include "ansidecl.h" | |
30 | ||
31 | #include "gm2-libs-host.h" | |
32 | #include "m2rts.h" | |
33 | ||
34 | # ifdef __cplusplus | |
35 | extern "C" { | |
36 | # endif | |
37 | ||
38 | #define MAX_FP_DIGITS 500 | |
39 | ||
40 | typedef enum Mode { maxsignicant, decimaldigits } Mode; | |
41 | ||
42 | extern int dtoa_calcmaxsig (char *p, int ndigits); | |
43 | extern int dtoa_calcdecimal (char *p, int str_size, int ndigits); | |
44 | extern int dtoa_calcsign (char *p, int str_size); | |
45 | ||
46 | /* maxsignicant: return a string containing max(1,ndigits) | |
47 | significant digits. The return string contains the string | |
48 | produced by snprintf. decimaldigits: return a string produced by | |
49 | fcvt. The string will contain ndigits past the decimal point | |
50 | (ndigits may be negative). */ | |
51 | ||
52 | long double | |
53 | ldtoa_strtold (const char *s, int *error) | |
54 | { | |
55 | char *endp; | |
56 | long double d; | |
57 | ||
58 | errno = 0; | |
59 | #if defined(HAVE_STRTOLD) | |
60 | d = strtold (s, &endp); | |
61 | #else | |
62 | /* fall back to using strtod. */ | |
63 | d = (long double)strtod (s, &endp); | |
64 | #endif | |
65 | if (endp != NULL && (*endp == '\0')) | |
66 | *error = (errno != 0); | |
67 | else | |
68 | *error = TRUE; | |
69 | return d; | |
70 | } | |
71 | ||
72 | char * | |
73 | ldtoa_ldtoa (long double d, int mode, int ndigits, int *decpt, int *sign) | |
74 | { | |
75 | char format[50]; | |
76 | char *p; | |
77 | int r; | |
78 | switch (mode) | |
79 | { | |
80 | ||
81 | case maxsignicant: | |
82 | ndigits += 20; /* enough for exponent. */ | |
83 | p = (char *) malloc (ndigits); | |
84 | snprintf (format, 50, "%s%d%s", "%.", ndigits - 20, "LE"); | |
85 | snprintf (p, ndigits, format, d); | |
86 | *sign = dtoa_calcsign (p, ndigits); | |
87 | *decpt = dtoa_calcmaxsig (p, ndigits); | |
88 | return p; | |
89 | case decimaldigits: | |
90 | p = (char *) malloc (MAX_FP_DIGITS + 20); | |
91 | snprintf (format, 50, "%s%d%s", "%.", MAX_FP_DIGITS, "LE"); | |
92 | snprintf (p, MAX_FP_DIGITS + 20, format, d); | |
93 | *sign = dtoa_calcsign (p, MAX_FP_DIGITS + 20); | |
94 | *decpt = dtoa_calcdecimal (p, MAX_FP_DIGITS + 20, ndigits); | |
95 | return p; | |
96 | default: | |
97 | abort (); | |
98 | } | |
99 | } | |
100 | ||
101 | /* GNU Modula-2 hooks */ | |
102 | ||
103 | void | |
104 | _M2_ldtoa_init (int, char **, char **) | |
105 | { | |
106 | } | |
107 | ||
108 | void | |
109 | _M2_ldtoa_finish (int, char **, char **) | |
110 | { | |
111 | } | |
112 | ||
113 | void | |
114 | _M2_ldtoa_dep (void) | |
115 | { | |
116 | } | |
117 | ||
118 | # ifdef __cplusplus | |
119 | } | |
120 | ||
121 | struct _M2_ldtoa_ctor { _M2_ldtoa_ctor (); } _M2_ldtoa_ctor; | |
122 | ||
123 | _M2_ldtoa_ctor::_M2_ldtoa_ctor (void) | |
124 | { | |
125 | M2RTS_RegisterModule ("ldtoa", _M2_ldtoa_init, _M2_ldtoa_finish, | |
126 | _M2_ldtoa_dep); | |
127 | } | |
128 | ||
129 | #else | |
130 | void | |
131 | _M2_ldtoa_ctor (void) | |
132 | { | |
133 | } | |
134 | ||
135 | # endif |