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1eee94d3 GM |
1 | /* ldtoa.c provide long double floating point string conversion routines. |
2 | ||
a945c346 | 3 | Copyright (C) 2009-2024 Free Software Foundation, Inc. |
1eee94d3 GM |
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 | ||
62ed1066 GM |
31 | #define LIBNAME "m2pim" |
32 | ||
1eee94d3 GM |
33 | #include "gm2-libs-host.h" |
34 | #include "m2rts.h" | |
35 | ||
36 | # ifdef __cplusplus | |
37 | extern "C" { | |
38 | # endif | |
39 | ||
40 | #define MAX_FP_DIGITS 500 | |
41 | ||
42 | typedef enum Mode { maxsignicant, decimaldigits } Mode; | |
43 | ||
44 | extern int dtoa_calcmaxsig (char *p, int ndigits); | |
45 | extern int dtoa_calcdecimal (char *p, int str_size, int ndigits); | |
8804eb0b | 46 | extern bool dtoa_calcsign (char *p, int str_size); |
1eee94d3 GM |
47 | |
48 | /* maxsignicant: return a string containing max(1,ndigits) | |
49 | significant digits. The return string contains the string | |
50 | produced by snprintf. decimaldigits: return a string produced by | |
51 | fcvt. The string will contain ndigits past the decimal point | |
52 | (ndigits may be negative). */ | |
53 | ||
54 | long double | |
9f3b5c23 | 55 | ldtoa_strtold (void *s, bool *error) |
1eee94d3 GM |
56 | { |
57 | char *endp; | |
58 | long double d; | |
59 | ||
60 | errno = 0; | |
61 | #if defined(HAVE_STRTOLD) | |
9f3b5c23 | 62 | d = strtold (reinterpret_cast <char *> (s), &endp); |
1eee94d3 GM |
63 | #else |
64 | /* fall back to using strtod. */ | |
9f3b5c23 | 65 | d = (long double)strtod (reinterpret_cast <char *> (s), &endp); |
1eee94d3 GM |
66 | #endif |
67 | if (endp != NULL && (*endp == '\0')) | |
68 | *error = (errno != 0); | |
69 | else | |
8f1711ef | 70 | *error = true; |
1eee94d3 GM |
71 | return d; |
72 | } | |
73 | ||
74 | char * | |
8804eb0b | 75 | ldtoa_ldtoa (long double d, int mode, int ndigits, int *decpt, bool *sign) |
1eee94d3 GM |
76 | { |
77 | char format[50]; | |
78 | char *p; | |
79 | int r; | |
80 | switch (mode) | |
81 | { | |
82 | ||
83 | case maxsignicant: | |
84 | ndigits += 20; /* enough for exponent. */ | |
85 | p = (char *) malloc (ndigits); | |
86 | snprintf (format, 50, "%s%d%s", "%.", ndigits - 20, "LE"); | |
87 | snprintf (p, ndigits, format, d); | |
88 | *sign = dtoa_calcsign (p, ndigits); | |
89 | *decpt = dtoa_calcmaxsig (p, ndigits); | |
90 | return p; | |
91 | case decimaldigits: | |
92 | p = (char *) malloc (MAX_FP_DIGITS + 20); | |
93 | snprintf (format, 50, "%s%d%s", "%.", MAX_FP_DIGITS, "LE"); | |
94 | snprintf (p, MAX_FP_DIGITS + 20, format, d); | |
95 | *sign = dtoa_calcsign (p, MAX_FP_DIGITS + 20); | |
96 | *decpt = dtoa_calcdecimal (p, MAX_FP_DIGITS + 20, ndigits); | |
97 | return p; | |
98 | default: | |
99 | abort (); | |
100 | } | |
101 | } | |
102 | ||
103 | /* GNU Modula-2 hooks */ | |
104 | ||
105 | void | |
106 | _M2_ldtoa_init (int, char **, char **) | |
107 | { | |
108 | } | |
109 | ||
110 | void | |
111 | _M2_ldtoa_finish (int, char **, char **) | |
112 | { | |
113 | } | |
114 | ||
115 | void | |
116 | _M2_ldtoa_dep (void) | |
117 | { | |
118 | } | |
119 | ||
120 | # ifdef __cplusplus | |
121 | } | |
122 | ||
ec6d1fc0 IS |
123 | extern "C" void __attribute__((__constructor__)) |
124 | _M2_ldtoa_ctor (void) | |
1eee94d3 | 125 | { |
9f3b5c23 GM |
126 | M2RTS_RegisterModule_Cstr ("ldtoa", LIBNAME, _M2_ldtoa_init, |
127 | _M2_ldtoa_finish, _M2_ldtoa_dep); | |
1eee94d3 GM |
128 | } |
129 | ||
130 | #else | |
131 | void | |
132 | _M2_ldtoa_ctor (void) | |
133 | { | |
134 | } | |
135 | ||
136 | # endif |