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19361cb7 | 1 | /* Compatibility functions for floating point formatting, reentrant versions. |
688903eb | 2 | Copyright (C) 1995-2018 Free Software Foundation, Inc. |
19361cb7 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
19361cb7 UD |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
19361cb7 | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
60478656 RM |
18 | |
19 | #include <errno.h> | |
1420df2c | 20 | #include <float.h> |
60478656 RM |
21 | #include <stdio.h> |
22 | #include <string.h> | |
23 | #include <ctype.h> | |
24 | #include <math.h> | |
1d8dc429 | 25 | #include <stdlib.h> |
da2d1bc5 | 26 | #include <sys/param.h> |
1d446ec6 | 27 | #include <math_ldbl_opt.h> |
60478656 | 28 | |
2064087b | 29 | #ifndef FLOAT_TYPE |
67994d6f UD |
30 | # define FLOAT_TYPE double |
31 | # define FUNC_PREFIX | |
32 | # define FLOAT_FMT_FLAG | |
33 | # define FLOAT_NAME_EXT | |
ec8c29dc | 34 | # define FLOAT_MIN_10_EXP DBL_MIN_10_EXP |
b113c12c UD |
35 | # if DBL_MANT_DIG == 53 |
36 | # define NDIGIT_MAX 17 | |
f9a2a636 UD |
37 | # elif DBL_MANT_DIG == 24 |
38 | # define NDIGIT_MAX 9 | |
39 | # elif DBL_MANT_DIG == 56 | |
40 | # define NDIGIT_MAX 18 | |
b113c12c | 41 | # else |
f9a2a636 UD |
42 | /* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a |
43 | compile time constant here, so we cannot use it. */ | |
44 | # error "NDIGIT_MAX must be precomputed" | |
b113c12c UD |
45 | # define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0))) |
46 | # endif | |
ec8c29dc UD |
47 | # if DBL_MIN_10_EXP == -37 |
48 | # define FLOAT_MIN_10_NORM 1.0e-37 | |
49 | # elif DBL_MIN_10_EXP == -307 | |
50 | # define FLOAT_MIN_10_NORM 1.0e-307 | |
51 | # elif DBL_MIN_10_EXP == -4931 | |
52 | # define FLOAT_MIN_10_NORM 1.0e-4931 | |
53 | # else | |
54 | /* libc can't depend on libm. */ | |
55 | # error "FLOAT_MIN_10_NORM must be precomputed" | |
56 | # define FLOAT_MIN_10_NORM exp10 (DBL_MIN_10_EXP) | |
57 | # endif | |
c6251f03 RM |
58 | #else |
59 | # define LONG_DOUBLE_CVT | |
2064087b RM |
60 | #endif |
61 | ||
62 | #define APPEND(a, b) APPEND2 (a, b) | |
63 | #define APPEND2(a, b) a##b | |
c6251f03 RM |
64 | #define __APPEND(a, b) __APPEND2 (a, b) |
65 | #define __APPEND2(a, b) __##a##b | |
2064087b RM |
66 | |
67 | #define FLOOR APPEND(floor, FLOAT_NAME_EXT) | |
68 | #define FABS APPEND(fabs, FLOAT_NAME_EXT) | |
69 | #define LOG10 APPEND(log10, FLOAT_NAME_EXT) | |
1f205a47 | 70 | #define EXP APPEND(exp, FLOAT_NAME_EXT) |
2064087b RM |
71 | |
72 | ||
60478656 | 73 | int |
80d9be81 JM |
74 | __APPEND (FUNC_PREFIX, fcvt_r) (FLOAT_TYPE value, int ndigit, int *decpt, |
75 | int *sign, char *buf, size_t len) | |
60478656 | 76 | { |
2a068d20 UD |
77 | ssize_t n; |
78 | ssize_t i; | |
1eb687d0 | 79 | int left; |
60478656 RM |
80 | |
81 | if (buf == NULL) | |
82 | { | |
c4029823 | 83 | __set_errno (EINVAL); |
60478656 RM |
84 | return -1; |
85 | } | |
86 | ||
1eb687d0 | 87 | left = 0; |
1f205a47 UD |
88 | if (isfinite (value)) |
89 | { | |
90 | *sign = signbit (value) != 0; | |
91 | if (*sign) | |
92 | value = -value; | |
da2d1bc5 UD |
93 | |
94 | if (ndigit < 0) | |
95 | { | |
96 | /* Rounding to the left of the decimal point. */ | |
1eb687d0 UD |
97 | while (ndigit < 0) |
98 | { | |
99 | FLOAT_TYPE new_value = value * 0.1; | |
100 | ||
101 | if (new_value < 1.0) | |
102 | { | |
103 | ndigit = 0; | |
104 | break; | |
105 | } | |
da2d1bc5 | 106 | |
1eb687d0 UD |
107 | value = new_value; |
108 | ++left; | |
109 | ++ndigit; | |
110 | } | |
da2d1bc5 | 111 | } |
1f205a47 | 112 | } |
07b51ba5 UD |
113 | else |
114 | /* Value is Inf or NaN. */ | |
115 | *sign = 0; | |
116 | ||
67994d6f UD |
117 | n = __snprintf (buf, len, "%.*" FLOAT_FMT_FLAG "f", MIN (ndigit, NDIGIT_MAX), |
118 | value); | |
b9d3d9f7 | 119 | /* Check for a too small buffer. */ |
2a068d20 | 120 | if (n >= (ssize_t) len) |
60478656 RM |
121 | return -1; |
122 | ||
123 | i = 0; | |
124 | while (i < n && isdigit (buf[i])) | |
125 | ++i; | |
126 | *decpt = i; | |
1f205a47 UD |
127 | |
128 | if (i == 0) | |
07b51ba5 UD |
129 | /* Value is Inf or NaN. */ |
130 | return 0; | |
1f205a47 UD |
131 | |
132 | if (i < n) | |
133 | { | |
134 | do | |
135 | ++i; | |
136 | while (i < n && !isdigit (buf[i])); | |
da2d1bc5 | 137 | |
b8ce6e3e | 138 | if (*decpt == 1 && buf[0] == '0' && value != 0.0) |
da2d1bc5 UD |
139 | { |
140 | /* We must not have leading zeroes. Strip them all out and | |
141 | adjust *DECPT if necessary. */ | |
142 | --*decpt; | |
143 | while (i < n && buf[i] == '0') | |
144 | { | |
145 | --*decpt; | |
146 | ++i; | |
147 | } | |
148 | } | |
149 | ||
150 | memmove (&buf[MAX (*decpt, 0)], &buf[i], n - i); | |
151 | buf[n - (i - MAX (*decpt, 0))] = '\0'; | |
1f205a47 | 152 | } |
60478656 | 153 | |
1eb687d0 UD |
154 | if (left) |
155 | { | |
156 | *decpt += left; | |
6dd67bd5 | 157 | if ((ssize_t) --len > n) |
1eb687d0 | 158 | { |
6dd67bd5 | 159 | while (left-- > 0 && n < (ssize_t) len) |
1eb687d0 UD |
160 | buf[n++] = '0'; |
161 | buf[n] = '\0'; | |
162 | } | |
163 | } | |
164 | ||
60478656 RM |
165 | return 0; |
166 | } | |
167 | ||
168 | int | |
80d9be81 JM |
169 | __APPEND (FUNC_PREFIX, ecvt_r) (FLOAT_TYPE value, int ndigit, int *decpt, |
170 | int *sign, char *buf, size_t len) | |
60478656 | 171 | { |
1f205a47 | 172 | int exponent = 0; |
0676b5fd | 173 | |
1f205a47 | 174 | if (isfinite (value) && value != 0.0) |
4d585333 | 175 | { |
ff8ac383 UD |
176 | /* Slow code that doesn't require -lm functions. */ |
177 | FLOAT_TYPE d; | |
178 | FLOAT_TYPE f = 1.0; | |
179 | if (value < 0.0) | |
180 | d = -value; | |
1f205a47 | 181 | else |
ff8ac383 | 182 | d = value; |
ec8c29dc UD |
183 | /* For denormalized numbers the d < 1.0 case below won't work, |
184 | as f can overflow to +Inf. */ | |
185 | if (d < FLOAT_MIN_10_NORM) | |
186 | { | |
187 | value /= FLOAT_MIN_10_NORM; | |
188 | if (value < 0.0) | |
189 | d = -value; | |
190 | else | |
191 | d = value; | |
192 | exponent += FLOAT_MIN_10_EXP; | |
193 | } | |
ff8ac383 | 194 | if (d < 1.0) |
1f205a47 | 195 | { |
ff8ac383 | 196 | do |
1f205a47 | 197 | { |
ff8ac383 UD |
198 | f *= 10.0; |
199 | --exponent; | |
1f205a47 | 200 | } |
ff8ac383 UD |
201 | while (d * f < 1.0); |
202 | ||
203 | value *= f; | |
204 | } | |
205 | else if (d >= 10.0) | |
206 | { | |
207 | do | |
1f205a47 | 208 | { |
ff8ac383 UD |
209 | f *= 10; |
210 | ++exponent; | |
1f205a47 | 211 | } |
ff8ac383 UD |
212 | while (d >= f * 10.0); |
213 | ||
214 | value /= f; | |
1f205a47 | 215 | } |
4d585333 | 216 | } |
da2d1bc5 UD |
217 | else if (value == 0.0) |
218 | /* SUSv2 leaves it unspecified whether *DECPT is 0 or 1 for 0.0. | |
219 | This could be changed to -1 if we want to return 0. */ | |
220 | exponent = 0; | |
221 | ||
222 | if (ndigit <= 0 && len > 0) | |
223 | { | |
224 | buf[0] = '\0'; | |
225 | *decpt = 1; | |
226 | *sign = isfinite (value) ? signbit (value) != 0 : 0; | |
227 | } | |
228 | else | |
c6251f03 RM |
229 | if (__APPEND (FUNC_PREFIX, fcvt_r) (value, MIN (ndigit, NDIGIT_MAX) - 1, |
230 | decpt, sign, buf, len)) | |
da2d1bc5 | 231 | return -1; |
4d585333 | 232 | |
1f205a47 UD |
233 | *decpt += exponent; |
234 | return 0; | |
60478656 | 235 | } |
c6251f03 RM |
236 | |
237 | #if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0) | |
238 | # ifdef LONG_DOUBLE_CVT | |
239 | # define cvt_symbol(symbol) \ | |
240 | cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \ | |
241 | APPEND (FUNC_PREFIX, symbol), GLIBC_2_4) | |
242 | # define cvt_symbol_1(lib, local, symbol, version) \ | |
8ed3b643 | 243 | libc_hidden_def (local) \ |
c6251f03 RM |
244 | versioned_symbol (lib, local, symbol, version) |
245 | # else | |
246 | # define cvt_symbol(symbol) \ | |
247 | cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \ | |
248 | APPEND (q, symbol), GLIBC_2_0); \ | |
498c1f6a | 249 | weak_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol)) |
c6251f03 | 250 | # define cvt_symbol_1(lib, local, symbol, version) \ |
8ed3b643 | 251 | libc_hidden_def (local) \ |
c6251f03 RM |
252 | compat_symbol (lib, local, symbol, version) |
253 | # endif | |
254 | #else | |
255 | # define cvt_symbol(symbol) \ | |
8ed3b643 L |
256 | cvt_symbol_1 (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol)) |
257 | # define cvt_symbol_1(local, symbol) \ | |
258 | libc_hidden_def (local) \ | |
259 | weak_alias (local, symbol) | |
c6251f03 RM |
260 | #endif |
261 | cvt_symbol(fcvt_r); | |
262 | cvt_symbol(ecvt_r); |