1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/* Compatibility functions for floating point formatting, reentrant versions.
Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <sys/param.h>
#ifndef FLOAT_TYPE
# define FLOAT_TYPE double
# define FUNC_PREFIX
# define FLOAT_FMT_FLAG
# define FLOAT_NAME_EXT
# if DBL_MANT_DIG == 53
# define NDIGIT_MAX 17
# elif DBL_MANT_DIG == 24
# define NDIGIT_MAX 9
# elif DBL_MANT_DIG == 56
# define NDIGIT_MAX 18
# else
/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
compile time constant here, so we cannot use it. */
# error "NDIGIT_MAX must be precomputed"
# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
# endif
#endif
#define APPEND(a, b) APPEND2 (a, b)
#define APPEND2(a, b) a##b
#define FLOOR APPEND(floor, FLOAT_NAME_EXT)
#define FABS APPEND(fabs, FLOAT_NAME_EXT)
#define LOG10 APPEND(log10, FLOAT_NAME_EXT)
#define EXP APPEND(exp, FLOAT_NAME_EXT)
int
APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign, buf, len)
FLOAT_TYPE value;
int ndigit, *decpt, *sign;
char *buf;
size_t len;
{
int n, i;
int left;
if (buf == NULL)
{
__set_errno (EINVAL);
return -1;
}
left = 0;
if (isfinite (value))
{
*sign = signbit (value) != 0;
if (*sign)
value = -value;
if (ndigit < 0)
{
/* Rounding to the left of the decimal point. */
while (ndigit < 0)
{
FLOAT_TYPE new_value = value * 0.1;
if (new_value < 1.0)
{
ndigit = 0;
break;
}
value = new_value;
++left;
++ndigit;
}
}
}
else
/* Value is Inf or NaN. */
*sign = 0;
n = __snprintf (buf, len, "%.*" FLOAT_FMT_FLAG "f", MIN (ndigit, NDIGIT_MAX),
value);
if (n < 0)
return -1;
i = 0;
while (i < n && isdigit (buf[i]))
++i;
*decpt = i;
if (i == 0)
/* Value is Inf or NaN. */
return 0;
if (i < n)
{
do
++i;
while (i < n && !isdigit (buf[i]));
if (*decpt == 1 && buf[0] == '0' && value != 0.0)
{
/* We must not have leading zeroes. Strip them all out and
adjust *DECPT if necessary. */
--*decpt;
while (i < n && buf[i] == '0')
{
--*decpt;
++i;
}
}
memmove (&buf[MAX (*decpt, 0)], &buf[i], n - i);
buf[n - (i - MAX (*decpt, 0))] = '\0';
}
if (left)
{
*decpt += left;
if (--len > n)
{
while (left-- > 0 && n < len)
buf[n++] = '0';
buf[n] = '\0';
}
}
return 0;
}
int
APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign, buf, len)
FLOAT_TYPE value;
int ndigit, *decpt, *sign;
char *buf;
size_t len;
{
int exponent = 0;
if (isfinite (value) && value != 0.0)
{
/* Slow code that doesn't require -lm functions. */
FLOAT_TYPE d;
FLOAT_TYPE f = 1.0;
if (value < 0.0)
d = -value;
else
d = value;
if (d < 1.0)
{
do
{
f *= 10.0;
--exponent;
}
while (d * f < 1.0);
value *= f;
}
else if (d >= 10.0)
{
do
{
f *= 10;
++exponent;
}
while (d >= f * 10.0);
value /= f;
}
}
else if (value == 0.0)
/* SUSv2 leaves it unspecified whether *DECPT is 0 or 1 for 0.0.
This could be changed to -1 if we want to return 0. */
exponent = 0;
if (ndigit <= 0 && len > 0)
{
buf[0] = '\0';
*decpt = 1;
*sign = isfinite (value) ? signbit (value) != 0 : 0;
}
else
if (APPEND (FUNC_PREFIX, fcvt_r) (value, MIN (ndigit, NDIGIT_MAX) - 1,
decpt, sign, buf, len))
return -1;
*decpt += exponent;
return 0;
}
|
