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
212
213
214
215
216
217
218
219
220
221
222
223
|
/* mpfr_set_str -- set a floating-point number from a string
Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of the MPFR Library.
The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.
The MPFR 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the MPFR 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 <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "longlong.h"
#include "mpfr.h"
#include "mpfr-impl.h"
/* from mpf/set_str.c */
static int
digit_value_in_base (int c, int base)
{
int digit;
if (isdigit (c))
digit = c - '0';
else if (islower (c))
digit = c - 'a' + 10;
else if (isupper (c))
digit = c - 'A' + 10;
else
return -1;
if (digit < base)
return digit;
return -1;
}
int
mpfr_set_str (mpfr_ptr x, __gmp_const char *str, int base, mp_rnd_t rnd_mode)
{
mpz_t mantissa;
int negative, inex, value;
long k = 0;
unsigned char c;
long e;
mp_prec_t q;
mpfr_t y, z;
const char *str0 = str;
if (base < 2 || base > 36)
return -1;
/* be careful that 'nan' is a valid number in base >= 24,
since n=23, a=10, n=23 */
if (((base < 24) ? strncasecmp : strncmp) (str, "NaN", 3) == 0)
{
MPFR_SET_NAN(x);
/* MPFR_RET_NAN not used as the return value isn't a ternary value */
__mpfr_flags |= MPFR_FLAGS_NAN;
return 3;
}
negative = *str == '-';
if (negative || *str == '+')
str++;
/* be careful that 'inf' is a valid number in base >= 24,
since i=18, n=23, f=15 */
if (((base < 24) ? strncasecmp : strncmp) (str, "Inf", 3) == 0)
{
MPFR_CLEAR_NAN(x);
MPFR_SET_INF(x);
if (negative)
MPFR_SET_NEG(x);
else
MPFR_SET_POS(x);
return 3 + (str - str0);
}
mpz_init (mantissa);
mpz_set_ui (mantissa, 0);
while (*str == '0')
str++; /* skip initial zeros */
/* allowed characters are '0' to '0'+base-1 if base <= 10,
and '0' to '9' plus 'a' to 'a'+base-11 if 10 < base <= 36 */
while (c = *str,
(value = digit_value_in_base (c, base)) >= 0)
{
str++;
mpz_mul_ui (mantissa, mantissa, base);
mpz_add_ui (mantissa, mantissa, value);
}
/* k is the number of non-zero digits before the decimal point */
if (*str == '.')
{
str++;
while (c = *str,
(isdigit(c) && c < '0' + base) ||
(islower(c) && c < 'a'-10 + base))
{
if (k == LONG_MAX)
{
mpz_clear (mantissa);
return -1;
}
k++;
str++;
mpz_mul_ui (mantissa, mantissa, base);
mpz_add_ui (mantissa, mantissa, isdigit(c) ? c - '0' : c - ('a' - 10));
}
}
if ((base <= 10 && (*str == 'e' || *str == 'E')) || *str == '@')
{
char *endptr;
if (*++str == '\0') /* exponent character but no exponent */
{
mpz_clear (mantissa);
return -1;
}
errno = 0;
e = strtol (str, &endptr, 10); /* signed exponent after 'e', 'E' or '@' */
#ifdef REQUIRE_END_OF_STRING
if (*endptr != '\0')
{
mpz_clear (mantissa);
return -1;
}
#endif
str = endptr;
if (errno)
{
mpz_clear(mantissa);
return -1;
}
if (e < 0 && (unsigned long) e - k < (unsigned long) LONG_MIN)
{
mpz_clear(mantissa);
return -1;
}
e -= k;
}
else /* no exponent */
{
#ifdef REQUIRE_END_OF_STRING
if (*str != '\0')
{
mpz_clear (mantissa);
return -1;
}
#endif
e = -k;
}
/* the number is mantissa*base^expn */
q = MPFR_PREC(x) & ~(mp_prec_t) (BITS_PER_MP_LIMB - 1);
mpfr_init (y);
mpfr_init (z);
do
{
q += BITS_PER_MP_LIMB;
mpfr_set_prec (y, q);
mpfr_set_z (y, mantissa, GMP_RNDN); /* error <= 1/2*ulp(y) */
mpfr_set_prec (z, q);
if (e > 0)
{
inex = mpfr_ui_pow_ui (z, base, e, GMP_RNDN);
mpfr_mul (y, y, z, GMP_RNDN);
}
else if (e < 0)
{
inex = mpfr_ui_pow_ui (z, base, -e, GMP_RNDN);
mpfr_div (y, y, z, GMP_RNDN);
}
else
inex = 1;
if (negative)
mpfr_neg (y, y, GMP_RNDN);
}
while (mpfr_can_round (y, q-inex, GMP_RNDN, rnd_mode, MPFR_PREC(x)) == 0
&& q <= 2*MPFR_PREC(x));
mpfr_set (x, y, rnd_mode);
mpz_clear (mantissa);
mpfr_clear (y);
mpfr_clear (z);
return str - str0;
}
int
mpfr_init_set_str (mpfr_ptr x, char *str, int base, mp_rnd_t rnd_mode)
{
mpfr_init (x);
return mpfr_set_str (x, str, base, rnd_mode);
}
|
