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
|
/* Test of splitting a 'long double' into fraction and mantissa.
Copyright (C) 2007-2008 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
#include <config.h>
#include "printf-frexpl.h"
#include <float.h>
#include <stdio.h>
#include <stdlib.h>
#include "fpucw.h"
#define ASSERT(expr) \
do \
{ \
if (!(expr)) \
{ \
fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
fflush (stderr); \
abort (); \
} \
} \
while (0)
/* On MIPS IRIX machines, LDBL_MIN_EXP is -1021, but the smallest reliable
exponent for 'long double' is -964. Similarly, on PowerPC machines,
LDBL_MIN_EXP is -1021, but the smallest reliable exponent for 'long double'
is -968. For exponents below that, the precision may be truncated to the
precision used for 'double'. */
#ifdef __sgi
# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 57)
# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
#elif defined __ppc || defined __ppc__ || defined __powerpc || defined __powerpc__
# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 53)
# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
#else
# define MIN_NORMAL_EXP LDBL_MIN_EXP
# define MIN_SUBNORMAL_EXP (LDBL_MIN_EXP - 100)
#endif
static long double
my_ldexp (long double x, int d)
{
for (; d > 0; d--)
x *= 2.0L;
for (; d < 0; d++)
x *= 0.5L;
return x;
}
int
main ()
{
int i;
long double x;
DECL_LONG_DOUBLE_ROUNDING
BEGIN_LONG_DOUBLE_ROUNDING ();
for (i = 1, x = 1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.0L);
}
for (i = 1, x = 1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.0L);
}
for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == LDBL_MIN_EXP - 1);
ASSERT (mantissa == my_ldexp (1.0L, i - LDBL_MIN_EXP));
}
for (i = 1, x = 1.01L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.01L);
}
for (i = 1, x = 1.01L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.01L);
}
for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == LDBL_MIN_EXP - 1);
ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
ASSERT (mantissa == my_ldexp (x, - exp));
}
for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.73205L);
}
for (i = 1, x = 1.73205L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == i - 1);
ASSERT (mantissa == 1.73205L);
}
for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = printf_frexpl (x, &exp);
ASSERT (exp == LDBL_MIN_EXP - 1);
ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
ASSERT (mantissa == my_ldexp (x, - exp));
}
return 0;
}
|
