blob: f98193ec712d6f579e45cd8fe33e48ecbdcea591 (
plain)
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
|
/* Floating-point exponent.
Copyright (C) 2012-2021 Free Software Foundation, Inc.
This file 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 3 of the
License, or (at your option) any later version.
This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
#if ! (defined USE_LONG_DOUBLE || defined USE_FLOAT)
# include <config.h>
#endif
/* Specification. */
#include <math.h>
#include <limits.h>
#ifdef USE_LONG_DOUBLE
# define ILOGB ilogbl
# define DOUBLE long double
# define L_(literal) literal##L
# define FREXP frexpl
# define ISNAN isnanl
#elif ! defined USE_FLOAT
# define ILOGB ilogb
# define DOUBLE double
# define L_(literal) literal
# define FREXP frexp
# define ISNAN isnand
#else /* defined USE_FLOAT */
# define ILOGB ilogbf
# define DOUBLE float
# define L_(literal) literal##f
# define FREXP frexpf
# define ISNAN isnanf
#endif
int
ILOGB (DOUBLE x)
{
if (isfinite (x))
{
if (x == L_(0.0))
return FP_ILOGB0;
else
{
int e;
(void) FREXP (x, &e);
return e - 1;
}
}
else
{
if (ISNAN (x))
return FP_ILOGBNAN;
else
return INT_MAX;
}
}
|
