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
|
/* `HUGE_VAL' constants for IEEE 754 machines (where it is infinity).
Used by <stdlib.h> and <math.h> functions for overflow.
Copyright (C) 1992, 1995, 1996, 1997, 1999, 2000 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. */
#ifndef _MATH_H
# error "Never use <bits/huge_val.h> directly; include <math.h> instead."
#endif
#include <features.h>
/* IEEE positive infinity (-HUGE_VAL is negative infinity). */
#ifdef __GNUC__
# if __GNUC_PREREQ(2,95)
# define HUGE_VAL (__extension__ 0x1.0p2047)
# else
# define HUGE_VAL \
(__extension__ \
((union { unsigned __l __attribute__((__mode__(__DI__))); double __d; }) \
{ __l: 0x7ff0000000000000ULL }).__d)
# endif
#else /* not GCC */
# include <endian.h>
typedef union { unsigned char __c[8]; double __d; } __huge_val_t;
# if __BYTE_ORDER == __BIG_ENDIAN
# define __HUGE_VAL_bytes { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 }
# endif
# if __BYTE_ORDER == __LITTLE_ENDIAN
# define __HUGE_VAL_bytes { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }
# endif
static __huge_val_t __huge_val = { __HUGE_VAL_bytes };
# define HUGE_VAL (__huge_val.__d)
#endif /* GCC. */
/* ISO C99 extensions: (float) HUGE_VALF and (long double) HUGE_VALL. */
#ifdef __USE_ISOC99
# ifdef __GNUC__
# if __GNUC_PREREQ(2,95)
# define HUGE_VALF (__extension__ 0x1.0p255f)
# else
# define HUGE_VALF \
(__extension__ \
((union { unsigned __l __attribute__((__mode__(__SI__))); float __d; }) \
{ __l: 0x7f800000UL }).__d)
# endif
# else /* not GCC */
typedef union { unsigned char __c[4]; float __f; } __huge_valf_t;
# if __BYTE_ORDER == __BIG_ENDIAN
# define __HUGE_VALF_bytes { 0x7f, 0x80, 0, 0 }
# endif
# if __BYTE_ORDER == __LITTLE_ENDIAN
# define __HUGE_VALF_bytes { 0, 0, 0x80, 0x7f }
# endif
static __huge_valf_t __huge_valf = { __HUGE_VALF_bytes };
# define HUGE_VALF (__huge_valf.__f)
# endif /* GCC. */
/* Generally there is no separate `long double' format and it is the
same as `double'. */
# define HUGE_VALL HUGE_VAL
#endif /* __USE_ISOC99. */
|
