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
|
/* `HUGE_VAL' constant for IEEE 754 machines (where it is infinity).
Used by <stdlib.h> and <math.h> functions for overflow.
Copyright (C) 1992-2017 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 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 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _MATH_H
# error "Never use <bits/huge_val.h> directly; include <math.h> instead."
#endif
/* IEEE positive infinity (-HUGE_VAL is negative infinity). */
#if __GNUC_PREREQ(3,3)
# define HUGE_VAL (__builtin_huge_val())
#elif __GNUC_PREREQ(2,96)
# define HUGE_VAL (__extension__ 0x1.0p2047)
#elif defined __GNUC__
# define HUGE_VAL \
(__extension__ \
((union { unsigned __l __attribute__((__mode__(__DI__))); double __d; }) \
{ __l: 0x7ff0000000000000ULL }).__d)
#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. */
|
