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a86573f4 RH |
1 | /* `HUGE_VALL' constant for IEEE 754 machines (where it is infinity). |
2 | Used by <stdlib.h> and <math.h> functions for overflow. | |
3 | Copyright (C) 1992, 1995, 1996, 1997, 1999, 2000, 2004 | |
4 | Free Software Foundation, Inc. | |
5 | This file is part of the GNU C Library. | |
6 | ||
7 | The GNU C Library is free software; you can redistribute it and/or | |
8 | modify it under the terms of the GNU Lesser General Public | |
9 | License as published by the Free Software Foundation; either | |
10 | version 2.1 of the License, or (at your option) any later version. | |
11 | ||
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ | |
a86573f4 RH |
20 | |
21 | #ifndef _MATH_H | |
22 | # error "Never use <bits/huge_vall.h> directly; include <math.h> instead." | |
23 | #endif | |
24 | ||
25 | /* IEEE positive infinity (-HUGE_VAL is negative infinity). */ | |
26 | ||
27 | #if __GNUC_PREREQ(3,3) | |
28 | # define HUGE_VALL (__builtin_huge_vall()) | |
29 | #elif __GNUC_PREREQ(2,96) | |
30 | # define HUGE_VALL (__extension__ 0x1.0p32767L) | |
31 | #else | |
32 | # include <endian.h> | |
33 | ||
34 | typedef union { unsigned char __c[16]; long double __ld; } __huge_vall_t; | |
35 | ||
36 | # if __BYTE_ORDER == __BIG_ENDIAN | |
37 | # define __HUGE_VALL_bytes { 0x7f, 0xff, 0,0,0,0,0,0,0,0,0,0,0,0,0,0 } | |
38 | # endif | |
39 | # if __BYTE_ORDER == __LITTLE_ENDIAN | |
40 | # define __HUGE_VALL_bytes { 0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0xff, 0x7f } | |
41 | # endif | |
42 | ||
43 | # ifdef __GNUC__ | |
44 | # define HUGE_VALL (__extension__ \ | |
45 | ((__huge_vall_t) { __c : __HUGE_VALL_bytes }).__ld) | |
46 | # else | |
b33ed432 UD |
47 | static __huge_vall_t __huge_vall = { __HUGE_VALL_bytes }; |
48 | # define HUGE_VALL (__huge_vall.__ld) | |
a86573f4 RH |
49 | # endif |
50 | #endif |