mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 12:11:10 +00:00
54 lines
1.8 KiB
C
54 lines
1.8 KiB
C
/* `HUGE_VAL' constant for IEEE 754 machines (where it is infinity).
|
|
Used by <stdlib.h> and <math.h> functions for overflow.
|
|
Copyright (C) 1992-2013 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. */
|