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- /* `HUGE_VAL' constant for IEEE 754 machines (where it is infinity).
- Used by <stdlib.h> and <math.h> functions for overflow.
- Copyright (C) 1992-2016 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. */
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