/* `HUGE_VAL' constant 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, 2004 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. */