| 1 | /* `HUGE_VAL' constant for IEEE 754 machines (where it is infinity). |
|---|
| 2 | Used by <stdlib.h> and <math.h> functions for overflow. |
|---|
| 3 | Copyright (C) 1992-2016 Free Software Foundation, Inc. |
|---|
| 4 | This file is part of the GNU C Library. |
|---|
| 5 | |
|---|
| 6 | The GNU C Library is free software; you can redistribute it and/or |
|---|
| 7 | modify it under the terms of the GNU Lesser General Public |
|---|
| 8 | License as published by the Free Software Foundation; either |
|---|
| 9 | version 2.1 of the License, or (at your option) any later version. |
|---|
| 10 | |
|---|
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
|---|
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
|---|
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|---|
| 14 | Lesser General Public License for more details. |
|---|
| 15 | |
|---|
| 16 | You should have received a copy of the GNU Lesser General Public |
|---|
| 17 | License along with the GNU C Library; if not, see |
|---|
| 18 | <http://www.gnu.org/licenses/>. */ |
|---|
| 19 | |
|---|
| 20 | #ifndef _MATH_H |
|---|
| 21 | # error "Never use <bits/huge_val.h> directly; include <math.h> instead." |
|---|
| 22 | #endif |
|---|
| 23 | |
|---|
| 24 | /* IEEE positive infinity (-HUGE_VAL is negative infinity). */ |
|---|
| 25 | |
|---|
| 26 | #if __GNUC_PREREQ(3,3) |
|---|
| 27 | # define HUGE_VAL (__builtin_huge_val()) |
|---|
| 28 | #elif __GNUC_PREREQ(2,96) |
|---|
| 29 | # define HUGE_VAL (__extension__ 0x1.0p2047) |
|---|
| 30 | #elif defined __GNUC__ |
|---|
| 31 | |
|---|
| 32 | # define HUGE_VAL \ |
|---|
| 33 | (__extension__ \ |
|---|
| 34 | ((union { unsigned __l __attribute__((__mode__(__DI__))); double __d; }) \ |
|---|
| 35 | { __l: 0x7ff0000000000000ULL }).__d) |
|---|
| 36 | |
|---|
| 37 | #else /* not GCC */ |
|---|
| 38 | |
|---|
| 39 | # include <endian.h> |
|---|
| 40 | |
|---|
| 41 | typedef union { unsigned char __c[8]; double __d; } __huge_val_t; |
|---|
| 42 | |
|---|
| 43 | # if __BYTE_ORDER == __BIG_ENDIAN |
|---|
| 44 | # define __HUGE_VAL_bytes { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 } |
|---|
| 45 | # endif |
|---|
| 46 | # if __BYTE_ORDER == __LITTLE_ENDIAN |
|---|
| 47 | # define __HUGE_VAL_bytes { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f } |
|---|
| 48 | # endif |
|---|
| 49 | |
|---|
| 50 | static __huge_val_t __huge_val = { __HUGE_VAL_bytes }; |
|---|
| 51 | # define HUGE_VAL (__huge_val.__d) |
|---|
| 52 | |
|---|
| 53 | #endif /* GCC. */ |
|---|
| 54 | |
|---|