1/* Endian macros for string.h functions
2 Copyright (C) 1992-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _BITS_ENDIAN_H
20#define _BITS_ENDIAN_H 1
21
22/* Definitions for byte order, according to significance of bytes,
23 from low addresses to high addresses. The value is what you get by
24 putting '4' in the most significant byte, '3' in the second most
25 significant byte, '2' in the second least significant byte, and '1'
26 in the least significant byte, and then writing down one digit for
27 each byte, starting with the byte at the lowest address at the left,
28 and proceeding to the byte with the highest address at the right. */
29
30#define __LITTLE_ENDIAN 1234
31#define __BIG_ENDIAN 4321
32#define __PDP_ENDIAN 3412
33
34/* This file defines `__BYTE_ORDER' for the particular machine. */
35#include <bits/endianness.h>
36
37/* Some machines may need to use a different endianness for floating point
38 values. */
39#ifndef __FLOAT_WORD_ORDER
40# define __FLOAT_WORD_ORDER __BYTE_ORDER
41#endif
42
43#if __BYTE_ORDER == __LITTLE_ENDIAN
44# define __LONG_LONG_PAIR(HI, LO) LO, HI
45#elif __BYTE_ORDER == __BIG_ENDIAN
46# define __LONG_LONG_PAIR(HI, LO) HI, LO
47#endif
48
49#endif /* bits/endian.h */
50

source code of include/x86_64-linux-gnu/bits/endian.h