1/* Macros to swap the order of bytes in 16-bit integer values.
2 Copyright (C) 2012-2014 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_BYTESWAP_H
20# error "Never use <bits/byteswap-16.h> directly; include <byteswap.h> instead."
21#endif
22
23#ifdef __GNUC__
24# if __GNUC__ >= 2
25# define __bswap_16(x) \
26 (__extension__ \
27 ({ unsigned short int __v, __x = (unsigned short int) (x); \
28 if (__builtin_constant_p (__x)) \
29 __v = __bswap_constant_16 (__x); \
30 else \
31 __asm__ ("rorw $8, %w0" \
32 : "=r" (__v) \
33 : "0" (__x) \
34 : "cc"); \
35 __v; }))
36# else
37/* This is better than nothing. */
38# define __bswap_16(x) \
39 (__extension__ \
40 ({ unsigned short int __x = (unsigned short int) (x); \
41 __bswap_constant_16 (__x); }))
42# endif
43#else
44static __inline unsigned short int
45__bswap_16 (unsigned short int __bsx)
46{
47 return __bswap_constant_16 (__bsx);
48}
49#endif
50