/* Macros to swap the order of bytes in 16-bit integer values. Copyright (C) 2012-2016 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 . */ #ifndef _BITS_BYTESWAP_H # error "Never use directly; include instead." #endif #ifdef __GNUC__ # if __GNUC__ >= 2 # define __bswap_16(x) \ (__extension__ \ ({ unsigned short int __v, __x = (unsigned short int) (x); \ if (__builtin_constant_p (__x)) \ __v = __bswap_constant_16 (__x); \ else \ __asm__ ("rorw $8, %w0" \ : "=r" (__v) \ : "0" (__x) \ : "cc"); \ __v; })) # else /* This is better than nothing. */ # define __bswap_16(x) \ (__extension__ \ ({ unsigned short int __x = (unsigned short int) (x); \ __bswap_constant_16 (__x); })) # endif #else static __inline unsigned short int __bswap_16 (unsigned short int __bsx) { return __bswap_constant_16 (__bsx); } #endif