Elep

/* Macros to swap the order of bytes in 16-bit integer values.
   Copyright (C) 2012 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 _BITS_BYTESWAP_H
# error "Never use <bits/byteswap-16.h> directly; include <byteswap.h> 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