glibc/sysdeps/ia64/bits/byteswap-16.h

43 lines
1.6 KiB
C

/* Macros to swap the order of bytes in 16-bit integer values.
Copyright (C) 1997-2015 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
#if defined __GNUC__ && __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__ __volatile__ ("shl %0 = %1, 48 ;;" \
"mux1 %0 = %0, @rev ;;" \
: "=r" (__v) \
: "r" ((unsigned short int) (__x))); \
__v; }))
#else
/* This is better than nothing. */
static __inline unsigned short int
__bswap_16 (unsigned short int __bsx)
{
return __bswap_constant_16 (__bsx);
}
#endif