mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 09:01:07 +00:00
112 lines
3.7 KiB
C
112 lines
3.7 KiB
C
/* Macros to swap the order of bytes in integer values.
|
|
Copyright (C) 1997-2012 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/>. */
|
|
|
|
#if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
|
|
# error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
|
|
#endif
|
|
|
|
#ifndef _BITS_BYTESWAP_H
|
|
#define _BITS_BYTESWAP_H 1
|
|
|
|
#include <features.h>
|
|
|
|
/* Swap bytes in 16 bit value. */
|
|
#define __bswap_constant_16(x) \
|
|
((unsigned short int)((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
|
|
|
|
/* Get __bswap_16. */
|
|
#include <bits/byteswap-16.h>
|
|
|
|
/* Swap bytes in 32 bit value. */
|
|
#define __bswap_constant_32(x) \
|
|
((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \
|
|
(((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
|
|
|
|
#ifdef __GNUC__
|
|
# if __GNUC_PREREQ (4, 2)
|
|
static __inline unsigned int
|
|
__bswap_32 (unsigned int __bsx)
|
|
{
|
|
return __builtin_bswap32 (__bsx);
|
|
}
|
|
# else
|
|
# define __bswap_32(x) \
|
|
(__extension__ \
|
|
({ register unsigned int __bsx = (x); __bswap_constant_32 (__bsx); }))
|
|
# endif
|
|
#else
|
|
static __inline unsigned int
|
|
__bswap_32 (unsigned int __bsx)
|
|
{
|
|
return __bswap_constant_32 (__bsx);
|
|
}
|
|
#endif
|
|
|
|
/* Swap bytes in 64 bit value. */
|
|
#if __GNUC_PREREQ (2, 0)
|
|
# define __bswap_constant_64(x) \
|
|
(__extension__ ((((x) & 0xff00000000000000ull) >> 56) \
|
|
| (((x) & 0x00ff000000000000ull) >> 40) \
|
|
| (((x) & 0x0000ff0000000000ull) >> 24) \
|
|
| (((x) & 0x000000ff00000000ull) >> 8) \
|
|
| (((x) & 0x00000000ff000000ull) << 8) \
|
|
| (((x) & 0x0000000000ff0000ull) << 24) \
|
|
| (((x) & 0x000000000000ff00ull) << 40) \
|
|
| (((x) & 0x00000000000000ffull) << 56)))
|
|
|
|
# if __GNUC_PREREQ (4, 2)
|
|
static __inline unsigned long long int
|
|
__bswap_64 (unsigned long long int __bsx)
|
|
{
|
|
return __builtin_bswap64 (__bsx);
|
|
}
|
|
# else
|
|
# define __bswap_64(x) \
|
|
(__extension__ \
|
|
({ union { __extension__ unsigned long long int __ll; \
|
|
unsigned int __l[2]; } __w, __r; \
|
|
if (__builtin_constant_p (x)) \
|
|
__r.__ll = __bswap_constant_64 (x); \
|
|
else \
|
|
{ \
|
|
__w.__ll = (x); \
|
|
__r.__l[0] = __bswap_32 (__w.__l[1]); \
|
|
__r.__l[1] = __bswap_32 (__w.__l[0]); \
|
|
} \
|
|
__r.__ll; }))
|
|
# endif
|
|
#elif __GLIBC_HAVE_LONG_LONG
|
|
# define __bswap_constant_64(x) \
|
|
((((x) & 0xff00000000000000ull) >> 56) \
|
|
| (((x) & 0x00ff000000000000ull) >> 40) \
|
|
| (((x) & 0x0000ff0000000000ull) >> 24) \
|
|
| (((x) & 0x000000ff00000000ull) >> 8) \
|
|
| (((x) & 0x00000000ff000000ull) << 8) \
|
|
| (((x) & 0x0000000000ff0000ull) << 24) \
|
|
| (((x) & 0x000000000000ff00ull) << 40) \
|
|
| (((x) & 0x00000000000000ffull) << 56))
|
|
|
|
static __inline unsigned long long int
|
|
__bswap_64 (unsigned long long int __bsx)
|
|
{
|
|
return __bswap_constant_64 (__bsx);
|
|
}
|
|
#endif
|
|
|
|
#endif /* _BITS_BYTESWAP_H */
|