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- /* Macros to swap the order of bytes in integer values.
- Copyright (C) 1997,1998,2000,2001,2002,2005 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
- # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
- #endif
- #ifndef _BITS_BYTESWAP_H
- #define _BITS_BYTESWAP_H 1
- /* Swap bytes in 16 bit value. */
- #define __bswap_constant_16(x) \
- ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))
- #ifndef __bswap_non_constant_16
- # define __bswap_non_constant_16(x) __bswap_constant_16(x)
- #endif
- #ifdef __GNUC__
- # define __bswap_16(x) \
- (__extension__ \
- ({ unsigned short int __bsv, __bsx = (x); \
- if (__builtin_constant_p (__bsx)) \
- __bsv = __bswap_constant_16 (__bsx); \
- else \
- __bsv = __bswap_non_constant_16 (__bsx); \
- __bsv; }))
- #else
- static __inline unsigned short int
- __bswap_16 (unsigned short int __bsx)
- {
- return __bswap_constant_16 (__bsx);
- }
- #endif
- /* Swap bytes in 32 bit value. */
- #define __bswap_constant_32(x) \
- ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \
- (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
- #ifndef __bswap_non_constant_32
- # define __bswap_non_constant_32(x) __bswap_constant_32(x)
- #endif
- #ifdef __GNUC__
- # define __bswap_32(x) \
- (__extension__ \
- ({ unsigned int __bsv, __bsx = (x); \
- if (__builtin_constant_p (__bsx)) \
- __bsv = __bswap_constant_32 (__bsx); \
- else \
- __bsv = __bswap_non_constant_32 (__bsx); \
- __bsv; }))
- #else
- static __inline unsigned int
- __bswap_32 (unsigned int __bsx)
- {
- return __bswap_constant_32 (__bsx);
- }
- #endif
- #if defined __GNUC__ && __GNUC__ >= 2
- /* Swap bytes in 64 bit value. */
- # 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))
- # ifndef __bswap_non_constant_64
- # define __bswap_non_constant_64(x) \
- (__extension__ \
- ({ union { __extension__ unsigned long long int __ll; \
- unsigned int __l[2]; } __w, __r; \
- __w.__ll = (x); \
- __r.__l[0] = __bswap_non_constant_32 (__w.__l[1]); \
- __r.__l[1] = __bswap_non_constant_32 (__w.__l[0]); \
- __r.__ll; }))
- # endif
- # define __bswap_64(x) \
- (__extension__ \
- ({ __extension__ unsigned long long int __ll; \
- if (__builtin_constant_p (x)) \
- __ll = __bswap_constant_64 (x); \
- else \
- __ll = __bswap_non_constant_64 (x); \
- __ll; }))
- #endif
- #endif /* _BITS_BYTESWAP_H */
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