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[/] [or1k/] [trunk/] [linux/] [uClibc/] [libc/] [sysdeps/] [linux/] [m68k/] [bits/] [byteswap.h] - Blame information for rev 1325

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1 1325 phoenix
/* Macros to swap the order of bytes in integer values.  m68k version.
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   Copyright (C) 1997, 2002 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, write to the Free
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   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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   02111-1307 USA.  */
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#if !defined _BYTESWAP_H && !defined _NETINET_IN_H
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# error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
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#endif
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#ifndef _BITS_BYTESWAP_H
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#define _BITS_BYTESWAP_H 1
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/* Swap bytes in 16 bit value.  We don't provide an assembler version
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   because GCC is smart enough to generate optimal assembler output, and
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   this allows for better cse.  */
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#define __bswap_16(x) \
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  ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
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/* Swap bytes in 32 bit value.  */
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#define __bswap_constant_32(x) \
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  ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) | \
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   (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
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#if defined __GNUC__ && __GNUC__ >= 2
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# define __bswap_32(x) \
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  __extension__                                                 \
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  ({ unsigned int __bswap_32_v;                                 \
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     if (__builtin_constant_p (x))                              \
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       __bswap_32_v = __bswap_constant_32 (x);                  \
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     else                                                       \
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       __asm__ __volatile__ ("ror%.w %#8, %0;"                  \
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                             "swap %0;"                         \
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                             "ror%.w %#8, %0"                   \
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                             : "=d" (__bswap_32_v)              \
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                             : "0" ((unsigned int) (x)));        \
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     __bswap_32_v; })
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#else
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# define __bswap_32(x) __bswap_constant_32 (x)
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#endif
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#if defined __GNUC__ && __GNUC__ >= 2
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/* Swap bytes in 64 bit value.  */
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# define __bswap_64(x) \
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  __extension__                                                         \
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  ({ union { unsigned long long int __ll;                               \
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             unsigned long int __l[2]; } __bswap_64_v, __bswap_64_r;    \
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     __bswap_64_v.__ll = (x);                                           \
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     __bswap_64_r.__l[0] = __bswap_32 (__bswap_64_v.__l[1]);             \
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     __bswap_64_r.__l[1] = __bswap_32 (__bswap_64_v.__l[0]);             \
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     __bswap_64_r.__ll; })
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#endif
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#endif /* _BITS_BYTESWAP_H */

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