sysdeps/m68k/bits/byteswap.h

   1 /* Macros to swap the order of bytes in integer values.  m68k version.
   2    Copyright (C) 1997, 2002, 2008, 2011 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
  21 # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
  22 #endif
  23
  24 #ifndef _BITS_BYTESWAP_H
  25 #define _BITS_BYTESWAP_H 1
  26
  27 /* Swap bytes in 16 bit value.  We don't provide an assembler version
  28    because GCC is smart enough to generate optimal assembler output, and
  29    this allows for better cse.  */
  30 #define __bswap_constant_16(x) \
  31   ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))
  32
  33 static __inline unsigned short int
  34 __bswap_16 (unsigned short int __bsx)
  35 {
  36   return __bswap_constant_16 (__bsx);
  37 }
  38
  39 /* Swap bytes in 32 bit value.  */
  40 #define __bswap_constant_32(x) \
  41   ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >>  8) |                \
  42    (((x) & 0x0000ff00u) <<  8) | (((x) & 0x000000ffu) << 24))
  43
  44 #if !defined(__mcoldfire__)
  45 static __inline unsigned int
  46 __bswap_32 (unsigned int __bsx)
  47 {
  48   if (__builtin_constant_p (__bsx))
  49     return __bswap_constant_32 (__bsx);
  50   __asm__ __volatile__ ("ror%.w %#8, %0;"
  51                         "swap %0;"
  52                         "ror%.w %#8, %0"
  53                         : "+d" (__bsx));
  54   return __bsx;
  55 }
  56 #else
  57 static __inline unsigned int
  58 __bswap_32 (unsigned int __bsx)
  59 {
  60   return __bswap_constant_32 (__bsx);
  61 }
  62 #endif
  63
  64 #if defined __GNUC__ && __GNUC__ >= 2
  65 /* Swap bytes in 64 bit value.  */
  66 # define __bswap_constant_64(x) \
  67   __extension__                                                               \
  68   ((((x) & 0xff00000000000000ull) >> 56)                                      \
  69    | (((x) & 0x00ff000000000000ull) >> 40)                                    \
  70    | (((x) & 0x0000ff0000000000ull) >> 24)                                    \
  71    | (((x) & 0x000000ff00000000ull) >> 8)                                     \
  72    | (((x) & 0x00000000ff000000ull) << 8)                                     \
  73    | (((x) & 0x0000000000ff0000ull) << 24)                                    \
  74    | (((x) & 0x000000000000ff00ull) << 40)                                    \
  75    | (((x) & 0x00000000000000ffull) << 56))
  76
  77 /* Swap bytes in 64 bit value.  */
  78 static __inline unsigned long long
  79 __bswap_64 (unsigned long long __bsx)
  80 {
  81   if (__builtin_constant_p (__bsx))
  82     return __bswap_constant_64 (__bsx);
  83   return (__bswap_32 (__bsx >> 32)
  84           | ((unsigned long long) __bswap_32 (__bsx) << 32));
  85 }
  86 #endif
  87
  88 #endif /* _BITS_BYTESWAP_H */