sysdeps/ia64/bits/byteswap.h

   1 /* Macros to swap the order of bytes in integer values.
   2    Copyright (C) 1997, 1998, 2000 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #if !defined _BYTESWAP_H && !defined _NETINET_IN_H
  21 # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
  22 #endif
  23
  24 /* Swap bytes in 16 bit value.  */
  25 #define __bswap_constant_16(x) \
  26      ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
  27
  28 #if defined __GNUC__ && __GNUC__ >= 2
  29 # define __bswap_16(x) \
  30      (__extension__                                                           \
  31       ({ register unsigned short int __v;                                     \
  32          if (__builtin_constant_p (x))                                        \
  33            __v = __bswap_constant_16 (x);                                     \
  34          else                                                                 \
  35            __asm__ __volatile__ ("shl %0 = %1, 48 ;;"                         \
  36                                  "mux1 %0 = %2, @rev ;;"                      \
  37                                  : "=r" (__v)                                 \
  38                                  : "r" ((unsigned short int) (x)), "0" (__v));\
  39          __v; }))
  40 #else
  41 /* This is better than nothing.  */
  42 # define __bswap_16(x) __bswap_constant_16 (x)
  43 #endif
  44
  45
  46 /* Swap bytes in 32 bit value.  */
  47 #define __bswap_constant_32(x) \
  48      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |               \
  49       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
  50
  51 #if defined __GNUC__ && __GNUC__ >= 2
  52 # define __bswap_32(x) \
  53      (__extension__                                                           \
  54       ({ register unsigned int __v;                                           \
  55          if (__builtin_constant_p (x))                                        \
  56            __v = __bswap_constant_32 (x);                                     \
  57          else                                                                 \
  58            __asm__ __volatile__ ("shl %0 = %1, 32 ;;"                         \
  59                                  "mux1 %0 = %2, @rev ;;"                      \
  60                                  : "=r" (__v)                                 \
  61                                  : "r" ((unsigned int) (x)), "0" (__v));      \
  62          __v; }))
  63 #else
  64 # define __bswap_32(x) __bswap_constant_32 (x)
  65 #endif
  66
  67
  68 /* Swap bytes in 64 bit value.  */
  69 #define __bswap_constant_64(x) \
  70      ((((x) & 0xff00000000000000ul) >> 56)                                    \
  71       | (((x) & 0x00ff000000000000ul) >>  40)                                 \
  72       | (((x) & 0x0000ff0000000000ul) >> 24)                                  \
  73       | (((x) & 0x000000ff00000000ul) >> 8)                                   \
  74       | (((x) & 0x00000000ff000000ul) << 8)                                   \
  75       | (((x) & 0x0000000000ff0000ul) << 24)                                  \
  76       | (((x) & 0x000000000000ff00ul) << 40)                                  \
  77       | (((x) & 0x00000000000000fful) << 56))
  78
  79 #if defined __GNUC__ && __GNUC__ >= 2
  80 # define __bswap_64(x) \
  81      (__extension__                                                           \
  82       ({ register unsigned long int __v;                                      \
  83          if (__builtin_constant_p (x))                                        \
  84            __v = __bswap_constant_64 (x);                                     \
  85          else                                                                 \
  86            __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"                      \
  87                                  : "=r" (__v)                                 \
  88                                  : "r" ((unsigned long int) (x)));            \
  89          __v; }))
  90
  91 #else
  92 # define __bswap_64(x) __bswap_constant_64 (x)
  93 #endif