sysdeps/ia64/bits/byteswap.h

   1 /* Macros to swap the order of bytes in integer values.
   2    Copyright (C) 1997,1998,2000,2002,2003,2008 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.  */
  28 #define __bswap_constant_16(x) \
  29      ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
  30
  31 #if defined __GNUC__ && __GNUC__ >= 2
  32 # define __bswap_16(x) \
  33      (__extension__                                                           \
  34       ({ register unsigned short int __v, __x = (x);                          \
  35          if (__builtin_constant_p (x))                                        \
  36            __v = __bswap_constant_16 (__x);                                   \
  37          else                                                                 \
  38            __asm__ __volatile__ ("shl %0 = %1, 48 ;;"                         \
  39                                  "mux1 %0 = %0, @rev ;;"                      \
  40                                  : "=r" (__v)                                 \
  41                                  : "r" ((unsigned short int) (__x)));         \
  42          __v; }))
  43 #else
  44 /* This is better than nothing.  */
  45 static __inline unsigned short int
  46 __bswap_16 (unsigned short int __bsx)
  47 {
  48   return __bswap_constant_16 (__bsx);
  49 }
  50 #endif
  51
  52
  53 /* Swap bytes in 32 bit value.  */
  54 #define __bswap_constant_32(x) \
  55      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |               \
  56       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
  57
  58 #if defined __GNUC__ && __GNUC__ >= 2
  59 # define __bswap_32(x) \
  60      (__extension__                                                           \
  61       ({ register unsigned int __v, __x = (x);                                \
  62          if (__builtin_constant_p (x))                                        \
  63            __v = __bswap_constant_32 (__x);                                   \
  64          else                                                                 \
  65            __asm__ __volatile__ ("shl %0 = %1, 32 ;;"                         \
  66                                  "mux1 %0 = %0, @rev ;;"                      \
  67                                  : "=r" (__v)                                 \
  68                                  : "r" ((unsigned int) (__x)));               \
  69          __v; }))
  70 #else
  71 static __inline unsigned int
  72 __bswap_32 (unsigned int __bsx)
  73 {
  74   return __bswap_constant_32 (__bsx);
  75 }
  76 #endif
  77
  78
  79 /* Swap bytes in 64 bit value.  */
  80 #define __bswap_constant_64(x) \
  81      ((((x) & 0xff00000000000000ul) >> 56)                                    \
  82       | (((x) & 0x00ff000000000000ul) >>  40)                                 \
  83       | (((x) & 0x0000ff0000000000ul) >> 24)                                  \
  84       | (((x) & 0x000000ff00000000ul) >> 8)                                   \
  85       | (((x) & 0x00000000ff000000ul) << 8)                                   \
  86       | (((x) & 0x0000000000ff0000ul) << 24)                                  \
  87       | (((x) & 0x000000000000ff00ul) << 40)                                  \
  88       | (((x) & 0x00000000000000fful) << 56))
  89
  90 #if defined __GNUC__ && __GNUC__ >= 2
  91 # define __bswap_64(x) \
  92      (__extension__                                                           \
  93       ({ register unsigned long int __v, __x = (x);                           \
  94          if (__builtin_constant_p (x))                                        \
  95            __v = __bswap_constant_64 (__x);                                   \
  96          else                                                                 \
  97            __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"                      \
  98                                  : "=r" (__v)                                 \
  99                                  : "r" ((unsigned long int) (__x)));          \
 100          __v; }))
 101
 102 #else
 103 static __inline unsigned long int
 104 __bswap_64 (unsigned long int __bsx)
 105 {
 106   return __bswap_constant_64 (__bsx);
 107 }
 108 #endif
 109
 110 #endif /* _BITS_BYTESWAP_H */