libc/sysdeps/linux/nds32/bits/byteswap.h

   1 /*
   2  * Copyright (C) 2016 Andes Technology, Inc.
   3  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   4  */
   5
   6 /* Macros to swap the order of bytes in integer values.
   7    Copyright (C) 1997, 1998, 2000, 2002, 2003, 2006, 2007
   8    Free Software Foundation, Inc.
   9
  10    The GNU C Library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 2.1 of the License, or (at your option) any later version.
  14
  15    The GNU C Library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with the GNU C Library; if not, write to the Free
  22    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  23    02111-1307 USA.  */
  24
  25 #if !defined _BYTESWAP_H && !defined _NETINET_IN_H
  26 # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
  27 #endif
  28
  29 #ifndef _BITS_BYTESWAP_H
  30 #define _BITS_BYTESWAP_H 1
  31
  32 /* Swap bytes in 16 bit value.  */
  33 #define __bswap_constant_16(x) \
  34      ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
  35
  36 #ifdef __GNUC__
  37 # if __GNUC__ >= 2
  38 #  define __bswap_16(x) \
  39      (__extension__                                                           \
  40       ({ register unsigned short int __v, __x = (x);                          \
  41          if (__builtin_constant_p (__x))                                      \
  42            __v = __bswap_constant_16 (__x);                                   \
  43          else                                                                 \
  44            __asm__ ("wsbh       %0, %0\n\t"                               \
  45                     : "=r" (__v)                                              \
  46                     : "0" (__x));                                                 \
  47          __v; }))
  48 # else
  49 /* This is better than nothing.  */
  50 #  define __bswap_16(x) \
  51      (__extension__                                                           \
  52       ({ register unsigned short int __x = (x); __bswap_constant_16 (__x); }))
  53 # endif
  54 #else
  55 static __inline unsigned short int
  56 __bswap_16 (unsigned short int __bsx)
  57 {
  58   return __bswap_constant_16 (__bsx);
  59 }
  60 #endif
  61
  62 /* Swap bytes in 32 bit value.  */
  63 #define __bswap_constant_32(x) \
  64      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |               \
  65       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
  66
  67 #ifdef __GNUC__
  68 # if __GNUC__ >= 2
  69 #   define __bswap_32(x) \
  70      (__extension__                                                           \
  71       ({ register unsigned int __v, __x = (x);                                \
  72          if (__builtin_constant_p (__x))                                      \
  73            __v = __bswap_constant_32 (__x);                                   \
  74          else                                                                 \
  75            __asm__ ("wsbh       %0, %0\n\t"             \
  76                         "rotri  %0, %0, #16\n\t"        \
  77                         : "=r" (__v)                            \
  78                         : "0" (__x));                           \
  79          __v; }))
  80 # else
  81 #  define __bswap_32(x) \
  82      (__extension__                                                           \
  83       ({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
  84 # endif
  85 #else
  86 static __inline unsigned int
  87 __bswap_32 (unsigned int __bsx)
  88 {
  89   return __bswap_constant_32 (__bsx);
  90 }
  91 #endif
  92
  93
  94 #if defined __GNUC__ && __GNUC__ >= 2
  95 /* Swap bytes in 64 bit value.  */
  96 #define __bswap_constant_64(x) \
  97      ((((x) & 0xff00000000000000ull) >> 56)                                   \
  98       | (((x) & 0x00ff000000000000ull) >> 40)                                 \
  99       | (((x) & 0x0000ff0000000000ull) >> 24)                                 \
 100       | (((x) & 0x000000ff00000000ull) >> 8)                                  \
 101       | (((x) & 0x00000000ff000000ull) << 8)                                  \
 102       | (((x) & 0x0000000000ff0000ull) << 24)                                 \
 103       | (((x) & 0x000000000000ff00ull) << 40)                                 \
 104       | (((x) & 0x00000000000000ffull) << 56))
 105
 106 # define __bswap_64(x) \
 107      (__extension__                                                           \
 108       ({ union { __extension__ unsigned long long int __ll;                   \
 109                  unsigned long int __l[2]; } __w, __r;                        \
 110          if (__builtin_constant_p (x))                                        \
 111            __r.__ll = __bswap_constant_64 (x);                                \
 112          else                                                                 \
 113            {                                                                  \
 114              __w.__ll = (x);                                                  \
 115              __r.__l[0] = __bswap_32 (__w.__l[1]);                            \
 116              __r.__l[1] = __bswap_32 (__w.__l[0]);                            \
 117            }                                                                  \
 118          __r.__ll; }))
 119 #endif
 120
 121 #endif /* _BITS_BYTESWAP_H */