utils/bswap.h

   1 /*
   2  * Lame bswap replacements as we can't assume the host is sane and provides
   3  * working versions of these.
   4  */
   5
   6 #ifndef _BSWAP_H
   7 #define _BSWAP_H 1
   8
   9 #ifdef __linux__
  10 # include <byteswap.h>
  11 #else
  12
  13 static __inline__ uint16_t bswap_16(uint16_t x)
  14 {
  15         return ((((x) & 0xff00) >> 8) | \
  16                 (((x) & 0x00ff) << 8));
  17 }
  18 static __inline__ uint32_t bswap_32(uint32_t x)
  19 {
  20         return ((((x) & 0xff000000) >> 24) | \
  21                 (((x) & 0x00ff0000) >>  8) | \
  22                 (((x) & 0x0000ff00) <<  8) | \
  23                 (((x) & 0x000000ff) << 24));
  24 }
  25 static __inline__ uint64_t bswap_64(uint64_t x)
  26 {
  27 #define _uswap_64(x, sfx) \
  28         return ((((x) & 0xff00000000000000##sfx) >> 56) | \
  29                 (((x) & 0x00ff000000000000##sfx) >> 40) | \
  30                 (((x) & 0x0000ff0000000000##sfx) >> 24) | \
  31                 (((x) & 0x000000ff00000000##sfx) >>  8) | \
  32                 (((x) & 0x00000000ff000000##sfx) <<  8) | \
  33                 (((x) & 0x0000000000ff0000##sfx) << 24) | \
  34                 (((x) & 0x000000000000ff00##sfx) << 40) | \
  35                 (((x) & 0x00000000000000ff##sfx) << 56));
  36 #if defined(__GNUC__)
  37         _uswap_64(x, ull)
  38 #else
  39         _uswap_64(x, )
  40 #endif
  41 #undef _uswap_64
  42 }
  43 #endif
  44
  45 #endif