endianness.h

   1 /*
   2  * Endianness.h
   3  *
   4  * Created on: 29.11.2010
   5  *
   6  * author: rofl0r
   7  *
   8  * License: Public Domain
   9  *
  10  */
  11
  12 #ifndef ENDIANNESS_H_
  13 #define ENDIANNESS_H_
  14
  15 #ifdef __linux
  16 #include <endian.h>
  17 #else
  18 #include <machine/endian.h>
  19 #endif
  20
  21 #if (!defined(__BYTE_ORDER)) && (!defined(BYTE_ORDER))
  22 #error "no __BYTE_ORDER macro found!"
  23 #endif
  24
  25 #ifndef __BYTE_ORDER
  26 #define __BYTE_ORDER BYTE_ORDER
  27 #endif
  28
  29 #if (!defined(__LITTLE_ENDIAN)) && (!defined(LITTLE_ENDIAN))
  30 #error "no __LITTLE_ENDIAN macro found!"
  31 #endif
  32
  33 #ifndef __LITTLE_ENDIAN
  34 #define __LITTLE_ENDIAN LITTLE_ENDIAN
  35 #define __BIG_ENDIAN BIG_ENDIAN
  36 #endif
  37
  38
  39 #if __BYTE_ORDER == __LITTLE_ENDIAN
  40 #define IS_LITTLE_ENDIAN
  41 #endif
  42
  43 #define byteswap16(x) (((x) & 0x00ff) << 8 | ((x) & 0xff00) >> 8)
  44
  45 #define byteswap32(x) \
  46      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) | \
  47       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
  48
  49 #include <stdint.h>
  50 static inline uint64_t byteswap64(uint64_t x) {
  51         union {
  52                 uint64_t ll;
  53                 uint32_t l[2];
  54         } w, r;
  55         w.ll = x;
  56         r.l[0] = byteswap32 (w.l[1]);
  57         r.l[1] = byteswap32 (w.l[0]);
  58         return r.ll;
  59 }
  60
  61 #ifdef IS_LITTLE_ENDIAN
  62 #define le32(X) (X)
  63 #define le16(X) (X)
  64 #else
  65 #define le32(X) byteswap32(X)
  66 #define le16(X) byteswap16(X)
  67 #endif
  68
  69 #endif /* ENDIANNESS_H_ */