lib/libstand/bswap.c

   1 /*
   2  * Written by Manuel Bouyer <bouyer@netbsd.org>.
   3  * Public domain.
   4  *
   5  * $NetBSD: bswap32.c,v 1.1 1997/10/09 15:42:33 bouyer Exp $
   6  * $NetBSD: bswap64.c,v 1.1 1997/10/09 15:42:33 bouyer Exp $
   7  * $DragonFly: src/lib/libstand/bswap.c,v 1.3 2005/12/11 02:27:26 swildner Exp $
   8  */
   9
  10 #include <sys/types.h>
  11
  12 #undef bswap32
  13 #undef bswap64
  14
  15 u_int32_t
  16 bswap32(u_int32_t x)
  17 {
  18         return  ((x << 24) & 0xff000000 ) |
  19                         ((x <<  8) & 0x00ff0000 ) |
  20                         ((x >>  8) & 0x0000ff00 ) |
  21                         ((x >> 24) & 0x000000ff );
  22 }
  23
  24 u_int64_t
  25 bswap64(u_int64_t x)
  26 {
  27         u_int32_t *p = (u_int32_t*)&x;
  28         u_int32_t t;
  29         t = bswap32(p[0]);
  30         p[0] = bswap32(p[1]);
  31         p[1] = t;
  32         return x;
  33 }