include/asm-i386/byteorder.h

   1 #ifndef _I386_BYTEORDER_H
   2 #define _I386_BYTEORDER_H
   3
   4 #include <asm/types.h>
   5 #include <linux/compiler.h>
   6
   7 #ifdef __GNUC__
   8
   9 /* For avoiding bswap on i386 */
  10 #ifdef __KERNEL__
  11 #endif
  12
  13 static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
  14 {
  15 #ifdef CONFIG_X86_BSWAP
  16         __asm__("bswap %0" : "=r" (x) : "0" (x));
  17 #else
  18         __asm__("xchgb %b0,%h0\n\t"     /* swap lower bytes     */
  19                 "rorl $16,%0\n\t"       /* swap words           */
  20                 "xchgb %b0,%h0"         /* swap higher bytes    */
  21                 :"=q" (x)
  22                 : "0" (x));
  23 #endif
  24         return x;
  25 }
  26
  27 static __inline__ __attribute_const__ __u64 ___arch__swab64(__u64 val)
  28 {
  29         union {
  30                 struct { __u32 a,b; } s;
  31                 __u64 u;
  32         } v;
  33         v.u = val;
  34 #ifdef CONFIG_X86_BSWAP
  35         asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
  36             : "=r" (v.s.a), "=r" (v.s.b)
  37             : "0" (v.s.a), "1" (v.s.b));
  38 #else
  39    v.s.a = ___arch__swab32(v.s.a);
  40         v.s.b = ___arch__swab32(v.s.b);
  41         asm("xchgl %0,%1" : "=r" (v.s.a), "=r" (v.s.b) : "0" (v.s.a), "1" (v.s.b));
  42 #endif
  43         return v.u;
  44 }
  45
  46 /* Do not define swab16.  Gcc is smart enough to recognize "C" version and
  47    convert it into rotation or exhange.  */
  48
  49 #define __arch__swab64(x) ___arch__swab64(x)
  50 #define __arch__swab32(x) ___arch__swab32(x)
  51
  52 #define __BYTEORDER_HAS_U64__
  53
  54 #endif /* __GNUC__ */
  55
  56 #include <linux/byteorder/little_endian.h>
  57
  58 #endif /* _I386_BYTEORDER_H */