arch/x86/include/asm/byteorder.h

   1 #ifndef _ASM_X86_BYTEORDER_H
   2 #define _ASM_X86_BYTEORDER_H
   3
   4 #include <asm/types.h>
   5 #include <linux/compiler.h>
   6
   7 #define __LITTLE_ENDIAN
   8
   9 static inline __attribute_const__ __u32 __arch_swab32(__u32 val)
  10 {
  11 #ifdef __i386__
  12 # ifdef CONFIG_X86_BSWAP
  13         asm("bswap %0" : "=r" (val) : "0" (val));
  14 # else
  15         asm("xchgb %b0,%h0\n\t" /* swap lower bytes     */
  16             "rorl $16,%0\n\t"   /* swap words           */
  17             "xchgb %b0,%h0"     /* swap higher bytes    */
  18             : "=q" (val)
  19             : "0" (val));
  20 # endif
  21
  22 #else /* __i386__ */
  23         asm("bswapl %0"
  24             : "=r" (val)
  25             : "0" (val));
  26 #endif
  27         return val;
  28 }
  29 #define __arch_swab32 __arch_swab32
  30
  31 static inline __attribute_const__ __u64 __arch_swab64(__u64 val)
  32 {
  33 #ifdef __i386__
  34         union {
  35                 struct {
  36                         __u32 a;
  37                         __u32 b;
  38                 } s;
  39                 __u64 u;
  40         } v;
  41         v.u = val;
  42 # ifdef CONFIG_X86_BSWAP
  43         asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
  44             : "=r" (v.s.a), "=r" (v.s.b)
  45             : "0" (v.s.a), "1" (v.s.b));
  46 # else
  47         v.s.a = __arch_swab32(v.s.a);
  48         v.s.b = __arch_swab32(v.s.b);
  49         asm("xchgl %0,%1"
  50             : "=r" (v.s.a), "=r" (v.s.b)
  51             : "0" (v.s.a), "1" (v.s.b));
  52 # endif
  53         return v.u;
  54 #else /* __i386__ */
  55         asm("bswapq %0"
  56             : "=r" (val)
  57             : "0" (val));
  58         return val;
  59 #endif
  60 }
  61 #define __arch_swab64 __arch_swab64
  62
  63 #include <linux/byteorder.h>
  64
  65 #endif /* _ASM_X86_BYTEORDER_H */