include/asm-x86/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 #ifdef __GNUC__
   8
   9 #ifdef __i386__
  10
  11 static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
  12 {
  13 #ifdef CONFIG_X86_BSWAP
  14         __asm__("bswap %0" : "=r" (x) : "0" (x));
  15 #else
  16         __asm__("xchgb %b0,%h0\n\t"     /* swap lower bytes     */
  17                 "rorl $16,%0\n\t"       /* swap words           */
  18                 "xchgb %b0,%h0"         /* swap higher bytes    */
  19                 :"=q" (x)
  20                 : "0" (x));
  21 #endif
  22         return x;
  23 }
  24
  25 static __inline__ __attribute_const__ __u64 ___arch__swab64(__u64 val)
  26 {
  27         union {
  28                 struct { __u32 a,b; } s;
  29                 __u64 u;
  30         } v;
  31         v.u = val;
  32 #ifdef CONFIG_X86_BSWAP
  33         __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
  34             : "=r" (v.s.a), "=r" (v.s.b)
  35             : "0" (v.s.a), "1" (v.s.b));
  36 #else
  37         v.s.a = ___arch__swab32(v.s.a);
  38         v.s.b = ___arch__swab32(v.s.b);
  39         __asm__("xchgl %0,%1" : "=r" (v.s.a), "=r" (v.s.b) : "0" (v.s.a), "1" (v.s.b));
  40 #endif
  41         return v.u;
  42 }
  43
  44 #else /* __i386__ */
  45
  46 static __inline__ __attribute_const__ __u64 ___arch__swab64(__u64 x)
  47 {
  48         __asm__("bswapq %0" : "=r" (x) : "0" (x));
  49         return x;
  50 }
  51
  52 static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
  53 {
  54         __asm__("bswapl %0" : "=r" (x) : "0" (x));
  55         return x;
  56 }
  57
  58 #endif
  59
  60 /* Do not define swab16.  Gcc is smart enough to recognize "C" version and
  61    convert it into rotation or exhange.  */
  62
  63 #define __arch__swab64(x) ___arch__swab64(x)
  64 #define __arch__swab32(x) ___arch__swab32(x)
  65
  66 #define __BYTEORDER_HAS_U64__
  67
  68 #endif /* __GNUC__ */
  69
  70 #include <linux/byteorder/little_endian.h>
  71
  72 #endif /* _ASM_X86_BYTEORDER_H */