root/include/asm-i386/byteorder.h

/* */

INCLUDED FROM

DEFINITIONS

1. __ntohl
2. __ntohs

   1 #ifndef _I386_BYTEORDER_H
   2 #define _I386_BYTEORDER_H
   3 
   4 #undef ntohl
   5 #undef ntohs
   6 #undef htonl
   7 #undef htons
   8 
   9 #define LITTLE_ENDIAN 1234
  10 #define LITTLE_ENDIAN_BITFIELD
  11 
  12 extern unsigned long int        ntohl(unsigned long int);
  13 extern unsigned short int       ntohs(unsigned short int);
  14 extern unsigned long int        htonl(unsigned long int);
  15 extern unsigned short int       htons(unsigned short int);
  16 
  17 extern unsigned long int        __ntohl(unsigned long int);
  18 extern unsigned short int       __ntohs(unsigned short int);
  19 extern unsigned long int        __constant_ntohl(unsigned long int);
  20 extern unsigned short int       __constant_ntohs(unsigned short int);
  21 
  22 extern __inline__ unsigned long int
  23 __ntohl(unsigned long int x)
     /*  */
  24 {
  25         __asm__("xchgb %b0,%h0\n\t"     /* swap lower bytes     */
  26                 "rorl $16,%0\n\t"       /* swap words           */
  27                 "xchgb %b0,%h0"         /* swap higher bytes    */
  28                 :"=q" (x)
  29                 : "0" (x));
  30         return x;
  31 }
  32 
  33 #define __constant_ntohl(x) \
  34         ((unsigned long int)((((unsigned long int)(x) & 0x000000ffU) << 24) | \
  35                              (((unsigned long int)(x) & 0x0000ff00U) <<  8) | \
  36                              (((unsigned long int)(x) & 0x00ff0000U) >>  8) | \
  37                              (((unsigned long int)(x) & 0xff000000U) >> 24)))
  38 
  39 extern __inline__ unsigned short int
  40 __ntohs(unsigned short int x)
     /*  */
  41 {
  42         __asm__("xchgb %b0,%h0"         /* swap bytes           */
  43                 : "=q" (x)
  44                 :  "0" (x));
  45         return x;
  46 }
  47 
  48 #define __constant_ntohs(x) \
  49         ((unsigned short int)((((unsigned short int)(x) & 0x00ff) << 8) | \
  50                               (((unsigned short int)(x) & 0xff00) >> 8))) \
  51 
  52 #define __htonl(x) __ntohl(x)
  53 #define __htons(x) __ntohs(x)
  54 #define __constant_htonl(x) __constant_ntohl(x)
  55 #define __constant_htons(x) __constant_ntohs(x)
  56 
  57 #ifdef  __OPTIMIZE__
  58 #  define ntohl(x) \
  59 (__builtin_constant_p((long)(x)) ? \
  60  __constant_ntohl((x)) : \
  61  __ntohl((x)))
  62 #  define ntohs(x) \
  63 (__builtin_constant_p((short)(x)) ? \
  64  __constant_ntohs((x)) : \
  65  __ntohs((x)))
  66 #  define htonl(x) \
  67 (__builtin_constant_p((long)(x)) ? \
  68  __constant_htonl((x)) : \
  69  __htonl((x)))
  70 #  define htons(x) \
  71 (__builtin_constant_p((short)(x)) ? \
  72  __constant_htons((x)) : \
  73  __htons((x)))
  74 #endif
  75 
  76 #endif

/* */