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

/* */