osfmk/i386/endian.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  *
  26  */
  27
  28 #ifndef _MACHINE_ENDIAN_H_
  29 #define _MACHINE_ENDIAN_H_
  30
  31 /*
  32  * Definitions for byte order,
  33  * according to byte significance from low address to high.
  34  */
  35 #define LITTLE_ENDIAN   1234    /* least-significant byte first (vax) */
  36 #define BIG_ENDIAN      4321    /* most-significant byte first (IBM, net) */
  37 #define PDP_ENDIAN      3412    /* LSB first in word, MSW first in long (pdp) */
  38
  39 #define BYTE_ORDER      LITTLE_ENDIAN   /* byte order on i386 */
  40 #define ENDIAN          LITTLE
  41
  42 /*
  43  * Macros for network/external number representation conversion.
  44  * Use GNUC support to inline the byteswappers.
  45  */
  46
  47 #if !defined(ntohs)
  48 unsigned short  ntohs(unsigned short);
  49 extern __inline__
  50 unsigned short
  51 ntohs(unsigned short w_int)
  52 {
  53         register unsigned short w = w_int;
  54         __asm__ volatile("xchgb %h1,%b1" : "=q" (w) : "0" (w));
  55         return (w);     /* zero-extend for compat */
  56 }
  57 #endif
  58
  59 #if !defined(htons)
  60 unsigned short  htons(unsigned short);
  61 #define htons   ntohs
  62 #endif
  63
  64 #if !defined(ntohl)
  65 unsigned long   ntohl(unsigned long);
  66 extern __inline__
  67 unsigned long
  68 ntohl(register unsigned long value)
  69 {
  70         register unsigned long l = value;
  71         __asm__ volatile("bswap %0" : "=r" (l) : "0" (l));
  72         return l;
  73 }
  74 #endif
  75
  76 #if !defined(htonl)
  77 unsigned long   htonl(unsigned long);
  78 #define htonl   ntohl
  79 #endif
  80
  81 #define NTOHL(x)        (x) = ntohl((unsigned long)x)
  82 #define NTOHS(x)        (x) = ntohs((unsigned short)x)
  83 #define HTONL(x)        (x) = htonl((unsigned long)x)
  84 #define HTONS(x)        (x) = htons((unsigned short)x)
  85
  86 #endif