osfmk/i386/endian.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  *
  33  */
  34
  35 #ifndef _MACHINE_ENDIAN_H_
  36 #define _MACHINE_ENDIAN_H_
  37
  38 /*
  39  * Definitions for byte order,
  40  * according to byte significance from low address to high.
  41  */
  42 #define LITTLE_ENDIAN   1234    /* least-significant byte first (vax) */
  43 #define BIG_ENDIAN      4321    /* most-significant byte first (IBM, net) */
  44 #define PDP_ENDIAN      3412    /* LSB first in word, MSW first in long (pdp) */
  45
  46 #define BYTE_ORDER      LITTLE_ENDIAN   /* byte order on i386 */
  47 #define ENDIAN          LITTLE
  48
  49 /*
  50  * Macros for network/external number representation conversion.
  51  * Use GNUC support to inline the byteswappers.
  52  */
  53
  54 #if !defined(ntohs)
  55 unsigned short  ntohs(unsigned short);
  56 extern __inline__
  57 unsigned short
  58 ntohs(unsigned short w_int)
  59 {
  60         register unsigned short w = w_int;
  61         __asm__ volatile("xchgb %h1,%b1" : "=q" (w) : "0" (w));
  62         return (w);     /* zero-extend for compat */
  63 }
  64 #endif
  65
  66 #if !defined(htons)
  67 unsigned short  htons(unsigned short);
  68 #define htons   ntohs
  69 #endif
  70
  71 #if !defined(ntohl)
  72 unsigned long   ntohl(unsigned long);
  73 extern __inline__
  74 unsigned long
  75 ntohl(register unsigned long value)
  76 {
  77         register unsigned long l = value;
  78         __asm__ volatile("bswap %0" : "=r" (l) : "0" (l));
  79         return l;
  80 }
  81 #endif
  82
  83 #if !defined(htonl)
  84 unsigned long   htonl(unsigned long);
  85 #define htonl   ntohl
  86 #endif
  87
  88 #define NTOHL(x)        (x) = ntohl((unsigned long)x)
  89 #define NTOHS(x)        (x) = ntohs((unsigned short)x)
  90 #define HTONL(x)        (x) = htonl((unsigned long)x)
  91 #define HTONS(x)        (x) = htons((unsigned short)x)
  92
  93 #endif