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endian.h revision 1.4 
      1 /*
      2  * Copyright (c) 1987, 1991 Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  *
     33  *	from: @(#)endian.h	7.8 (Berkeley) 4/3/91
     34  *	$Id: endian.h,v 1.4 1993/08/16 18:30:35 jtc Exp $
     35  */
     36 
     37 /*
     38  * Definitions for byte order, according to byte significance from low
     39  * address to high.
     40  */
     41 #define	LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
     42 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
     43 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
     44 
     45 #define	BYTE_ORDER	LITTLE_ENDIAN
     46 
     47 #ifndef KERNEL
     48 #include <sys/cdefs.h>
     49 #endif
     50 
     51 __BEGIN_DECLS
     52 unsigned long   htonl __P((unsigned long));
     53 unsigned short  htons __P((unsigned short));
     54 unsigned long   ntohl __P((unsigned long));
     55 unsigned short  ntohs __P((unsigned short));
     56 __END_DECLS
     57 
     58 
     59 #if __GNUC__
     60 #if __GNUC__ >= 2
     61 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     62 #define __byte_swap_long(x) \
     63 ({ register unsigned long X = (x); \
     64    asm ("bswap %1" \
     65 	: "=q" (X) \
     66 	: "0" (X)); \
     67    X; })
     68 #else
     69 #define __byte_swap_long(x) \
     70 ({ register unsigned long X = (x); \
     71    asm ("xchgb %h1, %b1\n\trorl $16, %1\n\txchgb %h1, %b1" \
     72 	: "=q" (X) \
     73 	: "0" (X)); \
     74    X; })
     75 #endif	/* KERNEL && ... */
     76 #define __byte_swap_word(x) \
     77 ({ register unsigned short X = (x); \
     78    asm ("xchgb %h1, %b1" \
     79 	: "=q" (X) \
     80 	: "0" (X)); \
     81    X; })
     82 #else	/* __GNUC__ >= 2 */
     83 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     84 #define __byte_swap_long(x) \
     85 ({ register unsigned long X = (x); \
     86    asm ("bswap %1" \
     87 	: "=r" (X) \
     88 	: "0" (X)); \
     89    X; })
     90 #else
     91 #define __byte_swap_long(x) \
     92 ({ register u_long X = (x); \
     93    asm ("rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" \
     94 	: "=r" (X) \
     95 	: "0" (X)); \
     96    X; })
     97 #endif	/* KERNEL && ... */
     98 #define __byte_swap_word(x) \
     99 ({ register u_short X = (x); \
    100    asm ("rorw $8, %w1" \
    101 	: "=r" (X) \
    102 	: "0" (X)); \
    103    X; })
    104 #endif	/* __GNUC__ >= 2 */
    105 
    106 #define	ntohl(x)	__byte_swap_long(x)
    107 #define	ntohs(x)	__byte_swap_word(x)
    108 #define	htonl(x)	__byte_swap_long(x)
    109 #define	htons(x)	__byte_swap_word(x)
    110 #endif	/* __GNUC__ */
    111 
    112 
    113 /*
    114  * Macros for network/external number representation conversion.
    115  */
    116 #if BYTE_ORDER == BIG_ENDIAN && !defined(lint)
    117 #define	ntohl(x)	(x)
    118 #define	ntohs(x)	(x)
    119 #define	htonl(x)	(x)
    120 #define	htons(x)	(x)
    121 
    122 #define	NTOHL(x)	(x)
    123 #define	NTOHS(x)	(x)
    124 #define	HTONL(x)	(x)
    125 #define	HTONS(x)	(x)
    126 
    127 #else
    128 
    129 #define	NTOHL(x)	(x) = ntohl((u_long)x)
    130 #define	NTOHS(x)	(x) = ntohs((u_short)x)
    131 #define	HTONL(x)	(x) = htonl((u_long)x)
    132 #define	HTONS(x)	(x) = htons((u_short)x)
    133 #endif
    134