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endian.h revision 1.8 
      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 1.8 1993/12/20 05:25:11 mycroft Exp $
     35  */
     36 
     37 #ifndef _MACHINE_ENDIAN_H_
     38 #define _MACHINE_ENDIAN_H_
     39 
     40 /*
     41  * Define the order of 32-bit words in 64-bit words.
     42  */
     43 #define _QUAD_HIGHWORD 1
     44 #define _QUAD_LOWWORD 0
     45 
     46 
     47 #ifndef _POSIX_SOURCE
     48 /*
     49  * Definitions for byte order, according to byte significance from low
     50  * address to high.
     51  */
     52 #define	LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
     53 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
     54 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
     55 
     56 #define	BYTE_ORDER	LITTLE_ENDIAN
     57 
     58 #include <sys/cdefs.h>
     59 
     60 __BEGIN_DECLS
     61 unsigned long   htonl __P((unsigned long));
     62 unsigned short  htons __P((unsigned short));
     63 unsigned long   ntohl __P((unsigned long));
     64 unsigned short  ntohs __P((unsigned short));
     65 __END_DECLS
     66 
     67 
     68 #ifdef __GNUC__
     69 
     70 #if __GNUC__ >= 2
     71 
     72 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     73 #define __byte_swap_long(x) \
     74 ({ register unsigned long X = (x); \
     75    asm ("bswap %1" \
     76 	: "=q" (X) \
     77 	: "0" (X)); \
     78    X; })
     79 #else
     80 #define __byte_swap_long(x) \
     81 ({ register unsigned long X = (x); \
     82    asm ("xchgb %h1, %b1\n\trorl $16, %1\n\txchgb %h1, %b1" \
     83 	: "=q" (X) \
     84 	: "0" (X)); \
     85    X; })
     86 #endif	/* KERNEL && ... */
     87 #define __byte_swap_word(x) \
     88 ({ register unsigned short X = (x); \
     89    asm ("xchgb %h1, %b1" \
     90 	: "=q" (X) \
     91 	: "0" (X)); \
     92    X; })
     93 
     94 #else	/* __GNUC__ >= 2 */
     95 
     96 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     97 #define __byte_swap_long(x) \
     98 ({ register unsigned long X = (x); \
     99    asm ("bswap %1" \
    100 	: "=r" (X) \
    101 	: "0" (X)); \
    102    X; })
    103 #else
    104 #define __byte_swap_long(x) \
    105 ({ register u_long X = (x); \
    106    asm ("rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" \
    107 	: "=r" (X) \
    108 	: "0" (X)); \
    109    X; })
    110 #endif	/* KERNEL && ... */
    111 #define __byte_swap_word(x) \
    112 ({ register u_short X = (x); \
    113    asm ("rorw $8, %w1" \
    114 	: "=r" (X) \
    115 	: "0" (X)); \
    116    X; })
    117 
    118 #endif	/* __GNUC__ >= 2 */
    119 
    120 #define	ntohl(x)	__byte_swap_long(x)
    121 #define	ntohs(x)	__byte_swap_word(x)
    122 #define	htonl(x)	__byte_swap_long(x)
    123 #define	htons(x)	__byte_swap_word(x)
    124 
    125 #endif	/* __GNUC__ */
    126 
    127 
    128 /*
    129  * Macros for network/external number representation conversion.
    130  */
    131 #define	NTOHL(x)	(x) = ntohl((u_long)x)
    132 #define	NTOHS(x)	(x) = ntohs((u_short)x)
    133 #define	HTONL(x)	(x) = htonl((u_long)x)
    134 #define	HTONS(x)	(x) = htons((u_short)x)
    135 
    136 #endif /* _POSIX_SOURCE */
    137 
    138 #endif /* _MACHINE_ENDIAN_H_ */
    139