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endian.h revision 1.6 
      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 1.6 1993/09/16 05:59:43 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 #ifndef KERNEL
     59 #include <sys/cdefs.h>
     60 #endif
     61 
     62 __BEGIN_DECLS
     63 unsigned long   htonl __P((unsigned long));
     64 unsigned short  htons __P((unsigned short));
     65 unsigned long   ntohl __P((unsigned long));
     66 unsigned short  ntohs __P((unsigned short));
     67 __END_DECLS
     68 
     69 
     70 #if __GNUC__
     71 
     72 #if __GNUC__ >= 2
     73 
     74 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     75 #define __byte_swap_long(x) \
     76 ({ register unsigned long X = (x); \
     77    asm ("bswap %1" \
     78 	: "=q" (X) \
     79 	: "0" (X)); \
     80    X; })
     81 #else
     82 #define __byte_swap_long(x) \
     83 ({ register unsigned long X = (x); \
     84    asm ("xchgb %h1, %b1\n\trorl $16, %1\n\txchgb %h1, %b1" \
     85 	: "=q" (X) \
     86 	: "0" (X)); \
     87    X; })
     88 #endif	/* KERNEL && ... */
     89 #define __byte_swap_word(x) \
     90 ({ register unsigned short X = (x); \
     91    asm ("xchgb %h1, %b1" \
     92 	: "=q" (X) \
     93 	: "0" (X)); \
     94    X; })
     95 
     96 #else	/* __GNUC__ >= 2 */
     97 
     98 #if defined(KERNEL) && ((defined(I486_CPU) || defined(I586_CPU)) && !defined(I386_CPU))
     99 #define __byte_swap_long(x) \
    100 ({ register unsigned long X = (x); \
    101    asm ("bswap %1" \
    102 	: "=r" (X) \
    103 	: "0" (X)); \
    104    X; })
    105 #else
    106 #define __byte_swap_long(x) \
    107 ({ register u_long X = (x); \
    108    asm ("rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" \
    109 	: "=r" (X) \
    110 	: "0" (X)); \
    111    X; })
    112 #endif	/* KERNEL && ... */
    113 #define __byte_swap_word(x) \
    114 ({ register u_short X = (x); \
    115    asm ("rorw $8, %w1" \
    116 	: "=r" (X) \
    117 	: "0" (X)); \
    118    X; })
    119 
    120 #endif	/* __GNUC__ >= 2 */
    121 
    122 #define	ntohl(x)	__byte_swap_long(x)
    123 #define	ntohs(x)	__byte_swap_word(x)
    124 #define	htonl(x)	__byte_swap_long(x)
    125 #define	htons(x)	__byte_swap_word(x)
    126 
    127 #endif	/* __GNUC__ */
    128 
    129 
    130 /*
    131  * Macros for network/external number representation conversion.
    132  */
    133 #define	NTOHL(x)	(x) = ntohl((u_long)x)
    134 #define	NTOHS(x)	(x) = ntohs((u_short)x)
    135 #define	HTONL(x)	(x) = htonl((u_long)x)
    136 #define	HTONS(x)	(x) = htons((u_short)x)
    137 
    138 #endif /* _POSIX_SOURCE */
    139 
    140 #endif /* _MACHINE_ENDIAN_H_ */
    141