xref: /netbsd-src/sys/arch/i386/include/endian.h (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*	$NetBSD: endian.h,v 1.14 1994/10/27 04:16:03 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1991 Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)endian.h	7.8 (Berkeley) 4/3/91
36  */
37 
38 #ifndef _I386_ENDIAN_H_
39 #define	_I386_ENDIAN_H_
40 
41 /*
42  * Define the order of 32-bit words in 64-bit words.
43  */
44 #define _QUAD_HIGHWORD 1
45 #define _QUAD_LOWWORD 0
46 
47 
48 #ifndef _POSIX_SOURCE
49 /*
50  * Definitions for byte order, according to byte significance from low
51  * address to high.
52  */
53 #define	LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
54 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
55 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
56 
57 #define	BYTE_ORDER	LITTLE_ENDIAN
58 
59 #include <sys/cdefs.h>
60 
61 __BEGIN_DECLS
62 unsigned long   htonl __P((unsigned long));
63 unsigned short  htons __P((unsigned short));
64 unsigned long   ntohl __P((unsigned long));
65 unsigned short  ntohs __P((unsigned short));
66 __END_DECLS
67 
68 
69 #ifdef __GNUC__
70 
71 #if defined(KERNEL) && !defined(I386_CPU)
72 #define __byte_swap_long(x) \
73 ({ register unsigned long __x = (x); \
74    __asm ("bswap %1" \
75 	: "=r" (__x) \
76 	: "0" (__x)); \
77    __x; })
78 #else
79 #define __byte_swap_long(x) \
80 ({ register unsigned long __x = (x); \
81    __asm ("rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" \
82 	: "=r" (__x) \
83 	: "0" (__x)); \
84    __x; })
85 #endif	/* KERNEL && ... */
86 
87 #define __byte_swap_word(x) \
88 ({ register unsigned short __x = (x); \
89    __asm ("rorw $8, %w1" \
90 	: "=r" (__x) \
91 	: "0" (__x)); \
92    __x; })
93 
94 #define	ntohl(x)	__byte_swap_long(x)
95 #define	ntohs(x)	__byte_swap_word(x)
96 #define	htonl(x)	__byte_swap_long(x)
97 #define	htons(x)	__byte_swap_word(x)
98 
99 #endif	/* __GNUC__ */
100 
101 
102 /*
103  * Macros for network/external number representation conversion.
104  */
105 #define	NTOHL(x)	(x) = ntohl((unsigned long)(x))
106 #define	NTOHS(x)	(x) = ntohs((unsigned short)(x))
107 #define	HTONL(x)	(x) = htonl((unsigned long)(x))
108 #define	HTONS(x)	(x) = htons((unsigned short)(x))
109 
110 #endif /* _POSIX_SOURCE */
111 
112 #endif /* !_I386_ENDIAN_H_ */
113