xref: /netbsd-src/sys/arch/i386/include/endian.h (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
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 1.10 1994/03/16 17:20:24 jtc 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(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 ("rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" \
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 ("rorw $8, %w1" \
90 	: "=q" (__x) \
91 	: "0" (__x)); \
92    __x; })
93 
94 #else	/* __GNUC__ >= 2 */
95 
96 #if defined(KERNEL) && !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