xref: /freebsd/sys/i386/include/endian.h (revision 8fa113e5fc65fe6abc757f0089f477a87ee4d185)
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  * $FreeBSD$
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 #ifndef _POSIX_SOURCE
47 
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 #include <machine/ansi.h>
62 
63 __BEGIN_DECLS
64 __uint32_t	htonl(__uint32_t);
65 __uint16_t	htons(__uint16_t);
66 __uint32_t	ntohl(__uint32_t);
67 __uint16_t	ntohs(__uint16_t);
68 __END_DECLS
69 
70 #ifdef __GNUC__
71 
72 static __inline __uint32_t
73 __uint16_swap_uint32(__uint32_t __x)
74 {
75 	__asm ("rorl $16, %1" : "=r" (__x) : "0" (__x));
76 
77 	return __x;
78 }
79 
80 static __inline __uint32_t
81 __uint8_swap_uint32(__uint32_t __x)
82 {
83 #if defined(_KERNEL) && (defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)) && !defined(I386_CPU)
84 	__asm ("bswap %0" : "=r" (__x) : "0" (__x));
85 #else
86 	__asm ("xchgb %h1, %b1\n\t"
87 	       "rorl $16, %1\n\t"
88 	       "xchgb %h1, %b1"
89 	       : "=q" (__x) : "0" (__x));
90 #endif
91 	return __x;
92 }
93 
94 static __inline __uint16_t
95 __uint8_swap_uint16(__uint16_t __x)
96 {
97 	__asm ("xchgb %h1, %b1" : "=q" (__x) : "0" (__x));
98 
99 	return __x;
100 }
101 
102 /*
103  * Macros for network/external number representation conversion.
104  */
105 #define	ntohl	__uint8_swap_uint32
106 #define	ntohs	__uint8_swap_uint16
107 #define	htonl	__uint8_swap_uint32
108 #define	htons	__uint8_swap_uint16
109 
110 #endif	/* __GNUC__ */
111 
112 #define	NTOHL(x)	((x) = ntohl(x))
113 #define	NTOHS(x)	((x) = ntohs(x))
114 #define	HTONL(x)	((x) = htonl(x))
115 #define	HTONS(x)	((x) = htons(x))
116 
117 
118 #endif /* ! _POSIX_SOURCE */
119 
120 #endif /* !_MACHINE_ENDIAN_H_ */
121