xref: /freebsd/sys/i386/include/endian.h (revision df7f5d4de4592a8948a25ce01e5bddfbb7ce39dc)
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 1.13 1997/02/22 09:34:31 peter 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  * Definitions for byte order, according to byte significance from low
48  * address to high.
49  */
50 #define	LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
51 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
52 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
53 
54 #define	BYTE_ORDER	LITTLE_ENDIAN
55 
56 #ifndef KERNEL
57 #include <sys/cdefs.h>
58 #else
59 #ifndef ACTUALLY_LKM_NOT_KERNEL
60 #include "opt_cpu.h"
61 #endif
62 #endif
63 
64 #define __word_swap_long(x) \
65 __extension__ ({ register u_long __X = (x); \
66    __asm ("rorl $16, %1" \
67 	: "=r" (__X) \
68 	: "0" (__X)); \
69    __X; })
70 
71 #if defined(KERNEL) && (defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)) && !defined(I386_CPU)
72 
73 #define __byte_swap_long(x) \
74 __extension__ ({ register u_long __X = (x); \
75    __asm ("bswap %0" \
76 	: "=r" (__X) \
77 	: "0" (__X)); \
78    __X; })
79 #else
80 
81 #define __byte_swap_long(x) \
82 __extension__ ({ register u_long __X = (x); \
83    __asm ("xchgb %h1, %b1\n\trorl $16, %1\n\txchgb %h1, %b1" \
84 	: "=q" (__X) \
85 	: "0" (__X)); \
86    __X; })
87 #endif
88 
89 #define __byte_swap_word(x) \
90 __extension__ ({ register u_short __X = (x); \
91    __asm ("xchgb %h1, %b1" \
92 	: "=q" (__X) \
93 	: "0" (__X)); \
94    __X; })
95 
96 /*
97  * Macros for network/external number representation conversion.
98  */
99 #if BYTE_ORDER == BIG_ENDIAN || defined(lint)
100 #define	ntohl(x)	(x)
101 #define	ntohs(x)	(x)
102 #define	htonl(x)	(x)
103 #define	htons(x)	(x)
104 
105 #define	NTOHL(x)	(x)
106 #define	NTOHS(x)	(x)
107 #define	HTONL(x)	(x)
108 #define	HTONS(x)	(x)
109 
110 #else
111 
112 #ifdef __GNUC__
113 #define	ntohl	__byte_swap_long
114 #define	ntohs	__byte_swap_word
115 #define	htonl	__byte_swap_long
116 #define	htons	__byte_swap_word
117 #endif
118 
119 #define	NTOHL(x)	((x) = ntohl((u_long)(x)))
120 #define	NTOHS(x)	((x) = ntohs((u_short)(x)))
121 #define	HTONL(x)	((x) = htonl((u_long)(x)))
122 #define	HTONS(x)	((x) = htons((u_short)(x)))
123 #endif
124 
125 #endif /* !_MACHINE_ENDIAN_H_ */
126