xref: /freebsd/sys/i386/include/endian.h (revision c17d43407fe04133a94055b0dbc7ea8965654a9f)
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  *	@(#)endian.h	7.8 (Berkeley) 4/3/91
34  * $FreeBSD$
35  */
36 
37 #ifndef _MACHINE_ENDIAN_H_
38 #define	_MACHINE_ENDIAN_H_
39 
40 #include <sys/cdefs.h>
41 #include <machine/ansi.h>
42 
43 /*
44  * Define the order of 32-bit words in 64-bit words.
45  */
46 #define	_QUAD_HIGHWORD 1
47 #define	_QUAD_LOWWORD 0
48 
49 #ifndef _POSIX_SOURCE
50 /*
51  * Definitions for byte order, according to byte significance from low
52  * address to high.
53  */
54 #define	LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
55 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
56 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
57 
58 #define	BYTE_ORDER	LITTLE_ENDIAN
59 #endif /* ! _POSIX_SOURCE */
60 
61 #ifdef __GNUC__
62 
63 #define __word_swap_int(x) \
64 __extension__ ({ register __uint32_t __X = (x); \
65    __asm ("rorl $16, %0" : "+r" (__X)); \
66    __X; })
67 
68 #if defined(_KERNEL) && (defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)) && !defined(I386_CPU)
69 
70 #define __byte_swap_int(x) \
71 __extension__ ({ register __uint32_t __X = (x); \
72    __asm ("bswap %0" : "+r" (__X)); \
73    __X; })
74 #else
75 
76 #define __byte_swap_int(x) \
77 __extension__ ({ register __uint32_t __X = (x); \
78    __asm ("xchgb %h0, %b0\n\trorl $16, %0\n\txchgb %h0, %b0" \
79        : "+q" (__X)); \
80    __X; })
81 #endif
82 
83 #define __byte_swap_word(x) \
84 __extension__ ({ register __uint16_t __X = (x); \
85    __asm ("xchgb %h0, %b0" : "+q" (__X)); \
86    __X; })
87 
88 static __inline __uint64_t
89 __bswap64(__uint64_t _x)
90 {
91 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
92 	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
93 	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
94 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
95 }
96 
97 static __inline __uint32_t
98 __bswap32(__uint32_t _x)
99 {
100 
101 	return (__byte_swap_int(_x));
102 }
103 
104 static __inline __uint16_t
105 __bswap16(__uint16_t _x)
106 {
107 
108 	return (__byte_swap_word(_x));
109 }
110 
111 #endif /* __GNUC__ */
112 
113 #define	__htonl(x)	__bswap32(x)
114 #define	__htons(x)	__bswap16(x)
115 #define	__ntohl(x)	__bswap32(x)
116 #define	__ntohs(x)	__bswap16(x)
117 
118 #endif /* !_MACHINE_ENDIAN_H_ */
119