xref: /freebsd/sys/powerpc/include/endian.h (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*-
2  * Copyright (c) 1987, 1991, 1993
3  *	The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)endian.h	8.1 (Berkeley) 6/10/93
30  * $FreeBSD$
31  */
32 
33 #ifndef _MACHINE_ENDIAN_H_
34 #define	_MACHINE_ENDIAN_H_
35 
36 #include <sys/cdefs.h>
37 #include <sys/_types.h>
38 
39 /*
40  * Define the order of 32-bit words in 64-bit words.
41  */
42 #define	_QUAD_HIGHWORD 0
43 #define	_QUAD_LOWWORD 1
44 
45 /*
46  * GCC defines _BIG_ENDIAN and _LITTLE_ENDIAN equal to __BIG_ENDIAN__
47  * and __LITTLE_ENDIAN__ (resp).
48  */
49 #ifdef _BIG_ENDIAN
50 #undef _BIG_ENDIAN
51 #endif
52 #ifdef _LITTLE_ENDIAN
53 #undef _LITTLE_ENDIAN
54 #endif
55 
56 /*
57  * Definitions for byte order, according to byte significance from low
58  * address to high.
59  */
60 #define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
61 #define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
62 #define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
63 
64 #ifdef __LITTLE_ENDIAN__
65 #define	_BYTE_ORDER	_LITTLE_ENDIAN
66 #else
67 #define	_BYTE_ORDER	_BIG_ENDIAN
68 #endif
69 
70 /*
71  * Deprecated variants that don't have enough underscores to be useful in more
72  * strict namespaces.
73  */
74 #if __BSD_VISIBLE
75 #define	LITTLE_ENDIAN	_LITTLE_ENDIAN
76 #define	BIG_ENDIAN	_BIG_ENDIAN
77 #define	PDP_ENDIAN	_PDP_ENDIAN
78 #define	BYTE_ORDER	_BYTE_ORDER
79 #endif
80 
81 #if defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
82 #define	__is_constant(x)	__builtin_constant_p(x)
83 #else
84 #define	__is_constant(x)	0
85 #endif
86 
87 #define	__bswap16_const(x)	((((__uint16_t)(x) >> 8) & 0xff) |	\
88 	(((__uint16_t)(x) << 8) & 0xff00))
89 #define	__bswap32_const(x)	((((__uint32_t)(x) >> 24) & 0xff) |	\
90 	(((__uint32_t)(x) >> 8) & 0xff00) |				\
91 	(((__uint32_t)(x)<< 8) & 0xff0000) |				\
92 	(((__uint32_t)(x) << 24) & 0xff000000))
93 #define	__bswap64_const(x)	((((__uint64_t)(x) >> 56) & 0xff) |	\
94 	(((__uint64_t)(x) >> 40) & 0xff00) |				\
95 	(((__uint64_t)(x) >> 24) & 0xff0000) |				\
96 	(((__uint64_t)(x) >> 8) & 0xff000000) |				\
97 	(((__uint64_t)(x) << 8) & ((__uint64_t)0xff << 32)) |		\
98 	(((__uint64_t)(x) << 24) & ((__uint64_t)0xff << 40)) |		\
99 	(((__uint64_t)(x) << 40) & ((__uint64_t)0xff << 48)) |		\
100 	(((__uint64_t)(x) << 56) & ((__uint64_t)0xff << 56)))
101 
102 static __inline __uint16_t
103 __bswap16_var(__uint16_t _x)
104 {
105 
106 	return ((_x >> 8) | ((_x << 8) & 0xff00));
107 }
108 
109 static __inline __uint32_t
110 __bswap32_var(__uint32_t _x)
111 {
112 
113 	return ((_x >> 24) | ((_x >> 8) & 0xff00) | ((_x << 8) & 0xff0000) |
114 	    ((_x << 24) & 0xff000000));
115 }
116 
117 static __inline __uint64_t
118 __bswap64_var(__uint64_t _x)
119 {
120 
121 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
122 	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
123 	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
124 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
125 }
126 
127 #define	__bswap16(x)	(__is_constant(x) ? __bswap16_const(x) : \
128 	__bswap16_var(x))
129 #define	__bswap32(x)	(__is_constant(x) ? __bswap32_const(x) : \
130 	__bswap32_var(x))
131 #define	__bswap64(x)	(__is_constant(x) ? __bswap64_const(x) : \
132 	__bswap64_var(x))
133 
134 #define	__htonl(x)	((__uint32_t)(x))
135 #define	__htons(x)	((__uint16_t)(x))
136 #define	__ntohl(x)	((__uint32_t)(x))
137 #define	__ntohs(x)	((__uint16_t)(x))
138 
139 #endif /* !_MACHINE_ENDIAN_H_ */
140