xref: /freebsd/sys/powerpc/include/endian.h (revision 64a0982bee3db2236df43357e70ce8dddbc21d48)
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  * 3. 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 #ifdef __LITTLE_ENDIAN__
43 #define	_QUAD_HIGHWORD 1
44 #define	_QUAD_LOWWORD 0
45 #else
46 #define	_QUAD_HIGHWORD 0
47 #define	_QUAD_LOWWORD 1
48 #endif
49 
50 /*
51  * GCC defines _BIG_ENDIAN and _LITTLE_ENDIAN equal to __BIG_ENDIAN__
52  * and __LITTLE_ENDIAN__ (resp).
53  */
54 #ifdef _BIG_ENDIAN
55 #undef _BIG_ENDIAN
56 #endif
57 #ifdef _LITTLE_ENDIAN
58 #undef _LITTLE_ENDIAN
59 #endif
60 
61 /*
62  * Definitions for byte order, according to byte significance from low
63  * address to high.
64  */
65 #define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
66 #define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
67 #define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
68 
69 #ifdef __LITTLE_ENDIAN__
70 #define	_BYTE_ORDER	_LITTLE_ENDIAN
71 #else
72 #define	_BYTE_ORDER	_BIG_ENDIAN
73 #endif
74 
75 /*
76  * Deprecated variants that don't have enough underscores to be useful in more
77  * strict namespaces.
78  */
79 #if __BSD_VISIBLE
80 #define	LITTLE_ENDIAN	_LITTLE_ENDIAN
81 #define	BIG_ENDIAN	_BIG_ENDIAN
82 #define	PDP_ENDIAN	_PDP_ENDIAN
83 #define	BYTE_ORDER	_BYTE_ORDER
84 #endif
85 
86 #if defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
87 #define	__is_constant(x)	__builtin_constant_p(x)
88 #else
89 #define	__is_constant(x)	0
90 #endif
91 
92 #define	__bswap16_const(x)	((((__uint16_t)(x) >> 8) & 0xff) |	\
93 	(((__uint16_t)(x) << 8) & 0xff00))
94 #define	__bswap32_const(x)	((((__uint32_t)(x) >> 24) & 0xff) |	\
95 	(((__uint32_t)(x) >> 8) & 0xff00) |				\
96 	(((__uint32_t)(x)<< 8) & 0xff0000) |				\
97 	(((__uint32_t)(x) << 24) & 0xff000000))
98 #define	__bswap64_const(x)	((((__uint64_t)(x) >> 56) & 0xff) |	\
99 	(((__uint64_t)(x) >> 40) & 0xff00) |				\
100 	(((__uint64_t)(x) >> 24) & 0xff0000) |				\
101 	(((__uint64_t)(x) >> 8) & 0xff000000) |				\
102 	(((__uint64_t)(x) << 8) & ((__uint64_t)0xff << 32)) |		\
103 	(((__uint64_t)(x) << 24) & ((__uint64_t)0xff << 40)) |		\
104 	(((__uint64_t)(x) << 40) & ((__uint64_t)0xff << 48)) |		\
105 	(((__uint64_t)(x) << 56) & ((__uint64_t)0xff << 56)))
106 
107 static __inline __uint16_t
108 __bswap16_var(__uint16_t _x)
109 {
110 
111 	return ((_x >> 8) | ((_x << 8) & 0xff00));
112 }
113 
114 static __inline __uint32_t
115 __bswap32_var(__uint32_t _x)
116 {
117 
118 	return ((_x >> 24) | ((_x >> 8) & 0xff00) | ((_x << 8) & 0xff0000) |
119 	    ((_x << 24) & 0xff000000));
120 }
121 
122 static __inline __uint64_t
123 __bswap64_var(__uint64_t _x)
124 {
125 
126 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
127 	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
128 	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
129 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
130 }
131 
132 #define	__bswap16(x)	((__uint16_t)(__is_constant(x) ? __bswap16_const(x) : \
133 	__bswap16_var(x)))
134 #define	__bswap32(x)	(__is_constant(x) ? __bswap32_const(x) : \
135 	__bswap32_var(x))
136 #define	__bswap64(x)	(__is_constant(x) ? __bswap64_const(x) : \
137 	__bswap64_var(x))
138 
139 #ifdef __LITTLE_ENDIAN__
140 #define	__htonl(x)	(__bswap32((__uint32_t)(x)))
141 #define	__htons(x)	(__bswap16((__uint16_t)(x)))
142 #define	__ntohl(x)	(__bswap32((__uint32_t)(x)))
143 #define	__ntohs(x)	(__bswap16((__uint16_t)(x)))
144 #else
145 #define	__htonl(x)	((__uint32_t)(x))
146 #define	__htons(x)	((__uint16_t)(x))
147 #define	__ntohl(x)	((__uint32_t)(x))
148 #define	__ntohs(x)	((__uint16_t)(x))
149 #endif
150 
151 #endif /* !_MACHINE_ENDIAN_H_ */
152