xref: /freebsd/sys/powerpc/include/endian.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)endian.h	8.1 (Berkeley) 6/10/93
32  * $FreeBSD$
33  */
34 
35 #ifndef _MACHINE_ENDIAN_H_
36 #define	_MACHINE_ENDIAN_H_
37 
38 #include <sys/cdefs.h>
39 #include <sys/_types.h>
40 
41 /*
42  * Define the order of 32-bit words in 64-bit words.
43  */
44 #ifdef __LITTLE_ENDIAN__
45 #define	_QUAD_HIGHWORD 1
46 #define	_QUAD_LOWWORD 0
47 #else
48 #define	_QUAD_HIGHWORD 0
49 #define	_QUAD_LOWWORD 1
50 #endif
51 
52 /*
53  * GCC defines _BIG_ENDIAN and _LITTLE_ENDIAN equal to __BIG_ENDIAN__
54  * and __LITTLE_ENDIAN__ (resp).
55  */
56 #ifdef _BIG_ENDIAN
57 #undef _BIG_ENDIAN
58 #endif
59 #ifdef _LITTLE_ENDIAN
60 #undef _LITTLE_ENDIAN
61 #endif
62 
63 /*
64  * Definitions for byte order, according to byte significance from low
65  * address to high.
66  */
67 #define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
68 #define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
69 #define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
70 
71 #ifdef __LITTLE_ENDIAN__
72 #define	_BYTE_ORDER	_LITTLE_ENDIAN
73 #else
74 #define	_BYTE_ORDER	_BIG_ENDIAN
75 #endif
76 
77 /*
78  * Deprecated variants that don't have enough underscores to be useful in more
79  * strict namespaces.
80  */
81 #if __BSD_VISIBLE
82 #define	LITTLE_ENDIAN	_LITTLE_ENDIAN
83 #define	BIG_ENDIAN	_BIG_ENDIAN
84 #define	PDP_ENDIAN	_PDP_ENDIAN
85 #define	BYTE_ORDER	_BYTE_ORDER
86 #endif
87 
88 #if defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
89 #define	__is_constant(x)	__builtin_constant_p(x)
90 #else
91 #define	__is_constant(x)	0
92 #endif
93 
94 #define	__bswap16_const(x)	((((__uint16_t)(x) >> 8) & 0xff) |	\
95 	(((__uint16_t)(x) << 8) & 0xff00))
96 #define	__bswap32_const(x)	((((__uint32_t)(x) >> 24) & 0xff) |	\
97 	(((__uint32_t)(x) >> 8) & 0xff00) |				\
98 	(((__uint32_t)(x)<< 8) & 0xff0000) |				\
99 	(((__uint32_t)(x) << 24) & 0xff000000))
100 #define	__bswap64_const(x)	((((__uint64_t)(x) >> 56) & 0xff) |	\
101 	(((__uint64_t)(x) >> 40) & 0xff00) |				\
102 	(((__uint64_t)(x) >> 24) & 0xff0000) |				\
103 	(((__uint64_t)(x) >> 8) & 0xff000000) |				\
104 	(((__uint64_t)(x) << 8) & ((__uint64_t)0xff << 32)) |		\
105 	(((__uint64_t)(x) << 24) & ((__uint64_t)0xff << 40)) |		\
106 	(((__uint64_t)(x) << 40) & ((__uint64_t)0xff << 48)) |		\
107 	(((__uint64_t)(x) << 56) & ((__uint64_t)0xff << 56)))
108 
109 static __inline __uint16_t
110 __bswap16_var(__uint16_t _x)
111 {
112 
113 	return ((_x >> 8) | ((_x << 8) & 0xff00));
114 }
115 
116 static __inline __uint32_t
117 __bswap32_var(__uint32_t _x)
118 {
119 
120 	return ((_x >> 24) | ((_x >> 8) & 0xff00) | ((_x << 8) & 0xff0000) |
121 	    ((_x << 24) & 0xff000000));
122 }
123 
124 static __inline __uint64_t
125 __bswap64_var(__uint64_t _x)
126 {
127 
128 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
129 	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
130 	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
131 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
132 }
133 
134 #define	__bswap16(x)	((__uint16_t)(__is_constant(x) ? __bswap16_const(x) : \
135 	__bswap16_var(x)))
136 #define	__bswap32(x)	(__is_constant(x) ? __bswap32_const(x) : \
137 	__bswap32_var(x))
138 #define	__bswap64(x)	(__is_constant(x) ? __bswap64_const(x) : \
139 	__bswap64_var(x))
140 
141 #ifdef __LITTLE_ENDIAN__
142 #define	__htonl(x)	(__bswap32((__uint32_t)(x)))
143 #define	__htons(x)	(__bswap16((__uint16_t)(x)))
144 #define	__ntohl(x)	(__bswap32((__uint32_t)(x)))
145 #define	__ntohs(x)	(__bswap16((__uint16_t)(x)))
146 #else
147 #define	__htonl(x)	((__uint32_t)(x))
148 #define	__htons(x)	((__uint16_t)(x))
149 #define	__ntohl(x)	((__uint32_t)(x))
150 #define	__ntohs(x)	((__uint16_t)(x))
151 #endif
152 
153 #endif /* !_MACHINE_ENDIAN_H_ */
154