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
102static __inline __uint16_t
103__bswap16_var(__uint16_t _x)
104{
105
106	return ((_x >> 8) | ((_x << 8) & 0xff00));
107}
108
109static __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
117static __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)	((__uint16_t)(__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