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 * 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	7.8 (Berkeley) 4/3/91
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#ifdef __cplusplus
40extern "C" {
41#endif
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/*
50 * Definitions for byte order, according to byte significance from low
51 * address to high.
52 */
53#define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
54#define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
55#define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
56
57#define	_BYTE_ORDER	_LITTLE_ENDIAN
58
59/*
60 * Deprecated variants that don't have enough underscores to be useful in more
61 * strict namespaces.
62 */
63#if __BSD_VISIBLE
64#define	LITTLE_ENDIAN	_LITTLE_ENDIAN
65#define	BIG_ENDIAN	_BIG_ENDIAN
66#define	PDP_ENDIAN	_PDP_ENDIAN
67#define	BYTE_ORDER	_BYTE_ORDER
68#endif
69
70#if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
71
72#define	__bswap64_const(_x)			\
73	(((_x) >> 56) |				\
74	(((_x) >> 40) & (0xffUL << 8)) |	\
75	(((_x) >> 24) & (0xffUL << 16)) |	\
76	(((_x) >> 8) & (0xffUL << 24)) |	\
77	(((_x) << 8) & (0xffUL << 32)) |	\
78	(((_x) << 24) & (0xffUL << 40)) |	\
79	(((_x) << 40) & (0xffUL << 48)) |	\
80	((_x) << 56))
81
82#define	__bswap32_const(_x)			\
83	(((_x) >> 24) |				\
84	(((_x) & (0xff << 16)) >> 8) |		\
85	(((_x) & (0xff << 8)) << 8) |		\
86	((_x) << 24))
87
88#define __bswap16_const(_x)	(__uint16_t)((_x) << 8 | (_x) >> 8)
89
90static __inline __uint64_t
91__bswap64_var(__uint64_t _x)
92{
93
94	__asm ("bswap %0" : "+r" (_x));
95	return (_x);
96}
97
98static __inline __uint32_t
99__bswap32_var(__uint32_t _x)
100{
101
102	__asm ("bswap %0" : "+r" (_x));
103	return (_x);
104}
105
106static __inline __uint16_t
107__bswap16_var(__uint16_t _x)
108{
109
110	return (__bswap16_const(_x));
111}
112
113#define	__bswap64(_x)					\
114	(__builtin_constant_p(_x) ?			\
115	    __bswap64_const((__uint64_t)(_x)) : __bswap64_var(_x))
116
117#define	__bswap32(_x)					\
118	(__builtin_constant_p(_x) ?			\
119	    __bswap32_const((__uint32_t)(_x)) : __bswap32_var(_x))
120
121#define	__bswap16(_x)					\
122	((__uint16_t)(__builtin_constant_p(_x) ?	\
123	    __bswap16_const((__uint16_t)(_x)) : __bswap16_var(_x)))
124
125#define	__htonl(x)	__bswap32(x)
126#define	__htons(x)	__bswap16(x)
127#define	__ntohl(x)	__bswap32(x)
128#define	__ntohs(x)	__bswap16(x)
129
130#else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
131
132/*
133 * No optimizations are available for this compiler.  Fall back to
134 * non-optimized functions by defining the constant usually used to prevent
135 * redefinition.
136 */
137#define	_BYTEORDER_FUNC_DEFINED
138
139#endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
140
141#ifdef __cplusplus
142}
143#endif
144
145#endif /* !_MACHINE_ENDIAN_H_ */
146