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/*
40 * Define the order of 32-bit words in 64-bit words.
41 */
42#define	_QUAD_HIGHWORD 1
43#define	_QUAD_LOWWORD 0
44
45/*
46 * Definitions for byte order, according to byte significance from low
47 * address to high.
48 */
49#define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
50#define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
51#define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
52
53#define	_BYTE_ORDER	_LITTLE_ENDIAN
54
55/*
56 * Deprecated variants that don't have enough underscores to be useful in more
57 * strict namespaces.
58 */
59#if __BSD_VISIBLE
60#define	LITTLE_ENDIAN	_LITTLE_ENDIAN
61#define	BIG_ENDIAN	_BIG_ENDIAN
62#define	PDP_ENDIAN	_PDP_ENDIAN
63#define	BYTE_ORDER	_BYTE_ORDER
64#endif
65
66#define	__bswap16_gen(x)	(__uint16_t)((x) << 8 | (x) >> 8)
67#define	__bswap32_gen(x)		\
68	(((__uint32_t)__bswap16((x) & 0xffff) << 16) | __bswap16((x) >> 16))
69#define	__bswap64_gen(x)		\
70	(((__uint64_t)__bswap32((x) & 0xffffffff) << 32) | __bswap32((x) >> 32))
71
72#ifdef __GNUCLIKE_BUILTIN_CONSTANT_P
73#define	__bswap16(x)				\
74	((__uint16_t)(__builtin_constant_p(x) ?	\
75	    __bswap16_gen((__uint16_t)(x)) : __bswap16_var(x)))
76#define	__bswap32(x)			\
77	(__builtin_constant_p(x) ?	\
78	    __bswap32_gen((__uint32_t)(x)) : __bswap32_var(x))
79#define	__bswap64(x)			\
80	(__builtin_constant_p(x) ?	\
81	    __bswap64_gen((__uint64_t)(x)) : __bswap64_var(x))
82#else
83/* XXX these are broken for use in static initializers. */
84#define	__bswap16(x)	__bswap16_var(x)
85#define	__bswap32(x)	__bswap32_var(x)
86#define	__bswap64(x)	__bswap64_var(x)
87#endif
88
89/* These are defined as functions to avoid multiple evaluation of x. */
90
91static __inline __uint16_t
92__bswap16_var(__uint16_t _x)
93{
94
95	return (__bswap16_gen(_x));
96}
97
98static __inline __uint32_t
99__bswap32_var(__uint32_t _x)
100{
101
102#ifdef __GNUCLIKE_ASM
103	__asm("bswap %0" : "+r" (_x));
104	return (_x);
105#else
106	return (__bswap32_gen(_x));
107#endif
108}
109
110static __inline __uint64_t
111__bswap64_var(__uint64_t _x)
112{
113
114#if defined(__amd64__) && defined(__GNUCLIKE_ASM)
115	__asm("bswap %0" : "+r" (_x));
116	return (_x);
117#else
118	/*
119	 * It is important for the optimizations that the following is not
120	 * really generic, but expands to 2 __bswap32_var()'s.
121	 */
122	return (__bswap64_gen(_x));
123#endif
124}
125
126#define	__htonl(x)	__bswap32(x)
127#define	__htons(x)	__bswap16(x)
128#define	__ntohl(x)	__bswap32(x)
129#define	__ntohs(x)	__bswap16(x)
130
131#endif /* !_MACHINE_ENDIAN_H_ */
132