endian.h revision 114349 
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)endian.h	7.8 (Berkeley) 4/3/91
34 * $FreeBSD: head/sys/amd64/include/endian.h 114349 2003-05-01 01:05:25Z peter $
35 */
36
37#ifndef _MACHINE_ENDIAN_H_
38#define	_MACHINE_ENDIAN_H_
39
40#include <sys/cdefs.h>
41#include <sys/_types.h>
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#ifdef __GNUC__
71
72#define __word_swap_int(x) \
73__extension__ ({ register __uint32_t __X = (x); \
74   __asm ("rorl $16, %0" : "+r" (__X)); \
75   __X; })
76
77#define __byte_swap_int(x) \
78__extension__ ({ register __uint32_t __X = (x); \
79   __asm ("bswap %0" : "+r" (__X)); \
80   __X; })
81
82#define __byte_swap_long(x) \
83__extension__ ({ register __uint64_t __X = (x); \
84   __asm ("bswap %0" : "+r" (__X)); \
85   __X; })
86
87#define __byte_swap_word(x) \
88__extension__ ({ register __uint16_t __X = (x); \
89   __asm ("xchgb %h0, %b0" : "+Q" (__X)); \
90   __X; })
91
92static __inline __uint64_t
93__bswap64(__uint64_t _x)
94{
95
96	return (__byte_swap_long(_x));
97}
98
99static __inline __uint32_t
100__bswap32(__uint32_t _x)
101{
102
103	return (__byte_swap_int(_x));
104}
105
106static __inline __uint16_t
107__bswap16(__uint16_t _x)
108{
109
110	return (__byte_swap_word(_x));
111}
112
113#define	__htonl(x)	__bswap32(x)
114#define	__htons(x)	__bswap16(x)
115#define	__ntohl(x)	__bswap32(x)
116#define	__ntohs(x)	__bswap16(x)
117
118#else /* !__GNUC__ */
119
120/*
121 * No optimizations are available for this compiler.  Fall back to
122 * non-optimized functions by defining the constant usually used to prevent
123 * redefinition.
124 */
125#define	_BYTEORDER_FUNC_DEFINED
126
127#endif /* __GNUC__ */
128
129#endif /* !_MACHINE_ENDIAN_H_ */
130