endian.h revision 190853
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: head/sys/amd64/include/endian.h 190853 2009-04-08 19:06:47Z ed $
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 __word_swap_int_var(x) \
73__extension__ ({ register __uint32_t __X = (x); \
74   __asm ("rorl $16, %0" : "+r" (__X)); \
75   __X; })
76
77#ifdef __OPTIMIZE__
78
79#define	__word_swap_int_const(x) \
80	((((x) & 0xffff0000) >> 16) | \
81	 (((x) & 0x0000ffff) << 16))
82#define	__word_swap_int(x) (__builtin_constant_p(x) ? \
83	__word_swap_int_const(x) : __word_swap_int_var(x))
84
85#else	/* __OPTIMIZE__ */
86
87#define	__word_swap_int(x) __word_swap_int_var(x)
88
89#endif	/* __OPTIMIZE__ */
90
91#define __byte_swap_int_var(x) \
92__extension__ ({ register __uint32_t __X = (x); \
93   __asm ("bswap %0" : "+r" (__X)); \
94   __X; })
95
96#ifdef __OPTIMIZE__
97
98#define	__byte_swap_int_const(x) \
99	((((x) & 0xff000000) >> 24) | \
100	 (((x) & 0x00ff0000) >>  8) | \
101	 (((x) & 0x0000ff00) <<  8) | \
102	 (((x) & 0x000000ff) << 24))
103#define	__byte_swap_int(x) (__builtin_constant_p(x) ? \
104	__byte_swap_int_const(x) : __byte_swap_int_var(x))
105
106#else	/* __OPTIMIZE__ */
107
108#define	__byte_swap_int(x) __byte_swap_int_var(x)
109
110#endif	/* __OPTIMIZE__ */
111
112#define __byte_swap_long_var(x) \
113__extension__ ({ register __uint64_t __X = (x); \
114   __asm ("bswap %0" : "+r" (__X)); \
115   __X; })
116
117#ifdef __OPTIMIZE__
118
119#define	__byte_swap_long_const(x) \
120	(((x >> 56) | \
121	 ((x >> 40) & 0xff00) | \
122	 ((x >> 24) & 0xff0000) | \
123	 ((x >> 8) & 0xff000000) | \
124	 ((x << 8) & (0xfful << 32)) | \
125	 ((x << 24) & (0xfful << 40)) | \
126	 ((x << 40) & (0xfful << 48)) | \
127	 ((x << 56))))
128
129#define	__byte_swap_long(x) (__builtin_constant_p(x) ? \
130	__byte_swap_long_const(x) : __byte_swap_long_var(x))
131
132#else	/* __OPTIMIZE__ */
133
134#define	__byte_swap_long(x) __byte_swap_long_var(x)
135
136#endif	/* __OPTIMIZE__ */
137
138static __inline __uint64_t
139__bswap64(__uint64_t _x)
140{
141
142	return (__byte_swap_long(_x));
143}
144
145static __inline __uint32_t
146__bswap32(__uint32_t _x)
147{
148
149	return (__byte_swap_int(_x));
150}
151
152static __inline __uint16_t
153__bswap16(__uint16_t _x)
154{
155	return (_x << 8 | _x >> 8);
156}
157
158#define	__htonl(x)	__bswap32(x)
159#define	__htons(x)	__bswap16(x)
160#define	__ntohl(x)	__bswap32(x)
161#define	__ntohs(x)	__bswap16(x)
162
163#else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
164
165/*
166 * No optimizations are available for this compiler.  Fall back to
167 * non-optimized functions by defining the constant usually used to prevent
168 * redefinition.
169 */
170#define	_BYTEORDER_FUNC_DEFINED
171
172#endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
173
174#ifdef __cplusplus
175}
176#endif
177
178#endif /* !_MACHINE_ENDIAN_H_ */
179