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
91 static __inline __uint16_t
__bswap16_var(__uint16_t _x)92 __bswap16_var(__uint16_t _x)
93 {
94
95 return (__bswap16_gen(_x));
96 }
97
98 static __inline __uint32_t
__bswap32_var(__uint32_t _x)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
110 static __inline __uint64_t
__bswap64_var(__uint64_t _x)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