2 * Copyright (c) 1987, 1991 Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 * @(#)endian.h 7.8 (Berkeley) 4/3/91
33 #ifndef _MACHINE_ENDIAN_H_
34 #define _MACHINE_ENDIAN_H_
36 #include <sys/cdefs.h>
37 #include <sys/_types.h>
44 * Define the order of 32-bit words in 64-bit words.
46 #define _QUAD_HIGHWORD 1
47 #define _QUAD_LOWWORD 0
50 * Definitions for byte order, according to byte significance from low
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 */
57 #define _BYTE_ORDER _LITTLE_ENDIAN
60 * Deprecated variants that don't have enough underscores to be useful in more
64 #define LITTLE_ENDIAN _LITTLE_ENDIAN
65 #define BIG_ENDIAN _BIG_ENDIAN
66 #define PDP_ENDIAN _PDP_ENDIAN
67 #define BYTE_ORDER _BYTE_ORDER
70 #if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
72 #define __bswap64_const(_x) \
74 (((_x) >> 40) & (0xffULL << 8)) | \
75 (((_x) >> 24) & (0xffULL << 16)) | \
76 (((_x) >> 8) & (0xffULL << 24)) | \
77 (((_x) << 8) & (0xffULL << 32)) | \
78 (((_x) << 24) & (0xffULL << 40)) | \
79 (((_x) << 40) & (0xffULL << 48)) | \
82 #define __bswap32_const(_x) \
84 (((_x) & (0xff << 16)) >> 8) | \
85 (((_x) & (0xff << 8)) << 8) | \
88 #define __bswap16_const(_x) (__uint16_t)((_x) << 8 | (_x) >> 8)
90 static __inline __uint64_t
91 __bswap64_var(__uint64_t __x)
94 return __bswap64_const(__x);
98 static __inline __uint32_t
99 __bswap32_var(__uint32_t _x)
102 __asm ("bswap %0" : "+r" (_x));
106 static __inline __uint16_t
107 __bswap16_var(__uint16_t _x)
110 return (__bswap16_const(_x));
113 #define __bswap64(_x) \
114 (__builtin_constant_p(_x) ? \
115 __bswap64_const((__uint64_t)(_x)) : __bswap64_var(_x))
117 #define __bswap32(_x) \
118 (__builtin_constant_p(_x) ? \
119 __bswap32_const((__uint32_t)(_x)) : __bswap32_var(_x))
121 #define __bswap16(_x) \
122 ((__uint16_t)(__builtin_constant_p(_x) ? \
123 __bswap16_const((__uint16_t)(_x)) : __bswap16_var(_x)))
125 #define __htonl(x) __bswap32(x)
126 #define __htons(x) __bswap16(x)
127 #define __ntohl(x) __bswap32(x)
128 #define __ntohs(x) __bswap16(x)
130 #else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
133 * No optimizations are available for this compiler. Fall back to
134 * non-optimized functions by defining the constant usually used to prevent
137 #define _BYTEORDER_FUNC_DEFINED
139 #endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
145 #endif /* !_MACHINE_ENDIAN_H_ */