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 __bswap16_const(_x) (__uint16_t)((_x) << 8 | (_x) >> 8)
74 #define __bswap16(_x) \
75 (__builtin_constant_p(_x) ? \
76 __bswap16_const((__uint16_t)(_x)) : __bswap16_var(_x))
78 #define __bswap32_const(_x) \
79 (((__uint32_t)__bswap16(_x) << 16) | __bswap16((_x) >> 16))
81 #define __bswap32(_x) \
82 (__builtin_constant_p(_x) ? \
83 __bswap32_const((__uint32_t)(_x)) : __bswap32_var(_x))
85 #define __bswap64_const(_x) \
86 (((__uint64_t)__bswap32(_x) << 32) | __bswap32((_x) >> 32))
88 #define __bswap64(_x) \
89 (__builtin_constant_p(_x) ? \
90 __bswap64_const((__uint64_t)(_x)) : __bswap64_var(_x))
92 static __inline __uint16_t
93 __bswap16_var(__uint16_t _x)
96 return (__bswap16_const(_x));
99 static __inline __uint32_t
100 __bswap32_var(__uint32_t _x)
103 __asm ("bswap %0" : "+r" (_x));
107 static __inline __uint64_t
108 __bswap64_var(__uint64_t _x)
111 __asm ("bswap %0" : "+r" (_x));
114 return (__bswap64_const(_x));
118 #define __htonl(x) __bswap32(x)
119 #define __htons(x) __bswap16(x)
120 #define __ntohl(x) __bswap32(x)
121 #define __ntohs(x) __bswap16(x)
123 #else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
126 * No optimizations are available for this compiler. Fall back to
127 * non-optimized functions by defining the constant usually used to prevent
130 #define _BYTEORDER_FUNC_DEFINED
132 #endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
138 #endif /* !_MACHINE_ENDIAN_H_ */