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 __word_swap_int_var(x) \
73 __extension__ ({ register __uint32_t __X = (x); \
74 __asm ("rorl $16, %0" : "+r" (__X)); \
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))
85 #else /* __OPTIMIZE__ */
87 #define __word_swap_int(x) __word_swap_int_var(x)
89 #endif /* __OPTIMIZE__ */
91 #define __byte_swap_int_var(x) \
92 __extension__ ({ register __uint32_t __X = (x); \
93 __asm ("bswap %0" : "+r" (__X)); \
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))
106 #else /* __OPTIMIZE__ */
108 #define __byte_swap_int(x) __byte_swap_int_var(x)
110 #endif /* __OPTIMIZE__ */
112 #define __byte_swap_word_var(x) \
113 __extension__ ({ register __uint16_t __X = (x); \
114 __asm ("xchgb %h0, %b0" : "+q" (__X)); \
119 #define __byte_swap_word_const(x) \
120 ((((x) & 0xff00) >> 8) | \
121 (((x) & 0x00ff) << 8))
123 #define __byte_swap_word(x) (__builtin_constant_p(x) ? \
124 __byte_swap_word_const(x) : __byte_swap_word_var(x))
126 #else /* __OPTIMIZE__ */
128 #define __byte_swap_word(x) __byte_swap_word_var(x)
130 #endif /* __OPTIMIZE__ */
132 static __inline __uint64_t
133 __bswap64(__uint64_t _x)
136 return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
137 ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
138 ((_x << 24) & ((__uint64_t)0xff << 40)) |
139 ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
142 static __inline __uint32_t
143 __bswap32(__uint32_t _x)
146 return (__byte_swap_int(_x));
149 static __inline __uint16_t
150 __bswap16(__uint16_t _x)
153 return (__byte_swap_word(_x));
156 #define __htonl(x) __bswap32(x)
157 #define __htons(x) __bswap16(x)
158 #define __ntohl(x) __bswap32(x)
159 #define __ntohs(x) __bswap16(x)
161 #else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
164 * No optimizations are available for this compiler. Fall back to
165 * non-optimized functions by defining the constant usually used to prevent
168 #define _BYTEORDER_FUNC_DEFINED
170 #endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
176 #endif /* !_MACHINE_ENDIAN_H_ */