2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1987, 1991 Regents of the University of California.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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32 #ifndef _SYS__ENDIAN_H_
33 #define _SYS__ENDIAN_H_
35 #ifndef _MACHINE_ENDIAN_H_
36 #error "sys/_endian.h should not be included directly"
39 /* BSD Compatiblity */
40 #define _BYTE_ORDER __BYTE_ORDER__
43 * Definitions for byte order, according to byte significance from low
46 #define _LITTLE_ENDIAN __ORDER_LITTLE_ENDIAN__ /* LSB first: 1234 */
47 #define _BIG_ENDIAN __ORDER_BIG_ENDIAN__ /* MSB first: 4321 */
48 #define _PDP_ENDIAN __ORDER_PDP_ENDIAN__ /* LSB first in word,
49 * MSW first in long: 3412 */
52 * Define the order of 32-bit words in 64-bit words.
54 #if _BYTE_ORDER == _LITTLE_ENDIAN
55 #define _QUAD_HIGHWORD 1
56 #define _QUAD_LOWWORD 0
57 #elif _BYTE_ORDER == _BIG_ENDIAN
58 #define _QUAD_HIGHWORD 0
59 #define _QUAD_LOWWORD 1
61 #error "Unsupported endian"
65 * Deprecated variants that don't have enough underscores to be useful in more
69 #define LITTLE_ENDIAN _LITTLE_ENDIAN
70 #define BIG_ENDIAN _BIG_ENDIAN
71 #define PDP_ENDIAN _PDP_ENDIAN
72 #define BYTE_ORDER _BYTE_ORDER
75 /* bswap primitives, based on compiler builtins */
76 #define __bswap16(x) __builtin_bswap16(x)
77 #define __bswap32(x) __builtin_bswap32(x)
78 #define __bswap64(x) __builtin_bswap64(x)
80 #if _BYTE_ORDER == _LITTLE_ENDIAN
81 #define __ntohl(x) (__bswap32(x))
82 #define __ntohs(x) (__bswap16(x))
83 #define __htonl(x) (__bswap32(x))
84 #define __htons(x) (__bswap16(x))
85 #elif _BYTE_ORDER == _BIG_ENDIAN
86 #define __htonl(x) ((__uint32_t)(x))
87 #define __htons(x) ((__uint16_t)(x))
88 #define __ntohl(x) ((__uint32_t)(x))
89 #define __ntohs(x) ((__uint16_t)(x))
92 #endif /* _SYS__ENDIAN_H_ */