xref: /freebsd/sys/sys/_endian.h (revision 1314d14c32713b448738cc821c04a5e7482bb4af)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 1991 Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
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.
18  *
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
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS__ENDIAN_H_
33 #define	_SYS__ENDIAN_H_
34 
35 #if !defined(_MACHINE_ENDIAN_H_) && !defined(_BYTESWAP_H_) && !defined(_ENDIAN_H_)
36 #error "sys/_endian.h should not be included directly"
37 #endif
38 
39 #include <sys/cdefs.h>				/* visibility macros */
40 
41 /* BSD Compatibility */
42 #define	_BYTE_ORDER	__BYTE_ORDER__
43 
44 /*
45  * Definitions for byte order, according to byte significance from low
46  * address to high. We undefine any prior definition of them because
47  * powerpc compilers define _LITTLE_ENDIAN and _BIG_ENDIAN to mean
48  * something else.
49  */
50 #undef _LITTLE_ENDIAN
51 #define	_LITTLE_ENDIAN	__ORDER_LITTLE_ENDIAN__ /* LSB first: 1234 */
52 #undef _BIG_ENDIAN
53 #define	_BIG_ENDIAN	__ORDER_BIG_ENDIAN__    /* MSB first: 4321 */
54 #define	_PDP_ENDIAN	__ORDER_PDP_ENDIAN__    /* LSB first in word,
55 						 * MSW first in long: 3412 */
56 
57 /*
58  * Define the order of 32-bit words in 64-bit words.
59  */
60 #if _BYTE_ORDER == _LITTLE_ENDIAN
61 #define	_QUAD_HIGHWORD	1
62 #define	_QUAD_LOWWORD	0
63 #elif _BYTE_ORDER == _BIG_ENDIAN
64 #define	_QUAD_HIGHWORD	0
65 #define	_QUAD_LOWWORD	1
66 #else
67 #error "Unsupported endian"
68 #endif
69 
70 /*
71  * POSIX Issue 8 will require these for endian.h. Define them there and in the
72  * traditional BSD compilation environment. PDP_ENDIAN isn't strictly in Issue
73  * 8, but is allowed as implementations can define any *_ENDIAN symbol. Since
74  * issue 8 doesn't yet have an assigned date, use strictly greater than issue
75  * 7's date.
76  */
77 #if __BSD_VISIBLE || _POSIX_C_SOURCE > 200809
78 #define	LITTLE_ENDIAN   _LITTLE_ENDIAN
79 #define	BIG_ENDIAN      _BIG_ENDIAN
80 #define	PDP_ENDIAN      _PDP_ENDIAN
81 #define	BYTE_ORDER      _BYTE_ORDER
82 #endif
83 
84 /* bswap primitives, based on compiler builtins */
85 #define	__bswap16(x)	__builtin_bswap16(x)
86 #define	__bswap32(x)	__builtin_bswap32(x)
87 #define	__bswap64(x)	__builtin_bswap64(x)
88 
89 #if _BYTE_ORDER == _LITTLE_ENDIAN
90 #define	__ntohl(x)	(__bswap32(x))
91 #define	__ntohs(x)	(__bswap16(x))
92 #define	__htonl(x)	(__bswap32(x))
93 #define	__htons(x)	(__bswap16(x))
94 #elif _BYTE_ORDER == _BIG_ENDIAN
95 #define	__htonl(x)	((__uint32_t)(x))
96 #define	__htons(x)	((__uint16_t)(x))
97 #define	__ntohl(x)	((__uint32_t)(x))
98 #define	__ntohs(x)	((__uint16_t)(x))
99 #endif
100 
101 /*
102  * Host to big endian, host to little endian, big endian to host, and little
103  * endian to host byte order functions as detailed in byteorder(9).
104  */
105 #if _BYTE_ORDER == _LITTLE_ENDIAN
106 #define	htobe16(x)	__bswap16((x))
107 #define	htobe32(x)	__bswap32((x))
108 #define	htobe64(x)	__bswap64((x))
109 #define	htole16(x)	((uint16_t)(x))
110 #define	htole32(x)	((uint32_t)(x))
111 #define	htole64(x)	((uint64_t)(x))
112 
113 #define	be16toh(x)	__bswap16((x))
114 #define	be32toh(x)	__bswap32((x))
115 #define	be64toh(x)	__bswap64((x))
116 #define	le16toh(x)	((uint16_t)(x))
117 #define	le32toh(x)	((uint32_t)(x))
118 #define	le64toh(x)	((uint64_t)(x))
119 #else /* _BYTE_ORDER != _LITTLE_ENDIAN */
120 #define	htobe16(x)	((uint16_t)(x))
121 #define	htobe32(x)	((uint32_t)(x))
122 #define	htobe64(x)	((uint64_t)(x))
123 #define	htole16(x)	__bswap16((x))
124 #define	htole32(x)	__bswap32((x))
125 #define	htole64(x)	__bswap64((x))
126 
127 #define	be16toh(x)	((uint16_t)(x))
128 #define	be32toh(x)	((uint32_t)(x))
129 #define	be64toh(x)	((uint64_t)(x))
130 #define	le16toh(x)	__bswap16((x))
131 #define	le32toh(x)	__bswap32((x))
132 #define	le64toh(x)	__bswap64((x))
133 #endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
134 
135 #endif /* _SYS__ENDIAN_H_ */
136