xref: /openbsd/sys/sys/_endian.h (revision 10ecf0c3)
1 /*	$OpenBSD: _endian.h,v 1.8 2018/01/11 23:13:37 dlg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 Niklas Hallqvist.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  * Internal endianness macros.  This pulls in <machine/endian.h> to
29  * get the correct setting direction for the platform and sets internal
30  * ('__' prefix) macros appropriately.
31  */
32 
33 #ifndef _SYS__ENDIAN_H_
34 #define _SYS__ENDIAN_H_
35 
36 #include <sys/_types.h>
37 
38 #define __FROM_SYS__ENDIAN
39 #include <machine/endian.h>
40 #undef __FROM_SYS__ENDIAN
41 
42 #define _LITTLE_ENDIAN	1234
43 #define _BIG_ENDIAN	4321
44 #define _PDP_ENDIAN	3412
45 
46 /* Note that these macros evaluate their arguments several times.  */
47 
48 #define __swap16gen(x)							\
49     (__uint16_t)(((__uint16_t)(x) & 0xffU) << 8 | ((__uint16_t)(x) & 0xff00U) >> 8)
50 
51 #define __swap32gen(x)							\
52     (__uint32_t)(((__uint32_t)(x) & 0xff) << 24 |			\
53     ((__uint32_t)(x) & 0xff00) << 8 | ((__uint32_t)(x) & 0xff0000) >> 8 |\
54     ((__uint32_t)(x) & 0xff000000) >> 24)
55 
56 #define __swap64gen(x)							\
57 	(__uint64_t)((((__uint64_t)(x) & 0xff) << 56) |			\
58 	    ((__uint64_t)(x) & 0xff00ULL) << 40 |			\
59 	    ((__uint64_t)(x) & 0xff0000ULL) << 24 |			\
60 	    ((__uint64_t)(x) & 0xff000000ULL) << 8 |			\
61 	    ((__uint64_t)(x) & 0xff00000000ULL) >> 8 |			\
62 	    ((__uint64_t)(x) & 0xff0000000000ULL) >> 24 |		\
63 	    ((__uint64_t)(x) & 0xff000000000000ULL) >> 40 |		\
64 	    ((__uint64_t)(x) & 0xff00000000000000ULL) >> 56)
65 
66 #ifndef __HAVE_MD_SWAP
67 static __inline __uint16_t
__swap16md(__uint16_t x)68 __swap16md(__uint16_t x)
69 {
70 	return (__swap16gen(x));
71 }
72 
73 static __inline __uint32_t
__swap32md(__uint32_t x)74 __swap32md(__uint32_t x)
75 {
76 	return (__swap32gen(x));
77 }
78 
79 static __inline __uint64_t
__swap64md(__uint64_t x)80 __swap64md(__uint64_t x)
81 {
82 	return (__swap64gen(x));
83 }
84 #endif
85 
86 #define __swap16(x)							\
87 	(__uint16_t)(__builtin_constant_p(x) ? __swap16gen(x) : __swap16md(x))
88 #define __swap32(x)							\
89 	(__uint32_t)(__builtin_constant_p(x) ? __swap32gen(x) : __swap32md(x))
90 #define __swap64(x)							\
91 	(__uint64_t)(__builtin_constant_p(x) ? __swap64gen(x) : __swap64md(x))
92 
93 #if _BYTE_ORDER == _LITTLE_ENDIAN
94 
95 #define _QUAD_HIGHWORD 1
96 #define _QUAD_LOWWORD 0
97 
98 #define __htobe16	__swap16
99 #define __htobe32	__swap32
100 #define __htobe64	__swap64
101 #define __htole16(x)	((__uint16_t)(x))
102 #define __htole32(x)	((__uint32_t)(x))
103 #define __htole64(x)	((__uint64_t)(x))
104 
105 #ifdef _KERNEL
106 #ifdef __HAVE_MD_SWAPIO
107 
108 #define __bemtoh16(_x) __mswap16(_x)
109 #define __bemtoh32(_x) __mswap32(_x)
110 #define __bemtoh64(_x) __mswap64(_x)
111 
112 #define __htobem16(_x, _v) __swapm16((_x), (_v))
113 #define __htobem32(_x, _v) __swapm32((_x), (_v))
114 #define __htobem64(_x, _v) __swapm64((_x), (_v))
115 
116 #endif /* __HAVE_MD_SWAPIO */
117 #endif /* _KERNEL */
118 #endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
119 
120 #if _BYTE_ORDER == _BIG_ENDIAN
121 
122 #define _QUAD_HIGHWORD 0
123 #define _QUAD_LOWWORD 1
124 
125 #define __htobe16(x)	((__uint16_t)(x))
126 #define __htobe32(x)	((__uint32_t)(x))
127 #define __htobe64(x)	((__uint64_t)(x))
128 #define __htole16	__swap16
129 #define __htole32	__swap32
130 #define __htole64	__swap64
131 
132 #ifdef _KERNEL
133 #ifdef __HAVE_MD_SWAPIO
134 
135 #define __lemtoh16(_x) __mswap16(_x)
136 #define __lemtoh32(_x) __mswap32(_x)
137 #define __lemtoh64(_x) __mswap64(_x)
138 
139 #define __htolem16(_x, _v) __swapm16((_x), (_v))
140 #define __htolem32(_x, _v) __swapm32((_x), (_v))
141 #define __htolem64(_x, _v) __swapm64((_x), (_v))
142 
143 #endif /* __HAVE_MD_SWAPIO */
144 #endif /* _KERNEL */
145 #endif /* _BYTE_ORDER == _BIG_ENDIAN */
146 
147 
148 #ifdef _KERNEL
149 /*
150  * Fill in the __hto[bl]em{16,32,64} and __[bl]emtoh{16,32,64} macros
151  * that haven't been defined yet
152  */
153 
154 #ifndef __bemtoh16
155 #define __bemtoh16(_x)		__htobe16(*(__uint16_t *)(_x))
156 #define __bemtoh32(_x)		__htobe32(*(__uint32_t *)(_x))
157 #define __bemtoh64(_x)		__htobe64(*(__uint64_t *)(_x))
158 #endif
159 
160 #ifndef __htobem16
161 #define __htobem16(_x, _v)	(*(__uint16_t *)(_x) = __htobe16(_v))
162 #define __htobem32(_x, _v)	(*(__uint32_t *)(_x) = __htobe32(_v))
163 #define __htobem64(_x, _v)	(*(__uint64_t *)(_x) = __htobe64(_v))
164 #endif
165 
166 #ifndef __lemtoh16
167 #define __lemtoh16(_x)		__htole16(*(__uint16_t *)(_x))
168 #define __lemtoh32(_x)		__htole32(*(__uint32_t *)(_x))
169 #define __lemtoh64(_x)		__htole64(*(__uint64_t *)(_x))
170 #endif
171 
172 #ifndef __htolem16
173 #define __htolem16(_x, _v)	(*(__uint16_t *)(_x) = __htole16(_v))
174 #define __htolem32(_x, _v)	(*(__uint32_t *)(_x) = __htole32(_v))
175 #define __htolem64(_x, _v)	(*(__uint64_t *)(_x) = __htole64(_v))
176 #endif
177 #endif /* _KERNEL */
178 
179 #endif /* _SYS__ENDIAN_H_ */
180