endian.h
Go to the documentation of this file.
1 /*
2  * Copyright (C) 2024 Otto-von-Guericke-Universität Magdeburg
3  *
4  * This file is subject to the terms and conditions of the GNU Lesser General
5  * Public License v2.1. See the file LICENSE in the top level directory for more
6  * details.
7  */
8 
23 #ifndef ENDIAN_H
24 #define ENDIAN_H
25 
26 #include <stdint.h>
27 
28 #ifdef __cplusplus
29 extern "C" {
30 #endif
31 
32 #ifdef DOXYGEN
36 #define LITTLE_ENDIAN magic-number
37 
41 #define BIG_ENDIAN magic-number
42 
46 #define PDP_ENDIAN magic-number
47 
56 #define BYTE_ORDER <LITTLE_ENDIAN or BIG_ENDIAN>
57 
58 uint16_t htobe16(uint16_t host_16bits);
59 uint16_t htole16(uint16_t host_16bits);
60 uint16_t be16toh(uint16_t big_endian_16bits);
61 uint16_t le16toh(uint16_t little_endian_16bits);
63 uint32_t htobe32(uint32_t host_32bits);
64 uint32_t htole32(uint32_t host_32bits);
65 uint32_t be32toh(uint32_t big_endian_32bits);
66 uint32_t le32toh(uint32_t little_endian_32bits);
68 uint64_t htobe64(uint64_t host_64bits);
69 uint64_t htole64(uint64_t host_64bits);
70 uint64_t be64toh(uint64_t big_endian_64bits);
71 uint64_t le64toh(uint64_t little_endian_64bits);
73 #else /* DOXYGEN */
74 
75 /* Depending on the version of newlib used, newlib may provide them indirectly
76  * as well. We don't want to redefine them in this case */
77 #ifndef LITTLE_ENDIAN
78 # define LITTLE_ENDIAN 1234
79 #endif
80 #ifndef BIG_ENDIAN
81 # define BIG_ENDIAN 4321
82 #endif
83 #ifndef PDP_ENDIAN
84 # define PDP_ENDIAN 3412
85 #endif
86 #ifndef BYTE_ORDER
87 # define BYTE_ORDER __BYTE_ORDER__
88 #endif
89 
90 /* But to avoid lots of pain in the ass: Let's at least make sure everyone
91  * agrees on what magic number is what */
92 #if (LITTLE_ENDIAN != 1234) || (BIG_ENDIAN != 4321) || (PDP_ENDIAN != 3412)
93 # error "Mismatching magic numbers to refer to endianness"
94 #endif
95 
96 #if BYTE_ORDER == LITTLE_ENDIAN
97 # ifndef htobe16
98 # define htobe16(_x) __builtin_bswap16(_x)
99 # endif
100 # ifndef htole16
101 # define htole16(_x) ((uint16_t)(_x))
102 # endif
103 # ifndef be16toh
104 # define be16toh(_x) __builtin_bswap16(_x)
105 # endif
106 # ifndef le16toh
107 # define le16toh(_x) ((uint16_t)(_x))
108 # endif
109 # ifndef htobe32
110 # define htobe32(_x) __builtin_bswap32(_x)
111 # endif
112 # ifndef htole32
113 # define htole32(_x) ((uint32_t)(_x))
114 # endif
115 # ifndef be32toh
116 # define be32toh(_x) __builtin_bswap32(_x)
117 # endif
118 # ifndef le32toh
119 # define le32toh(_x) ((uint32_t)(_x))
120 # endif
121 # ifndef htobe64
122 # define htobe64(_x) __builtin_bswap64(_x)
123 # endif
124 # ifndef htole64
125 # define htole64(_x) ((uint64_t)(_x))
126 # endif
127 # ifndef be64toh
128 # define be64toh(_x) __builtin_bswap64(_x)
129 # endif
130 # ifndef le64toh
131 # define le64toh(_x) ((uint64_t)(_x))
132 # endif
133 #elif BYTE_ORDER == BIG_ENDIAN
134 # ifndef htole16
135 # define htole16(_x) __builtin_bswap16(_x)
136 # endif
137 # ifndef htobe16
138 # define htobe16(_x) ((uint16_t)(_x))
139 # endif
140 # ifndef le16toh
141 # define le16toh(_x) __builtin_bswap16(_x)
142 # endif
143 # ifndef be16toh
144 # define be16toh(_x) ((uint16_t)(_x))
145 # endif
146 # ifndef htole32
147 # define htole32(_x) __builtin_bswap32(_x)
148 # endif
149 # ifndef htobe32
150 # define htobe32(_x) ((uint32_t)(_x))
151 # endif
152 # ifndef le32toh
153 # define le32toh(_x) __builtin_bswap32(_x)
154 # endif
155 # ifndef be32toh
156 # define be32toh(_x) ((uint32_t)(_x))
157 # endif
158 # ifndef htole64
159 # define htole64(_x) __builtin_bswap64(_x)
160 # endif
161 # ifndef htobe64
162 # define htobe64(_x) ((uint64_t)(_x))
163 # endif
164 # ifndef le64toh
165 # define le64toh(_x) __builtin_bswap64(_x)
166 # endif
167 # ifndef be64toh
168 # define be64toh(_x) ((uint64_t)(_x))
169 # endif
170 #else
171 # error "Byte order not supported"
172 #endif
173 
174 #endif /* DOXYGEN */
175 
176 #ifdef __cplusplus
177 }
178 #endif
179 
180 #endif /* ENDIAN_H */
be16toh
uint16_t be16toh(uint16_t big_endian_16bits)
big endian to host, 16 bit
htobe16
uint16_t htobe16(uint16_t host_16bits)
host to big endian, 16 bit
le32toh
uint32_t le32toh(uint32_t little_endian_32bits)
little endian to host, 32 bit
htobe32
uint32_t htobe32(uint32_t host_32bits)
host to big endian, 32 bit
le16toh
uint16_t le16toh(uint16_t little_endian_16bits)
little endian to host, 16 bit
htobe64
uint64_t htobe64(uint64_t host_64bits)
host to big endian, 64 bit
be64toh
uint64_t be64toh(uint64_t big_endian_64bits)
big endian to host, 64 bit
be32toh
uint32_t be32toh(uint32_t big_endian_32bits)
big endian to host, 32 bit
htole64
uint64_t htole64(uint64_t host_64bits)
host to little endian, 64 bit
htole32
uint32_t htole32(uint32_t host_32bits)
host to little endian, 32 bit
htole16
uint16_t htole16(uint16_t host_16bits)
host to little endian, 16 bit
le64toh
uint64_t le64toh(uint64_t little_endian_64bits)
little endian to host, 64 bit