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Norman James6a58a272015-10-07 14:34:16 -05001/* CC0 (Public domain) - see LICENSE file for details */
2#ifndef CCAN_ENDIAN_H
3#define CCAN_ENDIAN_H
4#include <stdint.h>
5#include "config.h"
6
7/**
8 * BSWAP_16 - reverse bytes in a constant uint16_t value.
9 * @val: constant value whose bytes to swap.
10 *
11 * Designed to be usable in constant-requiring initializers.
12 *
13 * Example:
14 * struct mystruct {
15 * char buf[BSWAP_16(0x1234)];
16 * };
17 */
18#define BSWAP_16(val) \
19 ((((uint16_t)val & 0x00ff) << 8) \
20 | (((uint16_t)val & 0xff00) >> 8))
21
22/**
23 * BSWAP_32 - reverse bytes in a constant uint32_t value.
24 * @val: constant value whose bytes to swap.
25 *
26 * Designed to be usable in constant-requiring initializers.
27 *
28 * Example:
29 * struct mystruct {
30 * char buf[BSWAP_32(0xff000000)];
31 * };
32 */
33#define BSWAP_32(val) \
34 ((((uint32_t)val & 0x000000ff) << 24) \
35 | (((uint32_t)val & 0x0000ff00) << 8) \
36 | (((uint32_t)val & 0x00ff0000) >> 8) \
37 | (((uint32_t)val & 0xff000000) >> 24))
38
39/**
40 * BSWAP_64 - reverse bytes in a constant uint64_t value.
41 * @val: constantvalue whose bytes to swap.
42 *
43 * Designed to be usable in constant-requiring initializers.
44 *
45 * Example:
46 * struct mystruct {
47 * char buf[BSWAP_64(0xff00000000000000ULL)];
48 * };
49 */
50#define BSWAP_64(val) \
51 ((((uint64_t)val & 0x00000000000000ffULL) << 56) \
52 | (((uint64_t)val & 0x000000000000ff00ULL) << 40) \
53 | (((uint64_t)val & 0x0000000000ff0000ULL) << 24) \
54 | (((uint64_t)val & 0x00000000ff000000ULL) << 8) \
55 | (((uint64_t)val & 0x000000ff00000000ULL) >> 8) \
56 | (((uint64_t)val & 0x0000ff0000000000ULL) >> 24) \
57 | (((uint64_t)val & 0x00ff000000000000ULL) >> 40) \
58 | (((uint64_t)val & 0xff00000000000000ULL) >> 56))
59
60#if HAVE_BYTESWAP_H
61#include <byteswap.h>
62#else
63/**
64 * bswap_16 - reverse bytes in a uint16_t value.
65 * @val: value whose bytes to swap.
66 *
67 * Example:
68 * // Output contains "1024 is 4 as two bytes reversed"
69 * printf("1024 is %u as two bytes reversed\n", bswap_16(1024));
70 */
71static inline uint16_t bswap_16(uint16_t val)
72{
73 return BSWAP_16(val);
74}
75
76/**
77 * bswap_32 - reverse bytes in a uint32_t value.
78 * @val: value whose bytes to swap.
79 *
80 * Example:
81 * // Output contains "1024 is 262144 as four bytes reversed"
82 * printf("1024 is %u as four bytes reversed\n", bswap_32(1024));
83 */
84static inline uint32_t bswap_32(uint32_t val)
85{
86 return BSWAP_32(val);
87}
88#endif /* !HAVE_BYTESWAP_H */
89
90#if !HAVE_BSWAP_64
91/**
92 * bswap_64 - reverse bytes in a uint64_t value.
93 * @val: value whose bytes to swap.
94 *
95 * Example:
96 * // Output contains "1024 is 1125899906842624 as eight bytes reversed"
97 * printf("1024 is %llu as eight bytes reversed\n",
98 * (unsigned long long)bswap_64(1024));
99 */
100static inline uint64_t bswap_64(uint64_t val)
101{
102 return BSWAP_64(val);
103}
104#endif
105
106/* Sanity check the defines. We don't handle weird endianness. */
107#if !HAVE_LITTLE_ENDIAN && !HAVE_BIG_ENDIAN
108#error "Unknown endian"
109#elif HAVE_LITTLE_ENDIAN && HAVE_BIG_ENDIAN
110#error "Can't compile for both big and little endian."
111#endif
112
113#if HAVE_LITTLE_ENDIAN
114/**
115 * CPU_TO_LE64 - convert a constant uint64_t value to little-endian
116 * @native: constant to convert
117 */
118#define CPU_TO_LE64(native) (native)
119
120/**
121 * CPU_TO_LE32 - convert a constant uint32_t value to little-endian
122 * @native: constant to convert
123 */
124#define CPU_TO_LE32(native) (native)
125
126/**
127 * CPU_TO_LE16 - convert a constant uint16_t value to little-endian
128 * @native: constant to convert
129 */
130#define CPU_TO_LE16(native) (native)
131
132/**
133 * LE64_TO_CPU - convert a little-endian uint64_t constant
134 * @le_val: little-endian constant to convert
135 */
136#define LE64_TO_CPU(le_val) (le_val)
137
138/**
139 * LE32_TO_CPU - convert a little-endian uint32_t constant
140 * @le_val: little-endian constant to convert
141 */
142#define LE32_TO_CPU(le_val) (le_val)
143
144/**
145 * LE16_TO_CPU - convert a little-endian uint16_t constant
146 * @le_val: little-endian constant to convert
147 */
148#define LE16_TO_CPU(le_val) (le_val)
149
150#else /* ... HAVE_BIG_ENDIAN */
151#define CPU_TO_LE64(native) BSWAP_64(native)
152#define CPU_TO_LE32(native) BSWAP_32(native)
153#define CPU_TO_LE16(native) BSWAP_16(native)
154#define LE64_TO_CPU(le_val) BSWAP_64(le_val)
155#define LE32_TO_CPU(le_val) BSWAP_32(le_val)
156#define LE16_TO_CPU(le_val) BSWAP_16(le_val)
157#endif /* HAVE_BIG_ENDIAN */
158
159#if HAVE_BIG_ENDIAN
160/**
161 * CPU_TO_BE64 - convert a constant uint64_t value to big-endian
162 * @native: constant to convert
163 */
164#define CPU_TO_BE64(native) (native)
165
166/**
167 * CPU_TO_BE32 - convert a constant uint32_t value to big-endian
168 * @native: constant to convert
169 */
170#define CPU_TO_BE32(native) (native)
171
172/**
173 * CPU_TO_BE16 - convert a constant uint16_t value to big-endian
174 * @native: constant to convert
175 */
176#define CPU_TO_BE16(native) (native)
177
178/**
179 * BE64_TO_CPU - convert a big-endian uint64_t constant
180 * @le_val: big-endian constant to convert
181 */
182#define BE64_TO_CPU(le_val) (le_val)
183
184/**
185 * BE32_TO_CPU - convert a big-endian uint32_t constant
186 * @le_val: big-endian constant to convert
187 */
188#define BE32_TO_CPU(le_val) (le_val)
189
190/**
191 * BE16_TO_CPU - convert a big-endian uint16_t constant
192 * @le_val: big-endian constant to convert
193 */
194#define BE16_TO_CPU(le_val) (le_val)
195
196#else /* ... HAVE_LITTLE_ENDIAN */
197#define CPU_TO_BE64(native) BSWAP_64(native)
198#define CPU_TO_BE32(native) BSWAP_32(native)
199#define CPU_TO_BE16(native) BSWAP_16(native)
200#define BE64_TO_CPU(le_val) BSWAP_64(le_val)
201#define BE32_TO_CPU(le_val) BSWAP_32(le_val)
202#define BE16_TO_CPU(le_val) BSWAP_16(le_val)
203#endif /* HAVE_LITTE_ENDIAN */
204
205
206/**
207 * cpu_to_le64 - convert a uint64_t value to little-endian
208 * @native: value to convert
209 */
210static inline uint64_t cpu_to_le64(uint64_t native)
211{
212 return CPU_TO_LE64(native);
213}
214
215/**
216 * cpu_to_le32 - convert a uint32_t value to little-endian
217 * @native: value to convert
218 */
219static inline uint32_t cpu_to_le32(uint32_t native)
220{
221 return CPU_TO_LE32(native);
222}
223
224/**
225 * cpu_to_le16 - convert a uint16_t value to little-endian
226 * @native: value to convert
227 */
228static inline uint16_t cpu_to_le16(uint16_t native)
229{
230 return CPU_TO_LE16(native);
231}
232
233/**
234 * le64_to_cpu - convert a little-endian uint64_t value
235 * @le_val: little-endian value to convert
236 */
237static inline uint64_t le64_to_cpu(uint64_t le_val)
238{
239 return LE64_TO_CPU(le_val);
240}
241
242/**
243 * le32_to_cpu - convert a little-endian uint32_t value
244 * @le_val: little-endian value to convert
245 */
246static inline uint32_t le32_to_cpu(uint32_t le_val)
247{
248 return LE32_TO_CPU(le_val);
249}
250
251/**
252 * le16_to_cpu - convert a little-endian uint16_t value
253 * @le_val: little-endian value to convert
254 */
255static inline uint16_t le16_to_cpu(uint16_t le_val)
256{
257 return LE16_TO_CPU(le_val);
258}
259
260/**
261 * cpu_to_be64 - convert a uint64_t value to big endian.
262 * @native: value to convert
263 */
264static inline uint64_t cpu_to_be64(uint64_t native)
265{
266 return CPU_TO_BE64(native);
267}
268
269/**
270 * cpu_to_be32 - convert a uint32_t value to big endian.
271 * @native: value to convert
272 */
273static inline uint32_t cpu_to_be32(uint32_t native)
274{
275 return CPU_TO_BE32(native);
276}
277
278/**
279 * cpu_to_be16 - convert a uint16_t value to big endian.
280 * @native: value to convert
281 */
282static inline uint16_t cpu_to_be16(uint16_t native)
283{
284 return CPU_TO_BE16(native);
285}
286
287/**
288 * be64_to_cpu - convert a big-endian uint64_t value
289 * @be_val: big-endian value to convert
290 */
291static inline uint64_t be64_to_cpu(uint64_t be_val)
292{
293 return BE64_TO_CPU(be_val);
294}
295
296/**
297 * be32_to_cpu - convert a big-endian uint32_t value
298 * @be_val: big-endian value to convert
299 */
300static inline uint32_t be32_to_cpu(uint32_t be_val)
301{
302 return BE32_TO_CPU(be_val);
303}
304
305/**
306 * be16_to_cpu - convert a big-endian uint16_t value
307 * @be_val: big-endian value to convert
308 */
309static inline uint16_t be16_to_cpu(uint16_t be_val)
310{
311 return BE16_TO_CPU(be_val);
312}
313
314#endif /* CCAN_ENDIAN_H */