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9e7f0924 MD |
1 | #ifndef _BABELTRACE_BITFIELD_H |
2 | #define _BABELTRACE_BITFIELD_H | |
3 | ||
4 | /* | |
5 | * BabelTrace | |
6 | * | |
7 | * Bitfields read/write functions. | |
8 | * | |
9 | * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
10 | * | |
11 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
12 | * of this software and associated documentation files (the "Software"), to deal | |
13 | * in the Software without restriction, including without limitation the rights | |
14 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
15 | * copies of the Software, and to permit persons to whom the Software is | |
16 | * furnished to do so, subject to the following conditions: | |
17 | * | |
18 | * The above copyright notice and this permission notice shall be included in | |
19 | * all copies or substantial portions of the Software. | |
d2428e87 MD |
20 | * |
21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
22 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
24 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
25 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
26 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
27 | * SOFTWARE. | |
9e7f0924 MD |
28 | */ |
29 | ||
9f3fdbc6 MD |
30 | #include <stdint.h> /* C99 5.2.4.2 Numerical limits */ |
31 | #include <limits.h> /* C99 5.2.4.2 Numerical limits */ | |
2ae57758 | 32 | #include <lttng/ust-endian.h> /* Non-standard BIG_ENDIAN, LITTLE_ENDIAN, BYTE_ORDER */ |
9f3fdbc6 | 33 | #include <assert.h> |
9e7f0924 MD |
34 | |
35 | /* We can't shift a int from 32 bit, >> 32 and << 32 on int is undefined */ | |
36 | #define _bt_piecewise_rshift(_v, _shift) \ | |
37 | ({ \ | |
6423c313 MD |
38 | __typeof__(_v) ___v = (_v); \ |
39 | __typeof__(_shift) ___shift = (_shift); \ | |
9e7f0924 MD |
40 | unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1); \ |
41 | unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \ | |
42 | \ | |
43 | for (; sb; sb--) \ | |
44 | ___v >>= sizeof(___v) * CHAR_BIT - 1; \ | |
45 | ___v >>= final; \ | |
46 | }) | |
47 | ||
48 | #define _bt_piecewise_lshift(_v, _shift) \ | |
49 | ({ \ | |
6423c313 MD |
50 | __typeof__(_v) ___v = (_v); \ |
51 | __typeof__(_shift) ___shift = (_shift); \ | |
9e7f0924 MD |
52 | unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1); \ |
53 | unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \ | |
54 | \ | |
55 | for (; sb; sb--) \ | |
56 | ___v <<= sizeof(___v) * CHAR_BIT - 1; \ | |
57 | ___v <<= final; \ | |
58 | }) | |
59 | ||
60 | #define _bt_is_signed_type(type) (((type)(-1)) < 0) | |
61 | ||
62 | #define _bt_unsigned_cast(type, v) \ | |
63 | ({ \ | |
64 | (sizeof(v) < sizeof(type)) ? \ | |
65 | ((type) (v)) & (~(~(type) 0 << (sizeof(v) * CHAR_BIT))) : \ | |
66 | (type) (v); \ | |
67 | }) | |
68 | ||
69 | /* | |
70 | * bt_bitfield_write - write integer to a bitfield in native endianness | |
71 | * | |
72 | * Save integer to the bitfield, which starts at the "start" bit, has "len" | |
73 | * bits. | |
74 | * The inside of a bitfield is from high bits to low bits. | |
75 | * Uses native endianness. | |
76 | * For unsigned "v", pad MSB with 0 if bitfield is larger than v. | |
77 | * For signed "v", sign-extend v if bitfield is larger than v. | |
78 | * | |
79 | * On little endian, bytes are placed from the less significant to the most | |
80 | * significant. Also, consecutive bitfields are placed from lower bits to higher | |
81 | * bits. | |
82 | * | |
83 | * On big endian, bytes are places from most significant to less significant. | |
84 | * Also, consecutive bitfields are placed from higher to lower bits. | |
85 | */ | |
86 | ||
87 | #define _bt_bitfield_write_le(_ptr, type, _start, _length, _v) \ | |
88 | do { \ | |
6423c313 | 89 | __typeof__(_v) __v = (_v); \ |
9e7f0924 MD |
90 | type *__ptr = (void *) (_ptr); \ |
91 | unsigned long __start = (_start), __length = (_length); \ | |
92 | type mask, cmask; \ | |
93 | unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \ | |
94 | unsigned long start_unit, end_unit, this_unit; \ | |
95 | unsigned long end, cshift; /* cshift is "complement shift" */ \ | |
96 | \ | |
97 | if (!__length) \ | |
98 | break; \ | |
99 | \ | |
100 | end = __start + __length; \ | |
101 | start_unit = __start / ts; \ | |
102 | end_unit = (end + (ts - 1)) / ts; \ | |
103 | \ | |
104 | /* Trim v high bits */ \ | |
105 | if (__length < sizeof(__v) * CHAR_BIT) \ | |
6423c313 | 106 | __v &= ~((~(__typeof__(__v)) 0) << __length); \ |
9e7f0924 MD |
107 | \ |
108 | /* We can now append v with a simple "or", shift it piece-wise */ \ | |
109 | this_unit = start_unit; \ | |
110 | if (start_unit == end_unit - 1) { \ | |
111 | mask = ~((~(type) 0) << (__start % ts)); \ | |
112 | if (end % ts) \ | |
113 | mask |= (~(type) 0) << (end % ts); \ | |
114 | cmask = (type) __v << (__start % ts); \ | |
115 | cmask &= ~mask; \ | |
116 | __ptr[this_unit] &= mask; \ | |
117 | __ptr[this_unit] |= cmask; \ | |
118 | break; \ | |
119 | } \ | |
120 | if (__start % ts) { \ | |
121 | cshift = __start % ts; \ | |
122 | mask = ~((~(type) 0) << cshift); \ | |
123 | cmask = (type) __v << cshift; \ | |
124 | cmask &= ~mask; \ | |
125 | __ptr[this_unit] &= mask; \ | |
126 | __ptr[this_unit] |= cmask; \ | |
127 | __v = _bt_piecewise_rshift(__v, ts - cshift); \ | |
128 | __start += ts - cshift; \ | |
129 | this_unit++; \ | |
130 | } \ | |
131 | for (; this_unit < end_unit - 1; this_unit++) { \ | |
132 | __ptr[this_unit] = (type) __v; \ | |
133 | __v = _bt_piecewise_rshift(__v, ts); \ | |
134 | __start += ts; \ | |
135 | } \ | |
136 | if (end % ts) { \ | |
137 | mask = (~(type) 0) << (end % ts); \ | |
138 | cmask = (type) __v; \ | |
139 | cmask &= ~mask; \ | |
140 | __ptr[this_unit] &= mask; \ | |
141 | __ptr[this_unit] |= cmask; \ | |
142 | } else \ | |
143 | __ptr[this_unit] = (type) __v; \ | |
144 | } while (0) | |
145 | ||
146 | #define _bt_bitfield_write_be(_ptr, type, _start, _length, _v) \ | |
147 | do { \ | |
6423c313 | 148 | __typeof__(_v) __v = (_v); \ |
9e7f0924 MD |
149 | type *__ptr = (void *) (_ptr); \ |
150 | unsigned long __start = (_start), __length = (_length); \ | |
151 | type mask, cmask; \ | |
152 | unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \ | |
153 | unsigned long start_unit, end_unit, this_unit; \ | |
154 | unsigned long end, cshift; /* cshift is "complement shift" */ \ | |
155 | \ | |
156 | if (!__length) \ | |
157 | break; \ | |
158 | \ | |
159 | end = __start + __length; \ | |
160 | start_unit = __start / ts; \ | |
161 | end_unit = (end + (ts - 1)) / ts; \ | |
162 | \ | |
163 | /* Trim v high bits */ \ | |
164 | if (__length < sizeof(__v) * CHAR_BIT) \ | |
6423c313 | 165 | __v &= ~((~(__typeof__(__v)) 0) << __length); \ |
9e7f0924 MD |
166 | \ |
167 | /* We can now append v with a simple "or", shift it piece-wise */ \ | |
168 | this_unit = end_unit - 1; \ | |
169 | if (start_unit == end_unit - 1) { \ | |
170 | mask = ~((~(type) 0) << ((ts - (end % ts)) % ts)); \ | |
171 | if (__start % ts) \ | |
172 | mask |= (~((type) 0)) << (ts - (__start % ts)); \ | |
173 | cmask = (type) __v << ((ts - (end % ts)) % ts); \ | |
174 | cmask &= ~mask; \ | |
175 | __ptr[this_unit] &= mask; \ | |
176 | __ptr[this_unit] |= cmask; \ | |
177 | break; \ | |
178 | } \ | |
179 | if (end % ts) { \ | |
180 | cshift = end % ts; \ | |
181 | mask = ~((~(type) 0) << (ts - cshift)); \ | |
182 | cmask = (type) __v << (ts - cshift); \ | |
183 | cmask &= ~mask; \ | |
184 | __ptr[this_unit] &= mask; \ | |
185 | __ptr[this_unit] |= cmask; \ | |
186 | __v = _bt_piecewise_rshift(__v, cshift); \ | |
187 | end -= cshift; \ | |
188 | this_unit--; \ | |
189 | } \ | |
190 | for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \ | |
191 | __ptr[this_unit] = (type) __v; \ | |
192 | __v = _bt_piecewise_rshift(__v, ts); \ | |
193 | end -= ts; \ | |
194 | } \ | |
195 | if (__start % ts) { \ | |
196 | mask = (~(type) 0) << (ts - (__start % ts)); \ | |
197 | cmask = (type) __v; \ | |
198 | cmask &= ~mask; \ | |
199 | __ptr[this_unit] &= mask; \ | |
200 | __ptr[this_unit] |= cmask; \ | |
201 | } else \ | |
202 | __ptr[this_unit] = (type) __v; \ | |
203 | } while (0) | |
204 | ||
205 | /* | |
206 | * bt_bitfield_write - write integer to a bitfield in native endianness | |
207 | * bt_bitfield_write_le - write integer to a bitfield in little endian | |
208 | * bt_bitfield_write_be - write integer to a bitfield in big endian | |
209 | */ | |
210 | ||
9f3fdbc6 | 211 | #if (BYTE_ORDER == LITTLE_ENDIAN) |
9e7f0924 MD |
212 | |
213 | #define bt_bitfield_write(ptr, type, _start, _length, _v) \ | |
214 | _bt_bitfield_write_le(ptr, type, _start, _length, _v) | |
215 | ||
216 | #define bt_bitfield_write_le(ptr, type, _start, _length, _v) \ | |
217 | _bt_bitfield_write_le(ptr, type, _start, _length, _v) | |
218 | ||
219 | #define bt_bitfield_write_be(ptr, type, _start, _length, _v) \ | |
220 | _bt_bitfield_write_be(ptr, unsigned char, _start, _length, _v) | |
221 | ||
9f3fdbc6 | 222 | #elif (BYTE_ORDER == BIG_ENDIAN) |
9e7f0924 MD |
223 | |
224 | #define bt_bitfield_write(ptr, type, _start, _length, _v) \ | |
225 | _bt_bitfield_write_be(ptr, type, _start, _length, _v) | |
226 | ||
227 | #define bt_bitfield_write_le(ptr, type, _start, _length, _v) \ | |
228 | _bt_bitfield_write_le(ptr, unsigned char, _start, _length, _v) | |
229 | ||
230 | #define bt_bitfield_write_be(ptr, type, _start, _length, _v) \ | |
231 | _bt_bitfield_write_be(ptr, type, _start, _length, _v) | |
232 | ||
233 | #else /* (BYTE_ORDER == PDP_ENDIAN) */ | |
234 | ||
235 | #error "Byte order not supported" | |
236 | ||
237 | #endif | |
238 | ||
239 | #define _bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \ | |
240 | do { \ | |
6423c313 MD |
241 | __typeof__(*(_vptr)) *__vptr = (_vptr); \ |
242 | __typeof__(*__vptr) __v; \ | |
9e7f0924 MD |
243 | type *__ptr = (void *) (_ptr); \ |
244 | unsigned long __start = (_start), __length = (_length); \ | |
245 | type mask, cmask; \ | |
246 | unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \ | |
247 | unsigned long start_unit, end_unit, this_unit; \ | |
248 | unsigned long end, cshift; /* cshift is "complement shift" */ \ | |
249 | \ | |
250 | if (!__length) { \ | |
251 | *__vptr = 0; \ | |
252 | break; \ | |
253 | } \ | |
254 | \ | |
255 | end = __start + __length; \ | |
256 | start_unit = __start / ts; \ | |
257 | end_unit = (end + (ts - 1)) / ts; \ | |
258 | \ | |
259 | this_unit = end_unit - 1; \ | |
6423c313 | 260 | if (_bt_is_signed_type(__typeof__(__v)) \ |
9e7f0924 | 261 | && (__ptr[this_unit] & ((type) 1 << ((end % ts ? : ts) - 1)))) \ |
6423c313 | 262 | __v = ~(__typeof__(__v)) 0; \ |
9e7f0924 MD |
263 | else \ |
264 | __v = 0; \ | |
265 | if (start_unit == end_unit - 1) { \ | |
266 | cmask = __ptr[this_unit]; \ | |
267 | cmask >>= (__start % ts); \ | |
268 | if ((end - __start) % ts) { \ | |
269 | mask = ~((~(type) 0) << (end - __start)); \ | |
270 | cmask &= mask; \ | |
271 | } \ | |
272 | __v = _bt_piecewise_lshift(__v, end - __start); \ | |
6423c313 | 273 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
274 | *__vptr = __v; \ |
275 | break; \ | |
276 | } \ | |
277 | if (end % ts) { \ | |
278 | cshift = end % ts; \ | |
279 | mask = ~((~(type) 0) << cshift); \ | |
280 | cmask = __ptr[this_unit]; \ | |
281 | cmask &= mask; \ | |
282 | __v = _bt_piecewise_lshift(__v, cshift); \ | |
6423c313 | 283 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
284 | end -= cshift; \ |
285 | this_unit--; \ | |
286 | } \ | |
287 | for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \ | |
288 | __v = _bt_piecewise_lshift(__v, ts); \ | |
6423c313 | 289 | __v |= _bt_unsigned_cast(__typeof__(__v), __ptr[this_unit]);\ |
9e7f0924 MD |
290 | end -= ts; \ |
291 | } \ | |
292 | if (__start % ts) { \ | |
293 | mask = ~((~(type) 0) << (ts - (__start % ts))); \ | |
294 | cmask = __ptr[this_unit]; \ | |
295 | cmask >>= (__start % ts); \ | |
296 | cmask &= mask; \ | |
297 | __v = _bt_piecewise_lshift(__v, ts - (__start % ts)); \ | |
6423c313 | 298 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
299 | } else { \ |
300 | __v = _bt_piecewise_lshift(__v, ts); \ | |
6423c313 | 301 | __v |= _bt_unsigned_cast(__typeof__(__v), __ptr[this_unit]);\ |
9e7f0924 MD |
302 | } \ |
303 | *__vptr = __v; \ | |
304 | } while (0) | |
305 | ||
306 | #define _bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \ | |
307 | do { \ | |
6423c313 MD |
308 | __typeof__(*(_vptr)) *__vptr = (_vptr); \ |
309 | __typeof__(*__vptr) __v; \ | |
9e7f0924 MD |
310 | type *__ptr = (void *) (_ptr); \ |
311 | unsigned long __start = (_start), __length = (_length); \ | |
312 | type mask, cmask; \ | |
313 | unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \ | |
314 | unsigned long start_unit, end_unit, this_unit; \ | |
315 | unsigned long end, cshift; /* cshift is "complement shift" */ \ | |
316 | \ | |
317 | if (!__length) { \ | |
318 | *__vptr = 0; \ | |
319 | break; \ | |
320 | } \ | |
321 | \ | |
322 | end = __start + __length; \ | |
323 | start_unit = __start / ts; \ | |
324 | end_unit = (end + (ts - 1)) / ts; \ | |
325 | \ | |
326 | this_unit = start_unit; \ | |
6423c313 | 327 | if (_bt_is_signed_type(__typeof__(__v)) \ |
9e7f0924 | 328 | && (__ptr[this_unit] & ((type) 1 << (ts - (__start % ts) - 1)))) \ |
6423c313 | 329 | __v = ~(__typeof__(__v)) 0; \ |
9e7f0924 MD |
330 | else \ |
331 | __v = 0; \ | |
332 | if (start_unit == end_unit - 1) { \ | |
333 | cmask = __ptr[this_unit]; \ | |
334 | cmask >>= (ts - (end % ts)) % ts; \ | |
335 | if ((end - __start) % ts) { \ | |
336 | mask = ~((~(type) 0) << (end - __start)); \ | |
337 | cmask &= mask; \ | |
338 | } \ | |
339 | __v = _bt_piecewise_lshift(__v, end - __start); \ | |
6423c313 | 340 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
341 | *__vptr = __v; \ |
342 | break; \ | |
343 | } \ | |
344 | if (__start % ts) { \ | |
345 | cshift = __start % ts; \ | |
346 | mask = ~((~(type) 0) << (ts - cshift)); \ | |
347 | cmask = __ptr[this_unit]; \ | |
348 | cmask &= mask; \ | |
349 | __v = _bt_piecewise_lshift(__v, ts - cshift); \ | |
6423c313 | 350 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
351 | __start += ts - cshift; \ |
352 | this_unit++; \ | |
353 | } \ | |
354 | for (; this_unit < end_unit - 1; this_unit++) { \ | |
355 | __v = _bt_piecewise_lshift(__v, ts); \ | |
6423c313 | 356 | __v |= _bt_unsigned_cast(__typeof__(__v), __ptr[this_unit]);\ |
9e7f0924 MD |
357 | __start += ts; \ |
358 | } \ | |
359 | if (end % ts) { \ | |
360 | mask = ~((~(type) 0) << (end % ts)); \ | |
361 | cmask = __ptr[this_unit]; \ | |
362 | cmask >>= ts - (end % ts); \ | |
363 | cmask &= mask; \ | |
364 | __v = _bt_piecewise_lshift(__v, end % ts); \ | |
6423c313 | 365 | __v |= _bt_unsigned_cast(__typeof__(__v), cmask); \ |
9e7f0924 MD |
366 | } else { \ |
367 | __v = _bt_piecewise_lshift(__v, ts); \ | |
6423c313 | 368 | __v |= _bt_unsigned_cast(__typeof__(__v), __ptr[this_unit]);\ |
9e7f0924 MD |
369 | } \ |
370 | *__vptr = __v; \ | |
371 | } while (0) | |
372 | ||
373 | /* | |
374 | * bt_bitfield_read - read integer from a bitfield in native endianness | |
375 | * bt_bitfield_read_le - read integer from a bitfield in little endian | |
376 | * bt_bitfield_read_be - read integer from a bitfield in big endian | |
377 | */ | |
378 | ||
9f3fdbc6 | 379 | #if (BYTE_ORDER == LITTLE_ENDIAN) |
9e7f0924 MD |
380 | |
381 | #define bt_bitfield_read(_ptr, type, _start, _length, _vptr) \ | |
382 | _bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) | |
383 | ||
384 | #define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \ | |
385 | _bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) | |
386 | ||
387 | #define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \ | |
388 | _bt_bitfield_read_be(_ptr, unsigned char, _start, _length, _vptr) | |
389 | ||
9f3fdbc6 | 390 | #elif (BYTE_ORDER == BIG_ENDIAN) |
9e7f0924 MD |
391 | |
392 | #define bt_bitfield_read(_ptr, type, _start, _length, _vptr) \ | |
393 | _bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) | |
394 | ||
395 | #define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \ | |
396 | _bt_bitfield_read_le(_ptr, unsigned char, _start, _length, _vptr) | |
397 | ||
398 | #define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \ | |
399 | _bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) | |
400 | ||
9f3fdbc6 | 401 | #else /* (BYTE_ORDER == PDP_ENDIAN) */ |
9e7f0924 MD |
402 | |
403 | #error "Byte order not supported" | |
404 | ||
405 | #endif | |
406 | ||
407 | #endif /* _BABELTRACE_BITFIELD_H */ |