1/* 2 * Mesa 3-D graphics library 3 * 4 * Copyright (C) 2006 Brian Paul All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included 14 * in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25/** 26 * \file bitset.h 27 * \brief Bitset of arbitrary size definitions. 28 * \author Michal Krol 29 */ 30 31#ifndef BITSET_H 32#define BITSET_H 33 34#include "util/bitscan.h" 35#include "util/macros.h" 36 37/**************************************************************************** 38 * generic bitset implementation 39 */ 40 41#define BITSET_WORD unsigned int 42#define BITSET_WORDBITS (sizeof (BITSET_WORD) * 8) 43 44/* bitset declarations 45 */ 46#define BITSET_WORDS(bits) (((bits) + BITSET_WORDBITS - 1) / BITSET_WORDBITS) 47#define BITSET_DECLARE(name, bits) BITSET_WORD name[BITSET_WORDS(bits)] 48 49/* bitset operations 50 */ 51#define BITSET_COPY(x, y) memcpy( (x), (y), sizeof (x) ) 52#define BITSET_EQUAL(x, y) (memcmp( (x), (y), sizeof (x) ) == 0) 53#define BITSET_ZERO(x) memset( (x), 0, sizeof (x) ) 54#define BITSET_ONES(x) memset( (x), 0xff, sizeof (x) ) 55#define BITSET_SIZE(x) (8 * sizeof(x)) // bitset size in bits 56 57#define BITSET_BITWORD(b) ((b) / BITSET_WORDBITS) 58#define BITSET_BIT(b) (1u << ((b) % BITSET_WORDBITS)) 59 60/* single bit operations 61 */ 62#define BITSET_TEST(x, b) (((x)[BITSET_BITWORD(b)] & BITSET_BIT(b)) != 0) 63#define BITSET_SET(x, b) ((x)[BITSET_BITWORD(b)] |= BITSET_BIT(b)) 64#define BITSET_CLEAR(x, b) ((x)[BITSET_BITWORD(b)] &= ~BITSET_BIT(b)) 65 66#define BITSET_MASK(b) (((b) % BITSET_WORDBITS == 0) ? ~0 : BITSET_BIT(b) - 1) 67#define BITSET_RANGE(b, e) ((BITSET_MASK((e) + 1)) & ~(BITSET_BIT(b) - 1)) 68 69/* logic bit operations 70 */ 71static inline void 72__bitset_and(BITSET_WORD *r, const BITSET_WORD *x, const BITSET_WORD *y, unsigned n) 73{ 74 for (unsigned i = 0; i < n; i++) 75 r[i] = x[i] & y[i]; 76} 77 78static inline void 79__bitset_or(BITSET_WORD *r, const BITSET_WORD *x, const BITSET_WORD *y, unsigned n) 80{ 81 for (unsigned i = 0; i < n; i++) 82 r[i] = x[i] | y[i]; 83} 84 85static inline void 86__bitset_not(BITSET_WORD *x, unsigned n) 87{ 88 for (unsigned i = 0; i < n; i++) 89 x[i] = ~x[i]; 90} 91 92#define BITSET_AND(r, x, y) \ 93 do { \ 94 assert(ARRAY_SIZE(r) == ARRAY_SIZE(x)); \ 95 assert(ARRAY_SIZE(r) == ARRAY_SIZE(y)); \ 96 __bitset_and(r, x, y, ARRAY_SIZE(r)); \ 97 } while (0) 98 99#define BITSET_OR(r, x, y) \ 100 do { \ 101 assert(ARRAY_SIZE(r) == ARRAY_SIZE(x)); \ 102 assert(ARRAY_SIZE(r) == ARRAY_SIZE(y)); \ 103 __bitset_or(r, x, y, ARRAY_SIZE(r)); \ 104 } while (0) 105 106#define BITSET_NOT(x) \ 107 __bitset_not(x, ARRAY_SIZE(x)) 108 109static inline void 110__bitset_rotate_right(BITSET_WORD *x, unsigned amount, unsigned n) 111{ 112 assert(amount < BITSET_WORDBITS); 113 114 if (amount == 0) 115 return; 116 117 for (unsigned i = 0; i < n - 1; i++) { 118 x[i] = (x[i] >> amount) | (x[i + 1] << (BITSET_WORDBITS - amount)); 119 } 120 121 x[n - 1] = x[n - 1] >> amount; 122} 123 124static inline void 125__bitset_rotate_left(BITSET_WORD *x, unsigned amount, unsigned n) 126{ 127 assert(amount < BITSET_WORDBITS); 128 129 if (amount == 0) 130 return; 131 132 for (int i = n - 1; i > 0; i--) { 133 x[i] = (x[i] << amount) | (x[i - 1] >> (BITSET_WORDBITS - amount)); 134 } 135 136 x[0] = x[0] << amount; 137} 138 139static inline void 140__bitset_shr(BITSET_WORD *x, unsigned amount, unsigned n) 141{ 142 const unsigned int words = amount / BITSET_WORDBITS; 143 144 if (amount == 0) 145 return; 146 147 if (words) { 148 unsigned i; 149 150 for (i = 0; i < n - words; i++) 151 x[i] = x[i + words]; 152 153 while (i < n) 154 x[i++] = 0; 155 156 amount %= BITSET_WORDBITS; 157 } 158 159 __bitset_rotate_right(x, amount, n); 160} 161 162 163static inline void 164__bitset_shl(BITSET_WORD *x, unsigned amount, unsigned n) 165{ 166 const int words = amount / BITSET_WORDBITS; 167 168 if (amount == 0) 169 return; 170 171 if (words) { 172 int i; 173 174 for (i = n - 1; i >= words; i--) { 175 x[i] = x[i - words]; 176 } 177 178 while (i >= 0) { 179 x[i--] = 0; 180 } 181 182 amount %= BITSET_WORDBITS; 183 } 184 185 __bitset_rotate_left(x, amount, n); 186} 187 188#define BITSET_SHR(x, n) \ 189 __bitset_shr(x, n, ARRAY_SIZE(x)); 190 191#define BITSET_SHL(x, n) \ 192 __bitset_shl(x, n, ARRAY_SIZE(x)); 193 194/* bit range operations 195 */ 196#define BITSET_TEST_RANGE_INSIDE_WORD(x, b, e) \ 197 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 198 (((x)[BITSET_BITWORD(b)] & BITSET_RANGE(b, e)) != 0) : \ 199 (assert (!"BITSET_TEST_RANGE: bit range crosses word boundary"), 0)) 200#define BITSET_SET_RANGE_INSIDE_WORD(x, b, e) \ 201 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 202 ((x)[BITSET_BITWORD(b)] |= BITSET_RANGE(b, e)) : \ 203 (assert (!"BITSET_SET_RANGE_INSIDE_WORD: bit range crosses word boundary"), 0)) 204#define BITSET_CLEAR_RANGE_INSIDE_WORD(x, b, e) \ 205 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 206 ((x)[BITSET_BITWORD(b)] &= ~BITSET_RANGE(b, e)) : \ 207 (assert (!"BITSET_CLEAR_RANGE: bit range crosses word boundary"), 0)) 208 209static inline bool 210__bitset_test_range(const BITSET_WORD *r, unsigned start, unsigned end) 211{ 212 const unsigned size = end - start + 1; 213 const unsigned start_mod = start % BITSET_WORDBITS; 214 215 if (start_mod + size <= BITSET_WORDBITS) { 216 return BITSET_TEST_RANGE_INSIDE_WORD(r, start, end); 217 } else { 218 const unsigned first_size = BITSET_WORDBITS - start_mod; 219 220 return __bitset_test_range(r, start, start + first_size - 1) || 221 __bitset_test_range(r, start + first_size, end); 222 } 223} 224 225#define BITSET_TEST_RANGE(x, b, e) \ 226 __bitset_test_range(x, b, e) 227 228static inline void 229__bitset_set_range(BITSET_WORD *r, unsigned start, unsigned end) 230{ 231 const unsigned size = end - start + 1; 232 const unsigned start_mod = start % BITSET_WORDBITS; 233 234 if (start_mod + size <= BITSET_WORDBITS) { 235 BITSET_SET_RANGE_INSIDE_WORD(r, start, end); 236 } else { 237 const unsigned first_size = BITSET_WORDBITS - start_mod; 238 239 __bitset_set_range(r, start, start + first_size - 1); 240 __bitset_set_range(r, start + first_size, end); 241 } 242} 243 244#define BITSET_SET_RANGE(x, b, e) \ 245 __bitset_set_range(x, b, e) 246 247static inline void 248__bitclear_clear_range(BITSET_WORD *r, unsigned start, unsigned end) 249{ 250 const unsigned size = end - start + 1; 251 const unsigned start_mod = start % BITSET_WORDBITS; 252 253 if (start_mod + size <= BITSET_WORDBITS) { 254 BITSET_CLEAR_RANGE_INSIDE_WORD(r, start, end); 255 } else { 256 const unsigned first_size = BITSET_WORDBITS - start_mod; 257 258 __bitclear_clear_range(r, start, start + first_size - 1); 259 __bitclear_clear_range(r, start + first_size, end); 260 } 261} 262 263#define BITSET_CLEAR_RANGE(x, b, e) \ 264 __bitclear_clear_range(x, b, e) 265 266static inline unsigned 267__bitset_prefix_sum(const BITSET_WORD *x, unsigned b, unsigned n) 268{ 269 unsigned prefix = 0; 270 271 for (unsigned i = 0; i < n; i++) { 272 if ((i + 1) * BITSET_WORDBITS <= b) { 273 prefix += util_bitcount(x[i]); 274 } else { 275 prefix += util_bitcount(x[i] & BITFIELD_MASK(b - i * BITSET_WORDBITS)); 276 break; 277 } 278 } 279 return prefix; 280} 281 282/* Count set bits in the bitset (compute the size/cardinality of the bitset). 283 * This is a special case of prefix sum, but this convenience method is more 284 * natural when applicable. 285 */ 286 287static inline unsigned 288__bitset_count(const BITSET_WORD *x, unsigned n) 289{ 290 return __bitset_prefix_sum(x, ~0, n); 291} 292 293#define BITSET_PREFIX_SUM(x, b) \ 294 __bitset_prefix_sum(x, b, ARRAY_SIZE(x)) 295 296#define BITSET_COUNT(x) \ 297 __bitset_count(x, ARRAY_SIZE(x)) 298 299/* Get first bit set in a bitset. 300 */ 301static inline int 302__bitset_ffs(const BITSET_WORD *x, int n) 303{ 304 for (int i = 0; i < n; i++) { 305 if (x[i]) 306 return ffs(x[i]) + BITSET_WORDBITS * i; 307 } 308 309 return 0; 310} 311 312/* Get the last bit set in a bitset. 313 */ 314static inline int 315__bitset_last_bit(const BITSET_WORD *x, int n) 316{ 317 for (int i = n - 1; i >= 0; i--) { 318 if (x[i]) 319 return util_last_bit(x[i]) + BITSET_WORDBITS * i; 320 } 321 322 return 0; 323} 324 325#define BITSET_FFS(x) __bitset_ffs(x, ARRAY_SIZE(x)) 326#define BITSET_LAST_BIT(x) __bitset_last_bit(x, ARRAY_SIZE(x)) 327#define BITSET_LAST_BIT_SIZED(x, size) __bitset_last_bit(x, size) 328 329static inline unsigned 330__bitset_next_set(unsigned i, BITSET_WORD *tmp, 331 const BITSET_WORD *set, unsigned size) 332{ 333 unsigned bit, word; 334 335 /* NOTE: The initial conditions for this function are very specific. At 336 * the start of the loop, the tmp variable must be set to *set and the 337 * initial i value set to 0. This way, if there is a bit set in the first 338 * word, we ignore the i-value and just grab that bit (so 0 is ok, even 339 * though 0 may be returned). If the first word is 0, then the value of 340 * `word` will be 0 and we will go on to look at the second word. 341 */ 342 word = BITSET_BITWORD(i); 343 while (*tmp == 0) { 344 word++; 345 346 if (word >= BITSET_WORDS(size)) 347 return size; 348 349 *tmp = set[word]; 350 } 351 352 /* Find the next set bit in the non-zero word */ 353 bit = ffs(*tmp) - 1; 354 355 /* Unset the bit */ 356 *tmp &= ~(1ull << bit); 357 358 return word * BITSET_WORDBITS + bit; 359} 360 361/** 362 * Iterates over each set bit in a set 363 * 364 * @param __i iteration variable, bit number 365 * @param __set the bitset to iterate (will not be modified) 366 * @param __size number of bits in the set to consider 367 */ 368#define BITSET_FOREACH_SET(__i, __set, __size) \ 369 for (BITSET_WORD __tmp = (__size) == 0 ? 0 : *(__set), *__foo = &__tmp; __foo != NULL; __foo = NULL) \ 370 for (__i = 0; \ 371 (__i = __bitset_next_set(__i, &__tmp, __set, __size)) < __size;) 372 373static inline void 374__bitset_next_range(unsigned *start, unsigned *end, const BITSET_WORD *set, 375 unsigned size) 376{ 377 /* To find the next start, start searching from end. In the first iteration 378 * it will be at 0, in every subsequent iteration it will be at the first 379 * 0-bit after the range. 380 */ 381 unsigned word = BITSET_BITWORD(*end); 382 if (word >= BITSET_WORDS(size)) { 383 *start = *end = size; 384 return; 385 } 386 BITSET_WORD tmp = set[word] & ~(BITSET_BIT(*end) - 1); 387 while (!tmp) { 388 word++; 389 if (word >= BITSET_WORDS(size)) { 390 *start = *end = size; 391 return; 392 } 393 tmp = set[word]; 394 } 395 396 *start = word * BITSET_WORDBITS + ffs(tmp) - 1; 397 398 /* Now do the opposite to find end. Here we can start at start + 1, because 399 * we know that the bit at start is 1 and we're searching for the first 400 * 0-bit. 401 */ 402 word = BITSET_BITWORD(*start + 1); 403 if (word >= BITSET_WORDS(size)) { 404 *end = size; 405 return; 406 } 407 tmp = set[word] | (BITSET_BIT(*start + 1) - 1); 408 while (~tmp == 0) { 409 word++; 410 if (word >= BITSET_WORDS(size)) { 411 *end = size; 412 return; 413 } 414 tmp = set[word]; 415 } 416 417 /* Cap "end" at "size" in case there are extra bits past "size" set in the 418 * word. This is only necessary for "end" because we terminate the loop if 419 * "start" goes past "size". 420 */ 421 *end = MIN2(word * BITSET_WORDBITS + ffs(~tmp) - 1, size); 422} 423 424/** 425 * Iterates over each contiguous range of set bits in a set 426 * 427 * @param __start the first 1 bit of the current range 428 * @param __end the bit after the last 1 bit of the current range 429 * @param __set the bitset to iterate (will not be modified) 430 * @param __size number of bits in the set to consider 431 */ 432#define BITSET_FOREACH_RANGE(__start, __end, __set, __size) \ 433 for (__start = 0, __end = 0, \ 434 __bitset_next_range(&__start, &__end, __set, __size); \ 435 __start < __size; \ 436 __bitset_next_range(&__start, &__end, __set, __size)) 437 438 439#ifdef __cplusplus 440 441/** 442 * Simple C++ wrapper of a bitset type of static size, with value semantics 443 * and basic bitwise arithmetic operators. The operators defined below are 444 * expected to have the same semantics as the same operator applied to other 445 * fundamental integer types. T is the name of the struct to instantiate 446 * it as, and N is the number of bits in the bitset. 447 */ 448#define DECLARE_BITSET_T(T, N) struct T { \ 449 EXPLICIT_CONVERSION \ 450 operator bool() const \ 451 { \ 452 for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ 453 if (words[i]) \ 454 return true; \ 455 return false; \ 456 } \ 457 \ 458 T & \ 459 operator=(int x) \ 460 { \ 461 const T c = {{ (BITSET_WORD)x }}; \ 462 return *this = c; \ 463 } \ 464 \ 465 friend bool \ 466 operator==(const T &b, const T &c) \ 467 { \ 468 return BITSET_EQUAL(b.words, c.words); \ 469 } \ 470 \ 471 friend bool \ 472 operator!=(const T &b, const T &c) \ 473 { \ 474 return !(b == c); \ 475 } \ 476 \ 477 friend bool \ 478 operator==(const T &b, int x) \ 479 { \ 480 const T c = {{ (BITSET_WORD)x }}; \ 481 return b == c; \ 482 } \ 483 \ 484 friend bool \ 485 operator!=(const T &b, int x) \ 486 { \ 487 return !(b == x); \ 488 } \ 489 \ 490 friend T \ 491 operator~(const T &b) \ 492 { \ 493 T c; \ 494 for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ 495 c.words[i] = ~b.words[i]; \ 496 return c; \ 497 } \ 498 \ 499 T & \ 500 operator|=(const T &b) \ 501 { \ 502 for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ 503 words[i] |= b.words[i]; \ 504 return *this; \ 505 } \ 506 \ 507 friend T \ 508 operator|(const T &b, const T &c) \ 509 { \ 510 T d = b; \ 511 d |= c; \ 512 return d; \ 513 } \ 514 \ 515 T & \ 516 operator&=(const T &b) \ 517 { \ 518 for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ 519 words[i] &= b.words[i]; \ 520 return *this; \ 521 } \ 522 \ 523 friend T \ 524 operator&(const T &b, const T &c) \ 525 { \ 526 T d = b; \ 527 d &= c; \ 528 return d; \ 529 } \ 530 \ 531 bool \ 532 test(unsigned i) const \ 533 { \ 534 return BITSET_TEST(words, i); \ 535 } \ 536 \ 537 T & \ 538 set(unsigned i) \ 539 { \ 540 BITSET_SET(words, i); \ 541 return *this; \ 542 } \ 543 \ 544 T & \ 545 clear(unsigned i) \ 546 { \ 547 BITSET_CLEAR(words, i); \ 548 return *this; \ 549 } \ 550 \ 551 BITSET_WORD words[BITSET_WORDS(N)]; \ 552 } 553 554#endif 555 556#endif 557