src/share/vm/utilities/bitMap.cpp

Mon, 09 Mar 2009 13:28:46 -0700

author
xdono
date
Mon, 09 Mar 2009 13:28:46 -0700
changeset 1014
0fbdb4381b99
parent 777
37f87013dfd8
child 1244
6e2afda171db
permissions
-rw-r--r--

6814575: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 03/09
Reviewed-by: katleman, tbell, ohair

duke@435 1 /*
duke@435 2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 # include "incls/_precompiled.incl"
duke@435 26 # include "incls/_bitMap.cpp.incl"
duke@435 27
duke@435 28
ysr@777 29 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
ysr@777 30 _map(map), _size(size_in_bits)
ysr@777 31 {
ysr@777 32 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
duke@435 33 assert(size_in_bits >= 0, "just checking");
duke@435 34 }
duke@435 35
duke@435 36
ysr@777 37 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
ysr@777 38 _map(NULL), _size(0)
ysr@777 39 {
ysr@777 40 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
ysr@777 41 resize(size_in_bits, in_resource_area);
duke@435 42 }
duke@435 43
duke@435 44
ysr@777 45 void BitMap::verify_index(idx_t index) const {
ysr@777 46 assert(index < _size, "BitMap index out of bounds");
ysr@777 47 }
ysr@777 48
ysr@777 49 void BitMap::verify_range(idx_t beg_index, idx_t end_index) const {
ysr@777 50 #ifdef ASSERT
ysr@777 51 assert(beg_index <= end_index, "BitMap range error");
ysr@777 52 // Note that [0,0) and [size,size) are both valid ranges.
ysr@777 53 if (end_index != _size) verify_index(end_index);
ysr@777 54 #endif
ysr@777 55 }
ysr@777 56
ysr@777 57 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
duke@435 58 assert(size_in_bits >= 0, "just checking");
ysr@777 59 idx_t old_size_in_words = size_in_words();
ysr@777 60 bm_word_t* old_map = map();
ysr@777 61
duke@435 62 _size = size_in_bits;
ysr@777 63 idx_t new_size_in_words = size_in_words();
ysr@777 64 if (in_resource_area) {
ysr@777 65 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
ysr@777 66 } else {
ysr@777 67 if (old_map != NULL) FREE_C_HEAP_ARRAY(bm_word_t, _map);
ysr@777 68 _map = NEW_C_HEAP_ARRAY(bm_word_t, new_size_in_words);
ysr@777 69 }
ysr@777 70 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
ysr@777 71 MIN2(old_size_in_words, new_size_in_words));
duke@435 72 if (new_size_in_words > old_size_in_words) {
duke@435 73 clear_range_of_words(old_size_in_words, size_in_words());
duke@435 74 }
duke@435 75 }
duke@435 76
duke@435 77 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
duke@435 78 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 79 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 80 if (beg != end) {
ysr@777 81 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 82 *word_addr(beg) |= ~mask;
duke@435 83 }
duke@435 84 }
duke@435 85
duke@435 86 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
duke@435 87 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 88 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 89 if (beg != end) {
ysr@777 90 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 91 *word_addr(beg) &= mask;
duke@435 92 }
duke@435 93 }
duke@435 94
duke@435 95 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
duke@435 96 assert(value == 0 || value == 1, "0 for clear, 1 for set");
duke@435 97 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 98 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 99 if (beg != end) {
duke@435 100 intptr_t* pw = (intptr_t*)word_addr(beg);
duke@435 101 intptr_t w = *pw;
duke@435 102 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
duke@435 103 intptr_t nw = value ? (w | ~mr) : (w & mr);
duke@435 104 while (true) {
duke@435 105 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
duke@435 106 if (res == w) break;
duke@435 107 w = *pw;
duke@435 108 nw = value ? (w | ~mr) : (w & mr);
duke@435 109 }
duke@435 110 }
duke@435 111 }
duke@435 112
duke@435 113 void BitMap::set_range(idx_t beg, idx_t end) {
duke@435 114 verify_range(beg, end);
duke@435 115
duke@435 116 idx_t beg_full_word = word_index_round_up(beg);
duke@435 117 idx_t end_full_word = word_index(end);
duke@435 118
duke@435 119 if (beg_full_word < end_full_word) {
duke@435 120 // The range includes at least one full word.
duke@435 121 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 122 set_range_of_words(beg_full_word, end_full_word);
duke@435 123 set_range_within_word(bit_index(end_full_word), end);
duke@435 124 } else {
duke@435 125 // The range spans at most 2 partial words.
duke@435 126 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 127 set_range_within_word(beg, boundary);
duke@435 128 set_range_within_word(boundary, end);
duke@435 129 }
duke@435 130 }
duke@435 131
duke@435 132 void BitMap::clear_range(idx_t beg, idx_t end) {
duke@435 133 verify_range(beg, end);
duke@435 134
duke@435 135 idx_t beg_full_word = word_index_round_up(beg);
duke@435 136 idx_t end_full_word = word_index(end);
duke@435 137
duke@435 138 if (beg_full_word < end_full_word) {
duke@435 139 // The range includes at least one full word.
duke@435 140 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 141 clear_range_of_words(beg_full_word, end_full_word);
duke@435 142 clear_range_within_word(bit_index(end_full_word), end);
duke@435 143 } else {
duke@435 144 // The range spans at most 2 partial words.
duke@435 145 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 146 clear_range_within_word(beg, boundary);
duke@435 147 clear_range_within_word(boundary, end);
duke@435 148 }
duke@435 149 }
duke@435 150
duke@435 151 void BitMap::set_large_range(idx_t beg, idx_t end) {
duke@435 152 verify_range(beg, end);
duke@435 153
duke@435 154 idx_t beg_full_word = word_index_round_up(beg);
duke@435 155 idx_t end_full_word = word_index(end);
duke@435 156
duke@435 157 assert(end_full_word - beg_full_word >= 32,
duke@435 158 "the range must include at least 32 bytes");
duke@435 159
duke@435 160 // The range includes at least one full word.
duke@435 161 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 162 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 163 set_range_within_word(bit_index(end_full_word), end);
duke@435 164 }
duke@435 165
duke@435 166 void BitMap::clear_large_range(idx_t beg, idx_t end) {
duke@435 167 verify_range(beg, end);
duke@435 168
duke@435 169 idx_t beg_full_word = word_index_round_up(beg);
duke@435 170 idx_t end_full_word = word_index(end);
duke@435 171
duke@435 172 assert(end_full_word - beg_full_word >= 32,
duke@435 173 "the range must include at least 32 bytes");
duke@435 174
duke@435 175 // The range includes at least one full word.
duke@435 176 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 177 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 178 clear_range_within_word(bit_index(end_full_word), end);
duke@435 179 }
duke@435 180
ysr@777 181 void BitMap::mostly_disjoint_range_union(BitMap* from_bitmap,
ysr@777 182 idx_t from_start_index,
ysr@777 183 idx_t to_start_index,
ysr@777 184 size_t word_num) {
ysr@777 185 // Ensure that the parameters are correct.
ysr@777 186 // These shouldn't be that expensive to check, hence I left them as
ysr@777 187 // guarantees.
ysr@777 188 guarantee(from_bitmap->bit_in_word(from_start_index) == 0,
ysr@777 189 "it should be aligned on a word boundary");
ysr@777 190 guarantee(bit_in_word(to_start_index) == 0,
ysr@777 191 "it should be aligned on a word boundary");
ysr@777 192 guarantee(word_num >= 2, "word_num should be at least 2");
ysr@777 193
ysr@777 194 intptr_t* from = (intptr_t*) from_bitmap->word_addr(from_start_index);
ysr@777 195 intptr_t* to = (intptr_t*) word_addr(to_start_index);
ysr@777 196
ysr@777 197 if (*from != 0) {
ysr@777 198 // if it's 0, then there's no point in doing the CAS
ysr@777 199 while (true) {
ysr@777 200 intptr_t old_value = *to;
ysr@777 201 intptr_t new_value = old_value | *from;
ysr@777 202 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 203 if (res == old_value) break;
ysr@777 204 }
ysr@777 205 }
ysr@777 206 ++from;
ysr@777 207 ++to;
ysr@777 208
ysr@777 209 for (size_t i = 0; i < word_num - 2; ++i) {
ysr@777 210 if (*from != 0) {
ysr@777 211 // if it's 0, then there's no point in doing the CAS
ysr@777 212 assert(*to == 0, "nobody else should be writing here");
ysr@777 213 intptr_t new_value = *from;
ysr@777 214 *to = new_value;
ysr@777 215 }
ysr@777 216
ysr@777 217 ++from;
ysr@777 218 ++to;
ysr@777 219 }
ysr@777 220
ysr@777 221 if (*from != 0) {
ysr@777 222 // if it's 0, then there's no point in doing the CAS
ysr@777 223 while (true) {
ysr@777 224 intptr_t old_value = *to;
ysr@777 225 intptr_t new_value = old_value | *from;
ysr@777 226 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 227 if (res == old_value) break;
ysr@777 228 }
ysr@777 229 }
ysr@777 230
ysr@777 231 // the -1 is because we didn't advance them after the final CAS
ysr@777 232 assert(from ==
ysr@777 233 (intptr_t*) from_bitmap->word_addr(from_start_index) + word_num - 1,
ysr@777 234 "invariant");
ysr@777 235 assert(to == (intptr_t*) word_addr(to_start_index) + word_num - 1,
ysr@777 236 "invariant");
ysr@777 237 }
ysr@777 238
duke@435 239 void BitMap::at_put(idx_t offset, bool value) {
duke@435 240 if (value) {
duke@435 241 set_bit(offset);
duke@435 242 } else {
duke@435 243 clear_bit(offset);
duke@435 244 }
duke@435 245 }
duke@435 246
duke@435 247 // Return true to indicate that this thread changed
duke@435 248 // the bit, false to indicate that someone else did.
duke@435 249 // In either case, the requested bit is in the
duke@435 250 // requested state some time during the period that
duke@435 251 // this thread is executing this call. More importantly,
duke@435 252 // if no other thread is executing an action to
duke@435 253 // change the requested bit to a state other than
duke@435 254 // the one that this thread is trying to set it to,
duke@435 255 // then the the bit is in the expected state
duke@435 256 // at exit from this method. However, rather than
duke@435 257 // make such a strong assertion here, based on
duke@435 258 // assuming such constrained use (which though true
duke@435 259 // today, could change in the future to service some
duke@435 260 // funky parallel algorithm), we encourage callers
duke@435 261 // to do such verification, as and when appropriate.
duke@435 262 bool BitMap::par_at_put(idx_t bit, bool value) {
duke@435 263 return value ? par_set_bit(bit) : par_clear_bit(bit);
duke@435 264 }
duke@435 265
duke@435 266 void BitMap::at_put_grow(idx_t offset, bool value) {
duke@435 267 if (offset >= size()) {
duke@435 268 resize(2 * MAX2(size(), offset));
duke@435 269 }
duke@435 270 at_put(offset, value);
duke@435 271 }
duke@435 272
duke@435 273 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
duke@435 274 if (value) {
duke@435 275 set_range(start_offset, end_offset);
duke@435 276 } else {
duke@435 277 clear_range(start_offset, end_offset);
duke@435 278 }
duke@435 279 }
duke@435 280
duke@435 281 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
duke@435 282 verify_range(beg, end);
duke@435 283
duke@435 284 idx_t beg_full_word = word_index_round_up(beg);
duke@435 285 idx_t end_full_word = word_index(end);
duke@435 286
duke@435 287 if (beg_full_word < end_full_word) {
duke@435 288 // The range includes at least one full word.
duke@435 289 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 290 if (value) {
duke@435 291 set_range_of_words(beg_full_word, end_full_word);
duke@435 292 } else {
duke@435 293 clear_range_of_words(beg_full_word, end_full_word);
duke@435 294 }
duke@435 295 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 296 } else {
duke@435 297 // The range spans at most 2 partial words.
duke@435 298 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 299 par_put_range_within_word(beg, boundary, value);
duke@435 300 par_put_range_within_word(boundary, end, value);
duke@435 301 }
duke@435 302
duke@435 303 }
duke@435 304
duke@435 305 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 306 if (value) {
duke@435 307 set_large_range(beg, end);
duke@435 308 } else {
duke@435 309 clear_large_range(beg, end);
duke@435 310 }
duke@435 311 }
duke@435 312
duke@435 313 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 314 verify_range(beg, end);
duke@435 315
duke@435 316 idx_t beg_full_word = word_index_round_up(beg);
duke@435 317 idx_t end_full_word = word_index(end);
duke@435 318
duke@435 319 assert(end_full_word - beg_full_word >= 32,
duke@435 320 "the range must include at least 32 bytes");
duke@435 321
duke@435 322 // The range includes at least one full word.
duke@435 323 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 324 if (value) {
duke@435 325 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 326 } else {
duke@435 327 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 328 }
duke@435 329 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 330 }
duke@435 331
duke@435 332 bool BitMap::contains(const BitMap other) const {
duke@435 333 assert(size() == other.size(), "must have same size");
ysr@777 334 bm_word_t* dest_map = map();
ysr@777 335 bm_word_t* other_map = other.map();
duke@435 336 idx_t size = size_in_words();
duke@435 337 for (idx_t index = 0; index < size_in_words(); index++) {
ysr@777 338 bm_word_t word_union = dest_map[index] | other_map[index];
duke@435 339 // If this has more bits set than dest_map[index], then other is not a
duke@435 340 // subset.
duke@435 341 if (word_union != dest_map[index]) return false;
duke@435 342 }
duke@435 343 return true;
duke@435 344 }
duke@435 345
duke@435 346 bool BitMap::intersects(const BitMap other) const {
duke@435 347 assert(size() == other.size(), "must have same size");
ysr@777 348 bm_word_t* dest_map = map();
ysr@777 349 bm_word_t* other_map = other.map();
duke@435 350 idx_t size = size_in_words();
duke@435 351 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 352 if ((dest_map[index] & other_map[index]) != 0) return true;
duke@435 353 }
duke@435 354 // Otherwise, no intersection.
duke@435 355 return false;
duke@435 356 }
duke@435 357
duke@435 358 void BitMap::set_union(BitMap other) {
duke@435 359 assert(size() == other.size(), "must have same size");
ysr@777 360 bm_word_t* dest_map = map();
ysr@777 361 bm_word_t* other_map = other.map();
duke@435 362 idx_t size = size_in_words();
duke@435 363 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 364 dest_map[index] = dest_map[index] | other_map[index];
duke@435 365 }
duke@435 366 }
duke@435 367
duke@435 368
duke@435 369 void BitMap::set_difference(BitMap other) {
duke@435 370 assert(size() == other.size(), "must have same size");
ysr@777 371 bm_word_t* dest_map = map();
ysr@777 372 bm_word_t* other_map = other.map();
duke@435 373 idx_t size = size_in_words();
duke@435 374 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 375 dest_map[index] = dest_map[index] & ~(other_map[index]);
duke@435 376 }
duke@435 377 }
duke@435 378
duke@435 379
duke@435 380 void BitMap::set_intersection(BitMap other) {
duke@435 381 assert(size() == other.size(), "must have same size");
ysr@777 382 bm_word_t* dest_map = map();
ysr@777 383 bm_word_t* other_map = other.map();
duke@435 384 idx_t size = size_in_words();
duke@435 385 for (idx_t index = 0; index < size; index++) {
duke@435 386 dest_map[index] = dest_map[index] & other_map[index];
duke@435 387 }
duke@435 388 }
duke@435 389
duke@435 390
ysr@777 391 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
ysr@777 392 assert(other.size() >= offset, "offset not in range");
ysr@777 393 assert(other.size() - offset >= size(), "other not large enough");
ysr@777 394 // XXX Ideally, we would remove this restriction.
ysr@777 395 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
ysr@777 396 "Only handle aligned cases so far.");
ysr@777 397 bm_word_t* dest_map = map();
ysr@777 398 bm_word_t* other_map = other.map();
ysr@777 399 idx_t offset_word_ind = word_index(offset);
ysr@777 400 idx_t size = size_in_words();
ysr@777 401 for (idx_t index = 0; index < size; index++) {
ysr@777 402 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
ysr@777 403 }
ysr@777 404 }
ysr@777 405
duke@435 406 bool BitMap::set_union_with_result(BitMap other) {
duke@435 407 assert(size() == other.size(), "must have same size");
duke@435 408 bool changed = false;
ysr@777 409 bm_word_t* dest_map = map();
ysr@777 410 bm_word_t* other_map = other.map();
duke@435 411 idx_t size = size_in_words();
duke@435 412 for (idx_t index = 0; index < size; index++) {
duke@435 413 idx_t temp = map(index) | other_map[index];
duke@435 414 changed = changed || (temp != map(index));
duke@435 415 map()[index] = temp;
duke@435 416 }
duke@435 417 return changed;
duke@435 418 }
duke@435 419
duke@435 420
duke@435 421 bool BitMap::set_difference_with_result(BitMap other) {
duke@435 422 assert(size() == other.size(), "must have same size");
duke@435 423 bool changed = false;
ysr@777 424 bm_word_t* dest_map = map();
ysr@777 425 bm_word_t* other_map = other.map();
duke@435 426 idx_t size = size_in_words();
duke@435 427 for (idx_t index = 0; index < size; index++) {
ysr@777 428 bm_word_t temp = dest_map[index] & ~(other_map[index]);
duke@435 429 changed = changed || (temp != dest_map[index]);
duke@435 430 dest_map[index] = temp;
duke@435 431 }
duke@435 432 return changed;
duke@435 433 }
duke@435 434
duke@435 435
duke@435 436 bool BitMap::set_intersection_with_result(BitMap other) {
duke@435 437 assert(size() == other.size(), "must have same size");
duke@435 438 bool changed = false;
ysr@777 439 bm_word_t* dest_map = map();
ysr@777 440 bm_word_t* other_map = other.map();
duke@435 441 idx_t size = size_in_words();
duke@435 442 for (idx_t index = 0; index < size; index++) {
ysr@777 443 bm_word_t orig = dest_map[index];
ysr@777 444 bm_word_t temp = orig & other_map[index];
duke@435 445 changed = changed || (temp != orig);
duke@435 446 dest_map[index] = temp;
duke@435 447 }
duke@435 448 return changed;
duke@435 449 }
duke@435 450
duke@435 451
duke@435 452 void BitMap::set_from(BitMap other) {
duke@435 453 assert(size() == other.size(), "must have same size");
ysr@777 454 bm_word_t* dest_map = map();
ysr@777 455 bm_word_t* other_map = other.map();
duke@435 456 idx_t size = size_in_words();
duke@435 457 for (idx_t index = 0; index < size; index++) {
duke@435 458 dest_map[index] = other_map[index];
duke@435 459 }
duke@435 460 }
duke@435 461
duke@435 462
duke@435 463 bool BitMap::is_same(BitMap other) {
duke@435 464 assert(size() == other.size(), "must have same size");
ysr@777 465 bm_word_t* dest_map = map();
ysr@777 466 bm_word_t* other_map = other.map();
duke@435 467 idx_t size = size_in_words();
duke@435 468 for (idx_t index = 0; index < size; index++) {
duke@435 469 if (dest_map[index] != other_map[index]) return false;
duke@435 470 }
duke@435 471 return true;
duke@435 472 }
duke@435 473
duke@435 474 bool BitMap::is_full() const {
ysr@777 475 bm_word_t* word = map();
duke@435 476 idx_t rest = size();
duke@435 477 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 478 if (*word != (bm_word_t) AllBits) return false;
duke@435 479 word++;
duke@435 480 }
ysr@777 481 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
duke@435 482 }
duke@435 483
duke@435 484
duke@435 485 bool BitMap::is_empty() const {
ysr@777 486 bm_word_t* word = map();
duke@435 487 idx_t rest = size();
duke@435 488 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 489 if (*word != (bm_word_t) NoBits) return false;
duke@435 490 word++;
duke@435 491 }
ysr@777 492 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
duke@435 493 }
duke@435 494
duke@435 495 void BitMap::clear_large() {
duke@435 496 clear_large_range_of_words(0, size_in_words());
duke@435 497 }
duke@435 498
duke@435 499 // Note that if the closure itself modifies the bitmap
duke@435 500 // then modifications in and to the left of the _bit_ being
duke@435 501 // currently sampled will not be seen. Note also that the
duke@435 502 // interval [leftOffset, rightOffset) is right open.
ysr@777 503 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
duke@435 504 verify_range(leftOffset, rightOffset);
duke@435 505
duke@435 506 idx_t startIndex = word_index(leftOffset);
duke@435 507 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
duke@435 508 for (idx_t index = startIndex, offset = leftOffset;
duke@435 509 offset < rightOffset && index < endIndex;
duke@435 510 offset = (++index) << LogBitsPerWord) {
duke@435 511 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
ysr@777 512 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
duke@435 513 if (rest & 1) {
ysr@777 514 if (!blk->do_bit(offset)) return false;
duke@435 515 // resample at each closure application
duke@435 516 // (see, for instance, CMS bug 4525989)
duke@435 517 rest = map(index) >> (offset & (BitsPerWord -1));
duke@435 518 }
duke@435 519 rest = rest >> 1;
duke@435 520 }
duke@435 521 }
ysr@777 522 return true;
duke@435 523 }
duke@435 524
ysr@777 525 BitMap::idx_t* BitMap::_pop_count_table = NULL;
duke@435 526
ysr@777 527 void BitMap::init_pop_count_table() {
ysr@777 528 if (_pop_count_table == NULL) {
ysr@777 529 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256);
ysr@777 530 for (uint i = 0; i < 256; i++) {
ysr@777 531 table[i] = num_set_bits(i);
ysr@777 532 }
duke@435 533
ysr@777 534 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table,
ysr@777 535 (intptr_t*) &_pop_count_table,
ysr@777 536 (intptr_t) NULL_WORD);
ysr@777 537 if (res != NULL_WORD) {
ysr@777 538 guarantee( _pop_count_table == (void*) res, "invariant" );
ysr@777 539 FREE_C_HEAP_ARRAY(bm_word_t, table);
duke@435 540 }
duke@435 541 }
duke@435 542 }
duke@435 543
ysr@777 544 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
ysr@777 545 idx_t bits = 0;
duke@435 546
ysr@777 547 while (w != 0) {
ysr@777 548 while ((w & 1) == 0) {
ysr@777 549 w >>= 1;
ysr@777 550 }
ysr@777 551 bits++;
ysr@777 552 w >>= 1;
duke@435 553 }
ysr@777 554 return bits;
ysr@777 555 }
duke@435 556
ysr@777 557 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
ysr@777 558 assert(_pop_count_table != NULL, "precondition");
ysr@777 559 return _pop_count_table[c];
ysr@777 560 }
duke@435 561
ysr@777 562 BitMap::idx_t BitMap::count_one_bits() const {
ysr@777 563 init_pop_count_table(); // If necessary.
ysr@777 564 idx_t sum = 0;
ysr@777 565 typedef unsigned char uchar;
ysr@777 566 for (idx_t i = 0; i < size_in_words(); i++) {
ysr@777 567 bm_word_t w = map()[i];
ysr@777 568 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
ysr@777 569 sum += num_set_bits_from_table(uchar(w & 255));
ysr@777 570 w >>= 8;
duke@435 571 }
duke@435 572 }
ysr@777 573 return sum;
duke@435 574 }
duke@435 575
ysr@777 576
duke@435 577 #ifndef PRODUCT
duke@435 578
duke@435 579 void BitMap::print_on(outputStream* st) const {
duke@435 580 tty->print("Bitmap(%d):", size());
duke@435 581 for (idx_t index = 0; index < size(); index++) {
duke@435 582 tty->print("%c", at(index) ? '1' : '0');
duke@435 583 }
duke@435 584 tty->cr();
duke@435 585 }
duke@435 586
duke@435 587 #endif
duke@435 588
duke@435 589
ysr@777 590 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
duke@435 591 : _bits_per_slot(bits_per_slot)
duke@435 592 , _map(map, size_in_slots * bits_per_slot)
duke@435 593 {
duke@435 594 }
duke@435 595
duke@435 596
duke@435 597 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
duke@435 598 : _bits_per_slot(bits_per_slot)
duke@435 599 , _map(size_in_slots * bits_per_slot)
duke@435 600 {
duke@435 601 }

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