src/share/vm/utilities/bitMap.cpp

Sun, 25 Sep 2011 16:03:29 -0700

author
never
date
Sun, 25 Sep 2011 16:03:29 -0700
changeset 3156
f08d439fab8c
parent 2314
f95d63e2154a
child 3691
2a0172480595
permissions
-rw-r--r--

7089790: integrate bsd-port changes
Reviewed-by: kvn, twisti, jrose
Contributed-by: Kurt Miller <kurt@intricatesoftware.com>, Greg Lewis <glewis@eyesbeyond.com>, Jung-uk Kim <jkim@freebsd.org>, Christos Zoulas <christos@zoulas.com>, Landon Fuller <landonf@plausible.coop>, The FreeBSD Foundation <board@freebsdfoundation.org>, Michael Franz <mvfranz@gmail.com>, Roger Hoover <rhoover@apple.com>, Alexander Strange <astrange@apple.com>

duke@435 1 /*
stefank@2314 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. 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 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "memory/allocation.inline.hpp"
stefank@2314 27 #include "utilities/bitMap.inline.hpp"
stefank@2314 28 #include "utilities/copy.hpp"
stefank@2314 29 #ifdef TARGET_OS_FAMILY_linux
stefank@2314 30 # include "os_linux.inline.hpp"
stefank@2314 31 #endif
stefank@2314 32 #ifdef TARGET_OS_FAMILY_solaris
stefank@2314 33 # include "os_solaris.inline.hpp"
stefank@2314 34 #endif
stefank@2314 35 #ifdef TARGET_OS_FAMILY_windows
stefank@2314 36 # include "os_windows.inline.hpp"
stefank@2314 37 #endif
never@3156 38 #ifdef TARGET_OS_FAMILY_bsd
never@3156 39 # include "os_bsd.inline.hpp"
never@3156 40 #endif
duke@435 41
duke@435 42
ysr@777 43 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
ysr@777 44 _map(map), _size(size_in_bits)
ysr@777 45 {
ysr@777 46 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
duke@435 47 assert(size_in_bits >= 0, "just checking");
duke@435 48 }
duke@435 49
duke@435 50
ysr@777 51 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
ysr@777 52 _map(NULL), _size(0)
ysr@777 53 {
ysr@777 54 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
ysr@777 55 resize(size_in_bits, in_resource_area);
duke@435 56 }
duke@435 57
ysr@777 58 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
duke@435 59 assert(size_in_bits >= 0, "just checking");
ysr@777 60 idx_t old_size_in_words = size_in_words();
ysr@777 61 bm_word_t* old_map = map();
ysr@777 62
duke@435 63 _size = size_in_bits;
ysr@777 64 idx_t new_size_in_words = size_in_words();
ysr@777 65 if (in_resource_area) {
ysr@777 66 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
ysr@777 67 } else {
ysr@777 68 if (old_map != NULL) FREE_C_HEAP_ARRAY(bm_word_t, _map);
ysr@777 69 _map = NEW_C_HEAP_ARRAY(bm_word_t, new_size_in_words);
ysr@777 70 }
ysr@777 71 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
ysr@777 72 MIN2(old_size_in_words, new_size_in_words));
duke@435 73 if (new_size_in_words > old_size_in_words) {
duke@435 74 clear_range_of_words(old_size_in_words, size_in_words());
duke@435 75 }
duke@435 76 }
duke@435 77
duke@435 78 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
duke@435 79 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 80 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 81 if (beg != end) {
ysr@777 82 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 83 *word_addr(beg) |= ~mask;
duke@435 84 }
duke@435 85 }
duke@435 86
duke@435 87 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
duke@435 88 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 89 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 90 if (beg != end) {
ysr@777 91 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 92 *word_addr(beg) &= mask;
duke@435 93 }
duke@435 94 }
duke@435 95
duke@435 96 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
duke@435 97 assert(value == 0 || value == 1, "0 for clear, 1 for set");
duke@435 98 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 99 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 100 if (beg != end) {
duke@435 101 intptr_t* pw = (intptr_t*)word_addr(beg);
duke@435 102 intptr_t w = *pw;
duke@435 103 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
duke@435 104 intptr_t nw = value ? (w | ~mr) : (w & mr);
duke@435 105 while (true) {
duke@435 106 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
duke@435 107 if (res == w) break;
duke@435 108 w = *pw;
duke@435 109 nw = value ? (w | ~mr) : (w & mr);
duke@435 110 }
duke@435 111 }
duke@435 112 }
duke@435 113
duke@435 114 void BitMap::set_range(idx_t beg, idx_t end) {
duke@435 115 verify_range(beg, end);
duke@435 116
duke@435 117 idx_t beg_full_word = word_index_round_up(beg);
duke@435 118 idx_t end_full_word = word_index(end);
duke@435 119
duke@435 120 if (beg_full_word < end_full_word) {
duke@435 121 // The range includes at least one full word.
duke@435 122 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 123 set_range_of_words(beg_full_word, end_full_word);
duke@435 124 set_range_within_word(bit_index(end_full_word), end);
duke@435 125 } else {
duke@435 126 // The range spans at most 2 partial words.
duke@435 127 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 128 set_range_within_word(beg, boundary);
duke@435 129 set_range_within_word(boundary, end);
duke@435 130 }
duke@435 131 }
duke@435 132
duke@435 133 void BitMap::clear_range(idx_t beg, idx_t end) {
duke@435 134 verify_range(beg, end);
duke@435 135
duke@435 136 idx_t beg_full_word = word_index_round_up(beg);
duke@435 137 idx_t end_full_word = word_index(end);
duke@435 138
duke@435 139 if (beg_full_word < end_full_word) {
duke@435 140 // The range includes at least one full word.
duke@435 141 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 142 clear_range_of_words(beg_full_word, end_full_word);
duke@435 143 clear_range_within_word(bit_index(end_full_word), end);
duke@435 144 } else {
duke@435 145 // The range spans at most 2 partial words.
duke@435 146 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 147 clear_range_within_word(beg, boundary);
duke@435 148 clear_range_within_word(boundary, end);
duke@435 149 }
duke@435 150 }
duke@435 151
duke@435 152 void BitMap::set_large_range(idx_t beg, idx_t end) {
duke@435 153 verify_range(beg, end);
duke@435 154
duke@435 155 idx_t beg_full_word = word_index_round_up(beg);
duke@435 156 idx_t end_full_word = word_index(end);
duke@435 157
duke@435 158 assert(end_full_word - beg_full_word >= 32,
duke@435 159 "the range must include at least 32 bytes");
duke@435 160
duke@435 161 // The range includes at least one full word.
duke@435 162 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 163 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 164 set_range_within_word(bit_index(end_full_word), end);
duke@435 165 }
duke@435 166
duke@435 167 void BitMap::clear_large_range(idx_t beg, idx_t end) {
duke@435 168 verify_range(beg, end);
duke@435 169
duke@435 170 idx_t beg_full_word = word_index_round_up(beg);
duke@435 171 idx_t end_full_word = word_index(end);
duke@435 172
duke@435 173 assert(end_full_word - beg_full_word >= 32,
duke@435 174 "the range must include at least 32 bytes");
duke@435 175
duke@435 176 // The range includes at least one full word.
duke@435 177 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 178 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 179 clear_range_within_word(bit_index(end_full_word), end);
duke@435 180 }
duke@435 181
ysr@777 182 void BitMap::mostly_disjoint_range_union(BitMap* from_bitmap,
ysr@777 183 idx_t from_start_index,
ysr@777 184 idx_t to_start_index,
ysr@777 185 size_t word_num) {
ysr@777 186 // Ensure that the parameters are correct.
ysr@777 187 // These shouldn't be that expensive to check, hence I left them as
ysr@777 188 // guarantees.
ysr@777 189 guarantee(from_bitmap->bit_in_word(from_start_index) == 0,
ysr@777 190 "it should be aligned on a word boundary");
ysr@777 191 guarantee(bit_in_word(to_start_index) == 0,
ysr@777 192 "it should be aligned on a word boundary");
ysr@777 193 guarantee(word_num >= 2, "word_num should be at least 2");
ysr@777 194
ysr@777 195 intptr_t* from = (intptr_t*) from_bitmap->word_addr(from_start_index);
ysr@777 196 intptr_t* to = (intptr_t*) word_addr(to_start_index);
ysr@777 197
ysr@777 198 if (*from != 0) {
ysr@777 199 // if it's 0, then there's no point in doing the CAS
ysr@777 200 while (true) {
ysr@777 201 intptr_t old_value = *to;
ysr@777 202 intptr_t new_value = old_value | *from;
ysr@777 203 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 204 if (res == old_value) break;
ysr@777 205 }
ysr@777 206 }
ysr@777 207 ++from;
ysr@777 208 ++to;
ysr@777 209
ysr@777 210 for (size_t i = 0; i < word_num - 2; ++i) {
ysr@777 211 if (*from != 0) {
ysr@777 212 // if it's 0, then there's no point in doing the CAS
ysr@777 213 assert(*to == 0, "nobody else should be writing here");
ysr@777 214 intptr_t new_value = *from;
ysr@777 215 *to = new_value;
ysr@777 216 }
ysr@777 217
ysr@777 218 ++from;
ysr@777 219 ++to;
ysr@777 220 }
ysr@777 221
ysr@777 222 if (*from != 0) {
ysr@777 223 // if it's 0, then there's no point in doing the CAS
ysr@777 224 while (true) {
ysr@777 225 intptr_t old_value = *to;
ysr@777 226 intptr_t new_value = old_value | *from;
ysr@777 227 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 228 if (res == old_value) break;
ysr@777 229 }
ysr@777 230 }
ysr@777 231
ysr@777 232 // the -1 is because we didn't advance them after the final CAS
ysr@777 233 assert(from ==
ysr@777 234 (intptr_t*) from_bitmap->word_addr(from_start_index) + word_num - 1,
ysr@777 235 "invariant");
ysr@777 236 assert(to == (intptr_t*) word_addr(to_start_index) + word_num - 1,
ysr@777 237 "invariant");
ysr@777 238 }
ysr@777 239
duke@435 240 void BitMap::at_put(idx_t offset, bool value) {
duke@435 241 if (value) {
duke@435 242 set_bit(offset);
duke@435 243 } else {
duke@435 244 clear_bit(offset);
duke@435 245 }
duke@435 246 }
duke@435 247
duke@435 248 // Return true to indicate that this thread changed
duke@435 249 // the bit, false to indicate that someone else did.
duke@435 250 // In either case, the requested bit is in the
duke@435 251 // requested state some time during the period that
duke@435 252 // this thread is executing this call. More importantly,
duke@435 253 // if no other thread is executing an action to
duke@435 254 // change the requested bit to a state other than
duke@435 255 // the one that this thread is trying to set it to,
duke@435 256 // then the the bit is in the expected state
duke@435 257 // at exit from this method. However, rather than
duke@435 258 // make such a strong assertion here, based on
duke@435 259 // assuming such constrained use (which though true
duke@435 260 // today, could change in the future to service some
duke@435 261 // funky parallel algorithm), we encourage callers
duke@435 262 // to do such verification, as and when appropriate.
duke@435 263 bool BitMap::par_at_put(idx_t bit, bool value) {
duke@435 264 return value ? par_set_bit(bit) : par_clear_bit(bit);
duke@435 265 }
duke@435 266
duke@435 267 void BitMap::at_put_grow(idx_t offset, bool value) {
duke@435 268 if (offset >= size()) {
duke@435 269 resize(2 * MAX2(size(), offset));
duke@435 270 }
duke@435 271 at_put(offset, value);
duke@435 272 }
duke@435 273
duke@435 274 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
duke@435 275 if (value) {
duke@435 276 set_range(start_offset, end_offset);
duke@435 277 } else {
duke@435 278 clear_range(start_offset, end_offset);
duke@435 279 }
duke@435 280 }
duke@435 281
duke@435 282 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
duke@435 283 verify_range(beg, end);
duke@435 284
duke@435 285 idx_t beg_full_word = word_index_round_up(beg);
duke@435 286 idx_t end_full_word = word_index(end);
duke@435 287
duke@435 288 if (beg_full_word < end_full_word) {
duke@435 289 // The range includes at least one full word.
duke@435 290 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 291 if (value) {
duke@435 292 set_range_of_words(beg_full_word, end_full_word);
duke@435 293 } else {
duke@435 294 clear_range_of_words(beg_full_word, end_full_word);
duke@435 295 }
duke@435 296 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 297 } else {
duke@435 298 // The range spans at most 2 partial words.
duke@435 299 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 300 par_put_range_within_word(beg, boundary, value);
duke@435 301 par_put_range_within_word(boundary, end, value);
duke@435 302 }
duke@435 303
duke@435 304 }
duke@435 305
duke@435 306 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 307 if (value) {
duke@435 308 set_large_range(beg, end);
duke@435 309 } else {
duke@435 310 clear_large_range(beg, end);
duke@435 311 }
duke@435 312 }
duke@435 313
duke@435 314 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 315 verify_range(beg, end);
duke@435 316
duke@435 317 idx_t beg_full_word = word_index_round_up(beg);
duke@435 318 idx_t end_full_word = word_index(end);
duke@435 319
duke@435 320 assert(end_full_word - beg_full_word >= 32,
duke@435 321 "the range must include at least 32 bytes");
duke@435 322
duke@435 323 // The range includes at least one full word.
duke@435 324 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 325 if (value) {
duke@435 326 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 327 } else {
duke@435 328 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 329 }
duke@435 330 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 331 }
duke@435 332
duke@435 333 bool BitMap::contains(const BitMap other) const {
duke@435 334 assert(size() == other.size(), "must have same size");
ysr@777 335 bm_word_t* dest_map = map();
ysr@777 336 bm_word_t* other_map = other.map();
duke@435 337 idx_t size = size_in_words();
duke@435 338 for (idx_t index = 0; index < size_in_words(); index++) {
ysr@777 339 bm_word_t word_union = dest_map[index] | other_map[index];
duke@435 340 // If this has more bits set than dest_map[index], then other is not a
duke@435 341 // subset.
duke@435 342 if (word_union != dest_map[index]) return false;
duke@435 343 }
duke@435 344 return true;
duke@435 345 }
duke@435 346
duke@435 347 bool BitMap::intersects(const BitMap other) const {
duke@435 348 assert(size() == other.size(), "must have same size");
ysr@777 349 bm_word_t* dest_map = map();
ysr@777 350 bm_word_t* other_map = other.map();
duke@435 351 idx_t size = size_in_words();
duke@435 352 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 353 if ((dest_map[index] & other_map[index]) != 0) return true;
duke@435 354 }
duke@435 355 // Otherwise, no intersection.
duke@435 356 return false;
duke@435 357 }
duke@435 358
duke@435 359 void BitMap::set_union(BitMap other) {
duke@435 360 assert(size() == other.size(), "must have same size");
ysr@777 361 bm_word_t* dest_map = map();
ysr@777 362 bm_word_t* other_map = other.map();
duke@435 363 idx_t size = size_in_words();
duke@435 364 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 365 dest_map[index] = dest_map[index] | other_map[index];
duke@435 366 }
duke@435 367 }
duke@435 368
duke@435 369
duke@435 370 void BitMap::set_difference(BitMap other) {
duke@435 371 assert(size() == other.size(), "must have same size");
ysr@777 372 bm_word_t* dest_map = map();
ysr@777 373 bm_word_t* other_map = other.map();
duke@435 374 idx_t size = size_in_words();
duke@435 375 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 376 dest_map[index] = dest_map[index] & ~(other_map[index]);
duke@435 377 }
duke@435 378 }
duke@435 379
duke@435 380
duke@435 381 void BitMap::set_intersection(BitMap other) {
duke@435 382 assert(size() == other.size(), "must have same size");
ysr@777 383 bm_word_t* dest_map = map();
ysr@777 384 bm_word_t* other_map = other.map();
duke@435 385 idx_t size = size_in_words();
duke@435 386 for (idx_t index = 0; index < size; index++) {
duke@435 387 dest_map[index] = dest_map[index] & other_map[index];
duke@435 388 }
duke@435 389 }
duke@435 390
duke@435 391
ysr@777 392 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
ysr@777 393 assert(other.size() >= offset, "offset not in range");
ysr@777 394 assert(other.size() - offset >= size(), "other not large enough");
ysr@777 395 // XXX Ideally, we would remove this restriction.
ysr@777 396 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
ysr@777 397 "Only handle aligned cases so far.");
ysr@777 398 bm_word_t* dest_map = map();
ysr@777 399 bm_word_t* other_map = other.map();
ysr@777 400 idx_t offset_word_ind = word_index(offset);
ysr@777 401 idx_t size = size_in_words();
ysr@777 402 for (idx_t index = 0; index < size; index++) {
ysr@777 403 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
ysr@777 404 }
ysr@777 405 }
ysr@777 406
duke@435 407 bool BitMap::set_union_with_result(BitMap other) {
duke@435 408 assert(size() == other.size(), "must have same size");
duke@435 409 bool changed = false;
ysr@777 410 bm_word_t* dest_map = map();
ysr@777 411 bm_word_t* other_map = other.map();
duke@435 412 idx_t size = size_in_words();
duke@435 413 for (idx_t index = 0; index < size; index++) {
duke@435 414 idx_t temp = map(index) | other_map[index];
duke@435 415 changed = changed || (temp != map(index));
duke@435 416 map()[index] = temp;
duke@435 417 }
duke@435 418 return changed;
duke@435 419 }
duke@435 420
duke@435 421
duke@435 422 bool BitMap::set_difference_with_result(BitMap other) {
duke@435 423 assert(size() == other.size(), "must have same size");
duke@435 424 bool changed = false;
ysr@777 425 bm_word_t* dest_map = map();
ysr@777 426 bm_word_t* other_map = other.map();
duke@435 427 idx_t size = size_in_words();
duke@435 428 for (idx_t index = 0; index < size; index++) {
ysr@777 429 bm_word_t temp = dest_map[index] & ~(other_map[index]);
duke@435 430 changed = changed || (temp != dest_map[index]);
duke@435 431 dest_map[index] = temp;
duke@435 432 }
duke@435 433 return changed;
duke@435 434 }
duke@435 435
duke@435 436
duke@435 437 bool BitMap::set_intersection_with_result(BitMap other) {
duke@435 438 assert(size() == other.size(), "must have same size");
duke@435 439 bool changed = false;
ysr@777 440 bm_word_t* dest_map = map();
ysr@777 441 bm_word_t* other_map = other.map();
duke@435 442 idx_t size = size_in_words();
duke@435 443 for (idx_t index = 0; index < size; index++) {
ysr@777 444 bm_word_t orig = dest_map[index];
ysr@777 445 bm_word_t temp = orig & other_map[index];
duke@435 446 changed = changed || (temp != orig);
duke@435 447 dest_map[index] = temp;
duke@435 448 }
duke@435 449 return changed;
duke@435 450 }
duke@435 451
duke@435 452
duke@435 453 void BitMap::set_from(BitMap other) {
duke@435 454 assert(size() == other.size(), "must have same size");
ysr@777 455 bm_word_t* dest_map = map();
ysr@777 456 bm_word_t* other_map = other.map();
duke@435 457 idx_t size = size_in_words();
duke@435 458 for (idx_t index = 0; index < size; index++) {
duke@435 459 dest_map[index] = other_map[index];
duke@435 460 }
duke@435 461 }
duke@435 462
duke@435 463
duke@435 464 bool BitMap::is_same(BitMap other) {
duke@435 465 assert(size() == other.size(), "must have same size");
ysr@777 466 bm_word_t* dest_map = map();
ysr@777 467 bm_word_t* other_map = other.map();
duke@435 468 idx_t size = size_in_words();
duke@435 469 for (idx_t index = 0; index < size; index++) {
duke@435 470 if (dest_map[index] != other_map[index]) return false;
duke@435 471 }
duke@435 472 return true;
duke@435 473 }
duke@435 474
duke@435 475 bool BitMap::is_full() const {
ysr@777 476 bm_word_t* word = map();
duke@435 477 idx_t rest = size();
duke@435 478 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 479 if (*word != (bm_word_t) AllBits) return false;
duke@435 480 word++;
duke@435 481 }
ysr@777 482 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
duke@435 483 }
duke@435 484
duke@435 485
duke@435 486 bool BitMap::is_empty() const {
ysr@777 487 bm_word_t* word = map();
duke@435 488 idx_t rest = size();
duke@435 489 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 490 if (*word != (bm_word_t) NoBits) return false;
duke@435 491 word++;
duke@435 492 }
ysr@777 493 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
duke@435 494 }
duke@435 495
duke@435 496 void BitMap::clear_large() {
duke@435 497 clear_large_range_of_words(0, size_in_words());
duke@435 498 }
duke@435 499
duke@435 500 // Note that if the closure itself modifies the bitmap
duke@435 501 // then modifications in and to the left of the _bit_ being
duke@435 502 // currently sampled will not be seen. Note also that the
duke@435 503 // interval [leftOffset, rightOffset) is right open.
ysr@777 504 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
duke@435 505 verify_range(leftOffset, rightOffset);
duke@435 506
duke@435 507 idx_t startIndex = word_index(leftOffset);
duke@435 508 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
duke@435 509 for (idx_t index = startIndex, offset = leftOffset;
duke@435 510 offset < rightOffset && index < endIndex;
duke@435 511 offset = (++index) << LogBitsPerWord) {
duke@435 512 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
ysr@777 513 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
duke@435 514 if (rest & 1) {
ysr@777 515 if (!blk->do_bit(offset)) return false;
duke@435 516 // resample at each closure application
duke@435 517 // (see, for instance, CMS bug 4525989)
duke@435 518 rest = map(index) >> (offset & (BitsPerWord -1));
duke@435 519 }
duke@435 520 rest = rest >> 1;
duke@435 521 }
duke@435 522 }
ysr@777 523 return true;
duke@435 524 }
duke@435 525
ysr@777 526 BitMap::idx_t* BitMap::_pop_count_table = NULL;
duke@435 527
ysr@777 528 void BitMap::init_pop_count_table() {
ysr@777 529 if (_pop_count_table == NULL) {
ysr@777 530 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256);
ysr@777 531 for (uint i = 0; i < 256; i++) {
ysr@777 532 table[i] = num_set_bits(i);
ysr@777 533 }
duke@435 534
ysr@777 535 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table,
ysr@777 536 (intptr_t*) &_pop_count_table,
ysr@777 537 (intptr_t) NULL_WORD);
ysr@777 538 if (res != NULL_WORD) {
ysr@777 539 guarantee( _pop_count_table == (void*) res, "invariant" );
ysr@777 540 FREE_C_HEAP_ARRAY(bm_word_t, table);
duke@435 541 }
duke@435 542 }
duke@435 543 }
duke@435 544
ysr@777 545 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
ysr@777 546 idx_t bits = 0;
duke@435 547
ysr@777 548 while (w != 0) {
ysr@777 549 while ((w & 1) == 0) {
ysr@777 550 w >>= 1;
ysr@777 551 }
ysr@777 552 bits++;
ysr@777 553 w >>= 1;
duke@435 554 }
ysr@777 555 return bits;
ysr@777 556 }
duke@435 557
ysr@777 558 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
ysr@777 559 assert(_pop_count_table != NULL, "precondition");
ysr@777 560 return _pop_count_table[c];
ysr@777 561 }
duke@435 562
ysr@777 563 BitMap::idx_t BitMap::count_one_bits() const {
ysr@777 564 init_pop_count_table(); // If necessary.
ysr@777 565 idx_t sum = 0;
ysr@777 566 typedef unsigned char uchar;
ysr@777 567 for (idx_t i = 0; i < size_in_words(); i++) {
ysr@777 568 bm_word_t w = map()[i];
ysr@777 569 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
ysr@777 570 sum += num_set_bits_from_table(uchar(w & 255));
ysr@777 571 w >>= 8;
duke@435 572 }
duke@435 573 }
ysr@777 574 return sum;
duke@435 575 }
duke@435 576
ysr@777 577
duke@435 578 #ifndef PRODUCT
duke@435 579
duke@435 580 void BitMap::print_on(outputStream* st) const {
duke@435 581 tty->print("Bitmap(%d):", size());
duke@435 582 for (idx_t index = 0; index < size(); index++) {
duke@435 583 tty->print("%c", at(index) ? '1' : '0');
duke@435 584 }
duke@435 585 tty->cr();
duke@435 586 }
duke@435 587
duke@435 588 #endif
duke@435 589
duke@435 590
ysr@777 591 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
duke@435 592 : _bits_per_slot(bits_per_slot)
duke@435 593 , _map(map, size_in_slots * bits_per_slot)
duke@435 594 {
duke@435 595 }
duke@435 596
duke@435 597
duke@435 598 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
duke@435 599 : _bits_per_slot(bits_per_slot)
duke@435 600 , _map(size_in_slots * bits_per_slot)
duke@435 601 {
duke@435 602 }

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