1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "memory/resourceArea.hpp"
28 #include "runtime/atomic.hpp"
29 #include "utilities/bitMap.inline.hpp"
30 #include "utilities/copy.hpp"
31 #include "utilities/debug.hpp"
32
33 STATIC_ASSERT(sizeof(BitMap::bm_word_t) == BytesPerWord); // "Implementation assumption."
34
35 typedef BitMap::bm_word_t bm_word_t;
36 typedef BitMap::idx_t idx_t;
37
38 class ResourceBitMapAllocator : StackObj {
39 public:
40 bm_word_t* allocate(idx_t size_in_words) const {
41 return NEW_RESOURCE_ARRAY(bm_word_t, size_in_words);
42 }
43 void free(bm_word_t* map, idx_t size_in_words) const {
44 // Don't free resource allocated arrays.
45 }
46 };
47
48 class CHeapBitMapAllocator : StackObj {
49 MEMFLAGS _flags;
50
51 public:
52 CHeapBitMapAllocator(MEMFLAGS flags) : _flags(flags) {}
53 bm_word_t* allocate(size_t size_in_words) const {
54 return ArrayAllocator<bm_word_t>::allocate(size_in_words, _flags);
55 }
56 void free(bm_word_t* map, idx_t size_in_words) const {
57 ArrayAllocator<bm_word_t>::free(map, size_in_words);
58 }
59 };
60
61 class ArenaBitMapAllocator : StackObj {
62 Arena* _arena;
63
64 public:
65 ArenaBitMapAllocator(Arena* arena) : _arena(arena) {}
66 bm_word_t* allocate(idx_t size_in_words) const {
67 return (bm_word_t*)_arena->Amalloc(size_in_words * BytesPerWord);
68 }
69 void free(bm_word_t* map, idx_t size_in_words) const {
70 // ArenaBitMaps currently don't free memory.
71 }
72 };
73
74 template <class Allocator>
75 BitMap::bm_word_t* BitMap::reallocate(const Allocator& allocator, bm_word_t* old_map, idx_t old_size_in_bits, idx_t new_size_in_bits) {
76 size_t old_size_in_words = calc_size_in_words(old_size_in_bits);
77 size_t new_size_in_words = calc_size_in_words(new_size_in_bits);
78
79 bm_word_t* map = NULL;
80
81 if (new_size_in_words > 0) {
82 map = allocator.allocate(new_size_in_words);
83
84 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) map,
85 MIN2(old_size_in_words, new_size_in_words));
86
87 if (new_size_in_words > old_size_in_words) {
88 clear_range_of_words(map, old_size_in_words, new_size_in_words);
89 }
90 }
91
92 if (old_map != NULL) {
93 allocator.free(old_map, old_size_in_words);
94 }
95
96 return map;
97 }
98
99 template <class Allocator>
100 bm_word_t* BitMap::allocate(const Allocator& allocator, idx_t size_in_bits) {
101 // Reuse reallocate to ensure that the new memory is cleared.
102 return reallocate(allocator, NULL, 0, size_in_bits);
103 }
104
105 template <class Allocator>
106 void BitMap::free(const Allocator& allocator, bm_word_t* map, idx_t size_in_bits) {
107 bm_word_t* ret = reallocate(allocator, map, size_in_bits, 0);
108 assert(ret == NULL, "Reallocate shouldn't have allocated");
109 }
110
111 template <class Allocator>
112 void BitMap::resize(const Allocator& allocator, idx_t new_size_in_bits) {
113 bm_word_t* new_map = reallocate(allocator, map(), size(), new_size_in_bits);
114
115 update(new_map, new_size_in_bits);
116 }
117
118 template <class Allocator>
119 void BitMap::initialize(const Allocator& allocator, idx_t size_in_bits) {
120 assert(map() == NULL, "precondition");
121 assert(size() == 0, "precondition");
122
123 resize(allocator, size_in_bits);
124 }
125
126 template <class Allocator>
127 void BitMap::reinitialize(const Allocator& allocator, idx_t new_size_in_bits) {
128 // Remove previous bits.
129 resize(allocator, 0);
130
131 initialize(allocator, new_size_in_bits);
132 }
133
134 ResourceBitMap::ResourceBitMap(idx_t size_in_bits)
135 : BitMap(allocate(ResourceBitMapAllocator(), size_in_bits), size_in_bits) {
136 }
137
138 void ResourceBitMap::resize(idx_t new_size_in_bits) {
139 BitMap::resize(ResourceBitMapAllocator(), new_size_in_bits);
140 }
141
142 void ResourceBitMap::initialize(idx_t size_in_bits) {
143 BitMap::initialize(ResourceBitMapAllocator(), size_in_bits);
144 }
145
146 void ResourceBitMap::reinitialize(idx_t size_in_bits) {
147 BitMap::reinitialize(ResourceBitMapAllocator(), size_in_bits);
148 }
149
150 ArenaBitMap::ArenaBitMap(Arena* arena, idx_t size_in_bits)
151 : BitMap(allocate(ArenaBitMapAllocator(arena), size_in_bits), size_in_bits) {
152 }
153
154 CHeapBitMap::CHeapBitMap(idx_t size_in_bits, MEMFLAGS flags)
155 : BitMap(allocate(CHeapBitMapAllocator(flags), size_in_bits), size_in_bits), _flags(flags) {
156 }
157
158 CHeapBitMap::~CHeapBitMap() {
159 free(CHeapBitMapAllocator(_flags), map(), size());
160 }
161
162 void CHeapBitMap::resize(idx_t new_size_in_bits) {
163 BitMap::resize(CHeapBitMapAllocator(_flags), new_size_in_bits);
164 }
165
166 void CHeapBitMap::initialize(idx_t size_in_bits) {
167 BitMap::initialize(CHeapBitMapAllocator(_flags), size_in_bits);
168 }
169
170 void CHeapBitMap::reinitialize(idx_t size_in_bits) {
171 BitMap::reinitialize(CHeapBitMapAllocator(_flags), size_in_bits);
172 }
173
174 #ifdef ASSERT
175 void BitMap::verify_index(idx_t index) const {
176 assert(index < _size, "BitMap index out of bounds");
177 }
178
179 void BitMap::verify_range(idx_t beg_index, idx_t end_index) const {
180 assert(beg_index <= end_index, "BitMap range error");
181 // Note that [0,0) and [size,size) are both valid ranges.
182 if (end_index != _size) verify_index(end_index);
183 }
184 #endif // #ifdef ASSERT
185
186 void BitMap::pretouch() {
187 os::pretouch_memory(word_addr(0), word_addr(size()));
188 }
189
190 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
191 // With a valid range (beg <= end), this test ensures that end != 0, as
192 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
193 if (beg != end) {
194 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
195 *word_addr(beg) |= ~mask;
196 }
197 }
198
199 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
200 // With a valid range (beg <= end), this test ensures that end != 0, as
201 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
202 if (beg != end) {
203 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
204 *word_addr(beg) &= mask;
205 }
206 }
207
208 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
209 assert(value == 0 || value == 1, "0 for clear, 1 for set");
210 // With a valid range (beg <= end), this test ensures that end != 0, as
211 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
212 if (beg != end) {
213 bm_word_t* pw = word_addr(beg);
214 bm_word_t w = *pw;
215 bm_word_t mr = inverted_bit_mask_for_range(beg, end);
216 bm_word_t nw = value ? (w | ~mr) : (w & mr);
217 while (true) {
218 bm_word_t res = Atomic::cmpxchg(nw, pw, w);
219 if (res == w) break;
220 w = res;
221 nw = value ? (w | ~mr) : (w & mr);
222 }
223 }
224 }
225
226 void BitMap::set_range(idx_t beg, idx_t end) {
227 verify_range(beg, end);
228
229 idx_t beg_full_word = word_index_round_up(beg);
230 idx_t end_full_word = word_index(end);
231
232 if (beg_full_word < end_full_word) {
233 // The range includes at least one full word.
234 set_range_within_word(beg, bit_index(beg_full_word));
235 set_range_of_words(beg_full_word, end_full_word);
236 set_range_within_word(bit_index(end_full_word), end);
237 } else {
238 // The range spans at most 2 partial words.
239 idx_t boundary = MIN2(bit_index(beg_full_word), end);
240 set_range_within_word(beg, boundary);
241 set_range_within_word(boundary, end);
242 }
243 }
244
245 void BitMap::clear_range(idx_t beg, idx_t end) {
246 verify_range(beg, end);
247
248 idx_t beg_full_word = word_index_round_up(beg);
249 idx_t end_full_word = word_index(end);
250
251 if (beg_full_word < end_full_word) {
252 // The range includes at least one full word.
253 clear_range_within_word(beg, bit_index(beg_full_word));
254 clear_range_of_words(beg_full_word, end_full_word);
255 clear_range_within_word(bit_index(end_full_word), end);
256 } else {
257 // The range spans at most 2 partial words.
258 idx_t boundary = MIN2(bit_index(beg_full_word), end);
259 clear_range_within_word(beg, boundary);
260 clear_range_within_word(boundary, end);
261 }
262 }
263
264 void BitMap::set_large_range(idx_t beg, idx_t end) {
265 verify_range(beg, end);
266
267 idx_t beg_full_word = word_index_round_up(beg);
268 idx_t end_full_word = word_index(end);
269
270 assert(end_full_word - beg_full_word >= 32,
271 "the range must include at least 32 bytes");
272
273 // The range includes at least one full word.
274 set_range_within_word(beg, bit_index(beg_full_word));
275 set_large_range_of_words(beg_full_word, end_full_word);
276 set_range_within_word(bit_index(end_full_word), end);
277 }
278
279 void BitMap::clear_large_range(idx_t beg, idx_t end) {
280 verify_range(beg, end);
281
282 idx_t beg_full_word = word_index_round_up(beg);
283 idx_t end_full_word = word_index(end);
284
285 if (end_full_word - beg_full_word < 32) {
286 clear_range(beg, end);
287 return;
288 }
289
290 // The range includes at least one full word.
291 clear_range_within_word(beg, bit_index(beg_full_word));
292 clear_large_range_of_words(beg_full_word, end_full_word);
293 clear_range_within_word(bit_index(end_full_word), end);
294 }
295
296 void BitMap::at_put(idx_t offset, bool value) {
297 if (value) {
298 set_bit(offset);
299 } else {
300 clear_bit(offset);
301 }
302 }
303
304 // Return true to indicate that this thread changed
305 // the bit, false to indicate that someone else did.
306 // In either case, the requested bit is in the
307 // requested state some time during the period that
308 // this thread is executing this call. More importantly,
309 // if no other thread is executing an action to
310 // change the requested bit to a state other than
311 // the one that this thread is trying to set it to,
312 // then the the bit is in the expected state
313 // at exit from this method. However, rather than
314 // make such a strong assertion here, based on
315 // assuming such constrained use (which though true
316 // today, could change in the future to service some
317 // funky parallel algorithm), we encourage callers
318 // to do such verification, as and when appropriate.
319 bool BitMap::par_at_put(idx_t bit, bool value) {
320 return value ? par_set_bit(bit) : par_clear_bit(bit);
321 }
322
323 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
324 if (value) {
325 set_range(start_offset, end_offset);
326 } else {
327 clear_range(start_offset, end_offset);
328 }
329 }
330
331 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
332 verify_range(beg, end);
333
334 idx_t beg_full_word = word_index_round_up(beg);
335 idx_t end_full_word = word_index(end);
336
337 if (beg_full_word < end_full_word) {
338 // The range includes at least one full word.
339 par_put_range_within_word(beg, bit_index(beg_full_word), value);
340 if (value) {
341 set_range_of_words(beg_full_word, end_full_word);
342 } else {
343 clear_range_of_words(beg_full_word, end_full_word);
344 }
345 par_put_range_within_word(bit_index(end_full_word), end, value);
346 } else {
347 // The range spans at most 2 partial words.
348 idx_t boundary = MIN2(bit_index(beg_full_word), end);
349 par_put_range_within_word(beg, boundary, value);
350 par_put_range_within_word(boundary, end, value);
351 }
352
353 }
354
355 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
356 if (value) {
357 set_large_range(beg, end);
358 } else {
359 clear_large_range(beg, end);
360 }
361 }
362
363 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
364 verify_range(beg, end);
365
366 idx_t beg_full_word = word_index_round_up(beg);
367 idx_t end_full_word = word_index(end);
368
369 assert(end_full_word - beg_full_word >= 32,
370 "the range must include at least 32 bytes");
371
372 // The range includes at least one full word.
373 par_put_range_within_word(beg, bit_index(beg_full_word), value);
374 if (value) {
375 set_large_range_of_words(beg_full_word, end_full_word);
376 } else {
377 clear_large_range_of_words(beg_full_word, end_full_word);
378 }
379 par_put_range_within_word(bit_index(end_full_word), end, value);
380 }
381
382 inline bm_word_t tail_mask(idx_t tail_bits) {
383 assert(tail_bits != 0, "precondition"); // Works, but shouldn't be called.
384 assert(tail_bits < (idx_t)BitsPerWord, "precondition");
385 return (bm_word_t(1) << tail_bits) - 1;
386 }
387
388 // Get the low tail_bits of value, which is the last partial word of a map.
389 inline bm_word_t tail_of_map(bm_word_t value, idx_t tail_bits) {
390 return value & tail_mask(tail_bits);
391 }
392
393 // Compute the new last word of a map with a non-aligned length.
394 // new_value has the new trailing bits of the map in the low tail_bits.
395 // old_value is the last word of the map, including bits beyond the end.
396 // Returns old_value with the low tail_bits replaced by the corresponding
397 // bits in new_value.
398 inline bm_word_t merge_tail_of_map(bm_word_t new_value,
399 bm_word_t old_value,
400 idx_t tail_bits) {
401 bm_word_t mask = tail_mask(tail_bits);
402 return (new_value & mask) | (old_value & ~mask);
403 }
404
405 bool BitMap::contains(const BitMap& other) const {
406 assert(size() == other.size(), "must have same size");
407 const bm_word_t* dest_map = map();
408 const bm_word_t* other_map = other.map();
409 idx_t limit = word_index(size());
410 for (idx_t index = 0; index < limit; ++index) {
411 // false if other bitmap has bits set which are clear in this bitmap.
412 if ((~dest_map[index] & other_map[index]) != 0) return false;
413 }
414 idx_t rest = bit_in_word(size());
415 // true unless there is a partial-word tail in which the other
416 // bitmap has bits set which are clear in this bitmap.
417 return (rest == 0) || tail_of_map(~dest_map[limit] & other_map[limit], rest) == 0;
418 }
419
420 bool BitMap::intersects(const BitMap& other) const {
421 assert(size() == other.size(), "must have same size");
422 const bm_word_t* dest_map = map();
423 const bm_word_t* other_map = other.map();
424 idx_t limit = word_index(size());
425 for (idx_t index = 0; index < limit; ++index) {
426 if ((dest_map[index] & other_map[index]) != 0) return true;
427 }
428 idx_t rest = bit_in_word(size());
429 // false unless there is a partial-word tail with non-empty intersection.
430 return (rest > 0) && tail_of_map(dest_map[limit] & other_map[limit], rest) != 0;
431 }
432
433 void BitMap::set_union(const BitMap& other) {
434 assert(size() == other.size(), "must have same size");
435 bm_word_t* dest_map = map();
436 const bm_word_t* other_map = other.map();
437 idx_t limit = word_index(size());
438 for (idx_t index = 0; index < limit; ++index) {
439 dest_map[index] |= other_map[index];
440 }
441 idx_t rest = bit_in_word(size());
442 if (rest > 0) {
443 bm_word_t orig = dest_map[limit];
444 dest_map[limit] = merge_tail_of_map(orig | other_map[limit], orig, rest);
445 }
446 }
447
448 void BitMap::set_difference(const BitMap& other) {
449 assert(size() == other.size(), "must have same size");
450 bm_word_t* dest_map = map();
451 const bm_word_t* other_map = other.map();
452 idx_t limit = word_index(size());
453 for (idx_t index = 0; index < limit; ++index) {
454 dest_map[index] &= ~other_map[index];
455 }
456 idx_t rest = bit_in_word(size());
457 if (rest > 0) {
458 bm_word_t orig = dest_map[limit];
459 dest_map[limit] = merge_tail_of_map(orig & ~other_map[limit], orig, rest);
460 }
461 }
462
463 void BitMap::set_intersection(const BitMap& other) {
464 assert(size() == other.size(), "must have same size");
465 bm_word_t* dest_map = map();
466 const bm_word_t* other_map = other.map();
467 idx_t limit = word_index(size());
468 for (idx_t index = 0; index < limit; ++index) {
469 dest_map[index] &= other_map[index];
470 }
471 idx_t rest = bit_in_word(size());
472 if (rest > 0) {
473 bm_word_t orig = dest_map[limit];
474 dest_map[limit] = merge_tail_of_map(orig & other_map[limit], orig, rest);
475 }
476 }
477
478 bool BitMap::set_union_with_result(const BitMap& other) {
479 assert(size() == other.size(), "must have same size");
480 bool changed = false;
481 bm_word_t* dest_map = map();
482 const bm_word_t* other_map = other.map();
483 idx_t limit = word_index(size());
484 for (idx_t index = 0; index < limit; ++index) {
485 bm_word_t orig = dest_map[index];
486 bm_word_t temp = orig | other_map[index];
487 changed = changed || (temp != orig);
488 dest_map[index] = temp;
489 }
490 idx_t rest = bit_in_word(size());
491 if (rest > 0) {
492 bm_word_t orig = dest_map[limit];
493 bm_word_t temp = merge_tail_of_map(orig | other_map[limit], orig, rest);
494 changed = changed || (temp != orig);
495 dest_map[limit] = temp;
496 }
497 return changed;
498 }
499
500 bool BitMap::set_difference_with_result(const BitMap& other) {
501 assert(size() == other.size(), "must have same size");
502 bool changed = false;
503 bm_word_t* dest_map = map();
504 const bm_word_t* other_map = other.map();
505 idx_t limit = word_index(size());
506 for (idx_t index = 0; index < limit; ++index) {
507 bm_word_t orig = dest_map[index];
508 bm_word_t temp = orig & ~other_map[index];
509 changed = changed || (temp != orig);
510 dest_map[index] = temp;
511 }
512 idx_t rest = bit_in_word(size());
513 if (rest > 0) {
514 bm_word_t orig = dest_map[limit];
515 bm_word_t temp = merge_tail_of_map(orig & ~other_map[limit], orig, rest);
516 changed = changed || (temp != orig);
517 dest_map[limit] = temp;
518 }
519 return changed;
520 }
521
522 bool BitMap::set_intersection_with_result(const BitMap& other) {
523 assert(size() == other.size(), "must have same size");
524 bool changed = false;
525 bm_word_t* dest_map = map();
526 const bm_word_t* other_map = other.map();
527 idx_t limit = word_index(size());
528 for (idx_t index = 0; index < limit; ++index) {
529 bm_word_t orig = dest_map[index];
530 bm_word_t temp = orig & other_map[index];
531 changed = changed || (temp != orig);
532 dest_map[index] = temp;
533 }
534 idx_t rest = bit_in_word(size());
535 if (rest > 0) {
536 bm_word_t orig = dest_map[limit];
537 bm_word_t temp = merge_tail_of_map(orig & other_map[limit], orig, rest);
538 changed = changed || (temp != orig);
539 dest_map[limit] = temp;
540 }
541 return changed;
542 }
543
544 void BitMap::set_from(const BitMap& other) {
545 assert(size() == other.size(), "must have same size");
546 bm_word_t* dest_map = map();
547 const bm_word_t* other_map = other.map();
548 idx_t copy_words = word_index(size());
549 Copy::disjoint_words((HeapWord*)other_map, (HeapWord*)dest_map, copy_words);
550 idx_t rest = bit_in_word(size());
551 if (rest > 0) {
552 dest_map[copy_words] = merge_tail_of_map(other_map[copy_words],
553 dest_map[copy_words],
554 rest);
555 }
556 }
557
558 bool BitMap::is_same(const BitMap& other) const {
559 assert(size() == other.size(), "must have same size");
560 const bm_word_t* dest_map = map();
561 const bm_word_t* other_map = other.map();
562 idx_t limit = word_index(size());
563 for (idx_t index = 0; index < limit; ++index) {
564 if (dest_map[index] != other_map[index]) return false;
565 }
566 idx_t rest = bit_in_word(size());
567 return (rest == 0) || (tail_of_map(dest_map[limit] ^ other_map[limit], rest) == 0);
568 }
569
570 bool BitMap::is_full() const {
571 const bm_word_t* words = map();
572 idx_t limit = word_index(size());
573 for (idx_t index = 0; index < limit; ++index) {
574 if (~words[index] != 0) return false;
575 }
576 idx_t rest = bit_in_word(size());
577 return (rest == 0) || (tail_of_map(~words[limit], rest) == 0);
578 }
579
580 bool BitMap::is_empty() const {
581 const bm_word_t* words = map();
582 idx_t limit = word_index(size());
583 for (idx_t index = 0; index < limit; ++index) {
584 if (words[index] != 0) return false;
585 }
586 idx_t rest = bit_in_word(size());
587 return (rest == 0) || (tail_of_map(words[limit], rest) == 0);
588 }
589
590 void BitMap::clear_large() {
591 clear_large_range_of_words(0, size_in_words());
592 }
593
594 // Note that if the closure itself modifies the bitmap
595 // then modifications in and to the left of the _bit_ being
596 // currently sampled will not be seen. Note also that the
597 // interval [leftOffset, rightOffset) is right open.
598 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
599 verify_range(leftOffset, rightOffset);
600
601 idx_t startIndex = word_index(leftOffset);
602 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
603 for (idx_t index = startIndex, offset = leftOffset;
604 offset < rightOffset && index < endIndex;
605 offset = (++index) << LogBitsPerWord) {
606 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
607 for (; offset < rightOffset && rest != 0; offset++) {
608 if (rest & 1) {
609 if (!blk->do_bit(offset)) return false;
610 // resample at each closure application
611 // (see, for instance, CMS bug 4525989)
612 rest = map(index) >> (offset & (BitsPerWord -1));
613 }
614 rest = rest >> 1;
615 }
616 }
617 return true;
618 }
619
620 const BitMap::idx_t* BitMap::_pop_count_table = NULL;
621
622 void BitMap::init_pop_count_table() {
623 if (_pop_count_table == NULL) {
624 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
625 for (uint i = 0; i < 256; i++) {
626 table[i] = num_set_bits(i);
627 }
628
629 if (!Atomic::replace_if_null(table, &_pop_count_table)) {
630 guarantee(_pop_count_table != NULL, "invariant");
631 FREE_C_HEAP_ARRAY(idx_t, table);
632 }
633 }
634 }
635
636 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
637 idx_t bits = 0;
638
639 while (w != 0) {
640 while ((w & 1) == 0) {
641 w >>= 1;
642 }
643 bits++;
644 w >>= 1;
645 }
646 return bits;
647 }
648
649 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
650 assert(_pop_count_table != NULL, "precondition");
651 return _pop_count_table[c];
652 }
653
654 BitMap::idx_t BitMap::count_one_bits() const {
655 init_pop_count_table(); // If necessary.
656 idx_t sum = 0;
657 typedef unsigned char uchar;
658 for (idx_t i = 0; i < size_in_words(); i++) {
659 bm_word_t w = map()[i];
660 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
661 sum += num_set_bits_from_table(uchar(w & 255));
662 w >>= 8;
663 }
664 }
665 return sum;
666 }
667
668 void BitMap::print_on_error(outputStream* st, const char* prefix) const {
669 st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")",
670 prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte)));
671 }
672
673 #ifndef PRODUCT
674
675 void BitMap::print_on(outputStream* st) const {
676 tty->print("Bitmap(" SIZE_FORMAT "):", size());
677 for (idx_t index = 0; index < size(); index++) {
678 tty->print("%c", at(index) ? '1' : '0');
679 }
680 tty->cr();
681 }
682
683 #endif
--- EOF ---