1 /*
2 * Copyright (c) 2005, 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 #ifndef SHARE_VM_UTILITIES_BITMAP_INLINE_HPP
26 #define SHARE_VM_UTILITIES_BITMAP_INLINE_HPP
27
28 #include "runtime/atomic.hpp"
29 #include "utilities/bitMap.hpp"
30
31 inline void BitMap::set_bit(idx_t bit) {
32 verify_index(bit);
33 *word_addr(bit) |= bit_mask(bit);
34 }
35
36 inline void BitMap::clear_bit(idx_t bit) {
37 verify_index(bit);
38 *word_addr(bit) &= ~bit_mask(bit);
39 }
40
41 inline bool BitMap::par_set_bit(idx_t bit) {
42 verify_index(bit);
43 volatile bm_word_t* const addr = word_addr(bit);
44 const bm_word_t mask = bit_mask(bit);
45 bm_word_t old_val = *addr;
46
47 do {
48 const bm_word_t new_val = old_val | mask;
49 if (new_val == old_val) {
50 return false; // Someone else beat us to it.
51 }
52 const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val);
53 if (cur_val == old_val) {
54 return true; // Success.
55 }
56 old_val = cur_val; // The value changed, try again.
57 } while (true);
58 }
59
60 inline bool BitMap::par_clear_bit(idx_t bit) {
61 verify_index(bit);
62 volatile bm_word_t* const addr = word_addr(bit);
63 const bm_word_t mask = ~bit_mask(bit);
64 bm_word_t old_val = *addr;
65
66 do {
67 const bm_word_t new_val = old_val & mask;
68 if (new_val == old_val) {
69 return false; // Someone else beat us to it.
70 }
71 const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val);
72 if (cur_val == old_val) {
73 return true; // Success.
74 }
75 old_val = cur_val; // The value changed, try again.
76 } while (true);
77 }
78
79 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
80 if (hint == small_range && end - beg == 1) {
81 set_bit(beg);
82 } else {
83 if (hint == large_range) {
84 set_large_range(beg, end);
85 } else {
86 set_range(beg, end);
87 }
88 }
89 }
90
91 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
92 if (end - beg == 1) {
93 clear_bit(beg);
94 } else {
95 if (hint == large_range) {
96 clear_large_range(beg, end);
97 } else {
98 clear_range(beg, end);
99 }
100 }
101 }
102
103 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
104 if (hint == small_range && end - beg == 1) {
105 par_at_put(beg, true);
106 } else {
107 if (hint == large_range) {
108 par_at_put_large_range(beg, end, true);
109 } else {
110 par_at_put_range(beg, end, true);
111 }
112 }
113 }
114
115 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {
116 bm_word_t* map = _map;
117 for (idx_t i = beg; i < end; ++i) map[i] = ~(bm_word_t)0;
118 }
119
120 inline void BitMap::clear_range_of_words(bm_word_t* map, idx_t beg, idx_t end) {
121 for (idx_t i = beg; i < end; ++i) map[i] = 0;
122 }
123
124 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) {
125 clear_range_of_words(_map, beg, end);
126 }
127
128 inline void BitMap::clear() {
129 clear_range_of_words(0, size_in_words());
130 }
131
132 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
133 if (hint == small_range && end - beg == 1) {
134 par_at_put(beg, false);
135 } else {
136 if (hint == large_range) {
137 par_at_put_large_range(beg, end, false);
138 } else {
139 par_at_put_range(beg, end, false);
140 }
141 }
142 }
143
144 inline BitMap::idx_t
145 BitMap::get_next_one_offset(idx_t l_offset, idx_t r_offset) const {
146 assert(l_offset <= size(), "BitMap index out of bounds");
147 assert(r_offset <= size(), "BitMap index out of bounds");
148 assert(l_offset <= r_offset, "l_offset > r_offset ?");
149
150 if (l_offset == r_offset) {
151 return l_offset;
152 }
153 idx_t index = word_index(l_offset);
154 idx_t r_index = word_index(r_offset-1) + 1;
155 idx_t res_offset = l_offset;
156
157 // check bits including and to the _left_ of offset's position
158 idx_t pos = bit_in_word(res_offset);
159 bm_word_t res = map(index) >> pos;
160 if (res != 0) {
161 // find the position of the 1-bit
162 for (; !(res & 1); res_offset++) {
163 res = res >> 1;
164 }
165
166 #ifdef ASSERT
167 // In the following assert, if r_offset is not bitamp word aligned,
168 // checking that res_offset is strictly less than r_offset is too
169 // strong and will trip the assert.
170 //
171 // Consider the case where l_offset is bit 15 and r_offset is bit 17
172 // of the same map word, and where bits [15:16:17:18] == [00:00:00:01].
173 // All the bits in the range [l_offset:r_offset) are 0.
174 // The loop that calculates res_offset, above, would yield the offset
175 // of bit 18 because it's in the same map word as l_offset and there
176 // is a set bit in that map word above l_offset (i.e. res != NoBits).
177 //
178 // In this case, however, we can assert is that res_offset is strictly
179 // less than size() since we know that there is at least one set bit
180 // at an offset above, but in the same map word as, r_offset.
181 // Otherwise, if r_offset is word aligned then it will not be in the
182 // same map word as l_offset (unless it equals l_offset). So either
183 // there won't be a set bit between l_offset and the end of it's map
184 // word (i.e. res == NoBits), or res_offset will be less than r_offset.
185
186 idx_t limit = is_word_aligned(r_offset) ? r_offset : size();
187 assert(res_offset >= l_offset && res_offset < limit, "just checking");
188 #endif // ASSERT
189 return MIN2(res_offset, r_offset);
190 }
191 // skip over all word length 0-bit runs
192 for (index++; index < r_index; index++) {
193 res = map(index);
194 if (res != 0) {
195 // found a 1, return the offset
196 for (res_offset = bit_index(index); !(res & 1); res_offset++) {
197 res = res >> 1;
198 }
199 assert(res & 1, "tautology; see loop condition");
200 assert(res_offset >= l_offset, "just checking");
201 return MIN2(res_offset, r_offset);
202 }
203 }
204 return r_offset;
205 }
206
207 inline BitMap::idx_t
208 BitMap::get_next_zero_offset(idx_t l_offset, idx_t r_offset) const {
209 assert(l_offset <= size(), "BitMap index out of bounds");
210 assert(r_offset <= size(), "BitMap index out of bounds");
211 assert(l_offset <= r_offset, "l_offset > r_offset ?");
212
213 if (l_offset == r_offset) {
214 return l_offset;
215 }
216 idx_t index = word_index(l_offset);
217 idx_t r_index = word_index(r_offset-1) + 1;
218 idx_t res_offset = l_offset;
219
220 // check bits including and to the _left_ of offset's position
221 idx_t pos = bit_in_word(res_offset);
222 bm_word_t res = ~map(index) >> pos; // flip bits and shift for l_offset
223
224 if (res != 0) {
225 // find the position of the 1-bit
226 for (; !(res & 1); res_offset++) {
227 res = res >> 1;
228 }
229 assert(res_offset >= l_offset, "just checking");
230 return MIN2(res_offset, r_offset);
231 }
232 // skip over all word length 1-bit runs
233 for (index++; index < r_index; index++) {
234 res = map(index);
235 if (res != ~(bm_word_t)0) {
236 // found a 0, return the offset
237 for (res_offset = index << LogBitsPerWord; res & 1;
238 res_offset++) {
239 res = res >> 1;
240 }
241 assert(!(res & 1), "tautology; see loop condition");
242 assert(res_offset >= l_offset, "just checking");
243 return MIN2(res_offset, r_offset);
244 }
245 }
246 return r_offset;
247 }
248
249 inline BitMap::idx_t
250 BitMap::get_next_one_offset_aligned_right(idx_t l_offset, idx_t r_offset) const
251 {
252 verify_range(l_offset, r_offset);
253 assert(bit_in_word(r_offset) == 0, "r_offset not word-aligned");
254
255 if (l_offset == r_offset) {
256 return l_offset;
257 }
258 idx_t index = word_index(l_offset);
259 idx_t r_index = word_index(r_offset);
260 idx_t res_offset = l_offset;
261
262 // check bits including and to the _left_ of offset's position
263 bm_word_t res = map(index) >> bit_in_word(res_offset);
264 if (res != 0) {
265 // find the position of the 1-bit
266 for (; !(res & 1); res_offset++) {
267 res = res >> 1;
268 }
269 assert(res_offset >= l_offset &&
270 res_offset < r_offset, "just checking");
271 return res_offset;
272 }
273 // skip over all word length 0-bit runs
274 for (index++; index < r_index; index++) {
275 res = map(index);
276 if (res != 0) {
277 // found a 1, return the offset
278 for (res_offset = bit_index(index); !(res & 1); res_offset++) {
279 res = res >> 1;
280 }
281 assert(res & 1, "tautology; see loop condition");
282 assert(res_offset >= l_offset && res_offset < r_offset, "just checking");
283 return res_offset;
284 }
285 }
286 return r_offset;
287 }
288
289
290 // Returns a bit mask for a range of bits [beg, end) within a single word. Each
291 // bit in the mask is 0 if the bit is in the range, 1 if not in the range. The
292 // returned mask can be used directly to clear the range, or inverted to set the
293 // range. Note: end must not be 0.
294 inline BitMap::bm_word_t
295 BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const {
296 assert(end != 0, "does not work when end == 0");
297 assert(beg == end || word_index(beg) == word_index(end - 1),
298 "must be a single-word range");
299 bm_word_t mask = bit_mask(beg) - 1; // low (right) bits
300 if (bit_in_word(end) != 0) {
301 mask |= ~(bit_mask(end) - 1); // high (left) bits
302 }
303 return mask;
304 }
305
306 inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) {
307 memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(bm_word_t));
308 }
309
310 inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) {
311 memset(_map + beg, 0, (end - beg) * sizeof(bm_word_t));
312 }
313
314 inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const {
315 idx_t bit_rounded_up = bit + (BitsPerWord - 1);
316 // Check for integer arithmetic overflow.
317 return bit_rounded_up > bit ? word_index(bit_rounded_up) : size_in_words();
318 }
319
320 inline bool BitMap2D::is_valid_index(idx_t slot_index, idx_t bit_within_slot_index) {
321 verify_bit_within_slot_index(bit_within_slot_index);
322 return (bit_index(slot_index, bit_within_slot_index) < size_in_bits());
323 }
324
325 inline bool BitMap2D::at(idx_t slot_index, idx_t bit_within_slot_index) const {
326 verify_bit_within_slot_index(bit_within_slot_index);
327 return _map.at(bit_index(slot_index, bit_within_slot_index));
328 }
329
330 inline void BitMap2D::set_bit(idx_t slot_index, idx_t bit_within_slot_index) {
331 verify_bit_within_slot_index(bit_within_slot_index);
332 _map.set_bit(bit_index(slot_index, bit_within_slot_index));
333 }
334
335 inline void BitMap2D::clear_bit(idx_t slot_index, idx_t bit_within_slot_index) {
336 verify_bit_within_slot_index(bit_within_slot_index);
337 _map.clear_bit(bit_index(slot_index, bit_within_slot_index));
338 }
339
340 inline void BitMap2D::at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
341 verify_bit_within_slot_index(bit_within_slot_index);
342 _map.at_put(bit_index(slot_index, bit_within_slot_index), value);
343 }
344
345 inline void BitMap2D::at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
346 verify_bit_within_slot_index(bit_within_slot_index);
347
348 idx_t bit = bit_index(slot_index, bit_within_slot_index);
349 if (bit >= _map.size()) {
350 _map.resize(2 * MAX2(_map.size(), bit));
351 }
352 _map.at_put(bit, value);
353 }
354
355 #endif // SHARE_VM_UTILITIES_BITMAP_INLINE_HPP