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 = (bm_word_t) Atomic::cmpxchg_ptr((void*) new_val,
53 (volatile void*) addr,
54 (void*) old_val);
55 if (cur_val == old_val) {
56 return true; // Success.
57 }
58 old_val = cur_val; // The value changed, try again.
59 } while (true);
60 }
61
62 inline bool BitMap::par_clear_bit(idx_t bit) {
63 verify_index(bit);
64 volatile bm_word_t* const addr = word_addr(bit);
65 const bm_word_t mask = ~bit_mask(bit);
66 bm_word_t old_val = *addr;
67
68 do {
69 const bm_word_t new_val = old_val & mask;
70 if (new_val == old_val) {
71 return false; // Someone else beat us to it.
72 }
73 const bm_word_t cur_val = (bm_word_t) Atomic::cmpxchg_ptr((void*) new_val,
74 (volatile void*) addr,
75 (void*) old_val);
76 if (cur_val == old_val) {
77 return true; // Success.
78 }
79 old_val = cur_val; // The value changed, try again.
80 } while (true);
81 }
82
83 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
84 if (hint == small_range && end - beg == 1) {
85 set_bit(beg);
86 } else {
87 if (hint == large_range) {
88 set_large_range(beg, end);
89 } else {
90 set_range(beg, end);
91 }
92 }
93 }
94
95 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
96 if (end - beg == 1) {
97 clear_bit(beg);
98 } else {
99 if (hint == large_range) {
100 clear_large_range(beg, end);
101 } else {
102 clear_range(beg, end);
103 }
104 }
105 }
106
107 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
108 if (hint == small_range && end - beg == 1) {
109 par_at_put(beg, true);
110 } else {
111 if (hint == large_range) {
112 par_at_put_large_range(beg, end, true);
113 } else {
114 par_at_put_range(beg, end, true);
115 }
116 }
117 }
118
119 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {
120 bm_word_t* map = _map;
121 for (idx_t i = beg; i < end; ++i) map[i] = ~(bm_word_t)0;
122 }
123
124 inline void BitMap::clear_range_of_words(bm_word_t* map, idx_t beg, idx_t end) {
125 for (idx_t i = beg; i < end; ++i) map[i] = 0;
126 }
127
128 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) {
129 clear_range_of_words(_map, beg, end);
130 }
131
132 inline void BitMap::clear() {
133 clear_range_of_words(0, size_in_words());
134 }
135
136 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
137 if (hint == small_range && end - beg == 1) {
138 par_at_put(beg, false);
139 } else {
140 if (hint == large_range) {
141 par_at_put_large_range(beg, end, false);
142 } else {
143 par_at_put_range(beg, end, false);
144 }
145 }
146 }
147
148 inline BitMap::idx_t
149 BitMap::get_next_one_offset(idx_t l_offset, idx_t r_offset) const {
150 assert(l_offset <= size(), "BitMap index out of bounds");
151 assert(r_offset <= size(), "BitMap index out of bounds");
152 assert(l_offset <= r_offset, "l_offset > r_offset ?");
153
154 if (l_offset == r_offset) {
155 return l_offset;
156 }
157 idx_t index = word_index(l_offset);
158 idx_t r_index = word_index(r_offset-1) + 1;
159 idx_t res_offset = l_offset;
160
161 // check bits including and to the _left_ of offset's position
162 idx_t pos = bit_in_word(res_offset);
163 bm_word_t res = map(index) >> pos;
164 if (res != 0) {
165 // find the position of the 1-bit
166 for (; !(res & 1); res_offset++) {
167 res = res >> 1;
168 }
169
170 #ifdef ASSERT
171 // In the following assert, if r_offset is not bitamp word aligned,
172 // checking that res_offset is strictly less than r_offset is too
173 // strong and will trip the assert.
174 //
175 // Consider the case where l_offset is bit 15 and r_offset is bit 17
176 // of the same map word, and where bits [15:16:17:18] == [00:00:00:01].
177 // All the bits in the range [l_offset:r_offset) are 0.
178 // The loop that calculates res_offset, above, would yield the offset
179 // of bit 18 because it's in the same map word as l_offset and there
180 // is a set bit in that map word above l_offset (i.e. res != NoBits).
181 //
182 // In this case, however, we can assert is that res_offset is strictly
183 // less than size() since we know that there is at least one set bit
184 // at an offset above, but in the same map word as, r_offset.
185 // Otherwise, if r_offset is word aligned then it will not be in the
186 // same map word as l_offset (unless it equals l_offset). So either
187 // there won't be a set bit between l_offset and the end of it's map
188 // word (i.e. res == NoBits), or res_offset will be less than r_offset.
189
190 idx_t limit = is_word_aligned(r_offset) ? r_offset : size();
191 assert(res_offset >= l_offset && res_offset < limit, "just checking");
192 #endif // ASSERT
193 return MIN2(res_offset, r_offset);
194 }
195 // skip over all word length 0-bit runs
196 for (index++; index < r_index; index++) {
197 res = map(index);
198 if (res != 0) {
199 // found a 1, return the offset
200 for (res_offset = bit_index(index); !(res & 1); res_offset++) {
201 res = res >> 1;
202 }
203 assert(res & 1, "tautology; see loop condition");
204 assert(res_offset >= l_offset, "just checking");
205 return MIN2(res_offset, r_offset);
206 }
207 }
208 return r_offset;
209 }
210
211 inline BitMap::idx_t
212 BitMap::get_next_zero_offset(idx_t l_offset, idx_t r_offset) const {
213 assert(l_offset <= size(), "BitMap index out of bounds");
214 assert(r_offset <= size(), "BitMap index out of bounds");
215 assert(l_offset <= r_offset, "l_offset > r_offset ?");
216
217 if (l_offset == r_offset) {
218 return l_offset;
219 }
220 idx_t index = word_index(l_offset);
221 idx_t r_index = word_index(r_offset-1) + 1;
222 idx_t res_offset = l_offset;
223
224 // check bits including and to the _left_ of offset's position
225 idx_t pos = res_offset & (BitsPerWord - 1);
226 bm_word_t res = (map(index) >> pos) | left_n_bits((int)pos);
227
228 if (res != ~(bm_word_t)0) {
229 // find the position of the 0-bit
230 for (; res & 1; res_offset++) {
231 res = res >> 1;
232 }
233 assert(res_offset >= l_offset, "just checking");
234 return MIN2(res_offset, r_offset);
235 }
236 // skip over all word length 1-bit runs
237 for (index++; index < r_index; index++) {
238 res = map(index);
239 if (res != ~(bm_word_t)0) {
240 // found a 0, return the offset
241 for (res_offset = index << LogBitsPerWord; res & 1;
242 res_offset++) {
243 res = res >> 1;
244 }
245 assert(!(res & 1), "tautology; see loop condition");
246 assert(res_offset >= l_offset, "just checking");
247 return MIN2(res_offset, r_offset);
248 }
249 }
250 return r_offset;
251 }
252
253 inline BitMap::idx_t
254 BitMap::get_next_one_offset_aligned_right(idx_t l_offset, idx_t r_offset) const
255 {
256 verify_range(l_offset, r_offset);
257 assert(bit_in_word(r_offset) == 0, "r_offset not word-aligned");
258
259 if (l_offset == r_offset) {
260 return l_offset;
261 }
262 idx_t index = word_index(l_offset);
263 idx_t r_index = word_index(r_offset);
264 idx_t res_offset = l_offset;
265
266 // check bits including and to the _left_ of offset's position
267 bm_word_t res = map(index) >> bit_in_word(res_offset);
268 if (res != 0) {
269 // find the position of the 1-bit
270 for (; !(res & 1); res_offset++) {
271 res = res >> 1;
272 }
273 assert(res_offset >= l_offset &&
274 res_offset < r_offset, "just checking");
275 return res_offset;
276 }
277 // skip over all word length 0-bit runs
278 for (index++; index < r_index; index++) {
279 res = map(index);
280 if (res != 0) {
281 // found a 1, return the offset
282 for (res_offset = bit_index(index); !(res & 1); res_offset++) {
283 res = res >> 1;
284 }
285 assert(res & 1, "tautology; see loop condition");
286 assert(res_offset >= l_offset && res_offset < r_offset, "just checking");
287 return res_offset;
288 }
289 }
290 return r_offset;
291 }
292
293
294 // Returns a bit mask for a range of bits [beg, end) within a single word. Each
295 // bit in the mask is 0 if the bit is in the range, 1 if not in the range. The
296 // returned mask can be used directly to clear the range, or inverted to set the
297 // range. Note: end must not be 0.
298 inline BitMap::bm_word_t
299 BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const {
300 assert(end != 0, "does not work when end == 0");
301 assert(beg == end || word_index(beg) == word_index(end - 1),
302 "must be a single-word range");
303 bm_word_t mask = bit_mask(beg) - 1; // low (right) bits
304 if (bit_in_word(end) != 0) {
305 mask |= ~(bit_mask(end) - 1); // high (left) bits
306 }
307 return mask;
308 }
309
310 inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) {
311 memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(bm_word_t));
312 }
313
314 inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) {
315 memset(_map + beg, 0, (end - beg) * sizeof(bm_word_t));
316 }
317
318 inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const {
319 idx_t bit_rounded_up = bit + (BitsPerWord - 1);
320 // Check for integer arithmetic overflow.
321 return bit_rounded_up > bit ? word_index(bit_rounded_up) : size_in_words();
322 }
323
324 inline bool BitMap2D::is_valid_index(idx_t slot_index, idx_t bit_within_slot_index) {
325 verify_bit_within_slot_index(bit_within_slot_index);
326 return (bit_index(slot_index, bit_within_slot_index) < size_in_bits());
327 }
328
329 inline bool BitMap2D::at(idx_t slot_index, idx_t bit_within_slot_index) const {
330 verify_bit_within_slot_index(bit_within_slot_index);
331 return _map.at(bit_index(slot_index, bit_within_slot_index));
332 }
333
334 inline void BitMap2D::set_bit(idx_t slot_index, idx_t bit_within_slot_index) {
335 verify_bit_within_slot_index(bit_within_slot_index);
336 _map.set_bit(bit_index(slot_index, bit_within_slot_index));
337 }
338
339 inline void BitMap2D::clear_bit(idx_t slot_index, idx_t bit_within_slot_index) {
340 verify_bit_within_slot_index(bit_within_slot_index);
341 _map.clear_bit(bit_index(slot_index, bit_within_slot_index));
342 }
343
344 inline void BitMap2D::at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
345 verify_bit_within_slot_index(bit_within_slot_index);
346 _map.at_put(bit_index(slot_index, bit_within_slot_index), value);
347 }
348
349 inline void BitMap2D::at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
350 verify_bit_within_slot_index(bit_within_slot_index);
351
352 idx_t bit = bit_index(slot_index, bit_within_slot_index);
353 if (bit >= _map.size()) {
354 _map.resize(2 * MAX2(_map.size(), bit));
355 }
356 _map.at_put(bit, value);
357 }
358
359 #endif // SHARE_VM_UTILITIES_BITMAP_INLINE_HPP