1 /* 2 * Copyright (c) 2005, 2010, 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 #ifdef ASSERT 32 inline void BitMap::verify_index(idx_t index) const { 33 assert(index < _size, "BitMap index out of bounds"); 34 } 35 36 inline void BitMap::verify_range(idx_t beg_index, idx_t end_index) const { 37 assert(beg_index <= end_index, "BitMap range error"); 38 // Note that [0,0) and [size,size) are both valid ranges. 39 if (end_index != _size) verify_index(end_index); 40 } 41 #endif // #ifdef ASSERT 42 43 inline void BitMap::set_bit(idx_t bit) { 44 verify_index(bit); 45 *word_addr(bit) |= bit_mask(bit); 46 } 47 48 inline void BitMap::clear_bit(idx_t bit) { 49 verify_index(bit); 50 *word_addr(bit) &= ~bit_mask(bit); 51 } 52 53 inline bool BitMap::par_set_bit(idx_t bit) { 54 verify_index(bit); 55 volatile idx_t* const addr = word_addr(bit); 56 const idx_t mask = bit_mask(bit); 57 idx_t old_val = *addr; 58 59 do { 60 const idx_t new_val = old_val | mask; 61 if (new_val == old_val) { 62 return false; // Someone else beat us to it. 63 } 64 const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val, 65 (volatile void*) addr, 66 (void*) old_val); 67 if (cur_val == old_val) { 68 return true; // Success. 69 } 70 old_val = cur_val; // The value changed, try again. 71 } while (true); 72 } 73 74 inline bool BitMap::par_clear_bit(idx_t bit) { 75 verify_index(bit); 76 volatile idx_t* const addr = word_addr(bit); 77 const idx_t mask = ~bit_mask(bit); 78 idx_t old_val = *addr; 79 80 do { 81 const idx_t new_val = old_val & mask; 82 if (new_val == old_val) { 83 return false; // Someone else beat us to it. 84 } 85 const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val, 86 (volatile void*) addr, 87 (void*) old_val); 88 if (cur_val == old_val) { 89 return true; // Success. 90 } 91 old_val = cur_val; // The value changed, try again. 92 } while (true); 93 } 94 95 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) { 96 if (hint == small_range && end - beg == 1) { 97 set_bit(beg); 98 } else { 99 if (hint == large_range) { 100 set_large_range(beg, end); 101 } else { 102 set_range(beg, end); 103 } 104 } 105 } 106 107 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) { 108 if (hint == small_range && end - beg == 1) { 109 clear_bit(beg); 110 } else { 111 if (hint == large_range) { 112 clear_large_range(beg, end); 113 } else { 114 clear_range(beg, end); 115 } 116 } 117 } 118 119 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) { 120 if (hint == small_range && end - beg == 1) { 121 par_at_put(beg, true); 122 } else { 123 if (hint == large_range) { 124 par_at_put_large_range(beg, end, true); 125 } else { 126 par_at_put_range(beg, end, true); 127 } 128 } 129 } 130 131 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) { 132 bm_word_t* map = _map; 133 for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0; 134 } 135 136 137 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) { 138 bm_word_t* map = _map; 139 for (idx_t i = beg; i < end; ++i) map[i] = 0; 140 } 141 142 143 inline void BitMap::clear() { 144 clear_range_of_words(0, size_in_words()); 145 } 146 147 148 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) { 149 if (hint == small_range && end - beg == 1) { 150 par_at_put(beg, false); 151 } else { 152 if (hint == large_range) { 153 par_at_put_large_range(beg, end, false); 154 } else { 155 par_at_put_range(beg, end, false); 156 } 157 } 158 } 159 160 inline BitMap::idx_t 161 BitMap::get_next_one_offset_inline(idx_t l_offset, idx_t r_offset) const { 162 assert(l_offset <= size(), "BitMap index out of bounds"); 163 assert(r_offset <= size(), "BitMap index out of bounds"); 164 assert(l_offset <= r_offset, "l_offset > r_offset ?"); 165 166 if (l_offset == r_offset) { 167 return l_offset; 168 } 169 idx_t index = word_index(l_offset); 170 idx_t r_index = word_index(r_offset-1) + 1; 171 idx_t res_offset = l_offset; 172 173 // check bits including and to the _left_ of offset's position 174 idx_t pos = bit_in_word(res_offset); 175 idx_t res = map(index) >> pos; 176 if (res != (uintptr_t)NoBits) { 177 // find the position of the 1-bit 178 for (; !(res & 1); res_offset++) { 179 res = res >> 1; 180 } 181 182 // In the following assert, checking that res_offset is strictly 183 // less than r_offset is too strong. Consider the case where 184 // l_offset is bit 15 and r_offset is bit 17 of the same map word, 185 // and where bits [18:17:16:15] == [01:00:00:00]. The calculation 186 // above would yield the offset of bit 18. All we can assert is that 187 // res_offset is strictly less than size() since we know that there 188 // are set bits at offsets above, but in the same map word as, r_offset 189 // The bits in the range (r_offset:l_offset] are all 0. 190 assert(res_offset >= l_offset && res_offset < size(), "just checking"); 191 return MIN2(res_offset, r_offset); 192 } 193 // skip over all word length 0-bit runs 194 for (index++; index < r_index; index++) { 195 res = map(index); 196 if (res != (uintptr_t)NoBits) { 197 // found a 1, return the offset 198 for (res_offset = bit_index(index); !(res & 1); res_offset++) { 199 res = res >> 1; 200 } 201 assert(res & 1, "tautology; see loop condition"); 202 assert(res_offset >= l_offset, "just checking"); 203 return MIN2(res_offset, r_offset); 204 } 205 } 206 return r_offset; 207 } 208 209 inline BitMap::idx_t 210 BitMap::get_next_zero_offset_inline(idx_t l_offset, idx_t r_offset) const { 211 assert(l_offset <= size(), "BitMap index out of bounds"); 212 assert(r_offset <= size(), "BitMap index out of bounds"); 213 assert(l_offset <= r_offset, "l_offset > r_offset ?"); 214 215 if (l_offset == r_offset) { 216 return l_offset; 217 } 218 idx_t index = word_index(l_offset); 219 idx_t r_index = word_index(r_offset-1) + 1; 220 idx_t res_offset = l_offset; 221 222 // check bits including and to the _left_ of offset's position 223 idx_t pos = res_offset & (BitsPerWord - 1); 224 idx_t res = (map(index) >> pos) | left_n_bits((int)pos); 225 226 if (res != (uintptr_t)AllBits) { 227 // find the position of the 0-bit 228 for (; res & 1; res_offset++) { 229 res = res >> 1; 230 } 231 assert(res_offset >= l_offset, "just checking"); 232 return MIN2(res_offset, r_offset); 233 } 234 // skip over all word length 1-bit runs 235 for (index++; index < r_index; index++) { 236 res = map(index); 237 if (res != (uintptr_t)AllBits) { 238 // found a 0, return the offset 239 for (res_offset = index << LogBitsPerWord; res & 1; 240 res_offset++) { 241 res = res >> 1; 242 } 243 assert(!(res & 1), "tautology; see loop condition"); 244 assert(res_offset >= l_offset, "just checking"); 245 return MIN2(res_offset, r_offset); 246 } 247 } 248 return r_offset; 249 } 250 251 inline BitMap::idx_t 252 BitMap::get_next_one_offset_inline_aligned_right(idx_t l_offset, 253 idx_t r_offset) const 254 { 255 verify_range(l_offset, r_offset); 256 assert(bit_in_word(r_offset) == 0, "r_offset not word-aligned"); 257 258 if (l_offset == r_offset) { 259 return l_offset; 260 } 261 idx_t index = word_index(l_offset); 262 idx_t r_index = word_index(r_offset); 263 idx_t res_offset = l_offset; 264 265 // check bits including and to the _left_ of offset's position 266 idx_t res = map(index) >> bit_in_word(res_offset); 267 if (res != (uintptr_t)NoBits) { 268 // find the position of the 1-bit 269 for (; !(res & 1); res_offset++) { 270 res = res >> 1; 271 } 272 assert(res_offset >= l_offset && 273 res_offset < r_offset, "just checking"); 274 return res_offset; 275 } 276 // skip over all word length 0-bit runs 277 for (index++; index < r_index; index++) { 278 res = map(index); 279 if (res != (uintptr_t)NoBits) { 280 // found a 1, return the offset 281 for (res_offset = bit_index(index); !(res & 1); res_offset++) { 282 res = res >> 1; 283 } 284 assert(res & 1, "tautology; see loop condition"); 285 assert(res_offset >= l_offset && res_offset < r_offset, "just checking"); 286 return res_offset; 287 } 288 } 289 return r_offset; 290 } 291 292 293 // Returns a bit mask for a range of bits [beg, end) within a single word. Each 294 // bit in the mask is 0 if the bit is in the range, 1 if not in the range. The 295 // returned mask can be used directly to clear the range, or inverted to set the 296 // range. Note: end must not be 0. 297 inline BitMap::bm_word_t 298 BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const { 299 assert(end != 0, "does not work when end == 0"); 300 assert(beg == end || word_index(beg) == word_index(end - 1), 301 "must be a single-word range"); 302 bm_word_t mask = bit_mask(beg) - 1; // low (right) bits 303 if (bit_in_word(end) != 0) { 304 mask |= ~(bit_mask(end) - 1); // high (left) bits 305 } 306 return mask; 307 } 308 309 inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) { 310 memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(uintptr_t)); 311 } 312 313 inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) { 314 memset(_map + beg, 0, (end - beg) * sizeof(uintptr_t)); 315 } 316 317 inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const { 318 idx_t bit_rounded_up = bit + (BitsPerWord - 1); 319 // Check for integer arithmetic overflow. 320 return bit_rounded_up > bit ? word_index(bit_rounded_up) : size_in_words(); 321 } 322 323 inline BitMap::idx_t BitMap::get_next_one_offset(idx_t l_offset, 324 idx_t r_offset) const { 325 return get_next_one_offset_inline(l_offset, r_offset); 326 } 327 328 inline BitMap::idx_t BitMap::get_next_zero_offset(idx_t l_offset, 329 idx_t r_offset) const { 330 return get_next_zero_offset_inline(l_offset, r_offset); 331 } 332 333 inline void BitMap2D::clear() { 334 _map.clear(); 335 } 336 337 #endif // SHARE_VM_UTILITIES_BITMAP_INLINE_HPP