Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/utilities/bitMap.inline.hpp
src/share/vm/utilities/bitMap.inline.hpp
- changeset 3454
- 2e966d967c5c
- parent 2314
- f95d63e2154a
- child 5713
- 17deed6716af
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| 3417:9d4f4a1825e4 | 3454:2e966d967c5c |
|---|---|
| 1 /* | 1 /* |
| 2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. | 2 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. |
| 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | 4 * |
| 5 * This code is free software; you can redistribute it and/or modify it | 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 | 6 * under the terms of the GNU General Public License version 2 only, as |
| 7 * published by the Free Software Foundation. | 7 * published by the Free Software Foundation. |
| 176 if (res != (uintptr_t)NoBits) { | 176 if (res != (uintptr_t)NoBits) { |
| 177 // find the position of the 1-bit | 177 // find the position of the 1-bit |
| 178 for (; !(res & 1); res_offset++) { | 178 for (; !(res & 1); res_offset++) { |
| 179 res = res >> 1; | 179 res = res >> 1; |
| 180 } | 180 } |
| 181 assert(res_offset >= l_offset && | 181 |
| 182 res_offset < r_offset, "just checking"); | 182 #ifdef ASSERT |
| 183 // In the following assert, if r_offset is not bitamp word aligned, | |
| 184 // checking that res_offset is strictly less than r_offset is too | |
| 185 // strong and will trip the assert. | |
| 186 // | |
| 187 // Consider the case where l_offset is bit 15 and r_offset is bit 17 | |
| 188 // of the same map word, and where bits [15:16:17:18] == [00:00:00:01]. | |
| 189 // All the bits in the range [l_offset:r_offset) are 0. | |
| 190 // The loop that calculates res_offset, above, would yield the offset | |
| 191 // of bit 18 because it's in the same map word as l_offset and there | |
| 192 // is a set bit in that map word above l_offset (i.e. res != NoBits). | |
| 193 // | |
| 194 // In this case, however, we can assert is that res_offset is strictly | |
| 195 // less than size() since we know that there is at least one set bit | |
| 196 // at an offset above, but in the same map word as, r_offset. | |
| 197 // Otherwise, if r_offset is word aligned then it will not be in the | |
| 198 // same map word as l_offset (unless it equals l_offset). So either | |
| 199 // there won't be a set bit between l_offset and the end of it's map | |
| 200 // word (i.e. res == NoBits), or res_offset will be less than r_offset. | |
| 201 | |
| 202 idx_t limit = is_word_aligned(r_offset) ? r_offset : size(); | |
| 203 assert(res_offset >= l_offset && res_offset < limit, "just checking"); | |
| 204 #endif // ASSERT | |
| 183 return MIN2(res_offset, r_offset); | 205 return MIN2(res_offset, r_offset); |
| 184 } | 206 } |
| 185 // skip over all word length 0-bit runs | 207 // skip over all word length 0-bit runs |
| 186 for (index++; index < r_index; index++) { | 208 for (index++; index < r_index; index++) { |
| 187 res = map(index); | 209 res = map(index); |
