| /* |
| * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "runtime/atomic.hpp" |
| #include "utilities/bitMap.inline.hpp" |
| #include "utilities/copy.hpp" |
| #include "utilities/debug.hpp" |
| |
| STATIC_ASSERT(sizeof(BitMap::bm_word_t) == BytesPerWord); // "Implementation assumption." |
| |
| typedef BitMap::bm_word_t bm_word_t; |
| typedef BitMap::idx_t idx_t; |
| |
| class ResourceBitMapAllocator : StackObj { |
| public: |
| bm_word_t* allocate(idx_t size_in_words) const { |
| return NEW_RESOURCE_ARRAY(bm_word_t, size_in_words); |
| } |
| void free(bm_word_t* map, idx_t size_in_words) const { |
| // Don't free resource allocated arrays. |
| } |
| }; |
| |
| class CHeapBitMapAllocator : StackObj { |
| MEMFLAGS _flags; |
| |
| public: |
| CHeapBitMapAllocator(MEMFLAGS flags) : _flags(flags) {} |
| bm_word_t* allocate(size_t size_in_words) const { |
| return ArrayAllocator<bm_word_t>::allocate(size_in_words, _flags); |
| } |
| void free(bm_word_t* map, idx_t size_in_words) const { |
| ArrayAllocator<bm_word_t>::free(map, size_in_words); |
| } |
| }; |
| |
| class ArenaBitMapAllocator : StackObj { |
| Arena* _arena; |
| |
| public: |
| ArenaBitMapAllocator(Arena* arena) : _arena(arena) {} |
| bm_word_t* allocate(idx_t size_in_words) const { |
| return (bm_word_t*)_arena->Amalloc(size_in_words * BytesPerWord); |
| } |
| void free(bm_word_t* map, idx_t size_in_words) const { |
| // ArenaBitMaps currently don't free memory. |
| } |
| }; |
| |
| template <class Allocator> |
| 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) { |
| size_t old_size_in_words = calc_size_in_words(old_size_in_bits); |
| size_t new_size_in_words = calc_size_in_words(new_size_in_bits); |
| |
| bm_word_t* map = NULL; |
| |
| if (new_size_in_words > 0) { |
| map = allocator.allocate(new_size_in_words); |
| |
| Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) map, |
| MIN2(old_size_in_words, new_size_in_words)); |
| |
| if (new_size_in_words > old_size_in_words) { |
| clear_range_of_words(map, old_size_in_words, new_size_in_words); |
| } |
| } |
| |
| if (old_map != NULL) { |
| allocator.free(old_map, old_size_in_words); |
| } |
| |
| return map; |
| } |
| |
| template <class Allocator> |
| bm_word_t* BitMap::allocate(const Allocator& allocator, idx_t size_in_bits) { |
| // Reuse reallocate to ensure that the new memory is cleared. |
| return reallocate(allocator, NULL, 0, size_in_bits); |
| } |
| |
| template <class Allocator> |
| void BitMap::free(const Allocator& allocator, bm_word_t* map, idx_t size_in_bits) { |
| bm_word_t* ret = reallocate(allocator, map, size_in_bits, 0); |
| assert(ret == NULL, "Reallocate shouldn't have allocated"); |
| } |
| |
| template <class Allocator> |
| void BitMap::resize(const Allocator& allocator, idx_t new_size_in_bits) { |
| bm_word_t* new_map = reallocate(allocator, map(), size(), new_size_in_bits); |
| |
| update(new_map, new_size_in_bits); |
| } |
| |
| template <class Allocator> |
| void BitMap::initialize(const Allocator& allocator, idx_t size_in_bits) { |
| assert(map() == NULL, "precondition"); |
| assert(size() == 0, "precondition"); |
| |
| resize(allocator, size_in_bits); |
| } |
| |
| template <class Allocator> |
| void BitMap::reinitialize(const Allocator& allocator, idx_t new_size_in_bits) { |
| // Remove previous bits. |
| resize(allocator, 0); |
| |
| initialize(allocator, new_size_in_bits); |
| } |
| |
| ResourceBitMap::ResourceBitMap(idx_t size_in_bits) |
| : BitMap(allocate(ResourceBitMapAllocator(), size_in_bits), size_in_bits) { |
| } |
| |
| void ResourceBitMap::resize(idx_t new_size_in_bits) { |
| BitMap::resize(ResourceBitMapAllocator(), new_size_in_bits); |
| } |
| |
| void ResourceBitMap::initialize(idx_t size_in_bits) { |
| BitMap::initialize(ResourceBitMapAllocator(), size_in_bits); |
| } |
| |
| void ResourceBitMap::reinitialize(idx_t size_in_bits) { |
| BitMap::reinitialize(ResourceBitMapAllocator(), size_in_bits); |
| } |
| |
| ArenaBitMap::ArenaBitMap(Arena* arena, idx_t size_in_bits) |
| : BitMap(allocate(ArenaBitMapAllocator(arena), size_in_bits), size_in_bits) { |
| } |
| |
| CHeapBitMap::CHeapBitMap(idx_t size_in_bits, MEMFLAGS flags) |
| : BitMap(allocate(CHeapBitMapAllocator(flags), size_in_bits), size_in_bits), _flags(flags) { |
| } |
| |
| CHeapBitMap::~CHeapBitMap() { |
| free(CHeapBitMapAllocator(_flags), map(), size()); |
| } |
| |
| void CHeapBitMap::resize(idx_t new_size_in_bits) { |
| BitMap::resize(CHeapBitMapAllocator(_flags), new_size_in_bits); |
| } |
| |
| void CHeapBitMap::initialize(idx_t size_in_bits) { |
| BitMap::initialize(CHeapBitMapAllocator(_flags), size_in_bits); |
| } |
| |
| void CHeapBitMap::reinitialize(idx_t size_in_bits) { |
| BitMap::reinitialize(CHeapBitMapAllocator(_flags), size_in_bits); |
| } |
| |
| #ifdef ASSERT |
| void BitMap::verify_index(idx_t index) const { |
| assert(index < _size, "BitMap index out of bounds"); |
| } |
| |
| void BitMap::verify_range(idx_t beg_index, idx_t end_index) const { |
| assert(beg_index <= end_index, "BitMap range error"); |
| // Note that [0,0) and [size,size) are both valid ranges. |
| if (end_index != _size) verify_index(end_index); |
| } |
| #endif // #ifdef ASSERT |
| |
| void BitMap::pretouch() { |
| os::pretouch_memory(word_addr(0), word_addr(size())); |
| } |
| |
| void BitMap::set_range_within_word(idx_t beg, idx_t end) { |
| // With a valid range (beg <= end), this test ensures that end != 0, as |
| // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. |
| if (beg != end) { |
| bm_word_t mask = inverted_bit_mask_for_range(beg, end); |
| *word_addr(beg) |= ~mask; |
| } |
| } |
| |
| void BitMap::clear_range_within_word(idx_t beg, idx_t end) { |
| // With a valid range (beg <= end), this test ensures that end != 0, as |
| // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. |
| if (beg != end) { |
| bm_word_t mask = inverted_bit_mask_for_range(beg, end); |
| *word_addr(beg) &= mask; |
| } |
| } |
| |
| void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) { |
| assert(value == 0 || value == 1, "0 for clear, 1 for set"); |
| // With a valid range (beg <= end), this test ensures that end != 0, as |
| // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. |
| if (beg != end) { |
| bm_word_t* pw = word_addr(beg); |
| bm_word_t w = *pw; |
| bm_word_t mr = inverted_bit_mask_for_range(beg, end); |
| bm_word_t nw = value ? (w | ~mr) : (w & mr); |
| while (true) { |
| bm_word_t res = Atomic::cmpxchg(nw, pw, w); |
| if (res == w) break; |
| w = res; |
| nw = value ? (w | ~mr) : (w & mr); |
| } |
| } |
| } |
| |
| void BitMap::set_range(idx_t beg, idx_t end) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| if (beg_full_word < end_full_word) { |
| // The range includes at least one full word. |
| set_range_within_word(beg, bit_index(beg_full_word)); |
| set_range_of_words(beg_full_word, end_full_word); |
| set_range_within_word(bit_index(end_full_word), end); |
| } else { |
| // The range spans at most 2 partial words. |
| idx_t boundary = MIN2(bit_index(beg_full_word), end); |
| set_range_within_word(beg, boundary); |
| set_range_within_word(boundary, end); |
| } |
| } |
| |
| void BitMap::clear_range(idx_t beg, idx_t end) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| if (beg_full_word < end_full_word) { |
| // The range includes at least one full word. |
| clear_range_within_word(beg, bit_index(beg_full_word)); |
| clear_range_of_words(beg_full_word, end_full_word); |
| clear_range_within_word(bit_index(end_full_word), end); |
| } else { |
| // The range spans at most 2 partial words. |
| idx_t boundary = MIN2(bit_index(beg_full_word), end); |
| clear_range_within_word(beg, boundary); |
| clear_range_within_word(boundary, end); |
| } |
| } |
| |
| void BitMap::set_large_range(idx_t beg, idx_t end) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| assert(end_full_word - beg_full_word >= 32, |
| "the range must include at least 32 bytes"); |
| |
| // The range includes at least one full word. |
| set_range_within_word(beg, bit_index(beg_full_word)); |
| set_large_range_of_words(beg_full_word, end_full_word); |
| set_range_within_word(bit_index(end_full_word), end); |
| } |
| |
| void BitMap::clear_large_range(idx_t beg, idx_t end) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| if (end_full_word - beg_full_word < 32) { |
| clear_range(beg, end); |
| return; |
| } |
| |
| // The range includes at least one full word. |
| clear_range_within_word(beg, bit_index(beg_full_word)); |
| clear_large_range_of_words(beg_full_word, end_full_word); |
| clear_range_within_word(bit_index(end_full_word), end); |
| } |
| |
| void BitMap::at_put(idx_t offset, bool value) { |
| if (value) { |
| set_bit(offset); |
| } else { |
| clear_bit(offset); |
| } |
| } |
| |
| // Return true to indicate that this thread changed |
| // the bit, false to indicate that someone else did. |
| // In either case, the requested bit is in the |
| // requested state some time during the period that |
| // this thread is executing this call. More importantly, |
| // if no other thread is executing an action to |
| // change the requested bit to a state other than |
| // the one that this thread is trying to set it to, |
| // then the the bit is in the expected state |
| // at exit from this method. However, rather than |
| // make such a strong assertion here, based on |
| // assuming such constrained use (which though true |
| // today, could change in the future to service some |
| // funky parallel algorithm), we encourage callers |
| // to do such verification, as and when appropriate. |
| bool BitMap::par_at_put(idx_t bit, bool value) { |
| return value ? par_set_bit(bit) : par_clear_bit(bit); |
| } |
| |
| void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) { |
| if (value) { |
| set_range(start_offset, end_offset); |
| } else { |
| clear_range(start_offset, end_offset); |
| } |
| } |
| |
| void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| if (beg_full_word < end_full_word) { |
| // The range includes at least one full word. |
| par_put_range_within_word(beg, bit_index(beg_full_word), value); |
| if (value) { |
| set_range_of_words(beg_full_word, end_full_word); |
| } else { |
| clear_range_of_words(beg_full_word, end_full_word); |
| } |
| par_put_range_within_word(bit_index(end_full_word), end, value); |
| } else { |
| // The range spans at most 2 partial words. |
| idx_t boundary = MIN2(bit_index(beg_full_word), end); |
| par_put_range_within_word(beg, boundary, value); |
| par_put_range_within_word(boundary, end, value); |
| } |
| |
| } |
| |
| void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) { |
| if (value) { |
| set_large_range(beg, end); |
| } else { |
| clear_large_range(beg, end); |
| } |
| } |
| |
| void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) { |
| verify_range(beg, end); |
| |
| idx_t beg_full_word = word_index_round_up(beg); |
| idx_t end_full_word = word_index(end); |
| |
| assert(end_full_word - beg_full_word >= 32, |
| "the range must include at least 32 bytes"); |
| |
| // The range includes at least one full word. |
| par_put_range_within_word(beg, bit_index(beg_full_word), value); |
| if (value) { |
| set_large_range_of_words(beg_full_word, end_full_word); |
| } else { |
| clear_large_range_of_words(beg_full_word, end_full_word); |
| } |
| par_put_range_within_word(bit_index(end_full_word), end, value); |
| } |
| |
| inline bm_word_t tail_mask(idx_t tail_bits) { |
| assert(tail_bits != 0, "precondition"); // Works, but shouldn't be called. |
| assert(tail_bits < (idx_t)BitsPerWord, "precondition"); |
| return (bm_word_t(1) << tail_bits) - 1; |
| } |
| |
| // Get the low tail_bits of value, which is the last partial word of a map. |
| inline bm_word_t tail_of_map(bm_word_t value, idx_t tail_bits) { |
| return value & tail_mask(tail_bits); |
| } |
| |
| // Compute the new last word of a map with a non-aligned length. |
| // new_value has the new trailing bits of the map in the low tail_bits. |
| // old_value is the last word of the map, including bits beyond the end. |
| // Returns old_value with the low tail_bits replaced by the corresponding |
| // bits in new_value. |
| inline bm_word_t merge_tail_of_map(bm_word_t new_value, |
| bm_word_t old_value, |
| idx_t tail_bits) { |
| bm_word_t mask = tail_mask(tail_bits); |
| return (new_value & mask) | (old_value & ~mask); |
| } |
| |
| bool BitMap::contains(const BitMap& other) const { |
| assert(size() == other.size(), "must have same size"); |
| const bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| // false if other bitmap has bits set which are clear in this bitmap. |
| if ((~dest_map[index] & other_map[index]) != 0) return false; |
| } |
| idx_t rest = bit_in_word(size()); |
| // true unless there is a partial-word tail in which the other |
| // bitmap has bits set which are clear in this bitmap. |
| return (rest == 0) || tail_of_map(~dest_map[limit] & other_map[limit], rest) == 0; |
| } |
| |
| bool BitMap::intersects(const BitMap& other) const { |
| assert(size() == other.size(), "must have same size"); |
| const bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| if ((dest_map[index] & other_map[index]) != 0) return true; |
| } |
| idx_t rest = bit_in_word(size()); |
| // false unless there is a partial-word tail with non-empty intersection. |
| return (rest > 0) && tail_of_map(dest_map[limit] & other_map[limit], rest) != 0; |
| } |
| |
| void BitMap::set_union(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| dest_map[index] |= other_map[index]; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| dest_map[limit] = merge_tail_of_map(orig | other_map[limit], orig, rest); |
| } |
| } |
| |
| void BitMap::set_difference(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| dest_map[index] &= ~other_map[index]; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| dest_map[limit] = merge_tail_of_map(orig & ~other_map[limit], orig, rest); |
| } |
| } |
| |
| void BitMap::set_intersection(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| dest_map[index] &= other_map[index]; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| dest_map[limit] = merge_tail_of_map(orig & other_map[limit], orig, rest); |
| } |
| } |
| |
| bool BitMap::set_union_with_result(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bool changed = false; |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| bm_word_t orig = dest_map[index]; |
| bm_word_t temp = orig | other_map[index]; |
| changed = changed || (temp != orig); |
| dest_map[index] = temp; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| bm_word_t temp = merge_tail_of_map(orig | other_map[limit], orig, rest); |
| changed = changed || (temp != orig); |
| dest_map[limit] = temp; |
| } |
| return changed; |
| } |
| |
| bool BitMap::set_difference_with_result(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bool changed = false; |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| bm_word_t orig = dest_map[index]; |
| bm_word_t temp = orig & ~other_map[index]; |
| changed = changed || (temp != orig); |
| dest_map[index] = temp; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| bm_word_t temp = merge_tail_of_map(orig & ~other_map[limit], orig, rest); |
| changed = changed || (temp != orig); |
| dest_map[limit] = temp; |
| } |
| return changed; |
| } |
| |
| bool BitMap::set_intersection_with_result(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bool changed = false; |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| bm_word_t orig = dest_map[index]; |
| bm_word_t temp = orig & other_map[index]; |
| changed = changed || (temp != orig); |
| dest_map[index] = temp; |
| } |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| bm_word_t orig = dest_map[limit]; |
| bm_word_t temp = merge_tail_of_map(orig & other_map[limit], orig, rest); |
| changed = changed || (temp != orig); |
| dest_map[limit] = temp; |
| } |
| return changed; |
| } |
| |
| void BitMap::set_from(const BitMap& other) { |
| assert(size() == other.size(), "must have same size"); |
| bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t copy_words = word_index(size()); |
| Copy::disjoint_words((HeapWord*)other_map, (HeapWord*)dest_map, copy_words); |
| idx_t rest = bit_in_word(size()); |
| if (rest > 0) { |
| dest_map[copy_words] = merge_tail_of_map(other_map[copy_words], |
| dest_map[copy_words], |
| rest); |
| } |
| } |
| |
| bool BitMap::is_same(const BitMap& other) const { |
| assert(size() == other.size(), "must have same size"); |
| const bm_word_t* dest_map = map(); |
| const bm_word_t* other_map = other.map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| if (dest_map[index] != other_map[index]) return false; |
| } |
| idx_t rest = bit_in_word(size()); |
| return (rest == 0) || (tail_of_map(dest_map[limit] ^ other_map[limit], rest) == 0); |
| } |
| |
| bool BitMap::is_full() const { |
| const bm_word_t* words = map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| if (~words[index] != 0) return false; |
| } |
| idx_t rest = bit_in_word(size()); |
| return (rest == 0) || (tail_of_map(~words[limit], rest) == 0); |
| } |
| |
| bool BitMap::is_empty() const { |
| const bm_word_t* words = map(); |
| idx_t limit = word_index(size()); |
| for (idx_t index = 0; index < limit; ++index) { |
| if (words[index] != 0) return false; |
| } |
| idx_t rest = bit_in_word(size()); |
| return (rest == 0) || (tail_of_map(words[limit], rest) == 0); |
| } |
| |
| void BitMap::clear_large() { |
| clear_large_range_of_words(0, size_in_words()); |
| } |
| |
| // Note that if the closure itself modifies the bitmap |
| // then modifications in and to the left of the _bit_ being |
| // currently sampled will not be seen. Note also that the |
| // interval [leftOffset, rightOffset) is right open. |
| bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) { |
| verify_range(leftOffset, rightOffset); |
| |
| idx_t startIndex = word_index(leftOffset); |
| idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words()); |
| for (idx_t index = startIndex, offset = leftOffset; |
| offset < rightOffset && index < endIndex; |
| offset = (++index) << LogBitsPerWord) { |
| idx_t rest = map(index) >> (offset & (BitsPerWord - 1)); |
| for (; offset < rightOffset && rest != 0; offset++) { |
| if (rest & 1) { |
| if (!blk->do_bit(offset)) return false; |
| // resample at each closure application |
| // (see, for instance, CMS bug 4525989) |
| rest = map(index) >> (offset & (BitsPerWord -1)); |
| } |
| rest = rest >> 1; |
| } |
| } |
| return true; |
| } |
| |
| const BitMap::idx_t* BitMap::_pop_count_table = NULL; |
| |
| void BitMap::init_pop_count_table() { |
| if (_pop_count_table == NULL) { |
| BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal); |
| for (uint i = 0; i < 256; i++) { |
| table[i] = num_set_bits(i); |
| } |
| |
| if (!Atomic::replace_if_null(table, &_pop_count_table)) { |
| guarantee(_pop_count_table != NULL, "invariant"); |
| FREE_C_HEAP_ARRAY(idx_t, table); |
| } |
| } |
| } |
| |
| BitMap::idx_t BitMap::num_set_bits(bm_word_t w) { |
| idx_t bits = 0; |
| |
| while (w != 0) { |
| while ((w & 1) == 0) { |
| w >>= 1; |
| } |
| bits++; |
| w >>= 1; |
| } |
| return bits; |
| } |
| |
| BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) { |
| assert(_pop_count_table != NULL, "precondition"); |
| return _pop_count_table[c]; |
| } |
| |
| BitMap::idx_t BitMap::count_one_bits() const { |
| init_pop_count_table(); // If necessary. |
| idx_t sum = 0; |
| typedef unsigned char uchar; |
| for (idx_t i = 0; i < size_in_words(); i++) { |
| bm_word_t w = map()[i]; |
| for (size_t j = 0; j < sizeof(bm_word_t); j++) { |
| sum += num_set_bits_from_table(uchar(w & 255)); |
| w >>= 8; |
| } |
| } |
| return sum; |
| } |
| |
| void BitMap::print_on_error(outputStream* st, const char* prefix) const { |
| st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")", |
| prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte))); |
| } |
| |
| #ifndef PRODUCT |
| |
| void BitMap::print_on(outputStream* st) const { |
| tty->print("Bitmap(" SIZE_FORMAT "):", size()); |
| for (idx_t index = 0; index < size(); index++) { |
| tty->print("%c", at(index) ? '1' : '0'); |
| } |
| tty->cr(); |
| } |
| |
| #endif |