aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "memory/allocation.inline.hpp"
aoqi@0: #include "utilities/bitMap.inline.hpp"
aoqi@0: #include "utilities/copy.hpp"
aoqi@0: #ifdef TARGET_OS_FAMILY_linux
aoqi@0: # include "os_linux.inline.hpp"
aoqi@0: #endif
aoqi@0: #ifdef TARGET_OS_FAMILY_solaris
aoqi@0: # include "os_solaris.inline.hpp"
aoqi@0: #endif
aoqi@0: #ifdef TARGET_OS_FAMILY_windows
aoqi@0: # include "os_windows.inline.hpp"
aoqi@0: #endif
aoqi@0: #ifdef TARGET_OS_FAMILY_aix
aoqi@0: # include "os_aix.inline.hpp"
aoqi@0: #endif
aoqi@0: #ifdef TARGET_OS_FAMILY_bsd
aoqi@0: # include "os_bsd.inline.hpp"
aoqi@0: #endif
aoqi@0: 
aoqi@0: 
aoqi@0: BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
aoqi@0:   _map(map), _size(size_in_bits), _map_allocator(false)
aoqi@0: {
aoqi@0:   assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
aoqi@0:   assert(size_in_bits >= 0, "just checking");
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
aoqi@0:   _map(NULL), _size(0), _map_allocator(false)
aoqi@0: {
aoqi@0:   assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
aoqi@0:   resize(size_in_bits, in_resource_area);
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
aoqi@0:   assert(size_in_bits >= 0, "just checking");
aoqi@0:   idx_t old_size_in_words = size_in_words();
aoqi@0:   bm_word_t* old_map = map();
aoqi@0: 
aoqi@0:   _size = size_in_bits;
aoqi@0:   idx_t new_size_in_words = size_in_words();
aoqi@0:   if (in_resource_area) {
aoqi@0:     _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
aoqi@0:   } else {
aoqi@0:     if (old_map != NULL) {
aoqi@0:       _map_allocator.free();
aoqi@0:     }
aoqi@0:     _map = _map_allocator.allocate(new_size_in_words);
aoqi@0:   }
aoqi@0:   Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
aoqi@0:                        MIN2(old_size_in_words, new_size_in_words));
aoqi@0:   if (new_size_in_words > old_size_in_words) {
aoqi@0:     clear_range_of_words(old_size_in_words, size_in_words());
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::set_range_within_word(idx_t beg, idx_t end) {
aoqi@0:   // With a valid range (beg <= end), this test ensures that end != 0, as
aoqi@0:   // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.
aoqi@0:   if (beg != end) {
aoqi@0:     bm_word_t mask = inverted_bit_mask_for_range(beg, end);
aoqi@0:     *word_addr(beg) |= ~mask;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
aoqi@0:   // With a valid range (beg <= end), this test ensures that end != 0, as
aoqi@0:   // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.
aoqi@0:   if (beg != end) {
aoqi@0:     bm_word_t mask = inverted_bit_mask_for_range(beg, end);
aoqi@0:     *word_addr(beg) &= mask;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
aoqi@0:   assert(value == 0 || value == 1, "0 for clear, 1 for set");
aoqi@0:   // With a valid range (beg <= end), this test ensures that end != 0, as
aoqi@0:   // required by inverted_bit_mask_for_range.  Also avoids an unnecessary write.
aoqi@0:   if (beg != end) {
aoqi@0:     intptr_t* pw  = (intptr_t*)word_addr(beg);
aoqi@0:     intptr_t  w   = *pw;
aoqi@0:     intptr_t  mr  = (intptr_t)inverted_bit_mask_for_range(beg, end);
aoqi@0:     intptr_t  nw  = value ? (w | ~mr) : (w & mr);
aoqi@0:     while (true) {
aoqi@0:       intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
aoqi@0:       if (res == w) break;
aoqi@0:       w  = res;
aoqi@0:       nw = value ? (w | ~mr) : (w & mr);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::set_range(idx_t beg, idx_t end) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   if (beg_full_word < end_full_word) {
aoqi@0:     // The range includes at least one full word.
aoqi@0:     set_range_within_word(beg, bit_index(beg_full_word));
aoqi@0:     set_range_of_words(beg_full_word, end_full_word);
aoqi@0:     set_range_within_word(bit_index(end_full_word), end);
aoqi@0:   } else {
aoqi@0:     // The range spans at most 2 partial words.
aoqi@0:     idx_t boundary = MIN2(bit_index(beg_full_word), end);
aoqi@0:     set_range_within_word(beg, boundary);
aoqi@0:     set_range_within_word(boundary, end);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::clear_range(idx_t beg, idx_t end) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   if (beg_full_word < end_full_word) {
aoqi@0:     // The range includes at least one full word.
aoqi@0:     clear_range_within_word(beg, bit_index(beg_full_word));
aoqi@0:     clear_range_of_words(beg_full_word, end_full_word);
aoqi@0:     clear_range_within_word(bit_index(end_full_word), end);
aoqi@0:   } else {
aoqi@0:     // The range spans at most 2 partial words.
aoqi@0:     idx_t boundary = MIN2(bit_index(beg_full_word), end);
aoqi@0:     clear_range_within_word(beg, boundary);
aoqi@0:     clear_range_within_word(boundary, end);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::set_large_range(idx_t beg, idx_t end) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   assert(end_full_word - beg_full_word >= 32,
aoqi@0:          "the range must include at least 32 bytes");
aoqi@0: 
aoqi@0:   // The range includes at least one full word.
aoqi@0:   set_range_within_word(beg, bit_index(beg_full_word));
aoqi@0:   set_large_range_of_words(beg_full_word, end_full_word);
aoqi@0:   set_range_within_word(bit_index(end_full_word), end);
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::clear_large_range(idx_t beg, idx_t end) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   assert(end_full_word - beg_full_word >= 32,
aoqi@0:          "the range must include at least 32 bytes");
aoqi@0: 
aoqi@0:   // The range includes at least one full word.
aoqi@0:   clear_range_within_word(beg, bit_index(beg_full_word));
aoqi@0:   clear_large_range_of_words(beg_full_word, end_full_word);
aoqi@0:   clear_range_within_word(bit_index(end_full_word), end);
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::at_put(idx_t offset, bool value) {
aoqi@0:   if (value) {
aoqi@0:     set_bit(offset);
aoqi@0:   } else {
aoqi@0:     clear_bit(offset);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Return true to indicate that this thread changed
aoqi@0: // the bit, false to indicate that someone else did.
aoqi@0: // In either case, the requested bit is in the
aoqi@0: // requested state some time during the period that
aoqi@0: // this thread is executing this call. More importantly,
aoqi@0: // if no other thread is executing an action to
aoqi@0: // change the requested bit to a state other than
aoqi@0: // the one that this thread is trying to set it to,
aoqi@0: // then the the bit is in the expected state
aoqi@0: // at exit from this method. However, rather than
aoqi@0: // make such a strong assertion here, based on
aoqi@0: // assuming such constrained use (which though true
aoqi@0: // today, could change in the future to service some
aoqi@0: // funky parallel algorithm), we encourage callers
aoqi@0: // to do such verification, as and when appropriate.
aoqi@0: bool BitMap::par_at_put(idx_t bit, bool value) {
aoqi@0:   return value ? par_set_bit(bit) : par_clear_bit(bit);
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::at_put_grow(idx_t offset, bool value) {
aoqi@0:   if (offset >= size()) {
aoqi@0:     resize(2 * MAX2(size(), offset));
aoqi@0:   }
aoqi@0:   at_put(offset, value);
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
aoqi@0:   if (value) {
aoqi@0:     set_range(start_offset, end_offset);
aoqi@0:   } else {
aoqi@0:     clear_range(start_offset, end_offset);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   if (beg_full_word < end_full_word) {
aoqi@0:     // The range includes at least one full word.
aoqi@0:     par_put_range_within_word(beg, bit_index(beg_full_word), value);
aoqi@0:     if (value) {
aoqi@0:       set_range_of_words(beg_full_word, end_full_word);
aoqi@0:     } else {
aoqi@0:       clear_range_of_words(beg_full_word, end_full_word);
aoqi@0:     }
aoqi@0:     par_put_range_within_word(bit_index(end_full_word), end, value);
aoqi@0:   } else {
aoqi@0:     // The range spans at most 2 partial words.
aoqi@0:     idx_t boundary = MIN2(bit_index(beg_full_word), end);
aoqi@0:     par_put_range_within_word(beg, boundary, value);
aoqi@0:     par_put_range_within_word(boundary, end, value);
aoqi@0:   }
aoqi@0: 
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
aoqi@0:   if (value) {
aoqi@0:     set_large_range(beg, end);
aoqi@0:   } else {
aoqi@0:     clear_large_range(beg, end);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
aoqi@0:   verify_range(beg, end);
aoqi@0: 
aoqi@0:   idx_t beg_full_word = word_index_round_up(beg);
aoqi@0:   idx_t end_full_word = word_index(end);
aoqi@0: 
aoqi@0:   assert(end_full_word - beg_full_word >= 32,
aoqi@0:          "the range must include at least 32 bytes");
aoqi@0: 
aoqi@0:   // The range includes at least one full word.
aoqi@0:   par_put_range_within_word(beg, bit_index(beg_full_word), value);
aoqi@0:   if (value) {
aoqi@0:     set_large_range_of_words(beg_full_word, end_full_word);
aoqi@0:   } else {
aoqi@0:     clear_large_range_of_words(beg_full_word, end_full_word);
aoqi@0:   }
aoqi@0:   par_put_range_within_word(bit_index(end_full_word), end, value);
aoqi@0: }
aoqi@0: 
aoqi@0: bool BitMap::contains(const BitMap other) const {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size_in_words(); index++) {
aoqi@0:     bm_word_t word_union = dest_map[index] | other_map[index];
aoqi@0:     // If this has more bits set than dest_map[index], then other is not a
aoqi@0:     // subset.
aoqi@0:     if (word_union != dest_map[index]) return false;
aoqi@0:   }
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: bool BitMap::intersects(const BitMap other) const {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size_in_words(); index++) {
aoqi@0:     if ((dest_map[index] & other_map[index]) != 0) return true;
aoqi@0:   }
aoqi@0:   // Otherwise, no intersection.
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::set_union(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size_in_words(); index++) {
aoqi@0:     dest_map[index] = dest_map[index] | other_map[index];
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void BitMap::set_difference(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size_in_words(); index++) {
aoqi@0:     dest_map[index] = dest_map[index] & ~(other_map[index]);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void BitMap::set_intersection(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     dest_map[index]  = dest_map[index] & other_map[index];
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
aoqi@0:   assert(other.size() >= offset, "offset not in range");
aoqi@0:   assert(other.size() - offset >= size(), "other not large enough");
aoqi@0:   // XXX Ideally, we would remove this restriction.
aoqi@0:   guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
aoqi@0:             "Only handle aligned cases so far.");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t offset_word_ind = word_index(offset);
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: bool BitMap::set_union_with_result(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bool changed = false;
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     idx_t temp = map(index) | other_map[index];
aoqi@0:     changed = changed || (temp != map(index));
aoqi@0:     map()[index] = temp;
aoqi@0:   }
aoqi@0:   return changed;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool BitMap::set_difference_with_result(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bool changed = false;
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     bm_word_t temp = dest_map[index] & ~(other_map[index]);
aoqi@0:     changed = changed || (temp != dest_map[index]);
aoqi@0:     dest_map[index] = temp;
aoqi@0:   }
aoqi@0:   return changed;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool BitMap::set_intersection_with_result(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bool changed = false;
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     bm_word_t orig = dest_map[index];
aoqi@0:     bm_word_t temp = orig & other_map[index];
aoqi@0:     changed = changed || (temp != orig);
aoqi@0:     dest_map[index]  = temp;
aoqi@0:   }
aoqi@0:   return changed;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void BitMap::set_from(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     dest_map[index] = other_map[index];
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool BitMap::is_same(BitMap other) {
aoqi@0:   assert(size() == other.size(), "must have same size");
aoqi@0:   bm_word_t* dest_map = map();
aoqi@0:   bm_word_t* other_map = other.map();
aoqi@0:   idx_t size = size_in_words();
aoqi@0:   for (idx_t index = 0; index < size; index++) {
aoqi@0:     if (dest_map[index] != other_map[index]) return false;
aoqi@0:   }
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: bool BitMap::is_full() const {
aoqi@0:   bm_word_t* word = map();
aoqi@0:   idx_t rest = size();
aoqi@0:   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
aoqi@0:     if (*word != (bm_word_t) AllBits) return false;
aoqi@0:     word++;
aoqi@0:   }
aoqi@0:   return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool BitMap::is_empty() const {
aoqi@0:   bm_word_t* word = map();
aoqi@0:   idx_t rest = size();
aoqi@0:   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
aoqi@0:     if (*word != (bm_word_t) NoBits) return false;
aoqi@0:     word++;
aoqi@0:   }
aoqi@0:   return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::clear_large() {
aoqi@0:   clear_large_range_of_words(0, size_in_words());
aoqi@0: }
aoqi@0: 
aoqi@0: // Note that if the closure itself modifies the bitmap
aoqi@0: // then modifications in and to the left of the _bit_ being
aoqi@0: // currently sampled will not be seen. Note also that the
aoqi@0: // interval [leftOffset, rightOffset) is right open.
aoqi@0: bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
aoqi@0:   verify_range(leftOffset, rightOffset);
aoqi@0: 
aoqi@0:   idx_t startIndex = word_index(leftOffset);
aoqi@0:   idx_t endIndex   = MIN2(word_index(rightOffset) + 1, size_in_words());
aoqi@0:   for (idx_t index = startIndex, offset = leftOffset;
aoqi@0:        offset < rightOffset && index < endIndex;
aoqi@0:        offset = (++index) << LogBitsPerWord) {
aoqi@0:     idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
aoqi@0:     for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
aoqi@0:       if (rest & 1) {
aoqi@0:         if (!blk->do_bit(offset)) return false;
aoqi@0:         //  resample at each closure application
aoqi@0:         // (see, for instance, CMS bug 4525989)
aoqi@0:         rest = map(index) >> (offset & (BitsPerWord -1));
aoqi@0:       }
aoqi@0:       rest = rest >> 1;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: BitMap::idx_t* BitMap::_pop_count_table = NULL;
aoqi@0: 
aoqi@0: void BitMap::init_pop_count_table() {
aoqi@0:   if (_pop_count_table == NULL) {
aoqi@0:     BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
aoqi@0:     for (uint i = 0; i < 256; i++) {
aoqi@0:       table[i] = num_set_bits(i);
aoqi@0:     }
aoqi@0: 
aoqi@0:     intptr_t res = Atomic::cmpxchg_ptr((intptr_t)  table,
aoqi@0:                                        (intptr_t*) &_pop_count_table,
aoqi@0:                                        (intptr_t)  NULL_WORD);
aoqi@0:     if (res != NULL_WORD) {
aoqi@0:       guarantee( _pop_count_table == (void*) res, "invariant" );
aoqi@0:       FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
aoqi@0:   idx_t bits = 0;
aoqi@0: 
aoqi@0:   while (w != 0) {
aoqi@0:     while ((w & 1) == 0) {
aoqi@0:       w >>= 1;
aoqi@0:     }
aoqi@0:     bits++;
aoqi@0:     w >>= 1;
aoqi@0:   }
aoqi@0:   return bits;
aoqi@0: }
aoqi@0: 
aoqi@0: BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
aoqi@0:   assert(_pop_count_table != NULL, "precondition");
aoqi@0:   return _pop_count_table[c];
aoqi@0: }
aoqi@0: 
aoqi@0: BitMap::idx_t BitMap::count_one_bits() const {
aoqi@0:   init_pop_count_table(); // If necessary.
aoqi@0:   idx_t sum = 0;
aoqi@0:   typedef unsigned char uchar;
aoqi@0:   for (idx_t i = 0; i < size_in_words(); i++) {
aoqi@0:     bm_word_t w = map()[i];
aoqi@0:     for (size_t j = 0; j < sizeof(bm_word_t); j++) {
aoqi@0:       sum += num_set_bits_from_table(uchar(w & 255));
aoqi@0:       w >>= 8;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return sum;
aoqi@0: }
aoqi@0: 
aoqi@0: void BitMap::print_on_error(outputStream* st, const char* prefix) const {
aoqi@0:   st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")",
aoqi@0:       prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte)));
aoqi@0: }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0: 
aoqi@0: void BitMap::print_on(outputStream* st) const {
aoqi@0:   tty->print("Bitmap(" SIZE_FORMAT "):", size());
aoqi@0:   for (idx_t index = 0; index < size(); index++) {
aoqi@0:     tty->print("%c", at(index) ? '1' : '0');
aoqi@0:   }
aoqi@0:   tty->cr();
aoqi@0: }
aoqi@0: 
aoqi@0: #endif
aoqi@0: 
aoqi@0: 
aoqi@0: BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
aoqi@0:   : _bits_per_slot(bits_per_slot)
aoqi@0:   , _map(map, size_in_slots * bits_per_slot)
aoqi@0: {
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
aoqi@0:   : _bits_per_slot(bits_per_slot)
aoqi@0:   , _map(size_in_slots * bits_per_slot)
aoqi@0: {
aoqi@0: }