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 /*

  * Copyright (c) 1997, 2014, 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.

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  */

 #include "precompiled.hpp"

 #include "memory/allocation.inline.hpp"

 #include "utilities/bitMap.inline.hpp"

 #include "utilities/copy.hpp"

 #ifdef TARGET_OS_FAMILY_linux

 # include "os_linux.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_solaris

 # include "os_solaris.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_windows

 # include "os_windows.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_aix

 # include "os_aix.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_bsd

 # include "os_bsd.inline.hpp"

 #endif

 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :

   _map(map), _size(size_in_bits), _map_allocator(false)

 {

   assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");

   assert(size_in_bits >= 0, "just checking");

 }

 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :

   _map(NULL), _size(0), _map_allocator(false)

 {

   assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");

   resize(size_in_bits, in_resource_area);

 }

 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {

   assert(size_in_bits >= 0, "just checking");

   idx_t old_size_in_words = size_in_words();

   bm_word_t* old_map = map();

   _size = size_in_bits;

   idx_t new_size_in_words = size_in_words();

   if (in_resource_area) {

     _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);

   } else {

     if (old_map != NULL) {

       _map_allocator.free();

     }

     _map = _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(old_size_in_words, size_in_words());

   }

 }

 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) {

     intptr_t* pw  = (intptr_t*)word_addr(beg);

     intptr_t  w   = *pw;

     intptr_t  mr  = (intptr_t)inverted_bit_mask_for_range(beg, end);

     intptr_t  nw  = value ? (w | ~mr) : (w & mr);

     while (true) {

       intptr_t res = Atomic::cmpxchg_ptr(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);

   }

 }

 bool BitMap::is_small_range_of_words(idx_t beg_full_word, idx_t end_full_word) {

   // There is little point to call large version on small ranges.

   // Need to check carefully, keeping potential idx_t underflow in mind.

   // The threshold should be at least one word.

   STATIC_ASSERT(small_range_words >= 1);

   return (beg_full_word + small_range_words >= end_full_word);

 }

 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);

   if (is_small_range_of_words(beg_full_word, end_full_word)) {

     set_range(beg, end);

     return;

   }

   // 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 (is_small_range_of_words(beg_full_word, end_full_word)) {

     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_grow(idx_t offset, bool value) {

   if (offset >= size()) {

     resize(2 * MAX2(size(), offset));

   }

   at_put(offset, value);

 }

 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);

   if (is_small_range_of_words(beg_full_word, end_full_word)) {

     par_at_put_range(beg, end, value);

     return;

   }

   // 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);

 }

 bool BitMap::contains(const BitMap other) const {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size_in_words(); index++) {

     bm_word_t word_union = dest_map[index] | other_map[index];

     // If this has more bits set than dest_map[index], then other is not a

     // subset.

     if (word_union != dest_map[index]) return false;

   }

   return true;

 }

 bool BitMap::intersects(const BitMap other) const {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size_in_words(); index++) {

     if ((dest_map[index] & other_map[index]) != 0) return true;

   }

   // Otherwise, no intersection.

   return false;

 }

 void BitMap::set_union(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size_in_words(); index++) {

     dest_map[index] = dest_map[index] | other_map[index];

   }

 }

 void BitMap::set_difference(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size_in_words(); index++) {

     dest_map[index] = dest_map[index] & ~(other_map[index]);

   }

 }

 void BitMap::set_intersection(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     dest_map[index]  = dest_map[index] & other_map[index];

   }

 }

 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {

   assert(other.size() >= offset, "offset not in range");

   assert(other.size() - offset >= size(), "other not large enough");

   // XXX Ideally, we would remove this restriction.

   guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,

             "Only handle aligned cases so far.");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t offset_word_ind = word_index(offset);

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];

   }

 }

 bool BitMap::set_union_with_result(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bool changed = false;

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     idx_t temp = map(index) | other_map[index];

     changed = changed || (temp != map(index));

     map()[index] = temp;

   }

   return changed;

 }

 bool BitMap::set_difference_with_result(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bool changed = false;

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     bm_word_t temp = dest_map[index] & ~(other_map[index]);

     changed = changed || (temp != dest_map[index]);

     dest_map[index] = temp;

   }

   return changed;

 }

 bool BitMap::set_intersection_with_result(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bool changed = false;

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     bm_word_t orig = dest_map[index];

     bm_word_t temp = orig & other_map[index];

     changed = changed || (temp != orig);

     dest_map[index]  = temp;

   }

   return changed;

 }

 void BitMap::set_from(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     dest_map[index] = other_map[index];

   }

 }

 bool BitMap::is_same(BitMap other) {

   assert(size() == other.size(), "must have same size");

   bm_word_t* dest_map = map();

   bm_word_t* other_map = other.map();

   idx_t size = size_in_words();

   for (idx_t index = 0; index < size; index++) {

     if (dest_map[index] != other_map[index]) return false;

   }

   return true;

 }

 bool BitMap::is_full() const {

   bm_word_t* word = map();

   idx_t rest = size();

   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {

     if (*word != (bm_word_t) AllBits) return false;

     word++;

   }

   return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;

 }

 bool BitMap::is_empty() const {

   bm_word_t* word = map();

   idx_t rest = size();

   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {

     if (*word != (bm_word_t) NoBits) return false;

     word++;

   }

   return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;

 }

 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 != (bm_word_t)NoBits; 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;

 }

 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);

     }

     intptr_t res = Atomic::cmpxchg_ptr((intptr_t)  table,

                                        (intptr_t*) &_pop_count_table,

                                        (intptr_t)  NULL_WORD);

     if (res != NULL_WORD) {

       guarantee( _pop_count_table == (void*) res, "invariant" );

       FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal);

     }

   }

 }

 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

 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)

   : _bits_per_slot(bits_per_slot)

   , _map(map, size_in_slots * bits_per_slot)

 {

 }

 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)

   : _bits_per_slot(bits_per_slot)

   , _map(size_in_slots * bits_per_slot)

 {

 }