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/*
* Copyright (c) 1997, 2022, 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"
#include "utilities/population_count.hpp"
using bm_word_t = BitMap::bm_word_t;
using idx_t = BitMap::idx_t;
STATIC_ASSERT(sizeof(bm_word_t) == BytesPerWord); // "Implementation assumption."
// For the BitMaps with allocators that don't support reallocate
template <class BitMapWithAllocator>
static bm_word_t* pseudo_reallocate(const BitMapWithAllocator& derived, bm_word_t* old_map, size_t old_size_in_words, size_t new_size_in_words) {
assert(new_size_in_words > 0, "precondition");
bm_word_t* map = derived.allocate(new_size_in_words);
if (old_map != NULL) {
Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) map,
MIN2(old_size_in_words, new_size_in_words));
}
derived.free(old_map, old_size_in_words);
return map;
}
template <class BitMapWithAllocator>
void GrowableBitMap<BitMapWithAllocator>::initialize(idx_t size_in_bits, bool clear) {
assert(map() == NULL, "precondition");
assert(size() == 0, "precondition");
resize(size_in_bits, clear);
}
template <class BitMapWithAllocator>
void GrowableBitMap<BitMapWithAllocator>::reinitialize(idx_t new_size_in_bits, bool clear) {
// Remove previous bits - no need to clear
resize(0, false /* clear */);
initialize(new_size_in_bits, clear);
}
template <class BitMapWithAllocator>
void GrowableBitMap<BitMapWithAllocator>::resize(idx_t new_size_in_bits, bool clear) {
const size_t old_size_in_bits = size();
bm_word_t* const old_map = map();
const size_t old_size_in_words = calc_size_in_words(size());
const size_t new_size_in_words = calc_size_in_words(new_size_in_bits);
BitMapWithAllocator* derived = static_cast<BitMapWithAllocator*>(this);
if (new_size_in_words == 0) {
derived->free(old_map, old_size_in_words);
update(NULL, 0);
return;
}
bm_word_t* map = derived->reallocate(old_map, old_size_in_words, new_size_in_words);
if (clear && (new_size_in_bits > old_size_in_bits)) {
// If old_size_in_bits is not word-aligned, then the preceding
// copy can include some trailing bits in the final copied word
// that also need to be cleared. See clear_range_within_word.
bm_word_t mask = bit_mask(old_size_in_bits) - 1;
map[raw_to_words_align_down(old_size_in_bits)] &= mask;
// Clear the remaining full words.
clear_range_of_words(map, old_size_in_words, new_size_in_words);
}
update(map, new_size_in_bits);
}
ArenaBitMap::ArenaBitMap(Arena* arena, idx_t size_in_bits, bool clear)
: GrowableBitMap<ArenaBitMap>(), _arena(arena) {
initialize(size_in_bits, clear);
}
bm_word_t* ArenaBitMap::allocate(idx_t size_in_words) const {
return (bm_word_t*)_arena->Amalloc(size_in_words * BytesPerWord);
}
bm_word_t* ArenaBitMap::reallocate(bm_word_t* old_map, size_t old_size_in_words, size_t new_size_in_words) const {
return pseudo_reallocate(*this, old_map, old_size_in_words, new_size_in_words);
}
ResourceBitMap::ResourceBitMap(idx_t size_in_bits, bool clear)
: GrowableBitMap<ResourceBitMap>() {
initialize(size_in_bits, clear);
}
bm_word_t* ResourceBitMap::allocate(idx_t size_in_words) const {
return (bm_word_t*)NEW_RESOURCE_ARRAY(bm_word_t, size_in_words);
}
bm_word_t* ResourceBitMap::reallocate(bm_word_t* old_map, size_t old_size_in_words, size_t new_size_in_words) const {
return pseudo_reallocate(*this, old_map, old_size_in_words, new_size_in_words);
}
CHeapBitMap::CHeapBitMap(idx_t size_in_bits, MEMFLAGS flags, bool clear)
: GrowableBitMap<CHeapBitMap>(), _flags(flags) {
initialize(size_in_bits, clear);
}
CHeapBitMap::~CHeapBitMap() {
free(map(), size());
}
bm_word_t* CHeapBitMap::allocate(idx_t size_in_words) const {
return ArrayAllocator<bm_word_t>::allocate(size_in_words, _flags);
}
void CHeapBitMap::free(bm_word_t* map, idx_t size_in_words) const {
ArrayAllocator<bm_word_t>::free(map, size_in_words);
}
bm_word_t* CHeapBitMap::reallocate(bm_word_t* map, size_t old_size_in_words, size_t new_size_in_words) const {
return ArrayAllocator<bm_word_t>::reallocate(map, old_size_in_words, new_size_in_words, _flags);
}
#ifdef ASSERT
void BitMap::verify_size(idx_t size_in_bits) {
assert(size_in_bits <= max_size_in_bits(),
"out of bounds: " SIZE_FORMAT, size_in_bits);
}
void BitMap::verify_index(idx_t bit) const {
assert(bit < _size,
"BitMap index out of bounds: " SIZE_FORMAT " >= " SIZE_FORMAT,
bit, _size);
}
void BitMap::verify_limit(idx_t bit) const {
assert(bit <= _size,
"BitMap limit out of bounds: " SIZE_FORMAT " > " SIZE_FORMAT,
bit, _size);
}
void BitMap::verify_range(idx_t beg, idx_t end) const {
assert(beg <= end,
"BitMap range error: " SIZE_FORMAT " > " SIZE_FORMAT, beg, end);
verify_limit(end);
}
#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) {
volatile bm_word_t* pw = word_addr(beg);
bm_word_t w = Atomic::load(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(pw, w, nw);
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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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 over/underflow in mind,
// because beg_full_word > end_full_word can occur when beg and end are in
// the same word.
// 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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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 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 beg_offset, idx_t end_offset, bool value) {
if (value) {
set_range(beg_offset, end_offset);
} else {
clear_range(beg_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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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 = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(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);
}
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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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 = to_words_align_down(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());
}
BitMap::idx_t BitMap::count_one_bits_in_range_of_words(idx_t beg_full_word, idx_t end_full_word) const {
idx_t sum = 0;
for (idx_t i = beg_full_word; i < end_full_word; i++) {
bm_word_t w = map()[i];
sum += population_count(w);
}
return sum;
}
BitMap::idx_t BitMap::count_one_bits_within_word(idx_t beg, idx_t end) const {
if (beg != end) {
assert(end > beg, "must be");
bm_word_t mask = ~inverted_bit_mask_for_range(beg, end);
bm_word_t w = *word_addr(beg);
w &= mask;
return population_count(w);
}
return 0;
}
BitMap::idx_t BitMap::count_one_bits() const {
return count_one_bits(0, size());
}
// Returns the number of bits set within [beg, end).
BitMap::idx_t BitMap::count_one_bits(idx_t beg, idx_t end) const {
verify_range(beg, end);
idx_t beg_full_word = to_words_align_up(beg);
idx_t end_full_word = to_words_align_down(end);
idx_t sum = 0;
if (beg_full_word < end_full_word) {
// The range includes at least one full word.
sum += count_one_bits_within_word(beg, bit_index(beg_full_word));
sum += count_one_bits_in_range_of_words(beg_full_word, end_full_word);
sum += count_one_bits_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);
sum += count_one_bits_within_word(beg, boundary);
sum += count_one_bits_within_word(boundary, end);
}
assert(sum <= (beg - end), "must be");
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)));
}
void BitMap::write_to(bm_word_t* buffer, size_t buffer_size_in_bytes) const {
assert(buffer_size_in_bytes == size_in_bytes(), "must be");
memcpy(buffer, _map, size_in_bytes());
}
#ifndef PRODUCT
void BitMap::print_on(outputStream* st) const {
st->print("Bitmap (" SIZE_FORMAT " bits):", size());
for (idx_t index = 0; index < size(); index++) {
if ((index % 64) == 0) {
st->cr();
st->print(SIZE_FORMAT_W(5) ":", index);
}
if ((index % 8) == 0) {
st->print(" ");
}
st->print("%c", at(index) ? 'S' : '.');
}
st->cr();
}
#endif
template class GrowableBitMap<ArenaBitMap>;
template class GrowableBitMap<ResourceBitMap>;
template class GrowableBitMap<CHeapBitMap>;
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