/*
* Copyright (c) 2005, 2012, 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.
*
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* 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.
*
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*/
#ifndef SHARE_VM_UTILITIES_BITMAP_INLINE_HPP
#define SHARE_VM_UTILITIES_BITMAP_INLINE_HPP
#include "runtime/atomic.hpp"
#include "utilities/bitMap.hpp"
#ifdef ASSERT
inline void BitMap::verify_index(idx_t index) const {
assert(index < _size, "BitMap index out of bounds");
}
inline 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
inline void BitMap::set_bit(idx_t bit) {
verify_index(bit);
*word_addr(bit) |= bit_mask(bit);
}
inline void BitMap::clear_bit(idx_t bit) {
verify_index(bit);
*word_addr(bit) &= ~bit_mask(bit);
}
inline bool BitMap::par_set_bit(idx_t bit) {
verify_index(bit);
volatile idx_t* const addr = word_addr(bit);
const idx_t mask = bit_mask(bit);
idx_t old_val = *addr;
do {
const idx_t new_val = old_val | mask;
if (new_val == old_val) {
return false; // Someone else beat us to it.
}
const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,
(volatile void*) addr,
(void*) old_val);
if (cur_val == old_val) {
return true; // Success.
}
old_val = cur_val; // The value changed, try again.
} while (true);
}
inline bool BitMap::par_clear_bit(idx_t bit) {
verify_index(bit);
volatile idx_t* const addr = word_addr(bit);
const idx_t mask = ~bit_mask(bit);
idx_t old_val = *addr;
do {
const idx_t new_val = old_val & mask;
if (new_val == old_val) {
return false; // Someone else beat us to it.
}
const idx_t cur_val = (idx_t) Atomic::cmpxchg_ptr((void*) new_val,
(volatile void*) addr,
(void*) old_val);
if (cur_val == old_val) {
return true; // Success.
}
old_val = cur_val; // The value changed, try again.
} while (true);
}
inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
if (hint == small_range && end - beg == 1) {
set_bit(beg);
} else {
if (hint == large_range) {
set_large_range(beg, end);
} else {
set_range(beg, end);
}
}
}
inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
if (hint == small_range && end - beg == 1) {
clear_bit(beg);
} else {
if (hint == large_range) {
clear_large_range(beg, end);
} else {
clear_range(beg, end);
}
}
}
inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
if (hint == small_range && end - beg == 1) {
par_at_put(beg, true);
} else {
if (hint == large_range) {
par_at_put_large_range(beg, end, true);
} else {
par_at_put_range(beg, end, true);
}
}
}
inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {
bm_word_t* map = _map;
for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0;
}
inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) {
bm_word_t* map = _map;
for (idx_t i = beg; i < end; ++i) map[i] = 0;
}
inline void BitMap::clear() {
clear_range_of_words(0, size_in_words());
}
inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
if (hint == small_range && end - beg == 1) {
par_at_put(beg, false);
} else {
if (hint == large_range) {
par_at_put_large_range(beg, end, false);
} else {
par_at_put_range(beg, end, false);
}
}
}
inline BitMap::idx_t
BitMap::get_next_one_offset_inline(idx_t l_offset, idx_t r_offset) const {
assert(l_offset <= size(), "BitMap index out of bounds");
assert(r_offset <= size(), "BitMap index out of bounds");
assert(l_offset <= r_offset, "l_offset > r_offset ?");
if (l_offset == r_offset) {
return l_offset;
}
idx_t index = word_index(l_offset);
idx_t r_index = word_index(r_offset-1) + 1;
idx_t res_offset = l_offset;
// check bits including and to the _left_ of offset's position
idx_t pos = bit_in_word(res_offset);
idx_t res = map(index) >> pos;
if (res != (uintptr_t)NoBits) {
// find the position of the 1-bit
for (; !(res & 1); res_offset++) {
res = res >> 1;
}
#ifdef ASSERT
// In the following assert, if r_offset is not bitamp word aligned,
// checking that res_offset is strictly less than r_offset is too
// strong and will trip the assert.
//
// Consider the case where l_offset is bit 15 and r_offset is bit 17
// of the same map word, and where bits [15:16:17:18] == [00:00:00:01].
// All the bits in the range [l_offset:r_offset) are 0.
// The loop that calculates res_offset, above, would yield the offset
// of bit 18 because it's in the same map word as l_offset and there
// is a set bit in that map word above l_offset (i.e. res != NoBits).
//
// In this case, however, we can assert is that res_offset is strictly
// less than size() since we know that there is at least one set bit
// at an offset above, but in the same map word as, r_offset.
// Otherwise, if r_offset is word aligned then it will not be in the
// same map word as l_offset (unless it equals l_offset). So either
// there won't be a set bit between l_offset and the end of it's map
// word (i.e. res == NoBits), or res_offset will be less than r_offset.
idx_t limit = is_word_aligned(r_offset) ? r_offset : size();
assert(res_offset >= l_offset && res_offset < limit, "just checking");
#endif // ASSERT
return MIN2(res_offset, r_offset);
}
// skip over all word length 0-bit runs
for (index++; index < r_index; index++) {
res = map(index);
if (res != (uintptr_t)NoBits) {
// found a 1, return the offset
for (res_offset = bit_index(index); !(res & 1); res_offset++) {
res = res >> 1;
}
assert(res & 1, "tautology; see loop condition");
assert(res_offset >= l_offset, "just checking");
return MIN2(res_offset, r_offset);
}
}
return r_offset;
}
inline BitMap::idx_t
BitMap::get_next_zero_offset_inline(idx_t l_offset, idx_t r_offset) const {
assert(l_offset <= size(), "BitMap index out of bounds");
assert(r_offset <= size(), "BitMap index out of bounds");
assert(l_offset <= r_offset, "l_offset > r_offset ?");
if (l_offset == r_offset) {
return l_offset;
}
idx_t index = word_index(l_offset);
idx_t r_index = word_index(r_offset-1) + 1;
idx_t res_offset = l_offset;
// check bits including and to the _left_ of offset's position
idx_t pos = res_offset & (BitsPerWord - 1);
idx_t res = (map(index) >> pos) | left_n_bits((int)pos);
if (res != (uintptr_t)AllBits) {
// find the position of the 0-bit
for (; res & 1; res_offset++) {
res = res >> 1;
}
assert(res_offset >= l_offset, "just checking");
return MIN2(res_offset, r_offset);
}
// skip over all word length 1-bit runs
for (index++; index < r_index; index++) {
res = map(index);
if (res != (uintptr_t)AllBits) {
// found a 0, return the offset
for (res_offset = index << LogBitsPerWord; res & 1;
res_offset++) {
res = res >> 1;
}
assert(!(res & 1), "tautology; see loop condition");
assert(res_offset >= l_offset, "just checking");
return MIN2(res_offset, r_offset);
}
}
return r_offset;
}
inline BitMap::idx_t
BitMap::get_next_one_offset_inline_aligned_right(idx_t l_offset,
idx_t r_offset) const
{
verify_range(l_offset, r_offset);
assert(bit_in_word(r_offset) == 0, "r_offset not word-aligned");
if (l_offset == r_offset) {
return l_offset;
}
idx_t index = word_index(l_offset);
idx_t r_index = word_index(r_offset);
idx_t res_offset = l_offset;
// check bits including and to the _left_ of offset's position
idx_t res = map(index) >> bit_in_word(res_offset);
if (res != (uintptr_t)NoBits) {
// find the position of the 1-bit
for (; !(res & 1); res_offset++) {
res = res >> 1;
}
assert(res_offset >= l_offset &&
res_offset < r_offset, "just checking");
return res_offset;
}
// skip over all word length 0-bit runs
for (index++; index < r_index; index++) {
res = map(index);
if (res != (uintptr_t)NoBits) {
// found a 1, return the offset
for (res_offset = bit_index(index); !(res & 1); res_offset++) {
res = res >> 1;
}
assert(res & 1, "tautology; see loop condition");
assert(res_offset >= l_offset && res_offset < r_offset, "just checking");
return res_offset;
}
}
return r_offset;
}
// Returns a bit mask for a range of bits [beg, end) within a single word. Each
// bit in the mask is 0 if the bit is in the range, 1 if not in the range. The
// returned mask can be used directly to clear the range, or inverted to set the
// range. Note: end must not be 0.
inline BitMap::bm_word_t
BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const {
assert(end != 0, "does not work when end == 0");
assert(beg == end || word_index(beg) == word_index(end - 1),
"must be a single-word range");
bm_word_t mask = bit_mask(beg) - 1; // low (right) bits
if (bit_in_word(end) != 0) {
mask |= ~(bit_mask(end) - 1); // high (left) bits
}
return mask;
}
inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) {
memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(uintptr_t));
}
inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) {
memset(_map + beg, 0, (end - beg) * sizeof(uintptr_t));
}
inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const {
idx_t bit_rounded_up = bit + (BitsPerWord - 1);
// Check for integer arithmetic overflow.
return bit_rounded_up > bit ? word_index(bit_rounded_up) : size_in_words();
}
inline BitMap::idx_t BitMap::get_next_one_offset(idx_t l_offset,
idx_t r_offset) const {
return get_next_one_offset_inline(l_offset, r_offset);
}
inline BitMap::idx_t BitMap::get_next_zero_offset(idx_t l_offset,
idx_t r_offset) const {
return get_next_zero_offset_inline(l_offset, r_offset);
}
inline void BitMap2D::clear() {
_map.clear();
}
#endif // SHARE_VM_UTILITIES_BITMAP_INLINE_HPP