Mercurial > hg > truffle
diff src/share/vm/utilities/bitMap.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 37f87013dfd8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/utilities/bitMap.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,572 @@ +/* + * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +# include "incls/_precompiled.incl" +# include "incls/_bitMap.cpp.incl" + + +BitMap::BitMap(idx_t* map, idx_t size_in_bits) { + assert(size_in_bits >= 0, "just checking"); + _map = map; + _size = size_in_bits; +} + + +BitMap::BitMap(idx_t size_in_bits) { + assert(size_in_bits >= 0, "just checking"); + _size = size_in_bits; + _map = NEW_RESOURCE_ARRAY(idx_t, size_in_words()); +} + + +void BitMap::resize(idx_t size_in_bits) { + assert(size_in_bits >= 0, "just checking"); + size_t old_size_in_words = size_in_words(); + uintptr_t* old_map = map(); + _size = size_in_bits; + size_t new_size_in_words = size_in_words(); + _map = NEW_RESOURCE_ARRAY(idx_t, 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()); + } +} + +// 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::idx_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"); + idx_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; +} + +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) { + idx_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) { + idx_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 = *pw; + nw = value ? (w | ~mr) : (w & mr); + } + } +} + +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(); +} + +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); + + assert(end_full_word - beg_full_word >= 32, + "the range must include at least 32 bytes"); + + // 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); + + 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); +} + +bool BitMap::contains(const BitMap other) const { + assert(size() == other.size(), "must have same size"); + uintptr_t* dest_map = map(); + uintptr_t* other_map = other.map(); + idx_t size = size_in_words(); + for (idx_t index = 0; index < size_in_words(); index++) { + uintptr_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"); + uintptr_t* dest_map = map(); + uintptr_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"); + idx_t* dest_map = map(); + idx_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"); + idx_t* dest_map = map(); + idx_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"); + idx_t* dest_map = map(); + idx_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]; + } +} + + +bool BitMap::set_union_with_result(BitMap other) { + assert(size() == other.size(), "must have same size"); + bool changed = false; + idx_t* dest_map = map(); + idx_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; + idx_t* dest_map = map(); + idx_t* other_map = other.map(); + idx_t size = size_in_words(); + for (idx_t index = 0; index < size; index++) { + idx_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; + idx_t* dest_map = map(); + idx_t* other_map = other.map(); + idx_t size = size_in_words(); + for (idx_t index = 0; index < size; index++) { + idx_t orig = dest_map[index]; + idx_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"); + idx_t* dest_map = map(); + idx_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"); + idx_t* dest_map = map(); + idx_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 { + uintptr_t* word = map(); + idx_t rest = size(); + for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { + if (*word != (uintptr_t) AllBits) return false; + word++; + } + return rest == 0 || (*word | ~right_n_bits((int)rest)) == (uintptr_t) AllBits; +} + + +bool BitMap::is_empty() const { + uintptr_t* word = map(); + idx_t rest = size(); + for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { + if (*word != (uintptr_t) NoBits) return false; + word++; + } + return rest == 0 || (*word & right_n_bits((int)rest)) == (uintptr_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. +void 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 != (uintptr_t)NoBits; offset++) { + if (rest & 1) { + blk->do_bit(offset); + // resample at each closure application + // (see, for instance, CMS bug 4525989) + rest = map(index) >> (offset & (BitsPerWord -1)); + // XXX debugging: remove + // The following assertion assumes that closure application + // doesn't clear bits (may not be true in general, e.g. G1). + assert(rest & 1, + "incorrect shift or closure application can clear bits?"); + } + rest = rest >> 1; + } + } +} + +BitMap::idx_t BitMap::get_next_one_offset(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; + } + assert(res_offset >= l_offset, "just checking"); + 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 = 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; +} + +BitMap::idx_t BitMap::get_next_zero_offset(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; +} + +#ifndef PRODUCT + +void BitMap::print_on(outputStream* st) const { + tty->print("Bitmap(%d):", size()); + for (idx_t index = 0; index < size(); index++) { + tty->print("%c", at(index) ? '1' : '0'); + } + tty->cr(); +} + +#endif + + +BitMap2D::BitMap2D(uintptr_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) +{ +}