--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/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)
+{
+}