/* * 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. * */ // Closure for iterating over BitMaps class BitMapClosure VALUE_OBJ_CLASS_SPEC { public: // Callback when bit in map is set virtual void do_bit(size_t offset) = 0; }; // Operations for bitmaps represented as arrays of unsigned 32- or 64-bit // integers (uintptr_t). // // Bit offsets are numbered from 0 to size-1 class BitMap VALUE_OBJ_CLASS_SPEC { friend class BitMap2D; public: typedef size_t idx_t; // Type used for bit and word indices. // Hints for range sizes. typedef enum { unknown_range, small_range, large_range } RangeSizeHint; private: idx_t* _map; // First word in bitmap idx_t _size; // Size of bitmap (in bits) // Puts the given value at the given offset, using resize() to size // the bitmap appropriately if needed using factor-of-two expansion. void at_put_grow(idx_t index, bool value); protected: // Return the position of bit within the word that contains it (e.g., if // bitmap words are 32 bits, return a number 0 <= n <= 31). static idx_t bit_in_word(idx_t bit) { return bit & (BitsPerWord - 1); } // Return a mask that will select the specified bit, when applied to the word // containing the bit. static idx_t bit_mask(idx_t bit) { return (idx_t)1 << bit_in_word(bit); } // Return the index of the word containing the specified bit. static idx_t word_index(idx_t bit) { return bit >> LogBitsPerWord; } // Return the bit number of the first bit in the specified word. static idx_t bit_index(idx_t word) { return word << LogBitsPerWord; } // Return the array of bitmap words, or a specific word from it. idx_t* map() const { return _map; } idx_t map(idx_t word) const { return _map[word]; } // Return a pointer to the word containing the specified bit. idx_t* word_addr(idx_t bit) const { return map() + word_index(bit); } // Set a word to a specified value or to all ones; clear a word. void set_word (idx_t word, idx_t val) { _map[word] = val; } void set_word (idx_t word) { set_word(word, ~(uintptr_t)0); } void clear_word(idx_t word) { _map[word] = 0; } // Utilities for ranges of bits. Ranges are half-open [beg, end). // Ranges within a single word. inline idx_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const; inline void set_range_within_word (idx_t beg, idx_t end); inline void clear_range_within_word (idx_t beg, idx_t end); inline void par_put_range_within_word (idx_t beg, idx_t end, bool value); // Ranges spanning entire words. inline void set_range_of_words (idx_t beg, idx_t end); inline void clear_range_of_words (idx_t beg, idx_t end); inline void set_large_range_of_words (idx_t beg, idx_t end); inline void clear_large_range_of_words (idx_t beg, idx_t end); // The index of the first full word in a range. inline idx_t word_index_round_up(idx_t bit) const; // Verification, statistics. void verify_index(idx_t index) const { assert(index < _size, "BitMap index out of bounds"); } void verify_range(idx_t beg_index, idx_t end_index) const { #ifdef ASSERT 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 } public: // Constructs a bitmap with no map, and size 0. BitMap() : _map(NULL), _size(0) {} // Construction BitMap(idx_t* map, idx_t size_in_bits); // Allocates necessary data structure in resource area BitMap(idx_t size_in_bits); void set_map(idx_t* map) { _map = map; } void set_size(idx_t size_in_bits) { _size = size_in_bits; } // Allocates necessary data structure in resource area. // Preserves state currently in bit map by copying data. // Zeros any newly-addressable bits. // Does not perform any frees (i.e., of current _map). void resize(idx_t size_in_bits); // Accessing idx_t size() const { return _size; } idx_t size_in_words() const { return word_index(size() + BitsPerWord - 1); } bool at(idx_t index) const { verify_index(index); return (*word_addr(index) & bit_mask(index)) != 0; } // Align bit index up or down to the next bitmap word boundary, or check // alignment. static idx_t word_align_up(idx_t bit) { return align_size_up(bit, BitsPerWord); } static idx_t word_align_down(idx_t bit) { return align_size_down(bit, BitsPerWord); } static bool is_word_aligned(idx_t bit) { return word_align_up(bit) == bit; } // Set or clear the specified bit. inline void set_bit(idx_t bit); inline void clear_bit(idx_t bit); // Atomically set or clear the specified bit. inline bool par_set_bit(idx_t bit); inline bool par_clear_bit(idx_t bit); // Put the given value at the given offset. The parallel version // will CAS the value into the bitmap and is quite a bit slower. // The parallel version also returns a value indicating if the // calling thread was the one that changed the value of the bit. void at_put(idx_t index, bool value); bool par_at_put(idx_t index, bool value); // Update a range of bits. Ranges are half-open [beg, end). void set_range (idx_t beg, idx_t end); void clear_range (idx_t beg, idx_t end); void set_large_range (idx_t beg, idx_t end); void clear_large_range (idx_t beg, idx_t end); void at_put_range(idx_t beg, idx_t end, bool value); void par_at_put_range(idx_t beg, idx_t end, bool value); void at_put_large_range(idx_t beg, idx_t end, bool value); void par_at_put_large_range(idx_t beg, idx_t end, bool value); // Update a range of bits, using a hint about the size. Currently only // inlines the predominant case of a 1-bit range. Works best when hint is a // compile-time constant. inline void set_range(idx_t beg, idx_t end, RangeSizeHint hint); inline void clear_range(idx_t beg, idx_t end, RangeSizeHint hint); inline void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint); inline void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint); // Clearing void clear(); void clear_large(); // Iteration support void iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex); inline void iterate(BitMapClosure* blk) { // call the version that takes an interval iterate(blk, 0, size()); } // Looking for 1's and 0's to the "right" idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const; idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const; idx_t get_next_one_offset(idx_t offset) const { return get_next_one_offset(offset, size()); } idx_t get_next_zero_offset(idx_t offset) const { return get_next_zero_offset(offset, size()); } // Find the next one bit in the range [beg_bit, end_bit), or return end_bit if // no one bit is found. Equivalent to get_next_one_offset(), but inline for // use in performance-critical code. inline idx_t find_next_one_bit(idx_t beg_bit, idx_t end_bit) const; // Set operations. void set_union(BitMap bits); void set_difference(BitMap bits); void set_intersection(BitMap bits); // Returns true iff "this" is a superset of "bits". bool contains(const BitMap bits) const; // Returns true iff "this and "bits" have a non-empty intersection. bool intersects(const BitMap bits) const; // Returns result of whether this map changed // during the operation bool set_union_with_result(BitMap bits); bool set_difference_with_result(BitMap bits); bool set_intersection_with_result(BitMap bits); void set_from(BitMap bits); bool is_same(BitMap bits); // Test if all bits are set or cleared bool is_full() const; bool is_empty() const; #ifndef PRODUCT public: // Printing void print_on(outputStream* st) const; #endif }; 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 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); } } } // Convenience class wrapping BitMap which provides multiple bits per slot. class BitMap2D VALUE_OBJ_CLASS_SPEC { public: typedef size_t idx_t; // Type used for bit and word indices. private: BitMap _map; idx_t _bits_per_slot; idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const { return slot_index * _bits_per_slot + bit_within_slot_index; } void verify_bit_within_slot_index(idx_t index) const { assert(index < _bits_per_slot, "bit_within_slot index out of bounds"); } public: // Construction. bits_per_slot must be greater than 0. BitMap2D(uintptr_t* map, idx_t size_in_slots, idx_t bits_per_slot); // Allocates necessary data structure in resource area. bits_per_slot must be greater than 0. BitMap2D(idx_t size_in_slots, idx_t bits_per_slot); idx_t size_in_bits() { return _map.size(); } // Returns number of full slots that have been allocated idx_t size_in_slots() { // Round down return _map.size() / _bits_per_slot; } bool is_valid_index(idx_t slot_index, idx_t bit_within_slot_index) { verify_bit_within_slot_index(bit_within_slot_index); return (bit_index(slot_index, bit_within_slot_index) < size_in_bits()); } bool at(idx_t slot_index, idx_t bit_within_slot_index) const { verify_bit_within_slot_index(bit_within_slot_index); return _map.at(bit_index(slot_index, bit_within_slot_index)); } void set_bit(idx_t slot_index, idx_t bit_within_slot_index) { verify_bit_within_slot_index(bit_within_slot_index); _map.set_bit(bit_index(slot_index, bit_within_slot_index)); } void clear_bit(idx_t slot_index, idx_t bit_within_slot_index) { verify_bit_within_slot_index(bit_within_slot_index); _map.clear_bit(bit_index(slot_index, bit_within_slot_index)); } void at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value) { verify_bit_within_slot_index(bit_within_slot_index); _map.at_put(bit_index(slot_index, bit_within_slot_index), value); } void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) { verify_bit_within_slot_index(bit_within_slot_index); _map.at_put_grow(bit_index(slot_index, bit_within_slot_index), value); } void clear() { _map.clear(); } }; inline void BitMap::set_range_of_words(idx_t beg, idx_t end) { uintptr_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) { uintptr_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); } } }