Initial load

hotspot/src/share/vm/utilities/bitMap.hpp

@@ -0,0 +1,396 @@
+/*
+ * 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);
+    }
+  }
+}