20 * CA 95054 USA or visit www.sun.com if you need additional information or |
20 * CA 95054 USA or visit www.sun.com if you need additional information or |
21 * have any questions. |
21 * have any questions. |
22 * |
22 * |
23 */ |
23 */ |
24 |
24 |
25 // Closure for iterating over BitMaps |
25 // Forward decl; |
26 |
26 class BitMapClosure; |
27 class BitMapClosure VALUE_OBJ_CLASS_SPEC { |
27 |
28 public: |
28 // Operations for bitmaps represented as arrays of unsigned integers. |
29 // Callback when bit in map is set |
29 // Bit offsets are numbered from 0 to size-1. |
30 virtual void do_bit(size_t offset) = 0; |
|
31 }; |
|
32 |
|
33 |
|
34 // Operations for bitmaps represented as arrays of unsigned 32- or 64-bit |
|
35 // integers (uintptr_t). |
|
36 // |
|
37 // Bit offsets are numbered from 0 to size-1 |
|
38 |
30 |
39 class BitMap VALUE_OBJ_CLASS_SPEC { |
31 class BitMap VALUE_OBJ_CLASS_SPEC { |
40 friend class BitMap2D; |
32 friend class BitMap2D; |
41 |
33 |
42 public: |
34 public: |
43 typedef size_t idx_t; // Type used for bit and word indices. |
35 typedef size_t idx_t; // Type used for bit and word indices. |
|
36 typedef uintptr_t bm_word_t; // Element type of array that represents |
|
37 // the bitmap. |
44 |
38 |
45 // Hints for range sizes. |
39 // Hints for range sizes. |
46 typedef enum { |
40 typedef enum { |
47 unknown_range, small_range, large_range |
41 unknown_range, small_range, large_range |
48 } RangeSizeHint; |
42 } RangeSizeHint; |
49 |
43 |
50 private: |
44 private: |
51 idx_t* _map; // First word in bitmap |
45 bm_word_t* _map; // First word in bitmap |
52 idx_t _size; // Size of bitmap (in bits) |
46 idx_t _size; // Size of bitmap (in bits) |
53 |
47 |
54 // Puts the given value at the given offset, using resize() to size |
48 // Puts the given value at the given offset, using resize() to size |
55 // the bitmap appropriately if needed using factor-of-two expansion. |
49 // the bitmap appropriately if needed using factor-of-two expansion. |
56 void at_put_grow(idx_t index, bool value); |
50 void at_put_grow(idx_t index, bool value); |
57 |
51 |
60 // bitmap words are 32 bits, return a number 0 <= n <= 31). |
54 // bitmap words are 32 bits, return a number 0 <= n <= 31). |
61 static idx_t bit_in_word(idx_t bit) { return bit & (BitsPerWord - 1); } |
55 static idx_t bit_in_word(idx_t bit) { return bit & (BitsPerWord - 1); } |
62 |
56 |
63 // Return a mask that will select the specified bit, when applied to the word |
57 // Return a mask that will select the specified bit, when applied to the word |
64 // containing the bit. |
58 // containing the bit. |
65 static idx_t bit_mask(idx_t bit) { return (idx_t)1 << bit_in_word(bit); } |
59 static bm_word_t bit_mask(idx_t bit) { return (bm_word_t)1 << bit_in_word(bit); } |
66 |
60 |
67 // Return the index of the word containing the specified bit. |
61 // Return the index of the word containing the specified bit. |
68 static idx_t word_index(idx_t bit) { return bit >> LogBitsPerWord; } |
62 static idx_t word_index(idx_t bit) { return bit >> LogBitsPerWord; } |
69 |
63 |
70 // Return the bit number of the first bit in the specified word. |
64 // Return the bit number of the first bit in the specified word. |
71 static idx_t bit_index(idx_t word) { return word << LogBitsPerWord; } |
65 static idx_t bit_index(idx_t word) { return word << LogBitsPerWord; } |
72 |
66 |
73 // Return the array of bitmap words, or a specific word from it. |
67 // Return the array of bitmap words, or a specific word from it. |
74 idx_t* map() const { return _map; } |
68 bm_word_t* map() const { return _map; } |
75 idx_t map(idx_t word) const { return _map[word]; } |
69 bm_word_t map(idx_t word) const { return _map[word]; } |
76 |
70 |
77 // Return a pointer to the word containing the specified bit. |
71 // Return a pointer to the word containing the specified bit. |
78 idx_t* word_addr(idx_t bit) const { return map() + word_index(bit); } |
72 bm_word_t* word_addr(idx_t bit) const { return map() + word_index(bit); } |
79 |
73 |
80 // Set a word to a specified value or to all ones; clear a word. |
74 // Set a word to a specified value or to all ones; clear a word. |
81 void set_word (idx_t word, idx_t val) { _map[word] = val; } |
75 void set_word (idx_t word, bm_word_t val) { _map[word] = val; } |
82 void set_word (idx_t word) { set_word(word, ~(uintptr_t)0); } |
76 void set_word (idx_t word) { set_word(word, ~(uintptr_t)0); } |
83 void clear_word(idx_t word) { _map[word] = 0; } |
77 void clear_word(idx_t word) { _map[word] = 0; } |
84 |
78 |
85 // Utilities for ranges of bits. Ranges are half-open [beg, end). |
79 // Utilities for ranges of bits. Ranges are half-open [beg, end). |
86 |
80 |
87 // Ranges within a single word. |
81 // Ranges within a single word. |
88 inline idx_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const; |
82 bm_word_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const; |
89 inline void set_range_within_word (idx_t beg, idx_t end); |
83 void set_range_within_word (idx_t beg, idx_t end); |
90 inline void clear_range_within_word (idx_t beg, idx_t end); |
84 void clear_range_within_word (idx_t beg, idx_t end); |
91 inline void par_put_range_within_word (idx_t beg, idx_t end, bool value); |
85 void par_put_range_within_word (idx_t beg, idx_t end, bool value); |
92 |
86 |
93 // Ranges spanning entire words. |
87 // Ranges spanning entire words. |
94 inline void set_range_of_words (idx_t beg, idx_t end); |
88 void set_range_of_words (idx_t beg, idx_t end); |
95 inline void clear_range_of_words (idx_t beg, idx_t end); |
89 void clear_range_of_words (idx_t beg, idx_t end); |
96 inline void set_large_range_of_words (idx_t beg, idx_t end); |
90 void set_large_range_of_words (idx_t beg, idx_t end); |
97 inline void clear_large_range_of_words (idx_t beg, idx_t end); |
91 void clear_large_range_of_words (idx_t beg, idx_t end); |
98 |
92 |
99 // The index of the first full word in a range. |
93 // The index of the first full word in a range. |
100 inline idx_t word_index_round_up(idx_t bit) const; |
94 idx_t word_index_round_up(idx_t bit) const; |
101 |
95 |
102 // Verification, statistics. |
96 // Verification, statistics. |
103 void verify_index(idx_t index) const { |
97 void verify_index(idx_t index) const; |
104 assert(index < _size, "BitMap index out of bounds"); |
98 void verify_range(idx_t beg_index, idx_t end_index) const; |
105 } |
99 |
106 |
100 static idx_t* _pop_count_table; |
107 void verify_range(idx_t beg_index, idx_t end_index) const { |
101 static void init_pop_count_table(); |
108 #ifdef ASSERT |
102 static idx_t num_set_bits(bm_word_t w); |
109 assert(beg_index <= end_index, "BitMap range error"); |
103 static idx_t num_set_bits_from_table(unsigned char c); |
110 // Note that [0,0) and [size,size) are both valid ranges. |
|
111 if (end_index != _size) verify_index(end_index); |
|
112 #endif |
|
113 } |
|
114 |
104 |
115 public: |
105 public: |
116 |
106 |
117 // Constructs a bitmap with no map, and size 0. |
107 // Constructs a bitmap with no map, and size 0. |
118 BitMap() : _map(NULL), _size(0) {} |
108 BitMap() : _map(NULL), _size(0) {} |
119 |
109 |
120 // Construction |
110 // Constructs a bitmap with the given map and size. |
121 BitMap(idx_t* map, idx_t size_in_bits); |
111 BitMap(bm_word_t* map, idx_t size_in_bits); |
122 |
112 |
123 // Allocates necessary data structure in resource area |
113 // Constructs an empty bitmap of the given size (that is, this clears the |
124 BitMap(idx_t size_in_bits); |
114 // new bitmap). Allocates the map array in resource area if |
125 |
115 // "in_resource_area" is true, else in the C heap. |
126 void set_map(idx_t* map) { _map = map; } |
116 BitMap(idx_t size_in_bits, bool in_resource_area = true); |
|
117 |
|
118 // Set the map and size. |
|
119 void set_map(bm_word_t* map) { _map = map; } |
127 void set_size(idx_t size_in_bits) { _size = size_in_bits; } |
120 void set_size(idx_t size_in_bits) { _size = size_in_bits; } |
128 |
121 |
129 // Allocates necessary data structure in resource area. |
122 // Allocates necessary data structure, either in the resource area |
|
123 // or in the C heap, as indicated by "in_resource_area." |
130 // Preserves state currently in bit map by copying data. |
124 // Preserves state currently in bit map by copying data. |
131 // Zeros any newly-addressable bits. |
125 // Zeros any newly-addressable bits. |
132 // Does not perform any frees (i.e., of current _map). |
126 // If "in_resource_area" is false, frees the current map. |
133 void resize(idx_t size_in_bits); |
127 // (Note that this assumes that all calls to "resize" on the same BitMap |
|
128 // use the same value for "in_resource_area".) |
|
129 void resize(idx_t size_in_bits, bool in_resource_area = true); |
134 |
130 |
135 // Accessing |
131 // Accessing |
136 idx_t size() const { return _size; } |
132 idx_t size() const { return _size; } |
137 idx_t size_in_words() const { |
133 idx_t size_in_words() const { |
138 return word_index(size() + BitsPerWord - 1); |
134 return word_index(size() + BitsPerWord - 1); |
181 void par_at_put_large_range(idx_t beg, idx_t end, bool value); |
177 void par_at_put_large_range(idx_t beg, idx_t end, bool value); |
182 |
178 |
183 // Update a range of bits, using a hint about the size. Currently only |
179 // Update a range of bits, using a hint about the size. Currently only |
184 // inlines the predominant case of a 1-bit range. Works best when hint is a |
180 // inlines the predominant case of a 1-bit range. Works best when hint is a |
185 // compile-time constant. |
181 // compile-time constant. |
186 inline void set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
182 void set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
187 inline void clear_range(idx_t beg, idx_t end, RangeSizeHint hint); |
183 void clear_range(idx_t beg, idx_t end, RangeSizeHint hint); |
188 inline void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
184 void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
189 inline void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint); |
185 void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint); |
|
186 |
|
187 // It performs the union operation between subsets of equal length |
|
188 // of two bitmaps (the target bitmap of the method and the |
|
189 // from_bitmap) and stores the result to the target bitmap. The |
|
190 // from_start_index represents the first bit index of the subrange |
|
191 // of the from_bitmap. The to_start_index is the equivalent of the |
|
192 // target bitmap. Both indexes should be word-aligned, i.e. they |
|
193 // should correspond to the first bit on a bitmap word (it's up to |
|
194 // the caller to ensure this; the method does check it). The length |
|
195 // of the subset is specified with word_num and it is in number of |
|
196 // bitmap words. The caller should ensure that this is at least 2 |
|
197 // (smaller ranges are not support to save extra checks). Again, |
|
198 // this is checked in the method. |
|
199 // |
|
200 // Atomicity concerns: it is assumed that any contention on the |
|
201 // target bitmap with other threads will happen on the first and |
|
202 // last words; the ones in between will be "owned" exclusively by |
|
203 // the calling thread and, in fact, they will already be 0. So, the |
|
204 // method performs a CAS on the first word, copies the next |
|
205 // word_num-2 words, and finally performs a CAS on the last word. |
|
206 void mostly_disjoint_range_union(BitMap* from_bitmap, |
|
207 idx_t from_start_index, |
|
208 idx_t to_start_index, |
|
209 size_t word_num); |
|
210 |
190 |
211 |
191 // Clearing |
212 // Clearing |
192 void clear(); |
|
193 void clear_large(); |
213 void clear_large(); |
194 |
214 inline void clear(); |
195 // Iteration support |
215 |
196 void iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex); |
216 // Iteration support. Returns "true" if the iteration completed, false |
197 inline void iterate(BitMapClosure* blk) { |
217 // if the iteration terminated early (because the closure "blk" returned |
|
218 // false). |
|
219 bool iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex); |
|
220 bool iterate(BitMapClosure* blk) { |
198 // call the version that takes an interval |
221 // call the version that takes an interval |
199 iterate(blk, 0, size()); |
222 return iterate(blk, 0, size()); |
200 } |
223 } |
201 |
224 |
202 // Looking for 1's and 0's to the "right" |
225 // Looking for 1's and 0's at indices equal to or greater than "l_index", |
|
226 // stopping if none has been found before "r_index", and returning |
|
227 // "r_index" (which must be at most "size") in that case. |
|
228 idx_t get_next_one_offset_inline (idx_t l_index, idx_t r_index) const; |
|
229 idx_t get_next_zero_offset_inline(idx_t l_index, idx_t r_index) const; |
|
230 |
|
231 // Like "get_next_one_offset_inline", except requires that "r_index" is |
|
232 // aligned to bitsizeof(bm_word_t). |
|
233 idx_t get_next_one_offset_inline_aligned_right(idx_t l_index, |
|
234 idx_t r_index) const; |
|
235 |
|
236 // Non-inline versionsof the above. |
203 idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const; |
237 idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const; |
204 idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const; |
238 idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const; |
205 |
239 |
206 idx_t get_next_one_offset(idx_t offset) const { |
240 idx_t get_next_one_offset(idx_t offset) const { |
207 return get_next_one_offset(offset, size()); |
241 return get_next_one_offset(offset, size()); |
208 } |
242 } |
209 idx_t get_next_zero_offset(idx_t offset) const { |
243 idx_t get_next_zero_offset(idx_t offset) const { |
210 return get_next_zero_offset(offset, size()); |
244 return get_next_zero_offset(offset, size()); |
211 } |
245 } |
212 |
246 |
213 |
247 // Returns the number of bits set in the bitmap. |
214 |
248 idx_t count_one_bits() const; |
215 // Find the next one bit in the range [beg_bit, end_bit), or return end_bit if |
|
216 // no one bit is found. Equivalent to get_next_one_offset(), but inline for |
|
217 // use in performance-critical code. |
|
218 inline idx_t find_next_one_bit(idx_t beg_bit, idx_t end_bit) const; |
|
219 |
249 |
220 // Set operations. |
250 // Set operations. |
221 void set_union(BitMap bits); |
251 void set_union(BitMap bits); |
222 void set_difference(BitMap bits); |
252 void set_difference(BitMap bits); |
223 void set_intersection(BitMap bits); |
253 void set_intersection(BitMap bits); |
246 // Printing |
285 // Printing |
247 void print_on(outputStream* st) const; |
286 void print_on(outputStream* st) const; |
248 #endif |
287 #endif |
249 }; |
288 }; |
250 |
289 |
251 inline void BitMap::set_bit(idx_t bit) { |
|
252 verify_index(bit); |
|
253 *word_addr(bit) |= bit_mask(bit); |
|
254 } |
|
255 |
|
256 inline void BitMap::clear_bit(idx_t bit) { |
|
257 verify_index(bit); |
|
258 *word_addr(bit) &= ~bit_mask(bit); |
|
259 } |
|
260 |
|
261 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) { |
|
262 if (hint == small_range && end - beg == 1) { |
|
263 set_bit(beg); |
|
264 } else { |
|
265 if (hint == large_range) { |
|
266 set_large_range(beg, end); |
|
267 } else { |
|
268 set_range(beg, end); |
|
269 } |
|
270 } |
|
271 } |
|
272 |
|
273 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) { |
|
274 if (hint == small_range && end - beg == 1) { |
|
275 clear_bit(beg); |
|
276 } else { |
|
277 if (hint == large_range) { |
|
278 clear_large_range(beg, end); |
|
279 } else { |
|
280 clear_range(beg, end); |
|
281 } |
|
282 } |
|
283 } |
|
284 |
|
285 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) { |
|
286 if (hint == small_range && end - beg == 1) { |
|
287 par_at_put(beg, true); |
|
288 } else { |
|
289 if (hint == large_range) { |
|
290 par_at_put_large_range(beg, end, true); |
|
291 } else { |
|
292 par_at_put_range(beg, end, true); |
|
293 } |
|
294 } |
|
295 } |
|
296 |
|
297 |
290 |
298 // Convenience class wrapping BitMap which provides multiple bits per slot. |
291 // Convenience class wrapping BitMap which provides multiple bits per slot. |
299 class BitMap2D VALUE_OBJ_CLASS_SPEC { |
292 class BitMap2D VALUE_OBJ_CLASS_SPEC { |
300 public: |
293 public: |
301 typedef size_t idx_t; // Type used for bit and word indices. |
294 typedef BitMap::idx_t idx_t; // Type used for bit and word indices. |
302 |
295 typedef BitMap::bm_word_t bm_word_t; // Element type of array that |
|
296 // represents the bitmap. |
303 private: |
297 private: |
304 BitMap _map; |
298 BitMap _map; |
305 idx_t _bits_per_slot; |
299 idx_t _bits_per_slot; |
306 |
300 |
307 idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const { |
301 idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const { |
357 void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) { |
351 void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) { |
358 verify_bit_within_slot_index(bit_within_slot_index); |
352 verify_bit_within_slot_index(bit_within_slot_index); |
359 _map.at_put_grow(bit_index(slot_index, bit_within_slot_index), value); |
353 _map.at_put_grow(bit_index(slot_index, bit_within_slot_index), value); |
360 } |
354 } |
361 |
355 |
362 void clear() { |
356 void clear(); |
363 _map.clear(); |
|
364 } |
|
365 }; |
357 }; |
366 |
358 |
367 |
359 // Closure for iterating over BitMaps |
368 |
360 |
369 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) { |
361 class BitMapClosure VALUE_OBJ_CLASS_SPEC { |
370 uintptr_t* map = _map; |
362 public: |
371 for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0; |
363 // Callback when bit in map is set. Should normally return "true"; |
372 } |
364 // return of false indicates that the bitmap iteration should terminate. |
373 |
365 virtual bool do_bit(BitMap::idx_t offset) = 0; |
374 |
366 }; |
375 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) { |
|
376 uintptr_t* map = _map; |
|
377 for (idx_t i = beg; i < end; ++i) map[i] = 0; |
|
378 } |
|
379 |
|
380 |
|
381 inline void BitMap::clear() { |
|
382 clear_range_of_words(0, size_in_words()); |
|
383 } |
|
384 |
|
385 |
|
386 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) { |
|
387 if (hint == small_range && end - beg == 1) { |
|
388 par_at_put(beg, false); |
|
389 } else { |
|
390 if (hint == large_range) { |
|
391 par_at_put_large_range(beg, end, false); |
|
392 } else { |
|
393 par_at_put_range(beg, end, false); |
|
394 } |
|
395 } |
|
396 } |
|