Fri, 16 Aug 2013 14:11:40 -0700
8021898: Broken JIT compiler optimization for loop unswitching
Summary: fix method clone_projs() to clone all related MachProj nodes.
Reviewed-by: roland, adlertz
1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "utilities/bitMap.inline.hpp"
28 #include "utilities/copy.hpp"
29 #ifdef TARGET_OS_FAMILY_linux
30 # include "os_linux.inline.hpp"
31 #endif
32 #ifdef TARGET_OS_FAMILY_solaris
33 # include "os_solaris.inline.hpp"
34 #endif
35 #ifdef TARGET_OS_FAMILY_windows
36 # include "os_windows.inline.hpp"
37 #endif
38 #ifdef TARGET_OS_FAMILY_bsd
39 # include "os_bsd.inline.hpp"
40 #endif
43 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
44 _map(map), _size(size_in_bits), _map_allocator(false)
45 {
46 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
47 assert(size_in_bits >= 0, "just checking");
48 }
51 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
52 _map(NULL), _size(0), _map_allocator(false)
53 {
54 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
55 resize(size_in_bits, in_resource_area);
56 }
58 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
59 assert(size_in_bits >= 0, "just checking");
60 idx_t old_size_in_words = size_in_words();
61 bm_word_t* old_map = map();
63 _size = size_in_bits;
64 idx_t new_size_in_words = size_in_words();
65 if (in_resource_area) {
66 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
67 } else {
68 if (old_map != NULL) {
69 _map_allocator.free();
70 }
71 _map = _map_allocator.allocate(new_size_in_words);
72 }
73 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
74 MIN2(old_size_in_words, new_size_in_words));
75 if (new_size_in_words > old_size_in_words) {
76 clear_range_of_words(old_size_in_words, size_in_words());
77 }
78 }
80 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
81 // With a valid range (beg <= end), this test ensures that end != 0, as
82 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
83 if (beg != end) {
84 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
85 *word_addr(beg) |= ~mask;
86 }
87 }
89 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
90 // With a valid range (beg <= end), this test ensures that end != 0, as
91 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
92 if (beg != end) {
93 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
94 *word_addr(beg) &= mask;
95 }
96 }
98 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
99 assert(value == 0 || value == 1, "0 for clear, 1 for set");
100 // With a valid range (beg <= end), this test ensures that end != 0, as
101 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
102 if (beg != end) {
103 intptr_t* pw = (intptr_t*)word_addr(beg);
104 intptr_t w = *pw;
105 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
106 intptr_t nw = value ? (w | ~mr) : (w & mr);
107 while (true) {
108 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
109 if (res == w) break;
110 w = *pw;
111 nw = value ? (w | ~mr) : (w & mr);
112 }
113 }
114 }
116 void BitMap::set_range(idx_t beg, idx_t end) {
117 verify_range(beg, end);
119 idx_t beg_full_word = word_index_round_up(beg);
120 idx_t end_full_word = word_index(end);
122 if (beg_full_word < end_full_word) {
123 // The range includes at least one full word.
124 set_range_within_word(beg, bit_index(beg_full_word));
125 set_range_of_words(beg_full_word, end_full_word);
126 set_range_within_word(bit_index(end_full_word), end);
127 } else {
128 // The range spans at most 2 partial words.
129 idx_t boundary = MIN2(bit_index(beg_full_word), end);
130 set_range_within_word(beg, boundary);
131 set_range_within_word(boundary, end);
132 }
133 }
135 void BitMap::clear_range(idx_t beg, idx_t end) {
136 verify_range(beg, end);
138 idx_t beg_full_word = word_index_round_up(beg);
139 idx_t end_full_word = word_index(end);
141 if (beg_full_word < end_full_word) {
142 // The range includes at least one full word.
143 clear_range_within_word(beg, bit_index(beg_full_word));
144 clear_range_of_words(beg_full_word, end_full_word);
145 clear_range_within_word(bit_index(end_full_word), end);
146 } else {
147 // The range spans at most 2 partial words.
148 idx_t boundary = MIN2(bit_index(beg_full_word), end);
149 clear_range_within_word(beg, boundary);
150 clear_range_within_word(boundary, end);
151 }
152 }
154 void BitMap::set_large_range(idx_t beg, idx_t end) {
155 verify_range(beg, end);
157 idx_t beg_full_word = word_index_round_up(beg);
158 idx_t end_full_word = word_index(end);
160 assert(end_full_word - beg_full_word >= 32,
161 "the range must include at least 32 bytes");
163 // The range includes at least one full word.
164 set_range_within_word(beg, bit_index(beg_full_word));
165 set_large_range_of_words(beg_full_word, end_full_word);
166 set_range_within_word(bit_index(end_full_word), end);
167 }
169 void BitMap::clear_large_range(idx_t beg, idx_t end) {
170 verify_range(beg, end);
172 idx_t beg_full_word = word_index_round_up(beg);
173 idx_t end_full_word = word_index(end);
175 assert(end_full_word - beg_full_word >= 32,
176 "the range must include at least 32 bytes");
178 // The range includes at least one full word.
179 clear_range_within_word(beg, bit_index(beg_full_word));
180 clear_large_range_of_words(beg_full_word, end_full_word);
181 clear_range_within_word(bit_index(end_full_word), end);
182 }
184 void BitMap::at_put(idx_t offset, bool value) {
185 if (value) {
186 set_bit(offset);
187 } else {
188 clear_bit(offset);
189 }
190 }
192 // Return true to indicate that this thread changed
193 // the bit, false to indicate that someone else did.
194 // In either case, the requested bit is in the
195 // requested state some time during the period that
196 // this thread is executing this call. More importantly,
197 // if no other thread is executing an action to
198 // change the requested bit to a state other than
199 // the one that this thread is trying to set it to,
200 // then the the bit is in the expected state
201 // at exit from this method. However, rather than
202 // make such a strong assertion here, based on
203 // assuming such constrained use (which though true
204 // today, could change in the future to service some
205 // funky parallel algorithm), we encourage callers
206 // to do such verification, as and when appropriate.
207 bool BitMap::par_at_put(idx_t bit, bool value) {
208 return value ? par_set_bit(bit) : par_clear_bit(bit);
209 }
211 void BitMap::at_put_grow(idx_t offset, bool value) {
212 if (offset >= size()) {
213 resize(2 * MAX2(size(), offset));
214 }
215 at_put(offset, value);
216 }
218 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
219 if (value) {
220 set_range(start_offset, end_offset);
221 } else {
222 clear_range(start_offset, end_offset);
223 }
224 }
226 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
227 verify_range(beg, end);
229 idx_t beg_full_word = word_index_round_up(beg);
230 idx_t end_full_word = word_index(end);
232 if (beg_full_word < end_full_word) {
233 // The range includes at least one full word.
234 par_put_range_within_word(beg, bit_index(beg_full_word), value);
235 if (value) {
236 set_range_of_words(beg_full_word, end_full_word);
237 } else {
238 clear_range_of_words(beg_full_word, end_full_word);
239 }
240 par_put_range_within_word(bit_index(end_full_word), end, value);
241 } else {
242 // The range spans at most 2 partial words.
243 idx_t boundary = MIN2(bit_index(beg_full_word), end);
244 par_put_range_within_word(beg, boundary, value);
245 par_put_range_within_word(boundary, end, value);
246 }
248 }
250 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
251 if (value) {
252 set_large_range(beg, end);
253 } else {
254 clear_large_range(beg, end);
255 }
256 }
258 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
259 verify_range(beg, end);
261 idx_t beg_full_word = word_index_round_up(beg);
262 idx_t end_full_word = word_index(end);
264 assert(end_full_word - beg_full_word >= 32,
265 "the range must include at least 32 bytes");
267 // The range includes at least one full word.
268 par_put_range_within_word(beg, bit_index(beg_full_word), value);
269 if (value) {
270 set_large_range_of_words(beg_full_word, end_full_word);
271 } else {
272 clear_large_range_of_words(beg_full_word, end_full_word);
273 }
274 par_put_range_within_word(bit_index(end_full_word), end, value);
275 }
277 bool BitMap::contains(const BitMap other) const {
278 assert(size() == other.size(), "must have same size");
279 bm_word_t* dest_map = map();
280 bm_word_t* other_map = other.map();
281 idx_t size = size_in_words();
282 for (idx_t index = 0; index < size_in_words(); index++) {
283 bm_word_t word_union = dest_map[index] | other_map[index];
284 // If this has more bits set than dest_map[index], then other is not a
285 // subset.
286 if (word_union != dest_map[index]) return false;
287 }
288 return true;
289 }
291 bool BitMap::intersects(const BitMap other) const {
292 assert(size() == other.size(), "must have same size");
293 bm_word_t* dest_map = map();
294 bm_word_t* other_map = other.map();
295 idx_t size = size_in_words();
296 for (idx_t index = 0; index < size_in_words(); index++) {
297 if ((dest_map[index] & other_map[index]) != 0) return true;
298 }
299 // Otherwise, no intersection.
300 return false;
301 }
303 void BitMap::set_union(BitMap other) {
304 assert(size() == other.size(), "must have same size");
305 bm_word_t* dest_map = map();
306 bm_word_t* other_map = other.map();
307 idx_t size = size_in_words();
308 for (idx_t index = 0; index < size_in_words(); index++) {
309 dest_map[index] = dest_map[index] | other_map[index];
310 }
311 }
314 void BitMap::set_difference(BitMap other) {
315 assert(size() == other.size(), "must have same size");
316 bm_word_t* dest_map = map();
317 bm_word_t* other_map = other.map();
318 idx_t size = size_in_words();
319 for (idx_t index = 0; index < size_in_words(); index++) {
320 dest_map[index] = dest_map[index] & ~(other_map[index]);
321 }
322 }
325 void BitMap::set_intersection(BitMap other) {
326 assert(size() == other.size(), "must have same size");
327 bm_word_t* dest_map = map();
328 bm_word_t* other_map = other.map();
329 idx_t size = size_in_words();
330 for (idx_t index = 0; index < size; index++) {
331 dest_map[index] = dest_map[index] & other_map[index];
332 }
333 }
336 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
337 assert(other.size() >= offset, "offset not in range");
338 assert(other.size() - offset >= size(), "other not large enough");
339 // XXX Ideally, we would remove this restriction.
340 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
341 "Only handle aligned cases so far.");
342 bm_word_t* dest_map = map();
343 bm_word_t* other_map = other.map();
344 idx_t offset_word_ind = word_index(offset);
345 idx_t size = size_in_words();
346 for (idx_t index = 0; index < size; index++) {
347 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
348 }
349 }
351 bool BitMap::set_union_with_result(BitMap other) {
352 assert(size() == other.size(), "must have same size");
353 bool changed = false;
354 bm_word_t* dest_map = map();
355 bm_word_t* other_map = other.map();
356 idx_t size = size_in_words();
357 for (idx_t index = 0; index < size; index++) {
358 idx_t temp = map(index) | other_map[index];
359 changed = changed || (temp != map(index));
360 map()[index] = temp;
361 }
362 return changed;
363 }
366 bool BitMap::set_difference_with_result(BitMap other) {
367 assert(size() == other.size(), "must have same size");
368 bool changed = false;
369 bm_word_t* dest_map = map();
370 bm_word_t* other_map = other.map();
371 idx_t size = size_in_words();
372 for (idx_t index = 0; index < size; index++) {
373 bm_word_t temp = dest_map[index] & ~(other_map[index]);
374 changed = changed || (temp != dest_map[index]);
375 dest_map[index] = temp;
376 }
377 return changed;
378 }
381 bool BitMap::set_intersection_with_result(BitMap other) {
382 assert(size() == other.size(), "must have same size");
383 bool changed = false;
384 bm_word_t* dest_map = map();
385 bm_word_t* other_map = other.map();
386 idx_t size = size_in_words();
387 for (idx_t index = 0; index < size; index++) {
388 bm_word_t orig = dest_map[index];
389 bm_word_t temp = orig & other_map[index];
390 changed = changed || (temp != orig);
391 dest_map[index] = temp;
392 }
393 return changed;
394 }
397 void BitMap::set_from(BitMap other) {
398 assert(size() == other.size(), "must have same size");
399 bm_word_t* dest_map = map();
400 bm_word_t* other_map = other.map();
401 idx_t size = size_in_words();
402 for (idx_t index = 0; index < size; index++) {
403 dest_map[index] = other_map[index];
404 }
405 }
408 bool BitMap::is_same(BitMap other) {
409 assert(size() == other.size(), "must have same size");
410 bm_word_t* dest_map = map();
411 bm_word_t* other_map = other.map();
412 idx_t size = size_in_words();
413 for (idx_t index = 0; index < size; index++) {
414 if (dest_map[index] != other_map[index]) return false;
415 }
416 return true;
417 }
419 bool BitMap::is_full() const {
420 bm_word_t* word = map();
421 idx_t rest = size();
422 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
423 if (*word != (bm_word_t) AllBits) return false;
424 word++;
425 }
426 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
427 }
430 bool BitMap::is_empty() const {
431 bm_word_t* word = map();
432 idx_t rest = size();
433 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
434 if (*word != (bm_word_t) NoBits) return false;
435 word++;
436 }
437 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
438 }
440 void BitMap::clear_large() {
441 clear_large_range_of_words(0, size_in_words());
442 }
444 // Note that if the closure itself modifies the bitmap
445 // then modifications in and to the left of the _bit_ being
446 // currently sampled will not be seen. Note also that the
447 // interval [leftOffset, rightOffset) is right open.
448 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
449 verify_range(leftOffset, rightOffset);
451 idx_t startIndex = word_index(leftOffset);
452 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
453 for (idx_t index = startIndex, offset = leftOffset;
454 offset < rightOffset && index < endIndex;
455 offset = (++index) << LogBitsPerWord) {
456 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
457 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
458 if (rest & 1) {
459 if (!blk->do_bit(offset)) return false;
460 // resample at each closure application
461 // (see, for instance, CMS bug 4525989)
462 rest = map(index) >> (offset & (BitsPerWord -1));
463 }
464 rest = rest >> 1;
465 }
466 }
467 return true;
468 }
470 BitMap::idx_t* BitMap::_pop_count_table = NULL;
472 void BitMap::init_pop_count_table() {
473 if (_pop_count_table == NULL) {
474 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
475 for (uint i = 0; i < 256; i++) {
476 table[i] = num_set_bits(i);
477 }
479 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table,
480 (intptr_t*) &_pop_count_table,
481 (intptr_t) NULL_WORD);
482 if (res != NULL_WORD) {
483 guarantee( _pop_count_table == (void*) res, "invariant" );
484 FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal);
485 }
486 }
487 }
489 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
490 idx_t bits = 0;
492 while (w != 0) {
493 while ((w & 1) == 0) {
494 w >>= 1;
495 }
496 bits++;
497 w >>= 1;
498 }
499 return bits;
500 }
502 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
503 assert(_pop_count_table != NULL, "precondition");
504 return _pop_count_table[c];
505 }
507 BitMap::idx_t BitMap::count_one_bits() const {
508 init_pop_count_table(); // If necessary.
509 idx_t sum = 0;
510 typedef unsigned char uchar;
511 for (idx_t i = 0; i < size_in_words(); i++) {
512 bm_word_t w = map()[i];
513 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
514 sum += num_set_bits_from_table(uchar(w & 255));
515 w >>= 8;
516 }
517 }
518 return sum;
519 }
521 void BitMap::print_on_error(outputStream* st, const char* prefix) const {
522 st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")",
523 prefix, map(), (char*)map() + (size() >> LogBitsPerByte));
524 }
526 #ifndef PRODUCT
528 void BitMap::print_on(outputStream* st) const {
529 tty->print("Bitmap(%d):", size());
530 for (idx_t index = 0; index < size(); index++) {
531 tty->print("%c", at(index) ? '1' : '0');
532 }
533 tty->cr();
534 }
536 #endif
539 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
540 : _bits_per_slot(bits_per_slot)
541 , _map(map, size_in_slots * bits_per_slot)
542 {
543 }
546 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
547 : _bits_per_slot(bits_per_slot)
548 , _map(size_in_slots * bits_per_slot)
549 {
550 }