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annotate src/share/vm/c1/c1_ValueMap.cpp @ 4597:8bc6f680a88d
fixed visual studio project files
author | Christian Haeubl <christian.haeubl@oracle.com> |
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date | Tue, 14 Feb 2012 15:01:36 -0800 |
parents | f95d63e2154a |
children | f067b4e0e04b |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "c1/c1_Canonicalizer.hpp" | |
27 #include "c1/c1_IR.hpp" | |
28 #include "c1/c1_ValueMap.hpp" | |
29 #include "utilities/bitMap.inline.hpp" | |
0 | 30 |
31 | |
32 #ifndef PRODUCT | |
33 | |
34 int ValueMap::_number_of_finds = 0; | |
35 int ValueMap::_number_of_hits = 0; | |
36 int ValueMap::_number_of_kills = 0; | |
37 | |
38 #define TRACE_VALUE_NUMBERING(code) if (PrintValueNumbering) { code; } | |
39 | |
40 #else | |
41 | |
42 #define TRACE_VALUE_NUMBERING(code) | |
43 | |
44 #endif | |
45 | |
46 | |
47 ValueMap::ValueMap() | |
48 : _nesting(0) | |
49 , _entries(ValueMapInitialSize, NULL) | |
50 , _killed_values() | |
51 , _entry_count(0) | |
52 { | |
53 NOT_PRODUCT(reset_statistics()); | |
54 } | |
55 | |
56 | |
57 ValueMap::ValueMap(ValueMap* old) | |
58 : _nesting(old->_nesting + 1) | |
59 , _entries(old->_entries.length()) | |
60 , _killed_values() | |
61 , _entry_count(old->_entry_count) | |
62 { | |
63 for (int i = size() - 1; i >= 0; i--) { | |
64 _entries.at_put(i, old->entry_at(i)); | |
65 } | |
66 _killed_values.set_from(&old->_killed_values); | |
67 } | |
68 | |
69 | |
70 void ValueMap::increase_table_size() { | |
71 int old_size = size(); | |
72 int new_size = old_size * 2 + 1; | |
73 | |
74 ValueMapEntryList worklist(8); | |
75 ValueMapEntryArray new_entries(new_size, NULL); | |
76 int new_entry_count = 0; | |
77 | |
78 TRACE_VALUE_NUMBERING(tty->print_cr("increasing table size from %d to %d", old_size, new_size)); | |
79 | |
80 for (int i = old_size - 1; i >= 0; i--) { | |
81 ValueMapEntry* entry; | |
82 for (entry = entry_at(i); entry != NULL; entry = entry->next()) { | |
83 if (!is_killed(entry->value())) { | |
84 worklist.push(entry); | |
85 } | |
86 } | |
87 | |
88 while (!worklist.is_empty()) { | |
89 entry = worklist.pop(); | |
90 int new_index = entry_index(entry->hash(), new_size); | |
91 | |
92 if (entry->nesting() != nesting() && new_entries.at(new_index) != entry->next()) { | |
93 // changing entries with a lower nesting than the current nesting of the table | |
94 // is not allowed because then the same entry is contained in multiple value maps. | |
95 // clone entry when next-pointer must be changed | |
96 entry = new ValueMapEntry(entry->hash(), entry->value(), entry->nesting(), NULL); | |
97 } | |
98 entry->set_next(new_entries.at(new_index)); | |
99 new_entries.at_put(new_index, entry); | |
100 new_entry_count++; | |
101 } | |
102 } | |
103 | |
104 _entries = new_entries; | |
105 _entry_count = new_entry_count; | |
106 } | |
107 | |
108 | |
109 Value ValueMap::find_insert(Value x) { | |
110 const intx hash = x->hash(); | |
111 if (hash != 0) { | |
112 // 0 hash means: exclude from value numbering | |
113 NOT_PRODUCT(_number_of_finds++); | |
114 | |
115 for (ValueMapEntry* entry = entry_at(entry_index(hash, size())); entry != NULL; entry = entry->next()) { | |
116 if (entry->hash() == hash) { | |
117 Value f = entry->value(); | |
118 | |
119 if (!is_killed(f) && f->is_equal(x)) { | |
120 NOT_PRODUCT(_number_of_hits++); | |
121 TRACE_VALUE_NUMBERING(tty->print_cr("Value Numbering: %s %c%d equal to %c%d (size %d, entries %d, nesting-diff %d)", x->name(), x->type()->tchar(), x->id(), f->type()->tchar(), f->id(), size(), entry_count(), nesting() - entry->nesting())); | |
122 | |
123 if (entry->nesting() != nesting() && f->as_Constant() == NULL) { | |
124 // non-constant values of of another block must be pinned, | |
125 // otherwise it is possible that they are not evaluated | |
126 f->pin(Instruction::PinGlobalValueNumbering); | |
127 } | |
128 | |
129 return f; | |
130 | |
131 } | |
132 } | |
133 } | |
134 | |
135 // x not found, so insert it | |
136 if (entry_count() >= size_threshold()) { | |
137 increase_table_size(); | |
138 } | |
139 int idx = entry_index(hash, size()); | |
140 _entries.at_put(idx, new ValueMapEntry(hash, x, nesting(), entry_at(idx))); | |
141 _entry_count++; | |
142 | |
143 TRACE_VALUE_NUMBERING(tty->print_cr("Value Numbering: insert %s %c%d (size %d, entries %d, nesting %d)", x->name(), x->type()->tchar(), x->id(), size(), entry_count(), nesting())); | |
144 } | |
145 | |
146 return x; | |
147 } | |
148 | |
149 | |
150 #define GENERIC_KILL_VALUE(must_kill_implementation) \ | |
151 NOT_PRODUCT(_number_of_kills++); \ | |
152 \ | |
153 for (int i = size() - 1; i >= 0; i--) { \ | |
154 ValueMapEntry* prev_entry = NULL; \ | |
155 for (ValueMapEntry* entry = entry_at(i); entry != NULL; entry = entry->next()) { \ | |
156 Value value = entry->value(); \ | |
157 \ | |
158 must_kill_implementation(must_kill, entry, value) \ | |
159 \ | |
160 if (must_kill) { \ | |
161 kill_value(value); \ | |
162 \ | |
163 if (prev_entry == NULL) { \ | |
164 _entries.at_put(i, entry->next()); \ | |
165 _entry_count--; \ | |
166 } else if (prev_entry->nesting() == nesting()) { \ | |
167 prev_entry->set_next(entry->next()); \ | |
168 _entry_count--; \ | |
169 } else { \ | |
170 prev_entry = entry; \ | |
171 } \ | |
172 \ | |
173 TRACE_VALUE_NUMBERING(tty->print_cr("Value Numbering: killed %s %c%d (size %d, entries %d, nesting-diff %d)", value->name(), value->type()->tchar(), value->id(), size(), entry_count(), nesting() - entry->nesting())); \ | |
174 } else { \ | |
175 prev_entry = entry; \ | |
176 } \ | |
177 } \ | |
178 } \ | |
179 | |
180 #define MUST_KILL_MEMORY(must_kill, entry, value) \ | |
181 bool must_kill = value->as_LoadField() != NULL || value->as_LoadIndexed() != NULL; | |
182 | |
183 #define MUST_KILL_ARRAY(must_kill, entry, value) \ | |
184 bool must_kill = value->as_LoadIndexed() != NULL \ | |
185 && value->type()->tag() == type->tag(); | |
186 | |
187 #define MUST_KILL_FIELD(must_kill, entry, value) \ | |
188 /* ciField's are not unique; must compare their contents */ \ | |
189 LoadField* lf = value->as_LoadField(); \ | |
190 bool must_kill = lf != NULL \ | |
191 && lf->field()->holder() == field->holder() \ | |
192 && lf->field()->offset() == field->offset(); | |
193 | |
194 #define MUST_KILL_EXCEPTION(must_kill, entry, value) \ | |
195 assert(entry->nesting() < nesting(), "must not find bigger nesting than current"); \ | |
196 bool must_kill = (entry->nesting() == nesting() - 1); | |
197 | |
198 | |
199 void ValueMap::kill_memory() { | |
200 GENERIC_KILL_VALUE(MUST_KILL_MEMORY); | |
201 } | |
202 | |
203 void ValueMap::kill_array(ValueType* type) { | |
204 GENERIC_KILL_VALUE(MUST_KILL_ARRAY); | |
205 } | |
206 | |
207 void ValueMap::kill_field(ciField* field) { | |
208 GENERIC_KILL_VALUE(MUST_KILL_FIELD); | |
209 } | |
210 | |
211 void ValueMap::kill_exception() { | |
212 GENERIC_KILL_VALUE(MUST_KILL_EXCEPTION); | |
213 } | |
214 | |
215 | |
216 void ValueMap::kill_map(ValueMap* map) { | |
217 assert(is_global_value_numbering(), "only for global value numbering"); | |
218 _killed_values.set_union(&map->_killed_values); | |
219 } | |
220 | |
221 void ValueMap::kill_all() { | |
222 assert(is_local_value_numbering(), "only for local value numbering"); | |
223 for (int i = size() - 1; i >= 0; i--) { | |
224 _entries.at_put(i, NULL); | |
225 } | |
226 _entry_count = 0; | |
227 } | |
228 | |
229 | |
230 #ifndef PRODUCT | |
231 | |
232 void ValueMap::print() { | |
233 tty->print_cr("(size %d, entries %d, nesting %d)", size(), entry_count(), nesting()); | |
234 | |
235 int entries = 0; | |
236 for (int i = 0; i < size(); i++) { | |
237 if (entry_at(i) != NULL) { | |
238 tty->print(" %2d: ", i); | |
239 for (ValueMapEntry* entry = entry_at(i); entry != NULL; entry = entry->next()) { | |
240 Value value = entry->value(); | |
241 tty->print("%s %c%d (%s%d) -> ", value->name(), value->type()->tchar(), value->id(), is_killed(value) ? "x" : "", entry->nesting()); | |
242 entries++; | |
243 } | |
244 tty->print_cr("NULL"); | |
245 } | |
246 } | |
247 | |
248 _killed_values.print(); | |
249 assert(entry_count() == entries, "entry_count incorrect"); | |
250 } | |
251 | |
252 void ValueMap::reset_statistics() { | |
253 _number_of_finds = 0; | |
254 _number_of_hits = 0; | |
255 _number_of_kills = 0; | |
256 } | |
257 | |
258 void ValueMap::print_statistics() { | |
259 float hit_rate = 0; | |
260 if (_number_of_finds != 0) { | |
261 hit_rate = (float)_number_of_hits / _number_of_finds; | |
262 } | |
263 | |
264 tty->print_cr("finds:%3d hits:%3d kills:%3d hit rate: %1.4f", _number_of_finds, _number_of_hits, _number_of_kills, hit_rate); | |
265 } | |
266 | |
267 #endif | |
268 | |
269 | |
270 | |
271 class ShortLoopOptimizer : public ValueNumberingVisitor { | |
272 private: | |
273 GlobalValueNumbering* _gvn; | |
274 BlockList _loop_blocks; | |
275 bool _too_complicated_loop; | |
276 | |
277 // simplified access to methods of GlobalValueNumbering | |
278 ValueMap* current_map() { return _gvn->current_map(); } | |
279 ValueMap* value_map_of(BlockBegin* block) { return _gvn->value_map_of(block); } | |
280 | |
281 // implementation for abstract methods of ValueNumberingVisitor | |
282 void kill_memory() { _too_complicated_loop = true; } | |
283 void kill_field(ciField* field) { current_map()->kill_field(field); }; | |
284 void kill_array(ValueType* type) { current_map()->kill_array(type); }; | |
285 | |
286 public: | |
287 ShortLoopOptimizer(GlobalValueNumbering* gvn) | |
288 : _gvn(gvn) | |
289 , _loop_blocks(ValueMapMaxLoopSize) | |
290 , _too_complicated_loop(false) | |
291 { | |
292 } | |
293 | |
294 bool process(BlockBegin* loop_header); | |
295 }; | |
296 | |
297 | |
298 bool ShortLoopOptimizer::process(BlockBegin* loop_header) { | |
299 TRACE_VALUE_NUMBERING(tty->print_cr("** loop header block")); | |
300 | |
301 _too_complicated_loop = false; | |
302 _loop_blocks.clear(); | |
303 _loop_blocks.append(loop_header); | |
304 | |
305 for (int i = 0; i < _loop_blocks.length(); i++) { | |
306 BlockBegin* block = _loop_blocks.at(i); | |
307 TRACE_VALUE_NUMBERING(tty->print_cr("processing loop block B%d", block->block_id())); | |
308 | |
309 if (block->is_set(BlockBegin::exception_entry_flag)) { | |
310 // this would be too complicated | |
311 return false; | |
312 } | |
313 | |
314 // add predecessors to worklist | |
315 for (int j = block->number_of_preds() - 1; j >= 0; j--) { | |
316 BlockBegin* pred = block->pred_at(j); | |
317 | |
318 ValueMap* pred_map = value_map_of(pred); | |
319 if (pred_map != NULL) { | |
320 current_map()->kill_map(pred_map); | |
321 } else if (!_loop_blocks.contains(pred)) { | |
322 if (_loop_blocks.length() >= ValueMapMaxLoopSize) { | |
323 return false; | |
324 } | |
325 _loop_blocks.append(pred); | |
326 } | |
327 } | |
328 | |
329 // use the instruction visitor for killing values | |
330 for (Value instr = block->next(); instr != NULL; instr = instr->next()) { | |
331 instr->visit(this); | |
332 if (_too_complicated_loop) { | |
333 return false; | |
334 } | |
335 } | |
336 } | |
337 | |
338 TRACE_VALUE_NUMBERING(tty->print_cr("** loop successfully optimized")); | |
339 return true; | |
340 } | |
341 | |
342 | |
343 GlobalValueNumbering::GlobalValueNumbering(IR* ir) | |
344 : _current_map(NULL) | |
345 , _value_maps(ir->linear_scan_order()->length(), NULL) | |
346 { | |
347 TRACE_VALUE_NUMBERING(tty->print_cr("****** start of global value numbering")); | |
348 | |
349 ShortLoopOptimizer short_loop_optimizer(this); | |
350 int subst_count = 0; | |
351 | |
352 BlockList* blocks = ir->linear_scan_order(); | |
353 int num_blocks = blocks->length(); | |
354 | |
355 BlockBegin* start_block = blocks->at(0); | |
356 assert(start_block == ir->start() && start_block->number_of_preds() == 0 && start_block->dominator() == NULL, "must be start block"); | |
357 assert(start_block->next()->as_Base() != NULL && start_block->next()->next() == NULL, "start block must not have instructions"); | |
358 | |
359 // initial, empty value map with nesting 0 | |
360 set_value_map_of(start_block, new ValueMap()); | |
361 | |
362 for (int i = 1; i < num_blocks; i++) { | |
363 BlockBegin* block = blocks->at(i); | |
364 TRACE_VALUE_NUMBERING(tty->print_cr("**** processing block B%d", block->block_id())); | |
365 | |
366 int num_preds = block->number_of_preds(); | |
367 assert(num_preds > 0, "block must have predecessors"); | |
368 | |
369 BlockBegin* dominator = block->dominator(); | |
370 assert(dominator != NULL, "dominator must exist"); | |
371 assert(value_map_of(dominator) != NULL, "value map of dominator must exist"); | |
372 | |
373 // create new value map with increased nesting | |
374 _current_map = new ValueMap(value_map_of(dominator)); | |
375 | |
376 if (num_preds == 1) { | |
377 assert(dominator == block->pred_at(0), "dominator must be equal to predecessor"); | |
378 // nothing to do here | |
379 | |
380 } else if (block->is_set(BlockBegin::linear_scan_loop_header_flag)) { | |
381 // block has incoming backward branches -> try to optimize short loops | |
382 if (!short_loop_optimizer.process(block)) { | |
383 // loop is too complicated, so kill all memory loads because there might be | |
384 // stores to them in the loop | |
385 current_map()->kill_memory(); | |
386 } | |
387 | |
388 } else { | |
389 // only incoming forward branches that are already processed | |
390 for (int j = 0; j < num_preds; j++) { | |
391 BlockBegin* pred = block->pred_at(j); | |
392 ValueMap* pred_map = value_map_of(pred); | |
393 | |
394 if (pred_map != NULL) { | |
395 // propagate killed values of the predecessor to this block | |
396 current_map()->kill_map(value_map_of(pred)); | |
397 } else { | |
398 // kill all memory loads because predecessor not yet processed | |
399 // (this can happen with non-natural loops and OSR-compiles) | |
400 current_map()->kill_memory(); | |
401 } | |
402 } | |
403 } | |
404 | |
405 if (block->is_set(BlockBegin::exception_entry_flag)) { | |
406 current_map()->kill_exception(); | |
407 } | |
408 | |
409 TRACE_VALUE_NUMBERING(tty->print("value map before processing block: "); current_map()->print()); | |
410 | |
411 // visit all instructions of this block | |
412 for (Value instr = block->next(); instr != NULL; instr = instr->next()) { | |
413 assert(!instr->has_subst(), "substitution already set"); | |
414 | |
415 // check if instruction kills any values | |
416 instr->visit(this); | |
417 | |
418 if (instr->hash() != 0) { | |
419 Value f = current_map()->find_insert(instr); | |
420 if (f != instr) { | |
421 assert(!f->has_subst(), "can't have a substitution"); | |
422 instr->set_subst(f); | |
423 subst_count++; | |
424 } | |
425 } | |
426 } | |
427 | |
428 // remember value map for successors | |
429 set_value_map_of(block, current_map()); | |
430 } | |
431 | |
432 if (subst_count != 0) { | |
433 SubstitutionResolver resolver(ir); | |
434 } | |
435 | |
436 TRACE_VALUE_NUMBERING(tty->print("****** end of global value numbering. "); ValueMap::print_statistics()); | |
437 } |