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annotate src/share/vm/compiler/methodLiveness.cpp @ 4059:44ce519bc3d1
7104960: JSR 292: +VerifyMethodHandles in product JVM can overflow buffer
Reviewed-by: kvn, jrose, twisti
author | never |
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date | Tue, 08 Nov 2011 10:31:53 -0800 |
parents | 8012aa3ccede |
children | 78bbf4d43a14 |
rev | line source |
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0 | 1 /* |
2142 | 2 * Copyright (c) 1998, 2011, 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 "ci/ciMethod.hpp" | |
27 #include "ci/ciMethodBlocks.hpp" | |
28 #include "ci/ciStreams.hpp" | |
29 #include "compiler/methodLiveness.hpp" | |
30 #include "interpreter/bytecode.hpp" | |
31 #include "interpreter/bytecodes.hpp" | |
32 #include "memory/allocation.inline.hpp" | |
33 #include "utilities/bitMap.inline.hpp" | |
34 | |
0 | 35 // The MethodLiveness class performs a simple liveness analysis on a method |
36 // in order to decide which locals are live (that is, will be used again) at | |
37 // a particular bytecode index (bci). | |
38 // | |
39 // The algorithm goes: | |
40 // | |
41 // 1. Break the method into a set of basic blocks. For each basic block we | |
42 // also keep track of its set of predecessors through normal control flow | |
43 // and predecessors through exceptional control flow. | |
44 // | |
45 // 2. For each basic block, compute two sets, gen (the set of values used before | |
46 // they are defined) and kill (the set of values defined before they are used) | |
47 // in the basic block. A basic block "needs" the locals in its gen set to | |
48 // perform its computation. A basic block "provides" values for the locals in | |
49 // its kill set, allowing a need from a successor to be ignored. | |
50 // | |
51 // 3. Liveness information (the set of locals which are needed) is pushed backwards through | |
52 // the program, from blocks to their predecessors. We compute and store liveness | |
53 // information for the normal/exceptional exit paths for each basic block. When | |
54 // this process reaches a fixed point, we are done. | |
55 // | |
56 // 4. When we are asked about the liveness at a particular bci with a basic block, we | |
57 // compute gen/kill sets which represent execution from that bci to the exit of | |
58 // its blocks. We then compose this range gen/kill information with the normal | |
59 // and exceptional exit information for the block to produce liveness information | |
60 // at that bci. | |
61 // | |
62 // The algorithm is approximate in many respects. Notably: | |
63 // | |
64 // 1. We do not do the analysis necessary to match jsr's with the appropriate ret. | |
65 // Instead we make the conservative assumption that any ret can return to any | |
66 // jsr return site. | |
67 // 2. Instead of computing the effects of exceptions at every instruction, we | |
68 // summarize the effects of all exceptional continuations from the block as | |
69 // a single set (_exception_exit), losing some information but simplifying the | |
70 // analysis. | |
71 | |
72 | |
73 //-------------------------------------------------------------------------- | |
74 // The BitCounter class is used for counting the number of bits set in | |
75 // some BitMap. It is only used when collecting liveness statistics. | |
76 | |
77 #ifndef PRODUCT | |
78 | |
79 class BitCounter: public BitMapClosure { | |
80 private: | |
81 int _count; | |
82 public: | |
83 BitCounter() : _count(0) {} | |
84 | |
85 // Callback when bit in map is set | |
342 | 86 virtual bool do_bit(size_t offset) { |
0 | 87 _count++; |
342 | 88 return true; |
0 | 89 } |
90 | |
91 int count() { | |
92 return _count; | |
93 } | |
94 }; | |
95 | |
96 | |
97 //-------------------------------------------------------------------------- | |
98 | |
99 | |
100 // Counts | |
101 long MethodLiveness::_total_bytes = 0; | |
102 int MethodLiveness::_total_methods = 0; | |
103 | |
104 long MethodLiveness::_total_blocks = 0; | |
105 int MethodLiveness::_max_method_blocks = 0; | |
106 | |
107 long MethodLiveness::_total_edges = 0; | |
108 int MethodLiveness::_max_block_edges = 0; | |
109 | |
110 long MethodLiveness::_total_exc_edges = 0; | |
111 int MethodLiveness::_max_block_exc_edges = 0; | |
112 | |
113 long MethodLiveness::_total_method_locals = 0; | |
114 int MethodLiveness::_max_method_locals = 0; | |
115 | |
116 long MethodLiveness::_total_locals_queried = 0; | |
117 long MethodLiveness::_total_live_locals_queried = 0; | |
118 | |
119 long MethodLiveness::_total_visits = 0; | |
120 | |
121 #endif | |
122 | |
123 // Timers | |
124 elapsedTimer MethodLiveness::_time_build_graph; | |
125 elapsedTimer MethodLiveness::_time_gen_kill; | |
126 elapsedTimer MethodLiveness::_time_flow; | |
127 elapsedTimer MethodLiveness::_time_query; | |
128 elapsedTimer MethodLiveness::_time_total; | |
129 | |
130 MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method) | |
131 #ifdef COMPILER1 | |
132 : _bci_block_start((uintptr_t*)arena->Amalloc((method->code_size() >> LogBitsPerByte) + 1), method->code_size()) | |
133 #endif | |
134 { | |
135 _arena = arena; | |
136 _method = method; | |
137 _bit_map_size_bits = method->max_locals(); | |
138 _bit_map_size_words = (_bit_map_size_bits / sizeof(unsigned int)) + 1; | |
139 | |
140 #ifdef COMPILER1 | |
141 _bci_block_start.clear(); | |
142 #endif | |
143 } | |
144 | |
145 void MethodLiveness::compute_liveness() { | |
146 #ifndef PRODUCT | |
147 if (TraceLivenessGen) { | |
148 tty->print_cr("################################################################"); | |
149 tty->print("# Computing liveness information for "); | |
150 method()->print_short_name(); | |
151 } | |
152 | |
153 if (TimeLivenessAnalysis) _time_total.start(); | |
154 #endif | |
155 | |
156 { | |
157 TraceTime buildGraph(NULL, &_time_build_graph, TimeLivenessAnalysis); | |
158 init_basic_blocks(); | |
159 } | |
160 { | |
161 TraceTime genKill(NULL, &_time_gen_kill, TimeLivenessAnalysis); | |
162 init_gen_kill(); | |
163 } | |
164 { | |
165 TraceTime flow(NULL, &_time_flow, TimeLivenessAnalysis); | |
166 propagate_liveness(); | |
167 } | |
168 | |
169 #ifndef PRODUCT | |
170 if (TimeLivenessAnalysis) _time_total.stop(); | |
171 | |
172 if (TimeLivenessAnalysis) { | |
173 // Collect statistics | |
174 _total_bytes += method()->code_size(); | |
175 _total_methods++; | |
176 | |
177 int num_blocks = _block_count; | |
178 _total_blocks += num_blocks; | |
179 _max_method_blocks = MAX2(num_blocks,_max_method_blocks); | |
180 | |
181 for (int i=0; i<num_blocks; i++) { | |
182 BasicBlock *block = _block_list[i]; | |
183 | |
184 int numEdges = block->_normal_predecessors->length(); | |
185 int numExcEdges = block->_exception_predecessors->length(); | |
186 | |
187 _total_edges += numEdges; | |
188 _total_exc_edges += numExcEdges; | |
189 _max_block_edges = MAX2(numEdges,_max_block_edges); | |
190 _max_block_exc_edges = MAX2(numExcEdges,_max_block_exc_edges); | |
191 } | |
192 | |
193 int numLocals = _bit_map_size_bits; | |
194 _total_method_locals += numLocals; | |
195 _max_method_locals = MAX2(numLocals,_max_method_locals); | |
196 } | |
197 #endif | |
198 } | |
199 | |
200 | |
201 void MethodLiveness::init_basic_blocks() { | |
202 bool bailout = false; | |
203 | |
204 int method_len = method()->code_size(); | |
205 ciMethodBlocks *mblocks = method()->get_method_blocks(); | |
206 | |
207 // Create an array to store the bci->BasicBlock mapping. | |
208 _block_map = new (arena()) GrowableArray<BasicBlock*>(arena(), method_len, method_len, NULL); | |
209 | |
210 _block_count = mblocks->num_blocks(); | |
211 _block_list = (BasicBlock **) arena()->Amalloc(sizeof(BasicBlock *) * _block_count); | |
212 | |
213 // Used for patching up jsr/ret control flow. | |
214 GrowableArray<BasicBlock*>* jsr_exit_list = new GrowableArray<BasicBlock*>(5); | |
215 GrowableArray<BasicBlock*>* ret_list = new GrowableArray<BasicBlock*>(5); | |
216 | |
217 // generate our block list from ciMethodBlocks | |
218 for (int blk = 0; blk < _block_count; blk++) { | |
219 ciBlock *cib = mblocks->block(blk); | |
220 int start_bci = cib->start_bci(); | |
221 _block_list[blk] = new (arena()) BasicBlock(this, start_bci, cib->limit_bci()); | |
222 _block_map->at_put(start_bci, _block_list[blk]); | |
223 #ifdef COMPILER1 | |
224 // mark all bcis where a new basic block starts | |
225 _bci_block_start.set_bit(start_bci); | |
226 #endif // COMPILER1 | |
227 } | |
228 // fill in the predecessors of blocks | |
229 ciBytecodeStream bytes(method()); | |
230 | |
231 for (int blk = 0; blk < _block_count; blk++) { | |
232 BasicBlock *current_block = _block_list[blk]; | |
233 int bci = mblocks->block(blk)->control_bci(); | |
234 | |
235 if (bci == ciBlock::fall_through_bci) { | |
236 int limit = current_block->limit_bci(); | |
237 if (limit < method_len) { | |
238 BasicBlock *next = _block_map->at(limit); | |
239 assert( next != NULL, "must be a block immediately following this one."); | |
240 next->add_normal_predecessor(current_block); | |
241 } | |
242 continue; | |
243 } | |
244 bytes.reset_to_bci(bci); | |
245 Bytecodes::Code code = bytes.next(); | |
246 BasicBlock *dest; | |
247 | |
248 // Now we need to interpret the instruction's effect | |
249 // on control flow. | |
250 assert (current_block != NULL, "we must have a current block"); | |
251 switch (code) { | |
252 case Bytecodes::_ifeq: | |
253 case Bytecodes::_ifne: | |
254 case Bytecodes::_iflt: | |
255 case Bytecodes::_ifge: | |
256 case Bytecodes::_ifgt: | |
257 case Bytecodes::_ifle: | |
258 case Bytecodes::_if_icmpeq: | |
259 case Bytecodes::_if_icmpne: | |
260 case Bytecodes::_if_icmplt: | |
261 case Bytecodes::_if_icmpge: | |
262 case Bytecodes::_if_icmpgt: | |
263 case Bytecodes::_if_icmple: | |
264 case Bytecodes::_if_acmpeq: | |
265 case Bytecodes::_if_acmpne: | |
266 case Bytecodes::_ifnull: | |
267 case Bytecodes::_ifnonnull: | |
268 // Two way branch. Set predecessors at each destination. | |
269 dest = _block_map->at(bytes.next_bci()); | |
270 assert(dest != NULL, "must be a block immediately following this one."); | |
271 dest->add_normal_predecessor(current_block); | |
272 | |
273 dest = _block_map->at(bytes.get_dest()); | |
274 assert(dest != NULL, "branch desination must start a block."); | |
275 dest->add_normal_predecessor(current_block); | |
276 break; | |
277 case Bytecodes::_goto: | |
278 dest = _block_map->at(bytes.get_dest()); | |
279 assert(dest != NULL, "branch desination must start a block."); | |
280 dest->add_normal_predecessor(current_block); | |
281 break; | |
282 case Bytecodes::_goto_w: | |
283 dest = _block_map->at(bytes.get_far_dest()); | |
284 assert(dest != NULL, "branch desination must start a block."); | |
285 dest->add_normal_predecessor(current_block); | |
286 break; | |
287 case Bytecodes::_tableswitch: | |
288 { | |
2142 | 289 Bytecode_tableswitch tableswitch(&bytes); |
0 | 290 |
2142 | 291 int len = tableswitch.length(); |
0 | 292 |
2142 | 293 dest = _block_map->at(bci + tableswitch.default_offset()); |
0 | 294 assert(dest != NULL, "branch desination must start a block."); |
295 dest->add_normal_predecessor(current_block); | |
296 while (--len >= 0) { | |
2142 | 297 dest = _block_map->at(bci + tableswitch.dest_offset_at(len)); |
0 | 298 assert(dest != NULL, "branch desination must start a block."); |
299 dest->add_normal_predecessor(current_block); | |
300 } | |
301 break; | |
302 } | |
303 | |
304 case Bytecodes::_lookupswitch: | |
305 { | |
2142 | 306 Bytecode_lookupswitch lookupswitch(&bytes); |
0 | 307 |
2142 | 308 int npairs = lookupswitch.number_of_pairs(); |
0 | 309 |
2142 | 310 dest = _block_map->at(bci + lookupswitch.default_offset()); |
0 | 311 assert(dest != NULL, "branch desination must start a block."); |
312 dest->add_normal_predecessor(current_block); | |
313 while(--npairs >= 0) { | |
2142 | 314 LookupswitchPair pair = lookupswitch.pair_at(npairs); |
315 dest = _block_map->at( bci + pair.offset()); | |
0 | 316 assert(dest != NULL, "branch desination must start a block."); |
317 dest->add_normal_predecessor(current_block); | |
318 } | |
319 break; | |
320 } | |
321 | |
322 case Bytecodes::_jsr: | |
323 { | |
324 assert(bytes.is_wide()==false, "sanity check"); | |
325 dest = _block_map->at(bytes.get_dest()); | |
326 assert(dest != NULL, "branch desination must start a block."); | |
327 dest->add_normal_predecessor(current_block); | |
328 BasicBlock *jsrExit = _block_map->at(current_block->limit_bci()); | |
329 assert(jsrExit != NULL, "jsr return bci must start a block."); | |
330 jsr_exit_list->append(jsrExit); | |
331 break; | |
332 } | |
333 case Bytecodes::_jsr_w: | |
334 { | |
335 dest = _block_map->at(bytes.get_far_dest()); | |
336 assert(dest != NULL, "branch desination must start a block."); | |
337 dest->add_normal_predecessor(current_block); | |
338 BasicBlock *jsrExit = _block_map->at(current_block->limit_bci()); | |
339 assert(jsrExit != NULL, "jsr return bci must start a block."); | |
340 jsr_exit_list->append(jsrExit); | |
341 break; | |
342 } | |
343 | |
344 case Bytecodes::_wide: | |
345 assert(false, "wide opcodes should not be seen here"); | |
346 break; | |
347 case Bytecodes::_athrow: | |
348 case Bytecodes::_ireturn: | |
349 case Bytecodes::_lreturn: | |
350 case Bytecodes::_freturn: | |
351 case Bytecodes::_dreturn: | |
352 case Bytecodes::_areturn: | |
353 case Bytecodes::_return: | |
354 // These opcodes are not the normal predecessors of any other opcodes. | |
355 break; | |
356 case Bytecodes::_ret: | |
357 // We will patch up jsr/rets in a subsequent pass. | |
358 ret_list->append(current_block); | |
359 break; | |
360 case Bytecodes::_breakpoint: | |
361 // Bail out of there are breakpoints in here. | |
362 bailout = true; | |
363 break; | |
364 default: | |
365 // Do nothing. | |
366 break; | |
367 } | |
368 } | |
369 // Patch up the jsr/ret's. We conservatively assume that any ret | |
370 // can return to any jsr site. | |
371 int ret_list_len = ret_list->length(); | |
372 int jsr_exit_list_len = jsr_exit_list->length(); | |
373 if (ret_list_len > 0 && jsr_exit_list_len > 0) { | |
374 for (int i = jsr_exit_list_len - 1; i >= 0; i--) { | |
375 BasicBlock *jsrExit = jsr_exit_list->at(i); | |
376 for (int i = ret_list_len - 1; i >= 0; i--) { | |
377 jsrExit->add_normal_predecessor(ret_list->at(i)); | |
378 } | |
379 } | |
380 } | |
381 | |
382 // Compute exception edges. | |
383 for (int b=_block_count-1; b >= 0; b--) { | |
384 BasicBlock *block = _block_list[b]; | |
385 int block_start = block->start_bci(); | |
386 int block_limit = block->limit_bci(); | |
387 ciExceptionHandlerStream handlers(method()); | |
388 for (; !handlers.is_done(); handlers.next()) { | |
389 ciExceptionHandler* handler = handlers.handler(); | |
390 int start = handler->start(); | |
391 int limit = handler->limit(); | |
392 int handler_bci = handler->handler_bci(); | |
393 | |
394 int intersect_start = MAX2(block_start, start); | |
395 int intersect_limit = MIN2(block_limit, limit); | |
396 if (intersect_start < intersect_limit) { | |
397 // The catch range has a nonempty intersection with this | |
398 // basic block. That means this basic block can be an | |
399 // exceptional predecessor. | |
400 _block_map->at(handler_bci)->add_exception_predecessor(block); | |
401 | |
402 if (handler->is_catch_all()) { | |
403 // This is a catch-all block. | |
404 if (intersect_start == block_start && intersect_limit == block_limit) { | |
405 // The basic block is entirely contained in this catch-all block. | |
406 // Skip the rest of the exception handlers -- they can never be | |
407 // reached in execution. | |
408 break; | |
409 } | |
410 } | |
411 } | |
412 } | |
413 } | |
414 } | |
415 | |
416 void MethodLiveness::init_gen_kill() { | |
417 for (int i=_block_count-1; i >= 0; i--) { | |
418 _block_list[i]->compute_gen_kill(method()); | |
419 } | |
420 } | |
421 | |
422 void MethodLiveness::propagate_liveness() { | |
423 int num_blocks = _block_count; | |
424 BasicBlock *block; | |
425 | |
426 // We start our work list off with all blocks in it. | |
427 // Alternately, we could start off the work list with the list of all | |
428 // blocks which could exit the method directly, along with one block | |
429 // from any infinite loop. If this matters, it can be changed. It | |
430 // may not be clear from looking at the code, but the order of the | |
431 // workList will be the opposite of the creation order of the basic | |
432 // blocks, which should be decent for quick convergence (with the | |
433 // possible exception of exception handlers, which are all created | |
434 // early). | |
435 _work_list = NULL; | |
436 for (int i = 0; i < num_blocks; i++) { | |
437 block = _block_list[i]; | |
438 block->set_next(_work_list); | |
439 block->set_on_work_list(true); | |
440 _work_list = block; | |
441 } | |
442 | |
443 | |
444 while ((block = work_list_get()) != NULL) { | |
445 block->propagate(this); | |
446 NOT_PRODUCT(_total_visits++;) | |
447 } | |
448 } | |
449 | |
450 void MethodLiveness::work_list_add(BasicBlock *block) { | |
451 if (!block->on_work_list()) { | |
452 block->set_next(_work_list); | |
453 block->set_on_work_list(true); | |
454 _work_list = block; | |
455 } | |
456 } | |
457 | |
458 MethodLiveness::BasicBlock *MethodLiveness::work_list_get() { | |
459 BasicBlock *block = _work_list; | |
460 if (block != NULL) { | |
461 block->set_on_work_list(false); | |
462 _work_list = block->next(); | |
463 } | |
464 return block; | |
465 } | |
466 | |
467 | |
468 MethodLivenessResult MethodLiveness::get_liveness_at(int entry_bci) { | |
469 int bci = entry_bci; | |
470 bool is_entry = false; | |
471 if (entry_bci == InvocationEntryBci) { | |
472 is_entry = true; | |
473 bci = 0; | |
474 } | |
475 | |
342 | 476 MethodLivenessResult answer((uintptr_t*)NULL,0); |
0 | 477 |
478 if (_block_count > 0) { | |
479 if (TimeLivenessAnalysis) _time_total.start(); | |
480 if (TimeLivenessAnalysis) _time_query.start(); | |
481 | |
482 assert( 0 <= bci && bci < method()->code_size(), "bci out of range" ); | |
483 BasicBlock *block = _block_map->at(bci); | |
484 // We may not be at the block start, so search backwards to find the block | |
485 // containing bci. | |
486 int t = bci; | |
487 while (block == NULL && t > 0) { | |
488 block = _block_map->at(--t); | |
489 } | |
490 assert( block != NULL, "invalid bytecode index; must be instruction index" ); | |
491 assert(bci >= block->start_bci() && bci < block->limit_bci(), "block must contain bci."); | |
492 | |
493 answer = block->get_liveness_at(method(), bci); | |
494 | |
495 if (is_entry && method()->is_synchronized() && !method()->is_static()) { | |
496 // Synchronized methods use the receiver once on entry. | |
497 answer.at_put(0, true); | |
498 } | |
499 | |
500 #ifndef PRODUCT | |
501 if (TraceLivenessQuery) { | |
502 tty->print("Liveness query of "); | |
503 method()->print_short_name(); | |
504 tty->print(" @ %d : result is ", bci); | |
505 answer.print_on(tty); | |
506 } | |
507 | |
508 if (TimeLivenessAnalysis) _time_query.stop(); | |
509 if (TimeLivenessAnalysis) _time_total.stop(); | |
510 #endif | |
511 } | |
512 | |
513 #ifndef PRODUCT | |
514 if (TimeLivenessAnalysis) { | |
515 // Collect statistics. | |
516 _total_locals_queried += _bit_map_size_bits; | |
517 BitCounter counter; | |
518 answer.iterate(&counter); | |
519 _total_live_locals_queried += counter.count(); | |
520 } | |
521 #endif | |
522 | |
523 return answer; | |
524 } | |
525 | |
526 | |
527 #ifndef PRODUCT | |
528 | |
529 void MethodLiveness::print_times() { | |
530 tty->print_cr ("Accumulated liveness analysis times/statistics:"); | |
531 tty->print_cr ("-----------------------------------------------"); | |
532 tty->print_cr (" Total : %3.3f sec.", _time_total.seconds()); | |
533 tty->print_cr (" Build graph : %3.3f sec. (%2.2f%%)", _time_build_graph.seconds(), | |
534 _time_build_graph.seconds() * 100 / _time_total.seconds()); | |
535 tty->print_cr (" Gen / Kill : %3.3f sec. (%2.2f%%)", _time_gen_kill.seconds(), | |
536 _time_gen_kill.seconds() * 100 / _time_total.seconds()); | |
537 tty->print_cr (" Dataflow : %3.3f sec. (%2.2f%%)", _time_flow.seconds(), | |
538 _time_flow.seconds() * 100 / _time_total.seconds()); | |
539 tty->print_cr (" Query : %3.3f sec. (%2.2f%%)", _time_query.seconds(), | |
540 _time_query.seconds() * 100 / _time_total.seconds()); | |
541 tty->print_cr (" #bytes : %8d (%3.0f bytes per sec)", | |
542 _total_bytes, | |
543 _total_bytes / _time_total.seconds()); | |
544 tty->print_cr (" #methods : %8d (%3.0f methods per sec)", | |
545 _total_methods, | |
546 _total_methods / _time_total.seconds()); | |
547 tty->print_cr (" avg locals : %3.3f max locals : %3d", | |
548 (float)_total_method_locals / _total_methods, | |
549 _max_method_locals); | |
550 tty->print_cr (" avg blocks : %3.3f max blocks : %3d", | |
551 (float)_total_blocks / _total_methods, | |
552 _max_method_blocks); | |
553 tty->print_cr (" avg bytes : %3.3f", | |
554 (float)_total_bytes / _total_methods); | |
555 tty->print_cr (" #blocks : %8d", | |
556 _total_blocks); | |
557 tty->print_cr (" avg normal predecessors : %3.3f max normal predecessors : %3d", | |
558 (float)_total_edges / _total_blocks, | |
559 _max_block_edges); | |
560 tty->print_cr (" avg exception predecessors : %3.3f max exception predecessors : %3d", | |
561 (float)_total_exc_edges / _total_blocks, | |
562 _max_block_exc_edges); | |
563 tty->print_cr (" avg visits : %3.3f", | |
564 (float)_total_visits / _total_blocks); | |
565 tty->print_cr (" #locals queried : %8d #live : %8d %%live : %2.2f%%", | |
566 _total_locals_queried, | |
567 _total_live_locals_queried, | |
568 100.0 * _total_live_locals_queried / _total_locals_queried); | |
569 } | |
570 | |
571 #endif | |
572 | |
573 | |
574 MethodLiveness::BasicBlock::BasicBlock(MethodLiveness *analyzer, int start, int limit) : | |
575 _gen((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), | |
576 analyzer->bit_map_size_bits()), | |
577 _kill((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), | |
578 analyzer->bit_map_size_bits()), | |
579 _entry((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), | |
580 analyzer->bit_map_size_bits()), | |
581 _normal_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), | |
582 analyzer->bit_map_size_bits()), | |
583 _exception_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), | |
584 analyzer->bit_map_size_bits()), | |
585 _last_bci(-1) { | |
586 _analyzer = analyzer; | |
587 _start_bci = start; | |
588 _limit_bci = limit; | |
589 _normal_predecessors = | |
590 new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL); | |
591 _exception_predecessors = | |
592 new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL); | |
593 _normal_exit.clear(); | |
594 _exception_exit.clear(); | |
595 _entry.clear(); | |
596 | |
597 // this initialization is not strictly necessary. | |
598 // _gen and _kill are cleared at the beginning of compute_gen_kill_range() | |
599 _gen.clear(); | |
600 _kill.clear(); | |
601 } | |
602 | |
603 | |
604 | |
605 MethodLiveness::BasicBlock *MethodLiveness::BasicBlock::split(int split_bci) { | |
606 int start = _start_bci; | |
607 int limit = _limit_bci; | |
608 | |
609 if (TraceLivenessGen) { | |
610 tty->print_cr(" ** Splitting block (%d,%d) at %d", start, limit, split_bci); | |
611 } | |
612 | |
613 GrowableArray<BasicBlock*>* save_predecessors = _normal_predecessors; | |
614 | |
615 assert (start < split_bci && split_bci < limit, "improper split"); | |
616 | |
617 // Make a new block to cover the first half of the range. | |
618 BasicBlock *first_half = new (_analyzer->arena()) BasicBlock(_analyzer, start, split_bci); | |
619 | |
620 // Assign correct values to the second half (this) | |
621 _normal_predecessors = first_half->_normal_predecessors; | |
622 _start_bci = split_bci; | |
623 add_normal_predecessor(first_half); | |
624 | |
625 // Assign correct predecessors to the new first half | |
626 first_half->_normal_predecessors = save_predecessors; | |
627 | |
628 return first_half; | |
629 } | |
630 | |
631 void MethodLiveness::BasicBlock::compute_gen_kill(ciMethod* method) { | |
632 ciBytecodeStream bytes(method); | |
633 bytes.reset_to_bci(start_bci()); | |
634 bytes.set_max_bci(limit_bci()); | |
635 compute_gen_kill_range(&bytes); | |
636 | |
637 } | |
638 | |
639 void MethodLiveness::BasicBlock::compute_gen_kill_range(ciBytecodeStream *bytes) { | |
640 _gen.clear(); | |
641 _kill.clear(); | |
642 | |
643 while (bytes->next() != ciBytecodeStream::EOBC()) { | |
644 compute_gen_kill_single(bytes); | |
645 } | |
646 } | |
647 | |
648 void MethodLiveness::BasicBlock::compute_gen_kill_single(ciBytecodeStream *instruction) { | |
649 int localNum; | |
650 | |
651 // We prohibit _gen and _kill from having locals in common. If we | |
652 // know that one is definitely going to be applied before the other, | |
653 // we could save some computation time by relaxing this prohibition. | |
654 | |
655 switch (instruction->cur_bc()) { | |
656 case Bytecodes::_nop: | |
657 case Bytecodes::_goto: | |
658 case Bytecodes::_goto_w: | |
659 case Bytecodes::_aconst_null: | |
660 case Bytecodes::_new: | |
661 case Bytecodes::_iconst_m1: | |
662 case Bytecodes::_iconst_0: | |
663 case Bytecodes::_iconst_1: | |
664 case Bytecodes::_iconst_2: | |
665 case Bytecodes::_iconst_3: | |
666 case Bytecodes::_iconst_4: | |
667 case Bytecodes::_iconst_5: | |
668 case Bytecodes::_fconst_0: | |
669 case Bytecodes::_fconst_1: | |
670 case Bytecodes::_fconst_2: | |
671 case Bytecodes::_bipush: | |
672 case Bytecodes::_sipush: | |
673 case Bytecodes::_lconst_0: | |
674 case Bytecodes::_lconst_1: | |
675 case Bytecodes::_dconst_0: | |
676 case Bytecodes::_dconst_1: | |
677 case Bytecodes::_ldc2_w: | |
678 case Bytecodes::_ldc: | |
679 case Bytecodes::_ldc_w: | |
680 case Bytecodes::_iaload: | |
681 case Bytecodes::_faload: | |
682 case Bytecodes::_baload: | |
683 case Bytecodes::_caload: | |
684 case Bytecodes::_saload: | |
685 case Bytecodes::_laload: | |
686 case Bytecodes::_daload: | |
687 case Bytecodes::_aaload: | |
688 case Bytecodes::_iastore: | |
689 case Bytecodes::_fastore: | |
690 case Bytecodes::_bastore: | |
691 case Bytecodes::_castore: | |
692 case Bytecodes::_sastore: | |
693 case Bytecodes::_lastore: | |
694 case Bytecodes::_dastore: | |
695 case Bytecodes::_aastore: | |
696 case Bytecodes::_pop: | |
697 case Bytecodes::_pop2: | |
698 case Bytecodes::_dup: | |
699 case Bytecodes::_dup_x1: | |
700 case Bytecodes::_dup_x2: | |
701 case Bytecodes::_dup2: | |
702 case Bytecodes::_dup2_x1: | |
703 case Bytecodes::_dup2_x2: | |
704 case Bytecodes::_swap: | |
705 case Bytecodes::_iadd: | |
706 case Bytecodes::_fadd: | |
707 case Bytecodes::_isub: | |
708 case Bytecodes::_fsub: | |
709 case Bytecodes::_imul: | |
710 case Bytecodes::_fmul: | |
711 case Bytecodes::_idiv: | |
712 case Bytecodes::_fdiv: | |
713 case Bytecodes::_irem: | |
714 case Bytecodes::_frem: | |
715 case Bytecodes::_ishl: | |
716 case Bytecodes::_ishr: | |
717 case Bytecodes::_iushr: | |
718 case Bytecodes::_iand: | |
719 case Bytecodes::_ior: | |
720 case Bytecodes::_ixor: | |
721 case Bytecodes::_l2f: | |
722 case Bytecodes::_l2i: | |
723 case Bytecodes::_d2f: | |
724 case Bytecodes::_d2i: | |
725 case Bytecodes::_fcmpl: | |
726 case Bytecodes::_fcmpg: | |
727 case Bytecodes::_ladd: | |
728 case Bytecodes::_dadd: | |
729 case Bytecodes::_lsub: | |
730 case Bytecodes::_dsub: | |
731 case Bytecodes::_lmul: | |
732 case Bytecodes::_dmul: | |
733 case Bytecodes::_ldiv: | |
734 case Bytecodes::_ddiv: | |
735 case Bytecodes::_lrem: | |
736 case Bytecodes::_drem: | |
737 case Bytecodes::_land: | |
738 case Bytecodes::_lor: | |
739 case Bytecodes::_lxor: | |
740 case Bytecodes::_ineg: | |
741 case Bytecodes::_fneg: | |
742 case Bytecodes::_i2f: | |
743 case Bytecodes::_f2i: | |
744 case Bytecodes::_i2c: | |
745 case Bytecodes::_i2s: | |
746 case Bytecodes::_i2b: | |
747 case Bytecodes::_lneg: | |
748 case Bytecodes::_dneg: | |
749 case Bytecodes::_l2d: | |
750 case Bytecodes::_d2l: | |
751 case Bytecodes::_lshl: | |
752 case Bytecodes::_lshr: | |
753 case Bytecodes::_lushr: | |
754 case Bytecodes::_i2l: | |
755 case Bytecodes::_i2d: | |
756 case Bytecodes::_f2l: | |
757 case Bytecodes::_f2d: | |
758 case Bytecodes::_lcmp: | |
759 case Bytecodes::_dcmpl: | |
760 case Bytecodes::_dcmpg: | |
761 case Bytecodes::_ifeq: | |
762 case Bytecodes::_ifne: | |
763 case Bytecodes::_iflt: | |
764 case Bytecodes::_ifge: | |
765 case Bytecodes::_ifgt: | |
766 case Bytecodes::_ifle: | |
767 case Bytecodes::_tableswitch: | |
768 case Bytecodes::_ireturn: | |
769 case Bytecodes::_freturn: | |
770 case Bytecodes::_if_icmpeq: | |
771 case Bytecodes::_if_icmpne: | |
772 case Bytecodes::_if_icmplt: | |
773 case Bytecodes::_if_icmpge: | |
774 case Bytecodes::_if_icmpgt: | |
775 case Bytecodes::_if_icmple: | |
776 case Bytecodes::_lreturn: | |
777 case Bytecodes::_dreturn: | |
778 case Bytecodes::_if_acmpeq: | |
779 case Bytecodes::_if_acmpne: | |
780 case Bytecodes::_jsr: | |
781 case Bytecodes::_jsr_w: | |
782 case Bytecodes::_getstatic: | |
783 case Bytecodes::_putstatic: | |
784 case Bytecodes::_getfield: | |
785 case Bytecodes::_putfield: | |
786 case Bytecodes::_invokevirtual: | |
787 case Bytecodes::_invokespecial: | |
788 case Bytecodes::_invokestatic: | |
789 case Bytecodes::_invokeinterface: | |
1135
e66fd840cb6b
6893081: method handle & invokedynamic code needs additional cleanup (post 6815692, 6858164)
twisti
parents:
342
diff
changeset
|
790 case Bytecodes::_invokedynamic: |
0 | 791 case Bytecodes::_newarray: |
792 case Bytecodes::_anewarray: | |
793 case Bytecodes::_checkcast: | |
794 case Bytecodes::_arraylength: | |
795 case Bytecodes::_instanceof: | |
796 case Bytecodes::_athrow: | |
797 case Bytecodes::_areturn: | |
798 case Bytecodes::_monitorenter: | |
799 case Bytecodes::_monitorexit: | |
800 case Bytecodes::_ifnull: | |
801 case Bytecodes::_ifnonnull: | |
802 case Bytecodes::_multianewarray: | |
803 case Bytecodes::_lookupswitch: | |
804 // These bytecodes have no effect on the method's locals. | |
805 break; | |
806 | |
807 case Bytecodes::_return: | |
808 if (instruction->method()->intrinsic_id() == vmIntrinsics::_Object_init) { | |
809 // return from Object.init implicitly registers a finalizer | |
810 // for the receiver if needed, so keep it alive. | |
811 load_one(0); | |
812 } | |
813 break; | |
814 | |
815 | |
816 case Bytecodes::_lload: | |
817 case Bytecodes::_dload: | |
818 load_two(instruction->get_index()); | |
819 break; | |
820 | |
821 case Bytecodes::_lload_0: | |
822 case Bytecodes::_dload_0: | |
823 load_two(0); | |
824 break; | |
825 | |
826 case Bytecodes::_lload_1: | |
827 case Bytecodes::_dload_1: | |
828 load_two(1); | |
829 break; | |
830 | |
831 case Bytecodes::_lload_2: | |
832 case Bytecodes::_dload_2: | |
833 load_two(2); | |
834 break; | |
835 | |
836 case Bytecodes::_lload_3: | |
837 case Bytecodes::_dload_3: | |
838 load_two(3); | |
839 break; | |
840 | |
841 case Bytecodes::_iload: | |
842 case Bytecodes::_iinc: | |
843 case Bytecodes::_fload: | |
844 case Bytecodes::_aload: | |
845 case Bytecodes::_ret: | |
846 load_one(instruction->get_index()); | |
847 break; | |
848 | |
849 case Bytecodes::_iload_0: | |
850 case Bytecodes::_fload_0: | |
851 case Bytecodes::_aload_0: | |
852 load_one(0); | |
853 break; | |
854 | |
855 case Bytecodes::_iload_1: | |
856 case Bytecodes::_fload_1: | |
857 case Bytecodes::_aload_1: | |
858 load_one(1); | |
859 break; | |
860 | |
861 case Bytecodes::_iload_2: | |
862 case Bytecodes::_fload_2: | |
863 case Bytecodes::_aload_2: | |
864 load_one(2); | |
865 break; | |
866 | |
867 case Bytecodes::_iload_3: | |
868 case Bytecodes::_fload_3: | |
869 case Bytecodes::_aload_3: | |
870 load_one(3); | |
871 break; | |
872 | |
873 case Bytecodes::_lstore: | |
874 case Bytecodes::_dstore: | |
875 store_two(localNum = instruction->get_index()); | |
876 break; | |
877 | |
878 case Bytecodes::_lstore_0: | |
879 case Bytecodes::_dstore_0: | |
880 store_two(0); | |
881 break; | |
882 | |
883 case Bytecodes::_lstore_1: | |
884 case Bytecodes::_dstore_1: | |
885 store_two(1); | |
886 break; | |
887 | |
888 case Bytecodes::_lstore_2: | |
889 case Bytecodes::_dstore_2: | |
890 store_two(2); | |
891 break; | |
892 | |
893 case Bytecodes::_lstore_3: | |
894 case Bytecodes::_dstore_3: | |
895 store_two(3); | |
896 break; | |
897 | |
898 case Bytecodes::_istore: | |
899 case Bytecodes::_fstore: | |
900 case Bytecodes::_astore: | |
901 store_one(instruction->get_index()); | |
902 break; | |
903 | |
904 case Bytecodes::_istore_0: | |
905 case Bytecodes::_fstore_0: | |
906 case Bytecodes::_astore_0: | |
907 store_one(0); | |
908 break; | |
909 | |
910 case Bytecodes::_istore_1: | |
911 case Bytecodes::_fstore_1: | |
912 case Bytecodes::_astore_1: | |
913 store_one(1); | |
914 break; | |
915 | |
916 case Bytecodes::_istore_2: | |
917 case Bytecodes::_fstore_2: | |
918 case Bytecodes::_astore_2: | |
919 store_one(2); | |
920 break; | |
921 | |
922 case Bytecodes::_istore_3: | |
923 case Bytecodes::_fstore_3: | |
924 case Bytecodes::_astore_3: | |
925 store_one(3); | |
926 break; | |
927 | |
928 case Bytecodes::_wide: | |
929 fatal("Iterator should skip this bytecode"); | |
930 break; | |
931 | |
932 default: | |
933 tty->print("unexpected opcode: %d\n", instruction->cur_bc()); | |
934 ShouldNotReachHere(); | |
935 break; | |
936 } | |
937 } | |
938 | |
939 void MethodLiveness::BasicBlock::load_two(int local) { | |
940 load_one(local); | |
941 load_one(local+1); | |
942 } | |
943 | |
944 void MethodLiveness::BasicBlock::load_one(int local) { | |
945 if (!_kill.at(local)) { | |
946 _gen.at_put(local, true); | |
947 } | |
948 } | |
949 | |
950 void MethodLiveness::BasicBlock::store_two(int local) { | |
951 store_one(local); | |
952 store_one(local+1); | |
953 } | |
954 | |
955 void MethodLiveness::BasicBlock::store_one(int local) { | |
956 if (!_gen.at(local)) { | |
957 _kill.at_put(local, true); | |
958 } | |
959 } | |
960 | |
961 void MethodLiveness::BasicBlock::propagate(MethodLiveness *ml) { | |
962 // These set operations could be combined for efficiency if the | |
963 // performance of this analysis becomes an issue. | |
964 _entry.set_union(_normal_exit); | |
965 _entry.set_difference(_kill); | |
966 _entry.set_union(_gen); | |
967 | |
968 // Note that we merge information from our exceptional successors | |
969 // just once, rather than at individual bytecodes. | |
970 _entry.set_union(_exception_exit); | |
971 | |
972 if (TraceLivenessGen) { | |
973 tty->print_cr(" ** Visiting block at %d **", start_bci()); | |
974 print_on(tty); | |
975 } | |
976 | |
977 int i; | |
978 for (i=_normal_predecessors->length()-1; i>=0; i--) { | |
979 BasicBlock *block = _normal_predecessors->at(i); | |
980 if (block->merge_normal(_entry)) { | |
981 ml->work_list_add(block); | |
982 } | |
983 } | |
984 for (i=_exception_predecessors->length()-1; i>=0; i--) { | |
985 BasicBlock *block = _exception_predecessors->at(i); | |
986 if (block->merge_exception(_entry)) { | |
987 ml->work_list_add(block); | |
988 } | |
989 } | |
990 } | |
991 | |
992 bool MethodLiveness::BasicBlock::merge_normal(BitMap other) { | |
993 return _normal_exit.set_union_with_result(other); | |
994 } | |
995 | |
996 bool MethodLiveness::BasicBlock::merge_exception(BitMap other) { | |
997 return _exception_exit.set_union_with_result(other); | |
998 } | |
999 | |
1000 MethodLivenessResult MethodLiveness::BasicBlock::get_liveness_at(ciMethod* method, int bci) { | |
1001 MethodLivenessResult answer(NEW_RESOURCE_ARRAY(uintptr_t, _analyzer->bit_map_size_words()), | |
1002 _analyzer->bit_map_size_bits()); | |
1003 answer.set_is_valid(); | |
1004 | |
1005 #ifndef ASSERT | |
1006 if (bci == start_bci()) { | |
1007 answer.set_from(_entry); | |
1008 return answer; | |
1009 } | |
1010 #endif | |
1011 | |
1012 #ifdef ASSERT | |
1013 ResourceMark rm; | |
1014 BitMap g(_gen.size()); g.set_from(_gen); | |
1015 BitMap k(_kill.size()); k.set_from(_kill); | |
1016 #endif | |
1017 if (_last_bci != bci || trueInDebug) { | |
1018 ciBytecodeStream bytes(method); | |
1019 bytes.reset_to_bci(bci); | |
1020 bytes.set_max_bci(limit_bci()); | |
1021 compute_gen_kill_range(&bytes); | |
1022 assert(_last_bci != bci || | |
1023 (g.is_same(_gen) && k.is_same(_kill)), "cached computation is incorrect"); | |
1024 _last_bci = bci; | |
1025 } | |
1026 | |
1027 answer.clear(); | |
1028 answer.set_union(_normal_exit); | |
1029 answer.set_difference(_kill); | |
1030 answer.set_union(_gen); | |
1031 answer.set_union(_exception_exit); | |
1032 | |
1033 #ifdef ASSERT | |
1034 if (bci == start_bci()) { | |
1035 assert(answer.is_same(_entry), "optimized answer must be accurate"); | |
1036 } | |
1037 #endif | |
1038 | |
1039 return answer; | |
1040 } | |
1041 | |
1042 #ifndef PRODUCT | |
1043 | |
1044 void MethodLiveness::BasicBlock::print_on(outputStream *os) const { | |
1045 os->print_cr("==================================================================="); | |
1046 os->print_cr(" Block start: %4d, limit: %4d", _start_bci, _limit_bci); | |
1047 os->print (" Normal predecessors (%2d) @", _normal_predecessors->length()); | |
1048 int i; | |
1049 for (i=0; i < _normal_predecessors->length(); i++) { | |
1050 os->print(" %4d", _normal_predecessors->at(i)->start_bci()); | |
1051 } | |
1052 os->cr(); | |
1053 os->print (" Exceptional predecessors (%2d) @", _exception_predecessors->length()); | |
1054 for (i=0; i < _exception_predecessors->length(); i++) { | |
1055 os->print(" %4d", _exception_predecessors->at(i)->start_bci()); | |
1056 } | |
1057 os->cr(); | |
1058 os->print (" Normal Exit : "); | |
1059 _normal_exit.print_on(os); | |
1060 os->print (" Gen : "); | |
1061 _gen.print_on(os); | |
1062 os->print (" Kill : "); | |
1063 _kill.print_on(os); | |
1064 os->print (" Exception Exit: "); | |
1065 _exception_exit.print_on(os); | |
1066 os->print (" Entry : "); | |
1067 _entry.print_on(os); | |
1068 } | |
1069 | |
1070 #endif // PRODUCT |