1 /*
2 * Copyright (c) 2005, 2017, 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 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "ci/ciConstant.hpp"
28 #include "ci/ciField.hpp"
29 #include "ci/ciMethodBlocks.hpp"
30 #include "ci/ciStreams.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/bitMap.inline.hpp"
35
36
37
38 #ifndef PRODUCT
39 #define TRACE_BCEA(level, code) \
40 if (EstimateArgEscape && BCEATraceLevel >= level) { \
41 code; \
42 }
43 #else
44 #define TRACE_BCEA(level, code)
45 #endif
46
47 // Maintain a map of which arguments a local variable or
48 // stack slot may contain. In addition to tracking
49 // arguments, it tracks two special values, "allocated"
50 // which represents any object allocated in the current
51 // method, and "unknown" which is any other object.
52 // Up to 30 arguments are handled, with the last one
53 // representing summary information for any extra arguments
54 class BCEscapeAnalyzer::ArgumentMap {
55 uint _bits;
56 enum {MAXBIT = 29,
57 ALLOCATED = 1,
58 UNKNOWN = 2};
59
60 uint int_to_bit(uint e) const {
61 if (e > MAXBIT)
62 e = MAXBIT;
63 return (1 << (e + 2));
64 }
65
66 public:
67 ArgumentMap() { _bits = 0;}
68 void set_bits(uint bits) { _bits = bits;}
69 uint get_bits() const { return _bits;}
70 void clear() { _bits = 0;}
71 void set_all() { _bits = ~0u; }
72 bool is_empty() const { return _bits == 0; }
73 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
74 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
75 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
76 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
77 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
78 void set(uint var) { _bits = int_to_bit(var); }
79 void add(uint var) { _bits |= int_to_bit(var); }
80 void add_unknown() { _bits = UNKNOWN; }
81 void add_allocated() { _bits = ALLOCATED; }
82 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
83 void set_intersect(const ArgumentMap &am) { _bits |= am._bits; }
84 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
85 void operator=(const ArgumentMap &am) { _bits = am._bits; }
86 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
87 bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
88 };
89
90 class BCEscapeAnalyzer::StateInfo {
91 public:
92 ArgumentMap *_vars;
93 ArgumentMap *_stack;
94 int _stack_height;
95 int _max_stack;
96 bool _initialized;
97 ArgumentMap empty_map;
98
99 StateInfo() {
100 empty_map.clear();
101 }
102
103 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
104 ArgumentMap apop() { return raw_pop(); }
105 void spop() { raw_pop(); }
106 void lpop() { spop(); spop(); }
107 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
108 void apush(ArgumentMap i) { raw_push(i); }
109 void spush() { raw_push(empty_map); }
110 void lpush() { spush(); spush(); }
111
112 };
113
114 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
115 for (int i = 0; i < _arg_size; i++) {
116 if (vars.contains(i))
117 _arg_returned.set(i);
118 }
119 _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
120 _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
121 }
122
123 // return true if any element of vars is an argument
124 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
125 for (int i = 0; i < _arg_size; i++) {
126 if (vars.contains(i))
127 return true;
128 }
129 return false;
130 }
131
132 // return true if any element of vars is an arg_stack argument
133 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
134 if (_conservative)
135 return true;
136 for (int i = 0; i < _arg_size; i++) {
137 if (vars.contains(i) && _arg_stack.test(i))
138 return true;
139 }
140 return false;
141 }
142
143 // return true if all argument elements of vars are returned
144 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
145 for (int i = 0; i < _arg_size; i++) {
146 if (vars.contains(i) && !_arg_returned.test(i)) {
147 return false;
148 }
149 }
150 return true;
151 }
152
153 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
154 for (int i = 0; i < _arg_size; i++) {
155 if (vars.contains(i)) {
156 bm >>= i;
157 }
158 }
159 }
160
161 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
162 clear_bits(vars, _arg_local);
163 if (vars.contains_allocated()) {
164 _allocated_escapes = true;
165 }
166 }
167
168 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
169 clear_bits(vars, _arg_local);
170 clear_bits(vars, _arg_stack);
171 if (vars.contains_allocated())
172 _allocated_escapes = true;
173
174 if (merge && !vars.is_empty()) {
175 // Merge new state into already processed block.
176 // New state is not taken into account and
177 // it may invalidate set_returned() result.
178 if (vars.contains_unknown() || vars.contains_allocated()) {
179 _return_local = false;
180 }
181 if (vars.contains_unknown() || vars.contains_vars()) {
182 _return_allocated = false;
183 }
184 if (_return_local && vars.contains_vars() && !returns_all(vars)) {
185 // Return result should be invalidated if args in new
186 // state are not recorded in return state.
187 _return_local = false;
188 }
189 }
190 }
191
192 void BCEscapeAnalyzer::set_dirty(ArgumentMap vars) {
193 clear_bits(vars, _dirty);
194 }
195
196 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
197
198 for (int i = 0; i < _arg_size; i++) {
199 if (vars.contains(i)) {
200 set_arg_modified(i, offs, size);
201 }
202 }
203 if (vars.contains_unknown())
204 _unknown_modified = true;
205 }
206
207 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
208 for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
209 if (scope->method() == callee) {
210 return true;
211 }
212 }
213 return false;
214 }
215
216 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
217 if (offset == OFFSET_ANY)
218 return _arg_modified[arg] != 0;
219 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
220 bool modified = false;
221 int l = offset / HeapWordSize;
222 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
223 if (l > ARG_OFFSET_MAX)
224 l = ARG_OFFSET_MAX;
225 if (h > ARG_OFFSET_MAX+1)
226 h = ARG_OFFSET_MAX + 1;
227 for (int i = l; i < h; i++) {
228 modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
229 }
230 return modified;
231 }
232
233 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
234 if (offset == OFFSET_ANY) {
235 _arg_modified[arg] = (uint) -1;
236 return;
237 }
238 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
239 int l = offset / HeapWordSize;
240 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
241 if (l > ARG_OFFSET_MAX)
242 l = ARG_OFFSET_MAX;
243 if (h > ARG_OFFSET_MAX+1)
244 h = ARG_OFFSET_MAX + 1;
245 for (int i = l; i < h; i++) {
246 _arg_modified[arg] |= (1 << i);
247 }
248 }
249
250 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
251 int i;
252
253 // retrieve information about the callee
254 ciInstanceKlass* klass = target->holder();
255 ciInstanceKlass* calling_klass = method()->holder();
256 ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
257 ciInstanceKlass* actual_recv = callee_holder;
258
259 // Some methods are obviously bindable without any type checks so
260 // convert them directly to an invokespecial or invokestatic.
261 if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
262 switch (code) {
263 case Bytecodes::_invokevirtual:
264 code = Bytecodes::_invokespecial;
265 break;
266 case Bytecodes::_invokehandle:
267 code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
268 break;
269 default:
270 break;
271 }
272 }
273
274 // compute size of arguments
275 int arg_size = target->invoke_arg_size(code);
276 int arg_base = MAX2(state._stack_height - arg_size, 0);
277
278 // direct recursive calls are skipped if they can be bound statically without introducing
279 // dependencies and if parameters are passed at the same position as in the current method
280 // other calls are skipped if there are no unescaped arguments passed to them
281 bool directly_recursive = (method() == target) &&
282 (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
283
284 // check if analysis of callee can safely be skipped
285 bool skip_callee = true;
286 for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
287 ArgumentMap arg = state._stack[i];
288 skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
289 }
290 // For now we conservatively skip invokedynamic.
291 if (code == Bytecodes::_invokedynamic) {
292 skip_callee = true;
293 }
294 if (skip_callee) {
295 TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
296 for (i = 0; i < arg_size; i++) {
297 set_method_escape(state.raw_pop());
298 }
299 _unknown_modified = true; // assume the worst since we don't analyze the called method
300 return;
301 }
302
303 // determine actual method (use CHA if necessary)
304 ciMethod* inline_target = NULL;
305 if (target->is_loaded() && klass->is_loaded()
306 && (klass->is_initialized() || (klass->is_interface() && target->holder()->is_initialized()))
307 && target->is_loaded()) {
308 if (code == Bytecodes::_invokestatic
309 || code == Bytecodes::_invokespecial
310 || (code == Bytecodes::_invokevirtual && target->is_final_method())) {
311 inline_target = target;
312 } else {
313 inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
314 }
315 }
316
317 if (inline_target != NULL && !is_recursive_call(inline_target)) {
318 // analyze callee
319 BCEscapeAnalyzer analyzer(inline_target, this);
320
321 // adjust escape state of actual parameters
322 bool must_record_dependencies = false;
323 for (i = arg_size - 1; i >= 0; i--) {
324 ArgumentMap arg = state.raw_pop();
325 // Check if callee arg is a caller arg or an allocated object
326 bool allocated = arg.contains_allocated();
327 if (!(is_argument(arg) || allocated))
328 continue;
329 for (int j = 0; j < _arg_size; j++) {
330 if (arg.contains(j)) {
331 _arg_modified[j] |= analyzer._arg_modified[i];
332 }
333 }
334 if (!(is_arg_stack(arg) || allocated)) {
335 // arguments have already been recognized as escaping
336 } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
337 set_method_escape(arg);
338 must_record_dependencies = true;
339 } else {
340 set_global_escape(arg);
341 }
342 }
343 _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
344
345 // record dependencies if at least one parameter retained stack-allocatable
346 if (must_record_dependencies) {
347 if (code == Bytecodes::_invokeinterface ||
348 (code == Bytecodes::_invokevirtual && !target->is_final_method())) {
349 _dependencies.append(actual_recv);
350 _dependencies.append(inline_target);
351 }
352 _dependencies.appendAll(analyzer.dependencies());
353 }
354 } else {
355 TRACE_BCEA(1, tty->print_cr("[EA] virtual method %s is not monomorphic.",
356 target->name()->as_utf8()));
357 // conservatively mark all actual parameters as escaping globally
358 for (i = 0; i < arg_size; i++) {
359 ArgumentMap arg = state.raw_pop();
360 if (!is_argument(arg))
361 continue;
362 set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
363 set_global_escape(arg);
364 }
365 _unknown_modified = true; // assume the worst since we don't know the called method
366 }
367 }
368
369 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
370 return ((~arg_set1) | arg_set2) == 0;
371 }
372
373
374 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
375
376 blk->set_processed();
377 ciBytecodeStream s(method());
378 int limit_bci = blk->limit_bci();
379 bool fall_through = false;
380 ArgumentMap allocated_obj;
381 allocated_obj.add_allocated();
382 ArgumentMap unknown_obj;
383 unknown_obj.add_unknown();
384 ArgumentMap empty_map;
385
386 s.reset_to_bci(blk->start_bci());
387 while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
388 fall_through = true;
389 switch (s.cur_bc()) {
390 case Bytecodes::_nop:
391 break;
392 case Bytecodes::_aconst_null:
393 state.apush(unknown_obj);
394 break;
395 case Bytecodes::_iconst_m1:
396 case Bytecodes::_iconst_0:
397 case Bytecodes::_iconst_1:
398 case Bytecodes::_iconst_2:
399 case Bytecodes::_iconst_3:
400 case Bytecodes::_iconst_4:
401 case Bytecodes::_iconst_5:
402 case Bytecodes::_fconst_0:
403 case Bytecodes::_fconst_1:
404 case Bytecodes::_fconst_2:
405 case Bytecodes::_bipush:
406 case Bytecodes::_sipush:
407 state.spush();
408 break;
409 case Bytecodes::_lconst_0:
410 case Bytecodes::_lconst_1:
411 case Bytecodes::_dconst_0:
412 case Bytecodes::_dconst_1:
413 state.lpush();
414 break;
415 case Bytecodes::_ldc:
416 case Bytecodes::_ldc_w:
417 case Bytecodes::_ldc2_w:
418 {
419 // Avoid calling get_constant() which will try to allocate
420 // unloaded constant. We need only constant's type.
421 int index = s.get_constant_pool_index();
422 constantTag tag = s.get_constant_pool_tag(index);
423 if (tag.is_long() || tag.is_double()) {
424 // Only longs and doubles use 2 stack slots.
425 state.lpush();
426 } else if (tag.basic_type() == T_OBJECT) {
427 state.apush(unknown_obj);
428 } else {
429 state.spush();
430 }
431 break;
432 }
433 case Bytecodes::_aload:
434 state.apush(state._vars[s.get_index()]);
435 break;
436 case Bytecodes::_iload:
437 case Bytecodes::_fload:
438 case Bytecodes::_iload_0:
439 case Bytecodes::_iload_1:
440 case Bytecodes::_iload_2:
441 case Bytecodes::_iload_3:
442 case Bytecodes::_fload_0:
443 case Bytecodes::_fload_1:
444 case Bytecodes::_fload_2:
445 case Bytecodes::_fload_3:
446 state.spush();
447 break;
448 case Bytecodes::_lload:
449 case Bytecodes::_dload:
450 case Bytecodes::_lload_0:
451 case Bytecodes::_lload_1:
452 case Bytecodes::_lload_2:
453 case Bytecodes::_lload_3:
454 case Bytecodes::_dload_0:
455 case Bytecodes::_dload_1:
456 case Bytecodes::_dload_2:
457 case Bytecodes::_dload_3:
458 state.lpush();
459 break;
460 case Bytecodes::_aload_0:
461 state.apush(state._vars[0]);
462 break;
463 case Bytecodes::_aload_1:
464 state.apush(state._vars[1]);
465 break;
466 case Bytecodes::_aload_2:
467 state.apush(state._vars[2]);
468 break;
469 case Bytecodes::_aload_3:
470 state.apush(state._vars[3]);
471 break;
472 case Bytecodes::_iaload:
473 case Bytecodes::_faload:
474 case Bytecodes::_baload:
475 case Bytecodes::_caload:
476 case Bytecodes::_saload:
477 state.spop();
478 set_method_escape(state.apop());
479 state.spush();
480 break;
481 case Bytecodes::_laload:
482 case Bytecodes::_daload:
483 state.spop();
484 set_method_escape(state.apop());
485 state.lpush();
486 break;
487 case Bytecodes::_aaload:
488 { state.spop();
489 ArgumentMap array = state.apop();
490 set_method_escape(array);
491 state.apush(unknown_obj);
492 set_dirty(array);
493 }
494 break;
495 case Bytecodes::_istore:
496 case Bytecodes::_fstore:
497 case Bytecodes::_istore_0:
498 case Bytecodes::_istore_1:
499 case Bytecodes::_istore_2:
500 case Bytecodes::_istore_3:
501 case Bytecodes::_fstore_0:
502 case Bytecodes::_fstore_1:
503 case Bytecodes::_fstore_2:
504 case Bytecodes::_fstore_3:
505 state.spop();
506 break;
507 case Bytecodes::_lstore:
508 case Bytecodes::_dstore:
509 case Bytecodes::_lstore_0:
510 case Bytecodes::_lstore_1:
511 case Bytecodes::_lstore_2:
512 case Bytecodes::_lstore_3:
513 case Bytecodes::_dstore_0:
514 case Bytecodes::_dstore_1:
515 case Bytecodes::_dstore_2:
516 case Bytecodes::_dstore_3:
517 state.lpop();
518 break;
519 case Bytecodes::_astore:
520 state._vars[s.get_index()] = state.apop();
521 break;
522 case Bytecodes::_astore_0:
523 state._vars[0] = state.apop();
524 break;
525 case Bytecodes::_astore_1:
526 state._vars[1] = state.apop();
527 break;
528 case Bytecodes::_astore_2:
529 state._vars[2] = state.apop();
530 break;
531 case Bytecodes::_astore_3:
532 state._vars[3] = state.apop();
533 break;
534 case Bytecodes::_iastore:
535 case Bytecodes::_fastore:
536 case Bytecodes::_bastore:
537 case Bytecodes::_castore:
538 case Bytecodes::_sastore:
539 {
540 state.spop();
541 state.spop();
542 ArgumentMap arr = state.apop();
543 set_method_escape(arr);
544 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
545 break;
546 }
547 case Bytecodes::_lastore:
548 case Bytecodes::_dastore:
549 {
550 state.lpop();
551 state.spop();
552 ArgumentMap arr = state.apop();
553 set_method_escape(arr);
554 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
555 break;
556 }
557 case Bytecodes::_aastore:
558 {
559 set_global_escape(state.apop());
560 state.spop();
561 ArgumentMap arr = state.apop();
562 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
563 break;
564 }
565 // the vastore case below should be refactored to the aastore case above
566 // case Bytecodes::_vastore:
567 // {
568 // set_global_escape(state.apop());
569 // state.spop();
570 // ArgumentMap arr = state.apop();
571 // // If the array is flattened, a larger part of it is modified than
572 // // the size of a reference. However, if OFFSET_ANY is given as
573 // // parameter to set_modified(), size is not taken into account.
574 // set_modified(arr, OFFSET_ANY, type2size[T_VALUETYPE]*HeapWordSize);
575 // break;
576 // }
577 case Bytecodes::_pop:
578 state.raw_pop();
579 break;
580 case Bytecodes::_pop2:
581 state.raw_pop();
582 state.raw_pop();
583 break;
584 case Bytecodes::_dup:
585 { ArgumentMap w1 = state.raw_pop();
586 state.raw_push(w1);
587 state.raw_push(w1);
588 }
589 break;
590 case Bytecodes::_dup_x1:
591 { ArgumentMap w1 = state.raw_pop();
592 ArgumentMap w2 = state.raw_pop();
593 state.raw_push(w1);
594 state.raw_push(w2);
595 state.raw_push(w1);
596 }
597 break;
598 case Bytecodes::_dup_x2:
599 { ArgumentMap w1 = state.raw_pop();
600 ArgumentMap w2 = state.raw_pop();
601 ArgumentMap w3 = state.raw_pop();
602 state.raw_push(w1);
603 state.raw_push(w3);
604 state.raw_push(w2);
605 state.raw_push(w1);
606 }
607 break;
608 case Bytecodes::_dup2:
609 { ArgumentMap w1 = state.raw_pop();
610 ArgumentMap w2 = state.raw_pop();
611 state.raw_push(w2);
612 state.raw_push(w1);
613 state.raw_push(w2);
614 state.raw_push(w1);
615 }
616 break;
617 case Bytecodes::_dup2_x1:
618 { ArgumentMap w1 = state.raw_pop();
619 ArgumentMap w2 = state.raw_pop();
620 ArgumentMap w3 = state.raw_pop();
621 state.raw_push(w2);
622 state.raw_push(w1);
623 state.raw_push(w3);
624 state.raw_push(w2);
625 state.raw_push(w1);
626 }
627 break;
628 case Bytecodes::_dup2_x2:
629 { ArgumentMap w1 = state.raw_pop();
630 ArgumentMap w2 = state.raw_pop();
631 ArgumentMap w3 = state.raw_pop();
632 ArgumentMap w4 = state.raw_pop();
633 state.raw_push(w2);
634 state.raw_push(w1);
635 state.raw_push(w4);
636 state.raw_push(w3);
637 state.raw_push(w2);
638 state.raw_push(w1);
639 }
640 break;
641 case Bytecodes::_swap:
642 { ArgumentMap w1 = state.raw_pop();
643 ArgumentMap w2 = state.raw_pop();
644 state.raw_push(w1);
645 state.raw_push(w2);
646 }
647 break;
648 case Bytecodes::_iadd:
649 case Bytecodes::_fadd:
650 case Bytecodes::_isub:
651 case Bytecodes::_fsub:
652 case Bytecodes::_imul:
653 case Bytecodes::_fmul:
654 case Bytecodes::_idiv:
655 case Bytecodes::_fdiv:
656 case Bytecodes::_irem:
657 case Bytecodes::_frem:
658 case Bytecodes::_iand:
659 case Bytecodes::_ior:
660 case Bytecodes::_ixor:
661 state.spop();
662 state.spop();
663 state.spush();
664 break;
665 case Bytecodes::_ladd:
666 case Bytecodes::_dadd:
667 case Bytecodes::_lsub:
668 case Bytecodes::_dsub:
669 case Bytecodes::_lmul:
670 case Bytecodes::_dmul:
671 case Bytecodes::_ldiv:
672 case Bytecodes::_ddiv:
673 case Bytecodes::_lrem:
674 case Bytecodes::_drem:
675 case Bytecodes::_land:
676 case Bytecodes::_lor:
677 case Bytecodes::_lxor:
678 state.lpop();
679 state.lpop();
680 state.lpush();
681 break;
682 case Bytecodes::_ishl:
683 case Bytecodes::_ishr:
684 case Bytecodes::_iushr:
685 state.spop();
686 state.spop();
687 state.spush();
688 break;
689 case Bytecodes::_lshl:
690 case Bytecodes::_lshr:
691 case Bytecodes::_lushr:
692 state.spop();
693 state.lpop();
694 state.lpush();
695 break;
696 case Bytecodes::_ineg:
697 case Bytecodes::_fneg:
698 state.spop();
699 state.spush();
700 break;
701 case Bytecodes::_lneg:
702 case Bytecodes::_dneg:
703 state.lpop();
704 state.lpush();
705 break;
706 case Bytecodes::_iinc:
707 break;
708 case Bytecodes::_i2l:
709 case Bytecodes::_i2d:
710 case Bytecodes::_f2l:
711 case Bytecodes::_f2d:
712 state.spop();
713 state.lpush();
714 break;
715 case Bytecodes::_i2f:
716 case Bytecodes::_f2i:
717 state.spop();
718 state.spush();
719 break;
720 case Bytecodes::_l2i:
721 case Bytecodes::_l2f:
722 case Bytecodes::_d2i:
723 case Bytecodes::_d2f:
724 state.lpop();
725 state.spush();
726 break;
727 case Bytecodes::_l2d:
728 case Bytecodes::_d2l:
729 state.lpop();
730 state.lpush();
731 break;
732 case Bytecodes::_i2b:
733 case Bytecodes::_i2c:
734 case Bytecodes::_i2s:
735 state.spop();
736 state.spush();
737 break;
738 case Bytecodes::_lcmp:
739 case Bytecodes::_dcmpl:
740 case Bytecodes::_dcmpg:
741 state.lpop();
742 state.lpop();
743 state.spush();
744 break;
745 case Bytecodes::_fcmpl:
746 case Bytecodes::_fcmpg:
747 state.spop();
748 state.spop();
749 state.spush();
750 break;
751 case Bytecodes::_ifeq:
752 case Bytecodes::_ifne:
753 case Bytecodes::_iflt:
754 case Bytecodes::_ifge:
755 case Bytecodes::_ifgt:
756 case Bytecodes::_ifle:
757 {
758 state.spop();
759 int dest_bci = s.get_dest();
760 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
761 assert(s.next_bci() == limit_bci, "branch must end block");
762 successors.push(_methodBlocks->block_containing(dest_bci));
763 break;
764 }
765 case Bytecodes::_if_icmpeq:
766 case Bytecodes::_if_icmpne:
767 case Bytecodes::_if_icmplt:
768 case Bytecodes::_if_icmpge:
769 case Bytecodes::_if_icmpgt:
770 case Bytecodes::_if_icmple:
771 {
772 state.spop();
773 state.spop();
774 int dest_bci = s.get_dest();
775 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
776 assert(s.next_bci() == limit_bci, "branch must end block");
777 successors.push(_methodBlocks->block_containing(dest_bci));
778 break;
779 }
780 case Bytecodes::_if_acmpeq:
781 case Bytecodes::_if_acmpne:
782 {
783 set_method_escape(state.apop());
784 set_method_escape(state.apop());
785 int dest_bci = s.get_dest();
786 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
787 assert(s.next_bci() == limit_bci, "branch must end block");
788 successors.push(_methodBlocks->block_containing(dest_bci));
789 break;
790 }
791 case Bytecodes::_goto:
792 {
793 int dest_bci = s.get_dest();
794 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
795 assert(s.next_bci() == limit_bci, "branch must end block");
796 successors.push(_methodBlocks->block_containing(dest_bci));
797 fall_through = false;
798 break;
799 }
800 case Bytecodes::_jsr:
801 {
802 int dest_bci = s.get_dest();
803 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
804 assert(s.next_bci() == limit_bci, "branch must end block");
805 state.apush(empty_map);
806 successors.push(_methodBlocks->block_containing(dest_bci));
807 fall_through = false;
808 break;
809 }
810 case Bytecodes::_ret:
811 // we don't track the destination of a "ret" instruction
812 assert(s.next_bci() == limit_bci, "branch must end block");
813 fall_through = false;
814 break;
815 case Bytecodes::_return:
816 assert(s.next_bci() == limit_bci, "return must end block");
817 fall_through = false;
818 break;
819 case Bytecodes::_tableswitch:
820 {
821 state.spop();
822 Bytecode_tableswitch sw(&s);
823 int len = sw.length();
824 int dest_bci;
825 for (int i = 0; i < len; i++) {
826 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
827 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
828 successors.push(_methodBlocks->block_containing(dest_bci));
829 }
830 dest_bci = s.cur_bci() + sw.default_offset();
831 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
832 successors.push(_methodBlocks->block_containing(dest_bci));
833 assert(s.next_bci() == limit_bci, "branch must end block");
834 fall_through = false;
835 break;
836 }
837 case Bytecodes::_lookupswitch:
838 {
839 state.spop();
840 Bytecode_lookupswitch sw(&s);
841 int len = sw.number_of_pairs();
842 int dest_bci;
843 for (int i = 0; i < len; i++) {
844 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
845 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
846 successors.push(_methodBlocks->block_containing(dest_bci));
847 }
848 dest_bci = s.cur_bci() + sw.default_offset();
849 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
850 successors.push(_methodBlocks->block_containing(dest_bci));
851 fall_through = false;
852 break;
853 }
854 case Bytecodes::_ireturn:
855 case Bytecodes::_freturn:
856 state.spop();
857 fall_through = false;
858 break;
859 case Bytecodes::_lreturn:
860 case Bytecodes::_dreturn:
861 state.lpop();
862 fall_through = false;
863 break;
864 case Bytecodes::_areturn:
865 set_returned(state.apop());
866 fall_through = false;
867 break;
868 case Bytecodes::_getstatic:
869 case Bytecodes::_getfield:
870 { bool ignored_will_link;
871 ciField* field = s.get_field(ignored_will_link);
872 BasicType field_type = field->type()->basic_type();
873 if (s.cur_bc() != Bytecodes::_getstatic) {
874 set_method_escape(state.apop());
875 }
876 if (field_type == T_OBJECT || field_type == T_ARRAY) {
877 state.apush(unknown_obj);
878 } else if (type2size[field_type] == 1) {
879 state.spush();
880 } else {
881 state.lpush();
882 }
883 }
884 break;
885 case Bytecodes::_putstatic:
886 case Bytecodes::_putfield:
887 { bool will_link;
888 ciField* field = s.get_field(will_link);
889 BasicType field_type = field->type()->basic_type();
890 if (field_type == T_OBJECT || field_type == T_ARRAY) {
891 set_global_escape(state.apop());
892 } else if (type2size[field_type] == 1) {
893 state.spop();
894 } else {
895 state.lpop();
896 }
897 if (s.cur_bc() != Bytecodes::_putstatic) {
898 ArgumentMap p = state.apop();
899 set_method_escape(p);
900 set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
901 }
902 }
903 break;
904 case Bytecodes::_invokevirtual:
905 case Bytecodes::_invokespecial:
906 case Bytecodes::_invokestatic:
907 case Bytecodes::_invokedynamic:
908 case Bytecodes::_invokeinterface:
909 { bool ignored_will_link;
910 ciSignature* declared_signature = NULL;
911 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
912 ciKlass* holder = s.get_declared_method_holder();
913 assert(declared_signature != NULL, "cannot be null");
914 // If the current bytecode has an attached appendix argument,
915 // push an unknown object to represent that argument. (Analysis
916 // of dynamic call sites, especially invokehandle calls, needs
917 // the appendix argument on the stack, in addition to "regular" arguments
918 // pushed onto the stack by bytecode instructions preceding the call.)
919 //
920 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
921 // method to determine whether the current bytecode has an appendix argument.
922 // The has_appendix() method obtains the appendix from the
923 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
924 // resolution of dynamic call sites. Callees in the
925 // ciBytecodeStream::get_method() call above also access the _f1 field;
926 // interleaving the get_method() and has_appendix() calls in the current
927 // method with call site resolution can lead to an inconsistent view of
928 // the current method's argument count. In particular, some interleaving(s)
929 // can cause the method's argument count to not include the appendix, which
930 // then leads to stack over-/underflow in the escape analyzer.
931 //
932 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
933 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
934 // instructions, except if the call site is the _invokeBasic intrinsic
935 // (that intrinsic is always targeted by an invokehandle instruction but does
936 // not have an appendix argument).
937 if (target->is_loaded() &&
938 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
939 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
940 state.apush(unknown_obj);
941 }
942 // Pass in raw bytecode because we need to see invokehandle instructions.
943 invoke(state, s.cur_bc_raw(), target, holder);
944 // We are using the return type of the declared signature here because
945 // it might be a more concrete type than the one from the target (for
946 // e.g. invokedynamic and invokehandle).
947 ciType* return_type = declared_signature->return_type();
948 if (!return_type->is_primitive_type()) {
949 state.apush(unknown_obj);
950 } else if (return_type->is_one_word()) {
951 state.spush();
952 } else if (return_type->is_two_word()) {
953 state.lpush();
954 }
955 }
956 break;
957 case Bytecodes::_new:
958 case Bytecodes::_defaultvalue:
959 state.apush(allocated_obj);
960 break;
961 case Bytecodes::_withfield: {
962 bool will_link;
963 ciField* field = s.get_field(will_link);
964 BasicType field_type = field->type()->basic_type();
965 if (field_type == T_OBJECT || field_type == T_ARRAY) {
966 set_global_escape(state.apop());
967 } else if (type2size[field_type] == 1) {
968 state.spop();
969 } else {
970 state.lpop();
971 }
972 set_method_escape(state.apop());
973 state.apush(allocated_obj);
974 break;
975 }
976 case Bytecodes::_newarray:
977 case Bytecodes::_anewarray:
978 state.spop();
979 state.apush(allocated_obj);
980 break;
981 case Bytecodes::_multianewarray:
982 { int i = s.cur_bcp()[3];
983 while (i-- > 0) state.spop();
984 state.apush(allocated_obj);
985 }
986 break;
987 case Bytecodes::_arraylength:
988 set_method_escape(state.apop());
989 state.spush();
990 break;
991 case Bytecodes::_athrow:
992 set_global_escape(state.apop());
993 fall_through = false;
994 break;
995 case Bytecodes::_checkcast:
996 { ArgumentMap obj = state.apop();
997 set_method_escape(obj);
998 state.apush(obj);
999 }
1000 break;
1001 case Bytecodes::_instanceof:
1002 set_method_escape(state.apop());
1003 state.spush();
1004 break;
1005 case Bytecodes::_monitorenter:
1006 case Bytecodes::_monitorexit:
1007 state.apop();
1008 break;
1009 case Bytecodes::_wide:
1010 ShouldNotReachHere();
1011 break;
1012 case Bytecodes::_ifnull:
1013 case Bytecodes::_ifnonnull:
1014 {
1015 set_method_escape(state.apop());
1016 int dest_bci = s.get_dest();
1017 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1018 assert(s.next_bci() == limit_bci, "branch must end block");
1019 successors.push(_methodBlocks->block_containing(dest_bci));
1020 break;
1021 }
1022 case Bytecodes::_goto_w:
1023 {
1024 int dest_bci = s.get_far_dest();
1025 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1026 assert(s.next_bci() == limit_bci, "branch must end block");
1027 successors.push(_methodBlocks->block_containing(dest_bci));
1028 fall_through = false;
1029 break;
1030 }
1031 case Bytecodes::_jsr_w:
1032 {
1033 int dest_bci = s.get_far_dest();
1034 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1035 assert(s.next_bci() == limit_bci, "branch must end block");
1036 state.apush(empty_map);
1037 successors.push(_methodBlocks->block_containing(dest_bci));
1038 fall_through = false;
1039 break;
1040 }
1041 case Bytecodes::_breakpoint:
1042 break;
1043 default:
1044 ShouldNotReachHere();
1045 break;
1046 }
1047
1048 }
1049 if (fall_through) {
1050 int fall_through_bci = s.cur_bci();
1051 if (fall_through_bci < _method->code_size()) {
1052 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1053 successors.push(_methodBlocks->block_containing(fall_through_bci));
1054 }
1055 }
1056 }
1057
1058 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1059 StateInfo *d_state = blockstates + dest->index();
1060 int nlocals = _method->max_locals();
1061
1062 // exceptions may cause transfer of control to handlers in the middle of a
1063 // block, so we don't merge the incoming state of exception handlers
1064 if (dest->is_handler())
1065 return;
1066 if (!d_state->_initialized ) {
1067 // destination not initialized, just copy
1068 for (int i = 0; i < nlocals; i++) {
1069 d_state->_vars[i] = s_state->_vars[i];
1070 }
1071 for (int i = 0; i < s_state->_stack_height; i++) {
1072 d_state->_stack[i] = s_state->_stack[i];
1073 }
1074 d_state->_stack_height = s_state->_stack_height;
1075 d_state->_max_stack = s_state->_max_stack;
1076 d_state->_initialized = true;
1077 } else if (!dest->processed()) {
1078 // we have not yet walked the bytecodes of dest, we can merge
1079 // the states
1080 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1081 for (int i = 0; i < nlocals; i++) {
1082 d_state->_vars[i].set_union(s_state->_vars[i]);
1083 }
1084 for (int i = 0; i < s_state->_stack_height; i++) {
1085 d_state->_stack[i].set_union(s_state->_stack[i]);
1086 }
1087 } else {
1088 // the bytecodes of dest have already been processed, mark any
1089 // arguments in the source state which are not in the dest state
1090 // as global escape.
1091 // Future refinement: we only need to mark these variable to the
1092 // maximum escape of any variables in dest state
1093 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1094 ArgumentMap extra_vars;
1095 for (int i = 0; i < nlocals; i++) {
1096 ArgumentMap t;
1097 t = s_state->_vars[i];
1098 t.set_difference(d_state->_vars[i]);
1099 extra_vars.set_union(t);
1100 }
1101 for (int i = 0; i < s_state->_stack_height; i++) {
1102 ArgumentMap t;
1103 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1104 t.clear();
1105 t = s_state->_stack[i];
1106 t.set_difference(d_state->_stack[i]);
1107 extra_vars.set_union(t);
1108 }
1109 set_global_escape(extra_vars, true);
1110 }
1111 }
1112
1113 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1114 int numblocks = _methodBlocks->num_blocks();
1115 int stkSize = _method->max_stack();
1116 int numLocals = _method->max_locals();
1117 StateInfo state;
1118
1119 int datacount = (numblocks + 1) * (stkSize + numLocals);
1120 int datasize = datacount * sizeof(ArgumentMap);
1121 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1122 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1123 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1124 ArgumentMap *dp = statedata;
1125 state._vars = dp;
1126 dp += numLocals;
1127 state._stack = dp;
1128 dp += stkSize;
1129 state._initialized = false;
1130 state._max_stack = stkSize;
1131 for (int i = 0; i < numblocks; i++) {
1132 blockstates[i]._vars = dp;
1133 dp += numLocals;
1134 blockstates[i]._stack = dp;
1135 dp += stkSize;
1136 blockstates[i]._initialized = false;
1137 blockstates[i]._stack_height = 0;
1138 blockstates[i]._max_stack = stkSize;
1139 }
1140 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
1141 GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
1142
1143 _methodBlocks->clear_processed();
1144
1145 // initialize block 0 state from method signature
1146 ArgumentMap allVars; // all oop arguments to method
1147 ciSignature* sig = method()->signature();
1148 int j = 0;
1149 ciBlock* first_blk = _methodBlocks->block_containing(0);
1150 int fb_i = first_blk->index();
1151 if (!method()->is_static()) {
1152 // record information for "this"
1153 blockstates[fb_i]._vars[j].set(j);
1154 allVars.add(j);
1155 j++;
1156 }
1157 for (int i = 0; i < sig->count(); i++) {
1158 ciType* t = sig->type_at(i);
1159 if (!t->is_primitive_type()) {
1160 blockstates[fb_i]._vars[j].set(j);
1161 allVars.add(j);
1162 }
1163 j += t->size();
1164 }
1165 blockstates[fb_i]._initialized = true;
1166 assert(j == _arg_size, "just checking");
1167
1168 ArgumentMap unknown_map;
1169 unknown_map.add_unknown();
1170
1171 worklist.push(first_blk);
1172 while(worklist.length() > 0) {
1173 ciBlock *blk = worklist.pop();
1174 StateInfo *blkState = blockstates + blk->index();
1175 if (blk->is_handler() || blk->is_ret_target()) {
1176 // for an exception handler or a target of a ret instruction, we assume the worst case,
1177 // that any variable could contain any argument
1178 for (int i = 0; i < numLocals; i++) {
1179 state._vars[i] = allVars;
1180 }
1181 if (blk->is_handler()) {
1182 state._stack_height = 1;
1183 } else {
1184 state._stack_height = blkState->_stack_height;
1185 }
1186 for (int i = 0; i < state._stack_height; i++) {
1187 // ??? should this be unknown_map ???
1188 state._stack[i] = allVars;
1189 }
1190 } else {
1191 for (int i = 0; i < numLocals; i++) {
1192 state._vars[i] = blkState->_vars[i];
1193 }
1194 for (int i = 0; i < blkState->_stack_height; i++) {
1195 state._stack[i] = blkState->_stack[i];
1196 }
1197 state._stack_height = blkState->_stack_height;
1198 }
1199 iterate_one_block(blk, state, successors);
1200 // if this block has any exception handlers, push them
1201 // onto successor list
1202 if (blk->has_handler()) {
1203 DEBUG_ONLY(int handler_count = 0;)
1204 int blk_start = blk->start_bci();
1205 int blk_end = blk->limit_bci();
1206 for (int i = 0; i < numblocks; i++) {
1207 ciBlock *b = _methodBlocks->block(i);
1208 if (b->is_handler()) {
1209 int ex_start = b->ex_start_bci();
1210 int ex_end = b->ex_limit_bci();
1211 if ((ex_start >= blk_start && ex_start < blk_end) ||
1212 (ex_end > blk_start && ex_end <= blk_end)) {
1213 successors.push(b);
1214 }
1215 DEBUG_ONLY(handler_count++;)
1216 }
1217 }
1218 assert(handler_count > 0, "must find at least one handler");
1219 }
1220 // merge computed variable state with successors
1221 while(successors.length() > 0) {
1222 ciBlock *succ = successors.pop();
1223 merge_block_states(blockstates, succ, &state);
1224 if (!succ->processed())
1225 worklist.push(succ);
1226 }
1227 }
1228 }
1229
1230 bool BCEscapeAnalyzer::do_analysis() {
1231 Arena* arena = CURRENT_ENV->arena();
1232 // identify basic blocks
1233 _methodBlocks = _method->get_method_blocks();
1234
1235 iterate_blocks(arena);
1236 // TEMPORARY
1237 return true;
1238 }
1239
1240 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
1241 vmIntrinsics::ID iid = method()->intrinsic_id();
1242
1243 if (iid == vmIntrinsics::_getClass ||
1244 iid == vmIntrinsics::_hashCode)
1245 return iid;
1246 else
1247 return vmIntrinsics::_none;
1248 }
1249
1250 bool BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
1251 ArgumentMap arg;
1252 arg.clear();
1253 switch (iid) {
1254 case vmIntrinsics::_getClass:
1255 _return_local = false;
1256 break;
1257 case vmIntrinsics::_hashCode:
1258 // initialized state is correct
1259 break;
1260 default:
1261 assert(false, "unexpected intrinsic");
1262 }
1263 return true;
1264 }
1265
1266 void BCEscapeAnalyzer::initialize() {
1267 int i;
1268
1269 // clear escape information (method may have been deoptimized)
1270 methodData()->clear_escape_info();
1271
1272 // initialize escape state of object parameters
1273 ciSignature* sig = method()->signature();
1274 int j = 0;
1275 if (!method()->is_static()) {
1276 _arg_local.set(0);
1277 _arg_stack.set(0);
1278 j++;
1279 }
1280 for (i = 0; i < sig->count(); i++) {
1281 ciType* t = sig->type_at(i);
1282 if (!t->is_primitive_type()) {
1283 _arg_local.set(j);
1284 _arg_stack.set(j);
1285 }
1286 j += t->size();
1287 }
1288 assert(j == _arg_size, "just checking");
1289
1290 // start with optimistic assumption
1291 ciType *rt = _method->return_type();
1292 if (rt->is_primitive_type()) {
1293 _return_local = false;
1294 _return_allocated = false;
1295 } else {
1296 _return_local = true;
1297 _return_allocated = true;
1298 }
1299 _allocated_escapes = false;
1300 _unknown_modified = false;
1301 }
1302
1303 void BCEscapeAnalyzer::clear_escape_info() {
1304 ciSignature* sig = method()->signature();
1305 int arg_count = sig->count();
1306 ArgumentMap var;
1307 if (!method()->is_static()) {
1308 arg_count++; // allow for "this"
1309 }
1310 for (int i = 0; i < arg_count; i++) {
1311 set_arg_modified(i, OFFSET_ANY, 4);
1312 var.clear();
1313 var.set(i);
1314 set_modified(var, OFFSET_ANY, 4);
1315 set_global_escape(var);
1316 }
1317 _arg_local.Clear();
1318 _arg_stack.Clear();
1319 _arg_returned.Clear();
1320 _return_local = false;
1321 _return_allocated = false;
1322 _allocated_escapes = true;
1323 _unknown_modified = true;
1324 }
1325
1326
1327 void BCEscapeAnalyzer::compute_escape_info() {
1328 int i;
1329 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1330
1331 vmIntrinsics::ID iid = known_intrinsic();
1332
1333 // check if method can be analyzed
1334 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1335 || _level > MaxBCEAEstimateLevel
1336 || method()->code_size() > MaxBCEAEstimateSize)) {
1337 if (BCEATraceLevel >= 1) {
1338 tty->print("Skipping method because: ");
1339 if (method()->is_abstract())
1340 tty->print_cr("method is abstract.");
1341 else if (method()->is_native())
1342 tty->print_cr("method is native.");
1343 else if (!method()->holder()->is_initialized())
1344 tty->print_cr("class of method is not initialized.");
1345 else if (_level > MaxBCEAEstimateLevel)
1346 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1347 _level, (int) MaxBCEAEstimateLevel);
1348 else if (method()->code_size() > MaxBCEAEstimateSize)
1349 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1350 method()->code_size(), (int) MaxBCEAEstimateSize);
1351 else
1352 ShouldNotReachHere();
1353 }
1354 clear_escape_info();
1355
1356 return;
1357 }
1358
1359 if (BCEATraceLevel >= 1) {
1360 tty->print("[EA] estimating escape information for");
1361 if (iid != vmIntrinsics::_none)
1362 tty->print(" intrinsic");
1363 method()->print_short_name();
1364 tty->print_cr(" (%d bytes)", method()->code_size());
1365 }
1366
1367 bool success;
1368
1369 initialize();
1370
1371 // Do not scan method if it has no object parameters and
1372 // does not returns an object (_return_allocated is set in initialize()).
1373 if (_arg_local.Size() == 0 && !_return_allocated) {
1374 // Clear all info since method's bytecode was not analysed and
1375 // set pessimistic escape information.
1376 clear_escape_info();
1377 methodData()->set_eflag(MethodData::allocated_escapes);
1378 methodData()->set_eflag(MethodData::unknown_modified);
1379 methodData()->set_eflag(MethodData::estimated);
1380 return;
1381 }
1382
1383 if (iid != vmIntrinsics::_none)
1384 success = compute_escape_for_intrinsic(iid);
1385 else {
1386 success = do_analysis();
1387 }
1388
1389 // don't store interprocedural escape information if it introduces
1390 // dependencies or if method data is empty
1391 //
1392 if (!has_dependencies() && !methodData()->is_empty()) {
1393 for (i = 0; i < _arg_size; i++) {
1394 if (_arg_local.test(i)) {
1395 assert(_arg_stack.test(i), "inconsistent escape info");
1396 methodData()->set_arg_local(i);
1397 methodData()->set_arg_stack(i);
1398 } else if (_arg_stack.test(i)) {
1399 methodData()->set_arg_stack(i);
1400 }
1401 if (_arg_returned.test(i)) {
1402 methodData()->set_arg_returned(i);
1403 }
1404 methodData()->set_arg_modified(i, _arg_modified[i]);
1405 }
1406 if (_return_local) {
1407 methodData()->set_eflag(MethodData::return_local);
1408 }
1409 if (_return_allocated) {
1410 methodData()->set_eflag(MethodData::return_allocated);
1411 }
1412 if (_allocated_escapes) {
1413 methodData()->set_eflag(MethodData::allocated_escapes);
1414 }
1415 if (_unknown_modified) {
1416 methodData()->set_eflag(MethodData::unknown_modified);
1417 }
1418 methodData()->set_eflag(MethodData::estimated);
1419 }
1420 }
1421
1422 void BCEscapeAnalyzer::read_escape_info() {
1423 assert(methodData()->has_escape_info(), "no escape info available");
1424
1425 // read escape information from method descriptor
1426 for (int i = 0; i < _arg_size; i++) {
1427 if (methodData()->is_arg_local(i))
1428 _arg_local.set(i);
1429 if (methodData()->is_arg_stack(i))
1430 _arg_stack.set(i);
1431 if (methodData()->is_arg_returned(i))
1432 _arg_returned.set(i);
1433 _arg_modified[i] = methodData()->arg_modified(i);
1434 }
1435 _return_local = methodData()->eflag_set(MethodData::return_local);
1436 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1437 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1438 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1439
1440 }
1441
1442 #ifndef PRODUCT
1443 void BCEscapeAnalyzer::dump() {
1444 tty->print("[EA] estimated escape information for");
1445 method()->print_short_name();
1446 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1447 tty->print(" non-escaping args: ");
1448 _arg_local.print();
1449 tty->print(" stack-allocatable args: ");
1450 _arg_stack.print();
1451 if (_return_local) {
1452 tty->print(" returned args: ");
1453 _arg_returned.print();
1454 } else if (is_return_allocated()) {
1455 tty->print_cr(" return allocated value");
1456 } else {
1457 tty->print_cr(" return non-local value");
1458 }
1459 tty->print(" modified args: ");
1460 for (int i = 0; i < _arg_size; i++) {
1461 if (_arg_modified[i] == 0)
1462 tty->print(" 0");
1463 else
1464 tty->print(" 0x%x", _arg_modified[i]);
1465 }
1466 tty->cr();
1467 tty->print(" flags: ");
1468 if (_return_allocated)
1469 tty->print(" return_allocated");
1470 if (_allocated_escapes)
1471 tty->print(" allocated_escapes");
1472 if (_unknown_modified)
1473 tty->print(" unknown_modified");
1474 tty->cr();
1475 }
1476 #endif
1477
1478 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1479 : _conservative(method == NULL || !EstimateArgEscape)
1480 , _arena(CURRENT_ENV->arena())
1481 , _method(method)
1482 , _methodData(method ? method->method_data() : NULL)
1483 , _arg_size(method ? method->arg_size() : 0)
1484 , _arg_local(_arena)
1485 , _arg_stack(_arena)
1486 , _arg_returned(_arena)
1487 , _dirty(_arena)
1488 , _return_local(false)
1489 , _return_allocated(false)
1490 , _allocated_escapes(false)
1491 , _unknown_modified(false)
1492 , _dependencies(_arena, 4, 0, NULL)
1493 , _parent(parent)
1494 , _level(parent == NULL ? 0 : parent->level() + 1) {
1495 if (!_conservative) {
1496 _arg_local.Clear();
1497 _arg_stack.Clear();
1498 _arg_returned.Clear();
1499 _dirty.Clear();
1500 Arena* arena = CURRENT_ENV->arena();
1501 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1502 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1503
1504 if (methodData() == NULL)
1505 return;
1506 if (methodData()->has_escape_info()) {
1507 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1508 method->holder()->name()->as_utf8(),
1509 method->name()->as_utf8()));
1510 read_escape_info();
1511 } else {
1512 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1513 method->holder()->name()->as_utf8(),
1514 method->name()->as_utf8()));
1515
1516 compute_escape_info();
1517 methodData()->update_escape_info();
1518 }
1519 #ifndef PRODUCT
1520 if (BCEATraceLevel >= 3) {
1521 // dump escape information
1522 dump();
1523 }
1524 #endif
1525 }
1526 }
1527
1528 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1529 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1530 // Also record evol dependencies so redefinition of the
1531 // callee will trigger recompilation.
1532 deps->assert_evol_method(method());
1533 }
1534 for (int i = 0; i < _dependencies.length(); i+=2) {
1535 ciKlass *k = _dependencies.at(i)->as_klass();
1536 ciMethod *m = _dependencies.at(i+1)->as_method();
1537 deps->assert_unique_concrete_method(k, m);
1538 }
1539 }