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 case Bytecodes::_vload:
435 state.apush(state._vars[s.get_index()]);
436 break;
437 case Bytecodes::_iload:
438 case Bytecodes::_fload:
439 case Bytecodes::_iload_0:
440 case Bytecodes::_iload_1:
441 case Bytecodes::_iload_2:
442 case Bytecodes::_iload_3:
443 case Bytecodes::_fload_0:
444 case Bytecodes::_fload_1:
445 case Bytecodes::_fload_2:
446 case Bytecodes::_fload_3:
447 state.spush();
448 break;
449 case Bytecodes::_lload:
450 case Bytecodes::_dload:
451 case Bytecodes::_lload_0:
452 case Bytecodes::_lload_1:
453 case Bytecodes::_lload_2:
454 case Bytecodes::_lload_3:
455 case Bytecodes::_dload_0:
456 case Bytecodes::_dload_1:
457 case Bytecodes::_dload_2:
458 case Bytecodes::_dload_3:
459 state.lpush();
460 break;
461 case Bytecodes::_aload_0:
462 state.apush(state._vars[0]);
463 break;
464 case Bytecodes::_aload_1:
465 state.apush(state._vars[1]);
466 break;
467 case Bytecodes::_aload_2:
468 state.apush(state._vars[2]);
469 break;
470 case Bytecodes::_aload_3:
471 state.apush(state._vars[3]);
472 break;
473 case Bytecodes::_iaload:
474 case Bytecodes::_faload:
475 case Bytecodes::_baload:
476 case Bytecodes::_caload:
477 case Bytecodes::_saload:
478 state.spop();
479 set_method_escape(state.apop());
480 state.spush();
481 break;
482 case Bytecodes::_laload:
483 case Bytecodes::_daload:
484 state.spop();
485 set_method_escape(state.apop());
486 state.lpush();
487 break;
488 case Bytecodes::_vaload:
489 case Bytecodes::_aaload:
490 { state.spop();
491 ArgumentMap array = state.apop();
492 set_method_escape(array);
493 state.apush(unknown_obj);
494 set_dirty(array);
495 }
496 break;
497 case Bytecodes::_istore:
498 case Bytecodes::_fstore:
499 case Bytecodes::_istore_0:
500 case Bytecodes::_istore_1:
501 case Bytecodes::_istore_2:
502 case Bytecodes::_istore_3:
503 case Bytecodes::_fstore_0:
504 case Bytecodes::_fstore_1:
505 case Bytecodes::_fstore_2:
506 case Bytecodes::_fstore_3:
507 state.spop();
508 break;
509 case Bytecodes::_lstore:
510 case Bytecodes::_dstore:
511 case Bytecodes::_lstore_0:
512 case Bytecodes::_lstore_1:
513 case Bytecodes::_lstore_2:
514 case Bytecodes::_lstore_3:
515 case Bytecodes::_dstore_0:
516 case Bytecodes::_dstore_1:
517 case Bytecodes::_dstore_2:
518 case Bytecodes::_dstore_3:
519 state.lpop();
520 break;
521 case Bytecodes::_astore:
522 case Bytecodes::_vstore:
523 state._vars[s.get_index()] = state.apop();
524 break;
525 case Bytecodes::_astore_0:
526 state._vars[0] = state.apop();
527 break;
528 case Bytecodes::_astore_1:
529 state._vars[1] = state.apop();
530 break;
531 case Bytecodes::_astore_2:
532 state._vars[2] = state.apop();
533 break;
534 case Bytecodes::_astore_3:
535 state._vars[3] = state.apop();
536 break;
537 case Bytecodes::_iastore:
538 case Bytecodes::_fastore:
539 case Bytecodes::_bastore:
540 case Bytecodes::_castore:
541 case Bytecodes::_sastore:
542 {
543 state.spop();
544 state.spop();
545 ArgumentMap arr = state.apop();
546 set_method_escape(arr);
547 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
548 break;
549 }
550 case Bytecodes::_lastore:
551 case Bytecodes::_dastore:
552 {
553 state.lpop();
554 state.spop();
555 ArgumentMap arr = state.apop();
556 set_method_escape(arr);
557 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
558 break;
559 }
560 case Bytecodes::_aastore:
561 {
562 set_global_escape(state.apop());
563 state.spop();
564 ArgumentMap arr = state.apop();
565 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
566 break;
567 }
568 case Bytecodes::_vastore:
569 {
570 set_global_escape(state.apop());
571 state.spop();
572 ArgumentMap arr = state.apop();
573 // If the array is flattened, a larger part of it is modified than
574 // the size of a reference. However, if OFFSET_ANY is given as
575 // parameter to set_modified(), size is not taken into account.
576 set_modified(arr, OFFSET_ANY, type2size[T_VALUETYPE]*HeapWordSize);
577 break;
578 }
579 case Bytecodes::_pop:
580 state.raw_pop();
581 break;
582 case Bytecodes::_pop2:
583 state.raw_pop();
584 state.raw_pop();
585 break;
586 case Bytecodes::_dup:
587 { ArgumentMap w1 = state.raw_pop();
588 state.raw_push(w1);
589 state.raw_push(w1);
590 }
591 break;
592 case Bytecodes::_dup_x1:
593 { ArgumentMap w1 = state.raw_pop();
594 ArgumentMap w2 = state.raw_pop();
595 state.raw_push(w1);
596 state.raw_push(w2);
597 state.raw_push(w1);
598 }
599 break;
600 case Bytecodes::_dup_x2:
601 { ArgumentMap w1 = state.raw_pop();
602 ArgumentMap w2 = state.raw_pop();
603 ArgumentMap w3 = state.raw_pop();
604 state.raw_push(w1);
605 state.raw_push(w3);
606 state.raw_push(w2);
607 state.raw_push(w1);
608 }
609 break;
610 case Bytecodes::_dup2:
611 { ArgumentMap w1 = state.raw_pop();
612 ArgumentMap w2 = state.raw_pop();
613 state.raw_push(w2);
614 state.raw_push(w1);
615 state.raw_push(w2);
616 state.raw_push(w1);
617 }
618 break;
619 case Bytecodes::_dup2_x1:
620 { ArgumentMap w1 = state.raw_pop();
621 ArgumentMap w2 = state.raw_pop();
622 ArgumentMap w3 = state.raw_pop();
623 state.raw_push(w2);
624 state.raw_push(w1);
625 state.raw_push(w3);
626 state.raw_push(w2);
627 state.raw_push(w1);
628 }
629 break;
630 case Bytecodes::_dup2_x2:
631 { ArgumentMap w1 = state.raw_pop();
632 ArgumentMap w2 = state.raw_pop();
633 ArgumentMap w3 = state.raw_pop();
634 ArgumentMap w4 = state.raw_pop();
635 state.raw_push(w2);
636 state.raw_push(w1);
637 state.raw_push(w4);
638 state.raw_push(w3);
639 state.raw_push(w2);
640 state.raw_push(w1);
641 }
642 break;
643 case Bytecodes::_swap:
644 { ArgumentMap w1 = state.raw_pop();
645 ArgumentMap w2 = state.raw_pop();
646 state.raw_push(w1);
647 state.raw_push(w2);
648 }
649 break;
650 case Bytecodes::_iadd:
651 case Bytecodes::_fadd:
652 case Bytecodes::_isub:
653 case Bytecodes::_fsub:
654 case Bytecodes::_imul:
655 case Bytecodes::_fmul:
656 case Bytecodes::_idiv:
657 case Bytecodes::_fdiv:
658 case Bytecodes::_irem:
659 case Bytecodes::_frem:
660 case Bytecodes::_iand:
661 case Bytecodes::_ior:
662 case Bytecodes::_ixor:
663 state.spop();
664 state.spop();
665 state.spush();
666 break;
667 case Bytecodes::_ladd:
668 case Bytecodes::_dadd:
669 case Bytecodes::_lsub:
670 case Bytecodes::_dsub:
671 case Bytecodes::_lmul:
672 case Bytecodes::_dmul:
673 case Bytecodes::_ldiv:
674 case Bytecodes::_ddiv:
675 case Bytecodes::_lrem:
676 case Bytecodes::_drem:
677 case Bytecodes::_land:
678 case Bytecodes::_lor:
679 case Bytecodes::_lxor:
680 state.lpop();
681 state.lpop();
682 state.lpush();
683 break;
684 case Bytecodes::_ishl:
685 case Bytecodes::_ishr:
686 case Bytecodes::_iushr:
687 state.spop();
688 state.spop();
689 state.spush();
690 break;
691 case Bytecodes::_lshl:
692 case Bytecodes::_lshr:
693 case Bytecodes::_lushr:
694 state.spop();
695 state.lpop();
696 state.lpush();
697 break;
698 case Bytecodes::_ineg:
699 case Bytecodes::_fneg:
700 state.spop();
701 state.spush();
702 break;
703 case Bytecodes::_lneg:
704 case Bytecodes::_dneg:
705 state.lpop();
706 state.lpush();
707 break;
708 case Bytecodes::_iinc:
709 break;
710 case Bytecodes::_i2l:
711 case Bytecodes::_i2d:
712 case Bytecodes::_f2l:
713 case Bytecodes::_f2d:
714 state.spop();
715 state.lpush();
716 break;
717 case Bytecodes::_i2f:
718 case Bytecodes::_f2i:
719 state.spop();
720 state.spush();
721 break;
722 case Bytecodes::_l2i:
723 case Bytecodes::_l2f:
724 case Bytecodes::_d2i:
725 case Bytecodes::_d2f:
726 state.lpop();
727 state.spush();
728 break;
729 case Bytecodes::_l2d:
730 case Bytecodes::_d2l:
731 state.lpop();
732 state.lpush();
733 break;
734 case Bytecodes::_i2b:
735 case Bytecodes::_i2c:
736 case Bytecodes::_i2s:
737 state.spop();
738 state.spush();
739 break;
740 case Bytecodes::_lcmp:
741 case Bytecodes::_dcmpl:
742 case Bytecodes::_dcmpg:
743 state.lpop();
744 state.lpop();
745 state.spush();
746 break;
747 case Bytecodes::_fcmpl:
748 case Bytecodes::_fcmpg:
749 state.spop();
750 state.spop();
751 state.spush();
752 break;
753 case Bytecodes::_ifeq:
754 case Bytecodes::_ifne:
755 case Bytecodes::_iflt:
756 case Bytecodes::_ifge:
757 case Bytecodes::_ifgt:
758 case Bytecodes::_ifle:
759 {
760 state.spop();
761 int dest_bci = s.get_dest();
762 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
763 assert(s.next_bci() == limit_bci, "branch must end block");
764 successors.push(_methodBlocks->block_containing(dest_bci));
765 break;
766 }
767 case Bytecodes::_if_icmpeq:
768 case Bytecodes::_if_icmpne:
769 case Bytecodes::_if_icmplt:
770 case Bytecodes::_if_icmpge:
771 case Bytecodes::_if_icmpgt:
772 case Bytecodes::_if_icmple:
773 {
774 state.spop();
775 state.spop();
776 int dest_bci = s.get_dest();
777 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
778 assert(s.next_bci() == limit_bci, "branch must end block");
779 successors.push(_methodBlocks->block_containing(dest_bci));
780 break;
781 }
782 case Bytecodes::_if_acmpeq:
783 case Bytecodes::_if_acmpne:
784 {
785 set_method_escape(state.apop());
786 set_method_escape(state.apop());
787 int dest_bci = s.get_dest();
788 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
789 assert(s.next_bci() == limit_bci, "branch must end block");
790 successors.push(_methodBlocks->block_containing(dest_bci));
791 break;
792 }
793 case Bytecodes::_goto:
794 {
795 int dest_bci = s.get_dest();
796 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
797 assert(s.next_bci() == limit_bci, "branch must end block");
798 successors.push(_methodBlocks->block_containing(dest_bci));
799 fall_through = false;
800 break;
801 }
802 case Bytecodes::_jsr:
803 {
804 int dest_bci = s.get_dest();
805 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
806 assert(s.next_bci() == limit_bci, "branch must end block");
807 state.apush(empty_map);
808 successors.push(_methodBlocks->block_containing(dest_bci));
809 fall_through = false;
810 break;
811 }
812 case Bytecodes::_ret:
813 // we don't track the destination of a "ret" instruction
814 assert(s.next_bci() == limit_bci, "branch must end block");
815 fall_through = false;
816 break;
817 case Bytecodes::_return:
818 assert(s.next_bci() == limit_bci, "return must end block");
819 fall_through = false;
820 break;
821 case Bytecodes::_tableswitch:
822 {
823 state.spop();
824 Bytecode_tableswitch sw(&s);
825 int len = sw.length();
826 int dest_bci;
827 for (int i = 0; i < len; i++) {
828 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
829 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
830 successors.push(_methodBlocks->block_containing(dest_bci));
831 }
832 dest_bci = s.cur_bci() + sw.default_offset();
833 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
834 successors.push(_methodBlocks->block_containing(dest_bci));
835 assert(s.next_bci() == limit_bci, "branch must end block");
836 fall_through = false;
837 break;
838 }
839 case Bytecodes::_lookupswitch:
840 {
841 state.spop();
842 Bytecode_lookupswitch sw(&s);
843 int len = sw.number_of_pairs();
844 int dest_bci;
845 for (int i = 0; i < len; i++) {
846 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
847 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
848 successors.push(_methodBlocks->block_containing(dest_bci));
849 }
850 dest_bci = s.cur_bci() + sw.default_offset();
851 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
852 successors.push(_methodBlocks->block_containing(dest_bci));
853 fall_through = false;
854 break;
855 }
856 case Bytecodes::_ireturn:
857 case Bytecodes::_freturn:
858 state.spop();
859 fall_through = false;
860 break;
861 case Bytecodes::_lreturn:
862 case Bytecodes::_dreturn:
863 state.lpop();
864 fall_through = false;
865 break;
866 case Bytecodes::_areturn:
867 case Bytecodes::_vreturn:
868 set_returned(state.apop());
869 fall_through = false;
870 break;
871 case Bytecodes::_getstatic:
872 case Bytecodes::_getfield:
873 { bool ignored_will_link;
874 ciField* field = s.get_field(ignored_will_link);
875 BasicType field_type = field->type()->basic_type();
876 if (s.cur_bc() != Bytecodes::_getstatic) {
877 set_method_escape(state.apop());
878 }
879 if (field_type == T_OBJECT || field_type == T_ARRAY) {
880 state.apush(unknown_obj);
881 } else if (type2size[field_type] == 1) {
882 state.spush();
883 } else {
884 state.lpush();
885 }
886 }
887 break;
888 case Bytecodes::_putstatic:
889 case Bytecodes::_putfield:
890 { bool will_link;
891 ciField* field = s.get_field(will_link);
892 BasicType field_type = field->type()->basic_type();
893 if (field_type == T_OBJECT || field_type == T_ARRAY) {
894 set_global_escape(state.apop());
895 } else if (type2size[field_type] == 1) {
896 state.spop();
897 } else {
898 state.lpop();
899 }
900 if (s.cur_bc() != Bytecodes::_putstatic) {
901 ArgumentMap p = state.apop();
902 set_method_escape(p);
903 set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
904 }
905 }
906 break;
907 case Bytecodes::_invokevirtual:
908 case Bytecodes::_invokespecial:
909 case Bytecodes::_invokestatic:
910 case Bytecodes::_invokedynamic:
911 case Bytecodes::_invokeinterface:
912 { bool ignored_will_link;
913 ciSignature* declared_signature = NULL;
914 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
915 ciKlass* holder = s.get_declared_method_holder();
916 assert(declared_signature != NULL, "cannot be null");
917 // If the current bytecode has an attached appendix argument,
918 // push an unknown object to represent that argument. (Analysis
919 // of dynamic call sites, especially invokehandle calls, needs
920 // the appendix argument on the stack, in addition to "regular" arguments
921 // pushed onto the stack by bytecode instructions preceding the call.)
922 //
923 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
924 // method to determine whether the current bytecode has an appendix argument.
925 // The has_appendix() method obtains the appendix from the
926 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
927 // resolution of dynamic call sites. Callees in the
928 // ciBytecodeStream::get_method() call above also access the _f1 field;
929 // interleaving the get_method() and has_appendix() calls in the current
930 // method with call site resolution can lead to an inconsistent view of
931 // the current method's argument count. In particular, some interleaving(s)
932 // can cause the method's argument count to not include the appendix, which
933 // then leads to stack over-/underflow in the escape analyzer.
934 //
935 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
936 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
937 // instructions, except if the call site is the _invokeBasic intrinsic
938 // (that intrinsic is always targeted by an invokehandle instruction but does
939 // not have an appendix argument).
940 if (target->is_loaded() &&
941 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
942 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
943 state.apush(unknown_obj);
944 }
945 // Pass in raw bytecode because we need to see invokehandle instructions.
946 invoke(state, s.cur_bc_raw(), target, holder);
947 // We are using the return type of the declared signature here because
948 // it might be a more concrete type than the one from the target (for
949 // e.g. invokedynamic and invokehandle).
950 ciType* return_type = declared_signature->return_type();
951 if (!return_type->is_primitive_type()) {
952 state.apush(unknown_obj);
953 } else if (return_type->is_one_word()) {
954 state.spush();
955 } else if (return_type->is_two_word()) {
956 state.lpush();
957 }
958 }
959 break;
960 case Bytecodes::_new:
961 case Bytecodes::_vdefault:
962 state.apush(allocated_obj);
963 break;
964 case Bytecodes::_vwithfield: {
965 bool will_link;
966 ciField* field = s.get_field(will_link);
967 BasicType field_type = field->type()->basic_type();
968 if (field_type == T_OBJECT || field_type == T_ARRAY) {
969 set_global_escape(state.apop());
970 } else if (type2size[field_type] == 1) {
971 state.spop();
972 } else {
973 state.lpop();
974 }
975 set_method_escape(state.apop());
976 state.apush(allocated_obj);
977 break;
978 }
979 case Bytecodes::_newarray:
980 case Bytecodes::_anewarray:
981 state.spop();
982 state.apush(allocated_obj);
983 break;
984 case Bytecodes::_multianewarray:
985 { int i = s.cur_bcp()[3];
986 while (i-- > 0) state.spop();
987 state.apush(allocated_obj);
988 }
989 break;
990 case Bytecodes::_arraylength:
991 set_method_escape(state.apop());
992 state.spush();
993 break;
994 case Bytecodes::_athrow:
995 set_global_escape(state.apop());
996 fall_through = false;
997 break;
998 case Bytecodes::_checkcast:
999 { ArgumentMap obj = state.apop();
1000 set_method_escape(obj);
1001 state.apush(obj);
1002 }
1003 break;
1004 case Bytecodes::_instanceof:
1005 set_method_escape(state.apop());
1006 state.spush();
1007 break;
1008 case Bytecodes::_monitorenter:
1009 case Bytecodes::_monitorexit:
1010 state.apop();
1011 break;
1012 case Bytecodes::_wide:
1013 ShouldNotReachHere();
1014 break;
1015 case Bytecodes::_ifnull:
1016 case Bytecodes::_ifnonnull:
1017 {
1018 set_method_escape(state.apop());
1019 int dest_bci = s.get_dest();
1020 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1021 assert(s.next_bci() == limit_bci, "branch must end block");
1022 successors.push(_methodBlocks->block_containing(dest_bci));
1023 break;
1024 }
1025 case Bytecodes::_goto_w:
1026 {
1027 int dest_bci = s.get_far_dest();
1028 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1029 assert(s.next_bci() == limit_bci, "branch must end block");
1030 successors.push(_methodBlocks->block_containing(dest_bci));
1031 fall_through = false;
1032 break;
1033 }
1034 case Bytecodes::_jsr_w:
1035 {
1036 int dest_bci = s.get_far_dest();
1037 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1038 assert(s.next_bci() == limit_bci, "branch must end block");
1039 state.apush(empty_map);
1040 successors.push(_methodBlocks->block_containing(dest_bci));
1041 fall_through = false;
1042 break;
1043 }
1044 case Bytecodes::_breakpoint:
1045 break;
1046 case Bytecodes::_vbox:
1047 case Bytecodes::_vunbox:
1048 set_method_escape(state.apop());
1049 state.apush(allocated_obj);
1050 break;
1051 default:
1052 ShouldNotReachHere();
1053 break;
1054 }
1055
1056 }
1057 if (fall_through) {
1058 int fall_through_bci = s.cur_bci();
1059 if (fall_through_bci < _method->code_size()) {
1060 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1061 successors.push(_methodBlocks->block_containing(fall_through_bci));
1062 }
1063 }
1064 }
1065
1066 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1067 StateInfo *d_state = blockstates + dest->index();
1068 int nlocals = _method->max_locals();
1069
1070 // exceptions may cause transfer of control to handlers in the middle of a
1071 // block, so we don't merge the incoming state of exception handlers
1072 if (dest->is_handler())
1073 return;
1074 if (!d_state->_initialized ) {
1075 // destination not initialized, just copy
1076 for (int i = 0; i < nlocals; i++) {
1077 d_state->_vars[i] = s_state->_vars[i];
1078 }
1079 for (int i = 0; i < s_state->_stack_height; i++) {
1080 d_state->_stack[i] = s_state->_stack[i];
1081 }
1082 d_state->_stack_height = s_state->_stack_height;
1083 d_state->_max_stack = s_state->_max_stack;
1084 d_state->_initialized = true;
1085 } else if (!dest->processed()) {
1086 // we have not yet walked the bytecodes of dest, we can merge
1087 // the states
1088 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1089 for (int i = 0; i < nlocals; i++) {
1090 d_state->_vars[i].set_union(s_state->_vars[i]);
1091 }
1092 for (int i = 0; i < s_state->_stack_height; i++) {
1093 d_state->_stack[i].set_union(s_state->_stack[i]);
1094 }
1095 } else {
1096 // the bytecodes of dest have already been processed, mark any
1097 // arguments in the source state which are not in the dest state
1098 // as global escape.
1099 // Future refinement: we only need to mark these variable to the
1100 // maximum escape of any variables in dest state
1101 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1102 ArgumentMap extra_vars;
1103 for (int i = 0; i < nlocals; i++) {
1104 ArgumentMap t;
1105 t = s_state->_vars[i];
1106 t.set_difference(d_state->_vars[i]);
1107 extra_vars.set_union(t);
1108 }
1109 for (int i = 0; i < s_state->_stack_height; i++) {
1110 ArgumentMap t;
1111 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1112 t.clear();
1113 t = s_state->_stack[i];
1114 t.set_difference(d_state->_stack[i]);
1115 extra_vars.set_union(t);
1116 }
1117 set_global_escape(extra_vars, true);
1118 }
1119 }
1120
1121 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1122 int numblocks = _methodBlocks->num_blocks();
1123 int stkSize = _method->max_stack();
1124 int numLocals = _method->max_locals();
1125 StateInfo state;
1126
1127 int datacount = (numblocks + 1) * (stkSize + numLocals);
1128 int datasize = datacount * sizeof(ArgumentMap);
1129 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1130 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1131 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1132 ArgumentMap *dp = statedata;
1133 state._vars = dp;
1134 dp += numLocals;
1135 state._stack = dp;
1136 dp += stkSize;
1137 state._initialized = false;
1138 state._max_stack = stkSize;
1139 for (int i = 0; i < numblocks; i++) {
1140 blockstates[i]._vars = dp;
1141 dp += numLocals;
1142 blockstates[i]._stack = dp;
1143 dp += stkSize;
1144 blockstates[i]._initialized = false;
1145 blockstates[i]._stack_height = 0;
1146 blockstates[i]._max_stack = stkSize;
1147 }
1148 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
1149 GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
1150
1151 _methodBlocks->clear_processed();
1152
1153 // initialize block 0 state from method signature
1154 ArgumentMap allVars; // all oop arguments to method
1155 ciSignature* sig = method()->signature();
1156 int j = 0;
1157 ciBlock* first_blk = _methodBlocks->block_containing(0);
1158 int fb_i = first_blk->index();
1159 if (!method()->is_static()) {
1160 // record information for "this"
1161 blockstates[fb_i]._vars[j].set(j);
1162 allVars.add(j);
1163 j++;
1164 }
1165 for (int i = 0; i < sig->count(); i++) {
1166 ciType* t = sig->type_at(i);
1167 if (!t->is_primitive_type()) {
1168 blockstates[fb_i]._vars[j].set(j);
1169 allVars.add(j);
1170 }
1171 j += t->size();
1172 }
1173 blockstates[fb_i]._initialized = true;
1174 assert(j == _arg_size, "just checking");
1175
1176 ArgumentMap unknown_map;
1177 unknown_map.add_unknown();
1178
1179 worklist.push(first_blk);
1180 while(worklist.length() > 0) {
1181 ciBlock *blk = worklist.pop();
1182 StateInfo *blkState = blockstates + blk->index();
1183 if (blk->is_handler() || blk->is_ret_target()) {
1184 // for an exception handler or a target of a ret instruction, we assume the worst case,
1185 // that any variable could contain any argument
1186 for (int i = 0; i < numLocals; i++) {
1187 state._vars[i] = allVars;
1188 }
1189 if (blk->is_handler()) {
1190 state._stack_height = 1;
1191 } else {
1192 state._stack_height = blkState->_stack_height;
1193 }
1194 for (int i = 0; i < state._stack_height; i++) {
1195 // ??? should this be unknown_map ???
1196 state._stack[i] = allVars;
1197 }
1198 } else {
1199 for (int i = 0; i < numLocals; i++) {
1200 state._vars[i] = blkState->_vars[i];
1201 }
1202 for (int i = 0; i < blkState->_stack_height; i++) {
1203 state._stack[i] = blkState->_stack[i];
1204 }
1205 state._stack_height = blkState->_stack_height;
1206 }
1207 iterate_one_block(blk, state, successors);
1208 // if this block has any exception handlers, push them
1209 // onto successor list
1210 if (blk->has_handler()) {
1211 DEBUG_ONLY(int handler_count = 0;)
1212 int blk_start = blk->start_bci();
1213 int blk_end = blk->limit_bci();
1214 for (int i = 0; i < numblocks; i++) {
1215 ciBlock *b = _methodBlocks->block(i);
1216 if (b->is_handler()) {
1217 int ex_start = b->ex_start_bci();
1218 int ex_end = b->ex_limit_bci();
1219 if ((ex_start >= blk_start && ex_start < blk_end) ||
1220 (ex_end > blk_start && ex_end <= blk_end)) {
1221 successors.push(b);
1222 }
1223 DEBUG_ONLY(handler_count++;)
1224 }
1225 }
1226 assert(handler_count > 0, "must find at least one handler");
1227 }
1228 // merge computed variable state with successors
1229 while(successors.length() > 0) {
1230 ciBlock *succ = successors.pop();
1231 merge_block_states(blockstates, succ, &state);
1232 if (!succ->processed())
1233 worklist.push(succ);
1234 }
1235 }
1236 }
1237
1238 bool BCEscapeAnalyzer::do_analysis() {
1239 Arena* arena = CURRENT_ENV->arena();
1240 // identify basic blocks
1241 _methodBlocks = _method->get_method_blocks();
1242
1243 iterate_blocks(arena);
1244 // TEMPORARY
1245 return true;
1246 }
1247
1248 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
1249 vmIntrinsics::ID iid = method()->intrinsic_id();
1250
1251 if (iid == vmIntrinsics::_getClass ||
1252 iid == vmIntrinsics::_hashCode)
1253 return iid;
1254 else
1255 return vmIntrinsics::_none;
1256 }
1257
1258 bool BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
1259 ArgumentMap arg;
1260 arg.clear();
1261 switch (iid) {
1262 case vmIntrinsics::_getClass:
1263 _return_local = false;
1264 break;
1265 case vmIntrinsics::_hashCode:
1266 // initialized state is correct
1267 break;
1268 default:
1269 assert(false, "unexpected intrinsic");
1270 }
1271 return true;
1272 }
1273
1274 void BCEscapeAnalyzer::initialize() {
1275 int i;
1276
1277 // clear escape information (method may have been deoptimized)
1278 methodData()->clear_escape_info();
1279
1280 // initialize escape state of object parameters
1281 ciSignature* sig = method()->signature();
1282 int j = 0;
1283 if (!method()->is_static()) {
1284 _arg_local.set(0);
1285 _arg_stack.set(0);
1286 j++;
1287 }
1288 for (i = 0; i < sig->count(); i++) {
1289 ciType* t = sig->type_at(i);
1290 if (!t->is_primitive_type()) {
1291 _arg_local.set(j);
1292 _arg_stack.set(j);
1293 }
1294 j += t->size();
1295 }
1296 assert(j == _arg_size, "just checking");
1297
1298 // start with optimistic assumption
1299 ciType *rt = _method->return_type();
1300 if (rt->is_primitive_type()) {
1301 _return_local = false;
1302 _return_allocated = false;
1303 } else {
1304 _return_local = true;
1305 _return_allocated = true;
1306 }
1307 _allocated_escapes = false;
1308 _unknown_modified = false;
1309 }
1310
1311 void BCEscapeAnalyzer::clear_escape_info() {
1312 ciSignature* sig = method()->signature();
1313 int arg_count = sig->count();
1314 ArgumentMap var;
1315 if (!method()->is_static()) {
1316 arg_count++; // allow for "this"
1317 }
1318 for (int i = 0; i < arg_count; i++) {
1319 set_arg_modified(i, OFFSET_ANY, 4);
1320 var.clear();
1321 var.set(i);
1322 set_modified(var, OFFSET_ANY, 4);
1323 set_global_escape(var);
1324 }
1325 _arg_local.Clear();
1326 _arg_stack.Clear();
1327 _arg_returned.Clear();
1328 _return_local = false;
1329 _return_allocated = false;
1330 _allocated_escapes = true;
1331 _unknown_modified = true;
1332 }
1333
1334
1335 void BCEscapeAnalyzer::compute_escape_info() {
1336 int i;
1337 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1338
1339 vmIntrinsics::ID iid = known_intrinsic();
1340
1341 // check if method can be analyzed
1342 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1343 || _level > MaxBCEAEstimateLevel
1344 || method()->code_size() > MaxBCEAEstimateSize)) {
1345 if (BCEATraceLevel >= 1) {
1346 tty->print("Skipping method because: ");
1347 if (method()->is_abstract())
1348 tty->print_cr("method is abstract.");
1349 else if (method()->is_native())
1350 tty->print_cr("method is native.");
1351 else if (!method()->holder()->is_initialized())
1352 tty->print_cr("class of method is not initialized.");
1353 else if (_level > MaxBCEAEstimateLevel)
1354 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1355 _level, (int) MaxBCEAEstimateLevel);
1356 else if (method()->code_size() > MaxBCEAEstimateSize)
1357 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1358 method()->code_size(), (int) MaxBCEAEstimateSize);
1359 else
1360 ShouldNotReachHere();
1361 }
1362 clear_escape_info();
1363
1364 return;
1365 }
1366
1367 if (BCEATraceLevel >= 1) {
1368 tty->print("[EA] estimating escape information for");
1369 if (iid != vmIntrinsics::_none)
1370 tty->print(" intrinsic");
1371 method()->print_short_name();
1372 tty->print_cr(" (%d bytes)", method()->code_size());
1373 }
1374
1375 bool success;
1376
1377 initialize();
1378
1379 // Do not scan method if it has no object parameters and
1380 // does not returns an object (_return_allocated is set in initialize()).
1381 if (_arg_local.Size() == 0 && !_return_allocated) {
1382 // Clear all info since method's bytecode was not analysed and
1383 // set pessimistic escape information.
1384 clear_escape_info();
1385 methodData()->set_eflag(MethodData::allocated_escapes);
1386 methodData()->set_eflag(MethodData::unknown_modified);
1387 methodData()->set_eflag(MethodData::estimated);
1388 return;
1389 }
1390
1391 if (iid != vmIntrinsics::_none)
1392 success = compute_escape_for_intrinsic(iid);
1393 else {
1394 success = do_analysis();
1395 }
1396
1397 // don't store interprocedural escape information if it introduces
1398 // dependencies or if method data is empty
1399 //
1400 if (!has_dependencies() && !methodData()->is_empty()) {
1401 for (i = 0; i < _arg_size; i++) {
1402 if (_arg_local.test(i)) {
1403 assert(_arg_stack.test(i), "inconsistent escape info");
1404 methodData()->set_arg_local(i);
1405 methodData()->set_arg_stack(i);
1406 } else if (_arg_stack.test(i)) {
1407 methodData()->set_arg_stack(i);
1408 }
1409 if (_arg_returned.test(i)) {
1410 methodData()->set_arg_returned(i);
1411 }
1412 methodData()->set_arg_modified(i, _arg_modified[i]);
1413 }
1414 if (_return_local) {
1415 methodData()->set_eflag(MethodData::return_local);
1416 }
1417 if (_return_allocated) {
1418 methodData()->set_eflag(MethodData::return_allocated);
1419 }
1420 if (_allocated_escapes) {
1421 methodData()->set_eflag(MethodData::allocated_escapes);
1422 }
1423 if (_unknown_modified) {
1424 methodData()->set_eflag(MethodData::unknown_modified);
1425 }
1426 methodData()->set_eflag(MethodData::estimated);
1427 }
1428 }
1429
1430 void BCEscapeAnalyzer::read_escape_info() {
1431 assert(methodData()->has_escape_info(), "no escape info available");
1432
1433 // read escape information from method descriptor
1434 for (int i = 0; i < _arg_size; i++) {
1435 if (methodData()->is_arg_local(i))
1436 _arg_local.set(i);
1437 if (methodData()->is_arg_stack(i))
1438 _arg_stack.set(i);
1439 if (methodData()->is_arg_returned(i))
1440 _arg_returned.set(i);
1441 _arg_modified[i] = methodData()->arg_modified(i);
1442 }
1443 _return_local = methodData()->eflag_set(MethodData::return_local);
1444 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1445 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1446 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1447
1448 }
1449
1450 #ifndef PRODUCT
1451 void BCEscapeAnalyzer::dump() {
1452 tty->print("[EA] estimated escape information for");
1453 method()->print_short_name();
1454 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1455 tty->print(" non-escaping args: ");
1456 _arg_local.print();
1457 tty->print(" stack-allocatable args: ");
1458 _arg_stack.print();
1459 if (_return_local) {
1460 tty->print(" returned args: ");
1461 _arg_returned.print();
1462 } else if (is_return_allocated()) {
1463 tty->print_cr(" return allocated value");
1464 } else {
1465 tty->print_cr(" return non-local value");
1466 }
1467 tty->print(" modified args: ");
1468 for (int i = 0; i < _arg_size; i++) {
1469 if (_arg_modified[i] == 0)
1470 tty->print(" 0");
1471 else
1472 tty->print(" 0x%x", _arg_modified[i]);
1473 }
1474 tty->cr();
1475 tty->print(" flags: ");
1476 if (_return_allocated)
1477 tty->print(" return_allocated");
1478 if (_allocated_escapes)
1479 tty->print(" allocated_escapes");
1480 if (_unknown_modified)
1481 tty->print(" unknown_modified");
1482 tty->cr();
1483 }
1484 #endif
1485
1486 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1487 : _conservative(method == NULL || !EstimateArgEscape)
1488 , _arena(CURRENT_ENV->arena())
1489 , _method(method)
1490 , _methodData(method ? method->method_data() : NULL)
1491 , _arg_size(method ? method->arg_size() : 0)
1492 , _arg_local(_arena)
1493 , _arg_stack(_arena)
1494 , _arg_returned(_arena)
1495 , _dirty(_arena)
1496 , _return_local(false)
1497 , _return_allocated(false)
1498 , _allocated_escapes(false)
1499 , _unknown_modified(false)
1500 , _dependencies(_arena, 4, 0, NULL)
1501 , _parent(parent)
1502 , _level(parent == NULL ? 0 : parent->level() + 1) {
1503 if (!_conservative) {
1504 _arg_local.Clear();
1505 _arg_stack.Clear();
1506 _arg_returned.Clear();
1507 _dirty.Clear();
1508 Arena* arena = CURRENT_ENV->arena();
1509 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1510 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1511
1512 if (methodData() == NULL)
1513 return;
1514 if (methodData()->has_escape_info()) {
1515 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1516 method->holder()->name()->as_utf8(),
1517 method->name()->as_utf8()));
1518 read_escape_info();
1519 } else {
1520 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1521 method->holder()->name()->as_utf8(),
1522 method->name()->as_utf8()));
1523
1524 compute_escape_info();
1525 methodData()->update_escape_info();
1526 }
1527 #ifndef PRODUCT
1528 if (BCEATraceLevel >= 3) {
1529 // dump escape information
1530 dump();
1531 }
1532 #endif
1533 }
1534 }
1535
1536 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1537 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1538 // Also record evol dependencies so redefinition of the
1539 // callee will trigger recompilation.
1540 deps->assert_evol_method(method());
1541 }
1542 for (int i = 0; i < _dependencies.length(); i+=2) {
1543 ciKlass *k = _dependencies.at(i)->as_klass();
1544 ciMethod *m = _dependencies.at(i+1)->as_method();
1545 deps->assert_unique_concrete_method(k, m);
1546 }
1547 }