1 /*
2 * Copyright (c) 2005, 2015, 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 }
270 }
271
272 // compute size of arguments
273 int arg_size = target->invoke_arg_size(code);
274 int arg_base = MAX2(state._stack_height - arg_size, 0);
275
276 // direct recursive calls are skipped if they can be bound statically without introducing
277 // dependencies and if parameters are passed at the same position as in the current method
278 // other calls are skipped if there are no unescaped arguments passed to them
279 bool directly_recursive = (method() == target) &&
280 (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
281
282 // check if analysis of callee can safely be skipped
283 bool skip_callee = true;
284 for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
285 ArgumentMap arg = state._stack[i];
286 skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
287 }
288 // For now we conservatively skip invokedynamic.
289 if (code == Bytecodes::_invokedynamic) {
290 skip_callee = true;
291 }
292 if (skip_callee) {
293 TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
294 for (i = 0; i < arg_size; i++) {
295 set_method_escape(state.raw_pop());
296 }
297 _unknown_modified = true; // assume the worst since we don't analyze the called method
298 return;
299 }
300
301 // determine actual method (use CHA if necessary)
302 ciMethod* inline_target = NULL;
303 if (target->is_loaded() && klass->is_loaded()
304 && (klass->is_initialized() || klass->is_interface() && target->holder()->is_initialized())
305 && target->is_loaded()) {
306 if (code == Bytecodes::_invokestatic
307 || code == Bytecodes::_invokespecial
308 || code == Bytecodes::_invokevirtual && target->is_final_method()) {
309 inline_target = target;
310 } else {
311 inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
312 }
313 }
314
315 if (inline_target != NULL && !is_recursive_call(inline_target)) {
316 // analyze callee
317 BCEscapeAnalyzer analyzer(inline_target, this);
318
319 // adjust escape state of actual parameters
320 bool must_record_dependencies = false;
321 for (i = arg_size - 1; i >= 0; i--) {
322 ArgumentMap arg = state.raw_pop();
323 // Check if callee arg is a caller arg or an allocated object
324 bool allocated = arg.contains_allocated();
325 if (!(is_argument(arg) || allocated))
326 continue;
327 for (int j = 0; j < _arg_size; j++) {
328 if (arg.contains(j)) {
329 _arg_modified[j] |= analyzer._arg_modified[i];
330 }
331 }
332 if (!(is_arg_stack(arg) || allocated)) {
333 // arguments have already been recognized as escaping
334 } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
335 set_method_escape(arg);
336 must_record_dependencies = true;
337 } else {
338 set_global_escape(arg);
339 }
340 }
341 _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
342
343 // record dependencies if at least one parameter retained stack-allocatable
344 if (must_record_dependencies) {
345 if (code == Bytecodes::_invokeinterface || code == Bytecodes::_invokevirtual && !target->is_final_method()) {
346 _dependencies.append(actual_recv);
347 _dependencies.append(inline_target);
348 }
349 _dependencies.appendAll(analyzer.dependencies());
350 }
351 } else {
352 TRACE_BCEA(1, tty->print_cr("[EA] virtual method %s is not monomorphic.",
353 target->name()->as_utf8()));
354 // conservatively mark all actual parameters as escaping globally
355 for (i = 0; i < arg_size; i++) {
356 ArgumentMap arg = state.raw_pop();
357 if (!is_argument(arg))
358 continue;
359 set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
360 set_global_escape(arg);
361 }
362 _unknown_modified = true; // assume the worst since we don't know the called method
363 }
364 }
365
366 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
367 return ((~arg_set1) | arg_set2) == 0;
368 }
369
370
371 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
372
373 blk->set_processed();
374 ciBytecodeStream s(method());
375 int limit_bci = blk->limit_bci();
376 bool fall_through = false;
377 ArgumentMap allocated_obj;
378 allocated_obj.add_allocated();
379 ArgumentMap unknown_obj;
380 unknown_obj.add_unknown();
381 ArgumentMap empty_map;
382
383 s.reset_to_bci(blk->start_bci());
384 while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
385 fall_through = true;
386 switch (s.cur_bc()) {
387 case Bytecodes::_nop:
388 break;
389 case Bytecodes::_aconst_null:
390 state.apush(unknown_obj);
391 break;
392 case Bytecodes::_iconst_m1:
393 case Bytecodes::_iconst_0:
394 case Bytecodes::_iconst_1:
395 case Bytecodes::_iconst_2:
396 case Bytecodes::_iconst_3:
397 case Bytecodes::_iconst_4:
398 case Bytecodes::_iconst_5:
399 case Bytecodes::_fconst_0:
400 case Bytecodes::_fconst_1:
401 case Bytecodes::_fconst_2:
402 case Bytecodes::_bipush:
403 case Bytecodes::_sipush:
404 state.spush();
405 break;
406 case Bytecodes::_lconst_0:
407 case Bytecodes::_lconst_1:
408 case Bytecodes::_dconst_0:
409 case Bytecodes::_dconst_1:
410 state.lpush();
411 break;
412 case Bytecodes::_ldc:
413 case Bytecodes::_ldc_w:
414 case Bytecodes::_ldc2_w:
415 {
416 // Avoid calling get_constant() which will try to allocate
417 // unloaded constant. We need only constant's type.
418 int index = s.get_constant_pool_index();
419 constantTag tag = s.get_constant_pool_tag(index);
420 if (tag.is_long() || tag.is_double()) {
421 // Only longs and doubles use 2 stack slots.
422 state.lpush();
423 } else if (tag.basic_type() == T_OBJECT) {
424 state.apush(unknown_obj);
425 } else {
426 state.spush();
427 }
428 break;
429 }
430 case Bytecodes::_aload:
431 state.apush(state._vars[s.get_index()]);
432 break;
433 case Bytecodes::_iload:
434 case Bytecodes::_fload:
435 case Bytecodes::_iload_0:
436 case Bytecodes::_iload_1:
437 case Bytecodes::_iload_2:
438 case Bytecodes::_iload_3:
439 case Bytecodes::_fload_0:
440 case Bytecodes::_fload_1:
441 case Bytecodes::_fload_2:
442 case Bytecodes::_fload_3:
443 state.spush();
444 break;
445 case Bytecodes::_lload:
446 case Bytecodes::_dload:
447 case Bytecodes::_lload_0:
448 case Bytecodes::_lload_1:
449 case Bytecodes::_lload_2:
450 case Bytecodes::_lload_3:
451 case Bytecodes::_dload_0:
452 case Bytecodes::_dload_1:
453 case Bytecodes::_dload_2:
454 case Bytecodes::_dload_3:
455 state.lpush();
456 break;
457 case Bytecodes::_aload_0:
458 state.apush(state._vars[0]);
459 break;
460 case Bytecodes::_aload_1:
461 state.apush(state._vars[1]);
462 break;
463 case Bytecodes::_aload_2:
464 state.apush(state._vars[2]);
465 break;
466 case Bytecodes::_aload_3:
467 state.apush(state._vars[3]);
468 break;
469 case Bytecodes::_iaload:
470 case Bytecodes::_faload:
471 case Bytecodes::_baload:
472 case Bytecodes::_caload:
473 case Bytecodes::_saload:
474 state.spop();
475 set_method_escape(state.apop());
476 state.spush();
477 break;
478 case Bytecodes::_laload:
479 case Bytecodes::_daload:
480 state.spop();
481 set_method_escape(state.apop());
482 state.lpush();
483 break;
484 case Bytecodes::_aaload:
485 { state.spop();
486 ArgumentMap array = state.apop();
487 set_method_escape(array);
488 state.apush(unknown_obj);
489 set_dirty(array);
490 }
491 break;
492 case Bytecodes::_istore:
493 case Bytecodes::_fstore:
494 case Bytecodes::_istore_0:
495 case Bytecodes::_istore_1:
496 case Bytecodes::_istore_2:
497 case Bytecodes::_istore_3:
498 case Bytecodes::_fstore_0:
499 case Bytecodes::_fstore_1:
500 case Bytecodes::_fstore_2:
501 case Bytecodes::_fstore_3:
502 state.spop();
503 break;
504 case Bytecodes::_lstore:
505 case Bytecodes::_dstore:
506 case Bytecodes::_lstore_0:
507 case Bytecodes::_lstore_1:
508 case Bytecodes::_lstore_2:
509 case Bytecodes::_lstore_3:
510 case Bytecodes::_dstore_0:
511 case Bytecodes::_dstore_1:
512 case Bytecodes::_dstore_2:
513 case Bytecodes::_dstore_3:
514 state.lpop();
515 break;
516 case Bytecodes::_astore:
517 state._vars[s.get_index()] = state.apop();
518 break;
519 case Bytecodes::_astore_0:
520 state._vars[0] = state.apop();
521 break;
522 case Bytecodes::_astore_1:
523 state._vars[1] = state.apop();
524 break;
525 case Bytecodes::_astore_2:
526 state._vars[2] = state.apop();
527 break;
528 case Bytecodes::_astore_3:
529 state._vars[3] = state.apop();
530 break;
531 case Bytecodes::_iastore:
532 case Bytecodes::_fastore:
533 case Bytecodes::_bastore:
534 case Bytecodes::_castore:
535 case Bytecodes::_sastore:
536 {
537 state.spop();
538 state.spop();
539 ArgumentMap arr = state.apop();
540 set_method_escape(arr);
541 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
542 break;
543 }
544 case Bytecodes::_lastore:
545 case Bytecodes::_dastore:
546 {
547 state.lpop();
548 state.spop();
549 ArgumentMap arr = state.apop();
550 set_method_escape(arr);
551 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
552 break;
553 }
554 case Bytecodes::_aastore:
555 {
556 set_global_escape(state.apop());
557 state.spop();
558 ArgumentMap arr = state.apop();
559 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
560 break;
561 }
562 case Bytecodes::_pop:
563 state.raw_pop();
564 break;
565 case Bytecodes::_pop2:
566 state.raw_pop();
567 state.raw_pop();
568 break;
569 case Bytecodes::_dup:
570 { ArgumentMap w1 = state.raw_pop();
571 state.raw_push(w1);
572 state.raw_push(w1);
573 }
574 break;
575 case Bytecodes::_dup_x1:
576 { ArgumentMap w1 = state.raw_pop();
577 ArgumentMap w2 = state.raw_pop();
578 state.raw_push(w1);
579 state.raw_push(w2);
580 state.raw_push(w1);
581 }
582 break;
583 case Bytecodes::_dup_x2:
584 { ArgumentMap w1 = state.raw_pop();
585 ArgumentMap w2 = state.raw_pop();
586 ArgumentMap w3 = state.raw_pop();
587 state.raw_push(w1);
588 state.raw_push(w3);
589 state.raw_push(w2);
590 state.raw_push(w1);
591 }
592 break;
593 case Bytecodes::_dup2:
594 { ArgumentMap w1 = state.raw_pop();
595 ArgumentMap w2 = state.raw_pop();
596 state.raw_push(w2);
597 state.raw_push(w1);
598 state.raw_push(w2);
599 state.raw_push(w1);
600 }
601 break;
602 case Bytecodes::_dup2_x1:
603 { ArgumentMap w1 = state.raw_pop();
604 ArgumentMap w2 = state.raw_pop();
605 ArgumentMap w3 = state.raw_pop();
606 state.raw_push(w2);
607 state.raw_push(w1);
608 state.raw_push(w3);
609 state.raw_push(w2);
610 state.raw_push(w1);
611 }
612 break;
613 case Bytecodes::_dup2_x2:
614 { ArgumentMap w1 = state.raw_pop();
615 ArgumentMap w2 = state.raw_pop();
616 ArgumentMap w3 = state.raw_pop();
617 ArgumentMap w4 = state.raw_pop();
618 state.raw_push(w2);
619 state.raw_push(w1);
620 state.raw_push(w4);
621 state.raw_push(w3);
622 state.raw_push(w2);
623 state.raw_push(w1);
624 }
625 break;
626 case Bytecodes::_swap:
627 { ArgumentMap w1 = state.raw_pop();
628 ArgumentMap w2 = state.raw_pop();
629 state.raw_push(w1);
630 state.raw_push(w2);
631 }
632 break;
633 case Bytecodes::_iadd:
634 case Bytecodes::_fadd:
635 case Bytecodes::_isub:
636 case Bytecodes::_fsub:
637 case Bytecodes::_imul:
638 case Bytecodes::_fmul:
639 case Bytecodes::_idiv:
640 case Bytecodes::_fdiv:
641 case Bytecodes::_irem:
642 case Bytecodes::_frem:
643 case Bytecodes::_iand:
644 case Bytecodes::_ior:
645 case Bytecodes::_ixor:
646 state.spop();
647 state.spop();
648 state.spush();
649 break;
650 case Bytecodes::_ladd:
651 case Bytecodes::_dadd:
652 case Bytecodes::_lsub:
653 case Bytecodes::_dsub:
654 case Bytecodes::_lmul:
655 case Bytecodes::_dmul:
656 case Bytecodes::_ldiv:
657 case Bytecodes::_ddiv:
658 case Bytecodes::_lrem:
659 case Bytecodes::_drem:
660 case Bytecodes::_land:
661 case Bytecodes::_lor:
662 case Bytecodes::_lxor:
663 state.lpop();
664 state.lpop();
665 state.lpush();
666 break;
667 case Bytecodes::_ishl:
668 case Bytecodes::_ishr:
669 case Bytecodes::_iushr:
670 state.spop();
671 state.spop();
672 state.spush();
673 break;
674 case Bytecodes::_lshl:
675 case Bytecodes::_lshr:
676 case Bytecodes::_lushr:
677 state.spop();
678 state.lpop();
679 state.lpush();
680 break;
681 case Bytecodes::_ineg:
682 case Bytecodes::_fneg:
683 state.spop();
684 state.spush();
685 break;
686 case Bytecodes::_lneg:
687 case Bytecodes::_dneg:
688 state.lpop();
689 state.lpush();
690 break;
691 case Bytecodes::_iinc:
692 break;
693 case Bytecodes::_i2l:
694 case Bytecodes::_i2d:
695 case Bytecodes::_f2l:
696 case Bytecodes::_f2d:
697 state.spop();
698 state.lpush();
699 break;
700 case Bytecodes::_i2f:
701 case Bytecodes::_f2i:
702 state.spop();
703 state.spush();
704 break;
705 case Bytecodes::_l2i:
706 case Bytecodes::_l2f:
707 case Bytecodes::_d2i:
708 case Bytecodes::_d2f:
709 state.lpop();
710 state.spush();
711 break;
712 case Bytecodes::_l2d:
713 case Bytecodes::_d2l:
714 state.lpop();
715 state.lpush();
716 break;
717 case Bytecodes::_i2b:
718 case Bytecodes::_i2c:
719 case Bytecodes::_i2s:
720 state.spop();
721 state.spush();
722 break;
723 case Bytecodes::_lcmp:
724 case Bytecodes::_dcmpl:
725 case Bytecodes::_dcmpg:
726 state.lpop();
727 state.lpop();
728 state.spush();
729 break;
730 case Bytecodes::_fcmpl:
731 case Bytecodes::_fcmpg:
732 state.spop();
733 state.spop();
734 state.spush();
735 break;
736 case Bytecodes::_ifeq:
737 case Bytecodes::_ifne:
738 case Bytecodes::_iflt:
739 case Bytecodes::_ifge:
740 case Bytecodes::_ifgt:
741 case Bytecodes::_ifle:
742 {
743 state.spop();
744 int dest_bci = s.get_dest();
745 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
746 assert(s.next_bci() == limit_bci, "branch must end block");
747 successors.push(_methodBlocks->block_containing(dest_bci));
748 break;
749 }
750 case Bytecodes::_if_icmpeq:
751 case Bytecodes::_if_icmpne:
752 case Bytecodes::_if_icmplt:
753 case Bytecodes::_if_icmpge:
754 case Bytecodes::_if_icmpgt:
755 case Bytecodes::_if_icmple:
756 {
757 state.spop();
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_acmpeq:
766 case Bytecodes::_if_acmpne:
767 {
768 set_method_escape(state.apop());
769 set_method_escape(state.apop());
770 int dest_bci = s.get_dest();
771 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
772 assert(s.next_bci() == limit_bci, "branch must end block");
773 successors.push(_methodBlocks->block_containing(dest_bci));
774 break;
775 }
776 case Bytecodes::_goto:
777 {
778 int dest_bci = s.get_dest();
779 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
780 assert(s.next_bci() == limit_bci, "branch must end block");
781 successors.push(_methodBlocks->block_containing(dest_bci));
782 fall_through = false;
783 break;
784 }
785 case Bytecodes::_jsr:
786 {
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 state.apush(empty_map);
791 successors.push(_methodBlocks->block_containing(dest_bci));
792 fall_through = false;
793 break;
794 }
795 case Bytecodes::_ret:
796 // we don't track the destination of a "ret" instruction
797 assert(s.next_bci() == limit_bci, "branch must end block");
798 fall_through = false;
799 break;
800 case Bytecodes::_return:
801 assert(s.next_bci() == limit_bci, "return must end block");
802 fall_through = false;
803 break;
804 case Bytecodes::_tableswitch:
805 {
806 state.spop();
807 Bytecode_tableswitch sw(&s);
808 int len = sw.length();
809 int dest_bci;
810 for (int i = 0; i < len; i++) {
811 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
812 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
813 successors.push(_methodBlocks->block_containing(dest_bci));
814 }
815 dest_bci = s.cur_bci() + sw.default_offset();
816 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
817 successors.push(_methodBlocks->block_containing(dest_bci));
818 assert(s.next_bci() == limit_bci, "branch must end block");
819 fall_through = false;
820 break;
821 }
822 case Bytecodes::_lookupswitch:
823 {
824 state.spop();
825 Bytecode_lookupswitch sw(&s);
826 int len = sw.number_of_pairs();
827 int dest_bci;
828 for (int i = 0; i < len; i++) {
829 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
830 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
831 successors.push(_methodBlocks->block_containing(dest_bci));
832 }
833 dest_bci = s.cur_bci() + sw.default_offset();
834 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
835 successors.push(_methodBlocks->block_containing(dest_bci));
836 fall_through = false;
837 break;
838 }
839 case Bytecodes::_ireturn:
840 case Bytecodes::_freturn:
841 state.spop();
842 fall_through = false;
843 break;
844 case Bytecodes::_lreturn:
845 case Bytecodes::_dreturn:
846 state.lpop();
847 fall_through = false;
848 break;
849 case Bytecodes::_areturn:
850 set_returned(state.apop());
851 fall_through = false;
852 break;
853 case Bytecodes::_getstatic:
854 case Bytecodes::_getfield:
855 { bool ignored_will_link;
856 ciField* field = s.get_field(ignored_will_link);
857 BasicType field_type = field->type()->basic_type();
858 if (s.cur_bc() != Bytecodes::_getstatic) {
859 set_method_escape(state.apop());
860 }
861 if (field_type == T_OBJECT || field_type == T_ARRAY) {
862 state.apush(unknown_obj);
863 } else if (type2size[field_type] == 1) {
864 state.spush();
865 } else {
866 state.lpush();
867 }
868 }
869 break;
870 case Bytecodes::_putstatic:
871 case Bytecodes::_putfield:
872 { bool will_link;
873 ciField* field = s.get_field(will_link);
874 BasicType field_type = field->type()->basic_type();
875 if (field_type == T_OBJECT || field_type == T_ARRAY) {
876 set_global_escape(state.apop());
877 } else if (type2size[field_type] == 1) {
878 state.spop();
879 } else {
880 state.lpop();
881 }
882 if (s.cur_bc() != Bytecodes::_putstatic) {
883 ArgumentMap p = state.apop();
884 set_method_escape(p);
885 set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
886 }
887 }
888 break;
889 case Bytecodes::_invokevirtual:
890 case Bytecodes::_invokespecial:
891 case Bytecodes::_invokestatic:
892 case Bytecodes::_invokedynamic:
893 case Bytecodes::_invokeinterface:
894 { bool ignored_will_link;
895 ciSignature* declared_signature = NULL;
896 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
897 ciKlass* holder = s.get_declared_method_holder();
898 assert(declared_signature != NULL, "cannot be null");
899 // If the current bytecode has an attached appendix argument,
900 // push an unknown object to represent that argument. (Analysis
901 // of dynamic call sites, especially invokehandle calls, needs
902 // the appendix argument on the stack, in addition to "regular" arguments
903 // pushed onto the stack by bytecode instructions preceding the call.)
904 //
905 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
906 // method to determine whether the current bytecode has an appendix argument.
907 // The has_appendix() method obtains the appendix from the
908 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
909 // resolution of dynamic call sites. Callees in the
910 // ciBytecodeStream::get_method() call above also access the _f1 field;
911 // interleaving the get_method() and has_appendix() calls in the current
912 // method with call site resolution can lead to an inconsistent view of
913 // the current method's argument count. In particular, some interleaving(s)
914 // can cause the method's argument count to not include the appendix, which
915 // then leads to stack over-/underflow in the escape analyzer.
916 //
917 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
918 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
919 // instructions, except if the call site is the _invokeBasic intrinsic
920 // (that intrinsic is always targeted by an invokehandle instruction but does
921 // not have an appendix argument).
922 if (target->is_loaded() &&
923 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
924 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
925 state.apush(unknown_obj);
926 }
927 // Pass in raw bytecode because we need to see invokehandle instructions.
928 invoke(state, s.cur_bc_raw(), target, holder);
929 // We are using the return type of the declared signature here because
930 // it might be a more concrete type than the one from the target (for
931 // e.g. invokedynamic and invokehandle).
932 ciType* return_type = declared_signature->return_type();
933 if (!return_type->is_primitive_type()) {
934 state.apush(unknown_obj);
935 } else if (return_type->is_one_word()) {
936 state.spush();
937 } else if (return_type->is_two_word()) {
938 state.lpush();
939 }
940 }
941 break;
942 case Bytecodes::_new:
943 state.apush(allocated_obj);
944 break;
945 case Bytecodes::_newarray:
946 case Bytecodes::_anewarray:
947 state.spop();
948 state.apush(allocated_obj);
949 break;
950 case Bytecodes::_multianewarray:
951 { int i = s.cur_bcp()[3];
952 while (i-- > 0) state.spop();
953 state.apush(allocated_obj);
954 }
955 break;
956 case Bytecodes::_arraylength:
957 set_method_escape(state.apop());
958 state.spush();
959 break;
960 case Bytecodes::_athrow:
961 set_global_escape(state.apop());
962 fall_through = false;
963 break;
964 case Bytecodes::_checkcast:
965 { ArgumentMap obj = state.apop();
966 set_method_escape(obj);
967 state.apush(obj);
968 }
969 break;
970 case Bytecodes::_instanceof:
971 set_method_escape(state.apop());
972 state.spush();
973 break;
974 case Bytecodes::_monitorenter:
975 case Bytecodes::_monitorexit:
976 state.apop();
977 break;
978 case Bytecodes::_wide:
979 ShouldNotReachHere();
980 break;
981 case Bytecodes::_ifnull:
982 case Bytecodes::_ifnonnull:
983 {
984 set_method_escape(state.apop());
985 int dest_bci = s.get_dest();
986 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
987 assert(s.next_bci() == limit_bci, "branch must end block");
988 successors.push(_methodBlocks->block_containing(dest_bci));
989 break;
990 }
991 case Bytecodes::_goto_w:
992 {
993 int dest_bci = s.get_far_dest();
994 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
995 assert(s.next_bci() == limit_bci, "branch must end block");
996 successors.push(_methodBlocks->block_containing(dest_bci));
997 fall_through = false;
998 break;
999 }
1000 case Bytecodes::_jsr_w:
1001 {
1002 int dest_bci = s.get_far_dest();
1003 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1004 assert(s.next_bci() == limit_bci, "branch must end block");
1005 state.apush(empty_map);
1006 successors.push(_methodBlocks->block_containing(dest_bci));
1007 fall_through = false;
1008 break;
1009 }
1010 case Bytecodes::_breakpoint:
1011 break;
1012 default:
1013 ShouldNotReachHere();
1014 break;
1015 }
1016
1017 }
1018 if (fall_through) {
1019 int fall_through_bci = s.cur_bci();
1020 if (fall_through_bci < _method->code_size()) {
1021 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1022 successors.push(_methodBlocks->block_containing(fall_through_bci));
1023 }
1024 }
1025 }
1026
1027 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1028 StateInfo *d_state = blockstates + dest->index();
1029 int nlocals = _method->max_locals();
1030
1031 // exceptions may cause transfer of control to handlers in the middle of a
1032 // block, so we don't merge the incoming state of exception handlers
1033 if (dest->is_handler())
1034 return;
1035 if (!d_state->_initialized ) {
1036 // destination not initialized, just copy
1037 for (int i = 0; i < nlocals; i++) {
1038 d_state->_vars[i] = s_state->_vars[i];
1039 }
1040 for (int i = 0; i < s_state->_stack_height; i++) {
1041 d_state->_stack[i] = s_state->_stack[i];
1042 }
1043 d_state->_stack_height = s_state->_stack_height;
1044 d_state->_max_stack = s_state->_max_stack;
1045 d_state->_initialized = true;
1046 } else if (!dest->processed()) {
1047 // we have not yet walked the bytecodes of dest, we can merge
1048 // the states
1049 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1050 for (int i = 0; i < nlocals; i++) {
1051 d_state->_vars[i].set_union(s_state->_vars[i]);
1052 }
1053 for (int i = 0; i < s_state->_stack_height; i++) {
1054 d_state->_stack[i].set_union(s_state->_stack[i]);
1055 }
1056 } else {
1057 // the bytecodes of dest have already been processed, mark any
1058 // arguments in the source state which are not in the dest state
1059 // as global escape.
1060 // Future refinement: we only need to mark these variable to the
1061 // maximum escape of any variables in dest state
1062 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1063 ArgumentMap extra_vars;
1064 for (int i = 0; i < nlocals; i++) {
1065 ArgumentMap t;
1066 t = s_state->_vars[i];
1067 t.set_difference(d_state->_vars[i]);
1068 extra_vars.set_union(t);
1069 }
1070 for (int i = 0; i < s_state->_stack_height; i++) {
1071 ArgumentMap t;
1072 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1073 t.clear();
1074 t = s_state->_stack[i];
1075 t.set_difference(d_state->_stack[i]);
1076 extra_vars.set_union(t);
1077 }
1078 set_global_escape(extra_vars, true);
1079 }
1080 }
1081
1082 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1083 int numblocks = _methodBlocks->num_blocks();
1084 int stkSize = _method->max_stack();
1085 int numLocals = _method->max_locals();
1086 StateInfo state;
1087
1088 int datacount = (numblocks + 1) * (stkSize + numLocals);
1089 int datasize = datacount * sizeof(ArgumentMap);
1090 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1091 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1092 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1093 ArgumentMap *dp = statedata;
1094 state._vars = dp;
1095 dp += numLocals;
1096 state._stack = dp;
1097 dp += stkSize;
1098 state._initialized = false;
1099 state._max_stack = stkSize;
1100 for (int i = 0; i < numblocks; i++) {
1101 blockstates[i]._vars = dp;
1102 dp += numLocals;
1103 blockstates[i]._stack = dp;
1104 dp += stkSize;
1105 blockstates[i]._initialized = false;
1106 blockstates[i]._stack_height = 0;
1107 blockstates[i]._max_stack = stkSize;
1108 }
1109 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
1110 GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
1111
1112 _methodBlocks->clear_processed();
1113
1114 // initialize block 0 state from method signature
1115 ArgumentMap allVars; // all oop arguments to method
1116 ciSignature* sig = method()->signature();
1117 int j = 0;
1118 ciBlock* first_blk = _methodBlocks->block_containing(0);
1119 int fb_i = first_blk->index();
1120 if (!method()->is_static()) {
1121 // record information for "this"
1122 blockstates[fb_i]._vars[j].set(j);
1123 allVars.add(j);
1124 j++;
1125 }
1126 for (int i = 0; i < sig->count(); i++) {
1127 ciType* t = sig->type_at(i);
1128 if (!t->is_primitive_type()) {
1129 blockstates[fb_i]._vars[j].set(j);
1130 allVars.add(j);
1131 }
1132 j += t->size();
1133 }
1134 blockstates[fb_i]._initialized = true;
1135 assert(j == _arg_size, "just checking");
1136
1137 ArgumentMap unknown_map;
1138 unknown_map.add_unknown();
1139
1140 worklist.push(first_blk);
1141 while(worklist.length() > 0) {
1142 ciBlock *blk = worklist.pop();
1143 StateInfo *blkState = blockstates + blk->index();
1144 if (blk->is_handler() || blk->is_ret_target()) {
1145 // for an exception handler or a target of a ret instruction, we assume the worst case,
1146 // that any variable could contain any argument
1147 for (int i = 0; i < numLocals; i++) {
1148 state._vars[i] = allVars;
1149 }
1150 if (blk->is_handler()) {
1151 state._stack_height = 1;
1152 } else {
1153 state._stack_height = blkState->_stack_height;
1154 }
1155 for (int i = 0; i < state._stack_height; i++) {
1156 // ??? should this be unknown_map ???
1157 state._stack[i] = allVars;
1158 }
1159 } else {
1160 for (int i = 0; i < numLocals; i++) {
1161 state._vars[i] = blkState->_vars[i];
1162 }
1163 for (int i = 0; i < blkState->_stack_height; i++) {
1164 state._stack[i] = blkState->_stack[i];
1165 }
1166 state._stack_height = blkState->_stack_height;
1167 }
1168 iterate_one_block(blk, state, successors);
1169 // if this block has any exception handlers, push them
1170 // onto successor list
1171 if (blk->has_handler()) {
1172 DEBUG_ONLY(int handler_count = 0;)
1173 int blk_start = blk->start_bci();
1174 int blk_end = blk->limit_bci();
1175 for (int i = 0; i < numblocks; i++) {
1176 ciBlock *b = _methodBlocks->block(i);
1177 if (b->is_handler()) {
1178 int ex_start = b->ex_start_bci();
1179 int ex_end = b->ex_limit_bci();
1180 if ((ex_start >= blk_start && ex_start < blk_end) ||
1181 (ex_end > blk_start && ex_end <= blk_end)) {
1182 successors.push(b);
1183 }
1184 DEBUG_ONLY(handler_count++;)
1185 }
1186 }
1187 assert(handler_count > 0, "must find at least one handler");
1188 }
1189 // merge computed variable state with successors
1190 while(successors.length() > 0) {
1191 ciBlock *succ = successors.pop();
1192 merge_block_states(blockstates, succ, &state);
1193 if (!succ->processed())
1194 worklist.push(succ);
1195 }
1196 }
1197 }
1198
1199 bool BCEscapeAnalyzer::do_analysis() {
1200 Arena* arena = CURRENT_ENV->arena();
1201 // identify basic blocks
1202 _methodBlocks = _method->get_method_blocks();
1203
1204 iterate_blocks(arena);
1205 // TEMPORARY
1206 return true;
1207 }
1208
1209 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
1210 vmIntrinsics::ID iid = method()->intrinsic_id();
1211
1212 if (iid == vmIntrinsics::_getClass ||
1213 iid == vmIntrinsics::_hashCode)
1214 return iid;
1215 else
1216 return vmIntrinsics::_none;
1217 }
1218
1219 bool BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
1220 ArgumentMap arg;
1221 arg.clear();
1222 switch (iid) {
1223 case vmIntrinsics::_getClass:
1224 _return_local = false;
1225 break;
1226 case vmIntrinsics::_hashCode:
1227 // initialized state is correct
1228 break;
1229 default:
1230 assert(false, "unexpected intrinsic");
1231 }
1232 return true;
1233 }
1234
1235 void BCEscapeAnalyzer::initialize() {
1236 int i;
1237
1238 // clear escape information (method may have been deoptimized)
1239 methodData()->clear_escape_info();
1240
1241 // initialize escape state of object parameters
1242 ciSignature* sig = method()->signature();
1243 int j = 0;
1244 if (!method()->is_static()) {
1245 _arg_local.set(0);
1246 _arg_stack.set(0);
1247 j++;
1248 }
1249 for (i = 0; i < sig->count(); i++) {
1250 ciType* t = sig->type_at(i);
1251 if (!t->is_primitive_type()) {
1252 _arg_local.set(j);
1253 _arg_stack.set(j);
1254 }
1255 j += t->size();
1256 }
1257 assert(j == _arg_size, "just checking");
1258
1259 // start with optimistic assumption
1260 ciType *rt = _method->return_type();
1261 if (rt->is_primitive_type()) {
1262 _return_local = false;
1263 _return_allocated = false;
1264 } else {
1265 _return_local = true;
1266 _return_allocated = true;
1267 }
1268 _allocated_escapes = false;
1269 _unknown_modified = false;
1270 }
1271
1272 void BCEscapeAnalyzer::clear_escape_info() {
1273 ciSignature* sig = method()->signature();
1274 int arg_count = sig->count();
1275 ArgumentMap var;
1276 if (!method()->is_static()) {
1277 arg_count++; // allow for "this"
1278 }
1279 for (int i = 0; i < arg_count; i++) {
1280 set_arg_modified(i, OFFSET_ANY, 4);
1281 var.clear();
1282 var.set(i);
1283 set_modified(var, OFFSET_ANY, 4);
1284 set_global_escape(var);
1285 }
1286 _arg_local.Clear();
1287 _arg_stack.Clear();
1288 _arg_returned.Clear();
1289 _return_local = false;
1290 _return_allocated = false;
1291 _allocated_escapes = true;
1292 _unknown_modified = true;
1293 }
1294
1295
1296 void BCEscapeAnalyzer::compute_escape_info() {
1297 int i;
1298 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1299
1300 vmIntrinsics::ID iid = known_intrinsic();
1301
1302 // check if method can be analyzed
1303 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1304 || _level > MaxBCEAEstimateLevel
1305 || method()->code_size() > MaxBCEAEstimateSize)) {
1306 if (BCEATraceLevel >= 1) {
1307 tty->print("Skipping method because: ");
1308 if (method()->is_abstract())
1309 tty->print_cr("method is abstract.");
1310 else if (method()->is_native())
1311 tty->print_cr("method is native.");
1312 else if (!method()->holder()->is_initialized())
1313 tty->print_cr("class of method is not initialized.");
1314 else if (_level > MaxBCEAEstimateLevel)
1315 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1316 _level, (int) MaxBCEAEstimateLevel);
1317 else if (method()->code_size() > MaxBCEAEstimateSize)
1318 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1319 method()->code_size(), (int) MaxBCEAEstimateSize);
1320 else
1321 ShouldNotReachHere();
1322 }
1323 clear_escape_info();
1324
1325 return;
1326 }
1327
1328 if (BCEATraceLevel >= 1) {
1329 tty->print("[EA] estimating escape information for");
1330 if (iid != vmIntrinsics::_none)
1331 tty->print(" intrinsic");
1332 method()->print_short_name();
1333 tty->print_cr(" (%d bytes)", method()->code_size());
1334 }
1335
1336 bool success;
1337
1338 initialize();
1339
1340 // Do not scan method if it has no object parameters and
1341 // does not returns an object (_return_allocated is set in initialize()).
1342 if (_arg_local.Size() == 0 && !_return_allocated) {
1343 // Clear all info since method's bytecode was not analysed and
1344 // set pessimistic escape information.
1345 clear_escape_info();
1346 methodData()->set_eflag(MethodData::allocated_escapes);
1347 methodData()->set_eflag(MethodData::unknown_modified);
1348 methodData()->set_eflag(MethodData::estimated);
1349 return;
1350 }
1351
1352 if (iid != vmIntrinsics::_none)
1353 success = compute_escape_for_intrinsic(iid);
1354 else {
1355 success = do_analysis();
1356 }
1357
1358 // don't store interprocedural escape information if it introduces
1359 // dependencies or if method data is empty
1360 //
1361 if (!has_dependencies() && !methodData()->is_empty()) {
1362 for (i = 0; i < _arg_size; i++) {
1363 if (_arg_local.test(i)) {
1364 assert(_arg_stack.test(i), "inconsistent escape info");
1365 methodData()->set_arg_local(i);
1366 methodData()->set_arg_stack(i);
1367 } else if (_arg_stack.test(i)) {
1368 methodData()->set_arg_stack(i);
1369 }
1370 if (_arg_returned.test(i)) {
1371 methodData()->set_arg_returned(i);
1372 }
1373 methodData()->set_arg_modified(i, _arg_modified[i]);
1374 }
1375 if (_return_local) {
1376 methodData()->set_eflag(MethodData::return_local);
1377 }
1378 if (_return_allocated) {
1379 methodData()->set_eflag(MethodData::return_allocated);
1380 }
1381 if (_allocated_escapes) {
1382 methodData()->set_eflag(MethodData::allocated_escapes);
1383 }
1384 if (_unknown_modified) {
1385 methodData()->set_eflag(MethodData::unknown_modified);
1386 }
1387 methodData()->set_eflag(MethodData::estimated);
1388 }
1389 }
1390
1391 void BCEscapeAnalyzer::read_escape_info() {
1392 assert(methodData()->has_escape_info(), "no escape info available");
1393
1394 // read escape information from method descriptor
1395 for (int i = 0; i < _arg_size; i++) {
1396 if (methodData()->is_arg_local(i))
1397 _arg_local.set(i);
1398 if (methodData()->is_arg_stack(i))
1399 _arg_stack.set(i);
1400 if (methodData()->is_arg_returned(i))
1401 _arg_returned.set(i);
1402 _arg_modified[i] = methodData()->arg_modified(i);
1403 }
1404 _return_local = methodData()->eflag_set(MethodData::return_local);
1405 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1406 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1407 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1408
1409 }
1410
1411 #ifndef PRODUCT
1412 void BCEscapeAnalyzer::dump() {
1413 tty->print("[EA] estimated escape information for");
1414 method()->print_short_name();
1415 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1416 tty->print(" non-escaping args: ");
1417 _arg_local.print();
1418 tty->print(" stack-allocatable args: ");
1419 _arg_stack.print();
1420 if (_return_local) {
1421 tty->print(" returned args: ");
1422 _arg_returned.print();
1423 } else if (is_return_allocated()) {
1424 tty->print_cr(" return allocated value");
1425 } else {
1426 tty->print_cr(" return non-local value");
1427 }
1428 tty->print(" modified args: ");
1429 for (int i = 0; i < _arg_size; i++) {
1430 if (_arg_modified[i] == 0)
1431 tty->print(" 0");
1432 else
1433 tty->print(" 0x%x", _arg_modified[i]);
1434 }
1435 tty->cr();
1436 tty->print(" flags: ");
1437 if (_return_allocated)
1438 tty->print(" return_allocated");
1439 if (_allocated_escapes)
1440 tty->print(" allocated_escapes");
1441 if (_unknown_modified)
1442 tty->print(" unknown_modified");
1443 tty->cr();
1444 }
1445 #endif
1446
1447 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1448 : _conservative(method == NULL || !EstimateArgEscape)
1449 , _arena(CURRENT_ENV->arena())
1450 , _method(method)
1451 , _methodData(method ? method->method_data() : NULL)
1452 , _arg_size(method ? method->arg_size() : 0)
1453 , _arg_local(_arena)
1454 , _arg_stack(_arena)
1455 , _arg_returned(_arena)
1456 , _dirty(_arena)
1457 , _return_local(false)
1458 , _return_allocated(false)
1459 , _allocated_escapes(false)
1460 , _unknown_modified(false)
1461 , _dependencies(_arena, 4, 0, NULL)
1462 , _parent(parent)
1463 , _level(parent == NULL ? 0 : parent->level() + 1) {
1464 if (!_conservative) {
1465 _arg_local.Clear();
1466 _arg_stack.Clear();
1467 _arg_returned.Clear();
1468 _dirty.Clear();
1469 Arena* arena = CURRENT_ENV->arena();
1470 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1471 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1472
1473 if (methodData() == NULL)
1474 return;
1475 if (methodData()->has_escape_info()) {
1476 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1477 method->holder()->name()->as_utf8(),
1478 method->name()->as_utf8()));
1479 read_escape_info();
1480 } else {
1481 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1482 method->holder()->name()->as_utf8(),
1483 method->name()->as_utf8()));
1484
1485 compute_escape_info();
1486 methodData()->update_escape_info();
1487 }
1488 #ifndef PRODUCT
1489 if (BCEATraceLevel >= 3) {
1490 // dump escape information
1491 dump();
1492 }
1493 #endif
1494 }
1495 }
1496
1497 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1498 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1499 // Also record evol dependencies so redefinition of the
1500 // callee will trigger recompilation.
1501 deps->assert_evol_method(method());
1502 }
1503 for (int i = 0; i < _dependencies.length(); i+=2) {
1504 ciKlass *k = _dependencies.at(i)->as_klass();
1505 ciMethod *m = _dependencies.at(i+1)->as_method();
1506 deps->assert_unique_concrete_method(k, m);
1507 }
1508 }