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