1 /*
2 * Copyright (c) 2005, 2020, 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 #include "utilities/copy.hpp"
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
int_to_bit(uint e) const59 uint int_to_bit(uint e) const {
60 if (e > MAXBIT)
61 e = MAXBIT;
62 return (1 << (e + 2));
63 }
64
65 public:
ArgumentMap()66 ArgumentMap() { _bits = 0;}
set_bits(uint bits)67 void set_bits(uint bits) { _bits = bits;}
get_bits() const68 uint get_bits() const { return _bits;}
clear()69 void clear() { _bits = 0;}
set_all()70 void set_all() { _bits = ~0u; }
is_empty() const71 bool is_empty() const { return _bits == 0; }
contains(uint var) const72 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
is_singleton(uint var) const73 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
contains_unknown() const74 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
contains_allocated() const75 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
contains_vars() const76 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
set(uint var)77 void set(uint var) { _bits = int_to_bit(var); }
add(uint var)78 void add(uint var) { _bits |= int_to_bit(var); }
add_unknown()79 void add_unknown() { _bits = UNKNOWN; }
add_allocated()80 void add_allocated() { _bits = ALLOCATED; }
set_union(const ArgumentMap & am)81 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
set_difference(const ArgumentMap & am)82 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
operator ==(const ArgumentMap & am)83 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
operator !=(const ArgumentMap & am)84 bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
85 };
86
87 class BCEscapeAnalyzer::StateInfo {
88 public:
89 ArgumentMap *_vars;
90 ArgumentMap *_stack;
91 int _stack_height;
92 int _max_stack;
93 bool _initialized;
94 ArgumentMap empty_map;
95
StateInfo()96 StateInfo() {
97 empty_map.clear();
98 }
99
raw_pop()100 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
apop()101 ArgumentMap apop() { return raw_pop(); }
spop()102 void spop() { raw_pop(); }
lpop()103 void lpop() { spop(); spop(); }
raw_push(ArgumentMap i)104 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
apush(ArgumentMap i)105 void apush(ArgumentMap i) { raw_push(i); }
spush()106 void spush() { raw_push(empty_map); }
lpush()107 void lpush() { spush(); spush(); }
108
109 };
110
set_returned(ArgumentMap vars)111 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
112 for (int i = 0; i < _arg_size; i++) {
113 if (vars.contains(i))
114 _arg_returned.set(i);
115 }
116 _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
117 _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
118 }
119
120 // return true if any element of vars is an argument
is_argument(ArgumentMap vars)121 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
122 for (int i = 0; i < _arg_size; i++) {
123 if (vars.contains(i))
124 return true;
125 }
126 return false;
127 }
128
129 // return true if any element of vars is an arg_stack argument
is_arg_stack(ArgumentMap vars)130 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
131 if (_conservative)
132 return true;
133 for (int i = 0; i < _arg_size; i++) {
134 if (vars.contains(i) && _arg_stack.test(i))
135 return true;
136 }
137 return false;
138 }
139
140 // return true if all argument elements of vars are returned
returns_all(ArgumentMap vars)141 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
142 for (int i = 0; i < _arg_size; i++) {
143 if (vars.contains(i) && !_arg_returned.test(i)) {
144 return false;
145 }
146 }
147 return true;
148 }
149
clear_bits(ArgumentMap vars,VectorSet & bm)150 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
151 for (int i = 0; i < _arg_size; i++) {
152 if (vars.contains(i)) {
153 bm.remove(i);
154 }
155 }
156 }
157
set_method_escape(ArgumentMap vars)158 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
159 clear_bits(vars, _arg_local);
160 if (vars.contains_allocated()) {
161 _allocated_escapes = true;
162 }
163 }
164
set_global_escape(ArgumentMap vars,bool merge)165 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
166 clear_bits(vars, _arg_local);
167 clear_bits(vars, _arg_stack);
168 if (vars.contains_allocated())
169 _allocated_escapes = true;
170
171 if (merge && !vars.is_empty()) {
172 // Merge new state into already processed block.
173 // New state is not taken into account and
174 // it may invalidate set_returned() result.
175 if (vars.contains_unknown() || vars.contains_allocated()) {
176 _return_local = false;
177 }
178 if (vars.contains_unknown() || vars.contains_vars()) {
179 _return_allocated = false;
180 }
181 if (_return_local && vars.contains_vars() && !returns_all(vars)) {
182 // Return result should be invalidated if args in new
183 // state are not recorded in return state.
184 _return_local = false;
185 }
186 }
187 }
188
set_dirty(ArgumentMap vars)189 void BCEscapeAnalyzer::set_dirty(ArgumentMap vars) {
190 clear_bits(vars, _dirty);
191 }
192
set_modified(ArgumentMap vars,int offs,int size)193 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
194
195 for (int i = 0; i < _arg_size; i++) {
196 if (vars.contains(i)) {
197 set_arg_modified(i, offs, size);
198 }
199 }
200 if (vars.contains_unknown())
201 _unknown_modified = true;
202 }
203
is_recursive_call(ciMethod * callee)204 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
205 for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
206 if (scope->method() == callee) {
207 return true;
208 }
209 }
210 return false;
211 }
212
is_arg_modified(int arg,int offset,int size_in_bytes)213 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
214 if (offset == OFFSET_ANY)
215 return _arg_modified[arg] != 0;
216 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
217 bool modified = false;
218 int l = offset / HeapWordSize;
219 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
220 if (l > ARG_OFFSET_MAX)
221 l = ARG_OFFSET_MAX;
222 if (h > ARG_OFFSET_MAX+1)
223 h = ARG_OFFSET_MAX + 1;
224 for (int i = l; i < h; i++) {
225 modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
226 }
227 return modified;
228 }
229
set_arg_modified(int arg,int offset,int size_in_bytes)230 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
231 if (offset == OFFSET_ANY) {
232 _arg_modified[arg] = (uint) -1;
233 return;
234 }
235 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
236 int l = offset / HeapWordSize;
237 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
238 if (l > ARG_OFFSET_MAX)
239 l = ARG_OFFSET_MAX;
240 if (h > ARG_OFFSET_MAX+1)
241 h = ARG_OFFSET_MAX + 1;
242 for (int i = l; i < h; i++) {
243 _arg_modified[arg] |= (1 << i);
244 }
245 }
246
invoke(StateInfo & state,Bytecodes::Code code,ciMethod * target,ciKlass * holder)247 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
248 int i;
249
250 // retrieve information about the callee
251 ciInstanceKlass* klass = target->holder();
252 ciInstanceKlass* calling_klass = method()->holder();
253 ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
254 ciInstanceKlass* actual_recv = callee_holder;
255
256 // Some methods are obviously bindable without any type checks so
257 // convert them directly to an invokespecial or invokestatic.
258 if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
259 switch (code) {
260 case Bytecodes::_invokevirtual:
261 code = Bytecodes::_invokespecial;
262 break;
263 case Bytecodes::_invokehandle:
264 code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
265 break;
266 default:
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 ||
345 (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
contains(uint arg_set1,uint arg_set2)366 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
367 return ((~arg_set1) | arg_set2) == 0;
368 }
369
370
iterate_one_block(ciBlock * blk,StateInfo & state,GrowableArray<ciBlock * > & successors)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 (is_reference_type(field_type)) {
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 (is_reference_type(field_type)) {
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
merge_block_states(StateInfo * blockstates,ciBlock * dest,StateInfo * s_state)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
iterate_blocks(Arena * arena)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
do_analysis()1199 void 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 }
1206
known_intrinsic()1207 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
1208 vmIntrinsics::ID iid = method()->intrinsic_id();
1209 if (iid == vmIntrinsics::_getClass ||
1210 iid == vmIntrinsics::_hashCode) {
1211 return iid;
1212 } else {
1213 return vmIntrinsics::_none;
1214 }
1215 }
1216
compute_escape_for_intrinsic(vmIntrinsics::ID iid)1217 void BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
1218 switch (iid) {
1219 case vmIntrinsics::_getClass:
1220 _return_local = false;
1221 _return_allocated = false;
1222 break;
1223 case vmIntrinsics::_hashCode:
1224 // initialized state is correct
1225 break;
1226 default:
1227 assert(false, "unexpected intrinsic");
1228 }
1229 }
1230
initialize()1231 void BCEscapeAnalyzer::initialize() {
1232 int i;
1233
1234 // clear escape information (method may have been deoptimized)
1235 methodData()->clear_escape_info();
1236
1237 // initialize escape state of object parameters
1238 ciSignature* sig = method()->signature();
1239 int j = 0;
1240 if (!method()->is_static()) {
1241 _arg_local.set(0);
1242 _arg_stack.set(0);
1243 j++;
1244 }
1245 for (i = 0; i < sig->count(); i++) {
1246 ciType* t = sig->type_at(i);
1247 if (!t->is_primitive_type()) {
1248 _arg_local.set(j);
1249 _arg_stack.set(j);
1250 }
1251 j += t->size();
1252 }
1253 assert(j == _arg_size, "just checking");
1254
1255 // start with optimistic assumption
1256 ciType *rt = _method->return_type();
1257 if (rt->is_primitive_type()) {
1258 _return_local = false;
1259 _return_allocated = false;
1260 } else {
1261 _return_local = true;
1262 _return_allocated = true;
1263 }
1264 _allocated_escapes = false;
1265 _unknown_modified = false;
1266 }
1267
clear_escape_info()1268 void BCEscapeAnalyzer::clear_escape_info() {
1269 ciSignature* sig = method()->signature();
1270 int arg_count = sig->count();
1271 ArgumentMap var;
1272 if (!method()->is_static()) {
1273 arg_count++; // allow for "this"
1274 }
1275 for (int i = 0; i < arg_count; i++) {
1276 set_arg_modified(i, OFFSET_ANY, 4);
1277 var.clear();
1278 var.set(i);
1279 set_modified(var, OFFSET_ANY, 4);
1280 set_global_escape(var);
1281 }
1282 _arg_local.clear();
1283 _arg_stack.clear();
1284 _arg_returned.clear();
1285 _return_local = false;
1286 _return_allocated = false;
1287 _allocated_escapes = true;
1288 _unknown_modified = true;
1289 }
1290
1291
compute_escape_info()1292 void BCEscapeAnalyzer::compute_escape_info() {
1293 int i;
1294 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1295
1296 vmIntrinsics::ID iid = known_intrinsic();
1297
1298 // check if method can be analyzed
1299 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1300 || _level > MaxBCEAEstimateLevel
1301 || method()->code_size() > MaxBCEAEstimateSize)) {
1302 if (BCEATraceLevel >= 1) {
1303 tty->print("Skipping method because: ");
1304 if (method()->is_abstract())
1305 tty->print_cr("method is abstract.");
1306 else if (method()->is_native())
1307 tty->print_cr("method is native.");
1308 else if (!method()->holder()->is_initialized())
1309 tty->print_cr("class of method is not initialized.");
1310 else if (_level > MaxBCEAEstimateLevel)
1311 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1312 _level, (int) MaxBCEAEstimateLevel);
1313 else if (method()->code_size() > MaxBCEAEstimateSize)
1314 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1315 method()->code_size(), (int) MaxBCEAEstimateSize);
1316 else
1317 ShouldNotReachHere();
1318 }
1319 clear_escape_info();
1320
1321 return;
1322 }
1323
1324 if (BCEATraceLevel >= 1) {
1325 tty->print("[EA] estimating escape information for");
1326 if (iid != vmIntrinsics::_none)
1327 tty->print(" intrinsic");
1328 method()->print_short_name();
1329 tty->print_cr(" (%d bytes)", method()->code_size());
1330 }
1331
1332 initialize();
1333
1334 // Do not scan method if it has no object parameters and
1335 // does not returns an object (_return_allocated is set in initialize()).
1336 if (_arg_local.is_empty() && !_return_allocated) {
1337 // Clear all info since method's bytecode was not analysed and
1338 // set pessimistic escape information.
1339 clear_escape_info();
1340 methodData()->set_eflag(MethodData::allocated_escapes);
1341 methodData()->set_eflag(MethodData::unknown_modified);
1342 methodData()->set_eflag(MethodData::estimated);
1343 return;
1344 }
1345
1346 if (iid != vmIntrinsics::_none)
1347 compute_escape_for_intrinsic(iid);
1348 else {
1349 do_analysis();
1350 }
1351
1352 // don't store interprocedural escape information if it introduces
1353 // dependencies or if method data is empty
1354 //
1355 if (!has_dependencies() && !methodData()->is_empty()) {
1356 for (i = 0; i < _arg_size; i++) {
1357 if (_arg_local.test(i)) {
1358 assert(_arg_stack.test(i), "inconsistent escape info");
1359 methodData()->set_arg_local(i);
1360 methodData()->set_arg_stack(i);
1361 } else if (_arg_stack.test(i)) {
1362 methodData()->set_arg_stack(i);
1363 }
1364 if (_arg_returned.test(i)) {
1365 methodData()->set_arg_returned(i);
1366 }
1367 methodData()->set_arg_modified(i, _arg_modified[i]);
1368 }
1369 if (_return_local) {
1370 methodData()->set_eflag(MethodData::return_local);
1371 }
1372 if (_return_allocated) {
1373 methodData()->set_eflag(MethodData::return_allocated);
1374 }
1375 if (_allocated_escapes) {
1376 methodData()->set_eflag(MethodData::allocated_escapes);
1377 }
1378 if (_unknown_modified) {
1379 methodData()->set_eflag(MethodData::unknown_modified);
1380 }
1381 methodData()->set_eflag(MethodData::estimated);
1382 }
1383 }
1384
read_escape_info()1385 void BCEscapeAnalyzer::read_escape_info() {
1386 assert(methodData()->has_escape_info(), "no escape info available");
1387
1388 // read escape information from method descriptor
1389 for (int i = 0; i < _arg_size; i++) {
1390 if (methodData()->is_arg_local(i))
1391 _arg_local.set(i);
1392 if (methodData()->is_arg_stack(i))
1393 _arg_stack.set(i);
1394 if (methodData()->is_arg_returned(i))
1395 _arg_returned.set(i);
1396 _arg_modified[i] = methodData()->arg_modified(i);
1397 }
1398 _return_local = methodData()->eflag_set(MethodData::return_local);
1399 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1400 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1401 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1402
1403 }
1404
1405 #ifndef PRODUCT
dump()1406 void BCEscapeAnalyzer::dump() {
1407 tty->print("[EA] estimated escape information for");
1408 method()->print_short_name();
1409 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1410 tty->print(" non-escaping args: ");
1411 _arg_local.print();
1412 tty->print(" stack-allocatable args: ");
1413 _arg_stack.print();
1414 if (_return_local) {
1415 tty->print(" returned args: ");
1416 _arg_returned.print();
1417 } else if (is_return_allocated()) {
1418 tty->print_cr(" return allocated value");
1419 } else {
1420 tty->print_cr(" return non-local value");
1421 }
1422 tty->print(" modified args: ");
1423 for (int i = 0; i < _arg_size; i++) {
1424 if (_arg_modified[i] == 0)
1425 tty->print(" 0");
1426 else
1427 tty->print(" 0x%x", _arg_modified[i]);
1428 }
1429 tty->cr();
1430 tty->print(" flags: ");
1431 if (_return_allocated)
1432 tty->print(" return_allocated");
1433 if (_allocated_escapes)
1434 tty->print(" allocated_escapes");
1435 if (_unknown_modified)
1436 tty->print(" unknown_modified");
1437 tty->cr();
1438 }
1439 #endif
1440
BCEscapeAnalyzer(ciMethod * method,BCEscapeAnalyzer * parent)1441 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1442 : _arena(CURRENT_ENV->arena())
1443 , _conservative(method == NULL || !EstimateArgEscape)
1444 , _method(method)
1445 , _methodData(method ? method->method_data() : NULL)
1446 , _arg_size(method ? method->arg_size() : 0)
1447 , _arg_local(_arena)
1448 , _arg_stack(_arena)
1449 , _arg_returned(_arena)
1450 , _dirty(_arena)
1451 , _return_local(false)
1452 , _return_allocated(false)
1453 , _allocated_escapes(false)
1454 , _unknown_modified(false)
1455 , _dependencies(_arena, 4, 0, NULL)
1456 , _parent(parent)
1457 , _level(parent == NULL ? 0 : parent->level() + 1) {
1458 if (!_conservative) {
1459 _arg_local.clear();
1460 _arg_stack.clear();
1461 _arg_returned.clear();
1462 _dirty.clear();
1463 Arena* arena = CURRENT_ENV->arena();
1464 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1465 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1466
1467 if (methodData() == NULL)
1468 return;
1469 if (methodData()->has_escape_info()) {
1470 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1471 method->holder()->name()->as_utf8(),
1472 method->name()->as_utf8()));
1473 read_escape_info();
1474 } else {
1475 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1476 method->holder()->name()->as_utf8(),
1477 method->name()->as_utf8()));
1478
1479 compute_escape_info();
1480 methodData()->update_escape_info();
1481 }
1482 #ifndef PRODUCT
1483 if (BCEATraceLevel >= 3) {
1484 // dump escape information
1485 dump();
1486 }
1487 #endif
1488 }
1489 }
1490
copy_dependencies(Dependencies * deps)1491 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1492 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1493 // Also record evol dependencies so redefinition of the
1494 // callee will trigger recompilation.
1495 deps->assert_evol_method(method());
1496 }
1497 for (int i = 0; i < _dependencies.length(); i+=2) {
1498 ciKlass *k = _dependencies.at(i)->as_klass();
1499 ciMethod *m = _dependencies.at(i+1)->as_method();
1500 deps->assert_unique_concrete_method(k, m);
1501 }
1502 }
1503