1 /*
2 * Copyright (c) 2005, 2025, 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 "ci/bcEscapeAnalyzer.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciMethodBlocks.hpp"
29 #include "ci/ciStreams.hpp"
30 #include "classfile/vmIntrinsics.hpp"
31 #include "compiler/compiler_globals.hpp"
32 #include "interpreter/bytecode.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "utilities/align.hpp"
35 #include "utilities/bitMap.inline.hpp"
36 #include "utilities/copy.hpp"
37
38 #ifndef PRODUCT
39 #define TRACE_BCEA(level, code) \
40 if (EstimateArgEscape && BCEATraceLevel >= level) { \
41 code; \
42 }
43 #else
44 #define TRACE_BCEA(level, code)
45 #endif
46
47 // Maintain a map of which arguments a local variable or
48 // stack slot may contain. In addition to tracking
49 // arguments, it tracks two special values, "allocated"
50 // which represents any object allocated in the current
51 // method, and "unknown" which is any other object.
52 // Up to 30 arguments are handled, with the last one
53 // representing summary information for any extra arguments
54 class BCEscapeAnalyzer::ArgumentMap {
55 uint _bits;
56 enum {MAXBIT = 29,
57 ALLOCATED = 1,
58 UNKNOWN = 2};
59
60 uint int_to_bit(uint e) const {
61 if (e > MAXBIT)
62 e = MAXBIT;
63 return (1 << (e + 2));
64 }
65
66 public:
67 ArgumentMap() { _bits = 0;}
68 void set_bits(uint bits) { _bits = bits;}
69 uint get_bits() const { return _bits;}
70 void clear() { _bits = 0;}
71 void set_all() { _bits = ~0u; }
72 bool is_empty() const { return _bits == 0; }
73 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
74 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
75 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
76 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
77 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
78 void set(uint var) { _bits = int_to_bit(var); }
79 void add(uint var) { _bits |= int_to_bit(var); }
80 void add_unknown() { _bits = UNKNOWN; }
81 void add_allocated() { _bits = ALLOCATED; }
82 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
83 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
84 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
85 bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
86 };
87
88 class BCEscapeAnalyzer::StateInfo {
89 public:
90 ArgumentMap *_vars;
91 ArgumentMap *_stack;
92 int _stack_height;
93 int _max_stack;
94 bool _initialized;
95 ArgumentMap empty_map;
96
97 StateInfo() {
98 empty_map.clear();
99 }
100
101 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
102 ArgumentMap apop() { return raw_pop(); }
103 void spop() { raw_pop(); }
104 void lpop() { spop(); spop(); }
105 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
106 void apush(ArgumentMap i) { raw_push(i); }
107 void spush() { raw_push(empty_map); }
108 void lpush() { spush(); spush(); }
109
110 };
111
112 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
113 for (int i = 0; i < _arg_size; i++) {
114 if (vars.contains(i))
115 _arg_returned.set(i);
116 }
117 _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
118 _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
119 }
120
121 // return true if any element of vars is an argument
122 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
123 for (int i = 0; i < _arg_size; i++) {
124 if (vars.contains(i))
125 return true;
126 }
127 return false;
128 }
129
130 // return true if any element of vars is an arg_stack argument
131 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
132 if (_conservative)
133 return true;
134 for (int i = 0; i < _arg_size; i++) {
135 if (vars.contains(i) && _arg_stack.test(i))
136 return true;
137 }
138 return false;
139 }
140
141 // return true if all argument elements of vars are returned
142 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
143 for (int i = 0; i < _arg_size; i++) {
144 if (vars.contains(i) && !_arg_returned.test(i)) {
145 return false;
146 }
147 }
148 return true;
149 }
150
151 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
152 for (int i = 0; i < _arg_size; i++) {
153 if (vars.contains(i)) {
154 bm.remove(i);
155 }
156 }
157 }
158
159 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
160 clear_bits(vars, _arg_local);
161 if (vars.contains_allocated()) {
162 _allocated_escapes = true;
163 }
164 }
165
166 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
167 clear_bits(vars, _arg_local);
168 clear_bits(vars, _arg_stack);
169 if (vars.contains_allocated())
170 _allocated_escapes = true;
171
172 if (merge && !vars.is_empty()) {
173 // Merge new state into already processed block.
174 // New state is not taken into account and
175 // it may invalidate set_returned() result.
176 if (vars.contains_unknown() || vars.contains_allocated()) {
177 _return_local = false;
178 }
179 if (vars.contains_unknown() || vars.contains_vars()) {
180 _return_allocated = false;
181 }
182 if (_return_local && vars.contains_vars() && !returns_all(vars)) {
183 // Return result should be invalidated if args in new
184 // state are not recorded in return state.
185 _return_local = false;
186 }
187 }
188 }
189
190 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
191
192 for (int i = 0; i < _arg_size; i++) {
193 if (vars.contains(i)) {
194 set_arg_modified(i, offs, size);
195 }
196 }
197 if (vars.contains_unknown())
198 _unknown_modified = true;
199 }
200
201 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
202 for (BCEscapeAnalyzer* scope = this; scope != nullptr; scope = scope->_parent) {
203 if (scope->method() == callee) {
204 return true;
205 }
206 }
207 return false;
208 }
209
210 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
211 if (offset == OFFSET_ANY)
212 return _arg_modified[arg] != 0;
213 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
214 bool modified = false;
215 int l = offset / HeapWordSize;
216 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
217 if (l > ARG_OFFSET_MAX)
218 l = ARG_OFFSET_MAX;
219 if (h > ARG_OFFSET_MAX+1)
220 h = ARG_OFFSET_MAX + 1;
221 for (int i = l; i < h; i++) {
222 modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
223 }
224 return modified;
225 }
226
227 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
228 if (offset == OFFSET_ANY) {
229 _arg_modified[arg] = (uint) -1;
230 return;
231 }
232 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
233 int l = offset / HeapWordSize;
234 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
235 if (l > ARG_OFFSET_MAX)
236 l = ARG_OFFSET_MAX;
237 if (h > ARG_OFFSET_MAX+1)
238 h = ARG_OFFSET_MAX + 1;
239 for (int i = l; i < h; i++) {
240 _arg_modified[arg] |= (1 << i);
241 }
242 }
243
244 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
245 int i;
246
247 // retrieve information about the callee
248 ciInstanceKlass* klass = target->holder();
249 ciInstanceKlass* calling_klass = method()->holder();
250 ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
251 ciInstanceKlass* actual_recv = callee_holder;
252
253 // Some methods are obviously bindable without any type checks so
254 // convert them directly to an invokespecial or invokestatic.
255 if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
256 switch (code) {
257 case Bytecodes::_invokevirtual:
258 code = Bytecodes::_invokespecial;
259 break;
260 case Bytecodes::_invokehandle:
261 code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
262 break;
263 default:
264 break;
265 }
266 }
267
268 // compute size of arguments
269 int arg_size = target->invoke_arg_size(code);
270 int arg_base = MAX2(state._stack_height - arg_size, 0);
271
272 // direct recursive calls are skipped if they can be bound statically without introducing
273 // dependencies and if parameters are passed at the same position as in the current method
274 // other calls are skipped if there are no non-escaped arguments passed to them
275 bool directly_recursive = (method() == target) &&
276 (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
277
278 // check if analysis of callee can safely be skipped
279 bool skip_callee = true;
280 for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
281 ArgumentMap arg = state._stack[i];
282 skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
283 }
284 // For now we conservatively skip invokedynamic.
285 if (code == Bytecodes::_invokedynamic) {
286 skip_callee = true;
287 }
288 if (skip_callee) {
289 TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
290 for (i = 0; i < arg_size; i++) {
291 set_method_escape(state.raw_pop());
292 }
293 _unknown_modified = true; // assume the worst since we don't analyze the called method
294 return;
295 }
296
297 // determine actual method (use CHA if necessary)
298 ciMethod* inline_target = nullptr;
299 if (target->is_loaded() && klass->is_loaded()
300 && (klass->is_initialized() || (klass->is_interface() && target->holder()->is_initialized()))) {
301 if (code == Bytecodes::_invokestatic
302 || code == Bytecodes::_invokespecial
303 || (code == Bytecodes::_invokevirtual && target->is_final_method())) {
304 inline_target = target;
305 } else {
306 inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
307 }
308 }
309
310 if (inline_target != nullptr && !is_recursive_call(inline_target)) {
311 // analyze callee
312 BCEscapeAnalyzer analyzer(inline_target, this);
313
314 // adjust escape state of actual parameters
315 bool must_record_dependencies = false;
316 for (i = arg_size - 1; i >= 0; i--) {
317 ArgumentMap arg = state.raw_pop();
318 // Check if callee arg is a caller arg or an allocated object
319 bool allocated = arg.contains_allocated();
320 if (!(is_argument(arg) || allocated))
321 continue;
322 for (int j = 0; j < _arg_size; j++) {
323 if (arg.contains(j)) {
324 _arg_modified[j] |= analyzer._arg_modified[i];
325 }
326 }
327 if (!(is_arg_stack(arg) || allocated)) {
328 // arguments have already been recognized as escaping
329 } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
330 set_method_escape(arg);
331 must_record_dependencies = true;
332 } else {
333 set_global_escape(arg);
334 }
335 }
336 _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
337
338 // record dependencies if at least one parameter retained stack-allocatable
339 if (must_record_dependencies) {
340 if (code == Bytecodes::_invokeinterface ||
341 (code == Bytecodes::_invokevirtual && !target->is_final_method())) {
342 _dependencies.append(actual_recv);
343 _dependencies.append(inline_target);
344 _dependencies.append(callee_holder);
345 _dependencies.append(target);
346 assert(callee_holder->is_interface() == (code == Bytecodes::_invokeinterface), "sanity");
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 BasicType con_bt = s.get_basic_type_for_constant_at(index);
419 if (con_bt == T_LONG || con_bt == T_DOUBLE) {
420 // Only longs and doubles use 2 stack slots.
421 state.lpush();
422 } else if (con_bt == T_OBJECT) {
423 state.apush(unknown_obj);
424 } else {
425 state.spush();
426 }
427 break;
428 }
429 case Bytecodes::_aload:
430 state.apush(state._vars[s.get_index()]);
431 break;
432 case Bytecodes::_iload:
433 case Bytecodes::_fload:
434 case Bytecodes::_iload_0:
435 case Bytecodes::_iload_1:
436 case Bytecodes::_iload_2:
437 case Bytecodes::_iload_3:
438 case Bytecodes::_fload_0:
439 case Bytecodes::_fload_1:
440 case Bytecodes::_fload_2:
441 case Bytecodes::_fload_3:
442 state.spush();
443 break;
444 case Bytecodes::_lload:
445 case Bytecodes::_dload:
446 case Bytecodes::_lload_0:
447 case Bytecodes::_lload_1:
448 case Bytecodes::_lload_2:
449 case Bytecodes::_lload_3:
450 case Bytecodes::_dload_0:
451 case Bytecodes::_dload_1:
452 case Bytecodes::_dload_2:
453 case Bytecodes::_dload_3:
454 state.lpush();
455 break;
456 case Bytecodes::_aload_0:
457 state.apush(state._vars[0]);
458 break;
459 case Bytecodes::_aload_1:
460 state.apush(state._vars[1]);
461 break;
462 case Bytecodes::_aload_2:
463 state.apush(state._vars[2]);
464 break;
465 case Bytecodes::_aload_3:
466 state.apush(state._vars[3]);
467 break;
468 case Bytecodes::_iaload:
469 case Bytecodes::_faload:
470 case Bytecodes::_baload:
471 case Bytecodes::_caload:
472 case Bytecodes::_saload:
473 state.spop();
474 set_method_escape(state.apop());
475 state.spush();
476 break;
477 case Bytecodes::_laload:
478 case Bytecodes::_daload:
479 state.spop();
480 set_method_escape(state.apop());
481 state.lpush();
482 break;
483 case Bytecodes::_aaload:
484 { state.spop();
485 ArgumentMap array = state.apop();
486 set_method_escape(array);
487 state.apush(unknown_obj);
488 }
489 break;
490 case Bytecodes::_istore:
491 case Bytecodes::_fstore:
492 case Bytecodes::_istore_0:
493 case Bytecodes::_istore_1:
494 case Bytecodes::_istore_2:
495 case Bytecodes::_istore_3:
496 case Bytecodes::_fstore_0:
497 case Bytecodes::_fstore_1:
498 case Bytecodes::_fstore_2:
499 case Bytecodes::_fstore_3:
500 state.spop();
501 break;
502 case Bytecodes::_lstore:
503 case Bytecodes::_dstore:
504 case Bytecodes::_lstore_0:
505 case Bytecodes::_lstore_1:
506 case Bytecodes::_lstore_2:
507 case Bytecodes::_lstore_3:
508 case Bytecodes::_dstore_0:
509 case Bytecodes::_dstore_1:
510 case Bytecodes::_dstore_2:
511 case Bytecodes::_dstore_3:
512 state.lpop();
513 break;
514 case Bytecodes::_astore:
515 state._vars[s.get_index()] = state.apop();
516 break;
517 case Bytecodes::_astore_0:
518 state._vars[0] = state.apop();
519 break;
520 case Bytecodes::_astore_1:
521 state._vars[1] = state.apop();
522 break;
523 case Bytecodes::_astore_2:
524 state._vars[2] = state.apop();
525 break;
526 case Bytecodes::_astore_3:
527 state._vars[3] = state.apop();
528 break;
529 case Bytecodes::_iastore:
530 case Bytecodes::_fastore:
531 case Bytecodes::_bastore:
532 case Bytecodes::_castore:
533 case Bytecodes::_sastore:
534 {
535 state.spop();
536 state.spop();
537 ArgumentMap arr = state.apop();
538 set_method_escape(arr);
539 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
540 break;
541 }
542 case Bytecodes::_lastore:
543 case Bytecodes::_dastore:
544 {
545 state.lpop();
546 state.spop();
547 ArgumentMap arr = state.apop();
548 set_method_escape(arr);
549 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
550 break;
551 }
552 case Bytecodes::_aastore:
553 {
554 set_global_escape(state.apop());
555 state.spop();
556 ArgumentMap arr = state.apop();
557 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
558 break;
559 }
560 case Bytecodes::_pop:
561 state.raw_pop();
562 break;
563 case Bytecodes::_pop2:
564 state.raw_pop();
565 state.raw_pop();
566 break;
567 case Bytecodes::_dup:
568 { ArgumentMap w1 = state.raw_pop();
569 state.raw_push(w1);
570 state.raw_push(w1);
571 }
572 break;
573 case Bytecodes::_dup_x1:
574 { ArgumentMap w1 = state.raw_pop();
575 ArgumentMap w2 = state.raw_pop();
576 state.raw_push(w1);
577 state.raw_push(w2);
578 state.raw_push(w1);
579 }
580 break;
581 case Bytecodes::_dup_x2:
582 { ArgumentMap w1 = state.raw_pop();
583 ArgumentMap w2 = state.raw_pop();
584 ArgumentMap w3 = state.raw_pop();
585 state.raw_push(w1);
586 state.raw_push(w3);
587 state.raw_push(w2);
588 state.raw_push(w1);
589 }
590 break;
591 case Bytecodes::_dup2:
592 { ArgumentMap w1 = state.raw_pop();
593 ArgumentMap w2 = state.raw_pop();
594 state.raw_push(w2);
595 state.raw_push(w1);
596 state.raw_push(w2);
597 state.raw_push(w1);
598 }
599 break;
600 case Bytecodes::_dup2_x1:
601 { ArgumentMap w1 = state.raw_pop();
602 ArgumentMap w2 = state.raw_pop();
603 ArgumentMap w3 = state.raw_pop();
604 state.raw_push(w2);
605 state.raw_push(w1);
606 state.raw_push(w3);
607 state.raw_push(w2);
608 state.raw_push(w1);
609 }
610 break;
611 case Bytecodes::_dup2_x2:
612 { ArgumentMap w1 = state.raw_pop();
613 ArgumentMap w2 = state.raw_pop();
614 ArgumentMap w3 = state.raw_pop();
615 ArgumentMap w4 = state.raw_pop();
616 state.raw_push(w2);
617 state.raw_push(w1);
618 state.raw_push(w4);
619 state.raw_push(w3);
620 state.raw_push(w2);
621 state.raw_push(w1);
622 }
623 break;
624 case Bytecodes::_swap:
625 { ArgumentMap w1 = state.raw_pop();
626 ArgumentMap w2 = state.raw_pop();
627 state.raw_push(w1);
628 state.raw_push(w2);
629 }
630 break;
631 case Bytecodes::_iadd:
632 case Bytecodes::_fadd:
633 case Bytecodes::_isub:
634 case Bytecodes::_fsub:
635 case Bytecodes::_imul:
636 case Bytecodes::_fmul:
637 case Bytecodes::_idiv:
638 case Bytecodes::_fdiv:
639 case Bytecodes::_irem:
640 case Bytecodes::_frem:
641 case Bytecodes::_iand:
642 case Bytecodes::_ior:
643 case Bytecodes::_ixor:
644 state.spop();
645 state.spop();
646 state.spush();
647 break;
648 case Bytecodes::_ladd:
649 case Bytecodes::_dadd:
650 case Bytecodes::_lsub:
651 case Bytecodes::_dsub:
652 case Bytecodes::_lmul:
653 case Bytecodes::_dmul:
654 case Bytecodes::_ldiv:
655 case Bytecodes::_ddiv:
656 case Bytecodes::_lrem:
657 case Bytecodes::_drem:
658 case Bytecodes::_land:
659 case Bytecodes::_lor:
660 case Bytecodes::_lxor:
661 state.lpop();
662 state.lpop();
663 state.lpush();
664 break;
665 case Bytecodes::_ishl:
666 case Bytecodes::_ishr:
667 case Bytecodes::_iushr:
668 state.spop();
669 state.spop();
670 state.spush();
671 break;
672 case Bytecodes::_lshl:
673 case Bytecodes::_lshr:
674 case Bytecodes::_lushr:
675 state.spop();
676 state.lpop();
677 state.lpush();
678 break;
679 case Bytecodes::_ineg:
680 case Bytecodes::_fneg:
681 state.spop();
682 state.spush();
683 break;
684 case Bytecodes::_lneg:
685 case Bytecodes::_dneg:
686 state.lpop();
687 state.lpush();
688 break;
689 case Bytecodes::_iinc:
690 break;
691 case Bytecodes::_i2l:
692 case Bytecodes::_i2d:
693 case Bytecodes::_f2l:
694 case Bytecodes::_f2d:
695 state.spop();
696 state.lpush();
697 break;
698 case Bytecodes::_i2f:
699 case Bytecodes::_f2i:
700 state.spop();
701 state.spush();
702 break;
703 case Bytecodes::_l2i:
704 case Bytecodes::_l2f:
705 case Bytecodes::_d2i:
706 case Bytecodes::_d2f:
707 state.lpop();
708 state.spush();
709 break;
710 case Bytecodes::_l2d:
711 case Bytecodes::_d2l:
712 state.lpop();
713 state.lpush();
714 break;
715 case Bytecodes::_i2b:
716 case Bytecodes::_i2c:
717 case Bytecodes::_i2s:
718 state.spop();
719 state.spush();
720 break;
721 case Bytecodes::_lcmp:
722 case Bytecodes::_dcmpl:
723 case Bytecodes::_dcmpg:
724 state.lpop();
725 state.lpop();
726 state.spush();
727 break;
728 case Bytecodes::_fcmpl:
729 case Bytecodes::_fcmpg:
730 state.spop();
731 state.spop();
732 state.spush();
733 break;
734 case Bytecodes::_ifeq:
735 case Bytecodes::_ifne:
736 case Bytecodes::_iflt:
737 case Bytecodes::_ifge:
738 case Bytecodes::_ifgt:
739 case Bytecodes::_ifle:
740 {
741 state.spop();
742 int dest_bci = s.get_dest();
743 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
744 assert(s.next_bci() == limit_bci, "branch must end block");
745 successors.push(_methodBlocks->block_containing(dest_bci));
746 break;
747 }
748 case Bytecodes::_if_icmpeq:
749 case Bytecodes::_if_icmpne:
750 case Bytecodes::_if_icmplt:
751 case Bytecodes::_if_icmpge:
752 case Bytecodes::_if_icmpgt:
753 case Bytecodes::_if_icmple:
754 {
755 state.spop();
756 state.spop();
757 int dest_bci = s.get_dest();
758 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
759 assert(s.next_bci() == limit_bci, "branch must end block");
760 successors.push(_methodBlocks->block_containing(dest_bci));
761 break;
762 }
763 case Bytecodes::_if_acmpeq:
764 case Bytecodes::_if_acmpne:
765 {
766 set_method_escape(state.apop());
767 set_method_escape(state.apop());
768 int dest_bci = s.get_dest();
769 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
770 assert(s.next_bci() == limit_bci, "branch must end block");
771 successors.push(_methodBlocks->block_containing(dest_bci));
772 break;
773 }
774 case Bytecodes::_goto:
775 {
776 int dest_bci = s.get_dest();
777 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
778 assert(s.next_bci() == limit_bci, "branch must end block");
779 successors.push(_methodBlocks->block_containing(dest_bci));
780 fall_through = false;
781 break;
782 }
783 case Bytecodes::_jsr:
784 {
785 int dest_bci = s.get_dest();
786 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
787 assert(s.next_bci() == limit_bci, "branch must end block");
788 state.apush(empty_map);
789 successors.push(_methodBlocks->block_containing(dest_bci));
790 fall_through = false;
791 break;
792 }
793 case Bytecodes::_ret:
794 // we don't track the destination of a "ret" instruction
795 assert(s.next_bci() == limit_bci, "branch must end block");
796 fall_through = false;
797 break;
798 case Bytecodes::_return:
799 assert(s.next_bci() == limit_bci, "return must end block");
800 fall_through = false;
801 break;
802 case Bytecodes::_tableswitch:
803 {
804 state.spop();
805 Bytecode_tableswitch sw(&s);
806 int len = sw.length();
807 int dest_bci;
808 for (int i = 0; i < len; i++) {
809 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
810 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
811 successors.push(_methodBlocks->block_containing(dest_bci));
812 }
813 dest_bci = s.cur_bci() + sw.default_offset();
814 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
815 successors.push(_methodBlocks->block_containing(dest_bci));
816 assert(s.next_bci() == limit_bci, "branch must end block");
817 fall_through = false;
818 break;
819 }
820 case Bytecodes::_lookupswitch:
821 {
822 state.spop();
823 Bytecode_lookupswitch sw(&s);
824 int len = sw.number_of_pairs();
825 int dest_bci;
826 for (int i = 0; i < len; i++) {
827 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
828 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
829 successors.push(_methodBlocks->block_containing(dest_bci));
830 }
831 dest_bci = s.cur_bci() + sw.default_offset();
832 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
833 successors.push(_methodBlocks->block_containing(dest_bci));
834 fall_through = false;
835 break;
836 }
837 case Bytecodes::_ireturn:
838 case Bytecodes::_freturn:
839 state.spop();
840 fall_through = false;
841 break;
842 case Bytecodes::_lreturn:
843 case Bytecodes::_dreturn:
844 state.lpop();
845 fall_through = false;
846 break;
847 case Bytecodes::_areturn:
848 set_returned(state.apop());
849 fall_through = false;
850 break;
851 case Bytecodes::_getstatic:
852 case Bytecodes::_getfield:
853 { bool ignored_will_link;
854 ciField* field = s.get_field(ignored_will_link);
855 BasicType field_type = field->type()->basic_type();
856 if (s.cur_bc() != Bytecodes::_getstatic) {
857 set_method_escape(state.apop());
858 }
859 if (is_reference_type(field_type)) {
860 state.apush(unknown_obj);
861 } else if (type2size[field_type] == 1) {
862 state.spush();
863 } else {
864 state.lpush();
865 }
866 }
867 break;
868 case Bytecodes::_putstatic:
869 case Bytecodes::_putfield:
870 { bool will_link;
871 ciField* field = s.get_field(will_link);
872 BasicType field_type = field->type()->basic_type();
873 if (is_reference_type(field_type)) {
874 set_global_escape(state.apop());
875 } else if (type2size[field_type] == 1) {
876 state.spop();
877 } else {
878 state.lpop();
879 }
880 if (s.cur_bc() != Bytecodes::_putstatic) {
881 ArgumentMap p = state.apop();
882 set_method_escape(p);
883 set_modified(p, will_link ? field->offset_in_bytes() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
884 }
885 }
886 break;
887 case Bytecodes::_invokevirtual:
888 case Bytecodes::_invokespecial:
889 case Bytecodes::_invokestatic:
890 case Bytecodes::_invokedynamic:
891 case Bytecodes::_invokeinterface:
892 { bool ignored_will_link;
893 ciSignature* declared_signature = nullptr;
894 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
895 ciKlass* holder = s.get_declared_method_holder();
896 assert(declared_signature != nullptr, "cannot be null");
897 // If the current bytecode has an attached appendix argument,
898 // push an unknown object to represent that argument. (Analysis
899 // of dynamic call sites, especially invokehandle calls, needs
900 // the appendix argument on the stack, in addition to "regular" arguments
901 // pushed onto the stack by bytecode instructions preceding the call.)
902 //
903 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
904 // method to determine whether the current bytecode has an appendix argument.
905 // The has_appendix() method obtains the appendix from the
906 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
907 // resolution of dynamic call sites. Callees in the
908 // ciBytecodeStream::get_method() call above also access the _f1 field;
909 // interleaving the get_method() and has_appendix() calls in the current
910 // method with call site resolution can lead to an inconsistent view of
911 // the current method's argument count. In particular, some interleaving(s)
912 // can cause the method's argument count to not include the appendix, which
913 // then leads to stack over-/underflow in the escape analyzer.
914 //
915 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
916 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
917 // instructions, except if the call site is the _invokeBasic intrinsic
918 // (that intrinsic is always targeted by an invokehandle instruction but does
919 // not have an appendix argument).
920 if (target->is_loaded() &&
921 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
922 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
923 state.apush(unknown_obj);
924 }
925 // Pass in raw bytecode because we need to see invokehandle instructions.
926 invoke(state, s.cur_bc_raw(), target, holder);
927 // We are using the return type of the declared signature here because
928 // it might be a more concrete type than the one from the target (for
929 // e.g. invokedynamic and invokehandle).
930 ciType* return_type = declared_signature->return_type();
931 if (!return_type->is_primitive_type()) {
932 state.apush(unknown_obj);
933 } else if (return_type->is_one_word()) {
934 state.spush();
935 } else if (return_type->is_two_word()) {
936 state.lpush();
937 }
938 }
939 break;
940 case Bytecodes::_new:
941 state.apush(allocated_obj);
942 break;
943 case Bytecodes::_newarray:
944 case Bytecodes::_anewarray:
945 state.spop();
946 state.apush(allocated_obj);
947 break;
948 case Bytecodes::_multianewarray:
949 { int i = s.cur_bcp()[3];
950 while (i-- > 0) state.spop();
951 state.apush(allocated_obj);
952 }
953 break;
954 case Bytecodes::_arraylength:
955 set_method_escape(state.apop());
956 state.spush();
957 break;
958 case Bytecodes::_athrow:
959 set_global_escape(state.apop());
960 fall_through = false;
961 break;
962 case Bytecodes::_checkcast:
963 { ArgumentMap obj = state.apop();
964 set_method_escape(obj);
965 state.apush(obj);
966 }
967 break;
968 case Bytecodes::_instanceof:
969 set_method_escape(state.apop());
970 state.spush();
971 break;
972 case Bytecodes::_monitorenter:
973 case Bytecodes::_monitorexit:
974 state.apop();
975 break;
976 case Bytecodes::_wide:
977 ShouldNotReachHere();
978 break;
979 case Bytecodes::_ifnull:
980 case Bytecodes::_ifnonnull:
981 {
982 set_method_escape(state.apop());
983 int dest_bci = s.get_dest();
984 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
985 assert(s.next_bci() == limit_bci, "branch must end block");
986 successors.push(_methodBlocks->block_containing(dest_bci));
987 break;
988 }
989 case Bytecodes::_goto_w:
990 {
991 int dest_bci = s.get_far_dest();
992 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
993 assert(s.next_bci() == limit_bci, "branch must end block");
994 successors.push(_methodBlocks->block_containing(dest_bci));
995 fall_through = false;
996 break;
997 }
998 case Bytecodes::_jsr_w:
999 {
1000 int dest_bci = s.get_far_dest();
1001 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1002 assert(s.next_bci() == limit_bci, "branch must end block");
1003 state.apush(empty_map);
1004 successors.push(_methodBlocks->block_containing(dest_bci));
1005 fall_through = false;
1006 break;
1007 }
1008 case Bytecodes::_breakpoint:
1009 break;
1010 default:
1011 ShouldNotReachHere();
1012 break;
1013 }
1014
1015 }
1016 if (fall_through) {
1017 int fall_through_bci = s.cur_bci();
1018 if (fall_through_bci < _method->code_size()) {
1019 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1020 successors.push(_methodBlocks->block_containing(fall_through_bci));
1021 }
1022 }
1023 }
1024
1025 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1026 StateInfo *d_state = blockstates + dest->index();
1027 int nlocals = _method->max_locals();
1028
1029 // exceptions may cause transfer of control to handlers in the middle of a
1030 // block, so we don't merge the incoming state of exception handlers
1031 if (dest->is_handler())
1032 return;
1033 if (!d_state->_initialized ) {
1034 // destination not initialized, just copy
1035 for (int i = 0; i < nlocals; i++) {
1036 d_state->_vars[i] = s_state->_vars[i];
1037 }
1038 for (int i = 0; i < s_state->_stack_height; i++) {
1039 d_state->_stack[i] = s_state->_stack[i];
1040 }
1041 d_state->_stack_height = s_state->_stack_height;
1042 d_state->_max_stack = s_state->_max_stack;
1043 d_state->_initialized = true;
1044 } else if (!dest->processed()) {
1045 // we have not yet walked the bytecodes of dest, we can merge
1046 // the states
1047 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1048 for (int i = 0; i < nlocals; i++) {
1049 d_state->_vars[i].set_union(s_state->_vars[i]);
1050 }
1051 for (int i = 0; i < s_state->_stack_height; i++) {
1052 d_state->_stack[i].set_union(s_state->_stack[i]);
1053 }
1054 } else {
1055 // the bytecodes of dest have already been processed, mark any
1056 // arguments in the source state which are not in the dest state
1057 // as global escape.
1058 // Future refinement: we only need to mark these variable to the
1059 // maximum escape of any variables in dest state
1060 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1061 ArgumentMap extra_vars;
1062 for (int i = 0; i < nlocals; i++) {
1063 ArgumentMap t;
1064 t = s_state->_vars[i];
1065 t.set_difference(d_state->_vars[i]);
1066 extra_vars.set_union(t);
1067 }
1068 for (int i = 0; i < s_state->_stack_height; i++) {
1069 ArgumentMap t;
1070 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1071 t.clear();
1072 t = s_state->_stack[i];
1073 t.set_difference(d_state->_stack[i]);
1074 extra_vars.set_union(t);
1075 }
1076 set_global_escape(extra_vars, true);
1077 }
1078 }
1079
1080 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1081 int numblocks = _methodBlocks->num_blocks();
1082 int stkSize = _method->max_stack();
1083 int numLocals = _method->max_locals();
1084 StateInfo state;
1085
1086 int datacount = (numblocks + 1) * (stkSize + numLocals);
1087 int datasize = datacount * sizeof(ArgumentMap);
1088 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1089 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1090 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1091 ArgumentMap *dp = statedata;
1092 state._vars = dp;
1093 dp += numLocals;
1094 state._stack = dp;
1095 dp += stkSize;
1096 state._initialized = false;
1097 state._max_stack = stkSize;
1098 for (int i = 0; i < numblocks; i++) {
1099 blockstates[i]._vars = dp;
1100 dp += numLocals;
1101 blockstates[i]._stack = dp;
1102 dp += stkSize;
1103 blockstates[i]._initialized = false;
1104 blockstates[i]._stack_height = 0;
1105 blockstates[i]._max_stack = stkSize;
1106 }
1107 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, nullptr);
1108 GrowableArray<ciBlock *> successors(arena, 4, 0, nullptr);
1109
1110 _methodBlocks->clear_processed();
1111
1112 // initialize block 0 state from method signature
1113 ArgumentMap allVars; // all oop arguments to method
1114 ciSignature* sig = method()->signature();
1115 int j = 0;
1116 ciBlock* first_blk = _methodBlocks->block_containing(0);
1117 int fb_i = first_blk->index();
1118 if (!method()->is_static()) {
1119 // record information for "this"
1120 blockstates[fb_i]._vars[j].set(j);
1121 allVars.add(j);
1122 j++;
1123 }
1124 for (int i = 0; i < sig->count(); i++) {
1125 ciType* t = sig->type_at(i);
1126 if (!t->is_primitive_type()) {
1127 blockstates[fb_i]._vars[j].set(j);
1128 allVars.add(j);
1129 }
1130 j += t->size();
1131 }
1132 blockstates[fb_i]._initialized = true;
1133 assert(j == _arg_size, "just checking");
1134
1135 ArgumentMap unknown_map;
1136 unknown_map.add_unknown();
1137
1138 worklist.push(first_blk);
1139 while(worklist.length() > 0) {
1140 ciBlock *blk = worklist.pop();
1141 StateInfo *blkState = blockstates + blk->index();
1142 if (blk->is_handler() || blk->is_ret_target()) {
1143 // for an exception handler or a target of a ret instruction, we assume the worst case,
1144 // that any variable could contain any argument
1145 for (int i = 0; i < numLocals; i++) {
1146 state._vars[i] = allVars;
1147 }
1148 if (blk->is_handler()) {
1149 state._stack_height = 1;
1150 } else {
1151 state._stack_height = blkState->_stack_height;
1152 }
1153 for (int i = 0; i < state._stack_height; i++) {
1154 // ??? should this be unknown_map ???
1155 state._stack[i] = allVars;
1156 }
1157 } else {
1158 for (int i = 0; i < numLocals; i++) {
1159 state._vars[i] = blkState->_vars[i];
1160 }
1161 for (int i = 0; i < blkState->_stack_height; i++) {
1162 state._stack[i] = blkState->_stack[i];
1163 }
1164 state._stack_height = blkState->_stack_height;
1165 }
1166 iterate_one_block(blk, state, successors);
1167 // if this block has any exception handlers, push them
1168 // onto successor list
1169 if (blk->has_handler()) {
1170 DEBUG_ONLY(int handler_count = 0;)
1171 int blk_start = blk->start_bci();
1172 int blk_end = blk->limit_bci();
1173 for (int i = 0; i < numblocks; i++) {
1174 ciBlock *b = _methodBlocks->block(i);
1175 if (b->is_handler()) {
1176 int ex_start = b->ex_start_bci();
1177 int ex_end = b->ex_limit_bci();
1178 if ((ex_start >= blk_start && ex_start < blk_end) ||
1179 (ex_end > blk_start && ex_end <= blk_end)) {
1180 successors.push(b);
1181 }
1182 DEBUG_ONLY(handler_count++;)
1183 }
1184 }
1185 assert(handler_count > 0, "must find at least one handler");
1186 }
1187 // merge computed variable state with successors
1188 while(successors.length() > 0) {
1189 ciBlock *succ = successors.pop();
1190 merge_block_states(blockstates, succ, &state);
1191 if (!succ->processed())
1192 worklist.push(succ);
1193 }
1194 }
1195 }
1196
1197 void BCEscapeAnalyzer::do_analysis() {
1198 Arena* arena = CURRENT_ENV->arena();
1199 // identify basic blocks
1200 _methodBlocks = _method->get_method_blocks();
1201
1202 iterate_blocks(arena);
1203 }
1204
1205 vmIntrinsicID BCEscapeAnalyzer::known_intrinsic() {
1206 vmIntrinsicID iid = method()->intrinsic_id();
1207 if (iid == vmIntrinsics::_getClass ||
1208 iid == vmIntrinsics::_hashCode) {
1209 return iid;
1210 } else {
1211 return vmIntrinsics::_none;
1212 }
1213 }
1214
1215 void BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsicID iid) {
1216 switch (iid) {
1217 case vmIntrinsics::_getClass:
1218 _return_local = false;
1219 _return_allocated = false;
1220 break;
1221 case vmIntrinsics::_hashCode:
1222 // initialized state is correct
1223 break;
1224 default:
1225 assert(false, "unexpected intrinsic");
1226 }
1227 }
1228
1229 void BCEscapeAnalyzer::initialize() {
1230 int i;
1231
1232 // clear escape information (method may have been deoptimized)
1233 methodData()->clear_escape_info();
1234
1235 // initialize escape state of object parameters
1236 ciSignature* sig = method()->signature();
1237 int j = 0;
1238 if (!method()->is_static()) {
1239 _arg_local.set(0);
1240 _arg_stack.set(0);
1241 j++;
1242 }
1243 for (i = 0; i < sig->count(); i++) {
1244 ciType* t = sig->type_at(i);
1245 if (!t->is_primitive_type()) {
1246 _arg_local.set(j);
1247 _arg_stack.set(j);
1248 }
1249 j += t->size();
1250 }
1251 assert(j == _arg_size, "just checking");
1252
1253 // start with optimistic assumption
1254 ciType *rt = _method->return_type();
1255 if (rt->is_primitive_type()) {
1256 _return_local = false;
1257 _return_allocated = false;
1258 } else {
1259 _return_local = true;
1260 _return_allocated = true;
1261 }
1262 _allocated_escapes = false;
1263 _unknown_modified = false;
1264 }
1265
1266 void BCEscapeAnalyzer::clear_escape_info() {
1267 ciSignature* sig = method()->signature();
1268 int arg_count = sig->count();
1269 ArgumentMap var;
1270 if (!method()->is_static()) {
1271 arg_count++; // allow for "this"
1272 }
1273 for (int i = 0; i < arg_count; i++) {
1274 set_arg_modified(i, OFFSET_ANY, 4);
1275 var.clear();
1276 var.set(i);
1277 set_modified(var, OFFSET_ANY, 4);
1278 set_global_escape(var);
1279 }
1280 _arg_local.clear();
1281 _arg_stack.clear();
1282 _arg_returned.clear();
1283 _return_local = false;
1284 _return_allocated = false;
1285 _allocated_escapes = true;
1286 _unknown_modified = true;
1287 }
1288
1289
1290 void BCEscapeAnalyzer::compute_escape_info() {
1291 int i;
1292 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1293
1294 vmIntrinsicID iid = known_intrinsic();
1295
1296 // check if method can be analyzed
1297 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1298 || _level > MaxBCEAEstimateLevel
1299 || method()->code_size() > MaxBCEAEstimateSize)) {
1300 if (BCEATraceLevel >= 1) {
1301 tty->print("Skipping method because: ");
1302 if (method()->is_abstract())
1303 tty->print_cr("method is abstract.");
1304 else if (method()->is_native())
1305 tty->print_cr("method is native.");
1306 else if (!method()->holder()->is_initialized())
1307 tty->print_cr("class of method is not initialized.");
1308 else if (_level > MaxBCEAEstimateLevel)
1309 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1310 _level, (int) MaxBCEAEstimateLevel);
1311 else if (method()->code_size() > MaxBCEAEstimateSize)
1312 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1313 method()->code_size(), (int) MaxBCEAEstimateSize);
1314 else
1315 ShouldNotReachHere();
1316 }
1317 clear_escape_info();
1318
1319 return;
1320 }
1321
1322 if (BCEATraceLevel >= 1) {
1323 tty->print("[EA] estimating escape information for");
1324 if (iid != vmIntrinsics::_none)
1325 tty->print(" intrinsic");
1326 method()->print_short_name();
1327 tty->print_cr(" (%d bytes)", method()->code_size());
1328 }
1329
1330 initialize();
1331
1332 // Do not scan method if it has no object parameters and
1333 // does not returns an object (_return_allocated is set in initialize()).
1334 if (_arg_local.is_empty() && !_return_allocated) {
1335 // Clear all info since method's bytecode was not analysed and
1336 // set pessimistic escape information.
1337 clear_escape_info();
1338 methodData()->set_eflag(MethodData::allocated_escapes);
1339 methodData()->set_eflag(MethodData::unknown_modified);
1340 methodData()->set_eflag(MethodData::estimated);
1341 return;
1342 }
1343
1344 if (iid != vmIntrinsics::_none)
1345 compute_escape_for_intrinsic(iid);
1346 else {
1347 do_analysis();
1348 }
1349
1350 // don't store interprocedural escape information if it introduces
1351 // dependencies or if method data is empty
1352 //
1353 if (!has_dependencies() && !methodData()->is_empty()) {
1354 for (i = 0; i < _arg_size; i++) {
1355 if (_arg_local.test(i)) {
1356 assert(_arg_stack.test(i), "inconsistent escape info");
1357 methodData()->set_arg_local(i);
1358 methodData()->set_arg_stack(i);
1359 } else if (_arg_stack.test(i)) {
1360 methodData()->set_arg_stack(i);
1361 }
1362 if (_arg_returned.test(i)) {
1363 methodData()->set_arg_returned(i);
1364 }
1365 methodData()->set_arg_modified(i, _arg_modified[i]);
1366 }
1367 if (_return_local) {
1368 methodData()->set_eflag(MethodData::return_local);
1369 }
1370 if (_return_allocated) {
1371 methodData()->set_eflag(MethodData::return_allocated);
1372 }
1373 if (_allocated_escapes) {
1374 methodData()->set_eflag(MethodData::allocated_escapes);
1375 }
1376 if (_unknown_modified) {
1377 methodData()->set_eflag(MethodData::unknown_modified);
1378 }
1379 methodData()->set_eflag(MethodData::estimated);
1380 }
1381 }
1382
1383 void BCEscapeAnalyzer::read_escape_info() {
1384 assert(methodData()->has_escape_info(), "no escape info available");
1385
1386 // read escape information from method descriptor
1387 for (int i = 0; i < _arg_size; i++) {
1388 if (methodData()->is_arg_local(i))
1389 _arg_local.set(i);
1390 if (methodData()->is_arg_stack(i))
1391 _arg_stack.set(i);
1392 if (methodData()->is_arg_returned(i))
1393 _arg_returned.set(i);
1394 _arg_modified[i] = methodData()->arg_modified(i);
1395 }
1396 _return_local = methodData()->eflag_set(MethodData::return_local);
1397 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1398 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1399 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1400
1401 }
1402
1403 #ifndef PRODUCT
1404 void BCEscapeAnalyzer::dump() {
1405 tty->print("[EA] estimated escape information for");
1406 method()->print_short_name();
1407 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1408 tty->print(" non-escaping args: ");
1409 _arg_local.print();
1410 tty->print(" stack-allocatable args: ");
1411 _arg_stack.print();
1412 if (_return_local) {
1413 tty->print(" returned args: ");
1414 _arg_returned.print();
1415 } else if (is_return_allocated()) {
1416 tty->print_cr(" return allocated value");
1417 } else {
1418 tty->print_cr(" return non-local value");
1419 }
1420 tty->print(" modified args: ");
1421 for (int i = 0; i < _arg_size; i++) {
1422 if (_arg_modified[i] == 0)
1423 tty->print(" 0");
1424 else
1425 tty->print(" 0x%x", _arg_modified[i]);
1426 }
1427 tty->cr();
1428 tty->print(" flags: ");
1429 if (_return_allocated)
1430 tty->print(" return_allocated");
1431 if (_allocated_escapes)
1432 tty->print(" allocated_escapes");
1433 if (_unknown_modified)
1434 tty->print(" unknown_modified");
1435 tty->cr();
1436 }
1437 #endif
1438
1439 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1440 : _arena(CURRENT_ENV->arena())
1441 , _conservative(method == nullptr || !EstimateArgEscape)
1442 , _method(method)
1443 , _methodData(method ? method->method_data() : nullptr)
1444 , _arg_size(method ? method->arg_size() : 0)
1445 , _arg_local(_arena)
1446 , _arg_stack(_arena)
1447 , _arg_returned(_arena)
1448 , _return_local(false)
1449 , _return_allocated(false)
1450 , _allocated_escapes(false)
1451 , _unknown_modified(false)
1452 , _dependencies(_arena, 4, 0, nullptr)
1453 , _parent(parent)
1454 , _level(parent == nullptr ? 0 : parent->level() + 1) {
1455 if (!_conservative) {
1456 _arg_local.clear();
1457 _arg_stack.clear();
1458 _arg_returned.clear();
1459 Arena* arena = CURRENT_ENV->arena();
1460 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1461 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1462
1463 if (methodData() == nullptr)
1464 return;
1465 if (methodData()->has_escape_info()) {
1466 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1467 method->holder()->name()->as_utf8(),
1468 method->name()->as_utf8()));
1469 read_escape_info();
1470 } else {
1471 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1472 method->holder()->name()->as_utf8(),
1473 method->name()->as_utf8()));
1474
1475 compute_escape_info();
1476 methodData()->update_escape_info();
1477 }
1478 #ifndef PRODUCT
1479 if (BCEATraceLevel >= 3) {
1480 // dump escape information
1481 dump();
1482 }
1483 #endif
1484 }
1485 }
1486
1487 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1488 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1489 // Also record evol dependencies so redefinition of the
1490 // callee will trigger recompilation.
1491 deps->assert_evol_method(method());
1492 }
1493 for (int i = 0; i < _dependencies.length(); i+=4) {
1494 ciKlass* recv_klass = _dependencies.at(i+0)->as_klass();
1495 ciMethod* target = _dependencies.at(i+1)->as_method();
1496 ciKlass* resolved_klass = _dependencies.at(i+2)->as_klass();
1497 ciMethod* resolved_method = _dependencies.at(i+3)->as_method();
1498 deps->assert_unique_concrete_method(recv_klass, target, resolved_klass, resolved_method);
1499 }
1500 }