1 /*
2 * Copyright (c) 2005, 2023, 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 "classfile/vmIntrinsics.hpp"
27 #include "ci/bcEscapeAnalyzer.hpp"
28 #include "ci/ciConstant.hpp"
29 #include "ci/ciField.hpp"
30 #include "ci/ciMethodBlocks.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "compiler/compiler_globals.hpp"
33 #include "interpreter/bytecode.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "utilities/align.hpp"
36 #include "utilities/bitMap.inline.hpp"
37 #include "utilities/copy.hpp"
38
39 #ifndef PRODUCT
40 #define TRACE_BCEA(level, code) \
41 if (EstimateArgEscape && BCEATraceLevel >= level) { \
42 code; \
43 }
44 #else
45 #define TRACE_BCEA(level, code)
46 #endif
47
48 // Maintain a map of which arguments a local variable or
49 // stack slot may contain. In addition to tracking
50 // arguments, it tracks two special values, "allocated"
51 // which represents any object allocated in the current
52 // method, and "unknown" which is any other object.
53 // Up to 30 arguments are handled, with the last one
54 // representing summary information for any extra arguments
55 class BCEscapeAnalyzer::ArgumentMap {
56 uint _bits;
57 enum {MAXBIT = 29,
58 ALLOCATED = 1,
59 UNKNOWN = 2};
60
61 uint int_to_bit(uint e) const {
62 if (e > MAXBIT)
63 e = MAXBIT;
64 return (1 << (e + 2));
65 }
66
67 public:
68 ArgumentMap() { _bits = 0;}
69 void set_bits(uint bits) { _bits = bits;}
70 uint get_bits() const { return _bits;}
71 void clear() { _bits = 0;}
72 void set_all() { _bits = ~0u; }
73 bool is_empty() const { return _bits == 0; }
74 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
75 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
76 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
77 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
78 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
79 void set(uint var) { _bits = int_to_bit(var); }
80 void add(uint var) { _bits |= int_to_bit(var); }
81 void add_unknown() { _bits = UNKNOWN; }
82 void add_allocated() { _bits = ALLOCATED; }
83 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
84 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
85 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
86 bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
87 };
88
89 class BCEscapeAnalyzer::StateInfo {
90 public:
91 ArgumentMap *_vars;
92 ArgumentMap *_stack;
93 int _stack_height;
94 int _max_stack;
95 bool _initialized;
96 ArgumentMap empty_map;
97
98 StateInfo() {
99 empty_map.clear();
100 }
101
102 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
103 ArgumentMap apop() { return raw_pop(); }
104 void spop() { raw_pop(); }
105 void lpop() { spop(); spop(); }
106 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
107 void apush(ArgumentMap i) { raw_push(i); }
108 void spush() { raw_push(empty_map); }
109 void lpush() { spush(); spush(); }
110
111 };
112
113 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
114 for (int i = 0; i < _arg_size; i++) {
115 if (vars.contains(i))
116 _arg_returned.set(i);
117 }
118 _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
119 _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
120 }
121
122 // return true if any element of vars is an argument
123 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
124 for (int i = 0; i < _arg_size; i++) {
125 if (vars.contains(i))
126 return true;
127 }
128 return false;
129 }
130
131 // return true if any element of vars is an arg_stack argument
132 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
133 if (_conservative)
134 return true;
135 for (int i = 0; i < _arg_size; i++) {
136 if (vars.contains(i) && _arg_stack.test(i))
137 return true;
138 }
139 return false;
140 }
141
142 // return true if all argument elements of vars are returned
143 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
144 for (int i = 0; i < _arg_size; i++) {
145 if (vars.contains(i) && !_arg_returned.test(i)) {
146 return false;
147 }
148 }
149 return true;
150 }
151
152 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
153 for (int i = 0; i < _arg_size; i++) {
154 if (vars.contains(i)) {
155 bm.remove(i);
156 }
157 }
158 }
159
160 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
161 clear_bits(vars, _arg_local);
162 if (vars.contains_allocated()) {
163 _allocated_escapes = true;
164 }
165 }
166
167 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
168 clear_bits(vars, _arg_local);
169 clear_bits(vars, _arg_stack);
170 if (vars.contains_allocated())
171 _allocated_escapes = true;
172
173 if (merge && !vars.is_empty()) {
174 // Merge new state into already processed block.
175 // New state is not taken into account and
176 // it may invalidate set_returned() result.
177 if (vars.contains_unknown() || vars.contains_allocated()) {
178 _return_local = false;
179 }
180 if (vars.contains_unknown() || vars.contains_vars()) {
181 _return_allocated = false;
182 }
183 if (_return_local && vars.contains_vars() && !returns_all(vars)) {
184 // Return result should be invalidated if args in new
185 // state are not recorded in return state.
186 _return_local = false;
187 }
188 }
189 }
190
191 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
192
193 for (int i = 0; i < _arg_size; i++) {
194 if (vars.contains(i)) {
195 set_arg_modified(i, offs, size);
196 }
197 }
198 if (vars.contains_unknown())
199 _unknown_modified = true;
200 }
201
202 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
203 for (BCEscapeAnalyzer* scope = this; scope != nullptr; scope = scope->_parent) {
204 if (scope->method() == callee) {
205 return true;
206 }
207 }
208 return false;
209 }
210
211 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
212 if (offset == OFFSET_ANY)
213 return _arg_modified[arg] != 0;
214 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
215 bool modified = false;
216 int l = offset / HeapWordSize;
217 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
218 if (l > ARG_OFFSET_MAX)
219 l = ARG_OFFSET_MAX;
220 if (h > ARG_OFFSET_MAX+1)
221 h = ARG_OFFSET_MAX + 1;
222 for (int i = l; i < h; i++) {
223 modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
224 }
225 return modified;
226 }
227
228 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
229 if (offset == OFFSET_ANY) {
230 _arg_modified[arg] = (uint) -1;
231 return;
232 }
233 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
234 int l = offset / HeapWordSize;
235 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
236 if (l > ARG_OFFSET_MAX)
237 l = ARG_OFFSET_MAX;
238 if (h > ARG_OFFSET_MAX+1)
239 h = ARG_OFFSET_MAX + 1;
240 for (int i = l; i < h; i++) {
241 _arg_modified[arg] |= (1 << i);
242 }
243 }
244
245 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
246 int i;
247
248 // retrieve information about the callee
249 ciInstanceKlass* klass = target->holder();
250 ciInstanceKlass* calling_klass = method()->holder();
251 ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
252 ciInstanceKlass* actual_recv = callee_holder;
253
254 // Some methods are obviously bindable without any type checks so
255 // convert them directly to an invokespecial or invokestatic.
256 if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
257 switch (code) {
258 case Bytecodes::_invokevirtual:
259 code = Bytecodes::_invokespecial;
260 break;
261 case Bytecodes::_invokehandle:
262 code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
263 break;
264 default:
265 break;
266 }
267 }
268
269 // compute size of arguments
270 int arg_size = target->invoke_arg_size(code);
271 int arg_base = MAX2(state._stack_height - arg_size, 0);
272
273 // direct recursive calls are skipped if they can be bound statically without introducing
274 // dependencies and if parameters are passed at the same position as in the current method
275 // other calls are skipped if there are no non-escaped arguments passed to them
276 bool directly_recursive = (method() == target) &&
277 (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
278
279 // check if analysis of callee can safely be skipped
280 bool skip_callee = true;
281 for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
282 ArgumentMap arg = state._stack[i];
283 skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
284 }
285 // For now we conservatively skip invokedynamic.
286 if (code == Bytecodes::_invokedynamic) {
287 skip_callee = true;
288 }
289 if (skip_callee) {
290 TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
291 for (i = 0; i < arg_size; i++) {
292 set_method_escape(state.raw_pop());
293 }
294 _unknown_modified = true; // assume the worst since we don't analyze the called method
295 return;
296 }
297
298 // determine actual method (use CHA if necessary)
299 ciMethod* inline_target = nullptr;
300 if (target->is_loaded() && klass->is_loaded()
301 && (klass->is_initialized() || (klass->is_interface() && target->holder()->is_initialized()))) {
302 if (code == Bytecodes::_invokestatic
303 || code == Bytecodes::_invokespecial
304 || (code == Bytecodes::_invokevirtual && target->is_final_method())) {
305 inline_target = target;
306 } else {
307 inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
308 }
309 }
310
311 if (inline_target != nullptr && !is_recursive_call(inline_target)) {
312 // analyze callee
313 BCEscapeAnalyzer analyzer(inline_target, this);
314
315 // adjust escape state of actual parameters
316 bool must_record_dependencies = false;
317 for (i = arg_size - 1; i >= 0; i--) {
318 ArgumentMap arg = state.raw_pop();
319 // Check if callee arg is a caller arg or an allocated object
320 bool allocated = arg.contains_allocated();
321 if (!(is_argument(arg) || allocated))
322 continue;
323 for (int j = 0; j < _arg_size; j++) {
324 if (arg.contains(j)) {
325 _arg_modified[j] |= analyzer._arg_modified[i];
326 }
327 }
328 if (!(is_arg_stack(arg) || allocated)) {
329 // arguments have already been recognized as escaping
330 } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
331 set_method_escape(arg);
332 must_record_dependencies = true;
333 } else {
334 set_global_escape(arg);
335 }
336 }
337 _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
338
339 // record dependencies if at least one parameter retained stack-allocatable
340 if (must_record_dependencies) {
341 if (code == Bytecodes::_invokeinterface ||
342 (code == Bytecodes::_invokevirtual && !target->is_final_method())) {
343 _dependencies.append(actual_recv);
344 _dependencies.append(inline_target);
345 _dependencies.append(callee_holder);
346 _dependencies.append(target);
347 assert(callee_holder->is_interface() == (code == Bytecodes::_invokeinterface), "sanity");
348 }
349 _dependencies.appendAll(analyzer.dependencies());
350 }
351 } else {
352 TRACE_BCEA(1, tty->print_cr("[EA] virtual method %s is not monomorphic.",
353 target->name()->as_utf8()));
354 // conservatively mark all actual parameters as escaping globally
355 for (i = 0; i < arg_size; i++) {
356 ArgumentMap arg = state.raw_pop();
357 if (!is_argument(arg))
358 continue;
359 set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
360 set_global_escape(arg);
361 }
362 _unknown_modified = true; // assume the worst since we don't know the called method
363 }
364 }
365
366 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
367 return ((~arg_set1) | arg_set2) == 0;
368 }
369
370
371 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
372
373 blk->set_processed();
374 ciBytecodeStream s(method());
375 int limit_bci = blk->limit_bci();
376 bool fall_through = false;
377 ArgumentMap allocated_obj;
378 allocated_obj.add_allocated();
379 ArgumentMap unknown_obj;
380 unknown_obj.add_unknown();
381 ArgumentMap empty_map;
382
383 s.reset_to_bci(blk->start_bci());
384 while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
385 fall_through = true;
386 switch (s.cur_bc()) {
387 case Bytecodes::_nop:
388 break;
389 case Bytecodes::_aconst_null:
390 state.apush(unknown_obj);
391 break;
392 case Bytecodes::_iconst_m1:
393 case Bytecodes::_iconst_0:
394 case Bytecodes::_iconst_1:
395 case Bytecodes::_iconst_2:
396 case Bytecodes::_iconst_3:
397 case Bytecodes::_iconst_4:
398 case Bytecodes::_iconst_5:
399 case Bytecodes::_fconst_0:
400 case Bytecodes::_fconst_1:
401 case Bytecodes::_fconst_2:
402 case Bytecodes::_bipush:
403 case Bytecodes::_sipush:
404 state.spush();
405 break;
406 case Bytecodes::_lconst_0:
407 case Bytecodes::_lconst_1:
408 case Bytecodes::_dconst_0:
409 case Bytecodes::_dconst_1:
410 state.lpush();
411 break;
412 case Bytecodes::_ldc:
413 case Bytecodes::_ldc_w:
414 case Bytecodes::_ldc2_w:
415 {
416 // Avoid calling get_constant() which will try to allocate
417 // unloaded constant. We need only constant's type.
418 int index = s.get_constant_pool_index();
419 BasicType con_bt = s.get_basic_type_for_constant_at(index);
420 if (con_bt == T_LONG || con_bt == T_DOUBLE) {
421 // Only longs and doubles use 2 stack slots.
422 state.lpush();
423 } else if (con_bt == 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 }
490 break;
491 case Bytecodes::_istore:
492 case Bytecodes::_fstore:
493 case Bytecodes::_istore_0:
494 case Bytecodes::_istore_1:
495 case Bytecodes::_istore_2:
496 case Bytecodes::_istore_3:
497 case Bytecodes::_fstore_0:
498 case Bytecodes::_fstore_1:
499 case Bytecodes::_fstore_2:
500 case Bytecodes::_fstore_3:
501 state.spop();
502 break;
503 case Bytecodes::_lstore:
504 case Bytecodes::_dstore:
505 case Bytecodes::_lstore_0:
506 case Bytecodes::_lstore_1:
507 case Bytecodes::_lstore_2:
508 case Bytecodes::_lstore_3:
509 case Bytecodes::_dstore_0:
510 case Bytecodes::_dstore_1:
511 case Bytecodes::_dstore_2:
512 case Bytecodes::_dstore_3:
513 state.lpop();
514 break;
515 case Bytecodes::_astore:
516 state._vars[s.get_index()] = state.apop();
517 break;
518 case Bytecodes::_astore_0:
519 state._vars[0] = state.apop();
520 break;
521 case Bytecodes::_astore_1:
522 state._vars[1] = state.apop();
523 break;
524 case Bytecodes::_astore_2:
525 state._vars[2] = state.apop();
526 break;
527 case Bytecodes::_astore_3:
528 state._vars[3] = state.apop();
529 break;
530 case Bytecodes::_iastore:
531 case Bytecodes::_fastore:
532 case Bytecodes::_bastore:
533 case Bytecodes::_castore:
534 case Bytecodes::_sastore:
535 {
536 state.spop();
537 state.spop();
538 ArgumentMap arr = state.apop();
539 set_method_escape(arr);
540 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
541 break;
542 }
543 case Bytecodes::_lastore:
544 case Bytecodes::_dastore:
545 {
546 state.lpop();
547 state.spop();
548 ArgumentMap arr = state.apop();
549 set_method_escape(arr);
550 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
551 break;
552 }
553 case Bytecodes::_aastore:
554 {
555 set_global_escape(state.apop());
556 state.spop();
557 ArgumentMap arr = state.apop();
558 // If the array is a flat array, a larger part of it is modified than
559 // the size of a reference. However, if OFFSET_ANY is given as
560 // parameter to set_modified(), size is not taken into account.
561 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
562 break;
563 }
564 case Bytecodes::_pop:
565 state.raw_pop();
566 break;
567 case Bytecodes::_pop2:
568 state.raw_pop();
569 state.raw_pop();
570 break;
571 case Bytecodes::_dup:
572 { ArgumentMap w1 = state.raw_pop();
573 state.raw_push(w1);
574 state.raw_push(w1);
575 }
576 break;
577 case Bytecodes::_dup_x1:
578 { ArgumentMap w1 = state.raw_pop();
579 ArgumentMap w2 = state.raw_pop();
580 state.raw_push(w1);
581 state.raw_push(w2);
582 state.raw_push(w1);
583 }
584 break;
585 case Bytecodes::_dup_x2:
586 { ArgumentMap w1 = state.raw_pop();
587 ArgumentMap w2 = state.raw_pop();
588 ArgumentMap w3 = state.raw_pop();
589 state.raw_push(w1);
590 state.raw_push(w3);
591 state.raw_push(w2);
592 state.raw_push(w1);
593 }
594 break;
595 case Bytecodes::_dup2:
596 { ArgumentMap w1 = state.raw_pop();
597 ArgumentMap w2 = state.raw_pop();
598 state.raw_push(w2);
599 state.raw_push(w1);
600 state.raw_push(w2);
601 state.raw_push(w1);
602 }
603 break;
604 case Bytecodes::_dup2_x1:
605 { ArgumentMap w1 = state.raw_pop();
606 ArgumentMap w2 = state.raw_pop();
607 ArgumentMap w3 = state.raw_pop();
608 state.raw_push(w2);
609 state.raw_push(w1);
610 state.raw_push(w3);
611 state.raw_push(w2);
612 state.raw_push(w1);
613 }
614 break;
615 case Bytecodes::_dup2_x2:
616 { ArgumentMap w1 = state.raw_pop();
617 ArgumentMap w2 = state.raw_pop();
618 ArgumentMap w3 = state.raw_pop();
619 ArgumentMap w4 = state.raw_pop();
620 state.raw_push(w2);
621 state.raw_push(w1);
622 state.raw_push(w4);
623 state.raw_push(w3);
624 state.raw_push(w2);
625 state.raw_push(w1);
626 }
627 break;
628 case Bytecodes::_swap:
629 { ArgumentMap w1 = state.raw_pop();
630 ArgumentMap w2 = state.raw_pop();
631 state.raw_push(w1);
632 state.raw_push(w2);
633 }
634 break;
635 case Bytecodes::_iadd:
636 case Bytecodes::_fadd:
637 case Bytecodes::_isub:
638 case Bytecodes::_fsub:
639 case Bytecodes::_imul:
640 case Bytecodes::_fmul:
641 case Bytecodes::_idiv:
642 case Bytecodes::_fdiv:
643 case Bytecodes::_irem:
644 case Bytecodes::_frem:
645 case Bytecodes::_iand:
646 case Bytecodes::_ior:
647 case Bytecodes::_ixor:
648 state.spop();
649 state.spop();
650 state.spush();
651 break;
652 case Bytecodes::_ladd:
653 case Bytecodes::_dadd:
654 case Bytecodes::_lsub:
655 case Bytecodes::_dsub:
656 case Bytecodes::_lmul:
657 case Bytecodes::_dmul:
658 case Bytecodes::_ldiv:
659 case Bytecodes::_ddiv:
660 case Bytecodes::_lrem:
661 case Bytecodes::_drem:
662 case Bytecodes::_land:
663 case Bytecodes::_lor:
664 case Bytecodes::_lxor:
665 state.lpop();
666 state.lpop();
667 state.lpush();
668 break;
669 case Bytecodes::_ishl:
670 case Bytecodes::_ishr:
671 case Bytecodes::_iushr:
672 state.spop();
673 state.spop();
674 state.spush();
675 break;
676 case Bytecodes::_lshl:
677 case Bytecodes::_lshr:
678 case Bytecodes::_lushr:
679 state.spop();
680 state.lpop();
681 state.lpush();
682 break;
683 case Bytecodes::_ineg:
684 case Bytecodes::_fneg:
685 state.spop();
686 state.spush();
687 break;
688 case Bytecodes::_lneg:
689 case Bytecodes::_dneg:
690 state.lpop();
691 state.lpush();
692 break;
693 case Bytecodes::_iinc:
694 break;
695 case Bytecodes::_i2l:
696 case Bytecodes::_i2d:
697 case Bytecodes::_f2l:
698 case Bytecodes::_f2d:
699 state.spop();
700 state.lpush();
701 break;
702 case Bytecodes::_i2f:
703 case Bytecodes::_f2i:
704 state.spop();
705 state.spush();
706 break;
707 case Bytecodes::_l2i:
708 case Bytecodes::_l2f:
709 case Bytecodes::_d2i:
710 case Bytecodes::_d2f:
711 state.lpop();
712 state.spush();
713 break;
714 case Bytecodes::_l2d:
715 case Bytecodes::_d2l:
716 state.lpop();
717 state.lpush();
718 break;
719 case Bytecodes::_i2b:
720 case Bytecodes::_i2c:
721 case Bytecodes::_i2s:
722 state.spop();
723 state.spush();
724 break;
725 case Bytecodes::_lcmp:
726 case Bytecodes::_dcmpl:
727 case Bytecodes::_dcmpg:
728 state.lpop();
729 state.lpop();
730 state.spush();
731 break;
732 case Bytecodes::_fcmpl:
733 case Bytecodes::_fcmpg:
734 state.spop();
735 state.spop();
736 state.spush();
737 break;
738 case Bytecodes::_ifeq:
739 case Bytecodes::_ifne:
740 case Bytecodes::_iflt:
741 case Bytecodes::_ifge:
742 case Bytecodes::_ifgt:
743 case Bytecodes::_ifle:
744 {
745 state.spop();
746 int dest_bci = s.get_dest();
747 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
748 assert(s.next_bci() == limit_bci, "branch must end block");
749 successors.push(_methodBlocks->block_containing(dest_bci));
750 break;
751 }
752 case Bytecodes::_if_icmpeq:
753 case Bytecodes::_if_icmpne:
754 case Bytecodes::_if_icmplt:
755 case Bytecodes::_if_icmpge:
756 case Bytecodes::_if_icmpgt:
757 case Bytecodes::_if_icmple:
758 {
759 state.spop();
760 state.spop();
761 int dest_bci = s.get_dest();
762 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
763 assert(s.next_bci() == limit_bci, "branch must end block");
764 successors.push(_methodBlocks->block_containing(dest_bci));
765 break;
766 }
767 case Bytecodes::_if_acmpeq:
768 case Bytecodes::_if_acmpne:
769 {
770 set_method_escape(state.apop());
771 set_method_escape(state.apop());
772 int dest_bci = s.get_dest();
773 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
774 assert(s.next_bci() == limit_bci, "branch must end block");
775 successors.push(_methodBlocks->block_containing(dest_bci));
776 break;
777 }
778 case Bytecodes::_goto:
779 {
780 int dest_bci = s.get_dest();
781 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
782 assert(s.next_bci() == limit_bci, "branch must end block");
783 successors.push(_methodBlocks->block_containing(dest_bci));
784 fall_through = false;
785 break;
786 }
787 case Bytecodes::_jsr:
788 {
789 int dest_bci = s.get_dest();
790 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
791 assert(s.next_bci() == limit_bci, "branch must end block");
792 state.apush(empty_map);
793 successors.push(_methodBlocks->block_containing(dest_bci));
794 fall_through = false;
795 break;
796 }
797 case Bytecodes::_ret:
798 // we don't track the destination of a "ret" instruction
799 assert(s.next_bci() == limit_bci, "branch must end block");
800 fall_through = false;
801 break;
802 case Bytecodes::_return:
803 assert(s.next_bci() == limit_bci, "return must end block");
804 fall_through = false;
805 break;
806 case Bytecodes::_tableswitch:
807 {
808 state.spop();
809 Bytecode_tableswitch sw(&s);
810 int len = sw.length();
811 int dest_bci;
812 for (int i = 0; i < len; i++) {
813 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
814 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
815 successors.push(_methodBlocks->block_containing(dest_bci));
816 }
817 dest_bci = s.cur_bci() + sw.default_offset();
818 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
819 successors.push(_methodBlocks->block_containing(dest_bci));
820 assert(s.next_bci() == limit_bci, "branch must end block");
821 fall_through = false;
822 break;
823 }
824 case Bytecodes::_lookupswitch:
825 {
826 state.spop();
827 Bytecode_lookupswitch sw(&s);
828 int len = sw.number_of_pairs();
829 int dest_bci;
830 for (int i = 0; i < len; i++) {
831 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
832 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
833 successors.push(_methodBlocks->block_containing(dest_bci));
834 }
835 dest_bci = s.cur_bci() + sw.default_offset();
836 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
837 successors.push(_methodBlocks->block_containing(dest_bci));
838 fall_through = false;
839 break;
840 }
841 case Bytecodes::_ireturn:
842 case Bytecodes::_freturn:
843 state.spop();
844 fall_through = false;
845 break;
846 case Bytecodes::_lreturn:
847 case Bytecodes::_dreturn:
848 state.lpop();
849 fall_through = false;
850 break;
851 case Bytecodes::_areturn:
852 set_returned(state.apop());
853 fall_through = false;
854 break;
855 case Bytecodes::_getstatic:
856 case Bytecodes::_getfield:
857 { bool ignored_will_link;
858 ciField* field = s.get_field(ignored_will_link);
859 BasicType field_type = field->type()->basic_type();
860 if (s.cur_bc() != Bytecodes::_getstatic) {
861 set_method_escape(state.apop());
862 }
863 if (is_reference_type(field_type)) {
864 state.apush(unknown_obj);
865 } else if (type2size[field_type] == 1) {
866 state.spush();
867 } else {
868 state.lpush();
869 }
870 }
871 break;
872 case Bytecodes::_putstatic:
873 case Bytecodes::_putfield:
874 { bool will_link;
875 ciField* field = s.get_field(will_link);
876 BasicType field_type = field->type()->basic_type();
877 if (is_reference_type(field_type)) {
878 set_global_escape(state.apop());
879 } else if (type2size[field_type] == 1) {
880 state.spop();
881 } else {
882 state.lpop();
883 }
884 if (s.cur_bc() != Bytecodes::_putstatic) {
885 ArgumentMap p = state.apop();
886 set_method_escape(p);
887 set_modified(p, will_link ? field->offset_in_bytes() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
888 }
889 }
890 break;
891 case Bytecodes::_invokevirtual:
892 case Bytecodes::_invokespecial:
893 case Bytecodes::_invokestatic:
894 case Bytecodes::_invokedynamic:
895 case Bytecodes::_invokeinterface:
896 { bool ignored_will_link;
897 ciSignature* declared_signature = nullptr;
898 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
899 ciKlass* holder = s.get_declared_method_holder();
900 assert(declared_signature != nullptr, "cannot be null");
901 // If the current bytecode has an attached appendix argument,
902 // push an unknown object to represent that argument. (Analysis
903 // of dynamic call sites, especially invokehandle calls, needs
904 // the appendix argument on the stack, in addition to "regular" arguments
905 // pushed onto the stack by bytecode instructions preceding the call.)
906 //
907 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
908 // method to determine whether the current bytecode has an appendix argument.
909 // The has_appendix() method obtains the appendix from the
910 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
911 // resolution of dynamic call sites. Callees in the
912 // ciBytecodeStream::get_method() call above also access the _f1 field;
913 // interleaving the get_method() and has_appendix() calls in the current
914 // method with call site resolution can lead to an inconsistent view of
915 // the current method's argument count. In particular, some interleaving(s)
916 // can cause the method's argument count to not include the appendix, which
917 // then leads to stack over-/underflow in the escape analyzer.
918 //
919 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
920 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
921 // instructions, except if the call site is the _invokeBasic intrinsic
922 // (that intrinsic is always targeted by an invokehandle instruction but does
923 // not have an appendix argument).
924 if (target->is_loaded() &&
925 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
926 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
927 state.apush(unknown_obj);
928 }
929 // Pass in raw bytecode because we need to see invokehandle instructions.
930 invoke(state, s.cur_bc_raw(), target, holder);
931 // We are using the return type of the declared signature here because
932 // it might be a more concrete type than the one from the target (for
933 // e.g. invokedynamic and invokehandle).
934 ciType* return_type = declared_signature->return_type();
935 if (!return_type->is_primitive_type()) {
936 state.apush(unknown_obj);
937 } else if (return_type->is_one_word()) {
938 state.spush();
939 } else if (return_type->is_two_word()) {
940 state.lpush();
941 }
942 }
943 break;
944 case Bytecodes::_new:
945 state.apush(allocated_obj);
946 break;
947 case Bytecodes::_newarray:
948 case Bytecodes::_anewarray:
949 state.spop();
950 state.apush(allocated_obj);
951 break;
952 case Bytecodes::_multianewarray:
953 { int i = s.cur_bcp()[3];
954 while (i-- > 0) state.spop();
955 state.apush(allocated_obj);
956 }
957 break;
958 case Bytecodes::_arraylength:
959 set_method_escape(state.apop());
960 state.spush();
961 break;
962 case Bytecodes::_athrow:
963 set_global_escape(state.apop());
964 fall_through = false;
965 break;
966 case Bytecodes::_checkcast:
967 { ArgumentMap obj = state.apop();
968 set_method_escape(obj);
969 state.apush(obj);
970 }
971 break;
972 case Bytecodes::_instanceof:
973 set_method_escape(state.apop());
974 state.spush();
975 break;
976 case Bytecodes::_monitorenter:
977 case Bytecodes::_monitorexit:
978 state.apop();
979 break;
980 case Bytecodes::_wide:
981 ShouldNotReachHere();
982 break;
983 case Bytecodes::_ifnull:
984 case Bytecodes::_ifnonnull:
985 {
986 set_method_escape(state.apop());
987 int dest_bci = s.get_dest();
988 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
989 assert(s.next_bci() == limit_bci, "branch must end block");
990 successors.push(_methodBlocks->block_containing(dest_bci));
991 break;
992 }
993 case Bytecodes::_goto_w:
994 {
995 int dest_bci = s.get_far_dest();
996 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
997 assert(s.next_bci() == limit_bci, "branch must end block");
998 successors.push(_methodBlocks->block_containing(dest_bci));
999 fall_through = false;
1000 break;
1001 }
1002 case Bytecodes::_jsr_w:
1003 {
1004 int dest_bci = s.get_far_dest();
1005 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1006 assert(s.next_bci() == limit_bci, "branch must end block");
1007 state.apush(empty_map);
1008 successors.push(_methodBlocks->block_containing(dest_bci));
1009 fall_through = false;
1010 break;
1011 }
1012 case Bytecodes::_breakpoint:
1013 break;
1014 default:
1015 ShouldNotReachHere();
1016 break;
1017 }
1018
1019 }
1020 if (fall_through) {
1021 int fall_through_bci = s.cur_bci();
1022 if (fall_through_bci < _method->code_size()) {
1023 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1024 successors.push(_methodBlocks->block_containing(fall_through_bci));
1025 }
1026 }
1027 }
1028
1029 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1030 StateInfo *d_state = blockstates + dest->index();
1031 int nlocals = _method->max_locals();
1032
1033 // exceptions may cause transfer of control to handlers in the middle of a
1034 // block, so we don't merge the incoming state of exception handlers
1035 if (dest->is_handler())
1036 return;
1037 if (!d_state->_initialized ) {
1038 // destination not initialized, just copy
1039 for (int i = 0; i < nlocals; i++) {
1040 d_state->_vars[i] = s_state->_vars[i];
1041 }
1042 for (int i = 0; i < s_state->_stack_height; i++) {
1043 d_state->_stack[i] = s_state->_stack[i];
1044 }
1045 d_state->_stack_height = s_state->_stack_height;
1046 d_state->_max_stack = s_state->_max_stack;
1047 d_state->_initialized = true;
1048 } else if (!dest->processed()) {
1049 // we have not yet walked the bytecodes of dest, we can merge
1050 // the states
1051 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1052 for (int i = 0; i < nlocals; i++) {
1053 d_state->_vars[i].set_union(s_state->_vars[i]);
1054 }
1055 for (int i = 0; i < s_state->_stack_height; i++) {
1056 d_state->_stack[i].set_union(s_state->_stack[i]);
1057 }
1058 } else {
1059 // the bytecodes of dest have already been processed, mark any
1060 // arguments in the source state which are not in the dest state
1061 // as global escape.
1062 // Future refinement: we only need to mark these variable to the
1063 // maximum escape of any variables in dest state
1064 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1065 ArgumentMap extra_vars;
1066 for (int i = 0; i < nlocals; i++) {
1067 ArgumentMap t;
1068 t = s_state->_vars[i];
1069 t.set_difference(d_state->_vars[i]);
1070 extra_vars.set_union(t);
1071 }
1072 for (int i = 0; i < s_state->_stack_height; i++) {
1073 ArgumentMap t;
1074 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1075 t.clear();
1076 t = s_state->_stack[i];
1077 t.set_difference(d_state->_stack[i]);
1078 extra_vars.set_union(t);
1079 }
1080 set_global_escape(extra_vars, true);
1081 }
1082 }
1083
1084 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1085 int numblocks = _methodBlocks->num_blocks();
1086 int stkSize = _method->max_stack();
1087 int numLocals = _method->max_locals();
1088 StateInfo state;
1089
1090 int datacount = (numblocks + 1) * (stkSize + numLocals);
1091 int datasize = datacount * sizeof(ArgumentMap);
1092 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1093 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1094 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1095 ArgumentMap *dp = statedata;
1096 state._vars = dp;
1097 dp += numLocals;
1098 state._stack = dp;
1099 dp += stkSize;
1100 state._initialized = false;
1101 state._max_stack = stkSize;
1102 for (int i = 0; i < numblocks; i++) {
1103 blockstates[i]._vars = dp;
1104 dp += numLocals;
1105 blockstates[i]._stack = dp;
1106 dp += stkSize;
1107 blockstates[i]._initialized = false;
1108 blockstates[i]._stack_height = 0;
1109 blockstates[i]._max_stack = stkSize;
1110 }
1111 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, nullptr);
1112 GrowableArray<ciBlock *> successors(arena, 4, 0, nullptr);
1113
1114 _methodBlocks->clear_processed();
1115
1116 // initialize block 0 state from method signature
1117 ArgumentMap allVars; // all oop arguments to method
1118 ciSignature* sig = method()->signature();
1119 int j = 0;
1120 ciBlock* first_blk = _methodBlocks->block_containing(0);
1121 int fb_i = first_blk->index();
1122 if (!method()->is_static()) {
1123 // record information for "this"
1124 blockstates[fb_i]._vars[j].set(j);
1125 allVars.add(j);
1126 j++;
1127 }
1128 for (int i = 0; i < sig->count(); i++) {
1129 ciType* t = sig->type_at(i);
1130 if (!t->is_primitive_type()) {
1131 blockstates[fb_i]._vars[j].set(j);
1132 allVars.add(j);
1133 }
1134 j += t->size();
1135 }
1136 blockstates[fb_i]._initialized = true;
1137 assert(j == _arg_size, "just checking");
1138
1139 ArgumentMap unknown_map;
1140 unknown_map.add_unknown();
1141
1142 worklist.push(first_blk);
1143 while(worklist.length() > 0) {
1144 ciBlock *blk = worklist.pop();
1145 StateInfo *blkState = blockstates + blk->index();
1146 if (blk->is_handler() || blk->is_ret_target()) {
1147 // for an exception handler or a target of a ret instruction, we assume the worst case,
1148 // that any variable could contain any argument
1149 for (int i = 0; i < numLocals; i++) {
1150 state._vars[i] = allVars;
1151 }
1152 if (blk->is_handler()) {
1153 state._stack_height = 1;
1154 } else {
1155 state._stack_height = blkState->_stack_height;
1156 }
1157 for (int i = 0; i < state._stack_height; i++) {
1158 // ??? should this be unknown_map ???
1159 state._stack[i] = allVars;
1160 }
1161 } else {
1162 for (int i = 0; i < numLocals; i++) {
1163 state._vars[i] = blkState->_vars[i];
1164 }
1165 for (int i = 0; i < blkState->_stack_height; i++) {
1166 state._stack[i] = blkState->_stack[i];
1167 }
1168 state._stack_height = blkState->_stack_height;
1169 }
1170 iterate_one_block(blk, state, successors);
1171 // if this block has any exception handlers, push them
1172 // onto successor list
1173 if (blk->has_handler()) {
1174 DEBUG_ONLY(int handler_count = 0;)
1175 int blk_start = blk->start_bci();
1176 int blk_end = blk->limit_bci();
1177 for (int i = 0; i < numblocks; i++) {
1178 ciBlock *b = _methodBlocks->block(i);
1179 if (b->is_handler()) {
1180 int ex_start = b->ex_start_bci();
1181 int ex_end = b->ex_limit_bci();
1182 if ((ex_start >= blk_start && ex_start < blk_end) ||
1183 (ex_end > blk_start && ex_end <= blk_end)) {
1184 successors.push(b);
1185 }
1186 DEBUG_ONLY(handler_count++;)
1187 }
1188 }
1189 assert(handler_count > 0, "must find at least one handler");
1190 }
1191 // merge computed variable state with successors
1192 while(successors.length() > 0) {
1193 ciBlock *succ = successors.pop();
1194 merge_block_states(blockstates, succ, &state);
1195 if (!succ->processed())
1196 worklist.push(succ);
1197 }
1198 }
1199 }
1200
1201 void BCEscapeAnalyzer::do_analysis() {
1202 Arena* arena = CURRENT_ENV->arena();
1203 // identify basic blocks
1204 _methodBlocks = _method->get_method_blocks();
1205
1206 iterate_blocks(arena);
1207 }
1208
1209 vmIntrinsicID BCEscapeAnalyzer::known_intrinsic() {
1210 vmIntrinsicID iid = method()->intrinsic_id();
1211 if (iid == vmIntrinsics::_getClass ||
1212 iid == vmIntrinsics::_hashCode) {
1213 return iid;
1214 } else {
1215 return vmIntrinsics::_none;
1216 }
1217 }
1218
1219 void BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsicID iid) {
1220 switch (iid) {
1221 case vmIntrinsics::_getClass:
1222 _return_local = false;
1223 _return_allocated = false;
1224 break;
1225 case vmIntrinsics::_hashCode:
1226 // initialized state is correct
1227 break;
1228 default:
1229 assert(false, "unexpected intrinsic");
1230 }
1231 }
1232
1233 void BCEscapeAnalyzer::initialize() {
1234 int i;
1235
1236 // clear escape information (method may have been deoptimized)
1237 methodData()->clear_escape_info();
1238
1239 // initialize escape state of object parameters
1240 ciSignature* sig = method()->signature();
1241 int j = 0;
1242 if (!method()->is_static()) {
1243 _arg_local.set(0);
1244 _arg_stack.set(0);
1245 j++;
1246 }
1247 for (i = 0; i < sig->count(); i++) {
1248 ciType* t = sig->type_at(i);
1249 if (!t->is_primitive_type()) {
1250 _arg_local.set(j);
1251 _arg_stack.set(j);
1252 }
1253 j += t->size();
1254 }
1255 assert(j == _arg_size, "just checking");
1256
1257 // start with optimistic assumption
1258 ciType *rt = _method->return_type();
1259 if (rt->is_primitive_type()) {
1260 _return_local = false;
1261 _return_allocated = false;
1262 } else {
1263 _return_local = true;
1264 _return_allocated = true;
1265 }
1266 _allocated_escapes = false;
1267 _unknown_modified = false;
1268 }
1269
1270 void BCEscapeAnalyzer::clear_escape_info() {
1271 ciSignature* sig = method()->signature();
1272 int arg_count = sig->count();
1273 ArgumentMap var;
1274 if (!method()->is_static()) {
1275 arg_count++; // allow for "this"
1276 }
1277 for (int i = 0; i < arg_count; i++) {
1278 set_arg_modified(i, OFFSET_ANY, 4);
1279 var.clear();
1280 var.set(i);
1281 set_modified(var, OFFSET_ANY, 4);
1282 set_global_escape(var);
1283 }
1284 _arg_local.clear();
1285 _arg_stack.clear();
1286 _arg_returned.clear();
1287 _return_local = false;
1288 _return_allocated = false;
1289 _allocated_escapes = true;
1290 _unknown_modified = true;
1291 }
1292
1293
1294 void BCEscapeAnalyzer::compute_escape_info() {
1295 int i;
1296 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1297
1298 vmIntrinsicID iid = known_intrinsic();
1299
1300 // check if method can be analyzed
1301 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1302 || _level > MaxBCEAEstimateLevel
1303 || method()->code_size() > MaxBCEAEstimateSize)) {
1304 if (BCEATraceLevel >= 1) {
1305 tty->print("Skipping method because: ");
1306 if (method()->is_abstract())
1307 tty->print_cr("method is abstract.");
1308 else if (method()->is_native())
1309 tty->print_cr("method is native.");
1310 else if (!method()->holder()->is_initialized())
1311 tty->print_cr("class of method is not initialized.");
1312 else if (_level > MaxBCEAEstimateLevel)
1313 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1314 _level, (int) MaxBCEAEstimateLevel);
1315 else if (method()->code_size() > MaxBCEAEstimateSize)
1316 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1317 method()->code_size(), (int) MaxBCEAEstimateSize);
1318 else
1319 ShouldNotReachHere();
1320 }
1321 clear_escape_info();
1322
1323 return;
1324 }
1325
1326 if (BCEATraceLevel >= 1) {
1327 tty->print("[EA] estimating escape information for");
1328 if (iid != vmIntrinsics::_none)
1329 tty->print(" intrinsic");
1330 method()->print_short_name();
1331 tty->print_cr(" (%d bytes)", method()->code_size());
1332 }
1333
1334 initialize();
1335
1336 // Do not scan method if it has no object parameters and
1337 // does not returns an object (_return_allocated is set in initialize()).
1338 if (_arg_local.is_empty() && !_return_allocated) {
1339 // Clear all info since method's bytecode was not analysed and
1340 // set pessimistic escape information.
1341 clear_escape_info();
1342 methodData()->set_eflag(MethodData::allocated_escapes);
1343 methodData()->set_eflag(MethodData::unknown_modified);
1344 methodData()->set_eflag(MethodData::estimated);
1345 return;
1346 }
1347
1348 if (iid != vmIntrinsics::_none)
1349 compute_escape_for_intrinsic(iid);
1350 else {
1351 do_analysis();
1352 }
1353
1354 // don't store interprocedural escape information if it introduces
1355 // dependencies or if method data is empty
1356 //
1357 if (!has_dependencies() && !methodData()->is_empty()) {
1358 for (i = 0; i < _arg_size; i++) {
1359 if (_arg_local.test(i)) {
1360 assert(_arg_stack.test(i), "inconsistent escape info");
1361 methodData()->set_arg_local(i);
1362 methodData()->set_arg_stack(i);
1363 } else if (_arg_stack.test(i)) {
1364 methodData()->set_arg_stack(i);
1365 }
1366 if (_arg_returned.test(i)) {
1367 methodData()->set_arg_returned(i);
1368 }
1369 methodData()->set_arg_modified(i, _arg_modified[i]);
1370 }
1371 if (_return_local) {
1372 methodData()->set_eflag(MethodData::return_local);
1373 }
1374 if (_return_allocated) {
1375 methodData()->set_eflag(MethodData::return_allocated);
1376 }
1377 if (_allocated_escapes) {
1378 methodData()->set_eflag(MethodData::allocated_escapes);
1379 }
1380 if (_unknown_modified) {
1381 methodData()->set_eflag(MethodData::unknown_modified);
1382 }
1383 methodData()->set_eflag(MethodData::estimated);
1384 }
1385 }
1386
1387 void BCEscapeAnalyzer::read_escape_info() {
1388 assert(methodData()->has_escape_info(), "no escape info available");
1389
1390 // read escape information from method descriptor
1391 for (int i = 0; i < _arg_size; i++) {
1392 if (methodData()->is_arg_local(i))
1393 _arg_local.set(i);
1394 if (methodData()->is_arg_stack(i))
1395 _arg_stack.set(i);
1396 if (methodData()->is_arg_returned(i))
1397 _arg_returned.set(i);
1398 _arg_modified[i] = methodData()->arg_modified(i);
1399 }
1400 _return_local = methodData()->eflag_set(MethodData::return_local);
1401 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1402 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1403 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1404
1405 }
1406
1407 #ifndef PRODUCT
1408 void BCEscapeAnalyzer::dump() {
1409 tty->print("[EA] estimated escape information for");
1410 method()->print_short_name();
1411 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1412 tty->print(" non-escaping args: ");
1413 _arg_local.print();
1414 tty->print(" stack-allocatable args: ");
1415 _arg_stack.print();
1416 if (_return_local) {
1417 tty->print(" returned args: ");
1418 _arg_returned.print();
1419 } else if (is_return_allocated()) {
1420 tty->print_cr(" return allocated value");
1421 } else {
1422 tty->print_cr(" return non-local value");
1423 }
1424 tty->print(" modified args: ");
1425 for (int i = 0; i < _arg_size; i++) {
1426 if (_arg_modified[i] == 0)
1427 tty->print(" 0");
1428 else
1429 tty->print(" 0x%x", _arg_modified[i]);
1430 }
1431 tty->cr();
1432 tty->print(" flags: ");
1433 if (_return_allocated)
1434 tty->print(" return_allocated");
1435 if (_allocated_escapes)
1436 tty->print(" allocated_escapes");
1437 if (_unknown_modified)
1438 tty->print(" unknown_modified");
1439 tty->cr();
1440 }
1441 #endif
1442
1443 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1444 : _arena(CURRENT_ENV->arena())
1445 , _conservative(method == nullptr || !EstimateArgEscape)
1446 , _method(method)
1447 , _methodData(method ? method->method_data() : nullptr)
1448 , _arg_size(method ? method->arg_size() : 0)
1449 , _arg_local(_arena)
1450 , _arg_stack(_arena)
1451 , _arg_returned(_arena)
1452 , _return_local(false)
1453 , _return_allocated(false)
1454 , _allocated_escapes(false)
1455 , _unknown_modified(false)
1456 , _dependencies(_arena, 4, 0, nullptr)
1457 , _parent(parent)
1458 , _level(parent == nullptr ? 0 : parent->level() + 1) {
1459 if (!_conservative) {
1460 _arg_local.clear();
1461 _arg_stack.clear();
1462 _arg_returned.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() == nullptr)
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
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+=4) {
1498 ciKlass* recv_klass = _dependencies.at(i+0)->as_klass();
1499 ciMethod* target = _dependencies.at(i+1)->as_method();
1500 ciKlass* resolved_klass = _dependencies.at(i+2)->as_klass();
1501 ciMethod* resolved_method = _dependencies.at(i+3)->as_method();
1502 deps->assert_unique_concrete_method(recv_klass, target, resolved_klass, resolved_method);
1503 }
1504 }