1 /*
2 * Copyright (c) 2005, 2021, 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
int_to_bit(uint e) const61 uint int_to_bit(uint e) const {
62 if (e > MAXBIT)
63 e = MAXBIT;
64 return (1 << (e + 2));
65 }
66
67 public:
ArgumentMap()68 ArgumentMap() { _bits = 0;}
set_bits(uint bits)69 void set_bits(uint bits) { _bits = bits;}
get_bits() const70 uint get_bits() const { return _bits;}
clear()71 void clear() { _bits = 0;}
set_all()72 void set_all() { _bits = ~0u; }
is_empty() const73 bool is_empty() const { return _bits == 0; }
contains(uint var) const74 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
is_singleton(uint var) const75 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
contains_unknown() const76 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
contains_allocated() const77 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
contains_vars() const78 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
set(uint var)79 void set(uint var) { _bits = int_to_bit(var); }
add(uint var)80 void add(uint var) { _bits |= int_to_bit(var); }
add_unknown()81 void add_unknown() { _bits = UNKNOWN; }
add_allocated()82 void add_allocated() { _bits = ALLOCATED; }
set_union(const ArgumentMap & am)83 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
set_difference(const ArgumentMap & am)84 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
operator ==(const ArgumentMap & am)85 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
operator !=(const ArgumentMap & am)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
StateInfo()98 StateInfo() {
99 empty_map.clear();
100 }
101
raw_pop()102 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
apop()103 ArgumentMap apop() { return raw_pop(); }
spop()104 void spop() { raw_pop(); }
lpop()105 void lpop() { spop(); spop(); }
raw_push(ArgumentMap i)106 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
apush(ArgumentMap i)107 void apush(ArgumentMap i) { raw_push(i); }
spush()108 void spush() { raw_push(empty_map); }
lpush()109 void lpush() { spush(); spush(); }
110
111 };
112
set_returned(ArgumentMap vars)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
is_argument(ArgumentMap vars)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
is_arg_stack(ArgumentMap vars)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
returns_all(ArgumentMap vars)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
clear_bits(ArgumentMap vars,VectorSet & bm)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
set_method_escape(ArgumentMap vars)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
set_global_escape(ArgumentMap vars,bool merge)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
set_modified(ArgumentMap vars,int offs,int size)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
is_recursive_call(ciMethod * callee)202 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
203 for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
204 if (scope->method() == callee) {
205 return true;
206 }
207 }
208 return false;
209 }
210
is_arg_modified(int arg,int offset,int size_in_bytes)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
set_arg_modified(int arg,int offset,int size_in_bytes)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
invoke(StateInfo & state,Bytecodes::Code code,ciMethod * target,ciKlass * holder)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 = NULL;
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 != NULL && !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
contains(uint arg_set1,uint arg_set2)366 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
367 return ((~arg_set1) | arg_set2) == 0;
368 }
369
370
iterate_one_block(ciBlock * blk,StateInfo & state,GrowableArray<ciBlock * > & successors)371 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
372
373 blk->set_processed();
374 ciBytecodeStream s(method());
375 int limit_bci = blk->limit_bci();
376 bool fall_through = false;
377 ArgumentMap allocated_obj;
378 allocated_obj.add_allocated();
379 ArgumentMap unknown_obj;
380 unknown_obj.add_unknown();
381 ArgumentMap empty_map;
382
383 s.reset_to_bci(blk->start_bci());
384 while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
385 fall_through = true;
386 switch (s.cur_bc()) {
387 case Bytecodes::_nop:
388 break;
389 case Bytecodes::_aconst_null:
390 state.apush(unknown_obj);
391 break;
392 case Bytecodes::_iconst_m1:
393 case Bytecodes::_iconst_0:
394 case Bytecodes::_iconst_1:
395 case Bytecodes::_iconst_2:
396 case Bytecodes::_iconst_3:
397 case Bytecodes::_iconst_4:
398 case Bytecodes::_iconst_5:
399 case Bytecodes::_fconst_0:
400 case Bytecodes::_fconst_1:
401 case Bytecodes::_fconst_2:
402 case Bytecodes::_bipush:
403 case Bytecodes::_sipush:
404 state.spush();
405 break;
406 case Bytecodes::_lconst_0:
407 case Bytecodes::_lconst_1:
408 case Bytecodes::_dconst_0:
409 case Bytecodes::_dconst_1:
410 state.lpush();
411 break;
412 case Bytecodes::_ldc:
413 case Bytecodes::_ldc_w:
414 case Bytecodes::_ldc2_w:
415 {
416 // Avoid calling get_constant() which will try to allocate
417 // unloaded constant. We need only constant's type.
418 int index = s.get_constant_pool_index();
419 constantTag tag = s.get_constant_pool_tag(index);
420 if (tag.is_long() || tag.is_double()) {
421 // Only longs and doubles use 2 stack slots.
422 state.lpush();
423 } else if (tag.basic_type() == T_OBJECT) {
424 state.apush(unknown_obj);
425 } else {
426 state.spush();
427 }
428 break;
429 }
430 case Bytecodes::_aload:
431 state.apush(state._vars[s.get_index()]);
432 break;
433 case Bytecodes::_iload:
434 case Bytecodes::_fload:
435 case Bytecodes::_iload_0:
436 case Bytecodes::_iload_1:
437 case Bytecodes::_iload_2:
438 case Bytecodes::_iload_3:
439 case Bytecodes::_fload_0:
440 case Bytecodes::_fload_1:
441 case Bytecodes::_fload_2:
442 case Bytecodes::_fload_3:
443 state.spush();
444 break;
445 case Bytecodes::_lload:
446 case Bytecodes::_dload:
447 case Bytecodes::_lload_0:
448 case Bytecodes::_lload_1:
449 case Bytecodes::_lload_2:
450 case Bytecodes::_lload_3:
451 case Bytecodes::_dload_0:
452 case Bytecodes::_dload_1:
453 case Bytecodes::_dload_2:
454 case Bytecodes::_dload_3:
455 state.lpush();
456 break;
457 case Bytecodes::_aload_0:
458 state.apush(state._vars[0]);
459 break;
460 case Bytecodes::_aload_1:
461 state.apush(state._vars[1]);
462 break;
463 case Bytecodes::_aload_2:
464 state.apush(state._vars[2]);
465 break;
466 case Bytecodes::_aload_3:
467 state.apush(state._vars[3]);
468 break;
469 case Bytecodes::_iaload:
470 case Bytecodes::_faload:
471 case Bytecodes::_baload:
472 case Bytecodes::_caload:
473 case Bytecodes::_saload:
474 state.spop();
475 set_method_escape(state.apop());
476 state.spush();
477 break;
478 case Bytecodes::_laload:
479 case Bytecodes::_daload:
480 state.spop();
481 set_method_escape(state.apop());
482 state.lpush();
483 break;
484 case Bytecodes::_aaload:
485 { state.spop();
486 ArgumentMap array = state.apop();
487 set_method_escape(array);
488 state.apush(unknown_obj);
489 }
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 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
559 break;
560 }
561 case Bytecodes::_pop:
562 state.raw_pop();
563 break;
564 case Bytecodes::_pop2:
565 state.raw_pop();
566 state.raw_pop();
567 break;
568 case Bytecodes::_dup:
569 { ArgumentMap w1 = state.raw_pop();
570 state.raw_push(w1);
571 state.raw_push(w1);
572 }
573 break;
574 case Bytecodes::_dup_x1:
575 { ArgumentMap w1 = state.raw_pop();
576 ArgumentMap w2 = state.raw_pop();
577 state.raw_push(w1);
578 state.raw_push(w2);
579 state.raw_push(w1);
580 }
581 break;
582 case Bytecodes::_dup_x2:
583 { ArgumentMap w1 = state.raw_pop();
584 ArgumentMap w2 = state.raw_pop();
585 ArgumentMap w3 = state.raw_pop();
586 state.raw_push(w1);
587 state.raw_push(w3);
588 state.raw_push(w2);
589 state.raw_push(w1);
590 }
591 break;
592 case Bytecodes::_dup2:
593 { ArgumentMap w1 = state.raw_pop();
594 ArgumentMap w2 = state.raw_pop();
595 state.raw_push(w2);
596 state.raw_push(w1);
597 state.raw_push(w2);
598 state.raw_push(w1);
599 }
600 break;
601 case Bytecodes::_dup2_x1:
602 { ArgumentMap w1 = state.raw_pop();
603 ArgumentMap w2 = state.raw_pop();
604 ArgumentMap w3 = state.raw_pop();
605 state.raw_push(w2);
606 state.raw_push(w1);
607 state.raw_push(w3);
608 state.raw_push(w2);
609 state.raw_push(w1);
610 }
611 break;
612 case Bytecodes::_dup2_x2:
613 { ArgumentMap w1 = state.raw_pop();
614 ArgumentMap w2 = state.raw_pop();
615 ArgumentMap w3 = state.raw_pop();
616 ArgumentMap w4 = state.raw_pop();
617 state.raw_push(w2);
618 state.raw_push(w1);
619 state.raw_push(w4);
620 state.raw_push(w3);
621 state.raw_push(w2);
622 state.raw_push(w1);
623 }
624 break;
625 case Bytecodes::_swap:
626 { ArgumentMap w1 = state.raw_pop();
627 ArgumentMap w2 = state.raw_pop();
628 state.raw_push(w1);
629 state.raw_push(w2);
630 }
631 break;
632 case Bytecodes::_iadd:
633 case Bytecodes::_fadd:
634 case Bytecodes::_isub:
635 case Bytecodes::_fsub:
636 case Bytecodes::_imul:
637 case Bytecodes::_fmul:
638 case Bytecodes::_idiv:
639 case Bytecodes::_fdiv:
640 case Bytecodes::_irem:
641 case Bytecodes::_frem:
642 case Bytecodes::_iand:
643 case Bytecodes::_ior:
644 case Bytecodes::_ixor:
645 state.spop();
646 state.spop();
647 state.spush();
648 break;
649 case Bytecodes::_ladd:
650 case Bytecodes::_dadd:
651 case Bytecodes::_lsub:
652 case Bytecodes::_dsub:
653 case Bytecodes::_lmul:
654 case Bytecodes::_dmul:
655 case Bytecodes::_ldiv:
656 case Bytecodes::_ddiv:
657 case Bytecodes::_lrem:
658 case Bytecodes::_drem:
659 case Bytecodes::_land:
660 case Bytecodes::_lor:
661 case Bytecodes::_lxor:
662 state.lpop();
663 state.lpop();
664 state.lpush();
665 break;
666 case Bytecodes::_ishl:
667 case Bytecodes::_ishr:
668 case Bytecodes::_iushr:
669 state.spop();
670 state.spop();
671 state.spush();
672 break;
673 case Bytecodes::_lshl:
674 case Bytecodes::_lshr:
675 case Bytecodes::_lushr:
676 state.spop();
677 state.lpop();
678 state.lpush();
679 break;
680 case Bytecodes::_ineg:
681 case Bytecodes::_fneg:
682 state.spop();
683 state.spush();
684 break;
685 case Bytecodes::_lneg:
686 case Bytecodes::_dneg:
687 state.lpop();
688 state.lpush();
689 break;
690 case Bytecodes::_iinc:
691 break;
692 case Bytecodes::_i2l:
693 case Bytecodes::_i2d:
694 case Bytecodes::_f2l:
695 case Bytecodes::_f2d:
696 state.spop();
697 state.lpush();
698 break;
699 case Bytecodes::_i2f:
700 case Bytecodes::_f2i:
701 state.spop();
702 state.spush();
703 break;
704 case Bytecodes::_l2i:
705 case Bytecodes::_l2f:
706 case Bytecodes::_d2i:
707 case Bytecodes::_d2f:
708 state.lpop();
709 state.spush();
710 break;
711 case Bytecodes::_l2d:
712 case Bytecodes::_d2l:
713 state.lpop();
714 state.lpush();
715 break;
716 case Bytecodes::_i2b:
717 case Bytecodes::_i2c:
718 case Bytecodes::_i2s:
719 state.spop();
720 state.spush();
721 break;
722 case Bytecodes::_lcmp:
723 case Bytecodes::_dcmpl:
724 case Bytecodes::_dcmpg:
725 state.lpop();
726 state.lpop();
727 state.spush();
728 break;
729 case Bytecodes::_fcmpl:
730 case Bytecodes::_fcmpg:
731 state.spop();
732 state.spop();
733 state.spush();
734 break;
735 case Bytecodes::_ifeq:
736 case Bytecodes::_ifne:
737 case Bytecodes::_iflt:
738 case Bytecodes::_ifge:
739 case Bytecodes::_ifgt:
740 case Bytecodes::_ifle:
741 {
742 state.spop();
743 int dest_bci = s.get_dest();
744 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
745 assert(s.next_bci() == limit_bci, "branch must end block");
746 successors.push(_methodBlocks->block_containing(dest_bci));
747 break;
748 }
749 case Bytecodes::_if_icmpeq:
750 case Bytecodes::_if_icmpne:
751 case Bytecodes::_if_icmplt:
752 case Bytecodes::_if_icmpge:
753 case Bytecodes::_if_icmpgt:
754 case Bytecodes::_if_icmple:
755 {
756 state.spop();
757 state.spop();
758 int dest_bci = s.get_dest();
759 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
760 assert(s.next_bci() == limit_bci, "branch must end block");
761 successors.push(_methodBlocks->block_containing(dest_bci));
762 break;
763 }
764 case Bytecodes::_if_acmpeq:
765 case Bytecodes::_if_acmpne:
766 {
767 set_method_escape(state.apop());
768 set_method_escape(state.apop());
769 int dest_bci = s.get_dest();
770 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
771 assert(s.next_bci() == limit_bci, "branch must end block");
772 successors.push(_methodBlocks->block_containing(dest_bci));
773 break;
774 }
775 case Bytecodes::_goto:
776 {
777 int dest_bci = s.get_dest();
778 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
779 assert(s.next_bci() == limit_bci, "branch must end block");
780 successors.push(_methodBlocks->block_containing(dest_bci));
781 fall_through = false;
782 break;
783 }
784 case Bytecodes::_jsr:
785 {
786 int dest_bci = s.get_dest();
787 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
788 assert(s.next_bci() == limit_bci, "branch must end block");
789 state.apush(empty_map);
790 successors.push(_methodBlocks->block_containing(dest_bci));
791 fall_through = false;
792 break;
793 }
794 case Bytecodes::_ret:
795 // we don't track the destination of a "ret" instruction
796 assert(s.next_bci() == limit_bci, "branch must end block");
797 fall_through = false;
798 break;
799 case Bytecodes::_return:
800 assert(s.next_bci() == limit_bci, "return must end block");
801 fall_through = false;
802 break;
803 case Bytecodes::_tableswitch:
804 {
805 state.spop();
806 Bytecode_tableswitch sw(&s);
807 int len = sw.length();
808 int dest_bci;
809 for (int i = 0; i < len; i++) {
810 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
811 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
812 successors.push(_methodBlocks->block_containing(dest_bci));
813 }
814 dest_bci = s.cur_bci() + sw.default_offset();
815 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
816 successors.push(_methodBlocks->block_containing(dest_bci));
817 assert(s.next_bci() == limit_bci, "branch must end block");
818 fall_through = false;
819 break;
820 }
821 case Bytecodes::_lookupswitch:
822 {
823 state.spop();
824 Bytecode_lookupswitch sw(&s);
825 int len = sw.number_of_pairs();
826 int dest_bci;
827 for (int i = 0; i < len; i++) {
828 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
829 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
830 successors.push(_methodBlocks->block_containing(dest_bci));
831 }
832 dest_bci = s.cur_bci() + sw.default_offset();
833 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
834 successors.push(_methodBlocks->block_containing(dest_bci));
835 fall_through = false;
836 break;
837 }
838 case Bytecodes::_ireturn:
839 case Bytecodes::_freturn:
840 state.spop();
841 fall_through = false;
842 break;
843 case Bytecodes::_lreturn:
844 case Bytecodes::_dreturn:
845 state.lpop();
846 fall_through = false;
847 break;
848 case Bytecodes::_areturn:
849 set_returned(state.apop());
850 fall_through = false;
851 break;
852 case Bytecodes::_getstatic:
853 case Bytecodes::_getfield:
854 { bool ignored_will_link;
855 ciField* field = s.get_field(ignored_will_link);
856 BasicType field_type = field->type()->basic_type();
857 if (s.cur_bc() != Bytecodes::_getstatic) {
858 set_method_escape(state.apop());
859 }
860 if (is_reference_type(field_type)) {
861 state.apush(unknown_obj);
862 } else if (type2size[field_type] == 1) {
863 state.spush();
864 } else {
865 state.lpush();
866 }
867 }
868 break;
869 case Bytecodes::_putstatic:
870 case Bytecodes::_putfield:
871 { bool will_link;
872 ciField* field = s.get_field(will_link);
873 BasicType field_type = field->type()->basic_type();
874 if (is_reference_type(field_type)) {
875 set_global_escape(state.apop());
876 } else if (type2size[field_type] == 1) {
877 state.spop();
878 } else {
879 state.lpop();
880 }
881 if (s.cur_bc() != Bytecodes::_putstatic) {
882 ArgumentMap p = state.apop();
883 set_method_escape(p);
884 set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
885 }
886 }
887 break;
888 case Bytecodes::_invokevirtual:
889 case Bytecodes::_invokespecial:
890 case Bytecodes::_invokestatic:
891 case Bytecodes::_invokedynamic:
892 case Bytecodes::_invokeinterface:
893 { bool ignored_will_link;
894 ciSignature* declared_signature = NULL;
895 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
896 ciKlass* holder = s.get_declared_method_holder();
897 assert(declared_signature != NULL, "cannot be null");
898 // If the current bytecode has an attached appendix argument,
899 // push an unknown object to represent that argument. (Analysis
900 // of dynamic call sites, especially invokehandle calls, needs
901 // the appendix argument on the stack, in addition to "regular" arguments
902 // pushed onto the stack by bytecode instructions preceding the call.)
903 //
904 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
905 // method to determine whether the current bytecode has an appendix argument.
906 // The has_appendix() method obtains the appendix from the
907 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
908 // resolution of dynamic call sites. Callees in the
909 // ciBytecodeStream::get_method() call above also access the _f1 field;
910 // interleaving the get_method() and has_appendix() calls in the current
911 // method with call site resolution can lead to an inconsistent view of
912 // the current method's argument count. In particular, some interleaving(s)
913 // can cause the method's argument count to not include the appendix, which
914 // then leads to stack over-/underflow in the escape analyzer.
915 //
916 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
917 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
918 // instructions, except if the call site is the _invokeBasic intrinsic
919 // (that intrinsic is always targeted by an invokehandle instruction but does
920 // not have an appendix argument).
921 if (target->is_loaded() &&
922 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
923 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
924 state.apush(unknown_obj);
925 }
926 // Pass in raw bytecode because we need to see invokehandle instructions.
927 invoke(state, s.cur_bc_raw(), target, holder);
928 // We are using the return type of the declared signature here because
929 // it might be a more concrete type than the one from the target (for
930 // e.g. invokedynamic and invokehandle).
931 ciType* return_type = declared_signature->return_type();
932 if (!return_type->is_primitive_type()) {
933 state.apush(unknown_obj);
934 } else if (return_type->is_one_word()) {
935 state.spush();
936 } else if (return_type->is_two_word()) {
937 state.lpush();
938 }
939 }
940 break;
941 case Bytecodes::_new:
942 state.apush(allocated_obj);
943 break;
944 case Bytecodes::_newarray:
945 case Bytecodes::_anewarray:
946 state.spop();
947 state.apush(allocated_obj);
948 break;
949 case Bytecodes::_multianewarray:
950 { int i = s.cur_bcp()[3];
951 while (i-- > 0) state.spop();
952 state.apush(allocated_obj);
953 }
954 break;
955 case Bytecodes::_arraylength:
956 set_method_escape(state.apop());
957 state.spush();
958 break;
959 case Bytecodes::_athrow:
960 set_global_escape(state.apop());
961 fall_through = false;
962 break;
963 case Bytecodes::_checkcast:
964 { ArgumentMap obj = state.apop();
965 set_method_escape(obj);
966 state.apush(obj);
967 }
968 break;
969 case Bytecodes::_instanceof:
970 set_method_escape(state.apop());
971 state.spush();
972 break;
973 case Bytecodes::_monitorenter:
974 case Bytecodes::_monitorexit:
975 state.apop();
976 break;
977 case Bytecodes::_wide:
978 ShouldNotReachHere();
979 break;
980 case Bytecodes::_ifnull:
981 case Bytecodes::_ifnonnull:
982 {
983 set_method_escape(state.apop());
984 int dest_bci = s.get_dest();
985 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
986 assert(s.next_bci() == limit_bci, "branch must end block");
987 successors.push(_methodBlocks->block_containing(dest_bci));
988 break;
989 }
990 case Bytecodes::_goto_w:
991 {
992 int dest_bci = s.get_far_dest();
993 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
994 assert(s.next_bci() == limit_bci, "branch must end block");
995 successors.push(_methodBlocks->block_containing(dest_bci));
996 fall_through = false;
997 break;
998 }
999 case Bytecodes::_jsr_w:
1000 {
1001 int dest_bci = s.get_far_dest();
1002 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1003 assert(s.next_bci() == limit_bci, "branch must end block");
1004 state.apush(empty_map);
1005 successors.push(_methodBlocks->block_containing(dest_bci));
1006 fall_through = false;
1007 break;
1008 }
1009 case Bytecodes::_breakpoint:
1010 break;
1011 default:
1012 ShouldNotReachHere();
1013 break;
1014 }
1015
1016 }
1017 if (fall_through) {
1018 int fall_through_bci = s.cur_bci();
1019 if (fall_through_bci < _method->code_size()) {
1020 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1021 successors.push(_methodBlocks->block_containing(fall_through_bci));
1022 }
1023 }
1024 }
1025
merge_block_states(StateInfo * blockstates,ciBlock * dest,StateInfo * s_state)1026 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1027 StateInfo *d_state = blockstates + dest->index();
1028 int nlocals = _method->max_locals();
1029
1030 // exceptions may cause transfer of control to handlers in the middle of a
1031 // block, so we don't merge the incoming state of exception handlers
1032 if (dest->is_handler())
1033 return;
1034 if (!d_state->_initialized ) {
1035 // destination not initialized, just copy
1036 for (int i = 0; i < nlocals; i++) {
1037 d_state->_vars[i] = s_state->_vars[i];
1038 }
1039 for (int i = 0; i < s_state->_stack_height; i++) {
1040 d_state->_stack[i] = s_state->_stack[i];
1041 }
1042 d_state->_stack_height = s_state->_stack_height;
1043 d_state->_max_stack = s_state->_max_stack;
1044 d_state->_initialized = true;
1045 } else if (!dest->processed()) {
1046 // we have not yet walked the bytecodes of dest, we can merge
1047 // the states
1048 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1049 for (int i = 0; i < nlocals; i++) {
1050 d_state->_vars[i].set_union(s_state->_vars[i]);
1051 }
1052 for (int i = 0; i < s_state->_stack_height; i++) {
1053 d_state->_stack[i].set_union(s_state->_stack[i]);
1054 }
1055 } else {
1056 // the bytecodes of dest have already been processed, mark any
1057 // arguments in the source state which are not in the dest state
1058 // as global escape.
1059 // Future refinement: we only need to mark these variable to the
1060 // maximum escape of any variables in dest state
1061 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1062 ArgumentMap extra_vars;
1063 for (int i = 0; i < nlocals; i++) {
1064 ArgumentMap t;
1065 t = s_state->_vars[i];
1066 t.set_difference(d_state->_vars[i]);
1067 extra_vars.set_union(t);
1068 }
1069 for (int i = 0; i < s_state->_stack_height; i++) {
1070 ArgumentMap t;
1071 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1072 t.clear();
1073 t = s_state->_stack[i];
1074 t.set_difference(d_state->_stack[i]);
1075 extra_vars.set_union(t);
1076 }
1077 set_global_escape(extra_vars, true);
1078 }
1079 }
1080
iterate_blocks(Arena * arena)1081 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1082 int numblocks = _methodBlocks->num_blocks();
1083 int stkSize = _method->max_stack();
1084 int numLocals = _method->max_locals();
1085 StateInfo state;
1086
1087 int datacount = (numblocks + 1) * (stkSize + numLocals);
1088 int datasize = datacount * sizeof(ArgumentMap);
1089 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1090 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1091 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1092 ArgumentMap *dp = statedata;
1093 state._vars = dp;
1094 dp += numLocals;
1095 state._stack = dp;
1096 dp += stkSize;
1097 state._initialized = false;
1098 state._max_stack = stkSize;
1099 for (int i = 0; i < numblocks; i++) {
1100 blockstates[i]._vars = dp;
1101 dp += numLocals;
1102 blockstates[i]._stack = dp;
1103 dp += stkSize;
1104 blockstates[i]._initialized = false;
1105 blockstates[i]._stack_height = 0;
1106 blockstates[i]._max_stack = stkSize;
1107 }
1108 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
1109 GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
1110
1111 _methodBlocks->clear_processed();
1112
1113 // initialize block 0 state from method signature
1114 ArgumentMap allVars; // all oop arguments to method
1115 ciSignature* sig = method()->signature();
1116 int j = 0;
1117 ciBlock* first_blk = _methodBlocks->block_containing(0);
1118 int fb_i = first_blk->index();
1119 if (!method()->is_static()) {
1120 // record information for "this"
1121 blockstates[fb_i]._vars[j].set(j);
1122 allVars.add(j);
1123 j++;
1124 }
1125 for (int i = 0; i < sig->count(); i++) {
1126 ciType* t = sig->type_at(i);
1127 if (!t->is_primitive_type()) {
1128 blockstates[fb_i]._vars[j].set(j);
1129 allVars.add(j);
1130 }
1131 j += t->size();
1132 }
1133 blockstates[fb_i]._initialized = true;
1134 assert(j == _arg_size, "just checking");
1135
1136 ArgumentMap unknown_map;
1137 unknown_map.add_unknown();
1138
1139 worklist.push(first_blk);
1140 while(worklist.length() > 0) {
1141 ciBlock *blk = worklist.pop();
1142 StateInfo *blkState = blockstates + blk->index();
1143 if (blk->is_handler() || blk->is_ret_target()) {
1144 // for an exception handler or a target of a ret instruction, we assume the worst case,
1145 // that any variable could contain any argument
1146 for (int i = 0; i < numLocals; i++) {
1147 state._vars[i] = allVars;
1148 }
1149 if (blk->is_handler()) {
1150 state._stack_height = 1;
1151 } else {
1152 state._stack_height = blkState->_stack_height;
1153 }
1154 for (int i = 0; i < state._stack_height; i++) {
1155 // ??? should this be unknown_map ???
1156 state._stack[i] = allVars;
1157 }
1158 } else {
1159 for (int i = 0; i < numLocals; i++) {
1160 state._vars[i] = blkState->_vars[i];
1161 }
1162 for (int i = 0; i < blkState->_stack_height; i++) {
1163 state._stack[i] = blkState->_stack[i];
1164 }
1165 state._stack_height = blkState->_stack_height;
1166 }
1167 iterate_one_block(blk, state, successors);
1168 // if this block has any exception handlers, push them
1169 // onto successor list
1170 if (blk->has_handler()) {
1171 DEBUG_ONLY(int handler_count = 0;)
1172 int blk_start = blk->start_bci();
1173 int blk_end = blk->limit_bci();
1174 for (int i = 0; i < numblocks; i++) {
1175 ciBlock *b = _methodBlocks->block(i);
1176 if (b->is_handler()) {
1177 int ex_start = b->ex_start_bci();
1178 int ex_end = b->ex_limit_bci();
1179 if ((ex_start >= blk_start && ex_start < blk_end) ||
1180 (ex_end > blk_start && ex_end <= blk_end)) {
1181 successors.push(b);
1182 }
1183 DEBUG_ONLY(handler_count++;)
1184 }
1185 }
1186 assert(handler_count > 0, "must find at least one handler");
1187 }
1188 // merge computed variable state with successors
1189 while(successors.length() > 0) {
1190 ciBlock *succ = successors.pop();
1191 merge_block_states(blockstates, succ, &state);
1192 if (!succ->processed())
1193 worklist.push(succ);
1194 }
1195 }
1196 }
1197
do_analysis()1198 void BCEscapeAnalyzer::do_analysis() {
1199 Arena* arena = CURRENT_ENV->arena();
1200 // identify basic blocks
1201 _methodBlocks = _method->get_method_blocks();
1202
1203 iterate_blocks(arena);
1204 }
1205
known_intrinsic()1206 vmIntrinsicID BCEscapeAnalyzer::known_intrinsic() {
1207 vmIntrinsicID iid = method()->intrinsic_id();
1208 if (iid == vmIntrinsics::_getClass ||
1209 iid == vmIntrinsics::_hashCode) {
1210 return iid;
1211 } else {
1212 return vmIntrinsics::_none;
1213 }
1214 }
1215
compute_escape_for_intrinsic(vmIntrinsicID iid)1216 void BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsicID iid) {
1217 switch (iid) {
1218 case vmIntrinsics::_getClass:
1219 _return_local = false;
1220 _return_allocated = false;
1221 break;
1222 case vmIntrinsics::_hashCode:
1223 // initialized state is correct
1224 break;
1225 default:
1226 assert(false, "unexpected intrinsic");
1227 }
1228 }
1229
initialize()1230 void BCEscapeAnalyzer::initialize() {
1231 int i;
1232
1233 // clear escape information (method may have been deoptimized)
1234 methodData()->clear_escape_info();
1235
1236 // initialize escape state of object parameters
1237 ciSignature* sig = method()->signature();
1238 int j = 0;
1239 if (!method()->is_static()) {
1240 _arg_local.set(0);
1241 _arg_stack.set(0);
1242 j++;
1243 }
1244 for (i = 0; i < sig->count(); i++) {
1245 ciType* t = sig->type_at(i);
1246 if (!t->is_primitive_type()) {
1247 _arg_local.set(j);
1248 _arg_stack.set(j);
1249 }
1250 j += t->size();
1251 }
1252 assert(j == _arg_size, "just checking");
1253
1254 // start with optimistic assumption
1255 ciType *rt = _method->return_type();
1256 if (rt->is_primitive_type()) {
1257 _return_local = false;
1258 _return_allocated = false;
1259 } else {
1260 _return_local = true;
1261 _return_allocated = true;
1262 }
1263 _allocated_escapes = false;
1264 _unknown_modified = false;
1265 }
1266
clear_escape_info()1267 void BCEscapeAnalyzer::clear_escape_info() {
1268 ciSignature* sig = method()->signature();
1269 int arg_count = sig->count();
1270 ArgumentMap var;
1271 if (!method()->is_static()) {
1272 arg_count++; // allow for "this"
1273 }
1274 for (int i = 0; i < arg_count; i++) {
1275 set_arg_modified(i, OFFSET_ANY, 4);
1276 var.clear();
1277 var.set(i);
1278 set_modified(var, OFFSET_ANY, 4);
1279 set_global_escape(var);
1280 }
1281 _arg_local.clear();
1282 _arg_stack.clear();
1283 _arg_returned.clear();
1284 _return_local = false;
1285 _return_allocated = false;
1286 _allocated_escapes = true;
1287 _unknown_modified = true;
1288 }
1289
1290
compute_escape_info()1291 void BCEscapeAnalyzer::compute_escape_info() {
1292 int i;
1293 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1294
1295 vmIntrinsicID iid = known_intrinsic();
1296
1297 // check if method can be analyzed
1298 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1299 || _level > MaxBCEAEstimateLevel
1300 || method()->code_size() > MaxBCEAEstimateSize)) {
1301 if (BCEATraceLevel >= 1) {
1302 tty->print("Skipping method because: ");
1303 if (method()->is_abstract())
1304 tty->print_cr("method is abstract.");
1305 else if (method()->is_native())
1306 tty->print_cr("method is native.");
1307 else if (!method()->holder()->is_initialized())
1308 tty->print_cr("class of method is not initialized.");
1309 else if (_level > MaxBCEAEstimateLevel)
1310 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1311 _level, (int) MaxBCEAEstimateLevel);
1312 else if (method()->code_size() > MaxBCEAEstimateSize)
1313 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1314 method()->code_size(), (int) MaxBCEAEstimateSize);
1315 else
1316 ShouldNotReachHere();
1317 }
1318 clear_escape_info();
1319
1320 return;
1321 }
1322
1323 if (BCEATraceLevel >= 1) {
1324 tty->print("[EA] estimating escape information for");
1325 if (iid != vmIntrinsics::_none)
1326 tty->print(" intrinsic");
1327 method()->print_short_name();
1328 tty->print_cr(" (%d bytes)", method()->code_size());
1329 }
1330
1331 initialize();
1332
1333 // Do not scan method if it has no object parameters and
1334 // does not returns an object (_return_allocated is set in initialize()).
1335 if (_arg_local.is_empty() && !_return_allocated) {
1336 // Clear all info since method's bytecode was not analysed and
1337 // set pessimistic escape information.
1338 clear_escape_info();
1339 methodData()->set_eflag(MethodData::allocated_escapes);
1340 methodData()->set_eflag(MethodData::unknown_modified);
1341 methodData()->set_eflag(MethodData::estimated);
1342 return;
1343 }
1344
1345 if (iid != vmIntrinsics::_none)
1346 compute_escape_for_intrinsic(iid);
1347 else {
1348 do_analysis();
1349 }
1350
1351 // don't store interprocedural escape information if it introduces
1352 // dependencies or if method data is empty
1353 //
1354 if (!has_dependencies() && !methodData()->is_empty()) {
1355 for (i = 0; i < _arg_size; i++) {
1356 if (_arg_local.test(i)) {
1357 assert(_arg_stack.test(i), "inconsistent escape info");
1358 methodData()->set_arg_local(i);
1359 methodData()->set_arg_stack(i);
1360 } else if (_arg_stack.test(i)) {
1361 methodData()->set_arg_stack(i);
1362 }
1363 if (_arg_returned.test(i)) {
1364 methodData()->set_arg_returned(i);
1365 }
1366 methodData()->set_arg_modified(i, _arg_modified[i]);
1367 }
1368 if (_return_local) {
1369 methodData()->set_eflag(MethodData::return_local);
1370 }
1371 if (_return_allocated) {
1372 methodData()->set_eflag(MethodData::return_allocated);
1373 }
1374 if (_allocated_escapes) {
1375 methodData()->set_eflag(MethodData::allocated_escapes);
1376 }
1377 if (_unknown_modified) {
1378 methodData()->set_eflag(MethodData::unknown_modified);
1379 }
1380 methodData()->set_eflag(MethodData::estimated);
1381 }
1382 }
1383
read_escape_info()1384 void BCEscapeAnalyzer::read_escape_info() {
1385 assert(methodData()->has_escape_info(), "no escape info available");
1386
1387 // read escape information from method descriptor
1388 for (int i = 0; i < _arg_size; i++) {
1389 if (methodData()->is_arg_local(i))
1390 _arg_local.set(i);
1391 if (methodData()->is_arg_stack(i))
1392 _arg_stack.set(i);
1393 if (methodData()->is_arg_returned(i))
1394 _arg_returned.set(i);
1395 _arg_modified[i] = methodData()->arg_modified(i);
1396 }
1397 _return_local = methodData()->eflag_set(MethodData::return_local);
1398 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1399 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1400 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1401
1402 }
1403
1404 #ifndef PRODUCT
dump()1405 void BCEscapeAnalyzer::dump() {
1406 tty->print("[EA] estimated escape information for");
1407 method()->print_short_name();
1408 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1409 tty->print(" non-escaping args: ");
1410 _arg_local.print();
1411 tty->print(" stack-allocatable args: ");
1412 _arg_stack.print();
1413 if (_return_local) {
1414 tty->print(" returned args: ");
1415 _arg_returned.print();
1416 } else if (is_return_allocated()) {
1417 tty->print_cr(" return allocated value");
1418 } else {
1419 tty->print_cr(" return non-local value");
1420 }
1421 tty->print(" modified args: ");
1422 for (int i = 0; i < _arg_size; i++) {
1423 if (_arg_modified[i] == 0)
1424 tty->print(" 0");
1425 else
1426 tty->print(" 0x%x", _arg_modified[i]);
1427 }
1428 tty->cr();
1429 tty->print(" flags: ");
1430 if (_return_allocated)
1431 tty->print(" return_allocated");
1432 if (_allocated_escapes)
1433 tty->print(" allocated_escapes");
1434 if (_unknown_modified)
1435 tty->print(" unknown_modified");
1436 tty->cr();
1437 }
1438 #endif
1439
BCEscapeAnalyzer(ciMethod * method,BCEscapeAnalyzer * parent)1440 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1441 : _arena(CURRENT_ENV->arena())
1442 , _conservative(method == NULL || !EstimateArgEscape)
1443 , _method(method)
1444 , _methodData(method ? method->method_data() : NULL)
1445 , _arg_size(method ? method->arg_size() : 0)
1446 , _arg_local(_arena)
1447 , _arg_stack(_arena)
1448 , _arg_returned(_arena)
1449 , _return_local(false)
1450 , _return_allocated(false)
1451 , _allocated_escapes(false)
1452 , _unknown_modified(false)
1453 , _dependencies(_arena, 4, 0, NULL)
1454 , _parent(parent)
1455 , _level(parent == NULL ? 0 : parent->level() + 1) {
1456 if (!_conservative) {
1457 _arg_local.clear();
1458 _arg_stack.clear();
1459 _arg_returned.clear();
1460 Arena* arena = CURRENT_ENV->arena();
1461 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1462 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1463
1464 if (methodData() == NULL)
1465 return;
1466 if (methodData()->has_escape_info()) {
1467 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1468 method->holder()->name()->as_utf8(),
1469 method->name()->as_utf8()));
1470 read_escape_info();
1471 } else {
1472 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1473 method->holder()->name()->as_utf8(),
1474 method->name()->as_utf8()));
1475
1476 compute_escape_info();
1477 methodData()->update_escape_info();
1478 }
1479 #ifndef PRODUCT
1480 if (BCEATraceLevel >= 3) {
1481 // dump escape information
1482 dump();
1483 }
1484 #endif
1485 }
1486 }
1487
copy_dependencies(Dependencies * deps)1488 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1489 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1490 // Also record evol dependencies so redefinition of the
1491 // callee will trigger recompilation.
1492 deps->assert_evol_method(method());
1493 }
1494 for (int i = 0; i < _dependencies.length(); i+=4) {
1495 ciKlass* recv_klass = _dependencies.at(i+0)->as_klass();
1496 ciMethod* target = _dependencies.at(i+1)->as_method();
1497 ciKlass* resolved_klass = _dependencies.at(i+2)->as_klass();
1498 ciMethod* resolved_method = _dependencies.at(i+3)->as_method();
1499 deps->assert_unique_concrete_method(recv_klass, target, resolved_klass, resolved_method);
1500 }
1501 }
1502