1 /*
2 * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "ci/ciConstant.hpp"
28 #include "ci/ciField.hpp"
29 #include "ci/ciMethodBlocks.hpp"
30 #include "ci/ciStreams.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/bitMap.inline.hpp"
35 #include "utilities/copy.hpp"
36
37 #ifndef PRODUCT
38 #define TRACE_BCEA(level, code) \
39 if (EstimateArgEscape && BCEATraceLevel >= level) { \
40 code; \
41 }
42 #else
43 #define TRACE_BCEA(level, code)
44 #endif
45
46 // Maintain a map of which arguments a local variable or
47 // stack slot may contain. In addition to tracking
48 // arguments, it tracks two special values, "allocated"
49 // which represents any object allocated in the current
50 // method, and "unknown" which is any other object.
51 // Up to 30 arguments are handled, with the last one
52 // representing summary information for any extra arguments
53 class BCEscapeAnalyzer::ArgumentMap {
54 uint _bits;
55 enum {MAXBIT = 29,
56 ALLOCATED = 1,
57 UNKNOWN = 2};
58
int_to_bit(uint e) const59 uint int_to_bit(uint e) const {
60 if (e > MAXBIT)
61 e = MAXBIT;
62 return (1 << (e + 2));
63 }
64
65 public:
ArgumentMap()66 ArgumentMap() { _bits = 0;}
set_bits(uint bits)67 void set_bits(uint bits) { _bits = bits;}
get_bits() const68 uint get_bits() const { return _bits;}
clear()69 void clear() { _bits = 0;}
set_all()70 void set_all() { _bits = ~0u; }
is_empty() const71 bool is_empty() const { return _bits == 0; }
contains(uint var) const72 bool contains(uint var) const { return (_bits & int_to_bit(var)) != 0; }
is_singleton(uint var) const73 bool is_singleton(uint var) const { return (_bits == int_to_bit(var)); }
contains_unknown() const74 bool contains_unknown() const { return (_bits & UNKNOWN) != 0; }
contains_allocated() const75 bool contains_allocated() const { return (_bits & ALLOCATED) != 0; }
contains_vars() const76 bool contains_vars() const { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
set(uint var)77 void set(uint var) { _bits = int_to_bit(var); }
add(uint var)78 void add(uint var) { _bits |= int_to_bit(var); }
add_unknown()79 void add_unknown() { _bits = UNKNOWN; }
add_allocated()80 void add_allocated() { _bits = ALLOCATED; }
set_union(const ArgumentMap & am)81 void set_union(const ArgumentMap &am) { _bits |= am._bits; }
set_difference(const ArgumentMap & am)82 void set_difference(const ArgumentMap &am) { _bits &= ~am._bits; }
operator =(const ArgumentMap & am)83 void operator=(const ArgumentMap &am) { _bits = am._bits; }
operator ==(const ArgumentMap & am)84 bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
operator !=(const ArgumentMap & am)85 bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
86 };
87
88 class BCEscapeAnalyzer::StateInfo {
89 public:
90 ArgumentMap *_vars;
91 ArgumentMap *_stack;
92 int _stack_height;
93 int _max_stack;
94 bool _initialized;
95 ArgumentMap empty_map;
96
StateInfo()97 StateInfo() {
98 empty_map.clear();
99 }
100
raw_pop()101 ArgumentMap raw_pop() { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
apop()102 ArgumentMap apop() { return raw_pop(); }
spop()103 void spop() { raw_pop(); }
lpop()104 void lpop() { spop(); spop(); }
raw_push(ArgumentMap i)105 void raw_push(ArgumentMap i) { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
apush(ArgumentMap i)106 void apush(ArgumentMap i) { raw_push(i); }
spush()107 void spush() { raw_push(empty_map); }
lpush()108 void lpush() { spush(); spush(); }
109
110 };
111
set_returned(ArgumentMap vars)112 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
113 for (int i = 0; i < _arg_size; i++) {
114 if (vars.contains(i))
115 _arg_returned.set(i);
116 }
117 _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
118 _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
119 }
120
121 // return true if any element of vars is an argument
is_argument(ArgumentMap vars)122 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
123 for (int i = 0; i < _arg_size; i++) {
124 if (vars.contains(i))
125 return true;
126 }
127 return false;
128 }
129
130 // return true if any element of vars is an arg_stack argument
is_arg_stack(ArgumentMap vars)131 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
132 if (_conservative)
133 return true;
134 for (int i = 0; i < _arg_size; i++) {
135 if (vars.contains(i) && _arg_stack.test(i))
136 return true;
137 }
138 return false;
139 }
140
141 // return true if all argument elements of vars are returned
returns_all(ArgumentMap vars)142 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
143 for (int i = 0; i < _arg_size; i++) {
144 if (vars.contains(i) && !_arg_returned.test(i)) {
145 return false;
146 }
147 }
148 return true;
149 }
150
clear_bits(ArgumentMap vars,VectorSet & bm)151 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
152 for (int i = 0; i < _arg_size; i++) {
153 if (vars.contains(i)) {
154 bm.remove(i);
155 }
156 }
157 }
158
set_method_escape(ArgumentMap vars)159 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
160 clear_bits(vars, _arg_local);
161 if (vars.contains_allocated()) {
162 _allocated_escapes = true;
163 }
164 }
165
set_global_escape(ArgumentMap vars,bool merge)166 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
167 clear_bits(vars, _arg_local);
168 clear_bits(vars, _arg_stack);
169 if (vars.contains_allocated())
170 _allocated_escapes = true;
171
172 if (merge && !vars.is_empty()) {
173 // Merge new state into already processed block.
174 // New state is not taken into account and
175 // it may invalidate set_returned() result.
176 if (vars.contains_unknown() || vars.contains_allocated()) {
177 _return_local = false;
178 }
179 if (vars.contains_unknown() || vars.contains_vars()) {
180 _return_allocated = false;
181 }
182 if (_return_local && vars.contains_vars() && !returns_all(vars)) {
183 // Return result should be invalidated if args in new
184 // state are not recorded in return state.
185 _return_local = false;
186 }
187 }
188 }
189
set_dirty(ArgumentMap vars)190 void BCEscapeAnalyzer::set_dirty(ArgumentMap vars) {
191 clear_bits(vars, _dirty);
192 }
193
set_modified(ArgumentMap vars,int offs,int size)194 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
195
196 for (int i = 0; i < _arg_size; i++) {
197 if (vars.contains(i)) {
198 set_arg_modified(i, offs, size);
199 }
200 }
201 if (vars.contains_unknown())
202 _unknown_modified = true;
203 }
204
is_recursive_call(ciMethod * callee)205 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
206 for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
207 if (scope->method() == callee) {
208 return true;
209 }
210 }
211 return false;
212 }
213
is_arg_modified(int arg,int offset,int size_in_bytes)214 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
215 if (offset == OFFSET_ANY)
216 return _arg_modified[arg] != 0;
217 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
218 bool modified = false;
219 int l = offset / HeapWordSize;
220 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
221 if (l > ARG_OFFSET_MAX)
222 l = ARG_OFFSET_MAX;
223 if (h > ARG_OFFSET_MAX+1)
224 h = ARG_OFFSET_MAX + 1;
225 for (int i = l; i < h; i++) {
226 modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
227 }
228 return modified;
229 }
230
set_arg_modified(int arg,int offset,int size_in_bytes)231 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
232 if (offset == OFFSET_ANY) {
233 _arg_modified[arg] = (uint) -1;
234 return;
235 }
236 assert(arg >= 0 && arg < _arg_size, "must be an argument.");
237 int l = offset / HeapWordSize;
238 int h = align_up(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
239 if (l > ARG_OFFSET_MAX)
240 l = ARG_OFFSET_MAX;
241 if (h > ARG_OFFSET_MAX+1)
242 h = ARG_OFFSET_MAX + 1;
243 for (int i = l; i < h; i++) {
244 _arg_modified[arg] |= (1 << i);
245 }
246 }
247
invoke(StateInfo & state,Bytecodes::Code code,ciMethod * target,ciKlass * holder)248 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
249 int i;
250
251 // retrieve information about the callee
252 ciInstanceKlass* klass = target->holder();
253 ciInstanceKlass* calling_klass = method()->holder();
254 ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
255 ciInstanceKlass* actual_recv = callee_holder;
256
257 // Some methods are obviously bindable without any type checks so
258 // convert them directly to an invokespecial or invokestatic.
259 if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
260 switch (code) {
261 case Bytecodes::_invokevirtual:
262 code = Bytecodes::_invokespecial;
263 break;
264 case Bytecodes::_invokehandle:
265 code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
266 break;
267 default:
268 break;
269 }
270 }
271
272 // compute size of arguments
273 int arg_size = target->invoke_arg_size(code);
274 int arg_base = MAX2(state._stack_height - arg_size, 0);
275
276 // direct recursive calls are skipped if they can be bound statically without introducing
277 // dependencies and if parameters are passed at the same position as in the current method
278 // other calls are skipped if there are no unescaped arguments passed to them
279 bool directly_recursive = (method() == target) &&
280 (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
281
282 // check if analysis of callee can safely be skipped
283 bool skip_callee = true;
284 for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
285 ArgumentMap arg = state._stack[i];
286 skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
287 }
288 // For now we conservatively skip invokedynamic.
289 if (code == Bytecodes::_invokedynamic) {
290 skip_callee = true;
291 }
292 if (skip_callee) {
293 TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
294 for (i = 0; i < arg_size; i++) {
295 set_method_escape(state.raw_pop());
296 }
297 _unknown_modified = true; // assume the worst since we don't analyze the called method
298 return;
299 }
300
301 // determine actual method (use CHA if necessary)
302 ciMethod* inline_target = NULL;
303 if (target->is_loaded() && klass->is_loaded()
304 && (klass->is_initialized() || (klass->is_interface() && target->holder()->is_initialized()))
305 && target->is_loaded()) {
306 if (code == Bytecodes::_invokestatic
307 || code == Bytecodes::_invokespecial
308 || (code == Bytecodes::_invokevirtual && target->is_final_method())) {
309 inline_target = target;
310 } else {
311 inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
312 }
313 }
314
315 if (inline_target != NULL && !is_recursive_call(inline_target)) {
316 // analyze callee
317 BCEscapeAnalyzer analyzer(inline_target, this);
318
319 // adjust escape state of actual parameters
320 bool must_record_dependencies = false;
321 for (i = arg_size - 1; i >= 0; i--) {
322 ArgumentMap arg = state.raw_pop();
323 // Check if callee arg is a caller arg or an allocated object
324 bool allocated = arg.contains_allocated();
325 if (!(is_argument(arg) || allocated))
326 continue;
327 for (int j = 0; j < _arg_size; j++) {
328 if (arg.contains(j)) {
329 _arg_modified[j] |= analyzer._arg_modified[i];
330 }
331 }
332 if (!(is_arg_stack(arg) || allocated)) {
333 // arguments have already been recognized as escaping
334 } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
335 set_method_escape(arg);
336 must_record_dependencies = true;
337 } else {
338 set_global_escape(arg);
339 }
340 }
341 _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
342
343 // record dependencies if at least one parameter retained stack-allocatable
344 if (must_record_dependencies) {
345 if (code == Bytecodes::_invokeinterface ||
346 (code == Bytecodes::_invokevirtual && !target->is_final_method())) {
347 _dependencies.append(actual_recv);
348 _dependencies.append(inline_target);
349 }
350 _dependencies.appendAll(analyzer.dependencies());
351 }
352 } else {
353 TRACE_BCEA(1, tty->print_cr("[EA] virtual method %s is not monomorphic.",
354 target->name()->as_utf8()));
355 // conservatively mark all actual parameters as escaping globally
356 for (i = 0; i < arg_size; i++) {
357 ArgumentMap arg = state.raw_pop();
358 if (!is_argument(arg))
359 continue;
360 set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
361 set_global_escape(arg);
362 }
363 _unknown_modified = true; // assume the worst since we don't know the called method
364 }
365 }
366
contains(uint arg_set1,uint arg_set2)367 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
368 return ((~arg_set1) | arg_set2) == 0;
369 }
370
371
iterate_one_block(ciBlock * blk,StateInfo & state,GrowableArray<ciBlock * > & successors)372 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
373
374 blk->set_processed();
375 ciBytecodeStream s(method());
376 int limit_bci = blk->limit_bci();
377 bool fall_through = false;
378 ArgumentMap allocated_obj;
379 allocated_obj.add_allocated();
380 ArgumentMap unknown_obj;
381 unknown_obj.add_unknown();
382 ArgumentMap empty_map;
383
384 s.reset_to_bci(blk->start_bci());
385 while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
386 fall_through = true;
387 switch (s.cur_bc()) {
388 case Bytecodes::_nop:
389 break;
390 case Bytecodes::_aconst_null:
391 state.apush(unknown_obj);
392 break;
393 case Bytecodes::_iconst_m1:
394 case Bytecodes::_iconst_0:
395 case Bytecodes::_iconst_1:
396 case Bytecodes::_iconst_2:
397 case Bytecodes::_iconst_3:
398 case Bytecodes::_iconst_4:
399 case Bytecodes::_iconst_5:
400 case Bytecodes::_fconst_0:
401 case Bytecodes::_fconst_1:
402 case Bytecodes::_fconst_2:
403 case Bytecodes::_bipush:
404 case Bytecodes::_sipush:
405 state.spush();
406 break;
407 case Bytecodes::_lconst_0:
408 case Bytecodes::_lconst_1:
409 case Bytecodes::_dconst_0:
410 case Bytecodes::_dconst_1:
411 state.lpush();
412 break;
413 case Bytecodes::_ldc:
414 case Bytecodes::_ldc_w:
415 case Bytecodes::_ldc2_w:
416 {
417 // Avoid calling get_constant() which will try to allocate
418 // unloaded constant. We need only constant's type.
419 int index = s.get_constant_pool_index();
420 constantTag tag = s.get_constant_pool_tag(index);
421 if (tag.is_long() || tag.is_double()) {
422 // Only longs and doubles use 2 stack slots.
423 state.lpush();
424 } else if (tag.basic_type() == T_OBJECT) {
425 state.apush(unknown_obj);
426 } else {
427 state.spush();
428 }
429 break;
430 }
431 case Bytecodes::_aload:
432 state.apush(state._vars[s.get_index()]);
433 break;
434 case Bytecodes::_iload:
435 case Bytecodes::_fload:
436 case Bytecodes::_iload_0:
437 case Bytecodes::_iload_1:
438 case Bytecodes::_iload_2:
439 case Bytecodes::_iload_3:
440 case Bytecodes::_fload_0:
441 case Bytecodes::_fload_1:
442 case Bytecodes::_fload_2:
443 case Bytecodes::_fload_3:
444 state.spush();
445 break;
446 case Bytecodes::_lload:
447 case Bytecodes::_dload:
448 case Bytecodes::_lload_0:
449 case Bytecodes::_lload_1:
450 case Bytecodes::_lload_2:
451 case Bytecodes::_lload_3:
452 case Bytecodes::_dload_0:
453 case Bytecodes::_dload_1:
454 case Bytecodes::_dload_2:
455 case Bytecodes::_dload_3:
456 state.lpush();
457 break;
458 case Bytecodes::_aload_0:
459 state.apush(state._vars[0]);
460 break;
461 case Bytecodes::_aload_1:
462 state.apush(state._vars[1]);
463 break;
464 case Bytecodes::_aload_2:
465 state.apush(state._vars[2]);
466 break;
467 case Bytecodes::_aload_3:
468 state.apush(state._vars[3]);
469 break;
470 case Bytecodes::_iaload:
471 case Bytecodes::_faload:
472 case Bytecodes::_baload:
473 case Bytecodes::_caload:
474 case Bytecodes::_saload:
475 state.spop();
476 set_method_escape(state.apop());
477 state.spush();
478 break;
479 case Bytecodes::_laload:
480 case Bytecodes::_daload:
481 state.spop();
482 set_method_escape(state.apop());
483 state.lpush();
484 break;
485 case Bytecodes::_aaload:
486 { state.spop();
487 ArgumentMap array = state.apop();
488 set_method_escape(array);
489 state.apush(unknown_obj);
490 set_dirty(array);
491 }
492 break;
493 case Bytecodes::_istore:
494 case Bytecodes::_fstore:
495 case Bytecodes::_istore_0:
496 case Bytecodes::_istore_1:
497 case Bytecodes::_istore_2:
498 case Bytecodes::_istore_3:
499 case Bytecodes::_fstore_0:
500 case Bytecodes::_fstore_1:
501 case Bytecodes::_fstore_2:
502 case Bytecodes::_fstore_3:
503 state.spop();
504 break;
505 case Bytecodes::_lstore:
506 case Bytecodes::_dstore:
507 case Bytecodes::_lstore_0:
508 case Bytecodes::_lstore_1:
509 case Bytecodes::_lstore_2:
510 case Bytecodes::_lstore_3:
511 case Bytecodes::_dstore_0:
512 case Bytecodes::_dstore_1:
513 case Bytecodes::_dstore_2:
514 case Bytecodes::_dstore_3:
515 state.lpop();
516 break;
517 case Bytecodes::_astore:
518 state._vars[s.get_index()] = state.apop();
519 break;
520 case Bytecodes::_astore_0:
521 state._vars[0] = state.apop();
522 break;
523 case Bytecodes::_astore_1:
524 state._vars[1] = state.apop();
525 break;
526 case Bytecodes::_astore_2:
527 state._vars[2] = state.apop();
528 break;
529 case Bytecodes::_astore_3:
530 state._vars[3] = state.apop();
531 break;
532 case Bytecodes::_iastore:
533 case Bytecodes::_fastore:
534 case Bytecodes::_bastore:
535 case Bytecodes::_castore:
536 case Bytecodes::_sastore:
537 {
538 state.spop();
539 state.spop();
540 ArgumentMap arr = state.apop();
541 set_method_escape(arr);
542 set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
543 break;
544 }
545 case Bytecodes::_lastore:
546 case Bytecodes::_dastore:
547 {
548 state.lpop();
549 state.spop();
550 ArgumentMap arr = state.apop();
551 set_method_escape(arr);
552 set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
553 break;
554 }
555 case Bytecodes::_aastore:
556 {
557 set_global_escape(state.apop());
558 state.spop();
559 ArgumentMap arr = state.apop();
560 set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
561 break;
562 }
563 case Bytecodes::_pop:
564 state.raw_pop();
565 break;
566 case Bytecodes::_pop2:
567 state.raw_pop();
568 state.raw_pop();
569 break;
570 case Bytecodes::_dup:
571 { ArgumentMap w1 = state.raw_pop();
572 state.raw_push(w1);
573 state.raw_push(w1);
574 }
575 break;
576 case Bytecodes::_dup_x1:
577 { ArgumentMap w1 = state.raw_pop();
578 ArgumentMap w2 = state.raw_pop();
579 state.raw_push(w1);
580 state.raw_push(w2);
581 state.raw_push(w1);
582 }
583 break;
584 case Bytecodes::_dup_x2:
585 { ArgumentMap w1 = state.raw_pop();
586 ArgumentMap w2 = state.raw_pop();
587 ArgumentMap w3 = state.raw_pop();
588 state.raw_push(w1);
589 state.raw_push(w3);
590 state.raw_push(w2);
591 state.raw_push(w1);
592 }
593 break;
594 case Bytecodes::_dup2:
595 { ArgumentMap w1 = state.raw_pop();
596 ArgumentMap w2 = state.raw_pop();
597 state.raw_push(w2);
598 state.raw_push(w1);
599 state.raw_push(w2);
600 state.raw_push(w1);
601 }
602 break;
603 case Bytecodes::_dup2_x1:
604 { ArgumentMap w1 = state.raw_pop();
605 ArgumentMap w2 = state.raw_pop();
606 ArgumentMap w3 = state.raw_pop();
607 state.raw_push(w2);
608 state.raw_push(w1);
609 state.raw_push(w3);
610 state.raw_push(w2);
611 state.raw_push(w1);
612 }
613 break;
614 case Bytecodes::_dup2_x2:
615 { ArgumentMap w1 = state.raw_pop();
616 ArgumentMap w2 = state.raw_pop();
617 ArgumentMap w3 = state.raw_pop();
618 ArgumentMap w4 = state.raw_pop();
619 state.raw_push(w2);
620 state.raw_push(w1);
621 state.raw_push(w4);
622 state.raw_push(w3);
623 state.raw_push(w2);
624 state.raw_push(w1);
625 }
626 break;
627 case Bytecodes::_swap:
628 { ArgumentMap w1 = state.raw_pop();
629 ArgumentMap w2 = state.raw_pop();
630 state.raw_push(w1);
631 state.raw_push(w2);
632 }
633 break;
634 case Bytecodes::_iadd:
635 case Bytecodes::_fadd:
636 case Bytecodes::_isub:
637 case Bytecodes::_fsub:
638 case Bytecodes::_imul:
639 case Bytecodes::_fmul:
640 case Bytecodes::_idiv:
641 case Bytecodes::_fdiv:
642 case Bytecodes::_irem:
643 case Bytecodes::_frem:
644 case Bytecodes::_iand:
645 case Bytecodes::_ior:
646 case Bytecodes::_ixor:
647 state.spop();
648 state.spop();
649 state.spush();
650 break;
651 case Bytecodes::_ladd:
652 case Bytecodes::_dadd:
653 case Bytecodes::_lsub:
654 case Bytecodes::_dsub:
655 case Bytecodes::_lmul:
656 case Bytecodes::_dmul:
657 case Bytecodes::_ldiv:
658 case Bytecodes::_ddiv:
659 case Bytecodes::_lrem:
660 case Bytecodes::_drem:
661 case Bytecodes::_land:
662 case Bytecodes::_lor:
663 case Bytecodes::_lxor:
664 state.lpop();
665 state.lpop();
666 state.lpush();
667 break;
668 case Bytecodes::_ishl:
669 case Bytecodes::_ishr:
670 case Bytecodes::_iushr:
671 state.spop();
672 state.spop();
673 state.spush();
674 break;
675 case Bytecodes::_lshl:
676 case Bytecodes::_lshr:
677 case Bytecodes::_lushr:
678 state.spop();
679 state.lpop();
680 state.lpush();
681 break;
682 case Bytecodes::_ineg:
683 case Bytecodes::_fneg:
684 state.spop();
685 state.spush();
686 break;
687 case Bytecodes::_lneg:
688 case Bytecodes::_dneg:
689 state.lpop();
690 state.lpush();
691 break;
692 case Bytecodes::_iinc:
693 break;
694 case Bytecodes::_i2l:
695 case Bytecodes::_i2d:
696 case Bytecodes::_f2l:
697 case Bytecodes::_f2d:
698 state.spop();
699 state.lpush();
700 break;
701 case Bytecodes::_i2f:
702 case Bytecodes::_f2i:
703 state.spop();
704 state.spush();
705 break;
706 case Bytecodes::_l2i:
707 case Bytecodes::_l2f:
708 case Bytecodes::_d2i:
709 case Bytecodes::_d2f:
710 state.lpop();
711 state.spush();
712 break;
713 case Bytecodes::_l2d:
714 case Bytecodes::_d2l:
715 state.lpop();
716 state.lpush();
717 break;
718 case Bytecodes::_i2b:
719 case Bytecodes::_i2c:
720 case Bytecodes::_i2s:
721 state.spop();
722 state.spush();
723 break;
724 case Bytecodes::_lcmp:
725 case Bytecodes::_dcmpl:
726 case Bytecodes::_dcmpg:
727 state.lpop();
728 state.lpop();
729 state.spush();
730 break;
731 case Bytecodes::_fcmpl:
732 case Bytecodes::_fcmpg:
733 state.spop();
734 state.spop();
735 state.spush();
736 break;
737 case Bytecodes::_ifeq:
738 case Bytecodes::_ifne:
739 case Bytecodes::_iflt:
740 case Bytecodes::_ifge:
741 case Bytecodes::_ifgt:
742 case Bytecodes::_ifle:
743 {
744 state.spop();
745 int dest_bci = s.get_dest();
746 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
747 assert(s.next_bci() == limit_bci, "branch must end block");
748 successors.push(_methodBlocks->block_containing(dest_bci));
749 break;
750 }
751 case Bytecodes::_if_icmpeq:
752 case Bytecodes::_if_icmpne:
753 case Bytecodes::_if_icmplt:
754 case Bytecodes::_if_icmpge:
755 case Bytecodes::_if_icmpgt:
756 case Bytecodes::_if_icmple:
757 {
758 state.spop();
759 state.spop();
760 int dest_bci = s.get_dest();
761 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
762 assert(s.next_bci() == limit_bci, "branch must end block");
763 successors.push(_methodBlocks->block_containing(dest_bci));
764 break;
765 }
766 case Bytecodes::_if_acmpeq:
767 case Bytecodes::_if_acmpne:
768 {
769 set_method_escape(state.apop());
770 set_method_escape(state.apop());
771 int dest_bci = s.get_dest();
772 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
773 assert(s.next_bci() == limit_bci, "branch must end block");
774 successors.push(_methodBlocks->block_containing(dest_bci));
775 break;
776 }
777 case Bytecodes::_goto:
778 {
779 int dest_bci = s.get_dest();
780 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
781 assert(s.next_bci() == limit_bci, "branch must end block");
782 successors.push(_methodBlocks->block_containing(dest_bci));
783 fall_through = false;
784 break;
785 }
786 case Bytecodes::_jsr:
787 {
788 int dest_bci = s.get_dest();
789 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
790 assert(s.next_bci() == limit_bci, "branch must end block");
791 state.apush(empty_map);
792 successors.push(_methodBlocks->block_containing(dest_bci));
793 fall_through = false;
794 break;
795 }
796 case Bytecodes::_ret:
797 // we don't track the destination of a "ret" instruction
798 assert(s.next_bci() == limit_bci, "branch must end block");
799 fall_through = false;
800 break;
801 case Bytecodes::_return:
802 assert(s.next_bci() == limit_bci, "return must end block");
803 fall_through = false;
804 break;
805 case Bytecodes::_tableswitch:
806 {
807 state.spop();
808 Bytecode_tableswitch sw(&s);
809 int len = sw.length();
810 int dest_bci;
811 for (int i = 0; i < len; i++) {
812 dest_bci = s.cur_bci() + sw.dest_offset_at(i);
813 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
814 successors.push(_methodBlocks->block_containing(dest_bci));
815 }
816 dest_bci = s.cur_bci() + sw.default_offset();
817 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
818 successors.push(_methodBlocks->block_containing(dest_bci));
819 assert(s.next_bci() == limit_bci, "branch must end block");
820 fall_through = false;
821 break;
822 }
823 case Bytecodes::_lookupswitch:
824 {
825 state.spop();
826 Bytecode_lookupswitch sw(&s);
827 int len = sw.number_of_pairs();
828 int dest_bci;
829 for (int i = 0; i < len; i++) {
830 dest_bci = s.cur_bci() + sw.pair_at(i).offset();
831 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
832 successors.push(_methodBlocks->block_containing(dest_bci));
833 }
834 dest_bci = s.cur_bci() + sw.default_offset();
835 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
836 successors.push(_methodBlocks->block_containing(dest_bci));
837 fall_through = false;
838 break;
839 }
840 case Bytecodes::_ireturn:
841 case Bytecodes::_freturn:
842 state.spop();
843 fall_through = false;
844 break;
845 case Bytecodes::_lreturn:
846 case Bytecodes::_dreturn:
847 state.lpop();
848 fall_through = false;
849 break;
850 case Bytecodes::_areturn:
851 set_returned(state.apop());
852 fall_through = false;
853 break;
854 case Bytecodes::_getstatic:
855 case Bytecodes::_getfield:
856 { bool ignored_will_link;
857 ciField* field = s.get_field(ignored_will_link);
858 BasicType field_type = field->type()->basic_type();
859 if (s.cur_bc() != Bytecodes::_getstatic) {
860 set_method_escape(state.apop());
861 }
862 if (is_reference_type(field_type)) {
863 state.apush(unknown_obj);
864 } else if (type2size[field_type] == 1) {
865 state.spush();
866 } else {
867 state.lpush();
868 }
869 }
870 break;
871 case Bytecodes::_putstatic:
872 case Bytecodes::_putfield:
873 { bool will_link;
874 ciField* field = s.get_field(will_link);
875 BasicType field_type = field->type()->basic_type();
876 if (is_reference_type(field_type)) {
877 set_global_escape(state.apop());
878 } else if (type2size[field_type] == 1) {
879 state.spop();
880 } else {
881 state.lpop();
882 }
883 if (s.cur_bc() != Bytecodes::_putstatic) {
884 ArgumentMap p = state.apop();
885 set_method_escape(p);
886 set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
887 }
888 }
889 break;
890 case Bytecodes::_invokevirtual:
891 case Bytecodes::_invokespecial:
892 case Bytecodes::_invokestatic:
893 case Bytecodes::_invokedynamic:
894 case Bytecodes::_invokeinterface:
895 { bool ignored_will_link;
896 ciSignature* declared_signature = NULL;
897 ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
898 ciKlass* holder = s.get_declared_method_holder();
899 assert(declared_signature != NULL, "cannot be null");
900 // If the current bytecode has an attached appendix argument,
901 // push an unknown object to represent that argument. (Analysis
902 // of dynamic call sites, especially invokehandle calls, needs
903 // the appendix argument on the stack, in addition to "regular" arguments
904 // pushed onto the stack by bytecode instructions preceding the call.)
905 //
906 // The escape analyzer does _not_ use the ciBytecodeStream::has_appendix(s)
907 // method to determine whether the current bytecode has an appendix argument.
908 // The has_appendix() method obtains the appendix from the
909 // ConstantPoolCacheEntry::_f1 field, which can happen concurrently with
910 // resolution of dynamic call sites. Callees in the
911 // ciBytecodeStream::get_method() call above also access the _f1 field;
912 // interleaving the get_method() and has_appendix() calls in the current
913 // method with call site resolution can lead to an inconsistent view of
914 // the current method's argument count. In particular, some interleaving(s)
915 // can cause the method's argument count to not include the appendix, which
916 // then leads to stack over-/underflow in the escape analyzer.
917 //
918 // Instead of pushing the argument if has_appendix() is true, the escape analyzer
919 // pushes an appendix for all call sites targeted by invokedynamic and invokehandle
920 // instructions, except if the call site is the _invokeBasic intrinsic
921 // (that intrinsic is always targeted by an invokehandle instruction but does
922 // not have an appendix argument).
923 if (target->is_loaded() &&
924 Bytecodes::has_optional_appendix(s.cur_bc_raw()) &&
925 target->intrinsic_id() != vmIntrinsics::_invokeBasic) {
926 state.apush(unknown_obj);
927 }
928 // Pass in raw bytecode because we need to see invokehandle instructions.
929 invoke(state, s.cur_bc_raw(), target, holder);
930 // We are using the return type of the declared signature here because
931 // it might be a more concrete type than the one from the target (for
932 // e.g. invokedynamic and invokehandle).
933 ciType* return_type = declared_signature->return_type();
934 if (!return_type->is_primitive_type()) {
935 state.apush(unknown_obj);
936 } else if (return_type->is_one_word()) {
937 state.spush();
938 } else if (return_type->is_two_word()) {
939 state.lpush();
940 }
941 }
942 break;
943 case Bytecodes::_new:
944 state.apush(allocated_obj);
945 break;
946 case Bytecodes::_newarray:
947 case Bytecodes::_anewarray:
948 state.spop();
949 state.apush(allocated_obj);
950 break;
951 case Bytecodes::_multianewarray:
952 { int i = s.cur_bcp()[3];
953 while (i-- > 0) state.spop();
954 state.apush(allocated_obj);
955 }
956 break;
957 case Bytecodes::_arraylength:
958 set_method_escape(state.apop());
959 state.spush();
960 break;
961 case Bytecodes::_athrow:
962 set_global_escape(state.apop());
963 fall_through = false;
964 break;
965 case Bytecodes::_checkcast:
966 { ArgumentMap obj = state.apop();
967 set_method_escape(obj);
968 state.apush(obj);
969 }
970 break;
971 case Bytecodes::_instanceof:
972 set_method_escape(state.apop());
973 state.spush();
974 break;
975 case Bytecodes::_monitorenter:
976 case Bytecodes::_monitorexit:
977 state.apop();
978 break;
979 case Bytecodes::_wide:
980 ShouldNotReachHere();
981 break;
982 case Bytecodes::_ifnull:
983 case Bytecodes::_ifnonnull:
984 {
985 set_method_escape(state.apop());
986 int dest_bci = s.get_dest();
987 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
988 assert(s.next_bci() == limit_bci, "branch must end block");
989 successors.push(_methodBlocks->block_containing(dest_bci));
990 break;
991 }
992 case Bytecodes::_goto_w:
993 {
994 int dest_bci = s.get_far_dest();
995 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
996 assert(s.next_bci() == limit_bci, "branch must end block");
997 successors.push(_methodBlocks->block_containing(dest_bci));
998 fall_through = false;
999 break;
1000 }
1001 case Bytecodes::_jsr_w:
1002 {
1003 int dest_bci = s.get_far_dest();
1004 assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
1005 assert(s.next_bci() == limit_bci, "branch must end block");
1006 state.apush(empty_map);
1007 successors.push(_methodBlocks->block_containing(dest_bci));
1008 fall_through = false;
1009 break;
1010 }
1011 case Bytecodes::_breakpoint:
1012 break;
1013 default:
1014 ShouldNotReachHere();
1015 break;
1016 }
1017
1018 }
1019 if (fall_through) {
1020 int fall_through_bci = s.cur_bci();
1021 if (fall_through_bci < _method->code_size()) {
1022 assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
1023 successors.push(_methodBlocks->block_containing(fall_through_bci));
1024 }
1025 }
1026 }
1027
merge_block_states(StateInfo * blockstates,ciBlock * dest,StateInfo * s_state)1028 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
1029 StateInfo *d_state = blockstates + dest->index();
1030 int nlocals = _method->max_locals();
1031
1032 // exceptions may cause transfer of control to handlers in the middle of a
1033 // block, so we don't merge the incoming state of exception handlers
1034 if (dest->is_handler())
1035 return;
1036 if (!d_state->_initialized ) {
1037 // destination not initialized, just copy
1038 for (int i = 0; i < nlocals; i++) {
1039 d_state->_vars[i] = s_state->_vars[i];
1040 }
1041 for (int i = 0; i < s_state->_stack_height; i++) {
1042 d_state->_stack[i] = s_state->_stack[i];
1043 }
1044 d_state->_stack_height = s_state->_stack_height;
1045 d_state->_max_stack = s_state->_max_stack;
1046 d_state->_initialized = true;
1047 } else if (!dest->processed()) {
1048 // we have not yet walked the bytecodes of dest, we can merge
1049 // the states
1050 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1051 for (int i = 0; i < nlocals; i++) {
1052 d_state->_vars[i].set_union(s_state->_vars[i]);
1053 }
1054 for (int i = 0; i < s_state->_stack_height; i++) {
1055 d_state->_stack[i].set_union(s_state->_stack[i]);
1056 }
1057 } else {
1058 // the bytecodes of dest have already been processed, mark any
1059 // arguments in the source state which are not in the dest state
1060 // as global escape.
1061 // Future refinement: we only need to mark these variable to the
1062 // maximum escape of any variables in dest state
1063 assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
1064 ArgumentMap extra_vars;
1065 for (int i = 0; i < nlocals; i++) {
1066 ArgumentMap t;
1067 t = s_state->_vars[i];
1068 t.set_difference(d_state->_vars[i]);
1069 extra_vars.set_union(t);
1070 }
1071 for (int i = 0; i < s_state->_stack_height; i++) {
1072 ArgumentMap t;
1073 //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
1074 t.clear();
1075 t = s_state->_stack[i];
1076 t.set_difference(d_state->_stack[i]);
1077 extra_vars.set_union(t);
1078 }
1079 set_global_escape(extra_vars, true);
1080 }
1081 }
1082
iterate_blocks(Arena * arena)1083 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
1084 int numblocks = _methodBlocks->num_blocks();
1085 int stkSize = _method->max_stack();
1086 int numLocals = _method->max_locals();
1087 StateInfo state;
1088
1089 int datacount = (numblocks + 1) * (stkSize + numLocals);
1090 int datasize = datacount * sizeof(ArgumentMap);
1091 StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
1092 ArgumentMap *statedata = (ArgumentMap *) arena->Amalloc(datasize);
1093 for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
1094 ArgumentMap *dp = statedata;
1095 state._vars = dp;
1096 dp += numLocals;
1097 state._stack = dp;
1098 dp += stkSize;
1099 state._initialized = false;
1100 state._max_stack = stkSize;
1101 for (int i = 0; i < numblocks; i++) {
1102 blockstates[i]._vars = dp;
1103 dp += numLocals;
1104 blockstates[i]._stack = dp;
1105 dp += stkSize;
1106 blockstates[i]._initialized = false;
1107 blockstates[i]._stack_height = 0;
1108 blockstates[i]._max_stack = stkSize;
1109 }
1110 GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
1111 GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
1112
1113 _methodBlocks->clear_processed();
1114
1115 // initialize block 0 state from method signature
1116 ArgumentMap allVars; // all oop arguments to method
1117 ciSignature* sig = method()->signature();
1118 int j = 0;
1119 ciBlock* first_blk = _methodBlocks->block_containing(0);
1120 int fb_i = first_blk->index();
1121 if (!method()->is_static()) {
1122 // record information for "this"
1123 blockstates[fb_i]._vars[j].set(j);
1124 allVars.add(j);
1125 j++;
1126 }
1127 for (int i = 0; i < sig->count(); i++) {
1128 ciType* t = sig->type_at(i);
1129 if (!t->is_primitive_type()) {
1130 blockstates[fb_i]._vars[j].set(j);
1131 allVars.add(j);
1132 }
1133 j += t->size();
1134 }
1135 blockstates[fb_i]._initialized = true;
1136 assert(j == _arg_size, "just checking");
1137
1138 ArgumentMap unknown_map;
1139 unknown_map.add_unknown();
1140
1141 worklist.push(first_blk);
1142 while(worklist.length() > 0) {
1143 ciBlock *blk = worklist.pop();
1144 StateInfo *blkState = blockstates + blk->index();
1145 if (blk->is_handler() || blk->is_ret_target()) {
1146 // for an exception handler or a target of a ret instruction, we assume the worst case,
1147 // that any variable could contain any argument
1148 for (int i = 0; i < numLocals; i++) {
1149 state._vars[i] = allVars;
1150 }
1151 if (blk->is_handler()) {
1152 state._stack_height = 1;
1153 } else {
1154 state._stack_height = blkState->_stack_height;
1155 }
1156 for (int i = 0; i < state._stack_height; i++) {
1157 // ??? should this be unknown_map ???
1158 state._stack[i] = allVars;
1159 }
1160 } else {
1161 for (int i = 0; i < numLocals; i++) {
1162 state._vars[i] = blkState->_vars[i];
1163 }
1164 for (int i = 0; i < blkState->_stack_height; i++) {
1165 state._stack[i] = blkState->_stack[i];
1166 }
1167 state._stack_height = blkState->_stack_height;
1168 }
1169 iterate_one_block(blk, state, successors);
1170 // if this block has any exception handlers, push them
1171 // onto successor list
1172 if (blk->has_handler()) {
1173 DEBUG_ONLY(int handler_count = 0;)
1174 int blk_start = blk->start_bci();
1175 int blk_end = blk->limit_bci();
1176 for (int i = 0; i < numblocks; i++) {
1177 ciBlock *b = _methodBlocks->block(i);
1178 if (b->is_handler()) {
1179 int ex_start = b->ex_start_bci();
1180 int ex_end = b->ex_limit_bci();
1181 if ((ex_start >= blk_start && ex_start < blk_end) ||
1182 (ex_end > blk_start && ex_end <= blk_end)) {
1183 successors.push(b);
1184 }
1185 DEBUG_ONLY(handler_count++;)
1186 }
1187 }
1188 assert(handler_count > 0, "must find at least one handler");
1189 }
1190 // merge computed variable state with successors
1191 while(successors.length() > 0) {
1192 ciBlock *succ = successors.pop();
1193 merge_block_states(blockstates, succ, &state);
1194 if (!succ->processed())
1195 worklist.push(succ);
1196 }
1197 }
1198 }
1199
do_analysis()1200 void BCEscapeAnalyzer::do_analysis() {
1201 Arena* arena = CURRENT_ENV->arena();
1202 // identify basic blocks
1203 _methodBlocks = _method->get_method_blocks();
1204
1205 iterate_blocks(arena);
1206 }
1207
known_intrinsic()1208 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
1209 vmIntrinsics::ID iid = method()->intrinsic_id();
1210 if (iid == vmIntrinsics::_getClass ||
1211 iid == vmIntrinsics::_hashCode) {
1212 return iid;
1213 } else {
1214 return vmIntrinsics::_none;
1215 }
1216 }
1217
compute_escape_for_intrinsic(vmIntrinsics::ID iid)1218 void BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
1219 switch (iid) {
1220 case vmIntrinsics::_getClass:
1221 _return_local = false;
1222 _return_allocated = false;
1223 break;
1224 case vmIntrinsics::_hashCode:
1225 // initialized state is correct
1226 break;
1227 default:
1228 assert(false, "unexpected intrinsic");
1229 }
1230 }
1231
initialize()1232 void BCEscapeAnalyzer::initialize() {
1233 int i;
1234
1235 // clear escape information (method may have been deoptimized)
1236 methodData()->clear_escape_info();
1237
1238 // initialize escape state of object parameters
1239 ciSignature* sig = method()->signature();
1240 int j = 0;
1241 if (!method()->is_static()) {
1242 _arg_local.set(0);
1243 _arg_stack.set(0);
1244 j++;
1245 }
1246 for (i = 0; i < sig->count(); i++) {
1247 ciType* t = sig->type_at(i);
1248 if (!t->is_primitive_type()) {
1249 _arg_local.set(j);
1250 _arg_stack.set(j);
1251 }
1252 j += t->size();
1253 }
1254 assert(j == _arg_size, "just checking");
1255
1256 // start with optimistic assumption
1257 ciType *rt = _method->return_type();
1258 if (rt->is_primitive_type()) {
1259 _return_local = false;
1260 _return_allocated = false;
1261 } else {
1262 _return_local = true;
1263 _return_allocated = true;
1264 }
1265 _allocated_escapes = false;
1266 _unknown_modified = false;
1267 }
1268
clear_escape_info()1269 void BCEscapeAnalyzer::clear_escape_info() {
1270 ciSignature* sig = method()->signature();
1271 int arg_count = sig->count();
1272 ArgumentMap var;
1273 if (!method()->is_static()) {
1274 arg_count++; // allow for "this"
1275 }
1276 for (int i = 0; i < arg_count; i++) {
1277 set_arg_modified(i, OFFSET_ANY, 4);
1278 var.clear();
1279 var.set(i);
1280 set_modified(var, OFFSET_ANY, 4);
1281 set_global_escape(var);
1282 }
1283 _arg_local.clear();
1284 _arg_stack.clear();
1285 _arg_returned.clear();
1286 _return_local = false;
1287 _return_allocated = false;
1288 _allocated_escapes = true;
1289 _unknown_modified = true;
1290 }
1291
1292
compute_escape_info()1293 void BCEscapeAnalyzer::compute_escape_info() {
1294 int i;
1295 assert(!methodData()->has_escape_info(), "do not overwrite escape info");
1296
1297 vmIntrinsics::ID iid = known_intrinsic();
1298
1299 // check if method can be analyzed
1300 if (iid == vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
1301 || _level > MaxBCEAEstimateLevel
1302 || method()->code_size() > MaxBCEAEstimateSize)) {
1303 if (BCEATraceLevel >= 1) {
1304 tty->print("Skipping method because: ");
1305 if (method()->is_abstract())
1306 tty->print_cr("method is abstract.");
1307 else if (method()->is_native())
1308 tty->print_cr("method is native.");
1309 else if (!method()->holder()->is_initialized())
1310 tty->print_cr("class of method is not initialized.");
1311 else if (_level > MaxBCEAEstimateLevel)
1312 tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
1313 _level, (int) MaxBCEAEstimateLevel);
1314 else if (method()->code_size() > MaxBCEAEstimateSize)
1315 tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
1316 method()->code_size(), (int) MaxBCEAEstimateSize);
1317 else
1318 ShouldNotReachHere();
1319 }
1320 clear_escape_info();
1321
1322 return;
1323 }
1324
1325 if (BCEATraceLevel >= 1) {
1326 tty->print("[EA] estimating escape information for");
1327 if (iid != vmIntrinsics::_none)
1328 tty->print(" intrinsic");
1329 method()->print_short_name();
1330 tty->print_cr(" (%d bytes)", method()->code_size());
1331 }
1332
1333 initialize();
1334
1335 // Do not scan method if it has no object parameters and
1336 // does not returns an object (_return_allocated is set in initialize()).
1337 if (_arg_local.is_empty() && !_return_allocated) {
1338 // Clear all info since method's bytecode was not analysed and
1339 // set pessimistic escape information.
1340 clear_escape_info();
1341 methodData()->set_eflag(MethodData::allocated_escapes);
1342 methodData()->set_eflag(MethodData::unknown_modified);
1343 methodData()->set_eflag(MethodData::estimated);
1344 return;
1345 }
1346
1347 if (iid != vmIntrinsics::_none)
1348 compute_escape_for_intrinsic(iid);
1349 else {
1350 do_analysis();
1351 }
1352
1353 // don't store interprocedural escape information if it introduces
1354 // dependencies or if method data is empty
1355 //
1356 if (!has_dependencies() && !methodData()->is_empty()) {
1357 for (i = 0; i < _arg_size; i++) {
1358 if (_arg_local.test(i)) {
1359 assert(_arg_stack.test(i), "inconsistent escape info");
1360 methodData()->set_arg_local(i);
1361 methodData()->set_arg_stack(i);
1362 } else if (_arg_stack.test(i)) {
1363 methodData()->set_arg_stack(i);
1364 }
1365 if (_arg_returned.test(i)) {
1366 methodData()->set_arg_returned(i);
1367 }
1368 methodData()->set_arg_modified(i, _arg_modified[i]);
1369 }
1370 if (_return_local) {
1371 methodData()->set_eflag(MethodData::return_local);
1372 }
1373 if (_return_allocated) {
1374 methodData()->set_eflag(MethodData::return_allocated);
1375 }
1376 if (_allocated_escapes) {
1377 methodData()->set_eflag(MethodData::allocated_escapes);
1378 }
1379 if (_unknown_modified) {
1380 methodData()->set_eflag(MethodData::unknown_modified);
1381 }
1382 methodData()->set_eflag(MethodData::estimated);
1383 }
1384 }
1385
read_escape_info()1386 void BCEscapeAnalyzer::read_escape_info() {
1387 assert(methodData()->has_escape_info(), "no escape info available");
1388
1389 // read escape information from method descriptor
1390 for (int i = 0; i < _arg_size; i++) {
1391 if (methodData()->is_arg_local(i))
1392 _arg_local.set(i);
1393 if (methodData()->is_arg_stack(i))
1394 _arg_stack.set(i);
1395 if (methodData()->is_arg_returned(i))
1396 _arg_returned.set(i);
1397 _arg_modified[i] = methodData()->arg_modified(i);
1398 }
1399 _return_local = methodData()->eflag_set(MethodData::return_local);
1400 _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
1401 _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
1402 _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
1403
1404 }
1405
1406 #ifndef PRODUCT
dump()1407 void BCEscapeAnalyzer::dump() {
1408 tty->print("[EA] estimated escape information for");
1409 method()->print_short_name();
1410 tty->print_cr(has_dependencies() ? " (not stored)" : "");
1411 tty->print(" non-escaping args: ");
1412 _arg_local.print();
1413 tty->print(" stack-allocatable args: ");
1414 _arg_stack.print();
1415 if (_return_local) {
1416 tty->print(" returned args: ");
1417 _arg_returned.print();
1418 } else if (is_return_allocated()) {
1419 tty->print_cr(" return allocated value");
1420 } else {
1421 tty->print_cr(" return non-local value");
1422 }
1423 tty->print(" modified args: ");
1424 for (int i = 0; i < _arg_size; i++) {
1425 if (_arg_modified[i] == 0)
1426 tty->print(" 0");
1427 else
1428 tty->print(" 0x%x", _arg_modified[i]);
1429 }
1430 tty->cr();
1431 tty->print(" flags: ");
1432 if (_return_allocated)
1433 tty->print(" return_allocated");
1434 if (_allocated_escapes)
1435 tty->print(" allocated_escapes");
1436 if (_unknown_modified)
1437 tty->print(" unknown_modified");
1438 tty->cr();
1439 }
1440 #endif
1441
BCEscapeAnalyzer(ciMethod * method,BCEscapeAnalyzer * parent)1442 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
1443 : _arena(CURRENT_ENV->arena())
1444 , _conservative(method == NULL || !EstimateArgEscape)
1445 , _method(method)
1446 , _methodData(method ? method->method_data() : NULL)
1447 , _arg_size(method ? method->arg_size() : 0)
1448 , _arg_local(_arena)
1449 , _arg_stack(_arena)
1450 , _arg_returned(_arena)
1451 , _dirty(_arena)
1452 , _return_local(false)
1453 , _return_allocated(false)
1454 , _allocated_escapes(false)
1455 , _unknown_modified(false)
1456 , _dependencies(_arena, 4, 0, NULL)
1457 , _parent(parent)
1458 , _level(parent == NULL ? 0 : parent->level() + 1) {
1459 if (!_conservative) {
1460 _arg_local.clear();
1461 _arg_stack.clear();
1462 _arg_returned.clear();
1463 _dirty.clear();
1464 Arena* arena = CURRENT_ENV->arena();
1465 _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
1466 Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
1467
1468 if (methodData() == NULL)
1469 return;
1470 if (methodData()->has_escape_info()) {
1471 TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
1472 method->holder()->name()->as_utf8(),
1473 method->name()->as_utf8()));
1474 read_escape_info();
1475 } else {
1476 TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
1477 method->holder()->name()->as_utf8(),
1478 method->name()->as_utf8()));
1479
1480 compute_escape_info();
1481 methodData()->update_escape_info();
1482 }
1483 #ifndef PRODUCT
1484 if (BCEATraceLevel >= 3) {
1485 // dump escape information
1486 dump();
1487 }
1488 #endif
1489 }
1490 }
1491
copy_dependencies(Dependencies * deps)1492 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
1493 if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
1494 // Also record evol dependencies so redefinition of the
1495 // callee will trigger recompilation.
1496 deps->assert_evol_method(method());
1497 }
1498 for (int i = 0; i < _dependencies.length(); i+=2) {
1499 ciKlass *k = _dependencies.at(i)->as_klass();
1500 ciMethod *m = _dependencies.at(i+1)->as_method();
1501 deps->assert_unique_concrete_method(k, m);
1502 }
1503 }
1504