1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)ciTypeFlow.cpp 1.47 07/09/28 10:23:20 JVM"
3 #endif
4 /*
5 * Copyright 2000-2007 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 #include "incls/_precompiled.incl"
29 #include "incls/_ciTypeFlow.cpp.incl"
30
31 // ciTypeFlow::JsrSet
32 //
33 // A JsrSet represents some set of JsrRecords. This class
34 // is used to record a set of all jsr routines which we permit
35 // execution to return (ret) from.
36 //
37 // During abstract interpretation, JsrSets are used to determine
38 // whether two paths which reach a given block are unique, and
39 // should be cloned apart, or are compatible, and should merge
40 // together.
41
42 // ------------------------------------------------------------------
43 // ciTypeFlow::JsrSet::JsrSet
44 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
45 if (arena != NULL) {
46 // Allocate growable array in Arena.
47 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
48 } else {
49 // Allocate growable array in current ResourceArea.
50 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
51 }
52 }
53
54 // ------------------------------------------------------------------
55 // ciTypeFlow::JsrSet::copy_into
56 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
57 int len = size();
58 jsrs->_set->clear();
59 for (int i = 0; i < len; i++) {
60 jsrs->_set->append(_set->at(i));
61 }
62 }
63
64 // ------------------------------------------------------------------
65 // ciTypeFlow::JsrSet::is_compatible_with
66 //
67 // !!!! MISGIVINGS ABOUT THIS... disregard
68 //
69 // Is this JsrSet compatible with some other JsrSet?
70 //
71 // In set-theoretic terms, a JsrSet can be viewed as a partial function
72 // from entry addresses to return addresses. Two JsrSets A and B are
73 // compatible iff
74 //
75 // For any x,
76 // A(x) defined and B(x) defined implies A(x) == B(x)
77 //
78 // Less formally, two JsrSets are compatible when they have identical
79 // return addresses for any entry addresses they share in common.
80 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
81 // Walk through both sets in parallel. If the same entry address
82 // appears in both sets, then the return address must match for
83 // the sets to be compatible.
84 int size1 = size();
85 int size2 = other->size();
86
87 // Special case. If nothing is on the jsr stack, then there can
88 // be no ret.
89 if (size2 == 0) {
90 return true;
91 } else if (size1 != size2) {
92 return false;
93 } else {
94 for (int i = 0; i < size1; i++) {
95 JsrRecord* record1 = record_at(i);
96 JsrRecord* record2 = other->record_at(i);
97 if (record1->entry_address() != record2->entry_address() ||
98 record1->return_address() != record2->return_address()) {
99 return false;
100 }
101 }
102 return true;
103 }
104
105 #if 0
106 int pos1 = 0;
107 int pos2 = 0;
108 int size1 = size();
109 int size2 = other->size();
110 while (pos1 < size1 && pos2 < size2) {
111 JsrRecord* record1 = record_at(pos1);
112 JsrRecord* record2 = other->record_at(pos2);
113 int entry1 = record1->entry_address();
114 int entry2 = record2->entry_address();
115 if (entry1 < entry2) {
116 pos1++;
117 } else if (entry1 > entry2) {
118 pos2++;
119 } else {
120 if (record1->return_address() == record2->return_address()) {
121 pos1++;
122 pos2++;
123 } else {
124 // These two JsrSets are incompatible.
125 return false;
126 }
127 }
128 }
129 // The two JsrSets agree.
130 return true;
131 #endif
132 }
133
134 // ------------------------------------------------------------------
135 // ciTypeFlow::JsrSet::insert_jsr_record
136 //
137 // Insert the given JsrRecord into the JsrSet, maintaining the order
138 // of the set and replacing any element with the same entry address.
139 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
140 int len = size();
141 int entry = record->entry_address();
142 int pos = 0;
143 for ( ; pos < len; pos++) {
144 JsrRecord* current = record_at(pos);
145 if (entry == current->entry_address()) {
146 // Stomp over this entry.
147 _set->at_put(pos, record);
148 assert(size() == len, "must be same size");
149 return;
150 } else if (entry < current->entry_address()) {
151 break;
152 }
153 }
154
155 // Insert the record into the list.
156 JsrRecord* swap = record;
157 JsrRecord* temp = NULL;
158 for ( ; pos < len; pos++) {
159 temp = _set->at(pos);
160 _set->at_put(pos, swap);
161 swap = temp;
162 }
163 _set->append(swap);
164 assert(size() == len+1, "must be larger");
165 }
166
167 // ------------------------------------------------------------------
168 // ciTypeFlow::JsrSet::remove_jsr_record
169 //
170 // Remove the JsrRecord with the given return address from the JsrSet.
171 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
172 int len = size();
173 for (int i = 0; i < len; i++) {
174 if (record_at(i)->return_address() == return_address) {
175 // We have found the proper entry. Remove it from the
176 // JsrSet and exit.
177 for (int j = i+1; j < len ; j++) {
178 _set->at_put(j-1, _set->at(j));
179 }
180 _set->trunc_to(len-1);
181 assert(size() == len-1, "must be smaller");
182 return;
183 }
184 }
185 assert(false, "verify: returning from invalid subroutine");
186 }
187
188 // ------------------------------------------------------------------
189 // ciTypeFlow::JsrSet::apply_control
190 //
191 // Apply the effect of a control-flow bytecode on the JsrSet. The
192 // only bytecodes that modify the JsrSet are jsr and ret.
193 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
194 ciBytecodeStream* str,
195 ciTypeFlow::StateVector* state) {
196 Bytecodes::Code code = str->cur_bc();
197 if (code == Bytecodes::_jsr) {
198 JsrRecord* record =
199 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
200 insert_jsr_record(record);
201 } else if (code == Bytecodes::_jsr_w) {
202 JsrRecord* record =
203 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
204 insert_jsr_record(record);
205 } else if (code == Bytecodes::_ret) {
206 Cell local = state->local(str->get_index());
207 ciType* return_address = state->type_at(local);
208 assert(return_address->is_return_address(), "verify: wrong type");
209 if (size() == 0) {
210 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
211 // This can happen when a loop is inside a finally clause (4614060).
212 analyzer->record_failure("OSR in finally clause");
213 return;
214 }
215 remove_jsr_record(return_address->as_return_address()->bci());
216 }
217 }
218
219 #ifndef PRODUCT
220 // ------------------------------------------------------------------
221 // ciTypeFlow::JsrSet::print_on
222 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
223 st->print("{ ");
224 int num_elements = size();
225 if (num_elements > 0) {
226 int i = 0;
227 for( ; i < num_elements - 1; i++) {
228 _set->at(i)->print_on(st);
229 st->print(", ");
230 }
231 _set->at(i)->print_on(st);
232 st->print(" ");
233 }
234 st->print("}");
235 }
236 #endif
237
238 // ciTypeFlow::StateVector
239 //
240 // A StateVector summarizes the type information at some point in
241 // the program.
242
243 // ------------------------------------------------------------------
244 // ciTypeFlow::StateVector::type_meet
245 //
246 // Meet two types.
247 //
248 // The semi-lattice of types use by this analysis are modeled on those
249 // of the verifier. The lattice is as follows:
250 //
251 // top_type() >= all non-extremal types >= bottom_type
252 // and
253 // Every primitive type is comparable only with itself. The meet of
254 // reference types is determined by their kind: instance class,
255 // interface, or array class. The meet of two types of the same
256 // kind is their least common ancestor. The meet of two types of
257 // different kinds is always java.lang.Object.
258 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
259 assert(t1 != t2, "checked in caller");
260 if (t1->equals(top_type())) {
261 return t2;
262 } else if (t2->equals(top_type())) {
263 return t1;
264 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
265 // Special case null_type. null_type meet any reference type T
266 // is T. null_type meet null_type is null_type.
267 if (t1->equals(null_type())) {
268 if (!t2->is_primitive_type() || t2->equals(null_type())) {
269 return t2;
270 }
271 } else if (t2->equals(null_type())) {
272 if (!t1->is_primitive_type()) {
273 return t1;
274 }
275 }
276
277 // At least one of the two types is a non-top primitive type.
278 // The other type is not equal to it. Fall to bottom.
279 return bottom_type();
280 } else {
281 // Both types are non-top non-primitive types. That is,
282 // both types are either instanceKlasses or arrayKlasses.
283 ciKlass* object_klass = analyzer->env()->Object_klass();
284 ciKlass* k1 = t1->as_klass();
285 ciKlass* k2 = t2->as_klass();
286 if (k1->equals(object_klass) || k2->equals(object_klass)) {
287 return object_klass;
288 } else if (!k1->is_loaded() || !k2->is_loaded()) {
289 // Unloaded classes fall to java.lang.Object at a merge.
290 return object_klass;
291 } else if (k1->is_interface() != k2->is_interface()) {
292 // When an interface meets a non-interface, we get Object;
293 // This is what the verifier does.
294 return object_klass;
295 } else if (k1->is_array_klass() || k2->is_array_klass()) {
296 // When an array meets a non-array, we get Object.
297 // When objArray meets typeArray, we also get Object.
298 // And when typeArray meets different typeArray, we again get Object.
299 // But when objArray meets objArray, we look carefully at element types.
300 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
301 // Meet the element types, then construct the corresponding array type.
302 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
303 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
304 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
305 // Do an easy shortcut if one type is a super of the other.
306 if (elem == elem1) {
307 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
308 return k1;
309 } else if (elem == elem2) {
310 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
311 return k2;
312 } else {
313 return ciObjArrayKlass::make(elem);
314 }
315 } else {
316 return object_klass;
317 }
318 } else {
319 // Must be two plain old instance klasses.
320 assert(k1->is_instance_klass(), "previous cases handle non-instances");
321 assert(k2->is_instance_klass(), "previous cases handle non-instances");
322 return k1->least_common_ancestor(k2);
323 }
324 }
325 }
326
327
328 // ------------------------------------------------------------------
329 // ciTypeFlow::StateVector::StateVector
330 //
331 // Build a new state vector
332 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
333 _outer = analyzer;
334 _stack_size = -1;
335 _monitor_count = -1;
336 // Allocate the _types array
337 int max_cells = analyzer->max_cells();
338 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
339 for (int i=0; i<max_cells; i++) {
340 _types[i] = top_type();
341 }
342 _trap_bci = -1;
343 _trap_index = 0;
344 }
345
346 // ------------------------------------------------------------------
347 // ciTypeFlow::get_start_state
348 //
349 // Set this vector to the method entry state.
350 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
351 StateVector* state = new StateVector(this);
352 if (is_osr_flow()) {
353 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
354 if (non_osr_flow->failing()) {
355 record_failure(non_osr_flow->failure_reason());
356 return NULL;
357 }
358 JsrSet* jsrs = new JsrSet(NULL, 16);
359 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
360 if (non_osr_block == NULL) {
361 record_failure("cannot reach OSR point");
362 return NULL;
363 }
364 // load up the non-OSR state at this point
365 non_osr_block->copy_state_into(state);
366 int non_osr_start = non_osr_block->start();
367 if (non_osr_start != start_bci()) {
368 // must flow forward from it
369 if (CITraceTypeFlow) {
370 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
371 }
372 Block* block = block_at(non_osr_start, jsrs);
373 assert(block->limit() == start_bci(), "must flow forward to start");
374 flow_block(block, state, jsrs);
375 }
376 return state;
377 // Note: The code below would be an incorrect for an OSR flow,
378 // even if it were possible for an OSR entry point to be at bci zero.
379 }
380 // "Push" the method signature into the first few locals.
381 state->set_stack_size(-max_locals());
382 if (!method()->is_static()) {
383 state->push(method()->holder());
384 assert(state->tos() == state->local(0), "");
385 }
386 for (ciSignatureStream str(method()->signature());
387 !str.at_return_type();
388 str.next()) {
389 state->push_translate(str.type());
390 }
391 // Set the rest of the locals to bottom.
392 Cell cell = state->next_cell(state->tos());
393 state->set_stack_size(0);
394 int limit = state->limit_cell();
395 for (; cell < limit; cell = state->next_cell(cell)) {
396 state->set_type_at(cell, state->bottom_type());
397 }
398 // Lock an object, if necessary.
399 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
400 return state;
401 }
402
403 // ------------------------------------------------------------------
404 // ciTypeFlow::StateVector::copy_into
405 //
406 // Copy our value into some other StateVector
407 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
408 const {
409 copy->set_stack_size(stack_size());
410 copy->set_monitor_count(monitor_count());
411 Cell limit = limit_cell();
412 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
413 copy->set_type_at(c, type_at(c));
414 }
415 }
416
417 // ------------------------------------------------------------------
418 // ciTypeFlow::StateVector::meet
419 //
420 // Meets this StateVector with another, destructively modifying this
421 // one. Returns true if any modification takes place.
422 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
423 if (monitor_count() == -1) {
424 set_monitor_count(incoming->monitor_count());
425 }
426 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
427
428 if (stack_size() == -1) {
429 set_stack_size(incoming->stack_size());
430 Cell limit = limit_cell();
431 #ifdef ASSERT
432 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
433 assert(type_at(c) == top_type(), "");
434 } }
435 #endif
436 // Make a simple copy of the incoming state.
437 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
438 set_type_at(c, incoming->type_at(c));
439 }
440 return true; // it is always different the first time
441 }
442 #ifdef ASSERT
443 if (stack_size() != incoming->stack_size()) {
444 _outer->method()->print_codes();
445 tty->print_cr("!!!! Stack size conflict");
446 tty->print_cr("Current state:");
447 print_on(tty);
448 tty->print_cr("Incoming state:");
449 ((StateVector*)incoming)->print_on(tty);
450 }
451 #endif
452 assert(stack_size() == incoming->stack_size(), "sanity");
453
454 bool different = false;
455 Cell limit = limit_cell();
456 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
457 ciType* t1 = type_at(c);
458 ciType* t2 = incoming->type_at(c);
459 if (!t1->equals(t2)) {
460 ciType* new_type = type_meet(t1, t2);
461 if (!t1->equals(new_type)) {
462 set_type_at(c, new_type);
463 different = true;
464 }
465 }
466 }
467 return different;
468 }
469
470 // ------------------------------------------------------------------
471 // ciTypeFlow::StateVector::meet_exception
472 //
473 // Meets this StateVector with another, destructively modifying this
474 // one. The incoming state is coming via an exception. Returns true
475 // if any modification takes place.
476 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
477 const ciTypeFlow::StateVector* incoming) {
478 if (monitor_count() == -1) {
479 set_monitor_count(incoming->monitor_count());
480 }
481 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
482
483 if (stack_size() == -1) {
484 set_stack_size(1);
485 }
486
487 assert(stack_size() == 1, "must have one-element stack");
488
489 bool different = false;
490
491 // Meet locals from incoming array.
492 Cell limit = local(_outer->max_locals()-1);
493 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
494 ciType* t1 = type_at(c);
495 ciType* t2 = incoming->type_at(c);
496 if (!t1->equals(t2)) {
497 ciType* new_type = type_meet(t1, t2);
498 if (!t1->equals(new_type)) {
499 set_type_at(c, new_type);
500 different = true;
501 }
502 }
503 }
504
505 // Handle stack separately. When an exception occurs, the
506 // only stack entry is the exception instance.
507 ciType* tos_type = type_at_tos();
508 if (!tos_type->equals(exc)) {
509 ciType* new_type = type_meet(tos_type, exc);
510 if (!tos_type->equals(new_type)) {
511 set_type_at_tos(new_type);
512 different = true;
513 }
514 }
515
516 return different;
517 }
518
519 // ------------------------------------------------------------------
520 // ciTypeFlow::StateVector::push_translate
521 void ciTypeFlow::StateVector::push_translate(ciType* type) {
522 BasicType basic_type = type->basic_type();
523 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
524 basic_type == T_BYTE || basic_type == T_SHORT) {
525 push_int();
526 } else {
527 push(type);
528 if (type->is_two_word()) {
529 push(half_type(type));
530 }
531 }
532 }
533
534 // ------------------------------------------------------------------
535 // ciTypeFlow::StateVector::do_aaload
536 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
537 pop_int();
538 ciObjArrayKlass* array_klass = pop_objArray();
539 if (array_klass == NULL) {
540 // Did aaload on a null reference; push a null and ignore the exception.
541 // This instruction will never continue normally. All we have to do
542 // is report a value that will meet correctly with any downstream
543 // reference types on paths that will truly be executed. This null type
544 // meets with any reference type to yield that same reference type.
545 // (The compiler will generate an unconditonal exception here.)
546 push(null_type());
547 return;
548 }
549 if (!array_klass->is_loaded()) {
550 // Only fails for some -Xcomp runs
551 trap(str, array_klass,
552 Deoptimization::make_trap_request
553 (Deoptimization::Reason_unloaded,
554 Deoptimization::Action_reinterpret));
555 return;
556 }
557 ciKlass* element_klass = array_klass->element_klass();
558 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
559 Untested("unloaded array element class in ciTypeFlow");
560 trap(str, element_klass,
561 Deoptimization::make_trap_request
562 (Deoptimization::Reason_unloaded,
563 Deoptimization::Action_reinterpret));
564 } else {
565 push_object(element_klass);
566 }
567 }
568
569
570 // ------------------------------------------------------------------
571 // ciTypeFlow::StateVector::do_checkcast
572 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
573 bool will_link;
574 ciKlass* klass = str->get_klass(will_link);
575 if (!will_link) {
576 // VM's interpreter will not load 'klass' if object is NULL.
577 // Type flow after this block may still be needed in two situations:
578 // 1) C2 uses do_null_assert() and continues compilation for later blocks
579 // 2) C2 does an OSR compile in a later block (see bug 4778368).
580 pop_object();
581 do_null_assert(klass);
582 } else {
583 pop_object();
584 push_object(klass);
585 }
586 }
587
588 // ------------------------------------------------------------------
589 // ciTypeFlow::StateVector::do_getfield
590 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
591 // could add assert here for type of object.
592 pop_object();
593 do_getstatic(str);
594 }
595
596 // ------------------------------------------------------------------
597 // ciTypeFlow::StateVector::do_getstatic
598 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
599 bool will_link;
600 ciField* field = str->get_field(will_link);
601 if (!will_link) {
602 trap(str, field->holder(), str->get_field_holder_index());
603 } else {
604 ciType* field_type = field->type();
605 if (!field_type->is_loaded()) {
606 // Normally, we need the field's type to be loaded if we are to
607 // do anything interesting with its value.
608 // We used to do this: trap(str, str->get_field_signature_index());
609 //
610 // There is one good reason not to trap here. Execution can
611 // get past this "getfield" or "getstatic" if the value of
612 // the field is null. As long as the value is null, the class
613 // does not need to be loaded! The compiler must assume that
614 // the value of the unloaded class reference is null; if the code
615 // ever sees a non-null value, loading has occurred.
616 //
617 // This actually happens often enough to be annoying. If the
618 // compiler throws an uncommon trap at this bytecode, you can
619 // get an endless loop of recompilations, when all the code
620 // needs to do is load a series of null values. Also, a trap
621 // here can make an OSR entry point unreachable, triggering the
622 // assert on non_osr_block in ciTypeFlow::get_start_state.
623 // (See bug 4379915.)
624 do_null_assert(field_type->as_klass());
625 } else {
626 push_translate(field_type);
627 }
628 }
629 }
630
631 // ------------------------------------------------------------------
632 // ciTypeFlow::StateVector::do_invoke
633 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
634 bool has_receiver) {
635 bool will_link;
636 ciMethod* method = str->get_method(will_link);
637 if (!will_link) {
638 // We weren't able to find the method.
639 ciKlass* unloaded_holder = method->holder();
640 trap(str, unloaded_holder, str->get_method_holder_index());
641 } else {
642 ciSignature* signature = method->signature();
643 ciSignatureStream sigstr(signature);
644 int arg_size = signature->size();
645 int stack_base = stack_size() - arg_size;
646 int i = 0;
647 for( ; !sigstr.at_return_type(); sigstr.next()) {
648 ciType* type = sigstr.type();
649 ciType* stack_type = type_at(stack(stack_base + i++));
650 // Do I want to check this type?
651 // assert(stack_type->is_subtype_of(type), "bad type for field value");
652 if (type->is_two_word()) {
653 ciType* stack_type2 = type_at(stack(stack_base + i++));
654 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
655 }
656 }
657 assert(arg_size == i, "must match");
658 for (int j = 0; j < arg_size; j++) {
659 pop();
660 }
661 if (has_receiver) {
662 // Check this?
663 pop_object();
664 }
665 assert(!sigstr.is_done(), "must have return type");
666 ciType* return_type = sigstr.type();
667 if (!return_type->is_void()) {
668 if (!return_type->is_loaded()) {
669 // As in do_getstatic(), generally speaking, we need the return type to
670 // be loaded if we are to do anything interesting with its value.
671 // We used to do this: trap(str, str->get_method_signature_index());
672 //
673 // We do not trap here since execution can get past this invoke if
674 // the return value is null. As long as the value is null, the class
675 // does not need to be loaded! The compiler must assume that
676 // the value of the unloaded class reference is null; if the code
677 // ever sees a non-null value, loading has occurred.
678 //
679 // See do_getstatic() for similar explanation, as well as bug 4684993.
680 do_null_assert(return_type->as_klass());
681 } else {
682 push_translate(return_type);
683 }
684 }
685 }
686 }
687
688 // ------------------------------------------------------------------
689 // ciTypeFlow::StateVector::do_jsr
690 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
691 push(ciReturnAddress::make(str->next_bci()));
692 }
693
694 // ------------------------------------------------------------------
695 // ciTypeFlow::StateVector::do_ldc
696 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
697 ciConstant con = str->get_constant();
698 BasicType basic_type = con.basic_type();
699 if (basic_type == T_ILLEGAL) {
700 // OutOfMemoryError in the CI while loading constant
701 push_null();
702 outer()->record_failure("ldc did not link");
703 return;
704 }
705 if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
706 ciObject* obj = con.as_object();
707 if (obj->is_null_object()) {
708 push_null();
709 } else if (obj->is_klass()) {
710 // The type of ldc <class> is java.lang.Class
711 push_object(outer()->env()->Class_klass());
712 } else {
713 push_object(obj->klass());
714 }
715 } else {
716 push_translate(ciType::make(basic_type));
717 }
718 }
719
720 // ------------------------------------------------------------------
721 // ciTypeFlow::StateVector::do_multianewarray
722 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
723 int dimensions = str->get_dimensions();
724 bool will_link;
725 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
726 if (!will_link) {
727 trap(str, array_klass, str->get_klass_index());
728 } else {
729 for (int i = 0; i < dimensions; i++) {
730 pop_int();
731 }
732 push_object(array_klass);
733 }
734 }
735
736 // ------------------------------------------------------------------
737 // ciTypeFlow::StateVector::do_new
738 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
739 bool will_link;
740 ciKlass* klass = str->get_klass(will_link);
741 if (!will_link) {
742 trap(str, klass, str->get_klass_index());
743 } else {
744 push_object(klass);
745 }
746 }
747
748 // ------------------------------------------------------------------
749 // ciTypeFlow::StateVector::do_newarray
750 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
751 pop_int();
752 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
753 push_object(klass);
754 }
755
756 // ------------------------------------------------------------------
757 // ciTypeFlow::StateVector::do_putfield
758 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
759 do_putstatic(str);
760 if (_trap_bci != -1) return; // unloaded field holder, etc.
761 // could add assert here for type of object.
762 pop_object();
763 }
764
765 // ------------------------------------------------------------------
766 // ciTypeFlow::StateVector::do_putstatic
767 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
768 bool will_link;
769 ciField* field = str->get_field(will_link);
770 if (!will_link) {
771 trap(str, field->holder(), str->get_field_holder_index());
772 } else {
773 ciType* field_type = field->type();
774 ciType* type = pop_value();
775 // Do I want to check this type?
776 // assert(type->is_subtype_of(field_type), "bad type for field value");
777 if (field_type->is_two_word()) {
778 ciType* type2 = pop_value();
779 assert(type2->is_two_word(), "must be 2nd half");
780 assert(type == half_type(type2), "must be 2nd half");
781 }
782 }
783 }
784
785 // ------------------------------------------------------------------
786 // ciTypeFlow::StateVector::do_ret
787 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
788 Cell index = local(str->get_index());
789
790 ciType* address = type_at(index);
791 assert(address->is_return_address(), "bad return address");
792 set_type_at(index, bottom_type());
793 }
794
795 // ------------------------------------------------------------------
796 // ciTypeFlow::StateVector::trap
797 //
798 // Stop interpretation of this path with a trap.
799 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
800 _trap_bci = str->cur_bci();
801 _trap_index = index;
802
803 // Log information about this trap:
804 CompileLog* log = outer()->env()->log();
805 if (log != NULL) {
806 int mid = log->identify(outer()->method());
807 int kid = (klass == NULL)? -1: log->identify(klass);
808 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
809 char buf[100];
810 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
811 index));
812 if (kid >= 0)
813 log->print(" klass='%d'", kid);
814 log->end_elem();
815 }
816 }
817
818 // ------------------------------------------------------------------
819 // ciTypeFlow::StateVector::do_null_assert
820 // Corresponds to graphKit::do_null_assert.
821 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
822 if (unloaded_klass->is_loaded()) {
823 // We failed to link, but we can still compute with this class,
824 // since it is loaded somewhere. The compiler will uncommon_trap
825 // if the object is not null, but the typeflow pass can not assume
826 // that the object will be null, otherwise it may incorrectly tell
827 // the parser that an object is known to be null. 4761344, 4807707
828 push_object(unloaded_klass);
829 } else {
830 // The class is not loaded anywhere. It is safe to model the
831 // null in the typestates, because we can compile in a null check
832 // which will deoptimize us if someone manages to load the
833 // class later.
834 push_null();
835 }
836 }
837
838
839 // ------------------------------------------------------------------
840 // ciTypeFlow::StateVector::apply_one_bytecode
841 //
842 // Apply the effect of one bytecode to this StateVector
843 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
844 _trap_bci = -1;
845 _trap_index = 0;
846
847 if (CITraceTypeFlow) {
848 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
849 Bytecodes::name(str->cur_bc()));
850 }
851
852 switch(str->cur_bc()) {
853 case Bytecodes::_aaload: do_aaload(str); break;
854
855 case Bytecodes::_aastore:
856 {
857 pop_object();
858 pop_int();
859 pop_objArray();
860 break;
861 }
862 case Bytecodes::_aconst_null:
863 {
864 push_null();
865 break;
866 }
867 case Bytecodes::_aload: load_local_object(str->get_index()); break;
868 case Bytecodes::_aload_0: load_local_object(0); break;
869 case Bytecodes::_aload_1: load_local_object(1); break;
870 case Bytecodes::_aload_2: load_local_object(2); break;
871 case Bytecodes::_aload_3: load_local_object(3); break;
872
873 case Bytecodes::_anewarray:
874 {
875 pop_int();
876 bool will_link;
877 ciKlass* element_klass = str->get_klass(will_link);
878 if (!will_link) {
879 trap(str, element_klass, str->get_klass_index());
880 } else {
881 push_object(ciObjArrayKlass::make(element_klass));
882 }
883 break;
884 }
885 case Bytecodes::_areturn:
886 case Bytecodes::_ifnonnull:
887 case Bytecodes::_ifnull:
888 {
889 pop_object();
890 break;
891 }
892 case Bytecodes::_monitorenter:
893 {
894 pop_object();
895 set_monitor_count(monitor_count() + 1);
896 break;
897 }
898 case Bytecodes::_monitorexit:
899 {
900 pop_object();
901 assert(monitor_count() > 0, "must be a monitor to exit from");
902 set_monitor_count(monitor_count() - 1);
903 break;
904 }
905 case Bytecodes::_arraylength:
906 {
907 pop_array();
908 push_int();
909 break;
910 }
911 case Bytecodes::_astore: store_local_object(str->get_index()); break;
912 case Bytecodes::_astore_0: store_local_object(0); break;
913 case Bytecodes::_astore_1: store_local_object(1); break;
914 case Bytecodes::_astore_2: store_local_object(2); break;
915 case Bytecodes::_astore_3: store_local_object(3); break;
916
917 case Bytecodes::_athrow:
918 {
919 NEEDS_CLEANUP;
920 pop_object();
921 break;
922 }
923 case Bytecodes::_baload:
924 case Bytecodes::_caload:
925 case Bytecodes::_iaload:
926 case Bytecodes::_saload:
927 {
928 pop_int();
929 ciTypeArrayKlass* array_klass = pop_typeArray();
930 // Put assert here for right type?
931 push_int();
932 break;
933 }
934 case Bytecodes::_bastore:
935 case Bytecodes::_castore:
936 case Bytecodes::_iastore:
937 case Bytecodes::_sastore:
938 {
939 pop_int();
940 pop_int();
941 pop_typeArray();
942 // assert here?
943 break;
944 }
945 case Bytecodes::_bipush:
946 case Bytecodes::_iconst_m1:
947 case Bytecodes::_iconst_0:
948 case Bytecodes::_iconst_1:
949 case Bytecodes::_iconst_2:
950 case Bytecodes::_iconst_3:
951 case Bytecodes::_iconst_4:
952 case Bytecodes::_iconst_5:
953 case Bytecodes::_sipush:
954 {
955 push_int();
956 break;
957 }
958 case Bytecodes::_checkcast: do_checkcast(str); break;
959
960 case Bytecodes::_d2f:
961 {
962 pop_double();
963 push_float();
964 break;
965 }
966 case Bytecodes::_d2i:
967 {
968 pop_double();
969 push_int();
970 break;
971 }
972 case Bytecodes::_d2l:
973 {
974 pop_double();
975 push_long();
976 break;
977 }
978 case Bytecodes::_dadd:
979 case Bytecodes::_ddiv:
980 case Bytecodes::_dmul:
981 case Bytecodes::_drem:
982 case Bytecodes::_dsub:
983 {
984 pop_double();
985 pop_double();
986 push_double();
987 break;
988 }
989 case Bytecodes::_daload:
990 {
991 pop_int();
992 ciTypeArrayKlass* array_klass = pop_typeArray();
993 // Put assert here for right type?
994 push_double();
995 break;
996 }
997 case Bytecodes::_dastore:
998 {
999 pop_double();
1000 pop_int();
1001 pop_typeArray();
1002 // assert here?
1003 break;
1004 }
1005 case Bytecodes::_dcmpg:
1006 case Bytecodes::_dcmpl:
1007 {
1008 pop_double();
1009 pop_double();
1010 push_int();
1011 break;
1012 }
1013 case Bytecodes::_dconst_0:
1014 case Bytecodes::_dconst_1:
1015 {
1016 push_double();
1017 break;
1018 }
1019 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1020 case Bytecodes::_dload_0: load_local_double(0); break;
1021 case Bytecodes::_dload_1: load_local_double(1); break;
1022 case Bytecodes::_dload_2: load_local_double(2); break;
1023 case Bytecodes::_dload_3: load_local_double(3); break;
1024
1025 case Bytecodes::_dneg:
1026 {
1027 pop_double();
1028 push_double();
1029 break;
1030 }
1031 case Bytecodes::_dreturn:
1032 {
1033 pop_double();
1034 break;
1035 }
1036 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1037 case Bytecodes::_dstore_0: store_local_double(0); break;
1038 case Bytecodes::_dstore_1: store_local_double(1); break;
1039 case Bytecodes::_dstore_2: store_local_double(2); break;
1040 case Bytecodes::_dstore_3: store_local_double(3); break;
1041
1042 case Bytecodes::_dup:
1043 {
1044 push(type_at_tos());
1045 break;
1046 }
1047 case Bytecodes::_dup_x1:
1048 {
1049 ciType* value1 = pop_value();
1050 ciType* value2 = pop_value();
1051 push(value1);
1052 push(value2);
1053 push(value1);
1054 break;
1055 }
1056 case Bytecodes::_dup_x2:
1057 {
1058 ciType* value1 = pop_value();
1059 ciType* value2 = pop_value();
1060 ciType* value3 = pop_value();
1061 push(value1);
1062 push(value3);
1063 push(value2);
1064 push(value1);
1065 break;
1066 }
1067 case Bytecodes::_dup2:
1068 {
1069 ciType* value1 = pop_value();
1070 ciType* value2 = pop_value();
1071 push(value2);
1072 push(value1);
1073 push(value2);
1074 push(value1);
1075 break;
1076 }
1077 case Bytecodes::_dup2_x1:
1078 {
1079 ciType* value1 = pop_value();
1080 ciType* value2 = pop_value();
1081 ciType* value3 = pop_value();
1082 push(value2);
1083 push(value1);
1084 push(value3);
1085 push(value2);
1086 push(value1);
1087 break;
1088 }
1089 case Bytecodes::_dup2_x2:
1090 {
1091 ciType* value1 = pop_value();
1092 ciType* value2 = pop_value();
1093 ciType* value3 = pop_value();
1094 ciType* value4 = pop_value();
1095 push(value2);
1096 push(value1);
1097 push(value4);
1098 push(value3);
1099 push(value2);
1100 push(value1);
1101 break;
1102 }
1103 case Bytecodes::_f2d:
1104 {
1105 pop_float();
1106 push_double();
1107 break;
1108 }
1109 case Bytecodes::_f2i:
1110 {
1111 pop_float();
1112 push_int();
1113 break;
1114 }
1115 case Bytecodes::_f2l:
1116 {
1117 pop_float();
1118 push_long();
1119 break;
1120 }
1121 case Bytecodes::_fadd:
1122 case Bytecodes::_fdiv:
1123 case Bytecodes::_fmul:
1124 case Bytecodes::_frem:
1125 case Bytecodes::_fsub:
1126 {
1127 pop_float();
1128 pop_float();
1129 push_float();
1130 break;
1131 }
1132 case Bytecodes::_faload:
1133 {
1134 pop_int();
1135 ciTypeArrayKlass* array_klass = pop_typeArray();
1136 // Put assert here.
1137 push_float();
1138 break;
1139 }
1140 case Bytecodes::_fastore:
1141 {
1142 pop_float();
1143 pop_int();
1144 ciTypeArrayKlass* array_klass = pop_typeArray();
1145 // Put assert here.
1146 break;
1147 }
1148 case Bytecodes::_fcmpg:
1149 case Bytecodes::_fcmpl:
1150 {
1151 pop_float();
1152 pop_float();
1153 push_int();
1154 break;
1155 }
1156 case Bytecodes::_fconst_0:
1157 case Bytecodes::_fconst_1:
1158 case Bytecodes::_fconst_2:
1159 {
1160 push_float();
1161 break;
1162 }
1163 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1164 case Bytecodes::_fload_0: load_local_float(0); break;
1165 case Bytecodes::_fload_1: load_local_float(1); break;
1166 case Bytecodes::_fload_2: load_local_float(2); break;
1167 case Bytecodes::_fload_3: load_local_float(3); break;
1168
1169 case Bytecodes::_fneg:
1170 {
1171 pop_float();
1172 push_float();
1173 break;
1174 }
1175 case Bytecodes::_freturn:
1176 {
1177 pop_float();
1178 break;
1179 }
1180 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1181 case Bytecodes::_fstore_0: store_local_float(0); break;
1182 case Bytecodes::_fstore_1: store_local_float(1); break;
1183 case Bytecodes::_fstore_2: store_local_float(2); break;
1184 case Bytecodes::_fstore_3: store_local_float(3); break;
1185
1186 case Bytecodes::_getfield: do_getfield(str); break;
1187 case Bytecodes::_getstatic: do_getstatic(str); break;
1188
1189 case Bytecodes::_goto:
1190 case Bytecodes::_goto_w:
1191 case Bytecodes::_nop:
1192 case Bytecodes::_return:
1193 {
1194 // do nothing.
1195 break;
1196 }
1197 case Bytecodes::_i2b:
1198 case Bytecodes::_i2c:
1199 case Bytecodes::_i2s:
1200 case Bytecodes::_ineg:
1201 {
1202 pop_int();
1203 push_int();
1204 break;
1205 }
1206 case Bytecodes::_i2d:
1207 {
1208 pop_int();
1209 push_double();
1210 break;
1211 }
1212 case Bytecodes::_i2f:
1213 {
1214 pop_int();
1215 push_float();
1216 break;
1217 }
1218 case Bytecodes::_i2l:
1219 {
1220 pop_int();
1221 push_long();
1222 break;
1223 }
1224 case Bytecodes::_iadd:
1225 case Bytecodes::_iand:
1226 case Bytecodes::_idiv:
1227 case Bytecodes::_imul:
1228 case Bytecodes::_ior:
1229 case Bytecodes::_irem:
1230 case Bytecodes::_ishl:
1231 case Bytecodes::_ishr:
1232 case Bytecodes::_isub:
1233 case Bytecodes::_iushr:
1234 case Bytecodes::_ixor:
1235 {
1236 pop_int();
1237 pop_int();
1238 push_int();
1239 break;
1240 }
1241 case Bytecodes::_if_acmpeq:
1242 case Bytecodes::_if_acmpne:
1243 {
1244 pop_object();
1245 pop_object();
1246 break;
1247 }
1248 case Bytecodes::_if_icmpeq:
1249 case Bytecodes::_if_icmpge:
1250 case Bytecodes::_if_icmpgt:
1251 case Bytecodes::_if_icmple:
1252 case Bytecodes::_if_icmplt:
1253 case Bytecodes::_if_icmpne:
1254 {
1255 pop_int();
1256 pop_int();
1257 break;
1258 }
1259 case Bytecodes::_ifeq:
1260 case Bytecodes::_ifle:
1261 case Bytecodes::_iflt:
1262 case Bytecodes::_ifge:
1263 case Bytecodes::_ifgt:
1264 case Bytecodes::_ifne:
1265 case Bytecodes::_ireturn:
1266 case Bytecodes::_lookupswitch:
1267 case Bytecodes::_tableswitch:
1268 {
1269 pop_int();
1270 break;
1271 }
1272 case Bytecodes::_iinc:
1273 {
1274 check_int(local(str->get_index()));
1275 break;
1276 }
1277 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1278 case Bytecodes::_iload_0: load_local_int(0); break;
1279 case Bytecodes::_iload_1: load_local_int(1); break;
1280 case Bytecodes::_iload_2: load_local_int(2); break;
1281 case Bytecodes::_iload_3: load_local_int(3); break;
1282
1283 case Bytecodes::_instanceof:
1284 {
1285 // Check for uncommon trap:
1286 do_checkcast(str);
1287 pop_object();
1288 push_int();
1289 break;
1290 }
1291 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1292 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1293 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1294
1295 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1296
1297 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1298 case Bytecodes::_istore_0: store_local_int(0); break;
1299 case Bytecodes::_istore_1: store_local_int(1); break;
1300 case Bytecodes::_istore_2: store_local_int(2); break;
1301 case Bytecodes::_istore_3: store_local_int(3); break;
1302
1303 case Bytecodes::_jsr:
1304 case Bytecodes::_jsr_w: do_jsr(str); break;
1305
1306 case Bytecodes::_l2d:
1307 {
1308 pop_long();
1309 push_double();
1310 break;
1311 }
1312 case Bytecodes::_l2f:
1313 {
1314 pop_long();
1315 push_float();
1316 break;
1317 }
1318 case Bytecodes::_l2i:
1319 {
1320 pop_long();
1321 push_int();
1322 break;
1323 }
1324 case Bytecodes::_ladd:
1325 case Bytecodes::_land:
1326 case Bytecodes::_ldiv:
1327 case Bytecodes::_lmul:
1328 case Bytecodes::_lor:
1329 case Bytecodes::_lrem:
1330 case Bytecodes::_lsub:
1331 case Bytecodes::_lxor:
1332 {
1333 pop_long();
1334 pop_long();
1335 push_long();
1336 break;
1337 }
1338 case Bytecodes::_laload:
1339 {
1340 pop_int();
1341 ciTypeArrayKlass* array_klass = pop_typeArray();
1342 // Put assert here for right type?
1343 push_long();
1344 break;
1345 }
1346 case Bytecodes::_lastore:
1347 {
1348 pop_long();
1349 pop_int();
1350 pop_typeArray();
1351 // assert here?
1352 break;
1353 }
1354 case Bytecodes::_lcmp:
1355 {
1356 pop_long();
1357 pop_long();
1358 push_int();
1359 break;
1360 }
1361 case Bytecodes::_lconst_0:
1362 case Bytecodes::_lconst_1:
1363 {
1364 push_long();
1365 break;
1366 }
1367 case Bytecodes::_ldc:
1368 case Bytecodes::_ldc_w:
1369 case Bytecodes::_ldc2_w:
1370 {
1371 do_ldc(str);
1372 break;
1373 }
1374
1375 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1376 case Bytecodes::_lload_0: load_local_long(0); break;
1377 case Bytecodes::_lload_1: load_local_long(1); break;
1378 case Bytecodes::_lload_2: load_local_long(2); break;
1379 case Bytecodes::_lload_3: load_local_long(3); break;
1380
1381 case Bytecodes::_lneg:
1382 {
1383 pop_long();
1384 push_long();
1385 break;
1386 }
1387 case Bytecodes::_lreturn:
1388 {
1389 pop_long();
1390 break;
1391 }
1392 case Bytecodes::_lshl:
1393 case Bytecodes::_lshr:
1394 case Bytecodes::_lushr:
1395 {
1396 pop_int();
1397 pop_long();
1398 push_long();
1399 break;
1400 }
1401 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1402 case Bytecodes::_lstore_0: store_local_long(0); break;
1403 case Bytecodes::_lstore_1: store_local_long(1); break;
1404 case Bytecodes::_lstore_2: store_local_long(2); break;
1405 case Bytecodes::_lstore_3: store_local_long(3); break;
1406
1407 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1408
1409 case Bytecodes::_new: do_new(str); break;
1410
1411 case Bytecodes::_newarray: do_newarray(str); break;
1412
1413 case Bytecodes::_pop:
1414 {
1415 pop();
1416 break;
1417 }
1418 case Bytecodes::_pop2:
1419 {
1420 pop();
1421 pop();
1422 break;
1423 }
1424
1425 case Bytecodes::_putfield: do_putfield(str); break;
1426 case Bytecodes::_putstatic: do_putstatic(str); break;
1427
1428 case Bytecodes::_ret: do_ret(str); break;
1429
1430 case Bytecodes::_swap:
1431 {
1432 ciType* value1 = pop_value();
1433 ciType* value2 = pop_value();
1434 push(value1);
1435 push(value2);
1436 break;
1437 }
1438 case Bytecodes::_wide:
1439 default:
1440 {
1441 // The iterator should skip this.
1442 ShouldNotReachHere();
1443 break;
1444 }
1445 }
1446
1447 if (CITraceTypeFlow) {
1448 print_on(tty);
1449 }
1450
1451 return (_trap_bci != -1);
1452 }
1453
1454 #ifndef PRODUCT
1455 // ------------------------------------------------------------------
1456 // ciTypeFlow::StateVector::print_cell_on
1457 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1458 ciType* type = type_at(c);
1459 if (type == top_type()) {
1460 st->print("top");
1461 } else if (type == bottom_type()) {
1462 st->print("bottom");
1463 } else if (type == null_type()) {
1464 st->print("null");
1465 } else if (type == long2_type()) {
1466 st->print("long2");
1467 } else if (type == double2_type()) {
1468 st->print("double2");
1469 } else if (is_int(type)) {
1470 st->print("int");
1471 } else if (is_long(type)) {
1472 st->print("long");
1473 } else if (is_float(type)) {
1474 st->print("float");
1475 } else if (is_double(type)) {
1476 st->print("double");
1477 } else if (type->is_return_address()) {
1478 st->print("address(%d)", type->as_return_address()->bci());
1479 } else {
1480 if (type->is_klass()) {
1481 type->as_klass()->name()->print_symbol_on(st);
1482 } else {
1483 st->print("UNEXPECTED TYPE");
1484 type->print();
1485 }
1486 }
1487 }
1488
1489 // ------------------------------------------------------------------
1490 // ciTypeFlow::StateVector::print_on
1491 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1492 int num_locals = _outer->max_locals();
1493 int num_stack = stack_size();
1494 int num_monitors = monitor_count();
1495 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1496 if (num_stack >= 0) {
1497 int i;
1498 for (i = 0; i < num_locals; i++) {
1499 st->print(" local %2d : ", i);
1500 print_cell_on(st, local(i));
1501 st->cr();
1502 }
1503 for (i = 0; i < num_stack; i++) {
1504 st->print(" stack %2d : ", i);
1505 print_cell_on(st, stack(i));
1506 st->cr();
1507 }
1508 }
1509 }
1510 #endif
1511
1512 // ciTypeFlow::Block
1513 //
1514 // A basic block.
1515
1516 // ------------------------------------------------------------------
1517 // ciTypeFlow::Block::Block
1518 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1519 ciBlock *ciblk,
1520 ciTypeFlow::JsrSet* jsrs) {
1521 _ciblock = ciblk;
1522 _exceptions = NULL;
1523 _exc_klasses = NULL;
1524 _successors = NULL;
1525 _state = new (outer->arena()) StateVector(outer);
1526 JsrSet* new_jsrs =
1527 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1528 jsrs->copy_into(new_jsrs);
1529 _jsrs = new_jsrs;
1530 _next = NULL;
1531 _on_work_list = false;
1532 _pre_order = -1; assert(!has_pre_order(), "");
1533 _private_copy = false;
1534 _trap_bci = -1;
1535 _trap_index = 0;
1536
1537 if (CITraceTypeFlow) {
1538 tty->print_cr(">> Created new block");
1539 print_on(tty);
1540 }
1541
1542 assert(this->outer() == outer, "outer link set up");
1543 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1544 }
1545
1546 // ------------------------------------------------------------------
1547 // ciTypeFlow::Block::clone_loop_head
1548 //
1549 ciTypeFlow::Block*
1550 ciTypeFlow::Block::clone_loop_head(ciTypeFlow* analyzer,
1551 int branch_bci,
1552 ciTypeFlow::Block* target,
1553 ciTypeFlow::JsrSet* jsrs) {
1554 // Loop optimizations are not performed on Tier1 compiles. Do nothing.
1555 if (analyzer->env()->comp_level() < CompLevel_full_optimization) {
1556 return target;
1557 }
1558
1559 // The current block ends with a branch.
1560 //
1561 // If the target block appears to be the test-clause of a for loop, and
1562 // it is not too large, and it has not yet been cloned, clone it.
1563 // The pre-existing copy becomes the private clone used only by
1564 // the initial iteration of the loop. (We know we are simulating
1565 // the initial iteration right now, since we have never calculated
1566 // successors before for this block.)
1567
1568 if (branch_bci <= start()
1569 && (target->limit() - target->start()) <= CICloneLoopTestLimit
1570 && target->private_copy_count() == 0) {
1571 // Setting the private_copy bit ensures that the target block cannot be
1572 // reached by any other paths, such as fall-in from the loop body.
1573 // The private copy will be accessible only on successor lists
1574 // created up to this point.
1575 target->set_private_copy(true);
1576 if (CITraceTypeFlow) {
1577 tty->print(">> Cloning a test-clause block ");
1578 print_value_on(tty);
1579 tty->cr();
1580 }
1581 // If the target is the current block, then later on a new copy of the
1582 // target block will be created when its bytecodes are reached by
1583 // an alternate path. (This is the case for loops with the loop
1584 // head at the bci-wise bottom of the loop, as with pre-1.4.2 javac.)
1585 //
1586 // Otherwise, duplicate the target block now and use it immediately.
1587 // (The case for loops with the loop head at the bci-wise top of the
1588 // loop, as with 1.4.2 javac.)
1589 //
1590 // In either case, the new copy of the block will remain public.
1591 if (target != this) {
1592 target = analyzer->block_at(branch_bci, jsrs);
1593 }
1594 }
1595 return target;
1596 }
1597
1598 // ------------------------------------------------------------------
1599 // ciTypeFlow::Block::successors
1600 //
1601 // Get the successors for this Block.
1602 GrowableArray<ciTypeFlow::Block*>*
1603 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1604 ciTypeFlow::StateVector* state,
1605 ciTypeFlow::JsrSet* jsrs) {
1606 if (_successors == NULL) {
1607 if (CITraceTypeFlow) {
1608 tty->print(">> Computing successors for block ");
1609 print_value_on(tty);
1610 tty->cr();
1611 }
1612
1613 ciTypeFlow* analyzer = outer();
1614 Arena* arena = analyzer->arena();
1615 Block* block = NULL;
1616 bool has_successor = !has_trap() &&
1617 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1618 if (!has_successor) {
1619 _successors =
1620 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1621 // No successors
1622 } else if (control() == ciBlock::fall_through_bci) {
1623 assert(str->cur_bci() == limit(), "bad block end");
1624 // This block simply falls through to the next.
1625 _successors =
1626 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1627
1628 Block* block = analyzer->block_at(limit(), _jsrs);
1629 assert(_successors->length() == FALL_THROUGH, "");
1630 _successors->append(block);
1631 } else {
1632 int current_bci = str->cur_bci();
1633 int next_bci = str->next_bci();
1634 int branch_bci = -1;
1635 Block* target = NULL;
1636 assert(str->next_bci() == limit(), "bad block end");
1637 // This block is not a simple fall-though. Interpret
1638 // the current bytecode to find our successors.
1639 switch (str->cur_bc()) {
1640 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1641 case Bytecodes::_iflt: case Bytecodes::_ifge:
1642 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1643 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1644 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1645 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1646 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1647 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1648 // Our successors are the branch target and the next bci.
1649 branch_bci = str->get_dest();
1650 clone_loop_head(analyzer, branch_bci, this, jsrs);
1651 _successors =
1652 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1653 assert(_successors->length() == IF_NOT_TAKEN, "");
1654 _successors->append(analyzer->block_at(next_bci, jsrs));
1655 assert(_successors->length() == IF_TAKEN, "");
1656 _successors->append(analyzer->block_at(branch_bci, jsrs));
1657 break;
1658
1659 case Bytecodes::_goto:
1660 branch_bci = str->get_dest();
1661 _successors =
1662 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1663 assert(_successors->length() == GOTO_TARGET, "");
1664 target = analyzer->block_at(branch_bci, jsrs);
1665 // If the target block has not been visited yet, and looks like
1666 // a two-way branch, attempt to clone it if it is a loop head.
1667 if (target->_successors != NULL
1668 && target->_successors->length() == (IF_TAKEN + 1)) {
1669 target = clone_loop_head(analyzer, branch_bci, target, jsrs);
1670 }
1671 _successors->append(target);
1672 break;
1673
1674 case Bytecodes::_jsr:
1675 branch_bci = str->get_dest();
1676 _successors =
1677 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1678 assert(_successors->length() == GOTO_TARGET, "");
1679 _successors->append(analyzer->block_at(branch_bci, jsrs));
1680 break;
1681
1682 case Bytecodes::_goto_w:
1683 case Bytecodes::_jsr_w:
1684 _successors =
1685 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1686 assert(_successors->length() == GOTO_TARGET, "");
1687 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1688 break;
1689
1690 case Bytecodes::_tableswitch: {
1691 Bytecode_tableswitch *tableswitch =
1692 Bytecode_tableswitch_at(str->cur_bcp());
1693
1694 int len = tableswitch->length();
1695 _successors =
1696 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1697 int bci = current_bci + tableswitch->default_offset();
1698 Block* block = analyzer->block_at(bci, jsrs);
1699 assert(_successors->length() == SWITCH_DEFAULT, "");
1700 _successors->append(block);
1701 while (--len >= 0) {
1702 int bci = current_bci + tableswitch->dest_offset_at(len);
1703 block = analyzer->block_at(bci, jsrs);
1704 assert(_successors->length() >= SWITCH_CASES, "");
1705 _successors->append_if_missing(block);
1706 }
1707 break;
1708 }
1709
1710 case Bytecodes::_lookupswitch: {
1711 Bytecode_lookupswitch *lookupswitch =
1712 Bytecode_lookupswitch_at(str->cur_bcp());
1713
1714 int npairs = lookupswitch->number_of_pairs();
1715 _successors =
1716 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1717 int bci = current_bci + lookupswitch->default_offset();
1718 Block* block = analyzer->block_at(bci, jsrs);
1719 assert(_successors->length() == SWITCH_DEFAULT, "");
1720 _successors->append(block);
1721 while(--npairs >= 0) {
1722 LookupswitchPair *pair = lookupswitch->pair_at(npairs);
1723 int bci = current_bci + pair->offset();
1724 Block* block = analyzer->block_at(bci, jsrs);
1725 assert(_successors->length() >= SWITCH_CASES, "");
1726 _successors->append_if_missing(block);
1727 }
1728 break;
1729 }
1730
1731 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1732 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1733 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1734 case Bytecodes::_return:
1735 _successors =
1736 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1737 // No successors
1738 break;
1739
1740 case Bytecodes::_ret: {
1741 _successors =
1742 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1743
1744 Cell local = state->local(str->get_index());
1745 ciType* return_address = state->type_at(local);
1746 assert(return_address->is_return_address(), "verify: wrong type");
1747 int bci = return_address->as_return_address()->bci();
1748 assert(_successors->length() == GOTO_TARGET, "");
1749 _successors->append(analyzer->block_at(bci, jsrs));
1750 break;
1751 }
1752
1753 case Bytecodes::_wide:
1754 default:
1755 ShouldNotReachHere();
1756 break;
1757 }
1758 }
1759 }
1760 return _successors;
1761 }
1762
1763 // ------------------------------------------------------------------
1764 // ciTypeFlow::Block:compute_exceptions
1765 //
1766 // Compute the exceptional successors and types for this Block.
1767 void ciTypeFlow::Block::compute_exceptions() {
1768 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1769
1770 if (CITraceTypeFlow) {
1771 tty->print(">> Computing exceptions for block ");
1772 print_value_on(tty);
1773 tty->cr();
1774 }
1775
1776 ciTypeFlow* analyzer = outer();
1777 Arena* arena = analyzer->arena();
1778
1779 // Any bci in the block will do.
1780 ciExceptionHandlerStream str(analyzer->method(), start());
1781
1782 // Allocate our growable arrays.
1783 int exc_count = str.count();
1784 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1785 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1786 0, NULL);
1787
1788 for ( ; !str.is_done(); str.next()) {
1789 ciExceptionHandler* handler = str.handler();
1790 int bci = handler->handler_bci();
1791 ciInstanceKlass* klass = NULL;
1792 if (bci == -1) {
1793 // There is no catch all. It is possible to exit the method.
1794 break;
1795 }
1796 if (handler->is_catch_all()) {
1797 klass = analyzer->env()->Throwable_klass();
1798 } else {
1799 klass = handler->catch_klass();
1800 }
1801 _exceptions->append(analyzer->block_at(bci, _jsrs));
1802 _exc_klasses->append(klass);
1803 }
1804 }
1805
1806 // ------------------------------------------------------------------
1807 // ciTypeFlow::Block::is_simpler_than
1808 //
1809 // A relation used to order our work list. We work on a block earlier
1810 // if it has a smaller jsr stack or it occurs earlier in the program
1811 // text.
1812 //
1813 // Note: maybe we should redo this functionality to make blocks
1814 // which correspond to exceptions lower priority.
1815 bool ciTypeFlow::Block::is_simpler_than(ciTypeFlow::Block* other) {
1816 if (other == NULL) {
1817 return true;
1818 } else {
1819 int size1 = _jsrs->size();
1820 int size2 = other->_jsrs->size();
1821 if (size1 < size2) {
1822 return true;
1823 } else if (size2 < size1) {
1824 return false;
1825 } else {
1826 #if 0
1827 if (size1 > 0) {
1828 int r1 = _jsrs->record_at(0)->return_address();
1829 int r2 = _jsrs->record_at(0)->return_address();
1830 if (r1 < r2) {
1831 return true;
1832 } else if (r2 < r1) {
1833 return false;
1834 } else {
1835 int e1 = _jsrs->record_at(0)->return_address();
1836 int e2 = _jsrs->record_at(0)->return_address();
1837 if (e1 < e2) {
1838 return true;
1839 } else if (e2 < e1) {
1840 return false;
1841 }
1842 }
1843 }
1844 #endif
1845 return (start() <= other->start());
1846 }
1847 }
1848 }
1849
1850 // ------------------------------------------------------------------
1851 // ciTypeFlow::Block::set_private_copy
1852 // Use this only to make a pre-existing public block into a private copy.
1853 void ciTypeFlow::Block::set_private_copy(bool z) {
1854 assert(z || (z == is_private_copy()), "cannot make a private copy public");
1855 _private_copy = z;
1856 }
1857
1858 #ifndef PRODUCT
1859 // ------------------------------------------------------------------
1860 // ciTypeFlow::Block::print_value_on
1861 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1862 if (has_pre_order()) st->print("#%-2d ", pre_order());
1863 st->print("[%d - %d)", start(), limit());
1864 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1865 if (is_private_copy()) st->print("/private_copy");
1866 }
1867
1868 // ------------------------------------------------------------------
1869 // ciTypeFlow::Block::print_on
1870 void ciTypeFlow::Block::print_on(outputStream* st) const {
1871 if ((Verbose || WizardMode)) {
1872 outer()->method()->print_codes_on(start(), limit(), st);
1873 }
1874 st->print_cr(" ==================================================== ");
1875 st->print (" ");
1876 print_value_on(st);
1877 st->cr();
1878 _state->print_on(st);
1879 if (_successors == NULL) {
1880 st->print_cr(" No successor information");
1881 } else {
1882 int num_successors = _successors->length();
1883 st->print_cr(" Successors : %d", num_successors);
1884 for (int i = 0; i < num_successors; i++) {
1885 Block* successor = _successors->at(i);
1886 st->print(" ");
1887 successor->print_value_on(st);
1888 st->cr();
1889 }
1890 }
1891 if (_exceptions == NULL) {
1892 st->print_cr(" No exception information");
1893 } else {
1894 int num_exceptions = _exceptions->length();
1895 st->print_cr(" Exceptions : %d", num_exceptions);
1896 for (int i = 0; i < num_exceptions; i++) {
1897 Block* exc_succ = _exceptions->at(i);
1898 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1899 st->print(" ");
1900 exc_succ->print_value_on(st);
1901 st->print(" -- ");
1902 exc_klass->name()->print_symbol_on(st);
1903 st->cr();
1904 }
1905 }
1906 if (has_trap()) {
1907 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1908 }
1909 st->print_cr(" ==================================================== ");
1910 }
1911 #endif
1912
1913 // ciTypeFlow
1914 //
1915 // This is a pass over the bytecodes which computes the following:
1916 // basic block structure
1917 // interpreter type-states (a la the verifier)
1918
1919 // ------------------------------------------------------------------
1920 // ciTypeFlow::ciTypeFlow
1921 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
1922 _env = env;
1923 _method = method;
1924 _methodBlocks = method->get_method_blocks();
1925 _max_locals = method->max_locals();
1926 _max_stack = method->max_stack();
1927 _code_size = method->code_size();
1928 _osr_bci = osr_bci;
1929 _failure_reason = NULL;
1930 assert(start_bci() >= 0 && start_bci() < code_size() , "correct osr_bci argument");
1931
1932 _work_list = NULL;
1933 _next_pre_order = 0;
1934
1935 _ciblock_count = _methodBlocks->num_blocks();
1936 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
1937 for (int i = 0; i < _ciblock_count; i++) {
1938 _idx_to_blocklist[i] = NULL;
1939 }
1940 _block_map = NULL; // until all blocks are seen
1941 _jsr_count = 0;
1942 _jsr_records = NULL;
1943 }
1944
1945 // ------------------------------------------------------------------
1946 // ciTypeFlow::work_list_next
1947 //
1948 // Get the next basic block from our work list.
1949 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
1950 assert(!work_list_empty(), "work list must not be empty");
1951 Block* next_block = _work_list;
1952 _work_list = next_block->next();
1953 next_block->set_next(NULL);
1954 next_block->set_on_work_list(false);
1955 if (!next_block->has_pre_order()) {
1956 // Assign "pre_order" as each new block is taken from the work list.
1957 // This number may be used by following phases to order block visits.
1958 assert(!have_block_count(), "must not have mapped blocks yet")
1959 next_block->set_pre_order(_next_pre_order++);
1960 }
1961 return next_block;
1962 }
1963
1964 // ------------------------------------------------------------------
1965 // ciTypeFlow::add_to_work_list
1966 //
1967 // Add a basic block to our work list.
1968 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
1969 assert(!block->is_on_work_list(), "must not already be on work list");
1970
1971 if (CITraceTypeFlow) {
1972 tty->print(">> Adding block%s ", block->has_pre_order() ? " (again)" : "");
1973 block->print_value_on(tty);
1974 tty->print_cr(" to the work list : ");
1975 }
1976
1977 block->set_on_work_list(true);
1978 if (block->is_simpler_than(_work_list)) {
1979 block->set_next(_work_list);
1980 _work_list = block;
1981 } else {
1982 Block *temp = _work_list;
1983 while (!block->is_simpler_than(temp->next())) {
1984 if (CITraceTypeFlow) {
1985 tty->print(".");
1986 }
1987 temp = temp->next();
1988 }
1989 block->set_next(temp->next());
1990 temp->set_next(block);
1991 }
1992 if (CITraceTypeFlow) {
1993 tty->cr();
1994 }
1995 }
1996
1997 // ------------------------------------------------------------------
1998 // ciTypeFlow::block_at
1999 //
2000 // Return the block beginning at bci which has a JsrSet compatible
2001 // with jsrs.
2002 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2003 // First find the right ciBlock.
2004 if (CITraceTypeFlow) {
2005 tty->print(">> Requesting block for %d/", bci);
2006 jsrs->print_on(tty);
2007 tty->cr();
2008 }
2009
2010 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2011 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2012 Block* block = get_block_for(ciblk->index(), jsrs, option);
2013
2014 assert(block == NULL? (option == no_create): block->is_private_copy() == (option == create_private_copy), "create option consistent with result");
2015
2016 if (CITraceTypeFlow) {
2017 if (block != NULL) {
2018 tty->print(">> Found block ");
2019 block->print_value_on(tty);
2020 tty->cr();
2021 } else {
2022 tty->print_cr(">> No such block.");
2023 }
2024 }
2025
2026 return block;
2027 }
2028
2029 // ------------------------------------------------------------------
2030 // ciTypeFlow::make_jsr_record
2031 //
2032 // Make a JsrRecord for a given (entry, return) pair, if such a record
2033 // does not already exist.
2034 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2035 int return_address) {
2036 if (_jsr_records == NULL) {
2037 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2038 _jsr_count,
2039 0,
2040 NULL);
2041 }
2042 JsrRecord* record = NULL;
2043 int len = _jsr_records->length();
2044 for (int i = 0; i < len; i++) {
2045 JsrRecord* record = _jsr_records->at(i);
2046 if (record->entry_address() == entry_address &&
2047 record->return_address() == return_address) {
2048 return record;
2049 }
2050 }
2051
2052 record = new (arena()) JsrRecord(entry_address, return_address);
2053 _jsr_records->append(record);
2054 return record;
2055 }
2056
2057 // ------------------------------------------------------------------
2058 // ciTypeFlow::flow_exceptions
2059 //
2060 // Merge the current state into all exceptional successors at the
2061 // current point in the code.
2062 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2063 GrowableArray<ciInstanceKlass*>* exc_klasses,
2064 ciTypeFlow::StateVector* state) {
2065 int len = exceptions->length();
2066 assert(exc_klasses->length() == len, "must have same length");
2067 for (int i = 0; i < len; i++) {
2068 Block* block = exceptions->at(i);
2069 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2070
2071 if (!exception_klass->is_loaded()) {
2072 // Do not compile any code for unloaded exception types.
2073 // Following compiler passes are responsible for doing this also.
2074 continue;
2075 }
2076
2077 if (block->meet_exception(exception_klass, state)) {
2078 // Block was modified. Add it to the work list.
2079 if (!block->is_on_work_list()) {
2080 add_to_work_list(block);
2081 }
2082 }
2083 }
2084 }
2085
2086 // ------------------------------------------------------------------
2087 // ciTypeFlow::flow_successors
2088 //
2089 // Merge the current state into all successors at the current point
2090 // in the code.
2091 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2092 ciTypeFlow::StateVector* state) {
2093 int len = successors->length();
2094 for (int i = 0; i < len; i++) {
2095 Block* block = successors->at(i);
2096 if (block->meet(state)) {
2097 // Block was modified. Add it to the work list.
2098 if (!block->is_on_work_list()) {
2099 add_to_work_list(block);
2100 }
2101 }
2102 }
2103 }
2104
2105 // ------------------------------------------------------------------
2106 // ciTypeFlow::can_trap
2107 //
2108 // Tells if a given instruction is able to generate an exception edge.
2109 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2110 // Cf. GenerateOopMap::do_exception_edge.
2111 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2112
2113 switch (str.cur_bc()) {
2114 case Bytecodes::_ldc:
2115 case Bytecodes::_ldc_w:
2116 case Bytecodes::_ldc2_w:
2117 case Bytecodes::_aload_0:
2118 // These bytecodes can trap for rewriting. We need to assume that
2119 // they do not throw exceptions to make the monitor analysis work.
2120 return false;
2121
2122 case Bytecodes::_ireturn:
2123 case Bytecodes::_lreturn:
2124 case Bytecodes::_freturn:
2125 case Bytecodes::_dreturn:
2126 case Bytecodes::_areturn:
2127 case Bytecodes::_return:
2128 // We can assume the monitor stack is empty in this analysis.
2129 return false;
2130
2131 case Bytecodes::_monitorexit:
2132 // We can assume monitors are matched in this analysis.
2133 return false;
2134 }
2135
2136 return true;
2137 }
2138
2139
2140 // ------------------------------------------------------------------
2141 // ciTypeFlow::flow_block
2142 //
2143 // Interpret the effects of the bytecodes on the incoming state
2144 // vector of a basic block. Push the changed state to succeeding
2145 // basic blocks.
2146 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2147 ciTypeFlow::StateVector* state,
2148 ciTypeFlow::JsrSet* jsrs) {
2149 if (CITraceTypeFlow) {
2150 tty->print("\n>> ANALYZING BLOCK : ");
2151 tty->cr();
2152 block->print_on(tty);
2153 }
2154 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2155
2156 int start = block->start();
2157 int limit = block->limit();
2158 int control = block->control();
2159 if (control != ciBlock::fall_through_bci) {
2160 limit = control;
2161 }
2162
2163 // Grab the state from the current block.
2164 block->copy_state_into(state);
2165
2166 GrowableArray<Block*>* exceptions = block->exceptions();
2167 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2168 bool has_exceptions = exceptions->length() > 0;
2169
2170 ciBytecodeStream str(method());
2171 str.reset_to_bci(start);
2172 Bytecodes::Code code;
2173 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2174 str.cur_bci() < limit) {
2175 // Check for exceptional control flow from this point.
2176 if (has_exceptions && can_trap(str)) {
2177 flow_exceptions(exceptions, exc_klasses, state);
2178 }
2179 // Apply the effects of the current bytecode to our state.
2180 bool res = state->apply_one_bytecode(&str);
2181
2182 // Watch for bailouts.
2183 if (failing()) return;
2184
2185 if (res) {
2186
2187 // We have encountered a trap. Record it in this block.
2188 block->set_trap(state->trap_bci(), state->trap_index());
2189
2190 if (CITraceTypeFlow) {
2191 tty->print_cr(">> Found trap");
2192 block->print_on(tty);
2193 }
2194
2195 // Record (no) successors.
2196 block->successors(&str, state, jsrs);
2197
2198 // Discontinue interpretation of this Block.
2199 return;
2200 }
2201 }
2202
2203 GrowableArray<Block*>* successors = NULL;
2204 if (control != ciBlock::fall_through_bci) {
2205 // Check for exceptional control flow from this point.
2206 if (has_exceptions && can_trap(str)) {
2207 flow_exceptions(exceptions, exc_klasses, state);
2208 }
2209
2210 // Fix the JsrSet to reflect effect of the bytecode.
2211 block->copy_jsrs_into(jsrs);
2212 jsrs->apply_control(this, &str, state);
2213
2214 // Find successor edges based on old state and new JsrSet.
2215 successors = block->successors(&str, state, jsrs);
2216
2217 // Apply the control changes to the state.
2218 state->apply_one_bytecode(&str);
2219 } else {
2220 // Fall through control
2221 successors = block->successors(&str, NULL, NULL);
2222 }
2223
2224 // Pass our state to successors.
2225 flow_successors(successors, state);
2226 }
2227
2228 // ------------------------------------------------------------------
2229 // ciTypeFlow::flow_types
2230 //
2231 // Perform the type flow analysis, creating and cloning Blocks as
2232 // necessary.
2233 void ciTypeFlow::flow_types() {
2234 ResourceMark rm;
2235 StateVector* temp_vector = new StateVector(this);
2236 JsrSet* temp_set = new JsrSet(NULL, 16);
2237
2238 // Create the method entry block.
2239 Block* block = block_at(start_bci(), temp_set);
2240 block->set_pre_order(_next_pre_order++);
2241 assert(block->is_start(), "start block must have order #0");
2242
2243 // Load the initial state into it.
2244 const StateVector* start_state = get_start_state();
2245 if (failing()) return;
2246 block->meet(start_state);
2247 add_to_work_list(block);
2248
2249 // Trickle away.
2250 while (!work_list_empty()) {
2251 Block* block = work_list_next();
2252 flow_block(block, temp_vector, temp_set);
2253
2254
2255 // NodeCountCutoff is the number of nodes at which the parser
2256 // will bail out. Probably if we already have lots of BBs,
2257 // the parser will generate at least twice that many nodes and bail out.
2258 // Therefore, this is a conservatively large limit at which to
2259 // bail out in the pre-parse typeflow pass.
2260 int block_limit = MaxNodeLimit / 2;
2261
2262 if (_next_pre_order >= block_limit) {
2263 // Too many basic blocks. Bail out.
2264 //
2265 // This can happen when try/finally constructs are nested to depth N,
2266 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2267 record_failure("too many basic blocks");
2268 return;
2269 }
2270
2271 // Watch for bailouts.
2272 if (failing()) return;
2273 }
2274 }
2275
2276 // ------------------------------------------------------------------
2277 // ciTypeFlow::map_blocks
2278 //
2279 // Create the block map, which indexes blocks in pre_order.
2280 void ciTypeFlow::map_blocks() {
2281 assert(_block_map == NULL, "single initialization");
2282 int pre_order_limit = _next_pre_order;
2283 _block_map = NEW_ARENA_ARRAY(arena(), Block*, pre_order_limit);
2284 assert(pre_order_limit == block_count(), "");
2285 int po;
2286 for (po = 0; po < pre_order_limit; po++) {
2287 debug_only(_block_map[po] = NULL);
2288 }
2289 ciMethodBlocks *mblks = _methodBlocks;
2290 ciBlock* current = NULL;
2291 int limit_bci = code_size();
2292 for (int bci = 0; bci < limit_bci; bci++) {
2293 ciBlock* ciblk = mblks->block_containing(bci);
2294 if (ciblk != NULL && ciblk != current) {
2295 current = ciblk;
2296 int curidx = ciblk->index();
2297 int block_count = (_idx_to_blocklist[curidx] == NULL) ? 0 : _idx_to_blocklist[curidx]->length();
2298 for (int i = 0; i < block_count; i++) {
2299 Block* block = _idx_to_blocklist[curidx]->at(i);
2300 if (!block->has_pre_order()) continue;
2301 int po = block->pre_order();
2302 assert(_block_map[po] == NULL, "unique ref to block");
2303 assert(0 <= po && po < pre_order_limit, "");
2304 _block_map[po] = block;
2305 }
2306 }
2307 }
2308 for (po = 0; po < pre_order_limit; po++) {
2309 assert(_block_map[po] != NULL, "must not drop any blocks");
2310 Block* block = _block_map[po];
2311 // Remove dead blocks from successor lists:
2312 for (int e = 0; e <= 1; e++) {
2313 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2314 for (int i = 0; i < l->length(); i++) {
2315 Block* s = l->at(i);
2316 if (!s->has_pre_order()) {
2317 if (CITraceTypeFlow) {
2318 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2319 s->print_value_on(tty);
2320 tty->cr();
2321 }
2322 l->remove(s);
2323 --i;
2324 }
2325 }
2326 }
2327 }
2328 }
2329
2330 // ------------------------------------------------------------------
2331 // ciTypeFlow::get_block_for
2332 //
2333 // Find a block with this ciBlock which has a compatible JsrSet.
2334 // If no such block exists, create it, unless the option is no_create.
2335 // If the option is create_private_copy, always create a fresh private copy.
2336 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2337 Arena* a = arena();
2338 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2339 if (blocks == NULL) {
2340 // Query only?
2341 if (option == no_create) return NULL;
2342
2343 // Allocate the growable array.
2344 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2345 _idx_to_blocklist[ciBlockIndex] = blocks;
2346 }
2347
2348 if (option != create_private_copy) {
2349 int len = blocks->length();
2350 for (int i = 0; i < len; i++) {
2351 Block* block = blocks->at(i);
2352 if (!block->is_private_copy() && block->is_compatible_with(jsrs)) {
2353 return block;
2354 }
2355 }
2356 }
2357
2358 // Query only?
2359 if (option == no_create) return NULL;
2360
2361 // We did not find a compatible block. Create one.
2362 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2363 if (option == create_private_copy) new_block->set_private_copy(true);
2364 blocks->append(new_block);
2365 return new_block;
2366 }
2367
2368 // ------------------------------------------------------------------
2369 // ciTypeFlow::private_copy_count
2370 //
2371 int ciTypeFlow::private_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2372 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2373
2374 if (blocks == NULL) {
2375 return 0;
2376 }
2377
2378 int count = 0;
2379 int len = blocks->length();
2380 for (int i = 0; i < len; i++) {
2381 Block* block = blocks->at(i);
2382 if (block->is_private_copy() && block->is_compatible_with(jsrs)) {
2383 count++;
2384 }
2385 }
2386
2387 return count;
2388 }
2389
2390 // ------------------------------------------------------------------
2391 // ciTypeFlow::do_flow
2392 //
2393 // Perform type inference flow analysis.
2394 void ciTypeFlow::do_flow() {
2395 if (CITraceTypeFlow) {
2396 tty->print_cr("\nPerforming flow analysis on method");
2397 method()->print();
2398 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2399 tty->cr();
2400 method()->print_codes();
2401 }
2402 if (CITraceTypeFlow) {
2403 tty->print_cr("Initial CI Blocks");
2404 print_on(tty);
2405 }
2406 flow_types();
2407 // Watch for bailouts.
2408 if (failing()) {
2409 return;
2410 }
2411 if (CIPrintTypeFlow || CITraceTypeFlow) {
2412 print_on(tty);
2413 }
2414 map_blocks();
2415 }
2416
2417 // ------------------------------------------------------------------
2418 // ciTypeFlow::record_failure()
2419 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
2420 // This is required because there is not a 1-1 relation between the ciEnv and
2421 // the TypeFlow passes within a compilation task. For example, if the compiler
2422 // is considering inlining a method, it will request a TypeFlow. If that fails,
2423 // the compilation as a whole may continue without the inlining. Some TypeFlow
2424 // requests are not optional; if they fail the requestor is responsible for
2425 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
2426 void ciTypeFlow::record_failure(const char* reason) {
2427 if (env()->log() != NULL) {
2428 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
2429 }
2430 if (_failure_reason == NULL) {
2431 // Record the first failure reason.
2432 _failure_reason = reason;
2433 }
2434 }
2435
2436 #ifndef PRODUCT
2437 // ------------------------------------------------------------------
2438 // ciTypeFlow::print_on
2439 void ciTypeFlow::print_on(outputStream* st) const {
2440 // Walk through CI blocks
2441 st->print_cr("********************************************************");
2442 st->print ("TypeFlow for ");
2443 method()->name()->print_symbol_on(st);
2444 int limit_bci = code_size();
2445 st->print_cr(" %d bytes", limit_bci);
2446 ciMethodBlocks *mblks = _methodBlocks;
2447 ciBlock* current = NULL;
2448 for (int bci = 0; bci < limit_bci; bci++) {
2449 ciBlock* blk = mblks->block_containing(bci);
2450 if (blk != NULL && blk != current) {
2451 current = blk;
2452 current->print_on(st);
2453
2454 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
2455 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
2456
2457 if (num_blocks == 0) {
2458 st->print_cr(" No Blocks");
2459 } else {
2460 for (int i = 0; i < num_blocks; i++) {
2461 Block* block = blocks->at(i);
2462 block->print_on(st);
2463 }
2464 }
2465 st->print_cr("--------------------------------------------------------");
2466 st->cr();
2467 }
2468 }
2469 st->print_cr("********************************************************");
2470 st->cr();
2471 }
2472 #endif