1 /*
2 * Copyright (c) 2000, 2015, 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.
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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.
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23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciMethod.hpp"
29 #include "ci/ciMethodData.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "ci/ciTypeArrayKlass.hpp"
33 #include "ci/ciTypeFlow.hpp"
34 #include "compiler/compileLog.hpp"
35 #include "interpreter/bytecode.hpp"
36 #include "interpreter/bytecodes.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "opto/compile.hpp"
40 #include "opto/node.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "utilities/growableArray.hpp"
43
44 // ciTypeFlow::JsrSet
45 //
46 // A JsrSet represents some set of JsrRecords. This class
47 // is used to record a set of all jsr routines which we permit
48 // execution to return (ret) from.
49 //
50 // During abstract interpretation, JsrSets are used to determine
51 // whether two paths which reach a given block are unique, and
52 // should be cloned apart, or are compatible, and should merge
53 // together.
54
55 // ------------------------------------------------------------------
56 // ciTypeFlow::JsrSet::JsrSet
57 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
58 if (arena != NULL) {
59 // Allocate growable array in Arena.
60 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
61 } else {
62 // Allocate growable array in current ResourceArea.
63 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
64 }
65 }
66
67 // ------------------------------------------------------------------
68 // ciTypeFlow::JsrSet::copy_into
69 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
70 int len = size();
71 jsrs->_set->clear();
72 for (int i = 0; i < len; i++) {
73 jsrs->_set->append(_set->at(i));
74 }
75 }
76
77 // ------------------------------------------------------------------
78 // ciTypeFlow::JsrSet::is_compatible_with
79 //
80 // !!!! MISGIVINGS ABOUT THIS... disregard
81 //
82 // Is this JsrSet compatible with some other JsrSet?
83 //
84 // In set-theoretic terms, a JsrSet can be viewed as a partial function
85 // from entry addresses to return addresses. Two JsrSets A and B are
86 // compatible iff
87 //
88 // For any x,
89 // A(x) defined and B(x) defined implies A(x) == B(x)
90 //
91 // Less formally, two JsrSets are compatible when they have identical
92 // return addresses for any entry addresses they share in common.
93 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
94 // Walk through both sets in parallel. If the same entry address
95 // appears in both sets, then the return address must match for
96 // the sets to be compatible.
97 int size1 = size();
98 int size2 = other->size();
99
100 // Special case. If nothing is on the jsr stack, then there can
101 // be no ret.
102 if (size2 == 0) {
103 return true;
104 } else if (size1 != size2) {
105 return false;
106 } else {
107 for (int i = 0; i < size1; i++) {
108 JsrRecord* record1 = record_at(i);
109 JsrRecord* record2 = other->record_at(i);
110 if (record1->entry_address() != record2->entry_address() ||
111 record1->return_address() != record2->return_address()) {
112 return false;
113 }
114 }
115 return true;
116 }
117
118 #if 0
119 int pos1 = 0;
120 int pos2 = 0;
121 int size1 = size();
122 int size2 = other->size();
123 while (pos1 < size1 && pos2 < size2) {
124 JsrRecord* record1 = record_at(pos1);
125 JsrRecord* record2 = other->record_at(pos2);
126 int entry1 = record1->entry_address();
127 int entry2 = record2->entry_address();
128 if (entry1 < entry2) {
129 pos1++;
130 } else if (entry1 > entry2) {
131 pos2++;
132 } else {
133 if (record1->return_address() == record2->return_address()) {
134 pos1++;
135 pos2++;
136 } else {
137 // These two JsrSets are incompatible.
138 return false;
139 }
140 }
141 }
142 // The two JsrSets agree.
143 return true;
144 #endif
145 }
146
147 // ------------------------------------------------------------------
148 // ciTypeFlow::JsrSet::insert_jsr_record
149 //
150 // Insert the given JsrRecord into the JsrSet, maintaining the order
151 // of the set and replacing any element with the same entry address.
152 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
153 int len = size();
154 int entry = record->entry_address();
155 int pos = 0;
156 for ( ; pos < len; pos++) {
157 JsrRecord* current = record_at(pos);
158 if (entry == current->entry_address()) {
159 // Stomp over this entry.
160 _set->at_put(pos, record);
161 assert(size() == len, "must be same size");
162 return;
163 } else if (entry < current->entry_address()) {
164 break;
165 }
166 }
167
168 // Insert the record into the list.
169 JsrRecord* swap = record;
170 JsrRecord* temp = NULL;
171 for ( ; pos < len; pos++) {
172 temp = _set->at(pos);
173 _set->at_put(pos, swap);
174 swap = temp;
175 }
176 _set->append(swap);
177 assert(size() == len+1, "must be larger");
178 }
179
180 // ------------------------------------------------------------------
181 // ciTypeFlow::JsrSet::remove_jsr_record
182 //
183 // Remove the JsrRecord with the given return address from the JsrSet.
184 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
185 int len = size();
186 for (int i = 0; i < len; i++) {
187 if (record_at(i)->return_address() == return_address) {
188 // We have found the proper entry. Remove it from the
189 // JsrSet and exit.
190 for (int j = i+1; j < len ; j++) {
191 _set->at_put(j-1, _set->at(j));
192 }
193 _set->trunc_to(len-1);
194 assert(size() == len-1, "must be smaller");
195 return;
196 }
197 }
198 assert(false, "verify: returning from invalid subroutine");
199 }
200
201 // ------------------------------------------------------------------
202 // ciTypeFlow::JsrSet::apply_control
203 //
204 // Apply the effect of a control-flow bytecode on the JsrSet. The
205 // only bytecodes that modify the JsrSet are jsr and ret.
206 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
207 ciBytecodeStream* str,
208 ciTypeFlow::StateVector* state) {
209 Bytecodes::Code code = str->cur_bc();
210 if (code == Bytecodes::_jsr) {
211 JsrRecord* record =
212 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
213 insert_jsr_record(record);
214 } else if (code == Bytecodes::_jsr_w) {
215 JsrRecord* record =
216 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
217 insert_jsr_record(record);
218 } else if (code == Bytecodes::_ret) {
219 Cell local = state->local(str->get_index());
220 ciType* return_address = state->type_at(local);
221 assert(return_address->is_return_address(), "verify: wrong type");
222 if (size() == 0) {
223 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
224 // This can happen when a loop is inside a finally clause (4614060).
225 analyzer->record_failure("OSR in finally clause");
226 return;
227 }
228 remove_jsr_record(return_address->as_return_address()->bci());
229 }
230 }
231
232 #ifndef PRODUCT
233 // ------------------------------------------------------------------
234 // ciTypeFlow::JsrSet::print_on
235 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
236 st->print("{ ");
237 int num_elements = size();
238 if (num_elements > 0) {
239 int i = 0;
240 for( ; i < num_elements - 1; i++) {
241 _set->at(i)->print_on(st);
242 st->print(", ");
243 }
244 _set->at(i)->print_on(st);
245 st->print(" ");
246 }
247 st->print("}");
248 }
249 #endif
250
251 // ciTypeFlow::StateVector
252 //
253 // A StateVector summarizes the type information at some point in
254 // the program.
255
256 // ------------------------------------------------------------------
257 // ciTypeFlow::StateVector::type_meet
258 //
259 // Meet two types.
260 //
261 // The semi-lattice of types use by this analysis are modeled on those
262 // of the verifier. The lattice is as follows:
263 //
264 // top_type() >= all non-extremal types >= bottom_type
265 // and
266 // Every primitive type is comparable only with itself. The meet of
267 // reference types is determined by their kind: instance class,
268 // interface, or array class. The meet of two types of the same
269 // kind is their least common ancestor. The meet of two types of
270 // different kinds is always java.lang.Object.
271 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
272 assert(t1 != t2, "checked in caller");
273 if (t1->equals(top_type())) {
274 return t2;
275 } else if (t2->equals(top_type())) {
276 return t1;
277 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
278 // Special case null_type. null_type meet any reference type T
279 // is T. null_type meet null_type is null_type.
280 if (t1->equals(null_type())) {
281 if (!t2->is_primitive_type() || t2->equals(null_type())) {
282 return t2;
283 }
284 } else if (t2->equals(null_type())) {
285 if (!t1->is_primitive_type()) {
286 return t1;
287 }
288 }
289
290 // At least one of the two types is a non-top primitive type.
291 // The other type is not equal to it. Fall to bottom.
292 return bottom_type();
293 } else {
294 // Both types are non-top non-primitive types. That is,
295 // both types are either instanceKlasses or arrayKlasses.
296 ciKlass* object_klass = analyzer->env()->Object_klass();
297 ciKlass* k1 = t1->as_klass();
298 ciKlass* k2 = t2->as_klass();
299 if (k1->equals(object_klass) || k2->equals(object_klass)) {
300 return object_klass;
301 } else if (!k1->is_loaded() || !k2->is_loaded()) {
302 // Unloaded classes fall to java.lang.Object at a merge.
303 return object_klass;
304 } else if (k1->is_interface() != k2->is_interface()) {
305 // When an interface meets a non-interface, we get Object;
306 // This is what the verifier does.
307 return object_klass;
308 } else if (k1->is_array_klass() || k2->is_array_klass()) {
309 // When an array meets a non-array, we get Object.
310 // When objArray meets typeArray, we also get Object.
311 // And when typeArray meets different typeArray, we again get Object.
312 // But when objArray meets objArray, we look carefully at element types.
313 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
314 // Meet the element types, then construct the corresponding array type.
315 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
316 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
317 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
318 // Do an easy shortcut if one type is a super of the other.
319 if (elem == elem1) {
320 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
321 return k1;
322 } else if (elem == elem2) {
323 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
324 return k2;
325 } else {
326 return ciObjArrayKlass::make(elem);
327 }
328 } else {
329 return object_klass;
330 }
331 } else {
332 // Must be two plain old instance klasses.
333 assert(k1->is_instance_klass(), "previous cases handle non-instances");
334 assert(k2->is_instance_klass(), "previous cases handle non-instances");
335 return k1->least_common_ancestor(k2);
336 }
337 }
338 }
339
340
341 // ------------------------------------------------------------------
342 // ciTypeFlow::StateVector::StateVector
343 //
344 // Build a new state vector
345 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
346 _outer = analyzer;
347 _stack_size = -1;
348 _monitor_count = -1;
349 // Allocate the _types array
350 int max_cells = analyzer->max_cells();
351 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
352 for (int i=0; i<max_cells; i++) {
353 _types[i] = top_type();
354 }
355 _trap_bci = -1;
356 _trap_index = 0;
357 _def_locals.clear();
358 }
359
360
361 // ------------------------------------------------------------------
362 // ciTypeFlow::get_start_state
363 //
364 // Set this vector to the method entry state.
365 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
366 StateVector* state = new StateVector(this);
367 if (is_osr_flow()) {
368 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
369 if (non_osr_flow->failing()) {
370 record_failure(non_osr_flow->failure_reason());
371 return NULL;
372 }
373 JsrSet* jsrs = new JsrSet(NULL, 16);
374 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
375 if (non_osr_block == NULL) {
376 record_failure("cannot reach OSR point");
377 return NULL;
378 }
379 // load up the non-OSR state at this point
380 non_osr_block->copy_state_into(state);
381 int non_osr_start = non_osr_block->start();
382 if (non_osr_start != start_bci()) {
383 // must flow forward from it
384 if (CITraceTypeFlow) {
385 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
386 }
387 Block* block = block_at(non_osr_start, jsrs);
388 assert(block->limit() == start_bci(), "must flow forward to start");
389 flow_block(block, state, jsrs);
390 }
391 return state;
392 // Note: The code below would be an incorrect for an OSR flow,
393 // even if it were possible for an OSR entry point to be at bci zero.
394 }
395 // "Push" the method signature into the first few locals.
396 state->set_stack_size(-max_locals());
397 if (!method()->is_static()) {
398 state->push(method()->holder());
399 assert(state->tos() == state->local(0), "");
400 }
401 for (ciSignatureStream str(method()->signature());
402 !str.at_return_type();
403 str.next()) {
404 state->push_translate(str.type());
405 }
406 // Set the rest of the locals to bottom.
407 Cell cell = state->next_cell(state->tos());
408 state->set_stack_size(0);
409 int limit = state->limit_cell();
410 for (; cell < limit; cell = state->next_cell(cell)) {
411 state->set_type_at(cell, state->bottom_type());
412 }
413 // Lock an object, if necessary.
414 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
415 return state;
416 }
417
418 // ------------------------------------------------------------------
419 // ciTypeFlow::StateVector::copy_into
420 //
421 // Copy our value into some other StateVector
422 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
423 const {
424 copy->set_stack_size(stack_size());
425 copy->set_monitor_count(monitor_count());
426 Cell limit = limit_cell();
427 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
428 copy->set_type_at(c, type_at(c));
429 }
430 }
431
432 // ------------------------------------------------------------------
433 // ciTypeFlow::StateVector::meet
434 //
435 // Meets this StateVector with another, destructively modifying this
436 // one. Returns true if any modification takes place.
437 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
438 if (monitor_count() == -1) {
439 set_monitor_count(incoming->monitor_count());
440 }
441 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
442
443 if (stack_size() == -1) {
444 set_stack_size(incoming->stack_size());
445 Cell limit = limit_cell();
446 #ifdef ASSERT
447 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
448 assert(type_at(c) == top_type(), "");
449 } }
450 #endif
451 // Make a simple copy of the incoming state.
452 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
453 set_type_at(c, incoming->type_at(c));
454 }
455 return true; // it is always different the first time
456 }
457 #ifdef ASSERT
458 if (stack_size() != incoming->stack_size()) {
459 _outer->method()->print_codes();
460 tty->print_cr("!!!! Stack size conflict");
461 tty->print_cr("Current state:");
462 print_on(tty);
463 tty->print_cr("Incoming state:");
464 ((StateVector*)incoming)->print_on(tty);
465 }
466 #endif
467 assert(stack_size() == incoming->stack_size(), "sanity");
468
469 bool different = false;
470 Cell limit = limit_cell();
471 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
472 ciType* t1 = type_at(c);
473 ciType* t2 = incoming->type_at(c);
474 if (!t1->equals(t2)) {
475 ciType* new_type = type_meet(t1, t2);
476 if (!t1->equals(new_type)) {
477 set_type_at(c, new_type);
478 different = true;
479 }
480 }
481 }
482 return different;
483 }
484
485 // ------------------------------------------------------------------
486 // ciTypeFlow::StateVector::meet_exception
487 //
488 // Meets this StateVector with another, destructively modifying this
489 // one. The incoming state is coming via an exception. Returns true
490 // if any modification takes place.
491 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
492 const ciTypeFlow::StateVector* incoming) {
493 if (monitor_count() == -1) {
494 set_monitor_count(incoming->monitor_count());
495 }
496 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
497
498 if (stack_size() == -1) {
499 set_stack_size(1);
500 }
501
502 assert(stack_size() == 1, "must have one-element stack");
503
504 bool different = false;
505
506 // Meet locals from incoming array.
507 Cell limit = local(_outer->max_locals()-1);
508 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
509 ciType* t1 = type_at(c);
510 ciType* t2 = incoming->type_at(c);
511 if (!t1->equals(t2)) {
512 ciType* new_type = type_meet(t1, t2);
513 if (!t1->equals(new_type)) {
514 set_type_at(c, new_type);
515 different = true;
516 }
517 }
518 }
519
520 // Handle stack separately. When an exception occurs, the
521 // only stack entry is the exception instance.
522 ciType* tos_type = type_at_tos();
523 if (!tos_type->equals(exc)) {
524 ciType* new_type = type_meet(tos_type, exc);
525 if (!tos_type->equals(new_type)) {
526 set_type_at_tos(new_type);
527 different = true;
528 }
529 }
530
531 return different;
532 }
533
534 // ------------------------------------------------------------------
535 // ciTypeFlow::StateVector::push_translate
536 void ciTypeFlow::StateVector::push_translate(ciType* type) {
537 BasicType basic_type = type->basic_type();
538 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
539 basic_type == T_BYTE || basic_type == T_SHORT) {
540 push_int();
541 } else {
542 push(type);
543 if (type->is_two_word()) {
544 push(half_type(type));
545 }
546 }
547 }
548
549 // ------------------------------------------------------------------
550 // ciTypeFlow::StateVector::do_aload
551 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
552 pop_int();
553 ciArrayKlass* array_klass = pop_objOrValueArray();
554 if (array_klass == NULL) {
555 // Did aload on a null reference; push a null and ignore the exception.
556 // This instruction will never continue normally. All we have to do
557 // is report a value that will meet correctly with any downstream
558 // reference types on paths that will truly be executed. This null type
559 // meets with any reference type to yield that same reference type.
560 // (The compiler will generate an unconditional exception here.)
561 push(null_type());
562 return;
563 }
564 if (!array_klass->is_loaded()) {
565 // Only fails for some -Xcomp runs
566 trap(str, array_klass,
567 Deoptimization::make_trap_request
568 (Deoptimization::Reason_unloaded,
569 Deoptimization::Action_reinterpret));
570 return;
571 }
572 ciKlass* element_klass = array_klass->element_klass();
573 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
574 Untested("unloaded array element class in ciTypeFlow");
575 trap(str, element_klass,
576 Deoptimization::make_trap_request
577 (Deoptimization::Reason_unloaded,
578 Deoptimization::Action_reinterpret));
579 } else {
580 push_object(element_klass);
581 }
582 }
583
584
585 // ------------------------------------------------------------------
586 // ciTypeFlow::StateVector::do_checkcast
587 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
588 bool will_link;
589 ciKlass* klass = str->get_klass(will_link);
590 if (!will_link) {
591 // VM's interpreter will not load 'klass' if object is NULL.
592 // Type flow after this block may still be needed in two situations:
593 // 1) C2 uses do_null_assert() and continues compilation for later blocks
594 // 2) C2 does an OSR compile in a later block (see bug 4778368).
595 pop_object();
596 do_null_assert(klass);
597 } else {
598 pop_object();
599 push_object(klass);
600 }
601 }
602
603 // ------------------------------------------------------------------
604 // ciTypeFlow::StateVector::do_getfield
605 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
606 // could add assert here for type of object.
607 pop_object();
608 do_getstatic(str);
609 }
610
611 // ------------------------------------------------------------------
612 // ciTypeFlow::StateVector::do_getstatic
613 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
614 bool will_link;
615 ciField* field = str->get_field(will_link);
616 if (!will_link) {
617 trap(str, field->holder(), str->get_field_holder_index());
618 } else {
619 ciType* field_type = field->type();
620 if (!field_type->is_loaded()) {
621 // Normally, we need the field's type to be loaded if we are to
622 // do anything interesting with its value.
623 // We used to do this: trap(str, str->get_field_signature_index());
624 //
625 // There is one good reason not to trap here. Execution can
626 // get past this "getfield" or "getstatic" if the value of
627 // the field is null. As long as the value is null, the class
628 // does not need to be loaded! The compiler must assume that
629 // the value of the unloaded class reference is null; if the code
630 // ever sees a non-null value, loading has occurred.
631 //
632 // This actually happens often enough to be annoying. If the
633 // compiler throws an uncommon trap at this bytecode, you can
634 // get an endless loop of recompilations, when all the code
635 // needs to do is load a series of null values. Also, a trap
636 // here can make an OSR entry point unreachable, triggering the
637 // assert on non_osr_block in ciTypeFlow::get_start_state.
638 // (See bug 4379915.)
639 do_null_assert(field_type->as_klass());
640 } else {
641 push_translate(field_type);
642 }
643 }
644 }
645
646 // ------------------------------------------------------------------
647 // ciTypeFlow::StateVector::do_invoke
648 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
649 bool has_receiver) {
650 bool will_link;
651 ciSignature* declared_signature = NULL;
652 ciMethod* callee = str->get_method(will_link, &declared_signature);
653 assert(declared_signature != NULL, "cannot be null");
654 if (!will_link) {
655 // We weren't able to find the method.
656 if (str->cur_bc() == Bytecodes::_invokedynamic) {
657 trap(str, NULL,
658 Deoptimization::make_trap_request
659 (Deoptimization::Reason_uninitialized,
660 Deoptimization::Action_reinterpret));
661 } else {
662 ciKlass* unloaded_holder = callee->holder();
663 trap(str, unloaded_holder, str->get_method_holder_index());
664 }
665 } else {
666 // We are using the declared signature here because it might be
667 // different from the callee signature (Cf. invokedynamic and
668 // invokehandle).
669 ciSignatureStream sigstr(declared_signature);
670 const int arg_size = declared_signature->size();
671 const int stack_base = stack_size() - arg_size;
672 int i = 0;
673 for( ; !sigstr.at_return_type(); sigstr.next()) {
674 ciType* type = sigstr.type();
675 ciType* stack_type = type_at(stack(stack_base + i++));
676 // Do I want to check this type?
677 // assert(stack_type->is_subtype_of(type), "bad type for field value");
678 if (type->is_two_word()) {
679 ciType* stack_type2 = type_at(stack(stack_base + i++));
680 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
681 }
682 }
683 assert(arg_size == i, "must match");
684 for (int j = 0; j < arg_size; j++) {
685 pop();
686 }
687 if (has_receiver) {
688 // Check this?
689 pop_object();
690 }
691 assert(!sigstr.is_done(), "must have return type");
692 ciType* return_type = sigstr.type();
693 if (!return_type->is_void()) {
694 if (!return_type->is_loaded()) {
695 // As in do_getstatic(), generally speaking, we need the return type to
696 // be loaded if we are to do anything interesting with its value.
697 // We used to do this: trap(str, str->get_method_signature_index());
698 //
699 // We do not trap here since execution can get past this invoke if
700 // the return value is null. As long as the value is null, the class
701 // does not need to be loaded! The compiler must assume that
702 // the value of the unloaded class reference is null; if the code
703 // ever sees a non-null value, loading has occurred.
704 //
705 // See do_getstatic() for similar explanation, as well as bug 4684993.
706 do_null_assert(return_type->as_klass());
707 } else {
708 push_translate(return_type);
709 }
710 }
711 }
712 }
713
714 // ------------------------------------------------------------------
715 // ciTypeFlow::StateVector::do_jsr
716 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
717 push(ciReturnAddress::make(str->next_bci()));
718 }
719
720 // ------------------------------------------------------------------
721 // ciTypeFlow::StateVector::do_ldc
722 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
723 ciConstant con = str->get_constant();
724 BasicType basic_type = con.basic_type();
725 if (basic_type == T_ILLEGAL) {
726 // OutOfMemoryError in the CI while loading constant
727 push_null();
728 outer()->record_failure("ldc did not link");
729 return;
730 }
731 if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
732 ciObject* obj = con.as_object();
733 if (obj->is_null_object()) {
734 push_null();
735 } else {
736 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
737 push_object(obj->klass());
738 }
739 } else {
740 push_translate(ciType::make(basic_type));
741 }
742 }
743
744 // ------------------------------------------------------------------
745 // ciTypeFlow::StateVector::do_multianewarray
746 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
747 int dimensions = str->get_dimensions();
748 bool will_link;
749 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
750 if (!will_link) {
751 trap(str, array_klass, str->get_klass_index());
752 } else {
753 for (int i = 0; i < dimensions; i++) {
754 pop_int();
755 }
756 push_object(array_klass);
757 }
758 }
759
760 // ------------------------------------------------------------------
761 // ciTypeFlow::StateVector::do_new
762 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
763 bool will_link;
764 ciKlass* klass = str->get_klass(will_link);
765 if (!will_link || str->is_unresolved_klass()) {
766 trap(str, klass, str->get_klass_index());
767 } else {
768 push_object(klass);
769 }
770 }
771
772 // ------------------------------------------------------------------
773 // ciTypeFlow::StateVector::do_vnew
774 void ciTypeFlow::StateVector::do_vnew(ciBytecodeStream* str) {
775 // This assumes that vnew is only valid in a static value type constructor
776 ciInstanceKlass* klass = str->method()->holder();
777 // TODO add additional verification (see InterpreterRuntime::_vnew)
778 assert(klass->is_valuetype(), "should be value type");
779 // TODO do check for unresolved?
780 // TODO value types should not be handled as objects
781 push_object(klass);
782 }
783
784 // ------------------------------------------------------------------
785 // ciTypeFlow::StateVector::do_newarray
786 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
787 pop_int();
788 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
789 push_object(klass);
790 }
791
792 // ------------------------------------------------------------------
793 // ciTypeFlow::StateVector::do_putfield
794 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
795 do_putstatic(str);
796 if (_trap_bci != -1) return; // unloaded field holder, etc.
797 // could add assert here for type of object.
798 pop_object();
799 }
800
801 // ------------------------------------------------------------------
802 // ciTypeFlow::StateVector::do_putstatic
803 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
804 bool will_link;
805 ciField* field = str->get_field(will_link);
806 if (!will_link) {
807 trap(str, field->holder(), str->get_field_holder_index());
808 } else {
809 ciType* field_type = field->type();
810 ciType* type = pop_value();
811 // Do I want to check this type?
812 // assert(type->is_subtype_of(field_type), "bad type for field value");
813 if (field_type->is_two_word()) {
814 ciType* type2 = pop_value();
815 assert(type2->is_two_word(), "must be 2nd half");
816 assert(type == half_type(type2), "must be 2nd half");
817 }
818 }
819 }
820
821 // ------------------------------------------------------------------
822 // ciTypeFlow::StateVector::do_ret
823 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
824 Cell index = local(str->get_index());
825
826 ciType* address = type_at(index);
827 assert(address->is_return_address(), "bad return address");
828 set_type_at(index, bottom_type());
829 }
830
831 void ciTypeFlow::StateVector::do_vunbox(ciBytecodeStream* str) {
832 bool will_link;
833 ciKlass* klass = str->get_klass(will_link);
834 // TODO: Handle case when class is not loaded.
835 guarantee(will_link, "Class to which the value-capable class will unbox to must be loaded for JIT compilation");
836 assert(klass->is_valuetype(), "must be value type");
837 pop_object();
838 push_object(klass->as_value_klass());
839 }
840
841 void ciTypeFlow::StateVector::do_vbox(ciBytecodeStream* str) {
842 bool will_link;
843 ciKlass* klass = str->get_klass(will_link);
844 // TODO: Handle case when class is not loaded.
845 guarantee(will_link, "Class to which value type will box to must be loaded for JIT compilation");
846 assert(klass->is_instance_klass(), "must be an instance class");
847 pop_object();
848 push_object(klass->as_instance_klass());
849 }
850
851 // ------------------------------------------------------------------
852 // ciTypeFlow::StateVector::trap
853 //
854 // Stop interpretation of this path with a trap.
855 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
856 _trap_bci = str->cur_bci();
857 _trap_index = index;
858
859 // Log information about this trap:
860 CompileLog* log = outer()->env()->log();
861 if (log != NULL) {
862 int mid = log->identify(outer()->method());
863 int kid = (klass == NULL)? -1: log->identify(klass);
864 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
865 char buf[100];
866 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
867 index));
868 if (kid >= 0)
869 log->print(" klass='%d'", kid);
870 log->end_elem();
871 }
872 }
873
874 // ------------------------------------------------------------------
875 // ciTypeFlow::StateVector::do_null_assert
876 // Corresponds to graphKit::do_null_assert.
877 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
878 if (unloaded_klass->is_loaded()) {
879 // We failed to link, but we can still compute with this class,
880 // since it is loaded somewhere. The compiler will uncommon_trap
881 // if the object is not null, but the typeflow pass can not assume
882 // that the object will be null, otherwise it may incorrectly tell
883 // the parser that an object is known to be null. 4761344, 4807707
884 push_object(unloaded_klass);
885 } else {
886 // The class is not loaded anywhere. It is safe to model the
887 // null in the typestates, because we can compile in a null check
888 // which will deoptimize us if someone manages to load the
889 // class later.
890 push_null();
891 }
892 }
893
894
895 // ------------------------------------------------------------------
896 // ciTypeFlow::StateVector::apply_one_bytecode
897 //
898 // Apply the effect of one bytecode to this StateVector
899 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
900 _trap_bci = -1;
901 _trap_index = 0;
902
903 if (CITraceTypeFlow) {
904 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
905 Bytecodes::name(str->cur_bc()));
906 }
907
908 switch(str->cur_bc()) {
909 case Bytecodes::_vaload:
910 case Bytecodes::_aaload: do_aload(str); break;
911
912 case Bytecodes::_vastore:
913 case Bytecodes::_aastore:
914 {
915 pop_object();
916 pop_int();
917 pop_objOrValueArray();
918 break;
919 }
920 case Bytecodes::_aconst_null:
921 {
922 push_null();
923 break;
924 }
925 case Bytecodes::_vload:
926 case Bytecodes::_aload: load_local_object(str->get_index()); break;
927 case Bytecodes::_aload_0: load_local_object(0); break;
928 case Bytecodes::_aload_1: load_local_object(1); break;
929 case Bytecodes::_aload_2: load_local_object(2); break;
930 case Bytecodes::_aload_3: load_local_object(3); break;
931
932 case Bytecodes::_anewarray:
933 {
934 pop_int();
935 bool will_link;
936 ciKlass* element_klass = str->get_klass(will_link);
937 if (!will_link) {
938 trap(str, element_klass, str->get_klass_index());
939 } else {
940 push_object(ciArrayKlass::make(element_klass));
941 }
942 break;
943 }
944 case Bytecodes::_areturn:
945 case Bytecodes::_vreturn:
946 case Bytecodes::_ifnonnull:
947 case Bytecodes::_ifnull:
948 {
949 pop_object();
950 break;
951 }
952 case Bytecodes::_monitorenter:
953 {
954 pop_object();
955 set_monitor_count(monitor_count() + 1);
956 break;
957 }
958 case Bytecodes::_monitorexit:
959 {
960 pop_object();
961 assert(monitor_count() > 0, "must be a monitor to exit from");
962 set_monitor_count(monitor_count() - 1);
963 break;
964 }
965 case Bytecodes::_arraylength:
966 {
967 pop_array();
968 push_int();
969 break;
970 }
971 case Bytecodes::_vstore:
972 case Bytecodes::_astore: store_local_object(str->get_index()); break;
973 case Bytecodes::_astore_0: store_local_object(0); break;
974 case Bytecodes::_astore_1: store_local_object(1); break;
975 case Bytecodes::_astore_2: store_local_object(2); break;
976 case Bytecodes::_astore_3: store_local_object(3); break;
977
978 case Bytecodes::_athrow:
979 {
980 NEEDS_CLEANUP;
981 pop_object();
982 break;
983 }
984 case Bytecodes::_baload:
985 case Bytecodes::_caload:
986 case Bytecodes::_iaload:
987 case Bytecodes::_saload:
988 {
989 pop_int();
990 ciTypeArrayKlass* array_klass = pop_typeArray();
991 // Put assert here for right type?
992 push_int();
993 break;
994 }
995 case Bytecodes::_bastore:
996 case Bytecodes::_castore:
997 case Bytecodes::_iastore:
998 case Bytecodes::_sastore:
999 {
1000 pop_int();
1001 pop_int();
1002 pop_typeArray();
1003 // assert here?
1004 break;
1005 }
1006 case Bytecodes::_bipush:
1007 case Bytecodes::_iconst_m1:
1008 case Bytecodes::_iconst_0:
1009 case Bytecodes::_iconst_1:
1010 case Bytecodes::_iconst_2:
1011 case Bytecodes::_iconst_3:
1012 case Bytecodes::_iconst_4:
1013 case Bytecodes::_iconst_5:
1014 case Bytecodes::_sipush:
1015 {
1016 push_int();
1017 break;
1018 }
1019 case Bytecodes::_checkcast: do_checkcast(str); break;
1020
1021 case Bytecodes::_d2f:
1022 {
1023 pop_double();
1024 push_float();
1025 break;
1026 }
1027 case Bytecodes::_d2i:
1028 {
1029 pop_double();
1030 push_int();
1031 break;
1032 }
1033 case Bytecodes::_d2l:
1034 {
1035 pop_double();
1036 push_long();
1037 break;
1038 }
1039 case Bytecodes::_dadd:
1040 case Bytecodes::_ddiv:
1041 case Bytecodes::_dmul:
1042 case Bytecodes::_drem:
1043 case Bytecodes::_dsub:
1044 {
1045 pop_double();
1046 pop_double();
1047 push_double();
1048 break;
1049 }
1050 case Bytecodes::_daload:
1051 {
1052 pop_int();
1053 ciTypeArrayKlass* array_klass = pop_typeArray();
1054 // Put assert here for right type?
1055 push_double();
1056 break;
1057 }
1058 case Bytecodes::_dastore:
1059 {
1060 pop_double();
1061 pop_int();
1062 pop_typeArray();
1063 // assert here?
1064 break;
1065 }
1066 case Bytecodes::_dcmpg:
1067 case Bytecodes::_dcmpl:
1068 {
1069 pop_double();
1070 pop_double();
1071 push_int();
1072 break;
1073 }
1074 case Bytecodes::_dconst_0:
1075 case Bytecodes::_dconst_1:
1076 {
1077 push_double();
1078 break;
1079 }
1080 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1081 case Bytecodes::_dload_0: load_local_double(0); break;
1082 case Bytecodes::_dload_1: load_local_double(1); break;
1083 case Bytecodes::_dload_2: load_local_double(2); break;
1084 case Bytecodes::_dload_3: load_local_double(3); break;
1085
1086 case Bytecodes::_dneg:
1087 {
1088 pop_double();
1089 push_double();
1090 break;
1091 }
1092 case Bytecodes::_dreturn:
1093 {
1094 pop_double();
1095 break;
1096 }
1097 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1098 case Bytecodes::_dstore_0: store_local_double(0); break;
1099 case Bytecodes::_dstore_1: store_local_double(1); break;
1100 case Bytecodes::_dstore_2: store_local_double(2); break;
1101 case Bytecodes::_dstore_3: store_local_double(3); break;
1102
1103 case Bytecodes::_dup:
1104 {
1105 push(type_at_tos());
1106 break;
1107 }
1108 case Bytecodes::_dup_x1:
1109 {
1110 ciType* value1 = pop_value();
1111 ciType* value2 = pop_value();
1112 push(value1);
1113 push(value2);
1114 push(value1);
1115 break;
1116 }
1117 case Bytecodes::_dup_x2:
1118 {
1119 ciType* value1 = pop_value();
1120 ciType* value2 = pop_value();
1121 ciType* value3 = pop_value();
1122 push(value1);
1123 push(value3);
1124 push(value2);
1125 push(value1);
1126 break;
1127 }
1128 case Bytecodes::_dup2:
1129 {
1130 ciType* value1 = pop_value();
1131 ciType* value2 = pop_value();
1132 push(value2);
1133 push(value1);
1134 push(value2);
1135 push(value1);
1136 break;
1137 }
1138 case Bytecodes::_dup2_x1:
1139 {
1140 ciType* value1 = pop_value();
1141 ciType* value2 = pop_value();
1142 ciType* value3 = pop_value();
1143 push(value2);
1144 push(value1);
1145 push(value3);
1146 push(value2);
1147 push(value1);
1148 break;
1149 }
1150 case Bytecodes::_dup2_x2:
1151 {
1152 ciType* value1 = pop_value();
1153 ciType* value2 = pop_value();
1154 ciType* value3 = pop_value();
1155 ciType* value4 = pop_value();
1156 push(value2);
1157 push(value1);
1158 push(value4);
1159 push(value3);
1160 push(value2);
1161 push(value1);
1162 break;
1163 }
1164 case Bytecodes::_f2d:
1165 {
1166 pop_float();
1167 push_double();
1168 break;
1169 }
1170 case Bytecodes::_f2i:
1171 {
1172 pop_float();
1173 push_int();
1174 break;
1175 }
1176 case Bytecodes::_f2l:
1177 {
1178 pop_float();
1179 push_long();
1180 break;
1181 }
1182 case Bytecodes::_fadd:
1183 case Bytecodes::_fdiv:
1184 case Bytecodes::_fmul:
1185 case Bytecodes::_frem:
1186 case Bytecodes::_fsub:
1187 {
1188 pop_float();
1189 pop_float();
1190 push_float();
1191 break;
1192 }
1193 case Bytecodes::_faload:
1194 {
1195 pop_int();
1196 ciTypeArrayKlass* array_klass = pop_typeArray();
1197 // Put assert here.
1198 push_float();
1199 break;
1200 }
1201 case Bytecodes::_fastore:
1202 {
1203 pop_float();
1204 pop_int();
1205 ciTypeArrayKlass* array_klass = pop_typeArray();
1206 // Put assert here.
1207 break;
1208 }
1209 case Bytecodes::_fcmpg:
1210 case Bytecodes::_fcmpl:
1211 {
1212 pop_float();
1213 pop_float();
1214 push_int();
1215 break;
1216 }
1217 case Bytecodes::_fconst_0:
1218 case Bytecodes::_fconst_1:
1219 case Bytecodes::_fconst_2:
1220 {
1221 push_float();
1222 break;
1223 }
1224 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1225 case Bytecodes::_fload_0: load_local_float(0); break;
1226 case Bytecodes::_fload_1: load_local_float(1); break;
1227 case Bytecodes::_fload_2: load_local_float(2); break;
1228 case Bytecodes::_fload_3: load_local_float(3); break;
1229
1230 case Bytecodes::_fneg:
1231 {
1232 pop_float();
1233 push_float();
1234 break;
1235 }
1236 case Bytecodes::_freturn:
1237 {
1238 pop_float();
1239 break;
1240 }
1241 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1242 case Bytecodes::_fstore_0: store_local_float(0); break;
1243 case Bytecodes::_fstore_1: store_local_float(1); break;
1244 case Bytecodes::_fstore_2: store_local_float(2); break;
1245 case Bytecodes::_fstore_3: store_local_float(3); break;
1246
1247 case Bytecodes::_vgetfield:
1248 case Bytecodes::_getfield: do_getfield(str); break;
1249 case Bytecodes::_getstatic: do_getstatic(str); break;
1250
1251 case Bytecodes::_goto:
1252 case Bytecodes::_goto_w:
1253 case Bytecodes::_nop:
1254 case Bytecodes::_return:
1255 {
1256 // do nothing.
1257 break;
1258 }
1259 case Bytecodes::_i2b:
1260 case Bytecodes::_i2c:
1261 case Bytecodes::_i2s:
1262 case Bytecodes::_ineg:
1263 {
1264 pop_int();
1265 push_int();
1266 break;
1267 }
1268 case Bytecodes::_i2d:
1269 {
1270 pop_int();
1271 push_double();
1272 break;
1273 }
1274 case Bytecodes::_i2f:
1275 {
1276 pop_int();
1277 push_float();
1278 break;
1279 }
1280 case Bytecodes::_i2l:
1281 {
1282 pop_int();
1283 push_long();
1284 break;
1285 }
1286 case Bytecodes::_iadd:
1287 case Bytecodes::_iand:
1288 case Bytecodes::_idiv:
1289 case Bytecodes::_imul:
1290 case Bytecodes::_ior:
1291 case Bytecodes::_irem:
1292 case Bytecodes::_ishl:
1293 case Bytecodes::_ishr:
1294 case Bytecodes::_isub:
1295 case Bytecodes::_iushr:
1296 case Bytecodes::_ixor:
1297 {
1298 pop_int();
1299 pop_int();
1300 push_int();
1301 break;
1302 }
1303 case Bytecodes::_if_acmpeq:
1304 case Bytecodes::_if_acmpne:
1305 {
1306 pop_object();
1307 pop_object();
1308 break;
1309 }
1310 case Bytecodes::_if_icmpeq:
1311 case Bytecodes::_if_icmpge:
1312 case Bytecodes::_if_icmpgt:
1313 case Bytecodes::_if_icmple:
1314 case Bytecodes::_if_icmplt:
1315 case Bytecodes::_if_icmpne:
1316 {
1317 pop_int();
1318 pop_int();
1319 break;
1320 }
1321 case Bytecodes::_ifeq:
1322 case Bytecodes::_ifle:
1323 case Bytecodes::_iflt:
1324 case Bytecodes::_ifge:
1325 case Bytecodes::_ifgt:
1326 case Bytecodes::_ifne:
1327 case Bytecodes::_ireturn:
1328 case Bytecodes::_lookupswitch:
1329 case Bytecodes::_tableswitch:
1330 {
1331 pop_int();
1332 break;
1333 }
1334 case Bytecodes::_iinc:
1335 {
1336 int lnum = str->get_index();
1337 check_int(local(lnum));
1338 store_to_local(lnum);
1339 break;
1340 }
1341 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1342 case Bytecodes::_iload_0: load_local_int(0); break;
1343 case Bytecodes::_iload_1: load_local_int(1); break;
1344 case Bytecodes::_iload_2: load_local_int(2); break;
1345 case Bytecodes::_iload_3: load_local_int(3); break;
1346
1347 case Bytecodes::_instanceof:
1348 {
1349 // Check for uncommon trap:
1350 do_checkcast(str);
1351 pop_object();
1352 push_int();
1353 break;
1354 }
1355 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1356 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1357 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1358 case Bytecodes::_invokedirect:
1359 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1360 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1361
1362 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1363 case Bytecodes::_istore_0: store_local_int(0); break;
1364 case Bytecodes::_istore_1: store_local_int(1); break;
1365 case Bytecodes::_istore_2: store_local_int(2); break;
1366 case Bytecodes::_istore_3: store_local_int(3); break;
1367
1368 case Bytecodes::_jsr:
1369 case Bytecodes::_jsr_w: do_jsr(str); break;
1370
1371 case Bytecodes::_l2d:
1372 {
1373 pop_long();
1374 push_double();
1375 break;
1376 }
1377 case Bytecodes::_l2f:
1378 {
1379 pop_long();
1380 push_float();
1381 break;
1382 }
1383 case Bytecodes::_l2i:
1384 {
1385 pop_long();
1386 push_int();
1387 break;
1388 }
1389 case Bytecodes::_ladd:
1390 case Bytecodes::_land:
1391 case Bytecodes::_ldiv:
1392 case Bytecodes::_lmul:
1393 case Bytecodes::_lor:
1394 case Bytecodes::_lrem:
1395 case Bytecodes::_lsub:
1396 case Bytecodes::_lxor:
1397 {
1398 pop_long();
1399 pop_long();
1400 push_long();
1401 break;
1402 }
1403 case Bytecodes::_laload:
1404 {
1405 pop_int();
1406 ciTypeArrayKlass* array_klass = pop_typeArray();
1407 // Put assert here for right type?
1408 push_long();
1409 break;
1410 }
1411 case Bytecodes::_lastore:
1412 {
1413 pop_long();
1414 pop_int();
1415 pop_typeArray();
1416 // assert here?
1417 break;
1418 }
1419 case Bytecodes::_lcmp:
1420 {
1421 pop_long();
1422 pop_long();
1423 push_int();
1424 break;
1425 }
1426 case Bytecodes::_lconst_0:
1427 case Bytecodes::_lconst_1:
1428 {
1429 push_long();
1430 break;
1431 }
1432 case Bytecodes::_ldc:
1433 case Bytecodes::_ldc_w:
1434 case Bytecodes::_ldc2_w:
1435 {
1436 do_ldc(str);
1437 break;
1438 }
1439
1440 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1441 case Bytecodes::_lload_0: load_local_long(0); break;
1442 case Bytecodes::_lload_1: load_local_long(1); break;
1443 case Bytecodes::_lload_2: load_local_long(2); break;
1444 case Bytecodes::_lload_3: load_local_long(3); break;
1445
1446 case Bytecodes::_lneg:
1447 {
1448 pop_long();
1449 push_long();
1450 break;
1451 }
1452 case Bytecodes::_lreturn:
1453 {
1454 pop_long();
1455 break;
1456 }
1457 case Bytecodes::_lshl:
1458 case Bytecodes::_lshr:
1459 case Bytecodes::_lushr:
1460 {
1461 pop_int();
1462 pop_long();
1463 push_long();
1464 break;
1465 }
1466 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1467 case Bytecodes::_lstore_0: store_local_long(0); break;
1468 case Bytecodes::_lstore_1: store_local_long(1); break;
1469 case Bytecodes::_lstore_2: store_local_long(2); break;
1470 case Bytecodes::_lstore_3: store_local_long(3); break;
1471
1472 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1473 case Bytecodes::_new: do_new(str); break;
1474 case Bytecodes::_vnew: do_vnew(str); break;
1475
1476 case Bytecodes::_newarray: do_newarray(str); break;
1477
1478 case Bytecodes::_pop:
1479 {
1480 pop();
1481 break;
1482 }
1483 case Bytecodes::_pop2:
1484 {
1485 pop();
1486 pop();
1487 break;
1488 }
1489
1490 case Bytecodes::_putfield: do_putfield(str); break;
1491 case Bytecodes::_putstatic: do_putstatic(str); break;
1492
1493 case Bytecodes::_ret: do_ret(str); break;
1494
1495 case Bytecodes::_swap:
1496 {
1497 ciType* value1 = pop_value();
1498 ciType* value2 = pop_value();
1499 push(value1);
1500 push(value2);
1501 break;
1502 }
1503 case Bytecodes::_vunbox:
1504 {
1505 do_vunbox(str);
1506 break;
1507 }
1508 case Bytecodes::_vbox:
1509 {
1510 do_vbox(str);
1511 break;
1512 }
1513 case Bytecodes::_wide:
1514 default:
1515 {
1516 // The iterator should skip this.
1517 ShouldNotReachHere();
1518 break;
1519 }
1520 }
1521
1522 if (CITraceTypeFlow) {
1523 print_on(tty);
1524 }
1525
1526 return (_trap_bci != -1);
1527 }
1528
1529 #ifndef PRODUCT
1530 // ------------------------------------------------------------------
1531 // ciTypeFlow::StateVector::print_cell_on
1532 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1533 ciType* type = type_at(c);
1534 if (type == top_type()) {
1535 st->print("top");
1536 } else if (type == bottom_type()) {
1537 st->print("bottom");
1538 } else if (type == null_type()) {
1539 st->print("null");
1540 } else if (type == long2_type()) {
1541 st->print("long2");
1542 } else if (type == double2_type()) {
1543 st->print("double2");
1544 } else if (is_int(type)) {
1545 st->print("int");
1546 } else if (is_long(type)) {
1547 st->print("long");
1548 } else if (is_float(type)) {
1549 st->print("float");
1550 } else if (is_double(type)) {
1551 st->print("double");
1552 } else if (type->is_return_address()) {
1553 st->print("address(%d)", type->as_return_address()->bci());
1554 } else {
1555 if (type->is_klass()) {
1556 type->as_klass()->name()->print_symbol_on(st);
1557 } else {
1558 st->print("UNEXPECTED TYPE");
1559 type->print();
1560 }
1561 }
1562 }
1563
1564 // ------------------------------------------------------------------
1565 // ciTypeFlow::StateVector::print_on
1566 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1567 int num_locals = _outer->max_locals();
1568 int num_stack = stack_size();
1569 int num_monitors = monitor_count();
1570 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1571 if (num_stack >= 0) {
1572 int i;
1573 for (i = 0; i < num_locals; i++) {
1574 st->print(" local %2d : ", i);
1575 print_cell_on(st, local(i));
1576 st->cr();
1577 }
1578 for (i = 0; i < num_stack; i++) {
1579 st->print(" stack %2d : ", i);
1580 print_cell_on(st, stack(i));
1581 st->cr();
1582 }
1583 }
1584 }
1585 #endif
1586
1587
1588 // ------------------------------------------------------------------
1589 // ciTypeFlow::SuccIter::next
1590 //
1591 void ciTypeFlow::SuccIter::next() {
1592 int succ_ct = _pred->successors()->length();
1593 int next = _index + 1;
1594 if (next < succ_ct) {
1595 _index = next;
1596 _succ = _pred->successors()->at(next);
1597 return;
1598 }
1599 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1600 // Do not compile any code for unloaded exception types.
1601 // Following compiler passes are responsible for doing this also.
1602 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1603 if (exception_klass->is_loaded()) {
1604 _index = next;
1605 _succ = _pred->exceptions()->at(i);
1606 return;
1607 }
1608 next++;
1609 }
1610 _index = -1;
1611 _succ = NULL;
1612 }
1613
1614 // ------------------------------------------------------------------
1615 // ciTypeFlow::SuccIter::set_succ
1616 //
1617 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1618 int succ_ct = _pred->successors()->length();
1619 if (_index < succ_ct) {
1620 _pred->successors()->at_put(_index, succ);
1621 } else {
1622 int idx = _index - succ_ct;
1623 _pred->exceptions()->at_put(idx, succ);
1624 }
1625 }
1626
1627 // ciTypeFlow::Block
1628 //
1629 // A basic block.
1630
1631 // ------------------------------------------------------------------
1632 // ciTypeFlow::Block::Block
1633 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1634 ciBlock *ciblk,
1635 ciTypeFlow::JsrSet* jsrs) {
1636 _ciblock = ciblk;
1637 _exceptions = NULL;
1638 _exc_klasses = NULL;
1639 _successors = NULL;
1640 _predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
1641 _state = new (outer->arena()) StateVector(outer);
1642 JsrSet* new_jsrs =
1643 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1644 jsrs->copy_into(new_jsrs);
1645 _jsrs = new_jsrs;
1646 _next = NULL;
1647 _on_work_list = false;
1648 _backedge_copy = false;
1649 _has_monitorenter = false;
1650 _trap_bci = -1;
1651 _trap_index = 0;
1652 df_init();
1653
1654 if (CITraceTypeFlow) {
1655 tty->print_cr(">> Created new block");
1656 print_on(tty);
1657 }
1658
1659 assert(this->outer() == outer, "outer link set up");
1660 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1661 }
1662
1663 // ------------------------------------------------------------------
1664 // ciTypeFlow::Block::df_init
1665 void ciTypeFlow::Block::df_init() {
1666 _pre_order = -1; assert(!has_pre_order(), "");
1667 _post_order = -1; assert(!has_post_order(), "");
1668 _loop = NULL;
1669 _irreducible_entry = false;
1670 _rpo_next = NULL;
1671 }
1672
1673 // ------------------------------------------------------------------
1674 // ciTypeFlow::Block::successors
1675 //
1676 // Get the successors for this Block.
1677 GrowableArray<ciTypeFlow::Block*>*
1678 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1679 ciTypeFlow::StateVector* state,
1680 ciTypeFlow::JsrSet* jsrs) {
1681 if (_successors == NULL) {
1682 if (CITraceTypeFlow) {
1683 tty->print(">> Computing successors for block ");
1684 print_value_on(tty);
1685 tty->cr();
1686 }
1687
1688 ciTypeFlow* analyzer = outer();
1689 Arena* arena = analyzer->arena();
1690 Block* block = NULL;
1691 bool has_successor = !has_trap() &&
1692 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1693 if (!has_successor) {
1694 _successors =
1695 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1696 // No successors
1697 } else if (control() == ciBlock::fall_through_bci) {
1698 assert(str->cur_bci() == limit(), "bad block end");
1699 // This block simply falls through to the next.
1700 _successors =
1701 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1702
1703 Block* block = analyzer->block_at(limit(), _jsrs);
1704 assert(_successors->length() == FALL_THROUGH, "");
1705 _successors->append(block);
1706 } else {
1707 int current_bci = str->cur_bci();
1708 int next_bci = str->next_bci();
1709 int branch_bci = -1;
1710 Block* target = NULL;
1711 assert(str->next_bci() == limit(), "bad block end");
1712 // This block is not a simple fall-though. Interpret
1713 // the current bytecode to find our successors.
1714 switch (str->cur_bc()) {
1715 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1716 case Bytecodes::_iflt: case Bytecodes::_ifge:
1717 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1718 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1719 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1720 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1721 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1722 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1723 // Our successors are the branch target and the next bci.
1724 branch_bci = str->get_dest();
1725 _successors =
1726 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1727 assert(_successors->length() == IF_NOT_TAKEN, "");
1728 _successors->append(analyzer->block_at(next_bci, jsrs));
1729 assert(_successors->length() == IF_TAKEN, "");
1730 _successors->append(analyzer->block_at(branch_bci, jsrs));
1731 break;
1732
1733 case Bytecodes::_goto:
1734 branch_bci = str->get_dest();
1735 _successors =
1736 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1737 assert(_successors->length() == GOTO_TARGET, "");
1738 _successors->append(analyzer->block_at(branch_bci, jsrs));
1739 break;
1740
1741 case Bytecodes::_jsr:
1742 branch_bci = str->get_dest();
1743 _successors =
1744 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1745 assert(_successors->length() == GOTO_TARGET, "");
1746 _successors->append(analyzer->block_at(branch_bci, jsrs));
1747 break;
1748
1749 case Bytecodes::_goto_w:
1750 case Bytecodes::_jsr_w:
1751 _successors =
1752 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1753 assert(_successors->length() == GOTO_TARGET, "");
1754 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1755 break;
1756
1757 case Bytecodes::_tableswitch: {
1758 Bytecode_tableswitch tableswitch(str);
1759
1760 int len = tableswitch.length();
1761 _successors =
1762 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1763 int bci = current_bci + tableswitch.default_offset();
1764 Block* block = analyzer->block_at(bci, jsrs);
1765 assert(_successors->length() == SWITCH_DEFAULT, "");
1766 _successors->append(block);
1767 while (--len >= 0) {
1768 int bci = current_bci + tableswitch.dest_offset_at(len);
1769 block = analyzer->block_at(bci, jsrs);
1770 assert(_successors->length() >= SWITCH_CASES, "");
1771 _successors->append_if_missing(block);
1772 }
1773 break;
1774 }
1775
1776 case Bytecodes::_lookupswitch: {
1777 Bytecode_lookupswitch lookupswitch(str);
1778
1779 int npairs = lookupswitch.number_of_pairs();
1780 _successors =
1781 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1782 int bci = current_bci + lookupswitch.default_offset();
1783 Block* block = analyzer->block_at(bci, jsrs);
1784 assert(_successors->length() == SWITCH_DEFAULT, "");
1785 _successors->append(block);
1786 while(--npairs >= 0) {
1787 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1788 int bci = current_bci + pair.offset();
1789 Block* block = analyzer->block_at(bci, jsrs);
1790 assert(_successors->length() >= SWITCH_CASES, "");
1791 _successors->append_if_missing(block);
1792 }
1793 break;
1794 }
1795
1796 case Bytecodes::_athrow:
1797 case Bytecodes::_ireturn:
1798 case Bytecodes::_lreturn:
1799 case Bytecodes::_freturn:
1800 case Bytecodes::_dreturn:
1801 case Bytecodes::_areturn:
1802 case Bytecodes::_vreturn:
1803 case Bytecodes::_return:
1804 _successors =
1805 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1806 // No successors
1807 break;
1808
1809 case Bytecodes::_ret: {
1810 _successors =
1811 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1812
1813 Cell local = state->local(str->get_index());
1814 ciType* return_address = state->type_at(local);
1815 assert(return_address->is_return_address(), "verify: wrong type");
1816 int bci = return_address->as_return_address()->bci();
1817 assert(_successors->length() == GOTO_TARGET, "");
1818 _successors->append(analyzer->block_at(bci, jsrs));
1819 break;
1820 }
1821
1822 case Bytecodes::_wide:
1823 default:
1824 ShouldNotReachHere();
1825 break;
1826 }
1827 }
1828
1829 // Set predecessor information
1830 for (int i = 0; i < _successors->length(); i++) {
1831 Block* block = _successors->at(i);
1832 block->predecessors()->append(this);
1833 }
1834 }
1835 return _successors;
1836 }
1837
1838 // ------------------------------------------------------------------
1839 // ciTypeFlow::Block:compute_exceptions
1840 //
1841 // Compute the exceptional successors and types for this Block.
1842 void ciTypeFlow::Block::compute_exceptions() {
1843 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1844
1845 if (CITraceTypeFlow) {
1846 tty->print(">> Computing exceptions for block ");
1847 print_value_on(tty);
1848 tty->cr();
1849 }
1850
1851 ciTypeFlow* analyzer = outer();
1852 Arena* arena = analyzer->arena();
1853
1854 // Any bci in the block will do.
1855 ciExceptionHandlerStream str(analyzer->method(), start());
1856
1857 // Allocate our growable arrays.
1858 int exc_count = str.count();
1859 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1860 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1861 0, NULL);
1862
1863 for ( ; !str.is_done(); str.next()) {
1864 ciExceptionHandler* handler = str.handler();
1865 int bci = handler->handler_bci();
1866 ciInstanceKlass* klass = NULL;
1867 if (bci == -1) {
1868 // There is no catch all. It is possible to exit the method.
1869 break;
1870 }
1871 if (handler->is_catch_all()) {
1872 klass = analyzer->env()->Throwable_klass();
1873 } else {
1874 klass = handler->catch_klass();
1875 }
1876 Block* block = analyzer->block_at(bci, _jsrs);
1877 _exceptions->append(block);
1878 block->predecessors()->append(this);
1879 _exc_klasses->append(klass);
1880 }
1881 }
1882
1883 // ------------------------------------------------------------------
1884 // ciTypeFlow::Block::set_backedge_copy
1885 // Use this only to make a pre-existing public block into a backedge copy.
1886 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1887 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1888 _backedge_copy = z;
1889 }
1890
1891 // ------------------------------------------------------------------
1892 // ciTypeFlow::Block::is_clonable_exit
1893 //
1894 // At most 2 normal successors, one of which continues looping,
1895 // and all exceptional successors must exit.
1896 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1897 int normal_cnt = 0;
1898 int in_loop_cnt = 0;
1899 for (SuccIter iter(this); !iter.done(); iter.next()) {
1900 Block* succ = iter.succ();
1901 if (iter.is_normal_ctrl()) {
1902 if (++normal_cnt > 2) return false;
1903 if (lp->contains(succ->loop())) {
1904 if (++in_loop_cnt > 1) return false;
1905 }
1906 } else {
1907 if (lp->contains(succ->loop())) return false;
1908 }
1909 }
1910 return in_loop_cnt == 1;
1911 }
1912
1913 // ------------------------------------------------------------------
1914 // ciTypeFlow::Block::looping_succ
1915 //
1916 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1917 assert(successors()->length() <= 2, "at most 2 normal successors");
1918 for (SuccIter iter(this); !iter.done(); iter.next()) {
1919 Block* succ = iter.succ();
1920 if (lp->contains(succ->loop())) {
1921 return succ;
1922 }
1923 }
1924 return NULL;
1925 }
1926
1927 #ifndef PRODUCT
1928 // ------------------------------------------------------------------
1929 // ciTypeFlow::Block::print_value_on
1930 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1931 if (has_pre_order()) st->print("#%-2d ", pre_order());
1932 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1933 st->print("[%d - %d)", start(), limit());
1934 if (is_loop_head()) st->print(" lphd");
1935 if (is_irreducible_entry()) st->print(" irred");
1936 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1937 if (is_backedge_copy()) st->print("/backedge_copy");
1938 }
1939
1940 // ------------------------------------------------------------------
1941 // ciTypeFlow::Block::print_on
1942 void ciTypeFlow::Block::print_on(outputStream* st) const {
1943 if ((Verbose || WizardMode) && (limit() >= 0)) {
1944 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1945 outer()->method()->print_codes_on(start(), limit(), st);
1946 }
1947 st->print_cr(" ==================================================== ");
1948 st->print (" ");
1949 print_value_on(st);
1950 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1951 if (loop() && loop()->parent() != NULL) {
1952 st->print(" loops:");
1953 Loop* lp = loop();
1954 do {
1955 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1956 if (lp->is_irreducible()) st->print("(ir)");
1957 lp = lp->parent();
1958 } while (lp->parent() != NULL);
1959 }
1960 st->cr();
1961 _state->print_on(st);
1962 if (_successors == NULL) {
1963 st->print_cr(" No successor information");
1964 } else {
1965 int num_successors = _successors->length();
1966 st->print_cr(" Successors : %d", num_successors);
1967 for (int i = 0; i < num_successors; i++) {
1968 Block* successor = _successors->at(i);
1969 st->print(" ");
1970 successor->print_value_on(st);
1971 st->cr();
1972 }
1973 }
1974 if (_predecessors == NULL) {
1975 st->print_cr(" No predecessor information");
1976 } else {
1977 int num_predecessors = _predecessors->length();
1978 st->print_cr(" Predecessors : %d", num_predecessors);
1979 for (int i = 0; i < num_predecessors; i++) {
1980 Block* predecessor = _predecessors->at(i);
1981 st->print(" ");
1982 predecessor->print_value_on(st);
1983 st->cr();
1984 }
1985 }
1986 if (_exceptions == NULL) {
1987 st->print_cr(" No exception information");
1988 } else {
1989 int num_exceptions = _exceptions->length();
1990 st->print_cr(" Exceptions : %d", num_exceptions);
1991 for (int i = 0; i < num_exceptions; i++) {
1992 Block* exc_succ = _exceptions->at(i);
1993 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1994 st->print(" ");
1995 exc_succ->print_value_on(st);
1996 st->print(" -- ");
1997 exc_klass->name()->print_symbol_on(st);
1998 st->cr();
1999 }
2000 }
2001 if (has_trap()) {
2002 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2003 }
2004 st->print_cr(" ==================================================== ");
2005 }
2006 #endif
2007
2008 #ifndef PRODUCT
2009 // ------------------------------------------------------------------
2010 // ciTypeFlow::LocalSet::print_on
2011 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2012 st->print("{");
2013 for (int i = 0; i < max; i++) {
2014 if (test(i)) st->print(" %d", i);
2015 }
2016 if (limit > max) {
2017 st->print(" %d..%d ", max, limit);
2018 }
2019 st->print(" }");
2020 }
2021 #endif
2022
2023 // ciTypeFlow
2024 //
2025 // This is a pass over the bytecodes which computes the following:
2026 // basic block structure
2027 // interpreter type-states (a la the verifier)
2028
2029 // ------------------------------------------------------------------
2030 // ciTypeFlow::ciTypeFlow
2031 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2032 _env = env;
2033 _method = method;
2034 _methodBlocks = method->get_method_blocks();
2035 _max_locals = method->max_locals();
2036 _max_stack = method->max_stack();
2037 _code_size = method->code_size();
2038 _has_irreducible_entry = false;
2039 _osr_bci = osr_bci;
2040 _failure_reason = NULL;
2041 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2042 _work_list = NULL;
2043
2044 _ciblock_count = _methodBlocks->num_blocks();
2045 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
2046 for (int i = 0; i < _ciblock_count; i++) {
2047 _idx_to_blocklist[i] = NULL;
2048 }
2049 _block_map = NULL; // until all blocks are seen
2050 _jsr_count = 0;
2051 _jsr_records = NULL;
2052 }
2053
2054 // ------------------------------------------------------------------
2055 // ciTypeFlow::work_list_next
2056 //
2057 // Get the next basic block from our work list.
2058 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2059 assert(!work_list_empty(), "work list must not be empty");
2060 Block* next_block = _work_list;
2061 _work_list = next_block->next();
2062 next_block->set_next(NULL);
2063 next_block->set_on_work_list(false);
2064 return next_block;
2065 }
2066
2067 // ------------------------------------------------------------------
2068 // ciTypeFlow::add_to_work_list
2069 //
2070 // Add a basic block to our work list.
2071 // List is sorted by decreasing postorder sort (same as increasing RPO)
2072 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2073 assert(!block->is_on_work_list(), "must not already be on work list");
2074
2075 if (CITraceTypeFlow) {
2076 tty->print(">> Adding block ");
2077 block->print_value_on(tty);
2078 tty->print_cr(" to the work list : ");
2079 }
2080
2081 block->set_on_work_list(true);
2082
2083 // decreasing post order sort
2084
2085 Block* prev = NULL;
2086 Block* current = _work_list;
2087 int po = block->post_order();
2088 while (current != NULL) {
2089 if (!current->has_post_order() || po > current->post_order())
2090 break;
2091 prev = current;
2092 current = current->next();
2093 }
2094 if (prev == NULL) {
2095 block->set_next(_work_list);
2096 _work_list = block;
2097 } else {
2098 block->set_next(current);
2099 prev->set_next(block);
2100 }
2101
2102 if (CITraceTypeFlow) {
2103 tty->cr();
2104 }
2105 }
2106
2107 // ------------------------------------------------------------------
2108 // ciTypeFlow::block_at
2109 //
2110 // Return the block beginning at bci which has a JsrSet compatible
2111 // with jsrs.
2112 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2113 // First find the right ciBlock.
2114 if (CITraceTypeFlow) {
2115 tty->print(">> Requesting block for %d/", bci);
2116 jsrs->print_on(tty);
2117 tty->cr();
2118 }
2119
2120 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2121 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2122 Block* block = get_block_for(ciblk->index(), jsrs, option);
2123
2124 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2125
2126 if (CITraceTypeFlow) {
2127 if (block != NULL) {
2128 tty->print(">> Found block ");
2129 block->print_value_on(tty);
2130 tty->cr();
2131 } else {
2132 tty->print_cr(">> No such block.");
2133 }
2134 }
2135
2136 return block;
2137 }
2138
2139 // ------------------------------------------------------------------
2140 // ciTypeFlow::make_jsr_record
2141 //
2142 // Make a JsrRecord for a given (entry, return) pair, if such a record
2143 // does not already exist.
2144 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2145 int return_address) {
2146 if (_jsr_records == NULL) {
2147 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2148 _jsr_count,
2149 0,
2150 NULL);
2151 }
2152 JsrRecord* record = NULL;
2153 int len = _jsr_records->length();
2154 for (int i = 0; i < len; i++) {
2155 JsrRecord* record = _jsr_records->at(i);
2156 if (record->entry_address() == entry_address &&
2157 record->return_address() == return_address) {
2158 return record;
2159 }
2160 }
2161
2162 record = new (arena()) JsrRecord(entry_address, return_address);
2163 _jsr_records->append(record);
2164 return record;
2165 }
2166
2167 // ------------------------------------------------------------------
2168 // ciTypeFlow::flow_exceptions
2169 //
2170 // Merge the current state into all exceptional successors at the
2171 // current point in the code.
2172 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2173 GrowableArray<ciInstanceKlass*>* exc_klasses,
2174 ciTypeFlow::StateVector* state) {
2175 int len = exceptions->length();
2176 assert(exc_klasses->length() == len, "must have same length");
2177 for (int i = 0; i < len; i++) {
2178 Block* block = exceptions->at(i);
2179 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2180
2181 if (!exception_klass->is_loaded()) {
2182 // Do not compile any code for unloaded exception types.
2183 // Following compiler passes are responsible for doing this also.
2184 continue;
2185 }
2186
2187 if (block->meet_exception(exception_klass, state)) {
2188 // Block was modified and has PO. Add it to the work list.
2189 if (block->has_post_order() &&
2190 !block->is_on_work_list()) {
2191 add_to_work_list(block);
2192 }
2193 }
2194 }
2195 }
2196
2197 // ------------------------------------------------------------------
2198 // ciTypeFlow::flow_successors
2199 //
2200 // Merge the current state into all successors at the current point
2201 // in the code.
2202 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2203 ciTypeFlow::StateVector* state) {
2204 int len = successors->length();
2205 for (int i = 0; i < len; i++) {
2206 Block* block = successors->at(i);
2207 if (block->meet(state)) {
2208 // Block was modified and has PO. Add it to the work list.
2209 if (block->has_post_order() &&
2210 !block->is_on_work_list()) {
2211 add_to_work_list(block);
2212 }
2213 }
2214 }
2215 }
2216
2217 // ------------------------------------------------------------------
2218 // ciTypeFlow::can_trap
2219 //
2220 // Tells if a given instruction is able to generate an exception edge.
2221 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2222 // Cf. GenerateOopMap::do_exception_edge.
2223 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2224
2225 switch (str.cur_bc()) {
2226 // %%% FIXME: ldc of Class can generate an exception
2227 case Bytecodes::_ldc:
2228 case Bytecodes::_ldc_w:
2229 case Bytecodes::_ldc2_w:
2230 case Bytecodes::_aload_0:
2231 // These bytecodes can trap for rewriting. We need to assume that
2232 // they do not throw exceptions to make the monitor analysis work.
2233 return false;
2234
2235 case Bytecodes::_ireturn:
2236 case Bytecodes::_lreturn:
2237 case Bytecodes::_freturn:
2238 case Bytecodes::_dreturn:
2239 case Bytecodes::_areturn:
2240 case Bytecodes::_vreturn:
2241 case Bytecodes::_return:
2242 // We can assume the monitor stack is empty in this analysis.
2243 return false;
2244
2245 case Bytecodes::_monitorexit:
2246 // We can assume monitors are matched in this analysis.
2247 return false;
2248 }
2249
2250 return true;
2251 }
2252
2253 // ------------------------------------------------------------------
2254 // ciTypeFlow::clone_loop_heads
2255 //
2256 // Clone the loop heads
2257 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2258 bool rslt = false;
2259 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2260 lp = iter.current();
2261 Block* head = lp->head();
2262 if (lp == loop_tree_root() ||
2263 lp->is_irreducible() ||
2264 !head->is_clonable_exit(lp))
2265 continue;
2266
2267 // Avoid BoxLock merge.
2268 if (EliminateNestedLocks && head->has_monitorenter())
2269 continue;
2270
2271 // check not already cloned
2272 if (head->backedge_copy_count() != 0)
2273 continue;
2274
2275 // Don't clone head of OSR loop to get correct types in start block.
2276 if (is_osr_flow() && head->start() == start_bci())
2277 continue;
2278
2279 // check _no_ shared head below us
2280 Loop* ch;
2281 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2282 if (ch != NULL)
2283 continue;
2284
2285 // Clone head
2286 Block* new_head = head->looping_succ(lp);
2287 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2288 // Update lp's info
2289 clone->set_loop(lp);
2290 lp->set_head(new_head);
2291 lp->set_tail(clone);
2292 // And move original head into outer loop
2293 head->set_loop(lp->parent());
2294
2295 rslt = true;
2296 }
2297 return rslt;
2298 }
2299
2300 // ------------------------------------------------------------------
2301 // ciTypeFlow::clone_loop_head
2302 //
2303 // Clone lp's head and replace tail's successors with clone.
2304 //
2305 // |
2306 // v
2307 // head <-> body
2308 // |
2309 // v
2310 // exit
2311 //
2312 // new_head
2313 //
2314 // |
2315 // v
2316 // head ----------\
2317 // | |
2318 // | v
2319 // | clone <-> body
2320 // | |
2321 // | /--/
2322 // | |
2323 // v v
2324 // exit
2325 //
2326 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2327 Block* head = lp->head();
2328 Block* tail = lp->tail();
2329 if (CITraceTypeFlow) {
2330 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2331 tty->print(" for predecessor "); tail->print_value_on(tty);
2332 tty->cr();
2333 }
2334 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2335 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2336
2337 assert(!clone->has_pre_order(), "just created");
2338 clone->set_next_pre_order();
2339
2340 // Insert clone after (orig) tail in reverse post order
2341 clone->set_rpo_next(tail->rpo_next());
2342 tail->set_rpo_next(clone);
2343
2344 // tail->head becomes tail->clone
2345 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2346 if (iter.succ() == head) {
2347 iter.set_succ(clone);
2348 // Update predecessor information
2349 head->predecessors()->remove(tail);
2350 clone->predecessors()->append(tail);
2351 }
2352 }
2353 flow_block(tail, temp_vector, temp_set);
2354 if (head == tail) {
2355 // For self-loops, clone->head becomes clone->clone
2356 flow_block(clone, temp_vector, temp_set);
2357 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2358 if (iter.succ() == head) {
2359 iter.set_succ(clone);
2360 // Update predecessor information
2361 head->predecessors()->remove(clone);
2362 clone->predecessors()->append(clone);
2363 break;
2364 }
2365 }
2366 }
2367 flow_block(clone, temp_vector, temp_set);
2368
2369 return clone;
2370 }
2371
2372 // ------------------------------------------------------------------
2373 // ciTypeFlow::flow_block
2374 //
2375 // Interpret the effects of the bytecodes on the incoming state
2376 // vector of a basic block. Push the changed state to succeeding
2377 // basic blocks.
2378 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2379 ciTypeFlow::StateVector* state,
2380 ciTypeFlow::JsrSet* jsrs) {
2381 if (CITraceTypeFlow) {
2382 tty->print("\n>> ANALYZING BLOCK : ");
2383 tty->cr();
2384 block->print_on(tty);
2385 }
2386 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2387
2388 int start = block->start();
2389 int limit = block->limit();
2390 int control = block->control();
2391 if (control != ciBlock::fall_through_bci) {
2392 limit = control;
2393 }
2394
2395 // Grab the state from the current block.
2396 block->copy_state_into(state);
2397 state->def_locals()->clear();
2398
2399 GrowableArray<Block*>* exceptions = block->exceptions();
2400 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2401 bool has_exceptions = exceptions->length() > 0;
2402
2403 bool exceptions_used = false;
2404
2405 ciBytecodeStream str(method());
2406 str.reset_to_bci(start);
2407 Bytecodes::Code code;
2408 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2409 str.cur_bci() < limit) {
2410 // Check for exceptional control flow from this point.
2411 if (has_exceptions && can_trap(str)) {
2412 flow_exceptions(exceptions, exc_klasses, state);
2413 exceptions_used = true;
2414 }
2415 // Apply the effects of the current bytecode to our state.
2416 bool res = state->apply_one_bytecode(&str);
2417
2418 // Watch for bailouts.
2419 if (failing()) return;
2420
2421 if (str.cur_bc() == Bytecodes::_monitorenter) {
2422 block->set_has_monitorenter();
2423 }
2424
2425 if (res) {
2426
2427 // We have encountered a trap. Record it in this block.
2428 block->set_trap(state->trap_bci(), state->trap_index());
2429
2430 if (CITraceTypeFlow) {
2431 tty->print_cr(">> Found trap");
2432 block->print_on(tty);
2433 }
2434
2435 // Save set of locals defined in this block
2436 block->def_locals()->add(state->def_locals());
2437
2438 // Record (no) successors.
2439 block->successors(&str, state, jsrs);
2440
2441 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2442
2443 // Discontinue interpretation of this Block.
2444 return;
2445 }
2446 }
2447
2448 GrowableArray<Block*>* successors = NULL;
2449 if (control != ciBlock::fall_through_bci) {
2450 // Check for exceptional control flow from this point.
2451 if (has_exceptions && can_trap(str)) {
2452 flow_exceptions(exceptions, exc_klasses, state);
2453 exceptions_used = true;
2454 }
2455
2456 // Fix the JsrSet to reflect effect of the bytecode.
2457 block->copy_jsrs_into(jsrs);
2458 jsrs->apply_control(this, &str, state);
2459
2460 // Find successor edges based on old state and new JsrSet.
2461 successors = block->successors(&str, state, jsrs);
2462
2463 // Apply the control changes to the state.
2464 state->apply_one_bytecode(&str);
2465 } else {
2466 // Fall through control
2467 successors = block->successors(&str, NULL, NULL);
2468 }
2469
2470 // Save set of locals defined in this block
2471 block->def_locals()->add(state->def_locals());
2472
2473 // Remove untaken exception paths
2474 if (!exceptions_used)
2475 exceptions->clear();
2476
2477 // Pass our state to successors.
2478 flow_successors(successors, state);
2479 }
2480
2481 // ------------------------------------------------------------------
2482 // ciTypeFlow::PostOrderLoops::next
2483 //
2484 // Advance to next loop tree using a postorder, left-to-right traversal.
2485 void ciTypeFlow::PostorderLoops::next() {
2486 assert(!done(), "must not be done.");
2487 if (_current->sibling() != NULL) {
2488 _current = _current->sibling();
2489 while (_current->child() != NULL) {
2490 _current = _current->child();
2491 }
2492 } else {
2493 _current = _current->parent();
2494 }
2495 }
2496
2497 // ------------------------------------------------------------------
2498 // ciTypeFlow::PreOrderLoops::next
2499 //
2500 // Advance to next loop tree using a preorder, left-to-right traversal.
2501 void ciTypeFlow::PreorderLoops::next() {
2502 assert(!done(), "must not be done.");
2503 if (_current->child() != NULL) {
2504 _current = _current->child();
2505 } else if (_current->sibling() != NULL) {
2506 _current = _current->sibling();
2507 } else {
2508 while (_current != _root && _current->sibling() == NULL) {
2509 _current = _current->parent();
2510 }
2511 if (_current == _root) {
2512 _current = NULL;
2513 assert(done(), "must be done.");
2514 } else {
2515 assert(_current->sibling() != NULL, "must be more to do");
2516 _current = _current->sibling();
2517 }
2518 }
2519 }
2520
2521 // ------------------------------------------------------------------
2522 // ciTypeFlow::Loop::sorted_merge
2523 //
2524 // Merge the branch lp into this branch, sorting on the loop head
2525 // pre_orders. Returns the leaf of the merged branch.
2526 // Child and sibling pointers will be setup later.
2527 // Sort is (looking from leaf towards the root)
2528 // descending on primary key: loop head's pre_order, and
2529 // ascending on secondary key: loop tail's pre_order.
2530 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2531 Loop* leaf = this;
2532 Loop* prev = NULL;
2533 Loop* current = leaf;
2534 while (lp != NULL) {
2535 int lp_pre_order = lp->head()->pre_order();
2536 // Find insertion point for "lp"
2537 while (current != NULL) {
2538 if (current == lp)
2539 return leaf; // Already in list
2540 if (current->head()->pre_order() < lp_pre_order)
2541 break;
2542 if (current->head()->pre_order() == lp_pre_order &&
2543 current->tail()->pre_order() > lp->tail()->pre_order()) {
2544 break;
2545 }
2546 prev = current;
2547 current = current->parent();
2548 }
2549 Loop* next_lp = lp->parent(); // Save future list of items to insert
2550 // Insert lp before current
2551 lp->set_parent(current);
2552 if (prev != NULL) {
2553 prev->set_parent(lp);
2554 } else {
2555 leaf = lp;
2556 }
2557 prev = lp; // Inserted item is new prev[ious]
2558 lp = next_lp; // Next item to insert
2559 }
2560 return leaf;
2561 }
2562
2563 // ------------------------------------------------------------------
2564 // ciTypeFlow::build_loop_tree
2565 //
2566 // Incrementally build loop tree.
2567 void ciTypeFlow::build_loop_tree(Block* blk) {
2568 assert(!blk->is_post_visited(), "precondition");
2569 Loop* innermost = NULL; // merge of loop tree branches over all successors
2570
2571 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2572 Loop* lp = NULL;
2573 Block* succ = iter.succ();
2574 if (!succ->is_post_visited()) {
2575 // Found backedge since predecessor post visited, but successor is not
2576 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2577
2578 // Create a LoopNode to mark this loop.
2579 lp = new (arena()) Loop(succ, blk);
2580 if (succ->loop() == NULL)
2581 succ->set_loop(lp);
2582 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2583
2584 } else { // Nested loop
2585 lp = succ->loop();
2586
2587 // If succ is loop head, find outer loop.
2588 while (lp != NULL && lp->head() == succ) {
2589 lp = lp->parent();
2590 }
2591 if (lp == NULL) {
2592 // Infinite loop, it's parent is the root
2593 lp = loop_tree_root();
2594 }
2595 }
2596
2597 // Check for irreducible loop.
2598 // Successor has already been visited. If the successor's loop head
2599 // has already been post-visited, then this is another entry into the loop.
2600 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2601 _has_irreducible_entry = true;
2602 lp->set_irreducible(succ);
2603 if (!succ->is_on_work_list()) {
2604 // Assume irreducible entries need more data flow
2605 add_to_work_list(succ);
2606 }
2607 Loop* plp = lp->parent();
2608 if (plp == NULL) {
2609 // This only happens for some irreducible cases. The parent
2610 // will be updated during a later pass.
2611 break;
2612 }
2613 lp = plp;
2614 }
2615
2616 // Merge loop tree branch for all successors.
2617 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2618
2619 } // end loop
2620
2621 if (innermost == NULL) {
2622 assert(blk->successors()->length() == 0, "CFG exit");
2623 blk->set_loop(loop_tree_root());
2624 } else if (innermost->head() == blk) {
2625 // If loop header, complete the tree pointers
2626 if (blk->loop() != innermost) {
2627 #ifdef ASSERT
2628 assert(blk->loop()->head() == innermost->head(), "same head");
2629 Loop* dl;
2630 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2631 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2632 #endif
2633 blk->set_loop(innermost);
2634 }
2635 innermost->def_locals()->add(blk->def_locals());
2636 Loop* l = innermost;
2637 Loop* p = l->parent();
2638 while (p && l->head() == blk) {
2639 l->set_sibling(p->child()); // Put self on parents 'next child'
2640 p->set_child(l); // Make self the first child of parent
2641 p->def_locals()->add(l->def_locals());
2642 l = p; // Walk up the parent chain
2643 p = l->parent();
2644 }
2645 } else {
2646 blk->set_loop(innermost);
2647 innermost->def_locals()->add(blk->def_locals());
2648 }
2649 }
2650
2651 // ------------------------------------------------------------------
2652 // ciTypeFlow::Loop::contains
2653 //
2654 // Returns true if lp is nested loop.
2655 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2656 assert(lp != NULL, "");
2657 if (this == lp || head() == lp->head()) return true;
2658 int depth1 = depth();
2659 int depth2 = lp->depth();
2660 if (depth1 > depth2)
2661 return false;
2662 while (depth1 < depth2) {
2663 depth2--;
2664 lp = lp->parent();
2665 }
2666 return this == lp;
2667 }
2668
2669 // ------------------------------------------------------------------
2670 // ciTypeFlow::Loop::depth
2671 //
2672 // Loop depth
2673 int ciTypeFlow::Loop::depth() const {
2674 int dp = 0;
2675 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2676 dp++;
2677 return dp;
2678 }
2679
2680 #ifndef PRODUCT
2681 // ------------------------------------------------------------------
2682 // ciTypeFlow::Loop::print
2683 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2684 for (int i = 0; i < indent; i++) st->print(" ");
2685 st->print("%d<-%d %s",
2686 is_root() ? 0 : this->head()->pre_order(),
2687 is_root() ? 0 : this->tail()->pre_order(),
2688 is_irreducible()?" irr":"");
2689 st->print(" defs: ");
2690 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2691 st->cr();
2692 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2693 ch->print(st, indent+2);
2694 }
2695 #endif
2696
2697 // ------------------------------------------------------------------
2698 // ciTypeFlow::df_flow_types
2699 //
2700 // Perform the depth first type flow analysis. Helper for flow_types.
2701 void ciTypeFlow::df_flow_types(Block* start,
2702 bool do_flow,
2703 StateVector* temp_vector,
2704 JsrSet* temp_set) {
2705 int dft_len = 100;
2706 GrowableArray<Block*> stk(dft_len);
2707
2708 ciBlock* dummy = _methodBlocks->make_dummy_block();
2709 JsrSet* root_set = new JsrSet(NULL, 0);
2710 Block* root_head = new (arena()) Block(this, dummy, root_set);
2711 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2712 root_head->set_pre_order(0);
2713 root_head->set_post_order(0);
2714 root_tail->set_pre_order(max_jint);
2715 root_tail->set_post_order(max_jint);
2716 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2717
2718 stk.push(start);
2719
2720 _next_pre_order = 0; // initialize pre_order counter
2721 _rpo_list = NULL;
2722 int next_po = 0; // initialize post_order counter
2723
2724 // Compute RPO and the control flow graph
2725 int size;
2726 while ((size = stk.length()) > 0) {
2727 Block* blk = stk.top(); // Leave node on stack
2728 if (!blk->is_visited()) {
2729 // forward arc in graph
2730 assert (!blk->has_pre_order(), "");
2731 blk->set_next_pre_order();
2732
2733 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2734 // Too many basic blocks. Bail out.
2735 // This can happen when try/finally constructs are nested to depth N,
2736 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2737 // "MaxNodeLimit / 2" is used because probably the parser will
2738 // generate at least twice that many nodes and bail out.
2739 record_failure("too many basic blocks");
2740 return;
2741 }
2742 if (do_flow) {
2743 flow_block(blk, temp_vector, temp_set);
2744 if (failing()) return; // Watch for bailouts.
2745 }
2746 } else if (!blk->is_post_visited()) {
2747 // cross or back arc
2748 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2749 Block* succ = iter.succ();
2750 if (!succ->is_visited()) {
2751 stk.push(succ);
2752 }
2753 }
2754 if (stk.length() == size) {
2755 // There were no additional children, post visit node now
2756 stk.pop(); // Remove node from stack
2757
2758 build_loop_tree(blk);
2759 blk->set_post_order(next_po++); // Assign post order
2760 prepend_to_rpo_list(blk);
2761 assert(blk->is_post_visited(), "");
2762
2763 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2764 // Assume loop heads need more data flow
2765 add_to_work_list(blk);
2766 }
2767 }
2768 } else {
2769 stk.pop(); // Remove post-visited node from stack
2770 }
2771 }
2772 }
2773
2774 // ------------------------------------------------------------------
2775 // ciTypeFlow::flow_types
2776 //
2777 // Perform the type flow analysis, creating and cloning Blocks as
2778 // necessary.
2779 void ciTypeFlow::flow_types() {
2780 ResourceMark rm;
2781 StateVector* temp_vector = new StateVector(this);
2782 JsrSet* temp_set = new JsrSet(NULL, 16);
2783
2784 // Create the method entry block.
2785 Block* start = block_at(start_bci(), temp_set);
2786
2787 // Load the initial state into it.
2788 const StateVector* start_state = get_start_state();
2789 if (failing()) return;
2790 start->meet(start_state);
2791
2792 // Depth first visit
2793 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2794
2795 if (failing()) return;
2796 assert(_rpo_list == start, "must be start");
2797
2798 // Any loops found?
2799 if (loop_tree_root()->child() != NULL &&
2800 env()->comp_level() >= CompLevel_full_optimization) {
2801 // Loop optimizations are not performed on Tier1 compiles.
2802
2803 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2804
2805 // If some loop heads were cloned, recompute postorder and loop tree
2806 if (changed) {
2807 loop_tree_root()->set_child(NULL);
2808 for (Block* blk = _rpo_list; blk != NULL;) {
2809 Block* next = blk->rpo_next();
2810 blk->df_init();
2811 blk = next;
2812 }
2813 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2814 }
2815 }
2816
2817 if (CITraceTypeFlow) {
2818 tty->print_cr("\nLoop tree");
2819 loop_tree_root()->print();
2820 }
2821
2822 // Continue flow analysis until fixed point reached
2823
2824 debug_only(int max_block = _next_pre_order;)
2825
2826 while (!work_list_empty()) {
2827 Block* blk = work_list_next();
2828 assert (blk->has_post_order(), "post order assigned above");
2829
2830 flow_block(blk, temp_vector, temp_set);
2831
2832 assert (max_block == _next_pre_order, "no new blocks");
2833 assert (!failing(), "no more bailouts");
2834 }
2835 }
2836
2837 // ------------------------------------------------------------------
2838 // ciTypeFlow::map_blocks
2839 //
2840 // Create the block map, which indexes blocks in reverse post-order.
2841 void ciTypeFlow::map_blocks() {
2842 assert(_block_map == NULL, "single initialization");
2843 int block_ct = _next_pre_order;
2844 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2845 assert(block_ct == block_count(), "");
2846
2847 Block* blk = _rpo_list;
2848 for (int m = 0; m < block_ct; m++) {
2849 int rpo = blk->rpo();
2850 assert(rpo == m, "should be sequential");
2851 _block_map[rpo] = blk;
2852 blk = blk->rpo_next();
2853 }
2854 assert(blk == NULL, "should be done");
2855
2856 for (int j = 0; j < block_ct; j++) {
2857 assert(_block_map[j] != NULL, "must not drop any blocks");
2858 Block* block = _block_map[j];
2859 // Remove dead blocks from successor lists:
2860 for (int e = 0; e <= 1; e++) {
2861 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2862 for (int k = 0; k < l->length(); k++) {
2863 Block* s = l->at(k);
2864 if (!s->has_post_order()) {
2865 if (CITraceTypeFlow) {
2866 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2867 s->print_value_on(tty);
2868 tty->cr();
2869 }
2870 l->remove(s);
2871 --k;
2872 }
2873 }
2874 }
2875 }
2876 }
2877
2878 // ------------------------------------------------------------------
2879 // ciTypeFlow::get_block_for
2880 //
2881 // Find a block with this ciBlock which has a compatible JsrSet.
2882 // If no such block exists, create it, unless the option is no_create.
2883 // If the option is create_backedge_copy, always create a fresh backedge copy.
2884 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2885 Arena* a = arena();
2886 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2887 if (blocks == NULL) {
2888 // Query only?
2889 if (option == no_create) return NULL;
2890
2891 // Allocate the growable array.
2892 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2893 _idx_to_blocklist[ciBlockIndex] = blocks;
2894 }
2895
2896 if (option != create_backedge_copy) {
2897 int len = blocks->length();
2898 for (int i = 0; i < len; i++) {
2899 Block* block = blocks->at(i);
2900 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2901 return block;
2902 }
2903 }
2904 }
2905
2906 // Query only?
2907 if (option == no_create) return NULL;
2908
2909 // We did not find a compatible block. Create one.
2910 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2911 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2912 blocks->append(new_block);
2913 return new_block;
2914 }
2915
2916 // ------------------------------------------------------------------
2917 // ciTypeFlow::backedge_copy_count
2918 //
2919 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2920 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2921
2922 if (blocks == NULL) {
2923 return 0;
2924 }
2925
2926 int count = 0;
2927 int len = blocks->length();
2928 for (int i = 0; i < len; i++) {
2929 Block* block = blocks->at(i);
2930 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2931 count++;
2932 }
2933 }
2934
2935 return count;
2936 }
2937
2938 // ------------------------------------------------------------------
2939 // ciTypeFlow::do_flow
2940 //
2941 // Perform type inference flow analysis.
2942 void ciTypeFlow::do_flow() {
2943 if (CITraceTypeFlow) {
2944 tty->print_cr("\nPerforming flow analysis on method");
2945 method()->print();
2946 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2947 tty->cr();
2948 method()->print_codes();
2949 }
2950 if (CITraceTypeFlow) {
2951 tty->print_cr("Initial CI Blocks");
2952 print_on(tty);
2953 }
2954 flow_types();
2955 // Watch for bailouts.
2956 if (failing()) {
2957 return;
2958 }
2959
2960 map_blocks();
2961
2962 if (CIPrintTypeFlow || CITraceTypeFlow) {
2963 rpo_print_on(tty);
2964 }
2965 }
2966
2967 // ------------------------------------------------------------------
2968 // ciTypeFlow::is_dominated_by
2969 //
2970 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
2971 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
2972 assert(!method()->has_jsrs(), "jsrs are not supported");
2973
2974 ResourceMark rm;
2975 JsrSet* jsrs = new ciTypeFlow::JsrSet(NULL);
2976 int index = _methodBlocks->block_containing(bci)->index();
2977 int dom_index = _methodBlocks->block_containing(dom_bci)->index();
2978 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
2979 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
2980
2981 // Start block dominates all other blocks
2982 if (start_block()->rpo() == dom_block->rpo()) {
2983 return true;
2984 }
2985
2986 // Dominated[i] is true if block i is dominated by dom_block
2987 int num_blocks = block_count();
2988 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
2989 for (int i = 0; i < num_blocks; ++i) {
2990 dominated[i] = true;
2991 }
2992 dominated[start_block()->rpo()] = false;
2993
2994 // Iterative dominator algorithm
2995 bool changed = true;
2996 while (changed) {
2997 changed = false;
2998 // Use reverse postorder iteration
2999 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3000 if (blk->is_start()) {
3001 // Ignore start block
3002 continue;
3003 }
3004 // The block is dominated if it is the dominating block
3005 // itself or if all predecessors are dominated.
3006 int index = blk->rpo();
3007 bool dom = (index == dom_block->rpo());
3008 if (!dom) {
3009 // Check if all predecessors are dominated
3010 dom = true;
3011 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3012 Block* pred = blk->predecessors()->at(i);
3013 if (!dominated[pred->rpo()]) {
3014 dom = false;
3015 break;
3016 }
3017 }
3018 }
3019 // Update dominator information
3020 if (dominated[index] != dom) {
3021 changed = true;
3022 dominated[index] = dom;
3023 }
3024 }
3025 }
3026 // block dominated by dom_block?
3027 return dominated[block->rpo()];
3028 }
3029
3030 // ------------------------------------------------------------------
3031 // ciTypeFlow::record_failure()
3032 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3033 // This is required because there is not a 1-1 relation between the ciEnv and
3034 // the TypeFlow passes within a compilation task. For example, if the compiler
3035 // is considering inlining a method, it will request a TypeFlow. If that fails,
3036 // the compilation as a whole may continue without the inlining. Some TypeFlow
3037 // requests are not optional; if they fail the requestor is responsible for
3038 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3039 void ciTypeFlow::record_failure(const char* reason) {
3040 if (env()->log() != NULL) {
3041 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3042 }
3043 if (_failure_reason == NULL) {
3044 // Record the first failure reason.
3045 _failure_reason = reason;
3046 }
3047 }
3048
3049 #ifndef PRODUCT
3050 // ------------------------------------------------------------------
3051 // ciTypeFlow::print_on
3052 void ciTypeFlow::print_on(outputStream* st) const {
3053 // Walk through CI blocks
3054 st->print_cr("********************************************************");
3055 st->print ("TypeFlow for ");
3056 method()->name()->print_symbol_on(st);
3057 int limit_bci = code_size();
3058 st->print_cr(" %d bytes", limit_bci);
3059 ciMethodBlocks *mblks = _methodBlocks;
3060 ciBlock* current = NULL;
3061 for (int bci = 0; bci < limit_bci; bci++) {
3062 ciBlock* blk = mblks->block_containing(bci);
3063 if (blk != NULL && blk != current) {
3064 current = blk;
3065 current->print_on(st);
3066
3067 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3068 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
3069
3070 if (num_blocks == 0) {
3071 st->print_cr(" No Blocks");
3072 } else {
3073 for (int i = 0; i < num_blocks; i++) {
3074 Block* block = blocks->at(i);
3075 block->print_on(st);
3076 }
3077 }
3078 st->print_cr("--------------------------------------------------------");
3079 st->cr();
3080 }
3081 }
3082 st->print_cr("********************************************************");
3083 st->cr();
3084 }
3085
3086 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3087 st->print_cr("********************************************************");
3088 st->print ("TypeFlow for ");
3089 method()->name()->print_symbol_on(st);
3090 int limit_bci = code_size();
3091 st->print_cr(" %d bytes", limit_bci);
3092 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3093 blk->print_on(st);
3094 st->print_cr("--------------------------------------------------------");
3095 st->cr();
3096 }
3097 st->print_cr("********************************************************");
3098 st->cr();
3099 }
3100 #endif