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_aaload
551 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
552 pop_int();
553 ciObjArrayKlass* array_klass = pop_objArray();
554 if (array_klass == NULL) {
555 // Did aaload 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_newarray
774 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
775 pop_int();
776 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
777 push_object(klass);
778 }
779
780 // ------------------------------------------------------------------
781 // ciTypeFlow::StateVector::do_putfield
782 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
783 do_putstatic(str);
784 if (_trap_bci != -1) return; // unloaded field holder, etc.
785 // could add assert here for type of object.
786 pop_object();
787 }
788
789 // ------------------------------------------------------------------
790 // ciTypeFlow::StateVector::do_putstatic
791 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
792 bool will_link;
793 ciField* field = str->get_field(will_link);
794 if (!will_link) {
795 trap(str, field->holder(), str->get_field_holder_index());
796 } else {
797 ciType* field_type = field->type();
798 ciType* type = pop_value();
799 // Do I want to check this type?
800 // assert(type->is_subtype_of(field_type), "bad type for field value");
801 if (field_type->is_two_word()) {
802 ciType* type2 = pop_value();
803 assert(type2->is_two_word(), "must be 2nd half");
804 assert(type == half_type(type2), "must be 2nd half");
805 }
806 }
807 }
808
809 // ------------------------------------------------------------------
810 // ciTypeFlow::StateVector::do_ret
811 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
812 Cell index = local(str->get_index());
813
814 ciType* address = type_at(index);
815 assert(address->is_return_address(), "bad return address");
816 set_type_at(index, bottom_type());
817 }
818
819 // ------------------------------------------------------------------
820 // ciTypeFlow::StateVector::trap
821 //
822 // Stop interpretation of this path with a trap.
823 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
824 _trap_bci = str->cur_bci();
825 _trap_index = index;
826
827 // Log information about this trap:
828 CompileLog* log = outer()->env()->log();
829 if (log != NULL) {
830 int mid = log->identify(outer()->method());
831 int kid = (klass == NULL)? -1: log->identify(klass);
832 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
833 char buf[100];
834 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
835 index));
836 if (kid >= 0)
837 log->print(" klass='%d'", kid);
838 log->end_elem();
839 }
840 }
841
842 // ------------------------------------------------------------------
843 // ciTypeFlow::StateVector::do_null_assert
844 // Corresponds to graphKit::do_null_assert.
845 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
846 if (unloaded_klass->is_loaded()) {
847 // We failed to link, but we can still compute with this class,
848 // since it is loaded somewhere. The compiler will uncommon_trap
849 // if the object is not null, but the typeflow pass can not assume
850 // that the object will be null, otherwise it may incorrectly tell
851 // the parser that an object is known to be null. 4761344, 4807707
852 push_object(unloaded_klass);
853 } else {
854 // The class is not loaded anywhere. It is safe to model the
855 // null in the typestates, because we can compile in a null check
856 // which will deoptimize us if someone manages to load the
857 // class later.
858 push_null();
859 }
860 }
861
862
863 // ------------------------------------------------------------------
864 // ciTypeFlow::StateVector::apply_one_bytecode
865 //
866 // Apply the effect of one bytecode to this StateVector
867 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
868 _trap_bci = -1;
869 _trap_index = 0;
870
871 if (CITraceTypeFlow) {
872 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
873 Bytecodes::name(str->cur_bc()));
874 }
875
876 switch(str->cur_bc()) {
877 case Bytecodes::_aaload: do_aaload(str); break;
878
879 case Bytecodes::_aastore:
880 {
881 pop_object();
882 pop_int();
883 pop_objArray();
884 break;
885 }
886 case Bytecodes::_aconst_null:
887 {
888 push_null();
889 break;
890 }
891 case Bytecodes::_aload: load_local_object(str->get_index()); break;
892 case Bytecodes::_aload_0: load_local_object(0); break;
893 case Bytecodes::_aload_1: load_local_object(1); break;
894 case Bytecodes::_aload_2: load_local_object(2); break;
895 case Bytecodes::_aload_3: load_local_object(3); break;
896
897 case Bytecodes::_anewarray:
898 {
899 pop_int();
900 bool will_link;
901 ciKlass* element_klass = str->get_klass(will_link);
902 if (!will_link) {
903 trap(str, element_klass, str->get_klass_index());
904 } else {
905 push_object(ciObjArrayKlass::make(element_klass));
906 }
907 break;
908 }
909 case Bytecodes::_areturn:
910 case Bytecodes::_ifnonnull:
911 case Bytecodes::_ifnull:
912 {
913 pop_object();
914 break;
915 }
916 case Bytecodes::_monitorenter:
917 {
918 pop_object();
919 set_monitor_count(monitor_count() + 1);
920 break;
921 }
922 case Bytecodes::_monitorexit:
923 {
924 pop_object();
925 assert(monitor_count() > 0, "must be a monitor to exit from");
926 set_monitor_count(monitor_count() - 1);
927 break;
928 }
929 case Bytecodes::_arraylength:
930 {
931 pop_array();
932 push_int();
933 break;
934 }
935 case Bytecodes::_astore: store_local_object(str->get_index()); break;
936 case Bytecodes::_astore_0: store_local_object(0); break;
937 case Bytecodes::_astore_1: store_local_object(1); break;
938 case Bytecodes::_astore_2: store_local_object(2); break;
939 case Bytecodes::_astore_3: store_local_object(3); break;
940
941 case Bytecodes::_athrow:
942 {
943 NEEDS_CLEANUP;
944 pop_object();
945 break;
946 }
947 case Bytecodes::_baload:
948 case Bytecodes::_caload:
949 case Bytecodes::_iaload:
950 case Bytecodes::_saload:
951 {
952 pop_int();
953 ciTypeArrayKlass* array_klass = pop_typeArray();
954 // Put assert here for right type?
955 push_int();
956 break;
957 }
958 case Bytecodes::_bastore:
959 case Bytecodes::_castore:
960 case Bytecodes::_iastore:
961 case Bytecodes::_sastore:
962 {
963 pop_int();
964 pop_int();
965 pop_typeArray();
966 // assert here?
967 break;
968 }
969 case Bytecodes::_bipush:
970 case Bytecodes::_iconst_m1:
971 case Bytecodes::_iconst_0:
972 case Bytecodes::_iconst_1:
973 case Bytecodes::_iconst_2:
974 case Bytecodes::_iconst_3:
975 case Bytecodes::_iconst_4:
976 case Bytecodes::_iconst_5:
977 case Bytecodes::_sipush:
978 {
979 push_int();
980 break;
981 }
982 case Bytecodes::_checkcast: do_checkcast(str); break;
983
984 case Bytecodes::_d2f:
985 {
986 pop_double();
987 push_float();
988 break;
989 }
990 case Bytecodes::_d2i:
991 {
992 pop_double();
993 push_int();
994 break;
995 }
996 case Bytecodes::_d2l:
997 {
998 pop_double();
999 push_long();
1000 break;
1001 }
1002 case Bytecodes::_dadd:
1003 case Bytecodes::_ddiv:
1004 case Bytecodes::_dmul:
1005 case Bytecodes::_drem:
1006 case Bytecodes::_dsub:
1007 {
1008 pop_double();
1009 pop_double();
1010 push_double();
1011 break;
1012 }
1013 case Bytecodes::_daload:
1014 {
1015 pop_int();
1016 ciTypeArrayKlass* array_klass = pop_typeArray();
1017 // Put assert here for right type?
1018 push_double();
1019 break;
1020 }
1021 case Bytecodes::_dastore:
1022 {
1023 pop_double();
1024 pop_int();
1025 pop_typeArray();
1026 // assert here?
1027 break;
1028 }
1029 case Bytecodes::_dcmpg:
1030 case Bytecodes::_dcmpl:
1031 {
1032 pop_double();
1033 pop_double();
1034 push_int();
1035 break;
1036 }
1037 case Bytecodes::_dconst_0:
1038 case Bytecodes::_dconst_1:
1039 {
1040 push_double();
1041 break;
1042 }
1043 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1044 case Bytecodes::_dload_0: load_local_double(0); break;
1045 case Bytecodes::_dload_1: load_local_double(1); break;
1046 case Bytecodes::_dload_2: load_local_double(2); break;
1047 case Bytecodes::_dload_3: load_local_double(3); break;
1048
1049 case Bytecodes::_dneg:
1050 {
1051 pop_double();
1052 push_double();
1053 break;
1054 }
1055 case Bytecodes::_dreturn:
1056 {
1057 pop_double();
1058 break;
1059 }
1060 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1061 case Bytecodes::_dstore_0: store_local_double(0); break;
1062 case Bytecodes::_dstore_1: store_local_double(1); break;
1063 case Bytecodes::_dstore_2: store_local_double(2); break;
1064 case Bytecodes::_dstore_3: store_local_double(3); break;
1065
1066 case Bytecodes::_dup:
1067 {
1068 push(type_at_tos());
1069 break;
1070 }
1071 case Bytecodes::_dup_x1:
1072 {
1073 ciType* value1 = pop_value();
1074 ciType* value2 = pop_value();
1075 push(value1);
1076 push(value2);
1077 push(value1);
1078 break;
1079 }
1080 case Bytecodes::_dup_x2:
1081 {
1082 ciType* value1 = pop_value();
1083 ciType* value2 = pop_value();
1084 ciType* value3 = pop_value();
1085 push(value1);
1086 push(value3);
1087 push(value2);
1088 push(value1);
1089 break;
1090 }
1091 case Bytecodes::_dup2:
1092 {
1093 ciType* value1 = pop_value();
1094 ciType* value2 = pop_value();
1095 push(value2);
1096 push(value1);
1097 push(value2);
1098 push(value1);
1099 break;
1100 }
1101 case Bytecodes::_dup2_x1:
1102 {
1103 ciType* value1 = pop_value();
1104 ciType* value2 = pop_value();
1105 ciType* value3 = pop_value();
1106 push(value2);
1107 push(value1);
1108 push(value3);
1109 push(value2);
1110 push(value1);
1111 break;
1112 }
1113 case Bytecodes::_dup2_x2:
1114 {
1115 ciType* value1 = pop_value();
1116 ciType* value2 = pop_value();
1117 ciType* value3 = pop_value();
1118 ciType* value4 = pop_value();
1119 push(value2);
1120 push(value1);
1121 push(value4);
1122 push(value3);
1123 push(value2);
1124 push(value1);
1125 break;
1126 }
1127 case Bytecodes::_f2d:
1128 {
1129 pop_float();
1130 push_double();
1131 break;
1132 }
1133 case Bytecodes::_f2i:
1134 {
1135 pop_float();
1136 push_int();
1137 break;
1138 }
1139 case Bytecodes::_f2l:
1140 {
1141 pop_float();
1142 push_long();
1143 break;
1144 }
1145 case Bytecodes::_fadd:
1146 case Bytecodes::_fdiv:
1147 case Bytecodes::_fmul:
1148 case Bytecodes::_frem:
1149 case Bytecodes::_fsub:
1150 {
1151 pop_float();
1152 pop_float();
1153 push_float();
1154 break;
1155 }
1156 case Bytecodes::_faload:
1157 {
1158 pop_int();
1159 ciTypeArrayKlass* array_klass = pop_typeArray();
1160 // Put assert here.
1161 push_float();
1162 break;
1163 }
1164 case Bytecodes::_fastore:
1165 {
1166 pop_float();
1167 pop_int();
1168 ciTypeArrayKlass* array_klass = pop_typeArray();
1169 // Put assert here.
1170 break;
1171 }
1172 case Bytecodes::_fcmpg:
1173 case Bytecodes::_fcmpl:
1174 {
1175 pop_float();
1176 pop_float();
1177 push_int();
1178 break;
1179 }
1180 case Bytecodes::_fconst_0:
1181 case Bytecodes::_fconst_1:
1182 case Bytecodes::_fconst_2:
1183 {
1184 push_float();
1185 break;
1186 }
1187 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1188 case Bytecodes::_fload_0: load_local_float(0); break;
1189 case Bytecodes::_fload_1: load_local_float(1); break;
1190 case Bytecodes::_fload_2: load_local_float(2); break;
1191 case Bytecodes::_fload_3: load_local_float(3); break;
1192
1193 case Bytecodes::_fneg:
1194 {
1195 pop_float();
1196 push_float();
1197 break;
1198 }
1199 case Bytecodes::_freturn:
1200 {
1201 pop_float();
1202 break;
1203 }
1204 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1205 case Bytecodes::_fstore_0: store_local_float(0); break;
1206 case Bytecodes::_fstore_1: store_local_float(1); break;
1207 case Bytecodes::_fstore_2: store_local_float(2); break;
1208 case Bytecodes::_fstore_3: store_local_float(3); break;
1209
1210 case Bytecodes::_getfield: do_getfield(str); break;
1211 case Bytecodes::_getstatic: do_getstatic(str); break;
1212
1213 case Bytecodes::_goto:
1214 case Bytecodes::_goto_w:
1215 case Bytecodes::_nop:
1216 case Bytecodes::_return:
1217 {
1218 // do nothing.
1219 break;
1220 }
1221 case Bytecodes::_i2b:
1222 case Bytecodes::_i2c:
1223 case Bytecodes::_i2s:
1224 case Bytecodes::_ineg:
1225 {
1226 pop_int();
1227 push_int();
1228 break;
1229 }
1230 case Bytecodes::_i2d:
1231 {
1232 pop_int();
1233 push_double();
1234 break;
1235 }
1236 case Bytecodes::_i2f:
1237 {
1238 pop_int();
1239 push_float();
1240 break;
1241 }
1242 case Bytecodes::_i2l:
1243 {
1244 pop_int();
1245 push_long();
1246 break;
1247 }
1248 case Bytecodes::_iadd:
1249 case Bytecodes::_iand:
1250 case Bytecodes::_idiv:
1251 case Bytecodes::_imul:
1252 case Bytecodes::_ior:
1253 case Bytecodes::_irem:
1254 case Bytecodes::_ishl:
1255 case Bytecodes::_ishr:
1256 case Bytecodes::_isub:
1257 case Bytecodes::_iushr:
1258 case Bytecodes::_ixor:
1259 {
1260 pop_int();
1261 pop_int();
1262 push_int();
1263 break;
1264 }
1265 case Bytecodes::_if_acmpeq:
1266 case Bytecodes::_if_acmpne:
1267 {
1268 pop_object();
1269 pop_object();
1270 break;
1271 }
1272 case Bytecodes::_if_icmpeq:
1273 case Bytecodes::_if_icmpge:
1274 case Bytecodes::_if_icmpgt:
1275 case Bytecodes::_if_icmple:
1276 case Bytecodes::_if_icmplt:
1277 case Bytecodes::_if_icmpne:
1278 {
1279 pop_int();
1280 pop_int();
1281 break;
1282 }
1283 case Bytecodes::_ifeq:
1284 case Bytecodes::_ifle:
1285 case Bytecodes::_iflt:
1286 case Bytecodes::_ifge:
1287 case Bytecodes::_ifgt:
1288 case Bytecodes::_ifne:
1289 case Bytecodes::_ireturn:
1290 case Bytecodes::_lookupswitch:
1291 case Bytecodes::_tableswitch:
1292 {
1293 pop_int();
1294 break;
1295 }
1296 case Bytecodes::_iinc:
1297 {
1298 int lnum = str->get_index();
1299 check_int(local(lnum));
1300 store_to_local(lnum);
1301 break;
1302 }
1303 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1304 case Bytecodes::_iload_0: load_local_int(0); break;
1305 case Bytecodes::_iload_1: load_local_int(1); break;
1306 case Bytecodes::_iload_2: load_local_int(2); break;
1307 case Bytecodes::_iload_3: load_local_int(3); break;
1308
1309 case Bytecodes::_instanceof:
1310 {
1311 // Check for uncommon trap:
1312 do_checkcast(str);
1313 pop_object();
1314 push_int();
1315 break;
1316 }
1317 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1318 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1319 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1320 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1321 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1322
1323 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1324 case Bytecodes::_istore_0: store_local_int(0); break;
1325 case Bytecodes::_istore_1: store_local_int(1); break;
1326 case Bytecodes::_istore_2: store_local_int(2); break;
1327 case Bytecodes::_istore_3: store_local_int(3); break;
1328
1329 case Bytecodes::_jsr:
1330 case Bytecodes::_jsr_w: do_jsr(str); break;
1331
1332 case Bytecodes::_l2d:
1333 {
1334 pop_long();
1335 push_double();
1336 break;
1337 }
1338 case Bytecodes::_l2f:
1339 {
1340 pop_long();
1341 push_float();
1342 break;
1343 }
1344 case Bytecodes::_l2i:
1345 {
1346 pop_long();
1347 push_int();
1348 break;
1349 }
1350 case Bytecodes::_ladd:
1351 case Bytecodes::_land:
1352 case Bytecodes::_ldiv:
1353 case Bytecodes::_lmul:
1354 case Bytecodes::_lor:
1355 case Bytecodes::_lrem:
1356 case Bytecodes::_lsub:
1357 case Bytecodes::_lxor:
1358 {
1359 pop_long();
1360 pop_long();
1361 push_long();
1362 break;
1363 }
1364 case Bytecodes::_laload:
1365 {
1366 pop_int();
1367 ciTypeArrayKlass* array_klass = pop_typeArray();
1368 // Put assert here for right type?
1369 push_long();
1370 break;
1371 }
1372 case Bytecodes::_lastore:
1373 {
1374 pop_long();
1375 pop_int();
1376 pop_typeArray();
1377 // assert here?
1378 break;
1379 }
1380 case Bytecodes::_lcmp:
1381 {
1382 pop_long();
1383 pop_long();
1384 push_int();
1385 break;
1386 }
1387 case Bytecodes::_lconst_0:
1388 case Bytecodes::_lconst_1:
1389 {
1390 push_long();
1391 break;
1392 }
1393 case Bytecodes::_ldc:
1394 case Bytecodes::_ldc_w:
1395 case Bytecodes::_ldc2_w:
1396 {
1397 do_ldc(str);
1398 break;
1399 }
1400
1401 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1402 case Bytecodes::_lload_0: load_local_long(0); break;
1403 case Bytecodes::_lload_1: load_local_long(1); break;
1404 case Bytecodes::_lload_2: load_local_long(2); break;
1405 case Bytecodes::_lload_3: load_local_long(3); break;
1406
1407 case Bytecodes::_lneg:
1408 {
1409 pop_long();
1410 push_long();
1411 break;
1412 }
1413 case Bytecodes::_lreturn:
1414 {
1415 pop_long();
1416 break;
1417 }
1418 case Bytecodes::_lshl:
1419 case Bytecodes::_lshr:
1420 case Bytecodes::_lushr:
1421 {
1422 pop_int();
1423 pop_long();
1424 push_long();
1425 break;
1426 }
1427 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1428 case Bytecodes::_lstore_0: store_local_long(0); break;
1429 case Bytecodes::_lstore_1: store_local_long(1); break;
1430 case Bytecodes::_lstore_2: store_local_long(2); break;
1431 case Bytecodes::_lstore_3: store_local_long(3); break;
1432
1433 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1434
1435 case Bytecodes::_new: do_new(str); break;
1436
1437 case Bytecodes::_newarray: do_newarray(str); break;
1438
1439 case Bytecodes::_pop:
1440 {
1441 pop();
1442 break;
1443 }
1444 case Bytecodes::_pop2:
1445 {
1446 pop();
1447 pop();
1448 break;
1449 }
1450
1451 case Bytecodes::_putfield: do_putfield(str); break;
1452 case Bytecodes::_putstatic: do_putstatic(str); break;
1453
1454 case Bytecodes::_ret: do_ret(str); break;
1455
1456 case Bytecodes::_swap:
1457 {
1458 ciType* value1 = pop_value();
1459 ciType* value2 = pop_value();
1460 push(value1);
1461 push(value2);
1462 break;
1463 }
1464 case Bytecodes::_wide:
1465 default:
1466 {
1467 // The iterator should skip this.
1468 ShouldNotReachHere();
1469 break;
1470 }
1471 }
1472
1473 if (CITraceTypeFlow) {
1474 print_on(tty);
1475 }
1476
1477 return (_trap_bci != -1);
1478 }
1479
1480 #ifndef PRODUCT
1481 // ------------------------------------------------------------------
1482 // ciTypeFlow::StateVector::print_cell_on
1483 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1484 ciType* type = type_at(c);
1485 if (type == top_type()) {
1486 st->print("top");
1487 } else if (type == bottom_type()) {
1488 st->print("bottom");
1489 } else if (type == null_type()) {
1490 st->print("null");
1491 } else if (type == long2_type()) {
1492 st->print("long2");
1493 } else if (type == double2_type()) {
1494 st->print("double2");
1495 } else if (is_int(type)) {
1496 st->print("int");
1497 } else if (is_long(type)) {
1498 st->print("long");
1499 } else if (is_float(type)) {
1500 st->print("float");
1501 } else if (is_double(type)) {
1502 st->print("double");
1503 } else if (type->is_return_address()) {
1504 st->print("address(%d)", type->as_return_address()->bci());
1505 } else {
1506 if (type->is_klass()) {
1507 type->as_klass()->name()->print_symbol_on(st);
1508 } else {
1509 st->print("UNEXPECTED TYPE");
1510 type->print();
1511 }
1512 }
1513 }
1514
1515 // ------------------------------------------------------------------
1516 // ciTypeFlow::StateVector::print_on
1517 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1518 int num_locals = _outer->max_locals();
1519 int num_stack = stack_size();
1520 int num_monitors = monitor_count();
1521 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1522 if (num_stack >= 0) {
1523 int i;
1524 for (i = 0; i < num_locals; i++) {
1525 st->print(" local %2d : ", i);
1526 print_cell_on(st, local(i));
1527 st->cr();
1528 }
1529 for (i = 0; i < num_stack; i++) {
1530 st->print(" stack %2d : ", i);
1531 print_cell_on(st, stack(i));
1532 st->cr();
1533 }
1534 }
1535 }
1536 #endif
1537
1538
1539 // ------------------------------------------------------------------
1540 // ciTypeFlow::SuccIter::next
1541 //
1542 void ciTypeFlow::SuccIter::next() {
1543 int succ_ct = _pred->successors()->length();
1544 int next = _index + 1;
1545 if (next < succ_ct) {
1546 _index = next;
1547 _succ = _pred->successors()->at(next);
1548 return;
1549 }
1550 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1551 // Do not compile any code for unloaded exception types.
1552 // Following compiler passes are responsible for doing this also.
1553 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1554 if (exception_klass->is_loaded()) {
1555 _index = next;
1556 _succ = _pred->exceptions()->at(i);
1557 return;
1558 }
1559 next++;
1560 }
1561 _index = -1;
1562 _succ = NULL;
1563 }
1564
1565 // ------------------------------------------------------------------
1566 // ciTypeFlow::SuccIter::set_succ
1567 //
1568 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1569 int succ_ct = _pred->successors()->length();
1570 if (_index < succ_ct) {
1571 _pred->successors()->at_put(_index, succ);
1572 } else {
1573 int idx = _index - succ_ct;
1574 _pred->exceptions()->at_put(idx, succ);
1575 }
1576 }
1577
1578 // ciTypeFlow::Block
1579 //
1580 // A basic block.
1581
1582 // ------------------------------------------------------------------
1583 // ciTypeFlow::Block::Block
1584 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1585 ciBlock *ciblk,
1586 ciTypeFlow::JsrSet* jsrs) {
1587 _ciblock = ciblk;
1588 _exceptions = NULL;
1589 _exc_klasses = NULL;
1590 _successors = NULL;
1591 _predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
1592 _state = new (outer->arena()) StateVector(outer);
1593 JsrSet* new_jsrs =
1594 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1595 jsrs->copy_into(new_jsrs);
1596 _jsrs = new_jsrs;
1597 _next = NULL;
1598 _on_work_list = false;
1599 _backedge_copy = false;
1600 _has_monitorenter = false;
1601 _trap_bci = -1;
1602 _trap_index = 0;
1603 df_init();
1604
1605 if (CITraceTypeFlow) {
1606 tty->print_cr(">> Created new block");
1607 print_on(tty);
1608 }
1609
1610 assert(this->outer() == outer, "outer link set up");
1611 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1612 }
1613
1614 // ------------------------------------------------------------------
1615 // ciTypeFlow::Block::df_init
1616 void ciTypeFlow::Block::df_init() {
1617 _pre_order = -1; assert(!has_pre_order(), "");
1618 _post_order = -1; assert(!has_post_order(), "");
1619 _loop = NULL;
1620 _irreducible_entry = false;
1621 _rpo_next = NULL;
1622 }
1623
1624 // ------------------------------------------------------------------
1625 // ciTypeFlow::Block::successors
1626 //
1627 // Get the successors for this Block.
1628 GrowableArray<ciTypeFlow::Block*>*
1629 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1630 ciTypeFlow::StateVector* state,
1631 ciTypeFlow::JsrSet* jsrs) {
1632 if (_successors == NULL) {
1633 if (CITraceTypeFlow) {
1634 tty->print(">> Computing successors for block ");
1635 print_value_on(tty);
1636 tty->cr();
1637 }
1638
1639 ciTypeFlow* analyzer = outer();
1640 Arena* arena = analyzer->arena();
1641 Block* block = NULL;
1642 bool has_successor = !has_trap() &&
1643 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1644 if (!has_successor) {
1645 _successors =
1646 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1647 // No successors
1648 } else if (control() == ciBlock::fall_through_bci) {
1649 assert(str->cur_bci() == limit(), "bad block end");
1650 // This block simply falls through to the next.
1651 _successors =
1652 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1653
1654 Block* block = analyzer->block_at(limit(), _jsrs);
1655 assert(_successors->length() == FALL_THROUGH, "");
1656 _successors->append(block);
1657 } else {
1658 int current_bci = str->cur_bci();
1659 int next_bci = str->next_bci();
1660 int branch_bci = -1;
1661 Block* target = NULL;
1662 assert(str->next_bci() == limit(), "bad block end");
1663 // This block is not a simple fall-though. Interpret
1664 // the current bytecode to find our successors.
1665 switch (str->cur_bc()) {
1666 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1667 case Bytecodes::_iflt: case Bytecodes::_ifge:
1668 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1669 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1670 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1671 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1672 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1673 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1674 // Our successors are the branch target and the next bci.
1675 branch_bci = str->get_dest();
1676 _successors =
1677 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1678 assert(_successors->length() == IF_NOT_TAKEN, "");
1679 _successors->append(analyzer->block_at(next_bci, jsrs));
1680 assert(_successors->length() == IF_TAKEN, "");
1681 _successors->append(analyzer->block_at(branch_bci, jsrs));
1682 break;
1683
1684 case Bytecodes::_goto:
1685 branch_bci = str->get_dest();
1686 _successors =
1687 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1688 assert(_successors->length() == GOTO_TARGET, "");
1689 _successors->append(analyzer->block_at(branch_bci, jsrs));
1690 break;
1691
1692 case Bytecodes::_jsr:
1693 branch_bci = str->get_dest();
1694 _successors =
1695 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1696 assert(_successors->length() == GOTO_TARGET, "");
1697 _successors->append(analyzer->block_at(branch_bci, jsrs));
1698 break;
1699
1700 case Bytecodes::_goto_w:
1701 case Bytecodes::_jsr_w:
1702 _successors =
1703 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1704 assert(_successors->length() == GOTO_TARGET, "");
1705 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1706 break;
1707
1708 case Bytecodes::_tableswitch: {
1709 Bytecode_tableswitch tableswitch(str);
1710
1711 int len = tableswitch.length();
1712 _successors =
1713 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1714 int bci = current_bci + tableswitch.default_offset();
1715 Block* block = analyzer->block_at(bci, jsrs);
1716 assert(_successors->length() == SWITCH_DEFAULT, "");
1717 _successors->append(block);
1718 while (--len >= 0) {
1719 int bci = current_bci + tableswitch.dest_offset_at(len);
1720 block = analyzer->block_at(bci, jsrs);
1721 assert(_successors->length() >= SWITCH_CASES, "");
1722 _successors->append_if_missing(block);
1723 }
1724 break;
1725 }
1726
1727 case Bytecodes::_lookupswitch: {
1728 Bytecode_lookupswitch lookupswitch(str);
1729
1730 int npairs = lookupswitch.number_of_pairs();
1731 _successors =
1732 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1733 int bci = current_bci + lookupswitch.default_offset();
1734 Block* block = analyzer->block_at(bci, jsrs);
1735 assert(_successors->length() == SWITCH_DEFAULT, "");
1736 _successors->append(block);
1737 while(--npairs >= 0) {
1738 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1739 int bci = current_bci + pair.offset();
1740 Block* block = analyzer->block_at(bci, jsrs);
1741 assert(_successors->length() >= SWITCH_CASES, "");
1742 _successors->append_if_missing(block);
1743 }
1744 break;
1745 }
1746
1747 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1748 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1749 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1750 case Bytecodes::_return:
1751 _successors =
1752 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1753 // No successors
1754 break;
1755
1756 case Bytecodes::_ret: {
1757 _successors =
1758 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1759
1760 Cell local = state->local(str->get_index());
1761 ciType* return_address = state->type_at(local);
1762 assert(return_address->is_return_address(), "verify: wrong type");
1763 int bci = return_address->as_return_address()->bci();
1764 assert(_successors->length() == GOTO_TARGET, "");
1765 _successors->append(analyzer->block_at(bci, jsrs));
1766 break;
1767 }
1768
1769 case Bytecodes::_wide:
1770 default:
1771 ShouldNotReachHere();
1772 break;
1773 }
1774 }
1775
1776 // Set predecessor information
1777 for (int i = 0; i < _successors->length(); i++) {
1778 Block* block = _successors->at(i);
1779 block->predecessors()->append(this);
1780 }
1781 }
1782 return _successors;
1783 }
1784
1785 // ------------------------------------------------------------------
1786 // ciTypeFlow::Block:compute_exceptions
1787 //
1788 // Compute the exceptional successors and types for this Block.
1789 void ciTypeFlow::Block::compute_exceptions() {
1790 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1791
1792 if (CITraceTypeFlow) {
1793 tty->print(">> Computing exceptions for block ");
1794 print_value_on(tty);
1795 tty->cr();
1796 }
1797
1798 ciTypeFlow* analyzer = outer();
1799 Arena* arena = analyzer->arena();
1800
1801 // Any bci in the block will do.
1802 ciExceptionHandlerStream str(analyzer->method(), start());
1803
1804 // Allocate our growable arrays.
1805 int exc_count = str.count();
1806 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1807 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1808 0, NULL);
1809
1810 for ( ; !str.is_done(); str.next()) {
1811 ciExceptionHandler* handler = str.handler();
1812 int bci = handler->handler_bci();
1813 ciInstanceKlass* klass = NULL;
1814 if (bci == -1) {
1815 // There is no catch all. It is possible to exit the method.
1816 break;
1817 }
1818 if (handler->is_catch_all()) {
1819 klass = analyzer->env()->Throwable_klass();
1820 } else {
1821 klass = handler->catch_klass();
1822 }
1823 _exceptions->append(analyzer->block_at(bci, _jsrs));
1824 _exc_klasses->append(klass);
1825 }
1826 }
1827
1828 // ------------------------------------------------------------------
1829 // ciTypeFlow::Block::set_backedge_copy
1830 // Use this only to make a pre-existing public block into a backedge copy.
1831 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1832 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1833 _backedge_copy = z;
1834 }
1835
1836 // ------------------------------------------------------------------
1837 // ciTypeFlow::Block::is_clonable_exit
1838 //
1839 // At most 2 normal successors, one of which continues looping,
1840 // and all exceptional successors must exit.
1841 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1842 int normal_cnt = 0;
1843 int in_loop_cnt = 0;
1844 for (SuccIter iter(this); !iter.done(); iter.next()) {
1845 Block* succ = iter.succ();
1846 if (iter.is_normal_ctrl()) {
1847 if (++normal_cnt > 2) return false;
1848 if (lp->contains(succ->loop())) {
1849 if (++in_loop_cnt > 1) return false;
1850 }
1851 } else {
1852 if (lp->contains(succ->loop())) return false;
1853 }
1854 }
1855 return in_loop_cnt == 1;
1856 }
1857
1858 // ------------------------------------------------------------------
1859 // ciTypeFlow::Block::looping_succ
1860 //
1861 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1862 assert(successors()->length() <= 2, "at most 2 normal successors");
1863 for (SuccIter iter(this); !iter.done(); iter.next()) {
1864 Block* succ = iter.succ();
1865 if (lp->contains(succ->loop())) {
1866 return succ;
1867 }
1868 }
1869 return NULL;
1870 }
1871
1872 #ifndef PRODUCT
1873 // ------------------------------------------------------------------
1874 // ciTypeFlow::Block::print_value_on
1875 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1876 if (has_pre_order()) st->print("#%-2d ", pre_order());
1877 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1878 st->print("[%d - %d)", start(), limit());
1879 if (is_loop_head()) st->print(" lphd");
1880 if (is_irreducible_entry()) st->print(" irred");
1881 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1882 if (is_backedge_copy()) st->print("/backedge_copy");
1883 }
1884
1885 // ------------------------------------------------------------------
1886 // ciTypeFlow::Block::print_on
1887 void ciTypeFlow::Block::print_on(outputStream* st) const {
1888 if ((Verbose || WizardMode) && (limit() >= 0)) {
1889 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1890 outer()->method()->print_codes_on(start(), limit(), st);
1891 }
1892 st->print_cr(" ==================================================== ");
1893 st->print (" ");
1894 print_value_on(st);
1895 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1896 if (loop() && loop()->parent() != NULL) {
1897 st->print(" loops:");
1898 Loop* lp = loop();
1899 do {
1900 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1901 if (lp->is_irreducible()) st->print("(ir)");
1902 lp = lp->parent();
1903 } while (lp->parent() != NULL);
1904 }
1905 st->cr();
1906 _state->print_on(st);
1907 if (_successors == NULL) {
1908 st->print_cr(" No successor information");
1909 } else {
1910 int num_successors = _successors->length();
1911 st->print_cr(" Successors : %d", num_successors);
1912 for (int i = 0; i < num_successors; i++) {
1913 Block* successor = _successors->at(i);
1914 st->print(" ");
1915 successor->print_value_on(st);
1916 st->cr();
1917 }
1918 }
1919 if (_predecessors == NULL) {
1920 st->print_cr(" No predecessor information");
1921 } else {
1922 int num_predecessors = _predecessors->length();
1923 st->print_cr(" Predecessors : %d", num_predecessors);
1924 for (int i = 0; i < num_predecessors; i++) {
1925 Block* predecessor = _predecessors->at(i);
1926 st->print(" ");
1927 predecessor->print_value_on(st);
1928 st->cr();
1929 }
1930 }
1931 if (_exceptions == NULL) {
1932 st->print_cr(" No exception information");
1933 } else {
1934 int num_exceptions = _exceptions->length();
1935 st->print_cr(" Exceptions : %d", num_exceptions);
1936 for (int i = 0; i < num_exceptions; i++) {
1937 Block* exc_succ = _exceptions->at(i);
1938 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1939 st->print(" ");
1940 exc_succ->print_value_on(st);
1941 st->print(" -- ");
1942 exc_klass->name()->print_symbol_on(st);
1943 st->cr();
1944 }
1945 }
1946 if (has_trap()) {
1947 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1948 }
1949 st->print_cr(" ==================================================== ");
1950 }
1951 #endif
1952
1953 #ifndef PRODUCT
1954 // ------------------------------------------------------------------
1955 // ciTypeFlow::LocalSet::print_on
1956 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
1957 st->print("{");
1958 for (int i = 0; i < max; i++) {
1959 if (test(i)) st->print(" %d", i);
1960 }
1961 if (limit > max) {
1962 st->print(" %d..%d ", max, limit);
1963 }
1964 st->print(" }");
1965 }
1966 #endif
1967
1968 // ciTypeFlow
1969 //
1970 // This is a pass over the bytecodes which computes the following:
1971 // basic block structure
1972 // interpreter type-states (a la the verifier)
1973
1974 // ------------------------------------------------------------------
1975 // ciTypeFlow::ciTypeFlow
1976 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
1977 _env = env;
1978 _method = method;
1979 _methodBlocks = method->get_method_blocks();
1980 _max_locals = method->max_locals();
1981 _max_stack = method->max_stack();
1982 _code_size = method->code_size();
1983 _has_irreducible_entry = false;
1984 _osr_bci = osr_bci;
1985 _failure_reason = NULL;
1986 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
1987 _work_list = NULL;
1988
1989 _ciblock_count = _methodBlocks->num_blocks();
1990 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
1991 for (int i = 0; i < _ciblock_count; i++) {
1992 _idx_to_blocklist[i] = NULL;
1993 }
1994 _block_map = NULL; // until all blocks are seen
1995 _jsr_count = 0;
1996 _jsr_records = NULL;
1997 }
1998
1999 // ------------------------------------------------------------------
2000 // ciTypeFlow::work_list_next
2001 //
2002 // Get the next basic block from our work list.
2003 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2004 assert(!work_list_empty(), "work list must not be empty");
2005 Block* next_block = _work_list;
2006 _work_list = next_block->next();
2007 next_block->set_next(NULL);
2008 next_block->set_on_work_list(false);
2009 return next_block;
2010 }
2011
2012 // ------------------------------------------------------------------
2013 // ciTypeFlow::add_to_work_list
2014 //
2015 // Add a basic block to our work list.
2016 // List is sorted by decreasing postorder sort (same as increasing RPO)
2017 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2018 assert(!block->is_on_work_list(), "must not already be on work list");
2019
2020 if (CITraceTypeFlow) {
2021 tty->print(">> Adding block ");
2022 block->print_value_on(tty);
2023 tty->print_cr(" to the work list : ");
2024 }
2025
2026 block->set_on_work_list(true);
2027
2028 // decreasing post order sort
2029
2030 Block* prev = NULL;
2031 Block* current = _work_list;
2032 int po = block->post_order();
2033 while (current != NULL) {
2034 if (!current->has_post_order() || po > current->post_order())
2035 break;
2036 prev = current;
2037 current = current->next();
2038 }
2039 if (prev == NULL) {
2040 block->set_next(_work_list);
2041 _work_list = block;
2042 } else {
2043 block->set_next(current);
2044 prev->set_next(block);
2045 }
2046
2047 if (CITraceTypeFlow) {
2048 tty->cr();
2049 }
2050 }
2051
2052 // ------------------------------------------------------------------
2053 // ciTypeFlow::block_at
2054 //
2055 // Return the block beginning at bci which has a JsrSet compatible
2056 // with jsrs.
2057 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2058 // First find the right ciBlock.
2059 if (CITraceTypeFlow) {
2060 tty->print(">> Requesting block for %d/", bci);
2061 jsrs->print_on(tty);
2062 tty->cr();
2063 }
2064
2065 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2066 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2067 Block* block = get_block_for(ciblk->index(), jsrs, option);
2068
2069 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2070
2071 if (CITraceTypeFlow) {
2072 if (block != NULL) {
2073 tty->print(">> Found block ");
2074 block->print_value_on(tty);
2075 tty->cr();
2076 } else {
2077 tty->print_cr(">> No such block.");
2078 }
2079 }
2080
2081 return block;
2082 }
2083
2084 // ------------------------------------------------------------------
2085 // ciTypeFlow::make_jsr_record
2086 //
2087 // Make a JsrRecord for a given (entry, return) pair, if such a record
2088 // does not already exist.
2089 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2090 int return_address) {
2091 if (_jsr_records == NULL) {
2092 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2093 _jsr_count,
2094 0,
2095 NULL);
2096 }
2097 JsrRecord* record = NULL;
2098 int len = _jsr_records->length();
2099 for (int i = 0; i < len; i++) {
2100 JsrRecord* record = _jsr_records->at(i);
2101 if (record->entry_address() == entry_address &&
2102 record->return_address() == return_address) {
2103 return record;
2104 }
2105 }
2106
2107 record = new (arena()) JsrRecord(entry_address, return_address);
2108 _jsr_records->append(record);
2109 return record;
2110 }
2111
2112 // ------------------------------------------------------------------
2113 // ciTypeFlow::flow_exceptions
2114 //
2115 // Merge the current state into all exceptional successors at the
2116 // current point in the code.
2117 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2118 GrowableArray<ciInstanceKlass*>* exc_klasses,
2119 ciTypeFlow::StateVector* state) {
2120 int len = exceptions->length();
2121 assert(exc_klasses->length() == len, "must have same length");
2122 for (int i = 0; i < len; i++) {
2123 Block* block = exceptions->at(i);
2124 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2125
2126 if (!exception_klass->is_loaded()) {
2127 // Do not compile any code for unloaded exception types.
2128 // Following compiler passes are responsible for doing this also.
2129 continue;
2130 }
2131
2132 if (block->meet_exception(exception_klass, state)) {
2133 // Block was modified and has PO. Add it to the work list.
2134 if (block->has_post_order() &&
2135 !block->is_on_work_list()) {
2136 add_to_work_list(block);
2137 }
2138 }
2139 }
2140 }
2141
2142 // ------------------------------------------------------------------
2143 // ciTypeFlow::flow_successors
2144 //
2145 // Merge the current state into all successors at the current point
2146 // in the code.
2147 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2148 ciTypeFlow::StateVector* state) {
2149 int len = successors->length();
2150 for (int i = 0; i < len; i++) {
2151 Block* block = successors->at(i);
2152 if (block->meet(state)) {
2153 // Block was modified and has PO. Add it to the work list.
2154 if (block->has_post_order() &&
2155 !block->is_on_work_list()) {
2156 add_to_work_list(block);
2157 }
2158 }
2159 }
2160 }
2161
2162 // ------------------------------------------------------------------
2163 // ciTypeFlow::can_trap
2164 //
2165 // Tells if a given instruction is able to generate an exception edge.
2166 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2167 // Cf. GenerateOopMap::do_exception_edge.
2168 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2169
2170 switch (str.cur_bc()) {
2171 // %%% FIXME: ldc of Class can generate an exception
2172 case Bytecodes::_ldc:
2173 case Bytecodes::_ldc_w:
2174 case Bytecodes::_ldc2_w:
2175 case Bytecodes::_aload_0:
2176 // These bytecodes can trap for rewriting. We need to assume that
2177 // they do not throw exceptions to make the monitor analysis work.
2178 return false;
2179
2180 case Bytecodes::_ireturn:
2181 case Bytecodes::_lreturn:
2182 case Bytecodes::_freturn:
2183 case Bytecodes::_dreturn:
2184 case Bytecodes::_areturn:
2185 case Bytecodes::_return:
2186 // We can assume the monitor stack is empty in this analysis.
2187 return false;
2188
2189 case Bytecodes::_monitorexit:
2190 // We can assume monitors are matched in this analysis.
2191 return false;
2192 }
2193
2194 return true;
2195 }
2196
2197 // ------------------------------------------------------------------
2198 // ciTypeFlow::clone_loop_heads
2199 //
2200 // Clone the loop heads
2201 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2202 bool rslt = false;
2203 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2204 lp = iter.current();
2205 Block* head = lp->head();
2206 if (lp == loop_tree_root() ||
2207 lp->is_irreducible() ||
2208 !head->is_clonable_exit(lp))
2209 continue;
2210
2211 // Avoid BoxLock merge.
2212 if (EliminateNestedLocks && head->has_monitorenter())
2213 continue;
2214
2215 // check not already cloned
2216 if (head->backedge_copy_count() != 0)
2217 continue;
2218
2219 // Don't clone head of OSR loop to get correct types in start block.
2220 if (is_osr_flow() && head->start() == start_bci())
2221 continue;
2222
2223 // check _no_ shared head below us
2224 Loop* ch;
2225 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2226 if (ch != NULL)
2227 continue;
2228
2229 // Clone head
2230 Block* new_head = head->looping_succ(lp);
2231 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2232 // Update lp's info
2233 clone->set_loop(lp);
2234 lp->set_head(new_head);
2235 lp->set_tail(clone);
2236 // And move original head into outer loop
2237 head->set_loop(lp->parent());
2238
2239 rslt = true;
2240 }
2241 return rslt;
2242 }
2243
2244 // ------------------------------------------------------------------
2245 // ciTypeFlow::clone_loop_head
2246 //
2247 // Clone lp's head and replace tail's successors with clone.
2248 //
2249 // |
2250 // v
2251 // head <-> body
2252 // |
2253 // v
2254 // exit
2255 //
2256 // new_head
2257 //
2258 // |
2259 // v
2260 // head ----------\
2261 // | |
2262 // | v
2263 // | clone <-> body
2264 // | |
2265 // | /--/
2266 // | |
2267 // v v
2268 // exit
2269 //
2270 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2271 Block* head = lp->head();
2272 Block* tail = lp->tail();
2273 if (CITraceTypeFlow) {
2274 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2275 tty->print(" for predecessor "); tail->print_value_on(tty);
2276 tty->cr();
2277 }
2278 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2279 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2280
2281 assert(!clone->has_pre_order(), "just created");
2282 clone->set_next_pre_order();
2283
2284 // Insert clone after (orig) tail in reverse post order
2285 clone->set_rpo_next(tail->rpo_next());
2286 tail->set_rpo_next(clone);
2287
2288 // tail->head becomes tail->clone
2289 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2290 if (iter.succ() == head) {
2291 iter.set_succ(clone);
2292 }
2293 }
2294 flow_block(tail, temp_vector, temp_set);
2295 if (head == tail) {
2296 // For self-loops, clone->head becomes clone->clone
2297 flow_block(clone, temp_vector, temp_set);
2298 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2299 if (iter.succ() == head) {
2300 iter.set_succ(clone);
2301 break;
2302 }
2303 }
2304 }
2305 flow_block(clone, temp_vector, temp_set);
2306
2307 return clone;
2308 }
2309
2310 // ------------------------------------------------------------------
2311 // ciTypeFlow::flow_block
2312 //
2313 // Interpret the effects of the bytecodes on the incoming state
2314 // vector of a basic block. Push the changed state to succeeding
2315 // basic blocks.
2316 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2317 ciTypeFlow::StateVector* state,
2318 ciTypeFlow::JsrSet* jsrs) {
2319 if (CITraceTypeFlow) {
2320 tty->print("\n>> ANALYZING BLOCK : ");
2321 tty->cr();
2322 block->print_on(tty);
2323 }
2324 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2325
2326 int start = block->start();
2327 int limit = block->limit();
2328 int control = block->control();
2329 if (control != ciBlock::fall_through_bci) {
2330 limit = control;
2331 }
2332
2333 // Grab the state from the current block.
2334 block->copy_state_into(state);
2335 state->def_locals()->clear();
2336
2337 GrowableArray<Block*>* exceptions = block->exceptions();
2338 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2339 bool has_exceptions = exceptions->length() > 0;
2340
2341 bool exceptions_used = false;
2342
2343 ciBytecodeStream str(method());
2344 str.reset_to_bci(start);
2345 Bytecodes::Code code;
2346 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2347 str.cur_bci() < limit) {
2348 // Check for exceptional control flow from this point.
2349 if (has_exceptions && can_trap(str)) {
2350 flow_exceptions(exceptions, exc_klasses, state);
2351 exceptions_used = true;
2352 }
2353 // Apply the effects of the current bytecode to our state.
2354 bool res = state->apply_one_bytecode(&str);
2355
2356 // Watch for bailouts.
2357 if (failing()) return;
2358
2359 if (str.cur_bc() == Bytecodes::_monitorenter) {
2360 block->set_has_monitorenter();
2361 }
2362
2363 if (res) {
2364
2365 // We have encountered a trap. Record it in this block.
2366 block->set_trap(state->trap_bci(), state->trap_index());
2367
2368 if (CITraceTypeFlow) {
2369 tty->print_cr(">> Found trap");
2370 block->print_on(tty);
2371 }
2372
2373 // Save set of locals defined in this block
2374 block->def_locals()->add(state->def_locals());
2375
2376 // Record (no) successors.
2377 block->successors(&str, state, jsrs);
2378
2379 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2380
2381 // Discontinue interpretation of this Block.
2382 return;
2383 }
2384 }
2385
2386 GrowableArray<Block*>* successors = NULL;
2387 if (control != ciBlock::fall_through_bci) {
2388 // Check for exceptional control flow from this point.
2389 if (has_exceptions && can_trap(str)) {
2390 flow_exceptions(exceptions, exc_klasses, state);
2391 exceptions_used = true;
2392 }
2393
2394 // Fix the JsrSet to reflect effect of the bytecode.
2395 block->copy_jsrs_into(jsrs);
2396 jsrs->apply_control(this, &str, state);
2397
2398 // Find successor edges based on old state and new JsrSet.
2399 successors = block->successors(&str, state, jsrs);
2400
2401 // Apply the control changes to the state.
2402 state->apply_one_bytecode(&str);
2403 } else {
2404 // Fall through control
2405 successors = block->successors(&str, NULL, NULL);
2406 }
2407
2408 // Save set of locals defined in this block
2409 block->def_locals()->add(state->def_locals());
2410
2411 // Remove untaken exception paths
2412 if (!exceptions_used)
2413 exceptions->clear();
2414
2415 // Pass our state to successors.
2416 flow_successors(successors, state);
2417 }
2418
2419 // ------------------------------------------------------------------
2420 // ciTypeFlow::PostOrderLoops::next
2421 //
2422 // Advance to next loop tree using a postorder, left-to-right traversal.
2423 void ciTypeFlow::PostorderLoops::next() {
2424 assert(!done(), "must not be done.");
2425 if (_current->sibling() != NULL) {
2426 _current = _current->sibling();
2427 while (_current->child() != NULL) {
2428 _current = _current->child();
2429 }
2430 } else {
2431 _current = _current->parent();
2432 }
2433 }
2434
2435 // ------------------------------------------------------------------
2436 // ciTypeFlow::PreOrderLoops::next
2437 //
2438 // Advance to next loop tree using a preorder, left-to-right traversal.
2439 void ciTypeFlow::PreorderLoops::next() {
2440 assert(!done(), "must not be done.");
2441 if (_current->child() != NULL) {
2442 _current = _current->child();
2443 } else if (_current->sibling() != NULL) {
2444 _current = _current->sibling();
2445 } else {
2446 while (_current != _root && _current->sibling() == NULL) {
2447 _current = _current->parent();
2448 }
2449 if (_current == _root) {
2450 _current = NULL;
2451 assert(done(), "must be done.");
2452 } else {
2453 assert(_current->sibling() != NULL, "must be more to do");
2454 _current = _current->sibling();
2455 }
2456 }
2457 }
2458
2459 // ------------------------------------------------------------------
2460 // ciTypeFlow::Loop::sorted_merge
2461 //
2462 // Merge the branch lp into this branch, sorting on the loop head
2463 // pre_orders. Returns the leaf of the merged branch.
2464 // Child and sibling pointers will be setup later.
2465 // Sort is (looking from leaf towards the root)
2466 // descending on primary key: loop head's pre_order, and
2467 // ascending on secondary key: loop tail's pre_order.
2468 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2469 Loop* leaf = this;
2470 Loop* prev = NULL;
2471 Loop* current = leaf;
2472 while (lp != NULL) {
2473 int lp_pre_order = lp->head()->pre_order();
2474 // Find insertion point for "lp"
2475 while (current != NULL) {
2476 if (current == lp)
2477 return leaf; // Already in list
2478 if (current->head()->pre_order() < lp_pre_order)
2479 break;
2480 if (current->head()->pre_order() == lp_pre_order &&
2481 current->tail()->pre_order() > lp->tail()->pre_order()) {
2482 break;
2483 }
2484 prev = current;
2485 current = current->parent();
2486 }
2487 Loop* next_lp = lp->parent(); // Save future list of items to insert
2488 // Insert lp before current
2489 lp->set_parent(current);
2490 if (prev != NULL) {
2491 prev->set_parent(lp);
2492 } else {
2493 leaf = lp;
2494 }
2495 prev = lp; // Inserted item is new prev[ious]
2496 lp = next_lp; // Next item to insert
2497 }
2498 return leaf;
2499 }
2500
2501 // ------------------------------------------------------------------
2502 // ciTypeFlow::build_loop_tree
2503 //
2504 // Incrementally build loop tree.
2505 void ciTypeFlow::build_loop_tree(Block* blk) {
2506 assert(!blk->is_post_visited(), "precondition");
2507 Loop* innermost = NULL; // merge of loop tree branches over all successors
2508
2509 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2510 Loop* lp = NULL;
2511 Block* succ = iter.succ();
2512 if (!succ->is_post_visited()) {
2513 // Found backedge since predecessor post visited, but successor is not
2514 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2515
2516 // Create a LoopNode to mark this loop.
2517 lp = new (arena()) Loop(succ, blk);
2518 if (succ->loop() == NULL)
2519 succ->set_loop(lp);
2520 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2521
2522 } else { // Nested loop
2523 lp = succ->loop();
2524
2525 // If succ is loop head, find outer loop.
2526 while (lp != NULL && lp->head() == succ) {
2527 lp = lp->parent();
2528 }
2529 if (lp == NULL) {
2530 // Infinite loop, it's parent is the root
2531 lp = loop_tree_root();
2532 }
2533 }
2534
2535 // Check for irreducible loop.
2536 // Successor has already been visited. If the successor's loop head
2537 // has already been post-visited, then this is another entry into the loop.
2538 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2539 _has_irreducible_entry = true;
2540 lp->set_irreducible(succ);
2541 if (!succ->is_on_work_list()) {
2542 // Assume irreducible entries need more data flow
2543 add_to_work_list(succ);
2544 }
2545 Loop* plp = lp->parent();
2546 if (plp == NULL) {
2547 // This only happens for some irreducible cases. The parent
2548 // will be updated during a later pass.
2549 break;
2550 }
2551 lp = plp;
2552 }
2553
2554 // Merge loop tree branch for all successors.
2555 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2556
2557 } // end loop
2558
2559 if (innermost == NULL) {
2560 assert(blk->successors()->length() == 0, "CFG exit");
2561 blk->set_loop(loop_tree_root());
2562 } else if (innermost->head() == blk) {
2563 // If loop header, complete the tree pointers
2564 if (blk->loop() != innermost) {
2565 #ifdef ASSERT
2566 assert(blk->loop()->head() == innermost->head(), "same head");
2567 Loop* dl;
2568 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2569 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2570 #endif
2571 blk->set_loop(innermost);
2572 }
2573 innermost->def_locals()->add(blk->def_locals());
2574 Loop* l = innermost;
2575 Loop* p = l->parent();
2576 while (p && l->head() == blk) {
2577 l->set_sibling(p->child()); // Put self on parents 'next child'
2578 p->set_child(l); // Make self the first child of parent
2579 p->def_locals()->add(l->def_locals());
2580 l = p; // Walk up the parent chain
2581 p = l->parent();
2582 }
2583 } else {
2584 blk->set_loop(innermost);
2585 innermost->def_locals()->add(blk->def_locals());
2586 }
2587 }
2588
2589 // ------------------------------------------------------------------
2590 // ciTypeFlow::Loop::contains
2591 //
2592 // Returns true if lp is nested loop.
2593 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2594 assert(lp != NULL, "");
2595 if (this == lp || head() == lp->head()) return true;
2596 int depth1 = depth();
2597 int depth2 = lp->depth();
2598 if (depth1 > depth2)
2599 return false;
2600 while (depth1 < depth2) {
2601 depth2--;
2602 lp = lp->parent();
2603 }
2604 return this == lp;
2605 }
2606
2607 // ------------------------------------------------------------------
2608 // ciTypeFlow::Loop::depth
2609 //
2610 // Loop depth
2611 int ciTypeFlow::Loop::depth() const {
2612 int dp = 0;
2613 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2614 dp++;
2615 return dp;
2616 }
2617
2618 #ifndef PRODUCT
2619 // ------------------------------------------------------------------
2620 // ciTypeFlow::Loop::print
2621 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2622 for (int i = 0; i < indent; i++) st->print(" ");
2623 st->print("%d<-%d %s",
2624 is_root() ? 0 : this->head()->pre_order(),
2625 is_root() ? 0 : this->tail()->pre_order(),
2626 is_irreducible()?" irr":"");
2627 st->print(" defs: ");
2628 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2629 st->cr();
2630 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2631 ch->print(st, indent+2);
2632 }
2633 #endif
2634
2635 // ------------------------------------------------------------------
2636 // ciTypeFlow::df_flow_types
2637 //
2638 // Perform the depth first type flow analysis. Helper for flow_types.
2639 void ciTypeFlow::df_flow_types(Block* start,
2640 bool do_flow,
2641 StateVector* temp_vector,
2642 JsrSet* temp_set) {
2643 int dft_len = 100;
2644 GrowableArray<Block*> stk(dft_len);
2645
2646 ciBlock* dummy = _methodBlocks->make_dummy_block();
2647 JsrSet* root_set = new JsrSet(NULL, 0);
2648 Block* root_head = new (arena()) Block(this, dummy, root_set);
2649 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2650 root_head->set_pre_order(0);
2651 root_head->set_post_order(0);
2652 root_tail->set_pre_order(max_jint);
2653 root_tail->set_post_order(max_jint);
2654 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2655
2656 stk.push(start);
2657
2658 _next_pre_order = 0; // initialize pre_order counter
2659 _rpo_list = NULL;
2660 int next_po = 0; // initialize post_order counter
2661
2662 // Compute RPO and the control flow graph
2663 int size;
2664 while ((size = stk.length()) > 0) {
2665 Block* blk = stk.top(); // Leave node on stack
2666 if (!blk->is_visited()) {
2667 // forward arc in graph
2668 assert (!blk->has_pre_order(), "");
2669 blk->set_next_pre_order();
2670
2671 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2672 // Too many basic blocks. Bail out.
2673 // This can happen when try/finally constructs are nested to depth N,
2674 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2675 // "MaxNodeLimit / 2" is used because probably the parser will
2676 // generate at least twice that many nodes and bail out.
2677 record_failure("too many basic blocks");
2678 return;
2679 }
2680 if (do_flow) {
2681 flow_block(blk, temp_vector, temp_set);
2682 if (failing()) return; // Watch for bailouts.
2683 }
2684 } else if (!blk->is_post_visited()) {
2685 // cross or back arc
2686 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2687 Block* succ = iter.succ();
2688 if (!succ->is_visited()) {
2689 stk.push(succ);
2690 }
2691 }
2692 if (stk.length() == size) {
2693 // There were no additional children, post visit node now
2694 stk.pop(); // Remove node from stack
2695
2696 build_loop_tree(blk);
2697 blk->set_post_order(next_po++); // Assign post order
2698 prepend_to_rpo_list(blk);
2699 assert(blk->is_post_visited(), "");
2700
2701 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2702 // Assume loop heads need more data flow
2703 add_to_work_list(blk);
2704 }
2705 }
2706 } else {
2707 stk.pop(); // Remove post-visited node from stack
2708 }
2709 }
2710 }
2711
2712 // ------------------------------------------------------------------
2713 // ciTypeFlow::flow_types
2714 //
2715 // Perform the type flow analysis, creating and cloning Blocks as
2716 // necessary.
2717 void ciTypeFlow::flow_types() {
2718 ResourceMark rm;
2719 StateVector* temp_vector = new StateVector(this);
2720 JsrSet* temp_set = new JsrSet(NULL, 16);
2721
2722 // Create the method entry block.
2723 Block* start = block_at(start_bci(), temp_set);
2724
2725 // Load the initial state into it.
2726 const StateVector* start_state = get_start_state();
2727 if (failing()) return;
2728 start->meet(start_state);
2729
2730 // Depth first visit
2731 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2732
2733 if (failing()) return;
2734 assert(_rpo_list == start, "must be start");
2735
2736 // Any loops found?
2737 if (loop_tree_root()->child() != NULL &&
2738 env()->comp_level() >= CompLevel_full_optimization) {
2739 // Loop optimizations are not performed on Tier1 compiles.
2740
2741 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2742
2743 // If some loop heads were cloned, recompute postorder and loop tree
2744 if (changed) {
2745 loop_tree_root()->set_child(NULL);
2746 for (Block* blk = _rpo_list; blk != NULL;) {
2747 Block* next = blk->rpo_next();
2748 blk->df_init();
2749 blk = next;
2750 }
2751 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2752 }
2753 }
2754
2755 if (CITraceTypeFlow) {
2756 tty->print_cr("\nLoop tree");
2757 loop_tree_root()->print();
2758 }
2759
2760 // Continue flow analysis until fixed point reached
2761
2762 debug_only(int max_block = _next_pre_order;)
2763
2764 while (!work_list_empty()) {
2765 Block* blk = work_list_next();
2766 assert (blk->has_post_order(), "post order assigned above");
2767
2768 flow_block(blk, temp_vector, temp_set);
2769
2770 assert (max_block == _next_pre_order, "no new blocks");
2771 assert (!failing(), "no more bailouts");
2772 }
2773 }
2774
2775 // ------------------------------------------------------------------
2776 // ciTypeFlow::map_blocks
2777 //
2778 // Create the block map, which indexes blocks in reverse post-order.
2779 void ciTypeFlow::map_blocks() {
2780 assert(_block_map == NULL, "single initialization");
2781 int block_ct = _next_pre_order;
2782 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2783 assert(block_ct == block_count(), "");
2784
2785 Block* blk = _rpo_list;
2786 for (int m = 0; m < block_ct; m++) {
2787 int rpo = blk->rpo();
2788 assert(rpo == m, "should be sequential");
2789 _block_map[rpo] = blk;
2790 blk = blk->rpo_next();
2791 }
2792 assert(blk == NULL, "should be done");
2793
2794 for (int j = 0; j < block_ct; j++) {
2795 assert(_block_map[j] != NULL, "must not drop any blocks");
2796 Block* block = _block_map[j];
2797 // Remove dead blocks from successor lists:
2798 for (int e = 0; e <= 1; e++) {
2799 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2800 for (int k = 0; k < l->length(); k++) {
2801 Block* s = l->at(k);
2802 if (!s->has_post_order()) {
2803 if (CITraceTypeFlow) {
2804 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2805 s->print_value_on(tty);
2806 tty->cr();
2807 }
2808 l->remove(s);
2809 --k;
2810 }
2811 }
2812 }
2813 }
2814 }
2815
2816 // ------------------------------------------------------------------
2817 // ciTypeFlow::get_block_for
2818 //
2819 // Find a block with this ciBlock which has a compatible JsrSet.
2820 // If no such block exists, create it, unless the option is no_create.
2821 // If the option is create_backedge_copy, always create a fresh backedge copy.
2822 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2823 Arena* a = arena();
2824 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2825 if (blocks == NULL) {
2826 // Query only?
2827 if (option == no_create) return NULL;
2828
2829 // Allocate the growable array.
2830 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2831 _idx_to_blocklist[ciBlockIndex] = blocks;
2832 }
2833
2834 if (option != create_backedge_copy) {
2835 int len = blocks->length();
2836 for (int i = 0; i < len; i++) {
2837 Block* block = blocks->at(i);
2838 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2839 return block;
2840 }
2841 }
2842 }
2843
2844 // Query only?
2845 if (option == no_create) return NULL;
2846
2847 // We did not find a compatible block. Create one.
2848 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2849 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2850 blocks->append(new_block);
2851 return new_block;
2852 }
2853
2854 // ------------------------------------------------------------------
2855 // ciTypeFlow::backedge_copy_count
2856 //
2857 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2858 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2859
2860 if (blocks == NULL) {
2861 return 0;
2862 }
2863
2864 int count = 0;
2865 int len = blocks->length();
2866 for (int i = 0; i < len; i++) {
2867 Block* block = blocks->at(i);
2868 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2869 count++;
2870 }
2871 }
2872
2873 return count;
2874 }
2875
2876 // ------------------------------------------------------------------
2877 // ciTypeFlow::do_flow
2878 //
2879 // Perform type inference flow analysis.
2880 void ciTypeFlow::do_flow() {
2881 if (CITraceTypeFlow) {
2882 tty->print_cr("\nPerforming flow analysis on method");
2883 method()->print();
2884 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2885 tty->cr();
2886 method()->print_codes();
2887 }
2888 if (CITraceTypeFlow) {
2889 tty->print_cr("Initial CI Blocks");
2890 print_on(tty);
2891 }
2892 flow_types();
2893 // Watch for bailouts.
2894 if (failing()) {
2895 return;
2896 }
2897
2898 map_blocks();
2899
2900 if (CIPrintTypeFlow || CITraceTypeFlow) {
2901 rpo_print_on(tty);
2902 }
2903 }
2904
2905 // ------------------------------------------------------------------
2906 // ciTypeFlow::is_dominated_by
2907 //
2908 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
2909 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
2910 ResourceMark rm;
2911 JsrSet* jsrs = new ciTypeFlow::JsrSet(NULL);
2912 int index = _methodBlocks->block_containing(bci)->index();
2913 int dom_index = _methodBlocks->block_containing(dom_bci)->index();
2914 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
2915 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
2916
2917 // Start block dominates all other blocks
2918 if (start_block()->rpo() == dom_block->rpo()) {
2919 return true;
2920 }
2921
2922 // Dominated[i] is true if block i is dominated by dom_block
2923 int num_blocks = _methodBlocks->num_blocks();
2924 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
2925 for (int i = 0; i < num_blocks; ++i) {
2926 dominated[i] = true;
2927 }
2928 dominated[start_block()->rpo()] = false;
2929
2930 // Iterative dominator algorithm
2931 bool changed = true;
2932 while (changed) {
2933 changed = false;
2934 // Use reverse postorder iteration
2935 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
2936 if (blk->is_start()) {
2937 // Ignore start block
2938 continue;
2939 }
2940 // The block is dominated if it is the dominating block
2941 // itself or if all predecessors are dominated.
2942 int index = blk->rpo();
2943 bool dom = (index == dom_block->rpo());
2944 if (!dom) {
2945 // Check if all predecessors are dominated
2946 dom = true;
2947 for (int i = 0; i < blk->predecessors()->length(); ++i) {
2948 Block* pred = blk->predecessors()->at(i);
2949 if (!dominated[pred->rpo()]) {
2950 dom = false;
2951 break;
2952 }
2953 }
2954 }
2955 // Update dominator information
2956 if (dominated[index] != dom) {
2957 changed = true;
2958 dominated[index] = dom;
2959 }
2960 }
2961 }
2962 // block dominated by dom_block?
2963 return dominated[block->rpo()];
2964 }
2965
2966 // ------------------------------------------------------------------
2967 // ciTypeFlow::record_failure()
2968 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
2969 // This is required because there is not a 1-1 relation between the ciEnv and
2970 // the TypeFlow passes within a compilation task. For example, if the compiler
2971 // is considering inlining a method, it will request a TypeFlow. If that fails,
2972 // the compilation as a whole may continue without the inlining. Some TypeFlow
2973 // requests are not optional; if they fail the requestor is responsible for
2974 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
2975 void ciTypeFlow::record_failure(const char* reason) {
2976 if (env()->log() != NULL) {
2977 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
2978 }
2979 if (_failure_reason == NULL) {
2980 // Record the first failure reason.
2981 _failure_reason = reason;
2982 }
2983 }
2984
2985 #ifndef PRODUCT
2986 // ------------------------------------------------------------------
2987 // ciTypeFlow::print_on
2988 void ciTypeFlow::print_on(outputStream* st) const {
2989 // Walk through CI blocks
2990 st->print_cr("********************************************************");
2991 st->print ("TypeFlow for ");
2992 method()->name()->print_symbol_on(st);
2993 int limit_bci = code_size();
2994 st->print_cr(" %d bytes", limit_bci);
2995 ciMethodBlocks *mblks = _methodBlocks;
2996 ciBlock* current = NULL;
2997 for (int bci = 0; bci < limit_bci; bci++) {
2998 ciBlock* blk = mblks->block_containing(bci);
2999 if (blk != NULL && blk != current) {
3000 current = blk;
3001 current->print_on(st);
3002
3003 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3004 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
3005
3006 if (num_blocks == 0) {
3007 st->print_cr(" No Blocks");
3008 } else {
3009 for (int i = 0; i < num_blocks; i++) {
3010 Block* block = blocks->at(i);
3011 block->print_on(st);
3012 }
3013 }
3014 st->print_cr("--------------------------------------------------------");
3015 st->cr();
3016 }
3017 }
3018 st->print_cr("********************************************************");
3019 st->cr();
3020 }
3021
3022 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3023 st->print_cr("********************************************************");
3024 st->print ("TypeFlow for ");
3025 method()->name()->print_symbol_on(st);
3026 int limit_bci = code_size();
3027 st->print_cr(" %d bytes", limit_bci);
3028 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3029 blk->print_on(st);
3030 st->print_cr("--------------------------------------------------------");
3031 st->cr();
3032 }
3033 st->print_cr("********************************************************");
3034 st->cr();
3035 }
3036 #endif