1 /*
2 * Copyright (c) 2000, 2017, 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 "ci/ciValueKlass.hpp"
35 #include "compiler/compileLog.hpp"
36 #include "interpreter/bytecode.hpp"
37 #include "interpreter/bytecodes.hpp"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "opto/compile.hpp"
42 #include "opto/node.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "utilities/growableArray.hpp"
45
46 // ciTypeFlow::JsrSet
47 //
48 // A JsrSet represents some set of JsrRecords. This class
49 // is used to record a set of all jsr routines which we permit
50 // execution to return (ret) from.
51 //
52 // During abstract interpretation, JsrSets are used to determine
53 // whether two paths which reach a given block are unique, and
54 // should be cloned apart, or are compatible, and should merge
55 // together.
56
57 // ------------------------------------------------------------------
58 // ciTypeFlow::JsrSet::JsrSet
59 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
60 if (arena != NULL) {
61 // Allocate growable array in Arena.
62 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
63 } else {
64 // Allocate growable array in current ResourceArea.
65 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
66 }
67 }
68
69 // ------------------------------------------------------------------
70 // ciTypeFlow::JsrSet::copy_into
71 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
72 int len = size();
73 jsrs->_set->clear();
74 for (int i = 0; i < len; i++) {
75 jsrs->_set->append(_set->at(i));
76 }
77 }
78
79 // ------------------------------------------------------------------
80 // ciTypeFlow::JsrSet::is_compatible_with
81 //
82 // !!!! MISGIVINGS ABOUT THIS... disregard
83 //
84 // Is this JsrSet compatible with some other JsrSet?
85 //
86 // In set-theoretic terms, a JsrSet can be viewed as a partial function
87 // from entry addresses to return addresses. Two JsrSets A and B are
88 // compatible iff
89 //
90 // For any x,
91 // A(x) defined and B(x) defined implies A(x) == B(x)
92 //
93 // Less formally, two JsrSets are compatible when they have identical
94 // return addresses for any entry addresses they share in common.
95 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
96 // Walk through both sets in parallel. If the same entry address
97 // appears in both sets, then the return address must match for
98 // the sets to be compatible.
99 int size1 = size();
100 int size2 = other->size();
101
102 // Special case. If nothing is on the jsr stack, then there can
103 // be no ret.
104 if (size2 == 0) {
105 return true;
106 } else if (size1 != size2) {
107 return false;
108 } else {
109 for (int i = 0; i < size1; i++) {
110 JsrRecord* record1 = record_at(i);
111 JsrRecord* record2 = other->record_at(i);
112 if (record1->entry_address() != record2->entry_address() ||
113 record1->return_address() != record2->return_address()) {
114 return false;
115 }
116 }
117 return true;
118 }
119
120 #if 0
121 int pos1 = 0;
122 int pos2 = 0;
123 int size1 = size();
124 int size2 = other->size();
125 while (pos1 < size1 && pos2 < size2) {
126 JsrRecord* record1 = record_at(pos1);
127 JsrRecord* record2 = other->record_at(pos2);
128 int entry1 = record1->entry_address();
129 int entry2 = record2->entry_address();
130 if (entry1 < entry2) {
131 pos1++;
132 } else if (entry1 > entry2) {
133 pos2++;
134 } else {
135 if (record1->return_address() == record2->return_address()) {
136 pos1++;
137 pos2++;
138 } else {
139 // These two JsrSets are incompatible.
140 return false;
141 }
142 }
143 }
144 // The two JsrSets agree.
145 return true;
146 #endif
147 }
148
149 // ------------------------------------------------------------------
150 // ciTypeFlow::JsrSet::insert_jsr_record
151 //
152 // Insert the given JsrRecord into the JsrSet, maintaining the order
153 // of the set and replacing any element with the same entry address.
154 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
155 int len = size();
156 int entry = record->entry_address();
157 int pos = 0;
158 for ( ; pos < len; pos++) {
159 JsrRecord* current = record_at(pos);
160 if (entry == current->entry_address()) {
161 // Stomp over this entry.
162 _set->at_put(pos, record);
163 assert(size() == len, "must be same size");
164 return;
165 } else if (entry < current->entry_address()) {
166 break;
167 }
168 }
169
170 // Insert the record into the list.
171 JsrRecord* swap = record;
172 JsrRecord* temp = NULL;
173 for ( ; pos < len; pos++) {
174 temp = _set->at(pos);
175 _set->at_put(pos, swap);
176 swap = temp;
177 }
178 _set->append(swap);
179 assert(size() == len+1, "must be larger");
180 }
181
182 // ------------------------------------------------------------------
183 // ciTypeFlow::JsrSet::remove_jsr_record
184 //
185 // Remove the JsrRecord with the given return address from the JsrSet.
186 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
187 int len = size();
188 for (int i = 0; i < len; i++) {
189 if (record_at(i)->return_address() == return_address) {
190 // We have found the proper entry. Remove it from the
191 // JsrSet and exit.
192 for (int j = i+1; j < len ; j++) {
193 _set->at_put(j-1, _set->at(j));
194 }
195 _set->trunc_to(len-1);
196 assert(size() == len-1, "must be smaller");
197 return;
198 }
199 }
200 assert(false, "verify: returning from invalid subroutine");
201 }
202
203 // ------------------------------------------------------------------
204 // ciTypeFlow::JsrSet::apply_control
205 //
206 // Apply the effect of a control-flow bytecode on the JsrSet. The
207 // only bytecodes that modify the JsrSet are jsr and ret.
208 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
209 ciBytecodeStream* str,
210 ciTypeFlow::StateVector* state) {
211 Bytecodes::Code code = str->cur_bc();
212 if (code == Bytecodes::_jsr) {
213 JsrRecord* record =
214 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
215 insert_jsr_record(record);
216 } else if (code == Bytecodes::_jsr_w) {
217 JsrRecord* record =
218 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
219 insert_jsr_record(record);
220 } else if (code == Bytecodes::_ret) {
221 Cell local = state->local(str->get_index());
222 ciType* return_address = state->type_at(local);
223 assert(return_address->is_return_address(), "verify: wrong type");
224 if (size() == 0) {
225 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
226 // This can happen when a loop is inside a finally clause (4614060).
227 analyzer->record_failure("OSR in finally clause");
228 return;
229 }
230 remove_jsr_record(return_address->as_return_address()->bci());
231 }
232 }
233
234 #ifndef PRODUCT
235 // ------------------------------------------------------------------
236 // ciTypeFlow::JsrSet::print_on
237 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
238 st->print("{ ");
239 int num_elements = size();
240 if (num_elements > 0) {
241 int i = 0;
242 for( ; i < num_elements - 1; i++) {
243 _set->at(i)->print_on(st);
244 st->print(", ");
245 }
246 _set->at(i)->print_on(st);
247 st->print(" ");
248 }
249 st->print("}");
250 }
251 #endif
252
253 // ciTypeFlow::StateVector
254 //
255 // A StateVector summarizes the type information at some point in
256 // the program.
257
258 // ------------------------------------------------------------------
259 // ciTypeFlow::StateVector::type_meet
260 //
261 // Meet two types.
262 //
263 // The semi-lattice of types use by this analysis are modeled on those
264 // of the verifier. The lattice is as follows:
265 //
266 // top_type() >= all non-extremal types >= bottom_type
267 // and
268 // Every primitive type is comparable only with itself. The meet of
269 // reference types is determined by their kind: instance class,
270 // interface, or array class. The meet of two types of the same
271 // kind is their least common ancestor. The meet of two types of
272 // different kinds is always java.lang.Object.
273 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
274 assert(t1 != t2, "checked in caller");
275 if (t1->equals(top_type())) {
276 return t2;
277 } else if (t2->equals(top_type())) {
278 return t1;
279 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
280 // Special case null_type. null_type meet any reference type T
281 // is T. null_type meet null_type is null_type.
282 if (t1->equals(null_type())) {
283 if (!t2->is_primitive_type() || t2->equals(null_type())) {
284 return t2;
285 }
286 } else if (t2->equals(null_type())) {
287 if (!t1->is_primitive_type()) {
288 return t1;
289 }
290 }
291
292 // At least one of the two types is a non-top primitive type.
293 // The other type is not equal to it. Fall to bottom.
294 return bottom_type();
295 } else {
296 // Both types are non-top non-primitive types. That is,
297 // both types are either instanceKlasses or arrayKlasses.
298 ciKlass* object_klass = analyzer->env()->Object_klass();
299 ciKlass* k1 = t1->as_klass();
300 ciKlass* k2 = t2->as_klass();
301 if (k1->equals(object_klass) || k2->equals(object_klass)) {
302 return object_klass;
303 } else if (!k1->is_loaded() || !k2->is_loaded()) {
304 // Unloaded classes fall to java.lang.Object at a merge.
305 return object_klass;
306 } else if (k1->is_interface() != k2->is_interface()) {
307 // When an interface meets a non-interface, we get Object;
308 // This is what the verifier does.
309 return object_klass;
310 } else if (k1->is_array_klass() || k2->is_array_klass()) {
311 // When an array meets a non-array, we get Object.
312 // When objArray meets typeArray, we also get Object.
313 // And when typeArray meets different typeArray, we again get Object.
314 // But when objArray meets objArray, we look carefully at element types.
315 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
316 // Meet the element types, then construct the corresponding array type.
317 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
318 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
319 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
320 // Do an easy shortcut if one type is a super of the other.
321 if (elem == elem1) {
322 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
323 return k1;
324 } else if (elem == elem2) {
325 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
326 return k2;
327 } else {
328 return ciObjArrayKlass::make(elem);
329 }
330 } else {
331 return object_klass;
332 }
333 } else {
334 // Must be two plain old instance klasses.
335 assert(k1->is_instance_klass(), "previous cases handle non-instances");
336 assert(k2->is_instance_klass(), "previous cases handle non-instances");
337 return k1->least_common_ancestor(k2);
338 }
339 }
340 }
341
342
343 // ------------------------------------------------------------------
344 // ciTypeFlow::StateVector::StateVector
345 //
346 // Build a new state vector
347 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
348 _outer = analyzer;
349 _stack_size = -1;
350 _monitor_count = -1;
351 // Allocate the _types array
352 int max_cells = analyzer->max_cells();
353 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
354 for (int i=0; i<max_cells; i++) {
355 _types[i] = top_type();
356 }
357 _trap_bci = -1;
358 _trap_index = 0;
359 _def_locals.clear();
360 }
361
362
363 // ------------------------------------------------------------------
364 // ciTypeFlow::get_start_state
365 //
366 // Set this vector to the method entry state.
367 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
368 StateVector* state = new StateVector(this);
369 if (is_osr_flow()) {
370 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
371 if (non_osr_flow->failing()) {
372 record_failure(non_osr_flow->failure_reason());
373 return NULL;
374 }
375 JsrSet* jsrs = new JsrSet(NULL, 16);
376 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
377 if (non_osr_block == NULL) {
378 record_failure("cannot reach OSR point");
379 return NULL;
380 }
381 // load up the non-OSR state at this point
382 non_osr_block->copy_state_into(state);
383 int non_osr_start = non_osr_block->start();
384 if (non_osr_start != start_bci()) {
385 // must flow forward from it
386 if (CITraceTypeFlow) {
387 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
388 }
389 Block* block = block_at(non_osr_start, jsrs);
390 assert(block->limit() == start_bci(), "must flow forward to start");
391 flow_block(block, state, jsrs);
392 }
393 return state;
394 // Note: The code below would be an incorrect for an OSR flow,
395 // even if it were possible for an OSR entry point to be at bci zero.
396 }
397 // "Push" the method signature into the first few locals.
398 state->set_stack_size(-max_locals());
399 if (!method()->is_static()) {
400 state->push(method()->holder());
401 assert(state->tos() == state->local(0), "");
402 }
403 for (ciSignatureStream str(method()->signature());
404 !str.at_return_type();
405 str.next()) {
406 state->push_translate(str.type());
407 }
408 // Set the rest of the locals to bottom.
409 Cell cell = state->next_cell(state->tos());
410 state->set_stack_size(0);
411 int limit = state->limit_cell();
412 for (; cell < limit; cell = state->next_cell(cell)) {
413 state->set_type_at(cell, state->bottom_type());
414 }
415 // Lock an object, if necessary.
416 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
417 return state;
418 }
419
420 // ------------------------------------------------------------------
421 // ciTypeFlow::StateVector::copy_into
422 //
423 // Copy our value into some other StateVector
424 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
425 const {
426 copy->set_stack_size(stack_size());
427 copy->set_monitor_count(monitor_count());
428 Cell limit = limit_cell();
429 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
430 copy->set_type_at(c, type_at(c));
431 }
432 }
433
434 // ------------------------------------------------------------------
435 // ciTypeFlow::StateVector::meet
436 //
437 // Meets this StateVector with another, destructively modifying this
438 // one. Returns true if any modification takes place.
439 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
440 if (monitor_count() == -1) {
441 set_monitor_count(incoming->monitor_count());
442 }
443 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
444
445 if (stack_size() == -1) {
446 set_stack_size(incoming->stack_size());
447 Cell limit = limit_cell();
448 #ifdef ASSERT
449 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
450 assert(type_at(c) == top_type(), "");
451 } }
452 #endif
453 // Make a simple copy of the incoming state.
454 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
455 set_type_at(c, incoming->type_at(c));
456 }
457 return true; // it is always different the first time
458 }
459 #ifdef ASSERT
460 if (stack_size() != incoming->stack_size()) {
461 _outer->method()->print_codes();
462 tty->print_cr("!!!! Stack size conflict");
463 tty->print_cr("Current state:");
464 print_on(tty);
465 tty->print_cr("Incoming state:");
466 ((StateVector*)incoming)->print_on(tty);
467 }
468 #endif
469 assert(stack_size() == incoming->stack_size(), "sanity");
470
471 bool different = false;
472 Cell limit = limit_cell();
473 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
474 ciType* t1 = type_at(c);
475 ciType* t2 = incoming->type_at(c);
476 if (!t1->equals(t2)) {
477 ciType* new_type = type_meet(t1, t2);
478 if (!t1->equals(new_type)) {
479 set_type_at(c, new_type);
480 different = true;
481 }
482 }
483 }
484 return different;
485 }
486
487 // ------------------------------------------------------------------
488 // ciTypeFlow::StateVector::meet_exception
489 //
490 // Meets this StateVector with another, destructively modifying this
491 // one. The incoming state is coming via an exception. Returns true
492 // if any modification takes place.
493 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
494 const ciTypeFlow::StateVector* incoming) {
495 if (monitor_count() == -1) {
496 set_monitor_count(incoming->monitor_count());
497 }
498 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
499
500 if (stack_size() == -1) {
501 set_stack_size(1);
502 }
503
504 assert(stack_size() == 1, "must have one-element stack");
505
506 bool different = false;
507
508 // Meet locals from incoming array.
509 Cell limit = local(_outer->max_locals()-1);
510 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
511 ciType* t1 = type_at(c);
512 ciType* t2 = incoming->type_at(c);
513 if (!t1->equals(t2)) {
514 ciType* new_type = type_meet(t1, t2);
515 if (!t1->equals(new_type)) {
516 set_type_at(c, new_type);
517 different = true;
518 }
519 }
520 }
521
522 // Handle stack separately. When an exception occurs, the
523 // only stack entry is the exception instance.
524 ciType* tos_type = type_at_tos();
525 if (!tos_type->equals(exc)) {
526 ciType* new_type = type_meet(tos_type, exc);
527 if (!tos_type->equals(new_type)) {
528 set_type_at_tos(new_type);
529 different = true;
530 }
531 }
532
533 return different;
534 }
535
536 // ------------------------------------------------------------------
537 // ciTypeFlow::StateVector::push_translate
538 void ciTypeFlow::StateVector::push_translate(ciType* type) {
539 BasicType basic_type = type->basic_type();
540 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
541 basic_type == T_BYTE || basic_type == T_SHORT) {
542 push_int();
543 } else {
544 push(type);
545 if (type->is_two_word()) {
546 push(half_type(type));
547 }
548 }
549 }
550
551 // ------------------------------------------------------------------
552 // ciTypeFlow::StateVector::do_aload
553 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
554 pop_int();
555 ciArrayKlass* array_klass = pop_objOrValueArray();
556 if (array_klass == NULL) {
557 // Did aload on a null reference; push a null and ignore the exception.
558 // This instruction will never continue normally. All we have to do
559 // is report a value that will meet correctly with any downstream
560 // reference types on paths that will truly be executed. This null type
561 // meets with any reference type to yield that same reference type.
562 // (The compiler will generate an unconditional exception here.)
563 push(null_type());
564 return;
565 }
566 if (!array_klass->is_loaded()) {
567 // Only fails for some -Xcomp runs
568 trap(str, array_klass,
569 Deoptimization::make_trap_request
570 (Deoptimization::Reason_unloaded,
571 Deoptimization::Action_reinterpret));
572 return;
573 }
574 ciKlass* element_klass = array_klass->element_klass();
575 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
576 Untested("unloaded array element class in ciTypeFlow");
577 trap(str, element_klass,
578 Deoptimization::make_trap_request
579 (Deoptimization::Reason_unloaded,
580 Deoptimization::Action_reinterpret));
581 } else {
582 push_object(element_klass);
583 }
584 }
585
586
587 // ------------------------------------------------------------------
588 // ciTypeFlow::StateVector::do_checkcast
589 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
590 bool will_link;
591 ciKlass* klass = str->get_klass(will_link);
592 if (!will_link) {
593 // VM's interpreter will not load 'klass' if object is NULL.
594 // Type flow after this block may still be needed in two situations:
595 // 1) C2 uses do_null_assert() and continues compilation for later blocks
596 // 2) C2 does an OSR compile in a later block (see bug 4778368).
597 pop_object();
598 do_null_assert(klass);
599 } else {
600 pop_object();
601 push_object(klass);
602 }
603 }
604
605 // ------------------------------------------------------------------
606 // ciTypeFlow::StateVector::do_getfield
607 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
608 // could add assert here for type of object.
609 pop_object();
610 do_getstatic(str);
611 }
612
613 // ------------------------------------------------------------------
614 // ciTypeFlow::StateVector::do_getstatic
615 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
616 bool will_link;
617 ciField* field = str->get_field(will_link);
618 if (!will_link) {
619 trap(str, field->holder(), str->get_field_holder_index());
620 } else {
621 ciType* field_type = field->type();
622 if (!field_type->is_loaded()) {
623 // Normally, we need the field's type to be loaded if we are to
624 // do anything interesting with its value.
625 // We used to do this: trap(str, str->get_field_signature_index());
626 //
627 // There is one good reason not to trap here. Execution can
628 // get past this "getfield" or "getstatic" if the value of
629 // the field is null. As long as the value is null, the class
630 // does not need to be loaded! The compiler must assume that
631 // the value of the unloaded class reference is null; if the code
632 // ever sees a non-null value, loading has occurred.
633 //
634 // This actually happens often enough to be annoying. If the
635 // compiler throws an uncommon trap at this bytecode, you can
636 // get an endless loop of recompilations, when all the code
637 // needs to do is load a series of null values. Also, a trap
638 // here can make an OSR entry point unreachable, triggering the
639 // assert on non_osr_block in ciTypeFlow::get_start_state.
640 // (See bug 4379915.)
641 do_null_assert(field_type->as_klass());
642 } else {
643 push_translate(field_type);
644 }
645 }
646 }
647
648 // ------------------------------------------------------------------
649 // ciTypeFlow::StateVector::do_invoke
650 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
651 bool has_receiver) {
652 bool will_link;
653 ciSignature* declared_signature = NULL;
654 ciMethod* callee = str->get_method(will_link, &declared_signature);
655 assert(declared_signature != NULL, "cannot be null");
656 if (!will_link) {
657 // We weren't able to find the method.
658 if (str->cur_bc() == Bytecodes::_invokedynamic) {
659 trap(str, NULL,
660 Deoptimization::make_trap_request
661 (Deoptimization::Reason_uninitialized,
662 Deoptimization::Action_reinterpret));
663 } else {
664 ciKlass* unloaded_holder = callee->holder();
665 trap(str, unloaded_holder, str->get_method_holder_index());
666 }
667 } else {
668 // We are using the declared signature here because it might be
669 // different from the callee signature (Cf. invokedynamic and
670 // invokehandle).
671 ciSignatureStream sigstr(declared_signature);
672 const int arg_size = declared_signature->size();
673 const int stack_base = stack_size() - arg_size;
674 int i = 0;
675 for( ; !sigstr.at_return_type(); sigstr.next()) {
676 ciType* type = sigstr.type();
677 ciType* stack_type = type_at(stack(stack_base + i++));
678 // Do I want to check this type?
679 // assert(stack_type->is_subtype_of(type), "bad type for field value");
680 if (type->is_two_word()) {
681 ciType* stack_type2 = type_at(stack(stack_base + i++));
682 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
683 }
684 }
685 assert(arg_size == i, "must match");
686 for (int j = 0; j < arg_size; j++) {
687 pop();
688 }
689 if (has_receiver) {
690 // Check this?
691 pop_object();
692 }
693 assert(!sigstr.is_done(), "must have return type");
694 ciType* return_type = sigstr.type();
695 if (!return_type->is_void()) {
696 if (!return_type->is_loaded()) {
697 // As in do_getstatic(), generally speaking, we need the return type to
698 // be loaded if we are to do anything interesting with its value.
699 // We used to do this: trap(str, str->get_method_signature_index());
700 //
701 // We do not trap here since execution can get past this invoke if
702 // the return value is null. As long as the value is null, the class
703 // does not need to be loaded! The compiler must assume that
704 // the value of the unloaded class reference is null; if the code
705 // ever sees a non-null value, loading has occurred.
706 //
707 // See do_getstatic() for similar explanation, as well as bug 4684993.
708 do_null_assert(return_type->as_klass());
709 } else {
710 push_translate(return_type);
711 }
712 }
713 }
714 }
715
716 // ------------------------------------------------------------------
717 // ciTypeFlow::StateVector::do_jsr
718 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
719 push(ciReturnAddress::make(str->next_bci()));
720 }
721
722 // ------------------------------------------------------------------
723 // ciTypeFlow::StateVector::do_ldc
724 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
725 ciConstant con = str->get_constant();
726 BasicType basic_type = con.basic_type();
727 if (basic_type == T_ILLEGAL) {
728 // OutOfMemoryError in the CI while loading constant
729 push_null();
730 outer()->record_failure("ldc did not link");
731 return;
732 }
733 if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
734 ciObject* obj = con.as_object();
735 if (obj->is_null_object()) {
736 push_null();
737 } else {
738 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
739 push_object(obj->klass());
740 }
741 } else {
742 push_translate(ciType::make(basic_type));
743 }
744 }
745
746 // ------------------------------------------------------------------
747 // ciTypeFlow::StateVector::do_multianewarray
748 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
749 int dimensions = str->get_dimensions();
750 bool will_link;
751 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
752 if (!will_link) {
753 trap(str, array_klass, str->get_klass_index());
754 } else {
755 for (int i = 0; i < dimensions; i++) {
756 pop_int();
757 }
758 push_object(array_klass);
759 }
760 }
761
762 // ------------------------------------------------------------------
763 // ciTypeFlow::StateVector::do_new
764 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
765 bool will_link;
766 ciKlass* klass = str->get_klass(will_link);
767 if (!will_link || str->is_unresolved_klass()) {
768 trap(str, klass, str->get_klass_index());
769 } else {
770 push_object(klass);
771 }
772 }
773
774 // ------------------------------------------------------------------
775 // ciTypeFlow::StateVector::do_vdefault
776 void ciTypeFlow::StateVector::do_vdefault(ciBytecodeStream* str) {
777 bool will_link;
778 ciKlass* klass = str->get_klass(will_link);
779 assert(klass->is_valuetype(), "should be value type");
780 if (!will_link || str->is_unresolved_value_type()) {
781 trap(str, klass, str->get_klass_index());
782 } else {
783 push_object(klass);
784 }
785 }
786
787 // ------------------------------------------------------------------
788 // ciTypeFlow::StateVector::do_vwithfield
789 void ciTypeFlow::StateVector::do_vwithfield(ciBytecodeStream* str) {
790 bool will_link;
791 ciField* field = str->get_field(will_link);
792 ciKlass* klass = field->holder();
793 assert(klass->is_valuetype(), "should be value type");
794 if (!will_link) {
795 trap(str, klass, str->get_field_holder_index());
796 } else {
797 ciType* type = pop_value();
798 ciType* field_type = field->type();
799 assert(field_type->is_loaded(), "field type must be loaded");
800 if (field_type->is_two_word()) {
801 ciType* type2 = pop_value();
802 assert(type2->is_two_word(), "must be 2nd half");
803 assert(type == half_type(type2), "must be 2nd half");
804 }
805 pop_object();
806 push_object(klass);
807 }
808 }
809
810 // ------------------------------------------------------------------
811 // ciTypeFlow::StateVector::do_newarray
812 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
813 pop_int();
814 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
815 push_object(klass);
816 }
817
818 // ------------------------------------------------------------------
819 // ciTypeFlow::StateVector::do_putfield
820 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
821 do_putstatic(str);
822 if (_trap_bci != -1) return; // unloaded field holder, etc.
823 // could add assert here for type of object.
824 pop_object();
825 }
826
827 // ------------------------------------------------------------------
828 // ciTypeFlow::StateVector::do_putstatic
829 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
830 bool will_link;
831 ciField* field = str->get_field(will_link);
832 if (!will_link) {
833 trap(str, field->holder(), str->get_field_holder_index());
834 } else {
835 ciType* field_type = field->type();
836 ciType* type = pop_value();
837 // Do I want to check this type?
838 // assert(type->is_subtype_of(field_type), "bad type for field value");
839 if (field_type->is_two_word()) {
840 ciType* type2 = pop_value();
841 assert(type2->is_two_word(), "must be 2nd half");
842 assert(type == half_type(type2), "must be 2nd half");
843 }
844 }
845 }
846
847 // ------------------------------------------------------------------
848 // ciTypeFlow::StateVector::do_ret
849 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
850 Cell index = local(str->get_index());
851
852 ciType* address = type_at(index);
853 assert(address->is_return_address(), "bad return address");
854 set_type_at(index, bottom_type());
855 }
856
857 void ciTypeFlow::StateVector::do_vunbox(ciBytecodeStream* str) {
858 bool will_link;
859 ciKlass* klass = str->get_klass(will_link);
860 // TODO: Handle case when class is not loaded.
861 guarantee(will_link, "Class to which the value-capable class will unbox to must be loaded for JIT compilation");
862 assert(klass->is_instance_klass(), "must be an instance class");
863 pop_object();
864 push_object(klass->as_instance_klass());
865 }
866
867 void ciTypeFlow::StateVector::do_vbox(ciBytecodeStream* str) {
868 bool will_link;
869 ciKlass* klass = str->get_klass(will_link);
870 // TODO: Handle case when class is not loaded.
871 guarantee(will_link, "Class to which value type will box to must be loaded for JIT compilation");
872 assert(klass->is_instance_klass(), "must be an instance class");
873 pop_object();
874 push_object(klass->as_instance_klass());
875 }
876
877 // ------------------------------------------------------------------
878 // ciTypeFlow::StateVector::trap
879 //
880 // Stop interpretation of this path with a trap.
881 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
882 _trap_bci = str->cur_bci();
883 _trap_index = index;
884
885 // Log information about this trap:
886 CompileLog* log = outer()->env()->log();
887 if (log != NULL) {
888 int mid = log->identify(outer()->method());
889 int kid = (klass == NULL)? -1: log->identify(klass);
890 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
891 char buf[100];
892 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
893 index));
894 if (kid >= 0)
895 log->print(" klass='%d'", kid);
896 log->end_elem();
897 }
898 }
899
900 // ------------------------------------------------------------------
901 // ciTypeFlow::StateVector::do_null_assert
902 // Corresponds to graphKit::do_null_assert.
903 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
904 if (unloaded_klass->is_loaded()) {
905 // We failed to link, but we can still compute with this class,
906 // since it is loaded somewhere. The compiler will uncommon_trap
907 // if the object is not null, but the typeflow pass can not assume
908 // that the object will be null, otherwise it may incorrectly tell
909 // the parser that an object is known to be null. 4761344, 4807707
910 push_object(unloaded_klass);
911 } else {
912 // The class is not loaded anywhere. It is safe to model the
913 // null in the typestates, because we can compile in a null check
914 // which will deoptimize us if someone manages to load the
915 // class later.
916 push_null();
917 }
918 }
919
920
921 // ------------------------------------------------------------------
922 // ciTypeFlow::StateVector::apply_one_bytecode
923 //
924 // Apply the effect of one bytecode to this StateVector
925 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
926 _trap_bci = -1;
927 _trap_index = 0;
928
929 if (CITraceTypeFlow) {
930 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
931 Bytecodes::name(str->cur_bc()));
932 }
933
934 switch(str->cur_bc()) {
935 case Bytecodes::_vaload:
936 case Bytecodes::_aaload: do_aload(str); break;
937
938 case Bytecodes::_vastore:
939 case Bytecodes::_aastore:
940 {
941 pop_object();
942 pop_int();
943 pop_objOrValueArray();
944 break;
945 }
946 case Bytecodes::_aconst_null:
947 {
948 push_null();
949 break;
950 }
951 case Bytecodes::_vload:
952 case Bytecodes::_aload: load_local_object(str->get_index()); break;
953 case Bytecodes::_aload_0: load_local_object(0); break;
954 case Bytecodes::_aload_1: load_local_object(1); break;
955 case Bytecodes::_aload_2: load_local_object(2); break;
956 case Bytecodes::_aload_3: load_local_object(3); break;
957
958 case Bytecodes::_anewarray:
959 {
960 pop_int();
961 bool will_link;
962 ciKlass* element_klass = str->get_klass(will_link);
963 if (!will_link) {
964 trap(str, element_klass, str->get_klass_index());
965 } else {
966 push_object(ciArrayKlass::make(element_klass));
967 }
968 break;
969 }
970 case Bytecodes::_areturn:
971 case Bytecodes::_vreturn:
972 case Bytecodes::_ifnonnull:
973 case Bytecodes::_ifnull:
974 {
975 pop_object();
976 break;
977 }
978 case Bytecodes::_monitorenter:
979 {
980 pop_object();
981 set_monitor_count(monitor_count() + 1);
982 break;
983 }
984 case Bytecodes::_monitorexit:
985 {
986 pop_object();
987 assert(monitor_count() > 0, "must be a monitor to exit from");
988 set_monitor_count(monitor_count() - 1);
989 break;
990 }
991 case Bytecodes::_arraylength:
992 {
993 pop_array();
994 push_int();
995 break;
996 }
997 case Bytecodes::_vstore:
998 case Bytecodes::_astore: store_local_object(str->get_index()); break;
999 case Bytecodes::_astore_0: store_local_object(0); break;
1000 case Bytecodes::_astore_1: store_local_object(1); break;
1001 case Bytecodes::_astore_2: store_local_object(2); break;
1002 case Bytecodes::_astore_3: store_local_object(3); break;
1003
1004 case Bytecodes::_athrow:
1005 {
1006 NEEDS_CLEANUP;
1007 pop_object();
1008 break;
1009 }
1010 case Bytecodes::_baload:
1011 case Bytecodes::_caload:
1012 case Bytecodes::_iaload:
1013 case Bytecodes::_saload:
1014 {
1015 pop_int();
1016 ciTypeArrayKlass* array_klass = pop_typeArray();
1017 // Put assert here for right type?
1018 push_int();
1019 break;
1020 }
1021 case Bytecodes::_bastore:
1022 case Bytecodes::_castore:
1023 case Bytecodes::_iastore:
1024 case Bytecodes::_sastore:
1025 {
1026 pop_int();
1027 pop_int();
1028 pop_typeArray();
1029 // assert here?
1030 break;
1031 }
1032 case Bytecodes::_bipush:
1033 case Bytecodes::_iconst_m1:
1034 case Bytecodes::_iconst_0:
1035 case Bytecodes::_iconst_1:
1036 case Bytecodes::_iconst_2:
1037 case Bytecodes::_iconst_3:
1038 case Bytecodes::_iconst_4:
1039 case Bytecodes::_iconst_5:
1040 case Bytecodes::_sipush:
1041 {
1042 push_int();
1043 break;
1044 }
1045 case Bytecodes::_checkcast: do_checkcast(str); break;
1046
1047 case Bytecodes::_d2f:
1048 {
1049 pop_double();
1050 push_float();
1051 break;
1052 }
1053 case Bytecodes::_d2i:
1054 {
1055 pop_double();
1056 push_int();
1057 break;
1058 }
1059 case Bytecodes::_d2l:
1060 {
1061 pop_double();
1062 push_long();
1063 break;
1064 }
1065 case Bytecodes::_dadd:
1066 case Bytecodes::_ddiv:
1067 case Bytecodes::_dmul:
1068 case Bytecodes::_drem:
1069 case Bytecodes::_dsub:
1070 {
1071 pop_double();
1072 pop_double();
1073 push_double();
1074 break;
1075 }
1076 case Bytecodes::_daload:
1077 {
1078 pop_int();
1079 ciTypeArrayKlass* array_klass = pop_typeArray();
1080 // Put assert here for right type?
1081 push_double();
1082 break;
1083 }
1084 case Bytecodes::_dastore:
1085 {
1086 pop_double();
1087 pop_int();
1088 pop_typeArray();
1089 // assert here?
1090 break;
1091 }
1092 case Bytecodes::_dcmpg:
1093 case Bytecodes::_dcmpl:
1094 {
1095 pop_double();
1096 pop_double();
1097 push_int();
1098 break;
1099 }
1100 case Bytecodes::_dconst_0:
1101 case Bytecodes::_dconst_1:
1102 {
1103 push_double();
1104 break;
1105 }
1106 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1107 case Bytecodes::_dload_0: load_local_double(0); break;
1108 case Bytecodes::_dload_1: load_local_double(1); break;
1109 case Bytecodes::_dload_2: load_local_double(2); break;
1110 case Bytecodes::_dload_3: load_local_double(3); break;
1111
1112 case Bytecodes::_dneg:
1113 {
1114 pop_double();
1115 push_double();
1116 break;
1117 }
1118 case Bytecodes::_dreturn:
1119 {
1120 pop_double();
1121 break;
1122 }
1123 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1124 case Bytecodes::_dstore_0: store_local_double(0); break;
1125 case Bytecodes::_dstore_1: store_local_double(1); break;
1126 case Bytecodes::_dstore_2: store_local_double(2); break;
1127 case Bytecodes::_dstore_3: store_local_double(3); break;
1128
1129 case Bytecodes::_dup:
1130 {
1131 push(type_at_tos());
1132 break;
1133 }
1134 case Bytecodes::_dup_x1:
1135 {
1136 ciType* value1 = pop_value();
1137 ciType* value2 = pop_value();
1138 push(value1);
1139 push(value2);
1140 push(value1);
1141 break;
1142 }
1143 case Bytecodes::_dup_x2:
1144 {
1145 ciType* value1 = pop_value();
1146 ciType* value2 = pop_value();
1147 ciType* value3 = pop_value();
1148 push(value1);
1149 push(value3);
1150 push(value2);
1151 push(value1);
1152 break;
1153 }
1154 case Bytecodes::_dup2:
1155 {
1156 ciType* value1 = pop_value();
1157 ciType* value2 = pop_value();
1158 push(value2);
1159 push(value1);
1160 push(value2);
1161 push(value1);
1162 break;
1163 }
1164 case Bytecodes::_dup2_x1:
1165 {
1166 ciType* value1 = pop_value();
1167 ciType* value2 = pop_value();
1168 ciType* value3 = pop_value();
1169 push(value2);
1170 push(value1);
1171 push(value3);
1172 push(value2);
1173 push(value1);
1174 break;
1175 }
1176 case Bytecodes::_dup2_x2:
1177 {
1178 ciType* value1 = pop_value();
1179 ciType* value2 = pop_value();
1180 ciType* value3 = pop_value();
1181 ciType* value4 = pop_value();
1182 push(value2);
1183 push(value1);
1184 push(value4);
1185 push(value3);
1186 push(value2);
1187 push(value1);
1188 break;
1189 }
1190 case Bytecodes::_f2d:
1191 {
1192 pop_float();
1193 push_double();
1194 break;
1195 }
1196 case Bytecodes::_f2i:
1197 {
1198 pop_float();
1199 push_int();
1200 break;
1201 }
1202 case Bytecodes::_f2l:
1203 {
1204 pop_float();
1205 push_long();
1206 break;
1207 }
1208 case Bytecodes::_fadd:
1209 case Bytecodes::_fdiv:
1210 case Bytecodes::_fmul:
1211 case Bytecodes::_frem:
1212 case Bytecodes::_fsub:
1213 {
1214 pop_float();
1215 pop_float();
1216 push_float();
1217 break;
1218 }
1219 case Bytecodes::_faload:
1220 {
1221 pop_int();
1222 ciTypeArrayKlass* array_klass = pop_typeArray();
1223 // Put assert here.
1224 push_float();
1225 break;
1226 }
1227 case Bytecodes::_fastore:
1228 {
1229 pop_float();
1230 pop_int();
1231 ciTypeArrayKlass* array_klass = pop_typeArray();
1232 // Put assert here.
1233 break;
1234 }
1235 case Bytecodes::_fcmpg:
1236 case Bytecodes::_fcmpl:
1237 {
1238 pop_float();
1239 pop_float();
1240 push_int();
1241 break;
1242 }
1243 case Bytecodes::_fconst_0:
1244 case Bytecodes::_fconst_1:
1245 case Bytecodes::_fconst_2:
1246 {
1247 push_float();
1248 break;
1249 }
1250 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1251 case Bytecodes::_fload_0: load_local_float(0); break;
1252 case Bytecodes::_fload_1: load_local_float(1); break;
1253 case Bytecodes::_fload_2: load_local_float(2); break;
1254 case Bytecodes::_fload_3: load_local_float(3); break;
1255
1256 case Bytecodes::_fneg:
1257 {
1258 pop_float();
1259 push_float();
1260 break;
1261 }
1262 case Bytecodes::_freturn:
1263 {
1264 pop_float();
1265 break;
1266 }
1267 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1268 case Bytecodes::_fstore_0: store_local_float(0); break;
1269 case Bytecodes::_fstore_1: store_local_float(1); break;
1270 case Bytecodes::_fstore_2: store_local_float(2); break;
1271 case Bytecodes::_fstore_3: store_local_float(3); break;
1272
1273 case Bytecodes::_getfield: do_getfield(str); break;
1274 case Bytecodes::_getstatic: do_getstatic(str); break;
1275
1276 case Bytecodes::_goto:
1277 case Bytecodes::_goto_w:
1278 case Bytecodes::_nop:
1279 case Bytecodes::_return:
1280 {
1281 // do nothing.
1282 break;
1283 }
1284 case Bytecodes::_i2b:
1285 case Bytecodes::_i2c:
1286 case Bytecodes::_i2s:
1287 case Bytecodes::_ineg:
1288 {
1289 pop_int();
1290 push_int();
1291 break;
1292 }
1293 case Bytecodes::_i2d:
1294 {
1295 pop_int();
1296 push_double();
1297 break;
1298 }
1299 case Bytecodes::_i2f:
1300 {
1301 pop_int();
1302 push_float();
1303 break;
1304 }
1305 case Bytecodes::_i2l:
1306 {
1307 pop_int();
1308 push_long();
1309 break;
1310 }
1311 case Bytecodes::_iadd:
1312 case Bytecodes::_iand:
1313 case Bytecodes::_idiv:
1314 case Bytecodes::_imul:
1315 case Bytecodes::_ior:
1316 case Bytecodes::_irem:
1317 case Bytecodes::_ishl:
1318 case Bytecodes::_ishr:
1319 case Bytecodes::_isub:
1320 case Bytecodes::_iushr:
1321 case Bytecodes::_ixor:
1322 {
1323 pop_int();
1324 pop_int();
1325 push_int();
1326 break;
1327 }
1328 case Bytecodes::_if_acmpeq:
1329 case Bytecodes::_if_acmpne:
1330 {
1331 pop_object();
1332 pop_object();
1333 break;
1334 }
1335 case Bytecodes::_if_icmpeq:
1336 case Bytecodes::_if_icmpge:
1337 case Bytecodes::_if_icmpgt:
1338 case Bytecodes::_if_icmple:
1339 case Bytecodes::_if_icmplt:
1340 case Bytecodes::_if_icmpne:
1341 {
1342 pop_int();
1343 pop_int();
1344 break;
1345 }
1346 case Bytecodes::_ifeq:
1347 case Bytecodes::_ifle:
1348 case Bytecodes::_iflt:
1349 case Bytecodes::_ifge:
1350 case Bytecodes::_ifgt:
1351 case Bytecodes::_ifne:
1352 case Bytecodes::_ireturn:
1353 case Bytecodes::_lookupswitch:
1354 case Bytecodes::_tableswitch:
1355 {
1356 pop_int();
1357 break;
1358 }
1359 case Bytecodes::_iinc:
1360 {
1361 int lnum = str->get_index();
1362 check_int(local(lnum));
1363 store_to_local(lnum);
1364 break;
1365 }
1366 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1367 case Bytecodes::_iload_0: load_local_int(0); break;
1368 case Bytecodes::_iload_1: load_local_int(1); break;
1369 case Bytecodes::_iload_2: load_local_int(2); break;
1370 case Bytecodes::_iload_3: load_local_int(3); break;
1371
1372 case Bytecodes::_instanceof:
1373 {
1374 // Check for uncommon trap:
1375 do_checkcast(str);
1376 pop_object();
1377 push_int();
1378 break;
1379 }
1380 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1381 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1382 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1383 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1384 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1385
1386 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1387 case Bytecodes::_istore_0: store_local_int(0); break;
1388 case Bytecodes::_istore_1: store_local_int(1); break;
1389 case Bytecodes::_istore_2: store_local_int(2); break;
1390 case Bytecodes::_istore_3: store_local_int(3); break;
1391
1392 case Bytecodes::_jsr:
1393 case Bytecodes::_jsr_w: do_jsr(str); break;
1394
1395 case Bytecodes::_l2d:
1396 {
1397 pop_long();
1398 push_double();
1399 break;
1400 }
1401 case Bytecodes::_l2f:
1402 {
1403 pop_long();
1404 push_float();
1405 break;
1406 }
1407 case Bytecodes::_l2i:
1408 {
1409 pop_long();
1410 push_int();
1411 break;
1412 }
1413 case Bytecodes::_ladd:
1414 case Bytecodes::_land:
1415 case Bytecodes::_ldiv:
1416 case Bytecodes::_lmul:
1417 case Bytecodes::_lor:
1418 case Bytecodes::_lrem:
1419 case Bytecodes::_lsub:
1420 case Bytecodes::_lxor:
1421 {
1422 pop_long();
1423 pop_long();
1424 push_long();
1425 break;
1426 }
1427 case Bytecodes::_laload:
1428 {
1429 pop_int();
1430 ciTypeArrayKlass* array_klass = pop_typeArray();
1431 // Put assert here for right type?
1432 push_long();
1433 break;
1434 }
1435 case Bytecodes::_lastore:
1436 {
1437 pop_long();
1438 pop_int();
1439 pop_typeArray();
1440 // assert here?
1441 break;
1442 }
1443 case Bytecodes::_lcmp:
1444 {
1445 pop_long();
1446 pop_long();
1447 push_int();
1448 break;
1449 }
1450 case Bytecodes::_lconst_0:
1451 case Bytecodes::_lconst_1:
1452 {
1453 push_long();
1454 break;
1455 }
1456 case Bytecodes::_ldc:
1457 case Bytecodes::_ldc_w:
1458 case Bytecodes::_ldc2_w:
1459 {
1460 do_ldc(str);
1461 break;
1462 }
1463
1464 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1465 case Bytecodes::_lload_0: load_local_long(0); break;
1466 case Bytecodes::_lload_1: load_local_long(1); break;
1467 case Bytecodes::_lload_2: load_local_long(2); break;
1468 case Bytecodes::_lload_3: load_local_long(3); break;
1469
1470 case Bytecodes::_lneg:
1471 {
1472 pop_long();
1473 push_long();
1474 break;
1475 }
1476 case Bytecodes::_lreturn:
1477 {
1478 pop_long();
1479 break;
1480 }
1481 case Bytecodes::_lshl:
1482 case Bytecodes::_lshr:
1483 case Bytecodes::_lushr:
1484 {
1485 pop_int();
1486 pop_long();
1487 push_long();
1488 break;
1489 }
1490 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1491 case Bytecodes::_lstore_0: store_local_long(0); break;
1492 case Bytecodes::_lstore_1: store_local_long(1); break;
1493 case Bytecodes::_lstore_2: store_local_long(2); break;
1494 case Bytecodes::_lstore_3: store_local_long(3); break;
1495
1496 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1497
1498 case Bytecodes::_new: do_new(str); break;
1499
1500 case Bytecodes::_vdefault: do_vdefault(str); break;
1501 case Bytecodes::_vwithfield: do_vwithfield(str); break;
1502
1503 case Bytecodes::_newarray: do_newarray(str); break;
1504
1505 case Bytecodes::_pop:
1506 {
1507 pop();
1508 break;
1509 }
1510 case Bytecodes::_pop2:
1511 {
1512 pop();
1513 pop();
1514 break;
1515 }
1516
1517 case Bytecodes::_putfield: do_putfield(str); break;
1518 case Bytecodes::_putstatic: do_putstatic(str); break;
1519
1520 case Bytecodes::_ret: do_ret(str); break;
1521
1522 case Bytecodes::_swap:
1523 {
1524 ciType* value1 = pop_value();
1525 ciType* value2 = pop_value();
1526 push(value1);
1527 push(value2);
1528 break;
1529 }
1530 case Bytecodes::_vunbox:
1531 {
1532 do_vunbox(str);
1533 break;
1534 }
1535 case Bytecodes::_vbox:
1536 {
1537 do_vbox(str);
1538 break;
1539 }
1540 case Bytecodes::_wide:
1541 default:
1542 {
1543 // The iterator should skip this.
1544 ShouldNotReachHere();
1545 break;
1546 }
1547 }
1548
1549 if (CITraceTypeFlow) {
1550 print_on(tty);
1551 }
1552
1553 return (_trap_bci != -1);
1554 }
1555
1556 #ifndef PRODUCT
1557 // ------------------------------------------------------------------
1558 // ciTypeFlow::StateVector::print_cell_on
1559 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1560 ciType* type = type_at(c);
1561 if (type == top_type()) {
1562 st->print("top");
1563 } else if (type == bottom_type()) {
1564 st->print("bottom");
1565 } else if (type == null_type()) {
1566 st->print("null");
1567 } else if (type == long2_type()) {
1568 st->print("long2");
1569 } else if (type == double2_type()) {
1570 st->print("double2");
1571 } else if (is_int(type)) {
1572 st->print("int");
1573 } else if (is_long(type)) {
1574 st->print("long");
1575 } else if (is_float(type)) {
1576 st->print("float");
1577 } else if (is_double(type)) {
1578 st->print("double");
1579 } else if (type->is_return_address()) {
1580 st->print("address(%d)", type->as_return_address()->bci());
1581 } else {
1582 if (type->is_klass()) {
1583 type->as_klass()->name()->print_symbol_on(st);
1584 } else {
1585 st->print("UNEXPECTED TYPE");
1586 type->print();
1587 }
1588 }
1589 }
1590
1591 // ------------------------------------------------------------------
1592 // ciTypeFlow::StateVector::print_on
1593 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1594 int num_locals = _outer->max_locals();
1595 int num_stack = stack_size();
1596 int num_monitors = monitor_count();
1597 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1598 if (num_stack >= 0) {
1599 int i;
1600 for (i = 0; i < num_locals; i++) {
1601 st->print(" local %2d : ", i);
1602 print_cell_on(st, local(i));
1603 st->cr();
1604 }
1605 for (i = 0; i < num_stack; i++) {
1606 st->print(" stack %2d : ", i);
1607 print_cell_on(st, stack(i));
1608 st->cr();
1609 }
1610 }
1611 }
1612 #endif
1613
1614
1615 // ------------------------------------------------------------------
1616 // ciTypeFlow::SuccIter::next
1617 //
1618 void ciTypeFlow::SuccIter::next() {
1619 int succ_ct = _pred->successors()->length();
1620 int next = _index + 1;
1621 if (next < succ_ct) {
1622 _index = next;
1623 _succ = _pred->successors()->at(next);
1624 return;
1625 }
1626 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1627 // Do not compile any code for unloaded exception types.
1628 // Following compiler passes are responsible for doing this also.
1629 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1630 if (exception_klass->is_loaded()) {
1631 _index = next;
1632 _succ = _pred->exceptions()->at(i);
1633 return;
1634 }
1635 next++;
1636 }
1637 _index = -1;
1638 _succ = NULL;
1639 }
1640
1641 // ------------------------------------------------------------------
1642 // ciTypeFlow::SuccIter::set_succ
1643 //
1644 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1645 int succ_ct = _pred->successors()->length();
1646 if (_index < succ_ct) {
1647 _pred->successors()->at_put(_index, succ);
1648 } else {
1649 int idx = _index - succ_ct;
1650 _pred->exceptions()->at_put(idx, succ);
1651 }
1652 }
1653
1654 // ciTypeFlow::Block
1655 //
1656 // A basic block.
1657
1658 // ------------------------------------------------------------------
1659 // ciTypeFlow::Block::Block
1660 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1661 ciBlock *ciblk,
1662 ciTypeFlow::JsrSet* jsrs) {
1663 _ciblock = ciblk;
1664 _exceptions = NULL;
1665 _exc_klasses = NULL;
1666 _successors = NULL;
1667 _predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
1668 _state = new (outer->arena()) StateVector(outer);
1669 JsrSet* new_jsrs =
1670 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1671 jsrs->copy_into(new_jsrs);
1672 _jsrs = new_jsrs;
1673 _next = NULL;
1674 _on_work_list = false;
1675 _backedge_copy = false;
1676 _has_monitorenter = false;
1677 _trap_bci = -1;
1678 _trap_index = 0;
1679 df_init();
1680
1681 if (CITraceTypeFlow) {
1682 tty->print_cr(">> Created new block");
1683 print_on(tty);
1684 }
1685
1686 assert(this->outer() == outer, "outer link set up");
1687 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1688 }
1689
1690 // ------------------------------------------------------------------
1691 // ciTypeFlow::Block::df_init
1692 void ciTypeFlow::Block::df_init() {
1693 _pre_order = -1; assert(!has_pre_order(), "");
1694 _post_order = -1; assert(!has_post_order(), "");
1695 _loop = NULL;
1696 _irreducible_entry = false;
1697 _rpo_next = NULL;
1698 }
1699
1700 // ------------------------------------------------------------------
1701 // ciTypeFlow::Block::successors
1702 //
1703 // Get the successors for this Block.
1704 GrowableArray<ciTypeFlow::Block*>*
1705 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1706 ciTypeFlow::StateVector* state,
1707 ciTypeFlow::JsrSet* jsrs) {
1708 if (_successors == NULL) {
1709 if (CITraceTypeFlow) {
1710 tty->print(">> Computing successors for block ");
1711 print_value_on(tty);
1712 tty->cr();
1713 }
1714
1715 ciTypeFlow* analyzer = outer();
1716 Arena* arena = analyzer->arena();
1717 Block* block = NULL;
1718 bool has_successor = !has_trap() &&
1719 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1720 if (!has_successor) {
1721 _successors =
1722 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1723 // No successors
1724 } else if (control() == ciBlock::fall_through_bci) {
1725 assert(str->cur_bci() == limit(), "bad block end");
1726 // This block simply falls through to the next.
1727 _successors =
1728 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1729
1730 Block* block = analyzer->block_at(limit(), _jsrs);
1731 assert(_successors->length() == FALL_THROUGH, "");
1732 _successors->append(block);
1733 } else {
1734 int current_bci = str->cur_bci();
1735 int next_bci = str->next_bci();
1736 int branch_bci = -1;
1737 Block* target = NULL;
1738 assert(str->next_bci() == limit(), "bad block end");
1739 // This block is not a simple fall-though. Interpret
1740 // the current bytecode to find our successors.
1741 switch (str->cur_bc()) {
1742 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1743 case Bytecodes::_iflt: case Bytecodes::_ifge:
1744 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1745 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1746 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1747 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1748 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1749 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1750 // Our successors are the branch target and the next bci.
1751 branch_bci = str->get_dest();
1752 _successors =
1753 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1754 assert(_successors->length() == IF_NOT_TAKEN, "");
1755 _successors->append(analyzer->block_at(next_bci, jsrs));
1756 assert(_successors->length() == IF_TAKEN, "");
1757 _successors->append(analyzer->block_at(branch_bci, jsrs));
1758 break;
1759
1760 case Bytecodes::_goto:
1761 branch_bci = str->get_dest();
1762 _successors =
1763 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1764 assert(_successors->length() == GOTO_TARGET, "");
1765 _successors->append(analyzer->block_at(branch_bci, jsrs));
1766 break;
1767
1768 case Bytecodes::_jsr:
1769 branch_bci = str->get_dest();
1770 _successors =
1771 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1772 assert(_successors->length() == GOTO_TARGET, "");
1773 _successors->append(analyzer->block_at(branch_bci, jsrs));
1774 break;
1775
1776 case Bytecodes::_goto_w:
1777 case Bytecodes::_jsr_w:
1778 _successors =
1779 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1780 assert(_successors->length() == GOTO_TARGET, "");
1781 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1782 break;
1783
1784 case Bytecodes::_tableswitch: {
1785 Bytecode_tableswitch tableswitch(str);
1786
1787 int len = tableswitch.length();
1788 _successors =
1789 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1790 int bci = current_bci + tableswitch.default_offset();
1791 Block* block = analyzer->block_at(bci, jsrs);
1792 assert(_successors->length() == SWITCH_DEFAULT, "");
1793 _successors->append(block);
1794 while (--len >= 0) {
1795 int bci = current_bci + tableswitch.dest_offset_at(len);
1796 block = analyzer->block_at(bci, jsrs);
1797 assert(_successors->length() >= SWITCH_CASES, "");
1798 _successors->append_if_missing(block);
1799 }
1800 break;
1801 }
1802
1803 case Bytecodes::_lookupswitch: {
1804 Bytecode_lookupswitch lookupswitch(str);
1805
1806 int npairs = lookupswitch.number_of_pairs();
1807 _successors =
1808 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1809 int bci = current_bci + lookupswitch.default_offset();
1810 Block* block = analyzer->block_at(bci, jsrs);
1811 assert(_successors->length() == SWITCH_DEFAULT, "");
1812 _successors->append(block);
1813 while(--npairs >= 0) {
1814 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1815 int bci = current_bci + pair.offset();
1816 Block* block = analyzer->block_at(bci, jsrs);
1817 assert(_successors->length() >= SWITCH_CASES, "");
1818 _successors->append_if_missing(block);
1819 }
1820 break;
1821 }
1822
1823 case Bytecodes::_athrow:
1824 case Bytecodes::_ireturn:
1825 case Bytecodes::_lreturn:
1826 case Bytecodes::_freturn:
1827 case Bytecodes::_dreturn:
1828 case Bytecodes::_areturn:
1829 case Bytecodes::_vreturn:
1830 case Bytecodes::_return:
1831 _successors =
1832 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1833 // No successors
1834 break;
1835
1836 case Bytecodes::_ret: {
1837 _successors =
1838 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1839
1840 Cell local = state->local(str->get_index());
1841 ciType* return_address = state->type_at(local);
1842 assert(return_address->is_return_address(), "verify: wrong type");
1843 int bci = return_address->as_return_address()->bci();
1844 assert(_successors->length() == GOTO_TARGET, "");
1845 _successors->append(analyzer->block_at(bci, jsrs));
1846 break;
1847 }
1848
1849 case Bytecodes::_wide:
1850 default:
1851 ShouldNotReachHere();
1852 break;
1853 }
1854 }
1855
1856 // Set predecessor information
1857 for (int i = 0; i < _successors->length(); i++) {
1858 Block* block = _successors->at(i);
1859 block->predecessors()->append(this);
1860 }
1861 }
1862 return _successors;
1863 }
1864
1865 // ------------------------------------------------------------------
1866 // ciTypeFlow::Block:compute_exceptions
1867 //
1868 // Compute the exceptional successors and types for this Block.
1869 void ciTypeFlow::Block::compute_exceptions() {
1870 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1871
1872 if (CITraceTypeFlow) {
1873 tty->print(">> Computing exceptions for block ");
1874 print_value_on(tty);
1875 tty->cr();
1876 }
1877
1878 ciTypeFlow* analyzer = outer();
1879 Arena* arena = analyzer->arena();
1880
1881 // Any bci in the block will do.
1882 ciExceptionHandlerStream str(analyzer->method(), start());
1883
1884 // Allocate our growable arrays.
1885 int exc_count = str.count();
1886 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1887 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1888 0, NULL);
1889
1890 for ( ; !str.is_done(); str.next()) {
1891 ciExceptionHandler* handler = str.handler();
1892 int bci = handler->handler_bci();
1893 ciInstanceKlass* klass = NULL;
1894 if (bci == -1) {
1895 // There is no catch all. It is possible to exit the method.
1896 break;
1897 }
1898 if (handler->is_catch_all()) {
1899 klass = analyzer->env()->Throwable_klass();
1900 } else {
1901 klass = handler->catch_klass();
1902 }
1903 Block* block = analyzer->block_at(bci, _jsrs);
1904 _exceptions->append(block);
1905 block->predecessors()->append(this);
1906 _exc_klasses->append(klass);
1907 }
1908 }
1909
1910 // ------------------------------------------------------------------
1911 // ciTypeFlow::Block::set_backedge_copy
1912 // Use this only to make a pre-existing public block into a backedge copy.
1913 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1914 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1915 _backedge_copy = z;
1916 }
1917
1918 // ------------------------------------------------------------------
1919 // ciTypeFlow::Block::is_clonable_exit
1920 //
1921 // At most 2 normal successors, one of which continues looping,
1922 // and all exceptional successors must exit.
1923 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1924 int normal_cnt = 0;
1925 int in_loop_cnt = 0;
1926 for (SuccIter iter(this); !iter.done(); iter.next()) {
1927 Block* succ = iter.succ();
1928 if (iter.is_normal_ctrl()) {
1929 if (++normal_cnt > 2) return false;
1930 if (lp->contains(succ->loop())) {
1931 if (++in_loop_cnt > 1) return false;
1932 }
1933 } else {
1934 if (lp->contains(succ->loop())) return false;
1935 }
1936 }
1937 return in_loop_cnt == 1;
1938 }
1939
1940 // ------------------------------------------------------------------
1941 // ciTypeFlow::Block::looping_succ
1942 //
1943 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1944 assert(successors()->length() <= 2, "at most 2 normal successors");
1945 for (SuccIter iter(this); !iter.done(); iter.next()) {
1946 Block* succ = iter.succ();
1947 if (lp->contains(succ->loop())) {
1948 return succ;
1949 }
1950 }
1951 return NULL;
1952 }
1953
1954 #ifndef PRODUCT
1955 // ------------------------------------------------------------------
1956 // ciTypeFlow::Block::print_value_on
1957 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1958 if (has_pre_order()) st->print("#%-2d ", pre_order());
1959 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1960 st->print("[%d - %d)", start(), limit());
1961 if (is_loop_head()) st->print(" lphd");
1962 if (is_irreducible_entry()) st->print(" irred");
1963 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1964 if (is_backedge_copy()) st->print("/backedge_copy");
1965 }
1966
1967 // ------------------------------------------------------------------
1968 // ciTypeFlow::Block::print_on
1969 void ciTypeFlow::Block::print_on(outputStream* st) const {
1970 if ((Verbose || WizardMode) && (limit() >= 0)) {
1971 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1972 outer()->method()->print_codes_on(start(), limit(), st);
1973 }
1974 st->print_cr(" ==================================================== ");
1975 st->print (" ");
1976 print_value_on(st);
1977 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1978 if (loop() && loop()->parent() != NULL) {
1979 st->print(" loops:");
1980 Loop* lp = loop();
1981 do {
1982 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1983 if (lp->is_irreducible()) st->print("(ir)");
1984 lp = lp->parent();
1985 } while (lp->parent() != NULL);
1986 }
1987 st->cr();
1988 _state->print_on(st);
1989 if (_successors == NULL) {
1990 st->print_cr(" No successor information");
1991 } else {
1992 int num_successors = _successors->length();
1993 st->print_cr(" Successors : %d", num_successors);
1994 for (int i = 0; i < num_successors; i++) {
1995 Block* successor = _successors->at(i);
1996 st->print(" ");
1997 successor->print_value_on(st);
1998 st->cr();
1999 }
2000 }
2001 if (_predecessors == NULL) {
2002 st->print_cr(" No predecessor information");
2003 } else {
2004 int num_predecessors = _predecessors->length();
2005 st->print_cr(" Predecessors : %d", num_predecessors);
2006 for (int i = 0; i < num_predecessors; i++) {
2007 Block* predecessor = _predecessors->at(i);
2008 st->print(" ");
2009 predecessor->print_value_on(st);
2010 st->cr();
2011 }
2012 }
2013 if (_exceptions == NULL) {
2014 st->print_cr(" No exception information");
2015 } else {
2016 int num_exceptions = _exceptions->length();
2017 st->print_cr(" Exceptions : %d", num_exceptions);
2018 for (int i = 0; i < num_exceptions; i++) {
2019 Block* exc_succ = _exceptions->at(i);
2020 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
2021 st->print(" ");
2022 exc_succ->print_value_on(st);
2023 st->print(" -- ");
2024 exc_klass->name()->print_symbol_on(st);
2025 st->cr();
2026 }
2027 }
2028 if (has_trap()) {
2029 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2030 }
2031 st->print_cr(" ==================================================== ");
2032 }
2033 #endif
2034
2035 #ifndef PRODUCT
2036 // ------------------------------------------------------------------
2037 // ciTypeFlow::LocalSet::print_on
2038 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2039 st->print("{");
2040 for (int i = 0; i < max; i++) {
2041 if (test(i)) st->print(" %d", i);
2042 }
2043 if (limit > max) {
2044 st->print(" %d..%d ", max, limit);
2045 }
2046 st->print(" }");
2047 }
2048 #endif
2049
2050 // ciTypeFlow
2051 //
2052 // This is a pass over the bytecodes which computes the following:
2053 // basic block structure
2054 // interpreter type-states (a la the verifier)
2055
2056 // ------------------------------------------------------------------
2057 // ciTypeFlow::ciTypeFlow
2058 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2059 _env = env;
2060 _method = method;
2061 _methodBlocks = method->get_method_blocks();
2062 _max_locals = method->max_locals();
2063 _max_stack = method->max_stack();
2064 _code_size = method->code_size();
2065 _has_irreducible_entry = false;
2066 _osr_bci = osr_bci;
2067 _failure_reason = NULL;
2068 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2069 _work_list = NULL;
2070
2071 _ciblock_count = _methodBlocks->num_blocks();
2072 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
2073 for (int i = 0; i < _ciblock_count; i++) {
2074 _idx_to_blocklist[i] = NULL;
2075 }
2076 _block_map = NULL; // until all blocks are seen
2077 _jsr_count = 0;
2078 _jsr_records = NULL;
2079 }
2080
2081 // ------------------------------------------------------------------
2082 // ciTypeFlow::work_list_next
2083 //
2084 // Get the next basic block from our work list.
2085 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2086 assert(!work_list_empty(), "work list must not be empty");
2087 Block* next_block = _work_list;
2088 _work_list = next_block->next();
2089 next_block->set_next(NULL);
2090 next_block->set_on_work_list(false);
2091 return next_block;
2092 }
2093
2094 // ------------------------------------------------------------------
2095 // ciTypeFlow::add_to_work_list
2096 //
2097 // Add a basic block to our work list.
2098 // List is sorted by decreasing postorder sort (same as increasing RPO)
2099 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2100 assert(!block->is_on_work_list(), "must not already be on work list");
2101
2102 if (CITraceTypeFlow) {
2103 tty->print(">> Adding block ");
2104 block->print_value_on(tty);
2105 tty->print_cr(" to the work list : ");
2106 }
2107
2108 block->set_on_work_list(true);
2109
2110 // decreasing post order sort
2111
2112 Block* prev = NULL;
2113 Block* current = _work_list;
2114 int po = block->post_order();
2115 while (current != NULL) {
2116 if (!current->has_post_order() || po > current->post_order())
2117 break;
2118 prev = current;
2119 current = current->next();
2120 }
2121 if (prev == NULL) {
2122 block->set_next(_work_list);
2123 _work_list = block;
2124 } else {
2125 block->set_next(current);
2126 prev->set_next(block);
2127 }
2128
2129 if (CITraceTypeFlow) {
2130 tty->cr();
2131 }
2132 }
2133
2134 // ------------------------------------------------------------------
2135 // ciTypeFlow::block_at
2136 //
2137 // Return the block beginning at bci which has a JsrSet compatible
2138 // with jsrs.
2139 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2140 // First find the right ciBlock.
2141 if (CITraceTypeFlow) {
2142 tty->print(">> Requesting block for %d/", bci);
2143 jsrs->print_on(tty);
2144 tty->cr();
2145 }
2146
2147 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2148 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2149 Block* block = get_block_for(ciblk->index(), jsrs, option);
2150
2151 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2152
2153 if (CITraceTypeFlow) {
2154 if (block != NULL) {
2155 tty->print(">> Found block ");
2156 block->print_value_on(tty);
2157 tty->cr();
2158 } else {
2159 tty->print_cr(">> No such block.");
2160 }
2161 }
2162
2163 return block;
2164 }
2165
2166 // ------------------------------------------------------------------
2167 // ciTypeFlow::make_jsr_record
2168 //
2169 // Make a JsrRecord for a given (entry, return) pair, if such a record
2170 // does not already exist.
2171 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2172 int return_address) {
2173 if (_jsr_records == NULL) {
2174 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2175 _jsr_count,
2176 0,
2177 NULL);
2178 }
2179 JsrRecord* record = NULL;
2180 int len = _jsr_records->length();
2181 for (int i = 0; i < len; i++) {
2182 JsrRecord* record = _jsr_records->at(i);
2183 if (record->entry_address() == entry_address &&
2184 record->return_address() == return_address) {
2185 return record;
2186 }
2187 }
2188
2189 record = new (arena()) JsrRecord(entry_address, return_address);
2190 _jsr_records->append(record);
2191 return record;
2192 }
2193
2194 // ------------------------------------------------------------------
2195 // ciTypeFlow::flow_exceptions
2196 //
2197 // Merge the current state into all exceptional successors at the
2198 // current point in the code.
2199 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2200 GrowableArray<ciInstanceKlass*>* exc_klasses,
2201 ciTypeFlow::StateVector* state) {
2202 int len = exceptions->length();
2203 assert(exc_klasses->length() == len, "must have same length");
2204 for (int i = 0; i < len; i++) {
2205 Block* block = exceptions->at(i);
2206 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2207
2208 if (!exception_klass->is_loaded()) {
2209 // Do not compile any code for unloaded exception types.
2210 // Following compiler passes are responsible for doing this also.
2211 continue;
2212 }
2213
2214 if (block->meet_exception(exception_klass, state)) {
2215 // Block was modified and has PO. Add it to the work list.
2216 if (block->has_post_order() &&
2217 !block->is_on_work_list()) {
2218 add_to_work_list(block);
2219 }
2220 }
2221 }
2222 }
2223
2224 // ------------------------------------------------------------------
2225 // ciTypeFlow::flow_successors
2226 //
2227 // Merge the current state into all successors at the current point
2228 // in the code.
2229 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2230 ciTypeFlow::StateVector* state) {
2231 int len = successors->length();
2232 for (int i = 0; i < len; i++) {
2233 Block* block = successors->at(i);
2234 if (block->meet(state)) {
2235 // Block was modified and has PO. Add it to the work list.
2236 if (block->has_post_order() &&
2237 !block->is_on_work_list()) {
2238 add_to_work_list(block);
2239 }
2240 }
2241 }
2242 }
2243
2244 // ------------------------------------------------------------------
2245 // ciTypeFlow::can_trap
2246 //
2247 // Tells if a given instruction is able to generate an exception edge.
2248 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2249 // Cf. GenerateOopMap::do_exception_edge.
2250 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2251
2252 switch (str.cur_bc()) {
2253 // %%% FIXME: ldc of Class can generate an exception
2254 case Bytecodes::_ldc:
2255 case Bytecodes::_ldc_w:
2256 case Bytecodes::_ldc2_w:
2257 case Bytecodes::_aload_0:
2258 // These bytecodes can trap for rewriting. We need to assume that
2259 // they do not throw exceptions to make the monitor analysis work.
2260 return false;
2261
2262 case Bytecodes::_ireturn:
2263 case Bytecodes::_lreturn:
2264 case Bytecodes::_freturn:
2265 case Bytecodes::_dreturn:
2266 case Bytecodes::_areturn:
2267 case Bytecodes::_vreturn:
2268 case Bytecodes::_return:
2269 // We can assume the monitor stack is empty in this analysis.
2270 return false;
2271
2272 case Bytecodes::_monitorexit:
2273 // We can assume monitors are matched in this analysis.
2274 return false;
2275
2276 default:
2277 return true;
2278 }
2279 }
2280
2281 // ------------------------------------------------------------------
2282 // ciTypeFlow::clone_loop_heads
2283 //
2284 // Clone the loop heads
2285 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2286 bool rslt = false;
2287 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2288 lp = iter.current();
2289 Block* head = lp->head();
2290 if (lp == loop_tree_root() ||
2291 lp->is_irreducible() ||
2292 !head->is_clonable_exit(lp))
2293 continue;
2294
2295 // Avoid BoxLock merge.
2296 if (EliminateNestedLocks && head->has_monitorenter())
2297 continue;
2298
2299 // check not already cloned
2300 if (head->backedge_copy_count() != 0)
2301 continue;
2302
2303 // Don't clone head of OSR loop to get correct types in start block.
2304 if (is_osr_flow() && head->start() == start_bci())
2305 continue;
2306
2307 // check _no_ shared head below us
2308 Loop* ch;
2309 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2310 if (ch != NULL)
2311 continue;
2312
2313 // Clone head
2314 Block* new_head = head->looping_succ(lp);
2315 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2316 // Update lp's info
2317 clone->set_loop(lp);
2318 lp->set_head(new_head);
2319 lp->set_tail(clone);
2320 // And move original head into outer loop
2321 head->set_loop(lp->parent());
2322
2323 rslt = true;
2324 }
2325 return rslt;
2326 }
2327
2328 // ------------------------------------------------------------------
2329 // ciTypeFlow::clone_loop_head
2330 //
2331 // Clone lp's head and replace tail's successors with clone.
2332 //
2333 // |
2334 // v
2335 // head <-> body
2336 // |
2337 // v
2338 // exit
2339 //
2340 // new_head
2341 //
2342 // |
2343 // v
2344 // head ----------\
2345 // | |
2346 // | v
2347 // | clone <-> body
2348 // | |
2349 // | /--/
2350 // | |
2351 // v v
2352 // exit
2353 //
2354 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2355 Block* head = lp->head();
2356 Block* tail = lp->tail();
2357 if (CITraceTypeFlow) {
2358 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2359 tty->print(" for predecessor "); tail->print_value_on(tty);
2360 tty->cr();
2361 }
2362 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2363 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2364
2365 assert(!clone->has_pre_order(), "just created");
2366 clone->set_next_pre_order();
2367
2368 // Insert clone after (orig) tail in reverse post order
2369 clone->set_rpo_next(tail->rpo_next());
2370 tail->set_rpo_next(clone);
2371
2372 // tail->head becomes tail->clone
2373 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2374 if (iter.succ() == head) {
2375 iter.set_succ(clone);
2376 // Update predecessor information
2377 head->predecessors()->remove(tail);
2378 clone->predecessors()->append(tail);
2379 }
2380 }
2381 flow_block(tail, temp_vector, temp_set);
2382 if (head == tail) {
2383 // For self-loops, clone->head becomes clone->clone
2384 flow_block(clone, temp_vector, temp_set);
2385 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2386 if (iter.succ() == head) {
2387 iter.set_succ(clone);
2388 // Update predecessor information
2389 head->predecessors()->remove(clone);
2390 clone->predecessors()->append(clone);
2391 break;
2392 }
2393 }
2394 }
2395 flow_block(clone, temp_vector, temp_set);
2396
2397 return clone;
2398 }
2399
2400 // ------------------------------------------------------------------
2401 // ciTypeFlow::flow_block
2402 //
2403 // Interpret the effects of the bytecodes on the incoming state
2404 // vector of a basic block. Push the changed state to succeeding
2405 // basic blocks.
2406 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2407 ciTypeFlow::StateVector* state,
2408 ciTypeFlow::JsrSet* jsrs) {
2409 if (CITraceTypeFlow) {
2410 tty->print("\n>> ANALYZING BLOCK : ");
2411 tty->cr();
2412 block->print_on(tty);
2413 }
2414 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2415
2416 int start = block->start();
2417 int limit = block->limit();
2418 int control = block->control();
2419 if (control != ciBlock::fall_through_bci) {
2420 limit = control;
2421 }
2422
2423 // Grab the state from the current block.
2424 block->copy_state_into(state);
2425 state->def_locals()->clear();
2426
2427 GrowableArray<Block*>* exceptions = block->exceptions();
2428 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2429 bool has_exceptions = exceptions->length() > 0;
2430
2431 bool exceptions_used = false;
2432
2433 ciBytecodeStream str(method());
2434 str.reset_to_bci(start);
2435 Bytecodes::Code code;
2436 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2437 str.cur_bci() < limit) {
2438 // Check for exceptional control flow from this point.
2439 if (has_exceptions && can_trap(str)) {
2440 flow_exceptions(exceptions, exc_klasses, state);
2441 exceptions_used = true;
2442 }
2443 // Apply the effects of the current bytecode to our state.
2444 bool res = state->apply_one_bytecode(&str);
2445
2446 // Watch for bailouts.
2447 if (failing()) return;
2448
2449 if (str.cur_bc() == Bytecodes::_monitorenter) {
2450 block->set_has_monitorenter();
2451 }
2452
2453 if (res) {
2454
2455 // We have encountered a trap. Record it in this block.
2456 block->set_trap(state->trap_bci(), state->trap_index());
2457
2458 if (CITraceTypeFlow) {
2459 tty->print_cr(">> Found trap");
2460 block->print_on(tty);
2461 }
2462
2463 // Save set of locals defined in this block
2464 block->def_locals()->add(state->def_locals());
2465
2466 // Record (no) successors.
2467 block->successors(&str, state, jsrs);
2468
2469 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2470
2471 // Discontinue interpretation of this Block.
2472 return;
2473 }
2474 }
2475
2476 GrowableArray<Block*>* successors = NULL;
2477 if (control != ciBlock::fall_through_bci) {
2478 // Check for exceptional control flow from this point.
2479 if (has_exceptions && can_trap(str)) {
2480 flow_exceptions(exceptions, exc_klasses, state);
2481 exceptions_used = true;
2482 }
2483
2484 // Fix the JsrSet to reflect effect of the bytecode.
2485 block->copy_jsrs_into(jsrs);
2486 jsrs->apply_control(this, &str, state);
2487
2488 // Find successor edges based on old state and new JsrSet.
2489 successors = block->successors(&str, state, jsrs);
2490
2491 // Apply the control changes to the state.
2492 state->apply_one_bytecode(&str);
2493 } else {
2494 // Fall through control
2495 successors = block->successors(&str, NULL, NULL);
2496 }
2497
2498 // Save set of locals defined in this block
2499 block->def_locals()->add(state->def_locals());
2500
2501 // Remove untaken exception paths
2502 if (!exceptions_used)
2503 exceptions->clear();
2504
2505 // Pass our state to successors.
2506 flow_successors(successors, state);
2507 }
2508
2509 // ------------------------------------------------------------------
2510 // ciTypeFlow::PostOrderLoops::next
2511 //
2512 // Advance to next loop tree using a postorder, left-to-right traversal.
2513 void ciTypeFlow::PostorderLoops::next() {
2514 assert(!done(), "must not be done.");
2515 if (_current->sibling() != NULL) {
2516 _current = _current->sibling();
2517 while (_current->child() != NULL) {
2518 _current = _current->child();
2519 }
2520 } else {
2521 _current = _current->parent();
2522 }
2523 }
2524
2525 // ------------------------------------------------------------------
2526 // ciTypeFlow::PreOrderLoops::next
2527 //
2528 // Advance to next loop tree using a preorder, left-to-right traversal.
2529 void ciTypeFlow::PreorderLoops::next() {
2530 assert(!done(), "must not be done.");
2531 if (_current->child() != NULL) {
2532 _current = _current->child();
2533 } else if (_current->sibling() != NULL) {
2534 _current = _current->sibling();
2535 } else {
2536 while (_current != _root && _current->sibling() == NULL) {
2537 _current = _current->parent();
2538 }
2539 if (_current == _root) {
2540 _current = NULL;
2541 assert(done(), "must be done.");
2542 } else {
2543 assert(_current->sibling() != NULL, "must be more to do");
2544 _current = _current->sibling();
2545 }
2546 }
2547 }
2548
2549 // ------------------------------------------------------------------
2550 // ciTypeFlow::Loop::sorted_merge
2551 //
2552 // Merge the branch lp into this branch, sorting on the loop head
2553 // pre_orders. Returns the leaf of the merged branch.
2554 // Child and sibling pointers will be setup later.
2555 // Sort is (looking from leaf towards the root)
2556 // descending on primary key: loop head's pre_order, and
2557 // ascending on secondary key: loop tail's pre_order.
2558 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2559 Loop* leaf = this;
2560 Loop* prev = NULL;
2561 Loop* current = leaf;
2562 while (lp != NULL) {
2563 int lp_pre_order = lp->head()->pre_order();
2564 // Find insertion point for "lp"
2565 while (current != NULL) {
2566 if (current == lp)
2567 return leaf; // Already in list
2568 if (current->head()->pre_order() < lp_pre_order)
2569 break;
2570 if (current->head()->pre_order() == lp_pre_order &&
2571 current->tail()->pre_order() > lp->tail()->pre_order()) {
2572 break;
2573 }
2574 prev = current;
2575 current = current->parent();
2576 }
2577 Loop* next_lp = lp->parent(); // Save future list of items to insert
2578 // Insert lp before current
2579 lp->set_parent(current);
2580 if (prev != NULL) {
2581 prev->set_parent(lp);
2582 } else {
2583 leaf = lp;
2584 }
2585 prev = lp; // Inserted item is new prev[ious]
2586 lp = next_lp; // Next item to insert
2587 }
2588 return leaf;
2589 }
2590
2591 // ------------------------------------------------------------------
2592 // ciTypeFlow::build_loop_tree
2593 //
2594 // Incrementally build loop tree.
2595 void ciTypeFlow::build_loop_tree(Block* blk) {
2596 assert(!blk->is_post_visited(), "precondition");
2597 Loop* innermost = NULL; // merge of loop tree branches over all successors
2598
2599 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2600 Loop* lp = NULL;
2601 Block* succ = iter.succ();
2602 if (!succ->is_post_visited()) {
2603 // Found backedge since predecessor post visited, but successor is not
2604 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2605
2606 // Create a LoopNode to mark this loop.
2607 lp = new (arena()) Loop(succ, blk);
2608 if (succ->loop() == NULL)
2609 succ->set_loop(lp);
2610 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2611
2612 } else { // Nested loop
2613 lp = succ->loop();
2614
2615 // If succ is loop head, find outer loop.
2616 while (lp != NULL && lp->head() == succ) {
2617 lp = lp->parent();
2618 }
2619 if (lp == NULL) {
2620 // Infinite loop, it's parent is the root
2621 lp = loop_tree_root();
2622 }
2623 }
2624
2625 // Check for irreducible loop.
2626 // Successor has already been visited. If the successor's loop head
2627 // has already been post-visited, then this is another entry into the loop.
2628 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2629 _has_irreducible_entry = true;
2630 lp->set_irreducible(succ);
2631 if (!succ->is_on_work_list()) {
2632 // Assume irreducible entries need more data flow
2633 add_to_work_list(succ);
2634 }
2635 Loop* plp = lp->parent();
2636 if (plp == NULL) {
2637 // This only happens for some irreducible cases. The parent
2638 // will be updated during a later pass.
2639 break;
2640 }
2641 lp = plp;
2642 }
2643
2644 // Merge loop tree branch for all successors.
2645 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2646
2647 } // end loop
2648
2649 if (innermost == NULL) {
2650 assert(blk->successors()->length() == 0, "CFG exit");
2651 blk->set_loop(loop_tree_root());
2652 } else if (innermost->head() == blk) {
2653 // If loop header, complete the tree pointers
2654 if (blk->loop() != innermost) {
2655 #ifdef ASSERT
2656 assert(blk->loop()->head() == innermost->head(), "same head");
2657 Loop* dl;
2658 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2659 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2660 #endif
2661 blk->set_loop(innermost);
2662 }
2663 innermost->def_locals()->add(blk->def_locals());
2664 Loop* l = innermost;
2665 Loop* p = l->parent();
2666 while (p && l->head() == blk) {
2667 l->set_sibling(p->child()); // Put self on parents 'next child'
2668 p->set_child(l); // Make self the first child of parent
2669 p->def_locals()->add(l->def_locals());
2670 l = p; // Walk up the parent chain
2671 p = l->parent();
2672 }
2673 } else {
2674 blk->set_loop(innermost);
2675 innermost->def_locals()->add(blk->def_locals());
2676 }
2677 }
2678
2679 // ------------------------------------------------------------------
2680 // ciTypeFlow::Loop::contains
2681 //
2682 // Returns true if lp is nested loop.
2683 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2684 assert(lp != NULL, "");
2685 if (this == lp || head() == lp->head()) return true;
2686 int depth1 = depth();
2687 int depth2 = lp->depth();
2688 if (depth1 > depth2)
2689 return false;
2690 while (depth1 < depth2) {
2691 depth2--;
2692 lp = lp->parent();
2693 }
2694 return this == lp;
2695 }
2696
2697 // ------------------------------------------------------------------
2698 // ciTypeFlow::Loop::depth
2699 //
2700 // Loop depth
2701 int ciTypeFlow::Loop::depth() const {
2702 int dp = 0;
2703 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2704 dp++;
2705 return dp;
2706 }
2707
2708 #ifndef PRODUCT
2709 // ------------------------------------------------------------------
2710 // ciTypeFlow::Loop::print
2711 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2712 for (int i = 0; i < indent; i++) st->print(" ");
2713 st->print("%d<-%d %s",
2714 is_root() ? 0 : this->head()->pre_order(),
2715 is_root() ? 0 : this->tail()->pre_order(),
2716 is_irreducible()?" irr":"");
2717 st->print(" defs: ");
2718 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2719 st->cr();
2720 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2721 ch->print(st, indent+2);
2722 }
2723 #endif
2724
2725 // ------------------------------------------------------------------
2726 // ciTypeFlow::df_flow_types
2727 //
2728 // Perform the depth first type flow analysis. Helper for flow_types.
2729 void ciTypeFlow::df_flow_types(Block* start,
2730 bool do_flow,
2731 StateVector* temp_vector,
2732 JsrSet* temp_set) {
2733 int dft_len = 100;
2734 GrowableArray<Block*> stk(dft_len);
2735
2736 ciBlock* dummy = _methodBlocks->make_dummy_block();
2737 JsrSet* root_set = new JsrSet(NULL, 0);
2738 Block* root_head = new (arena()) Block(this, dummy, root_set);
2739 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2740 root_head->set_pre_order(0);
2741 root_head->set_post_order(0);
2742 root_tail->set_pre_order(max_jint);
2743 root_tail->set_post_order(max_jint);
2744 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2745
2746 stk.push(start);
2747
2748 _next_pre_order = 0; // initialize pre_order counter
2749 _rpo_list = NULL;
2750 int next_po = 0; // initialize post_order counter
2751
2752 // Compute RPO and the control flow graph
2753 int size;
2754 while ((size = stk.length()) > 0) {
2755 Block* blk = stk.top(); // Leave node on stack
2756 if (!blk->is_visited()) {
2757 // forward arc in graph
2758 assert (!blk->has_pre_order(), "");
2759 blk->set_next_pre_order();
2760
2761 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2762 // Too many basic blocks. Bail out.
2763 // This can happen when try/finally constructs are nested to depth N,
2764 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2765 // "MaxNodeLimit / 2" is used because probably the parser will
2766 // generate at least twice that many nodes and bail out.
2767 record_failure("too many basic blocks");
2768 return;
2769 }
2770 if (do_flow) {
2771 flow_block(blk, temp_vector, temp_set);
2772 if (failing()) return; // Watch for bailouts.
2773 }
2774 } else if (!blk->is_post_visited()) {
2775 // cross or back arc
2776 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2777 Block* succ = iter.succ();
2778 if (!succ->is_visited()) {
2779 stk.push(succ);
2780 }
2781 }
2782 if (stk.length() == size) {
2783 // There were no additional children, post visit node now
2784 stk.pop(); // Remove node from stack
2785
2786 build_loop_tree(blk);
2787 blk->set_post_order(next_po++); // Assign post order
2788 prepend_to_rpo_list(blk);
2789 assert(blk->is_post_visited(), "");
2790
2791 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2792 // Assume loop heads need more data flow
2793 add_to_work_list(blk);
2794 }
2795 }
2796 } else {
2797 stk.pop(); // Remove post-visited node from stack
2798 }
2799 }
2800 }
2801
2802 // ------------------------------------------------------------------
2803 // ciTypeFlow::flow_types
2804 //
2805 // Perform the type flow analysis, creating and cloning Blocks as
2806 // necessary.
2807 void ciTypeFlow::flow_types() {
2808 ResourceMark rm;
2809 StateVector* temp_vector = new StateVector(this);
2810 JsrSet* temp_set = new JsrSet(NULL, 16);
2811
2812 // Create the method entry block.
2813 Block* start = block_at(start_bci(), temp_set);
2814
2815 // Load the initial state into it.
2816 const StateVector* start_state = get_start_state();
2817 if (failing()) return;
2818 start->meet(start_state);
2819
2820 // Depth first visit
2821 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2822
2823 if (failing()) return;
2824 assert(_rpo_list == start, "must be start");
2825
2826 // Any loops found?
2827 if (loop_tree_root()->child() != NULL &&
2828 env()->comp_level() >= CompLevel_full_optimization) {
2829 // Loop optimizations are not performed on Tier1 compiles.
2830
2831 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2832
2833 // If some loop heads were cloned, recompute postorder and loop tree
2834 if (changed) {
2835 loop_tree_root()->set_child(NULL);
2836 for (Block* blk = _rpo_list; blk != NULL;) {
2837 Block* next = blk->rpo_next();
2838 blk->df_init();
2839 blk = next;
2840 }
2841 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2842 }
2843 }
2844
2845 if (CITraceTypeFlow) {
2846 tty->print_cr("\nLoop tree");
2847 loop_tree_root()->print();
2848 }
2849
2850 // Continue flow analysis until fixed point reached
2851
2852 debug_only(int max_block = _next_pre_order;)
2853
2854 while (!work_list_empty()) {
2855 Block* blk = work_list_next();
2856 assert (blk->has_post_order(), "post order assigned above");
2857
2858 flow_block(blk, temp_vector, temp_set);
2859
2860 assert (max_block == _next_pre_order, "no new blocks");
2861 assert (!failing(), "no more bailouts");
2862 }
2863 }
2864
2865 // ------------------------------------------------------------------
2866 // ciTypeFlow::map_blocks
2867 //
2868 // Create the block map, which indexes blocks in reverse post-order.
2869 void ciTypeFlow::map_blocks() {
2870 assert(_block_map == NULL, "single initialization");
2871 int block_ct = _next_pre_order;
2872 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2873 assert(block_ct == block_count(), "");
2874
2875 Block* blk = _rpo_list;
2876 for (int m = 0; m < block_ct; m++) {
2877 int rpo = blk->rpo();
2878 assert(rpo == m, "should be sequential");
2879 _block_map[rpo] = blk;
2880 blk = blk->rpo_next();
2881 }
2882 assert(blk == NULL, "should be done");
2883
2884 for (int j = 0; j < block_ct; j++) {
2885 assert(_block_map[j] != NULL, "must not drop any blocks");
2886 Block* block = _block_map[j];
2887 // Remove dead blocks from successor lists:
2888 for (int e = 0; e <= 1; e++) {
2889 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2890 for (int k = 0; k < l->length(); k++) {
2891 Block* s = l->at(k);
2892 if (!s->has_post_order()) {
2893 if (CITraceTypeFlow) {
2894 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2895 s->print_value_on(tty);
2896 tty->cr();
2897 }
2898 l->remove(s);
2899 --k;
2900 }
2901 }
2902 }
2903 }
2904 }
2905
2906 // ------------------------------------------------------------------
2907 // ciTypeFlow::get_block_for
2908 //
2909 // Find a block with this ciBlock which has a compatible JsrSet.
2910 // If no such block exists, create it, unless the option is no_create.
2911 // If the option is create_backedge_copy, always create a fresh backedge copy.
2912 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2913 Arena* a = arena();
2914 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2915 if (blocks == NULL) {
2916 // Query only?
2917 if (option == no_create) return NULL;
2918
2919 // Allocate the growable array.
2920 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2921 _idx_to_blocklist[ciBlockIndex] = blocks;
2922 }
2923
2924 if (option != create_backedge_copy) {
2925 int len = blocks->length();
2926 for (int i = 0; i < len; i++) {
2927 Block* block = blocks->at(i);
2928 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2929 return block;
2930 }
2931 }
2932 }
2933
2934 // Query only?
2935 if (option == no_create) return NULL;
2936
2937 // We did not find a compatible block. Create one.
2938 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2939 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2940 blocks->append(new_block);
2941 return new_block;
2942 }
2943
2944 // ------------------------------------------------------------------
2945 // ciTypeFlow::backedge_copy_count
2946 //
2947 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2948 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2949
2950 if (blocks == NULL) {
2951 return 0;
2952 }
2953
2954 int count = 0;
2955 int len = blocks->length();
2956 for (int i = 0; i < len; i++) {
2957 Block* block = blocks->at(i);
2958 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2959 count++;
2960 }
2961 }
2962
2963 return count;
2964 }
2965
2966 // ------------------------------------------------------------------
2967 // ciTypeFlow::do_flow
2968 //
2969 // Perform type inference flow analysis.
2970 void ciTypeFlow::do_flow() {
2971 if (CITraceTypeFlow) {
2972 tty->print_cr("\nPerforming flow analysis on method");
2973 method()->print();
2974 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2975 tty->cr();
2976 method()->print_codes();
2977 }
2978 if (CITraceTypeFlow) {
2979 tty->print_cr("Initial CI Blocks");
2980 print_on(tty);
2981 }
2982 flow_types();
2983 // Watch for bailouts.
2984 if (failing()) {
2985 return;
2986 }
2987
2988 map_blocks();
2989
2990 if (CIPrintTypeFlow || CITraceTypeFlow) {
2991 rpo_print_on(tty);
2992 }
2993 }
2994
2995 // ------------------------------------------------------------------
2996 // ciTypeFlow::is_dominated_by
2997 //
2998 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
2999 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3000 assert(!method()->has_jsrs(), "jsrs are not supported");
3001
3002 ResourceMark rm;
3003 JsrSet* jsrs = new ciTypeFlow::JsrSet(NULL);
3004 int index = _methodBlocks->block_containing(bci)->index();
3005 int dom_index = _methodBlocks->block_containing(dom_bci)->index();
3006 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3007 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3008
3009 // Start block dominates all other blocks
3010 if (start_block()->rpo() == dom_block->rpo()) {
3011 return true;
3012 }
3013
3014 // Dominated[i] is true if block i is dominated by dom_block
3015 int num_blocks = block_count();
3016 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3017 for (int i = 0; i < num_blocks; ++i) {
3018 dominated[i] = true;
3019 }
3020 dominated[start_block()->rpo()] = false;
3021
3022 // Iterative dominator algorithm
3023 bool changed = true;
3024 while (changed) {
3025 changed = false;
3026 // Use reverse postorder iteration
3027 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3028 if (blk->is_start()) {
3029 // Ignore start block
3030 continue;
3031 }
3032 // The block is dominated if it is the dominating block
3033 // itself or if all predecessors are dominated.
3034 int index = blk->rpo();
3035 bool dom = (index == dom_block->rpo());
3036 if (!dom) {
3037 // Check if all predecessors are dominated
3038 dom = true;
3039 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3040 Block* pred = blk->predecessors()->at(i);
3041 if (!dominated[pred->rpo()]) {
3042 dom = false;
3043 break;
3044 }
3045 }
3046 }
3047 // Update dominator information
3048 if (dominated[index] != dom) {
3049 changed = true;
3050 dominated[index] = dom;
3051 }
3052 }
3053 }
3054 // block dominated by dom_block?
3055 return dominated[block->rpo()];
3056 }
3057
3058 // ------------------------------------------------------------------
3059 // ciTypeFlow::record_failure()
3060 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3061 // This is required because there is not a 1-1 relation between the ciEnv and
3062 // the TypeFlow passes within a compilation task. For example, if the compiler
3063 // is considering inlining a method, it will request a TypeFlow. If that fails,
3064 // the compilation as a whole may continue without the inlining. Some TypeFlow
3065 // requests are not optional; if they fail the requestor is responsible for
3066 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3067 void ciTypeFlow::record_failure(const char* reason) {
3068 if (env()->log() != NULL) {
3069 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3070 }
3071 if (_failure_reason == NULL) {
3072 // Record the first failure reason.
3073 _failure_reason = reason;
3074 }
3075 }
3076
3077 #ifndef PRODUCT
3078 // ------------------------------------------------------------------
3079 // ciTypeFlow::print_on
3080 void ciTypeFlow::print_on(outputStream* st) const {
3081 // Walk through CI blocks
3082 st->print_cr("********************************************************");
3083 st->print ("TypeFlow for ");
3084 method()->name()->print_symbol_on(st);
3085 int limit_bci = code_size();
3086 st->print_cr(" %d bytes", limit_bci);
3087 ciMethodBlocks *mblks = _methodBlocks;
3088 ciBlock* current = NULL;
3089 for (int bci = 0; bci < limit_bci; bci++) {
3090 ciBlock* blk = mblks->block_containing(bci);
3091 if (blk != NULL && blk != current) {
3092 current = blk;
3093 current->print_on(st);
3094
3095 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3096 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
3097
3098 if (num_blocks == 0) {
3099 st->print_cr(" No Blocks");
3100 } else {
3101 for (int i = 0; i < num_blocks; i++) {
3102 Block* block = blocks->at(i);
3103 block->print_on(st);
3104 }
3105 }
3106 st->print_cr("--------------------------------------------------------");
3107 st->cr();
3108 }
3109 }
3110 st->print_cr("********************************************************");
3111 st->cr();
3112 }
3113
3114 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3115 st->print_cr("********************************************************");
3116 st->print ("TypeFlow for ");
3117 method()->name()->print_symbol_on(st);
3118 int limit_bci = code_size();
3119 st->print_cr(" %d bytes", limit_bci);
3120 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3121 blk->print_on(st);
3122 st->print_cr("--------------------------------------------------------");
3123 st->cr();
3124 }
3125 st->print_cr("********************************************************");
3126 st->cr();
3127 }
3128 #endif