1 /*
2 * Copyright (c) 2000, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "ci/ciConstant.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciMethod.hpp"
28 #include "ci/ciMethodData.hpp"
29 #include "ci/ciObjArrayKlass.hpp"
30 #include "ci/ciStreams.hpp"
31 #include "ci/ciTypeArrayKlass.hpp"
32 #include "ci/ciTypeFlow.hpp"
33 #include "compiler/compileLog.hpp"
34 #include "interpreter/bytecode.hpp"
35 #include "interpreter/bytecodes.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "opto/compile.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "utilities/growableArray.hpp"
42
43 // ciTypeFlow::JsrSet
44 //
45 // A JsrSet represents some set of JsrRecords. This class
46 // is used to record a set of all jsr routines which we permit
47 // execution to return (ret) from.
48 //
49 // During abstract interpretation, JsrSets are used to determine
50 // whether two paths which reach a given block are unique, and
51 // should be cloned apart, or are compatible, and should merge
52 // together.
53
54 // ------------------------------------------------------------------
55 // ciTypeFlow::JsrSet::JsrSet
56
57 // Allocate growable array storage in Arena.
58 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) : _set(arena, default_len, 0, nullptr) {
59 assert(arena != nullptr, "invariant");
60 }
61
62 // Allocate growable array storage in current ResourceArea.
63 ciTypeFlow::JsrSet::JsrSet(int default_len) : _set(default_len, 0, nullptr) {}
64
65 // ------------------------------------------------------------------
66 // ciTypeFlow::JsrSet::copy_into
67 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
68 int len = size();
69 jsrs->_set.clear();
70 for (int i = 0; i < len; i++) {
71 jsrs->_set.append(_set.at(i));
72 }
73 }
74
75 // ------------------------------------------------------------------
76 // ciTypeFlow::JsrSet::is_compatible_with
77 //
78 // !!!! MISGIVINGS ABOUT THIS... disregard
79 //
80 // Is this JsrSet compatible with some other JsrSet?
81 //
82 // In set-theoretic terms, a JsrSet can be viewed as a partial function
83 // from entry addresses to return addresses. Two JsrSets A and B are
84 // compatible iff
85 //
86 // For any x,
87 // A(x) defined and B(x) defined implies A(x) == B(x)
88 //
89 // Less formally, two JsrSets are compatible when they have identical
90 // return addresses for any entry addresses they share in common.
91 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
92 // Walk through both sets in parallel. If the same entry address
93 // appears in both sets, then the return address must match for
94 // the sets to be compatible.
95 int size1 = size();
96 int size2 = other->size();
97
98 // Special case. If nothing is on the jsr stack, then there can
99 // be no ret.
100 if (size2 == 0) {
101 return true;
102 } else if (size1 != size2) {
103 return false;
104 } else {
105 for (int i = 0; i < size1; i++) {
106 JsrRecord* record1 = record_at(i);
107 JsrRecord* record2 = other->record_at(i);
108 if (record1->entry_address() != record2->entry_address() ||
109 record1->return_address() != record2->return_address()) {
110 return false;
111 }
112 }
113 return true;
114 }
115
116 #if 0
117 int pos1 = 0;
118 int pos2 = 0;
119 int size1 = size();
120 int size2 = other->size();
121 while (pos1 < size1 && pos2 < size2) {
122 JsrRecord* record1 = record_at(pos1);
123 JsrRecord* record2 = other->record_at(pos2);
124 int entry1 = record1->entry_address();
125 int entry2 = record2->entry_address();
126 if (entry1 < entry2) {
127 pos1++;
128 } else if (entry1 > entry2) {
129 pos2++;
130 } else {
131 if (record1->return_address() == record2->return_address()) {
132 pos1++;
133 pos2++;
134 } else {
135 // These two JsrSets are incompatible.
136 return false;
137 }
138 }
139 }
140 // The two JsrSets agree.
141 return true;
142 #endif
143 }
144
145 // ------------------------------------------------------------------
146 // ciTypeFlow::JsrSet::insert_jsr_record
147 //
148 // Insert the given JsrRecord into the JsrSet, maintaining the order
149 // of the set and replacing any element with the same entry address.
150 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
151 int len = size();
152 int entry = record->entry_address();
153 int pos = 0;
154 for ( ; pos < len; pos++) {
155 JsrRecord* current = record_at(pos);
156 if (entry == current->entry_address()) {
157 // Stomp over this entry.
158 _set.at_put(pos, record);
159 assert(size() == len, "must be same size");
160 return;
161 } else if (entry < current->entry_address()) {
162 break;
163 }
164 }
165
166 // Insert the record into the list.
167 JsrRecord* swap = record;
168 JsrRecord* temp = nullptr;
169 for ( ; pos < len; pos++) {
170 temp = _set.at(pos);
171 _set.at_put(pos, swap);
172 swap = temp;
173 }
174 _set.append(swap);
175 assert(size() == len+1, "must be larger");
176 }
177
178 // ------------------------------------------------------------------
179 // ciTypeFlow::JsrSet::remove_jsr_record
180 //
181 // Remove the JsrRecord with the given return address from the JsrSet.
182 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
183 int len = size();
184 for (int i = 0; i < len; i++) {
185 if (record_at(i)->return_address() == return_address) {
186 // We have found the proper entry. Remove it from the
187 // JsrSet and exit.
188 for (int j = i + 1; j < len ; j++) {
189 _set.at_put(j - 1, _set.at(j));
190 }
191 _set.trunc_to(len - 1);
192 assert(size() == len-1, "must be smaller");
193 return;
194 }
195 }
196 assert(false, "verify: returning from invalid subroutine");
197 }
198
199 // ------------------------------------------------------------------
200 // ciTypeFlow::JsrSet::apply_control
201 //
202 // Apply the effect of a control-flow bytecode on the JsrSet. The
203 // only bytecodes that modify the JsrSet are jsr and ret.
204 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
205 ciBytecodeStream* str,
206 ciTypeFlow::StateVector* state) {
207 Bytecodes::Code code = str->cur_bc();
208 if (code == Bytecodes::_jsr) {
209 JsrRecord* record =
210 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
211 insert_jsr_record(record);
212 } else if (code == Bytecodes::_jsr_w) {
213 JsrRecord* record =
214 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
215 insert_jsr_record(record);
216 } else if (code == Bytecodes::_ret) {
217 Cell local = state->local(str->get_index());
218 ciType* return_address = state->type_at(local);
219 assert(return_address->is_return_address(), "verify: wrong type");
220 if (size() == 0) {
221 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
222 // This can happen when a loop is inside a finally clause (4614060).
223 analyzer->record_failure("OSR in finally clause");
224 return;
225 }
226 remove_jsr_record(return_address->as_return_address()->bci());
227 }
228 }
229
230 #ifndef PRODUCT
231 // ------------------------------------------------------------------
232 // ciTypeFlow::JsrSet::print_on
233 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
234 st->print("{ ");
235 int num_elements = size();
236 if (num_elements > 0) {
237 int i = 0;
238 for( ; i < num_elements - 1; i++) {
239 _set.at(i)->print_on(st);
240 st->print(", ");
241 }
242 _set.at(i)->print_on(st);
243 st->print(" ");
244 }
245 st->print("}");
246 }
247 #endif
248
249 // ciTypeFlow::StateVector
250 //
251 // A StateVector summarizes the type information at some point in
252 // the program.
253
254 // ------------------------------------------------------------------
255 // ciTypeFlow::StateVector::type_meet
256 //
257 // Meet two types.
258 //
259 // The semi-lattice of types use by this analysis are modeled on those
260 // of the verifier. The lattice is as follows:
261 //
262 // top_type() >= all non-extremal types >= bottom_type
263 // and
264 // Every primitive type is comparable only with itself. The meet of
265 // reference types is determined by their kind: instance class,
266 // interface, or array class. The meet of two types of the same
267 // kind is their least common ancestor. The meet of two types of
268 // different kinds is always java.lang.Object.
269 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
270 assert(t1 != t2, "checked in caller");
271 if (t1->equals(top_type())) {
272 return t2;
273 } else if (t2->equals(top_type())) {
274 return t1;
275 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
276 // Special case null_type. null_type meet any reference type T
277 // is T. null_type meet null_type is null_type.
278 if (t1->equals(null_type())) {
279 if (!t2->is_primitive_type() || t2->equals(null_type())) {
280 return t2;
281 }
282 } else if (t2->equals(null_type())) {
283 if (!t1->is_primitive_type()) {
284 return t1;
285 }
286 }
287
288 // At least one of the two types is a non-top primitive type.
289 // The other type is not equal to it. Fall to bottom.
290 return bottom_type();
291 } else {
292 // Both types are non-top non-primitive types. That is,
293 // both types are either instanceKlasses or arrayKlasses.
294 ciKlass* object_klass = analyzer->env()->Object_klass();
295 ciKlass* k1 = t1->as_klass();
296 ciKlass* k2 = t2->as_klass();
297 if (k1->equals(object_klass) || k2->equals(object_klass)) {
298 return object_klass;
299 } else if (!k1->is_loaded() || !k2->is_loaded()) {
300 // Unloaded classes fall to java.lang.Object at a merge.
301 return object_klass;
302 } else if (k1->is_interface() != k2->is_interface()) {
303 // When an interface meets a non-interface, we get Object;
304 // This is what the verifier does.
305 return object_klass;
306 } else if (k1->is_array_klass() || k2->is_array_klass()) {
307 // When an array meets a non-array, we get Object.
308 // When objArray meets typeArray, we also get Object.
309 // And when typeArray meets different typeArray, we again get Object.
310 // But when objArray meets objArray, we look carefully at element types.
311 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
312 // Meet the element types, then construct the corresponding array type.
313 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
314 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
315 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
316 // Do an easy shortcut if one type is a super of the other.
317 if (elem == elem1) {
318 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
319 return k1;
320 } else if (elem == elem2) {
321 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
322 return k2;
323 } else {
324 return ciObjArrayKlass::make(elem);
325 }
326 } else {
327 return object_klass;
328 }
329 } else {
330 // Must be two plain old instance klasses.
331 assert(k1->is_instance_klass(), "previous cases handle non-instances");
332 assert(k2->is_instance_klass(), "previous cases handle non-instances");
333 return k1->least_common_ancestor(k2);
334 }
335 }
336 }
337
338
339 // ------------------------------------------------------------------
340 // ciTypeFlow::StateVector::StateVector
341 //
342 // Build a new state vector
343 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
344 _outer = analyzer;
345 _stack_size = -1;
346 _monitor_count = -1;
347 // Allocate the _types array
348 int max_cells = analyzer->max_cells();
349 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
350 for (int i=0; i<max_cells; i++) {
351 _types[i] = top_type();
352 }
353 _trap_bci = -1;
354 _trap_index = 0;
355 _def_locals.clear();
356 }
357
358
359 // ------------------------------------------------------------------
360 // ciTypeFlow::get_start_state
361 //
362 // Set this vector to the method entry state.
363 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
364 StateVector* state = new StateVector(this);
365 if (is_osr_flow()) {
366 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
367 if (non_osr_flow->failing()) {
368 record_failure(non_osr_flow->failure_reason());
369 return nullptr;
370 }
371 JsrSet* jsrs = new JsrSet(4);
372 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
373 if (non_osr_block == nullptr) {
374 record_failure("cannot reach OSR point");
375 return nullptr;
376 }
377 // load up the non-OSR state at this point
378 non_osr_block->copy_state_into(state);
379 int non_osr_start = non_osr_block->start();
380 if (non_osr_start != start_bci()) {
381 // must flow forward from it
382 if (CITraceTypeFlow) {
383 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
384 }
385 Block* block = block_at(non_osr_start, jsrs);
386 assert(block->limit() == start_bci(), "must flow forward to start");
387 flow_block(block, state, jsrs);
388 }
389 return state;
390 // Note: The code below would be an incorrect for an OSR flow,
391 // even if it were possible for an OSR entry point to be at bci zero.
392 }
393 // "Push" the method signature into the first few locals.
394 state->set_stack_size(-max_locals());
395 if (!method()->is_static()) {
396 state->push(method()->holder());
397 assert(state->tos() == state->local(0), "");
398 }
399 for (ciSignatureStream str(method()->signature());
400 !str.at_return_type();
401 str.next()) {
402 state->push_translate(str.type());
403 }
404 // Set the rest of the locals to bottom.
405 assert(state->stack_size() <= 0, "stack size should not be strictly positive");
406 while (state->stack_size() < 0) {
407 state->push(state->bottom_type());
408 }
409 // Lock an object, if necessary.
410 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
411 return state;
412 }
413
414 // ------------------------------------------------------------------
415 // ciTypeFlow::StateVector::copy_into
416 //
417 // Copy our value into some other StateVector
418 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
419 const {
420 copy->set_stack_size(stack_size());
421 copy->set_monitor_count(monitor_count());
422 Cell limit = limit_cell();
423 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
424 copy->set_type_at(c, type_at(c));
425 }
426 }
427
428 // ------------------------------------------------------------------
429 // ciTypeFlow::StateVector::meet
430 //
431 // Meets this StateVector with another, destructively modifying this
432 // one. Returns true if any modification takes place.
433 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
434 if (monitor_count() == -1) {
435 set_monitor_count(incoming->monitor_count());
436 }
437 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
438
439 if (stack_size() == -1) {
440 set_stack_size(incoming->stack_size());
441 Cell limit = limit_cell();
442 #ifdef ASSERT
443 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
444 assert(type_at(c) == top_type(), "");
445 } }
446 #endif
447 // Make a simple copy of the incoming state.
448 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
449 set_type_at(c, incoming->type_at(c));
450 }
451 return true; // it is always different the first time
452 }
453 #ifdef ASSERT
454 if (stack_size() != incoming->stack_size()) {
455 _outer->method()->print_codes();
456 tty->print_cr("!!!! Stack size conflict");
457 tty->print_cr("Current state:");
458 print_on(tty);
459 tty->print_cr("Incoming state:");
460 ((StateVector*)incoming)->print_on(tty);
461 }
462 #endif
463 assert(stack_size() == incoming->stack_size(), "sanity");
464
465 bool different = false;
466 Cell limit = limit_cell();
467 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
468 ciType* t1 = type_at(c);
469 ciType* t2 = incoming->type_at(c);
470 if (!t1->equals(t2)) {
471 ciType* new_type = type_meet(t1, t2);
472 if (!t1->equals(new_type)) {
473 set_type_at(c, new_type);
474 different = true;
475 }
476 }
477 }
478 return different;
479 }
480
481 // ------------------------------------------------------------------
482 // ciTypeFlow::StateVector::meet_exception
483 //
484 // Meets this StateVector with another, destructively modifying this
485 // one. The incoming state is coming via an exception. Returns true
486 // if any modification takes place.
487 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
488 const ciTypeFlow::StateVector* incoming) {
489 if (monitor_count() == -1) {
490 set_monitor_count(incoming->monitor_count());
491 }
492 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
493
494 if (stack_size() == -1) {
495 set_stack_size(1);
496 }
497
498 assert(stack_size() == 1, "must have one-element stack");
499
500 bool different = false;
501
502 // Meet locals from incoming array.
503 Cell limit = local_limit_cell();
504 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
505 ciType* t1 = type_at(c);
506 ciType* t2 = incoming->type_at(c);
507 if (!t1->equals(t2)) {
508 ciType* new_type = type_meet(t1, t2);
509 if (!t1->equals(new_type)) {
510 set_type_at(c, new_type);
511 different = true;
512 }
513 }
514 }
515
516 // Handle stack separately. When an exception occurs, the
517 // only stack entry is the exception instance.
518 ciType* tos_type = type_at_tos();
519 if (!tos_type->equals(exc)) {
520 ciType* new_type = type_meet(tos_type, exc);
521 if (!tos_type->equals(new_type)) {
522 set_type_at_tos(new_type);
523 different = true;
524 }
525 }
526
527 return different;
528 }
529
530 // ------------------------------------------------------------------
531 // ciTypeFlow::StateVector::push_translate
532 void ciTypeFlow::StateVector::push_translate(ciType* type) {
533 BasicType basic_type = type->basic_type();
534 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
535 basic_type == T_BYTE || basic_type == T_SHORT) {
536 push_int();
537 } else {
538 push(type);
539 if (type->is_two_word()) {
540 push(half_type(type));
541 }
542 }
543 }
544
545 // ------------------------------------------------------------------
546 // ciTypeFlow::StateVector::do_aaload
547 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
548 pop_int();
549 ciObjArrayKlass* array_klass = pop_objArray();
550 if (array_klass == nullptr) {
551 // Did aaload on a null reference; push a null and ignore the exception.
552 // This instruction will never continue normally. All we have to do
553 // is report a value that will meet correctly with any downstream
554 // reference types on paths that will truly be executed. This null type
555 // meets with any reference type to yield that same reference type.
556 // (The compiler will generate an unconditional exception here.)
557 push(null_type());
558 return;
559 }
560 if (!array_klass->is_loaded()) {
561 // Only fails for some -Xcomp runs
562 trap(str, array_klass,
563 Deoptimization::make_trap_request
564 (Deoptimization::Reason_unloaded,
565 Deoptimization::Action_reinterpret));
566 return;
567 }
568 ciKlass* element_klass = array_klass->element_klass();
569 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
570 Untested("unloaded array element class in ciTypeFlow");
571 trap(str, element_klass,
572 Deoptimization::make_trap_request
573 (Deoptimization::Reason_unloaded,
574 Deoptimization::Action_reinterpret));
575 } else {
576 push_object(element_klass);
577 }
578 }
579
580
581 // ------------------------------------------------------------------
582 // ciTypeFlow::StateVector::do_checkcast
583 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
584 bool will_link;
585 ciKlass* klass = str->get_klass(will_link);
586 if (!will_link) {
587 // VM's interpreter will not load 'klass' if object is null.
588 // Type flow after this block may still be needed in two situations:
589 // 1) C2 uses do_null_assert() and continues compilation for later blocks
590 // 2) C2 does an OSR compile in a later block (see bug 4778368).
591 pop_object();
592 do_null_assert(klass);
593 } else {
594 pop_object();
595 push_object(klass);
596 }
597 }
598
599 // ------------------------------------------------------------------
600 // ciTypeFlow::StateVector::do_getfield
601 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
602 // could add assert here for type of object.
603 pop_object();
604 do_getstatic(str);
605 }
606
607 // ------------------------------------------------------------------
608 // ciTypeFlow::StateVector::do_getstatic
609 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
610 bool will_link;
611 ciField* field = str->get_field(will_link);
612 if (!will_link) {
613 trap(str, field->holder(), str->get_field_holder_index());
614 } else {
615 ciType* field_type = field->type();
616 if (!field_type->is_loaded()) {
617 // Normally, we need the field's type to be loaded if we are to
618 // do anything interesting with its value.
619 // We used to do this: trap(str, str->get_field_signature_index());
620 //
621 // There is one good reason not to trap here. Execution can
622 // get past this "getfield" or "getstatic" if the value of
623 // the field is null. As long as the value is null, the class
624 // does not need to be loaded! The compiler must assume that
625 // the value of the unloaded class reference is null; if the code
626 // ever sees a non-null value, loading has occurred.
627 //
628 // This actually happens often enough to be annoying. If the
629 // compiler throws an uncommon trap at this bytecode, you can
630 // get an endless loop of recompilations, when all the code
631 // needs to do is load a series of null values. Also, a trap
632 // here can make an OSR entry point unreachable, triggering the
633 // assert on non_osr_block in ciTypeFlow::get_start_state.
634 // (See bug 4379915.)
635 do_null_assert(field_type->as_klass());
636 } else {
637 push_translate(field_type);
638 }
639 }
640 }
641
642 // ------------------------------------------------------------------
643 // ciTypeFlow::StateVector::do_invoke
644 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
645 bool has_receiver) {
646 bool will_link;
647 ciSignature* declared_signature = nullptr;
648 ciMethod* callee = str->get_method(will_link, &declared_signature);
649 assert(declared_signature != nullptr, "cannot be null");
650 if (!will_link) {
651 // We weren't able to find the method.
652 if (str->cur_bc() == Bytecodes::_invokedynamic) {
653 trap(str, nullptr,
654 Deoptimization::make_trap_request
655 (Deoptimization::Reason_uninitialized,
656 Deoptimization::Action_reinterpret));
657 } else {
658 ciKlass* unloaded_holder = callee->holder();
659 trap(str, unloaded_holder, str->get_method_holder_index());
660 }
661 } else {
662 // We are using the declared signature here because it might be
663 // different from the callee signature (Cf. invokedynamic and
664 // invokehandle).
665 ciSignatureStream sigstr(declared_signature);
666 const int arg_size = declared_signature->size();
667 const int stack_base = stack_size() - arg_size;
668 int i = 0;
669 for( ; !sigstr.at_return_type(); sigstr.next()) {
670 ciType* type = sigstr.type();
671 ciType* stack_type = type_at(stack(stack_base + i++));
672 // Do I want to check this type?
673 // assert(stack_type->is_subtype_of(type), "bad type for field value");
674 if (type->is_two_word()) {
675 ciType* stack_type2 = type_at(stack(stack_base + i++));
676 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
677 }
678 }
679 assert(arg_size == i, "must match");
680 for (int j = 0; j < arg_size; j++) {
681 pop();
682 }
683 if (has_receiver) {
684 // Check this?
685 pop_object();
686 }
687 assert(!sigstr.is_done(), "must have return type");
688 ciType* return_type = sigstr.type();
689 if (!return_type->is_void()) {
690 if (!return_type->is_loaded()) {
691 // As in do_getstatic(), generally speaking, we need the return type to
692 // be loaded if we are to do anything interesting with its value.
693 // We used to do this: trap(str, str->get_method_signature_index());
694 //
695 // We do not trap here since execution can get past this invoke if
696 // the return value is null. As long as the value is null, the class
697 // does not need to be loaded! The compiler must assume that
698 // the value of the unloaded class reference is null; if the code
699 // ever sees a non-null value, loading has occurred.
700 //
701 // See do_getstatic() for similar explanation, as well as bug 4684993.
702 do_null_assert(return_type->as_klass());
703 } else {
704 push_translate(return_type);
705 }
706 }
707 }
708 }
709
710 // ------------------------------------------------------------------
711 // ciTypeFlow::StateVector::do_jsr
712 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
713 push(ciReturnAddress::make(str->next_bci()));
714 }
715
716 // ------------------------------------------------------------------
717 // ciTypeFlow::StateVector::do_ldc
718 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
719 if (str->is_in_error()) {
720 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unhandled,
721 Deoptimization::Action_none));
722 return;
723 }
724 ciConstant con = str->get_constant();
725 if (con.is_valid()) {
726 int cp_index = str->get_constant_pool_index();
727 if (!con.is_loaded()) {
728 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unloaded,
729 Deoptimization::Action_reinterpret,
730 cp_index));
731 return;
732 }
733 BasicType basic_type = str->get_basic_type_for_constant_at(cp_index);
734 if (is_reference_type(basic_type)) {
735 ciObject* obj = con.as_object();
736 if (obj->is_null_object()) {
737 push_null();
738 } else {
739 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
740 push_object(obj->klass());
741 }
742 } else {
743 assert(basic_type == con.basic_type() || con.basic_type() == T_OBJECT,
744 "not a boxed form: %s vs %s", type2name(basic_type), type2name(con.basic_type()));
745 push_translate(ciType::make(basic_type));
746 }
747 } else {
748 // OutOfMemoryError in the CI while loading a String constant.
749 push_null();
750 outer()->record_failure("ldc did not link");
751 }
752 }
753
754 // ------------------------------------------------------------------
755 // ciTypeFlow::StateVector::do_multianewarray
756 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
757 int dimensions = str->get_dimensions();
758 bool will_link;
759 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
760 if (!will_link) {
761 trap(str, array_klass, str->get_klass_index());
762 } else {
763 for (int i = 0; i < dimensions; i++) {
764 pop_int();
765 }
766 push_object(array_klass);
767 }
768 }
769
770 // ------------------------------------------------------------------
771 // ciTypeFlow::StateVector::do_new
772 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
773 bool will_link;
774 ciKlass* klass = str->get_klass(will_link);
775 if (!will_link || str->is_unresolved_klass()) {
776 trap(str, klass, str->get_klass_index());
777 } else {
778 push_object(klass);
779 }
780 }
781
782 // ------------------------------------------------------------------
783 // ciTypeFlow::StateVector::do_newarray
784 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
785 pop_int();
786 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
787 push_object(klass);
788 }
789
790 // ------------------------------------------------------------------
791 // ciTypeFlow::StateVector::do_putfield
792 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
793 do_putstatic(str);
794 if (_trap_bci != -1) return; // unloaded field holder, etc.
795 // could add assert here for type of object.
796 pop_object();
797 }
798
799 // ------------------------------------------------------------------
800 // ciTypeFlow::StateVector::do_putstatic
801 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
802 bool will_link;
803 ciField* field = str->get_field(will_link);
804 if (!will_link) {
805 trap(str, field->holder(), str->get_field_holder_index());
806 } else {
807 ciType* field_type = field->type();
808 ciType* type = pop_value();
809 // Do I want to check this type?
810 // assert(type->is_subtype_of(field_type), "bad type for field value");
811 if (field_type->is_two_word()) {
812 ciType* type2 = pop_value();
813 assert(type2->is_two_word(), "must be 2nd half");
814 assert(type == half_type(type2), "must be 2nd half");
815 }
816 }
817 }
818
819 // ------------------------------------------------------------------
820 // ciTypeFlow::StateVector::do_ret
821 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
822 Cell index = local(str->get_index());
823
824 ciType* address = type_at(index);
825 assert(address->is_return_address(), "bad return address");
826 set_type_at(index, bottom_type());
827 }
828
829 // ------------------------------------------------------------------
830 // ciTypeFlow::StateVector::trap
831 //
832 // Stop interpretation of this path with a trap.
833 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
834 _trap_bci = str->cur_bci();
835 _trap_index = index;
836
837 // Log information about this trap:
838 CompileLog* log = outer()->env()->log();
839 if (log != nullptr) {
840 int mid = log->identify(outer()->method());
841 int kid = (klass == nullptr)? -1: log->identify(klass);
842 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
843 char buf[100];
844 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
845 index));
846 if (kid >= 0)
847 log->print(" klass='%d'", kid);
848 log->end_elem();
849 }
850 }
851
852 // ------------------------------------------------------------------
853 // ciTypeFlow::StateVector::do_null_assert
854 // Corresponds to graphKit::do_null_assert.
855 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
856 if (unloaded_klass->is_loaded()) {
857 // We failed to link, but we can still compute with this class,
858 // since it is loaded somewhere. The compiler will uncommon_trap
859 // if the object is not null, but the typeflow pass can not assume
860 // that the object will be null, otherwise it may incorrectly tell
861 // the parser that an object is known to be null. 4761344, 4807707
862 push_object(unloaded_klass);
863 } else {
864 // The class is not loaded anywhere. It is safe to model the
865 // null in the typestates, because we can compile in a null check
866 // which will deoptimize us if someone manages to load the
867 // class later.
868 push_null();
869 }
870 }
871
872
873 // ------------------------------------------------------------------
874 // ciTypeFlow::StateVector::apply_one_bytecode
875 //
876 // Apply the effect of one bytecode to this StateVector
877 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
878 _trap_bci = -1;
879 _trap_index = 0;
880
881 if (CITraceTypeFlow) {
882 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
883 Bytecodes::name(str->cur_bc()));
884 }
885
886 switch(str->cur_bc()) {
887 case Bytecodes::_aaload: do_aaload(str); break;
888
889 case Bytecodes::_aastore:
890 {
891 pop_object();
892 pop_int();
893 pop_objArray();
894 break;
895 }
896 case Bytecodes::_aconst_null:
897 {
898 push_null();
899 break;
900 }
901 case Bytecodes::_aload: load_local_object(str->get_index()); break;
902 case Bytecodes::_aload_0: load_local_object(0); break;
903 case Bytecodes::_aload_1: load_local_object(1); break;
904 case Bytecodes::_aload_2: load_local_object(2); break;
905 case Bytecodes::_aload_3: load_local_object(3); break;
906
907 case Bytecodes::_anewarray:
908 {
909 pop_int();
910 bool will_link;
911 ciKlass* element_klass = str->get_klass(will_link);
912 if (!will_link) {
913 trap(str, element_klass, str->get_klass_index());
914 } else {
915 push_object(ciObjArrayKlass::make(element_klass));
916 }
917 break;
918 }
919 case Bytecodes::_areturn:
920 case Bytecodes::_ifnonnull:
921 case Bytecodes::_ifnull:
922 {
923 pop_object();
924 break;
925 }
926 case Bytecodes::_monitorenter:
927 {
928 pop_object();
929 set_monitor_count(monitor_count() + 1);
930 break;
931 }
932 case Bytecodes::_monitorexit:
933 {
934 pop_object();
935 assert(monitor_count() > 0, "must be a monitor to exit from");
936 set_monitor_count(monitor_count() - 1);
937 break;
938 }
939 case Bytecodes::_arraylength:
940 {
941 pop_array();
942 push_int();
943 break;
944 }
945 case Bytecodes::_astore: store_local_object(str->get_index()); break;
946 case Bytecodes::_astore_0: store_local_object(0); break;
947 case Bytecodes::_astore_1: store_local_object(1); break;
948 case Bytecodes::_astore_2: store_local_object(2); break;
949 case Bytecodes::_astore_3: store_local_object(3); break;
950
951 case Bytecodes::_athrow:
952 {
953 NEEDS_CLEANUP;
954 pop_object();
955 break;
956 }
957 case Bytecodes::_baload:
958 case Bytecodes::_caload:
959 case Bytecodes::_iaload:
960 case Bytecodes::_saload:
961 {
962 pop_int();
963 ciTypeArrayKlass* array_klass = pop_typeArray();
964 // Put assert here for right type?
965 push_int();
966 break;
967 }
968 case Bytecodes::_bastore:
969 case Bytecodes::_castore:
970 case Bytecodes::_iastore:
971 case Bytecodes::_sastore:
972 {
973 pop_int();
974 pop_int();
975 pop_typeArray();
976 // assert here?
977 break;
978 }
979 case Bytecodes::_bipush:
980 case Bytecodes::_iconst_m1:
981 case Bytecodes::_iconst_0:
982 case Bytecodes::_iconst_1:
983 case Bytecodes::_iconst_2:
984 case Bytecodes::_iconst_3:
985 case Bytecodes::_iconst_4:
986 case Bytecodes::_iconst_5:
987 case Bytecodes::_sipush:
988 {
989 push_int();
990 break;
991 }
992 case Bytecodes::_checkcast: do_checkcast(str); break;
993
994 case Bytecodes::_d2f:
995 {
996 pop_double();
997 push_float();
998 break;
999 }
1000 case Bytecodes::_d2i:
1001 {
1002 pop_double();
1003 push_int();
1004 break;
1005 }
1006 case Bytecodes::_d2l:
1007 {
1008 pop_double();
1009 push_long();
1010 break;
1011 }
1012 case Bytecodes::_dadd:
1013 case Bytecodes::_ddiv:
1014 case Bytecodes::_dmul:
1015 case Bytecodes::_drem:
1016 case Bytecodes::_dsub:
1017 {
1018 pop_double();
1019 pop_double();
1020 push_double();
1021 break;
1022 }
1023 case Bytecodes::_daload:
1024 {
1025 pop_int();
1026 ciTypeArrayKlass* array_klass = pop_typeArray();
1027 // Put assert here for right type?
1028 push_double();
1029 break;
1030 }
1031 case Bytecodes::_dastore:
1032 {
1033 pop_double();
1034 pop_int();
1035 pop_typeArray();
1036 // assert here?
1037 break;
1038 }
1039 case Bytecodes::_dcmpg:
1040 case Bytecodes::_dcmpl:
1041 {
1042 pop_double();
1043 pop_double();
1044 push_int();
1045 break;
1046 }
1047 case Bytecodes::_dconst_0:
1048 case Bytecodes::_dconst_1:
1049 {
1050 push_double();
1051 break;
1052 }
1053 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1054 case Bytecodes::_dload_0: load_local_double(0); break;
1055 case Bytecodes::_dload_1: load_local_double(1); break;
1056 case Bytecodes::_dload_2: load_local_double(2); break;
1057 case Bytecodes::_dload_3: load_local_double(3); break;
1058
1059 case Bytecodes::_dneg:
1060 {
1061 pop_double();
1062 push_double();
1063 break;
1064 }
1065 case Bytecodes::_dreturn:
1066 {
1067 pop_double();
1068 break;
1069 }
1070 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1071 case Bytecodes::_dstore_0: store_local_double(0); break;
1072 case Bytecodes::_dstore_1: store_local_double(1); break;
1073 case Bytecodes::_dstore_2: store_local_double(2); break;
1074 case Bytecodes::_dstore_3: store_local_double(3); break;
1075
1076 case Bytecodes::_dup:
1077 {
1078 push(type_at_tos());
1079 break;
1080 }
1081 case Bytecodes::_dup_x1:
1082 {
1083 ciType* value1 = pop_value();
1084 ciType* value2 = pop_value();
1085 push(value1);
1086 push(value2);
1087 push(value1);
1088 break;
1089 }
1090 case Bytecodes::_dup_x2:
1091 {
1092 ciType* value1 = pop_value();
1093 ciType* value2 = pop_value();
1094 ciType* value3 = pop_value();
1095 push(value1);
1096 push(value3);
1097 push(value2);
1098 push(value1);
1099 break;
1100 }
1101 case Bytecodes::_dup2:
1102 {
1103 ciType* value1 = pop_value();
1104 ciType* value2 = pop_value();
1105 push(value2);
1106 push(value1);
1107 push(value2);
1108 push(value1);
1109 break;
1110 }
1111 case Bytecodes::_dup2_x1:
1112 {
1113 ciType* value1 = pop_value();
1114 ciType* value2 = pop_value();
1115 ciType* value3 = pop_value();
1116 push(value2);
1117 push(value1);
1118 push(value3);
1119 push(value2);
1120 push(value1);
1121 break;
1122 }
1123 case Bytecodes::_dup2_x2:
1124 {
1125 ciType* value1 = pop_value();
1126 ciType* value2 = pop_value();
1127 ciType* value3 = pop_value();
1128 ciType* value4 = pop_value();
1129 push(value2);
1130 push(value1);
1131 push(value4);
1132 push(value3);
1133 push(value2);
1134 push(value1);
1135 break;
1136 }
1137 case Bytecodes::_f2d:
1138 {
1139 pop_float();
1140 push_double();
1141 break;
1142 }
1143 case Bytecodes::_f2i:
1144 {
1145 pop_float();
1146 push_int();
1147 break;
1148 }
1149 case Bytecodes::_f2l:
1150 {
1151 pop_float();
1152 push_long();
1153 break;
1154 }
1155 case Bytecodes::_fadd:
1156 case Bytecodes::_fdiv:
1157 case Bytecodes::_fmul:
1158 case Bytecodes::_frem:
1159 case Bytecodes::_fsub:
1160 {
1161 pop_float();
1162 pop_float();
1163 push_float();
1164 break;
1165 }
1166 case Bytecodes::_faload:
1167 {
1168 pop_int();
1169 ciTypeArrayKlass* array_klass = pop_typeArray();
1170 // Put assert here.
1171 push_float();
1172 break;
1173 }
1174 case Bytecodes::_fastore:
1175 {
1176 pop_float();
1177 pop_int();
1178 ciTypeArrayKlass* array_klass = pop_typeArray();
1179 // Put assert here.
1180 break;
1181 }
1182 case Bytecodes::_fcmpg:
1183 case Bytecodes::_fcmpl:
1184 {
1185 pop_float();
1186 pop_float();
1187 push_int();
1188 break;
1189 }
1190 case Bytecodes::_fconst_0:
1191 case Bytecodes::_fconst_1:
1192 case Bytecodes::_fconst_2:
1193 {
1194 push_float();
1195 break;
1196 }
1197 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1198 case Bytecodes::_fload_0: load_local_float(0); break;
1199 case Bytecodes::_fload_1: load_local_float(1); break;
1200 case Bytecodes::_fload_2: load_local_float(2); break;
1201 case Bytecodes::_fload_3: load_local_float(3); break;
1202
1203 case Bytecodes::_fneg:
1204 {
1205 pop_float();
1206 push_float();
1207 break;
1208 }
1209 case Bytecodes::_freturn:
1210 {
1211 pop_float();
1212 break;
1213 }
1214 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1215 case Bytecodes::_fstore_0: store_local_float(0); break;
1216 case Bytecodes::_fstore_1: store_local_float(1); break;
1217 case Bytecodes::_fstore_2: store_local_float(2); break;
1218 case Bytecodes::_fstore_3: store_local_float(3); break;
1219
1220 case Bytecodes::_getfield: do_getfield(str); break;
1221 case Bytecodes::_getstatic: do_getstatic(str); break;
1222
1223 case Bytecodes::_goto:
1224 case Bytecodes::_goto_w:
1225 case Bytecodes::_nop:
1226 case Bytecodes::_return:
1227 {
1228 // do nothing.
1229 break;
1230 }
1231 case Bytecodes::_i2b:
1232 case Bytecodes::_i2c:
1233 case Bytecodes::_i2s:
1234 case Bytecodes::_ineg:
1235 {
1236 pop_int();
1237 push_int();
1238 break;
1239 }
1240 case Bytecodes::_i2d:
1241 {
1242 pop_int();
1243 push_double();
1244 break;
1245 }
1246 case Bytecodes::_i2f:
1247 {
1248 pop_int();
1249 push_float();
1250 break;
1251 }
1252 case Bytecodes::_i2l:
1253 {
1254 pop_int();
1255 push_long();
1256 break;
1257 }
1258 case Bytecodes::_iadd:
1259 case Bytecodes::_iand:
1260 case Bytecodes::_idiv:
1261 case Bytecodes::_imul:
1262 case Bytecodes::_ior:
1263 case Bytecodes::_irem:
1264 case Bytecodes::_ishl:
1265 case Bytecodes::_ishr:
1266 case Bytecodes::_isub:
1267 case Bytecodes::_iushr:
1268 case Bytecodes::_ixor:
1269 {
1270 pop_int();
1271 pop_int();
1272 push_int();
1273 break;
1274 }
1275 case Bytecodes::_if_acmpeq:
1276 case Bytecodes::_if_acmpne:
1277 {
1278 pop_object();
1279 pop_object();
1280 break;
1281 }
1282 case Bytecodes::_if_icmpeq:
1283 case Bytecodes::_if_icmpge:
1284 case Bytecodes::_if_icmpgt:
1285 case Bytecodes::_if_icmple:
1286 case Bytecodes::_if_icmplt:
1287 case Bytecodes::_if_icmpne:
1288 {
1289 pop_int();
1290 pop_int();
1291 break;
1292 }
1293 case Bytecodes::_ifeq:
1294 case Bytecodes::_ifle:
1295 case Bytecodes::_iflt:
1296 case Bytecodes::_ifge:
1297 case Bytecodes::_ifgt:
1298 case Bytecodes::_ifne:
1299 case Bytecodes::_ireturn:
1300 case Bytecodes::_lookupswitch:
1301 case Bytecodes::_tableswitch:
1302 {
1303 pop_int();
1304 break;
1305 }
1306 case Bytecodes::_iinc:
1307 {
1308 int lnum = str->get_index();
1309 check_int(local(lnum));
1310 store_to_local(lnum);
1311 break;
1312 }
1313 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1314 case Bytecodes::_iload_0: load_local_int(0); break;
1315 case Bytecodes::_iload_1: load_local_int(1); break;
1316 case Bytecodes::_iload_2: load_local_int(2); break;
1317 case Bytecodes::_iload_3: load_local_int(3); break;
1318
1319 case Bytecodes::_instanceof:
1320 {
1321 // Check for uncommon trap:
1322 do_checkcast(str);
1323 pop_object();
1324 push_int();
1325 break;
1326 }
1327 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1328 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1329 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1330 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1331 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1332
1333 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1334 case Bytecodes::_istore_0: store_local_int(0); break;
1335 case Bytecodes::_istore_1: store_local_int(1); break;
1336 case Bytecodes::_istore_2: store_local_int(2); break;
1337 case Bytecodes::_istore_3: store_local_int(3); break;
1338
1339 case Bytecodes::_jsr:
1340 case Bytecodes::_jsr_w: do_jsr(str); break;
1341
1342 case Bytecodes::_l2d:
1343 {
1344 pop_long();
1345 push_double();
1346 break;
1347 }
1348 case Bytecodes::_l2f:
1349 {
1350 pop_long();
1351 push_float();
1352 break;
1353 }
1354 case Bytecodes::_l2i:
1355 {
1356 pop_long();
1357 push_int();
1358 break;
1359 }
1360 case Bytecodes::_ladd:
1361 case Bytecodes::_land:
1362 case Bytecodes::_ldiv:
1363 case Bytecodes::_lmul:
1364 case Bytecodes::_lor:
1365 case Bytecodes::_lrem:
1366 case Bytecodes::_lsub:
1367 case Bytecodes::_lxor:
1368 {
1369 pop_long();
1370 pop_long();
1371 push_long();
1372 break;
1373 }
1374 case Bytecodes::_laload:
1375 {
1376 pop_int();
1377 ciTypeArrayKlass* array_klass = pop_typeArray();
1378 // Put assert here for right type?
1379 push_long();
1380 break;
1381 }
1382 case Bytecodes::_lastore:
1383 {
1384 pop_long();
1385 pop_int();
1386 pop_typeArray();
1387 // assert here?
1388 break;
1389 }
1390 case Bytecodes::_lcmp:
1391 {
1392 pop_long();
1393 pop_long();
1394 push_int();
1395 break;
1396 }
1397 case Bytecodes::_lconst_0:
1398 case Bytecodes::_lconst_1:
1399 {
1400 push_long();
1401 break;
1402 }
1403 case Bytecodes::_ldc:
1404 case Bytecodes::_ldc_w:
1405 case Bytecodes::_ldc2_w:
1406 {
1407 do_ldc(str);
1408 break;
1409 }
1410
1411 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1412 case Bytecodes::_lload_0: load_local_long(0); break;
1413 case Bytecodes::_lload_1: load_local_long(1); break;
1414 case Bytecodes::_lload_2: load_local_long(2); break;
1415 case Bytecodes::_lload_3: load_local_long(3); break;
1416
1417 case Bytecodes::_lneg:
1418 {
1419 pop_long();
1420 push_long();
1421 break;
1422 }
1423 case Bytecodes::_lreturn:
1424 {
1425 pop_long();
1426 break;
1427 }
1428 case Bytecodes::_lshl:
1429 case Bytecodes::_lshr:
1430 case Bytecodes::_lushr:
1431 {
1432 pop_int();
1433 pop_long();
1434 push_long();
1435 break;
1436 }
1437 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1438 case Bytecodes::_lstore_0: store_local_long(0); break;
1439 case Bytecodes::_lstore_1: store_local_long(1); break;
1440 case Bytecodes::_lstore_2: store_local_long(2); break;
1441 case Bytecodes::_lstore_3: store_local_long(3); break;
1442
1443 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1444
1445 case Bytecodes::_new: do_new(str); break;
1446
1447 case Bytecodes::_newarray: do_newarray(str); break;
1448
1449 case Bytecodes::_pop:
1450 {
1451 pop();
1452 break;
1453 }
1454 case Bytecodes::_pop2:
1455 {
1456 pop();
1457 pop();
1458 break;
1459 }
1460
1461 case Bytecodes::_putfield: do_putfield(str); break;
1462 case Bytecodes::_putstatic: do_putstatic(str); break;
1463
1464 case Bytecodes::_ret: do_ret(str); break;
1465
1466 case Bytecodes::_swap:
1467 {
1468 ciType* value1 = pop_value();
1469 ciType* value2 = pop_value();
1470 push(value1);
1471 push(value2);
1472 break;
1473 }
1474 case Bytecodes::_wide:
1475 default:
1476 {
1477 // The iterator should skip this.
1478 ShouldNotReachHere();
1479 break;
1480 }
1481 }
1482
1483 if (CITraceTypeFlow) {
1484 print_on(tty);
1485 }
1486
1487 return (_trap_bci != -1);
1488 }
1489
1490 #ifndef PRODUCT
1491 // ------------------------------------------------------------------
1492 // ciTypeFlow::StateVector::print_cell_on
1493 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1494 ciType* type = type_at(c);
1495 if (type == top_type()) {
1496 st->print("top");
1497 } else if (type == bottom_type()) {
1498 st->print("bottom");
1499 } else if (type == null_type()) {
1500 st->print("null");
1501 } else if (type == long2_type()) {
1502 st->print("long2");
1503 } else if (type == double2_type()) {
1504 st->print("double2");
1505 } else if (is_int(type)) {
1506 st->print("int");
1507 } else if (is_long(type)) {
1508 st->print("long");
1509 } else if (is_float(type)) {
1510 st->print("float");
1511 } else if (is_double(type)) {
1512 st->print("double");
1513 } else if (type->is_return_address()) {
1514 st->print("address(%d)", type->as_return_address()->bci());
1515 } else {
1516 if (type->is_klass()) {
1517 type->as_klass()->name()->print_symbol_on(st);
1518 } else {
1519 st->print("UNEXPECTED TYPE");
1520 type->print();
1521 }
1522 }
1523 }
1524
1525 // ------------------------------------------------------------------
1526 // ciTypeFlow::StateVector::print_on
1527 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1528 int num_locals = _outer->max_locals();
1529 int num_stack = stack_size();
1530 int num_monitors = monitor_count();
1531 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1532 if (num_stack >= 0) {
1533 int i;
1534 for (i = 0; i < num_locals; i++) {
1535 st->print(" local %2d : ", i);
1536 print_cell_on(st, local(i));
1537 st->cr();
1538 }
1539 for (i = 0; i < num_stack; i++) {
1540 st->print(" stack %2d : ", i);
1541 print_cell_on(st, stack(i));
1542 st->cr();
1543 }
1544 }
1545 }
1546 #endif
1547
1548
1549 // ------------------------------------------------------------------
1550 // ciTypeFlow::SuccIter::next
1551 //
1552 void ciTypeFlow::SuccIter::next() {
1553 int succ_ct = _pred->successors()->length();
1554 int next = _index + 1;
1555 if (next < succ_ct) {
1556 _index = next;
1557 _succ = _pred->successors()->at(next);
1558 return;
1559 }
1560 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1561 // Do not compile any code for unloaded exception types.
1562 // Following compiler passes are responsible for doing this also.
1563 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1564 if (exception_klass->is_loaded()) {
1565 _index = next;
1566 _succ = _pred->exceptions()->at(i);
1567 return;
1568 }
1569 next++;
1570 }
1571 _index = -1;
1572 _succ = nullptr;
1573 }
1574
1575 // ------------------------------------------------------------------
1576 // ciTypeFlow::SuccIter::set_succ
1577 //
1578 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1579 int succ_ct = _pred->successors()->length();
1580 if (_index < succ_ct) {
1581 _pred->successors()->at_put(_index, succ);
1582 } else {
1583 int idx = _index - succ_ct;
1584 _pred->exceptions()->at_put(idx, succ);
1585 }
1586 }
1587
1588 // ciTypeFlow::Block
1589 //
1590 // A basic block.
1591
1592 // ------------------------------------------------------------------
1593 // ciTypeFlow::Block::Block
1594 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1595 ciBlock *ciblk,
1596 ciTypeFlow::JsrSet* jsrs) : _predecessors(outer->arena(), 1, 0, nullptr) {
1597 _ciblock = ciblk;
1598 _exceptions = nullptr;
1599 _exc_klasses = nullptr;
1600 _successors = nullptr;
1601 _state = new (outer->arena()) StateVector(outer);
1602 JsrSet* new_jsrs =
1603 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1604 jsrs->copy_into(new_jsrs);
1605 _jsrs = new_jsrs;
1606 _next = nullptr;
1607 _on_work_list = false;
1608 _backedge_copy = false;
1609 _has_monitorenter = false;
1610 _trap_bci = -1;
1611 _trap_index = 0;
1612 df_init();
1613
1614 if (CITraceTypeFlow) {
1615 tty->print_cr(">> Created new block");
1616 print_on(tty);
1617 }
1618
1619 assert(this->outer() == outer, "outer link set up");
1620 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1621 }
1622
1623 // ------------------------------------------------------------------
1624 // ciTypeFlow::Block::df_init
1625 void ciTypeFlow::Block::df_init() {
1626 _pre_order = -1; assert(!has_pre_order(), "");
1627 _post_order = -1; assert(!has_post_order(), "");
1628 _loop = nullptr;
1629 _irreducible_loop_head = false;
1630 _irreducible_loop_secondary_entry = false;
1631 _rpo_next = nullptr;
1632 }
1633
1634 // ------------------------------------------------------------------
1635 // ciTypeFlow::Block::successors
1636 //
1637 // Get the successors for this Block.
1638 GrowableArray<ciTypeFlow::Block*>*
1639 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1640 ciTypeFlow::StateVector* state,
1641 ciTypeFlow::JsrSet* jsrs) {
1642 if (_successors == nullptr) {
1643 if (CITraceTypeFlow) {
1644 tty->print(">> Computing successors for block ");
1645 print_value_on(tty);
1646 tty->cr();
1647 }
1648
1649 ciTypeFlow* analyzer = outer();
1650 Arena* arena = analyzer->arena();
1651 Block* block = nullptr;
1652 bool has_successor = !has_trap() &&
1653 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1654 if (!has_successor) {
1655 _successors =
1656 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1657 // No successors
1658 } else if (control() == ciBlock::fall_through_bci) {
1659 assert(str->cur_bci() == limit(), "bad block end");
1660 // This block simply falls through to the next.
1661 _successors =
1662 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1663
1664 Block* block = analyzer->block_at(limit(), _jsrs);
1665 assert(_successors->length() == FALL_THROUGH, "");
1666 _successors->append(block);
1667 } else {
1668 int current_bci = str->cur_bci();
1669 int next_bci = str->next_bci();
1670 int branch_bci = -1;
1671 Block* target = nullptr;
1672 assert(str->next_bci() == limit(), "bad block end");
1673 // This block is not a simple fall-though. Interpret
1674 // the current bytecode to find our successors.
1675 switch (str->cur_bc()) {
1676 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1677 case Bytecodes::_iflt: case Bytecodes::_ifge:
1678 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1679 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1680 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1681 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1682 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1683 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1684 // Our successors are the branch target and the next bci.
1685 branch_bci = str->get_dest();
1686 _successors =
1687 new (arena) GrowableArray<Block*>(arena, 2, 0, nullptr);
1688 assert(_successors->length() == IF_NOT_TAKEN, "");
1689 _successors->append(analyzer->block_at(next_bci, jsrs));
1690 assert(_successors->length() == IF_TAKEN, "");
1691 _successors->append(analyzer->block_at(branch_bci, jsrs));
1692 break;
1693
1694 case Bytecodes::_goto:
1695 branch_bci = str->get_dest();
1696 _successors =
1697 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1698 assert(_successors->length() == GOTO_TARGET, "");
1699 _successors->append(analyzer->block_at(branch_bci, jsrs));
1700 break;
1701
1702 case Bytecodes::_jsr:
1703 branch_bci = str->get_dest();
1704 _successors =
1705 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1706 assert(_successors->length() == GOTO_TARGET, "");
1707 _successors->append(analyzer->block_at(branch_bci, jsrs));
1708 break;
1709
1710 case Bytecodes::_goto_w:
1711 case Bytecodes::_jsr_w:
1712 _successors =
1713 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1714 assert(_successors->length() == GOTO_TARGET, "");
1715 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1716 break;
1717
1718 case Bytecodes::_tableswitch: {
1719 Bytecode_tableswitch tableswitch(str);
1720
1721 int len = tableswitch.length();
1722 _successors =
1723 new (arena) GrowableArray<Block*>(arena, len+1, 0, nullptr);
1724 int bci = current_bci + tableswitch.default_offset();
1725 Block* block = analyzer->block_at(bci, jsrs);
1726 assert(_successors->length() == SWITCH_DEFAULT, "");
1727 _successors->append(block);
1728 while (--len >= 0) {
1729 int bci = current_bci + tableswitch.dest_offset_at(len);
1730 block = analyzer->block_at(bci, jsrs);
1731 assert(_successors->length() >= SWITCH_CASES, "");
1732 _successors->append_if_missing(block);
1733 }
1734 break;
1735 }
1736
1737 case Bytecodes::_lookupswitch: {
1738 Bytecode_lookupswitch lookupswitch(str);
1739
1740 int npairs = lookupswitch.number_of_pairs();
1741 _successors =
1742 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, nullptr);
1743 int bci = current_bci + lookupswitch.default_offset();
1744 Block* block = analyzer->block_at(bci, jsrs);
1745 assert(_successors->length() == SWITCH_DEFAULT, "");
1746 _successors->append(block);
1747 while(--npairs >= 0) {
1748 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1749 int bci = current_bci + pair.offset();
1750 Block* block = analyzer->block_at(bci, jsrs);
1751 assert(_successors->length() >= SWITCH_CASES, "");
1752 _successors->append_if_missing(block);
1753 }
1754 break;
1755 }
1756
1757 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1758 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1759 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1760 case Bytecodes::_return:
1761 _successors =
1762 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1763 // No successors
1764 break;
1765
1766 case Bytecodes::_ret: {
1767 _successors =
1768 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1769
1770 Cell local = state->local(str->get_index());
1771 ciType* return_address = state->type_at(local);
1772 assert(return_address->is_return_address(), "verify: wrong type");
1773 int bci = return_address->as_return_address()->bci();
1774 assert(_successors->length() == GOTO_TARGET, "");
1775 _successors->append(analyzer->block_at(bci, jsrs));
1776 break;
1777 }
1778
1779 case Bytecodes::_wide:
1780 default:
1781 ShouldNotReachHere();
1782 break;
1783 }
1784 }
1785
1786 // Set predecessor information
1787 for (int i = 0; i < _successors->length(); i++) {
1788 Block* block = _successors->at(i);
1789 block->predecessors()->append(this);
1790 }
1791 }
1792 return _successors;
1793 }
1794
1795 // ------------------------------------------------------------------
1796 // ciTypeFlow::Block:compute_exceptions
1797 //
1798 // Compute the exceptional successors and types for this Block.
1799 void ciTypeFlow::Block::compute_exceptions() {
1800 assert(_exceptions == nullptr && _exc_klasses == nullptr, "repeat");
1801
1802 if (CITraceTypeFlow) {
1803 tty->print(">> Computing exceptions for block ");
1804 print_value_on(tty);
1805 tty->cr();
1806 }
1807
1808 ciTypeFlow* analyzer = outer();
1809 Arena* arena = analyzer->arena();
1810
1811 // Any bci in the block will do.
1812 ciExceptionHandlerStream str(analyzer->method(), start());
1813
1814 // Allocate our growable arrays.
1815 int exc_count = str.count();
1816 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, nullptr);
1817 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1818 0, nullptr);
1819
1820 for ( ; !str.is_done(); str.next()) {
1821 ciExceptionHandler* handler = str.handler();
1822 int bci = handler->handler_bci();
1823 ciInstanceKlass* klass = nullptr;
1824 if (bci == -1) {
1825 // There is no catch all. It is possible to exit the method.
1826 break;
1827 }
1828 if (handler->is_catch_all()) {
1829 klass = analyzer->env()->Throwable_klass();
1830 } else {
1831 klass = handler->catch_klass();
1832 }
1833 Block* block = analyzer->block_at(bci, _jsrs);
1834 _exceptions->append(block);
1835 block->predecessors()->append(this);
1836 _exc_klasses->append(klass);
1837 }
1838 }
1839
1840 // ------------------------------------------------------------------
1841 // ciTypeFlow::Block::set_backedge_copy
1842 // Use this only to make a pre-existing public block into a backedge copy.
1843 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1844 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1845 _backedge_copy = z;
1846 }
1847
1848 // Analogous to PhaseIdealLoop::is_in_irreducible_loop
1849 bool ciTypeFlow::Block::is_in_irreducible_loop() const {
1850 if (!outer()->has_irreducible_entry()) {
1851 return false; // No irreducible loop in method.
1852 }
1853 Loop* lp = loop(); // Innermost loop containing block.
1854 if (lp == nullptr) {
1855 assert(!is_post_visited(), "must have enclosing loop once post-visited");
1856 return false; // Not yet processed, so we do not know, yet.
1857 }
1858 // Walk all the way up the loop-tree, search for an irreducible loop.
1859 do {
1860 if (lp->is_irreducible()) {
1861 return true; // We are in irreducible loop.
1862 }
1863 if (lp->head()->pre_order() == 0) {
1864 return false; // Found root loop, terminate.
1865 }
1866 lp = lp->parent();
1867 } while (lp != nullptr);
1868 // We have "lp->parent() == nullptr", which happens only for infinite loops,
1869 // where no parent is attached to the loop. We did not find any irreducible
1870 // loop from this block out to lp. Thus lp only has one entry, and no exit
1871 // (it is infinite and reducible). We can always rewrite an infinite loop
1872 // that is nested inside other loops:
1873 // while(condition) { infinite_loop; }
1874 // with an equivalent program where the infinite loop is an outermost loop
1875 // that is not nested in any loop:
1876 // while(condition) { break; } infinite_loop;
1877 // Thus, we can understand lp as an outermost loop, and can terminate and
1878 // conclude: this block is in no irreducible loop.
1879 return false;
1880 }
1881
1882 // ------------------------------------------------------------------
1883 // ciTypeFlow::Block::is_clonable_exit
1884 //
1885 // At most 2 normal successors, one of which continues looping,
1886 // and all exceptional successors must exit.
1887 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1888 int normal_cnt = 0;
1889 int in_loop_cnt = 0;
1890 for (SuccIter iter(this); !iter.done(); iter.next()) {
1891 Block* succ = iter.succ();
1892 if (iter.is_normal_ctrl()) {
1893 if (++normal_cnt > 2) return false;
1894 if (lp->contains(succ->loop())) {
1895 if (++in_loop_cnt > 1) return false;
1896 }
1897 } else {
1898 if (lp->contains(succ->loop())) return false;
1899 }
1900 }
1901 return in_loop_cnt == 1;
1902 }
1903
1904 // ------------------------------------------------------------------
1905 // ciTypeFlow::Block::looping_succ
1906 //
1907 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1908 assert(successors()->length() <= 2, "at most 2 normal successors");
1909 for (SuccIter iter(this); !iter.done(); iter.next()) {
1910 Block* succ = iter.succ();
1911 if (lp->contains(succ->loop())) {
1912 return succ;
1913 }
1914 }
1915 return nullptr;
1916 }
1917
1918 #ifndef PRODUCT
1919 // ------------------------------------------------------------------
1920 // ciTypeFlow::Block::print_value_on
1921 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1922 if (has_pre_order()) st->print("#%-2d ", pre_order());
1923 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1924 st->print("[%d - %d)", start(), limit());
1925 if (is_loop_head()) st->print(" lphd");
1926 if (is_in_irreducible_loop()) st->print(" in_irred");
1927 if (is_irreducible_loop_head()) st->print(" irred_head");
1928 if (is_irreducible_loop_secondary_entry()) st->print(" irred_entry");
1929 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1930 if (is_backedge_copy()) st->print("/backedge_copy");
1931 }
1932
1933 // ------------------------------------------------------------------
1934 // ciTypeFlow::Block::print_on
1935 void ciTypeFlow::Block::print_on(outputStream* st) const {
1936 if ((Verbose || WizardMode) && (limit() >= 0)) {
1937 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1938 outer()->method()->print_codes_on(start(), limit(), st);
1939 }
1940 st->print_cr(" ==================================================== ");
1941 st->print (" ");
1942 print_value_on(st);
1943 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1944 if (loop() && loop()->parent() != nullptr) {
1945 st->print(" loops:");
1946 Loop* lp = loop();
1947 do {
1948 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1949 if (lp->is_irreducible()) st->print("(ir)");
1950 lp = lp->parent();
1951 } while (lp->parent() != nullptr);
1952 }
1953 st->cr();
1954 _state->print_on(st);
1955 if (_successors == nullptr) {
1956 st->print_cr(" No successor information");
1957 } else {
1958 int num_successors = _successors->length();
1959 st->print_cr(" Successors : %d", num_successors);
1960 for (int i = 0; i < num_successors; i++) {
1961 Block* successor = _successors->at(i);
1962 st->print(" ");
1963 successor->print_value_on(st);
1964 st->cr();
1965 }
1966 }
1967 if (_predecessors.is_empty()) {
1968 st->print_cr(" No predecessor information");
1969 } else {
1970 int num_predecessors = _predecessors.length();
1971 st->print_cr(" Predecessors : %d", num_predecessors);
1972 for (int i = 0; i < num_predecessors; i++) {
1973 Block* predecessor = _predecessors.at(i);
1974 st->print(" ");
1975 predecessor->print_value_on(st);
1976 st->cr();
1977 }
1978 }
1979 if (_exceptions == nullptr) {
1980 st->print_cr(" No exception information");
1981 } else {
1982 int num_exceptions = _exceptions->length();
1983 st->print_cr(" Exceptions : %d", num_exceptions);
1984 for (int i = 0; i < num_exceptions; i++) {
1985 Block* exc_succ = _exceptions->at(i);
1986 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1987 st->print(" ");
1988 exc_succ->print_value_on(st);
1989 st->print(" -- ");
1990 exc_klass->name()->print_symbol_on(st);
1991 st->cr();
1992 }
1993 }
1994 if (has_trap()) {
1995 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1996 }
1997 st->print_cr(" ==================================================== ");
1998 }
1999 #endif
2000
2001 #ifndef PRODUCT
2002 // ------------------------------------------------------------------
2003 // ciTypeFlow::LocalSet::print_on
2004 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2005 st->print("{");
2006 for (int i = 0; i < max; i++) {
2007 if (test(i)) st->print(" %d", i);
2008 }
2009 if (limit > max) {
2010 st->print(" %d..%d ", max, limit);
2011 }
2012 st->print(" }");
2013 }
2014 #endif
2015
2016 // ciTypeFlow
2017 //
2018 // This is a pass over the bytecodes which computes the following:
2019 // basic block structure
2020 // interpreter type-states (a la the verifier)
2021
2022 // ------------------------------------------------------------------
2023 // ciTypeFlow::ciTypeFlow
2024 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2025 _env = env;
2026 _method = method;
2027 _has_irreducible_entry = false;
2028 _osr_bci = osr_bci;
2029 _failure_reason = nullptr;
2030 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2031 _work_list = nullptr;
2032
2033 int ciblock_count = _method->get_method_blocks()->num_blocks();
2034 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, ciblock_count);
2035 for (int i = 0; i < ciblock_count; i++) {
2036 _idx_to_blocklist[i] = nullptr;
2037 }
2038 _block_map = nullptr; // until all blocks are seen
2039 _jsr_records = nullptr;
2040 }
2041
2042 // ------------------------------------------------------------------
2043 // ciTypeFlow::work_list_next
2044 //
2045 // Get the next basic block from our work list.
2046 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2047 assert(!work_list_empty(), "work list must not be empty");
2048 Block* next_block = _work_list;
2049 _work_list = next_block->next();
2050 next_block->set_next(nullptr);
2051 next_block->set_on_work_list(false);
2052 return next_block;
2053 }
2054
2055 // ------------------------------------------------------------------
2056 // ciTypeFlow::add_to_work_list
2057 //
2058 // Add a basic block to our work list.
2059 // List is sorted by decreasing postorder sort (same as increasing RPO)
2060 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2061 assert(!block->is_on_work_list(), "must not already be on work list");
2062
2063 if (CITraceTypeFlow) {
2064 tty->print(">> Adding block ");
2065 block->print_value_on(tty);
2066 tty->print_cr(" to the work list : ");
2067 }
2068
2069 block->set_on_work_list(true);
2070
2071 // decreasing post order sort
2072
2073 Block* prev = nullptr;
2074 Block* current = _work_list;
2075 int po = block->post_order();
2076 while (current != nullptr) {
2077 if (!current->has_post_order() || po > current->post_order())
2078 break;
2079 prev = current;
2080 current = current->next();
2081 }
2082 if (prev == nullptr) {
2083 block->set_next(_work_list);
2084 _work_list = block;
2085 } else {
2086 block->set_next(current);
2087 prev->set_next(block);
2088 }
2089
2090 if (CITraceTypeFlow) {
2091 tty->cr();
2092 }
2093 }
2094
2095 // ------------------------------------------------------------------
2096 // ciTypeFlow::block_at
2097 //
2098 // Return the block beginning at bci which has a JsrSet compatible
2099 // with jsrs.
2100 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2101 // First find the right ciBlock.
2102 if (CITraceTypeFlow) {
2103 tty->print(">> Requesting block for %d/", bci);
2104 jsrs->print_on(tty);
2105 tty->cr();
2106 }
2107
2108 ciBlock* ciblk = _method->get_method_blocks()->block_containing(bci);
2109 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2110 Block* block = get_block_for(ciblk->index(), jsrs, option);
2111
2112 assert(block == nullptr? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2113
2114 if (CITraceTypeFlow) {
2115 if (block != nullptr) {
2116 tty->print(">> Found block ");
2117 block->print_value_on(tty);
2118 tty->cr();
2119 } else {
2120 tty->print_cr(">> No such block.");
2121 }
2122 }
2123
2124 return block;
2125 }
2126
2127 // ------------------------------------------------------------------
2128 // ciTypeFlow::make_jsr_record
2129 //
2130 // Make a JsrRecord for a given (entry, return) pair, if such a record
2131 // does not already exist.
2132 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2133 int return_address) {
2134 if (_jsr_records == nullptr) {
2135 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2136 2,
2137 0,
2138 nullptr);
2139 }
2140 JsrRecord* record = nullptr;
2141 int len = _jsr_records->length();
2142 for (int i = 0; i < len; i++) {
2143 JsrRecord* record = _jsr_records->at(i);
2144 if (record->entry_address() == entry_address &&
2145 record->return_address() == return_address) {
2146 return record;
2147 }
2148 }
2149
2150 record = new (arena()) JsrRecord(entry_address, return_address);
2151 _jsr_records->append(record);
2152 return record;
2153 }
2154
2155 // ------------------------------------------------------------------
2156 // ciTypeFlow::flow_exceptions
2157 //
2158 // Merge the current state into all exceptional successors at the
2159 // current point in the code.
2160 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2161 GrowableArray<ciInstanceKlass*>* exc_klasses,
2162 ciTypeFlow::StateVector* state) {
2163 int len = exceptions->length();
2164 assert(exc_klasses->length() == len, "must have same length");
2165 for (int i = 0; i < len; i++) {
2166 Block* block = exceptions->at(i);
2167 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2168
2169 if (!exception_klass->is_loaded()) {
2170 // Do not compile any code for unloaded exception types.
2171 // Following compiler passes are responsible for doing this also.
2172 continue;
2173 }
2174
2175 if (block->meet_exception(exception_klass, state)) {
2176 // Block was modified and has PO. Add it to the work list.
2177 if (block->has_post_order() &&
2178 !block->is_on_work_list()) {
2179 add_to_work_list(block);
2180 }
2181 }
2182 }
2183 }
2184
2185 // ------------------------------------------------------------------
2186 // ciTypeFlow::flow_successors
2187 //
2188 // Merge the current state into all successors at the current point
2189 // in the code.
2190 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2191 ciTypeFlow::StateVector* state) {
2192 int len = successors->length();
2193 for (int i = 0; i < len; i++) {
2194 Block* block = successors->at(i);
2195 if (block->meet(state)) {
2196 // Block was modified and has PO. Add it to the work list.
2197 if (block->has_post_order() &&
2198 !block->is_on_work_list()) {
2199 add_to_work_list(block);
2200 }
2201 }
2202 }
2203 }
2204
2205 // ------------------------------------------------------------------
2206 // ciTypeFlow::can_trap
2207 //
2208 // Tells if a given instruction is able to generate an exception edge.
2209 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2210 // Cf. GenerateOopMap::do_exception_edge.
2211 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2212
2213 switch (str.cur_bc()) {
2214 case Bytecodes::_ldc:
2215 case Bytecodes::_ldc_w:
2216 case Bytecodes::_ldc2_w:
2217 return str.is_in_error() || !str.get_constant().is_loaded();
2218
2219 case Bytecodes::_aload_0:
2220 // These bytecodes can trap for rewriting. We need to assume that
2221 // they do not throw exceptions to make the monitor analysis work.
2222 return false;
2223
2224 case Bytecodes::_ireturn:
2225 case Bytecodes::_lreturn:
2226 case Bytecodes::_freturn:
2227 case Bytecodes::_dreturn:
2228 case Bytecodes::_areturn:
2229 case Bytecodes::_return:
2230 // We can assume the monitor stack is empty in this analysis.
2231 return false;
2232
2233 case Bytecodes::_monitorexit:
2234 // We can assume monitors are matched in this analysis.
2235 return false;
2236
2237 default:
2238 return true;
2239 }
2240 }
2241
2242 // ------------------------------------------------------------------
2243 // ciTypeFlow::clone_loop_heads
2244 //
2245 // Clone the loop heads
2246 bool ciTypeFlow::clone_loop_heads(StateVector* temp_vector, JsrSet* temp_set) {
2247 bool rslt = false;
2248 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2249 Loop* lp = iter.current();
2250 Block* head = lp->head();
2251 if (lp == loop_tree_root() ||
2252 lp->is_irreducible() ||
2253 !head->is_clonable_exit(lp))
2254 continue;
2255
2256 // Avoid BoxLock merge.
2257 if (EliminateNestedLocks && head->has_monitorenter())
2258 continue;
2259
2260 // check not already cloned
2261 if (head->backedge_copy_count() != 0)
2262 continue;
2263
2264 // Don't clone head of OSR loop to get correct types in start block.
2265 if (is_osr_flow() && head->start() == start_bci())
2266 continue;
2267
2268 // check _no_ shared head below us
2269 Loop* ch;
2270 for (ch = lp->child(); ch != nullptr && ch->head() != head; ch = ch->sibling());
2271 if (ch != nullptr)
2272 continue;
2273
2274 // Clone head
2275 Block* new_head = head->looping_succ(lp);
2276 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2277 // Update lp's info
2278 clone->set_loop(lp);
2279 lp->set_head(new_head);
2280 lp->set_tail(clone);
2281 // And move original head into outer loop
2282 head->set_loop(lp->parent());
2283
2284 rslt = true;
2285 }
2286 return rslt;
2287 }
2288
2289 // ------------------------------------------------------------------
2290 // ciTypeFlow::clone_loop_head
2291 //
2292 // Clone lp's head and replace tail's successors with clone.
2293 //
2294 // |
2295 // v
2296 // head <-> body
2297 // |
2298 // v
2299 // exit
2300 //
2301 // new_head
2302 //
2303 // |
2304 // v
2305 // head ----------\
2306 // | |
2307 // | v
2308 // | clone <-> body
2309 // | |
2310 // | /--/
2311 // | |
2312 // v v
2313 // exit
2314 //
2315 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2316 Block* head = lp->head();
2317 Block* tail = lp->tail();
2318 if (CITraceTypeFlow) {
2319 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2320 tty->print(" for predecessor "); tail->print_value_on(tty);
2321 tty->cr();
2322 }
2323 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2324 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2325
2326 assert(!clone->has_pre_order(), "just created");
2327 clone->set_next_pre_order();
2328
2329 // Accumulate profiled count for all backedges that share this loop's head
2330 int total_count = lp->profiled_count();
2331 for (Loop* lp1 = lp->parent(); lp1 != nullptr; lp1 = lp1->parent()) {
2332 for (Loop* lp2 = lp1; lp2 != nullptr; lp2 = lp2->sibling()) {
2333 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2334 total_count += lp2->profiled_count();
2335 }
2336 }
2337 }
2338 // Have the most frequent ones branch to the clone instead
2339 int count = 0;
2340 int loops_with_shared_head = 0;
2341 Block* latest_tail = tail;
2342 bool done = false;
2343 for (Loop* lp1 = lp; lp1 != nullptr && !done; lp1 = lp1->parent()) {
2344 for (Loop* lp2 = lp1; lp2 != nullptr && !done; lp2 = lp2->sibling()) {
2345 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2346 count += lp2->profiled_count();
2347 if (lp2->tail()->post_order() < latest_tail->post_order()) {
2348 latest_tail = lp2->tail();
2349 }
2350 loops_with_shared_head++;
2351 for (SuccIter iter(lp2->tail()); !iter.done(); iter.next()) {
2352 if (iter.succ() == head) {
2353 iter.set_succ(clone);
2354 // Update predecessor information
2355 head->predecessors()->remove(lp2->tail());
2356 clone->predecessors()->append(lp2->tail());
2357 }
2358 }
2359 flow_block(lp2->tail(), temp_vector, temp_set);
2360 if (lp2->head() == lp2->tail()) {
2361 // For self-loops, clone->head becomes clone->clone
2362 flow_block(clone, temp_vector, temp_set);
2363 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2364 if (iter.succ() == lp2->head()) {
2365 iter.set_succ(clone);
2366 // Update predecessor information
2367 lp2->head()->predecessors()->remove(clone);
2368 clone->predecessors()->append(clone);
2369 break;
2370 }
2371 }
2372 }
2373 if (total_count == 0 || count > (total_count * .9)) {
2374 done = true;
2375 }
2376 }
2377 }
2378 }
2379 assert(loops_with_shared_head >= 1, "at least one new");
2380 clone->set_rpo_next(latest_tail->rpo_next());
2381 latest_tail->set_rpo_next(clone);
2382 flow_block(clone, temp_vector, temp_set);
2383
2384 return clone;
2385 }
2386
2387 // ------------------------------------------------------------------
2388 // ciTypeFlow::flow_block
2389 //
2390 // Interpret the effects of the bytecodes on the incoming state
2391 // vector of a basic block. Push the changed state to succeeding
2392 // basic blocks.
2393 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2394 ciTypeFlow::StateVector* state,
2395 ciTypeFlow::JsrSet* jsrs) {
2396 if (CITraceTypeFlow) {
2397 tty->print("\n>> ANALYZING BLOCK : ");
2398 tty->cr();
2399 block->print_on(tty);
2400 }
2401 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2402
2403 int start = block->start();
2404 int limit = block->limit();
2405 int control = block->control();
2406 if (control != ciBlock::fall_through_bci) {
2407 limit = control;
2408 }
2409
2410 // Grab the state from the current block.
2411 block->copy_state_into(state);
2412 state->def_locals()->clear();
2413
2414 GrowableArray<Block*>* exceptions = block->exceptions();
2415 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2416 bool has_exceptions = exceptions->length() > 0;
2417
2418 bool exceptions_used = false;
2419
2420 ciBytecodeStream str(method());
2421 str.reset_to_bci(start);
2422 Bytecodes::Code code;
2423 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2424 str.cur_bci() < limit) {
2425 // Check for exceptional control flow from this point.
2426 if (has_exceptions && can_trap(str)) {
2427 flow_exceptions(exceptions, exc_klasses, state);
2428 exceptions_used = true;
2429 }
2430 // Apply the effects of the current bytecode to our state.
2431 bool res = state->apply_one_bytecode(&str);
2432
2433 // Watch for bailouts.
2434 if (failing()) return;
2435
2436 if (str.cur_bc() == Bytecodes::_monitorenter) {
2437 block->set_has_monitorenter();
2438 }
2439
2440 if (res) {
2441
2442 // We have encountered a trap. Record it in this block.
2443 block->set_trap(state->trap_bci(), state->trap_index());
2444
2445 if (CITraceTypeFlow) {
2446 tty->print_cr(">> Found trap");
2447 block->print_on(tty);
2448 }
2449
2450 // Save set of locals defined in this block
2451 block->def_locals()->add(state->def_locals());
2452
2453 // Record (no) successors.
2454 block->successors(&str, state, jsrs);
2455
2456 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2457
2458 // Discontinue interpretation of this Block.
2459 return;
2460 }
2461 }
2462
2463 GrowableArray<Block*>* successors = nullptr;
2464 if (control != ciBlock::fall_through_bci) {
2465 // Check for exceptional control flow from this point.
2466 if (has_exceptions && can_trap(str)) {
2467 flow_exceptions(exceptions, exc_klasses, state);
2468 exceptions_used = true;
2469 }
2470
2471 // Fix the JsrSet to reflect effect of the bytecode.
2472 block->copy_jsrs_into(jsrs);
2473 jsrs->apply_control(this, &str, state);
2474
2475 // Find successor edges based on old state and new JsrSet.
2476 successors = block->successors(&str, state, jsrs);
2477
2478 // Apply the control changes to the state.
2479 state->apply_one_bytecode(&str);
2480 } else {
2481 // Fall through control
2482 successors = block->successors(&str, nullptr, nullptr);
2483 }
2484
2485 // Save set of locals defined in this block
2486 block->def_locals()->add(state->def_locals());
2487
2488 // Remove untaken exception paths
2489 if (!exceptions_used)
2490 exceptions->clear();
2491
2492 // Pass our state to successors.
2493 flow_successors(successors, state);
2494 }
2495
2496 // ------------------------------------------------------------------
2497 // ciTypeFlow::PreOrderLoops::next
2498 //
2499 // Advance to next loop tree using a preorder, left-to-right traversal.
2500 void ciTypeFlow::PreorderLoops::next() {
2501 assert(!done(), "must not be done.");
2502 if (_current->child() != nullptr) {
2503 _current = _current->child();
2504 } else if (_current->sibling() != nullptr) {
2505 _current = _current->sibling();
2506 } else {
2507 while (_current != _root && _current->sibling() == nullptr) {
2508 _current = _current->parent();
2509 }
2510 if (_current == _root) {
2511 _current = nullptr;
2512 assert(done(), "must be done.");
2513 } else {
2514 assert(_current->sibling() != nullptr, "must be more to do");
2515 _current = _current->sibling();
2516 }
2517 }
2518 }
2519
2520 // If the tail is a branch to the head, retrieve how many times that path was taken from profiling
2521 int ciTypeFlow::Loop::profiled_count() {
2522 if (_profiled_count >= 0) {
2523 return _profiled_count;
2524 }
2525 ciMethodData* methodData = outer()->method()->method_data();
2526 if (!methodData->is_mature()) {
2527 _profiled_count = 0;
2528 return 0;
2529 }
2530 ciTypeFlow::Block* tail = this->tail();
2531 if (tail->control() == -1 || tail->has_trap()) {
2532 _profiled_count = 0;
2533 return 0;
2534 }
2535
2536 ciProfileData* data = methodData->bci_to_data(tail->control());
2537
2538 if (data == nullptr || !data->is_JumpData()) {
2539 _profiled_count = 0;
2540 return 0;
2541 }
2542
2543 ciBytecodeStream iter(outer()->method());
2544 iter.reset_to_bci(tail->control());
2545
2546 bool is_an_if = false;
2547 bool wide = false;
2548 Bytecodes::Code bc = iter.next();
2549 switch (bc) {
2550 case Bytecodes::_ifeq:
2551 case Bytecodes::_ifne:
2552 case Bytecodes::_iflt:
2553 case Bytecodes::_ifge:
2554 case Bytecodes::_ifgt:
2555 case Bytecodes::_ifle:
2556 case Bytecodes::_if_icmpeq:
2557 case Bytecodes::_if_icmpne:
2558 case Bytecodes::_if_icmplt:
2559 case Bytecodes::_if_icmpge:
2560 case Bytecodes::_if_icmpgt:
2561 case Bytecodes::_if_icmple:
2562 case Bytecodes::_if_acmpeq:
2563 case Bytecodes::_if_acmpne:
2564 case Bytecodes::_ifnull:
2565 case Bytecodes::_ifnonnull:
2566 is_an_if = true;
2567 break;
2568 case Bytecodes::_goto_w:
2569 case Bytecodes::_jsr_w:
2570 wide = true;
2571 break;
2572 case Bytecodes::_goto:
2573 case Bytecodes::_jsr:
2574 break;
2575 default:
2576 fatal(" invalid bytecode: %s", Bytecodes::name(iter.cur_bc()));
2577 }
2578
2579 GrowableArray<ciTypeFlow::Block*>* succs = tail->successors();
2580
2581 if (!is_an_if) {
2582 assert(((wide ? iter.get_far_dest() : iter.get_dest()) == head()->start()) == (succs->at(ciTypeFlow::GOTO_TARGET) == head()), "branch should lead to loop head");
2583 if (succs->at(ciTypeFlow::GOTO_TARGET) == head()) {
2584 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2585 return _profiled_count;
2586 }
2587 } else {
2588 assert((iter.get_dest() == head()->start()) == (succs->at(ciTypeFlow::IF_TAKEN) == head()), "bytecode and CFG not consistent");
2589 assert((tail->limit() == head()->start()) == (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()), "bytecode and CFG not consistent");
2590 if (succs->at(ciTypeFlow::IF_TAKEN) == head()) {
2591 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2592 return _profiled_count;
2593 } else if (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()) {
2594 _profiled_count = outer()->method()->scale_count(data->as_BranchData()->not_taken());
2595 return _profiled_count;
2596 }
2597 }
2598
2599 _profiled_count = 0;
2600 return _profiled_count;
2601 }
2602
2603 bool ciTypeFlow::Loop::at_insertion_point(Loop* lp, Loop* current) {
2604 int lp_pre_order = lp->head()->pre_order();
2605 if (current->head()->pre_order() < lp_pre_order) {
2606 return true;
2607 } else if (current->head()->pre_order() > lp_pre_order) {
2608 return false;
2609 }
2610 // In the case of a shared head, make the most frequent head/tail (as reported by profiling) the inner loop
2611 if (current->head() == lp->head()) {
2612 int lp_count = lp->profiled_count();
2613 int current_count = current->profiled_count();
2614 if (current_count < lp_count) {
2615 return true;
2616 } else if (current_count > lp_count) {
2617 return false;
2618 }
2619 }
2620 if (current->tail()->pre_order() > lp->tail()->pre_order()) {
2621 return true;
2622 }
2623 return false;
2624 }
2625
2626 // ------------------------------------------------------------------
2627 // ciTypeFlow::Loop::sorted_merge
2628 //
2629 // Merge the branch lp into this branch, sorting on the loop head
2630 // pre_orders. Returns the leaf of the merged branch.
2631 // Child and sibling pointers will be setup later.
2632 // Sort is (looking from leaf towards the root)
2633 // descending on primary key: loop head's pre_order, and
2634 // ascending on secondary key: loop tail's pre_order.
2635 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2636 Loop* leaf = this;
2637 Loop* prev = nullptr;
2638 Loop* current = leaf;
2639 while (lp != nullptr) {
2640 int lp_pre_order = lp->head()->pre_order();
2641 // Find insertion point for "lp"
2642 while (current != nullptr) {
2643 if (current == lp) {
2644 return leaf; // Already in list
2645 }
2646 if (at_insertion_point(lp, current)) {
2647 break;
2648 }
2649 prev = current;
2650 current = current->parent();
2651 }
2652 Loop* next_lp = lp->parent(); // Save future list of items to insert
2653 // Insert lp before current
2654 lp->set_parent(current);
2655 if (prev != nullptr) {
2656 prev->set_parent(lp);
2657 } else {
2658 leaf = lp;
2659 }
2660 prev = lp; // Inserted item is new prev[ious]
2661 lp = next_lp; // Next item to insert
2662 }
2663 return leaf;
2664 }
2665
2666 // ------------------------------------------------------------------
2667 // ciTypeFlow::build_loop_tree
2668 //
2669 // Incrementally build loop tree.
2670 void ciTypeFlow::build_loop_tree(Block* blk) {
2671 assert(!blk->is_post_visited(), "precondition");
2672 Loop* innermost = nullptr; // merge of loop tree branches over all successors
2673
2674 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2675 Loop* lp = nullptr;
2676 Block* succ = iter.succ();
2677 if (!succ->is_post_visited()) {
2678 // Found backedge since predecessor post visited, but successor is not
2679 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2680
2681 // Create a LoopNode to mark this loop.
2682 lp = new (arena()) Loop(succ, blk);
2683 if (succ->loop() == nullptr)
2684 succ->set_loop(lp);
2685 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2686
2687 } else { // Nested loop
2688 lp = succ->loop();
2689
2690 // If succ is loop head, find outer loop.
2691 while (lp != nullptr && lp->head() == succ) {
2692 lp = lp->parent();
2693 }
2694 if (lp == nullptr) {
2695 // Infinite loop, it's parent is the root
2696 lp = loop_tree_root();
2697 }
2698 }
2699
2700 // Check for irreducible loop.
2701 // Successor has already been visited. If the successor's loop head
2702 // has already been post-visited, then this is another entry into the loop.
2703 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2704 _has_irreducible_entry = true;
2705 lp->set_irreducible(succ);
2706 if (!succ->is_on_work_list()) {
2707 // Assume irreducible entries need more data flow
2708 add_to_work_list(succ);
2709 }
2710 Loop* plp = lp->parent();
2711 if (plp == nullptr) {
2712 // This only happens for some irreducible cases. The parent
2713 // will be updated during a later pass.
2714 break;
2715 }
2716 lp = plp;
2717 }
2718
2719 // Merge loop tree branch for all successors.
2720 innermost = innermost == nullptr ? lp : innermost->sorted_merge(lp);
2721
2722 } // end loop
2723
2724 if (innermost == nullptr) {
2725 assert(blk->successors()->length() == 0, "CFG exit");
2726 blk->set_loop(loop_tree_root());
2727 } else if (innermost->head() == blk) {
2728 // If loop header, complete the tree pointers
2729 if (blk->loop() != innermost) {
2730 #ifdef ASSERT
2731 assert(blk->loop()->head() == innermost->head(), "same head");
2732 Loop* dl;
2733 for (dl = innermost; dl != nullptr && dl != blk->loop(); dl = dl->parent());
2734 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2735 #endif
2736 blk->set_loop(innermost);
2737 }
2738 innermost->def_locals()->add(blk->def_locals());
2739 Loop* l = innermost;
2740 Loop* p = l->parent();
2741 while (p && l->head() == blk) {
2742 l->set_sibling(p->child()); // Put self on parents 'next child'
2743 p->set_child(l); // Make self the first child of parent
2744 p->def_locals()->add(l->def_locals());
2745 l = p; // Walk up the parent chain
2746 p = l->parent();
2747 }
2748 } else {
2749 blk->set_loop(innermost);
2750 innermost->def_locals()->add(blk->def_locals());
2751 }
2752 }
2753
2754 // ------------------------------------------------------------------
2755 // ciTypeFlow::Loop::contains
2756 //
2757 // Returns true if lp is nested loop.
2758 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2759 assert(lp != nullptr, "");
2760 if (this == lp || head() == lp->head()) return true;
2761 int depth1 = depth();
2762 int depth2 = lp->depth();
2763 if (depth1 > depth2)
2764 return false;
2765 while (depth1 < depth2) {
2766 depth2--;
2767 lp = lp->parent();
2768 }
2769 return this == lp;
2770 }
2771
2772 // ------------------------------------------------------------------
2773 // ciTypeFlow::Loop::depth
2774 //
2775 // Loop depth
2776 int ciTypeFlow::Loop::depth() const {
2777 int dp = 0;
2778 for (Loop* lp = this->parent(); lp != nullptr; lp = lp->parent())
2779 dp++;
2780 return dp;
2781 }
2782
2783 #ifndef PRODUCT
2784 // ------------------------------------------------------------------
2785 // ciTypeFlow::Loop::print
2786 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2787 for (int i = 0; i < indent; i++) st->print(" ");
2788 st->print("%d<-%d %s",
2789 is_root() ? 0 : this->head()->pre_order(),
2790 is_root() ? 0 : this->tail()->pre_order(),
2791 is_irreducible()?" irr":"");
2792 st->print(" defs: ");
2793 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2794 st->cr();
2795 for (Loop* ch = child(); ch != nullptr; ch = ch->sibling())
2796 ch->print(st, indent+2);
2797 }
2798 #endif
2799
2800 // ------------------------------------------------------------------
2801 // ciTypeFlow::df_flow_types
2802 //
2803 // Perform the depth first type flow analysis. Helper for flow_types.
2804 void ciTypeFlow::df_flow_types(Block* start,
2805 bool do_flow,
2806 StateVector* temp_vector,
2807 JsrSet* temp_set) {
2808 int dft_len = 100;
2809 GrowableArray<Block*> stk(dft_len);
2810
2811 ciBlock* dummy = _method->get_method_blocks()->make_dummy_block();
2812 JsrSet* root_set = new JsrSet(0);
2813 Block* root_head = new (arena()) Block(this, dummy, root_set);
2814 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2815 root_head->set_pre_order(0);
2816 root_head->set_post_order(0);
2817 root_tail->set_pre_order(max_jint);
2818 root_tail->set_post_order(max_jint);
2819 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2820
2821 stk.push(start);
2822
2823 _next_pre_order = 0; // initialize pre_order counter
2824 _rpo_list = nullptr;
2825 int next_po = 0; // initialize post_order counter
2826
2827 // Compute RPO and the control flow graph
2828 int size;
2829 while ((size = stk.length()) > 0) {
2830 Block* blk = stk.top(); // Leave node on stack
2831 if (!blk->is_visited()) {
2832 // forward arc in graph
2833 assert (!blk->has_pre_order(), "");
2834 blk->set_next_pre_order();
2835
2836 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2837 // Too many basic blocks. Bail out.
2838 // This can happen when try/finally constructs are nested to depth N,
2839 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2840 // "MaxNodeLimit / 2" is used because probably the parser will
2841 // generate at least twice that many nodes and bail out.
2842 record_failure("too many basic blocks");
2843 return;
2844 }
2845 if (do_flow) {
2846 flow_block(blk, temp_vector, temp_set);
2847 if (failing()) return; // Watch for bailouts.
2848 }
2849 } else if (!blk->is_post_visited()) {
2850 // cross or back arc
2851 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2852 Block* succ = iter.succ();
2853 if (!succ->is_visited()) {
2854 stk.push(succ);
2855 }
2856 }
2857 if (stk.length() == size) {
2858 // There were no additional children, post visit node now
2859 stk.pop(); // Remove node from stack
2860
2861 build_loop_tree(blk);
2862 blk->set_post_order(next_po++); // Assign post order
2863 prepend_to_rpo_list(blk);
2864 assert(blk->is_post_visited(), "");
2865
2866 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2867 // Assume loop heads need more data flow
2868 add_to_work_list(blk);
2869 }
2870 }
2871 } else {
2872 stk.pop(); // Remove post-visited node from stack
2873 }
2874 }
2875 }
2876
2877 // ------------------------------------------------------------------
2878 // ciTypeFlow::flow_types
2879 //
2880 // Perform the type flow analysis, creating and cloning Blocks as
2881 // necessary.
2882 void ciTypeFlow::flow_types() {
2883 ResourceMark rm;
2884 StateVector* temp_vector = new StateVector(this);
2885 JsrSet* temp_set = new JsrSet(4);
2886
2887 // Create the method entry block.
2888 Block* start = block_at(start_bci(), temp_set);
2889
2890 // Load the initial state into it.
2891 const StateVector* start_state = get_start_state();
2892 if (failing()) return;
2893 start->meet(start_state);
2894
2895 // Depth first visit
2896 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2897
2898 if (failing()) return;
2899 assert(_rpo_list == start, "must be start");
2900
2901 // Any loops found?
2902 if (loop_tree_root()->child() != nullptr &&
2903 env()->comp_level() >= CompLevel_full_optimization) {
2904 // Loop optimizations are not performed on Tier1 compiles.
2905
2906 bool changed = clone_loop_heads(temp_vector, temp_set);
2907
2908 // If some loop heads were cloned, recompute postorder and loop tree
2909 if (changed) {
2910 loop_tree_root()->set_child(nullptr);
2911 for (Block* blk = _rpo_list; blk != nullptr;) {
2912 Block* next = blk->rpo_next();
2913 blk->df_init();
2914 blk = next;
2915 }
2916 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2917 }
2918 }
2919
2920 if (CITraceTypeFlow) {
2921 tty->print_cr("\nLoop tree");
2922 loop_tree_root()->print();
2923 }
2924
2925 // Continue flow analysis until fixed point reached
2926
2927 debug_only(int max_block = _next_pre_order;)
2928
2929 while (!work_list_empty()) {
2930 Block* blk = work_list_next();
2931 assert (blk->has_post_order(), "post order assigned above");
2932
2933 flow_block(blk, temp_vector, temp_set);
2934
2935 assert (max_block == _next_pre_order, "no new blocks");
2936 assert (!failing(), "no more bailouts");
2937 }
2938 }
2939
2940 // ------------------------------------------------------------------
2941 // ciTypeFlow::map_blocks
2942 //
2943 // Create the block map, which indexes blocks in reverse post-order.
2944 void ciTypeFlow::map_blocks() {
2945 assert(_block_map == nullptr, "single initialization");
2946 int block_ct = _next_pre_order;
2947 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2948 assert(block_ct == block_count(), "");
2949
2950 Block* blk = _rpo_list;
2951 for (int m = 0; m < block_ct; m++) {
2952 int rpo = blk->rpo();
2953 assert(rpo == m, "should be sequential");
2954 _block_map[rpo] = blk;
2955 blk = blk->rpo_next();
2956 }
2957 assert(blk == nullptr, "should be done");
2958
2959 for (int j = 0; j < block_ct; j++) {
2960 assert(_block_map[j] != nullptr, "must not drop any blocks");
2961 Block* block = _block_map[j];
2962 // Remove dead blocks from successor lists:
2963 for (int e = 0; e <= 1; e++) {
2964 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2965 for (int k = 0; k < l->length(); k++) {
2966 Block* s = l->at(k);
2967 if (!s->has_post_order()) {
2968 if (CITraceTypeFlow) {
2969 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2970 s->print_value_on(tty);
2971 tty->cr();
2972 }
2973 l->remove(s);
2974 --k;
2975 }
2976 }
2977 }
2978 }
2979 }
2980
2981 // ------------------------------------------------------------------
2982 // ciTypeFlow::get_block_for
2983 //
2984 // Find a block with this ciBlock which has a compatible JsrSet.
2985 // If no such block exists, create it, unless the option is no_create.
2986 // If the option is create_backedge_copy, always create a fresh backedge copy.
2987 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2988 Arena* a = arena();
2989 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2990 if (blocks == nullptr) {
2991 // Query only?
2992 if (option == no_create) return nullptr;
2993
2994 // Allocate the growable array.
2995 blocks = new (a) GrowableArray<Block*>(a, 4, 0, nullptr);
2996 _idx_to_blocklist[ciBlockIndex] = blocks;
2997 }
2998
2999 if (option != create_backedge_copy) {
3000 int len = blocks->length();
3001 for (int i = 0; i < len; i++) {
3002 Block* block = blocks->at(i);
3003 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3004 return block;
3005 }
3006 }
3007 }
3008
3009 // Query only?
3010 if (option == no_create) return nullptr;
3011
3012 // We did not find a compatible block. Create one.
3013 Block* new_block = new (a) Block(this, _method->get_method_blocks()->block(ciBlockIndex), jsrs);
3014 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
3015 blocks->append(new_block);
3016 return new_block;
3017 }
3018
3019 // ------------------------------------------------------------------
3020 // ciTypeFlow::backedge_copy_count
3021 //
3022 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
3023 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3024
3025 if (blocks == nullptr) {
3026 return 0;
3027 }
3028
3029 int count = 0;
3030 int len = blocks->length();
3031 for (int i = 0; i < len; i++) {
3032 Block* block = blocks->at(i);
3033 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3034 count++;
3035 }
3036 }
3037
3038 return count;
3039 }
3040
3041 // ------------------------------------------------------------------
3042 // ciTypeFlow::do_flow
3043 //
3044 // Perform type inference flow analysis.
3045 void ciTypeFlow::do_flow() {
3046 if (CITraceTypeFlow) {
3047 tty->print_cr("\nPerforming flow analysis on method");
3048 method()->print();
3049 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
3050 tty->cr();
3051 method()->print_codes();
3052 }
3053 if (CITraceTypeFlow) {
3054 tty->print_cr("Initial CI Blocks");
3055 print_on(tty);
3056 }
3057 flow_types();
3058 // Watch for bailouts.
3059 if (failing()) {
3060 return;
3061 }
3062
3063 map_blocks();
3064
3065 if (CIPrintTypeFlow || CITraceTypeFlow) {
3066 rpo_print_on(tty);
3067 }
3068 }
3069
3070 // ------------------------------------------------------------------
3071 // ciTypeFlow::is_dominated_by
3072 //
3073 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3074 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3075 assert(!method()->has_jsrs(), "jsrs are not supported");
3076
3077 ResourceMark rm;
3078 JsrSet* jsrs = new ciTypeFlow::JsrSet();
3079 int index = _method->get_method_blocks()->block_containing(bci)->index();
3080 int dom_index = _method->get_method_blocks()->block_containing(dom_bci)->index();
3081 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3082 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3083
3084 // Start block dominates all other blocks
3085 if (start_block()->rpo() == dom_block->rpo()) {
3086 return true;
3087 }
3088
3089 // Dominated[i] is true if block i is dominated by dom_block
3090 int num_blocks = block_count();
3091 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3092 for (int i = 0; i < num_blocks; ++i) {
3093 dominated[i] = true;
3094 }
3095 dominated[start_block()->rpo()] = false;
3096
3097 // Iterative dominator algorithm
3098 bool changed = true;
3099 while (changed) {
3100 changed = false;
3101 // Use reverse postorder iteration
3102 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3103 if (blk->is_start()) {
3104 // Ignore start block
3105 continue;
3106 }
3107 // The block is dominated if it is the dominating block
3108 // itself or if all predecessors are dominated.
3109 int index = blk->rpo();
3110 bool dom = (index == dom_block->rpo());
3111 if (!dom) {
3112 // Check if all predecessors are dominated
3113 dom = true;
3114 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3115 Block* pred = blk->predecessors()->at(i);
3116 if (!dominated[pred->rpo()]) {
3117 dom = false;
3118 break;
3119 }
3120 }
3121 }
3122 // Update dominator information
3123 if (dominated[index] != dom) {
3124 changed = true;
3125 dominated[index] = dom;
3126 }
3127 }
3128 }
3129 // block dominated by dom_block?
3130 return dominated[block->rpo()];
3131 }
3132
3133 // ------------------------------------------------------------------
3134 // ciTypeFlow::record_failure()
3135 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3136 // This is required because there is not a 1-1 relation between the ciEnv and
3137 // the TypeFlow passes within a compilation task. For example, if the compiler
3138 // is considering inlining a method, it will request a TypeFlow. If that fails,
3139 // the compilation as a whole may continue without the inlining. Some TypeFlow
3140 // requests are not optional; if they fail the requestor is responsible for
3141 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3142 void ciTypeFlow::record_failure(const char* reason) {
3143 if (env()->log() != nullptr) {
3144 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3145 }
3146 if (_failure_reason == nullptr) {
3147 // Record the first failure reason.
3148 _failure_reason = reason;
3149 }
3150 }
3151
3152 #ifndef PRODUCT
3153 void ciTypeFlow::print() const { print_on(tty); }
3154
3155 // ------------------------------------------------------------------
3156 // ciTypeFlow::print_on
3157 void ciTypeFlow::print_on(outputStream* st) const {
3158 // Walk through CI blocks
3159 st->print_cr("********************************************************");
3160 st->print ("TypeFlow for ");
3161 method()->name()->print_symbol_on(st);
3162 int limit_bci = code_size();
3163 st->print_cr(" %d bytes", limit_bci);
3164 ciMethodBlocks* mblks = _method->get_method_blocks();
3165 ciBlock* current = nullptr;
3166 for (int bci = 0; bci < limit_bci; bci++) {
3167 ciBlock* blk = mblks->block_containing(bci);
3168 if (blk != nullptr && blk != current) {
3169 current = blk;
3170 current->print_on(st);
3171
3172 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3173 int num_blocks = (blocks == nullptr) ? 0 : blocks->length();
3174
3175 if (num_blocks == 0) {
3176 st->print_cr(" No Blocks");
3177 } else {
3178 for (int i = 0; i < num_blocks; i++) {
3179 Block* block = blocks->at(i);
3180 block->print_on(st);
3181 }
3182 }
3183 st->print_cr("--------------------------------------------------------");
3184 st->cr();
3185 }
3186 }
3187 st->print_cr("********************************************************");
3188 st->cr();
3189 }
3190
3191 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3192 st->print_cr("********************************************************");
3193 st->print ("TypeFlow for ");
3194 method()->name()->print_symbol_on(st);
3195 int limit_bci = code_size();
3196 st->print_cr(" %d bytes", limit_bci);
3197 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3198 blk->print_on(st);
3199 st->print_cr("--------------------------------------------------------");
3200 st->cr();
3201 }
3202 st->print_cr("********************************************************");
3203 st->cr();
3204 }
3205 #endif