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).
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23 */
24
25 #include "ci/ciConstant.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciInlineKlass.hpp"
28 #include "ci/ciMethod.hpp"
29 #include "ci/ciMethodData.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "ci/ciTypeArrayKlass.hpp"
33 #include "ci/ciTypeFlow.hpp"
34 #include "compiler/compileLog.hpp"
35 #include "interpreter/bytecode.hpp"
36 #include "interpreter/bytecodes.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "opto/compile.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "utilities/growableArray.hpp"
43
44 // ciTypeFlow::JsrSet
45 //
46 // A JsrSet represents some set of JsrRecords. This class
47 // is used to record a set of all jsr routines which we permit
48 // execution to return (ret) from.
49 //
50 // During abstract interpretation, JsrSets are used to determine
51 // whether two paths which reach a given block are unique, and
52 // should be cloned apart, or are compatible, and should merge
53 // together.
54
55 // ------------------------------------------------------------------
56 // ciTypeFlow::JsrSet::JsrSet
57
58 // Allocate growable array storage in Arena.
59 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) : _set(arena, default_len, 0, nullptr) {
60 assert(arena != nullptr, "invariant");
61 }
62
63 // Allocate growable array storage in current ResourceArea.
64 ciTypeFlow::JsrSet::JsrSet(int default_len) : _set(default_len, 0, nullptr) {}
65
66 // ------------------------------------------------------------------
67 // ciTypeFlow::JsrSet::copy_into
68 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
69 int len = size();
70 jsrs->_set.clear();
71 for (int i = 0; i < len; i++) {
72 jsrs->_set.append(_set.at(i));
73 }
74 }
75
76 // ------------------------------------------------------------------
77 // ciTypeFlow::JsrSet::is_compatible_with
78 //
79 // !!!! MISGIVINGS ABOUT THIS... disregard
80 //
81 // Is this JsrSet compatible with some other JsrSet?
82 //
83 // In set-theoretic terms, a JsrSet can be viewed as a partial function
84 // from entry addresses to return addresses. Two JsrSets A and B are
85 // compatible iff
86 //
87 // For any x,
88 // A(x) defined and B(x) defined implies A(x) == B(x)
89 //
90 // Less formally, two JsrSets are compatible when they have identical
91 // return addresses for any entry addresses they share in common.
92 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
93 // Walk through both sets in parallel. If the same entry address
94 // appears in both sets, then the return address must match for
95 // the sets to be compatible.
96 int size1 = size();
97 int size2 = other->size();
98
99 // Special case. If nothing is on the jsr stack, then there can
100 // be no ret.
101 if (size2 == 0) {
102 return true;
103 } else if (size1 != size2) {
104 return false;
105 } else {
106 for (int i = 0; i < size1; i++) {
107 JsrRecord* record1 = record_at(i);
108 JsrRecord* record2 = other->record_at(i);
109 if (record1->entry_address() != record2->entry_address() ||
110 record1->return_address() != record2->return_address()) {
111 return false;
112 }
113 }
114 return true;
115 }
116
117 #if 0
118 int pos1 = 0;
119 int pos2 = 0;
120 int size1 = size();
121 int size2 = other->size();
122 while (pos1 < size1 && pos2 < size2) {
123 JsrRecord* record1 = record_at(pos1);
124 JsrRecord* record2 = other->record_at(pos2);
125 int entry1 = record1->entry_address();
126 int entry2 = record2->entry_address();
127 if (entry1 < entry2) {
128 pos1++;
129 } else if (entry1 > entry2) {
130 pos2++;
131 } else {
132 if (record1->return_address() == record2->return_address()) {
133 pos1++;
134 pos2++;
135 } else {
136 // These two JsrSets are incompatible.
137 return false;
138 }
139 }
140 }
141 // The two JsrSets agree.
142 return true;
143 #endif
144 }
145
146 // ------------------------------------------------------------------
147 // ciTypeFlow::JsrSet::insert_jsr_record
148 //
149 // Insert the given JsrRecord into the JsrSet, maintaining the order
150 // of the set and replacing any element with the same entry address.
151 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
152 int len = size();
153 int entry = record->entry_address();
154 int pos = 0;
155 for ( ; pos < len; pos++) {
156 JsrRecord* current = record_at(pos);
157 if (entry == current->entry_address()) {
158 // Stomp over this entry.
159 _set.at_put(pos, record);
160 assert(size() == len, "must be same size");
161 return;
162 } else if (entry < current->entry_address()) {
163 break;
164 }
165 }
166
167 // Insert the record into the list.
168 JsrRecord* swap = record;
169 JsrRecord* temp = nullptr;
170 for ( ; pos < len; pos++) {
171 temp = _set.at(pos);
172 _set.at_put(pos, swap);
173 swap = temp;
174 }
175 _set.append(swap);
176 assert(size() == len+1, "must be larger");
177 }
178
179 // ------------------------------------------------------------------
180 // ciTypeFlow::JsrSet::remove_jsr_record
181 //
182 // Remove the JsrRecord with the given return address from the JsrSet.
183 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
184 int len = size();
185 for (int i = 0; i < len; i++) {
186 if (record_at(i)->return_address() == return_address) {
187 // We have found the proper entry. Remove it from the
188 // JsrSet and exit.
189 for (int j = i + 1; j < len ; j++) {
190 _set.at_put(j - 1, _set.at(j));
191 }
192 _set.trunc_to(len - 1);
193 assert(size() == len-1, "must be smaller");
194 return;
195 }
196 }
197 assert(false, "verify: returning from invalid subroutine");
198 }
199
200 // ------------------------------------------------------------------
201 // ciTypeFlow::JsrSet::apply_control
202 //
203 // Apply the effect of a control-flow bytecode on the JsrSet. The
204 // only bytecodes that modify the JsrSet are jsr and ret.
205 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
206 ciBytecodeStream* str,
207 ciTypeFlow::StateVector* state) {
208 Bytecodes::Code code = str->cur_bc();
209 if (code == Bytecodes::_jsr) {
210 JsrRecord* record =
211 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
212 insert_jsr_record(record);
213 } else if (code == Bytecodes::_jsr_w) {
214 JsrRecord* record =
215 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
216 insert_jsr_record(record);
217 } else if (code == Bytecodes::_ret) {
218 Cell local = state->local(str->get_index());
219 ciType* return_address = state->type_at(local);
220 assert(return_address->is_return_address(), "verify: wrong type");
221 if (size() == 0) {
222 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
223 // This can happen when a loop is inside a finally clause (4614060).
224 analyzer->record_failure("OSR in finally clause");
225 return;
226 }
227 remove_jsr_record(return_address->as_return_address()->bci());
228 }
229 }
230
231 #ifndef PRODUCT
232 // ------------------------------------------------------------------
233 // ciTypeFlow::JsrSet::print_on
234 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
235 st->print("{ ");
236 int num_elements = size();
237 if (num_elements > 0) {
238 int i = 0;
239 for( ; i < num_elements - 1; i++) {
240 _set.at(i)->print_on(st);
241 st->print(", ");
242 }
243 _set.at(i)->print_on(st);
244 st->print(" ");
245 }
246 st->print("}");
247 }
248 #endif
249
250 // ciTypeFlow::StateVector
251 //
252 // A StateVector summarizes the type information at some point in
253 // the program.
254
255 // ------------------------------------------------------------------
256 // ciTypeFlow::StateVector::type_meet
257 //
258 // Meet two types.
259 //
260 // The semi-lattice of types use by this analysis are modeled on those
261 // of the verifier. The lattice is as follows:
262 //
263 // top_type() >= all non-extremal types >= bottom_type
264 // and
265 // Every primitive type is comparable only with itself. The meet of
266 // reference types is determined by their kind: instance class,
267 // interface, or array class. The meet of two types of the same
268 // kind is their least common ancestor. The meet of two types of
269 // different kinds is always java.lang.Object.
270 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
271 assert(t1 != t2, "checked in caller");
272 if (t1->equals(top_type())) {
273 return t2;
274 } else if (t2->equals(top_type())) {
275 return t1;
276 }
277 // Unwrap after saving nullness information and handling top meets
278 assert(t1->is_early_larval() == t2->is_early_larval(), "States should be compatible.");
279 bool is_early_larval = t1->is_early_larval();
280 bool null_free1 = t1->is_null_free();
281 bool null_free2 = t2->is_null_free();
282 if (t1->unwrap() == t2->unwrap() && null_free1 == null_free2) {
283 return t1;
284 }
285 t1 = t1->unwrap();
286 t2 = t2->unwrap();
287
288 if (t1->is_primitive_type() || t2->is_primitive_type()) {
289 // Special case null_type. null_type meet any reference type T
290 // is T. null_type meet null_type is null_type.
291 if (t1->equals(null_type())) {
292 if (!t2->is_primitive_type() || t2->equals(null_type())) {
293 return t2;
294 }
295 } else if (t2->equals(null_type())) {
296 if (!t1->is_primitive_type()) {
297 return t1;
298 }
299 }
300
301 // At least one of the two types is a non-top primitive type.
302 // The other type is not equal to it. Fall to bottom.
303 return bottom_type();
304 }
305
306 // Both types are non-top non-primitive types. That is,
307 // both types are either instanceKlasses or arrayKlasses.
308 ciKlass* object_klass = analyzer->env()->Object_klass();
309 ciKlass* k1 = t1->as_klass();
310 ciKlass* k2 = t2->as_klass();
311 if (k1->equals(object_klass) || k2->equals(object_klass)) {
312 return object_klass;
313 } else if (!k1->is_loaded() || !k2->is_loaded()) {
314 // Unloaded classes fall to java.lang.Object at a merge.
315 return object_klass;
316 } else if (k1->is_interface() != k2->is_interface()) {
317 // When an interface meets a non-interface, we get Object;
318 // This is what the verifier does.
319 return object_klass;
320 } else if (k1->is_array_klass() || k2->is_array_klass()) {
321 // When an array meets a non-array, we get Object.
322 // When (obj/flat)Array meets typeArray, we also get Object.
323 // And when typeArray meets different typeArray, we again get Object.
324 // But when (obj/flat)Array meets (obj/flat)Array, we look carefully at element types.
325 if ((k1->is_obj_array_klass() || k1->is_flat_array_klass()) &&
326 (k2->is_obj_array_klass() || k2->is_flat_array_klass())) {
327 ciType* elem1 = k1->as_array_klass()->element_klass();
328 ciType* elem2 = k2->as_array_klass()->element_klass();
329 ciType* elem = elem1;
330 if (elem1 != elem2) {
331 elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
332 }
333 // Do an easy shortcut if one type is a super of the other.
334 if (elem == elem1 && !elem->is_inlinetype()) {
335 assert(k1 == ciArrayKlass::make(elem), "shortcut is OK");
336 return k1;
337 } else if (elem == elem2 && !elem->is_inlinetype()) {
338 assert(k2 == ciArrayKlass::make(elem), "shortcut is OK");
339 return k2;
340 } else {
341 return ciArrayKlass::make(elem);
342 }
343 } else {
344 return object_klass;
345 }
346 } else {
347 // Must be two plain old instance klasses.
348 assert(k1->is_instance_klass(), "previous cases handle non-instances");
349 assert(k2->is_instance_klass(), "previous cases handle non-instances");
350 ciType* result = k1->least_common_ancestor(k2);
351 if (null_free1 && null_free2 && result->is_inlinetype()) {
352 result = analyzer->mark_as_null_free(result);
353 }
354 if (is_early_larval) {
355 result = analyzer->mark_as_early_larval(result);
356 }
357 return result;
358 }
359 }
360
361
362 // ------------------------------------------------------------------
363 // ciTypeFlow::StateVector::StateVector
364 //
365 // Build a new state vector
366 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
367 _outer = analyzer;
368 _stack_size = -1;
369 _monitor_count = -1;
370 // Allocate the _types array
371 int max_cells = analyzer->max_cells();
372 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
373 for (int i=0; i<max_cells; i++) {
374 _types[i] = top_type();
375 }
376 _trap_bci = -1;
377 _trap_index = 0;
378 _def_locals.clear();
379 }
380
381
382 // ------------------------------------------------------------------
383 // ciTypeFlow::get_start_state
384 //
385 // Set this vector to the method entry state.
386 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
387 StateVector* state = new StateVector(this);
388 if (is_osr_flow()) {
389 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
390 if (non_osr_flow->failing()) {
391 record_failure(non_osr_flow->failure_reason());
392 return nullptr;
393 }
394 JsrSet* jsrs = new JsrSet(4);
395 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
396 if (non_osr_block == nullptr) {
397 record_failure("cannot reach OSR point");
398 return nullptr;
399 }
400 // load up the non-OSR state at this point
401 non_osr_block->copy_state_into(state);
402 int non_osr_start = non_osr_block->start();
403 if (non_osr_start != start_bci()) {
404 // must flow forward from it
405 if (CITraceTypeFlow) {
406 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
407 }
408 Block* block = block_at(non_osr_start, jsrs);
409 assert(block->limit() == start_bci(), "must flow forward to start");
410 flow_block(block, state, jsrs);
411 }
412 return state;
413 // Note: The code below would be an incorrect for an OSR flow,
414 // even if it were possible for an OSR entry point to be at bci zero.
415 }
416 // "Push" the method signature into the first few locals.
417 state->set_stack_size(-max_locals());
418 if (!method()->is_static()) {
419 ciType* holder = method()->holder();
420 if (method()->is_object_constructor()) {
421 if (holder->is_inlinetype() || (holder->is_instance_klass() && !holder->as_instance_klass()->flags().is_identity())) {
422 // The receiver is early larval (so also null-free)
423 holder = mark_as_early_larval(holder);
424 }
425 } else {
426 if (holder->is_inlinetype()) {
427 // The receiver is null-free
428 holder = mark_as_null_free(holder);
429 }
430 }
431 state->push(holder);
432 assert(state->tos() == state->local(0), "");
433 }
434 for (ciSignatureStream str(method()->signature());
435 !str.at_return_type();
436 str.next()) {
437 state->push_translate(str.type());
438 }
439 // Set the rest of the locals to bottom.
440 assert(state->stack_size() <= 0, "stack size should not be strictly positive");
441 while (state->stack_size() < 0) {
442 state->push(state->bottom_type());
443 }
444 // Lock an object, if necessary.
445 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
446 return state;
447 }
448
449 // ------------------------------------------------------------------
450 // ciTypeFlow::StateVector::copy_into
451 //
452 // Copy our value into some other StateVector
453 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
454 const {
455 copy->set_stack_size(stack_size());
456 copy->set_monitor_count(monitor_count());
457 Cell limit = limit_cell();
458 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
459 copy->set_type_at(c, type_at(c));
460 }
461 }
462
463 // ------------------------------------------------------------------
464 // ciTypeFlow::StateVector::meet
465 //
466 // Meets this StateVector with another, destructively modifying this
467 // one. Returns true if any modification takes place.
468 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
469 if (monitor_count() == -1) {
470 set_monitor_count(incoming->monitor_count());
471 }
472 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
473
474 if (stack_size() == -1) {
475 set_stack_size(incoming->stack_size());
476 Cell limit = limit_cell();
477 #ifdef ASSERT
478 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
479 assert(type_at(c) == top_type(), "");
480 } }
481 #endif
482 // Make a simple copy of the incoming state.
483 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
484 set_type_at(c, incoming->type_at(c));
485 }
486 return true; // it is always different the first time
487 }
488 #ifdef ASSERT
489 if (stack_size() != incoming->stack_size()) {
490 _outer->method()->print_codes();
491 tty->print_cr("!!!! Stack size conflict");
492 tty->print_cr("Current state:");
493 print_on(tty);
494 tty->print_cr("Incoming state:");
495 ((StateVector*)incoming)->print_on(tty);
496 }
497 #endif
498 assert(stack_size() == incoming->stack_size(), "sanity");
499
500 bool different = false;
501 Cell limit = limit_cell();
502 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
503 ciType* t1 = type_at(c);
504 ciType* t2 = incoming->type_at(c);
505 if (!t1->equals(t2)) {
506 ciType* new_type = type_meet(t1, t2);
507 if (!t1->equals(new_type)) {
508 set_type_at(c, new_type);
509 different = true;
510 }
511 }
512 }
513 return different;
514 }
515
516 // ------------------------------------------------------------------
517 // ciTypeFlow::StateVector::meet_exception
518 //
519 // Meets this StateVector with another, destructively modifying this
520 // one. The incoming state is coming via an exception. Returns true
521 // if any modification takes place.
522 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
523 const ciTypeFlow::StateVector* incoming) {
524 if (monitor_count() == -1) {
525 set_monitor_count(incoming->monitor_count());
526 }
527 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
528
529 if (stack_size() == -1) {
530 set_stack_size(1);
531 }
532
533 assert(stack_size() == 1, "must have one-element stack");
534
535 bool different = false;
536
537 // Meet locals from incoming array.
538 Cell limit = local_limit_cell();
539 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
540 ciType* t1 = type_at(c);
541 ciType* t2 = incoming->type_at(c);
542 if (!t1->equals(t2)) {
543 ciType* new_type = type_meet(t1, t2);
544 if (!t1->equals(new_type)) {
545 set_type_at(c, new_type);
546 different = true;
547 }
548 }
549 }
550
551 // Handle stack separately. When an exception occurs, the
552 // only stack entry is the exception instance.
553 ciType* tos_type = type_at_tos();
554 if (!tos_type->equals(exc)) {
555 ciType* new_type = type_meet(tos_type, exc);
556 if (!tos_type->equals(new_type)) {
557 set_type_at_tos(new_type);
558 different = true;
559 }
560 }
561
562 return different;
563 }
564
565 // ------------------------------------------------------------------
566 // ciTypeFlow::StateVector::push_translate
567 void ciTypeFlow::StateVector::push_translate(ciType* type) {
568 BasicType basic_type = type->basic_type();
569 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
570 basic_type == T_BYTE || basic_type == T_SHORT) {
571 push_int();
572 } else {
573 push(type);
574 if (type->is_two_word()) {
575 push(half_type(type));
576 }
577 }
578 }
579
580 // ------------------------------------------------------------------
581 // ciTypeFlow::StateVector::do_aload
582 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
583 pop_int();
584 ciArrayKlass* array_klass = pop_objOrFlatArray();
585 if (array_klass == nullptr) {
586 // Did aload on a null reference; push a null and ignore the exception.
587 // This instruction will never continue normally. All we have to do
588 // is report a value that will meet correctly with any downstream
589 // reference types on paths that will truly be executed. This null type
590 // meets with any reference type to yield that same reference type.
591 // (The compiler will generate an unconditional exception here.)
592 push(null_type());
593 return;
594 }
595 if (!array_klass->is_loaded()) {
596 // Only fails for some -Xcomp runs
597 trap(str, array_klass,
598 Deoptimization::make_trap_request
599 (Deoptimization::Reason_unloaded,
600 Deoptimization::Action_reinterpret));
601 return;
602 }
603 ciKlass* element_klass = array_klass->element_klass();
604 // TODO 8350865 Can we check that array_klass is null_free and use mark_as_null_free on the result here?
605 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
606 Untested("unloaded array element class in ciTypeFlow");
607 trap(str, element_klass,
608 Deoptimization::make_trap_request
609 (Deoptimization::Reason_unloaded,
610 Deoptimization::Action_reinterpret));
611 } else {
612 push_object(element_klass);
613 }
614 }
615
616
617 // ------------------------------------------------------------------
618 // ciTypeFlow::StateVector::do_checkcast
619 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
620 bool will_link;
621 ciKlass* klass = str->get_klass(will_link);
622 if (!will_link) {
623 // VM's interpreter will not load 'klass' if object is nullptr.
624 // Type flow after this block may still be needed in two situations:
625 // 1) C2 uses do_null_assert() and continues compilation for later blocks
626 // 2) C2 does an OSR compile in a later block (see bug 4778368).
627 pop_object();
628 do_null_assert(klass);
629 } else {
630 ciType* type = pop_value();
631 type = type->unwrap();
632 if (type->is_loaded() && klass->is_loaded() &&
633 type != klass && type->is_subtype_of(klass)) {
634 // Useless cast, propagate more precise type of object
635 klass = type->as_klass();
636 }
637 push_object(klass);
638 }
639 }
640
641 // ------------------------------------------------------------------
642 // ciTypeFlow::StateVector::do_getfield
643 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
644 // could add assert here for type of object.
645 pop_object();
646 do_getstatic(str);
647 }
648
649 // ------------------------------------------------------------------
650 // ciTypeFlow::StateVector::do_getstatic
651 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
652 bool will_link;
653 ciField* field = str->get_field(will_link);
654 if (!will_link) {
655 trap(str, field->holder(), str->get_field_holder_index());
656 } else {
657 ciType* field_type = field->type();
658 if (field->is_static() && field->is_null_free() &&
659 !field_type->as_instance_klass()->is_initialized()) {
660 // Deoptimize if we load from a static field with an uninitialized inline type
661 // because we need to throw an exception if initialization of the type failed.
662 trap(str, field_type->as_klass(),
663 Deoptimization::make_trap_request
664 (Deoptimization::Reason_unloaded,
665 Deoptimization::Action_reinterpret));
666 return;
667 } else if (!field_type->is_loaded()) {
668 // Normally, we need the field's type to be loaded if we are to
669 // do anything interesting with its value.
670 // We used to do this: trap(str, str->get_field_signature_index());
671 //
672 // There is one good reason not to trap here. Execution can
673 // get past this "getfield" or "getstatic" if the value of
674 // the field is null. As long as the value is null, the class
675 // does not need to be loaded! The compiler must assume that
676 // the value of the unloaded class reference is null; if the code
677 // ever sees a non-null value, loading has occurred.
678 //
679 // This actually happens often enough to be annoying. If the
680 // compiler throws an uncommon trap at this bytecode, you can
681 // get an endless loop of recompilations, when all the code
682 // needs to do is load a series of null values. Also, a trap
683 // here can make an OSR entry point unreachable, triggering the
684 // assert on non_osr_block in ciTypeFlow::get_start_state.
685 // (See bug 4379915.)
686 do_null_assert(field_type->as_klass());
687 } else {
688 if (field->is_null_free()) {
689 field_type = outer()->mark_as_null_free(field_type);
690 }
691 push_translate(field_type);
692 }
693 }
694 }
695
696 // ------------------------------------------------------------------
697 // ciTypeFlow::StateVector::do_invoke
698 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
699 bool has_receiver) {
700 bool will_link;
701 ciSignature* declared_signature = nullptr;
702 ciMethod* callee = str->get_method(will_link, &declared_signature);
703 assert(declared_signature != nullptr, "cannot be null");
704 if (!will_link) {
705 // We weren't able to find the method.
706 if (str->cur_bc() == Bytecodes::_invokedynamic) {
707 trap(str, nullptr,
708 Deoptimization::make_trap_request
709 (Deoptimization::Reason_uninitialized,
710 Deoptimization::Action_reinterpret));
711 } else {
712 ciKlass* unloaded_holder = callee->holder();
713 trap(str, unloaded_holder, str->get_method_holder_index());
714 }
715 } else {
716 // We are using the declared signature here because it might be
717 // different from the callee signature (Cf. invokedynamic and
718 // invokehandle).
719 ciSignatureStream sigstr(declared_signature);
720 const int arg_size = declared_signature->size();
721 const int stack_base = stack_size() - arg_size;
722 int i = 0;
723 for( ; !sigstr.at_return_type(); sigstr.next()) {
724 ciType* type = sigstr.type();
725 ciType* stack_type = type_at(stack(stack_base + i++));
726 // Do I want to check this type?
727 // assert(stack_type->is_subtype_of(type), "bad type for field value");
728 if (type->is_two_word()) {
729 ciType* stack_type2 = type_at(stack(stack_base + i++));
730 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
731 }
732 }
733 assert(arg_size == i, "must match");
734 for (int j = 0; j < arg_size; j++) {
735 pop();
736 }
737 if (has_receiver) {
738 if (type_at_tos()->is_early_larval()) {
739 // Call with larval receiver accepted by verifier
740 // => this is <init> and the receiver is no longer larval after that.
741 Cell limit = limit_cell();
742 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
743 if (type_at(c)->ident() == type_at_tos()->ident()) {
744 assert(type_at(c) == type_at_tos(), "Sin! Abomination!");
745 set_type_at(c, type_at_tos()->unwrap());
746 }
747 }
748 }
749 pop_object();
750 }
751 assert(!sigstr.is_done(), "must have return type");
752 ciType* return_type = sigstr.type();
753 if (!return_type->is_void()) {
754 if (!return_type->is_loaded()) {
755 // As in do_getstatic(), generally speaking, we need the return type to
756 // be loaded if we are to do anything interesting with its value.
757 // We used to do this: trap(str, str->get_method_signature_index());
758 //
759 // We do not trap here since execution can get past this invoke if
760 // the return value is null. As long as the value is null, the class
761 // does not need to be loaded! The compiler must assume that
762 // the value of the unloaded class reference is null; if the code
763 // ever sees a non-null value, loading has occurred.
764 //
765 // See do_getstatic() for similar explanation, as well as bug 4684993.
766 do_null_assert(return_type->as_klass());
767 } else {
768 push_translate(return_type);
769 }
770 }
771 }
772 }
773
774 // ------------------------------------------------------------------
775 // ciTypeFlow::StateVector::do_jsr
776 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
777 push(ciReturnAddress::make(str->next_bci()));
778 }
779
780 // ------------------------------------------------------------------
781 // ciTypeFlow::StateVector::do_ldc
782 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
783 if (str->is_in_error()) {
784 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unhandled,
785 Deoptimization::Action_none));
786 return;
787 }
788 ciConstant con = str->get_constant();
789 if (con.is_valid()) {
790 int cp_index = str->get_constant_pool_index();
791 if (!con.is_loaded()) {
792 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unloaded,
793 Deoptimization::Action_reinterpret,
794 cp_index));
795 return;
796 }
797 BasicType basic_type = str->get_basic_type_for_constant_at(cp_index);
798 if (is_reference_type(basic_type)) {
799 ciObject* obj = con.as_object();
800 if (obj->is_null_object()) {
801 push_null();
802 } else {
803 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
804 ciType* type = obj->klass();
805 if (type->is_inlinetype()) {
806 type = outer()->mark_as_null_free(type);
807 }
808 push(type);
809 }
810 } else {
811 assert(basic_type == con.basic_type() || con.basic_type() == T_OBJECT,
812 "not a boxed form: %s vs %s", type2name(basic_type), type2name(con.basic_type()));
813 push_translate(ciType::make(basic_type));
814 }
815 } else {
816 // OutOfMemoryError in the CI while loading a String constant.
817 push_null();
818 outer()->record_failure("ldc did not link");
819 }
820 }
821
822 // ------------------------------------------------------------------
823 // ciTypeFlow::StateVector::do_multianewarray
824 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
825 int dimensions = str->get_dimensions();
826 bool will_link;
827 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
828 if (!will_link) {
829 trap(str, array_klass, str->get_klass_index());
830 } else {
831 for (int i = 0; i < dimensions; i++) {
832 pop_int();
833 }
834 push_object(array_klass);
835 }
836 }
837
838 // ------------------------------------------------------------------
839 // ciTypeFlow::StateVector::do_new
840 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
841 bool will_link;
842 ciKlass* klass = str->get_klass(will_link);
843 if (!will_link || str->is_unresolved_klass()) {
844 trap(str, klass, str->get_klass_index());
845 } else {
846 if (klass->is_inlinetype()) {
847 push(outer()->mark_as_early_larval(klass));
848 return;
849 }
850 push_object(klass);
851 }
852 }
853
854 // ------------------------------------------------------------------
855 // ciTypeFlow::StateVector::do_newarray
856 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
857 pop_int();
858 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
859 push_object(klass);
860 }
861
862 // ------------------------------------------------------------------
863 // ciTypeFlow::StateVector::do_putfield
864 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
865 do_putstatic(str);
866 if (_trap_bci != -1) return; // unloaded field holder, etc.
867 // could add assert here for type of object.
868 pop_object();
869 }
870
871 // ------------------------------------------------------------------
872 // ciTypeFlow::StateVector::do_putstatic
873 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
874 bool will_link;
875 ciField* field = str->get_field(will_link);
876 if (!will_link) {
877 trap(str, field->holder(), str->get_field_holder_index());
878 } else {
879 ciType* field_type = field->type();
880 ciType* type = pop_value();
881 // Do I want to check this type?
882 // assert(type->is_subtype_of(field_type), "bad type for field value");
883 if (field_type->is_two_word()) {
884 ciType* type2 = pop_value();
885 assert(type2->is_two_word(), "must be 2nd half");
886 assert(type == half_type(type2), "must be 2nd half");
887 }
888 }
889 }
890
891 // ------------------------------------------------------------------
892 // ciTypeFlow::StateVector::do_ret
893 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
894 Cell index = local(str->get_index());
895
896 ciType* address = type_at(index);
897 assert(address->is_return_address(), "bad return address");
898 set_type_at(index, bottom_type());
899 }
900
901 // ------------------------------------------------------------------
902 // ciTypeFlow::StateVector::trap
903 //
904 // Stop interpretation of this path with a trap.
905 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
906 _trap_bci = str->cur_bci();
907 _trap_index = index;
908
909 // Log information about this trap:
910 CompileLog* log = outer()->env()->log();
911 if (log != nullptr) {
912 int mid = log->identify(outer()->method());
913 int kid = (klass == nullptr)? -1: log->identify(klass);
914 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
915 char buf[100];
916 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
917 index));
918 if (kid >= 0)
919 log->print(" klass='%d'", kid);
920 log->end_elem();
921 }
922 }
923
924 // ------------------------------------------------------------------
925 // ciTypeFlow::StateVector::do_null_assert
926 // Corresponds to graphKit::do_null_assert.
927 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
928 if (unloaded_klass->is_loaded()) {
929 // We failed to link, but we can still compute with this class,
930 // since it is loaded somewhere. The compiler will uncommon_trap
931 // if the object is not null, but the typeflow pass can not assume
932 // that the object will be null, otherwise it may incorrectly tell
933 // the parser that an object is known to be null. 4761344, 4807707
934 push_object(unloaded_klass);
935 } else {
936 // The class is not loaded anywhere. It is safe to model the
937 // null in the typestates, because we can compile in a null check
938 // which will deoptimize us if someone manages to load the
939 // class later.
940 push_null();
941 }
942 }
943
944
945 // ------------------------------------------------------------------
946 // ciTypeFlow::StateVector::apply_one_bytecode
947 //
948 // Apply the effect of one bytecode to this StateVector
949 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
950 _trap_bci = -1;
951 _trap_index = 0;
952
953 if (CITraceTypeFlow) {
954 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
955 Bytecodes::name(str->cur_bc()));
956 }
957
958 switch(str->cur_bc()) {
959 case Bytecodes::_aaload: do_aload(str); break;
960
961 case Bytecodes::_aastore:
962 {
963 pop_object();
964 pop_int();
965 pop_objOrFlatArray();
966 break;
967 }
968 case Bytecodes::_aconst_null:
969 {
970 push_null();
971 break;
972 }
973 case Bytecodes::_aload: load_local_object(str->get_index()); break;
974 case Bytecodes::_aload_0: load_local_object(0); break;
975 case Bytecodes::_aload_1: load_local_object(1); break;
976 case Bytecodes::_aload_2: load_local_object(2); break;
977 case Bytecodes::_aload_3: load_local_object(3); break;
978
979 case Bytecodes::_anewarray:
980 {
981 pop_int();
982 bool will_link;
983 ciKlass* element_klass = str->get_klass(will_link);
984 if (!will_link) {
985 trap(str, element_klass, str->get_klass_index());
986 } else {
987 push_object(ciArrayKlass::make(element_klass));
988 }
989 break;
990 }
991 case Bytecodes::_areturn:
992 case Bytecodes::_ifnonnull:
993 case Bytecodes::_ifnull:
994 {
995 pop_object();
996 break;
997 }
998 case Bytecodes::_monitorenter:
999 {
1000 pop_object();
1001 set_monitor_count(monitor_count() + 1);
1002 break;
1003 }
1004 case Bytecodes::_monitorexit:
1005 {
1006 pop_object();
1007 assert(monitor_count() > 0, "must be a monitor to exit from");
1008 set_monitor_count(monitor_count() - 1);
1009 break;
1010 }
1011 case Bytecodes::_arraylength:
1012 {
1013 pop_array();
1014 push_int();
1015 break;
1016 }
1017 case Bytecodes::_astore: store_local_object(str->get_index()); break;
1018 case Bytecodes::_astore_0: store_local_object(0); break;
1019 case Bytecodes::_astore_1: store_local_object(1); break;
1020 case Bytecodes::_astore_2: store_local_object(2); break;
1021 case Bytecodes::_astore_3: store_local_object(3); break;
1022
1023 case Bytecodes::_athrow:
1024 {
1025 NEEDS_CLEANUP;
1026 pop_object();
1027 break;
1028 }
1029 case Bytecodes::_baload:
1030 case Bytecodes::_caload:
1031 case Bytecodes::_iaload:
1032 case Bytecodes::_saload:
1033 {
1034 pop_int();
1035 ciTypeArrayKlass* array_klass = pop_typeArray();
1036 // Put assert here for right type?
1037 push_int();
1038 break;
1039 }
1040 case Bytecodes::_bastore:
1041 case Bytecodes::_castore:
1042 case Bytecodes::_iastore:
1043 case Bytecodes::_sastore:
1044 {
1045 pop_int();
1046 pop_int();
1047 pop_typeArray();
1048 // assert here?
1049 break;
1050 }
1051 case Bytecodes::_bipush:
1052 case Bytecodes::_iconst_m1:
1053 case Bytecodes::_iconst_0:
1054 case Bytecodes::_iconst_1:
1055 case Bytecodes::_iconst_2:
1056 case Bytecodes::_iconst_3:
1057 case Bytecodes::_iconst_4:
1058 case Bytecodes::_iconst_5:
1059 case Bytecodes::_sipush:
1060 {
1061 push_int();
1062 break;
1063 }
1064 case Bytecodes::_checkcast: do_checkcast(str); break;
1065
1066 case Bytecodes::_d2f:
1067 {
1068 pop_double();
1069 push_float();
1070 break;
1071 }
1072 case Bytecodes::_d2i:
1073 {
1074 pop_double();
1075 push_int();
1076 break;
1077 }
1078 case Bytecodes::_d2l:
1079 {
1080 pop_double();
1081 push_long();
1082 break;
1083 }
1084 case Bytecodes::_dadd:
1085 case Bytecodes::_ddiv:
1086 case Bytecodes::_dmul:
1087 case Bytecodes::_drem:
1088 case Bytecodes::_dsub:
1089 {
1090 pop_double();
1091 pop_double();
1092 push_double();
1093 break;
1094 }
1095 case Bytecodes::_daload:
1096 {
1097 pop_int();
1098 ciTypeArrayKlass* array_klass = pop_typeArray();
1099 // Put assert here for right type?
1100 push_double();
1101 break;
1102 }
1103 case Bytecodes::_dastore:
1104 {
1105 pop_double();
1106 pop_int();
1107 pop_typeArray();
1108 // assert here?
1109 break;
1110 }
1111 case Bytecodes::_dcmpg:
1112 case Bytecodes::_dcmpl:
1113 {
1114 pop_double();
1115 pop_double();
1116 push_int();
1117 break;
1118 }
1119 case Bytecodes::_dconst_0:
1120 case Bytecodes::_dconst_1:
1121 {
1122 push_double();
1123 break;
1124 }
1125 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1126 case Bytecodes::_dload_0: load_local_double(0); break;
1127 case Bytecodes::_dload_1: load_local_double(1); break;
1128 case Bytecodes::_dload_2: load_local_double(2); break;
1129 case Bytecodes::_dload_3: load_local_double(3); break;
1130
1131 case Bytecodes::_dneg:
1132 {
1133 pop_double();
1134 push_double();
1135 break;
1136 }
1137 case Bytecodes::_dreturn:
1138 {
1139 pop_double();
1140 break;
1141 }
1142 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1143 case Bytecodes::_dstore_0: store_local_double(0); break;
1144 case Bytecodes::_dstore_1: store_local_double(1); break;
1145 case Bytecodes::_dstore_2: store_local_double(2); break;
1146 case Bytecodes::_dstore_3: store_local_double(3); break;
1147
1148 case Bytecodes::_dup:
1149 {
1150 push(type_at_tos());
1151 break;
1152 }
1153 case Bytecodes::_dup_x1:
1154 {
1155 ciType* value1 = pop_value();
1156 ciType* value2 = pop_value();
1157 push(value1);
1158 push(value2);
1159 push(value1);
1160 break;
1161 }
1162 case Bytecodes::_dup_x2:
1163 {
1164 ciType* value1 = pop_value();
1165 ciType* value2 = pop_value();
1166 ciType* value3 = pop_value();
1167 push(value1);
1168 push(value3);
1169 push(value2);
1170 push(value1);
1171 break;
1172 }
1173 case Bytecodes::_dup2:
1174 {
1175 ciType* value1 = pop_value();
1176 ciType* value2 = pop_value();
1177 push(value2);
1178 push(value1);
1179 push(value2);
1180 push(value1);
1181 break;
1182 }
1183 case Bytecodes::_dup2_x1:
1184 {
1185 ciType* value1 = pop_value();
1186 ciType* value2 = pop_value();
1187 ciType* value3 = pop_value();
1188 push(value2);
1189 push(value1);
1190 push(value3);
1191 push(value2);
1192 push(value1);
1193 break;
1194 }
1195 case Bytecodes::_dup2_x2:
1196 {
1197 ciType* value1 = pop_value();
1198 ciType* value2 = pop_value();
1199 ciType* value3 = pop_value();
1200 ciType* value4 = pop_value();
1201 push(value2);
1202 push(value1);
1203 push(value4);
1204 push(value3);
1205 push(value2);
1206 push(value1);
1207 break;
1208 }
1209 case Bytecodes::_f2d:
1210 {
1211 pop_float();
1212 push_double();
1213 break;
1214 }
1215 case Bytecodes::_f2i:
1216 {
1217 pop_float();
1218 push_int();
1219 break;
1220 }
1221 case Bytecodes::_f2l:
1222 {
1223 pop_float();
1224 push_long();
1225 break;
1226 }
1227 case Bytecodes::_fadd:
1228 case Bytecodes::_fdiv:
1229 case Bytecodes::_fmul:
1230 case Bytecodes::_frem:
1231 case Bytecodes::_fsub:
1232 {
1233 pop_float();
1234 pop_float();
1235 push_float();
1236 break;
1237 }
1238 case Bytecodes::_faload:
1239 {
1240 pop_int();
1241 ciTypeArrayKlass* array_klass = pop_typeArray();
1242 // Put assert here.
1243 push_float();
1244 break;
1245 }
1246 case Bytecodes::_fastore:
1247 {
1248 pop_float();
1249 pop_int();
1250 ciTypeArrayKlass* array_klass = pop_typeArray();
1251 // Put assert here.
1252 break;
1253 }
1254 case Bytecodes::_fcmpg:
1255 case Bytecodes::_fcmpl:
1256 {
1257 pop_float();
1258 pop_float();
1259 push_int();
1260 break;
1261 }
1262 case Bytecodes::_fconst_0:
1263 case Bytecodes::_fconst_1:
1264 case Bytecodes::_fconst_2:
1265 {
1266 push_float();
1267 break;
1268 }
1269 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1270 case Bytecodes::_fload_0: load_local_float(0); break;
1271 case Bytecodes::_fload_1: load_local_float(1); break;
1272 case Bytecodes::_fload_2: load_local_float(2); break;
1273 case Bytecodes::_fload_3: load_local_float(3); break;
1274
1275 case Bytecodes::_fneg:
1276 {
1277 pop_float();
1278 push_float();
1279 break;
1280 }
1281 case Bytecodes::_freturn:
1282 {
1283 pop_float();
1284 break;
1285 }
1286 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1287 case Bytecodes::_fstore_0: store_local_float(0); break;
1288 case Bytecodes::_fstore_1: store_local_float(1); break;
1289 case Bytecodes::_fstore_2: store_local_float(2); break;
1290 case Bytecodes::_fstore_3: store_local_float(3); break;
1291
1292 case Bytecodes::_getfield: do_getfield(str); break;
1293 case Bytecodes::_getstatic: do_getstatic(str); break;
1294
1295 case Bytecodes::_goto:
1296 case Bytecodes::_goto_w:
1297 case Bytecodes::_nop:
1298 case Bytecodes::_return:
1299 {
1300 // do nothing.
1301 break;
1302 }
1303 case Bytecodes::_i2b:
1304 case Bytecodes::_i2c:
1305 case Bytecodes::_i2s:
1306 case Bytecodes::_ineg:
1307 {
1308 pop_int();
1309 push_int();
1310 break;
1311 }
1312 case Bytecodes::_i2d:
1313 {
1314 pop_int();
1315 push_double();
1316 break;
1317 }
1318 case Bytecodes::_i2f:
1319 {
1320 pop_int();
1321 push_float();
1322 break;
1323 }
1324 case Bytecodes::_i2l:
1325 {
1326 pop_int();
1327 push_long();
1328 break;
1329 }
1330 case Bytecodes::_iadd:
1331 case Bytecodes::_iand:
1332 case Bytecodes::_idiv:
1333 case Bytecodes::_imul:
1334 case Bytecodes::_ior:
1335 case Bytecodes::_irem:
1336 case Bytecodes::_ishl:
1337 case Bytecodes::_ishr:
1338 case Bytecodes::_isub:
1339 case Bytecodes::_iushr:
1340 case Bytecodes::_ixor:
1341 {
1342 pop_int();
1343 pop_int();
1344 push_int();
1345 break;
1346 }
1347 case Bytecodes::_if_acmpeq:
1348 case Bytecodes::_if_acmpne:
1349 {
1350 pop_object();
1351 pop_object();
1352 break;
1353 }
1354 case Bytecodes::_if_icmpeq:
1355 case Bytecodes::_if_icmpge:
1356 case Bytecodes::_if_icmpgt:
1357 case Bytecodes::_if_icmple:
1358 case Bytecodes::_if_icmplt:
1359 case Bytecodes::_if_icmpne:
1360 {
1361 pop_int();
1362 pop_int();
1363 break;
1364 }
1365 case Bytecodes::_ifeq:
1366 case Bytecodes::_ifle:
1367 case Bytecodes::_iflt:
1368 case Bytecodes::_ifge:
1369 case Bytecodes::_ifgt:
1370 case Bytecodes::_ifne:
1371 case Bytecodes::_ireturn:
1372 case Bytecodes::_lookupswitch:
1373 case Bytecodes::_tableswitch:
1374 {
1375 pop_int();
1376 break;
1377 }
1378 case Bytecodes::_iinc:
1379 {
1380 int lnum = str->get_index();
1381 check_int(local(lnum));
1382 store_to_local(lnum);
1383 break;
1384 }
1385 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1386 case Bytecodes::_iload_0: load_local_int(0); break;
1387 case Bytecodes::_iload_1: load_local_int(1); break;
1388 case Bytecodes::_iload_2: load_local_int(2); break;
1389 case Bytecodes::_iload_3: load_local_int(3); break;
1390
1391 case Bytecodes::_instanceof:
1392 {
1393 // Check for uncommon trap:
1394 do_checkcast(str);
1395 pop_object();
1396 push_int();
1397 break;
1398 }
1399 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1400 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1401 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1402 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1403 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1404
1405 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1406 case Bytecodes::_istore_0: store_local_int(0); break;
1407 case Bytecodes::_istore_1: store_local_int(1); break;
1408 case Bytecodes::_istore_2: store_local_int(2); break;
1409 case Bytecodes::_istore_3: store_local_int(3); break;
1410
1411 case Bytecodes::_jsr:
1412 case Bytecodes::_jsr_w: do_jsr(str); break;
1413
1414 case Bytecodes::_l2d:
1415 {
1416 pop_long();
1417 push_double();
1418 break;
1419 }
1420 case Bytecodes::_l2f:
1421 {
1422 pop_long();
1423 push_float();
1424 break;
1425 }
1426 case Bytecodes::_l2i:
1427 {
1428 pop_long();
1429 push_int();
1430 break;
1431 }
1432 case Bytecodes::_ladd:
1433 case Bytecodes::_land:
1434 case Bytecodes::_ldiv:
1435 case Bytecodes::_lmul:
1436 case Bytecodes::_lor:
1437 case Bytecodes::_lrem:
1438 case Bytecodes::_lsub:
1439 case Bytecodes::_lxor:
1440 {
1441 pop_long();
1442 pop_long();
1443 push_long();
1444 break;
1445 }
1446 case Bytecodes::_laload:
1447 {
1448 pop_int();
1449 ciTypeArrayKlass* array_klass = pop_typeArray();
1450 // Put assert here for right type?
1451 push_long();
1452 break;
1453 }
1454 case Bytecodes::_lastore:
1455 {
1456 pop_long();
1457 pop_int();
1458 pop_typeArray();
1459 // assert here?
1460 break;
1461 }
1462 case Bytecodes::_lcmp:
1463 {
1464 pop_long();
1465 pop_long();
1466 push_int();
1467 break;
1468 }
1469 case Bytecodes::_lconst_0:
1470 case Bytecodes::_lconst_1:
1471 {
1472 push_long();
1473 break;
1474 }
1475 case Bytecodes::_ldc:
1476 case Bytecodes::_ldc_w:
1477 case Bytecodes::_ldc2_w:
1478 {
1479 do_ldc(str);
1480 break;
1481 }
1482
1483 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1484 case Bytecodes::_lload_0: load_local_long(0); break;
1485 case Bytecodes::_lload_1: load_local_long(1); break;
1486 case Bytecodes::_lload_2: load_local_long(2); break;
1487 case Bytecodes::_lload_3: load_local_long(3); break;
1488
1489 case Bytecodes::_lneg:
1490 {
1491 pop_long();
1492 push_long();
1493 break;
1494 }
1495 case Bytecodes::_lreturn:
1496 {
1497 pop_long();
1498 break;
1499 }
1500 case Bytecodes::_lshl:
1501 case Bytecodes::_lshr:
1502 case Bytecodes::_lushr:
1503 {
1504 pop_int();
1505 pop_long();
1506 push_long();
1507 break;
1508 }
1509 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1510 case Bytecodes::_lstore_0: store_local_long(0); break;
1511 case Bytecodes::_lstore_1: store_local_long(1); break;
1512 case Bytecodes::_lstore_2: store_local_long(2); break;
1513 case Bytecodes::_lstore_3: store_local_long(3); break;
1514
1515 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1516
1517 case Bytecodes::_new: do_new(str); break;
1518
1519 case Bytecodes::_newarray: do_newarray(str); break;
1520
1521 case Bytecodes::_pop:
1522 {
1523 pop();
1524 break;
1525 }
1526 case Bytecodes::_pop2:
1527 {
1528 pop();
1529 pop();
1530 break;
1531 }
1532
1533 case Bytecodes::_putfield: do_putfield(str); break;
1534 case Bytecodes::_putstatic: do_putstatic(str); break;
1535
1536 case Bytecodes::_ret: do_ret(str); break;
1537
1538 case Bytecodes::_swap:
1539 {
1540 ciType* value1 = pop_value();
1541 ciType* value2 = pop_value();
1542 push(value1);
1543 push(value2);
1544 break;
1545 }
1546
1547 case Bytecodes::_wide:
1548 default:
1549 {
1550 // The iterator should skip this.
1551 ShouldNotReachHere();
1552 break;
1553 }
1554 }
1555
1556 if (CITraceTypeFlow) {
1557 print_on(tty);
1558 }
1559
1560 return (_trap_bci != -1);
1561 }
1562
1563 #ifndef PRODUCT
1564 // ------------------------------------------------------------------
1565 // ciTypeFlow::StateVector::print_cell_on
1566 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1567 ciType* type = type_at(c)->unwrap();
1568 if (type == top_type()) {
1569 st->print("top");
1570 } else if (type == bottom_type()) {
1571 st->print("bottom");
1572 } else if (type == null_type()) {
1573 st->print("null");
1574 } else if (type == long2_type()) {
1575 st->print("long2");
1576 } else if (type == double2_type()) {
1577 st->print("double2");
1578 } else if (is_int(type)) {
1579 st->print("int");
1580 } else if (is_long(type)) {
1581 st->print("long");
1582 } else if (is_float(type)) {
1583 st->print("float");
1584 } else if (is_double(type)) {
1585 st->print("double");
1586 } else if (type->is_return_address()) {
1587 st->print("address(%d)", type->as_return_address()->bci());
1588 } else {
1589 if (type->is_klass()) {
1590 type->as_klass()->name()->print_symbol_on(st);
1591 } else {
1592 st->print("UNEXPECTED TYPE");
1593 type->print();
1594 }
1595 }
1596 }
1597
1598 // ------------------------------------------------------------------
1599 // ciTypeFlow::StateVector::print_on
1600 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1601 int num_locals = _outer->max_locals();
1602 int num_stack = stack_size();
1603 int num_monitors = monitor_count();
1604 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1605 if (num_stack >= 0) {
1606 int i;
1607 for (i = 0; i < num_locals; i++) {
1608 st->print(" local %2d : ", i);
1609 print_cell_on(st, local(i));
1610 st->cr();
1611 }
1612 for (i = 0; i < num_stack; i++) {
1613 st->print(" stack %2d : ", i);
1614 print_cell_on(st, stack(i));
1615 st->cr();
1616 }
1617 }
1618 }
1619 #endif
1620
1621
1622 // ------------------------------------------------------------------
1623 // ciTypeFlow::SuccIter::next
1624 //
1625 void ciTypeFlow::SuccIter::next() {
1626 int succ_ct = _pred->successors()->length();
1627 int next = _index + 1;
1628 if (next < succ_ct) {
1629 _index = next;
1630 _succ = _pred->successors()->at(next);
1631 return;
1632 }
1633 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1634 // Do not compile any code for unloaded exception types.
1635 // Following compiler passes are responsible for doing this also.
1636 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1637 if (exception_klass->is_loaded()) {
1638 _index = next;
1639 _succ = _pred->exceptions()->at(i);
1640 return;
1641 }
1642 next++;
1643 }
1644 _index = -1;
1645 _succ = nullptr;
1646 }
1647
1648 // ------------------------------------------------------------------
1649 // ciTypeFlow::SuccIter::set_succ
1650 //
1651 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1652 int succ_ct = _pred->successors()->length();
1653 if (_index < succ_ct) {
1654 _pred->successors()->at_put(_index, succ);
1655 } else {
1656 int idx = _index - succ_ct;
1657 _pred->exceptions()->at_put(idx, succ);
1658 }
1659 }
1660
1661 // ciTypeFlow::Block
1662 //
1663 // A basic block.
1664
1665 // ------------------------------------------------------------------
1666 // ciTypeFlow::Block::Block
1667 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1668 ciBlock *ciblk,
1669 ciTypeFlow::JsrSet* jsrs) : _predecessors(outer->arena(), 1, 0, nullptr) {
1670 _ciblock = ciblk;
1671 _exceptions = nullptr;
1672 _exc_klasses = nullptr;
1673 _successors = nullptr;
1674 _state = new (outer->arena()) StateVector(outer);
1675 JsrSet* new_jsrs =
1676 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1677 jsrs->copy_into(new_jsrs);
1678 _jsrs = new_jsrs;
1679 _next = nullptr;
1680 _on_work_list = false;
1681 _backedge_copy = false;
1682 _has_monitorenter = false;
1683 _trap_bci = -1;
1684 _trap_index = 0;
1685 df_init();
1686
1687 if (CITraceTypeFlow) {
1688 tty->print_cr(">> Created new block");
1689 print_on(tty);
1690 }
1691
1692 assert(this->outer() == outer, "outer link set up");
1693 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1694 }
1695
1696 // ------------------------------------------------------------------
1697 // ciTypeFlow::Block::df_init
1698 void ciTypeFlow::Block::df_init() {
1699 _pre_order = -1; assert(!has_pre_order(), "");
1700 _post_order = -1; assert(!has_post_order(), "");
1701 _loop = nullptr;
1702 _irreducible_loop_head = false;
1703 _irreducible_loop_secondary_entry = false;
1704 _rpo_next = nullptr;
1705 }
1706
1707 // ------------------------------------------------------------------
1708 // ciTypeFlow::Block::successors
1709 //
1710 // Get the successors for this Block.
1711 GrowableArray<ciTypeFlow::Block*>*
1712 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1713 ciTypeFlow::StateVector* state,
1714 ciTypeFlow::JsrSet* jsrs) {
1715 if (_successors == nullptr) {
1716 if (CITraceTypeFlow) {
1717 tty->print(">> Computing successors for block ");
1718 print_value_on(tty);
1719 tty->cr();
1720 }
1721
1722 ciTypeFlow* analyzer = outer();
1723 Arena* arena = analyzer->arena();
1724 Block* block = nullptr;
1725 bool has_successor = !has_trap() &&
1726 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1727 if (!has_successor) {
1728 _successors =
1729 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1730 // No successors
1731 } else if (control() == ciBlock::fall_through_bci) {
1732 assert(str->cur_bci() == limit(), "bad block end");
1733 // This block simply falls through to the next.
1734 _successors =
1735 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1736
1737 Block* block = analyzer->block_at(limit(), _jsrs);
1738 assert(_successors->length() == FALL_THROUGH, "");
1739 _successors->append(block);
1740 } else {
1741 int current_bci = str->cur_bci();
1742 int next_bci = str->next_bci();
1743 int branch_bci = -1;
1744 Block* target = nullptr;
1745 assert(str->next_bci() == limit(), "bad block end");
1746 // This block is not a simple fall-though. Interpret
1747 // the current bytecode to find our successors.
1748 switch (str->cur_bc()) {
1749 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1750 case Bytecodes::_iflt: case Bytecodes::_ifge:
1751 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1752 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1753 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1754 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1755 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1756 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1757 // Our successors are the branch target and the next bci.
1758 branch_bci = str->get_dest();
1759 _successors =
1760 new (arena) GrowableArray<Block*>(arena, 2, 0, nullptr);
1761 assert(_successors->length() == IF_NOT_TAKEN, "");
1762 _successors->append(analyzer->block_at(next_bci, jsrs));
1763 assert(_successors->length() == IF_TAKEN, "");
1764 _successors->append(analyzer->block_at(branch_bci, jsrs));
1765 break;
1766
1767 case Bytecodes::_goto:
1768 branch_bci = str->get_dest();
1769 _successors =
1770 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1771 assert(_successors->length() == GOTO_TARGET, "");
1772 _successors->append(analyzer->block_at(branch_bci, jsrs));
1773 break;
1774
1775 case Bytecodes::_jsr:
1776 branch_bci = str->get_dest();
1777 _successors =
1778 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1779 assert(_successors->length() == GOTO_TARGET, "");
1780 _successors->append(analyzer->block_at(branch_bci, jsrs));
1781 break;
1782
1783 case Bytecodes::_goto_w:
1784 case Bytecodes::_jsr_w:
1785 _successors =
1786 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1787 assert(_successors->length() == GOTO_TARGET, "");
1788 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1789 break;
1790
1791 case Bytecodes::_tableswitch: {
1792 Bytecode_tableswitch tableswitch(str);
1793
1794 int len = tableswitch.length();
1795 _successors =
1796 new (arena) GrowableArray<Block*>(arena, len+1, 0, nullptr);
1797 int bci = current_bci + tableswitch.default_offset();
1798 Block* block = analyzer->block_at(bci, jsrs);
1799 assert(_successors->length() == SWITCH_DEFAULT, "");
1800 _successors->append(block);
1801 while (--len >= 0) {
1802 int bci = current_bci + tableswitch.dest_offset_at(len);
1803 block = analyzer->block_at(bci, jsrs);
1804 assert(_successors->length() >= SWITCH_CASES, "");
1805 _successors->append_if_missing(block);
1806 }
1807 break;
1808 }
1809
1810 case Bytecodes::_lookupswitch: {
1811 Bytecode_lookupswitch lookupswitch(str);
1812
1813 int npairs = lookupswitch.number_of_pairs();
1814 _successors =
1815 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, nullptr);
1816 int bci = current_bci + lookupswitch.default_offset();
1817 Block* block = analyzer->block_at(bci, jsrs);
1818 assert(_successors->length() == SWITCH_DEFAULT, "");
1819 _successors->append(block);
1820 while(--npairs >= 0) {
1821 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1822 int bci = current_bci + pair.offset();
1823 Block* block = analyzer->block_at(bci, jsrs);
1824 assert(_successors->length() >= SWITCH_CASES, "");
1825 _successors->append_if_missing(block);
1826 }
1827 break;
1828 }
1829
1830 case Bytecodes::_athrow:
1831 case Bytecodes::_ireturn:
1832 case Bytecodes::_lreturn:
1833 case Bytecodes::_freturn:
1834 case Bytecodes::_dreturn:
1835 case Bytecodes::_areturn:
1836 case Bytecodes::_return:
1837 _successors =
1838 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1839 // No successors
1840 break;
1841
1842 case Bytecodes::_ret: {
1843 _successors =
1844 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1845
1846 Cell local = state->local(str->get_index());
1847 ciType* return_address = state->type_at(local);
1848 assert(return_address->is_return_address(), "verify: wrong type");
1849 int bci = return_address->as_return_address()->bci();
1850 assert(_successors->length() == GOTO_TARGET, "");
1851 _successors->append(analyzer->block_at(bci, jsrs));
1852 break;
1853 }
1854
1855 case Bytecodes::_wide:
1856 default:
1857 ShouldNotReachHere();
1858 break;
1859 }
1860 }
1861
1862 // Set predecessor information
1863 for (int i = 0; i < _successors->length(); i++) {
1864 Block* block = _successors->at(i);
1865 block->predecessors()->append(this);
1866 }
1867 }
1868 return _successors;
1869 }
1870
1871 // ------------------------------------------------------------------
1872 // ciTypeFlow::Block:compute_exceptions
1873 //
1874 // Compute the exceptional successors and types for this Block.
1875 void ciTypeFlow::Block::compute_exceptions() {
1876 assert(_exceptions == nullptr && _exc_klasses == nullptr, "repeat");
1877
1878 if (CITraceTypeFlow) {
1879 tty->print(">> Computing exceptions for block ");
1880 print_value_on(tty);
1881 tty->cr();
1882 }
1883
1884 ciTypeFlow* analyzer = outer();
1885 Arena* arena = analyzer->arena();
1886
1887 // Any bci in the block will do.
1888 ciExceptionHandlerStream str(analyzer->method(), start());
1889
1890 // Allocate our growable arrays.
1891 int exc_count = str.count();
1892 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, nullptr);
1893 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1894 0, nullptr);
1895
1896 for ( ; !str.is_done(); str.next()) {
1897 ciExceptionHandler* handler = str.handler();
1898 int bci = handler->handler_bci();
1899 ciInstanceKlass* klass = nullptr;
1900 if (bci == -1) {
1901 // There is no catch all. It is possible to exit the method.
1902 break;
1903 }
1904 if (handler->is_catch_all()) {
1905 klass = analyzer->env()->Throwable_klass();
1906 } else {
1907 klass = handler->catch_klass();
1908 }
1909 Block* block = analyzer->block_at(bci, _jsrs);
1910 _exceptions->append(block);
1911 block->predecessors()->append(this);
1912 _exc_klasses->append(klass);
1913 }
1914 }
1915
1916 // ------------------------------------------------------------------
1917 // ciTypeFlow::Block::set_backedge_copy
1918 // Use this only to make a pre-existing public block into a backedge copy.
1919 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1920 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1921 _backedge_copy = z;
1922 }
1923
1924 // Analogous to PhaseIdealLoop::is_in_irreducible_loop
1925 bool ciTypeFlow::Block::is_in_irreducible_loop() const {
1926 if (!outer()->has_irreducible_entry()) {
1927 return false; // No irreducible loop in method.
1928 }
1929 Loop* lp = loop(); // Innermost loop containing block.
1930 if (lp == nullptr) {
1931 assert(!is_post_visited(), "must have enclosing loop once post-visited");
1932 return false; // Not yet processed, so we do not know, yet.
1933 }
1934 // Walk all the way up the loop-tree, search for an irreducible loop.
1935 do {
1936 if (lp->is_irreducible()) {
1937 return true; // We are in irreducible loop.
1938 }
1939 if (lp->head()->pre_order() == 0) {
1940 return false; // Found root loop, terminate.
1941 }
1942 lp = lp->parent();
1943 } while (lp != nullptr);
1944 // We have "lp->parent() == nullptr", which happens only for infinite loops,
1945 // where no parent is attached to the loop. We did not find any irreducible
1946 // loop from this block out to lp. Thus lp only has one entry, and no exit
1947 // (it is infinite and reducible). We can always rewrite an infinite loop
1948 // that is nested inside other loops:
1949 // while(condition) { infinite_loop; }
1950 // with an equivalent program where the infinite loop is an outermost loop
1951 // that is not nested in any loop:
1952 // while(condition) { break; } infinite_loop;
1953 // Thus, we can understand lp as an outermost loop, and can terminate and
1954 // conclude: this block is in no irreducible loop.
1955 return false;
1956 }
1957
1958 // ------------------------------------------------------------------
1959 // ciTypeFlow::Block::is_clonable_exit
1960 //
1961 // At most 2 normal successors, one of which continues looping,
1962 // and all exceptional successors must exit.
1963 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1964 int normal_cnt = 0;
1965 int in_loop_cnt = 0;
1966 for (SuccIter iter(this); !iter.done(); iter.next()) {
1967 Block* succ = iter.succ();
1968 if (iter.is_normal_ctrl()) {
1969 if (++normal_cnt > 2) return false;
1970 if (lp->contains(succ->loop())) {
1971 if (++in_loop_cnt > 1) return false;
1972 }
1973 } else {
1974 if (lp->contains(succ->loop())) return false;
1975 }
1976 }
1977 return in_loop_cnt == 1;
1978 }
1979
1980 // ------------------------------------------------------------------
1981 // ciTypeFlow::Block::looping_succ
1982 //
1983 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1984 assert(successors()->length() <= 2, "at most 2 normal successors");
1985 for (SuccIter iter(this); !iter.done(); iter.next()) {
1986 Block* succ = iter.succ();
1987 if (lp->contains(succ->loop())) {
1988 return succ;
1989 }
1990 }
1991 return nullptr;
1992 }
1993
1994 #ifndef PRODUCT
1995 // ------------------------------------------------------------------
1996 // ciTypeFlow::Block::print_value_on
1997 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1998 if (has_pre_order()) st->print("#%-2d ", pre_order());
1999 if (has_rpo()) st->print("rpo#%-2d ", rpo());
2000 st->print("[%d - %d)", start(), limit());
2001 if (is_loop_head()) st->print(" lphd");
2002 if (is_in_irreducible_loop()) st->print(" in_irred");
2003 if (is_irreducible_loop_head()) st->print(" irred_head");
2004 if (is_irreducible_loop_secondary_entry()) st->print(" irred_entry");
2005 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
2006 if (is_backedge_copy()) st->print("/backedge_copy");
2007 }
2008
2009 // ------------------------------------------------------------------
2010 // ciTypeFlow::Block::print_on
2011 void ciTypeFlow::Block::print_on(outputStream* st) const {
2012 if ((Verbose || WizardMode) && (limit() >= 0)) {
2013 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
2014 outer()->method()->print_codes_on(start(), limit(), st);
2015 }
2016 st->print_cr(" ==================================================== ");
2017 st->print (" ");
2018 print_value_on(st);
2019 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
2020 if (loop() && loop()->parent() != nullptr) {
2021 st->print(" loops:");
2022 Loop* lp = loop();
2023 do {
2024 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
2025 if (lp->is_irreducible()) st->print("(ir)");
2026 lp = lp->parent();
2027 } while (lp->parent() != nullptr);
2028 }
2029 st->cr();
2030 _state->print_on(st);
2031 if (_successors == nullptr) {
2032 st->print_cr(" No successor information");
2033 } else {
2034 int num_successors = _successors->length();
2035 st->print_cr(" Successors : %d", num_successors);
2036 for (int i = 0; i < num_successors; i++) {
2037 Block* successor = _successors->at(i);
2038 st->print(" ");
2039 successor->print_value_on(st);
2040 st->cr();
2041 }
2042 }
2043 if (_predecessors.is_empty()) {
2044 st->print_cr(" No predecessor information");
2045 } else {
2046 int num_predecessors = _predecessors.length();
2047 st->print_cr(" Predecessors : %d", num_predecessors);
2048 for (int i = 0; i < num_predecessors; i++) {
2049 Block* predecessor = _predecessors.at(i);
2050 st->print(" ");
2051 predecessor->print_value_on(st);
2052 st->cr();
2053 }
2054 }
2055 if (_exceptions == nullptr) {
2056 st->print_cr(" No exception information");
2057 } else {
2058 int num_exceptions = _exceptions->length();
2059 st->print_cr(" Exceptions : %d", num_exceptions);
2060 for (int i = 0; i < num_exceptions; i++) {
2061 Block* exc_succ = _exceptions->at(i);
2062 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
2063 st->print(" ");
2064 exc_succ->print_value_on(st);
2065 st->print(" -- ");
2066 exc_klass->name()->print_symbol_on(st);
2067 st->cr();
2068 }
2069 }
2070 if (has_trap()) {
2071 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2072 }
2073 st->print_cr(" ==================================================== ");
2074 }
2075 #endif
2076
2077 #ifndef PRODUCT
2078 // ------------------------------------------------------------------
2079 // ciTypeFlow::LocalSet::print_on
2080 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2081 st->print("{");
2082 for (int i = 0; i < max; i++) {
2083 if (test(i)) st->print(" %d", i);
2084 }
2085 if (limit > max) {
2086 st->print(" %d..%d ", max, limit);
2087 }
2088 st->print(" }");
2089 }
2090 #endif
2091
2092 // ciTypeFlow
2093 //
2094 // This is a pass over the bytecodes which computes the following:
2095 // basic block structure
2096 // interpreter type-states (a la the verifier)
2097
2098 // ------------------------------------------------------------------
2099 // ciTypeFlow::ciTypeFlow
2100 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2101 _env = env;
2102 _method = method;
2103 _has_irreducible_entry = false;
2104 _osr_bci = osr_bci;
2105 _failure_reason = nullptr;
2106 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2107 _work_list = nullptr;
2108
2109 int ciblock_count = _method->get_method_blocks()->num_blocks();
2110 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, ciblock_count);
2111 for (int i = 0; i < ciblock_count; i++) {
2112 _idx_to_blocklist[i] = nullptr;
2113 }
2114 _block_map = nullptr; // until all blocks are seen
2115 _jsr_records = nullptr;
2116 }
2117
2118 // ------------------------------------------------------------------
2119 // ciTypeFlow::work_list_next
2120 //
2121 // Get the next basic block from our work list.
2122 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2123 assert(!work_list_empty(), "work list must not be empty");
2124 Block* next_block = _work_list;
2125 _work_list = next_block->next();
2126 next_block->set_next(nullptr);
2127 next_block->set_on_work_list(false);
2128 return next_block;
2129 }
2130
2131 // ------------------------------------------------------------------
2132 // ciTypeFlow::add_to_work_list
2133 //
2134 // Add a basic block to our work list.
2135 // List is sorted by decreasing postorder sort (same as increasing RPO)
2136 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2137 assert(!block->is_on_work_list(), "must not already be on work list");
2138
2139 if (CITraceTypeFlow) {
2140 tty->print(">> Adding block ");
2141 block->print_value_on(tty);
2142 tty->print_cr(" to the work list : ");
2143 }
2144
2145 block->set_on_work_list(true);
2146
2147 // decreasing post order sort
2148
2149 Block* prev = nullptr;
2150 Block* current = _work_list;
2151 int po = block->post_order();
2152 while (current != nullptr) {
2153 if (!current->has_post_order() || po > current->post_order())
2154 break;
2155 prev = current;
2156 current = current->next();
2157 }
2158 if (prev == nullptr) {
2159 block->set_next(_work_list);
2160 _work_list = block;
2161 } else {
2162 block->set_next(current);
2163 prev->set_next(block);
2164 }
2165
2166 if (CITraceTypeFlow) {
2167 tty->cr();
2168 }
2169 }
2170
2171 // ------------------------------------------------------------------
2172 // ciTypeFlow::block_at
2173 //
2174 // Return the block beginning at bci which has a JsrSet compatible
2175 // with jsrs.
2176 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2177 // First find the right ciBlock.
2178 if (CITraceTypeFlow) {
2179 tty->print(">> Requesting block for %d/", bci);
2180 jsrs->print_on(tty);
2181 tty->cr();
2182 }
2183
2184 ciBlock* ciblk = _method->get_method_blocks()->block_containing(bci);
2185 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2186 Block* block = get_block_for(ciblk->index(), jsrs, option);
2187
2188 assert(block == nullptr? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2189
2190 if (CITraceTypeFlow) {
2191 if (block != nullptr) {
2192 tty->print(">> Found block ");
2193 block->print_value_on(tty);
2194 tty->cr();
2195 } else {
2196 tty->print_cr(">> No such block.");
2197 }
2198 }
2199
2200 return block;
2201 }
2202
2203 // ------------------------------------------------------------------
2204 // ciTypeFlow::make_jsr_record
2205 //
2206 // Make a JsrRecord for a given (entry, return) pair, if such a record
2207 // does not already exist.
2208 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2209 int return_address) {
2210 if (_jsr_records == nullptr) {
2211 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2212 2,
2213 0,
2214 nullptr);
2215 }
2216 JsrRecord* record = nullptr;
2217 int len = _jsr_records->length();
2218 for (int i = 0; i < len; i++) {
2219 JsrRecord* record = _jsr_records->at(i);
2220 if (record->entry_address() == entry_address &&
2221 record->return_address() == return_address) {
2222 return record;
2223 }
2224 }
2225
2226 record = new (arena()) JsrRecord(entry_address, return_address);
2227 _jsr_records->append(record);
2228 return record;
2229 }
2230
2231 // ------------------------------------------------------------------
2232 // ciTypeFlow::flow_exceptions
2233 //
2234 // Merge the current state into all exceptional successors at the
2235 // current point in the code.
2236 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2237 GrowableArray<ciInstanceKlass*>* exc_klasses,
2238 ciTypeFlow::StateVector* state) {
2239 int len = exceptions->length();
2240 assert(exc_klasses->length() == len, "must have same length");
2241 for (int i = 0; i < len; i++) {
2242 Block* block = exceptions->at(i);
2243 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2244
2245 if (!exception_klass->is_loaded()) {
2246 // Do not compile any code for unloaded exception types.
2247 // Following compiler passes are responsible for doing this also.
2248 continue;
2249 }
2250
2251 if (block->meet_exception(exception_klass, state)) {
2252 // Block was modified and has PO. Add it to the work list.
2253 if (block->has_post_order() &&
2254 !block->is_on_work_list()) {
2255 add_to_work_list(block);
2256 }
2257 }
2258 }
2259 }
2260
2261 // ------------------------------------------------------------------
2262 // ciTypeFlow::flow_successors
2263 //
2264 // Merge the current state into all successors at the current point
2265 // in the code.
2266 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2267 ciTypeFlow::StateVector* state) {
2268 int len = successors->length();
2269 for (int i = 0; i < len; i++) {
2270 Block* block = successors->at(i);
2271 if (block->meet(state)) {
2272 // Block was modified and has PO. Add it to the work list.
2273 if (block->has_post_order() &&
2274 !block->is_on_work_list()) {
2275 add_to_work_list(block);
2276 }
2277 }
2278 }
2279 }
2280
2281 // ------------------------------------------------------------------
2282 // ciTypeFlow::can_trap
2283 //
2284 // Tells if a given instruction is able to generate an exception edge.
2285 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2286 // Cf. GenerateOopMap::do_exception_edge.
2287 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2288
2289 switch (str.cur_bc()) {
2290 case Bytecodes::_ldc:
2291 case Bytecodes::_ldc_w:
2292 case Bytecodes::_ldc2_w:
2293 return str.is_in_error() || !str.get_constant().is_loaded();
2294
2295 case Bytecodes::_aload_0:
2296 // These bytecodes can trap for rewriting. We need to assume that
2297 // they do not throw exceptions to make the monitor analysis work.
2298 return false;
2299
2300 case Bytecodes::_ireturn:
2301 case Bytecodes::_lreturn:
2302 case Bytecodes::_freturn:
2303 case Bytecodes::_dreturn:
2304 case Bytecodes::_areturn:
2305 case Bytecodes::_return:
2306 // We can assume the monitor stack is empty in this analysis.
2307 return false;
2308
2309 case Bytecodes::_monitorexit:
2310 // We can assume monitors are matched in this analysis.
2311 return false;
2312
2313 default:
2314 return true;
2315 }
2316 }
2317
2318 // ------------------------------------------------------------------
2319 // ciTypeFlow::clone_loop_heads
2320 //
2321 // Clone the loop heads
2322 bool ciTypeFlow::clone_loop_heads(StateVector* temp_vector, JsrSet* temp_set) {
2323 bool rslt = false;
2324 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2325 Loop* lp = iter.current();
2326 Block* head = lp->head();
2327 if (lp == loop_tree_root() ||
2328 lp->is_irreducible() ||
2329 !head->is_clonable_exit(lp))
2330 continue;
2331
2332 // Avoid BoxLock merge.
2333 if (EliminateNestedLocks && head->has_monitorenter())
2334 continue;
2335
2336 // check not already cloned
2337 if (head->backedge_copy_count() != 0)
2338 continue;
2339
2340 // Don't clone head of OSR loop to get correct types in start block.
2341 if (is_osr_flow() && head->start() == start_bci())
2342 continue;
2343
2344 // check _no_ shared head below us
2345 Loop* ch;
2346 for (ch = lp->child(); ch != nullptr && ch->head() != head; ch = ch->sibling());
2347 if (ch != nullptr)
2348 continue;
2349
2350 // Clone head
2351 Block* new_head = head->looping_succ(lp);
2352 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2353 // Update lp's info
2354 clone->set_loop(lp);
2355 lp->set_head(new_head);
2356 lp->set_tail(clone);
2357 // And move original head into outer loop
2358 head->set_loop(lp->parent());
2359
2360 rslt = true;
2361 }
2362 return rslt;
2363 }
2364
2365 // ------------------------------------------------------------------
2366 // ciTypeFlow::clone_loop_head
2367 //
2368 // Clone lp's head and replace tail's successors with clone.
2369 //
2370 // |
2371 // v
2372 // head <-> body
2373 // |
2374 // v
2375 // exit
2376 //
2377 // new_head
2378 //
2379 // |
2380 // v
2381 // head ----------\
2382 // | |
2383 // | v
2384 // | clone <-> body
2385 // | |
2386 // | /--/
2387 // | |
2388 // v v
2389 // exit
2390 //
2391 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2392 Block* head = lp->head();
2393 Block* tail = lp->tail();
2394 if (CITraceTypeFlow) {
2395 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2396 tty->print(" for predecessor "); tail->print_value_on(tty);
2397 tty->cr();
2398 }
2399 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2400 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2401
2402 assert(!clone->has_pre_order(), "just created");
2403 clone->set_next_pre_order();
2404
2405 // Accumulate profiled count for all backedges that share this loop's head
2406 int total_count = lp->profiled_count();
2407 for (Loop* lp1 = lp->parent(); lp1 != nullptr; lp1 = lp1->parent()) {
2408 for (Loop* lp2 = lp1; lp2 != nullptr; lp2 = lp2->sibling()) {
2409 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2410 total_count += lp2->profiled_count();
2411 }
2412 }
2413 }
2414 // Have the most frequent ones branch to the clone instead
2415 int count = 0;
2416 int loops_with_shared_head = 0;
2417 Block* latest_tail = tail;
2418 bool done = false;
2419 for (Loop* lp1 = lp; lp1 != nullptr && !done; lp1 = lp1->parent()) {
2420 for (Loop* lp2 = lp1; lp2 != nullptr && !done; lp2 = lp2->sibling()) {
2421 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2422 count += lp2->profiled_count();
2423 if (lp2->tail()->post_order() < latest_tail->post_order()) {
2424 latest_tail = lp2->tail();
2425 }
2426 loops_with_shared_head++;
2427 for (SuccIter iter(lp2->tail()); !iter.done(); iter.next()) {
2428 if (iter.succ() == head) {
2429 iter.set_succ(clone);
2430 // Update predecessor information
2431 head->predecessors()->remove(lp2->tail());
2432 clone->predecessors()->append(lp2->tail());
2433 }
2434 }
2435 flow_block(lp2->tail(), temp_vector, temp_set);
2436 if (lp2->head() == lp2->tail()) {
2437 // For self-loops, clone->head becomes clone->clone
2438 flow_block(clone, temp_vector, temp_set);
2439 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2440 if (iter.succ() == lp2->head()) {
2441 iter.set_succ(clone);
2442 // Update predecessor information
2443 lp2->head()->predecessors()->remove(clone);
2444 clone->predecessors()->append(clone);
2445 break;
2446 }
2447 }
2448 }
2449 if (total_count == 0 || count > (total_count * .9)) {
2450 done = true;
2451 }
2452 }
2453 }
2454 }
2455 assert(loops_with_shared_head >= 1, "at least one new");
2456 clone->set_rpo_next(latest_tail->rpo_next());
2457 latest_tail->set_rpo_next(clone);
2458 flow_block(clone, temp_vector, temp_set);
2459
2460 return clone;
2461 }
2462
2463 // ------------------------------------------------------------------
2464 // ciTypeFlow::flow_block
2465 //
2466 // Interpret the effects of the bytecodes on the incoming state
2467 // vector of a basic block. Push the changed state to succeeding
2468 // basic blocks.
2469 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2470 ciTypeFlow::StateVector* state,
2471 ciTypeFlow::JsrSet* jsrs) {
2472 if (CITraceTypeFlow) {
2473 tty->print("\n>> ANALYZING BLOCK : ");
2474 tty->cr();
2475 block->print_on(tty);
2476 }
2477 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2478
2479 int start = block->start();
2480 int limit = block->limit();
2481 int control = block->control();
2482 if (control != ciBlock::fall_through_bci) {
2483 limit = control;
2484 }
2485
2486 // Grab the state from the current block.
2487 block->copy_state_into(state);
2488 state->def_locals()->clear();
2489
2490 GrowableArray<Block*>* exceptions = block->exceptions();
2491 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2492 bool has_exceptions = exceptions->length() > 0;
2493
2494 bool exceptions_used = false;
2495
2496 ciBytecodeStream str(method());
2497 str.reset_to_bci(start);
2498 Bytecodes::Code code;
2499 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2500 str.cur_bci() < limit) {
2501 // Check for exceptional control flow from this point.
2502 if (has_exceptions && can_trap(str)) {
2503 flow_exceptions(exceptions, exc_klasses, state);
2504 exceptions_used = true;
2505 }
2506 // Apply the effects of the current bytecode to our state.
2507 bool res = state->apply_one_bytecode(&str);
2508
2509 // Watch for bailouts.
2510 if (failing()) return;
2511
2512 if (str.cur_bc() == Bytecodes::_monitorenter) {
2513 block->set_has_monitorenter();
2514 }
2515
2516 if (res) {
2517
2518 // We have encountered a trap. Record it in this block.
2519 block->set_trap(state->trap_bci(), state->trap_index());
2520
2521 if (CITraceTypeFlow) {
2522 tty->print_cr(">> Found trap");
2523 block->print_on(tty);
2524 }
2525
2526 // Save set of locals defined in this block
2527 block->def_locals()->add(state->def_locals());
2528
2529 // Record (no) successors.
2530 block->successors(&str, state, jsrs);
2531
2532 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2533
2534 // Discontinue interpretation of this Block.
2535 return;
2536 }
2537 }
2538
2539 GrowableArray<Block*>* successors = nullptr;
2540 if (control != ciBlock::fall_through_bci) {
2541 // Check for exceptional control flow from this point.
2542 if (has_exceptions && can_trap(str)) {
2543 flow_exceptions(exceptions, exc_klasses, state);
2544 exceptions_used = true;
2545 }
2546
2547 // Fix the JsrSet to reflect effect of the bytecode.
2548 block->copy_jsrs_into(jsrs);
2549 jsrs->apply_control(this, &str, state);
2550
2551 // Find successor edges based on old state and new JsrSet.
2552 successors = block->successors(&str, state, jsrs);
2553
2554 // Apply the control changes to the state.
2555 state->apply_one_bytecode(&str);
2556 } else {
2557 // Fall through control
2558 successors = block->successors(&str, nullptr, nullptr);
2559 }
2560
2561 // Save set of locals defined in this block
2562 block->def_locals()->add(state->def_locals());
2563
2564 // Remove untaken exception paths
2565 if (!exceptions_used)
2566 exceptions->clear();
2567
2568 // Pass our state to successors.
2569 flow_successors(successors, state);
2570 }
2571
2572 // ------------------------------------------------------------------
2573 // ciTypeFlow::PreOrderLoops::next
2574 //
2575 // Advance to next loop tree using a preorder, left-to-right traversal.
2576 void ciTypeFlow::PreorderLoops::next() {
2577 assert(!done(), "must not be done.");
2578 if (_current->child() != nullptr) {
2579 _current = _current->child();
2580 } else if (_current->sibling() != nullptr) {
2581 _current = _current->sibling();
2582 } else {
2583 while (_current != _root && _current->sibling() == nullptr) {
2584 _current = _current->parent();
2585 }
2586 if (_current == _root) {
2587 _current = nullptr;
2588 assert(done(), "must be done.");
2589 } else {
2590 assert(_current->sibling() != nullptr, "must be more to do");
2591 _current = _current->sibling();
2592 }
2593 }
2594 }
2595
2596 // If the tail is a branch to the head, retrieve how many times that path was taken from profiling
2597 int ciTypeFlow::Loop::profiled_count() {
2598 if (_profiled_count >= 0) {
2599 return _profiled_count;
2600 }
2601 ciMethodData* methodData = outer()->method()->method_data();
2602 if (!methodData->is_mature()) {
2603 _profiled_count = 0;
2604 return 0;
2605 }
2606 ciTypeFlow::Block* tail = this->tail();
2607 if (tail->control() == -1 || tail->has_trap()) {
2608 _profiled_count = 0;
2609 return 0;
2610 }
2611
2612 ciProfileData* data = methodData->bci_to_data(tail->control());
2613
2614 if (data == nullptr || !data->is_JumpData()) {
2615 _profiled_count = 0;
2616 return 0;
2617 }
2618
2619 ciBytecodeStream iter(outer()->method());
2620 iter.reset_to_bci(tail->control());
2621
2622 bool is_an_if = false;
2623 bool wide = false;
2624 Bytecodes::Code bc = iter.next();
2625 switch (bc) {
2626 case Bytecodes::_ifeq:
2627 case Bytecodes::_ifne:
2628 case Bytecodes::_iflt:
2629 case Bytecodes::_ifge:
2630 case Bytecodes::_ifgt:
2631 case Bytecodes::_ifle:
2632 case Bytecodes::_if_icmpeq:
2633 case Bytecodes::_if_icmpne:
2634 case Bytecodes::_if_icmplt:
2635 case Bytecodes::_if_icmpge:
2636 case Bytecodes::_if_icmpgt:
2637 case Bytecodes::_if_icmple:
2638 case Bytecodes::_if_acmpeq:
2639 case Bytecodes::_if_acmpne:
2640 case Bytecodes::_ifnull:
2641 case Bytecodes::_ifnonnull:
2642 is_an_if = true;
2643 break;
2644 case Bytecodes::_goto_w:
2645 case Bytecodes::_jsr_w:
2646 wide = true;
2647 break;
2648 case Bytecodes::_goto:
2649 case Bytecodes::_jsr:
2650 break;
2651 default:
2652 fatal(" invalid bytecode: %s", Bytecodes::name(iter.cur_bc()));
2653 }
2654
2655 GrowableArray<ciTypeFlow::Block*>* succs = tail->successors();
2656
2657 if (!is_an_if) {
2658 assert(((wide ? iter.get_far_dest() : iter.get_dest()) == head()->start()) == (succs->at(ciTypeFlow::GOTO_TARGET) == head()), "branch should lead to loop head");
2659 if (succs->at(ciTypeFlow::GOTO_TARGET) == head()) {
2660 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2661 return _profiled_count;
2662 }
2663 } else {
2664 assert((iter.get_dest() == head()->start()) == (succs->at(ciTypeFlow::IF_TAKEN) == head()), "bytecode and CFG not consistent");
2665 assert((tail->limit() == head()->start()) == (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()), "bytecode and CFG not consistent");
2666 if (succs->at(ciTypeFlow::IF_TAKEN) == head()) {
2667 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2668 return _profiled_count;
2669 } else if (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()) {
2670 _profiled_count = outer()->method()->scale_count(data->as_BranchData()->not_taken());
2671 return _profiled_count;
2672 }
2673 }
2674
2675 _profiled_count = 0;
2676 return _profiled_count;
2677 }
2678
2679 bool ciTypeFlow::Loop::at_insertion_point(Loop* lp, Loop* current) {
2680 int lp_pre_order = lp->head()->pre_order();
2681 if (current->head()->pre_order() < lp_pre_order) {
2682 return true;
2683 } else if (current->head()->pre_order() > lp_pre_order) {
2684 return false;
2685 }
2686 // In the case of a shared head, make the most frequent head/tail (as reported by profiling) the inner loop
2687 if (current->head() == lp->head()) {
2688 int lp_count = lp->profiled_count();
2689 int current_count = current->profiled_count();
2690 if (current_count < lp_count) {
2691 return true;
2692 } else if (current_count > lp_count) {
2693 return false;
2694 }
2695 }
2696 if (current->tail()->pre_order() > lp->tail()->pre_order()) {
2697 return true;
2698 }
2699 return false;
2700 }
2701
2702 // ------------------------------------------------------------------
2703 // ciTypeFlow::Loop::sorted_merge
2704 //
2705 // Merge the branch lp into this branch, sorting on the loop head
2706 // pre_orders. Returns the leaf of the merged branch.
2707 // Child and sibling pointers will be setup later.
2708 // Sort is (looking from leaf towards the root)
2709 // descending on primary key: loop head's pre_order, and
2710 // ascending on secondary key: loop tail's pre_order.
2711 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2712 Loop* leaf = this;
2713 Loop* prev = nullptr;
2714 Loop* current = leaf;
2715 while (lp != nullptr) {
2716 int lp_pre_order = lp->head()->pre_order();
2717 // Find insertion point for "lp"
2718 while (current != nullptr) {
2719 if (current == lp) {
2720 return leaf; // Already in list
2721 }
2722 if (at_insertion_point(lp, current)) {
2723 break;
2724 }
2725 prev = current;
2726 current = current->parent();
2727 }
2728 Loop* next_lp = lp->parent(); // Save future list of items to insert
2729 // Insert lp before current
2730 lp->set_parent(current);
2731 if (prev != nullptr) {
2732 prev->set_parent(lp);
2733 } else {
2734 leaf = lp;
2735 }
2736 prev = lp; // Inserted item is new prev[ious]
2737 lp = next_lp; // Next item to insert
2738 }
2739 return leaf;
2740 }
2741
2742 // ------------------------------------------------------------------
2743 // ciTypeFlow::build_loop_tree
2744 //
2745 // Incrementally build loop tree.
2746 void ciTypeFlow::build_loop_tree(Block* blk) {
2747 assert(!blk->is_post_visited(), "precondition");
2748 Loop* innermost = nullptr; // merge of loop tree branches over all successors
2749
2750 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2751 Loop* lp = nullptr;
2752 Block* succ = iter.succ();
2753 if (!succ->is_post_visited()) {
2754 // Found backedge since predecessor post visited, but successor is not
2755 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2756
2757 // Create a LoopNode to mark this loop.
2758 lp = new (arena()) Loop(succ, blk);
2759 if (succ->loop() == nullptr)
2760 succ->set_loop(lp);
2761 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2762
2763 } else { // Nested loop
2764 lp = succ->loop();
2765
2766 // If succ is loop head, find outer loop.
2767 while (lp != nullptr && lp->head() == succ) {
2768 lp = lp->parent();
2769 }
2770 if (lp == nullptr) {
2771 // Infinite loop, it's parent is the root
2772 lp = loop_tree_root();
2773 }
2774 }
2775
2776 // Check for irreducible loop.
2777 // Successor has already been visited. If the successor's loop head
2778 // has already been post-visited, then this is another entry into the loop.
2779 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2780 _has_irreducible_entry = true;
2781 lp->set_irreducible(succ);
2782 if (!succ->is_on_work_list()) {
2783 // Assume irreducible entries need more data flow
2784 add_to_work_list(succ);
2785 }
2786 Loop* plp = lp->parent();
2787 if (plp == nullptr) {
2788 // This only happens for some irreducible cases. The parent
2789 // will be updated during a later pass.
2790 break;
2791 }
2792 lp = plp;
2793 }
2794
2795 // Merge loop tree branch for all successors.
2796 innermost = innermost == nullptr ? lp : innermost->sorted_merge(lp);
2797
2798 } // end loop
2799
2800 if (innermost == nullptr) {
2801 assert(blk->successors()->length() == 0, "CFG exit");
2802 blk->set_loop(loop_tree_root());
2803 } else if (innermost->head() == blk) {
2804 // If loop header, complete the tree pointers
2805 if (blk->loop() != innermost) {
2806 #ifdef ASSERT
2807 assert(blk->loop()->head() == innermost->head(), "same head");
2808 Loop* dl;
2809 for (dl = innermost; dl != nullptr && dl != blk->loop(); dl = dl->parent());
2810 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2811 #endif
2812 blk->set_loop(innermost);
2813 }
2814 innermost->def_locals()->add(blk->def_locals());
2815 Loop* l = innermost;
2816 Loop* p = l->parent();
2817 while (p && l->head() == blk) {
2818 l->set_sibling(p->child()); // Put self on parents 'next child'
2819 p->set_child(l); // Make self the first child of parent
2820 p->def_locals()->add(l->def_locals());
2821 l = p; // Walk up the parent chain
2822 p = l->parent();
2823 }
2824 } else {
2825 blk->set_loop(innermost);
2826 innermost->def_locals()->add(blk->def_locals());
2827 }
2828 }
2829
2830 // ------------------------------------------------------------------
2831 // ciTypeFlow::Loop::contains
2832 //
2833 // Returns true if lp is nested loop.
2834 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2835 assert(lp != nullptr, "");
2836 if (this == lp || head() == lp->head()) return true;
2837 int depth1 = depth();
2838 int depth2 = lp->depth();
2839 if (depth1 > depth2)
2840 return false;
2841 while (depth1 < depth2) {
2842 depth2--;
2843 lp = lp->parent();
2844 }
2845 return this == lp;
2846 }
2847
2848 // ------------------------------------------------------------------
2849 // ciTypeFlow::Loop::depth
2850 //
2851 // Loop depth
2852 int ciTypeFlow::Loop::depth() const {
2853 int dp = 0;
2854 for (Loop* lp = this->parent(); lp != nullptr; lp = lp->parent())
2855 dp++;
2856 return dp;
2857 }
2858
2859 #ifndef PRODUCT
2860 // ------------------------------------------------------------------
2861 // ciTypeFlow::Loop::print
2862 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2863 for (int i = 0; i < indent; i++) st->print(" ");
2864 st->print("%d<-%d %s",
2865 is_root() ? 0 : this->head()->pre_order(),
2866 is_root() ? 0 : this->tail()->pre_order(),
2867 is_irreducible()?" irr":"");
2868 st->print(" defs: ");
2869 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2870 st->cr();
2871 for (Loop* ch = child(); ch != nullptr; ch = ch->sibling())
2872 ch->print(st, indent+2);
2873 }
2874 #endif
2875
2876 // ------------------------------------------------------------------
2877 // ciTypeFlow::df_flow_types
2878 //
2879 // Perform the depth first type flow analysis. Helper for flow_types.
2880 void ciTypeFlow::df_flow_types(Block* start,
2881 bool do_flow,
2882 StateVector* temp_vector,
2883 JsrSet* temp_set) {
2884 int dft_len = 100;
2885 GrowableArray<Block*> stk(dft_len);
2886
2887 ciBlock* dummy = _method->get_method_blocks()->make_dummy_block();
2888 JsrSet* root_set = new JsrSet(0);
2889 Block* root_head = new (arena()) Block(this, dummy, root_set);
2890 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2891 root_head->set_pre_order(0);
2892 root_head->set_post_order(0);
2893 root_tail->set_pre_order(max_jint);
2894 root_tail->set_post_order(max_jint);
2895 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2896
2897 stk.push(start);
2898
2899 _next_pre_order = 0; // initialize pre_order counter
2900 _rpo_list = nullptr;
2901 int next_po = 0; // initialize post_order counter
2902
2903 // Compute RPO and the control flow graph
2904 int size;
2905 while ((size = stk.length()) > 0) {
2906 Block* blk = stk.top(); // Leave node on stack
2907 if (!blk->is_visited()) {
2908 // forward arc in graph
2909 assert (!blk->has_pre_order(), "");
2910 blk->set_next_pre_order();
2911
2912 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2913 // Too many basic blocks. Bail out.
2914 // This can happen when try/finally constructs are nested to depth N,
2915 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2916 // "MaxNodeLimit / 2" is used because probably the parser will
2917 // generate at least twice that many nodes and bail out.
2918 record_failure("too many basic blocks");
2919 return;
2920 }
2921 if (do_flow) {
2922 flow_block(blk, temp_vector, temp_set);
2923 if (failing()) return; // Watch for bailouts.
2924 }
2925 } else if (!blk->is_post_visited()) {
2926 // cross or back arc
2927 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2928 Block* succ = iter.succ();
2929 if (!succ->is_visited()) {
2930 stk.push(succ);
2931 }
2932 }
2933 if (stk.length() == size) {
2934 // There were no additional children, post visit node now
2935 stk.pop(); // Remove node from stack
2936
2937 build_loop_tree(blk);
2938 blk->set_post_order(next_po++); // Assign post order
2939 prepend_to_rpo_list(blk);
2940 assert(blk->is_post_visited(), "");
2941
2942 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2943 // Assume loop heads need more data flow
2944 add_to_work_list(blk);
2945 }
2946 }
2947 } else {
2948 stk.pop(); // Remove post-visited node from stack
2949 }
2950 }
2951 }
2952
2953 // ------------------------------------------------------------------
2954 // ciTypeFlow::flow_types
2955 //
2956 // Perform the type flow analysis, creating and cloning Blocks as
2957 // necessary.
2958 void ciTypeFlow::flow_types() {
2959 ResourceMark rm;
2960 StateVector* temp_vector = new StateVector(this);
2961 JsrSet* temp_set = new JsrSet(4);
2962
2963 // Create the method entry block.
2964 Block* start = block_at(start_bci(), temp_set);
2965
2966 // Load the initial state into it.
2967 const StateVector* start_state = get_start_state();
2968 if (failing()) return;
2969 start->meet(start_state);
2970
2971 // Depth first visit
2972 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2973
2974 if (failing()) return;
2975 assert(_rpo_list == start, "must be start");
2976
2977 // Any loops found?
2978 if (loop_tree_root()->child() != nullptr &&
2979 env()->comp_level() >= CompLevel_full_optimization) {
2980 // Loop optimizations are not performed on Tier1 compiles.
2981
2982 bool changed = clone_loop_heads(temp_vector, temp_set);
2983
2984 // If some loop heads were cloned, recompute postorder and loop tree
2985 if (changed) {
2986 loop_tree_root()->set_child(nullptr);
2987 for (Block* blk = _rpo_list; blk != nullptr;) {
2988 Block* next = blk->rpo_next();
2989 blk->df_init();
2990 blk = next;
2991 }
2992 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2993 }
2994 }
2995
2996 if (CITraceTypeFlow) {
2997 tty->print_cr("\nLoop tree");
2998 loop_tree_root()->print();
2999 }
3000
3001 // Continue flow analysis until fixed point reached
3002
3003 DEBUG_ONLY(int max_block = _next_pre_order;)
3004
3005 while (!work_list_empty()) {
3006 Block* blk = work_list_next();
3007 assert (blk->has_post_order(), "post order assigned above");
3008
3009 flow_block(blk, temp_vector, temp_set);
3010
3011 assert (max_block == _next_pre_order, "no new blocks");
3012 assert (!failing(), "no more bailouts");
3013 }
3014 }
3015
3016 // ------------------------------------------------------------------
3017 // ciTypeFlow::map_blocks
3018 //
3019 // Create the block map, which indexes blocks in reverse post-order.
3020 void ciTypeFlow::map_blocks() {
3021 assert(_block_map == nullptr, "single initialization");
3022 int block_ct = _next_pre_order;
3023 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
3024 assert(block_ct == block_count(), "");
3025
3026 Block* blk = _rpo_list;
3027 for (int m = 0; m < block_ct; m++) {
3028 int rpo = blk->rpo();
3029 assert(rpo == m, "should be sequential");
3030 _block_map[rpo] = blk;
3031 blk = blk->rpo_next();
3032 }
3033 assert(blk == nullptr, "should be done");
3034
3035 for (int j = 0; j < block_ct; j++) {
3036 assert(_block_map[j] != nullptr, "must not drop any blocks");
3037 Block* block = _block_map[j];
3038 // Remove dead blocks from successor lists:
3039 for (int e = 0; e <= 1; e++) {
3040 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
3041 for (int k = 0; k < l->length(); k++) {
3042 Block* s = l->at(k);
3043 if (!s->has_post_order()) {
3044 if (CITraceTypeFlow) {
3045 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
3046 s->print_value_on(tty);
3047 tty->cr();
3048 }
3049 l->remove(s);
3050 --k;
3051 }
3052 }
3053 }
3054 }
3055 }
3056
3057 // ------------------------------------------------------------------
3058 // ciTypeFlow::get_block_for
3059 //
3060 // Find a block with this ciBlock which has a compatible JsrSet.
3061 // If no such block exists, create it, unless the option is no_create.
3062 // If the option is create_backedge_copy, always create a fresh backedge copy.
3063 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
3064 Arena* a = arena();
3065 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3066 if (blocks == nullptr) {
3067 // Query only?
3068 if (option == no_create) return nullptr;
3069
3070 // Allocate the growable array.
3071 blocks = new (a) GrowableArray<Block*>(a, 4, 0, nullptr);
3072 _idx_to_blocklist[ciBlockIndex] = blocks;
3073 }
3074
3075 if (option != create_backedge_copy) {
3076 int len = blocks->length();
3077 for (int i = 0; i < len; i++) {
3078 Block* block = blocks->at(i);
3079 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3080 return block;
3081 }
3082 }
3083 }
3084
3085 // Query only?
3086 if (option == no_create) return nullptr;
3087
3088 // We did not find a compatible block. Create one.
3089 Block* new_block = new (a) Block(this, _method->get_method_blocks()->block(ciBlockIndex), jsrs);
3090 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
3091 blocks->append(new_block);
3092 return new_block;
3093 }
3094
3095 // ------------------------------------------------------------------
3096 // ciTypeFlow::backedge_copy_count
3097 //
3098 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
3099 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3100
3101 if (blocks == nullptr) {
3102 return 0;
3103 }
3104
3105 int count = 0;
3106 int len = blocks->length();
3107 for (int i = 0; i < len; i++) {
3108 Block* block = blocks->at(i);
3109 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3110 count++;
3111 }
3112 }
3113
3114 return count;
3115 }
3116
3117 // ------------------------------------------------------------------
3118 // ciTypeFlow::do_flow
3119 //
3120 // Perform type inference flow analysis.
3121 void ciTypeFlow::do_flow() {
3122 if (CITraceTypeFlow) {
3123 tty->print_cr("\nPerforming flow analysis on method");
3124 method()->print();
3125 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
3126 tty->cr();
3127 method()->print_codes();
3128 }
3129 if (CITraceTypeFlow) {
3130 tty->print_cr("Initial CI Blocks");
3131 print_on(tty);
3132 }
3133 flow_types();
3134 // Watch for bailouts.
3135 if (failing()) {
3136 return;
3137 }
3138
3139 map_blocks();
3140
3141 if (CIPrintTypeFlow || CITraceTypeFlow) {
3142 rpo_print_on(tty);
3143 }
3144 }
3145
3146 // ------------------------------------------------------------------
3147 // ciTypeFlow::is_dominated_by
3148 //
3149 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3150 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3151 assert(!method()->has_jsrs(), "jsrs are not supported");
3152
3153 ResourceMark rm;
3154 JsrSet* jsrs = new ciTypeFlow::JsrSet();
3155 int index = _method->get_method_blocks()->block_containing(bci)->index();
3156 int dom_index = _method->get_method_blocks()->block_containing(dom_bci)->index();
3157 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3158 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3159
3160 // Start block dominates all other blocks
3161 if (start_block()->rpo() == dom_block->rpo()) {
3162 return true;
3163 }
3164
3165 // Dominated[i] is true if block i is dominated by dom_block
3166 int num_blocks = block_count();
3167 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3168 for (int i = 0; i < num_blocks; ++i) {
3169 dominated[i] = true;
3170 }
3171 dominated[start_block()->rpo()] = false;
3172
3173 // Iterative dominator algorithm
3174 bool changed = true;
3175 while (changed) {
3176 changed = false;
3177 // Use reverse postorder iteration
3178 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3179 if (blk->is_start()) {
3180 // Ignore start block
3181 continue;
3182 }
3183 // The block is dominated if it is the dominating block
3184 // itself or if all predecessors are dominated.
3185 int index = blk->rpo();
3186 bool dom = (index == dom_block->rpo());
3187 if (!dom) {
3188 // Check if all predecessors are dominated
3189 dom = true;
3190 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3191 Block* pred = blk->predecessors()->at(i);
3192 if (!dominated[pred->rpo()]) {
3193 dom = false;
3194 break;
3195 }
3196 }
3197 }
3198 // Update dominator information
3199 if (dominated[index] != dom) {
3200 changed = true;
3201 dominated[index] = dom;
3202 }
3203 }
3204 }
3205 // block dominated by dom_block?
3206 return dominated[block->rpo()];
3207 }
3208
3209 // ------------------------------------------------------------------
3210 // ciTypeFlow::record_failure()
3211 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3212 // This is required because there is not a 1-1 relation between the ciEnv and
3213 // the TypeFlow passes within a compilation task. For example, if the compiler
3214 // is considering inlining a method, it will request a TypeFlow. If that fails,
3215 // the compilation as a whole may continue without the inlining. Some TypeFlow
3216 // requests are not optional; if they fail the requestor is responsible for
3217 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3218 void ciTypeFlow::record_failure(const char* reason) {
3219 if (env()->log() != nullptr) {
3220 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3221 }
3222 if (_failure_reason == nullptr) {
3223 // Record the first failure reason.
3224 _failure_reason = reason;
3225 }
3226 }
3227
3228 ciType* ciTypeFlow::mark_as_early_larval(ciType* type) {
3229 // Wrap the type to carry the information that it is null-free
3230 return env()->make_early_larval_wrapper(type);
3231 }
3232
3233
3234 ciType* ciTypeFlow::mark_as_null_free(ciType* type) {
3235 // Wrap the type to carry the information that it is null-free
3236 return env()->make_null_free_wrapper(type);
3237 }
3238
3239 #ifndef PRODUCT
3240 void ciTypeFlow::print() const { print_on(tty); }
3241
3242 // ------------------------------------------------------------------
3243 // ciTypeFlow::print_on
3244 void ciTypeFlow::print_on(outputStream* st) const {
3245 // Walk through CI blocks
3246 st->print_cr("********************************************************");
3247 st->print ("TypeFlow for ");
3248 method()->name()->print_symbol_on(st);
3249 int limit_bci = code_size();
3250 st->print_cr(" %d bytes", limit_bci);
3251 ciMethodBlocks* mblks = _method->get_method_blocks();
3252 ciBlock* current = nullptr;
3253 for (int bci = 0; bci < limit_bci; bci++) {
3254 ciBlock* blk = mblks->block_containing(bci);
3255 if (blk != nullptr && blk != current) {
3256 current = blk;
3257 current->print_on(st);
3258
3259 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3260 int num_blocks = (blocks == nullptr) ? 0 : blocks->length();
3261
3262 if (num_blocks == 0) {
3263 st->print_cr(" No Blocks");
3264 } else {
3265 for (int i = 0; i < num_blocks; i++) {
3266 Block* block = blocks->at(i);
3267 block->print_on(st);
3268 }
3269 }
3270 st->print_cr("--------------------------------------------------------");
3271 st->cr();
3272 }
3273 }
3274 st->print_cr("********************************************************");
3275 st->cr();
3276 }
3277
3278 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3279 st->print_cr("********************************************************");
3280 st->print ("TypeFlow for ");
3281 method()->name()->print_symbol_on(st);
3282 int limit_bci = code_size();
3283 st->print_cr(" %d bytes", limit_bci);
3284 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3285 blk->print_on(st);
3286 st->print_cr("--------------------------------------------------------");
3287 st->cr();
3288 }
3289 st->print_cr("********************************************************");
3290 st->cr();
3291 }
3292 #endif