1 /*
2 * Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciMethod.hpp"
29 #include "ci/ciMethodData.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "ci/ciTypeArrayKlass.hpp"
33 #include "ci/ciTypeFlow.hpp"
34 #include "compiler/compileLog.hpp"
35 #include "interpreter/bytecode.hpp"
36 #include "interpreter/bytecodes.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "opto/compile.hpp"
41 #include "opto/node.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "utilities/growableArray.hpp"
44
45 // ciTypeFlow::JsrSet
46 //
47 // A JsrSet represents some set of JsrRecords. This class
48 // is used to record a set of all jsr routines which we permit
49 // execution to return (ret) from.
50 //
51 // During abstract interpretation, JsrSets are used to determine
52 // whether two paths which reach a given block are unique, and
53 // should be cloned apart, or are compatible, and should merge
54 // together.
55
56 // ------------------------------------------------------------------
57 // ciTypeFlow::JsrSet::JsrSet
58
59 // Allocate growable array storage in Arena.
60 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) : _set(arena, default_len, 0, nullptr) {
61 assert(arena != nullptr, "invariant");
62 }
63
64 // Allocate growable array storage in current ResourceArea.
65 ciTypeFlow::JsrSet::JsrSet(int default_len) : _set(default_len, 0, nullptr) {}
66
67 // ------------------------------------------------------------------
68 // ciTypeFlow::JsrSet::copy_into
69 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
70 int len = size();
71 jsrs->_set.clear();
72 for (int i = 0; i < len; i++) {
73 jsrs->_set.append(_set.at(i));
74 }
75 }
76
77 // ------------------------------------------------------------------
78 // ciTypeFlow::JsrSet::is_compatible_with
79 //
80 // !!!! MISGIVINGS ABOUT THIS... disregard
81 //
82 // Is this JsrSet compatible with some other JsrSet?
83 //
84 // In set-theoretic terms, a JsrSet can be viewed as a partial function
85 // from entry addresses to return addresses. Two JsrSets A and B are
86 // compatible iff
87 //
88 // For any x,
89 // A(x) defined and B(x) defined implies A(x) == B(x)
90 //
91 // Less formally, two JsrSets are compatible when they have identical
92 // return addresses for any entry addresses they share in common.
93 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
94 // Walk through both sets in parallel. If the same entry address
95 // appears in both sets, then the return address must match for
96 // the sets to be compatible.
97 int size1 = size();
98 int size2 = other->size();
99
100 // Special case. If nothing is on the jsr stack, then there can
101 // be no ret.
102 if (size2 == 0) {
103 return true;
104 } else if (size1 != size2) {
105 return false;
106 } else {
107 for (int i = 0; i < size1; i++) {
108 JsrRecord* record1 = record_at(i);
109 JsrRecord* record2 = other->record_at(i);
110 if (record1->entry_address() != record2->entry_address() ||
111 record1->return_address() != record2->return_address()) {
112 return false;
113 }
114 }
115 return true;
116 }
117
118 #if 0
119 int pos1 = 0;
120 int pos2 = 0;
121 int size1 = size();
122 int size2 = other->size();
123 while (pos1 < size1 && pos2 < size2) {
124 JsrRecord* record1 = record_at(pos1);
125 JsrRecord* record2 = other->record_at(pos2);
126 int entry1 = record1->entry_address();
127 int entry2 = record2->entry_address();
128 if (entry1 < entry2) {
129 pos1++;
130 } else if (entry1 > entry2) {
131 pos2++;
132 } else {
133 if (record1->return_address() == record2->return_address()) {
134 pos1++;
135 pos2++;
136 } else {
137 // These two JsrSets are incompatible.
138 return false;
139 }
140 }
141 }
142 // The two JsrSets agree.
143 return true;
144 #endif
145 }
146
147 // ------------------------------------------------------------------
148 // ciTypeFlow::JsrSet::insert_jsr_record
149 //
150 // Insert the given JsrRecord into the JsrSet, maintaining the order
151 // of the set and replacing any element with the same entry address.
152 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
153 int len = size();
154 int entry = record->entry_address();
155 int pos = 0;
156 for ( ; pos < len; pos++) {
157 JsrRecord* current = record_at(pos);
158 if (entry == current->entry_address()) {
159 // Stomp over this entry.
160 _set.at_put(pos, record);
161 assert(size() == len, "must be same size");
162 return;
163 } else if (entry < current->entry_address()) {
164 break;
165 }
166 }
167
168 // Insert the record into the list.
169 JsrRecord* swap = record;
170 JsrRecord* temp = nullptr;
171 for ( ; pos < len; pos++) {
172 temp = _set.at(pos);
173 _set.at_put(pos, swap);
174 swap = temp;
175 }
176 _set.append(swap);
177 assert(size() == len+1, "must be larger");
178 }
179
180 // ------------------------------------------------------------------
181 // ciTypeFlow::JsrSet::remove_jsr_record
182 //
183 // Remove the JsrRecord with the given return address from the JsrSet.
184 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
185 int len = size();
186 for (int i = 0; i < len; i++) {
187 if (record_at(i)->return_address() == return_address) {
188 // We have found the proper entry. Remove it from the
189 // JsrSet and exit.
190 for (int j = i + 1; j < len ; j++) {
191 _set.at_put(j - 1, _set.at(j));
192 }
193 _set.trunc_to(len - 1);
194 assert(size() == len-1, "must be smaller");
195 return;
196 }
197 }
198 assert(false, "verify: returning from invalid subroutine");
199 }
200
201 // ------------------------------------------------------------------
202 // ciTypeFlow::JsrSet::apply_control
203 //
204 // Apply the effect of a control-flow bytecode on the JsrSet. The
205 // only bytecodes that modify the JsrSet are jsr and ret.
206 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
207 ciBytecodeStream* str,
208 ciTypeFlow::StateVector* state) {
209 Bytecodes::Code code = str->cur_bc();
210 if (code == Bytecodes::_jsr) {
211 JsrRecord* record =
212 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
213 insert_jsr_record(record);
214 } else if (code == Bytecodes::_jsr_w) {
215 JsrRecord* record =
216 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
217 insert_jsr_record(record);
218 } else if (code == Bytecodes::_ret) {
219 Cell local = state->local(str->get_index());
220 ciType* return_address = state->type_at(local);
221 assert(return_address->is_return_address(), "verify: wrong type");
222 if (size() == 0) {
223 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
224 // This can happen when a loop is inside a finally clause (4614060).
225 analyzer->record_failure("OSR in finally clause");
226 return;
227 }
228 remove_jsr_record(return_address->as_return_address()->bci());
229 }
230 }
231
232 #ifndef PRODUCT
233 // ------------------------------------------------------------------
234 // ciTypeFlow::JsrSet::print_on
235 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
236 st->print("{ ");
237 int num_elements = size();
238 if (num_elements > 0) {
239 int i = 0;
240 for( ; i < num_elements - 1; i++) {
241 _set.at(i)->print_on(st);
242 st->print(", ");
243 }
244 _set.at(i)->print_on(st);
245 st->print(" ");
246 }
247 st->print("}");
248 }
249 #endif
250
251 // ciTypeFlow::StateVector
252 //
253 // A StateVector summarizes the type information at some point in
254 // the program.
255
256 // ------------------------------------------------------------------
257 // ciTypeFlow::StateVector::type_meet
258 //
259 // Meet two types.
260 //
261 // The semi-lattice of types use by this analysis are modeled on those
262 // of the verifier. The lattice is as follows:
263 //
264 // top_type() >= all non-extremal types >= bottom_type
265 // and
266 // Every primitive type is comparable only with itself. The meet of
267 // reference types is determined by their kind: instance class,
268 // interface, or array class. The meet of two types of the same
269 // kind is their least common ancestor. The meet of two types of
270 // different kinds is always java.lang.Object.
271 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
272 assert(t1 != t2, "checked in caller");
273 if (t1->equals(top_type())) {
274 return t2;
275 } else if (t2->equals(top_type())) {
276 return t1;
277 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
278 // Special case null_type. null_type meet any reference type T
279 // is T. null_type meet null_type is null_type.
280 if (t1->equals(null_type())) {
281 if (!t2->is_primitive_type() || t2->equals(null_type())) {
282 return t2;
283 }
284 } else if (t2->equals(null_type())) {
285 if (!t1->is_primitive_type()) {
286 return t1;
287 }
288 }
289
290 // At least one of the two types is a non-top primitive type.
291 // The other type is not equal to it. Fall to bottom.
292 return bottom_type();
293 } else {
294 // Both types are non-top non-primitive types. That is,
295 // both types are either instanceKlasses or arrayKlasses.
296 ciKlass* object_klass = analyzer->env()->Object_klass();
297 ciKlass* k1 = t1->as_klass();
298 ciKlass* k2 = t2->as_klass();
299 if (k1->equals(object_klass) || k2->equals(object_klass)) {
300 return object_klass;
301 } else if (!k1->is_loaded() || !k2->is_loaded()) {
302 // Unloaded classes fall to java.lang.Object at a merge.
303 return object_klass;
304 } else if (k1->is_interface() != k2->is_interface()) {
305 // When an interface meets a non-interface, we get Object;
306 // This is what the verifier does.
307 return object_klass;
308 } else if (k1->is_array_klass() || k2->is_array_klass()) {
309 // When an array meets a non-array, we get Object.
310 // When objArray meets typeArray, we also get Object.
311 // And when typeArray meets different typeArray, we again get Object.
312 // But when objArray meets objArray, we look carefully at element types.
313 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
314 // Meet the element types, then construct the corresponding array type.
315 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
316 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
317 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
318 // Do an easy shortcut if one type is a super of the other.
319 if (elem == elem1) {
320 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
321 return k1;
322 } else if (elem == elem2) {
323 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
324 return k2;
325 } else {
326 return ciObjArrayKlass::make(elem);
327 }
328 } else {
329 return object_klass;
330 }
331 } else {
332 // Must be two plain old instance klasses.
333 assert(k1->is_instance_klass(), "previous cases handle non-instances");
334 assert(k2->is_instance_klass(), "previous cases handle non-instances");
335 return k1->least_common_ancestor(k2);
336 }
337 }
338 }
339
340
341 // ------------------------------------------------------------------
342 // ciTypeFlow::StateVector::StateVector
343 //
344 // Build a new state vector
345 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
346 _outer = analyzer;
347 _stack_size = -1;
348 _monitor_count = -1;
349 // Allocate the _types array
350 int max_cells = analyzer->max_cells();
351 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
352 for (int i=0; i<max_cells; i++) {
353 _types[i] = top_type();
354 }
355 _trap_bci = -1;
356 _trap_index = 0;
357 _def_locals.clear();
358 }
359
360
361 // ------------------------------------------------------------------
362 // ciTypeFlow::get_start_state
363 //
364 // Set this vector to the method entry state.
365 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
366 StateVector* state = new StateVector(this);
367 if (is_osr_flow()) {
368 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
369 if (non_osr_flow->failing()) {
370 record_failure(non_osr_flow->failure_reason());
371 return nullptr;
372 }
373 JsrSet* jsrs = new JsrSet(4);
374 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
375 if (non_osr_block == nullptr) {
376 record_failure("cannot reach OSR point");
377 return nullptr;
378 }
379 // load up the non-OSR state at this point
380 non_osr_block->copy_state_into(state);
381 int non_osr_start = non_osr_block->start();
382 if (non_osr_start != start_bci()) {
383 // must flow forward from it
384 if (CITraceTypeFlow) {
385 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
386 }
387 Block* block = block_at(non_osr_start, jsrs);
388 assert(block->limit() == start_bci(), "must flow forward to start");
389 flow_block(block, state, jsrs);
390 }
391 return state;
392 // Note: The code below would be an incorrect for an OSR flow,
393 // even if it were possible for an OSR entry point to be at bci zero.
394 }
395 // "Push" the method signature into the first few locals.
396 state->set_stack_size(-max_locals());
397 if (!method()->is_static()) {
398 state->push(method()->holder());
399 assert(state->tos() == state->local(0), "");
400 }
401 for (ciSignatureStream str(method()->signature());
402 !str.at_return_type();
403 str.next()) {
404 state->push_translate(str.type());
405 }
406 // Set the rest of the locals to bottom.
407 assert(state->stack_size() <= 0, "stack size should not be strictly positive");
408 while (state->stack_size() < 0) {
409 state->push(state->bottom_type());
410 }
411 // Lock an object, if necessary.
412 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
413 return state;
414 }
415
416 // ------------------------------------------------------------------
417 // ciTypeFlow::StateVector::copy_into
418 //
419 // Copy our value into some other StateVector
420 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
421 const {
422 copy->set_stack_size(stack_size());
423 copy->set_monitor_count(monitor_count());
424 Cell limit = limit_cell();
425 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
426 copy->set_type_at(c, type_at(c));
427 }
428 }
429
430 // ------------------------------------------------------------------
431 // ciTypeFlow::StateVector::meet
432 //
433 // Meets this StateVector with another, destructively modifying this
434 // one. Returns true if any modification takes place.
435 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
436 if (monitor_count() == -1) {
437 set_monitor_count(incoming->monitor_count());
438 }
439 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
440
441 if (stack_size() == -1) {
442 set_stack_size(incoming->stack_size());
443 Cell limit = limit_cell();
444 #ifdef ASSERT
445 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
446 assert(type_at(c) == top_type(), "");
447 } }
448 #endif
449 // Make a simple copy of the incoming state.
450 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
451 set_type_at(c, incoming->type_at(c));
452 }
453 return true; // it is always different the first time
454 }
455 #ifdef ASSERT
456 if (stack_size() != incoming->stack_size()) {
457 _outer->method()->print_codes();
458 tty->print_cr("!!!! Stack size conflict");
459 tty->print_cr("Current state:");
460 print_on(tty);
461 tty->print_cr("Incoming state:");
462 ((StateVector*)incoming)->print_on(tty);
463 }
464 #endif
465 assert(stack_size() == incoming->stack_size(), "sanity");
466
467 bool different = false;
468 Cell limit = limit_cell();
469 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
470 ciType* t1 = type_at(c);
471 ciType* t2 = incoming->type_at(c);
472 if (!t1->equals(t2)) {
473 ciType* new_type = type_meet(t1, t2);
474 if (!t1->equals(new_type)) {
475 set_type_at(c, new_type);
476 different = true;
477 }
478 }
479 }
480 return different;
481 }
482
483 // ------------------------------------------------------------------
484 // ciTypeFlow::StateVector::meet_exception
485 //
486 // Meets this StateVector with another, destructively modifying this
487 // one. The incoming state is coming via an exception. Returns true
488 // if any modification takes place.
489 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
490 const ciTypeFlow::StateVector* incoming) {
491 if (monitor_count() == -1) {
492 set_monitor_count(incoming->monitor_count());
493 }
494 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
495
496 if (stack_size() == -1) {
497 set_stack_size(1);
498 }
499
500 assert(stack_size() == 1, "must have one-element stack");
501
502 bool different = false;
503
504 // Meet locals from incoming array.
505 Cell limit = local(_outer->max_locals()-1);
506 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
507 ciType* t1 = type_at(c);
508 ciType* t2 = incoming->type_at(c);
509 if (!t1->equals(t2)) {
510 ciType* new_type = type_meet(t1, t2);
511 if (!t1->equals(new_type)) {
512 set_type_at(c, new_type);
513 different = true;
514 }
515 }
516 }
517
518 // Handle stack separately. When an exception occurs, the
519 // only stack entry is the exception instance.
520 ciType* tos_type = type_at_tos();
521 if (!tos_type->equals(exc)) {
522 ciType* new_type = type_meet(tos_type, exc);
523 if (!tos_type->equals(new_type)) {
524 set_type_at_tos(new_type);
525 different = true;
526 }
527 }
528
529 return different;
530 }
531
532 // ------------------------------------------------------------------
533 // ciTypeFlow::StateVector::push_translate
534 void ciTypeFlow::StateVector::push_translate(ciType* type) {
535 BasicType basic_type = type->basic_type();
536 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
537 basic_type == T_BYTE || basic_type == T_SHORT) {
538 push_int();
539 } else {
540 push(type);
541 if (type->is_two_word()) {
542 push(half_type(type));
543 }
544 }
545 }
546
547 // ------------------------------------------------------------------
548 // ciTypeFlow::StateVector::do_aaload
549 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
550 pop_int();
551 ciObjArrayKlass* array_klass = pop_objArray();
552 if (array_klass == nullptr) {
553 // Did aaload on a null reference; push a null and ignore the exception.
554 // This instruction will never continue normally. All we have to do
555 // is report a value that will meet correctly with any downstream
556 // reference types on paths that will truly be executed. This null type
557 // meets with any reference type to yield that same reference type.
558 // (The compiler will generate an unconditional exception here.)
559 push(null_type());
560 return;
561 }
562 if (!array_klass->is_loaded()) {
563 // Only fails for some -Xcomp runs
564 trap(str, array_klass,
565 Deoptimization::make_trap_request
566 (Deoptimization::Reason_unloaded,
567 Deoptimization::Action_reinterpret));
568 return;
569 }
570 ciKlass* element_klass = array_klass->element_klass();
571 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
572 Untested("unloaded array element class in ciTypeFlow");
573 trap(str, element_klass,
574 Deoptimization::make_trap_request
575 (Deoptimization::Reason_unloaded,
576 Deoptimization::Action_reinterpret));
577 } else {
578 push_object(element_klass);
579 }
580 }
581
582
583 // ------------------------------------------------------------------
584 // ciTypeFlow::StateVector::do_checkcast
585 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
586 bool will_link;
587 ciKlass* klass = str->get_klass(will_link);
588 if (!will_link) {
589 // VM's interpreter will not load 'klass' if object is null.
590 // Type flow after this block may still be needed in two situations:
591 // 1) C2 uses do_null_assert() and continues compilation for later blocks
592 // 2) C2 does an OSR compile in a later block (see bug 4778368).
593 pop_object();
594 do_null_assert(klass);
595 } else {
596 pop_object();
597 push_object(klass);
598 }
599 }
600
601 // ------------------------------------------------------------------
602 // ciTypeFlow::StateVector::do_getfield
603 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
604 // could add assert here for type of object.
605 pop_object();
606 do_getstatic(str);
607 }
608
609 // ------------------------------------------------------------------
610 // ciTypeFlow::StateVector::do_getstatic
611 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
612 bool will_link;
613 ciField* field = str->get_field(will_link);
614 if (!will_link) {
615 trap(str, field->holder(), str->get_field_holder_index());
616 } else {
617 ciType* field_type = field->type();
618 if (!field_type->is_loaded()) {
619 // Normally, we need the field's type to be loaded if we are to
620 // do anything interesting with its value.
621 // We used to do this: trap(str, str->get_field_signature_index());
622 //
623 // There is one good reason not to trap here. Execution can
624 // get past this "getfield" or "getstatic" if the value of
625 // the field is null. As long as the value is null, the class
626 // does not need to be loaded! The compiler must assume that
627 // the value of the unloaded class reference is null; if the code
628 // ever sees a non-null value, loading has occurred.
629 //
630 // This actually happens often enough to be annoying. If the
631 // compiler throws an uncommon trap at this bytecode, you can
632 // get an endless loop of recompilations, when all the code
633 // needs to do is load a series of null values. Also, a trap
634 // here can make an OSR entry point unreachable, triggering the
635 // assert on non_osr_block in ciTypeFlow::get_start_state.
636 // (See bug 4379915.)
637 do_null_assert(field_type->as_klass());
638 } else {
639 push_translate(field_type);
640 }
641 }
642 }
643
644 // ------------------------------------------------------------------
645 // ciTypeFlow::StateVector::do_invoke
646 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
647 bool has_receiver) {
648 bool will_link;
649 ciSignature* declared_signature = nullptr;
650 ciMethod* callee = str->get_method(will_link, &declared_signature);
651 assert(declared_signature != nullptr, "cannot be null");
652 if (!will_link) {
653 // We weren't able to find the method.
654 if (str->cur_bc() == Bytecodes::_invokedynamic) {
655 trap(str, nullptr,
656 Deoptimization::make_trap_request
657 (Deoptimization::Reason_uninitialized,
658 Deoptimization::Action_reinterpret));
659 } else {
660 ciKlass* unloaded_holder = callee->holder();
661 trap(str, unloaded_holder, str->get_method_holder_index());
662 }
663 } else {
664 // We are using the declared signature here because it might be
665 // different from the callee signature (Cf. invokedynamic and
666 // invokehandle).
667 ciSignatureStream sigstr(declared_signature);
668 const int arg_size = declared_signature->size();
669 const int stack_base = stack_size() - arg_size;
670 int i = 0;
671 for( ; !sigstr.at_return_type(); sigstr.next()) {
672 ciType* type = sigstr.type();
673 ciType* stack_type = type_at(stack(stack_base + i++));
674 // Do I want to check this type?
675 // assert(stack_type->is_subtype_of(type), "bad type for field value");
676 if (type->is_two_word()) {
677 ciType* stack_type2 = type_at(stack(stack_base + i++));
678 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
679 }
680 }
681 assert(arg_size == i, "must match");
682 for (int j = 0; j < arg_size; j++) {
683 pop();
684 }
685 if (has_receiver) {
686 // Check this?
687 pop_object();
688 }
689 assert(!sigstr.is_done(), "must have return type");
690 ciType* return_type = sigstr.type();
691 if (!return_type->is_void()) {
692 if (!return_type->is_loaded()) {
693 // As in do_getstatic(), generally speaking, we need the return type to
694 // be loaded if we are to do anything interesting with its value.
695 // We used to do this: trap(str, str->get_method_signature_index());
696 //
697 // We do not trap here since execution can get past this invoke if
698 // the return value is null. As long as the value is null, the class
699 // does not need to be loaded! The compiler must assume that
700 // the value of the unloaded class reference is null; if the code
701 // ever sees a non-null value, loading has occurred.
702 //
703 // See do_getstatic() for similar explanation, as well as bug 4684993.
704 do_null_assert(return_type->as_klass());
705 } else {
706 push_translate(return_type);
707 }
708 }
709 }
710 }
711
712 // ------------------------------------------------------------------
713 // ciTypeFlow::StateVector::do_jsr
714 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
715 push(ciReturnAddress::make(str->next_bci()));
716 }
717
718 // ------------------------------------------------------------------
719 // ciTypeFlow::StateVector::do_ldc
720 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
721 if (str->is_in_error()) {
722 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unhandled,
723 Deoptimization::Action_none));
724 return;
725 }
726 ciConstant con = str->get_constant();
727 if (con.is_valid()) {
728 int cp_index = str->get_constant_pool_index();
729 if (!con.is_loaded()) {
730 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unloaded,
731 Deoptimization::Action_reinterpret,
732 cp_index));
733 return;
734 }
735 BasicType basic_type = str->get_basic_type_for_constant_at(cp_index);
736 if (is_reference_type(basic_type)) {
737 ciObject* obj = con.as_object();
738 if (obj->is_null_object()) {
739 push_null();
740 } else {
741 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
742 push_object(obj->klass());
743 }
744 } else {
745 assert(basic_type == con.basic_type() || con.basic_type() == T_OBJECT,
746 "not a boxed form: %s vs %s", type2name(basic_type), type2name(con.basic_type()));
747 push_translate(ciType::make(basic_type));
748 }
749 } else {
750 // OutOfMemoryError in the CI while loading a String constant.
751 push_null();
752 outer()->record_failure("ldc did not link");
753 }
754 }
755
756 // ------------------------------------------------------------------
757 // ciTypeFlow::StateVector::do_multianewarray
758 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
759 int dimensions = str->get_dimensions();
760 bool will_link;
761 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
762 if (!will_link) {
763 trap(str, array_klass, str->get_klass_index());
764 } else {
765 for (int i = 0; i < dimensions; i++) {
766 pop_int();
767 }
768 push_object(array_klass);
769 }
770 }
771
772 // ------------------------------------------------------------------
773 // ciTypeFlow::StateVector::do_new
774 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
775 bool will_link;
776 ciKlass* klass = str->get_klass(will_link);
777 if (!will_link || str->is_unresolved_klass()) {
778 trap(str, klass, str->get_klass_index());
779 } else {
780 push_object(klass);
781 }
782 }
783
784 // ------------------------------------------------------------------
785 // ciTypeFlow::StateVector::do_newarray
786 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
787 pop_int();
788 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
789 push_object(klass);
790 }
791
792 // ------------------------------------------------------------------
793 // ciTypeFlow::StateVector::do_putfield
794 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
795 do_putstatic(str);
796 if (_trap_bci != -1) return; // unloaded field holder, etc.
797 // could add assert here for type of object.
798 pop_object();
799 }
800
801 // ------------------------------------------------------------------
802 // ciTypeFlow::StateVector::do_putstatic
803 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
804 bool will_link;
805 ciField* field = str->get_field(will_link);
806 if (!will_link) {
807 trap(str, field->holder(), str->get_field_holder_index());
808 } else {
809 ciType* field_type = field->type();
810 ciType* type = pop_value();
811 // Do I want to check this type?
812 // assert(type->is_subtype_of(field_type), "bad type for field value");
813 if (field_type->is_two_word()) {
814 ciType* type2 = pop_value();
815 assert(type2->is_two_word(), "must be 2nd half");
816 assert(type == half_type(type2), "must be 2nd half");
817 }
818 }
819 }
820
821 // ------------------------------------------------------------------
822 // ciTypeFlow::StateVector::do_ret
823 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
824 Cell index = local(str->get_index());
825
826 ciType* address = type_at(index);
827 assert(address->is_return_address(), "bad return address");
828 set_type_at(index, bottom_type());
829 }
830
831 // ------------------------------------------------------------------
832 // ciTypeFlow::StateVector::trap
833 //
834 // Stop interpretation of this path with a trap.
835 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
836 _trap_bci = str->cur_bci();
837 _trap_index = index;
838
839 // Log information about this trap:
840 CompileLog* log = outer()->env()->log();
841 if (log != nullptr) {
842 int mid = log->identify(outer()->method());
843 int kid = (klass == nullptr)? -1: log->identify(klass);
844 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
845 char buf[100];
846 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
847 index));
848 if (kid >= 0)
849 log->print(" klass='%d'", kid);
850 log->end_elem();
851 }
852 }
853
854 // ------------------------------------------------------------------
855 // ciTypeFlow::StateVector::do_null_assert
856 // Corresponds to graphKit::do_null_assert.
857 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
858 if (unloaded_klass->is_loaded()) {
859 // We failed to link, but we can still compute with this class,
860 // since it is loaded somewhere. The compiler will uncommon_trap
861 // if the object is not null, but the typeflow pass can not assume
862 // that the object will be null, otherwise it may incorrectly tell
863 // the parser that an object is known to be null. 4761344, 4807707
864 push_object(unloaded_klass);
865 } else {
866 // The class is not loaded anywhere. It is safe to model the
867 // null in the typestates, because we can compile in a null check
868 // which will deoptimize us if someone manages to load the
869 // class later.
870 push_null();
871 }
872 }
873
874
875 // ------------------------------------------------------------------
876 // ciTypeFlow::StateVector::apply_one_bytecode
877 //
878 // Apply the effect of one bytecode to this StateVector
879 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
880 _trap_bci = -1;
881 _trap_index = 0;
882
883 if (CITraceTypeFlow) {
884 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
885 Bytecodes::name(str->cur_bc()));
886 }
887
888 switch(str->cur_bc()) {
889 case Bytecodes::_aaload: do_aaload(str); break;
890
891 case Bytecodes::_aastore:
892 {
893 pop_object();
894 pop_int();
895 pop_objArray();
896 break;
897 }
898 case Bytecodes::_aconst_null:
899 {
900 push_null();
901 break;
902 }
903 case Bytecodes::_aload: load_local_object(str->get_index()); break;
904 case Bytecodes::_aload_0: load_local_object(0); break;
905 case Bytecodes::_aload_1: load_local_object(1); break;
906 case Bytecodes::_aload_2: load_local_object(2); break;
907 case Bytecodes::_aload_3: load_local_object(3); break;
908
909 case Bytecodes::_anewarray:
910 {
911 pop_int();
912 bool will_link;
913 ciKlass* element_klass = str->get_klass(will_link);
914 if (!will_link) {
915 trap(str, element_klass, str->get_klass_index());
916 } else {
917 push_object(ciObjArrayKlass::make(element_klass));
918 }
919 break;
920 }
921 case Bytecodes::_areturn:
922 case Bytecodes::_ifnonnull:
923 case Bytecodes::_ifnull:
924 {
925 pop_object();
926 break;
927 }
928 case Bytecodes::_monitorenter:
929 {
930 pop_object();
931 set_monitor_count(monitor_count() + 1);
932 break;
933 }
934 case Bytecodes::_monitorexit:
935 {
936 pop_object();
937 assert(monitor_count() > 0, "must be a monitor to exit from");
938 set_monitor_count(monitor_count() - 1);
939 break;
940 }
941 case Bytecodes::_arraylength:
942 {
943 pop_array();
944 push_int();
945 break;
946 }
947 case Bytecodes::_astore: store_local_object(str->get_index()); break;
948 case Bytecodes::_astore_0: store_local_object(0); break;
949 case Bytecodes::_astore_1: store_local_object(1); break;
950 case Bytecodes::_astore_2: store_local_object(2); break;
951 case Bytecodes::_astore_3: store_local_object(3); break;
952
953 case Bytecodes::_athrow:
954 {
955 NEEDS_CLEANUP;
956 pop_object();
957 break;
958 }
959 case Bytecodes::_baload:
960 case Bytecodes::_caload:
961 case Bytecodes::_iaload:
962 case Bytecodes::_saload:
963 {
964 pop_int();
965 ciTypeArrayKlass* array_klass = pop_typeArray();
966 // Put assert here for right type?
967 push_int();
968 break;
969 }
970 case Bytecodes::_bastore:
971 case Bytecodes::_castore:
972 case Bytecodes::_iastore:
973 case Bytecodes::_sastore:
974 {
975 pop_int();
976 pop_int();
977 pop_typeArray();
978 // assert here?
979 break;
980 }
981 case Bytecodes::_bipush:
982 case Bytecodes::_iconst_m1:
983 case Bytecodes::_iconst_0:
984 case Bytecodes::_iconst_1:
985 case Bytecodes::_iconst_2:
986 case Bytecodes::_iconst_3:
987 case Bytecodes::_iconst_4:
988 case Bytecodes::_iconst_5:
989 case Bytecodes::_sipush:
990 {
991 push_int();
992 break;
993 }
994 case Bytecodes::_checkcast: do_checkcast(str); break;
995
996 case Bytecodes::_d2f:
997 {
998 pop_double();
999 push_float();
1000 break;
1001 }
1002 case Bytecodes::_d2i:
1003 {
1004 pop_double();
1005 push_int();
1006 break;
1007 }
1008 case Bytecodes::_d2l:
1009 {
1010 pop_double();
1011 push_long();
1012 break;
1013 }
1014 case Bytecodes::_dadd:
1015 case Bytecodes::_ddiv:
1016 case Bytecodes::_dmul:
1017 case Bytecodes::_drem:
1018 case Bytecodes::_dsub:
1019 {
1020 pop_double();
1021 pop_double();
1022 push_double();
1023 break;
1024 }
1025 case Bytecodes::_daload:
1026 {
1027 pop_int();
1028 ciTypeArrayKlass* array_klass = pop_typeArray();
1029 // Put assert here for right type?
1030 push_double();
1031 break;
1032 }
1033 case Bytecodes::_dastore:
1034 {
1035 pop_double();
1036 pop_int();
1037 pop_typeArray();
1038 // assert here?
1039 break;
1040 }
1041 case Bytecodes::_dcmpg:
1042 case Bytecodes::_dcmpl:
1043 {
1044 pop_double();
1045 pop_double();
1046 push_int();
1047 break;
1048 }
1049 case Bytecodes::_dconst_0:
1050 case Bytecodes::_dconst_1:
1051 {
1052 push_double();
1053 break;
1054 }
1055 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1056 case Bytecodes::_dload_0: load_local_double(0); break;
1057 case Bytecodes::_dload_1: load_local_double(1); break;
1058 case Bytecodes::_dload_2: load_local_double(2); break;
1059 case Bytecodes::_dload_3: load_local_double(3); break;
1060
1061 case Bytecodes::_dneg:
1062 {
1063 pop_double();
1064 push_double();
1065 break;
1066 }
1067 case Bytecodes::_dreturn:
1068 {
1069 pop_double();
1070 break;
1071 }
1072 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1073 case Bytecodes::_dstore_0: store_local_double(0); break;
1074 case Bytecodes::_dstore_1: store_local_double(1); break;
1075 case Bytecodes::_dstore_2: store_local_double(2); break;
1076 case Bytecodes::_dstore_3: store_local_double(3); break;
1077
1078 case Bytecodes::_dup:
1079 {
1080 push(type_at_tos());
1081 break;
1082 }
1083 case Bytecodes::_dup_x1:
1084 {
1085 ciType* value1 = pop_value();
1086 ciType* value2 = pop_value();
1087 push(value1);
1088 push(value2);
1089 push(value1);
1090 break;
1091 }
1092 case Bytecodes::_dup_x2:
1093 {
1094 ciType* value1 = pop_value();
1095 ciType* value2 = pop_value();
1096 ciType* value3 = pop_value();
1097 push(value1);
1098 push(value3);
1099 push(value2);
1100 push(value1);
1101 break;
1102 }
1103 case Bytecodes::_dup2:
1104 {
1105 ciType* value1 = pop_value();
1106 ciType* value2 = pop_value();
1107 push(value2);
1108 push(value1);
1109 push(value2);
1110 push(value1);
1111 break;
1112 }
1113 case Bytecodes::_dup2_x1:
1114 {
1115 ciType* value1 = pop_value();
1116 ciType* value2 = pop_value();
1117 ciType* value3 = pop_value();
1118 push(value2);
1119 push(value1);
1120 push(value3);
1121 push(value2);
1122 push(value1);
1123 break;
1124 }
1125 case Bytecodes::_dup2_x2:
1126 {
1127 ciType* value1 = pop_value();
1128 ciType* value2 = pop_value();
1129 ciType* value3 = pop_value();
1130 ciType* value4 = pop_value();
1131 push(value2);
1132 push(value1);
1133 push(value4);
1134 push(value3);
1135 push(value2);
1136 push(value1);
1137 break;
1138 }
1139 case Bytecodes::_f2d:
1140 {
1141 pop_float();
1142 push_double();
1143 break;
1144 }
1145 case Bytecodes::_f2i:
1146 {
1147 pop_float();
1148 push_int();
1149 break;
1150 }
1151 case Bytecodes::_f2l:
1152 {
1153 pop_float();
1154 push_long();
1155 break;
1156 }
1157 case Bytecodes::_fadd:
1158 case Bytecodes::_fdiv:
1159 case Bytecodes::_fmul:
1160 case Bytecodes::_frem:
1161 case Bytecodes::_fsub:
1162 {
1163 pop_float();
1164 pop_float();
1165 push_float();
1166 break;
1167 }
1168 case Bytecodes::_faload:
1169 {
1170 pop_int();
1171 ciTypeArrayKlass* array_klass = pop_typeArray();
1172 // Put assert here.
1173 push_float();
1174 break;
1175 }
1176 case Bytecodes::_fastore:
1177 {
1178 pop_float();
1179 pop_int();
1180 ciTypeArrayKlass* array_klass = pop_typeArray();
1181 // Put assert here.
1182 break;
1183 }
1184 case Bytecodes::_fcmpg:
1185 case Bytecodes::_fcmpl:
1186 {
1187 pop_float();
1188 pop_float();
1189 push_int();
1190 break;
1191 }
1192 case Bytecodes::_fconst_0:
1193 case Bytecodes::_fconst_1:
1194 case Bytecodes::_fconst_2:
1195 {
1196 push_float();
1197 break;
1198 }
1199 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1200 case Bytecodes::_fload_0: load_local_float(0); break;
1201 case Bytecodes::_fload_1: load_local_float(1); break;
1202 case Bytecodes::_fload_2: load_local_float(2); break;
1203 case Bytecodes::_fload_3: load_local_float(3); break;
1204
1205 case Bytecodes::_fneg:
1206 {
1207 pop_float();
1208 push_float();
1209 break;
1210 }
1211 case Bytecodes::_freturn:
1212 {
1213 pop_float();
1214 break;
1215 }
1216 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1217 case Bytecodes::_fstore_0: store_local_float(0); break;
1218 case Bytecodes::_fstore_1: store_local_float(1); break;
1219 case Bytecodes::_fstore_2: store_local_float(2); break;
1220 case Bytecodes::_fstore_3: store_local_float(3); break;
1221
1222 case Bytecodes::_getfield: do_getfield(str); break;
1223 case Bytecodes::_getstatic: do_getstatic(str); break;
1224
1225 case Bytecodes::_goto:
1226 case Bytecodes::_goto_w:
1227 case Bytecodes::_nop:
1228 case Bytecodes::_return:
1229 {
1230 // do nothing.
1231 break;
1232 }
1233 case Bytecodes::_i2b:
1234 case Bytecodes::_i2c:
1235 case Bytecodes::_i2s:
1236 case Bytecodes::_ineg:
1237 {
1238 pop_int();
1239 push_int();
1240 break;
1241 }
1242 case Bytecodes::_i2d:
1243 {
1244 pop_int();
1245 push_double();
1246 break;
1247 }
1248 case Bytecodes::_i2f:
1249 {
1250 pop_int();
1251 push_float();
1252 break;
1253 }
1254 case Bytecodes::_i2l:
1255 {
1256 pop_int();
1257 push_long();
1258 break;
1259 }
1260 case Bytecodes::_iadd:
1261 case Bytecodes::_iand:
1262 case Bytecodes::_idiv:
1263 case Bytecodes::_imul:
1264 case Bytecodes::_ior:
1265 case Bytecodes::_irem:
1266 case Bytecodes::_ishl:
1267 case Bytecodes::_ishr:
1268 case Bytecodes::_isub:
1269 case Bytecodes::_iushr:
1270 case Bytecodes::_ixor:
1271 {
1272 pop_int();
1273 pop_int();
1274 push_int();
1275 break;
1276 }
1277 case Bytecodes::_if_acmpeq:
1278 case Bytecodes::_if_acmpne:
1279 {
1280 pop_object();
1281 pop_object();
1282 break;
1283 }
1284 case Bytecodes::_if_icmpeq:
1285 case Bytecodes::_if_icmpge:
1286 case Bytecodes::_if_icmpgt:
1287 case Bytecodes::_if_icmple:
1288 case Bytecodes::_if_icmplt:
1289 case Bytecodes::_if_icmpne:
1290 {
1291 pop_int();
1292 pop_int();
1293 break;
1294 }
1295 case Bytecodes::_ifeq:
1296 case Bytecodes::_ifle:
1297 case Bytecodes::_iflt:
1298 case Bytecodes::_ifge:
1299 case Bytecodes::_ifgt:
1300 case Bytecodes::_ifne:
1301 case Bytecodes::_ireturn:
1302 case Bytecodes::_lookupswitch:
1303 case Bytecodes::_tableswitch:
1304 {
1305 pop_int();
1306 break;
1307 }
1308 case Bytecodes::_iinc:
1309 {
1310 int lnum = str->get_index();
1311 check_int(local(lnum));
1312 store_to_local(lnum);
1313 break;
1314 }
1315 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1316 case Bytecodes::_iload_0: load_local_int(0); break;
1317 case Bytecodes::_iload_1: load_local_int(1); break;
1318 case Bytecodes::_iload_2: load_local_int(2); break;
1319 case Bytecodes::_iload_3: load_local_int(3); break;
1320
1321 case Bytecodes::_instanceof:
1322 {
1323 // Check for uncommon trap:
1324 do_checkcast(str);
1325 pop_object();
1326 push_int();
1327 break;
1328 }
1329 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1330 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1331 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1332 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1333 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1334
1335 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1336 case Bytecodes::_istore_0: store_local_int(0); break;
1337 case Bytecodes::_istore_1: store_local_int(1); break;
1338 case Bytecodes::_istore_2: store_local_int(2); break;
1339 case Bytecodes::_istore_3: store_local_int(3); break;
1340
1341 case Bytecodes::_jsr:
1342 case Bytecodes::_jsr_w: do_jsr(str); break;
1343
1344 case Bytecodes::_l2d:
1345 {
1346 pop_long();
1347 push_double();
1348 break;
1349 }
1350 case Bytecodes::_l2f:
1351 {
1352 pop_long();
1353 push_float();
1354 break;
1355 }
1356 case Bytecodes::_l2i:
1357 {
1358 pop_long();
1359 push_int();
1360 break;
1361 }
1362 case Bytecodes::_ladd:
1363 case Bytecodes::_land:
1364 case Bytecodes::_ldiv:
1365 case Bytecodes::_lmul:
1366 case Bytecodes::_lor:
1367 case Bytecodes::_lrem:
1368 case Bytecodes::_lsub:
1369 case Bytecodes::_lxor:
1370 {
1371 pop_long();
1372 pop_long();
1373 push_long();
1374 break;
1375 }
1376 case Bytecodes::_laload:
1377 {
1378 pop_int();
1379 ciTypeArrayKlass* array_klass = pop_typeArray();
1380 // Put assert here for right type?
1381 push_long();
1382 break;
1383 }
1384 case Bytecodes::_lastore:
1385 {
1386 pop_long();
1387 pop_int();
1388 pop_typeArray();
1389 // assert here?
1390 break;
1391 }
1392 case Bytecodes::_lcmp:
1393 {
1394 pop_long();
1395 pop_long();
1396 push_int();
1397 break;
1398 }
1399 case Bytecodes::_lconst_0:
1400 case Bytecodes::_lconst_1:
1401 {
1402 push_long();
1403 break;
1404 }
1405 case Bytecodes::_ldc:
1406 case Bytecodes::_ldc_w:
1407 case Bytecodes::_ldc2_w:
1408 {
1409 do_ldc(str);
1410 break;
1411 }
1412
1413 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1414 case Bytecodes::_lload_0: load_local_long(0); break;
1415 case Bytecodes::_lload_1: load_local_long(1); break;
1416 case Bytecodes::_lload_2: load_local_long(2); break;
1417 case Bytecodes::_lload_3: load_local_long(3); break;
1418
1419 case Bytecodes::_lneg:
1420 {
1421 pop_long();
1422 push_long();
1423 break;
1424 }
1425 case Bytecodes::_lreturn:
1426 {
1427 pop_long();
1428 break;
1429 }
1430 case Bytecodes::_lshl:
1431 case Bytecodes::_lshr:
1432 case Bytecodes::_lushr:
1433 {
1434 pop_int();
1435 pop_long();
1436 push_long();
1437 break;
1438 }
1439 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1440 case Bytecodes::_lstore_0: store_local_long(0); break;
1441 case Bytecodes::_lstore_1: store_local_long(1); break;
1442 case Bytecodes::_lstore_2: store_local_long(2); break;
1443 case Bytecodes::_lstore_3: store_local_long(3); break;
1444
1445 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1446
1447 case Bytecodes::_new: do_new(str); break;
1448
1449 case Bytecodes::_newarray: do_newarray(str); break;
1450
1451 case Bytecodes::_pop:
1452 {
1453 pop();
1454 break;
1455 }
1456 case Bytecodes::_pop2:
1457 {
1458 pop();
1459 pop();
1460 break;
1461 }
1462
1463 case Bytecodes::_putfield: do_putfield(str); break;
1464 case Bytecodes::_putstatic: do_putstatic(str); break;
1465
1466 case Bytecodes::_ret: do_ret(str); break;
1467
1468 case Bytecodes::_swap:
1469 {
1470 ciType* value1 = pop_value();
1471 ciType* value2 = pop_value();
1472 push(value1);
1473 push(value2);
1474 break;
1475 }
1476 case Bytecodes::_wide:
1477 default:
1478 {
1479 // The iterator should skip this.
1480 ShouldNotReachHere();
1481 break;
1482 }
1483 }
1484
1485 if (CITraceTypeFlow) {
1486 print_on(tty);
1487 }
1488
1489 return (_trap_bci != -1);
1490 }
1491
1492 #ifndef PRODUCT
1493 // ------------------------------------------------------------------
1494 // ciTypeFlow::StateVector::print_cell_on
1495 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1496 ciType* type = type_at(c);
1497 if (type == top_type()) {
1498 st->print("top");
1499 } else if (type == bottom_type()) {
1500 st->print("bottom");
1501 } else if (type == null_type()) {
1502 st->print("null");
1503 } else if (type == long2_type()) {
1504 st->print("long2");
1505 } else if (type == double2_type()) {
1506 st->print("double2");
1507 } else if (is_int(type)) {
1508 st->print("int");
1509 } else if (is_long(type)) {
1510 st->print("long");
1511 } else if (is_float(type)) {
1512 st->print("float");
1513 } else if (is_double(type)) {
1514 st->print("double");
1515 } else if (type->is_return_address()) {
1516 st->print("address(%d)", type->as_return_address()->bci());
1517 } else {
1518 if (type->is_klass()) {
1519 type->as_klass()->name()->print_symbol_on(st);
1520 } else {
1521 st->print("UNEXPECTED TYPE");
1522 type->print();
1523 }
1524 }
1525 }
1526
1527 // ------------------------------------------------------------------
1528 // ciTypeFlow::StateVector::print_on
1529 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1530 int num_locals = _outer->max_locals();
1531 int num_stack = stack_size();
1532 int num_monitors = monitor_count();
1533 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1534 if (num_stack >= 0) {
1535 int i;
1536 for (i = 0; i < num_locals; i++) {
1537 st->print(" local %2d : ", i);
1538 print_cell_on(st, local(i));
1539 st->cr();
1540 }
1541 for (i = 0; i < num_stack; i++) {
1542 st->print(" stack %2d : ", i);
1543 print_cell_on(st, stack(i));
1544 st->cr();
1545 }
1546 }
1547 }
1548 #endif
1549
1550
1551 // ------------------------------------------------------------------
1552 // ciTypeFlow::SuccIter::next
1553 //
1554 void ciTypeFlow::SuccIter::next() {
1555 int succ_ct = _pred->successors()->length();
1556 int next = _index + 1;
1557 if (next < succ_ct) {
1558 _index = next;
1559 _succ = _pred->successors()->at(next);
1560 return;
1561 }
1562 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1563 // Do not compile any code for unloaded exception types.
1564 // Following compiler passes are responsible for doing this also.
1565 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1566 if (exception_klass->is_loaded()) {
1567 _index = next;
1568 _succ = _pred->exceptions()->at(i);
1569 return;
1570 }
1571 next++;
1572 }
1573 _index = -1;
1574 _succ = nullptr;
1575 }
1576
1577 // ------------------------------------------------------------------
1578 // ciTypeFlow::SuccIter::set_succ
1579 //
1580 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1581 int succ_ct = _pred->successors()->length();
1582 if (_index < succ_ct) {
1583 _pred->successors()->at_put(_index, succ);
1584 } else {
1585 int idx = _index - succ_ct;
1586 _pred->exceptions()->at_put(idx, succ);
1587 }
1588 }
1589
1590 // ciTypeFlow::Block
1591 //
1592 // A basic block.
1593
1594 // ------------------------------------------------------------------
1595 // ciTypeFlow::Block::Block
1596 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1597 ciBlock *ciblk,
1598 ciTypeFlow::JsrSet* jsrs) : _predecessors(outer->arena(), 1, 0, nullptr) {
1599 _ciblock = ciblk;
1600 _exceptions = nullptr;
1601 _exc_klasses = nullptr;
1602 _successors = nullptr;
1603 _state = new (outer->arena()) StateVector(outer);
1604 JsrSet* new_jsrs =
1605 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1606 jsrs->copy_into(new_jsrs);
1607 _jsrs = new_jsrs;
1608 _next = nullptr;
1609 _on_work_list = false;
1610 _backedge_copy = false;
1611 _has_monitorenter = false;
1612 _trap_bci = -1;
1613 _trap_index = 0;
1614 df_init();
1615
1616 if (CITraceTypeFlow) {
1617 tty->print_cr(">> Created new block");
1618 print_on(tty);
1619 }
1620
1621 assert(this->outer() == outer, "outer link set up");
1622 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1623 }
1624
1625 // ------------------------------------------------------------------
1626 // ciTypeFlow::Block::df_init
1627 void ciTypeFlow::Block::df_init() {
1628 _pre_order = -1; assert(!has_pre_order(), "");
1629 _post_order = -1; assert(!has_post_order(), "");
1630 _loop = nullptr;
1631 _irreducible_loop_head = false;
1632 _irreducible_loop_secondary_entry = false;
1633 _rpo_next = nullptr;
1634 }
1635
1636 // ------------------------------------------------------------------
1637 // ciTypeFlow::Block::successors
1638 //
1639 // Get the successors for this Block.
1640 GrowableArray<ciTypeFlow::Block*>*
1641 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1642 ciTypeFlow::StateVector* state,
1643 ciTypeFlow::JsrSet* jsrs) {
1644 if (_successors == nullptr) {
1645 if (CITraceTypeFlow) {
1646 tty->print(">> Computing successors for block ");
1647 print_value_on(tty);
1648 tty->cr();
1649 }
1650
1651 ciTypeFlow* analyzer = outer();
1652 Arena* arena = analyzer->arena();
1653 Block* block = nullptr;
1654 bool has_successor = !has_trap() &&
1655 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1656 if (!has_successor) {
1657 _successors =
1658 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1659 // No successors
1660 } else if (control() == ciBlock::fall_through_bci) {
1661 assert(str->cur_bci() == limit(), "bad block end");
1662 // This block simply falls through to the next.
1663 _successors =
1664 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1665
1666 Block* block = analyzer->block_at(limit(), _jsrs);
1667 assert(_successors->length() == FALL_THROUGH, "");
1668 _successors->append(block);
1669 } else {
1670 int current_bci = str->cur_bci();
1671 int next_bci = str->next_bci();
1672 int branch_bci = -1;
1673 Block* target = nullptr;
1674 assert(str->next_bci() == limit(), "bad block end");
1675 // This block is not a simple fall-though. Interpret
1676 // the current bytecode to find our successors.
1677 switch (str->cur_bc()) {
1678 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1679 case Bytecodes::_iflt: case Bytecodes::_ifge:
1680 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1681 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1682 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1683 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1684 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1685 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1686 // Our successors are the branch target and the next bci.
1687 branch_bci = str->get_dest();
1688 _successors =
1689 new (arena) GrowableArray<Block*>(arena, 2, 0, nullptr);
1690 assert(_successors->length() == IF_NOT_TAKEN, "");
1691 _successors->append(analyzer->block_at(next_bci, jsrs));
1692 assert(_successors->length() == IF_TAKEN, "");
1693 _successors->append(analyzer->block_at(branch_bci, jsrs));
1694 break;
1695
1696 case Bytecodes::_goto:
1697 branch_bci = str->get_dest();
1698 _successors =
1699 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1700 assert(_successors->length() == GOTO_TARGET, "");
1701 _successors->append(analyzer->block_at(branch_bci, jsrs));
1702 break;
1703
1704 case Bytecodes::_jsr:
1705 branch_bci = str->get_dest();
1706 _successors =
1707 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1708 assert(_successors->length() == GOTO_TARGET, "");
1709 _successors->append(analyzer->block_at(branch_bci, jsrs));
1710 break;
1711
1712 case Bytecodes::_goto_w:
1713 case Bytecodes::_jsr_w:
1714 _successors =
1715 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1716 assert(_successors->length() == GOTO_TARGET, "");
1717 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1718 break;
1719
1720 case Bytecodes::_tableswitch: {
1721 Bytecode_tableswitch tableswitch(str);
1722
1723 int len = tableswitch.length();
1724 _successors =
1725 new (arena) GrowableArray<Block*>(arena, len+1, 0, nullptr);
1726 int bci = current_bci + tableswitch.default_offset();
1727 Block* block = analyzer->block_at(bci, jsrs);
1728 assert(_successors->length() == SWITCH_DEFAULT, "");
1729 _successors->append(block);
1730 while (--len >= 0) {
1731 int bci = current_bci + tableswitch.dest_offset_at(len);
1732 block = analyzer->block_at(bci, jsrs);
1733 assert(_successors->length() >= SWITCH_CASES, "");
1734 _successors->append_if_missing(block);
1735 }
1736 break;
1737 }
1738
1739 case Bytecodes::_lookupswitch: {
1740 Bytecode_lookupswitch lookupswitch(str);
1741
1742 int npairs = lookupswitch.number_of_pairs();
1743 _successors =
1744 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, nullptr);
1745 int bci = current_bci + lookupswitch.default_offset();
1746 Block* block = analyzer->block_at(bci, jsrs);
1747 assert(_successors->length() == SWITCH_DEFAULT, "");
1748 _successors->append(block);
1749 while(--npairs >= 0) {
1750 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1751 int bci = current_bci + pair.offset();
1752 Block* block = analyzer->block_at(bci, jsrs);
1753 assert(_successors->length() >= SWITCH_CASES, "");
1754 _successors->append_if_missing(block);
1755 }
1756 break;
1757 }
1758
1759 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1760 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1761 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1762 case Bytecodes::_return:
1763 _successors =
1764 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1765 // No successors
1766 break;
1767
1768 case Bytecodes::_ret: {
1769 _successors =
1770 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1771
1772 Cell local = state->local(str->get_index());
1773 ciType* return_address = state->type_at(local);
1774 assert(return_address->is_return_address(), "verify: wrong type");
1775 int bci = return_address->as_return_address()->bci();
1776 assert(_successors->length() == GOTO_TARGET, "");
1777 _successors->append(analyzer->block_at(bci, jsrs));
1778 break;
1779 }
1780
1781 case Bytecodes::_wide:
1782 default:
1783 ShouldNotReachHere();
1784 break;
1785 }
1786 }
1787
1788 // Set predecessor information
1789 for (int i = 0; i < _successors->length(); i++) {
1790 Block* block = _successors->at(i);
1791 block->predecessors()->append(this);
1792 }
1793 }
1794 return _successors;
1795 }
1796
1797 // ------------------------------------------------------------------
1798 // ciTypeFlow::Block:compute_exceptions
1799 //
1800 // Compute the exceptional successors and types for this Block.
1801 void ciTypeFlow::Block::compute_exceptions() {
1802 assert(_exceptions == nullptr && _exc_klasses == nullptr, "repeat");
1803
1804 if (CITraceTypeFlow) {
1805 tty->print(">> Computing exceptions for block ");
1806 print_value_on(tty);
1807 tty->cr();
1808 }
1809
1810 ciTypeFlow* analyzer = outer();
1811 Arena* arena = analyzer->arena();
1812
1813 // Any bci in the block will do.
1814 ciExceptionHandlerStream str(analyzer->method(), start());
1815
1816 // Allocate our growable arrays.
1817 int exc_count = str.count();
1818 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, nullptr);
1819 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1820 0, nullptr);
1821
1822 for ( ; !str.is_done(); str.next()) {
1823 ciExceptionHandler* handler = str.handler();
1824 int bci = handler->handler_bci();
1825 ciInstanceKlass* klass = nullptr;
1826 if (bci == -1) {
1827 // There is no catch all. It is possible to exit the method.
1828 break;
1829 }
1830 if (handler->is_catch_all()) {
1831 klass = analyzer->env()->Throwable_klass();
1832 } else {
1833 klass = handler->catch_klass();
1834 }
1835 Block* block = analyzer->block_at(bci, _jsrs);
1836 _exceptions->append(block);
1837 block->predecessors()->append(this);
1838 _exc_klasses->append(klass);
1839 }
1840 }
1841
1842 // ------------------------------------------------------------------
1843 // ciTypeFlow::Block::set_backedge_copy
1844 // Use this only to make a pre-existing public block into a backedge copy.
1845 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1846 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1847 _backedge_copy = z;
1848 }
1849
1850 // Analogous to PhaseIdealLoop::is_in_irreducible_loop
1851 bool ciTypeFlow::Block::is_in_irreducible_loop() const {
1852 if (!outer()->has_irreducible_entry()) {
1853 return false; // No irreducible loop in method.
1854 }
1855 Loop* lp = loop(); // Innermost loop containing block.
1856 if (lp == nullptr) {
1857 assert(!is_post_visited(), "must have enclosing loop once post-visited");
1858 return false; // Not yet processed, so we do not know, yet.
1859 }
1860 // Walk all the way up the loop-tree, search for an irreducible loop.
1861 do {
1862 if (lp->is_irreducible()) {
1863 return true; // We are in irreducible loop.
1864 }
1865 if (lp->head()->pre_order() == 0) {
1866 return false; // Found root loop, terminate.
1867 }
1868 lp = lp->parent();
1869 } while (lp != nullptr);
1870 // We have "lp->parent() == nullptr", which happens only for infinite loops,
1871 // where no parent is attached to the loop. We did not find any irreducible
1872 // loop from this block out to lp. Thus lp only has one entry, and no exit
1873 // (it is infinite and reducible). We can always rewrite an infinite loop
1874 // that is nested inside other loops:
1875 // while(condition) { infinite_loop; }
1876 // with an equivalent program where the infinite loop is an outermost loop
1877 // that is not nested in any loop:
1878 // while(condition) { break; } infinite_loop;
1879 // Thus, we can understand lp as an outermost loop, and can terminate and
1880 // conclude: this block is in no irreducible loop.
1881 return false;
1882 }
1883
1884 // ------------------------------------------------------------------
1885 // ciTypeFlow::Block::is_clonable_exit
1886 //
1887 // At most 2 normal successors, one of which continues looping,
1888 // and all exceptional successors must exit.
1889 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1890 int normal_cnt = 0;
1891 int in_loop_cnt = 0;
1892 for (SuccIter iter(this); !iter.done(); iter.next()) {
1893 Block* succ = iter.succ();
1894 if (iter.is_normal_ctrl()) {
1895 if (++normal_cnt > 2) return false;
1896 if (lp->contains(succ->loop())) {
1897 if (++in_loop_cnt > 1) return false;
1898 }
1899 } else {
1900 if (lp->contains(succ->loop())) return false;
1901 }
1902 }
1903 return in_loop_cnt == 1;
1904 }
1905
1906 // ------------------------------------------------------------------
1907 // ciTypeFlow::Block::looping_succ
1908 //
1909 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1910 assert(successors()->length() <= 2, "at most 2 normal successors");
1911 for (SuccIter iter(this); !iter.done(); iter.next()) {
1912 Block* succ = iter.succ();
1913 if (lp->contains(succ->loop())) {
1914 return succ;
1915 }
1916 }
1917 return nullptr;
1918 }
1919
1920 #ifndef PRODUCT
1921 // ------------------------------------------------------------------
1922 // ciTypeFlow::Block::print_value_on
1923 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1924 if (has_pre_order()) st->print("#%-2d ", pre_order());
1925 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1926 st->print("[%d - %d)", start(), limit());
1927 if (is_loop_head()) st->print(" lphd");
1928 if (is_in_irreducible_loop()) st->print(" in_irred");
1929 if (is_irreducible_loop_head()) st->print(" irred_head");
1930 if (is_irreducible_loop_secondary_entry()) st->print(" irred_entry");
1931 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1932 if (is_backedge_copy()) st->print("/backedge_copy");
1933 }
1934
1935 // ------------------------------------------------------------------
1936 // ciTypeFlow::Block::print_on
1937 void ciTypeFlow::Block::print_on(outputStream* st) const {
1938 if ((Verbose || WizardMode) && (limit() >= 0)) {
1939 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1940 outer()->method()->print_codes_on(start(), limit(), st);
1941 }
1942 st->print_cr(" ==================================================== ");
1943 st->print (" ");
1944 print_value_on(st);
1945 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1946 if (loop() && loop()->parent() != nullptr) {
1947 st->print(" loops:");
1948 Loop* lp = loop();
1949 do {
1950 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1951 if (lp->is_irreducible()) st->print("(ir)");
1952 lp = lp->parent();
1953 } while (lp->parent() != nullptr);
1954 }
1955 st->cr();
1956 _state->print_on(st);
1957 if (_successors == nullptr) {
1958 st->print_cr(" No successor information");
1959 } else {
1960 int num_successors = _successors->length();
1961 st->print_cr(" Successors : %d", num_successors);
1962 for (int i = 0; i < num_successors; i++) {
1963 Block* successor = _successors->at(i);
1964 st->print(" ");
1965 successor->print_value_on(st);
1966 st->cr();
1967 }
1968 }
1969 if (_predecessors.is_empty()) {
1970 st->print_cr(" No predecessor information");
1971 } else {
1972 int num_predecessors = _predecessors.length();
1973 st->print_cr(" Predecessors : %d", num_predecessors);
1974 for (int i = 0; i < num_predecessors; i++) {
1975 Block* predecessor = _predecessors.at(i);
1976 st->print(" ");
1977 predecessor->print_value_on(st);
1978 st->cr();
1979 }
1980 }
1981 if (_exceptions == nullptr) {
1982 st->print_cr(" No exception information");
1983 } else {
1984 int num_exceptions = _exceptions->length();
1985 st->print_cr(" Exceptions : %d", num_exceptions);
1986 for (int i = 0; i < num_exceptions; i++) {
1987 Block* exc_succ = _exceptions->at(i);
1988 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1989 st->print(" ");
1990 exc_succ->print_value_on(st);
1991 st->print(" -- ");
1992 exc_klass->name()->print_symbol_on(st);
1993 st->cr();
1994 }
1995 }
1996 if (has_trap()) {
1997 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1998 }
1999 st->print_cr(" ==================================================== ");
2000 }
2001 #endif
2002
2003 #ifndef PRODUCT
2004 // ------------------------------------------------------------------
2005 // ciTypeFlow::LocalSet::print_on
2006 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2007 st->print("{");
2008 for (int i = 0; i < max; i++) {
2009 if (test(i)) st->print(" %d", i);
2010 }
2011 if (limit > max) {
2012 st->print(" %d..%d ", max, limit);
2013 }
2014 st->print(" }");
2015 }
2016 #endif
2017
2018 // ciTypeFlow
2019 //
2020 // This is a pass over the bytecodes which computes the following:
2021 // basic block structure
2022 // interpreter type-states (a la the verifier)
2023
2024 // ------------------------------------------------------------------
2025 // ciTypeFlow::ciTypeFlow
2026 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2027 _env = env;
2028 _method = method;
2029 _has_irreducible_entry = false;
2030 _osr_bci = osr_bci;
2031 _failure_reason = nullptr;
2032 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2033 _work_list = nullptr;
2034
2035 int ciblock_count = _method->get_method_blocks()->num_blocks();
2036 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, ciblock_count);
2037 for (int i = 0; i < ciblock_count; i++) {
2038 _idx_to_blocklist[i] = nullptr;
2039 }
2040 _block_map = nullptr; // until all blocks are seen
2041 _jsr_records = nullptr;
2042 }
2043
2044 // ------------------------------------------------------------------
2045 // ciTypeFlow::work_list_next
2046 //
2047 // Get the next basic block from our work list.
2048 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2049 assert(!work_list_empty(), "work list must not be empty");
2050 Block* next_block = _work_list;
2051 _work_list = next_block->next();
2052 next_block->set_next(nullptr);
2053 next_block->set_on_work_list(false);
2054 return next_block;
2055 }
2056
2057 // ------------------------------------------------------------------
2058 // ciTypeFlow::add_to_work_list
2059 //
2060 // Add a basic block to our work list.
2061 // List is sorted by decreasing postorder sort (same as increasing RPO)
2062 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2063 assert(!block->is_on_work_list(), "must not already be on work list");
2064
2065 if (CITraceTypeFlow) {
2066 tty->print(">> Adding block ");
2067 block->print_value_on(tty);
2068 tty->print_cr(" to the work list : ");
2069 }
2070
2071 block->set_on_work_list(true);
2072
2073 // decreasing post order sort
2074
2075 Block* prev = nullptr;
2076 Block* current = _work_list;
2077 int po = block->post_order();
2078 while (current != nullptr) {
2079 if (!current->has_post_order() || po > current->post_order())
2080 break;
2081 prev = current;
2082 current = current->next();
2083 }
2084 if (prev == nullptr) {
2085 block->set_next(_work_list);
2086 _work_list = block;
2087 } else {
2088 block->set_next(current);
2089 prev->set_next(block);
2090 }
2091
2092 if (CITraceTypeFlow) {
2093 tty->cr();
2094 }
2095 }
2096
2097 // ------------------------------------------------------------------
2098 // ciTypeFlow::block_at
2099 //
2100 // Return the block beginning at bci which has a JsrSet compatible
2101 // with jsrs.
2102 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2103 // First find the right ciBlock.
2104 if (CITraceTypeFlow) {
2105 tty->print(">> Requesting block for %d/", bci);
2106 jsrs->print_on(tty);
2107 tty->cr();
2108 }
2109
2110 ciBlock* ciblk = _method->get_method_blocks()->block_containing(bci);
2111 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2112 Block* block = get_block_for(ciblk->index(), jsrs, option);
2113
2114 assert(block == nullptr? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2115
2116 if (CITraceTypeFlow) {
2117 if (block != nullptr) {
2118 tty->print(">> Found block ");
2119 block->print_value_on(tty);
2120 tty->cr();
2121 } else {
2122 tty->print_cr(">> No such block.");
2123 }
2124 }
2125
2126 return block;
2127 }
2128
2129 // ------------------------------------------------------------------
2130 // ciTypeFlow::make_jsr_record
2131 //
2132 // Make a JsrRecord for a given (entry, return) pair, if such a record
2133 // does not already exist.
2134 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2135 int return_address) {
2136 if (_jsr_records == nullptr) {
2137 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2138 2,
2139 0,
2140 nullptr);
2141 }
2142 JsrRecord* record = nullptr;
2143 int len = _jsr_records->length();
2144 for (int i = 0; i < len; i++) {
2145 JsrRecord* record = _jsr_records->at(i);
2146 if (record->entry_address() == entry_address &&
2147 record->return_address() == return_address) {
2148 return record;
2149 }
2150 }
2151
2152 record = new (arena()) JsrRecord(entry_address, return_address);
2153 _jsr_records->append(record);
2154 return record;
2155 }
2156
2157 // ------------------------------------------------------------------
2158 // ciTypeFlow::flow_exceptions
2159 //
2160 // Merge the current state into all exceptional successors at the
2161 // current point in the code.
2162 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2163 GrowableArray<ciInstanceKlass*>* exc_klasses,
2164 ciTypeFlow::StateVector* state) {
2165 int len = exceptions->length();
2166 assert(exc_klasses->length() == len, "must have same length");
2167 for (int i = 0; i < len; i++) {
2168 Block* block = exceptions->at(i);
2169 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2170
2171 if (!exception_klass->is_loaded()) {
2172 // Do not compile any code for unloaded exception types.
2173 // Following compiler passes are responsible for doing this also.
2174 continue;
2175 }
2176
2177 if (block->meet_exception(exception_klass, state)) {
2178 // Block was modified and has PO. Add it to the work list.
2179 if (block->has_post_order() &&
2180 !block->is_on_work_list()) {
2181 add_to_work_list(block);
2182 }
2183 }
2184 }
2185 }
2186
2187 // ------------------------------------------------------------------
2188 // ciTypeFlow::flow_successors
2189 //
2190 // Merge the current state into all successors at the current point
2191 // in the code.
2192 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2193 ciTypeFlow::StateVector* state) {
2194 int len = successors->length();
2195 for (int i = 0; i < len; i++) {
2196 Block* block = successors->at(i);
2197 if (block->meet(state)) {
2198 // Block was modified and has PO. Add it to the work list.
2199 if (block->has_post_order() &&
2200 !block->is_on_work_list()) {
2201 add_to_work_list(block);
2202 }
2203 }
2204 }
2205 }
2206
2207 // ------------------------------------------------------------------
2208 // ciTypeFlow::can_trap
2209 //
2210 // Tells if a given instruction is able to generate an exception edge.
2211 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2212 // Cf. GenerateOopMap::do_exception_edge.
2213 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2214
2215 switch (str.cur_bc()) {
2216 case Bytecodes::_ldc:
2217 case Bytecodes::_ldc_w:
2218 case Bytecodes::_ldc2_w:
2219 return str.is_in_error() || !str.get_constant().is_loaded();
2220
2221 case Bytecodes::_aload_0:
2222 // These bytecodes can trap for rewriting. We need to assume that
2223 // they do not throw exceptions to make the monitor analysis work.
2224 return false;
2225
2226 case Bytecodes::_ireturn:
2227 case Bytecodes::_lreturn:
2228 case Bytecodes::_freturn:
2229 case Bytecodes::_dreturn:
2230 case Bytecodes::_areturn:
2231 case Bytecodes::_return:
2232 // We can assume the monitor stack is empty in this analysis.
2233 return false;
2234
2235 case Bytecodes::_monitorexit:
2236 // We can assume monitors are matched in this analysis.
2237 return false;
2238
2239 default:
2240 return true;
2241 }
2242 }
2243
2244 // ------------------------------------------------------------------
2245 // ciTypeFlow::clone_loop_heads
2246 //
2247 // Clone the loop heads
2248 bool ciTypeFlow::clone_loop_heads(StateVector* temp_vector, JsrSet* temp_set) {
2249 bool rslt = false;
2250 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2251 Loop* lp = iter.current();
2252 Block* head = lp->head();
2253 if (lp == loop_tree_root() ||
2254 lp->is_irreducible() ||
2255 !head->is_clonable_exit(lp))
2256 continue;
2257
2258 // Avoid BoxLock merge.
2259 if (EliminateNestedLocks && head->has_monitorenter())
2260 continue;
2261
2262 // check not already cloned
2263 if (head->backedge_copy_count() != 0)
2264 continue;
2265
2266 // Don't clone head of OSR loop to get correct types in start block.
2267 if (is_osr_flow() && head->start() == start_bci())
2268 continue;
2269
2270 // check _no_ shared head below us
2271 Loop* ch;
2272 for (ch = lp->child(); ch != nullptr && ch->head() != head; ch = ch->sibling());
2273 if (ch != nullptr)
2274 continue;
2275
2276 // Clone head
2277 Block* new_head = head->looping_succ(lp);
2278 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2279 // Update lp's info
2280 clone->set_loop(lp);
2281 lp->set_head(new_head);
2282 lp->set_tail(clone);
2283 // And move original head into outer loop
2284 head->set_loop(lp->parent());
2285
2286 rslt = true;
2287 }
2288 return rslt;
2289 }
2290
2291 // ------------------------------------------------------------------
2292 // ciTypeFlow::clone_loop_head
2293 //
2294 // Clone lp's head and replace tail's successors with clone.
2295 //
2296 // |
2297 // v
2298 // head <-> body
2299 // |
2300 // v
2301 // exit
2302 //
2303 // new_head
2304 //
2305 // |
2306 // v
2307 // head ----------\
2308 // | |
2309 // | v
2310 // | clone <-> body
2311 // | |
2312 // | /--/
2313 // | |
2314 // v v
2315 // exit
2316 //
2317 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2318 Block* head = lp->head();
2319 Block* tail = lp->tail();
2320 if (CITraceTypeFlow) {
2321 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2322 tty->print(" for predecessor "); tail->print_value_on(tty);
2323 tty->cr();
2324 }
2325 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2326 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2327
2328 assert(!clone->has_pre_order(), "just created");
2329 clone->set_next_pre_order();
2330
2331 // Accumulate profiled count for all backedges that share this loop's head
2332 int total_count = lp->profiled_count();
2333 for (Loop* lp1 = lp->parent(); lp1 != nullptr; lp1 = lp1->parent()) {
2334 for (Loop* lp2 = lp1; lp2 != nullptr; lp2 = lp2->sibling()) {
2335 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2336 total_count += lp2->profiled_count();
2337 }
2338 }
2339 }
2340 // Have the most frequent ones branch to the clone instead
2341 int count = 0;
2342 int loops_with_shared_head = 0;
2343 Block* latest_tail = tail;
2344 bool done = false;
2345 for (Loop* lp1 = lp; lp1 != nullptr && !done; lp1 = lp1->parent()) {
2346 for (Loop* lp2 = lp1; lp2 != nullptr && !done; lp2 = lp2->sibling()) {
2347 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2348 count += lp2->profiled_count();
2349 if (lp2->tail()->post_order() < latest_tail->post_order()) {
2350 latest_tail = lp2->tail();
2351 }
2352 loops_with_shared_head++;
2353 for (SuccIter iter(lp2->tail()); !iter.done(); iter.next()) {
2354 if (iter.succ() == head) {
2355 iter.set_succ(clone);
2356 // Update predecessor information
2357 head->predecessors()->remove(lp2->tail());
2358 clone->predecessors()->append(lp2->tail());
2359 }
2360 }
2361 flow_block(lp2->tail(), temp_vector, temp_set);
2362 if (lp2->head() == lp2->tail()) {
2363 // For self-loops, clone->head becomes clone->clone
2364 flow_block(clone, temp_vector, temp_set);
2365 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2366 if (iter.succ() == lp2->head()) {
2367 iter.set_succ(clone);
2368 // Update predecessor information
2369 lp2->head()->predecessors()->remove(clone);
2370 clone->predecessors()->append(clone);
2371 break;
2372 }
2373 }
2374 }
2375 if (total_count == 0 || count > (total_count * .9)) {
2376 done = true;
2377 }
2378 }
2379 }
2380 }
2381 assert(loops_with_shared_head >= 1, "at least one new");
2382 clone->set_rpo_next(latest_tail->rpo_next());
2383 latest_tail->set_rpo_next(clone);
2384 flow_block(clone, temp_vector, temp_set);
2385
2386 return clone;
2387 }
2388
2389 // ------------------------------------------------------------------
2390 // ciTypeFlow::flow_block
2391 //
2392 // Interpret the effects of the bytecodes on the incoming state
2393 // vector of a basic block. Push the changed state to succeeding
2394 // basic blocks.
2395 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2396 ciTypeFlow::StateVector* state,
2397 ciTypeFlow::JsrSet* jsrs) {
2398 if (CITraceTypeFlow) {
2399 tty->print("\n>> ANALYZING BLOCK : ");
2400 tty->cr();
2401 block->print_on(tty);
2402 }
2403 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2404
2405 int start = block->start();
2406 int limit = block->limit();
2407 int control = block->control();
2408 if (control != ciBlock::fall_through_bci) {
2409 limit = control;
2410 }
2411
2412 // Grab the state from the current block.
2413 block->copy_state_into(state);
2414 state->def_locals()->clear();
2415
2416 GrowableArray<Block*>* exceptions = block->exceptions();
2417 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2418 bool has_exceptions = exceptions->length() > 0;
2419
2420 bool exceptions_used = false;
2421
2422 ciBytecodeStream str(method());
2423 str.reset_to_bci(start);
2424 Bytecodes::Code code;
2425 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2426 str.cur_bci() < limit) {
2427 // Check for exceptional control flow from this point.
2428 if (has_exceptions && can_trap(str)) {
2429 flow_exceptions(exceptions, exc_klasses, state);
2430 exceptions_used = true;
2431 }
2432 // Apply the effects of the current bytecode to our state.
2433 bool res = state->apply_one_bytecode(&str);
2434
2435 // Watch for bailouts.
2436 if (failing()) return;
2437
2438 if (str.cur_bc() == Bytecodes::_monitorenter) {
2439 block->set_has_monitorenter();
2440 }
2441
2442 if (res) {
2443
2444 // We have encountered a trap. Record it in this block.
2445 block->set_trap(state->trap_bci(), state->trap_index());
2446
2447 if (CITraceTypeFlow) {
2448 tty->print_cr(">> Found trap");
2449 block->print_on(tty);
2450 }
2451
2452 // Save set of locals defined in this block
2453 block->def_locals()->add(state->def_locals());
2454
2455 // Record (no) successors.
2456 block->successors(&str, state, jsrs);
2457
2458 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2459
2460 // Discontinue interpretation of this Block.
2461 return;
2462 }
2463 }
2464
2465 GrowableArray<Block*>* successors = nullptr;
2466 if (control != ciBlock::fall_through_bci) {
2467 // Check for exceptional control flow from this point.
2468 if (has_exceptions && can_trap(str)) {
2469 flow_exceptions(exceptions, exc_klasses, state);
2470 exceptions_used = true;
2471 }
2472
2473 // Fix the JsrSet to reflect effect of the bytecode.
2474 block->copy_jsrs_into(jsrs);
2475 jsrs->apply_control(this, &str, state);
2476
2477 // Find successor edges based on old state and new JsrSet.
2478 successors = block->successors(&str, state, jsrs);
2479
2480 // Apply the control changes to the state.
2481 state->apply_one_bytecode(&str);
2482 } else {
2483 // Fall through control
2484 successors = block->successors(&str, nullptr, nullptr);
2485 }
2486
2487 // Save set of locals defined in this block
2488 block->def_locals()->add(state->def_locals());
2489
2490 // Remove untaken exception paths
2491 if (!exceptions_used)
2492 exceptions->clear();
2493
2494 // Pass our state to successors.
2495 flow_successors(successors, state);
2496 }
2497
2498 // ------------------------------------------------------------------
2499 // ciTypeFlow::PreOrderLoops::next
2500 //
2501 // Advance to next loop tree using a preorder, left-to-right traversal.
2502 void ciTypeFlow::PreorderLoops::next() {
2503 assert(!done(), "must not be done.");
2504 if (_current->child() != nullptr) {
2505 _current = _current->child();
2506 } else if (_current->sibling() != nullptr) {
2507 _current = _current->sibling();
2508 } else {
2509 while (_current != _root && _current->sibling() == nullptr) {
2510 _current = _current->parent();
2511 }
2512 if (_current == _root) {
2513 _current = nullptr;
2514 assert(done(), "must be done.");
2515 } else {
2516 assert(_current->sibling() != nullptr, "must be more to do");
2517 _current = _current->sibling();
2518 }
2519 }
2520 }
2521
2522 // If the tail is a branch to the head, retrieve how many times that path was taken from profiling
2523 int ciTypeFlow::Loop::profiled_count() {
2524 if (_profiled_count >= 0) {
2525 return _profiled_count;
2526 }
2527 ciMethodData* methodData = outer()->method()->method_data();
2528 if (!methodData->is_mature()) {
2529 _profiled_count = 0;
2530 return 0;
2531 }
2532 ciTypeFlow::Block* tail = this->tail();
2533 if (tail->control() == -1 || tail->has_trap()) {
2534 _profiled_count = 0;
2535 return 0;
2536 }
2537
2538 ciProfileData* data = methodData->bci_to_data(tail->control());
2539
2540 if (data == nullptr || !data->is_JumpData()) {
2541 _profiled_count = 0;
2542 return 0;
2543 }
2544
2545 ciBytecodeStream iter(outer()->method());
2546 iter.reset_to_bci(tail->control());
2547
2548 bool is_an_if = false;
2549 bool wide = false;
2550 Bytecodes::Code bc = iter.next();
2551 switch (bc) {
2552 case Bytecodes::_ifeq:
2553 case Bytecodes::_ifne:
2554 case Bytecodes::_iflt:
2555 case Bytecodes::_ifge:
2556 case Bytecodes::_ifgt:
2557 case Bytecodes::_ifle:
2558 case Bytecodes::_if_icmpeq:
2559 case Bytecodes::_if_icmpne:
2560 case Bytecodes::_if_icmplt:
2561 case Bytecodes::_if_icmpge:
2562 case Bytecodes::_if_icmpgt:
2563 case Bytecodes::_if_icmple:
2564 case Bytecodes::_if_acmpeq:
2565 case Bytecodes::_if_acmpne:
2566 case Bytecodes::_ifnull:
2567 case Bytecodes::_ifnonnull:
2568 is_an_if = true;
2569 break;
2570 case Bytecodes::_goto_w:
2571 case Bytecodes::_jsr_w:
2572 wide = true;
2573 break;
2574 case Bytecodes::_goto:
2575 case Bytecodes::_jsr:
2576 break;
2577 default:
2578 fatal(" invalid bytecode: %s", Bytecodes::name(iter.cur_bc()));
2579 }
2580
2581 GrowableArray<ciTypeFlow::Block*>* succs = tail->successors();
2582
2583 if (!is_an_if) {
2584 assert(((wide ? iter.get_far_dest() : iter.get_dest()) == head()->start()) == (succs->at(ciTypeFlow::GOTO_TARGET) == head()), "branch should lead to loop head");
2585 if (succs->at(ciTypeFlow::GOTO_TARGET) == head()) {
2586 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2587 return _profiled_count;
2588 }
2589 } else {
2590 assert((iter.get_dest() == head()->start()) == (succs->at(ciTypeFlow::IF_TAKEN) == head()), "bytecode and CFG not consistent");
2591 assert((tail->limit() == head()->start()) == (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()), "bytecode and CFG not consistent");
2592 if (succs->at(ciTypeFlow::IF_TAKEN) == head()) {
2593 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2594 return _profiled_count;
2595 } else if (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()) {
2596 _profiled_count = outer()->method()->scale_count(data->as_BranchData()->not_taken());
2597 return _profiled_count;
2598 }
2599 }
2600
2601 _profiled_count = 0;
2602 return _profiled_count;
2603 }
2604
2605 bool ciTypeFlow::Loop::at_insertion_point(Loop* lp, Loop* current) {
2606 int lp_pre_order = lp->head()->pre_order();
2607 if (current->head()->pre_order() < lp_pre_order) {
2608 return true;
2609 } else if (current->head()->pre_order() > lp_pre_order) {
2610 return false;
2611 }
2612 // In the case of a shared head, make the most frequent head/tail (as reported by profiling) the inner loop
2613 if (current->head() == lp->head()) {
2614 int lp_count = lp->profiled_count();
2615 int current_count = current->profiled_count();
2616 if (current_count < lp_count) {
2617 return true;
2618 } else if (current_count > lp_count) {
2619 return false;
2620 }
2621 }
2622 if (current->tail()->pre_order() > lp->tail()->pre_order()) {
2623 return true;
2624 }
2625 return false;
2626 }
2627
2628 // ------------------------------------------------------------------
2629 // ciTypeFlow::Loop::sorted_merge
2630 //
2631 // Merge the branch lp into this branch, sorting on the loop head
2632 // pre_orders. Returns the leaf of the merged branch.
2633 // Child and sibling pointers will be setup later.
2634 // Sort is (looking from leaf towards the root)
2635 // descending on primary key: loop head's pre_order, and
2636 // ascending on secondary key: loop tail's pre_order.
2637 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2638 Loop* leaf = this;
2639 Loop* prev = nullptr;
2640 Loop* current = leaf;
2641 while (lp != nullptr) {
2642 int lp_pre_order = lp->head()->pre_order();
2643 // Find insertion point for "lp"
2644 while (current != nullptr) {
2645 if (current == lp) {
2646 return leaf; // Already in list
2647 }
2648 if (at_insertion_point(lp, current)) {
2649 break;
2650 }
2651 prev = current;
2652 current = current->parent();
2653 }
2654 Loop* next_lp = lp->parent(); // Save future list of items to insert
2655 // Insert lp before current
2656 lp->set_parent(current);
2657 if (prev != nullptr) {
2658 prev->set_parent(lp);
2659 } else {
2660 leaf = lp;
2661 }
2662 prev = lp; // Inserted item is new prev[ious]
2663 lp = next_lp; // Next item to insert
2664 }
2665 return leaf;
2666 }
2667
2668 // ------------------------------------------------------------------
2669 // ciTypeFlow::build_loop_tree
2670 //
2671 // Incrementally build loop tree.
2672 void ciTypeFlow::build_loop_tree(Block* blk) {
2673 assert(!blk->is_post_visited(), "precondition");
2674 Loop* innermost = nullptr; // merge of loop tree branches over all successors
2675
2676 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2677 Loop* lp = nullptr;
2678 Block* succ = iter.succ();
2679 if (!succ->is_post_visited()) {
2680 // Found backedge since predecessor post visited, but successor is not
2681 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2682
2683 // Create a LoopNode to mark this loop.
2684 lp = new (arena()) Loop(succ, blk);
2685 if (succ->loop() == nullptr)
2686 succ->set_loop(lp);
2687 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2688
2689 } else { // Nested loop
2690 lp = succ->loop();
2691
2692 // If succ is loop head, find outer loop.
2693 while (lp != nullptr && lp->head() == succ) {
2694 lp = lp->parent();
2695 }
2696 if (lp == nullptr) {
2697 // Infinite loop, it's parent is the root
2698 lp = loop_tree_root();
2699 }
2700 }
2701
2702 // Check for irreducible loop.
2703 // Successor has already been visited. If the successor's loop head
2704 // has already been post-visited, then this is another entry into the loop.
2705 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2706 _has_irreducible_entry = true;
2707 lp->set_irreducible(succ);
2708 if (!succ->is_on_work_list()) {
2709 // Assume irreducible entries need more data flow
2710 add_to_work_list(succ);
2711 }
2712 Loop* plp = lp->parent();
2713 if (plp == nullptr) {
2714 // This only happens for some irreducible cases. The parent
2715 // will be updated during a later pass.
2716 break;
2717 }
2718 lp = plp;
2719 }
2720
2721 // Merge loop tree branch for all successors.
2722 innermost = innermost == nullptr ? lp : innermost->sorted_merge(lp);
2723
2724 } // end loop
2725
2726 if (innermost == nullptr) {
2727 assert(blk->successors()->length() == 0, "CFG exit");
2728 blk->set_loop(loop_tree_root());
2729 } else if (innermost->head() == blk) {
2730 // If loop header, complete the tree pointers
2731 if (blk->loop() != innermost) {
2732 #ifdef ASSERT
2733 assert(blk->loop()->head() == innermost->head(), "same head");
2734 Loop* dl;
2735 for (dl = innermost; dl != nullptr && dl != blk->loop(); dl = dl->parent());
2736 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2737 #endif
2738 blk->set_loop(innermost);
2739 }
2740 innermost->def_locals()->add(blk->def_locals());
2741 Loop* l = innermost;
2742 Loop* p = l->parent();
2743 while (p && l->head() == blk) {
2744 l->set_sibling(p->child()); // Put self on parents 'next child'
2745 p->set_child(l); // Make self the first child of parent
2746 p->def_locals()->add(l->def_locals());
2747 l = p; // Walk up the parent chain
2748 p = l->parent();
2749 }
2750 } else {
2751 blk->set_loop(innermost);
2752 innermost->def_locals()->add(blk->def_locals());
2753 }
2754 }
2755
2756 // ------------------------------------------------------------------
2757 // ciTypeFlow::Loop::contains
2758 //
2759 // Returns true if lp is nested loop.
2760 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2761 assert(lp != nullptr, "");
2762 if (this == lp || head() == lp->head()) return true;
2763 int depth1 = depth();
2764 int depth2 = lp->depth();
2765 if (depth1 > depth2)
2766 return false;
2767 while (depth1 < depth2) {
2768 depth2--;
2769 lp = lp->parent();
2770 }
2771 return this == lp;
2772 }
2773
2774 // ------------------------------------------------------------------
2775 // ciTypeFlow::Loop::depth
2776 //
2777 // Loop depth
2778 int ciTypeFlow::Loop::depth() const {
2779 int dp = 0;
2780 for (Loop* lp = this->parent(); lp != nullptr; lp = lp->parent())
2781 dp++;
2782 return dp;
2783 }
2784
2785 #ifndef PRODUCT
2786 // ------------------------------------------------------------------
2787 // ciTypeFlow::Loop::print
2788 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2789 for (int i = 0; i < indent; i++) st->print(" ");
2790 st->print("%d<-%d %s",
2791 is_root() ? 0 : this->head()->pre_order(),
2792 is_root() ? 0 : this->tail()->pre_order(),
2793 is_irreducible()?" irr":"");
2794 st->print(" defs: ");
2795 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2796 st->cr();
2797 for (Loop* ch = child(); ch != nullptr; ch = ch->sibling())
2798 ch->print(st, indent+2);
2799 }
2800 #endif
2801
2802 // ------------------------------------------------------------------
2803 // ciTypeFlow::df_flow_types
2804 //
2805 // Perform the depth first type flow analysis. Helper for flow_types.
2806 void ciTypeFlow::df_flow_types(Block* start,
2807 bool do_flow,
2808 StateVector* temp_vector,
2809 JsrSet* temp_set) {
2810 int dft_len = 100;
2811 GrowableArray<Block*> stk(dft_len);
2812
2813 ciBlock* dummy = _method->get_method_blocks()->make_dummy_block();
2814 JsrSet* root_set = new JsrSet(0);
2815 Block* root_head = new (arena()) Block(this, dummy, root_set);
2816 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2817 root_head->set_pre_order(0);
2818 root_head->set_post_order(0);
2819 root_tail->set_pre_order(max_jint);
2820 root_tail->set_post_order(max_jint);
2821 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2822
2823 stk.push(start);
2824
2825 _next_pre_order = 0; // initialize pre_order counter
2826 _rpo_list = nullptr;
2827 int next_po = 0; // initialize post_order counter
2828
2829 // Compute RPO and the control flow graph
2830 int size;
2831 while ((size = stk.length()) > 0) {
2832 Block* blk = stk.top(); // Leave node on stack
2833 if (!blk->is_visited()) {
2834 // forward arc in graph
2835 assert (!blk->has_pre_order(), "");
2836 blk->set_next_pre_order();
2837
2838 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2839 // Too many basic blocks. Bail out.
2840 // This can happen when try/finally constructs are nested to depth N,
2841 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2842 // "MaxNodeLimit / 2" is used because probably the parser will
2843 // generate at least twice that many nodes and bail out.
2844 record_failure("too many basic blocks");
2845 return;
2846 }
2847 if (do_flow) {
2848 flow_block(blk, temp_vector, temp_set);
2849 if (failing()) return; // Watch for bailouts.
2850 }
2851 } else if (!blk->is_post_visited()) {
2852 // cross or back arc
2853 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2854 Block* succ = iter.succ();
2855 if (!succ->is_visited()) {
2856 stk.push(succ);
2857 }
2858 }
2859 if (stk.length() == size) {
2860 // There were no additional children, post visit node now
2861 stk.pop(); // Remove node from stack
2862
2863 build_loop_tree(blk);
2864 blk->set_post_order(next_po++); // Assign post order
2865 prepend_to_rpo_list(blk);
2866 assert(blk->is_post_visited(), "");
2867
2868 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2869 // Assume loop heads need more data flow
2870 add_to_work_list(blk);
2871 }
2872 }
2873 } else {
2874 stk.pop(); // Remove post-visited node from stack
2875 }
2876 }
2877 }
2878
2879 // ------------------------------------------------------------------
2880 // ciTypeFlow::flow_types
2881 //
2882 // Perform the type flow analysis, creating and cloning Blocks as
2883 // necessary.
2884 void ciTypeFlow::flow_types() {
2885 ResourceMark rm;
2886 StateVector* temp_vector = new StateVector(this);
2887 JsrSet* temp_set = new JsrSet(4);
2888
2889 // Create the method entry block.
2890 Block* start = block_at(start_bci(), temp_set);
2891
2892 // Load the initial state into it.
2893 const StateVector* start_state = get_start_state();
2894 if (failing()) return;
2895 start->meet(start_state);
2896
2897 // Depth first visit
2898 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2899
2900 if (failing()) return;
2901 assert(_rpo_list == start, "must be start");
2902
2903 // Any loops found?
2904 if (loop_tree_root()->child() != nullptr &&
2905 env()->comp_level() >= CompLevel_full_optimization) {
2906 // Loop optimizations are not performed on Tier1 compiles.
2907
2908 bool changed = clone_loop_heads(temp_vector, temp_set);
2909
2910 // If some loop heads were cloned, recompute postorder and loop tree
2911 if (changed) {
2912 loop_tree_root()->set_child(nullptr);
2913 for (Block* blk = _rpo_list; blk != nullptr;) {
2914 Block* next = blk->rpo_next();
2915 blk->df_init();
2916 blk = next;
2917 }
2918 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2919 }
2920 }
2921
2922 if (CITraceTypeFlow) {
2923 tty->print_cr("\nLoop tree");
2924 loop_tree_root()->print();
2925 }
2926
2927 // Continue flow analysis until fixed point reached
2928
2929 debug_only(int max_block = _next_pre_order;)
2930
2931 while (!work_list_empty()) {
2932 Block* blk = work_list_next();
2933 assert (blk->has_post_order(), "post order assigned above");
2934
2935 flow_block(blk, temp_vector, temp_set);
2936
2937 assert (max_block == _next_pre_order, "no new blocks");
2938 assert (!failing(), "no more bailouts");
2939 }
2940 }
2941
2942 // ------------------------------------------------------------------
2943 // ciTypeFlow::map_blocks
2944 //
2945 // Create the block map, which indexes blocks in reverse post-order.
2946 void ciTypeFlow::map_blocks() {
2947 assert(_block_map == nullptr, "single initialization");
2948 int block_ct = _next_pre_order;
2949 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2950 assert(block_ct == block_count(), "");
2951
2952 Block* blk = _rpo_list;
2953 for (int m = 0; m < block_ct; m++) {
2954 int rpo = blk->rpo();
2955 assert(rpo == m, "should be sequential");
2956 _block_map[rpo] = blk;
2957 blk = blk->rpo_next();
2958 }
2959 assert(blk == nullptr, "should be done");
2960
2961 for (int j = 0; j < block_ct; j++) {
2962 assert(_block_map[j] != nullptr, "must not drop any blocks");
2963 Block* block = _block_map[j];
2964 // Remove dead blocks from successor lists:
2965 for (int e = 0; e <= 1; e++) {
2966 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2967 for (int k = 0; k < l->length(); k++) {
2968 Block* s = l->at(k);
2969 if (!s->has_post_order()) {
2970 if (CITraceTypeFlow) {
2971 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2972 s->print_value_on(tty);
2973 tty->cr();
2974 }
2975 l->remove(s);
2976 --k;
2977 }
2978 }
2979 }
2980 }
2981 }
2982
2983 // ------------------------------------------------------------------
2984 // ciTypeFlow::get_block_for
2985 //
2986 // Find a block with this ciBlock which has a compatible JsrSet.
2987 // If no such block exists, create it, unless the option is no_create.
2988 // If the option is create_backedge_copy, always create a fresh backedge copy.
2989 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2990 Arena* a = arena();
2991 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2992 if (blocks == nullptr) {
2993 // Query only?
2994 if (option == no_create) return nullptr;
2995
2996 // Allocate the growable array.
2997 blocks = new (a) GrowableArray<Block*>(a, 4, 0, nullptr);
2998 _idx_to_blocklist[ciBlockIndex] = blocks;
2999 }
3000
3001 if (option != create_backedge_copy) {
3002 int len = blocks->length();
3003 for (int i = 0; i < len; i++) {
3004 Block* block = blocks->at(i);
3005 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3006 return block;
3007 }
3008 }
3009 }
3010
3011 // Query only?
3012 if (option == no_create) return nullptr;
3013
3014 // We did not find a compatible block. Create one.
3015 Block* new_block = new (a) Block(this, _method->get_method_blocks()->block(ciBlockIndex), jsrs);
3016 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
3017 blocks->append(new_block);
3018 return new_block;
3019 }
3020
3021 // ------------------------------------------------------------------
3022 // ciTypeFlow::backedge_copy_count
3023 //
3024 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
3025 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3026
3027 if (blocks == nullptr) {
3028 return 0;
3029 }
3030
3031 int count = 0;
3032 int len = blocks->length();
3033 for (int i = 0; i < len; i++) {
3034 Block* block = blocks->at(i);
3035 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3036 count++;
3037 }
3038 }
3039
3040 return count;
3041 }
3042
3043 // ------------------------------------------------------------------
3044 // ciTypeFlow::do_flow
3045 //
3046 // Perform type inference flow analysis.
3047 void ciTypeFlow::do_flow() {
3048 if (CITraceTypeFlow) {
3049 tty->print_cr("\nPerforming flow analysis on method");
3050 method()->print();
3051 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
3052 tty->cr();
3053 method()->print_codes();
3054 }
3055 if (CITraceTypeFlow) {
3056 tty->print_cr("Initial CI Blocks");
3057 print_on(tty);
3058 }
3059 flow_types();
3060 // Watch for bailouts.
3061 if (failing()) {
3062 return;
3063 }
3064
3065 map_blocks();
3066
3067 if (CIPrintTypeFlow || CITraceTypeFlow) {
3068 rpo_print_on(tty);
3069 }
3070 }
3071
3072 // ------------------------------------------------------------------
3073 // ciTypeFlow::is_dominated_by
3074 //
3075 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3076 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3077 assert(!method()->has_jsrs(), "jsrs are not supported");
3078
3079 ResourceMark rm;
3080 JsrSet* jsrs = new ciTypeFlow::JsrSet();
3081 int index = _method->get_method_blocks()->block_containing(bci)->index();
3082 int dom_index = _method->get_method_blocks()->block_containing(dom_bci)->index();
3083 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3084 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3085
3086 // Start block dominates all other blocks
3087 if (start_block()->rpo() == dom_block->rpo()) {
3088 return true;
3089 }
3090
3091 // Dominated[i] is true if block i is dominated by dom_block
3092 int num_blocks = block_count();
3093 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3094 for (int i = 0; i < num_blocks; ++i) {
3095 dominated[i] = true;
3096 }
3097 dominated[start_block()->rpo()] = false;
3098
3099 // Iterative dominator algorithm
3100 bool changed = true;
3101 while (changed) {
3102 changed = false;
3103 // Use reverse postorder iteration
3104 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3105 if (blk->is_start()) {
3106 // Ignore start block
3107 continue;
3108 }
3109 // The block is dominated if it is the dominating block
3110 // itself or if all predecessors are dominated.
3111 int index = blk->rpo();
3112 bool dom = (index == dom_block->rpo());
3113 if (!dom) {
3114 // Check if all predecessors are dominated
3115 dom = true;
3116 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3117 Block* pred = blk->predecessors()->at(i);
3118 if (!dominated[pred->rpo()]) {
3119 dom = false;
3120 break;
3121 }
3122 }
3123 }
3124 // Update dominator information
3125 if (dominated[index] != dom) {
3126 changed = true;
3127 dominated[index] = dom;
3128 }
3129 }
3130 }
3131 // block dominated by dom_block?
3132 return dominated[block->rpo()];
3133 }
3134
3135 // ------------------------------------------------------------------
3136 // ciTypeFlow::record_failure()
3137 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3138 // This is required because there is not a 1-1 relation between the ciEnv and
3139 // the TypeFlow passes within a compilation task. For example, if the compiler
3140 // is considering inlining a method, it will request a TypeFlow. If that fails,
3141 // the compilation as a whole may continue without the inlining. Some TypeFlow
3142 // requests are not optional; if they fail the requestor is responsible for
3143 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3144 void ciTypeFlow::record_failure(const char* reason) {
3145 if (env()->log() != nullptr) {
3146 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3147 }
3148 if (_failure_reason == nullptr) {
3149 // Record the first failure reason.
3150 _failure_reason = reason;
3151 }
3152 }
3153
3154 #ifndef PRODUCT
3155 void ciTypeFlow::print() const { print_on(tty); }
3156
3157 // ------------------------------------------------------------------
3158 // ciTypeFlow::print_on
3159 void ciTypeFlow::print_on(outputStream* st) const {
3160 // Walk through CI blocks
3161 st->print_cr("********************************************************");
3162 st->print ("TypeFlow for ");
3163 method()->name()->print_symbol_on(st);
3164 int limit_bci = code_size();
3165 st->print_cr(" %d bytes", limit_bci);
3166 ciMethodBlocks* mblks = _method->get_method_blocks();
3167 ciBlock* current = nullptr;
3168 for (int bci = 0; bci < limit_bci; bci++) {
3169 ciBlock* blk = mblks->block_containing(bci);
3170 if (blk != nullptr && blk != current) {
3171 current = blk;
3172 current->print_on(st);
3173
3174 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3175 int num_blocks = (blocks == nullptr) ? 0 : blocks->length();
3176
3177 if (num_blocks == 0) {
3178 st->print_cr(" No Blocks");
3179 } else {
3180 for (int i = 0; i < num_blocks; i++) {
3181 Block* block = blocks->at(i);
3182 block->print_on(st);
3183 }
3184 }
3185 st->print_cr("--------------------------------------------------------");
3186 st->cr();
3187 }
3188 }
3189 st->print_cr("********************************************************");
3190 st->cr();
3191 }
3192
3193 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3194 st->print_cr("********************************************************");
3195 st->print ("TypeFlow for ");
3196 method()->name()->print_symbol_on(st);
3197 int limit_bci = code_size();
3198 st->print_cr(" %d bytes", limit_bci);
3199 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3200 blk->print_on(st);
3201 st->print_cr("--------------------------------------------------------");
3202 st->cr();
3203 }
3204 st->print_cr("********************************************************");
3205 st->cr();
3206 }
3207 #endif