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