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