1 /*
2 * Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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.
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23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciInlineKlass.hpp"
29 #include "ci/ciMethod.hpp"
30 #include "ci/ciMethodData.hpp"
31 #include "ci/ciObjArrayKlass.hpp"
32 #include "ci/ciStreams.hpp"
33 #include "ci/ciTypeArrayKlass.hpp"
34 #include "ci/ciTypeFlow.hpp"
35 #include "compiler/compileLog.hpp"
36 #include "interpreter/bytecode.hpp"
37 #include "interpreter/bytecodes.hpp"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "opto/compile.hpp"
42 #include "opto/node.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "utilities/growableArray.hpp"
45
46 // ciTypeFlow::JsrSet
47 //
48 // A JsrSet represents some set of JsrRecords. This class
49 // is used to record a set of all jsr routines which we permit
50 // execution to return (ret) from.
51 //
52 // During abstract interpretation, JsrSets are used to determine
53 // whether two paths which reach a given block are unique, and
54 // should be cloned apart, or are compatible, and should merge
55 // together.
56
57 // ------------------------------------------------------------------
58 // ciTypeFlow::JsrSet::JsrSet
59
60 // Allocate growable array storage in Arena.
61 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) : _set(arena, default_len, 0, nullptr) {
62 assert(arena != nullptr, "invariant");
63 }
64
65 // Allocate growable array storage in current ResourceArea.
66 ciTypeFlow::JsrSet::JsrSet(int default_len) : _set(default_len, 0, nullptr) {}
67
68 // ------------------------------------------------------------------
69 // ciTypeFlow::JsrSet::copy_into
70 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
71 int len = size();
72 jsrs->_set.clear();
73 for (int i = 0; i < len; i++) {
74 jsrs->_set.append(_set.at(i));
75 }
76 }
77
78 // ------------------------------------------------------------------
79 // ciTypeFlow::JsrSet::is_compatible_with
80 //
81 // !!!! MISGIVINGS ABOUT THIS... disregard
82 //
83 // Is this JsrSet compatible with some other JsrSet?
84 //
85 // In set-theoretic terms, a JsrSet can be viewed as a partial function
86 // from entry addresses to return addresses. Two JsrSets A and B are
87 // compatible iff
88 //
89 // For any x,
90 // A(x) defined and B(x) defined implies A(x) == B(x)
91 //
92 // Less formally, two JsrSets are compatible when they have identical
93 // return addresses for any entry addresses they share in common.
94 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
95 // Walk through both sets in parallel. If the same entry address
96 // appears in both sets, then the return address must match for
97 // the sets to be compatible.
98 int size1 = size();
99 int size2 = other->size();
100
101 // Special case. If nothing is on the jsr stack, then there can
102 // be no ret.
103 if (size2 == 0) {
104 return true;
105 } else if (size1 != size2) {
106 return false;
107 } else {
108 for (int i = 0; i < size1; i++) {
109 JsrRecord* record1 = record_at(i);
110 JsrRecord* record2 = other->record_at(i);
111 if (record1->entry_address() != record2->entry_address() ||
112 record1->return_address() != record2->return_address()) {
113 return false;
114 }
115 }
116 return true;
117 }
118
119 #if 0
120 int pos1 = 0;
121 int pos2 = 0;
122 int size1 = size();
123 int size2 = other->size();
124 while (pos1 < size1 && pos2 < size2) {
125 JsrRecord* record1 = record_at(pos1);
126 JsrRecord* record2 = other->record_at(pos2);
127 int entry1 = record1->entry_address();
128 int entry2 = record2->entry_address();
129 if (entry1 < entry2) {
130 pos1++;
131 } else if (entry1 > entry2) {
132 pos2++;
133 } else {
134 if (record1->return_address() == record2->return_address()) {
135 pos1++;
136 pos2++;
137 } else {
138 // These two JsrSets are incompatible.
139 return false;
140 }
141 }
142 }
143 // The two JsrSets agree.
144 return true;
145 #endif
146 }
147
148 // ------------------------------------------------------------------
149 // ciTypeFlow::JsrSet::insert_jsr_record
150 //
151 // Insert the given JsrRecord into the JsrSet, maintaining the order
152 // of the set and replacing any element with the same entry address.
153 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
154 int len = size();
155 int entry = record->entry_address();
156 int pos = 0;
157 for ( ; pos < len; pos++) {
158 JsrRecord* current = record_at(pos);
159 if (entry == current->entry_address()) {
160 // Stomp over this entry.
161 _set.at_put(pos, record);
162 assert(size() == len, "must be same size");
163 return;
164 } else if (entry < current->entry_address()) {
165 break;
166 }
167 }
168
169 // Insert the record into the list.
170 JsrRecord* swap = record;
171 JsrRecord* temp = nullptr;
172 for ( ; pos < len; pos++) {
173 temp = _set.at(pos);
174 _set.at_put(pos, swap);
175 swap = temp;
176 }
177 _set.append(swap);
178 assert(size() == len+1, "must be larger");
179 }
180
181 // ------------------------------------------------------------------
182 // ciTypeFlow::JsrSet::remove_jsr_record
183 //
184 // Remove the JsrRecord with the given return address from the JsrSet.
185 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
186 int len = size();
187 for (int i = 0; i < len; i++) {
188 if (record_at(i)->return_address() == return_address) {
189 // We have found the proper entry. Remove it from the
190 // JsrSet and exit.
191 for (int j = i + 1; j < len ; j++) {
192 _set.at_put(j - 1, _set.at(j));
193 }
194 _set.trunc_to(len - 1);
195 assert(size() == len-1, "must be smaller");
196 return;
197 }
198 }
199 assert(false, "verify: returning from invalid subroutine");
200 }
201
202 // ------------------------------------------------------------------
203 // ciTypeFlow::JsrSet::apply_control
204 //
205 // Apply the effect of a control-flow bytecode on the JsrSet. The
206 // only bytecodes that modify the JsrSet are jsr and ret.
207 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
208 ciBytecodeStream* str,
209 ciTypeFlow::StateVector* state) {
210 Bytecodes::Code code = str->cur_bc();
211 if (code == Bytecodes::_jsr) {
212 JsrRecord* record =
213 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
214 insert_jsr_record(record);
215 } else if (code == Bytecodes::_jsr_w) {
216 JsrRecord* record =
217 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
218 insert_jsr_record(record);
219 } else if (code == Bytecodes::_ret) {
220 Cell local = state->local(str->get_index());
221 ciType* return_address = state->type_at(local);
222 assert(return_address->is_return_address(), "verify: wrong type");
223 if (size() == 0) {
224 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
225 // This can happen when a loop is inside a finally clause (4614060).
226 analyzer->record_failure("OSR in finally clause");
227 return;
228 }
229 remove_jsr_record(return_address->as_return_address()->bci());
230 }
231 }
232
233 #ifndef PRODUCT
234 // ------------------------------------------------------------------
235 // ciTypeFlow::JsrSet::print_on
236 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
237 st->print("{ ");
238 int num_elements = size();
239 if (num_elements > 0) {
240 int i = 0;
241 for( ; i < num_elements - 1; i++) {
242 _set.at(i)->print_on(st);
243 st->print(", ");
244 }
245 _set.at(i)->print_on(st);
246 st->print(" ");
247 }
248 st->print("}");
249 }
250 #endif
251
252 // ciTypeFlow::StateVector
253 //
254 // A StateVector summarizes the type information at some point in
255 // the program.
256
257 // ------------------------------------------------------------------
258 // ciTypeFlow::StateVector::type_meet
259 //
260 // Meet two types.
261 //
262 // The semi-lattice of types use by this analysis are modeled on those
263 // of the verifier. The lattice is as follows:
264 //
265 // top_type() >= all non-extremal types >= bottom_type
266 // and
267 // Every primitive type is comparable only with itself. The meet of
268 // reference types is determined by their kind: instance class,
269 // interface, or array class. The meet of two types of the same
270 // kind is their least common ancestor. The meet of two types of
271 // different kinds is always java.lang.Object.
272 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
273 assert(t1 != t2, "checked in caller");
274 if (t1->equals(top_type())) {
275 return t2;
276 } else if (t2->equals(top_type())) {
277 return t1;
278 }
279 // Unwrap after saving nullness information and handling top meets
280 bool null_free1 = t1->is_null_free();
281 bool null_free2 = t2->is_null_free();
282 if (t1->unwrap() == t2->unwrap() && null_free1 == null_free2) {
283 return t1;
284 }
285 t1 = t1->unwrap();
286 t2 = t2->unwrap();
287
288 if (t1->is_primitive_type() || t2->is_primitive_type()) {
289 // Special case null_type. null_type meet any reference type T
290 // is T. null_type meet null_type is null_type.
291 if (t1->equals(null_type())) {
292 if (!t2->is_primitive_type() || t2->equals(null_type())) {
293 return t2;
294 }
295 } else if (t2->equals(null_type())) {
296 if (!t1->is_primitive_type()) {
297 return t1;
298 }
299 }
300
301 // At least one of the two types is a non-top primitive type.
302 // The other type is not equal to it. Fall to bottom.
303 return bottom_type();
304 }
305
306 // Both types are non-top non-primitive types. That is,
307 // both types are either instanceKlasses or arrayKlasses.
308 ciKlass* object_klass = analyzer->env()->Object_klass();
309 ciKlass* k1 = t1->as_klass();
310 ciKlass* k2 = t2->as_klass();
311 if (k1->equals(object_klass) || k2->equals(object_klass)) {
312 return object_klass;
313 } else if (!k1->is_loaded() || !k2->is_loaded()) {
314 // Unloaded classes fall to java.lang.Object at a merge.
315 return object_klass;
316 } else if (k1->is_interface() != k2->is_interface()) {
317 // When an interface meets a non-interface, we get Object;
318 // This is what the verifier does.
319 return object_klass;
320 } else if (k1->is_array_klass() || k2->is_array_klass()) {
321 // When an array meets a non-array, we get Object.
322 // When (obj/flat)Array meets typeArray, we also get Object.
323 // And when typeArray meets different typeArray, we again get Object.
324 // But when (obj/flat)Array meets (obj/flat)Array, we look carefully at element types.
325 if ((k1->is_obj_array_klass() || k1->is_flat_array_klass()) &&
326 (k2->is_obj_array_klass() || k2->is_flat_array_klass())) {
327 bool null_free = k1->as_array_klass()->is_elem_null_free() &&
328 k2->as_array_klass()->is_elem_null_free();
329 ciType* elem1 = k1->as_array_klass()->element_klass();
330 ciType* elem2 = k2->as_array_klass()->element_klass();
331 ciType* elem = elem1;
332 if (elem1 != elem2) {
333 elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
334 }
335 // Do an easy shortcut if one type is a super of the other.
336 if (elem == elem1 && !elem->is_inlinetype()) {
337 assert(k1 == ciArrayKlass::make(elem, null_free), "shortcut is OK");
338 return k1;
339 } else if (elem == elem2 && !elem->is_inlinetype()) {
340 assert(k2 == ciArrayKlass::make(elem, null_free), "shortcut is OK");
341 return k2;
342 } else {
343 // TODO 8325106 Remove
344 assert(!null_free, "should be dead");
345 return ciArrayKlass::make(elem);
346 }
347 } else {
348 return object_klass;
349 }
350 } else {
351 // Must be two plain old instance klasses.
352 assert(k1->is_instance_klass(), "previous cases handle non-instances");
353 assert(k2->is_instance_klass(), "previous cases handle non-instances");
354 ciType* result = k1->least_common_ancestor(k2);
355 if (null_free1 && null_free2 && result->is_inlinetype()) {
356 result = analyzer->mark_as_null_free(result);
357 }
358 return result;
359 }
360 }
361
362
363 // ------------------------------------------------------------------
364 // ciTypeFlow::StateVector::StateVector
365 //
366 // Build a new state vector
367 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
368 _outer = analyzer;
369 _stack_size = -1;
370 _monitor_count = -1;
371 // Allocate the _types array
372 int max_cells = analyzer->max_cells();
373 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
374 for (int i=0; i<max_cells; i++) {
375 _types[i] = top_type();
376 }
377 _trap_bci = -1;
378 _trap_index = 0;
379 _def_locals.clear();
380 }
381
382
383 // ------------------------------------------------------------------
384 // ciTypeFlow::get_start_state
385 //
386 // Set this vector to the method entry state.
387 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
388 StateVector* state = new StateVector(this);
389 if (is_osr_flow()) {
390 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
391 if (non_osr_flow->failing()) {
392 record_failure(non_osr_flow->failure_reason());
393 return nullptr;
394 }
395 JsrSet* jsrs = new JsrSet(4);
396 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
397 if (non_osr_block == nullptr) {
398 record_failure("cannot reach OSR point");
399 return nullptr;
400 }
401 // load up the non-OSR state at this point
402 non_osr_block->copy_state_into(state);
403 int non_osr_start = non_osr_block->start();
404 if (non_osr_start != start_bci()) {
405 // must flow forward from it
406 if (CITraceTypeFlow) {
407 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
408 }
409 Block* block = block_at(non_osr_start, jsrs);
410 assert(block->limit() == start_bci(), "must flow forward to start");
411 flow_block(block, state, jsrs);
412 }
413 return state;
414 // Note: The code below would be an incorrect for an OSR flow,
415 // even if it were possible for an OSR entry point to be at bci zero.
416 }
417 // "Push" the method signature into the first few locals.
418 state->set_stack_size(-max_locals());
419 if (!method()->is_static()) {
420 ciType* holder = method()->holder();
421 if (holder->is_inlinetype()) {
422 // The receiver is null-free
423 holder = mark_as_null_free(holder);
424 }
425 state->push(holder);
426 assert(state->tos() == state->local(0), "");
427 }
428 for (ciSignatureStream str(method()->signature());
429 !str.at_return_type();
430 str.next()) {
431 state->push_translate(str.type());
432 }
433 // Set the rest of the locals to bottom.
434 Cell cell = state->next_cell(state->tos());
435 state->set_stack_size(0);
436 int limit = state->limit_cell();
437 for (; cell < limit; cell = state->next_cell(cell)) {
438 state->set_type_at(cell, state->bottom_type());
439 }
440 // Lock an object, if necessary.
441 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
442 return state;
443 }
444
445 // ------------------------------------------------------------------
446 // ciTypeFlow::StateVector::copy_into
447 //
448 // Copy our value into some other StateVector
449 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
450 const {
451 copy->set_stack_size(stack_size());
452 copy->set_monitor_count(monitor_count());
453 Cell limit = limit_cell();
454 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
455 copy->set_type_at(c, type_at(c));
456 }
457 }
458
459 // ------------------------------------------------------------------
460 // ciTypeFlow::StateVector::meet
461 //
462 // Meets this StateVector with another, destructively modifying this
463 // one. Returns true if any modification takes place.
464 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
465 if (monitor_count() == -1) {
466 set_monitor_count(incoming->monitor_count());
467 }
468 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
469
470 if (stack_size() == -1) {
471 set_stack_size(incoming->stack_size());
472 Cell limit = limit_cell();
473 #ifdef ASSERT
474 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
475 assert(type_at(c) == top_type(), "");
476 } }
477 #endif
478 // Make a simple copy of the incoming state.
479 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
480 set_type_at(c, incoming->type_at(c));
481 }
482 return true; // it is always different the first time
483 }
484 #ifdef ASSERT
485 if (stack_size() != incoming->stack_size()) {
486 _outer->method()->print_codes();
487 tty->print_cr("!!!! Stack size conflict");
488 tty->print_cr("Current state:");
489 print_on(tty);
490 tty->print_cr("Incoming state:");
491 ((StateVector*)incoming)->print_on(tty);
492 }
493 #endif
494 assert(stack_size() == incoming->stack_size(), "sanity");
495
496 bool different = false;
497 Cell limit = limit_cell();
498 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
499 ciType* t1 = type_at(c);
500 ciType* t2 = incoming->type_at(c);
501 if (!t1->equals(t2)) {
502 ciType* new_type = type_meet(t1, t2);
503 if (!t1->equals(new_type)) {
504 set_type_at(c, new_type);
505 different = true;
506 }
507 }
508 }
509 return different;
510 }
511
512 // ------------------------------------------------------------------
513 // ciTypeFlow::StateVector::meet_exception
514 //
515 // Meets this StateVector with another, destructively modifying this
516 // one. The incoming state is coming via an exception. Returns true
517 // if any modification takes place.
518 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
519 const ciTypeFlow::StateVector* incoming) {
520 if (monitor_count() == -1) {
521 set_monitor_count(incoming->monitor_count());
522 }
523 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
524
525 if (stack_size() == -1) {
526 set_stack_size(1);
527 }
528
529 assert(stack_size() == 1, "must have one-element stack");
530
531 bool different = false;
532
533 // Meet locals from incoming array.
534 Cell limit = local(_outer->max_locals()-1);
535 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
536 ciType* t1 = type_at(c);
537 ciType* t2 = incoming->type_at(c);
538 if (!t1->equals(t2)) {
539 ciType* new_type = type_meet(t1, t2);
540 if (!t1->equals(new_type)) {
541 set_type_at(c, new_type);
542 different = true;
543 }
544 }
545 }
546
547 // Handle stack separately. When an exception occurs, the
548 // only stack entry is the exception instance.
549 ciType* tos_type = type_at_tos();
550 if (!tos_type->equals(exc)) {
551 ciType* new_type = type_meet(tos_type, exc);
552 if (!tos_type->equals(new_type)) {
553 set_type_at_tos(new_type);
554 different = true;
555 }
556 }
557
558 return different;
559 }
560
561 // ------------------------------------------------------------------
562 // ciTypeFlow::StateVector::push_translate
563 void ciTypeFlow::StateVector::push_translate(ciType* type) {
564 BasicType basic_type = type->basic_type();
565 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
566 basic_type == T_BYTE || basic_type == T_SHORT) {
567 push_int();
568 } else {
569 push(type);
570 if (type->is_two_word()) {
571 push(half_type(type));
572 }
573 }
574 }
575
576 // ------------------------------------------------------------------
577 // ciTypeFlow::StateVector::do_aload
578 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
579 pop_int();
580 ciArrayKlass* array_klass = pop_objOrFlatArray();
581 if (array_klass == nullptr) {
582 // Did aload on a null reference; push a null and ignore the exception.
583 // This instruction will never continue normally. All we have to do
584 // is report a value that will meet correctly with any downstream
585 // reference types on paths that will truly be executed. This null type
586 // meets with any reference type to yield that same reference type.
587 // (The compiler will generate an unconditional exception here.)
588 push(null_type());
589 return;
590 }
591 if (!array_klass->is_loaded()) {
592 // Only fails for some -Xcomp runs
593 trap(str, array_klass,
594 Deoptimization::make_trap_request
595 (Deoptimization::Reason_unloaded,
596 Deoptimization::Action_reinterpret));
597 return;
598 }
599 ciKlass* element_klass = array_klass->element_klass();
600 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
601 Untested("unloaded array element class in ciTypeFlow");
602 trap(str, element_klass,
603 Deoptimization::make_trap_request
604 (Deoptimization::Reason_unloaded,
605 Deoptimization::Action_reinterpret));
606 } else {
607 if (array_klass->is_elem_null_free()) {
608 // TODO 8325106 Is this dead?
609 push(outer()->mark_as_null_free(element_klass));
610 } else {
611 push_object(element_klass);
612 }
613 }
614 }
615
616
617 // ------------------------------------------------------------------
618 // ciTypeFlow::StateVector::do_checkcast
619 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
620 bool will_link;
621 ciKlass* klass = str->get_klass(will_link);
622 if (!will_link) {
623 // VM's interpreter will not load 'klass' if object is nullptr.
624 // Type flow after this block may still be needed in two situations:
625 // 1) C2 uses do_null_assert() and continues compilation for later blocks
626 // 2) C2 does an OSR compile in a later block (see bug 4778368).
627 pop_object();
628 do_null_assert(klass);
629 } else {
630 ciType* type = pop_value();
631 type = type->unwrap();
632 if (type->is_loaded() && klass->is_loaded() &&
633 type != klass && type->is_subtype_of(klass)) {
634 // Useless cast, propagate more precise type of object
635 klass = type->as_klass();
636 }
637 if (klass->is_inlinetype() && type->is_null_free()) {
638 // TODO 8325106 Is this dead?
639 push(outer()->mark_as_null_free(klass));
640 } else {
641 push_object(klass);
642 }
643 }
644 }
645
646 // ------------------------------------------------------------------
647 // ciTypeFlow::StateVector::do_getfield
648 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
649 // could add assert here for type of object.
650 pop_object();
651 do_getstatic(str);
652 }
653
654 // ------------------------------------------------------------------
655 // ciTypeFlow::StateVector::do_getstatic
656 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
657 bool will_link;
658 ciField* field = str->get_field(will_link);
659 if (!will_link) {
660 trap(str, field->holder(), str->get_field_holder_index());
661 } else {
662 ciType* field_type = field->type();
663 if (field->is_static() && field->is_null_free() &&
664 !field_type->as_instance_klass()->is_initialized()) {
665 // Deoptimize if we load from a static field with an uninitialized inline type
666 // because we need to throw an exception if initialization of the type failed.
667 trap(str, field_type->as_klass(),
668 Deoptimization::make_trap_request
669 (Deoptimization::Reason_unloaded,
670 Deoptimization::Action_reinterpret));
671 return;
672 } else if (!field_type->is_loaded()) {
673 // Normally, we need the field's type to be loaded if we are to
674 // do anything interesting with its value.
675 // We used to do this: trap(str, str->get_field_signature_index());
676 //
677 // There is one good reason not to trap here. Execution can
678 // get past this "getfield" or "getstatic" if the value of
679 // the field is null. As long as the value is null, the class
680 // does not need to be loaded! The compiler must assume that
681 // the value of the unloaded class reference is null; if the code
682 // ever sees a non-null value, loading has occurred.
683 //
684 // This actually happens often enough to be annoying. If the
685 // compiler throws an uncommon trap at this bytecode, you can
686 // get an endless loop of recompilations, when all the code
687 // needs to do is load a series of null values. Also, a trap
688 // here can make an OSR entry point unreachable, triggering the
689 // assert on non_osr_block in ciTypeFlow::get_start_state.
690 // (See bug 4379915.)
691 do_null_assert(field_type->as_klass());
692 } else {
693 if (field->is_null_free()) {
694 field_type = outer()->mark_as_null_free(field_type);
695 }
696 push_translate(field_type);
697 }
698 }
699 }
700
701 // ------------------------------------------------------------------
702 // ciTypeFlow::StateVector::do_invoke
703 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
704 bool has_receiver) {
705 bool will_link;
706 ciSignature* declared_signature = nullptr;
707 ciMethod* callee = str->get_method(will_link, &declared_signature);
708 assert(declared_signature != nullptr, "cannot be null");
709 if (!will_link) {
710 // We weren't able to find the method.
711 if (str->cur_bc() == Bytecodes::_invokedynamic) {
712 trap(str, nullptr,
713 Deoptimization::make_trap_request
714 (Deoptimization::Reason_uninitialized,
715 Deoptimization::Action_reinterpret));
716 } else {
717 ciKlass* unloaded_holder = callee->holder();
718 trap(str, unloaded_holder, str->get_method_holder_index());
719 }
720 } else {
721 // We are using the declared signature here because it might be
722 // different from the callee signature (Cf. invokedynamic and
723 // invokehandle).
724 ciSignatureStream sigstr(declared_signature);
725 const int arg_size = declared_signature->size();
726 const int stack_base = stack_size() - arg_size;
727 int i = 0;
728 for( ; !sigstr.at_return_type(); sigstr.next()) {
729 ciType* type = sigstr.type();
730 ciType* stack_type = type_at(stack(stack_base + i++));
731 // Do I want to check this type?
732 // assert(stack_type->is_subtype_of(type), "bad type for field value");
733 if (type->is_two_word()) {
734 ciType* stack_type2 = type_at(stack(stack_base + i++));
735 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
736 }
737 }
738 assert(arg_size == i, "must match");
739 for (int j = 0; j < arg_size; j++) {
740 pop();
741 }
742 if (has_receiver) {
743 // Check this?
744 pop_object();
745 }
746 assert(!sigstr.is_done(), "must have return type");
747 ciType* return_type = sigstr.type();
748 if (!return_type->is_void()) {
749 if (!return_type->is_loaded()) {
750 // As in do_getstatic(), generally speaking, we need the return type to
751 // be loaded if we are to do anything interesting with its value.
752 // We used to do this: trap(str, str->get_method_signature_index());
753 //
754 // We do not trap here since execution can get past this invoke if
755 // the return value is null. As long as the value is null, the class
756 // does not need to be loaded! The compiler must assume that
757 // the value of the unloaded class reference is null; if the code
758 // ever sees a non-null value, loading has occurred.
759 //
760 // See do_getstatic() for similar explanation, as well as bug 4684993.
761 if (InlineTypeReturnedAsFields) {
762 // Return might be in scalarized form but we can't handle it because we
763 // don't know the type. This can happen due to a missing preload attribute.
764 // TODO 8284443 Use PhaseMacroExpand::expand_mh_intrinsic_return for this
765 trap(str, nullptr,
766 Deoptimization::make_trap_request
767 (Deoptimization::Reason_uninitialized,
768 Deoptimization::Action_reinterpret));
769 } else {
770 do_null_assert(return_type->as_klass());
771 }
772 } else {
773 push_translate(return_type);
774 }
775 }
776 }
777 }
778
779 // ------------------------------------------------------------------
780 // ciTypeFlow::StateVector::do_jsr
781 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
782 push(ciReturnAddress::make(str->next_bci()));
783 }
784
785 // ------------------------------------------------------------------
786 // ciTypeFlow::StateVector::do_ldc
787 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
788 if (str->is_in_error()) {
789 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unhandled,
790 Deoptimization::Action_none));
791 return;
792 }
793 ciConstant con = str->get_constant();
794 if (con.is_valid()) {
795 int cp_index = str->get_constant_pool_index();
796 BasicType basic_type = str->get_basic_type_for_constant_at(cp_index);
797 if (is_reference_type(basic_type)) {
798 ciObject* obj = con.as_object();
799 if (obj->is_null_object()) {
800 push_null();
801 } else {
802 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
803 ciType* type = obj->klass();
804 if (type->is_inlinetype()) {
805 type = outer()->mark_as_null_free(type);
806 }
807 push(type);
808 }
809 } else {
810 assert(basic_type == con.basic_type() || con.basic_type() == T_OBJECT,
811 "not a boxed form: %s vs %s", type2name(basic_type), type2name(con.basic_type()));
812 push_translate(ciType::make(basic_type));
813 }
814 } else {
815 // OutOfMemoryError in the CI while loading a String constant.
816 push_null();
817 outer()->record_failure("ldc did not link");
818 }
819 }
820
821 // ------------------------------------------------------------------
822 // ciTypeFlow::StateVector::do_multianewarray
823 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
824 int dimensions = str->get_dimensions();
825 bool will_link;
826 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
827 if (!will_link) {
828 trap(str, array_klass, str->get_klass_index());
829 } else {
830 for (int i = 0; i < dimensions; i++) {
831 pop_int();
832 }
833 push_object(array_klass);
834 }
835 }
836
837 // ------------------------------------------------------------------
838 // ciTypeFlow::StateVector::do_new
839 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
840 bool will_link;
841 ciKlass* klass = str->get_klass(will_link);
842 if (!will_link || str->is_unresolved_klass()) {
843 trap(str, klass, str->get_klass_index());
844 } else {
845 push_object(klass);
846 }
847 }
848
849 // ------------------------------------------------------------------
850 // ciTypeFlow::StateVector::do_newarray
851 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
852 pop_int();
853 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
854 push_object(klass);
855 }
856
857 // ------------------------------------------------------------------
858 // ciTypeFlow::StateVector::do_putfield
859 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
860 do_putstatic(str);
861 if (_trap_bci != -1) return; // unloaded field holder, etc.
862 // could add assert here for type of object.
863 pop_object();
864 }
865
866 // ------------------------------------------------------------------
867 // ciTypeFlow::StateVector::do_putstatic
868 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
869 bool will_link;
870 ciField* field = str->get_field(will_link);
871 if (!will_link) {
872 trap(str, field->holder(), str->get_field_holder_index());
873 } else {
874 ciType* field_type = field->type();
875 ciType* type = pop_value();
876 // Do I want to check this type?
877 // assert(type->is_subtype_of(field_type), "bad type for field value");
878 if (field_type->is_two_word()) {
879 ciType* type2 = pop_value();
880 assert(type2->is_two_word(), "must be 2nd half");
881 assert(type == half_type(type2), "must be 2nd half");
882 }
883 }
884 }
885
886 // ------------------------------------------------------------------
887 // ciTypeFlow::StateVector::do_ret
888 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
889 Cell index = local(str->get_index());
890
891 ciType* address = type_at(index);
892 assert(address->is_return_address(), "bad return address");
893 set_type_at(index, bottom_type());
894 }
895
896 // ------------------------------------------------------------------
897 // ciTypeFlow::StateVector::trap
898 //
899 // Stop interpretation of this path with a trap.
900 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
901 _trap_bci = str->cur_bci();
902 _trap_index = index;
903
904 // Log information about this trap:
905 CompileLog* log = outer()->env()->log();
906 if (log != nullptr) {
907 int mid = log->identify(outer()->method());
908 int kid = (klass == nullptr)? -1: log->identify(klass);
909 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
910 char buf[100];
911 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
912 index));
913 if (kid >= 0)
914 log->print(" klass='%d'", kid);
915 log->end_elem();
916 }
917 }
918
919 // ------------------------------------------------------------------
920 // ciTypeFlow::StateVector::do_null_assert
921 // Corresponds to graphKit::do_null_assert.
922 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
923 if (unloaded_klass->is_loaded()) {
924 // We failed to link, but we can still compute with this class,
925 // since it is loaded somewhere. The compiler will uncommon_trap
926 // if the object is not null, but the typeflow pass can not assume
927 // that the object will be null, otherwise it may incorrectly tell
928 // the parser that an object is known to be null. 4761344, 4807707
929 push_object(unloaded_klass);
930 } else {
931 // The class is not loaded anywhere. It is safe to model the
932 // null in the typestates, because we can compile in a null check
933 // which will deoptimize us if someone manages to load the
934 // class later.
935 push_null();
936 }
937 }
938
939
940 // ------------------------------------------------------------------
941 // ciTypeFlow::StateVector::apply_one_bytecode
942 //
943 // Apply the effect of one bytecode to this StateVector
944 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
945 _trap_bci = -1;
946 _trap_index = 0;
947
948 if (CITraceTypeFlow) {
949 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
950 Bytecodes::name(str->cur_bc()));
951 }
952
953 switch(str->cur_bc()) {
954 case Bytecodes::_aaload: do_aload(str); break;
955
956 case Bytecodes::_aastore:
957 {
958 pop_object();
959 pop_int();
960 pop_objOrFlatArray();
961 break;
962 }
963 case Bytecodes::_aconst_null:
964 {
965 push_null();
966 break;
967 }
968 case Bytecodes::_aload: load_local_object(str->get_index()); break;
969 case Bytecodes::_aload_0: load_local_object(0); break;
970 case Bytecodes::_aload_1: load_local_object(1); break;
971 case Bytecodes::_aload_2: load_local_object(2); break;
972 case Bytecodes::_aload_3: load_local_object(3); break;
973
974 case Bytecodes::_anewarray:
975 {
976 pop_int();
977 bool will_link;
978 ciKlass* element_klass = str->get_klass(will_link);
979 if (!will_link) {
980 trap(str, element_klass, str->get_klass_index());
981 } else {
982 push_object(ciArrayKlass::make(element_klass));
983 }
984 break;
985 }
986 case Bytecodes::_areturn:
987 case Bytecodes::_ifnonnull:
988 case Bytecodes::_ifnull:
989 {
990 pop_object();
991 break;
992 }
993 case Bytecodes::_monitorenter:
994 {
995 pop_object();
996 set_monitor_count(monitor_count() + 1);
997 break;
998 }
999 case Bytecodes::_monitorexit:
1000 {
1001 pop_object();
1002 assert(monitor_count() > 0, "must be a monitor to exit from");
1003 set_monitor_count(monitor_count() - 1);
1004 break;
1005 }
1006 case Bytecodes::_arraylength:
1007 {
1008 pop_array();
1009 push_int();
1010 break;
1011 }
1012 case Bytecodes::_astore: store_local_object(str->get_index()); break;
1013 case Bytecodes::_astore_0: store_local_object(0); break;
1014 case Bytecodes::_astore_1: store_local_object(1); break;
1015 case Bytecodes::_astore_2: store_local_object(2); break;
1016 case Bytecodes::_astore_3: store_local_object(3); break;
1017
1018 case Bytecodes::_athrow:
1019 {
1020 NEEDS_CLEANUP;
1021 pop_object();
1022 break;
1023 }
1024 case Bytecodes::_baload:
1025 case Bytecodes::_caload:
1026 case Bytecodes::_iaload:
1027 case Bytecodes::_saload:
1028 {
1029 pop_int();
1030 ciTypeArrayKlass* array_klass = pop_typeArray();
1031 // Put assert here for right type?
1032 push_int();
1033 break;
1034 }
1035 case Bytecodes::_bastore:
1036 case Bytecodes::_castore:
1037 case Bytecodes::_iastore:
1038 case Bytecodes::_sastore:
1039 {
1040 pop_int();
1041 pop_int();
1042 pop_typeArray();
1043 // assert here?
1044 break;
1045 }
1046 case Bytecodes::_bipush:
1047 case Bytecodes::_iconst_m1:
1048 case Bytecodes::_iconst_0:
1049 case Bytecodes::_iconst_1:
1050 case Bytecodes::_iconst_2:
1051 case Bytecodes::_iconst_3:
1052 case Bytecodes::_iconst_4:
1053 case Bytecodes::_iconst_5:
1054 case Bytecodes::_sipush:
1055 {
1056 push_int();
1057 break;
1058 }
1059 case Bytecodes::_checkcast: do_checkcast(str); break;
1060
1061 case Bytecodes::_d2f:
1062 {
1063 pop_double();
1064 push_float();
1065 break;
1066 }
1067 case Bytecodes::_d2i:
1068 {
1069 pop_double();
1070 push_int();
1071 break;
1072 }
1073 case Bytecodes::_d2l:
1074 {
1075 pop_double();
1076 push_long();
1077 break;
1078 }
1079 case Bytecodes::_dadd:
1080 case Bytecodes::_ddiv:
1081 case Bytecodes::_dmul:
1082 case Bytecodes::_drem:
1083 case Bytecodes::_dsub:
1084 {
1085 pop_double();
1086 pop_double();
1087 push_double();
1088 break;
1089 }
1090 case Bytecodes::_daload:
1091 {
1092 pop_int();
1093 ciTypeArrayKlass* array_klass = pop_typeArray();
1094 // Put assert here for right type?
1095 push_double();
1096 break;
1097 }
1098 case Bytecodes::_dastore:
1099 {
1100 pop_double();
1101 pop_int();
1102 pop_typeArray();
1103 // assert here?
1104 break;
1105 }
1106 case Bytecodes::_dcmpg:
1107 case Bytecodes::_dcmpl:
1108 {
1109 pop_double();
1110 pop_double();
1111 push_int();
1112 break;
1113 }
1114 case Bytecodes::_dconst_0:
1115 case Bytecodes::_dconst_1:
1116 {
1117 push_double();
1118 break;
1119 }
1120 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1121 case Bytecodes::_dload_0: load_local_double(0); break;
1122 case Bytecodes::_dload_1: load_local_double(1); break;
1123 case Bytecodes::_dload_2: load_local_double(2); break;
1124 case Bytecodes::_dload_3: load_local_double(3); break;
1125
1126 case Bytecodes::_dneg:
1127 {
1128 pop_double();
1129 push_double();
1130 break;
1131 }
1132 case Bytecodes::_dreturn:
1133 {
1134 pop_double();
1135 break;
1136 }
1137 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1138 case Bytecodes::_dstore_0: store_local_double(0); break;
1139 case Bytecodes::_dstore_1: store_local_double(1); break;
1140 case Bytecodes::_dstore_2: store_local_double(2); break;
1141 case Bytecodes::_dstore_3: store_local_double(3); break;
1142
1143 case Bytecodes::_dup:
1144 {
1145 push(type_at_tos());
1146 break;
1147 }
1148 case Bytecodes::_dup_x1:
1149 {
1150 ciType* value1 = pop_value();
1151 ciType* value2 = pop_value();
1152 push(value1);
1153 push(value2);
1154 push(value1);
1155 break;
1156 }
1157 case Bytecodes::_dup_x2:
1158 {
1159 ciType* value1 = pop_value();
1160 ciType* value2 = pop_value();
1161 ciType* value3 = pop_value();
1162 push(value1);
1163 push(value3);
1164 push(value2);
1165 push(value1);
1166 break;
1167 }
1168 case Bytecodes::_dup2:
1169 {
1170 ciType* value1 = pop_value();
1171 ciType* value2 = pop_value();
1172 push(value2);
1173 push(value1);
1174 push(value2);
1175 push(value1);
1176 break;
1177 }
1178 case Bytecodes::_dup2_x1:
1179 {
1180 ciType* value1 = pop_value();
1181 ciType* value2 = pop_value();
1182 ciType* value3 = pop_value();
1183 push(value2);
1184 push(value1);
1185 push(value3);
1186 push(value2);
1187 push(value1);
1188 break;
1189 }
1190 case Bytecodes::_dup2_x2:
1191 {
1192 ciType* value1 = pop_value();
1193 ciType* value2 = pop_value();
1194 ciType* value3 = pop_value();
1195 ciType* value4 = pop_value();
1196 push(value2);
1197 push(value1);
1198 push(value4);
1199 push(value3);
1200 push(value2);
1201 push(value1);
1202 break;
1203 }
1204 case Bytecodes::_f2d:
1205 {
1206 pop_float();
1207 push_double();
1208 break;
1209 }
1210 case Bytecodes::_f2i:
1211 {
1212 pop_float();
1213 push_int();
1214 break;
1215 }
1216 case Bytecodes::_f2l:
1217 {
1218 pop_float();
1219 push_long();
1220 break;
1221 }
1222 case Bytecodes::_fadd:
1223 case Bytecodes::_fdiv:
1224 case Bytecodes::_fmul:
1225 case Bytecodes::_frem:
1226 case Bytecodes::_fsub:
1227 {
1228 pop_float();
1229 pop_float();
1230 push_float();
1231 break;
1232 }
1233 case Bytecodes::_faload:
1234 {
1235 pop_int();
1236 ciTypeArrayKlass* array_klass = pop_typeArray();
1237 // Put assert here.
1238 push_float();
1239 break;
1240 }
1241 case Bytecodes::_fastore:
1242 {
1243 pop_float();
1244 pop_int();
1245 ciTypeArrayKlass* array_klass = pop_typeArray();
1246 // Put assert here.
1247 break;
1248 }
1249 case Bytecodes::_fcmpg:
1250 case Bytecodes::_fcmpl:
1251 {
1252 pop_float();
1253 pop_float();
1254 push_int();
1255 break;
1256 }
1257 case Bytecodes::_fconst_0:
1258 case Bytecodes::_fconst_1:
1259 case Bytecodes::_fconst_2:
1260 {
1261 push_float();
1262 break;
1263 }
1264 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1265 case Bytecodes::_fload_0: load_local_float(0); break;
1266 case Bytecodes::_fload_1: load_local_float(1); break;
1267 case Bytecodes::_fload_2: load_local_float(2); break;
1268 case Bytecodes::_fload_3: load_local_float(3); break;
1269
1270 case Bytecodes::_fneg:
1271 {
1272 pop_float();
1273 push_float();
1274 break;
1275 }
1276 case Bytecodes::_freturn:
1277 {
1278 pop_float();
1279 break;
1280 }
1281 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1282 case Bytecodes::_fstore_0: store_local_float(0); break;
1283 case Bytecodes::_fstore_1: store_local_float(1); break;
1284 case Bytecodes::_fstore_2: store_local_float(2); break;
1285 case Bytecodes::_fstore_3: store_local_float(3); break;
1286
1287 case Bytecodes::_getfield: do_getfield(str); break;
1288 case Bytecodes::_getstatic: do_getstatic(str); break;
1289
1290 case Bytecodes::_goto:
1291 case Bytecodes::_goto_w:
1292 case Bytecodes::_nop:
1293 case Bytecodes::_return:
1294 {
1295 // do nothing.
1296 break;
1297 }
1298 case Bytecodes::_i2b:
1299 case Bytecodes::_i2c:
1300 case Bytecodes::_i2s:
1301 case Bytecodes::_ineg:
1302 {
1303 pop_int();
1304 push_int();
1305 break;
1306 }
1307 case Bytecodes::_i2d:
1308 {
1309 pop_int();
1310 push_double();
1311 break;
1312 }
1313 case Bytecodes::_i2f:
1314 {
1315 pop_int();
1316 push_float();
1317 break;
1318 }
1319 case Bytecodes::_i2l:
1320 {
1321 pop_int();
1322 push_long();
1323 break;
1324 }
1325 case Bytecodes::_iadd:
1326 case Bytecodes::_iand:
1327 case Bytecodes::_idiv:
1328 case Bytecodes::_imul:
1329 case Bytecodes::_ior:
1330 case Bytecodes::_irem:
1331 case Bytecodes::_ishl:
1332 case Bytecodes::_ishr:
1333 case Bytecodes::_isub:
1334 case Bytecodes::_iushr:
1335 case Bytecodes::_ixor:
1336 {
1337 pop_int();
1338 pop_int();
1339 push_int();
1340 break;
1341 }
1342 case Bytecodes::_if_acmpeq:
1343 case Bytecodes::_if_acmpne:
1344 {
1345 pop_object();
1346 pop_object();
1347 break;
1348 }
1349 case Bytecodes::_if_icmpeq:
1350 case Bytecodes::_if_icmpge:
1351 case Bytecodes::_if_icmpgt:
1352 case Bytecodes::_if_icmple:
1353 case Bytecodes::_if_icmplt:
1354 case Bytecodes::_if_icmpne:
1355 {
1356 pop_int();
1357 pop_int();
1358 break;
1359 }
1360 case Bytecodes::_ifeq:
1361 case Bytecodes::_ifle:
1362 case Bytecodes::_iflt:
1363 case Bytecodes::_ifge:
1364 case Bytecodes::_ifgt:
1365 case Bytecodes::_ifne:
1366 case Bytecodes::_ireturn:
1367 case Bytecodes::_lookupswitch:
1368 case Bytecodes::_tableswitch:
1369 {
1370 pop_int();
1371 break;
1372 }
1373 case Bytecodes::_iinc:
1374 {
1375 int lnum = str->get_index();
1376 check_int(local(lnum));
1377 store_to_local(lnum);
1378 break;
1379 }
1380 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1381 case Bytecodes::_iload_0: load_local_int(0); break;
1382 case Bytecodes::_iload_1: load_local_int(1); break;
1383 case Bytecodes::_iload_2: load_local_int(2); break;
1384 case Bytecodes::_iload_3: load_local_int(3); break;
1385
1386 case Bytecodes::_instanceof:
1387 {
1388 // Check for uncommon trap:
1389 do_checkcast(str);
1390 pop_object();
1391 push_int();
1392 break;
1393 }
1394 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1395 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1396 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1397 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1398 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1399
1400 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1401 case Bytecodes::_istore_0: store_local_int(0); break;
1402 case Bytecodes::_istore_1: store_local_int(1); break;
1403 case Bytecodes::_istore_2: store_local_int(2); break;
1404 case Bytecodes::_istore_3: store_local_int(3); break;
1405
1406 case Bytecodes::_jsr:
1407 case Bytecodes::_jsr_w: do_jsr(str); break;
1408
1409 case Bytecodes::_l2d:
1410 {
1411 pop_long();
1412 push_double();
1413 break;
1414 }
1415 case Bytecodes::_l2f:
1416 {
1417 pop_long();
1418 push_float();
1419 break;
1420 }
1421 case Bytecodes::_l2i:
1422 {
1423 pop_long();
1424 push_int();
1425 break;
1426 }
1427 case Bytecodes::_ladd:
1428 case Bytecodes::_land:
1429 case Bytecodes::_ldiv:
1430 case Bytecodes::_lmul:
1431 case Bytecodes::_lor:
1432 case Bytecodes::_lrem:
1433 case Bytecodes::_lsub:
1434 case Bytecodes::_lxor:
1435 {
1436 pop_long();
1437 pop_long();
1438 push_long();
1439 break;
1440 }
1441 case Bytecodes::_laload:
1442 {
1443 pop_int();
1444 ciTypeArrayKlass* array_klass = pop_typeArray();
1445 // Put assert here for right type?
1446 push_long();
1447 break;
1448 }
1449 case Bytecodes::_lastore:
1450 {
1451 pop_long();
1452 pop_int();
1453 pop_typeArray();
1454 // assert here?
1455 break;
1456 }
1457 case Bytecodes::_lcmp:
1458 {
1459 pop_long();
1460 pop_long();
1461 push_int();
1462 break;
1463 }
1464 case Bytecodes::_lconst_0:
1465 case Bytecodes::_lconst_1:
1466 {
1467 push_long();
1468 break;
1469 }
1470 case Bytecodes::_ldc:
1471 case Bytecodes::_ldc_w:
1472 case Bytecodes::_ldc2_w:
1473 {
1474 do_ldc(str);
1475 break;
1476 }
1477
1478 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1479 case Bytecodes::_lload_0: load_local_long(0); break;
1480 case Bytecodes::_lload_1: load_local_long(1); break;
1481 case Bytecodes::_lload_2: load_local_long(2); break;
1482 case Bytecodes::_lload_3: load_local_long(3); break;
1483
1484 case Bytecodes::_lneg:
1485 {
1486 pop_long();
1487 push_long();
1488 break;
1489 }
1490 case Bytecodes::_lreturn:
1491 {
1492 pop_long();
1493 break;
1494 }
1495 case Bytecodes::_lshl:
1496 case Bytecodes::_lshr:
1497 case Bytecodes::_lushr:
1498 {
1499 pop_int();
1500 pop_long();
1501 push_long();
1502 break;
1503 }
1504 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1505 case Bytecodes::_lstore_0: store_local_long(0); break;
1506 case Bytecodes::_lstore_1: store_local_long(1); break;
1507 case Bytecodes::_lstore_2: store_local_long(2); break;
1508 case Bytecodes::_lstore_3: store_local_long(3); break;
1509
1510 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1511
1512 case Bytecodes::_new: do_new(str); break;
1513
1514 case Bytecodes::_newarray: do_newarray(str); break;
1515
1516 case Bytecodes::_pop:
1517 {
1518 pop();
1519 break;
1520 }
1521 case Bytecodes::_pop2:
1522 {
1523 pop();
1524 pop();
1525 break;
1526 }
1527
1528 case Bytecodes::_putfield: do_putfield(str); break;
1529 case Bytecodes::_putstatic: do_putstatic(str); break;
1530
1531 case Bytecodes::_ret: do_ret(str); break;
1532
1533 case Bytecodes::_swap:
1534 {
1535 ciType* value1 = pop_value();
1536 ciType* value2 = pop_value();
1537 push(value1);
1538 push(value2);
1539 break;
1540 }
1541
1542 case Bytecodes::_wide:
1543 default:
1544 {
1545 // The iterator should skip this.
1546 ShouldNotReachHere();
1547 break;
1548 }
1549 }
1550
1551 if (CITraceTypeFlow) {
1552 print_on(tty);
1553 }
1554
1555 return (_trap_bci != -1);
1556 }
1557
1558 #ifndef PRODUCT
1559 // ------------------------------------------------------------------
1560 // ciTypeFlow::StateVector::print_cell_on
1561 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1562 ciType* type = type_at(c)->unwrap();
1563 if (type == top_type()) {
1564 st->print("top");
1565 } else if (type == bottom_type()) {
1566 st->print("bottom");
1567 } else if (type == null_type()) {
1568 st->print("null");
1569 } else if (type == long2_type()) {
1570 st->print("long2");
1571 } else if (type == double2_type()) {
1572 st->print("double2");
1573 } else if (is_int(type)) {
1574 st->print("int");
1575 } else if (is_long(type)) {
1576 st->print("long");
1577 } else if (is_float(type)) {
1578 st->print("float");
1579 } else if (is_double(type)) {
1580 st->print("double");
1581 } else if (type->is_return_address()) {
1582 st->print("address(%d)", type->as_return_address()->bci());
1583 } else {
1584 if (type->is_klass()) {
1585 type->as_klass()->name()->print_symbol_on(st);
1586 } else {
1587 st->print("UNEXPECTED TYPE");
1588 type->print();
1589 }
1590 }
1591 }
1592
1593 // ------------------------------------------------------------------
1594 // ciTypeFlow::StateVector::print_on
1595 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1596 int num_locals = _outer->max_locals();
1597 int num_stack = stack_size();
1598 int num_monitors = monitor_count();
1599 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1600 if (num_stack >= 0) {
1601 int i;
1602 for (i = 0; i < num_locals; i++) {
1603 st->print(" local %2d : ", i);
1604 print_cell_on(st, local(i));
1605 st->cr();
1606 }
1607 for (i = 0; i < num_stack; i++) {
1608 st->print(" stack %2d : ", i);
1609 print_cell_on(st, stack(i));
1610 st->cr();
1611 }
1612 }
1613 }
1614 #endif
1615
1616
1617 // ------------------------------------------------------------------
1618 // ciTypeFlow::SuccIter::next
1619 //
1620 void ciTypeFlow::SuccIter::next() {
1621 int succ_ct = _pred->successors()->length();
1622 int next = _index + 1;
1623 if (next < succ_ct) {
1624 _index = next;
1625 _succ = _pred->successors()->at(next);
1626 return;
1627 }
1628 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1629 // Do not compile any code for unloaded exception types.
1630 // Following compiler passes are responsible for doing this also.
1631 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1632 if (exception_klass->is_loaded()) {
1633 _index = next;
1634 _succ = _pred->exceptions()->at(i);
1635 return;
1636 }
1637 next++;
1638 }
1639 _index = -1;
1640 _succ = nullptr;
1641 }
1642
1643 // ------------------------------------------------------------------
1644 // ciTypeFlow::SuccIter::set_succ
1645 //
1646 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1647 int succ_ct = _pred->successors()->length();
1648 if (_index < succ_ct) {
1649 _pred->successors()->at_put(_index, succ);
1650 } else {
1651 int idx = _index - succ_ct;
1652 _pred->exceptions()->at_put(idx, succ);
1653 }
1654 }
1655
1656 // ciTypeFlow::Block
1657 //
1658 // A basic block.
1659
1660 // ------------------------------------------------------------------
1661 // ciTypeFlow::Block::Block
1662 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1663 ciBlock *ciblk,
1664 ciTypeFlow::JsrSet* jsrs) : _predecessors(outer->arena(), 1, 0, nullptr) {
1665 _ciblock = ciblk;
1666 _exceptions = nullptr;
1667 _exc_klasses = nullptr;
1668 _successors = nullptr;
1669 _state = new (outer->arena()) StateVector(outer);
1670 JsrSet* new_jsrs =
1671 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1672 jsrs->copy_into(new_jsrs);
1673 _jsrs = new_jsrs;
1674 _next = nullptr;
1675 _on_work_list = false;
1676 _backedge_copy = false;
1677 _has_monitorenter = false;
1678 _trap_bci = -1;
1679 _trap_index = 0;
1680 df_init();
1681
1682 if (CITraceTypeFlow) {
1683 tty->print_cr(">> Created new block");
1684 print_on(tty);
1685 }
1686
1687 assert(this->outer() == outer, "outer link set up");
1688 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1689 }
1690
1691 // ------------------------------------------------------------------
1692 // ciTypeFlow::Block::df_init
1693 void ciTypeFlow::Block::df_init() {
1694 _pre_order = -1; assert(!has_pre_order(), "");
1695 _post_order = -1; assert(!has_post_order(), "");
1696 _loop = nullptr;
1697 _irreducible_loop_head = false;
1698 _irreducible_loop_secondary_entry = false;
1699 _rpo_next = nullptr;
1700 }
1701
1702 // ------------------------------------------------------------------
1703 // ciTypeFlow::Block::successors
1704 //
1705 // Get the successors for this Block.
1706 GrowableArray<ciTypeFlow::Block*>*
1707 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1708 ciTypeFlow::StateVector* state,
1709 ciTypeFlow::JsrSet* jsrs) {
1710 if (_successors == nullptr) {
1711 if (CITraceTypeFlow) {
1712 tty->print(">> Computing successors for block ");
1713 print_value_on(tty);
1714 tty->cr();
1715 }
1716
1717 ciTypeFlow* analyzer = outer();
1718 Arena* arena = analyzer->arena();
1719 Block* block = nullptr;
1720 bool has_successor = !has_trap() &&
1721 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1722 if (!has_successor) {
1723 _successors =
1724 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1725 // No successors
1726 } else if (control() == ciBlock::fall_through_bci) {
1727 assert(str->cur_bci() == limit(), "bad block end");
1728 // This block simply falls through to the next.
1729 _successors =
1730 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1731
1732 Block* block = analyzer->block_at(limit(), _jsrs);
1733 assert(_successors->length() == FALL_THROUGH, "");
1734 _successors->append(block);
1735 } else {
1736 int current_bci = str->cur_bci();
1737 int next_bci = str->next_bci();
1738 int branch_bci = -1;
1739 Block* target = nullptr;
1740 assert(str->next_bci() == limit(), "bad block end");
1741 // This block is not a simple fall-though. Interpret
1742 // the current bytecode to find our successors.
1743 switch (str->cur_bc()) {
1744 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1745 case Bytecodes::_iflt: case Bytecodes::_ifge:
1746 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1747 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1748 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1749 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1750 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1751 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1752 // Our successors are the branch target and the next bci.
1753 branch_bci = str->get_dest();
1754 _successors =
1755 new (arena) GrowableArray<Block*>(arena, 2, 0, nullptr);
1756 assert(_successors->length() == IF_NOT_TAKEN, "");
1757 _successors->append(analyzer->block_at(next_bci, jsrs));
1758 assert(_successors->length() == IF_TAKEN, "");
1759 _successors->append(analyzer->block_at(branch_bci, jsrs));
1760 break;
1761
1762 case Bytecodes::_goto:
1763 branch_bci = str->get_dest();
1764 _successors =
1765 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1766 assert(_successors->length() == GOTO_TARGET, "");
1767 _successors->append(analyzer->block_at(branch_bci, jsrs));
1768 break;
1769
1770 case Bytecodes::_jsr:
1771 branch_bci = str->get_dest();
1772 _successors =
1773 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1774 assert(_successors->length() == GOTO_TARGET, "");
1775 _successors->append(analyzer->block_at(branch_bci, jsrs));
1776 break;
1777
1778 case Bytecodes::_goto_w:
1779 case Bytecodes::_jsr_w:
1780 _successors =
1781 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1782 assert(_successors->length() == GOTO_TARGET, "");
1783 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1784 break;
1785
1786 case Bytecodes::_tableswitch: {
1787 Bytecode_tableswitch tableswitch(str);
1788
1789 int len = tableswitch.length();
1790 _successors =
1791 new (arena) GrowableArray<Block*>(arena, len+1, 0, nullptr);
1792 int bci = current_bci + tableswitch.default_offset();
1793 Block* block = analyzer->block_at(bci, jsrs);
1794 assert(_successors->length() == SWITCH_DEFAULT, "");
1795 _successors->append(block);
1796 while (--len >= 0) {
1797 int bci = current_bci + tableswitch.dest_offset_at(len);
1798 block = analyzer->block_at(bci, jsrs);
1799 assert(_successors->length() >= SWITCH_CASES, "");
1800 _successors->append_if_missing(block);
1801 }
1802 break;
1803 }
1804
1805 case Bytecodes::_lookupswitch: {
1806 Bytecode_lookupswitch lookupswitch(str);
1807
1808 int npairs = lookupswitch.number_of_pairs();
1809 _successors =
1810 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, nullptr);
1811 int bci = current_bci + lookupswitch.default_offset();
1812 Block* block = analyzer->block_at(bci, jsrs);
1813 assert(_successors->length() == SWITCH_DEFAULT, "");
1814 _successors->append(block);
1815 while(--npairs >= 0) {
1816 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1817 int bci = current_bci + pair.offset();
1818 Block* block = analyzer->block_at(bci, jsrs);
1819 assert(_successors->length() >= SWITCH_CASES, "");
1820 _successors->append_if_missing(block);
1821 }
1822 break;
1823 }
1824
1825 case Bytecodes::_athrow:
1826 case Bytecodes::_ireturn:
1827 case Bytecodes::_lreturn:
1828 case Bytecodes::_freturn:
1829 case Bytecodes::_dreturn:
1830 case Bytecodes::_areturn:
1831 case Bytecodes::_return:
1832 _successors =
1833 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1834 // No successors
1835 break;
1836
1837 case Bytecodes::_ret: {
1838 _successors =
1839 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr);
1840
1841 Cell local = state->local(str->get_index());
1842 ciType* return_address = state->type_at(local);
1843 assert(return_address->is_return_address(), "verify: wrong type");
1844 int bci = return_address->as_return_address()->bci();
1845 assert(_successors->length() == GOTO_TARGET, "");
1846 _successors->append(analyzer->block_at(bci, jsrs));
1847 break;
1848 }
1849
1850 case Bytecodes::_wide:
1851 default:
1852 ShouldNotReachHere();
1853 break;
1854 }
1855 }
1856
1857 // Set predecessor information
1858 for (int i = 0; i < _successors->length(); i++) {
1859 Block* block = _successors->at(i);
1860 block->predecessors()->append(this);
1861 }
1862 }
1863 return _successors;
1864 }
1865
1866 // ------------------------------------------------------------------
1867 // ciTypeFlow::Block:compute_exceptions
1868 //
1869 // Compute the exceptional successors and types for this Block.
1870 void ciTypeFlow::Block::compute_exceptions() {
1871 assert(_exceptions == nullptr && _exc_klasses == nullptr, "repeat");
1872
1873 if (CITraceTypeFlow) {
1874 tty->print(">> Computing exceptions for block ");
1875 print_value_on(tty);
1876 tty->cr();
1877 }
1878
1879 ciTypeFlow* analyzer = outer();
1880 Arena* arena = analyzer->arena();
1881
1882 // Any bci in the block will do.
1883 ciExceptionHandlerStream str(analyzer->method(), start());
1884
1885 // Allocate our growable arrays.
1886 int exc_count = str.count();
1887 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, nullptr);
1888 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1889 0, nullptr);
1890
1891 for ( ; !str.is_done(); str.next()) {
1892 ciExceptionHandler* handler = str.handler();
1893 int bci = handler->handler_bci();
1894 ciInstanceKlass* klass = nullptr;
1895 if (bci == -1) {
1896 // There is no catch all. It is possible to exit the method.
1897 break;
1898 }
1899 if (handler->is_catch_all()) {
1900 klass = analyzer->env()->Throwable_klass();
1901 } else {
1902 klass = handler->catch_klass();
1903 }
1904 Block* block = analyzer->block_at(bci, _jsrs);
1905 _exceptions->append(block);
1906 block->predecessors()->append(this);
1907 _exc_klasses->append(klass);
1908 }
1909 }
1910
1911 // ------------------------------------------------------------------
1912 // ciTypeFlow::Block::set_backedge_copy
1913 // Use this only to make a pre-existing public block into a backedge copy.
1914 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1915 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1916 _backedge_copy = z;
1917 }
1918
1919 // Analogous to PhaseIdealLoop::is_in_irreducible_loop
1920 bool ciTypeFlow::Block::is_in_irreducible_loop() const {
1921 if (!outer()->has_irreducible_entry()) {
1922 return false; // No irreducible loop in method.
1923 }
1924 Loop* lp = loop(); // Innermost loop containing block.
1925 if (lp == nullptr) {
1926 assert(!is_post_visited(), "must have enclosing loop once post-visited");
1927 return false; // Not yet processed, so we do not know, yet.
1928 }
1929 // Walk all the way up the loop-tree, search for an irreducible loop.
1930 do {
1931 if (lp->is_irreducible()) {
1932 return true; // We are in irreducible loop.
1933 }
1934 if (lp->head()->pre_order() == 0) {
1935 return false; // Found root loop, terminate.
1936 }
1937 lp = lp->parent();
1938 } while (lp != nullptr);
1939 // We have "lp->parent() == nullptr", which happens only for infinite loops,
1940 // where no parent is attached to the loop. We did not find any irreducible
1941 // loop from this block out to lp. Thus lp only has one entry, and no exit
1942 // (it is infinite and reducible). We can always rewrite an infinite loop
1943 // that is nested inside other loops:
1944 // while(condition) { infinite_loop; }
1945 // with an equivalent program where the infinite loop is an outermost loop
1946 // that is not nested in any loop:
1947 // while(condition) { break; } infinite_loop;
1948 // Thus, we can understand lp as an outermost loop, and can terminate and
1949 // conclude: this block is in no irreducible loop.
1950 return false;
1951 }
1952
1953 // ------------------------------------------------------------------
1954 // ciTypeFlow::Block::is_clonable_exit
1955 //
1956 // At most 2 normal successors, one of which continues looping,
1957 // and all exceptional successors must exit.
1958 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1959 int normal_cnt = 0;
1960 int in_loop_cnt = 0;
1961 for (SuccIter iter(this); !iter.done(); iter.next()) {
1962 Block* succ = iter.succ();
1963 if (iter.is_normal_ctrl()) {
1964 if (++normal_cnt > 2) return false;
1965 if (lp->contains(succ->loop())) {
1966 if (++in_loop_cnt > 1) return false;
1967 }
1968 } else {
1969 if (lp->contains(succ->loop())) return false;
1970 }
1971 }
1972 return in_loop_cnt == 1;
1973 }
1974
1975 // ------------------------------------------------------------------
1976 // ciTypeFlow::Block::looping_succ
1977 //
1978 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1979 assert(successors()->length() <= 2, "at most 2 normal successors");
1980 for (SuccIter iter(this); !iter.done(); iter.next()) {
1981 Block* succ = iter.succ();
1982 if (lp->contains(succ->loop())) {
1983 return succ;
1984 }
1985 }
1986 return nullptr;
1987 }
1988
1989 #ifndef PRODUCT
1990 // ------------------------------------------------------------------
1991 // ciTypeFlow::Block::print_value_on
1992 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1993 if (has_pre_order()) st->print("#%-2d ", pre_order());
1994 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1995 st->print("[%d - %d)", start(), limit());
1996 if (is_loop_head()) st->print(" lphd");
1997 if (is_in_irreducible_loop()) st->print(" in_irred");
1998 if (is_irreducible_loop_head()) st->print(" irred_head");
1999 if (is_irreducible_loop_secondary_entry()) st->print(" irred_entry");
2000 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
2001 if (is_backedge_copy()) st->print("/backedge_copy");
2002 }
2003
2004 // ------------------------------------------------------------------
2005 // ciTypeFlow::Block::print_on
2006 void ciTypeFlow::Block::print_on(outputStream* st) const {
2007 if ((Verbose || WizardMode) && (limit() >= 0)) {
2008 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
2009 outer()->method()->print_codes_on(start(), limit(), st);
2010 }
2011 st->print_cr(" ==================================================== ");
2012 st->print (" ");
2013 print_value_on(st);
2014 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
2015 if (loop() && loop()->parent() != nullptr) {
2016 st->print(" loops:");
2017 Loop* lp = loop();
2018 do {
2019 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
2020 if (lp->is_irreducible()) st->print("(ir)");
2021 lp = lp->parent();
2022 } while (lp->parent() != nullptr);
2023 }
2024 st->cr();
2025 _state->print_on(st);
2026 if (_successors == nullptr) {
2027 st->print_cr(" No successor information");
2028 } else {
2029 int num_successors = _successors->length();
2030 st->print_cr(" Successors : %d", num_successors);
2031 for (int i = 0; i < num_successors; i++) {
2032 Block* successor = _successors->at(i);
2033 st->print(" ");
2034 successor->print_value_on(st);
2035 st->cr();
2036 }
2037 }
2038 if (_predecessors.is_empty()) {
2039 st->print_cr(" No predecessor information");
2040 } else {
2041 int num_predecessors = _predecessors.length();
2042 st->print_cr(" Predecessors : %d", num_predecessors);
2043 for (int i = 0; i < num_predecessors; i++) {
2044 Block* predecessor = _predecessors.at(i);
2045 st->print(" ");
2046 predecessor->print_value_on(st);
2047 st->cr();
2048 }
2049 }
2050 if (_exceptions == nullptr) {
2051 st->print_cr(" No exception information");
2052 } else {
2053 int num_exceptions = _exceptions->length();
2054 st->print_cr(" Exceptions : %d", num_exceptions);
2055 for (int i = 0; i < num_exceptions; i++) {
2056 Block* exc_succ = _exceptions->at(i);
2057 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
2058 st->print(" ");
2059 exc_succ->print_value_on(st);
2060 st->print(" -- ");
2061 exc_klass->name()->print_symbol_on(st);
2062 st->cr();
2063 }
2064 }
2065 if (has_trap()) {
2066 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2067 }
2068 st->print_cr(" ==================================================== ");
2069 }
2070 #endif
2071
2072 #ifndef PRODUCT
2073 // ------------------------------------------------------------------
2074 // ciTypeFlow::LocalSet::print_on
2075 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2076 st->print("{");
2077 for (int i = 0; i < max; i++) {
2078 if (test(i)) st->print(" %d", i);
2079 }
2080 if (limit > max) {
2081 st->print(" %d..%d ", max, limit);
2082 }
2083 st->print(" }");
2084 }
2085 #endif
2086
2087 // ciTypeFlow
2088 //
2089 // This is a pass over the bytecodes which computes the following:
2090 // basic block structure
2091 // interpreter type-states (a la the verifier)
2092
2093 // ------------------------------------------------------------------
2094 // ciTypeFlow::ciTypeFlow
2095 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2096 _env = env;
2097 _method = method;
2098 _has_irreducible_entry = false;
2099 _osr_bci = osr_bci;
2100 _failure_reason = nullptr;
2101 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2102 _work_list = nullptr;
2103
2104 int ciblock_count = _method->get_method_blocks()->num_blocks();
2105 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, ciblock_count);
2106 for (int i = 0; i < ciblock_count; i++) {
2107 _idx_to_blocklist[i] = nullptr;
2108 }
2109 _block_map = nullptr; // until all blocks are seen
2110 _jsr_records = nullptr;
2111 }
2112
2113 // ------------------------------------------------------------------
2114 // ciTypeFlow::work_list_next
2115 //
2116 // Get the next basic block from our work list.
2117 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2118 assert(!work_list_empty(), "work list must not be empty");
2119 Block* next_block = _work_list;
2120 _work_list = next_block->next();
2121 next_block->set_next(nullptr);
2122 next_block->set_on_work_list(false);
2123 return next_block;
2124 }
2125
2126 // ------------------------------------------------------------------
2127 // ciTypeFlow::add_to_work_list
2128 //
2129 // Add a basic block to our work list.
2130 // List is sorted by decreasing postorder sort (same as increasing RPO)
2131 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2132 assert(!block->is_on_work_list(), "must not already be on work list");
2133
2134 if (CITraceTypeFlow) {
2135 tty->print(">> Adding block ");
2136 block->print_value_on(tty);
2137 tty->print_cr(" to the work list : ");
2138 }
2139
2140 block->set_on_work_list(true);
2141
2142 // decreasing post order sort
2143
2144 Block* prev = nullptr;
2145 Block* current = _work_list;
2146 int po = block->post_order();
2147 while (current != nullptr) {
2148 if (!current->has_post_order() || po > current->post_order())
2149 break;
2150 prev = current;
2151 current = current->next();
2152 }
2153 if (prev == nullptr) {
2154 block->set_next(_work_list);
2155 _work_list = block;
2156 } else {
2157 block->set_next(current);
2158 prev->set_next(block);
2159 }
2160
2161 if (CITraceTypeFlow) {
2162 tty->cr();
2163 }
2164 }
2165
2166 // ------------------------------------------------------------------
2167 // ciTypeFlow::block_at
2168 //
2169 // Return the block beginning at bci which has a JsrSet compatible
2170 // with jsrs.
2171 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2172 // First find the right ciBlock.
2173 if (CITraceTypeFlow) {
2174 tty->print(">> Requesting block for %d/", bci);
2175 jsrs->print_on(tty);
2176 tty->cr();
2177 }
2178
2179 ciBlock* ciblk = _method->get_method_blocks()->block_containing(bci);
2180 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2181 Block* block = get_block_for(ciblk->index(), jsrs, option);
2182
2183 assert(block == nullptr? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2184
2185 if (CITraceTypeFlow) {
2186 if (block != nullptr) {
2187 tty->print(">> Found block ");
2188 block->print_value_on(tty);
2189 tty->cr();
2190 } else {
2191 tty->print_cr(">> No such block.");
2192 }
2193 }
2194
2195 return block;
2196 }
2197
2198 // ------------------------------------------------------------------
2199 // ciTypeFlow::make_jsr_record
2200 //
2201 // Make a JsrRecord for a given (entry, return) pair, if such a record
2202 // does not already exist.
2203 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2204 int return_address) {
2205 if (_jsr_records == nullptr) {
2206 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2207 2,
2208 0,
2209 nullptr);
2210 }
2211 JsrRecord* record = nullptr;
2212 int len = _jsr_records->length();
2213 for (int i = 0; i < len; i++) {
2214 JsrRecord* record = _jsr_records->at(i);
2215 if (record->entry_address() == entry_address &&
2216 record->return_address() == return_address) {
2217 return record;
2218 }
2219 }
2220
2221 record = new (arena()) JsrRecord(entry_address, return_address);
2222 _jsr_records->append(record);
2223 return record;
2224 }
2225
2226 // ------------------------------------------------------------------
2227 // ciTypeFlow::flow_exceptions
2228 //
2229 // Merge the current state into all exceptional successors at the
2230 // current point in the code.
2231 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2232 GrowableArray<ciInstanceKlass*>* exc_klasses,
2233 ciTypeFlow::StateVector* state) {
2234 int len = exceptions->length();
2235 assert(exc_klasses->length() == len, "must have same length");
2236 for (int i = 0; i < len; i++) {
2237 Block* block = exceptions->at(i);
2238 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2239
2240 if (!exception_klass->is_loaded()) {
2241 // Do not compile any code for unloaded exception types.
2242 // Following compiler passes are responsible for doing this also.
2243 continue;
2244 }
2245
2246 if (block->meet_exception(exception_klass, state)) {
2247 // Block was modified and has PO. Add it to the work list.
2248 if (block->has_post_order() &&
2249 !block->is_on_work_list()) {
2250 add_to_work_list(block);
2251 }
2252 }
2253 }
2254 }
2255
2256 // ------------------------------------------------------------------
2257 // ciTypeFlow::flow_successors
2258 //
2259 // Merge the current state into all successors at the current point
2260 // in the code.
2261 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2262 ciTypeFlow::StateVector* state) {
2263 int len = successors->length();
2264 for (int i = 0; i < len; i++) {
2265 Block* block = successors->at(i);
2266 if (block->meet(state)) {
2267 // Block was modified and has PO. Add it to the work list.
2268 if (block->has_post_order() &&
2269 !block->is_on_work_list()) {
2270 add_to_work_list(block);
2271 }
2272 }
2273 }
2274 }
2275
2276 // ------------------------------------------------------------------
2277 // ciTypeFlow::can_trap
2278 //
2279 // Tells if a given instruction is able to generate an exception edge.
2280 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2281 // Cf. GenerateOopMap::do_exception_edge.
2282 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2283
2284 switch (str.cur_bc()) {
2285 // %%% FIXME: ldc of Class can generate an exception
2286 case Bytecodes::_ldc:
2287 case Bytecodes::_ldc_w:
2288 case Bytecodes::_ldc2_w:
2289 return str.is_in_error();
2290
2291 case Bytecodes::_aload_0:
2292 // These bytecodes can trap for rewriting. We need to assume that
2293 // they do not throw exceptions to make the monitor analysis work.
2294 return false;
2295
2296 case Bytecodes::_ireturn:
2297 case Bytecodes::_lreturn:
2298 case Bytecodes::_freturn:
2299 case Bytecodes::_dreturn:
2300 case Bytecodes::_areturn:
2301 case Bytecodes::_return:
2302 // We can assume the monitor stack is empty in this analysis.
2303 return false;
2304
2305 case Bytecodes::_monitorexit:
2306 // We can assume monitors are matched in this analysis.
2307 return false;
2308
2309 default:
2310 return true;
2311 }
2312 }
2313
2314 // ------------------------------------------------------------------
2315 // ciTypeFlow::clone_loop_heads
2316 //
2317 // Clone the loop heads
2318 bool ciTypeFlow::clone_loop_heads(StateVector* temp_vector, JsrSet* temp_set) {
2319 bool rslt = false;
2320 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2321 Loop* lp = iter.current();
2322 Block* head = lp->head();
2323 if (lp == loop_tree_root() ||
2324 lp->is_irreducible() ||
2325 !head->is_clonable_exit(lp))
2326 continue;
2327
2328 // Avoid BoxLock merge.
2329 if (EliminateNestedLocks && head->has_monitorenter())
2330 continue;
2331
2332 // check not already cloned
2333 if (head->backedge_copy_count() != 0)
2334 continue;
2335
2336 // Don't clone head of OSR loop to get correct types in start block.
2337 if (is_osr_flow() && head->start() == start_bci())
2338 continue;
2339
2340 // check _no_ shared head below us
2341 Loop* ch;
2342 for (ch = lp->child(); ch != nullptr && ch->head() != head; ch = ch->sibling());
2343 if (ch != nullptr)
2344 continue;
2345
2346 // Clone head
2347 Block* new_head = head->looping_succ(lp);
2348 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2349 // Update lp's info
2350 clone->set_loop(lp);
2351 lp->set_head(new_head);
2352 lp->set_tail(clone);
2353 // And move original head into outer loop
2354 head->set_loop(lp->parent());
2355
2356 rslt = true;
2357 }
2358 return rslt;
2359 }
2360
2361 // ------------------------------------------------------------------
2362 // ciTypeFlow::clone_loop_head
2363 //
2364 // Clone lp's head and replace tail's successors with clone.
2365 //
2366 // |
2367 // v
2368 // head <-> body
2369 // |
2370 // v
2371 // exit
2372 //
2373 // new_head
2374 //
2375 // |
2376 // v
2377 // head ----------\
2378 // | |
2379 // | v
2380 // | clone <-> body
2381 // | |
2382 // | /--/
2383 // | |
2384 // v v
2385 // exit
2386 //
2387 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2388 Block* head = lp->head();
2389 Block* tail = lp->tail();
2390 if (CITraceTypeFlow) {
2391 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2392 tty->print(" for predecessor "); tail->print_value_on(tty);
2393 tty->cr();
2394 }
2395 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2396 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2397
2398 assert(!clone->has_pre_order(), "just created");
2399 clone->set_next_pre_order();
2400
2401 // Accumulate profiled count for all backedges that share this loop's head
2402 int total_count = lp->profiled_count();
2403 for (Loop* lp1 = lp->parent(); lp1 != nullptr; lp1 = lp1->parent()) {
2404 for (Loop* lp2 = lp1; lp2 != nullptr; lp2 = lp2->sibling()) {
2405 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2406 total_count += lp2->profiled_count();
2407 }
2408 }
2409 }
2410 // Have the most frequent ones branch to the clone instead
2411 int count = 0;
2412 int loops_with_shared_head = 0;
2413 Block* latest_tail = tail;
2414 bool done = false;
2415 for (Loop* lp1 = lp; lp1 != nullptr && !done; lp1 = lp1->parent()) {
2416 for (Loop* lp2 = lp1; lp2 != nullptr && !done; lp2 = lp2->sibling()) {
2417 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) {
2418 count += lp2->profiled_count();
2419 if (lp2->tail()->post_order() < latest_tail->post_order()) {
2420 latest_tail = lp2->tail();
2421 }
2422 loops_with_shared_head++;
2423 for (SuccIter iter(lp2->tail()); !iter.done(); iter.next()) {
2424 if (iter.succ() == head) {
2425 iter.set_succ(clone);
2426 // Update predecessor information
2427 head->predecessors()->remove(lp2->tail());
2428 clone->predecessors()->append(lp2->tail());
2429 }
2430 }
2431 flow_block(lp2->tail(), temp_vector, temp_set);
2432 if (lp2->head() == lp2->tail()) {
2433 // For self-loops, clone->head becomes clone->clone
2434 flow_block(clone, temp_vector, temp_set);
2435 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2436 if (iter.succ() == lp2->head()) {
2437 iter.set_succ(clone);
2438 // Update predecessor information
2439 lp2->head()->predecessors()->remove(clone);
2440 clone->predecessors()->append(clone);
2441 break;
2442 }
2443 }
2444 }
2445 if (total_count == 0 || count > (total_count * .9)) {
2446 done = true;
2447 }
2448 }
2449 }
2450 }
2451 assert(loops_with_shared_head >= 1, "at least one new");
2452 clone->set_rpo_next(latest_tail->rpo_next());
2453 latest_tail->set_rpo_next(clone);
2454 flow_block(clone, temp_vector, temp_set);
2455
2456 return clone;
2457 }
2458
2459 // ------------------------------------------------------------------
2460 // ciTypeFlow::flow_block
2461 //
2462 // Interpret the effects of the bytecodes on the incoming state
2463 // vector of a basic block. Push the changed state to succeeding
2464 // basic blocks.
2465 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2466 ciTypeFlow::StateVector* state,
2467 ciTypeFlow::JsrSet* jsrs) {
2468 if (CITraceTypeFlow) {
2469 tty->print("\n>> ANALYZING BLOCK : ");
2470 tty->cr();
2471 block->print_on(tty);
2472 }
2473 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2474
2475 int start = block->start();
2476 int limit = block->limit();
2477 int control = block->control();
2478 if (control != ciBlock::fall_through_bci) {
2479 limit = control;
2480 }
2481
2482 // Grab the state from the current block.
2483 block->copy_state_into(state);
2484 state->def_locals()->clear();
2485
2486 GrowableArray<Block*>* exceptions = block->exceptions();
2487 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2488 bool has_exceptions = exceptions->length() > 0;
2489
2490 bool exceptions_used = false;
2491
2492 ciBytecodeStream str(method());
2493 str.reset_to_bci(start);
2494 Bytecodes::Code code;
2495 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2496 str.cur_bci() < limit) {
2497 // Check for exceptional control flow from this point.
2498 if (has_exceptions && can_trap(str)) {
2499 flow_exceptions(exceptions, exc_klasses, state);
2500 exceptions_used = true;
2501 }
2502 // Apply the effects of the current bytecode to our state.
2503 bool res = state->apply_one_bytecode(&str);
2504
2505 // Watch for bailouts.
2506 if (failing()) return;
2507
2508 if (str.cur_bc() == Bytecodes::_monitorenter) {
2509 block->set_has_monitorenter();
2510 }
2511
2512 if (res) {
2513
2514 // We have encountered a trap. Record it in this block.
2515 block->set_trap(state->trap_bci(), state->trap_index());
2516
2517 if (CITraceTypeFlow) {
2518 tty->print_cr(">> Found trap");
2519 block->print_on(tty);
2520 }
2521
2522 // Save set of locals defined in this block
2523 block->def_locals()->add(state->def_locals());
2524
2525 // Record (no) successors.
2526 block->successors(&str, state, jsrs);
2527
2528 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2529
2530 // Discontinue interpretation of this Block.
2531 return;
2532 }
2533 }
2534
2535 GrowableArray<Block*>* successors = nullptr;
2536 if (control != ciBlock::fall_through_bci) {
2537 // Check for exceptional control flow from this point.
2538 if (has_exceptions && can_trap(str)) {
2539 flow_exceptions(exceptions, exc_klasses, state);
2540 exceptions_used = true;
2541 }
2542
2543 // Fix the JsrSet to reflect effect of the bytecode.
2544 block->copy_jsrs_into(jsrs);
2545 jsrs->apply_control(this, &str, state);
2546
2547 // Find successor edges based on old state and new JsrSet.
2548 successors = block->successors(&str, state, jsrs);
2549
2550 // Apply the control changes to the state.
2551 state->apply_one_bytecode(&str);
2552 } else {
2553 // Fall through control
2554 successors = block->successors(&str, nullptr, nullptr);
2555 }
2556
2557 // Save set of locals defined in this block
2558 block->def_locals()->add(state->def_locals());
2559
2560 // Remove untaken exception paths
2561 if (!exceptions_used)
2562 exceptions->clear();
2563
2564 // Pass our state to successors.
2565 flow_successors(successors, state);
2566 }
2567
2568 // ------------------------------------------------------------------
2569 // ciTypeFlow::PreOrderLoops::next
2570 //
2571 // Advance to next loop tree using a preorder, left-to-right traversal.
2572 void ciTypeFlow::PreorderLoops::next() {
2573 assert(!done(), "must not be done.");
2574 if (_current->child() != nullptr) {
2575 _current = _current->child();
2576 } else if (_current->sibling() != nullptr) {
2577 _current = _current->sibling();
2578 } else {
2579 while (_current != _root && _current->sibling() == nullptr) {
2580 _current = _current->parent();
2581 }
2582 if (_current == _root) {
2583 _current = nullptr;
2584 assert(done(), "must be done.");
2585 } else {
2586 assert(_current->sibling() != nullptr, "must be more to do");
2587 _current = _current->sibling();
2588 }
2589 }
2590 }
2591
2592 // If the tail is a branch to the head, retrieve how many times that path was taken from profiling
2593 int ciTypeFlow::Loop::profiled_count() {
2594 if (_profiled_count >= 0) {
2595 return _profiled_count;
2596 }
2597 ciMethodData* methodData = outer()->method()->method_data();
2598 if (!methodData->is_mature()) {
2599 _profiled_count = 0;
2600 return 0;
2601 }
2602 ciTypeFlow::Block* tail = this->tail();
2603 if (tail->control() == -1 || tail->has_trap()) {
2604 _profiled_count = 0;
2605 return 0;
2606 }
2607
2608 ciProfileData* data = methodData->bci_to_data(tail->control());
2609
2610 if (data == nullptr || !data->is_JumpData()) {
2611 _profiled_count = 0;
2612 return 0;
2613 }
2614
2615 ciBytecodeStream iter(outer()->method());
2616 iter.reset_to_bci(tail->control());
2617
2618 bool is_an_if = false;
2619 bool wide = false;
2620 Bytecodes::Code bc = iter.next();
2621 switch (bc) {
2622 case Bytecodes::_ifeq:
2623 case Bytecodes::_ifne:
2624 case Bytecodes::_iflt:
2625 case Bytecodes::_ifge:
2626 case Bytecodes::_ifgt:
2627 case Bytecodes::_ifle:
2628 case Bytecodes::_if_icmpeq:
2629 case Bytecodes::_if_icmpne:
2630 case Bytecodes::_if_icmplt:
2631 case Bytecodes::_if_icmpge:
2632 case Bytecodes::_if_icmpgt:
2633 case Bytecodes::_if_icmple:
2634 case Bytecodes::_if_acmpeq:
2635 case Bytecodes::_if_acmpne:
2636 case Bytecodes::_ifnull:
2637 case Bytecodes::_ifnonnull:
2638 is_an_if = true;
2639 break;
2640 case Bytecodes::_goto_w:
2641 case Bytecodes::_jsr_w:
2642 wide = true;
2643 break;
2644 case Bytecodes::_goto:
2645 case Bytecodes::_jsr:
2646 break;
2647 default:
2648 fatal(" invalid bytecode: %s", Bytecodes::name(iter.cur_bc()));
2649 }
2650
2651 GrowableArray<ciTypeFlow::Block*>* succs = tail->successors();
2652
2653 if (!is_an_if) {
2654 assert(((wide ? iter.get_far_dest() : iter.get_dest()) == head()->start()) == (succs->at(ciTypeFlow::GOTO_TARGET) == head()), "branch should lead to loop head");
2655 if (succs->at(ciTypeFlow::GOTO_TARGET) == head()) {
2656 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2657 return _profiled_count;
2658 }
2659 } else {
2660 assert((iter.get_dest() == head()->start()) == (succs->at(ciTypeFlow::IF_TAKEN) == head()), "bytecode and CFG not consistent");
2661 assert((tail->limit() == head()->start()) == (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()), "bytecode and CFG not consistent");
2662 if (succs->at(ciTypeFlow::IF_TAKEN) == head()) {
2663 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken());
2664 return _profiled_count;
2665 } else if (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()) {
2666 _profiled_count = outer()->method()->scale_count(data->as_BranchData()->not_taken());
2667 return _profiled_count;
2668 }
2669 }
2670
2671 _profiled_count = 0;
2672 return _profiled_count;
2673 }
2674
2675 bool ciTypeFlow::Loop::at_insertion_point(Loop* lp, Loop* current) {
2676 int lp_pre_order = lp->head()->pre_order();
2677 if (current->head()->pre_order() < lp_pre_order) {
2678 return true;
2679 } else if (current->head()->pre_order() > lp_pre_order) {
2680 return false;
2681 }
2682 // In the case of a shared head, make the most frequent head/tail (as reported by profiling) the inner loop
2683 if (current->head() == lp->head()) {
2684 int lp_count = lp->profiled_count();
2685 int current_count = current->profiled_count();
2686 if (current_count < lp_count) {
2687 return true;
2688 } else if (current_count > lp_count) {
2689 return false;
2690 }
2691 }
2692 if (current->tail()->pre_order() > lp->tail()->pre_order()) {
2693 return true;
2694 }
2695 return false;
2696 }
2697
2698 // ------------------------------------------------------------------
2699 // ciTypeFlow::Loop::sorted_merge
2700 //
2701 // Merge the branch lp into this branch, sorting on the loop head
2702 // pre_orders. Returns the leaf of the merged branch.
2703 // Child and sibling pointers will be setup later.
2704 // Sort is (looking from leaf towards the root)
2705 // descending on primary key: loop head's pre_order, and
2706 // ascending on secondary key: loop tail's pre_order.
2707 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2708 Loop* leaf = this;
2709 Loop* prev = nullptr;
2710 Loop* current = leaf;
2711 while (lp != nullptr) {
2712 int lp_pre_order = lp->head()->pre_order();
2713 // Find insertion point for "lp"
2714 while (current != nullptr) {
2715 if (current == lp) {
2716 return leaf; // Already in list
2717 }
2718 if (at_insertion_point(lp, current)) {
2719 break;
2720 }
2721 prev = current;
2722 current = current->parent();
2723 }
2724 Loop* next_lp = lp->parent(); // Save future list of items to insert
2725 // Insert lp before current
2726 lp->set_parent(current);
2727 if (prev != nullptr) {
2728 prev->set_parent(lp);
2729 } else {
2730 leaf = lp;
2731 }
2732 prev = lp; // Inserted item is new prev[ious]
2733 lp = next_lp; // Next item to insert
2734 }
2735 return leaf;
2736 }
2737
2738 // ------------------------------------------------------------------
2739 // ciTypeFlow::build_loop_tree
2740 //
2741 // Incrementally build loop tree.
2742 void ciTypeFlow::build_loop_tree(Block* blk) {
2743 assert(!blk->is_post_visited(), "precondition");
2744 Loop* innermost = nullptr; // merge of loop tree branches over all successors
2745
2746 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2747 Loop* lp = nullptr;
2748 Block* succ = iter.succ();
2749 if (!succ->is_post_visited()) {
2750 // Found backedge since predecessor post visited, but successor is not
2751 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2752
2753 // Create a LoopNode to mark this loop.
2754 lp = new (arena()) Loop(succ, blk);
2755 if (succ->loop() == nullptr)
2756 succ->set_loop(lp);
2757 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2758
2759 } else { // Nested loop
2760 lp = succ->loop();
2761
2762 // If succ is loop head, find outer loop.
2763 while (lp != nullptr && lp->head() == succ) {
2764 lp = lp->parent();
2765 }
2766 if (lp == nullptr) {
2767 // Infinite loop, it's parent is the root
2768 lp = loop_tree_root();
2769 }
2770 }
2771
2772 // Check for irreducible loop.
2773 // Successor has already been visited. If the successor's loop head
2774 // has already been post-visited, then this is another entry into the loop.
2775 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2776 _has_irreducible_entry = true;
2777 lp->set_irreducible(succ);
2778 if (!succ->is_on_work_list()) {
2779 // Assume irreducible entries need more data flow
2780 add_to_work_list(succ);
2781 }
2782 Loop* plp = lp->parent();
2783 if (plp == nullptr) {
2784 // This only happens for some irreducible cases. The parent
2785 // will be updated during a later pass.
2786 break;
2787 }
2788 lp = plp;
2789 }
2790
2791 // Merge loop tree branch for all successors.
2792 innermost = innermost == nullptr ? lp : innermost->sorted_merge(lp);
2793
2794 } // end loop
2795
2796 if (innermost == nullptr) {
2797 assert(blk->successors()->length() == 0, "CFG exit");
2798 blk->set_loop(loop_tree_root());
2799 } else if (innermost->head() == blk) {
2800 // If loop header, complete the tree pointers
2801 if (blk->loop() != innermost) {
2802 #ifdef ASSERT
2803 assert(blk->loop()->head() == innermost->head(), "same head");
2804 Loop* dl;
2805 for (dl = innermost; dl != nullptr && dl != blk->loop(); dl = dl->parent());
2806 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2807 #endif
2808 blk->set_loop(innermost);
2809 }
2810 innermost->def_locals()->add(blk->def_locals());
2811 Loop* l = innermost;
2812 Loop* p = l->parent();
2813 while (p && l->head() == blk) {
2814 l->set_sibling(p->child()); // Put self on parents 'next child'
2815 p->set_child(l); // Make self the first child of parent
2816 p->def_locals()->add(l->def_locals());
2817 l = p; // Walk up the parent chain
2818 p = l->parent();
2819 }
2820 } else {
2821 blk->set_loop(innermost);
2822 innermost->def_locals()->add(blk->def_locals());
2823 }
2824 }
2825
2826 // ------------------------------------------------------------------
2827 // ciTypeFlow::Loop::contains
2828 //
2829 // Returns true if lp is nested loop.
2830 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2831 assert(lp != nullptr, "");
2832 if (this == lp || head() == lp->head()) return true;
2833 int depth1 = depth();
2834 int depth2 = lp->depth();
2835 if (depth1 > depth2)
2836 return false;
2837 while (depth1 < depth2) {
2838 depth2--;
2839 lp = lp->parent();
2840 }
2841 return this == lp;
2842 }
2843
2844 // ------------------------------------------------------------------
2845 // ciTypeFlow::Loop::depth
2846 //
2847 // Loop depth
2848 int ciTypeFlow::Loop::depth() const {
2849 int dp = 0;
2850 for (Loop* lp = this->parent(); lp != nullptr; lp = lp->parent())
2851 dp++;
2852 return dp;
2853 }
2854
2855 #ifndef PRODUCT
2856 // ------------------------------------------------------------------
2857 // ciTypeFlow::Loop::print
2858 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2859 for (int i = 0; i < indent; i++) st->print(" ");
2860 st->print("%d<-%d %s",
2861 is_root() ? 0 : this->head()->pre_order(),
2862 is_root() ? 0 : this->tail()->pre_order(),
2863 is_irreducible()?" irr":"");
2864 st->print(" defs: ");
2865 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2866 st->cr();
2867 for (Loop* ch = child(); ch != nullptr; ch = ch->sibling())
2868 ch->print(st, indent+2);
2869 }
2870 #endif
2871
2872 // ------------------------------------------------------------------
2873 // ciTypeFlow::df_flow_types
2874 //
2875 // Perform the depth first type flow analysis. Helper for flow_types.
2876 void ciTypeFlow::df_flow_types(Block* start,
2877 bool do_flow,
2878 StateVector* temp_vector,
2879 JsrSet* temp_set) {
2880 int dft_len = 100;
2881 GrowableArray<Block*> stk(dft_len);
2882
2883 ciBlock* dummy = _method->get_method_blocks()->make_dummy_block();
2884 JsrSet* root_set = new JsrSet(0);
2885 Block* root_head = new (arena()) Block(this, dummy, root_set);
2886 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2887 root_head->set_pre_order(0);
2888 root_head->set_post_order(0);
2889 root_tail->set_pre_order(max_jint);
2890 root_tail->set_post_order(max_jint);
2891 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2892
2893 stk.push(start);
2894
2895 _next_pre_order = 0; // initialize pre_order counter
2896 _rpo_list = nullptr;
2897 int next_po = 0; // initialize post_order counter
2898
2899 // Compute RPO and the control flow graph
2900 int size;
2901 while ((size = stk.length()) > 0) {
2902 Block* blk = stk.top(); // Leave node on stack
2903 if (!blk->is_visited()) {
2904 // forward arc in graph
2905 assert (!blk->has_pre_order(), "");
2906 blk->set_next_pre_order();
2907
2908 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2909 // Too many basic blocks. Bail out.
2910 // This can happen when try/finally constructs are nested to depth N,
2911 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2912 // "MaxNodeLimit / 2" is used because probably the parser will
2913 // generate at least twice that many nodes and bail out.
2914 record_failure("too many basic blocks");
2915 return;
2916 }
2917 if (do_flow) {
2918 flow_block(blk, temp_vector, temp_set);
2919 if (failing()) return; // Watch for bailouts.
2920 }
2921 } else if (!blk->is_post_visited()) {
2922 // cross or back arc
2923 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2924 Block* succ = iter.succ();
2925 if (!succ->is_visited()) {
2926 stk.push(succ);
2927 }
2928 }
2929 if (stk.length() == size) {
2930 // There were no additional children, post visit node now
2931 stk.pop(); // Remove node from stack
2932
2933 build_loop_tree(blk);
2934 blk->set_post_order(next_po++); // Assign post order
2935 prepend_to_rpo_list(blk);
2936 assert(blk->is_post_visited(), "");
2937
2938 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2939 // Assume loop heads need more data flow
2940 add_to_work_list(blk);
2941 }
2942 }
2943 } else {
2944 stk.pop(); // Remove post-visited node from stack
2945 }
2946 }
2947 }
2948
2949 // ------------------------------------------------------------------
2950 // ciTypeFlow::flow_types
2951 //
2952 // Perform the type flow analysis, creating and cloning Blocks as
2953 // necessary.
2954 void ciTypeFlow::flow_types() {
2955 ResourceMark rm;
2956 StateVector* temp_vector = new StateVector(this);
2957 JsrSet* temp_set = new JsrSet(4);
2958
2959 // Create the method entry block.
2960 Block* start = block_at(start_bci(), temp_set);
2961
2962 // Load the initial state into it.
2963 const StateVector* start_state = get_start_state();
2964 if (failing()) return;
2965 start->meet(start_state);
2966
2967 // Depth first visit
2968 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2969
2970 if (failing()) return;
2971 assert(_rpo_list == start, "must be start");
2972
2973 // Any loops found?
2974 if (loop_tree_root()->child() != nullptr &&
2975 env()->comp_level() >= CompLevel_full_optimization) {
2976 // Loop optimizations are not performed on Tier1 compiles.
2977
2978 bool changed = clone_loop_heads(temp_vector, temp_set);
2979
2980 // If some loop heads were cloned, recompute postorder and loop tree
2981 if (changed) {
2982 loop_tree_root()->set_child(nullptr);
2983 for (Block* blk = _rpo_list; blk != nullptr;) {
2984 Block* next = blk->rpo_next();
2985 blk->df_init();
2986 blk = next;
2987 }
2988 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2989 }
2990 }
2991
2992 if (CITraceTypeFlow) {
2993 tty->print_cr("\nLoop tree");
2994 loop_tree_root()->print();
2995 }
2996
2997 // Continue flow analysis until fixed point reached
2998
2999 debug_only(int max_block = _next_pre_order;)
3000
3001 while (!work_list_empty()) {
3002 Block* blk = work_list_next();
3003 assert (blk->has_post_order(), "post order assigned above");
3004
3005 flow_block(blk, temp_vector, temp_set);
3006
3007 assert (max_block == _next_pre_order, "no new blocks");
3008 assert (!failing(), "no more bailouts");
3009 }
3010 }
3011
3012 // ------------------------------------------------------------------
3013 // ciTypeFlow::map_blocks
3014 //
3015 // Create the block map, which indexes blocks in reverse post-order.
3016 void ciTypeFlow::map_blocks() {
3017 assert(_block_map == nullptr, "single initialization");
3018 int block_ct = _next_pre_order;
3019 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
3020 assert(block_ct == block_count(), "");
3021
3022 Block* blk = _rpo_list;
3023 for (int m = 0; m < block_ct; m++) {
3024 int rpo = blk->rpo();
3025 assert(rpo == m, "should be sequential");
3026 _block_map[rpo] = blk;
3027 blk = blk->rpo_next();
3028 }
3029 assert(blk == nullptr, "should be done");
3030
3031 for (int j = 0; j < block_ct; j++) {
3032 assert(_block_map[j] != nullptr, "must not drop any blocks");
3033 Block* block = _block_map[j];
3034 // Remove dead blocks from successor lists:
3035 for (int e = 0; e <= 1; e++) {
3036 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
3037 for (int k = 0; k < l->length(); k++) {
3038 Block* s = l->at(k);
3039 if (!s->has_post_order()) {
3040 if (CITraceTypeFlow) {
3041 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
3042 s->print_value_on(tty);
3043 tty->cr();
3044 }
3045 l->remove(s);
3046 --k;
3047 }
3048 }
3049 }
3050 }
3051 }
3052
3053 // ------------------------------------------------------------------
3054 // ciTypeFlow::get_block_for
3055 //
3056 // Find a block with this ciBlock which has a compatible JsrSet.
3057 // If no such block exists, create it, unless the option is no_create.
3058 // If the option is create_backedge_copy, always create a fresh backedge copy.
3059 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
3060 Arena* a = arena();
3061 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3062 if (blocks == nullptr) {
3063 // Query only?
3064 if (option == no_create) return nullptr;
3065
3066 // Allocate the growable array.
3067 blocks = new (a) GrowableArray<Block*>(a, 4, 0, nullptr);
3068 _idx_to_blocklist[ciBlockIndex] = blocks;
3069 }
3070
3071 if (option != create_backedge_copy) {
3072 int len = blocks->length();
3073 for (int i = 0; i < len; i++) {
3074 Block* block = blocks->at(i);
3075 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3076 return block;
3077 }
3078 }
3079 }
3080
3081 // Query only?
3082 if (option == no_create) return nullptr;
3083
3084 // We did not find a compatible block. Create one.
3085 Block* new_block = new (a) Block(this, _method->get_method_blocks()->block(ciBlockIndex), jsrs);
3086 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
3087 blocks->append(new_block);
3088 return new_block;
3089 }
3090
3091 // ------------------------------------------------------------------
3092 // ciTypeFlow::backedge_copy_count
3093 //
3094 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
3095 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
3096
3097 if (blocks == nullptr) {
3098 return 0;
3099 }
3100
3101 int count = 0;
3102 int len = blocks->length();
3103 for (int i = 0; i < len; i++) {
3104 Block* block = blocks->at(i);
3105 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
3106 count++;
3107 }
3108 }
3109
3110 return count;
3111 }
3112
3113 // ------------------------------------------------------------------
3114 // ciTypeFlow::do_flow
3115 //
3116 // Perform type inference flow analysis.
3117 void ciTypeFlow::do_flow() {
3118 if (CITraceTypeFlow) {
3119 tty->print_cr("\nPerforming flow analysis on method");
3120 method()->print();
3121 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
3122 tty->cr();
3123 method()->print_codes();
3124 }
3125 if (CITraceTypeFlow) {
3126 tty->print_cr("Initial CI Blocks");
3127 print_on(tty);
3128 }
3129 flow_types();
3130 // Watch for bailouts.
3131 if (failing()) {
3132 return;
3133 }
3134
3135 map_blocks();
3136
3137 if (CIPrintTypeFlow || CITraceTypeFlow) {
3138 rpo_print_on(tty);
3139 }
3140 }
3141
3142 // ------------------------------------------------------------------
3143 // ciTypeFlow::is_dominated_by
3144 //
3145 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3146 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3147 assert(!method()->has_jsrs(), "jsrs are not supported");
3148
3149 ResourceMark rm;
3150 JsrSet* jsrs = new ciTypeFlow::JsrSet();
3151 int index = _method->get_method_blocks()->block_containing(bci)->index();
3152 int dom_index = _method->get_method_blocks()->block_containing(dom_bci)->index();
3153 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3154 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3155
3156 // Start block dominates all other blocks
3157 if (start_block()->rpo() == dom_block->rpo()) {
3158 return true;
3159 }
3160
3161 // Dominated[i] is true if block i is dominated by dom_block
3162 int num_blocks = block_count();
3163 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3164 for (int i = 0; i < num_blocks; ++i) {
3165 dominated[i] = true;
3166 }
3167 dominated[start_block()->rpo()] = false;
3168
3169 // Iterative dominator algorithm
3170 bool changed = true;
3171 while (changed) {
3172 changed = false;
3173 // Use reverse postorder iteration
3174 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3175 if (blk->is_start()) {
3176 // Ignore start block
3177 continue;
3178 }
3179 // The block is dominated if it is the dominating block
3180 // itself or if all predecessors are dominated.
3181 int index = blk->rpo();
3182 bool dom = (index == dom_block->rpo());
3183 if (!dom) {
3184 // Check if all predecessors are dominated
3185 dom = true;
3186 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3187 Block* pred = blk->predecessors()->at(i);
3188 if (!dominated[pred->rpo()]) {
3189 dom = false;
3190 break;
3191 }
3192 }
3193 }
3194 // Update dominator information
3195 if (dominated[index] != dom) {
3196 changed = true;
3197 dominated[index] = dom;
3198 }
3199 }
3200 }
3201 // block dominated by dom_block?
3202 return dominated[block->rpo()];
3203 }
3204
3205 // ------------------------------------------------------------------
3206 // ciTypeFlow::record_failure()
3207 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3208 // This is required because there is not a 1-1 relation between the ciEnv and
3209 // the TypeFlow passes within a compilation task. For example, if the compiler
3210 // is considering inlining a method, it will request a TypeFlow. If that fails,
3211 // the compilation as a whole may continue without the inlining. Some TypeFlow
3212 // requests are not optional; if they fail the requestor is responsible for
3213 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3214 void ciTypeFlow::record_failure(const char* reason) {
3215 if (env()->log() != nullptr) {
3216 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3217 }
3218 if (_failure_reason == nullptr) {
3219 // Record the first failure reason.
3220 _failure_reason = reason;
3221 }
3222 }
3223
3224 ciType* ciTypeFlow::mark_as_null_free(ciType* type) {
3225 // Wrap the type to carry the information that it is null-free
3226 return env()->make_null_free_wrapper(type);
3227 }
3228
3229 #ifndef PRODUCT
3230 void ciTypeFlow::print() const { print_on(tty); }
3231
3232 // ------------------------------------------------------------------
3233 // ciTypeFlow::print_on
3234 void ciTypeFlow::print_on(outputStream* st) const {
3235 // Walk through CI blocks
3236 st->print_cr("********************************************************");
3237 st->print ("TypeFlow for ");
3238 method()->name()->print_symbol_on(st);
3239 int limit_bci = code_size();
3240 st->print_cr(" %d bytes", limit_bci);
3241 ciMethodBlocks* mblks = _method->get_method_blocks();
3242 ciBlock* current = nullptr;
3243 for (int bci = 0; bci < limit_bci; bci++) {
3244 ciBlock* blk = mblks->block_containing(bci);
3245 if (blk != nullptr && blk != current) {
3246 current = blk;
3247 current->print_on(st);
3248
3249 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3250 int num_blocks = (blocks == nullptr) ? 0 : blocks->length();
3251
3252 if (num_blocks == 0) {
3253 st->print_cr(" No Blocks");
3254 } else {
3255 for (int i = 0; i < num_blocks; i++) {
3256 Block* block = blocks->at(i);
3257 block->print_on(st);
3258 }
3259 }
3260 st->print_cr("--------------------------------------------------------");
3261 st->cr();
3262 }
3263 }
3264 st->print_cr("********************************************************");
3265 st->cr();
3266 }
3267
3268 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3269 st->print_cr("********************************************************");
3270 st->print ("TypeFlow for ");
3271 method()->name()->print_symbol_on(st);
3272 int limit_bci = code_size();
3273 st->print_cr(" %d bytes", limit_bci);
3274 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) {
3275 blk->print_on(st);
3276 st->print_cr("--------------------------------------------------------");
3277 st->cr();
3278 }
3279 st->print_cr("********************************************************");
3280 st->cr();
3281 }
3282 #endif