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