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