1 /*
2 * Copyright (c) 2000, 2018, 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.
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23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciMethod.hpp"
29 #include "ci/ciMethodData.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "ci/ciTypeArrayKlass.hpp"
33 #include "ci/ciTypeFlow.hpp"
34 #include "ci/ciValueKlass.hpp"
35 #include "compiler/compileLog.hpp"
36 #include "interpreter/bytecode.hpp"
37 #include "interpreter/bytecodes.hpp"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "opto/compile.hpp"
42 #include "opto/node.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "utilities/growableArray.hpp"
45
46 // ciTypeFlow::JsrSet
47 //
48 // A JsrSet represents some set of JsrRecords. This class
49 // is used to record a set of all jsr routines which we permit
50 // execution to return (ret) from.
51 //
52 // During abstract interpretation, JsrSets are used to determine
53 // whether two paths which reach a given block are unique, and
54 // should be cloned apart, or are compatible, and should merge
55 // together.
56
57 // ------------------------------------------------------------------
58 // ciTypeFlow::JsrSet::JsrSet
59 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
60 if (arena != NULL) {
61 // Allocate growable array in Arena.
62 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
63 } else {
64 // Allocate growable array in current ResourceArea.
65 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
66 }
67 }
68
69 // ------------------------------------------------------------------
70 // ciTypeFlow::JsrSet::copy_into
71 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
72 int len = size();
73 jsrs->_set->clear();
74 for (int i = 0; i < len; i++) {
75 jsrs->_set->append(_set->at(i));
76 }
77 }
78
79 // ------------------------------------------------------------------
80 // ciTypeFlow::JsrSet::is_compatible_with
81 //
82 // !!!! MISGIVINGS ABOUT THIS... disregard
83 //
84 // Is this JsrSet compatible with some other JsrSet?
85 //
86 // In set-theoretic terms, a JsrSet can be viewed as a partial function
87 // from entry addresses to return addresses. Two JsrSets A and B are
88 // compatible iff
89 //
90 // For any x,
91 // A(x) defined and B(x) defined implies A(x) == B(x)
92 //
93 // Less formally, two JsrSets are compatible when they have identical
94 // return addresses for any entry addresses they share in common.
95 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
96 // Walk through both sets in parallel. If the same entry address
97 // appears in both sets, then the return address must match for
98 // the sets to be compatible.
99 int size1 = size();
100 int size2 = other->size();
101
102 // Special case. If nothing is on the jsr stack, then there can
103 // be no ret.
104 if (size2 == 0) {
105 return true;
106 } else if (size1 != size2) {
107 return false;
108 } else {
109 for (int i = 0; i < size1; i++) {
110 JsrRecord* record1 = record_at(i);
111 JsrRecord* record2 = other->record_at(i);
112 if (record1->entry_address() != record2->entry_address() ||
113 record1->return_address() != record2->return_address()) {
114 return false;
115 }
116 }
117 return true;
118 }
119
120 #if 0
121 int pos1 = 0;
122 int pos2 = 0;
123 int size1 = size();
124 int size2 = other->size();
125 while (pos1 < size1 && pos2 < size2) {
126 JsrRecord* record1 = record_at(pos1);
127 JsrRecord* record2 = other->record_at(pos2);
128 int entry1 = record1->entry_address();
129 int entry2 = record2->entry_address();
130 if (entry1 < entry2) {
131 pos1++;
132 } else if (entry1 > entry2) {
133 pos2++;
134 } else {
135 if (record1->return_address() == record2->return_address()) {
136 pos1++;
137 pos2++;
138 } else {
139 // These two JsrSets are incompatible.
140 return false;
141 }
142 }
143 }
144 // The two JsrSets agree.
145 return true;
146 #endif
147 }
148
149 // ------------------------------------------------------------------
150 // ciTypeFlow::JsrSet::insert_jsr_record
151 //
152 // Insert the given JsrRecord into the JsrSet, maintaining the order
153 // of the set and replacing any element with the same entry address.
154 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
155 int len = size();
156 int entry = record->entry_address();
157 int pos = 0;
158 for ( ; pos < len; pos++) {
159 JsrRecord* current = record_at(pos);
160 if (entry == current->entry_address()) {
161 // Stomp over this entry.
162 _set->at_put(pos, record);
163 assert(size() == len, "must be same size");
164 return;
165 } else if (entry < current->entry_address()) {
166 break;
167 }
168 }
169
170 // Insert the record into the list.
171 JsrRecord* swap = record;
172 JsrRecord* temp = NULL;
173 for ( ; pos < len; pos++) {
174 temp = _set->at(pos);
175 _set->at_put(pos, swap);
176 swap = temp;
177 }
178 _set->append(swap);
179 assert(size() == len+1, "must be larger");
180 }
181
182 // ------------------------------------------------------------------
183 // ciTypeFlow::JsrSet::remove_jsr_record
184 //
185 // Remove the JsrRecord with the given return address from the JsrSet.
186 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
187 int len = size();
188 for (int i = 0; i < len; i++) {
189 if (record_at(i)->return_address() == return_address) {
190 // We have found the proper entry. Remove it from the
191 // JsrSet and exit.
192 for (int j = i+1; j < len ; j++) {
193 _set->at_put(j-1, _set->at(j));
194 }
195 _set->trunc_to(len-1);
196 assert(size() == len-1, "must be smaller");
197 return;
198 }
199 }
200 assert(false, "verify: returning from invalid subroutine");
201 }
202
203 // ------------------------------------------------------------------
204 // ciTypeFlow::JsrSet::apply_control
205 //
206 // Apply the effect of a control-flow bytecode on the JsrSet. The
207 // only bytecodes that modify the JsrSet are jsr and ret.
208 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
209 ciBytecodeStream* str,
210 ciTypeFlow::StateVector* state) {
211 Bytecodes::Code code = str->cur_bc();
212 if (code == Bytecodes::_jsr) {
213 JsrRecord* record =
214 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
215 insert_jsr_record(record);
216 } else if (code == Bytecodes::_jsr_w) {
217 JsrRecord* record =
218 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
219 insert_jsr_record(record);
220 } else if (code == Bytecodes::_ret) {
221 Cell local = state->local(str->get_index());
222 ciType* return_address = state->type_at(local);
223 assert(return_address->is_return_address(), "verify: wrong type");
224 if (size() == 0) {
225 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
226 // This can happen when a loop is inside a finally clause (4614060).
227 analyzer->record_failure("OSR in finally clause");
228 return;
229 }
230 remove_jsr_record(return_address->as_return_address()->bci());
231 }
232 }
233
234 #ifndef PRODUCT
235 // ------------------------------------------------------------------
236 // ciTypeFlow::JsrSet::print_on
237 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
238 st->print("{ ");
239 int num_elements = size();
240 if (num_elements > 0) {
241 int i = 0;
242 for( ; i < num_elements - 1; i++) {
243 _set->at(i)->print_on(st);
244 st->print(", ");
245 }
246 _set->at(i)->print_on(st);
247 st->print(" ");
248 }
249 st->print("}");
250 }
251 #endif
252
253 // ciTypeFlow::StateVector
254 //
255 // A StateVector summarizes the type information at some point in
256 // the program.
257
258 // ------------------------------------------------------------------
259 // ciTypeFlow::StateVector::type_meet
260 //
261 // Meet two types.
262 //
263 // The semi-lattice of types use by this analysis are modeled on those
264 // of the verifier. The lattice is as follows:
265 //
266 // top_type() >= all non-extremal types >= bottom_type
267 // and
268 // Every primitive type is comparable only with itself. The meet of
269 // reference types is determined by their kind: instance class,
270 // interface, or array class. The meet of two types of the same
271 // kind is their least common ancestor. The meet of two types of
272 // different kinds is always java.lang.Object.
273 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
274 assert(t1 != t2, "checked in caller");
275
276 if (t1->equals(top_type())) {
277 return t2;
278 } else if (t2->equals(top_type())) {
279 return t1;
280 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
281 // Special case null_type. null_type meet any reference type T
282 // is T. null_type meet null_type is null_type.
283 if (t1->equals(null_type())) {
284 if (!t2->is_primitive_type() || t2->equals(null_type())) {
285 return t2;
286 }
287 } else if (t2->equals(null_type())) {
288 if (!t1->is_primitive_type()) {
289 return t1;
290 }
291 }
292
293 // At least one of the two types is a non-top primitive type.
294 // The other type is not equal to it. Fall to bottom.
295 return bottom_type();
296 }
297
298 // Unwrap the types after gathering nullness information
299 bool never_null1 = t1->is_never_null();
300 bool never_null2 = t2->is_never_null();
301 t1 = t1->unwrap();
302 t2 = t2->unwrap();
303
304 // Both types are non-top non-primitive types. That is,
305 // both types are either instanceKlasses or arrayKlasses.
306 ciKlass* object_klass = analyzer->env()->Object_klass();
307 ciKlass* k1 = t1->as_klass();
308 ciKlass* k2 = t2->as_klass();
309 if (k1->equals(object_klass) || k2->equals(object_klass)) {
310 return object_klass;
311 } else if (!k1->is_loaded() || !k2->is_loaded()) {
312 // Unloaded classes fall to java.lang.Object at a merge.
313 return object_klass;
314 } else if (k1->is_interface() != k2->is_interface()) {
315 // When an interface meets a non-interface, we get Object;
316 // This is what the verifier does.
317 return object_klass;
318 } else if (k1->is_array_klass() || k2->is_array_klass()) {
319 // When an array meets a non-array, we get Object.
320 // When objArray meets typeArray, we also get Object.
321 // And when typeArray meets different typeArray, we again get Object.
322 // But when objArray meets objArray, we look carefully at element types.
323 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
324 // Meet the element types, then construct the corresponding array type.
325 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
326 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
327 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
328 // Do an easy shortcut if one type is a super of the other.
329 if (elem == elem1) {
330 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
331 return k1;
332 } else if (elem == elem2) {
333 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
334 return k2;
335 } else {
336 return ciObjArrayKlass::make(elem);
337 }
338 } else if (k1->is_value_array_klass() || k2->is_value_array_klass()) {
339 ciKlass* elem1 = k1->as_array_klass()->element_klass();
340 ciKlass* elem2 = k2->as_array_klass()->element_klass();
341 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
342 return ciArrayKlass::make(elem);
343 } else {
344 return object_klass;
345 }
346 } else {
347 // Must be two plain old instance klasses.
348 assert(k1->is_instance_klass(), "previous cases handle non-instances");
349 assert(k2->is_instance_klass(), "previous cases handle non-instances");
350 ciType* result = k1->least_common_ancestor(k2);
351 if (never_null1 && never_null2 && result->is_valuetype()) {
352 // Both value types are never null, mark the result as never null
353 result = analyzer->mark_as_never_null(result);
354 }
355 return result;
356 }
357 }
358
359
360 // ------------------------------------------------------------------
361 // ciTypeFlow::StateVector::StateVector
362 //
363 // Build a new state vector
364 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
365 _outer = analyzer;
366 _stack_size = -1;
367 _monitor_count = -1;
368 // Allocate the _types array
369 int max_cells = analyzer->max_cells();
370 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
371 for (int i=0; i<max_cells; i++) {
372 _types[i] = top_type();
373 }
374 _trap_bci = -1;
375 _trap_index = 0;
376 _def_locals.clear();
377 }
378
379
380 // ------------------------------------------------------------------
381 // ciTypeFlow::get_start_state
382 //
383 // Set this vector to the method entry state.
384 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
385 StateVector* state = new StateVector(this);
386 if (is_osr_flow()) {
387 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
388 if (non_osr_flow->failing()) {
389 record_failure(non_osr_flow->failure_reason());
390 return NULL;
391 }
392 JsrSet* jsrs = new JsrSet(NULL, 16);
393 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
394 if (non_osr_block == NULL) {
395 record_failure("cannot reach OSR point");
396 return NULL;
397 }
398 // load up the non-OSR state at this point
399 non_osr_block->copy_state_into(state);
400 int non_osr_start = non_osr_block->start();
401 if (non_osr_start != start_bci()) {
402 // must flow forward from it
403 if (CITraceTypeFlow) {
404 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
405 }
406 Block* block = block_at(non_osr_start, jsrs);
407 assert(block->limit() == start_bci(), "must flow forward to start");
408 flow_block(block, state, jsrs);
409 }
410 return state;
411 // Note: The code below would be an incorrect for an OSR flow,
412 // even if it were possible for an OSR entry point to be at bci zero.
413 }
414 // "Push" the method signature into the first few locals.
415 state->set_stack_size(-max_locals());
416 if (!method()->is_static()) {
417 ciType* holder = method()->holder();
418 if (holder->is_valuetype()) {
419 // The receiver is never null
420 holder = mark_as_never_null(holder);
421 }
422 state->push(holder);
423 assert(state->tos() == state->local(0), "");
424 }
425 for (ciSignatureStream str(method()->signature());
426 !str.at_return_type();
427 str.next()) {
428 ciType* arg = str.type();
429 if (str.is_never_null()) {
430 arg = mark_as_never_null(arg);
431 }
432 state->push_translate(arg);
433 }
434 // Set the rest of the locals to bottom.
435 Cell cell = state->next_cell(state->tos());
436 state->set_stack_size(0);
437 int limit = state->limit_cell();
438 for (; cell < limit; cell = state->next_cell(cell)) {
439 state->set_type_at(cell, state->bottom_type());
440 }
441 // Lock an object, if necessary.
442 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
443 return state;
444 }
445
446 // ------------------------------------------------------------------
447 // ciTypeFlow::StateVector::copy_into
448 //
449 // Copy our value into some other StateVector
450 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
451 const {
452 copy->set_stack_size(stack_size());
453 copy->set_monitor_count(monitor_count());
454 Cell limit = limit_cell();
455 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
456 copy->set_type_at(c, type_at(c));
457 }
458 }
459
460 // ------------------------------------------------------------------
461 // ciTypeFlow::StateVector::meet
462 //
463 // Meets this StateVector with another, destructively modifying this
464 // one. Returns true if any modification takes place.
465 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
466 if (monitor_count() == -1) {
467 set_monitor_count(incoming->monitor_count());
468 }
469 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
470
471 if (stack_size() == -1) {
472 set_stack_size(incoming->stack_size());
473 Cell limit = limit_cell();
474 #ifdef ASSERT
475 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
476 assert(type_at(c) == top_type(), "");
477 } }
478 #endif
479 // Make a simple copy of the incoming state.
480 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
481 set_type_at(c, incoming->type_at(c));
482 }
483 return true; // it is always different the first time
484 }
485 #ifdef ASSERT
486 if (stack_size() != incoming->stack_size()) {
487 _outer->method()->print_codes();
488 tty->print_cr("!!!! Stack size conflict");
489 tty->print_cr("Current state:");
490 print_on(tty);
491 tty->print_cr("Incoming state:");
492 ((StateVector*)incoming)->print_on(tty);
493 }
494 #endif
495 assert(stack_size() == incoming->stack_size(), "sanity");
496
497 bool different = false;
498 Cell limit = limit_cell();
499 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
500 ciType* t1 = type_at(c);
501 ciType* t2 = incoming->type_at(c);
502 if (!t1->equals(t2)) {
503 ciType* new_type = type_meet(t1, t2);
504 if (!t1->equals(new_type)) {
505 set_type_at(c, new_type);
506 different = true;
507 }
508 }
509 }
510 return different;
511 }
512
513 // ------------------------------------------------------------------
514 // ciTypeFlow::StateVector::meet_exception
515 //
516 // Meets this StateVector with another, destructively modifying this
517 // one. The incoming state is coming via an exception. Returns true
518 // if any modification takes place.
519 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
520 const ciTypeFlow::StateVector* incoming) {
521 if (monitor_count() == -1) {
522 set_monitor_count(incoming->monitor_count());
523 }
524 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
525
526 if (stack_size() == -1) {
527 set_stack_size(1);
528 }
529
530 assert(stack_size() == 1, "must have one-element stack");
531
532 bool different = false;
533
534 // Meet locals from incoming array.
535 Cell limit = local(_outer->max_locals()-1);
536 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
537 ciType* t1 = type_at(c);
538 ciType* t2 = incoming->type_at(c);
539 if (!t1->equals(t2)) {
540 ciType* new_type = type_meet(t1, t2);
541 if (!t1->equals(new_type)) {
542 set_type_at(c, new_type);
543 different = true;
544 }
545 }
546 }
547
548 // Handle stack separately. When an exception occurs, the
549 // only stack entry is the exception instance.
550 ciType* tos_type = type_at_tos();
551 if (!tos_type->equals(exc)) {
552 ciType* new_type = type_meet(tos_type, exc);
553 if (!tos_type->equals(new_type)) {
554 set_type_at_tos(new_type);
555 different = true;
556 }
557 }
558
559 return different;
560 }
561
562 // ------------------------------------------------------------------
563 // ciTypeFlow::StateVector::push_translate
564 void ciTypeFlow::StateVector::push_translate(ciType* type) {
565 BasicType basic_type = type->basic_type();
566 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
567 basic_type == T_BYTE || basic_type == T_SHORT) {
568 push_int();
569 } else {
570 push(type);
571 if (type->is_two_word()) {
572 push(half_type(type));
573 }
574 }
575 }
576
577 // ------------------------------------------------------------------
578 // ciTypeFlow::StateVector::do_aload
579 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
580 pop_int();
581 ciArrayKlass* array_klass = pop_objOrValueArray();
582 if (array_klass == NULL) {
583 // Did aload on a null reference; push a null and ignore the exception.
584 // This instruction will never continue normally. All we have to do
585 // is report a value that will meet correctly with any downstream
586 // reference types on paths that will truly be executed. This null type
587 // meets with any reference type to yield that same reference type.
588 // (The compiler will generate an unconditional exception here.)
589 push(null_type());
590 return;
591 }
592 if (!array_klass->is_loaded()) {
593 // Only fails for some -Xcomp runs
594 trap(str, array_klass,
595 Deoptimization::make_trap_request
596 (Deoptimization::Reason_unloaded,
597 Deoptimization::Action_reinterpret));
598 return;
599 }
600 ciKlass* element_klass = array_klass->element_klass();
601 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
602 Untested("unloaded array element class in ciTypeFlow");
603 trap(str, element_klass,
604 Deoptimization::make_trap_request
605 (Deoptimization::Reason_unloaded,
606 Deoptimization::Action_reinterpret));
607 } else {
608 if (element_klass->is_valuetype()) {
609 // Value type array elements are never null
610 push(outer()->mark_as_never_null(element_klass));
611 } else {
612 push_object(element_klass);
613 }
614 }
615 }
616
617
618 // ------------------------------------------------------------------
619 // ciTypeFlow::StateVector::do_checkcast
620 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
621 bool will_link;
622 ciKlass* klass = str->get_klass(will_link);
623 if (!will_link) {
624 // VM's interpreter will not load 'klass' if object is NULL.
625 // Type flow after this block may still be needed in two situations:
626 // 1) C2 uses do_null_assert() and continues compilation for later blocks
627 // 2) C2 does an OSR compile in a later block (see bug 4778368).
628 pop_object();
629 do_null_assert(klass);
630 } else {
631 pop_object();
632 if (str->get_never_null()) {
633 // Casting to a Q-Type contains a NULL check
634 assert(klass->is_valuetype(), "must be a value type");
635 push(outer()->mark_as_never_null(klass));
636 } else {
637 push_object(klass);
638 }
639 }
640 }
641
642 // ------------------------------------------------------------------
643 // ciTypeFlow::StateVector::do_getfield
644 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
645 // could add assert here for type of object.
646 pop_object();
647 do_getstatic(str);
648 }
649
650 // ------------------------------------------------------------------
651 // ciTypeFlow::StateVector::do_getstatic
652 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
653 bool will_link;
654 ciField* field = str->get_field(will_link);
655 if (!will_link) {
656 trap(str, field->holder(), str->get_field_holder_index());
657 } else {
658 ciType* field_type = field->type();
659 if (!field_type->is_loaded()) {
660 // Normally, we need the field's type to be loaded if we are to
661 // do anything interesting with its value.
662 // We used to do this: trap(str, str->get_field_signature_index());
663 //
664 // There is one good reason not to trap here. Execution can
665 // get past this "getfield" or "getstatic" if the value of
666 // the field is null. As long as the value is null, the class
667 // does not need to be loaded! The compiler must assume that
668 // the value of the unloaded class reference is null; if the code
669 // ever sees a non-null value, loading has occurred.
670 //
671 // This actually happens often enough to be annoying. If the
672 // compiler throws an uncommon trap at this bytecode, you can
673 // get an endless loop of recompilations, when all the code
674 // needs to do is load a series of null values. Also, a trap
675 // here can make an OSR entry point unreachable, triggering the
676 // assert on non_osr_block in ciTypeFlow::get_start_state.
677 // (See bug 4379915.)
678 do_null_assert(field_type->as_klass());
679 } else {
680 if (field->is_flattenable()) {
681 // A flattenable field is never null
682 field_type = outer()->mark_as_never_null(field_type);
683 }
684 push_translate(field_type);
685 }
686 }
687 }
688
689 // ------------------------------------------------------------------
690 // ciTypeFlow::StateVector::do_invoke
691 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
692 bool has_receiver) {
693 bool will_link;
694 ciSignature* declared_signature = NULL;
695 ciMethod* callee = str->get_method(will_link, &declared_signature);
696 assert(declared_signature != NULL, "cannot be null");
697 if (!will_link) {
698 // We weren't able to find the method.
699 if (str->cur_bc() == Bytecodes::_invokedynamic) {
700 trap(str, NULL,
701 Deoptimization::make_trap_request
702 (Deoptimization::Reason_uninitialized,
703 Deoptimization::Action_reinterpret));
704 } else {
705 ciKlass* unloaded_holder = callee->holder();
706 trap(str, unloaded_holder, str->get_method_holder_index());
707 }
708 } else {
709 // We are using the declared signature here because it might be
710 // different from the callee signature (Cf. invokedynamic and
711 // invokehandle).
712 ciSignatureStream sigstr(declared_signature);
713 const int arg_size = declared_signature->size();
714 const int stack_base = stack_size() - arg_size;
715 int i = 0;
716 for( ; !sigstr.at_return_type(); sigstr.next()) {
717 ciType* type = sigstr.type();
718 ciType* stack_type = type_at(stack(stack_base + i++));
719 // Do I want to check this type?
720 // assert(stack_type->is_subtype_of(type), "bad type for field value");
721 if (type->is_two_word()) {
722 ciType* stack_type2 = type_at(stack(stack_base + i++));
723 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
724 }
725 }
726 assert(arg_size == i, "must match");
727 for (int j = 0; j < arg_size; j++) {
728 pop();
729 }
730 if (has_receiver) {
731 // Check this?
732 pop_object();
733 }
734 assert(!sigstr.is_done(), "must have return type");
735 ciType* return_type = sigstr.type();
736 if (!return_type->is_void()) {
737 if (!return_type->is_loaded()) {
738 // As in do_getstatic(), generally speaking, we need the return type to
739 // be loaded if we are to do anything interesting with its value.
740 // We used to do this: trap(str, str->get_method_signature_index());
741 //
742 // We do not trap here since execution can get past this invoke if
743 // the return value is null. As long as the value is null, the class
744 // does not need to be loaded! The compiler must assume that
745 // the value of the unloaded class reference is null; if the code
746 // ever sees a non-null value, loading has occurred.
747 //
748 // See do_getstatic() for similar explanation, as well as bug 4684993.
749 do_null_assert(return_type->as_klass());
750 } else {
751 if (sigstr.is_never_null()) {
752 return_type = outer()->mark_as_never_null(return_type);
753 }
754 push_translate(return_type);
755 }
756 }
757 }
758 }
759
760 // ------------------------------------------------------------------
761 // ciTypeFlow::StateVector::do_jsr
762 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
763 push(ciReturnAddress::make(str->next_bci()));
764 }
765
766 // ------------------------------------------------------------------
767 // ciTypeFlow::StateVector::do_ldc
768 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
769 ciConstant con = str->get_constant();
770 BasicType basic_type = con.basic_type();
771 if (basic_type == T_ILLEGAL) {
772 // OutOfMemoryError in the CI while loading constant
773 push_null();
774 outer()->record_failure("ldc did not link");
775 return;
776 }
777 if (basic_type == T_OBJECT || basic_type == T_VALUETYPE || basic_type == T_ARRAY) {
778 ciObject* obj = con.as_object();
779 if (obj->is_null_object()) {
780 push_null();
781 } else {
782 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
783 ciType* type = obj->klass();
784 if (type->is_valuetype()) {
785 type = outer()->mark_as_never_null(type);
786 }
787 push(type);
788 }
789 } else {
790 push_translate(ciType::make(basic_type));
791 }
792 }
793
794 // ------------------------------------------------------------------
795 // ciTypeFlow::StateVector::do_multianewarray
796 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
797 int dimensions = str->get_dimensions();
798 bool will_link;
799 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
800 if (!will_link) {
801 trap(str, array_klass, str->get_klass_index());
802 } else {
803 for (int i = 0; i < dimensions; i++) {
804 pop_int();
805 }
806 push_object(array_klass);
807 }
808 }
809
810 // ------------------------------------------------------------------
811 // ciTypeFlow::StateVector::do_new
812 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
813 bool will_link;
814 ciKlass* klass = str->get_klass(will_link);
815 if (!will_link || str->is_unresolved_klass()) {
816 trap(str, klass, str->get_klass_index());
817 } else {
818 push_object(klass);
819 }
820 }
821
822 // ------------------------------------------------------------------
823 // ciTypeFlow::StateVector::do_defaultvalue
824 void ciTypeFlow::StateVector::do_defaultvalue(ciBytecodeStream* str) {
825 bool will_link;
826 ciKlass* klass = str->get_klass(will_link);
827 if (!will_link) {
828 trap(str, klass, str->get_klass_index());
829 } else {
830 // The default value type is never null
831 push(outer()->mark_as_never_null(klass));
832 }
833 }
834
835 // ------------------------------------------------------------------
836 // ciTypeFlow::StateVector::do_withfield
837 void ciTypeFlow::StateVector::do_withfield(ciBytecodeStream* str) {
838 bool will_link;
839 ciField* field = str->get_field(will_link);
840 ciKlass* klass = field->holder();
841 if (!will_link) {
842 trap(str, klass, str->get_field_holder_index());
843 } else {
844 ciType* type = pop_value();
845 ciType* field_type = field->type();
846 assert(field_type->is_loaded(), "field type must be loaded");
847 if (field_type->is_two_word()) {
848 ciType* type2 = pop_value();
849 assert(type2->is_two_word(), "must be 2nd half");
850 assert(type == half_type(type2), "must be 2nd half");
851 }
852 pop_object();
853 // The newly created value type can never be null
854 push(outer()->mark_as_never_null(klass));
855 }
856 }
857
858 // ------------------------------------------------------------------
859 // ciTypeFlow::StateVector::do_newarray
860 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
861 pop_int();
862 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
863 push_object(klass);
864 }
865
866 // ------------------------------------------------------------------
867 // ciTypeFlow::StateVector::do_putfield
868 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
869 do_putstatic(str);
870 if (_trap_bci != -1) return; // unloaded field holder, etc.
871 // could add assert here for type of object.
872 pop_object();
873 }
874
875 // ------------------------------------------------------------------
876 // ciTypeFlow::StateVector::do_putstatic
877 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
878 bool will_link;
879 ciField* field = str->get_field(will_link);
880 if (!will_link) {
881 trap(str, field->holder(), str->get_field_holder_index());
882 } else {
883 ciType* field_type = field->type();
884 ciType* type = pop_value();
885 // Do I want to check this type?
886 // assert(type->is_subtype_of(field_type), "bad type for field value");
887 if (field_type->is_two_word()) {
888 ciType* type2 = pop_value();
889 assert(type2->is_two_word(), "must be 2nd half");
890 assert(type == half_type(type2), "must be 2nd half");
891 }
892 }
893 }
894
895 // ------------------------------------------------------------------
896 // ciTypeFlow::StateVector::do_ret
897 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
898 Cell index = local(str->get_index());
899
900 ciType* address = type_at(index);
901 assert(address->is_return_address(), "bad return address");
902 set_type_at(index, bottom_type());
903 }
904
905 // ------------------------------------------------------------------
906 // ciTypeFlow::StateVector::trap
907 //
908 // Stop interpretation of this path with a trap.
909 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
910 _trap_bci = str->cur_bci();
911 _trap_index = index;
912
913 // Log information about this trap:
914 CompileLog* log = outer()->env()->log();
915 if (log != NULL) {
916 int mid = log->identify(outer()->method());
917 int kid = (klass == NULL)? -1: log->identify(klass);
918 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
919 char buf[100];
920 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
921 index));
922 if (kid >= 0)
923 log->print(" klass='%d'", kid);
924 log->end_elem();
925 }
926 }
927
928 // ------------------------------------------------------------------
929 // ciTypeFlow::StateVector::do_null_assert
930 // Corresponds to graphKit::do_null_assert.
931 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
932 if (unloaded_klass->is_loaded()) {
933 // We failed to link, but we can still compute with this class,
934 // since it is loaded somewhere. The compiler will uncommon_trap
935 // if the object is not null, but the typeflow pass can not assume
936 // that the object will be null, otherwise it may incorrectly tell
937 // the parser that an object is known to be null. 4761344, 4807707
938 push_object(unloaded_klass);
939 } else {
940 // The class is not loaded anywhere. It is safe to model the
941 // null in the typestates, because we can compile in a null check
942 // which will deoptimize us if someone manages to load the
943 // class later.
944 push_null();
945 }
946 }
947
948
949 // ------------------------------------------------------------------
950 // ciTypeFlow::StateVector::apply_one_bytecode
951 //
952 // Apply the effect of one bytecode to this StateVector
953 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
954 _trap_bci = -1;
955 _trap_index = 0;
956
957 if (CITraceTypeFlow) {
958 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
959 Bytecodes::name(str->cur_bc()));
960 }
961
962 switch(str->cur_bc()) {
963 case Bytecodes::_aaload: do_aload(str); break;
964
965 case Bytecodes::_aastore:
966 {
967 pop_object();
968 pop_int();
969 pop_objOrValueArray();
970 break;
971 }
972 case Bytecodes::_aconst_null:
973 {
974 push_null();
975 break;
976 }
977 case Bytecodes::_aload: load_local_object(str->get_index()); break;
978 case Bytecodes::_aload_0: load_local_object(0); break;
979 case Bytecodes::_aload_1: load_local_object(1); break;
980 case Bytecodes::_aload_2: load_local_object(2); break;
981 case Bytecodes::_aload_3: load_local_object(3); break;
982
983 case Bytecodes::_anewarray:
984 {
985 pop_int();
986 bool will_link;
987 ciKlass* element_klass = str->get_klass(will_link);
988 if (!will_link) {
989 trap(str, element_klass, str->get_klass_index());
990 } else {
991 push_object(ciArrayKlass::make(element_klass));
992 }
993 break;
994 }
995 case Bytecodes::_areturn:
996 case Bytecodes::_ifnonnull:
997 case Bytecodes::_ifnull:
998 {
999 pop_object();
1000 break;
1001 }
1002 case Bytecodes::_monitorenter:
1003 {
1004 pop_object();
1005 set_monitor_count(monitor_count() + 1);
1006 break;
1007 }
1008 case Bytecodes::_monitorexit:
1009 {
1010 pop_object();
1011 assert(monitor_count() > 0, "must be a monitor to exit from");
1012 set_monitor_count(monitor_count() - 1);
1013 break;
1014 }
1015 case Bytecodes::_arraylength:
1016 {
1017 pop_array();
1018 push_int();
1019 break;
1020 }
1021 case Bytecodes::_astore: store_local_object(str->get_index()); break;
1022 case Bytecodes::_astore_0: store_local_object(0); break;
1023 case Bytecodes::_astore_1: store_local_object(1); break;
1024 case Bytecodes::_astore_2: store_local_object(2); break;
1025 case Bytecodes::_astore_3: store_local_object(3); break;
1026
1027 case Bytecodes::_athrow:
1028 {
1029 NEEDS_CLEANUP;
1030 pop_object();
1031 break;
1032 }
1033 case Bytecodes::_baload:
1034 case Bytecodes::_caload:
1035 case Bytecodes::_iaload:
1036 case Bytecodes::_saload:
1037 {
1038 pop_int();
1039 ciTypeArrayKlass* array_klass = pop_typeArray();
1040 // Put assert here for right type?
1041 push_int();
1042 break;
1043 }
1044 case Bytecodes::_bastore:
1045 case Bytecodes::_castore:
1046 case Bytecodes::_iastore:
1047 case Bytecodes::_sastore:
1048 {
1049 pop_int();
1050 pop_int();
1051 pop_typeArray();
1052 // assert here?
1053 break;
1054 }
1055 case Bytecodes::_bipush:
1056 case Bytecodes::_iconst_m1:
1057 case Bytecodes::_iconst_0:
1058 case Bytecodes::_iconst_1:
1059 case Bytecodes::_iconst_2:
1060 case Bytecodes::_iconst_3:
1061 case Bytecodes::_iconst_4:
1062 case Bytecodes::_iconst_5:
1063 case Bytecodes::_sipush:
1064 {
1065 push_int();
1066 break;
1067 }
1068 case Bytecodes::_checkcast: do_checkcast(str); break;
1069
1070 case Bytecodes::_d2f:
1071 {
1072 pop_double();
1073 push_float();
1074 break;
1075 }
1076 case Bytecodes::_d2i:
1077 {
1078 pop_double();
1079 push_int();
1080 break;
1081 }
1082 case Bytecodes::_d2l:
1083 {
1084 pop_double();
1085 push_long();
1086 break;
1087 }
1088 case Bytecodes::_dadd:
1089 case Bytecodes::_ddiv:
1090 case Bytecodes::_dmul:
1091 case Bytecodes::_drem:
1092 case Bytecodes::_dsub:
1093 {
1094 pop_double();
1095 pop_double();
1096 push_double();
1097 break;
1098 }
1099 case Bytecodes::_daload:
1100 {
1101 pop_int();
1102 ciTypeArrayKlass* array_klass = pop_typeArray();
1103 // Put assert here for right type?
1104 push_double();
1105 break;
1106 }
1107 case Bytecodes::_dastore:
1108 {
1109 pop_double();
1110 pop_int();
1111 pop_typeArray();
1112 // assert here?
1113 break;
1114 }
1115 case Bytecodes::_dcmpg:
1116 case Bytecodes::_dcmpl:
1117 {
1118 pop_double();
1119 pop_double();
1120 push_int();
1121 break;
1122 }
1123 case Bytecodes::_dconst_0:
1124 case Bytecodes::_dconst_1:
1125 {
1126 push_double();
1127 break;
1128 }
1129 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1130 case Bytecodes::_dload_0: load_local_double(0); break;
1131 case Bytecodes::_dload_1: load_local_double(1); break;
1132 case Bytecodes::_dload_2: load_local_double(2); break;
1133 case Bytecodes::_dload_3: load_local_double(3); break;
1134
1135 case Bytecodes::_dneg:
1136 {
1137 pop_double();
1138 push_double();
1139 break;
1140 }
1141 case Bytecodes::_dreturn:
1142 {
1143 pop_double();
1144 break;
1145 }
1146 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1147 case Bytecodes::_dstore_0: store_local_double(0); break;
1148 case Bytecodes::_dstore_1: store_local_double(1); break;
1149 case Bytecodes::_dstore_2: store_local_double(2); break;
1150 case Bytecodes::_dstore_3: store_local_double(3); break;
1151
1152 case Bytecodes::_dup:
1153 {
1154 push(type_at_tos());
1155 break;
1156 }
1157 case Bytecodes::_dup_x1:
1158 {
1159 ciType* value1 = pop_value();
1160 ciType* value2 = pop_value();
1161 push(value1);
1162 push(value2);
1163 push(value1);
1164 break;
1165 }
1166 case Bytecodes::_dup_x2:
1167 {
1168 ciType* value1 = pop_value();
1169 ciType* value2 = pop_value();
1170 ciType* value3 = pop_value();
1171 push(value1);
1172 push(value3);
1173 push(value2);
1174 push(value1);
1175 break;
1176 }
1177 case Bytecodes::_dup2:
1178 {
1179 ciType* value1 = pop_value();
1180 ciType* value2 = pop_value();
1181 push(value2);
1182 push(value1);
1183 push(value2);
1184 push(value1);
1185 break;
1186 }
1187 case Bytecodes::_dup2_x1:
1188 {
1189 ciType* value1 = pop_value();
1190 ciType* value2 = pop_value();
1191 ciType* value3 = pop_value();
1192 push(value2);
1193 push(value1);
1194 push(value3);
1195 push(value2);
1196 push(value1);
1197 break;
1198 }
1199 case Bytecodes::_dup2_x2:
1200 {
1201 ciType* value1 = pop_value();
1202 ciType* value2 = pop_value();
1203 ciType* value3 = pop_value();
1204 ciType* value4 = pop_value();
1205 push(value2);
1206 push(value1);
1207 push(value4);
1208 push(value3);
1209 push(value2);
1210 push(value1);
1211 break;
1212 }
1213 case Bytecodes::_f2d:
1214 {
1215 pop_float();
1216 push_double();
1217 break;
1218 }
1219 case Bytecodes::_f2i:
1220 {
1221 pop_float();
1222 push_int();
1223 break;
1224 }
1225 case Bytecodes::_f2l:
1226 {
1227 pop_float();
1228 push_long();
1229 break;
1230 }
1231 case Bytecodes::_fadd:
1232 case Bytecodes::_fdiv:
1233 case Bytecodes::_fmul:
1234 case Bytecodes::_frem:
1235 case Bytecodes::_fsub:
1236 {
1237 pop_float();
1238 pop_float();
1239 push_float();
1240 break;
1241 }
1242 case Bytecodes::_faload:
1243 {
1244 pop_int();
1245 ciTypeArrayKlass* array_klass = pop_typeArray();
1246 // Put assert here.
1247 push_float();
1248 break;
1249 }
1250 case Bytecodes::_fastore:
1251 {
1252 pop_float();
1253 pop_int();
1254 ciTypeArrayKlass* array_klass = pop_typeArray();
1255 // Put assert here.
1256 break;
1257 }
1258 case Bytecodes::_fcmpg:
1259 case Bytecodes::_fcmpl:
1260 {
1261 pop_float();
1262 pop_float();
1263 push_int();
1264 break;
1265 }
1266 case Bytecodes::_fconst_0:
1267 case Bytecodes::_fconst_1:
1268 case Bytecodes::_fconst_2:
1269 {
1270 push_float();
1271 break;
1272 }
1273 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1274 case Bytecodes::_fload_0: load_local_float(0); break;
1275 case Bytecodes::_fload_1: load_local_float(1); break;
1276 case Bytecodes::_fload_2: load_local_float(2); break;
1277 case Bytecodes::_fload_3: load_local_float(3); break;
1278
1279 case Bytecodes::_fneg:
1280 {
1281 pop_float();
1282 push_float();
1283 break;
1284 }
1285 case Bytecodes::_freturn:
1286 {
1287 pop_float();
1288 break;
1289 }
1290 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1291 case Bytecodes::_fstore_0: store_local_float(0); break;
1292 case Bytecodes::_fstore_1: store_local_float(1); break;
1293 case Bytecodes::_fstore_2: store_local_float(2); break;
1294 case Bytecodes::_fstore_3: store_local_float(3); break;
1295
1296 case Bytecodes::_getfield: do_getfield(str); break;
1297 case Bytecodes::_getstatic: do_getstatic(str); break;
1298
1299 case Bytecodes::_goto:
1300 case Bytecodes::_goto_w:
1301 case Bytecodes::_nop:
1302 case Bytecodes::_return:
1303 {
1304 // do nothing.
1305 break;
1306 }
1307 case Bytecodes::_i2b:
1308 case Bytecodes::_i2c:
1309 case Bytecodes::_i2s:
1310 case Bytecodes::_ineg:
1311 {
1312 pop_int();
1313 push_int();
1314 break;
1315 }
1316 case Bytecodes::_i2d:
1317 {
1318 pop_int();
1319 push_double();
1320 break;
1321 }
1322 case Bytecodes::_i2f:
1323 {
1324 pop_int();
1325 push_float();
1326 break;
1327 }
1328 case Bytecodes::_i2l:
1329 {
1330 pop_int();
1331 push_long();
1332 break;
1333 }
1334 case Bytecodes::_iadd:
1335 case Bytecodes::_iand:
1336 case Bytecodes::_idiv:
1337 case Bytecodes::_imul:
1338 case Bytecodes::_ior:
1339 case Bytecodes::_irem:
1340 case Bytecodes::_ishl:
1341 case Bytecodes::_ishr:
1342 case Bytecodes::_isub:
1343 case Bytecodes::_iushr:
1344 case Bytecodes::_ixor:
1345 {
1346 pop_int();
1347 pop_int();
1348 push_int();
1349 break;
1350 }
1351 case Bytecodes::_if_acmpeq:
1352 case Bytecodes::_if_acmpne:
1353 {
1354 pop_object();
1355 pop_object();
1356 break;
1357 }
1358 case Bytecodes::_if_icmpeq:
1359 case Bytecodes::_if_icmpge:
1360 case Bytecodes::_if_icmpgt:
1361 case Bytecodes::_if_icmple:
1362 case Bytecodes::_if_icmplt:
1363 case Bytecodes::_if_icmpne:
1364 {
1365 pop_int();
1366 pop_int();
1367 break;
1368 }
1369 case Bytecodes::_ifeq:
1370 case Bytecodes::_ifle:
1371 case Bytecodes::_iflt:
1372 case Bytecodes::_ifge:
1373 case Bytecodes::_ifgt:
1374 case Bytecodes::_ifne:
1375 case Bytecodes::_ireturn:
1376 case Bytecodes::_lookupswitch:
1377 case Bytecodes::_tableswitch:
1378 {
1379 pop_int();
1380 break;
1381 }
1382 case Bytecodes::_iinc:
1383 {
1384 int lnum = str->get_index();
1385 check_int(local(lnum));
1386 store_to_local(lnum);
1387 break;
1388 }
1389 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1390 case Bytecodes::_iload_0: load_local_int(0); break;
1391 case Bytecodes::_iload_1: load_local_int(1); break;
1392 case Bytecodes::_iload_2: load_local_int(2); break;
1393 case Bytecodes::_iload_3: load_local_int(3); break;
1394
1395 case Bytecodes::_instanceof:
1396 {
1397 // Check for uncommon trap:
1398 do_checkcast(str);
1399 pop_object();
1400 push_int();
1401 break;
1402 }
1403 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1404 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1405 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1406 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1407 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1408
1409 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1410 case Bytecodes::_istore_0: store_local_int(0); break;
1411 case Bytecodes::_istore_1: store_local_int(1); break;
1412 case Bytecodes::_istore_2: store_local_int(2); break;
1413 case Bytecodes::_istore_3: store_local_int(3); break;
1414
1415 case Bytecodes::_jsr:
1416 case Bytecodes::_jsr_w: do_jsr(str); break;
1417
1418 case Bytecodes::_l2d:
1419 {
1420 pop_long();
1421 push_double();
1422 break;
1423 }
1424 case Bytecodes::_l2f:
1425 {
1426 pop_long();
1427 push_float();
1428 break;
1429 }
1430 case Bytecodes::_l2i:
1431 {
1432 pop_long();
1433 push_int();
1434 break;
1435 }
1436 case Bytecodes::_ladd:
1437 case Bytecodes::_land:
1438 case Bytecodes::_ldiv:
1439 case Bytecodes::_lmul:
1440 case Bytecodes::_lor:
1441 case Bytecodes::_lrem:
1442 case Bytecodes::_lsub:
1443 case Bytecodes::_lxor:
1444 {
1445 pop_long();
1446 pop_long();
1447 push_long();
1448 break;
1449 }
1450 case Bytecodes::_laload:
1451 {
1452 pop_int();
1453 ciTypeArrayKlass* array_klass = pop_typeArray();
1454 // Put assert here for right type?
1455 push_long();
1456 break;
1457 }
1458 case Bytecodes::_lastore:
1459 {
1460 pop_long();
1461 pop_int();
1462 pop_typeArray();
1463 // assert here?
1464 break;
1465 }
1466 case Bytecodes::_lcmp:
1467 {
1468 pop_long();
1469 pop_long();
1470 push_int();
1471 break;
1472 }
1473 case Bytecodes::_lconst_0:
1474 case Bytecodes::_lconst_1:
1475 {
1476 push_long();
1477 break;
1478 }
1479 case Bytecodes::_ldc:
1480 case Bytecodes::_ldc_w:
1481 case Bytecodes::_ldc2_w:
1482 {
1483 do_ldc(str);
1484 break;
1485 }
1486
1487 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1488 case Bytecodes::_lload_0: load_local_long(0); break;
1489 case Bytecodes::_lload_1: load_local_long(1); break;
1490 case Bytecodes::_lload_2: load_local_long(2); break;
1491 case Bytecodes::_lload_3: load_local_long(3); break;
1492
1493 case Bytecodes::_lneg:
1494 {
1495 pop_long();
1496 push_long();
1497 break;
1498 }
1499 case Bytecodes::_lreturn:
1500 {
1501 pop_long();
1502 break;
1503 }
1504 case Bytecodes::_lshl:
1505 case Bytecodes::_lshr:
1506 case Bytecodes::_lushr:
1507 {
1508 pop_int();
1509 pop_long();
1510 push_long();
1511 break;
1512 }
1513 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1514 case Bytecodes::_lstore_0: store_local_long(0); break;
1515 case Bytecodes::_lstore_1: store_local_long(1); break;
1516 case Bytecodes::_lstore_2: store_local_long(2); break;
1517 case Bytecodes::_lstore_3: store_local_long(3); break;
1518
1519 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1520
1521 case Bytecodes::_new: do_new(str); break;
1522
1523 case Bytecodes::_defaultvalue: do_defaultvalue(str); break;
1524 case Bytecodes::_withfield: do_withfield(str); break;
1525
1526 case Bytecodes::_newarray: do_newarray(str); break;
1527
1528 case Bytecodes::_pop:
1529 {
1530 pop();
1531 break;
1532 }
1533 case Bytecodes::_pop2:
1534 {
1535 pop();
1536 pop();
1537 break;
1538 }
1539
1540 case Bytecodes::_putfield: do_putfield(str); break;
1541 case Bytecodes::_putstatic: do_putstatic(str); break;
1542
1543 case Bytecodes::_ret: do_ret(str); break;
1544
1545 case Bytecodes::_swap:
1546 {
1547 ciType* value1 = pop_value();
1548 ciType* value2 = pop_value();
1549 push(value1);
1550 push(value2);
1551 break;
1552 }
1553
1554 case Bytecodes::_wide:
1555 default:
1556 {
1557 // The iterator should skip this.
1558 ShouldNotReachHere();
1559 break;
1560 }
1561 }
1562
1563 if (CITraceTypeFlow) {
1564 print_on(tty);
1565 }
1566
1567 return (_trap_bci != -1);
1568 }
1569
1570 #ifndef PRODUCT
1571 // ------------------------------------------------------------------
1572 // ciTypeFlow::StateVector::print_cell_on
1573 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1574 ciType* type = type_at(c);
1575 if (type == top_type()) {
1576 st->print("top");
1577 } else if (type == bottom_type()) {
1578 st->print("bottom");
1579 } else if (type == null_type()) {
1580 st->print("null");
1581 } else if (type == long2_type()) {
1582 st->print("long2");
1583 } else if (type == double2_type()) {
1584 st->print("double2");
1585 } else if (is_int(type)) {
1586 st->print("int");
1587 } else if (is_long(type)) {
1588 st->print("long");
1589 } else if (is_float(type)) {
1590 st->print("float");
1591 } else if (is_double(type)) {
1592 st->print("double");
1593 } else if (type->is_return_address()) {
1594 st->print("address(%d)", type->as_return_address()->bci());
1595 } else {
1596 if (type->is_klass()) {
1597 type->as_klass()->name()->print_symbol_on(st);
1598 } else {
1599 st->print("UNEXPECTED TYPE");
1600 type->print();
1601 }
1602 }
1603 }
1604
1605 // ------------------------------------------------------------------
1606 // ciTypeFlow::StateVector::print_on
1607 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1608 int num_locals = _outer->max_locals();
1609 int num_stack = stack_size();
1610 int num_monitors = monitor_count();
1611 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1612 if (num_stack >= 0) {
1613 int i;
1614 for (i = 0; i < num_locals; i++) {
1615 st->print(" local %2d : ", i);
1616 print_cell_on(st, local(i));
1617 st->cr();
1618 }
1619 for (i = 0; i < num_stack; i++) {
1620 st->print(" stack %2d : ", i);
1621 print_cell_on(st, stack(i));
1622 st->cr();
1623 }
1624 }
1625 }
1626 #endif
1627
1628
1629 // ------------------------------------------------------------------
1630 // ciTypeFlow::SuccIter::next
1631 //
1632 void ciTypeFlow::SuccIter::next() {
1633 int succ_ct = _pred->successors()->length();
1634 int next = _index + 1;
1635 if (next < succ_ct) {
1636 _index = next;
1637 _succ = _pred->successors()->at(next);
1638 return;
1639 }
1640 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1641 // Do not compile any code for unloaded exception types.
1642 // Following compiler passes are responsible for doing this also.
1643 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1644 if (exception_klass->is_loaded()) {
1645 _index = next;
1646 _succ = _pred->exceptions()->at(i);
1647 return;
1648 }
1649 next++;
1650 }
1651 _index = -1;
1652 _succ = NULL;
1653 }
1654
1655 // ------------------------------------------------------------------
1656 // ciTypeFlow::SuccIter::set_succ
1657 //
1658 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1659 int succ_ct = _pred->successors()->length();
1660 if (_index < succ_ct) {
1661 _pred->successors()->at_put(_index, succ);
1662 } else {
1663 int idx = _index - succ_ct;
1664 _pred->exceptions()->at_put(idx, succ);
1665 }
1666 }
1667
1668 // ciTypeFlow::Block
1669 //
1670 // A basic block.
1671
1672 // ------------------------------------------------------------------
1673 // ciTypeFlow::Block::Block
1674 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1675 ciBlock *ciblk,
1676 ciTypeFlow::JsrSet* jsrs) {
1677 _ciblock = ciblk;
1678 _exceptions = NULL;
1679 _exc_klasses = NULL;
1680 _successors = NULL;
1681 _predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
1682 _state = new (outer->arena()) StateVector(outer);
1683 JsrSet* new_jsrs =
1684 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1685 jsrs->copy_into(new_jsrs);
1686 _jsrs = new_jsrs;
1687 _next = NULL;
1688 _on_work_list = false;
1689 _backedge_copy = false;
1690 _has_monitorenter = false;
1691 _trap_bci = -1;
1692 _trap_index = 0;
1693 df_init();
1694
1695 if (CITraceTypeFlow) {
1696 tty->print_cr(">> Created new block");
1697 print_on(tty);
1698 }
1699
1700 assert(this->outer() == outer, "outer link set up");
1701 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1702 }
1703
1704 // ------------------------------------------------------------------
1705 // ciTypeFlow::Block::df_init
1706 void ciTypeFlow::Block::df_init() {
1707 _pre_order = -1; assert(!has_pre_order(), "");
1708 _post_order = -1; assert(!has_post_order(), "");
1709 _loop = NULL;
1710 _irreducible_entry = false;
1711 _rpo_next = NULL;
1712 }
1713
1714 // ------------------------------------------------------------------
1715 // ciTypeFlow::Block::successors
1716 //
1717 // Get the successors for this Block.
1718 GrowableArray<ciTypeFlow::Block*>*
1719 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1720 ciTypeFlow::StateVector* state,
1721 ciTypeFlow::JsrSet* jsrs) {
1722 if (_successors == NULL) {
1723 if (CITraceTypeFlow) {
1724 tty->print(">> Computing successors for block ");
1725 print_value_on(tty);
1726 tty->cr();
1727 }
1728
1729 ciTypeFlow* analyzer = outer();
1730 Arena* arena = analyzer->arena();
1731 Block* block = NULL;
1732 bool has_successor = !has_trap() &&
1733 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1734 if (!has_successor) {
1735 _successors =
1736 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1737 // No successors
1738 } else if (control() == ciBlock::fall_through_bci) {
1739 assert(str->cur_bci() == limit(), "bad block end");
1740 // This block simply falls through to the next.
1741 _successors =
1742 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1743
1744 Block* block = analyzer->block_at(limit(), _jsrs);
1745 assert(_successors->length() == FALL_THROUGH, "");
1746 _successors->append(block);
1747 } else {
1748 int current_bci = str->cur_bci();
1749 int next_bci = str->next_bci();
1750 int branch_bci = -1;
1751 Block* target = NULL;
1752 assert(str->next_bci() == limit(), "bad block end");
1753 // This block is not a simple fall-though. Interpret
1754 // the current bytecode to find our successors.
1755 switch (str->cur_bc()) {
1756 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1757 case Bytecodes::_iflt: case Bytecodes::_ifge:
1758 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1759 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1760 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1761 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1762 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1763 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1764 // Our successors are the branch target and the next bci.
1765 branch_bci = str->get_dest();
1766 _successors =
1767 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1768 assert(_successors->length() == IF_NOT_TAKEN, "");
1769 _successors->append(analyzer->block_at(next_bci, jsrs));
1770 assert(_successors->length() == IF_TAKEN, "");
1771 _successors->append(analyzer->block_at(branch_bci, jsrs));
1772 break;
1773
1774 case Bytecodes::_goto:
1775 branch_bci = str->get_dest();
1776 _successors =
1777 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1778 assert(_successors->length() == GOTO_TARGET, "");
1779 _successors->append(analyzer->block_at(branch_bci, jsrs));
1780 break;
1781
1782 case Bytecodes::_jsr:
1783 branch_bci = str->get_dest();
1784 _successors =
1785 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1786 assert(_successors->length() == GOTO_TARGET, "");
1787 _successors->append(analyzer->block_at(branch_bci, jsrs));
1788 break;
1789
1790 case Bytecodes::_goto_w:
1791 case Bytecodes::_jsr_w:
1792 _successors =
1793 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1794 assert(_successors->length() == GOTO_TARGET, "");
1795 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1796 break;
1797
1798 case Bytecodes::_tableswitch: {
1799 Bytecode_tableswitch tableswitch(str);
1800
1801 int len = tableswitch.length();
1802 _successors =
1803 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1804 int bci = current_bci + tableswitch.default_offset();
1805 Block* block = analyzer->block_at(bci, jsrs);
1806 assert(_successors->length() == SWITCH_DEFAULT, "");
1807 _successors->append(block);
1808 while (--len >= 0) {
1809 int bci = current_bci + tableswitch.dest_offset_at(len);
1810 block = analyzer->block_at(bci, jsrs);
1811 assert(_successors->length() >= SWITCH_CASES, "");
1812 _successors->append_if_missing(block);
1813 }
1814 break;
1815 }
1816
1817 case Bytecodes::_lookupswitch: {
1818 Bytecode_lookupswitch lookupswitch(str);
1819
1820 int npairs = lookupswitch.number_of_pairs();
1821 _successors =
1822 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1823 int bci = current_bci + lookupswitch.default_offset();
1824 Block* block = analyzer->block_at(bci, jsrs);
1825 assert(_successors->length() == SWITCH_DEFAULT, "");
1826 _successors->append(block);
1827 while(--npairs >= 0) {
1828 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1829 int bci = current_bci + pair.offset();
1830 Block* block = analyzer->block_at(bci, jsrs);
1831 assert(_successors->length() >= SWITCH_CASES, "");
1832 _successors->append_if_missing(block);
1833 }
1834 break;
1835 }
1836
1837 case Bytecodes::_athrow:
1838 case Bytecodes::_ireturn:
1839 case Bytecodes::_lreturn:
1840 case Bytecodes::_freturn:
1841 case Bytecodes::_dreturn:
1842 case Bytecodes::_areturn:
1843 case Bytecodes::_return:
1844 _successors =
1845 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1846 // No successors
1847 break;
1848
1849 case Bytecodes::_ret: {
1850 _successors =
1851 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1852
1853 Cell local = state->local(str->get_index());
1854 ciType* return_address = state->type_at(local);
1855 assert(return_address->is_return_address(), "verify: wrong type");
1856 int bci = return_address->as_return_address()->bci();
1857 assert(_successors->length() == GOTO_TARGET, "");
1858 _successors->append(analyzer->block_at(bci, jsrs));
1859 break;
1860 }
1861
1862 case Bytecodes::_wide:
1863 default:
1864 ShouldNotReachHere();
1865 break;
1866 }
1867 }
1868
1869 // Set predecessor information
1870 for (int i = 0; i < _successors->length(); i++) {
1871 Block* block = _successors->at(i);
1872 block->predecessors()->append(this);
1873 }
1874 }
1875 return _successors;
1876 }
1877
1878 // ------------------------------------------------------------------
1879 // ciTypeFlow::Block:compute_exceptions
1880 //
1881 // Compute the exceptional successors and types for this Block.
1882 void ciTypeFlow::Block::compute_exceptions() {
1883 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1884
1885 if (CITraceTypeFlow) {
1886 tty->print(">> Computing exceptions for block ");
1887 print_value_on(tty);
1888 tty->cr();
1889 }
1890
1891 ciTypeFlow* analyzer = outer();
1892 Arena* arena = analyzer->arena();
1893
1894 // Any bci in the block will do.
1895 ciExceptionHandlerStream str(analyzer->method(), start());
1896
1897 // Allocate our growable arrays.
1898 int exc_count = str.count();
1899 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1900 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1901 0, NULL);
1902
1903 for ( ; !str.is_done(); str.next()) {
1904 ciExceptionHandler* handler = str.handler();
1905 int bci = handler->handler_bci();
1906 ciInstanceKlass* klass = NULL;
1907 if (bci == -1) {
1908 // There is no catch all. It is possible to exit the method.
1909 break;
1910 }
1911 if (handler->is_catch_all()) {
1912 klass = analyzer->env()->Throwable_klass();
1913 } else {
1914 klass = handler->catch_klass();
1915 }
1916 Block* block = analyzer->block_at(bci, _jsrs);
1917 _exceptions->append(block);
1918 block->predecessors()->append(this);
1919 _exc_klasses->append(klass);
1920 }
1921 }
1922
1923 // ------------------------------------------------------------------
1924 // ciTypeFlow::Block::set_backedge_copy
1925 // Use this only to make a pre-existing public block into a backedge copy.
1926 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1927 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1928 _backedge_copy = z;
1929 }
1930
1931 // ------------------------------------------------------------------
1932 // ciTypeFlow::Block::is_clonable_exit
1933 //
1934 // At most 2 normal successors, one of which continues looping,
1935 // and all exceptional successors must exit.
1936 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1937 int normal_cnt = 0;
1938 int in_loop_cnt = 0;
1939 for (SuccIter iter(this); !iter.done(); iter.next()) {
1940 Block* succ = iter.succ();
1941 if (iter.is_normal_ctrl()) {
1942 if (++normal_cnt > 2) return false;
1943 if (lp->contains(succ->loop())) {
1944 if (++in_loop_cnt > 1) return false;
1945 }
1946 } else {
1947 if (lp->contains(succ->loop())) return false;
1948 }
1949 }
1950 return in_loop_cnt == 1;
1951 }
1952
1953 // ------------------------------------------------------------------
1954 // ciTypeFlow::Block::looping_succ
1955 //
1956 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1957 assert(successors()->length() <= 2, "at most 2 normal successors");
1958 for (SuccIter iter(this); !iter.done(); iter.next()) {
1959 Block* succ = iter.succ();
1960 if (lp->contains(succ->loop())) {
1961 return succ;
1962 }
1963 }
1964 return NULL;
1965 }
1966
1967 #ifndef PRODUCT
1968 // ------------------------------------------------------------------
1969 // ciTypeFlow::Block::print_value_on
1970 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1971 if (has_pre_order()) st->print("#%-2d ", pre_order());
1972 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1973 st->print("[%d - %d)", start(), limit());
1974 if (is_loop_head()) st->print(" lphd");
1975 if (is_irreducible_entry()) st->print(" irred");
1976 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1977 if (is_backedge_copy()) st->print("/backedge_copy");
1978 }
1979
1980 // ------------------------------------------------------------------
1981 // ciTypeFlow::Block::print_on
1982 void ciTypeFlow::Block::print_on(outputStream* st) const {
1983 if ((Verbose || WizardMode) && (limit() >= 0)) {
1984 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1985 outer()->method()->print_codes_on(start(), limit(), st);
1986 }
1987 st->print_cr(" ==================================================== ");
1988 st->print (" ");
1989 print_value_on(st);
1990 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1991 if (loop() && loop()->parent() != NULL) {
1992 st->print(" loops:");
1993 Loop* lp = loop();
1994 do {
1995 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1996 if (lp->is_irreducible()) st->print("(ir)");
1997 lp = lp->parent();
1998 } while (lp->parent() != NULL);
1999 }
2000 st->cr();
2001 _state->print_on(st);
2002 if (_successors == NULL) {
2003 st->print_cr(" No successor information");
2004 } else {
2005 int num_successors = _successors->length();
2006 st->print_cr(" Successors : %d", num_successors);
2007 for (int i = 0; i < num_successors; i++) {
2008 Block* successor = _successors->at(i);
2009 st->print(" ");
2010 successor->print_value_on(st);
2011 st->cr();
2012 }
2013 }
2014 if (_predecessors == NULL) {
2015 st->print_cr(" No predecessor information");
2016 } else {
2017 int num_predecessors = _predecessors->length();
2018 st->print_cr(" Predecessors : %d", num_predecessors);
2019 for (int i = 0; i < num_predecessors; i++) {
2020 Block* predecessor = _predecessors->at(i);
2021 st->print(" ");
2022 predecessor->print_value_on(st);
2023 st->cr();
2024 }
2025 }
2026 if (_exceptions == NULL) {
2027 st->print_cr(" No exception information");
2028 } else {
2029 int num_exceptions = _exceptions->length();
2030 st->print_cr(" Exceptions : %d", num_exceptions);
2031 for (int i = 0; i < num_exceptions; i++) {
2032 Block* exc_succ = _exceptions->at(i);
2033 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
2034 st->print(" ");
2035 exc_succ->print_value_on(st);
2036 st->print(" -- ");
2037 exc_klass->name()->print_symbol_on(st);
2038 st->cr();
2039 }
2040 }
2041 if (has_trap()) {
2042 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2043 }
2044 st->print_cr(" ==================================================== ");
2045 }
2046 #endif
2047
2048 #ifndef PRODUCT
2049 // ------------------------------------------------------------------
2050 // ciTypeFlow::LocalSet::print_on
2051 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2052 st->print("{");
2053 for (int i = 0; i < max; i++) {
2054 if (test(i)) st->print(" %d", i);
2055 }
2056 if (limit > max) {
2057 st->print(" %d..%d ", max, limit);
2058 }
2059 st->print(" }");
2060 }
2061 #endif
2062
2063 // ciTypeFlow
2064 //
2065 // This is a pass over the bytecodes which computes the following:
2066 // basic block structure
2067 // interpreter type-states (a la the verifier)
2068
2069 // ------------------------------------------------------------------
2070 // ciTypeFlow::ciTypeFlow
2071 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2072 _env = env;
2073 _method = method;
2074 _methodBlocks = method->get_method_blocks();
2075 _max_locals = method->max_locals();
2076 _max_stack = method->max_stack();
2077 _code_size = method->code_size();
2078 _has_irreducible_entry = false;
2079 _osr_bci = osr_bci;
2080 _failure_reason = NULL;
2081 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2082 _work_list = NULL;
2083
2084 _ciblock_count = _methodBlocks->num_blocks();
2085 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
2086 for (int i = 0; i < _ciblock_count; i++) {
2087 _idx_to_blocklist[i] = NULL;
2088 }
2089 _block_map = NULL; // until all blocks are seen
2090 _jsr_count = 0;
2091 _jsr_records = NULL;
2092 }
2093
2094 // ------------------------------------------------------------------
2095 // ciTypeFlow::work_list_next
2096 //
2097 // Get the next basic block from our work list.
2098 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2099 assert(!work_list_empty(), "work list must not be empty");
2100 Block* next_block = _work_list;
2101 _work_list = next_block->next();
2102 next_block->set_next(NULL);
2103 next_block->set_on_work_list(false);
2104 return next_block;
2105 }
2106
2107 // ------------------------------------------------------------------
2108 // ciTypeFlow::add_to_work_list
2109 //
2110 // Add a basic block to our work list.
2111 // List is sorted by decreasing postorder sort (same as increasing RPO)
2112 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2113 assert(!block->is_on_work_list(), "must not already be on work list");
2114
2115 if (CITraceTypeFlow) {
2116 tty->print(">> Adding block ");
2117 block->print_value_on(tty);
2118 tty->print_cr(" to the work list : ");
2119 }
2120
2121 block->set_on_work_list(true);
2122
2123 // decreasing post order sort
2124
2125 Block* prev = NULL;
2126 Block* current = _work_list;
2127 int po = block->post_order();
2128 while (current != NULL) {
2129 if (!current->has_post_order() || po > current->post_order())
2130 break;
2131 prev = current;
2132 current = current->next();
2133 }
2134 if (prev == NULL) {
2135 block->set_next(_work_list);
2136 _work_list = block;
2137 } else {
2138 block->set_next(current);
2139 prev->set_next(block);
2140 }
2141
2142 if (CITraceTypeFlow) {
2143 tty->cr();
2144 }
2145 }
2146
2147 // ------------------------------------------------------------------
2148 // ciTypeFlow::block_at
2149 //
2150 // Return the block beginning at bci which has a JsrSet compatible
2151 // with jsrs.
2152 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2153 // First find the right ciBlock.
2154 if (CITraceTypeFlow) {
2155 tty->print(">> Requesting block for %d/", bci);
2156 jsrs->print_on(tty);
2157 tty->cr();
2158 }
2159
2160 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2161 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2162 Block* block = get_block_for(ciblk->index(), jsrs, option);
2163
2164 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2165
2166 if (CITraceTypeFlow) {
2167 if (block != NULL) {
2168 tty->print(">> Found block ");
2169 block->print_value_on(tty);
2170 tty->cr();
2171 } else {
2172 tty->print_cr(">> No such block.");
2173 }
2174 }
2175
2176 return block;
2177 }
2178
2179 // ------------------------------------------------------------------
2180 // ciTypeFlow::make_jsr_record
2181 //
2182 // Make a JsrRecord for a given (entry, return) pair, if such a record
2183 // does not already exist.
2184 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2185 int return_address) {
2186 if (_jsr_records == NULL) {
2187 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2188 _jsr_count,
2189 0,
2190 NULL);
2191 }
2192 JsrRecord* record = NULL;
2193 int len = _jsr_records->length();
2194 for (int i = 0; i < len; i++) {
2195 JsrRecord* record = _jsr_records->at(i);
2196 if (record->entry_address() == entry_address &&
2197 record->return_address() == return_address) {
2198 return record;
2199 }
2200 }
2201
2202 record = new (arena()) JsrRecord(entry_address, return_address);
2203 _jsr_records->append(record);
2204 return record;
2205 }
2206
2207 // ------------------------------------------------------------------
2208 // ciTypeFlow::flow_exceptions
2209 //
2210 // Merge the current state into all exceptional successors at the
2211 // current point in the code.
2212 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2213 GrowableArray<ciInstanceKlass*>* exc_klasses,
2214 ciTypeFlow::StateVector* state) {
2215 int len = exceptions->length();
2216 assert(exc_klasses->length() == len, "must have same length");
2217 for (int i = 0; i < len; i++) {
2218 Block* block = exceptions->at(i);
2219 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2220
2221 if (!exception_klass->is_loaded()) {
2222 // Do not compile any code for unloaded exception types.
2223 // Following compiler passes are responsible for doing this also.
2224 continue;
2225 }
2226
2227 if (block->meet_exception(exception_klass, state)) {
2228 // Block was modified and has PO. Add it to the work list.
2229 if (block->has_post_order() &&
2230 !block->is_on_work_list()) {
2231 add_to_work_list(block);
2232 }
2233 }
2234 }
2235 }
2236
2237 // ------------------------------------------------------------------
2238 // ciTypeFlow::flow_successors
2239 //
2240 // Merge the current state into all successors at the current point
2241 // in the code.
2242 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2243 ciTypeFlow::StateVector* state) {
2244 int len = successors->length();
2245 for (int i = 0; i < len; i++) {
2246 Block* block = successors->at(i);
2247 if (block->meet(state)) {
2248 // Block was modified and has PO. Add it to the work list.
2249 if (block->has_post_order() &&
2250 !block->is_on_work_list()) {
2251 add_to_work_list(block);
2252 }
2253 }
2254 }
2255 }
2256
2257 // ------------------------------------------------------------------
2258 // ciTypeFlow::can_trap
2259 //
2260 // Tells if a given instruction is able to generate an exception edge.
2261 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2262 // Cf. GenerateOopMap::do_exception_edge.
2263 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2264
2265 switch (str.cur_bc()) {
2266 // %%% FIXME: ldc of Class can generate an exception
2267 case Bytecodes::_ldc:
2268 case Bytecodes::_ldc_w:
2269 case Bytecodes::_ldc2_w:
2270 case Bytecodes::_aload_0:
2271 // These bytecodes can trap for rewriting. We need to assume that
2272 // they do not throw exceptions to make the monitor analysis work.
2273 return false;
2274
2275 case Bytecodes::_ireturn:
2276 case Bytecodes::_lreturn:
2277 case Bytecodes::_freturn:
2278 case Bytecodes::_dreturn:
2279 case Bytecodes::_areturn:
2280 case Bytecodes::_return:
2281 // We can assume the monitor stack is empty in this analysis.
2282 return false;
2283
2284 case Bytecodes::_monitorexit:
2285 // We can assume monitors are matched in this analysis.
2286 return false;
2287
2288 default:
2289 return true;
2290 }
2291 }
2292
2293 // ------------------------------------------------------------------
2294 // ciTypeFlow::clone_loop_heads
2295 //
2296 // Clone the loop heads
2297 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2298 bool rslt = false;
2299 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2300 lp = iter.current();
2301 Block* head = lp->head();
2302 if (lp == loop_tree_root() ||
2303 lp->is_irreducible() ||
2304 !head->is_clonable_exit(lp))
2305 continue;
2306
2307 // Avoid BoxLock merge.
2308 if (EliminateNestedLocks && head->has_monitorenter())
2309 continue;
2310
2311 // check not already cloned
2312 if (head->backedge_copy_count() != 0)
2313 continue;
2314
2315 // Don't clone head of OSR loop to get correct types in start block.
2316 if (is_osr_flow() && head->start() == start_bci())
2317 continue;
2318
2319 // check _no_ shared head below us
2320 Loop* ch;
2321 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2322 if (ch != NULL)
2323 continue;
2324
2325 // Clone head
2326 Block* new_head = head->looping_succ(lp);
2327 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2328 // Update lp's info
2329 clone->set_loop(lp);
2330 lp->set_head(new_head);
2331 lp->set_tail(clone);
2332 // And move original head into outer loop
2333 head->set_loop(lp->parent());
2334
2335 rslt = true;
2336 }
2337 return rslt;
2338 }
2339
2340 // ------------------------------------------------------------------
2341 // ciTypeFlow::clone_loop_head
2342 //
2343 // Clone lp's head and replace tail's successors with clone.
2344 //
2345 // |
2346 // v
2347 // head <-> body
2348 // |
2349 // v
2350 // exit
2351 //
2352 // new_head
2353 //
2354 // |
2355 // v
2356 // head ----------\
2357 // | |
2358 // | v
2359 // | clone <-> body
2360 // | |
2361 // | /--/
2362 // | |
2363 // v v
2364 // exit
2365 //
2366 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2367 Block* head = lp->head();
2368 Block* tail = lp->tail();
2369 if (CITraceTypeFlow) {
2370 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2371 tty->print(" for predecessor "); tail->print_value_on(tty);
2372 tty->cr();
2373 }
2374 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2375 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2376
2377 assert(!clone->has_pre_order(), "just created");
2378 clone->set_next_pre_order();
2379
2380 // Insert clone after (orig) tail in reverse post order
2381 clone->set_rpo_next(tail->rpo_next());
2382 tail->set_rpo_next(clone);
2383
2384 // tail->head becomes tail->clone
2385 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2386 if (iter.succ() == head) {
2387 iter.set_succ(clone);
2388 // Update predecessor information
2389 head->predecessors()->remove(tail);
2390 clone->predecessors()->append(tail);
2391 }
2392 }
2393 flow_block(tail, temp_vector, temp_set);
2394 if (head == tail) {
2395 // For self-loops, clone->head becomes clone->clone
2396 flow_block(clone, temp_vector, temp_set);
2397 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2398 if (iter.succ() == head) {
2399 iter.set_succ(clone);
2400 // Update predecessor information
2401 head->predecessors()->remove(clone);
2402 clone->predecessors()->append(clone);
2403 break;
2404 }
2405 }
2406 }
2407 flow_block(clone, temp_vector, temp_set);
2408
2409 return clone;
2410 }
2411
2412 // ------------------------------------------------------------------
2413 // ciTypeFlow::flow_block
2414 //
2415 // Interpret the effects of the bytecodes on the incoming state
2416 // vector of a basic block. Push the changed state to succeeding
2417 // basic blocks.
2418 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2419 ciTypeFlow::StateVector* state,
2420 ciTypeFlow::JsrSet* jsrs) {
2421 if (CITraceTypeFlow) {
2422 tty->print("\n>> ANALYZING BLOCK : ");
2423 tty->cr();
2424 block->print_on(tty);
2425 }
2426 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2427
2428 int start = block->start();
2429 int limit = block->limit();
2430 int control = block->control();
2431 if (control != ciBlock::fall_through_bci) {
2432 limit = control;
2433 }
2434
2435 // Grab the state from the current block.
2436 block->copy_state_into(state);
2437 state->def_locals()->clear();
2438
2439 GrowableArray<Block*>* exceptions = block->exceptions();
2440 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2441 bool has_exceptions = exceptions->length() > 0;
2442
2443 bool exceptions_used = false;
2444
2445 ciBytecodeStream str(method());
2446 str.reset_to_bci(start);
2447 Bytecodes::Code code;
2448 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2449 str.cur_bci() < limit) {
2450 // Check for exceptional control flow from this point.
2451 if (has_exceptions && can_trap(str)) {
2452 flow_exceptions(exceptions, exc_klasses, state);
2453 exceptions_used = true;
2454 }
2455 // Apply the effects of the current bytecode to our state.
2456 bool res = state->apply_one_bytecode(&str);
2457
2458 // Watch for bailouts.
2459 if (failing()) return;
2460
2461 if (str.cur_bc() == Bytecodes::_monitorenter) {
2462 block->set_has_monitorenter();
2463 }
2464
2465 if (res) {
2466
2467 // We have encountered a trap. Record it in this block.
2468 block->set_trap(state->trap_bci(), state->trap_index());
2469
2470 if (CITraceTypeFlow) {
2471 tty->print_cr(">> Found trap");
2472 block->print_on(tty);
2473 }
2474
2475 // Save set of locals defined in this block
2476 block->def_locals()->add(state->def_locals());
2477
2478 // Record (no) successors.
2479 block->successors(&str, state, jsrs);
2480
2481 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2482
2483 // Discontinue interpretation of this Block.
2484 return;
2485 }
2486 }
2487
2488 GrowableArray<Block*>* successors = NULL;
2489 if (control != ciBlock::fall_through_bci) {
2490 // Check for exceptional control flow from this point.
2491 if (has_exceptions && can_trap(str)) {
2492 flow_exceptions(exceptions, exc_klasses, state);
2493 exceptions_used = true;
2494 }
2495
2496 // Fix the JsrSet to reflect effect of the bytecode.
2497 block->copy_jsrs_into(jsrs);
2498 jsrs->apply_control(this, &str, state);
2499
2500 // Find successor edges based on old state and new JsrSet.
2501 successors = block->successors(&str, state, jsrs);
2502
2503 // Apply the control changes to the state.
2504 state->apply_one_bytecode(&str);
2505 } else {
2506 // Fall through control
2507 successors = block->successors(&str, NULL, NULL);
2508 }
2509
2510 // Save set of locals defined in this block
2511 block->def_locals()->add(state->def_locals());
2512
2513 // Remove untaken exception paths
2514 if (!exceptions_used)
2515 exceptions->clear();
2516
2517 // Pass our state to successors.
2518 flow_successors(successors, state);
2519 }
2520
2521 // ------------------------------------------------------------------
2522 // ciTypeFlow::PostOrderLoops::next
2523 //
2524 // Advance to next loop tree using a postorder, left-to-right traversal.
2525 void ciTypeFlow::PostorderLoops::next() {
2526 assert(!done(), "must not be done.");
2527 if (_current->sibling() != NULL) {
2528 _current = _current->sibling();
2529 while (_current->child() != NULL) {
2530 _current = _current->child();
2531 }
2532 } else {
2533 _current = _current->parent();
2534 }
2535 }
2536
2537 // ------------------------------------------------------------------
2538 // ciTypeFlow::PreOrderLoops::next
2539 //
2540 // Advance to next loop tree using a preorder, left-to-right traversal.
2541 void ciTypeFlow::PreorderLoops::next() {
2542 assert(!done(), "must not be done.");
2543 if (_current->child() != NULL) {
2544 _current = _current->child();
2545 } else if (_current->sibling() != NULL) {
2546 _current = _current->sibling();
2547 } else {
2548 while (_current != _root && _current->sibling() == NULL) {
2549 _current = _current->parent();
2550 }
2551 if (_current == _root) {
2552 _current = NULL;
2553 assert(done(), "must be done.");
2554 } else {
2555 assert(_current->sibling() != NULL, "must be more to do");
2556 _current = _current->sibling();
2557 }
2558 }
2559 }
2560
2561 // ------------------------------------------------------------------
2562 // ciTypeFlow::Loop::sorted_merge
2563 //
2564 // Merge the branch lp into this branch, sorting on the loop head
2565 // pre_orders. Returns the leaf of the merged branch.
2566 // Child and sibling pointers will be setup later.
2567 // Sort is (looking from leaf towards the root)
2568 // descending on primary key: loop head's pre_order, and
2569 // ascending on secondary key: loop tail's pre_order.
2570 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2571 Loop* leaf = this;
2572 Loop* prev = NULL;
2573 Loop* current = leaf;
2574 while (lp != NULL) {
2575 int lp_pre_order = lp->head()->pre_order();
2576 // Find insertion point for "lp"
2577 while (current != NULL) {
2578 if (current == lp)
2579 return leaf; // Already in list
2580 if (current->head()->pre_order() < lp_pre_order)
2581 break;
2582 if (current->head()->pre_order() == lp_pre_order &&
2583 current->tail()->pre_order() > lp->tail()->pre_order()) {
2584 break;
2585 }
2586 prev = current;
2587 current = current->parent();
2588 }
2589 Loop* next_lp = lp->parent(); // Save future list of items to insert
2590 // Insert lp before current
2591 lp->set_parent(current);
2592 if (prev != NULL) {
2593 prev->set_parent(lp);
2594 } else {
2595 leaf = lp;
2596 }
2597 prev = lp; // Inserted item is new prev[ious]
2598 lp = next_lp; // Next item to insert
2599 }
2600 return leaf;
2601 }
2602
2603 // ------------------------------------------------------------------
2604 // ciTypeFlow::build_loop_tree
2605 //
2606 // Incrementally build loop tree.
2607 void ciTypeFlow::build_loop_tree(Block* blk) {
2608 assert(!blk->is_post_visited(), "precondition");
2609 Loop* innermost = NULL; // merge of loop tree branches over all successors
2610
2611 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2612 Loop* lp = NULL;
2613 Block* succ = iter.succ();
2614 if (!succ->is_post_visited()) {
2615 // Found backedge since predecessor post visited, but successor is not
2616 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2617
2618 // Create a LoopNode to mark this loop.
2619 lp = new (arena()) Loop(succ, blk);
2620 if (succ->loop() == NULL)
2621 succ->set_loop(lp);
2622 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2623
2624 } else { // Nested loop
2625 lp = succ->loop();
2626
2627 // If succ is loop head, find outer loop.
2628 while (lp != NULL && lp->head() == succ) {
2629 lp = lp->parent();
2630 }
2631 if (lp == NULL) {
2632 // Infinite loop, it's parent is the root
2633 lp = loop_tree_root();
2634 }
2635 }
2636
2637 // Check for irreducible loop.
2638 // Successor has already been visited. If the successor's loop head
2639 // has already been post-visited, then this is another entry into the loop.
2640 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2641 _has_irreducible_entry = true;
2642 lp->set_irreducible(succ);
2643 if (!succ->is_on_work_list()) {
2644 // Assume irreducible entries need more data flow
2645 add_to_work_list(succ);
2646 }
2647 Loop* plp = lp->parent();
2648 if (plp == NULL) {
2649 // This only happens for some irreducible cases. The parent
2650 // will be updated during a later pass.
2651 break;
2652 }
2653 lp = plp;
2654 }
2655
2656 // Merge loop tree branch for all successors.
2657 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2658
2659 } // end loop
2660
2661 if (innermost == NULL) {
2662 assert(blk->successors()->length() == 0, "CFG exit");
2663 blk->set_loop(loop_tree_root());
2664 } else if (innermost->head() == blk) {
2665 // If loop header, complete the tree pointers
2666 if (blk->loop() != innermost) {
2667 #ifdef ASSERT
2668 assert(blk->loop()->head() == innermost->head(), "same head");
2669 Loop* dl;
2670 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2671 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2672 #endif
2673 blk->set_loop(innermost);
2674 }
2675 innermost->def_locals()->add(blk->def_locals());
2676 Loop* l = innermost;
2677 Loop* p = l->parent();
2678 while (p && l->head() == blk) {
2679 l->set_sibling(p->child()); // Put self on parents 'next child'
2680 p->set_child(l); // Make self the first child of parent
2681 p->def_locals()->add(l->def_locals());
2682 l = p; // Walk up the parent chain
2683 p = l->parent();
2684 }
2685 } else {
2686 blk->set_loop(innermost);
2687 innermost->def_locals()->add(blk->def_locals());
2688 }
2689 }
2690
2691 // ------------------------------------------------------------------
2692 // ciTypeFlow::Loop::contains
2693 //
2694 // Returns true if lp is nested loop.
2695 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2696 assert(lp != NULL, "");
2697 if (this == lp || head() == lp->head()) return true;
2698 int depth1 = depth();
2699 int depth2 = lp->depth();
2700 if (depth1 > depth2)
2701 return false;
2702 while (depth1 < depth2) {
2703 depth2--;
2704 lp = lp->parent();
2705 }
2706 return this == lp;
2707 }
2708
2709 // ------------------------------------------------------------------
2710 // ciTypeFlow::Loop::depth
2711 //
2712 // Loop depth
2713 int ciTypeFlow::Loop::depth() const {
2714 int dp = 0;
2715 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2716 dp++;
2717 return dp;
2718 }
2719
2720 #ifndef PRODUCT
2721 // ------------------------------------------------------------------
2722 // ciTypeFlow::Loop::print
2723 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2724 for (int i = 0; i < indent; i++) st->print(" ");
2725 st->print("%d<-%d %s",
2726 is_root() ? 0 : this->head()->pre_order(),
2727 is_root() ? 0 : this->tail()->pre_order(),
2728 is_irreducible()?" irr":"");
2729 st->print(" defs: ");
2730 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2731 st->cr();
2732 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2733 ch->print(st, indent+2);
2734 }
2735 #endif
2736
2737 // ------------------------------------------------------------------
2738 // ciTypeFlow::df_flow_types
2739 //
2740 // Perform the depth first type flow analysis. Helper for flow_types.
2741 void ciTypeFlow::df_flow_types(Block* start,
2742 bool do_flow,
2743 StateVector* temp_vector,
2744 JsrSet* temp_set) {
2745 int dft_len = 100;
2746 GrowableArray<Block*> stk(dft_len);
2747
2748 ciBlock* dummy = _methodBlocks->make_dummy_block();
2749 JsrSet* root_set = new JsrSet(NULL, 0);
2750 Block* root_head = new (arena()) Block(this, dummy, root_set);
2751 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2752 root_head->set_pre_order(0);
2753 root_head->set_post_order(0);
2754 root_tail->set_pre_order(max_jint);
2755 root_tail->set_post_order(max_jint);
2756 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2757
2758 stk.push(start);
2759
2760 _next_pre_order = 0; // initialize pre_order counter
2761 _rpo_list = NULL;
2762 int next_po = 0; // initialize post_order counter
2763
2764 // Compute RPO and the control flow graph
2765 int size;
2766 while ((size = stk.length()) > 0) {
2767 Block* blk = stk.top(); // Leave node on stack
2768 if (!blk->is_visited()) {
2769 // forward arc in graph
2770 assert (!blk->has_pre_order(), "");
2771 blk->set_next_pre_order();
2772
2773 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2774 // Too many basic blocks. Bail out.
2775 // This can happen when try/finally constructs are nested to depth N,
2776 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2777 // "MaxNodeLimit / 2" is used because probably the parser will
2778 // generate at least twice that many nodes and bail out.
2779 record_failure("too many basic blocks");
2780 return;
2781 }
2782 if (do_flow) {
2783 flow_block(blk, temp_vector, temp_set);
2784 if (failing()) return; // Watch for bailouts.
2785 }
2786 } else if (!blk->is_post_visited()) {
2787 // cross or back arc
2788 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2789 Block* succ = iter.succ();
2790 if (!succ->is_visited()) {
2791 stk.push(succ);
2792 }
2793 }
2794 if (stk.length() == size) {
2795 // There were no additional children, post visit node now
2796 stk.pop(); // Remove node from stack
2797
2798 build_loop_tree(blk);
2799 blk->set_post_order(next_po++); // Assign post order
2800 prepend_to_rpo_list(blk);
2801 assert(blk->is_post_visited(), "");
2802
2803 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2804 // Assume loop heads need more data flow
2805 add_to_work_list(blk);
2806 }
2807 }
2808 } else {
2809 stk.pop(); // Remove post-visited node from stack
2810 }
2811 }
2812 }
2813
2814 // ------------------------------------------------------------------
2815 // ciTypeFlow::flow_types
2816 //
2817 // Perform the type flow analysis, creating and cloning Blocks as
2818 // necessary.
2819 void ciTypeFlow::flow_types() {
2820 ResourceMark rm;
2821 StateVector* temp_vector = new StateVector(this);
2822 JsrSet* temp_set = new JsrSet(NULL, 16);
2823
2824 // Create the method entry block.
2825 Block* start = block_at(start_bci(), temp_set);
2826
2827 // Load the initial state into it.
2828 const StateVector* start_state = get_start_state();
2829 if (failing()) return;
2830 start->meet(start_state);
2831
2832 // Depth first visit
2833 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2834
2835 if (failing()) return;
2836 assert(_rpo_list == start, "must be start");
2837
2838 // Any loops found?
2839 if (loop_tree_root()->child() != NULL &&
2840 env()->comp_level() >= CompLevel_full_optimization) {
2841 // Loop optimizations are not performed on Tier1 compiles.
2842
2843 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2844
2845 // If some loop heads were cloned, recompute postorder and loop tree
2846 if (changed) {
2847 loop_tree_root()->set_child(NULL);
2848 for (Block* blk = _rpo_list; blk != NULL;) {
2849 Block* next = blk->rpo_next();
2850 blk->df_init();
2851 blk = next;
2852 }
2853 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2854 }
2855 }
2856
2857 if (CITraceTypeFlow) {
2858 tty->print_cr("\nLoop tree");
2859 loop_tree_root()->print();
2860 }
2861
2862 // Continue flow analysis until fixed point reached
2863
2864 debug_only(int max_block = _next_pre_order;)
2865
2866 while (!work_list_empty()) {
2867 Block* blk = work_list_next();
2868 assert (blk->has_post_order(), "post order assigned above");
2869
2870 flow_block(blk, temp_vector, temp_set);
2871
2872 assert (max_block == _next_pre_order, "no new blocks");
2873 assert (!failing(), "no more bailouts");
2874 }
2875 }
2876
2877 // ------------------------------------------------------------------
2878 // ciTypeFlow::map_blocks
2879 //
2880 // Create the block map, which indexes blocks in reverse post-order.
2881 void ciTypeFlow::map_blocks() {
2882 assert(_block_map == NULL, "single initialization");
2883 int block_ct = _next_pre_order;
2884 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2885 assert(block_ct == block_count(), "");
2886
2887 Block* blk = _rpo_list;
2888 for (int m = 0; m < block_ct; m++) {
2889 int rpo = blk->rpo();
2890 assert(rpo == m, "should be sequential");
2891 _block_map[rpo] = blk;
2892 blk = blk->rpo_next();
2893 }
2894 assert(blk == NULL, "should be done");
2895
2896 for (int j = 0; j < block_ct; j++) {
2897 assert(_block_map[j] != NULL, "must not drop any blocks");
2898 Block* block = _block_map[j];
2899 // Remove dead blocks from successor lists:
2900 for (int e = 0; e <= 1; e++) {
2901 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2902 for (int k = 0; k < l->length(); k++) {
2903 Block* s = l->at(k);
2904 if (!s->has_post_order()) {
2905 if (CITraceTypeFlow) {
2906 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2907 s->print_value_on(tty);
2908 tty->cr();
2909 }
2910 l->remove(s);
2911 --k;
2912 }
2913 }
2914 }
2915 }
2916 }
2917
2918 // ------------------------------------------------------------------
2919 // ciTypeFlow::get_block_for
2920 //
2921 // Find a block with this ciBlock which has a compatible JsrSet.
2922 // If no such block exists, create it, unless the option is no_create.
2923 // If the option is create_backedge_copy, always create a fresh backedge copy.
2924 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2925 Arena* a = arena();
2926 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2927 if (blocks == NULL) {
2928 // Query only?
2929 if (option == no_create) return NULL;
2930
2931 // Allocate the growable array.
2932 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2933 _idx_to_blocklist[ciBlockIndex] = blocks;
2934 }
2935
2936 if (option != create_backedge_copy) {
2937 int len = blocks->length();
2938 for (int i = 0; i < len; i++) {
2939 Block* block = blocks->at(i);
2940 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2941 return block;
2942 }
2943 }
2944 }
2945
2946 // Query only?
2947 if (option == no_create) return NULL;
2948
2949 // We did not find a compatible block. Create one.
2950 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2951 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2952 blocks->append(new_block);
2953 return new_block;
2954 }
2955
2956 // ------------------------------------------------------------------
2957 // ciTypeFlow::backedge_copy_count
2958 //
2959 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2960 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2961
2962 if (blocks == NULL) {
2963 return 0;
2964 }
2965
2966 int count = 0;
2967 int len = blocks->length();
2968 for (int i = 0; i < len; i++) {
2969 Block* block = blocks->at(i);
2970 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2971 count++;
2972 }
2973 }
2974
2975 return count;
2976 }
2977
2978 // ------------------------------------------------------------------
2979 // ciTypeFlow::do_flow
2980 //
2981 // Perform type inference flow analysis.
2982 void ciTypeFlow::do_flow() {
2983 if (CITraceTypeFlow) {
2984 tty->print_cr("\nPerforming flow analysis on method");
2985 method()->print();
2986 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2987 tty->cr();
2988 method()->print_codes();
2989 }
2990 if (CITraceTypeFlow) {
2991 tty->print_cr("Initial CI Blocks");
2992 print_on(tty);
2993 }
2994 flow_types();
2995 // Watch for bailouts.
2996 if (failing()) {
2997 return;
2998 }
2999
3000 map_blocks();
3001
3002 if (CIPrintTypeFlow || CITraceTypeFlow) {
3003 rpo_print_on(tty);
3004 }
3005 }
3006
3007 // ------------------------------------------------------------------
3008 // ciTypeFlow::is_dominated_by
3009 //
3010 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3011 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3012 assert(!method()->has_jsrs(), "jsrs are not supported");
3013
3014 ResourceMark rm;
3015 JsrSet* jsrs = new ciTypeFlow::JsrSet(NULL);
3016 int index = _methodBlocks->block_containing(bci)->index();
3017 int dom_index = _methodBlocks->block_containing(dom_bci)->index();
3018 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3019 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3020
3021 // Start block dominates all other blocks
3022 if (start_block()->rpo() == dom_block->rpo()) {
3023 return true;
3024 }
3025
3026 // Dominated[i] is true if block i is dominated by dom_block
3027 int num_blocks = block_count();
3028 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3029 for (int i = 0; i < num_blocks; ++i) {
3030 dominated[i] = true;
3031 }
3032 dominated[start_block()->rpo()] = false;
3033
3034 // Iterative dominator algorithm
3035 bool changed = true;
3036 while (changed) {
3037 changed = false;
3038 // Use reverse postorder iteration
3039 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3040 if (blk->is_start()) {
3041 // Ignore start block
3042 continue;
3043 }
3044 // The block is dominated if it is the dominating block
3045 // itself or if all predecessors are dominated.
3046 int index = blk->rpo();
3047 bool dom = (index == dom_block->rpo());
3048 if (!dom) {
3049 // Check if all predecessors are dominated
3050 dom = true;
3051 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3052 Block* pred = blk->predecessors()->at(i);
3053 if (!dominated[pred->rpo()]) {
3054 dom = false;
3055 break;
3056 }
3057 }
3058 }
3059 // Update dominator information
3060 if (dominated[index] != dom) {
3061 changed = true;
3062 dominated[index] = dom;
3063 }
3064 }
3065 }
3066 // block dominated by dom_block?
3067 return dominated[block->rpo()];
3068 }
3069
3070 // ------------------------------------------------------------------
3071 // ciTypeFlow::record_failure()
3072 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3073 // This is required because there is not a 1-1 relation between the ciEnv and
3074 // the TypeFlow passes within a compilation task. For example, if the compiler
3075 // is considering inlining a method, it will request a TypeFlow. If that fails,
3076 // the compilation as a whole may continue without the inlining. Some TypeFlow
3077 // requests are not optional; if they fail the requestor is responsible for
3078 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3079 void ciTypeFlow::record_failure(const char* reason) {
3080 if (env()->log() != NULL) {
3081 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3082 }
3083 if (_failure_reason == NULL) {
3084 // Record the first failure reason.
3085 _failure_reason = reason;
3086 }
3087 }
3088
3089 ciType* ciTypeFlow::mark_as_never_null(ciType* type) {
3090 // Wrap the type to carry the information that it is never null
3091 return new (arena()) ciWrapper(type, /* never_null */ true);
3092 }
3093
3094 #ifndef PRODUCT
3095 // ------------------------------------------------------------------
3096 // ciTypeFlow::print_on
3097 void ciTypeFlow::print_on(outputStream* st) const {
3098 // Walk through CI blocks
3099 st->print_cr("********************************************************");
3100 st->print ("TypeFlow for ");
3101 method()->name()->print_symbol_on(st);
3102 int limit_bci = code_size();
3103 st->print_cr(" %d bytes", limit_bci);
3104 ciMethodBlocks *mblks = _methodBlocks;
3105 ciBlock* current = NULL;
3106 for (int bci = 0; bci < limit_bci; bci++) {
3107 ciBlock* blk = mblks->block_containing(bci);
3108 if (blk != NULL && blk != current) {
3109 current = blk;
3110 current->print_on(st);
3111
3112 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3113 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
3114
3115 if (num_blocks == 0) {
3116 st->print_cr(" No Blocks");
3117 } else {
3118 for (int i = 0; i < num_blocks; i++) {
3119 Block* block = blocks->at(i);
3120 block->print_on(st);
3121 }
3122 }
3123 st->print_cr("--------------------------------------------------------");
3124 st->cr();
3125 }
3126 }
3127 st->print_cr("********************************************************");
3128 st->cr();
3129 }
3130
3131 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3132 st->print_cr("********************************************************");
3133 st->print ("TypeFlow for ");
3134 method()->name()->print_symbol_on(st);
3135 int limit_bci = code_size();
3136 st->print_cr(" %d bytes", limit_bci);
3137 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3138 blk->print_on(st);
3139 st->print_cr("--------------------------------------------------------");
3140 st->cr();
3141 }
3142 st->print_cr("********************************************************");
3143 st->cr();
3144 }
3145 #endif